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All sourcesNASA NTRSDOE OSTI
DOE OSTI2015

The preliminary results: Seismic ambient noise Rayleigh wave tomography around Merapi volcano, central Java, Indonesia

Ambient noise tomography is relatively a new method for imaging the shallow structure of the Earth subsurface. We presents the application of this method to produce a Rayleigh wave group velocity maps around the Merapi Volcano, Central Java. Rayleigh waves group velocity maps were reconstructed from the cross-correlation of ambient noise recorded by the DOMERAPI array which consists 43 broadband seismometers. In the processing stage, we first filtered the observation data to separatethe noise from the signal that dominated by the strong volcanic activities. Next, we cross-correlate the filtered data and stack to obtain the Green’s function for all possible station pairs. Then we carefully picked the peak of each Green’s function to estimate the dispersion trend and appliedMultiple Filter Technique to obtain the dispersion curve. Inter-station group velocity curvesare inverted to produceRayleigh wave group velocity maps for periods 1 to 10 s. The resulted Rayleigh group velocity maps show the interesting features around the Merapi Volcano which generally agree with the previous studies. Merapi-Lawu Anomaly (MLA) is emerged as a relatively low anomaly in our group velocity maps.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2015

STAR results on central exclusive production in proton-proton collisions

We present a preliminary measurement of the Central Exclusive Production of the two oppositely charged pions produced in the process pp → ppπ{sup +} π{sup −}, obtained with the STAR detector at RHIC at √(s)=200 GeV. Silicon strip detectors placed in Roman Pots were used for tagging forward protons while pion pair tracks were reconstructed in the STAR Time Projection Chamber. Predictions of models based on Regge phenomenology are compared to the spectra of the kinematical variables corrected for detector acceptance and efficiency.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2015

A seven-degree-of-freedom, time-dependent quantum dynamics study on the energy efficiency in surmounting the central energy barrier of the OH + CH{sub 3} → O + CH{sub 4} reaction

A time-dependent, quantum reaction dynamics calculation with seven degrees of freedom was carried out to study the energy efficiency in surmounting the approximate center energy barrier of OH + CH{sub 3}. The calculation shows the OH vibration excitations greatly enhance the reactivity, whereas the vibrational excitations of CH{sub 3} and the rotational excitations hinder the reactivity. On the basis of equal amount of total energy, although this reaction has a slight early barrier, it is the OH vibrational energy that is the dominate force in promoting the reactivity, not the translational energy. The studies on both the forward O + CH{sub 4} and reverse OH + CH{sub 3} reactions demonstrate, for these central barrier reactions, a small change of the barrier location can significantly change the energy efficacy roles on the reactivity. The calculated rate constants agree with the experimental data.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2015

Water dynamics on ice and hydrate lattices studied by second-order central-line stimulated-echo oxygen-17 nuclear magnetic resonance

Oxygen-17 stimulated-echo spectroscopy is a novel nuclear magnetic resonance (NMR) technique that allows one to investigate the time scale and geometry of ultraslow molecular motions in materials containing oxygen. The method is based on detecting orientationally encoded frequency changes within oxygen’s central-transition NMR line that are caused by second-order quadrupolar interactions. In addition to the latter, the present theoretical analysis of various two-pulse echo and stimulated-echo pulse sequences takes also heteronuclear dipolar interactions into account. As an experimental example, the ultraslow water motion in polycrystals of tetrahydrofuran clathrate hydrate is studied via two-time oxygen-17 stimulated-echo correlation functions. The resulting correlation times and those of hexagonal ice are similar to those from previous deuteron NMR measurements. Calculations of the echo functions’ final-state correlations for various motional models are compared with the experimental data of the clathrate hydrate. It is found that a six-site model including the oxygen-proton dipolar interaction describes the present results.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2016

Profile of central research and application laboratory of Ağrı İbrahim Çeçen University

Ağrı İbrahim Çeçen University built a central research and application laboratory (CRAL) in the east of Turkey. The CRAL possesses 7 research and analysis laboratories, 12 experts and researchers, 8 standard rooms for guest researchers, a restaurant, a conference hall, a meeting room, a prey room and a computer laboratory. The CRAL aims certain collaborations between researchers, experts, clinicians and educators in the areas of biotechnology, bioimagining, food safety & quality, omic sciences such as genomics, proteomics and metallomics. It also intends to develop sustainable solutions in agriculture and animal husbandry, promote public health quality, collect scientific knowledge and keep it for future generations, contribute scientific awareness of all stratums of society, provide consulting for small initiatives and industries. It has been collaborated several scientific foundations since 2011.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

An unstaggered central scheme on nonuniform grids for the simulation of a compressible two-phase flow model

In this paper we extend a central finite volume method on nonuniform grids to the case of drift-flux two-phase flow problems. The numerical base scheme is an unstaggered, non oscillatory, second-order accurate finite volume scheme that evolves a piecewise linear numerical solution on a single grid and uses dual cells intermediately while updating the numerical solution to avoid the resolution of the Riemann problems arising at the cell interfaces. We then apply the numerical scheme and solve a classical drift-flux problem. The obtained results are in good agreement with corresponding ones appearing in the recent literature, thus confirming the potential of the proposed scheme.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2016

Simulation of the outdoor energy efficiency of an autonomous solar kit based on meteorological data for a site in Central Europe

This contribution analyzes the energy provided by a solar kit dedicated to autonomous usage and installed in Central Europe (Longitude 6.10°; Latitude 49.21° and Altitude 160 m) by using the simulation software PVSYST. We focused the analysis on the effect of temperature and solar irradiation on the I-V characteristic of a commercial PV panel. We also consider in this study the influence of charging and discharging the battery on the generator efficiency. Meteorological data are integrated into the simulation software. As expected, the solar kit provides an energy varying all along the year with a minimum in December. In the proposed approach, we consider this minimum as the lowest acceptable energy level to satisfy the use. Thus for the other months, a lost in the available renewable energy exists if no storage system is associated.

14 SOLAR ENERGY↗
DOE OSTI2021

Multi-energy reconstructions, central electron temperature measurements, and early detection of the birth and growth of runaway electrons using a versatile soft x-ray pinhole camera at MST

A multi-energy soft x-ray pinhole camera has been designed, built, and deployed at the Madison Symmetric Torus to aid the study of particle and thermal transport, as well as MHD stability physics. This novel imaging diagnostic technique employs a pixelated x-ray detector in which the lower energy threshold for photon detection can be adjusted independently on each pixel. The detector of choice is a PILATUS3 100 K with a 450 μm thick silicon sensor and nearly 100 000 pixels sensitive to photon energies between 1.6 and 30 keV. An ensemble of cubic spline smoothing functions has been applied to the line-integrated data for each time-frame and energy-range, obtaining a reduced standard-deviation when compared to that dominated by photon-noise. The multi-energy local emissivity profiles are obtained from a 1D matrix-based Abel-inversion procedure. Central values of Te can be obtained by modeling the slope of the continuum radiation from ratios of the inverted radial emissivity profiles over multiple energy ranges with no a priori assumptions of plasma profiles, magnetic field reconstruction constraints, high-density limitations, or need of shot-to-shot reproducibility. In tokamak plasmas, a novel application has recently been tested for early detection, 1D imaging, and study of the birth, exponential growth, and saturation of runaway electrons at energies comparable to 100 × Te,0; thus, early results are also presented.

Delgado-Aparicio, L. F. (ORCID:0000000167394380)↗
DOE OSTI2016

Proper central and core polynomials of relatively free associative algebras with identity of Lie nilpotency of degrees 5 and 6

We study the centre of a relatively free associative algebra F{sup (n)} with the identity [x{sub 1},…,x{sub n}]=0 of Lie nilpotency of degree n=5,6 over a field of characteristic 0. It is proved that the core Z{sup ∗}(F{sup (5)}) of the algebra F{sup (5)} (the sum of all ideals of F{sup (5)} contained in its centre) is generated as a T-ideal by the weak Hall polynomial [[x,y]{sup 2},y]. It is also proved that every proper central polynomial of F{sup (5)} is contained in the sum of Z{sup ∗}(F{sup (5)}) and the T-space generated by [[x,y]{sup 2},z] and the commutator [x{sub 1},…,x{sub 4}] of degree 4. This implies that the centre of F{sup (5)} is contained in the T-ideal generated by the commutator of degree 4. Similar results are obtained for F{sup (6)}; in particular, it is proved that the core Z{sup ∗}(F{sup (6)}) is generated as a T-ideal by the commutator of degree 5. Bibliography: 15 titles. (paper)

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2019

Protein interactions central to stabilizing the K[superscript +] channel selectivity filter in a four-sited configuration for selective K[superscript +] permeation

The structural and functional conversion of the nonselective NaK channel to a K{sup +} selective channel (NaK2K) allows us to identify two key residues, Tyr and Asp in the filter sequence of TVGYGD, that participate in interactions central to stabilizing the K{sup +} channel selectivity filter. By using protein crystallography and channel electrophysiology, we demonstrate that the K{sup +} channel filter exists as an energetically strained structure and requires these key protein interactions working in concert to hold the filter in the precisely defined four-sited configuration that is essential for selective K{sup +} permeation. Disruption of either interaction, as tested on both the NaK2K and eukaryotic K{sub v}1.6 channels, can reduce or completely abolish K{sup +} selectivity and in some cases may also lead to channel inactivation due to conformational changes at the filter. Additionally, on the scaffold of NaK we recapitulate the protein interactions found in the filter of the Kir channel family, which uses a distinct interaction network to achieve similar stabilization of the filter.

Sauer, David B.↗
DOE OSTI2011

Control of Proteobacterial Central Carbon Metabolism by the HexR Transcriptional Regulator. A Case Study in Shewanella oneidensis

Bacteria exploit multiple mechanisms for controlling central carbon metabolism (CCM). Thus, a bioinformatic analysis together with some experimental data implicated HexR transcriptional factor as a global CCM regulator in some lineages of Gammaproteobacteria operating as a functional replacement of Cra regulator characteristic of Enterobacteriales. In this study we combined a large-scale comparative genomic reconstruction of HexRcontrolled regulons in 87 species of Proteobacteria with the detailed experimental analysis of HexR regulatory network in Shewanella oneidensis model system. Although nearly all of the HexR-controlled genes are associated with CCM, remarkable variations were revealed in the scale (from 1-2 target operons in Enterobacteriales up to 20 operons in Aeromonadales) and gene content of HexR regulons between 11 compared lineages. A predicted 17-bp pseudo-palindrome with a consensus tTGTAATwwwATTACa, was confirmed as HexR-binding motif for 15 target operons (comprising 30 genes) by in vitro binding assays. The negative effect of the key CCM intermediate, 2-keto-3-deoxy-6- phosphogluconate, on the DNA-regulator complex formation was verified. A dual mode of HexR action on various target promoters, repression of genes involved in catabolic pathways and activation of gluconeogenic genes, was for the first time predicted by the bioinformatc analysis and experimentally verified by changed gene expression pattern in S. oneidensis AhexR mutant. Phenotypic profiling revealed the inability of this mutant to grow on lactate or pyruvate as a single carbon source. A comparative metabolic flux analysis of wild-type and mutant strains of S. oneidensis using 13Clactate labeling and GC-MS analysis confirmed the hypothesized HexR role as a master regulator of gluconeogenic flux from pyruvate via the transcriptional activation of phosphoenolpyruvate synthase (PpsA).

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2014

The B-type channel is a major route for iron entry into the ferroxidase center and central cavity of bacterioferritin

Bacterioferritin is a bacterial iron storage and detoxification protein that is capable of forming a ferric oxyhydroxide mineral core within its central cavity. To do this, iron must traverse the bacterioferritin protein shell, which is expected to occur through one or more of the channels through the shell identified by structural studies. The size and negative electrostatic potential of the 24 B-type channels suggest that they could provide a route for iron into bacterioferritin. Residues at the B-type channel (Asn-34, Glu-66, Asp-132, and Asp-139) of E. coli bacterioferritin were substituted to determine if they are important for iron core formation. A significant decrease in the rates of initial oxidation of Fe(II) at the ferroxidase center and subsequent iron mineralization was observed for the D132F variant. The crystal structure of this variant shows that substitution of residue 132 with phenylalanine caused a steric blockage of the B-type channel and no other material structural perturbation. Here, we conclude that the B-type channel is a major route for iron entry into both the ferroxidase center and the iron storage cavity of bacterioferritin.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2022

Ensuring planetary survival: the centrality of organic carbon in balancing the multifunctional nature of soils

Not only do soils provide 98.7% of the calories consumed by humans, they also provide numerous other functions upon which planetary survivability closely depends. However, our continuously increasing focus on soils for biomass provision (food, fiber, and energy) through intensive agriculture is rapidly degrading soils and diminishing their capacity to deliver other vital functions. These tradeoffs in soil functionality – the increased provision of one function at the expense of other critical planetary functions – are the focus of this review. Here, we examine how land-use change for biomass provision has decreased the ability of soils to regulate the carbon pool and thereby contribute profoundly to climate change, to cycle the nutrients that sustain plant growth and ecosystem health, to protect the soil biodiversity upon which many other functions depend, and to cycle the Earth’s freshwater supplies. We also examine how this decreasing ability of soil to provide these other functions can be halted and reversed. Despite the complexity and the interconnectedness of soil functions, we show that soil organic carbon plays a central role and is a master indicator for soil functioning and that we require a better understanding of the factors controlling the behavior and persistence of C in soils. Given the threats facing humanity and their economies, it is imperative that we recognize that Soil Security is itself an existential challenge and that we need to increase our focus on the multiple functions of soils for long-term human welfare and survivability of the planet.

Carboncarbon sequestration↗
DOE OSTI2019

Design and Analysis of the US ITER Central Solenoid Module Lifting Fixture

The central solenoid (CS) consists of six large high field superconducting magnets (also known as modules) approximately 4 m in diameter and 2 m tall that weigh approximately 120 tonnes each. These large and complex modules create challenges during assembly of the CS that require the development of custom assembly tooling such as the CS lifting fixture. The CS module lifting fixture is designed to lift and stack the six CS modules in the assembly building on the ITER site. Because of its unique design, fabrication, and assembly features, no lifting attachments could be incorporated within or under the CS modules. This limitation motivated the development of a friction-based lift fixture. The design and evaluation of the CS module lifting fixture considered both worker safety and investment protection, and the assessments were performed to international codes and standards. The CS module lifting fixture consists of two principal subassemblies: spider assembly and ring weldment. These subassemblies allow the frictional force to be augmented by the mechanical advantage of shallow-angle wedges. Large radial preloads created by both screw jack assemblies and the weight of a CS module develop frictional forces capable of performing a lift with a safety factor of at least 2. The design effort resulted in the use of low friction linear bearings on angle surfaces to ensure constant pressure, integrated jacks for pretensioning the fixture prior to lifting, and load pin strain gauges for monitoring the normal force. Testing of various materials and surface treatments led to the selection of laminated aluminum and rubber pads as the friction interface on the CS lifting fixture side and a grit-blasted Nitronic 50 stainless steel band on the CS module side. A redundant lifting method using the module slings between the spider and module is also utilized after the initial friction lift. The CS lifting fixture provides a safe and reliable solution for lifting and stacking the CS module during assembly.

Morris, Eric↗
DOE OSTI2011

THE CENTRAL SLOPE OF DARK MATTER CORES IN DWARF GALAXIES: SIMULATIONS VERSUS THINGS

We make a direct comparison of the derived dark matter (DM) distributions between hydrodynamical simulations of dwarf galaxies assuming a {Lambda}CDM cosmology and the observed dwarf galaxies sample from the THINGS survey in terms of (1) the rotation curve shape and (2) the logarithmic inner density slope {alpha} of mass density profiles. The simulations, which include the effect of baryonic feedback processes, such as gas cooling, star formation, cosmic UV background heating, and most importantly, physically motivated gas outflows driven by supernovae, form bulgeless galaxies with DM cores. We show that the stellar and baryonic mass is similar to that inferred from photometric and kinematic methods for galaxies of similar circular velocity. Analyzing the simulations in exactly the same way as the observational sample allows us to address directly the so-called cusp/core problem in the {Lambda}CDM model. We show that the rotation curves of the simulated dwarf galaxies rise less steeply than cold dark matter rotation curves and are consistent with those of the THINGS dwarf galaxies. The mean value of the logarithmic inner density slopes {alpha} of the simulated galaxies' DM density profiles is {approx}-0.4 {+-} 0.1, which shows good agreement with {alpha} = -0.29 {+-} 0.07 of the THINGS dwarf galaxies. The effect of non-circular motions is not significant enough to affect the results. This confirms that the baryonic feedback processes included in the simulations are efficiently able to make the initial cusps with {alpha} {approx}-1.0 to -1.5 predicted by DM-only simulations shallower and induce DM halos with a central mass distribution similar to that observed in nearby dwarf galaxies.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2011

THE DUST PROPERTIES OF TWO HOT R CORONAE BOREALIS STARS AND A WOLF-RAYET CENTRAL STAR OF A PLANETARY NEBULA: IN SEARCH OF A POSSIBLE LINK

We present new Spitzer/IRS spectra of two hot R Coronae Borealis (RCB) stars, one in the Galaxy, V348 Sgr, and one lying in the Large Magellanic Cloud, HV 2671. These two objects may constitute a link between the RCB stars and the late Wolf-Rayet ([WCL]) class of central stars of planetary nebulae (CSPNe), such as CPD -56{sup 0} 8032, that has little or no hydrogen in their atmospheres. HV 2671 and V348 Sgr are members of a rare subclass that has significantly higher effective temperatures than most RCB stars, but shares the traits of hydrogen deficiency and dust formation that define the cooler RCB stars. The [WC] CSPN star, CPD -56{sup 0} 8032, displays evidence of dual-dust chemistry showing both polycyclic aromatic hydrocarbons (PAHs) and crystalline silicates in its mid-IR spectrum. HV 2671 shows strong PAH emission but no sign of having crystalline silicates. The spectrum of V348 Sgr is very different from that of CPD -56{sup 0} 8032 and HV 2671. The PAH emission seen strongly in the other two stars is not present. Instead, the spectrum is dominated by a broad emission centered at about 8.2 {mu}m. This feature is not identified with either PAHs or silicates. Several other cool RCB stars, novae, and post-asymptotic giant branch stars show similar features in their IR spectra. The mid-IR spectrum of CPD -56{sup 0} 8032 shows emission features that may be associated with C{sub 60}. The other two stars do not show evidence of C{sub 60}. The different nature of the dust around these stars does not help us in establishing further links that may indicate a common origin. HV 2671 has also been detected by Herschel/PACS and SPIRE. V348 Sgr and CPD -56{sup 0} 8032 have been detected by AKARI/Far-Infrared Surveyor. These data were combined with Spitzer, IRAS, Two Micron All Sky Survey, and other photometry to produce their spectral energy distributions (SEDs) from the visible to the far-IR. Monte Carlo radiative transfer modeling was used to study the circumstellar dust around these stars. HV 2671 and CPD -56{sup 0} 8032 require both a flared inner disk with warm dust and an extended diffuse envelope with cold dust to fit their SEDs. The SED of V348 Sgr can be fit with a much smaller disk and envelope. The cold dust in the extended diffuse envelopes inferred around HV 2671 and CPD -56{sup 0} 8032 may consist of interstellar medium swept up during mass-loss episodes.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2012

CORRELATION ANALYSIS OF A LARGE SAMPLE OF NARROW-LINE SEYFERT 1 GALAXIES: LINKING CENTRAL ENGINE AND HOST PROPERTIES

We present a statistical study of a large, homogeneously analyzed sample of narrow-line Seyfert 1 (NLS1) galaxies, accompanied by a comparison sample of broad-line Seyfert 1 (BLS1) galaxies. Optical emission-line and continuum properties are subjected to correlation analyses, in order to identify the main drivers of the correlation space of active galactic nuclei (AGNs), and of NLS1 galaxies in particular. For the first time, we have established the density of the narrow-line region as a key parameter in Eigenvector 1 space, as important as the Eddington ratio L/L{sub Edd}. This is important because it links the properties of the central engine with the properties of the host galaxy, i.e., the interstellar medium (ISM). We also confirm previously found correlations involving the line width of H{beta} and the strength of the Fe II and [O III] {lambda}5007 emission lines, and we confirm the important role played by L/L{sub Edd} in driving the properties of NLS1 galaxies. A spatial correlation analysis shows that large-scale environments of the BLS1 and NLS1 galaxies of our sample are similar. If mergers are rare in our sample, accretion-driven winds, on the one hand, or bar-driven inflows, on the other hand, may account for the strong dependence of Eigenvector 1 on ISM density.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2011

SUBMILLIMETER ARRAY/PLATEAU DE BURE INTERFEROMETER MULTIPLE LINE OBSERVATIONS OF THE NEARBY SEYFERT 2 GALAXY NGC 1068: SHOCK-RELATED GAS KINEMATICS AND HEATING IN THE CENTRAL 100 pc?

We present high angular resolution (0.''5-2.''0) observations of the millimeter continuum and the {sup 12}CO(J = 3-2), {sup 13}CO(J = 3-2), {sup 13}CO(J = 2-1), C{sup 18}O(J = 2-1), HCN(J = 3-2), HCO{sup +}(J = 4-3), and HCO{sup +}(J = 3-2) line emission in the circumnuclear disk (r {approx}< 100 pc) of the prototypical Seyfert 2 galaxy NGC 1068, carried out with the Submillimeter Array. We also include in our analysis new {sup 13}CO(J = 1-0) and improved {sup 12}CO(J = 2-1) observations of NGC 1068 at high angular resolution (1.''0-2.''0) and sensitivity, conducted with the Institute de Radioastronomie Millimetrique Plateau de Bure Interferometer. Based on the complex dynamics of the molecular gas emission indicating non-circular motions in the central {approx}100 pc, we propose a scenario in which part of the molecular gas in the circumnuclear disk of NGC 1068 is blown radially outward as a result of shocks. This shock scenario is further supported by quite warm (T{sub kin} {>=} 200 K) and dense (n(H{sub 2}) {approx_equal} 10{sup 4} cm{sup -3}) gas constrained from observed molecular line ratios. The HCN abundance in the circumnuclear disk is found to be [HCN]/[{sup 12}CO] {approx} 10{sup -3.5}. This is slightly higher than the abundances derived for Galactic and extragalactic star-forming/starbursting regions. This result lends further support to X-ray-enhanced HCN formation in the circumnuclear disk of NGC 1068 as suggested by earlier studies. The HCO{sup +} abundance ([HCO{sup +}]/[{sup 12}CO] {approx} 10{sup -5}) appears to be somewhat lower than that of Galactic and extragalactic star-forming/starbursting regions. When trying to fit the centimeter-to-millimeter continuum emission by different thermal and non-thermal processes, it appears that electron-scattered synchrotron emission yields the best results while thermal free-free emission seems to overpredict the millimeter continuum emission.

79 ASTRONOMY AND ASTROPHYSICS↗