These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

High poloidal beta long-pulse experiments in the Tokamak Fusion Test Reactor*  

E-print Network

High poloidal beta long-pulse experiments in the Tokamak Fusion Test Reactor* J. Kesner+ Plasma 1992; accepted 17 March 1993) Experiments have been performed in the Tokamak Fusion Test Reactor [D. M Agency, Vienna, 1991>, Vol. 1, p. 91 with neutral beam injection of up to 4 sec. duration, which

Mauel, Michael E.

2

Fusion alpha-particle losses in a high-beta rippled tokamak  

NASA Astrophysics Data System (ADS)

In tokamak plasmas, the confinement of energetic ions depends on the magnetic field structure. If the plasma pressure is finite, the equilibrium current (i.e., the Pfirsch-Schlter current and diamagnetic current) flows in the plasma to maintain the magnetohydrodynamic (MHD) equilibrium. These plasma currents generate poloidal and toroidal magnetic field and alter the field structure. Moreover, if we consider the non-axisymmetry of magnetic field structures such as toroidal field (TF) ripples, the non-axisymmetric component of the equilibrium current can alter TF ripples themselves. When the plasma beta becomes high, the changes in the field structure due to the equilibrium current might affect the confinement of energetic ions significantly. We intend to clarify how these currents alter the field structure and affect the confinement of alpha particles in high-beta plasma. The MHD equilibrium is calculated using VMEC and the orbits of fusion alpha particles are followed by using the fully three-dimensional magnetic field orbit-following Monte Carlo code. In relatively low-beta plasma (e.g., the volume-averaged beta value ????2%), the changes in the magnetic field component due to the plasma current negligibly affect the confinement of alpha particles except for the Shafranov shift effect. However, for ????3%, the diamagnetic effect reduces the magnetic field strength and significantly increases alpha-particle losses. In these high-beta cases, the non-axisymmetric field component generated by the equilibrium current also increases these losses, but not as effectively as compared to the diamagnetic effect.

Bunno, M.; Nakamura, Y.; Suzuki, Y.; Shinohara, K.; Matsunaga, G.; Tani, K.

2013-08-01

3

High-beta steady-state research and future directions on the Japan Atomic Energy Research Institute Tokamak60 Upgrade and the Japan Atomic Energy Research Institute Fusion Torus2 Modified  

Microsoft Academic Search

In the Japan Atomic Energy Research Institute Tokamak-60 Upgrade (JT-60U), a high-betap ELMy H-mode (high-poloidal-beta high-confinement-mode with edge localized mode) plasma was sustained with betaN~2.7 for 7.4 s. Real-time neoclassical tearing mode (NTM) stabilization system was established and effective NTM suppression by early electron cyclotron (EC) wave injection was demonstrated. High fusion triple product of ni(0)tauETi(0)=3.11020 keV.s.m-3 was achieved using

S. Ishida

2004-01-01

4

Nanoscale organization of {beta}{sub 2}-adrenergic receptor-Venus fusion protein domains on the surface of mammalian cells  

SciTech Connect

Adrenergic receptors are a key component of nanoscale multiprotein complexes that are responsible for controlling the beat rate in a mammalian heart. We demonstrate the ability of near-field scanning optical microscopy (NSOM) to visualize {beta}{sub 2}-adrenergic receptors ({beta}{sub 2}AR) fused to the GFP analogue Venus at the nanoscale on HEK293 cells. The expression of the {beta}{sub 2}AR-Venus fusion protein was tightly controlled using a tetracycline-induced promoter. Both the size and density of the observed nanoscale domains are dependent on the level of induction and thus the level of protein expression. At concentrations between 100 and 700 ng/ml of inducer doxycycline, the size of domains containing the {beta}{sub 2}AR-Venus fusion protein appears to remain roughly constant, but the number of domains per cell increase. At 700 ng/ml doxycycline the functional receptors are organized into domains with an average diameter of 150 nm with a density similar to that observed for the native protein on primary murine cells. By contrast, larger micron-sized domains of {beta}{sub 2}AR are observed in the membrane of the HEK293 cells that stably overexpress {beta}{sub 2}AR-GFP and {beta}{sub 2}AR-eYFP. We conclude that precise chemical control of gene expression is highly advantageous for the use {beta}{sub 2}AR-Venus fusion proteins as models for {beta}{sub 2}AR function. These observations are critical for designing future cell models and assays based on {beta}{sub 2}AR, since the receptor biology is consistent with a relatively low density of nanoscale receptor domains.

Vobornik, Dusan; Rouleau, Yanouchka; Haley, Jennifer [Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, ON, Canada K1A 0R6 (Canada)] [Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, ON, Canada K1A 0R6 (Canada); Bani-Yaghoub, Mahmud [Institute for Biological Sciences, National Research Council Canada, Ottawa, ON, Canada K1A 0R6 (Canada)] [Institute for Biological Sciences, National Research Council Canada, Ottawa, ON, Canada K1A 0R6 (Canada); Taylor, Rod [Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, ON, Canada K1A 0R6 (Canada)] [Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, ON, Canada K1A 0R6 (Canada); Johnston, Linda J., E-mail: Linda.Johnston@nrc-cnrc.gc.ca [Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, ON, Canada K1A 0R6 (Canada); Pezacki, John Paul, E-mail: John.Pezacki@nrc-cnrc.gc.ca [Steacie Institute for Molecular Sciences, National Research Council Canada, Ottawa, ON, Canada K1A 0R6 (Canada)

2009-04-24

5

Expression of a connexin 43/beta-galactosidase fusion protein inhibits gap junctional communication in NIH3T3 cells  

PubMed Central

Gap junctions contain membrane channels that mediate the cell-to-cell movement of ions, metabolites and cell signaling molecules. As gap junctions are comprised of a hexameric array of connexin polypeptides, the expression of a mutant connexin polypeptide may exert a dominant negative effect on gap junctional communication. To examine this possibility, we constructed a connexin 43 (Cx43)/beta-galactosidase (beta-gal) expression vector in which the bacterial beta-gal protein is fused in frame to the carboxy terminus of Cx43. This vector was transfected into NIH3T3 cells, a cell line which is well coupled via gap junctions and expresses high levels of Cx43. Transfectant clones were shown to express the fusion protein by northern and western analysis. X-Gal staining further revealed that all of the fusion protein containing cells also expressed beta-gal enzymatic activity. Double immunostaining with a beta-gal and Cx43 antibody demonstrated that the fusion protein is immunolocalized to the perinuclear region of the cytoplasm and also as punctate spots at regions of cell-cell contact. This pattern is similar to that of Cx43 in the parental 3T3 cells, except that in the fusion protein expressing cells, Cx43 expression was reduced at regions of cell-cell contact. Examination of gap junctional communication (GJC) with dye injection studies further showed that dye coupling was inhibited in the fusion protein expressing cells, with the largest reduction in coupling found in a clone exhibiting little Cx43 localization at regions of cell-cell contact. When the fusion protein expression vector was transfected into the communication poor C6 cell line, abundant fusion protein expression was observed, but unlike the transfected NIH3T3 cells, no fusion protein was detected at the cell surface. Nevertheless, dye coupling was inhibited in these C6 cells. Based on these observations, we propose that the fusion protein may inhibit GJC by sequestering the Cx43 protein intracellularly. Overall, these results demonstrate that the Cx43/beta-gal fusion protein can exert a dominant negative effect on GJC in two different cell types, and suggests that it may serve as a useful approach for probing the biological function of gap junctions. PMID:7542247

1995-01-01

6

High Level Information Fusion (HLIF) with nested fusion loops  

NASA Astrophysics Data System (ADS)

Situation modeling and threat prediction require higher levels of data fusion in order to provide actionable information. Beyond the sensor data and sources the analyst has access to, the use of out-sourced and re-sourced data is becoming common. Through the years, some common frameworks have emerged for dealing with information fusionperhaps the most ubiquitous being the JDL Data Fusion Group and their initial 4-level data fusion model. Since these initial developments, numerous models of information fusion have emerged, hoping to better capture the human-centric process of data analyses within a machine-centric framework. 21st Century Systems, Inc. has developed Fusion with Uncertainty Reasoning using Nested Assessment Characterizer Elements (FURNACE) to address challenges of high level information fusion and handle bias, ambiguity, and uncertainty (BAU) for Situation Modeling, Threat Modeling, and Threat Prediction. It combines JDL fusion levels with nested fusion loops and state-of-the-art data reasoning. Initial research has shown that FURNACE is able to reduce BAU and improve the fusion process by allowing high level information fusion (HLIF) to affect lower levels without the double counting of information or other biasing issues. The initial FURNACE project was focused on the underlying algorithms to produce a fusion system able to handle BAU and repurposed data in a cohesive manner. FURNACE supports analyst's efforts to develop situation models, threat models, and threat predictions to increase situational awareness of the battlespace. FURNACE will not only revolutionize the military intelligence realm, but also benefit the larger homeland defense, law enforcement, and business intelligence markets.

Woodley, Robert; Gosnell, Michael; Fischer, Amber

2013-05-01

7

Affibody-beta-galactosidase immunoconjugates produced as soluble fusion proteins in the Escherichia coli cytosol.  

PubMed

Recombinant immunoconjugates constitute a novel class of immunoassay reagents produced by genetic fusion between an antigen recognizing moiety and a reporter enzyme or fluorescent protein, obviating the need for chemical coupling. In this work, we describe the construction, Escherichia coli production and characterization of recombinant beta-galactosidase (beta-gal)-based immunoconjugates directed to human immunoglobulin A (IgA). As the antigen recognizing moieties, either monovalent or dimeric (head-to-tail) versions of an IgA-specific affibody (Z(IgA1)) were used, previously selected in vitro from a protein library based on combinatorial engineering of a single staphylococcal protein A domain. To increase the likelihood of proper presentation on the assembled homotetrameric enzyme surface, the affibody moieties were linked to the N-terminus of the enzyme subunits via a heptapeptide linker sequence. The two resulting immunoconjugates Z(IgA1)-beta-gal and (Z(IgA1))(2)-beta-gal, containing four and eight affibody moieties per enzyme, respectively, could be expressed as soluble and proteolytically stable proteins intracellularly in E. coli from where they were purified to high purity by a single anion exchange chromatography step. The yields of immunoconjugates were in the range 200-400 mg/l culture. Biosensor-binding studies showed that both the Z(IgA1)-beta-gal and (Z(IgA1))(2)-beta-gal immunoconjugates were capable of selective IgA-recognition, but with an apparent higher binding affinity for the variant containing divalent affibody moieties, presumably due to avidity effects. The applicability of this class of recombinant immunoconjugates was demonstrated by IgA detection in enzyme-linked immunosorbent assay (ELISA) and dot-blot analyses. In addition, using human kidney biopsy samples from a nephropathy patient, IgA depositions in glomeruli could be detected by immunohistochemistry with low background staining of tissue. PMID:14580889

Rnnmark, Jenny; Kampf, Caroline; Asplund, Anna; Hidn-Guthenberg, Ingmarie; Wester, Kenneth; Pontn, Fredrik; Uhln, Mathias; Nygren, Per-Ake

2003-10-01

8

Laser Fusion Energy The High Average Power  

E-print Network

Laser Fusion Energy and The High Average Power Program John Sethian Naval Research Laboratory Dec for Inertial Fusion Energy with lasers, direct drive targets and solid wall chambers Lasers DPPSL (LLNL) Kr posters Snead Payne #12;Laser(s) Goals 1. Develop technologies that can meet the fusion energy

9

Fusion reactors-high temperature electrolysis (HTE)  

Microsoft Academic Search

Results of a study to identify and develop a reference design for synfuel production based on fusion reactors are given. The most promising option for hydrogen production was high-temperature electrolysis (HTE). The main findings of this study are: 1. HTE has the highest potential efficiency for production of synfuels from fusion; a fusion to hydrogen energy efficiency of about 70%

Fillo

1978-01-01

10

Fusion zone microstructure and porosity in electron beam welds of an {alpha} + {beta} titanium alloy  

SciTech Connect

The effect of electron beam welding parameters on fusion zone (FZ) microstructure and porosity in a Ti-6.8 Al-3.42 Mo-1.9 Zr-0.21 Si alloy (Russian designation VT 9) has been investigated. It has been observed that the FZ grain width increased continuously with increase in heat input when the base metal was in the {beta} heat-treated condition, while in the {alpha} + {beta} heat-treated base metal welds, the FZ grain width increased only after a threshold energy input. The difference is attributed to both the weld thermal cycle and the pinning effect of equiaxed primary alpha on grain growth in the heat-affected zone (HAZ) of {alpha} + {beta} heat-treated base metal. Postweld heat treatment (PWHT) in the subtransus and supertransus regions did not alter the columnar grain morphology in the FZ, possibly due to the lack of enough driving force for the formation of new grains by the breaking up of the columnar grains and grain boundary movement for grain growth. The highest porosity was observed at intermediate welding speeds. At low speeds, a majority of pores formed at the fusion boundary, while at high speeds, occurrence of porosity was maximum at the weld center. The trends on porosity can be explained on the basis of solubility of hydrogen in titanium as a function of temperature and the influence of weld thermal cycle on nucleation, growth, and escape of hydrogen gas bubbles. The porosity at slow welding speeds is low because sufficient time exists for the nucleation, growth, and escape of hydrogen gas bubbles, while insufficient time exists for the nucleation of gas bubbles at high welding speeds. The effect of pickling of joint surface, vacuum annealing of the base metal, and successive remelting of the weld metal has also been investigated.

Mohandas, T.; Banerjee, D. [Defence Metallurgical Research Lab., Hyderabad (India); Kutumba Rao, V.V. [Banaras Hindu Univ., Varanasi (India)

1999-03-01

11

Protein fusions of beta-galactosidase to the ferrichrome-iron receptor of Escherichia coli K-12.  

PubMed Central

The fusion-generating phage lambda plac Mu1 was used to produce fusions of lacZ to fhuA, the gene encoding the ferrichrome-iron receptor (FhuA protein) in the outer membrane of Escherichia coli K-12. Fusions to the fhuA gene in a delta (lac) strain were selected by their resistance to bacteriophage phi 80 vir. Ten independent (fhuA'-'lacZ) fusions were all Lac+ and were resistant to the lethal agents which require the FhuA protein as receptor, i.e., phi 80 vir, T5, T1, UC-1, and colicin M; none could utilize ferrichrome as the sole iron source. Specialized transducing phages were obtained by illegitimate excision from the chromosome of each of the fusion-bearing strains, and EcoRI fragments which encoded the fusions were subcloned into the high-copy plasmid pMLB524. Physical mapping of the fusion-containing plasmids confirmed the presence of three restriction sites which were also located on the chromosomal DNA of sequences near the fhuA gene. The direction of transcription of the fhuA gene was deduced from the direction of transcription of the (fhuA'-'lacZ) gene fusion. Identification of the chimeric proteins was made by both radiolabeling cells and immunoprecipitating the LacZ-containing proteins with antibody to beta-galactosidase and by preparing whole cell extracts from Lac+ cells containing the cloned gene fusions. Two sizes of (FhuA'-'LacZ) proteins were detected, 121 kDa and 124 kDa. The DNA sequences at the unique fusion joints were determined. The sequence information allowed us to identify three distinct fusion joints which were grouped as follows, type I fusions, 5'-ACT GCT CAG CCA A-3'; type IIa fusions, 5'-GCG GTT GAA CCG A-3'; and type IIb fusions: 5'-ACC GCT GCA CCT G-3'. To orient these fhuA fusion joints, the complete nucleotide sequence of the fhuA gene was determined from a 2,902-base-pair fragment of DNA. A single open reading frame was found which translated into a 747-amino acid polypeptide. The signal sequence of 33 amino acids was followed by a mature protein with a molecular weight of 78,992. Alignment of the amino acid sequence of the FhuA protein with the amino acid sequences presented for two other tonB-dependent receptor proteins in the outer membrane of E. coli showed an area of local homology at the amino terminus of all three proteins. Images PMID:3079747

Coulton, J W; Mason, P; Cameron, D R; Carmel, G; Jean, R; Rode, H N

1986-01-01

12

Very high efficiency fusion reactor concept  

Microsoft Academic Search

Very high fusion reactor net efficiencies (>65%) are shown to be feasible through a new mode of advanced fuel tandem mirror operation. Inducing nonadiabaticity for fusion products not needed to sustain the plasma against losses enhances their end loss rate, leading to a narrow end loss energy spectrum and resultant very high efficiency direct electrostatic conversion. Magnetic field gradients required

J. F. Santarius

1987-01-01

13

High-density-plasma diagnostics in magnetic-confinement fusion  

SciTech Connect

The lectures will begin by defining high density in the context of magnetic confinement fusion research and listing some alternative reactor concepts, ranging from n/sub e/ approx. 2 x 10/sup 14/ cm/sup -3/ to several orders of magnitude greater, that offer potential advantages over the main-line, n/sub e/ approx. 1 x 10/sup 14/ cm/sup -3/, Tokamak reactor designs. The high density scalings of several major diagnostic techniques, some favorable and some disadvantageous, will be discussed. Special emphasis will be given to interferometric methods, both electronic and photographic, for which integral n/sub e/dl measurements and associated techniques are accessible with low wavelength lasers. Reactor relevant experience from higher density, smaller dimension devices exists. High density implies high ..beta.., which implies economies of scale. The specialized features of high ..beta.. diagnostics will be discussed.

Jahoda, F.C.

1982-01-01

14

Expression of a mouse metallothionein-Escherichia coli. beta. -galactosidase fusion gene (MT-. beta. gal) in early mouse embryos  

SciTech Connect

The authors have microinjected DNA containing the inducible mouse metallothionein-I (MT-I) promoter, coupled to the structural gene for Escherichia coli {beta}-galactosidase (lacZ), into the pronuclei of one-cell mouse embryos. A qualitative histochemical assay, with 5-bromo-4-chloro-3-indolyl {beta}-D-galactopyranoside (X-Gal) as a substrate, was used to detect expression of lacZ at several preimplantation stages. They observed staining indicative of exogenous {beta}-galactosidase activity in 5-17% of DNA-injected embryos assayed at preimplantation stages after 16-24 h treatment with ZnSO{sub 4}. Thus, lacZ can be used as an indicator gene for promoter function during early mouse embryogenesis, and the incorporation of the MT-I promoter into fusion genes can be a useful means of controlling the expression of exogenous genes in preimplantation mouse embryos.

Stevens, M.E.; Meneses, J.J.; Pedersen, R.A. (Univ. of California, San Francisco (United States))

1989-08-01

15

Modular low aspect ratio-high beta torsatron  

DOEpatents

A fusion reactor device in which the toroidal magnetic field and at least a portion of the poloidal magnetic field are provided by a single set of modular coils. The coils are arranged on the surface of a low aspect ratio toroid in planes having the cylindrical coordinate relationship .phi.=.phi..sub.i +kz where k is a constant equal to each coil's pitch and .phi..sub.i is the toroidal angle at which the i'th coil intersects the z=o plane. The device may be described as a modular, high beta torsation whose screw symmetry is pointed along the systems major (z) axis. The toroid defined by the modular coils preferably has a racetrack minor cross section. When vertical field coils and preferably a toroidal plasma current are provided for magnetic field surface closure within the toroid, a vacuum magnetic field of racetrack shaped minor cross section with improved stability and beta valves is obtained.

Sheffield, George V. (Hopewell, NJ); Furth, Harold P. (Princeton, NJ)

1984-02-07

16

High beta and confinement studies of TFTR  

SciTech Connect

The project discussed in this report are: Enhanced High Poloidal Beta Operation in TFTR with Deuterium Pellet Injection; Approaching High Q by Utilizing High [beta][sub p] Operation in TFTR; Advanced Tokamak Regime Experiment, and Second Regime Studies at large Major Radius High [beta][sub p] Plasmas. Analysis of the data taken during these experiments as well as continuing analysis of earlier data led to a number important results described in publications in the past year including two invited presentations at the 1992 American Physical Society Division of Plasma Physics Meeting in Seattle an oral presentation at the 1992 IAEA Meeting in Wuertzburg, Germany, and a Physical Review Letter. These results included extending the high 11/2 regime to 1.2 MA current and neutron production rates to more than 3 [times] 10[sup 16] sec[sup [minus

Navratil, G.A.; Bhattacharjee, A.; Iacono, R.; Mauel, M.E.; Sabbagh, S.A. (Columbia Univ., New York, NY (United States)); Kesner, J. (Massachusetts Inst. of Tech., Cambridge, MA (United States))

1993-01-01

17

Origin and ascendancy of a chimeric fusion gene: the beta/delta-globin gene of paenungulate mammals.  

PubMed

The delta-globin gene (HBD) of eutherian mammals exhibits a propensity for recombinational exchange with the closely linked beta-globin gene (HBB) and has been independently converted by the HBB gene in multiple lineages. Here we report the presence of a chimeric beta/delta fusion gene in the African elephant (Loxodonta africana) that was created by unequal crossing-over between misaligned HBD and HBB paralogs. The recombinant chromosome that harbors the beta/delta fusion gene in elephants is structurally similar to the "anti-Lepore" duplication mutant of humans (the reciprocal exchange product of the hemoglobin Lepore deletion mutant). However, the situation in the African elephant is unique in that the chimeric beta/delta fusion gene supplanted the parental HBB gene and is therefore solely responsible for synthesizing the beta-chain subunits of adult hemoglobin. A phylogenetic survey of beta-like globin genes in afrotherian and xenarthran mammals revealed that the origin of the chimeric beta/delta fusion gene and the concomitant inactivation of the HBB gene predated the radiation of "Paenungulata," a clade of afrotherian mammals that includes three orders: Proboscidea (elephants), Sirenia (dugongs and manatees), and Hyracoidea (hyraxes). The reduced fitness of the human Hb Lepore deletion mutant helps to explain why independently derived beta/delta fusion genes (which occur on an anti-Lepore chromosome) have been fixed in a number of mammalian lineages, whereas the reciprocal delta/beta fusion gene (which occurs on a Lepore chromosome) has yet to be documented in any nonhuman mammal. This illustrates how the evolutionary fates of chimeric fusion genes can be strongly influenced by their recombinational mode of origin. PMID:19332641

Opazo, Juan C; Sloan, Angela M; Campbell, Kevin L; Storz, Jay F

2009-07-01

18

Steady-state sustainment of high-beta plasmas through stability control in Japan Atomic Energy Research Institute Tokamak60 Upgrade  

Microsoft Academic Search

Recent results from steady-state sustainment of high-beta plasma experiments in the Japan Atomic Energy Research Institute Tokamak-60 Upgrade (JT-60U) tokamak [A. Kitsunezaki et al., Fusion Sci. Technol. 42, 179 (2002)] are described. Extension of discharge duration to 65 s (formerly 15 s) has enabled physics research with long time scale. In long-duration high-beta research, the normalized beta betaN=2.5, which is

A. Isayama

2005-01-01

19

Preliminary evaluation of beta-spodumene as a fusion reactor structural material  

SciTech Connect

Beta-spodumene was investigated as a candidate material for use in fusion reactor environments. Properties which support the use of beta-spodumene include good thermal shock resistance, a very low coefficient of thermal expansion, a low-Z composition which would result in minimum impact on the plasma, and flexibility in fabrication processes. Specimens were irradiated in the Advanced Test Reactor (ATR) to a fluence of 5.3 x 10/sup 22/ n/m/sup 2/, E > 0.1 MeV, and 4.9 x 10/sup 23/ n/m/sup 2/ thermal fluence in order to obtain a preliminary evaluation of the impact of irradiation on the material. Preliminary data indicate that the mechanical properties of beta-spodumene are little affected by irradiation. Gas production and release have also been investigated.

Kelsey, P.V. Jr.; Schmunk, R.E.; Henslee, S.P.

1981-01-01

20

High Temperature Stability of Potassium Beta Alumina  

NASA Technical Reports Server (NTRS)

None. From Objectives section: Evaluate the stability of potassium beta alumina under potassium AMTEC operating conditions. Evaluate the stability regime in which potassium beta alumina can be fabricated.

Williams, R. M.; Kisor, A.; Ryan, M. A.

1996-01-01

21

Tokamak MHD Stability at High Beta and Low Plasma Rotation  

NASA Astrophysics Data System (ADS)

Recent high-beta DIII-D experiments with the new capability of balanced neutral beam injection show that the resistive wall mode (RWM) remains stable even with significant reductions in the neutral beam torque relative to pure co-injection. Previous DIII-D experiments showed a higher plasma rotation threshold (1-3%,A) for RWM stabilization when resonant magnetic braking was used to lower the plasma rotation. We speculate that the previously observed rotation threshold corresponds to the entrance into a forbidden band of rotation that results from torque balance including the resonant field amplification by the stable RWM. Previous and recent experimental data show a bifurcation taking place when the plasma rotation is reduced to half its unperturbed value, consistent with theory [1]. This hypothesis may have implications for both RWM stability and error field tolerances in ITER. 4pt[1] R. Fitzpatrick, Nucl. Fusion 33, 1049 (1993).

Garofalo, A. M.; Reimerdes, H.; Lanctot, M. J.; Albrecht, J. T.; Okabayashi, M.; Solomon, W. M.; Jackson, G. L.; La Haye, R. J.; Strait, E. J.

2006-10-01

22

The Heavy Ion Fusion Science Virtual National Laboratory Overview of Heavy Ion Fusion / High Energy  

E-print Network

11/29/2007 The Heavy Ion Fusion Science Virtual National Laboratory 1 Overview of Heavy Ion Fusion / High Energy Density Laboratory Physics * B. Grant Logan On behalf of the Heavy Ion Fusion Science Virtual National Laboratory** (HIFS-VNL)** LBNL, LLNL, PPPL Presentation in two parts: 1. Heavy ion driven

23

Bioavailability of beta-carotene (betaC) from purple carrots is the same as typical orange carrots while high-betaC carrots increase betaC stores in Mongolian gerbils (Meriones unguiculatus)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Vitamin A (VA) deficiency is a worldwide public health problem. Biofortifying existing sources of beta-carotene (betaC) and increasing dietary betaC could help combat the issue. Two studies were performed to investigate the relative betaC bioavailability of a betaC supplement to purple, high-betaC o...

24

HYFIRE: fusion-high temperature electrolysis system  

SciTech Connect

The Brookhaven National Laboratory (BNL) is carrying out a comprehensive conceptual design study called HYFIRE of a commercial fusion Tokamak reactor, high-temperature electrolysis system. The study is placing particular emphasis on the adaptability of the STARFIRE power reactor to a synfuel application. The HYFIRE blanket must perform three functions: (a) provide high-temperature (approx. 1400/sup 0/C) process steam at moderate pressures (in the range of 10 to 30 atm) to the high-temperature electrolysis (HTE) units; (b) provide high-temperature (approx. 700 to 800/sup 0/C) heat to a thermal power cycle for generation of electricity to the HTE units; and (c) breed enough tritium to sustain the D-T fuel cycle. In addition to thermal energy for the decomposition of steam into its constitutents, H/sub 2/ and O/sub 2/, electrical input is required. Power cycle efficiencies of approx. 40% require He cooling for steam superheat. Fourteen hundred degree steam coupled with 40% power cycle efficiency results in a process efficiency (conversion of fusion energy to hydrogen chemical energy) of 50%.

Fillo, J A; Powell, J R; Steinberg, M; Benenati, R; Dang, V D; Horn, F; Isaacs, H; Lazareth, O; Makowitz, H; Usher, J

1980-01-01

25

Comparison and analysis of fusion algorithms of high resolution imagery  

NASA Astrophysics Data System (ADS)

The fusion techniques have been developed quickly in recent years and become an important remote sensing research topic. This paper systematically discusses the technique used in pixel level image fusion including IHS transform, YIQ transform, HLS transform, HSV transform, PCA transform, HPF transform and wavelet transform image fusion method. Then a fusion experiment of IKONOS image is made to compares the different merging methods from spectral quality and the spatial quality in order to choose the suitable method for the high resolution image.

Dong, Guangjun; Huang, Xiaobo; Dai, Chenguang

2008-03-01

26

GPCR Engineering Yields High-Resolution Structural Insights into beta2Adrenergic Receptor Function  

Microsoft Academic Search

The beta2-adrenergic receptor (beta2AR) is a well-studied prototype for heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptors (GPCRs) that respond to diffusible hormones and neurotransmitters. To overcome the structural flexibility of the beta2AR and to facilitate its crystallization, we engineered a beta2AR fusion protein in which T4 lysozyme (T4L) replaces most of the third intracellular loop of the GPCR (``beta2AR-T4L'') and

Daniel M. Rosenbaum; Vadim Cherezov; Michael A. Hanson; Sren G. F. Rasmussen; Foon Sun Thian; Tong Sun Kobilka; Hee-Jung Choi; Xiao-Jie Yao; William I. Weis; Raymond C. Stevens; Brian K. Kobilka

2007-01-01

27

Fusion  

NASA Astrophysics Data System (ADS)

The process in which two lighter atomic nuclei are combined to form a heavier atomic nucleus. Very high temperatures are normally required in order for atomic nuclei to collide with sufficient energy to overcome their mutual electrostatic repulsions (each atomic nucleus has a positive charge, the magnitude of which depends on the number of protons it contains). Fusion that occurs under high-tempe...

Murdin, P.

2000-11-01

28

An improved IHS fusion for high resolution remote sensing images  

NASA Astrophysics Data System (ADS)

Image fusion plays an important role in improving high resolution remote sensing images, as many Earth observation satellites provide both high-resolution panchromatic and multispectral images. To date, many image fusion techniques have been developed. Existing traditional image fusion techniques such as the intensity-hue-saturation (IHS) transform, wavelet transform and principal components analysis(PCA) methods may not be optimal for fusing the new generation commercial high-resolution satellite images such as IKONOS and Quick Bird. However, the available algorithms can hardly meet a satisfactory fusion requirement for high resolution remote sensing images. Among the existing fusion algorithms, the IHS technique is the most widely used one technique. But the color distortion of this technique is often obvious, especially when high resolution multispectral images are fused with its panchromatic images. This study presents a new fusion approach that integrates both IHS and histogram match techniques to reduce the color distortion of high resolution remote sensing fusion results. Different high resolution remote sensing images have been fused with this new approach. The result proves that the concept of the proposed improved IHS is promising, and it does significantly improve the fusion quality compared to conventional IHS transform fusion techniques.

Hu, Youjian; Zhang, Xiaohua

2010-02-01

29

Progress toward high-gain laser fusion  

SciTech Connect

A 1985-1986 Review of the US inertial confinement fusion program by the National Academy of Sciences concluded that five more years might be required to obtain enough data to determine the future course of the program. Since then, data from the Nova laser and from the Halite/Centurion program have resolved most of the outstanding problems identified by the NAS review. In particular, we now believe that we can produce a sufficiently uniform target; that we can keep the energy content in hot electrons and high-energy photons low enough (/approximately/1--10% of drive energy, depending on target design) and achieve enough pulse-shaping accuracy (/approximately/10%, with a dynamic range of 100:1) to keep the fuel on a near-Fermi-degenerate adiabat; that we can produce an /approximately/100-Mbar pressure pulse of sufficient uniformity (/approximately/1%), and can we control hydrodynamic instabilities so that the mix of the pusher into the hot spot is low enough to permit marginal ignition. These results are sufficiently encouraging that the US Department of Energy is planning to complete a 10-MJ laboratory microfusion facility to demonstrate high-gain ICF in the laboratory within a decade. 22 refs., 1 fig.

Storm, E.

1988-09-28

30

High current injector for heavy ion fusion  

SciTech Connect

A 2 MV, 800 mA, K{sup +} injector for heavy ion fusion studies is under construction. This new injector is a one-beam version of the proposed 4-beam ILSE injector. A new 36-module MARX is being built to achieve a 5 {mu}s flat top. The high voltage generator is stiff (< 5k{Omega}) to minimize effects of beam-induced transients. A large ({approx} 7 in. diameter) curved hot alumina-silicate source emits a 1 {mu}s long beam pulse through a gridless extraction electrode, and the ions are accelerated to 1 MV in a diode configuration. Acceleration to 2 MV takes place in a set of electrostatic quadrupole (ESQ) units, arranged to simultaneously focus and accelerate the ion beam. Heavy shields and other protection devices have been built in to minimize risks of high voltage breakdown. Beam aberration effects through the ESQ have been studied extensively with theory, simulations, and scaled experiments. The design, simulations, experiments, and engineering of the ESQ injector will be presented.

Yu, S.; Eylon, S.; Chupp, W.W.

1993-05-01

31

Tissue-specific expression of a FMR1/beta-galactosidase fusion gene in transgenic mice.  

PubMed

Fragile X syndrome is one of the most common genetic causes of mental retardation, yet the mechanisms controlling expression of the fragile X mental retardation gene FMR1 are poorly understood. To identify sequences regulating FMR1 transcription, transgenic mouse lines were established using a fusion gene consisting of an E.coli beta-galactosidase reporter gene (lacZ) linked to a 2.8 kb fragment spanning the 5'-region of FMR1. Five transgenic mouse lines showed lacZ expression in brain, in particular in neurons of the hippocampus and the granular layer of the cerebellum. Expression of the reporter gene was also detected in Leydig cells and spermatogonia in the testis, in many epithelia of adult mice, and in the two other steroidogenic cell types, adrenal cortex cells and ovarian follicle cells. Embryonic tissues which showed strong activity of the reporter gene included the telencephalon, the genital ridge, and the notochord. This expression pattern closely resembles the endogenous one, indicating that the 5' FMR1 gene promoter region used in this study contains most cis-acting elements regulating FMR1 transcription. PMID:7795588

Hergersberg, M; Matsuo, K; Gassmann, M; Schaffner, W; Lscher, B; Rlicke, T; Aguzzi, A

1995-03-01

32

MHD stable high beta spheromak equilibrium  

SciTech Connect

Recent observations of a pressure driven mode in CTX indicate that its performance is being limited by the low beta stability requirements typical of conventional spheromak designs. Improved designs with higher beat limits therefore have the potential to dramatically increase the temperature and lifetime of CTX and other spheromak experiments. This paper describes the results of an optimization study examining radically different geometries, but all with minimum energy current profiles which can easily be created experimentally and should be automatically stable to all ideal and resistive current drive modes. 2 refs., 3 figs.

Marklin, G.J.

1989-01-01

33

Development in DIII-D of High Beta Discharges Appropriate for Steady-state Tokamak Operation With Burning Plasmas  

Microsoft Academic Search

Ideally, tokamak power plants will operate in steady-state at high fusion gain. Recent work at DIII-D on the development of suitable high beta discharges with 100% of the plasma current generated noninductively (f{sub NI} = 1) is described. In a discharge with 1.5 < q{sub min} <2, a scan of the discharge shape squareness was used to find the value

J R Ferron; V Basiuk; T A Casper; C D Challis; J C DeBoo; E J Doyle; Q Gao; A M Garofalo; C M Greenfield; C T Holcomb; A W Hyatt; S Ide; T C Luce; M Murakami; Y Ou; T W Petrie; C C Petty; P A Politzer; H Reimerdes; E Schuster; M Schneider; A Wang

2008-01-01

34

An EMD-IHS model for high resolution image fusion  

NASA Astrophysics Data System (ADS)

High resolution image fusion is a significant focus in the field of the image processing. A new image fusion model is presented based on the characteristic level of Empirical Mode Decomposition (EMD). The IHS transform of the multi-spectral image firstly gives the intensity image. Thereafter, the 2D EMD in terms of row-column extension of the 1D EMD model was used to decompose the detail scale image and coarse scale image from the high resolution band image and the intensity image. At last, fused intensity image is obtained by reconstruction with high frequency of high-resolution image and low frequency of intensity image and IHS inverse transform result in fused image. After presenting EMD principle, multi-scale decomposition and reconstruction algorithm of 2D EMD is defined and fusion technique scheme is advanced based on EMD. Panchromatic band and multi-spectral band3,2,1 of QUICKBIRD are used to assess the quality of the fusion algorithm. After selecting appropriate Intrinsic Mode Function(IMF) for the merger on the basis of EMD analysis on specific row (colum) pixel gray value series, the fusion scheme gives fused image, which is compared with generally used fusion algorithms (Wavelet, IHS,Brovey). The objectives of image fusion include enhancing the visibility of the image and improving the spatial resolution and the spectral information of the original images. For assessing quality of an image after fusion, information entropy and standard deviation are applied to assess spatial details of the fused images and correlation coefficient, bias index and warping degree for measuring distortion between the original image and fused image in terms of spectral information. For all proposed fusion algorithms, better results are obtained when EMD algorithm is used to perform the fusion experience.

Wang, Jian; Xu, Changhui; Zhang, Jixian; Liu, Zhengjun

2007-06-01

35

Heavy ion fusion science research for high energy density physics and fusion applications  

Microsoft Academic Search

During the past two years, the U.S. heavy ion fusion science program has made significant experimental and theoretical progress in simultaneous transverse and longitudinal beam compression, ion-beam-driven warm dense matter targets, high brightness beam transport, advanced theory and numerical simulations, and heavy ion target designs for fusion. First experiments combining radial and longitudinal compression of intense ion beams propagating through

B. G. Logan; J. J. Barnard; F. M. Bieniosek; R. H. Cohen; J. E. Coleman; R. C. Davidson; P. C. Efthimion; A. Friedman; E. P. Gilson; W. G. Greenway; L. Grisham; D. P. Grote; E. Henestroza; D. H. H. Hoffmann; I. D. Kaganovich; M. K. Covo; J. W. Kwan; K. N. La Fortune; E. P. Lee; M. Leitner; S. M. Lund; A. W. Molvik; P. Ni; G. E. Penn; L. J. Perkins; H. Qin; P. K. Roy; A. B. Sefkow; P. A. Seidl; W. Sharp; E. A. Startsev; J.-L. Vay; W. L. Waldron; J. S. Wurtele; D. Welch; G. A. Westenskow; S. S. Yu

2008-01-01

36

Heavy ion fusion science research for high energy density physics and fusion applications  

Microsoft Academic Search

During the past two years, the U.S. heavy ion fusion science program has made significant experimental and theoretical progress in simultaneous transverse and longitudinal beam compression, ion-beam-driven warm dense matter targets, high brightness beam transport, advanced theory and numerical simulations, and heavy ion target designs for fusion. First experiments combining radial and longitudinal compression of intense ion beams propagating through

B. G. LOGAN; F. M. Bieniosek; J. J. Barnard; R. H. Cohen; J. E. Coleman; R. C. Davidson; P. C. Efthimion; A. Friedman; E. P. Gilson; W. G. Greenway; L. Grisham; D. P. Grote; E. Henestroza; D. H. H. Hoffmann; I. D. Kaganovich; M. Kireeff Covo; J. W. Kwan; K. N. LaFortune; E. P. Lee; M. Leitner; S. M. Lund; A. W. Molvik; P. Ni; G. E. Penn; L. J. Perkins; H. Qin; P. K. Roy; A. B. Sefkow; P. A. Seidl; W. Sharp; E. A. Startsev; D. Varentsov; J.-L. Vay; W. L. Waldron; J. S. Wurtele; D. Welch; G. A. Westenskow; S. S. Yu

2007-01-01

37

Fusion energy Fusion powers the Sun, and all stars, in which light nuclei fuse together at high temperatures  

E-print Network

Fusion energy Fusion powers the Sun, and all stars, in which light nuclei fuse together at high in excess of 100 million degrees, much higher than in the Sun. The hot hydrogen gas (known as a `plasma

38

Production and study of high-beta plasma confined by a superconducting dipole magnet  

SciTech Connect

The Levitated Dipole Experiment (LDX) [J. Kesner et al., in Fusion Energy 1998, 1165 (1999)] is a new research facility that is exploring the confinement and stability of plasma created within the dipole field produced by a strong superconducting magnet. Unlike other configurations in which stability depends on curvature and magnetic shear, magnetohydrodynamic stability of a dipole derives from plasma compressibility. Theoretically, the dipole magnetic geometry can stabilize a centrally peaked plasma pressure that exceeds the local magnetic pressure ({beta}>1), and the absence of magnetic shear allows particle and energy confinement to decouple. In initial experiments, long-pulse, quasi-steady-state microwave discharges lasting more than 10 s have been produced that are consistent with equilibria having peak beta values of 20%. Detailed measurements have been made of discharge evolution, plasma dynamics and instability, and the roles of gas fueling, microwave power deposition profiles, and plasma boundary shape. In these initial experiments, the high-field superconducting floating coil was supported by three thin supports. The plasma is created by multifrequency electron cyclotron resonance heating at 2.45 and 6.4 GHz, and a population of energetic electrons, with mean energies above 50 keV, dominates the plasma pressure. Creation of high-pressure, high-beta plasma is possible only when intense hot electron interchange instabilities are stabilized by sufficiently high background plasma density. A dramatic transition from a low-density, low-beta regime to a more quiescent, high-beta regime is observed when the plasma fueling rate and confinement time become sufficiently large.

Garnier, D.T.; Hansen, A.; Mauel, M.E.; Ortiz, E.; Boxer, A.C.; Ellsworth, J.; Karim, I.; Kesner, J.; Mahar, S.; Roach, A. [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States); Plasma Science and Fusion Center, MIT, Cambridge, Massachusetts 02139 (United States)

2006-05-15

39

Access to sustained high-beta with internal transport barrier and negative central magnetic shear in DIII-D  

SciTech Connect

High values of normalized {beta} ({beta}{sub N}{approx}4) and safety factor (q{sub min}{approx}2) have been sustained simultaneously for {approx}2 s in DIII-D [J.L. Luxon, Nucl. Fusion 42, 64 (2002)], suggesting a possible path to high fusion performance, steady-state tokamak scenarios with a large fraction of bootstrap current. The combination of internal transport barrier and negative central magnetic shear at high {beta} results in high confinement (H{sub 89P}>2.5) and large bootstrap current fraction (f{sub BS}>60%) with good alignment. Previously, stability limits in plasmas with core transport barriers have been observed at moderate values of {beta}{sub N} (<3) because of the pressure peaking which normally develops from improved core confinement. In recent DIII-D experiments, the internal transport barrier is clearly observed in the electron density and in the ion temperature and rotation profiles at {rho}{approx}0.5 but not in the electron temperature profile, which is very broad. The misalignment of T{sub i} and T{sub e} gradients may help to avoid a large local pressure gradient. Furthermore, at low internal inductance {approx}0.6, the current density gradients are close to the vessel and the ideal kink modes are strongly wall-coupled. Simultaneous feedback control of both external and internal sets of n=1 magnetic coils was used to maintain optimal error field correction and resistive wall mode stabilization, allowing operation above the free-boundary {beta} limit. Large particle orbits at high safety factor in the core help to broaden both the pressure and the beam-driven current profiles, favorable for steady-state operation. At plasma current flat top and {beta}{approx}5%, a noninductive current fraction of {approx}100% has been observed. Stability modeling shows the possibility for operation up to the ideal-wall limit at {beta}{approx}6%.

Garofalo, A.M.; Reimerdes, H. [Columbia University, New York, New York 10027 (United States); Doyle, E.J. [University of California, Los Angeles, California 90095 (United States); Ferron, J.R.; Greenfield, C.M.; Groebner, R.J.; Hyatt, A.W.; Jackson, G.L.; La Haye, R.J.; Osborne, T.H.; Petty, C.C.; Politzer, P.A.; Scoville, J.T.; St John, H.E.; Strait, E.J.; Turnbull, A.D.; Wade, M.R. [General Atomics, P.O. Box 85608, San Diego, California 92186 (United States); Jayakumar, R.J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Kinsey, J.E. [Lehigh University, Bethlehem, Pennsylvania 18015 (United States); McKee, G.R. [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)] (and others)

2006-05-15

40

Wall stabilization of high beta plasmas in DIII-D  

SciTech Connect

Detailed analysis of recent high beta discharges in the DIII-D tokamak demonstrates that the resistive vacuum vessel can provide stabilization of low n magnetohydrodynamic (MHD) modes. The experimental beta values reaching up to {beta}{sub T} = 12.6% are more than 30% larger than the maximum stable beta calculated with no wall stabilization. Plasma rotation is essential for stabilization. When the plasma rotation slows sufficiently, unstable modes with the characteristics of the predicted {open_quotes}resistive wall{close_quotes} mode are observed. Through slowing of the plasma rotation between the q = 2 and q = 3 surfaces with the application of a non-axisymmetric field, the authors have determined that the rotation at the outer rational surfaces is most important, and that the critical rotation frequency is of the order of {Omega}/2{pi} = 1 kHz.

Taylor, T.S.; Strait, E.J.; Lao, L.L.; Turnbull, A.D.; Burrell, K.H.; Chu, M.S.; Ferron, J.R.; Groebner, R.J.; La Haye, R.J. [General Atomics, San Diego, CA (United States); Mauel, M. [Columbia Univ., New York, NY (United States)] [and others

1995-02-01

41

Heavy ion fusion science research for high energy density physics and fusion applications  

NASA Astrophysics Data System (ADS)

During the past two years, the U.S. heavy ion fusion science program has made significant experimental and theoretical progress in simultaneous transverse and longitudinal beam compression, ion-beam-driven warm dense matter targets, high brightness beam transport, advanced theory and numerical simulations, and heavy ion target designs for fusion. First experiments combining radial and longitudinal compression of intense ion beams propagating through background plasma resulted in on-axis beam densities increased by 700X at the focal plane. With further improvements planned in 2007, these results will enable initial ion beam target experiments in warm dense matter to begin next year at LBNL. We are assessing how these new techniques apply to low-cost modular fusion drivers and higher-gain direct-drive targets for inertial fusion energy.

Logan, B. G.; Barnard, J. J.; Bieniosek, F. M.; Cohen, R. H.; Coleman, J. E.; Davidson, R. C.; Efthimion, P. C.; Friedman, A.; Gilson, E. P.; Greenway, W. G.; Grisham, L.; Grote, D. P.; Henestroza, E.; Hoffmann, D. H. H.; Kaganovich, I. D.; Covo, M. K.; Kwan, J. W.; La Fortune, K. N.; Lee, E. P.; Leitner, M.; Lund, S. M.; Molvik, A. W.; Ni, P.; Penn, G. E.; Perkins, L. J.; Qin, H.; Roy, P. K.; Sefkow, A. B.; Seidl, P. A.; Sharp, W.; Startsev, E. A.; Vay, J.-L.; Waldron, W. L.; Wurtele, J. S.; Welch, D.; Westenskow, G. A.; Yu, S. S.

2008-05-01

42

Heavy ion fusion science research for high energy density physics and fusion applications  

SciTech Connect

During the past two years, the U.S. heavy ion fusion science program has made significant experimental and theoretical progress in simultaneous transverse and longitudinal beam compression, ion-beam-driven warm dense matter targets, high brightness beam transport, advanced theory and numerical simulations, and heavy ion target designs for fusion. First experiments combining radial and longitudinal compression of intense ion beams propagating through background plasma resulted in on-axis beam densities increased by 700X at the focal plane. With further improvements planned in 2007, these results will enable initial ion beam target experiments in warm dense matter to begin next year at LBNL. We are assessing how these new techniques apply to low-cost modular fusion drivers and higher-gain direct-drive targets for inertial fusion energy.

LOGAN, B.G.; Logan, B.G.; Bieniosek, F.M.; Barnard, J.J.; Cohen, R.H.; Coleman, J.E.; Davidson, R.C.; Efthimion, P.C.; Friedman, A.; Gilson, E.P.; Greenway, W.G.; Grisham, L.; Grote, D.P.; Henestroza, E.; Hoffmann, D.H.H.; Kaganovich, I.D.; Kireeff Covo, M.; Kwan, J.W.; LaFortune, K.N.; Lee, E.P.; Leitner, M.; Lund, S.M.; Molvik, A.W.; Ni, P.; Penn, G.E.; Perkins, L.J.; Qin, H.; Roy, P.K.; Sefkow, A.B.; Seidl, P.A.; Sharp, W.; Startsev, E.A.; Varentsov, D.; Vay, J.-L.; Waldron, W.L.; Wurtele, J.S.; Welch, D.; Westenskow, G.A.; Yu, S.S.

2007-06-25

43

Physics issues in the design of high-beta, low-aspect-ratio stellarator experiments  

SciTech Connect

High-beta, low-aspect-ratio (''compact'') stellarators are promising solutions to the problem of developing a magnetic plasma configuration for magnetic fusion power plants that can be sustained in steady state without disrupting. These concepts combine features of stellarators and advanced tokamaks and have aspect ratios similar to those of tokamaks (2-4). They are based on computed plasma configurations that are shaped in three dimensions to provide desired stability and transport properties. Experiments are planned as part of a program to develop this concept. A {beta}=4% quasi-axisymmetric plasma configuration has been evaluated for the National Compact Stellarator Experiment (NCSX). It has a substantial bootstrap current and is shaped to stabilize ballooning, external kink, vertical, and neoclassical tearing modes without feedback or close-fitting conductors. Quasi-omnigeneous plasma configurations stable to ballooning modes at {beta}=4% have been evaluated for the Quasi-Omnigeneous Stellarator (QOS) experiment. These equilibria have relatively low bootstrap currents and are insensitive to changes in beta. Coil configurations have been calculated that reconstruct these plasma configurations, preserving their important physics properties. Theory- and experiment-based confinement analyses are used to evaluate the technical capabilities needed to reach target plasma conditions. The physics basis for these complementary experiments is described. (c) 2000 American Institute of Physics.

Neilson, G. H. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Reiman, A. H. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Zarnstorff, M. C. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Brooks, A. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Fu, G.-Y. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Goldston, R. J. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Ku, L.-P. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Lin, Z. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Majeski, R. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Monticello, D. A. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] (and others) [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

2000-05-01

44

Physics Basis for High-Beta, Low-Aspect-Ratio Stellarator Experiments  

SciTech Connect

High-beta, low-aspect-ratio (compact) stellarators are promising solutions to the problem of developing a magnetic plasma configuration for magnetic fusion power plants that can be sustained in steady-state without disrupting. These concepts combine features of stellarators and advanced tokamaks and have aspect ratios similar to those of tokamaks (2-4). They are based on computed plasma configurations that are shaped in three dimensions to provide desired stability and transport properties. Experiments are planned as part of a program to develop this concept. A beta = 4% quasi-axisymmetric plasma configuration has been evaluated for the National Compact Stellarator Experiment (NCSX). It has a substantial bootstrap current and is shaped to stabilize ballooning, external kink, vertical, and neoclassical tearing modes without feedback or close-fitting conductors. Quasi-omnigeneous plasma configurations stable to ballooning modes at beta = 4% have been evaluated for the Quasi-Omnigeneous Stellarator (QOS) experiment. These equilibria have relatively low bootstrap currents and are insensitive to changes in beta. Coil configurations have been calculated that reconstruct these plasma configurations, preserving their important physics properties. Theory- and experiment-based confinement analyses are used to evaluate the technical capabilities needed to reach target plasma conditions. The physics basis for these complementary experiments is described.

A. Brooks; A.H. Reiman; G.H. Neilson; M.C. Zarnstorff; et al

1999-11-01

45

High-Resolution Crystal Structure of an Engineered Human beta2Adrenergic G Protein-Coupled Receptor  

Microsoft Academic Search

Heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptors constitute the largest family of eukaryotic signal transduction proteins that communicate across the membrane. We report the crystal structure of a human beta2-adrenergic receptor-T4 lysozyme fusion protein bound to the partial inverse agonist carazolol at 2.4 angstrom resolution. The structure provides a high-resolution view of a human G protein-coupled receptor bound to a

Vadim Cherezov; Daniel M. Rosenbaum; Michael A. Hanson; Sren G. F. Rasmussen; Foon Sun Thian; Tong Sun Kobilka; Hee-Jung Choi; Peter Kuhn; William I. Weis; Brian K. Kobilka; Raymond C. Stevens

2007-01-01

46

Wnt-independent activation of beta-catenin mediated by a Dkk1-Fz5 fusion protein.  

PubMed

An XWnt8-Fz5 fusion protein synergizes with LRP6 to potently activate beta-catenin-dependent signaling. Here, we generated a fusion in which XWnt8 was fused to the N-terminus of LRP6 and show it synergizes with both Fz4 and Fz5 to potently transactivate beta-catenin-dependent Wnt signaling. Based on this, we hypothesized that the main function of Wnt is to nucleate the formation of a physical complex between LRP6 and a Frizzled. Dkk1, but not the related Dkk3, binds LRP6 and inhibits canonical Wnt signaling by blocking the interaction of Wnt and LRP6. Therefore, we reasoned that a covalent fusion of Dkk1 to Fz5 (Dkk1-Fz5) would mimic Wnt ligand by nucleating the formation of a complex containing Fz5 and LRP6, while Dkk3 (Dkk3-Fz5) would not. We found that Dkk1-Fz5, but not Dkk3-Fz5, potently synergized with LRP6 to activate signaling in a dishevelled-dependent manner. PMID:15694380

Holmen, Sheri L; Robertson, Scott A; Zylstra, Cassandra R; Williams, Bart O

2005-03-11

47

An oncogenic fusion product of the phosphatidylinositol 3-kinase p85beta subunit and HUMORF8, a putative deubiquitinating enzyme.  

PubMed

Peripheral blood cell DNA from a patient with a chronic myeloproliferative disorder was tested in the tumorigenicity assay. Upon tumor induction in nude mice we isolated a human oncogene by means of genomic cloning, exon trap analysis and cDNA cloning. Sequence analysis revealed a fusion product of the p85beta subunit of phosphatidylinositol (PI) 3-kinase and HUMORF8, a putative deubiquitinating enzyme, which has been generated during the DNA transfection process. Application of the tumorigenicity assay to various p85beta and HUMORF8 cDNA constructs indicated that the recombination of both genes rather than the truncation of one of the fusion partners renders the chimeric protein tumorigenic. Moreover, sequence analysis of human wildtype p85beta revealed an alanine for serine substitution at a site important for the regulation of the lipid kinase activity of PI 3-kinase in human p85alpha. This variation may relate to differences in the mode of signal transduction from both p85 isoforms. PMID:9582025

Janssen, J W; Schleithoff, L; Bartram, C R; Schulz, A S

1998-04-01

48

Measures of effectiveness for high-level fusion  

Microsoft Academic Search

Current advances in technology, sensor collection, data storage, and data distribution have afforded more complex, distributed, and operational information fusion systems (IFSs). IFSs notionally consist of low-level (data collection, registration, and association in time and space) and high-level fusion (user coordination, situational awareness, and mission control). Low-level IFSs typically rely on standard metrics for evaluation such as timeliness, accuracy, and

Erik Blasch; Pierre Valin; Eloi Bosse

2010-01-01

49

High power millimeter wave ECRH source needs for fusion program  

SciTech Connect

This document stems from the four-day Gyrotron Symposium held at the US Department of Energy (DOE) Headquarters on June 13-16, 1983, and serves as a position paper for the Office of Fusion Energy, DOE, on high-power millimeter wave source development for Electron Cyclotron Heating (ECH) of plasmas. It describes the fusion program needs for gyrotron as ECH sources, their current status, and desirable development strategies.

Not Available

1984-06-01

50

A post-transcriptional mechanism contributes to circadian cycling of a per-beta-galactosidase fusion protein.  

PubMed Central

The period gene (per) of Drosophila melanogaster affects circadian rhythms. Circadian fluctuations in per mRNA levels are thought to contribute to circadian fluctuations in per protein levels in the heads of adult flies. To address the mechanisms underlying these oscillatory phenomena, we have analyzed RNA and protein cycling from two per-beta-galactosidase fusion genes. These studies demonstrate that 5' noncoding sequences from per are sufficient to cause the fusion mRNA levels to cycle in a wild-type (rhythmic) background. Protein cycling requires additional sequences derived from the per coding region. The data suggest that there is a per-dependent posttranscriptional mechanism that is under circadian clock control required for per protein levels to fluctuate in a rhythmic fashion. Images PMID:1902573

Zwiebel, L J; Hardin, P E; Liu, X; Hall, J C; Rosbash, M

1991-01-01

51

Modular low-aspect-ratio high-beta torsatron  

DOEpatents

A fusion-reactor device is described which the toroidal magnetic field and at least a portion of the poloidal magnetic field are provided by a single set of modular coils. The coils are arranged on the surface of a low-aspect-ratio toroid in planed having the cylindrical coordinate relationship phi = phi/sub i/ + kz, where k is a constant equal to each coil's pitch and phi/sub i/ is the toroidal angle at which the i'th coil intersects the z = o plane. The toroid defined by the modular coils preferably has a race track minor cross section. When vertical field coils and, preferably, a toroidal plasma current are provided for magnetic-field-surface closure within the toroid, a vacuum magnetic field of racetrack-shaped minor cross section with improved stability and beta valves is obtained.

Sheffield, G.V.

1982-04-01

52

Towards fusion technique for astronomical images with high dynamic range  

NASA Astrophysics Data System (ADS)

Astronomical detection always need high dynamic range image, but there are problems such as underexposure or overexposure in astronomical images taken by commercial camera, this paper proposed the technique that combine establishing the first order difference quotient curve of each pixel with data feature positioning to calculate optimal exposure value of each pixel, which achieves high dynamic range fusion. In this paper, data feature positioning method was firstly utilized to establish mathematical model to calculate optimal exposure point in the first order difference quotient curve of each pixel in the target scene. Correlate optimal exposure point and camera response function to calculate optimal brightness value of each pixel, the fused high dynamic range image will be achieved. Finally, take a series of low dynamic range images with different exposure value by commercial camera, establish mathematical model and calculate to achieve high dynamic range fusion, which verifies the fusion technique proposed in this paper can obtain high dynamic range astronomical images effectively.

Du, Lin; Sun, Huayan; Hou, Zhaofei; Qi, Yingying

2014-08-01

53

Galectin-1 as a fusion partner for the production of soluble and folded human {beta}-1,4-galactosyltransferase-T7 in E. coli  

SciTech Connect

The expression of recombinant proteins in Escherichia coli often leads to inactive aggregated proteins known as the inclusion bodies. To date, the best available tool has been the use of fusion tags, including the carbohydrate-binding protein; e.g., the maltose-binding protein (MBP) that enhances the solubility of recombinant proteins. However, none of these fusion tags work universally with every partner protein. We hypothesized that galectins, which are also carbohydrate-binding proteins, may help as fusion partners in folding the mammalian proteins in E. coli. Here we show for the first time that a small soluble lectin, human galectin-1, one member of a large galectin family, can function as a fusion partner to produce soluble folded recombinant human glycosyltransferase, {beta}-1,4-galactosyltransferase-7 ({beta}4Gal-T7), in E. coli. The enzyme {beta}4Gal-T7 transfers galactose to xylose during the synthesis of the tetrasaccharide linker sequence attached to a Ser residue of proteoglycans. Without a fusion partner, {beta}4Gal-T7 is expressed in E. coli as inclusion bodies. We have designed a new vector construct, pLgals1, from pET-23a that includes the sequence for human galectin-1, followed by the Tev protease cleavage site, a 6x His-coding sequence, and a multi-cloning site where a cloned gene is inserted. After lactose affinity column purification of galectin-1-{beta}4Gal-T7 fusion protein, the unique protease cleavage site allows the protein {beta}4Gal-T7 to be cleaved from galectin-1 that binds and elutes from UDP-agarose column. The eluted protein is enzymatically active, and shows CD spectra comparable to the folded {beta}4Gal-T1. The engineered galectin-1 vector could prove to be a valuable tool for expressing other proteins in E. coli.

Pasek, Marta [Structural Glycobiology Section, SAIC-Frederick, Inc., Center for Cancer Research Nanobiology Program, Center for Cancer Research, NCI-Frederick, Frederick, MD 2170 (United States)] [Structural Glycobiology Section, SAIC-Frederick, Inc., Center for Cancer Research Nanobiology Program, Center for Cancer Research, NCI-Frederick, Frederick, MD 2170 (United States); Boeggeman, Elizabeth; Ramakrishnan, Boopathy [Structural Glycobiology Section, SAIC-Frederick, Inc., Center for Cancer Research Nanobiology Program, Center for Cancer Research, NCI-Frederick, Frederick, MD 2170 (United States) [Structural Glycobiology Section, SAIC-Frederick, Inc., Center for Cancer Research Nanobiology Program, Center for Cancer Research, NCI-Frederick, Frederick, MD 2170 (United States); Basic Science Program, SAIC-Frederick, Inc., Center for Cancer Research Nanobiology Program, Center for Cancer Research, NCI-Frederick, Frederick, MD 2170 (United States); Qasba, Pradman K., E-mail: qasba@helix.nih.gov [Structural Glycobiology Section, SAIC-Frederick, Inc., Center for Cancer Research Nanobiology Program, Center for Cancer Research, NCI-Frederick, Frederick, MD 2170 (United States)

2010-04-09

54

Production and study of high-beta plasma confined by a superconducting dipole magneta)  

NASA Astrophysics Data System (ADS)

The Levitated Dipole Experiment (LDX) [J. Kesner et al., in Fusion Energy 1998, 1165 (1999)] is a new research facility that is exploring the confinement and stability of plasma created within the dipole field produced by a strong superconducting magnet. Unlike other configurations in which stability depends on curvature and magnetic shear, magnetohydrodynamic stability of a dipole derives from plasma compressibility. Theoretically, the dipole magnetic geometry can stabilize a centrally peaked plasma pressure that exceeds the local magnetic pressure (?>1), and the absence of magnetic shear allows particle and energy confinement to decouple. In initial experiments, long-pulse, quasi-steady-state microwave discharges lasting more than 10s have been produced that are consistent with equilibria having peak beta values of 20%. Detailed measurements have been made of discharge evolution, plasma dynamics and instability, and the roles of gas fueling, microwave power deposition profiles, and plasma boundary shape. In these initial experiments, the high-field superconducting floating coil was supported by three thin supports. The plasma is created by multifrequency electron cyclotron resonance heating at 2.45 and 6.4GHz, and a population of energetic electrons, with mean energies above 50keV, dominates the plasma pressure. Creation of high-pressure, high-beta plasma is possible only when intense hot electron interchange instabilities are stabilized by sufficiently high background plasma density. A dramatic transition from a low-density, low-beta regime to a more quiescent, high-beta regime is observed when the plasma fueling rate and confinement time become sufficiently large.

Garnier, D. T.; Hansen, A.; Mauel, M. E.; Ortiz, E.; Boxer, A. C.; Ellsworth, J.; Karim, I.; Kesner, J.; Mahar, S.; Roach, A.

2006-05-01

55

Training The Next Generation Of Fusion Scientists And Engineers: Summer High School Fusion Science Workshop  

NASA Astrophysics Data System (ADS)

The goal of the education and outreach activities of the Hampton University Center for Fusion Research and Training (HU CFRT) is to create a high school-to-Ph.D. pipeline in plasma physics, fusion science, and related sciences for underrepresented minorities and female students. The HU CFRT Summer High School Fusion Research Workshop is an integral component of this pipeline. This workshop has been extraordinarily successful. The workshop participants are chosen from a national pool of young and talented minority and female high school students through the NASA SHARP program. These students come to HU from all over US and its possessions for eight weeks during the summer. Over the last ten years, these workshops have provided one-on-one high quality research experiences in fusion science to the best and the brightest minority and female high school students in the nation. Our high school students have presented over 25 contributed papers at APS/DPP annual meetings, twice reached semi-finalist positions in Siemens-Westinghouse competitions, won awards and prizes, admissions and scholarships to prestigious universities, and won high praises from the fusion research community and other educators and researchers. We wish to emphasize that we have been able to achieve these results with limited human and fiscal resources and a meager infrastructure. Here we will present the details of how this workshop has evolved over the years, the approaches, the activities, and the structure that we have used to train, motivate, and provide valuable research experiences to the next generation of our national leaders in science. We thank the U.S. DOE OFES for supporting these efforts. We also thank Dr. Allen Boozer and Dr. Thomas Simonen for their invaluable help in the workshop and in all our efforts.

Punjabi, Alkesh

2005-10-01

56

Heat transport in PBX-M high beta p plasmas  

Microsoft Academic Search

High poloidal beta discharges in PBX-M routinely enter the H mode regime: typically, a quiescent phase followed by an MHD-active phase characterize the H mode period. An analysis of the energy transport during these phases is conducted using the experimental data and the code TRANSP; effective thermal diffusivities are computed. The quiescent H phase is characterized by a decrease of

B. LeBlanc; S. M. Kaye; N. Asakura; R. E. Bell; P.-A. Duperrex; G. M. Gammel; H. Fishman; R. E. Hatcher; A. Holland; R. Kaita; C. E. Kessel; H. W. Kugel; F. M. Levinton; M. Okabayashi; S. F. Paul; N. R. Sauthoff; S. Sesnic; H. Takahashi

1993-01-01

57

Internal Kink Mode Dynamics in High-{beta} NSTX Plasmas  

SciTech Connect

Saturated internal kink modes have been observed in many of the highest toroidal beta discharges of the National Spherical Torus Experiment (NSTX). These modes often cause rotation flattening in the plasma core, can degrade energy confinement, and in some cases contribute to the complete loss of plasma angular momentum and stored energy. Characteristics of the modes are measured using soft X-ray, kinetic profile, and magnetic diagnostics. Toroidal flows approaching Alfvenic speeds, island pressure peaking, and enhanced viscous and diamagnetic effects associated with high-beta may contribute to mode nonlinear stabilization. These saturation mechanisms are investigated for NSTX parameters and compared to experimental data.

J.E. Menard; R.E. Bell; E.D. Fredrickson; D.A. Gates; S.M. Kaye; B.P. LeBlanc; S.S. Medley; W. Park; S.A. Sabbagh; A. Sontag; D. Stutman; K. Tritz; W. Zhu; the NSTX Research Team

2004-12-22

58

Internal Kink Mode Dynamics in High-beta NSTX Plasmas  

SciTech Connect

Saturated internal kink modes have been observed in many of the highest toroidal {beta} discharges of the National Spherical Torus Experiment (NSTX). These modes often cause rotation flattening in the plasma core, can degrade energy confinement, and in some cases contribute to the complete loss of plasma angular momentum and stored energy. Characteristics of the modes are measured using soft X-ray, kinetic profile, and magnetic diagnostics. Toroidal flows approaching Alfvenic speeds, island pressure peaking, and enhanced viscous and diamagnetic effects associated with high-{beta} may contribute to mode nonlinear stabilization. These saturation mechanisms are investigated for NSTX parameters and compared to experimental data.

J.E. Menard; R.E. Bell; E.D. Fredrickson; D.A. Gates; S.M. Kaye; B.P. LeBlanc; S.S. Medley; W. Park; S.A. Sabbagh; A. Sontag; D. Stutman; K. Tritz; W. Zhu; the NSTX Research Team

2004-12-22

59

Formation of High-Beta Plasma and Stable Confinement of Toroidal Electron Plasma in RT-1  

NASA Astrophysics Data System (ADS)

The Ring Trap 1 (RT-1) device is a laboratory magnetosphere generated by a levitated superconducting magnet. The goals of RT-1 are to realize stable formation of ultra high-beta plasma suitable for burning advanced fusion fuels, and confinement of toroidal non-neutral plasmas including antimatter particles. RT- 1 has produced high-beta plasma in the magnetospheric configuration. The effects of coil levitation and geomagnetic field compensation [Y. Yano et al., Plasma Fusion Res. 4, 039] resulted drastic improvements of the plasma properties, and a maximum local beta value exceeded 70%. Because plasma is generated by electron cyclotron resonance heating (ECH) in the present experiment, the plasma pressure is mainly due to hot electrons, whose bremsstrahlung was observed with an x-ray CCD camera. The pressure profiles have rather steep gradient near the superconducting coil in the strong field region. The decay rates of magnetic probe and interferometer signals have different time constants, suggesting multiple temperature components. The energy confinement time estimated from the input RF power and stored magnetic energy is on the order of 1s, which is comparable to the decay time constant of the density of hot electron component. Pure electron plasma experiments are also conducted in RT-1. Radial profiles of electrostatic potential and electron density showed that the plasma rigidly rotates in the toroidal direction in the stable confinement phase. Long time confinement of toroidal non- neutral plasma for more than 300s and inward particle diffusion to strong field regions, caused by the activation of the diocotron (Kelvin-Helmholtz) instability, have been realized [Z. Yoshida et al., Phys. Rev. Lett. 104, 235004].

Saitoh, Haruhiko

2010-11-01

60

The Beta Pictoris circumstellar disk. XV - Highly ionized species near Beta Pictoris  

NASA Technical Reports Server (NTRS)

Temporal variations of the Fe II, Mg II, and Al III circumstellar lines towards Beta Pictoris have been detected and monitored since 1985. However, the unusual presence of Al III ions is still puzzling, since the UV stellar flux from an A5V star such as Beta Pic is insufficient to produce such an ion. In order to better define the origin of such a phenomenon, new observations have been carried out to detect faint signatures of other highly ionized species in the short UV wavelength range, where the stellar continuum flux is low. These observations reveal variations not only near the C IV doublet lines, but also in C I and Al II lines, two weakly ionized species, not clearly detectable until now. In the framework of an infalling body scenario, highly ionized species would be created in the tail, far from the comet head, by collisions with ambient gas surrounding the star, or a weak stellar wind. Spectral changes have also been detected near a CO molecular band location, which, if confirmed, would provide the first molecular signature around Beta Pictoris.

Deleuil, M.; Gry, C.; Lagrange-Henri, A.-M.; Vidal-Madjar, A.; Beust, H.; Ferlet, R.; Moos, H. W.; Livengood, T. A.; Ziskin, D.; Feldman, P. D.

1993-01-01

61

SUPPORT FOR HU CFRT SUMMER HIGH SCHOOL FUSION WORKSHOP  

SciTech Connect

Nine summer fusion science research workshops for minority and female high school students were conducted at the Hampton University Center for Fusion Research and Training from 1996 to 2005. Each workshop was of the duration of eight weeks. In all 35 high school students were mentored. The students presented 28 contributed papers at the annual meetings of the American Physical Society Division of Plasma Physics. These contributed papers were very well received by the plasma physics and fusion science research community. The students won a number of prestigious local, state, and national honors, awards, prizes, and scholarships. The notable among these are the two regional finalist positions in the 1999 Siemens-Westinghouse Science and Technology Competitions; 1st Place U.S. Army Award, 2006; 1st Place U.S. Naval Science Award, 2006; Yale Science and Engineering Association Best 11th Grade Project, 2006; Society of Physics Students Book Award, 2006; APS Corporate Minority Scholarship and others. This workshop program conducted by the HU CFRT has been an exemplary success, and served the minority and female students exceptionally fruitfully. The Summer High School Fusion Science Workshop is an immensely successful outreach activity conducted by the HU CFRT. In this workshop, we train, motivate, and provide high quality research experiences to young and talented high school scholars with emphasis on under-represented minorities and female students in fusion science and related areas. The purpose of this workshop is to expose minority and female students to the excitement of research in science at an early stage in their academic lives. It is our hope that this may lead the high school students to pursue higher education and careers in physical sciences, mathematics, and perhaps in fusion science. To our knowledge, this workshop is the first and only one to date, of fusion science for under-represented minorities and female high school students at an HBCU. The faculty researchers in the HU CFRT mentor the students during summers. Mentors spend a considerable amount of time and efforts in training, teaching, guiding and supervising research projects. The HU CFRT has so far conducted nine workshops during the summers of 1996-2000 and 2002-2005. The first workshop was conducted in summer 1996. Students for the workshop are chosen from a national pool of exceptionally talented high school rising seniors/juniors. To our knowledge, most of these students have gone on to prestigious universities such as Duke University, John Hopkins University, CalTech, UCLA, Hampton University, etc. after completing their high school. For instance, Tiffany Fisher, participant of the 1996 summer workshop completed her BS in Mathematics at Hampton University in May 2001. She then went on to Wake Forest University at Winston-Salem, North Carolina to pursue graduate studies. Anshul Haldipur, participant of the 1999 summer workshop, began his undergraduate studies at Duke University in 2000. Christina Nguyen and Ilissa Martinez, participants of the 2000 summer workshop, are pursuing their undergraduate degrees at the UCLA and Florida State University respectively. The organizing committee of the APS DPP annual meeting invited Dr. Punjabi to deliver an invited talk on training the next generation of fusion scientists and engineers at the 2005 APS DPP meeting in Denver, CO. The organizing committee distributed a special flier with the Bulletin to highlight this invited talk and another talk on education as well the expo. This has given wide publicity and recognition to our workshops and Hampton University. Prof. Punjabi's talk: 'LI2 2: Training the next generation of fusion scientists and engineers: summer high school fusion science workshop, Bull. Amer. Phys. Soc. 50, 221 (2005)' was very well-received. He talked about HU education and outreach initiative and the HU CFRT Summer High School Workshop. The audience had a considerable number of questions about our workshops and the High School to PhD Pipeline in fusion science. Professor William Mathews of

Punjabi, Alkesh

2010-02-09

62

Materials integration issues for high performance fusion power systems.  

SciTech Connect

One of the primary requirements for the development of fusion as an energy source is the qualification of materials for the frost wall/blanket system that will provide high performance and exhibit favorable safety and environmental features. Both economic competitiveness and the environmental attractiveness of fusion will be strongly influenced by the materials constraints. A key aspect is the development of a compatible combination of materials for the various functions of structure, tritium breeding, coolant, neutron multiplication and other special requirements for a specific system. This paper presents an overview of key materials integration issues for high performance fusion power systems. Issues such as: chemical compatibility of structure and coolant, hydrogen/tritium interactions with the plasma facing/structure/breeder materials, thermomechanical constraints associated with coolant/structure, thermal-hydraulic requirements, and safety/environmental considerations from a systems viewpoint are presented. The major materials interactions for leading blanket concepts are discussed.

Smith, D. L.

1998-01-14

63

A ultra-high-vacuum wafer-fusion-bonding system.  

PubMed

The design of heterojunction devices is typically limited by material integration constraints and the energy band alignment. Wafer bonding can be used to integrate material pairs that cannot be epitaxially grown together due to large lattice mismatch. Control of the energy band alignment can be provided by formation of interface dipoles through control of the surface chemistry. We have developed an ultra-high-vacuum system for wafer-fusion-bonding semiconductors with in situ control and measurement of surface properties relevant to interface dipoles. A wafer-fusion-bonding chamber with annealing capabilities was integrated into an ultra-high-vacuum system with a sputtering chamber and an x-ray photoelectron spectroscopy system for preparing and measuring the surface chemistry of wafers prior to bonding. The design of the system along with initial results for the fusion-bonded InGaAs/Si heterojunction is presented. PMID:22667658

McKay, Kyle; Wolter, Scott; Kim, Jungsang

2012-05-01

64

An efficient expression of Human Growth Hormone (hGH) in the milk of transgenic mice using rat {beta}-casein/hGH fusion genes  

SciTech Connect

In order to produce human growth hormone (hGH) in the milk of transgenic mice, two expression vectors for hGH differing in their 3{prime} flanking sequences were constructed by placing the genomic sequences of hGH gene under the control of the rat {beta}-casein gene promotor. The 3{prime} flanking sequences of the expression constructs were derived from either the hGH gene (pBCN1GH) or the rat {beta}-casein gene (pBCN2GH). Transgenic lines bearing pBCN1GH expressed hGH more efficiently than those bearing pBCN2GH in the milk (19-5500 {mu}g/mL vs 0.7-2 {mu}g/mL). In particular, one of the BCN1GH lines expressed hGH as much as 5500 {plus_minus} 620 {mu}g/mL. Northern blot analysis showed that the transgene expression was specifically confined to the mammary gland and developmentally regulated like the endogeneous mouse {beta}-casein gene in the mammary gland. However, a low level of nonmammary expression was also detected with more sensitive assay methods. In conclusion, the rat {beta}-casein/hGH fusion gene could direct an efficient production of hGH in a highly tissue- and stage-specific manner in the transgenic mice and the 3{prime} flanking sequences of hGH gene had an important role for the efficient expression. 27 refs., 5 figs., 2 tabs.

Lee, Chul-Sang; Yu, Dae-Yeul; Lee, Kyung-Kwang [Korea Research Institute of Bioscience and Biotechnology, Taejon (Korea, Republic of)] [and others

1996-03-01

65

High beta and second stability region transport and stability analysis  

SciTech Connect

This report describes ideal and resistive studies of high-beta plasmas and of the second stability region. Emphasis is focused on supershot'' plasmas in TFIR where MHD instabilities are frequently observed and which spoil their confinement properties. Substantial results are described from the analysis of these high beta poloidal plasmas. During these studies, initial pressure and safety factor profiles were obtained from the TRANSP code, which is used extensively to analyze experimental data. Resistive MBD stability studies of supershot equilibria show that finite pressure stabilization of tearing modes is very strong in these high {beta}p plasmas. This has prompted a detailed re-examination of linear tearing mode theory in which we participated in collaboration with Columbia University and General Atomics. This finite pressure effect is shown to be highly sensitive to small scale details of the pressure profile. Even when an ad hoc method of removing this stabilizing mechanism is implemented, however, it is shown that there is only superficial agreement between resistive MBD stability computation and the experimental data. While the mode structures observed experimentally can be found computationally, there is no convincing correlation with the experimental observations when the computed results are compared with a large set of supershot data. We also describe both the ideal and resistive stability properties of TFIR equilibria near the transition to the second region. It is shown that the highest {beta} plasmas, although stable to infinite-n ideal ballooning modes, can be unstable to the so called infernal'' modes associated with small shear. The sensitivity of these results to the assumed pressure and current density profiles is discussed. Finally, we describe results from two collaborative studies with PPPL. The first involves exploratory studies of the role of the 1/1 mode in tokamaks and, secondly, a study of sawtooth stabilization using ICRF.

Hughes, M.H.; Phillps, M.W.; Todd, A.M.M.; Krishnaswami, J.; Hartley, R.

1992-09-01

66

Inertial Confinement Fusion Ignition and High Yield Campaign  

E-print Network

Inertial Confinement Fusion Ignition and High Yield Campaign SNL Z Facility UR/LLE OMEGA Dr. David November 21, 2003 #12;2 Statements to FESAC IFE panel 10/28/03 · Ignition is a major goal for NNSA/Defense Programs and will be a major focus · Defense Programs does not have an energy mission, but ignition

67

HYFIRE - Fusion-high temperature electrolysis system  

Microsoft Academic Search

HYFIRE is the comprehensive conceptual design study of a commercial tokamak reactor, high-temperature electrolysis system. Particular emphasis is placed on the adaptability of the STARFIRE power reactor to a synfuel application. The HYFIRE blanket must perform three functions: (1) provide high-temperature (about 1400 C) process steam at moderate pressures (10-30 atm) to the high-temperature electrolysis (HTE) units, (2) provide high-temperature

J. A. Fillo; J. R. Powell; M. Steinberg; R. Benenati; V.-D. Dang; F. Horn; H. Isaacs; O. Lazareth; H. Makowitz; J. Usher

1980-01-01

68

High density regimes and beta limits in JET  

SciTech Connect

Results are first presented on the density limit in JET discharges with graphite (C), Be gettered graphite and Be limiters. There is a clear improvement in the case of Be limiters. The Be gettered phase showed no increase in the gas fueled density limit, except with Ion Cyclotron Resonance Heating (ICRH), but, the limit changed character. During MARFE-formation, any further increase in density was prevented, leading to a soft density limit. The soft density limit was a function of input power and impurity content with a week dependence on q. Helium and pellet fuelled discharges exceeded the gas-fuelled global density limits, but essentially had the same edge limit. In the second part, results are presented of high {beta} operation in low-B Double-Null (DN) X-point configurations with Be-gettered carbon target plates. The Troyon limit was reached during H-mode discharges and toroidal {beta} values of 5.5% were obtained. At high beta, the sawteeth were modified and characterised by very rapid heat-waves and fishbone-like pre- and post-cursors with strongly ballooning character. 17 refs., 5 figs.

Smeulders, P.

1990-01-01

69

Suppression of established experimental autoimmune encephalomyelitis and formation of meningeal lymphoid follicles by lymphotoxin beta receptor-Ig fusion protein.  

PubMed

We have recently shown that de novo formation of lymphoid structures resembling B-cell follicles occurs in the inflamed central nervous system (CNS) meninges in a subset of patients with secondary progressive multiple sclerosis and in SJL mice with relapsing-remitting experimental autoimmune encephalomyelitis (EAE). Because lymphotoxin (LT) alpha(1)beta(2) is essential for lymphoid tissue organization, we used real-time PCR to examine LTbeta and LTbeta receptor (LTbetaR) gene expression in the CNS of SJL mice immunized with PLP 139-151 peptide. Moreover, we used the decoy receptor LTbetaR-immunoglobulin fusion protein to block the interaction of lymphotoxin (LT) alpha(1)beta(2) with the LTbeta receptor (LTbetaR) in mice with established EAE and evaluate the effect of systemic and local treatments with the fusion protein on disease progression, CNS lymphocytic infiltration and formation of meningeal B-cell follicles. The present findings indicate that both LTbeta and LTbetaR are upregulated at EAE onset and during subsequent relapses and that systemic and local blockade of the LT pathway with LTbetaR-Ig results in protracted and transient inhibition of EAE clinical signs, respectively. LTbetaR-Ig treatment also reduces T- and B-cell infiltration and prevents the induction of the chemokines CXCL10 and CXCL13 and the formation of organized ectopic follicles in the EAE-affected CNS. Targeting of molecules involved in lymphoid organogenesis could represent a valid strategy to inhibit CNS inflammation and formation of ectopic follicles, which may play a role in maintaining an abnormal, intrathecal humoral immune response in CNS autoimmune disease. PMID:16870269

Columba-Cabezas, Sandra; Griguoli, Marilena; Rosicarelli, Barbara; Magliozzi, Roberta; Ria, Francesco; Serafini, Barbara; Aloisi, Francesca

2006-10-01

70

Fully electromagnetic gyrokinetic eigenmode analysis of high-beta shaped plasmas  

NASA Astrophysics Data System (ADS)

A new, more efficient method to compute unstable linear gyrokinetic eigenvalues and eigenvectors has been developed for drift-wave analysis of plasmas with arbitrary flux-surface shape, including both transverse and compressional magnetic perturbations. In high-beta, strongly shaped plasmas like in the National Spherical Torus Experiment (NSTX) [M. Ono et al., Nucl. Fusion 40, 557 (2000)], numerous branches of closely spaced unstable eigenmodes exist. These modes are difficult and time-consuming to adequately resolve with the existing linear initial-value solvers, which are further limited to the most unstable eigenmode. The new method is based on an eigenvalue approach and is an extension of the GYRO code [J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 (2003)], reusing the existing discretization schemes in both real and velocity-space. Unlike recent methods, which use an iterative solver to compute eigenvalues of the relatively large gyrokinetic response matrix, the present scheme computes the zeros of the much smaller Maxwell dispersion matrix using a direct method. In the present work, the new eigensolver is applied to gyrokinetic stability analysis of a high-beta, NSTX-like plasma. We illustrate the smooth transformation from ion-temperature-gradient (ITG)-like to kinetic-ballooning (KBM)-like modes, and the formation of hybrid ITG/KBM modes, and further demonstrate the existence of high-k Alfvnic drift-wave "cascades" for which the most unstable mode is a higher excited state along the field line. A new compressional electron drift wave, which is driven by a combination of strong beta and pressure gradient, is also identified for the first time. Overall, we find that accurate calculation of stability boundaries and growth rates cannot, in general, ignore the compressional component ?B? of the perturbation.

Belli, E. A.; Candy, J.

2010-11-01

71

Fully electromagnetic gyrokinetic eigenmode analysis of high-beta shaped plasmas  

SciTech Connect

A new, more efficient method to compute unstable linear gyrokinetic eigenvalues and eigenvectors has been developed for drift-wave analysis of plasmas with arbitrary flux-surface shape, including both transverse and compressional magnetic perturbations. In high-beta, strongly shaped plasmas like in the National Spherical Torus Experiment (NSTX) [M. Ono et al., Nucl. Fusion 40, 557 (2000)], numerous branches of closely spaced unstable eigenmodes exist. These modes are difficult and time-consuming to adequately resolve with the existing linear initial-value solvers, which are further limited to the most unstable eigenmode. The new method is based on an eigenvalue approach and is an extension of the GYRO code [J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 (2003)], reusing the existing discretization schemes in both real and velocity-space. Unlike recent methods, which use an iterative solver to compute eigenvalues of the relatively large gyrokinetic response matrix, the present scheme computes the zeros of the much smaller Maxwell dispersion matrix using a direct method. In the present work, the new eigensolver is applied to gyrokinetic stability analysis of a high-beta, NSTX-like plasma. We illustrate the smooth transformation from ion-temperature-gradient (ITG)-like to kinetic-ballooning (KBM)-like modes, and the formation of hybrid ITG/KBM modes, and further demonstrate the existence of high-k Alfvenic drift-wave 'cascades' for which the most unstable mode is a higher excited state along the field line. A new compressional electron drift wave, which is driven by a combination of strong beta and pressure gradient, is also identified for the first time. Overall, we find that accurate calculation of stability boundaries and growth rates cannot, in general, ignore the compressional component {delta}B{sub ||} of the perturbation.

Belli, E. A.; Candy, J. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States)

2010-11-15

72

High-Energy Space Propulsion Based on Magnetized Target Fusion  

NASA Technical Reports Server (NTRS)

A conceptual study is made to explore the feasibility of applying magnetized target fusion (MTF) to space propulsion for omniplanetary travel. Plasma-jet driven MTF not only is highly amenable to space propulsion, but also has a number of very attractive features for this application: 1) The pulsed fusion scheme provides in situ a very dense hydrogenous liner capable of moderating the neutrons, converting more than 97% of the neutron energy into charged particle energy of the fusion plasma available for propulsion. 2) The fusion yield per pulse can be maintained at an attractively low level (< 1 GJ) despite a respectable gain in excess of 70. A compact, low-weight engine is the result. An engine with a jet power of 25 GW, a thrust of 66 kN, and a specific impulse of 77,000 s, can be achieved with an overall engine mass of about 41 metric tons, with a specific power density of 605 kW/kg, and a specific thrust density of 1.6 N/kg. The engine is rep-rated at 40 Hz to provide this power and thrust level. At a practical rep-rate limit of 200 Hz, the engine can deliver 128 GW jet power and 340 kN of thrust, at specific power and thrust density of 1,141 kW/kg and 3 N/kg respectively. 3) It is possible to operate the magnetic nozzle as a magnetic flux compression generator in this scheme, while attaining a high nozzle efficiency of 80% in converting the spherically radial momentum of the fusion plasma to an axial impulse. 4) A small fraction of the electrical energy generated from the flux compression is used directly to recharge the capacitor bank and other energy storage equipment, without the use of a highvoltage DC power supply. A separate electrical generator is not necessary. 5) Due to the simplicity of the electrical circuit and the components, involving mainly inductors, capacitors, and plasma guns, which are connected directly to each other without any intermediate equipment, a high rep-rate (with a maximum of 200 Hz) appears practicable. 6) All fusion related components are within the current state of the art for pulsed power technology. Experimental facilities with the required pulsed power capabilities already exist. 7) The scheme does not require prefabricated fuel target and liner hardware in any esoteric form or state. All necessary fuel and liner material are introduced into the engine in the form of ordinary matter in gaseous state at room temperature, greatly simplifying their handling on board. They are delivered into the fusion reaction chamber in a completely standoff manner.

Thio, Y. C. F.; Freeze, B.; Kirkpatrick, R. C.; Landrum, B.; Gerrish, H.; Schmidt, G. R.

1999-01-01

73

Fusion  

NASA Astrophysics Data System (ADS)

The book abounds with fascinating anecdotes about fusion's rocky path: the spurious claim by Argentine dictator Juan Peron in 1951 that his country had built a working fusion reactor, the rush by the United States to drop secrecy and publicize its fusion work as a propaganda offensive after the Russian success with Sputnik; the fortune Penthouse magazine publisher Bob Guccione sank into an unconventional fusion device, the skepticism that met an assertion by two University of Utah chemists in 1989 that they had created "cold fusion" in a bottle. Aimed at a general audience, the book describes the scientific basis of controlled fusion--the fusing of atomic nuclei, under conditions hotter than the sun, to release energy. Using personal recollections of scientists involved, it traces the history of this little-known international race that began during the Cold War in secret laboratories in the United States, Great Britain and the Soviet Union, and evolved into an astonishingly open collaboration between East and West.

Herman, Robin

1990-10-01

74

A high temperature fusion reactor design  

Microsoft Academic Search

A conceptual design of a blanket for a 7 m tokamak reactor is discussed, one that is capable of producing 1100 C process heat at a pressure of about 10 atmospheres. The design is based on the use of a falling bed of MgO spheres as the high-temperature heat-transfer system. The tritium breeding is accomplished using Li2O modules both in

S. D. Harkness; J. F. Depaz; M. Y. Gohar; H. C. Stevens

1979-01-01

75

Production of high intensity Beta beams at the ISOLDE facility  

NASA Astrophysics Data System (ADS)

We discuss a design study devoted to a construction of the Beta beams facility at CERN, a next generation European facility aiming for a production of pure and collimated ultra-relativistic beam of electron (anti)neutrinos with help of accelerated ?-decaying radioactive ions circulating in a storage decay ring. This high intense source of (anti)neutrinos directed towards a remote underground neutrino detector will allow to measure neutrino oscillations with high accuracy offering a unique chance for establishing a value of the ?13 mixing angle and CP violating phase. Recently, a significant progress have been achieved on the conceptual design of high power targets required for a production and an extraction of two baseline isotopes, 6He and 18Ne, at the unexampled rate of several 1013 ions/s. There is a possibility to produce these isotopes using the so-called Isotope Separation On Line (ISOL) method at the ISOLDE facility (CERN). The 6He production is realized by taking advantage of the 9Be(n,?)6He reaction and with help of spallation neutrons and porous BeO target material. The production of 18Ne through the 19F(p,2n)18Ne reaction at required intensities is even more challenging. Currently, a molten salt (NaF) loop target is proposed for a production of high rate of 18Ne required for the Beta beams project. The progress on the design study associated with new data and plans for future is briefly presented.

Hodk, Rastislav; Stora, Thierry; Mendona, Tania M.

2011-12-01

76

An improved fusion of IHS based on wavelet for high resolution images  

NASA Astrophysics Data System (ADS)

In recent years, Multi-sources data fusion techniques have already been an International research hotspot in Remote Sensing. To date, many image fusion techniques have been developed. However, the available algorithms can hardly produce a satisfactory fusion result for high resolution images. Among the existing fusion algorithms, the IHS technique is the most widely used one, and the wavelet fusion is the most frequently discussed one in recent publications because of its advantages over other fusion techniques. But the shortcome of colour distortion and low resolution in many field is often obvious, especially when QuickBird natural colour multispectral images are fused with its panchromatic images. In this paper, an improved fusion of IHS based on wavelet is proposed. At the same time ,From the result of this experiment proves that the concept of the proposed improved fusion is promising, and it does significantly improve the fusion quality compared to conventional IHS and wavelet transform fusion techniques.

Feng, Yi; Wu, Beiping; Yue, Yingchun

2010-08-01

77

Blanket options for high-efficiency fusion power  

SciTech Connect

The efficiencies of blankets for fusion reactors are usually in the range of 30 to 40%, limited by the operating temperatures (500/sup 0/C) of conventional structural materials such as stainless steels. In this project two-zone blankets are proposed; these blankets consist of a low-temperature shell surrounding a high-temperature interior zone. A survey of nucleonics and thermal hydraulic parameters has led to a reference blanket design consisting of a water-cooled stainless steel shell around a BeO, ZrO/sub 2/ interior (cooled by argon) utilizing Li/sub 2/O for tritium breeding. In this design, approximately 60% of the fusion energy is deposited in the high-temperature interior. The maximum argon temperature is 2230/sup 0/C leading to an overall efficiency estimate of 55 to 60% for this reference case.

Usher, J L; Lazareth, O W; Fillo, J A; Horn, F L; Powell, J R

1980-01-01

78

The SCEPTRE high-temperature reactor concept for inertial fusion  

Microsoft Academic Search

The goal of the SCEPTRE project was to create an advanced second-generation inertial fusion reactor that offers the potential for either generating electricity at 50% efficiency, providing high temperature heat (850°C) for hydrogen production, or producing fissile fuel for light-water reactors. The authors have found that these applications are conceptually feasible with a reactor that is intrinsically free of the

M. J. Monsler; W. R. Meier

1983-01-01

79

Secret high-temperature reactor concept for inertial fusion  

Microsoft Academic Search

The goal of our SCEPTRE project was to create an advanced second-generation inertial fusion reactor that offers the potential for either of the following: (1) generating electricity at 50% efficiency, (2) providing high temperature heat (850°C) for hydrogen production, or (3) producing fissile fuel for light-water reactors. We have found that these applications are conceptually feasible with a reactor that

M. J. Monsler; W. R. Meier

1983-01-01

80

Applications of high-speed dust injection to magnetic fusion  

SciTech Connect

It is now an established fact that a significant amount of dust is produced in magnetic fusion devices due to plasma-wall interactions. Dust inventory must be controlled, in particular for the next-generation steady-state fusion machines like ITER, as it can pose significant safety hazards and degrade performance. Safety concerns are due to tritium retention, dust radioactivity, toxicity, and flammability. Performance concerns include high-Z impurities carried by dust to the fusion core that can reduce plasma temperature and may even induce sudden termination of the plasma. We have recognized that dust transport, dust-plasma interactions in magnetic fusion devices can be effectively studied experimentally by injection of dust with known properties into fusion plasmas. Other applications of injected dust include diagnosis of fusion plasmas and edge localized mode (ELM)'s pacing. In diagnostic applications, dust can be regarded as a source of transient neutrals before complete ionization. ELM's pacing is a promising scheme to prevent disruptions and type I ELM's that can cause catastrophic damage to fusion machines. Different implementation schemes are available depending on applications of dust injection. One of the simplest dust injection schemes is through gravitational acceleration of dust in vacuum. Experiments at Los Alamos and Princeton will be described, both of which use piezoelectric shakers to deliver dust to plasma. In Princeton experiments, spherical particles (40 micron) have been dropped in a systematic and reproducible manner using a computer-controlled piezoelectric bending actuator operating at an acoustic (0,2) resonance. The circular actuator was constructed with a 2.5 mm diameter central hole. At resonance ({approx} 2 kHz) an applied sinusoidal voltage has been used to control the flux of particles exiting the hole. A simple screw throttle located {approx}1mm above the hole has been used to set the magnitude of the flux achieved for a given voltage. Particle fluxes ranging from a few tens of particle per second up to thousands of particles per second have been achieved using this simple device. To achieve higher dust injection speed, another key consideration is how to accelerate dust at controlled amount. In addition to gravity, other possible acceleration mechanisms include electrostatic, electromagnetic, gas-dragged, plasma-dragged, and laser-ablation-based acceleration. Features and limitations of the different acceleration methods will be discussed. We will also describe laboratory experiments on dust acceleration.

Wang, Zhehui [Los Alamos National Laboratory; Li, Yangfang [Max Planck Institute for Extraterrestrial Physics, Germany

2012-08-08

81

High-Energy Space Propulsion Based on Magnetized Target Fusion  

NASA Technical Reports Server (NTRS)

Magnetized target fusion is an approach in which a magnetized target plasma is compressed inertially by an imploding material wall. A high energy plasma liner may be used to produce the required implosion. The plasma liner is formed by the merging of a number of high momentum plasma jets converging towards the center of a sphere where two compact toroids have been introduced. Preliminary 3-D hydrodynamics modeling results using the SPHINX code of Los Alamos National Laboratory have been very encouraging and confirm earlier theoretical expectations. The concept appears ready for experimental exploration and plans for doing so are being pursued. In this talk, we explore conceptually how this innovative fusion approach could be packaged for space propulsion for interplanetary travel. We discuss the generally generic components of a baseline propulsion concept including the fusion engine, high velocity plasma accelerators, generators of compact toroids using conical theta pinches, magnetic nozzle, neutron absorption blanket, tritium reprocessing system, shock absorber, magnetohydrodynamic generator, capacitor pulsed power system, thermal management system, and micrometeorite shields.

Thio, Y. C. F.; Landrum, D. B.; Freeze, B.; Kirkpatrick, R. C.; Gerrish, H.; Schmidt, G. R.

1999-01-01

82

High temperature plasma in beta Lyrae, observed from Copernicus  

NASA Technical Reports Server (NTRS)

High-resolution UV spectrophotometry of the complex close binary system beta Lyrae was performed with a telescope spectrometer on board Copernicus. Observations were made at phases 0.0, 0.25, 0.5, and 0.75 with resolutions of 0.2 A (far-UV) and 0.4 A (mid-UV). The far-UV spectrum is completely dominated by emission lines indicating the existence of a high-temperature plasma in this binary. The spectrum of this object is unlike that of any other object observed from Copernicus. It is believed that this high-temperature plasma results from dynamic mass transfer taking place in the binary. The current results are compared with OAO-2 observations and other observational results. The possibility that the secondary component is a collapsed object is also discussed; the Copernicus observations are consistent with the hypothesis that the spectroscopically invisible secondary component is a black hole.

Kondo, Y.; Hack, M.; Hutchings, J. B.; Mccluskey, G. E., Jr.; Plavec, M.; Polidan, R. S.

1975-01-01

83

Fusion reactor high vacuum pumping: Charcoal cryosorber tritium exposure results  

SciTech Connect

Recent experiments, have shown the practically of using activated charcoal (coconut charcoal) at 4{degrees}K to pump helium and hydrogen isotopes for a fusion reactor. Both speed and capacity for deuterium/helium and tritium/helium-3 mixtures were shown to be satisfactory. The long term effects of tritium on the charcoal/cement system developed by Grumman and LLNL were not known and a program was undertaken to see what, if any, effect long term tritium exposure has on the cryosorber. Several charcoal on aluminum test samples were subjected to six months exposure of tritium at approximately 77{degrees}K. The tritium was scanned several times with a residual gas analyzer and the speed-capacity performance of the samples was measured before, approximately half way through and after the exposure. Modest effects were noted which would not seriously restrict charcoal's use as a cryosorber for fusion reactor high vacuum pumping applications. 4 refs., 8 figs.

Sedgley, D.W.; Walthers, C.R.; Jenkins, E.M. (Grumman Aerospace Corp., Bethpage, NY (United States))

1991-01-01

84

High Frequency of Fusion Transcripts Involving TCF7L2 in Colorectal Cancer: Novel Fusion Partner and Splice Variants  

PubMed Central

VTI1A-TCF7L2 was reported as a recurrent fusion gene in colorectal cancer (CRC), found to be expressed in three out of 97 primary cancers, and one cell line, NCI-H508, where a genomic deletion joins the two genes [1]. To investigate this fusion further, we analyzed high-throughput DNA and RNA sequencing data from seven CRC cell lines, and identified the gene RP11-57H14.3 (ENSG00000225292) as a novel fusion partner for TCF7L2. The fusion was discovered from both genome and transcriptome data in the HCT116 cell line. By triplicate nested RT-PCR, we tested both the novel fusion transcript and VTI1A-TCF7L2 for expression in a series of 106 CRC tissues, 21 CRC cell lines, 14 normal colonic mucosa, and 20 normal tissues from miscellaneous anatomical sites. Altogether, 42% and 45% of the CRC samples expressed VTI1A-TCF7L2 and TCF7L2-RP11-57H14.3 fusion transcripts, respectively. The fusion transcripts were both seen in 29% of the normal colonic mucosa samples, and in 25% and 75% of the tested normal tissues from other organs, revealing that the TCF7L2 fusion transcripts are neither specific to cancer nor to the colon and rectum. Seven different splice variants were detected for the VTI1A-TCF7L2 fusion, of which three are novel. Four different splice variants were detected for the TCF7L2-RP11-57H14.3 fusion. In conclusion, we have identified novel variants of VTI1A-TCF7L2 fusion transcripts, including a novel fusion partner gene, RP11-57H14.3, and demonstrated detectable levels in a large fraction of CRC samples, as well as in normal colonic mucosa and other tissue types. We suggest that the fusion transcripts observed in a high frequency of samples are transcription induced chimeras that are expressed at low levels in most samples. The similar fusion transcripts induced by genomic rearrangements observed in individual cancer cell lines may yet have oncogenic potential as suggested in the original study by Bass et al. PMID:24608966

Bakken, Anne Cathrine; Rognum, Torleiv O.; Nesbakken, Arild; Skotheim, Rolf I.

2014-01-01

85

High-performance inertial confinement fusion target implosions on OMEGA  

SciTech Connect

The Omega Laser Facility is used to study inertial confinement fusion (ICF) concepts. This paper describes progress in direct-drive central hot-spot (CHS) ICF, shock ignition (SI) and fast ignition (FI) since the 2008 IAEA FEC conference. CHS cryogenic deuterium-tritium (DT) target implosions on OMEGA have produced the highest DT areal densities yet measured in ICF implosions (~300 mg cm{sup -2}). Integrated FI experiments have shown a significant increase in neutron yield caused by an appropriately timed high-intensity, high-energy laser pulse.

Meyerhofer, D. D.; McCrory, R L; Betti, R; Boehly, T R; Casey, D T; Collins, T.J.B.; Craxton, R S; Delettrez, J A; Edgell, D H; Epstein, R; Fletcher, K A; Frenje, J A; Glebov, Y Yu; Goncharov, V N; Harding, D R; Hu, S X; Igumenshchev, I V; Knauer, J P; Li, C K; Marozas, J A; Marshall, F J; McKenty, P W; Nilson, P M; Padalino, S P; Petrasso, R D; Radha, P B; Regan, S P; Sangster, T C; Seguin, F H; Seka, W; Short, R W; Shvarts, D; Skupsky, S; Soures, J M; Stoeckl, C; Theobald, W; Yaakobi, B

2011-04-18

86

High Current Ion Sources and Injectors for Heavy Ion Fusion  

SciTech Connect

Heavy ion beam driven inertial fusion requires short ion beam pulses with high current and high brightness. Depending on the beam current and the number of beams in the driver system, the injector can use a large diameter surface ionization source or merge an array of small beamlets from a plasma source. In this paper, we review the scaling laws that govern the injector design and the various ion source options including the contact ionizer, the aluminosilicate source, the multicusp plasma source, and the MEVVA source.

Kwan, Joe W.

2005-02-15

87

Inertial Confinement Fusion Ignition and High Yield Campaign The Inertial Confinement Fusion Ignition and High Yield (ICF) Campaign supports the U.S. Department of Energy's (DOE)  

E-print Network

Inertial Confinement Fusion Ignition and High Yield Campaign Overview The Inertial Confinement Fusion Ignition and High Yield (ICF) Campaign supports the U.S. Department of Energy's (DOE) national power facilities for both ignition and weapon relevant non-ignition HED research and advanced simulation

88

Beta-Coupled High-Frequency Activity and Beta-Locked Neuronal Spiking in the Subthalamic Nucleus of Parkinson's Disease  

PubMed Central

Beta frequency (1330 Hz) oscillatory activity in the subthalamic nucleus (STN) of Parkinson's disease (PD) has been shown to influence the temporal dynamics of high-frequency oscillations (HFOs; 200500 Hz) and single neurons, potentially compromising the functional flexibility of the motor circuit. We examined these interactions by simultaneously recording both local field potential and single-unit activity from the basal ganglia of 15 patients with PD during deep brain stimulation (DBS) surgery of the bilateral STN. Phase-amplitude coupling (PAC) in the STN was specific to beta phase and HFO amplitude, and this coupling was strongest at the dorsal STN border. We found higher beta-HFO PAC near DBS lead contacts that were clinically effective compared with the remaining non-effective contacts, indicating that PAC may be predictive of response to STN DBS. Neuronal spiking was locked to the phase of 830 Hz oscillations, and the spatial topography of spike-phase locking (SPL) was similar to that of PAC. Comparisons of PAC and SPL showed a lack of spatiotemporal correlations. Beta-coupled HFOs and field-locked neurons had different preferred phase angles and did not co-occur within the same cycle of the modulating oscillation. Our findings provide additional support that beta-HFO PAC may be central to the pathophysiology of PD and suggest that field-locked neurons alone are not sufficient for the emergence of beta-coupled HFOs. PMID:25232117

Yang, Andrew I.; Vanegas, Nora; Lungu, Codrin

2014-01-01

89

Development in DIII-D of High Beta Discharges Appropriate for Steady-state Tokamak Operation With Burning Plasmas  

SciTech Connect

Ideally, tokamak power plants will operate in steady-state at high fusion gain. Recent work at DIII-D on the development of suitable high beta discharges with 100% of the plasma current generated noninductively (f{sub NI} = 1) is described. In a discharge with 1.5 < q{sub min} <2, a scan of the discharge shape squareness was used to find the value that maximizes confinement and achievable {beta}{sub N}. A small bias of the up/down balance of the double-null divertor shape away from the ion B x {del}B drift direction optimizes pumping for minimum density. Electron cyclotron current drive with a broad deposition profile was found to be effective at avoidance of a 2/1 NTM allowing long duration at {beta}{sub N} = 3.7. With these improvements, surface voltage {approx} 0-10 mV, indicating f{sub NI} {approx} 1, was obtained for 0.7 {tau}{sub R} (resistive time). Stationary discharges with {beta}{sub N} = 3.4 and f{sub NI} {approx} 0.9 that project to Q = 5 in ITER have been demonstrated for {tau}{sub R}. For use in development of model based controllers for the q profile, transport code models of the current profile evolution during discharge formation have been validated against the experiment. Tests of available actuators confirm that electron heating during the plasma current ramp up to modify the conductivity is by far the most effective. The empirically designed controller has been improved by use of proportional/integral gain and built-in limits to {beta}{sub N} to avoid instabilities. Two alternate steady-state compatible scenarios predicted to be capable of reaching {beta}{sub N} = 5 have been tested experimentally, motivated by future machines that require high power density and neutron fluence. In a wall stabilized scenario with q{sub min} > 2, {beta}{sub N} = 4 has been achieved for 2 s {approx} {tau}{sub R}. In a high internal inductance scenario, which maximizes the ideal no-wall stability limit, {beta}{sub N} {approx} 4.8 has been reached with f{sub NI} > 1.

Ferron, J R; Basiuk, V; Casper, T A; Challis, C D; DeBoo, J C; Doyle, E J; Gao, Q; Garofalo, A M; Greenfield, C M; Holcomb, C T; Hyatt, A W; Ide, S; Luce, T C; Murakami, M; Ou, Y; Park, J; Petrie, T W; Petty, C C; Politzer, P A; Reimerdes, H; Schuster, E; Schneider, M; Wang, A

2008-10-13

90

Garden-hose instability in high-beta plasmas  

NASA Astrophysics Data System (ADS)

This paper reviews the theory of classical garden-hose instability in high-beta plasmas. The garden-hose (or fire-hose) instability is a hydromagnetic instability that is due to the nonresonant wave-particle interaction. Therefore, to the lowest order, it is customary to describe the instability under the assumption of hydromagnetic perturbation. The hydromagnetic assumption implies that the characteristic wave frequency (or the growth rate) is much lower than the ion gyrofrequency, and that the ion gyroradius is sufficiently smaller than the characteristic wavelength associated with the perturbation. As a result, the ion gyroradius is often taken to be zero at the outset. However, it was recently discovered that keeping the ion gyroradius finite (however small it may be) results in a fundamental alteration of the basic property of the instability. The article also reviews the nonlinear theory of the garden-hose instability.

Yoon, Peter H.

1995-01-01

91

Ignitor and the High Density Approach for Fusion*  

NASA Astrophysics Data System (ADS)

The high plasma density regimes discovered by high magnetic field toroidal experiments have both outstanding confinement characteristics and degree of purity, and are at the basis of the Ignitor design. The main purpose of the Ignitor experiment is, in fact, that of establishing the reactor physics in regimes close to ignition, where the thermonuclear instability can set in with all its associated non linear effects. ``Extended limiter'' and double X-point configurations have been analyzed and relevant transport simulations show that similar burning plasma conditions can be attained with both, by Ohmic heating only or with modest amounts of ICRH auxiliary heating. The driving factor for the machine design (R01.32 m, a xb0.47x0.83 m^2, BT<=13 T, Ip<=11 MA) is the poloidal field pressure that can contain, under macroscopically stable conditions, the peak plasma pressures corresponding to ignition. Objectives other than ignition can be envisioned for the relatively near term, for example that of high flux neutron sources for material testing involving compact, high density fusion machines. This has been one of the incentives that have led the Ignitor Project to adopt magnesium diboride (MgB2) superconducting cables in the machine design, a first in fusion research. Accordingly, the largest coils (about 5 m diameter) of the machine will be made entirely of MgB2 cables. *Sponsored in part by ENEA of Italy and by the U.S. D.O.E.

Bombarda, F.; Coppi, B.

2010-11-01

92

High expression of beta2-glycoprotein I is associated significantly with the earliest stages of hepatitis B virus infection.  

PubMed

Human beta2-glycoprotein I (beta2-GPI) binds to recombinant hepatitis B surface antigen (rHBsAg) and can bind specifically to annexin II, which is located on the cell membrane of human hepatoma SMMC-7721 cells. Viral envelope proteins are essential for mediating cellular entry. The aim of this study was to investigate the role of beta2-GPI in the early stages of hepatitis B virus (HBV) infection. Western blot and qRT-PCR analyses revealed that beta2-GPI expression was upregulated in HepG2.2.15 cells at both the mRNA and protein level and was almost non-existent in 293T and CHO cells. Furthermore, annexin II was expressed at lower levels in HepG2.2.15 cells compared to L02, HepG2, and SMMC-7721 cells. Additionally, ELISA analyses demonstrated that beta2-GPI enhanced the ability of HBsAg to bind to cell surfaces, and there was differential adhesion to L02, HepG2, HepG2.2.15, and 293T cells. Western blot and ELISA were then performed to assess the effects of HBV and the HBsAg domain on beta2-GPI expression in co-transfected 293T cells. This study revealed that HBV and the large HBV envelope protein increased beta2-GPI expression. Further investigation indicated that beta2-GPI colocalized with HBsAg in the cytosol of HepG2.2.15 cells, with sodium taurocholate co-transporting polypeptide (NTCP) on the cell membrane in NTCP-complemented HepG2 cells, and with annexin II in the cytosol of HepG2 and HepG2.2.15 cells. These data suggest that high expression of beta2-GPI enhances HBsAg binding to cell surfaces, thus contributing to virus particle transfer to the NTCP receptor and interaction with annexin II for viral membrane fusion. PMID:24760738

Liu, Ya-Ming; Zhang, Wen-Yan; Wang, Zhong-Feng; Yan, Chao-Ying; Gao, Pu-Jun

2014-08-01

93

Access to high beta advanced inductive plasmas at low injected torque  

NASA Astrophysics Data System (ADS)

Recent experiments on DIII-D demonstrate that advanced inductive (AI) discharges with high equivalent normalized fusion gain can be accessed and sustained with very low amounts (?1 N m) of externally injected torque, a level of torque that is anticipated to drive a similar amount of rotation as the beams on ITER, via simple consideration of the scaling of the moment of inertia and confinement time. The AI regime is typically characterized by high confinement, and high ?N, allowing the possibility for high performance, high gain operation at reduced plasma current. Discharges achieved ?N ? 3.1 with H98(y,2) ? 1 at q95 ? 4, and are sustained for the maximum duration of the counter neutral beams (NBs). In addition, plasmas using zero net NB torque from the startup all the way through to the high ?N phase have been created. AI discharges are found to become increasingly susceptible to m/n = 2/1 neoclassical tearing modes as the torque is decreased, which if left unmitigated, generally slow and lock, terminating the high performance phase of the discharge. Access is not notably different whether one ramps the torque down at high ?N, or ramps ?N up at low torque. The use of electron cyclotron heating (ECH) and current drive proved to be an effective method of avoiding such modes, enabling stable operation at high beta and low torque, a portion of phase space that has otherwise been inaccessible. Thermal confinement is significantly reduced at low rotation, a result that is reproduced using the TGLF transport model. Although it is thought that stiffness is increased in regions of low magnetic shear, in these AI plasmas, the reduced confinement occurs at radii outside the low shear, and in fact, higher temperature gradients can be found in the low shear region at low rotation. Momentum transport is also larger at low rotation, but a significant intrinsic torque is measured that is consistent with a previous scaling considering the role of the turbulent Reynolds stress and thermal ion orbit loss. Although high normalized fusion performance has been achieved in these discharges, more detailed projections suggest that enhancement in the confinement needs to be realized in order to obtain a low current solution consistent with ITER Q = 10 performance, and this remains a future research challenge.

Solomon, W. M.; Politzer, P. A.; Buttery, R. J.; Holcomb, C. T.; Ferron, J. R.; Garofalo, A. M.; Grierson, B. A.; Hanson, J. M.; In, Y.; Jackson, G. L.; Kinsey, J. E.; La Haye, R. J.; Lanctot, M. J.; Luce, T. C.; Okabayashi, M.; Petty, C. C.; Turco, F.; Welander, A. S.

2013-09-01

94

High-{beta}, improved confinement reversed-field pinch plasmas at high density  

SciTech Connect

In Madison Symmetric Torus [Dexter et al., Fusion Technol. 19, 131 (1991)] discharges where improved confinement is brought about by modification of the current profile, pellet injection has quadrupled the density, reaching n{sub e}=4x10{sup 19} m{sup -3}. Without pellet injection, the achievable density in improved confinement discharges had been limited by edge-resonant tearing instability. With pellet injection, the total beta has been increased to 26%, and the energy confinement time is comparable to that at low density. Pressure-driven local interchange and global tearing are predicted to be linearly unstable. Interchange has not yet been observed experimentally, but there is possible evidence of pressure-driven tearing, an instability usually driven by the current gradient in the reversed-field pinch.

Wyman, M. D.; Chapman, B. E.; Ahn, J. W.; Almagri, A. F.; Anderson, J. K.; Den Hartog, D. J.; Ebrahimi, F.; Ennis, D. A.; Fiksel, G.; Gangadhara, S.; Goetz, J. A.; O'Connell, R.; Oliva, S. P.; Prager, S. C.; Reusch, J. A.; Sarff, J. S.; Stephens, H. D. [Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Bonomo, F.; Franz, P. [Consorzio RFX, Corso Stati Uniti 4, 35127 Padova (Italy); Brower, D. L. [Department of Physics and Astronomy, University of California at Los Angeles, Los Angeles, California 90095-1594 (United States)] (and others)

2008-01-15

95

High-Beta, Improved Confinement Reversed-Field Pinch Plasmas at High Density  

SciTech Connect

In Madison Symmetric Torus Dexter et al., Fusion Technol. 19, 131 1991 discharges where improved confinement is brought about by modification of the current profile, pellet injection has quadrupled the density, reaching ne=41019 m 3. Without pellet injection, the achievable density in improved confinement discharges had been limited by edge-resonant tearing instability. With pellet injection, the total beta has been increased to 26%, and the energy confinement time is comparable to that at low density. Pressure-driven local interchange and global tearing are predicted to be linearly unstable. Interchange has not yet been observed experimentally, but there is possible evidence of pressure-driven tearing, an instability usually driven by the current gradient in the reversed-field pinch.

Wyman, M. [University of Wisconsin, Madison; Chapman, B. E. [University of Wisconsin, Madison; Ahn, J. W. [University of Wisconsin, Madison; Almagri, A. [University of Wisconsin, Madison; Anderson, J. [University of Wisconsin, Madison; Bonomo, F. [Consorzio RFX, Italy; Brower, D. L. [University of California, Los Angeles; Combs, Stephen Kirk [ORNL; Craig, D. [University of Wisconsin, Madison; Hartog, D. J. Den [University of Wisconsin, Madison; Deng, B. [University of California, Los Angeles; Ding, W. X. [University of California, Los Angeles; Ebrahimi, F. [University of Wisconsin, Madison; Ennis, D. [University of Wisconsin, Madison; Fiksel, G. [University of Wisconsin, Madison; Foust, Charles R [ORNL; Franz, P. [EURATOM / ENEA, Italy; Gangadhara, S. [University of Wisconsin, Madison; Goetz, J. [University of Wisconsin, Madison; O'Connell, R, [University of Wisconsin, Madison; Oliva, S. [University of Wisconsin, Madison; Prager, S. C. [University of Wisconsin, Madison; Reusch, J. A. [University of Wisconsin, Madison; Sarff, J. S. [University of Wisconsin, Madison; Stephens, H. D. [University of Wisconsin, Madison; Yates, T. [University of California, Los Angeles

2008-01-01

96

Electromagnetic effects on dynamics of high-beta filamentary structures  

NASA Astrophysics Data System (ADS)

The impacts of the electromagnetic effects on blob dynamics are considered. Electromagnetic BOUT++ simulations on seeded high-beta blobs demonstrate that inhomogeneity of magnetic curvature or plasma pressure along the filament leads to bending of the blob filaments and the magnetic field lines due to increased propagation time of plasma current (Alfvn time). The bending motion can enhance heat exchange between the plasma facing materials and the inner scrape-off layer (SOL) region. The effects of sheath boundary conditions on the part of the blob away from the boundary are also diminished by the increased Alfvn time. Using linear analysis and BOUT++ simulations, it is found that electromagnetic effects in high temperature and high density plasmas reduce the growth rate of resistive drift wave instability when resistivity drops below a certain value. The blobs temperature decreases in the course of its motion through the SOL and so the blob can switch from the electromagnetic to the electrostatic regime where resistive drift waves become important again.

Lee, Wonjae; Umansky, Maxim V.; Angus, J. R.; Krasheninnikov, Sergei I.

2015-01-01

97

SMALL SCALE FUSION THE PULSED HIGH DENSITY FRC EXPERIMENT  

Microsoft Academic Search

It is quite possible that nuclear fusion will be the only source that can provide the prodigious power demands that the world will face in the future. The difficulty however for most nuclear fusion concepts is the complexity and large mass associated with the confinement systems. Essentially, the more massive the system required to confine and heat the fusion plasma,

John Slough

98

Towards high resolution optical imaging of beta cells in vivo.  

PubMed

Endocrine beta cells produce and release insulin in order to tightly regulate glucose homeostasis and prevent metabolic pathologies such as Diabetes Mellitus. Optical imaging has contributed greatly to our current understanding of beta cell structure and function. In vitro microscopy of beta cell lines has revealed the localization of molecular components in the cell and more recently their dynamic behavior. In cultured islets, interactions of beta cells with other islet cells and the matrix as well as paracrine and autocrine signaling or reaction to nutrients have been studied. Lastly, microscopy has been performed on tissue sections, visualizing the islets in an environment closer to their natural surroundings. In most efforts to date, the samples have been isolated for investigation and hence have by definition been divorced from their natural environments and deprived of vascularization and innervations. In such a setting the beta cells lack the metabolic information that is primordial to their basic function of maintaining glucose homeostasis. We review optical microscopy; its general principles, its impact in decoding beta cell function and its recent developments towards the more physiologically relevant assessment of beta cell function within the environment of the whole organism. This requires both large imaging depth and fast acquisition times. Only few methods can achieve an adequate compromise. We present extended focus Optical Coherence Microscopy (xfOCM) as a valuable alternative to both confocal microscopy and two photon microscopy (2PM), and discuss its potential in interpreting the mechanisms underlying glucose homeostasis and monitoring impaired islet function. PMID:20146662

Villiger, M; Goulley, J; Martin-Williams, E J; Grapin-Botton, A; Lasser, T

2010-05-01

99

Fusion materials high energy-neutron studies. A status report  

SciTech Connect

The objectives of this paper are (1) to provide background information on the US Magnetic Fusion Reactor Materials Program, (2) to provide a framework for evaluating nuclear data needs associated with high energy neutron irradiations, and (3) to show the current status of relevant high energy neutron studies. Since the last symposium, the greatest strides in cross section development have been taken in those areas providing FMIT design data, e.g., source description, shielding, and activation. In addition, many dosimetry cross sections have been tentatively extrapolated to 40 MeV and integral testing begun. Extensive total helium measurements have been made in a variety of neutron spectra. Additional calculations are needed to assist in determining energy dependent cross sections.

Doran, D.G.; Guinan, M.W.

1980-01-01

100

Achievement of high fusion triple product, steady-state sustainment and real-time NTM stabilization in high-betap ELMy H-mode discharges in JT-60U  

Microsoft Academic Search

This paper reports results on the progress in steady-state high-bgrp ELMy H-mode discharges in JT-60U. A fusion triple product, nD(0)tgrETi(0), of 3.1 1020 m-3 s keV under full non-inductive current drive has been achieved at Ip = 1.8 MA, which extends the record value of the fusion triple product under full non-inductive current drive by 50%. A high-beta plasma

A. Isayama; Y. Kamada; N. Hayashi; T. Suzuki; T. Oikawa; T. Fujita; T. Fukuda; S. Ide; H. Takenaga; K. Ushigusa; T. Ozeki; Y. Ikeda; N. Umeda; H. Yamada; M. Isobe; Y. Narushima; K. Ikeda; S. Sakakibara; K. Yamazaki; K. Nagasaki

2003-01-01

101

An analytic solution of high. beta. equilibrium in a large aspect ratio tokamak  

SciTech Connect

An analytic solution of the high {beta} ({epsilon}{bar {beta}}{sub p} {approximately} {beta}q{sup 2}/{epsilon} {much gt} 1) equilibrium of a large aspect ratio tokamak is presented. Two arbitrary flux functions, the pressure profile p({psi}) and the safety factor profile q({psi}), specify the equilibrium. The solution splits into two asymptotic regions: the core region where {psi} is a function of the major radius alone and a narrow boundary layer region adjoining the conducting wall. The solutions in the two regions are asymptotically matched to each other. For monotonic pressure profiles, the Shafranov shift is equal to the minor radius. For {beta} much bigger than one, the solution contains a region (in place of the magnetic axis) of zero magnetic field and constant pressure. At high {beta} the quantity {beta}{sub I}, which is essentially proportional to the pressure over the total current squared, is largely independent of pressure. We discuss the important ramifications of limited {beta}{sub I} for high {beta} reactors. Generalizations to shaped cross sections and hollow pressure profiles are outlined. We also consider the problem of equilibrium reconstruction in the high {beta} regime. 8 refs., 7 figs.

Cowley, S.C.; Kaw, P.K.; Kelly, R.S.; Kulsrud, R.M.

1991-03-01

102

Cyclisation of citronellal over zirconium zeolite beta a highly diastereoselective catalyst to ()-isopulegol  

Microsoft Academic Search

The catalytic cyclisation of citronellal was studied over Zr-zeolite beta, micro\\/mesoporous Al-MSU-SFAU, and microporous HY catalysts. All samples showed good activity in the cyclisation of citronellal to form isopulegols with >97% selectivity. A high diastereoselectivity for ()-isopulegol of ?93% was observed over Zr-zeolite beta, whereas Al-MSU-SFAU and HY showed a lower selectivity of ?65%. Zr-zeolite beta was synthesised in a

Zhu Yongzhong; Nie Yuntong; Stephan Jaenicke; Gaik-Khuan Chuah

2005-01-01

103

Internal hydrogen embrittlement of high-strength beta-alpha titanium alloys  

Microsoft Academic Search

Potential problems and uncertainties are associated with the complex nature of fracture in solution treated and aged (STA) beta-titanium (beta-Ti) alloys, as well as the potential for long-term alloy degradation due to hydrogen embrittlement. This research characterizes the effects of predissolved hydrogen and microstructural conditions on the fracture resistance of two solution treated and aged (STA) high strength beta-titanium alloys,

Sean Paul Hayes

2000-01-01

104

High-beta operation and magnetohydrodynamic activity on the TFTR tokamak  

SciTech Connect

Magnetohydrodynamic (MHD) activity within three zones (core, half-radius, and edge) of TFTR ({ital Plasma} {ital Physics} {ital and} {ital Controlled} {ital Nuclear} {ital Fusion} {ital Research} 1986 (IAEA, Vienna, 1987), Vol. 1, p. 51) tokamak plasmas are discussed. Near the core of the plasma column, sawteeth are often observed. Two types of sawteeth are studied in detail; one with complete, and the other with incomplete, magnetic reconnection. Their characteristics are determined by the shape of the {ital q} profile. Near the half-radius the {ital m}/{ital n}=3/2 and 2/1 resistive ballooning modes are found to correlate with a beta collapse. The pressure and the pressure gradient at the mode rational surface are found to play an important role in stability. MHD activity is also studied at the plasma edge during limiter H modes. The edge localized modes (ELM's) are found to have a precursor mode with a frequency between 50--200 kHz and a mode number {ital m}/{ital n}=1/0. The mode does not show a ballooning structure. While these instabilities have been studied on many other machines, on TFTR the studies have been extended to high pressure (plasma pressure greater than 4{times}10{sup 5} Pa) and low collisionality ({ital v}{sup {ital i}}{sub *}({ital a}/2){lt}0.002, {ital v}{sup {ital e}}{sub *}({ital a}/2){lt}0.01).

McGuire, K.; Arunasalam, V.; Barnes, C.W.; Bell, M.G.; Bitter, M.; Boivin, R.; Bretz, N.L.; Budny, R.; Bush, C.E.; Cavallo, A.; Chu, T.K.; Cohen, S.A.; Colestock, P.; Davis, S.L.; Dimock, D.L.; Dylla, H.F.; Efthimion, P.C.; Ehrhrardt, A.B.; Fonck, R.J.; Fredrickson, E.; Furth, H.P.; Gammel, G.; Goldston, R.J.; Greene, G.; Grek, B.; Grisham, L.R.; Hammett, G.; Hawryluk, R.J.; Hendel, H.W.; Hill, K.W.; Hinnov, E.; Hoffman, D.J.; Hosea, J.; Howell, R.B.; Hsuan, H.; Hulse, R.A.; Janos, A.C.; Jassby, D.; Jobes, F.; Johnson, D.W.; Johnson, L.C.; Kaita, R.; Kieras-Phillips, C.; Kilpatrick, S.J.; LaMarche, P.H.; LeBlanc, B.; Manos, D.M.; Mansfield, D.K.; Mazzucato, E.; McCarthy, M.P.; McCune, M.C.; McNeill, D.H.; Meade, D.M.; Medley, S.S.; Mikkelsen, D.R.; Monticello, D.; Motley, R.; Mueller, D.; Murphy, J.A.; Nagayama, Y.; Nazakian, D.R.; Neischmidt, E.B.; Owens, D.K.; Park, H.; Park, W.; Pitcher, S.; Ramsey, A.T.; Redi, M.H.; Roquemore, A.L.; Rutherford, P.H.; Schilling, G.; Schivell, J.; Sc

1990-06-01

105

MHD analysis of high (. beta. /sub t/) disruptions in PBX (Princeton Beta Experiment)  

SciTech Connect

PBX discharges run at the lowest q and highest (..beta../sub t/) always terminated in a hard disruption. The discharges, with (..beta../sub t/) values of up to 5.5% and q-values down to 2.2, were obtained by employing large current ramps and large gas feed rates during neutral beam injection. Previous work has indicated that the achieved (..beta../sub t/)-values were consistent with the limit imposed by the n = 1 ideal external kink with a conducting wall at b/a = 2. In this work, we investigate further the validity of ideal MHD theory in explaining the low-q/sub psi/j disruptions. In particular, the character of the pre-disruption MHD activity in these low-q discharges, specifically the time scales of growth and internal and external mode structures, was compared with those determined from theoretical calculations. The results of these comparisons indicate that non-ideal effects must be considered to obtain detailed agreement between theory and experiment. 13 refs., 6 figs.

Jahns, G.L.; Chance, M.S.; Kaye, S.M.; Manickam, J.; Takahashi, H.; LeBlanc, B.; Morris, A.W.; Reusch, M.; Sesnic, S.

1987-10-01

106

INSTITUTE OF PHYSICS PUBLISHING and INTERNATIONAL ATOMIC ENERGY AGENCY NUCLEAR FUSION Nucl. Fusion 44 (2004) 10151026 PII: S0029-5515(04)83150-8  

E-print Network

INSTITUTE OF PHYSICS PUBLISHING and INTERNATIONAL ATOMIC ENERGY AGENCY NUCLEAR FUSION Nucl. Fusion fusion since they are compact, have high beta, and require no toroidal field [1]. They can be formed geometries are considered. In one case the beam is injected through the ends, at a small angle to the FRC

Washington at Seattle, University of

107

Irradiation uniformity for high-compression laser-fusion experiments  

SciTech Connect

High-compression direct-drive laser-fusion experiments require the rms laser-irradiation nonuniformity to be below the 1{percent}{endash}2{percent} level. The combination of two-dimensional smoothing by spectral dispersion (SSD), phase plates, polarization smoothing, and beam overlap are shown to be sufficient to reach this goal. Here is presented a discussion of the mathematical formalism of two-dimensional SSD with numerical calculations illustrating the factors that affect irradiation uniformity. The levels of uniformity that can be achieved on the OMEGA laser [T. R. Boehly {ital et al.}, Opt. Commun. {bold 133}, 495 (1997)] at the University of Rochester and at the National Ignition Facility (NIF) [Paisner {ital et al.}, Laser Focus World {bold 30}, 75 (1994)] being built at the Lawrence Livermore National Laboratory are examined.

Skupsky, S.; Craxton, R.S. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States)] [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States)

1999-05-01

108

Physics basis for the Fusion Ignition Research Experiment (FIRE)  

SciTech Connect

Understanding the properties of high gain (alpha-dominated) fusion plasmas in an advanced toroidal configuration is a critical issue that must be addressed to provide the scientific foundation for an attractive magnetic fusion reactor. The functional fusion plasma objectives for major next physics steps in magnetic fusion research can be described as: Burning Plasma Physics - The achievement and understanding of alpha-dominated plasmas that have characteristics similar to those expected in a fusion energy source, and Advanced Toroidal Physics - The achievement and understanding of bootstrap-current-dominated plasmas with externally controlled profiles and other characteristics (e.g. confinement and beta) similar to those expected in an attractive fusion system.

D. M. Meade; R. J. Thome; N. R. Sauthoff; P. J. Heitzenroeder; B. E. Nelson; M.A Ulrickson; C. E. Kessel; J. H. Schultz; P. H. Rutherford; J. C. Wesley; K. M. Young; W. M. Nevins; N. A. Uckan; J. A. Schmidt

2000-07-07

109

Identification of Tcf4 residues involved in high-affinity beta-catenin binding.  

PubMed

The N-termini of members of the T-cell factor (Tcf) and lymphocyte-enhancement factor (Lef) protein families bind to beta-catenin, forming bipartite transcription factors which regulate expression of genes involved in organismal development and the growth of normal and malignant colon epithelium. Elevated levels of Tcf4:beta-catenin are found in colon tumor cells with mutations in the adenomatous polyposis coli (APC) gene. The elevated levels of Tcf4:beta-catenin result in increased transcription of genes, including c-myc, important for the growth of these tumor cells. Here we analyze the interaction between beta-catenin and Tcf4 and show that the N-terminal 53 amino acids of Tcf4 bind with high affinity to beta-catenin. We show that this high-affinity interaction involves multiple contact points including Tcf4 Asp-16, which is essential for beta-catenin binding. In addition to Tcf/Lef family members, beta-catenin binds to APC and cadherins. We found that the binding of beta-catenin to Tcf4, APC, or E-cadherin was mutually exclusive. These results are discussed with regard to how beta-catenin interacts with its binding partners and to the potential for identifying specific, small molecule inhibitors of these interactions. PMID:10080941

Omer, C A; Miller, P J; Diehl, R E; Kral, A M

1999-03-24

110

Whole Organism High Content Screening Identifies Stimulators of Pancreatic Beta-Cell Proliferation  

PubMed Central

Inducing beta-cell mass expansion in diabetic patients with the aim to restore glucose homeostasis is a promising therapeutic strategy. Although several in vitro studies have been carried out to identify modulators of beta-cell mass expansion, restoring endogenous beta-cell mass in vivo has yet to be achieved. To identify potential stimulators of beta-cell replication in vivo, we established transgenic zebrafish lines that monitor and allow the quantification of cell proliferation by using the fluorescent ubiquitylation-based cell cycle indicator (FUCCI) technology. Using these new reagents, we performed an unbiased chemical screen, and identified 20 small molecules that markedly increased beta-cell proliferation in vivo. Importantly, these structurally distinct molecules, which include clinically-approved drugs, modulate three specific signaling pathways: serotonin, retinoic acid and glucocorticoids, showing the high sensitivity and robustness of our screen. Notably, two drug classes, retinoic acid and glucocorticoids, also promoted beta-cell regeneration after beta-cell ablation. Thus, this study establishes a proof of principle for a high-throughput small molecule-screen for beta-cell proliferation in vivo, and identified compounds that stimulate beta-cell proliferation and regeneration. PMID:25117518

Delawary, Mina; Osman, Sahar; Roh, Alex S.; Gut, Philipp; Stainier, Didier Y. R.

2014-01-01

111

Development and application of nonflammable, high-temperature beta fibers  

NASA Technical Reports Server (NTRS)

Recent advances in fiber technology have contributed to the success of the U.S. space program. The inorganic fiber Beta, developed as a result of efforts begun in the early 1960's and heightened following the January 27, 1967 Apollo fire is unique among inorganic and organic fibers. It has been developed into woven, nonwoven, knitted, braided, coated and printed structures. All of these were used extensively for the Apollo, Skylab, Apollo-Soyuz test project, space shuttle, Spacelab, and satellite programs. In addition to being used successfully in the space program, Beta fibers are being used commercially as firesafe fabrics in homes, hospitals, institutions, public buildings, aircraft, and public transportation, wherever total nonflammability is required. One of the most unique applications of the Beta composite structure is the roofing material for the 80,000-seat Detroit Lion's Silverdome and 5 square miles of the Jeddah International Airport in Saudi Arabia. This fiber has been successfully incorporated into 165 major public construction projects around the globe. The United States alone has used more than 12 million square yards of the material. Beta fiber has been used successfully to date and has a promising future with unlimited potential for both space and commercial application. Efforts are currently underway to improve Beta fiber to meet the requirements of extended service life for the Space Station Freedom, lunar outpost, and Mars exploration missions.

Dawn, Frederic S.

1989-01-01

112

Engineering design and control scenario for steady-state high-beta operation in National Centralized Tokamak  

Microsoft Academic Search

The mission of the National Centralized Tokamak (NCT) is to establish high-beta steady-state plasma operation for DEMO and to contribute to ITER. Plasma performance with high-beta conditions is discussed. It is found that near break-even class plasma (QDTeq?0.7) with high beta (?N?3.5) is achievable with 25MW of NB power at IP=4.0MA and an aspect ratio of 2.6. High beta with

K. Tsuchiya; M. Akiba; H. Azechi; T. Fujii; T. Fujita; M. Fujiwara; K. Hamamatsu; H. Hashizume; N. Hayashi; H. Horiike; N. Hosogane; M. Ichimura; K. Ida; Y. Ikeda; T. Imai; N. Inoue; S. Ishida; S. Itoh; Y. Kamada; H. Kawashima; M. Kikuchi; A. Kimura; K. Kizu; H. Kubo; Y. Kudo; K. Kurihara; G. Kurita; M. Kuriyama; K. Masaki; M. Matsukawa; M. Matsuoka; Y. Miura; N. Miya; A. Morioka; K. Nakamura; H. Ninomiya; A. Nishimura; K. Okano; K. Okuno; A. Sagara; M. Sakamoto; S. Sakurai; K. Sato; R. Shimada; A. Shimizu; T. Suzuki; H. Takahashi; Y. Takase; M. Takechi; H. Tamai; S. Tanaka; H. Tsutsui; Y. Uesugi; K. Yatsu; N. Yoshida

2006-01-01

113

The convergence of analytic high-{beta} equilibrium in a finite aspect ratio tokamak  

SciTech Connect

The characteristics of near-unity-{beta} equilibria are investigated with two codes. CUBE is a multigrid Grad-Shafranov solver [Gourdain et al., J. Comput. Phys. 216, 275 (2006)], and Ophidian was written to compute solutions using analytic unity-{beta} equilibria [Cowley et al., Phys. Fluids B 3, 2066 (1991)]. Results from each method are qualitatively and quantitatively compared across a spectrum of mutually relevant parameters. These comparisons corroborate the theoretical results and provide benchmarks for high-resolution numerical results available from CUBE. Both tools facilitate the exploration of the properties of high-{beta} equilibria, such as a highly diamagnetic plasma and its ramifications for stability and transport.

Neches, R. Y.; Cowley, S. C.; Gourdain, P. A.; Leboeuf, J. N. [Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, California 90095 (United States)

2008-12-15

114

The high current transport experiment for heavy ion inertial fusion  

SciTech Connect

The High Current Experiment (HCX) at Lawrence Berkeley National Laboratory is part of the US program to explore heavy-ion beam transport at a scale representative of the low-energy end of an induction linac driver for fusion energy production. The primary mission of this experiment is to investigate aperture fill factors acceptable for the transport of space-charge-dominated heavy-ion beams at high space-charge intensity (line charge density {approx} 0.2 {micro}C/m) over long pulse durations (>4 ms) in alternating gradient electrostatic and magnetic quadrupoles. This experiment is testing--at driver-relevant scale--transport issues resulting from nonlinear space-charge effects and collective modes, beam centroid alignment and beam steering, matching, image charges, halo, electron cloud effects, and longitudinal bunch control. We present the results for a coasting 1 MeV K{sup +} ion beam transported through the first ten electrostatic transport quadrupoles, measured with beam-imaging and phase-space diagnostics. The latest additions to the experiment include measurements of the secondary ion, electron and atom coefficients due to halo ions scraping the wall, and four magnetic quadrupoles to explore similar issues in magnetic channels.

Seidl, P.A.; Baca, D.; Bieniosek, F.M.; Celata, C.M.; Faltens, A.; Prost, L.R.; Sabbi, G.; Waldron, W.L.; Cohen, R.; Friedman, A.; Lund, S.M.; Molvik, A.W.; Haber, I.

2003-05-01

115

Viral Fusion Peptides Induce Several Signal Transduction Pathway Activations That Are Essential for Interleukin10 and Beta-Interferon Production  

Microsoft Academic Search

Objectives: The deciphering of intracellular signaling pathways that are activated by the interaction between viral fusion peptides and cellular membranes are important for the understanding of both viral replication strategies and host defense mechanisms. Methods: Fusion peptides of several enveloped viruses belonging to different virus families were prepared by standard 9-fluorenylmethoxycarbonyl polyamine solid-phase synthesis and used to stimulate U937 cells

Mariateresa Vitiello; Emiliana Finamore; Annarita Falanga; Katia Raieta; Marco Cantisani; Francesco Galdiero; Carlo Pedone; Marilena Galdiero; Stefania Galdiero

2010-01-01

116

High current transport experiment for heavy ion inertial fusion  

NASA Astrophysics Data System (ADS)

The High Current Experiment at Lawrence Berkeley National Laboratory is part of the U.S. program to explore heavy-ion beam transport at a scale representative of the low-energy end of an induction linac driver for fusion energy production. The primary mission of this experiment is to investigate aperture fill factors acceptable for the transport of space-charge-dominated heavy-ion beams at high intensity (line charge density 0.2 ?C/m) over long pulse durations (4 ?s) in alternating gradient focusing lattices of electrostatic or magnetic quadrupoles. This experiment is testing transport issues resulting from nonlinear space-charge effects and collective modes, beam centroid alignment and steering, envelope matching, image charges and focusing field nonlinearities, halo, and electron and gas cloud effects. We present the results for a coasting 1 MeV K+ ion beam transported through ten electrostatic quadrupoles. The measurements cover two different fill factor studies (60% and 80% of the clear aperture radius) for which the transverse phase space of the beam was characterized in detail, along with beam energy measurements and the first halo measurements. Electrostatic quadrupole transport at high beam fill factor (?80%) is achieved with acceptable emittance growth and beam loss, even though the initial beam distribution is not ideal (but the emittance is low) nor in thermal equilibrium. We achieved good envelope control, and rematching may only be needed every ten lattice periods (at 80% fill factor) in a longer lattice of similar design. We also show that understanding and controlling the time dependence of the envelope parameters is critical to achieving high fill factors, notably because of the injector and matching section dynamics.

Prost, L. R.; Seidl, P. A.; Bieniosek, F. M.; Celata, C. M.; Faltens, A.; Baca, D.; Henestroza, E.; Kwan, J. W.; Leitner, M.; Waldron, W. L.; Cohen, R.; Friedman, A.; Grote, D.; Lund, S. M.; Molvik, A. W.; Morse, E.

2005-02-01

117

The high current transport experiment for heavy ion inertial fusion  

SciTech Connect

The High Current Experiment (HCX) at Lawrence Berkeley National Laboratory is part of the US program to explore heavy-ion beam transport at a scale representative of the low-energy end of an induction linac driver for fusion energy production. The primary mission of this experiment is to investigate aperture fill factors acceptable for the transport of space-charge-dominated heavy-ion beams at high intensity (line charge density {approx} 0.2 {micro}C/m) over long pulse durations (4 {micro}s) in alternating gradient focusing lattices of electrostatic or magnetic quadrupoles. This experiment is testing transport issues resulting from nonlinear space-charge effects and collective modes, beam centroid alignment and steering, envelope matching, image charges and focusing field nonlinearities, halo and, electron and gas cloud effects. We present the results for a coasting 1 MeV K{sup +} ion beam transported through ten electrostatic quadrupoles. The measurements cover two different fill factor studies (60% and 80% of the clear aperture radius) for which the transverse phase-space of the beam was characterized in detail, along with beam energy measurements and the first halo measurements. Electrostatic quadrupole transport at high beam fill factor ({approx}80%) is achieved with acceptable emittance growth and beam loss, even though the initial beam distribution is not ideal (but the emittance is low) nor in thermal equilibrium. We achieved good envelope control, and rematching may only be needed every ten lattice periods (at 80% fill factor) in a longer lattice of similar design. We also show that understanding and controlling the time dependence of the envelope parameters is critical to achieving high fill factors, notably because of the injector and matching section dynamics.

Prost, L.R.; Baca, D.; Bieniosek, F.M.; Celata, C.M.; Faltens, A.; Henestroza, E.; Kwan, J.W.; Leitner, M.; Seidl, P.A.; Waldron, W.L.; Cohen, R.; Friedman, A.; Grote, D.; Lund, S.M.; Molvik, A.W.; Morse, E.

2004-05-01

118

Hydrogen pump using a high-temperature proton conductor for nuclear fusion engineering applications  

Microsoft Academic Search

In a nuclear fusion plant, the development of hydrogen processing technologies is an important issue since hydrogen isotope gas must be utilized as fuel. High-temperature proton conductors are favorable materials for hydrogen processing systems in nuclear fusion engineering. Possible applications of proton conductors include hydrogen pumps and hydrogen sensing. For one of these protonic functions, we have proposed applying a

M. Tanaka; K. Katahira; Y. Asakura; T. Ohshima

2010-01-01

119

The First Clinical Trial of Beta-Calcium Pyrophosphate as a Novel Bone Graft Extender in Instrumented Posterolateral Lumbar Fusion  

PubMed Central

Background Porous ?-calcium pyrophosphate (?-CPP) was developed to improve the fusion success of posterolateral lumbar fusion (PLF). The possibility of accomplishing PLF using a mixture of porous ?-CPP and iliac bone was studied. This paper reports the radiologic results of PLF using the ?-CPP plus autograft for lumbar degenerative disease as a bone graft extender. Methods A prospective, case-matched, radiographic study evaluating the results of short segment lumbar fusion using a ?-CPP plus autograft was performed to compare the efficacy of ?-CPP plus autograft with that of an autograft alone for short segment lumbar fusion. Thirty one consecutive patients (46 levels) underwent posterolateral fusion with pedicle screw fixation and additional posterior lumbar interbody fusion. In all patients, 3 mL of ?-CPP plus 3 mL of autogenous bone graft was placed randomly in one side of a posterolateral gutter, and 6 mL of autogenous iliac bone graft was placed on the other. The fusion rates, volumes of fusion masses, and bone absorption percentage were evaluated postoperatively using simple radiographs and 3 dimensional computed tomography (3D-CT) scans. Results The control sides treated with an autograft showed significantly better Lenke scores than the study sides treated with ?-CPP at 3 and 6 months postoperatively, but there was no difference between the two sides at 12 months. The fusion rates (confirmed by 3D-CT) were 87.0% in the ?-CPP group and 89.1% in the autograft group, which were not significantly different. The fusion mass volumes and bone absorption percentage at 12 months postoperatively were 2.49 mL (58.4%) and 1.89 mL (69.5%) for the ?-CPP and autograft groups, respectively, and mean fusion mass volume was significantly higher in the ?-CPP group. Conclusions ?-CPP combined with an autograft is as effective as autologous bone for grafting during instrumented posterolateral spinal fusion. These findings suggest that ?-CPP bone chips can be used as a novel bone graft extender for short-segment posterolateral spinal fusion. PMID:21909472

Lee, Jae Hyup; Jeung, Ul-Oh; Park, Kun-Woo; Kim, Min-Seok; Lee, Choon-Ki

2011-01-01

120

Alfvn Acoustic Channel for Ion Energy in High-Beta Tokamak Plasmas  

NASA Astrophysics Data System (ADS)

When the plasma beta (ratio of thermal to magnetic pressure) in the core of a tokamak is raised to values of several percent, as required for a thermonuclear fusion reactor, continuous spectra of long-wavelength slow magnetosonic waves enter the frequency band occupied by continuous spectra of shear Alfvn waves. It is found that these two branches can couple strongly, so that Alfvn modes that are resonantly driven by suprathermal ions transfer some of their energy to sound waves. Since sound waves are heavily damped by thermal ion Landau resonances, these results reveal a new energy channel that contributes to the damping of Alfvnic instabilities and the noncollisional heating of bulk ions, with potentially important consequences for confinement and fusion performance.

Bierwage, Andreas; Aiba, Nobuyuki; Shinohara, Kouji

2015-01-01

121

Alfvn acoustic channel for ion energy in high-beta tokamak plasmas.  

PubMed

When the plasma beta (ratio of thermal to magnetic pressure) in the core of a tokamak is raised to values of several percent, as required for a thermonuclear fusion reactor, continuous spectra of long-wavelength slow magnetosonic waves enter the frequency band occupied by continuous spectra of shear Alfvn waves. It is found that these two branches can couple strongly, so that Alfvn modes that are resonantly driven by suprathermal ions transfer some of their energy to sound waves. Since sound waves are heavily damped by thermal ion Landau resonances, these results reveal a new energy channel that contributes to the damping of Alfvnic instabilities and the noncollisional heating of bulk ions, with potentially important consequences for confinement and fusion performance. PMID:25615474

Bierwage, Andreas; Aiba, Nobuyuki; Shinohara, Kouji

2015-01-01

122

RF behavior of triple-frequency high power fusion gyrotron  

NASA Astrophysics Data System (ADS)

The RF behavior of high power, triple frequency (170-, 127.5-, and 85 GHz) gyrotron for fusion application is presented in this paper. The operating mode selection is discussed in detail for each corresponding frequencies and TE34,10, TE25,8 and TE17,5 modes are selected as the operating mode for 170 GHz, 127.5 GHz and 85 GHz operation of the device, respectively. The interaction cavity geometry and beam parameters are finalized by the cold cavity analysis and beam-wave interaction simulations. Considering the beam parameters and the beam launching positions in cavity (beam radius), the design of Magnetically Tunable MIG (MT-MIG) is also presented. Results of MT-MIG confirm the beam launching with desired beam parameters at the beam radius corresponding to the selected operating modes for all three frequencies. The CVD diamond window is also designed for RF power transmission. The beam-wave interaction simulations confirm more than 1 MW power at all three frequencies (170-, 127.5-, and 85 GHz).

Kumar, Nitin; Singh, Udaybir; Kumar, Anil; Sinha, A. K.

2014-05-01

123

Neutralinos in Vector Boson Fusion at High Energy Colliders  

E-print Network

Discovering dark matter at high energy colliders continues to be a compelling and well-motivated possibility. Weakly interacting massive particles are a particularly interesting class in which the dark matter particles interact with the standard model weak gauge bosons. Neutralinos are a prototypical example that arise in supersymmetric models. In the limit where all other superpartners are decoupled, it is known that for relic density motivated masses, the rates for neutralinos are too small to be discovered at the Large Hadron Collider (LHC), but that they may be large enough for a 100 TeV collider to observe. In this work we perform a careful study in the vector boson fusion channel for pure winos and pure higgsinos. We find that given a systematic uncertainty of 1% (5%), with 3000 fb$^{-1}$, the LHC is sensitive to winos of 240 GeV (125 GeV) and higgsinos of 125 GeV (55 GeV). A future 100 TeV collider would be sensitive to winos of 1.1 TeV (750 GeV) and higgsinos of 530 GeV (180 GeV) with a 1% (5%) uncertainty, also with 3000 fb$^{-1}$.

Asher Berlin; Tongyan Lin; Matthew Low; Lian-Tao Wang

2015-02-17

124

High-$\\gamma$ Beta Beams within the LAGUNA design study  

E-print Network

Within the LAGUNA design study, seven candidate sites are being assessed for their feasibility to host a next-generation, very large neutrino observatory. Such a detector will be expected to feature within a future European accelerator neutrino programme (Superbeam or Beta Beam), and hence the distance from CERN is of critical importance. In this article, the focus is a $^{18}$Ne and $^{6}$He Beta Beam sourced at CERN and directed towards a 50 kton Liquid Argon detector located at the LAGUNA sites: Slanic (L=1570 km) and Pyh\\"{a}salmi (L=2300 km). To improve sensitivity to the neutrino mass ordering, these baselines are then combined with a concurrent run with the same flux directed towards a large Water \\v{C}erenkov detector located at Canfranc (L=650 km). This degeneracy breaking combination is shown to provide comparable physics reach to the conservative Magic Baseline Beta Beam proposals. For $^{18}$Ne ions boosted to $\\gamma=570$ and $^{6}$He ions boosted to $\\gamma=350$, the correct mass ordering can be...

Orme, Christopher

2010-01-01

125

High-$?$ Beta Beams within the LAGUNA design study  

E-print Network

Within the LAGUNA design study, seven candidate sites are being assessed for their feasibility to host a next-generation, very large neutrino observatory. Such a detector will be expected to feature within a future European accelerator neutrino programme (Superbeam or Beta Beam), and hence the distance from CERN is of critical importance. In this article, the focus is a $^{18}$Ne and $^{6}$He Beta Beam sourced at CERN and directed towards a 50 kton Liquid Argon detector located at the LAGUNA sites: Slanic (L=1570 km) and Pyh\\"{a}salmi (L=2300 km). To improve sensitivity to the neutrino mass ordering, these baselines are then combined with a concurrent run with the same flux directed towards a large Water \\v{C}erenkov detector located at Canfranc (L=650 km). This degeneracy breaking combination is shown to provide comparable physics reach to the conservative Magic Baseline Beta Beam proposals. For $^{18}$Ne ions boosted to $\\gamma=570$ and $^{6}$He ions boosted to $\\gamma=350$, the correct mass ordering can be determined at Slanic for all $\\delta$ when $\\sin^{2}2\\theta_{13}>4\\cdot 10^{-3}$ in this combination.

Christopher Orme

2010-04-06

126

Comparison of electron capture and beta decay rates in high temperature environment in explosion of supernova type II  

NASA Astrophysics Data System (ADS)

It is generally acknowledged that Type II supernova results from the collapse of iron core of a massive star which, at least in some cases, produces a neutron star. At this stage, the neutrinos are produced by neutronization which speeds up as collapse continues. During collapse an outward bound shock wave forms in the matter falling onto the nearly stationary core. The conditions behind the shock at 100 to 200 km are suitable for neutrino heating. This neutrino heating blows a hot bubble above the protoneutron star and is the most important source of energy for Supernova explosion. At this stage, we try to attain the r-process (rapid neutron capture process) path responsible for the production of heavy elements beyond iron, which are otherwise not possible to be formed by fusion reactions. The most interesting evolution occurs as temperature falls from 1010 K to 109 K. At these high temperature conditions, the near critical fluids after fusion reactions transform into the respective atoms by r-process path which on beta decaying produce the ultimate elements of the periodic chart. Another astrophysical parameter needed for our analysis is neutron number density which we take to be greater than 1020 cm^{-3}. With these, at different entropy environments, we assign the neutron binding energy that represents the r-process path in the chart of nuclides. Along the path, the experimental data of observed elements matches our calculated one. It is found that the dynamical timescale of the final collapse is dominated by electron capture on nuclei and not on free protons. It is also found that the beta decay rates are much higher than the corresponding electron capture rates at the same classical condition.

Baruah, Rulee

127

High-Level Fusion Physics and Materials Interface Challenges July 27, 2012  

E-print Network

High-Level Fusion Physics and Materials Interface Challenges July 27, 2012 and material-plasma interface challenges. These research areas can be addressed that tritium supply, inventory, breeding, recovery, safety and leakage are critical

128

Yellow maize with high beta-carotene is an effective source of vitamin A in healthy Zimbabwean men  

Technology Transfer Automated Retrieval System (TEKTRAN)

The bioconversion efficiency of yellow maize beta-carotene to retinol in humans is unknown. Thus, the objective of this study was to determine the vitamin A value of yellow maize beta-carotene in humans. A high beta-carotene containing yellow maize was grown in a hydroponic medium with 23 atom% 2H2O...

129

Yellow maize with high (beta)-carotene is an effective source of vitamin A in healthy Zimbabwean men  

Technology Transfer Automated Retrieval System (TEKTRAN)

BACKGROUND: The bioconversion efficiency of yellow maize Beta-carotene to retinol in humans is unknown. OBJECTIVE: The objective of this study was to determine the vitamin A value of yellow maize Beta-carotene in humans. DESIGN: High Beta-carotene-containing yellow maize was grown in a hydroponic...

130

MICRO-HETEROGENEITY AND MICRO-RHEOLOGICAL PROPERTIES OF HIGH-VISCOSITY OAT BETA-GLUCAN SOLUTIONS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soluble fiber beta-glucan is one of the key dietary materials in the healthy food products known for reducing serum cholesterol levels. However, the physical properties of beta-glucan are rarely known. In this work, the micro-structural heterogeneity and micro-rheology of high-viscosity oat beta-g...

131

Spatial and Temporal Data Fusion for Generating High-Resolution Land Cover Imagery  

NASA Astrophysics Data System (ADS)

Currently, remote sensing imagery has been widely used for generating global land cover products, but due to certain physical and budget limitations related to the sensors, their spatial and temporal resolution are too low to attain more accurate and more reliable global change research. In this situation, there is an urgent need to study and develop a more advanced satellite image processing method and land cover producing techniques to generate higher resolution images and land cover products for global change research. Through conducting a comprehensive study of the related theories and methods related to data fusion, various methods are systematically reviewed and summarized, such as HIS transformation image fusion, Wavelet transform image fusion, the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM), etc. The advantages and disadvantages of these methods are highlighted according to their specific applications in the field of remote sensing. Based on my research target, the following are the main contents of this thesis: (1) Data fusion theory will be systematically studied and summarized, including various fusion models and specific applications, such as IHS transformation, PCA transformation, Wavelet analysis based data fusion, etc. Furthermore, their advantages and disadvantages are pointed out in relation to specific applications. (2) As traditional data fusion methods rely on spatial information and it is hard to deal with multi-source data fusion with temporal variation, therefore, the traditional data fusion theory and methods will be improved by a consideration of temporal information. Accordingly, some spatial and temporal data fusion methods will be proposed, in which both high-resolution & low-temporary imagery and low-resolution & high-temporary imagery are incorporated. Our experiments also show that they are suitable for dealing with multi-temporal data integration and generating high-resolution, multi-temporal images for global change research. (3) There are two main issues related to spatial and temporal data fusion theory. The first is that there are inconsistencies in different images, such as the different levels of land surface reflectance and different degrees of reliability of multi-source satellite data. The second is the rule of phonological variation/land cover variation in both the spatial and temporal dimensions, particularly in areas with heterogeneous landscapes. When considering these issues, an improved STARFM (spatial and temporal adaptive reflectance fusion model) is proposed, based on the original model, and the preliminary results show that it is more efficient and accurate in generating high-resolution land surface imagery than its predecessor. (4) Mixed pixels is a common issue in relation to satellite data processing, as one pixel in a coarse resolution image will constitute several pixels in a high-resolution image of the same size, so different levels of land surface reflectance will be acquired from multi-source satellite data because of the mixed pixel effect on the coarse resolution data, and the final accuracy of the fused result will be affected if these data are subjected to data fusion. In order to solve the mixed pixel issue in multi-source data fusion, an improved spatial and temporal data fusion approach, based on the constraint unmixing technique, was developed in this thesis. The experimental results show that it is well-suited to the phenological monitoring task when a prior land cover map is available. (5) Based on the high-resolution reflectance images generated from spatial and temporal fusion, a spatial and temporal classification method based on the spatial and temporal Markov random field was developed to produce a high-resolution land cover product, in which both spatial and temporal contextual information are included within the classification scheme. This method provides a new strategy for generating high-resolution land cover products in the area without high-resolution images at a certain time, and the experimental results show tha

Xu, Yong

132

Recent US advances in ion-beam-driven high energy density physics and heavy ion fusion  

NASA Astrophysics Data System (ADS)

During the past two years, significant experimental and theoretical progress has been made in the US heavy ion fusion science program in longitudinal beam compression, ion-beam-driven warm dense matter, beam acceleration, high brightness beam transport, and advanced theory and numerical simulations. Innovations in longitudinal compression of intense ion beams by >50 X propagating through background plasma enable initial beam target experiments in warm dense matter to begin within the next two years. We are assessing how these new techniques might apply to heavy ion fusion drivers for inertial fusion energy.

Logan, B. G.; Bieniosek, F. M.; Celata, C. M.; Coleman, J.; Greenway, W.; Henestroza, E.; Kwan, J. W.; Lee, E. P.; Leitner, M.; Roy, P. K.; Seidl, P. A.; Vay, J.-L.; Waldron, W. L.; Yu, S. S.; Barnard, J. J.; Cohen, R. H.; Friedman, A.; Grote, D. P.; Kireeff Covo, M.; Molvik, A. W.; Lund, S. M.; Meier, W. R.; Sharp, W.; Davidson, R. C.; Efthimion, P. C.; Gilson, E. P.; Grisham, L.; Kaganovich, I. D.; Qin, H.; Sefkow, A. B.; Startsev, E. A.; Welch, D.; Olson, C.

2007-07-01

133

Texture Analysis Based Fusion Experiments Using High-Resolution SAR and Optical Imagery  

NASA Astrophysics Data System (ADS)

High resolution SAR images contain plenty of detailed textural features, and optical images have spectral features. For the different characteristics of the two images, Firstly, we extracted textural measures of TerraSAR-X image based on the Gray Level Co-occurrence Matrix (GLCM) method, and chose the appropriate window. Then data fusion between textural measures of TerraSAR-X image and QuickBird multi-spectral image was implemented based on PCA transform, and the fusion results were quantitatively evaluated, showing that the fusion image keep spectral information well and the spatial information be enhanced.

Zhao, S.; Luo, Y.; Zhou, H.; Xue, Q.; Wang, A.

2012-08-01

134

IOP PUBLISHING and INTERNATIONAL ATOMIC ENERGY AGENCY NUCLEAR FUSION Nucl. Fusion 49 (2009) 055018 (13pp) doi:10.1088/0029-5515/49/5/055018  

E-print Network

IOP PUBLISHING and INTERNATIONAL ATOMIC ENERGY AGENCY NUCLEAR FUSION Nucl. Fusion 49 (2009) 055018 near classical radial confinement [3]. However, the necessity to `plug' the ends to avoid high thermal. The reactor advantages of such a linear, naturally high beta configuration would be enormous, but previous

Washington at Seattle, University of

135

Spherical torus fusion reactor  

DOEpatents

A fusion reactor is provided having a near spherical-shaped plasma with a modest central opening through which straight segments of toroidal field coils extend that carry electrical current for generating a toroidal magnet plasma confinement fields. By retaining only the indispensable components inboard of the plasma torus, principally the cooled toroidal field conductors and in some cases a vacuum containment vessel wall, the fusion reactor features an exceptionally small aspect ratio (typically about 1.5), a naturally elongated plasma cross section without extensive field shaping, requires low strength magnetic containment fields, small size and high beta. These features combine to produce a spherical torus plasma in a unique physics regime which permits compact fusion at low field and modest cost.

Peng, Yueng-Kay M. (Oak Ridge, TN)

1989-01-01

136

The Heavy Ion Fusion Science Virtual National Laboratory Recent advances in ion-beam-driven high energy density  

E-print Network

9/15/06 The Heavy Ion Fusion Science Virtual National Laboratory 1 Recent advances in ion-beam-driven high energy density physics and heavy ion fusion* *This work was performed under the auspices of the U. Presented by Ronald C. Davidson on behalf of the Heavy Ion Fusion Science Virtual National Laboratory

137

Advanced Real-Time Feedback Control in JT-60U High Performance Discharges for Application to Fusion Reactor Plasmas  

Microsoft Academic Search

The significance of real-time feedback control is emphasized in this paper as an indispensable method to improve and sustain the improved plasma characteristics in JT-60U high fusion performance discharges as well as to operate the fusion reactor under the optimal divertor conditions with respect to the heat load and exhaust pumping. In accordance, substantial improvement in the equivalent fusion amplification

T. Fukuda; T. Oikawa; S. Takeji; A. Isayama; Y. Kawano; Y. Neyatani; A. Nagashima; T. Nishitani; S. Konoshima; H. Tamai; T. Fujita; Y. Sakamoto; Y. Kamada; S. Ide; Y. Koide; H. Takenaga; K. Kurihara; S. Sakata; T. Ozeki; Y. Kawamata; Y. M. Miura

2002-01-01

138

High power ion sources for fusion plasma heating  

NASA Astrophysics Data System (ADS)

Attention is given to the construction and operation of two neutral beam injectors (NBI) which are presently operating as the primary heating sources on two plasma fusion experiments. Heating is produced by collisional interaction of the neutral beam with the target plasma. Much of the technology is similar to that employed by ion thrusters; an NBI is made by adding a downstream collisional charge-exchange neutralization cell. Operating characteristics of the sources and extraction systems are described in detail.

Lynch, D. K.; Hyman, J.; King, H. J.; Williamson, W. S.

1981-04-01

139

The Physics of Advanced High-Gain Targets for Inertial Fusion Energy  

NASA Astrophysics Data System (ADS)

In ca. 2011-2012, the National Ignition Facility is poised to demonstrate fusion ignition and gain in the laboratory for the first time. This key milestone in the development of inertial confinement fusion (ICF) can be expected to engender interest in the development of inertial fusion energy (IFE) and expanded efforts on a number of advanced targets that may achieve high fusion energy gain at lower driver energies. In this tutorial talk, we will discuss the physics underlying ICF ignition and thermonuclear burn, examine the requirements for high gain, and outline candidate R&D programs that will be required to assess the performance of these target concepts under various driver systems including lasers, heavy-ions and pulsed power. Such target concepts include those operating by fast ignition, shock ignition, impact ignition, dual-density, magnetically-insulated, one- and two-sided drive, etc., some of which may have potential to burn advanced, non-DT fusion fuels. We will then delineate the role of such targets in their application to the production of high average fusion power. Here, systems studies of IFE economics suggest that we should strive for target fusion gains of around 100 at drive energies of 1MJ, together with corresponding rep-rates of up to 10Hz and driver electrical efficiencies around 15%. In future years, there may be exciting opportunities to study such ``innovative confinement concepts'' with prospects of fielding them on facilities such as NIF to obtain high fusion energy gains on a single shot basis.

Perkins, L. John

2010-11-01

140

Nonlinear instability dynamics in a high-density, high-beta plasma  

NASA Astrophysics Data System (ADS)

Entrainment and periodic pulling of an ion acoustic instability have been observed in the power spectra of a low-pressure high-beta plasma. The observed nonlinear phenomena can be modeled by using the van der Pol equation with a forcing term. Experimental results of the nonlinear processes are presented. Ion density fluctuations are detected on a negatively biased Langmuir probe for magnetic fields and input powers above 30 G and 900 W at 7.2 MHz respectively, and gas pressure below 1.5 mTorr. This low-frequency instability is observed in the central plasma blue core (argon II emission) and can be controlled by amplitude modulation of the radio frequency input power at frequencies close to the instability frequency.

Corr, C. S.; Boswell, R. W.

2009-02-01

141

Test Chamber for Optimizing a High Pressure Xenon Neutrinoless Double Beta Decay Detector  

NASA Astrophysics Data System (ADS)

The NEXT experiment is designed to search for neutrinoless double beta decay in high pressure xenon gas; the gas is enriched with ^136Xe which is a double beta decay candidate emitter. It is currently in the research and development phase and is scheduled to be operating in Canfranc Underground Laboratory in Huesca Spain within the next 5 years. High pressure xenon gas is chosen because of its excellent energy resolution and the ability to observe tracks. Observation of the track end points will provide excellent background rejection. The design and principle of a test chamber used to optimize the detector design will be discussed.

Robert, Paul

2009-10-01

142

Microfluidic device for high-yield pairing and fusion of stem cells with somatic cells  

NASA Astrophysics Data System (ADS)

Electro cell fusion has significant potential as a biotechnology tool with applications ranging from antibody production to cellular reprogramming. However due to low fusion efficiency of the conventional electro fusion methodology the true potential of the technique has not been reached. In this paper, we report a new method which takes cell fusion efficiency two orders magnitude higher than the conventional electro fusion method. The new method, based on one-toone pairing, fusion and selection of fused cells was developed using a microfabricated device. The device was composed of two microfluidic channels, a micro slit array and a petri dish integrated with electrodes. The electrodes positioned in each channel were used to generate electric field lines concentrating in the micro slits. Cells were introduced into channels and brought in to contact through the micro slit array using dielectrophoresis. The cells in contact were fused by applying a DC pulse to electrodes. As the electric field lines were concentrated at the micro slits the membrane potential was induced only at the vicinity of the micro slits, namely only at the cell-cell contact point. This mechanism assured the minimum damage to cells in the fusion as well as the ability to control the strength and location of induced membrane potential. We introduced mouse embryonic stem cells and mouse embryonic fibroblasts to the microfluidic channels and demonstrated high-yield fusion (> 80%). Post-fusion study showed the method can generate viable hybrids of stem cells and embryonic fibroblasts. Multinucleated hybrid cells adhering on the chip surface were routinely obtained by using this method and on-chip culturing.

Gel, Murat; Hirano, Kunio; Oana, Hidehiro; Kotera, Hidetoshi; Tada, Takashi; Washizu, Masao

2011-12-01

143

The high-density Z-pinch as a pulsed fusion neutron source for fusion nuclear technology and materials testing  

SciTech Connect

The dense Z-pinch (DZP) is one of the earliest and simplest plasma heating and confinement schemes. Recent experimental advances based on plasma initiation from hair-like (10s ..mu..m in radius) solid hydrogen filaments have so far not encountered the usually devastating MHD instabilities that plagued early DZP experiments. These encouraging results along with debt of a number of proof-of principle, high-current (1--2 MA in 10--100 ns) experiments have prompted consideration of the DZP as a pulsed source of DT fusion neutrons of sufficient strength (/dot S//sub N/ greater than or equal to 10/sup 19/ n/s) to provide uncollided neutron fluxes in excess of I/sub ..omega../ = 5--10 MW/m/sup 2/ over test volumes of 10--30 litre or greater. While this neutron source would be pulsed (100s ns pulse widths, 10--100 Hz pulse rate), giving flux time compressions in the range 10/sup 5/--10/sup 6/, its simplicity, near-time feasibility, low cost, high-Q operation, and relevance to fusion systems that may provide a pulsed commercial end-product (e.g., inertial confinement or the DZP itself) together create the impetus for preliminary considerations as a neutron source for fusion nuclear technology and materials testings. The results of a preliminary parametric systems study (focusing primarily on physics issues), conceptual design, and cost versus performance analyses are presented. The DZP promises an expensive and efficient means to provide pulsed DT neutrons at an average rate in excess of 10/sup 19/ n/s, with neutron currents I/sub ..omega../ /approx lt/ 10 MW/m/sup 2/ over volumes V/sub exp/ greater than or equal to 30 litre using single-pulse technologies that differ little from those being used in present-day experiments. 34 refs., 17 figs., 6 tabs.

Krakowski, R.A.; Sethian, J.D.; Hagenson, R.L.

1989-01-01

144

The NEXT experiment: A high pressure xenon gas TPC for neutrinoless double beta decay searches  

E-print Network

Neutrinoless double beta decay is a hypothetical, very slow nuclear transition in which two neutrons undergo beta decay simultaneously and without the emission of neutrinos. The importance of this process goes beyond its intrinsic interest: an unambiguous observation would establish a Majorana nature for the neutrino and prove the violation of lepton number. NEXT is a new experiment to search for neutrinoless double beta decay using a radiopure high-pressure xenon gas TPC, filled with 100 kg of Xe enriched in Xe-136. NEXT will be the first large high-pressure gas TPC to use electroluminescence readout with SOFT (Separated, Optimized FuncTions) technology. The design consists in asymmetric TPC, with photomultipliers behind a transparent cathode and position-sensitive light pixels behind the anode. The experiment is approved to start data taking at the Laboratorio Subterr\\'aneo de Canfranc (LSC), Spain, in 2014.

Lorca, D; Monrabal, F

2012-01-01

145

The NEXT experiment: A high pressure xenon gas TPC for neutrinoless double beta decay searches  

E-print Network

Neutrinoless double beta decay is a hypothetical, very slow nuclear transition in which two neutrons undergo beta decay simultaneously and without the emission of neutrinos. The importance of this process goes beyond its intrinsic interest: an unambiguous observation would establish a Majorana nature for the neutrino and prove the violation of lepton number. NEXT is a new experiment to search for neutrinoless double beta decay using a radiopure high-pressure xenon gas TPC, filled with 100 kg of Xe enriched in Xe-136. NEXT will be the first large high-pressure gas TPC to use electroluminescence readout with SOFT (Separated, Optimized FuncTions) technology. The design consists in asymmetric TPC, with photomultipliers behind a transparent cathode and position-sensitive light pixels behind the anode. The experiment is approved to start data taking at the Laboratorio Subterr\\'aneo de Canfranc (LSC), Spain, in 2014.

D. Lorca; J. Martn-Albo; F. Monrabal; for the NEXT Collaboration

2012-10-15

146

The NEXT experiment: A high pressure xenon gas TPC for neutrinoless double beta decay searches  

NASA Astrophysics Data System (ADS)

Neutrinoless double beta decay (??0?) is a hypothetical, very slow nuclear transition in which two neutrons undergo beta decay simultaneously and without the emission of neutrinos. The importance of this process goes beyond its intrinsic interest: an unambiguous observation would establish a Majorana nature for the neutrino and prove the violation of lepton number. NEXT is a new experiment to search for neutrinoless double beta decay using a radiopure high-pressure xenon gas TPC, filled with 100 kg of Xe enriched in Xe-136. NEXT will be the first large high-pressure gas TPC to use electroluminescence readout with SOFT (Separated, Optimized FuncTions) technology. The design consists in asymmetric TPC, with photomultipliers behind a transparent cathode and position-sensitive light pixels behind the anode. The experiment is approved to start data taking at the Laboratorio Subterrneo de Canfranc (LSC), Spain, in 2014.

Lorca, D.; Martn-Albo, J.; Monrabal, F.; NEXT Collaboration

2013-08-01

147

Altered expression and function of beta1 integrins in a highly metastatic human lung adenocarcinoma cell line.  

PubMed

In order to investigate the relationship between beta1 integrins and the metastatic ability of cancer cells, we established a novel and highly metastatic cell line designated PC9-f9 from a poorly metastatic human lung adenocarcinoma cell line (PC9) in nude mice. PC9-f9 cells showed higher invasive activity in the Matrigel invasion assay than PC9 cells. Additionally, in cell adhesion assays, PC9-f9 cells adhered to laminin more strongly than PC9 cells and, unlike PC9 cells, adhered to collagen type IV and fibronectin. FACS analysis showed expression of the integrins alpha2beta1, alpha3beta1 and alpha6beta1 on both of the cell lines but alpha4beta1 and alpha5beta1 were neo-expressed on PC9-f9 cells. In cell adhesion inhibition assays, alpha3beta1 was the major laminin receptor for PC9 cells but not for PC9-f9 cells. Alternatively, PC9-f9 cells adhered to collagen type IV via alpha2beta1 and adhered to fibronectin mainly via alpha5beta1 but also moderately via alpha4beta1. The pretreatment of PC9-f9 cells with anti-beta1 monoclonal antibodies suppressed lung metastases by more than 50%. These data suggest that the altered expression and function of beta1 integrins allow PC9-f9 cells to become more adhesive and invasive, and lead to increased metastatic potential. PMID:11078804

Takenaka, K; Shibuya, M; Takeda, Y; Hibino, S; Gemma, A; Ono, Y; Kudoh, S

2000-12-01

148

Transmutation of high-level fission products and actinides in a laser-driven fusion reactor  

SciTech Connect

Incineration of [sup 90]Sr and [sup 137]Cs b thermal or fast neutrons is a very difficult problem. A 14-MeV neutron source based on intertial confinement fusion is a more appropriate choice. For the first time, the contribution of the (n,2n) reaction to incineration is revealed. The energy and nuclei balance for a system of several nuclear power plants and a fusion reactor for transmutation is analyzed. If the fusion reactor supports a sufficient number of nuclear power plants, it need not produce energy or tritium. Target and blanket material problems are considered. This paper reports that laser fusion incinerator has the best prospects because of its fast neutron spectrum and high driver efficiency by target gain product.

Basov, N.; Rozanov, V.B. (P.N. Lebedev Physical Inst., Leninsky Pr., 63, 117924 Moscow (USSR)); Belousov, N.I.; Grishunin, P.A.; Kharitonov, V.V. (Moscow Engineering Physics Inst., Kashirskoye Chausse, 31, 115409 Moscow (USSR)); Subbotin, V.I. (Obninsk Physics and Energy Inst., Obninsk (USSR))

1992-11-01

149

Inelastic diffractive production and string fusion at high energies  

SciTech Connect

The diffraction mechanism is introduced in the string fusion model. In this model, the fluctuations in the number of interacting partons go to zero as energy increases, implying that the main contribution to diffraction comes from the diffractive part of the renormalized elementary amplitude. The experimental data on total, elastic, and diffractive cross sections, in the range 20 GeV[le] [radical][ital s] [le]1.8 TeV, are reproduced for reasonable values of the parameters in the model.

Armesto, N.; Braun, M.; Pajares, C. (Departamento de Fisica de Particulas, Universidade de Santiago de Compostela, 15706 Santiago de Compostela (Spain))

1993-07-01

150

High Beta Observations of the Hot Electron Interchange Instability  

E-print Network

with coherent structures that have been detected on fast high-impedance electrostatic probes and edge Mirnov Floating potential fluctuations High impedance, 50 K-Ohm Two thoriated tungsten probes l=.99 cm, d=.16 cm, As=.3 cm2 Wide-band (.5 to 500 MHz) amplifier Floating Probes Poloidal magnetic

151

Acceleration of neon pellets to high speeds for fusion applications  

NASA Astrophysics Data System (ADS)

The injection of impurity pellets into the plasmas of tokamak fusion reactors has been proposed as a technique to lessen the deleterious effects of plasma disruptions. Equipment and techniques that were previously developed for pneumatic hydrogen pellet injection systems and used for plasma fueling applications were employed for a limited experimental study with neon pellets. Isotopic hydrogen pellets doped with neon have previously been used for injection into fusion plasmas to study impurity particle transport, and pure neon pellets are applicable for disruption studies. Using a repeating pneumatic injector in the laboratory, it was found that the formation and acceleration of 2.7-mm-diam neon pellets were relatively straightforward; reliable operation was demonstrated with both a single- and a two-stage light gas gun, including velocities of 700 m/s with a single-stage injector and up to 1740 m/s with a two-stage injector. Based on the operating sequences and successful tests demonstrated in the laboratory experiments, a three-barrel repeating pneumatic injector installed on the DIII-D tokamak was equipped with the necessary components for neon operation and has been used in initial disruption experiments with 1.8-mm-diam neon pellets.

Combs, S. K.; Love, T. L.; Jernigan, T. C.; Milora, S. L.; Frattolillo, A.; Migliori, S.

1996-03-01

152

Free Boundary, High Beta Equilibrium in a Large Aspect Ratio Tokamak with Nearly  

E-print Network

Free Boundary, High Beta Equilibrium in a Large Aspect Ratio Tokamak with Nearly Circular Plasma Boundary H. Qin A. Reiman September 25, 1996 Abstract An analytic solution is obtained for free. In the absence of surface currents at the plasma­vacuum in­ terface, the free­boundary equilibrium solution

153

Free Boundary, High Beta Equilibrium in a Large Aspect Ratio Tokamak with Nearly  

E-print Network

Free Boundary, High Beta Equilibrium in a Large Aspect Ratio Tokamak with Nearly Circular Plasma Boundary H. Qin A. Reiman September 25, 1996 Abstract An analytic solution is obtained for free. In the absence of surface currents at the plasma-vacuum in- terface, the free-boundary equilibrium solution

154

TOWARDS POSITIONAL CLONING OF THE HIGH BETA-CAROTENE OR (ORANGE) ALLELE OF CAULIFLOWER  

Technology Transfer Automated Retrieval System (TEKTRAN)

The cauliflower (Brassica oleracea L. var. botrytis) Or allele confers the accumulation of high levels of beta-carotene in various tissues that normally are devoid of carotenoids. Early work revealed that the Or gene appeared not to exert its effect via direct up-regulation of genes that encode enz...

155

Comment on enhancement of forbidden nuclear beta decay by high-intensity radio-frequency fields  

Microsoft Academic Search

A recent claim that forbidden nuclear beta decay can, by the application of a high-intensity radio-frequency field, be enhanced by many orders of magnitude is contested. The effect is shown to be nonexistent, at least within the theoretical model which has been adopted thus far.

W. Becker; R. R. Schlicher; M. O. Scully

1984-01-01

156

Tokamak disruption alarm based on a neural network model of the high- beta limit  

Microsoft Academic Search

An artificial neural network, combining signals from a large number of plasma diagnostics, was used to estimate the high- beta disruption boundary in the DIII-D tokamak. It is shown that inclusion of many diagnostic measurements results in a much more accurate prediction of the disruption boundary than that provided by the traditional Troyon limit. A trained neural network constitutes a

D. Wroblewski; G. L. Jahns; J. A. Leuer

1997-01-01

157

Falsifying High-Scale Baryogenesis with Neutrinoless Double Beta Decay and Lepton Flavor Violation  

E-print Network

Interactions that manifest themselves as lepton number violating processes at low energies in combination with sphaleron transitions typically erase any pre-existing baryon asymmetry of the universe. In this letter, we discuss the constraints obtained from an observation of neutrinoless double beta decay in this context. If a new physics mechanism of neutrinoless double beta decay is observed, typical scenarios of high-scale baryogenesis will be excluded unless the baryon asymmetry is stabilized via some new mechanism. We also sketch how this conclusion can be extended beyond the first lepton generation by incorporating lepton flavor violating processes.

Frank F. Deppisch; Julia Harz; Martin Hirsch; Wei-Chih Huang; Heinrich Ps

2015-03-16

158

Falsifying High-Scale Baryogenesis with Neutrinoless Double Beta Decay and Lepton Flavor Violation  

E-print Network

Interactions that manifest themselves as lepton number violating processes at low energies in combination with sphaleron transitions typically erase any pre-existing baryon asymmetry of the universe. In this letter, we discuss the constraints obtained from an observation of neutrinoless double beta decay in this context. If a new physics mechanism of neutrinoless double beta decay is observed, typical scenarios of high-scale baryogenesis will be excluded unless the baryon asymmetry is stabilized via some new mechanism. We also sketch how this conclusion can be extended beyond the first lepton generation by incorporating lepton flavor violating processes.

Deppisch, Frank F; Hirsch, Martin; Huang, Wei-Chih; Ps, Heinrich

2015-01-01

159

High fat programming of beta cell compensation, exhaustion, death and dysfunction.  

PubMed

Programming refers to events during critical developmental windows that shape progeny health outcomes. Fetal programming refers to the effects of intrauterine (in utero) events. Lactational programming refers to the effects of events during suckling (weaning). Developmental programming refers to the effects of events during both fetal and lactational life. Postnatal programming refers to the effects of events either from birth (lactational life) to adolescence or from weaning (end of lactation) to adolescence. Islets are most plastic during the early life course; hence programming during fetal and lactational life is most potent. High fat (HF) programming is the maintenance on a HF diet (HFD) during critical developmental life stages that alters progeny metabolism and physiology. HF programming induces variable diabetogenic phenotypes dependent on the timing and duration of the dietary insult. Maternal obesity reinforces HF programming effects in progeny. HF programming, through acute hyperglycemia, initiates beta cell compensation. However, HF programming eventually leads to chronic hyperglycemia that triggers beta cell exhaustion, death and dysfunction. In HF programming, beta cell dysfunction often co-presents with insulin resistance. Balanced, healthy nutrition during developmental windows is critical for preserving beta cell structure and function. Thus early positive nutritional interventions that coincide with the development of beta cells may reduce the overwhelming burden of diabetes and metabolic disease. PMID:25682938

Cerf, Marlon E

2015-03-01

160

High-beta plasmas in theta pinches and cusp experiments  

Microsoft Academic Search

High-? plasmasare those whose diamagnetic currents react strongly on the confining magnetic field. Examples of such plasmas, in which the field is largely excluded from the plasma, are those in linear ? pinches and cusp-compression devices. In the former, measurements show ? (the ratio of particle and magnetic pressures) to lie typically in the range 0.6 to 0.9. The sheath

F. L. Ribe

1967-01-01

161

High Temperature coatings based on {beta}-NiAI  

SciTech Connect

High temperature alloys are reviewed, focusing on current superalloys and their coatings. The synthesis, characerization, and oxidation performance of a NiAlTiB{sub 2} composite are explained. A novel coating process for MoNiAl alloys for improved oxidation performance is examined. The cyclic oxidation performance of coated and uncoated MoNiAl alloys is discussed.

Severs, Kevin

2012-07-10

162

A human beta-actin expression vector system directs high-level accumulation of antisense transcripts.  

PubMed Central

We have constructed a mammalian expression vector consisting of 3 kilobases of the human beta-actin gene 5' flanking sequence plus 5' untranslated region and intervening sequence 1 linked at the 3' splice site to a short DNA polylinker sequence containing unique Sal I, HindIII, and BamHI restriction endonuclease sites followed by a simian virus 40 (SV40) polyadenylylation signal. Two derivatives, containing the selection markers obtained from pSV2gpt or pSV2neo, were also generated. We find that the promoter activity of this vector is a great or greater than that of the SV40 early promoter in a variety of human and rodent cells. The vector was used to generate gamma-actin and beta-tubulin antisense transcripts in human fibroblast cell lines. The antisense transcripts accumulate to levels comparable with that of the highly abundant gamma-actin and beta-tubulin mRNAs. Images PMID:2440031

Gunning, P; Leavitt, J; Muscat, G; Ng, S Y; Kedes, L

1987-01-01

163

Near-equilibrium growth of thick, high quality beta-SiC by sublimation  

NASA Technical Reports Server (NTRS)

A close spaced near-equilibrium growth technique was used to produce thick, high quality epitaxial layers of beta-silicon carbide. The process utilized a sublimation method to grow morphologically smooth layers. The beta silicon carbide growth layers varied from about 200 to 750 microns in thickness. Chemical vapor deposition grown, 2-10 microns, beta silicon carbide films were used as seeds at 1860 and 1910 C growth temperatures. The respective average growth rates were 20 and 30 microns per hour. The layers are p-type with a 3.1 x 10 exp 17/cu cm carrier concentration. Electrical measurements indicate considerable improvement in the breakdown voltage of Schottky barriers on growth samples. Breakdown values ranged from 25 to 60 V. These measurements represent the highest values reported for 3C-SiC.

Shields, Virgil B.; Fekade, Konjit; Spencer, Michael G.

1993-01-01

164

MHD instabilities and their control in high-beta plasmas in KSTAR  

SciTech Connect

We established 3 specific tasks as follows: Task 1 - Investigate the MHD activity during the current ramp-up phase with shaped plasmas; Task 2 - Develop a theoretical model that may show the hollowness dependent instability; Task 3 - Explore the beta-limiting instabilities. To address each task, FAR-TECH actively participated in the 2012 KSTAR run-campaign, which helped us make productive progress. Specifically, the shaping dependence of MHD activity during current ramp-up phase was investigated using dedicated run-time in KSTAR (October 4 and 9, 2012), which was also attempted to address the hollowness of temperature (or pressure) profiles. Also, a performance-limiting disruption, which occurred in a relatively high intermediate beta plasma (shot 7110) in KSTAR ({beta}{sub N} ~ 1.7), was studied, and the preliminary analysis shows that the disruption might not be stability-limited but likely density-limited.

In, Yongkyoon

2013-02-06

165

Pulsed-Power-Driven High Energy Density Physics and Inertial Confinement Fusion Research  

Microsoft Academic Search

There continues to be dramatic progress in applying pulsed-power drivers to research in High Energy Density Physics (HEDP) and Inertial Confinement Fusion (ICF). The Z facility at Sandia National Laboratories delivers 20-MA load currents to create high magnetic fields (> 1000 T) and pressures (Mbar to Gbar). In a z-pinch configuration, the magnetic pressure (Lorentz Force) supersonically implodes a plasma

M. Keith Matzen; Maurice Keith

2004-01-01

166

High power negative ion sources for fusion at the Japan Atomic Energy Research Institute (invited)  

Microsoft Academic Search

Technologies producing high power negative ion beams have been highly developed over the years at Japan Atomic Energy Research Institute for use in neutral beam injectors for heating the thermonuclear fusion plasmas. At present, it is possible to produce multiampere H?\\/D? ion beams quasicontinuously at energies of more than a few hundred keV with a good beam optics of beamlet

Y. Okumura; Y. Fujiwara; T. Inoue; K. Miyamoto; N. Miyamoto; A. Nagase; Y. Ohara; K. Watanabe

1996-01-01

167

Common Fusion Transcripts Identified in Colorectal Cancer Cell Lines by High-Throughput RNA Sequencing12  

PubMed Central

Colorectal cancer (CRC) is the third most common cancer disease in the Western world, and about 40% of the patients die from this disease. The cancer cells are commonly genetically unstable, but only a few low-frequency recurrent fusion genes have so far been reported for this disease. In this study, we present a thorough search for novel fusion transcripts in CRC using high-throughput RNA sequencing. From altogether 220 million paired-end sequence reads from seven CRC cell lines, we identified 3391 candidate fused transcripts. By stringent requirements, we nominated 11 candidate fusion transcripts for further experimental validation, of which 10 were positive by reverse transcription-polymerase chain reaction and Sanger sequencing. Six were intrachromosomal fusion transcripts, and interestingly, three of these, AKAP13-PDE8A, COMMD10-AP3S1, and CTB-35F21.1-PSD2, were present in, respectively, 18, 18, and 20 of 21 analyzed cell lines and in, respectively, 18, 61, and 48 (17%-58%) of 106 primary cancer tissues. These three fusion transcripts were also detected in 2 to 4 of 14 normal colonic mucosa samples (14%28%). Whole-genome sequencing identified a specific genomic breakpoint in COMMD10-AP3S1 and further indicates that both the COMMD10-AP3S1 and AKAP13-PDE8A fusion transcripts are due to genomic duplications in specific cell lines. In conclusion, we have identified AKAP13-PDE8A, COMMD10-AP3S1, and CTB-35F21.1-PSD2 as novel intrachromosomal fusion transcripts and the most highly recurring chimeric transcripts described for CRC to date. The functional and clinical relevance of these chimeric RNA molecules remains to be elucidated. PMID:24151535

Nome, Torfinn; Thomassen, Gard OS; Bruun, Jarle; Ahlquist, Terje; Bakken, Anne C; Hoff, Andreas M; Rognum, Torleiv; Nesbakken, Arild; Lorenz, Susanne; Sun, Jinchang; Barros-Silva, Joo Diogo; Lind, Guro E; Myklebost, Ola; Teixeira, Manuel R; Meza-Zepeda, Leonardo A; Lothe, Ragnhild A; Skotheim, Rolf I

2013-01-01

168

ERp46 is reduced by high glucose and regulates insulin content in pancreatic beta-cells.  

PubMed

Our studies focus on ERp46, an endoplasmic reticulum (ER) component, and analyze its involvement in glucose toxicity and in insulin production. Differences in pancreatic beta-TC-6 cell proteome under conditions of low vs. high glucose were examined by proteomic approaches, including two-dimensional gel electrophoresis, image analysis, and mass spectrometry. Among differentially expressed proteins, ERp46, a novel endoplasmic reticulum component, was examined further. The expression of ERp46 in pancreatic sections was analyzed by immunocytochemistry, and high glucose-induced alterations of expression were evaluated in cultured beta-cells, in isolated pancreatic islets, and in the pancreas of db/db diabetic animals. Inhibition of ERp46 expression by siRNA was performed to study its role in insulin production, in secretion, and in ER stress. Proteomic analysis led to identification of 46 differentially expressed spots corresponding to 23 proteins. Since ERp46 is a novel protein with a possible crucial role in secretory cells, we further analyzed its role in beta-cell function. ERp46 expression is reduced in high glucose concentration in beta-TC-6 cells and in isolated murine islets. Further analysis revealed high expression of ERp46 in pancreatic islets compared with exocrine tissue. Interestingly, a marked decrease in ERp46 expression was found in the pancreatic islets of db/db mice. Most importantly, siRNA-mediated knockdown of ERp46 in cultured beta-cells led to a significant decrease in the insulin content; however, no alterations in insulin mRNA levels were observed under these conditions. In addition, reduced expression of ERp46 by siRNA increased the expression of CHOP and peIF2a, indicating development of ER stress. We conclude that ERp46 may be an important component in the phenomenon of "glucose toxicity" involved in insulin production at the posttranslational level. PMID:19622788

Alberti, Avra; Karamessinis, Panagiotis; Peroulis, Michalis; Kypreou, Katerina; Kavvadas, Panagiotis; Pagakis, Stamatis; Politis, Panagiotis K; Charonis, Aristidis

2009-09-01

169

Proteasome Dysfunction Mediates High Glucose-Induced Apoptosis in Rodent Beta Cells and Human Islets  

PubMed Central

The ubiquitin/proteasome system (UPS), a major cellular protein degradation machinery, plays key roles in the regulation of many cell functions. Glucotoxicity mediated by chronic hyperglycaemia is detrimental to the function and survival of pancreatic beta cells. The aim of our study was to determine whether proteasome dysfunction could be involved in beta cell apoptosis in glucotoxic conditions, and to evaluate whether such a dysfunction might be pharmacologically corrected. Therefore, UPS activity was measured in GK rats islets, INS-1E beta cells or human islets after high glucose and/or UPS inhibitor exposure. Immunoblotting was used to quantify polyubiquitinated proteins, endoplasmic reticulum (ER) stress through CHOP expression, and apoptosis through the cleavage of PARP and caspase-3, whereas total cell death was detected through histone-associated DNA fragments measurement. In vitro, we found that chronic exposure of INS-1E cells to high glucose concentrations significantly decreases the three proteasome activities by 20% and leads to caspase-3-dependent apoptosis. We showed that pharmacological blockade of UPS activity by 20% leads to apoptosis in a same way. Indeed, ER stress was involved in both conditions. These results were confirmed in human islets, and proteasome activities were also decreased in hyperglycemic GK rats islets. Moreover, we observed that a high glucose treatment hypersensitized beta cells to the apoptotic effect of proteasome inhibitors. Noteworthily, the decreased proteasome activity can be corrected with Exendin-4, which also protected against glucotoxicity-induced apoptosis. Taken together, our findings reveal an important role of proteasome activity in high glucose-induced beta cell apoptosis, potentially linking ER stress and glucotoxicity. These proteasome dysfunctions can be reversed by a GLP-1 analog. Thus, UPS may be a potent target to treat deleterious metabolic conditions leading to type 2 diabetes. PMID:24642635

Broca, Christophe; Varin, Elodie; Armanet, Mathieu; Tourrel-Cuzin, Ccile; Bosco, Domenico; Dalle, Stphane; Wojtusciszyn, Anne

2014-01-01

170

High-Yield Lithium-Injection Fusion-Energy (HYLIFE) reactor  

SciTech Connect

The High-Yield Lithium-Injection Fusion Energy (HYLIFE) concept to convent inertial confinement fusion energy into electric power has undergone intensive research and refinement at LLNL since 1978. This paper reports on the final HYLIFE design, focusing on five major areas: the HYLIFE reaction chamber (which includes neutronics, liquid-metal jet-array hydrocynamics, and structural design), supporting systems, primary steam system and balance of plant, safety and environmental protection, and costs. An annotated bibliography of reports applicable to HYLIFE is also provided. We conclude that HYLIFE is a particularly viable concept for the safe, clean production of electrical energy. The liquid-metal jet array, HYLIFE's key design feature, protects the surrounding structural components from x-rays, fusion fuel-pellet debris, neutron damage and activation, and high temperatures and stresses, allowing the structure to last for the plant's entire 30-year lifetime without being replaced. 127 refs., 18 figs.

Blink, J.A.; Hogam, W.J.; Hovingh, J.; Meier, E.R.; Pitts, J.H. (comps.)

1985-12-23

171

High-adiabat high-foot inertial confinement fusion implosion experiments on the national ignition facility.  

PubMed

This Letter reports on a series of high-adiabat implosions of cryogenic layered deuterium-tritium (DT) capsules indirectly driven by a "high-foot" laser drive pulse at the National Ignition Facility. High-foot implosions have high ablation velocities and large density gradient scale lengths and are more resistant to ablation-front Rayleigh-Taylor instability induced mixing of ablator material into the DT hot spot. Indeed, the observed hot spot mix in these implosions was low and the measured neutron yields were typically 50% (or higher) of the yields predicted by simulation. On one high performing shot (N130812), 1.7 MJ of laser energy at a peak power of 350 TW was used to obtain a peak hohlraum radiation temperature of ?300??eV. The resulting experimental neutron yield was (2.40.05)10(15) DT, the fuel ?R was (0.860.063)??g/cm2, and the measured Tion was (4.20.16)??keV, corresponding to 8 kJ of fusion yield, with ?1/3 of the yield caused by self-heating of the fuel by ? particles emitted in the initial reactions. The generalized Lawson criteria, an ignition metric, was 0.43 and the neutron yield was ?70% of the value predicted by simulations that include ?-particle self-heating. PMID:24580603

Park, H-S; Hurricane, O A; Callahan, D A; Casey, D T; Dewald, E L; Dittrich, T R; Dppner, T; Hinkel, D E; Berzak Hopkins, L F; Le Pape, S; Ma, T; Patel, P K; Remington, B A; Robey, H F; Salmonson, J D; Kline, J L

2014-02-01

172

High-Adiabat High-Foot Inertial Confinement Fusion Implosion Experiments on the National Ignition Facility  

NASA Astrophysics Data System (ADS)

This Letter reports on a series of high-adiabat implosions of cryogenic layered deuterium-tritium (DT) capsules indirectly driven by a "high-foot" laser drive pulse at the National Ignition Facility. High-foot implosions have high ablation velocities and large density gradient scale lengths and are more resistant to ablation-front Rayleigh-Taylor instability induced mixing of ablator material into the DT hot spot. Indeed, the observed hot spot mix in these implosions was low and the measured neutron yields were typically 50% (or higher) of the yields predicted by simulation. On one high performing shot (N130812), 1.7 MJ of laser energy at a peak power of 350 TW was used to obtain a peak hohlraum radiation temperature of 300 eV. The resulting experimental neutron yield was (2.40.05)1015 DT, the fuel ?R was (0.860.063) g/cm2, and the measured Tion was (4.20.16) keV, corresponding to 8 kJ of fusion yield, with 1/3 of the yield caused by self-heating of the fuel by ? particles emitted in the initial reactions. The generalized Lawson criteria, an ignition metric, was 0.43 and the neutron yield was 70% of the value predicted by simulations that include ?-particle self-heating.

Park, H.-S.; Hurricane, O. A.; Callahan, D. A.; Casey, D. T.; Dewald, E. L.; Dittrich, T. R.; Dppner, T.; Hinkel, D. E.; Berzak Hopkins, L. F.; Le Pape, S.; Ma, T.; Patel, P. K.; Remington, B. A.; Robey, H. F.; Salmonson, J. D.; Kline, J. L.

2014-02-01

173

Application of Magnetized Target Fusion to High-Energy Space Propulsion  

NASA Technical Reports Server (NTRS)

Most fusion propulsion concepts that have been investigated in the past employ some form of inertial or magnetic confinement. Although the prospective performance of these concepts is excellent, the fusion processes on which these concepts are based still require considerable development before they can be seriously considered for actual applications. Furthermore, these processes are encumbered by the need for sophisticated plasma and power handling systems that are generally quite inefficient and have historically resulted in large, massive spacecraft designs. Here we present a comparatively new approach, Magnetized Target Fusion (MTF), which offers a nearer-term avenue for realizing the tremendous performance benefits of fusion propulsion'. The key advantage of MTF is its less demanding requirements for driver energy and power processing. Additional features include: 1) very low system masses and volumes, 2) high gain and relatively low waste heat, 3) substantial utilization of energy from product neutrons, 4) efficient, low peak-power drivers based on existing pulsed power technology, and 5) very high Isp, specific power and thrust. MTF overcomes many of the problems associated with traditional fusion techniques, thus making it particularly attractive for space applications. Isp greater than 50,000 seconds and specific powers greater than 50 kilowatts/kilogram appear feasible using relatively near-term pulse power and plasma gun technology.

Thio, Y. C. F.; Schmidt, G. R.; Kirkpatrick, R. C.; Rodgers, Stephen L. (Technical Monitor)

2001-01-01

174

Possible Origin of Improved High Temperature Performance of Hydrothermally Aged Cu/Beta Zeolite Catalysts  

SciTech Connect

The hydrothermal stability of Cu/beta NH3 SCR catalysts are explored here. In particular, this paper focuses on the interesting ability of this catalyst to maintain and even enhance high-temperature performance for the "standard" SCR reaction after modest (900 C, 2 hours) hydrothermal aging. Characterization of the fresh and aged catalysts was performed with an aim to identify possible catalytic phases responsible for the enhanced high temperature performance. XRD, TEM and 27Al NMR all showed that the hydrothermally aging conditions used here resulted in almost complete loss of the beta zeolite structure between 1 and 2 hours aging. While the 27Al NMR spectra of 2 and 10 hour hydrothermally-aged catalysts showed significant loss of a peak associated with tetrahedrally-coordinated Al species, no new spectral features were evident. Two model catalysts, suggested by these characterization data as possible mimics of the catalytic phase formed during hydrothermal aging of Cu/beta, were prepared and tested for their performance in the "standard" SCR and NH3 oxidation reactions. The similarity in their reactivity compared to the 2 hour hydrothermally-aged Cu/beta catalyst suggests possible routes for preparing multi-component catalysts that may have wider temperature windows for optimum performance than those provided by current Cu/zeolite catalysts.

Peden, Charles HF; Kwak, Ja Hun; Burton, Sarah D.; Tonkyn, Russell G.; Kim, Do Heui; Lee, Jong H.; Jen, H. W.; Cavattaio, Giovanni; Cheng, Yisun; Lambert, Christine

2012-04-30

175

Cold fusion, Alchemist's dream  

SciTech Connect

In this report the following topics relating to cold fusion are discussed: muon catalysed cold fusion; piezonuclear fusion; sundry explanations pertaining to cold fusion; cosmic ray muon catalysed cold fusion; vibrational mechanisms in excited states of D{sub 2} molecules; barrier penetration probabilities within the hydrogenated metal lattice/piezonuclear fusion; branching ratios of D{sub 2} fusion at low energies; fusion of deuterons into {sup 4}He; secondary D+T fusion within the hydrogenated metal lattice; {sup 3}He to {sup 4}He ratio within the metal lattice; shock induced fusion; and anomalously high isotopic ratios of {sup 3}He/{sup 4}He.

Clayton, E.D.

1989-09-01

176

Design of the High Beta Cryomodule for the HIE-ISOLDE Upgrade at CERN  

E-print Network

The major upgrade of the energy and intensity of the existing ISOLDE and REX-ISOLDE facilities at CERN will require the replacement of most of the existing ISOLDE post-acceleration by a superconducting linac based on quarter-wave resonators. The first stage of this upgrade involves the design, construction, installation and commissioning of two high-? cryomodules downstream of REX, the existing post-accelerator. Each cryomodule houses five high-beta superconducting cavities and one superconducting solenoid. As well as providing optimum conditions for physics, where the internal active components must remain aligned within tight tolerances, the cryomodules need to function under stringent vacuum and cryogenic conditions. To preserve the RF cavity performance their assembly and sub-system testing will need to be carried out using specifically designed tooling in an ISO class 5 (US Fed. class 100) clean-room. We present the determining factors constraining the design of the high-beta cryomodules together with ...

Williams, L; Delruelle, N; Gayde, J C; Leclercq, Y; Pasini, M; Tock, J P; Vandoni, G

2011-01-01

177

High beta and confinement studies of TFTR. Progress report, April 15, 1992--April 14, 1993  

SciTech Connect

The project discussed in this report are: Enhanced High Poloidal Beta Operation in TFTR with Deuterium Pellet Injection; Approaching High Q by Utilizing High {beta}{sub p} Operation in TFTR; Advanced Tokamak Regime Experiment, and Second Regime Studies at large Major Radius High {beta}{sub p} Plasmas. Analysis of the data taken during these experiments as well as continuing analysis of earlier data led to a number important results described in publications in the past year including two invited presentations at the 1992 American Physical Society Division of Plasma Physics Meeting in Seattle an oral presentation at the 1992 IAEA Meeting in Wuertzburg, Germany, and a Physical Review Letter. These results included extending the high 11/2 regime to 1.2 MA current and neutron production rates to more than 3 {times} 10{sup 16} sec{sup {minus}}1; the first experiments with 4 sec neutral beam injection on TFRR; the creation of the first beam and bootstrap current sustained plasmas on TFTR for more than a current relaxation time scale; the first observation of ideal NM ballooning modes in a large tokamak; and production of plasmas with the inner 3/4 of the plasma in or with stable access to the second stability regime. The principal results of these papers and supporting theory work are summarized below.

Navratil, G.A.; Bhattacharjee, A.; Iacono, R.; Mauel, M.E.; Sabbagh, S.A. [Columbia Univ., New York, NY (United States); Kesner, J. [Massachusetts Inst. of Tech., Cambridge, MA (United States)

1993-07-01

178

Micro-engineered first wall tungsten armor for high average power laser fusion energy systems  

E-print Network

Micro-engineered first wall tungsten armor for high average power laser fusion energy systems implantation. Tungsten has been identified as the candidate material for a FW armor. The fundamental concern operation and exfoliation due to the retention of implanted helium. Even if a solid tungsten armor coating

Ghoniem, Nasr M.

179

Recent US advances in ion-beam-driven high energy density physics and heavy ion fusion  

Microsoft Academic Search

During the past two years, significant experimental and theoretical progress has been made in the US heavy ion fusion science program in longitudinal beam compression, ion-beam-driven warm dense matter, beam acceleration, high brightness beam transport, and advanced theory and numerical simulations. Innovations in longitudinal compression of intense ion beams by >50X propagating through background plasma enable initial beam target experiments

B. G. Logan; F. M. Bieniosek; C. M. Celata; J. Coleman; W. Greenway; E. Henestroza; J. W. Kwan; E. P. Lee; M. Leitner; P. K. Roy; P. A. Seidl; J.-L. Vay; W. L. Waldron; S. S. Yu; J. J. Barnard; R. H. Cohen; A. Friedman; D. P. Grote; M. Kireeff Covo; A. W. Molvik; S. M. Lund; W. R. Meier; W. Sharp; R. C. Davidson; P. C. Efthimion; E. P. Gilson; L. Grisham; I. D. Kaganovich; H. Qin; A. B. Sefkow; E. A. Startsev; D. Welch; C. Olson

2007-01-01

180

Development of high temperature superconducting current feeders for a large-scale superconducting experimental fusion system  

Microsoft Academic Search

The National Institute for Fusion Science (NIFS), in collaboration with universities and laboratories in Japan, the Forschungszentrum Karlsruhe (FZK) and the Max-Planck Institut fur Plasma Physik (IPP) in Germany, is planning to develop high temperature superconducting (HTS) current feeders for large-scale superconducting coils. Two programs are being progressed: one is a current feedthrough for superfluid helium (He II) cooled superconducting

T. Mito; K. Takahata; R. Heller; A. Iwamoto; R. Maekawa; H. Tamura; Y. Yamada; K. Tachikawa; K. Maehata; K. Ishibashi; G. Friesinger; M. Tasca; A. Nishimura; S. Yamada; S. Imagawa; N. Yanagi; H. Chikaraishi; S. Hamaguchi; M. Takeo; T. Shintomi; T. Satow; O. Motojima

2001-01-01

181

High heat flux issues for plasma-facing components in fusion reactors  

Microsoft Academic Search

Plasma facing components in tokamak fusion reactors are faced with a number of difficult high heat flux issues. These components include: first wall armor tiles, pumped limiters, diverter plates, rf antennae structure, and diagnostic probes. Peak heat fluxes are 15 - 30 MW\\/m2 for diverter plates, which will operate for 100 - 1000 seconds in future tokamaks. Disruption heat fluxes

Robert D. Watson

1993-01-01

182

A U.S. high-flux neutron facility for fusion materials development  

SciTech Connect

Materials for a fusion reactor first wall and blanket structure must be able to reliably function in an extreme environment that includes 10-15 MW-year/m{sup 2} neutron and heat fluences. The various materials and structural challenges are as difficult and important as achieving a burning plasma. Overcoming radiation damage degradation is the rate-controlling step in fusion materials development. Recent advances with oxide dispersion strengthened ferritic steels show promise in meeting reactor requirements, while multi-timescale atomistic simulations of defect-grain boundary interactions in model copper systems reveal surprising self-annealing phenomenon. While these results are promising, simultaneous evaluation of radiation effects displacement damage ({le} 200 dpa) and in-situ He generation ({le} 2000 appm) at prototypical reactor temperatures and chemical environments is still required. There is currently no experimental facility in the U.S. that can meet these requirements for macroscopic samples. The E.U. and U.S. fusion communities have recently concluded that a fusion-relevant, high-flux neutron source for accelerated characterization of the effects of radiation damage to materials is a top priority for the next decade. Data from this source will be needed to validate designs for the multi-$B next-generation fusion facilities such as the CTF, ETF, and DEMO, that are envisioned to follow ITER and NIF.

Rei, Donald J [Los Alamos National Laboratory

2010-01-01

183

Recurrent BCAM-AKT2 fusion gene leads to a constitutively activated AKT2 fusion kinase in high-grade serous ovarian carcinoma.  

PubMed

High-grade serous ovarian cancer (HGSC) is among the most lethal forms of cancer in women. Excessive genomic rearrangements, which are expected to create fusion oncogenes, are the hallmark of this cancer. Here we report a cancer-specific gene fusion between BCAM, a membrane adhesion molecule, and AKT2, a key kinase in the PI3K signaling pathway. This fusion is present in 7% of the 60 patient cancers tested, a significant frequency considering the highly heterogeneous nature of this malignancy. Further, we provide direct evidence that BCAM-AKT2 is translated into an in-frame fusion protein in the patient's tumor. The resulting AKT2 fusion kinase is membrane-associated, constitutively phosphorylated, and activated as a functional kinase in cells. Unlike endogenous AKT2, whose activity is tightly regulated by external stimuli, BCAM-AKT2 escapes the regulation from external stimuli. Moreover, a BCAM-AKT2 fusion gene generated via chromosomal translocation using the CRISPR/Cas9 system leads to focus formation in both OVCAR8 and HEK-293T cell lines, suggesting that BCAM-AKT2 is oncogenic. Together, the results indicate that BCAM-AKT2 expression is a new mechanism of AKT2 kinase activation in HGSC. BCAM-AKT2 is the only fusion gene in HGSC that is proven to translate an aberrant yet functional kinase fusion protein with oncogenic properties. This recurrent genomic alteration is a potential therapeutic target and marker of a clinically relevant subtype for tailored therapy of HGSC. PMID:25733895

Kannan, Kalpana; Coarfa, Cristian; Chao, Pei-Wen; Luo, Liming; Wang, Yan; Brinegar, Amy E; Hawkins, Shannon M; Milosavljevic, Aleksandar; Matzuk, Martin M; Yen, Laising

2015-03-17

184

Ra: A high efficiency, D-/sup 3/He, tandem mirror fusion reactor: Appendix C  

SciTech Connect

The Ra tandem mirror fusion reactor concept features inherent safety, high net plant efficiency, low cost of electricity, low radioactive waste generation, low activation, highly efficient direct conversion, thin radiation shields, and axisymmetric magnets. The safety and environmental features are achieved through the use of D/He-3 fuel, while the high efficiency derives from a new operating mode. ICRF stabilization allows an axisymmetric magnet set. 11 refs., 5 figs., 3 tabs.

Santarius, J.F.; Attaya, H.; Corradini, M.L.; El-Guebaly, L.A.; Emmert, G.A.; Kulcinski, G.L.; Larsen, E.M.; Maynard, C.W.; Musicki, Z.; Sawan, M.E.

1987-01-01

185

Fusion space propulsion with a field reversed configuration  

Microsoft Academic Search

The objective of this study is to examine a fusion space propulsion system using D-³He in a reversed field configuration (FRC). Such a configuration provides good confinement and high-..beta.. operation with high power densities in a compact design. The reversed field is maintained by a combination of fuel pellet injection and energetic fusion products which create an azimuthal plasma current.

R. Chapman; G. H. Miley; W. Kernbichler; M. Heindler

1989-01-01

186

Development of a high resolution beta camera for a direct measurement of positron distribution on brain surface  

Microsoft Academic Search

We have developed and tested a high resolution beta camera for a direct measurement of positron distribution on the brain surface of animals. The beta camera consists of a thin CaF2(Eu) scintillator, a tapered fiber optic plate (tapered fiber) and a position sensitive photomultiplier tube (PSPMT). The tapered fiber is the key component of the camera. We have developed two

S. Yamamoto; C. Seki; K. Kashikura; H. Fujita; T. Matsuda; R. Ban; I. Kanno

1997-01-01

187

MICRO-HETEROGENEITY AND MICRO-RHEOLOGICAL PROPERTIES OF HIGH-VISCOSITY OAT BETA-GLUCAN SOLUTIONS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soluble fiber beta-glucan is one of the key dietary materials in healthy food products known for reducing serum cholesterol levels. The micro-structural heterogeneity and micro-rheology of high-viscosity oat beta-glucan solutions were investigated by monitoring the thermally driven displacements of...

188

Cloning of the beta Cell High-Affinity Sulfonylurea Receptor: A Regulator of Insulin Secretion  

Microsoft Academic Search

Sulfonylureas are a class of drugs widely used to promote insulin secretion in the treatment of non-insulin-dependent diabetes mellitus. These drugs interact with the sulfonylurea receptor of pancreatic beta cells and inhibit the conductance of adenosine triphosphate (ATP)-dependent potassium (KATP) channels. Cloning of complementary DNAs for the high-affinity sulfonylurea receptor indicates that it is a member of the ATP-binding cassette

Lydia Aguilar-Bryan; Colin G. Nichols; Sergio W. Wechsler; John P. Clement IV; A. E. Boyd III; Gabriela Gonzalez; Haydee Herrera-Sosa; Kimberly Nguy; Joseph Bryan; Daniel A. Nelson

1995-01-01

189

Amyloid-beta binds catalase with high affinity and inhibits hydrogen peroxide breakdown.  

PubMed Central

Amyloid-beta (Abeta) specifically bound purified catalase with high affinity and inhibited catalase breakdown of H(2)O(2). The Abeta-induced catalase inhibition involved formation of the inactive catalase Compound II and was reversible. Catalase<-->Abeta interactions provide rapid functional assays for the cytotoxic domain of Abeta and suggest a mechanism for some of the observed actions of Abeta plus catalase in vitro. PMID:10567208

Milton, N G

1999-01-01

190

High beta and second stability region transport and stability analysis. Final report  

SciTech Connect

This report describes ideal and resistive studies of high-beta plasmas and of the second stability region. Emphasis is focused on ``supershot`` plasmas in TFIR where MHD instabilities are frequently observed and which spoil their confinement properties. Substantial results are described from the analysis of these high beta poloidal plasmas. During these studies, initial pressure and safety factor profiles were obtained from the TRANSP code, which is used extensively to analyze experimental data. Resistive MBD stability studies of supershot equilibria show that finite pressure stabilization of tearing modes is very strong in these high {beta}p plasmas. This has prompted a detailed re-examination of linear tearing mode theory in which we participated in collaboration with Columbia University and General Atomics. This finite pressure effect is shown to be highly sensitive to small scale details of the pressure profile. Even when an ad hoc method of removing this stabilizing mechanism is implemented, however, it is shown that there is only superficial agreement between resistive MBD stability computation and the experimental data. While the mode structures observed experimentally can be found computationally, there is no convincing correlation with the experimental observations when the computed results are compared with a large set of supershot data. We also describe both the ideal and resistive stability properties of TFIR equilibria near the transition to the second region. It is shown that the highest {beta} plasmas, although stable to infinite-n ideal ballooning modes, can be unstable to the so called ``infernal`` modes associated with small shear. The sensitivity of these results to the assumed pressure and current density profiles is discussed. Finally, we describe results from two collaborative studies with PPPL. The first involves exploratory studies of the role of the 1/1 mode in tokamaks and, secondly, a study of sawtooth stabilization using ICRF.

Hughes, M.H.; Phillps, M.W.; Todd, A.M.M.; Krishnaswami, J.; Hartley, R.

1992-09-01

191

High-statistics measurement of the beta-delayed alpha spectrum of 20Na  

E-print Network

A measurement of the 20Na beta-delayed alpha spectrum with a high-granularity set-up has allowed the decay scheme to be revised on several points. Three new transitions of low intensity are found at low alpha-particle energy. An R-matrix fit of the complete spectrum gives an improved description of the decay and indicates feeding to the broad 2^+ alpha-cluster state close to 9 MeV.

K. L. Laursen; O. S. Kirsebom; H. O. U. Fynbo; A. Jokinen; M. Madurga; K. Riisager.; A. Saastamoinen; O. Tengblad; J. ysto

2013-04-09

192

The investigation of high intensity laser driven micro neutron sources for fusion materials research at high fluence  

Microsoft Academic Search

The application of fast pulse, high intensity lasers to drive low cost DT point neutron sources for fusion materials testing at high flux\\/fluence is investigated. At present, high power bench-top lasers with intensities of 1018W\\/cm2 are routinely employed and systems capable of ? 1021 W\\/cm2 are becoming available. These potentially offer sufficient energy density for efficient neutron production in DT

L. J. Perkins; B. G. Logan; M. D. Rosen; M. D. Perry; T. Diaz de la Rubia; N. M. Ghoniem; T. Ditmire; P. T. Springer; S. C. Wilks

2000-01-01

193

Lipid Bilayer Vesicle Fusion: Intermediates Captured by High-Speed Microfluorescence Spectroscopy  

PubMed Central

The fusion of lipid bilayers can be visualized under the fluorescence microscope, but the process is very fast and requires special techniques for its study. It is reported here that vesicle fusion is susceptible to analysis by microspectrofluorometry and that for the first time, the entire fusion process has been captured. In the case of giant (>10-?m diameter) bilayer vesicles having a high density of opposite charge, fusion proceeds through stages of adhesion, flattening, hemifusion, elimination of the intervening septum, and uptake of excess membrane to generate a spherical product very rapidly. These investigations became possible with a fluorescence microscope that was modified for recording of images simultaneously with the collection of fluorescence emission spectra from many (>100) positions along the fusion axis. Positively-charged vesicles, composed of O-ethylphosphatidylcholine and dioleoylphosphatidylcholine, were labeled with a carbocyanine fluorophore. Negatively-charged vesicles, composed of dioleoylphosphatidylglycerol and dioleoylphosphatidylcholine, were labeled with a rhodamine fluorophore that is a resonance energy transfer acceptor from the carbocyanine fluorophore. An electrophoretic chamber allowed selection of pairs of vesicles to be brought into contact and examined. Spectral changes along the axis of fusion were captured at high speed (a few ms/frame) by operating a sensitive digital camera in the virtual-chip mode, a software/hardware procedure that permits rapid readout of selected regions of interest and by pixel binning along the spectral direction. Simultaneously, color images were collected at video rates (30 frame/s). Comparison of the spectra and images revealed that vesicle fusion typically passes through a hemifusion stage and that the time from vesicle contact to fusion is <10 ms. Fluorescence spectra are well suited to rapid collection in the virtual-chip mode because spectra (in contrast to images) are accurately characterized with a relatively small number of points and interfering signals can be removed by judicious choice of barrier filters. The system should be especially well-suited to phenomena exhibiting rapid fluorescence change along an axis; under optimal conditions, it is possible to obtain sets of spectra (wavelength range of ?150 nm) at >100 positions along a line at rates >1000 frames/s with a spectral resolution of ?10 nm and spatial resolution at the limit of the light microscope (?0.2 ?m). PMID:12944275

Lei, Guohua; MacDonald, Robert C.

2003-01-01

194

Oat beta-glucan ameliorates insulin resistance in mice fed on high-fat and high-fructose diet  

PubMed Central

Methods This study sought to evaluate the impact of oat beta-glucan on insulin resistance in mice fed on high-fat and high-fructose diet with fructose (10%, w/v) added in drinking water for 10 weeks. Results The results showed that supplementation with oat beta-glucan could significantly reduce the insulin resistance both in low-dose (200 mg/kg?1 body weight) and high-dose (500 mg/kg?1 body weight) groups, but the high-dose group showed a more significant improvement in insulin resistance (P<0.01) compared with model control (MC) group along with significant improvement in hepatic glycogen level, oral glucose, and insulin tolerance. Moreover, hepatic glucokinase activity was markedly enhanced both in low-dose and high-dose groups compared with that of MC group (P<0.05). Conclusion These results suggested that supplementation of oat beta-glucan alleviated insulin resistance and the effect was dose dependent. PMID:24371433

Zheng, Jie; Shen, Nanhui; Wang, Shuanghui; Zhao, Guohua

2013-01-01

195

Thermal analysis of a high-temperature falling bed fusion reactor blanket  

Microsoft Academic Search

A high temperature, falling bed blanket has been designed for a tokamak fusion reactor. The design centers on the use of a gravity flow of 0.5 to 1.5 cm diameter AlO balls as the high temperature heat transfer media. This system has the advantage of being able to produce process heat at temperatures in excess of 1000°C while maintaining structural

J. F. DePaz; S. D. Harkness

1979-01-01

196

Thermal and structural design aspects of high-temperature blankets for fusion synfuel production  

SciTech Connect

The most promising process, high temperature electrolysis (HTE) of steam at temperatures of greater than or equal to 1000/sup 0/C is examined. In HTE, a large fraction (up to approx. 50%) of the energy input to split water to hydrogen and oxygen comes from thermal energy. For the projected operating conditions achieved by high temperature fusion blankets, overall efficiencies for hydrogen production should be on the order of 60%. The design, thermal-hydraulics, and materials for such blankets are discussed.

Powell, J.R.; Fillo, J.A.; Reich, M.

1981-01-01

197

Physics of laser fusion. Volume III. High-power pulsed lasers  

SciTech Connect

High-power pulsed lasers can deliver sufficient energy on inertial-confinement fusion (ICF) time scales (0.1 to 10 ns) to heat and compress deuterium-tritium fuel to fusion-reaction conditions. Several laser systems have been examined, including Nd:glass, CO/sub 2/, KrF, and I/sub 2/, for their ICF applicability. A great deal of developmental effort has been applied to the Nd:glass laser and the CO/sub 2/ gas laser systems; these systems now deliver > 10/sup 4/ J and 20 x 10/sup 12/ W to ICF targets. We are constructing the Nova Nd:glass laser at LLNL to provide > 100 kJ and > 100 x 10/sup 12/ W of 1-..mu..m radiation for fusion experimentation in the mid-1980s. For ICF target gain > 100 times the laser input, we expect that the laser driver must deliver approx. 3 to 5 MJ of energy on a time scale of 10 to 20 ns. In this paper we review the technological status of fusion-laser systems and outline approaches to constructing high-power pulsed laser drivers.

Holzrichter, J.F.; Eimerl, D.; George, E.V.; Trenholme, J.B.; Simmons, W.W.; Hunt, J.T.

1982-09-01

198

Current Activities Assessing Butt Fusion Joint Integrity in High Density Polyethylene Piping  

SciTech Connect

The Pacific Northwest National Laboratory (PNNL) in Richland, Washington, conducted initial studies to evaluate the effectiveness of nondestructive examinations (NDE) coupled with mechanical testing for assessing butt fusion joint integrity in high density polyethylene (HDPE) pipe. The work provided insightful information to the United States Nuclear Regulatory Commission (NRC) on the effectiveness of volumetric inspection techniques for detecting lack of fusion (LOF) conditions in the fusion joints. HDPE has been installed on a limited basis in American Society of Mechanical Engineers (ASME) Class 3, buried piping systems at several operating U.S. nuclear power plants and has been proposed for use in new construction. A comparison was made between the results from ultrasonic and microwave nondestructive examinations and the results from mechanical destructive evaluations, specifically the high-speed tensile test and the side-bend test, for determining joint integrity. The data comparison revealed that none of the NDE techniques detected all of the lack-of-fusion conditions that were revealed by the destructive tests. Follow-on work has recently been initiated at PNNL to accurately characterize the NDE responses from machined flaws of varying size and location in PE 4710 materials as well as the LOF condition. This effort is directed at quantifying the ability of volumetric NDE techniques to detect flaws in relation to the critical flaw size associated with joint integrity. A status of these latest investigations is presented.

Crawford, Susan L.; Cinson, Anthony D.; Doctor, Steven R.; Denslow, Kayte M.

2012-09-01

199

High power lasers- their industrial and fusion applications  

NASA Astrophysics Data System (ADS)

Industrial and research uses of high power lasers are discussed, stressing the use of solid state and gas lasers for material processing, measuring magnetically confined plasma and creating localized plasmas

Spalding, I. J.

1980-08-01

200

KSTAR Equilibrium Operating Space and Projected Stabilization at High Normalized Beta  

SciTech Connect

Along with an expanded evaluation of the equilibrium operating space of the Korea Superconducting Tokamak Advanced Research, KSTAR, experimental equilibria of the most recent plasma discharges were reconstructed using the EFIT code. In near-circular plasmas created in 2009, equilibria reached a stored energy of 54 kJ with a maximum plasma current of 0.34 MA. Highly shaped plasmas with near double-null configuration in 2010 achieved H-mode with clear edge localized mode (ELM) activity, and transiently reached a stored energy of up to 257 kJ, elongation of 1.96 and normalized beta of 1.3. The plasma current reached 0.7 MA. Projecting active and passive stabilization of global MHD instabilities for operation above the ideal no-wall beta limit using the designed control hardware was also considered. Kinetic modification of the ideal MHD n = 1 stability criterion was computed by the MISK code on KSTAR theoretical equilibria with a plasma current of 2 MA, internal inductance of 0.7 and normalized beta of 4.0 with simple density, temperature and rotation profiles. The steep edge pressure gradient of this equilibrium resulted in the need for significant plasma toroidal rotation to allow thermal particle kinetic resonances to stabilize the resistive wall mode (RWM). The impact of various materials and electrical connections of the passive stabilizing plates on RWM growth rates was analysed, and copper plates reduced the RWM passive growth rate by a factor of 15 compared with stainless steel plates at a normalized beta of 4.4. Computations of active RWM control using the VALEN code showed that the n = 1 mode can be stabilized at normalized beta near the ideal wall limit via control fields produced by the midplane in-vessel control coils (IVCCs) with as low as 0.83kW control power using ideal control system assumptions. The ELM mitigation potential of the IVCC, examined by evaluating the vacuum island overlap created by resonant magnetic perturbations, was analysed using the TRIP3D code. Using a combination of all IVCCs with dominant n = 2 field and upper/lower coils in an even parity configuration, a Chirikov parameter near unity at normalized poloidal flux 0.83, an empirically determined condition for ELM mitigation in DIII-D, was generated in theoretical high-beta equilibria. Chirikov profile optimization was addressed in terms of coil parity and safety factor profile.

Park, Y. S. [Columbia University; Sabbagh, S. A. [Columbia University; Berkery, J.W. [Columbia University; Bialek, J. [Columbia University; Jeon, Y. M. [National Fusion Research Institute, Daejon, South Korea; Hahn, S. H. [National Fusion Research Institute, Daejon, South Korea; Eidietis, N. W. [General Atomics, San Diego; Evans, T. E. [General Atomics, San Diego; Yoon, S. W. [National Fusion Research Institute, Daejon, South Korea; Ahn, Joonwook [ORNL; Kim, J. [National Fusion Research Institute, Daejon, South Korea; Yang, H. L. [National Fusion Research Institute, Daejon, South Korea; You, K. I. [National Fusion Research Institute, Daejon, South Korea; Soukhanovskii, V. A. [Lawrence Livermore National Laboratory (LLNL); Bae, Y. S. [National Fusion Research Institute, Daejon, South Korea; Chung, J. I. [National Fusion Research Institute, Daejon, South Korea; Kwon, M. [National Fusion Research Institute, Daejon, South Korea; Oh, Y. K. [National Fusion Research Institute, Daejon, South Korea; Kim, W. C. [National Fusion Research Institute, Daejon, South Korea; Kim, J. Y. [National Fusion Research Institute, Daejon, South Korea; Lee, S. G. [National Fusion Research Institute, Daejon, South Korea; Park, H. [Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea; Reimerdes, H. [Columbia University; Leuer, J. A. [General Atomics, San Diego; Walker, M. L. [General Atomics, San Diego

2011-01-01

201

High levels of GM(1)-ganglioside and GM(1)-ganglioside beta-galactosidase in the parotid gland: a new model for secretory mechanisms of the parotid gland.  

PubMed

A new model for the subcellular basis of parotid secretion is presented in this article. GM(1)-ganglioside, typically found in neural tissues, is shown to be abundant in the parotid gland. This ganglioside may play a central role in membrane turnover mechanisms underlying exocytosis/endocytosis in its role as a promoter of membrane fusion or a fusogen. The lysosome and lysosomal hydrolases also play a central role in this model in catabolism of GM(1)-ganglioside. Consequently, high levels of the lysosomal hydrolase acidic beta-galactosidase are demonstrated in the salivary gland. GM(1)-gangliosidosis of the parotid glands, as described in mice, appears to be the first single-gene heritable disease found so far in the salivary glands. PMID:10477786

Nowroozi, N; Kim, S; Segawa, A; Warita, H; Rice, D H; Denny, P C; Zernik, J H

1999-10-01

202

The Structure of the Amyloid-[beta] Peptide High-Affinity Copper II Binding Site in Alzheimer Disease  

SciTech Connect

Neurodegeneration observed in Alzheimer disease (AD) is believed to be related to the toxicity from reactive oxygen species (ROS) produced in the brain by the amyloid-{beta} (A{beta}) protein bound primarily to copper ions. The evidence for an oxidative stress role of A{beta}-Cu redox chemistry is still incomplete. Details of the copper binding site in A{beta} may be critical to the etiology of AD. Here we present the structure determined by combining x-ray absorption spectroscopy (XAS) and density functional theory analysis of A{beta} peptides complexed with Cu{sup 2+} in solution under a range of buffer conditions. Phosphate-buffered saline buffer salt (NaCl) concentration does not affect the high-affinity copper binding mode but alters the second coordination sphere. The XAS spectra for truncated and full-length A{beta}-Cu{sup 2+} peptides are similar. The novel distorted six-coordinated (3N3O) geometry around copper in the A{beta}-Cu{sup 2+} complexes include three histidines: glutamic, or/and aspartic acid, and axial water. The structure of the high-affinity Cu{sup 2+} binding site is consistent with the hypothesis that the redox activity of the metal ion bound to A{beta} can lead to the formation of dityrosine-linked dimers found in AD.

Streltsov, Victor A.; Titmuss, Stephen J.; Epa, V. Chandana; Barnham, Kevin J.; Masters, Colin L.; Varghese, Joseph N. (CSIRO/MHT)

2008-11-03

203

Automatic registration and fusion of high resolution micro-CT and lung perfusion SPECT images of the rat  

Microsoft Academic Search

Small animal imaging can provide high-throughput phenotypic data for functional genomic studies and better mechanistic understanding of disease. Fusion of anatomical and functional images will aid interpretation of functional images having relatively little anatomical detail. In this study, we are investigating automatic registration and fusion visualization methods for micro-CT and SPECT images of rat lung. The immediate application is studies

Baowei Fei; Christian Wietholt; Anne V. Clough; Christopher A. Dawson; David L. Wilson

2003-01-01

204

Dust in fusion devices---a multi-faceted problem connecting high- and low-temperature plasma physics  

Microsoft Academic Search

Small particles with sizes between a few nanometers and a few 10 m (dust) are formed in fusion devices by plasma surface interaction processes. Though it is not a major problem today, dust is considered a problem that could arise in future long pulse fusion devices. This is primarily due to its radioactivity and due to its very high chemical

J. Winter

2004-01-01

205

The use of neutral beam heating to produce high performance fusion plasmas, including the injection of tritium beams into the Joint European Torus (JET)  

SciTech Connect

The neutral beam injection (NBI) system of the Joint European Torus (JET) [[ital Plasma] [ital Physics] [ital and] [ital Controlled] [ital Nuclear] [ital Fusion] [ital Research] (International Atomic Energy Agency, Vienna, 1985), Vol. 1, p. 11] has proved to be an extremely effective and flexible heating method capable of producing high performance plasmas and performing a wide range of related physics experiments. High fusion performance deuterium plasmas have been obtained in the hot-ion (HI) H-mode regime, using the central particle fueling and ion heating capabilities of the NBI system in low target density plasmas, and in the pellet enhanced plasma (PEP) H-mode regime, where the good central confinement properties of pellet fueled plasmas are exploited by additional heating and fueling as well as the transition to H mode. The HI H-mode configuration was used for the First Tritium Experiment (FTE) in JET in which NBI was used to heat the plasma using 14 D[sup 0] beams and, for the first time, to inject T[sup 0] using the two remaining beams. These plasmas had a peak fusion power of 1.7 MW from deuterium--tritium (D--T) fusion reactions. The capability for injection of a variety of beam species (H[sup 0], D[sup 0], [sup 3]He[sup 0], and [sup 4]He[sup 0]) has allowed the study of confinement variation with atomic mass and the simulation of [alpha]-particle transport. Additionally, the use of the NBI system has permitted an investigation of the plasma behavior near the toroidal [beta] limit over a wide range of toroidal field strengths.

Thompson, E.; Stork, D.; de Esch, H.P.L. (JET Joint Undertaking, Abingdon, Oxon 0X14 3EA (United Kingdom)); the JET Team

1993-07-01

206

Inertial Confinement Fusion: steady progressInertial Confinement Fusion: steady progress towards ignition and high gaintowards ignition and high gain  

E-print Network

ignition and high gaintowards ignition and high gain (summary talk)(summary talk) M. M. Basko Institute, Vilamoura, Portugal. #12;Main route to ignition: indirect laser drive with central hot-spot ignition and ignition implosion DT capsule hohlraum case ~ 30 m of Au (or Pb)µ laser beams 5.5 mm 9.5 mm ablator DT ice

207

High-Pressure Raman and X-ray Diffraction Study of [beta]- and [gamma]-Polymorphs of Aluminum Hydride  

SciTech Connect

Three polymorphs of alane, AlH{sub 3}, ({alpha}, {beta}, and {gamma}) were synthesized and studied at high-pressure in diamond anvil cell by Raman spectroscopy and synchrotron X-ray diffraction. According to synchrotron X-ray diffraction study, {beta}-AlH{sub 3} is stable up to 6 GPa, followed by transformation into {alpha} phase at higher pressures. X-ray-induced decomposition {gamma}-AlH{sub 3} into constituent elements was found at 15 GPa. Raman scattering study at high pressure for both {beta}- and {gamma}-AlH{sub 3} reveals transition into the {alpha} phase with high concentration of structural defects. DFT calculations (VASP code) show that instability of cubic {beta}-alane crystal structure at high pressure is caused by the strong deformation of the [AlH{sub 6}] polyhedra.

Drozd, Vadym; Garimella, Subrahmanyam; Saxena, Surendra; Chen, Jiuhua; Palasyuk, Taras (FIU); (IPC-Romania)

2012-03-26

208

Effect of a ferromagnetic wall on low beta tearing modes in the Japan Atomic Energy Research Institute Fusion Torus2 Modified  

Microsoft Academic Search

A ferritic steel wall, which might be employed in fusion demonstration reactors, has been installed in Japan Atomic Energy Research Institute Fusion Torus-2 Modified [Nucl. Fusion 41, 257 (2001)] to study the applicability of ferromagnetic walls to plasmas. The tearing mode equation is solved in presence of a ferromagnetic\\/resistive wall to study the effect of the ferromagnetism on the tearing

M. Bakhtiari; M. Azumi; K. Tsuzuki; K. Kamiya; H. Kawashima; Y. Kusama; M. Sato; K. Hoshino

2003-01-01

209

Development of a high resolution beta camera for a direct measurement of positron distribution on brain surface  

SciTech Connect

We have developed and tested a high resolution beta camera for a direct measurement of positron distribution on brain surface of animals. The beta camera consists of a thin CaF{sub 2}(Eu) scintillator, a tapered fiber optics plate (taper fiber) and a position sensitive photomultiplier tube (PSPMT). The taper fiber is the key component of the camera. We have developed two types of beta cameras. One is 20mm diameter field of view camera for imaging brain surface of cats. The other is 10mm diameter camera for that of rats. Spatial resolutions of beta camera for cats and rats were 0.8mm FWHM and 0.5mm FWHM, respectively. We confirmed that developed beta cameras may overcome the limitation of the spatial resolution of the positron emission tomography (PET).

Yamamoto, S. [Kobe City College of Technology, Nishi-ku (Japan); Seki, C.; Kashikura, K. [Akita Lab. (Japan)] [and others

1996-12-31

210

Occurrence of high-beta superthermal plasma events in the close environment of Jupiter's bow shock as observed by Ulysses  

SciTech Connect

The ratio of the plasma pressure to the magnetic field pressure (or of their energy densities) which is known as the plasma parameter 'beta'({beta}) has important implications to the propagation of energetic particles and the interaction of the solar wind with planetary magnetospheres. Although in the scientific literature the contribution of the superthermal particles to the plasma pressure is generally assumed negligible, we deduced, by analyzing energetic particles and magnetic field measurements recorded by the Ulysses spacecraft, that in a series of events, the energy density contained in the superthermal tail of the particle distribution is comparable to or even higher than the energy density of the magnetic field, creating conditions of high-beta plasma. More explicitly, in this paper we analyze Ulysses/HI-SCALE measurements of the energy density ratio (parameter {beta}{sub ep}) of the energetic ions'(20 keV to {approx}5 MeV) to the magnetic field's in order to find occurrences of high-beta ({beta}{sub ep}>1) superthermal plasma conditions in the environment of the Jovian magnetosphere, which is an interesting plasma laboratory and an important source of emissions in our solar system. In particular, we examine high-beta ion events close to Jupiter's bow shock, which are produced by two processes: (a) bow shock ion acceleration and (b) ion leakage from the magnetosphere.

Marhavilas, P. K.; Sarris, E. T.; Anagnostopoulos, G. C. [Space Research Laboratory, Democritus University of Thrace, Vas. Sofias 12 St., 67100 Xanthi (Greece)

2011-01-04

211

US heavy ion beam research for high energy density physics applications and fusion  

NASA Astrophysics Data System (ADS)

Key scientific results from recent experiments, modeling tools, and heavy ion accelerator research are summarized that explore ways to investigate the properties of high energy density matter in heavy-ion-driven targets, in particular, strongly-coupled plasmas at 0.01 to 0.1 times solid density for studies of warm dense matter, which is a frontier area in high energy density physics. Pursuit of these near-term objectives has resulted in many innovations that will ultimately benefit heavy ion inertial fusion energy. These include: neutralized ion beam compression and focusing, which hold the promise of greatly improving the stage between the accelerator and the target chamber in a fusion power plant; and the Pulse Line Ion Accelerator (PLIA), which may lead to compact, low-cost modular linac drivers.

Davidson, R. C.; Logan, B. G.; Barnard, J. J.; Bieniosek, F. M.; Briggs, R. J.; Callahan, D. A.; Kireeff Covo, M.; Celata, C. M.; Cohen, R. H.; Coleman, J. E.; Debonnel, C. S.; Grote, D. P.; Efthimion, P. C.; Eylon, S.; Friedman, A.; Gilson, E. P.; Grisham, L. R.; Henestroza, E.; Kaganovich, I. D.; Kwan, J. W.; Lee, E. P.; Lee, W. W.; Leitner, M.; Lund, S. M.; Meier, W. R.; Molvik, A. W.; Olson, C. L.; Penn, G. E.; Qin, H.; Roy, P. K.; Rose, D. V.; Sefkow, A.; Seidl, P. A.; Sharp, W. M.; Startsev, E. A.; Tabak, M.; Thoma, C.; Vay, J.-L.; Waldron, W. L.; Wurtele, J. S.; Welch, D. R.; Westenskow, G. A.; Yu, S. S.

2006-06-01

212

US Heavy Ion Beam Research for High Energy Density Physics Applications and Fusion  

SciTech Connect

Key scientific results from recent experiments, modeling tools, and heavy ion accelerator research are summarized that explore ways to investigate the properties of high energy density matter in heavy-ion-driven targets, in particular, strongly-coupled plasmas at 0.01 to 0.1 times solid density for studies of warm dense matter, which is a frontier area in high energy density physics. Pursuit of these near-term objectives has resulted in many innovations that will ultimately benefit heavy ion inertial fusion energy. These include: neutralized ion beam compression and focusing, which hold the promise of greatly improving the stage between the accelerator and the target chamber in a fusion power plant; and the Pulse Line Ion Accelerator (PLIA), which may lead to compact, low-cost modular linac drivers.

Davidson, R.C.; Logan, B.G.; Barnard, J.J.; Bieniosek, F.M.; Briggs, R.J.; et al.

2005-09-19

213

Collaborative technologies for distributed science: fusion energy and high-energy physics  

Microsoft Academic Search

This paper outlines a strategy to significantly enhance scientific collaborations in both Fusion Energy Sciences and in High-Energy Physics through the development and deployment of new tools and technologies into working environments. This strategy is divided into two main elements, collaborative workspaces and secure computational services. Experimental and theory\\/computational programs will greatly benefit through the provision of a flexible, standards-based

D. P. SCHISSEL; E E Gottschalk; M J Greenwald; D McCune

2006-01-01

214

LWR spent fuel transmutation in a high power density fusion reactor  

Microsoft Academic Search

The prospect of light water reactor (LWR) spent fuel incineration in a high power density fusion reactor has been investigated. The neutron wall load is taken at 10 MW\\/m2 and a refractory alloy (W-5Re) is used in the first wall. Neutron transport calculations are conducted over an operation period of 48 months on a simple experimental hybrid blanket in a

Smer ?ahin; Mustafa beyli

2004-01-01

215

Development of high intensity deuteron ion source for the fusion intense neutron source  

Microsoft Academic Search

A high intensity deuteron ion source has been developed in order to increase the neutron flax from the D-T neutron source for Fusion Neutronics Source at JAERI. It is possible to extract more than 50 mA of deuteron beam at the beam energy of 50 keV. The lifetime of the tungsten filaments utilized in the ion source has been achieved

M. Kinsho; M. Sugimoto; M. Seki; H. Oguri; Y. Okumura

2000-01-01

216

Development of a new concept ion source for high performance inertial electrostatic confinement fusion device  

Microsoft Academic Search

An Inertial Electrostatic Confinement Fusion (IECF) is a concept for retaining a plasma using an electrostatic potential well. It consists of two spherical grids inside the vacuum chamber. An insulated high voltage feed-through supplies power to the inner grid cathode, and a small amount of deuterium or tritium gas (0.1-1.0 Pa) is fed into the chamber. When the voltage is

Y. Taniuchi; Y. Matsumura; K. Taira; M. Utsumi

2010-01-01

217

The NIF: An international high energy density science and inertial fusion user facility  

NASA Astrophysics Data System (ADS)

The National Ignition Facility (NIF), a 1.8-MJ/500-TW Nd:Glass laser facility designed to study inertial confinement fusion (ICF) and high-energy-density science (HEDS), is operational at Lawrence Livermore National Laboratory (LLNL). A primary goal of NIF is to create the conditions necessary to demonstrate laboratory-scale thermonuclear ignition and burn. NIF experiments in support of indirect-drive ignition began late in FY2009 as part of the National Ignition Campaign (NIC), an international effort to achieve fusion ignition in the laboratory. To date, all of the capabilities to conduct implosion experiments are in place with the goal of demonstrating ignition and developing a predictable fusion experimental platform in 2012. The results from experiments completed are encouraging for the near-term achievement of ignition. Capsule implosion experiments at energies up to 1.6 MJ have demonstrated laser energetics, radiation temperatures, and symmetry control that scale to ignition conditions. Of particular importance is the demonstration of peak hohlraum temperatures near 300 eV with overall backscatter less than 15%. Important national security and basic science experiments have also been conducted on NIF. Successful demonstration of ignition and net energy gain on NIF will be a major step towards demonstrating the feasibility of laser-driven Inertial Fusion Energy (IFE). This paper will describe the results achieved so far on the path toward ignition, the beginning of fundamental science experiments and the plans to transition NIF to an international user facility providing access to HEDS and fusion energy researchers around the world.

Moses, E. I.; Storm, E.

2013-11-01

218

Anomalous fast ion losses at high ? on the tokamak fusion test reactor  

NASA Astrophysics Data System (ADS)

This paper describes experiments carried out on the Tokamak Fusion Test Reactor (TFTR) [R. J. Hawryluk et al., Plasma Phys. Controlled Fusion 33, 1509 (1991)] to investigate the dependence of ?-limiting disruption characteristics on toroidal field strength. The hard disruptions found at the ?-limit in high field plasmas were not found at low field, even for ?'s 50% higher than the empirical ?-limit of ?n ? 2 at high field. Comparisons of experimentally measured ?'s to TRANSP simulations suggest anomalous loss of up to half of the beam fast ions in the highest ?, low field shots. The anomalous transport responsible for the fast ion losses may at the same time broaden the pressure profile. Toroidal Alfvn eigenmodes, fishbone instabilities, and Geodesic Acoustic Modes are investigated as possible causes of the enhanced losses. Here, we present the first observations of high frequency fishbones [F. Zonca et al., Nucl. Fusion 49, 085009 (2009)] on TFTR. The interpretation of Axi-symmetric Beam-driven Modes as Geodesic Acoustic Modes and their possible correlation with transport barrier formation are also presented.

Fredrickson, E. D.; Bell, M. G.; Budny, R. V.; Darrow, D. S.; White, R.

2015-03-01

219

High performance manned interplanetary space vehicle using D-3He Inertial Electrostatic Fusion  

NASA Astrophysics Data System (ADS)

A preliminary system design is presented for a high performance 100 MWe manned space vehicle in the 500 metric ton class, based on Inertial Electrostatic Fusion (IEC), with trip times to the outer planets of several months. An IEC is chosen because it simplifies structure results in a very high power to weight ratio. The fusion reactor uses D-3He fuel which generates 14.7-MeV protons as the primary reaction product. The propulsion system design philosophy is based on direct conversion of proton energy to electricity, avoiding the thermalization of the working fluid to maximize efficiency. The principle system components of crew compartment, electronics, fusion reactor, traveling wave direct energy converter, step-down transformer, rectifier, ion thruster and heat rejection radiators are described. The design requires that an IEC reactor with a proton energy gain (power in 14.7-MeV protons/input electric power) of 4 or better is necessary to keep radiator mass and size at acceptable levels. Extrapolation of present laboratory scale IEC experiments to reactor relevant conditions is possible theoretically, but faces several open issues including stability under high-density conditions. Since unburned fusion fuels are recycled rather than exhausted with the propellant, problems of fuel weight and preservation of 3He are minimized. The 100-MWe propulsion system is based on NSTAR-extrapolated krypton ion thrusters operating at a specific impulse of 16,000 seconds and a total thrust of 1020 N. Thrust time for a typical outer planet mission ?V of 50,000 m/s is then ~200 days. .

Burton, R.; Momota, H.; Richardson, N.; Coventry, M.; Shaban, Y.; Miley, G. H.

2002-01-01

220

Hall effect and fine structures in magnetic reconnection with high plasma {beta}  

SciTech Connect

Magnetic reconnection with various plasma {beta} (the ratio of plasma pressure to the magnetic pressure) is studied numerically using a 2.5 dimensional Hall magnetohydrodynamics (MHD) code developed from a multistep implicit scheme. The initial state of the Hall MHD simulation is an equilibrium Harris sheet with L{sub c}=0.5d{sub i} (where L{sub c} is the half-width of the equilibrium current layer and d{sub i} is the ion inertial length) and a zero guide field (i.e., B{sub y0}=0 at t=0). Driven by a constant boundary inflow a quasisteady fast reconnection occurs in the plasma with a low uniform resistivity. The out-of-plane magnetic field component B{sub y} is then spontaneously generated and its quadrupolar structure is shown around the X point. It is demonstrated by the comparing studies that the reconnection dynamics is controlled by the Hall effect and the effect of scalar electron pressure gradient is negligible in the generalized Ohm's law. It is also found that the openness of the magnetic separatrix angle and associated quadrupolar B{sub y} structure is enlarged as {beta} increases. When {beta}>2.0 fine structures of B{sub y} contours with reversed sign emerge. The numerical results indicate that the variations in electron velocity V{sub e} are greater than those in ion velocity V{sub i} and the decoupling of electron and ion occurs in larger scale lengths than d{sub i} as {beta} increases. Clearly, the reserve current, which is associated with the relative motion between electrons and ions, generates the fine structures of B{sub y} contours in the outflow region. Then the corresponding profile of B{sub y} component exhibits a static whistler wave signature. Enhanced wave activities observed during a Cluster crossing of the high-{beta} exterior cusp region [Y. Khotyaintsev, A. Vaivads, Y. Ogawa, B. Popielawska, M. Andre, S. Buchert, P. Decreau, B. Lavraud, and H. Reme, Ann. Geophys. 22, 2403 (2004)] might be related to the Hall effects of magnetic reconnection shown in the present simulation.

Jin, S.P.; Yang, H.A.; Wang, X.G. [School of Earth and Space Sciences, University of Science and Technology of China, Anhui 230026 (China); Department of Physics and State Key Lab of Materials Modification by Beams, Dalian University of Technology, Liaoning 116024 (China)

2005-04-15

221

High pressure deuterium-tritium gas target vessels for muon-catalyzed fusion experiments  

SciTech Connect

In experimental studies of muon-catalyzed fusion, the density of the hydrogen gas mixture is an important parameter. Catalysis of up to 150 fusions per muon has been observed in deuterium-tritium gas mixtures at liquid hydrogen density; at room temperature, such densities require a target gas pressure of the order of 1000 atmospheres (100 MPa, 15,000 psi). We report here the design considerations for hydrogen gas target vessels for muon-catalyzed fusion experiments that operate at 1000 and 10,000 atmospheres. The 1000 atmosphere high pressure target vessels are fabricated of Type A-286 stainless steel and lined with oxygen-free, high-conductivity (OFHC) copper to provide a barrier to hydrogen permeation of the stainless steel. The 10,000 atmosphere ultrahigh pressure target vessels are made from 18Ni (200 grade) maraging steel and are lined with OFHC copper, again to prevent hydrogen permeation of the steel. In addition to target design features, operating requirements, fabrication procedures, and secondary containment are discussed. 13 refs., 3 figs., 1 tab.

Caffrey, A.J.; Spaletta, H.W.; Ware, A.G.; Zabriskie, J.M.; Hardwick, D.A.; Maltrud, H.R.; Paciotti, M.A. (EG and G Idaho, Inc., Idaho Falls, ID (USA); Los Alamos National Lab., NM (USA))

1989-01-01

222

Biomimetic supported lipid bilayers with high cholesterol content formed by ?-helical peptide-induced vesicle fusion  

PubMed Central

In this study, we present a technique to create a complex, high cholesterol-containing supported lipid bilayers (SLBs) using ?-helical (AH) peptide-induced vesicle fusion. Vesicles consisting of POPC : POPE : POPS : SM : Chol (9.35 : 19.25 : 8.25 : 18.15 : 45.00) were used to form a SLB that models the native composition of the human immunodeficiency virus-1 (HIV-1) lipid envelope. In the absence of AH peptides, these biomimetic vesicles fail to form a complete SLB. We verified and characterized AH peptide-induced vesicle fusion by quartz crystal microbalance with dissipation monitoring, neutron reflectivity, and atomic force microscopy. Successful SLB formation entailed a characteristic frequency shift of ?35.4 2.0 Hz and a change in dissipation energy of 1.91 0.52 10?6. Neutron reflectivity measurements determined the SLB thickness to be 49.9 +1.9?1.5 , and showed the SLB to be 100 +0.0?0.1% complete and void of residual AH peptide after washing. Atomic force microscopy imaging confirmed complete SLB formation and revealed three distinct domains with no visible defects. This vesicle fusion technique gives researchers access to a complex SLB composition with high cholesterol content and thus the ability to better recapitulate the native HIV-1 lipid membrane. PMID:23914075

Hardy, Gregory J.; Nayak, Rahul; Alam, S. Munir; Shapter, Joseph G.; Heinrich, Frank; Zauscher, Stefan

2013-01-01

223

Delta 5-3beta-hydroxysteroid dehydrogenase (3 beta HSD) from Digitalis lanata. Heterologous expression and characterisation of the recombinant enzyme.  

PubMed

During the biosynthesis of cardiac glycosides, Delta (5)-3beta-hydroxysteroid dehydrogenase (3 beta HSD, EC 1.1.1.51) converts pregnenolone (5-pregnen-3beta-ol-20-one) to isoprogesterone (5-pregnene-3,20-dione). A 3 beta HSD gene was isolated from leaves of Digitalis lanata. It consisted of 870 nucleotides containing a 90 nucleotide long intron. A full-length cDNA clone that encodes 3 beta HSD was isolated by RT-PCR from the same source. A SPH I /KPN I 3 beta HSD cDNA was cloned into the pQE30 vector and then transferred into E. COLI strain M15[pREP4]. 3 beta HSD cDNA was functionally expressed as a His-tagged fusion protein (pQ3 beta HSD) composed of 273 amino acids (calculated molecular mass 28,561 Da). pQ3 beta HSD was purified by metal chelate affinity chromatography on Ni-NTA. Pregnenolone and other 3beta-hydroxypregnanes but not cholesterol were 3beta-oxidised by pQ3 beta HSD when NAD was used as the co-substrate. Testosterone (4-androsten-17beta-ol-3-one) was converted to 4-androstene-3,17-dione indicating that the pQ3 beta HSD has also 17beta-dehydrogenase activity. pQ3 beta HSD was able to reduce 3-keto steroids to their corresponding 3beta-hydroxy derivatives when NADH was used as the co-substrate. For comparison, 3 beta HSD genes were isolated and sequenced from another 6 species of the genus DIGITALIS. Gene structure and the deduced 3 beta HSD proteins share a high degree of similarity. PMID:17564944

Herl, Vanessa; Frankenstein, Jrdis; Meitinger, Nadine; Mller-Uri, Frieder; Kreis, Wolfgang

2007-06-01

224

Direct drive heavy-ion-beam inertial fusion at high coupling efficiency  

SciTech Connect

Issues with coupling efficiency, beam illumination symmetry, and Rayleigh-Taylor instability are discussed for spherical heavy-ion-beam-driven targets with and without hohlraums. Efficient coupling of heavy-ion beams to compress direct-drive inertial fusion targets without hohlraums is found to require ion range increasing several-fold during the drive pulse. One-dimensional implosion calculations using the LASNEX inertial confinement fusion target physics code shows the ion range increasing fourfold during the drive pulse to keep ion energy deposition following closely behind the imploding ablation front, resulting in high coupling efficiencies (shell kinetic energy/incident beam energy of 16% to 18%). Ways to increase beam ion range while mitigating Rayleigh-Taylor instabilities are discussed for future work.

Logan, B.G.; Perkins, L.J.; Barnard, J.J.

2008-05-16

225

Universal antibodies against the highly conserved influenza fusion peptide cross-neutralize several subtypes of influenza A virus  

SciTech Connect

Research highlights: {yields} The fusion peptide is the only universally conserved epitope in all influenza viral hemagglutinins. {yields} Anti-fusion peptide antibodies are universal antibodies that cross-react with all influenza HA subtypes. {yields} The universal antibodies cross-neutralize different influenza A subtypes. {yields} The universal antibodies inhibit the fusion process between the viruses and the target cells. -- Abstract: The fusion peptide of influenza viral hemagglutinin plays a critical role in virus entry by facilitating membrane fusion between the virus and target cells. As the fusion peptide is the only universally conserved epitope in all influenza A and B viruses, it could be an attractive target for vaccine-induced immune responses. We previously reported that antibodies targeting the first 14 amino acids of the N-terminus of the fusion peptide could bind to virtually all influenza virus strains and quantify hemagglutinins in vaccines produced in embryonated eggs. Here we demonstrate that these universal antibodies bind to the viral hemagglutinins in native conformation presented in infected mammalian cell cultures and neutralize multiple subtypes of virus by inhibiting the pH-dependant fusion of viral and cellular membranes. These results suggest that this unique, highly-conserved linear sequence in viral hemagglutinin is exposed sufficiently to be attacked by the antibodies during the course of infection and merits further investigation because of potential importance in the protection against diverse strains of influenza viruses.

Hashem, Anwar M. [Centre for Vaccine Evaluation, Biologics and Genetic Therapies Directorate, HPFB, Health Canada, Ottawa, ON (Canada) [Centre for Vaccine Evaluation, Biologics and Genetic Therapies Directorate, HPFB, Health Canada, Ottawa, ON (Canada); Department of Microbiology, Faculty of Medicine, King Abdulaziz University, Jeddah (Saudi Arabia); Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON (Canada); Van Domselaar, Gary [National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB (Canada)] [National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB (Canada); Li, Changgui; Wang, Junzhi [National Institute for the Control of Pharmaceutical and Biological Products, Beijing (China)] [National Institute for the Control of Pharmaceutical and Biological Products, Beijing (China); She, Yi-Min; Cyr, Terry D. [Centre for Vaccine Evaluation, Biologics and Genetic Therapies Directorate, HPFB, Health Canada, Ottawa, ON (Canada)] [Centre for Vaccine Evaluation, Biologics and Genetic Therapies Directorate, HPFB, Health Canada, Ottawa, ON (Canada); Sui, Jianhua [Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Department of Medicine, Harvard Medical School, 44 Binney Street, Boston, MA 02115 (United States)] [Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Department of Medicine, Harvard Medical School, 44 Binney Street, Boston, MA 02115 (United States); He, Runtao [National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB (Canada)] [National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, MB (Canada); Marasco, Wayne A. [Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Department of Medicine, Harvard Medical School, 44 Binney Street, Boston, MA 02115 (United States)] [Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Department of Medicine, Harvard Medical School, 44 Binney Street, Boston, MA 02115 (United States); Li, Xuguang, E-mail: Sean.Li@hc-sc.gc.ca [Centre for Vaccine Evaluation, Biologics and Genetic Therapies Directorate, HPFB, Health Canada, Ottawa, ON (Canada) [Centre for Vaccine Evaluation, Biologics and Genetic Therapies Directorate, HPFB, Health Canada, Ottawa, ON (Canada); Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON (Canada)

2010-12-10

226

High LET Radiation Can Enhance TGF(Beta) Induced EMT and Cross-Talk with ATM Pathways  

NASA Technical Reports Server (NTRS)

The TGF(Beta) pathway has been shown to regulate or directly interact with the ATM pathway in the response to radiation in mammary epithelial cells. We investigated possible interactions between the TGF(Beta) and ATM pathways following simulated space radiation using hTERT immortalized human esophageal epithelial cells (EPC-hTERT), mink lung epithelial cells (Mv1lu), and several human fibroblast cell lines. TGF(Beta) is a key modulator of the Epithelial-Mesenchymal Transition (EMT), important in cancer progression and metastasis. The implication of EMT by radiation also has several lines of developing evidence, however is poorly understood. The identification of TGF(Beta) induced EMT can be shown in changes to morphology, related gene over expression or down regulation, which can be detected by RT-PCR, and immunostaining and western blotting. In this study, we have observed morphologic and molecular alternations consistent with EMT after Mv1lu cells were treated with TGF(Beta) High LET radiation enhanced TGF(Beta) mediated EMT with a dose as low as 0.1Gy. In order to consider the TGF(Beta) interaction with ATM we used a potent ATM inhibitor Ku55933 and investigated gene expression changes and Smad signaling kinetics. Ku559933 was observed to reverse TGF(Beta) induced EMT, while this was not observed in dual treated cells (radiation+TGF(Beta)). In EPC-hTERT cells, TGF(Beta) alone was not able to induce EMT after 3 days of application. A combined treatment with high LET, however, significantly caused the alteration of EMT markers. To study the function of p53 in the process of EMT, we knocked down P53 through RNA interference. Morphology changes associated with EMT were observed in epithelial cells with silenced p53. Our study indicates: high LET radiation can enhance TGF(Beta) induced EMT; while ATM is triggering the process of TGF(Beta)-induced EMT, p53 might be an essential repressor for EMT phenotypes.

Wang, Minli; Hada, Megumi; Huff, Janice; Pluth, Janice M.; Anderson, Janniffer; ONeill, Peter; Cucinotta, Francis A.

2010-01-01

227

High-Molecular-Weight Immunoreactive beta Endorphin in Extracts of Human Placenta is a Fragment of Immunoglobulin G  

Microsoft Academic Search

A high-molecular-weight protein with beta -endorphin- and adrenocorticotropin-immunoreactivities was isolated from extracts of human placenta after several purification steps, including immunoadsorption with a well-characterized antiserum raised to beta -endorphin. This protein was identified as the heavy chain of the human immunoglobulin class IgG1. These results have led to the recognition of homologies in the amino acid sequences of these physiologically

Jacques H. Julliard; Tamotsu Shibasaki; Nicholas Ling; Roger Guillemin

1980-01-01

228

A multiple window deconvolution technique for measuring low-energy beta activity in samples contaminated with high-energy beta impurities using liquid scintillation spectrometry  

PubMed

An optimised multiple window counting technique, using liquid scintillation counting combined with internal standardisation and spectrum unfolding has been developed for the assessment of low-level, low-energy beta activity in multilabeled samples containing high-energy beta impurities. Distinct spectral contributions are reconstructed for every individual radionuclide and impurity using software deconvolution techniques. The most important advantages of this method are that it does not require setting up quench correction curves and that the exact knowledge of reference activity is not required, thus eliminating two important sources of uncertainty in the final results. The technique has been successfully used on mixtures of 3H, 14C, 63Ni, 99Tc and 60Co over a wide range of quenching and activity ratios. PMID:10879875

Verrezen; Hurtgen

2000-07-01

229

Prospects for studying temperature-anisotropy-driven instabilities in a high-beta laboratory plasma  

NASA Astrophysics Data System (ADS)

The mirror and firehose instabilities are driven unstable in magnetized, high-beta plasmas with anisotropic ion distribution functions. Evidence for the action of these instabilities has been found in space plasmas, in particular solar wind observations [1], and they are thought to be important in a number of astrophysical plasmas (e.g. accretion disks). Studying these important instabilities in the lab requires a high-beta, magnetized plasma and the creation of sufficient temperature anisotropy. We will discuss prospects for laboratory experiments making use of the Enormous Toroidal Plasma Device (ETPD) at UCLA. Firehose-unstable (T? > T?) ion distributions might be driven in plasmas flowing into an expanding magnetic field (similar to the solar wind). Enhanced anisotropy could be provided by the formation of a double layer in the expanding plasma, which leads to the production of ion beams in expanding laboratory plasmas [2]. We will report on: initial experiments in LAPD studying expanding plasmas, measurements of plasma parameters in ETPD and on theoretical projections for acheivable anisotropy and instability thresholds in ETPD. [1] S.D. Bale, et al., PRL 103, 211101 (2009). [2] C. Charles, et al., PoP 11, 1706 (2004).

Carter, T. A.; Dorfman, S. E.; Bardoczi, L.; Geraldini, A.; Robertson, J.; Tang, S.; Tripathi, S.; Vincena, S. T.; Gekelman, W. N.

2013-12-01

230

Mechanical strain- and high glucose-induced alterations in mesangial cell collagen metabolism: role of TGF-beta.  

PubMed

Cultured mesangial cells (MC) exposed to cyclic mechanical strain or high glucose levels increase their secretion of transforming growth factor-beta1 (TGF-beta1) and collagen, suggesting possible mechanisms for the development of diabetic renal sclerosis resulting from intraglomerular hypertension and/or hyperglycemia. This study examines whether glucose interacts with mechanical strain to influence collagen metabolism and whether this change is mediated by TGF-beta. Accordingly, rat MC were grown on flexible-bottom plates in 8 or 35 mM glucose media, subjected to 2 to 5 d of cyclic stretching, and assayed for TGF-beta1 mRNA, TGF-beta1 secretion, and the incorporation of 14C-proline into free or protein-associated hydroxyproline to assess the dynamics of collagen metabolism. Stretching or high glucose exposure increased TGF-beta1 secretion twofold and TGF-beta1 mRNA levels by 30 and 45%, respectively. However, the combination of these stimuli increased secretion greater than fivefold without further elevating mRNA. In 8 mM glucose medium, stretching significantly increased MC collagen synthesis and breakdown, but did not alter accumulation, whereas those stretched in 35 mM glucose markedly increased collagen accumulation. TGF-beta neutralization significantly reduced baseline collagen synthesis, breakdown, and accumulation in low glucose, but had no significant effect on the changes induced by stretch. In contrast, the same treatment of MC in high glucose medium greatly reduced stretch-induced synthesis and breakdown of collagen and totally abolished the increase in collagen accumulation. These results indicate that TGF-beta plays a positive regulatory role in MC collagen synthesis, breakdown, and accumulation. However, in low glucose there is no stretch-induced collagen accumulation, and the effect of TGF-beta is limited to basal collagen turnover. In high glucose media, TGF-beta is a critical mediator of stretch-induced collagen synthesis and catabolism, and, most importantly, its net accumulation. These data have important implications for the pathogenesis and treatment of diabetic glomerulosclerosis. PMID:9596080

Riser, B L; Cortes, P; Yee, J; Sharba, A K; Asano, K; Rodriguez-Barbero, A; Narins, R G

1998-05-01

231

Evaluation of high strength, high conductivity CuNiBe alloys for fusion energy applications  

NASA Astrophysics Data System (ADS)

The unirradiated tensile properties for several different heats and thermomechanical treatment conditions of precipitation strengthened Hycon 3HP CuNiBe (Cu-2%Ni-0.35%Be in wt.%) have been measured over the temperature range of 20-500 C for longitudinal and long transverse orientations. The room temperature electrical conductivity has also been measured for several heats, and the precipitate microstructure was characterized using transmission electron microscopy. The CuNiBe alloys exhibit very good combination of strength and conductivity at room temperature, with yield strengths of 630-725 MPa and electrical conductivities of 65-72% International Annealed Copper Standard (IACS). The strength remained relatively high at all test temperatures, with yield strengths of 420-520 MPa at 500 C. However, low levels of ductility (<5% uniform elongation) were observed at test temperatures above 200-250 C, due to flow localization near grain boundaries (exacerbated by having only 10-20 grains across the gage thickness of the miniaturized sheet tensile specimens). Scanning electron microscopy observation of the fracture surfaces found a transition from ductile transgranular to ductile intergranular fracture with increasing test temperature. Fission neutron irradiation to a dose of ?0.7 displacements per atom (dpa) at temperatures between 100 and 240 C produced a slight increase in strength and a significant decrease in ductility. The measured tensile elongation after irradiation increased with increasing irradiation temperature, with a uniform elongation of ?3.3% observed at 240 C. The electrical conductivity decreased slightly following irradiation, due to the presence of defect clusters and Ni, Zn, Co transmutation products. Considering also previously published fracture toughness data, this indicates that CuNiBe alloys have irradiated tensile and electrical properties comparable or superior to CuCrZr and oxide dispersion strengthened copper at temperatures <250 C, and may be an attractive candidate for certain low-temperature fusion energy structural applications. Conversely, CuNiBe may not be preferred at intermediate temperatures of 250-500 C due to the poor ductility and fracture toughness of CuNiBe alloys at temperatures ?250 C. The potential deformation mechanisms responsible for the transition from transgranular to intergranular fracture are discussed. The possible implications for other precipitation-hardened alloys such as nickel based superalloys are briefly discussed.

Zinkle, S. J.

2014-06-01

232

Evaluation of high strength, high conductivity CuNiBe alloys for fusion energy applications  

SciTech Connect

The unirradiated tensile properties for several different heats and thermomechanical treatment conditions of precipitation strengthened Hycon 3HPTM CuNiBe (Cu-2%Ni-0.35%Be in wt.%) have been measured over the temperature range of 20-500 C for longitudinal and long transverse orientations. The room temperature electrical conductivity has also been measured for several heats, and the precipitate microstructure was characterized using transmission electron microscopy. The CuNiBe alloys exhibit very good combination of strength and conductivity at room temperature, with yield strengths of 630-725 MPa and electrical conductivities of 65-72% International Annealed Copper Standard (IACS). The strength remained relatively high at all test temperatures, with yield strengths of 420-520 MPa at 500 C. However, low levels of ductility (<5% uniform elongation) were observed at test temperatures above 200-250 C, due to flow localization near grain boundaries (exacerbated by having only 10-20 grains across the gage thickness of the miniaturized sheet tensile specimens). Scanning electron microscopy observation of the fracture surfaces found a transition from ductile transgranular to ductile intergranular fracture with increasing test temperature. Fission neutron irradiation to a dose of ~0.7 displacements per atom (dpa) at temperatures between 100 and 240 C produced a slight increase in strength and a significant decrease in ductility. The measured tensile elongation increased with increasing irradiation temperature, with a uniform elongation of ~3.3% observed at 240 C. The electrical conductivity decreased slightly following irradiation, due to the presence of defect clusters and Ni, Zn, Co transmutation products. Considering also previously published fracture toughness data, this indicates that CuNiBe alloys have irradiated tensile and electrical properties comparable or superior to CuCrZr and oxide dispersion strengthened copper at temperatures <250 C, and may be an attractive candidate for certain fusion energy structural applications. Conversely, CuNiBe may not be preferred at intermediate temperatures of 250-500 C due to the poor ductility and fracture toughness of CuNiBe alloys at temperatures >250 C. The potential deformation mechanisms responsible for the transition from transgranular to intergranular fracture are discussed. The possible implications for other precipitation hardened alloys such as nickel based superalloys are briefly discussed.

Zinkle, Steven J [ORNL] [ORNL

2014-01-01

233

Flux conversion and evidence of relaxation in a high-beta plasma formed by high-speed injection into a mirror confinement structure.  

PubMed

High-beta plasmoids can survive the violent dynamics of supersonic reflection off mirror structures, producing a stable high-beta field-reversed configuration (FRC). This shows both the robustness of FRCs and their tendency to assume a preferred plasma state, possibly conforming to a relaxation principle. The key observations are (1) approximate preservation of the magnetic helicity, (2) substantial conversion from toroidal to poloidal magnetic flux, (3) substantial toroidal flow, and (4) a high-beta quiescent final state. These results are from the Translation, Confinement, and Sustainment experiment where a disorganized plasmoid is injected at super-Alfvenic speed into a confinement chamber. After successive reflections from end mirrors, the plasmoid settled into a near-FRC state with high beta and low toroidal magnetic field. The flux conversion and helicity preservation are inferred by an interpretive model. PMID:15245090

Guo, H Y; Hoffman, A L; Miller, K E; Steinhauer, L C

2004-06-18

234

Construction of bioactive chimeric MHC class I tetramer by expression and purification of human-murine chimeric MHC heavy chain and beta(2)m as a fusion protein in Escherichia coli.  

PubMed

Major histocompatibility (MHC) class I tetramers are used in the quantitative analysis of epitope peptide-specific CD8+ T-cells. An MHC class I tetramer was composed of 4 MHC class I complexes and a fluorescently labeled streptavidin (SA) molecule. Each MHC class I complex consists of an MHC heavy chain, a beta(2)-microglobulin (beta(2)m) molecule and a synthetic epitope peptide. In most previous studies, an MHC class I complex was formed in the refolding buffer with an expressed MHC heavy chain molecule and beta(2)m, respectively. This procedure inevitably resulted in the disadvantages of forming unwanted multimers and self-refolding products, and the purification of each kind of monomer was time-consuming. In the present study, the genes of a human/murine chimeric MHC heavy chain (HLA-A2 alpha1, HLA-A2 alpha2 and MHC-H2D alpha3) and beta(2)m were tandem-cloned into plasmid pET17b and expressed as a fusion protein. The recombinant fusion protein was refolded with each of the three HLA-A2 restricted peptides (HBc18-27 FLPSDFFPSI, HBx52-60 HLSLRGLPV, and HBx92-100 VLHKRTLGL) and thus three chimeric MHC class I complexes were obtained. Biotinylation was performed, and its level of efficiency was observed via a band-shift assay in non-reducing polyacrylamide gel electrophoresis (PAGE). Such chimeric MHC class I tetramers showed a sensitive binding activity in monitoring HLA/A2 restrictive cytotoxic T lymphocytes (CTLs) in immunized HLA/A*0201 transgenic mice. PMID:17046278

Ren, Ding; Wang, Fang; He, Xiaowen; Jiang, Lei; Li, Dean; Ying, He; Sun, Shuhan

2006-12-01

235

First direct double-beta decay Q-value measurement of the neutrinoless double-beta decay candidate selenium-82 and development of a high-precision magnetometer  

NASA Astrophysics Data System (ADS)

The results of recent neutrino oscillation experiments indicate that the mass of the neutrino is nonzero. The mass hierarchy and the absolute mass scale of the neutrino, however, are unknown. Furthermore, the nature of the neutrino is also unknown; is it a Dirac or Majorana particle, i.e. is the neutrino its own antiparticle? If experiments succeed in observing neutrinoless double-beta decay, there would be evidence that the neutrino is a Majorana particle and that conservation of total lepton number is violated - a situation forbidden by the Standard Model of particle physics. In support of understanding the nature of the neutrino, the first direct double-beta decay Q-value measurement of the neutrinoless double-beta decay candidate 82Se was performed [D. L. Lincoln et al., Physical Review Letters 110, 012501 (2013)]. The measurement was carried out using Penning trap mass spectrometry, which has proven to be the most precise and accurate method for determining atomic masses and therefore, Q-values. The high-precision measurement resulted in a Q-value with nearly an order of magnitude improvement in precision over the literature value. This result is important for the theoretical interpretations of the observations of current and future double-beta decay studies. It is also important for the design of future and next-generation double-beta decay experiments, such as SuperNEMO, which is planned to observe 100 - 200 kg of 82Se for five years. The high-precision measurement was performed at the Low-Energy Beam and Ion Trap (LEBIT) facility located at the National Superconducting Cyclotron Laboratory (NSCL). The LEBIT facility was the first Penning trap mass spectrometry facility to utilize rare isotope beams produced via fast fragmentation and has measured nearly 40 rare isotopes since its commissioning in 2005. To further improve the LEBIT facility's performance, technical improvements to the system are being implemented. As part of this work, to increase the precision of measurements and to maximize the use of beam time, a high-precision magnetometer was developed. The magnetometer will monitor drifts in the LEBIT facility's 9.4 T superconducting magnet to a relative precision on the order of 1 part in 108. This will eliminate the need to perform reference measurements during an experiment, thus expanding the LEBIT facility's measurement capabilities and scientific output.

Lincoln, David Louis

236

Fiber inline Mach-Zehnder interferometer fabricated by fusion splicing for high temperature sensing  

NASA Astrophysics Data System (ADS)

High temperature detection of micro structure area with high sensitivity has aroused more and more interest recently. A high temperature sensor based on ultra-abrupt tapered fiber Mach-Zehnder interferometer (MZI) is proposed and fabricated by using a fusion-splicing method.The two normal cleaved ends are separated by a distance and become ellipsoidal by one time discharge using a fiber fusion splicer. Then the two ellipsoidal fiber heads contacted between the splicer electrodes are fused together to form the taper. And the other is formed through the same process separated by a distance of L. The thermal characteristic is investigated in 25-1100 C, which temperature limit is highest of tapered fiber MZIs. It is observed that sensitivity varies with temperature ranges, which are 25 pm/C in low-temperature range(25-300C) and 105 pm/C in high-temperature range(300-1100C) respectively. The sensor demonstrates good thermal stability after annealing at 400 C and 800 C for 8 h respectively. The simple ultra-taper based MZI sensor has potential application prospect in the field of high temperature detection, such as the temperature of aeroengine.

Li, Benye; Ni, Shufeng; Cao, Zhitao; Wang, Sumei

2014-12-01

237

Generating High-Brightness Light Ion Beams for Inertial Fusion Energy  

SciTech Connect

Light ion beams may be the best option for an Inertial Fusion Energy (IFE) driver from the standpoint of ei%ciency, standoff, rep-rate operation and cost. This approach uses high-energy-density pulsed power to efficiently accelerate ions in one or two stages at fields of 0.5 to 1.0 GV/m to produce a medium energy (30 MeV), high-current (1 MA) beam of light ions, such as lithium. Ion beams provide the ability for medium distance transport (4 m) of the ions to the target, and standofl of the driver from high- yield implosions. Rep-rate operation of' high current ion sources has ako been demonstrated for industrial applications and couId be applied to IFE. Although (hese factors make light ions the best Iong-teml pulsed- power approach to IFE, light-ion research is being suspended this year in favor of a Z-pinch-driven approach which has the best opport lnity to most-rapidly achieve the U.S. Department of Energy sponsor's goal of high-yield fusion. This paper will summarize the status and most recent results of the light-ion beam program at Sandia National Laboratories (SNL), and document the prospects of light ions for future IFE driver development.

Adams, R.G.; Bailey, J.E.; Cuneno, M.E.; Desjarlais, M.P.; Filuk, A.B.; Hanson, D.L.; Johnson, D.J.; Mehlohorn, T.A.; Menge, P.R.; Olson, C.L.; Pointon, T.D. Slutz, S.A.; Vesey, R.A.; Welch, D.R.; Wenger, D.F.

1998-10-22

238

Recent U.S. advances in ion-beam-driven high energy densityphysics and heavy ion fusion  

SciTech Connect

During the past two years, significant experimental and theoretical progress has been made in the US heavy ion fusion science program in longitudinal beam compression, ion-beam-driven warm dense matter, beam acceleration, high brightness beam transport; and advanced theory and numerical simulations. Innovations in longitudinal compression of intense ion beams by > 50 X propagating through background plasma enable initial beam target experiments in warm dense matter to begin within the next two years. They are assessing how these new techniques might apply to heavy ion fusion drivers for inertial fusion energy.

Logan, B.G.; Bieniosek, F.M.; Celata, C.M.; Coleman, J.; Greenway, W.; Henestroza, E.; Kwan, J.W.; Lee, E.P.; Leitner, M.; Roy,P.K.; Seidl, P.A.; Vay, J-L.; Waldron, W.L.; Yu, S.S.; Barnard, J.J.; Cohen, R.H.; Friedman, A.; Grote, D.P.; Kireeff Covo, M.; Molvik, A.W.; Lund, S.M.; Meier, W.R.; Sharp, W.; Davidson, R.C.; Efthimion, P.C.; Gilson, E.P.; Grisham, L.; Kaganovich, Qin H.; Sefkow, A.B.; Startsev,E.A.; Welch, D.; Olson, C.

2006-07-05

239

Reusing information for high-level fusion: characterizing bias and uncertainty in human-generated intelligence  

NASA Astrophysics Data System (ADS)

To expedite the intelligence collection process, analysts reuse previously collected data. This poses the risk of analysis failure, because these data are biased in ways that the analyst may not know. Thus, these data may be incomplete, inconsistent or incorrect, have structural gaps and limitations, or simply be too old to accurately represent the current state of the world. Incorporating human-generated intelligence within the high-level fusion process enables the integration of hard (physical sensors) and soft information (human observations) to extend the ability of algorithms to associate and merge disparate pieces of information for a more holistic situational awareness picture. However, in order for high-level fusion systems to manage the uncertainty in soft information, a process needs to be developed for characterizing the sources of error and bias specific to human-generated intelligence and assessing the quality of this data. This paper outlines an approach Towards Integration of Data for unBiased Intelligence and Trust (TID-BIT) that implements a novel Hierarchical Bayesian Model for high-level situation modeling that allows the analyst to accurately reuse existing data collected for different intelligence requirements. TID-BIT constructs situational, semantic knowledge graphs that links the information extracted from unstructured sources to intelligence requirements and performs pattern matching over these attributed-network graphs for integrating information. By quantifying the reliability and credibility of human sources, TID-BIT enables the ability to estimate and account for uncertainty and bias that impact the high-level fusion process, resulting in improved situational awareness.

Burke, Dustin; Carlin, Alan; Picciano, Paul; Levchuk, Georgiy; Riordan, Brian

2013-05-01

240

Identification and differential accumulation of two isoforms of the CF1-beta subunit under high light stress in Brassica rapa.  

PubMed

The chloroplast ATP synthase coupling factor CF1 complex contains five nonidentical subunits, alpha, beta, gamma, delta, and epsilon, with a stoichiometry of 3:3:1:1:1. The beta subunit contains the catalytic site for ATP synthesis during photooxidative phosphorylation in the chloroplast. In this study, we have identified two isoforms of the CF1-beta subunit at 56 and 54 kDa in the chloroplast of Brassica rapa, through isolation/purification, proteolytic digestion and internal peptide sequencing. Examining their accumulation pattern demonstrates that both isoforms coexist during chloroplast biogenesis and in mature thylakoid membranes, but the 54 kDa isoform is more apparently upregulated by light or under light stress. LiDS-PAGE shows that the 56 kDa is a major isoform of the CF1-beta subunit under normal light conditions, and its amount was not influenced during high light or other light stress treatments. The 54 kDa isoform is a minor band at normal conditions; however, it significantly increased under excess light stresses, such as high or low light with drought and/or high temperature. Particularly, a ninefold increase was observed after 8-10 h of high light treatment with drought and high temperature. The results suggest that light stress induction of the 54 kDa CF1-beta isoform may present a positive response during chloroplast photoacclimation. PMID:15694282

Jiao, Shunxing; Hilaire, Emmanuel; Guikema, James A

2004-12-01

241

Effect of finite ion gyroradius on the fire-hose instability in a high beta plasma  

NASA Astrophysics Data System (ADS)

In this paper, a generalized kinetic dispersion equation that supports various hydromagnetic waves and instabilities is derived. The general dispersion equation is derived under the usual assumption of hydromagnetic perturbations , but for arbitrary values of the quantity )l.i= (k~ p~/)2/2= (k~ ~A/fl/)2 ~1/,/2 that appears in the dielectric tensor. Here, p~ i refers to the mean ion gyroradius, and B~ i is the perpendicular ion beta. Otherwise, the dispersion equation is fairly general with no additional approximation, such as ignoring certain off-diagonal dielectric tensor elements (which is usually done in the literature) employed. In the subsequent numerical analysis, special attention is paid to the fire-hose instability in a high beta plasma. The numerical results reveal that the conventional treatment of the fire-hose instability (i.e., taking zero ion gyroradius limit at the outset) is not adequate, and that the effect of finite ion gyroradius results in a significant enhancement of the growth rate over a large range of wave numbers.

Yoon, Peter H.; Wu, C. S.; de Assis, A. S.

1993-07-01

242

High Temperature Fusion Reactor Cooling Using Brayton Cycle Based Partial Energy Conversion  

NASA Technical Reports Server (NTRS)

For some future space power systems using high temperature nuclear heat sources most of the output energy will be used in other than electrical form, and only a fraction of the total thermal energy generated will need to be converted to electrical work. The paper describes the conceptual design of such a partial energy conversion system, consisting of a high temperature fusion reactor operating in series with a high temperature radiator and in parallel with dual closed cycle gas turbine (CCGT) power systems, also referred to as closed Brayton cycle (CBC) systems, which are supplied with a fraction of the reactor thermal energy for conversion to electric power. Most of the fusion reactor's output is in the form of charged plasma which is expanded through a magnetic nozzle of the interplanetary propulsion system. Reactor heat energy is ducted to the high temperature series radiator utilizing the electric power generated to drive a helium gas circulation fan. In addition to discussing the thermodynamic aspects of the system design the authors include a brief overview of the gas turbine and fan rotor-dynamics and proposed bearing support technology along with performance characteristics of the three phase AC electric power generator and fan drive motor.

Juhasz, Albert J.; Sawicki, Jerzy T.

2003-01-01

243

High-speed incoming infrared target detection by fusion of spatial and temporal detectors.  

PubMed

This paper presents a method for detecting high-speed incoming targets by the fusion of spatial and temporal detectors to achieve a high detection rate for an active protection system (APS). The incoming targets have different image velocities according to the target-camera geometry. Therefore, single-target detector-based approaches, such as a 1D temporal filter, 2D spatial filter and 3D matched filter, cannot provide a high detection rate with moderate false alarms. The target speed variation was analyzed according to the incoming angle and target velocity. The speed of the distant target at the firing time is almost stationary and increases slowly. The speed varying targets are detected stably by fusing the spatial and temporal filters. The stationary target detector is activated by an almost zero temporal contrast filter (TCF) and identifies targets using a spatial filter called the modified mean subtraction filter (M-MSF). A small motion (sub-pixel velocity) target detector is activated by a small TCF value and finds targets using the same spatial filter. A large motion (pixel-velocity) target detector works when the TCF value is high. The final target detection is terminated by fusing the three detectors based on the threat priority. The experimental results of the various target sequences show that the proposed fusion-based target detector produces the highest detection rate with an acceptable false alarm rate. PMID:25815448

Kim, Sungho

2015-01-01

244

High Temperature Fusion Reactor Cooling Using Brayton Cycle Based Partial Energy Conversion  

NASA Astrophysics Data System (ADS)

For some future space power systems using high temperature nuclear heat sources most of the output energy will be used in other than electrical form, and only a fraction of the total thermal energy generated will need to be converted to electrical work. The paper describes the conceptual design of such a ``partial energy conversion'' system, consisting of a high temperature fusion reactor operating in series with a high temperature radiator and in parallel with dual closed cycle gas turbine (CCGT) power systems, also referred to as closed Brayton cycle (CBC) systems, which are supplied with a fraction of the reactor thermal energy for conversion to electric power. Most of the fusion reactor's output is in the form of charged plasma which is expanded through a magnetic nozzle of the interplanetary propulsion system. Reactor heat energy is ducted to the high temperature series radiator utilizing the electric power generated to drive a helium gas circulation fan. In addition to discussing the thermodynamic aspects of the system design the authors include a brief overview of the gas turbine and fan rotor-dynamics and proposed bearing support technology along with performance characteristics of the three phase AC electric power generator and fan drive motor.

Juhasz, Albert J.; Sawicki, Jerzy T.

2004-02-01

245

Numerical study of the Columbia high-beta device: Torus-II  

SciTech Connect

The ionization, heating and subsequent long-time-scale behavior of the helium plasma in the Columbia fusion device, Torus-II, is studied. The purpose of this work is to perform numerical simulations while maintaining a high level of interaction with experimentalists. The device is operated as a toroidal z-pinch to prepare the gas for heating. This ionization of helium is studied using a zero-dimensional, two-fluid code. It is essentially an energy balance calculation that follows the development of the various charge states of the helium and any impurities (primarily silicon and oxygen) that are present. The code is an atomic physics model of Torus-II. In addition to ionization, we include three-body and radiative recombination processes.

Izzo, R.

1981-01-01

246

Pressure calibration for the cubic press by differential thermal analysis and the high-pressure fusion curve of aluminum  

Microsoft Academic Search

Cell pressures in the cubic press have been determined by means of differential thermal analysis (DTA) based on the known fusion curve of aluminum. The results compared favorably with those of the well-known fixed-point method, based on pressure-induced phase transitions in bismuth (III, 2.55GPa) and thallium (IIIII, 3.68GPa). The high-pressure fusion curve of lead was measured using our calibrated results,

Shanmin Wang; Duanwei He; Wendan Wang; Li Lei

2009-01-01

247

A study on the thermal expansion characteristics of a dissimilar fusion joint by high temperature X-ray diffraction  

Microsoft Academic Search

The lattice thermal expansion behaviour of the constituents of a dissimilar fusion joint between a magnetic iron alloy and Inconel-8211 Inconel is a registered trademark of International Nickel Company. has been investigated by high temperature X-ray diffraction in the temperature range 3001273 K. It is found that the thermal expansivity of the inconel phase in the fusion zone of the

Aritra Banerjee; S. Raju; R. Divakar; E. Mohandas; C. Sudha; A. L. E. Terrance; P. Parameswaran; G. Panneerselvam; M. P. Antony

2006-01-01

248

What role (if any) does the highly conserved CSB-PGBD3 fusion protein play in Cockayne syndrome?  

PubMed Central

The PGBD3 piggyBac transposon inserted into CSB intron 5 early in the primate lineage. As a result of alternative splicing, the human CSB gene now encodes three proteins: CSB, a CSB-PGBD3 fusion protein that joins the N-terminal CSB domain to the C-terminal PGBD3 transposase domain, and PGBD3 transposase. The fusion protein is as highly conserved as CSB, suggesting that it is advantageous in health; however, expression of the fusion protein in CSB-null cells induces a constitutive interferon (IFN) response. The fusion protein binds in vivo to PGBD3-related MER85 elements, but is also tethered to c-Jun, TEAD1, and CTCF motifs by interactions with the cognate transcription factors. The fusion protein regulates nearby genes from the c-Jun (and to a lesser extent TEAD1 and CTCF) motifs, but not from MER85 elements. We speculate that the fusion protein interferes with CSB-dependent chromatin remodeling, generating double-stranded RNA (dsRNA) that induces an IFN response through endosomal TLR or cytoplasmic RIG-I and/or MDA5 RNA sensors. We suggest that the fusion protein was fixed in primates because an elevated IFN response may help to fight viral infection. We also speculate that an inappropriate IFN response may contribute to the clinical presentation of CS. PMID:23369858

Weiner, Alan M.; Gray, Lucas T.

2013-01-01

249

F A T I G U E 2 0 0 2 HIGH-CYCLE FATIGUE OF BETA TITANIUM ALLOYS  

E-print Network

F A T I G U E 2 0 0 2 HIGH-CYCLE FATIGUE OF BETA TITANIUM ALLOYS J. O. Peters*+ , G. Ltjering*, R) properties of the high-strength titanium alloys -Cez and Ti-6246 (in two distinctly different + processed and processed conditions) with the conventional + titanium alloy Ti-6Al-4V (in a + processed condition

Ritchie, Robert

250

Development of high average power DPSSL for laser fusion driver and industrial application  

SciTech Connect

Laser fusion is one of the most feasible approach in the fusion energy development. The goal of inertial fusion energy (IFE) development is to prove that fusion energy can be available to society as electric power source. Recent progress of laser fusion research and development enable the authors to examine technical and economical feasibility, and to plan the realistic strategy and program to the commercial power plant. The most important key issue for IFE is driver technologies. The development of the laser fusion driver may establish new industrial technologies based on the photon processes and is attracting attentions in wide industrial fields.

Nakai, S.; Izawa, Y.; Nakatsuka, M.; Yamanaka, M. [Osaka Univ. (Japan)] [and others

1996-12-31

251

A Petawatt-Laser-Driven, High-Flux Neutron Source for Fusion Micro-Materials Irradiation  

NASA Astrophysics Data System (ADS)

We are examining the application of petawatt lasers to create beam-target fusion neutrons via ponderomotive-driven, electrostatic coupling. This offers a low cost, high-flux, micro 14MeV neutron source for testing tensile strengths of small ( ~100?m) fibers of C, Al_2O_3, SiC, etc., to ~100dpa. Such fibers can form porous fabric tubes for flowing coolant/breeders ( Flibe, LiPb, LiO_2-sand) in a various applications (direct-drive ICF, spheromaks, etc.). Under very short, intense laser heating of a thin tritium-frost layer, ejection of hot (multi-MeV) tail electrons driven by the ponderomotive pressure of the laser field competes with thermal electron heat conduction. Hot ions are ejected from the tritium layer by the resulting potential and move into a deuterium-ice substrate, pre-heated by the hot electrons. Beam-target fusion neutrons are produced at high efficiency (i.e., Q ~0.01-0.1 relative to Q ~0.001 for conventional solid, cold targets), while small target dimensions yield high neutron fluxes. Formal treatment of laser-induced electrostatic potentials is required to accurately model electron/ion transport.

Logan, B. G.; Perkins, L. J.; Ditmire, T.; Rosen, M. D.; Perry, M. D.; Key, M. H.; Diaz de La Rubia, T.; Wolfer, W. G.

1998-11-01

252

High-temperature decomposition of solid solutions of beta-tantalum with copper in films  

NASA Astrophysics Data System (ADS)

Using high-temperature X-ray diffractometry and electron microprobe analysis decomposition of alloys of beta-tantalum with copper produced by codeposition of sputtered ultradisperse particles of tantalum and copper has been established. At a temperature of 900C, the precipitation of copper from the solid solution into an individual phase starts, and its diffusion onto the film surface with the formation of globular particles and simultaneous transition of the matrix ?-modification into ?-tantalum. The suggested mechanism of decomposition of solid solutions includes the following stages: the precipitation of copper into an individual phase, its diffusion onto the surface because of lattice pressure and the concentration gradient inside and outside the tantalum matrix, the coalescence of nanosized formations into drops at the coating surface, and the subsequent evaporation of copper from them in a vacuum.

Tuleushev, Yu. Zh.; Volodin, V. N.; Zhakanbaev, E. A.

2014-05-01

253

Industrial Fabrication of Medium-Beta SCRF Cavities for a High-Intensity Proton Linac  

E-print Network

During 1999, four 700-MHz, medium-beta (b = 0.64), superconducting radio frequency (SCRF) cavities for a high-intensity proton linac project at Los Alamos National Laboratory (LANL) were manufactured by industry. The SCRF cavities were designed by a LANL team in Los Alamos, New Mexico, USA, and manufactured at a CERCA plant in Romans, France. The cavities were made of 4-mm-thick, solid niobium sheets with a residual resistivity ratio (RRR) greater than 250. These niobium sheets were supplied by Wah Chang (USA), Heraeus AG (Germany), and Tokyo Denkai (Japan). The SCRF cavities were shipped to LANL for performance testing. This paper describes the experience gained during the manufacturing process at CERCA.

Kuzminski, J; Gentzlinger, R C; Maccioni, P

2000-01-01

254

Production and characterization of highly purified recombinant thymosin beta 4 in Escherichia coli.  

PubMed

Thymosin ?4 (T?4) is a small peptide composed of 43 amino acids. It has many important biological functions, such as promoting cardiac repair and wound healing, and therefore has great potential in clinical applications. In this report, we describe a novel and efficient way to produce highly purified and active T?4. It was expressed in a soluble form using a DsbA and hexahistindine tag in Escherichia coli (E. coli). Using high cell density cultivation, the final biomass concentration was about 50 g L(-1) dry cell weight with the expression level of the fusion protein being 40%. To obtain highly purified protein, a purification process involving a five-step column procedure was implemented. The purity of T?4 was above 98% and all the host cell related impurities, such as endotoxin, host cell protein and residual DNA levels, were within the permissible range listed in the Chinese Pharmacopoeia. The E-rosette test demonstrated that the bioactivity of purified T?4 was consistent with other published work. This is the first report producing highly purified T?4 from genetically engineered sources. PMID:23711379

Li, Teng; Ma, Su-Yong; Tang, Xiao-Chuang; Nie, Li-Ya; Huang, He

2013-08-01

255

Colliding beam fusion reactor space propulsion system  

Microsoft Academic Search

We describe a space propulsion system based on the Colliding Beam Fusion Reactor (CBFR). The CBFR is a high-beta, field-reversed, magnetic configuration with ion energies in the range of hundreds of keV. Repetitively-pulsed ion beams sustain the plasma distribution and provide current drive. The confinement physics is based on the Vlasov-Maxwell equation, including a Fokker Planck collision operator and all

Frank J. Wessel; Michl W. Binderbauer; Norman Rostoker; Hafiz Ur Rahman; Joseph O'Toole

2000-01-01

256

A target tracking method based on high-resolution radar photoelectronic image data fusion  

NASA Astrophysics Data System (ADS)

A target tracking model and a technique for target tracking filtering based on sequential unscented Kalman filter are presented to improve target tracking performance of high resolution radar/infrared imaging sensor composite guidance system. Firstly, a measurement model for imaging sensor based of the centroid of the target is derived from images. Secondly, a measurement model for radar based of the centroid of the target is derived from traits of high resolution radar. Finally, the data fusion filtering framework for target tracking based on sequential unscented Kalman filter is presented. From the results of simulated experiments, average rate and target tracking accuracy of convergence for the technique developed are superior to those of other techniques. In conclusion, the target tracking model and filtering algorithm developed are proper for high resolution radar/infrared imagery sensor composite guidance system.

Su, Wen-bo; Qi, Lin; Shi, Ze-lin

2014-11-01

257

Large-scale holographic neuron system for multispectral sensor fusion and high-speed signal processing  

NASA Astrophysics Data System (ADS)

One-dimensional (1D) and 2D sensor signals returned from the mass spectrometers, x-ray spectral analyzers, CT scanners, or vapor detectors present a major challenge for the detection and identification of illegal substances. Prompt and accurate identification and classification of detected signatures demands extremely high computation power and requires sophisticated signal processing. The paper presents the development of a real-time multispectral analysis system that performs high-speed neural operations and sensor fusion for feature extraction and trace identification. The system utilizes the technology of large-scale holographic optical neural networks being developed and demonstrated by Physical Optics Corporation (POC). This technology is based on fully parallel optical processing of spectral information to produce parallel spectral pattern recognition. In addition, POC's processing algorithm has demonstrated the ability to extract spectral information from extremely noisy backgrounds. This translates into very high instrument sensitivity.

Lu, Thomas T.; Lin, Freddie S.; Kostrzewski, Andrew A.; Lerner, Jeremy M.

1994-02-01

258

High resolution x-ray imaging microscope for diagnostics of inertial confinement fusion  

NASA Astrophysics Data System (ADS)

X-ray imaging technology is highly developed to meet the needs of high-energy physics and diagnostics of inertial confinement fusion. In this paper, we describe the design of a non coplanar torodal mirrors microscope. It consists of three off-axis revolution concave torodal mirrors working at grazing incidence. Non-periodic W/SiC multilayer coatings have been deposited on each mirror, in order to increase until 10 keV the bandpass of reflectivity of the microscope. These super mirrors have been designed to work at 0.6 grazing incidence angle and display a reflectivity better than 40% in the entire energy range 2-10 keV. Concerning the imaging performances, we have almost achieved 5 ?m of spatial resolution in a field of 500 ?m. Regarding to these results, this prototype of microscope, the so-called "Plasma Imageur X pour les Experiences Laser Mega Joule" (PIXEL), will be used for 2D spatial and 1D time resolved imaging of dense plasmas produced during inertial confinement fusion experiments at the future Laser Mega Joule French facility (LMJ).

Maury, Helene; Troussel, Philippe; Champeaux, J. P.

2009-08-01

259

Investigation of MHD instabilities and control in KSTAR preparing for high beta operation  

NASA Astrophysics Data System (ADS)

Initial H-mode operation of the Korea Superconducting Tokamak Advanced Research (KSTAR) is expanded to higher normalized beta and lower plasma internal inductance moving towards design target operation. As a key supporting device for ITER, an important goal for KSTAR is to produce physics understanding of MHD instabilities at long pulse with steady-state profiles, at high normalized beta, and over a wide range of plasma rotation profiles. An advance from initial plasma operation is a significant increase in plasma stored energy and normalized beta, with Wtot = 340 kJ, ?N = 1.9, which is 75% of the level required to reach the computed ideal n = 1 no-wall stability limit. The internal inductance was lowered to 0.9 at sustained H-mode duration up to 5 s. In ohmically heated plasmas, the plasma current reached 1 MA with prolonged pulse length up to 12 s. Rotating MHD modes are observed in the device with perturbations having tearing rather than ideal parity. Modes with m/n = 3/2 are triggered during the H-mode phase but are relatively weak and do not substantially reduce Wtot. In contrast, 2/1 modes to date only appear when the plasma rotation profiles are lowered after H-L back-transition. Subsequent 2/1 mode locking creates a repetitive collapse of ?N by more than 50%. Onset behaviour suggests the 3/2 mode is close to being neoclassically unstable. A correlation between the 2/1 mode amplitude and local rotation shear from an x-ray imaging crystal spectrometer suggests that the rotation shear at the mode rational surface is stabilizing. As a method to access the ITER-relevant low plasma rotation regime, plasma rotation alteration by n = 1, 2 applied fields and associated neoclassical toroidal viscosity (NTV) induced torque is presently investigated. The net rotation profile change measured by a charge exchange recombination diagnostic with proper compensation of plasma boundary movement shows initial evidence of non-resonant rotation damping by the n = 1, 2 applied field configurations. The result addresses perspective on access to low rotation regimes for MHD instability studies applicable to ITER. Computation of active RWM control using the VALEN-3D code examines control performance using midplane locked mode detection sensors. The LM sensors are found to be strongly affected by mode and control coil-induced vessel current, and consequently lead to limited control performance theoretically.

Park, Y. S.; Sabbagh, S. A.; Bialek, J. M.; Berkery, J. W.; Lee, S. G.; Ko, W. H.; Bak, J. G.; Jeon, Y. M.; Park, J. K.; Kim, J.; Hahn, S. H.; Ahn, J.-W.; Yoon, S. W.; Lee, K. D.; Choi, M. J.; Yun, G. S.; Park, H. K.; You, K.-I.; Bae, Y. S.; Oh, Y. K.; Kim, W.-C.; Kwak, J. G.

2013-08-01

260

Active Resistive Wall Mode Stabilization in Low Rotation, High Beta NSTX Plasmas  

NASA Astrophysics Data System (ADS)

An active feedback system to stabilize the resistive wall mode (RWM) in the National Spherical Torus Experiment (NSTX) is used to maintain plasma stability for greater than 90 RWM growth times. These experiments are the first to demonstrate RWM active stabilization in high beta, low aspect ratio tokamak plasmas with toroidal plasma rotation significantly below the critical rotation profile for passive stability and in the range predicted for ITER. Actively stabilized, low rotation plasmas reached normalized beta of 5.6, and the ratio of normalized beta to the toroidal mode number, n = 1 and 2 ideal no-wall stability limits reached 1.2 and 1.15 respectively, determined by DCON stability analysis of the time-evolving reconstructed experimental equilibria. The significant, controlled reduction of the plasma rotation to less than one percent of the Alfven speed was produced by non-resonant magnetic braking by an applied n = 3 field. The observed plasma rotation damping is in quantitative agreement with neoclassical toroidal viscosity theory including trapped particle effects [1]. The active stabilization system employs a mode control algorithm using RWM sensor input analyzed to distinguish the amplitude and phase of the n = 1 mode. During n = 1 stabilization, the n = 2 mode amplitude increases and surpasses the n = 1 amplitude, but the mode remains stable. By varying the system gain, and relative phase between the measured n = 1 RWM phase and the applied control field, both positive and negative feedback were demonstrated. Contrary to past experience in moderate aspect ratio tokamaks with poloidally continuous stabilizing structure, the RWM can become unstable in certain cases by deforming poloidally, an important consideration for feedback system sensor and control coil design in future devices such as ITER and KSTAR. **In collaboration with R.E. Bell, J.E. Menard, D.A. Gates, A.C. Sontag, J.M. Bialek, B.P. LeBlanc, F.M. Levinton, K. Tritz, H. Yuh. [1] W. Zhu, S.A. Sabbagh, R.E. Bell, et al., Phys. Rev. Lett. 96, 225002 (2006).

Sabbagh, S. A.

2006-10-01

261

Beta-carotene  

MedlinePLUS

... carotene is one of a group of red, orange, and yellow pigments called carotenoids. Beta-carotene and ... of beta-carotene can turn skin yellow or orange. There is growing concern that taking high doses ...

262

D. Moreau IEA W59 Shape and Aspect Ratio Optimization for High Beta, Steady-State Tokamaks, San Diego, February 2005 PLASMA SHAPE, PROFILES AND FLUX CONTROL  

E-print Network

D. Moreau IEA W59 Shape and Aspect Ratio Optimization for High Beta, Steady-State Tokamaks, San JET-EFDA Contributors D. Moreau #12;D. Moreau IEA W59 Shape and Aspect Ratio Optimization for High Conclusion #12;D. Moreau IEA W59 Shape and Aspect Ratio Optimization for High Beta, Steady-State Tokamaks

263

Onset of hydrodynamic mix in high-velocity, highly compressed inertial confinement fusion implosions.  

PubMed

Deuterium-tritium inertial confinement fusion implosion experiments on the National Ignition Facility have demonstrated yields ranging from 0.8 to 710(14), and record fuel areal densities of 0.7 to 1.3 g/cm2. These implosions use hohlraums irradiated with shaped laser pulses of 1.5-1.9 MJ energy. The laser peak power and duration at peak power were varied, as were the capsule ablator dopant concentrations and shell thicknesses. We quantify the level of hydrodynamic instability mix of the ablator into the hot spot from the measured elevated absolute x-ray emission of the hot spot. We observe that DT neutron yield and ion temperature decrease abruptly as the hot spot mix mass increases above several hundred ng. The comparison with radiation-hydrodynamic modeling indicates that low mode asymmetries and increased ablator surface perturbations may be responsible for the current performance. PMID:24010449

Ma, T; Patel, P K; Izumi, N; Springer, P T; Key, M H; Atherton, L J; Benedetti, L R; Bradley, D K; Callahan, D A; Celliers, P M; Cerjan, C J; Clark, D S; Dewald, E L; Dixit, S N; Dppner, T; Edgell, D H; Epstein, R; Glenn, S; Grim, G; Haan, S W; Hammel, B A; Hicks, D; Hsing, W W; Jones, O S; Khan, S F; Kilkenny, J D; Kline, J L; Kyrala, G A; Landen, O L; Le Pape, S; MacGowan, B J; Mackinnon, A J; MacPhee, A G; Meezan, N B; Moody, J D; Pak, A; Parham, T; Park, H-S; Ralph, J E; Regan, S P; Remington, B A; Robey, H F; Ross, J S; Spears, B K; Smalyuk, V; Suter, L J; Tommasini, R; Town, R P; Weber, S V; Lindl, J D; Edwards, M J; Glenzer, S H; Moses, E I

2013-08-23

264

Onset of Hydrodynamic Mix in High-Velocity, Highly Compressed Inertial Confinement Fusion Implosions  

NASA Astrophysics Data System (ADS)

Deuterium-tritium inertial confinement fusion implosion experiments on the National Ignition Facility have demonstrated yields ranging from 0.8 to 71014, and record fuel areal densities of 0.7 to 1.3g/cm2. These implosions use hohlraums irradiated with shaped laser pulses of 1.5-1.9 MJ energy. The laser peak power and duration at peak power were varied, as were the capsule ablator dopant concentrations and shell thicknesses. We quantify the level of hydrodynamic instability mix of the ablator into the hot spot from the measured elevated absolute x-ray emission of the hot spot. We observe that DT neutron yield and ion temperature decrease abruptly as the hot spot mix mass increases above several hundred ng. The comparison with radiation-hydrodynamic modeling indicates that low mode asymmetries and increased ablator surface perturbations may be responsible for the current performance.

Ma, T.; Patel, P. K.; Izumi, N.; Springer, P. T.; Key, M. H.; Atherton, L. J.; Benedetti, L. R.; Bradley, D. K.; Callahan, D. A.; Celliers, P. M.; Cerjan, C. J.; Clark, D. S.; Dewald, E. L.; Dixit, S. N.; Dppner, T.; Edgell, D. H.; Epstein, R.; Glenn, S.; Grim, G.; Haan, S. W.; Hammel, B. A.; Hicks, D.; Hsing, W. W.; Jones, O. S.; Khan, S. F.; Kilkenny, J. D.; Kline, J. L.; Kyrala, G. A.; Landen, O. L.; Le Pape, S.; MacGowan, B. J.; Mackinnon, A. J.; MacPhee, A. G.; Meezan, N. B.; Moody, J. D.; Pak, A.; Parham, T.; Park, H.-S.; Ralph, J. E.; Regan, S. P.; Remington, B. A.; Robey, H. F.; Ross, J. S.; Spears, B. K.; Smalyuk, V.; Suter, L. J.; Tommasini, R.; Town, R. P.; Weber, S. V.; Lindl, J. D.; Edwards, M. J.; Glenzer, S. H.; Moses, E. I.

2013-08-01

265

Reaching High-Yield Fusion with a Slow Plasma Liner Compressing a Magnetized Target  

SciTech Connect

Dynamics of the compression of a magnetized plasma target by a heavy liner made of partially ionized high high-Z material is discussed. A 'soft-landing' (shockless) mode of the liner deceleration is analyzed. Conclusion is drawn that such mode is possible for the liners whose thickness at the time of the first contact with the target is smaller than, roughly, 10% of the initial (un-compressed) target radius. A combination of the plasma liner with one or two glide cones allows for a direct access to the area near the center of the reactor chamber. One can then generate plasma target inside the plasma liner at the optimum time. The other advantage of the glide cones is that they can be used to deliver additional fuel to the center of the target near the point of a maximum compression and thereby increase the fusion yield.

Ryutov, D D; Parks, P B

2008-03-18

266

High dynamic range imaging on mobile devices using fusion of multiexposure images  

NASA Astrophysics Data System (ADS)

Because the real world scenes have a high dynamic range which exceeds the range of the imaging devices, the captured images sometimes contain under-exposed and saturated regions. In this paper, we propose a simple but effective method to achieve high dynamic range (HDR) rendering results from three multiexposure images comprising under-, normal-, and over-exposure. First, we generate the weight function, for the fusion of multiexposure images, according to the brightness. Then, we employ the bilateral filter-based retouching to enhance image details, especially in the dark regions. Experimental results demonstrate that the proposed method produces clear details in images and achieves natural HDR rendering results on mobile imaging devices.

Jung, Cheolkon; Yang, Yanru; Jiao, Licheng

2013-10-01

267

Use of Polycarbonate Vacuum Vessels in High-Temperature Fusion-Plasma Research  

SciTech Connect

Magnetic fusion energy (MFE) research requires ultrahigh-vacuum (UHV) conditions, primarily to reduce plasma contamination by impurities. For radiofrequency (RF)-heated plasmas, a great benefit may accrue from a non-conducting vacuum vessel, allowing external RF antennas which avoids the complications and cost of internal antennas and high-voltage high-current feedthroughs. In this paper we describe these and other criteria, e.g., safety, availability, design flexibility, structural integrity, access, outgassing, transparency, and fabrication techniques that led to the selection and use of 25.4-cm OD, 1.6-cm wall polycarbonate pipe as the main vacuum vessel for an MFE research device whose plasmas are expected to reach keV energies for durations exceeding 0.1 s

B. Berlinger, A. Brooks, H. Feder, J. Gumbas, T. Franckowiak and S.A. Cohen

2012-09-27

268

Development of high power long-pulse RF transmitter for ICRF heating in fusion researches and cyclotron accelerator  

Microsoft Academic Search

A high power long pulse transmitter whose frequency range is in the range of VHF(Very High Frequency) bands have been widely used for fusion researches and accelerator as well as broadcasting industry. KAERI (Korea Atomic Energy Research Institute) have been developing the transmitters for ICRF heating for KSTAR and the cyclotron accelerator since 1996. The toroidal magnetic field of KSTAR

J. G. Kwak; S. J. Wang; Y. D. Bae; S. H. Kim; C. K. Hwang; S. Moriyama

2011-01-01

269

Progress in laboratory high gain ICF (inertial confinement fusion): Prospects for the future  

SciTech Connect

Inertial confinement fusion (ICF), a thermonuclear reaction in a small (/approximately/5 mm diameter) fuel capsule filled with a few milligrams of deuterium and tritium, has been the subject of very fruitful experimentation since the early 1970's. High gain ICF is now on the threshold of practical applications. With a Laboratory Microfusion Facility (LMF), these applications will have major implications for national defense, basic and applied science, and power production. With a driver capable of delivering about 10 MJ in a 10-ns pulse at an intensity of /approximately/3 /times/ 10/sup 14/ W/cm/sup 2/, an appropriately configured cryogenic capsule could be compressed to a density of about 200 g/cm/sup 3/ and a temperature of 3--5 keV. Under these conditions, up to 10 mg of DT could be ignited, and with a burn efficiency of about 30%, release up to 1000 MJ of fusion energy, an energy gain of about 100. A thousand megajoules is equivalent to about one quarter ton of TNT, or about 7 gallons of oil--an amount of energy tractable under laboratory conditions and potentially very useful for a variety of applications. 61 refs., 33 figs.

Storm, E.; Lindl, J.D.; Campbell, E.M.; Bernat, T.P.; Coleman, L.W.; Emmett, J.L.; Hogan, W.J.; Hunt, J.T.; Krupke, W.F.; Lowdermilk, W.H.

1988-01-01

270

Application of spatially resolved high resolution crystal spectrometry to inertial confinement fusion plasmasa)  

NASA Astrophysics Data System (ADS)

High resolution (?/?? 10 000) 1D imaging x-ray spectroscopy using a spherically bent crystal and a 2D hybrid pixel array detector is used world wide for Doppler measurements of ion-temperature and plasma flow-velocity profiles in magnetic confinement fusion plasmas. Meter sized plasmas are diagnosed with cm spatial resolution and 10 ms time resolution. This concept can also be used as a diagnostic of small sources, such as inertial confinement fusion plasmas and targets on x-ray light source beam lines, with spatial resolution of micrometers, as demonstrated by laboratory experiments using a 250-?m 55Fe source, and by ray-tracing calculations. Throughput calculations agree with measurements, and predict detector counts in the range 10-8-10-6 times source x-rays, depending on crystal reflectivity and spectrometer geometry. Results of the lab demonstrations, application of the technique to the National Ignition Facility (NIF), and predictions of performance on NIF will be presented.

Hill, K. W.; Bitter, M.; Delgado-Aparacio, L.; Pablant, N. A.; Beiersdorfer, P.; Schneider, M.; Widmann, K.; Sanchez del Rio, M.; Zhang, L.

2012-10-01

271

Application of spatially resolved high resolution crystal spectrometry to inertial confinement fusion plasmas  

SciTech Connect

High resolution ({lambda}/{Delta}{lambda}{approx} 10 000) 1D imaging x-ray spectroscopy using a spherically bent crystal and a 2D hybrid pixel array detector is used world wide for Doppler measurements of ion-temperature and plasma flow-velocity profiles in magnetic confinement fusion plasmas. Meter sized plasmas are diagnosed with cm spatial resolution and 10 ms time resolution. This concept can also be used as a diagnostic of small sources, such as inertial confinement fusion plasmas and targets on x-ray light source beam lines, with spatial resolution of micrometers, as demonstrated by laboratory experiments using a 250-{mu}m {sup 55}Fe source, and by ray-tracing calculations. Throughput calculations agree with measurements, and predict detector counts in the range 10{sup -8}-10{sup -6} times source x-rays, depending on crystal reflectivity and spectrometer geometry. Results of the lab demonstrations, application of the technique to the National Ignition Facility (NIF), and predictions of performance on NIF will be presented.

Hill, K. W.; Bitter, M.; Delgado-Aparacio, L.; Pablant, N. A. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Beiersdorfer, P.; Schneider, M.; Widmann, K. [Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Sanchez del Rio, M. [European Synchrotron Radiation Facility, BP 220, 38043-Grenoble Cedex (France); Zhang, L. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

2012-10-15

272

Simulations of neutrino oscillations with a high-energy beta beam from CERN to LENA at Pyhasalmi Mine  

E-print Network

I consider a high-Q beta beam peaking at multi-GeV energy for the baseline CERN-Pyh\\"asalmi, with the length of 2288 km, using LENA, a 50 kton liquid scintillator as the far detector. The beta beam is assumed to be accompanied by a conventional wide band beam of 1--6 GeV. This combination turns out to be very powerful to measure neutrino parameters if $\\sin^2 2\\theta_{13}\\sim (1...3)\\cdot 10^{-3}$.

Juha Peltoniemi

2009-11-27

273

Ba-ion extraction from a high pressure Xe gas for double-beta decay studies with EXO  

E-print Network

An experimental setup is being developed to extract Ba ions from a high-pressure Xe gas environment. It aims to transport Ba ions from 10 bar Xe to vacuum conditions. The setup utilizes a converging-diverging nozzle in combination with a radio-frequency (RF) funnel to move Ba ions into vacuum through the pressure drop of several orders of magnitude. This technique is intended to be used in a future multi-ton detector investigating double-beta decay in $^{136}$Xe. Efficient extraction and detection of Ba ions, the decay product of Xe, would allow for a background-free measurement of the $^{136}$Xe double-beta decay.

T. Brunner; D. Fudenberg; A. Sabourov; V. L. Varentsov; G. Gratta; D. Sinclair; for the EXO collaboration

2013-02-27

274

Theoretical and experimental studies of high-beta plasmas formed by odd-parity rotating magnetic fields  

NASA Astrophysics Data System (ADS)

Hamiltonian simulations of ion and electron heating by odd-parity rotating magnetic fields applied to FRC plasmas have predicted rapid heating of both electrons and ions to multi-keV temperatures, even at low relative RMF strengths. Both the onset of heating and saturation of energy have been explained by perturbation analysis in stochastic theory. These simulations assumed full RMF penetration to the major axis and collisionless particle trajectories, the latter expected in fusion reactor. However, most present RMF/FRC experiments do not achieve full RMF penetration and operate in a low-temperature collisional regime, far from fusion-reactor conditions. Recent experiments at Princeton, which employ commercial off-the-shelf hardware and non-invasive diagnostics and which use, for the first time in FRC research, remote divertor chambers, have achieved a thousand-fold reduction in collisionality to below 0.001, volume-averaged beta above 0.5, electron temperatures above 200 eV, and full penetration of the RMF while avoiding the radiation barrier encountered by other RMF/FRC experiments. Comparisons between theory and experiment show the important role of infrequent collisions, particularly with neutrals. Motivations for a superconducting next-step FRC and design considerations for a car-sized practical FRC reactor will be described.

Cohen, Samuel

2007-11-01

275

High-sensitive determination of coenzyme Q(10) in iodinate-beta-cyclodextrin medium by inclusion reaction and catalytic polarography.  

PubMed

A novel polarographic method for the determination of coenzyme Q(10) in beta-cyclodextrin (beta-CD) and iodinate system is proposed. The stability of coenzyme Q(10) to light was improved by the formation of coenzyme Q(10)-beta-CD inclusion complex. In addition, the sensitivity for the determination of coenzyme Q(10) was enhanced by both the formation and the polarographic catalytic wave of the inclusion complex in the presence of iodinate. In 0.1 mol/L HAc-NaAc (pH 4.7)-5.0 x 10(-5) mol/L beta-CD-1.2 x 10(-3) mol/L potassium iodinate-ethanol/water (60:40, v/v) medium, coenzyme Q(10)-beta-CD inclusion complex yielded a sensitive association/parallel catalytic wave. The second-order derivative peak current of the catalytic wave was proportional to coenzyme Q(10) concentration in the range of 6.0 x 10(-8)-2.5 x 10(-7) mol/L, and the detection limit was 1.0 x 10(-8) mol/L. The proposed method has high analytical sensitivity and is allowed to determine coenzyme Q(10) under light. PMID:16289441

Yang, Hai-Ying; Song, Jun-Feng

2006-01-01

276

Isolation of Enterobacter aerogenes susceptible to beta-lactam antibiotics despite high level beta-lactamase production  

Microsoft Academic Search

This report describes a patient with nosocomial meningitis from whom four distinct isolates ofEnterobacter aerogenes were recovered over a complicated course of chemotherapy. The initial isolate was susceptible to expanded spectrum ?-lactams despite constitutive production of high levels of ?-lactamase. Resistant isolates recovered during antibiotic therapy had lost a 42,000 outer membrane protein. These data suggest that b-lactam susceptibility in

M. A. Mellencamp; J. S. Roccaforte; L. C. Preheim; C. C. Sanders; C. A. Anene; M. J. Bittner

1990-01-01

277

A High-Beta, Supersonic Plasma Flow and Shock Formation in Magnetic Channels  

NASA Astrophysics Data System (ADS)

Plasma acceleration and shock wave formation are investigated in the HITOP device of Tohoku University. A high-beta(>50%), and highly-ionized(>50%), flowing He-plasma is produced quasi-steadily(1ms) by an MPD arc jet and is injected into a cylindrical vacuum chamber (diameter: 0.8m, length: 3.3m) along various axial magnetic channels. Axial profiles of an ion acoustic Mach number Mi are measured by a Mach probe and a spectroscopic method. It is found that Mi is almost unity in a uniform magnetic field and Mi increases up to 3 in a diverging magnetic field. When a magnetic bump is added in the diverging field, a shock wave with a sudden decrease in Mi and increase in density is observed near the inlet of the bump region. The subsonic plasma flow is re-accelerated in the converging field. Mi attains to unity near the magnetic throat and increases up to 3 in the diverging region. The bump field works as a magnetic Laval nozzle. These phenomena are quite similar to those in a compressible gas flow through a conventional Laval nozzle.

Inutake, Masaaki; Ando, Akira; Hattori, Kunihiko; Yoshinuma, Mikirou; Imasaki, Atsushi; Yagai, Tsuyoshi; Tobari, Hiroyuki; Murakami, Fumitake; Ashino, Masashi

2000-10-01

278

The Cytotoxic Role of Intermittent High Glucose on Apoptosis and Cell Viability in Pancreatic Beta Cells  

PubMed Central

Objectives. Glucose fluctuations are both strong predictor of diabetic complications and crucial factor for beta cell damages. Here we investigated the effect of intermittent high glucose (IHG) on both cell apoptosis and proliferation activity in INS-1 cells and the potential mechanisms. Methods. Cells were treated with normal glucose (5.5?mmol/L), constant high glucose (CHG) (25?mmol/L), and IHG (rotation per 24?h in 11.1 or 25?mmol/L) for 7 days. Reactive oxygen species (ROS), xanthine oxidase (XOD) level, apoptosis, cell viability, cell cycle, and expression of cyclinD1, p21, p27, and Skp2 were determined. Results. We found that IHG induced more significant apoptosis than CHG and normal glucose; intracellular ROS and XOD levels were more markedly increased in cells exposed to IHG. Cells treated with IHG showed significant decreased cell viability and increased cell proportion in G0/G1 phase. Cell cycle related proteins such as cyclinD1 and Skp2 were decreased significantly, but expressions of p27 and p21 were increased markedly. Conclusions. This study suggested that IHG plays a more toxic effect including both apoptosis-inducing and antiproliferative effects on INS-1 cells. Excessive activation of cellular stress and regulation of cyclins might be potential mechanism of impairment in INS-1 cells induced by IHG. PMID:24772447

Zhang, Zhen; Li, Jing; Yang, Lei; Chen, Rongping; Yang, Rui; Zhang, Hua; Cai, Dehong; Chen, Hong

2014-01-01

279

High$beta$ capture and mirror confinement of laser-produced plasmas. Semiannual report, February 1July 31, 1973  

Microsoft Academic Search

The United Aircraft Research Laboratories are engaged in a program to ; investigate the use of a dense, mirror-confined, laser-produced plasma as the ; target for a neutral-injection beam and to examine this technique for ; establishing and maintaining a high-temperature, high-density, steady-state, ; mirrorconfined fusion plasma. The program is a direct extension of the current ; UARL investigations of

A. F. Haught; D. H. Polk; J. T. Woo; W. J. Fader; R. G. Tomlinson; R. A. Jong; W. B. Ard

1973-01-01

280

A high-throughput chemical screen reveals that harmine-mediated inhibition of DYRK1A increases human pancreatic beta cell replication.  

PubMed

Types 1 and 2 diabetes affect some 380 million people worldwide. Both ultimately result from a deficiency of functional pancreatic insulin-producing beta cells. Beta cells proliferate in humans during a brief temporal window beginning around the time of birth, with a peak percentage (?2%) engaged in the cell cycle in the first year of life. In embryonic life and after early childhood, beta cell replication is barely detectable. Whereas beta cell expansion seems an obvious therapeutic approach to beta cell deficiency, adult human beta cells have proven recalcitrant to such efforts. Hence, there remains an urgent need for antidiabetic therapeutic agents that can induce regeneration and expansion of adult human beta cells in vivo or ex vivo. Here, using a high-throughput small-molecule screen (HTS), we find that analogs of the small molecule harmine function as a new class of human beta cell mitogenic compounds. We also define dual-specificity tyrosine-regulated kinase-1a (DYRK1A) as the likely target of harmine and the nuclear factors of activated T cells (NFAT) family of transcription factors as likely mediators of human beta cell proliferation and differentiation. Using three different mouse and human islet in vivo-based models, we show that harmine is able to induce beta cell proliferation, increase islet mass and improve glycemic control. These observations suggest that harmine analogs may have unique therapeutic promise for human diabetes therapy. Enhancing the potency and beta cell specificity of these compounds are important future challenges. PMID:25751815

Wang, Peng; Alvarez-Perez, Juan-Carlos; Felsenfeld, Dan P; Liu, Hongtao; Sivendran, Sharmila; Bender, Aaron; Kumar, Anil; Sanchez, Roberto; Scott, Donald K; Garcia-Ocaa, Adolfo; Stewart, Andrew F

2015-04-01

281

ChemTeacher: Fusion  

NSDL National Science Digital Library

ChemTeacher compiles background information, videos, articles, demonstrations, worksheets and activities for high school teachers to use in their classrooms. The Fusion page includes resources for teaching students about the discovery and applications of fusion.

2012-07-24

282

High divergence in primate-specific duplicated regions: Human and chimpanzee Chorionic Gonadotropin Beta genes  

PubMed Central

Background Low nucleotide divergence between human and chimpanzee does not sufficiently explain the species-specific morphological, physiological and behavioral traits. As gene duplication is a major prerequisite for the emergence of new genes and novel biological processes, comparative studies of human and chimpanzee duplicated genes may assist in understanding the mechanisms behind primate evolution. We addressed the divergence between human and chimpanzee duplicated genomic regions by using Luteinizing Hormone Beta (LHB)/Chorionic Gonadotropin Beta (CGB) gene cluster as a model. The placental CGB genes that are essential for implantation have evolved from an ancestral pituitary LHB gene by duplications in the primate lineage. Results We shotgun sequenced and compared the human (45,165 bp) and chimpanzee (39,876 bp) LHB/CGB regions and hereby present evidence for structural variation resulting in discordant number of CGB genes (6 in human, 5 in chimpanzee). The scenario of species-specific parallel duplications was supported (i) as the most parsimonious solution requiring the least rearrangement events to explain the interspecies structural differences; (ii) by the phylogenetic trees constructed with fragments of intergenic regions; (iii) by the sequence similarity calculations. Across the orthologous regions of LHB/CGB cluster, substitutions and indels contributed approximately equally to the interspecies divergence and the distribution of nucleotide identity was correlated with the regional repeat content. Intraspecies gene conversion may have shaped the LHB/CGB gene cluster. The substitution divergence (1.82.59%) exceeded two-three fold the estimates for single-copy loci and the fraction of transversional mutations was increased compared to the unique sequences (43% versus ~30%). Despite the high sequence identity among LHB/CGB genes, there are signs of functional differentiation among the gene copies. Estimates for dn/ds rate ratio suggested a purifying selection on LHB and CGB8, and a positive evolution of CGB1. Conclusion If generalized, our data suggests that in addition to species-specific deletions and duplications, parallel duplication events may have contributed to genetic differences separating humans from their closest relatives. Compared to unique genomic segments, duplicated regions are characterized by high divergence promoted by intraspecies gene conversion and species-specific chromosomal rearrangements, including the alterations in gene copy number. PMID:18606016

2008-01-01

283

J.E. Menard -IEA Workshop 59 -Shape and Aspect Ratio Optimization for High Beta, Steady-State Tokamaks 1 Ideal MHD stability scaling with  

E-print Network

J.E. Menard - IEA Workshop 59 - Shape and Aspect Ratio Optimization for High Beta, Steady Physics Laboratory IEA Workshop 59 February 14, 2005 General Atomics - San Diego, CA #12;J.E. Menard - IEA, February 2003 #12;J.E. Menard - IEA Workshop 59 - Shape and Aspect Ratio Optimization for High Beta, Steady

284

The Role of Strong Coupling in Z-Pinch-Driven Approaches to High Yield Inertial Confinement Fusion  

Microsoft Academic Search

Peak x-ray powers as high as 280 {+-} 40 TW have been generated from the implosion of tungsten wire arrays on the Z Accelerator at Sandia National Laboratories. The high x-ray powers radiated by these z-pinches provide an attractive new driver option for high yield inertial confinement fusion (ICF). The high x-ray powers appear to be a result of using

THOMAS A. MEHLHORN; MICHAEL P. DESJARLAIS; THOMAS A. HAILL; JOEL S. LASH; STEPHEN E. ROSENTHAL; STEPHEN A. SLUTZ; PETER H. STOLTZ; ROGER A. VESEY; B. OLIVER

1999-01-01

285

High resolution image acquisition from magnetic resonance and computed tomography scans using the curvelet fusion algorithm with inverse interpolation techniques.  

PubMed

We present a new approach, based on the curvelet transform, for the fusion of magnetic resonance and computed tomography images. The objective of this fusion process is to obtain images, with as much detail as possible, for medical diagnosis. This approach is based on the application of the additive wavelet transform on both images and the segmentation of their detail planes into small overlapping tiles. The ridgelet transform is then applied on each of these tiles, and the fusion process is performed on the ridgelet transforms of the tiles. To maximize the benefit of the fused images, inverse interpolation techniques are used to obtain high resolution images from the low resolution fused images. Three inverse interpolation techniques are presented and compared. Simulation results show the superiority of the proposed curvelet fusion approach to the traditional discrete wavelet transform fusion technique. Results also reveal that inverse interpolation techniques have succeeded in obtaining high resolution images from the fused images with better quality than that of the traditional cubic spline interpolation technique. PMID:20062497

Ali, Fatma E; El-Dokany, Ibrahim M; Saad, Abdelfattah A; Al-Nuaimy, Waleed; Abd El-Samie, Fathi E

2010-01-01

286

Direct Drive Heavy-Ion-Beam Inertial Fusion at High Coupling Efficiency  

SciTech Connect

Issues with coupling efficiency, beam illumination symmetry and Rayleigh Taylor (RT) instability are discussed for spherical heavy-ion-beam-driven targets with and without hohlraums. Efficient coupling of heavy ion beams to compress direct-drive inertial fusion targets without hohlraums is found to require ion range increasing several-fold during the drive pulse. One-dimensional implosion calculations using the LASNEX ICF target physics code shows the ion range increasing four-fold during the drive pulse to keep ion energy deposition following closely behind the imploding ablation front, resulting in high coupling efficiencies (shell kinetic energy/incident beam energy of 16 to 18%). Ways to increase beam ion range while mitigating Rayleigh-Taylor instabilities are discussed for future work.

Logan, B. Grant; Logan, B. Grant; Perkins, L.J.; Barnard, J.J.

2007-06-25

287

Development of high power radio frequency components for fusion plasma heating. Final report, Revision 3  

SciTech Connect

The purpose of this CRADA was to develop advanced microwave heating systems for both ion cyclotron heating and electron cyclotron heating for magnetic fusion reactors. This involved low-frequency (UHF), high-power (millimeter-wave) microwave components, such as antennas, windows, and matching elements. This CRADA also involved developing conceptual designs for new microwave sources. General Atomics built and tested the distributed cooled window and provided LLNL with transmission and reflection test data in order to then benchmark the EM computer codes. The combline antenna built and analyzed by LLNL was based on a GA design. GA provided LLNL with a number of niobium plates for hot pressing and provided the necessary guidance to allow successful bonding. GA representatives were on site at LLNL on numerous occasions to consult and give guidance on the ferroelectric tuner, combline antenna and distributed window analysis.

NONE

1997-09-11

288

High-level production of human interleukin-10 fusions in tobacco cell suspension cultures  

PubMed Central

The production of pharmaceutical proteins in plants has made much progress in recent years with the development of transient expression systems, transplastomic technology and humanizing glycosylation patterns in plants. However, the first therapeutic proteins approved for administration to humans and animals were made in plant cell suspensions for reasons of containment, rapid scale-up and lack of toxic contaminants. In this study, we have investigated the production of human interleukin-10 (IL-10) in tobacco BY-2 cell suspension and evaluated the effect of an elastin-like polypeptide tag (ELP) and a green fluorescent protein (GFP) tag on IL-10 accumulation. We report the highest accumulation levels of hIL-10 obtained with any stable plant expression system using the ELP fusion strategy. Although IL-10-ELP has cytokine activity, its activity is reduced compared to unfused IL-10, likely caused by interference of ELP with folding of IL-10. Green fluorescent protein has no effect on IL-10 accumulation, but examining the trafficking of IL-10-GFP over the cell culture cycle revealed fluorescence in the vacuole during the stationary phase of the culture growth cycle. Analysis of isolated vacuoles indicated that GFP alone is found in vacuoles, while the full-size fusion remains in the whole-cell extract. This indicates that GFP is cleaved off prior to its trafficking to the vacuole. On the other hand, IL-10-GFP-ELP remains mostly in the ER and accumulates to high levels. Protein bodies were observed at the end of the culture cycle and are thought to arise as a consequence of high levels of accumulation in the ER. PMID:23297698

Kaldis, Angelo; Ahmad, Adil; Reid, Alexandra; McGarvey, Brian; Brandle, Jim; Ma, Shengwu; Jevnikar, Anthony; Kohalmi, Susanne E; Menassa, Rima

2013-01-01

289

PPPL-3245 -Preprint: April 1997, UC-420 A fusion power plant without plasma-material interactions  

E-print Network

. It is based on driven p-11B fusion in a high-beta closed- field device, the field-reversed configuration (FRC in p-11B. This solution requires that a high-, closed-B confinement device, the field-reversed show higher gains, Q > 4, are possible, particularly if colliding polarized flows of superthermal fuel

290

Low or High Fractionation Dose {beta}-Radiotherapy for Pterygium? A Randomized Clinical Trial  

SciTech Connect

Purpose: Postoperative adjuvant treatment using {beta}-radiotherapy (RT) is a proven technique for reducing the recurrence of pterygium. A randomized trial was conducted to determine whether a low fractionation dose of 2 Gy within 10 fractions would provide local control similar to that after a high fractionation dose of 5 Gy within 7 fractions for surgically resected pterygium. Methods: A randomized trial was conducted in 200 patients (216 pterygia) between February 2006 and July 2007. Only patients with fresh pterygium resected using a bare sclera method and given RT within 3 days were included. Postoperative RT was delivered using a strontium-90 eye applicator. The pterygia were randomly treated using either 5 Gy within 7 fractions (Group 1) or 2 Gy within 10 fractions (Group 2). The local control rate was calculated from the date of surgery. Results: Of the 216 pterygia included, 112 were allocated to Group 1 and 104 to Group 2. The 3-year local control rate for Groups 1 and 2 was 93.8% and 92.3%, respectively (p = .616). A statistically significant difference for cosmetic effect (p = .034), photophobia (p = .02), irritation (p = .001), and scleromalacia (p = .017) was noted in favor of Group 2. Conclusions: No better local control rate for postoperative pterygium was obtained using high-dose fractionation vs. low-dose fractionation. However, a low-dose fractionation schedule produced better cosmetic effects and resulted in fewer symptoms than high-dose fractionation. Moreover, pterygia can be safely treated in terms of local recurrence using RT schedules with a biologic effective dose of 24-52.5 Gy{sub 10.}.

Viani, Gustavo Arruda, E-mail: gusviani@gmail.com [Department of Radiation Oncology, Marilia Medicine School, Sao Paulo, SP (Brazil); De Fendi, Ligia Issa; Fonseca, Ellen Carrara [Department of Ophthalmology, Marilia Medicine School, Sao Paulo, SP (Brazil); Stefano, Eduardo Jose [Department of Radiation Oncology, Marilia Medicine School, Sao Paulo, SP (Brazil)

2012-02-01

291

Enantiomeric separation of norgestrel by reversed phase high-performance liquid chromatography using eluents containing hydroxypropyl-beta-cyclodextrin in stereoselective skin permeation study  

Microsoft Academic Search

The chiral separation of norgestrel enantiomers using reversed-phase high-performance liquid chromatography (RP-HPLC) was studied with hydroxypropyl-beta-cyclodextrin (HP-beta-CD) as chiral mobile phase additive. The effect of mobile phase composition, concentration of HP-beta-CD and column temperature on enantioselective separation were investigated. The quantification properties of the developed RP-HPLC method were examined. A baseline separation of norgestrel enantiomers was achieved on a Agilent

Jincui Ye; Guosheng Chen; Su Zeng

2006-01-01

292

Aqueous environmental crack propagation in high-strength beta titanium alloys  

Microsoft Academic Search

The aqueous environment-assisted cracking (EAC) behavior of two peak-aged beta-titanium alloys was characterized with a fracture mechanics method. Beta-21S is susceptible to EAC under rising load in neutral 3.5 pct NaCl at 25 C and -600 mVSCE, as indicated by a reduced threshold for subcritical crack growth ( K TH ), an average crack growth rate of up to 10

Lisa M. Young; George A. Young; John R. Scully; Richard P. Gangloff

1995-01-01

293

The Belt Pinch - A high-beta tokamak with non-circular cross-section  

Microsoft Academic Search

In a tokamak, the attainable beta-values are restricted by the limitations of MHD-stability. The necessary improvement of the beta-value should be possible by going over to a noncircular plasma cross section. In this paper, theoretical conditions for such an improvement are discussed (e.g., volume currents peaked on axis, flattened ends of the elongated cross-section, and diamagnetic plasma). Experimental investigations of

O. Gruber; R. Wilhelm

1976-01-01

294

Fission Thrust sail as booster for high {\\Delta}v fusion based propulsion  

E-print Network

The fission thrust sail as booster for nuclear fusion-based rocket propulsion for future starships is studied. Some required aspects of these systems such as neutron moderation and sail regeneration are discussed. First order calculations are used together with Monte Carlo simulations to assess system performance. When the fusion rocket has relatively low efficiency (~30%) in converting fusion fuel to a directed exhaust, adding a fission sail is shown to be beneficial for obtainable delta-v. Also, this type of fission-fusion hybrid interstellar propulsion has the potential to improve acceleration. Other advantages are discussed as well.

Ceyssens, Frederik; Driesen, Maarten

2014-01-01

295

Effective depth of spermatogonia in man II. Calculations for external high-energy beta rays.  

PubMed

An important criterion for dosemeter design for male gonad dosimetry in mixed beta-gamma fields is the effective spermatogonial depth. A detector set at this depth will register mean dose to the spermatogonia: this is the quantity of interest for genetic risk, which is proportional to the mean dose to the spermatogonia, averaged over the whole testicular volume. Factors affecting mean spermatogonial dose and effective depth of the spermatogonia were examined by computer using a simple mathematical model. Depth dose data were input from tables of beta dose. Mean spermatogonial dose shows a moderate dependence upon beta maximum energy, and a moderate inverse dependence upon scrotal thickness and source distance in air. Effective spermatogonial depth, while largely independent of source distance, shows strong dependence upon beta maximum energy: hence dosemeters designed for a given beta maximum energy will over-respond when exposed to betas of higher energy. Values of effective spermatogonial depth are given for two isotopes. In fields of mixed isotopes, weighting of the depths is essential for averaging. PMID:7178236

Facey, R A

1982-11-01

296

Reduced crying in term infants fed high beta-palmitate formula: a double-blind randomized clinical trial  

PubMed Central

Background Beta-palmitate (sn-2 palmitate) mimics human milk fat, enabling easier digestion. Therefore, we hypothesized that infants consuming high beta-palmitate formula would have more frequent, softer stools and reduced crying compared to infants consuming low beta-palmitate formula. Methods Formula-fed infants were randomly assigned to receive either (1) formula with high beta-palmitate (HBP, n?=?21) or (2) regular formula with a standard vegetable oil mix (LBP, n?=?21). A matched group of breastfed infants served as a reference (BF, n?=?21). Crying and stool characteristics data were recorded by the parents for 3days before the 6- and 12-week visits. Results We found no significant differences in the stool frequency or consistency between the two formula groups. The percentage of crying infants in the LBP group was significantly higher than that in the HBP and BF groups during the evening at 6weeks (88.2% vs. 56.3% and 55.6%, p?high beta-palmitate formula affects infant crying patterns during the first weeks of life. Comparable to breastfeeding, it reduced crying duration and frequency, primarily during the afternoon and evening hours, thereby improving the well-being of formula-fed infants and their parents. Trial registration NCT00874068. Registration date March 31, 2009 PMID:24942975

2014-01-01

297

Prediction of parallel in-register amyloidogenic beta-structures In highly beta-rich protein sequences by pairwise propensity analysis  

E-print Network

Amyloids and prion proteins are clinically and biologically important beta-structures, whose supersecondary structures are difficult to determine by standard experimental or computational means. In addition, significant ...

Bryan, Allen Wayne

2009-01-01

298

Matching Highly Non-ideal Ocular Images: An Information Fusion Approach Arun Ross, Raghavender Jillela (West Virginia University)  

E-print Network

the eye (viz., iris, retina, and sclera), the ocular region includes the eyelids, eyelashes, eyebrow and the skin texture in the vicinity of the eye. Tra- ditionally, research in ocular biometrics has focusedMatching Highly Non-ideal Ocular Images: An Information Fusion Approach Arun Ross, Raghavender

Plemmons, Robert J.

299

A fusion method of hyperspectral image based on spectral high fidelity applied in spectrum retrieval of vegetation species  

NASA Astrophysics Data System (ADS)

Urban grass is the interference object of vegetable species recognition. Therefore choose an instance of urban grass to retrieve the spectrum curve of interference vegetation. The spectrum retrieval of vegetation species includes three steps, 1) the Hyperspectral image preprocessing, 2) the high fidelity image fusion, and 3) the purity endmember extraction. Firstly, the Hyperspectral image is preprocessed including the removal of bad bands, the radiance calibration, and the FLAASH atmospheric correction. Secondly, the Gram-Schmidt fusion method which has an advantage of spectral high fidelity was employed to fuse the Hyperspectral image and the high spatial panchromatic image. Thirdly, the grass reference vectors was applied in masking the fusion image and then the minimum noise fraction was used to forward and inverse transform the masking image. The pixel purity index of image was calculated after de-noising and then the threshold range was determined to obtain the region of interest that has high purity. The principal component analysis was adopted to forward transform the visible, near infrared, shortwave infrared channels respectively and then the first and second bands of each channel were selected. The optimum index factor was used to acquire the eigenvalues of optimum bands combination and then the N-dimensional visualization was applied in extracting study area endmember of grass species. Finally the spectrum curve of urban grass was retrieved from the average endmember spectral of original fusion image.

Ji, Wei; Wang, Zhiyong; Wen, Qiang

2014-11-01

300

High-Resolution Depth Maps Based on TOF-Stereo Fusion Vineet Gandhi, Jan Cech, and Radu Horaud  

E-print Network

High-Resolution Depth Maps Based on TOF-Stereo Fusion Vineet Gandhi, Jan Cech, and Radu Horaud INRIA Grenoble Rh^one-Alpes, Montbonnot Saint-Martin, France {vineet.gandhi, jan.cech, radu measure the 3D structure of a scene at video V. Gandhi acknowledges support from the Erasmus Mundus CIMET

Paris-Sud XI, Université de

301

Detection of highly enriched uranium and tungsten surface damage studies using a pulsed inertial electrostatic confinement fusion device  

Microsoft Academic Search

The research in this thesis examines two applications of a pulsed Inertial Electrostatic Confinement (EEC) fusion device: detection of highly enriched uranium (HEU) and tungsten surface damage studies. In order to complete this thesis, a pulsed IEC device was developed that is capable of generating converging ion pulses with widths ranging from 0.1 to 5 ms at frequencies between 1

Ross F. Radel

2007-01-01

302

High-power-density approaches to magnetic fusion energy: problems and promise of compact Reversed-Field Pinch Reactors (CRFPR)  

SciTech Connect

If the costing assumptions upon which the positive assessment of conventional large superconducting fusion reactors are based proves overly optimistic, approaches that promise considerably increased system power density and reduced mass utilization will be required. These more compact reactor embodiments generally must operate with reduced shield thickness and resistive magnets. Because of the unique magnetic topology associated with the Reversed-Field Pinch (RFP), the compact reactor embodiment for this approach is particularly attractive from the view point of low-field resistive coils operating with Ohmic losses that can be made small relative to the fusion power. The RFP, therefore, is used as one example of a high-power-density (HPD) approach to magnetic fusion energy. A comprehensive system model is described and applied to select a unique, cost-optimized design point that will be used for a subsequent conceptual engineering design of the Compact RFP Reactor (CRFPR). This cost-optimized CRFPR design serves as an example of a HPD fusion reactor that would operate with system power densities and mass utilization that are comparable to fission power plants, these measures of system performance being an order of magnitude more favorable than the conventional approaches to magnetic fusion energy (MFE).

Hagenson, R.L.; Krakowski, R.A.; Dreicer, H.

1982-01-01

303

Technical assessment of critical Plasma-Materials Interaction (PMI) and High Heat Flux (HHF) issues for alternative fusion concepts (AFCs)  

SciTech Connect

A number of approaches to fusion energy are being pursued as alternative fusion concepts (AFCs). The goal of these systems is to provide a more desirable method of producing fusion energy than the mainline programs. Some of the AFCs have both a Low Power Density (LPD) option and a High Power Density (HPD) option. A summary of representative AFC programs and their associated PMI and HHF issues is followed by the technical assessment of the critical issues. These requirements are discussed relative to the mainline and/or HPD components. The HPD options are contrasted with a tabulation of the characteristics of components for the Reversed-Field Pinch (RFP), which is representative of the HPD concept.

Downing, J.N.

1986-03-01

304

Different pituitary. beta. -endorphin and adrenal cortisol response to ethanol in individuals with high and low risk for future development of alcoholism  

SciTech Connect

The purpose of the present studies was to investigate the activity of the adrenal gland and the pituitary {beta}-endorphin system in individuals from families with a 3 generation history of alcoholism, High Risk group, or from families without history of alcoholism, Low Risk group. On the day of testing, blood sample was taken at 9:00 a.m., then the subject drank a placebo drink or an ethanol solution. Additional blood samples were taken at 15, 45 and 120 minutes post-drink. Results indicated that individuals of the High Risk group had lower basal levels of {beta}-endorphin like immunoreactivity ({beta}-EPLIR) than individuals of the Low Risk group. The dose of 0.5 g ethanol/kg B.Wt. induced an induce an increase in the plasma content of {beta}-EPLIR of the High Risk group, but not of the Low Risk group. In the Low Risk group ethanol did not induce an increase above the 9:00 a.m. levels, however, it attenuated the {beta}-endorphin decrease overtime, observed following the placebo drink. Analysis of {beta}-endorphin-like peptides in the plasma of the High Risk group, with Sephadex G-75 chromatography indicated that the major component of the plasma {beta}-EPLIR was {beta}-lipotropin. Plasma cortisol levels, following ethanol intake, presented a small increase in the High Risk group but not in the Low Risk group.

Gianoulakis, C.G.; Beliveau, D.; Angelogianni, P.; Meaney, M.; Thavundayil, J.; Tawar, V.; Dumas, M. (McGill Univ., Quebec (Canada))

1989-01-01

305

High level information fusion for tracking and projection of multistage cyber attacks  

E-print Network

situation awareness of cyber attacks. Cor- relating alerts provides the network security analysts a view fusion to provide situation awareness and threat prediction from massive volumes of sensed data. An in information fusion. Relatively exten- sive work has been conducted to enhance the situation awareness

Kuhl, Michael E.

306

UNCORRECTED 2 High level information fusion for tracking and projection of multistage  

E-print Network

provide better situation awareness of cyber attacks. Cor- 50relating alerts provides the network security, this paper introduces information fusion 15 to provide situation awareness and threat prediction from massive. 20 Keywords: Cyber security; Information fusion; Situation and threat assessment; Alert correlation

Jay Yang, Shanchieh

307

Optimal shape of electrodes for high performance of inertial electrostatic confinement fusion  

Microsoft Academic Search

Inertial electrostatic confinement (IEC) fusion is a scheme of producing the ions between the anode and the hollow cathode in the concentric spheres by the glow discharge, accelerating the ions into the spherical center and giving rise to fusion reactions between the accelerated ions or between the accelerated ions and the background neutrals. A current feed-through is connected to the

R. Tanaka; H. Osawa; T. Tabata; T. Ishibashi; M. Ohnishi

2003-01-01

308

Shape of Electrodes for High Performance of Inertial Electrostatic Confinement Fusion  

Microsoft Academic Search

Inertial electrostatic confinement (IEC) fusion is a scheme of producing deuterium, tritium, and helium-3 ions between the anode and the hollow cathode in the concentric sphere by glow discharge, accelerating the ions into the spherical center and giving rise to the fusion reactions between the accelerated ions or between the accelerated ions and the background neutrals. The current feed-through is

Masami OHNISHI; Hodaka OSAWA; Ryo TANAKA; Naoki WAKIZAKA

2005-01-01

309

Limited access surgery for 360 degrees in-situ fusion in a dysraphic patient with high-grade spondylolisthesis.  

PubMed

Progressive high-grade spondylolisthesis can lead to spinal imbalance. High-grade spondylolisthesis is often reduced and fused in unbalanced pelvises, whereas in-situ fusion is used more often in balanced patients. The surgical goal is to recreate or maintain sagittal balance but if anatomical reduction is necessary, the risk of nerval damage with nerve root disruption in worst cases is increased. Spinal dysraphism like spina bifida or tethered cord syndrome make it very difficult to achieve reduction and posterior fusion due to altered anatomy putting the focus on anterior column support. Intensive neural structure manipulation should be avoided to reduce neurological complications and re-tethering in these cases. A 26-year-old patient with a history of diastematomyelia, occult spina bifida and tethered cord syndrome presented with new onset of severe low back pain, and bilateral L5/S1 sciatica after a fall. The X-ray demonstrated a grade III spondylolisthesis with spina bifida and the MRI scan revealed bilateral severely narrowed exit foramina L5 due to the listhesis. Because she was well balanced sagittally, the decision for in-situ fusion was made to minimise the risk of neurological disturbance through reduction. Anterior fusion was favoured to minimise manipulation of the dysraphic neural structures. Fusion was achieved via isolated access to the L4/L5 disc space. A L5 transvertebral hollow modular anchorage (HMA) screw was passed into the sacrum from the L4/L5 disc space and interbody fusion of L4/L5 was performed with a cage. The construct was augmented with pedicle screw fixation L4-S1 via a less invasive bilateral muscle split for better anterior biomechanical support. The postoperative course was uneventful and fusion was CT confirmed at the 6-month follow-up. At the last follow-up, she worked full time, was completely pain free and not limited in her free-time activities. The simultaneous presence of high-grade spondylolisthesis and spinal dysraphism make it very difficult to find a decisive treatment plan because both posterior and anterior treatment strategies have advantages and disadvantages in these challenging cases. The described technique combines several surgical options to achieve 360 fusion with limited access, reducing the risk of neurological sequelae. PMID:22008862

Knig, M A; Boszczyk, B M

2012-03-01

310

High-speed surface temperature measurements on plasma facing materials for fusion applications  

SciTech Connect

For the lifetime evaluation of plasma facing materials in fusion experimental machines, it is essential to investigate their surface behavior and their temperature responses during an off-normal event such as the plasma disruptions. An infrared thermometer with a sampling speed as fast as 1{times}10{sup {minus}6} s/data, namely, the high-speed infrared thermometer (HSIR), has been developed by the National Research Laboratory of Metrology in Japan. To evaluate an applicability of the newly developed HSIR on the surface temperature measurement of plasma facing materials, high heat flux beam irradiation experiments have been performed with three different materials under the surface heat fluxes up to 170 MW/m{sup 2} for 0.04 s in a hydrogen ion beam test facility at the Japan Atomic Energy Research Institute. As for the results, HSIR can be applicable for measuring the surface temperature responses of the armor tile materials with a little modification. It is also confirmed that surface temperatures measured with the HSIR thermometer show good agreement with the analytical results for stainless steel and carbon based materials at a temperature range of up to 2500{degree}C. However, for aluminum the HSIR could measure the temperature of the high dense vapor cloud which was produced during the heating due to lower melting temperature. Based on the result, a multichannel arrayed HSIR thermometer has been designed and fabricated. {copyright} {ital 1996 American Institute of Physics.}

Araki, M. [Naka Fusion Research Establishment, Japan Atomic Energy Research Institute, 801-1, Naka-machi, Naka-gun, Ibaraki, 311-01 (Japan)] [Naka Fusion Research Establishment, Japan Atomic Energy Research Institute, 801-1, Naka-machi, Naka-gun, Ibaraki, 311-01 (Japan); Kobayashi, M. [Thermal Measurement Section, Thermophysical Metrology Department, National Research Laboratory of Metrology, 1-1-4, Umezono, Tsukuba, Ibaraki, 305 (Japan)] [Thermal Measurement Section, Thermophysical Metrology Department, National Research Laboratory of Metrology, 1-1-4, Umezono, Tsukuba, Ibaraki, 305 (Japan)

1996-01-01

311

A High Temperature Electrochemical Energy Storage System Based on Sodium Beta-Alumina Solid Electrolyte (Base)  

SciTech Connect

This report summarizes the work done during the period September 1, 2005 and March 31, 2008. Work was conducted in the following areas: (1) Fabrication of sodium beta{double_prime} alumina solid electrolyte (BASE) using a vapor phase process. (2) Mechanistic studies on the conversion of {alpha}-alumina + zirconia into beta{double_prime}-alumina + zirconia by the vapor phase process. (3) Characterization of BASE by X-ray diffraction, SEM, and conductivity measurements. (4) Design, construction and electrochemical testing of a symmetric cell containing BASE as the electrolyte and NaCl + ZnCl{sub 2} as the electrodes. (5) Design, construction, and electrochemical evaluation of Na/BASE/ZnCl{sub 2} electrochemical cells. (6) Stability studies in ZnCl{sub 2}, SnCl{sub 2}, and SnI{sub 4} (7) Design, assembly and testing of planar stacks. (8) Investigation of the effect of porous surface layers on BASE on cell resistance. The conventional process for the fabrication of sodium ion conducting beta{double_prime}-alumina involves calcination of {alpha}-alumina + Na{sub 2}CO{sub 3} + LiNO{sub 3} at 1250 C, followed by sintering powder compacts in sealed containers (platinum or MgO) at {approx}1600 C. The novel vapor phase process involves first sintering a mixture of {alpha}-alumina + yttria-stabilized zirconia (YSZ) into a dense ceramic followed by exposure to soda vapor at {approx}1450 C to convert {alpha}-alumina into beta{double_prime}-alumina. The vapor phase process leads to a high strength BASE, which is also resistant to moisture attack, unlike BASE made by the conventional process. The PI is the lead inventor of the process. Discs and tubes of BASE were fabricated in the present work. In the conventional process, sintering of BASE is accomplished by a transient liquid phase mechanism wherein the liquid phase contains NaAlO{sub 2}. Some NaAlO{sub 2} continues to remain at grain boundaries; and is the root cause of its water sensitivity. In the vapor phase process, NaAlO{sub 2} is never formed. Conversion occurs by a coupled transport of Na{sup +} through BASE formed and of O{sup 2-} through YSZ to the reaction front. Transport to the reaction front is described in terms of a chemical diffusion coefficient of Na{sub 2}O. The conversion kinetics as a function of microstructure is under investigation. The mechanism of conversion is described in this report. A number of discs and tubes of BASE have been fabricated by the vapor phase process. The material was investigated by X-ray diffraction (XRD), optical microscopy and scanning electron microscopy (SEM), before and after conversion. Conductivity (which is almost exclusively due to sodium ion transport at the temperatures of interest) was measured. Conductivity was measured using sodium-sodium tests as well as by impedance spectroscopy. Various types of both planar and tubular electrochemical cells were assembled and tested. In some cases the objective was to determine if there was any interaction between the salt and BASE. The interaction of interest was mainly ion exchange (possible replacement of sodium ion by the salt cation). It was noted that Zn{sup 2+} did not replace Na+ over the conditions of interest. For this reason much of the work was conducted with ZnCl{sub 2} as the cathode salt. In the case of Sn-based, Sn{sup 2+} did ion exchange, but Sn{sup 4+} did not. This suggests that Sn{sup 4+} salts are viable candidates. These results and implications are discussed in the report. Cells made with Na as the anode and ZnCl{sub 2} as the cathode were successfully charged/discharged numerous times. The key advantages of the batteries under investigation here over the Na-S batteries are: (1) Steel wool can be used in the cathode compartment unlike Na-S batteries which require expensive graphite. (2) Planar cells can be constructed in addition to tubular, allowing for greater design flexibility and integration with other devices such as planar SOFC. (3) Comparable or higher open circuit voltage (OCV) than the Na-S battery. (4) Wider operating temperature range and higher temper

Anil Virkar

2008-03-31

312

High frequency Agrobacterium -mediated transformation and plant regeneration via direct shoot formation from leaf explants in Beta vulgaris and Beta maritima  

Microsoft Academic Search

We have developed a new procedure for Agrobacterium-mediated transformation of plants in the genus Beta using shoot-base as the material for Agrobacterium infection. The frequency of regeneration from shoot bases was analyzed in seven accessions of sugarbeet ( Beta vulgaris) and two accessions of B. maritima to select materials suitable for obtaining transformed plants. The frequency of transformation of the

H. Hisano; Y. Kimoto; H. Hayakawa; J. Takeichi; T. Domae; R. Hashimoto; J. Abe; S. Asano; A. Kanazawa; Y. Shimamoto

2004-01-01

313

Pancreatic Beta Cells Are Highly Susceptible to Oxidative and ER Stresses during the Development of Diabetes.  

PubMed

The complex interplay of many cell types and the temporal heterogeneity of pancreatic islet composition obscure the direct role of resident alpha and beta cells in the development of Type 1 diabetes. Therefore, in addition to studying islets isolated from non-obese diabetic mice, we analyzed homogeneous cell populations of murine alpha (?TC-1) and beta (NIT-1) cell lines to understand the role and differential survival of these two predominant islet cell populations. A total of 56 proteins in NIT-1 cells and 50 in ?TC-1 cells were differentially expressed when exposed to proinflammatory cytokines. The major difference in the protein expression between cytokine-treated NIT-1 and ?TC-1 cells was free radical scavenging enzymes. A similar observation was made in cytokine-treated whole islets, where a comprehensive analysis of subcellular fractions revealed that 438 unique proteins were differentially expressed under inflammatory conditions. Our data indicate that beta cells are relatively susceptible to ER and oxidative stress and reveal key pathways that are dysregulated in beta cells during cytokine exposure. Additionally, in the islets, inflammation also leads to enhanced antigen presentation, which completes a three-way insult on beta cells, rendering them targets of infiltrating T lymphocytes. PMID:25412008

Gorasia, Dhana G; Dudek, Nadine L; Veith, Paul D; Shankar, Renu; Safavi-Hemami, Helena; Williamson, Nicholas A; Reynolds, Eric C; Hubbard, Michael J; Purcell, Anthony W

2015-02-01

314

Pattern recognition of $^{136}$Xe double beta decay events and background discrimination in a high pressure Xenon TPC  

E-print Network

High pressure gas detectors offer advantages for the detection of rare events, where background reduction is crucial. For the neutrinoless double beta decay of 136Xe a high pressure xenon gas Time Projection Chamber (TPC) combines a good energy resolution and a detailed topological information of each event. The ionization topology of the double beta decay event of 136Xe in gaseous xenon has a characteristic shape defined by the two straggling electron tracks ending up in two higher ionization charge density blobs. With a properly pixelized readout, this topological information is invaluable to perform powerful background discrimination. In this study we carry out detailed simulations of the signal topology, as well as the competing topologies from gamma events that typically compose the background at these energies. We define observables based on graph theory concepts and develop automated discrimination algorithms which reduce the background level in around three orders of magnitude while keeping signal eff...

Cebrian, S; Gomez, H; Herrera, D C; Iguaz, F J; Irastorza, I G; Luzon, G; Segui, L; Tomas, A

2013-01-01

315

Status and future prospects of laser fusion and high power laser applications  

NASA Astrophysics Data System (ADS)

In Asia, there are many institutes for the R&D of high power laser science and applications. They are 5 major institutes in Japan, 4 major institutes in China, 2 institutes in Korea, and 3 institutes in India. The recent achievements and future prospects of those institutes will be over viewed. In the laser fusion research, the FIREX-I project in Japan has been progressing. The 10kJ short pulse LFEX laser has completed and started the experiments with a single beam. About 1kJ pulse energy will be injected into a cone target. The experimental results of the FIREX experiments will be presented. As the target design for the experiments, a new target, namely, a double cone target was proposed, in which the high energy electrons are well confined and the heating efficiency is significantly improved. Together with the fusion experiments, Osaka University has carried out laboratory astrophysics experiments on photo ionizing plasmas to observe a unique X-ray spectrum from non-LTE plasmas. In 2008, Osaka university has started a new Photon research center in relation with the new program: Consortium for Photon Science and Technology: C-PhoST, in which ultra intense laser plasmas research and related education will be carried out for 10 years. At APRI, JAEA, the fundamental science on the relativistic laser plasmas and the applications of laser particle acceleration has been developed. The application of laser ion acceleration has been investigated on the beam cancer therapy since 2007. In China, The high power glass laser: Shenguan-II and a peta watt beam have been operated to work on radiation hydro dynamics at SIOFM Shanghai. The laser material and optics are developed at SIOFM and LFRC. The IAPCM and the IOP continued the studies on radiation hydrodynamics and on relativistic laser plasmas interactions. At LFRC in China, the construction of Shenguan III glass laser of 200kJ in blue has progressed and will be completed in 2012. Together with the Korean program, I will overview the above Asian programs.

Mima, Kunioki

2010-08-01

316

The highs and lows of beta activity in cortico-basal ganglia loops.  

PubMed

Oscillatory activity in the beta (13-30Hz) frequency band is widespread in cortico-basal ganglia circuits, and becomes prominent in Parkinson's disease (PD). Here we develop the hypothesis that the degree of synchronization in this frequency band is a critical factor in gating computation across a population of neurons, with increases in beta band synchrony entailing a loss of information-coding space and hence computational capacity. Task and context drive this dynamic gating, so that for each state there will be an optimal level of network synchrony, and levels lower or higher than this will impair behavioural performance. Thus, both the pathological exaggeration of synchrony, as observed in PD, and the ability of interventions like deep brain stimulation (DBS) to excessively suppress synchrony can potentially lead to impairments in behavioural performance. Indeed, under physiological conditions, the manipulation of computational capacity by beta activity may itself present a mechanism of action selection and maintenance. PMID:24890470

Brittain, John-Stuart; Sharott, Andrew; Brown, Peter

2014-06-01

317

Understanding the potential and pH dependency of high-strength beta-titanium alloy environmental crack initiation  

Microsoft Academic Search

An explanation for the strong dependency of crack initiation of precracked high-strength beta-titanium alloys in room-temperature 0.6 M NaCl on applied potential and bulk-solution pH is presented. It is proposed that environment-assisted cracking (EAC) susceptibility in neutral aqueous NaCl results from (1) film rupture due to plastic deformation at actively deformed crack tips, (2) accelerated dissolution of titanium, (3) crack

D. G. Kolman; J. R. Scully

1997-01-01

318

Application of Neural Networks for Real Time Determination of High-beta Disruption Boundary and Current Profile Parameters  

Microsoft Academic Search

Neural networks are adept at reproducing multidemensional non-linear mappings and, due to the simplicity of computation of network outputs, are particularly suitable for real time applications. A neural network empirical model of the high-beta disruption boundary was constructed and its real-time performance demonstrated on the DIII--D tokamak. Neural network using multiple diagnostic signals provides much better evaluation of the disruption

D. Wroblewski; G. L. Jahns; J. A. Leuer; J. R. Ferron; A. G. Kellman

1996-01-01

319

Aqueous environmental crack propagation in high-strength beta titanium alloys  

Microsoft Academic Search

The aqueous environment-assisted cracking (EAC) behavior of two peak-aged beta-titanium alloys was characterized with a fracture\\u000a mechanics method. Beta-21S is susceptible to EAC under rising load in neutral 3.5 pct NaCl at 25 C and ?600 mVSCE, as indicated by a reduced threshold for subcritical crack growth (K\\u000a \\u000a TH\\u000a ), an average crack growth rate of up to 10 ?ms,

Lisa M. Young; George A. Young; John R. Scully; Richard P. Gangloff

1995-01-01

320

Electron kinetic effects on interferometry and polarimetry in high temperature fusion plasmas  

NASA Astrophysics Data System (ADS)

At anticipated high electron temperatures in ITER, the effects of electron thermal motion on phase measurements made by the toroidal interferometer/polarimeter (TIP) and poloidal polarimeter (PoPola) diagnostics will be significant and must be precisely treated or the measurement accuracy will fail to meet the specified requirements for ITER operation. We calculate electron thermal corrections to the interferometric phase and polarization state of an electromagnetic wave propagating along tangential and poloidal chords (Faraday and Cotton-Mouton polarimetry) and incorporate them into the Stokes vector equation for evolution of polarization. Although these corrections are small at electron temperatures Te ? 1 keV, they become sizable at Te ? 10 keV. The precision of the previous lowest order linear in the ? = Te/mec2 model may be insufficient; we present a more precise model with ?2-order corrections to satisfy the high accuracy required for ITER TIP and PoPola diagnostics. Proper treatment of temperature effects will ensure more accurate interpretation of interferometric and polarimetric measurements in fusion devices like ITER and DEMO. The use of precise analytic expressions is especially important for burning plasmas where various interferometric techniques will be used for direct real time feedback control of device operations with time resolution 1 ms to regulate the rate of the thermonuclear burn and monitor/control the safety factor profile.

Mirnov, V. V.; Brower, D. L.; Den Hartog, D. J.; Ding, W. X.; Duff, J.; Parke, E.

2013-11-01

321

Fusion of laser scanning data and optical high-resolution imagery for accurate building boundary derivation  

NASA Astrophysics Data System (ADS)

A novel approach by the fusion of airborne laser scanning data and optical high-resolution imagery is proposed for automatically obtaining building boundaries with precise geometric position and details. The high-resolution images are used to directly extract the building boundaries with precise geometric position, and the laser scanning data are integrated to improve the correctness and completeness of the extracted boundaries. In this approach, a new method is first proposed to estimate the principal orientations of a building, based on the building image and rough principal direction constraints, which ensures the accuracy and robustness of the subsequent line segment extraction. On this basis, accurate boundary segments are extracted using a method based on laser scanning point density analysis and K-means clustering. Images from different sensors, including orthoimage, aerial stereo, or some other images, are able to be processed effectively. Experiments covering more than 200 buildings with various orientations, various structures, and various texture conditions are employed to test the proposed approach. The average correctness and completeness of the determined boundaries are 95% and 90%, respectively.

Cheng, Liang; Tong, Lihua; Liu, Yongxue; Li, Manchun

2013-01-01

322

Spatially resolved high resolution x-ray spectroscopy for magnetically confined fusion plasmas (invited).  

PubMed

The use of high resolution x-ray crystal spectrometers to diagnose fusion plasmas has been limited by the poor spatial localization associated with chord integrated measurements. Taking advantage of a new x-ray imaging spectrometer concept [M. Bitter et al., Rev. Sci. Instrum. 75, 3660 (2004)], and improvements in x-ray detector technology [Ch. Broennimann et al., J. Synchrotron Radiat. 13, 120 (2006)], a spatially resolving high resolution x-ray spectrometer has been built and installed on the Alcator C-Mod tokamak. This instrument utilizes a spherically bent quartz crystal and a set of two dimensional x-ray detectors arranged in the Johann configuration [H. H. Johann, Z. Phys. 69, 185 (1931)] to image the entire plasma cross section with a spatial resolution of about 1 cm. The spectrometer was designed to measure line emission from H-like and He-like argon in the wavelength range 3.7 and 4.0 A with a resolving power of approximately 10,000 at frame rates up to 200 Hz. Using spectral tomographic techniques [I. Condrea, Phys. Plasmas 11, 2427 (2004)] the line integrated spectra can be inverted to infer profiles of impurity emissivity, velocity, and temperature. From these quantities it is then possible to calculate impurity density and electron temperature profiles. An overview of the instrument, analysis techniques, and example profiles are presented. PMID:19044464

Ince-Cushman, A; Rice, J E; Bitter, M; Reinke, M L; Hill, K W; Gu, M F; Eikenberry, E; Broennimann, Ch; Scott, S; Podpaly, Y; Lee, S G; Marmar, E S

2008-10-01

323

Experimental investigation of opacity models for stellar interior, inertial fusion, and high energy density plasmas  

SciTech Connect

Theoretical opacities are required for calculating energy transport in plasmas. In particular, understanding stellar interiors, inertial fusion, and Z pinches depends on the opacities of mid-atomic-number elements over a wide range of temperatures. The 150-300 eV temperature range is particularly interesting. The opacity models are complex and experimental validation is crucial. For example, solar models presently disagree with helioseismology and one possible explanation is inadequate theoretical opacities. Testing these opacities requires well-characterized plasmas at temperatures high enough to produce the ion charge states that exist in the sun. Typical opacity experiments heat a sample using x rays and measure the spectrally resolved transmission with a backlight. The difficulty grows as the temperature increases because the heating x-ray source must supply more energy and the backlight must be bright enough to overwhelm the plasma self-emission. These problems can be overcome with the new generation of high energy density (HED) facilities. For example, recent experiments at Sandia's Z facility [M. K. Matzen et al., Phys. Plasmas 12, 055503 (2005)] measured the transmission of a mixed Mg and Fe plasma heated to 156{+-}6 eV. This capability will also advance opacity science for other HED plasmas. This tutorial reviews experimental methods for testing opacity models, including experiment design, transmission measurement methods, accuracy evaluation, and plasma diagnostics. The solar interior serves as a focal problem and Z facility experiments illustrate the techniques.

Bailey, J. E.; Rochau, G. A. [Sandia National Laboratories, Albuquerque, New Mexico, 87185-1196 (United States); Mancini, R. C. [University of Nevada, Reno, Nevada 89557 (United States); Iglesias, C. A. [Lawrence Livermore National Laboratory, University of California, Livermore, California 94550 (United States); MacFarlane, J. J.; Golovkin, I. E. [Prism Computational Sciences, Madison, Wisconsin 53703 (United States); Blancard, C.; Cosse, Ph.; Faussurier, G. [CEA, DAM, DIF, F-91297 Arpajon (France)

2009-05-15

324

Pattern recognition of $^{136}$Xe double beta decay events and background discrimination in a high pressure Xenon TPC  

E-print Network

High pressure gas detectors offer advantages for the detection of rare events, where background reduction is crucial. For the neutrinoless double beta decay of 136Xe a high pressure xenon gas Time Projection Chamber (TPC) combines a good energy resolution and a detailed topological information of each event. The ionization topology of the double beta decay event of 136Xe in gaseous xenon has a characteristic shape defined by the two straggling electron tracks ending up in two higher ionization charge density blobs. With a properly pixelized readout, this topological information is invaluable to perform powerful background discrimination. In this study we carry out detailed simulations of the signal topology, as well as the competing topologies from gamma events that typically compose the background at these energies. We define observables based on graph theory concepts and develop automated discrimination algorithms which reduce the background level in around three orders of magnitude while keeping signal efficiency of 40%. This result supports the competitiveness of current or future double beta experiments based on gas TPCs, like the Neutrino Xenon TPC (NEXT) currently under construction in the Laboratorio Subterraneo de Canfranc (LSC).

S Cebrian; T Dafni; H Gomez; D C Herrera; F J Iguaz; I G Irastorza; G Luzon; L Segui; A Tomas

2013-10-17

325

Magnetized target fusion: An ultra high energy approach in an unexplored parameter space  

NASA Astrophysics Data System (ADS)

Magnetized target fusion is a concept that may lead to practical fusion applications in a variety of settings. However, the crucial first step is to demonstrate that it works as advertised. Among the possibilities for doing this is an ultrahigh energy approach to magnetized target fusion, one powered by explosive pulsed power generators that have become available for application to thermonuclear fusion research. In a collaborative effort between Los Alamos and the All-Russian Scientific Institute for Experimental Physics (VNIIEF) a very powerful helical generator with explosive power switching has been used to produce an energetic magnetized plasma. Several diagnostics have been fielded to ascertain the properties of this plasma. We are intensively studying the results of the experiments and calculationally analyzing the performance of this experiment.

Lindemuth, I. R.

326

Aerosol Resuspension Model for MELCOR for Fusion and Very High Temperature Reactor Applications  

SciTech Connect

Dust is generated in fusion reactors from plasma erosion of plasma facing components within the reactors vacuum vessel (VV) during reactor operation. This dust collects in cooler regions on interior surfaces of the VV. Because this dust can be radioactive, toxic, and/or chemically reactive, it poses a safety concern, especially if mobilized by the process of resuspension during an accident and then transported as an aerosol though out the reactor confinement building, and possibly released to the environment. A computer code used at the Idaho National Laboratory (INL) to model aerosol transport for safety consequence analysis is the MELCOR code. A primary reason for selecting MELCOR for this application is its aerosol transport capabilities. The INL Fusion Safety Program (FSP) organization has made fusion specific modifications to MELCOR. Recent modifications include the implementation of aerosol resuspension models in MELCOR 1.8.5 for Fusion. This paper presents the resuspension models adopted and the initial benchmarking of these models.

B.J. Merrill

2011-01-01

327

Thin Shell, High Velocity Inertial Confinement Fusion Implosions on the National Ignition Facility  

E-print Network

Experiments have recently been conducted at the National Ignition Facility utilizing inertial confinement fusion capsule ablators that are 175 and 165???m in thickness, 10% and 15% thinner, respectively, than the nominal ...

Ma, T.

328

Magnetized target fusion: An ultra high energy approach in an unexplored parameter space  

SciTech Connect

Magnetized target fusion is a concept that may lead to practical fusion applications in a variety of settings. However, the crucial first step is to demonstrate that it works as advertised. Among the possibilities for doing this is an ultrahigh energy approach to magnetized target fusion, one powered by explosive pulsed power generators that have become available for application to thermonuclear fusion research. In a collaborative effort between Los Alamos and the All-Russian Scientific Institute for Experimental Physics (VNIIEF) a very powerful helical generator with explosive power switching has been used to produce an energetic magnetized plasma. Several diagnostics have been fielded to ascertain the properties of this plasma. We are intensively studying the results of the experiments and calculationally analyzing the performance of this experiment.

Lindemuth, I.R.

1994-12-31

329

A high-risk patient with long-QT syndrome with no response to cardioselective beta-blockers.  

PubMed

We present a case of a high-risk 19-year-old female with long-QT syndrome (LQTS) with compound mutations. She had a history of aborted cardiac arrest and syncope and had received treatment with propranolol for 15years. However, because she developed adult-onset asthma we tried to switch propranolol, a nonselective beta-blocker, to beta-1-cardioselective agents, bisoprolol and metoprolol. These resulted in both a markedly prolonged corrected QT interval and the development of LQTS-associated arrhythmias. Eventually, propranolol was reinitiated at a higher dose with the addition of verapamil, and she has had no further cardiac or asthmatic events for 5years. PMID:25028166

Toyota, Naoki; Miyazaki, Aya; Sakaguchi, Heima; Shimizu, Wataru; Ohuchi, Hideo

2014-06-11

330

Development of superconductors for applications in high-field, high-current-density magnets for fusion research  

SciTech Connect

The development of large-bore, high-field magnets for fusion energy applications requires a system approach to both magnet and conductor design. At Lawrence Livermore National Laboratory (LLNL), the criteria used to choose superconductors include: strain tolerance, radiation tolerance, heat removal, stability, fabricability, and cost. We report on the performance of industrially produced, prototype, Ti-modified Nb/sub 3/Sn wires developed with LLNL support. Wire performance characteristics evaluated include critical current as a function of magnetic field, temperature, and applied strain. Tests were performed to determine how this performance translates to the performance of a cable-in-conduit conductor system using this wire. An alternative to Nb/sub 3/Sn superconductors is NbN, which is strain and radiation insensitive. We report preliminary efforts to produce multifilamentary NbN conductors by liquid-metal infiltration of NbN-coated, high-strength fibers. In addition, we discuss the fabrication of multifilamentary NbN conductors and their possible impact on magnet design.

Summers, L.T.; Miller, J.R.

1986-09-26

331

Progress towards a high-gain and robust target design for heavy ion fusion  

SciTech Connect

Recently [E. Henestroza et al., Phys. Plasmas 18, 032702 (2011)], a new inertial-fusion target configuration, the X-target, using one-sided axial illumination has been explored. This class of target uses annular and solid-profile heavy ion beams to compress and ignite deuterium-tritium (DT) fuel that fills the interior of metal cases that have side-view cross sections in the shape of an 'X.' X-targets using all-DT-filled metal cases imploded by three annular ion beams resulted in fuel densities of {approx}50 g/cm{sup 3} at peak compression, and fusion gains of {approx}50, comparable to heavy ion driven hohlraum targets [D. A. Callahan-Miller and M. Tabak, Phys. Plasmas 7, 2083 (2000)]. This paper discusses updated X-target configurations that incorporate inside the case a propellant (plastic) and a pusher (aluminum) surrounding the DT fuel. The updated configurations are capable of assembling higher fuel areal densities {approx}2 g/cm{sup 2} using two annular beams to implode the target to peak DT densities {approx}100 g/cm{sup 3}, followed by a fast-ignition solid ion beam which heats the high-density fuel to thermonuclear temperatures in {approx}200 ps to start the burn propagation, obtaining gains of {approx}300. These targets have been modeled using the radiation-hydrodynamics code HYDRA [M. M. Marinak et al., Phys. Plasmas 8, 2275 (2001)] in two- and three- dimensions to study the properties of the implosion as well as the ignition and burn propagation phases. At typical Eulerian mesh resolutions of a few microns, the aluminum-DT interface shows negligible Rayleigh-Taylor (RT) and Richtmyer-Meshkov instability growth; also, the shear flow of the DT fuel as it slides along the metal X-target walls, which drives the RT and Kelvin Helmholtz instabilities, does not have a major effect on the burning rate. An analytic estimate of the RT instability process at the Al-DT interface shows that the aluminum spikes generated during the pusher deceleration phase would not reach the ignition zone in time to affect the burning process. Also, preliminary HYDRA calculations, using a higher resolution mesh to study the shear flow of the DT fuel along the X-target walls, indicate that metal-mixed fuel produced near the walls would not be transferred to the DT ignition zone (at maximum {rho}R) located at the vertex of the X-target.

Henestroza, Enrique; Grant Logan, B. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2012-07-15

332

Dynamic measurements of the structure of a vapor cloud formed during high powered fusion relevant disruptions  

NASA Astrophysics Data System (ADS)

The Divertor Erosion and Vapor shielding eXperiment (DEVeX) at the University of Illinois at Urbana-Champaign is designed to produce plasmas with densities on the order of 10^21 m-3 with a total plasma temperature (Ti + Te) of several hundred eV. This is accomplished with the rapid discharge of a 64 kJ capacitor bank through a conical shaped ?-pinch coil. The general purpose of the facility is to generate energetic plasma flows to study plasma-material interaction relevant to disruption conditions in TOKAMAKs. Here, the first measurements of the plasma flow and the resultant vapor cloud produced during the plasma strike are presented. Lithium is used as the plasma facing material due to its low melting temperature and high vapor pressure as well as for its resurgent use in the fusion community. Measurements of the vapor cloud dynamics are accomplished with an array of fiber optics extending perpendicularly away from the lithium target. Vapor cloud density is measured by resonance absorption of the 670 nm lithium line. This work is important to plasma facing component (PFC) lifetime and viability as the presence of a vapor cloud can absorb the incident energy of a disruption.

Gray, Travis; Jaworski, Michael; Surla, Vijay; Ruzic, David

2008-11-01

333

Weapons Activities/ Inertial Confinement Fusion Ignition  

E-print Network

Weapons Activities/ Inertial Confinement Fusion Ignition and High Yield Campaign FY 2012 Congressional Budget Inertial Confinement Fusion Ignition and High Yield Campaign Funding Profile by Subprogram FY 2010 Actual Appropriation FY 2011 Request FY 2012 Request Inertial Confinement Fusion Ignition

334

Simultaneous high-P, high-T X ray diffraction study of beta-(Mg,Fe)2SiO4 to 26 GPa and 900 K  

NASA Technical Reports Server (NTRS)

Attention is given to the lattice parameters of beta phase (Mg(0.84)Fe(0.16))2SiO4 determined by X-ray diffraction using synchrotron radiation under simultaneous high-pressure and high-temperature conditions. The experiments were conducted up to a pressure of 26 GPa and a temperature of 900 K. High pressures were generated in a Mao-Bell type diamond anvil cell using neon gas as a pressure medium. The sample was heated with an external Ni80Cr20 wire heater. Gold was used as an internal high-pressure calibrant at high temperature. The experimental data indicated the anisotropic behavior of the beta phase at high pressure and temperature, i.e., the c axis is about 35-percent more expansible and about 25-percent more compressible than the a and b axes. A value of 5.1 +/-0.8 was found for the Anderson-Grueneisen parameter. The derived thermodynamic parameters for the beta phase are summarized.

Fei, Yingwei; Mao, Ho-Kwang; Shu, Jinfu; Parthasarathy, G.; Bassett, W. A.; Ko, Jaidong

1992-01-01

335

A National Collaboratory to Advance the Science of High Temperature Plasma Physics for Magnetic Fusion  

SciTech Connect

This report summarizes the work of the National Fusion Collaboratory (NFC) Project to develop a persistent infrastructure to enable scientific collaboration for magnetic fusion research. The original objective of the NFC project was to develop and deploy a national FES ??Grid (FusionGrid) that would be a system for secure sharing of computation, visualization, and data resources over the Internet. The goal of FusionGrid was to allow scientists at remote sites to participate as fully in experiments and computational activities as if they were working on site thereby creating a unified virtual organization of the geographically dispersed U.S. fusion community. The vision for FusionGrid was that experimental and simulation data, computer codes, analysis routines, visualization tools, and remote collaboration tools are to be thought of as network services. In this model, an application service provider (ASP provides and maintains software resources as well as the necessary hardware resources. The project would create a robust, user-friendly collaborative software environment and make it available to the US FES community. This Grid'??s resources would be protected by a shared security infrastructure including strong authentication to identify users and authorization to allow stakeholders to control their own resources. In this environment, access to services is stressed rather than data or software portability.

Schissel, David P. [Princeton Plasma Physics Lab., NJ (United States); Abla, G. [Princeton Plasma Physics Lab., NJ (United States); Burruss, J. R. [Princeton Plasma Physics Lab., NJ (United States); Feibush, E. [Princeton Plasma Physics Lab., NJ (United States); Fredian, T. W. [Massachusetts Institute of Technology, Cambridge, MA (United States); Goode, M. M. [Lawrence Berkeley National Lab., CA (United States); Greenwald, M. J. [Massachusetts Institute of Technology, Cambridge, MA (United States); Keahey, K. [Argonne National Lab., IL (United States); Leggett, T. [Argonne National Lab., IL (United States); Li, K. [Princeton Univ., NJ (United States); McCune, D. C. [Princeton Plasma Physics Lab., NJ (United States); Papka, M. E. [Argonne National Lab., IL (United States); Randerson, L. [Princeton Plasma Physics Lab., NJ (United States); Sanderson, A. [Univ. of Utah, Salt Lake City, UT (United States); Stillerman, J. [Massachusetts Institute of Technology, Cambridge, MA (United States); Thompson, M. R. [Lawrence Berkeley National Lab., CA (United States); Uram, T. [Argonne National Lab., IL (United States); Wallace, G. [Princeton Univ., NJ (United States)

2012-12-20

336

A fusion power plant without plasma-material interactions  

SciTech Connect

A steady-state fusion power plant is described which avoids the deleterious plasma-material interactions found in D-T fueled tokamaks. It is based on driven p-{sup 11}B fusion in a high-beta closed-field device, the field-reversed configuration (FRC), anchored in a gas-dynamic trap (GDT). The plasma outflow on the open magnetic-field lines is cooled by radiation in the GDT, then channeled through a magnetic nozzle, promoting 3-body recombination in the expansion region. The resulting supersonic neutral exhaust stream flows through a turbine, generating electricity.

Cohen, S.A.

1997-04-01

337

High-beta operation and magnetohydrodynamic activity on the TFTR tokamak  

Microsoft Academic Search

Magnetohydrodynamic (MHD) activity within three zones (core, half-radius, and edge) of TFTR [PlasmaPhysicsandControlledNuclearFusionResearch1986 (IAEA, Vienna, 1987), Vol. 1, p. 51] tokamak plasmas are discussed. Near the core of the plasma column, sawteeth are often observed. Two types of sawteeth are studied in detail; one with complete, and the other with incomplete, magnetic reconnection. Their characteristics are determined by the shape

K. McGuire; V. Arunasalam; C. W. Barnes; M. G. Bell; M. Bitter; R. Boivin; N. L. Bretz; R. Budny; C. E. Bush; A. Cavallo; T. K. Chu; S. A. Cohen; P. Colestock; S. L. Davis; D. L. Dimock; P. C. Efthimion; A. B. Ehrhrardt; R. J. Fonck; E. Fredrickson; H. P. Furth; G. Gammel; R. J. Goldston; G. Greene; B. Grek; L. R. Grisham; G. Hammett; R. J. Hawryluk; H. W. Hendel; K. W. Hill; E. Hinnov; D. J. Hoffman; J. Hosea; R. B. Howell; H. Hsuan; R. A. Hulse; A. C. Janos; D. Jassby; F. Jobes; D. W. Johnson; L. C. Johnson; R. Kaita; C. Kieras-Phillips; S. J. Kilpatrick; P. H. LaMarche; B. LeBlanc; D. M. Manos; D. K. Mansfield; E. Mazzucato; M. P. McCarthy; M. C. McCune; D. H. McNeill; D. M. Meade; S. S. Medley; D. R. Mikkelsen; D. Monticello; R. Motley; D. Mueller; J. A. Murphy; Y. Nagayama; D. R. Nazakian; E. B. Neischmidt; D. K. Owens; S. Pitcher; A. T. Ramsey; M. H. Redi; A. L. Roquemore; P. H. Rutherford; G. Schilling; J. Schivell; G. L. Schmidt; S. D. Scott; J. C. Sinnis; J. Stevens; B. C. Stratton; W. Stodiek; E. J. Synakowski; W. M. Tang; G. Taylor; J. R. Timberlake; H. H. Towner; M. Ulrickson; S. von Goeler; R. Wieland; M. Williams; J. R. Wilson; K.-L. Wong; M. Yamada; S. Yoshikawa; K. M. Young; M. C. Zarnstorff; S. J. Zweben

1990-01-01

338

Protein transduction domain-hA20 fusion protein protects endothelial cells against high glucose-induced injury.  

PubMed

We constructed a plasmid containing a protein transduction domain (PTD) and a human A20 (hA20) gene fragment; the fusion protein was obtained by highly expressing this plasmid in the yeast Pichia pastoris GS115. The plasmid was obtained by adding 9xArg and EcoR? recognition sites to the end of the primer, and 6xHis-Tag and Not? recognition sites to its end. After sequencing, the hA20 gene fragment was inserted into plasmid pPIC9k to construct expression vector pPIC9k-PTD-hA20; then, we transfected GS115 with the vector and induced PTD-hA20 protein expression. We purified protein from the yeast fermentation supernatant using a nickel column. Human umbilical vein endothelial cells (HUVECs) were cultured in high glucose medium (30 mM glucose) and in high glucose medium containing different concentrations of protein. Apoptosis of HUVECs was assayed by TUNEL 72 h later. The biological activity tests indicated that the fusion protein not only passed through the cell membrane freely, but also inhibited apoptosis of HUVECs induced by high glucose levels. We conclude that the fusion protein PTD-hA20 has potential for clinical use. PMID:22869545

Hou, C L; Huang, Q; Wei, Y; Zhang, W; Mi, J H; Ying, D J; Zhou, Z H

2012-01-01

339

A NATIONAL COLLABORATORY TO ADVANCE THE SCIENCE OF HIGH TEMPERATURE PLASMA PHYSICS FOR MAGNETIC FUSION  

SciTech Connect

This report summarizes the work of the University of Utah, which was a member of the National Fusion Collaboratory (NFC) Project funded by the United States Department of Energy (DOE) under the Scientific Discovery through Advanced Computing Program (SciDAC) to develop a persistent infrastructure to enable scientific collaboration for magnetic fusion research. A five year project that was initiated in 2001, it the NFC built on the past collaborative work performed within the U.S. fusion community and added the component of computer science research done with the USDOE Office of Science, Office of Advanced Scientific Computer Research. The project was itself a collaboration, itself uniting fusion scientists from General Atomics, MIT, and PPPL and computer scientists from ANL, LBNL, and Princeton University, and the University of Utah to form a coordinated team. The group leveraged existing computer science technology where possible and extended or created new capabilities where required. The complete finial report is attached as an addendum. The In the collaboration, the primary technical responsibility of the University of Utah in the collaboration was to develop and deploy an advanced scientific visualization service. To achieve this goal, the SCIRun Problem Solving Environment (PSE) is used on FusionGrid for an advanced scientific visualization service. SCIRun is open source software that gives the user the ability to create complex 3D visualizations and 2D graphics. This capability allows for the exploration of complex simulation results and the comparison of simulation and experimental data. SCIRun on FusionGrid gives the scientist a no-license-cost visualization capability that rivals present day commercial visualization packages. To accelerate the usage of SCIRun within the fusion community, a stand-alone application built on top of SCIRun was developed and deployed. This application, FusionViewer, allows users who are unfamiliar with SCIRun to quickly create visualizations and perform analysis of their simulation data from either the MDSplus data storage environment or from locally stored HDF5 files. More advanced tools for visualization and analysis also were created in collaboration with the SciDAC Center for Extended MHD Modeling. Versions of SCIRun with the FusionViewer have been made available to fusion scientists on the Mac OS X, Linux, and other Unix based platforms and have been downloaded 1163 times. SCIRun has been used with NIMROD, M3D, BOUT fusion simulation data as well as simulation data from other SciDAC application areas (e.g., Astrophysics). The subsequent visualization results - including animations - have been incorporated into invited talks at multiple APS/DPP meetings as well as peer reviewed journal articles. As an example, SCIRun was used for the visualization and analysis of a NIMROD simulation of a disruption that occurred in a DIII-D experiment. The resulting animations and stills were presented as part of invited talks at APS/DPP meetings and the SC04 conference in addition to being highlighted in the NIH/NSF Visualization Research Challenges Report. By achieving its technical goals, the University of Utah played a key role in the successful development of a persistent infrastructure to enable scientific collaboration for magnetic fusion research. Many of the visualization tools developed as part of the NFC continue to be used by Fusion and other SciDAC application scientists and are currently being supported and expanded through follow-on up on SciDAC projects (Visualization and Analytics Center for Enabling Technology, and the Visualization and Analysis in Support of Fusion SAP).

Allen R. Sanderson; Christopher R. Johnson

2006-08-01

340

A PARALLEL-PROPAGATING ALFVENIC ION-BEAM INSTABILITY IN THE HIGH-BETA SOLAR WIND  

SciTech Connect

We investigate the conditions under which parallel-propagating Alfven/ion-cyclotron waves are driven unstable by an isotropic (T{sub {alpha}} = T{sub Parallel-To {alpha}}) population of alpha particles drifting parallel to the magnetic field at an average speed U{sub {alpha}} with respect to the protons. We derive an approximate analytic condition for the minimum value of U{sub {alpha}} needed to excite this instability and refine this result using numerical solutions to the hot-plasma dispersion relation. When the alpha-particle number density is {approx_equal} 5% of the proton number density and the two species have similar thermal speeds, the instability requires that {beta}{sub p} {approx}> 1, where {beta}{sub p} is the ratio of the proton pressure to the magnetic pressure. For 1 {approx}< {beta}{sub p} {approx}< 12, the minimum U{sub {alpha}} needed to excite this instability ranges from 0.7v{sub A} to 0.9v{sub A}, where v{sub A} is the Alfven speed. This threshold is smaller than the threshold of {approx_equal} 1.2v{sub A} for the parallel magnetosonic instability, which was previously thought to have the lowest threshold of the alpha-particle beam instabilities at {beta}{sub p} {approx}> 0.5. We discuss the role of the parallel Alfvenic drift instability for the evolution of the alpha-particle drift speed in the solar wind. We also analyze measurements from the Wind spacecraft's Faraday cups and show that the U{sub {alpha}} values measured in solar-wind streams with T{sub {alpha}} Almost-Equal-To T{sub Parallel-To {alpha}} are approximately bounded from above by the threshold of the parallel Alfvenic instability.

Verscharen, Daniel; Bourouaine, Sofiane; Chandran, Benjamin D. G. [Space Science Center, University of New Hampshire, Durham, NH 03824 (United States); Maruca, Bennett A., E-mail: daniel.verscharen@unh.edu, E-mail: s.bourouaine@unh.edu, E-mail: benjamin.chandran@unh.edu, E-mail: bmaruca@ssl.berkeley.edu [Space Science Laboratory, University of California, Berkeley, CA 94720 (United States)

2013-08-10

341

TOPICAL REVIEW: Development of high-current high-field conductors in Europe for fusion application  

NASA Astrophysics Data System (ADS)

In the framework of the preparation for the realization of the international thermonuclear experimental reactor (ITER), the construction and test of relevant models of seven different parts of the reactor was decided. Two of them are related to the superconducting coils: the toroidal field model coil (TFMC) and the central solenoid model coil (CSMC). For these superconducting coils, due to the expected high values of the current (?60 kA) and voltage (?5 kV with respect to the ground) the adopted technology was that of cable in conduit conductor (CICC). Until recently, little experience of this technology existed. Therefore, an extensive research and development programme has been carried out, in the last 10 years, by the ITER partners and particularly in Europe, to design, industrialize and test these large conductors and their joints. The EURATOM associations CEA and ENEA played a leading part in this phase. The CICC concept is described and the results of the developments are presented. About 7 km of conductors were manufactured in the industry and for that more than 10 tonnes of Nb3Sn strands were produced in Europe. In this large programme, Europe is particularly in charge of the TFMC, which will be tested this summer at Forschung Zentrum Karlsruhe (Germany). In the framework of this programme, three full size conductors and joint samples were tested at the European Sultan test facility (Centre de Recherches de Physique des Plasmas, Villigen, Switzerland), to validate the technological choices and check that the ITER specifications were met. The results of these tests are presented in detail. Starting from the strand critical properties, the conductors made of about 1000 strands did reach their expected performance. The joints of these large conductors are very special and delicate components. Their behaviour was quite successful and the joint resistance of these samples (of the order of 1 n?) was well within the specifications.

Duchateau, J.-L.; Spadoni, M.; Salpietro, E.; Ciazynski, D.; Ricci, M.; Libeyre, P.; della Corte, A.

2002-06-01

342

Progress in EBW Current Drive Research Towards Enabling Sustained High Beta, Solenoid-Free Operation on NSTX  

NASA Astrophysics Data System (ADS)

Off-axis rf-driven current can play a critical role in sustaining high beta spherical torus (ST) plasmas without a central solenoid. Numerical modeling of electron Bernstein wave current drive (EBWCD) for a beta 40% ST plasma predicts efficient, EBWCD at r/a > 0.5 where the large trapped electron fraction provides favorable conditions for Ohkawa EBWCD. Normalized EBWCD efficiency increases with r/a and is a factor of two higher at r/a = 0.7 than has been obtained with ECCD near the axis of large aspect ratio Tokamaks. Calculations predict 3-4 MW of 28 GHz RF power would maintain the 100 kA off-axis current needed to stabilize a beta 40% plasma. Modeling shows that efficient coupling to EBWs can be readily accomplished using near-circularly polarized electromagnetic waves via an ``O-X-B" oblique launch to the confining magnetic field. Initial measurements of EBW emission support pursuing this approach.

Taylor, G.; Efthimion, P. C.; Kessel, C. E.; Bell, G. L.; Bigelow, T. S.; Carter, M. D.; Caughman, J. B.; Jaeger, F.; Rasmussen, D. A.; Wilgen, J. B.; Harvey, R. W.; Forest, C. B.

2004-11-01

343

Waste minimization through high-pressure microwave digestion of soils for gross {alpha}/{beta} analyses  

SciTech Connect

As a result of the U.S. Department of Energy`s (DOE) environmental restoration and waste management activities, laboratories receive numerous analytical requests for gross {alpha}/{beta} analyses. Traditional sample preparation methods for gross {alpha}/{beta} analysis of environmental and mixed waste samples require repetitive leaching, which is time consuming and generates large volumes of secondary wastes. An alternative to leaching is microwave digestion. In the past. microwave technology has had limited application in the radiochemical laboratory because of restrictions on sample size resulting from vessel pressure limitations. However, new microwave vessel designs allow for pressures on the order of 11 MPa (1500 psi). A procedure is described in which microwave digestion is used to prepare environmental soil samples for gross {alpha}/{beta} analysis. Results indicate that the described procedure meets performance requirements for several soil types and is equivalent to traditional digestion techniques. No statistical differences at the 95% confidence interval exist between the measurement on samples prepared from the hot plate and microwave digestion procedures for those soils tested. Moreover, microwave digestion allows samples to be prepared in a fraction of the time with significantly less acid and with lower potential of cross-contamination. In comparison to the traditional hot plate method, the waste volumes required for the microwave procedure are a factor of 10 lower, while the analyst time for sample processing is at least a factor of three lower.

Yaeger, J.S.; Smith, L.L.

1995-04-01

344

Development and characterization of a Z-pinch-driven hohlraum high-yield inertial confinement fusion target concept  

Microsoft Academic Search

Initial experiments to study the Z-pinch-driven hohlraum high-yield inertial confinement fusion (ICF) concept of Hammer, Tabak, and Porter [Hammer &etal;, Phys. Plasmas 6, 2129 (1999)] are described. The relationship between measured pinch power, hohlraum temperature, and secondary hohlraum coupling (hohlraum energetics) is well understood from zero-dimensional semianalytic, and two-dimensional view factor and radiation magnetohydrodynamics models. These experiments have shown the

Michael E. Cuneo; Roger A. Vesey; John L. Porter; Gordon A. Chandler; David L. Fehl; Terrance L. Gilliland; David L. Hanson; John S. McGurn; Paul G. Reynolds; Laurence E. Ruggles; Hans Seamen; Rick B. Spielman; Ken W. Struve; William A. Stygar; Walter W. Simpson; Jose A. Torres; David F. Wenger; James H. Hammer; Peter W. Rambo; Darrell L. Peterson; George C. Idzorek

2001-01-01

345

Development and characterization of a Z-pinch-driven hohlraum high-yield inertial confinement fusion target concept  

Microsoft Academic Search

Initial experiments to study the Z-pinch-driven hohlraum high-yield inertial confinement fusion (ICF) concept of Hammer, Tabak, and Porter [Hammer et al., Phys. Plasmas 6, 2129 (1999)] are described. The relationship between measured pinch power, hohlraum temperature, and secondary hohlraum coupling (``hohlraum energetics'') is well understood from zero-dimensional semianalytic, and two-dimensional view factor and radiation magnetohydrodynamics models. These experiments have shown

Michael E. Cuneo; Roger A. Vesey; John L. Porter; Gordon A. Chandler; David L. Fehl; Terrance L. Gilliland; David L. Hanson; John S. McGurn; Paul G. Reynolds; Laurence E. Ruggles; Hans Seamen; Rick B. Spielman; Ken W. Struve; William A. Stygar; Walter W. Simpson; Jose A. Torres; David F. Wenger; James H. Hammer; Peter W. Rambo; Darrell L. Peterson; George C. Idzorek

2001-01-01

346

Demonstration of Radiation Pulse Shaping with Nested-Tungsten-Wire-Array Z Pinches for High-Yield Inertial Confinement Fusion  

Microsoft Academic Search

Nested wire-array Z pinches are shown to generate soft x-ray radiation pulse shapes required for three-shock isentropic compression and hot-spot ignition of high-yield inertial confinement fusion capsules. We demonstrate a reproducible and tunable foot pulse (first shock) produced by interaction of the outer and inner arrays. A first-step pulse (second shock) is produced by inner array collision with a central

M. E. Cuneo; R. A. Vesey; D. B. Sinars; E. M. Waisman; R. W. Lemke; D. E. Bliss; W. A. Stygar; J. L. Porter; M. G. Mazarakis; G. A. Chandler; T. A. Mehlhorn; J. P. Chittenden; S. V. Lebedev; D. G. Schroen

2005-01-01

347

High expression of the evolutionarily conserved alpha/beta hydrolase domain containing 6 (ABHD6) in Ewing tumors.  

PubMed

Despite improvements in the treatment of patients with Ewing family tumors (EFT), the prognosis for patients with advanced disease is still unsatisfactory. Recently, we identified lipase I as an EFT-associated gene that might be interesting for the development of new immunological or pharmacological treatment strategies. Lipase I is a member of the large protein superfamilies of alpha/beta hydrolases and serine hydrolases. In the present paper we describe high expression of another member of these superfamilies in EFT. By DNA microarray data base mining we found exceptional high expression of alpha/beta hydrolase domain containing 6 (ABHD6) in EFT but not in other sarcomas. Expression of ABHD6 in EFT correlated with expression of another EFT-associated gene, aristaless. Analysis of ABHD6-associated GGAA microsatellites revealed shorter microsatellites in EFT with lack of ABHD6 expression. ABHD6 homologues were found in varying chordata but not in other animal species. Based on homology modeling we predicted the 3D-structure of ABHD6, which shows high similarity with bacterial homoserine transacetylases. High expression of ABHD6 in EFT in comparison to normal tissues and other tumors suggests that ABHD6 might be an interesting new diagnostic or therapeutic target for EFT. However, knock down of ABHD6 in EFT cells did not inhibit tumor cell growth. PMID:19793082

Max, Daniela; Hesse, Manuela; Volkmer, Ines; Staege, Martin S

2009-12-01

348

High quality multi-focus image fusion using self-similarity and depth information  

NASA Astrophysics Data System (ADS)

Due to the limited depth of field in a camera, some imaging objects will be blurred if they are located far from the focus plane and the other objects on the plane will be clear. Multi-focus image fusion synthesizes a sharp image from multiple partially focused images. However, traditional fused images usually suffer from blurring effects and pixel distortions. In this paper, we explore two unique characteristics of multi-focus images: (1) The self-similarity of a single image and the shared similarity among multiple source images; (2) The distances from object to focal plane. The former characteristic is used to identify image structure-driven regions while the latter refine the image clarity by automatically estimating depth information of blurred images. Experimental results demonstrate that the proposed method outperforms the state-of-the-art fusion methods on image quality and objective fusion criteria.

Guo, Di; Yan, Jingwen; Qu, Xiaobo

2015-03-01

349

Stimulated scattering in laser driven fusion and high energy density physics experiments  

NASA Astrophysics Data System (ADS)

In laser driven fusion and high energy density physics experiments, one often encounters a k?D range of 0.15 < k?D < 0.5, where stimulated Raman scattering (SRS) is active (k is the initial electron plasma wave number and ?D is the Debye length). Using particle-in-cell simulations, the SRS reflectivity is found to scale as (k?D)-4 for k?D ? 0.3 where electron trapping effects dominate SRS saturation; the reflectivity scaling deviates from the above for k?D < 0.3 when Langmuir decay instability (LDI) is present. The SRS risk is shown to be highest for k?D between 0.2 and 0.3. SRS re-scattering processes are found to be unimportant under conditions relevant to ignition experiments at the National Ignition Facility (NIF). Large-scale simulations of the hohlraum plasma show that the SRS wavelength spectrum peaks below 600 nm, consistent with most measured NIF spectra, and that nonlinear trapping in the presence of plasma gradients determines the SRS spectral peak. Collisional effects on SRS, stimulated Brillouin scattering (SBS), LDI, and re-scatter, together with three dimensional effects, are examined. Effects of collisions are found to include de-trapping as well as cross-speckle electron temperature variation from collisional heating, the latter of which reduces gain, introduces a positive frequency shift that counters the trapping-induced negative frequency shift, and affects SRS and SBS saturation. Bowing and breakup of ion-acoustic wavefronts saturate SBS and cause a dramatic, sharp decrease in SBS reflectivity. Mitigation of SRS and SBS in the strongly nonlinear trapping regime is discussed.

Yin, L.; Albright, B. J.; Rose, H. A.; Montgomery, D. S.; Kline, J. L.; Kirkwood, R. K.; Milovich, J.; Finnegan, S. M.; Bergen, B.; Bowers, K. J.

2014-09-01

350

Achievement of High Fusion Performance in JT-60U Reversed Shear Discharges  

NASA Astrophysics Data System (ADS)

Fusion performance of reversed shear discharges with an L-mode edge has been significantly improved in a thermonuclear dominant regime with up to 2.8 MA of plasma current in the JT-60U tokamak. The core plasma energy is efficiently confined due to the existence of persistent internal transport barriers formed for both ions and electrons at a large minor radius of r/a~0.7 near the boundary of the reversed shear region. In an assumed deuterium-tritium fuel, the peak fusion amplification factor defined for transient conditions involving the dW/dt term would be in excess of unity.

Ishida, S.; Fujita, T.; Akasaka, H.; Akino, N.; Annou, K.; Aoyagi, T.; Arai, T.; Arakawa, K.; Asakura, N.; Azumi, M.; Budny, R.; Chiba, S.; da Costa, O.; Ebisawa, N.; Fujii, T.; Fukuda, T.; Funahashi, A.; Grisham, L.; Gunji, S.; Hamamatsu, K.; Hasegawa, Y.; Hatae, T.; Higashijima, S.; Hiratsuka, H.; Hirauchi, S.; Hirayama, T.; Honda, A.; Honda, M.; Hosogane, N.; Ichige, H.; Ide, S.; Ikeda, Y.; Isaka, M.; Isayama, A.; Isei, N.; Ishii, Y.; Isozaki, N.; Itami, K.; Itoh, T.; Iwahashi, T.; Kamada, Y.; Kaminaga, A.; Kashiwabara, T.; Kawai, M.; Kawamata, Y.; Kawano, Y.; Kazama, D.; Kazawa, M.; Kikuchi, M.; Kimura, H.; Kimura, T.; Kishimoto, H.; Kishimoto, Y.; Kitamura, S.; Kiyono, K.; Kodama, K.; Koide, Y.; Kokusen, S.; Kondoh, T.; Konoshima, S.; Koog, J.; Kramer, G. J.; Kubo, H.; Kurihara, K.; Kurita, G.; Kuriyama, M.; Kusama, Y.; Masaki, K.; Matsuda, T.; Matsumoto, T.; Matukawa, M.; Miura, T.; Miya, N.; Miyachi, K.; Miyata, H.; Miyo, Y.; Mogaki, K.; Mori, M.; Morimoto, M.; Morioka, S.; Moriyama, S.; Nagami, M.; Nagashima, A.; Nagashima, K.; Nagaya, S.; Naito, O.; Nakamura, Y.; Nemoto, M.; Neyatani, Y.; Nishitani, T.; Ogiwara, N.; Ohga, T.; Ohsawa, M.; Ohshima, T.; Oikawa, T.; Okabe, T.; Okano, J.; Omori, K.; Omori, S.; Omori, Y.; Onose, Y.; Oohara, H.; Ozeki, T.; Saidoh, M.; Saigusa, M.; Saito, N.; Sakasai, A.; Sakata, S.; Sakurai, S.; Sasajima, T.; Sato, M.; Scott, S. D.; Seimiya, M.; Seiki, H.; Seki, M.; Shimada, M.; Shimizu, K.; Shimizu, M.; Shimono, M.; Shinozaki, S.; Shirai, H.; Shitomi, M.; Suganuma, K.; Sugie, T.; Sunaoshi, H.; Takahashi, M.; Takahashi, S.; Takeji, S.; Takenaga, H.; Takizuka, T.; Tamai, H.; Terakado, M.; Terakado, T.; Tobita, K.; Tokuda, S.; Totsuka, T.; Toyokawa, Y.; Toyoshima, N.; Tsuchiya, K.; Tsugita, T.; Tsukahara, Y.; Tuda, T.; Uramoto, Y.; Ushigusa, K.; Usui, K.; Yagyu, J.; Yamagiwa, M.; Yamamoto, M.; Yamamoto, T.; Yamashita, O.; Yokokura, K.; Yoshida, H.; Yoshida, M.; Yoshino, R.

1997-11-01

351

Highly toxic and broad-spectrum insecticidal local Bacillus strains engineered using protoplast fusion.  

PubMed

Protoplast fusion was performed between a local Bacillus thuringiensis UV-resistant mutant 66/1a (Bt) and Bacillus sphaericus GHAI (Bs) to produce new Bacillus strains with a wider spectrum of action against different insects. Bt is characterized as sensitive to polymyxin and streptomycin and resistant to rifampicin and has shown 87% mortality against Spodoptera littoralis larvae at concentration of 1.5 10(7) cells/mL after 7 days of feeding; Bs is characterized as resistant to polymyxin and streptomycin and sensitive to rifampicin and has been shown to have 100% mortality against Culex pipiens after 1 day of feeding at the same concentration as that of Bt. Among a total of 64 Bt::Bs fusants produced on the selective medium containing polymyxin, streptomycin, and rifampicin, 17 fusants were selected because of their high mortality percentages against S. littoralis (Lepidoptera) and C. pipiens (Diptera). While Bt harboured 3 plasmids (600, 350, and 173 bp) and Bs had 2 plasmids (544 and 291 bp), all the selected fusants acquired plasmids from both parental strains. SDS-PAGE protein analysis of the 17 selected fusants and their parental strains confirmed that all fusant strains acquired and expressed many specific protein bands from the 2 parental strains, especially the larvicidal proteins to both lepidopteran and dipteran species with molecular masses of 65, 70, 80, 88, 100, and 135 kDa. Four protein bands with high molecular masses of 281, 263, 220, and 190 kDa, which existed in the Bt parental strain and did not exist in the Bs parental strain, and 2 other protein bands with high molecular masses of 185 and 180 kDa, which existed in the Bs parental strain and did not exist in the Bt parental strain, were expressed in most fusants. The results indicated the expression of some cry genes encoded for insecticidal crystal proteins from Bt and the binary toxin genes from Bs in all fusant strains. The recombinant fusants have more efficient and potential values for agricultural application compared with both the insecticidal Bt and the mosquitocidal Bs strains alone against S. littoralis and C. pipiens larvae, respectively. PMID:25485592

El-Kawokgy, Tahany M A; Hussein, Hashem A; Aly, Nariman A H; Mohamed, Shereen A H

2015-01-01

352

High level transient production of recombinant antibodies and antibody fusion proteins in HEK293 cells  

PubMed Central

Background The demand of monospecific high affinity binding reagents, particularly monoclonal antibodies, has been steadily increasing over the last years. Enhanced throughput of antibody generation has been addressed by optimizing in vitro selection using phage display which moved the major bottleneck to the production and purification of recombinant antibodies in an end-user friendly format. Single chain (sc)Fv antibody fragments require additional tags for detection and are not as suitable as immunoglobulins (Ig)G in many immunoassays. In contrast, the bivalent scFv-Fc antibody format shares many properties with IgG and has a very high application compatibility. Results In this study transient expression of scFv-Fc antibodies in human embryonic kidney (HEK) 293 cells was optimized. Production levels of 10-20mg/L scFv-Fc antibody were achieved in adherent HEK293T cells. Employment of HEK293-6E suspension cells expressing a truncated variant of the Epstein Barr virus (EBV) nuclear antigen (EBNA) 1 in combination with production under serum free conditions increased the volumetric yield up to 10-fold to more than 140mg/L scFv-Fc antibody. After vector optimization and process optimization the yield of an scFv-Fc antibody and a cytotoxic antibody-RNase fusion protein further increased 3-4-fold to more than 450mg/L. Finally, an entirely new mammalian expression vector was constructed for single step in frame cloning of scFv genes from antibody phage display libraries. Transient expression of more than 20 different scFv-Fc antibodies resulted in volumetric yields of up to 600mg/L and 400mg/L in average. Conclusion Transient production of recombinant scFv-Fc antibodies in HEK293-6E in combination with optimized vectors and fed batch shake flasks cultivation is efficient and robust, and integrates well into a high-throughput recombinant antibody generation pipeline. PMID:23802841

2013-01-01

353

The National Spherical Torus Experiment (NSTX) research programme and progress towards high beta, long pulse operating scenarios.  

SciTech Connect

A major research goal of the national spherical torus experiment is establishing long-pulse, high beta, high confinement operation and its physics basis. This research has been enabled by facility capabilities developed during 2001 and 2002, including neutral beam (up to 7 MW) and high harmonic fast wave (HHFW) heating (up to 6 MW), toroidal fields up to 6 kG, plasma currents up to 1.5 MA, flexible shape control, and wall preparation techniques. These capabilities have enabled the generation of plasmas with {beta}{sub T} {triple_bond}

/(B{sub T0}{sup 2}/2{mu}{sub 0}) of up to 35%. Normalized beta values often exceed the no-wall limit, and studies suggest that passive wall mode stabilization enables this for H mode plasmas with broad pressure profiles. The viability of long, high bootstrap current fraction operations has been established for ELMing H mode plasmas with toroidal beta values in excess of 15% and sustained for several current relaxation times. Improvements in wall conditioning and fueling are likely contributing to a reduction in H mode power thresholds. Electron thermal conduction is the dominant thermal loss channel in auxiliary heated plasmas examined thus far. HHFW effectively heats electrons, and its acceleration of fast beam ions has been observed. Evidence for HHFW current drive is obtained by comparison of the loop voltage evolution in plasmas with matched density and temperature profiles but varying phases of launched HHFW waves. Studies of emissions from electron Bernstein waves indicate a density scale length dependence of their transmission across the upper hybrid resonance near the plasma edge that is consistent with theoretical predictions. A peak heat flux to the divertor targets of 10 MW m{sup -2} has been measured in the H mode, with large asymmetries being observed in the power deposition between the inner and outer strike points. Non-inductive plasma startup studies have focused on coaxial helicity injection. With this technique, toroidal currents up to 400 kA have been driven, and studies to assess flux closure and coupling to other current drive techniques have begun.

Johnson, D.W. (Princeton University, Princeton, NJ); Grisham, L.R. (Princeton University, Princeton, NJ); Zweben, S. J. (Princeton University, Princeton, NJ); Gates, D.A. (Princeton University, Princeton, NJ); Bush, C. (Oak Ridge National Laboratory, Oak Ridge, TN); Synakowski, E.J. (Princeton University, Princeton, NJ); Hosea, J. C. (Princeton University, Princeton, NJ); Blanchard, W. (Princeton University, Princeton, NJ); Bell, Michael G. (Princeton University, Princeton, NJ); Sabbagh, S. (Columbia University, New York, NY); Soukhanovskii, V. (Princeton University, Princeton, NJ); Raman, R. (University of Washington, Seattle, WA,); Peng, Y-K. M. (Oak Ridge National Laboratory, Oak Ridge, TN); Ono, M. (Princeton University, Princeton, NJ); Stevenson, T. (Princeton University, Princeton, NJ); Fredrickson, E. D. (Princeton University, Princeton, NJ); Kubota, Shigeru (University of California, Los Angeles, CA); Efthimion, P. C. (Princeton University, Princeton, NJ); Bourdelle, C. (CEA Cadarache, France); Wilson, J.R. (Princeton University, Princeton, NJ); Maqueda, R. (Los Alamos National Laboratory, Los Alamos, NM); Kaye, S. M. (Princeton University, Princeton, NJ); Kaita, R. (Princeton University, Princeton, NJ); Maingi, R. (Oak Ridge National Laboratory, Oak Ridge, TN); Darrow, D. S. (Princeton University, Princeton, NJ); Bitter, M. (Princeton University, Princeton, NJ); Kugel, Henry W. (Princeton University, Princeton, NJ); Skinner, C. H. (Princeton University, Princeton, NJ); Wilgen, J. (Oak Ridge National Laboratory, Oak Ridge, TN); Von Halle, A. (Princeton University, Princeton, NJ); Taylor, G. (Princeton University, Princeton, NJ); Mueller, D. (Princeton University, Princeton, NJ); Swain, D. W. (Oak Ridge National Laboratory, Oak Ridge, TN); Ryan, P.M. (Oak Ridge National Laboratory, Oak Ridge, TN); Rosenberg, A. (Princeton University, Princeton, NJ); Ramakrishnan, S. (Princeton University, Princeton, NJ); Phillips, C.K. (Princeton University, Princeton, NJ); Paul, S. (Princeton University, Princeton, NJ); Park, H.K. (Princeton University, Princeton, NJ); Paoletti, F. (Columbia University, New York, NY); Boedo, J. (University of California, San Diego, CA); Williams, M. (Princeton University, Princeton, NJ); Gilmore, Mark A. (University of New Mexico, Albuquerque, NM); LeBlanc, B. (Princeton University, Princeton, NJ); Bigelow, T. (Oak Ridge National Laboratory, Oak Ridge, TN); Bell, R. E. (Princeton University, Princeton, NJ); Roquemore, A. L. (Princeton University, Princeton, NJ); Wampler, William R.; Medley, S. S. (Princeton University, Princeton, NJ); Stutman, D. (Johns Hopkins University, Baltimore, MD); Menard, J. (Princeton University, Princeton, NJ); Mazzucato, E. (Princeton University, Princeton, NJ); Neumeyer, C. (Princeton University, Princeton, NJ); Nelson, B.A. (University of Washington, Seattle, WA); Lee, K. (University of California, Davis, CA); Manickam, J. (Princeton University, Princeton, NJ)

2004-06-01

354

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

E-print Network

The affordable, robust, compact (ARC) reactor conceptual design study 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, which have joints to enable disassembly. This allows the vacuum vessel to be replaced quickly, mitigating first wall survivability concerns, and permits a single device to test many vacuum vessel designs and divertor materials. The design point has a plasma fusion gain of Q_p~13.6, yet is fully non-inductive, with a modest bootstrap fraction of only ~63%. Thus ARC offers a high power gain with relatively large external control of the current profile. This highly attractive combination is enabled by the ~23 T peak field on coil with newly available REBCO superconductor technology. External cu...

Sorbom, B N; Palmer, T R; Mangiarotti, F J; Sierchio, J M; Bonoli, P; Kasten, C; Sutherland, D A; Barnard, H S; Haakonsen, C B; Goh, J; Sung, C; Whyte, D G

2014-01-01

355

Highly Potent, Water Soluble Benzimidazole Antagonist for Activated (alpha)4(beta)1 Integrin  

SciTech Connect

The cell surface receptor {alpha}{sub 4}{beta}{sub 1} integrin, activated constitutively in lymphoma, can be targeted with the bisaryl urea peptidomimetic antagonist 1 (LLP2A). However, concerns on its preliminary pharmacokinetic (PK) profile provided an impetus to change the pharmacophore from a bisaryl urea to a 2-arylaminobenzimidazole moiety resulting in improved solubility while maintaining picomolar potency [5 (KLCA4); IC{sub 50} = 305 pM]. With exceptional solubility, this finding has potential for improving PK to help diagnose and treat lymphomas.

Carpenter, R D; Andrei, M; Lau, E Y; Lightstone, F C; Liu, R; Lam, K S; Kurth, M J

2007-08-29

356

Highly stable beta-class carbonic anhydrases useful in carbon capture systems  

SciTech Connect

The present disclosure relates to .beta.-class carbonic anhydrase polypeptides having improved properties including increased thermostability and/or stability in the presence of amine compounds, ammonia, or carbonate ion. The present disclosure also provides formulations and uses of the polypeptides for accelerating the absorption of carbon dioxide from a gas stream into a solution as well as for the release of the absorbed carbon dioxide for further treatment and/or sequestering. Also provided are polynucleotides encoding the carbonic anhydrase polypeptides and host cells capable of expressing them.

Alvizo, Oscar; Benoit, Michael R; Novick, Scott J

2013-08-20

357

Highly stable beta-class carbonic anhydrases useful in carbon capture systems  

SciTech Connect

The present disclosure relates to .beta.-class carbonic anhydrase polypeptides having improved properties including increased thermostability and/or stability in the presence of amine compounds, ammonia, or carbonate ion. The present disclosure also provides formulations and uses of the polypeptides for accelerating the absorption of carbon dioxide from a gas stream into a solution as well as for the release of the absorbed carbon dioxide for further treatment and/or sequestering. Also provided are polynucleotides encoding the carbonic anhydrase polypeptides and host cells capable of expressing them.

Alvizo, Oscar; Benoit, Mike; Novick, Scott

2013-04-16

358

Lateral Lumbar Interbody Fusion for the Correction of Spondylolisthesis and Adult Degenerative Scoliosis in High-Risk Patients: Early Radiographic Results and Complications  

PubMed Central

Background Lateral lumbar interbody fusion (LLIF) is not associated with many of the complications seen in other interbody fusion techniques. This study used computed tomography (CT) scans, the radiographic gold standard, to assess interbody fusion rates achieved utilizing the LLIF technique in high-risk patients. Methods We performed a retrospective review of patients who underwent LLIF between January 2008 and July 2013. Forty-nine patients underwent nonstaged or staged LLIF on 119 levels with posterior correction and augmentation. Per protocol, patients received CT scans at their 1-year follow-up. Of the 49 patients, 21 patients with LLIF intervention on 54 levels met inclusion criteria. Two board-certified musculoskeletal radiologists and the senior surgeon (JZ) assessed fusion. Results Of the 21 patients, 6 patients had had previous lumbar surgery, and the cohort's comorbidities included osteoporosis, diabetes, obesity, and smoking, among others. Postoperative complications occurred in 12 (57.1%) patients and included anterior thigh pain and weakness in 6 patients, all of which resolved by 6 months. Two cases of proximal junctional kyphosis occurred, along with 1 case of hardware pullout. Two cases of abdominal atonia occurred. By CT scan assessment, each radiologist found fusion was achieved in 53 of 54 levels (98%). The radiologists' findings were in agreement with the senior surgeon. Conclusion Several studies have evaluated LLIF fusion and reported fusion rates between 88%-96%. Our results demonstrate high fusion rates using this technique, despite multiple comorbidities in the patient population. Spanning the ring apophysis with large LLIF cages along with supplemental posterior pedicle screw augmentation can enhance stability of the fusion segment and increase fusion rates. PMID:24688329

Waddell, Brad; Briski, David; Qadir, Rabah; Godoy, Gustavo; Houston, Allison Howard; Rudman, Ernest; Zavatsky, Joseph

2014-01-01

359

High efficiency covalent radiolabeling of the human androgen receptor. Studies in cultured fibroblasts using dihydrotestosterone 17 beta-bromoacetate.  

PubMed Central

Analysis of mutations affecting the androgen receptor protein in human cells has been limited because of the low abundance and lability of these proteins in target tissues. All methods used to date have been based on the noncovalent interaction of radiolabeled androgens with the receptor's ligand binding site. We report here synthesis and use of the electrophilic affinity label dihydrotestosterone 17 beta-bromoacetate. This ligand, prepared as a radioactive compound of high specific activity, rapidly and covalently binds to a protein of 58,000 daltons in cytosol from normal genital skin fibroblasts. This protein is a high affinity, saturable specific binding site for the ligand and was not detectable in cultured cells from a subject with androgen resistance or in receptor-negative nongenital fibroblasts. The efficiency of incorporation of the covalent radiolabel into the 58-kD protein is greater than 80% based on estimates of receptor content using noncovalent ligands in intact cell assays. These studies demonstrate that dihydrotestosterone 17 beta-bromoacetate is useful for high efficiency covalent labeling of the human androgen receptor in crude cytosolic extracts from cultured cells. Images PMID:3339123

Kovacs, W J; Turney, M K

1988-01-01

360

Finite beta effects on low- and high-frequency magnetosonic waves in a two-ion-species plasma  

SciTech Connect

A magnetosonic wave propagating perpendicular to a magnetic field in a two-ion-species plasma has two branches, high-frequency and low-frequency modes. The finite beta effects on these modes are analyzed theoretically on the basis of the three-fluid model with finite ion and electron pressures. First, it is shown that the Korteweg-de Vries (KdV) equation for the low-frequency mode is valid for amplitudes ?high-frequency mode are derived, including ? as a factor. In addition, the theory for heavy ion acceleration by the high-frequency mode pulse and the pulse damping due to this energy transfer in a finite beta plasma are presented.

Toida, Mieko; Aota, Yukio [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan)] [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan)

2013-08-15

361

High-Dose Continuous Infusion Beta-lactam Antibiotics for the Treatment of Resistant Pseudomonas aeruginosa Infections in Immunocompromised Patients  

PubMed Central

OBJECTIVE To report a case series of high-dose continuous infusion beta-lactam antibiotics for the treatment of resistant Pseudomonas aeruginosa infections. CASE SUMMARY Continuous infusion ceftazidime or aztreonam was administered to achieve target drug levels at or above the MIC when possible in three patients with P. aeruginosa infections. The maximal calculated target drug level was 100 mg/L. In the first patient with primary immunodeficiency, neutropenia, and aggressive cutaneous T cell lymphoma/leukemia, continuous infusion ceftazidime (6.5 to 9.6 g/day) was used to successfully treat multidrug-resistant P. aeruginosa bacteremia. In the second patient with leukocyte adhesion deficiency type 1, continuous infusion aztreonam (8.4 g/day) was used to successfully treat multidrug-resistant P. aeruginosa wound infections. In the third patient with severe aplastic anemia, continuous infusion ceftazidime (7 to 16.8 g/day) was used to treat P. aeruginosa pneumonia and bacteremia. In each patient, the bacteremia cleared, infected wounds healed, and pneumonia improved in response to continuous infusion ceftazidime or aztreonam. DISCUSSION Treatment strategies for multidrug-resistant P. aeruginosa infections are limited. A novel treatment strategy when no other options are available is the administration of existing beta-lactam antibiotics by continuous infusion in order to maximize their pharmacodynamic activity. High-dose continuous infusion ceftazidime or aztreonam was used for the successful treatment of resistant systemic P. aeruginosa infections in three chronically immunocompromised patients. CONCLUSION Continuous infusion beta-lactam antibiotics are a potentially useful treatment strategy for resistant P. aeruginosa infections in immunocompromised patients. PMID:20371747

Moriyama, Brad; Henning, Stacey A.; Childs, Richard; Holland, Steven M.; Anderson, Victoria L.; Morris, John C.; Wilson, Wyndham H.; Drusano, George L.; Walsh, Thomas J.

2011-01-01

362

Linear theory of tearing in a high-beta plasma. [of dayside magnetopause  

NASA Technical Reports Server (NTRS)

The linear dispersion relation for a collisionless plasma in a sheared one-dimensional current sheet is calculated with reference to conditions in the daytime magnetopause. Calculations are extended to include plasmas with beta approximately equal to 1. It is found that the tearing mode eigenstructure and temporal growth rate are a sensitive function of the ratios l sub s/l sub G, l sub s/l sub T, and l sub s/l sub n, where l sub s is the shearing length of the magnetic field, l sub G is the gradient scale length, and l sub T is the temperature gradient scale length. In particular, if beta is approximately equal to 1, and l sub s is less than l sub G, l sub n, and l sub T, then the thickness of the layer over which particles are resonantly accelerated by the induction magnetic field is approximately rho, a thermal gyroradius. If the above conditions are not satisfied, plasma gradients may electrostatically stabilize the mode.

Quest, K. B.; Coroniti, F. V.

1981-01-01

363

High-speed repeating hydrogen pellet injector for long-pulse magnetic confinement fusion experiments  

NASA Astrophysics Data System (ADS)

The projected fueling requirements of future magnetic confinement fusion devices [e.g., the International Thermonuclear Experimental Reactor (ITER)] indicate the need for a flexible plasma fueling capability, including both gas puffing and low- and high-speed pellet injection. Conventional injectors, based on single-stage pneumatic guns or centrifuges, can reliably provide frozen pellets (1- to 6-mm-diam sizes) at speeds up to 1.3 km/s and at suitable repetition rates (1 to 10 Hz or greater). Injectors based on two-stage pneumatic guns and ``in situ'' condensation of hydrogen pellets can reliably achieve velocities over 3 km/s; however, they are not suitable for long-pulse repetitive operations. An experiment in collaboration between Oak Ridge National Laboratory (ORNL) and ENEA Frascati is under way to demonstrate the feasibility of a high-speed (?2 km/s) repeating (1 Hz) pneumatic pellet injector for long-pulse operation. A test facility has been assembled at ORNL, combining a Frascati repeating two-stage light-gas gun and an ORNL deuterium extruder, equipped with a pellet chambering mechanism/gun barrel assembly. The main issues to be investigated were the strength of extruded deuterium ice as opposed to that produced by in situ condensation in pipe guns (hence the highest acceleration which can be given to the pellet without fracturing it), and the maximum repetition rate at which the system can operate without degradation in performance. Pellet velocities of up to 2.55 km/s have been achieved in joint experiments at ORNL. A new pressure tailoring valve was developed by the Frascati group for this application and proved to be a crucial component for good performance. Tests carried out in repeating mode, at frequencies of 0.2-0.5 Hz and speeds up to 2.2 km/s, indicate no significant degradation in performance with increasing repetition rate. Some preliminary tests using 3.7 mm pellets gave very encouraging results. The equipment and the experimental results are described in this article.

Frattolillo, A.; Migliori, S.; Scaramuzzi, F.; Combs, S. K.; Baylor, L. R.; Foust, C. R.; Gouge, M. J.; Milora, S. L.

1996-05-01

364

Insulator materials in high power lasers for inertial fusion: present and future  

SciTech Connect

A summary is given of the important characteristics of currently used insulator materials. Figures of merit for materials needed in future systems are identified. A methodology for identifying and evaluating new materials meeting the stringent performance requirements of future fusion laser systems is outlined.

Krupke, W.F.

1983-11-11

365

High level information fusion for tracking and projection of multistage cyber attacks  

Microsoft Academic Search

The use of computer networks has become a necessity for government, industry, and personal businesses. Protection and defense against cyber attacks on computer networks, however, are becoming inadequate as attackers become more sophisticated and as the networks and systems become more complex. Drawing analogies from other application domains, this paper introduces information fusion to provide situation awareness and threat prediction

Shanchieh J. Yang; Adam Stotz; Jared Holsopple; Moises Sudit; Michael E. Kuhl

2009-01-01

366

QUASI-OPTICAL MODE CONVERTERS IN ADVANCED HIGH-POWER GYROTRONS FOR NUCLEAR FUSION PLASMA HEATING  

Microsoft Academic Search

The R&D activities at the Karlsruhe Research Center (FZK) on advanced highpower millimeter (mm)-wave gyrotrons for future\\u000a use in electron cyclotron heating and current drive (EC H&CD) in magnetically confined fusion plasmas consist of:

M. Thumm; A. Arnold; O. Drumm; J. Jin; G. Michel; B. Piosczyk; T. Rzesnicki; D. Wagner; X. Yang

367

ChemTeacher: Beta Decay  

NSDL National Science Digital Library

ChemTeacher compiles background information, videos, articles, demonstrations, worksheets and activities for high school teachers to use in their classrooms. The Beta Decay page includes resources for teaching students about the discovery and applications of beta decay.

2011-01-01

368

Towards a Radio-guided Surgery with $\\beta^{-}$ Decays: Uptake of a somatostatin analogue (DOTATOC) in Meningioma and High Grade Glioma  

E-print Network

A novel radio guided surgery (RGS) technique for cerebral tumors using $\\beta^{-}$ radiation is being developed. Checking the availability of a radio-tracer that can deliver a $\\beta^{-}$ emitter to the tumor is a fundamental step in the deployment of such technique. This paper reports a study of the uptake of 90Y labeled (DOTATOC) in the meningioma and the high grade glioma (HGG) and a feasibility study of the RGS technique in these cases.

Collamati, Francesco; Bellini, Fabio; Bocci, Valerio; Cremonesi, Marta; De Lucia, Erika; Ferrari, Mahila; Frallicciardi, Paola M; Grana, Chiara M; Marafini, Michela; Mattei, Ilaria; Morganti, Silvio; Patera, Vincenzo; Piersanti, Luca; Recchia, Luigi; Russomando, Andrea; Sarti, Alessio; Sciubba, Adalberto; Senzacqua, Martina; Camillocci, Elena Solfaroli; Voena, Cecilia; Faccini, Riccardo

2014-01-01

369

Signal modeling of high-purity Ge detectors with a small read-out electrode and application to neutrinoless double beta decay search in Ge76  

Microsoft Academic Search

The GERDA experiment searches for the neutrinoless double beta decay of 76Ge using high-purity germanium detectors enriched in 76Ge. The analysis of the signal time structure provides a powerful tool to identify neutrinoless double beta decay events and to discriminate them from gamma-ray induced backgrounds. Enhanced pulse shape discrimination capabilities of Broad Energy Germanium detectors with a small read-out electrode

M. Agostini; C. A. Ur; D. Budjs; E. Bellotti; R. Brugnera; C. M. Cattadori; A. di Vacri; A. Garfagnini; L. Pandola; S. Schnert

2011-01-01

370

In-Situ Time-of-Flight Neutron Diffraction Study of High-Temperature alpha-to- beta Phase Transition in Elemental Scandium  

Microsoft Academic Search

Lattice parameters for both hcp alpha-Sc and bcc beta-Sc were determined between 1200 C and 1400 C from time-of-flight (TOF) neutron diffraction data collected from an elemental Sc sample vacuum sealed inside a niobium crucible. On heating, the high-temperature beta-Sc phase first appeared between 1340 C and 1350 C, close to the reported transition temperature of 1337 C. The lattice

Daniel R. Kammler; Mark A. Rodriguez; Ralph G. Tissot; Donald W. Brown; Bjrn Clausen; Thomas A. Sisneros

2008-01-01

371

Measuring situational awareness and resolving inherent high-level fusion obstacles  

NASA Astrophysics Data System (ADS)

Information Fusion Engine for Real-time Decision Making (INFERD) is a tool that was developed to supplement current graph matching techniques in Information Fusion models. Based on sensory data and a priori models, INFERD dynamically generates, evolves, and evaluates hypothesis on the current state of the environment. The a priori models developed are hierarchical in nature lending them to a multi-level Information Fusion process whose primary output provides a situational awareness of the environment of interest in the context of the models running. In this paper we look at INFERD's multi-level fusion approach and provide insight on the inherent problems such as fragmentation in the approach and the research being undertaken to mitigate those deficiencies. Due to the large variance of data in disparate environments, the awareness of situations in those environments can be drastically different. To accommodate this, the INFERD framework provides support for plug-and-play fusion modules which can be developed specifically for domains of interest. However, because the models running in INFERD are graph based, some default measurements can be provided and will be discussed in the paper. Among these are a Depth measurement to determine how much danger is presented by the action taking place, a Breadth measurement to gain information regarding the scale of an attack that is currently happening, and finally a Reliability measure to tell the user the credibility of a particular hypothesis. All of these results will be demonstrated in the Cyber domain where recent research has shown to be an area that is welldefined and bounded, so that new models and algorithms can be developed and evaluated.

Sudit, Moises; Stotz, Adam; Holender, Michael; Tagliaferri, William; Canarelli, Kathie

2006-04-01

372

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

SciTech Connect

The National Ignition Facility (NIF), currently under construction at the University of California's Lawrence Livermore National Laboratory, is a stadium-sized facility containing a 192-beam, 1.8-Megajoule, 500-Terawatt, 351-nm laser system and a 10-meter diameter target chamber with room for nearly 100 experimental diagnostics. NIF is being built by the National Nuclear Security Administration and when completed will be the world's largest laser experimental system, providing a national center to study inertial confinement fusion and the physics of matter at extreme energy densities and pressures. NIF will provide 192 energetic laser beams that will compress small fusion targets to conditions where they will ignite and burn, liberating more energy than is required to initiate the fusion reactions. NIF experiments will allow the study of physical processes at temperatures approaching 100 million K and 100 billion times atmospheric pressure. These conditions exist naturally only in the interior of stars and in nuclear weapons explosions. In the course of designing the world's most energetic laser system, a number of significant technology breakthroughs have been achieved. Research is also underway to develop a shorter pulse capability on NIF for very high power and extreme electromagnetic field research and applications. We discuss here the technology challenges and solutions that have made NIF possible, along with enhancements to NIF's design that could lead to near-exawatt power levels.

Moses, E I; Wuest, C R

2002-10-16

373

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

SciTech Connect

The National Ignition Facility (NIF), currently under construction at the University of California's Lawrence Livermore National Laboratory is a $2.25B stadium-sized facility containing a 192-beam, 1.8-Megajoule, 500-Terawatt, 351-nm laser system. NIF is being built by the National Nuclear Security Agency and when completed will be the world's largest laser system, providing a national center to study inertial confinement fusion and the physics of extreme energy densities and pressures. In NIF up to 192 energetic laser beams will compress small fusion targets to conditions where they will ignite and burn, liberating more energy than is required to initiate the fusion reactions. NIF experiments will allow the study of physical processes at temperatures approaching 100 million K and 100 billion times atmospheric pressure. These conditions exist naturally only in the interior of stars and in nuclear weapons explosions. In the course of designing the world's most energetic laser system, a number of significant technology breakthroughs have been achieved. Research is also underway to develop a shorter pulse capability on NIF for high power applications. We discuss here the technology challenges and solutions that have made NIF possible along with enhancements to NIF's design that could lead to exawatt power levels.

Moses, E I

2002-01-11

374

Seismic properties of Southalpine metapelite at high temperatures and pressures: revisiting the alpha-beta quartz phase transition  

NASA Astrophysics Data System (ADS)

This work concludes a study started many years ago in the Rock Deformation Laboratory of ETH Zurich, in which the seismic properties (Vp / Vs) of crustal metapelites at high pressure and temperature were characterised. A particular goal was to map the alpha-beta phase transition in quartz-rich rocks, and to link these effects to areas of above average heat flux. Our interest in metapelites is driven by the observation that they are among the most common metamorphic rock types of continental crust and possibly constitute a significant part of lower crust. Metapelites are rich in quartz and hydrous minerals (e.g. biotite, muscovite, chlorite), and are common in the lithology of areas high geothermal activity due to the higher than average heat flux. They are also good candidates to investigate dehydration reactions and phase transitions of the middle to lower crust. To investigate, we employ a 'Paterson' type apparatus that is configured for petrophysical work, in particular elastic wave velocity and electrical conductivity, installed in the Rock Deformation Laboratory at ETH Zurich in 2002. Using this apparatus, we have been able to greatly expand our understanding of the seismic (and inducted seismicity) properties associated with dehydration reactions and phase transitions, simulating in situ conditions in the shallow crust. Here we report new measurements of the seismic properties of a metapelite from the Serie dei Laghi basement (Southern Alps, N-Italy), revealing, for the first time under in-situ conditions, evidence for the alpha-beta transition. P-wave and S-wave elastic wave velocities were measured along the principal anisotropy directions at pressures up to 500 MPa. To observe the effects of the alpha-beta quartz transition under hydrostatic conditions, and additionally of muscovite dehydration, we then monitored P-wave velocity continuously as the sample was heated to 800C, for a range of pressures. At 400 MPa, Vp decreases monotonically with temperature to 675C; then as temperatures continue to increase Vp rapidly increases until 750C. The effect is found to be perfectly reversible, and thus we interpret it as the alpha-beta transition in quartz. We measure a linear trend of the transition with increasing pressure, at a rate equivalent of 0.3 K/MPa, consistent with previous work. We also find evidence that the continuous increase of Vp at elevated temperatures (to 750C) reflects the dehydration of muscovite + quartz to K-feldspar + sillimanite. After recovering the sample, we are able to support this hypothesis by identifying the presence of water in the assemblage and through the presence of newly formed K-feldspar and sillimanite.

Benson, P.; Zappone, A.

2012-04-01

375

A NPxY-independent {beta}5 integrin activation signal regulates phagocytosis of apoptotic cells  

SciTech Connect

Integrin receptors are heterodimeric transmembrane receptors with critical functions in cell adhesion and migration, cell cycle progression, differentiation, apoptosis, and phagocytosis of apoptotic cells. Integrins are activated by intracellular signaling that alter the binding affinity for extracellular ligands, so-called inside to outside signaling. A common element for integrin activation involves binding of the cytoskeletal protein talin, via its FERM domain, to a highly conserved NPxY motif in the {beta} chain cytoplasmic tails, which is involved in long-range conformation changes to the extracellular domain that impinges on ligand affinity. When the human beta-5 ({beta}5) integrin cDNA was expressed in {alpha}v positive, {beta}5 and {beta}3 negative hamster CS-1 cells, it promoted NPxY-dependent adhesion to VTN-coated surfaces, phosphorylation of FAK, and concomitantly, {beta}5 integrin-EGFP protein was recruited into talin and paxillin-containing focal adhesions. Expression of a NPxY destabilizing {beta}5 mutant (Y750A) abrogated adhesion and {beta}5-Y750A-EGFP was excluded from focal adhesions at the tips of stress fibers. Surprisingly, expression of {beta}5 Y750A integrin had a potent gain-of-function effect on apoptotic cell phagocytosis, and further, a {beta}5-Y750A-EGFP fusion integrin readily bound MFG-E8-coated 10 {mu}m diameter microspheres developed as apoptotic cell mimetics. The critical sequences in {beta}5 integrin were mapped to a YEMAS motif just proximal to the NPxY motif. Our studies suggest that the phagocytic function of {beta}5 integrin is regulated by an unconventional NPxY-talin-independent activation signal and argue for the existence of molecular switches in the {beta}5 cytoplasmic tail for adhesion and phagocytosis.

Singh, Sukhwinder; D'mello, Veera [Department of Biochemistry and Molecular Biology, UMDNJ-New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103-6399 (United States); Henegouwen, Paul van Bergen en [Utrecht University, Department of Molecular Cell Biology, Padualaan 8 3584 CH Utrecht (Netherlands); Birge, Raymond B. [Department of Biochemistry and Molecular Biology, UMDNJ-New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103-6399 (United States); Utrecht University, Department of Molecular Cell Biology, Padualaan 8 3584 CH Utrecht (Netherlands)], E-mail: birgera@umdnj.edu

2007-12-21

376

HES6 reverses nuclear reprogramming of insulin-producing cells following cell fusion  

SciTech Connect

To examine the mechanism by which growth-stimulated pancreatic {beta}-cells dedifferentiate, somatic cell fusions were performed between MIN6, a highly differentiated mouse insulinoma, and {beta}lox5, a cell line derived from human {beta}-cells which progressively dedifferentiated in culture. MIN6/{beta}lox5 somatic cells hybrids underwent silencing of insulin expression and a marked decline in PDX1, NeuroD, and MafA, indicating that {beta}lox5 expresses a dominant transacting factor(s) that represses {beta}-cell differentiation. Expression of Hes1, which inhibits endocrine differentiation was higher in hybrid cells than in parental MIN6 cells. Hes6, a repressor of Hes1, was highly expressed in primary {beta}-cells as well as MIN6, but was repressed in hybrids. Hes6 overexpression using a retroviral vector led to a decrease in Hes1 levels, an increase in {beta}-cell transcription factors and partial restoration of insulin expression. We conclude that the balance of Notch activators and inhibitors may play an important role in maintaining the {beta}-cell differentiated state.

Ball, Andrew J. [UCSD Department of Pediatrics, 9500 Gilman Drive, La Jolla, CA 92093-0816 (United States); Abrahamsson, Annelie E. [UCSD Department of Pediatrics, 9500 Gilman Drive, La Jolla, CA 92093-0816 (United States); Tyrberg, Bjoern [UCSD Department of Pediatrics, 9500 Gilman Drive, La Jolla, CA 92093-0816 (United States); Burnham Institute for Medical Research (United States); Itkin-Ansari, Pamela [UCSD Department of Pediatrics, 9500 Gilman Drive, La Jolla, CA 92093-0816 (United States); Burnham Institute for Medical Research (United States); Levine, Fred [UCSD Department of Pediatrics, 9500 Gilman Drive, La Jolla, CA 92093-0816 (United States); Burnham Institute for Medical Research (United States); E-mail: flevine@ucsd.edu

2007-04-06

377

High Energy Electron Confinement in a Magnetic Cusp Configuration  

E-print Network

We report experimental results validating the concept that plasma confinement is enhanced in a magnetic cusp configuration when beta (plasma pressure/magnetic field pressure) is order of unity. This enhancement is required for a fusion power reactor based on cusp confinement to be feasible. The magnetic cusp configuration possesses a critical advantage: the plasma is stable to large scale perturbations. However, early work indicated that plasma loss rates in a reactor based on a cusp configuration were too large for net power production. Grad and others theorized that at high beta a sharp boundary would form between the plasma and the magnetic field, leading to substantially smaller loss rates. The current experiment validates this theoretical conjecture for the first time and represents critical progress toward the Polywell fusion concept which combines a high beta cusp configuration with an electrostatic fusion for a compact, economical, power-producing nuclear fusion reactor.

Park, Jaeyoung; Sieck, Paul E; Offermann, Dustin T; Skillicorn, Michael; Sanchez, Andrew; Davis, Kevin; Alderson, Eric; Lapenta, Giovanni

2014-01-01

378

Accessible Passively Stored Highly Spin-Polarized Deuterium in Solid Hydrogen Deuterium, with Application to Inertially Confined Fusion  

NASA Astrophysics Data System (ADS)

Highly spin-polarized D in solid HD was produced in a dilution refrigerator-magnet system under conditions whereby the polarization remains high upon removal of the sample to a 1K, modest field (~0.1 T) environment. This retained polarization remains for many hours to days, sufficient to allow the polarized material to be transported to distant locations and utilized there. The first intended application of this system is for inertially confined fusion (ICF) experiments with spin-polarized D fuel. The actual (vector) polarization attained thus far is P^{rm D} = 38%. The maximum D polarization obtainable with our present refrigerator and magnet (8 mK and 13 T) is 61%. The difference is due to our reluctance to wait the full time constants in these demonstration experiments and due to the inability to attain full efficiency in radio-frequency dynamic polarization transfer between D and H, the maximum polarizability of the latter in our system equaling about 85%. In addition to implementation of the polarization method, it was also necessary to develop methods for cold (4 K) sample transfer with engagement and disengagement provisions for the dilution-refrigerator apparatus, a storage -transport cryostat, various sample-preparation and diagnostic apparatuses, and an interface to an experimental destination facility, in the present case, the OMEGA fusion chamber at the University of Rochester's Laboratory for Laser Energetics. The nature of the fusion experiments required designing and constructing a complex mating system with interchange of cold shrouds to ascertain the sample was always shielded from room temperature black body radiation, and still provide means for positioning the target to within a few microns of the intersection of the high power laser beams. Means of filling plastic target shells to high pressure (at room temperature) with our special isotopic composition of HD with H_2 and D_2 impurities, and condensing them at cryogenic temperatures, were also perfected.

Alexander, Neil Brooks

1992-01-01

379

Status of fusion maintenance  

SciTech Connect

Effective maintenance will be an essential ingredient in determining fusion system productivity. This level of productivity will result only after close attention is paid to the entire system as an entity and appropriate integration of the elements is made. The status of fusion maintenance is reviewed in the context of the entire system. While there are many challenging developmental tasks ahead in fusion maintenance, the required technologies are available in several high-technology industries, including nuclear fission.

Fuller, G.M.

1984-01-01

380

Intense fusion neutron sources  

Microsoft Academic Search

The review describes physical principles underlying efficient production of free neutrons, up-to-date possibilities and prospects of creating fission and fusion neutron sources with intensities of 1015-1021 neutrons\\/s, and schemes of production and application of neutrons in fusion-fission hybrid systems. The physical processes and parameters of high-temperature plasmas are considered at which optimal conditions for producing the largest number of fusion

B. V. Kuteev; P. R. Goncharov; V. Yu. Sergeev; V. I. Khripunov

2010-01-01

381

Intense fusion neutron sources  

Microsoft Academic Search

The review describes physical principles underlying efficient production of free neutrons, up-to-date possibilities and prospects\\u000a of creating fission and fusion neutron sources with intensities of 10151021 neutrons\\/s, and schemes of production and application of neutrons in fusion-fission hybrid systems. The physical processes\\u000a and parameters of high-temperature plasmas are considered at which optimal conditions for producing the largest number of\\u000a fusion

B. V. Kuteev; P. R. Goncharov; V. Yu. Sergeev; V. I. Khripunov

2010-01-01

382

Achievement of High Fusion Performance in JT-60U Reversed Shear Discharges  

SciTech Connect

Fusion performance of reversed shear discharges with an {ital L}-mode edge has been significantly improved in a thermonuclear dominant regime with up to 2.8 MA of plasma current in the JT-60U tokamak. The core plasma energy is efficiently confined due to the existence of persistent internal transport barriers formed for both ions and electrons at a large minor radius of r/a{approximately}0.7 near the boundary of the reversed shear region. In an assumed deuterium-tritium fuel, the peak fusion amplification factor defined for transient conditions involving the dW/dt term would be in excess of unity. {copyright} {ital 1997} {ital The American Physical Society}

Ishida, S.; Fujita, T.; Akasaka, H.; Akino, N.; Annou, K.; Aoyagi, T.; Arai, T.; Arakawa, K.; Asakura, N.; Azumi, M.; Budny, R.; Chiba, S.; Da Costa, O.; Ebisawa, N.; Fujii, T.; Fukuda, T.; Funahashi, A.; Grisham, L.; Gunji, S.; Hamamatsu, K.; Hasegawa, Y.; Hatae, T.; Higashijima, S.; Hiratsuka, H.; Hirauchi, S.; Hirayama, T.; Honda, A.; Honda, M.; Hosogane, N.; Ichige, H.; Ide, S.; Ikeda, Y.; Isaka, M.; Isayama, A.; Isei, N.; Ishii, Y.; Isozaki, N.; Itami, K.; Itoh, T.; Iwahashi, T.; Kamada, Y.; Kaminaga, A.; Kashiwabara, T.; Kawai, M.; Kawamata, Y.; Kawano, Y.; Kazama, D.; Kazawa, M.; Kikuchi, M.; Kimura, H.; Kimura, T.; Kishimoto, H.; Kishimoto, Y.; Kitamura, S.; Kiyono, K.; Kodama, K.; Koide, Y.; Kokusen, S.; Kondoh, T.; Konoshima, S.; Koog, J.; Kramer, G.J.; Kubo, H.; Kurihara, K.; Kurita, G.; Kuriyama, M.; Kusama, Y.; Masaki, K.; Matsuda, T.; Matsumoto, T.; Matukawa, M.; Miura, T.; Miya, N.; Miyachi, K.; Miyata, H.; Miyo, Y.; Mogaki, K.; Mori, M.; Morimoto, M.; Morioka, S.; Moriyama, S.; Nagami, M.; Nagashima, A.; Nagashima, K.; Nagaya, S.; Naito, O.; Nakamura, Y.; Nemoto, M.; Neyatani, Y.; Nishitani, T.; Ogiwara, N.; Ohga, T.; Ohsawa, M.; Ohshima, T.; Oikawa, T.; Okabe, T.; Okano, J.; Omori, K.; Omori, S.; Omori, Y.; Onose, Y.; Oohara, H.; Ozeki, T.; Saidoh, M.; Saigusa, M.; Saito, N.; Sakasai, A.; Sakata, S.; Sakurai, S.; Sasajima, T.; Sato, M.; Scott, S.D.; Seimiya, M.; Seiki, H.; Seki, M.; Shimada, M.; Shimizu, K.; Shimizu, M.; Shimono, M.; Shinozaki, S.; Shirai, H.; Shitomi, M.; Suganuma, K.; Sugie, T.; Sunaoshi, H.; Takahashi, M.; Takahashi, S.; Takeji, S.; Takenaga, H.; Takizuka, T.; Tamai, H.; Terakado, M.; Terakado, T.; Tobita, K.; Tokuda, S.; Totsuka, T.; Toyokawa, Y.; Toyoshima, N.; Tsuchiya, K.; Tsugita, T.; Tsukahara, Y.; Tuda, T.; Uramoto, Y.; Ushigusa, K.; Usui, K.; Yagyu, J.; Yamagiwa, M.; Yamamoto, M.; Yamamoto, T.; Yamashita, O.; Yokokura, K.; Yoshida, H.; Yoshida, M.; Yoshino, R. [Japan Atomic Energy Research Institute, Naka Fus (Japan)] [Japan Atomic Energy Research Institute, Naka Fus (Japan)

1997-11-01

383

Driving high-gain shock-ignited inertial confinement fusion targets by green laser light  

SciTech Connect

Standard direct-drive inertial confinement fusion requires UV light irradiation in order to achieve ignition at total laser energy of the order of 1 MJ. The shock-ignition approach opens up the possibility of igniting fusion targets using green light by reducing the implosion velocity and laser-driven ablation pressure. An analytical model is derived, allowing to rescale UV-driven targets to green light. Gain in the range 100-200 is obtained for total laser energy in the range 1.5-3 MJ. With respect to the original UV design, the rescaled targets are less sensitive to irradiation asymmetries and hydrodynamic instabilities, while operating in the same laser-plasma interaction regime.

Atzeni, Stefano; Marocchino, Alberto; Schiavi, Angelo [Dipartimento SBAI, Universita di Roma 'La Sapienza' and CNISM, Via A. Scarpa 14-16, I-00161 Roma (Italy)

2012-09-15

384

Production of high purity TeO 2 single crystals for the study of neutrinoless double beta decay  

NASA Astrophysics Data System (ADS)

High purity TeO 2 crystals are produced to be used for the search for the neutrinoless double beta decay of 130Te. Dedicated production lines for raw material synthesis, crystal growth, and surface processing were built compliant with radio-purity constraints specific to rare event physics experiments. High sensitivity measurements of radio-isotope concentrations in raw materials, reactants, consumables, ancillaries, and intermediary products used for TeO 2 crystals production are reported. Indications are given on the crystals perfection and how it is achieved and maintained in a large scale production process. Production and certification protocols are presented and resulting ready-to-use TeO 2 crystals are described.

Arnaboldi, C.; Brofferio, C.; Bryant, A.; Bucci, C.; Canonica, L.; Capelli, S.; Carrettoni, M.; Clemenza, M.; Dafinei, I.; Di Domizio, S.; Ferroni, F.; Fiorini, E.; Ge, Z.; Giachero, A.; Gironi, L.; Giuliani, A.; Gorla, P.; Guardincerri, E.; Kadel, R.; Kazkaz, K.; Kogler, L.; Kolomensky, Y.; Larsen, J.; Laubenstein, M.; Li, Y.; Maiano, C.; Martinez, M.; Maruyama, R.; Nisi, S.; Nones, C.; Norman, Eric B.; Nucciotti, A.; Orio, F.; Pattavina, L.; Pavan, M.; Pessina, G.; Pirro, S.; Previtali, E.; Rusconi, C.; Scielzo, Nicholas D.; Sisti, M.; Smith, Alan R.; Tian, W.; Vignati, M.; Wang, H.; Zhu, Y.

2010-10-01

385

Transmutation of high-level fission products and actinides in a laser-driven fusion reactor  

Microsoft Academic Search

Incineration of [sup 90]Sr and [sup 137]Cs b thermal or fast neutrons is a very difficult problem. A 14-MeV neutron source based on intertial confinement fusion is a more appropriate choice. For the first time, the contribution of the (n,2n) reaction to incineration is revealed. The energy and nuclei balance for a system of several nuclear power plants and a

N. Basov; V. B. Rozanov; N. I. Belousov; P. A. Grishunin; V. V. Kharitonov; V. I. Subbotin

1992-01-01

386

Efficiency of a Traveling Wave Direct Energy Converter with High-Density Beam for Applications to Aneutronic Fusion Experiments  

NASA Astrophysics Data System (ADS)

Due to the appeal of aneutronic fusion, a variety of reactor concepts have been proposed in past. In most cases, to achieve a positive net power balance these reactor concepts rely on a significant re-circulation of the energy produced to maintain a non-equilibrium configuration (unlike ignited plasmas). The availability of a direct conversion process with high efficiency is then critical for determining the feasibility of a reactor (particularly when the ``almost true aneutronic'' reaction like p-^11B is considered). A Traveling Wave Direct Energy Converter (TWDEC, [1]) is considered for the energy conversion of a high-density beam formed by the fusion products (MeV-range ?-particles). As in [2], a PIC code is utilized for a realistic beam model. The study is focused on the possibility of obtaining high-efficiency coupling between a modulated high-density ``bunched'' beam, accounting also for a neutralizing electron environment, and the TWDEC electrode collector structure.[4pt] [1] Momota et al. (1999) Fus. Tech., 35, 60[0pt] [2] Y.Yasaka et al. (2009), Nucl. Fus., 49, 075009

Tarditi, Alfonso

2012-03-01

387

SIPHORE: Conceptual Study of a High Efficiency Neutral Beam Injector Based on Photo-detachment for Future Fusion Reactors  

SciTech Connect

An innovative high efficiency neutral beam injector concept for future fusion reactors is under investigation (simulation and R and D) between several laboratories in France, the goal being to perform a feasibility study for the neutralization of intense high energy (1 MeV) negative ion (NI) beams by photo-detachment.The objective of the proposed project is to put together the expertise of three leading groups in negative ion quantum physics, high power stabilized lasers and neutral beam injectors to perform studies of a new injector concept called SIPHORE (SIngle gap PHOto-neutralizer energy REcovery injector), based on the photo-detachment of negative ions and energy recovery of unneutralised ions; the main feature of SIPHORE being the relevance for the future Fusion reactors (DEMO), where high injector efficiency (up to 70-80%), technological simplicity and cost reduction are key issues to be addressed.The paper presents the on-going developments and simulations around this project, such as, a new concept of ion source which would fit with this injector topology and which could solve the remaining uniformity issue of the large size ion source, and, finally, the presentation of the R and D program in the laboratories (LAC, ARTEMIS) around the photo-neutralization for Siphore.

Simonin, A.; Christin, L.; Esch, H. de; Garibaldi, P.; Grand, C.; Villecroze, F. [IRFM, CEA Cadarache, IRFM, St. Paul-lez-Durance (France); Blondel, C.; Delsart, C.; Drag, C.; Vandevraye, M. [LAC :Aime-Cotton Laboratory, Univ. Paris-sud, Orsay (France); Brillet, A.; Chaibi, W. [ARTEMIS Laboratory, Cote-d'azur Observatory, Nice (France)

2011-09-26

388

Facility for high-heat flux testing of irradiated fusion materials and components using infrared plasma arc lamps  

NASA Astrophysics Data System (ADS)

A new high-heat flux testing (HHFT) facility using water-wall stabilized high-power high-pressure argon plasma arc lamps (PALs) has been developed for fusion applications. It can accommodate irradiated plasma facing component materials and sub-size mock-up divertor components. Two PALs currently available at Oak Ridge National Laboratory can provide maximum incident heat fluxes of 4.2 and 27 MW m-2, which are prototypic of fusion steady state heat flux conditions, over a heated area of 9 12 and 1 10 cm2, respectively. The use of PAL permits the heat source to be environmentally separated from the components of the test chamber, simplifying the design to accommodate safe testing of low-level irradiated articles and materials under high-heat flux. Issues related to the operation and temperature measurements during testing of tungsten samples are presented and discussed. The relative advantages and disadvantages of this photon-based HHFT facility are compared to existing e-beam and particle beam facilities used for similar purposes.

Sabau, Adrian S.; Ohriner, Evan K.; Kiggans, Jim; Harper, David C.; Snead, Lance L.; Schaich, Charles R.

2014-04-01

389

(Fusion energy research)  

SciTech Connect

This report discusses the following topics: principal parameters achieved in experimental devices (FY88); tokamak fusion test reactor; Princeton beta Experiment-Modification; S-1 Spheromak; current drive experiment; x-ray laser studies; spacecraft glow experiment; plasma deposition and etching of thin films; theoretical plasma; tokamak modeling; compact ignition tokamak; international thermonuclear experimental reactor; Engineering Department; Project Planning and Safety Office; quality assurance and reliability; and technology transfer.

Phillips, C.A. (ed.)

1988-01-01

390

Engineered aggregation inhibitor fusion for production of highly amyloidogenic human islet amyloid polypeptide.  

PubMed

Human islet amyloid polypeptide (IAPP) is the major component of pancreatic amyloid deposits in type 2 diabetes. The structural conversion of IAPP from a monomeric state into amyloid assemblies is the subject of intense research. Recombinant production of IAPP is, however, difficult due to its extreme aggregation propensity. Here we describe a novel strategy for expression of IAPP in Escherichia coli, based on an engineered protein tag, which sequesters IAPP monomers and prevents IAPP aggregation. The IAPP-binding protein HI18 was selected by phage display from a ?-wrapin library. Fusion of HI18 to IAPP enabled the soluble expression of the construct. IAPP was cleaved from the fusion construct and purified to homogeneity with a yield of 3mg of isotopically labeled peptide per liter of culture. In the monomeric state, IAPP was largely disordered as evidenced by far-UV CD and liquid-state NMR spectroscopy but competent to form amyloid fibrils according to atomic force microscopy. These results demonstrate the ability of the engineered ?-wrapin HI18 for shielding the hydrophobic sequence of IAPP during expression and purification. Fusion of aggregation-inhibiting ?-wrapins is a suitable approach for the recombinant production of aggregation-prone proteins. PMID:24928165

Mirecka, Ewa Agnieszka; Gremer, Lothar; Schiefer, Stephanie; Oesterhelt, Filipp; Stoldt, Matthias; Willbold, Dieter; Hoyer, Wolfgang

2014-12-10

391

Dense Plasma Focus - From Alternative Fusion Source to Versatile High Energy Density Plasma Source for Plasma Nanotechnology  

NASA Astrophysics Data System (ADS)

The dense plasma focus (DPF), a coaxial plasma gun, utilizes pulsed high current electrical discharge to heat and compress the plasma to very high density and temperature with energy densities in the range of 1-10 1010 J/m3. The DPF device has always been in the company of several alternative magnetic fusion devices as it produces intense fusion neutrons. Several experiments conducted on many different DPF devices ranging over several order of storage energy have demonstrated that at higher storage energy the neutron production does not follow I4 scaling laws and deteriorate significantly raising concern about the device's capability and relevance for fusion energy. On the other hand, the high energy density pinch plasma in DPF device makes it a multiple radiation source of ions, electron, soft and hard x-rays, and neutrons, making it useful for several applications in many different fields such as lithography, radiography, imaging, activation analysis, radioisotopes production etc. Being a source of hot dense plasma, strong shockwave, intense energetic beams and radiation, etc, the DPF device, additionally, shows tremendous potential for applications in plasma nanoscience and plasma nanotechnology. In the present paper, the key features of plasma focus device are critically discussed to understand the novelties and opportunities that this device offers in processing and synthesis of nanophase materials using, both, the top-down and bottom-up approach. The results of recent key experimental investigations performed on (i) the processing and modification of bulk target substrates for phase change, surface reconstruction and nanostructurization, (ii) the nanostructurization of PLD grown magnetic thin films, and (iii) direct synthesis of nanostructured (nanowire, nanosheets and nanoflowers) materials using anode target material ablation, ablated plasma and background reactive gas based synthesis and purely gas phase synthesis of various different types of nanostructured materials using DPF device will discussed to establish this device as versatile tool for plasma nanotechnology.

Rawat, R. S.

2015-03-01

392

High-Level Expression in Escherichia coli of Enzymatically Active Fusion Proteins Containing the Domains of Mammalian Cytochromes P450 and NADPH P450 Reductase Flavoprotein  

Microsoft Academic Search

This report describes the properties of two mammalian cytochromes P450 that have been expressed at high levels in Escherichia coli as enzymatically active fusion proteins containing the flavoprotein domain of rat NADPH-cytochrome P450 reductase (EC 1.6.2.4). Fusion proteins were prepared by engineering the cDNAs for the steroid-metabolizing bovine adrenal P450 17A with the cDNA for rat liver NADPH-P450 reductase with

Charles W. Fisher; Manjunath S. Shet; Deborah L. Caudle; Cheryl A. Martin-Wixtrom; Ronald W. Estabrook

1992-01-01

393

Beta-cell-cytotoxic CD8+ T cells from nonobese diabetic mice use highly homologous T cell receptor alpha-chain CDR3 sequences.  

PubMed

Insulin-dependent diabetes mellitus (IDDM) in nonobese diabetic (NOD) mice results from a cell-mediated autoimmune process against pancreatic beta-cells. We have shown that beta-cell-cytotoxic CD8+ T cell clones can transfer IDDM to irradiated NOD mice if co-injected with nondiabetogenic CD4+ spleen T cells. To determine whether CTLs recruited to pancreatic islets recognize a restricted set of local Ags, we sequenced TCR-alpha and TCR-beta cDNA generated by anchor PCR from CD8+ CTL lines and clones derived from islets of 10 different NOD mice. These CTL lines were oligoclonal, but did not show skewed V alpha, V beta, J alpha, or J beta gene usage when compared with CD8+ spleen T cells. However, of the 26 different CTL-derived TCR-alpha sequences from all of these CTL lines and clones, 17 (65%) used one of three highly related, N region-encoded, CDR3 motifs. Motifs 1 and 2 (7 clonotypes each) contained a hydrophobic amino acid followed by Arg and a negatively charged or a polar residue (Asn or Gly), respectively. Motif 3 (3 clonotypes) was x-Arg-Gly. In 12 of these 17 rearrangements, the core sequence was followed by Tyr or Ser. By contrast, none of 31 different TCR-alpha rearrangements used by CD8+ spleen T cells encoded motifs 1 or 2, and only one encoded motif 3. Different TCR-beta rearrangements within individual lines also used homologous CDR3 sequences, but these sequences varied between lines. Skewed TCR-alpha-CDR3 usage by islet-derived CTLs was substantiated further by isolation of CTL clones transcribing highly homologous TCR-alpha, but different TCR-beta, rearrangements. These data suggest that CTLs recruited to pancreatic islets during spontaneous IDDM recognize a restricted set of beta-cell autoantigenic determinants. PMID:7868915

Santamaria, P; Utsugi, T; Park, B J; Averill, N; Kawazu, S; Yoon, J W

1995-03-01

394

Nuclear fusion  

Microsoft Academic Search

The advantages of nuclear fusion as an energy source and research progress in this area are summarized. The current state of the art is described. Laser fusion, inertial confinement fusion, and magnetic fusion (the tokamak) are explained, the latter in some detail. Remaining problems and planned future reactors are considered. They are the Compact Ignition Tokamak (CIT), the International Thermonuclear

T. K. Fowler

1989-01-01

395

The pattern recognition of 136Xe double beta decay events and background discrimination in a high pressure xenon TPC  

NASA Astrophysics Data System (ADS)

High pressure xenon gas time projection chambers (TPC) for the detection of the neutrinoless double beta decay of 136Xe provide good energy resolution and detailed topological information of events. The ionization topology of the double beta decay event of 136Xe in gaseous xenon has a characteristic shape defined by the two straggling electron tracks ending in two larger energy depositions. With a properly pixelized readout, this topological information is invaluable for performing powerful background discrimination. In this study, we carry out detailed simulations of the signal topology, as well as of the competing topologies from gamma events that typically compose the background at these energies. We define observables based on graph theory concepts and develop automated discrimination algorithms which reduce the background level in the region of interest by around three orders of magnitude, while keeping signal efficiency of 40%. This result supports the competitiveness of current or future ?? experiments based on gas TPCs, such as the Neutrino Xenon TPC (NEXT) currently under construction at the Laboratorio Subterrneo de Canfranc.

Cebrin, S.; Dafni, T.; Gmez, H.; Herrera, D. C.; Iguaz, F. J.; Irastorza, I. G.; Luzn, G.; Segui, L.; Toms, A.

2013-12-01

396

High-Throughput Viral Expression of cDNAGreen Fluorescent Protein Fusions Reveals Novel Subcellular Addresses and Identifies Unique Proteins That Interact with Plasmodesmata  

PubMed Central

A strategy was developed for the high-throughput localization of unknown expressed proteins in Nicotiana benthamiana. Libraries of random, partial cDNAs fused to the 5? or 3? end of the gene for green fluorescent protein (GFP) were expressed in planta using a vector based on Tobacco mosaic virus. Viral populations were screened en masse on inoculated leaves using a confocal microscope fitted with water-dipping lenses. Each viral infection site expressed a unique cDNA-GFP fusion, allowing several hundred cDNA-GFP fusions to be screened in a single day. More than half of the members of the library carrying cDNA fusions to the 5? end of gfp that expressed fluorescent fusion proteins displayed discrete, noncytosolic, subcellular localizations. Nucleotide sequence determination of recovered cDNA sequences and subsequent sequence searches showed that fusions of GFP to proteins that had a predicted subcellular address became localized with high fidelity. In a subsequent screen of >20,000 infection foci, 12 fusion proteins were identified that localized to plasmodesmata, a subcellular structure for which very few protein components have been identified. This virus-based system represents a method for high-throughput functional genomic study of plant cell organelles and allows the identification of unique proteins that associate with specific subcompartments within organelles. PMID:12837943

Escobar, Nieves Medina; Haupt, Sophie; Thow, Graham; Boevink, Petra; Chapman, Sean; Oparka, Karl

2003-01-01

397

Fusion Energy Education  

NSDL National Science Digital Library

The basics of fusion are deceptively simple: the process powers the sun and other stars, and it all takes place when atomic nuclei collide at high speed. But many questions remain. How can humans develop and exploit fusion energy? Is there a way to convert it more efficiently into useful mechanical, electrical, or thermal energy? This intriguing site, created by the Lawrence Livermore National Laboratory and the Princeton Plasma Physics Laboratory, presents an online fusion course designed to teach students and others about how fusion works and how it might be harnessed in the future. Visitors can try out The Guided Tour to get started, or they can click on one of the Main Topics. These include Energy Sources and Conversions, Two Key Fusion Reactions, and Creating the Conditions for Fusion. Each section contains graphics, explanatory text, and various diagrams. The site also includes charts which can be printed out for classroom use.

398

Reduced expression of transforming growth factor-beta receptor type III in high stage neuroblastomas  

PubMed Central

Transforming growth factor beta (TGF-?) is a powerful inhibitor of cell proliferation and a potent inducer of differentiation. Resistance to TGF-? action is a characteristic of many malignancies and has been attributed to alterations of TGF-? receptors as well as disturbance of downstream transduction pathways. To analyse the TGF-? response in neuroblastoma, the expression of TGF-?1 and TGF-? type I, II and III receptor genes was investigated in 61 cancer samples by means of reverse transcription polymerase chain reaction. The specimens analysed belong to different stages, namely nine samples of stage 1, ten of stage 2, nine of stage 3 and 28 of stage 4. Moreover, five samples were of stage 4S, which represents a tumour form undergoing spontaneous regression. The results obtained show that TGF-?1 and TGF-? type I and II receptor genes appear to be almost equally expressed in neuroblastomas of all stages. Conversely, TGF-? type III receptor gene expression, which is required for an efficacious TGF-? binding and function, is strongly reduced exclusively in neuroblastomas of stages 3 and 4. These findings were directly confirmed by immunohistochemical analyses of ten neuroblastoma specimens. Our results suggest the occurrence of an altered TGF-? response in advanced neuroblastomas which might be an important mechanism for escaping growth control and for developing invasiveness. Moreover, our findings allow the proposal of a novel mechanism, namely down-regulation of TGF-? type III receptor gene expression, to avoid TGF-? inhibitory activity. 2000 Cancer Research Campaign PMID:10735501

Iolascon, A; Giordani, L; Borriello, A; Carbone, R; Izzo, A; Tonini, G P; Gambini, C; Ragione, F Della

2000-01-01

399

High burden of invasive beta-haemolytic streptococcal infections in Fiji.  

PubMed

We undertook a 5-year retrospective study of group A streptococcal (GAS) bacteraemia in Fiji, supplemented by a 9-month detailed retrospective study of beta-haemolytic streptococcal (BHS) infections. The all-age incidence of GAS bacteraemia over 5 years was 11.6/100,000. Indigenous Fijians were 4.7 times more likely to present with invasive BHS disease than people of other ethnicities, and 6.4 times more likely than Indo-Fijians. The case-fatality rate for invasive BHS infections was 28%. emm-typing was performed on 23 isolates: 17 different emm-types were found, and the emm-type profile was different from that found in industrialized nations. These data support the contentions that elevated rates of invasive BHS and GAS infections are widespread in developing countries, and that the profile of invasive organisms in these settings reflects a wide diversity of emm-types and a paucity of types typically found in industrialized countries. PMID:17631691

Steer, A C; Jenney, A J W; Oppedisano, F; Batzloff, M R; Hartas, J; Passmore, J; Russell, F M; Kado, J H H; Carapetis, J R

2008-05-01

400

Pleomorphic Carcinoma of the Lung with High Serum Beta-human Chorionic Gonadotropin Level and Gynecomastia  

PubMed Central

Although gynecomastia is a well-defined paraneoplastic syndrome in patients with non-small cell lung cancer, the association with pleomorphic carcinoma has not been reported. A 50-yr-old man presented with bilateral gynecomastia and elevated serum beta-human chorionic gonadotropin (?hCG) level. Chest tomography showed a mass in the right middle lobe. Right middle lobectomy and mediastinal lymph node dissection were performed. ?hCG levels decreased rapidly after surgery. Histological examination revealed pleomorphic carcinoma with positive immunostaining for ?hCG. Serum ?hCG levels began to increase gradually on postoperatively 4th month. Computed tomography detected recurrence and chemotherapy was started. After second cycle of chemotherapy, ?hCG levels decreased dramatically again and tomography showed regression in mass. Patient died 6 months later due to brain metastasis. ?hCG expression may be associated with aggressive clinical course and increased risk of recurrence, also ?hCG levels may be used to evaluate therapy response in patients with pleomorphic carcinoma. PMID:21165299

Hasbal, Baris; Aydin, Kubra; Bozkurt, Mustafa; Namal, Esat; Oz, Buge; Kaynak, Kamil; Demir, Gokhan

2010-01-01

401

High temperature conductivity of potassium-beta(double prime)-alumina  

NASA Technical Reports Server (NTRS)

Potassium beta(double prime)-alumina (BDPA) single crystals have been reported by several groups to leave higher ionic conductivity than sodium BDPA crystals at room temperature, and similar conductivities are obtained at temperatures up to 600-700 K. Potassium BDPA ceramics have been reported to have significantly poorer conductivities than those of sodium BDPA ceramics, but conductivity measurements at temperatures above 625 K have not been reported. In this study, K(+)-BDPA ceramics were prepared from Na(+)-BDPA ceramic using a modified version of the exchange reaction with KCl vapor reported by Crosbie and Tennenhouse (1982), and the conductivity has been measured in K vapor at temperatures up to 1223 K, using the method of Cole et al. (1979). The results indicate reasonable agreement with earlier data on K(+)-BDPA ceramic measured in a liquid K cell, but show that the K(+)-BDPA ceramic's conductivity approaches that of Na(+)-BDPA ceramic at higher temperatures, being within a factor of four at 700 K and 60 percent of the conductivity of Na(+)-BDPA at T over 1000 K. Both four-probe dc conductivity and four probe ac impedance measurements were used to characterize the conductivity. A rather abrupt change in the grain boundary resistance suggesting a possible phase change in the intergranular material, potassium aluminate, is seen in the ac impedance behavior.

Williams, R. M.; Jeffries-Nakamura, B.; Underwood, M. L.; Ryan, M. A.; O'Connor, D.; Kikkert, S.

1992-01-01

402

Reconstitution of high affinity. cap alpha. /sub 2/ adrenergic agonist binding by fusion with a pertussis toxin substrate  

SciTech Connect

High affinity ..cap alpha../sub 2/ adrenergic agonist binding is thought to occur via a coupling of the ..cap alpha../sub 2/ receptor with N/sub i/, the inhibitory guanyl nucleotide binding protein. Human platelet membranes pretreated at pH 11.5 exhibit a selective inactivation of agonist binding and N/sub i/. To further study the mechanism of agonist binding, alkali treated membranes (ATM) were mixed with membranes pretreated with 10 ..mu..M phenoxybenzamine to block ..cap alpha../sub 2/ receptors (POB-M). The combined membrane pellet was incubated in 50% polyethylene glycol (PEG) to promote membrane-membrane fusion and assayed for binding to the ..cap alpha../sub 2/ agonist (/sup 3/H)UK 14,304 (UK) and the antagonist (/sup 3/H) yohimbine. PEG treatment resulted in a 2-4 fold enhancement of UK binding whereas yohimbine binding was unchanged. No enhancement of UK binding was observed in the absence of PEG treatment. The reconstitution was dependent on the addition of POB-M. They found that a 1:1 ratio of POB-M:ATM was optimal. Reconstituted binding was inhibited by GppNHp. Fusion of rat C6 glioma cell membranes, which do not contain ..cap alpha../sub 2/ receptors, also enhanced agonist binding to ATM. Fusion of C6 membranes from cells treated with pertussis toxin did not enhance (/sup 3/H) UK binding. These data show that a pertussis toxin sensitive membrane component, possibly N/sub i/, can reconstitute high affinity ..cap alpha../sub 2/ agonist binding.

Kim, M.H.; Neubig, R.R.

1986-03-05

403

A sensitive procedure for the study of beta-carotene-d8 metabolism in humans using high performance liquid chromatography-mass spectrometry.  

PubMed

This report describes the development of a robust method of high sensitivity for studying the metabolism of beta-carotene-d8 in humans using a combination of liquid chromatography/particle beam-mass spectrometry (LC/PB-MS). The utility of the LC/PB-MS method was demonstrated in a pilot study. The carotenoids were extracted from plasma into hexane and separated by reverse phase high performance liquid chromatography (HPLC) using a C-18 column. The HPLC effluent was nebulized using helium and the solvent was removed under vacuum within the dual-stage particle beam interface. The de-solvated carotenoids were ionized in the negative-ion mode (electron capture) using methane chemical ionization and detected using selected ion monitoring. The limit of detection of the method was on the order of 0.3 ng (approximately 0.6 pmol) for beta-carotene. beta-Carotene-d8 was quantified in the plasma over a concentration range of two orders of magnitude using beta-carotene-(13)C(40) as an internal standard. The overall coefficient of variance (CV) for determining the concentration of the analytes from 30 microliter of plasma was 3.9% for beta-carotene and 2.4% for beta-carotene-d8. Using the LC/PB-MS method, the concentration of beta-carotene-d8 was determined in the plasma of a subject who had consumed a single 5-mg dose over a 30-day period. The sensitive semi-automated procedure is capable of high sample throughput and makes large comprehensive studies feasible. PMID:10828096

Pawlosky, R J; Flanagan, V P; Novotny, J A

2000-06-01

404

Influenza Virus-Membrane Fusion Triggered by Proton Uncaging for Single Particle Studies of Fusion Kinetics  

E-print Network

Influenza Virus-Membrane Fusion Triggered by Proton Uncaging for Single Particle Studies of Fusion for studying membrane fusion, focusing on influenza virus fusion to lipid bilayers, which provides high temporal resolution through the rapid and coordinated initiation of individual virus fusion events. Each

Daniel, Susan

405

Study of Chelyabinsk LL5 meteorite fragment with a light lithology and its fusion crust using Mssbauer spectroscopy with a high velocity resolution  

SciTech Connect

Study of Chelyabinsk LL5 ordinary chondrite fragment with a light lithology and its fusion crust, fallen on February 15, 2013, in Russian Federation, was carried out using Mssbauer spectroscopy with a high velocity resolution. The Mssbauer spectra of the internal matter and fusion crust were fitted and all components were related to iron-bearing phases such as olivine, pyroxene, troilite, Fe-Ni-Co alloy, and chromite in the internal matter and olivine, pyroxene, troilite, Fe-Ni-Co alloy, and magnesioferrite in the fusion crust. A comparison of the content of different phases in the internal matter and in the fusion crust of this fragment showed that ferric compounds resulted from olivine, pyroxene, and troilite combustion in the atmosphere.

Maksimova, Alevtina A.; Petrova, Evgeniya V.; Grokhovsky, Victor I. [Department of Physical Techniques and Devices for Quality Control, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002 (Russian Federation); Oshtrakh, Michael I., E-mail: oshtrakh@gmail.com; Semionkin, Vladimir A. [Department of Physical Techniques and Devices for Quality Control, Institute of Physics and Technology, Ural Federal University, Ekaterinburg, 620002, Russian Federation and Department of Experimental Physics, Institute of Physics and Technology, Ura (Russian Federation)

2014-10-27

406

Controlled Nuclear Fusion.  

ERIC Educational Resources Information Center

This publication is one of a series of information booklets for the general public published by The United States Atomic Energy Commission. Among the topics discussed are: Importance of Fusion Energy; Conditions for Nuclear Fusion; Thermonuclear Reactions in Plasmas; Plasma Confinement by Magnetic Fields; Experiments With Plasmas; High-Temperature

Glasstone, Samuel

407

FEL amplifiers for fusion  

Microsoft Academic Search

Potential advantages of the free electron laser (FEL) as a fusion driver are noted and proposed high power FEL systems are described. Advantages for fusion of a pulsed multipass FEL system, in which the optical pulses are built up inside a long (approx. 400 m) resonator cavity and a storage ring provides the electron beam, are described. In one possible

S. B. Segall; H. R. Hiddleston; G. C. Catella

1980-01-01

408

Effects of a high-salt diet on adipocyte glucocorticoid receptor and 11-beta hydroxysteroid dehydrogenase 1 in salt-sensitive hypertensive rats.  

PubMed

High-salt diets decrease insulin sensitivity in salt-sensitive hypertensive rats, and glucocorticoids promote adipocyte growth and may have pathophysiological roles in the metabolic syndrome. The aim of this study was to clarify the relationship between high-salt diet and the adipocyte glucocorticoid hormones in salt-sensitive hypertensive rats. Six-week-old Dahl salt-sensitive (DS) hypertensive rats and salt-resistant (DR) rats were fed a high-salt diet or a normal-salt diet for 4 weeks. Fasting blood glucose (FBG), serum adiponectin, plasma insulin, and corticosterone in plasma and in visceral adipose tissues, 11beta-hydroxysteroid dehydrogenase 1 (11beta-HSD1) activities in adipose tissues and glucose uptake in isolated muscle were measured. Animals underwent an oral glucose tolerance test (OGTT). The expression of mRNA for glucocorticoid receptor (GR), 11beta-HSD1 and tumor necrosis factor-alpha (TNF-alpha) in adipose tissues were measured using a real-time PCR. A high-salt diet did not influence FBG; however, decreased 2-deoxy glucose uptake and plasma insulin during OGTT in DS rats. The high-salt diet increased significantly adipose tissue corticosterone concentration and 11beta-HSD1 activities, gene expression for GR, 11beta-HSD1 and TNF-alpha in adipose tissues in DS rats compared with DR rats (p<0.05). The high-salt diet did not influence plasma corticosterone and serum adiponectin concentration in DS and DR rats. These results suggest that changes in GR and 11beta-HSD1 in adipose tissue may contribute to insulin sensitivity in salt-sensitive hypertensive rats. PMID:19646461

Usukura, Mikiya; Zhu, Aoshuang; Yoneda, Takashi; Karashima, Shigehiro; Yagi, Kunimasa; Yamagishi, Masakazu; Takeda, Yoshiyu

2009-11-01

409

Vacuum insulation of the high energy negative ion source for fusion applicationa)  

NASA Astrophysics Data System (ADS)

Vacuum insulation on a large size negative ion accelerator with multiple extraction apertures and acceleration grids for fusion application was experimentally examined and designed. In the experiment, vacuum insulation characteristics were investigated in the JT-60 negative ion source with >1000 apertures on the grid with the surface area of 2 m2. The sustainable voltages varied with a square root of the gap lengths between the grids, and decreased with number of the apertures and with the surface area of the grids. Based on the obtained results, the JT-60SA (super advanced) negative ion source is designed to produce 22 A, 500 keV D- ion beams for 100 s.

Kojima, A.; Hanada, M.; Hilmi, A.; Inoue, T.; Watanabe, K.; Taniguchi, M.; Kashiwagi, M.; Umeda, N.; Tobari, H.; Kobayashi, S.; Yamano, Y.; Grisham, L. R.

2012-02-01

410

Radiochromic film dosimetry of a high dose rate beta source for intravascular brachytherapy.  

PubMed

Good clinical physics practice requires that dose rates of brachytherapy sources be checked by the institution using them,