Note: This page contains sample records for the topic high beta fusion from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: August 15, 2014.
1

Achieving high fusion reactivity in high poloidal beta discharges in TFTR  

SciTech Connect

High poloidal beta discharges have been produced in TFTR that achieved high fusion reactivities at low plasma currents. By rapidly decreasing the plasma current just prior to high-power neutral beam injection, relatively peaked current profiles were created having high l[sub i] > 2, high Troyon-normalized beta, [beta]N > 3, and high poloidal beta. [beta][sub p] [ge] 0.7 R/a. The global energy confinement time after the current ramp was comparable to supershots, and the combination of improved MHD stability and good confinement produced a new high [epsilon][beta][sub p] high Q[sub DD] operating mode for TFTR. Without steady-state current profile control, as the pulse lengths of high [beta]p discharges were extended, l[sub i] decreased, and the improved stability produced immediately after by the current ramp deteriorated. In four second, high [epsilon][beta][sub p] discharges, the current profile broadened under the influence of bootstrap and beam-drive currents. When the calculated voltage throughout the plasma nearly vanished, MHD instabilities were observed with [beta][sub N] as low as 1.4. Ideal MHD stability calculations showed this lower beta limit to be consistent with theoretical expectations.

Manuel, M.E.; Navratil, G.A.; Sabbagh, S.A. (Columbia Univ., New York, NY (United States). Dept. of Applied Physics); Batha, S.; Bell, M.G.; Bell, R.; Budny, R.V.; Bush, C.E.; Cavallo, A.; Chance, M.S.; Cheng, C.Z.; Efthimion, P.C.; Fredrickson, E.D.; Fu, G.Y.; Hawryluk, R.J.; Janos, A.C.; Jassby, D.L.; Levinton, F.; Mikkelsen, D.R.; Manickam, J.; McCune, D.C.; McGuire, K.M.; Medley, S.S.; Mueller, D.; Nagayama, Y.; Owen

1993-04-01

2

Achieving high fusion reactivity in high poloidal beta discharges in TFTR  

SciTech Connect

High poloidal beta discharges have been produced in TFTR that achieved high fusion reactivities at low plasma currents. By rapidly decreasing the plasma current just prior to high-power neutral beam injection, relatively peaked current profiles were created having high l{sub i} > 2, high Troyon-normalized beta, {beta}N > 3, and high poloidal beta. {beta}{sub p} {ge} 0.7 R/a. The global energy confinement time after the current ramp was comparable to supershots, and the combination of improved MHD stability and good confinement produced a new high {epsilon}{beta}{sub p} high Q{sub DD} operating mode for TFTR. Without steady-state current profile control, as the pulse lengths of high {beta}p discharges were extended, l{sub i} decreased, and the improved stability produced immediately after by the current ramp deteriorated. In four second, high {epsilon}{beta}{sub p} discharges, the current profile broadened under the influence of bootstrap and beam-drive currents. When the calculated voltage throughout the plasma nearly vanished, MHD instabilities were observed with {beta}{sub N} as low as 1.4. Ideal MHD stability calculations showed this lower beta limit to be consistent with theoretical expectations.

Manuel, M.E.; Navratil, G.A.; Sabbagh, S.A. [Columbia Univ., New York, NY (United States). Dept. of Applied Physics; Batha, S.; Bell, M.G.; Bell, R.; Budny, R.V.; Bush, C.E.; Cavallo, A.; Chance, M.S.; Cheng, C.Z.; Efthimion, P.C.; Fredrickson, E.D.; Fu, G.Y.; Hawryluk, R.J.; Janos, A.C.; Jassby, D.L.; Levinton, F.; Mikkelsen, D.R.; Manickam, J.; McCune, D.C.; McGuire, K.M.; Medley, S.S.; Mueller, D.; Nagayama, Y.; Owens, D.K.; Park, H.K.; Ramsey, A.T.; Stratton, B.C.; Synakowski, E.J.; Taylor, G.; Wieland, R.M.; Yamada, M.; Zarnstorff, M.C.: Zweben, S. [Princeton Univ., NJ (United States). Plasma Physics Lab.; Kesner, J.; Marmar, E.; Snipes, J.; Terry, J. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Plasma Fusion Center

1993-04-01

3

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

SciTech Connect

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-Schlüter 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. [Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan)] [Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Suzuki, Y. [National Institute for Fusion Science, Toki 509-5292 (Japan)] [National Institute for Fusion Science, Toki 509-5292 (Japan); Shinohara, K.; Matsunaga, G. [Japan Atomic Energy Agency, Naka, Ibaraki 311-0193 (Japan)] [Japan Atomic Energy Agency, Naka, Ibaraki 311-0193 (Japan); Tani, K. [Nippon Advanced Technology, Naka, Ibaraki 311-0102 (Japan)] [Nippon Advanced Technology, Naka, Ibaraki 311-0102 (Japan)

2013-08-15

4

Oligomerization and toxicity of A{beta} fusion proteins  

SciTech Connect

Highlights: {yields} We expressed amyloid-{beta} (A{beta}) peptide as a soluble maltose binding protein fusion (MBP-A{beta}42 and MBP-A{beta}16). {yields} The full length A{beta} peptide fusion, MBP-A{beta}42, forms oligomeric species as determined by SDS-PAGE gels, gel filtration and DLS. {yields} The MBP-A{beta}42, but not MBP-A{beta}16 or MBP alone, is toxic to both yeast and mammalian cells as determined by toxicity assays. -- Abstract: This study has found that the Maltose binding protein A{beta}42 fusion protein (MBP-A{beta}42) forms soluble oligomers while the shorter MBP-A{beta}16 fusion and control MBP did not. MBP-A{beta}42, but neither MBP-A{beta}16 nor control MBP, was toxic in a dose-dependent manner in both yeast and primary cortical neuronal cells. This study demonstrates the potential utility of MBP-A{beta}42 as a reagent for drug screening assays in yeast and neuronal cell cultures and as a candidate for further A{beta}42 characterization.

Caine, Joanne M., E-mail: Jo.Caine@csiro.au [CSIRO Materials Science and Engineering and the Preventive Health Flagship, Parkville, Victoria (Australia); Bharadwaj, Prashant R. [CSIRO Materials Science and Engineering and the Preventive Health Flagship, Parkville, Victoria (Australia) [CSIRO Materials Science and Engineering and the Preventive Health Flagship, Parkville, Victoria (Australia); Centre for Excellence for Alzheimer's Disease Research and Care, School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Western Australia (Australia); Sankovich, Sonia E. [CSIRO Materials Science and Engineering and the Preventive Health Flagship, Parkville, Victoria (Australia)] [CSIRO Materials Science and Engineering and the Preventive Health Flagship, Parkville, Victoria (Australia); Ciccotosto, Giuseppe D. [The Department of Pathology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria 3010 (Australia)] [The Department of Pathology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria 3010 (Australia); Streltsov, Victor A.; Varghese, Jose [CSIRO Materials Science and Engineering and the Preventive Health Flagship, Parkville, Victoria (Australia)] [CSIRO Materials Science and Engineering and the Preventive Health Flagship, Parkville, Victoria (Australia)

2011-06-10

5

Beta > 1 Penning Discharge Fusion Device  

NASA Astrophysics Data System (ADS)

A cold target (fibre(s) or dust, R. Jones, Ind. J. Phys, 55B, 397, 1981 and Ind. J. Phys, 57B, 378, 1983) is heated by high voltage (Megavolt) pulsed power in Penning geometry. The plasma is thermalized by nonclassical processes and electron space charge ion heating (R. Jones, Il Nuovo Cimento, 40B, #2, 261, 1977) and heat is confined by both electrostatic and magnetic insulation while plasma pressure is supported by (wall) inertia (beta > 1). (R. Jones, BAPS, 37, #6, 1474, 1992) More effort needs to be devoted (worldwide) to the study of wall confined plasmas.

Jones, Robert

2010-11-01

6

High-beta steady-state research and future directions on the Japan Atomic Energy Research Institute Tokamak-60 Upgrade and the Japan Atomic Energy Research Institute Fusion Torus-2 Modified  

NASA Astrophysics Data System (ADS)

In the Japan Atomic Energy Research Institute Tokamak-60 Upgrade (JT-60U), a high-?p ELMy H-mode (high-poloidal-beta high-confinement-mode with edge localized mode) plasma was sustained with ?N~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)?ETi(0)=3.1×1020 keV.s.m-3 was achieved using the negative-ion based neutral beam current drive with ?N~2.5 and the bootstrap current fraction fBS~50%. In a hot electron regime, a high electron cyclotron current drive efficiency of 4.2×1018 A/W/m2 was achieved at Te~21 keV. Innovative current start-up scenario produced a current hole plasma with a very high fBS~90%. No accumulation of helium and carbon impurities was observed for internal transport barrier (ITB) plasmas. While argon impurity was accumulated, EC injection effectively exhausted it across ITB. In a regime of ELM disappearance, a clear correlation between the ELM frequency and the toroidal velocity at pedestal was observed. In the Japan Atomic Energy Research Institute Fusion Torus-2 Modified (JFT-2M), high beta plasmas were produced with full ferritic inside wall up to ?N=3.3, where high recycling steady H-mode discharges were developed up to ?NH89P~6 at ne/nGW~0.7-1.0 with ITB. JT-60U started long pulse experiment in late 2003 and JFT-2M will conduct wall stabilization experiment in early 2004. The modification of JT-60 to a fully superconducting coil tokamak is regarded as the national centralized tokamak facility program to accomplish the high beta steady-state research in a collisionless regime.

Ishida, S.; JT-60 Team; JFT-2M Group

2004-05-01

7

Posttranscriptional regulation and assembly into ribosomes of a Saccharomyces cerevisiae ribosomal protein-beta-galactosidase fusion.  

PubMed

To study the regulation of ribosomal protein genes, we constructed a 'lacZ fusion of the Saccharomyces cerevisiae RP51A gene, containing the first 64 codons of RP51A. In a strain lacking an intact RP51A gene (cells are viable due to the presence of an active RP51B gene), beta-galactosidase activity is 10-fold greater than in a strain containing RP51A. RP51A-lacZ mRNA levels are equal in the two strains, indicating that regulation is posttranscriptional. In the absence of the RP51A gene, the fusion protein is predominantly cytoplasmic and associated with polysomes, whereas in the presence of RP51A, the fusion protein is predominantly nuclear, and none is associated with polysomes. Deletions were made in the RP51A-coding portion of the fusion gene. The most extensively deleted gene, containing only the first seven RP51A codons fused to lacZ, produced a high level of beta-galactosidase activity in both the presence and the absence of the RP51A gene. In both cases, little or none of this shorter fusion protein was found associated with polysomes. Thus, a regulatory site (or sites) lies in the protein-coding region of RP51A. We suggest that posttranscriptional regulation of the rp51 fusion protein is related to assembly of the protein into ribosomes. PMID:3939318

Gritz, L; Abovich, N; Teem, J L; Rosbash, M

1985-12-01

8

Cognitive high level information fusion  

Microsoft Academic Search

Fusion of sensor and communication data currently can only be performed at a late processing stage after sensor and textual information are formulated as logical statements at appropriately high level of abstraction. Contrary to this it seems, the human mind integrates sensor and language signals seamlessly, before signals are understood, at pre-conceptual level. Learning of conceptual contents of the surrounding

Leonid I. Perlovsky

2007-01-01

9

Rescue of coronal suture fusion using transforming growth factor-beta 3 (Tgf-beta 3) in rabbits with delayed-onset craniosynostosis.  

PubMed

Craniosynostosis results in cranial deformities and increased intracranial pressure, which pose extensive and recurrent surgical management problems. Developmental studies in rodents have shown that low levels of transforming growth factor-beta 3 (Tgf-beta 3) are associated with normal fusion of the interfrontal (IF) suture, and that Tgf-beta 3 prevents IF suture fusion in a dose-dependent fashion. The present study was designed to test the hypothesis that Tgf-beta 3 can also prevent or "rescue" fusing sutures in a rabbit model with familial craniosynostosis. One hundred coronal sutures from 50 rabbits with delayed-onset, coronal suture synostosis were examined in the present study. The rabbits were divided into five groups of 10 rabbits each: 1) sham controls, 2) bovine serum albumin (BSA, 500 ng) low-dose protein controls, 3) low-dose Tgf-beta 3 (500 ng), 4) high-dose BSA (1,000 ng) controls, and 5) high-dose Tgf-beta 3 (1,000 ng). At 10 days of age, radiopaque amalgam markers were implanted in all of the rabbits on either side of the coronal suture to monitor sutural growth. At 25 days of age, the BSA or Tgf-beta 3 was combined with a slow-absorbing collagen vehicle and injected subperiosteally above the coronal suture. Radiographic results revealed that high-dose Tgf-beta 3 rabbits had significantly greater (P < 0.05) coronal suture marker separation than the other groups. Histomorphometric analysis revealed that high-dose Tgf-beta 3 rabbits also had patent coronal sutures and significantly (P < 0.01) greater sutural widths and areas than the other groups. The results suggest that there is a dose-dependent effect of TGF-beta 3 on suture morphology and area in these rabbits, and that the manipulation of such growth factors may have clinical applications in the treatment of craniosynostosis. PMID:12973720

Chong, Sherri Lyn; Mitchell, Ronal; Moursi, Amr M; Winnard, Phillip; Losken, H Wolfgang; Bradley, James; Ozerdem, Omer R; Azari, Kodi; Acarturk, Oguz; Opperman, Lynne A; Siegel, Michael I; Mooney, Mark P

2003-10-01

10

Efficacy of posterior cervical fusions utilizing an artificial bone graft expander, beta tricalcium phosphate  

PubMed Central

Background: Several cervical laminectomies and instrumented posterior cervical fusions utilize iliac autograft supplemented with demineralized bone matrix, or bone morphogenetic protein, but few utilize artificial bone graft expanders. Here we analyzed whether posterior cervical fusions could effectively utilize iliac autograft supplemented with an artificial bone graft expander, Beta Tricalcium Phosphate [B-TCP] Materials and Methods: Fifty-three severely myelopathic patients [average Nurick Score 4.1], averaging 65.3 years of age, underwent posterior cervical laminectomies [average 2.3 levels] and multilevel instrumented fusions [average 7.5 levels] utilizing iliac crest autograft and B-TCP. Pathology addressed included multilevel spondylosis accompanied by ossification of the posterior longitudinal ligament [24 patients], ossification of the yellow ligament [27 patients], and instability [53 patients]. Fusion rates [dynamic X-ray, two-dimensional computerized axial tomography (2D-CT) and outcomes [Nurick Grades, Odom's Criteria, SF-36] were assessed at 3, 6, and 12 months postoperatively. Results: Fusion was confirmed by two independent neuroradiologists utilizing dynamic X-ray studies [100% of patients] and 2D-CT studies [86.8% of patients] an average of 5.4 months postoperatively. Although there were no symptomatic pseudarthroses, three smokers exhibited delayed fusions [8 postoperative months]. Within 1 postoperative year, patients improved an average of 2.7 Nurick Grades [Nurick Score 1.4], Odom's criteria revealed 48 good/excellent, and 5 fair/poor outcomes, and improvement on all 8 SF-36 Health Scales [maximal on Bodily Pain [+21.96]. Conclusions: High fusion rates and improved neurological outcomes were achieved within one year for 53 patients undergoing multilevel level cervical laminectomies with posterior instrumented fusions utilizing iliac autograft supplemented with B-TCP.

Epstein, Nancy E.

2011-01-01

11

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

12

Neoclassical transport in high [beta] tokamaks  

SciTech Connect

Neoclassical, transport in high [beta] large aspect ratio tokamaks is calculated. The variational method introduced by Rosenbluth, et al., is used to calculate the full Onsager matrix in the banana regime. These results are part of a continuing study of the high [beta] large aspect ratio equilibria introduced in Cowley, et al. All the neoclassical coefficients are reduced from their nominal low [beta] values by a factor ([var epsilon]/q[sup 2][beta])[sup [1/2

Cowley, S.C.

1992-12-01

13

Proteomics computational analyses suggest that the carboxyl terminal glycoproteins of Bunyaviruses are class II viral fusion protein (beta-penetrenes)  

PubMed Central

The Bunyaviridae family of enveloped RNA viruses includes five genuses, orthobunyaviruses, hantaviruses, phleboviruses, nairoviruses and tospoviruses. It has not been determined which Bunyavirus protein mediates virion:cell membrane fusion. Class II viral fusion proteins (beta-penetrenes), encoded by members of the Alphaviridae and Flaviviridae, are comprised of three antiparallel beta sheet domains with an internal fusion peptide located at the end of domain II. Proteomics computational analyses indicate that the carboxyl terminal glycoprotein (Gc) encoded by Sandfly fever virus (SAN), a phlebovirus, has a significant amino acid sequence similarity with envelope protein 1 (E1), the class II fusion protein of Sindbis virus (SIN), an Alphavirus. Similar sequences and common structural/functional motifs, including domains with a high propensity to interface with bilayer membranes, are located collinearly in SAN Gc and SIN E1. Gc encoded by members of each Bunyavirus genus share several sequence and structural motifs. These results suggest that Gc of Bunyaviridae, and similar proteins of Tenuiviruses and a group of Caenorhabditis elegans retroviruses, are class II viral fusion proteins. Comparisons of divergent viral fusion proteins can reveal features essential for virion:cell fusion, and suggest drug and vaccine strategies.

Garry, Courtney E; Garry, Robert F

2004-01-01

14

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

15

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

PubMed

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. PMID:3079747

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

1986-01-01

16

A high-fluence fusion neutron source  

SciTech Connect

A conceptual design of a D-T fusion facility for continuous production of 14-MeV neutron wall loading from 5 to 10 MW/m/sup 2/ at the plasma surface is presented. In this design, D-T neutrons are produced in a linear, two-component plasma formed by neutral beam irradiation of a fully ionized warm plasma target. The beam energy, which is deposited in the center, is transferred to the warm plasma mainly by electron drag and is conducted along the target plasma column to end regions where it is absorbed in neutral gas at high pressure. The target plasma is operated in a regime where electron thermal conduction along the column is the controlling energy-loss process. The loss rate is minimized by adjusting the diameter and length of the plasma column. A substantial gradient in T/sub e/ along the column results in recombination of the plasma to gas in the end-regions before impact on the end walls. The resultant hot gas is cooled by contact with large-area heat exchangers. In this way, the large steady-state heat load from the injected neutral beams is diffused and removed at tolerable heat flux levels. The reacting plasma is essentially an extrapolation of the 2XIIB high-..beta.. plasma to higher magnetic field, ion energy, and density. 12 refs., 4 figs.

Coensgen, F.H.; Casper, T.A.; Correll, D.L.; Damm, C.C.; Futch, A.H.; Logan, B.G.; Molvik, A.W.; Bulmer, R.H.

1988-02-17

17

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

18

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

19

Beta energy driven uniform deuterium--tritium ice layer in reactor-size cryogenic inertial fusion targets  

Microsoft Academic Search

We have studied the effectiveness of beta heating on driving a deuterium--tritium (DT) ice layer toward uniformity within spherical inertial fusion targets. Beta heating results from the deposition of energy from the beta particles from the tritium decay in these targets. These targets are enclosed in a constant temperature environment. This study first considered a one-dimensional heat transfer model of

A. J. Martin; R. J. Simms; R. B. Jacobs

1988-01-01

20

Neoclassical transport in high {beta} tokamaks  

SciTech Connect

Neoclassical, transport in high {beta} large aspect ratio tokamaks is calculated. The variational method introduced by Rosenbluth, et al., is used to calculate the full Onsager matrix in the banana regime. These results are part of a continuing study of the high {beta} large aspect ratio equilibria introduced in Cowley, et al. All the neoclassical coefficients are reduced from their nominal low {beta} values by a factor ({var_epsilon}/q{sup 2}{beta}){sup {1/2}} II. This factor is the ratio of plasma volume in the boundary layer to the volume in the core. The fraction of trapped particles on a given flux surface (f{sub t}) is also reduced by this factor so that {approximately} {sub ({var_epsilon}}/q{sup 2}{beta}){sup {1/2}}. Special attention is given to the current equation, since this is thought to be relevant at low 3 and therefore may also be relevant at high {beta}. The bootstrap current term is found to exceed the actual current by a factor of the square root of the aspect ratio.

Cowley, S.C.

1992-12-01

21

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

22

High Beta Experiments in the GDT Axisymmetric Magnetic Mirror  

NASA Astrophysics Data System (ADS)

This paper reports recent results from the Gas Dynamic Trap magnetic mirror device. Achieving plasma betas up to 60% provides a basis for extrapolating this concept to a fusion relevant 14 MeV neutron source for testing and validating materials applicable to fusion systems.

Simonen, T. C.; Anikeev, A.; Bagryansky, P.; Beklemishev, A.; Ivanov, A.; Lizunov, A.; Maximov, V.; Prikhodko, V.; Tsidulko, Yu.

2010-12-01

23

Kiss-and-run exocytosis and fusion pores of secretory vesicles in human beta-cells.  

PubMed

Exocytosis of secretory vesicles results in the release of insulin from pancreatic beta-cells, although little is known about this process in humans. We examined the exocytosis of single secretory vesicles and their associated fusion pores in human beta-cells by cell-attached capacitance and conductance measurement. Unitary capacitance steps were observed, consistent with the exocytosis of single secretory vesicles. These were often coincident with increases in patch conductance representing the presence of a stable fusion pore. In some events, the fusion pore closed, mediating kiss-and-run, which contributed 20% of the exocytotic events. The cAMP-raising agent forskolin (5 microM) doubled the relative contribution of kiss-and-run. This effect was confirmed visually in MIN6 cells expressing a fluorescent granule probe. Thus, we demonstrate the unitary capacitance steps and fusion pores during single vesicle exocytosis in human beta-cells. Furthermore, these secretory vesicles can undergo rapid recycling by kiss-and-run, and this process is up-regulated by cAMP. PMID:18795319

Hanna, Salma T; Pigeau, Gary M; Galvanovskis, Juris; Clark, Anne; Rorsman, Patrik; MacDonald, Patrick E

2009-04-01

24

High-gain magnetized inertial fusion.  

PubMed

Magnetized inertial fusion (MIF) could substantially ease the difficulty of reaching plasma conditions required for significant fusion yields, but it has been widely accepted that the gain is not sufficient for fusion energy. Numerical simulations are presented showing that high-gain MIF is possible in cylindrical liner implosions based on the MagLIF concept [S. A. Slutz et al Phys. Plasmas 17, 056303 (2010)] with the addition of a cryogenic layer of deuterium-tritium (DT). These simulations show that a burn wave propagates radially from the magnetized hot spot into the surrounding much denser cold DT given sufficient hot-spot areal density. For a drive current of 60 MA the simulated gain exceeds 100, which is more than adequate for fusion energy applications. The simulated gain exceeds 1000 for a drive current of 70 MA. PMID:22324693

Slutz, Stephen A; Vesey, Roger A

2012-01-13

25

High-Gain Magnetized Inertial Fusion  

NASA Astrophysics Data System (ADS)

Magnetized inertial fusion (MIF) could substantially ease the difficulty of reaching plasma conditions required for significant fusion yields, but it has been widely accepted that the gain is not sufficient for fusion energy. Numerical simulations are presented showing that high-gain MIF is possible in cylindrical liner implosions based on the MagLIF concept [S. A. Slutz et al Phys. Plasmas 17, 056303 (2010)PHPAEN1070-664X10.1063/1.3333505] with the addition of a cryogenic layer of deuterium-tritium (DT). These simulations show that a burn wave propagates radially from the magnetized hot spot into the surrounding much denser cold DT given sufficient hot-spot areal density. For a drive current of 60 MA the simulated gain exceeds 100, which is more than adequate for fusion energy applications. The simulated gain exceeds 1000 for a drive current of 70 MA.

Slutz, Stephen A.; Vesey, Roger A.

2012-01-01

26

Enzyme immobilization using a cellulose-binding domain: properties of a beta-glucosidase fusion protein.  

PubMed

Using molecular genetic techniques, a fusion protein has been produced which contains the cellulose-binding domain (CBD) of an exoglucanase (Cex) from Cellulomonas fimi fused to a beta-glucosidase (Abg) from Agrobacterium sp. The CBD functions as an affinity tag for the simultaneous purification and immobilization of the enzyme on cellulose. Binding to cellulose was stable for prolonged periods at temperatures from 4 degrees C to at least 50 degrees C, at ionic strengths from 10 mM to greater than 1 M, and at pH values below 8. The fusion protein can be desorbed from cellulose with distilled water or at pH greater than 8. Immobilized enzyme columns of the fusion protein bound to cotton fibers exhibited stable beta-glucosidase activity for at least 10 days of continuous operation at temperatures up to 37 degrees C. At higher temperatures, the bound enzyme lost activity. The thermal stability of the fusion protein was greatly improved by immobilization. Immobilization did not alter the pH stability. Except for its ability to bind to cellulose, the properties of the fusion protein were virtually the same as those of the native enzyme. PMID:1367528

Ong, E; Gilkes, N R; Miller, R C; Warren, A J; Kilburn, D G

1991-01-01

27

Beta decay of highly charged ions  

NASA Astrophysics Data System (ADS)

Beta decay of highly charged ions has attracted much attention in recent years. An obvious motivation for this research is that stellar nucleosynthesis proceeds at high temperatures where the involved atoms are highly ionized. Another important reason is addressing decays of well-defined quantum-mechanical systems, such as one-electron ions where all interactions with other electrons are excluded. The largest modifications of nuclear half-lives with respect to neutral atoms have been observed in beta decay of highly charged ions. These studies can be performed solely at ion storage rings and ion traps, because there high atomic charge states can be preserved for extended periods of time (up to several hours). Currently, all experimental results available in this field originate from experiments at the heavy-ion complex GSI in Darmstadt. There, the fragment separator facility FRS allows the production and separation of exotic, highly charged nuclides, which can then be stored and investigated in the storage ring facility ESR. In this review, we present and discuss in particular two-body beta decays, namely bound-state beta decay and orbital electron capture. Although we focus on experiments conducted at GSI, we will also attempt to provide general requirements common to any other experiment in this context. Finally, we address challenging but not yet performed experiments and we give prospects for the new radioactive beam facilities, such as FAIR in Darmstadt, IMP in Lanzhou and RIKEN in Wako.

Litvinov, Yuri A.; Bosch, Fritz

2011-01-01

28

Deuterium-tritium TFTR plasmas in the high poloidal beta regime  

SciTech Connect

Deuterium-tritium plasmas with enhanced energy confinement and stability have been produced in the high poloidal beta, advanced tokamak regime in TFTR. Confinement enhancement H {triple_bond} {tau}{sub E}/{tau}{sub E ITER-89P} > 4 has been obtained in a limiter H-mode configuration at moderate plasma current I{sub p} = 0.85 {minus} 1.46 MA. By peaking the plasma current profile, {beta}{sub N dia} {triple_bond} 10{sup 8} < {beta}{sub t{perpendicular}} > aB{sub 0}/I{sub p} = 3 has been obtained in these plasma,s exceeding the {beta}{sub N} limit for TFTR plasmas with lower internal inductance, l{sub i}. Fusion power exceeding 6.7 MW with a fusion power gain Q{sub DT} = 0.22 has been produced with reduced alpha particle first orbit loss provided by the increased l{sub i}.

Sabbagh, S.A.; Mauel, M.E.; Navratil, G.A. [Columbia Univ., New York, NY (United States). Dept. of Applied Physics] [and others

1995-03-01

29

Nuclear fuels for low-beta fusion reactors: Lithium resources revisited  

Microsoft Academic Search

In searching to attain optimum conditions for the controlled release of nuclear energy by fusion processes, the stationary confinement of low-pressure ring-shaped plasmas by strong magnetic fields is now regarded as the most promising approach. We consider a number of fuel combinations that could be operated in such low-beta reactor systems and look upon the relevant fuel reserves. The “classical”

Dieter Eckhartt I

1995-01-01

30

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

NASA Astrophysics Data System (ADS)

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 a flexibility in fabrication processes. Specimens were irradiated in a test reactor to a fluence of 5.3 x 10 to the 22nd power n/sq m, E 0.1 MeV, and 4.9 x 10 to the 23rd power n/sq m 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 were also investigated.

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

31

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

32

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

33

Information Fusion for High Level Situation Assessment and Prediction.  

National Technical Information Service (NTIS)

This is the final report for our AFOSR sponsored project: Information Fusion for High Level Situation Assessment and Prediction. Through this project, we developed a probabilistic framework for performing high level information fusion. In addition, we dev...

Q. Ji

2007-01-01

34

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

35

Measuring the Value of High Level Fusion  

Microsoft Academic Search

In most current ground force combat simulations, the operational movements and command intent of forces follow prescribed, inflexible objectives and plans. Because of this limitation, the value of advanced intelligence, surveillance, and reconnaissance (ISR) and high-level fusion is reflected only in better targeting and not in improved operational-level command and control (C2). RAND has developed an agent interaction-based constructive simulation

Louis R. Moore; Daniel Gonzales

36

Application of high temperature superconductors for fusion  

Microsoft Academic Search

The use of High Temperature Superconductor (HTS) materials in future fusion machines can increase the efficiency drastically. For ITER, W7-X and JT-60SA the economic benefit of HTS current leads was recognized after a 70kA HTS current lead demonstrator was designed, fabricated and successfully tested by Karlsruhe Institute of Technology (KIT, which is a merge of former Forschungszentrum Karlsruhe and University

W. H. Fietz; R. Heller; S. I. Schlachter; W. Goldacker

2011-01-01

37

In-vessel tritium measurements using beta decay in the Tokamak Fusion Test Reactor  

SciTech Connect

Tritium on the inside walls of the Tokamak Fusion Test Reactor was detected by configuring the vacuum vessel as an ionization chamber and measuring the secondary electron current from the tritium beta decay. The vessel was typically filled with {approx}5 Torr of dry nitrogen and the secondary electron current was collected by an internal electrode biased to about +15 V with respect to the vessel wall. The measured variations of the collected current with gas pressure, bias voltage, and applied magnetic fields are described, as well as an {ital in situ} calibration made by injecting a known amount of tritium gas. Improved versions of this diagnostic may be useful to track the in-vessel content of surface tritium in future fusion devices. {copyright} {ital 1999 American Institute of Physics.}

Zweben, S.J.; Gentile, C.; Mueller, D.; Nagy, A.; Pearson, G.; Skinner, C.H.; Walsh, J. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)

1999-01-01

38

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

NASA Astrophysics Data System (ADS)

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 × 10 22 n/m 2, E > 0.1 MeV, and 4.9 × 10 23 n/m 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 betaspodumene are little affected by irradiation. Gas production and release have also been investigated.

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

39

Introducing semantic knowledge in high-level fusion  

Microsoft Academic Search

The necessity of taking into account high-level information has recently been reported by the information fusion community. We previously presented an approach for high-level symbolic fusion that relies on the use of the conceptual graphs model. Domain knowledge is a major point of the fusion process. The use of conceptual graphs for knowledge representation eases the process of expressing domain

Claire LAUDY; Jean-Gabriel GANASCIA

2009-01-01

40

Transport in high normalized beta discharges on ASDEX Upgrade  

Microsoft Academic Search

An advanced high confinement mode scenario with normalized beta (betaN) up to 3.5 in stationary conditions (up to 20 energy confinement times) and betaN = 3.8 transiently, has been obtained in ASDEX Upgrade. For transport analysis of high betaN discharges, two types of simulations have been performed with the automated system for transport analysis code. One is the simulation of

Yong-Su Na; A. C. C. Sips; O. Gruber; J. Hobirk; G. Pereverzev

2002-01-01

41

Anterior cervical fusion with a bio-resorbable composite cage (beta TCP–PLLA): clinical and radiological results from a prospective study on 20 patients  

Microsoft Academic Search

A resorbable composite material (40% PLLA and 60% beta TCP) with a high breaking strength and capacity to withstand plastic\\u000a and elastic strain has been developed for cervical interbody fusion. This is a prospective study to evaluate clinical and\\u000a radiological results of 20 patients implanted with 27 cages (mean follow-up, 27 months). Clinical (neck disability index,\\u000a VAS, neurological evaluation) and radiological

F. Debusscher; S. Aunoble; Y. Alsawad; D. Clement; Jean-Charles Le Huec

2009-01-01

42

High Energy Space Propulsion based on Magnetized Target Fusion  

Microsoft Academic Search

Magnetized Target Fusion (MTF) is a new entry into the fusion propulsion arena that promises low-cost development and rapid deployment using existing facilities and technology. Plasma-jet driven MTF has a number of features which make it attractive as a space propulsion system. These features include, low system mass and volume, high Isp and thrust, and efficient fusion drivers leading to

F. Thio

1999-01-01

43

Beta decay of highly charged ions  

NASA Astrophysics Data System (ADS)

A brief overview is presented in this paper on some experiments conducted at the Experimental Storage Ring (ESR) of GSI which addressed the ? decay of stored and cooled highly charged ions. Special emphasis is placed on the two-body beta decay of bare or few-electron ions: bound-state ?- decay (?b) and its time-mirrored counterpart, orbital electron capture. The former decay mode was detected experimentally 20 years ago at the ESR. The latter could be investigated there for the first time in detail for the simplest quantum systems: hydrogen- and helium-like atoms. The main results of these experiments will be presented. Also their impact on stellar nucleosynthesis, in particular the s-process, is discussed.

Bosch, F.; Atanasov, D. R.; Brandau, C.; Dillmann, I.; Dimopoulou, C.; Faestermann, T.; Geissel, H.; Hagmann, S.; Hillenbrand, P.-M.; Kienle, P.; Knöbel, R.; Kozhuharov, C.; Kurcewicz, J.; Lestinsky, M.; Litvinov, S. A.; Litvinov, Yu A.; Ma, X.; Nolden, F.; Ohtsubo, T.; Patyk, Z.; Reuschl, R.; Sanjari, M. S.; Scheidenberger, C.; Shubina, D.; Spillmann, U.; Steck, M.; Stöhlker, Th; Sun, B.; Trassinelli, M.; Trotsenko, S.; Tu, X. L.; Weick, H.; Winckler, N.; Winkler, M.; Winters, D. F. A.; Yamaguchi, T.; Yan, X. L.

2013-09-01

44

Gyrokinetic turbulence simulations at high plasma beta  

SciTech Connect

Electromagnetic gyrokinetic turbulence simulations employing Cyclone Base Case parameters are presented for {beta} values up to and beyond the kinetic ballooning threshold. The {beta} scaling of the turbulent transport is found to be linked to a complex interplay of linear and nonlinear effects. Linear investigation of the kinetic ballooning mode is performed in detail, while nonlinearly, it is found to dominate the turbulence only in a fairly narrow range of {beta} values just below the respective ideal limit. The magnetic transport scales like {beta}{sup 2} and is well described by a Rechester-Rosenbluth-type ansatz.

Pueschel, M. J.; Kammerer, M.; Jenko, F. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, D-85748 Garching (Germany)

2008-10-15

45

Ion nitriding of titanium alpha plus beta alloy for fusion reactor applications  

NASA Astrophysics Data System (ADS)

The titanium alpha plus beta alloy, Ti-6Al-4V, has been plasma nitrided at 1033 K in pure nitrogen to produce a 9 ?m thick surface nitride zone, followed by a 5 ?m thick Al-enriched zone and a 100 ?m thick nitrogen diffusion zone. X-ray diffraction and Auger electron spectroscopy indicate that the nitride zone consists of two layers: a thin TiN layer at the surface followed by a Ti 2N layer. In preliminary tests, the deuterium retention of nitrided titanium specimens was determined after exposure to fluences of 4×10 25 m -2, 60 eV D + ions at 440 K and of 2×10 25 m -2, 800 eV D + ions at 623 K. The results are compared to the retention found for similar exposure of the untreated alloy and to model simulations. Implications for the use of these materials in a fusion environment are discussed.

Rolinski, E.; Sharp, G.; Cowgill, D. F.; Peterman, D. J.

1998-02-01

46

Thermostable beta-glycosidase-CBD fusion protein for biochemical analysis of cotton scouring efficiency.  

PubMed

Multidomain proteins for the biochemical analysis of the scouring efficiency of cotton fabrics were constructed by the fusion of a reporter moiety in the N-terminal and the cellulose binding domain (CBD) in the C-terminal. Based on the specific binding of the CBD of Cellulomonas fimi exoglucanase (Cex) to crystalline cellulose (Avicel), the reporter protein is guided to the cellulose fibers that are increasingly exposed as the scouring process proceeds. Among the tested reporter proteins, a thermostable beta-glycosidase (BglA) from Thermus caldophilus was found to be most appropriate, showing a higher applicability and stability than GFP, DsRed, or a tetrameric beta-glucuronidase (GUS) from Escherichia coli, which were precipitated more seriously during the expression and purification steps. When cotton fabrics with different scouring levels were treated with the BglA-CBD and incubated with X-Gal as the chromogenic substrate, an indigo color became visible within 2 h, and the color depth changed according to the conditions and extent of the scouring. PMID:18388460

Ha, Jae-Seok; Lee, Young-Mi; Choi, Su-Lim; Song, Jae Jun; Shin, Cheol-Soo; Kim, Ju-Hea; Lee, Seung-Goo

2008-03-01

47

Progress toward fully noninductive, high beta conditions in DIII-D  

NASA Astrophysics Data System (ADS)

The DIII-D Advanced Tokamak (AT) program in the DIII-D tokamak [J. L. Luxon, Plasma Physics and Controlled Fusion Research, 1986, Vol. I (International Atomic Energy Agency, Vienna, 1987), p. 159] is aimed at developing a scientific basis for steady-state, high-performance operation in future devices. This requires simultaneously achieving 100% noninductive operation with high self-driven bootstrap current fraction and toroidal beta. Recent progress in this area includes demonstration of 100% noninductive conditions with toroidal beta, ?T=3.6%, normalized beta, ?N=3.5, and confinement factor, H89=2.4 with the plasma current driven completely by bootstrap, neutral beam current drive, and electron cyclotron current drive (ECCD). The equilibrium reconstructions indicate that the noninductive current profile is well aligned, with little inductively driven current remaining anywhere in the plasma. The current balance calculation improved with beam ion redistribution that was supported by recent fast ion diagnostic measurements. The duration of this state is limited by pressure profile evolution, leading to magnetohydrodynamic (MHD) instabilities after about 1 s or half of a current relaxation time (?CR). Stationary conditions are maintained in similar discharges (~90% noninductive), limited only by the 2 s duration (1?CR) of the present ECCD systems. By discussing parametric scans in a global parameter and profile databases, the need for low density and high beta are identified to achieve full noninductive operation and good current drive alignment. These experiments achieve the necessary fusion performance and bootstrap fraction to extrapolate to the fusion gain, Q=5 steady-state scenario in the International Thermonuclear Experimental Reactor (ITER) [R. Aymar et al., Fusion Energy Conference on Controlled Fusion and Plasma Physics, Sorrento, Italy (International Atomic Energy Agency, Vienna, 1987), paper IAEA-CN-77/OV-1]. The modeling tools that have been successfully employed to both plan and interpret the experiment are used to plan future DIII-D experiments with higher power and longer pulse ECCD and fast wave and co- and counterneutral beam injection in a pumped double-null configuration. The models predict our ability to control the current and pressure profiles to reach full noninductivity with increased beta, bootstrap fraction, and duration. The same modeling tools are applied to ITER, predicting favorable prospects for the success of the ITER steady-state scenario.

Murakami, M.; Wade, M. R.; Greenfield, C. M.; Luce, T. C.; Ferron, J. R.; John, H. E. St.; Deboo, J. C.; Heidbrink, W. W.; Luo, Y.; Makowski, M. A.; Osborne, T. H.; Petty, C. C.; Politzer, P. A.; Allen, S. L.; Austin, M. E.; Burrell, K. H.; Casper, T. A.; Doyle, E. J.; Garofalo, A. M.; Gohil, P.; Gorelov, I. A.; Groebner, R. J.; Hyatt, A. W.; Jayakumar, R. J.; Kajiwara, K.; Kessel, C. E.; Kinsey, J. E.; La Haye, R. J.; Lao, L. L.; Leonard, A. W.; Lohr, J.; Petrie, T. W.; Pinsker, R. I.; Prater, R.; Rhodes, T. L.; Sips, A. C. C.; Staebler, G. M.; Taylor, T. S.; Vanzeeland, M. A.; Wang, G.; West, W. P.; Zeng, L.; DIII-D Team

2006-05-01

48

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

49

High Level Information Fusion developments, issues, and grand challenges: Fusion 2010 panel discussion  

Microsoft Academic Search

The goal of the High-Level Information Fusion (HLIF) Panel Discussion is to present contemporary HLIF advances and developments to determine unsolved grand challenges and issues. The discussion will address the issues between low-level (signal processing and object state estimation and characterization) and high-level information fusion (control, situational understanding, and relationships to the environment). Specific areas of interest include modeling (situations,

Erik Blasch; James Llinas; Dale Lambert; Pierre Valin; Subrata Das; Chee Chong; Mitch Kokar; Elisa Shahbazian

2010-01-01

50

The clinical use of enriched bone marrow stem cells combined with porous beta-tricalcium phosphate in posterior spinal fusion  

Microsoft Academic Search

Cytotherapy for bone regeneration has not been widely used clinically. A new method based on enriched bone-marrow-derived mesenchymal stem cells (MSCs) combined with porous beta-tricalcium phosphate (?-TCP) was used for posterior spinal fusion in 41 patients. The aim of the present study was to assess the clinical feasibility of peri-operative bone marrow stem cell enrichment and their combination with tricalcium

Yaokai Gan; Kerong Dai; Pu Zhang; Tingting Tang; Zhenan Zhu; Jianxi Lu

2008-01-01

51

High-beta Plasmas Confined in Poloidal Magnetic Fields.  

National Technical Information Service (NTIS)

Experiments on rotating plasmas providing methods for studying the important problems of plasma equilibrium and stability at high beta values are described. The investigations were performed by means of probe and Rogowsky coil recordings. It was found tha...

B. Lehnert T. Hellsten R. Raggi

1972-01-01

52

Environmentally Assisted Cracking of High Strength Beta Titanium Alloys.  

National Technical Information Service (NTIS)

The objective of this integrated research program is to define the conditions under which high strength Beta-titanium alloys resist environmentally assisted cracking (EAC) in marine environments. Specific goals are to: (1) characterize EAC for metallurgic...

R. P. Ganglogg J. R. Scully R. G. Kelly

1994-01-01

53

Environmentally Assisted Cracking of High Strength Beta Titanium Alloys.  

National Technical Information Service (NTIS)

The objective of this research is to define the conditions under which high strength beta-titanium alloys are resistant to environmentally assisted cracking (EAC) in marine environments. Our goals are to: (1) characterize environment enhanced subcritical ...

J. R. Scully R. P. Gangloff L. M. Young G. A. Young D. G. Kolman

1992-01-01

54

Muon catalyzed fusion in plasma state and high intensity DT fusion neutron source  

Microsoft Academic Search

dt\\/mu\\/ molecular formation rates in a plasma state of DT mixture by d and t ions are, respectively, 63 and 77 times higher than the ones by electrons. High plasma oscillation frequency in a high electron density plasma enhances the formation rate in the high temperature dt mixture. The DT muon catalyzed fusion has the ability to produce much higher

Hiroshi

1989-01-01

55

High temperature superconducting current leads for fusion magnet systems.  

National Technical Information Service (NTIS)

Superconducting magnets for fusion applications typically have very high operating currents. These currents are transmitted from the room temperature power supplies to the low temperature superconducting coils by way of helium-vapor-cooled current leads. ...

J. L. Wu J. T. Dederer S. K. Singh J. R. Hull

1991-01-01

56

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

57

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

58

Issues of Uncertainty Analysis in High-Level Information Fusion  

Microsoft Academic Search

High-Level Information Fusion (HLIF) utilizes techniques from Low-Level Information Fusion (LLIF) to support situation\\/impact assessment, user involvement, and mission and resource management (SUM). Given the unbounded analysis of situations, events, users, resources, and missions; it is obvious that uncertainty is manifested by the nature of application requirements. In this panel, we seek discussions on methods and techniques to intelligently assess

Erik Blasch; Paulo Cesar G. Da Costa; Kathryn B. Laskey; Dafni Stampouli; Gee Wah Ng; Johan Schubert; Rakesh Nagi; Pierre Valin

2012-01-01

59

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

60

Expression and characterization of a tripartite fusion protein consisting of chimeric IgG-binding receptors and beta-galactosidase.  

PubMed

Using protein engineering, a tripartite fusion protein was constructed consisting of five IgG-binding regions of protein A from Staphylococcus aureus, two IgG-binding regions of protein G from Streptococcus strain G148 and beta-galactosidase from Escherichia coli. The resulting protein lacks the serum albumin binding regions of native protein G. The fusion protein, which is a tetramer of approximately 660 kDa, was designed as a tool for immunological assays taking advantage of its broad spectrum of antibody affinity. The gene was placed under control of two promoters, the PR promoter and the lac UV5 promoter and the expression from the two promoters was studied in a bioreactor. Induction of the PR promoter gave an intracellular product concentration corresponding to 20% of the cell dry weight. By utilizing the properties of beta-galactosidase, the protein was purified by extraction in an aqueous two-phase system. The fusion protein was not proteolytically degraded during the cultivation and purification steps. The biological activity of all three parts of the protein was demonstrated with a competitive ELISA. PMID:1368543

Strandberg, L; Hober, S; Uhlén, M; Enfors, S O

1990-01-01

61

The binding affinity of a soluble TCR-Fc fusion protein is significantly improved by crosslinkage with an anti-C{beta} antibody  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer A novel soluble TCR composed of TCR V and C regions with Ig Fc region is generated. Black-Right-Pointing-Pointer TCR-Fc protein immobilized by an anti-C{beta} antibody bound to a p/MHC tetramer. Black-Right-Pointing-Pointer Binding affinity of TCR-Fc was markedly increased by binding with anti-C{beta} antibody. -- Abstract: The identification and cloning of tumor antigen-specific T cell receptors (TCRs) and the production of the soluble form of the TCR (sTCR) contributed to the development of diagnostic and therapeutic tools for cancer. Recently, several groups have reported the development of technologies for the production of sTCRs. The native sTCR has a very low binding affinity for the antigenic peptide/MHC (p/MHC) complex. In this study, we established a technology to produce high affinity, functional sTCRs. We generated a novel sTCR-Fc fusion protein composed of the TCR V and C regions of the TCR linked to the immunoglobulin (Ig) Fc region. A Western blot analysis revealed that the molecular weight of the fusion protein was approximately 60 kDa under reducing conditions and approximately 100-200 kDa under non-reducing conditions. ELISAs using various antibodies showed that the structure of each domain of the TCR-Fc protein was intact. The TCR-Fc protein immobilized by an anti-C{beta} antibody effectively bound to a p/MHC tetramer. An SPR analysis showed that the TCR-Fc protein had a low binding affinity (KD; 1.1 Multiplication-Sign 10{sup -5} M) to the p/MHC monomer. Interestingly, when the TCR-Fc protein was pre-incubated with an anti-C{beta} antibody, its binding affinity for p/MHC increased by 5-fold (2.2 Multiplication-Sign 10{sup -6} M). We demonstrated a novel method for constructing a functional soluble TCR using the Ig Fc region and showed that the binding affinity of the functional sTCR-Fc was markedly increased by an anti-C{beta} antibody, which is probably due to the stabilization of the V{alpha}/V{beta} region of the TCR. These findings provide new insights into the binding of sTCRs to p/MHCs and will hopefully be instrumental in establishing functional sTCR as a diagnostic and therapeutic tool for cancer.

Ozawa, Tatsuhiko; Horii, Masae; Kobayashi, Eiji [Department of Immunology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194 (Japan)] [Department of Immunology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194 (Japan); Jin, Aishun [Department of Immunology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194 (Japan) [Department of Immunology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194 (Japan); Department of Immunology, College of Basic Medical Sciences, Harbin Medical University, 157 Baojian Road, Nangang District, Harbin 150081 (China); Kishi, Hiroyuki, E-mail: immkishi@med.u-toyama.ac.jp [Department of Immunology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194 (Japan)] [Department of Immunology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194 (Japan); Muraguchi, Atsushi [Department of Immunology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194 (Japan)] [Department of Immunology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194 (Japan)

2012-06-01

62

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

63

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; Søren 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

64

Kinetic high-beta equilibria in a plasma slab  

SciTech Connect

Self-consistent, high-beta kinetic equilibria are derived from the Vlasov equation for a plasma slab in a nonzero magnetic field with a density gradient and a gravitational field. It is shown that a magnetic field inhomogeneity and an electric field arise as necessary consequences of the high-beta state. Hence the corresponding equilibrium forces should not be neglected in calculations of individual particle motion. Explicit expressions are derived for equilibrium quantities, useful, e.g., for large Larmor radius (LLR) studies of the Rayleigh--Taylor instability.

Li, J.; Scheffel, J. (Royal Inst. of Tech., Stockholm (Sweden). Dept. of Plasma Physics and Fusion Research)

1991-09-01

65

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

PubMed

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 (beta4Gal-T7), in E. coli. The enzyme beta4Gal-T7 transfers galactose to xylose during the synthesis of the tetrasaccharide linker sequence attached to a Ser residue of proteoglycans. Without a fusion partner, beta4Gal-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-beta4Gal-T7 fusion protein, the unique protease cleavage site allows the protein beta4Gal-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 beta4Gal-T1. The engineered galectin-1 vector could prove to be a valuable tool for expressing other proteins in E. coli. PMID:20226765

Pasek, Marta; Boeggeman, Elizabeth; Ramakrishnan, Boopathy; Qasba, Pradman K

2010-04-01

66

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

67

Logical Traps in High-Level Knowledge and Information Fusion.  

National Technical Information Service (NTIS)

In this paper, we are concerned with high-level information fusion, such as it is envisioned in JDL levels 4 and 5. More precisely, the focus is on decision and reasoning systems that must act in a rational and logical way from several knowledge and high-...

E. Gregoire

2006-01-01

68

Logical Traps in High-Level Knowledge and Information Fusion  

Microsoft Academic Search

In this paper, we are concerned with high-level information fusion, such as it is envisioned in JDL levels 4 and 5. More precisely, the focus is on decision and reasoning systems that must act in a rational and logical way from several knowledge and high-level information sources and databases. Whatever the selected knowledge and information representation languages in the sources

Éric Grégoire; CRIL CNRS

69

Fusion  

NASA Astrophysics Data System (ADS)

Acknowledgments; 1. The invention of Dr Spitzer; 2. Behind closed doors; 3. Friends and rivals; 4. Searching for answers; 5. Dawn of the tokamak; 6. Building big science; 7. Forming the major league; 8. The political plasma; 9. The modern fusion lab; 10. The plasma olympics; 11. Different directions; 12. Struggling to sell fusion; 13. In sight of breakeven; 14. Fusion's past and future; Notes; Glossary; Appendices; Index.

Herman, Robin

2006-03-01

70

High Level Sensor Data Fusion Approaches For Object Recognition In Road Environment  

Microsoft Academic Search

Application of high level fusion approaches demonstrate a sequence of significant advantages in multi sensor data fusion and automotive safety fusion systems are no exception to this. High level fusion can be applied to automotive sensor networks with complementary or\\/and redundant field of views. The advantage of this approach is that it ensures system modularity and allows benchmarking, as it

Nikos Floudas; Aris Polychronopoulos; Olivier Aycard; Julien Burlet; Malte Ahrholdt

2007-01-01

71

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

72

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

73

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

74

Quasi-isodynamic Configuration With N = 12 and High {beta}  

SciTech Connect

Results of an optimization toward quasi-isodynamicity for a stellarator with a comparatively large number of periods, N = 12, are presented. The following set of physics properties to be achieved was used: 1) good long-time collisionless confinement of {alpha}-particles; 2) small neoclassical transport in the 1/{nu} regime; 3) small bootstrap current; 4) high stability-{beta} limit. As a result, the boundary magnetic surface of a configuration is found that satisfies the above requirements for <{beta}> {approx_equal} 20%.

Mikhailov, M. I.; Isaev, M. Yu.; Subbotin, A. A.; Shafranov, V. D. [Russian Research Centre 'Kurchatov Institute', Moscow (Russian Federation); Nuehrenberg, C.; Nuehrenberg, J.; Zille, R. [Max-Planck-Institut fuer Plasmaphysik, IPP-EURATOM Association (Germany); Cooper, A. [CRPP, Association Euratom-Confederation Suisse, EPFL, Lausanne (Switzerland)

2006-11-30

75

Nebivolol: more than a highly selective Beta blocker.  

PubMed

Although their specific mechanisms of action are incompletely understood, beta blockers are most likely lower blood pressure and provide target organ protection by several different mechanisms, including inhibition of renin-angiotensine system by decreasing renin release by the jugstaglomerular cells of the kidney, central inhibition of sympathetic nervous system outflow and slowing of heart rate with a decrease in cardiac output. These agents are widely recommended as important parts of antihypertensive regimens and as well as preferred therapies for patients at high risks of coronary heart disease, and including those with angina pectoris, myocardial infarction or heart failure. The third generation beta blockers are distinguished from the earlier class of beta blockers by their vasodilating activity. Labetalol, carvedilol and bucindolol appear to provide a vasodilation primarily through their blockade of alpha-1 rerceptors. Nebivolol is a lipophilic beta reseptor blocker of third generation with distinct beta-1 with selective and vasodilating properties. A number of experimental and human pharmological studies suggest that the vasodilatation is triggered via increasing vascular NO bioavailabilty which is a consequence of stimulation of NO release and antioxidant properties of this compound. The pharmocological profile is characterised by the significant antihypertensive effect as well as lowering of cardiac pre and after load. Nebivolol is well tolerated and does not appear to significantly influence glucose or plasma lipid metabolism. It is devoid of intrinsic sympathomimetic activity (ISA). This article will review patents, novel composition, pharmacology, haemodynamics, antihypertensive efficiency, metabolic effect and tolerability of nebivolol. PMID:18221115

Karter, Yesari

2007-06-01

76

Impact of MHD Equilibrium Input Variations on the High-Beta Stability Boundaries of NSTX  

SciTech Connect

Ideal MHD stability limits of anticipated plasma configurations for the National Spherical Torus Experiment (NSTX) [Ono, M., et al., Nucl. Fusion 40 (2000) 557] and the dependence on the parameters defining the MHD equilibrium are evaluated. The study provides a quantitative computational evaluation of the stability limit variations induced by changes to the equilibrium of NSTX high-beta plasmas. The analysis is based on a reference free-boundary equilibrium with beta = 41.5%, monotonic safety factor q profile, and broad pressure profile p. On this reference target local variation of the plasma boundary, safety factor q, and pressure p profiles are imposed. Localized inflection of the outboard plasma boundary, produced by near-field effects from poloidal shaping field coils, weaken the stability due to the destabilization of high-n ballooning modes. Variation of the q profile at different radial location can also degrade stability. Both experimental profiles from existing tokamaks and spherical torus machines and profiles generated from transport modeling of anticipated neutral-beam-heated plasmas are used. Degraded stability is found at increasing pressure peaking factor due to the destabilization of n = 1 kink/ballooning modes. Direct access to the second region of stability is found in certain configurations and, for the entire set of variations considered, the lower calculated beta-limits values are still in the range of 20.0% without considering the stabilizing effect of the passive conducting structures.

F. Paoletti; S.A. Sabbagh; J. Manickam; J. Menard; R.J. Akers; D. Gates; S.M. Kaye; L. Lao

2001-03-20

77

Indirectly driven, high convergence inertial confinement fusion implosions  

Microsoft Academic Search

A series of high convergence indirectly driven implosions has been done with the Nova Laser Fusion facility. These implosions were well characterized by a variety of measurements; computer models are in good agreement. The imploded fuel areal density was measured using a technique based on secondary neutron spectroscopy. At capsule convergences of 24:1, comparable to what is required for the

M. D. Cable; S. P. Hatchett; J. A. Caird; J. D. Kilkenny; H. N. Kornblum; C. Laumann; R. A. Lerche; T. J. Murphy; M. B. Nelson; D. W. Phillion; H. Powell; D. B. Ress

1994-01-01

78

Some experiences with experimental high level fusion systems  

Microsoft Academic Search

A very short overview is given on experience gained in the area of high level information fusion (JDL level 2 and 3) since 1988. The main characteristics of the referenced projects and experimental systems for the support of intelligence officers in land battle missions will be outlined. The different approaches to analyse and model military intelligence processing and the development

J. Biermann

2007-01-01

79

Hierarchical High Level Information Fusion (H2LIFT).  

National Technical Information Service (NTIS)

The primary objective of this effort was the progression of Level 2/3 fusion of informational content to obtain an advanced multi-intelligent system for hierarchical high-level decision making processes. The goal was to develop an information integration ...

A. Crassidis A. Stotz J. Crassidis M. Sudit R. Nagi

2008-01-01

80

Super-X divertors and high power density fusion devices  

NASA Astrophysics Data System (ADS)

The Super-X Divertor (SXD), a robust axisymmetric redesign of the divertor magnetic geometry that can allow a fivefold increase in the core power density of toroidal fusion devices, is presented. With small changes in poloidal coils and currents for standard divertors, the SXD allows the largest divertor plate radius inside toroidal field coils. This increases the plasma-wetted area by 2-3 times over all flux-expansion-only methods (e.g., plate near main X point, plate tilting, X divertor, and snowflake), decreases parallel heat flux and hence plasma temperature at plate, and increases connection length by 2-5 times. Examples of high-power-density fusion devices enabled by SXD are discussed; the most promising near-term device is a 100 MW modular compact fusion neutron source ``battery'' small enough to fit inside a conventional fission blanket.

Valanju, P. M.; Kotschenreuther, M.; Mahajan, S. M.; Canik, J.

2009-05-01

81

Super-X Divertors and High Power Density Fusion Devices  

SciTech Connect

The Super-X Divertor (SXD), a robust axisymmetric redesign of the divertor magnetic geometry that can allow a fivefold increase in the core power density of toroidal fusion devices, is presented. With small changes in poloidal coils and currents for standard divertors, the SXD allows the largest divertor plate radius inside toroidal field coils. This increases the plasma-wetted area by 2-3 times over all flux-expansion-only methods (e.g., plate near main X point, plate tilting, X divertor, and snowflake), decreases parallel heat flux and hence plasma temperature at plate, and increases connection length by 2-5 times. Examples of high-power-density fusion devices enabled by SXD are discussed; the most promising near-term device is a 100 MW modular compact fusion neutron source "battery" small enough to fit inside a conventional fission blanket.

Valanju, P. [University of Texas, Austin; Kotschenreuther, M. [University of Texas, Austin; Mahajan, S. [University of Texas, Austin; Canik, John [ORNL

2009-01-01

82

High-level fusion based on conceptual graphs  

Microsoft Academic Search

Most of studies in the field of information fusion focus on the production of high-level information from low-level data. The challenge is then to fuse this high-level information to produce a global and coherent information. Another approach consists in interpreting data as high-level information and fuse it at once. Our approach relies on the use of conceptual graphs model. The

Claire Laudy; Jean-Gabriel Ganascia; Célestin Sedogbo

2007-01-01

83

Hampton University (hu) Center for Fusion Research & Training (cfrt) Summer High School Fusion Science Workshops: 1996 Through 2000  

Microsoft Academic Search

The HU CFRT has conducted Summer High School Fusion Science Energy Workshops during the summers of 1996 through 2000 - a total of five summer fusion science workshops for high school students. These workshops are one of many programs and activities of the center organized and focused around the education, motivation, retention and research experiences for young scholars especially under-represented

Alkesh Punjabi; Halima Ali; Ellis Rhonda; Vincent Tucker

2001-01-01

84

Helicon Sources for High Beta Space Physics Experiments  

NASA Astrophysics Data System (ADS)

The West Virginia University helicon source was constructed to provide plasma for experiments designed to investigate naturally occurring magnetospheric phenomena. The terrestrial magnetosphere is a collisionless, high beta plasma whose dynamics is heavily influenced by the action of kinetic instabilities, i.e., instabilities driven by non-Maxwellian particle distributions. For the past four years, we have been investigating electromagnetic instabilities driven by ion temperature anisotropy. The intrinsic ion heating that occurs in our helicon source [Scime et al., Plasma Sources Sci. and Technol. 7, 186-191, 1998] enables us to generate highly anisotropic plasmas. The plasma expands into a large, low magnetic field chamber where the instabilities develop and are studied. We will present a summary of our measurements of ion temperature anisotropy versus ion beta as well as our measurements of the characteristics of the observed electromagnetic fluctuations. The inverse scaling of ion temperature anisotropy with ion beta predicted by theory is observed in the experiment. Although the laboratory plasma is collisional, the collisional properties of the system were held constant and the inverse scaling of ion temperature anisotropy with ion beta was still observed. Throughout this presentation, we will emphasize how the unique capabilities of the WVU helicon source have enabled these experiments to be performed.

Scime, Earl; Boivin, Robert; Kline, John; Spangler, Robert; Sun, Xuan; Keiter, Paul; Balkey, Matthew

2001-10-01

85

Effect of resonant and non-resonant magnetic braking on error field tolerance in high beta plasmas  

NASA Astrophysics Data System (ADS)

Tokamak plasmas become less tolerant to externally applied non-axisymmetric magnetic 'error' fields as beta increases, due to a resonant interaction of the non-axisymmetric field with a stable n = 1 kink mode. Similar to observations in low beta plasmas, the limit to tolerable n = 1 magnetic field errors in neutral beam injection heated H-mode plasmas is seen as a bifurcation in the torque balance, which is followed by error field-driven locked modes and severe confinement degradation or a disruption. The error field tolerance is, therefore, largely determined by the braking torque resulting from the non-axisymmetric magnetic field. DIII-D experiments distinguish between a resonant-like torque, which decreases with increasing rotation, and a non-resonant-like torque, which increases with increasing rotation. While only resonant braking leads to a rotation collapse, modelling shows that non-resonant components can lower the tolerance to resonant components. The strong reduction of the error field tolerance with increasing beta, which has already been observed in early high beta experiments in DIII-D (La Haye et al 1992 Nucl. Fusion 32 2119), is linked to an increasing resonant field amplification resulting from a stable kink mode (Boozer 2001 Phys. Rev. Lett. 86 5059). The amplification of externally applied n = 1 fields is measured with magnetic pick-up coils at normalized beta values as low as 1 and seen to increase with beta. The rate at which the amplification increases with beta becomes larger above the no-wall ideal MHD stability limit, where kinetic effects stabilize the resistive wall mode. The extent of the beta dependence and its importance for low torque scenarios was not previously appreciated, and was not included in the empirical scaling of the error field tolerance for ITER, which focused on the lowest density phase of a discharge prior to H-mode access (Buttery et al 1999 Nucl. Fusion 39 1827, 1999 ITER Physics Basis Nucl. Fusion 39 2137). However, the measurable increase in the plasma response with beta can be exploited for 'dynamic' correction (i.e. with slow magnetic feedback) of the amplified error field.

Reimerdes, H.; Garofalo, A. M.; Strait, E. J.; Buttery, R. J.; Chu, M. S.; In, Y.; Jackson, G. L.; La Haye, R. J.; Lanctot, M. J.; Liu, Y. Q.; Okabayashi, M.; Park, J.-K.; Schaffer, M. J.; Solomon, W. M.

2009-11-01

86

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

87

High-speed sensory-motor fusion for robotic grasping  

NASA Astrophysics Data System (ADS)

In this paper a new high-speed vision device and its application to a grasp system is proposed, and we discuss a processing architecture for grasping based on visual and tactile feedback designed with real-time control in mind. First, we describe a high-speed vision chip that serves as a robotic eye that includes a general-purpose parallel processing array along with a photo-detector all on a single silicon chip. Next, we present a grasping algorithm based on real-time visual and tactile feedback, and a high-speed sensory-motor fusion system for robotic grasping. We then describe a grasping experiment using high-speed vision, and finally, based on these results, the effectiveness of high-speed sensory-motor fusion for robotic grasping is discussed.

Namiki, Akio; Komuro, Takashi; Ishikawa, Masatoshi

2002-11-01

88

Plasma Physics, Fusion Science, and California High School Science  

NASA Astrophysics Data System (ADS)

In order to further engage California HIgh School science teachers in plasma physics and fusion science, a collaboration was formed between LLNL's Fusion Energy Program and the University of California's Edward Teller Education Center (etec.ucdavis.edu). California's Science Content Standards for high school physics (www.cde.ca.gov/be/st/ss/scphysics.asp) were used to create a public lecture (education.llnl.gov/sos/) that covered "students are expected to achieve" physics topics relevant to astrophysical and fusion plasma research. In addition to the lecture, a two day workshop for the Edward Teller Education Symposium, September 24 - 25, 2004 (education.llnl.gov/symposium2004) was designed around plasma spectroscopy (education.llnl.gov/symposium2004/agenda_astro.html). Plasma spectroscopy was chosen as the "anchor" to the workshop given the breadth and depth of the field to both astrophysical and fusion plasma research. Workshop participation includes lectures, tours, spectroscopic measurements, and building a 'spectroscope' for use in the teachers' respective high school classrooms. Accomplishments will be reported and future plans will be presented that include development of a one to two week expanded workshop that includes plasma research methods and advanced science skills essential to guiding students to conduct research projects.

Correll, Donald

2004-11-01

89

Methodology for guaranteed and robust high level fusion performance: a literature study  

Microsoft Academic Search

A currently hot topic in Information Fusion research is fusion performance, including relevance, reliability, robustness, and trustworthiness, in particular for higher level fusion methods such as situation and impact refinement. Unless methodologies are found and generally applied which enable us to achieve and demonstrate trustworthiness, chances are slim that future commanders would be willing to trust high-level fusion systems. On

Johan Schubert; Per Svensson

2005-01-01

90

Fusion blanket high-temperature heat transfer  

SciTech Connect

Deep penetration of 14 MeV neutrons makes two-temperature region blankets feasible. A relatively low-temperature (approx. 300/sup 0/C) metallic structure is the vacuum/coolant pressure boundary, while the interior of the blanket, which is a simple packed bed of nonstructural material, operates at very high temperatures (>1000/sup 0/C). The water-cooled shell structure is thermally insulated from the steam-cooled interior. High-temperature steam can dramatically increase the efficiency of electric power generation, as well as produce hydrogen and oxygen-based synthetic fuels at high-efficiency.

Fillo, J.A.

1983-01-01

91

Staphylococcal protein A as a fusion partner directs secretion of the e1alpha and e1beta subunits of pea mitochondrial pyruvate dehydrogenase by Bacillus subtilis.  

PubMed

Staphylococcal protein A (SPA)-based vectors were constructed to direct secretion of the E1alpha and E1beta subunits of Pisum sativum mitochondrial pyruvate dehydrogenase from Bacillus subtilis. These proteins were not exported when the signal peptide from levansucrase (SacBSP) was fused to their N-termini. Both SacBSP-E1alpha and SacBSP-E1beta fusion proteins were insoluble in the cytoplasm. However, when the SPA open-reading frame was inserted between SacBSP and E1alpha or E1beta, corresponding fusion proteins were secreted from the cells. The first (E) IgG-binding domain of SPA was sufficient to direct low level secretion of both fusion proteins (SacBSP-E-E1alpha and SacBSP-E-E1beta). Adding the second (D) IgG-binding domain improved extracellular protein yields 3- to 4-fold over E alone, but was not as efficient as secretion of the full-length (EDABC) SPA-fusion proteins. All constructs were based on the pUB110-derived multicopy plasmid pWB705. Separate B. subtilis strains transformed with SacBSP-E-E1alpha-His(6) or SacBSP-E1beta were cocultivated in the presence of Ni-NTA agarose. The native pyruvate dehydrogenase alpha2beta2 structure was bound to the affinity matrix, demonstrating assembly after secretion. The use of SPA as a fusion partner during expression of heterologous proteins by B. subtilis provides the basis of a versatile system that can be used to study both secretion and protein:protein interactions. PMID:10686156

Moreno, J I; Miernyk, J A; Randall, D D

2000-03-01

92

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

93

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

94

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

95

Measuring pion beta decay with high-energy pion beams  

SciTech Connect

Improved measurements of the pion beta decay rate are possible with an intense high-energy pion beam. The rate for the decay [pi][sup +] [yields] [pi][sup 0]e[sup +]v[epsilon] is predicted by the Standard Model (SM) to be R([pi][sup +] [yields] [pi][sup 0]e[sup +]v[epsilon]) = 0.3999[plus minus]0.0005 s[sup [minus]1]. The best experimental number, obtained using in-flight decays, is R([pi][sup +] [yields] [pi][sup 0]e[sup +]v[epsilon]) = 0.394 [plus minus] 0.015 s[sup [minus]1]. A precise measurement would test the SM by testing the unitarity of the Cabibbo-Kobayashi-Maskawa matrix for which one analysis of the nuclear beta decay data has shown a 0.4% discrepancy. Several nuclear correction factors, needed for nuclear decay, are not present for pion beta decay, so that an experiment at the 0.2% level would be a significant one. Detailed study of possible designs will be needed, as well as extensive testing of components. The reduction of systematic errors to the 0.1% level can only be done over a period of years with a highly stable apparatus and beam. At a minimum, three years of occupancy of a beam line, with 800 hours per year, would be required.

McFarlane, W.K. (Superconducting Super Collider Lab., Dallas, TX (United States) Temple Univ., Philadelphia, PA (United States)); Hoffman, C.M. (Los Alamos National Lab., NM (United States))

1993-01-01

96

Measuring pion beta decay with high-energy pion beams  

SciTech Connect

Improved measurements of the pion beta decay rate are possible with an intense high-energy pion beam. The rate for the decay {pi}{sup +} {yields} {pi}{sup 0}e{sup +}v{epsilon} is predicted by the Standard Model (SM) to be R({pi}{sup +} {yields} {pi}{sup 0}e{sup +}v{epsilon}) = 0.3999{plus_minus}0.0005 s{sup {minus}1}. The best experimental number, obtained using in-flight decays, is R({pi}{sup +} {yields} {pi}{sup 0}e{sup +}v{epsilon}) = 0.394 {plus_minus} 0.015 s{sup {minus}1}. A precise measurement would test the SM by testing the unitarity of the Cabibbo-Kobayashi-Maskawa matrix for which one analysis of the nuclear beta decay data has shown a 0.4% discrepancy. Several nuclear correction factors, needed for nuclear decay, are not present for pion beta decay, so that an experiment at the 0.2% level would be a significant one. Detailed study of possible designs will be needed, as well as extensive testing of components. The reduction of systematic errors to the 0.1% level can only be done over a period of years with a highly stable apparatus and beam. At a minimum, three years of occupancy of a beam line, with 800 hours per year, would be required.

McFarlane, W.K. [Superconducting Super Collider Lab., Dallas, TX (United States)]|[Temple Univ., Philadelphia, PA (United States); Hoffman, C.M. [Los Alamos National Lab., NM (United States)

1993-02-01

97

Fusion blankets for high-efficiency power cycles  

NASA Astrophysics Data System (ADS)

The efficiencies of blankets for fusion reactors are usually in the range of 30 to 40%, limited by the operating temperatures (500 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 led to a reference blanket design consisting of a water cooled stainless steel shell around a BeO, ZrO2 interior (cooled by Ar) utilizing Li2O for tritium breeding. In this design, 60% of the fusion energy is deposited in the high temperature interior. The maximum Ar temperature is 2230 C leading to an overall efficiency estimate of 55 to 60% for this reference case.

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

1980-10-01

98

High temperature superconducting current leads for fusion magnet systems  

NASA Astrophysics Data System (ADS)

Superconducting magnets for fusion applications typically have very high operating currents. These currents are transmitted from the room temperature power supplies to the low temperature superconducting coils by way of helium-vapor-cooled current leads. Because of the high current magnitude and the resistive characteristics associated with the normal metallic lead conductors, a substantial amount of power is dissipated in the lead. To maintain a stable operation, a high rate of helium vapor flow, generated by the boil-off of liquid helium, is required to cool the lead conductors. This helium boil-off substantially increases both the installation capacity and the operating cost of the helium refrigerator/liquefier. The boil-off of liquid helium can be significantly reduced by employing ceramic high temperature superconductors, such as Y-Ba-Cu-O, in the low temperature part of the lead conductor structure. This concept utilizes the superconducting, as well as the low thermal conductivity properties of the superconductor materials in eliminating power dissipation in part of the current lead and in inhibiting heat conduction into the liquid helium pool, resulting in reduced helium boil-off. This design concept has been conclusively demonstrated by a 2-kA current lead test model using Y-Ba-Cu-O (123) material which, although not optimized in design, has significantly reduced the rate of helium boil-off in comparison to optimized conventional leads. There appear to be no major technological barriers for scaling up this design to higher current levels for applications in fusion magnet systems or in fusion related testing activities. The theoretical basis of the current lead concept, as well as the important design and technology issues are addressed. The potential cost saving derived from employing these leads in fusion magnets is also discussed. In addition, a design concept for a 10-kA lead is presented.

Wu, J. L.; Dederer, J. T.; Singh, S. K.; Hull, J. R.

99

Design issues for a laboratory high gain fusion facility  

SciTech Connect

In an inertial fusion laboratory high gain facility, experiments will be carried out with up to 1000 MJ of thermonuclear yield. The experiment area of such a facility will include many systems and structures that will have to operate successfully in the difficult environment created by the sudden large energy release. This paper estimates many of the nuclear effects that will occur, discusses the implied design issues and suggests possible solutions so that a useful experimental facility can be built. 4 figs.

Hogan, W.J.

1987-11-02

100

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

101

Access to Wall Stabilized High Beta Operation in NSTX^1  

NASA Astrophysics Data System (ADS)

This study's goal is the identification of the set of equilibrium trajectories that will provide access to NSTX conceptual design target parameters of ?N ~= 8, ?T ~= 40%, starting from existing experimental equilibrium reconstructions. Previous numerical studies have identified possible target configurations with ?N ~= 8.2, li ~= 0.35, pressure peakedness P(0)/ ? F_p=1.7, and studied their robustness to variation of the equilibrium profile shaping^2,3. In high-li (l_i> 0.8) configurations wall stabilization is less effective due to core localization of the modes. At low-li (li ~= 0.5), and low ?N (?N <= 4.0), passive stabilization is also inefficient since the perturbed radial field from the mostly current driven modes maximizes at small major radius which is far from the passive conducting structure. Access to high ?N operation could be achieved at medium-li (0.6 - 0.8) to avoid the current driven modes and allow for effective passive wall stabilization. Since high Fp degrades stability, P profile control will also be needed on NSTX. ^1USDOE Contracts: DE-FG02-89ER53297; DE-AC02-76CH03073. ^2J. Menard, et al., Nucl. Fusion, 37, 595 (1997).^3F. Paoletti, et al., Sub. to Nucl. Fusion, (2001).

Paoletti, F.; Sabbagh, S. A.; Bialek, J.; Gates, D.; Bell, R.; Leblanc, B.; Kaye, S.; Manickam, J.; Menard, J.; Glasser, A.; Turnbull, A.

2001-10-01

102

High temperature coatings based on beta-NiAl  

NASA Astrophysics Data System (ADS)

Ni-based superalloys have been the workhorse materials in the high temperature alloy industry. Further increases in operating temperatures of these alloys have been limited due to low melting temperatures of constituent phases. A new alloy system has been proposed based on the Mo-Ni-Al system, which appears to be a promising alternative alloy. However, the intrinsic oxidation resistance of these alloys is relatively poor compared to current Ni-based superalloys. A two-step coating process based on electroplating and pack cementation was used to synthesize beta-NiAl coatings on top of the Mo-Ni-Al alloys. These coatings were seen to be stable when exposed to expected operating conditions, and substantially improved the oxidation resistance of the Mo-Ni-Al alloys. Grain size of beta-NiAl has been shown to be important during oxidation. Platinum group metals and Hf have been identified as effective alloying additions. However, less expensive additions need to be identified. Additions of 2 nd phase TiB2 particles were found to decrease the initial grain size of beta-NiAl, and limit grain growth after long term exposure at 1300°C.

Severs, Kevin Richard

103

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

104

High-Yield Magnetized Liner Fusion Explosions and Blast Mitigation  

NASA Astrophysics Data System (ADS)

Cylindrical liner implosions with preheated and magnetized deuterium-tritium (DT) are predicted to reach fusion conditions on present pulsed power machines [S.A. Slutz et al Phys. Plasmas 17, 056303 (2010)]. We present simulations indicating that high yields (1-10 GJ) and gains (100-1000) may be possible at currents of about 60-70 MA if a cryogenic layer of solid DT is provided on the inside surface of the metal liner. A hot spot is formed from the central preheated magnetized low-density gas and a burn wave propagates radially into the surrounding cold dense fuel. These yields and gains are more than adequate for inertial fusion energy. However, the pulsed-power driver must be protected from the blast of these high-yield explosions. Numerical simulations are presented which show that the blast can be deflected and the fusion neutrons absorbed by a blanket that partially surrounds the liner. Thus a modest length transmission line can be used to deliver power to the liner.

Slutz, Stephen; Vesey, Roger; Cuneo, Michael

2011-11-01

105

High levels of circulating beta-amyloid peptide do not cause cerebral beta-amyloidosis in transgenic mice.  

PubMed Central

We have established transgenic mice that constitutively overproduce the signal sequence and the 99-amino-acid carboxyl-terminal region of the human beta-amyloid precursor protein. The transgenic mice strongly expressed the transgene in multiple tissues under the control of a cytomegalovirus enhancer/chick beta-actin promoter. There were exceptionally high levels of beta-amyloid peptides in the plasma (approximately 17 times or more compared with the human plasma level). Although some transgenic mice from one founder line developed amyloidosis in the intestine, no neuropathology was found in transgenic mice up to age 29 months. Given the absence of cerebral beta-amyloidosis despite extremely high levels of circulating beta-amyloid peptides in the transgenic mice, the results suggest that local cerebral metabolism of beta-amyloid precursor protein may play a predominant role in cerebral beta-amyloidosis in transgenic mice. Such transgenic mice may be useful for the investigation of the etiology of the disease and for the establishment of therapeutic strategies. Images Figure 1 Figure 2 Figure 3 Figure 4

Fukuchi, K.; Ho, L.; Younkin, S. G.; Kunkel, D. D.; Ogburn, C. E.; LeBoeuf, R. C.; Furlong, C. E.; Deeb, S. S.; Nochlin, D.; Wegiel, J.; Wisniewski, H. M.; Martin, G. M.

1996-01-01

106

Developmental and environmental regulation of a phenylalanine ammonia-lyase-beta-glucuronidase gene fusion in transgenic tobacco plants.  

PubMed Central

A 1.1-kilobase promoter fragment of the bean (Phaseolus vulgaris L.) phenylalanine ammonia-lyase (EC 4.3.1.5) gene PAL2 was translationally fused to the beta-glucuronidase reporter gene and transferred to tobacco by Agrobacterium tumefaciens-mediated leaf disk transformation. The distribution of beta-glucuronidase activity in these transgenic plants is very similar to that of endogenous PAL2 transcripts in bean, with very high levels in petals; marked accumulation in anthers, stigmas, roots, and shoots; and low levels in sepals, ovaries, and leaves. Histochemical analysis of the spatial pattern of beta-glucuronidase activity showed that the PAL2 promoter is highly active in the shoot apical meristem, the zone of cell proliferation immediately adjacent to the root apical meristem, and in the early stages of vascular development at the inception of xylem differentiation. Wounding and light evoke specific changes in the spatial pattern of beta-glucuronidase activity in stems, including induction in the epidermis. These data indicate that the PAL2 promoter transduces a complex set of developmental and environmental cues into an integrated spatial and temporal program of gene expression to regulate the synthesis of a diverse array of phenylpropanoid natural products. Images

Liang, X W; Dron, M; Schmid, J; Dixon, R A; Lamb, C J

1989-01-01

107

High-performance inertial confinement fusion target implosions on OMEGA  

NASA Astrophysics Data System (ADS)

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-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.; Séguin, F. H.; Seka, W.; Short, R. W.; Shvarts, D.; Skupsky, S.; Soures, J. M.; Stoeckl, C.; Theobald, W.; Yaakobi, B.

2011-05-01

108

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

109

High-Beta, Anisotropic Plasma Confinement in an Axially Symmetric Gas Dynamic Trap  

NASA Astrophysics Data System (ADS)

In the Gas Dynamic Trap (GDT) axially symmetric magnetic mirror, measurements have confirmed that on-axis transverse beta approximately equal to 40% is achieved in the fast ion turning points [A.A. Ivanov et al., Phys. Rev. Lett. 90, 105002 (2003)]. In GDT, oblique injection of 4 MW of 17 keV deuterium neutral beams into a warm (<100 eV) target plasma produces a population of anisotropic fast deuterons, which oscillate back and forth between the turning points near the end mirrors ("sloshing" ions). Since the fast ions spend a large fraction of a bounce time near the turning points, their density and temperature are strongly peaked (10^19 m-3, 10 keV) in these regions. The measured beta is close to the theoretical prediction of the MHD stability threshold for ballooning modes in this mirror trap. GDT is stable against interchange modes due to average good curvature along a magnetic field line. This is provided by sufficiently high density of the target plasma in the axially symmetric end cells, where the magnetic field lines contribute substantial good curvature. The collisional target plasma is confined in the mirror as if it were an ideal gas in a container with pinhole leaks. Ions are lost out of the mirrors with the rate of an ion-acoustic speed. At the same time, the fast ion angular distribution remains quite narrow and centered on the initial value of the pitch angle. Neither enhanced transverse losses of the plasma nor anomalies in the fast ion scattering and slowing down were observed in experiments. Measured D-D neutron flux is peaked in the turning points; these are the same regions that house the testing zones in the projected GDT-based neutron source. The measured beta and axial profile of the D-D neutron flux are similar to that required for a 14 MeV neutron source for fusion materials testing.

Lizunov, A. A.

2003-10-01

110

High-Speed Moving Target Recognition Technology Based on Multisensor Data Fusion  

Microsoft Academic Search

Multi-sensor data fusion theory and methods have been widely applied to many fields. Multi-sensor data fusion and information redundancy technology are adopted to achieve target characters synthetically judgment.. The basic concept of multi-sensor data fusion is given. Identifying characteristics of high-speed moving targets and key technical problems of multi-sensor fusion are discussed. Recognition research of moving targets is given through

Guo Hualing; Deng Jiahao; Cai Kerong

2010-01-01

111

Energy scaling of inertial confinement fusion targets for ignition and high gain  

Microsoft Academic Search

The dependence of the ignition threshold on the velocity vimp and compressibility of an imploding fuel mass is central to establishing the driver requirements and implosion strategy for inertial confinement fusion (ICF). Using a series of LASNEX calculations, it is found that keimp varies as nu imp- alpha beta a, where keimp is the kinetic energy in the imploding fuel

W. K. Levedahl; J. D. Lindl

1997-01-01

112

Fusion neutron test facility requirements for interactive effects in structural and high-heat-flux components  

Microsoft Academic Search

A relevant design data base is needed for structural components in near-term and commercial fusion devices. A high-flux, high-fluence fusion neutron test facility is required for testing the failure mechanisms and lifetime-limiting features for first wall, blanket, and high-heat-flux components. We describe here the key aspects of the fusion environment which influence the response of structural and high-heat-flux components. In

N. M. Ghoniem; J. B. Whitley

1989-01-01

113

Highly enantioselective reduction of beta,beta-disubstituted aromatic nitroalkenes catalyzed by Clostridium sporogenes.  

PubMed

This is the first report of the use of Clostridium sporogenes extracts for enantioselective reduction of CC double bonds of beta,beta-disubstituted (1) and alpha,beta-disubstituted nitroalkenes (3). Crude enzyme preparations reduced aryl derivatives 1a-e and 1h, in 35-86% yield with > or =97% ee. Reduction of (E)- and (Z)-isomers of 1c gave the same enantiomer of 2c (> or =99% ee). In contrast, alpha,beta-disubstituted nitroalkene 3a was a poor substrate, yielding (S)- 4a in low yield (10-20%), and the ee (30-70% ee) depended on NADH concentration. An efficient synthesis of a library of nitroalkenes 1 is described. PMID:18452336

Fryszkowska, Anna; Fisher, Karl; Gardiner, John M; Stephens, Gill M

2008-06-01

114

On ontologies for high-level information fusion  

Microsoft Academic Search

It is now commonly accepted that on- tologies will facilitate the information fusion activity. However, it is not clear what should be the exact form of this facilitation process. It is relatively well under- stood what information fusion is; the question of what ontologies are has also been extensively mplored. How- ever, it is not clear what ontology-based information fusion

Chris Nowak

2003-01-01

115

Spectrin alpha II and beta II isoforms interact with high affinity at the tetramerization site.  

PubMed Central

Spectrin tetramers form by the interaction of two alpha-beta dimers through two helices close to the C-terminus of a beta subunit and a single helix at the N-terminus of an alpha subunit. Early work on spectrin from solid tissues (typified by alphaII and betaII polypeptides) indicated that it forms a more stable tetramer than erythroid spectrin (alphaI-betaI). In the present study, we have probed the molecular basis of this phenomenon. We have quantified the interactions of N-terminal regions of two human alpha polypeptides (alphaI and alphaII) with the C-terminal regions of three beta isoforms (betaISigma1, betaIISigma1 and betaIISigma2). alphaII binds either betaII form with a much higher affinity than alphaI binds betaISigma1 ( K (d) values of 5-9 nM and 840 nM respectively at 25 degrees C). betaIISigma1 and betaIISigma2 are splice variants with different C-terminal extensions outside the tetramerization site: these extensions affect the rate rather than the affinity of alpha subunit interaction. alphaII spectrin interacts with each beta subunit with higher affinity than alphaI, and the betaII polypeptides have higher affinities for both alpha chains than betaISigma1. The first full repeat of the alpha subunit has a major role in determining affinity. Enthalpy changes in the alphaII-betaIISigma2 interaction are large, but the entropy change is comparatively small. The interaction is substantially reduced, but not eliminated, by concentrated salt solutions. The high affinity and slow overall kinetics of association and dissociation of alphaII-betaII spectrin may suit it well to a role in strengthening cell junctions and providing stable anchor points for transmembrane proteins at points specified by cell-adhesion molecules.

Bignone, Paola A; Baines, Anthony J

2003-01-01

116

Ellipticity criterion for flowing two-fluid high beta equilibria  

SciTech Connect

An improved formalism for flowing two-fluid equilibria with nonuniform density is developed in the absence of dissipation. The system for axisymmetric equilibria can be expressed using second-order partial differential equations for the stream functions of the generalized vorticities of the electron and ion fluids. It is found that the equilibrium equations are elliptic when the poloidal ion flow speed is less than the sound speed. This property differs markedly from the single-fluid model. The two-fluid result is compared with that for the single-fluid model. It is important to determine if well-confined flowing plasmas satisfy this ellipiticity criterion throughout the plasma. Measurements of plasma poloidal flow velocities in high beta plasmas are therefore encouraged. (C) 2004 American Institute of Physics.

Ishida, A. [Niigata University, Niigata, Japan; Peng, Yueng Kay Martin [ORNL

2004-01-01

117

Resistive wall stabilized operation in rotating high beta NSTX plasmas  

NASA Astrophysics Data System (ADS)

The National Spherical Torus Experiment (NSTX) has demonstrated the advantages of low aspect ratio geometry in accessing high toroidal and normalized plasma beta, \\beta _t \\equiv 2\\mu_{0}\\langle p\\rangle /B_{0}^{2} and ?N ? 108lang?trang aB0/Ip. Experiments have reached ?t = 39% and ?N = 7.2 through boundary and profile optimization. High ?N plasmas can exceed the ideal no-wall stability limit, ?Nno-wall, for periods much greater than the wall eddy current decay time. Resistive wall mode (RWM) physics is studied to understand mode stabilization in these plasmas. The toroidal mode spectrum of unstable RWMs has been measured with mode number n up to 3. The critical rotation frequency of Bondeson-Chu, ?crit = ?A/(4q2), describes well the RWM stability of NSTX plasmas when applied over the entire rotation profile and in conjunction with the ideal stability criterion. Rotation damping and global rotation collapse observed in plasmas exceeding ?Nno-wall differs from the damping observed during tearing mode activity and can be described qualitatively by drag due to neoclassical toroidal viscosity in the helically perturbed field of an ideal displacement. Resonant field amplification of an applied n = 1 field perturbation has been measured and increases with increasing ?N. Equilibria are reconstructed including measured ion and electron pressure, toroidal rotation and flux isotherm constraint in plasmas with core rotation ?phi/?A up to 0.48. Peak pressure shifts of 18% of the minor radius from the magnetic axis have been reconstructed.

Sabbagh, S. A.; Sontag, A. C.; Bialek, J. M.; Gates, D. A.; Glasser, A. H.; Menard, J. E.; Zhu, W.; Bell, M. G.; Bell, R. E.; Bondeson, A.; Bush, C. E.; Callen, J. D.; Chu, M. S.; Hegna, C. C.; Kaye, S. M.; Lao, L. L.; LeBlanc, B. P.; Liu, Y. Q.; Maingi, R.; Mueller, D.; Shaing, K. C.; Stutman, D.; Tritz, K.; Zhang, C.

2006-05-01

118

Observation of the hot electron interchange instability in a high beta dipolar confined plasma  

NASA Astrophysics Data System (ADS)

In this thesis the first study of the high beta, hot electron interchange (HEI) instability in a laboratory, dipolar confined plasma is presented. The Levitated Dipole Experiment (LDX) is a new research facility that explores the confinement and stability of plasma created within the dipole field produced by a strong superconducting magnet. In initial experiments long-pulse, quasi-steady state microwave discharges lasting more than 10 sec have been produced with equilibria having peak beta values of 20%. Creation of high-pressure, high beta plasma is possible only when intense HEI instabilities are stabilized by sufficiently high background plasma density. LDX plasma exist within one of three regimes characterized by its response to heating and fueling. The observed HEI instability depends on the regime and can take one of three forms: as quasiperiodic bursts during the low density, low beta plasma regime, as local high beta relaxation events in the high beta plasma regime, and as global, intense energy relaxation bursts, both in the high beta and afterglow plasma regimes. Measurements of the HEI instability are made using high-impedance, floating potential probes and fast Mirnov coils. Analysis of these signals reveals the extent of the transport during high beta plasmas. During intense high beta HEI instabilities, fluctuations at the edge significantly exceed the magnitude of the equilibrium field generated by the high beta electrons and energetic electron confinement ends in under 100 musec. For heated plasmas, one of the consequences of the observed high beta transport is the presence of hysteresis in the neutral gas fueling required to stabilize and maintain the high beta plasma. Finally, a nonlinear, self-consistent numerical simulation of the growth and saturation of the HEI instability has been adapted for LDX and compared to experimental observations.

Ortiz, Eugenio Enrique

119

Image fusion based on principal component analysis and high-pass filter  

Microsoft Academic Search

Several commercial earth observation satellites carry dual-resolution sensors, which provide high spatial resolution panchromatic image and low spatial resolution multi-spectral image. Image fusion techniques are therefore useful for integrating a high spectral resolution image with a high spatial resolution image, to produce a fused image with high spectral and spatial resolutions. Some image fusion methods such as IHS, PC and

Mohamed R. Metwalli; Ayman H. Nasr; Osama S. Farag Allah; S. El-Rabaie

2009-01-01

120

High resolution imaging systems for inertial confinement fusion experiments  

NASA Astrophysics Data System (ADS)

The path to successful inertial confinement fusion (ICF) requires to observe and control the micro balloon deformations. This will be achieved using X-ray microscope among other diagnostics. A high resolution, high energy X-ray microscope involving state-of-the-art toroidal mirrors and multilayer coatings is described. Years of experiments and experience have led to a small-scale X-ray plasma imager that proves the feasibility of all the features required for a LMJ diagnostic: spatial resolution of 5?m, broad bandwidth, millimetric field of view (FOV). Using the feedback given by this diagnostic, a prototype for the Laser MegaJoule (LMJ) experiments has been designed. The experimental results of the first diagnostic and the concepts of the second are discussed.

Dennetiere, D.; Audebert, P.; Bahr, R.; Bole, S.; Bourgade, J. L.; Brannon, B.; Girard, F.; Pien, G.; Troussel, Ph.

2012-10-01

121

High-level information fusion and mission planning in highly anisotropic threat spaces  

Microsoft Academic Search

This paper presents a command and control (C2) agents approach to supporting tactical decision making by operational commanders. The work addresses two C2 issues: the use of networked information sharing and high-level information fusion to allow for the visualisation of highly anisotropic threat spaces, and associated route planning for a variety of effects based tasks taking into account a commanderpsilas

Mark Witkowski; Gareth White; Panos Louvieris; Gökçe Görbil; Erol Gelenbe; Lorraine Dodd

2008-01-01

122

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. J. Med. Virol. 86:1296-1306, 2014. © 2014 Wiley Periodicals, Inc. PMID:24760738

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

2014-08-01

123

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

124

Transport in high normalized beta discharges on ASDEX Upgrade  

NASA Astrophysics Data System (ADS)

An advanced high confinement mode scenario with normalized beta (?N) up to 3.5 in stationary conditions (up to 20 energy confinement times) and ?N = 3.8 transiently, has been obtained in ASDEX Upgrade. For transport analysis of high ?N discharges, two types of simulations have been performed with the automated system for transport analysis code. One is the simulation of the current density profile with experimental data assuming neoclassical electrical conductivity. The other is the simulation of the energy transport and the current density profile using the Weiland transport model (ion temperature gradient and trapped electron mode limit the temperature gradient length). The comparison of the simulations of the q-profiles and temperature profiles with the experimental profiles shows good agreement and demonstrates that for this plasmas regime the temperature profiles are stiff (no internal transport barrier) as in conventional H-mode discharges. The contribution of the Ohmic, bootstrap and neutral beam driven current to the total current density profiles is calculated. The sum of the non-inductively driven plasma current is in the range 50-57% of the total plasma current. Simulations with the Weiland model are performed to investigate the influence of neoclassical tearing modes, which limit confinement and achievable ?N in this scenario, by comparing with the measured kinetic data. In addition, the high ?N discharges are compared to the improved H-mode discharges in ASDEX Upgrade with respect to the profile stiffness, MHD activity and experimental conditions.

Na, Yong-Su; Sips, A. C. C.; Gruber, O.; Hobirk, J.; Pereverzev, G.; ASDEX Upgrade Team

2002-07-01

125

Effects of high density lipoprotein containing high or low beta-carotene concentrations on progesterone production and beta-carotene uptake and depletion by bovine luteal cells.  

PubMed

Luteal cells were isolated from mid-luteal heifer ovaries by collagenase digestion. Cells were cultured with DMEM/Ham's F12 medium in serum pre-treated plastic culture dishes for periods of up to 11 days. As beta-carotene is almost completely insoluble in all polar solvents, it was added to cultures in either dimethyl sulphoxide (DMSO), tetrahydrofuran (THF) or as high-density lipoprotein (HDL) containing high or low beta-carotene concentrations. Medium was replaced after 24 h, thereafter medium was changed every 48 h. Treatment of cells with DMSO alone or with beta-carotene (5 micromol/l) in DMSO both resulted in significant (P<0.01) stimulation of progesterone production. beta-Carotene (5 micromol/l) in THF did not alter progesterone production but 50 micromol/l beta-carotene in THF resulted in significant inhibition (P<0.02) of progesterone production on days 3 and 7. Cultures were also supplemented with bovine HDL preparations containing equal concentrations of cholesterol (25 microg/ml) but high or low beta-carotene (12.4 or 0.44 microg/mg of cholesterol). Both HDL preparations significantly stimulated progesterone production (P<0. 001) but the high beta-carotene HDL was significantly (P<0.02) more effective than the low beta-carotene HDL. However, when given together with bovine luteinizing hormone (bLH) or dibutyryl cAMP (dbcAMP), the high beta-carotene HDL stimulated progesterone production less than did the low HDL (P<0.01). Uptake and depletion of beta-carotene by luteal cells were also examined in culture. beta-Carotene supplementation increased luteal cell beta-carotene from an initial level of 373 ng per 10(6) cells to 2030 ng per 10(6) cells by day 6. In contrast, the levels in control cells decreased to 14% of starting values during the same period. Cells treated with HDL containing high beta-carotene on day 1 or days 1 and 3 were then incubated with or without bLH or dbcAMP for a further 2 days to investigate the effect of bLH and dbcAMP on depletion of beta-carotene by luteal cells. beta-Carotene depletion in the luteal cells was significantly higher (P<0.05) in LH- and dbcAMP-treated cells than in the control cells in both groups. These results indicate that the use of solvents such as DMSO or THF may have undesirable effects due to alteration of cell membrane permeability. Supplementation with bLH or dbcAMP may increase the metabolism of beta-carotene in luteal cells. bLH or dbcAMP together with high beta-carotene HDL may, when combined with the effect of increased beta-carotene metabolism, give less stimulation than with low beta-carotene HDL. PMID:10924828

Arikan, S; Rodway, R G

2000-09-01

126

Equilibrium and global MHD stability study of KSTAR high beta plasmas under passive and active mode control  

NASA Astrophysics Data System (ADS)

The Korea Superconducting Tokamak Advanced Research, KSTAR, is designed to operate a steady-state, high beta plasma while retaining global magnetohydrodynamic (MHD) stability to establish the scientific and technological basis of an economically attractive fusion reactor. An equilibrium model is established for stability analysis of KSTAR. Reconstructions were performed for the experimental start-up scenario and experimental first plasma operation using the EFIT code. The VALEN code was used to determine the vacuum vessel current distribution. Theoretical high beta equilibria spanning the expected operational range are computed for various profiles including generic L-mode and DIII-D experimental H-mode pressure profiles. Ideal MHD stability calculations of toroidal mode number of unity using the DCON code shows a factor of 2 improvement in the wall-stabilized plasma beta limit at moderate to low plasma internal inductance. The planned stabilization system in KSTAR comprises passive stabilizing plates and actively cooled in-vessel control coils (IVCCs) designed for non-axisymmetric field error correction and stabilization of slow timescale MHD modes including resistive wall modes (RWMs). VALEN analysis using standard proportional gain shows that active stabilization near the ideal wall limit can be reached with feedback using the midplane segment of the IVCC. The RMS power required for control using both white noise and noise taken from NSTX active stabilization experiments is computed for beta near the ideal wall limit. Advanced state-space control algorithms yield a factor of 2 power reduction assuming white noise while remaining robust with respect to variations in plasma beta.

Katsuro-Hopkins, O.; Sabbagh, S. A.; Bialek, J. M.; Park, H. K.; Bak, J. G.; Chung, J.; Hahn, S. H.; Kim, J. Y.; Kwon, M.; Lee, S. G.; Yoon, S. W.; You, K.-I.; Glasser, A. H.; Lao, L. L.

2010-02-01

127

High convergence, indirect drive inertial confinement fusion experiments at Nova  

SciTech Connect

High convergence, indirect drive implosion experiments have been done at the Nova Laser Facility. The targets were deuterium and deuterium/tritium filled, glass microballoons driven symmetrically by x rays produced in a surrounding uranium hohlraum. Implosions achieved convergence ratios of 24:1 with fuel densities of 19 g/cm{sup 3}; this is equivalent to the range required for the hot spot of ignition scale capsules. The implosions used a shaped drive and were well characterized by a variety of laser and target measurements. The primary measurement was the fuel density using the secondary neutron technique (neutrons from the reaction {sup 2}H({sup 3}H,n){sup 4}He in initially pure deuterium fuel). Laser measurements include power, energy and pointing. Simultaneous measurement of neutron yield, fusion reaction rate, and x-ray images provide additional information about the implosion process. Computer models are in good agreement with measured results.

Lerche, R.A.; Cable, M.D.; Hatchett, S.P. [and others

1995-06-02

128

High-Density Carbon Ablators for Inertial Confinement Fusion  

NASA Astrophysics Data System (ADS)

A series of experiments on the Omega laser have been preformed to measure high-density carbon (HDC) ablator performance for indirect drive inertial confinement fusion (ICF). The Omega laser was used to generate shaped laser pulses with varying powers during the first nanosecond of the drive to investigate drive pressures between 1.7 Mb and 7.5 Mb. The total neutron yield, ion temperature, neutron bang time and x-ray bang time were measured and compared to simulations. Experiments using HDC ablators are planned for the National Ignition Facility and will be discussed. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and supported by LDRD-11-ERD-075.

Ross, James; Amendt, Peter; Callahan, Debbie; Prisbrey, Shon; Suter, Larry; Glenzer, Siegfried

2012-10-01

129

Advantages of High Tolerance Measurements in Fusion Environments Applying Photogrammetry  

SciTech Connect

Photogrammetry, a state-of-the-art technique of metrology employing digital photographs as the vehicle for measurement, has been investigated in the fusion environment. Benefits of this high tolerance methodology include relatively easy deployment for multiple point measurements and deformation/distortion studies. Depending on the equipment used, photogrammetric systems can reach tolerances of 25 microns (0.001 in) to 100 microns (0.004 in) on a 3-meter object. During the fabrication and assembly of the National Compact Stellarator Experiment (NCSX) the primary measurement systems deployed were CAD coordinate-based computer metrology equipment and supporting algorithms such as both interferometer-aided (IFM) and absolute distance measurementbased (ADM) laser trackers, as well as portable Coordinate Measurement Machine (CMM) arms. Photogrammetry was employed at NCSX as a quick and easy tool to monitor coil distortions incurred during welding operations of the machine assembly process and as a way to reduce assembly downtime for metrology processes.

T. Dodson, R. Ellis, C. Priniski, S. Raftopoulos, D. Stevens, M. Viola

2009-02-04

130

Indirectly driven, high convergence inertial confinement fusion implosions  

SciTech Connect

A series of high convergence indirectly driven implosions has been done with the Nova Laser Fusion facility. These implosions were well characterized by a variety of measurements; computer models are in good agreement. The imploded fuel areal density was measured using a technique based on secondary neutron spectroscopy. At capsule convergences of 24:1, comparable to what is required for the hot spot of ignition scale capsules, these capsules achieved fuel densities of 19 g/cm[sup 3]. Independent measurements of density, burn duration, and ion temperature gave [ital n][tau][theta]=1.7[plus minus]0.9[times]10[sup 14] keV s/cm[sup 3].

Cable, M.D.; Hatchett, S.P.; Caird, J.A.; Kilkenny, J.D.; Kornblum, H.N.; Lane, S.M.; Laumann, C.; Lerche, R.A.; Murphy, T.J.; Murray, J.; Nelson, M.B.; Phillion, D.W.; Powell, H.; Ress, D.B. (Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551 (United States))

1994-10-24

131

Fusion with highly spin polarized HD and D2  

NASA Astrophysics Data System (ADS)

The experimental efforts over the past 5 years have been aimed at carrying out inertial confinement fusion (ICF) shots with spin-polarized D fuel. The authors successfully prepared polarized D in HD, and solved the problems of loading target shells with their carefully prepared isotopic mixtures, polarizing them so that the D polarization remains metastably frozen-in for about half a day, and carrying out the various cold transfer requirements at Syracuse, where the target is prepared, and at Rochester, where the cold target is inserted into the OMEGA fusion chamber. A principal concern during this past year was overcoming difficulties encountered in maintaining the integrity of the fragile cold target during the multitude of cold-transfers required for the experiment. These difficulties arose from insufficient rigidity of the cold transfer systems, which were constrained to be of small diameter by the narrow central access bore of the dilution refrigerator, and were exacerbated by the multitude of required target shell manipulations between different environments, each with different coupling geometry, including target shell permeation, polarization, storage, transport, retrieval and insertion into OMEGA. The authors did solve all of these problems, and were able to position a cold, high density but unpolarized target with required precision in OMEGA. Upon shooting the accurately positioned unpolarized high density cold target, no neutron yield was observed. Inspection inside the OMEGA tank after the shot indicated the absence of neutron yield was due to mal-timing or insufficient retraction rate of OMEGA's fast shroud mechanism, resulting in interception of at least 20 of the 24 laser beams by the faulty shroud. In spite of this, all elements of the complex experiment the authors originally undertook have been successfully demonstrated, and the cold retrieval concepts and methods they developed are being utilized on the ICF upgrades at Rochester and at Livermore.

Honig, A.; Letzring, S.; Skupsky, S.

1993-12-01

132

High-level fusion: Issues in developing a formal theory  

Microsoft Academic Search

Network-centric operations demand an increasingly sophisticated level of interoperation and information fusion for an escalating number and throughput of sensors and human processes. The resulting complexity of the systems being developed to face this environment render lower level fusion techniques alone simply insufficient to ensure interoperability, as they fail to consider subtle, but critical, aspects inherent in knowledge interchange. A

Paulo C. G. Costa; Kuo-Chu Chang; Kathryn Laskey; Tod Levitt; Wei Sun

2010-01-01

133

Observation of high-energy deuterium–tritium fusion gamma rays using gas Cherenkov detectors  

Microsoft Academic Search

As fusion ignition conditions are approached using the National Ignition Facility (NIF), independent high-bandwidth gamma-ray fusion-burn measurements become essential complements to neutron-based methods. Time resolution ?20ps (10–30GHz), energy discrimination, and significant stand off distance may be needed for credible burn history measurements.The 16.75MeV gamma rays that accompany deuterium–tritium (d+t) fusion provide a high-bandwidth alternative to 14MeV fusion neutrons for d+t

J. M. Mack; R. R. Berggren; S. E. Caldwell; S. C. Evans; J. R. Faulkner; R. A. Lerche; J. A. Oertel; C. S. Young

2003-01-01

134

Observation of high-energy deuterium-tritium fusion gamma rays using gas Cherenkov detectors  

Microsoft Academic Search

As fusion ignition conditions are approached using the National Ignition Facility (NIF), independent high-bandwidth gamma-ray fusion-burn measurements become essential complements to neutron-based methods. Time resolution ~20ps (10-30GHz), energy discrimination, and significant stand off distance may be needed for credible burn history measurements. The 16.75MeV gamma rays that accompany deuterium-tritium (d+t) fusion provide a high-bandwidth alternative to 14MeV fusion neutrons for

J. M. Mack; R. R. Berggren; S. E. Caldwell; S. C. Evans; J. R. Faulkner; R. A. Lerche; J. A. Oertel; C. S. Young

2003-01-01

135

Expression of the extracellular domain of the human immunodeficiency virus type 1 envelope protein and its fusion with beta-galactosidase in Saccharomyces cerevisiae.  

PubMed

Two envelope glycoprotein gene fragments were cloned from the proviral genome of the HXB2 isolate of human immunodeficiency virus (HIV). For the production of the two domains of the envelope gene product these cloned gene fragments were inserted into an Escherichia coli-yeast inducible shuttle vector fused to the galactokinase (GAL1) promoter. Cell extracts from strains of Saccharomyces cerevisiae harboring these two vectors (pYENV1 and pYENV2) were found to contain a specific protein with a size of 50 kDa when induced by galactose, while the protein could not be detected in extracts from control cells containing only the E. coli-yeast vector in the presence of galactose. Furthermore, another expression plasmid coding for fusion proteins from the majority of the external envelope glycoprotein (gp120) moiety and a large part of the beta-galactosidase was constructed. Antibodies from HIV type 1-positive sera could react with recombinant fusion polypeptides. Transformants could produce this fusion protein to a level of about 1.6% of the total protein content, as deduced from beta-galactosidase activity. PMID:9665973

Liu, W F; Gao, D; Wang, Z N

1998-07-01

136

Proposed Approach to Stable High Beta Plasmas in ET  

NASA Astrophysics Data System (ADS)

Five second long plasmas have been produced in ET with ease. We need these long pulses to evolve high beta equilibria under controlled conditions. However, equilibrium control is lost to internal disruptions due to the development of giant sawteeth on the 1 second time scale. This time scale is approximately the central energy confinement time, while the central particle confinement time is much longer than 1 second. This persistent limitation is present in ohmic and ICRF heated discharges. MHD stable current profiles have been found using DCON(A.H. Glasser, private communication) but transport related phenomena like giant sawteeth and uncontrolled transport barrier evolution are not yet part of a simple stability study. We are advocating avoiding the evolution of giant sawtooth and conditions responsible for MHD instabilities as opposed to exploring their stabilization. This is equivalent to the statement that self-organized plasmas are in fact not welcome in long pulse tokamaks. We intend to prevent self-organization by the application of a multi-faceted ICRF strategy. The in house technology is ready but the approach needs to be artful and not preconceived. The flexibility built into the ET hardware is likely to help us to find a way to achieve global plasma control. It is essential that this work be pursued geared towards parameter performance and configuration control. Both require a significant commitment to understanding the device physics AND delivering on the engineering required for control and performance.

Taylor, R. J.; Carter, T. A.; Gauvreau, J.-L.; Gourdain, P.-A.; Grossman, A.; Lafonteese, D. J.; Pace, D. C.; Schmitz, L. W.

2003-10-01

137

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

Microsoft Academic Search

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

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

2002-01-01

138

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

139

Influence of transmutation and high neutron fluence on materials used in fission-fusion correlation experiments  

Microsoft Academic Search

This paper explores the response of three different materials to high fluence irradiation as observed in recent fusion-related experiments. While helium at fusion-relevant levels influences the details of the microstructure of Fe--Cr--Ni alloys somewhat, the resultant changes in swelling and tensile behavior are relatively small. Under conditions where substantially greater-than-fusion levels of helium are generated, however, an extensive refinement of

F. Garner

1990-01-01

140

a High-Efficiency Fusion Method of Multi-Spectral Image and Panchromatic Image  

NASA Astrophysics Data System (ADS)

With the development of modern remote sensing technology, a variety of earth observation satellites could continue to tremendously provide image data of different spatial resolution, time resolution, spectral resolution remote sensing, and the remote sensing data obtained is increasing with great capacity, which forms multi-source image pyramid in the same area. To play the advantages of a variety of remote sensing data, the application of remote sensing image fusion is a very important choice. When remote sensing data is large, fusion is large in computing capacity and time-consuming, so it is difficult to carry out rapid, real-time fusion. However, in some remote sensing applications, such as disaster prevention and relief quick, etc., timely fusion is required. Based on image fusion method of principal component analysis (PCA) and the advantage of parallel computing, a high-efficiency fusion method of multi-spectral image and panchromatic image is proposed. Beijing-1 Micro-satellite is a high-performance small satellite for earth observation?With Beijing-1 Micro-satellite remote sensing images as the experimental data, it is proved that good fusion results of multi-spectral image and panchromatic image can be obtained with the proposed method, and the fusion speed is also fast. At the same time, some measures of improving the efficiency of parallel image fusion are also discussed.

Xue, X.; Wang, J. P.; Wang, H.; Xiang, F.

2013-07-01

141

High-level Expression and Characterization of the Fusion Protein Consisting of Diphtheria Toxin and Human Interleukin 6.  

PubMed

Diphtheria toxin is a single chain exotoxin of 535 amino acids, secreted from beta Corynebacteriophage diphtheriae. Eukaryotic cells, especially tumor cells are very sensitive to DT. Just one or two molecules of DT can kill a cell. On the surface of some tumor cells, such as human myeloma, heptoma, etc, IL-6 receptor has been demonstrated to be expressed at a very-high level. Selective cytotoxicity mediated by IL-6 receptor could be useful in the targeting therapy of these tumors. Based on this strategy, a hybrid protein consisting of DT and IL-6 was constructed, expressed and characterized. IL-6 cDNA was first modified for constructing the fusion protein of DT/IL-6 and the receptor binding domain of DTDNA was replaced by IL-6 cDNA to obtain the expression vector pdeltaDT/TL-6. After induction by IPTG, the fusion protein was expressed successfully, accounting for 20% of the total bacterial protein. The results of SDS-PAGE and Western blot showed that there was a band of about 64 kD. After preliminary purification, the IL-6 receptor competitive binding test and the cytotoxic activity assay of the deltaDT/TL-6 showed that the fusion protein possessed significant cytotoxic activity to U266 cells; while the cells expressing IL-6 receptors at a medium-level was resistant it to a certain degree. PMID:12174278

Zhang, Xin-Jian; Li, Jing; Zhang, Bao-Yun; Hong, Tao

1998-01-01

142

High convergence, indirect drive inertial confinement fusion experiments at Nova  

SciTech Connect

High convergence, indirect drive implosion experiments have been done at the Nova Laser Facility. The targets were deuterium and deuterium/tritium filled, glass microballoons driven symmetrically by x rays produced in a surrounding uranium hohlraum. Implosions achieved convergence ratios of 24:1 with fuel densities of 19 g/cm{sup 3}; this is equivalent to the range required for the hot spot of ignition scale capsules. The implosions used a shaped drive and were well characterized by a variety of laser and target measurements. The primary measurement was the fuel density using the secondary neutron technique (neutrons from the reaction {sup 2}H({sup 3}H,{ital n}){sup 4}He in initially pure deuterium fuel). Laser measurements include power, energy and pointing. Simultaneous measurement of neutron yield, fusion reaction rate, and x-ray images provide additional information about the implosion process. Computer models are in good agreement with measurement results. {copyright} {ital 1996 American Institute of Physics.}

Lerche, R.A.; Cable, M.D.; Hatchett, S.P.; Caird, J.A.; Kilkenny, J.D.; Kornblum, H.N.; Lane, S.M.; Laumann, C.; Murphy, T.J.; Murray, J.; Nelson, M.B.; Phillion, D.W.; Powell, H.; Ress, D. [Lawrence Livermore National Laboratory, P.O. Box 5508, L-473, Livermore, California 94550 (United States)

1996-05-01

143

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

144

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

145

A Markov Random Field Model of Context for High-Level Information Fusion  

Microsoft Academic Search

This paper presents a method for inferring threat in a military campaign through matching of battle field entities to a doctrinal template. In this work the set of random variables denoting the possible template matches for the scenario entities is a realization of a Markov random field. This approach does not separate low level fusion from high level fusion but

Robin Glinton; Joseph Giampapa; Katia Sycara

2006-01-01

146

Laboratory Study of High-beta Plasma Shock Waves.  

National Technical Information Service (NTIS)

A plasma wind tunnel has been used to generate shock waves at rest in the laboratory reference frame. The upstream pressure ratio beta is in the range 1 to 3, and the Mach number based on the fast magnetosonic wave speed is 3 to 5. The shock wave is forme...

D. L. Morse W. W. Destler

1970-01-01

147

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

148

New directions in fusion machines: report on the MFAC Panel X on high power density options  

SciTech Connect

The high cost of fusion is motivating a shift in research interest toward smaller, lower-cost systems. Panel X of the Magnetic Fusion Advisory Committee (MFAC) was charged to assess the potential benefits and problems associated with small, high-power-density approaches to fusion. The Panel identified figures of merit which are useful in evaluating various approaches to reduce the development costs and capital costs of fusion systems. As a result of their deliberations, the Panel recommended that ''...increased emphasis should be given to improving the mass power density of fusion systems, aiming at a minimum target of 100 kWe/tonne'', and that ''Increased emphasis should be given to concepts that offer the potential to reduce substantially the cost of development steps in physics and technology.''

Linford, R.K.

1985-01-01

149

Operating experience with high beta superconducting rf cavities  

SciTech Connect

The number of installed and operational {beta} = 1 superconducting rf cavities has grown significantly over the last two years in accelerator laboratories in Europe, Japan and the US. The total installed acceleration capability as of mid-1993 is approximately 1 GeV at nominal gradients. Major installations at CERN, DESY, KEK and CEBAF have provided large increments to the installed base and valuable operational experience. A selection of test data and operational experience gathered to date is reviewed.

Dylla, H.F.; Doolittle, L.R.; Benesch, J.F.

1993-06-01

150

Experimental Evidence of High-Beta Plasma Confinement in an Axially Symmetric Gas Dynamic Trap  

NASA Astrophysics Data System (ADS)

In the axially symmetric magnetic mirror device gas dynamic trap (GDT), on-axis transverse beta (ratio of the transverse plasma pressure to magnetic field pressure) exceeding 0.4 in the fast ion turning points has been first achieved. The plasma has been heated by injection of neutral beams, which at the same time produced anisotropic fast ions. Neither enhanced losses of the plasma nor anomalies in the fast ion scattering and slowing down were observed. This observation confirms predicted magnetohydrodynamic stability of plasma in the axially symmetric mirror devices with average min-B, like the GDT is. The measured beta value is rather close to that expected in different versions of the GDT based 14MeV neutron source for fusion materials testing.

Ivanov, A. A.; Anikeev, A. V.; Bagryansky, P. A.; Deichuli, P. P.; Korepanov, S. A.; Lizunov, A. A.; Maximov, V. V.; Murakhtin, S. V.; Savkin, V. Ya.; den Hartog, D. J.; Fiksel, G.; Noack, K.

2003-03-01

151

Crystal structures of beta- and gammaretrovirus fusion proteins reveal a role for electrostatic stapling in viral entry.  

PubMed

Membrane fusion is a key step in the life cycle of all envelope viruses, but this process is energetically unfavorable; the transmembrane fusion subunit (TM) of the virion-attached glycoprotein actively catalyzes the membrane merger process. Retroviral glycoproteins are the prototypical system to study pH-independent viral entry. In this study, we determined crystal structures of extramembrane regions of the TMs from Mason-Pfizer monkey virus (MPMV) and xenotropic murine leukemia virus-related virus (XMRV) at 1.7-? and 2.2-? resolution, respectively. The structures are comprised of a trimer of hairpins that is characteristic of class I viral fusion proteins and now completes a structural library of retroviral fusion proteins. Our results allowed us to identify a series of intra- and interchain electrostatic interactions in the heptad repeat and chain reversal regions. Mutagenesis reveals that charge-neutralizing salt bridge mutations significantly destabilize the postfusion six-helix bundle and abrogate retroviral infection, demonstrating that electrostatic stapling of the fusion subunit is essential for viral entry. Our data indicate that salt bridges are a major stabilizing force on the MPMV and XMRV retroviral TMs and likely provide the key energetics for viral and host membrane fusion. PMID:24131724

Aydin, Halil; Cook, Jonathan D; Lee, Jeffrey E

2014-01-01

152

Crystal Structures of Beta- and Gammaretrovirus Fusion Proteins Reveal a Role for Electrostatic Stapling in Viral Entry  

PubMed Central

Membrane fusion is a key step in the life cycle of all envelope viruses, but this process is energetically unfavorable; the transmembrane fusion subunit (TM) of the virion-attached glycoprotein actively catalyzes the membrane merger process. Retroviral glycoproteins are the prototypical system to study pH-independent viral entry. In this study, we determined crystal structures of extramembrane regions of the TMs from Mason-Pfizer monkey virus (MPMV) and xenotropic murine leukemia virus-related virus (XMRV) at 1.7-? and 2.2-? resolution, respectively. The structures are comprised of a trimer of hairpins that is characteristic of class I viral fusion proteins and now completes a structural library of retroviral fusion proteins. Our results allowed us to identify a series of intra- and interchain electrostatic interactions in the heptad repeat and chain reversal regions. Mutagenesis reveals that charge-neutralizing salt bridge mutations significantly destabilize the postfusion six-helix bundle and abrogate retroviral infection, demonstrating that electrostatic stapling of the fusion subunit is essential for viral entry. Our data indicate that salt bridges are a major stabilizing force on the MPMV and XMRV retroviral TMs and likely provide the key energetics for viral and host membrane fusion.

Aydin, Halil; Cook, Jonathan D.

2014-01-01

153

Information fusion: a high-level architecture overview  

Microsoft Academic Search

Over the past decade the term Fusion has become synonymous with tactical or battle space awareness after hostilities have begun. As such, work has concentrated on object identification, tracking algorithms and. the use of multiple sources for reducing uncertainty and maximizing coverage. As more situations unfold throughout the world, smart strategic decisions must be made before deployment of our limited

J. Salerno

2002-01-01

154

An integrated approach to high-level information fusion  

Microsoft Academic Search

In today’s fast paced military operational environment, vast amounts of information must be sorted out and fused not only to allow commanders to make situation assessments, but also to support the generation of hypotheses about enemy force disposition and enemy intent. Current information fusion technology has the following two limitations. First, current approaches do not consider the battlefield context as

Katia P. Sycara; Robin Glinton; Bin Yu; Joseph A. Giampapa; Sean Owens; Michael Lewis; Charles E. Grindle

2009-01-01

155

SES-based ontological process for high level information fusion  

Microsoft Academic Search

Data Fusion (DF) process is in the interest of the military community since it provides the opportunity to achieve information superiority. The System Entity Structure (SES) is an ontology framework that can facilitate information exchange and represent knowledge in a network-centric environment. We explore an idea of adopting the SES ontology to fuse raw data into higher-level information in DF

Hojun Lee; Bernard P. Zeigler

2010-01-01

156

Fusion reactor high vacuum pumping: Charcoal cryosorber tritium exposure results.  

National Technical Information Service (NTIS)

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 t...

D. W. Sedgley C. R. Walthers E. M. Jenkins

1991-01-01

157

Feasibility of high resolution SAR and multispectral data fusion  

Microsoft Academic Search

Unlike PAN sharpening, the fusion of SAR with multispectral data involve use of non-overlapping spectral bands which poses certain inconsistencies viz. 1) radiometric differences due to their acquisition in entirely different spectral bands 2) geometric differences due to range and angular imaging of SAR and Optical sensors respectively. Apart from these, speckle noise and registration related factors will pose difficulties

R. Chandrakanth; J. Saibaba; Geeta Varadan; P. Ananth Raj

2011-01-01

158

High-temperature thermochemical water splitting cycle fusion reactor design considerations  

Microsoft Academic Search

The design considerations were explored for the adaptation of the high-temperature General Atomic sulfur-iodine thermochemical water splitting cycle to a fusion reactor heat source. This high-temperature cycle modification was found to have a good heat line match to the fusion heat source with an attractive possibility of process simplification compared to the reference HTGR-adapted cycle. The cost improvement due to

E. T. Cheng; C. P. C. Wong; K. H. McCorkle Jr.; P. W. Trester; K. R. Schultz

1980-01-01

159

Fusion power plant without plasma-material interactions.  

National Technical Information Service (NTIS)

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), an...

S. A. Cohen

1997-01-01

160

Resonant magnetohydrodynamic waves in high-beta plasmas  

SciTech Connect

When a global magnetohydrodynamic (MHD) wave propagates in a weakly dissipative inhomogeneous plasma, the resonant interaction of this wave with either local Alfven or slow MHD waves is possible. This interaction occurs at the resonant position where the phase velocity of the global wave coincides with the phase velocity of either Alfven or slow MHD waves. As a result of this interaction a dissipative layer embracing the resonant position is formed, its thickness being proportional to R{sup -1/3}, where R>>1 is the Reynolds number. The wave motion in the resonant layer is characterized by large amplitudes and large gradients. The presence of large gradients causes strong dissipation of the global wave even in very weakly dissipative plasmas. Very often the global wave motion is characterized by the presence of both Alfven and slow resonances. In plasmas with small or moderate plasma beta {beta}, the resonance positions corresponding to the Alfven and slow resonances are well separated, so that the wave motion in the Alfven and slow dissipative layers embracing the Alfven and slow resonant positions, respectively, can be studied separately. However, when {beta} > or approx. R{sup 1/3}, the two resonance positions are so close that the two dissipative layers overlap. In this case, instead of two dissipative layers, there is one mixed Alfven-slow dissipative layer. In this paper the wave motion in such a mixed dissipative layer is studied. It is shown that this motion is a linear superposition of two motions, one corresponding to the Alfven and the other to the slow dissipative layer. The jump of normal velocity across the mixed dissipative layer related to the energy dissipation rate is equal to the sum of two jumps, one that occurs across the Alfven dissipative layer and the other across the slow dissipative layer.

Ruderman, M. S. [Department of Applied Mathematics, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom)

2009-04-15

161

Beta and confinement experiments on Doublet III with high-power neutral beam heating  

SciTech Connect

Beta and energy confinement experiments with up to 7.5 MW of neutral beam heating power injected into both limited and diverted equilibria are discussed. We have studied beta limits at both the low q (high ..beta../sub T/, low ..beta../sub p/) and high q (low ..beta../sub T/, high ..beta../sub p/) ends of the ideal MHD n = infinity ballooning limit curve. Discharges which disruptively terminate have not clearly exceeded predicted ballooning limits but have been within 20% of marginal stability for ideal ballooning modes. Energy confinement time studies show that tau/sub E/ scales linearly with plasma current and deteriorates with beam power, although there are indications that tau/sub E/ may be approaching a new asymptotic value at high power levels. We find that diverted equilibria afford up to a factor of 2 greater confinement times at high power levels. Transport analysis indicates that electron conduction is the major heat loss mechanism and that the electron conductivity is generally 2--3 times lower in divertor discharges compared to limiter discharges with comparable parameters. We observe a strong correlation between improved confinement and the separation between the limiter and separatrix flux surface.

DeBoo, J.C.; Armentrout, C.J.; Baur, J.F.; Blau, F.P.; Bramson, G.; Burrell, K.H.; Chase, R.P.; Ejima, S.; Fairbanks, E.S.; Groebner, R.

1985-01-01

162

Beta and confinement experiments in Doublet III with high power neutral beam heating  

SciTech Connect

Beta and energy confinement experiments with up to 7.5 MW of neutral beam heating power injected into both limited and diverted equilibria are discussed. We have studied beta limits at both the low q (high ..beta../sub T/, low ..beta../sub p/) and high q (low ..beta../sub T/, high ..beta../sub p/) ends of the ideal MHD n = infinity ballooning limit curve. Discharges which disruptively terminate have not clearly exceeded predicted ballooning limits but have been within 20% of marginal stability for ideal ballooning modes. Energy confinement time studies show that tau/sub E/ scales linearly with plasma current and deteriorates with beam power, although there are indications that tau/sub E/ may be approaching a new asymptotic value at high power levels. We find that diverted equilibria afford up to a factor of two greater confinement times at high power levels. Transport analysis indicates that electron conduction is the major heat loss mechanism and that the electron conductivity is generally 2 to 3 times lower in divertor discharges compared to limiter discharges with comparable parameters. We observe a strong correlation between improved confinement and the separation between the limiter and separatrix flux surface.

DeBoo, J.C.; Armentrout, C.J.; Baur, J.F.; Blau, F.P.; Bramson, G.; Burrell, K.H.; Chase, R.P.; Ejima, S.; Fairbanks, E.S.; Groebner, R.

1984-06-01

163

High Level data fusion system for CanCoastWatch  

Microsoft Academic Search

In this paper, a goal-driven net-enabled distributed data fusion system is described for CanCoastWatch (CCW) project. Multiple sensors are deployed and managed to achieve the goals of situation assessment using a net-enabled architecture. The local tracks reported by multiple sensors are first integrated into global tracks. Decision making is then performed on basic sub-goals that can be directly derived from

Zhenhua Li; H. Leung; P. Valin; Hans Wehn

2007-01-01

164

Beta-barium borate as an electro-optic material for high power lasers  

SciTech Connect

The potential of Beta-Barium Borate (..beta..-BaB/sub 2/O/sub 4/) for use as an EO material is evaluated. The magnitude of the EO coefficient is due mainly to the electronic nonlinearity. The expected half-wave voltages and thermo-mechanical parameters of ..beta..-BaB/sub 2/O/sub 4/ plates in various configurations are calculated and compared with those of other materials of interest. Its resistance to thermal fracture, high damage threshold, and its wide range of transparency, make ..beta..-BaB/sub 2/O/sub 4/ an excellent candidate for use in a high average power Pockels cell, and as an intra-cavity laser Q-switch. 5 refs., 3 tabs.

Ebbers, C.A.

1988-08-11

165

Exposure fusion based on steerable pyramid for displaying high dynamic range scenes  

NASA Astrophysics Data System (ADS)

Currently, most exposure fusion algorithms are put forward on the assumption that the source images are aligned prior to fusion. As a result, some artifacts, such as haloing, may be caused due to the slight misalignment in the source images. In order to reduce the influence induced by the misalignment, a novel shift-invariant and rotation-invariant steerable pyramid-based exposure fusion (SPBEF) algorithm is proposed. It can combine multiple color images of a scene with different exposures to one image with high quality. First, instead of processing of R, G, and B channels separately, the chrominance information of the scene is obtained by the average image of the median two images. The strategy can greatly reduce the computational complexity. Second, the luminance images of source images are then transferred to frequency domain and are fused to one luminance image using different fusion rules in different frequencies. In this process, fusion is performed in a hierarchical fashion. Last, the final color image is generated by combining the data of the fused luminance image and the chrominance information. Experiments show that SPBEF can give comparative or even better results compared to other exposure fusion algorithms, as well as other traditional pyramid-based fusion algorithms

Wang, Jinhua; Xu, De; Li, Bing

2009-11-01

166

Repetitively pulsed, high energy KrF lasers for inertial fusion energy  

Microsoft Academic Search

Krypton fluoride (KrF) lasers produce highly uniform beams at 248 nm, allow the capability of 'zooming' the spot size to follow an imploding pellet, naturally assume a modular architecture and have been developed into a pulsed-power-based industrial technology that readily scales to a fusion power plant sized system. There are two main challenges for the fusion power plant application: to

M. C. Myers; J. D. Sethian; J. L. Giuliani; R. Lehmberg; P. Kepple; M. F. Wolford; F. Hegeler; M. Friedman; T. C. Jones; S. B. Swanekamp; D. Weidenheimer; D. Rose

2004-01-01

167

Imprecise Probability as an Approach to Improved Dependability in High-Level Information Fusion  

Microsoft Academic Search

The main goal of information fusion can be seen as improving human or automatic decision-making by exploiting diversities\\u000a in information from multiple sources. High-level information fusion aims specifically at decision support regarding situations,\\u000a often expressed as “achieving situation awareness”. A crucial issue for decision making based on such support is trust that\\u000a can be defined as “accepted dependence”, where dependence

Alexander Karlsson; Ronnie Johansson; Sten F. Andler

2008-01-01

168

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

169

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

170

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

171

Engineering of beta-propeller protein scaffolds by multiple gene duplication and fusion of an idealized WD repeat.  

PubMed

The ability to design specific amino acid sequences that fold into desired structures is central to engineering novel proteins. Protein design is also a good method to assess our understanding of sequence-structure and structure-function relationships. While beta-sheet structures are important elements of protein architecture, it has traditionally been more difficult to design beta-proteins than alpha-helical proteins. Taking advantage of the tandem repeated sequences that form the structural building blocks in a group of beta-propeller proteins; we have used a consensus design approach to engineer modular and relatively large scaffolds. An idealized WD repeat was designed from a structure-based sequence alignment with a set of structural guidelines. Using a plasmid sequential ligation strategy, artificial concatemeric genes with up to 10 copies of this idealized repeat were then constructed. Corresponding proteins with 4 through to 10 WD repeats were soluble when over-expressed in Escherichia coli. Notably, they were sufficiently stable in vivo surviving attack from endogenous proteases, and maintained a homogeneous, non-aggregated form in vitro. The results show that the beta-propeller scaffold is an attractive platform for future engineering work, particularly in experiments in which directed evolution techniques might improve the stability of the molecules and/or tailor them for a specific function. PMID:16651025

Nikkhah, Maryam; Jawad-Alami, Zahra; Demydchuk, Mykhaylo; Ribbons, Duncan; Paoli, Massimo

2006-09-01

172

High beta-HPV DNA loads and strong seroreactivity are present in epidermodysplasia verruciformis.  

PubMed

Epidermodysplasia verruciformis (EV) is a rare disease, characterized by cutaneous warts and associated with a strong predisposition to beta-genus human papillomavirus (HPV). Earlier studies reported high copy numbers of HPV-DNA in nearly all skin tumors from EV patients, but neither HPV replication status in non-lesional skin nor anti-HPV seroreactivity in these patients have been reported yet. We therefore performed a comprehensive viral load analysis for the more common beta-HPV types on skin samples and plucked eyebrow hairs from four EV patients treated at our dermatology department. The results clearly demonstrate that they carry a multiplicity (up to eighteen types) of beta-HPV genotypes in both skin sites. Worthy of note, a high intrapatient concordance for specific types between hair bulbs and skin biopsies was observed and the same beta-PV profile was maintained over time. Viral load analysis revealed a load range between less than one HPV-DNA copy per 100 cells to more than 400 HPV-DNA copies per cell in both eyebrow hairs and skin proliferative lesions. Evaluation of seroreactivity to beta-HPV types in the four EV patients revealed that antibodies against the 16 beta-HPV were significantly more prevalent and showed higher titers than in the controls. PMID:18923444

Dell'Oste, Valentina; Azzimonti, Barbara; De Andrea, Marco; Mondini, Michele; Zavattaro, Elisa; Leigheb, Giorgio; Weissenborn, Sönke J; Pfister, Herbert; Michael, Kristina M; Waterboer, Tim; Pawlita, Michael; Amantea, Ada; Landolfo, Santo; Gariglio, Marisa

2009-04-01

173

Acceleration of neon pellets to high speeds for fusion applications  

SciTech Connect

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 {approximately}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. {copyright} {ital 1996 American Institute of Physics.}

Combs, S.K.; Love, T.L.; Jernigan, T.C.; Milora, S.L. [Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831-8071 (United States)] [Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831-8071 (United States); Frattolillo, A.; Migliori, S. [ENEA, Centro Ricerche Energia Frascati, Frascati, Rome (Italy)] [ENEA, Centro Ricerche Energia Frascati, Frascati, Rome (Italy)

1996-03-01

174

Crystal structure and phonon instability of high-temperature beta-Ca(BH4)2  

Microsoft Academic Search

Ca(BH4)2 is an interesting candidate for high-density hydrogen storage since it contains a large amount of hydrogen by weight and volume, and has been shown to reversibly release and absorb hydrogen, albeit at moderately high temperatures. Ca(BH4)2 undergoes a polymorphic transformation around 400-440 K from a low-temperature alpha-Ca(BH4)2 phase to a high-temperature beta-Ca(BH4)2 phase. The crystal structure of beta-Ca(BH4)2 has

Young-Su Lee; Yoonyoung Kim; Young Whan Cho; Daniel Shapiro; Chris Wolverton; Vidvuds Ozolins

2009-01-01

175

Effects of vitamins C and E, acetylsalicylic acid and heparin on fusion, beta-hCG and PP13 expression in BeWo cells.  

PubMed

Preeclampsia is one of the leading causes for maternal and fetal morbidity. Placental protein 13 (PP13) is a placenta specific protein and with its decreased maternal serum levels in the first trimester it is one of the most promising markers to predict the syndrome in early pregnancy. In clinical trials attempts to prevent preeclampsia have already been made using low-dose aspirin, low-molecular-weight heparin, and antioxidants such as vitamins C and E. Here we investigated the effect of these agents on PP13 and beta-hCG levels using choriocarcinoma cell lines as surrogates for primary villous trophoblast. Five different cell lines were triggered with forskolin and cultured for 48 h. Amongst the five tested cell lines BeWo cells showed the strongest increase in PP13 mRNA after forskolin treatment compared to controls. Hence these cells were used to investigate the effect of varying concentrations of vitamin C, acetylsalicylic acid (ASA), Trolox) and heparin on cell fusion and PP13 and beta-hCG levels. The response to vitamin C was a dose-dependent increase in protein expression, while the other drugs showed only modest effects. Since first trimester PP13 has been shown to be significantly decreased in women subsequently developing preeclampsia, this data might point to a beneficial effect of very early vitamin C treatment of such women already in the early first trimester of pregnancy. PMID:20347141

Orendi, K; Gauster, M; Moser, G; Meiri, H; Huppertz, B

2010-05-01

176

High-Technology Companies Often Turn to Colleges for Confidential 'Beta Tests' of New Products.  

ERIC Educational Resources Information Center

Beta testing--the process of trying a product in a real-world setting before releasing it commercially--exploits a natural interface between universities and high-technology industries. High-tech companies need confidential, real-world tests of new products, and universities are eager to get an early look at tomorrow's technology. (MLW)

Turner, Judith Axler

1988-01-01

177

Synthesis of the membrane fusion and hemagglutinin proteins of measles virus, using a novel baculovirus vector containing the beta-galactosidase gene.  

PubMed Central

An improved baculovirus expression vector was developed to expedite screening and facilitate oligonucleotide-directed mutagenesis. This vector contained twin promoters derived from the P10 and polyhedrin genes of Autographica californica nuclear polyhedrosis virus. The P10 promoter directed the synthesis of beta-galactosidase, whereas the polyhedrin promoter controlled the synthesis of foreign gene products. These two genes recombined with wild-type virus genome to yield recombinants which were polyhedrin negative, produced the foreign gene product, and formed blue plaques when beta-galactosidase indicator was present in the agarose overlay. An origin of replication derived from M13 or f1 bacteriophage was also included in the plasmid to permit the synthesis of single-stranded DNA. This template DNA was used to introduce or delete sequences through the process of site-specific mutagenesis. The measles virus virion possesses a membrane envelope which contains two glycoproteins: the hemagglutinin (H) and membrane fusion (F) proteins. The H polypeptide has receptor-binding and hemagglutinating activity, whereas the F protein mediates virus penetration of the host cell, formation of syncytia, and hemolysis of erythrocytes. Genes for these two glycoproteins were inserted into the NheI cloning site of the modified expression vector described above. The vector and purified wild-type viral DNA were introduced into Sf9 insect cells by calcium phosphate precipitation. A mixture of wild-type and recombinant virus was generated and used to infect Sf9 cells, which were subsequently overlaid with agarose. After 3 days, 0.1 to 1% of the plaques became blue in the presence of beta-galactosidase indicator. At least 70% of these blue viral colonies contained the foreign gene of interest as determined by dot blot analysis. Recombinant virus was separated from contaminating wild-type virus through several rounds of plaque purification. Insect cells were then infected with the purified recombinants, and synthesis of H and F proteins were verified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by immunoblot detection and Coomassie blue staining. Glycosylation of the proteins appeared to be impaired somewhat, and the precursor to the F protein was not completely cleaved by the proteases present in insect host cells. On the other hand, both proteins appeared to be active in hemagglutination, hemolysis, and cell fusion assays. Levels of synthesis were in the order of 50 to 150 mg of protein per 10(8) cells. Images

Vialard, J; Lalumiere, M; Vernet, T; Briedis, D; Alkhatib, G; Henning, D; Levin, D; Richardson, C

1990-01-01

178

Magnetic fusion with high energy self-colliding ion beams  

SciTech Connect

Field-reversed configurations of energetic large orbit ions with neutralizing electrons have been proposed as the basis of a fusion reactor. Vlasov equilibria consisting of a ring or an annulus have been investigated. A stability analysis has been carried out for a long thin layer of energetic ions in a low density background plasma. There is a growing body of experimental evidence from tokamaks that energetic ions slow down and diffuse in accordance with classical theory in the presence of large non-thermal fluctuations and anomalous transport of low energy (10 keV) ions. Provided that major instabilities are under control, it seems likely that the design of a reactor featuring energetic self-colliding ion beams can be based on classical theory. In this case a confinement system that is much better than a tokamak is possible. Several methods are described for creating field reversed configurations with intense neutralized ion beams.

Rostoker, N.; Wessel, F. (California Univ., Irvine, CA (United States)); Maglich, B. (Advanced Physics Corp., Irvine, CA (United States)); Fisher, A. (Naval Research Lab., Washington, DC (United States))

1992-06-01

179

Role of high l values in the onset of incomplete fusion  

SciTech Connect

A particle-{gamma}-coincidence experiment is performed to investigate the role of high l values in the production of direct-{alpha}-emitting channels (associated with incomplete fusion) in {sup 12}C+{sup 169}Tm system. Spin distributions of various xn/pxn/{alpha}xn/2{alpha}xn channels are measured at E{sub lab}=5.6A and 6.5A MeV. Entirely different de-excitation patterns are observed in direct-{alpha}-emitting channels and fusion-evaporation channels. The fusion-evaporation channels are found to be strongly fed over a broad spin range. While narrow range feeding for only high-spin states was observed in the case of direct-{alpha}-emitting channels, in the present work, incomplete fusion is shown to be a promising tool to populate high-spin states in final reaction products. To have better insight into the associated l values in different reaction channels, the present data are compared with similar data obtained in {sup 16}O(E{sub lab}{approx_equal}5.6A MeV) + {sup 169}Tm system. The mean driving angular momenta involved in the production of direct-{alpha}-emitting channels are found to be higher than those involved in the production of fusion-evaporation channels. Direct-{alpha} multiplicity in the forward cone increases with driving angular momenta, which indicates the origin of direct-{alpha}-emitting channels at high l values in noncentral interactions.

Singh, Pushpendra P. [INFN - Laboratori Nazionali di Legnaro, I-35020 Legnaro (Italy); Yadav, Abhishek; Singh, Devendra P.; Gupta, Unnati; Singh, D.; Ansari, M. A.; Singh, B. P.; Prasad, R. [Accelerator Laboratory, Department of Physics, A. M. University, Aligarh 202 002 (India); Sharma, Manoj K. [Physics Department, S. V. College, Aligarh 202 001 (India); Kumar, R.; Singh, R. P.; Muralithar, S.; Bhowmik, R. K. [NP-Group, Inter-University Accelerator Center, New Delhi 110 067 (India)

2009-12-15

180

High current ion sources and injectors for induction linacs in heavy ion fusion  

Microsoft Academic Search

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

Joe W. Kwan

2005-01-01

181

Semantic Interoperability for High Level Information Fusion in Automotive Production Networks  

Microsoft Academic Search

Production networks have become widespread in automotive industry due to possibility to achieve high efficiency and flexibility that are currently of high importance. However, together with advantages the production networks pose new challenges. One of them is information fusion at the level of semantics. The paper describes an approach to this problem based on application of ontologies as a way

A. V. Smirnov; Nikolay Shilov; Tatiana Levashova; A. M. Kashevnik

2006-01-01

182

Ring-Toss: Capping highly exposed tyrosyl or tryptophyl residues in proteins with beta-cyclodextrin.  

PubMed

We have used UV difference spectroscopy and fluorescence spectroscopy to study the perturbation by beta-cyclodextrin of tyrosyl or tryptophyl residues located at each of the 10 variable consensus contact positions in the third domain of turkey ovomucoid. The goal was to monitor the accessibility of the side chain rings of these residues when located at these positions. The results indicated that the tyrosyl or tryptophyl rings are most highly exposed when located in the P1 position followed by the P4 position. It was possible to determine the association constants for beta-cyclodextrin binding at these positions. When located at the P2, P5, P6 and P3' positions, the rings of the tyrosyl or tryptophyl residues were exposed but less so than at the P1 or P4 positions. By contrast, when located at the P1', P2', P14' and P18' positions, the tyrosyl or tryptophyl residues were insufficiently exposed to be perturbed by beta-cyclodextrin, although they reacted positively to dimethyl sulfoxide solvent perturbation. These findings indicate that beta-cyclodextrin perturbation provides a convenient way to detect highly exposed tyrosyls or tryptophyls in proteins. Furthermore, we evaluated the ability of beta-cyclodextrin to inhibit the interaction of turkey ovomucoid third domain variants with different P1 residues. The results showed that the presence of beta-cyclodextrin had little effect on the association constant when the P1 residue was a glycyl residue, but greatly decreased the association constant when the P1 residue was a tyrosyl or tryptophyl residue. Thus, beta-cyclodextrin may be used to selectively modulate the interaction between proteinase inhibitors and their cognate enzymes. PMID:16417973

Yi, Zhengping; Qasim, M A; Qasim, Sabiha; Warrington, T L; Laskowski, Michael

2006-03-01

183

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 Subterráneo de Canfranc (LSC), Spain, in 2014.

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

2013-08-01

184

Scalings of steady state Hall magnetohydrodynamic reconnection in high-beta plasmas  

SciTech Connect

Scalings of Hall magnetohydrodynamics reconnection in high-{beta} plasmas has been studied in steady states. It again confirms previous temporal evolution reconnection results that while the width of the reconnection layer is scaled by {omega}{sub A}/{omega}{sub ci}=d{sub i}/L{sub c}, where {omega}{sub A} is the Alfven frequency, {omega}{sub ci} is the ion gyrofrequency, L{sub c} is the typical system length scale, and d{sub i}=c/{omega}{sub pi} is the ion inertial length, the length of the layer should be scaled by ({omega}{sub A}/{omega}{sub ci}){sup 1/2}L{sub c}=(d{sub i}L{sub c}){sup 1/2} [X. Wang and A. Bhattacharjee, Phys. Rev. Lett. 70, 1627 (1993)], to yield the fast reconnection rate of (d{sub i}/L{sub c}){sup 1/2}V{sub A} with V{sub A} as the Alfven velocity [X. Wang, A. Bhattacharjee, and Z. Ma, Phys. Rev. Lett. 87, 265003 (2001)]. It is also shown that the reconnection rate is proportional to the perturbed boundary flow. Furthermore it is found that in the high-{beta} plasmas, the reconnection keeps constant in the regime {beta}<2, and decays as {beta}{sup -1/2} for {beta}{>=}2.

Wang Xiaogang; Yang Hongang; Jin Shuping [State Key Lab of Materials Modification by Beams, Department of Physics, and College of Advanced Science and Technology, Dalian University of Technology, Dalian 116024 (China); School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026 (China)

2006-06-15

185

Application of fusion high-power RF techniques to the non-fusion field  

Microsoft Academic Search

The author presents examples of high-power RF applications covering a frequency range of a few MHz up to microwave frequencies of several GHz. All examples refer to the RF generation of nonfusion plasmas meanwhile for many important technical processes. Some specific items are: inductively driven RF discharge for ion beam extraction (for space propulsion, ion surface treatment and ion implantation),

R. Wilhelm

1993-01-01

186

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 (2.4±0.05)×10(15) DT, the fuel ?R was (0.86±0.063)??g/cm2, and the measured Tion was (4.2±0.16)??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; Döppner, 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

187

Neutron production from high-intensity laser cluster induced fusion reactions  

NASA Astrophysics Data System (ADS)

The fusion neutron yield from a compact neutron source is studied. Laser-irradiated deuterium clusters serve as a precursor of high-energy deuterons, which react with a tritium target and produce copious amounts of neutrons in fusion reactions. The Coulomb explosion of deuterium clusters with initial radius of 5 to 20 nm irradiated by a sub-picosecond laser with intensity ranging from 1015 to 1018 W cm-2 is examined theoretically by a MD model. The dependence of the mean and maximum ion kinetic energy, ion energy distribution function and conversion efficiency of laser energy to ion kinetic energy is investigated. The fusion yield was estimated from an ion beam-target model. A high neutron yield of ~106-107 neutrons/Joule is obtainable for peak laser intensity of 1016-1018 W cm-2, laser wavelength of 0.8-1 µm and clusters with an initial radius of ~ 20 nm.

Petrov, G. M.; Davis, J.; Velikovich, A. L.

2006-12-01

188

Microorifice-Based High-Yield Cell Fusion on Microfluidic Chip: Electrofusion of Selected Pairs and Fusant Viability  

Microsoft Academic Search

Microorifice-based fusion makes use of electric field constriction to assure high-yield one-to-one fusion of selected cell pairs. The aim of this paper is to verify feasibility of high-yield cell fusion on a microfluidic chip. This paper also examines viability of the fusant created on the chip. We fabricated a microfluidic chip to fuse selected cell pairs and to study postfusion

M. Gel; S. Suzuki; Y. Kimura; O. Kurosawa; B. Techaumnat; H. Oana; M. Washizu

2009-01-01

189

Diagnosing the High Energy Deuterium Spectra in IEC Devices Using Doppler Shifted Fusion Products  

NASA Astrophysics Data System (ADS)

The UW-Inertial Electrostatic Confinement (IEC) device is comprised of concentric spherical metallic grids within a cylindrical vacuum vessel. The central grid, which can be held at high negative potentials (˜ -100 to -200kV), is the device cathode, while the outer grid, held at ground potential, is the device anode. This configuration accelerates ions, created near the anode, toward the center of the device. A weakly ionized cold plasma, created by a filament assisted DC discharge outside the anode, is the ion source for the device. The fill gas for this device is typically deuterium, thus leading to D-D fusion rates on the order of 10^8 fusions/s. The high energy protons and tritons resultant from D-D fusion reactions have been observed using charged particle detectors. These detectors are capable of discerning the Doppler shift on D-D fusion products imparted by the center of mass energy of the deuterium reactants. From the fusion product spectra compiled by a multi-channel analyzer the energy spectra of the deuterium reactants can be calculated. Using this diagnostic the effect, on the deuterium spectra, of varying the parameters of fill gas pressure, cathode voltage, cathode current and grid geometry have been examined.

Boris, David

2008-11-01

190

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

191

High isoproterenol doses are required to activate beta3-adrenoceptor-mediated functions in dogs.  

PubMed

The "in vivo" conditions for beta3-adrenoceptors (beta-AR) activation by isoproterenol were investigated in dog. Experiments were carried out in anesthetized dogs using isoproterenol as a nonselective beta-AR agonist. Intravenous infusion of isoproterenol (0.4 nmol/kg/min) induced arterial hypotension and tachycardia with a slight decrease in cutaneous blood flow. At this dose, isoproterenol increased glucose, glycerol, and nonesterified fatty acid plasma levels. The changes in cardiovascular and endocrine-metabolic parameters, induced by the low dose of isoproterenol, were suppressed by pretreatment with nadolol (1 mg/kg, i.v.). After nadolol administration, however, a 10-fold higher dose (4 nmol/kg/min) of isoproterenol was able to induce a decrease in arterial blood pressure with a slight tachycardia and an increase in cutaneous blood flow. This high dose of isoproterenol increased nonesterified fatty acid and glycerol plasma levels but failed to change glucose plasma levels. All these effects were abolished by a pretreatment with nadolol (1 mg/kg, i.v.) plus SR59230A [a selective beta3-adrenoceptor antagonist; (3-(2-ethylphenoxy)-1(1S)-1,2,3,4-tetrahydronaphth-1-ylaminol-(2S)2-propanol oxalate); 1 mg/kg, i.v.]. Moreover, as observed with the high dose of isoproterenol under nadolol pretreatment, an infusion of SR58611A [a selective beta3-adrenoceptor agonist; ((N2S)-7-carbethoxymethoxy-1,2,3,4-tetrahydronaphth-2-yl-(2R)-2-hydroxy-2-chlorophenyl) ethanamine hydrochloride] induces a decrease in mean arterial blood pressure associated with an increase in heart rate, cutaneous blood flow, and nonesterified fatty acid and glycerol plasma levels. These results demonstrate that the in vivo activation of beta3-adrenoceptors requires higher doses of catecholamine than those necessary for beta1- and/or beta2-adrenoceptor stimulation. These results also argue for the lack of a beta3-AR involvement in the control of heart rate and glycogenolysis in dogs. PMID:12490598

Pelat, Michel; Verwaerde, Patrick; Galitzky, Jean; Lafontan, Max; Berlan, Michel; Senard, Jean-Michel; Montastruc, Jean-Louis

2003-01-01

192

Beta-alanine supplementation in high-intensity exercise.  

PubMed

Glycolysis involves the oxidation of two neutral hydroxyl groups on each glycosyl (or glucosyl) unit metabolised, yielding two carboxylic acid groups. During low-intensity exercise these, along with the remainder of the carbon skeleton, are further oxidised to CO(2) and water. But during high-intensity exercise a major portion (and where blood flow is impaired, then most) is accumulated as lactate anions and H(+). The accumulation of H(+) has deleterious effects on muscle function, ultimately impairing force production and contributing to fatigue. Regulation of intracellular pH is achieved over time by export of H(+) out of the muscle, although physicochemical buffers in the muscle provide the first line of defence against H(+) accumulation. In order to be effective during high-intensity exercise, buffers need to be present in high concentrations in muscle and have pK(a)s within the intracellular exercise pH transit range. Carnosine (?-alanyl-L-histidine) is ideal for this role given that it occurs in millimolar concentrations within the skeletal muscle and has a pK(a) of 6.83. Carnosine is a cytoplasmic dipeptide formed by bonding histidine and ?-alanine in a reaction catalysed by carnosine synthase, although it is the availability of ?-alanine, obtained in small amounts from hepatic synthesis and potentially in greater amounts from the diet that is limiting to synthesis. Increasing muscle carnosine through increased dietary intake of ?-alanine will increase the intracellular buffering capacity, which in turn might be expected to increase high-intensity exercise capacity and performance where this is pH limited. In this study we review the role of muscle carnosine as an H(+) buffer, the regulation of muscle carnosine by ?-alanine, and the available evidence relating to the effects of ?-alanine supplementation on muscle carnosine synthesis and the subsequent effects of this on high-intensity exercise capacity and performance. PMID:23075550

Harris, Roger C; Sale, Craig

2012-01-01

193

Cold fusion: Alchemist's dream  

NASA Astrophysics Data System (ADS)

In this report the following topics relating to cold fusion are discussed: muon catalyzed cold fusion; piezonuclear fusion; sundry explanations pertaining to cold fusion; cosmic ray muon catalyzed cold fusion; vibrational mechanisms in excited states of D2 molecules; barrier penetration probabilities within the hydrogenated metal lattice/piezonuclear fusion; branching ratios of D2 fusion at low energies; fusion of deuterons into He-4; secondary D+T fusion within the hydrogenated metal lattice; helium-3 to helium-4 ratio within the metal lattice; shock induced fusion; and anomalously high isotopic ratios of helium-3/helium-4.

Clayton, E. D.

1989-09-01

194

A Theta-Pinch Gun Used to Study High-beta Plasma Injection into Magnetic Fields.  

National Technical Information Service (NTIS)

A small theta-pinch gun has been developed for high-beta injection studies. The gun uses two independently energized coils to create a single doughnut-shaped plasma puff with an average density (in a 2-kG field) of 1-2 x 10 to the 15th power/cc, ion tempe...

R. Turner

1969-01-01

195

Endloss from a slender high beta plasma column contained in a linear solenoid  

Microsoft Academic Search

A model is presented to simulate endloss from a high beta plasma contained laterally in a straight solenoid. For slender plasma columns, the plasma lifetime depends on both the acoustic transit time (time for a sound wave to traverse one-half of the plasma length), and the characteristic radial diffusion time (diffusion of plasma across the magnetic field). In the limit

Loren C. Steinhauer

1976-01-01

196

Construction of a flocculent Saccharomyces cerevisiae strain secreting high levels of Aspergillus niger beta-galactosidase.  

PubMed

A flocculent Saccharomyces cerevisiae strain secreting Aspergillus niger beta-galactosidase activity was constructed by transforming S. cerevisiae NCYC869-A3 strain with plasmid pVK1.1 harboring the A. niger beta-galactosidase gene, lacA, under the control of the ADH1 promoter and terminator. Compared to other recombinant S. cerevisiae strains, this recombinant yeast has higher levels of extracellular beta-galactosidase activity. In shake-flask cultures, the beta-galactosidase activity detected in the supernatant was 20 times higher than that obtained with previously constructed strains (Domingues et al. 2000a). In bioreactor culture, with cheese-whey permeate as substrate, a yield of 878.0 nkat/gsubstrate was obtained. The recombinant strain is an attractive alternative to other fungal beta-galactosidase production systems as the enzyme is produced in a rather pure form. Moreover, the use of flocculating yeast cells allows for enzyme production with high productivity in continuous fermentation systems with facilitated downstream processing. PMID:11956748

Domingues, L; Teixeira, J A; Penttilä, M; Lima, N

2002-04-01

197

Second ballooning stability in high-beta, compact stellarators  

Microsoft Academic Search

Second ballooning stability is examined in two types of compact stellarator configurations. The first type are tokamak-stellarator hybrids with a high-shear, tokamak-like rotational transform profile [1] and the second type are Quasi-Poloidal Stellarator (QPS) plasmas with a low-shear, stellarator-like rotational transform profile [2]. Both types of configurations have |B| that is approximately poloidally symmetric and both have regions of second

A. S. Ware

2003-01-01

198

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

199

[Clinical and pharmacokinetic studies of high dose N4-behenoyl-1-beta-D-arabinofuranosylcytosine].  

PubMed

Effect of high dose of N4-behenoyl-1-beta-D-arabinofuranosylcytosine (BH-AC) was studied clinically and pharmacologically in non-Hodgkin's lymphoma and acute leukemia. The schedule of drug administration consisted of daily i.v. infusion for 5 consecutive days. The daily close was initiated with 500 mg/m2 which was escalated up to 1300 mg/m2. Eruption was found to be dose-limiting toxicity and there was no myelosuppression. The plasma concentration curve of BH-AC showed a biphasic curve. The half-lives of the initial phase (t1/2 alpha) and the second phase (t1/2 beta) by the administration (1 hr iv infusion) of 700 mg/m2 were 1.08 and 3.65 h respectively. The plasma 1-beta-D-arabinofuranosylcytosine was detected for 12-24 hr after infusion (Cmax: 0.26 microgram/ml). PMID:3592717

Yoshida, T; Nakamura, S; Ohtake, S; Ito, K; Kobayashi, K; Kanno, M; Hirai, J; Tachimori, K; Matsuda, T

1987-06-01

200

A high-temperature fusion blanket design for thermochemical hydrogen production  

Microsoft Academic Search

This paper presents the conceptual design of a technically viable fusion blanket having the capability to supply high-temperature process heat for the production of hydrogen via a modification of the General Atomic sulfur-iodine thermochemical water splitting cycle. To avoid the necessity of an expensive catalyst, and to allow the use of higher pressures and thus obtain a more compact, less

I. Maya; J. Battagalia; E. Cheng; R. Creedon; R. Goodrich; B. Jensen; K. Schultz; M. Simnad; P. Trester; G. Wong

1983-01-01

201

Laser irradiated atomic clusters: resonant heating, high energy ions and fusion yield  

Microsoft Academic Search

Summary form only given. Clusters are van der Waals bound solid density atomic aggregates formed in cooled gas jets. When irradiated with laser pulses the clusters ionize and explode giving rise to interesting non-linear phenomenon such as generation of high-energy electrons and ions, higher harmonics, and fusion neutrons. Our simulations indicate that laser pulse duration and intensity as well as

A. Gupta; J. P. Palastro; T. Antonsen; H. Milchberg; T. Taguchi

2006-01-01

202

Development of High Performance Nb3Sn Conductor for Fusion and Accelerator Applications  

Microsoft Academic Search

While the highest field performance is a primary goal of the conductor in the next generation of particle accelerators, emphasis has been focused mainly on the increase in current carrying capacity. The conductor needed for fusion application, however, requires much lower magnetization limit along with a critical current as high as possible. The upgraded strand specifications for the International Thermonuclear

Taeyoung Pyon; Jukka Somerkoski; Hem Kanithi; Ben Karlemo; Mikael Holm

2007-01-01

203

An empirical comparison of Bayesian and credal networks for dependable high-level information fusion  

Microsoft Academic Search

Bayesian networks are often proposed as a method for high-level information fusion. However, a Bayesian network relies on strong assumptions about the underlying probabilities. In many cases it is not realistic to require such precise probability assessments. We show that there exists a significant set of problems where credal networks outperform Bayesian networks, thus enabling more dependable decision making for

Alexander Karlsson; Ronnie Johansson; Sten F. Andler

2008-01-01

204

INFORM Lab: a testbed for high-level information fusion and resource management  

Microsoft Academic Search

DRDC Valcartier and MDA have created an advanced simulation testbed for the purpose of evaluating the effectiveness of Network Enabled Operations in a Coastal Wide Area Surveillance situation, with algorithms provided by several universities. This INFORM Lab testbed allows experimenting with high-level distributed information fusion, dynamic resource management and configuration management, given multiple constraints on the resources and their communications

Pierre Valin; Adel Guitouni; Eloi Bossé; Hans Wehn; Jens Happe

2011-01-01

205

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

206

Sensitivity to Error Fields in NSTX High Beta Plasmas  

SciTech Connect

It was found that error field threshold decreases for high ? in NSTX, although the density correlation in conventional threshold scaling implies the threshold would increase since higher ? plasmas in our study have higher plasma density. This greater sensitivity to error field in higher ? plasmas is due to error field amplification by plasmas. When the effect of amplification is included with ideal plasma response calculations, the conventional density correlation can be restored and threshold scaling becomes more consistent with low ? plasmas. However, it was also found that the threshold can be significantly changed depending on plasma rotation. When plasma rotation was reduced by non-resonant magnetic braking, the further increase of sensitivity to error field was observed.

Jong-Kyu Park, Jonathan E. Menard, Stefan P. Gerhardt, Richard J. Buttery, Steve A. Sabbagh, Ronald E. Bell and Benoit P. LeBlanc

2011-11-07

207

Final technical report. 1998 HU CFRT summer fusion high school workshop  

SciTech Connect

The center conducted its third High School Summer Fusion Science Workshop in Summer 1998. The center had only three faculty mentors available only for a part of Summer 1998, The center accepted four scholars in this workshop, Prof. Halima Ali coordinated this workshop. Each student was assigned to a research mentor according to the student's interest in a specific research area and problem. In the workshop in the center, the students received instructions and training in the basics of energy, plasma and fusion sciences. They also received one-on-one instructions and training by their mentors to further their understanding of the subject and to introduce to relevant concepts such as magnetic confinement fusion, tokamaks, diverters and area-preserving maps.

Ali, Halima; Punjabi, Alkesh

1999-07-01

208

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

209

High specificity of cphA-encoded metallo-beta-lactamase from Aeromonas hydrophila AE036 for carbapenems and its contribution to beta-lactam resistance.  

PubMed Central

The Aeromonas hydrophila AE036 chromosome contains a cphA gene encoding a metallo-beta-lactamase highly active against carbapenem antibiotics. This enzyme was induced in strain AE036 to the same extent by both benzylpenicillin and imipenem. When the cphA gene was inserted into plasmid pACYC184, used to transform Escherichia coli DH5 alpha, the MICs of imipenem, meropenem, and penem HRE664 for recombinant clone DH5 alpha(pAA20R), expressing the Aeromonas metallo-beta-lactamase, were significantly increased, but those of penicillins and cephalosporins were not. When the metallo-beta-lactamase purified from E. coli DH5 alpha(pAA20R) was assayed with several beta-lactam substrates, it hydrolyzed carbapenems but not penicillins or cephalosporins efficiently. These results demonstrate that this metallo-beta-lactamase possesses an unusual spectrum of activity compared with all the other class B enzymes identified so far, being active on penems and carbapenems only. This enzyme may thus contribute to the development of resistance to penems and carbapenems but not other beta-lactams.

Segatore, B; Massidda, O; Satta, G; Setacci, D; Amicosante, G

1993-01-01

210

Proteasome dysfunction mediates high glucose-induced apoptosis in rodent beta cells and human islets.  

PubMed

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, Cécile; Bosco, Domenico; Dalle, Stéphane; Wojtusciszyn, Anne

2014-01-01

211

I. The design, synthesis, and structure of antiparallel beta-sheet and beta-strand mimics. II. The design of a scripted chemistry outreach program to high schools  

NASA Astrophysics Data System (ADS)

I. Protein structure is not easily predicted from the linear sequence of amino acids. An increased ability to create protein structures would allow researchers to develop new peptide-based therapeutics and materials, and would provide insights into the mechanisms of protein folding. Toward this end, we have designed and synthesized two-stranded antiparallel beta-sheet mimics containing conformationally biased scaffolds and semicarbazide, urea, and hydrazide linker groups that attach peptide chains to the scaffold. The mimics exhibited populations of intramolecularly hydrogen-bonded beta-sheet-like conformers as determined by spectroscopic techniques such as FTIR, sp1H NMR, and ROESY studies. During our studies, we determined that a urea-hydrazide beta-strand mimic was able to tightly hydrogen bond to peptides in an antiparallel beta-sheet-like configuration. Several derivatives of the urea-hydrazide beta-strand mimic were synthesized. Preliminary data by electron microscopy indicate that the beta-strand mimics have an effect on the folding of Alzheimer's Abeta peptide. These data suggest that the urea-hydrazide beta-strand mimics and related compounds may be developed into therapeutics which effect the folding of the Abeta peptide into neurotoxic aggregates. II. In recent years, there has been concern about the low level of science literacy and science interest among Americans. A declining interest in science impacts the abilities of people to make informed decisions about technology. To increase the interest in science among secondary students, we have developed the UCI Chemistry Outreach Program to High Schools. The Program features demonstration shows and discussions about chemistry in everyday life. The development and use of show scripts has enabled large numbers of graduate and undergraduate student volunteers to demonstrate chemistry to more than 12,000 local high school students. Teachers, students, and volunteers have expressed their enjoyment of The UCI Chemistry Outreach Program to High Schools.

Waldman, Amy Sue

212

Production of large-radius, high-beta, confined mirror plasmas  

Microsoft Academic Search

This paper reports results of experiments in which mirror-confined plasmas with radii as high as 7 ion gyro-radii are produced and maintained by neutral-beam injection. In these plasmas, betas as high as 0.45 were achieved and limited only by the available neutral-beam power. Electron temperature and ion-energy confinement increased with larger plasma size.

D. L. Correll; J. H. Clauser; F. H. Coensgen; W. F. Cummins; R. P. Drake; J. H. Foote; A. H. Futch; R. K. Goodman; D. P. Grubb; G. M. Melin; W. E. Nexsen; T. C. Simonen; B. W. Stallard; W. C. Turner

1980-01-01

213

Pulmonary administration of interferon Beta-1a-fc fusion protein in non-human primates using an immunoglobulin transport pathway.  

PubMed

Currently, products containing interferon beta (IFN?) are injected either intramuscularly or subcutaneously. To avoid the necessity of injection, we developed a novel monomeric Fc fusion protein of IFN? (IFN?Fc) that is absorbed via an immunoglobulin transport system present in the upper and central airways upon administration of the drug as an inhaled aerosol. The systemic absorption of IFN?Fc through the lung in non-human primates, at deposited doses of 1, 3, and 10??g/kg, was compared to the absorption of a single 3??g/kg dose of IFN?-1a (Avonex®) subcutaneously administered. IFN?Fc was well absorbed through the lung, displaying dose proportional increases in serum concentrations, and was biologically active, as shown by increases in plasma neopterin levels. The circulating half-life of IFN?Fc was ?3 times longer (?30?h) than that of IFN?-1a, (8-9?h). At approximately equimolar doses of IFN?Fc (10??g/kg) and IFN?-1a (3??g/kg), the stimulation of neopterin over background levels was approximately equivalent, demonstrating that the longer half-life of IFN?Fc compensated for the lower relative specific antiviral activity of IFN?Fc measured in vitro. In conclusion, IFN?Fc was efficiently absorbed after pulmonary delivery in non-human primates, retained its biological activity, and may offer a convenient alternative to injectable IFN?. PMID:22191463

Vallee, Sebastien; Rakhe, Swapnil; Reidy, Thomas; Walker, Sandra; Lu, Qi; Sakorafas, Paul; Low, Susan; Bitonti, Alan

2012-04-01

214

Optical Lightpipe as a High-Bandwidth Fusion Diagnostic.  

National Technical Information Service (NTIS)

A recent series of experiments at the University of Rochester Laboratory for Laser Energetics OMEGA facility studied the feasibility of using radiation-to-light converters and high bandwidth optical signal transmission to remote recording devices as an al...

M. J. Moran R. A. Lerche G. Mant V. Y. Glebov T. C. Sangster J. M. Mack

2006-01-01

215

High-speed sensory-motor fusion for robotic grasping  

Microsoft Academic Search

In this paper a new high-speed vision device and its application to a grasp system is proposed, and we discuss a processing architecture for grasping based on visual and tactile feedback designed with real-time control in mind. First, we describe a high-speed vision chip that serves as a robotic eye that includes a general-purpose parallel processing array along with a

Akio Namiki; Takashi Komuro; Masatoshi Ishikawa

2002-01-01

216

Specific expression of GFP{sub uv}-{beta}1,3-N-acetylglucosaminyltransferase 2 fusion protein in fat body of Bombyx mori silkworm larvae using signal peptide  

SciTech Connect

Bombyxin (bx) and prophenoloxidase-activating enzyme (ppae) signal peptides from Bombyx mori, their modified signal peptides, and synthetic signal peptides were investigated for the secretion of GFP{sub uv}-{beta}1,3-N-acetylglucosaminyltransferase 2 (GGT2) fusion protein in B. mori Bm5 cells and silkworm larvae using cysteine protease deficient B. mori multiple nucleopolyhedrovirus (BmMNPV-CP{sup -} ) and its bacmid. The secretion efficiencies of all signal peptides were 15-30% in Bm5 cells and 24-30% in silkworm larvae, while that of the +16 signal peptide was 0% in Bm5 cells and 1% in silkworm larvae. The fusion protein that contained the +16 signal peptide was expressed specifically in the endoplasmic reticulum (ER) and in the fractions of cell precipitations. Ninety-four percent of total intracellular {beta}1,3-N-acetylglucosaminyltransferase ({beta}3GnT) activity was detected in cell precipitations following the 600, 8000, and 114,000g centrifugations. In the case of the +38 signal peptide, 60% of total intracellular activity was detected in the supernatant from the 114,000g spin, and only 1% was found in the precipitate. Our results suggest that the +16 signal peptide might be situated in the transmembrane region and not cleaved by signal peptidase in silkworm or B. mori cells. Therefore, the fusion protein connected to the +16 signal peptide stayed in the fat body of silkworm larvae with biological function, and was not secreted extracellularly.

Kato, Tatsuya [Laboratory of Biotechnology, Faculty of Agriculture, Shizuoka University, 836 Ohya Suruga-ku, Shizuoka 422-8529 (Japan); Park, Enoch Y. [Laboratory of Biotechnology, Faculty of Agriculture, Shizuoka University, 836 Ohya Suruga-ku, Shizuoka 422-8529 (Japan) and Laboratory of Biotechnology, Integrated Bioscience Section, Graduate School of Science and Technology, Shizuoka University, 836 Ohya Suruga-ku, Shizuoka 422-8529 (Japan)]. E-mail: yspark@agr.shizuoka.ac.jp

2007-08-03

217

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

218

High-level, beta-catenin/TCF-dependent transgene expression in secondary colorectal cancer tissue.  

PubMed

There is an urgent need for improved therapies for inoperable metastatic colon cancer. Gene-directed enzyme prodrug therapy (GDEPT) using adenovirus vectors works well in preclinical models of this disease, but successful clinical application is hampered by an inability to construct vectors that express at high levels in infected tumor cells but not in infected normal cells. Constitutive activation of beta-catenin-dependent gene expression is almost certainly a key causative event in the genesis of colon and some other cancers. Here we have exploited this oncogenic defect to design a synthetic promoter, CTP1, that, in contrast to currently available tumor-selective promoters, is both highly active in cancer cells and highly cancer-cell-specific. CTP1 directs high-level beta-galactosidase expression in freshly isolated biopsies of secondary colon cancer, but is not detectably active in associated normal liver tissue. We also demonstrate that CTP1 can direct high-level, tumor-specific therapeutic gene expression in vivo. Intratumoral injection of an adenovirus vector encoding Escherichia coli nitroreductase driven by CTP1 efficiently sensitized SW480 xenografts to the prodrug CB1954, whereas systemic vector and prodrug administration produced no apparent signs of toxicity. CTP1 may form the basis for effective, targeted gene therapy of metastatic colon cancer and other tumors with deregulated beta-catenin/T cell factor. PMID:11592840

Lipinski, K S; Djeha, A H; Ismail, T; Mountain, A; Young, L S; Wrighton, C J

2001-10-01

219

The High Current Transport Experiment for heavy-ion inertial fusion  

Microsoft Academic Search

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

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

2003-01-01

220

High temperatures in inertial confinement fusion radiation cavities heated with 0. 35 [mu]m light  

Microsoft Academic Search

We have demonstrated efficient coupling of 0.35 [mu]m laser light for radiation production in inertial confinement fusion (ICF) cavity targets. Temperatures of 270 eV are measured in cavities used for implosions and 300 eV in smaller cavities, significantly extending the temperature range attained in the laboratory to those required for high-gain indirect drive ICF. High-contrast, shaped drive pulses required for

Robert Kauffman; L. J. Suter; C. B. Darrow; J. D. Kilkenny; H. N. Kornblum; D. S. Montgomery; D. W. Phillion; M. D. Rosen; A. R. Theissen; R. J. Wallace; F. Ze

1994-01-01

221

High thermal conductivity of graphite fiber silicon carbide composites for fusion reactor application  

Microsoft Academic Search

The benefits of using CVI SiC\\/graphite fiber composites as low tritium retaining, high thermal conductivity composites for fusion applications are presented. Three-dimensional woven composites have been chemically vapor infiltrated with SiC and their thermophysical properties measured. One material used an intermediate grade graphite fiber in all directions (Amoco P55) while a second material used very high thermal conductive fiber (Amoco

L. L. Snead; M. Balden; R. A. Causey; H. Atsumi

2002-01-01

222

Semi-Automatically Generated High-Level Fusion for Multimodal User Interfaces  

Microsoft Academic Search

Reliable high-level fusion of several input modalities is hard to achieve, and(semi-)automatically generating it is even more difficult. However, it is important to address in order to broaden the scope of providing user interfaces semi-automatically.Our approach starts from a high-level discourse model created by a human interaction designer. It is modality independent, so an annotated discourse is semiautomatically generated, which

Dominik Ertl; Sevan Kavaldjian; Hermann Kaindl; Jürgen Falb

2010-01-01

223

EDITORIAL: The Nuclear Fusion Award The Nuclear Fusion Award  

NASA Astrophysics Data System (ADS)

The Nuclear Fusion Award ceremony for 2009 and 2010 award winners was held during the 23rd IAEA Fusion Energy Conference in Daejeon. This time, both 2009 and 2010 award winners were celebrated by the IAEA and the participants of the 23rd IAEA Fusion Energy Conference. The Nuclear Fusion Award is a paper prize to acknowledge the best distinguished paper among the published papers in a particular volume of the Nuclear Fusion journal. Among the top-cited and highly-recommended papers chosen by the Editorial Board, excluding overview and review papers, and by analyzing self-citation and non-self-citation with an emphasis on non-self-citation, the Editorial Board confidentially selects ten distinguished papers as nominees for the Nuclear Fusion Award. Certificates are given to the leading authors of the Nuclear Fusion Award nominees. The final winner is selected among the ten nominees by the Nuclear Fusion Editorial Board voting confidentially. 2009 Nuclear Fusion Award nominees For the 2009 award, the papers published in the 2006 volume were assessed and the following papers were nominated, most of which are magnetic confinement experiments, theory and modeling, while one addresses inertial confinement. Sabbagh S.A. et al 2006 Resistive wall stabilized operation in rotating high beta NSTX plasmas Nucl. Fusion 46 635-44 La Haye R.J. et al 2006 Cross-machine benchmarking for ITER of neoclassical tearing mode stabilization by electron cyclotron current drive Nucl. Fusion 46 451-61 Honrubia J.J. et al 2006 Three-dimensional fast electron transport for ignition-scale inertial fusion capsules Nucl. Fusion 46 L25-8 Ido T. et al 2006 Observation of the interaction between the geodesic acoustic mode and ambient fluctuation in the JFT-2M tokamak Nucl. Fusion 46 512-20 Plyusnin V.V. et al 2006 Study of runaway electron generation during major disruptions in JET Nucl. Fusion 46 277-84 Pitts R.A. et al 2006 Far SOL ELM ion energies in JET Nucl. Fusion 46 82-98 Berk H.L. et al 2006 Explanation of the JET n = 0 chirping mode Nucl. Fusion 46 S888-97 Urano H. et al 2006 Confinement degradation with beta for ELMy HH-mode plasmas in JT-60U tokamak Nucl. Fusion 46 781-7 Izzo V.A. et al 2006 A numerical investigation of the effects of impurity penetration depth on disruption mitigation by massive high-pressure gas jet Nucl. Fusion 46 541-7 Inagaki S. et al 2006 Comparison of transient electron heat transport in LHD helical and JT-60U tokamak plasmas Nucl. Fusion 46 133-41 Watanabe T.-H. et al 2006 Velocity-space structures of distribution function in toroidal ion temperature gradient turbulence Nucl. Fusion 46 24-32 2010 Nuclear Fusion Award nominees For the 2010 award, the papers published in the 2007 volume were assessed and the following papers were nominated, all of which are magnetic confinement experiments and theory. Rice J.E. et al 2007 Inter-machine comparison of intrinsic toroidal rotation in tokamaks Nucl. Fusion 47 1618-24 Lipschultz B. et al 2007 Plasma-surface interaction, scrape-off layer and divertor physics: implications for ITER Nucl. Fusion 47 1189-205 Loarer T. et al 2007 Gas balance and fuel retention in fusion devices Nucl. Fusion 47 1112-20 Garcia O.E et al 2007 Fluctuations and transport in the TCV scrape-off layer Nucl. Fusion 47 667-76 Zonca F. et al 2007 Electron fishbones: theory and experimental evidence Nucl. Fusion 47 1588-97 Maggi C.F. et al 2007 Characteristics of the H-mode pedestal in improved confinement scenarios in ASDEX Upgrade, DIII-D, JET and JT-60U Nucl. Fusion 47 535-51 Yoshida M. et al 2007 Momentum transport and plasma rotation profile in toroidal direction in JT-60U L-mode plasmas Nucl. Fusion 47 856-63 Zohm H. et al 2007 Control of MHD instabilities by ECCD: ASDEX Upgrade results and implications for ITER Nucl. Fusion 47 228-32 Snyder P.B. et al 2007 Stability and dynamics of the edge pedestal in the low collisionality regime: physics mechanisms for steady-state ELM-free operation Nucl. Fusion 47 961-8 Urano H. et al 2007 H-mode pedestal structure in the variation of toroidal rotation and toroidal f

Kikuchi, M.

2011-01-01

224

Deletions in the highly polymorphic region (HPR) of infectious salmon anaemia virus HPR0 haemagglutinin-esterase enhance viral fusion and influence the interaction with the fusion protein.  

PubMed

Since the discovery of a non-virulent infectious salmon anaemia virus (ISAV) HPR0 variant, many studies have speculated on the functional role of deletions within the highly polymorphic region (HPR) of genomic segment 6, which codes for the haemagglutinin-esterase (HE) protein. To address this issue, mutant HE proteins with deletions in their HPR were generated from the Scottish HPR0 template (NWM10) and fusion-inducing activity was measured using lipid (octadecyl rhodamine B) and content mixing assays (firefly luciferase). Segment six HPR was found to have a strong influence on ISAV fusion, and deletions in this near-membrane region predominantly increased the fusion-inducing ability of the resulting HE proteins. The position and length of the HPR deletions were not significant factors, suggesting that they may affect fusion non-specifically. In comparison, the amino acid composition of the associated fusion (F) protein was a more crucial criterion. Antibody co-patching and confocal fluorescence demonstrated that the HE and F proteins were highly co-localized, forming defined clusters on the cell surface post-transfection. The binding of erythrocyte ghosts on the attachment protein caused a reduction in the percentage of co-localization, suggesting that ISAV fusion might be triggered through physical separation of the F and HE proteins. In this process, HPR deletion appeared to modulate and reduce the strength of interaction between the two glycoproteins, causing more F protein to be released and activated. This work provides a first insight into the mechanism of virulence acquisition through HPR deletion, with fusion enhancement acting as a major contributing factor. PMID:24486627

Fourrier, Mickael; Lester, Katherine; Thoen, Even; Mikalsen, Aase; Evensen, Øystein; Falk, Knut; Collet, Bertrand; McBeath, Alastair

2014-05-01

225

JET intrinsic rotation studies in plasmas with a high normalized beta and varying toroidal field ripple  

NASA Astrophysics Data System (ADS)

Understanding the origin of rotation in ion cyclotron resonance frequency (ICRF) heated plasmas is important for predictions for burning plasmas sustained by alpha particles, being characterized by a large population of fast ions and no external momentum input. The angular velocity of the plasma column has been measured in JET H-mode plasmas with pure ICRF heating both for the standard low toroidal magnetic ripple configuration, of about ˜0.08% and, for increased ripple values up to 1.5% (Nave et al 2010 Phys. Rev. Lett. 105 105005). These new JET rotation data were compared with the multi-machine scaling of Rice et al (2007 Nucl. Fusion 47 1618) for the Alfvén-Mach number and with the scaling for the velocity change from L-mode into H-mode. The JET data do not fit well any of these scalings that were derived for plasmas that are co-rotating with respect to the plasma current. With the standard low ripple configuration, JET plasmas with large ICRF heating power and normalized beta, ?N ? 1.3, have a very small co-current rotation, with Alfvén-Mach numbers significantly below those given by the rotation scaling of Rice et al (2007 Nucl. Fusion 47 1618). In some cases the plasmas are actually counter-rotating. No significant difference between the H-mode and L-mode rotation is observed. Typically the H-mode velocities near the edge are lower than those in L-modes. With ripple values larger than the standard JET value, between 1% and 1.5%, H-mode plasmas were obtained where both the edge and the core counter-rotated.

Nave, M. F. F.; Eriksson, L.-G.; Giroud, C.; Johnson, T. J.; Kirov, K.; Mayoral, M.-L.; Noterdaeme, J.-M.; Ongena, J.; Saibene, G.; Sartori, R.; Rimini, F.; Tala, T.; de Vries, P.; Zastrow, K.-D.; Contributors, JET-EFDA

2012-07-01

226

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 µm (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

227

Z, ZX, and X-1: A Realistic Path to High Fusion Yield  

SciTech Connect

Z-pinches now constitute the most energetic and powerful sources of x-rays available by a large margin. The Z accelerator at Sandia National Laboratories has produced 1.8 MJ of x-ray energy, 280 TW of power, and hohlraum temperatures of 200 eV. These advances are being applied to inertial confinement fusion (ICF) experiments on Z. The requirements for high fusion yield are exemplified in the target to be driven by the X-1 accelerator. X-1 will drive two z-pinches, each producing 7 MJ of x-ray energy and about 1000 TW of x-ray power. Together, these radiation sources will heat a hohlraum containing the 4-mm diameter ICF capsule to a temperature exceeding 225 eV for about 10 ns, with the pulse shape required to drive the capsule to high fusion yield, in the range of 200--1000 MJ. Since X-1 consists of two identical accelerators, it is possible to mitigate the technical risk of high yield by constructing one accelerator. This accelerator, ZX, will bridge the gap from Z to X-1 by driving an integrated target experiment with a very efficient energy source, ZX will also provide experimental condition that the full specifications of the X-1 accelerator for high yield are achievable, and that a realistic path to high fission yield exists.

COOK, DONALD L.

1999-10-07

228

Catalytic asymmetric 1,4-addition reactions using alpha,beta-unsaturated N-acylpyrroles as highly reactive monodentate alpha,beta-unsaturated ester surrogates.  

PubMed

Synthesis and application of alpha,beta-unsaturated N-acylpyrroles as highly reactive, monodentate ester surrogates in the catalytic asymmetric epoxidation and Michael reactions are described. alpha,beta-Unsaturated N-acylpyrroles with various functional groups were synthesized by the Wittig reaction using ylide 2. A Sm(O-i-Pr)(3)/H(8)-BINOL complex was the most effective catalyst for the epoxidation to afford pyrrolyl epoxides in up to 100% yield and >99% ee. Catalyst loading was successfully reduced to as little as 0.02 mol % (substrate/catalyst = 5000). The high turnover frequency and high volumetric productivity of the present reaction are also noteworthy. In addition, a sequential Wittig olefination-catalytic asymmetric epoxidation reaction was developed, providing efficient one-pot access to optically active epoxides from various aldehydes in high yield and ee (96-->99%). In a direct catalytic asymmetric Michael reaction of hydroxyketone promoted by the Et(2)Zn/linked-BINOL complex, Michael adducts were obtained in good yield (74-97%), dr (69/31-95/5), and ee (73-95%). This represents the first direct catalytic asymmetric Michael reaction of unmodified ketone to an alpha,beta-unsaturated carboxylic acid derivative. The properties of alpha,beta-unsaturated N-acylpyrrole are also discussed. Finally, the utility of the N-acylpyrrole unit for further transformations is demonstrated. PMID:15198603

Matsunaga, Shigeki; Kinoshita, Tomofumi; Okada, Shigemitsu; Harada, Shinji; Shibasaki, Masakatsu

2004-06-23

229

INFORM Lab: a testbed for high-level information fusion and resource management  

NASA Astrophysics Data System (ADS)

DRDC Valcartier and MDA have created an advanced simulation testbed for the purpose of evaluating the effectiveness of Network Enabled Operations in a Coastal Wide Area Surveillance situation, with algorithms provided by several universities. This INFORM Lab testbed allows experimenting with high-level distributed information fusion, dynamic resource management and configuration management, given multiple constraints on the resources and their communications networks. This paper describes the architecture of INFORM Lab, the essential concepts of goals and situation evidence, a selected set of algorithms for distributed information fusion and dynamic resource management, as well as auto-configurable information fusion architectures. The testbed provides general services which include a multilayer plug-and-play architecture, and a general multi-agent framework based on John Boyd's OODA loop. The testbed's performance is demonstrated on 2 types of scenarios/vignettes for 1) cooperative search-and-rescue efforts, and 2) a noncooperative smuggling scenario involving many target ships and various methods of deceit. For each mission, an appropriate subset of Canadian airborne and naval platforms are dispatched to collect situation evidence, which is fused, and then used to modify the platform trajectories for the most efficient collection of further situation evidence. These platforms are fusion nodes which obey a Command and Control node hierarchy.

Valin, Pierre; Guitouni, Adel; Bossé, Eloi; Wehn, Hans; Happe, Jens

2011-05-01

230

MHD Stability Calculations of High-Beta Quasi-Axisymmetric Stellarators  

SciTech Connect

The MHD stability of quasi-axisymmetric compact stellarators is investigated. It is shown that bootstrap current driven external kink modes can be stabilized by a combination of edge magnetic shear and appropriate 3D plasma boundary shaping while maintaining good quasi-axisymmetry. The results demonstrate that there exists a new class of stellarators with quasi-axisymmetry, large bootstrap current, high MHD beta limit, and compact size.

C. Kessel; G.Y. Fu; L.P. Ku; M.H. Redi; N. Pomphrey; et al

1999-09-01

231

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

232

Beta-endorphin immunoreactivity during high-intensity exercise with and without opiate blockade.  

PubMed

Nine highly fit men [mean (SE) maximum oxygen uptake, VO2max: 63.9 (1.7) ml x kg(-1) x min(-1); age 27.6 (1.6) years] were studied during two treadmill exercise trials to determine plasma beta-endorphin immunoreactivity during intense exercise (80% VO2max). A double-blind experimental design was used, and subjects performed the two exercise trials in counterbalanced order. Exercise trials were 30 min in duration and were conducted 7 days apart. One exercise trial was undertaken following administration of naloxone (1.2 3 cm3) and the other after receiving a placebo (0.9% NaCl saline; 3 cm3). Prior to each experimental trial, a flexible catheter was placed into an antecubital vein and baseline blood samples were collected. Thereafter, each subject received either a naloxone or placebo bolus injection. Blood samples were also collected after 10, 20 and 30 min of continuous exercise. beta-Endorphin was higher (P < 0.05) during exercise when compared to pre-exercise in both trials. However, no statistically significant difference was found (P> 0.05) between exercise time points within either experimental trial. beta-endorphin immunoreactivity was greater (P < 0.05) in the naloxone than in the placebo trial during each exercise sampling time point [10 min: 63.7 (3.9) pg x ml(-1) vs 78.7 (3.8) pg x ml(-1); 20 min: 68.7 (4.1) pg x ml(-1) vs (4.3) pg x ml(-1); 30 min: 71.0 (4.3) pg x ml(-1) vs 82.5(3.2) pg x ml(-1)]. These data suggest that intense exer induces significant increases in beta-endorphin that are maintained over time during steady-rate exercise. Exercise and naloxone had an interactive effect on beta-endorphin release that warrants further investigation. PMID:11820329

Angelopoulos, T J

2001-11-01

233

a High-Density Mirror Fusion Reactor for Space and Terrestrial Applications  

NASA Astrophysics Data System (ADS)

A high density, mirror-type fusion reactor is proposed as a high performance propulsion system that would allow manned missions to Mars, or other interplanetary journeys, to be undertaken in relatively short times. Because of the high temperature plasma confined in this magnetic configuration, which can also serve as a magnetic nozzle, a very large specific impulse (I_{^ }) is generated in addition to the large thrust that results from the ejection of the high density fuel. Since the collision mean free path for the plasma particles is much smaller than the characteristic dimension of the system, the plasma in a high-performance fusion rocket (HIFUR) behaves much like a continuous medium (a fluid) for which the confinement time is drastically different from that which characterizes a mirror fusion power reactor. Noting this fact, and using an appropriate set of particle and energy balance equations for the reactants and reaction products, we calculate the length and the propulsive properties of the proposed rocket. We find that a moderately sized system can produce very large values of specific impulse and thrust to allow a massive rocket to make a round trip from earth to Mars in months instead of years. It is also shown that HIFUR has a capability of producing a gain factor of 30 or higher for reasonable lengths and thus has a possibility of replacing the conventional mirror fusion reactor for electric power production. By carrying out a preliminary engineering design, we identify those technological areas that must be developed in order to make this system workable. We find that many of these technologies are surprisingly reachable now, or in the not too distant future.

Lee, Myoung-Jae

234

High yield expression of catalytically active USP18 (UBP43) using a Trigger Factor fusion system  

PubMed Central

Background Covalent linkage of the ubiquitin-like protein ISG15 interferes with viral infection and USP18 is the major protease which specifically removes ISG15 from target proteins. Thus, boosting ISG15 modification by protease inhibition of USP18 might represent a new strategy to interfere with viral replication. However, so far no heterologous expression system was available to yield sufficient amounts of catalytically active protein for high-throughput based inhibitor screens. Results High-level heterologous expression of USP18 was achieved by applying a chaperone-based fusion system in E. coli. Pure protein was obtained in a single-step on IMAC via a His6-tag. The USP18 fusion protein exhibited enzymatic activity towards cell derived ISG15 conjugated substrates and efficiently hydrolyzed ISG15-AMC. Specificity towards ISG15 was shown by covalent adduct formation with ISG15 vinyl sulfone but not with ubiquitin vinyl sulfone. Conclusion The results presented here show that a chaperone fusion system can provide high yields of proteins that are difficult to express. The USP18 protein obtained here is suited to setup high-throughput small molecule inhibitor screens and forms the basis for detailed biochemical and structural characterization.

2012-01-01

235

Isolation of a highly specific ligand for the alpha 5 beta 1 integrin from a phage display library  

PubMed Central

Our previous studies showed that the alpha 5 beta 1 integrin selects cysteine pair-containing RGD peptides from a phage display library based on a random hexapeptide. We have therefore searched for more selective peptides for this integrin using a larger phage display library, where heptapeptides are flanked by cysteine residues, thus making the inserts potentially cyclic. Most of the phage sequences that bound to alpha 5 beta 1 (69 of 125) contained the RGD motif. Some of the heptapeptides contained an NGR motif. As the NGR sequence occurs in the cell-binding region of the fibronectin molecule, this sequence could contribute to the specific recognition of fibronectin by alpha 5 beta 1. Selection for high affinity peptides for alpha 5 beta 1 surprisingly yielded a sequence RRETAWA that does not bear obvious resemblance to known integrin ligand sequences. The synthetic cyclic peptide GACRRETAWACGA (*CRRETAWAC*) was a potent inhibitor of alpha 5 beta 1-mediated cell attachment to fibronectin. This peptide is nearly specific for the alpha 5 beta 1 integrin, because much higher concentrations were needed to inhibit the alpha v beta 1 integrin, and there was no effect on alpha v beta 3- and alpha v beta 5-mediated cell attachment to vitronectin. The peptide also did not bind to the alpha IIb beta 3 integrin. *CRRETAWAC* appears to interact with the same or an overlapping binding site in alpha 5 beta 1 as RGD, because cell attachment to *CRRETAWAC* coated on plastic was divalent cation dependent and could be blocked by an RGD-containing peptide. These results reveal a novel binding specificity in the alpha 5 beta 1 integrin.

1994-01-01

236

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

237

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

238

KSTAR equilibrium operating space and projected stabilization at high normalized beta  

NASA Astrophysics Data System (ADS)

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 0.83 kW 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.; Sabbagh, S. A.; Berkery, J. W.; Bialek, J. M.; Jeon, Y. M.; Hahn, S. H.; Eidietis, N.; Evans, T. E.; Yoon, S. W.; Ahn, J.-W.; Kim, J.; Yang, H. L.; You, K.-I.; Bae, Y. S.; Chung, J.; Kwon, M.; Oh, Y. K.; Kim, W.-C.; Kim, J. Y.; Lee, S. G.; Park, H. K.; Reimerdes, H.; Leuer, J.; Walker, M.

2011-05-01

239

High speed plasma diagnostics for laser plasma interaction and fusion studies  

Microsoft Academic Search

Laser plasma interaction and fusion studies involve many high speed plasma diagnostics to determine the various parameters\\u000a for explaining the physical processes taking place in plasma. Detection and analysis of short-term or transient radiations\\u000a (X-ray and visible) are the bases for diagnosing the physical processes occurring during laser-plasma interaction or similar\\u000a radiation-emitting processes. This paper reviews the development of various

V N Rai; M Shukla; H C Pant; D D Bhawalkar

1999-01-01

240

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

241

Sensor Fusion for a Network of Processes/Systems with Highly Autonomous Sensors  

NASA Technical Reports Server (NTRS)

This paper describes a distributed sensor-data-fusion paradigm and theory based on a previously developed theory to model sensors as highly autonomous units. Generic procedures are defined to reason and make decisions at the qualitative level. This facilitates distribution of intelligence ( code and hardware) to the sensor level and peer-to-peer communication among sensors, controllers, and other devices in the system.

Figueroa, Fernando; Yuan, Xiao-Jing

2000-01-01

242

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

243

High-Level Fusion of Depth and Intensity for Pedestrian Classification  

Microsoft Academic Search

This paper presents a novel approach to pedestrian classification which involves a high-level fusion of depth and intensity\\u000a cues. Instead of utilizing depth information only in a pre-processing step, we propose to extract discriminative spatial features\\u000a (gradient orientation histograms and local receptive fields) directly from (dense) depth and intensity images. Both modalities\\u000a are represented in terms of individual feature spaces,

Marcus Rohrbach; Markus Enzweiler; Dariu M. Gavrila

2009-01-01

244

Stability Control for High-beta Plasmas on JT-60SA  

NASA Astrophysics Data System (ADS)

JT-60SA is designed and under construction as fully superconducting tokamak under a combined project of the ITER satellite tokamak program of EU-JA (Broader Approach Activities) and the Japanese national program. One of the main purposes of JT-60SA is the steady-state high-beta operation above the ideal no-wall beta-limit with suppressing resistive wall modes (RWMs). In order to control the RWMs, the RWM control coils and error field correction coils (EFCCs) are to be installed. The current design of these coils composes of 18 sector coils (6 coils in toroidally and 3 coils in poloidally) so as to suppress n=1-3 RWMs and to compensate various error fields. The EFCCs can also be utilized to apply the resonant magnetic perturbation to ergodize the peripheral magnetic filed structure to mitigate and avoid the large edge localized modes. The design and analysis of these in-vessel tools for high-beta plasmas on JT-60SA will be presented.

Matsunaga, G.; Takechi, M.; Sakurai, S.; Ide, S.; Matsukawa, M.; Oyama, N.; Aiba, N.; Kurita, G.; Ferro, A.; Gaio, E.; Novello, L.; Sakasai, S.; Kamada, Y.

2009-11-01

245

Synthesis of highly substituted cyclobutane fused-ring systems from N-vinyl beta-lactams through a one-pot domino process.  

PubMed

In this contribution, aminocyclobutanes, as well as eight-membered enamide rings, have been made from N-vinyl beta-lactams. The eight-membered products have been formed by a [3,3]-sigmatropic rearrangement, whereas the aminocyclobutanes have been derived from a domino [3,3]-rearrangement/6pi-electrocyclisation process. The aminocyclobutanes have been obtained in a highly diastereoselective fashion. The cyclobutane ring system tolerates fusion even if adjacent quaternary centres are present. Systems containing up to four fused rings are readily accessible. The reaction profile has been investigated by using Gaussian 03. This study suggests that two reaction pathways for aminocyclobutane formation are possible. In one pathway the [3,3]-sigmatropic rearrangement is the rate-limiting step and in the second pathway the electrocyclisation is rate limiting. Taken together, these reactions should facilitate the construction of fused heterocycles. PMID:20186912

Cheung, Lawrence L W; Yudin, Andrei K

2010-04-01

246

3-D simulations of limiter stabilization of high-beta external kink-tearing modes  

SciTech Connect

The effects of finite-size poloidal limiters, toroidal limiters, and general mushroom limiters are examined for high-beta finite-resistivity tokamak plamas in free boundary. Even for a linear stability analysis, a 3-D simulation is necessary, in which many poloidal and toroidal modes are coupled because of the limiter constraint and finite-beta. When the plasma pressure and resistivity are small, a poloidal limiter is effective in reducing the growth rate with a small limiter-size, while a toroidal limiter requires a large size for a comparable effect. As the plasma pressure or resistivity increases, a toroidal limiter becomes more effective in reducing the growth rate than a poloidal limiter of the same size. A small optimized mushroom limiter might have a stabilizing effect similar to a conducting shell.

Lee, J.K.; Ohyabu, N.

1984-03-01

247

High-statistics study of the beta-decay of 110In  

NASA Astrophysics Data System (ADS)

The stable even-even Cd isotopes have been considered excellent examples of vibrational nuclei, especially 110Cd and 112Cd. We have initiated a program at the TRIUMF-ISAC radioactive beam facility using the 8pi spectrometer and its associated auxiliary detectors to study these isotopes via high-statistics beta-decay measurements. To date, the decays of 112Ag/112In and 110In have been studied. The present work concentrates on the beta decay measurement of 110In to 110Cd. The data were collected in scaled-down gamma singles, gamma-gamma coincidence, and gamma-electron coincidence mode. A total of 850 million events have been sorted into a random-background subtracted gamma-gamma matrix. Details of the analysis to date will be reported.

Diaz Varela, Alejandra; Garrett, P. E.; Ball, G. C.; Bangay, J.; Cross, D.; Demand, G. A.; Garnsworthy, A. B.; Green, K. L.; Hackman, G.; Kulp, W. D.; Leach, K. G.; Sumithrarachchi, C.; Svensson, C. E.; Triambak, S.; Wong, J.; Wood, J. L.; Yates, S. W.

2010-11-01

248

Suppression of NTM Towards Stationary High-Beta Plasmas in JT-60U  

NASA Astrophysics Data System (ADS)

Results from stabilization of neoclassical tearing modes (NTMs) in JT-60U are described. NTM stabilization and confinement improvement have been demonstrated by employing a real-time NTM stabilization system, where the identification of the location of an NTM and the optimization of the injection angle of the electron cyclotron wave are performed in real time. Also, a high-beta plasma with the normalized beta of 3 has been sustained by suppressing NTM by applying the electron cyclotron current drive (ECCD) before the onset (`preemptive ECCD'). In addition, a simulation code for analysis of the NTM evolution has been developed by combining the modified Rutherford equation with the transport code TOPICS. It is found that the simulation well reproduces the NTM behavior in JT-60U. The simulation also shows that the ECCD width is also important for NTM stabilization, and that the EC wave power for complete stabilization can be reduced by narrowing the ECCD profile.

Isayama, A.; JT-60 Team

2006-01-01

249

High-performance deuterium-lithium neutron source for fusion materials and technology testing  

SciTech Connect

Advances in high-current linear-accelerator technology since the design of the Fusion Materials Irradiation Test (FMIT) Facility have increased the attractiveness of a deuterium-lithium (D-Li) neutron source for fusion materials and technology testing. This paper discusses a new approach to such a source aimed at meeting the near-term requirements of a high-flux high-energy International Fusion Materials Irradiation Facility (IFMIF). The concept employs multiple accelerator modules providing deuteron beams to two liquid-lithium jet targets oriented at right angles. This beam/target geometry provides much larger test volumes than can be attained with a single beam and target and produces significant regions of low neutron-flux gradient. A preliminary beam-dynamics design has been obtained for a 250-mA reference accelerator module. Neutron-flux levels and irradiation volumes were calculated for a neutron source incorporating two such modules, and interaction of the beam with the lithium jet was studied using a thermal-hydraulic computer simulation. Cost estimates are provided for a range of beam currents and a possible facility staging sequence is suggested. 12 refs., 7 figs., 3 tabs.

Lawrence, G.P.; Bhatia, T.S.; Blind, B.; Guy, F.W.; Krakowski, R.A.; Neuschaefer, G.H.; Schnurr, N.M.; Schriber, S.O.; Varsamis, G.L.; Wangler, T.P.

1989-01-01

250

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

251

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

252

Creation of a high density, high flux target plasmoid for magneto-inertial fusion  

NASA Astrophysics Data System (ADS)

Magneto-inertial fusion utilizes embedded magnetic fields to reduce thermal transport and enhance alpha particle heating during an implosion reducing the required areal density, implosion speed, and convergence for fusion ignition. This enables the use of efficient inexpensive pulsed power, reducing the gain required for breakeven (e.g. ?G = 0.5*10 (MIF), = 0.05*100 (ICF)). The FRX-L and FRCHX experiments at Los Alamos National Laboratory and the Air Force Research Laboratory at Kirtland AFB are investigating a subset of MIF called Magnetized Target Fusion (MTF) in which a Field Reversed Configuration (FRC) plasmoid is injected into a converging solid, conductive liner and compressed to fusion conditions. Traditional FRC formation techniques utilizing ringing-? pre-ionization have proved to be incapable of forming target plasmoids with enough density and magnetic flux, limiting the particle inventory, confinement, and lifetime. An alternative formation technique utilizing magnetoplasmadynamic arc sources has been developed to increase the density and trapped flux of the target plasmoid. Plasma source technology and operation are presented, as well as changes to the target formation process, plasmoid characteristics, and implications to MTF.

Weber, Thomas; Intrator, Thomas; Sears, Jason

2011-11-01

253

Final Report on The Theory of Fusion Plasmas  

SciTech Connect

Report describes theoretical research in the theory of fusion plasmas funded under grant DE-FG02-04ER54737. This includes work on: explosive instabilities, plasma turbulence, Alfven wave cascades, high beta (pressure) tokamaks and magnetic reconnection. These studies have lead to abetter understanding of fusion plasmas and in particular the future behavior of ITER. More than ten young researchers were involved in this research -- some were funded under the grant.

Steven C. Cowley

2008-06-17

254

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

255

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

NASA Astrophysics Data System (ADS)

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.

2008-07-01

256

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. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Perkins, L. J.; Barnard, J. J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2008-07-15

257

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

258

A comprehensive molecular characterization of beta thalassemia in a highly heterogeneous population.  

PubMed

In Iran, the prevalence of beta-thalassemia trait is approximately 4-8% in most areas, and in Mazandaran province 10% of the population are carriers. Twenty four beta-globin gene mutations were identified in 1635 persons with beta-thalassemia trait using reverse dot blot and restriction fragment length polymorphism analysis. The predominant mutations included IVSII-1 (G-A) (61%), codon 30 (G-C) (7.5%), codon 22 (-7bp) (6.2%), codon 8 (-AA) (5.4%) and IVSI-5 (G-C) (3.6%). These mutations were in different haplotypes, with IVSII-1 being the most heterogeneous. Other less frequent mutations included IVS-II-745 (C-G), codon 44 (-C), codon 39 (C-T), codon 5 (-CT), IVS I-110 (G-A), IVSI-130 (G-C), Fr8/9 (+G), IVSI-1 (G-A), and IVSI (-25bp). All rare mutations except IVSI-130 were encountered in a unique haplotype. The diversity of these mutations reflects the historical admixture of genes in the region. The high prevalence of IVSII-1 (G-A) compared to other parts of the country and the world suggests a founder effect. Our data provide a basis for genetic counseling and prenatal diagnosis. PMID:21493114

Akhavan-Niaki, Haleh; Derakhshandeh-Peykar, Poupak; Banihashemi, Ali; Mostafazadeh, Amrollah; Asghari, Beheshteh; Ahmadifard, Mohammad-Reza; Azizi, Mandana; Youssefi, Ali; Elmi, Maryam Mitra

2011-06-15

259

Beta processes in a high-temperature field and nuclear multibeta decays  

SciTech Connect

Sources of the temperature dependence of rates of nuclear beta processes in matter of massive stars are systematized. Electron and positron beta decays and electron capture (K capture and the capture of unbound electrons) fromexcited nuclear states (thermal decays) are considered along with the photobeta decays from ground and excited nuclear states. The possible quantum degeneracy of an electron gas in matter and the degree of ionization of an atomic K shell in a high-temperature field are taken into account. For a number of multidecay odd-nuclei, the temperature dependences of the ratios of the total rates of their {beta}{sup -} decays to the sum of the total rates over all of decay modes for the same nuclei are calculated in the range of nuclear temperature from 2 to 3 Multiplication-Sign 10{sup 9} K. It is shown that the deviation of this ratio from the experimental value obtained at 'normal' temperature may be quite sizable. This circumstance should be taken into account in models that consider the problem of synthesis of nuclei in matter of massive stars.

Kopytin, I. V., E-mail: kopytin@yandex.ru; Hussain, Imad A. [Voronezh State University (Russian Federation)] [Voronezh State University (Russian Federation)

2013-11-15

260

Early incorporation of cell-derived cholesterol into pre-beta-migrating high-density lipoprotein  

SciTech Connect

Cultures of human skin fibroblasts were labeled to high cholesterol specific activity with (/sup 3/H)cholesterol and incubated briefly (1-3 min) with normal human plasma. The plasma was fractionated by two-dimensional agarose-polyacrylamide gel electrophoresis and the early appearance of cholesterol label among plasma lipoproteins determined. A major part of the label at 1-min incubation was in a pre-beta-migrating apo A-I lipoprotein fraction with a molecular weight of ca. 70,000. Label was enriched about 30-fold in this fraction relative to its content of apo A-I (1-2% of total apo A-I). The proportion of label in this lipoprotein was strongly correlated with its concentration in plasma. Further incubation (2 min) in the presence of unlabeled cells demonstrated transfer of label from this fraction to a higher molecular weight pre-beta apo A-I species, to low-density lipoprotein, and to the alpha-migrating apo A-I that made up the bulk (96%) of total apo A-I in plasma. The data suggest that a significant part of cell-derived cholesterol is transferred specifically to a pre-beta-migrating lipoprotein A-I species as part of a cholesterol transport transfer sequence in plasma.

Castro, G.R.; Fielding, C.J.

1988-01-12

261

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

262

Geographic information system for fusion and analysis of high-resolution remote sensing and ground truth data  

NASA Technical Reports Server (NTRS)

Viewgraphs on Geographic Information System for fusion and analysis of high-resolution remote sensing and ground truth data are presented. Topics covered include: scientific objectives; schedule; and Geographic Information System.

Freeman, Anthony; Dubois, Pascale; Leberl, Franz; Norikane, L.; Way, Jobea

1991-01-01

263

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

264

A high-resolution, multi-parameter, beta-gamma coincidence, mu-gamma anticoincidence system for radioxenon measurement  

Microsoft Academic Search

A high-resolution beta-gamma coincidence measurement system has been developed by combining a high-purity broad energy germanium and a silicon surface barrier detector. The system is intended for calibration of reference spikes and re-measurement of CTBT samples, by detection of coincident beta-gamma or conversion electron and X-ray radiation of the four radioxenon isotopes 131mXe, 133mXe, 133Xe and 135Xe. The use of

T. Schroettner; I. Schraick; T. Furch; P. Kindl

2010-01-01

265

Impaired compensatory beta-cell function and growth in response to high-fat diet in LDL receptor knockout mice.  

PubMed

In this study, we investigated the effect of low density lipoprotein receptor (LDLr) deficiency on gap junctional connexin 36 (Cx36) islet content and on the functional and growth response of pancreatic beta-cells in C57BL/6 mice fed a high-fat (HF) diet. After 60 days on regular or HF diet, the metabolic state and morphometric islet parameters of wild-type (WT) and LDLr-/- mice were assessed. HF diet-fed WT animals became obese and hypercholesterolaemic as well as hyperglycaemic, hyperinsulinaemic, glucose intolerant and insulin resistant, characterizing them as prediabetic. Also they showed a significant decrease in beta-cell secretory response to glucose. Overall, LDLr-/- mice displayed greater susceptibility to HF diet as judged by their marked cholesterolaemia, intolerance to glucose and pronounced decrease in glucose-stimulated insulin secretion. HF diet induced similarly in WT and LDLr-/- mice, a significant decrease in Cx36 beta-cell content as revealed by immunoblotting. Prediabetic WT mice displayed marked increase in beta-cell mass mainly due to beta-cell hypertrophy/replication. Nevertheless, HF diet-fed LDLr-/- mice showed no significant changes in beta-cell mass, but lower islet-duct association (neogenesis) and higher beta-cell apoptosis index were seen as compared to controls. The higher metabolic susceptibility to HF diet of LDLr-/- mice may be explained by a deficiency in insulin secretory response to glucose associated with lack of compensatory beta-cell expansion. PMID:24853046

Oliveira, Ricardo B D; Carvalho, Carolina P D F; Polo, Carla C; Dorighello, Gabriel D G; Boschero, Antônio C; Oliveira, Helena C F D; Collares-Buzato, Carla B

2014-08-01

266

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

267

High-Pressure Tritium Targets for Research in Muon-Catalyzed Fusion  

SciTech Connect

The paper presents designs of a set of high-pressure targets developed by RFNC-VNIIEF and JINR collaboration to study muon-catalyzed fusion at high density of hydrogen isotopes in a wide temperature range. Designs, technical and operating characteristics of the targets and service results are described.In 1997-2002 these targets were used to measure basic characteristics of muon catalysis in pure deuterium, binary D/T mixture and triple H/D/T mixture as a function of density ([variant phi] = 0.2 - 1.2 LHD{sup *}), temperature (T = 20-800 K) and concentration of hydrogen isotopes in a mixture.

Perevozchikov, V.V. [Russian Federal Nuclear Center-All Russian Research Institute of Experimental Physics (Russian Federation); Yukhimchuk, A.A. [Russian Federal Nuclear Center-All Russian Research Institute of Experimental Physics (Russian Federation); Vinogradov, Yu.I. [Russian Federal Nuclear Center-All Russian Research Institute of Experimental Physics (Russian Federation)] (and others)

2005-07-15

268

Repetitively pulsed, high energy KrF lasers for inertial fusion energy  

NASA Astrophysics Data System (ADS)

Krypton fluoride (KrF) lasers produce highly uniform beams at 248 nm, allow the capability of 'zooming' the spot size to follow an imploding pellet, naturally assume a modular architecture and have been developed into a pulsed-power-based industrial technology that readily scales to a fusion power plant sized system. There are two main challenges for the fusion power plant application: to develop a system with an overall efficiency of greater than 6% (based on target gains of 100) and to achieve a durability of greater than 3 × 108 shots (two years at 5 Hz). These two issues are being addressed with the Electra (700 J, 5 Hz) and Nike (3000 J, single shot) KrF lasers at the Naval Research Laboratory. Based on recent advances in pulsed power, electron beam generation and transport, hibachi (foil support structure) design and KrF physics, wall plug efficiencies of greater than 7% should be achievable. Moreover, recent experiments show that it may be possible to realize long lived electron beam diodes using ceramic honeycomb cathodes and anode foils that are convectively cooled by periodically deflecting the laser gas. This paper is a summary of the progress in the development of the critical KrF technologies for laser fusion energy.

Myers, M. C.; Sethian, J. D.; Giuliani, J. L.; Lehmberg, R.; Kepple, P.; Wolford, M. F.; Hegeler, F.; Friedman, M.; Jones, T. C.; Swanekamp, S. B.; Weidenheimer, D.; Rose, D.

2004-12-01

269

Inertial Fusion and High-Energy-Density Science in the United States  

SciTech Connect

Inertial fusion and high-energy density science worldwide is poised to take a great leap forward. In the US, programs at the University of Rochester, Sandia National Laboratories, Los Alamos National Laboratory, Lawrence Livermore National Laboratory (LLNL), the Naval Research Laboratory, and many smaller laboratories have laid the groundwork for building a facility in which fusion ignition can be studied in the laboratory for the first time. The National Ignition Facility (NIF) is being built by the Department of Energy's National Nuclear Security Agency to provide an experimental test bed for the US Stockpile Stewardship Program (SSP) to ensure the dependability of the country's nuclear deterrent without underground nuclear testing. NIF and other large laser systems being planned such as the Laser MegaJoule (LMJ) in France will also make important contributions to basic science, the development of inertial fusion energy, and other scientific and technological endeavors. NIF will be able to produce extreme temperatures and pressures in matter. This will allow simulating astrophysical phenomena (on a tiny scale) and measuring the equation of state of material under conditions that exist in planetary cores.

Tarter, C B

2001-09-06

270

Target design for high fusion yield with the double Z-pinch-driven hohlraum  

SciTech Connect

A key demonstration on the path to inertial fusion energy is the achievement of high fusion yield (hundreds of MJ) and high target gain. Toward this goal, an indirect-drive high-yield inertial confinement fusion (ICF) target involving two Z-pinch x-ray sources heating a central secondary hohlraum is described by Hammer et al. [Phys. Plasmas 6, 2129 (1999)]. In subsequent research at Sandia National Laboratories, theoretical/computational models have been developed and an extensive series of validation experiments have been performed to study hohlraum energetics, capsule coupling, and capsule implosion symmetry for this system. These models have been used to design a high-yield Z-pinch-driven ICF target that incorporates the latest experience in capsule design, hohlraum symmetry control, and x-ray production by Z pinches. An x-ray energy output of 9 MJ per pinch, suitably pulse-shaped, is sufficient for this concept to drive 0.3-0.5 GJ capsules. For the first time, integrated two-dimensional (2D) hohlraum/capsule radiation-hydrodynamics simulations have demonstrated adequate hohlraum coupling, time-dependent radiation symmetry control, and the successful implosion, ignition, and burn of a high-yield capsule in the double Z-pinch hohlraum. An important new feature of this target design is mode-selective symmetry control: the use of burn-through shields offset from the capsule that selectively tune certain low-order asymmetry modes (P{sub 2},P{sub 4}) without significantly perturbing higher-order modes and without a significant energy penalty. This paper will describe the capsule and hohlraum design that have produced 0.4-0.5 GJ yields in 2D simulations, provide a preliminary estimate of the Z-pinch load and accelerator requirements necessary to drive the system, and suggest future directions for target design work.

Vesey, R. A.; Herrmann, M. C.; Lemke, R. W.; Desjarlais, M. P.; Cuneo, M. E.; Stygar, W. A.; Bennett, G. R.; Campbell, R. B.; Christenson, P. J.; Mehlhorn, T. A.; Porter, J. L.; Slutz, S. A. [Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185-1186 (United States)

2007-05-15

271

High current density beamlets from RF Argon source for heavy ion fusion applications  

SciTech Connect

In a new approach to develop high current beams for heavy ion fusion, beam current at about 0.5 ampere per channel can be obtained by merging an array of high current density beamlets of 5 mA each. We have done computer simulations to study the transport of high current density beamlets and the emittance growth due to this merging process. In our RF multicusp source experiment, we have produced a cluster of 61 beamlets using minimum gas flow. The current density from a 0.25 cm diameter aperture reached 100 mA/cm{sup 2}. The normalized emittance of 0.02 {pi}-mm-mrad corresponds to an equivalent ion temperature of 2.4 eV. These results showed that the RF argon plasma source is suitable for producing high current density beamlets that can be merged to form a high current high brightness beam for HIF application.

Kwan, J.W.; Grote, D.P.; Westenskow, G.

2003-08-01

272

Limiter stabilization of high-beta external kink-tearing modes  

SciTech Connect

The stabilizing effects of finite-width poloidal limiters, toroidal limiters, and general mushroom limiters are examined for high-beta finite resistivity tokamak plamas in free boundary. When the plasma pressure and resistivity are small, a poloidal limiter is effective in reducing the growth rate even with a small limiter size, while a toroidal limiter requires a large size for a comparable effect. As the plasma pressure or resistivity increases, a toroidal limiter becomes more effective in reducing the growth rate than a poloidal limiter of the same size. A small optimized mushroom limiter might have a stabilizing effect similar to a conducting shell.

Lee, J.K.; Ohyabu, N.

1984-12-01

273

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

274

Highly mesoporous single-crystalline zeolite beta synthesized using a nonsurfactant cationic polymer as a dual-function template.  

PubMed

Mesoporous zeolites are useful solid catalysts for conversion of bulky molecules because they offer fast mass transfer along with size and shape selectivity. We report here the successful synthesis of mesoporous aluminosilicate zeolite Beta from a commercial cationic polymer that acts as a dual-function template to generate zeolitic micropores and mesopores simultaneously. This is the first demonstration of a single nonsurfactant polymer acting as such a template. Using high-resolution electron microscopy and tomography, we discovered that the resulting material (Beta-MS) has abundant and highly interconnected mesopores. More importantly, we demonstrated using a three-dimensional electron diffraction technique that each Beta-MS particle is a single crystal, whereas most previously reported mesoporous zeolites are comprised of nanosized zeolitic grains with random orientations. The use of nonsurfactant templates is essential to gaining single-crystalline mesoporous zeolites. The single-crystalline nature endows Beta-MS with better hydrothermal stability compared with surfactant-derived mesoporous zeolite Beta. Beta-MS also exhibited remarkably higher catalytic activity than did conventional zeolite Beta in acid-catalyzed reactions involving large molecules. PMID:24450997

Zhu, Jie; Zhu, Yihan; Zhu, Liangkui; Rigutto, Marcello; van der Made, Alexander; Yang, Chengguang; Pan, Shuxiang; Wang, Liang; Zhu, Longfeng; Jin, Yinying; Sun, Qi; Wu, Qinming; Meng, Xiangju; Zhang, Daliang; Han, Yu; Li, Jixue; Chu, Yueying; Zheng, Anmin; Qiu, Shilun; Zheng, Xiaoming; Xiao, Feng-Shou

2014-02-12

275

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

276

High thermal conductivity of graphite fiber silicon carbide composites for fusion reactor application  

NASA Astrophysics Data System (ADS)

The benefits of using CVI SiC/graphite fiber composites as low tritium retaining, high thermal conductivity composites for fusion applications are presented. Three-dimensional woven composites have been chemically vapor infiltrated with SiC and their thermophysical properties measured. One material used an intermediate grade graphite fiber in all directions (Amoco P55) while a second material used very high thermal conductive fiber (Amoco K-1100) in the high fiber density direction. The overall void was less than 20%. Strength as measured by four-point bending was comparable to those of SiC/SiC composite. The room temperature thermal conductivity in the high conductivity direction was impressive for both materials, with values >70 W/m K for the P-55 and >420 W/m K for the K-1100 variant. The thermal conductivity was measured as a function of temperature and exceeds the highest thermal conductivity of CVD SiC currently available at fusion relevant temperatures (>600 °C). Limited data on the irradiation-induced degradation in thermal conductivity is consistent with carbon fiber composite literature.

Snead, L. L.; Balden, M.; Causey, R. A.; Atsumi, H.

2002-12-01

277

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

278

Target design for high fusion yield with the double Z-pinch-driven hohlraum.  

NASA Astrophysics Data System (ADS)

A key demonstration on the path to inertial fusion energy is the achievement of high fusion yield (hundreds of MJ) and high target gain. An indirect-drive high-yield inertial confinement fusion (ICF) target involving two z-pinch x-ray sources heating a central secondary hohlraum is described by Hammer, Tabak, Wilks, et al. [Phys. Plasmas 6, 2129 (1999)]. In subsequent research at Sandia National Laboratories, we have developed theoretical/computational models and performed an extensive series of validation experiments to study hohlraum energetics, capsule coupling, and capsule implosion symmetry. We are using these models to design a 0.5 GJ yield z-pinch-driven ICF target that incorporates the latest experience in capsule design, hohlraum symmetry control, and x-ray production by z-pinches. An x-ray energy output of 8-9 MJ per pinch, suitably pulse-shaped, is sufficient for this concept to drive 0.3-0.5 GJ capsules. Integrated 2D hohlraum/capsule LASNEX radiation-hydrodynamics simulations have demonstrated adequate hohlraum coupling, radiation symmetry control, and the successful implosion, ignition and burn of a 0.5 GJ ICF capsule. An important new feature of this target design is mode-selective symmetry control: the use of burnthrough shields offset from the capsule that selectively tune certain low-order asymmetry modes (P2, P4) without significantly perturbing higher-order modes. This talk will describe the capsule and hohlraum design that have produced 0.5 GJ yields in 2D simulations, as well as provide a preliminary design of the z-pinch load and accelerator requirements necessary to drive the system. In collaboration with M. C. Herrmann, R. W. Lemke, G. R. Bennett, R. B. Campbell, P. J. Christenson, M. E. Cuneo, M. P. Desjarlais, T. A. Mehlhorn, J. L. Porter, D. B. Sinars, S. A. Slutz, W. A. Stygar, E. P. Yu, and J. H. Hammer (LLNL).

Vesey, Roger

2006-10-01

279

Comparison of nuclear irradiation parameters of fusion breeder materials in high flux fission test reactors and a fusion power demonstration reactor  

Microsoft Academic Search

Nuclear irradiation parameters relevant to displacement damage and burn-up of the breeder materials Li2O, Li4SiO4 and Li2TiO3 have been evaluated and compared for a fusion power demonstration reactor and the high flux fission test reactor (HFR), Petten, the advanced test reactor (ATR, INEL) and the Japanese material test reactor (JMTR, JAERI). Based on detailed nuclear reactor calculations with the MCNP

U. Fischer; S. Herring; A. Hogenbirk; D. Leichtle; Y. Nagao; B. J. Pijlgroms; A. Ying

2000-01-01

280

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.

Weiner, Alan M.; Gray, Lucas T.

2013-01-01

281

IEFIT - An Interactive Approach to High Temperature Fusion Plasma Magnetic Equilibrium Fitting  

SciTech Connect

An interactive IDL based wrapper, IEFIT, has been created for the magnetic equilibrium reconstruction code EFIT written in FORTRAN. It allows high temperature fusion physicists to rapidly optimize a plasma equilibrium reconstruction by eliminating the unnecessarily repeated initialization in the conventional approach along with the immediate display of the fitting results of each input variation. It uses a new IDL based graphics package, GaPlotObj, developed in cooperation with Fanning Software Consulting, that provides a unified interface with great flexibility in presenting and analyzing scientific data. The overall interactivity reduces the process to minutes from the usual hours.

Peng, Q.; Schachter, J.; Schissel, D.P.; Lao, L.L.

1999-06-01

282

A NEW HIGH RELIABILITY AND DUAL MEASURE METHOD FOR MULTISYSTEM\\/SENSOR REMOTE-SENSING DECISION FUSION  

Microsoft Academic Search

In this paper we will introduce a new high reliability multi-system\\/sensor decision fusion scheme based on dual measure calculations and formulations. The data are collected from remote sensing of the ground targets in different spectral bands including visible, near infrared (NIR), IR, thermal, and microwave by multi-system\\/sensor systems. At first, we will review the decision fusion methods such as voting

Ali J. Rashidi; M. Hassan Ghassemian

283

Symmetric inertial confinement fusion capsule implosions in a high-yield-scale double-Z-pinch-driven hohlraum on Z  

Microsoft Academic Search

Detailed radiation-hydrodynamics calculations indicate that the dual-63-MA Z-pinch high-yield (HY) 220-eV inertial confinement fusion concept [Phys. Plasmas 6, 2129 (1999)] may release 400 MJ of fusion yield, if pulse shaping, capsule preheat, and x-radiation drive uniformity can be acceptably controlled. Radiation symmetry is under detailed investigation in an advanced, 70-eV HY-scale scoping hohlraum [Phys. Rev. Lett. 88, 215004 (2002)] driven

G. R. Bennett; R. A. Vesey; M. E. Cuneo; J. L. Porter; R. G. Adams; R. A. Aragon; P. K. Rambo; D. C. Rovang; L. E. Ruggles; W. W. Simpson; I. C. Smith; C. S. Speas; K. W. Struve; D. F. Wenger; O. L. Landen

2003-01-01

284

Non-inductive current drive and transport in high beta(N) plasmas in JET  

SciTech Connect

A route to stationary MHD stable operation at high beta(N) has been explored at the Joint European Torus (JET) by optimizing the current ramp-up, heating start time and the waveform of neutral beam injection (NBI) power. In these scenarios the current ramp-up has been accompanied by plasma pre-heat (or the NBI has been started before the current flat-top) and NBI power up to 22 MW has been applied during the current flat-top. In the discharges considered transient total beta(N) approximate to 3.3 and stationary (during high power phase) beta(N) approximate to 3 have been achieved by applying the feedback control of beta(N) with the NBI power in configurations with monotonic or flat core safety factor profile and without an internal transport barrier (ITB). The transport and current drive in this scenario is analysed here by using the TRANSP and ASTRA codes. The interpretative analysis performed with TRANSP shows that 50-70% of current is driven non-inductively; half of this current is due to the bootstrap current which has a broad profile since an ITB was deliberately avoided. The GLF23 transport model predicts the temperature profiles within a +/- 22% discrepancy with the measurements over the explored parameter space. Predictive simulations with this model show that the E x B rotational shear plays an important role for thermal ion transport in this scenario, producing up to a 40% increase of the ion temperature. By applying transport and current drive models validated in self-consistent simulations of given reference scenarios in a wider parameter space, the requirements for fully non-inductive stationary operation at JET are estimated. It is shown that the strong stiffness of the temperature profiles predicted by the GLF23 model restricts the bootstrap current at larger heating power. In this situation full non-inductive operation without an ITB can be rather expensive strongly relying on the external non-inductive current drive sources.

Voitsekhovitch, I [UKAEA Fusion, Culham UK; Alper, B. [EURATOM / UKAEA, UK; Brix, M [UKAEA Fusion, Culham UK; Budny, R. V. [Princeton Plasma Physics Laboratory (PPPL); Buratti, P. [ENEA, Frascati; Challis, C D [UKAEA Fusion, Culham UK; Ferron, J.R. [General Atomics, San Diego; Giroud, C. [EURATOM / UKAEA, UK; Joffrin, E. [CEA Cadarache, St. Paul lex Durance, France; Laborde, L. [UKAEA Fusion, Culham UK; Luce, T.C. [General Atomics, San Diego; McCune, D. [Princeton Plasma Physics Laboratory (PPPL); Menard, J. [Princeton Plasma Physics Laboratory (PPPL); Murakami, Masanori [ORNL; Park, Jin Myung [ORNL

2009-01-01

285

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

286

(-)(125I)-iodopindolol, a new highly selective radioiodinated beta-adrenergic receptor antagonist: measurement of beta-receptors on intact rat astrocytoma cells  

SciTech Connect

(-)-Pindolol, one of the most potent beta-adrenergic receptor antagonists, was radioiodinated using chloramine-T oxidation of carrier-free Na 125I and separated from unreacted pindolol to yield 2200 Ci/mmole (-)-(125I)-iodopindolol ((-)-(125I)-IPin). Mass and ultraviolet spectra confirmed that the iodination occurred on the indole ring, presumably at the 3 position. The binding of radiolabeled (-)-(125I)-IPin to beta-adrenergic receptors has been studied using intact C6 rat astrocytoma cells (2B subclone) grown in monolayer cultures. Binding of (-)(125IPin was saturable with time and concentration. Using 13 pM (-)-(125I)IPin, binding equilibrium was reached in 90 min at 21-22 degrees C. The reverse rate constant was 0.026 min-1 at 21/sup 0/C. Specific binding (expressed as 1 microM(-)-propranolol displaceable counts) of (-)-(125I)-IPin was 95% of total binding. Scatchard analysis of (-)-(125I)-I)Pin binding revealed approximately 4300 receptors/cell and a dissociation constant of 30 pM. This was in excellent agreement with the kinetically determined dissociation constant of 35 pM. Displacement by propranolol and isoproterenol showed that (-)-(125I)-IPin binding sites were pharmacologically and stereospecifically selective. These results indicate that (-)-(125I)-IPin, a pure (-)-stereoisomer, high specific activity radioligand, selectively binds to beta-adrenergic receptors in whole cells with a high percentage of specific binding and should therefore be useful in the study and measurement of cellular beta-adrenergic receptors.

Barovsky, K.; Brooker, G.

1980-01-01

287

KrF laser path to high gain ICF (inertial confinement fusion) laboratory microfusion facility  

SciTech Connect

The krypton-fluoride laser has many desirable features for inertial confinement fusion. Because it is a gas laser capable of operation with high efficiency, it is the only known laser candidate capable of meeting the driver requirements for inertial fusion energy (IFE) production. Los Alamos National Laboratory has defined a program plan to develop KrF lasers for IFE production. This plan develops the KrF laser and demonstrates the target performance in single-pulse facilities. A 100-kJ Laser Target Test Facility (LTTF) is proposed as the next step, to be followed by a 3 to 10-MJ Laboratory Microfusion Facility (LMF). The LTTF will resolve many target physics issues and accurately define the driver energy required for the LMF. It is also proposed that the technology development for IFE, such as the high-efficiency, high-reliability, repetitively pulsed driver, the reactor, mass production of targets, and the mechanism of injecting targets be developed in parallel with the single-pulse facilities. 11 refs., 4 figs.

Harris, D.B.; Sullivan, J.A.; Figueiro, J.F.; Cartwright, D.C.; McDonald, T.E.; Hauer, A.A.; Coggeshall, S.V.; Younger, S.M.

1990-01-01

288

Very high-level production and export in Escherichia coli of a cellulose binding domain for use in a generic secretion-affinity fusion system.  

PubMed

A novel expression vector pTugA, previously constructed in our laboratory, was modified to provide kanamycin resistance (pTugK) and used to direct the synthesis of polypeptides as fusions with the C- or N-terminus of a cellulose binding domain which serves as the affinity tag in a novel secretion-affinity fusion system. Fed-batch fermentation strategies were applied to production in recombinant E. coli TOPP5 of the cellulose binding domain (CBD) from the Cellulomonas fimi cellulase Cex. The pTugK expression vector, which codes for the Cex leader sequence that directs the recombinant protein to the periplasm of E. coli, was shown to remain stable at very high-cell densities. Recombinant cell densities in excess of 90 g (dry cell weight)/L were achieved using media and feed solutions optimized using a 2(n) factorial design. Optimization of inducer (isophenyl-thio-beta-D-galactopyranoside) concentration and the time of induction led to soluble, fully active CBD(Cex) production levels in excess of 8 g/L. PMID:18636596

Hasenwinkle, D; Jervis, E; Kops, O; Liu, C; Lesnicki, G; Haynes, C A; Kilburn, D G

1997-09-20

289

Low- and high-density lipoproteins modulate function, apoptosis, and proliferation of primary human and murine pancreatic beta-cells.  

PubMed

A low high-density lipoprotein (HDL) plasma concentration and the abundance of small dense low-density lipoproteins (LDL) are risk factors for developing type 2 diabetes. We therefore investigated whether HDL and LDL play a role in the regulation of pancreatic islet cell apoptosis, proliferation, and secretory function. Isolated mouse and human islets were exposed to plasma lipoproteins of healthy human donors. In murine and human beta-cells, LDL decreased both proliferation and maximal glucose-stimulated insulin secretion. The comparative analysis of beta-cells from wild-type and LDL receptor-deficient mice revealed that the inhibitory effect of LDL on insulin secretion but not proliferation requires the LDL receptor. HDL was found to modulate the survival of both human and murine islets by decreasing basal as well as IL-1beta and glucose-induced apoptosis. IL-1beta-induced beta-cell apoptosis was also inhibited in the presence of either the delipidated protein or the deproteinated lipid moieties of HDL, apolipoprotein A1 (the main protein component of HDL), or sphingosine-1-phosphate (a bioactive sphingolipid mostly carried by HDL). In murine beta-cells, the protective effect of HDL against IL-1beta-induced apoptosis was also observed in the absence of the HDL receptor scavenger receptor class B type 1. Our data show that both LDL and HDL affect function or survival of beta-cells and raise the question whether dyslipidemia contributes to beta-cell failure and hence the manifestation and progression of type 2 diabetes mellitus. PMID:19628574

Rütti, Sabine; Ehses, Jan A; Sibler, Rahel A; Prazak, Richard; Rohrer, Lucia; Georgopoulos, Spiros; Meier, Daniel T; Niclauss, Nadja; Berney, Thierry; Donath, Marc Y; von Eckardstein, Arnold

2009-10-01

290

Magnetospheres in the Labtoratory: Studying the Role of Ion Temperature Anisotropy in High Beta Plasmas  

NASA Astrophysics Data System (ADS)

The wide range of plasma regimes in the near-Earth space environment provide unparalleled opportunities for testing the predictions of theory and computation. Measurements and theory have yielded substantial insight into the macroscopic dynamics and structure of the terrestrial ionosphere, magnetosphere, and magnetotail, as well as of the solar wind. Unfortunately, nature's price for providing such a rich plasma environment is that the scientific paradigm of varying a single parameter in a controlled experiment and determining the consequences is extremely difficult to achieve in space plasma research. Thus, progress in understanding microscopic aspects of space plasmas has been more equivocal. This talk will focus on studies of electromagnetic ion temperature anisotropy driven instabilities in high beta, marginally collisional, magnetized plasmas. The experiments were performed in the West Virginia University Large Experiment on Anisotropies and Instabilities (LEIA). Typical steady state, LEIA argon plasma parameters are n ~ 10E12 cm-3, B ~ 40 G, electron temperature ~ 5 eV, parallel ion temperature ~ 0.2 eV, perpendicular ion temperature ~ 0.6 eV, electron beta ~ 0.1 , and parallel ion beta ~ 0.01. The parallel and perpendicular ion temperatures are determined by laser induced fluorescence. Radially resolved, two dimensional(parallel and perpendicular to the field) measurements of the ion distribution function are also routinely measured. Ion temperatures anisotropies (perpendicular over parallel) ranging from 1 to 20 have been observed and the upper bound on the anisotropy is observed to be inversely correlated with parallel ion beta as predicted by theory and computation. The inverse scaling of the upper bound on the ion temperature anisotropy is also consistent with magnetosheath observations by multiple spacecraft. Magnetic fluctuation measurements support the conclusion that anisotropy driven, electromagnetic instabilities exist in the plasma and that they play a role in limiting the ion temperature anisotropy. The experimental results also suggest that such constraints may be a fundamental property of all collisionless plasmas bearing such an anisotropy, including other laboratory plasmas as well as space and astrophysical domains not yet subject to in situ observations. Thus, the basic concept of short wavelength instabilities imposing anisotropy constraints may offer an alternative to the long-standing approach of using analogues of collision-dominated transport coefficients to express the consequences of small-scale, collective processes in the collisionless plasmas of space. This work supported by the National Science Foundation under grant ATM-9616467 and the U.S. Department of Energy under grant DE-FG02-97ER54420

Scime, Earl

1999-11-01

291

Design and material issues for high performance SiC f\\/SiC-based fusion power cores  

Microsoft Academic Search

The SiCf\\/SiC composite is a promising structural material candidate for fusion power cores and has been considered internationally in several power plant studies. It offers safety advantages arising from its low induced radioactivity and afterheat, and the possibility of high performance through high temperature operation. However, its behavior and performance at high temperatures and under irradiation are still not well

A. R. Raffray; R. Jones; G. Aiello; M. Billone; L. Giancarli; H. Golfier; A. Hasegawa; Y. Katoh; A. Kohyama; S. Nishio; B. Riccardi; M. S. Tillack

2001-01-01

292

On the repassivation behavior of high-purity titanium and selected {alpha}, {beta}, and {beta} + {alpha} titanium alloys in aqueous chloride solutions  

SciTech Connect

The repassivation characteristics of a titanium thin film evaporated from a high-purity Ti source as well as selected {alpha} (commercially pure Ti, Ti-5Al-2.5Sn), {beta}, and {beta} + {alpha} titanium alloys (Ti-15Mo-3Nb-3Al, Ti-15V-3Cr-3Al-3Sn, and Ti-3Al-8V-6Cr-4Zr-4Mo) were examined. Both the rapid thin film fracture and scratch depassivation methods were used in aqueous chloride solutions (0.6 M NaCl, 5 M HCl, 5 M LiCl, 5 M HCl + 1 M TiCl{sub 3}). Oxide formation after depassivation was of low overall current efficiency on all titanium materials; a large percentage of the anodic charge following depassivation contributed to dissolution. Consequently, an empirical expression was used to describe the anodic current density decay during repassivation; i = i{sub o}(t/t{sub o}){sup {minus}m}. Potentiostatic current transients on rapidly fractured thin film Ti produced plateau bare-metal i{sub o} values greater than 100 A/cm{sup 2} which were below the theoretical ohmic limit, m = 2.0 to 1.4 depending on solution and potential and t{sub o} values from 20 to 30 {micro}s. Two anodic Tafel regions and a single cathodic region best described IR-corrected E {minus} log i relationships for bare Ti in all electrolytes. LiCl and TiCl{sub 3} inhibited bare surface dissolution but slightly delayed current density decay. Minimal differences between any of the repassivation parameters utilized were observed for selected {alpha}, {beta}, and {beta} + {alpha} titanium alloys. The similarity was attributed to dominance of Ti{sup +3} production in the total anodic charge during repassivation and predominantly TiO{sub 2} formation in the passivating oxides of all alloys.

Kolman, D.G. [Univ. of Virginia, Charlottesville, VA (United States). Center for Electrochemical Science and Engineering]|[Los Alamos National Labs., NM (United States); Scully, J.R. [Univ. of Virginia, Charlottesville, VA (United States). Center for Electrochemical Science and Engineering

1996-06-01

293

Synthesis of poly(beta-amino ester)s optimized for highly effective gene delivery.  

PubMed

Several families of synthetic polymers, including degradable poly(beta-amino ester)s, have been previously shown to effectively mediate gene transfer. However, the combined impact of potentially significant factors-such as polymer molecular weight, polymer chain end-group, and polymer/DNA ratio-on different gene transfer properties has yet to be systematically investigated. The elucidation of these relationships may aid in the design of nonviral vectors with greatly enhanced transfection properties. To examine these factors, two distinct poly(beta-amino ester) structures, Poly-1 and Poly-2, were generated by adding 1,4-butanediol diacrylate and 1,6-hexanediol diacrylate, respectively, to 1-aminobutanol. Twelve unique versions of each structure were synthesized by varying amine/diacrylate stoichiometric ratios, resulting in polymers with either amine or acrylate end-groups and with molecular weights ranging from 3350 to 18000. Using high throughput methods, all polymers were tested in quadruplicate at nine different polymer/DNA ratios ranging from 10:1 w/w to 150:1 w/w. Through the optimization of molecular weight, polymer chain end-group, and polymer/DNA ratio, these polymers successfully mediated gene transfer at levels that surpassed both PEI and Lipofectamine 2000 in vitro. PMID:13129402

Akinc, Akin; Anderson, Daniel G; Lynn, David M; Langer, Robert

2003-01-01

294

Beta-adrenoceptor activation shows high-frequency fatigue in skeletal muscle fibers of the rat.  

PubMed

The effect of terbutaline (a beta 2-adrenergic agonist) on high-frequency fatigue (HFF) was studied in small bundles of rat soleus muscle fibers. HFF, the decline in force during continuous stimulation (50 Hz for 20 s), was reduced by 10-20% with 10 microM terbutaline. A similar reduction in HFF with 2 mM dibutyryl-adenosine 3',5'-cyclic monophosphate (DBcAMP) implicated adenosine 3',5'-cyclic monophosphate (cAMP) as the second messenger in the terbutaline effect. Sodium (Na-K)-pump inhibition with 1 mM ouabain depressed peak tetanic force but did not significantly alter either the subsequent fatigue or the effect of terbutaline on fatigue. This suggested that the pump was neither rate limiting in HFF nor involved in the terbutaline effect. Nevertheless, a significant hyperpolarization recorded with terbutaline implied that beta 2-adrenoceptor activation stimulated the Na-K pump at rest. Caffeine (1 mM) slowed HFF and prevented additional effects with terbutaline. Caffeine is known to potentiate Ca2+ release from the sarcoplasmic reticulum (SR), and we suggest that terbutaline, acting via cAMP, facilitates Ca2+ release from the SR to better maintain myoplasmic Ca2+ concentration during continuous tetanic stimulation. PMID:8203484

Cairns, S P; Dulhunty, A F

1994-05-01

295

a New Method to Explore High-Spin States by RI Beam Induced Fusion Reaction  

NASA Astrophysics Data System (ADS)

A new ?-ray spectroscopy method was developed using low-energy (around 5-10 MeV/u) RI beam induced fusion reaction, which enables us to study high-spin states of nuclei in wider mass region where high-spin states could not be produced by the combination of the stable beam and stable target. The low-energy 17N RI beam was produced by the direct reaction using low-energy primary beam and was transported up to the secondary target using the EN beam line at RCNP, Osaka University. Two experiments were performed to investigate the high-spin states in 142Pr (N=83 isotone) and in 136Ba (N=80 isotone) by this new ?-ray spectroscopy method using the low-energy 17N RI beam.

Odahara, A.; Shimoda, T.; Ito, Y.; Nishibata, H.; Tajiri, K.; Takatsu, J.; Hamatani, N.; Yokoyama, R.; Petrache, C.; Leguillon, R.; Suzuki, T.; Ideguchi, E.; Watanabe, H.; Wakabayashi, Y.; Yoshinaga, K.; Beaumel, D.; Desesquelles, P.; Curien, D.; Guinet, D.; Lehaut, G.

2013-09-01

296

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

297

Electron temperature profiles in high power neutral-beam-heated TFTR (Tokamak Fusion Test Reactor) plasmas  

SciTech Connect

In 1986, the maximum neutral beam injection (NBI) power in the Tokamak Fusion Test Reactor (TFTR) was increased to 20 MW, with three beams co-parallel and one counter-parallel to I/sub p/. TFTR was operated over a wide range of plasma parameters; 2.5 < q/sub cyl/ < 10, and 2 x 10/sup 19/ < anti n/sub e/ < 7 x 10/sup 19/ m/sup -3/. Data bases have been constructed with over 600 measured electron temperature profiles from multipoint TV Thomson scattering which span much of this parameter space. We have also examined electron temperature profile shapes from electron cyclotron emission at the fundamental ordinary mode and second harmonic extraordinary mode for a subset of these discharges. In the light of recent work on ''profile consistency'' we have analyzed these temperature profiles in the range 0.3 < (r/a) < 0.9 to determine if a profile shape exists which is insensitive to q/sub cyl/ and beam-heating profile. Data from both sides of the temperature profile (T/sub e/(R)) were mapped to magnetic flux surfaces (T/sub e/(r/a)). Although T/sub e/(r/a), in the region where 0.3 < r/a < 0.9 was found to be slightly broader at lower q/sub cyl/, it was found to be remarkably insensitive to ..beta../sub p/, to the fraction of NBI power injected co-parallel to I/sub p/, and to the heating profile going from peaked on axis, to hollow. 10 refs., 8 figs.

Taylor, G.; Grek, B.; Stauffer, F.J.; Goldston, R.J.; Fredrickson, E.D.; Wieland, R.M.; Zarnstorff, M.C.

1987-09-01

298

Advances in Tandem Mirror fusion power reactors  

Microsoft Academic Search

The Tandem Mirror exhibits several distinctive features which make the reactor embodiment of the principle very attractive: Simple low-technology linear central cell; steady-state operation; high-..beta.. operation; no driven current or disruptions; divertorless operation; direction conversion of end-loss power; low-surface heat loads; and advanced fusion fuel capability. In this paper, we examine these features in connection with two tandem mirror reactor

L. J. Perkins; B. G. Logan

1986-01-01

299

Separation of stereoisomers of some terpene derivatives by capillary gas chromatography-mass spectrometry and high-performance liquid chromatography using beta-cyclodextrin derivative columns.  

PubMed

Gas chromatographic separations of the stereoisomers of menthol derivatives, important intermediates in the synthesis of physiologically active natural products, were carried out on several substituted beta-cyclodextrin (CD) columns, including per-O-methyl-beta-cyclodextrin (PME-beta-CD), heptakis(2,3-di-O-acetyl-6-tert-butyldimethylsilyl)-beta-CD (DIAC-6-TBDS-beta-CD), and heptakis(2,3-di-O-methyl-6-tert-butyldimethylsilyl)-beta-CD (DIME-6-TBDS-beta-CD) as chiral stationary phases (CSPs). With the DIME-6-TBDS-beta-CD column, a separation of the Z- and E-isomers of methylidenementhol was accomplished; no separation was achieved with the other columns. The stereoisomers of methylidenementhol and the corresponding tert-butyldimethylsilyl (TBS) ether were separated on both the beta-CD and the heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin (TME-beta-CD) columns by high-performance liquid chromatography (HPLC) with a mobile phase involving acetonitrile and H(2)O. For the separation of the Z- and E-isomers of methylidenementhol, the TME-beta-CD column was superior. In contrast, the beta-CD column was preferable in the case of the corresponding TBS ether. PMID:14993753

Kasai, Hiroko F; Tsubuki, Masayoshi; Matsumoto, Yohichiro; Shirao, Mika; Takahashi, Kazunori; Honda, Toshio; Ueda, Haruhisa

2004-03-01

300

Comparison of nuclear irradiation parameters of fusion breeder materials in high flux fission test reactors and a fusion power demonstration reactor  

NASA Astrophysics Data System (ADS)

Nuclear irradiation parameters relevant to displacement damage and burn-up of the breeder materials Li 2O, Li 4SiO 4 and Li 2TiO 3 have been evaluated and compared for a fusion power demonstration reactor and the high flux fission test reactor (HFR), Petten, the advanced test reactor (ATR, INEL) and the Japanese material test reactor (JMTR, JAERI). Based on detailed nuclear reactor calculations with the MCNP Monte Carlo code and binary collision approximation (BCA) computer simulations of the displacement damage in the polyatomic lattices with MARLOWE, it has been investigated how well the considered HFRs can meet the requirements for a fusion power reactor relevant irradiation. It is shown that a breeder material irradiation in these fission test reactors is well suited in this regard when the neutron spectrum is well tailored and the 6Li-enrichment is properly chosen. Requirements for the relevant nuclear irradiation parameters such as the displacement damage accumulation, the lithium burn-up and the damage production function W( T) can be met when taking into account these prerequisites. Irradiation times in the order of 2-3 full power years are necessary for the HFR to achieve the peak values of the considered fusion power Demo reactor blanket with regard to the burn-up and, at the same time, the dpa accumulation.

Fischer, U.; Herring, S.; Hogenbirk, A.; Leichtle, D.; Nagao, Y.; Pijlgroms, B. J.; Ying, A.

2000-07-01

301

Spinal fusion  

MedlinePLUS

Vertebral interbody fusion; Posterior spinal fusion; Arthrodesis; Anterior spinal fusion; Spine surgery - spinal fusion ... Spinal fusion is most often done along with other surgical procedures of the spine. It may be done: With ...

302

In vitro killing of parenteral beta-lactams against standard and high inocula of extended-spectrum beta-lactamase and non-esbl producing klebsiella pneumoniae  

Microsoft Academic Search

Minimum inhibitory concentrations and time-kill curves were performed against 8 Klebsiella pneumoniae (4 non-extended-spectrum beta-lactamase[ESBL] and 4 ESBL) for piperacillin\\/tazobactam (40\\/5 ?g\\/mL), cefepime (20 ?g\\/mL), and meropenem (4 ?g\\/mL) by using a standard and high inocula. Imipenem was evaluated only at the standard inoculum for the non-ESBL and ESBL isolates. Samples were withdrawn at 7 predetermined time-points over 24 hours

David S Burgess; Ronald G Hall

2004-01-01

303

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

304

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

305

HYFIRE II: fusion/high-temperature electrolysis conceptual-design study. Annual report  

SciTech Connect

As in the previous HYFIRE design study, the current study focuses on coupling a Tokamak fusion reactor with a high-temperature blanket to a High-Temperature Electrolyzer (HTE) process to produce hydrogen and oxygen. Scaling of the STARFIRE reactor to allow a blanket power to 6000 MW(th) is also assumed. The primary difference between the two studies is the maximum inlet steam temperature to the electrolyzer. This temperature is decreased from approx. 1300/sup 0/ to approx. 1150/sup 0/C, which is closer to the maximum projected temperature of the Westinghouse fuel cell design. The process flow conditions change but the basic design philosophy and approaches to process design remain the same as before. Westinghouse assisted in the study in the areas of systems design integration, plasma engineering, balance-of-plant design, and electrolyzer technology.

Fillo, J.A. (ed.)

1983-08-01

306

Potential for use of high-temperature superconductors in fusion reactors  

SciTech Connect

The present rate of development of high-temperature superconductors (HTSs) is sufficiently rapid that there may be opportunities for their use in contemporary fusion devices such as the International Thermonuclear Experimental Reactor (ITER). The most likely 1application is for delivering power to the superconducting magnets, especially in substituting for the current leads between the temperatures of 4 K and 77K. A second possible application of HTSs is as a liquid-nitrogen-cooled power bus, connecting the power supplies to the magnets, thus reducing the ohmic heating losses over these relatively long cables. A third potential application of HTSs is as an inner high-field winding of the toroidal field coils that would operate at {approx}20 K. While the use of higher temperature magnets offers significant advantages to the reactor system, it is unlikely that tested conductors of this type will be available within the ITER time frame. 23 refs., 2 figs.

Hull, J.R.

1991-01-01

307

High Brønsted beta nuc values in SNAr displacement. An indicator of the SET pathway?  

PubMed

Nucleophilic substitutions of 4-chloro-7-nitrobenzofurazan (NBD-Cl) and 3-methyl-1-(4-nitrobenzofurazanyl)-imidazolium ions (NBD-Im+) with a series of 4-X-substituted anilines have been kinetically investigated in 70-30 (v/v) and 20-80 (v/v) H2O-Me2SO mixtures. The rate-limiting step in these reactions is nucleophilic addition with formation of Meisenheimer-type sigma-adducts followed by fast expulsion of the leaving group (Cl- or Im). The reactions are characterized by a notable sensitivity to basicity of the aniline nucleophiles, with Hammett rho values of -2.68 and -3.82 in 30% and 80% Me2SO, respectively, for NBD-Cl and even more negative values, -3.43 and -5.27, respectively, for NBD-Im+. This is consistent with significant development of positive charge at the nitrogen atom of the zwitterionic sigma-adduct. Unexpectedly, the Brønsted-type plots reveal abnormally high beta nuc values, ca. 1.0 and 1.3-1.4, respectively. Satisfactory correlations between the rates of the reactions and the oxidation potentials of the respective anilines support a SET mechanism for this process, i.e. initial (fast) electron-transfer from the aniline donor to the nitrobenzofurazan acceptor moiety and subsequent (slow) coupling of the resulting cation and anion radicals within the solvent cage with formation of the sigma-adduct. An alternative possible explanation of the high beta nuc values being related to the strong--I effect exerted by the negatively charged 4-nitrobenzofurazanyl structure, which would induce a greater positive charge at the developing anilinium nitrogen atom in the sigma-adduct-like transition state as compared with the situation in the reference protonation equilibria of anilines, is considered less probable. It is thus proposed that obtention of abnormal beta nuc values may be an indicator of electron-transfer in nucleophilic aromatic substitution and highlights the transition from the polar (SNAr) to the single electron-transfer (SET) mechanism. PMID:12926366

Terrier, François; Mokhtari, Malika; Goumont, Régis; Hallé, Jean-Claude; Buncel, Erwin

2003-05-21

308

Fast magnetization of a high-to-low-beta plasma beam  

NASA Technical Reports Server (NTRS)

The magnetization of a high-beta (plasma energy density/magnetic-field energy density) hydrogen-plasma beam injected into a vacuum transverse magnetic field is studied experimentally. Nominal parameters were Ti = 1 eV, Te = 5 eV, n = 3 x 10 to the 13th/cu cm or less, v(i) = 7 x 10 to the 6th cm/sec or less, t(pulse) less than 70 microsec, and Bz = 300 G or less. Plasma characteristics were measured for a wide beam and a downstream distance, x = 300 rho(i) or less, where x is the downstream distance and rho(i) is the ion gyroradius. A brief initial state of diamagnetic propagation is observed, followed by magnetized propagation accompanied by beam compression transverse to B with as much as a factor of 4 increase in density and a slight drift of the beam in the ion Lorentz force direction.

Song, J. J.; Wessel, F. J.; Yur, G.; Rahman, H. U; Rostoker, N.

1990-01-01

309

High dose insulin therapy, an evidence based approach to beta blocker/calcium channel blocker toxicity.  

PubMed

Poison-induced cardiogenic shock (PICS) as a result of beta-blocker (?-blocker) or calcium channel blocker (CCB) overdose is a common and potentially life-threatening condition. Conventional therapies, including fluid resuscitation, atropine, cardiac pacing, calcium, glucagon, and vasopressors often fail to improve hemodynamic status. High-dose insulin (HDI) is an emerging therapeutic modality for PICS. In this article, we discuss the existing literature and highlight the therapeutic success and potential of HDI. Based on the current literature, which is limited primarily to case series and animal models, the authors conclude that HDI can be effective in restoring hemodynamic stability, and recommend considering its use in patients with PICS that is not responsive to traditional therapies. Future studies should be undertaken to determine the optimal dose and duration of therapy for HDI in PICS. PMID:24713415

Woodward, Christina; Pourmand, Ali; Mazer-Amirshahi, Maryann

2014-01-01

310

High dose insulin therapy, an evidence based approach to beta blocker/calcium channel blocker toxicity  

PubMed Central

Poison-induced cardiogenic shock (PICS) as a result of beta-blocker (?-blocker) or calcium channel blocker (CCB) overdose is a common and potentially life-threatening condition. Conventional therapies, including fluid resuscitation, atropine, cardiac pacing, calcium, glucagon, and vasopressors often fail to improve hemodynamic status. High-dose insulin (HDI) is an emerging therapeutic modality for PICS. In this article, we discuss the existing literature and highlight the therapeutic success and potential of HDI. Based on the current literature, which is limited primarily to case series and animal models, the authors conclude that HDI can be effective in restoring hemodynamic stability, and recommend considering its use in patients with PICS that is not responsive to traditional therapies. Future studies should be undertaken to determine the optimal dose and duration of therapy for HDI in PICS.

2014-01-01

311

High precision measurement of the superallowed 0+ --> 0+ beta decay of 22Mg.  

PubMed

The half-life, 3.8755(12) s, and superallowed branching ratio, 0.5315(12), for 22Mg beta decay have been measured with high precision. The latter depended on gamma-ray intensities being measured with an HPGe detector calibrated for relative efficiencies to an unprecedented 0.15%. Previous precise measurements of 0+ --> 0+ transitions have been restricted to the nine that populate stable daughter nuclei. No more such cases exist, and any improvement in a critical Cabibbo-Kobayashi-Maskawa unitarity test must depend on precise measurements of more exotic nuclei. With this branching-ratio measurement, we show those to be possible for T(z)=-1 parents. We obtain a corrected Ft value of 3071(9) s, in good agreement with expectations. PMID:14525235

Hardy, J C; Iacob, V E; Sanchez-Vega, M; Neilson, R G; Azhari, A; Gagliardi, C A; Mayes, V E; Tang, X; Trache, L; Tribble, R E

2003-08-22

312

Formation of high-Beta plasmas in various modes of operation in TPE-2  

NASA Astrophysics Data System (ADS)

Confinement and stability properties of high-beta plasmas in a toroidal screw pinch machine with an elliptic minor cross-section and a small aspect ratio is discussed. Plasma diagnostics and data analysis, and results obtained in the usual mode of operation are discussed. Results of the matched screw-pinch mode are presented. In this mode, the bias field and predischarge current are combined with the power-crowbar circuits in such a way that Bt and Ip increase almost simultaneously to their maximum values in 0.5 msec at a nearly constant value of qI at the wall. For both modes, the time evolution of a typical discharge is shown.

Oomens, A. A. M.; Hayase, H.; Hirota, I.; Kiyama, H.; Kiyama, S.; Maejima, Y.; Sato, Y.; Yahagi, E.; Kito, M.

1987-08-01

313

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 900°C, 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

314

Parametric instabilities of circularly polarized Alfven waves in high-beta plasmas  

NASA Technical Reports Server (NTRS)

CGL relations including the effect of finite ion Larmor radius are used to consider a class of parametric instabilities of finite-amplitude, circularly polarized Alfven waves in high-beta plasmas. The disperison relation governing the instabilities is a sixth-order polynomial which is solved numerically. There are two types of instabilities: a modulational instability at k is less than k(0) and a relatively weak and narrow bandwidth instability at k is less than approximately k(0), where k and k(0) are the wavenumbers of the unstable density fluctuation and the 'pump' wave, respectively. It is shown that these instabilities can occur for left-handed pump waves and that the modulational instability is unstable over a very broad band in k with a maximum growth rate at finite k is not equal to 0.

Hamabata, Hiromitsu

1993-01-01

315

Laser fusion investigations on high-power photodissociation iodine lasers ISKRA  

NASA Astrophysics Data System (ADS)

At VNIIEF laser fusion investigations are based on photodissociation iodine lasers (the wavelength of radiation (lambda) equals 1.315 micrometers ). The main goals of the investigations are determination of ignition conditions, choice of target types, laser interaction regime, energy and other necessary characteristics. Beginning in 1980 we conducted experiments on irradiation of targets of different types on the one-channel four-beam facility ISKRA-4 producing 10 TW. In the last years ISKRA-4 was upgraded: we realized conversion to the second harmonic and introduced the eight-beam irradiation system. Experiments at the second harmonic yielded 1 kJ of energy and 3 TW of power. In 1989 we built and put into operation the 12-channel facility ISKRA-5 producing energy up to 30 kJ and power up to 120 TW. In 1990 we began a series of target irradiation experiments on this facility. The present work is a review of laser fusion investigations conducted on the facilities ISKRA-4 and ISKRA-5. It contains a brief description of the facilities and of some specific phenomena which occur during monopulse amplification in high-power iodine lasers. Considerable attention is paid to problems of direct-drive targets and experimental results obtained on ISKRA-4 which are given in comparison with the data of model calculations. The work is concluded with the results of first experiments on irradiation of targets with a reversed corona which were conducted on the facility ISKRA-5.

Kochemasov, Gennadiy G.

1993-04-01

316

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

NASA Astrophysics Data System (ADS)

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

Wuest, Craig R.

2001-03-01

317

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

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

318

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

PubMed

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 (55)Fe 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. PMID:23126946

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

319

An integrated multi-source JDL high-level fusion architecture using recombinant cognition synthesis  

NASA Astrophysics Data System (ADS)

High-Level fusion systems based on the JDL model are relatively immature. Current solutions lack a comprehensive ability to manage multi-source data in a multi-dimensional vector space, and generally do not integrate collection to action models in a cohesive thread. Recombinant Cognition Synthesis (RCS) leverages best-of-breed techniques with a geospatial, temporal and semantic data model to provide a unified methodology that recombines multi-source data with analytic and predictive algorithms to synthesize actionable intelligence. This architecture framework enables the traversal of entity relationships at different level of granularities and the discovery of latent knowledge, thereby facilitating the domain problem analysis and the development of a Course-of-Action to mitigate adversarial threats. RCS also includes process refinement techniques to achieve superior information dominance, by incorporating specialized metadata. This comprehensive and unified methodology delivers enhanced utility to the intelligence analyst, and addresses key issues of relevancy, timeliness, accuracy, and uncertainty by providing metrics via feedback loops within the RCS infrastructure that augment the efficiency and effectiveness of the end-to-end fusion processing chain.

Solano, Marco A.; Ekwaro-Osire, Stephen; Tanik, Murat M.

2009-04-01

320

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

321

High-power corrugates waveguide components for mm-wave fusion heating systems  

SciTech Connect

Considerable progress has been made over the last year in the U.S., Japan, Russia, and Europe in developing high power long pulse gyrotrons for fusion plasma heating and current drive. These advanced gyrotrons typically operate at a frequency in the range 82 GHz to 170 GHz at nearly megawatt power levels for pulse lengths up to 5 s. To take advantage of these new microwave sources for fusion research, new and improved transmission line components are needed to reliably transmit microwave power to plasmas with minimal losses. Over the last year, General Atomics and collaborating companies (Spinner GmbH in Europe and Toshiba Corporation in Japan) have developed a wide variety of new components which meet the demanding power, pulse length, frequency, and vacuum requirements for effective utilization of the new generation of gyrotrons. These components include low-loss straight corrugated waveguides, miter bends, miter bend polarizers, power monitors, waveguide bellows, de breaks, waveguide switches, dummy loads, and distributed windows. These components have been developed with several different waveguide diameters (32, 64, and 89 mm) and frequency ranges (82 GHz to 170 GHz). This paper describes the design requirements of selected components and their calculated and measured performance characteristics.

Olstad, R.A.; Doane, J.L.; Moeller, C.P.; O`Neill, R.C.; Di Martino, M.

1996-10-01

322

Intramolecular hetero-Michael addition of beta-hydroxyenones for the preparation of highly substituted tetrahydropyranones.  

PubMed

Structurally diverse beta-hydroxyenones are shown to undergo nonoxidative 6-endo-trig ring closure to form highly substituted tetrahydropyranones. Amberlyst-15, Al(ClO(4))(3) x 9 H(2)O and [Pd(MeCN)(4)](BF(4))(2) were found to be suitable catalysts for these intramolecular conjugate additions, preventing side reactions, such as dehydration or retroaldolisation. The use of [Pd(MeCN)(4)](BF(4))(2) is particularly effective, as this palladium-mediated reaction is under kinetic control and generates tri- and tetrasubstituted tetrahydropyranones with high levels of diastereocontrol. In the presence of the Lewis acid Al(ClO(4))(3) x 9 H(2)O, the reaction proceeded with a similar level of diastereocontrol; however, in contrast to [Pd(MeCN)(4)](BF(4))(2), this catalyst can promote enolisation. The palladium-mediated reaction was also found to be compatible with an enantioenriched beta-hydroxyenone substrate, giving no loss of enantiopurity upon ring closure. The most distinctive synthetic development to emerge from this new chemistry is the possibility to access tri- and tetrasubstituted 2,6-anti-tetrahydropyranones from anti-aldol precursors. These compounds are particularly difficult to access by using alternative methodologies. Two modes of activation were envisaged for the ring closure, involving metal coordination to either the C=C or C=O functional groups. Experimental results suggest that C=O coordination was the preferred mode of activation for reactions performed in the presence of Al(ClO(4))(3) x 9 H(2)O or [Pd(MeCN)(4)](BF(4))(2). PMID:16819725

Reiter, Maud; Turner, Hazel; Gouverneur, Véronique

2006-09-18

323

HIGH LUMINOSITY RHIC INSERTIONS, 0.5M BETA AT IP.  

SciTech Connect

An increase in RHIC collision luminosity is possible by reducing the beam size at the interaction point (IP). They present a method for reducing the IP beta function, {beta}*, from the design minimum of 1m to 0.5m. They demonstrate that this {beta}* = 0.5m configuration is achievable with existing RHIC power supplies for 100 GeV protons. They discuss the correction of the higher order IR multi-poles and the second order chromaticity.

TEPIKIAN,S.FISCHER,W.MACKAY,W.PILAT,F.HUANG,H.PTITSYN,V.SATOGATA,T.TRBOJEVIC,D.VAN ZEIJTS,J.

2003-05-12

324

Studies in high current density ion sources for heavy ion fusion applications  

NASA Astrophysics Data System (ADS)

This dissertation develops diverse research on small (diameter˜few mm), high current density (J˜several tens of mA/cm2) heavy ion sources. The research has been developed in the context of a programmatic interest within the Heavy Ion Fusion (HIF) Program to explore alternative architectures in the beam injection systems that use the merging of small, bright beams. An ion gun was designed and built for these experiments. Results of average current density yield () at different operating conditions are presented for K+ and Cs+ contact ionization sources and potassium aluminum silicate sources. Maximum values for a K+ beam of ˜90 mA/cm2 were observed in 2.3 mus pulses. Measurements of beam intensity profiles and emittances are included. Measurements of neutral particle desorption are presented at different operating conditions which lead to a better understanding of the underlying atomic diffusion processes that determine the lifetime of the emitter. Estimates of diffusion times consistent with measurements are presented, as well as estimates of maximum repetition rates achievable. Diverse studies performed on the composition and preparation of alkali aluminosilicate ion sources are also presented. In addition, this work includes preliminary work carried out exploring the viability of an argon plasma ion source and a bismuth metal vapor vacuum arc (MEVVA) ion source. For the former ion source, fast rise-times (˜1mus), high current densities (˜100 mA/cm2) and low operating pressures (<2 mtorr) were verified. For the latter, high but acceptable levels of beam emittance were measured (epsilonn ? 0.006 pi·mm·mrad) although measured currents differed from the desired ones (I˜5mA) by about a factor of 10.* *This work was performed under the auspices of the Office of Fusion Energy Science, U.S. Department of Energy by the University of California Lawrence Berkeley National Laboratory under contract No. DE-AC03-765F00098.

Chacon-Golcher, Edwin

325

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

326

Overview of inertial fusion and high-intensity laser plasma research in Europe  

NASA Astrophysics Data System (ADS)

Inertial fusion science is driven by 'the quest for ignition'. For many years, a 'conventional' route towards inertial fusion has been investigated using two different approaches: ignition by an inertial central hot spot could be obtained either through the direct or the indirect drive scheme. Both imply the use of a very large facility to operate the driver, which is a powerful laser in the current projects (LMJ in France as well as NIF in the US). The LMJ construction being on the way, a large amount of experimental and computational work is currently being done to deepen the understanding of ignition requirements. On the other hand, the so-called 'fast ignition' approach has led to an increasingly important amount of scientific work since it was proposed at the beginning of the 1990s. During the last several years (from the previous IFSA held in Kyoto in 2001), several PW-class high-intensity laser facilities have been built in Europe. In the meantime, a large number of interesting results related to fast electron and proton production have been obtained with the existing facilities. Observation of laser-irradiated solid targets has provided the first evidence of electron bunches separated by half the period of light. Nevertheless, target heating remains modest. On the other hand, multi-megaelectronvolt highly collimated electron beams have been produced by table-top lasers interacting with the low-density plasmas. They open the feasibility of a lot of applications: x-ray probe beams in plasma physics, biology, chemistry, injector for conventional accelerators, etc). Laser-produced proton beams is also a growing field, with a lot of promising applications: proton therapy, radio-isotope production, diagnostic for transient phenomena in laser-plasma interaction, etc. Inertial fusion research is fostered by a sustained effort of organization and coordination at the national level (the creation of an Institute for Lasers and Plasmas in France) as well as at the European level (within the 6th Framework Program).

Tassart, J.

2004-12-01

327

Radiation induced noise in x-ray imagers for high-yield inertial confinement fusion experiments  

NASA Astrophysics Data System (ADS)

The large fluence of 14-MeV neutrons produced in high-yield inertial confinement fusion (ICF) experiments creates a variety of backgrounds in x-ray imagers viewing the implosion. Secondary charged particles produce background light by Cherenkov emission, phosphor screen excitation and possibly scintillation in the optical components of the imager. In addition, radiation induced optical absorption may lead to attenuation of the signal. Noise is also produced directly in the image recorder itself (CCD or film) via energy deposition by electrons and heavy charged particles such as protons and alphas. We will present results from CCD background measurements and compare them to Monte Carlo calculations. In addition we show measurements of luminescence and long-term darkening for some of the glasses employed in imagers.

Hagmann, C.; Ayers, J.; Bell, P. M.; Bourgade, J.-L.; Bradley, D. K.; Celeste, J.; Cerjan, C.; Darbon, S.; Emig, J.; Felker, B.; Glenn, S.; Holder, J.; Izumi, N.; Kilkenny, J. D.; Moody, J.; Piston, K.; Rousseau, A.; Smalyuk, V. A.; Sorce, C.

2011-09-01

328

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

329

Particle dynamics in a DTL for high intensity heavy ion beams for inertial fusion  

SciTech Connect

Multi-particle beam dynamics calculations in presence of large beam currents have been carried out for a heavy ion Drift Tube Linac (DTL), in the framework of a European study group on Heavy Ion Driven Inertial Fusion (HIDIF). Linac design parameters were determined for high transmission and low emittance growth; then statistical errors as well as on-axis mismatch were added. The influence of field errors and different mismatch combinations on beam halo formation and emittance increase has been studied numerically, e.g. phase and amplitude jitters of the rf field, small changes of quadrupole gradients, mismatch of beam bunches at linac input. For proper ring injection, a transfer line and a bunch rotation cavity have to be inserted between linac and storage rings. The energy spread reduction after bunch rotation has been investigated both numerically and analytically, comparing an ideal case with a more realistic one which includes rf errors and mismatch.

Parisi, Giovanni; Deitinghoff, Horst [Institut fuer Angewandte Physik der J. W. Goethe-Universitaet, Robert-Mayer-Strasse 2-4, D-60054 Frankfurt am Main (Germany); Bongardt, Klaus; Pabst, Michael [Forschungszentrum Juelich GmbH, Postfach 1913, D-52425 Juelich (Germany)

1999-06-09

330

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.

2011-01-01

331

Fusion ignition research experiment.  

National Technical Information Service (NTIS)

Understanding the properties of high gain (alpha-dominated) fusion plasmas in an advanced toroidal configuration is the largest remaining open issue that must be addressed to provide the scientific foundation for an attractive magnetic fusion reactor. The...

D. Meade

2000-01-01

332

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

333

Production, purification, and characterization of a highly glucose-tolerant novel beta-glucosidase from Candida peltata.  

PubMed Central

Candida peltata (NRRL Y-6888) produced beta-glucosidase when grown in liquid culture on various substrates (glucose, xylose, L-arabinose, cellobiose, sucrose, and maltose). An extracellular beta-glucosidase was purified 1,800-fold to homogeneity from the culture supernatant of the yeast grown on glucose by salting out with ammonium sulfate, ion-exchange chromatography with DEAE Bio-Gel A agarose, Bio-Gel A-0.5m gel filtration, and cellobiose-Sepharose affinity chromatography. The enzyme was a monomeric protein with an apparent molecular weight of 43,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration. It was optimally active at pH 5.0 and 50 degrees C and had a specific activity of 108 mumol.min-1.mg of protein-1 against p-nitrophenyl-beta-D-glucoside (pNP beta G). The purified beta-glucosidase readily hydrolyzed pNP beta G, cellobiose, cellotriose, cellotetraose, cellopentaose, and cellohexaose, with Km values of 2.3, 66, 39, 35, 21, and 18 mM, respectively. The enzyme was highly tolerant to glucose inhibition, with a Ki of 1.4 M (252 mg/ml). Substrate inhibition was not observed with 40 mM pNP beta G or 15% cellobiose. The enzyme did not require divalent cations for activity, and its activity was not affected by p-chloromercuribenzoate (0.2 mM), EDTA (10 mM), or dithiothreitol (10 mM). Ethanol at an optimal concentration (0.75%, vol/vol) stimulated the initial enzyme activity by only 11%. Cellobiose (10%, wt/vol) was almost completely hydrolyzed to glucose by the purified beta-glucosidase (1.5 U/ml) in both the absence and presence of glucose (6%). Glucose production was enhanced by 8.3% when microcrystalline cellulose (2%, wt/vol) was treated for 24 h with a commercial cellulase preparation (cellulase, 5 U/ml; beta-glucosidase, 0.45 U/ml) that was supplemented with purified beta-glucosidase (0.4 U/ml).

Saha, B C; Bothast, R J

1996-01-01

334

Highly efficient retrograde gene transfer into motor neurons by a lentiviral vector pseudotyped with fusion glycoprotein.  

PubMed

The development of gene therapy techniques to introduce transgenes that promote neuronal survival and protection provides effective therapeutic approaches for neurological and neurodegenerative diseases. Intramuscular injection of adenoviral and adeno-associated viral vectors, as well as lentiviral vectors pseudotyped with rabies virus glycoprotein (RV-G), permits gene delivery into motor neurons in animal models for motor neuron diseases. Recently, we developed a vector with highly efficient retrograde gene transfer (HiRet) by pseudotyping a human immunodeficiency virus type 1 (HIV-1)-based vector with fusion glycoprotein B type (FuG-B) or a variant of FuG-B (FuG-B2), in which the cytoplasmic domain of RV-G was replaced by the corresponding part of vesicular stomatitis virus glycoprotein (VSV-G). We have also developed another vector showing neuron-specific retrograde gene transfer (NeuRet) with fusion glycoprotein C type, in which the short C-terminal segment of the extracellular domain and transmembrane/cytoplasmic domains of RV-G was substituted with the corresponding regions of VSV-G. These two vectors afford the high efficiency of retrograde gene transfer into different neuronal populations in the brain. Here we investigated the efficiency of the HiRet (with FuG-B2) and NeuRet vectors for retrograde gene transfer into motor neurons in the spinal cord and hindbrain in mice after intramuscular injection and compared it with the efficiency of the RV-G pseudotype of the HIV-1-based vector. The main highlight of our results is that the HiRet vector shows the most efficient retrograde gene transfer into both spinal cord and hindbrain motor neurons, offering its promising use as a gene therapeutic approach for the treatment of motor neuron diseases. PMID:24086660

Hirano, Miyabi; Kato, Shigeki; Kobayashi, Kenta; Okada, Tomoaki; Yaginuma, Hiroyuki; Kobayashi, Kazuto

2013-01-01

335

Exposure fusion based on steerable pyramid for displaying high dynamic range scenes  

Microsoft Academic Search

Currently, most exposure fusion algorithms are put forward on the assumption that the source images are aligned prior to fusion. As a result, some artifacts, such as haloing, may be caused due to the slight misalignment in the source images. In order to reduce the influence induced by the misalignment, a novel shift-invariant and rotation-invariant steerable pyramid-based exposure fusion (SPBEF)

Jinhua Wang; De Xu; Bing Li

2009-01-01

336

Impact of MHD equilibrium input variations on the high beta stability boundaries of NSTX  

NASA Astrophysics Data System (ADS)

Ideal MHD stability limits of anticipated plasma configurations for NSTX [Ono M. et al 2000 Nucl. Fusion 40 557] and the dependence on the parameters defining the MHD equilibrium are evaluated. The study provides a quantitative computational evaluation of the stability limit variations induced by changes to the equilibrium of NSTX high ? plasmas. The analysis is based on a reference free-boundary equilibrium with ? = 41.5%, monotonic safety factor q profile (qa = 12.1, q0 = 2.8) and broad pressure profile p (peaking factor Fp?p(0)/langleprangle = 1.7). On this reference target local variation of the plasma boundary, and the safety factor q and pressure profiles p are imposed. Localized inflection of the outboard plasma boundary, produced by near field effects from poloidal shaping field coils, weaken the stability due to the destabilization of high n ballooning modes. Variation of the q profile at different radial locations can also degrade stability. Both experimental profiles from existing tokamaks and spherical torus machines and profiles generated from transport modelling of anticipated neutral beam heated plasmas are used. Degraded stability is found at increasing pressure peaking factor due to the destabilization of n = 1 kink/ballooning modes. Direct access to the second region of stability is found in certain configurations and, for the entire set of variations considered, the lower calculated ? limit values are still in the range of 20.0% without considering the stabilizing effect of the passive conducting structures.

Paoletti, F.; Sabbagh, S. A.; Manickam, J.; Menard, J.; Akers, R. J.; Gates, D.; Kaye, S. M.; Lao, L.

2002-04-01

337

High-performance thin-layer chromatography densitometric determination of beta-sitosterol in Phyllanthus species.  

PubMed

An HPTLC densitometric method was established for the determination of beta-sitosterol in in vitro cultures of some species of the genus Phyllanthus. Two derivatization reagents commonly used in TLC for the visualization and detection of sterols, namely, anisaldehyde reagent and 5% phosphomolybdic acid, were compared with vanillin reagent. The densitometric quantification of beta-sitosterol was carried out on HPTLC Si60 F254 plates with the mobile phase chloroform-hexane-methanol (65 + 30 + 5, vlv/v) at 525 nm. The method was validated for each derivatization reagent in terms of linearity, precision, repeatability, intra- and interday precision, LOD, and LOQ. The presence of beta-sitosterol was revealed in all analyzed plant material. The concentrations of beta-sitosterol determined ranged from 0.48 to 2.75 mg/g (dry weight). In addition, traces of beta-amyrin were detected in some plant samples. PMID:19916371

Sparzak, Barbara; Krauze-Baranowska, Miros?awa; Pobiocka-Olech, Loretta

2009-01-01

338

Tokamak fusion power reactors  

Microsoft Academic Search

The major parameters and corresponding economic characteristics of a representative class of commercial Tokamak fusion power reactors are examined as a function of four major design parameters: plasma beta-t, toroidal magnetic field strength, first-wall lifetime, and power output. It is shown that for beta-t greater than or equal to 0.06, the minimum cost of energy is obtained for toroidal field

W. M. Stacey Jr.; M. A. Abdou

1978-01-01

339

High expression of thymosin beta 10 predicts poor prognosis for hepatocellular carcinoma after hepatectomy  

PubMed Central

Background Thymosin beta 10 (Tbeta10) overexpression has been reported in a variety of human cancers. However, the role of Tbeta10 in hepatocellular carcinoma (HCC) remains unclear. The aim of the present study was to analyze Tbeta10 expression in tumor and matched non-tumorous tissues, and to assess its prognostic significance for HCC after hepatectomy. Methods The level of Tbeta10 mRNA and protein in tumor and matched non-tumorous tissues was evaluated in 26 fresh HCC cases by reverse transcription-polymerase chain reaction (RT-PCR) and western blot. Additionally, Tbeta10 protein expression in 196 HCC was analyzed by immunohistochemistry (IHC) and correlated with clinicopathological characteristics and survival. Results Results from RT-PCR and western blot analysis show that the levels of Tbeta10 mRNA and protein were significantly higher in tumor tissues of HCC, compared to that in matched non-tumorous tissues (P?=?0.01 and P <0.001, respectively). IHC staining showed that high expression of Tbeta10 was detected in 58.2% (114/196) of HCC cases. High expression of Tbeta10 was significantly associated with advanced TNM stage (P <0.001). Survival analysis demonstrated that high Tbeta10 was related to shorter overall survival (OS) (P?=?0.000) and disease-free survival (DFS) (P?=?0.000). Multivariate analysis showed that high expression of Tbeta10 was an independent prognostic factor for both OS (P?=?0.001, HR?=?4.135, 95% CI: 2.603 to 6.569) and DFS (P?=?0.001, HR?=?2.021, 95% CI: 1.442 to 2.832). Subgroup analysis revealed that high expression of Tbeta10 predicts poorer survival for early and advanced stage. Conclusions Tbeta10 protein abnormal expression might contribute to the malignant progression of HCC. High expression of Tbeta10 predicts poor prognosis in patients with HCC after hepatectomy.

2014-01-01

340

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

341

Beta-alanine supplementation reduces acidosis but not oxygen uptake response during high-intensity cycling exercise.  

PubMed

The oral ingestion of beta-alanine, the rate-limiting precursor in carnosine synthesis, has been shown to elevate the muscle carnosine content. Carnosine is thought to act as a physiologically relevant pH buffer during exercise but direct evidence is lacking. Acidosis has been hypothesised to influence oxygen uptake kinetics during high-intensity exercise. The present study aimed to investigate whether oral beta-alanine supplementation could reduce acidosis during high-intensity cycling and thereby affect oxygen uptake kinetics. 14 male physical education students participated in this placebo-controlled, double-blind study. Subjects were supplemented orally for 4 weeks with 4.8 g/day placebo or beta-alanine. Before and after supplementation, subjects performed a 6-min cycling exercise bout at an intensity of 50% of the difference between ventilatory threshold (VT) and VO(2peak). Capillary blood samples were taken for determination of pH, lactate, bicarbonate and base excess, and pulmonary oxygen uptake kinetics were determined with a bi-exponential model fitted to the averaged breath-by-breath data of three repetitions. Exercise-induced acidosis was significantly reduced following beta-alanine supplementation compared to placebo, without affecting blood lactate and bicarbonate concentrations. The time delay of the fast component (Td(1)) of the oxygen uptake kinetics was significantly reduced following beta-alanine supplementation compared to placebo, although this did not reduce oxygen deficit. The parameters of the slow component did not differ between groups. These results indicate that chronic beta-alanine supplementation, which presumably increased muscle carnosine content, can attenuate the fall in blood pH during high-intensity exercise. This may contribute to the ergogenic effect of the supplement found in some exercise modes. PMID:19841932

Baguet, Audrey; Koppo, Katrien; Pottier, Andries; Derave, Wim

2010-02-01

342

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

343

Yttrium-90 -- current status, expected availability and applications of a high beta energy emitter.  

PubMed

Yttrium-90 ((90)Y, T(1/2) 64.14 h) is a key example of a high beta energy-emitting radionuclide which is available from the strontium-90 ((90)Sr)/(90)Y radionuclide generator system. Clinical uses of (90)Y-labeled radiopharmaceutical agents have been pursued for many years and many applications have proven to be clinical effective. These most notably include the application of 90Y-labeled antibodies for a variety of applications such as for effective treatment of non-Hodgkin's lymphoma. One of the major advantages for use of (90)Y is ready availability from the very long-lived (90)Sr parent (T(1/2) 28.78 y). Because of the importance of maintaining generator performance and minimizing parent breakthrough, this paper describes development, use and quality control of both high capacity cation adsorption-type and electrochemical generator systems. In addition, the preparation and targeting to tumors in mice of DOTA-conjugated Nimotuzamab (h-R3) antibody which recognizes the external domain of the EPFR antibody radiolabeled with (90)Y obtained from the electrochemical generator is also described. As a key example for clinical applications of (90)Y, the use of (90)Y-labeled biotin for intra-operative pre-targeting for radionuclide therapy (IART®) of breast cancer is also described. PMID:22697484

Montaña, R Leyva; González, I Hernández; Ramirez, A Alberti; Garaboldi, L; Chinol, M

2012-07-01

344

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

345

High frequency of beta-catenin mutations in borderline endometrioid tumours of the ovary.  

PubMed

Some low-grade endometrioid carcinomas arise from a background of endometrioid tumours of borderline malignancy. To determine the molecular mechanisms involved in the initiation of endometrioid carcinoma, the present study investigated whether the genetic alterations reported in these tumours (mutations in PTEN, KRAS, and beta-catenin genes, and microsatellite instability) are already present in endometrioid tumours of borderline malignancy. Eight endometrioid tumours of borderline malignancy were studied. By immunohistochemistry, beta-catenin was expressed in the nuclei of all tumours, suggesting the presence of stabilizing beta-catenin mutations. By mutational analysis, five different beta-catenin mutations were found in seven of eight cases (90%), affecting codons 32, 33, and 37. In contrast, only one tumour harboured a PTEN mutation, which affected codon 130. Neither KRAS mutations nor microsatellite instability was detected. A review of the literature indicated that beta-catenin mutations are characteristic of well-differentiated endometrioid carcinomas, since they were present in nearly 60% of grade I but in less of 3% of grade III tumours. In conclusion, the present study identifies beta-catenin mutation as a nearly constant molecular alteration in borderline endometrioid tumours, whereas PTEN and KRAS mutations and microsatellite instability are very infrequent. The findings in the present study, and previously reported data, strongly suggest that beta-catenin mutation is an early event in endometrioid ovarian carcinogenesis, and that it is involved in the development of low-grade endometrioid tumours. PMID:16429393

Oliva, E; Sarrió, D; Brachtel, E F; Sánchez-Estévez, C; Soslow, R A; Moreno-Bueno, G; Palacios, J

2006-04-01

346

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 (1.8–2.59%) 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.

2008-01-01

347

Distributed Combined Authentication and Intrusion Detection With Data Fusion in High-Security Mobile Ad Hoc Networks  

Microsoft Academic Search

Multimodal biometric technology provides potential solutions for continuous user-to-device authentication in high- security mobile ad hoc networks (MANETs). This paper studies distributed combined authentication and intrusion detection with data fusion in such MANETs. Multimodal biometrics are deployed to work with intrusion detection systems (IDSs) to alleviate the shortcomings of unimodal biometric systems. Since each device in the network has measurement

Shengrong Bu; F. Richard Yu; Xiaoping P. Liu; Peter Mason; Helen Tang

2011-01-01

348

Development of a high-brightness, applied-B lithium extraction ion diode for inertial confinement fusion  

Microsoft Academic Search

Summary form only given. The light ion fusion program is pursuing the development of a high brightness lithium ion beam on the SABRE accelerator at Sandia (6 MV, 0.25 MA). This will require the integration of at least three conditions: 1) an active, pre-formed, uniform lithium plasma ion source, 2) modification of the electron sheath distribution in the AK gap,

M. E. Cuneo; R. G. Adams; J. Armijo; J. E. Bailey; C. H. Ching; M. P. Desjarlais; A. B. Filuk; W. E. Fowler; P. R. Hanson; D. J. Johnson; J. S. Lash; T. A. Mehlhorn; P. R. Merge; D. Nielsen; T. D. Pointon; S. A. Slutz; M. A. Stark; R. A. Versey; D. F. Wenger

1997-01-01

349

Thermohydraulic analysis of high-Prandtl-number fluid in complex duct simulating first wall in fusion reactor  

Microsoft Academic Search

For fusion reactors, molten salt is one of the candidates for coolant materials. Molten salt is a high-Prandtl-number fluid; thus, it is necessary to enhance the heat transfer coefficient. It is proposed that rods are inserted into a duct to enhance the heat transfer coefficient. The flow field behind the rod in the duct is visualized to compare experimental data

Masaaki Satake; Kazuhisa Yuki; Hidetoshi Hashizume

2010-01-01

350

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

351

On reliability and trustworthiness of high-level fusion-based decision support systems: basic concepts and possible formal methodologies  

Microsoft Academic Search

The paper summarizes the result of a literature study of robust uncertainty management methodologies, carried out to indicate options available in the design and construction of trustworthy decision support systems based on high-level information fusion methods. Among the candidate methodologies briefly discussed for creating trustworthy decision support are robust Bayesian statistics, imprecise probabilities and sensitivity analysis of simulation models. However,

Per Svensson

2006-01-01

352

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

353

Demountable low stress high field toroidal field magnet system for tokamak fusion reactors  

Microsoft Academic Search

A new type of superconducting magnet system for large fusion reactors is described in this report. Instead of winding large planar or multi-axis coils, as has been proposed in previous fusion reactor designs, the superconducting coils are made by joining together several prefabricated conductor sections. The joints can be unmade and sections removed if they fail. Conductor sections can be

J. Powell; D. Hsieh; J. Lehner; M. Suenaga

1977-01-01

354

CVD diamond as a high bandwidth neutron detector for inertial confinement fusion diagnostics  

Microsoft Academic Search

We characterize the response of chemical vapor deposition (CVD) diamond detectors to inertial confinement fusion (ICF) neutrons generated at the OMEGA laser fusion facility in Rochester, NY. Four detectors are tested: three utilizing ``optical grade'' CVD diamond, and one utilizing ``electronic grade'' CVD diamond. Using a 50 Omega measurement system, we find that the optical grade wafers, biased to 1000

G. J. Schmid; R. L. Griffith; N. Izumi; J. A. Koch; R. A. Lerche; M. J. Moran; T. W. Phillips; R. E. Turner; V. Yu. Glebov; T. C. Sangster; C. Stoeckl

2003-01-01

355

A NATIONAL COLLABORATORY TO ADVANCE THE SCIENCE OF HIGH TEMPERATURE PLASMA PHYSICS FOR MAGNETIC FUSION  

Microsoft Academic Search

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

Allen R. Sanderson; Christopher R. Johnson

2006-01-01

356

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

357

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

358

A review of high-level multisensor fusion: approaches and applications  

Microsoft Academic Search

The potential advantages in multisensor fusion can be obtained more accurately, concerning feature that are impossible to perceive with individual sensors, as well as in less time, and at a lower cost. The characterization most commonly encountered in the rapidly growing multisensor fusion literature based on levels of detail in the information is that of the now well known triple

Ren C. Luo; K. L. Su

1999-01-01

359

Testbed for distributed high-level information fusion and dynamic resource management  

Microsoft Academic Search

The testbed allows experimenting with highlevel distributed information fusion, dynamic resource management and configuration management given multiple constraints on the resources and their communication networks. The testbed provides general services that are useful for testing many information fusion applications. Services include a multi-layer plug-and-play architecture, and a general multi-agent framework based on John Boyd's OODA loop.

Pierre Valin; Eloi Bossé; Adel Guitouni; Hans Wehn; Jens Happe

2010-01-01

360

Highly efficient protein expression and purification using bacterial hemoglobin fusion vector  

Microsoft Academic Search

Recently developed bacterial hemoglobin (VHb) fusion expression vector has been widely used for the production of many target proteins due to its distinctive properties of expressing fusion protein with red color which facilitates visualization of the steps in purification, and increasing solubility of the target proteins. However, after intensive use of the vector, several defects have been found. In this

Soo-Young Kwon; Yoon-Joo Choi; Tae-Hong Kang; Kwang-Hoon Lee; Sun-Shin Cha; Gyung-Hwa Kim; Heung-Soo Lee; Kyong-Tai Kim; Kyung-Jin Kim

2005-01-01

361

Peripheral plasma levels of beta-endorphin in alcoholics and highly trained athletes and the relationship to a measure of central opioid tone.  

PubMed

Human beta-endorphin-like immunoactivity was measured in highly trained athletes (n = 10), alcoholics in the early phase of abstinence (n=9) and normal controls (n=15) using the Nichols Allegro immunoradiometric assay. The assay was examined for cross reactivity against related peptides, beta-lipotropin and human N-acetyl beta-endorphin. Venous blood sampling was carried out in the morning at 0900 and 1100 hours in a fasting state. Using two-way analysis of variance there was a significant effect of subject group on beta-endorphin concentration (p=0.029). Post-hoc analysis using the Bonferroni t-test showed that the source of the difference was the alcoholic group having significantly lower beta-endorphin immunoreactivity (p < 0.05). There was no difference between the controls and the athletes. There was a positive correlation between plasma beta-endorphin level at 1100 hours and the subsequent ACTH incremental response to naloxone in the group as a whole (r=0.48, p=0.004). The assay showed 100% cross reactivity with beta-lipotropin and 73% cross reactivity with N-acetyl-beta-endorphin. We conclude that alcoholics have reduced levels of beta-endorphin-like immunoactivity. While beta-endorphin is known not to cross the blood-brain barrier, levels of plasma beta-endorphin-like immunoactivity may indirectly reflect central opioid activity. PMID:9761384

Inder, W J; Livesey, J H; Donald, R A

1998-08-01

362

Non-fossil energy for the production of synthetic fuels from coal. I. Fusion reactor with high temperature steam electrolyzer and gasifier  

Microsoft Academic Search

Fusion reactors could displace a large amount of the coal needed for synthetic fuel production. A unique feature of a fusion reactor is that it can potentially supply high temperature steam in the range of 1000° to 1500°C in a continuous manner. The high temperature steam would be obtained by internal heating of a refractory containing blanket section which would

Steinberg

1978-01-01

363

Non-fossil energy for the production of synthetic fuels from Coal I. Fusion reactor with high temperature steam electrolyzer and gasifier  

Microsoft Academic Search

Fusion reactors could displace a large amount of the coal needed for synthetic fuel production. A unique feature of a fusion reactor is that it can potentially supply high temperature steam in the range of 1000° to 1500°C in a continuous manner. The high temperature steam would be obtained by internal heating of a refractory containing blanket section which would

Steinberg

1980-01-01

364

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

NASA Astrophysics Data System (ADS)

The ratio of the plasma pressure to the magnetic field pressure (or of their energy densities) which is known as the plasma parameter ``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 ?ep) of the energetic ions' (20 keV to ~5 MeV) to the magnetic field's in order to find occurrences of high-beta (?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.

2011-01-01

365

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

366

Life Studies of Metal Films on Beta-Alumina at High Temperature  

NASA Technical Reports Server (NTRS)

Applications of metallic films on sodium beta-alumina solid electrolyte (BASE) ceramic in technology for the alkali metal thermal to electric converter (AMTEC) include both electrode and metallization functions.

Williams, R.; Kisor, A.; Fiebig, B.; Cortez, R.; Ryan, M.; Shields, V.; Homer, M.

2000-01-01

367

Effects of High Pressure on Alpha and Beta Adrenergic Receptors of the Rabbit Duodenum.  

National Technical Information Service (NTIS)

In analyzing the effects of hyperbaric helium-oxygen on alpha and beta adrenergic receptors of rabbit duodenum, norepinephrine latency was found to vary directly and linearly with the increase in pressure. This relationship is described by the equation Y ...

T. K. Akers D. K. MacCarter

1972-01-01

368

Effect of beta-sitosterol concentration and high pressure homogenization on the chlorhexidine release from vesicular gels.  

PubMed

Previous studies have confirmed that the phase transition of vesicular gels of hydrogenated phospholipids to the less ordered fluid vesicular state was induced by the increase of the beta-sitosterol ratio in the whole gel system and consequently in the lipid bilayer. The purpose of the present study was to evaluate the influence of the beta-sitosterol portion in the lipid bilayer and the effect of high pressure homogenization on the structural characteristics of the prepared gel systems. In addition the influence of beta-sitosterol on the consequent chlorhexidine release from the obtained vesicles and liposomes was also examined. Lipid mixtures were prepared from different molar ratios of lecithin:sterol components (90:10-65:35 mol%). The obtained mixtures were hydrated with the aqueous solution of chlorhexidine digluconate in order to achieve a 30% (w/w) final concentration of the lipid mixtures and a 4% (w/w) concentration of the drug. One portion of the resultant multilamellar vesicles was homogenized by using high pressure. To characterize the homogenized and non-homogenized systems, transmission electron microscopy of the freeze-fractured samples and differential scanning calorimetry (DSC) were carried out. A vertical type diffusion cell was applied to determine the amount of released chlorhexidine digluconate. Along with the increase in beta-sitosterol concentration, the fluidity of the membrane as well as its permeability also increased. The increased permeability--caused by the higher beta-sitosterol concentration--and the high pressure homogenization, which increased the dispersity and therefore the surface area, enabled a higher amount of chlorhexidine to be released. The increase of drug release was more pronounced in the case of samples prepared with high pressure homogenization. PMID:16257155

Farkas, E; Schubert, R; Zelkó, R

2006-01-01

369

Bifurcations of tokamak equilibria at high. beta. associated with ideal n = 0 n = infinity mode stabilization  

SciTech Connect

The bifurcation theory of elastic structures is applied to two analagous problems in ideal magnetohydrodynamics. In a tokamak or similar toroidal plasma confinement machine, stable bifurcations of an axisymmetric equilibrium are associated with instabilities having a toroidal model number of n = 0 or n = infinity. The former, the axisymmetric mode, as well as the latter, the ballooning mode, have a regime of second stability at high ..beta... A method for crossing the linearly unstable regime, granting sufficient energy deposition, is brought to light through use of the stable bifurcations. The Lyapunov-Schmidt expansion for solutions of nonlinear equilibrium equations at a critical point highlights the analysis. From it, a potential energy function possessing all the bifurcation information is obtained as a projection of the energy functional for the plasma. This function reveals the connection between equilibrium and stability. The bifurcation point is simultaneously the critical value for instability. Elementary catastrophe surfaces arise for various choices of a nonlinear current density profile in the axisymmetric mode problem. For the ballooning mode, a variation of the procedure is used to derive the cusp catastrophe surface as the pertinent model.

Elkin, D.J.

1984-01-01

370

Stability Analysis of Resistive Wall Mode in Rotating High-beta Plasmas in DIII-D  

NASA Astrophysics Data System (ADS)

Stability of resistive wall modes (RWM) in rotating high beta DIII-D discharges is analyzed using the MARS-F code. The modes are calculated in axisymmetric toroidal equilibrium using the MHD plasma model with kinetic damping effects. RWM are analyzed for different spacing between the resistive wall and the plasma boundary and for different toroidal rotation profiles. Sensitivity study of the mode's stability on the plasma edge q-profile is made by varying both the edge current profile and the proximity of the plasma boundary to the real X-point geometry. The importance of the edge modeling on accurate RWM stability analysis is revisited. Scans of the mode's growth rate and frequency are made in these settings, and the mode's structure is explored. Quasilinear toroidal torque driven by jxB force due to current and magnetic field perturbations in the RWM is estimated and compared with the experimental estimate of the total toroidal torque on plasma. The dependencies of the RWM growth rate and frequency on the stability and torque parameters are presented.

Svidzinski, V. A.; in, Y.; Kim, J. S.; Chu, M. S.; Liu, Y. Q.

2011-11-01

371

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

372

High Sensitivity Detection of Xe Isotopes Via Beta-Gamma Coincidence Counting  

Microsoft Academic Search

Measurement of xenon fission product isotopes is a key element in the global network being established to monitor the Comprehensive Nuclear-Test-Ban Treaty. Pacific Northwest National Laboratory has developed an automated system for separating Xe from air which includes a beta-gamma counting system for 131mXe, 133mXe, 133Xe, and 135Xe. Betas and conversion electrons are detected in a plastic scintillation cell containing

Ted W. Bowyer; Justin I. McIntyre; Paul L. Reeder

1999-01-01

373

Empirical Study of Knowledge Fusion Process within Chinese High-Tech Industry Clusters Based on Information Fusion Method  

Microsoft Academic Search

In order to consider the future development of high-tech industry clusters, this paper applies an evolution perspective to look into the knowledge integration process from both local and global knowledge linkages of entrepreneurs within the industry cluster. This paper has established a model to explore the entrepreneur's knowledge spillover and diffusion process which promotes the high-technology industry cluster's technology upgrading.

Congying Wang; Bei Hu; Peng Li

2009-01-01

374

Interaction of the small interstitial proteoglycans biglycan, decorin and fibromodulin with transforming growth factor beta.  

PubMed Central

We have analysed the interactions of three proteoglycans of the decorin family, decorin, biglycan and fibromodulin, with transforming growth factor beta (TGF-beta). The proteoglycan core proteins, expressed from human cDNAs as fusion proteins with Escherichia coli maltose-binding protein, each bound TGF-beta 1. They showed only negligible binding to several other growth factors. Intact decorin, biglycan and fibromodulin isolated from bovine tissues competed with the fusion proteins for the TGF-beta binding. Affinity measurements suggest a two-site binding model with Kd values ranging from 1 to 20 nM for a high-affinity binding site and 50 to 200 nM for the lower-affinity binding site. The stoichiometry indicated that the high-affinity binding site was present in one of ten proteoglycan core molecules and that each molecule contained a low-affinity binding site. Tissue-derived biglycan and decorin were less effective competitors for TGF-beta binding than fibromodulin or the non-glycosylated fusion proteins; removal of the chondroitin/dermatan sulphate chains of decorin and biglycan (fibromodulin is a keratan sulphate proteoglycan) increased the activities of decorin and biglycan, suggesting that the glycosaminoglycan chains may hinder the interaction of the core proteins with TGF-beta. The fusion proteins competed for the binding of radiolabelled TGF-beta to Mv 1 Lu cells and endothelial cells. Affinity labelling showed that the binding of TGF-beta to betaglycan and the type-I receptors in Mv 1 Lu cells and to endoglin in endothelial cells was reduced, but the binding to the type-II receptors was unaffected. TGF-beta 2 and 3 also bound to all three fusion proteins. Latent recombinant TGF-beta 1 precursor bound slightly to fibromodulin and not at all to decorin and biglycan. The results show that the three decorin-type proteoglycans each bind TGF-beta isoforms and that slight differences exist in their binding properties. They may regulate TGF-beta activities by sequestering TGF-beta into extracellular matrix. Images Figure 1 Figure 8 Figure 9

Hildebrand, A; Romaris, M; Rasmussen, L M; Heinegard, D; Twardzik, D R; Border, W A; Ruoslahti, E

1994-01-01

375

Preliminary analysis of alpha-particle effects in the fusion ignition experiment ignitex  

Microsoft Academic Search

In this paper a simple fusion experiment for the production and control do deuterium-tritium-ignited plasmas for scientific study is considered. The basic elements of fusion product alpha-particle containment is rather high even with the assumption of significant levels of toroidal asymmetries. Production of thermally stable plasmas is possible because of the low-beta thermal damping provided by electron cyclotron emission. The

R. Carrera; E. Montalvo; G. Y. Fu; G. H. Miley; L. M. Hively; M. N. Rosenbluth; S. Tamor

1990-01-01

376

Production of high purity TeO 2 single crystals for the study of neutrinoless double beta decay  

Microsoft Academic Search

High purity TeO2 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

C. Arnaboldi; C. Brofferio; A. Bryant; C. Bucci; L. Canonica; S. Capelli; M. Carrettoni; M. Clemenza; I. Dafinei; S. Di Domizio; F. Ferroni; E. Fiorini; Z. Ge; A. Giachero; L. Gironi; A. Giuliani; P. Gorla; E. Guardincerri; R. Kadel; K. Kazkaz; L. Kogler; Y. Kolomensky; J. Larsen; M. Laubenstein; Y. Li; C. Maiano; M. Martinez; R. Maruyama; S. Nisi; C. Nones; Eric B. Norman; A. Nucciotti; F. Orio; L. Pattavina; M. Pavan; G. Pessina; S. Pirro; E. Previtali; C. Rusconi; Nicholas D. Scielzo; M. Sisti; Alan R. Smith; W. Tian; M. Vignati; H. Wang; Y. Zhu

2010-01-01

377

High-dose, frequently administered interferon beta therapy for relapsing–remitting multiple sclerosis must be maintained over the long term: the interferon beta dose-reduction study  

Microsoft Academic Search

Long-term trials have demonstrated the continued efficacy of interferon (IFN) beta treatment in patients with relapsing–remitting (RR) multiple sclerosis (MS) during prolonged administration.The objective of the work was to evaluate the effects of reducing IFN beta administration frequency and total weekly dose in patients with RR MS who have achieved clinical and MRI disease activity stabilization during long-term IFN beta-1b

Pierangelo Barbero; Elisabetta Verdun; Mauro Bergui; Antonio Pipieri; Marinella Clerico; Angele Cucci; Alessandra Ricci; Bruno Bergamasco; Luca Durelli

2004-01-01

378

Early treatment with high-dose interferon beta-1a reverses cognitive and cortical plasticity deficits in multiple sclerosis  

PubMed Central

Summary Acute inflammation is associated with cognitive deficits and alterations of cortical plasticity in multiple sclerosis (MS). We tested whether early treatment with high-dose interferon (IFN) beta-1a, known to reduce inflammatory activity, improves cortical function and cognitive deficits in MS. Eighty treatment-naïve relapsing-remitting MS (RRMS) patients received IFN beta-1a (44 mcg) subcutaneously three times per week. Cognitive performance and cortical plasticity were measured through the paced auditory serial addition test (PASAT) and intermittent theta burst stimulation (iTBS) before and up to two years after IFN beta-1a initiation. Before treatment, patients with gadolinium-enhancing lesions (Gd+) on MRI performed worse on the PASAT, and showed lower iTBS-induced plasticity, compared with Gd? patients. Six months after treatment initiation both PASAT and iTBS-induced plasticity improved in Gd+ and remained stable in Gd? patients. These results suggest that cognitive and synaptic plasticity deficits may be rescued during high-dose IFN beta-1a treatment in newly-diagnosed RRMS patients with Gd+ lesions.

Mori, Francesco; Kusayanagi, Hajime; Buttari, Fabio; Centini, Barbara; Monteleone, Fabrizia; Nicoletti, Carolina Gabri; Bernardi, Giorgio; Di Cantogno, Elisabetta Verdun; Marciani, Maria Grazia; Centonze, Diego

2012-01-01

379

Particle-in-Cell Simulations of the High Frequency Hybrid Instability in Inertial Confiment Fusion Plasmas  

NASA Astrophysics Data System (ADS)

We present results on the laser-plasma interaction near the quarter critical surface under conditions relevant to inertial fusion. Under these conditions, the high frequency hybrid instability (HFHI) where one of the daughter waves have mixed polarization, is likely to be dominant. In fully nonlinear kinetic simulations with the code OSIRIS we show that the spectrum at early time is consistent with theory and the growth rate predicted by HFHI theory is born out by these simulations. We also investigate the saturated electrostatic (and electromagnetic) spectrum for long timescales for both fixed and mobile ions. For high temperatures where the HFHI is dominant the absorption is dominated by the absolutely unstable modes and absorption levels near 40% can occur even below the pure 2wp modes. In these cases, it is possible to excite HFHI modes as long as one is above the Raman threshold. We also investigate in detail the evolution of unstable modes. Nonlinear effects, such as the generation of hot electrons, half harmonics and the excitation of low frequency ion fluctuations, will also be discussed.

Tsung, Frank; Afeyan, B. B.; Mori, W. B.

2010-11-01

380

ANL ITER high-heat-flux blanket-module heat transfer experiments. Fusion Power Program  

SciTech Connect

An Argonne National Laboratory facility for conducting tests on multilayered slab models of fusion blanket designs is being developed; some of its features are described. This facility will allow testing under prototypic high heat fluxes, high temperatures, thermal gradients, and variable mechanical loadings in a helium gas environment. Steady and transient heat flux tests are possible. Electrical heating by a two-sided, thin stainless steel (SS) plate electrical resistance heater and SS water-cooled cold panels placed symmetrically on both sides of the heater allow achievement of global one-dimensional heat transfer across blanket specimen layers sandwiched between the hot and cold plates. The heat transfer characteristics at interfaces, as well as macroscale and microscale thermomechanical interactions between layers, can be studied in support of the ITER engineering design effort. The engineering design of the test apparatus has shown that it is important to use multidimensional thermomechanical analysis of sandwich-type composites to adequately analyze heat transfer. This fact will also be true for the engineering design of ITER.

Kasza, K.E.

1992-02-01

381

The Stability of High Yield, Direct-Drive Targets for Inertial Fusion Energy  

NASA Astrophysics Data System (ADS)

We are investigating laser-driven, direct-drive targets for inertial fusion energy as a contribution to the US High-Average-Power Laser Program. In particular, we are optimizing the stability of high yield ( 400MJ) options based on original NRL designs of Bodner et al. with 2D implosion simulations via LASNEX. We have reduced numerical noise inherent in laser energy deposition and are now able to demonstrate full, time-dependent 2D implosions to ignition with laser ray-trace numerical noise reduced to 1.e-10cm, comparable to that for indirect-drive targets. 2D growth factors are in good agreement with the semi-analytic Betti-Goncharov 1-D model. Present work is directed to stability improvement by optimizing driver pulse shapes. A large initial prepulse ("picket stake") affords adiabat tailoring in the fuel and ablator and offers large reductions in Rayleigh-Taylor growth rates compared with conventional pulse shapes. E.g., at spherical mode numbers l=75-100, growth factors have been reduced from 10.5 to 6.5 e-folds. Application of non-linear saturation models for an initial roughness spectrum suggest a corresponding reduction in late-time shell breakup from 80negligible 2

Perkins, L. John; Tabak, Max; Lindl, John; Bailey, David; Harte, Judith; Schmitt, Andrew; Obenschain, Stephen; Betti, Riccardo

2002-11-01

382

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

NASA Astrophysics Data System (ADS)

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 collaboration space, which includes advanced tools for ad hoc and structured communications, shared applications and displays, enhanced interactivity for remote data access applications, high performance computational services and an improved security environment. The technologies developed should be prototyped and tested on the current generation of experiments and numerical simulation projects. At the same time, such work should maintain a strong focus on the needs of the next generation of mega-projects, ITER and the ILC. Such an effort needs to leverage existing computer science technology and take full advantage of commercial software wherever possible. This paper compares the requirements of FES and HEP, discuss today's solutions, examine areas where more functionality is required, and discuss those areas with sufficient overlap in requirements that joint research into collaborative technologies will increase the benefit to both.

Schissel, D. P.; Gottschalk, E. E.; Greenwald, M. J.; McCune, D.

2006-09-01

383

Performance of large-aperture optical switches for high-energy inertial-confinement fusion lasers.  

PubMed

We describe the design and performance of large-aperture (>30 cm × 30 cm) optical switches that have demonstrated, for the first time to our knowledge, active switching of a high-energy (>5 kJ) optical pulse in an inertial-confinement fusion laser. These optical switches, which consist of a plasma-electrode Pockels cell (PEPC) and a passive polarizer, permit the design of efficient, multipass laser amplifiers. In a PEPC, plasma discharges on the faces of a thin (1-cm) electro-optic crystal (KDP or KD*P) act as highly conductive and transparent electrodes. These plasma electrodes facilitate rapid (<100 ns) and uniform charging of the crystal to the half-wave voltage and discharging back to 0 V. We discuss the operating principles, design, optical performance, and technical issues of a 32 cm × 32 cm prototype PEPC with both KDP and KD*P crystals, and a 37 cm × 37 cm PEPC with a KDP crystal for the Beamlet laser. This PEPC recently switched a 6-kJ, 3-ns pulse in a four-pass cavity. PMID:21060350

Rhodes, M A; Woods, B; Deyoreo, J J; Roberts, D; Atherton, L J

1995-08-20

384

Highly bright X-ray generator using heat of fusion with a specially designed rotating anticathode  

PubMed Central

A new type of rotating anticathode X-ray generator has been developed, in which the electron beam irradiates the inner surface of a U-shaped anticathode (Cu). A high-flux electron beam is focused on the inner surface by optimizing the shape of the bending magnet. The power of the electron beam can be increased to the point at which the irradiated part of the inner surface is melted, because a strong centrifugal force fixes the melted part on the inner surface. When the irradiated part is melted, a large amount of energy is stored as the heat of fusion, resulting in emission of X-rays 4.3 times more brilliant than can be attained by a conventional rotating anticathode. Oscillating translation of the irradiated position on the inner surface during use is expected to be very advantageous for extending the target life. A carbon film coating on the inner surface is considered to suppress evaporation of the target metal and will be an important technique in further realization of highly bright X-ray generation.

Sakabe, N.; Ohsawa, S.; Sugimura, T.; Ikeda, M.; Tawada, M.; Watanabe, N.; Sasaki, K.; Ohshima, K.; Wakatsuki, M.; Sakabe, K.

2008-01-01

385

Performance of large-aperture optical switches for high-energy inertial-confinement fusion lasers  

NASA Astrophysics Data System (ADS)

We describe the design and performance of large-aperture ( greater than 30 cm \\times 30 cm) optical switches that have demonstrated, for the first time to our knowledge, active switching of a high-energy ( greater than 5 kJ) optical pulse in an inertial-confinement fusion laser. These optical switches, which consist of a plasma-electrode Pockels cell (PEPC) and a passive polarizer, permit the design of efficient, multipass laser amplifiers. In a PEPC, plasma discharges on the faces of a thin (1-cm) electro-optic crystal (KDP or KD*P) act as highly conductive and transparent electrodes. These plasma electrodes facilitate rapid ( less than 100 ns) and uniform charging of the crystal to the half-wave voltage and discharging back to 0 V. We discuss the operating principles, design, optical performance, and technical issues of a 32 cm \\times 32 cm prototype PEPC with both KDP and KD*P crystals, and a 37 cm \\times 37 cm PEPC with a KDP crystal for the Beamlet laser. This PEPC recently switched a 6-kJ, 3-ns pulse in a four-pass cavity.

Rhodes, Mark A.; Woods, B.; Deyoreo, J. J.; Roberts, D.; Atherton, L. J.

1995-08-01

386

Multi-sensor fusion system using wavelet-based detection algorithm applied to physiological monitoring under high-G environment  

NASA Astrophysics Data System (ADS)

A significant problem in physiological state monitoring systems with single data channels is high rates of false alarm. In order to reduce false alarm probability, several data channels can be integrated to enhance system performance. In this work, we have investigated a sensor fusion methodology applicable to physiological state monitoring, which combines local decisions made from dispersed detectors. Difficulties in biophysical signal processing are associated with nonstationary signal patterns and individual characteristics of human physiology resulting in nonidentical observation statistics. Thus a two compartment design, a modified version of well established fusion theory in communication systems, is presented and applied to biological signal processing where we combine discrete wavelet transforms (DWT) with sensor fusion theory. The signals were decomposed in time-frequency domain by discrete wavelet transform (DWT) to capture localized transient features. Local decisions by wavelet power analysis are followed by global decisions at the data fusion center operating under an optimization criterion, i.e., minimum error criterion (MEC). We used three signals acquired from human volunteers exposed to high-G forces at the human centrifuge/dynamic flight simulator facility in Warminster, PA. The subjects performed anti-G straining maneuvers to protect them from the adverse effects of high-G forces. These maneuvers require muscular tensing and altered breathing patterns. We attempted to determine the subject's state by detecting the presence or absence of the voluntary anti-G straining maneuvers (AGSM). During the exposure to high G force the respiratory patterns, blood pressure and electroencephalogram (EEG) were measured to determine changes in the subject's state. Experimental results show that the probability of false alarm under MEC can be significantly reduced by applying the same rule found at local thresholds to all subjects, and MEC can be employed as a robust system to the case of defective/jammed local sensors. This implies the feasibility of our system for physiological state monitoring under a unifying criterion by biological information fusion, and provides significant guidance for algorithm development.

Ryoo, Han Chool

2000-06-01

387

Identification of the B1 and B2 subunits of human placental laminin and rat parietal-yolk-sac laminin using antisera specific for murine laminin-beta-galactosidase fusion proteins.  

PubMed Central

Antisera raised against fusion proteins consisting of murine laminin B1 and B2 subunit sequences fused to the C-terminus of Escherichia coli beta-galactosidase were tested for their subunit specificity on Western blots of deglycosylated murine Engelbreth-Holm-Swarm (EHS) laminin. The antisera raised against B2 subunit sequences (anti-XLB2.1 and anti-XLB2.2) bound only to the EHS laminin B2 subunit. One of the antisera raised against B1 subunit sequences (anti-XLB1.2) was specific for the B1 subunit, whereas two others (anti-XLB1.1 and anti-XLB1.3) cross-reacted with the EHS laminin B2 subunit. Gold-labelled heparin-albumin was shown to bind specifically to the A subunit of deglycosylated EHS laminin on Western blots. These reagents were used to identify the homologous subunits in rat parietal-yolk-sac laminin and human placental laminin. The anti-(fusion protein) antisera identified the B1 and B2 subunits of the rat laminin, and these were similar in size to the murine EHS B subunits. Human placental laminin gave bands of 400, 340, 230, 190 and 180 kDa on reducing SDS/PAGE. The anti-(fusion protein) antisera identified the 230 and 190 kDa bands as the B1 and B2 subunits respectively. Gold-labelled heparin-albumin bound to the 400, 340 and 190 kDa bands of human placental laminin and so did not unambiguously identify a single A subunit. The human placental laminin may contain a mixture of isoforms, with alternative subunits substituting for the A subunit. Images Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6.

Brown, J C; Spragg, J H; Wheeler, G N; Taylor, P W

1990-01-01

388

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 3 days 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 6 weeks (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

2014-01-01

389

In vivo expression of GLP-1\\/IgG-Fc fusion protein enhances beta-cell mass and protects against streptozotocin-induced diabetes  

Microsoft Academic Search

Glucagon-like peptide 1 (GLP-1) and its analogue exendin-4 (Ex4) have displayed potent glucose homeostasis-modulating characteristics in type 2 diabetes (T2D). However, there are few reports of effectiveness in type 1 diabetes (T1D) therapy, where there is massive loss of ? cells. We previously described a novel GLP-1 analogue consisting of the fusion of active GLP-1 and IgG heavy chain constant

N Soltani; M Kumar; Y Glinka; G J Prud'Homme; Q Wang

2007-01-01

390

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.

391

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 reactor’s 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

392

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

393

Concept for a high performance MHD airbreathing-IEC fusion rocket  

NASA Astrophysics Data System (ADS)

Previous studies have shown that Single-State-to-Orbit (SSTO) vehicle propellant can be reduced by Magnets-Hydro-Dynamic (MHD) processes that minimize airbreathing propulsion losses and propellant consumption during atmospheric flight, and additional reduction in SSTO propellant is enabled by Inertial Electrostatic Confinement (IEC) fusion, whose more energetic reactions reduce rocket propellant needs. MHD airbreathing propulsion during an SSTO vehicle's initial atmospheric flight phase and IEC fusion propulsion during its final exo-atmospheric flight phase is therefore being explored. Accomplished work is not yet sufficient for claiming such a vehicle's feasibility. But takeoff and propellant mass for an MHD airbreathing and IEC fusion vehicle could be as much as 25 and 40 percent less than one with ordinary airbreathing and IEC fusion; and as much as 50 and 70 percent less than SSTO takeoff and propellant mass with MHD airbreathing and chemical rocket propulsion. .

Froning, H. D.; Miley, G. H.; Nadler, J.; Shaban, Y.; Momota, H.; Burton, E.

2001-02-01

394

The effects of exchange gas temperature and pressure on the beta-layering process in solid deuterium-tritium fusion fuel  

SciTech Connect

It has recently been shown that when solid tritium is confined in an isothermal enclosure, self-heating due to beta decay drives a net sublimation of material from thick, warmer layers to thin, cooler ones, ultimately resulting in layer thickness uniformity. We have observed this process of beta-layering'' in a 50--50 D-T mixture in both cylindrical and spherical enclosures at temperatures from 19.6 K, down to 11.6 K. The measured time constants are found to depend on the {sup 3}He content as suggested by recent theoretical predictions. When using an enclosure having low thermal conductivity, the ultimate layer uniformity is found to be a strong function of the exchange gas pressure. This is due to the presence of thermal convection in the exchange gas and consequent temperature anisotropy at the solid layer surface. 6 refs., 2 figs., 1 tab.

Hoffer, J.K.; Foreman, L.R. (Los Alamos National Lab., NM (USA)); Simpson, J.D.; Pattinson, T.R. (KMS Fusion, Inc., Ann Arbor, MI (USA))

1990-01-01

395

The effects of exchange gas temperature and pressure on the beta-layering process in solid deuterium-tritium fusion fuel  

NASA Astrophysics Data System (ADS)

It has recently been shown that when solid tritium is confined in an isothermal enclosure, self-heating due to beta decay drives a net sublimation of material from thick, warmer layers to thin, cooler ones, ultimately resulting in layer thickness uniformity. We have observed this process of “beta-layering” in a 50-50 D-T mixture in both cylindrical and spherical enclosures at temperatures from 19.6 K, down to 11.6 K. The measured time constants are found to depend on the 3He content as suggested by recent theoretical predictions. When using an enclosure having low thermal conductivity, the ultimate layer uniformity is found to be a strong function of the exchange gas pressure. This is due to the presence of thermal convection in the exchange gas and consequent temperature anisotropy at the solid layer surface.

Hoffer, James K.; Foreman, Larry R.; Simpson, John D.; Pattinson, Ted R.

1990-08-01

396

Genetic analysis of glucosidase II beta-subunit in trimming of high-mannose-type glycans.  

PubMed

Glucosidase II (G-II) is a glycoprotein-processing enzyme that successively cleaves two alpha1,3-linked glucose residues from N-linked oligosaccharides in the endoplasmic reticulum. G-II is a heterodimer whose alpha-subunit contains a glycosidase active site, but the function(s) of the beta-subunit remain poorly defined. We report here an in vivo enzymatic analysis using gene disruptants lacking either the G-II alpha- or beta-subunit in the filamentous fungus Aspergillus oryzae. Using synthetic oligosaccharides as probes, G-II activity of the membranous fraction of the gene disruptants was investigated. The fraction lacking the beta-subunit retained hydrolytic activity toward p-nitrophenyl alpha-D-glucopyranoside but was inactive toward both Glc(2)Man(9)GlcNAc(2) and Glc(1)Man(9)GlcNAc(2). When the fraction containing the beta-subunit was added to the one including the alpha-subunit, the glucosidase activity was restored. These results suggested that the beta-subunit confers the substrate specificity toward di- and monoglucosylated glycans on the glucose-trimming activity of the alpha-subunit. PMID:19395677

Watanabe, Taisuke; Totani, Kiichiro; Matsuo, Ichiro; Maruyama, Jun-ichi; Kitamoto, Katsuhiko; Ito, Yukishige

2009-08-01

397

Archaeal CCA-adding enzymes: central role of a highly conserved beta-turn motif in RNA polymerization without translocation.  

PubMed

The CCA-adding enzyme (tRNA nucleotidyltransferase) builds and repairs the 3' end of tRNA. A single active site adds both CTP and ATP, but the enzyme has no nucleic acid template, and tRNA does not translocate or rotate during C75 and A76 addition. We modeled the structure of the class I archaeal Sulfolobus shibatae CCA-adding enzyme on eukaryotic poly(A) polymerase and mutated residues in the vicinity of the active site. We found mutations that specifically affected C74, C75, or A76 addition, as well as mutations that progressively impaired addition of CCA. Many of these mutations clustered in an evolutionarily versatile beta-turn located between strands 3 and 4 of the nucleotidyltransferase domain. Our mutational analysis confirms and extends recent crystallographic studies of the highly homologous Archaeoglobus fulgidus enzyme. We suggest that the unusual phenotypes of the beta-turn mutants reflect the consecutive conformations assumed by the beta-turn as it presents the discriminator base N73, then C74, and finally C75 to the active site without translocation or rotation of the tRNA acceptor stem. We also suggest that beta-turn mutants can affect nucleotide selection because the growing 3' end of tRNA must be properly positioned to serve as part of the ribonucleoprotein template that selects the incoming nucleotide. PMID:15590678

Cho, Hyundae D; Verlinde, Christophe L; Weiner, Alan M

2005-03-11

398

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

399

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

NASA Astrophysics Data System (ADS)

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 ~50 g/cm3 at peak compression, and fusion gains of ~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 ~2 g/cm2 using two annular beams to implode the target to peak DT densities ~100 g/cm3, followed by a fast-ignition solid ion beam which heats the high-density fuel to thermonuclear temperatures in ~200 ps to start the burn propagation, obtaining gains of ~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 ?R) located at the vertex of the X-target.

Henestroza, Enrique; Grant Logan, B.

2012-07-01

400

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

401

Classification of high resolution imagery based on fusion of multiscale texture features  

NASA Astrophysics Data System (ADS)

In high resolution data classification process, combining texture features with spectral bands can effectively improve the classification accuracy. However, the window size which is difficult to choose is regarded as an important factor influencing overall classification accuracy in textural classification and current approaches to image texture analysis only depend on a single moving window which ignores different scale features of various land cover types. In this paper, we propose a new method based on the fusion of multiscale texture features to overcome these problems. The main steps in new method include the classification of fixed window size spectral/textural images from 3×3 to 15×15 and comparison of all the posterior possibility values for every pixel, as a result the biggest probability value is given to the pixel and the pixel belongs to a certain land cover type automatically. The proposed approach is tested on University of Pavia ROSIS data. The results indicate that the new method improve the classification accuracy compared to results of methods based on fixed window size textural classification.

Liu, Jinxiu; Liu, Huiping; Lv, Ying; Xue, Xiaojuan

2014-03-01

402

Creating highly specific nucleases by fusion of active restriction endonucleases and catalytically inactive homing endonucleases  

PubMed Central

Zinc-finger nucleases and TALE nucleases are produced by combining a specific DNA-binding module and a non-specific DNA-cleavage module, resulting in nucleases able to cleave DNA at a unique sequence. Here a new approach for creating highly specific nucleases was pursued by fusing a catalytically inactive variant of the homing endonuclease I-SceI, as DNA binding-module, to the type IIP restriction enzyme PvuII, as cleavage module. The fusion enzymes were designed to recognize a composite site comprising the recognition site of PvuII flanked by the recognition site of I-SceI. In order to reduce activity on PvuII sites lacking the flanking I-SceI sites, the enzymes were optimized so that the binding of I-SceI to its sites positions PvuII for cleavage of the composite site. This was achieved by optimization of the linker and by introducing amino acid substitutions in PvuII which decrease its activity or disturb its dimer interface. The most specific variant showed a more than 1000-fold preference for the addressed composite site over an unaddressed PvuII site. These results indicate that using a specific restriction enzyme, such as PvuII, as cleavage module, offers an alternative to the otherwise often used catalytic domain of FokI, which by itself does not contribute to the specificity of the engineered nuclease.

Fonfara, Ines; Curth, Ute; Pingoud, Alfred; Wende, Wolfgang

2012-01-01

403

High-performance beam-plasma neutron sources for fusion materials development  

SciTech Connect

The design and performance of a relatively low-cost, plasma-based, 14-MeV deuterium-tritium neutron source for accelerated end-of-life testing of fusion reactor materials are described. An intense flux (up to 5 [times] 10[sup 18] n/m[sup 2][center dot]s) of 14-MeV neutrons is produced in a fully ionized high-density tritium target (n[sub e] [approx] 3 [times] 10[sup 21] m[sup [minus]3]) by injecting a current of 150-keV deuterium atoms. The tritium plasma target and the energetic D[sup +] density produced by D[sup 0] injection are confined in a [<=] 0.16-m-diam column by a linear magnet set, which provides magnetic fields up to 12 T. Energy deposited by transverse injection of neutral beams at the midpoint of the column is transported along the plasma column to the end regions. Three variations of the neutron source design are discussed, differing in the method of control of the energy transport. Emphasis is on the design in which the target plasma density is maintained in a region where electron thermal conduction along the column is the controlling energy-loss process.

Coensgen, F.H.; Casper, T.A.; Correll, D.L.; Damm, C.C.; Futch, A.H.; Logan, B.G.; Molvik, A.W. (Lawrence Livermore National Lab., CA (United States))

1990-10-01

404

Mitigating Laser Imprint in Direct-Drive Inertial Confinement Fusion Implosions with High-Z Dopants  

NASA Astrophysics Data System (ADS)

Nonuniformities seeded by both long- and short-wavelength laser perturbations can grow via Rayleigh-Taylor (RT) instability in direct-drive inertial confinement fusion, leading to performance reduction in low-adiabat implosions. To mitigate the effect of laser imprinting on target performance, spherical RT experiments have been performed on OMEGA using Si- or Ge-doped plastic targets in a cone-in-shell configuration. Compared to a pure plastic target, radiation preheating from these high-Z dopants (Si/Ge) increases the ablation velocity and the standoff distance between the ablation front and laser-deposition region, thereby reducing both the imprinting efficiency and the RT growth rate. Experiments showed a factor of 2-3 reduction in the laser-imprinting efficiency and a reduced RT growth rate, leading to significant (3-5 times) reduction in the ?rms of shell ?R modulation for Si- or Ge-doped targets. These features are reproduced by radiation-hydrodynamics simulations using the two-dimensional hydrocode DRACO.

Hu, S. X.; Fiksel, G.; Goncharov, V. N.; Skupsky, S.; Meyerhofer, D. D.; Smalyuk, V. A.

2012-05-01

405

Mitigating laser imprint in direct-drive inertial confinement fusion implosions with high-Z dopants.  

PubMed

Nonuniformities seeded by both long- and short-wavelength laser perturbations can grow via Rayleigh-Taylor (RT) instability in direct-drive inertial confinement fusion, leading to performance reduction in low-adiabat implosions. To mitigate the effect of laser imprinting on target performance, spherical RT experiments have been performed on OMEGA using Si- or Ge-doped plastic targets in a cone-in-shell configuration. Compared to a pure plastic target, radiation preheating from these high-Z dopants (Si/Ge) increases the ablation velocity and the standoff distance between the ablation front and laser-deposition region, thereby reducing both the imprinting efficiency and the RT growth rate. Experiments showed a factor of 2-3 reduction in the laser-imprinting efficiency and a reduced RT growth rate, leading to significant (3-5 times) reduction in the ?(rms) of shell ?R modulation for Si- or Ge-doped targets. These features are reproduced by radiation-hydrodynamics simulations using the two-dimensional hydrocode DRACO. PMID:23003051

Hu, S X; Fiksel, G; Goncharov, V N; Skupsky, S; Meyerhofer, D D; Smalyuk, V A

2012-05-11

406

Thelytokous Parthenogenesis in Unmated Queen Honeybees (Apis mellifera capensis): Central Fusion and High Recombination Rates  

PubMed Central

The subspecies of honeybee indigenous to the Cape region of South Africa, Apis mellifera capensis, is unique because a high proportion of unmated workers can lay eggs that develop into females via thelytokous parthenogenesis involving central fusion of meiotic products. This ability allows pseudoclonal lineages of workers to establish, which are presently widespread as reproductive parasites within the honeybee populations of South Africa. Successful long-term propagation of a parthenogen requires the maintenance of heterozygosity at the sex locus, which in honeybees must be heterozygous for the expression of female traits. Thus, in successful lineages of parasitic workers, recombination events are reduced by an order of magnitude relative to meiosis in queens of other honeybee subspecies. Here we show that in unmated A. m. capensis queens treated to induce oviposition, no such reduction in recombination occurs, indicating that thelytoky and reduced recombination are not controlled by the same gene. Our virgin queens were able to lay both arrhenotokous male-producing haploid eggs and thelytokous female-producing diploid eggs at the same time, with evidence that they have some voluntary control over which kind of egg was laid. If so, they are able to influence the kind of second-division meiosis that occurs in their eggs post partum.

Oldroyd, Benjamin P.; Allsopp, Michael H.; Gloag, Rosalyn S.; Lim, Julianne; Jordan, Lyndon A.; Beekman, Madeleine

2008-01-01

407

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 re