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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.; 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

2

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

3

High poloidal beta equilibria in the Tokamak Fusion Test Reactor limited by a natural inboard poloidal field null  

SciTech Connect

Recent operation of the Tokamak Fusion Test Reactor (TFTR) (Plasma Phys. Controlled Nucl. Fusion Research {bold 1}, 51 (1986)) has produced plasma equilibria with values of {Lambda}{equivalent to}{beta}{sub {ital p} eq}+{ital l}{sub {ital i}}/2 as large as 7, {epsilon}{beta}{sub {ital p} dia}{equivalent to}2{mu}{sub 0}{epsilon}{l angle}{ital p}{sub {perpendicular}}{r angle}/{l angle}{l angle}{ital B}{sub {ital p}}{r angle}{r angle}{sup 2} as large as 1.6, and Troyon normalized diamagnetic beta (Plasma Phys. Controlled Fusion {bold 26}, 209 (1984); Phys. Lett. {bold 110A}, 29 (1985)), {beta}{sub {ital N}dia}{equivalent to}10{sup 8}{l angle}{beta}{sub {ital t}{perpendicular}}{r angle}{ital aB}{sub 0}/{ital I}{sub {ital p}} as large as 4.7. When {epsilon}{beta}{sub {ital p} dia}{approx gt}1.25, a separatrix entered the vacuum chamber, producing a naturally diverted discharge that was sustained for many energy confinement times, {tau}{sub {ital E}}. The largest values of {epsilon}{beta}{sub {ital p}} and plasma stored energy were obtained when the plasma current was ramped down prior to neutral beam injection. The measured peak ion and electron temperatures were as large as 24 and 8.5 keV, respectively. Plasma stored energy in excess of 2.5 MJ and {tau}{sub {ital E}} greater than 130 msec were obtained. Confinement times of greater than 3 times that expected from L-mode predictions have been achieved. The fusion power gain {ital Q}{sub DD} reached a value of 1.3{times}10{sup {minus}3} in a discharge with {ital I}{sub {ital p}}=1 MA and {epsilon}{beta}{sub {ital p} dia}=0.85. A large, sustained negative loop voltage during the steady-state portion of the discharge indicates that a substantial noninductive component of {ital I}{sub {ital p}} exists in these plasmas. Transport code analysis indicates that the bootstrap current constitutes up to 65% of {ital I}{sub {ital p}}.

Sabbagh, S.A.; Gross, R.A.; Mauel, M.E.; Navratil, G.A. (Department of Applied Physics, Columbia University, New York, New York 10027 (USA)); Bell, M.G.; Bell, R.; Bitter, M.; Bretz, N.L.; Budny, R.V.; Bush, C.E.; Chance, M.S.; Efthimion, P.C.; Fredrickson, E.D.; Hatcher, R.; Hawryluk, R.J.; Hirshman, S.P.; Janos, A.C.; Jardin, S.C.; Jassby, D.L.; Manickam, J.; McCune, D.C.; McGuire, K.M.; Medley, S.S.; Mueller, D.; Nagayama, Y.; Owens, D.K.; Okabayashi, M.; Park, H.K.; Ramsey, A.T.; Stratton, B.C.; Synakowski, E.J.; Taylor, G.; Wieland, R.M.; Zarnstorff, M.C. (Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (USA)); Kesner, J.; Marmar, E.S.; Terry, J.L. (MIT Plasma Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (USA))

1991-08-01

4

Bacterial luciferase alpha beta fusion protein is fully active as a monomer and highly sensitive in vivo to elevated temperature.  

PubMed Central

A 2.2-kilobase-pair (kbp) DNA fragment from Vibrio harveyi contains the luxA and luxB genes separated by a 26-base-pair (bp) intergenic region. The two genes were converted to a single open reading frame by site-specific mutagenesis. A full-length fusion protein is obtained when the new gene is placed under transcriptional control of a T7 promoter in Escherichia coli. Bioluminescence of colonies containing the gene fusion is 0.002% of the wild-type luciferase [alkanal monooxygenase (FMN-linked); alkanal, reduced-FMN:oxygen oxidoreductase (1-hydroxylating, luminescing), EC 1.14.14.3] at 37 degrees C. Growth at 23 degrees C results in a greater than 50,000-fold increase in light emission in cells containing fusion protein, whereas only a 3-fold increase in observed with cells containing the luxAB dicistron. Purified fusion protein isolated from E. coli grown at 19 degrees C exists in both monomeric and dimeric forms with specific bioluminescence activities comparable to the heterodimeric wild-type enzyme at 23 degrees C and 37 degrees C. These findings show that the alpha beta fusion polypeptide is functional as a monomer and suggest that its folding is drastically affected at elevated temperature. We hypothesize that the two-subunit bacterial luciferase may have evolved from a monomer as a result of a temperature increase in the environment. Images PMID:2671993

Escher, A; O'Kane, D J; Lee, J; Szalay, A A

1989-01-01

5

High Beta Tokamaks  

SciTech Connect

Perhaps the ideal tokamak would have high {beta} ({beta} {approx}> 1) and classical confinement. Such a tokamak has not been found, and we do not know if one does exist. We have searched for such a possibility, so far without success. In 1990, we obtained analytic equilibrium solutions for large aspect ratio tokamaks at {beta} {approx} {Omicron}(1) [1]. These solutions and the extension at high {beta} poloidal to finite aspect ratio [2] provided a basis for the study of high {beta} tokamaks. We have shown that these configurations can be stable to short scale MHD modes [3], and that they have reduced neoclassical transport [4]. Microinstabilities (such as the {del}T{sub i} mode) seem to be stabilized at high {beta} [5] - this is due to the large local shear [3] and the magnetic well. We have some concerns about modes associated with the compressional branch which may appear at high {beta}. Bill Dorland and Mike Kotschenreuther have studied this issue and our concerns may be unfounded. It is certainly tantalizing, especially given the lowered neoclassical transport values, that these configurations could have no microinstabilities and, one could assume, no anomalous transport. Unfortunately, while this work is encouraging, the key question for high {beta} tokamaks is the stability to large scale kink modes. The MHD {beta} limit (Troyon limit) for kink modes at large aspect ratio is problematically low. There is ample evidence from computations that the limit exists. However, it is not known if stable equilibria exist at much higher {beta}--none have been found. We have explored this question in the asymptotic high {beta} poloidal limit. Unfortunately, we are unable to find stable equilibrium and also unable to show that they don't exist. The results of these calculations will be published when a more definitive answer is found.

Cowley, S.

1998-11-14

6

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

7

Wall-confined high beta spheromak  

SciTech Connect

The spheromak could be extended into the high beta regime by supporting the pressure on flux-conserving walls, allowing the plasma to be in a Taylor state with zero pressure gradient and thus stable to ideal and resistive MHD. The concept yields a potentially attractive, pulsed reactor which would require no external magnets. The flux conserver would be shaped to be stable to the tilt and shift instabilities. We envision a plasma which is ohmically ignited at low beta, with the kinetic pressure growing to beta > 1 by fueling from the edge. The flux conserver would be designed such that the magnetic decay time = the fusion burn time. The thermal capacity of the flux conserver and blanket would exceed the fusion yield per discharge, so that they can be cooled steadily. Ignition is estimated to require minimum technology: 30-100 MJ of pulsed power applied at a 0.5 GW rate generates an estimated bum yield > 1 GJ. The concept thus provides an alternate route to a fusion plasma that is MHD stable at high beta, yielding a reactor that is simple and cheap. The major confinement issue is transport due to grad(T), e.g. driven by high beta modes related to the ITG instability.

Fowler, T.K.; Hopper, E.B.; Moir, R.W.; Pearlstein, L.D.

1998-03-16

8

Achieving high Q{sub DD} operation in high poloidal beta discharges in TFTR  

SciTech Connect

Tokamak operation at high poloidal beta ({var_epsilon}{beta}{sub p} {approximately} 1, {var_epsilon}{quadruple_bond} a/R) offers several important advantages to future fusion reactors: low plasma current, high bootstrap current fraction, and the possibility of improved confinement due to equilibrium modification. However, since the plasma current is low at high {var_epsilon}{beta}{sub p}, the achievement of high fusion reactivity generally requires operation at a high Troyon-normalized beta, {beta}{sub N} {quadruple_bond} 10{sup 8} <{beta}> aB{sub t}/I{sub p}, and a high L-mode normalized confinement, H {quadruple_bond} {tau}E/{tau}E,ITER{sub p}. The TFTR high poloidal beta experiments have explored this advanced operating regime in reactor-like conditions, and we have demonstrated techniques that can be used to achieve high Q{sub DD} at high {var_epsilon}{beta}{sub p}. In this paper, we present new results showing that Q{sub DD} as high as 1.3 {times} 10{sup {minus}3}, can be achieved at {var_epsilon}{beta}{sub p} {approximately} 0.85 using transient current profile modification techniques, which nevertheless, maintain high Q{sub DD} for an alpha slowingdown time. Future DT experiments in TFTR will be able to study collective alpha-particle physics in discharges having high {var_epsilon}{beta}{sub p}, high {beta}{sub N}, and evolving current profiles. This paper also illustrates the need for steady-state current profile control to sustain high Q{sub DD} at high {var_epsilon}{beta}{sub p} by presenting recent observations of long-pulse, high {beta}{sub p} discharges in which the current density is allowed to relax naturally to a broad, bootstrap-dominated profile.

Mauel, M.E.; Navratil, G.A.; Sabbagh, S.A. [Columbia Univ., New York, NY (United States). Plasma Physics Lab.; Bell, M.G.; Bell, R.; Budny, R.V.; Bush, C.E.; Cavallo, A.; Chance, M.S.; Efthimion, P.C.; Fredrickson, E.D.; 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

1992-09-01

9

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

10

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

11

High Level Information Fusion (HLIF) with nested fusion loops  

NASA Astrophysics Data System (ADS)

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

Woodley, Robert; Gosnell, Michael; Fischer, Amber

2013-05-01

12

Beta decay of highly charged ions  

NASA Astrophysics Data System (ADS)

Ion storage rings and ion traps provide the very first opportunity to address nuclear beta decay under conditions prevailing in hot stellar plasmas during nucleosynthesis, i.e. at high atomic charge states. Experiments are summarized that were performed in this field during the last decade at the ion storage-cooler ring ESR in Darmstadt. Special emphasis is given to the first observation of bound-state beta decay, where the created electron remains bound in an inner orbital of the daughter atom. The impact of this specific ‘stellar’ decay mode for s-process nucleosynthesis as well as for nuclear ‘eon clocks’ is outlined. Finally, a new technique, single-ion decay spectroscopy, is presented, where one observes two-body beta decay characteristics (i.e. orbital electron capture or bound-state beta decay) of highly charged, single ions for well-defined nuclear and atomic quantum states of both the mother and the daughter ion.

Bosch, Fritz

2006-11-01

13

Beta decay of highly charged ions  

NASA Astrophysics Data System (ADS)

Ion storage rings and ion traps provide the very first opportunity to address nuclear beta decay under conditions prevailing in hot stellar plasmas during nucleosynthesis, i.e. at high atomic charge states. Experiments are summarized that were performed in this field during the last decade at the ion storage-cooler ring ESR in Darmstadt. Special emphasis is given to the first observation of bound-state beta decay, where the created electron remains bound in an inner orbital of the daughter atom. The impact of this specific 'stellar' decay mode for s-process nucleosynthesis as well as for nuclear `eon clocks' is outlined. Finally, a new technique, single-ion decay spectroscopy, is presented, where one observes two-body beta decay characteristics (i.e. orbital electron capture or bound-state beta decay) of highly charged, single ions for well-defined nuclear and atomic quantum states of both the mother — and the daughter — ion.

Bosch, Fritz

14

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

15

Fusion of platelet-derived growth receptor {beta} to a novel ets-like gene, tel, in chronic myelomonocytic leukemia with t(5;12) chromosomal translocation  

SciTech Connect

Chronic myelomonocytic leukemia (CMML) is a myelodysplastic syndrome characterized by abnormal clonal myeloid proliferation, and by progression to acute myelogenous leukemia (AML). A recently recognized subgroup of CMML has a t(5;12) (q33;p13) balanced translocation. Fluorescence in situ hybridization (FISH) localized the translocation breakpoint near the CSF1 receptor (CSF1R) locus on chromosome 5q. Pulsed-field gel electrophoresis confirmed rearrangements near CSF1R, but involvement of CSF1R itself was excluded. Southern blotting showed a rearrangement within the closely linked PDGF receptor {beta} (PDGFR{beta}) gene. Ribonuclease protection assays localized the translocation breakpoint to nucleotide 1766 in PDGFR{beta} RNA. Anchored PCR was used to identify the chromosome 12 fusion partner, a novel ets-like protein, tel. Tel contains a highly conserved carboxy terminal ets-like DNA-binding domain, and an amino terminal domain with a predicted helix-loop-helix (HLH) secondary structure. The consequence of the t(5;12) translocation is fusion of the tel HLH domain to the PDGFR{beta} transmembrane and tyrosine kinase domains. The tel HLH domain may contribute a dimerization motif which serves to constitutively activate PDGFR{beta} tyrosine kinase activity. The tel-PDGFR{beta} fusion demonstrates the oncogenic potential of PDGFR{beta}, and may provide a paradigm for early events in the pathogenesis of AML.

Golub, T.; Barker, G.; Gilliland, D.G. [Harvard Medical School, Boston, MA (United States)] [and others

1994-09-01

16

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

17

Numerical models for high beta magnetohydrodynamic flow  

SciTech Connect

The fundamentals of numerical magnetohydrodynamics for highly conducting, high-beta plasmas are outlined. The discussions emphasize the physical properties of the flow, and how elementary concepts in numerical analysis can be applied to the construction of finite difference approximations that capture these features. The linear and nonlinear stability of explicit and implicit differencing in time is examined, the origin and effect of numerical diffusion in the calculation of convective transport is described, and a technique for maintaining solenoidality in the magnetic field is developed. Many of the points are illustrated by numerical examples. The techniques described are applicable to the time-dependent, high-beta flows normally encountered in magnetically confined plasmas, plasma switches, and space and astrophysical plasmas. 40 refs.

Brackbill, J.U.

1987-01-01

18

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

PubMed

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

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

2009-07-01

19

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

SciTech Connect

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

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

1981-01-01

20

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

21

Ballooning instability precursors to high {beta} disruptions  

SciTech Connect

Strongly ballooning modes have been found as precursors to high {beta} disruptions on TFTR. The modes are typically localized to a region spanning about 60{degree} in the toroidal direction. The toroidal localization is associated with lower frequency, global Magneto-Hydro-Dynamic (MHD) activity, typically an ideal n = 1 kink mode. They have moderate to high frequency (f = 10--20 f{sub rot}), implying toroidal mode numbers in the range n = 10--20. The growth rates for the modes are large, of order 10{sup 4}/sec.

Fredrickson, E.D.; McGuire, K.M.; Chang, Z.Y. [and others

1995-12-01

22

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

Microsoft Academic Search

The goal of the education and outreach activities of the Hampton University Center for Fusion Research and Training (HU CFRT) is to create a high school-to-Ph.D. pipeline in plasma physics, fusion science, and related sciences for underrepresented minorities and female students. The HU CFRT Summer High School Fusion Research Workshop is an integral component of this pipeline. This workshop has

Alkesh Punjabi

2005-01-01

23

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

E-print Network

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

24

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

SciTech Connect

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. The author considers a number of fuel combinations that could be operated in such low-beta reactor systems and looks upon the relevant fuel reserves. The {open_quotes}classical{close_quotes} D-T-Li cycle will be used as a standard and is extensively discussed therefore. It could supply most of mankind`s future long-term power needs - but only on condition that the required lithium fuel can be extracted from seawater at reasonable expenses. The estimated land-bound lithium reserves are too small to that end, they will last for about 500 years at most, depending on forecasts of future energy consumption and on assumptions about exploitable resources. Recovery of lithium from seawater would extend the possible range by a factor of 300 or so, provided that extraction technologies which are at present available in the laboratory, could be extended to a very large and industrial scale. Deuterium is abundant on earth but D-D fusion is difficult, if not impossible, to be achieved in the low-beta systems presently investigated for D-T fusion. The same arguments apply to so-called {open_quotes}advanced{close_quotes} concepts, such as the D-{sup 3}He and the D-{sup 6}Li cycles. 37 refs., 1 fig., 1 tab.

Eckhartt, D.

1995-12-01

25

Fudge: a high-bandwidth fusion diagnostic of the NIF  

SciTech Connect

Diagnostics for the National Ignition Facility (NIF)/Inertial Confinement Fusion (ICF) program must include good characterization of the fusion source. Ideally, diagnostics would measure the spatially-resolved history of the fusion reaction rate and temperature. Existing diagnostics can satisfy this goal only partially. One class of new techniques that could play a major role in high-yield diagnostics is measurements based on fusion {gamma} rays. The Fusion Diagnostic Gamma Experiment (FUDGE) can be used to perform energy-resolved measurements of (D,T) fusion reaction rates This diagnostic is based on the 16 7-MeV {gamma} rays that are produced by (D,T) fusion. The {gamma} rays are free of spectral dispersion and can be detected with a high bandwidth Cherenkov detector. A simple magnetic monochromator selects signals from the 16 7-MeV {gamma} rays and reduces background signals from non-fusion {gamma} rays.

Moran, M. J., LLNL

1998-06-02

26

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

E-print Network

Fusion energy · Fusion powers the Sun, and all stars, in which light nuclei fuse together at high temperatures (15 million degrees) releasing a large amount of energy. · The aim of fusion research is to use fusion to produce power on earth. · The most promising approach to fusion power is based on the `tokamak

27

Down-regulation of alpha v/beta 3 integrin via misrouting to lysosomes by overexpression of a beta 3Lamp1 fusion protein.  

PubMed Central

We present a general strategy for the dominant negative reduction in the levels of type-1 membrane-bound heterodimeric proteins within the secretory pathway through fusion of the soluble ectodomain of one of the partners to the transmembrane-cytosolic tail of the lysosomal protein Lamp1. Thus, in human embryonic kidney (HEK)-293 cells, overexpression of an integrin beta 3Lamp1 chimera resulted in a drastic reduction of its endogenous partner, the integrin alpha v subunit. The mechanism involves the formation in the endoplasmic reticulum of a alpha v/beta 3Lamp1 complex that is subsequently sorted towards a lysosomal/endosomal degradation pathway. The specificity of this approach is afforded by the invariance in the levels of the endogenous integrins alpha 5 and beta1 as compared with control cells. Conversely overexpression of integrin beta 3 in HEK-293 cells led to an increased level of alpha v beta 3 at the cell surface. Functionally beta 3Lamp1 and beta 3 overexpressors exhibit decreased and increased adhesion to vitronectin, respectively, as well as diminished cellular aggregation. The application of this technology should enable the analysis of the functional importance of homodimers or heterodimers in the cell types of choice and the identification of novel partner proteins by proteomic approaches. PMID:12444923

Conesa, Magali; Prat, Annik; Mort, John S; Marvaldi, Jacques; Lissitzky, Jean-Claude; Seidah, Nabil G

2003-01-01

28

Down-regulation of alpha v/beta 3 integrin via misrouting to lysosomes by overexpression of a beta 3Lamp1 fusion protein.  

PubMed

We present a general strategy for the dominant negative reduction in the levels of type-1 membrane-bound heterodimeric proteins within the secretory pathway through fusion of the soluble ectodomain of one of the partners to the transmembrane-cytosolic tail of the lysosomal protein Lamp1. Thus, in human embryonic kidney (HEK)-293 cells, overexpression of an integrin beta 3Lamp1 chimera resulted in a drastic reduction of its endogenous partner, the integrin alpha v subunit. The mechanism involves the formation in the endoplasmic reticulum of a alpha v/beta 3Lamp1 complex that is subsequently sorted towards a lysosomal/endosomal degradation pathway. The specificity of this approach is afforded by the invariance in the levels of the endogenous integrins alpha 5 and beta1 as compared with control cells. Conversely overexpression of integrin beta 3 in HEK-293 cells led to an increased level of alpha v beta 3 at the cell surface. Functionally beta 3Lamp1 and beta 3 overexpressors exhibit decreased and increased adhesion to vitronectin, respectively, as well as diminished cellular aggregation. The application of this technology should enable the analysis of the functional importance of homodimers or heterodimers in the cell types of choice and the identification of novel partner proteins by proteomic approaches. PMID:12444923

Conesa, Magali; Prat, Annik; Mort, John S; Marvaldi, Jacques; Lissitzky, Jean-Claude; Seidah, Nabil G

2003-03-01

29

Experimental verification of beta-decay-driven sublimation in deuterium-tritium ice held in spherical fusion targets  

NASA Astrophysics Data System (ADS)

A nonuniform layer of deuterium-tritium (DT) ice inside a spherical inertial confinement fusion (ICF) target held in an isothermal cryogenic environment should be driven toward uniformity by the beta-decay heat of the tritium. Experiments have been performed at KMS fusion to verify this hypothesis. Two major conclusions may be drawn from the initial results: (1) the beta decay of the tritium does deposit energy in the target, as evidenced by melting of DT ice when the target is well insulated from its surroundings, and (2) solid layers of DT ice sublime because of beta-decay heat. Both conclusions are reinforced by companion studies with nonradioactive hydrogen-deuterium (HD) ice in similar targets held under similar experimental conditions.

Mruzek, M. T.; Musinski, D. L.; Ankney, J. S.

1988-04-01

30

Ru-catalyzed highly enantioselective hydrogenation of beta-alkyl-substituted beta-(acylamino)acrylates.  

PubMed

Highly enantioselective hydrogenation of beta-alkyl-substituted (E)-beta-(acylamino)-acrylates catalyzed by Ru((R)-Xyl-P-Phos)(C(6)H(6))Cl(2) complex (cat. 1c) was achieved in up to 99.7% ee. Moderate to good enantioselectivities in the hydrogenation of corresponding (Z)-isomers in the presence of [Rh((R)-Xyl-P-Phos)(COD)]BF(4) (cat. 2c) were also obtained. The results demonstrated that the electronic and steric properties of the dipyridylphosphine ligands as well as the different transition metal ions have significant influences on the catalytic properties in the hydrogenation of beta-(acylamino)acrylates. PMID:12636424

Wu, Jing; Chen, Xuanhua; Guo, Rongwei; Yeung, Chi-hung; Chan, Albert S C

2003-03-21

31

High temperature experiment for accelerator inertial fusion  

SciTech Connect

The High Temperature Experiment (HTE) is intended to produce temperatures of 50 to 100 eV in solid density targets driven by heavy ion beams from a multiple beam induction linac. The fundamental variables (particle species, energy, number of beamlets, current and pulse length) must be fixed to achieve the temperature at minimum cost, subject to criteria of technical feasibility and relevance to the development of a Fusion Driver. The conceptual design begins with an assumed (radiation-limited) target temperature and uses limitations due to particle range, beamlet perveance, and target disassembly to bound the allowable values of mass number (A) and energy (E). An accelerator model is then applied to determine the minimum length accelerator, which is a guide to total cost. The accelerator model takes into account limits on transportable charge, maximum gradient, core mass per linear meter, and head-to-tail momentum variation within a pulse.

Lee, E.P.

1985-05-01

32

Stability of high. beta. large aspect ratio tokamaks  

SciTech Connect

High {beta}({beta}{much gt} {epsilon}/q{sup 2}) large aspect ratio ({epsilon} {much gt} 1) tokamak equilibria are shown to be always stable to ideal M.H.D. modes that are localized about a flux surface. Both the ballooning and interchange modes are shown to be stable. This work uses the analytic high {beta} large aspect ratio tokamak equilibria developed by Cowley et.al., which are valid for arbitrary pressure and safety factor profiles. The stability results make no assumption about these profiles or the shape of the boundary. 14 refs., 4 figs.

Cowley, S.C.

1991-10-01

33

Structure-retention correlation of isomeric bile acids in inclusion high-performance liquid chromatography with methyl beta-cyclodextrin.  

PubMed

The structure-retention correlation of various C24 bile acid isomers was studied by the addition of methyl beta-cyclodextrin (Me-beta-CD) to mobile phases in reversed-phase high-performance liquid chromatography (HPLC). The compounds examined include a series of monosubstituted bile acids related to cholanoic acids differing from one another in the position and configuration of an oxygen-containing function (hydroxyl or oxo group) at the position C-3, C-6, C-7, or C-12 and the stereochemistry of the A/B-ring fusion (trans 5 alpha-H and cis 5 beta-H) in the steroid nucleus. The inclusion HPLC with Me-beta-CD was also applied to biologically important 4 beta- and 6-hydroxylated bile acids substituted by three to four hydroxyl groups in the 5 beta-steroid nucleus. These bile acid samples were converted into their fluorescence prelabeled 24-pyrenacyl ester derivatives and chromatographed on a Capcell Pak C18 column eluted with methanol-water mixtures in the presence or absence of 5 mM Me-beta-CD. The effects of Me-beta-CD on the retentions of each compound were correlated quantitatively to the decreasing rate of capacity factors and the relative strength of host-guest interactions. On the basis of the retention data, specific and nonspecific hydrogen-bonding interactions between the bile acids and the Me-beta-CD were discussed. PMID:9470179

Momose, T; Yamaguchi, Y; Iida, T; Goto, J; Nambara, T

1998-01-01

34

High poloidal beta equilibria in TFTR limited by a natural inboard poloidal field null  

SciTech Connect

Recent operation of the Tokamak Fusion Test Reactor TFTR, has produced plasma equilibria with values of {Lambda} {triple bond} {beta}{sub p eq} + l{sub i}/2 as large as 7, {epsilon}{beta}{sub p dia} {triple bond} 2{mu}{sub 0}{epsilon}/{much lt}B{sub p}{much gt}{sup 2} as large as 1.6, and Troyon normalized diamagnetic beta, {beta}{sub N dia} {triple bond} 10{sup 8}<{beta}{sub t}{perpendicular}>aB{sub 0}/I{sub p} as large as 4.7. When {epsilon}{beta}{sub p dia} {approx gt} 1.25, a separatrix entered the vacuum chamber, producing a naturally diverted discharge which was sustained for many energy confinement times, {tau}{sub E}. The largest values of {epsilon}{beta}{sub p} and plasma stored energy were obtained when the plasma current was ramped down prior to neutral beam injection. The measured peak ion and electron temperatures were as large as 24 keV and 8.5 keV, respectively. Plasma stored energy in excess of 2.5 MJ and {tau}{sub E} greater than 130 msec were obtained. Confinement times of greater than 3 times that expected from L-mode predictions have been achieved. The fusion power gain. Q{sub DD}, reached a values of 1.3 {times} 10{sup {minus}3} in a discharge with I{sub p} = 1 MA and {epsilon}{beta}{sub p dia} = 0.85. A large, sustained negative loop voltage during the steady state portion of the discharge indicates that a substantial non-inductive component of I{sub p} exists in these plasmas. Transport code analysis indicates that the bootstrap current constitutes up to 65% of I{sup p}. Magnetohydrodynamic (MHD) ballooning stability analysis shows that while these plasmas are near, or at the {beta}{sub p} limit, the pressure gradient in the plasma core is in the first region of stability to high-n modes. 24 refs., 10 figs.

Sabbagh, S.A.; Gross, R.A.; Mauel, M.E.; Navratil, G.A. (Columbia Univ., New York, NY (United States). Dept. of Applied Physics); Bell, M.G.; Bell, R.; Bitter, M.; Bretz, N.L.; Budny, R.V.; Bush, C.E.; Chance, M.S.; Efthimion, P.C.; Fredrickson, E.D.; Hatcher, R.; Hawryluk, R.J.; Hirshman, S.P.; Janos, A.C.; Jardin, S.C.; Jassby, D.L.; Manickam, J.; McCune, D.C.; McGuire, K.M.; Medley, S.S.; Mueller, D.; Nagayama, Y.; Ow

1991-07-01

35

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

36

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

37

MHD stable high beta spheromak equilibrium  

SciTech Connect

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

Marklin, G.J.

1989-01-01

38

High dynamic range fusion for enhanced vision  

NASA Astrophysics Data System (ADS)

Fusing multispectral images, Enhanced Vision (EV) has been proven helpful to improve pilot's Situation Awareness (SA) under Degraded Vision Environment (DVE), such as low visibility or adverse observation conditions, which caused by fog, dust, weak light, backlighting, etc. Numerous methods are applied to enhance and fuse optical and infrared (IR) images for visual details to provide pilot with enough information as far as possible. However, most existing optical and IR imaging devices, for their inherent defects, fail to acquire wide span of light and only generate Low Dynamic Range images (LDR, Dynamic Range: range between the lightest and darkest areas), which causes the loss of useful details. Normal display devices can't reveal HDR details as well. The proposed paper introduces and expands High Dynamic Range (HDR) technologies to fuse optical and IR images, which has rarely been involved in the study of HDR Imaging to our knowledge, for Enhanced Vision to better pilot's Situation Awareness. Two major problems should be discussed. (1) The way to generate fused image with HDR information under DVE. (2) The method to effectively display fused HDR image with normal LDR monitors. Aiming at application environment, HDR fusion scheme is proposed and relevant methods are explored. The experimental results prove that our scheme is effective and would be beneficial to enhancing pilot's Situation Awareness under DVE.

Liu, Yuchi; Li, Yipeng; Dai, Qionghai

2012-06-01

39

Kinetics of the coupled reaction catalysed by a fusion protein of beta-galactosidase and galactose dehydrogenase.  

PubMed

The mechanistic implications of the kinetic behaviour of a fusion protein of beta-galactosidase and galactose dehydrogenase have been analysed in view of predictions based on experimentally determined kinetic parameter values for the galactosidase and dehydrogenase activities of the protein. The results show that the time course of galactonolactone formation from lactose in the coupled reaction catalysed by the fusion protein can be most satisfactorily accounted for in terms of a free-diffusion mechanism when consideration is given to the mutarotation of the reaction intermediate galactose. It is concluded that no tenable kinetic evidence is available to support the proposal that the fusion protein catalyses galactonolactone formation from lactose by a mechanism involving channelling of galactose. PMID:11690652

Pettersson, H; Pettersson, G

2001-10-18

40

Reaching high poloidal beta at Greenwald density with internal transport barrier close to full noninductive current drive.  

PubMed

In the ASDEX Upgrade tokamak, high poloidal beta up to beta(pol) = 3 at the Greenwald density with H-mode confinement has been reached. Because of the high beta, the plasma current is driven almost fully noninductively, consisting of 51% bootstrap and 43% neutral beam driven current. To reach these conditions the discharge is operated at low plasma current ( I(P) = 400 kA) and high neutral beam heating power ( P(NBI) = 10 MW). The discharge combines an edge (H mode) and internal transport barrier at high densities without confinement-limiting MHD activities. The extrapolation to higher plasma currents may offer a promising way for an advanced scenario based fusion reactor. PMID:11497949

Hobirk, J; Wolf, R C; Gruber, O; Gude, A; Günter, S; Kurzan, B; Maraschek, M; McCarthy, P J; Meister, H; Peeters, A G; Pereverzev, G V; Stober, J; Treutterer, W

2001-08-20

41

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

SciTech Connect

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

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

2007-06-25

42

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

43

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

44

High-temperature plasmas in a tokamak fusion test reactor  

Microsoft Academic Search

Neutral-beam heating of plasmas in the Tokamak Fusion Test Reactor at low preinjection densities (n\\/sub e\\/(0)approx. =10¹⁹ m⁻³) were characterized by T\\/sub e\\/(0) = 6.5 keV, T\\/sub i\\/(0) = 20 keV, n\\/sub e\\/(0) = 7 x 10¹⁹ m⁻³, tau\\/sub E\\/ = 170 msec, ..beta..\\/sub t\\/\\/sub h\\/\\/sub e\\/\\/sub t\\/\\/sub a\\/ = 2, and a d(d,n)³He neutron emission rate of 10¹⁶ sec⁻¹.

J. D. Strachan; M. Bitter; A. T. Ramsey; M. C. Zarnstorff; V. Arunasalam; M. G. Bell; N. L. Bretz; R. Budny; C. E. Bush; S. L. Davis; P. Efthimion; R. Fonck; E. Fredrickson; H. Furth; R. Goldston; L. Grisham; B. Grek; R. Hawryluk; W. Heidbrink; H. Hendel; K. Hill; H. Hsuan; K. Jaehnig; D. Jassby; F. Jobes; D. Johnson; L. Johnson; R. Kaita; J. Kampershroer; R. Knize; T. Kozub; B. LeBlanc; F. Levinton; P. La Marche; D. Manos; D. Mansfield; K. McGuire; D. McNeill; D. Meade; S. Medley; W. Morris; D. Mueller; E. Nieschmidt; D. Owens; J. Schivell; G. Schilling; G. Schmidt; S. Scott; S. Sesnic; J. Sinnis; F. Stauffer; B. Stratton; G. Tait; G. Taylor; H. Towner; M. Ulrickson; S. von Goeler; R. Wieland; M. Williams; K. L. Wong; S. Yoshikawa; K. Young; S. Zweben

1987-01-01

45

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

46

High-Frequency Gravitational Wave Induced Nuclear Fusion  

SciTech Connect

Nuclear fusion is a process in which nuclei, having a total initial mass, combine to produce a single nucleus, having a final mass less than the total initial mass. Below a given atomic number the process is exothermic; that is, since the final mass is less than the combined initial mass and the mass deficit is converted into energy by the nuclear fusion. On Earth nuclear fusion does not happen spontaneously because electrostatic barriers prevent the phenomenon. To induce controlled, industrial scale, nuclear fusion, only a few methods have been discovered that look promising, but net positive energy production is not yet possible because of low overall efficiency of the systems. In this paper we propose that an intense burst of High Frequency Gravitational Waves (HFGWs) could be focused or beamed to a target mass composed of appropriate fuel or target material to efficiently rearrange the atomic or nuclear structure of the target material with consequent nuclear fusion. Provided that efficient generation of HFGW can be technically achieved, the proposed fusion reactor could become a viable solution for the energy needs of mankind and alternatively a process for beaming energy to produce a source of fusion energy remotely - even inside solid materials.

Fontana, Giorgio [University of Trento, 38050 POVO (Italy); Baker, Robert M. L. Jr. [Transportation Sciences Corporation and GRAVWAVE LLC, 8123 Tuscany Avenue, Playa del Rey, California 90293 (United States)

2007-01-30

47

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

48

Edge density profiles of high beta plasma in CHS  

SciTech Connect

The temporal behavior of electron density profiles of edge plasmas in the Compact Helical System (CHS) during high beta discharges was measured with a thermal neutral lithium beam probe. A large outward shift of the plasma edge boundary was observed with an increase in the beta value. The position of the plasma edge boundary measured experimentally was compared with that of the last closed flux surface (LCFS) calculated by the VMEC code, and qualitative agreement was found between experimental and theoretical results. The experiment on the dynamic poloidal field control during the discharge was also performed successfully to fix the position of the edge plasma boundary when the plasma beta was raised. 10 refs., 6 figs.

Morisaki, Tomohiro; Komori, Akio; Okamura, Shoichi [National Inst. for Fusion Science, Nagoya (Japan)] [and others

1995-04-01

49

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

SciTech Connect

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

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

2010-04-09

50

High-Level Fusion of Depth and Intensity for Pedestrian Classification  

E-print Network

detection rates). Moreover, high-level fusion outperforms low-level fusion using a joint feature spaceHigh-Level Fusion of Depth and Intensity for Pedestrian Classification Marcus Rohrbach1,3, , Markus. This paper presents a novel approach to pedestrian classi- fication which involves a high-level fusion

51

High-Level Fusion of Depth and Intensity for Pedestrian Classification  

E-print Network

detection rates). Moreover, high-level fusion outperforms low-level fusion using a joint feature spaceHigh-Level Fusion of Depth and Intensity for Pedestrian Classification Marcus Rohrbach1,3 , Markus. This paper presents a novel approach to pedestrian classi- fication which involves a high-level fusion

Gavrila, Dariu M.

52

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

NASA Astrophysics Data System (ADS)

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

Punjabi, Alkesh

2005-10-01

53

Beam combined laser fusion driver with high power and high repetition rate using stimulated Brillouin scattering  

E-print Network

Beam combined laser fusion driver with high power and high repetition rate using stimulated laser fusion energy generation, it is necessary to have a M-J laser system with a repetition rate over of the high power laser. In this paper, we present the recent results about the beam combination laser

Kim, Yong Jung

54

CC CKR5: A RANTES, MIP1alpha, MIP1beta Receptor as a Fusion Cofactor for Macrophage-Tropic HIV1  

Microsoft Academic Search

Human immunodeficiency virus-type 1 (HIV-1) entry requires fusion cofactors on the CD4^+ target cell. Fusin, a heterotrimeric GTP-binding protein (G protein)-coupled receptor, serves as a cofactor for T cell line-tropic isolates. The chemokines RANTES, MIP-1alpha, and MIP-1beta, which suppress infection by macrophage-tropic isolates, selectively inhibited cell fusion mediated by the corresponding envelope glycoproteins (Envs). Recombinant CC CKR5, a G protein-coupled

Ghalib Alkhatib; Christophe Combadiere; Christopher C. Broder; Yu Feng; Paul E. Kennedy; Philip M. Murphy; Edward A. Berger

1996-01-01

55

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

PubMed

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

McKay, Kyle; Wolter, Scott; Kim, Jungsang

2012-05-01

56

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

NASA Astrophysics Data System (ADS)

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

McKay, Kyle; Wolter, Scott; Kim, Jungsang

2012-05-01

57

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

58

High-cycle fatigue resistance in beta-titanium alloys  

Microsoft Academic Search

A survey of high-cycle fatigue data for commercial beta-titanium alloys was conducted to rationalize the wide variations in fatigue resistance even at similar tensile-strength levels. It was found that fatigue behavior, especially the endurance limits, for various alloy compositions can be roughly grouped into three classes on the basis of processing, heat treatment, and resulting microstructure. The implications of such

S. K. Jha; K. S. Ravichandran

2000-01-01

59

Development of high power ion sources for fusion (invited)  

NASA Astrophysics Data System (ADS)

Recent progress and development activities regarding high power ion sources for fusion researches are reviewed. High power positive ion sources, which have progressed in the 1980s, played important roles in fusion research. Most of the ion sources developed for major neutral beam injection (NBI) systems are a large area magnetic multipole type with tungsten cathode, and produce tens of amperes of positive hydrogen/deuterium/tritium ion beams at the energy around 100 keV. The NBI systems based on these ion sources delivered tens of MW neutral beams to the plasmas, and contributed to produce high temperature plasmas in the break-even condition in the tokamak type fusion devices. Meanwhile, R and D of high current negative ion sources were carried out for a high energy NBI system to be utilized not only for plasma heating, but also for the steady state operation and stable plasma control in the fusion burning plasmas. In the 1990s, rapid progress of high current negative ion sources has been made. Particularly, a cesiated magnetic filter source with high plasma confinement has, for the first time, produced a multi-ampere negative ion beam stably in the conditions required for the negative-ion-based NBI systems, namely high negative ion current density, low operating pressure, low extracted electron current, and good beamlet optics. Based on this progress, a 500 keV 10 MW NBI system has been developed for JT-60U at the Japan Atomic Energy Research Institute, and construction of a 180 keV 15 MW NBI system is carried on at the National Institute for Fusion Science in Japan. The same type of negative ion source is applied to the design of a 1 MeV NBI system for the International Thermonuclear Experimental Reactor (ITER).

Ohara, Y.

1998-02-01

60

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

61

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. M.; Kotschenreuther, M.; Mahajan, S. M. [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712-1060 (United States); Canik, J. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States)

2009-05-15

62

High rate 4. pi. beta. -. gamma. coincidence counting system  

SciTech Connect

A high count rate 4..pi.. ..beta..-..gamma.. coincidence counting system for the determination of absolute disintegration rates of short half-life radionuclides is described. With this system the dead time per pulse is minimized by not stretching any pulses beyond the width necessary to satisfy overlap coincidence requirements. The equations used to correct for the ..beta.., ..gamma.., and coincidence channel dead times and for accidental coincidences are presented but not rigorously developed. Experimental results are presented for a decaying source of /sup 56/Mn initially at 2 x 10/sup 6/ d/s and a set of /sup 60/Co sources of accurately known source strengths varying from 10/sup 3/ to 2 x 10/sup 6/ d/s. A check of the accidental coincidence equation for the case of two independent sources with varying source strengths is presented.

Johnson, L.O.; Gehrke, R.J.

1978-01-01

63

1. INTRODUCTION High-energy fusion-product (fp) transport (e.g., alpha particle  

E-print Network

-T plasmas) is a central issue in fusion reactor de- velopment. Important effects dependent on fp transport by energetic, charged fusion products is a crucial issue for obtaining fusion reactor conditions. The evolution1 1. INTRODUCTION High-energy fusion-product (fp) transport (e.g., alpha particle transport in D

Hively, Lee M.

64

X-1: The challenge of high fusion yield  

SciTech Connect

In the past three years, tremendous strides have been made in x-ray production using high-current z-pinches. Today, the x-ray energy and power output of the Z accelerator (formerly PBFA II) is the largest available in the laboratory. These z-pinch x-ray sources have great potential to drive high-yield inertial confinement fusion (ICF) reactions at affordable cost if several challenging technical problems can be overcome. Technical challenges in three key areas are discussed in this paper: (1) the design of a target for high yield, (2) the development of a suitable pulsed power driver, and (3) the design of a target chamber capable of containing the high fusion yield.

Cook, D.L.; Ramirez, J.J.; Raglin, P.S. [and others

1998-06-01

65

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

66

Experimental and theoretical studies of belt pinches and high-beta Tokamaks  

Microsoft Academic Search

Experimental and theoretical studies of belt pinches and rectangular high-beta Tokamaks are summarized which have been performed to determine the equilibrium and stability characteristics of noncircular high-beta toroidal plasmas as functions of beta, safety factor, and geometry. The Columbia Torus I device, which is operated as a pure belt pinch, is described along with the Maryland Terp experiment, which is

C. K. Chu; R. A. Gross; H. C. Lui; M. Reusch; F. Sandel; K. L. Wong; A. W. Allen; G. C. Goldenbaum; J. A. Tataronis; W. Grossmann

1977-01-01

67

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

68

Deuterium--tritium high confinement (H-mode) studies in the Tokamak Fusion Test Reactor  

SciTech Connect

High or enhanced confinement (H-mode) plasmas have been obtained for the first time with nearly equal concentrations of deuterium and tritium in high-temperature, high poloidal beta plasmas in the Tokamak Fusion Test Reactor (TFTR) [McGuire, Phys. Plasmas {bold 2}, 2176 (1995)]. Tritium fueling was provided mainly through high-power neutral beam injection (NBI) with powers up to 31 MW and beam energies of 90--110 keV. A transition to a circular limiter H-mode configuration has been obtained, following a programmed rapid decrease of the plasma current. Isotope effects, due to the presence of tritium, led to different behavior for deuterium--deuterium (DD) and deuterium--tritium (DT) H-modes relative to confinement, edge localized magnetohydrodynamic modes (ELMs), and ELM effects on fusion products. However, the threshold power for the H-mode transition was the same in DD and DT. Some of the highest values of the global energy confinement time, {tau}{sub {ital E}}, have been achieved on TFTR during the ELM-free phase of DT H-mode plasmas. Enhancements of {tau}{sub {ital E}} greater than four times the L-mode have been attained.

Bush, C.E.; Sabbagh, S.A.; Zweben, S.J.; Bell, R.E.; Synakowski, E.J.; Taylor, G.; Batha, S.; Bell, M.; Bitter, M.; Bretz, N.L.; Budny, R.; Chang, Z.; Darrow, D.S.; Efthimion, P.C.; Ernst, D.; Fredrickson, E.; Hanson, G.R.; Johnson, L.C.; Kesner, J.; LeBlanc, B.; Levinton, F.M.; Mansfield, D.; Mauel, M.E.; Mazzucato, E.; McCune, D.; Murakami, M.; Nazikian, R.; Navratil, G.A.; Park, H.; Paul, S.F.; Phillips, C.K.; Redi, M.H.; Schivell, J.; Scott, S.D.; Skinner, C.H.; Towner, H.H.; Wilgen, J.B.; Zarnstorff, M.C. [Princeton University, Plasma Physics Laboratory, P.O. 451, Princeton, New Jersey 08543 (United States)] [Princeton University, Plasma Physics Laboratory, P.O. 451, Princeton, New Jersey 08543 (United States); the TFTR Group

1995-06-01

69

Fusion blankets for high-efficiency power cycles  

SciTech Connect

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

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

1980-01-01

70

Fusion blanket for high-efficiency power cycles  

SciTech Connect

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

1980-01-01

71

High temperature plasma in beta Lyrae, observed from Copernicus  

NASA Technical Reports Server (NTRS)

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

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

1975-01-01

72

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.

73

Applications of high-speed dust injection to magnetic fusion  

SciTech Connect

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

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

2012-08-08

74

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

75

Design considerations for achieving high vacuum integrity in fusion devices  

SciTech Connect

Achieving high vacuum integrity in fusion devices requires close attention to both the overall system configuration and the design details of joints and seals. This paper describes the factors in selecting the system configuration, from a vacuum standpoint, for the Princeton Plasma Physics Laboratory (PPPL) DCT-8 Tokamak device. The DCT-8 (driven current tokamak) is the eighth design in a series of tokamak concepts defined to cover the magnetic confinement and development gap between the Tokamak Fusion Test Reactor (TFTR) and the Engineering Test Reactor (ETR). Leak detection concept development is considered a vital activity, as well as the definition of a configuration that minimizes the consequences of leaks. A major part of the vacuum boundaries of the magnet system and the plasma system is common. For the major penetrations, primary and secondary seals are provided with vacuum control over the region between seals. The intent is to instrument these cavities and provide automated recordings of these measurements for leak maintenance.

Fuller, G.M.; Haines, J.R.

1983-01-01

76

Fusion reactor high vacuum pumping: Charcoal cryosorber tritium exposure results  

SciTech Connect

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

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

1991-01-01

77

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

PubMed Central

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

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

2014-01-01

78

High frequency of fusion transcripts involving TCF7L2 in colorectal cancer: novel fusion partner and splice variants.  

PubMed

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

Nome, Torfinn; Hoff, Andreas M; Bakken, Anne Cathrine; Rognum, Torleiv O; Nesbakken, Arild; Skotheim, Rolf I

2014-01-01

79

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

E-print Network

High level information fusion for tracking and projection of multistage cyber attacks Shanchieh J, industry, and personal businesses. Protection and defense against cyber attacks on computer networks-depth discussion is provided to define fusion tasks for cyber defense. A novel cyber fusion system is proposed

Kuhl, Michael E.

80

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

81

Electromagnetic effects on dynamics of high-beta filamentary structures  

NASA Astrophysics Data System (ADS)

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

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

2015-01-01

82

High-temperature fusion blanket for a synthetic fuel plant  

NASA Astrophysics Data System (ADS)

A fusion reactor to drive a synthetic fuel production plant is described. The particular synfuel process involves dissociation of CO2 at high-temperature and subsequent rapid cooling in an unsteady wave reactor to 'freeze' the CO constituent which later produces H2 (the synthetic fuel) and CO2 when reacted with steam. This technique requires very high temperatures, 2400 K or more, in the blanket outlet stream to achieve efficient synfuel conversion and therefore demands an unusual blanket, designed to withstand both high temperature and a chemically reactive environment. A promising design for such a blanket is described which is characterized by low-pressure coolant, a ceramic 'brick oven' matrix and structural support by a thin, relatively cool, metal jacket.

Steinhauer, L. C.; Shirazian, M. H.; Bruzzone, C.

83

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

84

High-Level Information Fusion and Mission Planning in Highly Anisotropic Threat Spaces  

E-print Network

High-Level Information Fusion and Mission Planning in Highly Anisotropic Threat Spaces Mark spaces, and associated route planning for a variety of effects based tasks taking into account commander preferences in effects routing, facilitates cooperative command planning, and analysis of opponent

Witkowski, Mark

85

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

86

High-beta operation and magnetohydrodynamic activity on the TFTR tokamak  

SciTech Connect

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

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

1990-06-01

87

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

88

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

89

Development and application of nonflammable, high-temperature beta fibers  

NASA Technical Reports Server (NTRS)

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

Dawn, Frederic S.

1989-01-01

90

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

91

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

PubMed Central

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

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

2014-01-01

92

Characterization of a beta-glycosidase highly active on disaccharides and of a beta-galactosidase from Tenebrio molitor midgut lumen.  

PubMed

The midgut of the yellow mealworm, Tenebrio molitor L. (Coleoptera: Tenebrionidae) larvae has four beta-glycosidases. The properties of two of these enzymes (betaGly1 and betaGly2) have been described elsewhere. In this paper, the characterization of the other two glycosidases (betaGly3 and betaGly4) is described. BetaGly3 has one active site, hydrolyzes disaccharides, cellodextrins, synthetic substrates and beta-glucosides produced by plants. The enzyme is inhibited by amygdalin, cellotriose, cellotetraose and cellopentaose in high concentrations, probably due to transglycosylation. betaGly3 hydrolyzes beta 1,4-glycosidic linkages with a catalytic rate independent of the substrate polymerization degree (k(int)) of 11.9 s(-1). Its active site is formed by four subsites, where subsites +1 and -1 bind glucose residues with higher affinity than subsite +2. The main role of betaGly3 seems to be disaccharide hydrolysis. BetaGly4 is a beta-galactosidase, since it has highest activity against beta-galactosides. It can also hydrolyze fucosides, but not glucosides, and has Triton X-100 as a non-essential activator (K(a)=15 microM, pH 4.5). betaGly4 has two active sites that can hydrolyze p-nitrophenyl beta-galactoside (NPbetaGal). The one hydrolyzing NPbetaGal with more efficiency is also active against methylumbellipheryl beta-D-galactoside and lactose. The other active site hydrolyzes NPbetaFucoside and binds NPbetaGal weakly. BetaGly4 hydrolyzes hydrophobic substrates with high catalytical efficiency and is able to bind octyl-beta-thiogalactoside in its active site with high affinity. The betaGly4 physiological role is supposed to be the hydrolysis of galactolipids that are found in membranes from vegetal tissues. As the enzyme has a hydrophobic site where Triton X-100 can bind, it might be activated by membrane lipids, thus becoming fully active only at the surface of cell membranes. PMID:12535683

Ferreira, Alexandre H P; Terra, Walter R; Ferreira, Clélia

2003-02-01

93

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

94

Application of modulation transfer function in high-resolution image fusion  

NASA Astrophysics Data System (ADS)

Modulation transfer function (MTF) is applied to the high frequency modulation fusion in this paper. Firstly, MTFs are calculated using the edge method, and 2-dimension MTF-filters are properly designed. Secondly, MTF-filters are used for degrading original high resolusion images. High frequency modulation fusion parameters are then obtained under the minimum mean square error criterion. The results show that fusion images derived from the improved high frequency modulation based on MTF method have spatial resolution close to non-degraded pan images. Compared with fusion methods of weighted high-pass filtering (w-HPF), MTF general image fusion framework (MTF-GIF), the improved method performs well in terms of preservation of spectral information and spatial resolution.

Zhang, Xiaoping; Jia, Yonghong; Chen, Xiaoyan; Pan, Delu; Chen, Jianyu; Hao, Zengzhou

2011-11-01

95

Physics and optimization of beta beams: From low to very high gamma  

NASA Astrophysics Data System (ADS)

The physics potential of beta beams is investigated from low to very high gamma values and it is compared to superbeams and neutrino factories. The gamma factor and the baseline are treated as continuous variables in the optimization of the beta beam, while a fixed mass water Cherenkov detector or a totally active scintillator detector is assumed. We include in our discussion also the gamma dependence of the number of ion decays per year. For low gamma, we find that a beta beam could be a very interesting alternative to a superbeam upgrade, especially if it is operated at the second oscillation maximum to reduce correlations and degeneracies. For high gamma, we find that a beta beam could have a potential similar to a neutrino factory. In all cases, the sensitivity of the beta beams to CP violation is very impressive if similar neutrino and antineutrino event rates can be achieved.

Huber, Patrick; Lindner, Manfred; Rolinec, Mark; Winter, Walter

2006-03-01

96

Beta3 integrin deficiency promotes atherosclerosis and pulmonary inflammation in high-fat-fed, hyperlipidemic mice.  

PubMed

Hyperlipidemia promotes the chronic inflammatory disease atherosclerosis through poorly understood mechanisms. Atherogenic lipoproteins activate platelets, but it is unknown whether platelets contribute to early inflammatory atherosclerotic lesions. To address the role of platelet aggregation in diet-induced vascular disease, we studied beta3 integrin-deficient mice (lacking platelet integrin alphaIIbbeta3 and the widely expressed nonplatelet integrin alphavbeta3) in two models of atherosclerosis, apolipoprotein E (apoE)-null and low-density lipoprotein receptor (LDLR)-null mice. Unexpectedly, a high-fat, Western-type (but not a low-fat) diet caused death in two-thirds of the beta3-/-apoE-/- and half of the beta3-/-LDLR-/- mice due to noninfectious pneumonitis. In animals from both models surviving high-fat feeding, pneumonitis was absent, but aortic atherosclerosis was 2- to 6-fold greater in beta3-/- compared with beta+/+ littermates. Expression of CD36, CD40L, and CD40 was increased in lungs of beta3-/-LDLR-/- mice. Each was also increased in smooth muscle cells cultured from beta3-deficient mice and suppressed by retroviral reconstitution of beta3. These data show that the platelet defect caused by alphaIIbbeta3 deficiency does not impair atherosclerotic lesion initiation. They also suggest that alphavbeta3 has a suppressive effect on inflammation, the loss of which induces atherogenic mediators that are amplified by diet-induced hyperlipidemia. PMID:12746502

Weng, Sherry; Zemany, Laura; Standley, Kara N; Novack, Deborah V; La Regina, Marie; Bernal-Mizrachi, Carlos; Coleman, Trey; Semenkovich, Clay F

2003-05-27

97

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

98

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

99

Observation of a stable high-beta axisymmetric plasma equilibrium  

Microsoft Academic Search

Stable, steady-state plasma equilibrium is generated in an axisymmetric configuration. The diamagnetic current is maintained by electromagnetic fields rotating in the electron diamagnetic sense. The stable, free-standing equilibrium exists for all values of beta up to 0.98, limited only by the available rf power. The plasma is centered on the axis well removed from the metal chamber walls, the limiters,

A. Kuthi; H. Zwi; L. Schmitz; A. Y. Wong

1989-01-01

100

Alfvén acoustic channel for ion energy in high-Beta tokamak plasmas.  

PubMed

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

Bierwage, Andreas; Aiba, Nobuyuki; Shinohara, Kouji

2015-01-01

101

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

NASA Astrophysics Data System (ADS)

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

Bierwage, Andreas; Aiba, Nobuyuki; Shinohara, Kouji

2015-01-01

102

Highly enantioselective synthesis of alpha,beta-diaminopropanoic acid derivatives using a catalytic asymmetric hydrogenation approach.  

PubMed

Rh-DuPhos-catalyzed asymmetric hydrogenation of alpha,beta-diamidoacrylates provides a highly efficient and enantioselective route to chiral alpha,beta-diaminopropanoic acid derivatives. The mechanistic course of the hydrogenation was studied using isotopically enriched enamide complexes and phosphorus and carbon NMR. Addition of methyl alpha-N-benzoyl-beta-N-acetyl-diaminopropenoate to the solvated catalyst gave a single 1:1 enamide complex and demonstrated the binding of the olefin and alpha-amide carbonyl group; the carboxylate and beta-N-acyl groups did not bind to the metal. Changes to the electronic and steric properties of the beta-N-acyl group were well tolerated; however, small changes to the binding alpha-N-acyl group were found to significantly affect hydrogenation yields. PMID:11397145

Robinson, A J; Lim, C Y; He, L; Ma, P; Li, H Y

2001-06-15

103

The high current transport experiment for heavy ion inertial fusion  

SciTech Connect

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

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

2004-05-01

104

Interaction of high-energy trapped particles with ballooning modes in a tokamak with a high-. beta. plasma  

SciTech Connect

A theory is derived for the interaction of high-energy trapped particleswith ballooning modes in a tokamak with a high-..beta.. plasma. A dispersionrelation is derived to describe the ballooning modes in the presence ofsuch particles; the effects of the high plasma ..beta.. are taken into account.The stability boundary for ballooning modes with zero and finite frequenciesis studied. The effects of finite bananas on the stability of ballooningmodes with zero frequencies are determined.

Mikhailovskii, A. B.; Novakovaskii, S. V.; Smolyakov, A. I.

1988-12-01

105

An Overview of High-Gain Targets for Inertial Fusion Energy  

E-print Network

An Overview of High-Gain Targets for Inertial Fusion Energy L. John Perkins Lawrence Livermore Fusion Energy L. John Perkins Lawrence Livermore National Laboratory This work was performed under/U.Bordeaux)! · A.Casner (CEA, France)! · !M.Roth (Technical University of Darmstadt/GSI, Germany)! · !S

106

Electromagnetic transducers close to high temperature plasma in the thermonuclear fusion experiment RFX  

Microsoft Academic Search

RFX is a magnetically confined fusion experiment in operation since 1992 in Padova (Italy). Analysis of magnetic field is essential for the safe operation of the machine and the understanding of high temperature plasma dynamics. Both of these issues require an accurate electromagnetic diagnostic system. In this paper after a discussion on the problems related to magnetic measurements in fusion

P. Fiorentin; S. Peruzzo; N. Pomaro; P. Sonato

1999-01-01

107

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

108

High-pressure liquid chromatographic determination of chlorphenesin carbamate and the beta-isomeric carbamate.  

PubMed

A high-pressure liquid chromatographic assay was developed for the determination of chlorphenesin carbamate and its beta-isomeric carbamate. A single 4-mm i.d. X 30-cm column, prepacked with 10 micrometer fully porous silica gel particles, is used with 3% methanol in 50% water-saturated butyl chloride as the mobile phase. The procedure separates chlorphenesin carbamate from several possible impurities in addition to the beta-isomeric carbamate. The assay was applied to bulk drug and compressed tablets. The relative standard deviations for the assays of chlorphenesin carbamate and the beta-isomer are approximately 1 and 2%, respectively. PMID:1032666

Beyer, W F

1976-12-01

109

Inverted high-temperature quartz. Unit cell parameters and properties of the alpha-beta inversion  

Microsoft Academic Search

Fifty-two samples of inverted high-temperature quartz from volcanic rocks were investigated by Guinier-Jago powder diffractometry and differential scanning calorimetry (DSC). Quartz megacrysts from Clear Lake and Cinder Cone, California show a variability of ~=2.5 ° K in their alpha-beta transition temperature ( T alpha-beta). Quartz phenocrysts and quartz from crystalline rocks give a range of 0.5 ° K in T

M. S. Ghiorso; I. S. E. Carmichael; L. K. Moret

1979-01-01

110

Improved confinement at high density and high beta in the MST  

NASA Astrophysics Data System (ADS)

Improved confinement plasmas in MST are routine using current profile control to reduce tearing instabilities. With pellet injection, the density of these plasmas has been increased to values well above the Greenwald limit. At 0.2 MA, the achieved density exceeds the limit by 50%. At 0.5 MA, an MST-record density of 0.7 x 10^20 m-3 is achieved that exceeds the limit by 10%. While confinement is improved at high density, tearing instabilities are not reduced to the same degree as at lower density. This may be due to the larger beta at high density, with total beta reaching 26%. The central pressure gradient violates the Mercier criterion, and linear stability calculations indicate that pressure-driven tearing could be important. The maximum MST energy confinement time of 12 ms, achieved at well below the density limit, is within a factor of two of expectations for a tokamak of the same size, current, and heating power. Supported by USDOE.

Chapman, B. E.; Almagri, A. F.; Anderson, J. K.; Caspary, K. J.; Clayton, D. J.; den Hartog, D. J.; Ebrahimi, F.; Fiksel, G.; Goetz, J. A.; Kumar, S.; Magee, R. M.; Reusch, J. A.; Sarff, J. S.; Stephens, H. D.; Yang, Y. M.; Bergerson, W. F.; Brower, D. L.; Ding, W. X.; Lin, L.; Combs, S.; Foust, C.

2010-11-01

111

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

112

High levels of Lymphotoxin-Beta (LT-Beta) gene expression in rheumatoid arthritis synovium: clinical and cytokine correlations  

Microsoft Academic Search

Lymphotoxin-Beta (LT-Beta) is implicated in lymphoid follicle development, production of pro-inflammatory cytokines, and can\\u000a enhance the proliferation of fibroblasts and synoviocytes. The objective of this study was to investigate LT-Beta and LT-BetaReceptor\\u000a (LT-BetaR) gene expression in RA patient synovium and blood samples compared with control individuals, and correlate with\\u000a LT-Alpha and TNF-Alpha gene expression and disease parameters. RT-PCR was used

Killian P. O’Rourke; G. O’Donoghue; C. Adams; H. Mulcahy; C. Molloy; C. Silke; M. Molloy; F. Shanahan; F. O’Gara

2008-01-01

113

Inertial Confinement Fusion Ignition and High Yield Campaign  

E-print Network

- refurbishment needed · $57M total estimated cost, 4-5 year schedule #12;8 OMEGA Extended Performance (EP-ignition experiments · $45-55M total estimated cost, 4-5 year schedule #12;9 The first four NIF beamlines have been · Predicted gains (fusion energy produced/laser energy input) have increased · Direct drive ignition shows

114

Highly efficient synthesis of beta-amino acid derivatives via asymmetric hydrogenation of unprotected enamines.  

PubMed

A direct asymmetric hydrogenation of unprotected enamino esters and amides is described. Catalyzed by Rh complexes with Josiphos-type chiral ligands, this method gives beta-amino esters and amides in high yield and high ee (93-97% ee). No acyl protection/deprotection is required. PMID:15303855

Hsiao, Yi; Rivera, Nelo R; Rosner, Thorsten; Krska, Shane W; Njolito, Eugenia; Wang, Fang; Sun, Yongkui; Armstrong, Joseph D; Grabowski, Edward J J; Tillyer, Richard D; Spindler, Felix; Malan, Christophe

2004-08-18

115

An Improved High Frequency Modulating Fusion Method Based on Modulation Transfer Function Filters  

NASA Astrophysics Data System (ADS)

GeoEye-1 is the most advanced and highest resolution commercial earth imaging satellite in the world today. It provides multispectral images (MS) and Panchromatic image (PAN) with spatial resolutions of 2.0 m and 0.5 m respectively. Image fusion is very important for mapping and image interpretation because it can take advantage of the complementary spatial/spectral resolution characteristics of remote sensing imagery. So an improved high frequency modulation fusion method based on MTF is proposed. Modulation transfer functions (MTF) are firstly measured from GeoEye-1 images, and then the degraded images based on MTF filters are obtained. Secondly, modulating parameter is obtained based on Minimum Mean Square Error, and image fusion is performed and measured in the degraded version. Finally, fused images with the high spatial resolution are produced by using the proposed method. Compared with fusion methods of weighted high passing filtering(w-HPF) in ERDAS IMAGINE and general image fusion based on MTF( MTF-GIF), The results of fused GeoEye-1 images show that the proposed method is an efficient way for GeoEye-1 image fusion, which can keep spectral information with the high spatial resolution.

Jia, Y.; Wu, M.; Zhang, X.

2012-07-01

116

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

E-print Network

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

117

Satellite image fusion based on principal component analysis and high-pass filtering.  

PubMed

This paper presents an integrated method for the fusion of satellite images. Several commercial earth observation satellites carry dual-resolution sensors, which provide high spatial resolution or simply high-resolution (HR) panchromatic (pan) images and low-resolution (LR) multi-spectral (MS) images. Image fusion methods are therefore required to integrate a high-spectral-resolution MS image with a high-spatial-resolution pan image to produce a pan-sharpened image with high spectral and spatial resolutions. Some image fusion methods such as the intensity, hue, and saturation (IHS) method, the principal component analysis (PCA) method, and the Brovey transform (BT) method provide HR MS images, but with low spectral quality. Another family of image fusion methods, such as the high-pass-filtering (HPF) method, operates on the basis of the injection of high frequency components from the HR pan image into the MS image. This family of methods provides less spectral distortion. In this paper, we propose the integration of the PCA method and the HPF method to provide a pan-sharpened MS image with superior spatial resolution and less spectral distortion. The experimental results show that the proposed fusion method retains the spectral characteristics of the MS image and, at the same time, improves the spatial resolution of the pan-sharpened image. PMID:20508708

Metwalli, Mohamed R; Nasr, Ayman H; Allah, Osama S Farag; El-Rabaie, S; Abd El-Samie, Fathi E

2010-06-01

118

High Beta Observations of the Hot Electron Interchange Instability  

E-print Network

October 30 - November 3, 2006 #12;Abstract High frequency (f > 1 MHz) electrostatic fluctuations have been with coherent structures that have been detected on fast high-impedance electrostatic probes and edge Mirnov formation and pressure limits. (1) E.Ortiz to appear in J. Fus. Energy (2006). #12;Outline · Motivation

119

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

120

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

121

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

NASA Astrophysics Data System (ADS)

Potential problems and uncertainties are associated with the complex nature of fracture in solution treated and aged (STA) beta-titanium (beta-Ti) alloys, as well as the potential for long-term alloy degradation due to hydrogen embrittlement. This research characterizes the effects of predissolved hydrogen and microstructural conditions on the fracture resistance of two solution treated and aged (STA) high strength beta-titanium alloys, Low Cost Beta (LCB) and Ti-15-3, in sheet form. Rising-CMOD fracture test results demonstrate that STA beta-Ti alloys are severely embrittled at room temperature and a slow displacement rate above a relatively low threshold hydrogen concentration. Hydrogen concentrations of 400 and 500 wppm reduce the threshold stress intensity at the onset of hydrogen cracking to 50% of the air fracture toughness in STA LCB, and Ti-15-3, respectively. Significant embrittlement for both alloys is triggered at concentrations in excess of 750 wppm, with reductions in threshold stress intensity to an asymptotic value equal to 25% of the air fracture toughness. Reductions in crack growth resistance with increasing hydrogen concentrations are accompanied by significant increases in subcritical crack growth rates. Changes in fracture mode are concurrent with reduced in fracture resistance. With increasing hydrogen concentration, the fracture mode changes from microvoid coalescence to transgranular hydrogen-assisted alpha/beta interface cracking. Two mechanisms of internal hydrogen embrittlement in STA metastable beta-Ti alloys, bond decohesion and hydride formation are proposed to occur at alpha/beta interfaces. A critical isothermal aging time must be exceeded to render Ti-15-3 susceptible to internal hydrogen embrittlement. This is attributed to a critical alpha volume fraction and the associated stress and hydrogen concentration. The internal hydrogen embrittlement of STA Ti-15-3 is a time dependent phenomenon. Experimental results and crack tip strain rate calculations demonstrate that embrittlement will persist in STA Ti-15-3 to loading rates of approximately 0.5 MPa?m/s. As such, hydrogen redistribution to the crack tip is a critical component of internal hydrogen embrittlement. Local transport of hydrogen in intra-alpha beta to susceptible alpha/beta interfaces, and possibly growth kinetics of gamma-TiH2, in the fracture process zone are consistent with the observed kinetics and appear to govern the time dependence.

Hayes, Sean Paul

122

High-Precision Measurements of the Superallowed Beta+ Decays of 38Ca and 46V  

E-print Network

depended on beta-delayed gamma-ray intensities being measured with a high-purity germanium detector calibrated for absolute efficiency to 0.2% precision. This branching-ratio result represents our first step in bringing the ft value for the superallowed ³?...

Park, Hyo-In

2012-10-19

123

Ballooning-mode stability of bean-shaped cross sections for high-. beta. tokamak plasmas  

SciTech Connect

Indentation of a tokamak plasma on its inner major radius side is shown to be strongly beneficial for achieving high-..beta.. stability against ballooning modes. Using a set of reasonable equilibrium profiles, it is found that moderate indentation provides accessibility to the second region of stability. Ohmic equilibrium configurations which exhibit the second stability region have not yet been found.

Chance, M.S.; Jardin, S.C.; Stix, T.H.

1983-09-01

124

Experimental and theoretical studies of belt pinches and high-beta Tokamaks  

Microsoft Academic Search

Several experimental and theoretical studies of belt pinches and high-beta Tokamaks are summarized. Numerical calculations supporting these experiments include equilibrium, stability, heating, and initial implosion dynamics. A general stability analysis of diffuse belt pinch configurations is reported. Results indicate that favorable stability properties can be obtained by shaping the current density profile and plasma geometry.

C. K. Chu; R. A. Gross; H. C. Lui; M. F. Reusch; F. Sandel; K. L. Wong; A. W. Allen; G. C. Goldenbaum; J. A. Tataronis; W. Grossmann

1976-01-01

125

Origins of the high 14-helix propensity of cyclohexyl-rigidified residues in beta-peptides.  

PubMed

[structure: see text] beta-Peptides containing residues derived from trans-2-aminocyclohexanecarboxylic acid (ACHC) display high population of 14-helical secondary structure in aqueous solution. We show that hydrophobic interactions between cyclohexyl rings are not responsible for this conformation-promoting effect, and that polar groups may be attached to the cyclohexyl ring without diminishing the effect. PMID:17394351

Lee, Myung-Ryul; Raguse, Tami L; Schinnerl, Marina; Pomerantz, William C; Wang, Xiaodong; Wipf, Peter; Gellman, Samuel H

2007-04-26

126

High-Density and High-pR Fuel Assembly for Fast-Ignition Inertial Confinement Fusion  

SciTech Connect

Scaling relations to optimize implosion parameters for fast-ignition inertial confinement fusion are derived and used to design high-gain fast-ignition targets. A method to assemble thermonuclear fuel at high densities, high pR, and with a small-size hot spot is presented.

Bett, R.; Zhou, C.

2005-11-09

127

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

128

Acceleration of neon pellets to high speeds for fusion applications  

NASA Astrophysics Data System (ADS)

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

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

1996-03-01

129

High-cycle fatigue resistance in beta-titanium alloys  

Microsoft Academic Search

A survey of high-cycle fatigue data for commercial ?-titanium alloys was conducted to rationalize the wide variations in fatigue\\u000a resistance even at similar tensile-strength levels. It was found that fatigue behavior, especially the endurance limits, for\\u000a various alloy compositions can be roughly grouped into three classes on the basis of processing, heat treatment, and resulting\\u000a microstructure. The implications of such

S. K. Jha; K. S. Ravichandran

2000-01-01

130

High-cycle fatigue resistance in beta-titanium alloys  

NASA Astrophysics Data System (ADS)

A survey of high-cycle fatigue data for commercial ?-titanium alloys was conducted to rationalize the wide variations in fatigue resistance even at similar tensile-strength levels. It was found that fatigue behavior, especially the endurance limits, for various alloy compositions can be roughly grouped into three classes on the basis of processing, heat treatment, and resulting microstructure. The implications of such classification on microstructure control for increased fatigue resistance is discussed.

Jha, S. K.; Ravichandran, K. S.

2000-03-01

131

Catalyzed deuterium-deuterium and deuterium-tritium fusion blankets for high temperature process heat production  

Microsoft Academic Search

Tritiumless blanket designs, associated with a catalyzed deuterium-deuterium (D-D) fusion cycle and using a single high temperature solid pebble or falling bed zone, for process heat production, are proposed. Neutronics and photonics calculations, using the Monte Carlo method, show that an about 90% heat deposition fraction is possible in the high temperature zone, compared to a 30 to 40% fraction

M. M. H. Ragheb; B. Salimi

1982-01-01

132

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

133

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

PubMed Central

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

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

2014-01-01

134

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

SciTech Connect

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

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

2012-04-30

135

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

PubMed Central

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

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

2013-01-01

136

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

137

The National Ignition Facility - Applications for Inertial Fusion Energy and High Energy Density Science  

SciTech Connect

Over the past several decades, significant and steady progress has been made in the development of fusion energy and its associated technology and in the understanding of the physics of high-temperature plasmas. While the demonstration of net fusion energy (fusion energy production exceeding that required to heat and confine the plasma) remains a task for the next millennia and while challenges remain, this progress has significantly increased confidence that the ultimate goal of societally acceptable (e.g. cost, safety, environmental considerations including waste disposal) central power production can be achieved. This progress has been shared by the two principal approaches to controlled thermonuclear fusion--magnetic confinement (MFE) and inertial confinement (ICF). ICF, the focus of this article, is complementary and symbiotic to MFE. As shown, ICF invokes spherical implosion of the fuel to achieve high density, pressures, and temperatures, inertially confining the plasma for times sufficient long (t {approx} 10{sup -10} sec) that {approx} 30% of the fuel undergoes thermonuclear fusion.

Campbell, E.M.; Hogan, W.J.

1999-08-12

138

14-3-3 fusion oncogenes in high-grade endometrial stromal sarcoma  

PubMed Central

14-3-3 proteins are ubiquitously expressed regulators of various cellular functions, including proliferation, metabolism, and differentiation, and altered 14-3-3 expression is associated with development and progression of cancer. We report a transforming 14-3-3 oncoprotein, which we identified through conventional cytogenetics and whole-transcriptome sequencing analysis as a highly recurrent genetic mechanism in a clinically aggressive form of uterine sarcoma: high-grade endometrial stromal sarcoma (ESS). The 14-3-3 oncoprotein results from a t(10;17) genomic rearrangement, leading to fusion between 14-3-3? (YWHAE) and either of two nearly identical FAM22 family members (FAM22A or FAM22B). Expression of YWHAE–FAM22 fusion oncoproteins was demonstrated by immunoblot in t(10;17)-bearing frozen tumor and cell line samples. YWHAE–FAM22 fusion gene knockdowns were performed with shRNAs and siRNAs targeting various FAM22A exons in an t(10;17)-bearing ESS cell line (ESS1): Fusion protein expression was inhibited, with corresponding reduction in cell growth and migration. YWHAE–FAM22 maintains a structurally and functionally intact 14-3-3? (YWHAE) protein-binding domain, which is directed to the nucleus by a FAM22 nuclear localization sequence. In contrast to classic ESS, harboring JAZF1 genetic fusions, YWHAE–FAM22 ESS display high-grade histologic features, a distinct gene-expression profile, and a more aggressive clinical course. Fluorescence in situ hybridization analysis demonstrated absolute specificity of YWHAE–FAM22A/B genetic rearrangement for high-grade ESS, with no fusions detected in other uterine and nonuterine mesenchymal tumors (55 tumor types, n = 827). These discoveries reveal diagnostically and therapeutically relevant models for characterizing aberrant 14-3-3 oncogenic functions. PMID:22223660

Lee, Cheng-Han; Ou, Wen-Bin; Mariño-Enriquez, Adrian; Zhu, Meijun; Mayeda, Mark; Wang, Yuexiang; Guo, Xiangqian; Brunner, Alayne L.; Amant, Frédéric; French, Christopher A.; West, Robert B.; McAlpine, Jessica N.; Gilks, C. Blake; Yaffe, Michael B.; Prentice, Leah M.; McPherson, Andrew; Jones, Steven J. M.; Marra, Marco A.; Shah, Sohrab P.; van de Rijn, Matt; Huntsman, David G.; Dal Cin, Paola; Debiec-Rychter, Maria; Nucci, Marisa R.; Fletcher, Jonathan A.

2012-01-01

139

PROGRESS TOWARD FULLY NONINDUCTIVE, HIGH BETA DISCHARGES IN DIII-D  

SciTech Connect

OAK-B135 Advanced Tokamak (AT) research in DIII-D focuses on developing a scientific basis for steady-state, high performance operation. For optimal performance, these experiments routinely operate with {beta} above the n = 1 no-wall limit, enabled by active feed-back control. The ideal wall {beta} limit is optimized by modifying the plasma shape, current and pressure profile. Present DIII-D AT experiments operate with f{sub BS} {approx} 50%-60%, with a long-term goal of {approx} 90%. Additional current is provided by neutral beam and electron cyclotron current drive, the latter being localized well away from the magnetic axis ({rho} {approx} 0.4-0.5). Guided by integrated modeling, recent experiments have produced discharges with {beta} {approx} 3%, {beta}{sub N} {approx} 3, f{sub BS} {approx} 55% and noninductive fraction f{sub NI} {approx} 90%. Additional control is anticipated using fast wave current drive to control the central current density.

GREENFIELD,CM; FERRON,JR; MURAKAMI,M; WADE,MR; BUDNY,RV; BURRELL,KH; CASPER,TA; DeBOO,JC; DOYLE,EJ; GAROFALO,AM; JAYAKUMAR,RJ; KESSEL,C; LAO,LL; LOHR,J; LUCE,TC; MAKOWSKI,MA; MENARD,JE; PETRIE,TW; PETTY,CC; PINSKER,RI; PRATER,R; POLITZER,PA; St JOHN,HE; TAYLOR,TS; WEST,WP; DIII-D NATIONAL TEAM

2003-08-01

140

Satellite data for high resolution offshore wind resource mapping: A data fusion approach M.B. Ben Ticha a,*  

E-print Network

Satellite data for high resolution offshore wind resource mapping: A data fusion approach M.B. Ben accurate high spatial and temporal resolutions wind measurements. Offshore, satellite data are an accurate radar, scatterometer, data fusion, offshore wind energy resource assessment. 1. INTRODUCTION Since

Paris-Sud XI, Université de

141

Multi-Sensor Fusion of Electro-Optic and Infrared Signals for High Resolution Visible Images: Part II  

E-print Network

the most discriminative feature from a set of features to determine the fusion rule. The proposed algorithmMulti-Sensor Fusion of Electro-Optic and Infrared Signals for High Resolution Visible Images: Part of high resolution and low noise level, but they cannot reflect information about the temperature

142

High Fusion Rates with Circular Plate Fixation for Four-corner Arthrodesis of the Wrist  

Microsoft Academic Search

Background   Scaphoid excision and four-corner fusion is commonly performed to reconstruct advanced scapholunate collapse and scaphoid\\u000a nonunion with collapse. Metallic plates were introduced for achieving fixation of the four carpal bones. Although the developer\\u000a reported high rates of fusion, several other early reports of circular plate fixation suggest higher complication rates and\\u000a inferior outcomes compared with traditional fixation techniques.\\u000a \\u000a \\u000a \\u000a Questions\\/Purposes  

Ben Bedford; S. Steven Yang

2010-01-01

143

High total dose irradiation experiments on fiber optic components for fusion reactor environments  

Microsoft Academic Search

Optical fiber technology is seriously considered for communication and monitoring applications during the operation and maintenance of future thermonuclear fusion reactors. Their environment is characterized, in particular, by possibly high gamma dose-rates and total doses up to 100 MGy. The feasibility of applying photonic technique in such intense radiation fields therefore needs to be assessed. Whereas many reports deal with

Francis Berghmans; Marco Van Uffelen; Antoine Nowodzinski; Benoit Brichard; Frans Vos; Philippe Jucker; Marc C. Decreton

1999-01-01

144

High-temperature fusion of nitrogen compounds at laser influence on refractory metals  

Microsoft Academic Search

The processes of laser burning and ignition on the surface of refractory metal (such as Zr, Ni, Hf) are researched in this paper. The regime of gas phase limit, at which the metal heating leads to the high temperature fusion of nitrogen compounds on their surface under condition Plimit. $GTR P has been performed, and it leads only to the

M. A. Arzuov; B. I. Gaynullin; S. A. Ubaidullaev

2002-01-01

145

NNSA Defense Programs Inertial Confinement Fusion Ignition and High Yield Campaign  

E-print Network

NNSA Defense Programs Inertial Confinement Fusion Ignition and High Yield Campaign Presented at overview · NIF Use Plan ­ Defense Science Board review (Ignition 2010) · Recent progress ­ NIF, OMEGA, Z. David H. Crandall Deputy for Technical Direction Joseph J. Maguire NA-11 Office of Defense Science

146

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

E-print Network

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

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

2013-04-09

147

Highly efficient, enantioselective synthesis of (+)-grandisol from a C2-symmetric bis(alpha,beta-butenolide).  

PubMed

[reaction: see text] A new, very efficient, enantioselective synthesis of the sexual attracting insect pheromone (+)-grandisol has been developed, in which the key step is the double [2 + 2] photocycloaddition of ethylene to a bis(alpha,beta-butenolide) readily available from D-mannitol. The C2 symmetry of the substrate and the appropriate protection of the central diol unit are the crucial features for the high diastereofacial discrimination during the cycloaddition process. PMID:10814272

de March, P; Figueredo, M; Font, J; Raya, J

2000-01-27

148

Fatigue crack growth behaviors of a new burn-resistant highly-stabilized beta titanium alloy  

Microsoft Academic Search

This article presents the fatigue crack growth (FCG) behaviors of a new burn-resistant highly-stabilized beta Ti40 alloy.\\u000a The FCG rates were analyzed. The fracture surfaces and the side surfaces of the test samples were explored. The results show\\u000a that frequency affects the cracking behaviors of Ti40 alloy. Temperature also plays an important role in Ti40 alloy cracking.\\u000a At room temperature

Huan Wu; Yongqing Zhao; Weidong Zeng; Li Qian

2009-01-01

149

Laser diagnostic for high-energy, laser fusion drivers  

SciTech Connect

A complete set of diagnostics for use on a frequency-tripled high-energy glass laser system is described. We employed high resolution imaging, temporal pulse-shape, beam bandwidth, phase-front, and precision energy instrumentation.

Burkhart, S.C.; Behrendt, W.; Smith, I.

1994-11-08

150

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

151

KSTAR Equilibrium Operating Space and Projected Stabilization at High Normalized Beta  

SciTech Connect

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

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

2011-01-01

152

Dynamic Formation of a Hot Field Reversed Configuration with Improved Confinement by Supersonic Merging of Two Colliding High-{beta} Compact Toroids  

SciTech Connect

A hot stable field-reversed configuration (FRC) has been produced in the C-2 experiment by colliding and merging two high-{beta} plasmoids preformed by the dynamic version of field-reversed {theta}-pinch technology. The merging process exhibits the highest poloidal flux amplification obtained in a magnetic confinement system (over tenfold increase). Most of the kinetic energy is converted into thermal energy with total temperature (T{sub i}+T{sub e}) exceeding 0.5 keV. The final FRC state exhibits a record FRC lifetime with flux confinement approaching classical values. These findings should have significant implications for fusion research and the physics of magnetic reconnection.

Binderbauer, M. W.; Guo, H. Y.; Tuszewski, M.; Putvinski, S.; Sevier, L.; Barnes, D.; Rostoker, N.; Anderson, M. G.; Andow, R.; Bonelli, L.; Brown, R.; Bui, D. Q.; Bystritskii, V.; Clary, R.; Cheung, A. H.; Conroy, K. D.; Deng, B. H.; Dettrick, S. A.; Douglass, J. D.; Feng, P. [Tri Alpha Energy, Inc., Post Office Box 7010, Rancho Santa Margarita, California 92688 (United States)

2010-07-23

153

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

154

Conceptual study on high performance blanket in a spherical tokamak fusion-driven transmuter  

Microsoft Academic Search

A preliminary conceptual design on high performance dual-cooled blanket of fusion-driven transmuter is presented based on neutronic calculation. The dual-cooled system has some attractive advantages when utilized in transmutation of HLW (High Level Wastes). The calculation results show that this kind of blanket could safely transmute about 6 ton minor actinides (produced by 170 GW(e) Year PWRs approximately) and 0.4

Yixue Chen; Yican Wu

2000-01-01

155

Options for the use of high temperature superconductor in tokamak fusion reactor designs  

Microsoft Academic Search

The use of high temperature superconductors (HTS) in long term tokamak fusion reactors is analyzed in this paper. The well-documented physical properties of high temperature superconductors are used in the evaluation. Short-sample wires and tapes of Bi2Sr2CanCun+1Oy materials, with n=1, 2 (referred to as BSCCO), and YBCO (YBa2CuO7?x) tapes approach their single-crystal performance limits. They provide a useful reference frame

L. Bromberg; M. Tekula; L. A El-Guebaly; R Miller

2001-01-01

156

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

SciTech Connect

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

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

1981-01-01

157

High-Damage-Threshold Pinhole for Glass Fusion Laser Applications  

SciTech Connect

We are investigating methods to fabricate high-damage-threshold spatial-filter pinholes that might not be susceptible to plasma closure for relatively high energies and long pulses. These are based on the observation that grazing-incidence reflection from glass can withstand in excess of 5 kJ/cm{sup 2} (normal to the beam) without plasma formation. The high damage threshold results from both the cos q spreading of the energy across the surface and the reflection of a large fraction of the energy from the surface, thereby greatly reducing the field strength within the medium.

Kumit, N.A.; Letzring, S.A.; Johnson, R.P.

1998-06-07

158

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

159

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

160

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

161

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

SciTech Connect

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

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

1993-07-01

162

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

SciTech Connect

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

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

1996-12-31

163

Quinine blocks the high conductance, calcium-activated potassium channel in rat pancreatic beta-cells.  

PubMed

The [Ca2+]i-activated K+-channel, one of the 3 K+ -channels described in pancreatic beta-cells, is a high conductance, voltage-dependent K+-channel. Quinine, known to block [Ca2+]i-activated K(+)-channels in other cells, has been described to block the silent phase between the bursts of glucose-evoked electrical activity in mouse pancreatic beta-cells, and to inhibit K+ efflux from rat pancreatic islets. We report here that quinine blocks the [Ca2+]i-activated K(+)-channel in rat pancreatic beta-cells from the external side of the membrane. We also show that the blockade is characterized by fast flickering of the K(+)-channel between the open and closed state. Mean open and closed times within bursts were found to be exponentially distributed, suggesting that the blockade by quinine involves obstruction on the K(+) flow through the open to be exponentially distributed, suggesting that the blockade by quinine involves obstruction on the K+ flow through the open channel. PMID:2404792

Mancilla, E; Rojas, E

1990-01-15

164

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

165

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

SciTech Connect

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

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

2011-01-04

166

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

167

Serum and plasma beta-carotene levels measured with an improved method of high-performance liquid chromatography.  

PubMed

An isocratic high-performance liquid chromatographic method specifically developed to allow simple and rapid determination of beta-carotene concentrations in serum and plasma is reported. Using a method modified from a previously published technique, serum and plasma proteins are denatured by exposure to perchloric acid, and beta-carotene is subsequently extracted into an organic matrix consisting of ethyl acetate-tetrahydrofuran (1:1); no evaporation step is required. Separation is achieved using isocratic elution from a reversed-phase C18 column with UV detection at 436 nm. Recovery of beta-carotene from water and plasma was greater than 98.1%; beta-carotene was stable in the extraction matrix for at least 4 h. Three anticoagulants (oxalate, citrate, and EDTA) caused losses of beta-carotene; perchloric acid and tetrahydrofuran could also destroy beta-carotene under certain conditions. Each run required less than 15 min; within-day coefficient of variation for identical samples averaged 2.3%, between-day coefficient of variation was 4.4% and sensitivity was better than 10 ng/ml. Stability of beta-carotene in plasma was also examined. This method permits a simple, rapid, sensitive, precise, and accurate determination of beta-carotene using 0.5 ml of serum or heparinized plasma. PMID:4008568

Nierenberg, D W

1985-05-01

168

Incomplete-fusion reactions for ?-ray spectroscopy: Application to the study of high-spin states in 234U  

NASA Astrophysics Data System (ADS)

Incomplete-fusion reactions occur when breakup of the projectile results in only part of the beam particle fusing with the target, the remnant being emitted with an energy equivalent to the beam velocity. Such reactions have been demonstrated to populate slightly neutron-rich nuclei compared to conventional fusion-evaporation reactions, opening possibilities for the study of nuclei along the neutron-rich side of the line of stability. Results from a study of 211Po are presented to illustrate the use of incomplete-fusion reactions for ?-ray spectroscopy. New results from a test-run which populated high-spin states in 234U via the 232Th(9Be,?3n) reaction are also presented. An interesting feature of the latter reaction is that the high fission probabilities for the compound nuclei which follow complete fusion, results in the residues from incomplete fusion forming the dominant residue channels.

Lane, G. J.; Dracoulis, G. D.; Byrne, A. P.; McGoram, T. R.; Poletti, A. R.

1999-09-01

169

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

170

A new high-temperature indentation device for characterization of materials for fusion applications  

NASA Astrophysics Data System (ADS)

For material characterization tests that simulate the operating conditions in a fusion reactor, high-temperature experiments on irradiated samples are necessary. After successful indentation investigations at room temperature, the next step is an adaption of the experiment to elevated temperatures. A high-temperature indentation device designed for this application was constructed and realized at the Karlsruhe Institute of Technology (KIT). This device will be installed in a hot cell of the Fusion Materials Laboratory, Institute for Applied Materials. A description of chosen solutions and construction details for realization of the device are given: the properties as well as the main parts of the new apparatus—sample heating and positioning, vacuum system, force actuator, and remote handling solutions—are described.

Albinski, B.; Schneider, H.-C.; Sacksteder, I.; Kraft, O.

2013-11-01

171

"Polarized" Fusion  

NASA Astrophysics Data System (ADS)

Increasing energy demand in view of limited supply, as well as environmental and nuclear-safety concerns leading to increased emphasis on renewable energy sources such as solar or wind energy are expected to focus public and scientific interest increasingly also on fusion energy. With the decision to build ITER (low-density magnetic confinement) and also continuing research on (high-density) inertial-confinement fusion (cf. the inauguration of the laser fusion facility at the Lawrence Livermore National Laboratory) prospects of fusion energy have probably entered a new era.

Schieck, Hans Paetz Gen.

172

High glucose inhibits glucose-6-phosphate dehydrogenase, leading to increased oxidative stress and beta-cell apoptosis.  

PubMed

Patients with type 2 diabetes lose beta cells, but the underlying mechanisms are incompletely understood. Glucose-6-phosphate dehydrogenase (G6PD) is the principal source of the major intracellular reductant, NADPH, which is required by many enzymes, including enzymes of the antioxidant pathway. Previous work from our laboratory has shown that high glucose impairs G6PD activity in endothelial and kidney cells, which leads to decreased cell survival. Pancreatic beta cells are highly sensitive to increased ROS. This study aimed to determine whether G6PD and NADPH play central roles in beta-cell survival. Human and mouse islets, MIN6 cell line, and G6PD deficient mice were studied. High glucose inhibited G6PD expression and activity. Inhibition of G6PD with siRNA led to increased ROS and apoptosis, decreased proliferation, and impaired insulin secretion. High glucose decreased insulin secretion, which was improved by overexpressing G6PD. G6PD-deficient mice had smaller islets and impaired glucose tolerance compared with control mice, which suggests that G6PD deficiency per se leads to beta-cell dysfunction and death. G6PD plays an important role in beta-cell function and survival. High-glucose-mediated decrease in G6PD activity may provide a mechanistic explanation for the gradual loss of beta cells in patients with diabetes. PMID:20032314

Zhang, Zhaoyun; Liew, Chong Wee; Handy, Diane E; Zhang, Yingyi; Leopold, Jane A; Hu, Ji; Guo, Lili; Kulkarni, Rohit N; Loscalzo, Joseph; Stanton, Robert C

2010-05-01

173

LWR spent fuel transmutation in a high power density fusion reactor  

Microsoft Academic Search

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

Sümer ?ahin; Mustafa Übeyli

2004-01-01

174

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

175

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

Microsoft Academic Search

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.

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

2011-01-01

176

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

177

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

Microsoft Academic Search

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

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

2009-01-01

178

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

179

High temperature low cycle fatigue in beta processed Ti-5Al-5Sn-2Zr-2Mo-0. 25Si  

SciTech Connect

The effects of ..beta.. heat treatment and ..beta..-work on microstructure and high temperature low cycle fatigue properties of Ti-5Al-5Sn-2Zr-2Mo-0.25Si were investigated. Strain control tests at total strains ranging from 1.2 to 2.5 pct were conducted at 427, 482, and 538/sup 0/C with frequencies of 10 and 0.4 cpm. The results showed shorter fatigue life at the higher temperature and lower freuency for all microstructural conditions. ..beta..-worked material with shorter ..cap alpha..-platelet structure showed the highest fatigue strength for all test conditions. At these high temperatures, fatigue cracks initiate along the ..cap alpha../..beta.. interfaces with longer initial cracks in the ..beta..-annealed condition which had longer interfaces. It is suggested that oxygen diffusion along the ..cap alpha../..beta.. interfaces is responsible for surface connected interfacial cracking leading to the observed temperature and frequency dependence. The better HTLCF life of the ..beta..-worked material is related to the shorter initial interface cracks.

Eylon, D. (Metcut-Materials Research Group, Wright-Patterson AFB, OH); Bartel, T.L.; Rosenblum, M.E.

1980-08-01

180

On the increase of predictive performance with high-level data fusion.  

PubMed

The combination of the different data sources for classification purposes, also called data fusion, can be done at different levels: low-level, i.e. concatenating data matrices, medium-level, i.e. concatenating data matrices after feature selection and high-level, i.e. combining model outputs. In this paper the predictive performance of high-level data fusion is investigated. Partial least squares is used on each of the data sets and dummy variables representing the classes are used as response variables. Based on the estimated responses ?(j) for data set j and class k, a Gaussian distribution p(g(k)|?(j)) is fitted. A simulation study is performed that shows the theoretical performance of high-level data fusion for two classes and two data sets. Within group correlations of the predicted responses of the two models and differences between the predictive ability of each of the separate models and the fused models are studied. Results show that the error rate is always less than or equal to the best performing subset and can theoretically approach zero. Negative within group correlations always improve the predictive performance. However, if the data sets have a joint basis, as with metabolomics data, this is not likely to happen. For equally performing individual classifiers the best results are expected for small within group correlations. Fusion of a non-predictive classifier with a classifier that exhibits discriminative ability lead to increased predictive performance if the within group correlations are strong. An example with real life data shows the applicability of the simulation results. PMID:21962346

Doeswijk, T G; Smilde, A K; Hageman, J A; Westerhuis, J A; van Eeuwijk, F A

2011-10-31

181

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

182

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

183

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

184

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

PubMed

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

Herl, Vanessa; Frankenstein, Jördis; Meitinger, Nadine; Müller-Uri, Frieder; Kreis, Wolfgang

2007-06-01

185

Translation and Capture of High-Density Field Reversed Configurations for Magnetized Target Fusion  

NASA Astrophysics Data System (ADS)

A physics demonstration of Magnetized Target Fusion (MTF) is being pursued by a collaborative team from Los Alamos National Laboratory and Air Force Research Laboratory. The LANL facility, known as the Field Reversed eXperiment --- Liner (FRX-L), focuses on the physics of producing high-density Field Reversed Configurations (FRCs), translating them, and capturing them in a static flux conserver. Observations of FRCs in translation and capture will be presented. The data suggest FRCs are formed at density above 10^22/m^3, translate over the one meter chamber at 97 km/s, and a captured portion having radius 4 cm lives for 10?s. The repeatability of FRC capture will be discussed in context of that necessary for MTF. This work is supported by the Office of Fusion Energy Sciences, and DOE/LANL contract DE-AC52-06NA25396.

Sieck, P. E.; Intrator, T. P.; Wurden, G. A.; Waganaar, W. J.; Cortez, R. J.; Oberto, R. J.

2009-11-01

186

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

187

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

188

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

189

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

NASA Astrophysics Data System (ADS)

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

Lincoln, David Louis

190

Metallurgical, chemical, and stress corrosion cracking characterization of high oxygen alpha+beta titanium-15Molybdenum  

NASA Astrophysics Data System (ADS)

Titanium and its alloys are used as biomaterials due to their excellent corrosion resistance, mechanical properties, superior biocompatibility, metallurgical properties and fatigue characteristics. Titanium implants, like all biomaterials, can have failures in-vivo during their service life. The predominant mechanism observed for titanium implant/device failures is corrosion fatigue. However, other failure mechanisms can be observed. One such failure mechanism is stress corrosion cracking. Stress corrosion cracking and its presence or absence in in-vivo failures of titanium and titanium alloys has historically been debated. Several researchers have stated that titanium and titanium alloys can fail due to stress corrosion cracking under physiological conditions when the oxygen weight percent exceeds 0.20. The purpose of this research was to evaluate and to compare metallurgical, chemical, and stress corrosion cracking (SCC) properties of two heats of alpha+beta Ti-15Mo with oxygen weight concentrations of approximately 0.18% (Heat UC30) and 0.73% (Heat UC32B). The results were compared to previous findings for beta Ti-15Mo, Grade 4 CP Ti, Ti-6A1-4V ELI and another low oxygen weight percent alpha+beta Ti-15Mo. Metallurgical evaluations showed that Heat UC30 had an inhomogeneous distribution of alpha and beta phases while Heat UC32B exhibited a homogenous microstructure. Heat treatment processes (annealing and aging) were completed on both heats to homogenize and to optimize the microstructures. Smooth and notched tensile test results showed that both heats had equal or superior tensile properties compared to CPTi and other Ti alloys. Corrosion resistance testing showed a variance in Heat UC30 samples while little variance was shown in Heat UC32B samples. Chemical composition results found that both alloys were within specification and internal melt limits. Smooth and notched samples for both Heat UC30 and Heat UC32B showed no evidence of SCC failure mechanisms in either distilled water or Ringer's solution as evident by the ductility ratios and SEM evaluation of the fracture surfaces. The variance in results from the corrosion resistance testing scans and SCC testing showed Heat UC30 was not homogenized through heat treatment processes. The positive results for the characterization of Heat UC32B (0.73% oxygen) warrants further research as its use as a high strength implantable biomaterial.

Williamson, Randall Scott

191

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

192

Highly radiation-resistant vacuum impregnation resin systems for fusion magnet insulation  

NASA Astrophysics Data System (ADS)

Magnets built for fusion devices such as the newly proposed Fusion Ignition Research Experiment (FIRE) need to be highly reliable, especially in a high radiation environment. Insulation materials are often the weak link in the design of superconducting magnets due to their sensitivity to high radiation doses, embrittlement at cryogenic temperatures, and the limitations on their fabricability. An insulation system capable of being vacuum impregnated with desirable properties such as a long pot-life, high strength, and excellent electrical integrity and which also provides high resistance to radiation would greatly improve magnet performance and reduce the manufacturing costs. A new class of insulation materials has been developed utilizing cyanate ester chemistries combined with other known radiation-resistant resins, such as bismaleimides and polyimides. These materials have been shown to meet the demanding requirements of the next generation of devices, such as FIRE. Post-irradiation testing to levels that exceed those required for FIRE showed no degradation in mechanical properties. In addition, the cyanate ester-based systems showed excellent performance at cryogenic temperatures and possess a wide range of processing variables, which will enable cost-effective fabrication of new magnets. This paper details the processing parameters, mechanical properties at 76 K and 4 K, as well as post-irradiation testing to dose levels surpassing 108 Gy.

Fabian, P. E.; Munshi, N. A.; Denis, R. J.

2002-05-01

193

Control of a high beta maneuvering reentry vehicle using dynamic inversion.  

SciTech Connect

The design of flight control systems for high performance maneuvering reentry vehicles presents a significant challenge to the control systems designer. These vehicles typically have a much higher ballistic coefficient than crewed vehicles like as the Space Shuttle or proposed crew return vehicles such as the X-38. Moreover, the missions of high performance vehicles usually require a steeper reentry flight path angle, followed by a pull-out into level flight. These vehicles then must transit the entire atmosphere and robustly perform the maneuvers required for the mission. The vehicles must also be flown with small static margins in order to perform the required maneuvers, which can result in highly nonlinear aerodynamic characteristics that frequently transition from being aerodynamically stable to unstable as angle of attack increases. The control system design technique of dynamic inversion has been applied successfully to both high performance aircraft and low beta reentry vehicles. The objective of this study was to explore the application of this technique to high performance maneuvering reentry vehicles, including the basic derivation of the dynamic inversion technique, followed by the extension of that technique to the use of tabular trim aerodynamic models in the controller. The dynamic inversion equations are developed for high performance vehicles and augmented to allow the selection of a desired response for the control system. A six degree of freedom simulation is used to evaluate the performance of the dynamic inversion approach, and results for both nominal and off nominal aerodynamic characteristics are presented.

Watts, Alfred Chapman

2005-05-01

194

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

NASA Technical Reports Server (NTRS)

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

Juhasz, Albert J.; Sawicki, Jerzy T.

2003-01-01

195

Spin selective x-ray absorption spectroscopy: Demonstration using high resolution Fe [ital K][beta] fluorescence  

SciTech Connect

In this letter it is shown that high resolution Fe [ital K][beta] excitation spectra can be used to separately probe empty spin-up and spin-down final states. Spin-selective x-ray absorption spectra were obtained by selectively monitoring different regions of the [ital K][beta] emission. The fluorescence was excited with monochromatized synchrotron radiation and analyzed using a spherically bent Ge(620) crystal. Spin--polarization was demonstrated by showing that the 1[ital s][r arrow]3[ital d] transition at the Fe [ital K] edge is seen with [ital K][beta][sub 1,3] detection, but missing in the excitation spectrum using [ital K][beta][prime] detection. The spin--polarization is also confirmed by ligand field atomic multiplet calculations that reproduce the [ital K][beta] spectra. Calculations are presented showing the applicability of spin--polarized [ital K][beta] detection to nearly all first transition metal ions.

Peng, G.; Wang, X.; Randall, C.R.; Moore, J.A.; Cramer, S.P. (Department of Applied Science, University of California at Davis, Davis, California 95616 (United States) Energy Environment Division, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States))

1994-11-14

196

Magnetized plasma flow injection into tokamak and high-beta compact torus plasmas  

NASA Astrophysics Data System (ADS)

As an application of a magnetized coaxial plasma gun (MCPG), magnetic helicity injection via injection of a highly elongated compact torus (magnetized plasma flow: MPF) has been conducted on both tokamak and field-reversed configuration (FRC) plasmas. The injected plasmoid has significant amounts of helicity and particle contents and has been proposed as a fueling and a current drive method for various torus systems. In the FRC, MPF is expected to generate partially spherical tokamak like FRC equilibrium by injecting a significant amount of magnetic helicity. As a circumstantial evidence of the modified equilibrium, suppressed rotational instability with toroidal mode number n = 2. MPF injection experiments have also been applied to the STOR-M tokamak as a start-up and current drive method. Differences in the responses of targets especially relation with beta value and the self-organization feature will be studied.

Matsunaga, Hiroyuki; Komoriya, Yuuki; Tazawa, Hiroyasu; Asai, Tomohiko; Takahashi, Tsutomu; Steinhauer, Loren; Itagaki, Hirotomo; Onchi, Takumi; Hirose, Akira

2010-11-01

197

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. PMID:24713415

2014-01-01

198

Nonlinear evolution of a large-amplitude circularly polarized Alfven wave: High beta  

NASA Technical Reports Server (NTRS)

The nonlinear dynamics following saturation of the parametric instabilities of a monochromatic field-aligned large-amplitude circularly polarized Alfven wave is investigated via direct numerical simulation in the case of high plasma beta and no wave dispersion. The magnetohydrodynamic (MHD) code permits nonlinear couplings in the parallel direction to the ambient magnetic field and one perpendicular direction. Compressibility is included in the form of a polytropic equation of state. Turbulent cascades develop after saturation of two coupled oblique three-wave parametric instabilities; one of which is an oblique filamentationlike instability reported earlier. Remnants of the parametric processes, as well as of the original Alfven pump wave, persist during late nonlinear times. Nearly incompressible MHD features such as spectral anisotropies appear as well.

Ghosh, S.; Vinas, A. F.; Goldstein, M. L.

1994-01-01

199

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

200

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

201

Two-photon fusion in high-energy electron-nucleus scattering  

SciTech Connect

Experimental studies of meson production through two-photon fusion in inelastic electron-nucleus scattering are now under way. A high-energy photon radiated by the incident electron is fused with a soft photon radiated by the nucleus to create the meson. The process takes place in the small-angle Coulomb region of nuclear scattering. We expound the theory for this production process as well as its interference with coherent-radiative-meson production. In particular, we investigate the distortion of the electron wave function due to multiple-Coulomb scattering.

Faeldt, Goeran [Department of Physics and Astronomy, Uppsala University, Box 516, S-751 20 Uppsala (Sweden)

2011-04-15

202

Nuclear Fusion prize laudation Nuclear Fusion prize laudation  

NASA Astrophysics Data System (ADS)

Clean energy in abundance will be of critical importance to the pursuit of world peace and development. As part of the IAEA's activities to facilitate the dissemination of fusion related science and technology, the journal Nuclear Fusion is intended to contribute to the realization of such energy from fusion. In 2010, we celebrated the 50th anniversary of the IAEA journal. The excellence of research published in the journal is attested to by its high citation index. The IAEA recognizes excellence by means of an annual prize awarded to the authors of papers judged to have made the greatest impact. On the occasion of the 2010 IAEA Fusion Energy Conference in Daejeon, Republic of Korea at the welcome dinner hosted by the city of Daejeon, we celebrated the achievements of the 2009 and 2010 Nuclear Fusion prize winners. Steve Sabbagh, from the Department of Applied Physics and Applied Mathematics, Columbia University, New York is the winner of the 2009 award for his paper: 'Resistive wall stabilized operation in rotating high beta NSTX plasmas' [1]. This is a landmark paper which reports record parameters of beta in a large spherical torus plasma and presents a thorough investigation of the physics of resistive wall mode (RWM) instability. The paper makes a significant contribution to the critical topic of RWM stabilization. John Rice, from the Plasma Science and Fusion Center, MIT, Cambridge is the winner of the 2010 award for his paper: 'Inter-machine comparison of intrinsic toroidal rotation in tokamaks' [2]. The 2010 award is for a seminal paper that analyzes results across a range of machines in order to develop a universal scaling that can be used to predict intrinsic rotation. This paper has already triggered a wealth of experimental and theoretical work. I congratulate both authors and their colleagues on these exceptional papers. W. Burkart Deputy Director General Department of Nuclear Sciences and Applications International Atomic Energy Agency, Vienna, Austria References [1] Sabbagh S. et al 2006 Nucl. Fusion 46 635-44 [2] Rice J.E. et al 2007 Nucl. Fusion 47 1618-24

Burkart, W.

2011-01-01

203

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

204

High-pressure dissociation of the beta 2-dimer of tryptophan synthase from Escherichia coli monitored by sucrose gradient centrifugation.  

PubMed

The isolated beta 2-dimer of Escherichia coli tryptophan synthase exhibits reversible high-pressure deactivation and hybridization with an equilibrium transition at 690 and 870 bar for the apoenzyme and holoenzyme, respectively. To investigate the hypothetical dissociation mechanism ultracentrifugal analysis has been applied. In a conventional swing-out rotor (r(max) = 16 cm, fill-height 9 cm) a pressure gradient of 1 less than p less than 1840 bar is formed at maximum speed (40 000 rpm). Using a sucrose gradient to stabilize the particle distribution, pressure-dependent alterations of the state of association of oligomeric systems may be determined. In the present experiments ovalbumin (with a molecular mass close to the beta-monomer) has been used as a reference. The radial sedimentation velocity of the beta 2-dimer (in 5-20% sucrose, 10 degrees C) is found to decrease significantly at p approximately equal to 850 bar. From the slopes in an r-r(degrees) vs t plot the limiting values for the particle weight at the meniscus and the bottom of the tube are found to be the beta 2-dimer (M(r) = 85 800) and the beta-monomer (M(r) = 42 900), thus proving pressure-dependent dissociation. Since sucrose stabilizes the native quaternary structure, the beta 2 leads to 2 beta transition is shifted towards higher pressures compared to the dissociation in standard buffer. Conventional quench experiments in high-pressure cells in the presence of 13% (w/v) sucrose confirm the result of the sucrose gradient centrifugation with respect to the critical pressure where deactivation (and dissociation) occur. PMID:6378669

Seifert, T; Bartholmes, P; Jaenicke, R

1984-08-01

205

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

206

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

207

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

208

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

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

209

Eukaryotic beta-alanine synthases are functionally related but have a high degree of structural diversity.  

PubMed Central

beta-Alanine synthase (EC 3.5.1.6), which catalyzes the final step of pyrimidine catabolism, has only been characterized in mammals. A Saccharomyces kluyveri pyd3 mutant that is unable to grow on N-carbamyl-beta-alanine as the sole nitrogen source and exhibits diminished beta-alanine synthase activity was used to clone analogous genes from different eukaryotes. Putative PYD3 sequences from the yeast S. kluyveri, the slime mold Dictyostelium discoideum, and the fruit fly Drosophila melanogaster complemented the pyd3 defect. When the S. kluyveri PYD3 gene was expressed in S. cerevisiae, which has no pyrimidine catabolic pathway, it enabled growth on N-carbamyl-beta-alanine as the sole nitrogen source. The D. discoideum and D. melanogaster PYD3 gene products are similar to mammalian beta-alanine synthases. In contrast, the S. kluyveri protein is quite different from these and more similar to bacterial N-carbamyl amidohydrolases. All three beta-alanine synthases are to some degree related to various aspartate transcarbamylases, which catalyze the second step of the de novo pyrimidine biosynthetic pathway. PYD3 expression in yeast seems to be inducible by dihydrouracil and N-carbamyl-beta-alanine, but not by uracil. This work establishes S. kluyveri as a model organism for studying pyrimidine degradation and beta-alanine production in eukaryotes. PMID:11454750

Gojkovi?, Z; Sandrini, M P; Piskur, J

2001-01-01

210

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

211

High-resolution polarization observations inside spectral lines of magnetic Ap stars. I. Instrumentation and observations of. beta. Coronae Borealis  

Microsoft Academic Search

We have constructed a coude photon-counting polarimeter capable of attaining (with a Fabry-Perot interferometer) a high resolution. A description of the instrument is given, with a discussion of various sources of systematic error in the polarimetry. Observations of linear and circular polarization in the spectrum of the Ap star ..beta.. Coronae Borealis, throughout the magnetic cycle, are obtained across an

E. F. Borra; A. H. Vaughan

1977-01-01

212

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

E-print Network

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

Juha Peltoniemi

2009-11-27

213

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

PubMed

Deuterium-tritium inertial confinement fusion implosion experiments on the National Ignition Facility have demonstrated yields ranging from 0.8 to 7×10(14), and record fuel areal densities of 0.7 to 1.3 g/cm2. These implosions use hohlraums irradiated with shaped laser pulses of 1.5-1.9 MJ energy. The laser peak power and duration at peak power were varied, as were the capsule ablator dopant concentrations and shell thicknesses. We quantify the level of hydrodynamic instability mix of the ablator into the hot spot from the measured elevated absolute x-ray emission of the hot spot. We observe that DT neutron yield and ion temperature decrease abruptly as the hot spot mix mass increases above several hundred ng. The comparison with radiation-hydrodynamic modeling indicates that low mode asymmetries and increased ablator surface perturbations may be responsible for the current performance. PMID:24010449

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

2013-08-23

214

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

NASA Astrophysics Data System (ADS)

Deuterium-tritium inertial confinement fusion implosion experiments on the National Ignition Facility have demonstrated yields ranging from 0.8 to 7×1014, and record fuel areal densities of 0.7 to 1.3g/cm2. These implosions use hohlraums irradiated with shaped laser pulses of 1.5-1.9 MJ energy. The laser peak power and duration at peak power were varied, as were the capsule ablator dopant concentrations and shell thicknesses. We quantify the level of hydrodynamic instability mix of the ablator into the hot spot from the measured elevated absolute x-ray emission of the hot spot. We observe that DT neutron yield and ion temperature decrease abruptly as the hot spot mix mass increases above several hundred ng. The comparison with radiation-hydrodynamic modeling indicates that low mode asymmetries and increased ablator surface perturbations may be responsible for the current performance.

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

2013-08-01

215

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

NASA Astrophysics Data System (ADS)

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

Jung, Cheolkon; Yang, Yanru; Jiao, Licheng

2013-10-01

216

Zr-zeolite beta: a new heterogeneous catalyst system for the highly selective cascade transformation of citral to (+/-)-menthol.  

PubMed

The transformation of citral to menthols involves hydrogenation steps as well as cyclisation of the intermediate, citronellal. The ability of Zr-zeolite beta to catalyse the cyclisation with high diastereoselectivity to (+/-)-isopulegol is the critical step in this cascade transformation. Bifunctional catalysts containing nickel or rhodium supported on Zr-zeolite beta gave menthols in yields of 87-89% and an excellent diastereoselectivity of 94% for the desired (+/-)-menthol. Dual catalyst systems of Zr-zeolite beta and nano-dispersed Ni on an MCM-41 support were equally effective and have the added advantage that the rates of the acid- and hydrogenation-catalysed steps can be independently varied. By applying a pressure ramp of 0.2-2 MPa, the yield of menthols could be increased to 95%, with 94% diastereoselectivity for (+/-)-menthol. The low initial pressure minimises the rates of competing hydrogenation reactions to byproducts such as citronellol and 3,7-dimethyloctanol. PMID:19132702

Nie, Yuntong; Jaenicke, Stephan; Chuah, Gaik-Khuan

2009-01-01

217

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

PubMed Central

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

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

2014-01-01

218

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

E-print Network

High-Resolution Depth Maps Based on TOF-Stereo Fusion Vineet Gandhi, Jan Cech, and Radu Horaud cameras. High-resolution depth maps can be obtained using stereo matching, but this often fails to construct accurate depth maps of weakly/repetitively textured scenes, or if the scene exhibits complex self

Paris-Sud XI, Université de

219

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

SciTech Connect

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

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

1988-01-01

220

High-level multifunction radar simulation for studying the performance of multisensor data fusion systems  

NASA Astrophysics Data System (ADS)

This paper presents the basic requirements for a simulation of the main capabilities of a shipborne MultiFunction Radar (MFR) that can be used in conjunction with other sensor simulations in scenarios for studying Multi Sensor Data Fusion (MSDF) systems. This simulation is being used to support an ongoing joint effort (Canada - The Netherlands) in the development of MSDF testbeds. This joint effort is referred as Joint-FACET (Fusion Algorithms & Concepts Exploration Testbed), a highly modular and flexible series of applications that is capable of processing both real and synthetic input data. The question raised here is how realistic should the sensor simulations be to trust the MSDF performance assessment? A partial answer to this question is that at least, the dominant perturbing effects on sensor detection (true or false) are sufficiently represented. Following this philosophy, the MFR model, presented here, takes into account sensor's design parameters and external environmental effects such as clutter, propagation and jamming. Previous radar simulations capture most of these dominant effects. In this paper the emphasis is on an MFR scheduler which is the key element that needs to be added to the previous simulations to represent the MFR capability to search and track a large number of targets and at the same time support a large number of (semi-active) surface-to-air missiles (SAM) for the engagement of multiple hostile targets.

Huizing, Albert G.; Bosse, Eloi

1998-07-01

221

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

222

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

NASA Astrophysics Data System (ADS)

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

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

2012-10-01

223

High precision study of muon catalyzed fusion in D2 and HD gas  

NASA Astrophysics Data System (ADS)

Muon catalyzed dd fusion in D2 and HD gases in the temperature range from 28 to 350 K was investigated in a series of experiments based on a time-projection ionization chamber operating with pure hydrogen. All main observables in this reaction chain were measured with high absolute precision including the resonant and non-resonant dd? formation rates, the rate for hyperfine transitions in d? atoms, the branching ratio of the two charge symmetric fusion channels 3He + n and t + p and the muon sticking probability. The report presents the final analysis of the data together with a comprehensive comparison with calculations based on recent ?CF theories. The energy of the loosely bound dd? state with quantum numbers J = 1, ? = 1, which is central to the mechanism of resonant molecule formation, is extracted with precision ?11(fit) = -1.9651(7) eV. in impressive agreement with the latest theoretical results ?11(theory) = -1.9646 eV.

Balin, D. V.; Ganzha, V. A.; Kozlov, S. M.; Maev, E. M.; Petrov, G. E.; Soroka, M. A.; Schapkin, G. N.; Semenchuk, G. G.; Trofimov, V. A.; Vasiliev, A. A.; Vorobyov, A. A.; Voropaev, N. I.; Petitjean, C.; Gartner, B.; Lauss, B.; Marton, J.; Zmeskal, J.; Case, T.; Crowe, K. M.; Kammel, P.; Hartmann, F. J.; Faifman, M. P.

2011-03-01

224

Spinal fusion  

MedlinePLUS

... Anterior spinal fusion; Spine surgery - spinal fusion; Low back pain - fusion; Herniated disk - fusion ... If you had chronic back pain before surgery, you will likely still have some pain afterward. Spinal fusion is unlikely to take away all your pain ...

225

Review of fusion synfuels  

SciTech Connect

Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Depending on design, electric generation efficiencies of approx. 40 to 60% and hydrogen production efficiencies by high-temperature electrolysis of approx. 50 to 65% are projected for fusion reactors using high-temperatures blankets. Fusion/coal symbiotic systems appear economically promising for the first generation of commercial fusion synfuels plants. Coal production requirements and the environmental effects of large-scale coal usage would be greatly reduced by a fusion/coal system. In the long term, there could be a gradual transition to an inexhaustible energy system based solely on fusion.

Fillo, J.A.

1980-01-01

226

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 PMID:8093006

Hildebrand, A; Romarís, M; Rasmussen, L M; Heinegård, D; Twardzik, D R; Border, W A; Ruoslahti, E

1994-01-01

227

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

228

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

229

Effect of solvent on absorption spectra of all-trans-{beta}-carotene under high pressure  

SciTech Connect

The absorption spectra of all-trans-{beta}-carotene in n-hexane and carbon disulfide (CS{sub 2}) solutions are measured under high pressure at ambient temperature. The common redshift and broadening in the spectra are observed. Simulation of the absorption spectra was performed by using the time-domain formula of the stochastic model. The pressure dependence of the 0-0 band wavenumber is in agreement with the Bayliss theory at pressure higher than 0.2 GPa. The deviation of the linearity at lower pressure is ascribed to the reorientation of the solvent molecules. Both the redshift and broadening are stronger in CS{sub 2} than that in n-hexane because of the more sensitive pressure dependence of dispersive interactions in CS{sub 2} solution. The effect of pressure on the transition moment is explained with the aid of a simple model involving the relative dimension, location, and orientation of the solute and solvent molecules. The implication of these results for light-harvesting functions of carotenoids in photosynthesis is also discussed.

Liu, W. L.; Zheng, Z. R.; Liu, Z. G.; Zhu, R. B.; Wu, W. Z.; Li, A. H.; Yang, Y. Q. [Center for Condensed Matter Science and Technology, Harbin Institute of Technology, Harbin 150001 (China); Dai, Z. F. [Nanobiotechnology and Biosensor Lab, Bio-X Center, Harbin Institute of Technology, Harbin 150001 (China); Su, W. H. [Center for Condensed Matter Science and Technology, Harbin Institute of Technology, Harbin 150001 (China); Department of Physics, Ji Lin University, Changchun 130023 (China)

2008-03-28

230

Calibration and test measurements of a high purety germanium beta spectrometer  

Microsoft Academic Search

Calibration measurements of an on-line beta spectrometer are described. Distortions of the measured spectra, caused by the detection step, are discussed. A correction of the beta spectrum for coincidental gamma rays was introduced and put into the fitting program BCONT. Using a Co56 source, a performance test of the correction was carried out. The fitted Q-value (4566.54 (1.92) keV) agrees

P. Coops

1983-01-01

231

High-temperature fusion of nitrogen compounds at laser influence on refractory metals  

NASA Astrophysics Data System (ADS)

The processes of laser burning and ignition on the surface of refractory metal (such as Zr, Ni, Hf) are researched in this paper. The regime of gas phase limit, at which the metal heating leads to the high temperature fusion of nitrogen compounds on their surface under condition Plimit. P has been performed, and it leads only to the creation of oxide compounds at Plimit. < P. It is shown that nitrogen creation has been a sharp appearance of new phase in the target heating dynamics. It is possible that its diagnostic as a non-stable metal burning product in the air could be done by optical method registration of non- monotonous changing of reflect capability R of the foliated system 'metal - oxide'.

Arzuov, M. A.; Gaynullin, B. I.; Ubaidullaev, S. A.

2002-04-01

232

APPLICATIONS OF NEW TECHNOLOGY FOR PRODUCTION OF HIGH POWER MILLIMETER WAVES TO MAGNETIC FUSION RESEARCH  

SciTech Connect

Although research on magnetically confined fusion plasmas has been carried out for a half century, for most of this time control of the temperature, density and current density profiles has been limited and transient. Now, high power long pulse gyrotron systems with excellent reliability are coming on line, which can provide non-inductively driven currents and electron heating leading to higher plasma performance and continuous operation in reactor relevant regimes. The precision of the location at which heating and current drive are applied has also made it possible to suppress certain classes of plasma instabilities. Basic physics of electron cyclotron current drive and heating are understood and these new technological capabilities are being exploited in magnetic confinement devices worldwide.

J. LOHR

2002-08-01

233

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

234

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

235

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 PMID:24942975

2014-01-01

236

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

PubMed Central

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

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

2013-01-01

237

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

238

Formation of a long-lived hot field reversed configuration by dynamically merging two colliding high-{beta} compact toroids  

SciTech Connect

A high temperature field reversed configuration (FRC) has been produced in the newly built, world's largest compact toroid (CT) facility, C-2, by colliding and merging two high-{beta} CTs produced using the advanced field-reversed {theta}-pinch technology. This long-lived, stable merged state exhibits the following key properties: (1) apparent increase in the poloidal flux from the first pass to the final merged state, (2) significantly improved confinement compared to conventional {theta}-pinch FRCs with flux decay rates approaching classical values in some cases, (3) strong conversion from kinetic energy into thermal energy with total temperature (T{sub e} + T{sub i}) exceeding 0.5 keV, predominantly into the ion channel. Detailed modeling using a new 2-D resistive magnetohydrodynamic (MHD) code, LamyRidge, has demonstrated, for the first time, the formation, translation, and merging/reconnection dynamics of such extremely high-{beta} plasmas.

Guo, H. Y.; Binderbauer, M. W.; Barnes, D.; Putvinski, S.; Rostoker, N.; Sevier, L.; Tuszewski, M.; Anderson, M. G.; Andow, R.; Bonelli, L.; Brown, R.; Bui, D. Q.; Bystritskii, V.; Clary, R.; Cheung, A. H.; Conroy, K. D.; Deng, B. H.; Dettrick, S. A.; Douglass, J. D.; Feng, P. [Tri Alpha Energy, Inc., P.O. Box 7010, Rancho Santa Margarita, California 92688 (United States)

2011-05-15

239

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

E-print Network

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

Ceyssens, Frederik; Driesen, Maarten

2014-01-01

240

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

241

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

242

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

243

Fusion Engineering and Design 3940 (1998) 287294 Response of plasma-facing materials to high transient heat  

E-print Network

Fusion Engineering and Design 39­40 (1998) 287­294 Response of plasma-facing materials to high from a plasma onto a material surface triggers a sequence of dynamic plasma­material interaction experiments were carried out in the TEXTOR tokamak. The materials exposed to the plasma were carbon fibre

Harilal, S. S.

244

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

SciTech Connect

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

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

1982-01-01

245

Robertsonian fusions, pericentromeric repeat organization and evolution: a case study within a highly polymorphic rodent species, Gerbillus nigeriae.  

PubMed

Pericentromeric repeats have been claimed to mediate centric fusions through heterologous recombination of arrays of tandemly repeated and highly homogenized motifs. However, mammalian case studies are essentially restricted to pathologic fusions in human, or to the house mouse Roberstonian (Rb) races. We here provide an example in a wild gerbil rodent, Gerbillus nigeriae, which displays an extensive Rb polymorphism, with 2n ranging between 2n = 60 and 74. The distribution of two closely related repeats, GERB1 and GERB2 that were previously isolated by Volobouev et al. (Chromosoma 104:252-259, 1995) in this African species, were investigated in the genomes of seven individuals with various diploid numbers. Our results clearly show that GERB1 and GERB2 are organized in a non-random manner, with GERB2 and GERB1 being clearly juxtacentromeric and centromeric, respectively. Finally, cloning and sequencing revealed that, unlike GERB2, GERB1 monomers display a more homogeneous organization at both the nucleotide and structural levels. Altogether, our results point toward a pivotal role of GERB1 repeats in the mediation of Rb fusions through heterologous recombination, with some evidence of subsequent loss of repeats after the Rb fusion during the course of evolution of metacentric elements. Moreover, the repeat pattern observed in G. nigeriae closely matches the organization and sequence structure of satellite DNAs described in human acrocentrics. Consequently, G. nigeriae appears as an additional model for the study of repeat evolution and its role in centric fusions and their consequences in mammals. PMID:20361248

Gauthier, Philippe; Hima, Karmadine; Dobigny, Gauthier

2010-06-01

246

High-throughput luminescent reporter of insulin secretion for discovering regulators of pancreatic Beta-cell function.  

PubMed

Defects in insulin secretion play a central role in the pathogenesis of type 2 diabetes, yet the mechanisms driving beta-cell dysfunction remain poorly understood, and therapies to preserve glucose-dependent insulin release are inadequate. We report a luminescent insulin secretion assay that enables large-scale investigations of beta-cell function, created by inserting Gaussia luciferase into the C-peptide portion of proinsulin. Beta-cell lines expressing this construct cosecrete luciferase and insulin in close correlation, under both standard conditions or when stressed by cytokines, fatty acids, or ER toxins. We adapted the reporter for high-throughput assays and performed a 1,600-compound pilot screen, which identified several classes of drugs inhibiting secretion, as well as glucose-potentiated secretagogues that were confirmed to have activity in primary human islets. Requiring 40-fold less time and expense than the traditional ELISA, this assay may accelerate the identification of pathways governing insulin secretion and compounds that safely augment beta-cell function in diabetes. PMID:25565210

Burns, Sean M; Vetere, Amedeo; Walpita, Deepika; Dan?ík, Vlado; Khodier, Carol; Perez, Jose; Clemons, Paul A; Wagner, Bridget K; Altshuler, David

2015-01-01

247

The crystal structure of Ba-{beta}-alumina materials for high-temperature catalytic combustion  

SciTech Connect

Structure refinement through Rietveld analysis has been performed on a series of Ba-Al-O samples with Al/Ba ratios in the range 9-14. This material is considered for its potential use in catalytic combustion. The results show that different {beta}-Al{sub 2}O{sub 3}-type structures are obtained upon calcination at 1670 K depending on the AlBa ratio. A {beta}{sub II}-Al{sub 2}O{sub 3} phase forms for the lowest AlBa ratio and a {beta}{sub I}-Al{sub 2}O{sub 3} forms for the highest one. Small amounts of additional phases are present in the samples with the border compositions. For an in-between composition (Al/Ba = 12) a monophasic sample is obtained with crystal structure and calculated cell parameters intermediate between those of {beta}{sub I} and {beta}{sub II}. The sample with the intermediate composition exhibits the highest surface area. A strict relationship between surface area and aspect ratio of the crystallites has been observed. This indicates that the sintering resistance of these materials derives from the suppression of crystal growth along the crystallographic axis c. Experimental data also indicate that sintering resistance is closely related to Ba content.

Groppi, G.; Assandri, F.; Cristiani, C. [G. Natta del Politecnico, Milano (Italy)] [and others] [G. Natta del Politecnico, Milano (Italy); and others

1995-02-01

248

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

PubMed

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

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

2015-02-01

249

Generation of a high-titer retroviral vector capable of expressing high levels of the human beta-globin gene.  

PubMed Central

Retrovirus-mediated gene transfer into hematopoietic cells may provide a means of treating both inherited and acquired diseases involving hematopoietic cells. Implementation of this approach for disorders resulting from mutations affecting the beta-globin gene (e.g., beta-thalassemia and sickle cell anemia), however, has been hampered by the inability to generate recombinant viruses able to efficiently and faithfully transmit the necessary sequences for appropriate gene expression. We have addressed this problem by carefully examining the interactions between retroviral and beta-globin gene sequences which affect vector transmission, stability, and expression. First, we examined the transmission properties of a large number of different recombinant proviral genomes which vary both in the precise nature of vector, beta-globin structural gene, and locus control region (LCR) core sequences incorporated and in the placement and orientation of those sequences. Through this analysis, we identified one specific vector, termed M beta 6L, which carries both the human beta-globin gene and core elements HS2, HS3, and HS4 from the LCR and faithfully transmits recombinant proviral sequences to cells with titers greater than 10(6) per ml. Populations of murine erythroleukemia (MEL) cells transduced by this virus expressed levels of human beta-globin transcript which, on a per gene copy basis, were 78% of the levels detected in an MEL-derived cell line, Hu11, which carries human chromosome 11, the site of the beta-globin locus. Analysis of individual transduced MEL cell clones, however, indicated that, while expression was detected in every clone tested (n = 17), the levels of human beta-globin treatment varied between 4% and 146% of the levels in Hu11. This clonal variation in expression levels suggests that small beta-globin LCR sequences may not provide for as strict chromosomal position-independent expression of beta-globin as previously suspected, at least in the context of retrovirus-mediated gene transfer. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:7624311

Sadelain, M; Wang, C H; Antoniou, M; Grosveld, F; Mulligan, R C

1995-01-01

250

Co-existence of whistler waves with kinetic Alfven wave turbulence for the high-beta solar wind plasma  

SciTech Connect

It is shown that the dispersion relation for whistler waves is identical for a high or low beta plasma. Furthermore, in the high-beta solar wind plasma, whistler waves meet the Landau resonance with electrons for velocities less than the thermal speed, and consequently, the electric force is small compared to the mirror force. As whistlers propagate through the inhomogeneous solar wind, the perpendicular wave number increases through refraction, increasing the Landau damping rate. However, the whistlers can survive because the background kinetic Alfven wave (KAW) turbulence creates a plateau by quasilinear (QL) diffusion in the solar wind electron distribution at small velocities. It is found that for whistler energy density of only {approx}10{sup -3} that of the kinetic Alfven waves, the quasilinear diffusion rate due to whistlers is comparable to KAW. Thus, very small amplitude whistler turbulence can have a significant consequence on the evolution of the solar wind electron distribution function.

Mithaiwala, Manish; Crabtree, Chris; Ganguli, Gurudas [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375-5346 (United States); Rudakov, Leonid [Icarus Research Inc., P.O. Box 30780, Bethesda, Maryland 20824-0780 (United States)

2012-10-15

251

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

PubMed

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

König, M A; Boszczyk, B M

2012-03-01

252

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

253

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

254

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

PubMed Central

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

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

2014-01-01

255

Highly diverse chromoviruses of Beta vulgaris are classified by chromodomains and chromosomal integration  

PubMed Central

Background Chromoviruses are one of the three genera of Ty3-gypsy long terminal repeat (LTR) retrotransposons, and are present in high copy numbers in plant genomes. They are widely distributed within the plant kingdom, with representatives even in lower plants such as green and red algae. Their hallmark is the presence of a chromodomain at the C-terminus of the integrase. The chromodomain exhibits structural characteristics similar to proteins of the heterochromatin protein 1 (HP1) family, which mediate the binding of each chromovirus type to specific histone variants. A specific integration via the chromodomain has been shown for only a few chromoviruses. However, a detailed study of different chromoviral clades populating a single plant genome has not yet been carried out. Results We conducted a comprehensive survey of chromoviruses within the Beta vulgaris (sugar beet) genome, and found a highly diverse chromovirus population, with significant differences in element size, primarily caused by their flanking LTRs. In total, we identified and annotated full-length members of 16 families belonging to the four plant chromoviral clades: CRM, Tekay, Reina, and Galadriel. The families within each clade are structurally highly conserved; in particular, the position of the chromodomain coding region relative to the polypurine tract is clade-specific. Two distinct groups of chromodomains were identified. The group II chromodomain was present in three chromoviral clades, whereas families of the CRM clade contained a more divergent motif. Physical mapping using representatives of all four clades identified a clade-specific integration pattern. For some chromoviral families, we detected the presence of expressed sequence tags, indicating transcriptional activity. Conclusions We present a detailed study of chromoviruses, belonging to the four major clades, which populate a single plant genome. Our results illustrate the diversity and family structure of B. vulgaris chromoviruses, and emphasize the role of chromodomains in the targeted integration of these viruses. We suggest that the diverse sets of plant chromoviruses with their different localization patterns might help to facilitate plant-genome organization in a structural and functional manner. PMID:23448600

2013-01-01

256

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

Microsoft Academic Search

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

D. G. Kolman; J. R. Scully

1997-01-01

257

Methylation of phenol over high-silica beta zeolite: Effect of zeolite acidity and crystal size on catalyst behaviour  

Microsoft Academic Search

A systematic investigation was carried out to elucidate several aspects of the gas\\/solid methylation of phenol over high Si\\/Al ratio beta-structured zeolite in protonated form, characterised by various techniques, including XRD, SEM, BET, ICP, FTIR, TGA, microcalorimetry, and modeling by ab initio calculations. Data on the characteristics and the kinetic and mechanistic features of the catalytic reaction, as well as

M. Bregolato; V. Bolis; C. Busco; P. Ugliengo; S. Bordiga; F. Cavani; N. Ballarini; L. Maselli; S. Passeri; I. Rossetti; L. Forni

2007-01-01

258

Phytolacca americana inhibits the high glucose-induced mesangial proliferation via suppressing extracellular matrix accumulation and TGF-beta production.  

PubMed

This study describes a potential of Phytolaccaceae (Phytolacca americana var.) as an inhibitor of high glucose-stimulated production of extracellular matrix (ECM) proteins and TGF-beta in cultured glomerular mesangial cells (GMCs). Raising the ambient glucose concentration for 24 hrs caused a dose-dependent increase in [3H]thymidine incorporation of GMCs, and the maximal response was achieved at 20 mM. Phytolaccaceae extracts (2.5-20 microg/ml) inhibited the high glucose-induced [3H]thymidine incorporation in a dose-dependent manner, and the concentrations tested here did not affect to the cell viability. Exposure of the GMCs to 20 mM glucose caused both ECM (collagen and fibronectin) accumulation and TGF-beta secretion, and these changes were significantly diminished by treatment of GMCs with Phytolaccaceae (10 microg/ml). Taken together, these results indicate that Phytolaccaceae inhibits the high glucose-induced GMCs proliferation partially through suppressing accumulation of ECM components and TGF-beta production, suggesting that Phytolaccaceae may be a promising agent for treating the development and progression of diabetic glomerulopathy. PMID:15070169

Jeong, Seung Il; Kim, Kang Ju; Choo, Yong Kug; Keum, Kyung Soo; Choi, Bong Kyu; Jung, Kyu Yong

2004-02-01

259

Enhanced thermotolerance and ethanol tolerance in Saccharomyces cerevisiae mutated by high-energy pulse electron beam and protoplast fusion.  

PubMed

To increase thermotolerance and ethanol tolerance in Saccharomyces cerevisiae strain YZ1, the strategies of high-energy pulse electron beam (HEPE) and three rounds of protoplast fusion were explored. The YF31 strain had the characteristics of resistant to high-temperature, high-ethanol tolerance, rapid growth and high yield. The YF31 could grow on plate cultures up to 47 °C, containing 237.5 g L(-1) of ethanol. In particular, the mutant strain YF31 generated 94.2 ± 4.8 g L(-1) ethanol from 200 g glucose L(-1) at 42 °C, which was 2.48 times the production of the wild strain YZ1. Results demonstrated that the variant phenotypes from the strains screening by HEPE irradiation could be used as parent stock for yeast regeneration and the protoplast fusion technology is sufficiently powerful in combining suitable characteristics in a single strain for ethanol fermentation. PMID:22488242

Zhang, Min; Xiao, Yu; Zhu, Rongrong; Zhang, Qin; Wang, Shi-Long

2012-11-01

260

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

SciTech Connect

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

Ince-Cushman, A.; Rice, J. E.; Reinke, M. L.; Podpaly, Y.; Marmar, E. S. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Bitter, M.; Hill, K. W.; Scott, S. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Gu, M. F. [Lawrence Livermore National Laboratory, California 94550 (United States); Eikenberry, E.; Broennimann, Ch. [DECTRIS Ltd., Villigen-PSI 5232 (Switzerland); Lee, S. G. [National Fusion Research Institute, Yusung, Taejeon 305-333 (Korea, Republic of)

2008-10-15

261

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

PubMed

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

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

2008-10-01

262

Reduction of high-affinity beta2-adrenergic receptor binding by hyperforin and hyperoside on rat C6 glioblastoma cells measured by fluorescence correlation spectroscopy.  

PubMed

Beta-adrenergic receptors (beta-AR) are potential targets for antidepressants. Desensitization and downregulation of beta-AR are discussed as possible modes of action for antidepressants. We have investigated the effects of hyperforin and hyperoside, compounds with potentially antidepressant activity from St. John's Wort, on the binding behavior and dynamics of beta2-AR in living rat C6 glioblastoma cells, compared to desipramine (desmethylimipramine; DMI) by means of fluorescence correlation spectroscopy (FCS) and fluorescence microscopy. FCS-binding studies with the fluorescently labeled ligand Alexa532-noradrenaline (Alexa532-NA) binding to beta2-AR of C6 cells showed a significant reduction in total beta2-AR binding after preincubation with hyperforin and hyperoside for 3 days, respectively, which was also found for DMI. This was mainly observed in high-affinity receptor-ligand complexes with hindered lateral mobility (D2 = 1.1 (+/-0.4) microm2/s) in the biomembrane. However, internalization of beta2-AR was found neither in z-scans of these C6 cells nor in HEK 293 cells stably transfected with GFP-tagged beta2-adrenergic receptors (beta2AR-GFP) after incubation up to 6 days with either DMI, hyperforin, or hyperoside. Thus, under these conditions reduction of beta2-AR binding was not mediated by receptor internalization. Additionally, preincubation of C6 cells with DMI, hyperforin, and hyperoside led to a loss of second messenger cAMP after beta2-adrenergic stimulating conditions with terbutaline. Our current results indicate that hyperforin and hyperoside from St. John's Wort, as well as DMI, reduce beta2-adrenergic sensitivity in C6 cells, emphasizing the potential usefulness of St. John's Wort dry extracts in clinical treatment of depressive symptoms. PMID:17417877

Prenner, Lars; Sieben, Anne; Zeller, Karin; Weiser, Dieter; Häberlein, Hanns

2007-05-01

263

Gyrokinetic turbulence simulations of high-beta tokamak and helical plasmas with full-kinetic and hybrid models  

NASA Astrophysics Data System (ADS)

Turbulent transport in high-beta toroidal plasmas is investigated by means of an electromagnetic gyrokinetic model and a newly developed electromagnetic hybrid model consisting of the gyrokinetic equation for ions and drift-Landau-fluid equations for electrons. Full gyrokinetic simulation results for Cyclone base case tokamak and for Large Helical Device (LHD) plasmas are quickly and accurately reproduced by the hybrid simulation. In the kinetic ballooning mode (KBM)-driven turbulence the ion heat and particle fluxes are mainly caused by electrostatic perturbation, and the contribution of magnetic perturbation is small and negative. The electron heat flux is caused by both electrostatic and magnetic perturbations. The numerical solutions satisfy the entropy balance equation, and the entropy is transferred from ions to electrons through electrostatic and magnetic perturbations. An analysis based on the entropy balance equation shows that the zonal structure is produced by magnetic nonlinearity corresponding to the Maxwell stress in the fluid limit but is weakened by the electrostatic one related to the Reynolds stress. A linear analysis on the standard configuration of LHD plasmas shows the suppression of the ion temperature gradient mode by finite-beta effects and the destabilization of KBM at high beta.

Ishizawa, A.; Maeyama, S.; Watanabe, T.-H.; Sugama, H.; Nakajima, N.

2013-05-01

264

Identification of the stimulated-emission threshold in high-{beta} nanoscale lasers through phase-space reconstruction  

SciTech Connect

Nanoscale lasers sustain a few optical modes so that the fraction of spontaneous emission {beta} funnelled into the useful (lasing) mode is high (of the order of 10{sup -1}) and the threshold, which traditionally corresponds to an abrupt kink in the light-in-light-out curve, becomes ill defined. We propose an alternative definition of the threshold that is based on the dynamical response of the laser and is valid even for {beta}=1 lasers. The laser dynamics is analyzed through a reconstruction of its phase-space trajectory for pulsed excitations. Crossing the threshold, brings about a change in the shape of the trajectory and in the area contained in it. An unambiguous determination of the threshold in terms of this change is shown theoretically and illustrated experimentally in a photonic-crystal laser.

Hachair, X.; Elvira, D.; Le Gratiet, L.; Lemaitre, A.; Abram, I.; Sagnes, I.; Robert-Philip, I.; Beveratos, A. [Laboratoire de Photonique et de Nanostructures, CNRS-UPR20, Route de Nozay, 91460 Marcoussis (France); Braive, R. [Laboratoire de Photonique et de Nanostructures, CNRS-UPR20, Route de Nozay, 91460 Marcoussis (France); Universite Paris Denis Diderot, 75205 Paris, Cedex 13 (France); Lippi, G. L. [Institut Non Lineaire de Nice, Universite de Nice-Sophia Antipolis, 1361 Route des Lucioles, F-06560 Valbonne (France); Institut Non Lineaire de Nice, CNRS UMR 6618, 1361 Route des Lucioles, F-06560 Valbonne (France)

2011-05-15

265

Fusion-Fission Hybrids Driven By Heavy Ion Inertial Fusion  

Microsoft Academic Search

There is a desire to resolve fuel cycle issues for increasing the role of nuclear energy. The recent Laser Inertial Fusion-Fission Energy (LIFE) initiative that builds upon NIF ignition, is likely to rekindle national interest in developing intense, high power ion beam accelerators for fusion energy production and for fusion-fission hybrid concepts that combine an ion beam driven fusion neutron

P. A. Seidl

266

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

267

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

268

Production of high purity TeO2 single crystals for the study of neutrinoless double beta decay  

E-print Network

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 for TeO2 crystals production are reported. Production and certification protocols are presented and resulting ready-to-use TeO2 crystals are described.

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

2010-05-20

269

Construction of hormonally responsive intact cell hybrids by cell fusion: transfer of. beta. -adrenergic receptor and nucleotide regulatory protein(s) in normal and desensitized cells  

SciTech Connect

Fusion of normal, untreated human erythrocytes with desensitized turkey erythrocytes increases isoproterenol stimulation of cyclic (/sup 3/H)AMP accumulation over basal rates. Moreover, pretreatment of the human erythrocytes with cholera toxin before they are fused with desensitized turkey erthythrocytes leads to a large stimulation with isoproterenol. This is even greater and far more rapid than the response obtained if turkey erythrocytes are treated directly with cholera toxin. It is concluded that the stimulation in the fused system is due to the transfer of an ADP-ribosylated subunit of nucleotide regulatory protein.

Schulster, D.; Salmon, D.M.

1985-01-01

270

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

271

Recent advances in high current vacuum arc ion sources for heavy ion fusion  

NASA Astrophysics Data System (ADS)

For a heavy ion fusion induction linac driver, a source of heavy ions with charge states 1+-3+, ?0.5 A current beams, ?20 ?s pulse widths and ˜10 Hz repetition rates is required. Thermionic sources have been the workhorse for the Heavy Ion Fusion (HIF) program to date, but suffer from heating problems for large areas and contamination. They are limited to low (contact) ionization potential elements and offer relatively low ion fluxes with a charge state limited to 1+. Gas injection sources suffer from partial ionization and deleterious neutral gas effects. The above shortcomings of the thermionic ion sources can be overcome by a vacuum arc ion source. The vacuum arc ion source is a good candidate for HIF applications. It is capable of providing ions of various elements and different charge states in short and long pulse bursts and high beam current density. Under a Phase-I STTR from DOE, the feasibility of the vacuum arc ion source for the HIF applications was investigated. We have modified an existing vacuum arc ion source at LBNL to produce a gadolinium ( A?158) ion beam with >0.5 A beam current, 120 keV beam energy, ?6 cm diameter extraction aperture and ?20 ?s pulse width. The average beam current density at the extraction grids was ?17 mA/cm 2. We have measured that >85% Gd ions were in the 3+ charge state, the beam current fluctuation level (rms) was ?3%, pulse-to-pulse variation of the beam (rms) was about 3%, the uniformity of the beam density over its 6 cm diameter was ?98% and the ion longitudinal energy spread was ?1%. Additional measurements were made to improve charge state purity by using other materials and employing an axial magnetic field close to the cathode. Yttrium ( A?89), lead ( A?207), and Ba ( A?137) were tested at similar current parameters with Ba delivering nearly a pure charge state with >95% being in 2+ state. The results of the experiments indicate that the vacuum arc ion source is a good candidate for HIF applications.

Qi, Niansheng; Schein, Jochen; Prasad, Rahul R.; Krishnan, Mahadevan; Anders, Andre; Kwan, Joe; Brown, Ian

2001-05-01

272

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

273

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. PMID:18716331

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

2008-01-01

274

A high efficiency, low background neutron and gamma detector for cold fusion experiments  

NASA Astrophysics Data System (ADS)

The present apparatus (named by the acrostic "FERMI" also to celebrate the 60 yr of the discovery, by Enrico Fermi and collaborators at Rome University, of the effects of moderation of neutrons) is mainly a moderated neutron detector developed for the search of cold fusion events. It is based on 7 BF 3 and 2 3He proportional counters with detection efficiency for neutrons 40%-8% in the range 1 keV-20 MeV, pulse shape acquisition and good time resolution for neutron bursts; it also allows us to perform a good reconstruction of the average original neutron energy. The neutron background measured in the Gran Sasso INFN underground laboratory is about 0.09 Hz. Gamma rays are revealed mostly by a complementary low background NaI detector with 26% solid angle coverage. The performances are controlled by a full MC simulation, experimentally tested. A high multiplicity (up to ˜ 100) neutrons' event has been detected during background runs. The system is being upgraded by the detection and identification of charged hadrons.

Stella, B.; Celani, F.; Corradi, M.; Ferrarotto, F.; Iucci, N.; Milone, V.; Spallone, A.; Villoresi, G.

1995-02-01

275

Pulsed-power-driven high energy density physics and inertial confinement fusion researcha)  

NASA Astrophysics Data System (ADS)

The Z accelerator [R. B. Spielman, W. A. Stygar, J. F. Seamen et al., Proceedings of the 11th International Pulsed Power Conference, Baltimore, MD, 1997, edited by G. Cooperstein and I. Vitkovitsky (IEEE, Piscataway, NJ, 1997), Vol. 1, p. 709] at Sandia National Laboratories delivers ˜20MA load currents to create high magnetic fields (>1000T) and high pressures (megabar to gigabar). In a z-pinch configuration, the magnetic pressure (the Lorentz force) supersonically implodes a plasma created from a cylindrical wire array, which at stagnation typically generates a plasma with energy densities of about 10MJ/cm3 and temperatures >1keV at 0.1% of solid density. These plasmas produce x-ray energies approaching 2MJ at powers >200TW for inertial confinement fusion (ICF) and high energy density physics (HEDP) experiments. In an alternative configuration, the large magnetic pressure directly drives isentropic compression experiments to pressures >3Mbar and accelerates flyer plates to >30km/s for equation of state (EOS) experiments at pressures up to 10Mbar in aluminum. Development of multidimensional radiation-magnetohydrodynamic codes, coupled with more accurate material models (e.g., quantum molecular dynamics calculations with density functional theory), has produced synergy between validating the simulations and guiding the experiments. Z is now routinely used to drive ICF capsule implosions (focusing on implosion symmetry and neutron production) and to perform HEDP experiments (including radiation-driven hydrodynamic jets, EOS, phase transitions, strength of materials, and detailed behavior of z-pinch wire-array initiation and implosion). This research is performed in collaboration with many other groups from around the world. A five year project to enhance the capability and precision of Z, to be completed in 2007, will result in x-ray energies of nearly 3MJ at x-ray powers >300TW.

Matzen, M. Keith; Sweeney, M. A.; Adams, R. G.; Asay, J. R.; Bailey, J. E.; Bennett, G. R.; Bliss, D. E.; Bloomquist, D. D.; Brunner, T. A.; Campbell, R. B.; Chandler, G. A.; Coverdale, C. A.; Cuneo, M. E.; Davis, J.-P.; Deeney, C.; Desjarlais, M. P.; Donovan, G. L.; Garasi, C. J.; Haill, T. A.; Hall, C. A.; Hanson, D. L.; Hurst, M. J.; Jones, B.; Knudson, M. D.; Leeper, R. J.; Lemke, R. W.; Mazarakis, M. G.; McDaniel, D. H.; Mehlhorn, T. A.; Nash, T. J.; Olson, C. L.; Porter, J. L.; Rambo, P. K.; Rosenthal, S. E.; Rochau, G. A.; Ruggles, L. E.; Ruiz, C. L.; Sanford, T. W. L.; Seamen, J. F.; Sinars, D. B.; Slutz, S. A.; Smith, I. C.; Struve, K. W.; Stygar, W. A.; Vesey, R. A.; Weinbrecht, E. A.; Wenger, D. F.; Yu, E. P.

2005-05-01

276

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

SciTech Connect

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

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

2012-12-20

277

Pressure-driven sound turbulence in a high-beta plasma  

NASA Technical Reports Server (NTRS)

LF turbulence is investigated experimentally in a 2-m-long 1-m-diameter magnetized electron fluid with beta(e) = about 0.5 and unmagnetized ions, generated in a double-pulsed linear dc discharge under a uniform external magnetic field of 15 G. The results of measurements with Langmuir probes, electric probes, and a directional particle analyzer are presented in graphs and characterized in detail. It is shown that the strong cross-field sound turbulence observed near the lower hybrid frequency is caused by the electron pressure gradient rather than E x B drift, with (1) temperature-gradient wave refraction as the dominant saturation mechanism, (2) wave-enhanced ion mass flow, and (3) only negligible ion-tail formation. The relevance of the present findings for studies of magnetic shock propagation is indicated.

Stenzel, R. L.

1990-01-01

278

Calibration and test measurements of a high purety germanium beta spectrometer  

NASA Astrophysics Data System (ADS)

Calibration measurements of an on-line beta spectrometer are described. Distortions of the measured spectra, caused by the detection step, are discussed. A correction of the beta spectrum for coincidental gamma rays was introduced and put into the fitting program BCONT. Using a Co56 source, a performance test of the correction was carried out. The fitted Q-value (4566.54 (1.92) keV) agrees with the literature value. On-line measurements of the spectra of Au186 were carried out. Data analysis gives a Q-value of 4830 keV, over 1200 keV lower than the calculated Q-value in the literature.

Coops, P.

1983-11-01

279

Virtual Screening against Highly Charged Active Sites:  Identifying Substrates of Alpha?Beta Barrel Enzymes †  

Microsoft Academic Search

We have developed a virtual ligand screening method designed to help assign enzymatic function for alpha-beta barrel proteins. We dock a library of 19,000 known metabolites against the active site and attempt to identify the relevant substrate based on predicted relative binding free energies. These energies are computed using a physics-based energy function based on an all-atom force field (OPLS-

Chakrapani Kalyanaraman; Katarzyna Bernacki; Matthew P. Jacobson

2005-01-01

280

A PARALLEL-PROPAGATING ALFVENIC ION-BEAM INSTABILITY IN THE HIGH-BETA SOLAR WIND  

SciTech Connect

We investigate the conditions under which parallel-propagating Alfven/ion-cyclotron waves are driven unstable by an isotropic (T{sub {alpha}} = T{sub Parallel-To {alpha}}) population of alpha particles drifting parallel to the magnetic field at an average speed U{sub {alpha}} with respect to the protons. We derive an approximate analytic condition for the minimum value of U{sub {alpha}} needed to excite this instability and refine this result using numerical solutions to the hot-plasma dispersion relation. When the alpha-particle number density is {approx_equal} 5% of the proton number density and the two species have similar thermal speeds, the instability requires that {beta}{sub p} {approx}> 1, where {beta}{sub p} is the ratio of the proton pressure to the magnetic pressure. For 1 {approx}< {beta}{sub p} {approx}< 12, the minimum U{sub {alpha}} needed to excite this instability ranges from 0.7v{sub A} to 0.9v{sub A}, where v{sub A} is the Alfven speed. This threshold is smaller than the threshold of {approx_equal} 1.2v{sub A} for the parallel magnetosonic instability, which was previously thought to have the lowest threshold of the alpha-particle beam instabilities at {beta}{sub p} {approx}> 0.5. We discuss the role of the parallel Alfvenic drift instability for the evolution of the alpha-particle drift speed in the solar wind. We also analyze measurements from the Wind spacecraft's Faraday cups and show that the U{sub {alpha}} values measured in solar-wind streams with T{sub {alpha}} Almost-Equal-To T{sub Parallel-To {alpha}} are approximately bounded from above by the threshold of the parallel Alfvenic instability.

Verscharen, Daniel; Bourouaine, Sofiane; Chandran, Benjamin D. G. [Space Science Center, University of New Hampshire, Durham, NH 03824 (United States); Maruca, Bennett A., E-mail: daniel.verscharen@unh.edu, E-mail: s.bourouaine@unh.edu, E-mail: benjamin.chandran@unh.edu, E-mail: bmaruca@ssl.berkeley.edu [Space Science Laboratory, University of California, Berkeley, CA 94720 (United States)

2013-08-10

281

Waste minimization through high-pressure microwave digestion of soils for gross {alpha}/{beta} analyses  

SciTech Connect

As a result of the U.S. Department of Energy`s (DOE) environmental restoration and waste management activities, laboratories receive numerous analytical requests for gross {alpha}/{beta} analyses. Traditional sample preparation methods for gross {alpha}/{beta} analysis of environmental and mixed waste samples require repetitive leaching, which is time consuming and generates large volumes of secondary wastes. An alternative to leaching is microwave digestion. In the past. microwave technology has had limited application in the radiochemical laboratory because of restrictions on sample size resulting from vessel pressure limitations. However, new microwave vessel designs allow for pressures on the order of 11 MPa (1500 psi). A procedure is described in which microwave digestion is used to prepare environmental soil samples for gross {alpha}/{beta} analysis. Results indicate that the described procedure meets performance requirements for several soil types and is equivalent to traditional digestion techniques. No statistical differences at the 95% confidence interval exist between the measurement on samples prepared from the hot plate and microwave digestion procedures for those soils tested. Moreover, microwave digestion allows samples to be prepared in a fraction of the time with significantly less acid and with lower potential of cross-contamination. In comparison to the traditional hot plate method, the waste volumes required for the microwave procedure are a factor of 10 lower, while the analyst time for sample processing is at least a factor of three lower.

Yaeger, J.S.; Smith, L.L.

1995-04-01

282

11 beta-hydroxysteroid dehydrogenase type 1 induction in the arcuate nucleus by high-fat feeding: A novel constraint to hyperphagia?  

PubMed

11 beta-Hydroxysteroid dehydrogenase type 1 (11 beta-HSD1) catalyzes regeneration of active intracellular glucocorticoids in fat, liver, and discrete brain regions. Although overexpression of 11 beta-HSD1 in adipose tissue causes hyperphagia and the metabolic syndrome, male 11 beta-HSD1 null (11 beta-HSD1-/-) mice resist metabolic disease on high-fat (HF) diet, but also show hyperphagia. This suggests 11 beta-HSD1 may influence the central actions of glucocorticoids on appetite and perhaps energy balance. We show that 11 beta-HSD1-/- mice express lower hypothalamic mRNA levels of the anorexigenic cocaine and amphetamine-regulated transcript and melanocortin-4 receptor, but higher levels of the orexigenic melanin-concentrating hormone mRNAs than controls (C57BL/6J) on a low-fat diet (11% fat). HF (58% fat) diet promoted transient ( approximately 8 wk) hyperphagia and decreased food efficiency in 11 beta-HSD1-/- mice and decreased melanocortin-4 receptor mRNA expression in control but not 11 beta-HSD1-/- mice. 11 beta-HSD1-/- mice showed a HF-mediated up-regulation of the orexigenic agouti-related peptide (AGRP) mRNA in the arcuate nucleus which paralleled the transient HF hyperphagia. Conversely, control mice showed a rapid (48 h) HF-mediated increase in arcuate 11 beta-HSD1 associated with subsequent down-regulation of AGRP. This regulatory pattern was unexpected because glucocorticoids increase AGRP, suggesting an alternate hyperphagic mechanism despite partial colocalization of 11 beta-HSD1 and AGRP in arcuate nucleus cells. One major alternate mechanism governing selective fat ingestion and the AGRP system is endogenous opioids. Treatment of HF-fed mice with the mu opioid agonist DAMGO recapitulated the HF-induced dissociation of arcuate AGRP expression between control and 11 beta-HSD1-/- mice, whereas the opioid antagonist naloxone given with HF induced a rise in arcuate AGRP and blocked HF-diet induction of 11 beta-HSD1. These data suggest that 11 beta-HSD1 in brain plays a role in the adaptive restraint of excess fat intake, in part by increasing inhibitory opioid tone on AGRP expression in the arcuate nucleus. PMID:16763061

Densmore, Valerie S; Morton, Nicholas M; Mullins, John J; Seckl, Jonathan R

2006-09-01

283

[Determination of fifteen beta-agonists in animal urine by high performance liquid chromatography-tandem mass spectrometry].  

PubMed

A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/ MS) method was established for the determination of fifteen beta-agonists (clenbuterol, ractopamine, salbutamol, cimaterol, mabuterol, tulobuterol, bambuterol, mapenterol, cimbuterol, zilpaterol, formoterol, clorprenaline, terbutaline, penbutolol and brombuterol) in animal urine. Perchloric acid solution was used to acidify the sample and precipitate protein in the sample. The sample was purified and concentrated by an HLB mini-column. The separation of the beta-agonist was performed on an Agilent 1100 HPLC system with a Eclipse XDB-C18 column by using gradient elution with methanol and water (containing 0.1% (v/v) formic acid) as the mobile phases at a flow rate of 1 mL/min. Qualitative and quantitative analysis of the fifteen beta-agonists, which were ionized by electrospray ionization interface (ESI), were carried out in multiple reaction monitoring (MRM) mode with API 4000 tandem mass spectrometry. The calibration curves showed good linearity in the mass concentration range of 0.25 - 20 microg/L with the correlation coefficients r > or = 0.999 5. The recoveries of the fifteen beta-agonists ranged from 62.1% to 107% at the spiked levels of 0.25, 1.0 and 10 microg/L. The relative standard deviations (n = 10) were between 3.5% and 9.9%. The limits of quantification (S/N > 10) were 0.25 microg/L for all the analytes. This method is simple, rapid, sensitive and accurate. PMID:21261043

Nie, Jianrong; Zhu, Mingli; Lian, Jin; Pan, Yunshan; Deng, Xianglian; Hu, Cuiping

2010-08-01

284

High efficiency and fast USXR and SXR scintillators for MHD and turbulence diagnostics of Magnetically Confined Fusion Experiments  

Microsoft Academic Search

We are developing MHD and turbulence diagnostics which will image rapid fluctuations (on the scale of tens of kHz) of relatively weak fluctuations of soft and ultrasoft X-ray emission from Magnetically Confined Fusion plasmas. Paramount to these systems is finding soft X-ray to visible light converters having less than a few µs decay time and high conversion efficiencies. We performed

R. Vero; D. Stutman; B. Blagojevic; M. Finkenthal; H. W. Moos; V. Soukhanovskii; M. J. May

2001-01-01

285

Mitigation of rotational instability of high-beta field-reversed configuration by double-sided magnetized plasmoid injection  

SciTech Connect

Active control of destructive rotational instability in a high-beta field-reversed configuration (FRC) plasma was demonstrated by using double-sided plasmoid injection technique. The elliptical deformation of the FRC's cross section was mitigated as a result of substantial suppression of spontaneous spin-up by the plasmoid injection. It was found that the injected plasmoid provided better stability against the rotational mode, suggesting that the compensation of the FRC's decaying magnetic flux might help to suppress its spin-up.

Itagaki, H.; Inomoto, M. [Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan)] [Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan); Asai, T.; Takahashi, Ts. [College of Science and Technology, Nihon University, 1-8-14 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan)] [College of Science and Technology, Nihon University, 1-8-14 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan)

2014-03-15

286

The national spherical torus experiment (NSTX) research programme and progress towards high beta, long pulse operating scenarios  

NASA Astrophysics Data System (ADS)

A major research goal of the national spherical torus experiment is establishing long-pulse, high beta, high confinement operation and its physics basis. This research has been enabled by facility capabilities developed during 2001 and 2002, including neutral beam (up to 7 MW) and high harmonic fast wave (HHFW) heating (up to 6 MW), toroidal fields up to 6 kG, plasma currents up to 1.5 MA, flexible shape control, and wall preparation techniques. These capabilities have enabled the generation of plasmas with \\beta _T \\equiv \\langle p \\rangle /(B_{T0}^{2}/2\\mu_{0}) of up to 35%. Normalized beta values often exceed the no-wall limit, and studies suggest that passive wall mode stabilization enables this for H mode plasmas with broad pressure profiles. The viability of long, high bootstrap current fraction operations has been established for ELMing H mode plasmas with toroidal beta values in excess of 15% and sustained for several current relaxation times. Improvements in wall conditioning and fuelling are likely contributing to a reduction in H mode power thresholds. Electron thermal conduction is the dominant thermal loss channel in auxiliary heated plasmas examined thus far. HHFW effectively heats electrons, and its acceleration of fast beam ions has been observed. Evidence for HHFW current drive is obtained by comparision of the loop voltage evolution in plasmas with matched density and temperature profiles but varying phases of launched HHFW waves. Studies of emissions from electron Bernstein waves indicate a density scale length dependence of their transmission across the upper hybrid resonance near the plasma edge that is consistent with theoretical predictions. A peak heat flux to the divertor targets of 10 MW m-2 has been measured in the H mode, with large asymmetries being observed in the power deposition between the inner and outer strike points. Non-inductive plasma startup studies have focused on coaxial helicity injection. With this technique, toroidal currents up to 400 kA have been driven, and studies to assess flux closure and coupling to other current drive techniques have begun.

Synakowski, E. J.; Bell, M. G.; Bell, R. E.; Bigelow, T.; Bitter, M.; Blanchard, W.; Boedo, J.; Bourdelle, C.; Bush, C.; Darrow, D. S.; Efthimion, P. C.; Fredrickson, E. D.; Gates, D. A.; Gilmore, M.; Grisham, L. R.; Hosea, J. C.; Johnson, D. W.; Kaita, R.; Kaye, S. M.; Kubota, S.; Kugel, H. W.; LeBlanc, B. P.; Lee, K.; Maingi, R.; Manickam, J.; Maqueda, R.; Mazzucato, E.; Medley, S. S.; Menard, J.; Mueller, D.; Nelson, B. A.; Neumeyer, C.; Ono, M.; Paoletti, F.; Park, H. K.; Paul, S. F.; Peng, Y.-K. M.; Phillips, C. K.; Ramakrishnan, S.; Raman, R.; Roquemore, A. L.; Rosenberg, A.; Ryan, P. M.; Sabbagh, S. A.; Skinner, C. H.; Soukhanovskii, V.; Stevenson, T.; Stutman, D.; Swain, D. W.; Taylor, G.; Von Halle, A.; Wilgen, J.; Williams, M.; Wilson, J. R.; Zweben, S. J.; Akers, R.; Barry, R. E.; Beiersdorfer, P.; Bialek, J. M.; Blagojevic, B.; Bonoli, P. T.; Budny, R.; Carter, M. D.; Chang, C. S.; Chrzanowski, J.; Davis, W.; Deng, B.; Doyle, E. J.; Dudek, L.; Egedal, J.; Ellis, R.; Ferron, J. R.; Finkenthal, M.; Foley, J.; Fredd, E.; Glasser, A.; Gibney, T.; Goldston, R. J.; Harvey, R.; Hatcher, R. E.; Hawryluk, R. J.; Heidbrink, W.; Hill, K. W.; Houlberg, W.; Jarboe, T. R.; Jardin, S. C.; Ji, H.; Kalish, M.; Lawrance, J.; Lao, L. L.; Lee, K. C.; Levinton, F. M.; Luhmann, N. C.; Majeski, R.; Marsala, R.; Mastravito, D.; Mau, T. K.; McCormack, B.; Menon, M. M.; Mitarai, O.; Nagata, M.; Nishino, N.; Okabayashi, M.; Oliaro, G.; Pacella, D.; Parsells, R.; Peebles, T.; Peneflor, B.; Piglowski, D.; Pinsker, R.; Porter, G. D.; Ram, A. K.; Redi, M.; Rensink, M.; Rewoldt, G.; Robinson, J.; Roney, P.; Schaffer, M.; Shaing, K.; Shiraiwa, S.; Sichta, P.; Stotler, D.; Stratton, B. C.; Takase, Y.; Tang, X.; Vero, R.; Wampler, W. R.; Wurden, G. A.; Xu, X. Q.; Yang, J. G.; Zeng, L.; Zhu, W.

2003-12-01

287

The National Spherical Torus Experiment (NSTX) research programme and progress towards high beta, long pulse operating scenarios.  

SciTech Connect

A major research goal of the national spherical torus experiment is establishing long-pulse, high beta, high confinement operation and its physics basis. This research has been enabled by facility capabilities developed during 2001 and 2002, including neutral beam (up to 7 MW) and high harmonic fast wave (HHFW) heating (up to 6 MW), toroidal fields up to 6 kG, plasma currents up to 1.5 MA, flexible shape control, and wall preparation techniques. These capabilities have enabled the generation of plasmas with {beta}{sub T} {triple_bond}

/(B{sub T0}{sup 2}/2{mu}{sub 0}) of up to 35%. Normalized beta values often exceed the no-wall limit, and studies suggest that passive wall mode stabilization enables this for H mode plasmas with broad pressure profiles. The viability of long, high bootstrap current fraction operations has been established for ELMing H mode plasmas with toroidal beta values in excess of 15% and sustained for several current relaxation times. Improvements in wall conditioning and fueling are likely contributing to a reduction in H mode power thresholds. Electron thermal conduction is the dominant thermal loss channel in auxiliary heated plasmas examined thus far. HHFW effectively heats electrons, and its acceleration of fast beam ions has been observed. Evidence for HHFW current drive is obtained by comparison of the loop voltage evolution in plasmas with matched density and temperature profiles but varying phases of launched HHFW waves. Studies of emissions from electron Bernstein waves indicate a density scale length dependence of their transmission across the upper hybrid resonance near the plasma edge that is consistent with theoretical predictions. A peak heat flux to the divertor targets of 10 MW m{sup -2} has been measured in the H mode, with large asymmetries being observed in the power deposition between the inner and outer strike points. Non-inductive plasma startup studies have focused on coaxial helicity injection. With this technique, toroidal currents up to 400 kA have been driven, and studies to assess flux closure and coupling to other current drive techniques have begun.

Johnson, D.W. (Princeton University, Princeton, NJ); Grisham, L.R. (Princeton University, Princeton, NJ); Zweben, S. J. (Princeton University, Princeton, NJ); Gates, D.A. (Princeton University, Princeton, NJ); Bush, C. (Oak Ridge National Laboratory, Oak Ridge, TN); Synakowski, E.J. (Princeton University, Princeton, NJ); Hosea, J. C. (Princeton University, Princeton, NJ); Blanchard, W. (Princeton University, Princeton, NJ); Bell, Michael G. (Princeton University, Princeton, NJ); Sabbagh, S. (Columbia University, New York, NY); Soukhanovskii, V. (Princeton University, Princeton, NJ); Raman, R. (University of Washington, Seattle, WA,); Peng, Y-K. M. (Oak Ridge National Laboratory, Oak Ridge, TN); Ono, M. (Princeton University, Princeton, NJ); Stevenson, T. (Princeton University, Princeton, NJ); Fredrickson, E. D. (Princeton University, Princeton, NJ); Kubota, Shigeru (University of California, Los Angeles, CA); Efthimion, P. C. (Princeton University, Princeton, NJ); Bourdelle, C. (CEA Cadarache, France); Wilson, J.R. (Princeton University, Princeton, NJ); Maqueda, R. (Los Alamos National Laboratory, Los Alamos, NM); Kaye, S. M. (Princeton University, Princeton, NJ); Kaita, R. (Princeton University, Princeton, NJ); Maingi, R. (Oak Ridge National Laboratory, Oak Ridge, TN); Darrow, D. S. (Princeton University, Princeton, NJ); Bitter, M. (Princeton University, Princeton, NJ); Kugel, Henry W. (Princeton University, Princeton, NJ); Skinner, C. H. (Princeton University, Princeton, NJ); Wilgen, J. (Oak Ridge National Laboratory, Oak Ridge, TN); Von Halle, A. (Princeton University, Princeton, NJ); Taylor, G. (Princeton University, Princeton, NJ); Mueller, D. (Princeton University, Princeton, NJ); Swain, D. W. (Oak Ridge National Laboratory, Oak Ridge, TN); Ryan, P.M. (Oak Ridge National Laboratory, Oak Ridge, TN); Rosenberg, A. (Princeton University, Princeton, NJ); Ramakrishnan, S. (Princeton University, Princeton, NJ); Phillips, C.K. (Princeton University, Princeton, NJ); Paul, S. (Princeton University, Princeton, NJ); Park, H.K. (Princeton University, Princeton, NJ); Paoletti, F. (Columbia University, New York, NY); Boedo, J. (University of California, San Diego, CA); Williams, M. (Princeton University, Princeton, NJ); Gilmore, Mark A. (University of New Mexico, Albuquerque, NM); LeBlanc, B. (Princeton University, Princeton, NJ); Bigelow, T. (Oak Ridge National Laboratory, Oak Ridge, TN); Bell, R. E. (Princeton University, Princeton, NJ); Roquemore, A. L. (Princeton University, Princeton, NJ); Wampler, William R.; Medley, S. S. (Princeton University, Princeton, NJ); Stutman, D. (Johns Hopkins University, Baltimore, MD); Menard, J. (Princeton University, Princeton, NJ); Mazzucato, E. (Princeton University, Princeton, NJ); Neumeyer, C. (Princeton University, Princeton, NJ); Nelson, B.A. (University of Washington, Seattle, WA); Lee, K. (University of California, Davis, CA); Manickam, J. (Princeton University, Princeton, NJ)

2004-06-01

288

Highly Potent, Water Soluble Benzimidazole Antagonist for Activated (alpha)4(beta)1 Integrin  

SciTech Connect

The cell surface receptor {alpha}{sub 4}{beta}{sub 1} integrin, activated constitutively in lymphoma, can be targeted with the bisaryl urea peptidomimetic antagonist 1 (LLP2A). However, concerns on its preliminary pharmacokinetic (PK) profile provided an impetus to change the pharmacophore from a bisaryl urea to a 2-arylaminobenzimidazole moiety resulting in improved solubility while maintaining picomolar potency [5 (KLCA4); IC{sub 50} = 305 pM]. With exceptional solubility, this finding has potential for improving PK to help diagnose and treat lymphomas.

Carpenter, R D; Andrei, M; Lau, E Y; Lightstone, F C; Liu, R; Lam, K S; Kurth, M J

2007-08-29

289

Highly stable beta-class carbonic anhydrases useful in carbon capture systems  

DOEpatents

The present disclosure relates to .beta.-class carbonic anhydrase polypeptides having improved properties including increased thermostability and/or stability in the presence of amine compounds, ammonia, or carbonate ion. The present disclosure also provides formulations and uses of the polypeptides for accelerating the absorption of carbon dioxide from a gas stream into a solution as well as for the release of the absorbed carbon dioxide for further treatment and/or sequestering. Also provided are polynucleotides encoding the carbonic anhydrase polypeptides and host cells capable of expressing them.

Alvizo, Oscar; Benoit, Mike; Novick, Scott

2013-04-16

290

Highly stable beta-class carbonic anhydrases useful in carbon capture systems  

DOEpatents

The present disclosure relates to .beta.-class carbonic anhydrase polypeptides having improved properties including increased thermostability and/or stability in the presence of amine compounds, ammonia, or carbonate ion. The present disclosure also provides formulations and uses of the polypeptides for accelerating the absorption of carbon dioxide from a gas stream into a solution as well as for the release of the absorbed carbon dioxide for further treatment and/or sequestering. Also provided are polynucleotides encoding the carbonic anhydrase polypeptides and host cells capable of expressing them.

Alvizo, Oscar; Benoit, Michael R; Novick, Scott J

2013-08-20

291

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

NASA Astrophysics Data System (ADS)

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 can approach 100,000 MW/m2 for 0.1 ms. Diverter plates are water-cooled heat sinks with armor tiles brazed on to the plasma facing side. Heat sink materials include OFHC, GlidcopTM, TZM, Mo-41Re, and niobium alloys. Armor tile materials include: carbon fiber composites, beryllium, silicon carbide, tungsten, and molybdenum. Tile thickness range from 2 - 10 mm, and heat sinks are 1 - 3 mm. A twisted tape insert is used to enhance heat transfer and increase the burnout safety margin from critical heat flux limits to 50 - 60 MW/m2 with water at 10 m/s and 4 MPa. Tests using rastered electron beams have shown thermal fatigue failures from cracks at the brazed interface between tiles and the heat sink after only 1000 cycles at 10 - 15 MW/m2. These fatigue lifetimes need to be increased an order of magnitude to meet future requirements. Other critical issues for plasma facing components include: surface erosion from sputtering and disruption erosion, eddy current forces and runaway electron impact from disruptions, neutron damage, tritium retention and release, remote maintenance of radioactive components, corrosion-erosion, and loss-of-coolant accidents.

Watson, Robert D.

1993-02-01

292

Stimulated scattering in laser driven fusion and high energy density physics experiments  

SciTech Connect

In laser driven fusion and high energy density physics experiments, one often encounters a k?{sub D} range of 0.15?

Yin, L., E-mail: lyin@lanl.gov; Albright, B. J.; Rose, H. A.; Montgomery, D. S.; Kline, J. L.; Finnegan, S. M.; Bergen, B.; Bowers, K. J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Kirkwood, R. K.; Milovich, J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

2014-09-15

293

High quality multi-focus image fusion using self-similarity and depth information  

NASA Astrophysics Data System (ADS)

Due to the limited depth of field in a camera, some imaging objects will be blurred if they are located far from the focus plane and the other objects on the plane will be clear. Multi-focus image fusion synthesizes a sharp image from multiple partially focused images. However, traditional fused images usually suffer from blurring effects and pixel distortions. In this paper, we explore two unique characteristics of multi-focus images: (1) The self-similarity of a single image and the shared similarity among multiple source images; (2) The distances from object to focal plane. The former characteristic is used to identify image structure-driven regions while the latter refine the image clarity by automatically estimating depth information of blurred images. Experimental results demonstrate that the proposed method outperforms the state-of-the-art fusion methods on image quality and objective fusion criteria.

Guo, Di; Yan, Jingwen; Qu, Xiaobo

2015-03-01

294

Highly toxic and broad-spectrum insecticidal local Bacillus strains engineered using protoplast fusion.  

PubMed

Protoplast fusion was performed between a local Bacillus thuringiensis UV-resistant mutant 66/1a (Bt) and Bacillus sphaericus GHAI (Bs) to produce new Bacillus strains with a wider spectrum of action against different insects. Bt is characterized as sensitive to polymyxin and streptomycin and resistant to rifampicin and has shown 87% mortality against Spodoptera littoralis larvae at concentration of 1.5 × 10(7) cells/mL after 7 days of feeding; Bs is characterized as resistant to polymyxin and streptomycin and sensitive to rifampicin and has been shown to have 100% mortality against Culex pipiens after 1 day of feeding at the same concentration as that of Bt. Among a total of 64 Bt::Bs fusants produced on the selective medium containing polymyxin, streptomycin, and rifampicin, 17 fusants were selected because of their high mortality percentages against S. littoralis (Lepidoptera) and C. pipiens (Diptera). While Bt harboured 3 plasmids (600, 350, and 173 bp) and Bs had 2 plasmids (544 and 291 bp), all the selected fusants acquired plasmids from both parental strains. SDS-PAGE protein analysis of the 17 selected fusants and their parental strains confirmed that all fusant strains acquired and expressed many specific protein bands from the 2 parental strains, especially the larvicidal proteins to both lepidopteran and dipteran species with molecular masses of 65, 70, 80, 88, 100, and 135 kDa. Four protein bands with high molecular masses of 281, 263, 220, and 190 kDa, which existed in the Bt parental strain and did not exist in the Bs parental strain, and 2 other protein bands with high molecular masses of 185 and 180 kDa, which existed in the Bs parental strain and did not exist in the Bt parental strain, were expressed in most fusants. The results indicated the expression of some cry genes encoded for insecticidal crystal proteins from Bt and the binary toxin genes from Bs in all fusant strains. The recombinant fusants have more efficient and potential values for agricultural application compared with both the insecticidal Bt and the mosquitocidal Bs strains alone against S. littoralis and C. pipiens larvae, respectively. PMID:25485592

El-Kawokgy, Tahany M A; Hussein, Hashem A; Aly, Nariman A H; Mohamed, Shereen A H

2015-01-01

295

Object-oriented change detection approach for high-resolution remote sensing images based on multiscale fusion  

NASA Astrophysics Data System (ADS)

Aiming at the difficulties in change detection caused by the complexity of high-resolution remote sensing images that exist in varied ecological environments and artificial objects, in order to overcome the limitations in traditional pixel-oriented change detection methods and improve the detection precision, an innovative object-oriented change detection approach based on multiscale fusion is proposed. This approach introduced the classical color texture segmentation algorithm J-segmentation (JSEG) to change detection and achieved the multiscale feature extraction and comparison of objects based on the sequence of J-images produced in JSEG. By comprehensively using the geometry, spectrum, and texture features of objects, and proposing two different multiscale fusing strategies, respectively, based on Dempster/Shafer evidence theory and weighted data fusion, the algorithm further improves the divisibility between changed and unchanged areas, thereby establishing an integrated framework of object-oriented change detection based on multiscale fusion. Experiments were performed on high-resolution airborne and SPOT 5 remote sensing images. Compared with different object-oriented and pixel-oriented detection methods, results of the experiments verified the validity and reliability of the proposed approach.

Wang, Chao; Xu, Mengxi; Wang, Xin; Zheng, Shengnan; Ma, Zhenli

2013-01-01

296

Investigation of equilibrium and nonlinear stability of high beta 3-D configurations  

NASA Astrophysics Data System (ADS)

3D MHD straight stellarator equilibria are generated with NIMROD. A vacuum equilibrium helical magnetic field is loaded in cylindrical geometry. This magnetic field is initialized to have a continuous symmetry or spoiled symmetry by adding 3D magnetic perturbations with helicities that are disproportionate with the dominant harmonic. These perturbations alter the magnetic spectrum, and produce magnetic islands and stochastic regions. Finite beta equilibria are generated via numerical simulation by introducing a heating source and employing self-consistent anisotropic pressure transport. A variety of magnetic configurations, including helically symmetric and spoiled symmetry cases, are investigated. To study the stability properties of 3D equilibria, finite beta equilibria are created which are helically symmetric. If the equilibrium is linearly unstable, MHD modes are triggered. The nonlinear consequences of violating MHD stability are simulated. These cases are compared to simulations of heated cases with fully 3D equilibrium fields, where symmetry-spoiling harmonics are added to the helically symmetric system and the degree of symmetry-spoiling is varied. Cases are shown where large differences are observed in the nonlinear time evolution of symmetric configurations compared with spoiled-symmetry configurations. The similarity between the effect of the magnitude of the symmetry-spoiling harmonics and the effect of varying the degree of anisotropic transport is studied.

Schlutt, M.; Hegna, C. C.; Sovinec, C. R.; Held, E. D.; Kruger, S. E.

2012-03-01

297

High-Dose Continuous Infusion Beta-lactam Antibiotics for the Treatment of Resistant Pseudomonas aeruginosa Infections in Immunocompromised Patients  

PubMed Central

OBJECTIVE To report a case series of high-dose continuous infusion beta-lactam antibiotics for the treatment of resistant Pseudomonas aeruginosa infections. CASE SUMMARY Continuous infusion ceftazidime or aztreonam was administered to achieve target drug levels at or above the MIC when possible in three patients with P. aeruginosa infections. The maximal calculated target drug level was 100 mg/L. In the first patient with primary immunodeficiency, neutropenia, and aggressive cutaneous T cell lymphoma/leukemia, continuous infusion ceftazidime (6.5 to 9.6 g/day) was used to successfully treat multidrug-resistant P. aeruginosa bacteremia. In the second patient with leukocyte adhesion deficiency type 1, continuous infusion aztreonam (8.4 g/day) was used to successfully treat multidrug-resistant P. aeruginosa wound infections. In the third patient with severe aplastic anemia, continuous infusion ceftazidime (7 to 16.8 g/day) was used to treat P. aeruginosa pneumonia and bacteremia. In each patient, the bacteremia cleared, infected wounds healed, and pneumonia improved in response to continuous infusion ceftazidime or aztreonam. DISCUSSION Treatment strategies for multidrug-resistant P. aeruginosa infections are limited. A novel treatment strategy when no other options are available is the administration of existing beta-lactam antibiotics by continuous infusion in order to maximize their pharmacodynamic activity. High-dose continuous infusion ceftazidime or aztreonam was used for the successful treatment of resistant systemic P. aeruginosa infections in three chronically immunocompromised patients. CONCLUSION Continuous infusion beta-lactam antibiotics are a potentially useful treatment strategy for resistant P. aeruginosa infections in immunocompromised patients. PMID:20371747

Moriyama, Brad; Henning, Stacey A.; Childs, Richard; Holland, Steven M.; Anderson, Victoria L.; Morris, John C.; Wilson, Wyndham H.; Drusano, George L.; Walsh, Thomas J.

2011-01-01

298

A high performance sensorimotor beta rhythm-based brain computer interface associated with human natural motor behavior  

NASA Astrophysics Data System (ADS)

To explore the reliability of a high performance brain-computer interface (BCI) using non-invasive EEG signals associated with human natural motor behavior does not require extensive training. We propose a new BCI method, where users perform either sustaining or stopping a motor task with time locking to a predefined time window. Nine healthy volunteers, one stroke survivor with right-sided hemiparesis and one patient with amyotrophic lateral sclerosis (ALS) participated in this study. Subjects did not receive BCI training before participating in this study. We investigated tasks of both physical movement and motor imagery. The surface Laplacian derivation was used for enhancing EEG spatial resolution. A model-free threshold setting method was used for the classification of motor intentions. The performance of the proposed BCI was validated by an online sequential binary-cursor-control game for two-dimensional cursor movement. Event-related desynchronization and synchronization were observed when subjects sustained or stopped either motor execution or motor imagery. Feature analysis showed that EEG beta band activity over sensorimotor area provided the largest discrimination. With simple model-free classification of beta band EEG activity from a single electrode (with surface Laplacian derivation), the online classifications of the EEG activity with motor execution/motor imagery were: >90%/~80% for six healthy volunteers, >80%/~80% for the stroke patient and ~90%/~80% for the ALS patient. The EEG activities of the other three healthy volunteers were not classifiable. The sensorimotor beta rhythm of EEG associated with human natural motor behavior can be used for a reliable and high performance BCI for both healthy subjects and patients with neurological disorders. Significance: The proposed new non-invasive BCI method highlights a practical BCI for clinical applications, where the user does not require extensive training.

Bai, Ou; Lin, Peter; Vorbach, Sherry; Floeter, Mary Kay; Hattori, Noriaki; Hallett, Mark

2008-03-01

299

Driver Technology for Inertial Fusion Research 1.Status of High Power Solid State Laser for Laser Fusion Experiments and the Prospect of Future Reactor Drivers  

NASA Astrophysics Data System (ADS)

The progress in development of high-power glass laser systems during the past 30 years is remarkable NIF (National Ignition Facility), which will deliver 1.8 MJ at 0.35 ?m is now construction in the United States. Recently, technology that smoothes out the focal pattern has been developed to a great extent. RPP (Random Phase Plate) and PCL (Partially Coherent Laser) both gave an excellent focal pattern with standard deviation of 3% in the Gekko XII laser system. In the US, Japan and Europe, several ultra-short pulse lasers were developed for research on “fast ignition”. “Fast ignition” is a method which will reduce the total required laser energy for ignition. Because a diode-pumped, solid state laser can operate at a repetition rate of over 10 Hz with an efficiency of about 10% research area of high-power systems at the 1 kW level started to focus on the development of a driver for a commercial laser fusion reactor.

Fujita, Hisanori

300

ChemTeacher: Beta Decay  

NSDL National Science Digital Library

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

2011-01-01

301

Apolipoprotein E: High-Avidity Binding to beta-Amyloid and Increased Frequency of Type 4 Allele in Late-Onset Familial Alzheimer Disease  

Microsoft Academic Search

Apolipoprotein E is immunochemically localized to the senile plaques, vascular amyloid, and neurofibrillary tangles of Alzheimer disease. In vitro, apolipoprotein E in cerebrospinal fluid binds to synthetic beta A4 peptide (the primary constituent of the senile plaque) with high avidity. Amino acids 12-28 of the beta A4 peptide are required. The gene for apolipoprotein E is located on chromosome 19q13.2,

Warren J. Strittmatter; Ann M. Saunders; Donald Schmechel; Margaret Pericak-Vance; Jan Enghild; Guy S. Salvesen; Allen D. Roses

1993-01-01

302

Development of a magnetohydrodynamic code for axisymmetric, high-. beta. plasmas with complex magnetic fields  

SciTech Connect

The Topolotron is an axisymmetric, toroidal magnetic fusion concept in which two-dimensional effects are important, as well as all three magnetic field components. The particular MHD model employed is basically the one-fluid, two-temperature model using classical Braginskii transport with viscous effects ignored. The model is augmented by Saha-Boltzmann dissociation and partial ionization physics, a simple radiation loss mechanism, and an additional resistivity due to electron-neutral collisions. While retaining all velocity and magnetic field components, the assumption of axisymmetry is made, and the resulting equations are expanded in cylindrical coordinates. The major approximation technique is then applied: spline collocation, which reduces these equations to a set of ordinary differential equations.

Cook, G.O. Jr.

1982-12-01

303

High-speed repeating hydrogen pellet injector for long-pulse magnetic confinement fusion experiments  

NASA Astrophysics Data System (ADS)

The projected fueling requirements of future magnetic confinement fusion devices [e.g., the International Thermonuclear Experimental Reactor (ITER)] indicate the need for a flexible plasma fueling capability, including both gas puffing and low- and high-speed pellet injection. Conventional injectors, based on single-stage pneumatic guns or centrifuges, can reliably provide frozen pellets (1- to 6-mm-diam sizes) at speeds up to 1.3 km/s and at suitable repetition rates (1 to 10 Hz or greater). Injectors based on two-stage pneumatic guns and ``in situ'' condensation of hydrogen pellets can reliably achieve velocities over 3 km/s; however, they are not suitable for long-pulse repetitive operations. An experiment in collaboration between Oak Ridge National Laboratory (ORNL) and ENEA Frascati is under way to demonstrate the feasibility of a high-speed (?2 km/s) repeating (˜1 Hz) pneumatic pellet injector for long-pulse operation. A test facility has been assembled at ORNL, combining a Frascati repeating two-stage light-gas gun and an ORNL deuterium extruder, equipped with a pellet chambering mechanism/gun barrel assembly. The main issues to be investigated were the strength of extruded deuterium ice as opposed to that produced by in situ condensation in pipe guns (hence the highest acceleration which can be given to the pellet without fracturing it), and the maximum repetition rate at which the system can operate without degradation in performance. Pellet velocities of up to 2.55 km/s have been achieved in joint experiments at ORNL. A new pressure tailoring valve was developed by the Frascati group for this application and proved to be a crucial component for good performance. Tests carried out in repeating mode, at frequencies of 0.2-0.5 Hz and speeds up to 2.2 km/s, indicate no significant degradation in performance with increasing repetition rate. Some preliminary tests using 3.7 mm pellets gave very encouraging results. The equipment and the experimental results are described in this article.

Frattolillo, A.; Migliori, S.; Scaramuzzi, F.; Combs, S. K.; Baylor, L. R.; Foust, C. R.; Gouge, M. J.; Milora, S. L.

1996-05-01

304

SIMULATIONS OF ALPHA PARAMETERS IN A TFTR DT SUPERSHOT WITH HIGH FUSION POWER  

E-print Network

of the deuterium and tritium densities, the hydrogenic isotopic mass, the fusion reactions, the fast ion parameters isotopic scaling of the thermal plasma confinement with isotopic mass [8, 91. Several methods are being charge exchange recombina- tion spectroscopy of alphas excited by NBI ions [lo]. Another method analyses

Budny, Robert

305

Wild topology, hyperbolic geometry and fusion algebra of high energy particle physics  

Microsoft Academic Search

The relation between Wild Topology, Hyperbolic Geometry and Fusion Algebra on the one side and the charge and coupling constants of the standard model and quantum gravity on the other is examined.The close connection found between E(?) theory and the Topological theory of four manifolds as well as the theory of fundamental groups is elucidated using various classical theories and

M. S. El Naschie

2002-01-01

306

MultiSensor Data Fusion for High-Resolution Material Characterization  

Microsoft Academic Search

In typical nondestructive evaluation (NDE) of materials, the material under test is inspected using one or more NDE techniques to evaluate its condition. However, measurement data from different inspection techniques are often complementary in nature and higher accuracy may be achieved by fusing information from these different inspection modes. This paper proposes a classifier-fusion based approach to combine multifrequency eddy

Juanita Dion; Mrityunjay Kumar; Pradeep Ramuhalli

2007-01-01

307

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

SciTech Connect

An explanation for the strong dependency of crack initiation of precracked high-strength {beta}-titanium alloys in room-temperature 0.6 M NaCl on applied potential and bulk-solution pH is presented. It is proposed that environment-assisted cracking (EAC) susceptibility in neutral aqueous NaCl results from (1) film rupture due to plastic deformation at actively deformed crack tips, (2) accelerated dissolution of titanium, (3) crack tip acidification by hydrolysis of titanium ions, (4) crack tip potential excursions toward bare metal open-circuit potentials (OCPs) during film rupture due to large ohmic voltages in the crack solution, (5) accelerated crack tip proton or water reduction concurrent with titanium dissolution, (6) bare surface-dominated hydrogen ingress into a fracture process zone, and (7) crack initiation by hydrogen embrittlement. Evidence for each of the above stages of the crack initiation scenario is presented, with emphasis on crack tip electrode kinetics and ohmic voltage calculations which govern process zone-controlled hydrogen uptake. The seven stages are consistent with the strong dependencies of crack initiation and growth in precracked high-strength {beta}-titanium alloys on (1) solution pH, (2) applied potential, and (3) strain rate, and they explain the apparent EAC resistance of smooth- and blunt-notch specimens. The latter lack both occluded crack tip geometries to promote acidification and ohmic voltage drops below reversible hydrogen, as well as localization of dynamic plastic strain. Hydrogen uptake is, subsequently, limited.

Kolman, D.G.; Scully, J.R. [Univ. of Virginia, Charlottesville, VA (United States)

1997-12-01

308

Sub-millimeter nuclear medical imaging with high sensitivity in positron emission tomography using beta-gamma coincidences  

E-print Network

We present a nuclear medical imaging technique, employing triple-gamma trajectory intersections from beta^+ - gamma coincidences, able to reach sub-millimeter spatial resolution in 3 dimensions with a reduced requirement of reconstructed intersections per voxel compared to a conventional PET reconstruction analysis. This '$\\gamma$-PET' technique draws on specific beta^+ - decaying isotopes, simultaneously emitting an additional photon. Exploiting the triple coincidence between the positron annihilation and the third photon, it is possible to separate the reconstructed 'true' events from background. In order to characterize this technique, Monte-Carlo simulations and image reconstructions have been performed. The achievable spatial resolution has been found to reach ca. 0.4 mm (FWHM) in each direction for the visualization of a 22Na point source. Only 40 intersections are sufficient for a reliable sub-millimeter image reconstruction of a point source embedded in a scattering volume of water inside a voxel volume of about 1 mm^3 ('high-resolution mode'). Moreover, starting with an injected activity of 400 MBq for ^76Br, the same number of only about 40 reconstructed intersections are needed in case of a larger voxel volume of 2 x 2 x 3~mm^3 ('high-sensitivity mode'). Requiring such a low number of reconstructed events significantly reduces the required acquisition time for image reconstruction (in the above case to about 140 s) and thus may open up the perspective for a quasi real-time imaging.

C. Lang; D. Habs; K. Parodi; P. G. Thirolf

2014-02-15

309

Observation of finite-. beta. MHD phenomena in tokamaks  

SciTech Connect

Stable high-beta plasmas are required for the tokamak to attain an economical fusion reactor. Recently, intense neutral beam heating experiments in tokamaks have shown new effects on plasma stability and confinement associated with high beta plasmas. The observed spectrum of MHD fluctuations at high beta is clearly dominated by the n = 1 mode when the q = 1 surface is in the plasma. The m/n = 1/1 mode drives other n = 1 modes through toroidal coupling and n > 1 modes through nonlinear coupling. On PDX, with near perpendicular injection, a resonant interaction between the n = 1 internal kink and the trapped fast ions results in loss of beam particles and heating power. Key parameters in the theory are the value of q/sub 0/ and the injection angle. High frequency broadband magnetic fluctuations have been observed on ISX-B and D-III and a correlation with the deterioration of plasma confinement was reported. During enhanced confinement (H-mode) discharges in divertor plasmas, two new edge instabilities were observed, both localized radially near the separatrix. By assembling results from the different tokamak experiments, it is found that the simple theoretical ideal MHD beta limit has not been exceeded. Whether this represents an ultimate tokamak limit or if beta optimized configurations (Dee- or bean-shaped plasmas) can exceed this limit and perhaps enter a second regime of stability remains to be clarified.

McGuire, K.M.

1984-09-01

310

Measuring situational awareness and resolving inherent high-level fusion obstacles  

NASA Astrophysics Data System (ADS)

Information Fusion Engine for Real-time Decision Making (INFERD) is a tool that was developed to supplement current graph matching techniques in Information Fusion models. Based on sensory data and a priori models, INFERD dynamically generates, evolves, and evaluates hypothesis on the current state of the environment. The a priori models developed are hierarchical in nature lending them to a multi-level Information Fusion process whose primary output provides a situational awareness of the environment of interest in the context of the models running. In this paper we look at INFERD's multi-level fusion approach and provide insight on the inherent problems such as fragmentation in the approach and the research being undertaken to mitigate those deficiencies. Due to the large variance of data in disparate environments, the awareness of situations in those environments can be drastically different. To accommodate this, the INFERD framework provides support for plug-and-play fusion modules which can be developed specifically for domains of interest. However, because the models running in INFERD are graph based, some default measurements can be provided and will be discussed in the paper. Among these are a Depth measurement to determine how much danger is presented by the action taking place, a Breadth measurement to gain information regarding the scale of an attack that is currently happening, and finally a Reliability measure to tell the user the credibility of a particular hypothesis. All of these results will be demonstrated in the Cyber domain where recent research has shown to be an area that is welldefined and bounded, so that new models and algorithms can be developed and evaluated.

Sudit, Moises; Stotz, Adam; Holender, Michael; Tagliaferri, William; Canarelli, Kathie

2006-04-01

311

Ion-scale spectral break of solar wind turbulence at high and low beta  

NASA Astrophysics Data System (ADS)

The power spectrum of magnetic fluctuations in the solar wind at 1 AU displays a break between two power laws in the range of spacecraft-frame frequencies 0.1 to 1 Hz. These frequencies correspond to spatial scales in the plasma frame near the proton gyroradius ?i and proton inertial length di. At 1 AU it is difficult to determine which of these is associated with the break, since di=?i/?{? ?i} and the perpendicular ion plasma beta is typically ??i˜1. To address this, several exceptional intervals with ??i?1 and ??i?1 were investigated, during which these scales were well separated. It was found that for ??i?1 the break occurs at di and for ??i?1 at ?i, i.e., the larger of the two scales. Possible explanations for these results are discussed, including Alfvén wave dispersion, damping, and current sheets.

Chen, C. H. K.; Leung, L.; Boldyrev, S.; Maruca, B. A.; Bale, S. D.

2014-11-01

312

High efficiency microfluidic beta detector for pharmacokinetic studies in small animals  

NASA Astrophysics Data System (ADS)

New radiotracers are continuously being developed to improve diagnostic efficiency using Single Photon Emission Computed Tomography (SPECT) or Positron Emission Tomography (PET). The characterization of their pharmacokinetics requires blood radioactivity monitoring over time during the scan and is very challenging in small animals because of the low volume of blood available. In this work, a prototype microfluidic blood counter made of a microchannel atop a silicon substrate containing PIN photodiodes is proposed to improve beta detection efficiency in a small volume by eliminating unnecessary interfaces between fluid and detector. A flat rectangular-shaped epoxy channel, 36 ?m×1.26 mm cross section and 31.5 mm in length, was microfabricated over a die containing an array of 2×2 mm 2 PIN photodiodes, leaving only a few micrometers of epoxy floor layer between the fluid and the photodiode sensitive surface. This geometry leads to a quasi 2D source, optimizing geometrical detection efficiency that was estimated at 41% using solid angle calculation. CV- IV measurements were made at each fabrication step to confirm that the microchannel components had no significant effects on the diodes' electrical characteristics. The chip was wire-bonded to a PCB and connected to charge sensitive preamplifier and amplifier modules for pulse shaping. Energy spectra recorded for different isotopes showed continuous beta distribution for PET isotopes and monoenergetic conversion electron peaks for 99mTc. Absolute sensitivity was determined for the most popular PET and SPECT radioisotopes and ranged from 26% to 33% for PET tracers ( 18F, 13N, 11C, 68Ga) and more than 2% for 99mTc. Input functions were successfully simulated with 18F, confirming the setup's suitability for pharmacokinetic modeling of PET and SPECT radiotracers in animal experiments. By using standard materials and procedures, the fabrication process is well suited to on-chip microfluidic functionality, allowing full characterization of new radiotracers.

Convert, Laurence; Girard-Baril, Frédérique; Renaudin, Alan; Grondin, Étienne; Jaouad, Abdelatif; Aimez, Vincent; Charette, Paul; Lecomte, Roger

2011-10-01

313

An overview of LLNL high-energy short-pulse technology for advanced radiography of laser fusion experiments  

NASA Astrophysics Data System (ADS)

The technical challenges and motivations for high-energy, short-pulse generation with NIF and possibly other large-scale Nd : glass lasers are reviewed. High-energy short-pulse generation (multi-kilojoule, picosecond pulses) will be possible via the adaptation of chirped pulse amplification laser techniques on NIF. Development of metre-scale, high-efficiency, high-damage-threshold final optics is a key technical challenge. In addition, deployment of high energy petawatt (HEPW) pulses on NIF is constrained by existing laser infrastructure and requires new, compact compressor designs and short-pulse, fibre-based, seed-laser systems. The key motivations for HEPW pulses on NIF is briefly outlined and includes high-energy, x-ray radiography, proton beam radiography, proton isochoric heating and tests of the fast ignitor concept for inertial confinement fusion.

Barty, C. P. J.; Key, M.; Britten, J.; Beach, R.; Beer, G.; Brown, C.; Bryan, S.; Caird, J.; Carlson, T.; Crane, J.; Dawson, J.; Erlandson, A. C.; Fittinghoff, D.; Hermann, M.; Hoaglan, C.; Iyer, A.; Jones, L., II; Jovanovic, I.; Komashko, A.; Landen, O.; Liao, Z.; Molander, W.; Mitchell, S.; Moses, E.; Nielsen, N.; Nguyen, H.-H.; Nissen, J.; Payne, S.; Pennington, D.; Risinger, L.; Rushford, M.; Skulina, K.; Spaeth, M.; Stuart, B.; Tietbohl, G.; Wattellier, B.

2004-12-01

314

Excitation of high frequency pressure driven modes by non-axisymmetric equilibrium at high {beta}{sub pol} in PBX-M  

SciTech Connect

High-frequency pressure-driven modes have been observed in high-poloidal-{beta} discharges in the Princeton Beta Experiment-Modification (PBX-M). These modes are excited in a non-axisymmetric equilibrium characterized by a large, low frequency m{sub 1}=1/n{sub 1}=1 island, and they are capable of expelling fast ions. The modes reside on or very close to the q=1 surface, and have mode numbers with either m{sub h}=n{sub h} or (less probably) m{sub h}/n{sub h}=m{sub h}/(m{sub h}-1), with m{sub h} varying between 3 and 10. Occasionally, these modes are, simultaneously localized in the vicinity of the m{sub 1}=2/n{sub 1}=1 island. The high frequency modes near the q=1 surface also exhibit a ballooning character, being significantly stronger on the large major radius side of the plasma. When a large m{sub 1}=1/n{sub 1}=1 island is present the mode is poloidally localized in the immediate vicinity of the x-point of the island. The modes, which occur exclusively in high-{beta} discharges, appear to be driven by the plasma pressure or pressure gradient. They can thus be a manifestation of either a toroidicity-induced shear Alfven eigenmode (TAE) at q=(2m{sub h}+ 1)/2n{sub h}, a kinetic ballooning mode (KBM), or some other type of pressure-driven mode. Theory predicts that the TAE mode is a gap mode, but the high frequency modes in PBX-M are found exclusively on or in the immediate neighborhood of magnetic surfaces with low rational numbers.

Sesnic, S.; Kaita, R.; Kaye, S.; Okabayashi, M.; Takahashi, H.; Bell, R.E.; Bernabei, S.; Chance, M.S.; Hatcher, R.E.; Jardin, S.C.; Kessel, C.E.; Kugel, H.W.; LeBlanc, B.; Manickam, J.; Ono, M.; Paul, S.F.; Sauthoff, N.R. [Princeton Univ., NJ (United States). Plasma Physics Lab.; Holland, A. [ARACOR, Sunnyvale, CA (United States); Asakura, N. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan); Duperrex, P.A. [Lab. pour l`Armenment, Berne (Switzerland); Fonck, R.J. [Wisconsin Univ., Madison, WI (United States). Dept. of Nuclear Engineering; Gammel, G.M. [Grumman Aerospace Corp., Bethpage, NY (United States); Greene, G.J. [Greene (G.J.), West Trenton, NJ (United States); Jiang, T.W. [Academia Sinica, Hefei, AH (China). Inst. of Plasma Physics; Levinton, F.M. [Fusion Physics and Technology, Torrance, CA (United States); Powell, E.T.; Roberts, D.W. [Lawrence Livermore National Lab., CA (United States); Qin, Y. [Southwest Inst. of Physics, Leshan, SC (China)

1993-06-01

315

A NPxY-independent {beta}5 integrin activation signal regulates phagocytosis of apoptotic cells  

SciTech Connect

Integrin receptors are heterodimeric transmembrane receptors with critical functions in cell adhesion and migration, cell cycle progression, differentiation, apoptosis, and phagocytosis of apoptotic cells. Integrins are activated by intracellular signaling that alter the binding affinity for extracellular ligands, so-called inside to outside signaling. A common element for integrin activation involves binding of the cytoskeletal protein talin, via its FERM domain, to a highly conserved NPxY motif in the {beta} chain cytoplasmic tails, which is involved in long-range conformation changes to the extracellular domain that impinges on ligand affinity. When the human beta-5 ({beta}5) integrin cDNA was expressed in {alpha}v positive, {beta}5 and {beta}3 negative hamster CS-1 cells, it promoted NPxY-dependent adhesion to VTN-coated surfaces, phosphorylation of FAK, and concomitantly, {beta}5 integrin-EGFP protein was recruited into talin and paxillin-containing focal adhesions. Expression of a NPxY destabilizing {beta}5 mutant (Y750A) abrogated adhesion and {beta}5-Y750A-EGFP was excluded from focal adhesions at the tips of stress fibers. Surprisingly, expression of {beta}5 Y750A integrin had a potent gain-of-function effect on apoptotic cell phagocytosis, and further, a {beta}5-Y750A-EGFP fusion integrin readily bound MFG-E8-coated 10 {mu}m diameter microspheres developed as apoptotic cell mimetics. The critical sequences in {beta}5 integrin were mapped to a YEMAS motif just proximal to the NPxY motif. Our studies suggest that the phagocytic function of {beta}5 integrin is regulated by an unconventional NPxY-talin-independent activation signal and argue for the existence of molecular switches in the {beta}5 cytoplasmic tail for adhesion and phagocytosis.

Singh, Sukhwinder; D'mello, Veera [Department of Biochemistry and Molecular Biology, UMDNJ-New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103-6399 (United States); Henegouwen, Paul van Bergen en [Utrecht University, Department of Molecular Cell Biology, Padualaan 8 3584 CH Utrecht (Netherlands); Birge, Raymond B. [Department of Biochemistry and Molecular Biology, UMDNJ-New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103-6399 (United States); Utrecht University, Department of Molecular Cell Biology, Padualaan 8 3584 CH Utrecht (Netherlands)], E-mail: birgera@umdnj.edu

2007-12-21

316

Optimization of a high-throughput whole blood expression profiling methodology and its application to assess the pharmacodynamics of interferon (IFN) beta-1a or polyethylene glycol-conjugated IFN beta-1a in healthy clinical trial subjects  

PubMed Central

Background Clinical trials offer a unique opportunity to study human disease and response to therapy in a highly controlled setting. The application of high-throughput expression profiling to peripheral blood from clinical trial subjects could facilitate the identification of transcripts that function as prognostic or diagnostic markers of disease or treatment. The paramount issue for these methods is the ability to produce robust, reproducible, and timely mRNA expression profiles from peripheral blood. Single-stranded complementary DNA (sscDNA) targets derived from whole blood exhibit improved detection of transcripts and reduced variance as compared to their complementary RNA counterparts and therefore provide a better option for interrogation of peripheral blood on oligonucleotide arrays. High-throughput microarray technologies such as the high-throughput plate array platform offer several advantages compared with slide- or cartridge-based arrays; however, manufacturer’s protocols do not support the use of sscDNA targets. Results We have developed a highly reproducible, high-through put, whole blood expression profiling methodology based on sscDNA and used it to analyze human brain reference RNA and universal human reference RNA samples to identify experimental conditions that most highly correlated with a gold standard quantitative polymerase chain reaction reference dataset. We then utilized the optimized method to analyze whole blood samples from healthy clinical trial subjects treated with different versions of interferon (IFN) beta-1a. Analysis of whole blood samples before and after treatment with intramuscular [IM] IFN beta-1a or polyethylene glycol-conjugated IFN (PEG-IFN) beta-1a under optimized experimental conditions demonstrated that PEG-IFN beta-1a induced a more sustained and prolonged pharmacodynamic response than unmodified IM IFN beta-1a. These results provide validation of the utility of this new methodology and suggest the potential therapeutic benefit of a sustained pharmacodynamic response to PEG-IFN beta-1a. Conclusions This novel microarray methodology is ideally suited for utilization in large clinical studies to identify expressed transcripts for the elucidation of disease mechanisms of action and as prognostic, diagnostic, or toxicity markers. PMID:23289891

2013-01-01

317

High Energy Electron Confinement in a Magnetic Cusp Configuration  

E-print Network

We report experimental results validating the concept that plasma confinement is enhanced in a magnetic cusp configuration when beta (plasma pressure/magnetic field pressure) is order of unity. This enhancement is required for a fusion power reactor based on cusp confinement to be feasible. The magnetic cusp configuration possesses a critical advantage: the plasma is stable to large scale perturbations. However, early work indicated that plasma loss rates in a reactor based on a cusp configuration were too large for net power production. Grad and others theorized that at high beta a sharp boundary would form between the plasma and the magnetic field, leading to substantially smaller loss rates. The current experiment validates this theoretical conjecture for the first time and represents critical progress toward the Polywell fusion concept which combines a high beta cusp configuration with an electrostatic fusion for a compact, economical, power-producing nuclear fusion reactor.

Park, Jaeyoung; Sieck, Paul E; Offermann, Dustin T; Skillicorn, Michael; Sanchez, Andrew; Davis, Kevin; Alderson, Eric; Lapenta, Giovanni

2014-01-01

318

New medium composition for high betacyanin production by a cell suspension culture of table beet (Beta vulgaris L.).  

PubMed

The effect of a revised Linsmaier-Skoog (LS) medium on betacyanin production was investigated in suspension cultures of table beet (Beta vulgaris L.). The effects of a high iron concentration and low concentration of zinc on betacyanin production were not cumulative. The composition of the new revised medium for high betacyanin production was established by reducing the concentration of inorganic nitrogen (30 mM), modifying the ratio of ammonium to nitrate (1:14), reducing the concentration of zinc (0.0003 mM), and removing copper and cobalt. The revised LS medium enabled the maximum betacyanin yield of 550 mg/l to be obtained from a 14-day culture. This medium promoted the betacyanin production in three types of cell line differing in the betacyanin productivity. The betacyanin productivity (40 mg/l x day) was higher than that quoted in any other previous reports. PMID:12036073

Akita, Toru; Hina, Yasuhiko; Nishi, Toyoyuki

2002-04-01

319

Accessible Passively Stored Highly Spin-Polarized Deuterium in Solid Hydrogen Deuterium, with Application to Inertially Confined Fusion  

NASA Astrophysics Data System (ADS)

Highly spin-polarized D in solid HD was produced in a dilution refrigerator-magnet system under conditions whereby the polarization remains high upon removal of the sample to a 1K, modest field (~0.1 T) environment. This retained polarization remains for many hours to days, sufficient to allow the polarized material to be transported to distant locations and utilized there. The first intended application of this system is for inertially confined fusion (ICF) experiments with spin-polarized D fuel. The actual (vector) polarization attained thus far is P^{rm D} = 38%. The maximum D polarization obtainable with our present refrigerator and magnet (8 mK and 13 T) is 61%. The difference is due to our reluctance to wait the full time constants in these demonstration experiments and due to the inability to attain full efficiency in radio-frequency dynamic polarization transfer between D and H, the maximum polarizability of the latter in our system equaling about 85%. In addition to implementation of the polarization method, it was also necessary to develop methods for cold (4 K) sample transfer with engagement and disengagement provisions for the dilution-refrigerator apparatus, a storage -transport cryostat, various sample-preparation and diagnostic apparatuses, and an interface to an experimental destination facility, in the present case, the OMEGA fusion chamber at the University of Rochester's Laboratory for Laser Energetics. The nature of the fusion experiments required designing and constructing a complex mating system with interchange of cold shrouds to ascertain the sample was always shielded from room temperature black body radiation, and still provide means for positioning the target to within a few microns of the intersection of the high power laser beams. Means of filling plastic target shells to high pressure (at room temperature) with our special isotopic composition of HD with H_2 and D_2 impurities, and condensing them at cryogenic temperatures, were also perfected.

Alexander, Neil Brooks

1992-01-01

320

Missile generation due to electrical arcing in high field fusion magnets  

SciTech Connect

Large amounts of energy (10 /sup 10/-10/sup 11/ J) are stored in the magnetic field of superconducting magnet systems used in conceptual fusion-reactor designs. If only part of this energy is released accidentally, damage to the magnet and to other rector subsystems may result. In fusion-reactor environments it may lead to the evaporation of activated material and to the generation of energetic missiles, involving interference with sources of radioaactive material in the plant. Results from a Runge-Kutta routine have been obtained for FINTOR, a minimum size Tokamak DT experimental reactor, indicating that missiles of about 20 kg weight may reach velocities in the order of 100 m/s.

Schneider, H.; Caretta, A.

1981-01-01

321

Multi-Sensor Data Fusion for High-Resolution Material Characterization  

NASA Astrophysics Data System (ADS)

In typical nondestructive evaluation (NDE) of materials, the material under test is inspected using one or more NDE techniques to evaluate its condition. However, measurement data from different inspection techniques are often complementary in nature and higher accuracy may be achieved by fusing information from these different inspection modes. This paper proposes a classifier-fusion based approach to combine multifrequency eddy current and ultrasound data for material characterization. The proposed algorithm uses a hierarchy of classifiers to determine the material state (e.g. stress, heat treatment etc.) and level of exposure to this condition, with classifier fusion achieved through a majority-voting rule. Preliminary results on applying the proposed algorithm to data from Inconel 600 samples are presented.

Dion, Juanita; Kumar, Mrityunjay; Ramuhalli, Pradeep

2007-03-01

322

SIPHORE: Conceptual Study of a High Efficiency Neutral Beam Injector Based on Photo-detachment for Future Fusion Reactors  

SciTech Connect

An innovative high efficiency neutral beam injector concept for future fusion reactors is under investigation (simulation and R and D) between several laboratories in France, the goal being to perform a feasibility study for the neutralization of intense high energy (1 MeV) negative ion (NI) beams by photo-detachment.The objective of the proposed project is to put together the expertise of three leading groups in negative ion quantum physics, high power stabilized lasers and neutral beam injectors to perform studies of a new injector concept called SIPHORE (SIngle gap PHOto-neutralizer energy REcovery injector), based on the photo-detachment of negative ions and energy recovery of unneutralised ions; the main feature of SIPHORE being the relevance for the future Fusion reactors (DEMO), where high injector efficiency (up to 70-80%), technological simplicity and cost reduction are key issues to be addressed.The paper presents the on-going developments and simulations around this project, such as, a new concept of ion source which would fit with this injector topology and which could solve the remaining uniformity issue of the large size ion source, and, finally, the presentation of the R and D program in the laboratories (LAC, ARTEMIS) around the photo-neutralization for Siphore.

Simonin, A.; Christin, L.; Esch, H. de; Garibaldi, P.; Grand, C.; Villecroze, F. [IRFM, CEA Cadarache, IRFM, St. Paul-lez-Durance (France); Blondel, C.; Delsart, C.; Drag, C.; Vandevraye, M. [LAC :Aime-Cotton Laboratory, Univ. Paris-sud, Orsay (France); Brillet, A.; Chaibi, W. [ARTEMIS Laboratory, Cote-d'azur Observatory, Nice (France)

2011-09-26

323

Facility for high-heat flux testing of irradiated fusion materials and components using infrared plasma arc lamps  

NASA Astrophysics Data System (ADS)

A new high-heat flux testing (HHFT) facility using water-wall stabilized high-power high-pressure argon plasma arc lamps (PALs) has been developed for fusion applications. It can accommodate irradiated plasma facing component materials and sub-size mock-up divertor components. Two PALs currently available at Oak Ridge National Laboratory can provide maximum incident heat fluxes of 4.2 and 27 MW m-2, which are prototypic of fusion steady state heat flux conditions, over a heated area of 9 × 12 and 1 × 10 cm2, respectively. The use of PAL permits the heat source to be environmentally separated from the components of the test chamber, simplifying the design to accommodate safe testing of low-level irradiated articles and materials under high-heat flux. Issues related to the operation and temperature measurements during testing of tungsten samples are presented and discussed. The relative advantages and disadvantages of this photon-based HHFT facility are compared to existing e-beam and particle beam facilities used for similar purposes.

Sabau, Adrian S.; Ohriner, Evan K.; Kiggans, Jim; Harper, David C.; Snead, Lance L.; Schaich, Charles R.

2014-04-01

324

Ultra-High Expression of a Thermally Responsive Recombinant Fusion Protein in E. coli  

PubMed Central

Elastin-like polypeptides (ELPs) are recombinant peptide-based biopolymers that contain repetitive sequences enriched in glycine, valine, proline, and alanine. Because of the unusually large fraction of these amino acids in ELPs as compared to other cellular proteins, we hypothesized that intracellular pools of these amino acids can be selectively depleted and limit protein yields during expression. In this study, we examined how culture conditions and individual medium components affect protein yields by monitoring cell growth and protein expression kinetics of E. coli expressing an ELP tagged with a green fluorescent protein (GFP). By determining the underlying principles of superior fusion protein yields generated by the hyperexpression protocol, we further improved protein yields through the addition of glycerol and certain amino acids such as proline and alanine, and found that amino acid concentrations and the type of basal medium used strongly influenced this beneficial effect. Surprisingly, amino acids other than those that are abundant in ELPs, for example, asparagine, aspartic acid, glutamine, and glutamic acid, also enhanced protein yields even in a nutrient-rich medium. Compared to commonly-used Luria-Bertani medium, the protein yield was improved by 36-fold to the remarkable level of 1.6 g/L in shaker flask cultures with a modified medium and optimized culture conditions, which also led to a 8-fold reduction in the cost of the fusion protein. To our knowledge, this is the highest yield of an ELP-fusion protein purified from E. coli cultured in shaker flasks. This study also suggests a useful strategy to improve the yields of other ELP fusion proteins and repetitive polypeptides. PMID:16739944

Chow, Dominic C.; Dreher, Matthew R.; Trabbic-Carlson, Kimberly; Chilkoti, Ashutosh

2008-01-01

325

Hard x-ray backlighters for high resolution Compton radiography of Inertial Confinement Fusion targets  

Microsoft Academic Search

Radiographs of the final stages of imploding DT fuel in inertial confinement fusion experiments will be extremely valuable for checking the convergence, areal density and areal density uniformity of the fuel. For x-rays with energies between 30 and 200 keV, the main opacity will be due to Compton scattering. Here we present the demonstration of 75-200 keV point backlighter sources

R. Tommasini; A. Macphee; D. Hey; T. Ma; C. Chen; N. Izumi; A. MacKinnon; S. P. Hatchett; J. A. Koch; P. Springer; O. L. Landen

2008-01-01

326

Highly dynamic fission–fusion species can exhibit leadership when traveling  

Microsoft Academic Search

Leadership by specific individuals is thought to enhance the fitness of followers by allowing them to take advantage of the\\u000a knowledge or skills of key individuals. In general, consistent leadership is expected to occur primarily in stable groups\\u000a of related individuals where the benefits enhance the inclusive fitness of a leader. Societies with less stability in group\\u000a composition (i.e., fission–fusion

Jennifer S. Lewis; Douglas Wartzok; Michael R. Heithaus

2011-01-01

327

Microstructural evolution of fusion zone in laser beam welds of pure titanium  

SciTech Connect

Microstructural evolution of fusion zone in laser beam welds of pure titanium was studied by means of electron backscattering diffraction. The microstructural evolution is strongly affected by the {beta} {yields} {alpha} transformation mechanism dependent on the cooling rate during phase transformation. The long-range diffusional transformation mainly occurs in the fusion zone at the low cooling rate, and the massive transformation dominantly takes place at the high cooling rate. For this reason, the grain morphologies probably change from the granular-like to columnar-like grains with the cooling rate increasing. - Highlights: Black-Right-Pointing-Pointer Microstructures of fusion zone in laser beam welds of pure titanium are studied. Black-Right-Pointing-Pointer Increasing cooling rate changes grain morphology from granular to columnar one. Black-Right-Pointing-Pointer Final microstructures depend on the {beta}{yields}{alpha} transformation mechanisms.

Liu, H., E-mail: hitliuhong@163.com [State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049 (China) and Joining and Welding Research Institute, Osaka University, Ibaraki 567-0047 (Japan); Nakata, K. [Joining and Welding Research Institute, Osaka University, Ibaraki 567-0047 (Japan); Zhang, J.X. [State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049 (China); Yamamoto, N.; Liao, J. [Technology Development Headquarters, Kurimoto Ltd., Osaka 559-0021 (Japan)

2012-03-15

328

Beta-manganese dioxide nanorods for sufficient high-temperature electromagnetic interference shielding in X-band  

NASA Astrophysics Data System (ADS)

As the development of electronic and communication technology, electromagnetic interference (EMI) shielding and attenuation is an effective strategy to ensure the operation of the electronic devices. Among the materials for high-performance shielding in aerospace industry and related high-temperature working environment, the thermally stable metal oxide semiconductors with narrow band gap are promising candidates. In this work, beta-manganese dioxide ( ?-MnO2) nanorods were synthesized by a hydrothermal method. The bulk materials of the ?-MnO2 were fabricated to evaluate the EMI shielding performance in the temperature range of 20-500 °C between 8.2 and 12.4 GHz (X-band). To understand the mechanisms of high-temperature EMI shielding, the contribution of reflection and absorption to EMI shielding was discussed based on temperature-dependent electrical properties and complex permittivity. Highly sufficient shielding effectiveness greater than 20 dB was observed over all the investigated range, suggesting ?-MnO2 nanorods as promising candidates for high-temperature EMI shielding. The results have also established a platform to develop high-temperature EMI shielding materials based on nanoscale semiconductors.

Song, Wei-Li; Cao, Mao-Sheng; Hou, Zhi-Ling; Lu, Ming-Ming; Wang, Chan-Yuan; Yuan, Jie; Fan, Li-Zhen

2014-09-01

329

Extended steady-state and high-beta regimes of net-current free heliotron plasmas in the Large Helical Device  

Microsoft Academic Search

The performance of net-current free heliotron plasmas has been developed by findings of innovative operational scenarios in conjunction with an upgrade of the heating power and the pumping\\/fuelling capability in the Large Helical Device (LHD). Consequently, the operational regime has been extended, in particular, with regard to high density, long pulse length and high beta. Diversified studies in LHD have

O. Motojima; H. Yamada; A. Komori; N. Ohyabu; T. Mutoh; O. Kaneko; K. Kawahata; T. Mito; K. Ida; S. Imagawa; Y. Nagayama; T. Shimozuma; K. Y. Watanabe; S. Masuzaki; J. Miyazawa; T. Morisaki; S. Morita; S. Ohdachi; N. Ohno; K. Saito; S. Sakakibara; Y. Takeiri; N. Tamura; K. Toi; M. Tokitani; M. Yokoyama; M. Yoshinuma; K. Ikeda; A. Isayama; K. Ishii; S. Kubo; S. Murakami; K. Nagasaki; T. Seki; K. Takahata; H. Takenaga

2007-01-01

330

Evaluation of a Novel Highly Sensitive, Broad-Spectrum PCR-Reverse Hybridization Assay for Detection and Identification of Beta-Papillomavirus DNA  

PubMed Central

Human papillomavirus can be detected by amplification of viral DNA. A novel one-step PCR (PM-PCR) was evaluated for amplification of a 117-bp fragment from the E1 region. It permitted ultrasensitive detection of all 25 known human papillomavirus genotypes from the beta-papillomavirus genus. The intra- and intertypic sequence variations of the 77-bp interprimer region were studied. Genotype-specific probes as well as general probes were selected for the 25 established beta-papillomavirus types, and a reverse hybridization assay (RHA) was developed (PM-PCR RHA method). The analytical sensitivity of the PM-PCR RHA method was 10 to 100 viral genomes. The one-step PM-PCR turned out to be more sensitive than the previously described nested MaHa-PCR for beta-papillomavirus detection. The PM-PCR RHA method was able to detect and identify beta-papillomavirus types in frozen patient material as well as in poorly amplifiable material such as formalin-fixed, paraffin-embedded skin biopsy specimens. Inter- and intralaboratory variability experiments showed that the reproducibility of the assay was very high. In conclusion, the one-step PM-PCR together with the RHA allows extremely sensitive, specific, and reproducible detection of beta-papillomavirus DNA as well as reliable identification of beta-papillomavirus genotypes in both fresh and paraffin-embedded patient material. PMID:16672409

de Koning, Maurits; Quint, Wim; Struijk, Linda; Kleter, Bernhard; Wanningen, Patrick; van Doorn, Leen-Jan; Weissenborn, Sönke Jan; Feltkamp, Mariet; ter Schegget, Jan

2006-01-01

331

Green fluorescent protein/beta-galactosidase double reporters for visualizing Drosophila gene expression patterns.  

PubMed

We characterized 120 novel yeast Ga14-targeted enhancer trap lines in Drosophila using upstream activating sequence (UAS) reporter plasmids incorporating newly constructed fusions of Aequorea victoria green fluorescent protein (GFP) and Escherichia coli beta-galactosidase genes. Direct comparisons of GFP epifluorescence and beta-galactosidase staining revealed that both proteins function comparably to their unconjugated counterparts within a wide variety of Drosophila tissues. Generally, both reporters accumulated in similar patterns within individual lines, but in some tissues, e.g., brain, GFP staining was more reliable than that of beta-galactosidase, whereas in other tissues, most notably tests and ovaries, the converse was true. In cases of weak enhancers, we occasionally could detect beta-galactosidase staining in the absence of discernible GFP fluorescence. This shortcoming of GFP can, in most cases, be alleviated by using the more efficient S65T GFP derivative. The GFP/beta-gal reporter fusion protein facilitated monitoring several aspects of protein accumulation. In particular, the ability to visualize GFP fluorescence enhances recognition of global static and dynamic patterns in live animals, whereas beta-galactosidase histochemistry affords sensitive high resolution protein localization. We present a catalog of Ga 14-expressing strains that will be useful for investigating several aspects of Drosophila melanogaster cell and developmental biology. PMID:9254908

Timmons, L; Becker, J; Barthmaier, P; Fyrberg, C; Shearn, A; Fyrberg, E

1997-01-01

332

5-Aminoimidazole-4-carboxamide-1-beta-D-ribofuranosyl 5'-Monophosphate (AICAR), a Highly Conserved Purine Intermediate with Multiple Effects  

PubMed Central

AICAR (5-Aminoimidazole-4-carboxamide-1-beta-D-ribofuranosyl 5'-monophosphate) is a natural metabolic intermediate of purine biosynthesis that is present in all organisms. In yeast, AICAR plays important regulatory roles under physiological conditions, notably through its direct interactions with transcription factors. In humans, AICAR accumulates in several metabolic diseases, but its contribution to the symptoms has not yet been elucidated. Further, AICAR has highly promising properties which have been recently revealed. Indeed, it enhances endurance of sedentary mice. In addition, it has antiproliferative effects notably by specifically inducing apoptosis of aneuploid cells. Some of the effects of AICAR are due to its ability to stimulate the AMP-activated protein kinase but some others are not. It is consequently clear that AICAR affects multiple targets although only few of them have been identified so far. This review proposes an overview of the field and suggests future directions. PMID:24957512

Daignan-Fornier, Bertrand; Pinson, Benoît

2012-01-01

333

High resolution energy-filtering transmission electron microscopy for equilibrium {beta}-phase in an Al-Mg-Si alloy  

SciTech Connect

High-resolution transmission electron microscopy (HRTEM) has become a popular technique to clarify the precipitation behavior of aluminum alloys. This technique can be used to obtain information on the periodicity of the crystal structure in nano-scaled regions. The chemical composition in such a nano-ordered region is best determined by another method, e.g., energy dispersive X-ray spectroscopy (EDX). However, energy-filtering transmission electron microscopy (EFTEM) succeeds in combining HRTEM and compositional information through electron energy loss spectroscopy (EELS). Recent EFTEM studies have mainly reported on semiconductor device materials. No studies have been reported concerning the crystal structures of precipitates in Al-Mg-Si alloys by EFTEM. This study reports the separation of the lattice images of magnesium and silicon of the equilibrium {beta}-Mg{sub 2}Si phase in an Al-Mg-Si alloy using a new type of 400 kV-EFTEM.

Matsuda, Kenji; Naoi, Tsutomu; Ikeno, Susumu [Toyama Univ. (Japan)] [Toyama Univ. (Japan); Uetani, Yasuhiro [Toyama Prefectural Univ. (Japan). Research Inst. of Tech.] [Toyama Prefectural Univ. (Japan). Research Inst. of Tech.; Sato, Tatsuo; Kamio, Akihiko [Tokyo Inst. of Tech. (Japan)] [Tokyo Inst. of Tech. (Japan)

1999-07-23

334

Influenza Virus-Membrane Fusion Triggered by Proton Uncaging for Single Particle Studies of Fusion Kinetics  

E-print Network

Influenza Virus-Membrane Fusion Triggered by Proton Uncaging for Single Particle Studies of Fusion for studying membrane fusion, focusing on influenza virus fusion to lipid bilayers, which provides high temporal resolution through the rapid and coordinated initiation of individual virus fusion events. Each

Daniel, Susan

335

Ultra-high speed photomultiplier tubes with nanosecond gating for fusion diagnostics  

SciTech Connect

Fusion diagnostics can involve the measurement of ultra-fast optical pulses, often in close temporal proximity. We present a solution for the diagnostics of gamma reaction history and neutron time of flight by using microchannel plate based photomultiplier tubes (PMTs). The time response of the PMTs can be as fast as 100 ps FWHM and with a gain of up to 10{sup 7}. To observe small events in close temporal proximity to much larger signals such as the down-scattered fraction, the response of MCP-PMTs can be gated with an on/off ratio of up to 10{sup 13} in just 2 ns.

Milnes, J. S. [Photek Ltd, 26 Castleham Road, St Leonards on Sea, East Sussex, TN38 9NS (United Kingdom); Horsfield, C. J.; Rubery, M. S. [AWE, Aldermaston, Reading, Berkshire, RG7 4PR (United Kingdom); Glebov, V. Yu. [University of Rochester - Laboratory for Laser Energetics, 250 E. River Road, Rochester, New York 14623 (United States); Herrmann, H. W. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2012-10-15

336

Controlled Nuclear Fusion.  

ERIC Educational Resources Information Center

This publication is one of a series of information booklets for the general public published by The United States Atomic Energy Commission. Among the topics discussed are: Importance of Fusion Energy; Conditions for Nuclear Fusion; Thermonuclear Reactions in Plasmas; Plasma Confinement by Magnetic Fields; Experiments With Plasmas; High-Temperature…

Glasstone, Samuel

337

Bats are able to maintain long-term social relationships despite the high fission-fusion dynamics of their groups.  

PubMed

Elephants, dolphins, as well as some carnivores and primates maintain social links despite their frequent splitting and merging in groups of variable composition, a phenomenon known as fission-fusion. Information on the dynamics of social links and interactions among individuals is of high importance to the understanding of the evolution of animal sociality, including that of humans. However, detailed long-term data on such dynamics in wild mammals with fully known demography and kin structures are scarce. Applying a weighted network analysis on 20,500 individual roosting observations over 5 years, we show that in two wild Bechstein's bat colonies with high fission-fusion dynamics, individuals of different age, size, reproductive status and relatedness maintain long-term social relationships. In the larger colony, we detected two stable subunits, each comprising bats from several family lineages. Links between these subunits were mainly maintained by older bats and persisted over all years. Moreover, we show that the full details of the social structure become apparent only when large datasets are used. The stable multi-level social structures in Bechstein's bat colonies resemble that of elephants, dolphins and some primates. Our findings thus may shed new light on the link between social complexity and social cognition in mammals. PMID:21307051

Kerth, Gerald; Perony, Nicolas; Schweitzer, Frank

2011-09-22

338

Bats are able to maintain long-term social relationships despite the high fission–fusion dynamics of their groups  

PubMed Central

Elephants, dolphins, as well as some carnivores and primates maintain social links despite their frequent splitting and merging in groups of variable composition, a phenomenon known as fission–fusion. Information on the dynamics of social links and interactions among individuals is of high importance to the understanding of the evolution of animal sociality, including that of humans. However, detailed long-term data on such dynamics in wild mammals with fully known demography and kin structures are scarce. Applying a weighted network analysis on 20 500 individual roosting observations over 5 years, we show that in two wild Bechstein's bat colonies with high fission–fusion dynamics, individuals of different age, size, reproductive status and relatedness maintain long-term social relationships. In the larger colony, we detected two stable subunits, each comprising bats from several family lineages. Links between these subunits were mainly maintained by older bats and persisted over all years. Moreover, we show that the full details of the social structure become apparent only when large datasets are used. The stable multi-level social structures in Bechstein's bat colonies resemble that of elephants, dolphins and some primates. Our findings thus may shed new light on the link between social complexity and social cognition in mammals. PMID:21307051

Kerth, Gerald; Perony, Nicolas; Schweitzer, Frank

2011-01-01

339

Direct observation of the intergrown {alpha}-phase in {beta}-TmAlB{sub 4} via high-resolution electron microscopy  

SciTech Connect

A TmAlB{sub 4} crystal with a ThMoB{sub 4}-type ({beta}-type) structure phase related to a hexagonal AlB{sub 2}-type structure was studied by electron diffraction and high-resolution electron microscopy. A high-resolution image clearly exhibits an intergrown lamellar structure of a YCrB{sub 4}-type ({alpha}-type) phase in the matrix of the {beta}-type phase in TmAlB{sub 4} crystal. The lamellar structure can be characterized by a tiling of deformed hexagons, which are a common structure unit in the {alpha}-type and {beta}-type structures. The intergrown nanostructure is considered to be attributed to the origin of low temperature anomalies in physical properties.

Yubuta, Kunio, E-mail: yubuta@imr.tohoku.ac.jp [Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577 (Japan); Mori, Takao [International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba 305-0044 (Japan); Leithe-Jasper, Andreas; Grin, Yuri [Max-Plank-Institut fuer Chemische Physik fester Stoeffe, 01187 Dresden (Germany); Okada, Shigeru [Department of Science and Engineering, Kokushikan University, Tokyo 154-8515 (Japan); Shishido, Toetsu [Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577 (Japan)

2009-08-05

340

Expression of TNF-alpha and TGF-beta 1 in the rat brain after a single high-dose irradiation.  

PubMed Central

Cytokines and growth factors are important regulatory proteins controlling the growth and differentiation of normal and malignant glial cells. In this study, we investigated the expression and origin of tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta 1 (TGF-beta 1) in the subacute brain injury after a single high-dose irradiation using 60 Sprague-Dawley rats. The right cerebral hemispheres of rats were exposed to a single 10 Gy dose of gamma rays using Ir-192. The radiation effect was assessed at 1 week, 2 weeks, 4 weeks, 6 weeks, and 8 weeks after irradiation, and the results were compared with those in sham operation group. Histological changes characteristic of radiation injury were correlated with the duration after the single dose irradiation. The loss of cortical thickness also increased with the lapse of time after irradiation. The TNF-alpha expression in the irradiated cerebral hemispheres was significantly increased compared with that in the sham operation group. TGF-beta 1 expression was also increased in the irradiated hemispheres. Immunohistochemical study revealed that TGF-beta 1 was expressed predominantly by infiltrating macrophages and astrocytes around the necrotic areas. These findings indicate that TNF-alpha and TGF-beta 1 may play prominent roles in the radiation injuries after a single high-dose irradiation. PMID:11961311

Kim, Se-Hoon; Lim, Dong-Jun; Chung, Yong-Gu; Cho, Tai-Hyoung; Lim, Seong-Jun; Kim, Woo-Jae; Suh, Jung-Keun

2002-01-01

341

An EGFR/HER2-Bispecific and Enediyne-Energized Fusion Protein Shows High Efficacy against Esophageal Cancer  

PubMed Central

Esophageal cancer is one of the most common cancers, and the 5-year survival rate is less than 10% due to lack of effective therapeutic agents. This study was to evaluate antitumor activity of Ec-LDP-Hr-AE, a recently developed bispecific enediyne-energized fusion protein targeting both epidermal growth factor receptor (EGFR) and epidermal growth factor receptor 2 (HER2), on esophageal cancer. The fusion protein Ec-LDP-Hr-AE consists of two oligopeptide ligands and an enediyne antibiotic lidamycin (LDM) for receptor binding and cell killing, respectively. The current study demonstrated that Ec-LDP-Hr had high affinity to bind to esophageal squamous cell carcinoma (ESCC) cells, and enediyne-energized fusion protein Ec-LDP-Hr-AE showed potent cytotoxicity to ESCC cells with differential expression of EGFR and HER2. Ec-LDP-Hr-AE could cause significant G2-M arrest in EC9706 and KYSE150 cells, and it also induced apoptosis in ESCC cells in a dosage-dependent manner. Western blot assays showed that Ec-LDP-Hr-AE promoted caspase-3 and caspase-7 activities as well as PARP cleavage. Moreover, Ec-LDP-Hr-AE inhibited cell proliferation via decreasing phosphorylation of EGFR and HER2, and further exerted inhibition of the activation of their downstream signaling molecules. In vivo, at a tolerated dose, Ec-LDP-Hr-AE inhibited tumor growth by 88% when it was administered to nude mice bearing human ESCC cell KYSE150 xenografts. These results indicated that Ec-LDP-Hr-AE exhibited potent anti-caner efficacy on ESCC, suggesting it could be a promising candidate for targeted therapy of esophageal cancer. PMID:24664246

Yang, Wan-Cai; Zhang, Sheng-Hua; Zhen, Yong-Su

2014-01-01

342

Hard x-ray backlighters for high resolution Compton radiography of Inertial Confinement Fusion targets  

NASA Astrophysics Data System (ADS)

Radiographs of the final stages of imploding DT fuel in inertial confinement fusion experiments will be extremely valuable for checking the convergence, areal density and areal density uniformity of the fuel. For x-rays with energies between 30 and 200 keV, the main opacity will be due to Compton scattering. Here we present the demonstration of 75-200 keV point backlighter sources generated by gold targets irradiated by picosecond laser pulses. In experiments performed at the Titan laser facility at Lawrence Livermore National Laboratory, we measured the source size and the Bremsstrahlung spectrum, as a function of laser intensity and pulse length, from by 5e17-5e18 W/cm^2 using 2-40 ps pulses. We achieved 1D and 2D source sizes of 10 ?m, and conversion efficiencies exceeding 1e-3 J/J into x-ray photons with energies in the 100-200 keV spectral range. These sources meet the requirements for radiographing the fuel in inertial confinement fusion implosions at both OMEGA and the National Ignition Facility (NIF) whose experimental designs will also be discussed.

Tommasini, R.; Macphee, A.; Hey, D.; Ma, T.; Chen, C.; Izumi, N.; MacKinnon, A.; Hatchett, S. P.; Koch, J. A.; Springer, P.; Landen, O. L.

2008-11-01

343

Development of high-power solid state laser for inertial fusion energy driver  

NASA Astrophysics Data System (ADS)

The design study of the laser fusion power plant KOYO has been conducted as a joint program of universities, national laboratories, and industries in Japan and also with international collaborations. In the design of KOYO, the gain scaling of direct drive implosion with 0.35 micrometers wavelength laser light is used. A driver of diode pumped solid state laser generates 4 MJ/pulse with 12 Hz and the output pulses are switched to deliver the laser energy success five to four chambers, which operate with 3 Hz. The chamber wall is protected with thick liquid metal which flows down in a SiC woven tube. Following to the conceptual design study, the critical key issues which may affect the technical and economical and economical feasibility of the commercial power plant KOYO have been examined. Research and development of some key technologies have been performed. As the results of the studies on KOYO, it is concluded that thee technical and economical feasibility of laser fusion reactor is well in our scope to reach.

Yoshida, Kunio; Yamanaka, Masanobu; Nakatsuka, Masahiro; Sasaki, Takatomo; Nakai, Sadao

1997-05-01

344

A faster, high resolution, mtPA-GFP-based mitochondrial fusion assay acquiring kinetic data of multiple cells in parallel using confocal microscopy.  

PubMed

Mitochondrial fusion plays an essential role in mitochondrial calcium homeostasis, bioenergetics, autophagy and quality control. Fusion is quantified in living cells by photo-conversion of matrix targeted photoactivatable GFP (mtPAGFP) in a subset of mitochondria. The rate at which the photoconverted molecules equilibrate across the entire mitochondrial population is used as a measure of fusion activity. Thus far measurements were performed using a single cell time lapse approach, quantifying the equilibration in one cell over an hour. Here, we scale up and automate a previously published live cell method based on using mtPAGFP and a low concentration of TMRE (15 nm). This method involves photoactivating a small portion of the mitochondrial network, collecting highly resolved stacks of confocal sections every 15 min for 1 hour, and quantifying the change in signal intensity. Depending on several factors such as ease of finding PAGFP expressing cells, and the signal of the photoactivated regions, it is possible to collect around 10 cells within the 15 min intervals. This provides a significant improvement in the time efficiency of this assay while maintaining the highly resolved subcellular quantification as well as the kinetic parameters necessary to capture the detail of mitochondrial behavior in its native cytoarchitectural environment. Mitochondrial dynamics play a role in many cellular processes including respiration, calcium regulation, and apoptosis. The structure of the mitochondrial network affects the function of mitochondria, and the way they interact with the rest of the cell. Undergoing constant division and fusion, mitochondrial networks attain various shapes ranging from highly fused networks, to being more fragmented. Interestingly, Alzheimer's disease, Parkinson's disease, Charcot Marie Tooth 2A, and dominant optic atrophy have been correlated with altered mitochondrial morphology, namely fragmented networks. Often times, upon fragmentation, mitochondria become depolarized, and upon accumulation this leads to impaired cell function. Mitochondrial fission has been shown to signal a cell to progress toward apoptosis. It can also provide a mechanism by which to separate depolarized and inactive mitochondria to keep the bulk of the network robust. Fusion of mitochondria, on the other hand, leads to sharing of matrix proteins, solutes, mtDNA and the electrochemical gradient, and also seems to prevent progression to apoptosis. How fission and fusion of mitochondria affects cell homeostasis and ultimately the functioning of the organism needs further understanding, and therefore the continuous development and optimization of how to gather information on these phenomena is necessary. Existing mitochondrial fusion assays have revealed various insights into mitochondrial physiology, each having its own advantages. The hybrid PEG fusion assay, mixes two populations of differently labeled cells (mtRFP and mtYFP), and analyzes the amount of mixing and colocalization of fluorophores in fused, multinucleated, cells. Although this method has yielded valuable information, not all cell types can fuse, and the conditions under which fusion is stimulated involves the use of toxic drugs that likely affect the normal fusion process. More recently, a cell free technique has been devised, using isolated mitochondria to observe fusion events based on a luciferase assay. Two human cell lines are targeted with either the amino or a carboxy terminal part of Renilla luciferase along with a leucine zipper to ensure dimerization upon mixing. Mitochondria are isolated from each cell line, and fused. The fusion reaction can occur without the cytosol under physiological conditions in the presence of energy, appropriate temperature and inner mitochondrial membrane potential. Interestingly, the cytosol was found to modulate the extent of fusion, demonstrating that cell signaling regulates the fusion process. This assay will be very useful for high throughput screening to identify components of the fusion machinery and also pharmacological c

Lovy, Alenka; Molina, Anthony J A; Cerqueira, Fernanda M; Trudeau, Kyle; Shirihai, Orian S

2012-01-01

345

A Faster, High Resolution, mtPA-GFP-based Mitochondrial Fusion Assay Acquiring Kinetic Data of Multiple Cells in Parallel Using Confocal Microscopy  

PubMed Central

Mitochondrial fusion plays an essential role in mitochondrial calcium homeostasis, bioenergetics, autophagy and quality control. Fusion is quantified in living cells by photo-conversion of matrix targeted photoactivatable GFP (mtPAGFP) in a subset of mitochondria. The rate at which the photoconverted molecules equilibrate across the entire mitochondrial population is used as a measure of fusion activity. Thus far measurements were performed using a single cell time lapse approach, quantifying the equilibration in one cell over an hour. Here, we scale up and automate a previously published live cell method based on using mtPAGFP and a low concentration of TMRE (15 nm). This method involves photoactivating a small portion of the mitochondrial network, collecting highly resolved stacks of confocal sections every 15 min for 1 hour, and quantifying the change in signal intensity. Depending on several factors such as ease of finding PAGFP expressing cells, and the signal of the photoactivated regions, it is possible to collect around 10 cells within the 15 min intervals. This provides a significant improvement in the time efficiency of this assay while maintaining the highly resolved subcellular quantification as well as the kinetic parameters necessary to capture the detail of mitochondrial behavior in its native cytoarchitectural environment. Mitochondrial dynamics play a role in many cellular processes including respiration, calcium regulation, and apoptosis1,2,3,13. The structure of the mitochondrial network affects the function of mitochondria, and the way they interact with the rest of the cell. Undergoing constant division and fusion, mitochondrial networks attain various shapes ranging from highly fused networks, to being more fragmented. Interestingly, Alzheimer's disease, Parkinson's disease, Charcot Marie Tooth 2A, and dominant optic atrophy have been correlated with altered mitochondrial morphology, namely fragmented networks4,10,13. Often times, upon fragmentation, mitochondria become depolarized, and upon accumulation this leads to impaired cell function18. Mitochondrial fission has been shown to signal a cell to progress toward apoptosis. It can also provide a mechanism by which to separate depolarized and inactive mitochondria to keep the bulk of the network robust14. Fusion of mitochondria, on the other hand, leads to sharing of matrix proteins, solutes, mtDNA and the electrochemical gradient, and also seems to prevent progression to apoptosis9. How fission and fusion of mitochondria affects cell homeostasis and ultimately the functioning of the organism needs further understanding, and therefore the continuous development and optimization of how to gather information on these phenomena is necessary. Existing mitochondrial fusion assays have revealed various insights into mitochondrial physiology, each having its own advantages. The hybrid PEG fusion assay7, mixes two populations of differently labeled cells (mtRFP and mtYFP), and analyzes the amount of mixing and colocalization of fluorophores in fused, multinucleated, cells. Although this method has yielded valuable information, not all cell types can fuse, and the conditions under which fusion is stimulated involves the use of toxic drugs that likely affect the normal fusion process. More recently, a cell free technique has been devised, using isolated mitochondria to observe fusion events based on a luciferase assay1,5. Two human cell lines are targeted with either the amino or a carboxy terminal part of Renilla luciferase along with a leucine zipper to ensure dimerization upon mixing. Mitochondria are isolated from each cell line, and fused. The fusion reaction can occur without the cytosol under physiological conditions in the presence of energy, appropriate temperature and inner mitochondrial membrane potential. Interestingly, the cytosol was found to modulate the extent of fusion, demonstrating that cell signaling regulates the fusion process 4,5. This assay will be very useful for high throughput screening to identify components of the fusion machiner

Lovy, Alenka; Molina, Anthony J.A.; Cerqueira, Fernanda M.; Trudeau, Kyle; Shirihai, Orian S.

2012-01-01

346

Recent technologic developments on high-resolution beta imaging systems for quantitative autoradiography and double labeling applications  

Microsoft Academic Search

Two novel beta imaging systems, particularly interesting in the field of radiopharmacology and molecular biology research, were developed these last years. (1) a beta imager was derived from research conducted by Pr Charpak at CERN. This parallel plate avalanche chamber is a direct detection system of ? radioactivity, which is particularly adapted for qualitative and quantitative autoradiography. With this detector,

N. Barthe; K. Chatti; P. Coulon; B. Basse-Cathalinat

2004-01-01

347

High-level expression, purification and study of bioactivity of fusion protein M-IL-2((88)Arg, (125)Ala) in Pichia pastoris.  

PubMed

M-IL-2((88)Arg, (125)Ala) is a fusion protein comprising melittin genetically linked to a mutant human interleukin 2((88)Arg, (125)Ala). In this study, we constructed an expression system of M-IL-2((88)Arg, (125)Ala) in Pichia pastoris: GS115/pPICZ? A/M-IL-2((88)Arg, (125)Ala), and achieved the high-level expression of the fusion protein. The maximum yield of the fusion protein M-IL-2((88)Arg, (125)Ala) reached up to 814.5mg/L, higher than the system in Escherichiacoli. The fusion protein was purified by means of ammonium sulfate fractionation, dialysis and nickel ion affinity chromatography. The molecular weight of the fusion protein is about 26kDa, conforming the theoretical value. And M-IL-2((88)Arg, (125)Ala) possesses strong antigen-specificity by Western blot detection. Bioassay results indicated that the fusion protein could directly inhibit the growth of human ovarian cancer SKOV3 cells and Hela cells in vitro. This study provides an alternative strategy for large-scale production of bioactive M-IL-2((88)Arg, (125)Ala) using P. pastoris as an expression host and paves the way to clinical practice. PMID:24955549

Li, Lin; Qian, Dongmeng; Shao, Guangcan; Yan, Zhiyong; Li, Ronggui; Hua, Xiaomin; Song, Xuxia; Wang, Bin

2014-09-01

348

Fusion excitation function revisited  

E-print Network

We report on a comprehensive systematics of fusion-evaporation and/or fusion-fission cross sections for a very large variety of systems over an energy range 4-155 A.MeV. Scaled by the reaction cross sections, fusion cross sections do not show a universal behavior valid for all systems although a high degree of correlation is present when data are ordered by the system mass asymmetry.For the rather light and close to mass-symmetric systems the main characteristics of the complete and incomplete fusion excitation functions can be precisely determined. Despite an evident lack of data above 15A.MeV for all heavy systems the available data suggests that geometrical effects could explain the persistence of incomplete fusion at incident energies as high as 155A.MeV.

Ph. Eudes; Z. Basrak; F. Sébille; V. de la Mota; G. Royer; M. Zori?

2012-09-28

349

Fusion of surface relief data with high spectral and spatial resolution satellite remote sensor data for deciphering geological information in a mature topographic terrain  

Microsoft Academic Search

For deciphering a greater amount of geological information from satellite remote sensor data, high spectral resolution ‘multi-spectral optical’ remote sensor data and high spatial resolution ‘panchromatic optical’ or ‘radar microwave’ remote sensor data are conventionally merged by data fusion. In a mature topographic terrain, topographic expression, i.e. variation in surface relief over the area, plays an important role in reflecting

R. S. Chatterjee; B. Prabakaran; V. K. Jha

2003-01-01

350

Proceedings of US/Japan workshop, Q219 on high heat flux components and plasma surface interactions for next fusion devices  

SciTech Connect

This report contains the viewgraphs from the proceedings of US/Japan Workshop on High Heat Flux Components and Plasma Surface Interactions for Next Fusion Devices. Some of the general topics covered by this report are: PFC/PSI in tokamak and helical devices; development of high heat flux components; PSIS and plasma facing materials;tritium; and material damage.

Ulrickson, M.A.; Stevens, P.L.; Hino, T.; Hirohata, Y. [eds.] [eds.

1996-12-01

351

Fusion of Kinect depth data with trifocal disparity estimation for near real-time high quality depth maps generation  

NASA Astrophysics Data System (ADS)

Generating depth maps along with video streams is valuable for Cinema and Television production. Thanks to the improvements of depth acquisition systems, the challenge of fusion between depth sensing and disparity estimation is widely investigated in computer vision. This paper presents a new framework for generating depth maps from a rig made of a professional camera with two satellite cameras and a Kinect device. A new disparity-based calibration method is proposed so that registered Kinect depth samples become perfectly consistent with disparities estimated between rectified views. Also, a new hierarchical fusion approach is proposed for combining on the flow depth sensing and disparity estimation in order to circumvent their respective weaknesses. Depth is determined by minimizing a global energy criterion that takes into account the matching reliability and the consistency with the Kinect input. Thus generated depth maps are relevant both in uniform and textured areas, without holes due to occlusions or structured light shadows. Our GPU implementation reaches 20fps for generating quarter-pel accurate HD720p depth maps along with main view, which is close to real-time performances for video applications. The estimated depth is high quality and suitable for 3D reconstruction or virtual view synthesis.

Boisson, Guillaume; Kerbiriou, Paul; Drazic, Valter; Bureller, Olivier; Sabater, Neus; Schubert, Arno

2014-03-01

352

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

E-print Network

The National Ignition Facility (NIF) currently under construction at the University of California Lawrence Livermore National Laboratory (LLNL) is a 192-beam, 1.8-megajoule, 500-terawatt, 351-nm laser for inertial confinement fusion (ICF) and high-energy-density experimental studies. NIF is being built by the Department of Energy and the National Nuclear Security Agency (NNSA) to provide an experimental test bed for the U.S. Stockpile Stewardship Program to ensure the country's nuclear deterrent without underground nuclear testing. The experimental program 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% will be dedicated to basic science research. Laser hardware is modularized into line replaceable units (LRUs) such as deformable mirrors, amplifiers, and multi-function sensor packages that are operated by a distributed computer control system of nearly 60,000 control points. The supervisory control room presents facility-wide status and orchestrates experiments using operating parameters predicted by physics models. A network of several hundred front-end processors (FEPs) implements device control. The object-oriented software system is implemented in the Ada and Java languages and emphasizes CORBA distribution of reusable software objects. NIF is currently scheduled to provide first light in 2004 and will be completed in 2008.

E. I. Moses

2001-11-09

353

Pulsed Operation of a Compact Fusion Neutron Source Using a High-Voltage Pulse Generator Developed for Landmine Detection  

SciTech Connect

Preliminary experimental results of pulsed neutron source based on a discharge-type beam fusion called Inertial Electrostatic Confinement Fusion (IECF) for landmine detection are presented. In Japan, a research and development project for constructing an advanced anti-personnel landmine detection system by using IECF, which is effective not only for metal landmines but also for plastic ones, is now in progress. This project consists of some R and D topics, and one of them is R and D of a high-voltage pulse generator system specialized for landmine detection, which can be used in the severe environment such as that in the field in Afghanistan. Thus a prototype of the system for landmine detection was designed and fabricated in consideration of compactness, lightness, cooling performance, dustproof and robustness. By using this prototype pulse generator system, a conventional IECF device was operated as a preliminary experiment. As a result, it was confirmed that the suggested pulse generator system is suitable for landmine detection system, and the results follow the empirical law obtained by the previous experiments. The maximum neutron production rate of 2.0x10{sup 8} n/s was obtained at a pulsed discharge of -51 kV, 7.3 A.

Yamauchi, Kunihito [Tokyo Institute of Technology (Japan); Watanabe, Masato [Tokyo Institute of Technology (Japan); Okino, Akitoshi [Tokyo Institute of Technology (Japan); Kohno, Toshiyuki [Tokyo Institute of Technology (Japan); Hotta, Eiki [Tokyo Institute of Technology (Japan); Yuura, Morimasa [Pulse Electronic Engineering Co., Ltd. (Japan)

2005-05-15

354

Maltose-Binding Protein Fusion Allows for High Level Bacterial Expression and Purification of Bioactive Mammalian Cytokine Derivatives  

PubMed Central

Fusokines are chimeric proteins generated by the physical coupling of cytokines in a single polypeptide, resulting in proteins with highly pleiotropic activity and the potential to treat cancer and autoimmune ailments. For instance, the fusokine GIFT15 (GM-CSF and Interleukin 15 Fusion Transgene) has been shown to be a powerful immunosuppressive protein able to convert naïve B cells into IL-10-producing B cells. To date, the mammalian cell systems used for the expression of GIFT15 allow for secretion of the protein in the culturing media, an inefficient system for producing GMP-compliant fusokines. In this study we report the bacterial expression of bioactive recombinant GIFT15 (rGIFT15). Indeed, there is a constant demand to improve the expression systems for therapeutic proteins. Expression of a maltose-binding protein (MBP) fusion protein efficiently allowed the accumulation of soluble protein in the intracellular milieu. Optimizing the bacterial culture significantly increased the yield of recombinant protein. The biological activity of rGIFT15 was comparable to that of fusokine derived from a mammalian source. This approach led to the production of soluble, endotoxin-free functional protein, averaging 5 mg of rGIFT15 per liter of culture. This process is amenable to scale up for the development of Food and Drug Administration (FDA)-compliant immune-modulatory rGIFT15. PMID:25198691

Pennati, Andrea; Deng, Jiusheng; Galipeau, Jacques

2014-01-01

355

Task toward a Realization of Commercial Tokamak Fusion Plants in 2050 -The Role of ITER and the Succeeding Developments- 5.Challenge to Innovative Technologies and the Expected Market Appeal  

NASA Astrophysics Data System (ADS)

This section describes the future of fusion energy in terms of its impact on the global energy supply and global warming mitigation, the possible entry scenarios of fusion into future energy market, and innovative technologies for deploying and expanding fusion's share in the market. Section 5.1 shows that fusion energy can contribute to the stabilization of atmospheric CO2 concentration if fusion is introduced into the future energy market at a competitive price. Considerations regarding fusion's entry scenarios into the energy market are presented in Sec. 5.2, suggesting that fusion should replace fossil energy sources and thus contribute to global warming mitigation. In this sense, first generation fusion power plants should be a viable energy source with global appeal and be so attractive as to be employed in developing countries rather than in developed countries. Favorable factors lending to this purpose are fusion's stability as a power source, and its security, safety, and environmental frendliness as well as its cost-of-electricity. The requirements for core plasma to expand the share of fusion in the market in the latter half of this century are given in Sec.5.3, pointing out the importance of high beta access with low aspect ratio and plasma profile control. From this same point of view, innovative fusion technologies worthy of further development are commented on in Sec. 5.4, addressing the high temperature blanket, hydrogen production, high temperature superconductors, and hot cell maintenance.

Tobita, Kenji; Konishi, Satoshi; Tokimatsu, Koji; Nishio, Satoshi; Hiwatari, Ryoji

356

Highly selective and sensitive colorimetric probes for Yb3+ ions based on supramolecular aggregates assembled from beta-cyclodextrin-4,4'-dipyridine inclusion complex modified silver nanoparticles.  

PubMed

Novel beta-cyclodextrin-4,4'-dipyridine supramolecular inclusion complex-modified silver nanoparticles were synthesized for the colorimetric determination of Yb(3+) ions in aqueous solution with high sensitivity (the visual detection limit was 2 x 10(-7) M), via Yb(3+)-induced aggregation to form chain-like supramolecular aggregates. PMID:19521602

Han, Cuiping; Zhang, Liang; Li, Haibing

2009-06-28

357

Highly precise Re-Os dating for molybdenite using alkaline fusion and NTIMS  

USGS Publications Warehouse

The technique described in this paper represents the modification and combination of two previously existing methods, alkaline fusion and negative thermal ion mass spectrometry (NTIMS). We have used this technique to analyze repeatedly a homogeneous molybdenite powder used as a reference standard in our laboratory. Analyses were made over a period of 18 months, using four different calibrations of two different spike solutions. The age of this standard reproduces at a level of ?? 0.13%. Each individual age analysis carries an uncertainty of about 0.4% that includes the uncertainty in the decay constant for 187Re. This new level of resolution has allowed us to recognize real differences in ages for two grain-size populations of molybdenite from some Archean samples.

Markey, R.; Stein, H.; Morgan, J.

1998-01-01

358

Vacuum insulation of the high energy negative ion source for fusion application  

SciTech Connect

Vacuum insulation on a large size negative ion accelerator with multiple extraction apertures and acceleration grids for fusion application was experimentally examined and designed. In the experiment, vacuum insulation characteristics were investigated in the JT-60 negative ion source with >1000 apertures on the grid with the surface area of {approx}2 m{sup 2}. The sustainable voltages varied with a square root of the gap lengths between the grids, and decreased with number of the apertures and with the surface area of the grids. Based on the obtained results, the JT-60SA (super advanced) negative ion source is designed to produce 22 A, 500 keV D{sup -} ion beams for 100 s.

Kojima, A.; Hanada, M.; Inoue, T.; Watanabe, K.; Taniguchi, M.; Kashiwagi, M.; Umeda, N.; Tobari, H. [Japan Atomic Energy Agency, Naka, Ibaraki 311-0193 (Japan); Hilmi, A.; Kobayashi, S.; Yamano, Y. [Saitama University, Saitama, Saitama-ken, 338-8570 (Japan); Grisham, L. R. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

2012-02-15

359

Symmetric Inertial Confinement Fusion Implosions at Ultra-High Laser Energies  

NASA Astrophysics Data System (ADS)

Indirect-drive hohlraum experiments at the National Ignition Facility have demonstrated symmetric capsule implosions at unprecedented laser drive energies of 0.7 megajoule. One hundred and ninety-two simultaneously fired laser beams heat ignition-emulate hohlraums to radiation temperatures of 3.3 million kelvin, compressing 1.8-millimeter-diameter capsules by the soft x-rays produced by the hohlraum. Self-generated plasma optics gratings on either end of the hohlraum tune the laser power distribution in the hohlraum, which produces a symmetric x-ray drive as inferred from the shape of the capsule self-emission. These experiments indicate that the conditions are suitable for compressing deuterium-tritium-filled capsules, with the goal of achieving burning fusion plasmas and energy gain in the laboratory.

Glenzer, S. H.; MacGowan, B. J.; Michel, P.; Meezan, N. B.; Suter, L. J.; Dixit, S. N.; Kline, J. L.; Kyrala, G. A.; Bradley, D. K.; Callahan, D. A.; Dewald, E. L.; Divol, L.; Dzenitis, E.; Edwards, M. J.; Hamza, A. V.; Haynam, C. A.; Hinkel, D. E.; Kalantar, D. H.; Kilkenny, J. D.; Landen, O. L.; Lindl, J. D.; LePape, S.; Moody, J. D.; Nikroo, A.; Parham, T.; Schneider, M. B.; Town, R. P. J.; Wegner, P.; Widmann, K.; Whitman, P.; Young, B. K. F.; Van Wonterghem, B.; Atherton, L. J.; Moses, E. I.

2010-03-01

360

Application of railgun principle to high-velocity hydrogen pellet injection for magnetic fusion reactor refueling  

SciTech Connect

This report contains three documents describing the progress made by the University of Illinois electromagnetic railgun program sponsored by the Office of Fusion Energy of the United States Department of Energy during the period from July 16, 1990 to August 16, 1991. The first document contains a brief summary of the tasks initiated, continued, or completed, the status of major tasks, and the research effort distribution, estimated and actual, during the period. The second document contains a description of the work performed on time resolved laser interferometric density measurement of the railgun plasma-arc armature. The third document is an account of research on the spectroscopic measurement of the electron density and temperature of the railgun plasma arc.

Kim, K.

1991-08-01

361

Symmetric inertial confinement fusion implosions at ultra-high laser energies.  

PubMed

Indirect-drive hohlraum experiments at the National Ignition Facility have demonstrated symmetric capsule implosions at unprecedented laser drive energies of 0.7 megajoule. One hundred and ninety-two simultaneously fired laser beams heat ignition-emulate hohlraums to radiation temperatures of 3.3 million kelvin, compressing 1.8-millimeter-diameter capsules by the soft x-rays produced by the hohlraum. Self-generated plasma optics gratings on either end of the hohlraum tune the laser power distribution in the hohlraum, which produces a symmetric x-ray drive as inferred from the shape of the capsule self-emission. These experiments indicate that the conditions are suitable for compressing deuterium-tritium-filled capsules, with the goal of achieving burning fusion plasmas and energy gain in the laboratory. PMID:20110465

Glenzer, S H; MacGowan, B J; Michel, P; Meezan, N B; Suter, L J; Dixit, S N; Kline, J L; Kyrala, G A; Bradley, D K; Callahan, D A; Dewald, E L; Divol, L; Dzenitis, E; Edwards, M J; Hamza, A V; Haynam, C A; Hinkel, D E; Kalantar, D H; Kilkenny, J D; Landen, O L; Lindl, J D; LePape, S; Moody, J D; Nikroo, A; Parham, T; Schneider, M B; Town, R P J; Wegner, P; Widmann, K; Whitman, P; Young, B K F; Van Wonterghem, B; Atherton, L J; Moses, E I

2010-03-01

362

High Resolution Neutron Imaging of Inertial Fusion Targets Using Bubble Detectors  

NASA Astrophysics Data System (ADS)

Neutron imaging of inertial fusion plasmas provides a direct measurement of the spatial location and extent of the fusion reactions and will be one of the most useful diagnostics during the early ignition studies on the National Ignition Facility. Images of the burning fuel can verify calculations of implosion physics, determine the existence of asymmetries, and allow rapid evaluation of target performance. Previous neutron imaging experiments have used scintillation detector arrays and penumbral imaging, conceptually similar to pinhole imaging except that the aperture diameter is larger than the neutron source. The geometrical limit for spatial resolution in the target plane is given by the detector resolution divided by the system magnification. It will be extremely difficult to image targets with the 5 micron resolution needed in NIF experiments using plastic scintillators, which have a resolution limited by the ? 500 500 micron range of the recoil deuteron and would require the detectors be 100 m or more from the target. Bubble detectors can potentially detect neutrons with a spatial resolution as small as 5 microns, or approximately two orders of magnitude better than the resolution in scintillation detectors. We report the results of proof-of-principle neutron imaging experiments on OMEGA. The results demonstrate that bubble detectors should revolutionize the design of penumbral and other coded aperture imaging systems. Prospects for imaging target plasmas in NIF with 5 micron spatial resolution in the target plane appear excellent. ^In collaboration with R.A. Lerche, N. Izumi, T.C. Sangster (LLNL); L. Disdier, J.L. Bourgade, A. Rouyer (CEA-France); P.A. Jaanimagi (UR-LLE), and R.B. Stephens (GA).

Fisher, R. K.

2001-10-01

363

Separation of enzymes from polyenzyme mixture used in medicine and pharmacy. II. Purification and characterization of extracellular beta-glycosidases with high transglycosylation activities from Aspergillus oryzae.  

PubMed

Three extracellular beta-glycosidases with different substrate specificities have been isolated from Aspergillus oryzae (Luizym) and purified to electrophoretic homogeneity by molecular-sieve and ion-exchange chromatographic methods. The enzymes were characterized as monomeric glycoproteins with an estimated molecular mass of 95 kDa by SDS-PAGE and 92 kDa by gel-permeation chromatography on Superose 12 HR 10/30. beta-glycosidase I (pHopt 4.8; Topt 40 degrees C, pl 4.5) was able to catalyze the hydrolysis of aryl-beta-galactopyranosides (o- and p-), where as gamma-glycosidase II and III were found to be active towards aryl-beta-gluco- and xylopyranosides. The specific chemical modifications of different amino acid residues showed that tryptophyl and carboxyl residues play an important role for the enzyme activity. The isolated beta-glycosidases exhibited high levels of transglycosylation activities and were used for the production of tri- and tetrasaccharides from lactose and whey permeate. PMID:12622257

Petrova, S D; Bakalova, N G; Bankova, E D; Andonova, S B; Kolev, D N

2003-01-01

364

[Simultaneous determination of three beta-lactamase inhibitor residues in dairy products by high performance liquid chromatography].  

PubMed

An improved method has been developed for the determination of clavulanate potassium, tazobactam and sulbactam in dairy products. High performance liquid chromatography with photodiode array detector (HPLC-PAD) was used in this method. The separation was performed on a CAPCELL PAK MG-C18 column (150 mm x 4.6 mm, 5 microm). The mobile phase was 0.03% (volume fraction unless otherwise specified) phosphate-acetonitrile. This method offered effective sample preparation procedures including dissolution with water, protein isolation with acetone, clean-up and enrichment by solid-phase extraction (SPE) with PWAX cartridges (60 mg/3 mL) under weak acidic condition and further elution with 0.05% ammonia-methanol solution. The analytical method was well validated and good results were obtained with the RSDs of 2.2% - 7.4% and the recoveries of 84.6% - 101.7%. The detection limits of clavulanate potassium, tazobactam and sulbactam were 0.03 mg/L. All of the target compounds exhibited good linearities (r > 0.999) over the mass concentration range of 0.05 - 5 mg/L. With the advantages of good purification effect, high sensitivity, good recovery and repeatability, the method is suitable for the detection of beta-lactamase inhibitors in dairy products. PMID:24010343

Lin, Qin

2013-05-01

365

Application of beta-galactosidase enzyme complementation technology as a high throughput screening format for antagonists of the epidermal growth factor receptor.  

PubMed

We have applied enzyme complementation technology to develop a screen for antagonists of the epidermal growth factor (EGF) receptor. Chimeric proteins containing two weakly complementing deletion mutants of Escherichia coli beta-galactosidase (beta-gal), each fused to the EGF receptor extracellular and transmembrane domains, have been stably expressed in C2C12 cells. In this cell line, formation of active beta-gal is dependent on agonist-stimulated dimerization of the EGF receptor. We have developed a homogenous 384-well assay protocol and have applied this to characterize the pharmacology of the receptor and to develop a high throughput screen (HTS) for EGF receptor antagonists. The assay is tolerant to DMSO concentrations of up to 2% and, across 21 passages in culture, exhibits an EC(50) for EGF of 5.4 +/- 3.6 ng/ml (n = 11) and a Z' of 0.55 +/- 0.13 (n = 11). A random set of 1,280 compounds was screened in duplicate at 11 microM to examine the robustness of enzyme complementation technology and to characterize the false-positive hit rate in the assay. Using a cutoff of 40% inhibition of EGF-promoted beta-gal activity, the hit rate on day 1 was 2.5% and on day 2 was 1.9%. After retesting the active compounds, the hit rate was reduced to 0.4%, of which one of the compounds was identified as a beta-gal inhibitor and the remainder appeared to be nonspecific inhibitors in the assay. This technology is amenable to automated screen workstations, there are highly sensitive chemiluminescent and fluorescent beta-gal assay reagents amenable to detection in miniaturized plate formats, and the assay benefits from a low false-positive hit rate. Enzyme complementation technology may have wide application within the HTS environment for the detection of modulators of receptor activation or inhibitors of protein-protein interactions in mammalian cells. PMID:11788058

Graham, D L; Bevan, N; Lowe, P N; Palmer, M; Rees, S

2001-12-01

366

Characterization of the mouse islet-specific glucose-6-phosphatase catalytic subunit-related protein gene promoter by in situ footprinting: correlation with fusion gene expression in the islet-derived betaTC-3 and hamster insulinoma tumor cell lines.  

PubMed

Glucose-6-phosphatase (G6Pase) is a multicomponent system located in the endoplasmic reticulum comprising a catalytic subunit and transporters for glucose-6-phosphate, inorganic phosphate, and glucose. We have recently cloned a novel gene that encodes an islet-specific G6Pase catalytic subunit-related protein (IGRP) (Ebert et al., Diabetes 48:543-551, 1999). To begin to investigate the molecular basis for the islet-specific expression of the IGRP gene, a series of truncated IGRP-chloramphenicol acetyltransferase (CAT) fusion genes were transiently transfected into the islet-derived mouse betaTC-3 and hamster insulinoma tumor cell lines. In both cell lines, basal fusion gene expression decreased upon progressive deletion of the IGRP promoter sequence between -306 and -66, indicating that multiple promoter regions are required for maximal IGRP-CAT expression. The ligation-mediated polymerase chain reaction footprinting technique was then used to compare trans-acting factor binding to the IGRP promoter in situ in betaTC-3 cells, which express the endogenous IGRP gene, and adrenocortical Y1 cells, which do not. Multiple trans-acting factor binding sites were selectively identified in betaTC-3 cells that correlate with regions of the IGRP promoter identified as being required for basal IGRP-CAT fusion gene expression. The data suggest that hepatocyte nuclear factor 3 may be important for basal IGRP gene expression, as it is for glucagon, GLUT2, and Pdx-1 gene expression. In addition, binding sites for several trans-acting factors not previously associated with islet gene expression, as well as binding sites for potentially novel proteins, were identified. PMID:11246869

Bischof, L J; Martin, C C; Svitek, C A; Stadelmaier, B T; Hornbuckle, L A; Goldman, J K; Oeser, J K; Hutton, J C; O'Brien, R M

2001-03-01

367

Effect of inner conductor misalignment of high-$\\beta$ quarter-wave resonator  

E-print Network

Niobium sputtering the HIE-ISOLDE quarter-wave resonator at high temperatures has called for a reconsideration of the mechanical tolerances for the fabrication of the cavity. A study was launched to understand the effect of inner conductor misalignments on the beam to determine the manufacturing tolerances; in previous error studies only misalignments of the ideal cavity were considered. Systematic rf simulations of the imperfect cavity were carried out using CST Microwave Studio and kick factors calculated for each mode of misalignment. It was found, as expected, that the misalignments of the internal conductor give the same order of magnitude kick as misalignments of the entire ideal cavity. To avoid any significant perturbation to the beam, the inner conductor should be aligned to within the same tolerance as the cavity itself, i.e to within 0:3 mm [1]. The rather conservative tolerance originally set for sputtering at low temperatures can be relaxed by a factor around 10.

Fraser, M A

2013-01-01

368

Synergistic effects of high fat feeding and apolipoprotein E deletion on enterocytic amyloid-beta abundance  

PubMed Central

Background Amyloid-? (A?), a key protein found in amyloid plaques of subjects with Alzheimer's disease is expressed in the absorptive epithelial cells of the small intestine. Ingestion of saturated fat significantly enhances enterocytic A? abundance whereas fasting abolishes expression. Apolipoprotein (apo) E has been shown to directly modulate A? biogenesis in liver and neuronal cells but it's effect in enterocytes is not known. In addition, apo E modulates villi length, which may indirectly modulate A? as a consequence of differences in lipid absorption. This study compared A? abundance and villi length in wild-type (WT) and apo E knockout (KO) mice maintained on either a low-fat or high-fat diet. Wild-type C57BL/6J and apo E KO mice were randomised for six-months to a diet containing either 4% (w/w) unsaturated fats, or chow comprising 16% saturated fats and 1% cholesterol. Quantitative immunohistochemistry was used to assess A? abundance in small intestinal enterocytes. Apo E KO mice given the low-fat diet had similar enterocytic A? abundance compared to WT controls. Results The saturated fat diet substantially increased enterocytic A? in WT and in apo E KO mice, however the effect was greater in the latter. Villi height was significantly greater in apo E KO mice than for WT controls when given the low-fat diet. However, WT mice had comparable villi length to apo E KO when fed the saturated fat and cholesterol enriched diet. There was no effect of the high-fat diet on villi length in apo E KO mice. Conclusion The findings of this study are consistent with the notion that lipid substrate availability modulates enterocytic A?. Apo E may influence enterocytic lipid availability by modulating absorptive capacity. PMID:18426603

Galloway, Susan; Pallebage-Gamarallage, Menuka MS; Takechi, Ryusuke; Jian, Le; Johnsen, Russell D; Dhaliwal, Satvinder S; Mamo, John CL

2008-01-01

369

The National Ignition Facility: The Path to Ignition, High Energy Density Science and Inertial Fusion Energy  

SciTech Connect

The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) in Livermore, CA, is a Nd:Glass laser facility capable of producing 1.8 MJ and 500 TW of ultraviolet light. This world's most energetic laser system is now operational with the goals of achieving thermonuclear burn in the laboratory and exploring the behavior of matter at extreme temperatures and energy densities. By concentrating the energy from its 192 extremely energetic laser beams into a mm{sup 3}-sized target, NIF can produce temperatures above 100 million K, densities of 1,000 g/cm{sup 3}, and pressures 100 billion times atmospheric pressure - conditions that have never been created in a laboratory and emulate those in the interiors of planetary and stellar environments. On September 29, 2010, NIF performed the first integrated ignition experiment which demonstrated the successful coordination of the laser, the cryogenic target system, the array of diagnostics and the infrastructure required for ignition. Many more experiments have been completed since. In light of this strong progress, the U.S. and the international communities are examining the implication of achieving ignition on NIF for inertial fusion energy (IFE). A laser-based IFE power plant will require a repetition rate of 10-20 Hz and a 10% electrical-optical efficiency laser, as well as further advances in large-scale target fabrication, target injection and tracking, and other supporting technologies. These capabilities could lead to a prototype IFE demonstration plant in 10- to 15-years. LLNL, in partnership with other institutions, is developing a Laser Inertial Fusion Energy (LIFE) baseline design and examining various technology choices for LIFE power plant This paper will describe the unprecedented experimental capabilities of the NIF, the results achieved so far on the path toward ignition, the start of fundamental science experiments and plans to transition NIF to an international user facility providing access to researchers around the world. The paper will conclude with a discussion of LIFE, its development path and potential to enable a carbon-free clean energy future.

Moses, E

2011-03-25

370

A region-based high spatial resolution remotely sensed imagery classification algorithm based on multiscale fusion and feature weighting  

NASA Astrophysics Data System (ADS)

With the availability of high resolution multispectral imagery from sensors, it is possible to identify small-scale features in urban environment. Given attributes of image structure such as color, texture, have the character of highly scale dependency, a hierarchy segment fusion algorithm based on region deviation is proposed to extract more robust features and benefit single semantic level land cover classification. The fusion algorithm proposed is divided into in two successive sub-tasks: mean shift (MS) filtering based pre-segmentation and hierarchical segment optimization. Presegmentation is applied to get boundary- preserved and spectrally homogeneous initial regions, and then, a family of nested image partitions with ascending region areas is constructed by iteratively merging procedure. In every scale, regions of the corresponding critical size are evaluated according to potential region merge risk, which is measured by the region standard deviation change before and after a virtual merge. If a region measurement is larger than a specified change threshold, the region will be preserved to the next level and labeled as a candidate segment for following regionbased classification. Otherwise the segment will be merged to the next scale level. After fusing segments in different scales, a novel weighted minimum distance classifier is employed to get supervised classification result, in which every feature band's deviation is used to calculate its own weight. We show results for classification of a HR image over Washington DC Mall area taken by the HYDICE sensor. Different features combined with designed classifier have proved that fused segments provided a robust feature extraction and improve classification accuracy.

Wang, Leiguang; Mei, Tiancan; Qin, Qianqin

2009-10-01

371

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

NASA Astrophysics Data System (ADS)

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 by the single 20-MA power feed of Sandia National Laboratories' Z accelerator. The time-averaged polar radiation asymmetry, /I, is inferred from direct distortion measurements of an imploding capsule's limb-darkened ("backlit") shell, via 6.7 keV point projection x-ray imaging. Thus far, /I has been measured at the 3.0±1.4 (%) level, on the best shots, in hohlraums (cylindrical) with length/radius ratios L/R of 1.61 and 1.69, either side of a L/R=1.66 predicted optimum for a zeroed P2 Legendre mode. Simulations suggest that when scaled to 220 eV with zeroed odd Legendre modes, relevant to the best fraction of shots on a dual power-feed HY accelerator, the increased hohlraum wall albedo would reduce the field asymmetry to the 0.9% level; thus approaching the uniformity requirements of high-yield ignition. Future studies at L/R=1.66 will include refinements in experimental methods and image analysis techniques (denoising), and the measured symmetry is anticipated to improve further.

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

2003-09-01

372

High Resolution Characterization of Heterogeneous Arctic Tundra Subsurface Properties using a Multiscale Bayesian Fusion Approach with  

E-print Network

High Resolution Characterization of Heterogeneous Arctic Tundra Subsurface Properties using of heterogeneous fields in the arctic tundra system, where the mechanistic process models are highly complex

Hubbard, Susan

373

High diversity of extended-spectrum beta-lactamase-producing bacteria in an urban river sediment habitat.  

PubMed

Antibiotic-resistant bacteria (ARB) have been surveyed widely in water bodies, but few studies have determined the diversity of ARB in sediment, which is the most taxon-abundant habitat in aquatic environments. We isolated 56 extended-spectrum beta-lactamase (ESBL)-producing bacteria from a single sediment sample taken from an urban river in China. All strains were confirmed for ESBL-producing capability by both the clavulanic acid combination disc method and MIC determination. Of the isolated strains, 39 were classified as Enterobacteriaceae (consisting of the genera Escherichia, Klebsiella, Serratia, and Aeromonas) by 16S rRNA gene sequencing and biochemical analysis. The present study identifies, for the first time, ESBL-producing strains from the families Brucellaceae and Moraxellaceae. The bla(CTX-M) gene was the most dominant of the ESBL genes (45 strains), while the bla(TEM) gene was the second-most dominant (22 strains). A total of five types of bla(CTX-M) fragments were identified, with both known and novel sequences. A library of bla(CTX-M) cloned from the sediment DNA showed an even higher diversity of bla(CTX-M) sequences. The discovery of highly diverse ESBL-producing bacteria and ESBL genes, particularly bla(CTX), in urban river sediment raises alarms for potential dissemination of ARB in communities through river environments. PMID:20639374

Lu, Su-Ying; Zhang, Ya-Li; Geng, Sui-Na; Li, Tian-Yu; Ye, Zhuo-Ming; Zhang, Dong-Sheng; Zou, Fei; Zhou, Hong-Wei

2010-09-01

374

Theory of coupled whistler-electron temperature gradient mode in high beta plasma: Application to linear plasma device  

SciTech Connect

This paper presents a theory of coupled whistler (W) and electron temperature gradient (ETG) mode using two-fluid model in high beta plasma. Non-adiabatic ion response, parallel magnetic field perturbation ({delta}B{sub z}), perpendicular magnetic flutter ({delta}B{sub perpendicular}), and electron collisions are included in the treatment of theory. A linear dispersion relation for whistler-electron temperature gradient (W-ETG) mode is derived. The numerical results obtained from this relation are compared with the experimental results observed in large volume plasma device (LVPD) [Awasthi et al., Phys. Plasma 17, 42109 (2010)]. The theory predicts that the instability grows only where the temperature gradient is finite and the density gradient flat. For the parameters of the experiment, theoretically estimated frequency and wave number of W-ETG mode match with the values corresponding to the peak in the power spectrum observed in LVPD. By using simple mixing length argument, estimated level of fluctuations of W-ETG mode is in the range of fluctuation level observed in LVPD.

Singh, S. K.; Awasthi, L. M.; Singh, R.; Kaw, P. K.; Jha, R.; Mattoo, S. K. [Institute for Plasma Research, Bhat, Gandhinagar 382 428 (India)

2011-10-15

375

Cathepsin Inhibition-Induced Lysosomal Dysfunction Enhances Pancreatic Beta-Cell Apoptosis in High Glucose  

PubMed Central

Autophagy is a lysosomal degradative pathway that plays an important role in maintaining cellular homeostasis. We previously showed that the inhibition of autophagy causes pancreatic ?-cell apoptosis, suggesting that autophagy is a protective mechanism for the survival of pancreatic ?-cells. The current study demonstrates that treatment with inhibitors and knockdown of the lysosomal cysteine proteases such as cathepsins B and L impair autophagy, enhancing the caspase-dependent apoptosis of INS-1 cells and islets upon exposure to high concentration of glucose. Interestingly, treatment with cathepsin B and L inhibitors prevented the proteolytic processing of cathepsins B, D and L, as evidenced by gradual accumulation of the respective pro-forms. Of note, inhibition of aspartic cathepsins had no effect on autophagy and cell viability, suggesting the selective role of cathepsins B and L in the regulation of ?-cell autophagy and apoptosis. Lysosomal localization of accumulated pro-cathepsins in the presence of cathepsin B and L inhibitors was verified via immunocytochemistry and lysosomal fractionation. Lysotracker staining indicated that cathepsin B and L inhibitors led to the formation of severely enlarged lysosomes in a time-dependent manner. The abnormal accumulation of pro-cathepsins following treatment with inhibitors of cathepsins B and L suppressed normal lysosomal degradation and the processing of lysosomal enzymes, leading to lysosomal dysfunction. Collectively, our findings suggest that cathepsin defects following the inhibition of cathepsin B and L result in lysosomal dysfunction and consequent cell death in pancreatic ?-cells. PMID:25625842

Jung, Minjeong; Lee, Jaemeun; Seo, Hye-Young; Lim, Ji Sun; Kim, Eun-Kyoung

2015-01-01

376

Cathepsin inhibition-induced lysosomal dysfunction enhances pancreatic Beta-cell apoptosis in high glucose.  

PubMed

Autophagy is a lysosomal degradative pathway that plays an important role in maintaining cellular homeostasis. We previously showed that the inhibition of autophagy causes pancreatic ?-cell apoptosis, suggesting that autophagy is a protective mechanism for the survival of pancreatic ?-cells. The current study demonstrates that treatment with inhibitors and knockdown of the lysosomal cysteine proteases such as cathepsins B and L impair autophagy, enhancing the caspase-dependent apoptosis of INS-1 cells and islets upon exposure to high concentration of glucose. Interestingly, treatment with cathepsin B and L inhibitors prevented the proteolytic processing of cathepsins B, D and L, as evidenced by gradual accumulation of the respective pro-forms. Of note, inhibition of aspartic cathepsins had no effect on autophagy and cell viability, suggesting the selective role of cathepsins B and L in the regulation of ?-cell autophagy and apoptosis. Lysosomal localization of accumulated pro-cathepsins in the presence of cathepsin B and L inhibitors was verified via immunocytochemistry and lysosomal fractionation. Lysotracker staining indicated that cathepsin B and L inhibitors led to the formation of severely enlarged lysosomes in a time-dependent manner. The abnormal accumulation of pro-cathepsins following treatment with inhibitors of cathepsins B and L suppressed normal lysosomal degradation and the processing of lysosomal enzymes, leading to lysosomal dysfunction. Collectively, our findings suggest that cathepsin defects following the inhibition of cathepsin B and L result in lysosomal dysfunction and consequent cell death in pancreatic ?-cells. PMID:25625842

Jung, Minjeong; Lee, Jaemeun; Seo, Hye-Young; Lim, Ji Sun; Kim, Eun-Kyoung

2015-01-01

377

Magnetohydrodynamic modes analysis and control of Fusion Advanced Studies Torus high-current scenarios  

SciTech Connect

One of the main FAST (Fusion Advanced Studies Torus) goals is to have a flexible experiment capable to test tools and scenarios for safe and reliable tokamak operation, in order to support ITER and help the final DEMO design. In particular, in this paper, we focus on operation close to a possible border of stability related to low-q operation. To this purpose, a new FAST scenario has then been designed at I{sub p}?=?10 MA, B{sub T}?=?8.5?T, q{sub 95}???2.3. Transport simulations, carried out by using the code JETTO and the first principle transport model GLF23, indicate that, under these conditions, FAST could achieve an equivalent Q???3.5. FAST will be equipped with a set of internal active coils for feedback control, which will produce magnetic perturbation with toroidal number n?=?1 or n?=?2. Magnetohydrodynamic (MHD) mode analysis and feedback control simulations performed with the codes MARS, MARS-F, CarMa (both assuming the presence of a perfect conductive wall and using the exact 3D resistive wall structure) show the possibility of the FAST conductive structures to stabilize n?=?1 ideal modes. This leaves therefore room for active mitigation of the resistive mode (down to a characteristic time of 1?ms) for safety purposes, i.e., to avoid dangerous MHD-driven plasma disruption, when working close to the machine limits and magnetic and kinetic energy density not far from reactor values.

Villone, F.; Mastrostefano, S. [Euratom-ENEA-CREATE Ass., DIEI, Univ. di Cassino e Lazio Merid., Cassino (Italy); Calabrò, G.; Vlad, G.; Crisanti, F.; Fusco, V. [C. R. Frascati, Euratom-ENEA Ass., Via E. Fermi 45, 00044 Frascati (Italy); Marchiori, G.; Bolzonella, T.; Marrelli, L.; Martin, P. [Cons. RFX, Euratom-ENEA-RFX Ass., Corso Stati Uniti 4, 35127 Padova (Italy); Liu, Y. Q. [Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Mantica, P. [IFP-CNR, Euratom-ENEA-CNR Ass. Via Cozzi 53, 20125 Milano (Italy)

2014-08-15

378

Magnetohydrodynamic modes analysis and control of Fusion Advanced Studies Torus high-current scenarios  

NASA Astrophysics Data System (ADS)

One of the main FAST (Fusion Advanced Studies Torus) goals is to have a flexible experiment capable to test tools and scenarios for safe and reliable tokamak operation, in order to support ITER and help the final DEMO design. In particular, in this paper, we focus on operation close to a possible border of stability related to low-q operation. To this purpose, a new FAST scenario has then been designed at Ip = 10 MA, BT = 8.5 T, q95 ? 2.3. Transport simulations, carried out by using the code JETTO and the first principle transport model GLF23, indicate that, under these conditions, FAST could achieve an equivalent Q ? 3.5. FAST will be equipped with a set of internal active coils for feedback control, which will produce magnetic perturbation with toroidal number n = 1 or n = 2. Magnetohydrodynamic (MHD) mode analysis and feedback control simulations performed with the codes MARS, MARS-F, CarMa (both assuming the presence of a perfect conductive wall and using the exact 3D resistive wall structure) show the possibility of the FAST conductive structures to stabilize n = 1 ideal modes. This leaves therefore room for active mitigation of the resistive mode (down to a characteristic time of 1 ms) for safety purposes, i.e., to avoid dangerous MHD-driven plasma disruption, when working close to the machine limits and magnetic and kinetic energy density not far from reactor values.

Villone, F.; Calabrò, G.; Marchiori, G.; Mastrostefano, S.; Vlad, G.; Bolzonella, T.; Crisanti, F.; Fusco, V.; Liu, Y. Q.; Mantica, P.; Marrelli, L.; Martin, P.

2014-08-01

379

A method for detection of cellulases in polyacrylamide gels using 5-bromoindoxyl-beta-D-cellobioside: high sensitivity and resolution.  

PubMed

The assay of endo-1,4-beta-glucanases (cellulases) from Trichoderma reesei, T. longibrachiatum, and Sporotrichum pulverulentum by 5-bromoindoxyl-beta-D-cellobioside is described. The substrate is enzymatically cleaved to afford 5-bromoindoxyl and latter undergoes immediate azo coupling with Fast Red or oxidation by nitroblue monotetrazolium chloride, various forms of endoglucanases which can thus be assayed in polyacrylamide gel. PMID:2610340

Chernoglazov, V M; Ermolova, O V; Vozny, Y V; Klyosov, A A

1989-11-01

380

Early treatment with high-dose interferon beta-1a reverses cognitive and cortical plasticity de?cits in multiple sclerosis.  

PubMed

Acute in?ammation is associated with cognitive de?cits and alterations of cortical plasticity in multiple sclerosis (MS). We tested whether early treatment with high-dose interferon (IFN) beta-1a, known to reduce in?ammatory activity, improves cortical function and cognitive de?cits 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 af-ter 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 de?cits may be rescued during high-doseIFN beta-1a treatment in newly-diagnosed RRMS patients with Gd+ lesions. PMID:23402677

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

381

Reversible hydrogel-solution system of silk with high beta-sheet content.  

PubMed

Silkworm silk has been widely used as a textile fiber, as biomaterials and in optically functional materials due to its extraordinary properties. The ?-sheet-rich natural nanofiber units of about 10-50 nm in diameter are often considered the origin of these properties, yet it remains unclear how silk self-assembles into these hierarchical structures. A new system composed of ?-sheet-rich silk nanofibers about 10-20 nm in diameter is reported here, where these nanofibers formed into "flowing hydrogels" at 0.5-2% solutions and could be transformed back into the solution state at lower concentrations, even with a high ?-sheet content. This is in contrast with other silk processed materials, where significant ?-sheet content negates reversibility between solution and solid states. These fibers are formed by regulating the self-assembly process of silk in aqueous solution, which changes the distribution of negative charges while still supporting ?-sheet formation in the structures. Mechanistically, there appears to be a shift toward negative charges along the outside of the silk nanofibers in our present study, resulting in a higher zeta potential (above -50 mV) than previous silk materials which tend to be below -30 mV. The higher negative charge on silk nanofibers resulted in electrostatic repulsion strong enough to negate further assembly of the nanofibers. Changing silk concentration changed the balance between hydrophobic interactions and electrostatic repulsion of ?-sheet-rich silk nanofibers, resulting in reversible hydrogel-solution transitions. Furthermore, the silk nanofibers could be disassembled into shorter fibers and even nanoparticles upon ultrasonic treatment following the transition from hydrogel to solution due to the increased dispersion of hydrophobic smaller particles, without the loss of ?-sheet content, and with retention of the ability to transition between hydrogel and solution states through reversion to longer nanofibers during self-assembly. These reversible solution-hydrogel transitions were tunable with ultrasonic intensity, time, or temperature. PMID:25056606

Bai, Shumeng; Zhang, Xiuli; Lu, Qiang; Sheng, Weiqin; Liu, Lijie; Dong, Boju; Kaplan, David L; Zhu, Hesun

2014-08-11

382

Beta Thalassemia  

MedlinePLUS

... 1 Beta thalassemia is found in people of Mediterranean, Middle Eastern, African, South Asian (Indian, Pakistani, etc.), ... is commonly found in people of African or Mediterranean ancestry, such as Africans, Italians, Greeks, Turks, and ...

383

Red beet (Beta vulgaris L.) leaf supplementation improves antioxidant status in C57BL/6J mice fed high fat high cholesterol diet  

PubMed Central

The effect of diet supplemented with red beet (Beta vulgaris L.) leaf on antioxidant status of plasma and tissue was investigated in C57BL/6J mice. The mice were randomly divided into two groups after one-week acclimation, and fed a high fat (20%) and high cholesterol (1%) diet without (control group) or with 8% freeze-dried red beet leaf (RBL group) for 4 weeks. In RBL mice, lipid peroxidation determined as 2-thiobarbituric acid-reactive substances (TBARS value) was significantly reduced in the plasma and selected organs (liver, heart, and kidney). Levels of antioxidants (glutathione and ?-carotene) and the activities of antioxidant enzyme (glutathione peroxidase) in plasma and liver were considerably increased, suggesting that antioxidant defenses were improved by RBL diet. Comet parameters such as tail DNA (%), tail extent moment, olive tail moment and tail length were significantly reduced by 25.1%, 49.4%, 35.4%, and 23.7%, respectively, in plasma lymphocyte DNA of RBL mice compared with control mice, and indicated the increased resistance of lymphocyte DNA to oxidative damage. In addition, the RBL diet controlled body weight together with a significant reduction of fat pad (retroperitoneal, epididymal, inguinal fat, and total fat). Therefore, the present study suggested that the supplementation of 8% red beet leaf in high fat high cholesterol diet could prevent lipid peroxidation and improve antioxidant defense system in the plasma and tissue of C57BL/6J mice. PMID:20016711

Lee, Jeung Hee; Son, Chan Wook; Kim, Mi Yeon; Kim, Min Hee; Kim, Hye Ran; Kwak, Eun Shil; Kim, Sena

2009-01-01

384

Time-resolved compression of a capsule with a cone to high density for fast-ignition laser fusion  

NASA Astrophysics Data System (ADS)

The advent of high-intensity lasers enables us to recreate and study the behaviour of matter under the extreme densities and pressures that exist in many astrophysical objects. It may also enable us to develop a power source based on laser-driven nuclear fusion. Achieving such conditions usually requires a target that is highly uniform and spherically symmetric. Here we show that it is possible to generate high densities in a so-called fast-ignition target that consists of a thin shell whose spherical symmetry is interrupted by the inclusion of a metal cone. Using picosecond-time-resolved X-ray radiography, we show that we can achieve areal densities in excess of 300?mg?cm?2 with a nanosecond-duration compression pulse—the highest areal density ever reported for a cone-in-shell target. Such densities are high enough to stop MeV electrons, which is necessary for igniting the fuel with a subsequent picosecond pulse focused into the resulting plasma.

Theobald, W.; Solodov, A. A.; Stoeckl, C.; Anderson, K. S.; Beg, F. N.; Epstein, R.; Fiksel, G.; Giraldez, E. M.; Glebov, V. Yu.; Habara, H.; Ivancic, S.; Jarrott, L. C.; Marshall, F. J.; McKiernan, G.; McLean, H. S.; Mileham, C.; Nilson, P. M.; Patel, P. K.; Pérez, F.; Sangster, T. C.; Santos, J. J.; Sawada, H.; Shvydky, A.; Stephens, R. B.; Wei, M. S.

2014-12-01

385

Time-resolved compression of a capsule with a cone to high density for fast-ignition laser fusion.  

PubMed

The advent of high-intensity lasers enables us to recreate and study the behaviour of matter under the extreme densities and pressures that exist in many astrophysical objects. It may also enable us to develop a power source based on laser-driven nuclear fusion. Achieving such conditions usually requires a target that is highly uniform and spherically symmetric. Here we show that it is possible to generate high densities in a so-called fast-ignition target that consists of a thin shell whose spherical symmetry is interrupted by the inclusion of a metal cone. Using picosecond-time-resolved X-ray radiography, we show that we can achieve areal densities in excess of 300?mg?cm(-2) with a nanosecond-duration compression pulse-the highest areal density ever reported for a cone-in-shell target. Such densities are high enough to stop MeV electrons, which is necessary for igniting the fuel with a subsequent picosecond pulse focused into the resulting plasma. PMID:25503788

Theobald, W; Solodov, A A; Stoeckl, C; Anderson, K S; Beg, F N; Epstein, R; Fiksel, G; Giraldez, E M; Glebov, V Yu; Habara, H; Ivancic, S; Jarrott, L C; Marshall, F J; McKiernan, G; McLean, H S; Mileham, C; Nilson, P M; Patel, P K; Pérez, F; Sangster, T C; Santos, J J; Sawada, H; Shvydky, A; Stephens, R B; Wei, M S

2014-01-01

386

Signaling Mechanisms in Mammalian Myoblast Fusion  

NSDL National Science Digital Library

Skeletal muscles are formed by the fusion of multiple myoblasts during development. Myoblast fusion is also essential for the growth and repair of injured myofibers. Recent investigations have shown that the process of myoblast fusion involves the activation of several cell signaling pathways, including those mediated by nuclear factor κB, mitogen-activated protein kinases, Wnt, calcineurin–nuclear factor of activated T cells c2, transforming growth factor–&beta;–Smad4, and the Rho guanosine triphosphatases. In this Review, which contains 2 figures and 84 references, we summarize the mechanisms by which the activation of these signaling pathways stimulates myoblast fusion.

Ashok Kumar (University of Louisville;School of Medicine REV); Sajedah M. Hindi (University of Louisville;School of Medicine REV); Marjan M. Tajrishi (University of Louisville;School of Medicine REV)

2013-04-23

387

Hydrophobin Fusion of an Influenza Virus Hemagglutinin Allows High Transient Expression in Nicotiana benthamiana, Easy Purification and Immune Response with Neutralizing Activity.  

PubMed

The expression of recombinant hemagglutinin in plants is a promising alternative to the current egg-based production system for the influenza vaccines. Protein-stabilizing fusion partners have been developed to overcome the low production yields and the high downstream process costs associated with the plant expression system. In this context, we tested the fusion of hydrophobin I to the hemagglutinin ectodomain of the influenza A (H1N1)pdm09 virus controlled by the hybrid En2PMA4 transcriptional promoter to rapidly produce high levels of recombinant antigen by transient expression in agro-infiltrated Nicotiana benthamiana leaves. The fusion increased the expression level by a factor of ?2.5 compared to the unfused protein allowing a high accumulation level of 8.6% of the total soluble proteins. Hemagglutinin was located in ER-derived protein bodies and was successfully purified by combining an aqueous-two phase partition system and a salting out step. Hydrophobin interactions allowed the formation of high molecular weight hemagglutinin structures, while unfused proteins were produced as monomers. Purified protein was shown to be biologically active and to induce neutralizing antibodies after mice immunization. Hydrophobin fusion to influenza hemagglutinin might therefore be a promising approach for rapid, easy, and low cost production of seasonal or pandemic influenza vaccines in plants. PMID:25541987

Jacquet, Nicolas; Navarre, Catherine; Desmecht, Daniel; Boutry, Marc

2014-01-01

388

Hydrophobin Fusion of an Influenza Virus Hemagglutinin Allows High Transient Expression in Nicotiana benthamiana, Easy Purification and Immune Response with Neutralizing Activity  

PubMed Central

The expression of recombinant hemagglutinin in plants is a promising alternative to the current egg-based production system for the influenza vaccines. Protein-stabilizing fusion partners have been developed to overcome the low production yields and the high downstream process costs associated with the plant expression system. In this context, we tested the fusion of hydrophobin I to the hemagglutinin ectodomain of the influenza A (H1N1)pdm09 virus controlled by the hybrid En2PMA4 transcriptional promoter to rapidly produce high levels of recombinant antigen by transient expression in agro-infiltrated Nicotiana benthamiana leaves. The fusion increased the expression level by a factor of ?2.5 compared to the unfused protein allowing a high accumulation level of 8.6% of the total soluble proteins. Hemagglutinin was located in ER-derived protein bodies and was successfully purified by combining an aqueous-two phase partition system and a salting out step. Hydrophobin interactions allowed the formation of high molecular weight hemagglutinin structures, while unfused proteins were produced as monomers. Purified protein was shown to be biologically active and to induce neutralizing antibodies after mice immunization. Hydrophobin fusion to influenza hemagglutinin might therefore be a promising approach for rapid, easy, and low cost production of seasonal or pandemic influenza vaccines in plants. PMID:25541987

Jacquet, Nicolas; Navarre, Catherine; Desmecht, Daniel; Boutry, Marc

2014-01-01

389

Channel planform geometry and slopes from freely available high-spatial resolution imagery and DEM fusion: Implications for channel width scalings, erosion proxies,  

E-print Network

Channel planform geometry and slopes from freely available high-spatial resolution imagery and DEM fusion: Implications for channel width scalings, erosion proxies, and fluvial signatures in tectonicallyGeom) to extract continuous channel width and centerline datasets for single-thread channels using freely available

Bookhagen, Bodo

390

Transport of carbon ion test particles and hydrogen recycling in the plasma of the Columbia tokamak HBT'' (High Beta Tokamak)  

SciTech Connect

Carbon impurity ion transport is studied in the Columbia High Beta Tokamak (HBT), using a carbon tipped probe which is inserted into the plasma (n{sub e} {approx} 1 {minus} 5 {times} 10{sup 14} (cm{sup {minus}3}), T{sub e} {approx} 4 {minus} 10 (eV), B{sub t} {approx} 0.2 {minus} 0.4(T)). Carbon impurity light, mainly the strong lines of C{sub II}(4267A, emitted by the C{sup +} ions) and C{sub III} (4647A, emitted by the C{sup ++} ions), is formed by the ablation or sputtering of plasma ions and by the discharge of the carbon probe itself. The diffusion transport of the carbon ions is modeled by measuring the space-and-time dependent spectral light emission of the carbon ions with a collimated optical beam and photomultiplier. The point of emission can be observed in such a way as to sample regions along and transverse to the toroidal magnetic field. The carbon ion diffusion coefficients are obtained by fitting the data to a diffusion transport model. It is found that the diffusion of the carbon ions is classical'' and is controlled by the high collisionality of the HBT plasma; the diffusion is a two-dimensional problem and the expected dependence on the charge of the impurity ion is observed. The measurement of the spatial distribution of the H{sub {alpha}} emissivity was obtained by inverting the light signals from a 4-channel polychromator, the data were used to calculate the minor-radial influx, the density, and the recycling time of neutral hydrogen atoms or molecules. The calculation shows that the particle recycling time {tau}{sub p} is comparable with the plasma energy confinement time {tau}{sub E}; therefore, the recycling of the hot plasma ions with the cold neutrals from the walls is one of the main mechanisms for loss of plasma energy.

Wang, Jian-Hua.

1990-01-01

391

Cosmic Evolution of Accretion Power and Fusion Power: AGN and Starbursts at High Redshifts  

NASA Astrophysics Data System (ADS)

Extragalactic astronomers have been working for decades on obtaining robust measures of the luminosities galaxies produce from stars, and from active galactic nuclei. Our ultimate goal is deriving the cosmic evolution of all radiation produced by fusion and by black hole accretion. The combined effects of dust reddening and redshift make it impossible to achieve this with optical observations alone. Fortunately, infrared thermal continuum and forbidden line emission--from warm dust grains and ionized gas, respectively--can now be measured with excellent sensitivity. However, when measuring entire galaxies, these dust and gas emissions are powered by both active galactic nuclei and starbursts, which may be hard to separate spatially. We must use the fact that the patterns of IR energy output from AGN and SBs differ, with AGN making more ionized gas and hotter dust grains. Low-resolution spectroscopy, or even narrow-band filters can sort out the line emission from both processes when they are mixed in the same galaxy. The hope is that these spectroscopic determinations of star formation rate, and mass accretion rate in relatively small samples of bright galaxies will allow a calibration of broadband continuum measures. The dust continuum emission will then be measured in enormous samples of galaxies spanning their full range of masses, metallicities, environments and redshifts. Along the way, we should learn the astrophysical basis of black hole/galaxy "co-evolution." I will summarize some of the first specific infrared steps of this ambitious agenda, taken with IRAS and ISO to 2MASS, Akari and Spitzer and other telescopes. Time permitting, some of the exciting upcoming observational prospects will be advertised.

Arnold Malkan, Matthew

2009-05-01

392

Proteolytic cleavage of Opa1 stimulates mitochondrial inner membrane fusion and couples fusion to oxidative phosphorylation.  

PubMed

Mitochondrial fusion is essential for maintenance of mitochondrial function. The mitofusin GTPases control mitochondrial outer membrane fusion, whereas the dynamin-related GTPase Opa1 mediates inner membrane fusion. We show that mitochondrial inner membrane fusion is tuned by the level of oxidative phosphorylation (OXPHOS), whereas outer membrane fusion is insensitive. Consequently, cells from patients with pathogenic mtDNA mutations show a selective defect in mitochondrial inner membrane fusion. In elucidating the molecular mechanism of OXPHOS-stimulated fusion, we uncover that real-time proteolytic processing of Opa1 stimulates mitochondrial inner membrane fusion. OXPHOS-stimulated mitochondrial fusion operates through Yme1L, which cleaves Opa1 more efficiently under high OXPHOS conditions. Engineered cleavage of Opa1 is sufficient to mediate inner membrane fusion, regardless of respiratory state. Proteolytic cleavage therefore stimulates the membrane fusion activity of Opa1, and this feature is exploited to dynamically couple mitochondrial fusion to cellular metabolism. PMID:24703695

Mishra, Prashant; Carelli, Valerio; Manfredi, Giovanni; Chan, David C

2014-04-01

393

Magnetized Target Fusion  

NASA Technical Reports Server (NTRS)

Magnetized target fusion (MTF) is under consideration as a means of building a low mass, high specific impulse, and high thrust propulsion system for interplanetary travel. This unique combination is the result of the generation of a high temperature plasma by the nuclear fusion process. This plasma can then be deflected by magnetic fields to provide thrust. Fusion is initiated by a small traction of the energy generated in the magnetic coils due to the plasma's compression of the magnetic field. The power gain from a fusion reaction is such that inefficiencies due to thermal neutrons and coil losses can be overcome. Since the fusion reaction products are directly used for propulsion and the power to initiate the reaction is directly obtained from the thrust generation, no massive power supply for energy conversion is required. The result should be a low engine mass, high specific impulse and high thrust system. The key is to successfully initiate fusion as a proof-of-principle for this application. Currently MSFC is implementing MTF proof-of-principle experiments. This involves many technical details and ancillary investigations. Of these, selected pertinent issues include the properties, orientation and timing of the plasma guns and the convergence and interface development of the "pusher" plasma. Computer simulations of the target plasma's behavior under compression and the convergence and mixing of the gun plasma are under investigation. This work is to focus on the gun characterization and development as it relates to plasma initiation and repeatability.

Griffin, Steven T.

2002-01-01

394

Harnessing High Density Lipoproteins to Block Transforming Growth Factor Beta and to Inhibit the Growth of Liver Tumor Metastases  

PubMed Central

Transforming growth factor ? (TGF-?) is a powerful promoter of cancer progression and a key target for antitumor therapy. As cancer cells exhibit active cholesterol metabolism, high density lipoproteins (HDLs) appear as an attractive delivery system for anticancer TGF?-inhibitory molecules. We constructed a plasmid encoding a potent TGF-?-blocking peptide (P144) linked to apolipoprotein A-I (ApoA-I) through a flexible linker (pApoLinkerP144). The ApoLinkerP144 sequence was then incorporated into a hepatotropic adeno-associated vector (AAVApoLinkerP144). The aim was to induce hepatocytes to produce HDLs containing a modified ApoA-I capable of blocking TGF-?. We observed that transduction of the murine liver with pApoLinkerP144 led to the appearance of a fraction of circulating HDL containing the fusion protein. These HDLs were able to attenuate TGF-? signaling in the liver and to enhance IL-12 -mediated IFN-? production. Treatment of liver metastasis of MC38 colorectal cancer with AAVApoLinkerP144 resulted in a significant reduction of tumor growth and enhanced expression of IFN-? and GM-CSF in cancerous tissue. ApoLinkerP144 also delayed MC38 liver metastasis in Rag2?/?IL2r??/? immunodeficient mice. This effect was associated with downregulation of TGF-? target genes essential for metastatic niche conditioning. Finally, in a subset of ret transgenic mice, a model of aggressive spontaneous metastatic melanoma, AAVApoLinkerP144 delayed tumor growth in association with increased CD8+ T cell numbers in regional lymph nodes. In conclusion, modification of HDLs to transport TGF-?-blocking molecules is a novel and promising approach to inhibit the growth of liver metastases by immunological and non-immunological mechanisms. PMID:24797128

Medina-Echeverz, José; Fioravanti, Jessica; Díaz-Valdés, Nancy; Frank, Kathrin; Aranda, Fernando; Gomar, Celia; Ardaiz, Nuria; Dotor, Javier; Umansky, Viktor; Prieto, Jesús; Berraondo, Pedro

2014-01-01

395

The Complete Burning of Weapons Grade Plutonium and Highly Enriched Uranium with (Laser Inertial Fusion-Fission Energy) LIFE Engine  

Microsoft Academic Search

The National Ignition Facility (NIF) project, a laser-based Inertial Confinement Fusion (ICF) experiment designed to achieve thermonuclear fusion ignition and burn in the laboratory, is under construction at the Lawrence Livermore National Laboratory (LLNL) and will be completed in April of 2009. Experiments designed to accomplish the NIF's goal will commence in late FY2010 utilizing laser energies of 1 to

J C Farmer; T Diaz de la Rubia; E Moses

2008-01-01

396

Research on fusion neutron sources  

SciTech Connect

The use of fusion devices as powerful neutron sources has been discussed for decades. Whereas the successful route to a commercial fusion power reactor demands steady state stable operation combined with the high efficiency required to make electricity production economic, the alternative approach to advancing the use of fusion is free of many of complications connected with the requirements for economic power generation and uses the already achieved knowledge of Fusion physics and developed Fusion technologies. 'Fusion for Neutrons' (F4N), has now been re-visited, inspired by recent progress achieved on comparably compact fusion devices, based on the Spherical Tokamak (ST) concept. Freed from the requirement to produce much more electricity than used to drive it, a fusion neutron source could be efficiently used for many commercial applications, and also to support the goal of producing energy by nuclear power. The possibility to use a small or medium size ST as a powerful or intense steady-state fusion neutron source (FNS) is discussed in this paper in comparison with the use of traditional high aspect ratio tokamaks. An overview of various conceptual designs of compact fusion neutron sources based on the ST concept is given and they are compared with a recently proposed Super Compact Fusion Neutron Source (SCFNS), with major radius as low as 0.5 metres but still able to produce several MW of neutrons in a steady-state regime.

Gryaznevich, M. P. [Tokamak Solutions UK, Culham Science Centre, Abingdon, OXON, OX133DB (United Kingdom)

2012-06-19

397

Research on fusion neutron sources  

NASA Astrophysics Data System (ADS)

The use of fusion devices as powerful neutron sources has been discussed for decades. Whereas the successful route to a commercial fusion power reactor demands steady state stable operation combined with the high efficiency required to make electricity production economic, the alternative approach to advancing the use of fusion is free of many of complications connected with the requirements for economic power generation and uses the already achieved knowledge of Fusion physics and developed Fusion technologies. "Fusion for Neutrons" (F4N), has now been re-visited, inspired by recent progress achieved on comparably compact fusion devices, based on the Spherical Tokamak (ST) concept. Freed from the requirement to produce much more electricity than used to drive it, a fusion neutron source could be efficiently used for many commercial applications, and also to support the goal of producing energy by nuclear power. The possibility to use a small or medium size ST as a powerful or intense steady-state fusion neutron source (FNS) is discussed in this paper in comparison with the use of traditional high aspect ratio tokamaks. An overview of various conceptual designs of compact fusion neutron sources based on the ST concept is given and they are compared with a recently proposed Super Compact Fusion Neutron Source (SCFNS), with major radius as low as 0.5 metres but still able to produce several MW of neutrons in a steady-state regime.

Gryaznevich, M. P.

2012-06-01

398