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Sample records for 3kv 600a 4h-sic

  1. Kv1.3/Kv1.5 heteromeric channels compromise pharmacological responses in macrophages

    SciTech Connect

    Villalonga, Nuria; Escalada, Artur; Vicente, Ruben; Sanchez-Tillo, Ester; Celada, Antonio; Solsona, Carles; Felipe, Antonio . E-mail: afelipe@ub.edu

    2007-01-26

    Voltage-dependent K{sup +} (Kv) channels are involved in the immune response. Kv1.3 is highly expressed in activated macrophages and T-effector memory cells of autoimmune disease patients. Macrophages are actively involved in T-cell activation by cytokine production and antigen presentation. However, unlike T-cells, macrophages express Kv1.5, which is resistant to Kv1.3-drugs. We demonstrate that mononuclear phagocytes express different Kv1.3/Kv1.5 ratios, leading to biophysically and pharmacologically distinct channels. Therefore, Kv1.3-based treatments to alter physiological responses, such as proliferation and activation, are impaired by Kv1.5 expression. The presence of Kv1.5 in the macrophagic lineage should be taken into account when designing Kv1.3-based therapies.

  2. Pulsed Power Switching of 4H-SIC Vertical D-Mosfet and Device Characterization

    DTIC Science & Technology

    2013-06-01

    Lawson and Stephen B. Bayne Texas Tech University, Electrical and Computer Engineering Department, Lubbock, TX 79409, USA Lin Cheng and Anant K...due to a 17% decrease in the on resistance (RdsON) with a gate bias of 20V. V. REFERENCES [1] Lawson, K.; Bayne , S.B., "Transient analysis of...2010 [2] Bayne , S.B.; Ibitayo, D., "Evaluation of SiC GTOs for pulse power switching," Pulsed Power Conference, 2003. Digest of Technical Papers

  3. Catalytic properties of thimet oligopeptidase H600A mutant

    SciTech Connect

    Machado, Mauricio F.M.; Marcondes, Marcelo F.; Rioli, Vanessa; Ferro, Emer S.; Juliano, Maria A.; Juliano, Luiz; Oliveira, Vitor

    2010-04-02

    Thimet oligopeptidase (EC 3.4.24.15, TOP) is a metallo-oligopeptidase that participates in the intracellular metabolism of peptides. Predictions based on structurally analogous peptidases (Dcp and ACE-2) show that TOP can present a hinge-bend movement during substrate hydrolysis, what brings some residues closer to the substrate. One of these residues that in TOP crystallographic structure are far from the catalytic residues, but, moves toward the substrate considering this possible structural reorganization is His{sup 600}. In the present work, the role of His{sup 600} of TOP was investigated by site-directed mutagenesis. TOP H600A mutant was characterized through analysis of S{sub 1} and S{sub 1}' specificity, pH-activity profile and inhibition by JA-2. Results showed that TOP His{sup 600} residue makes important interactions with the substrate, supporting the prediction that His{sup 600} moves toward the substrate due to a hinge movement similar to the Dcp and ACE-2. Furthermore, the mutation H600A affected both K{sub m} and k{sub cat}, showing the importance of His{sup 600} for both substrate binding and/or product release from active site. Changes in the pH-profile may indicate also the participation of His{sup 600} in TOP catalysis, transferring a proton to the newly generated NH{sub 2}-terminus or helping Tyr{sup 605} and/or Tyr{sup 612} in the intermediate oxyanion stabilization.

  4. 20 kV, 2 cm2, 4H-SIC Gate Turn-Off Thyristors for Advanced Pulsed Power Applications

    DTIC Science & Technology

    2013-06-01

    diode, the SiC GTO and SiC PiN diode based converter can improve the efficiency by 1% at room-temperature and more than 6% at 200C for an HVDC interface...Models for HVDC Converter”, IEEE Industry Applications Society Annual Meeting (IAS 2004), Oct 3-7, 2004, Seattle, Washington. [5] S. Ryu, C. Capell, C

  5. 75 FR 65499 - Agency Information Collection Activities: Form I-600/I-600A, Extension of a Currently Approved...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-25

    ... SECURITY U.S. Citizenship and Immigration Services Agency Information Collection Activities: Form I-600/ I... of Information Collection Under Review: Form I- 600/ I-600A, Petition to Classify Orphan as an... Department of Homeland Security sponsoring the collection: Form I-600/ I-600A; U.S. Citizenship...

  6. 75 FR 35824 - Agency Information Collection Activities: Forms I-600/I-600A, Extension of a Currently Approved...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-23

    ... SECURITY U.S. Citizenship and Immigration Services Agency Information Collection Activities: Forms I-600/I... of Information Collection Under Review: Forms I- 600/I-600A, Petition To Classify Orphan as an... USCIS will be evaluating whether to revise the Form I-600/I-600A. Should USCIS decide to revise the...

  7. Effect of ZnO nanoparticles in R290/R600a (50/50) based vapour compression refrigeration system added via lubricant oil on compressor suction and discharge characteristics

    NASA Astrophysics Data System (ADS)

    Kumar, Ravinder; Singh, Jagdev

    2016-10-01

    The primary source of energy consumption in a vapour compression refrigeration system is a compressor. The possibility of a reduction in the work of compression may leads to enhance the compressor suction and discharge characteristics and the overall performance of the refrigeration system. The present experimental investigation based upon the study of ZnO nanoparticles in a vapour compression refrigeration system using hydrocarbon blend R290/R600a (50/50) as a refrigerant. The zinc oxide nanoparticles are appended with system refrigerant via compressor lubricating oil. The results observed that by using different weight concentrations of nanoparticles in R290/R600a refrigeration system, both the compressor suction and discharge pressures and temperatures were reduced compared to conventional system. The viscosity of mineral oil with the addition of nanoparticles increases. The compressor energy consumption was reduced by 7.48 % using (0.2-1.0) wt% concentrations of nanoparticles. The COP of the refrigeration system has been increased by about 46 % with the addition of nanoparticles. Thus, the ZnO nanoparticles worked efficiently in the R290/R600a refrigeration system.

  8. Mathematical Modeling of Thermal Modes of Closed Two-Phase Thermosyphons with Refrigerant R600A

    NASA Astrophysics Data System (ADS)

    Krasnoshlykov, A. S.; Zagromov, Y. A.

    2016-02-01

    Numerical analysis using the software package ANSYS FLUENT has been carried out. Characteristic temperature distribution, streamlines and velocity vectors for various heat loads have been obtained. The study found the possibility of using the software package for analysis of the energy transfer processes at high thermal loads.

  9. Is the σ(600) a glueball? Two photon reactions can tell us

    NASA Astrophysics Data System (ADS)

    Pennington, M. R.

    2001-08-01

    Minkowski and Ochs have recently argued that the small two photon coupling of a conjectured σ(600) is so small that it is likely to be a glueball. We ask whether this can be so or whether it is simply gauge invariance that produces the observed low mass suppression?

  10. Short- and Long-Term Dynamics of Gas Hydrate at GC600: A Gulf of Mexico Hydrocarbon Seep

    NASA Astrophysics Data System (ADS)

    MacDonald, I. R.; Johansen, C.; Silva, M.; Daneshgar, S.; Garcia-Pineda, O. G.; Shedd, W. W.

    2014-12-01

    The GC600 hydrocarbon seep is located at 1200 m in the northern Gulf of Mexico (GOM). Satellite data show it to be one of the most prolific sources of natural oil slicks in the entire GOM. We mapped its seafloor oil and gas vents with 3-D seismic, swath-bathymetry acoustics and submersible observations, documenting gas hydrate deposits, brine pools, benthic fauna, and authigenic carbonates. Geophysical profiles show subbottom locations of salt bodies and migration conduits. We deployed time-lapse imaging systems focused on individual vents to quantify release rates. Oil and gas flow upward along the flanks of an allochthonous salt body from source rocks at 10,000 m and migrate to the seafloor from faults emanating from the salt. Venting to the water column and surface consists of oily bubbles and occurs in two fields separated by ~1 km. The NW vent field (Megaplume) appears to be a more recent expression and hosts about three highly active vents; while the SE vent field (Birthday Candles) hosts more than 10 vents that are generally slower. We measured discharge rates of 2.6 cm3 s-1 and Megaplume and 0.09 cm3 s-1 at Birthday Candles. Although surface deposits of gas hydrate were evident at both vent fields, the Birthday Candles area featured dozens of conical mounds formed by gas hydrate that were dark brown due to large amounts of liquid oil perfused throughout the deposits. Large brine pools indicated gas hydrate formation at the seafloor. Venting occurred in horizontal fissures on the mounds, in which oil and hydrate combined to form short-lived chimneys and balloon-like structures. Ice worms (Hesiocaeca methanicola) were extremely abundant in burrows extending from the sediment into the gas hydrate. Proceeding farther to the SE, venting is reduced and absent, but surface carbonate deposits suggest relict gas hydrate mounds. We propose that the NW to SE trend at GC600 encompasses the progressive development of a biogeochemical filter that sequesters and mineralizes a very substantial portion of the source hydrocarbon prior to discharge into the water column.

  11. 76 FR 1346 - Airworthiness Directives; Airbus Model A300, A300-600, A310, A318, A319, A320, A321, A330-300...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-10

    ... Series Airplanes; and Model A330-201, A330-202, A330- 203, A330-223, A330-243 Airplanes AGENCY: Federal... affected airplanes identified above. This AD requires modifying the flight deck door. This AD was prompted... AD for Model A300, A300- 600, and A310 series airplanes, contact Airbus SAS--EAW...

  12. 76 FR 22302 - Airworthiness Directives; Airbus Model A310 Series Airplanes; and Model A300 B4-600, A300 B4-600R...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-21

    ...We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition...

  13. Evaluating Voltage Regulation Compliance of Mil-Pre-GCS600A(ARMY) for Vehicle On-Board Generators and Assessing Overall Vehicle Bus Compliance

    DTIC Science & Technology

    2012-08-01

    was a Permanent Magnet Synchronous Machine (PMSM). PMSM generators are being used for vehicle on-board electrical power generation because of their...system can be validated in the laboratory. However, determining overall vehicle electrical system compliance before prototype integration is more...can aid in optimization of the electrical system, i.e. vehicle bus capacitance sizing and allocation. Vehicle electrical system compliance can be

  14. Evaluating Voltage Regulation Compliance of MIL-PRF-GCS600A (Army) for Vehicle On-Board Generators and Assessing Overall Vehicle Bus Compliance

    DTIC Science & Technology

    2012-08-16

    Equivalent Circuit 16 August 2012 UNCLASSIFIED UNCLASSIFIED Experimental Setup • AC Dynamometer – Constant Torque: 1244N·m from 0-2,000rpm... Dynamometer – Speed Command – Torque response UNCLASSIFIED UNCLASSIFIED Simulation Results and Modeling Parameter Variation 16 August 2012

  15. The ERTS-1 investigation (ER-600): A compendium of analysis results of the utility of ERTS-1 data for land resources management

    NASA Technical Reports Server (NTRS)

    Erb, R. B.

    1974-01-01

    The results of the ERTS-1 investigations conducted by the Earth Observations Division at the NASA Lyndon B. Johnson Space Center are summarized in this report, which is an overview of documents detailing individual investigations. Conventional image interpretation and computer-aided classification procedures were the two basic techniques used in analyzing the data for detecting, identifying, locating, and measuring surface features related to earth resources. Data from the ERTS-1 multispectral scanner system were useful for all applications studied, which included agriculture, coastal and estuarine analysis, forestry, range, land use and urban land use, and signature extension. Percentage classification accuracies are cited for the conventional and computer-aided techniques.

  16. 75 FR 51698 - Airworthiness Directives; Airbus Model A310 Series Airplanes; and Model A300 B4-600, A300 B4-600R...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-23

    ... unsafe condition as: The ball screw nut assemblies of the first 70 Trimmable Horizontal Stabilizer... engaged and not detected could lead to failure of the secondary load path, which would likely result in... products. The MCAI states: The ball screw nut assemblies of the first 70 Trimmable Horizontal...

  17. Demonstration of the First 4H-SiC EUV Detector with Large Detection Area

    NASA Technical Reports Server (NTRS)

    Xin, Xiaobin; Yan, Feng; Koeth, Timothy W.; Hu, Jun; Zhao, Jian H.

    2005-01-01

    Ultraviolet (UV) and Extreme Ultraviolet (EUV) detectors are very attractive in astronomy, photolithography and biochemical applications. For EUV applications, most of the semiconductor detectors based on PN or PIN structures suffer from the very short penetration depth. Most of the carries are absorbed at the surface and recombined there due to the high surface recombination before reach the depletion region, resulting very low quantum efficiency. On the other hand, for Schottky structures, the active region starts from the surface and carriers generated from the surface can be efficiently collected. 4H-Sic has a bandgap of 3.26eV and is immune to visible light background noise. Also, 4H-Sic detectors usually have very good radiation hardness and very low noise, which is very important for space applications where the signal is very weak. The E W photodiodes presented in this paper are based on Schottky structures. Platinum (Pt) and Nickel (Ni) are selected as the Schottky contact metals, which have the highest electron work functions (5.65eV and 5.15eV, respectively) among all the known metals on 4H-Sic.

  18. 76 FR 47430 - Airworthiness Directives; Airbus Model A300 B4-600, A300 B4-600R, and A300 F4-600R Series...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-05

    ...: Hamilton Sundstrand (HS), the manufacturer of the RAT [ram air turbine], reported the failure during a wind... fastening screw on the RAT turbine cover during a wind tunnel test. After investigation, it has been discovered that a batch of screws, used to attach the balance washers of the RAT Turbine assembly, has...

  19. 76 FR 25259 - Airworthiness Directives; Airbus Model A300 B4-600, A300 B4-600R, and A300 F4-600R Series...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-04

    ...], reported the failure during a wind tunnel test of a balance weight fastening screw on the RAT turbine cover... balance weight fastening screw on the RAT turbine cover during a wind tunnel test. After investigation, it has been discovered that a batch of screws, used to attach the balance washers of the RAT...

  20. Growth and Characterization of Silicon-Carbide Hetero-Polytype Structures

    NASA Technical Reports Server (NTRS)

    Skowronski, Marek

    2004-01-01

    Films discussed in this repok were deposited at NASA Glenn Research Center on on- orientation 4H-Sic substrates. Substrates were patterned in order to form mesa structures of different shapes and sizes. The nominal thickness of the 3C-Sic film was approximately 10 microns although the thickness could change considerably between defect-free and defected mesa structures. The primary objective was to identify defect structures in defect-free mesas and in particular determine the degree and mode of strain relaxation in 3C films with thickness exceeding critical thickness.

  1. Results of tests in the NASA/LaRC 31-inch CFHT on an 0.010-scale model (32-OT) of the space shuttle configuration 3 to determine the RCS jet flowfield interaction effects on aerodynamic characteristics (IA60/0A105), volume 1

    NASA Technical Reports Server (NTRS)

    Thornton, D. E.

    1974-01-01

    Tests were conducted in the 31-inch continuous Flow Hypersonic Wind Tunnel to determine RCS jet interaction effect on the hypersonic aerodynamic and stability and control characteristics prior to RTLS abort separation. The model used was an 0.010-scale replica of the Space Shuttle Vehicle Configuration 3. Hypersonic stability data were obtained from tests at Mach 10.3 and dynamic pressure of 150 psf for the integrated Orbiter and external tank and the Orbiter alone. RCS modes of pitch, yaw, and roll at free flight dynamic pressure simulation of 7, 20, and 50 psf were investigated. The effects of speedbrake, bodyflap, elevon, and airleron deflections were also investigated.

  2. Guidance, Navigation and Control Digital Emulation Technology Laboratory. Volume 1. Part 3. Task 1: Digital Emulation Technology Laboratory

    DTIC Science & Technology

    1991-09-27

    VW(3) WC(3) REAL PGD(3) PG(3) PM(3) REAL AT(3) AC(3) TI2M(9) REAL KA KAI KA2 REAL KA3 KA4 KA5 REAL KV KV1 KV2 REAL KV3 KV4 KV5 REAL ATTLTT(5) ATTLMT...ELSEIF C T.LE.TSTG1 ) THEN KA = KA2 KV = KV2 ELSEIF C T.LE.T5 ) THEN KA - KA3 KV = KV3 ELSEIF ( T.LE.T2S ) THEN KA = KA4 NV = KV4 ELSE KA = KA5 KV

  3. Kv1.5 in the Immune System: the Good, the Bad, or the Ugly?

    PubMed Central

    Felipe, Antonio; Soler, Concepció; Comes, Núria

    2010-01-01

    For the last 20 years, knowledge of the physiological role of voltage-dependent potassium channels (Kv) in the immune system has grown exponentially. Leukocytes express a limited repertoire of Kv channels, which contribute to the membrane potential. These proteins are involved in the immune response and are therefore considered good pharmacological targets. Although there is a clear consensus about the physiological relevance of Kv1.3, the expression and the role of Kv1.5 are controversial. However, recent reports indicate that certain heteromeric Kv1.3/Kv1.5 associations may provide insight on Kv1.5. Here, we summarize what is known about this issue and highlight the role of Kv1.5 partnership interactions that could be responsible for this debate. The Kv1.3/Kv1.5 heterotetrameric composition of the channel and their possible differential associations with accessory regulatory proteins warrant further investigation. PMID:21423392

  4. Extended defects in 4H-silicon carbide homoepitaxial layers

    NASA Astrophysics Data System (ADS)

    Zhang, Xuan

    The purpose of this thesis is to study the structure of extended defects in 4H-SIC homoepitaxial layers, and to identify their nucleation mechanisms. Characteristics of basal plane dislocations in 4H-SiC epilayers were investigated in a comprehensive manner, including their morphologies, Burgers' vectors, positions, and correlation with the extended defects propagating from the substrate. Plan-view transmission x-ray topography was the major characterization technique used in this study. Complementary data was obtained by KOH etching and optical microscopy. Trace of glide was detected on every basal plane dislocation in the entire 3-inch epilayer. In the center area of the epi-wafer, the glide can extend to macroscopic distance and form edge-type dislocations at the epilayer/surface interface. During the motion, dislocation half loop arrays were found to nucleate at the growth front. The magnitude of the resolved shear stress was estimated based on the radius of curvature of the dislocation lines. It surpassed the critical resolved shear stress at the epitaxial growth temperature. The stress was identified to be compressive in the epilayer. Its origin was studied. Nitrogen-doping-difference-induced misfit strain was excluded as the source of the stress. The structures of two morphological defects, 'carrots' and 'arrows', were studied. Cross-section x-ray topography was used to image the structure of carrot defect in whole. The defect was found to nucleate at the epilayer/substrate interface on a threading screw dislocation propagating from the substrate. Its structure was mainly composed of a prismatic stacking fault and a Frank-type basal plane stacking fault. The arrow defect was found to be produced by a spheroid shape inclusion in the volume of the epilayer. Zone axis diffraction pattern under transmission electron microscope identified the nature of the inclusion as 3C-SIC. It was determined to nucleate at the substrate surface contaminations.

  5. A population-based study of KCNH7 p.Arg394His and bipolar spectrum disorder.

    PubMed

    Strauss, Kevin A; Markx, Sander; Georgi, Benjamin; Paul, Steven M; Jinks, Robert N; Hoshi, Toshinori; McDonald, Ann; First, Michael B; Liu, Wencheng; Benkert, Abigail R; Heaps, Adam D; Tian, Yutao; Chakravarti, Aravinda; Bucan, Maja; Puffenberger, Erik G

    2014-12-01

    We conducted blinded psychiatric assessments of 26 Amish subjects (52 ± 11 years) from four families with prevalent bipolar spectrum disorder, identified 10 potentially pathogenic alleles by exome sequencing, tested association of these alleles with clinical diagnoses in the larger Amish Study of Major Affective Disorder (ASMAD) cohort, and studied mutant potassium channels in neurons. Fourteen of 26 Amish had bipolar spectrum disorder. The only candidate allele shared among them was rs78247304, a non-synonymous variant of KCNH7 (c.1181G>A, p.Arg394His). KCNH7 c.1181G>A and nine other potentially pathogenic variants were subsequently tested within the ASMAD cohort, which consisted of 340 subjects grouped into controls subjects and affected subjects from overlapping clinical categories (bipolar 1 disorder, bipolar spectrum disorder and any major affective disorder). KCNH7 c.1181G>A had the highest enrichment among individuals with bipolar spectrum disorder (χ(2) = 7.3) and the strongest family-based association with bipolar 1 (P = 0.021), bipolar spectrum (P = 0.031) and any major affective disorder (P = 0.016). In vitro, the p.Arg394His substitution allowed normal expression, trafficking, assembly and localization of HERG3/Kv11.3 channels, but altered the steady-state voltage dependence and kinetics of activation in neuronal cells. Although our genome-wide statistical results do not alone prove association, cumulative evidence from multiple independent sources (parallel genome-wide study cohorts, pharmacological studies of HERG-type potassium channels, electrophysiological data) implicates neuronal HERG3/Kv11.3 potassium channels in the pathophysiology of bipolar spectrum disorder. Such a finding, if corroborated by future studies, has implications for mental health services among the Amish, as well as development of drugs that specifically target HERG3/Kv11.3.

  6. A population-based study of KCNH7 p.Arg394His and bipolar spectrum disorder

    PubMed Central

    Strauss, Kevin A.; Markx, Sander; Georgi, Benjamin; Paul, Steven M.; Jinks, Robert N.; Hoshi, Toshinori; McDonald, Ann; First, Michael B.; Liu, Wencheng; Benkert, Abigail R.; Heaps, Adam D.; Tian, Yutao; Chakravarti, Aravinda; Bucan, Maja; Puffenberger, Erik G.

    2014-01-01

    We conducted blinded psychiatric assessments of 26 Amish subjects (52 ± 11 years) from four families with prevalent bipolar spectrum disorder, identified 10 potentially pathogenic alleles by exome sequencing, tested association of these alleles with clinical diagnoses in the larger Amish Study of Major Affective Disorder (ASMAD) cohort, and studied mutant potassium channels in neurons. Fourteen of 26 Amish had bipolar spectrum disorder. The only candidate allele shared among them was rs78247304, a non-synonymous variant of KCNH7 (c.1181G>A, p.Arg394His). KCNH7 c.1181G>A and nine other potentially pathogenic variants were subsequently tested within the ASMAD cohort, which consisted of 340 subjects grouped into controls subjects and affected subjects from overlapping clinical categories (bipolar 1 disorder, bipolar spectrum disorder and any major affective disorder). KCNH7 c.1181G>A had the highest enrichment among individuals with bipolar spectrum disorder (χ2 = 7.3) and the strongest family-based association with bipolar 1 (P = 0.021), bipolar spectrum (P = 0.031) and any major affective disorder (P = 0.016). In vitro, the p.Arg394His substitution allowed normal expression, trafficking, assembly and localization of HERG3/Kv11.3 channels, but altered the steady-state voltage dependence and kinetics of activation in neuronal cells. Although our genome-wide statistical results do not alone prove association, cumulative evidence from multiple independent sources (parallel genome-wide study cohorts, pharmacological studies of HERG-type potassium channels, electrophysiological data) implicates neuronal HERG3/Kv11.3 potassium channels in the pathophysiology of bipolar spectrum disorder. Such a finding, if corroborated by future studies, has implications for mental health services among the Amish, as well as development of drugs that specifically target HERG3/Kv11.3. PMID:24986916

  7. Impulsive Phase Transport. Chapter 3,

    DTIC Science & Technology

    1988-03-30

    3-38 3.3.1.1 Lyman -a Charge-Exchange Emission...HXRBS ISEE-3 26-490 KEV 38-70 KEV I 2- 1-UL8A cL 27 - r- Jr L" / N, " I 26 IrI ISEE-3 E 0 SMM/HXRBS ISEE-3 ISEE-3 CL 2-3KV 31-551 KEV 26-47 KEV 78-154 KEV...the Spitzer (1962) coefficient of thermal con-and T. the electron temperature (Emslie 1980). and hence ductivity and Les the stopping distance of the

  8. The Use of Various Failure Criteria as Applied to High Speed Wear

    DTIC Science & Technology

    2011-12-01

    to the analytical model developed in this thesis. This conversion method and application of Wolfson’s data is described in greater detail in Section...Grüneisen EOS, and the tabular Sesame EOS. Vanderhyde’s [34] research provides insight to the two EOS models internal to CTH. Much of the infor- mation...2.20) Γ = 3Kvα Cv (2.21) 2.8.2.2 Sesame EOS. CTH also provides the Sesame equation of state. The Sesame EOS is a set of tabular data collected

  9. Kolaviron was protective against sodium azide (NaN3) induced oxidative stress in the prefrontal cortex.

    PubMed

    Olajide, Olayemi J; Enaibe, Bernard U; Bankole, Oluwamolakun O; Akinola, Oluwole B; Laoye, Babafemi J; Ogundele, Olalekan M

    2016-02-01

    Kolaviron is a phytochemical isolated from Garcina kola (G. kola); a common oral masticatory agent in Nigeria (West Africa). It is a bioflavonoid used--as an antiviral, anti-inflammatory and antioxidant--in relieving the symptoms of several diseases and infections. In this study we have evaluated the neuroprotective and regenerative effect of kolaviron in neurons of the prefrontal cortex (Pfc) before or after exposure to sodium azide (NaN3) induced oxidative stress. Separate groups of animals were treated as follows; kolaviron (200 mg/Kg) for 21 days; kolaviron (200 mg/Kg for 21 days) followed by NaN3 treatment (20 mg/Kg for 5 days); NaN3 treatment (20 mg/Kg for 5 days) followed by kolaviron (200 mg/Kg for 21 days); 1 ml of corn-oil (21 days-vehicle); NaN3 treatment (20 mg/Kg for 5 days). Exploratory activity associated with Pfc function was assessed in the open field test (OFT) following which the microscopic anatomy of the prefrontal cortex was examined in histology (Haematoxylin and Eosin) and antigen retrieval Immunohistochemistry to show astroglia activation (GFAP), neuronal metabolism (NSE), cytoskeleton (NF) and cell cycle dysregulation (p53). Subsequently, we quantified the level of Glucose-6-phosphate dehydrogenase (G6PDH) and lactate dehydrogenase (LDH) in the brain tissue homogenate as a measure of stress-related glucose metabolism. Kolaviron (Kv) and Kolaviron/NaN3 treatment caused no prominent change in astroglia density and size while NaN3 and NaN3/Kv induced astroglia activation and scar formation (astrogliosis) in the Pfc when compared with the control. Similarly, Kolaviron and Kv/NaN3 did not alter NSE expression (glucose metabolism) while NaN3 and NaN3/Kv treatment increased cortical NSE expression; thus indicating stress related metabolism. Further studies on enzymes of glucose metabolism (G6PDH and LDH) showed that NaN3 increased LDH while kolaviron reduced LDH in the brain tissue homogenate (P < 0.001). In addition kolaviron treatment before (P

  10. 78 FR 5828 - Agency Information Collection Activities: Petition To Classify Orphan as an Immediate Relative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-28

    ... uses Form I-600 to determine whether a child alien is an eligible orphan. Form I-600A is used to... adult member (age 18 and older), who lives in the home of the prospective adoptive parent(s), except...

  11. 77 FR 65709 - Agency Information Collection Activities: Petition To Classify Orphan as an Immediate Relative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-30

    ... uses Form I-600 to determine whether a child alien is an eligible orphan. Form I-600A is used to... adult member (age 18 and older), who lives in the home of the prospective adoptive parent(s), except...

  12. Guidance, Navigation and Control. Digital Emulation Technology Laboratory. Volume 3. Part 2. Task 3. Special Studies

    DTIC Science & Technology

    1991-09-27

    kal, ka2, ka3, ka4, ka5IREAL kv, kvl, kv2, kv3 , kv4, kv5 REAL pm(3), psier, thter, attlm DATA kal/.0015/, ka2/.0015/, ka3/.0013/, ka4I.0ll/, ka5/.0045...DATA kvlI.00013/, kv2I.000131, kv3 /O.O/, kv4IO.0/, kv5/0.O/IDATA tc/0.751, ts/14.5/, t5/46.0/, t2s/58.21, tcd & /60.2/ DATA iminsf/0/, vwlim/10.0...THEN ka = ka3Ikv = kv3 ELSEIF (t .LE. t2s) THEN ka = ka4 kv = kv4I ELSE ka = ka5 kv = kv5 ENDI FI c launch steering mode IF (t .LE. tc) THEN CALL

  13. Word Frequency Analysis. MOS: 13B. Skill Levels 1 & 2.

    DTIC Science & Technology

    1981-05-01

    I T-( 1 2 TRP . KSI - ’ 1LS JC7 4 f %A i J’.l.’ 4 ’T T 1 7A’,"ISS’’N ,JCF 64 -rV: 2~tN -!. :7 I T~ -, .TATICSi 1 ~~(.G .HLIOT9 ~~ 2, j ’V INTC LTK3...S26v6 2I’ 2 P~ jcjAT2r3 ’ 2 P,...12 R~ C42 F!AJN 3 :KV1S j i L Q2 S!EC)- . 2 P1E FZCA 2 1. E𔃻 A L 2 o-, O cs 2T I :W _ 2 F’r ’’ * - ’ :’LT 2 PFLSL a2

  14. Action potential processing in a detailed Purkinje cell model reveals a critical role for axonal compartmentalization

    PubMed Central

    Masoli, Stefano; Solinas, Sergio; D'Angelo, Egidio

    2015-01-01

    The Purkinje cell (PC) is among the most complex neurons in the brain and plays a critical role for cerebellar functioning. PCs operate as fast pacemakers modulated by synaptic inputs but can switch from simple spikes to complex bursts and, in some conditions, show bistability. In contrast to original works emphasizing dendritic Ca-dependent mechanisms, recent experiments have supported a primary role for axonal Na-dependent processing, which could effectively regulate spike generation and transmission to deep cerebellar nuclei (DCN). In order to account for the numerous ionic mechanisms involved (at present including Nav1.6, Cav2.1, Cav3.1, Cav3.2, Cav3.3, Kv1.1, Kv1.5, Kv3.3, Kv3.4, Kv4.3, KCa1.1, KCa2.2, KCa3.1, Kir2.x, HCN1), we have elaborated a multicompartmental model incorporating available knowledge on localization and gating of PC ionic channels. The axon, including initial segment (AIS) and Ranvier nodes (RNs), proved critical to obtain appropriate pacemaking and firing frequency modulation. Simple spikes initiated in the AIS and protracted discharges were stabilized in the soma through Na-dependent mechanisms, while somato-dendritic Ca channels contributed to sustain pacemaking and to generate complex bursting at high discharge regimes. Bistability occurred only following Na and Ca channel down-regulation. In addition, specific properties in RNs K currents were required to limit spike transmission frequency along the axon. The model showed how organized electroresponsive functions could emerge from the molecular complexity of PCs and showed that the axon is fundamental to complement ionic channel compartmentalization enabling action potential processing and transmission of specific spike patterns to DCN. PMID:25759640

  15. Effects of Adding Nanoparticles on Boiling and Condensing Heat Transfer inside a horizontal round tube

    NASA Astrophysics Data System (ADS)

    Sheikholeslami, Mohsen; Sadoughi, Mohammadkazem; Shariatmadar, Hamed; Akhavan-Behabadi, Mohammad Ali

    2015-11-01

    An experimental investigation is performed on heat transfer evaluation of a nano-refrigerant flow during condensation and evaporation inside a horizontal round tube. Experiments are carried out for three working fluid types including: i) pure refrigerant (R600a); ii) refrigerant/lubricant (R600a/oil); and iii) nano-refrigerant: refrigerant/lubricant/nanoparticles (R600a/oil/CuO). Nanoparticles are added to the lubricant and their mixture is mixed with pure refrigerant. Therefore, nano-refrigerants (R600a/oil/CuO) are prepared by dispersing CuO nanoparticles with different fractions of 0.5%, 1% and 1.5% in the baseline mixture (R600a/oil). Effects of different factors including vapor quality, mass flux, and nanoparticles on the heat transfer coefficient are examined for both of condensation and evaporation flows, separately. The results shows that maximum heat transfer augmentation of 79% and 83% are achieved by using the refrigerant/lubricant/nanoparticles mixture, in comparison with the pure refrigerant case in condensation and evaporation, respectively which are occurred for nano-refrigerant with 1.5% mass fraction in both of them.

  16. Open channel block of A-type, kv4.3, and delayed rectifier K+ channels, Kv1.3 and Kv3.1, by sibutramine.

    PubMed

    Kim, Sung Eun; Ahn, Hye Sook; Choi, Bok Hee; Jang, Hyun-Jong; Kim, Myung-Jun; Rhie, Duck-Joo; Yoon, Shin-Hee; Jo, Yang-Hyeok; Kim, Myung-Suk; Sung, Ki-Wug; Hahn, Sang June

    2007-05-01

    The effects of sibutramine on voltage-gated K+ channel (Kv)4.3, Kv1.3, and Kv3.1, stably expressed in Chinese hamster ovary cells, were investigated using the whole-cell patch-clamp technique. Sibutramine did not significantly decrease the peak Kv4.3 currents, but it accelerated the rate of decay of current inactivation in a concentration-dependent manner. This phenomenon was effectively characterized by integrating the total current over the duration of a depolarizing pulse to +40 mV. The IC50 value for the sibutramine block of Kv4.3 was 17.3 microM. Under control conditions, the inactivation of Kv4.3 currents could be fit to a biexponential function, and the time constants for the fast and slow components were significantly decreased after the application of sibutramine. The association (k+1) and dissociation (k-1) rate constants for the sibutramine block of Kv 4.3 were 1.51 microM-1s-1 and 27.35 s-1, respectively. The theoretical KD value, derived from k-1/k+1, yielded a value of 18.11 microM. The block of Kv4.3 by sibutramine displayed a weak voltage dependence, increasing at more positive potentials, and it was use-dependent at 2 Hz. Sibutramine did not affect the time course for the deactivating tail currents. Neither steady-state activation and inactivation nor the recovery from inactivation was affected by sibutramine. Sibutramine caused the concentration-dependent block of the Kv1.3 and Kv3.1 currents with an IC50 value of 3.7 and 32.7 microM, respectively. In addition, sibutramine reduced the tail current amplitude and slowed the deactivation of the tail currents of Kv1.3 and Kv3.1, resulting in a crossover phenomenon. These results indicate that sibutramine acts on Kv4.3, Kv1.3, and Kv3.1 as an open channel blocker.

  17. Molecular Expression and Pharmacological Evidence for a Functional Role of Kv7 Channel Subtypes in Guinea Pig Urinary Bladder Smooth Muscle

    PubMed Central

    Afeli, Serge A. Y.; Malysz, John; Petkov, Georgi V.

    2013-01-01

    Voltage-gated Kv7 (KCNQ) channels are emerging as essential regulators of smooth muscle excitability and contractility. However, their physiological role in detrusor smooth muscle (DSM) remains to be elucidated. Here, we explored the molecular expression and function of Kv7 channel subtypes in guinea pig DSM by RT-PCR, qRT-PCR, immunohistochemistry, electrophysiology, and isometric tension recordings. In whole DSM tissue, mRNAs for all Kv7 channel subtypes were detected in a rank order: Kv7.1~Kv7.2Kv7.3~Kv7.5Kv7.4. In contrast, freshly-isolated DSM cells showed mRNA expression of: Kv7.1~Kv7.2Kv7.5Kv7.3~Kv7.4. Immunohistochemical confocal microscopy analyses of DSM, conducted by using co-labeling of Kv7 channel subtype-specific antibodies and α-smooth muscle actin, detected protein expression for all Kv7 channel subtypes, except for the Kv7.4, in DSM cells. L-364373 (R-L3), a Kv7.1 channel activator, and retigabine, a Kv7.2-7.5 channel activator, inhibited spontaneous phasic contractions and the 10-Hz electrical field stimulation (EFS)-induced contractions of DSM isolated strips. Linopiridine and XE991, two pan-Kv7 (effective at Kv7.1-Kv7.5 subtypes) channel inhibitors, had opposite effects increasing DSM spontaneous phasic and 10 Hz EFS-induced contractions. EFS-induced DSM contractions generated by a wide range of stimulation frequencies were decreased by L-364373 (10 µM) or retigabine (10 µM), and increased by XE991 (10 µM). Retigabine (10 µM) induced hyperpolarization and inhibited spontaneous action potentials in freshly-isolated DSM cells. In summary, Kv7 channel subtypes are expressed at mRNA and protein levels in guinea pig DSM cells. Their pharmacological modulation can control DSM contractility and excitability; therefore, Kv7 channel subtypes provide potential novel therapeutic targets for urinary bladder dysfunction. PMID:24073284

  18. 7 CFR 58.43 - Fees for inspection, grading, and sampling.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... performed between 6:00 p.m. and 6:00 a.m., for the time required to perform the service calculated to the nearest 15-minute period, including the time required for preparation of certificates and reports and the travel time of the inspector or grader in connection with the performance of the service. A...

  19. 8 CFR 204.3 - Orphan cases under section 101(b)(1)(F) of the Act (non-Convention cases).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... home study preparer and/or fingerprint check. Advanced processing application means Form I-600A... study preparer means any party licensed or otherwise authorized under the law of the State of the orphan's proposed residence to conduct the research and preparation for a home study, including...

  20. 8 CFR 204.3 - Orphan cases under section 101(b)(1)(F) of the Act (non-Convention cases).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... home study preparer and/or fingerprint check. Advanced processing application means Form I-600A... study preparer means any party licensed or otherwise authorized under the law of the State of the orphan's proposed residence to conduct the research and preparation for a home study, including...

  1. 78 FR 16910 - Approval of Noise Compatibility Program for Cleveland-Hopkins International Airport, Cleveland, Ohio

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-19

    .... to 6:00 a.m.) departure runway; Wind and weather permitting, instruct arriving aircraft at night (10... provision of the Act to approve or disapprove the program within 180 days (other than the use of new or...-day period shall be deemed to be an approval of such program. A total of twenty-one proposed...

  2. Child Labor Amendments of 1991. Joint Hearing on S.600 To Amend the Fair Labor Standards Act of 1938 To Improve Enforcement of the Child Labor Provisions of Such Act, and for Other Purposes, before the Subcommittee on Labor and Subcommittee on Children, Family, Drugs and Alcoholism of the Committee on Labor and Human Resources. United States Senate, One Hundred Second Congress, First Session.

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. Senate Committee on Labor and Human Resources.

    A joint hearing was held to consider S. 600, a U.S. Senate bill designed to help educate the public about federal child labor laws and strengthen enforcement of child labor laws through an amendment to the Fair Labor Standards Act of 1938. Senator Howard M. Metzenbaum presided. The hearings were called because of sporadic enforcement of inadequate…

  3. International Symposium on Applied Military Psychology (17th) Held at Portuguese Air Force Base Number 1, Portugal on 18-22 May 1981.

    DTIC Science & Technology

    1981-07-01

    testing-cost tradeoff for making test policy decis;ions. Catlim and Barata (Portugal) presented some validity data whLch iE fairly consonant with the...Psicoteciico cia Forva Aex ea A. Gonalves Catalim Pago do Lumiar L600 A. Jose Sousa Barata Lisbon A. Martini Lopes Maria Reima Cassiano Carlos S. Goduiilio

  4. 26 CFR 31.3306(b)(1)-1 - $3,000 limitation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... trade or business of the M Corporation, namely, its engine manufacturing unit. Example 2. The R... employ of E. Employer E pays to C remuneration of $600 a month in each of the remaining five months of 1955, or total remuneration of $3,000. The entire $3,000 paid by E to employee C constitutes wages...

  5. 26 CFR 31.3306(b)(1)-1 - $3,000 limitation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... trade or business of the M Corporation, namely, its engine manufacturing unit. Example 2. The R... employ of E. Employer E pays to C remuneration of $600 a month in each of the remaining five months of 1955, or total remuneration of $3,000. The entire $3,000 paid by E to employee C constitutes wages...

  6. A calibration of detectors and gratings between 100 and 600 Angstroms

    NASA Technical Reports Server (NTRS)

    Samson, J. A. R.

    1975-01-01

    Calibration and efficiency measurements of magnetic electron multipliers, diffraction gratings, and photocathodes over the wavelength range 100 to 600 A are reported. For some of the measurements it was found necessary to use the synchrotron radiation from a storage ring. Measurements of grating efficiencies, the polarization produced by diffraction gratings, and the photoelectric yields of various photocathodes are included.

  7. The Relationship between Job Satisfaction and Selected Demographics and Teacher Retention

    ERIC Educational Resources Information Center

    Claybon, Karen M.

    2008-01-01

    According to the Texas State Board of Education in 2002, 60% of teachers in Texas classrooms quit the profession after only five years in the classroom. In 1998-99, Texas filled over 63,000 teaching positions. Most vacant positions resulted from existing teachers retiring (11,000) or leaving the profession (46,600). A recent study in Texas…

  8. NMR structure of inactivation gates from mammalian voltage-dependent potassium channels.

    PubMed

    Antz, C; Geyer, M; Fakler, B; Schott, M K; Guy, H R; Frank, R; Ruppersberg, J P; Kalbitzer, H R

    1997-01-16

    The electrical signalling properties of neurons originate largely from the gating properties of their ion channels. N-type inactivation of voltage-gated potassium (Kv) channels is the best-understood gating transition in ion channels, and occurs by a 'ball-and-chain' type mechanism. In this mechanism an N-terminal domain (inactivation gate), which is tethered to the cytoplasmic side of the channel protein by a protease-cleavable chain, binds to its receptor at the inner vestibule of the channel, thereby physically blocking the pore. Even when synthesized as a peptide, ball domains restore inactivation in Kv channels whose inactivation domains have been deleted. Using high-resolution nuclear magnetic resonance (NMR) spectroscopy, we analysed the three-dimensional structure of the ball peptides from two rapidly inactivating mammalian K. channels (Raw3 (Kv3.4) and RCK4 (Kv1.4)). The inactivation peptide of Raw3 (Raw3-IP) has a compact structure that exposes two phosphorylation sites and allows the formation of an intramolecular disulphide bridge between two spatially close cysteine residues. Raw3-IP exhibits a characteristic surface charge pattern with a positively charged, a hydrophobic, and a negatively charged region. The RCK4 inactivation peptide (RCK4-IP) shows a similar spatial distribution of charged and uncharged regions, but is more flexible and less ordered in its amino-terminal part.

  9. Serum- and glucocorticoid-inducible kinase 1 in the regulation of renal and extrarenal potassium transport.

    PubMed

    Lang, Florian; Vallon, Volker

    2012-02-01

    Serum- and glucocorticoid inducible-kinase 1 (SGK1) is an early gene transcriptionally upregulated by cell stress such as cell shrinkage and hypoxia and several hormones including gluco- and mineralocorticoids. It is activated by insulin and growth factors. SGK1 is a powerful regulator of a wide variety of channels and transporters. The present review describes the role of SGK1 in the regulation of potassium (K(+)) channels, K(+) transporters and K(+) homeostasis. SGK1-regulated K(+) channels include renal outer medullary K+ channel, Kv1.3, Kv1.5, KCNE1/KCNQ1, KCNQ4 and, via regulation of calcium (Ca(2+)) entry, Ca(2+)-sensitive K(+) channels. SGK1-sensitive transporters include sodium-potassium-chloride cotransporter 2 and sodium/potassium-adenosine triphosphatase. SGK1-dependent regulation of K(+) channels and K(+) transport contributes to the stimulation of renal K(+) excretion following high K(+) intake, to insulin-induced cellular K(+) uptake and hypokalemia, to inhibition of insulin release by glucocorticoids, to stimulation of mast cell degranulation and gastric acid secretion, and to cardiac repolarization. Thus, SGK1 has a profound effect on K(+) homeostasis and on a multitude of K(+)-sensitive cellular functions.

  10. Automatic Control of Robot Motion.

    DTIC Science & Technology

    1987-12-01

    14.4,KT2=14.4,KT3=14.4,LI=.0001,L2=.0001,L3=.0001 PARAM BM1=0.04297,BM2=0.04297,BM3=0.04297,RO=0.5,LOAD=O.O PARAM KV1=0.1012,KV2=0.1012, KV3 =0.1012,T...VSAT, VSAT, K2 *X3 DOTE) C3 DDT=V3 *KG3 C3 DOT=INTGRL (0. 0, C3 DDT) C3=INTGRL(0. 0,C3DOT) CZ=C3*1 ./CF VM3-V3- KV3 -"CR3 DOT MP3=REALPL(0.0, L3/R3 ,VM3/R3...14.4,KT2=14.4,KT3=14.4,LI=.0001,L2=.0001,L3=.0001 .. PARAM BM1=0.04297,BM2=0.04297,BM3=0.04297,RO=0.5,LOAD=0.0 PARAM KV1=0.1012,KV2=0.1012, KV3 =0.1012,T

  11. State-dependent inactivation of the Kv3 potassium channel.

    PubMed Central

    Marom, S; Levitan, I B

    1994-01-01

    Inactivation of Kv3 (Kv1.3) delayed rectifier potassium channels was studied in the Xenopus oocyte expression system. These channels inactivate slowly during a long depolarizing pulse. In addition, inactivation accumulates in response to a series of short depolarizing pulses (cumulative inactivation), although no significant inactivation occurs within each short pulse. The extent of cumulative inactivation does not depend on the voltage during the depolarizing pulse, but it does vary in a biphasic manner as a function of the interpulse duration. Furthermore, the rate of cumulative inactivation is influenced by changing the rate of deactivation. These data are consistent with a model in which Kv3 channel inactivation is a state-dependent and voltage-independent process. Macroscopic and single channel experiments indicate that inactivation can occur from a closed (silent) state before channel opening. That is, channels need not open to inactivate. The transition that leads to the inactivated state from the silent state is, in fact, severalfold faster then the observed inactivation of current during long depolarizing pulses. Long pulse-induced inactivation appears to be slow, because its rate is limited by the probability that channels are in the open state, rather than in the silent state from which they can inactivate. External potassium and external calcium ions alter the rates of cumulative and long pulse-induced inactivation, suggesting that antagonistic potassium and calcium binding steps are involved in the normal gating of the channel. PMID:7948675

  12. FGF14 is a regulator of KCNQ2/3 channels.

    PubMed

    Pablo, Juan Lorenzo; Pitt, Geoffrey S

    2017-01-03

    KCNQ2/3 (Kv7.2/7.3) channels and voltage-gated sodium channels (VGSCs) are enriched in the axon initial segment (AIS) where they bind to ankyrin-G and coregulate membrane potential in central nervous system neurons. The molecular mechanisms supporting coordinated regulation of KCNQ and VGSCs and the cellular mechanisms governing KCNQ trafficking to the AIS are incompletely understood. Here, we show that fibroblast growth factor 14 (FGF14), previously described as a VGSC regulator, also affects KCNQ function and localization. FGF14 knockdown leads to a reduction of KCNQ2 in the AIS and a reduction in whole-cell KCNQ currents. FGF14 positively regulates KCNQ2/3 channels in a simplified expression system. FGF14 interacts with KCNQ2 at a site distinct from the FGF14-VGSC interaction surface, thus enabling the bridging of NaV1.6 and KCNQ2. These data implicate FGF14 as an organizer of channel localization in the AIS and provide insight into the coordination of KCNQ and VGSC conductances in the regulation of membrane potential.

  13. A potent and Kv1.3-selective analogue of the scorpion toxin HsTX1 as a potential therapeutic for autoimmune diseases

    NASA Astrophysics Data System (ADS)

    Rashid, M. Harunur; Huq, Redwan; Tanner, Mark R.; Chhabra, Sandeep; Khoo, Keith K.; Estrada, Rosendo; Dhawan, Vikas; Chauhan, Satendra; Pennington, Michael W.; Beeton, Christine; Kuyucak, Serdar; Norton, Raymond S.

    2014-03-01

    HsTX1 toxin, from the scorpion Heterometrus spinnifer, is a 34-residue, C-terminally amidated peptide cross-linked by four disulfide bridges. Here we describe new HsTX1 analogues with an Ala, Phe, Val or Abu substitution at position 14. Complexes of HsTX1 with the voltage-gated potassium channels Kv1.3 and Kv1.1 were created using docking and molecular dynamics simulations, then umbrella sampling simulations were performed to construct the potential of mean force (PMF) of the ligand and calculate the corresponding binding free energy for the most stable configuration. The PMF method predicted that the R14A mutation in HsTX1 would yield a > 2 kcal/mol gain for the Kv1.3/Kv1.1 selectivity free energy relative to the wild-type peptide. Functional assays confirmed the predicted selectivity gain for HsTX1[R14A] and HsTX1[R14Abu], with an affinity for Kv1.3 in the low picomolar range and a selectivity of more than 2,000-fold for Kv1.3 over Kv1.1. This remarkable potency and selectivity for Kv1.3, which is significantly up-regulated in activated effector memory cells in humans, suggest that these analogues represent valuable leads in the development of therapeutics for autoimmune diseases.

  14. Mechanism of functional interaction between potassium channel Kv1.3 and sodium channel NavBeta1 subunit

    PubMed Central

    Kubota, Tomoya; Correa, Ana M.; Bezanilla, Francisco

    2017-01-01

    The voltage-gated potassium channel subfamily A member 3 (Kv1.3) dominantly expresses on T cells and neurons. Recently, the interaction between Kv1.3 and NavBeta1 subunits has been explored through ionic current measurements, but the molecular mechanism has not been elucidated yet. We explored the functional interaction between Kv1.3 and NavBeta1 through gating current measurements using the Cut-open Oocyte Voltage Clamp (COVC) technique. We showed that the N-terminal 1–52 sequence of hKv1.3 disrupts the channel expression on the Xenopus oocyte membrane, suggesting a potential role as regulator of hKv1.3 expression in neurons and lymphocytes. Our gating currents measurements showed that NavBeta1 interacts with the voltage sensing domain (VSD) of Kv1.3 through W172 in the transmembrane segment and modifies the gating operation. The comparison between G-V and Q-V with/without NavBeta1 indicates that NavBeta1 may strengthen the coupling between hKv1.3-VSD movement and pore opening, inducing the modification of kinetics in ionic activation and deactivation. PMID:28349975

  15. Field Portable GC-MS Unit for Semi-Volatile Compound Analysis in Groundwater

    DTIC Science & Technology

    2011-06-01

    regulatory-approved analytical methods . The typical analysis and data reporting time at most analytical laboratories can be up to 45 days, which...as compared to HPLC analysis , for samples with high analyte concentrations. The cost savings of the field method were found to be $29,600 a year...that perform regulatory-approved analytical methods . The typical analysis and data reporting time at most analytical laboratories can be up to 45 days

  16. Experimental investigation of the performance of a single-stage auto-cascade refrigerator

    NASA Astrophysics Data System (ADS)

    Rui, Shengjun; Zhang, Hua; Zhang, Bohan; Wen, Dongsheng

    2016-01-01

    Auto-refrigerating cascade (ARC) systems possess many advantages comparing with traditional cascade refrigeration systems. This work proposed a novel ternary mixture, R600a/R23/R14, for ARC systems for 190 K applications. The performance of the ternary mixture and the influences of compositional ratio and bypass scheme were assessed in a modified domestic cooler. The results demonstrated the feasibility of the proposed R600a/R23/R14 ternary mixture as an environmental benign alternative for ARC systems. The performance varied little within a certain composition range and a mass ratio of 35/30/35 for R600a/R23/R14 mixture was recommended. It also showed that the two bypass schemes, which can regulate more effectively the refrigerant compositions, were better than the conventional hot-gas bypass approach. The variation of the evaporator temperature suggested the presence of local dryout at high heat loads (i.e., larger than the design value), which should be carefully prevented.

  17. Voltage-gated ion channel Kv4.3 is associated with Rap guanine nucleotide exchange factors and regulates angiotensin receptor type 1 signaling to small G-protein Rap.

    PubMed

    Potapova, Irina A; Cohen, Ira S; Doronin, Sergey V

    2007-09-01

    The voltage-gated potassium channel Kv4.3 was coexpressed with its beta-subunit Kv channel-interacting protein 2 and the angiotensin type 1 receptor in HEK-293 cells. Proteomic analysis of proteins coimmunoprecipitated with Kv4.3 revealed that Kv4.3 is associated with Rap guanine nucleotide exchange factors MR-GEF and EPAC-1. Previously, we demonstrated that Kv4.3 interacts with the angiotensin type 1 receptor in HE293 cells and cardiac myocytes. On the basis of this, we investigated the angiotensin type 1 receptor signaling to small G-proteins Ras and Rap-1 in the presence and absence of the Kv4.3-Kv channel-interacting protein 2 macromolecular complex. Ras activation was not significantly affected by coexpression of Kv4.3 and Kv channel-interacting protein 2. Ras exhibited a rapid activation-inactivation pattern with maximum activity at 2.5 min after addition of angiotensin II. In contrast, activation of Rap-1 was affected dramatically by coexpression of Kv4.3 and Kv channel-interacting protein 2 with the angiotensin type 1 receptor. In the absence of Kv4.3 and Kv channel-interacting protein 2, stimulation of the angiotensin type 1 receptor resulted in steady activation of Rap-1 that reached a plateau 25 min after addition of angiotensin II. In the presence of Kv4.3 and Kv channel-interacting protein 2, Rap-1 reaches a maximum activity 2.5 min after addition of angiotensin II and then deactivates rapidly, demonstrating a pattern of activation similar to that of Ras. Our findings show that Kv4.3 regulates angiotensin type 1 receptor signaling to the small G-protein Rap-1.

  18. Functional characterization of Kv channel beta-subunits from rat brain.

    PubMed Central

    Heinemann, S H; Rettig, J; Graack, H R; Pongs, O

    1996-01-01

    1. The potassium channel beta-subunit from rat brain, Kv beta 1.1, is known to induce inactivation of the delayed rectifier channel Kv1.1 and Kv1.4 delta 1-110. 2. Kv beta 1.1 was co-expressed in Xenopus oocytes with various other potassium channel alpha-subunits. Kv beta 1.1 induced inactivation in members of the Kv1 subfamily with the exception of Kv 1.6; no inactivation of Kv 2.1, Kv 3.4 delta 2-28 and Kv4.1 channels could be observed. 3. The second member of the beta-subunit subfamily, Kv beta 2, had a shorter N-terminal end, accelerated inactivation of the A-type channel Kv 1.4, but did not induce inactivation when co-expressed with delayed rectifiers of the Kv1 channel family. 4. To test whether this subunit co-assembles with Kv alpha-subunits, the N-terminal inactivating domains of Kv beta 1.1 and Kv beta 3 were spliced to the N-terminus of Kv beta 2. The chimaeric beta-subunits (beta 1/ beta 2 and beta 3/ beta 2) induced fast inactivation of several Kv1 channels, indicating that Kv beta 2 associates with these alpha-subunits. No inactivation was induced in Kv 1.3, Kv 1.6, Kv2.1 and Kv3.4 delta 2-28 channels. 5. Kv beta 2 caused a voltage shift in the activation threshold of Kv1.5 of about -10 mV, indicating a putative physiological role. Kv beta 2 had a smaller effect on Kv 1.1 channels. 6. Kv beta 2 accelerated the activation time course of Kv1.5 but had no marked effect on channel deactivation. PMID:8799886

  19. Functional characterization of Kv channel beta-subunits from rat brain.

    PubMed

    Heinemann, S H; Rettig, J; Graack, H R; Pongs, O

    1996-06-15

    1. The potassium channel beta-subunit from rat brain, Kv beta 1.1, is known to induce inactivation of the delayed rectifier channel Kv1.1 and Kv1.4 delta 1-110. 2. Kv beta 1.1 was co-expressed in Xenopus oocytes with various other potassium channel alpha-subunits. Kv beta 1.1 induced inactivation in members of the Kv1 subfamily with the exception of Kv 1.6; no inactivation of Kv 2.1, Kv 3.4 delta 2-28 and Kv4.1 channels could be observed. 3. The second member of the beta-subunit subfamily, Kv beta 2, had a shorter N-terminal end, accelerated inactivation of the A-type channel Kv 1.4, but did not induce inactivation when co-expressed with delayed rectifiers of the Kv1 channel family. 4. To test whether this subunit co-assembles with Kv alpha-subunits, the N-terminal inactivating domains of Kv beta 1.1 and Kv beta 3 were spliced to the N-terminus of Kv beta 2. The chimaeric beta-subunits (beta 1/ beta 2 and beta 3/ beta 2) induced fast inactivation of several Kv1 channels, indicating that Kv beta 2 associates with these alpha-subunits. No inactivation was induced in Kv 1.3, Kv 1.6, Kv2.1 and Kv3.4 delta 2-28 channels. 5. Kv beta 2 caused a voltage shift in the activation threshold of Kv1.5 of about -10 mV, indicating a putative physiological role. Kv beta 2 had a smaller effect on Kv 1.1 channels. 6. Kv beta 2 accelerated the activation time course of Kv1.5 but had no marked effect on channel deactivation.

  20. Molecular basis of voltage-dependent potassium currents in porcine granulosa cells.

    PubMed

    Mason, Diane E; Mitchell, Kathy E; Li, Yan; Finley, Melissa R; Freeman, Lisa C

    2002-01-01

    The major objective of this study was to elucidate the molecular bases for K(+) current diversity in porcine granulosa cells (GC). Two delayed rectifier K(+) currents with distinct electrophysiological and pharmacological properties were recorded from porcine GC by using whole-cell patch clamp: 1) a slowly activating, noninactivating current (I(Ks)) antagonized by clofilium, 293B, L-735,821, and L-768,673; and 2) an ultrarapidly activating, slowly inactivating current (I(Kur)) antagonized completely by clofilium and 4-aminopyridine and partially by tetraethylammonium, charybdotoxin, dendrotoxin, and kaliotoxin. The molecular identity of the K(+) channel genes underlying I(Ks) and I(Kur) was examined using reverse transcription-polymerase chain reaction and immunoblotting to detect K(+) channel transcripts and proteins. We found that GC could express multiple voltage-dependent K(+) (Kv) channel subunits, including KCNQ1, KCNE1, Kv1.1, Kv1.2, Kv1.3, Kv1.4, Kv1.5, Kv1.6, Kvbeta1.3, and Kvbeta2. Coimmunoprecipitation was used to establish the hetero-oligomeric nature of granulosa cell Kv channels. KCNE1 and KCNQ1 were coassociated in GC, and their expression coincided with the expression of I(Ks). Extensive coassociation of the various Kv alpha- and beta-subunits was also documented, suggesting that the diverse electrophysiological and pharmacological properties of I(Kur) currents may reflect variation in the composition and stoichiometry of the channel assemblies, as well as differences in post-translational modification of contributing Kv channel subunits. Our findings provide an essential background for experimental definition of granulosa K(+) channel function(s). It will be critical to define the functional roles of specific GC K(+) channels, because these proteins may represent either novel targets for assisted reproduction or potential sites of drug toxicity.

  1. The expression and regulation of depolarization-activated K+ channels in the insulin-secreting cell line INS-1.

    PubMed

    Su, J; Yu, H; Lenka, N; Hescheler, J; Ullrich, S

    2001-04-01

    The aim of the present study was to characterize depolarization-activated outward currents in insulin-secreting INS-1 cells and to investigate the role of K+ channels other than the KATP channels in the regulation of insulin release. Outward currents were inhibited by 4-aminopyridine (4-AP, 10 mmol/l), tetraethylammonium (TEA, 10 mmol/l) and tetrapentylammonium (TPeA, 100 mumol/l) by 55.1 +/- 3.8% (n = 3), 78.1 +/- 3.2% (n = 6) and 98.7 +/- 0.8% (n = 5), respectively. Margatoxin (5 nmol/l) and charybdotoxin (3 mumol/l) had no effect. 4-AP inhibited mainly a fast-activating, slowly inactivating current, whereas the TEA- and TPeA-sensitive current components were slowly activating and non-inactivating. Forskolin and the forskolin analogue 1,9-dideoxyforskolin, which does not stimulate adenylyl cyclase, also inhibited the outward current, suggesting a direct effect on the channels. Using reverse transcriptase polymerase chain reaction (RT/PCR). Kv channel mRNAs of Kv1.4, Kv1.5, Kv2.1, Kv2.2, Kv3.1 and Kv3.2 were detected whereas other Kv channels, Kv1.1, Kv1.2, Kv1.3, Kv1.6 and Kv3.4 were not detected. Insulin secretion in the presence of tolbutamide (100 mumol/l) was increased by 4-AP, TEA and TPeA by 65%, 41% and 150%, respectively. Basal secretion was not affected by these blockers. Our study reveals that the opening of voltage-dependent K+ channels negatively controls insulin secretion in depolarized cells, probably by shortening the action potential thus reducing Ca2+ influx.

  2. Coexpression of high-voltage-activated ion channels Kv3.4 and Cav1.2 in pioneer axons during pathfinding in the developing rat forebrain.

    PubMed

    Huang, Chia-Yi; Chu, Dachen; Hwang, Wei-Chao; Tsaur, Meei-Ling

    2012-11-01

    Precise axon pathfinding is crucial for establishment of the initial neuronal network during development. Pioneer axons navigate without the help of preexisting axons and pave the way for follower axons that project later. Voltage-gated ion channels make up the intrinsic electrical activity of pioneer axons and regulate axon pathfinding. To elucidate which channel molecules are present in pioneer axons, immunohistochemical analysis was performed to examine 14 voltage-gated ion channels (Kv1.1-Kv1.3, Kv3.1-Kv3.4, Kv4.3, Cav1.2, Cav1.3, Cav2.2, Nav1.2, Nav1.6, and Nav1.9) in nine axonal tracts in the developing rat forebrain, including the optic nerve, corpus callosum, corticofugal fibers, thalamocortical axons, lateral olfactory tract, hippocamposeptal projection, anterior commissure, hippocampal commissure, and medial longitudinal fasciculus. We found A-type K⁺ channel Kv3.4 in both pioneer axons and early follower axons and L-type Ca²⁺ channel Cav1.2 in pioneer axons and early and late follower axons. Spatially, Kv3.4 and Cav1.2 were colocalized with markers of pioneer neurons and pioneer axons, such as deleted in colorectal cancer (DCC), in most fiber tracts examined. Temporally, Kv3.4 and Cav1.2 were expressed abundantly in most fiber tracts during axon pathfinding but were downregulated beginning in synaptogenesis. By contrast, delayed rectifier Kv channels (e.g., Kv1.1) and Nav channels (e.g., Nav1.2) were absent from these fiber tracts (except for the corpus callosum) during pathfinding of pioneer axons. These data suggest that Kv3.4 and Cav1.2, two high-voltage-activated ion channels, may act together to control Ca²⁺ -dependent electrical activity of pioneer axons and play important roles during axon pathfinding.

  3. Functional and molecular differences between voltage-gated K+ channels of fast-spiking interneurons and pyramidal neurons of rat hippocampus.

    PubMed

    Martina, M; Schultz, J H; Ehmke, H; Monyer, H; Jonas, P

    1998-10-15

    We have examined gating and pharmacological characteristics of somatic K+ channels in fast-spiking interneurons and regularly spiking principal neurons of hippocampal slices. In nucleated patches isolated from basket cells of the dentate gyrus, a fast delayed rectifier K+ current component that was highly sensitive to tetraethylammonium (TEA) and 4-aminopyridine (4-AP) (half-maximal inhibitory concentrations <0.1 mM) predominated, contributing an average of 58% to the total K+ current in these cells. By contrast, in pyramidal neurons of the CA1 region a rapidly inactivating A-type K+ current component that was TEA-resistant prevailed, contributing 61% to the total K+ current. Both types of neurons also showed small amounts of the K+ current component mainly found in the other type of neuron and, in addition, a slow delayed rectifier K+ current component with intermediate properties (slow inactivation, intermediate sensitivity to TEA). Single-cell RT-PCR analysis of mRNA revealed that Kv3 (Kv3.1, Kv3.2) subunit transcripts were expressed in almost all (89%) of the interneurons but only in 17% of the pyramidal neurons. In contrast, Kv4 (Kv4.2, Kv4.3) subunit mRNAs were present in 87% of pyramidal neurons but only in 55% of interneurons. Selective block of fast delayed rectifier K+ channels, presumably assembled from Kv3 subunits, by 4-AP reduced substantially the action potential frequency in interneurons. These results indicate that the differential expression of Kv3 and Kv4 subunits shapes the action potential phenotypes of principal neurons and interneurons in the cortex.

  4. A novel crystallization method for visualizing the membrane localization of potassium channels.

    PubMed Central

    Lopatin, A N; Makhina, E N; Nichols, C G

    1998-01-01

    The high permeability of K+ channels to monovalent thallium (Tl+) ions and the low solubility of thallium bromide salt were used to develop a simple yet very sensitive approach to the study of membrane localization of potassium channels. K+ channels (Kir1.1, Kir2.1, Kir2.3, Kv2.1), were expressed in Xenopus oocytes and loaded with Br ions by microinjection. Oocytes were then exposed to extracellular thallium. Under conditions favoring influx of Tl+ ions (negative membrane potential under voltage clamp, or high concentration of extracellular Tl+), crystals of TlBr, visible under low-power microscopy, formed under the membrane in places of high density of K+ channels. Crystals were not formed in uninjected oocytes, but were formed in oocytes expressing as little as 5 microS K+ conductance. The number of observed crystals was much lower than the estimated number of functional channels. Based on the pattern of crystal formation, K+ channels appear to be expressed mostly around the point of cRNA injection when injected either into the animal or vegetal hemisphere. In addition to this pseudopolarized distribution of K+ channels due to localized microinjection of cRNA, a naturally polarized (animal/vegetal side) distribution of K+ channels was also frequently observed when K+ channel cRNA was injected at the equator. A second novel "agarose-hemiclamp" technique was developed to permit direct measurements of K+ currents from different hemispheres of oocytes under two-microelectrode voltage clamp. This technique, together with direct patch-clamping of patches of membrane in regions of high crystal density, confirmed that the localization of TlBr crystals corresponded to the localization of functional K+ channels and suggested a clustered organization of functional channels. With appropriate permeant ion/counterion pairs, this approach may be applicable to the visualization of the membrane distribution of any functional ion channel. PMID:9591643

  5. Alterations of voltage-dependent K(+) channels in the mesenteric artery during the early and chronic phases of diabetes.

    PubMed

    Hong, Da Hye; Li, Hongliang; Kim, Hye Won; Kim, Han Sol; Son, Youn Kyoung; Yang, Se-Ran; Park, Jeong-Ran; Ha, Kwon-Soo; Han, Eun-Taek; Hong, Seok-Ho; Firth, Amy L; Na, Sung Hun; Park, Won Sun

    2016-09-01

    This study investigated the alteration of voltage-dependent K(+) (Kv) channels in mesenteric arterial smooth muscle cells from control (Long-Evans Tokushima Otsuka [LETO]) and diabetic (Otsuka Long-Evans Tokushima Fatty [OLETF]) rats during the early and chronic phases of diabetes. We demonstrated alterations in the mesenteric Kv channels during the early and chronic phase of diabetes using the patch-clamp technique, the arterial tone measurement system, and RT-PCR in Long-Evans Tokushima (LETO; for control) and Otsuka Long-Evans Tokushima Fatty (OLETF; for diabetes) type 2 diabetic model rats. In the early phase of diabetes, the amplitude of mesenteric Kv currents induced by depolarizing pulses was greater in OLETF rats than in LETO rats. The contractile response of the mesenteric artery induced by the Kv inhibitor, 4-aminopyridine (4-AP), was also greater in OLETF rats. The expression of most Kv subtypes- including Kv1.1, Kv1.2, Kv1.4, Kv1.5, Kv1.6, Kv2.1, Kv3.2, Kv4.1, Kv4.3, Kv5.1, Kv6.2, Kv8.1, Kv9.3, and Kv10.1-were increased in mesenteric arterial smooth muscle from OLETF rats compared with LETO rats. However, in the chronic phase of diabetes, the Kv current amplitude did not differ between LETO and OLETF rats. In addition, the 4-AP-induced contractile response of the mesenteric artery and the expression of Kv subtypes did not differ between the two groups. The increased Kv current amplitude and Kv channel-related contractile response were attributable to the increase in Kv channel expression during the early phase of diabetes. The increased Kv current amplitude and Kv channel-related contractile response were reversed during the chronic phase of diabetes.

  6. The contribution of Kv2.2-mediated currents decreases during the postnatal development of mouse dorsal root ganglion neurons.

    PubMed

    Regnier, Glenn; Bocksteins, Elke; Van de Vijver, Gerda; Snyders, Dirk J; van Bogaert, Pierre-Paul

    2016-03-01

    Delayed rectifier voltage-gated K(+)(Kv) channels play an important role in the regulation of the electrophysiological properties of neurons. In mouse dorsal root ganglion (DRG) neurons, a large fraction of the delayed rectifier current is carried by both homotetrameric Kv2 channels and heterotetrameric channels consisting of Kv2 and silent Kv (KvS) subunits (i.e., Kv5-Kv6 and Kv8-Kv9). However, little is known about the contribution of Kv2-mediated currents during the postnatal development ofDRGneurons. Here, we report that the Stromatoxin-1 (ScTx)-sensitive fraction of the total outward K(+)current (IK) from mouseDRGneurons gradually decreased (~13%,P < 0.05) during the first month of postnatal development. Because ScTx inhibits both Kv2.1- and Kv2.2-mediated currents, this gradual decrease may reflect a decrease in currents containing either subunit. However, the fraction of Kv2.1 antibody-sensitive current that only reflects the Kv2.1-mediated currents remained constant during that same period. These results suggested that the fractional contribution of Kv2.2-mediated currents relative toIKdecreased with postnatal age. SemiquantitativeRT-PCRanalysis indicated that this decrease can be attributed to developmental changes in Kv2.2 expression as themRNAlevels of the Kv2.2 subunit decreased gradually between 1 and 4 weeks of age. In addition, we observed age-dependent fluctuations in themRNAlevels of the Kv6.3, Kv8.1, Kv9.1, and Kv9.3 subunits. These results support an important role of both Kv2 and KvS subunits in the postnatal maturation ofDRGneurons.

  7. Postnatal development of A-type and Kv1- and Kv2-mediated potassium channel currents in neocortical pyramidal neurons

    PubMed Central

    Guan, Dongxu; Horton, Leslie R.; Armstrong, William E.

    2011-01-01

    Potassium channels regulate numerous aspects of neuronal excitability, and several voltage-gated K+ channel subunits have been identified in pyramidal neurons of rat neocortex. Previous studies have either considered the development of outward current as a whole or divided currents into transient, A-type and persistent, delayed rectifier components but did not differentiate between current components defined by α-subunit type. To facilitate comparisons of studies reporting K+ currents from animals of different ages and to understand the functional roles of specific current components, we characterized the postnatal development of identified Kv channel-mediated currents in pyramidal neurons from layers II/III from rat somatosensory cortex. Both the persistent/slowly inactivating and transient components of the total K+ current increased in density with postnatal age. We used specific pharmacological agents to test the relative contributions of putative Kv1- and Kv2-mediated currents (100 nM α-dendrotoxin and 600 nM stromatoxin, respectively). A combination of voltage protocol, pharmacology, and curve fitting was used to isolate the rapidly inactivating A-type current. We found that the density of all identified current components increased with postnatal age, approaching a plateau at 3–5 wk. We found no significant changes in the relative proportions or kinetics of any component between postnatal weeks 1 and 5, except that the activation time constant for A-type current was longer at 1 wk. The putative Kv2-mediated component was the largest at all ages. Immunocytochemistry indicated that protein expression for Kv4.2, Kv4.3, Kv1.4, and Kv2.1 increased between 1 wk and 4–5 wk of age. PMID:21451062

  8. Smart portable electrophoresis instrument based on multipurpose microfluidic chips with electrochemical detection.

    PubMed

    Fernández-la-Villa, Ana; Sánchez-Barragán, Dámaso; Pozo-Ayuso, Diego F; Castaño-Álvarez, Mario

    2012-09-01

    A second generation of a battery-powered portable electrophoresis instrument for the use of ME with electrochemical detection was developed. As the first-generation, the main unit of the instrument (150 mm × 165 mm × 95 mm) consists of four-outputs high-voltage power supply (HVPS) with maximum voltage of 3 KV and acquisition system (bipotentiostat) containing 2-channels for dual electrochemical detection. A new reusable microfluidic platform was designed in order to incorporate the microchips with the portable instrument. In this case, the platform is integrated to the main unit of the instrument so that it is not necessary to have any external cable for the interconnection of both parts, making the use of the complete system easier. The new platform contains all the electrical connections for the HVPS and bipotentiostat, as well as fluidic ports for driving the solutions. The microfluidic electrophoresis instrument is controlled by means of a user-friendly interface from a computer. The possibility of wireless connection (Bluetooth®) allows the use of the instrument without any external cable improving the portability. Therefore, the second generation brings a more compact and integrated electrophoresis instrument for "in situ" applications using microfluidic chips in an easy way. The performance of the electrophoresis system was initially evaluated using single- and dual-channel SU-8/Pyrex microchips with different models of integrated electrodes including microelectrodes and interdigitated arrays. The method was tested in different analytical applications such as separation of neurotransmitters, chlorophenols, purine derivatives, vitamins, polyphenolic acids, and flavones.

  9. Using natural refrigerants (hydrocarbons) in air conditioning systems

    SciTech Connect

    Mathur, G.D.

    1998-07-01

    Refrigerant 134a has emerged as the new refrigerant for the automotive and commercial A/C industry that has a zero ozone depleting potential (ODP) value. However, R-134a's greenhouse warming potential (GWP) is relatively high among the newly developed hydroflourocarbons (HFCs) which seems to be an obstacle for the furtherance of the use of R-134a, especially in European countries. Hence, many countries are looking for other refrigerants that do not contribute to global warming. There are many refrigerants that are currently available naturally. Examples of the so called natural refrigerants are: ammonia, carbon dioxide, hydrocarbons, water, helium, air, etc. Hydrocarbons are receiving attention these days as their thermodynamic and thermophysical properties are similar to that of R-12 and R-134a. Hydrocarbons are highly flammable that have zero ODP and negligible GWP. In Europe, some countries have started using hydrocarbons for refrigerators, freezers, automobiles, and for commercial applications like supermarkets. Currently, limited information is available in the open literature on the performance and design of the air conditioning and refrigeration systems using the hydrocarbons. Most of the work reported in the literature on the hydrocarbon refrigerants has been conducted by the researchers in Europe and Australia. In the United States, due to the product liability, the manufacturers have not been receptive to the idea of using hydrocarbons as the refrigerants. In this paper, the author has simulated the thermodynamic performance of a typical air conditioning system using hydrocarbons. The performance of the air conditioning system has been simulated by using Propane (R-290) and Isobutane (R-600a) as the working fluids. REFPROP computer program developed by NIST has been used to determine the thermodynamic properties for R-290 and R-600a. The author has also presented the single phase (liquid and vapor), pool boiling, two-phase, dry- out region, and

  10. Siloxane containing addition polyimides. II - Acetylene terminated polyimides

    NASA Technical Reports Server (NTRS)

    Maudgal, S.; St. Clair, T. L.

    1984-01-01

    Acetylene terminated polyimide oligomers having a range of molecular weights have been synthesized by reacting bis (gamma-aminopropyl) tetramethyldisiloxane, aminophenylacetylene and 3, 3', 4, 4' benzophenonetetracarboxylic dianhydride in different molar ratios. The prepolymers were isolated and characterized for melt flow and cure properties. They show promise as adhesives for bonding titanium to titanium and as matrix resins for graphite cloth reinforced composites. The most promising system has been blended in varying proportions with Thermid 600, a commercially available acetylene terminated polyimide oligomer, and the mixtures have been tested for application as composite matrix resins.

  11. D/B/F 98: Final Report Of the AIAA Student Aircraft Design, Build & Fly Competition

    DTIC Science & Technology

    2007-11-02

    level flight speed, and turning performance around the pylons. Size and type of electric motor(s): the principal trade here was between ferrite ...output of the motor(s) to be installed into the competition aircraft. The propulsion team looked at the performance available from Astro ferrite , Astro...Ü o < T3 o o * to a> ɘ « OJ en (0 « c «! ്" &#600 a. CO CD ɛ> c ’a> >» CO sm c o CO to <n .o CO N co > a. o a

  12. Development of radiation tolerant components for the Quench Protection System at CERN

    NASA Astrophysics Data System (ADS)

    Bitterling, O.; Denz, R.; Steckert, J.; Uznanski, S.

    2016-01-01

    This paper describes the results of irradiation campaigns with the high resolution Analog to Digital Converter (ADC) ADS1281. This ADC will be used as part of a revised quench detection circuit for the 600 A corrector magnets at the CERN Large Hadron Collider (LHC) . To verify the radiation tolerance of the ADC an irradiation campaign using a proton beam, applying doses up to 3,4 kGy was conducted. The resulting data and an analysis of the found failure modes is discussed in this paper. Several mitigation measures are described that allow to reduce the error rate to levels acceptable for operation as part of the LHC QPS.

  13. Properties of TiN obtained by N2/plus/-implantation on Ti-coated Si wafers

    NASA Astrophysics Data System (ADS)

    Armigliato, A.; Celotti, G.; Garulli, A.; Guerri, S.; Lotti, R.; Ostoja, P.; Summonte, C.

    1982-09-01

    Titanium nitride films have been prepared by implanting 3.4 x 10 to the 17th/sg cm N2(plus) ions in 600-A-thick titanium layers deposited on silicon single crystals. Unlike the films obtained by evaporation or sputtering, both low electrical resistivity and fairly good optical properties were found even in the as-implanted samples. Moreover, thermal treatments up to 700 C performed both in vacuum and H2 atmosphere resulted in a further improvement of the overall films characteristics. This opens interesting perspectives of applications for TiN as a transparent (antireflective) conducting material in photovoltaic field, which are presently being investigated.

  14. Dermal, Eye and Oral Toxicological Evaluations. Phase IV Report with Disperse Red 11, Disperse Blue 3, Solvent Red 1, and Red and Violet Mixtures

    DTIC Science & Technology

    1986-04-01

    assure that any problems found during Quality Assurance,inspections or audits were corrected, And if necessary, their effect on the study documented...cleaned daily and the cages were cleaned and sanitized as specified in ABC SOP’s. Urine and feces fell through the wire mesh floor onto animal caqing...the ’ ’ raw data and were not considered to have effected the outcome of .the studies.’•’."The animal rooms were lighted from approximately 6:00 a.m

  15. Imaging extreme ultraviolet spectrometer employing a single toroidal diffraction grating - The initial evaluation

    NASA Technical Reports Server (NTRS)

    Huber, M. C. E.; Timothy, J. G.; Morgan, J. S.; Lemaitre, G.; Tondello, G.

    1988-01-01

    The design and test results of a high-efficiency EUV imaging spectrometer employing a concave toroidal grating which is illuminated at normal incidence in a Rowland circle mounting and has only one reflecting surface are discussed. Photographic tests and initial photoelectric tests with a two-dimensional pulse-counting detector system demonstrate the excellent image quality of the grating at wavelengths near 600 A. Applications of the spectrometer for the study of nonsolar objects and solar regions (including the chromosphere, transition region, and corona) are considered.

  16. The technique flows of target detection using thermal infrared hyperspectral remote sensing

    NASA Astrophysics Data System (ADS)

    Wu, Wen Huan; Yu, Hong; Huang, Shu Tao

    2016-10-01

    In this work, the workflow of airborne thermal infrared hyperspectral technology in the actual application process is reviewed. Using the Thermal Airborne Spectrographic Imager (TASI-600), a hyperspectral thermal infrared imager manufactured by ITRES Research Limited as a case study, the work process including instrument calibration, collecting the region information of interest, data processing and analysis is elaborated. The value and effect using thermal infrared data obtained through TASI-600 is demonstrated. This work provides ideas and references for further study and investigation on the application of airborne thermal infrared hyperspectral remote sensing.

  17. Transmissive metallic contact for amorphous silicon solar cells

    DOEpatents

    Madan, A.

    1984-11-29

    A transmissive metallic contact for amorphous silicon semiconductors includes a thin layer of metal, such as aluminum or other low work function metal, coated on the amorphous silicon with an antireflective layer coated on the metal. A transparent substrate, such as glass, is positioned on the light reflective layer. The metallic layer is preferably thin enough to transmit at least 50% of light incident thereon, yet thick enough to conduct electricity. The antireflection layer is preferably a transparent material that has a refractive index in the range of 1.8 to 2.2 and is approximately 550A to 600A thick.

  18. Two phenylalanines in the C-terminus of Epstein-Barr virus Rta protein reciprocally modulate its DNA binding and transactivation function

    SciTech Connect

    Chen, L.-W.; Raghavan, Vineetha; Chang, Pey-Jium; Shedd, Duane; Heston, Lee; Delecluse, Henri-Jacques; Miller, George

    2009-04-10

    The Rta (R transactivator) protein plays an essential role in the Epstein-Barr viral (EBV) lytic cascade. Rta activates viral gene expression by several mechanisms including direct and indirect binding to target viral promoters, synergy with EBV ZEBRA protein, and stimulation of cellular signaling pathways. We previously found that Rta proteins with C-terminal truncations of 30 aa were markedly enhanced in their capacity to bind DNA (Chen, L.W., Chang, P.J., Delecluse, H.J., and Miller, G., (2005). Marked variation in response of consensus binding elements for the Rta protein of Epstein-Barr virus. J. Virol. 79(15), 9635-9650.). Here we show that two phenylalanines (F600 and F605) in the C-terminus of Rta play a crucial role in mediating this DNA binding inhibitory function. Amino acids 555 to 605 of Rta constitute a functional DNA binding inhibitory sequence (DBIS) that markedly decreased DNA binding when transferred to a minimal DNA binding domain of Rta (aa 1-350). Alanine substitution mutants, F600A/F605A, abolished activity of the DBIS. F600 and F605 are located in the transcriptional activation domain of Rta. Alanine substitutions, F600A/F605A, decreased transcriptional activation by Rta protein, whereas aromatic substitutions, such as F600Y/F605Y or F600W/F605W, partially restored transcriptional activation. Full-length Rta protein with F600A/F605A mutations were enhanced in DNA binding compared to wild-type, whereas Rta proteins with F600Y/F605Y or F600W/F605W substitutions were, like wild-type Rta, relatively poor DNA binders. GAL4 (1-147)/Rta (416-605) fusion proteins with F600A/F605A mutations were diminished in transcriptional activation, relative to GAL4/Rta chimeras without such mutations. The results suggest that, in the context of a larger DBIS, F600 and F605 play a role in the reciprocal regulation of DNA binding and transcriptional activation by Rta. Regulation of DNA binding by Rta is likely to be important in controlling its different modes of

  19. Measurements of material properties for solar cells. [aluminum film and KAPTON

    NASA Technical Reports Server (NTRS)

    Castle, J. G., Jr.

    1978-01-01

    Measurements on two candidate materials for space flight are reported. The observed optical transmittance of aluminum films vapor deposited on fused quartz showed anomalously high transmittance thru 400 A and 600 A and showed an effective skin depth of 110 A in the latter part of the 1000 A thickness. KAPTON films are shown by their optical transmission spectra to have an energy gap for electron excitation of approximately 2.5 eV, which value depends on the thickness as manufactured. The resistance of KAPTON film to ionizing radiation is described by their optical spectra and their electron spin resonance spectra.

  20. JPRS Report, Science & Technology, USSR: Life Sciences.

    DTIC Science & Technology

    1987-07-28

    lysis was used in the screening bacterial colonies containing recombinant plasmids [u]. The transformation of E . coli bacteria C600(A) and HB101 with... transformants per [ig of DNA pBR322. The transformation of E . coli strains M5219, K-12AHlAtrp and N4030 was done with Humphries’ method, modified in that the...of T4 phage ligase DNA. After using the transformation of E . coli C600U) 0.0.1 ug of ligated mix, 5000 clones were obtained. The clones containing

  1. Electrically pumped 1.3 microm room-temperature InAs/GaAs quantum dot lasers on Si substrates by metal-mediated wafer bonding and layer transfer.

    PubMed

    Tanabe, Katsuaki; Guimard, Denis; Bordel, Damien; Iwamoto, Satoshi; Arakawa, Yasuhiko

    2010-05-10

    An electrically pumped InAs/GaAs quantum dot laser on a Si substrate has been demonstrated. The double-hetero laser structure was grown on a GaAs substrate by metal-organic chemical vapor deposition and layer-transferred onto a Si substrate by GaAs/Si wafer bonding mediated by a 380-nm-thick Au-Ge-Ni alloy layer. This broad-area Fabry-Perot laser exhibits InAs quantum dot ground state lasing at 1.31 microm at room temperature with a threshold current density of 600 A/cm(2).

  2. 7.5K 1bf Thrust Engine Preliminary Design for Orbit Transfer Vehicle. Task D.5

    DTIC Science & Technology

    1994-01-01

    Mw 0 a:G CC L. W W - 1D 0 Li0W ao N «rF o()u C5U a: NJ LL L : - a- 0 D CL t (.) a"-.Y cc w c C 0--C/) coZ0 a- 3 wr-: z ~>-> >WuOZU) C/) -L -c *D W LL... EZW < O a c 0&#600 a 6Ug 0 x w Qa j a -L W < w C) t -1 301 the engine and the components that could be changed out in space by astronauts in space suits

  3. Experimental and Theoretical Investigation of Microwave and Millimeter Wave Radiation from Hollow, Rotating, Electron Beams.

    DTIC Science & Technology

    1981-11-01

    detection bands (X, Ku, K (a) produced by a rotating electron beam in a cylindrical drif t tube. 9- 600 (a a)400- ~200. 28 32 36 f (GHz) 600 (b) ~400...are plotted in an radii Rj,Ro, as shown in Fig. 2. o- k , diagram. At the interaction points indicated ( k -f ,a-) The stability of the system is examined...by linearizingw-kqs diaram Atd t5h. i ercto porbit indicaton ( k -naw -) and ( k ,’ ,w), we have "resopant interaction". If these are Eqs. (4) and (5

  4. Comparison of Voltage Gated K(+) Currents in Arterial Myocytes with Heterologously Expressed K v Subunits.

    PubMed

    Cox, Robert H; Fromme, Samantha

    2016-12-01

    We have shown that three components contribute to functional voltage gated K(+) (K v) currents in rat small mesenteric artery myocytes: (1) Kv1.2 plus Kv1.5 with Kvβ1.2 subunits, (2) Kv2.1 probably associated with Kv9.3 subunits, and (3) Kv7.4 subunits. To confirm and address subunit stoichiometry of the first two, we have compared the biophysical properties of K v currents in small mesenteric artery myocytes with those of Kv subunits heterologously expressed in HEK293 cells using whole cell voltage clamp methods. Selective inhibitors of Kv1 (correolide, COR) and Kv2 (stromatoxin, ScTx) channels were used to separate these K v current components. Conductance-voltage and steady state inactivation data along with time constants of activation, inactivation, and deactivation of native K v components were generally well represented by those of Kv1.2-1.5-β1.2 and Kv2.1-9.3 channels. The slope of the steady state inactivation-voltage curve (availability slope) proved to be the most sensitive measure of accessory subunit presence. The availability slope curves exhibited a single peak for both native K v components. Availability slope curves for Kv1.2-1.5-β1.2 and Kv2.1-9.3 channels expressed in human embryonic kidney cells also exhibited a single peak that shifted to more depolarized voltages with increasing accessory to α subunit transfection ratio. Availability slope curves for SxTc-insensitive currents were similar to those of Kv1.2-1.5 expressed with Kvβ1.2 at a 1:5 molar ratio while curves for COR-insensitive currents closely resembled those of Kv2.1 expressed with Kv9.3 at a 1:1 molar ratio. These results support the suggested Kv subunit combinations in small mesenteric artery, and further suggest that Kv1 α and Kvβ1.2 but not Kv2.1 and Kv9.3 subunits are present in a saturated (4:4) stoichiometry.

  5. A Novel Pan-Negative-Gating Modulator of KCa2/3 Channels, Fluoro-Di-Benzoate, RA-2, Inhibits Endothelium-Derived Hyperpolarization–Type Relaxation in Coronary Artery and Produces Bradycardia In Vivo

    PubMed Central

    Oliván-Viguera, Aida; Valero, Marta Sofía; Coleman, Nicole; Brown, Brandon M.; Laría, Celia; Divina Murillo, María; Gálvez, José A.; Díaz-de-Villegas, María D.; Wulff, Heike; Badorrey, Ramón

    2015-01-01

    Small/intermediate conductance KCa channels (KCa2/3) are Ca2+/calmodulin regulated K+ channels that produce membrane hyperpolarization and shape neurologic, epithelial, cardiovascular, and immunologic functions. Moreover, they emerged as therapeutic targets to treat cardiovascular disease, chronic inflammation, and some cancers. Here, we aimed to generate a new pharmacophore for negative-gating modulation of KCa2/3 channels. We synthesized a series of mono- and dibenzoates and identified three dibenzoates [1,3-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate) (RA-2), 1,2-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate), and 1,4-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate)] with inhibitory efficacy as determined by patch clamp. Among them, RA-2 was the most drug-like and inhibited human KCa3.1 with an IC50 of 17 nM and all three human KCa2 subtypes with similar potencies. RA-2 at 100 nM right-shifted the KCa3.1 concentration-response curve for Ca2+ activation. The positive-gating modulator naphtho[1,2-d]thiazol-2-ylamine (SKA-31) reversed channel inhibition at nanomolar RA-2 concentrations. RA-2 had no considerable blocking effects on distantly related large-conductance KCa1.1, Kv1.2/1.3, Kv7.4, hERG, or inwardly rectifying K+ channels. In isometric myography on porcine coronary arteries, RA-2 inhibited bradykinin-induced endothelium-derived hyperpolarization (EDH)–type relaxation in U46619-precontracted rings. Blood pressure telemetry in mice showed that intraperitoneal application of RA-2 (≤100 mg/kg) did not increase blood pressure or cause gross behavioral deficits. However, RA-2 decreased heart rate by ≈145 beats per minute, which was not seen in KCa3.1−/− mice. In conclusion, we identified the KCa2/3–negative-gating modulator, RA-2, as a new pharmacophore with nanomolar potency. RA-2 may be of use to generate structurally new types of negative-gating modulators that could help to define the physiologic and pathomechanistic

  6. A novel pan-negative-gating modulator of KCa2/3 channels, fluoro-di-benzoate, RA-2, inhibits endothelium-derived hyperpolarization-type relaxation in coronary artery and produces bradycardia in vivo.

    PubMed

    Oliván-Viguera, Aida; Valero, Marta Sofía; Coleman, Nicole; Brown, Brandon M; Laría, Celia; Murillo, María Divina; Gálvez, José A; Díaz-de-Villegas, María D; Wulff, Heike; Badorrey, Ramón; Köhler, Ralf

    2015-02-01

    Small/intermediate conductance KCa channels (KCa2/3) are Ca(2+)/calmodulin regulated K(+) channels that produce membrane hyperpolarization and shape neurologic, epithelial, cardiovascular, and immunologic functions. Moreover, they emerged as therapeutic targets to treat cardiovascular disease, chronic inflammation, and some cancers. Here, we aimed to generate a new pharmacophore for negative-gating modulation of KCa2/3 channels. We synthesized a series of mono- and dibenzoates and identified three dibenzoates [1,3-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate) (RA-2), 1,2-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate), and 1,4-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate)] with inhibitory efficacy as determined by patch clamp. Among them, RA-2 was the most drug-like and inhibited human KCa3.1 with an IC50 of 17 nM and all three human KCa2 subtypes with similar potencies. RA-2 at 100 nM right-shifted the KCa3.1 concentration-response curve for Ca(2+) activation. The positive-gating modulator naphtho[1,2-d]thiazol-2-ylamine (SKA-31) reversed channel inhibition at nanomolar RA-2 concentrations. RA-2 had no considerable blocking effects on distantly related large-conductance KCa1.1, Kv1.2/1.3, Kv7.4, hERG, or inwardly rectifying K(+) channels. In isometric myography on porcine coronary arteries, RA-2 inhibited bradykinin-induced endothelium-derived hyperpolarization (EDH)-type relaxation in U46619-precontracted rings. Blood pressure telemetry in mice showed that intraperitoneal application of RA-2 (≤100 mg/kg) did not increase blood pressure or cause gross behavioral deficits. However, RA-2 decreased heart rate by ≈145 beats per minute, which was not seen in KCa3.1(-/-) mice. In conclusion, we identified the KCa2/3-negative-gating modulator, RA-2, as a new pharmacophore with nanomolar potency. RA-2 may be of use to generate structurally new types of negative-gating modulators that could help to define the physiologic and pathomechanistic

  7. New Positive Ca2+-Activated K+ Channel Gating Modulators with Selectivity for KCa3.1

    PubMed Central

    Coleman, Nichole; Brown, Brandon M.; Oliván-Viguera, Aida; Singh, Vikrant; Olmstead, Marilyn M.; Valero, Marta Sofia; Köhler, Ralf

    2014-01-01

    Small-conductance (KCa2) and intermediate-conductance (KCa3.1) calcium-activated K+ channels are voltage-independent and share a common calcium/calmodulin-mediated gating mechanism. Existing positive gating modulators like EBIO, NS309, or SKA-31 activate both KCa2 and KCa3.1 channels with similar potency or, as in the case of CyPPA and NS13001, selectively activate KCa2.2 and KCa2.3 channels. We performed a structure-activity relationship (SAR) study with the aim of optimizing the benzothiazole pharmacophore of SKA-31 toward KCa3.1 selectivity. We identified SKA-111 (5-methylnaphtho[1,2-d]thiazol-2-amine), which displays 123-fold selectivity for KCa3.1 (EC50 111 ± 27 nM) over KCa2.3 (EC50 13.7 ± 6.9 μM), and SKA-121 (5-methylnaphtho[2,1-d]oxazol-2-amine), which displays 41-fold selectivity for KCa3.1 (EC50 109 nM ± 14 nM) over KCa2.3 (EC50 4.4 ± 1.6 μM). Both compounds are 200- to 400-fold selective over representative KV (KV1.3, KV2.1, KV3.1, and KV11.1), NaV (NaV1.2, NaV1.4, NaV1.5, and NaV1.7), as well as CaV1.2 channels. SKA-121 is a typical positive-gating modulator and shifts the calcium-concentration response curve of KCa3.1 to the left. In blood pressure telemetry experiments, SKA-121 (100 mg/kg i.p.) significantly lowered mean arterial blood pressure in normotensive and hypertensive wild-type but not in KCa3.1−/− mice. SKA-111, which was found in pharmacokinetic experiments to have a much longer half-life and to be much more brain penetrant than SKA-121, not only lowered blood pressure but also drastically reduced heart rate, presumably through cardiac and neuronal KCa2 activation when dosed at 100 mg/kg. In conclusion, with SKA-121, we generated a KCa3.1-specific positive gating modulator suitable for further exploring the therapeutical potential of KCa3.1 activation. PMID:24958817

  8. Mitochondrial Ultrastructure and Glucose Signaling Pathways Attributed to the Kv1.3 Ion Channel

    PubMed Central

    Kovach, Christopher P.; Al Koborssy, Dolly; Huang, Zhenbo; Chelette, Brandon M.; Fadool, James M.; Fadool, Debra A.

    2016-01-01

    Gene-targeted deletion of the potassium channel Kv1.3 (Kv1.3−∕−) results in “Super-smeller” mice with a sensory phenotype that includes an increased olfactory ability linked to changes in olfactory circuitry, increased abundance of olfactory cilia, and increased expression of odorant receptors and the G-protein, Golf. Kv1.3−∕− mice also have a metabolic phenotype including lower body weight and decreased adiposity, increased total energy expenditure (TEE), increased locomotor activity, and resistance to both diet- and genetic-induced obesity. We explored two cellular aspects to elucidate the mechanism by which loss of Kv1.3 channel in the olfactory bulb (OB) may enhance glucose utilization and metabolic rate. First, using in situ hybridization we find that Kv1.3 and the insulin-dependent glucose transporter type 4 (GLUT4) are co-localized to the mitral cell layer of the OB. Disruption of Kv1.3 conduction via construction of a pore mutation (W386F Kv1.3) was sufficient to independently translocate GLUT4 to the plasma membrane in HEK 293 cells. Because olfactory sensory perception and the maintenance of action potential (AP) firing frequency by mitral cells of the OB is highly energy demanding and Kv1.3 is also expressed in mitochondria, we next explored the structure of this organelle in mitral cells. We challenged wildtype (WT) and Kv1.3−∕− male mice with a moderately high-fat diet (MHF, 31.8 % kcal fat) for 4 months and then examined OB ultrastructure using transmission electron microscopy. In WT mice, mitochondria were significantly enlarged following diet-induced obesity (DIO) and there were fewer mitochondria, likely due to mitophagy. Interestingly, mitochondria were significantly smaller in Kv1.3−∕− mice compared with that of WT mice. Similar to their metabolic resistance to DIO, the Kv1.3−∕− mice had unchanged mitochondria in terms of cross sectional area and abundance following a challenge with modified diet. We are very

  9. Asymmetrical distribution of ion channels in canine and human left-ventricular wall: epicardium versus midmyocardium.

    PubMed

    Szabó, Gergely; Szentandrássy, Norbert; Bíró, Tamás; Tóth, Balázs I; Czifra, Gabriella; Magyar, János; Bányász, Tamás; Varró, András; Kovács, László; Nánási, Péter P

    2005-08-01

    The aim of the present study was to compare the distribution of ion currents and the major underlying ion channel proteins in canine and human subepicardial (EPI) and midmyocardial (MID) left-ventricular muscle. Ion currents and action potentials were recorded from canine cardiomyocytes derived from the very superficial EPI and central MID regions of the left ventricle. Amplitude, duration and the maximum velocity of depolarization of the action potential were significantly greater in MID than EPI myocytes, whereas phase-1 repolarization was more pronounced in the EPI cells. Amplitudes of the transient outwards K+ current (29.5+/-1.5 vs. 19.0+/-2.3 pA/pF at +50 mV) and the slow component of the delayed rectifier K+ current (10.3+/-2.3 vs. 6.5+/-1.0 pA/pF at +50 mV) were significantly larger in EPI than in MID myocytes under whole-cell voltage-clamp conditions. The densities of the inwards rectifier K+ current, rapid delayed rectifier K+ current and L-type Ca2+ current were similar in both cell types. Expression of channel proteins in both canine and human ventricular myocardium was determined by Western blotting. In the canine heart, the expression of Kv4.3, Kv1.4, KChIP2 and KvLQT1 was significantly higher, and that of Nav1.5 and MinK much lower, in EPI than in MID. No significant EPI-MID differences were observed in the expression of the other channel proteins studied (Kir2.1, alpha1C, HERG and MiRP1). Similar results were obtained in human hearts, although the HERG was more abundant in the EPI than in the MID layer. In the canine heart, the EPI-MID differences in ion current densities were proportional to differences in channel protein expression. Except for the density of HERG, the pattern of EPI-MID distribution of ion-channel proteins was identical in canine and human ventricles.

  10. Thermodynamic analysis of hydrocarbon refrigerants-based ethylene BOG re-liquefaction system

    NASA Astrophysics Data System (ADS)

    Beladjine, Boumedienne M.; Ouadha, Ahmed; Addad, Yacine

    2016-09-01

    The present study aims to make a thermodynamic analysis of an ethylene cascade re-liquefaction system that consists of the following two subsystems: a liquefaction cycle using ethylene as the working fluid and a refrigeration cycle operating with a hydrocarbon refrigerant. The hydrocarbon refrigerants considered are propane (R290), butane (R600), isobutane (R600a), and propylene (R1270). A computer program written in FORTRAN is developed to compute parameters for characteristic points of the cycles and the system's performance, which is determined and analyzed using numerical solutions for the refrigerant condensation temperature, temperature in tank, and temperature difference in the cascade condenser. Results show that R600a gives the best performance, followed by (in order) R600, R290, and R1270. Furthermore, it is found that an increase in tank temperature improves system performance but that an increase in refrigerant condensation temperature causes deterioration. In addition, it is found that running the system at a low temperature difference in the cascade condenser is advantageous.

  11. Morning/Evening differences in somatosensory inputs for postural control.

    PubMed

    Bougard, Clément; Davenne, Damien

    2014-01-01

    The underlying processes responsible for the differences between morning and afternoon measurements of postural control have not yet been clearly identified. This study was conducted to specify the role played by vestibular, visual, and somatosensory inputs in postural balance and their link with the diurnal fluctuations of body temperature and vigilance level. Nineteen healthy male subjects (mean age: 20.5 ± 1.3 years) participated in test sessions at 6:00 a.m. and 6:00 p.m. after a normal night's sleep. Temperature was measured before the subjects completed a sign cancellation test and a postural control evaluation with eyes both open and closed. Our results confirmed that postural control improved throughout the day according to the circadian rhythm of body temperature and sleepiness/vigilance. The path length as a function of surface ratio increased between 6:00 a.m. and 6:00 p.m. This is due to a decrease in the centre-of-pressure surface area, which is associated with an increase in path length. Romberg's index did not change throughout the day; however, the spectral analysis (fast Fourier transform) of the centre-of-pressure excursions (in anteroposterior and mediolateral directions) indicated that diurnal fluctuations in postural control may occur via changes in the different processes responsible for readjustment via muscle contractions.

  12. Experimental study of a novel photovoltaic solar-assisted heat pump/loop heat-pipe (PV-SAHP/LHP) system

    NASA Astrophysics Data System (ADS)

    Zhang, Tao; Pei, Gang; Zhu, Qunzhi; Ji, Jie

    2017-01-01

    A prototype of a photovoltaic solar-assisted heat-pump/loop heat-pipe system (PV-SAHP/LHP) was constructed in this paper. The system was a combination of photovoltaic solar-assisted heat pump system (PV-SAHP) and loop heat pipe photovoltaic/thermal (LHP-PV/T) system. The combined system can carry out with two modes but using the same working fluid, and the two modes can switch operation freely. R600a was employed as the working fluid, and system performance under different working mode was presented in this paper. The results show that the day average photothermal efficiency & photovoltaic efficiency can reach to 43.6% & 11.3% under LHP-PV/T working mode compared with that of 57.5% & 12.1% under PV-SAHP working mode: Besides that, a day average COP of 3.66 was obtained under PV-SAHP working mode.

  13. Passivation oxide controlled selective carbon nanotube growth on metal substrates.

    PubMed

    Bult, J B; Sawyer, W G; Ajayan, P M; Schadler, L S

    2009-02-25

    Vertically aligned arrays of multi-wall carbon nanotubes (MWNT) are grown on Inconel 600, a nickel-based super-alloy. Using x-ray photoelectron spectroscopy (XPS) and chemical vapor deposition (CVD) growth of the MWNTs it is shown that a stable oxidation barrier is required for the stabilization of iron on the substrate and subsequent nanotube growth. This evidence for passivation oxide supported growth of MWNTs was then used to grow MWNTs on patterned oxidized substrates in a selective growth furnace. The unique advantage of this patterned growth on Inconel 600 is found to be the chromia passivation layer's electrical conductivity (measured value of 1.08 micro Omega m), creating the opportunity for low resistivity electrodes made from nanotubes. Inconel substrates with 100 microm long aligned MWNTs are demonstrated to exhibit an average resistance value of 2 Omega.

  14. Suspension Plasma-Sprayed ZnFe2O4 Nanostructured Coatings for ppm-Level Acetone Detection

    NASA Astrophysics Data System (ADS)

    You, Jiajun; Chen, Xia; Zheng, Bingbing; Geng, Xin; Zhang, Chao

    2017-02-01

    Zinc ferrite (ZnFe2O4) sensitive coatings have been deposited by suspension plasma spraying. The phase constitution of the coatings was characterized by x-ray diffraction while the top surface and cross-sectional morphology of the coatings were inspected by scanning electron microscopy. The response to acetone was tested with the concentration in the range of 25-500 ppm at the working temperature from 175 to 275 °C. The sensors that were deposited at an arc current of 400 A showed better performance than those at 600 A owing to small grain size and high porosity. The sensor response increased with acetone concentration. The optimized sensors showed excellent response/recovery time and selectivity to acetone at 200 °C.

  15. Low-temperature photoluminescence studies of chemical-vapor-deposition-grown 3C-SiC on Si

    NASA Technical Reports Server (NTRS)

    Choyke, W. J.; Feng, Z. C.; Powell, J. A.

    1988-01-01

    Low-temperature photoluminescence studies of 26 cubic SiC films, ranging in thickness from 600 A to 25 microns, grown by CVD on (100)Si are presented. It is suggested that the G band near 1.90-1.92 eV and its phonon side bands G1 and G2 are related to dislocations and extended defects. Formulas for the band-gap shift due to an axial stress have been obtained and applied to the CVD 3C-SiC/Si system. The results indicate that a 1-3-micron transition layer greatly reduces the interface misfit strain, and that biaxial stress in the SiC/Si system depresses the intensity of the no-phonon line.

  16. Study to determine the existence of an azeotropic R-22 `drop-in` substitute

    SciTech Connect

    Kim, M.S.; Morrison, G.; Mulroy, W.J.; Didion, D.A.

    1996-03-01

    The reduction in chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) production and the scheduled phase-out of these ozone depleting refrigerants requires the development and determination of environmentally safe refrigerants for use in heat pumps, water chillers, air conditioners, and refrigerators. Azeotropic mixtures are attractive as alternative refrigerants because they behave very nearly as pure materials. A simple correlative scheme that allows one to judge whether or not an azeotrope is likely in a binary refrigerant mixture is discussed. This paper presents laboratory and computer simulation model evaluation of two of the azeotropic refrigerant mixtures which are identified, HFC-134a (1,1,1,2-tetrafluoroethane) with R-C290 (Propane) and HFC-134a with R-600a (Isobutane), in a generic heat pump apparatus. A third azeotropes mixture, HFC-134a with R-C290 (Cyclopropane) is examined by computer simulation only.

  17. A compact and continuously driven supersonic plasma and neutral source.

    PubMed

    Asai, T; Itagaki, H; Numasawa, H; Terashima, Y; Hirano, Y; Hirose, A

    2010-10-01

    A compact and repetitively driven plasma source has been developed by utilizing a magnetized coaxial plasma gun (MCPG) for diagnostics requiring deep penetration of a large amount of neutral flux. The system consists of a MCPG 95mm in length with a DN16 ConFlat connection port and an insulated gate bipolar transistor (IGBT) inverter power unit. The power supply consists of an array of eight IGBT units and is able to switch the discharge on and off at up to 10 kV and 600 A with a maximum repetitive frequency of 10 kHz. Multiple short duration discharge pulses maximize acceleration efficiency of the plasmoid. In the case of a 10 kHz operating frequency, helium-plasmoids in the velocity range of 20 km/s can be achieved.

  18. A compact and continuously driven supersonic plasma and neutral source

    SciTech Connect

    Asai, T.; Itagaki, H.; Numasawa, H.; Terashima, Y.; Hirano, Y.; Hirose, A.

    2010-10-15

    A compact and repetitively driven plasma source has been developed by utilizing a magnetized coaxial plasma gun (MCPG) for diagnostics requiring deep penetration of a large amount of neutral flux. The system consists of a MCPG 95mm in length with a DN16 ConFlat connection port and an insulated gate bipolar transistor (IGBT) inverter power unit. The power supply consists of an array of eight IGBT units and is able to switch the discharge on and off at up to 10 kV and 600 A with a maximum repetitive frequency of 10 kHz. Multiple short duration discharge pulses maximize acceleration efficiency of the plasmoid. In the case of a 10 kHz operating frequency, helium-plasmoids in the velocity range of 20 km/s can be achieved.

  19. Experimental study on heat transfer performance of pulsating heat pipe with refrigerants

    NASA Astrophysics Data System (ADS)

    Wang, Xingyu; Jia, Li

    2016-10-01

    The effects of different refrigerants on heat transfer performance of pulsating heat pipe (PHP) are investigated experimentally. The working temperature of pulsating heat pipe is kept in the range of 20°C-50°C. The startup time of the pulsating heat pipe with refrigerants can be shorter than 4 min, when heating power is in the range of 10W?100W. The startup time decreases with heating power. Thermal resistances of PHP with filling ratio 20.55% were obviously larger than those with other filling ratios. Thermal resistance of the PHP with R134a is much smaller than that with R404A and R600a. It indicates that the heat transfer ability of R134a is better. In addition, a correlation to predict thermal resistance of PHP with refrigerants was suggested.

  20. The population of hot subdwarf stars studied with Gaia. I. The catalog of known hot subdwarf stars

    NASA Astrophysics Data System (ADS)

    Geier, S.; Østensen, R. H.; Nemeth, P.; Gentile Fusillo, N. P.; Gänsicke, B. T.; Telting, J. H.; Green, E. M.; Schaffenroth, J.

    2017-03-01

    In preparation for the upcoming all-sky data releases of the Gaia mission we compiled a catalog of known hot subdwarf stars and candidates drawn from the literature and yet unpublished databases. The catalog contains 5613 unique sources and provides multi-band photometry from the ultraviolet to the far infrared, ground based proper motions, classifications based on spectroscopy and colors, published atmospheric parameters, radial velocities and light curve variability information. Using several different techniques we removed outliers and misclassified objects. By matching this catalog with astrometric and photometric data from the Gaia mission, we will develop selection criteria to construct a homogeneous, magnitude-limited all-sky catalog of hot subdwarf stars based on Gaia data. The catalog is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A50

  1. Mechanisms of stress corrosion cracking and intergranular attack in Alloy 600 in high temperature caustic and pure water

    SciTech Connect

    Bandy, R.; van Rooyen, D.

    1984-01-01

    In recent years, several studies have been conducted on the intergranular stress corrosion cracking (SCC) and intergranular attack (IGA) of Alloy 600. A combination of SCC and IGA has been observed in Alloy 600 tubing on the hot leg of some operating steam generators in pressurized water reactor (PWR) nuclear power plants, and sodium hydroxide along with several other chemical species have been implicated in the tube degradations. SCC has been observed above and within the tube sheet, whereas IGA is generally localized within the tube sheet. Alloy 600 is also susceptible to SCC in pure and primary water. Various factors that influence SCC and IGA include metallurgical conditions of the alloy, concentrations of alkaline species, impurity content of the environment, temperature and stress. The mechanisms of these intergranular failures, however, are not well understood. Some of the possible mechanisms of the SCC and IGA in high temperature water and caustic are described in this paper.

  2. Spectroscopic Analysis of Perfluoropolyether Lubricant Degradation During Boundary Lubrication

    NASA Technical Reports Server (NTRS)

    Herrera-Fierro, Pilar; Shogrin, Bradley A.; Jones, William R., Jr.

    1996-01-01

    The degradation of a branched perfluoropolyether (PFPE) under boundary lubrication conditions was studied using mu-FTIR and mu-Raman spectroscopies. Stainless steel (440C) discs coated with thin (600A), uniform films of the PFPE were tested in a ball-on-disc apparatus until various levels of friction coefficient were attained. Discs were then examined using the above techniques. When the friction coefficient surpassed the value obtained with an un-lubricated control, the lubricant film had either been physically displaced or partially transformed in to a 'friction polymer'. Infrared analysis of this 'friction polymer' indicated the presence of a polymeric fluorinated acid species (R(sub f)COOH). Raman spectroscopy indicated the presence of amorphous carbon in the wear track and in the friction polymer. Some reaction mechanisms are suggested to explain the results.

  3. In vitro retinal imaging with full field swept source optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Fergusson, James; Považay, Boris; Hofer, Bernd; Drexler, Wolfgang

    2010-02-01

    Weakly scattering tree shrew retina has been imaged in vitro with full field swept source optical coherence tomography, visualising multiple intraretinal layers. The system utilises a 50nm bandwidth Superlum SLD, to acheive ~8μm of axial resolution and 4μm of transversal resolution. Volumetric images of retinal tissue with dimensions of 1248x936x678μm (horizontal by vertical by axial) were recorded in two second (equivalent of 153,600 A-scans per second) with a measured signal to noise ratio of 75dB. From the 5mW of SLD optical power available, 720μW illuminates the sample, giving a power per pixel of 4.6nW, ten times less power per pixel then standard FDOCT systems. After upgrading the camera and redesigning the optical beam path, 82dB of SNR was realised.

  4. Azimuthal anisotropies as stringent test for nuclear transport models

    NASA Astrophysics Data System (ADS)

    Crochet, P.; Rami, F.; Donà, R.; Coffin, J. P.; Fintz, P.; Guillaume, G.; Jundt, F.; Kuhn, C.; Roy, C.; de Schauenburg, B.; Tizniti, L.; Wagner, P.; Alard, J. P.; Andronic, A.; Basrak, Z.; Bastid, N.; Belyaev, I.; Bendarag, A.; Berek, G.; Best, D.; Biegansky, J.; Buta, A.; Čaplar, R.; Cindro, N.; Dupieux, P.; Dželalija, M.; Fan, Z. G.; Fodor, Z.; Fraysse, L.; Freifelder, R. P.; Gobbi, A.; Herrmann, N.; Hildenbrand, K. D.; Hong, B.; Jeong, S. C.; Kecskemeti, J.; Kirejczyk, M.; Koncz, P.; Korolija, M.; Kotte, R.; Lebedev, A.; Leifels, Y.; Manko, V.; Moisa, D.; Mösner, J.; Neubert, W.; Pelte, D.; Petrovici, M.; Pinkenburg, C.; Reisdorf, W.; Ritman, J. L.; Sadchikov, A. G.; Schüll, D.; Seres, Z.; Sikora, B.; Simion, V.; Siwek-Wilczyńska, K.; Sodan, U.; Teh, K. M.; Trzaska, M.; Wang, G. S.; Wessels, J. P.; Wienold, T.; Wisniewski, K.; Wohlfarth, D.; Zhilin, A.; Hartnack, C.; FOPI Collaboration

    1997-02-01

    Azimuthal distributions of charged particles and intermediate mass fragments emitted in Au+Au collisions at 600 A MeV have been measured using the FOPI facility at GSI-Darmstadt. Data show a strong increase of the in-plane azimuthal anisotropy ratio with the charge of the detected fragment. Intermediate mass fragments are found to exhibit a strong momentum-space alignment with respect of the reaction plane. The experimental results are presented as a function of the polar centre-of-mass angle and over a broad range of impact parameters. They are compared to the predictions of the Isospin Quantum Molecular Dynamics model using three different parametrisations of the equation of state. We show that such highly accurate data provide stringent test for microscopic transport models and can potentially constrain separately the stiffness of the nuclear equation of state and the momentum dependence of the nuclear interaction.

  5. 600 kV modulator design for the SLAC Next Linear Collider Test Accelerator

    SciTech Connect

    Harris, K.; de Lamare, J.; Nesterov, V.; Cassel, R.

    1992-07-01

    Preliminary design for the SLAC Next Linear Collider Test Accelerator (NLCTA) requires a pulse power source to produce a 600 kV, 600 A, 1.4 {mu}s, 0.1% flat top pulse with rise and fall times of approximately 100 ns to power an X-Band klystron with a microperveance of 1.25 at {approx} 100 MW peak RF power. The design goals for the modulator, including those previously listed, are peak modulator pulse power of 340 MW operating at 120 Hz. A three-stage darlington pulse-forming network, which produces a >100 kV, 1.4 {mu}s pulse, is coupled to the klystron load through a 6:1 pulse transformer. Careful consideration of the transformer leakage inductance, klystron capacitance, system layout, and component choice is necessary to produce the very fast rise and fall times at 600 kV operating continuously at 120 Hz.

  6. Hot-electron luminescence in aged electrodeposited CdSe liquid-junction solar cell

    SciTech Connect

    Silberstein, R.P.; Tomkiewicz, M.

    1983-01-01

    We have utilized Raman spectroscopy and scanning Auger electron spectroscopy (AES) to probe the surface of polycrystalline, electrodeposited CdSe photoelectrodes which have been aged in a polysulfide electrolyte under illumination and in darkness. We have observed characteristic ''hot-electron'' luminescence at multiples of ..omega../sub LO/ (CdS) = 305 cm/sup -1/ in the light-aged electrode, indicating that a surface layer of CdS has been formed. AES profiling shows that extensive substitution of S for Se has occurred, in the light-aged electrode alone, to a depth of approx.600 A. Measurements at 300 K suggest that Raman scattering can be a useful, in situ, contactless, nondestructive probe of CdS formation.

  7. Analysis of Environmentally Friendly Refrigerant Options for Window Air Conditioners

    SciTech Connect

    Bansal, Pradeep; Shen, Bo

    2015-03-12

    This paper presents a technical assessment of environmentally friendly refrigerants as alternatives to R410A for window air conditioners. The alternative refrigerants that are studied for its replacement include R32, a mixture of R32/R125 with 90%/10% molar concentration, R600a, R290, R1234yf, R1234ze and R134a. Baseline experiments were performed on a window unit charged with R410A. The heat pump design model (HPDM) was modified and calibrated with the baseline data and was used to evaluate the comparative performance of the WAC with alternative refrigerants. The paper discusses the advantages and disadvantages of each refrigerants and their suitability for window air conditioners. Among all the refrigerants studied, R32 offers the best efficiency and the lowest Global Warming Potential (GWP), and hence its use will result in the overall environmental friendliness.

  8. Analysis of Environmentally Friendly Refrigerant Options for Window Air Conditioners

    DOE PAGES

    Bansal, Pradeep; Shen, Bo

    2015-03-12

    This paper presents a technical assessment of environmentally friendly refrigerants as alternatives to R410A for window air conditioners. The alternative refrigerants that are studied for its replacement include R32, a mixture of R32/R125 with 90%/10% molar concentration, R600a, R290, R1234yf, R1234ze and R134a. Baseline experiments were performed on a window unit charged with R410A. The heat pump design model (HPDM) was modified and calibrated with the baseline data and was used to evaluate the comparative performance of the WAC with alternative refrigerants. The paper discusses the advantages and disadvantages of each refrigerants and their suitability for window air conditioners. Amongmore » all the refrigerants studied, R32 offers the best efficiency and the lowest Global Warming Potential (GWP), and hence its use will result in the overall environmental friendliness.« less

  9. Tough, processable semi-interpenetrating polymer networks from monomer reactants

    NASA Technical Reports Server (NTRS)

    Pater, Ruth H. (Inventor)

    1994-01-01

    A high temperature semi-interpenetrating polymer network (semi-IPN) was developed which had significantly improved processability, damage tolerance, and mechanical performance, when compared to the commercial Thermid materials. This simultaneous semi-IPN was prepared by mixing the monomer precursors of Thermid AL-600 (a thermoset) and NR-150B2 (a thermoplastic) and allowing the monomers to react randomly upon heating. This reaction occurs at a rate which decreases the flow and broadens the processing window. Upon heating at a higher temperature, there is an increase in flow. Because of the improved flow properties, broadened processing window and enhanced toughness, high strength polymer matrix composites, adhesives and molded articles can now be prepared from the acetylene end-capped polyimides which were previously inherently brittle and difficult to process.

  10. Crystallization of heavy metal fluoride glasses

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.; Bruce, Allan J.; Doremus, R. H.; Moynihan, C. T.

    1984-01-01

    The kinetics of crystallization of a number of fluorozirconate glasses were studied using isothermal and dynamic differential scanning calorimetry and X-ray diffraction. The addition of the fluorides LiF, NaF, AlF3, LaF3 to a base glass composition of ZrF4-BaF2 reduced the tendency to crystallize, probably by modifying the viscosity-temperature relation. ZrF4-BaF2-LaF3-AlF3-NaF glass was the most stable against devitrification and perhaps is the best composition for optical fibers with low scattering loss. Some glasses first crystallize out into metastable beta-BaZr2F10 and beta-BaZrF6 phases, which transform into the most stable alpha-phases when heated to higher temperatures. The size of the crystallites was estimated to be about 600 A from X-ray diffraction.

  11. Evidence of melatonin synthesis in the ram reproductive tract.

    PubMed

    Gonzalez-Arto, M; Hamilton, T R dos S; Gallego, M; Gaspar-Torrubia, E; Aguilar, D; Serrano-Blesa, E; Abecia, J A; Pérez-Pé, R; Muiño-Blanco, T; Cebrián-Pérez, J A; Casao, A

    2016-01-01

    Melatonin is a ubiquitous molecule found in a wide range of fluids, one of them being ram seminal plasma, in which it can reach higher concentrations than those found in blood, suggesting an extrapineal secretion by the reproductive tract. In order to identify the source of the melatonin found in ram seminal plasma, we first tried to determine whether the melatonin levels were maintained during the day. For this purpose, melatonin concentrations were measured in seminal plasma obtained from first ejaculates of six rams at 6:00 a.m. in total darkness, at 10:00 a.m. and at 14:00 p.m. The melatonin concentration was higher (p < 0.05) in ejaculates collected at 6:00 a.m. than at 10:00 and 14:00. There was no statistical difference between the latter. To further corroborate an extrapineal secretion of melatonin, the presence of the two key enzymes involved in melatonin synthesis, arylalkylamine-N-acetyltransferase (AANAT) and N-acetylserotonin-O-methyltransferase (ASMT) was analyzed by RT-PCR, q-PCR and Western-blot in ram testes, epididymis, and accessory glands. The RT-PCR showed the presence of the m-RNA codifying both AANAT and ASTM in all the tissues under study, but the q-PCR and Western-blot revealed that gene expression of these enzymes was significantly higher in the testis (p < 0.05). Immunohistochemistry confirmed the presence of AANAT and ASMT in the testis and revealed that they were found in the Leydig cells, spermatocytes, and spermatids. Also, measurable levels of melatonin were found in testicular tissue and the tail of the epididymis. In conclusion, our study indicates that the testes are one of the likely sources of the high levels of melatonin found in ram seminal plasma, at least during the day.

  12. Role of K+ and Ca2+ fluxes in the cerebroarterial vasoactive effects of sildenafil.

    PubMed

    Salom, Juan B; Castelló-Ruiz, María; Burguete, María C; Guzmán, Carla; Jover-Mengual, Teresa; Torregrosa, Germán; Jover, Ramiro; Lizasoain, Ignacio; Alborch, Enrique

    2008-02-26

    The aim of this study was to assess the role of K(+) and Ca(2+) fluxes in the cerebroarterial vasoactive effects of the phosphodiesterase-5 inhibitor sildenafil. We used isolated rabbit basilar arteries to assess the effects of extracellular K(+) raising on sildenafil-induced vasodilatation, and studied the pharmacological interaction of sildenafil with selective modulators of membrane K(+) and Ca(2+) channels. Expression of Kv1 subunits of K(+) channels was assessed at messenger and protein levels. Parallel experiments were carried out with zaprinast for comparison. Sildenafil (10 nM-0.1 mM) induced concentration-dependent relaxation of endothelin-1 (10 nM)-precontracted arteries, which was partially inhibited by depolarization with KCl (50 mM), 3 mM tetraethylammonium (non-selective K(+) channel blocker) or 1 mM aminopyridine (inhibitor of K(v) channels), but not by 1 microM glibenclamide (inhibitor of K(ATP) channels) or 50 nM iberiotoxin (inhibitor of K(Ca) channels). Arterial smooth muscle expressed messengers for Kv1.2, Kv1.3, Kv1.4, Kv1.5 and Kv1.6, and proteins of Kv1.1, Kv1.2 and Kv1.4. CaCl(2) (10 microM- 10 mM) induced concentration-dependent contraction in Ca(2+)-free, depolarizing (50 mM KCl) medium. Sildenafil (0.1-100 microM) produced reversible concentration-dependent inhibition of the response to CaCl(2), which was completely abolished by the highest sildenafil concentration. By contrast, only 100 microM zaprinast inhibited the response to CaCl(2). The L-type Ca(2+) channel activator Bay K 8644 (0.1 nM-1 microM) induced concentration-dependent potentiation of the response to CaCl(2) inhibited by 100 microM sildenafil. Moreover, Bay K 8644 (0.1 nM-1 microM) induced concentration-dependent contraction in slightly depolarizing (15 mM) medium, which was inhibited to the same extent and in a concentration-dependent way by sildenafil (0.1-100 microM) and zaprinast (1 or 100 microM). These results show that sildenafil relaxes the rabbit basilar artery by

  13. Global distribution of beryllium isotopes in deep ocean water as derived from Fe-Mn crusts

    USGS Publications Warehouse

    Von Blanckenburg, F.; O'Nions, R. K.; Belshaw, N.S.; Gibb, A.; Hein, J.R.

    1996-01-01

    The direct measurement of the ratio of cosmogenic 10Be (T1/2 = 1.5 Ma) to stable terrigenously sourced 9Be in deep seawater or marine deposits can be used to trace water mass movements and to quantify the incorporation of trace metals into the deep sea. In this study a SIMS-based technique has been used to determine the 10Be/9Be ratios of the outermost millimetre of hydrogenetic ferromanganese crusts from the worlds oceans. 10Be/9Be ratios, time-corrected for radioactive decay of cosmogenic 10Be using 234U/ 238U, are in good agreement with AMS measurements of modern deep seawater. Ratios are relatively low in the North and equatorial Atlantic samples (0.4-0.5 ?? 10-7). In the Southwest Atlantic ratios increase up to 1 ?? 10-7, they vary between 0.7 and 1.0 ?? 10-7 in Indian Ocean samples, and have a near constant value of 1.1 ?? 0.2 ?? 10-7 for all Pacific samples. If the residence time of 10Be (??10Be) in deep water is constant globally, then the observed variations in 10Be/9Be ratios could be caused by accumulation of 10Be in deep water as it flows and ages along the conveyor, following a transient depletion upon its formation in the Northern Atlantic. In this view both 10Be and 9Be reach local steady-state concentration in Pacific deep water and the global ??10Be ??? 600 a. An alternative possibility is that the Be isotope abundances are controlled by local scavenging. For this scenario ??10Be would vary according to local particle concentration and would ??? 600 a in the central Pacific, but ??10Be ??? 230 a in the Atlantic. Mass balance considerations indicate that hydrothermal additions of 9Be to the oceans are negligible and that the dissolved riverine source is also small. Furthermore, aeolian dust input of 9Be appears insufficient to provide the dissolved Be inventory. The dissolution of only a small proportion (2%) of river-derived particulates could in principle supply the observed seawater Be content. If true, ocean margins would be the sites for 9Be

  14. NR4A nuclear receptors mediate carnitine palmitoyltransferase 1A gene expression by the rexinoid HX600

    SciTech Connect

    Ishizawa, Michiyasu; Kagechika, Hiroyuki; Makishima, Makoto

    2012-02-24

    Highlights: Black-Right-Pointing-Pointer The function of RXR heterodimers with NR4 receptors remains unknown. Black-Right-Pointing-Pointer The RXR ligand HX600 induces expression of carnitine palmitoyltransferase 1A (CPT1A). Black-Right-Pointing-Pointer HX600-induced CPT1A expression is mediated by the NR4 receptors, Nur77 and NURR1. Black-Right-Pointing-Pointer CPT1A induction by HX600 is not mediated by de novo protein synthesis. Black-Right-Pointing-Pointer CPT1A could be a target of the Nur77-RXR and NURR1-RXR heterodimers. -- Abstract: Retinoid X receptors (RXRs) are members of the nuclear receptor superfamily and can be activated by 9-cis retinoic acid (9CRA). RXRs form homodimers and heterodimers with other nuclear receptors such as the retinoic acid receptor and NR4 subfamily nuclear receptors, Nur77 and NURR1. Potential physiological roles of the Nur77-RXR and NURR1-RXR heterodimers have not been elucidated. In this study, we identified a gene regulated by these heterodimers utilizing HX600, a selective RXR agonist for Nur77-RXR and NURR1-RXR. While 9CRA induced many genes, including RAR-target genes, HX600 effectively induced only carnitine palmitoyltransferase 1A (CPT1A) in human teratocarcinoma NT2/D1 cells, which express RXR{alpha}, Nur77 and NURR1. HX600 also increased CPT1A expression in human embryonic kidney (HEK) 293 cells and hepatocyte-derived HepG2 cells. Although HX600 induced CPT1A less effectively than 9CRA, overexpression of Nur77 or NURR1 increased the HX600 response to levels similar to 9CRA in NT2/D1 and HEK293 cells. A dominant-negative form of Nur77 or NURR1 repressed the induction of CPT1A by HX600. A protein synthesis inhibitor did not alter HX600-dependent CPT1A induction. Thus, the rexinoid HX600 directly induces expression of CPT1A through a Nur77 or NURR1-mediated mechanism. CPT1A, a gene involved in fatty acid {beta}-oxidation, could be a target of RXR-NR4 receptor heterodimers.

  15. The β Pictoris association: Catalog of photometric rotational periods of low-mass members and candidate members

    NASA Astrophysics Data System (ADS)

    Messina, S.; Millward, M.; Buccino, A.; Zhang, L.; Medhi, B. J.; Jofré, E.; Petrucci, R.; Pi, Q.; Hambsch, F.-J.; Kehusmaa, P.; Harlingten, C.; Artemenko, S.; Curtis, I.; Hentunen, V.-P.; Malo, L.; Mauas, P.; Monard, B.; Muro Serrano, M.; Naves, R.; Santallo, R.; Savuskin, A.; Tan, T. G.

    2017-04-01

    Aims: We intended to compile the most complete catalog of bona fide members and candidate members of the β Pictoris association, and to measure their rotation periods and basic properties from our own observations, public archives, and exploring the literature. Methods: We carried out a multi-observatories campaign to get our own photometric time series and collected all archived public photometric data time series for the stars in our catalog. Each time series was analyzed with the Lomb-Scargle and CLEAN periodograms to search for the stellar rotation periods. We complemented the measured rotational properties with detailed information on multiplicity, membership, and projected rotational velocity available in the literature and discussed star by star. Results: We measured the rotation periods of 112 out of 117 among bona fide members and candidate members of the β Pictoris association and, whenever possible, we also measured the luminosity, radius, and inclination of the stellar rotation axis. This represents to date the largest catalog of rotation periods of any young loose stellar association. Conclusions: We provided an extensive catalog of rotation periods together with other relevant basic properties useful to explore a number of open issues, such as the causes of spread of rotation periods among coeval stars, evolution of angular momentum, and lithium-rotation connection. Tables 1 and 2 are also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A83Table 3 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A83Based on observations obtained at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientique of France, and

  16. Evaluation of a newly available biochemical analyzer: the Olympus AU 600.

    PubMed

    Blanc, M C; Neveux, N; Laromiguière, M; Bérard, M P; Cynober, L

    2000-05-01

    The performance of the Olympus AU 600, a newly available open multiparametric analyzer, available for routine biochemical analysis of biological samples, was evaluated. The analytical and technical performance of the apparatus and the quality of the Olympus reagents were both examined in a single site study. Electrolyte concentrations were determined with patented ion-selective electrodes; substrate concentrations and enzyme activities were determined by spectrophotometric measurement after coloured reaction or UV detection-based-reactions. The protocol of the evaluation and the acceptability criteria were those recommended by the French Society for Clinical Biology. For the parameters studied, the upper limits of linearity were equal to or higher than those claimed by the manufacturer. The CV values for within-run and between-run precision were lower than the target values with few exceptions. The comparison study gave satisfactory results for most of the parameters. Only expected interferences occurred. In summary, the results obtained for the 25 parameters studied and the characteristics of the apparatus were satisfactory. The analyzer is rapid (800 to 1200 tests per hour) and easy to use. In addition, the analyzer complies with good analytical practice and its flexibility enables users to plan work according to local laboratory constraints.

  17. Triggering GaAs lock-on switches with laser diode arrays

    SciTech Connect

    Loubriel, G.M.; Buttram, M.T.; Helgeson, W.D.; McLaughlin, D.L.; O'Malley, M.W.; Zutavern, F.J. ); Rosen, A.; Stabile, P.J. )

    1990-01-01

    Laser diode arrays have been used to trigger GaAs Photoconducting Semiconductor Switches (PCSS) charged to voltages of up to 60 kV and conducting currents of 580 A. The driving forces behind the use of laser diode arrays are compactness, elimination of complicated optics, and the ability to run at high repetition rates. Laser diode arrays are compactness, elimination of complicated optics, and the ability to run at high repetition rates. Laser diode arrays can trigger GaAs at high fields as the result of a new switching mode (lock-on) with very high carrier number gain. We have achieved switching of up to 10 MW in a 60 {Omega} system, with a pulse rise time of 500 ps. At 1.2 MW we have achieved repetition rates of 1 kHz with switch rise time of 500 ps for 10{sup 5} shots. The laser diode array used for these experiments delivers a 166 W pulse. In a single shot mode we have switched 4 kA with a flash lamp pumped laser and 600 A with the 166 W array. 7 refs., 5 figs.

  18. Preparation of SrZrO3 Thermal Barrier Coating by Solution Precursor Plasma Spray

    NASA Astrophysics Data System (ADS)

    Li, Xinhui; Ma, Wen; Wen, Jing; Bai, Yu; Sun, Li; Chen, Baodong; Dong, Hongying; Shuang, Yingchai

    2017-02-01

    The solution precursor plasma spray (SPPS) process is capable of depositing highly durable thermal barrier coatings (TBCs). In this study, an aqueous chemical precursor feedstock was injected into the plasma jet to deposit SrZrO3 thermal barrier coating on metal substrate. Taguchi design of experiments was employed to optimize the SPPS process. The thermal characteristics and phase evolution of the SrZrO3 precursor, as well as the influence of various spray parameters on the coating deposition rate, microhardness, microstructure, and phase stability, were investigated. The experimental results showed that, at given spray distance, feedstock flow rate, and atomization pressure, the optimized spray parameters were arc current of 600 A, argon flow rate of 40 L/min, and hydrogen flow rate of 10 L/min. The SrZrO3 coating prepared using the optimized spray parameters had single-pass thickness of 6.0 μm, porosity of 18%, and microhardness of 6.8 ± 0.1 GPa. Phase stability studies indicated that the as-sprayed SrZrO3 coating had good phase stability in the temperature range from room temperature to 1400 °C, gradually exhibiting a phase transition from t'-ZrO2 to m-ZrO2 in the SrZrO3 coating at 1450 °C with increasing time, while the SrZrO3 phase did not change.

  19. Improved superconducting magnet wire

    DOEpatents

    Schuller, I.K.; Ketterson, J.B.

    1983-08-16

    This invention is directed to a superconducting tape or wire composed of alternating layers of copper and a niobium-containing superconductor such as niobium of NbTi, Nb/sub 3/Sn or Nb/sub 3/Ge. In general, each layer of the niobium-containing superconductor has a thickness in the range of about 0.05 to 1.5 times its coherence length (which for Nb/sub 3/Si is 41 A) with each copper layer having a thickness in the range of about 170 to 600 A. With the use of very thin layers of the niobium composition having a thickness within the desired range, the critical field (H/sub c/) may be increased by factors of 2 to 4. Also, the thin layers of the superconductor permit the resulting tape or wire to exhibit suitable ductility for winding on a magnet core. These compositions are also characterized by relatively high values of critical temperature and therefore will exhibit a combination of useful properties as superconductors.

  20. Characteristics of a Plasma Torch Designed for Very Low Pressure Plasma Spraying

    NASA Astrophysics Data System (ADS)

    Gao, Yang; Yang, De Ming; Gao, Jianyi

    2012-06-01

    Unlike atmosphere plasma spraying (APS), very low pressure plasma spraying (VLPPS) can only weakly heat the feed materials at the plasma-free region exit of the nozzle. Most current VLPPS methods have adopted a high power plasma gun, which operates at high arc currents up to 2500 A to remedy the lower heating ability, causing a series of problems for both the plasma torch and the associated facility. According to the Kundsen number and pressures distribution inside of the nozzle in a low-pressure environment, a plasma torch was designed with a separated anode and nozzle, and with the powder feed to the plasma jets inside the nozzle intake. In this study, the pressures in the plasma gas intake, in the nozzle intake and outside the plasma torch were measured using an enthalpy probe. For practice, SUS 316 stainless steel coatings were prepared at the plasma currents of 500-600 A, an arc voltage of 50 V and a chamber pressure of 1000 Pa; the results indicated that coatings with an equiaxed microstructure could be deposited in proper conditions.

  1. Characterisation of a grooved heat pipe with an anodised surface

    NASA Astrophysics Data System (ADS)

    Solomon, A. Brusly; Ram Kumar, A. M.; Ramachandran, K.; Pillai, B. C.; Senthil Kumar, C.; Sharifpur, Mohsen; Meyer, Josua P.

    2017-03-01

    A grooved heat pipe (GHP) is an important device for managing heat in space applications such as satellites and space stations, as it works efficiently in the absence of gravity. Apart from the above application, axial GHPs are used in many applications, such as electronic cooling units for temperature control and permafrost cooling. Improving the performance of GHPs is essential for better cooling and thermal management. In the present study, the effect of anodization on the heat transfer characteristics of a GHP is studied with R600a as a working fluid. In addition, the effects of fill ratio, inclination angle and heat inputs on the heat transfer performance of a GHP are studied. Furthermore, the effect of heat flux on dimensional numbers, such as the Webber, Bond, Kutateladze and condensation numbers, are studied. The inclination angle, heat input and fill ratio of GHPs are varied in the range of 0°-90°, 25-250 W and 10-70 % respectively. It is found that the above parameters have a significant effect on the performance of a GHP. Due to the anodisation, the maximum enhancement in heat transfer coefficient at the evaporator is 39 % for a 90° inclination at a heat flux of 11 kW/m2. The reported performance enhancement of a GHP may be due to the large numbers of nucleation sites created by the anodisation process and enhancement in the capillary force due to the coating.

  2. Dip-coated multi-core (Bi,Pb) 2Sr 2Ca 2Cu 3O x tape process - an alternative way of fabricating multi-core (Bi,Pb) 2Sr 2Ca 2Cu 3O x tape conductors

    NASA Astrophysics Data System (ADS)

    Sung, Y. S.; Kumakura, H.; Togano, K.

    2000-04-01

    The dip-coating-then-stacking (DIS) process, which is simpler and easier than the oxide-powder-in-tube (OPIT) process, was developed to fabricate multi-core (Bi,Pb) 2Sr 2Ca 2Cu 3O x conductors. In the DIS process, multi-core tapes were prepared by stacking several layers of single side dip-coated Ag strips then wrapping them with Ag foil. After burning at 500°C to remove organic materials, tape samples were rolled to increase the packing density of oxide core, then were heat-treated twice at 838°C in air with an intermediate pressing. There was no bubbling problem throughout the heat treatment and the interface between oxide core and Ag was very smooth. By the DIS process, transport critical current ( Ic) ∼73 A and transport critical current density ( Jc) ∼17 600 A/cm 2 at 77 K, 0 T were so far obtained. Considering the easiness and simplicity of the DIS process relative to OPIT with reasonably high Ic and Jc values so far obtained, it appears that the DIS process can be applied as an alternative way to OPIT for fabricating multi-core (Bi,Pb) 2Sr 2Ca 2Cu 3O x tape conductors.

  3. Gas chromatographic measurements of activity coefficients at infinite dilution for refrigerants with a polyol ester oil as a stationary phase

    SciTech Connect

    Stryjek, R.; Bobbo, S.; Camporese, R.; Zilio, C.

    1999-05-01

    Activity coefficients at infinite dilution have been measured by gas chromatography for 14 refrigerants (R12, R22, R32, R124, R125, R134a, R142b, R143a, RE170, R236ea, R290, R600, R600a, and R236fa) as solutes, using a polyol ester oil (POE), EMKARATE by ICI, as a stationary phase (solvent). Instrumental analysis (NMR, IR) showed that the main components of the oil are pentaerithritol esters of carboxylic acids, and electrospray ionization spectrometry revealed an average molecular mass of the POE of 618 g/mol. The measurements were performed within a temperature range of 244 K to 313 K, but a specific temperature range for each refrigerant was adopted depending on its retention data. The experimental findings are well-represented by the equation: ln {gamma}{sub i}{sup {infinity}} = a{sub i} {minus} b{sub i}/T. Some refrigerants, i.e., R22, R124, R125, R236ea, and R236fa, show quite a considerable positive temperature dependence of their activity coefficients at infinite dilution, which can be attributed to hydrogen bonding with the POE, unlike other refrigerants that show a small, either positive or negative temperature dependence. To the authors` knowledge, there are no data in the literature on activity coefficients at infinite dilution for refrigerant and oil (lubricant) systems, and details on the solubility of refrigerants in oils are also extremely scarce.

  4. The pygmy dipole resonance in 68Ni and the neutron skin

    NASA Astrophysics Data System (ADS)

    Wieland, O.; Bracco, A.

    2011-04-01

    A search of the pygmy resonance in 68Ni was made using the virtual photon technique. The experiment was carried out using the radioactive beam 68Ni at 600 A MeV, produced with fragmentation of 86Kr at 900 A MeV on a 9Be target. The 68Ni beam was separated by a fragment separator, and the γ-rays produced at the interaction with the Au target were detected with the RISING and FRS set-up at the GSI laboratory in Germany, also including the HECTOR array. The measured γ-ray spectra show a peak centered at approximately 11 MeV, whose intensity can be explained in term of an enhanced strength of the dipole response function (pygmy resonance). A pygmy structure of this type was also predicted by different models for this unstable neutron-rich nucleus. Correlations between the behavior of the nuclear symmetry energy, the neutron skins, and the percentage of energy-weighted sum rule (EWSR) exhausted by the pygmy dipole resonance (PDR) are investigated by using different random phase approximation (RPA) models.

  5. Imaging extreme ultraviolet spectrometer employing a single toroidal diffraction grating: the initial evaluation.

    PubMed

    Huber, M C; Timothy, J G; Morgan, J S; Lemaitre, G; Tondello, G; Jannitti, E; Scarin, P

    1988-08-15

    A high-efficiency extreme ultraviolet (EUV) imaging spectrometer has been constructed and tested. The spectrometer employs a concave toroidal grating illuminated at normal incidence in a Rowland circle mounting and has only one reflecting surface. The toroidal grating has been fabricated by a new technique employing an elastically deformable submaster grating which is replicated in a spherical form and then mechanically distorted to produce the desired aspect ratio of the toroidal surface for stigmatic imaging over the selected wavelength range. The fixed toroidal grating used in the spectrometer is then replicated from this surface. Photographic tests and initial photoelectric tests with a 2-D pulse-counting detector system have verified the image quality of the toroidal grating at wavelengths near 600 A. The results of these initial tests are described in detail, and the basic designs of two instruments which could employ the imaging spectrometer for astrophysical investigations in space are briefly described, namely, a high-resolution EUV spectroheliometer for studies of the solar chromosphere, transition region, and corona and an EUV spectroscopic telescope for studies of nonsolar objects.

  6. Flight Calibration of the LROC Narrow Angle Camera

    NASA Astrophysics Data System (ADS)

    Humm, D. C.; Tschimmel, M.; Brylow, S. M.; Mahanti, P.; Tran, T. N.; Braden, S. E.; Wiseman, S.; Danton, J.; Eliason, E. M.; Robinson, M. S.

    2016-04-01

    Characterization and calibration are vital for instrument commanding and image interpretation in remote sensing. The Lunar Reconnaissance Orbiter Camera Narrow Angle Camera (LROC NAC) takes 500 Mpixel greyscale images of lunar scenes at 0.5 meters/pixel. It uses two nominally identical line scan cameras for a larger crosstrack field of view. Stray light, spatial crosstalk, and nonlinearity were characterized using flight images of the Earth and the lunar limb. These are important for imaging shadowed craters, studying ˜1 meter size objects, and photometry respectively. Background, nonlinearity, and flatfield corrections have been implemented in the calibration pipeline. An eight-column pattern in the background is corrected. The detector is linear for DN = 600--2000 but a signal-dependent additive correction is required and applied for DN<600. A predictive model of detector temperature and dark level was developed to command dark level offset. This avoids images with a cutoff at DN=0 and minimizes quantization error in companding. Absolute radiometric calibration is derived from comparison of NAC images with ground-based images taken with the Robotic Lunar Observatory (ROLO) at much lower spatial resolution but with the same photometric angles.

  7. Descriptive Summaries for Program Elements of the Research, Development, Test and Evaluation, Army Program FY 1981. Volume I.

    DTIC Science & Technology

    1980-01-01

    6 蕨 . 𔄃 . 4. 19 𔃿a U54.454 k. J6-U 66 06 2 0-1 * 0 0. 1- 6U4 0 A62 05 Iw o 46 15 05 6.2 A600- A.4D, &j 0) IL1 04. a- v 0.a0 !I ’A.11 0 16 E’o 0...0 CL~ 2.0 c 6.. a " P.. 66666 0.5 to .4 a 60 3 1 6Id C0 a’ 4. 0. 4- L.E I 1 0 4 6 .0 i0I0 " 66 ay~ -04 00 b.~C 13 IS . .4 s,6 0 𔃿 05 9 .25" a0... 05 aU U UU A ll. * Id I U A.WU U.14.6 C. CI U~~~~ MU rC C U C C C C. USC .. UZA U’C C t U to . ". Cz ..U UUU Go Go 9C2 Id ~ 4C U W -UU A 41~~ Go. OC

  8. A Green's function method for heavy ion beam transport

    NASA Technical Reports Server (NTRS)

    Shinn, J. L.; Wilson, J. W.; Schimmerling, W.; Shavers, M. R.; Miller, J.; Benton, E. V.; Frank, A. L.; Badavi, F. F.

    1995-01-01

    The use of Green's function has played a fundamental role in transport calculations for high-charge high-energy (HZE) ions. Two recent developments have greatly advanced the practical aspects of implementation of these methods. The first was the formulation of a closed-form solution as a multiple fragmentation perturbation series. The second was the effective summation of the closed-form solution through nonperturbative techniques. The nonperturbative methods have been recently extended to an inhomogeneous, two-layer transport media to simulate the lead scattering foil present in the Lawrence Berkeley Laboratories (LBL) biomedical beam line used for cancer therapy. Such inhomogeneous codes are necessary for astronaut shielding in space. The transport codes utilize the Langley Research Center atomic and nuclear database. Transport code and database evaluation are performed by comparison with experiments performed at the LBL Bevalac facility using 670 A MeV 20Ne and 600 A MeV 56Fe ion beams. The comparison with a time-of-flight and delta E detector measurement for the 20Ne beam and the plastic nuclear track detectors for 56Fe show agreement up to 35%-40% in water and aluminium targets, respectively.

  9. Canopy profiles of photosynthetic parameters under elevated CO2 and N fertilization in a poplar plantation.

    PubMed

    Calfapietra, Carlo; Tulva, Ingmar; Eensalu, Eve; Perez, Marta; De Angelis, Paolo; Scarascia-Mugnozza, Giuseppe; Kull, Olevi

    2005-10-01

    A poplar plantation has been exposed to an elevated CO2 concentration for 5 years using the free air CO2 enrichment (FACE) technique. Even after such a long period of exposure, leaves of Populus x euramericana have not shown clear signs of photosynthetic acclimation. Only at the end of the growing season for shade leaves was a decrease of maximum velocity of carboxylation (Vcmax) observed. Maximum electron transport rate (Jmax) was increased by FACE treatment in July. Assimilation rates at CO2 partial pressure of 400 (A400) and 600 (A600) micromol mol(-1) were not significantly different under FACE treatment. Most notably FACE significantly decreased stomatal conductance (g(s)) both on upper and lower canopy leaves. N fertilization increased N content in the leaves on mass basis (Nm) and specific leaf area (SLA) in both CO2 treatments but did not influence the photosynthetic parameters. These data show that in poplar plantations the long-term effects of elevated CO2 on photosynthesis do not differ considerably from the short-term ones even with N deposition.

  10. Solar thermal organic rankine cycle for micro-generation

    NASA Astrophysics Data System (ADS)

    Alkahli, N. A.; Abdullah, H.; Darus, A. N.; Jalaludin, A. F.

    2012-06-01

    The conceptual design of an Organic Rankine Cycle (ORC) driven by solar thermal energy is developed for the decentralized production of electricity of up to 50 kW. Conventional Rankine Cycle uses water as the working fluid whereas ORC uses organic compound as the working fluid and it is particularly suitable for low temperature applications. The ORC and the solar collector will be sized according to the solar flux distribution in the Republic of Yemen for the required power output of 50 kW. This will be a micro power generation system that consists of two cycles, the solar thermal cycle that harness solar energy and the power cycle, which is the ORC that generates electricity. As for the solar thermal cycle, heat transfer fluid (HTF) circulates the cycle while absorbing thermal energy from the sun through a parabolic trough collector and then storing it in a thermal storage to increase system efficiency and maintains system operation during low radiation. The heat is then transferred to the organic fluid in the ORC via a heat exchanger. The organic fluids to be used and analyzed in the ORC are hydrocarbons R600a and R290.

  11. Practical applications of SiC-MOSFETs and further developments

    NASA Astrophysics Data System (ADS)

    Furuhashi, Masayuki; Tomohisa, Shingo; Kuroiwa, Takeharu; Yamakawa, Satoshi

    2016-03-01

    The next generation power modules using SiC-MOSFETs have been developed for over ten years. From our successful results, we have released SiC power modules which have been used in railway vehicles, industrial machines and home appliances, etc. Low on-resistance 3.3 kV SiC-MOSFETs have been realized by JFET doping and they demonstrated a loss reduction of 55% in a traction inverter compared to a conventional system. In the case of a 1.2 kV MOSFET, a 1 cm2 die verified that it can control a large current of over 600 A. For home appliances, we reduce the trade-off between the threshold voltage and channel mobility by a new gate oxide process. High threshold voltage SiC-MOSFETs having a low on-resistance contribute to the low cost installation of SiC-MOSFETs into air conditioners and achieved a loss reduction of 45% in DC converters. For further reduction of conduction loss, we investigated new structures and technologies. Trench SiC-MOSFETs having a bottom p-well verify lower on-resistance and a larger SCSOA than those of planar MOSFETs. The optimization of the dopant concentration in the drift layer and a reduction of wafer thickness verified the reduction of on-resistance. They are expected to contribute to a lower power loss.

  12. An imaging extreme ultraviolet spectrometer for astrophysical investigations in space

    NASA Technical Reports Server (NTRS)

    Huber, M. C. E.; Timothy, J. G.; Morgan, J. S.; Lemaitre, G.; Tondello, G.

    1986-01-01

    A high-efficiency, extreme ultraviolet (EUV) imaging spectrometer has been constructed and tested. The spectrometer employs a concave toroidal grating illuminated at normal incidence in a Rowland circle mounting and has only one reflecting surface. The toroidal grating has been fabricated by a new technique employing an elastically deformable submaster grating which is replicated in a spherical form and then mechanically distorted to produce the desired aspect ratio of the toroidal surface for stigmatic imaging over the selected wavelength range. The fixed toroidal grating used in the spectrometer is then replicated from this surface. Photographic tests and initial photoelectric tests with a two-dimensional, pulse-counting detector system have verified the image quality of the toroidal grating at wavelengths near 600 A. The basic designs of two instruments employing the spectrometer for astrophysical investigations in space are described, namely, a high-resolution EUV spectroheliometer for studies of the solar chromosphere, transition region, and corona; and an EUV spectroscopic telescope for studies of nonsolar objects.

  13. Assessment of E-coding practices and costs in Massachusetts hospitals.

    PubMed Central

    Ozonoff, V V; Tan-Torres, S; Barber, C W

    1993-01-01

    Hospital discharge data are a potentially useful information resource for documenting the epidemiology of nonfatal injuries. However, hospitals often do not include E-codes that identify external causes of injury in discharge abstracts. One barrier has been assumed to be the cost of assigning E-codes to medical records. Directors of medical records at hospitals in Massachusetts were surveyed to assess the validity of a cost-assessment study by Rivara and coworkers and to determine what resources they would need to E-code all injury discharges. According to Rivara's estimates, injury coding an additional 500 hospital discharges would entail a continuing cost to each hospital of about $600 a year. More than half of the survey's 101 respondents believed that the estimates were accurate, 16 percent believed that the estimates were inaccurate, and 27 percent were unable to assess the potential costs. Among the resources needed to E-code all injury-related discharges, respondents most often cited training for those who assign the codes and the approval of the hospital administration. Only 20 percent of the respondents cited needs directly related to ongoing costs. The perception by hospitals of the cost of E-coding, frequently cited as a major barrier to the use of hospital discharge data as an injury surveillance source, did not emerge in this survey as an overriding concern. PMID:8210261

  14. Direct simulation of initial value problems for the motion of solid bodies in a Newtonian fluid part 1. Sedimentation

    NASA Astrophysics Data System (ADS)

    Feng, J.; Hu, H. H.; Joseph, D. D.

    1994-02-01

    This paper reports the result of direct simulations of fluid-particle motions in two dimensions. We solve the initial value problem for the sedimentation of circular and elliptical particles in a vertical channel. The fluid motion is computed from the Navier-Stokes equations for moderate Reynolds numbers in the hundreds. The particles are moved according to the equations of motion of a rigid body under the action of gravity and hydrodynamic forces arising from the motion of the fluid. The solutions are as exact as our finite-element calculations will allow. As the Reynolds number is increased to 600, a circular particle can be said to experience five different regimes of motion: steady motion with and without overshoot and weak, strong and irregular oscillations. An elliptic particle always turn its long axis perpendicular to the fall, and drifts to the centreline of the channel during sedimentation. Steady drift, damped oscillation and periodic oscillation of the particle are observed for different ranges of the Reynolds number. For two particles which interact while settling, a steady staggered structure, a periodic wake-action regime and an active drafting-kissing-tumbling scenario are realized at increasing Reynolds numbers. The nonlinear effects of particle-fluid, particle-wall and interparticle interactions are analyzed, and the mechanisms controlling the simulated flows are shown to be lubrication, turning couples on long bodies, steady and unsteady wakes and wake interactions. The results are compared to experimental and theoretical results previously published.

  15. Feasibility of drying system using waste heat as the heating source

    NASA Astrophysics Data System (ADS)

    Xie, M. N.; Shi, Y. L.; Chen, L. X.

    2016-08-01

    In this study, a wastewater heat pump system was proposed and its thermal performance was analyzed. The proposed system includes two evaporators: an air-source evaporator and a water-source evaporator. The air-source evaporator absorbs heat from the moist hot air which exhaust from the drying oven. The water-source evaporator absorbs heat from the waste water, while the waste water recovers heat from the mechanical energy, which was produced by cutting and polishing in stone production. The thermodynamic model was developed to evaluate the performance of the proposed system. The energetic analysis was carried out to investigate the influences of the temperature of fresh air. The results show significantly higher energy efficiency, compact-sized and energy-saving compared with the system which uses air as the heat source. Among the seven of alternative refrigerants (R152a, R123, R1234yf, R1234ze, R600a, R22 and R600) investigated, R123 was suggested to be used in this heat pump for its high heating efficiency, inflammable, very low ODP(Ozone Depletion Potential) and GWP(Global warming potential).

  16. Packing forces in nine crystal forms of cutinase.

    PubMed

    Jelsch, C; Longhi, S; Cambillau, C

    1998-05-15

    During the characterization of mutants and covalently inhibited complexes of Fusarium solani cutinase, nine different crystal forms have been obtained so far. Protein mutants with a different surface charge distribution form new intermolecular salt bridges or long-range electrostatic interactions that are accompanied by a change in the crystal packing. The whole protein surface is involved in the packing contacts and the hydrophobicities of the protein surfaces in mutual contact turned out to be noncorrelated, which indicates that the packing interactions are nonspecific. In the case of the hydrophobic variants, the packing contacts showed some specificity, as the protein in the crystal tends to form either crystallographic or noncrystallographic dimers, which shield the hydrophobic surface from the solvent. The likelihood of surface atoms to be involved in a crystal contact is the same for both polar and nonpolar atoms. However, when taking areas in the 200-600 A2 range, instead of individual atoms, the either highly hydrophobic or highly polar surface regions were found to have an increased probability of establishing crystal lattice contacts. The protein surface surrounding the active-site crevice of cutinase constitutes a large hydrophobic area that is involved in packing contacts in all the various crystalline contexts.

  17. RF sputtered silicon and hafnium nitrides as applied to 440C steel

    NASA Technical Reports Server (NTRS)

    Grill, A.; Aron, P. R.

    1984-01-01

    Silicon nitride and hafnium nitride coatings were deposited on oxidized and unoxidized 440C stainless steel substrates. Sputtering was done in mixtures of argon and nitrogen gases from pressed powder silicon nitride and from hafnium metal targets. The coatings and the interface between the coating and substrate were investigated by X-ray diffractometry, scanning electron microscopy, energy dispersive X-ray analysis and Auger electron spectroscopy. Oxide was found at all interfaces with an interface width of at least 600 A for the oxidized substrates and at least 300 A for the unoxidized substrates. Scratch test results demonstrate that the adhesion of hafnium nitride to both oxidized and unoxidized 440C is superior to that of silicon nitride. Oxidized 440C is found to have increased adhesion, to both nitrides, over that of unoxidized 440C. Coatings of both nitrides deposited at 8 mtorr were found to have increased adhesion to both oxidized and unoxidized 440C over those deposited at 20 mtorr.

  18. SOLAR/SOLSPEC mission on ISS: In-flight performance for SSI measurements in the UV

    NASA Astrophysics Data System (ADS)

    Bolsée, D.; Pereira, N.; Gillotay, D.; Pandey, P.; Cessateur, G.; Foujols, T.; Bekki, S.; Hauchecorne, A.; Meftah, M.; Damé, L.; Hersé, M.; Michel, A.; Jacobs, C.; Sela, A.

    2017-03-01

    Context. The SOLar SPECtrum (SOLSPEC) experiment is part of the Solar Monitoring Observatory (SOLAR) payload, and has been externally mounted on the Columbus module of the International Space Station (ISS) since 2008. SOLAR/SOLSPEC combines three absolutely calibrated double monochromators with concave gratings for measuring the solar spectral irradiance (SSI) from 166 nm to 3088 nm. This physical quantity is a key input for studies of climatology, planetary atmospheres, and solar physics. Aims: A general description of the instrument is given, including in-flight operations and performance of the ultraviolet (UV) channel from 175 nm to 340 nm. Methods: We developed a range of processing and correction methods, which are described in detail. For example, methods for correcting thermal behavior effects, instrument linearity, and especially the accuracy of the wavelength and absolute radiometric scales have been validated by modeling the standard uncertainties. Results: The deliverable is a quiet Sun UV reference solar spectrum as measured by SOLAR/SOLSPEC during the minimum of solar activity prior to cycle 24. Comparisons with other instruments measuring SSI are also presented. The quiet Sun UV spectrum (FITS file) is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A21

  19. Abundance ratios of oxygen, neon, and magnesium in solar active regions and flares: The FIP effect

    NASA Technical Reports Server (NTRS)

    Widing, K. G.; Feldman, U.

    1995-01-01

    Relative abundances of oxygen, neon, and magnesium have been derived for a sample of nine solar active regions, flares, and an erupting prominance by combining plots of the ion differential emission measures. The observations were photographed in the 300-600 A range by the Naval Research Laboratory (NRL) spectroheliograph on Skylab. Methods for deriving the Mg/Ne abundance ratio-which measures the separation between the low- first ionization potential (FIP) and high-FIP abundnace plateaus-have been described in previous papers. In this paper we describe the spectroscopic methods for deriving the O/Ne abundance ratio, which gives the ratio between two high-FIP elements. The plot of the O/Ne ratio versus the Mg/Ne ratio in the sample of nine Skylab events is shown. The variation in the Mg/Ne ratio by a factor of 6 is associated with a much smaller range in the O/Ne ratio. This is broadly consistent with the presence of the standard FIP pattern of abundances in the outer atmosphere of the Sun. However, a real change in the relative abundances of oxygen and neon by a factor of 1.5 cannot be excluded.

  20. Fabrication of a Short-Period Nb3Sn Superconducting Undulator

    SciTech Connect

    Dietderich, Daniel; Dietderich, Daniel; Godeke, Arno; Prestemon, Soren; Pipersky, Paul T.; Liggins, Nate L.; Higley, Hugh C.; Marks, Steve; Schlueter, Ross D.

    2007-06-01

    Lawrence Berkeley National Laboratory develops high-field Nb{sub 3}Sn magnets for HEP applications. In the past few years, this experience has been extended to the design and fabrication of undulator magnets. Some undulator applications require devices that can operate in the presence of a heat load from a beam. The use of Nb{sub 3}Sn permits operation of a device at both a marginally higher temperature (5-8K) and a higher J{sub c}, compared to NbTi devices, without requiring a larger magnetic gap. A half-undulator device consisting of 6 periods (12 coil packs) of 14.5 mm period was designed, wound, reacted, potted and tested. It reached the short sample current limit of 717A in 4 quenches. The non-Cu Jc of the strand was over 7,600 A/mm{sup 2} and the Cu current density at quench was over 8,000 A/mm{sup 2}. Magnetic field models show that if a complete device was fabricated with the same parameters one could obtain beam fields of 1.1 T and 1.6 T for pole gaps of 8 mm and 6 mm, respectively.

  1. Separation of (44)Ti from proton irradiated scandium by using solid-phase extraction chromatography and design of (44)Ti/(44)Sc generator system.

    PubMed

    Radchenko, V; Meyer, C A L; Engle, J W; Naranjo, C M; Unc, G A; Mastren, T; Brugh, M; Birnbaum, E R; John, K D; Nortier, F M; Fassbender, M E

    2016-12-16

    Scandium-44g (half-life 3.97h [1]) shows promise for positron emission tomography (PET) imaging of longer biological processes than that of the current gold standard, (18)F, due to its favorable decay parameters. One source of (44g)Sc is the long-lived parent nuclide (44)Ti (half-life 60.0 a). A (44)Ti/(44g)Sc generator would have the ability to provide radionuclidically pure (44g)Sc on a daily basis. The production of (44)Ti via the (45)Sc(p,2n) reaction requires high proton beam currents and long irradiation times. Recovery and purification of no-carrier added (nca) (44)Ti from scandium metal targets involves complex separation chemistry. In this study, separation systems based on solid phase extraction chromatography were investigated, including branched diglycolamide (BDGA) resin and hydroxamate based ZR resin. Results indicate that ZR resin in HCl media represents an effective (44)Ti/(44g)Sc separation system.

  2. Influence of Rapid Thermal Ramp Rate on Phase Transformation of Titanium Silicides

    SciTech Connect

    Bailey, Glenn; Hu, Yao, Zhi; Smith, Paul Martin; Tay, Sing Pin; Thakur, Randhir; Yang, Jiting

    1999-05-03

    ULSI technology requires low resistance, stable silicides formed on small geometry lines. Titanium disilicide (TiSiz), which is the most widely used silicide for ULSI applications, exists in two crystallographic phases: the high resistance, metastable C49 phase and the low resistance, stable C54 phase. The major issue with TiSiz is the increasing thermal budget required to transform the C49 phase into the low resistance C54 phase as linewiths decrease below 0.25 pm. Annealing above 900"C to obtain this transformation often results in thermal degradation, so it is desirable to reduce the transformation temperature. The transformation temperature has been shown to be a fi.mction of many factors including microstructure, grain size, and impurities. In this paper we report an investig+ion of rapid thermal silicidation of titanium films (250, 400, and 600 A) on single crystalline silicon at temperatures from 300 to 1000"C. The ramp rates for these experiments are 5, 30, 70, and 200oC/s. The transformation temperature decreases as the ramp rate increases and as the initial film thickness increases. Scanning electron microscopy (SEM) is used to analyze the resultant film microstructure. The ramp rate influence on Ti silicidation is also investigated on polycrystalline Si lines with widths ranging from 0.27 to 3.0 pm.

  3. The underground electromagnetic pulse: Four representative models

    SciTech Connect

    Wouters, L.F.

    1989-06-01

    I describe four phenomenological models by which an underground nuclear explosion may generate electromagnetic pulses: Compton current asymmetry (or ''Compton dipole''); Uphole conductor currents (or ''casing currents''); Diamagnetic cavity plasma (or ''magnetic bubble''); and Large-scale ground motion (or ''magneto-acoustic wave''). I outline the corresponding analytic exercises and summarize the principal results of the computations. I used a 10-kt contained explosion as the fiducial case. Each analytic sequence developed an equivalent source dipole and calculated signal waveforms at representative ground-surface locations. As a comparative summary, the Compton dipole generates a peak source current moment of about 12,000 A/center dot/m in the submicrosecond time domain. The casing-current source model obtains an equivalent peak moment of about 2 /times/ 10/sup 5/ A/center dot/m in the 10- to 30-/mu/s domain. The magnetic bubble produces a magnetic dipole moment of about 7 /times/ 10/sup 6/ A/center dot/m/sup 2/, characterized by a 30-ms time structure. Finally, the magneto-acoustic wave corresponds to a magnetic dipole moment of about 600 A/center dot/m/sup 2/, with a waveform showing 0.5-s periodicities. 8 refs., 35 figs., 7 tabs.

  4. Electromagnetic pulse-induced current measurement device

    NASA Astrophysics Data System (ADS)

    Gandhi, Om P.; Chen, Jin Y.

    1991-08-01

    To develop safety guidelines for exposure to high fields associated with an electromagnetic pulse (EMP), it is necessary to devise techniques that would measure the peak current induced in the human body. The main focus of this project was to design, fabricate, and test a portable, self-contained stand-on device that would measure and hold the peak current and the integrated change Q. The design specifications of the EMP-Induced Current Measurement Device are as follows: rise time of the current pulse, 5 ns; peak current, 20-600 A; charge Q, 0-20 microcoulombs. The device uses a stand-on parallel-plate bilayer sensor and fast high-frequency circuit that are well-shielded against spurious responses to high incident fields. Since the polarity of the incident peak electric field of the EMP may be either positive or negative, the induced peak current can also be positive or negative. Therefore, the device is designed to respond to either of these polarities and measure and hold both the peak current and the integrated charge which are simultaneously displayed on two separate 3-1/2 digit displays. The prototype device has been preliminarily tested with the EMP's generated at the Air Force Weapons Laboratory (ALECS facility) at Kirtland AFB, New Mexico.

  5. Circadian patterns of ad libitum smoking by menstrual phase

    PubMed Central

    Allen, Alicia M.; Mooney, Marc; Chakraborty, Rima; Allen, Sharon S.

    2015-01-01

    Objective Recent research suggests nicotine metabolism may be influenced by sex hormones. Thus, we hypothesized that circadian smoking patterns would vary by menstrual phase. Methods Healthy female smokers (n = 31) between the ages of 18 and 40 with regular menstrual cycles, and not using hormones or psychotropic medications, were recruited for a randomized clinical study. Subjects recorded the time of each cigarette smoked and their menstrual phase with daily diaries prospectively for one complete menstrual cycle of ad libitum smoking. Analyses included Poisson regression to assess variations in the rate of smoking during waking hours (i.e., 6:00 a.m. and 12:00 midnight) and circadian smoking patterns by menstrual phase. Results Participants were 29.61 ± 5.44 years of age and smoked 16.93 ± 5.37 cigarettes per day. Participants had a lower rate of smoking during waking hours in the follicular phase as compared to the menses phase. There were no significant menstrual phase differences in the circadian smoking patterns. Conclusions These results offer further support for the influence of sex hormones on smoking behavior, but not on circadian patterns of smoking. Additional research is needed to study the direct relationship between nicotine metabolism, sex hormones, menstrual phase, and smoking behavior. PMID:19517420

  6. Studies of film formation in thionyl chloride electrolytes

    SciTech Connect

    Holleck, G.L.; Brady, K.D.

    1983-10-01

    Properties of protective surface films formed on in situ freshly exposed Li in LiA1C1/sub 4//SOC1/sub 2/ electrolytes were characterized using electrochemical transient techniques. Based on the results we propose a film model consisting of three regions. Region I forms rapidly (less than one hour) upon exposure of a fresh surface. It has a thickness between 200 and 400 A and an apparent resistivity of about2.10/sub 7/ ..cap omega..cm. It appears to have significant imperfection and some microporosity along the grain boundaries. This is followed by a Region II film which is more ordered and more compact. Its resistivity is about2.10/sub 8/ ..cap omega..cm and it grows to 200 to 600 A within a 20 hour period. Further growth is slow. The Region III film is porous and coarsely crystalline formed by dissolution and recrystallization of the Region II film. The Region III film does not contribute to the micropolarization measurements near the open circuit potential. The film growth kinetics can be described as a combination of a parabolic growth and a constant rate dissolution reaction.

  7. First long-term application of squeezed states of light in a gravitational-wave observatory.

    PubMed

    Grote, H; Danzmann, K; Dooley, K L; Schnabel, R; Slutsky, J; Vahlbruch, H

    2013-05-03

    We report on the first long-term application of squeezed vacuum states of light to improve the shot-noise-limited sensitivity of a gravitational-wave observatory. In particular, squeezed vacuum was applied to the German-British detector GEO 600 during a period of three months from June to August 2011, when GEO 600 was performing an observational run together with the French-Italian Virgo detector. In a second period, the squeezing application continued for about 11 months from November 2011 to October 2012. During this time, squeezed vacuum was applied for 90.2% (205.2 days total) of the time that science-quality data were acquired with GEO 600. A sensitivity increase from squeezed vacuum application was observed broadband above 400 Hz. The time average of gain in sensitivity was 26% (2.0 dB), determined in the frequency band from 3.7 to 4.0 kHz. This corresponds to a factor of 2 increase in the observed volume of the Universe for sources in the kHz region (e.g., supernovae, magnetars). We introduce three new techniques to enable the long-term application of squeezed light, and show that the glitch rate of the detector did not increase from squeezing application. Squeezed vacuum states of light have arrived as a permanent application, capable of increasing the astrophysical reach of gravitational-wave detectors.

  8. The evaluation of a deformable diffraction grating for a stigmatic EUV spectroheliometer

    NASA Technical Reports Server (NTRS)

    Timothy, J. G.

    1987-01-01

    A high-efficiency, extreme ultraviolet (EUV) imaging spectrometer is constructed and tested. The spectrometer employs a concave toroidal grating illuminated at normal incidence in a Rowland circle mounting and has only one reflecting surface. The toroidal grating has been fabricated by a new technique employing an elastically-deformable sub-master grating replicated in a spherical form and then mechanically distorted to produce the desired aspect ratio of the toroidal surface for stigmatic imaging over the selected wavelength range. The fixed toroidal grating used in the spectrometer is then replicated from this surface. Photographic tests and initial photoelectric tests with a two-dimensional, pulse-counting detector system verify the image quality of the toroidal grating at wavelengths near 600 A. The results of these tests and the basic designs of two instruments which could employ the imaging spectrometer for astrophysical investigations in space are described; i.e., a high-resolution EUV spectroheliometer for studies of the solar chromosphere, transition region, and corona; and an EUV spectroscopic telescope for studies of non-solar objects.

  9. A visualization instrument to investigate the mechanical-electro properties of high temperature superconducting tapes under multi-fields

    NASA Astrophysics Data System (ADS)

    Liu, Wei; Zhang, Xingyi; Liu, Cong; Zhang, Wentao; Zhou, Jun; Zhou, YouHe

    2016-07-01

    We construct a visible instrument to study the mechanical-electro behaviors of high temperature superconducting tape as a function of magnetic field, strain, and temperature. This apparatus is directly cooled by a commercial Gifford-McMahon cryocooler. The minimum temperature of sample can be 8.75 K. A proportion integration differentiation temperature control is used, which is capable of producing continuous variation of specimen temperature from 8.75 K to 300 K with an optional temperature sweep rate. We use an external loading device to stretch the superconducting tape quasi-statically with the maximum tension strain of 20%. A superconducting magnet manufactured by the NbTi strand is applied to provide magnetic field up to 5 T with a homogeneous range of 110 mm. The maximum fluctuation of the magnetic field is less than 1%. We design a kind of superconducting lead composed of YBa2Cu3O7-x coated conductor and beryllium copper alloy (BeCu) to transfer DC to the superconducting sample with the maximum value of 600 A. Most notably, this apparatus allows in situ observation of the electromagnetic property of superconducting tape using the classical magnetic-optical imaging.

  10. Evaluation of zinc addition to PWR primary coolant

    SciTech Connect

    Pathania, R.; Yagnik, S.; Gold, R.E.; Dove, M.; Kolstad, E.

    1995-12-31

    Laboratory studies have shown that addition of zinc to a PWR environment reduces the general corrosion rates of materials in the primary system and delays the initiation of primary water stress corrosion cracking (PWSCC) in Alloy 600. Because of the potential benefits of zinc addition in reducing radiation fields and mitigating PWSCC of Alloy 600 a project was initiated to qualify zinc addition to a PWR. The objective of this work was to evaluate the effect of zinc addition on radiation fields, PWSCC of Alloy 600 and fuel cladding corrosion at the Farley-2 PWR. In order to provide an early warning of any potential adverse effects on the fuel cladding, corrosion studies were initiated at the Halden test reactor prior to zinc addition at Farley-2. This paper provides an overview of the scope of the zinc addition demonstration at Farley-2 and the fuel cladding corrosion tests at Halden. The zinc concentration in the Farley-2 coolant is approximately 40 ppb and that in Halden is 50 ppb. The paper presents initial results from these studies which are still in progress.

  11. Type B accident investigation board report of the July 2, 1997 curium intake by shredder operator at Building 513 Lawrence Livermore National Laboratory, Livermore, California. Final report

    SciTech Connect

    1997-08-01

    On July 2, 1997 at approximately 6:00 A.M., two operators (Workers 1 and 2), wearing approved personal protective equipment (PPE), began a shredding operation of HEPA filters for volume reduction in Building 513 (B-513) at Lawrence Livermore National Laboratory (LLNL). The waste requisitions indicated they were shredding filters containing {le} 1 {micro}Ci of americium-241 (Am-241). A third operator (Worker 3) provided support to the shredder operators in the shredding area (hot area) from a room that was adjacent to the shredding area (cold area). At Approximately 8:00 A.M., a fourth operator (Worker 4) relieved Worker 2 in the shredding operation. Sometime between 8:30 A.M. and 9:00 A.M., Worker 3 left the cold area to make a phone call and set off a hand and foot counter in Building 514. Upon discovering the contamination, the shredding operation was stopped and surveys were conducted in the shredder area. Surveys conducted on the workers found significant levels of contamination on their PPE and the exterior of their respirator cartridges. An exit survey of Worker 1 was conducted at approximately 10:05 A.M., and found contamination on his PPE, as well as on the exterior and interior of his respirator. Contamination was also found on his face, chest, back of neck, hair, knees, and mustache. A nose blow indicated significant contamination, which was later determined to be curium-244.

  12. Comparative study of heat transfer and pressure drop during flow boiling and flow condensation in minichannels

    NASA Astrophysics Data System (ADS)

    Mikielewicz, Dariusz; Andrzejczyk, Rafał; Jakubowska, Blanka; Mikielewicz, Jarosław

    2014-09-01

    In the paper a method developed earlier by authors is applied to calculations of pressure drop and heat transfer coefficient for flow boiling and also flow condensation for some recent data collected from literature for such fluids as R404a, R600a, R290, R32,R134a, R1234yf and other. The modification of interface shear stresses between flow boiling and flow condensation in annular flow structure are considered through incorporation of the so called blowing parameter. The shear stress between vapor phase and liquid phase is generally a function of nonisothermal effects. The mechanism of modification of shear stresses at the vapor-liquid interface has been presented in detail. In case of annular flow it contributes to thickening and thinning of the liquid film, which corresponds to condensation and boiling respectively. There is also a different influence of heat flux on the modification of shear stress in the bubbly flow structure, where it affects bubble nucleation. In that case the effect of applied heat flux is considered. As a result a modified form of the two-phase flow multiplier is obtained, in which the nonadiabatic effect is clearly pronounced.

  13. The P600-as-P3 hypothesis revisited: single-trial analyses reveal that the late EEG positivity following linguistically deviant material is reaction time aligned.

    PubMed

    Sassenhagen, Jona; Schlesewsky, Matthias; Bornkessel-Schlesewsky, Ina

    2014-10-01

    The P600, a late positive ERP component following linguistically deviant stimuli, is commonly seen as indexing structural, high-level processes, e.g. of linguistic (re)analysis. It has also been identified with the P3 (P600-as-P3 hypothesis), which is thought to reflect a systemic neuromodulator release facilitating behavioural shifts and is usually response time aligned. We investigated single-trial alignment of the P600 to response, a critical prediction of the P600-as-P3 hypothesis. Participants heard sentences containing morphosyntactic and semantic violations and responded via a button press. The elicited P600 was perfectly response aligned, while an N400 following semantic deviations was stimulus aligned. This is, to our knowledge, the first single-trial analysis of language processing data using within-sentence behavioural responses as temporal covariates. Results support the P600-as-P3 perspective and thus constitute a step towards a neurophysiological grounding of language-related ERPs.

  14. Thermal and electrical influences from bulk plasma in cathode heating modeling

    NASA Astrophysics Data System (ADS)

    Chen, Tang; Wang, Cheng; Zhang, Xiao-Ning; Zhang, Hao; Xia, Wei-Dong

    2017-02-01

    In this paper, a numerical calculation is performed for the purpose of estimating the thermal and electrical influences from bulk plasma in cathode heating modeling, in other words researching the necessity of a coupling bulk plasma in near-cathode layer modeling. The proposed model applied in the present work is an improved one from previous work. In this model, the near-cathode region is divided into two parts: the sheath and the ionization layer. The Schottky effect at the cathode surface is considered based on the analytic solution of a 1D sheath model. It is noted that the arc column is calculated simultaneously in the near-cathode region and the cathode bulk. An application is presented for an atmospheric free burning argon arc with arc currents of 50 A-600 A. The modeling results show three interesting points: (1) at the cathode surface, energy transport due to heat conduction of heavy particles and electrons is comparable to total heating flux, no matter whether the arc discharge is performed in a high (400 A) or low current (50 A) situation; (2) the electrical influence from bulk plasma on the cathode heating modeling becomes obvious in a high current situation (>400 A) for the spot mode; (3) the near-cathode layer voltage drop ({{U}\\text{tot}} ) is larger in the diffuse mode than in the spot mode for the same current, which is just the opposite to that for decoupled modeling.

  15. Adsorption characteristics of Bisphenol-A on tailored activated carbon in aqueous solutions.

    PubMed

    Yan, Liang; Lv, Di; Huang, Xinwen; Shi, Huixiang; Zhang, Geshan

    2016-10-01

    The adsorption behavior of pharmaceuticals and personal care product, Bisphenol-A (BPA), according to four coal-based and four wood-based granular activated carbons modified using outgassing treatment, acidic treatment or alkaline treatment was studied. The adsorption isotherm results indicated that carbon surface acidity played a very important role in the adsorption of BPA. It was found that increasing surface acidity would increase the hydrogen bonding effects and increase adsorption of BPA on activated carbon. The acidic modified sample (F600-A and OLC-A) represented the best adsorption capacity, and the equilibrium adsorption amounts reached 346.42 and 338.55 mg/g, respectively. Further, effects of surface charge and surface basicity were examined. It was found that the adsorbed amount of BPA decreased with the increase of surface charge. Finally, there appeared to be a significant oligomerization phenomenon with BPA molecules onto the surface of activated carbon. OLC and OLC-OG, which have higher micropore percentages, are very effective in hampering the oligomerization of BPA under oxic conditions.

  16. Coexistence of a non-thermal jet and a complex ultra-fast X-ray outflow in a moderately luminous AGN

    NASA Astrophysics Data System (ADS)

    Giroletti, M.; Panessa, F.; Longinotti, A. L.; Krongold, Y.; Guainazzi, M.; Costantini, E.; Santos-Lleo, M.

    2017-04-01

    Context. Recent XMM-Newton observations have revealed that IRAS 17020+4544 is a very unusual example of black hole wind-produced feedback by a moderately luminous AGN in a spiral galaxy. Aims: Since the source is known to be a radio emitter, we investigated the presence and the properties of a non-thermal component. Methods: We observed IRAS 17020+4544 with the Very Long Baseline Array at 5, 8, 15, and 24 GHz within a month of the 2014 XMM-Newton observations. We further analysed archival data taken in 2000 and 2012. Results: We detect the source at 5 GHz and on short baselines at 8 GHz. At 15 and 24 GHz, the source is below our baseline sensitivity for fringe fitting, indicating a lack of prominent compact features. The morphology is that of an asymmetric double, with significant diffuse emission. The spectrum between 5 and 8 GHz is rather steep (S(ν) ν- (1.0 ± 0.2)). Our reanalysis of the archival data at 5 and 8 GHz provides results consistent with the new observations, suggesting that flux density and structural variability are not important in this source. We put a limit on the separation speed between the main components of <0.06c. Conclusions: IRAS 17020+4544 shows interesting features of several classes of objects: its properties are typical of compact steep spectrum sources, low power compact sources, and radio-emitting narrow line Seyfert 1 galaxies. However, it cannot be classified in any of these categories, and remains a one-of-a-kind object. Reduced images (FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A87 .

  17. Movements of wolves at the northern extreme of the species' range, including during four months of darkness

    USGS Publications Warehouse

    Mech, L.D.; Cluff, H.D.

    2011-01-01

    Information about wolf (Canis lupus) movements anywhere near the northern extreme of the species' range in the High Arctic (<75??N latitude) are lacking. There, wolves prey primarily on muskoxen (Ovibos moschatus) and must survive 4 months of 24 hr/day winter darkness and temperatures reaching -53 C. The extent to which wolves remain active and prey on muskoxen during the dark period are unknown, for the closest area where information is available about winter wolf movements is >2,250 km south. We studied a pack of ???20 wolves on Ellesmere Island, Nunavut, Canada (80??N latitude) from July 2009 through mid-April 2010 by collaring a lead wolf with a Global Positioning System (GPS)/Argos radio collar. The collar recorded the wolf's precise locations at 6:00 a.m. and 6:00 p.m. daily and transmitted the locations by satellite to our email. Straight-line distances between consecutive 12-hr locations varied between 0 and 76 km. Mean (SE) linear distance between consecutive locations (n = 554) was 11 (0.5) km. Total minimum distance traveled was 5,979 km, and total area covered was 6,640 km2, the largest wolf range reported. The wolf and presumably his pack once made a 263-km (straight-line distance) foray to the southeast during 19-28 January 2010, returning 29 January to 1 February at an average of 41 km/day straight-line distances between 12-hr locations. This study produced the first detailed movement information about any large mammal in the High Arctic, and the average movements during the dark period did not differ from those afterwards. Wolf movements during the dark period in the highest latitudes match those of the other seasons and generally those of wolves in lower latitudes, and, at least with the gross movements measurable by our methods, the 4-month period without direct sunlight produced little change in movements. ?? 2011 Mech, Cluff.

  18. Uncovering the Spectral Energy Distribution in Active Galaxies Using High Ionization Mid-Infrared Emission Lines

    NASA Technical Reports Server (NTRS)

    Melendez, M.; Kraemer, S. B.; Weaver, K. A.; Mushotzky, R. F.

    2011-01-01

    The shape of the spectral energy distribution of active galaxies in the EUV soft X-ray band (13.6 eV to 1 keV) is uncertain because obscuration by dust and gas can hamper our view of the continuum. To investigate the shape of the spectral energy distribution in this energy band, we have generated a set of photoionization models which reproduce the small dispersion found in correlations between high-ionization mid-infrared emission lines in a sample of hard X-ray selected AGN. Our calculations show that a broken power-law continuum model is sufficient to reproduce the [Ne V]14.32 microns/[Ne III], [Ne V]24.32 microns/[O IV]25.89 micron and [O IV] 25.89 microns/[Ne III] ratios, and does not require the addition of a "big bump" EUV model component. We constrain the EUV-soft X-ray slope, alpha(sub i), to be between 1.5 - 2.0 and derive a best fit of alpha(sub i) approx. 1.9 for Seyfert 1 galaxies, consistent with previous studies of intermediate redshift quasars. If we assume a blue bump model, most sources in our sample have derived temperatures between T(sub BB) = 10(exp 5.18) K to 10(exp 5.7) K, suggesting that the peak of this component spans a large range of energies extending from approx. (Lambda)600 A to > (Lambda)1900 A. In this case, the best fitting peak energy that matches the mid-infrared line ratios of Seyfert 1 galaxies occurs between approx. (Lambda)700-(Lambda)1000 A. Despite the fact that our results do not rule out the presence of an EUV bump, we conclude that our power-law model produces enough photons with energies > 4 Ry to generate the observed amount of mid-infrared emission in our sample of BAT AGN.

  19. Nucleosynthesis in AGB stars traced by oxygen isotopic ratios. I. Determining the stellar initial mass by means of the 17O/18O ratio

    NASA Astrophysics Data System (ADS)

    De Nutte, R.; Decin, L.; Olofsson, H.; Lombaert, R.; de Koter, A.; Karakas, A.; Milam, S.; Ramstedt, S.; Stancliffe, R. J.; Homan, W.; Van de Sande, M.

    2017-03-01

    Aims: We seek to investigate the 17O/18O ratio for a sample of AGB stars containing M-, S-, and C-type stars. These ratios are evaluated in relation to fundamental stellar evolution parameters: the stellar initial mass and pulsation period. Methods: Circumstellar 13C16O, 12C17O, and 12C18O line observations were obtained for a sample of nine stars with various single-dish long-wavelength facilities. Line intensity ratios are shown to relate directly to the surface 17O/18O abundance ratio. Results: Stellar evolution models predict the 17O/18O ratio to be a sensitive function of initial mass and to remain constant throughout the entire TP-AGB phase for stars initially less massive than 5 M⊙. This makes the measured ratio a probe of the initial stellar mass. Conclusions: Observed 17O/18O ratios are found to be well in the range predicted by stellar evolution models that do not consider convective overshooting. From this, accurate initial mass estimates are calculated for seven sources. For the remaining two sources, there are two mass solutions, although there is a larger probability that the low-mass solution is correct. Finally, we present hints at a possible separation between M/S- and C-type stars when comparing the 17O/18O ratio to the stellar pulsation period. The reduced spectra are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A71

  20. An efficient method for Agrobacterium-mediated genetic transformation and plant regeneration in cumin (Cuminum cyminum L.).

    PubMed

    Pandey, Sonika; Mishra, Avinash; Patel, Manish Kumar; Jha, Bhavanath

    2013-09-01

    Cumin is an annual herbaceous medicinally important plant having diverse applications. An efficient and reproducible method of Agrobacterium-mediated genetic transformation was herein established for the first time. A direct regeneration method without callus induction was optimised using embryos as explant material in Gamborg's B5 medium supplemented with 0.5-μM 6-benzyladenine and 2.0-μM α-naphthalene acetic acid. About 1,020 embryos (a mean of 255 embryos per batch) were used for the optimisation of transformation conditions. These conditions were an Agrobacterium cell suspension of 0.6 OD600, a co-cultivation time of 72 h, 300-μM acetosyringone and wounding of explants using a razor blade. Pre-cultured elongated embryos were treated using optimised conditions. About 720 embryos (a mean of 180 embryos per batch) were used for transformation and 95 % embryos showed transient β-glucuronidase expression after co-cultivation. Putative transformed embryos were cultured on B5 medium for shoot proliferation and 21 regenerated plants were obtained after selection and allowed to root. T0 plantlets showed β-glucuronidase expression and gene integration was confirmed via PCR amplification of 0.96 and 1.28 kb fragments of the hygromycin-phosphotransferase II and β-glucuronidase genes, respectively. In this study, a transformation efficiency of 1.5 % was demonstrated and a total of 11 transgenic plants were obtained at the hardening stage, however, only four plants acclimatised during hardening. Gene copy number was analysed by Southern blot analysis of hardened plants and single-copy gene integration was observed. This is the first successful attempt of Agrobacterium-mediated genetic transformation of cumin.

  1. Where and how long ago was water in the western North Atlantic ventilated? Maximum entropy inversions of bottle data from WOCE line A20

    NASA Astrophysics Data System (ADS)

    Holzer, Mark; Primeau, FrançOis W.; Smethie, William M.; Khatiwala, Samar

    2010-07-01

    A maximum entropy (ME) method is used to deconvolve tracer data for the joint distribution ? of locations and times since last ventilation. The deconvolutions utilize World Ocean Circulation Experiment line A20 repeat hydrography for CFC-11, potential temperature, salinity, oxygen, and phosphate, as well as Global Ocean Data Analysis Project (GLODAP) radiocarbon data, combined with surface boundary conditions derived from the atmospheric history of CFC-11 and the World Ocean Atlas 2005 and GLODAP databases. Because of the limited number of available tracers the deconvolutions are highly underdetermined, leading to large entropic uncertainties, which are quantified using the information entropy of ? relative to a prior distribution. Additional uncertainties resulting from data sparsity are estimated using a Monte Carlo approach and found to be of secondary importance. The ME deconvolutions objectively identify key water mass formation regions and quantify the local fraction of water of age τ or older last ventilated in each region. Ideal mean age and radiocarbon age are also estimated but found to have large entropic uncertainties that can be attributed to uncertainties in the partitioning of a given water parcel according to where it was last ventilated. Labrador/Irminger seawater (L water) is determined to be mostly less than ˜40 a old in the vicinity of the deep western boundary current (DWBC) at the northern end of A20 but several decades older where the DWBC recrosses the section further south, pointing to the importance of mixing via a multitude of eddy-diffusive paths. Overflow water lies primarily below L water with young waters (τ ≲ 40 a) at middepth in the northern part of A20 and waters as old as ˜600 a below ˜3500 m.

  2. Revisiting the destination ranking procedure in development of an Intervening Opportunities Model for public transit trip distribution

    NASA Astrophysics Data System (ADS)

    Nazem, Mohsen; Trépanier, Martin; Morency, Catherine

    2015-01-01

    An Enhanced Intervening Opportunities Model (EIOM) is developed for Public Transit (PT). This is a distribution supply dependent model, with single constraints on trip production for work trips during morning peak hours (6:00 a.m.-9:00 a.m.) within the Island of Montreal, Canada. Different data sets, including the 2008 Origin-Destination (OD) survey of the Greater Montreal Area, the 2006 Census of Canada, GTFS network data, along with the geographical data of the study area, are used. EIOM is a nonlinear model composed of socio-demographics, PT supply data and work location attributes. An enhanced destination ranking procedure is used to calculate the number of spatially cumulative opportunities, the basic variable of EIOM. For comparison, a Basic Intervening Opportunities Model (BIOM) is developed by using the basic destination ranking procedure. The main difference between EIOM and BIOM is in the destination ranking procedure: EIOM considers the maximization of a utility function composed of PT Level Of Service and number of opportunities at the destination, along with the OD trip duration, whereas BIOM is based on a destination ranking derived only from OD trip durations. Analysis confirmed that EIOM is more accurate than BIOM. This study presents a new tool for PT analysts, planners and policy makers to study the potential changes in PT trip patterns due to changes in socio-demographic characteristics, PT supply, and other factors. Also it opens new opportunities for the development of more accurate PT demand models with new emergent data such as smart card validations.

  3. Photoresponse and Donor Concentration of Plasma-Sprayed TiO2 and TiO2-ZnO Electrodes

    NASA Astrophysics Data System (ADS)

    Ye, F.-X.; Ohmori, A.; Li, C.-J.

    2005-12-01

    The photoelectrochemical characteristics of plasma-sprayed porous TiO2, TiO2-5%ZnO, and TiO2-10%ZnO electrodes in 0.1 N NaOH solution were studied through a three-electrode cell system. The microstructure, morphology, and composition of the electrodes were analyzed using an electron probe surface roughness analyzer (ERA-8800FE), scanning electron microscopy, and x-ray diffraction. The results indicate that the sprayed electrodes have a porous microstructure, which is affected by the plasma spray parameters and composition of the powders. The TiO2-ZnO electrodes consist of anatase TiO2, rutile TiO2, and Zn2Ti3O8 phase. The photoresponse characteristics of the plasma-sprayed electrodes are comparable to those of single-crystal TiO2, but the breakdown voltage is close to 0.5 V (versus that of a saturated calomel electrode). The short-circuit photocurrent density ( J SC) increases with a decrease of donor concentration, which was calculated according to the Gartner-Butler model. For the lowest donor concentration of a TiO2-5%ZnO electrode sprayed under an arc current of 600 A, the short-circuit J SC is approximately 0.4 mA/cm2 higher than that of the TiO2 electrodes under 30 mW/cm2 xenon light irradiation. The J SC increases linearly with light intensity.

  4. Conformations of alkali ion cationized polyethers in the gas phase: polyethylene glycol and bis[(benzo-15-crown-5)-15-ylmethyl] pimelate

    NASA Astrophysics Data System (ADS)

    Wyttenbach, Thomas; von Helden, Gert; Bowers, Michael T.

    1997-11-01

    Ion chromatography/ion mobility methods are applied to two polyether systems cationized by alkali ions. MALDI is used to generate the ions in all cases. Polyethylene glycol (PEG) 600 is cationized by Li+ and Cs+ and compared to earlier work by von Helden et al. on Na+ cationized PEG 600. A very similar distribution is obtained in the MALDI spectrum of all three metals suggesting the true PEG 600 distribution is being observed. Each cation efficiently wraps the polymer around it, however, the detailed structure of the inner coordination sphere of ether oxygens around the metal ion is metal dependent. Both Li+ and Na+ prefer a near planar five-fold coordination sphere capped on top and bottom leading to seven-fold coordination (Li+) and eight-fold coordination (Na+). The much larger Cs+ prefers 11-fold coordination if sufficient oxygen centers are available. The second system studied is the interesting dicrown bis[(benzo-15-crown-5)-15-ylmethyl] pimelate, or BBP. This tweezers-like molecule coordinates the metal ions primarily in folded, or sandwich, complexes where both rings are involved. Other structures that include metal coordination to one ring and a carbonyl oxygen (partially folded) and to one ring and no additional oxygens (unfolded) are observed in elevated temperature molecular dynamics simulations and are more important for small alkali ions (Li+) and essentially not important for large ions (Cs+). The AMBER 4.0 suite of programs is used for all calculations which in general are in excellent agreement with experiment. A quite detailed discussion of the folding dynamics of cationized BBP is presented.

  5. Electron impact excitation for He-like ions with Z = 20-42

    NASA Astrophysics Data System (ADS)

    Si, R.; Li, S.; Wang, K.; Guo, X. L.; Chen, Z. B.; Yan, J.; Chen, C. Y.; Brage, T.; Zou, Y. M.

    2017-04-01

    Aims: Spectral lines of He-like ions are among the most prominent features in X-ray spectra from a large variety of astrophysical and high-temperature fusion plasmas. A reliable plasma modeling and interpretation of the spectra require a large amount of accurate atomic data related to various physical processes. In this paper, we focus on the electron-impact excitation (EIE) process. Methods: We adopted the independent process and isolated resonances approximation using distorted waves (IPIRDW). Resonant stabilizing transitions and decays to lower-lying autoionizing levels from the resonances are included as radiative damping. To verify the applicability of the IPIRDW approximation, an independent Dirac R-matrix calculation was also performed. The two sets of results show excellent agreement. Results: We report electron impact excitation collision strengths for transitions among the lowest 49 levels of the 1snl(n ≤ 5,l ≤ (n-1)) configurations in He-like ions with 20 ≤ Z ≤ 42. The line ratios R and G are calculated for Fe XXV and Kr XXXV. Conclusions: Compared to previous theoretical calculations, our IPIRDW calculation treats resonance excitation and radiative damping effects more comprehensively, and the resulting line emission cross sections show good agreement with the experimental observations. Our results should facilitate the modeling and diagnostics of various astrophysical and laboratory plasmas. Full Table 1 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A85

  6. Toxicity Data to Determine Refrigerant Concentration Limits

    SciTech Connect

    Calm, James M.

    2000-09-30

    This report reviews toxicity data, identifies sources for them, and presents resulting exposure limits for refrigerants for consideration by qualified parties in developing safety guides, standards, codes, and regulations. It outlines a method to calculate an acute toxicity exposure limit (ATEL) and from it a recommended refrigerant concentration limit (RCL) for emergency exposures. The report focuses on acute toxicity with particular attention to lethality, cardiac sensitization, anesthetic and central nervous system effects, and other escape-impairing effects. It addresses R-11, R-12, R-22, R-23, R-113, R-114, R-116, R-123, R-124, R-125, R-134, R-134a, R-E134, R-141b, R-142b, R-143a, R-152a, R-218, R-227ea, R-236fa, R-245ca, R-245fa, R-290, R-500, R-502, R-600a, R-717, and R-744. It summarizes additional data for R-14, R-115, R-170 (ethane), R-C318, R-600 (n-butane), and R-1270 (propylene) to enable calculation of limits for blends incorporating them. The report summarizes the data a nd related safety information, including classifications and flammability data. It also presents a series of tables with proposed ATEL and RCL concentrations-in dimensionless form and the latter also in both metric (SI) and inch-pound (IP) units of measure-for both the cited refrigerants and 66 zerotropic and azeotropic blends. They include common refrigerants, such as R-404A, R-407C, R-410A, and R-507A, as well as others in commercial or developmental status. Appendices provide profiles for the cited single-compound refrigerants and for R-500 and R-502 as well as narrative toxicity summaries for common refrigerants. The report includes an extensive set of references.

  7. Hydrogen in diffuse molecular clouds in the Milky Way. Atomic column densities and molecular fraction along prominent lines of sight

    NASA Astrophysics Data System (ADS)

    Winkel, B.; Wiesemeyer, H.; Menten, K. M.; Sato, M.; Brunthaler, A.; Wyrowski, F.; Neufeld, D.; Gerin, M.; Indriolo, N.

    2017-03-01

    Context. Recent submillimeter and far-infrared wavelength observations of absorption in the rotational ground-state lines of various simple molecules against distant Galactic continuum sources have opened the possibility of studying the chemistry of diffuse molecular clouds throughout the Milky Way. In order to calculate abundances, the column densities of molecular and atomic hydrogen, H i, must be known. Aims: We aim at determining the atomic hydrogen column densities for diffuse clouds located on the sight lines toward a sample of prominent high-mass star-forming regions that were intensely studied with the HIFI instrument onboard Herschel. Methods: Based on Jansky Very Large Array data, we employ the 21 cm H i absorption-line technique to construct profiles of the H i opacity versus radial velocity toward our target sources. These profiles are combined with lower resolution archival data of extended H i emission to calculate the H i column densities of the individual clouds along the sight lines. We employ Bayesian inference to estimate the uncertainties of the derived quantities. Results: Our study delivers reliable estimates of the atomic hydrogen column density for a large number of diffuse molecular clouds at various Galactocentric distances. Together with column densities of molecular hydrogen derived from its surrogates observed with HIFI, the measurements can be used to characterize the clouds and investigate the dependence of their chemistry on the molecular fraction, for example. The data sets are available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A2

  8. Investigating merging galaxies by using Pan-STARRS images

    NASA Astrophysics Data System (ADS)

    Lin, Yi-Fan; Yu, Po-Chieh; Huang, Jen-Chao; Hwang, Chorng-Yuan; Chen, Wen-Ping; Kaiser, Nick; Metcalfe, Nigel; Waters, Christopher

    2017-03-01

    Aims: We studied the r'-, z'-, and y'-band images of merging galaxies from the observations of the Panoramic Survey Telescope & Rapid Response System (Pan-STARRS). The merging galaxies were selected from our merging catalog that was created by checking the images of the Red-Sequence Cluster Survey 2 from the observations of the Canada France Hawaii Telescope. Methods: By using the homomorphic-aperture, we determined the photometric results of these merging systems. To obtain accurate photometry, we calibrated the Pan-STARRS r'-, z'-, and y'-band data to match the results of Sloan Digital Sky Survey Data Release 9. We also investigated the stellar masses of the merging galaxies by comparing the Wide-field Infrared Survey Explorer 3.4 μm emission with the calibrated y'-band data. Results: We present a catalog of the r'-, z'-, and y'-band photometric results for 4698 merging galaxies. For extended sources, our results suggest that the homomorphic-aperture method can obtain more reasonable results than the Desktop Virtual Observatory photometry. We derived new relations between the Pan-STARRS y'-band luminosities and the stellar masses of the merging galaxies. Our results show that the stellar masses of the merging galaxies range from 108 to 1013M⊙; some of the dry mergers could be as massive as 1013M⊙. The catalog is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A28

  9. Direct and large-eddy simulations of the stable atmospheric boundary layer: the effect of unsteadiness and surface variability

    NASA Astrophysics Data System (ADS)

    Shah, S.; Bou-Zeid, E.

    2013-12-01

    Understanding and parameterizing turbulent fluxes in statically-stable atmospheric boundary layers (SABLs), where buoyant forces destroy turbulent kinetic energy, remains a challenging yet very important problem in geophysical fluid dynamics. The complexities of these flows are further exacerbated by the increased sensitivity to unsteadiness and surface variability. To address the role of these exacerbating factors, direct numerical simulations and large eddy simulations are performed. Under the highest stabilities, global intermittency (the almost compete decay of turbulence and then its regeneration) is observed. The intermittent bursts are important to study under these conditions since they become the main agent of vertical transport in the SABL. Under more moderate stabilities, continuous turbulence is maintained, but it is significantly damped compared to neutral flows. This reduction of the TKE under stable conditions is very well known; however, in this study, we show that it is mainly triggered by reduced mechanical production associated with reduced transport of Reynolds stresses from aloft toward the surface, rather than by direct destruction of TKE by buoyancy. Variability of surface temperature is shown to result in excepted flow patterns: TKE is potentially higher under the more stable patches due to advection, and the subsidence and lofting of air over the different patches can counteract the effect of spatial TKE variability on the vertical fluxes. Re_f = 600. (a) Surface Richardson number (R_{i0;t}) versus non-dimensional time (tf) for different stabilities. (b) Non-dimensional volume integrated turbulent kinetic energy per unit area (E). (c) Friction velocity (u_*) and its variation with time and stability. (d) Variation of the angle (Beta) between the geostrophic wind direction and the surface shear stress direction with time and stability. Colormap of the TKE from a heterogeneous surface temperature LES, showing the effect of advection.

  10. An IGBT Driven Slotted Beam Pipe Kicker for SPEAR III Injection

    SciTech Connect

    Cassel, Richard

    2002-08-21

    The SPEAR III injection kicker system is composed of three kicker magnets, K1, K2, and K3. These magnets, along with the power modulators to drive them constitute an injection system which will be used to deflect an incoming electron beam with an energy of 3.3 GeV by an angle of 2.5 mrad for K1 and K3, and 1 mrad for K2. The pulse shape of the magnetic field in the three magnets must be matched in order to preserve a closed orbit. The pulse duration is required to be less than 780 ns, with rise and fall times of less than 375 ns, and a pulse repetition frequency of 10 Hz. The aperture of all three magnets is 60 x 34 mm in an 8 inch vacuum vessel. The magnetic length is 1.2 m for K1 and K3, and 0.6 m for K2 [1]. The magnet design employs a slotted beam pipe which is shorted at one end. A solid state IGBT based, induction type of modulator drives the magnets. Modulators for K1 and K3 consist of eight 4.5 kV, 600 A IGBTs, and eight Finemet magnet cores with four 22.5 Ohm output cables to drive 2381 A into the magnets. The modulator for K2 uses four IGBTs and cores, and 8 output cables to produce a 2619 A pulse. Cables of length greater than one half the pulse width must be used in order to avoid reflections from the shorted magnet. The design charge voltage for the modulators is 20 kV for K1 and K3. This paper describes the magnet and modulator design, as and presents test data from a prototype system.

  11. The interplay between mood and language comprehension: evidence from P600 to semantic reversal anomalies.

    PubMed

    Vissers, Constance Th W M; Chwilla, Uli G; Egger, Jos I M; Chwilla, Dorothee J

    2013-05-01

    Little is known about the relationship between language and emotion. Vissers et al. (2010) investigated the effects of mood on the processing of syntactic violations, as indexed by P600. An interaction was observed between mood and syntactic correctness for which three explanations were offered: one in terms of syntactic processing, one in terms of heuristic processing, and one in terms of more general factors like attention and/or motivation. In this experiment, we further determined the locus of the effects of emotional state on language comprehension by investigating the effects of mood on the processing of semantic reversal anomalies (e.g., "the cat that fled from the mice"), in which heuristics play a key role. The main findings were as follows. The mood induction was effective: participants were happier after watching happy film clips and sadder after watching sad film clips compared to baseline. For P600, a mood by semantic plausibility interaction was obtained reflecting a broadly distributed P600 effect for the happy mood vs. absence of a P600 for the sad mood condition. Correlation analyses confirmed that changes in P600 in happy mood were accompanied by changes in emotional state. Given that semantic reversal anomalies are syntactically unambiguous, the P600 modulation by mood cannot be explained by syntactic factors. The semantic plausibility by mood interaction can be accounted for in terms of (1) heuristic processing (stronger reliance on a good enough representation of the input in happy mood than sad mood), and/or (2) more general factors like attention (e.g., more attention to semantic reversals in happy mood than sad mood).

  12. Detection of lithium in nearby young late-M dwarfs

    NASA Astrophysics Data System (ADS)

    Phan-Bao, N.; Bessell, M. S.; Nguyen-Thanh, D.; Martín, E. L.; Ho, P. T. P.; Lee, C. F.; Parsons, H.

    2017-03-01

    Context. Late M-type dwarfs in the solar neighborhood include a mixture of very low-mass stars and brown dwarfs that is difficult to disentangle due to the lack of constraints on their age, such as trigonometric parallax, lithium detection, and space velocity. Aims: We search for young brown dwarf candidates among a sample of 28 nearby late-M dwarfs with spectral types between M5.0 and M9.0, and we also search for debris disks around three of them. Methods: Based on theoretical models, we used the color I-J, the J-band absolute magnitude, and the detection of the Li I 6708 Å doublet line as a strong constraint to estimate masses and ages of our targets. For the search of debris disks, we observed three targets at submillimeter wavelength of 850 μm. Results: We report here the first clear detections of lithium absorption in four targets and a marginal detection in one target. Our mass estimates indicate that two of them are young brown dwarfs, two are young brown dwarf candidates, and one is a young very low-mass star. The closest young field brown dwarf in our sample at only 15 pc is an excellent benchmark for further studying physical properties of brown dwarfs in the range 100-150 Myr. We did not detect any debris disks around three late-M dwarfs, and we estimated upper limits to the dust mass of debris disks around them. The reduced spectra (FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A19

  13. A statistical study of evening sector arcs and electrojets

    NASA Astrophysics Data System (ADS)

    Kauristie, K.; Syrjäsuo, M. T.; Amm, O.; Viljanen, A.; Pulkkinen, T. I.; Opgenoorth, H. J.

    2001-01-01

    We present results of a statistical study of evening sector auroral arcs associated with electrojets. The study (including ˜ 1000 all-sky camera (ASC) frames) is based on data of the MIRACLE instrument network. An automatic search engine is used to define the arc periods from ASC data and the recordings of the IMAGE magnetometer network are used to estimate the strength and location of the equivalent electrojet currents. The maximum current densities and intensities of the equivalent electrojets vary in the ranges 200-600 A/km and 200-400 kA, respectively. In 85 % of cases with single arcs the current system is of a convection reversal type (an eastward electrojet equatorward of a westward electrojet). Usually the arc is within 1° distance from the latitude of maximum eastward current density which is ≤4° south from the transition region between the westward and eastward electrojets. Most of such events were observed in the dusk sector, not in the premidnight-sector, which is generally considered as the typical Harang discontinuity (HD) region of convection reversal type currents. Furthermore, the poleward boundary of the westward current is very often poleward of the northernmost IMAGE station (CGM lat. ˜76), which may mean that the westward currents are not real horizontal currents but equivalent currents due to field aligned R1 currents. This implies that a stable arc often resides a few degrees equatorward to the evening shell potential minimum. We discuss the implications of these findings from the viewpoint of previous HD-studies.

  14. Extreme events in the sedimentary record of maar Lake Pavin: Implications for natural hazards assessment in the French Massif Central

    NASA Astrophysics Data System (ADS)

    Chassiot, Léo; Chapron, Emmanuel; Di Giovanni, Christian; Albéric, Patrick; Lajeunesse, Patrick; Lehours, Anne-Catherine; Meybeck, Michel

    2016-06-01

    A set of sedimentary cores, high resolution swath bathymetry and subbottom profiler data provides new insights on sedimentary processes in meromictic maar Lake Pavin, France. Three sedimentary environments (i.e., littoral, plateau and basin) have been identified in the lake from sediment composition using bulk organic geochemistry and the analysis of hydroacoustic images. Various forms of rapidly deposited layers (RDLs) have been identified and radiocarbon dated. An up to date stratigraphy of sedimentary events matching coeval RDLs across the lake is presented and illustrates a wide range of natural hazards linked to Lake Pavin during the last 2000 years. In AD 600, a sudden lake outburst triggered a slump deposit along with a 9 m lake-level drop that drove shifts in sedimentary organic matter composition. Outside the lake, outburst flood deposits have been described downstream and provide sedimentary evidence for this event. The lake-level drop also favored the generation of gravity reworking processes, as shown by (1) a regional earthquake-triggered large slope failure on the plateau connected to a mass-wasting deposit in the basin dated to AD 1300, and (2) a succession of turbidites in AD 1825 and AD 1860 contemporaneous to two historic earthquakes, suggesting that this lake is sensitive to earthquakes with a minimum epicentral intensity of V. Finally, past observations of lake water color changes in AD 1783 and AD 1936, similar to reports in other meromictic lakes, match iron-rich deposits identified in maar lake sediments and suggest that Lake Pavin could have undergone limnic eruptions.

  15. Cultivation and Characterization of Cynara Cardunculus for Solid Biofuels Production in the Mediterranean Region

    PubMed Central

    Grammelis, Panagiotis; Malliopoulou, Anastasia; Basinas, Panagiotis; Danalatos, Nicholas G.

    2008-01-01

    Technical specifications of solid biofuels are continuously improved towards the development and promotion of their market. Efforts in the Greek market are limited, mainly due to the climate particularity of the region, which hinders the growth of suitable biofuels. Taking also into account the increased oil prices and the high inputs required to grow most annual crops in Greece, cardoon (Cynara cardunculus L.) is now considered the most important and promising sources for solid biofuel production in Greece in the immediate future. The reason is that cardoon is a perennial crop of Mediterranean origin, well adapted to the xerothermic conditions of southern Europe, which can be utilized particularly for solid biofuel production. This is due to its minimum production cost, as this perennial weed may perform high biomass productivity on most soils with modest or without any inputs of irrigation and agrochemicals. Within this framework, the present research work is focused on the planning and analysis of different land use scenarios involving this specific energy crop and the combustion behaviour characterization for the solid products. Such land use scenarios are based on quantitative estimates of the crop'sproduction potential under specific soil-climatic conditions as well as the inputs required for its realization in comparison to existing conventional crops. Concerning its decomposition behaviour, devolatilisation and char combustion tests were performed in a non-isothermal thermogravimetric analyser (TA Q600). A kinetic analysis was applied and accrued results were compared with data already available for other lignocellulosic materials. The thermogravimetric analysis showed that the decomposition process of cardoon follows the degradation of other lignocellulosic fuels, meeting high burnout rates. This research work concludes that Cynara cardunculus, under certain circumstances, can be used as a solid biofuel of acceptable quality. PMID:19325802

  16. Preoperative N Staging of Gastric Cancer by Stomach Protocol Computed Tomography

    PubMed Central

    Kim, Se Hoon; Kim, Jeong Jae; Lee, Jeong Sub; Kim, Seung Hyoung; Kim, Bong Soo; Maeng, Young Hee; Hyun, Chang Lim; Kim, Min Jeong

    2013-01-01

    Purpose Clinical stage of gastric cancer is currently assessed by computed tomography. Accurate clinical staging is important for the tailoring of therapy. This study evaluated the accuracy of clinical N staging using stomach protocol computed tomography. Materials and Methods Between March 2004 and November 2012, 171 patients with gastric cancer underwent preoperative stomach protocol computed tomography (Jeju National University Hospital; Jeju, Korea). Their demographic and clinical characteristics were reviewed retrospectively. Two radiologists evaluated cN staging using axial and coronal computed tomography images, and cN stage was matched with pathologic results. The diagnostic accuracy of stomach protocol computed tomography for clinical N staging and clinical characteristics associated with diagnostic accuracy were evaluated. Results The overall accuracy of stomach protocol computed tomography for cN staging was 63.2%. Computed tomography images of slice thickness 3.0 mm had a sensitivity of 60.0%; a specificity of 89.6%; an accuracy of 78.4%; and a positive predictive value of 78.0% in detecting lymph node metastases. Underestimation of cN stage was associated with larger tumor size (P<0.001), undifferentiated type (P=0.003), diffuse type (P=0.020), more advanced pathologic stage (P<0.001), and larger numbers of harvested and metastatic lymph nodes (P<0.001 each). Tumor differentiation was an independent factor affecting underestimation by computed tomography (P=0.045). Conclusions Computed tomography with a size criterion of 8 mm is highly specific but relatively insensitive in detecting nodal metastases. Physicians should keep in mind that computed tomography may not be an appropriate tool to detect nodal metastases for choosing appropriate treatment. PMID:24156034

  17. MEASURING TINY MASS ACCRETION RATES ONTO YOUNG BROWN DWARFS

    SciTech Connect

    Herczeg, Gregory J.; Cruz, Kelle L.; Hillenbrand, Lynne A.

    2009-05-10

    We present low-resolution Keck I/LRIS spectra spanning from 3200 to 9000 A of nine young brown dwarfs and three low-mass stars in the TW Hya Association and in Upper Sco. The optical spectral types of the brown dwarfs range from M5.5 to M8.75, though two have near-IR spectral types of early L dwarfs. We report new accretion rates derived from excess Balmer continuum emission for the low-mass stars TW Hya and Hen 3-600A and the brown dwarfs 2MASS J12073347-3932540, UScoCTIO 128, SSSPM J1102-3431, USco J160606.29-233513.3, DENIS-P J160603.9-205644, and Oph J162225-240515B, and upper limits on accretion for the low-mass star Hen 3-600B and the brown dwarfs UScoCTIO 112, Oph J162225-240515A, and USco J160723.82-221102.0. For the six brown dwarfs in our sample that are faintest at short wavelengths, the accretion luminosity or upper limit is measurable only when the image is binned over large wavelength intervals. This method extends our sensitivity to accretion rate down to {approx}10{sup -13} M{sub sun}yr{sup -1} for brown dwarfs. Since the ability to measure an accretion rate from excess Balmer continuum emission depends on the contrast between excess continuum emission and the underlying photosphere, for objects with earlier spectral types the upper limit on accretion rate is much higher. Absolute uncertainties in our accretion rate measurements of {approx}3-5 include uncertainty in accretion models, brown dwarf masses, and distance. The accretion rate of 2 x 10{sup -12} M {sub sun} yr{sup -1} onto 2MASS J12073347-3932540 is within 15% of two previous measurements, despite large changes in the H{alpha} flux.

  18. Ecological aspects of phlebotomine fauna (Diptera, Psychodidae) of Serra da Cantareira, Greater São Paulo Metropolitan region, state of São Paulo, Brazil.

    PubMed

    Moschin, José Carlos; Ovallos, Fredy Galvis; Sei, Iole Arumi; Galati, Eunice A B

    2013-03-01

    Human cases of American cutaneous leishmaniasis (ACL) have been recorded in Serra da Cantareira, in the Greater São Paulo Metropolitan Region, where two conservation units are situated, the Parque Estadual da Cantareira and the Parque Estadual Alberto Löfgren. The present study aimed to identify the sandfly fauna and some of its ecological aspects in these two parks and their surrounding area to investigate Leishmania sp. vectors. The captures were undertaken monthly from January to December 2009, from 6:00 p.m. to 6:00 a.m., with automatic light traps installed in forests and peridomicile areas and with modified black/white Shannon traps in the peridomicile. A total of 12 species and 5,436 sandflies were captured: with automatic light traps (141), Shannon traps (5,219) and attempting to bite the researchers while they were conducting the collection in Shannon traps (76). Pintomyia fischeri and Migonemyia migonei were the most abundant species. Pi. fischeri predominated in all three kinds of captures (49%, 88.8% and 65.8%, respectively). Mg. migonei was the second most prevalent in Shannon traps (10.0%) and attempting to bite the researchers (22.4%). Pi. fischeri females were significantly more attracted to black and those of Mg. migonei to white Shannon traps. A positive and significant correlation was observed between the numbers of Pi. fischeri and the mean of minimum relative humidity values on the fifteen days prior to capture, while there was a negative and significant correlation between the relative humidity on the capture day and the two most abundant species. The anthropophilia and high frequencies of Pi. fischeri and Mg. migonei suggest that both species may be transmitting ACL agents in this region.

  19. Numerical simulation on level fluctuation in bloom casting mold with electromagnetic stirring

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Ni, H. W.; Li, Y.; Zhao, Z. F.

    2016-03-01

    Based on a 380mm × 280mm bloom caster mold, the level fluctuation of steel-slag interface in the mold was simulated by the VOF model of commercial software Fluent. The effects of current intensity and frequency of EMS (electromagnetic stirring) on the level fluctuation in the mold were studied. The results show that whether or not with EMS, the maximum level fluctuation site of the mold occurs in the vicinity of the submerged entry nozzle. Compared with casting without EMS, molten steel flows horizontally rotatably under the action of the electromagnetic force by electromagnetic stirring, so the impact depth of molten steel decreases, then the level fluctuation slightly reduces, and the maximum level fluctuation value in the wide direction and the narrow direction of the mold, reduce from 4.24mm and 4.14mm to 4.04mm and 3.73mm respectively. With increasing intensity and frequency of current, the mold level fluctuation rises and the distribution uniformity of the level fluctuating amplitude worsens. The maximum level fluctuation enlarges by 0.18mm with raising the current intensity from 450A to 550A, but it enlarges by 0.79mm with 600A current intensity. The maximum level fluctuation enlarges by 0.15mm with raising the current frequency from 1.5Hz to 2.0Hz, but it quickly enlarges by 0.78mm with 2.5Hz current frequency. When the current strength and frequency are not more than 550A and 2.0Hz, level fluctuations are 4.00mm or less, which can meet requirements for controlling the bloom surface quality.

  20. Limb and gravity-darkening coefficients for the TESS satellite at several metallicities, surface gravities, and microturbulent velocities

    NASA Astrophysics Data System (ADS)

    Claret, A.

    2017-03-01

    Aims: We present new gravity and limb-darkening coefficients for a wide range of effective temperatures, gravities, metallicities, and microturbulent velocities. These coefficients can be used in many different fields of stellar physics as synthetic light curves of eclipsing binaries and planetary transits, stellar diameters, line profiles in rotating stars, and others. Methods: The limb-darkening coefficients were computed specifically for the photometric system of the space mission tess and were performed by adopting the least-square method. In addition, the linear and bi-parametric coefficients, by adopting the flux conservation method, are also available. On the other hand, to take into account the effects of tidal and rotational distortions, we computed the passband gravity-darkening coefficients y(λ) using a general differential equation in which we consider the effects of convection and of the partial derivative (∂lnI(λ) /∂lng)Teff. Results: To generate the limb-darkening coefficients we adopt two stellar atmosphere models: atlas (plane-parallel) and phoenix (spherical, quasi-spherical, and r-method). The specific intensity distribution was fitted using five approaches: linear, quadratic, square root, logarithmic, and a more general one with four terms. These grids cover together 19 metallicities ranging from 10-5 up to 10+1 solar abundances, 0 ≤ log g ≤ 6.0 and 1500 K ≤Teff ≤ 50 000 K. The calculations of the gravity-darkening coefficients were performed for all plane-parallel ATLAS models. Tables 2-29 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A30

  1. Effect of night time-intervals, height of traps and lunar phases on sand fly collection in a highly endemic area for canine leishmaniasis.

    PubMed

    Gaglio, Gabriella; Brianti, Emanuele; Napoli, Ettore; Falsone, Luigi; Dantas-Torres, Filipe; Tarallo, Viviana D; Otranto, Domenico; Giannetto, Salvatore

    2014-05-01

    The activity of phlebotomine sand flies was monitored in a sub-urban area of Sicily in order to acquire data on seasonality and to elucidate the effect of the night time-intervals, height of traps from ground and lunar phases on the abundance of the capture. The study was conducted in the farm of the University of Messina (Italy). Light traps were placed as in the following: biweekly, from dusk to dawn, and from May to November; for three consecutive nights from 18:00 to 6:00, with the net bag being changed every 2h; for 30 days, at different heights from 18:00 to 6:00. A total of five species (i.e., Phlebotomus perniciosus, Phlebotomus neglectus, Phlebotomus sergenti, Phlebotomus perfiliewi, and Sergentomyia minuta), three of which are proven vectors of Leishmania infantum, were captured. The most abundant species was P. perniciosus (73.3%) followed by S. minuta (23.3%). The highest number of phlebotomine sand flies was collected in August and September with a peak of collection recorded in the evening (i.e., from 20:01 to 22.00). The number of phlebotomine sand flies collected at 50cm above the ground was significantly higher (P=0.041) than that captured at 150cm. Results of this study shed light on the ecology of main phlebotomine species in the Mediterranean area, and on the influence of some factors, such as time and height of traps, on the light trap capture efficiency.

  2. A refined mass distribution of the cluster MACS J0416.1-2403 from a new large set of spectroscopic multiply lensed sources

    NASA Astrophysics Data System (ADS)

    Caminha, G. B.; Grillo, C.; Rosati, P.; Balestra, I.; Mercurio, A.; Vanzella, E.; Biviano, A.; Caputi, K. I.; Delgado-Correal, C.; Karman, W.; Lombardi, M.; Meneghetti, M.; Sartoris, B.; Tozzi, P.

    2017-04-01

    We report the spectroscopic confirmation of 22 new multiply lensed sources behind the Hubble Frontier Field (HFF) galaxy cluster MACS J0416.1-2403 (MACS 0416), using archival data from the Multi Unit Spectroscopic Explorer (MUSE) on the VLT. Combining with previous spectroscopic measurements of 15 other multiply imaged sources, we have obtained a sample of 102 secure multiple images with measured redshifts, the largest to date in a single strong lensing system. The newly confirmed sources are largely low-luminosity Lyman-α emitters with redshift in the range [ 3.08-6.15 ]. With such a large number of secure constraints, and a significantly improved sample of galaxy members in the cluster core, we have improved our previous strong lensing model and obtained a robust determination of the projected total mass distribution of MACS 0416. We find evidence of three cored dark-matter halos, adding to the known complexity of this merging system. The total mass density profile, as well as the sub-halo population, are found to be in good agreement with previous works. We update and make public the redshift catalog of MACS 0416 from our previous spectroscopic campaign with the new MUSE redshifts. We also release lensing maps (convergence, shear, magnification) in the standard HFF format. Source catalog (full Table A.2) is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A90

  3. Parallel molecular dynamics simulations of pressure-induced structural transformations in cadmium selenide nanocrystals

    NASA Astrophysics Data System (ADS)

    Lee, Nicholas Jabari Ouma

    Parallel molecular dynamics (MD) simulations are performed to investigate pressure-induced solid-to-solid structural phase transformations in cadmium selenide (CdSe) nanorods. The effects of the size and shape of nanorods on different aspects of structural phase transformations are studied. Simulations are based on interatomic potentials validated extensively by experiments. Simulations range from 105 to 106 atoms. These simulations are enabled by highly scalable algorithms executed on massively parallel Beowulf computing architectures. Pressure-induced structural transformations are studied using a hydrostatic pressure medium simulated by atoms interacting via Lennard-Jones potential. Four single-crystal CdSe nanorods, each 44A in diameter but varying in length, in the range between 44A and 600A, are studied independently in two sets of simulations. The first simulation is the downstroke simulation, where each rod is embedded in the pressure medium and subjected to increasing pressure during which it undergoes a forward transformation from a 4-fold coordinated wurtzite (WZ) crystal structure to a 6-fold coordinated rocksalt (RS) crystal structure. In the second so-called upstroke simulation, the pressure on the rods is decreased and a reverse transformation from 6-fold RS to a 4-fold coordinated phase is observed. The transformation pressure in the forward transformation depends on the nanorod size, with longer rods transforming at lower pressures close to the bulk transformation pressure. Spatially-resolved structural analyses, including pair-distributions, atomic-coordinations and bond-angle distributions, indicate nucleation begins at the surface of nanorods and spreads inward. The transformation results in a single RS domain, in agreement with experiments. The microscopic mechanism for transformation is observed to be the same as for bulk CdSe. A nanorod size dependency is also found in reverse structural transformations, with longer nanorods transforming more

  4. Movements of wolves at the northern extreme of the species' range, including during four months of darkness

    USGS Publications Warehouse

    Mech, L. David; Cluff, H. Dean

    2011-01-01

    Information about wolf (Canis lupus) movements anywhere near the northern extreme of the species' range in the High Arctic (>75°N latitude) are lacking. There, wolves prey primarily on muskoxen (Ovibos moschatus) and must survive 4 months of 24 hr/day winter darkness and temperatures reaching -53 C. The extent to which wolves remain active and prey on muskoxen during the dark period are unknown, for the closest area where information is available about winter wolf movements is >2,250 km south. We studied a pack of ≥20 wolves on Ellesmere Island, Nunavut, Canada (80°N latitude) from July 2009 through mid-April 2010 by collaring a lead wolf with a Global Positioning System (GPS)/Argos radio collar. The collar recorded the wolf's precise locations at 6:00 a.m. and 6:00 p.m. daily and transmitted the locations by satellite to our email. Straight-line distances between consecutive 12-hr locations varied between 0 and 76 km. Mean (SE) linear distance between consecutive locations (n = 554) was 11 (0.5) km. Total minimum distance traveled was 5,979 km, and total area covered was 6,640 km2, the largest wolf range reported. The wolf and presumably his pack once made a 263-km (straight-line distance) foray to the southeast during 19–28 January 2010, returning 29 January to 1 February at an average of 41 km/day straight-line distances between 12-hr locations. This study produced the first detailed movement information about any large mammal in the High Arctic, and the average movements during the dark period did not differ from those afterwards. Wolf movements during the dark period in the highest latitudes match those of the other seasons and generally those of wolves in lower latitudes, and, at least with the gross movements measurable by our methods, the 4-month period without direct sunlight produced little change in movements.

  5. A refined analysis of the low-mass eclipsing binary system T-Cyg1-12664

    NASA Astrophysics Data System (ADS)

    Iglesias-Marzoa, Ramón; López-Morales, Mercedes; Arévalo, María J.; Coughlin, Jeffrey L.; Lázaro, Carlos

    2017-03-01

    -3 and 10 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A55

  6. Magnetic activity in the HARPS M dwarf sample. The rotation-activity relationship for very low-mass stars through

    NASA Astrophysics Data System (ADS)

    Astudillo-Defru, N.; Delfosse, X.; Bonfils, X.; Forveille, T.; Lovis, C.; Rameau, J.

    2017-03-01

    activity correlates with its mean level and stars with higher indexes show larger variability, as previously observed for earlier spectral types. Full Table A.2 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A13

  7. Nighttime aqueous-phase secondary organic aerosols in Los Angeles and its implication for fine particulate matter composition and oxidative potential

    NASA Astrophysics Data System (ADS)

    Saffari, Arian; Hasheminassab, Sina; Shafer, Martin M.; Schauer, James J.; Chatila, Talal A.; Sioutas, Constantinos

    2016-05-01

    Recent investigations suggest that aqueous phase oxidation of hydrophilic organic compounds can be a significant source of secondary organic aerosols (SOA) in the atmosphere. Here we investigate the possibility of nighttime aqueous phase formation of SOA in Los Angeles during winter, through examination of trends in fine particulate matter (PM2.5) carbonaceous content during two contrasting seasons. Distinctive winter and summer trends were observed for the diurnal variation of organic carbon (OC) and secondary organic carbon (SOC), with elevated levels during the nighttime in winter, suggesting an enhanced formation of SOA during that period. The nighttime ratio of SOC to OC was positively associated with the relative humidity (RH) at high RH levels (above 70%), which is when the liquid water content of the ambient aerosol would be high and could facilitate dissolution of hydrophilic primary organic compounds into the aqueous phase. Time-integrated collection and analysis of wintertime particles at three time periods of the day (morning, 6:00 a.m.-9:00 a.m.; afternoon, 11:00 a.m.-3:00 p.m.; night, 8:00 p.m.-4:00 a.m.) revealed higher levels of water soluble organic carbon (WSOC) and organic acids during the night and afternoon periods compared to the morning period, indicating that the SOA formation in winter continues throughout the nighttime. Furthermore, diurnal trends in concentrations of semi-volatile organic compounds (SVOCs) from primary emissions showed that partitioning of SVOCs from the gas to the particle phase due to the decreased nighttime temperatures cannot explain the substantial OC and SOC increase at night. The oxidative potential of the collected particles (quantified using a biological macrophage-based reactive oxygen species assay, in addition to the dithiothreitol assay) was comparable during afternoon and nighttime periods, but higher (by at least ∼30%) compared to the morning period, suggesting that SOA formation processes possibly enhance the toxicity of the ambient particles compared to mobile-source dominated primary emissions in the Los Angeles area.

  8. Characterization of Angiotensin-(1-7) effects on the cardiovascular system in an experimental model of type-1 diabetes.

    PubMed

    Yousif, Mariam H M; Dhaunsi, Gursev S; Makki, Batoul M; Qabazard, Bedour A; Akhtar, Saghir; Benter, Ibrahim F

    2012-09-01

    Although exogenous administration of Angiotensin-(1-7) [Ang-(1-7)] can prevent development of diabetes induced end-organ damage, little is known about the role of endogenous Ang-(1-7) in diabetes and requires further characterization. Here, we studied the effects of chronically inhibiting endogenous Ang-(1-7) formation with DX600, a selective angiotensin converting enzyme-2 (ACE2) inhibitor, on renal and cardiac NADPH oxidase (NOX) activity, vascular reactivity and cardiac function in a model of Type-1 diabetes. The contribution of endogenous Ang-(1-7) to the protective effects of Losartan and Captopril and that of prostaglandins to the cardiovascular effects of exogenous Ang-(1-7) were also examined. Cardiac and renal NOX activity, vascular reactivity to endothelin-1 (ET-1) and cardiac recovery from ischemia/reperfusion (I/R) injury were evaluated in streptozotocin-treated rats. Chronic treatment with DX600 exacerbated diabetes-induced increase in cardiac and renal NOX activity. Diabetes-induced abnormal vascular reactivity to ET-1 and cardiac dysfunction were improved by treatment with Ang-(1-7) and worsened by treatment with DX600 or A779, a Mas receptor antagonist. Ang-(1-7)-mediated improvement in cardiac recovery or vascular reactivity was attenuated by Indomethacin. Captopril and Losartan-induced improvement in cardiovascular function was attenuated when these drugs were co-administered with A779. Ang-(1-7)-mediated decrease in renal NOX activity was prevented by indomethacin. Losartan also decreased renal NOX activity that could be attenuated with A779 co-treatment. In conclusion, endogenous Ang-(1-7) inhibits diabetes-induced cardiac/renal NOX activity and end-organ damage, and mediates the actions of Captopril and Losartan. Further, prostaglandins are important intermediaries in the beneficial effects of Ang-(1-7) in diabetes. Combining either Losartan or Captopril with Ang-(1-7) had additional beneficial effects in preventing diabetes-induced cardiac

  9. Lactones in 193 nm resists: What do they do?

    NASA Astrophysics Data System (ADS)

    Ito, Hiroshi; Truong, Hoa D.; Brock, Phil J.

    2008-03-01

    that the deprotection fragment from the former does not interfere with the development but that from the latter does. When the NLM concentration is increased to 75 %, highly exposed P(ECOMA-NLM) resist dissolves slowly at ca. 600 A/sec and swells significantly, indicating that NLM can be a dissolution inhibitor and swelling enhancer when its concentration is high. Low activation energy protecting groups such as ethylcyclooctyl allows imaging at temperatures as low as 60 °C. However, the temperature dependence of the dose to clear is very large and the chemical contrast is quite small in the low temperature range. Thus, for PEB temperature stability and contrast enhancement, baking 20-30 °C above the lowest practical temperature is recommended.

  10. Development of a practicable non-contact bedside autonomic activation monitoring system using microwave radars and its clinical application in elderly people.

    PubMed

    Matsui, Takemi; Yoshida, Yuto; Kagawa, Masayuki; Kubota, Masayuki; Kurita, Akira

    2013-06-01

    We developed a practicable, non-contact, autonomic activation monitoring system using microwave radars without imposing any stress on monitored individuals. Recently, the rapid increase in the aging population has raised concerns in developed countries. Thus, hospitals and care facilities will need to perform long-term health monitoring of elderly patients. The system allows monitoring of geriatric autonomic dysfunctions caused by chronic diseases, such as diabetes or myocardial infarction (MI), while measuring vital signs in non-contact way. The system measures heart rate variability (HRV) of elderly people in bed using dual, 24-GHz, compact microwave radars attached beneath the bed mattress. HRV parameters (LF, HF, and LF/HF) were determined from the cardiac peak-to-peak intervals, which were detected by radars using the maximum entropy method. We tested the system on 15 elderly people with and without diabetes or MI (72-99 years old) from 7:00 p.m. to 6:00 a.m. at a special nursing home in Tokyo. LF/HF obtained by the system correlated significantly (R = 0.89; p < 0.01) with those obtained by Holter electrocardiography (ECG). Diabetic subjects showed significantly lower LF (radar) than non-diabetic (119.8 ± 57.8 for diabetic, 405.9 ± 112.6 for non-diabetic, p < 0.01). HF (radar) of post-MI subjects was significantly lower than that of non-MI (219.7 ± 131.7 for post-MI and 580.0 ± 654.6 for non-MI, p < 0.05). Previous studies using conventional ECG reveal that diabetic neuropathy decreases LF, and also MI causes parasympathetic attenuation which leads to HF reduction. Our study showed that average SDNN of post-MI patients is smaller than 50 ms which is known to have high mortality. The non-contact autonomic activation monitoring system allows a long-term health management especially during sleeping hours for elderly people at healthcare facilities.

  11. Equine total carbon dioxide testing in Illinois in 2012.

    PubMed

    Heffron, Brendan; Benoit, Marc; Bishop, Jennifer; Costello, Sara; Hurt, Laura; Simpson, Lindsay; Taddei, Lisa; Kline, Kevin; Negrusz, Adam

    2014-10-01

    During prolonged strenuous exercise, racehorses can experience acidemia. To counteract this phenomenon, trainers can administer blood alkalizing agents that raise the plasma pH and total carbon dioxide (TCO2) concentration. In Illinois, the administrative threshold for TCO2 in plasma is 37.0 mmol/L. Because accuracy in the reported measurement of TCO2 must be ensured, uncertainty measurements are often issued alongside the reported concentrations. We report a validated method for measuring TCO2 levels in equine plasma using the Beckman UniCel DxC 600. A six-point calibration curve ranging from 5 to 50 mmol/L is analyzed along with controls at four TCO2 levels with each set of samples. Using this method, we collected data from 5,199 race samples during 2012, with 134 being from thoroughbred horses and 5,065 from standardbred horses. During method validation, uncertainty was determined using the simplified Guide to the Expression of Uncertainty in Measurement approach and was found to be 3% at 99.7% confidence level with eight measurements. Additionally, to investigate other variables that could have an effect on TCO2 levels, we collected the gender, breed, Lasix(®) status, strong ion concentration, pre- or post-race collection time and track location of all horses tested during that year. The samples had an overall mean TCO2 concentration of 30.5 ± 2.0 mmol/L. The other physiological and environmental data were analyzed using analysis of covariance tables. These results indicate gender, breed, furosemide status, collection time and track location to be strongly correlated (P < 0.0001) to TCO2 levels. Thoroughbred status was found to have no effect. Finally, TCO2 concentrations were highly correlated (P < 0.0001) to sodium and chloride ion concentrations. No correlation was found between TCO2 and potassium concentrations. The results show that there are several environmental and physiological factors that can affect TCO2 concentrations. The concentration of other

  12. Profile of the graduate student population in U.S. medical schools.

    PubMed

    Ammons, S W; Kelly, D E

    1997-09-01

    The Association of American Medical Colleges (AAMC) sponsored surveys of accredited U.S. medical schools in 1994-95 and in 1995-96 to gather enough data to determine an accurate profile of the population of students enrolled in and/or graduated from biomedical PhD and MD-PhD programs at these institutions. Previously collected data on the graduate student population at medical schools often did not distinguish between PhD students at the medical school and graduate students in other parts of the university. The AAMC surveys defined a medical school PhD- or MD-PhD-trained student as one whose major professor holds his or her primary appointment in a department of the medical school. The data were the result of census-taking by the responding schools on October 1, 1994, and October 1, 1995. There were 81 responses to each of the two surveys. Overall, 104 medical schools supplied data in either one or both of the survey years. When the data are extrapolated from the sample to the total population of 122 medical schools that award graduate degrees, a number of interesting estimates emerge. (1) When compared with the 1995 data for 18 biomedically-related biological science disciplines from the National Research Council's Survey of Earned Doctorates, the AAMC survey indicates that approximately 60% of the 4,000 PhDs awarded were earned by students studying at U.S. medical schools. (2) The total enrollment of PhD students in U.S. medical schools is approximately 18,600, a number that is about 25-30% of the number of medical students currently enrolled at all accredited U.S. medical schools. In some institutions, the number of graduate students rivals the number of medical students. (3) PhD students are enrolled in a wide variety of programs bearing titles reflective of a trend toward "interdisciplinary" rather than "departmental" degrees. (4) At a given time, the number of students supported by National Institutes of Health (NIH) research grants is nearly twice that

  13. Compositional and structural studies of nanoscale boron-doped nickel aluminide films

    NASA Astrophysics Data System (ADS)

    Sulcer, Jarvis Dwayne

    This thesis presents a detailed investigation of the composition and microstructure of boron-doped nickel aluminide thin films fabricated via ion beam sputtering. Findings are related to film growth mode, fabrication conditions, and mechanical properties. Results from the characterization of the composition and structure of Ni3Al:B films having thicknesses ranging from ˜300 to ˜2600 A deposited on substrates of plastic, NaCl and Si at a temperature of ˜300 K by Kaufman-type ion beam sputtering of a Ni3Al:B compound target are reported. The bulk composition of the films was investigated using instrumental neutron activation analysis (INAA) and Rutherford backscattering spectrometry (RBS). It was determined by INAA and RBS that the bulk Ni/Al atomic ratio of the target can be replicated in films fabricated on single crystal NaCl substrates. However, results from the measurement of the local composition by energy dispersive X-ray (EDX) and electron energy loss spectroscopy (EELS) via scanning transmission electron microscopy (STEM) reveal that the local Ni/Al atomic ratio is higher. This is the result of preferential sputtering of Ni due to recoil implantation of Al in the compound Ni3Al:B target. The spatial distribution of boron in the films was determined via neutron depth profiling (NDP). Grazing incidence X-ray diffraction studies reveal that films grown on Si and NaCl are polycrystalline and show the (111) crystallographic plane. The absence of superlattice peaks at (100), (110), (210) and (211) in the diffraction spectra indicate that the films are also in a state of disorder. It was determined from annular dark field images produced via STEM of 300, 560 A, and 600 A thin films that the average size of grains was 30 +/- 3 A. This cluster size is characteristic of films that have a very fine-grain microstructure and yield stresses of hundreds of MPa since the yield stress increases with decreasing grain size. The coalescence of clusters as observed via BF and

  14. The hybrid disks: a search and study to better understand evolution of disks

    NASA Astrophysics Data System (ADS)

    Péricaud, J.; Di Folco, E.; Dutrey, A.; Guilloteau, S.; Piétu, V.

    2017-03-01

    ://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A62

  15. Development of Coated Conductors in Japanese National Project "Development of Fundamental Technologies for HTS Coils"

    NASA Astrophysics Data System (ADS)

    Yoshizumi, Masateru; Izumi, Teruo; Shiohara, Yuh

    RE1Ba2Cu3O7-x (REBCO, RE=rare earth) coated conductors have attracted the attention of many scientists due to the high superconducting properties, etc. Due to the great progress of R&D on coated conductors, the activities have shifted to specific applications. The new Japanese national project, named as "Development of Fundamental Technologies for HTS Coils", started last year aiming for the applications of MRI and medical accelerators. To meet the requirements of those applications, the R&D of REBCO coated conductors (CCs) are being performed with that of coiling technology in parallel. The theme has two sub-themes of "development of long CCs with high in-field performance" and "development of CCs with extremely low heat generation" in this national project. The ambitious goals of these themes are set as intermediate ones due 2016 Mar; the theme of in-field: 100m-500A/cm-w@65K, 3T -850A/cm-w@35K, 10T, the theme of low heat generation: 100m-500 μm of filament width w/ Icfilament inhomogeneity of distribution within 10% and joint resistance below 5nΩ. The final goals of these themes due 2018 Mar. were set as follows; the theme of in-field: 200m-600A/cm-w@65K, 3T -1000A/cm-w@35K, 10T, the theme of low heat generation: 200m-500 μm of filament width w/ Icfilament distribution within 5% and joint resistance below 3nΩ. The objectives, goals and progress of this project will be reviewed in this article. As for the progress, for example, the combination of EuBCO+BHO was found to be effective to improve the in-field performance of PLD derived coated conductors. A 94 m long wire with Icmin of 108A/cm-w@77K, 3T (corresponding to 472A/cm-w @65K, 3T) was successfully fabricated. It is as twice Icmin of the long tape as the highest one in the previous project.

  16. Structure and dynamics of the molecular gas in M 2-9: a follow-up study with ALMA

    NASA Astrophysics Data System (ADS)

    Castro-Carrizo, A.; Bujarrabal, V.; Neri, R.; Alcolea, J.; Sánchez Contreras, C.; Santander-García, M.; Nyman, L.-A.

    2017-03-01

    Context. M 2-9 is a young planetary nebula (PN) that shows the characteristics of its last ejections in unprecedented detail. These last ejections are thought to trigger the post-asymptotic giant branch evolution. Aims: To assemble an overall picture of how M 2-9 was shaped, we analyzed the characteristics of the different molecular gas components and their relation with the warmer parts of the nebula that are visible in the optical domain. Methods: 12CO and 13CO J = 3-2 line emission maps were obtained with the Atacama Large Millimeter/submillimeter Array with high angular-resolution and sensitivity. Results: Two equatorial rings are found to host most of the cold molecular gas in M 2-9, as has been described for previous 12CO J = 2-1 emission observations. In addition, we have detected a double crown-shaped structure that is symmetric with respect to the main nebular axis, which is located 1.5'' away from both sides of the equatorial plane. Their distribution and kinematics show a very close relationship with the inner molecular ring: both are part of the same small hourglass structure formed 900 yr ago. Two clearly distinct ejections with a remarkable axial symmetry are found to have shaped the molecular gas distribution in M 2-9, in agreement with the ejection processes that were probably responsible for the optical lobes. For the first time, the physical conditions of the different molecular components in M 2-9 are comprehensively analyzed with a radiative transfer model. They are found to follow standard laws, like those obtained in other young PN, with densities and temperatures decreasing with radius and ballistic expansion. A total mass of 5 × 10-3M⊙ was derived for the detected molecular component, the larger and older equatorial ring hosting most ( 90%) of this gas. The reduced datacube (FITS file) is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600

  17. RAVE stars in K2. I. Improving RAVE red giants spectroscopy using asteroseismology from K2 Campaign 1

    NASA Astrophysics Data System (ADS)

    Valentini, M.; Chiappini, C.; Davies, G. R.; Elsworth, Y. P.; Mosser, B.; Lund, M. N.; Miglio, A.; Chaplin, W. J.; Rodrigues, T. S.; Boeche, C.; Steinmetz, M.; Matijevič, G.; Kordopatis, G.; Bland-Hawthorn, J.; Munari, U.; Bienaymé, O.; Freeman, K. C.; Gibson, B. K.; Gilmore, G.; Grebel, E. K.; Helmi, A.; Kunder, A.; McMillan, P.; Navarro, J.; Parker, Q. A.; Reid, W.; Seabroke, G.; Sharma, S.; Siviero, A.; Watson, F.; Wyse, R. F. G.; Zwitter, T.; Mott, A.

    2017-03-01

    for objects for which the difference between DR4/DR5 and seismic gravities differ by more than 0.5 dex. The method illustrated in this work will be used for analysing RAVE targets present in the other K2 campaigns, in the framework of Galactic Archaeology investigations. Data (atmospheric parameters, abundances, distances, ages and reddening) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A66

  18. A survey on knowledge and perceptions regarding head lice on a sample of teachers and students in primary schools of north and south of Italy.

    PubMed

    Sidoti, E; Bonura, F; Paolini, G; Tringali, G

    2009-09-01

    High rates of pediculosis are found in every part of the world. The age-range most affected is between 3 and 12 years. No-nit policies are ineffective in preventing infestations. On the other hand, misdiagnosis and overuse of pediculicides, increase resistance to treatment. Lack of information leads people to consider this kind of infestation to be associated to low social classes and immigrants. This research has been implemented to find out about the information level on pediculosis on a sample of students (722) and teachers (408) of some primary schools in northern and southern Italy, and to highlight the role of personal aspects such as age, gender, cultural level, geographical position which may influence this topic and, eventually, allow the use of the correct knowledge in developing appropriate procedures within the school district. Data was obtained through a questionnaire containing 21 multiple choice questions for the teachers and 14 for the students. Standard descriptive statistics were computed. chi2 tests were applied to highlight statistical association among observed variables; test for the difference of two proportions were applied to confirm significant differences among the observed proportions. The level of information for students seems to be, approximately, the same both for northern and southern Italy. There was a slight prevalence of correct answers from southern teachers, probably because the phenomenon of pediculosis has a positive trend of growth in the south. The number of correct answers was, for all, on average about 60.0%; a negative result in itself considering the simplicity of the questions. Knowledge about the biology of the louse was virtually absent. The area of prevention showed lack of information and need for improvement. Most of the teachers believe that there are specific products that can prevent infestation by louse. Most of the teachers have information which does not come from scientific sources. Students receive some short and incomplete information from their parents. Deficiencies in teachers' knowledge indicate that they are inadequately equipped to manage lice infestation. Educational interventions with teachers and families and, as a consequence, with students should be taught at school to allow a correct understanding of the pediculosis, increasing the teachers' competence and, consequently, as soon as the infestation should manifest, a rapid alert of the Health Service so that proper treatment could be provided.

  19. Millimeter-wave spectroscopy of hydantoin, a possible precursor of glycine

    NASA Astrophysics Data System (ADS)

    Ozeki, Hiroyuki; Miyahara, Rio; Ihara, Hiroto; Todaka, Satoshi; Kobayashi, Kaori; Ohishi, Masatoshi

    2017-03-01

    was created for the ground state and for the two low-lying excited states, and are ideal for a future astronomical research. The 1σ frequency accuracy is lower than 100 kHz for the lines with upper-state energy below 200 cm-1, corresponding to a velocity resolution of 0.1 km s-1 at 300 GHz The spectral line list of hydantoin is available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A44

  20. Active Features of Guguan-Guizhen Fault at the Northeast Margin of Qinghai-Tibet Block since Late Quaternary

    NASA Astrophysics Data System (ADS)

    Shi, Yaqin; Feng, Xijie; Li, Gaoyang; Ma, Ji; Li, Miao; Zhang, Yi

    2015-04-01

    Guguan-Guizhen fault is located at the northeast margin of Qinghai-Tibet Block and northwest margin of Ordos Block; it is the boundary of the two blocks, and one of the multiple faults of northwest Haiyuan-Liupanshan-Baoji fault zone. Guguan-Guizhen fault starts from Putuo Village, Huating County, Gansu Province, and goes through Badu Town, Long County in Shaanxi Province ends in Guozhen Town in Baoji City, Shaanxi Province. The fault has a full length of about 130km with the strike of 310-330°, the dip of SW and the rake of 50-60°, which is a sinistral slip reverse fault in the north part, and a sinistral slip normal fault in the southeast part. Guguan-Guizhen fault has a clear liner structure in satellite images and significant landform elevation difference with a maximum difference of 80m, and is higher in the east lower in the west. The northwest side of Guguan-Guizhen fault is composed of purplish-red Lower Cretaceous sandstones and river terrace; the northeast side is composed of Ordovician Limestone. Shigou, Piliang, Songjiashan, Tianjiagou and Chenjiagou fault profiles are found to the south of Badu Village. After 14C and optically stimulated luminescence dating, the fault does not dislocate the stratum since late Pleistocene (90.5±4.4ka) in Shigou, Piliang and Songjiashan fault profiles, and does not dislocate the cobble layer of Holocene first terrace and recent sliderock (3180±30 BP). But the fault dislocated the stratum of middle Pleistocene in some of the fault profiles. All the evidences above indicate that the fault is active in middle Pleistocene, and being silence since late Pleistocene. It might be active in Holocene to the north of Badu Village due to collapses are found in a certain area. The cause of these collapses is Qinlong M6-7 earthquake in 600 A.D., and might be relevant with Guguan-Guizhen fault after analysis of the scale, feature and age determination of the collapse. If any seismic surface rupture and ancient earthquake traces

  1. HYFLUX: Satellite Exploration of Natural Hydrocarbon Seeps and Discovery of a Methane Hydrate Mound at GC600

    NASA Astrophysics Data System (ADS)

    Garcia-Pineda, O. G.; MacDonald, I. R.; Shedd, W.; Zimmer, B.

    2009-12-01

    Analysis of natural hydrocarbon seeps is important to improve our understanding of methane flux from deeper sediments to the water column. In order to quantify natural hydrocarbon seep formations in the Northern Gulf of Mexico, a set of 686 Synthetic Aperture Radar (SAR) images was analyzed using the Texture Classifying Neural Network Algorithm (TCNNA), which processes SAR data to delineate oil slicks. This analysis resulted in a characterization of 396 natural seep sites distributed in the northern GOM. Within these sites, a maximum of 1248 individual vents where identified. Oil reaching the sea-surface is deflected from its source during transit through the water column. This presentation describes a method for estimating locations of active oil vents based on repeated slick detection in SAR. One of the most active seep formations was detected in MMS lease block GC600. A total of 82 SAR scenes (collected by RADARSAT-1 from 1995 to 2007) was processed covering this region. Using TCNNA the area covered by each slick was computed and Oil Slicks Origins (OSO) were selected as single points within detected oil slicks. At this site, oil slick signatures had lengths up to 74 km and up to 27 km^2 of area. Using SAR and TCNNA, four active vents were identified in this seep formation. The geostatistical mean centroid among all detections indicated a location along a ridge-line at ~1200m. Sea truth observations with an ROV, confirmed that the estimated location of vents had a maximum offset of ~30 m from their actual locations on the seafloor. At the largest vent, a 3-m high, 12-m long mound of oil-saturated gas hydrate was observed. The outcrop contained thousands of ice worms and numerous semi-rigid chimneys from where oily bubbles were escaping in a continuous stream. Three additional vents were found along the ridge; these had lower apparent flow, but were also plugged with gas hydrate mounds. These results support use of SAR data for precise delineation of active seep

  2. Ion acoustic waves at comet 67P/Churyumov-Gerasimenko. Observations and computations

    NASA Astrophysics Data System (ADS)

    Gunell, H.; Nilsson, H.; Hamrin, M.; Eriksson, A.; Odelstad, E.; Maggiolo, R.; Henri, P.; Vallieres, X.; Altwegg, K.; Tzou, C.-Y.; Rubin, M.; Glassmeier, K.-H.; Stenberg Wieser, G.; Simon Wedlund, C.; De Keyser, J.; Dhooghe, F.; Cessateur, G.; Gibbons, A.

    2017-03-01

    only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A3

  3. Effect of an allophanic soil on humification reactions between catechol and glycine: Spectroscopic investigations of reaction products

    NASA Astrophysics Data System (ADS)

    Fukushima, Masami; Miura, Akitaka; Sasaki, Masahide; Izumo, Kenji

    2009-01-01

    Adduction of amino acids to phenols is a possible humification reaction pathway [F.J. Stevenson, Humus Chemistry: Genesis, Composition, Reaction, second ed., Wiley, New York, 1994, pp. 188-211; M.C. Wang, P.M. Huang, Sci. Total Environ. 62 (1987) 435; M.C. Wang, P.M. Huang, Soil Sci. Soc. Am. J. 55 (1991) 1156; M.C. Wang, P.M. Huang, Geoderma 112 (2003) 31; M.C. Wang, P.M. Huang, Geoderma 124 (2005) 415]. To elucidate the reaction kinetics and products of abiotic humification, the effects of an allophanic soil on the adduction of amino acids to phenols were investigated using catechol (CT) and glycine (Gly) as a model phenol and amino acid, respectively. An aqueous solution containing CT and Gly (pH 7.0) in the presence of allophanic soil was incubated for 2 weeks, and the kinetics of the humification reactions were monitored by analysis of absorptivity at 600 nm ( E600). A mixture of CT and Gly in the absence of allophanic soil was used as a control. The E600 value increased markedly in the presence of allophanic soil. In addition, unreacted CT was detected in the control reaction mixture, but not in the allophane-containing reaction mixture. Under the sterilized conditions, absorbance at 600 nm for the control reaction mixture was significantly smaller than that for the allophanic soil-containing reaction mixture, which indicates there was no microbial participation during incubation. These results indicate that the allophanic soil effectively facilitated humification reactions between CT and Gly. The reaction mixtures were acidified and humic-like acid (HLA) was isolated as a precipitate. The elemental composition, acidic functional group contents, molecular weight, FT-IR, solid-state CP-MAS 13C NMR, and 1H NMR spectra of the purified HLAs were analyzed. The results of these analyses indicate that the nitrogen atom of Gly binds to the aromatic carbon of CT in the HLA products.

  4. Kinetic temperature of massive star-forming molecular clumps measured with formaldehyde. II. The Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Tang, X. D.; Henkel, C.; Chen, C.-H. R.; Menten, K. M.; Indebetouw, R.; Zheng, X. W.; Esimbek, J.; Zhou, J. J.; Yuan, Y.; Li, D. L.; He, Y. X.

    2017-03-01

    kinetic temperatures derived from para-H2CO 321-220/303-202 and NH3(2, 2)/(1, 1) shows a drastic difference, however. In the star-forming region N159W, the gas temperature derived from the NH3(2, 2)/(1, 1) line ratio is 16 K (Ott et al. 2010, ApJ, 710, 105), which is only half the temperature derived from para-H2CO and the dust. Furthermore, ammonia shows a very low abundance in a 30'' beam. Apparently, ammonia only survives in the most shielded pockets of dense gas that are not yet irradiated by UV photons, while formaldehyde, less affected by photodissociation, is more widespread and also samples regions that are more exposed to the radiation of young massive stars. A correlation between the gas kinetic temperatures derived from para-H2CO and infrared luminosity, represented by the 250 μm flux, suggests that the kinetic temperatures traced by para-H2CO are correlated with the ongoing massive star formation in the LMC. The reduced spectra (FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A16

  5. Electromagnetic earthquake triggering phenomena: State-of-the-art research and future developments

    NASA Astrophysics Data System (ADS)

    Zeigarnik, Vladimir; Novikov, Victor

    2014-05-01

    Developed in the 70s of the last century in Russia unique pulsed power systems based on solid propellant magneto-hydrodynamic (MHD) generators with an output of 10-500 MW and operation duration of 10 to 15 s were applied for an active electromagnetic monitoring of the Earth's crust to explore its deep structure, oil and gas electrical prospecting, and geophysical studies for earthquake prediction due to their high specific power parameters, portability, and a capability of operation under harsh climatic conditions. The most interesting and promising results were obtained during geophysical experiments at the test sites located at Pamir and Northern Tien Shan mountains, when after 1.5-2.5 kA electric current injection into the Earth crust through an 4 km-length emitting dipole the regional seismicity variations were observed (increase of number of weak earthquakes within a week). Laboratory experiments performed by different teams of the Institute of Physics of the Earth, Joint Institute for High Temperatures, and Research Station of Russian Academy of Sciences on observation of acoustic emission behavior of stressed rock samples during their processing by electric pulses demonstrated similar patterns - a burst of acoustic emission (formation of cracks) after application of current pulse to the sample. Based on the field and laboratory studies it was supposed that a new kind of earthquake triggering - electromagnetic initiation of weak seismic events has been observed, which may be used for the man-made electromagnetic safe release of accumulated tectonic stresses and, consequently, for earthquake hazard mitigation. For verification of this hypothesis some additional field experiments were carried out at the Bishkek geodynamic proving ground with application of pulsed ERGU-600 facility, which provides 600 A electric current in the emitting dipole. An analysis of spatio-temporal redistribution of weak regional seismicity after ERGU-600 pulses, as well as a response

  6. Star formation towards the Galactic H II region RCW 120. Herschel observations of compact sources

    NASA Astrophysics Data System (ADS)

    Figueira, M.; Zavagno, A.; Deharveng, L.; Russeil, D.; Anderson, L. D.; Men'shchikov, A.; Schneider, N.; Hill, T.; Motte, F.; Mège, P.; LeLeu, G.; Roussel, H.; Bernard, J.-P.; Traficante, A.; Paradis, D.; Tigé, J.; André, P.; Bontemps, S.; Abergel, A.

    2017-04-01

    without background subtraction. The cold regions observed outside the ionized gas are the densest and host star formation when the column density exceeds 2 × 1022 cm-2. The most reliable 35 compact sources are discussed. Using existing CO data and morphological arguments we show that these sources are likely to be associated with the RCW 120 region. These sources' volume densities range from 2 × 105 cm-3 to 108 cm-3. Five sources have envelope masses larger than 50 M⊙ and are all observed in high column density regions (>7 × 1022 cm-2). We find that the evolutionary stage of the sources primarily depends on the density of their hosting condensation and is not correlated with the distance to the ionizing star. Conclusions: The Herschel data, with their unique sampling of the far infrared domain, have allowed us to characterize the properties of compact sources observed towards RCW 120 for the first time. We have also been able to determine the envelope temperature, envelope mass and evolutionary stage of these sources. Using these properties we have shown that the density of the condensations that host star formation is a key parameter of the star-formation history, irrespective of their projected distance to the ionizing stars. Table A.1 is also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A93Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  7. Basaltic Lava Channels

    NASA Astrophysics Data System (ADS)

    Cashman, K. V.; Griffiths, R. W.; Kerr, R. C.

    2004-12-01

    In Hawaii, the mode of lava transport - through open channels or through insulating lava tubes - determines the thermal, rheological, and emplacement history of a lava flow. Most Hawaiian lavas are erupted at near-liquidus temperatures and are therefore crystal-poor; lava transport through open channels allows rapid cooling and consequent rapid increases in lava crystallinity. Solidified aa flows resulting from channelized flow are typically fine-grained throughout their thickness, indicating cooling of the entire flow thickness during transport. In contrast, transport of lava through insulating tubes permits flow over long distances with little cooling. Flows emerging from such tubes typically have pahoehoe flow surfaces with glassy crusts. Groundmass textures that coarsen from the flow rind to the interior reflect rates of post-emplacement, rather than syn-emplacement, cooling. To distinguish eruption conditions that result in lava channels from those that allow formation of lava tubes, we have performed a series of laboratory experiments involving injection of PEG 600 (a wax with a Newtonian rheology and freezing temperature of 19ºC) into cold water through both uniform and non-uniform sloping channels. In uniform channels, tube formation can be distinguished from open channel flow using a dimensionless parameter based on a solidification time scale, an advection time scale, and a Rayleigh number that describes convection by heat loss from crust-free shear zones. Theoretical analysis predicts that in the open channel regime, the width of the crust (dc) will vary with the channel width (W) as dc = W5/3. Crustal coverage of non-uniform channels in both laboratory experiments and field examples from Kilauea Volcano, Hawaii, is consistent with this prediction. However, experiments in non-uniform channels illustrate additional controls on the surface coverage of lava channels. Most important is crustal extension resulting from flow acceleration through constrictions

  8. SOFIA/GREAT [C ii] observations in nearby clouds near the lines of sight towards B0355+508 and B0212+735

    NASA Astrophysics Data System (ADS)

    Glück, C. B.; Stutzki, J.; Röllig, M.; Chambers, E. T.; Risacher, C.

    2017-04-01

    cold PDRs can reproduce the observed CO intensities, the observed CO(1-0) and CO(2-1) ratio, and the observed upper limits for [C ii]. The reduced spectra (FITS files) are available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A94

  9. Lava Flow Ages and Geologic Mapping on Mid-ocean Ridges

    NASA Astrophysics Data System (ADS)

    Clague, D. A.; Paduan, J. B.; Dreyer, B. M.; Caress, D. W.

    2010-12-01

    of nearby samples commonly yield statistically identical ages, and a few cores where multiple layers were dated show increasing age with depth. Estimated flow ages are 550-7100 aBP for 10 samples from flows within ~1 km of historic flows at CoAxial, and 475-4600 aBP for 11 samples from flows within ~0.5 km of the 1986 North Cleft pillow mounds. Seven flows from the floor of Axial caldera range from 600 to 1160 aBP, whereas two flows from the southeast rim are 905 and 2005 aBP. These dated flows are plagioclase phyric with glass MgO>7.5%. Other flows on the caldera floor are aphyric, have glass MgO<7.3%, and have sediment too thin to sample. They are inferred to be <600 years BP. A significant change in the Axial Volcano magma reservoir apparently occurred ~600 aBP. A sample from 15 cm depth within a 2-m volcaniclastic unit on the eastern rim of the caldera is 6910 aBP and suggests formation of the caldera several tens of thousands aBP. A cone near a deep lava pond on the south rift of Axial Seamount is ~16,580 aBP. Five samples from the lava pond and nearby flows are 950-1510 aBP. Geologic maps of the ridge system can now be constructed in much the same way they have been done on land for many years.

  10. Spectral variations of the symbiotic star V407 Cygni around light maximum of the secondary Mira variable in 2012

    NASA Astrophysics Data System (ADS)

    Iijima, T.; Naito, H.

    2017-04-01

    .1. Since the mass transfer rate seems to have been closely related to the pulsation of the secondary component, the mass transfer in this binary system was likely due to a normal Roche-lobe overflow. If this is the case, the orbital period should be shorter than five years. Each of the Na I D1 and D2 lines had five emission and one absorption components around the light maximum. It seems that there were two pairs of mass outflows from the Mira variable with velocities of ± 79 km s-1 and ± 44 km s-1. These velocities were much higher than those of mass loss from usual Mira variables. The reduced spectra (FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A96

  11. Resolved magnetic structures in the disk-halo interface of NGC 628

    NASA Astrophysics Data System (ADS)

    Mulcahy, D. D.; Beck, R.; Heald, G. H.

    2017-03-01

    -scale dynamo where the regular magnetic field is not coupled to the gas flow and obtains a significant radial component. We additionally discover a lone region of ordered magnetic field to the north of the galaxy with a high degree of polarisation and a small pitch angle, a feature that has not been observed in any other galaxy so far and is possibly caused by an asymmetric H I hole. Conclusions: Until now NGC 628 has been relatively unexplored in radio continuum but with its extended H I disk and lack of active star formation in its central region has produced a wealth of interesting magnetic phenomena. We observe evidence for two drivers of magnetic turbulence in the disk-halo connection of NGC 628, namely, Parker instabilities and superbubbles. The reduced images/datacubes (FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A6

  12. The AMBRE project: Iron-peak elements in the solar neighbourhood

    NASA Astrophysics Data System (ADS)

    Mikolaitis, Š.; de Laverny, P.; Recio-Blanco, A.; Hill, V.; Worley, C. C.; de Pascale, M.

    2017-03-01

    clearly demonstrated that Zn is an α-like element and could be used to separate thin and thick disc stars. Moreover, we show that the [Mn/Mg] ratio could also be a very good tool for tagging Galactic substructures. From the comparison with Galactic chemical evolutionary models, we conclude that some recent models can partially reproduce the observed Mg, Zn, and, Cu behaviours in thin and thick discs and metal-poor sequences. Models mostly fail to reproduce Mn and Ni in all metallicity domains, however, models adopting yields normalised from solar chemical properties reproduce Mn and Ni better, suggesting that there is still a lack of realistic theoretical yields of some iron-peak elements. The very low scatter (≈0.05 dex) in thin and thick disc sequences could provide an observational constrain for Galactic evolutionary models that study the efficiency of stellar radial migration. Based on observations collected at ESO telescopes under the AMBRE programme. Full Table 5 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A22

  13. PROTOPLANETARY DISK MASSES FROM STARS TO BROWN DWARFS

    SciTech Connect

    Mohanty, Subhanjoy; Mortlock, Daniel; Greaves, Jane; Pascucci, Ilaria; Apai, Daniel; Scholz, Aleks; Thompson, Mark; Lodato, Giuseppe; Looper, Dagny

    2013-08-20

    We present SCUBA-2 850 {mu}m observations of seven very low mass stars (VLMS) and brown dwarfs (BDs). Three are in Taurus and four in the TW Hydrae Association (TWA), and all are classical T Tauri (cTT) analogs. We detect two of the three Taurus disks (one only marginally), but none of the TWA ones. For standard grains in cTT disks, our 3{sigma} limits correspond to a dust mass of 1.2 M{sub Circled-Plus} in Taurus and a mere 0.2 M{sub Circled-Plus} in the TWA (3-10 Multiplication-Sign deeper than previous work). We combine our data with other submillimeter/millimeter (sub-mm/mm) surveys of Taurus, {rho} Oph, and the TWA to investigate the trends in disk mass and grain growth during the cTT phase. Assuming a gas-to-dust mass ratio of 100:1 and fiducial surface density and temperature profiles guided by current data, we find the following. (1) The minimum disk outer radius required to explain the upper envelope of sub-mm/mm fluxes is {approx}100 AU for intermediate-mass stars, solar types, and VLMS, and {approx}20 AU for BDs. (2) While the upper envelope of apparent disk masses increases with M{sub *} from BDs to VLMS to solar-type stars, no such increase is observed from solar-type to intermediate-mass stars. We propose this is due to enhanced photoevaporation around intermediate stellar masses. (3) Many of the disks around Taurus and {rho} Oph intermediate-mass and solar-type stars evince an opacity index of {beta} {approx} 0-1, indicating significant grain growth. Of the only four VLMS/BDs in these regions with multi-wavelength measurements, three are consistent with considerable grain growth, though optically thick disks are not ruled out. (4) For the TWA VLMS (TWA 30A and B), combining our 850 {mu}m fluxes with the known accretion rates and ages suggests substantial grain growth by 10 Myr, comparable to that in the previously studied TWA cTTs Hen 3-600A and TW Hya. The degree of grain growth in the TWA BDs (2M1207A and SSPM1102) remains largely unknown. (5) A

  14. Correcting for initial Th in speleothems to obtain the age of calcite nucleation after a growth hiatus

    NASA Astrophysics Data System (ADS)

    Richards, D. A.; Nita, D. C.; Moseley, G. E.; Hoffmann, D. L.; Standish, C. D.; Smart, P. L.; Edwards, R.

    2013-12-01

    contiguous layers sub-sampled from the first 2-3 mm of flowstone growth after the MIS 5 hiatus, using a sub-sample milling strategy that matches spatial resolution with maximum achievable precision (ThermoFinnigan Neptune MC-ICPMS methodology; 20-30 mg calcite, U = ~ 300 ng.g-1, 2σ age uncertainty is × 600 a at ~80 ka). Isochron methods are used to estimate the range of initial 230Th/232Th ratio and are compared with elevated values obtained from stalagmites from the same cave (Beck et al, 2001; Hoffmann et al, 2010). A similar strategy is presented for a stalagmite with much faster axial growth data, and the data are combined with additional sea level information from the same region to estimate the rate and uncertainty of sea level regression at the MIS stage 5/4 boundary. Elevated initial 230Th/232Th values have also been observed in a stalagmite from 6 m below present sea level in a cenote from the Yucatan, Mexico, where 5 phases of calcite between 10 and 5.5 ka are separated by serpulid worm tubes formed during periods of submergence. The transition between each phase provides constraints on age and elevation of relative sea level, but the former is hampered by the uncertainty of the high initial 230Th/232Th correction. We consider the possible sources of elevated Th ratios: hydrogenous, colloidal and carbonate or other detrital components.

  15. The VLT-FLAMES Tarantula Survey. XXV. Surface nitrogen abundances of O-type giants and supergiants

    NASA Astrophysics Data System (ADS)

    Grin, N. J.; Ramírez-Agudelo, O. H.; de Koter, A.; Sana, H.; Puls, J.; Brott, I.; Crowther, P. A.; Dufton, P. L.; Evans, C. J.; Gräfener, G.; Herrero, A.; Langer, N.; Lennon, D. J.; van Loon, J. Th.; Markova, N.; de Mink, S. E.; Najarro, F.; Schneider, F. R. N.; Taylor, W. D.; Tramper, F.; Vink, J. S.; Walborn, N. R.

    2017-04-01

    . Conclusions: While the surface abundances of 60-70 percent of presumed single O-type giants to supergiants behave in conformity with expectations, at least 30-40 percent of our sample can not be understood in the current framework of rotational mixing for single stars. Even though we have excluded stars showing radial velocity variations, of our sample may have remained contaminated by post-interaction binary products. Hence, it is plausible that effects of binary interaction need to be considered to understand their surface properties. Alternatively, or in conjunction, the effects of magnetic fields or alternative mass-loss recipes may need to be invoked. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programme 182.D-0222.Tables 2, A.1 and A.2 are available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A82

  16. Processing and characterization of superconducting solenoids made of Bi-2212/Ag-alloy multifilament round wire for high field magnet applications

    NASA Astrophysics Data System (ADS)

    Chen, Peng

    As the only high temperature superconductor with round wire (RW) geometry, Bi2Sr2CaCu2O8+x (Bi-2212) superconducting wire has the advantages of being multi-filamentary, macroscopically isotropic and twistable. With overpressure (OP) processing techniques recently developed by our group at the National High Magnetic Field Laboratory (NHMFL), the engineering current density (Je) of Bi-2212 RW can be dramatically increased. For example, Je of more than 600 A/mm 2 (4.2 K and 20 T) is achieved after 100 bar OP processing. With these intrinsically beneficial properties and recent processing progress, Bi-2212 RW has become very attractive for high field magnet applications, especially for nuclear magnetic resonance (NMR) magnets and accelerator magnets etc. This thesis summarizes my graduate study on Bi-2212 solenoids for high field and high homogeneity NMR magnet applications, which mainly includes performance study of Bi-2212 RW insulations, 1 bar and OP processing study of Bi-2212 solenoids, and development of superconducting joints between Bi-2212 RW conductors. Electrical insulation is one of the key components of Bi-2212 coils to provide sufficient electrical standoff within coil winding pack. A TiO 2/polymer insulation offered by nGimat LLC was systematically investigated by differential thermal analysis (DTA), thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), dielectric property measurements, and transport critical current (Ic) property measurements. About 29% of the insulation by weight is polymer. When the Bi-2212 wire is fully heat treated, this decomposes with slow heating to 400 °C in flowing O2. After the full reaction, we found that the TiO2 did not degrade the critical current properties, adhered well to the conductor, and provided a breakdown voltage of more than 100 V. A Bi-2212 RW wound solenoid coil was built using this insulation being offered by nGimat LLC. The coil resistance was constant through coil winding, polymer burn

  17. Relics in galaxy clusters at high radio frequencies

    NASA Astrophysics Data System (ADS)

    Kierdorf, M.; Beck, R.; Hoeft, M.; Klein, U.; van Weeren, R. J.; Forman, W. R.; Jones, C.

    2017-03-01

    fronts that are observed edge-on. The polarization degrees correspond to Mach numbers of >2.2. Polarized emission is also detected in the radio relics in ZwCl 0008+52 and, for the first time, in Abell 1612. The smaller sizes and lower degrees of polarizations of the latter relics indicate a weaker shock and/or an inclination between the relic and the sky plane. Abell 1612 shows a complex X-ray surface brightness distribution, indicating a recent major merger and supporting the classification of the radio emission as a radio relic. In our cluster sample, no wavelength-dependent Faraday depolarization is detected between 4.85 GHz and 8.35 GHz, except for one component of the Toothbrush relic. Faraday depolarization between 1.38 GHz and 8.35 GHz varies with distance from the center of the host cluster 1RXS 06+42, which can be explained by a decrease in electron density and/or in strength of a turbulent (or tangled) magnetic field. Faraday rotation measures show large-scale gradients along the relics, which cannot be explained by variations in the Milky Way foreground. Conclusions: Single-dish telescopes are ideal tools to confirm relic candidates and search for new relic candidates. Measurement of the wavelength-dependent depolarization along the Toothbrush relic shows that the electron density of the intra-cluster medium (ICM) and strength of the tangled magnetic field decrease with distance from the center of the foreground cluster. Large-scale regular fields appear to be present in intergalactic space around galaxy clusters. Based on observations with the 100-m telescope at Effelsberg, operated by the Max-Planck-Institut für Radioastronomie (MPIfR) on behalf of the Max-Planck-Gesellschaft.The reduced Stokes parameter images (FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A18

  18. The VLT-FLAMES Tarantula Survey . XXIV. Stellar properties of the O-type giants and supergiants in 30 Doradus

    NASA Astrophysics Data System (ADS)

    Ramírez-Agudelo, O. H.; Sana, H.; de Koter, A.; Tramper, F.; Grin, N. J.; Schneider, F. R. N.; Langer, N.; Puls, J.; Markova, N.; Bestenlehner, J. M.; Castro, N.; Crowther, P. A.; Evans, C. J.; García, M.; Gräfener, G.; Herrero, A.; van Kempen, B.; Lennon, D. J.; Maíz Apellániz, J.; Najarro, F.; Sabín-Sanjulián, C.; Simón-Díaz, S.; Taylor, W. D.; Vink, J. S.

    2017-04-01

    systematically positioned between giants and supergiants at Minit ≳ 25 M⊙. At masses below 60 M⊙, the dwarf phase clearly precedes the giant and supergiant phases; however this behavior seems to break down at Minit ≲ 18 M⊙. Here, stars classified as late O III and II stars occupy the region where O9.5-9.7 V stars are expected, but where few such late O V stars are actually seen. Though we can not exclude that these stars represent a physically distinct group, this behavior may reflect an intricacy in the luminosity classification at late O spectral subtype. Indeed, on the basis of a secondary classification criterion, the relative strength of Si iv to He i absorption lines, these stars would have been assigned a luminosity class IV or V. Except for five stars, the helium abundance of our sample stars is in agreement with the initial LMC composition. This outcome is independent of their projected spin rates. The aforementioned five stars present moderate projected rotational velocities (i.e., νesini < 200kms-1) and hence do not agree with current predictions of rotational mixing in main-sequence stars. They may potentially reveal other physics not included in the models such as binary-interaction effects. Adopting theoretical results for the wind velocity law, we find modified wind momenta for LMC stars that are 0.3 dex higher than earlier results. For stars brighter than 105 L⊙, that is, in the regime of strong stellar winds, the measured (unclumped) mass-loss rates could be considered to be in agreement with line-driven wind predictions if the clump volume filling factors were fV 1/8 to 1/6. Based on observations collected at the European Southern Observatory under program ID 182.D-0222.Tables C.1-C.5 are also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A81

  19. Farmyard Manure and Fertilizer Effects on Seed Potato (Solanum tuberosum L.) Yield in Green House Production

    NASA Astrophysics Data System (ADS)

    László, M.

    2009-04-01

    alta potencialidade (boa textura e adequada retenção de agua). Efeito do nitrogênio No Brazíl em todas regiões onde se cultiva batata é raro encontrar solos com elevado teor de nitrogênio e que não precisam de quantidades desta elemento. É o elemento que governa o padrão de desenvolvimento da planta, estimulando principalmente o crescimento da parte aérea (Kádár et all. 2000., László 2000.). Para se obter rendimento de tubérculos é necessário um rápido e curto periodo de desenvolvimento da parte aérea e uma fase de acúmulo maior possível. Para tanto, devem ser evitadas doses muito altas de nitrogênio e, principalmente, se aplicadas tardiamente, pois haverá demasiado desenvolvimento de folhas que demorarão mais a finalizar seu crescimento e maturação. Isto implicará na redução do periodo de intenso desenvolvimento dos tubérculos e armazenagem do amido, resultando em menor produção. Há risco para a saúde na ingestão de alimentos com altos teores de nitrato e nitrito, havendo preocupação com o efeito de doses mais altas de nitrogênio sobre os teores dos mesmos nos tuberculos. Embora haja diferenças entre cultivares, localidades e períodos de armazenamento, há estudos mostrando que a fertilização com até 150 kg ha-1 de nitrogênio não foi suficiente para propiciar niveis preocupantes de nitrato nos tuberculos colhidos. Efeito do fósforo A grande maioria dos solos brasileiros cultivados com batata apresentam limitações ao bom desenvolvimento e produção da cultura em função dos baixos níveis de fósforo. Isto significa que aumentos de produção quase sempre ocorrem quando o solo recebe adubação fosfatada (László 2001a.). Estes aumentos são mais marcantes em solos nunca antes adubados ou com baixo teor de fósforo. Nestes, dificilmente alcanca- se a produção máxima com níveis reduzidos de fósforo. Não seria exagerado supor níveis de 600 a 800 kg ha-1 de P2O5, como sendo aqueles que iriam proporcionar produ

  20. UVES Analyses the Universe: A First Portfolio of Most Promising Results

    NASA Astrophysics Data System (ADS)

    2000-04-01

    type of observation. ESO PR Photo 09b/00 ESO PR Photo 09b/00 [Preview - JPEG: 400 x 337 pix - 39k] [Normal - JPEG: 800 x 673 pix - 84k] Caption : ESO PR Photo 09b/00 shows a spectrum of the metal-poor star G271-162 in the red spectral region around the Li-line at 671 nm that is used to derive the lithium isotopic ratio. The wavelengths of the doublet components of the two isotopes are indicated. The total exposure time was 3 hours and the S/N-ratio in the continuum region is above 600 - a most satisfactory result considering that the CCD fringing amplitude is more than 20% at these wavelengths. The open circles correspond to the observed data and the fully drawn line to a model atmosphere synthesis with isotopic ratio 6 Li/ 7 Li = 0.02; see the text. The inserted profile of a nearby thorium line from the calibration lamp represents the instrumental profile of UVES ; it has Full-Width-Half-Maximum (FWHM) of 0.056 mÅ, corresponding to a resolution of R = 112,000. The stellar line broadening function needed for such a study is determined from several other lines available in the recorded UVES spectrum. An important byproduct of this spectrum is detailed knowledge about the turbulent motions in the atmosphere of the star. The UVES observation of the metal-poor ([Fe/H] = -2.2) halo star G271-162 (V = 10.35) at a spectral resolution ~ 110,000 was included in the commissioning programme to prove this instrumental capability. This star is representative of a group of about 50 halo turn-off stars that are too faint to be studied with high-resolution spectrographs at 4-m class telescopes. A total of around 3 hours of integration was obtained in excellent seeing through a slit opened to 0.3 arcsec. The S/N of the summed, reduced spectrum, cf. PR Photo 09b/00 , is higher than 600. It is obvious that the profile of the Li line in G271-162 is considerably broader than the instrumental profile. This is due to Doppler-broadening in the stellar atmosphere, caused by thermal and gas