NASA Technical Reports Server (NTRS)
Gao, L.; Meng, R. L.; Xue, Y. Y.; Hor, P. H.; Chu, C. W.
1991-01-01
Using a recently developed pulsed critical current density (Jc) measuring system, the Jc of the high-Jc melt-textured YBa2Cu3O(7-delta) (Y123) bulk samples has been determined. I-V curves with a voltage resolution of 0.5 microV were obtained, and transport Jc's along the a-b plane as high as 7.2 x 10 to the 4th A/sq cm were extracted. These results are comparable to the values obtained magnetically. On the other hand, transport Jc along the c axis were found to be two orders of magnitude smaller, even though the magnetic Jc along the c axis is only about five times smaller than Jc along the a-b plane. It is suggested that for the high-temperature superconducting materials which are highly anisotropic, caution should be taken when using the nontransport magnetic methods to determine Jc.
NASA Astrophysics Data System (ADS)
Yamasaki, H.; Endo, K.; Nakagawa, Y.; Umeda, M.; Kosaka, S.; Misawa, S.; Yoshida, S.; Kajimura, K.
1992-10-01
Critical current densities Jc were measured in as-deposited, c-axis-oriented Bi2Sr2Ca2Cu3Ox thin films with Tc values as high as 97 K, which were prepared by metalorganic chemical-vapor deposition. These films showed high Jc (≳109 A/m2) at 77.3 K in high magnetic fields (≥1 T, H∥a-b plane). The best values are 3.3×109 A/m2 at 1 T and 9.1×108 A/m2 at 8 T, which are the highest Jc for Bi-oxide thin films among those reported so far. There were no signs of weak links in the Jc(H) behavior, and the surface morphology examined by scanning electron microscopy showed no apparent grain boundaries. The values of Jc decreased sharply when the applied field deviated from the a-b plane, and went to zero at the angles where the field component in the c direction is nearly equal to the irreversibility field Hc2* parallel to the c axis. The angular dependence of Jc of these films is most reasonably explained by the theory of intrinsic pinning.
Effects of bending on the superconducting critical current density of monofilamentary Nb3Sn wires
NASA Astrophysics Data System (ADS)
Kaiho, K.; Luhman, T. S.; Suenaga, M.; Sampson, W. B.
1980-02-01
Variations in the superconducting current density Jc of the Nb3Sn wires upon bending were measured for a series of monofilamentary wires in which the ratio Rv of the matrix (Cu+Sn) to the core (Nb3Sn,Nb) was changed from 0 to 58. In most cases Jc was found to increase slightly until the bending strain exceeded a value of ɛirrB , beyond which it severely and irreversibly degraded. For wires with intermediate values of Rv (˜2 to 10), ɛirrB , calculated by geometrical considerations, was substantially lower than the measured value of the tensile strain ɛirrT which was required to irreversibly degrade the critical current. The influence of bending strains on Jc can qualitatively be described by considering residual prestrains in the matrix and the core.
NASA Astrophysics Data System (ADS)
Kim, S. I.; Gurevich, A.; Song, X.; Li, X.; Zhang, W.; Kodenkandath, T.; Rupich, M. W.; Holesinger, T. G.; Larbalestier, D. C.
2006-09-01
We report on the thickness dependence of the superconducting characteristics including critical current Ic, critical current density Jc, transition temperature Tc, irreversibility field Hirr, bulk pinning force plot Fp(H), and normal state resistivity curve ρ(T) measured after successive ion milling of ~1 µm thick high-Ic YBa2Cu3O7-x films made by an ex situ metal-organic deposition process on Ni-W rolling-assisted biaxially textured substrates (RABiTSTM). In contrast to many recent data, mostly on in situ pulsed laser deposition (PLD) films, which show strong depression of Jc with increasing film thickness t, our films exhibit only a weak dependence of Jc on t. The two better textured samples had full cross-section average Jc,avg (77 K, 0 T) ~4 MA cm-2 near the buffer layer interface and ~3 MA cm-2 at full thickness, despite significant current blocking due to ~30% porosity in the film. Taking account of the thickness dependence of the porosity, we estimate that the local, vortex-pinning current density is essentially independent of thickness, while accounting for the additional current-blocking effects of grain boundaries leads to local, vortex-pinning Jc values well above 5 MA cm-2. Such high local Jc values are produced by strong three-dimensional vortex pinning which subdivides vortex lines into weakly coupled segments much shorter than the film thickness.
Strongly enhanced current densities in Sr0.6K0.4Fe2As2 + Sn superconducting tapes.
Lin, He; Yao, Chao; Zhang, Xianping; Zhang, Haitao; Wang, Dongliang; Zhang, Qianjun; Ma, Yanwei; Awaji, Satoshi; Watanabe, Kazuo
2014-03-25
Improving transport current has been the primary topic for practical application of superconducting wires and tapes. However, the porous nature of powder-in-tube (PIT) processed iron-based tapes is one of the important reasons for low critical current density (Jc) values. In this work, the superconducting core density of ex-situ Sr0.6K0.4Fe2As2 + Sn tapes, prepared from optimized precursors, was significantly improved by employing a simple hot pressing as an alternative route for final sintering. The resulting samples exhibited optimal critical temperature (Tc), sharp resistive transition, small resistivity and high Vickers hardness (Hv) value. Consequently, the transport Jc reached excellent values of 5.1 × 10(4) A/cm(2) in 10 T and 4.3 × 10(4) A/cm(2) in 14 T at 4.2 K, respectively. Our tapes also exhibited high upper critical field Hc2 and almost field-independent Jc. These results clearly demonstrate that PIT pnictide wire conductors are very promising for high-field magnet applications.
Strongly enhanced current densities in Sr0.6K0.4Fe2As2 + Sn superconducting tapes
Lin, He; Yao, Chao; Zhang, Xianping; Zhang, Haitao; Wang, Dongliang; Zhang, Qianjun; Ma, Yanwei; Awaji, Satoshi; Watanabe, Kazuo
2014-01-01
Improving transport current has been the primary topic for practical application of superconducting wires and tapes. However, the porous nature of powder-in-tube (PIT) processed iron-based tapes is one of the important reasons for low critical current density (Jc) values. In this work, the superconducting core density of ex-situ Sr0.6K0.4Fe2As2 + Sn tapes, prepared from optimized precursors, was significantly improved by employing a simple hot pressing as an alternative route for final sintering. The resulting samples exhibited optimal critical temperature (Tc), sharp resistive transition, small resistivity and high Vickers hardness (Hv) value. Consequently, the transport Jc reached excellent values of 5.1 × 104 A/cm2 in 10 T and 4.3 × 104 A/cm2 in 14 T at 4.2 K, respectively. Our tapes also exhibited high upper critical field Hc2 and almost field-independent Jc. These results clearly demonstrate that PIT pnictide wire conductors are very promising for high-field magnet applications. PMID:24663054
Strongly enhanced current densities in Sr0.6K0.4Fe2As2 + Sn superconducting tapes
NASA Astrophysics Data System (ADS)
Lin, He; Yao, Chao; Zhang, Xianping; Zhang, Haitao; Wang, Dongliang; Zhang, Qianjun; Ma, Yanwei; Awaji, Satoshi; Watanabe, Kazuo
2014-03-01
Improving transport current has been the primary topic for practical application of superconducting wires and tapes. However, the porous nature of powder-in-tube (PIT) processed iron-based tapes is one of the important reasons for low critical current density (Jc) values. In this work, the superconducting core density of ex-situ Sr0.6K0.4Fe2As2 + Sn tapes, prepared from optimized precursors, was significantly improved by employing a simple hot pressing as an alternative route for final sintering. The resulting samples exhibited optimal critical temperature (Tc), sharp resistive transition, small resistivity and high Vickers hardness (Hv) value. Consequently, the transport Jc reached excellent values of 5.1 × 104 A/cm2 in 10 T and 4.3 × 104 A/cm2 in 14 T at 4.2 K, respectively. Our tapes also exhibited high upper critical field Hc2 and almost field-independent Jc. These results clearly demonstrate that PIT pnictide wire conductors are very promising for high-field magnet applications.
Critical current densities of powder-in-tube MgB2 tapes fabricated with nanometer-size Mg powder
NASA Astrophysics Data System (ADS)
Yamada, H.; Hirakawa, M.; Kumakura, H.; Matsumoto, A.; Kitaguchi, H.
2004-03-01
We fabricated powder-in-tube MgB2/Fe tapes using a powder mixture of nanometer-size Mg and commercial amorphous B and investigated the transport properties. High-purity nanometer-size Mg powder was fabricated by applying the thermal plasma method. 5-10 mol % SiC powder doping was tried to enhance the Jc properties. We found that the use of nanometer-size Mg powder was effective to increase the Jc values. The transport Jc values of the nondoped and 10 mol % SiC-doped tapes prepared with nanometer-size Mg powder reached 90 and 250 A/mm2 at 4.2 K and 10 T, respectively. These values were about five times higher than those of the tapes prepared with commercial Mg powder.
NASA Astrophysics Data System (ADS)
Miura, S.; Yoshida, Y.; Ichino, Y.; Xu, Q.; Matsumoto, K.; Ichinose, A.; Awaji, S.
2016-01-01
For use in high-magnetic-field coil-based applications, the critical current density (Jc) of REBa2Cu3Oy (REBCO, where RE = rare earth) coated conductors must be isotropically improved, with respect to the direction of the magnetic field; these improvements must be realized at the operating conditions of these applications. In this study, improvement of the Jc for various applied directions of magnetic field was achieved by controlling the morphology of the BaHfO3 (BHO) nano-rods in a SmBCO film. We fabricated the 3.0 vol. % BHO-doped SmBCO film at a low growth temperature of 720 °C, by using a seed layer technique (Ts = 720 °C film). The low-temperature growth resulted in a morphological change in the BHO nano-rods. In fact, a high number density of (3.1 ± 0.1) × 103 μm-2 of small (diameter: 4 ± 1 nm), discontinuous nano-rods that grew in various directions, was obtained. In Jc measurements, the Jc of the Ts = 720 °C film in all directions of the applied magnetic field was higher than that of the non-doped SmBCO film. The Jcmin (6.4 MA/cm2) of the former was more than 6 times higher than that (1.0 MA/cm2) of the latter at 40 K, under 3 T. The aforementioned results indicated that the discontinuous BHO nano-rods, which occurred with a high number density, exerted a 3D-like flux pinning at the measurement conditions considered. Moreover, at 4.2 K and under 17 T, a flux pinning force density of 1.6 TN/m3 was realized; this value was comparable to the highest value recorded, to date.
Issues in quantification of registered respiratory gated PET/CT in the lung.
Cuplov, Vesna; Holman, Beverley F; McClelland, Jamie; Modat, Marc; Hutton, Brian F; Thielemans, Kris
2017-12-14
PET/CT quantification of lung tissue is limited by several difficulties: the lung density and local volume changes during respiration, the anatomical mismatch between PET and CT and the relative contributions of tissue, air and blood to the PET signal (the tissue fraction effect). Air fraction correction (AFC) has been shown to improve PET image quantification in the lungs. Methods to correct for the movement and anatomical mismatch involve respiratory gating and image registration techniques. While conventional registration methods only account for spatial mismatch, the Jacobian determinant of the deformable registration transformation field can be used to estimate local volume changes and could therefore potentially be used to correct (i.e. Jacobian Correction, JC) the PET signal for changes in concentration due to local volume changes. This work aims to investigate the relationship between variations in the lung due to respiration, specifically density, tracer concentration and local volume changes. In particular, we study the effect of AFC and JC on PET quantitation after registration of respiratory gated PET/CT patient data. Six patients suffering from lung cancer with solitary pulmonary nodules underwent [Formula: see text]F-FDG PET/cine-CT. The PET data were gated into six respiratory gates using displacement gating based on a real-time position management (RPM) signal and reconstructed with matched gated CT. The PET tracer concentration and tissue density were extracted from registered gated PET and CT images before and after corrections (AFC or JC) and compared to the values from the reference images. Before correction, we observed a linear correlation between the PET tracer concentration values and density. Across all gates and patients, the maximum relative change in PET tracer concentration before (after) AFC was found to be 16.2% (4.1%) and the maximum relative change in tissue density and PET tracer concentration before (after) JC was found to be 17.1% (5.5%) and 16.2% (6.8%) respectively. Overall our results show that both AFC or JC largely explain the observed changes in PET tracer activity over the respiratory cycle. We also speculate that a second order effect is related to change in fluid content but this needs further investigation. Consequently, either AFC or JC is recommended when combining lung PET images from different gates to reduce noise.
Issues in quantification of registered respiratory gated PET/CT in the lung
NASA Astrophysics Data System (ADS)
Cuplov, Vesna; Holman, Beverley F.; McClelland, Jamie; Modat, Marc; Hutton, Brian F.; Thielemans, Kris
2018-01-01
PET/CT quantification of lung tissue is limited by several difficulties: the lung density and local volume changes during respiration, the anatomical mismatch between PET and CT and the relative contributions of tissue, air and blood to the PET signal (the tissue fraction effect). Air fraction correction (AFC) has been shown to improve PET image quantification in the lungs. Methods to correct for the movement and anatomical mismatch involve respiratory gating and image registration techniques. While conventional registration methods only account for spatial mismatch, the Jacobian determinant of the deformable registration transformation field can be used to estimate local volume changes and could therefore potentially be used to correct (i.e. Jacobian Correction, JC) the PET signal for changes in concentration due to local volume changes. This work aims to investigate the relationship between variations in the lung due to respiration, specifically density, tracer concentration and local volume changes. In particular, we study the effect of AFC and JC on PET quantitation after registration of respiratory gated PET/CT patient data. Six patients suffering from lung cancer with solitary pulmonary nodules underwent 18 F-FDG PET/cine-CT. The PET data were gated into six respiratory gates using displacement gating based on a real-time position management (RPM) signal and reconstructed with matched gated CT. The PET tracer concentration and tissue density were extracted from registered gated PET and CT images before and after corrections (AFC or JC) and compared to the values from the reference images. Before correction, we observed a linear correlation between the PET tracer concentration values and density. Across all gates and patients, the maximum relative change in PET tracer concentration before (after) AFC was found to be 16.2% (4.1%) and the maximum relative change in tissue density and PET tracer concentration before (after) JC was found to be 17.1% (5.5%) and 16.2% (6.8%) respectively. Overall our results show that both AFC or JC largely explain the observed changes in PET tracer activity over the respiratory cycle. We also speculate that a second order effect is related to change in fluid content but this needs further investigation. Consequently, either AFC or JC is recommended when combining lung PET images from different gates to reduce noise.
NASA Astrophysics Data System (ADS)
Haberkorn, N.; Suárez, S.; Pérez, P. D.; Troiani, H.; Granell, P.; Golmar, F.; Lee, Jae-Hun; Moon, S. H.
2017-11-01
We report the influence of crystalline defects introduced by 6 MeV 16O3+ irradiation on the critical current densities Jc and flux creep rates in 1.3 μm thick GdBa2Cu3O7-δ coated conductor produced by co-evaporation. Pristine films with pinning produced mainly by random nanoparticles with diameter close to 50 nm were irradiated with doses between 2 × 1013 cm-2 and 4 × 1014 cm-2. The irradiations were performed with the ion beam perpendicular to the surface of the samples. The Jc and the flux creep rates were analyzed for two magnetic field configurations: magnetic field applied parallel (H║c) and at 45° (H║45°) to the c-axis. The results show that at temperatures below 40 K the in-field Jc dependences can be significantly improved by irradiation. For doses of 1 × 1014 cm-2 the Jc values at μ0H = 5 T are doubled without affecting significantly the Jc at small fields. Analyzing the flux creep rates as function of the temperature in both magnetic field configurations, it can be observed that the irradiation suppresses the peak associated with double-kink relaxation and increases the flux creep rates at intermediate and high temperatures. Under 0.5 T, the flux relaxation for H‖c and H||45° in pristine films presents characteristic glassy exponents μ = 1.63 and μ = 1.45, respectively. For samples irradiated with 1 × 1014 cm-2, these values drop to μ = 1.45 and μ = 1.24, respectively
NASA Astrophysics Data System (ADS)
Togano, Kazumasa; Gao, Zhaoshun; Matsumoto, Akiyoshi; Kumakura, Hiroaki
2013-11-01
We report that the transport critical current density Jc of ex situ powder-in-tube (PIT) processed (Ba, K)Fe2As2 (Ba-122) tapes can be significantly enhanced by applying uniaxial cold pressing at the final stage of deformation. The tapes were prepared by packing high quality precursor powder into a Ag tube, cycles of rolling and intermediate annealing, and pressing followed by the final heat treatment for sintering. The Jc values in applied magnetic fields were increased by almost one order of magnitude compared to the tapes processed without pressing, exceeding 104 A cm-2 at 4.2 K. We achieved the highest Jc (at 4.2 K and 10 T) of 2.1×104 A cm-2 among PIT-processed Fe-based wires and tapes reported so far. The Jc-H curves measured at higher temperatures maintain small field dependence up to around 20 K, suggesting that these tapes are promising for applications at higher temperatures as well as at liquid helium temperature. The microstructure investigations reveal that there are two possible causes of the large Jc enhancement by pressing: one is densification and the other is the change of crack structure. Optimization of processing parameters such as the reduction ratio of rolling and pressing is expected to yield further Jc enhancement.
NASA Astrophysics Data System (ADS)
LeBlanc, M. A. R.; Cameron, Daniel S. M.; LeBlanc, David; Meng, Jinglei
1996-01-01
Hysteresis losses, Wac, in the core of a monolithic coaxial cable carrying an alternating current of fixed amplitude Iac are predicted to trace a valley as a steady bias current Ibias is superimposed on Iac, when (a) the critical current density jc diminishes with increasing magnetic field H, and/or (b) a Meissner current IM or a surface barrier current ISB opposing flux entry play a role. The predicted Ibias,min where the valley minimum occurs and the value of Wac at the minima are displayed for various IM≥0 and ISB≥0 when jc=α (Bean) and jc=α/H (Kim approximation).
Critical current density of TlBa 2Ca 2Cu 3O 9 thin films on MgO (100) in magnetic fields
NASA Astrophysics Data System (ADS)
Piehler, A.; Ströbel, J. P.; Reschauer, N.; Löw, R.; Schönberger, R.; Renk, K. F.; Kraus, M.; Daniel, J.; Saemann-Ischenko, G.
1994-04-01
We report on the critical current density of TlBa 2Ca 2Cu 3O 9 thin films on (100) MgO substrates in magnetic fields. Single- phase and highly c-axis oriented thin films were prepared by laser ablation in combination with thermal evaporation of Tl 2O 3. Scanning electron microscope investigations indicated a flat plate-like microstructure and DC magnetization measurements showed the onset of superconductivity at ∼ 115 K. The critical current density jc was determined from magnetization cycles. Typical values of jc were 9 × 10 5 A/cm 2 at 6 K and 2.5 × 10 5 A/cm 2 at 77 K. In a magnetic field to 1 T applied parallel to the c-axis the critical current densities were 3 × 10 5 A/cm 2 at 6 K and 3 × 10 3 A/cm 2 at 77 K. The decrease of jc at higher magnetic fields is discussed and attributed to the microstructure of the TlBa 2Ca 2Cu 3O 9 thin films.
Development of strong vortex pinning and very high Jc in iron based superconductors
NASA Astrophysics Data System (ADS)
Tarantini, Chiara
2015-03-01
Ba(Fe1-xCox)2 As2 (Ba122) is the most tunable of the Fe-based superconductors (FBS) in terms of its acceptance of high densities of secondary phases capable of acting as effective pinning centers without depressing the properties of the superconducting matrix. It has been demonstrated that self-assembled nanorods made of Ba-Fe-O generate a strong correlated pinning along the c-axis, enhancing the critical current density, Jc, in this direction and reducing the Jc anisotropy. However, when 20% of secondary phases are introduced, the reduction of the cross-section becomes significant, decreasing the low field performance. In order to overcome this issue, artificially introduced pinning centers can be added by multilayer deposition producing an almost isotropic increase of Jc. Moreover, FBS are very sensitive to strain, allowing an important enhancement in the critical temperature, Tc, of the material. It will be shown that strain induced by the substrate can further improve Jc of both single and multilayer films by more than expected because of the Tc increase. The multilayer deposition of Ba122 on CaF2 increases the pinning force density, Fp, by more than 60% compared to a single layer film, reaching a maximum of 84 GN/m3 at 22.5T and 4.2 K, the highest value ever reported in any 122 phase. This work shows that the in-field performance of Ba122 widely exceeds that of Nb3Sn above 10T, attracting attention for possible applications.
Current-induced switching in CoGa/L10 MnGa/(CoGa)/Pt structure with different thicknesses
NASA Astrophysics Data System (ADS)
Ranjbar, R.; Suzuki, K. Z.; Mizukami, S.
2018-06-01
In this paper, we present the results of our study into current-induced spin-orbit torque (SOT) switching in perpendicularly magnetized CoGa/MnGa/Pt trilayers with different thicknesses of MnGa and Pt. The SOT switching was observed for all films that undergo Joule heating. We also investigate SOT switching in the bottom (CoGa)/MnGa/top(CoGa/Pt) films with different top layers. Although both the bottom and top layers contribute to the SOT, the relative magnitudes of the switching current densities JC in the top and bottom layers indicate that the SOT is dominant in the top layer. The JC as a function of thickness is discussed in terms of the magnetic properties and resistivity. Experimental data suggested that the MnGa thickness dependence of JC may originate from the perpendicular magnetic anisotropy thickness product Kueff t value. On the other hand, JC as a function of the Pt thickness shows weak dependence. This may be attributed to the slight change of spin-Hall angle θSH value with different thicknesses of Pt, when we assumed that the SOT switching is primarily due to the spin-Hall effect.
NASA Astrophysics Data System (ADS)
Fujii, Hiroki; Iwanade, Akio; Kawada, Satoshi; Kitaguchi, Hitoshi
2018-01-01
The optimal heat treatment temperature (Topt) at which best performance in the critical current density (Jc) property at 4.2 K is obtained is influenced by the quality or reactivity of the filling powder in ex situ processed MgB2 tapes. Using a controlled fabrication process, the Topt decreases to 705-735 °C, which is lower than previously reported by more than 50 °C. The Topt decrease is effective to suppress both the decomposition of MgB2 and hence the formation of impurities such as MgB4, and the growth of crystallite size which decreases upper critical filed (Hc2). These bring about the Jc improvement and the Jc value at 4.2 K and 10 T reaches 250 A/mm2. The milling process also decreases the critical temperature (Tc) below 30 K. The milled powder is easily contaminated in air and thus, the Jc property of the contaminated tapes degrades severely. The contamination can raise the Topt by more than 50 °C, which is probably due to the increased sintering temperature required against contaminated surface layer around the grains acting as a barrier.
NASA Astrophysics Data System (ADS)
Wang, Guanmei; Raine, Mark J.; Hampshire, Damian P.
2018-02-01
The detrimental effects of grain boundaries have long been considered responsible for the low critical current densities ({J}{{c}}) in high temperature superconductors. In this paper, we apply the quantitative approach used to identify the cause of the ‘weak-link’ grain boundary behaviour in YBa2Cu3O7 (Wang et al 2017 Supercond. Sci Technol. 30 104001), to the Bi2Sr2CaCu2O8 and Bi2Sr2Ca2Cu3O10 materials that we have fabricated. Magnetic and transport measurements are used to characterise the grain and grain boundary properties of micro- and nanocrystalline materials. Magnetisation measurements on all nanocrystalline materials show non-Bean-like behaviour and are consistent with surface pinning. Bi2Sr2CaCu2O8: our microcrystalline material has very low grain boundary resistivity ({ρ }{{GB}}), which is similar to that of the grains ({ρ }{{G}}) such that {ρ }{{GB}}≈ {ρ }{{G}}=2× {10}-5 {{Ω }}{{m}} (assuming a grain boundary thickness (d) of 1 nm) equivalent to an areal resistivity of {ρ }{{G}}=2× {10}-14 {{{Ω }}{{m}}}2. The transport {J}{{c}} values are consistent with well-connected grains and very weak grain boundary pinning. However, unlike low temperature superconductors (LTS) in which decreasing grain size increases the pinning along the grain boundary channels, any increase in pinning produced by making the grains in our Bi2Sr2CaCu2O8 materials nanocrystalline was completely offset by a decrease in the depairing current density of the grain boundaries caused by their high resistivity. We suggest a different approach to increasing {J}{{c}} from that used in LTS materials, namely incorporating additional strong grain and grain boundary pinning sites in microcrystalline materials to produce high {J}{{c}} values. Bi2Sr2Ca2Cu3O10: both our micro- and nanocrystalline samples have {ρ }{{GB}}/{ρ }{{G}} of at least 103. This causes strong suppression of {J}{{c}} across the grain boundaries, which explains the low transport {J}{{c}} values we find experimentally. Our calculations show that low {J}{{c}} in untextured polycrystalline Bi2Sr2Ca2Cu3O10 material is to be expected and the significant effort in the community in texturing samples and removing grain boundaries altogether is well-founded.
Enhancement of Hc2 and Jc by carbon-based chemical doping
NASA Astrophysics Data System (ADS)
Yeoh, W. K.; Dou, S. X.
2007-06-01
In the past 5 years, various kinds of doping of MgB 2, including single elements (metal and non-metal), silicates, various carbon sources, and other compounds have been investigated and reported. Most nanoparticle doping leads to improvement of critical current density, Jc( H), and performance, but some types show a negative effect. In this paper, the effect of carbon doping on Jc and the upper critical field, Hc2, of MgB 2 is reviewed. Carbon substitution effects make two distinguishable contributions to the enhancement of Jc field performance: increase of Hc2 and improvement of flux pinning, both because carbon substitutes for boron in the MgB 2 lattice. Among all the carbon sources so far, nano-SiC has been confirmed to be the most effective dopant to enhance the Jc in magnetic fields and Hc2. An irreversibility field, Hirr, of 10 T has been achieved with nano-SiC doping at 20 K, exceeding Hirr of NbTi at 4.2 K. Besides that, Hc2 of carbon alloyed MgB 2 film has reached the value of 71 T. The significant enhancement in Jc( H) and Hc2 via carbon substitution has provided great potential for practical applications of MgB 2. The dual reaction model proposed by the authors’ group provides a comprehensive understanding of the mechanism of enhancement in Jc and Hc2 by chemical doping. Further improvement in self-field Jc performance while maintaining the already achieved in-field performance remains as a major challenge in the development of MgB 2.
Fabrication of Bi2223 bulks with high critical current properties sintered in Ag tubes
NASA Astrophysics Data System (ADS)
Takeda, Yasuaki; Shimoyama, Jun-ichi; Motoki, Takanori; Kishio, Kohji; Nakashima, Takayoshi; Kagiyama, Tomohiro; Kobayashi, Shin-ichi; Hayashi, Kazuhiko
2017-03-01
Randomly grain oriented Bi2223 sintered bulks are one of the representative superconducting materials having weak-link problem due to very short coherence length particularly along the c-axis, resulting in poor intergrain Jc properties. In our previous studies, sintering and/or post-annealing under moderately reducing atmospheres were found to be effective for improving grain coupling in Bi2223 sintered bulks. Further optimizations of the synthesis process for Bi2223 sintered bulks were attempted in the present study to enhance their intergrain Jc. Effects of applied pressure of uniaxial pressing and sintering conditions on microstructure and superconducting properties have been systematically investigated. The best sample showed intergrain Jc of 2.0 kA cm-2 at 77 K and 8.2 kA cm-2 at 20 K, while its relative density was low ∼65%. These values are quite high as for a randomly oriented sintered bulk of cuprate superconductors.
Phase separation in the t-J model. [in theory of high-temperature superconductors
NASA Technical Reports Server (NTRS)
Emery, V. J.; Lin, H. Q.; Kivelson, S. A.
1990-01-01
A detailed understanding of the motion of 'holes' in an antiferromagnet is of fundamental importance for the theory of high-temperature superconductors. It is shown here that, for the t-J model, dilute holes in an antiferromagnet are unstable against phase separation into a hole-rich and a no-hole phase. When the spin-exchange interaction J exceeds a critical value Jc, the hole-rich phase has no electrons. It is proposed that, for J slightly less than Jc, the hole-rich phase is a low-density superfluid of electron pairs. Phase separation in related models is briefly discussed.
Park, Sook Kyung; Ko, Sang Jin; Paik, Sang Kyoo; Rah, Jong-Cheol; Lee, Kea Joo; Bae, Yong Chul
2018-02-23
To provide information on the glutamatergic synapses on the trigeminal motoneurons, which may be important for understanding the mechanism of control of jaw movements, we investigated the distribution of vesicular glutamate transporter (VGLUT)1-immunopositive (+) and VGLUT2 + axon terminals (boutons) on the rat jaw-closing (JC) and jaw-opening (JO) motoneurons, and their morphological determinants of synaptic strength by retrograde tracing, electron microscopic immunohistochemistry, and quantitative ultrastructural analysis. We found that (1) the large majority of VGLUT + boutons on JC and JO motoneurons were VGLUT2+, (2) the density of VGLUT1 + boutons terminating on JC motoneurons was significantly higher than that on JO motoneurons, (3) the density of VGLUT1 + boutons terminating on non-primary dendrites of JC motoneurons was significantly higher than that on somata or primary dendrites, whereas the density of VGLUT2 + boutons was not significantly different between JC and JO motoneurons and among various compartments of the postsynaptic neurons, and (4) the bouton volume, mitochondrial volume, and active zone area of the VGLUT1 + boutons forming synapses on JC motoneurons were significantly bigger than those of VGLUT2 + boutons. These findings suggest that JC and JO motoneurons receive glutamatergic input primarily from VGLUT2-expressing intrinsic neurons (premotoneurons), and may be controlled differently by neurons in the trigeminal mesencephalic nucleus and by glutamatergic premotoneurons.
NASA Astrophysics Data System (ADS)
Hecher, J.; Ishida, S.; Song, D.; Ogino, H.; Iyo, A.; Eisaki, H.; Nakajima, M.; Kagerbauer, D.; Eisterer, M.
2018-01-01
The phase diagram of iron-based superconductors exhibits structural transitions, electronic nematicity, and magnetic ordering, which are often accompanied by an electronic in-plane anisotropy and a sharp maximum of the superconducting critical current density (Jc) near the phase boundary of the tetragonal and the antiferromagnetic-orthorhombic phase. We utilized scanning Hall-probe microscopy to visualize the Jc of twinned and detwinned Ba (Fe1-xCox) 2As2 (x =5 %-8 % ) crystals to compare the electronic normal state properties with superconducting properties. We find that the electronic in-plane anisotropy continues into the superconducting state. The observed correlation between the electronic and the Jc anisotropy agrees qualitatively with basic models, however, the Jc anisotropy is larger than predicted from the resistivity data. Furthermore, our measurements show that the maximum of Jc at the phase boundary does not vanish when the crystals are detwinned. This shows that twin boundaries are not responsible for the large Jc, suggesting an exotic pinning mechanism.
NASA Astrophysics Data System (ADS)
Ye, ShuJun; Song, Minghui; Matsumoto, Akiyoshi; Togano, Kazumasa; Takeguchi, Masaki; Ohmura, Takahito; Kumakura, Hiroaki
2013-12-01
MgB2 has a superconducting transition temperature (Tc) of 39 K, which is much higher than that for practical metallic superconductors. Thus, it is hoped that MgB2 can not only replace metallic superconductors, but can be used under liquid-helium-free conditions, for example, at temperatures of 10-20 K that can easily be achieved using cryocooling systems. However, to date, the reported critical current density (Jc) for MgB2 wires is not high enough for large-scale applications in liquid-helium-free conditions. In the present study, successful fabrication of high-performance MgB2 superconducting wires was carried out using an internal Mg diffusion (IMD) process, involving a p-dimethylbenzene (C8H10) pre-treatment of carbon-coated B powder with nanometer-sized particles. The resulting wires exhibited the highest ever Jc of 1.2 × 105 A cm-2 at 4.2 K and 10 T, and an engineering critical current density (Je) of about 1 × 104 A cm-2. Not only in 4.2 K, but also in 10 K, the Jc values for the wires fabricated in the present study are in fact higher than that for Nb-Ti wires at 4.2 K for the magnetic fields at which the measurements were carried out. At 20 K and 5 T, the Jc and Je were about 7.6 × 105 A cm-2 and 5.3 × 103 A cm-2, respectively, which are the highest values reported for MgB2 wires to date. The results of a detailed microstructural analysis suggested that the main reason for the superior electrical performance was the high density of the MgB2 layer rather than just the small grain size, and that the critical current could be further increased by suitable control of the microstructure. These high-performance IMD-processed MgB2 wires are thus promising superconductors for applications such as magnetic resonance imaging and maglev trains that can operate under liquid-helium-free conditions.
NASA Astrophysics Data System (ADS)
Dou, S. X.; Soltanian, S.; Horvat, J.; Wang, X. L.; Zhou, S. H.; Ionescu, M.; Liu, H. K.; Munroe, P.; Tomsic, M.
2002-10-01
Doping of MgB2 by nano-SiC and its potential for the improvement of flux pinning were studied for MgB2-x)(SiCx/2 with x=0, 0.2, and 0.3 and for 10 wt % nano-SiC-doped MgB2 samples. Cosubstitution of B by Si and C counterbalanced the effects of single-element doping, decreasing Tc by only 1.5 K, introducing intragrain pinning centers effective at high fields and temperatures, and significantly enhancing Jc and Hirr. Compared to the undoped sample, Jc for the 10 wt % doped sample increased by a factor of 32 at 5 K and 8 T, 42 at 20 K and 5 T, and 14 at 30 K and 2 T. At 20 K and 2 T, the Jc for the doped sample was 2.4 x105 A/cm2, which is comparable to Jc values for the best Ag/Bi-2223 tapes. At 20 K and 4 T, Jc was twice as high as for the best MgB2 thin films and an order of magnitude higher than for the best Fe/MgB2 tapes. The magnetic Jc is consistent with the transport Jc which remains at 20 000 A/cm2 even at 10 T and 5 K for the doped sample, an order of magnitude higher than the undoped one. Because of such high performance, it is anticipated that the future MgB2 conductors will be made using a formula of MgBxSiyCz instead of pure MgB2.
Effect of addition of nanoparticle TiO 2/SiO 2 on the superconducting properties of MgB 2
NASA Astrophysics Data System (ADS)
Zhang, Y.; Zhou, S. H.; Wang, X. L.; Dou, S. X.
2008-09-01
In this paper, bulk MgB 2 was prepared by doping with nanoparticle TiO 2 surface-modified by 5-10% SiO 2. The doping ratio of TiO 2/SiO 2 to MgB 2 was 0, 5, 10, and 15 wt%. The sintering temperature varied from 650 °C to 950 °C. Quantitative X-ray diffraction (XRD) analysis was performed to obtain the lattice constants and the weight fraction of impurities using the Rietveld method. It was found that the critical temperature ( Tc) increases with the lattice constants. The critical current density ( Jc) is affected by the doping ratio and the sintering temperature. The Jc exhibited the highest value at the doping ratio of 10 wt% for 5 K and 20 K and at the doping ratio of 5 wt% for 30 K, when the sintering temperature was fixed at 750 °C. When the doping ratio was fixed at 5 wt%, the samples with the sintering temperature of 750 °C had the best Jc for 5 K and 20 K, while the sample with the sintering temperature of 850 °C exhibited the highest Jc at 30 K.
NASA Astrophysics Data System (ADS)
Liu, Yongchang; Lan, Feng; Ma, Zongqing; Chen, Ning; Li, Huijun; Barua, Shaon; Patel, Dipak; Shahriar, M.; Hossain, Al; Acar, S.; Kim, Jung Ho; Xue Dou, Shi
2015-05-01
High performance MgB2 bulks using carbon-coated amorphous boron as a boron precursor were fabricated by Cu-activated sintering at low temperature (600 °C, below the Mg melting point). Dense nano-MgB2 grains with a high level of homogeneous carbon doping were formed in these MgB2 samples. This type of microstructure can provide a stronger flux pinning force, together with depressed volatility and oxidation of Mg owing to the low-temperature Cu-activated sintering, leading to a significant improvement of critical current density (Jc) in the as-prepared samples. In particular, the value of Jc for the carbon-coated (Mg1.1B2)Cu0.05 sample prepared here is even above 1 × 105 A cm-2 at 20 K, 2 T. The results herein suggest that the combination of low-temperature Cu-activated sintering and employment of carbon-coated amorphous boron as a precursor could be a promising technique for the industrial production of practical MgB2 bulks or wires with excellent Jc, as the carbon-coated amorphous boron powder can be produced commercially at low cost, while the addition of Cu is very convenient and inexpensive.
NASA Astrophysics Data System (ADS)
Yamasaki, Hirofumi; Yamada, Hiroshi
2017-11-01
Temperature dependence of critical current density Jc(H, T) was measured in moderate magnetic fields (H ⊥ film) in two thermally co-evaporated YBa2Cu3O7-δ (YBCO) thin films (A, B) and two YBCO films (C, D) deposited using a pulsed-laser deposition method. All sample films were grown epitaxially with the c-axis perpendicular to the surface of a single-crystalline substrate. Transmission electron microscopy observation revealed that these four films contained a high density of nanoprecipitates with typical sizes of 3.6 - 5.0 nm (A), 5.0 - 7.1 nm (B), 7.0 - 10.1 nm (C) and 8.7 - 14.3 nm (D). Films A and B contained very fine nanoprecipitates, whose typical diameters Dtyp are smaller than double the estimated Ginzburg-Landau coherence length 2ξab at T = 77 K, and exhibited a steep increase of Jc with decreasing temperature. Whereas, film D, which contained relatively large nanoprecipitates (Dtyp > 2ξab at T ≤ 70 K), exhibited a gradual increase in Jc. This led to a remarkable crossing of the Jc(T) curves. The temperature dependence of Jc(H//c) under a fixed magnetic field is approximated by Jc ∼ (1 - T/Tc)m(1 + T/Tc)2 where the index m is larger for films containing finer precipitates; that is, m(A) > m(B) > m(C) > m(D). This means that finer nanoprecipitates generally cause steeper Jc increase at low temperatures, which is the origin of the observed crossing phenomenon. The experimental results are reasonably explained by several theoretical models based on the direct summation of elementary pinning forces fp calculated by core pinning interactions.
Critical current scaling and the pivot-point in Nb3Sn strands
NASA Astrophysics Data System (ADS)
Tsui, Y.; Hampshire, D. P.
2012-05-01
Detailed measurements are provided of the engineering critical current density (Jc) and the index of transition (n-value) of two different types of advanced ITER Nb3Sn superconducting strand for fusion applications. The samples consist of one internal-tin strand (OST) and two bronze-route strands (BEAS I and BEAS II—reacted using different heat treatments). Tests on different sections of these wires show that prior to applying strain, Jc is homogeneous to better than 2% along the length of each strand. Jc data have been characterized as a function of magnetic field (B ≤ 14.5 T), temperature (4.2 K ≤ T ≤ 12 K) and applied axial strain ( - 1% ≤ ɛA ≤ 0.8%). Strain-cycling tests demonstrate that the variable strain Jc data are reversible to better than 2% when the applied axial strain is in the range of - 1% ≤ ɛA ≤ 0.5%. The wires are damaged when the intrinsic strain (ɛI) is ɛI ≥ 0.55% and ɛI ≥ 0.23% for the OST and BEAS strands, respectively. The strain dependences of the normalized Jc for each type of strand are similar to those of prototype strands of similar design measured in 2005 and 2008 to about 2% which makes them candidate strands for a round-robin interlaboratory comparison. The Jc data are described by Durham, ITER and Josephson-junction parameterizations to an accuracy of about 4%. For all of these scaling laws, the percentage difference between the data and the parameterization is larger when Jc is small, caused by high B, T or |ɛI|. The n-values can be described by a modified power law of the form n=1+r{I}_{{c}}^{s}, where r and s are approximately constant and Ic is the critical current. It has long been known that pivot-points (or cross-overs) in Jc occur at high magnetic field and temperature. Changing the magnetic field or temperature from one side of the pivot-point to the other changes the highest Jc sample to the lowest Jc sample and vice versa. The pivot-point follows the B-T phase boundary associated with the upper critical field and is usually attributed to the different tin content profiles and pinning properties of internal-tin and bronze-route strands. We report that the strain dependence of the pivot-point in these strands is quite different from that of the upper critical field and suggest that its origin in optimized high tin content strands is the proximity of the tetragonal Nb3Sn phase, which has low superconducting critical parameters.
NASA Astrophysics Data System (ADS)
Kamitani, A.; Takayama, T.; Tanaka, A.; Ikuno, S.
2010-11-01
The inductive method for measuring the critical current density jC in a high-temperature superconducting (HTS) thin film has been investigated numerically. In order to simulate the method, a non-axisymmetric numerical code has been developed for analyzing the time evolution of the shielding current density. In the code, the governing equation of the shielding current density is spatially discretized with the finite element method and the resulting first-order ordinary differential system is solved by using the 5th-order Runge-Kutta method with an adaptive step-size control algorithm. By using the code, the threshold current IT is evaluated for various positions of a coil. The results of computations show that, near a film edge, the accuracy of the estimating formula for jC is remarkably degraded. Moreover, even the proportional relationship between jC and IT will be lost there. Hence, the critical current density near a film edge cannot be estimated by using the inductive method.
Intrinsic pinning and the critical current scaling of clean epitaxial Fe(Se,Te) thin films
NASA Astrophysics Data System (ADS)
Iida, Kazumasa; Hänisch, Jens; Reich, Elke; Kurth, Fritz; Hühne, Ruben; Schultz, Ludwig; Holzapfel, Bernhard; Ichinose, Ataru; Hanawa, Masafumi; Tsukada, Ichiro; Schulze, Michael; Aswartham, Saicharan; Wurmehl, Sabine; Büchner, Bernd
2013-03-01
We report on the transport properties of clean, epitaxial Fe(Se,Te) thin films prepared on Fe-buffered MgO (001) single crystalline substrates by pulsed laser deposition. Near Tc a steep slope of the upper critical field for H||ab was observed (74.1 T/K), leading to a very short out-of-plane coherence length, ξc(0), of 0.2 nm, yielding 2ξc(0)≈0.4nm. This value is shorter than the interlayer distance (0.605 nm) between the Fe-Se(Te) planes, indicative of modulation of the superconducting order parameter along the c axis. An inverse correlation between the power law exponent N of the electric field-current density(E-J) curve and the critical current density Jc has been observed at 4 K, when the orientation of H was close to the ab plane. These results prove the presence of intrinsic pinning in Fe(Se,Te). A successful scaling of the angular dependent Jc and the corresponding exponent N can be realized by the anisotropic Ginzburg Landau approach with appropriate Γ values 2˜3.5. The temperature dependence of Γ behaves almost identically to that of the penetration depth anisotropy.
Flux pinning and inhomogeneity in magnetic nanoparticle doped MgB2/Fe wires
NASA Astrophysics Data System (ADS)
Novosel, Nikolina; Pajić, Damir; Mustapić, Mislav; Babić, Emil; Shcherbakov, Andrey; Horvat, Joseph; Skoko, Željko; Zadro, Krešo
2010-06-01
The effects of magnetic nanoparticle doping on superconductivity of MgB2/Fe wires have been investigated. Fe2B and SiO2-coated Fe2B particles with average diameters 80 and 150 nm, respectively, were used as dopands. MgB2 wires with different nanoparticle contents (0, 3, 7.5, 12 wt.%) were sintered at temperature 750°C. The magnetoresistivity and critical current density Jc of wires were measured in the temperature range 2-40 K in magnetic field B <= 16 T. Both transport and magnetic Jc were determined. Superconducting transition temperature Tc of doped wires decreases quite rapidly with doping level (~ 0.5 K per wt.%). This results in the reduction of the irreversibility fields Birr(T) and critical current densities Jc(B,T) in doped samples (both at low (5 K) and high temperatures (20 K)). Common scaling of Jc(B,T) curves for doped and undoped wires indicates that the main mechanism of flux pinning is the same in both types of samples. Rather curved Kramer's plots for Jc of doped wires imply considerable inhomogeneity.
NASA Astrophysics Data System (ADS)
Thomas, Syju; Varghese, Neson; Rahul, S.; Devadas, K. M.; Vinod, K.; Syamaprasad, U.
2012-12-01
The effect of bending strain on current carrying capacity of MgB2 multifilamentary wires was studied with 4, 8 and 16 multifilamentary wires. The critical current density (JC) of straight wires and bent wires with 5, 10, and 15 cm diameter was measured. Both annealed & bent and bent & annealed wires were used for measurement. The JC of annealed & bent wires were found to decrease with decrease in bent diameter and the rate of degradation of JC decreased with increasing number of filaments, while bent & annealed wires almost retained its JC at all diameters studied.
Jung, Soon-Gil; Kang, Ji-Hoon; Park, Eunsung; Lee, Sangyun; Lin, Jiunn-Yuan; Chareev, Dmitriy A.; Vasiliev, Alexander N.; Park, Tuson
2015-01-01
We investigate the relation of the critical current density (Jc) and the remarkably increased superconducting transition temperature (Tc) for the FeSe single crystals under pressures up to 2.43 GPa, where the Tc is increased by ~8 K/GPa. The critical current density corresponding to the free flux flow is monotonically enhanced by pressure which is due to the increase in Tc, whereas the depinning critical current density at which the vortex starts to move is more influenced by the pressure-induced magnetic state compared to the increase of Tc. Unlike other high-Tc superconductors, FeSe is not magnetic, but superconducting at ambient pressure. Above a critical pressure where magnetic state is induced and coexists with superconductivity, the depinning Jc abruptly increases even though the increase of the zero-resistivity Tc is negligible, directly indicating that the flux pinning property compared to the Tc enhancement is a more crucial factor for an achievement of a large Jc. In addition, the sharp increase in Jc in the coexisting superconducting phase of FeSe demonstrates that vortices can be effectively trapped by the competing antiferromagnetic order, even though its antagonistic nature against superconductivity is well documented. These results provide new guidance toward technological applications of high-temperature superconductors. PMID:26548444
NASA Astrophysics Data System (ADS)
Khan, Nawazish A.; Qurat-ul-Ain; Firdous, Umber; Shaheryar
2012-02-01
We have successfully synthesized (Bi0.25Cu0.25Li0.25Tl0.25)Ba2Ca2Cu3O10-δ and (Bi0.25Cu0.25Li0.25Tl0.25)Ba2(Ca1.5Be0.5)Cu3O10-δ samples and studied their excess conductivity analyses (fluctuation-induced conductivity) of resistivity data. The main objective of such analyses is to investigate the influence of Be-substitution on the superconductivity parameters at the microscopic level. The width of the 3D-2D Lawrence-Doniach regime is increased with the doping of Be at the Ca sites. The energy required to break apart the Cooper pairs is increased from 0.03 eV to 0.08 eV in Be-doped samples. Using the Ginzburg-Landau number (NG) and GL equations, the thermodynamic critical magnetic field Bc(0), the lower critical field Bc1(0), the upper critical field Bc2(0), the critical current density Jc(0), and penetration depth λp.d are also calculated from these analyses. The values of critical fields [Bc(0) Bc1(0)], Jc(0), and phase relaxation time τϕ are increased whereas the penetration depth λp.d and κ values are suppressed with Be-doping. It is most likely that as a result of the enhancement in the density of the carriers in the (Bi0.25Cu0.25Li0.25Tl0.25)Ba2(Ca1.5Be0.5)Cu3O10-δ sample, this charge density gap is suppressed, which in turn suppresses the pseudo-gap resulting into enhancement of Bc (0), Bc1(0), and Jc(0).
NASA Astrophysics Data System (ADS)
Chudzik, Michael Patrick
The weak-link behavior of grain boundaries in polycrystalline high-T c superconductors adversely affects the current density in these materials. The development of wire technology based on polycrystalline high-Tc materials requires understanding and controlling the development of low-angle grain boundaries in these conductors. The research goal is to comprehensively examine the methodology in fabrication and characterization to understand the structure-transport correlation in YBa2Cu3O 7-x (YBCO) surface-coated conductors. High current density YBCO coated conductors were fabricated and characterized as candidates for second generation high-Tc wire technology. Critical current densities (Jc) greater than 1 x 106 A/cm2 at 77 K and zero magnetic field were obtained using thin films epitaxially grown by metalorganic chemical vapor deposition (MOCVD) and pulsed laser deposition (PLD) on oriented buffer layers. The biaxially textured oxide buffer layers were deposited by ion-beam-assisted deposition (IBAD). The transport properties of coated conductors were evaluated in high magnetic fields for intrinsic and extrinsic flux vortex pinning effects for improved high-field properties. Transport Jc's of these coated conductors at 7 tesla (77 K) were measured at values greater than 105 A/cm 2 with the magnetic field perpendicular to the YBCO c-axis (B⊥ c) in both MOCVD and PLD derived conductors. The Jc's in B || c orientation fell an order of magnitude lower at 7 tesla to values near 10 4 A/cm2 due to decreased intrinsic flux pinning. The critical current densities as a function of grain boundary misorientation were found to deviate from the general trend determined for single grain boundary junctions, due to the mosaic structure, which allows meandering current flow. Extensive parametric investigations of relevant thin film growth techniques were utilized to establish growth-property relationships that led to optimized fabrication of high-Tc conductors. The work contained in this dissertation successfully addresses the challenge in engineering low-angle grain boundary polycrystalline conductors for high-current high-field applications and develops a structure-property correlation, which is essential for advancing this technology.
NASA Astrophysics Data System (ADS)
Favreau, Peter; Gapud, Albert A.; Moraes, Sunhee; Delong, Lance; Reyes, Arneil P.; Thompson, James R.; Christen, David K.
2010-03-01
The interaction of two different ordering schemes -- charge density waves (CDWs) and superconductivity -- is studied in high-quality samples of NbSe2, particularly in the motion of magnetic flux quanta. More specifically, the study is on the effect of ``switching off'' the CDW phase -- effected by doping with Ta -- on the magnetic-field H dependence of: (i) the Lorentz-force-driven free flux flow (FFF) resistivity ρf associated with the ordered motion of vortices, and (ii) critical current density Jc. FFF is achieved for the first time in this material. The field dependence of ρf deviates from traditional Bardeen-Stephen flux flow and is more consistent with effects of flux core size as predicted by Kogan and Zelezhina. However, the suppression of CDW's seems to have no significant effect on these properties. On the other hand, Jc(H) shows a surprising double peak for the CDW-suppressed sample --contrary to previous studies in which the Jc peak was shown to disappear. Possible mechanisms are discussed.
NASA Astrophysics Data System (ADS)
Hänisch, J.; Iida, K.; Kurth, F.; Thersleff, T.; Trommler, S.; Reich, E.; Hühne, R.; Schultz, L.; Holzapfel, B.
2014-01-01
The anisotropy of the critical current density Jc depends in general on both the properties of the flux lines (such as line tension, coherence length and penetration depth) and the properties of the defects (such as density, shape, orientation etc.). Whereas the Jc anisotropy in microstructurally clean films can be scaled to an effective magnetic field containing the Ginzburg-Landau anisotropy term, it is in general not possible (or only in a limited field range) for samples containing extended defects. Here, the Jc anisotropy of a Co-doped BaFe2As2 sample with 45° [001] tilt grain boundaries (GBs), i.e. grain boundaries created by 45° in-plane rotated grains, as well as extended Fe particles is investigated. This microstructure leads to c-axis correlated pinning, both due to the GBs and the Fe particles and manifests in a c-axis peak in the Jc anisotropy at low magnetic fields and a deviation from the anisotropic Ginzburg-Landau scaling at higher fields. Strong pinning at ellipsoidal extended defects, i.e. the Fe particles, is discussed, and the full Jc anisotropy is fitted successfully with the vortex path model. The results are compared to a sample without GBs and Fe particles. 45° GBs seem to be good pinning centers rather than detrimental to current flow.
High-temperature change of the creep rate in YBa2Cu3O7-δ films with different pinning landscapes
NASA Astrophysics Data System (ADS)
Haberkorn, N.; Miura, M.; Baca, J.; Maiorov, B.; Usov, I.; Dowden, P.; Foltyn, S. R.; Holesinger, T. G.; Willis, J. O.; Marken, K. R.; Izumi, T.; Shiohara, Y.; Civale, L.
2012-05-01
Magnetic relaxation measurements in YBa2Cu3O7-δ (YBCO) films at intermediate and high temperatures show that the collective vortex creep based on the elastic motion of the vortex lattice has a crossover to fast creep that significantly reduces the superconducting critical current density (Jc). This crossover occurs at temperatures much lower than the irreversibility field line. We study the influence of different kinds of crystalline defects, such as nanorods, twin boundaries, and nanoparticles, on the high-temperature vortex phase diagram of YBCO films. We found that the magnetization relaxation data is a fundamental tool to understand the pinning at high temperatures. The results indicate that high Jc values are directly associated with small creep rates. Based on the analysis of the depinning temperature in films with columnar defects, our results indicate that the size of the defects is the relevant parameter that determines thermal depinning at high temperatures. Also, the extension of the collective creep regime depends on the density of the pinning centers.
High field superconducting properties of Ba(Fe1-xCox)2As2 thin films
NASA Astrophysics Data System (ADS)
Hänisch, Jens; Iida, Kazumasa; Kurth, Fritz; Reich, Elke; Tarantini, Chiara; Jaroszynski, Jan; Förster, Tobias; Fuchs, Günther; Hühne, Ruben; Grinenko, Vadim; Schultz, Ludwig; Holzapfel, Bernhard
2015-11-01
In general, the critical current density, Jc, of type II superconductors and its anisotropy with respect to magnetic field orientation is determined by intrinsic and extrinsic properties. The Fe-based superconductors of the ‘122’ family with their moderate electronic anisotropies and high yet accessible critical fields (Hc2 and Hirr) are a good model system to study this interplay. In this paper, we explore the vortex matter of optimally Co-doped BaFe2As2 thin films with extended planar and c-axis correlated defects. The temperature and angular dependence of the upper critical field is well explained by a two-band model in the clean limit. The dirty band scenario, however, cannot be ruled out completely. Above the irreversibility field, the flux motion is thermally activated, where the activation energy U0 is going to zero at the extrapolated zero-kelvin Hirr value. The anisotropy of the critical current density Jc is both influenced by the Hc2 anisotropy (and therefore by multi-band effects) as well as the extended planar and columnar defects present in the sample.
NASA Astrophysics Data System (ADS)
Khajehvand, Milad; Sepehrband, Panthea
2018-07-01
The jump-to-contact (JC) phenomenon for (111)-oriented surfaces in aluminum at room temperature is studied via molecular dynamics simulations. The effect of crystallographic misorientation and interfacial distance on the JC behavior and distribution of the resultant defects at the interface is investigated. The effect of misorientation on the critical distance for JC is found to be negligible. However, when JC occurs, different distribution of defects is observed for various misorientation angles. The density of defects is shown to be a function of interfacial distance for low misorientation angles, but independent of it for misorientation angles of ∼30 ± 10°.
Strong pinning regimes explored with large-scale Ginzburg-Landau simulations
NASA Astrophysics Data System (ADS)
Willa, Roland; Koshelev, Alexei E.
Improving the current-carrying capability of superconductors requires a deep understanding of vortex pinning. Within the theory of (3D) strong pinning an ideal vortex lattice is weakly deformed by a low density np of strong defects. In this limit the critical current jc is expected to grow linearly with np and to decrease with the field B according to B-α with α 0 . 5 . In the small-field limit the (1D) strong pinning theory of isolated vortices predicts jc np0 . 5 , independent of B. We explore strong pinning by low defect densities using time-dependent Ginzburg-Landau simulations. Our numerical results suggest the existence of a wide regime, where the lattice order is destroyed and yet interactions between vortices are important. In particular, for large defects we found an extended range of power-law decay of jc (B) with α 0 . 3 , smaller than predicted. This regime requires the development of new analytical models. Exploring the behavior of jc for various defect densities and sizes, we will establish pinning regimes and applicability limits of the conventional theory. This work is supported by the U.S. Department of Energy, Office of Science, Materials Sciences and Engineering Division. R. W. acknowledges support from the Swiss National Science Foundation through the SNSF Early Postdoc Mobility Fellowship.
Effect of charcoal doping on the superconducting properties of MgB 2 bulk
NASA Astrophysics Data System (ADS)
Kim, N. K.; Tan, K. S.; Jun, B.-H.; Park, H. W.; Joo, J.; Kim, C.-J.
2008-09-01
The effect of charcoal doping on the superconducting properties of in situ processed MgB 2 bulk samples was investigated. To understand the size effect of the dopant the charcoal powder was attrition milled for 1 h, 3 h and 6 h using ZrO 2 balls. The milled charcoal powders were mixed with magnesium and boron powders to a nominal composition of Mg(B 0.975C 0.025) 2. The Mg(B 0.975C 0.025) 2 compacts were heat-treated at 900 °C for 0.5 h in flowing Ar atmosphere. Magnetic susceptibility for the samples showed that the superconducting transition temperature ( Tc) decreased as the size of the charcoal powder decreased. The critical current density ( Jc) of Mg(B 0.975C 0.025) 2 prepared using large size charcoal powder was lower than that of the undoped MgB 2. However, a crossover of Jc value was observed at high magnetic fields of about 4 T in Mg(B 0.975C 0.025) 2 prepared using small size charcoal powder. Carbon diffusion into the boron site was easier and gave the Jc increase effect when the small size charcoal was used as a dopant.
NASA Astrophysics Data System (ADS)
Trommler, S.; Hänisch, J.; Matias, V.; Hühne, R.; Reich, E.; Iida, K.; Haindl, S.; Schultz, L.; Holzapfel, B.
2012-08-01
Optimized, biaxially textured BaFe1.8Co0.2As2 thin films with an in-plane alignment of 1.7° have been realized on high-quality IBAD-textured MgO-coated technical substrates utilizing additional Fe buffer layers. High critical current densities (Jc) were achieved, comparable to films on single crystalline MgO (Jc ≥ 1 MA cm-2 at 4 K, self-field). Transmission electron microscopy investigations reveal a small number of c-axis correlated defects introduced by the MgO template. The effect of these defects on the Jc anisotropy was determined in angular-dependent electronic transport measurements.
NASA Astrophysics Data System (ADS)
Sun, Y.; Tsuchiya, Y.; Yamada, T.; Taen, T.; Pyon, S.; Shi, Z. X.; Tamegai, T.
2014-09-01
We reported a detailed study of Fe1+yTe0.6Se0.4 single crystals annealed in the atmosphere of chalcogens (O2, S, Se, Te). After annealing with appropriate amount of chalcogens, Fe1+yTe0.6Se0.4 single crystals show Tc higher than 14 K with a sharp transition width ∼1 K. Critical current density Jc for the annealed crystals reach a very high value ∼2-4 × 105 A/cm2 under zero field, and is also robust under applied field at low temperatures. Magneto-optical imaging reveal that the Jc is homogeneously distributed in the annealed crystals and isotropic in the ab-plane. Our results show that annealing in the atmosphere of chalcogens can successfully induce bulk superconductivity in Fe1+yTe0.6Se0.4.
Transport across nanogaps using self-consistent boundary conditions
NASA Astrophysics Data System (ADS)
Biswas, D.; Kumar, R.
2012-06-01
Charge particle transport across nanogaps is studied theoretically within the Schrodinger-Poisson mean field framework. The determination of self-consistent boundary conditions across the gap forms the central theme in order to allow for realistic interface potentials (such as metal-vacuum) which are smooth at the boundary and do not abruptly assume a constant value at the interface. It is shown that a semiclassical expansion of the transmitted wavefunction leads to approximate but self consistent boundary conditions without assuming any specific form of the potential beyond the gap. Neglecting the exchange and correlation potentials, the quantum Child-Langmuir law is investigated. It is shown that at zero injection energy, the quantum limiting current density (Jc) is found to obey the local scaling law Jc ~ Vgα/D5-2α with the gap separation D and voltage Vg. The exponent α > 1.1 with α → 3/2 in the classical regime of small de Broglie wavelengths.
NASA Astrophysics Data System (ADS)
Mihajlović, G.; Mosendz, O.; Wan, L.; Smith, N.; Choi, Y.; Wang, Y.; Katine, J. A.
2016-11-01
We introduce a differential planar Hall effect method that enables the experimental study of spin orbit torque switching of in-plane magnetized free layers in a simple Hall bar device geometry. Using this method, we study the Pt thickness dependence of switching currents and show that they decrease monotonically down to the minimum experimental thickness of ˜5 nm, while the critical current and power densities are very weakly thickness dependent, exhibiting the minimum values of Jc0 = 1.1 × 108 A/cm2 and ρJc0 2=0.6 ×1012 W/cm 3 at this minimum thickness. Our results suggest that a significant reduction of the critical parameters could be achieved by optimizing the free layer magnetics, which makes this technology a viable candidate for fast, high endurance and low-error rate applications such as cache memories.
NASA Astrophysics Data System (ADS)
Miura, M.; Maiorov, B.; Baily, S. A.; Haberkorn, N.; Willis, J. O.; Marken, K.; Izumi, T.; Shiohara, Y.; Civale, L.
2011-05-01
We study the field (H) and temperature (T) dependence of the critical current density (Jc) and irreversibility field (Hirr) at different field orientations in Y0.77Gd0.23Ba2Cu3Oy with randomly distributed BaZrO3 nanoparticles (YGdBCO+BZO) and YBa2Cu3Oy (YBCO) films. Both MOD films have large RE2Cu2O5 (225) nanoparticles (˜80 nm in diameter) and a high density of twin boundaries (TB). In addition, YGdBCO+BZO films have a high density of BZO nanoparticles (˜25 nm in diameter). At high temperatures (T > 40 K), the superconducting properties, such as Jc, Hirr, and flux creep rates, are greatly affected by the BZO nanoparticles, while at low temperatures the superconducting properties of both the YBCO and YGdBCO+BZO films show similar field and temperature dependencies. In particular, while the Jc of YBCO films follow a power-law dependence (∝H-α) at all measured T, this dependence is only followed at low T for YGdBCO+BZO films. As a function of T, the YGdBCO+BZO film shows Jc(T,0.01T)~[1-(T/Tc)2]n with n ˜ 1.24 ± 0.05, which points to “δTc pinning.” We analyze the role of different types of defects in the different temperature regimes and find that the strong pinning of the BZO nanoparticles yields a higher Hirr and improved Jc along the c axis and at intermediate orientations at high T. The mixed pinning landscapes due to the presence of disorder of various dimensionalities have an important role in the improvement of in-field properties.
Flux-pinning and inhomogeneity in MgB 2 /Fe wires
NASA Astrophysics Data System (ADS)
Husnjak, O.; Babić, E.; Kušević, I.; Wang, X. L.; Soltanian, S.; Dou, S. X.
2007-08-01
Transport critical current densities Jc and irreversibility fields B of undoped and nanoparticle doped (10 wt% SiC) Fe-sheathed MgB 2 wires were measured from 2 to 40 K in magnetic field B≤16 T. For the best segments of wires (≤1 cm) both the magnitude and field variations of Jc and the pinning force density Fp=JcB depend only on the magnitude of B, hence the strength of flux-pinning. B of doped wire for T≤30 K is ˜1.4 times larger than that of undoped and reaches that of NbTi (10 T at 4.2 K) already at 20 K. Accordingly, its high-field Jcs and Fps are large, typically three times larger than the best literature results, and are limited by the porosity and inhomogeneity of the superconducting cores in present-day MgB 2 wires.
Flux pinning in nanoparticle doped MgB 2/Cu tapes
NASA Astrophysics Data System (ADS)
Babić, E.; Kušević, I.; Husnjak, O.; Soltanian, S.; Wang, X. L.; Dou, S. X.
2007-09-01
The irreversibility fields Birr and critical current densities Jc of undoped and Si and SiC nanoparticle doped (5, 10 and 20 wt%) MgB2 tapes were measured in the temperature (T) range 2-38 K and in magnetic fields B ⩽ 16 T. Whereas Birr of undoped tapes varies smoothly with T, those of doped tapes show a change in slope around a crossover field Bcr which increases with nanoparticle content and also depends on their type. This indicates matching effect in vortex pinning, probably associated with Mg2Si nanoprecipitates formed during heat treatment. Indeed, Birr of doped tapes was enhanced in respect to that of undoped one with the highest enhancement for Birr ≈ Bcr, but the enhancement remained high ≈1.4 even for Birr ≫ Bcr (low temperatures). The variations of Jc and the pinning force density Fp = JcB with B and T support the above findings.
NASA Astrophysics Data System (ADS)
Li, Xiao-Fen; Kochat, Mehdi; Majkic, Goran; Selvamanickam, Venkat
2016-08-01
In this paper the authors succeeded in measuring the critical current density ({J}{{c}}) of multifilament-coated conductors (CCs) with thin filaments as low as 0.25 mm using the scanning hall probe microscope (SHPM) technique. A new iterative method of data analysis is developed to make the calculation of {J}{{c}} for thin filaments possible, even without a very small scan distance. The authors also discussed in detail the advantage and limitation of the iterative method using both simulation and experiment results. The results of the new method correspond well with the traditional fast Fourier transform method where this is still applicable. However, the new method is applicable for the filamentized CCs in much wider measurement conditions such as with thin filament and a large scan distance, thus overcoming the barrier for application of the SHPM technique on {J}{{c}} measurement of long filamentized CCs with narrow filaments.
High field superconducting properties of Ba(Fe1−xCox)2As2 thin films
Hänisch, Jens; Iida, Kazumasa; Kurth, Fritz; Reich, Elke; Tarantini, Chiara; Jaroszynski, Jan; Förster, Tobias; Fuchs, Günther; Hühne, Ruben; Grinenko, Vadim; Schultz, Ludwig; Holzapfel, Bernhard
2015-01-01
In general, the critical current density, Jc, of type II superconductors and its anisotropy with respect to magnetic field orientation is determined by intrinsic and extrinsic properties. The Fe-based superconductors of the ‘122’ family with their moderate electronic anisotropies and high yet accessible critical fields (Hc2 and Hirr) are a good model system to study this interplay. In this paper, we explore the vortex matter of optimally Co-doped BaFe2As2 thin films with extended planar and c-axis correlated defects. The temperature and angular dependence of the upper critical field is well explained by a two-band model in the clean limit. The dirty band scenario, however, cannot be ruled out completely. Above the irreversibility field, the flux motion is thermally activated, where the activation energy U0 is going to zero at the extrapolated zero-kelvin Hirr value. The anisotropy of the critical current density Jc is both influenced by the Hc2 anisotropy (and therefore by multi-band effects) as well as the extended planar and columnar defects present in the sample. PMID:26612567
Flux pinning in yttrium barium copper oxide coated conductors
NASA Astrophysics Data System (ADS)
Chen, Zhijun
High quality high-temperature-superconducting YBa2Cu 3O7-x (YBCO) films for industrial applications demand very high critical current densities Jc, which can only be achieved by strong three-dimensional (3D) pinning with deliberately introduced nano-precipitates. The purpose of this thesis is to provide an in-depth understanding of the 3D pinning in such YBCO films. In pulsed laser deposition (PLD) prepared YBCO films, a high density of anti-phase boundaries and stacking faults were found to be effective pinning defects for improving Jc in small fields. However, their failure to improve Jc at high fields shows that such naturally generated defects are not strong 3D pinning centers. A demonstration of strong 3D pinning was found in a metal organic chemical vapor deposition (MOCVD) grown YBCO coated conductor (CC) with a high density of (Y,Sm)2O3 nano-precipitates. We observed a significantly enhanced irreversibility field Hirr which, like other superconducting properties was independent of thickness, due to strong vortex-pin interactions. The advantage of 3D pinning was further illustrated by a bi-layer metalorganic deposition (MOD) grown YBCO CC with different 3D pinning structures in each layer. The Jc anisotropy of the bilayer was found to be the thickness-weighted sum of the anisotropy of the two individual layers, demonstrating an applicable way to tune the Jcanisotropy. Moreover, extensive low temperature and high magnetic field evaluations performed on an MOCVD CC with dense 3D (Y,Sm) 2O3 nano-precipitate pinning centers showed that its strong vortex pinning at 77 K correlated well to strong performance at 4.2 K too. YBCO films with quantitatively controlled artificial Y2O 3 nano-precipitates were also grown by PLD, and characterized over wide temperature and field ranges. Their Jc was found to be determined by the vortex pinning mediated by thermal fluctuation effects. In weak thermal-fluctuation situations Jc increased with decreasing effective precipitate spacing Lc. In other situations, Jc depends on both Lc and the size and elementary pinning strength of the nano-precipitates. In summary, this thesis presents detailed pinning studies on several differently grown YBCO films. Our results identify the optimum pinning structures in YBCO films and provide a systematic guidance for optimizing vortex pinning.
Matras, M. R.; Jiang, J.; Larbalestier, D. C.; Hellstrom, E. E.
2016-01-01
Overpressure (OP) processing increases the critical current density (JC) of Bi2Sr2CaCu2Ox (2212) round wires by shrinking the surrounding Ag matrix around the 2212 filaments, driving them close to full density and greatly increasing the 2212 grain connectivity. Indeed densification is vital for attaining the highest JC. Here, we investigate the time and temperature dependence of the wire densification. We find that the wire diameter decreases by 3.8 ± 0.3 % after full heat treatment at 50 atm and 100 atm OP. At 50 atm OP pressure, the filaments start densifying above 700 °C and reach a 3.30 ± 0.07 % smaller diameter after 2 h at 820 °C, which is below the melting point of 2212 powder. The densification is homogeneous and does not change the filament shape before melting. The growth of non-superconducting phases is observed at 820 °C, suggesting that time should be minimized at high temperature prior to melting the 2212 powder. Study of an open-ended 2.2 m long wire sample shows that full densification and the high OP JC (JC varies by about 3.1 times over the 2.2 m long wire) is reached about 1 m from the open ends, thus showing that coil-length wires can be protected from leaky seals by adding at least 1 m of sacrificial wire at each end. PMID:28479675
Improving magnetic properties of MgB2 bulk superconductors by synthetic engine oil treatment
NASA Astrophysics Data System (ADS)
Taylan Koparan, E.; Savaskan, B.; Yanmaz, E.
2016-08-01
The present study focuses on the effects of standby time of the MgB2 samples immersed in synthetic engine oil on the critical current density (Jc(H)), magnetic field dependence of the pinning force density fp(b) and Tc performances of MgB2 bulk superconductors. Synthetic engine oil was used as a product which is cheap and a rich carbon source. Manufactured MgB2 pellet samples were immersed at different standby time of 30 min, 120 min, 300 min and 1440 min in synthetic engine oil after the first heating process. Finally, MgB2 samples immersed in synthetic engine oil were sintered at 1000 °C and kept for 15 min in Ar atmosphere. The critical current density of all of MgB2 samples immersed at different standby time in engine oil in whole field range was better than that of the pure MgB2 sample because of the number of the pinning centers. The MgB2 sample immersed at 300 min standby time in synthetic engine oil has the best performance compared to other samples. The Jc value for the pure sample is 2.0 × 103 A/cm2, whereas for the MgB2 sample immersed at 300 min standby time in engine oil the Jc is enhanced to 4.8 × 103A/cm2 at 5 K and 3 T. The superconducting transition temperature (Tc) did not change with the increasing standby time of the samples in synthetic engine oil at all. The best diamagnetic property was obtained from the sample which kept in synthetic engine oil for 300 min. Synthetic engine oil treatment results in remarkable improvement of the critical current density and pinning force performances of MgB2 superconductors. It was found that all MgB2 samples have a different pinning property at different measuring temperatures. Using synthetic engine oil as a product which is cheap and a rich carbon source in MgB2 bulk superconductors makes MgB2 samples immersed in synthetic engine oil a good candidate for industrial applications.
NASA Astrophysics Data System (ADS)
Oota, A.; Matsui, H.; Funakura, M.; Iwaya, J.; Maeda, J.
1993-07-01
A process of combined rolling and uniaxial pressing with intermediate sintering steps for fabrication of screen-printed (Bi,Pb)2Sr2Ca2Cu3O(x) thick films sandwiched between Ag substrates yields c-axis-oriented microstructures with a high critical current density (Jc) of 1.5 x 10 exp 4 A/sq cm (77 K, 0 T) and 9.0 x 10 exp 4 A/sq cm (23 K, 0 T). The measured Jc anisotropy at 77 K, as a function of the angle Theta between B and c axis, is pronounced. An increase in B sharpens a peak at Theta = 90 deg in the Jc vs Theta curve, together with enhancement of the anisotropy ratio. In high fields above 0.5 T, the half-height angular width of the peak approaches an average misalignment angle between the grains with increasing B.
Highly textured oxypnictide superconducting thin films on metal substrates
NASA Astrophysics Data System (ADS)
Iida, Kazumasa; Kurth, Fritz; Chihara, Masashi; Sumiya, Naoki; Grinenko, Vadim; Ichinose, Ataru; Tsukada, Ichiro; Hänisch, Jens; Matias, Vladimir; Hatano, Takafumi; Holzapfel, Bernhard; Ikuta, Hiroshi
2014-10-01
Highly textured NdFeAs(O,F) thin films have been grown on ion beam assisted deposition-MgO/Y2O3/Hastelloy substrates by molecular beam epitaxy. The oxypnictide coated conductors showed a superconducting transition temperature (Tc) of 43 K with a self-field critical current density (Jc) of 7.0 × 10 4 A / cm 2 at 5 K, more than 20 times higher than powder-in-tube processed SmFeAs(O,F) wires. Albeit higher Tc as well as better crystalline quality than Co-doped BaFe2As2 coated conductors, in-field Jc of NdFeAs(O,F) was lower than that of Co-doped BaFe2As2. These results suggest that grain boundaries in oxypnictides reduce Jc significantly compared to that in Co-doped BaFe2As2 and, hence biaxial texture is necessary for high Jc.
Augmentation de la densité de courant critique par dopage de YBCO texturé au BaSnO3
NASA Astrophysics Data System (ADS)
Lepropre, M.; Monot, I.; Delamare, M. P.; Hervieu, M.; Simon, Ch.; Provost, J.; Desgardin, G.; Raveau, B.
1994-11-01
We have performed critical current density measurements (DC current) on melt textured YBaCuO doped with BaSnO3 which exhibits transport values at 77 K as high as 7.1 × 10^4 A cm^{-2} in zero field and 1.1 × 10^4 A cm^{-2} at 20 T. A systematic study of this ceramic has been carried out using SEM and HREM observations in correlation with J_c measurements. A textured microstructure is observed containing numerous green phase inclusions (size leq 10 μm) as well as a few numbers of BaSnO3 inclusions (size < 1 μm). It has been found that transport J_c data are distributed over a wide range (2.5 × 10^3-7.1 × 10^4 A cm^{-2}). Nevertheless, magnetic J_c measurements suggest that cracks of the order of several microns may appear in some regions of the material leading to a dramatic decrease of transport J_c for the corresponding sample. On the other hand, HREM observations demonstrate that extended defects cannot be considered as the major factor for vortex pinning in textured 123 material. The presence or the absence of inhomogeneity at the nanoscale does not seem to influence the critical current density. Finally, it has been determined that pinning can be ascribed to lamellar microstructure rather than to BaSnO3 inclusions. Nous avons mesuré la densité de courant critique de transport (courant continu) J_c, dans une céramique texturée YBaCuO dopée au BaSnO3. Elle présente des valeurs de J_c (77 K) de 7,1 × 10^4 A cm^{-2} en champ magnétique nul et de 1.1 × 10^4 A cm^{-2} sous 20 T. Une étude systématique de cette céramique a été entreprise. La microstructure et la nanostructure observées respectivement en microscopie électronique à balayage SEM et en microscopie à haute résolution HREM ont été corrélées avec les mesures de J_c. On observe dans cette céramique une microstructure texturée contenant de nombreuses inclusions de phase verte (taille leq 10 μm) et un très faible nombre d'inclusions de BaSnO3 (taille < 1 μm). Les valeurs de J_c de transport se révèlent être assez dispersées (2,5 × 10^3 à 7,1 × 10^4 A cm^{-2}). Des mesures de J_c par méthode magnétique ont été effectuées. Le résultat de ces mesures suggère la présence de microfissures dans certaines régions du matériau causant alors une chute dramatique du J_c de transport dans l'échantillon correspondant. D'autre part, les observations HREM démontrent que les défauts étendus recensés ne peuvent pas être tenus pour principaux responsables du piégeage des vortex dans ce type de matériau. L'éventuelle inhomogénéité à l'échelle nanostructurale ne semble pas influencer la densité de courant critique. Le piégeage serait donc principalement gouverné par la microstructure lamellaire et non par la présence d'inclusions de BaSnO3.
Effect of dc field on ac-loss peak in a commercial Bi:2223/Ag tape
NASA Astrophysics Data System (ADS)
Öztürk, Ali; Düzgün, İbrahim; Çelebi, Selahattin
2017-12-01
Measurements of the ac susceptibility in a commercial Bi:2223/Ag tape for some different ac magnetic field amplitudes, Hac, in the presence of bias magnetic field Hdc directed along Hac are reported. It is found that the peak values of the imaginary component of ac susceptibility χ″max versus Hac trace a valley for the orientation where applied field Ha perpendicular to wide face of the tape total. We note that the observation of the valley depends on various parameters such as field dependence parameter n in the critical current density, in the simple power law expression jc = α(T)/Bn, choice of the bias field Hdc together with selected ac field amplitudes Hac, and dimension and geometry of sample studied. Our calculations based on critical state model with jc = α(1 - T/Tcm)p/Bn using the fitting parameters of n = 0.25, p = 2.2, Tcm = 108 K gives quite good results to compare the experimental and calculated curves.
Low temperature properties of spin filter NbN/GdN/NbN Josephson junctions
NASA Astrophysics Data System (ADS)
Massarotti, D.; Caruso, R.; Pal, A.; Rotoli, G.; Longobardi, L.; Pepe, G. P.; Blamire, M. G.; Tafuri, F.
2017-02-01
A ferromagnetic Josephson junction (JJ) represents a special class of hybrid system where different ordered phases meet and generate novel physics. In this work we report on the transport measurements of underdamped ferromagnetic NbN/GdN/NbN JJs at low temperatures. In these junctions the ferromagnetic insulator gadolinium nitride barrier generates spin-filtering properties and a dominant second harmonic component in the current-phase relation. These features make spin filter junctions quite interesting also in terms of fundamental studies on phase dynamics and dissipation. We discuss the fingerprints of spin filter JJs, through complementary transport measurements, and their implications on the phase dynamics, through standard measurements of switching current distributions. NbN/GdN/NbN JJs, where spin filter properties can be controllably tuned along with the critical current density (Jc), turn to be a very relevant term of reference to understand phase dynamics and dissipation in an enlarged class of JJs, not necessarily falling in the standard tunnel limit characterized by low Jc values.
NASA Astrophysics Data System (ADS)
Araki, Takeshi; Yamagiwa, Katsuya; Hirabayashi, Izumi; Suzuki, Katsumi; Tanaka, Shoji
2001-07-01
Ultrahigh-Jc YBa2Cu3O7-x (YBCO) films have been successfully fabricated by the metalorganic deposition method using a trifluoroacetate coating solution which is prepared by a newly developed purification technique, the solvent-into-gel (SIG) method. The prepared pure coating solution has less than 0.25% impurities and has a wide flexibility in process conditions to obtain high-Jc YBCO film. Using this feature, we have successfully formed 50 mm diameter YBCO films, which have a critical current density over 10 MA cm-2 (77 K, 0 T) on LaAlO3 single crystalline substrates.
Hirano, Y; Kiyama, S; Koguchi, H; Sakakita, H
2014-02-01
Spontaneous self-focusing of ion beam with high current density (Jc ∼ 2 mA/cm(2), Ib ∼ 65 mA) in low energy region (∼150 eV) is observed in a hydrogen ion beam extracted from an ordinary bucket type ion source with three electrodes having concave shape (acceleration, deceleration, and grounded electrodes). The focusing appears abruptly in the beam energy region over ∼135-150 eV, and the Jc jumps up from 0.7 to 2 mA/cm(2). Simultaneously a strong electron flow also appears in the beam region. The electron flow has almost the same current density. Probably these electrons compensate the ion space charge and suppress the beam divergence.
Critical current density, vortex dynamics, and phase diagram of single-crystal FeSe
NASA Astrophysics Data System (ADS)
Sun, Yue; Pyon, Sunseng; Tamegai, Tsuyoshi; Kobayashi, Ryo; Watashige, Tatsuya; Kasahara, Shigeru; Matsuda, Yuji; Shibauchi, Takasada
2015-10-01
We present a comprehensive study of the vortex pinning and dynamics in a high-quality FeSe single crystal which is free from doping-introduced inhomogeneities and charged quasiparticle scattering because of its innate superconductivity. The critical current density Jc is found to be almost isotropic and reaches a value of ˜3 ×104 A /cm2 at 2 K (self-field) for both H ∥c and a b . The normalized magnetic relaxation rate S (=∣d ln M /d ln t ∣ ) shows a temperature-insensitive plateau behavior in the intermediate temperature range with a relatively high creep rate (S ˜ 0.02 under zero field), which is interpreted in the framework of the collective creep theory. A crossover from the elastic to plastic creep is observed, while the fishtail effect is absent for both H ∥c and a b . Based on this observation, the origin of the fishtail effect is also discussed. Combining the results of Jc and S , the vortex motion in the FeSe single crystal is found to be dominated by sparse, strong pointlike pinning from nanometer-sized defects or imperfections. The weak collective pinning is also observed and proved in the form of large bundles. Besides, the vortex phase diagram of FeSe is also constructed and discussed.
Modeling AC ripple currents in HTS coated conductors by integral equations
NASA Astrophysics Data System (ADS)
Grilli, Francesco; Xu, Zhihan
2016-12-01
In several HTS applications, the superconducting tapes experience the simultaneous presence of DC and AC excitations. For example in high-current DC cables, where the transport current is not perfectly constant, but it exhibits some ripples at different frequencies introduced by the rectification process (AC-DC conversion). These ripples give rise to dissipation, whose magnitude and possible influence on the device's cooling requirements need to be evaluated. Here we report a study of the AC losses in a HTS coated conductor subjected to DC currents and AC ripples simultaneously. The modeling approach is based on an integral equation method for thin superconductors: the superconducting tape is modeled as a 1-D object with a non-linear resistivity, which includes the dependence of the critical current density Jc on the magnetic field. The model, implemented in a commercial finite-element program, runs very fast (the simulation of one AC cycle typically takes a few seconds on standard desktop workstation): this allows simulating a large number of cycles and estimating when the AC ripple losses stabilize to a constant value. The model is used to study the influence of the flux creep power index n on the stabilization speed and on the AC loss values, as well as the effect of using a field-dependent Jc instead of a constant one. The simulations confirm that the dissipation level should not be a practical concern in HTS DC cables. At the same time, however, they reveal a strong dependence of the results upon the power index n and the form of Jc , which spurs the question whether the power-law is the most suitable description of the superconductor's electrical behavior for this kind of analysis.
Origin of hydrogen-inclusion-induced critical current deviation in Nb/AlOx/Al/Nb Josephson junctions
NASA Astrophysics Data System (ADS)
Hinode, Kenji; Satoh, Tetsuro; Nagasawa, Shuichi; Hidaka, Mutsuo
2010-04-01
We investigated the mechanisms that change the critical current density (Jc) of Nb/AlOx/Al/Nb Josephson junctions due to the inclusion of hydrogen in the Nb electrodes. Our investigations were performed according to three aspects: the superconductivity change, the change in thickness of the barrier layer, and the change in the barrier height due to the electronic effect. The results are as follows: (a) the hydrogen-inclusion-accompanied changes in the superconductivity parameters, such as the junction gap voltage, were much less than those of the critical current density, (b) the effect of hydrogen inclusion on Jc varied depending on the electrodes, i.e., the upper electrode above the barrier layer was the most affected, (c) the junctions with increased Ics due to hydrogen exclusion showed the identical amount of decrease in the junction resistance measured at room temperature, and (d) the hydrogen exclusion from the junction electrodes had no influence on the Nb/Al/AlOx/Al/Nb junctions, which had an extra Al layer. Based on these results we conclude that the Jc change is mainly caused by the change in junction resistance. A one order of magnitude smaller effect is caused by the superconductivity change. We believe the Jc change is caused by a Nb work function increase due to the hydrogen inclusion, resulting in an increase in barrier height.
NASA Astrophysics Data System (ADS)
Kim, Moon-Jo; Jeong, Hye-Jin; Park, Ju-Won; Hong, Sung-Tae; Han, Heung Nam
2018-01-01
An empirical expression describing the electroplastic deformation behavior is suggested based on the Johnson-Cook (JC) model by adding several functions to consider both thermal and athermal electric current effects. Tensile deformation behaviors are carried out for an AZ31 magnesium alloy and an Al-Mg-Si alloy under pulsed electric current at various current densities with a fixed duration of electric current. To describe the flow curves under electric current, a modified JC model is proposed to take the electric current effect into account. Phenomenological descriptions of the adopted parameters in the equation are made. The modified JC model suggested in the present study is capable of describing the tensile deformation behaviors under pulsed electric current reasonably well.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dhavale Ashavai, Pashupati Dhakal, Anatolii A Polyanskii, Gianluigi Ciovati
We present the results of from DC magnetization and penetration depth measurements of cylindrical bulk large-grain (LG) and fine-grain (FG) niobium samples used for the fabrication of superconducting radio frequency (SRF) cavities. The surface treatment consisted of electropolishing and low temperature baking as they are typically applied to SRF cavities. The magnetization data were fitted using a modified critical state model. The critical current density Jc and pinning force Fp are calculated from the magnetization data and their temperature dependence and field dependence are presented. The LG samples have lower critical current density and pinning force density compared to FGmore » samples which implies a lower flux trapping efficiency. This effect may explain the lower values of residual resistance often observed in LG cavities than FG cavities.« less
NASA Astrophysics Data System (ADS)
Gautam, Bibek; Sebastian, Mary Ann; Chen, Shihong; Shi, Jack; Haugan, Timothy; Xing, Zhongwen; Zhang, Wenrui; Huang, Jijie; Wang, Haiyan; Osofsky, Mike; Prestigiacomo, Joseph; Wu, Judy Z.
2017-07-01
An elastic strain model was applied to evaluate the rigidity of the c-axis aligned one-dimensional artificial pinning centers (1D-APCs) in YBa2Cu3O7-δ matrix films. Higher rigidity was predicted for BaZrO3 1D-APCs than that of the BaHfO3 1D-APCs. This suggests a secondary APC doping of Y2O3 in the 1D-APC/YBa2Cu3O7-δ nanocomposite films would generate a stronger perturbation to the c-axis alignment of the BaHfO3 1D-APCs and therefore a more isotropic magnetic vortex pinning landscape. In order to experimentally confirm this, we have made a comparative study of the critical current density Jc (H, θ, T) of 2 vol.% BaZrO3 + 3 vol.%Y2O3 and 2 vol.%BaHfO3 + 3 vol.%Y2O3 double-doped (DD) YBa2Cu3O7-δ films deposited at their optimal growth conditions. A much enhanced isotropic pinning was observed in the BaHfO3 DD samples. For example, at 65 K and 9.0 T, the variation of the Jc across the entire θ range from θ=0 (H//c) to θ=90 degree (H//ab) is less than 18% for BaHfO3 DD films, in contrast to about 100% for the BaZrO3 DD counterpart. In addition, lower α values from the Jc(H) ˜ H-α fitting were observed in the BaHfO3 DD films in a large θ range away from the H//c-axis. Since the two samples have comparable Jc values at H//c-axis, the improved isotropic pinning in BaHfO3 DD films confirms the theoretically predicted higher tunability of the BaHfO3 1D-APCs in APC/YBa2Cu3O7-δ nanocomposite films.
NASA Technical Reports Server (NTRS)
Fu, C.-C.; Yeh, N.-C.; Samoilov, A. V.; Vakili, K.; Li, Y.; Vasquez, R. P.
1999-01-01
The effect of spin-polarized quasiparticle currents on the critical current density (J-c) of cuprate superconductors is studied in perovskite F-I-S heterostructures as a function of insulator thickness and of underlying magnetic materials. A pulsed current technique is employed to minimize extraneous Joule heating on the superconductor. At temperatures near T-c, F-I-S samples with insulator thicknesses\\1e2nm show precipitous decrease in J_c as current injection (I_m) is increased. In contrast, J_c in a controlled sample with a substituted non-magnetic material (N-I-S) exhibit no dependence on I_m. Similarly, a F-I-S sample with a 10 mn insulating barrier also show little J_c effect versus I_m. At low temperatures with I_m = 0, significant suppression of J-c is observed only in the thin barrier F-I-S samples, although T_c and the normal-state resistivity of all samples are comparable. These phenomena can be attributed to the Cooper pair breaking induced by externally-injected and internally-reflected spin-polarized quasiparticle currents. We estimate an order of magnitude range for the spin diffusion length of 100 nm to 100\\ mum.
High current densities above 100 K in the high-temperature superconductor HgBa2CaCu2O6+δ
NASA Astrophysics Data System (ADS)
Krusin-Elbaum, L.; Tsuei, C. C.; Gupta, A.
1995-02-01
THE recent discovery1,2 of a family of mercury-based copper oxide superconductors having transition temperatures1-3 above 130 K is of considerable technological interest. But the viability of high-temperature superconductors for many applications will ultimately depend on the size of the current density, Jc, that they are able to support, not only at high temperatures, but also in high magnetic fields. For the cuprate superconductors, and in particular for Hg-based materials, the combination of high transition temperature1-3 and large mass anisotropy implies that the transport properties will be intrinsically limited by large thermal fluctuations and short superconducting coherence lengths4. Here we report that high-quality c-axis-oriented epitaxial films of the compound HgBa2CaCu6O6+δ (Hg-1212; ref. 5) can support large in-plane current densities at temperatures higher than has been achieved for other superconductors. In low magnetic fields oriented normal to the film surface, we find Jc>~107 A cm-2 at 5 K and Jc~ 105 A cm-2 at 110 K, at least an order of magnitude larger than for Bi- or Tl-based films6-11. For in-plane magnetic fields, the critical current (~108 A cm-2) is close to the theoretical limit even at high fields, indicative of strong intrinsic pinning in this compound.
Jatropha curcas: from biodiesel generation to medicinal applications.
Paulillo, Luis Cesar; Mo, ChengLin; Isaacson, Janalee; Lessa, Luciene; Lopes, Edjacy; Romero-Suarez, Sandra; Brotto, Leticia; Abreu, Eduardo; Gutheil, William; Brotto, Marco
2012-12-01
Jatropha curcas (JC) is a multipurpose perennial plant that belongs to the Euphorbiaceae family and is native to arid and semiarid tropical regions worldwide. It has many attributes and considerable potential for renewable energy, fish and livestock feeding. Despite its rich application as a renewable source and for animal feeding, JC has barely been explored for its medicinal potential. Here we review several patents related to JC that show it has been underused for medicinal purposes. For example, only one invention disclosure to date utilizes JC, combined with three other plants, in a preparation for wound healing. Motivated by support from the Brazilian funding agencies and anecdotal accounts in Brazil of the medicinal value of JC, we performed a series of pilot studies that demonstrate that JC is able to protect skeletal muscle cells in vitro against the deleterious effects of ethanol. We were able to determine that JC's effects are mediated by the up regulation of HSP60, a critical mitochondrial heat shock related protein that is essential for intracellular REDOX regulation. Given the fact that ethanol myopathy accounts for more than 50% of all cases of myopathy worldwide, we hope that our studies will sparkle new interest from the scientific community to explore the medicinal properties of Jatropha curcas, including the development of new patents leading to new drugs and new targets for the treatment of muscle diseases and other human diseases.
NASA Astrophysics Data System (ADS)
Welp, Ulrich; Leroux, M.; Kihlstrom, K. J.; Kwok, W.-K.; Koshelev, A. E.; Miller, D. J.; Rupich, M. W.; Fleshler, S.; Malozemoff, A. P.; Kayani, A.
2015-03-01
We report on magnetization and transport measurements of the critical current density, Jc, of commercial 2G YBCO coated conductors before and after proton irradiation. The samples were irradiated along the c-axis with 4 MeV protons. Proton irradiation produces a mixed pinning landscape composed of pre-existing rare earth particles and a uniform distribution of irradiation induced nm-sized defects. This pinning landscape strongly reduces the suppression of Jc in magnetic fields resulting in a doubling of Jc in a field of ~ 4T. The irradiation dose-dependence of Jc is characterized by a temperature and field dependent sweat spot that at 5 K and 6 T occurs around 20x1016 p/cm2. Large-scale time dependent Ginzburg-Landau simulations yield a good description of our results. This work supported by the Center for Emergent Superconductivity, an Energy Frontier Research Center funded by the U.S. D.O.E., Office of Science, Office of Basic Energy Sciences (KK, ML, AEK) and by the D.O.E, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357 (UW, WKK).
Boehler, T; Schaeff, B; Hornberg, I; Waibel, B; Mohrmann, M
2009-01-01
By the end of the year 2007, pediatric hospitals in Baden-Württemberg had assigned themselves to one of three levels of perinatal care according to a checklist of the German Federal Joint Committee (F-JC) effective since January 1st, 2006. The Medical Service of Statutory Health Insurance had been assigned to prove the plausibility of that self-assessment according to quality criteria for clinical care of term and preterm newborn infants concordated by the F-JC. Between November 2007 and October 2008 31 providers were audited. Observations were documented in a checklist, reviewed and evaluated by expert auditors. For that purpose, quality criteria given by the F-JC were grouped into 7 quality categories which were weighted according to their practical relevance. In addition, a graded numeric system of evaluation was used for comparative analysis (absolute and relative benchmarking values). 3 of 23 providers fulfilled the quality criteria of the F-JC for PNC level 1 (highest level of care), 6 of 23 fulfilled them in part, and 14 of 23 did not fulfill them as judged by the auditors. Criteria for PNC level 2 were "fulfilled in part" by 2 of 6 providers and "not fulfilled" by 4. Both providers of perinatal special care ("level 3") fulfilled the quality criteria for "level 3" completely. There was no linear correlation between absolute or relative benchmarking values and assessment by expert auditors. If the criteria of the F-JC were interpreted very strictly, it would be difficult to guarantee comprehensive regional delivery of care in the state of Baden-Württemberg at the level formally requested by the F-JC for PNCs.
Costa, Helen P S; Oliveira, Jose T A; Sousa, Daniele O B; Morais, Janne K S; Moreno, Frederico B; Monteiro-Moreira, Ana Cristina O; Viegas, Ricardo A; Vasconcelos, Ilka M
2014-01-01
Jatropha curcas seed cake is a low-value by-product resulting from biodiesel production. The seed cake is highly toxic, but it has great potential for biotechnology applications as it is a repository of biomolecules that could be important in agriculture, medicine, and industry. To explore this potential, a novel trypsin inhibitor called JcTI-I was purified by fractionation of the crude extract with trichloroacetic acid (2.5%, v/v) followed by affinity chromatography (Trypsin-Sepharose 4B) and molecular exclusion (Sephacryl S-200). Non-reducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration showed that JcTI-I has approximately 20.0~kDa. Mass spectrometry analysis revealed that the intact molecular mass of JcTI-I is 10.252~kDa. Moreover, JcTI-I is a glycoprotein with 6.4% (m/m) carbohydrates, pI of 6.6, N-terminal sequence similarity around 60% to plant albumins and high stability to heat, pH, and salinity. JcTI-I presented antibacterial activity against the human pathogenic bacteria Salmonella enterica subspecies enterica serovar choleraesuis and Staphylococcus aureus, with minimum inhibitory concentration less than 5~μg/mL. Furthermore, JcTI-I did have inhibitory activity against the serine proteases from the tested bacteria. Otherwise, no hemolytic activity of human erythrocytes and signs of acute toxicity to mice were observed for JcTI-I. The results demonstrate the benefits of J. curcas seed cake as a source of trypsin inhibitor with potential for biotechnological application as a new antimicrobial agent against human pathogenic bacteria.
Costa, Helen P. S.; Oliveira, Jose T. A.; Sousa, Daniele O. B.; Morais, Janne K. S.; Moreno, Frederico B.; Monteiro-Moreira, Ana Cristina O.; Viegas, Ricardo A.; Vasconcelos, Ilka M.
2014-01-01
Jatropha curcas seed cake is a low-value by-product resulting from biodiesel production. The seed cake is highly toxic, but it has great potential for biotechnology applications as it is a repository of biomolecules that could be important in agriculture, medicine, and industry. To explore this potential, a novel trypsin inhibitor called JcTI-I was purified by fractionation of the crude extract with trichloroacetic acid (2.5%, v/v) followed by affinity chromatography (Trypsin-Sepharose 4B) and molecular exclusion (Sephacryl S-200). Non-reducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration showed that JcTI-I has approximately 20.0~kDa. Mass spectrometry analysis revealed that the intact molecular mass of JcTI-I is 10.252~kDa. Moreover, JcTI-I is a glycoprotein with 6.4% (m/m) carbohydrates, pI of 6.6, N-terminal sequence similarity around 60% to plant albumins and high stability to heat, pH, and salinity. JcTI-I presented antibacterial activity against the human pathogenic bacteria Salmonella enterica subspecies enterica serovar choleraesuis and Staphylococcus aureus, with minimum inhibitory concentration less than 5~μg/mL. Furthermore, JcTI-I did have inhibitory activity against the serine proteases from the tested bacteria. Otherwise, no hemolytic activity of human erythrocytes and signs of acute toxicity to mice were observed for JcTI-I. The results demonstrate the benefits of J. curcas seed cake as a source of trypsin inhibitor with potential for biotechnological application as a new antimicrobial agent against human pathogenic bacteria. PMID:24523715
Burkholderia monticola sp. nov., isolated from mountain soil.
Baek, Inwoo; Seo, Boram; Lee, Imchang; Yi, Hana; Chun, Jongsik
2015-02-01
An ivory/yellow, Gram-stain-negative, short-rod-shaped, aerobic bacterial strain, designated JC2948(T), was isolated from a soil sample taken from Gwanak Mountain, Republic of Korea. 16S rRNA gene sequence analysis indicated that strain JC2948(T) belongs to the genus Burkholderia. The test strain showed highest sequence similarities to Burkholderia tropica LMG 22274(T) (97.6 %), Burkholderia acidipaludis NBRC 101816(T) (97.5 %), Burkholderia tuberum LMG 21444(T) (97.5 %), Burkholderia sprentiae LMG 27175(T) (97.4 %), Burkholderia terricola LMG 20594(T) (97.3 %) and Burkholderia diazotrophica LMG 26031(T) (97.1 %). Based on average nucleotide identity (ANI) values, the new isolate represents a novel genomic species as it shows less than 90 % ANI values with other closely related species. Also, other phylosiological and biochemical comparisons allowed the phenotypic differentiation of strain JC2948(T) from other members of the genus Burkholderia. Therefore, we suggest that this strain should be classified as the type strain of a novel species of the genus Burkholderia. The name Burkholderia monticola sp. nov. (type strain, JC2948(T) = JCM 19904(T) = KACC 17924(T)) is proposed. © 2015 IUMS.
NASA Astrophysics Data System (ADS)
Hossain, M. S. A.; Motaman, A.; Çiçek, Ö.; Ağıl, H.; Ertekin, E.; Gencer, A.; Wang, X. L.; Dou, S. X.
2012-12-01
The effects of sintering temperature on the lattice parameters, full width at half maximum (FWHM), strain, critical temperature (Tc), critical current density (Jc), irreversibility field (Hirr), upper critical field (Hc2), and resistivity (ρ) of 10 wt.% silicone oil doped MgB2 bulk and wire samples are investigated in state of the art by this article. The a-lattice parameter of the silicone oil doped samples which were sintered at different temperatures was drastically reduced from 3.0864 Å to 3.0745 Å, compared to the un-doped samples, which indicates the substitution of the carbon (C) into the boron sites. It was found that sintered samples at the low temperature of 600 °C shows more lattice distortion by more C-substitution and higher strain, lower Tc, higher impurity scattering, and enhancement of both magnetic Jc and Hc2, compared to those sintered samples at high temperatures. The flux pinning mechanism has been analyzed based on the extended normalized pinning force density fp = Fp/Fp,max scaled with b = B/Bmax. Results show that surface pinning is the dominant pinning mechanism for the doped sample sintered at the low temperature of 600 °C, while point pinning is dominant for the un-doped sample. The powder in tube (PIT) MgB2 wire was also fabricated by using of this liquid doping and found that both transport Jc and n-factor increased which proves this cheap and abundant silicone oil doping can be a good candidate for industrial application.
Robles, A; Ruano, M V; García-Usach, F; Ferrer, J
2012-06-01
A submerged anaerobic MBR demonstration plant with two commercial hollow-fibre ultrafiltration systems (PURON®, Koch Membrane Systems, PUR-PSH31) was operated using municipal wastewater at high levels of mixed liquor total solids (MLTS) (above 22 g L(-1)). A modified flux-step method was applied to assess the critical flux (J(C)) at different gas sparging intensities. The results showed a linear dependency between J(C) and the specific gas demand per unit of membrane area (SGD(m)). J(C) ranged from 12 to 19 LMH at SGD(m) values of between 0.17 and 0.5 Nm(3) h(-1) m(-2), which are quite low in comparison to aerobic MBR. Long-term trials showed that the membranes operated steadily at fluxes close to the estimated J(C), which validates the J(C) obtained by this method. After operating the membrane for almost 2 years at sub-critical levels, no irreversible fouling problems were detected, and therefore, no chemical cleaning was conducted. Copyright © 2012 Elsevier Ltd. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Polat, Ozgur; Ertugrul, Memhet; Thompson, James R
To obtain an engineered surface for deposition of high-Tc superconductors, nanoscale modulations of the surface of the underlying LaMnO3 (LMO) cap layer is a potential source for generating microstructural defects in YBa2Cu3O7- (YBCO) films. These defects may improve the flux-pinning and consequently increase the critical current density, Jc. To provide such nanoscale modulation via a practical and scalable process, tantalum (Ta) and palladium (Pd) nano-islands were deposited using dc-magnetron sputtering on the surface of the cap layer of commercial metal tape templates for second-generation wires. The size and density of these nano-islands can be controlled by changing sputtering conditions suchmore » as the power and deposition time. Compared to the reference sample grown on an untreated LMO cap layer, the YBCO films grown on the LMO cap layers with Ta or Pd nano-islands exhibited improved in-field Jc performance. Atomic Force Microscopy (AFM) and Transmission Electron Microscopy (TEM) were used to assess the evolving size and density of the nano-islands.« less
Characterization of YBa2Cu3O7, including critical current density Jc, by trapped magnetic field
NASA Technical Reports Server (NTRS)
Chen, In-Gann; Liu, Jianxiong; Weinstein, Roy; Lau, Kwong
1992-01-01
Spatial distributions of persistent magnetic field trapped by sintered and melt-textured ceramic-type high-temperature superconductor (HTS) samples have been studied. The trapped field can be reproduced by a model of the current consisting of two components: (1) a surface current Js and (2) a uniform volume current Jv. This Js + Jv model gives a satisfactory account of the spatial distribution of the magnetic field trapped by different types of HTS samples. The magnetic moment can be calculated, based on the Js + Jv model, and the result agrees well with that measured by standard vibrating sample magnetometer (VSM). As a consequence, Jc predicted by VSM methods agrees with Jc predicted from the Js + Jv model. The field mapping method described is also useful to reveal the granular structure of large HTS samples and regions of weak links.
Critical Current Properties in Longitudinal Magnetic Field of YBCO Superconductor with APC
NASA Astrophysics Data System (ADS)
Kido, R.; Kiuchi, M.; Otabe, E. S.; Matsushita, T.; Jha, A. K.; Matsumoto, K.
The critical current density (Jc) properties of the Artificial Pinning Center (APC) introduced YBa2Cu3O7 (YBCO) films in the longitudinal magnetic field were measured. Y2O3 or Y2BaCuO5 (Y211) was introduced as APCs to YBCO, and YBCO films with APC were fabricated on SrTiO3 single crystal substrate. The sizes of Y2O3 and Y211 were 5-10 nm and 10-20 nm, respectively. As a result, Jc enhancement in the longitudinal magnetic field was observed in Y2O3 introduced YBCO films. However, it was not observed in Y211 introduced YBCO films. Therefore, it was considered that Jc properties in the longitudinal magnetic field were affected by introducing of small size APC, and it was necessary that APC does not disturb the current pathway in the superconductor.
NASA Astrophysics Data System (ADS)
Margiani, N. G.; Mumladze, G. A.; Adamia, Z. A.; Kuzanyan, A. S.; Zhghamadze, V. V.
2018-05-01
In this paper, the combined effects of B4C-doping and planetary ball milling on the phase evolution, microstructure and transport properties of Bi1.7Pb0.3Sr2Ca2Cu3Oy(B4C)x HTS with x = 0 ÷ 0.125 were studied through X-ray diffraction (XRD), scanning electron microscopy (SEM), resistivity and critical current density measurements. Obtained results have shown that B4C additive leads to the strong acceleration of high-Tc phase formation and substantial enhancement in Jc. High-energy ball milling seems to produce a more homogeneous distribution of refined doped particles in the (Bi,Pb)-2223 HTS which results in an improved intergranular flux pinning and better self-field Jc performance.
NASA Astrophysics Data System (ADS)
Langhorn, J.; Bi, Y. J.; Abell, J. S.
1996-02-01
Platinum group metal additions made to thick films of YBCO have induced significant improvements in the superconducting properties, in particular critical current densities ( Jc). Values in excess of 7 × 10 3 A cm -2 at 77 K and zero applied field have been measured. Optical and transmission electron microscopy have shown a homogeneous distribution of sub-micron sized, and larger highly anisotropic 211, believed to result from a reaction between Pt and YBCO to create nucleation sites for 211 precipitates. Indirect supporting thermal analysis evidence for this reaction is presented. An increased density of dislocations associated with the {123}/{211} interface suggests that refined 211 precipitates may act as heterogeneous nucleation sites for flux pinning defects. Similar effects have been observed for additions of other platinum group metals (Rh, Pd).
Shaping and reinforcement of melt textured YBa2Cu3O7-δ superconductors
NASA Astrophysics Data System (ADS)
Meslin, S.; Harnois, C.; Chubilleau, C.; Horvath, D.; Grossin, D.; Suddhakar, E. R.; Noudem, J. G.
2006-07-01
From porous Y2BaCuO5 (Y211) with various grain sizes, single domain ceramic composites YBa2Cu3Oy/Y2BaCuO5 have been prepared by combination of the infiltration and top seed growth (ITSG) process. In addition, perforated Y123 has been prepared from Y211 by the ITSG method in order to magnify the specific surface and then increase oxygen diffusion into the core of the material. Magnetic and electrical properties were determined and correlate well with the microstructure of the composites and were compared to the conventional doped or undoped YBa2Cu3Oy (Y123). From magnetic measurements, high critical current densities, Jc, of 86 000 A cm-2 have been measured. Transport Jc values higher than 10 600 A cm-2 are reached at 77 K and 0 T, corresponding to the nominal critical currents of 325 A injected reproducibly through sections less than 3.082 mm2. This confirms the high quality of single domains obtained with a well controlled ITSG process. On the other hand, the perforated samples were reinforced using resin impregnation and the flux mapping has been investigated.
NASA Technical Reports Server (NTRS)
Murakami, Masato; Gotoh, Satoshi; Fujimoto, Hiroyuki; Koshizuka, Naoki; Tanaka, Shoji
1991-01-01
In the Y-Ba-Cu-O system, YBa2Cu3O(x) phase is produced by the following peritectic reaction: Y2BaCuO5 + liquid yields 2YBa2Cu3O(x). Through the control of processing conditions and starting compositions, it becomes possible to fabricate large crystals containing fine Y2BaCuO5(211) inclusions. Such crystals exhibit Jc values exceeding 10000 A/sq cm at 77 K and 1T. Recently, researchers developed a novel process which can control the volume fraction of 211 inclusions. Elimination of 211 inclusions is also possible. In this study, researchers prepared YBaCuO crystals with and without 211 inclusions using the novel process, and compared flux pinning, flux creep and critical currents. Magnetic field dependence of Jc for YBaCuO crystals with and with 211 inclusions is shown. It is clear that fine 211 inclusions can contribute to flux pinning. It was also found that flux creep rate could be reduced by increasing flux pinning force. Critical current density estimates based on the conventional flux pinning theory were in good agreement with experimental results.
NASA Astrophysics Data System (ADS)
Sanfilippo, S.; Sulpice, A.; Bourgault, D.; Villard, C.; Gautier-Picard, P.; Chaud, X.; Beaugnon, E.; Tournier, R.
1998-02-01
Direct transport measurements at 77 K of the critical current density along the c-axis (J_c) and magnetic measurements are performed on the same bulk textured single domain YBaCuO samples with the longest dimension along the c-axis. A strong influence of the Twin Planes (TP) on J_c and on the ab-plane irreversibility line B(T^*) is reported when the field is rotated in the ab-planes perpendicularly to the c-axis. The different unusual behaviors observed for J_c and the B(T^*), depending on the range of temperature and field are explained by the strong influence of these extended correlated defects on the pinning of the flux lines. La densité de courant critique selon l'axe c (J_c) est mesurée à 77 K en transport et par des mesures magnétiques sur les mêmes échantillons texturés monodomaines d'YBaCuO. L'influence des plans de macles (TP) sur J_c et sur la ligne d'irréversibilité B(T^*) est étudiée en faisant tourner le champ dans les plans ab, perpendiculairement à l'axe c. Les résultats montrent que dans ces composés, J_c et B(T^*) sont fortement influencés par le piégeage par les TP. Divers comportements des lignes de flux résultant de l'influence de ces défauts corrélés sont proposés selon les gammes de température et de champ étudiées.
Pinning in high performance MgB2 thin films and bulks: Role of Mg-B-O nano-scale inhomogeneities
NASA Astrophysics Data System (ADS)
Prikhna, Tatiana; Shapovalov, Andrey; Eisterer, Michael; Shaternik, Vladimir; Goldacker, Wilfried; Weber, Harald W.; Moshchil, Viktor; Kozyrev, Artem; Sverdun, Vladimir; Boutko, Viktor; Grechnev, Gennadiy; Gusev, Alexandr; Kovylaev, Valeriy; Shaternik, Anton
2017-02-01
The comparison of nano-crystalline MgB2 oxygen-containing thin film (140 nm) and highly dense bulk materials showed that the critical current density, Jc, depends on the distribution of Mg-B-O nano-scale inhomogeneities. It has been shown that MgB2 bulks with high Jc in low (∼106 A/cm2 in 0-1 T at 10 K) and medium magnetic fields contain MgB0.6-0.8O0.8-0.9 nano-inclusions, where δTc or a combined δTc (dominant) / δl pinning mechanism prevails, while in bulk MgB2 with high Jc in high magnetic fields (Birr(18.5 K) = 15 T, Bc2(0 K) = 42.1 T) MgB1.2-2.7O1.8-2.5 nano-layers are present and δl pinning prevails. The structure of oxygen-containing films with high Jc in low and high magnetic fields (Jc (0 Т) = 1.8 × 107 А/сm2 and Jc (5 Т) = 2 × 106 А/сm2 at 10 К) contains very fine oxygen-enriched Mg-B-O inhomogeneities and δl pinning is realized. The results of DOS calculations in MgB2-xOx cells for x = 0, 0.125, 0.25, 0.5, 1 demonstrate that all compounds are conductors with metal-like behaviour. In the case of ordered oxygen substitution for boron the binding energy, Eb, does not increase sufficiently as compared with that for MgB2, while when oxygen atoms form zigzag chains the calculated Eb is even lower (Eb = -1.15712 Ry).
Development of a fracture toughness test for balloon film
NASA Technical Reports Server (NTRS)
Tielking, John T.
1991-01-01
This paper describes the equipment and test procedures being developed in an ongoing project to measure J(c) for film in a biaxial stress state. The objective of the research is to confirm J(c) as a material property whose value will permit the initiation of film tear growth to be predicted. Results are presented for two polyethylene balloon films, an LDPE and LLDPE, of thickness 0.8 mil.
NASA Astrophysics Data System (ADS)
Prikhna, T. A.; Chaud, X.; Gawalek, W.; Joulain, A.; Rabier, J.; Moshchil, V. E.; Savchuk, Ya. M.; Sergienko, N. V.; Dub, S. N.; Melnikov, V. S.; Habisreuther, T.; Litzkendorf, D.; Bierlich, J.
2008-03-01
The oxygenation of MT-YBCO under isostatic oxygen pressure (up to 16 MPa) at 900-800 °C allowed reduced process time, lower macrocracking, and reduced microcracks. Additionally higher critical currents, trapped fields and mechanical characteristics can be attained. At 77 K thin-walled MT-YBCO had a jc in the ab plane of 85 kA/cm2 at 0 T and higher than 10 kA/cm2 in fields up to 5 T and the irreversibility field was 9.8 T. In the c-direction jc was 34 kA/cm2 in 0 T and higher than 2.5 kA/cm2 in a 10 T field. At 4.9 N-load the micohardness, Hv, was 8.7±0.3 GPa in the ab-plane and 7.6±0.3 GPa in the c-direction. The fracture toughness, K1C, was 2.5±0.1 MPaṡm0.5 (ab-plane) and 2.8±0.24 MPaṡm0.5 (c-direction). The samples with a higher twin density demonstrated a higher jc, especially in applied magnetic field. The twin density correlates with the sizes and distribution of Y211 grains in Y123. The thin-walled ceramics that demonstrated the highest jc contained about 22 twins in 1 μm and were practically free from dislocations and stacking faults. The maximal trapped field of the block of thin-walled ceramic oxygenated at 900-800 °C and 16 MPa was doubled as compared to that oxygenated at low temperature under ambient pressure.
Two Native Americans Speak on Art Values and the Value of Arts
ERIC Educational Resources Information Center
Zastrow, Leona M.
1977-01-01
The personal views of two southwestern Native Americans (an Acoma and a Pima) are presented in this transcript of informal taped interviews re: the value and preservation of traditional American Indian arts. (JC)
Determination of the air w-value in proton beams using ionization chambers with gas flow capability.
Moyers, M F; Vatnitsky, S M; Miller, D W; Slater, J M
2000-10-01
The purpose of this work was to determine the w-value of air for protons using the paired gas method. Several plastic- and magnesium-walled chambers were used with air, synthetic air, nitrogen, and argon flowing gases. Using argon as a reference gas, the w-value of air was measured and ranged from 32.7 to 34.5 J/C for protons with energies encountered in radiotherapy. Using nitrogen as a reference gas, the w-value of air ranged from 35.2 to 35.4 J/C over the same range of proton energies. The w-value was found, at a given energy, to be independent of the ion chamber used. The uncertainty in these measurements was estimated at 5.2% at the 2sigma level. This uncertainty was dominated by the 4.4% uncertainty in the w-value of the reference gas.
Three TFL1 homologues regulate floral initiation in the biofuel plant Jatropha curcas
Li, Chaoqiong; Fu, Qiantang; Niu, Longjian; Luo, Li; Chen, Jianghua; Xu, Zeng-Fu
2017-01-01
Recent research revealed that TERMINAL FLOWER 1 (TFL1) homologues are involved in the critical developmental process of floral initiation in several plant species. In this study, the functions of three putative TFL1 homologues (JcTFL1a, JcTFL1b and JcTFL1c) in the biofuel plant Jatropha curcas were analysed using the transgenic approach. JcTFL1b and JcTFL1c, but not JcTFL1a, could complement the TFL1 function and rescue early flowering and determinate inflorescence phenotype in tfl1-14 Arabidopsis mutant, thus suggesting that JcTFL1b and JcTFL1c may be homologues of TFL1. Transgenic Jatropha overexpressing JcTFL1a, JcTFL1b or JcTFL1c showed late flowering, whereas only JcTFL1b and JcTFL1c overexpression delayed flowering in transgenic Arabidopsis. JcTFL1b-RNAi transgenic Jatropha consistently exhibited moderately early flowering phenotype. JcFT and JcAP1 were significantly downregulated in transgenic Jatropha overexpressing JcTFL1a, JcTFL1b or JcTFL1c, which suggested that the late flowering phenotype of these transgenic Jatropha may result from the repressed expression of JcFT and JcAP1. Our results indicate that these three JcTFL1 genes play redundant roles in repressing flowering in Jatropha. PMID:28225036
The Josephson plasma resonance in Bi2Sr2CaCu2O8 in a tilted field
NASA Astrophysics Data System (ADS)
Bayrakci, S.; Tsui, Ophelia K. C.; Ong, N. P.; Kishio, K.; Watauchi, S.
1999-04-01
The dependence of the Josephson plasma frequency ωp in Bi2Sr2CaCu2O8 on a tilted field H is reported. Measurements over a large range of B and tilt angle θ allow a detailed comparison with a recent calculation by Koshelev. With a slight modification of the model, close agreement is obtained. From the fits, we find values for the in-plane correlation length and the zero-field critical current density Jc0 (4600 A/cm2 at 30 K). An analogy to Bragg diffraction is described, as well as a picture for the fractional-exponent behavior of ωp vs. H
Superconducting properties of nano-sized SiO2 added YBCO thick film on Ag substrate
NASA Astrophysics Data System (ADS)
Almessiere, Munirah Abdullah; Al-Otaibi, Amal lafy; Azzouz, Faten Ben
2017-10-01
The microstructure and the flux pinning capability of SiO2-added YBa2Cu3Oy thick films on Ag substrates were investigated. A series of YBa2Cu3Oy thick films with small amounts (0-0.5 wt%) of nano-sized SiO2 particles (12 nm) was prepared. The thicknesses of the prepared thick films was approximately 100 µm. Phase analysis by x-ray diffraction and microstructure examination by scanning electron microscopy were performed and the critical current density dependence on the applied magnetic field Jc(H) and electrical resistivity ρ(T) were investigated. The magnetic field and temperature dependence of the critical current density (Jc) was calculated from magnetization measurements using Bean's critical state model. The results showed that the addition of a small amount (≤0.02 wt%) of SiO2 was effective in enhancing the critical current densities in the applied magnetic field. The sample with 0.01 wt% of added SiO2 exhibited a superconducting characteristics under an applied magnetic field for a temperature ranging from 10 to 77 K.
Pair-breaking mechanisms in superconductor—normal-metal—superconductor junctions
NASA Astrophysics Data System (ADS)
Yang, H. C.; Finnemore, D. K.
1984-08-01
The critical current density Jc has been measured for superconductor—normal-metal—superconductor (S-N-S) junctions over a wide range of temperature and composition in order to determine the depairing effects of magnetic impurities. Junctions, which are in a sandwich geometry with the N layer typically 600 nm thick, show well-defined diffraction patterns indicating that the junctions are of high quality. Below 4.2 K, the temperature dependence of Jc is found to follow a modified bridge theory based on the work of Makeev et al.
Unusually high critical current of clean P-doped BaFe2As2 single crystalline thin film
NASA Astrophysics Data System (ADS)
Kurth, F.; Tarantini, C.; Grinenko, V.; Hänisch, J.; Jaroszynski, J.; Reich, E.; Mori, Y.; Sakagami, A.; Kawaguchi, T.; Engelmann, J.; Schultz, L.; Holzapfel, B.; Ikuta, H.; Hühne, R.; Iida, K.
2015-02-01
Microstructurally clean, isovalently P-doped BaFe2As2 (Ba-122) single crystalline thin films have been prepared on MgO (001) substrates by molecular beam epitaxy. These films show a superconducting transition temperature (Tc) of over 30 K although P content is around 0.22, which is lower than the optimal one for single crystals (i.e., 0.33). The enhanced Tc at this doping level is attributed to the in-plane tensile strain. The strained film shows high transport self-field critical current densities (Jc) of over 6 MA/cm2 at 4.2 K, which are among the highest for Fe based superconductors (FeSCs). In-field Jc exceeds 0.1 MA/cm2 at μ 0 H = 35 T for H ‖ a b and μ 0 H = 18 T for H ‖ c at 4.2 K, respectively, in spite of moderate upper critical fields compared to other FeSCs with similar Tc. Structural investigations reveal no defects or misoriented grains pointing to strong pinning centers. We relate this unexpected high Jc to a strong enhancement of the vortex core energy at optimal Tc, driven by in-plane strain and doping. These unusually high Jc make P-doped Ba-122 very favorable for high-field magnet applications.
Vortex pinning in artificially layered Ba(Fe,Co)2As2 film
NASA Astrophysics Data System (ADS)
Oh, M. J.; Lee, Jongmin; Seo, Sehun; Yoon, Sejun; Seo, M. S.; Park, S. Y.; Kim, Ho-Sup; Ha, Dong-Woo; Lee, Sanghan; Jo, Youn Jung
2018-06-01
Static high critical current densities (Jc) > 1 MA/cm2 with magnetic field parallel or perpendicular to c-axis were realized in Co-doped/undoped multilayerd BaFe2As2 films. We made a current bridge by FIB to allow precise measurements, and confirmed that the boundary quality using FIB was considerably better than the quality achieved using a laser. The presence of a high in-plane Jc suggested the existence of c-axis correlated vortex pinning centers. To clarify the relationship between the Jc performance and superstructures, we investigated the magnetic flux pinning mechanism using scaling theory of the volume pinning force Fp(H). The Jc(H) curves, Fp/Fp,max vs. h = H/Hirr curves, and parameters p and q depended on the characteristics of the flux pinning mechanism. It was found that the dominant pinning mechanism of Co-doped/undoped multilayerd BaFe2As2 films was Δl-pinning and the inserted undoped BaFe2As2 layers remained non-superconducting. The dominant pin geometry varied when the magnetic field direction changed. It was concluded that the artificially layered BaFe2As2 film is a 3-D superconductor due to its long correlation length compared to the thickness of the non-superconducting layer.
NASA Astrophysics Data System (ADS)
Tan, T. T.; Li, S.; Oh, J. T.; Gao, W.; Liu, H. K.; Dou, S. X.
2001-02-01
It is believed that grain boundaries act as weak links in limiting the critical current density (Jc) of bulk high-Tc superconductors. The weak-link problem can be greatly reduced by elimination or minimization of large-angle grain boundaries. It has been reported that the distribution of the Jc in (Bi, Pb)2Sr2Ca2Cu3O10+x (Bi2223) superconductor tapes presents a parabolic relationship in the transverse cross section of the tapes, with the lowest currents occurring at the centre of the tapes. It was proposed that the Jc distribution is strongly dependent on the local crystallographic orientation distribution of the Bi2223 oxides. However, the local three-dimensional crystallographic orientation distribution of Bi2223 crystals in (Bi, Pb)2Sr2Ca2Cu3O10+x superconductor tapes has not yet been experimentally determined. In this work, the electron backscattered diffraction technique was employed to map the crystallographic orientation distribution, determine the misorientation of grain boundaries and also map the misorientation distribution in Bi2223 superconductor tapes. Through crystallographic orientation mapping, the relationship between the crystallographic orientation distribution, the boundary misorientation distribution and the fabrication parameters may be understood. This can be used to optimize the fabrication processes thus increasing the critical current density in Bi2223 superconductor tapes.
High temperature superconductor materials and applications
NASA Technical Reports Server (NTRS)
Doane, George B., III.; Banks, Curtis; Golben, John
1990-01-01
Research on processing methods leading to a significant enhancement in the critical current densities (Jc) and the critical temperature (Tc) of high temperature superconducting in thin bulk and thin film forms. The fabrication of important devices for NASA unique applications (sensors) is investigated.
Critical current density in (YBa2Cu3O7-δ)1-x-(PrBa2Cu3O7-δ)x melt-textured composites
NASA Astrophysics Data System (ADS)
Opata, Yuri Aparecido; Monteiro, João Frederico Haas Leandro; Jurelo, Alcione Roberto; Siqueira, Ezequiel Costa
2018-06-01
Melt textured (YBa2Cu3O7-δ)1-x-(PrBa2Cu3O7-δ)x composites (x = 0.00 and x = 0.05) were grown using the top seeding method. The effect of the PrBa2Cu3O7-δ phase on the growth process and the modification of the microstructure as well as on the physical properties was analyzed. X-ray analyses indicated that both pure and Pr-doped samples present an orthorhombic superconducting phase. From resistivity measurements for YBa2Cu3O7-δ and (YBa2Cu3O7-δ)0.95-(PrBa2Cu3O7-δ)0.05 samples, the Tcab did not change and was around 90.5 K. However, from magnetic measurements, the superconductivity was observed in critical temperatures TC = 92.9 K and 92.4 K for YBa2Cu3O7-δ and (YBa2Cu3O7-δ)0.95-(PrBa2Cu3O7-δ)0.05 samples, respectively. The YBa2Cu3O7-δ sample showed higher critical current densities than those shown by the (YBa2Cu3O7-δ)0.95-(PrBa2Cu3O7-δ)0.05 sample, with values of JC = 5.85 × 105 A/cm2 and 4.72 × 105 A/cm2, respectively. This paper also discusses the importance of Pr substitution on nano- and micro-meter scales to enhance JC(H).
Enhancement of the in-field Jc of MgB2 via SiCl4 doping
NASA Astrophysics Data System (ADS)
Wang, Xiao-Lin; Dou, S. X.; Hossain, M. S. A.; Cheng, Z. X.; Liao, X. Z.; Ghorbani, S. R.; Yao, Q. W.; Kim, J. H.; Silver, T.
2010-06-01
We present the following results. (1) We introduce a doping source for MgB2 , liquid SiCl4 , which is free of C, to significantly enhance the irreversibility field (Hirr) , the upper critical field (Hc2) , and the critical current density (Jc) with a little reduction in the critical temperature (Tc) . (2) Although Si can not be incorporated into the crystal lattice, a significant reduction in the a -axis lattice parameter was found, to the same extent as for carbon doping. (3) Based on the first-principles calculation, it is found that it is reliable to estimate the C concentration just from the reduction in the a -lattice parameter for C-doped MgB2 polycrystalline samples that are prepared at high sintering temperatures, but not for those prepared at low sintering temperatures. Strain effects and magnesium deficiency might be reasons for the a -lattice reduction in non-C or some of the C-added MgB2 samples. (4) The SiCl4 -doped MgB2 shows much higher Jc with superior field dependence above 20 K compared to undoped MgB2 and MgB2 doped with various carbon sources. (5) We introduce a parameter, RHH (Hc2/Hirr) , which can clearly reflect the degree of flux-pinning enhancement, providing us with guidance for further enhancing Jc . (6) It was found that spatial variation in the charge-carrier mean free path is responsible for the flux-pinning mechanism in the SiCl4 treated MgB2 with large in-field Jc .
New 1201-type (Hg,Se)-superconducting cuprate grown by sol gel and sealed quartz tube synthesis
NASA Astrophysics Data System (ADS)
Kandyel, Elsayed; Elsabawy, Khaled M.
2008-12-01
A new mercury based superconductor (Hg1-ySey)(Sr2-xLax)CuO4+δ (y = 0.25; 0.3 ⩽ x ⩽ 0.7) with a Tc(onset) of 50 K has been synthesized using sol gel process combined with the sealed quartz tube method. X-ray diffraction shows that the (Hg0.75Se0.25)(Sr2-xLax)CuO4+δ phase crystallizes in the tetragonal symmetry (space group P4/mmm) with a ≈ ap ≈ 3.8 Å and c ≈ 8.7 Å and is isostructural with the 94 K superconductor HgBa2CuO4+δ, adopting the so-called 1201-type structure. Both Se and La are necessary for the stabilization of the 1201-type Hg/Sr cuprates. EDX analysis indicated that mercury and selenium have incorporated into the structure with Se/Hg ≈ ⅓. The new high-Tc superconductor, (Hg0.75Se0.25)(Sr1.3La0.7)CuO4+δ, exhibits a current density, Jc, of 1270 KA/cm2 at (5 K and 5 T) which is higher than the estimated Jc value for (Hg,Cr)Sr2CuO4+δ.
Critical current and flux dynamics in Ag-doped FeSe superconductor
NASA Astrophysics Data System (ADS)
Galluzzi, A.; Polichetti, M.; Buchkov, K.; Nazarova, E.; Mancusi, D.; Pace, S.
2017-02-01
The measurements of DC magnetization as a function of the temperature M(T), magnetic field M(H), and time M(t) have been performed in order to compare the superconducting and pinning properties of an undoped FeSe0.94 sample and a silver doped FeSe0.94 + 6 wt% Ag sample. The M(T) curves indicate an improvement of the superconducting critical temperature and a reduction of the non-superconducting phase Fe7Se8 due to the silver doping. This is confirmed by the field and temperature dependent critical current density Jc(H,T) extracted from the superconducting hysteresis loops at different temperatures within the Bean critical state model. Moreover, the combined analysis of the Jc(T) and of the pinning force Fp(H/Hirr) indicate that the pinning mechanisms in both samples can be described in the framework of the collective pinning theory. The U*(T, J) curves show a pinning crossover from an elastic creep regime of intermediate size flux bundles, for low temperatures, to a plastic creep regime at higher temperatures for both the samples. Finally, the vortex hopping attempt time has been evaluated for both samples and the results are comparable with the values reported in the literature for high Tc materials.
Synthesis, anisotropy, and superconducting properties of LiFeAs single crystal
NASA Astrophysics Data System (ADS)
Song, Yoo Jang; Ghim, Jin Soo; Min, Byeong Hun; Kwon, Yong Seung; Jung, Myung Hwa; Rhyee, Jong-Soo
2010-05-01
A LiFeAs single crystal with Tconset˜19.7 K was grown in a sealed tungsten crucible using the Bridgeman method. The electrical resistivity experiments revealed a ratio of room temperature to residual resistivity of approximately 46 and 18 for the in-plane and out-of plane directions, respectively. The estimated anisotropic resistivity, γρ=ρc/ρab, was approximately 3.3 at Tconset. The upper critical fields had large Hc2∥ab and Hc2∥c values of 83.4 T and 72.5 T, respectively, and an anisotropy ratio is γH=Hc2∥ab/Hc2∥c˜1.15. The high upper critical field value and small anisotropy highlight the potential use of LiFeAs in a variety of applications. The calculated critical current density (Jc) from the M-H loop is approximately 103 A/cm2
NASA Astrophysics Data System (ADS)
Jha, Alok K.; Matsumoto, Kaname; Horide, Tomoya; Saini, Shrikant; Mele, Paolo; Ichinose, Ataru; Yoshida, Yutaka; Awaji, Satoshi
2017-09-01
The effect of incorporation of nanoscale Y2BaCuO5 (Y211) inclusions on the vortex pinning properties of YBa2Cu3O7-δ (YBCO or Y123) superconducting thin films is investigated in detail on the basis of variation of critical current density (JC) with applied magnetic field and also with the orientation of the applied magnetic field at two different temperatures: 77 K and 65 K. Surface modified target approach is employed to incorporate nanoscale Y211 inclusions into the superconducting YBCO matrix. The efficiency of Y211 nanoinclusions in reducing the angular anisotropy of critical current density is found to be significant. The observed angular dependence of the critical current density is discussed on the basis of mutually occupied volume by a vortex and spherical and/or planar defect. A dip in JC near the ab-plane is also observed which has been analyzed on the basis of variation of pinning potential corresponding to a spherical (3-D) or planar (2-D) pinning center and has been attributed to a reduced interaction volume of the vortices with a pinning center and competing nature of the potentials due to spherical and planar defects.
Doubling of the Critical Current Density of 2G-YBCO Coated Conductors through proton irradiation
NASA Astrophysics Data System (ADS)
Welp, Ulrich; Jia, Ying; Kwok, Wai-Kwong; Rupich, Marty; Fleshler, Steven; Kayani, Asfghar
2013-03-01
We report on magnetization and transport measurements of the critical current density of commercial 2G YBCO coated conductors before and after proton irradiation. The samples were irradiated along the c-axis with 4 MeV protons to a fluence of 1.5x1016 p/cm2. We find that at temperatures below 50 K, proton irradiation increases Jc by a factor of 2 in low fields and increases up to 2.5 in fields of 7 T. At 77 K, proton irradiation is less effective in enhancing the critical current. Doubling of Jc in fields of several Tesla and at temperatures below 50 K will be highly beneficial for applications of coated conductors in rotating machinery, generators and magnet coils. - Work supported by the US DoE-BES funded Energy Frontier Research Center (YJ), and by Department of Energy, Office of Science, Office of Basic Energy Sciences (UW, WKK), under Contract No. DE-AC02-06CH11357.
NASA Astrophysics Data System (ADS)
Zhou, Qiujiao; Qi, Bing; Huang, Jianjun; Pan, Lizhu; Liu, Ying
2016-04-01
The properties of a helium atmospheric-pressure plasma jet (APPJ) are diagnosed with a dual assisted grounded electrode dielectric barrier discharge device. In the glow discharge, we captured the current waveforms at the positions of the three grounded rings. From the current waveforms, the time delay between the adjacent positions of the rings is employed to calculate the plasma bullet velocity of the helium APPJ. Moreover, the electron density is deduced from a model combining with the time delay and current intensity, which is about 1011 cm-3. In addition, The ion-neutral particles collision frequency in the radial direction is calculated from the current phase difference between two rings, which is on the order of 107 Hz. The results are helpful for understanding the basic properties of APPJs. supported by National Natural Science Foundation of China (No. 11105093), the Technological Project of Shenzhen, China (No. JC201005280485A), and the Planned S&T Program of Shenzhen, China (No. JC201105170703A)
What happens in Josephson junctions at high critical current densities
NASA Astrophysics Data System (ADS)
Massarotti, D.; Stornaiuolo, D.; Lucignano, P.; Caruso, R.; Galletti, L.; Montemurro, D.; Jouault, B.; Campagnano, G.; Arani, H. F.; Longobardi, L.; Parlato, L.; Pepe, G. P.; Rotoli, G.; Tagliacozzo, A.; Lombardi, F.; Tafuri, F.
2017-07-01
The impressive advances in material science and nanotechnology are more and more promoting the use of exotic barriers and/or superconductors, thus paving the way to new families of Josephson junctions. Semiconducting, ferromagnetic, topological insulator and graphene barriers are leading to unconventional and anomalous aspects of the Josephson coupling, which might be useful to respond to some issues on key problems of solid state physics. However, the complexity of the layout and of the competing physical processes occurring in the junctions is posing novel questions on the interpretation of their phenomenology. We classify some significant behaviors of hybrid and unconventional junctions in terms of their first imprinting, i.e., current-voltage curves, and propose a phenomenological approach to describe some features of junctions characterized by relatively high critical current densities Jc. Accurate arguments on the distribution of switching currents will provide quantitative criteria to understand physical processes occurring in high-Jc junctions. These notions are universal and apply to all kinds of junctions.
Composite ceramic superconducting wires for electric motor applications
NASA Astrophysics Data System (ADS)
Halloran, John W.
1990-07-01
Several types of HTSC wire have been produced and two types of HTSC motors are being built. Hundreds of meters of Ag- clad wire were fabricated from YBa2Cu3O(7-x) (Y-123) and Bi2Ca2Sr2Cu3O10 (BiSCCO). The dc homopolar motor coils are not yet completed, but multiple turns of wire have been wound on the coil bobbins to characterize the superconducting properties of coiled wire. Multifilamentary conductors were fabricated as cables and coils. The sintered polycrystalline wire has self-field critical current densities (Jc) as high as 2800 A/sq cm, but the Jc falls rapidly with magnetic field. To improve Jc, sintered YBCO wire is melt textured with a continuous process which has produced textures wire up to 0.5 meters long with 77K transport Jc above 11, 770 A/sq cm2 in self field and 2100 A/sq cm2 at 1 telsa. The Emerson Electric dc homopolar HTSC motor has been fabricated and run with conventional copper coils. A novel class of potential very powerful superconducting motors have been designed to use trapped flux in melt textures Y-123 as magnet replicas in an new type of permanent magnet motor. The stator element and part of the rotor of the first prototype machine exist, and the HTSC magnet replica segments are being fabricated.
NASA Astrophysics Data System (ADS)
Liu, Linfei; Wang, Wei; Yao, Yanjie; Wu, Xiang; Lu, Saidan; Li, Yijie
2018-05-01
Improvement in the in-filed transport properties of REBa2Cu3O7-δ (RE = rare earth elements, REBCO) coated conductor is needed to meet the performance requirements for various practical applications, which can be accomplished by introducing artificial pinning centers (APCs), such as second phase dopant. However, with increasing dopant level the critical current density Jc at 77 K in zero applied magnetic field decreases. In this paper, in order to improve Jc we propose a seed layer technique. 5 mol% BaHfO3 (BHO) doped Y0.5Gd0.5Ba2Cu3O7-δ (YGBCO) epilayer with an inserted seed layer was grown on CeO2 buffered ion beam assisted deposition MgO (IBAD-MgO) tape by pulsed laser deposition. The effect of the conditions employed to prepare the seed layer, including tape moving speed and chemical composition, on the quality of 5 mol% BHO doped YGBCO epilayer was systematically investigated by X-ray diffraction (XRD) measurements and scanning electron microscopy (SEM) observations. It was found that all the samples with seed layer have higher Jc (77 K, self-field) than the 5 mol% BHO doped YGBCO film without seed layer. The seed layer could inhibit deterioration of the Jc at 77 K and self-filed. Especially, the self-seed layer (5 mol% BHO doped YGBCO seed layer) was more effective in improving the crystal quality, surface morphology and superconducting performance. At 4.2 K, the 5 mol% BHO doped YGBCO film with 4 nm thick self-seed layer had a very high flux pinning force density Fp of 860 GN/m3 for B//c under a 9 T field, and more importantly, the peak of the Fp curve was not observed.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Galstyan, E; Gharahcheshmeh, MH; Delgado, L
We report the microstructural characteristics of high levels of Zr-added REBa2Cu3O7-x (RE = Gd, Y rare earth) coated conductors fabricated by Metal Organic Chemical Vapor Deposition (MOCVD). The enhancements of the lift factor defined as a ratio of the in-field (3 T, B parallel to c-axis) critical current density (J(c)) at 30 K and self-field J(c) at 77 K have been achieved for Zr addition levels of 20 and 25 mol% via optimization of deposition parameters. The presence of strong flux pinning is attributed to the aligned nanocolumns of BaZrO3 and nanoprecipitates embedded in REBa2Cu3O7-x matrix with good crystal quality.more » A high density of BZO nanorods with a typical size 6-8 nm and spacing of 20 nm has been observed. Moreover, the high Zr content was found to induce a high density of intrinsic defects, including stacking faults and dislocations. The correlation between in-field performance along the c-axis and microstructure of (Gd, Y) BCO film with a high level of Zr addition is discussed.« less
NASA Astrophysics Data System (ADS)
Santosh, M.; Naik, S. Pavan Kumar; Koblischka, M. R.
2017-07-01
In the upcoming generation, bulk high temperature superconductors (HTS) will play a crucial and a promising role in numerous industrial applications ranging from Maglev trains to magnetic resonance imaging, etc. Especially, the bulk HTS as permanent magnets are suitable due to the fact that they can trap magnetic fields being several orders of magnitude higher than those of the best hard ferromagnets. The bulk HTS LREBa2Cu3O7-δ (LREBCO or LRE-123, LRE: Y, Gd, etc.,) materials could obtain very powerful compact superconducting super-magnets, which can be operated at the cheaper liquid nitrogen temperature or below due to higher critical temperatures (i.e., ∼90 K). As a result, the new advanced technology can be utilized in a more attractive manner for a variety of technological and medical applications which have the capacity to revolutionize the field. An understanding of the magnetic field dependence of the critical current density (J c(H)) is important to develop better adapted materials. To achieve this goal, a variety of Jc (H) behaviours of bulk LREBCO samples were modelled regarding thermally activated flux motion. In essence, the Jc (H) curves follows a certain criterion where an exponential model is applied. However, to fit the complete Jc (H) curve of the LRE-123 samples an unique model is necessary to explain the behavior at low and high fields. The modelling of the various superconducting materials could be understood in terms of the pinning mechanisms.
Burkholderia megalochromosomata sp. nov., isolated from grassland soil.
Baek, Inwoo; Seo, Boram; Lee, Imchang; Lee, Kihyun; Park, Sang-Cheol; Yi, Hana; Chun, Jongsik
2015-03-01
A Gram-stain negative, rod-shaped, non-spore-forming, obligate aerobic bacterial strain, JC2949(T), was isolated from grassland soil in Gwanak Mountain, Seoul, Republic of Korea. Phylogenetic analysis, based on 16S rRNA sequences, indicated that strain JC2949(T) belongs to the genus Burkholderia, showing highest sequence similarities with Burkholderia grimmiae R27(T) (98.8 %), Burkholderia cordobensis LMG 27620(T) (98.6 %), Burkholderia jiangsuensis MP-1T(T) (98.6 %), Burkholderia zhejiangensis OP-1(T) (98.5 %), Burkholderia humi LMG 22934(T) (97.5 %), Burkholderia terrestris LMG 22937(T) (97.3 %), Burkholderia telluris LMG 22936(T) (97.2 %) and Burkholderia glathei ATCC 29195(T) (97.0 %). The major fatty acids of strain JC2949(T) were C18 : 1ω7c, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. Its predominant polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and an unknown amino phospholipid. The dominant isoprenoid quinone was ubiquinone Q-8. The pairwise average nucleotide identity values between strain JC2949(T) and the genomes of 30 other species of the genus Burkholderia ranged from 73.4-90.4 %, indicating that the isolate is a novel genomic species within this genus. Based on phenotypic and chemotaxonomic comparisons, it is clear that strain JC2949(T) represents a novel species of the genus Burkholderia. We propose the name for this novel species to be Burkholderia megalochromosomata sp. nov. The type strain is JC2949(T) ( = KACC 17925(T) = JCM 19905(T)). © 2015 IUMS.
The influence of white pine blister rust on seed dispersal in whitebark pine
Shawn T. McKinney; Diana F. Tomback
2007-01-01
We tested the hypotheses that white pine blister rust (Cronartium ribicola J.C. Fisch.) damage in whitebark pine (Pinus albicaulis Engelm.) stands leads to reduced (1) seed cone density, (2) predispersal seed survival, and (3) likelihood of Clark's Nutcracker (Nucifraga columbiana (Wilson, 1811)) seed...
Superconducting characteristics in purified tantalum-foils
NASA Astrophysics Data System (ADS)
Hu, Qinghua; Wang, Zhihe
2018-07-01
We have conducted extensive investigations on the electrical transport and magnetization on a purified tantalum foil with extremely sharp resistive transition (transition width ΔTc < 0.02 K) at 0 T and residual resistivity ratio ρ290K/ρ5K= 16.75. Many effects, such as anisotropic field-induced resistive broadening and second peak of the magnetization-hysteresis loop, are observed in the sample. The maximum upper critical field determined by criteria of R/Rn = 0.9 is about 1.08 T rather weak compared to that in cuprate and/or iron-based superconductors. Although the value of upper critical field Hc2(0) and the field dependence of effective pinning energy U show that the flux pinning potential is weaker, the critical current density Jc(2 K, 0 T) = 1.145 × 105 A/cm2 and the effect of second peak indicate that there should be higher collective vortex pinning potential in the tantalum foil. The carriers are dominated by holes with the density n = 6.6 × 1022/cm3.
Ambulatory blood pressure and tubulointerstitial injury in patients with IgA nephropathy
Haruhara, Kotaro; Tsuboi, Nobuo; Koike, Kentaro; Kanzaki, Go; Okabayashi, Yusuke; Miyazaki, Yoichi; Kawamura, Tetsuya; Ogura, Makoto; Yokoo, Takashi
2015-01-01
Background Few studies have been conducted to assess the ambulatory blood pressure (ABP) in IgA nephropathy (IgAN) patients. This study aimed to determine the relationships between ABP and renal histopathological findings assessed using the Oxford classification (OC) and the Japanese classification (JC), which have recently established histopathological criteria for IgAN. Methods This cross-sectional study included biopsy-diagnosed IgAN patients, in whom both a renal biopsy and ABP measurement were performed. The histopathological findings were assessed using the OC and the JC and were analyzed in relation to the ABP. Results A total of 111 IgAN patients were included. The score of interstitial fibrosis and tubular atrophy (T score) using the OC was a significantly associated factor with both the daytime and nighttime ABP values. In contrast, the other histopathological scores, including mesangial hypercellularity, endocapillary hypercellularity and segmental glomerulosclerosis, did not show significant associations with the ABP. The histological grade (H-grade) using the JC, which was based on the sum of injured glomeruli, was associated with the daytime ABP, but not with the nighttime ABP. The associations between the T score using the OC (%) and the daytime and nighttime ABP values were independent of age, gender, renal function, proteinuria and the use of antihypertensive medications, whereas the H-grade using the JC (%) did not show significant associations after adjusting for these clinical parameters. Conclusions These results suggest that the T score using the OC is the most relevant renal histopathological parameter associated with abnormalities of circadian blood pressure in IgAN patients. PMID:26613030
Ambulatory blood pressure and tubulointerstitial injury in patients with IgA nephropathy.
Haruhara, Kotaro; Tsuboi, Nobuo; Koike, Kentaro; Kanzaki, Go; Okabayashi, Yusuke; Miyazaki, Yoichi; Kawamura, Tetsuya; Ogura, Makoto; Yokoo, Takashi
2015-12-01
Few studies have been conducted to assess the ambulatory blood pressure (ABP) in IgA nephropathy (IgAN) patients. This study aimed to determine the relationships between ABP and renal histopathological findings assessed using the Oxford classification (OC) and the Japanese classification (JC), which have recently established histopathological criteria for IgAN. This cross-sectional study included biopsy-diagnosed IgAN patients, in whom both a renal biopsy and ABP measurement were performed. The histopathological findings were assessed using the OC and the JC and were analyzed in relation to the ABP. A total of 111 IgAN patients were included. The score of interstitial fibrosis and tubular atrophy (T score) using the OC was a significantly associated factor with both the daytime and nighttime ABP values. In contrast, the other histopathological scores, including mesangial hypercellularity, endocapillary hypercellularity and segmental glomerulosclerosis, did not show significant associations with the ABP. The histological grade (H-grade) using the JC, which was based on the sum of injured glomeruli, was associated with the daytime ABP, but not with the nighttime ABP. The associations between the T score using the OC (%) and the daytime and nighttime ABP values were independent of age, gender, renal function, proteinuria and the use of antihypertensive medications, whereas the H-grade using the JC (%) did not show significant associations after adjusting for these clinical parameters. These results suggest that the T score using the OC is the most relevant renal histopathological parameter associated with abnormalities of circadian blood pressure in IgAN patients.
NASA Astrophysics Data System (ADS)
Mumtaz, M.; Baig, Mirza Hassan; Waqee-ur-Rehman, M.; Nasir Khan, M.
2018-05-01
Solid-state reaction method was used to synthesize Cu0.5Tl0.5Ba2Ca2Cu3O10-δ (CuTl-1223) superconducting phase and sol-gel method was used to prepare cobalt oxide (Co3O4) magnetic nanoparticles. These Co3O4 nanoparticles were added in CuTl-1223 superconducting matrix to get (Co3O4)x/CuTl-1223; x = 0-2.00 wt.% nanoparticles-superconductor composites. The effects of Co3O4 nanoparticles on crystal structure, phase formation, phase purity and infield superconducting transport properties of CuTl-1223 phase were investigated at different operating temperatures and external applied magnetic fields. The crystal structure and phase formation of Co3O4 nanoparticles and CuTl-1223 superconductor were determined by X-ray diffraction (XRD) technique. XRD peaks of Co3O4 nanoparticles were well indexed according to FCC crystal structure and the average particle size of 70 nm was calculated by using Debye-Scherer's formula. The unaltered crystal structure of host CuTl-1223 superconducting phase (i.e. Tetragonal) with the addition of Co3O4 nanoparticles indicated the dispersion of nanoparticles at inter-granular sites. Temperature dependent magneto-transport superconducting properties of (Co3O4)x/CuTl-1223 composites were investigated by zero field cooled (ZFC) and field cooled (FC) magnetic moment versus temperature (M-T) measurements. The onset transition temperatures {TcOnset (K)} was decreased along with the suppression of diamagnetic amplitude of CuTl-1223 superconducting phase with the addition of magnetic Co3O4 nanoparticles. Temperature dependent magnetic hysteresis (M-H loops) measurements of (Co3O4)x/CuTl-1223 composites were carried out at different operating temperatures from 5 K to 150 K. Critical current density (Jc) was calculated from M-H loops measurements by using Bean's model. Like the suppression of TcOnset (K) values, Jc was also decreased with the inclusion of Co3O4 nanoparticles. It was also observed that variation of Jc with H followed the power law Jc = βH-α at low operating temperatures 5 K and 20 K only.
High quality uniform YBCO film growth by the metalorganic deposition using trifluoroacetates
NASA Astrophysics Data System (ADS)
Wang, S. S.; Zhang, Z. L.; Wang, L.; Gao, L. K.; Liu, J.
2017-03-01
A need exists for the large-area superconducting YBa2Cu3O7-x (YBCO) films with high critical current density for microwave communication and/or electric power applications. Trifluoroacetic metalorganic (TFA-MOD) method is a promising low cost technique for large-scale production of YBCO films, because it does not need high vacuum device and is easily applicable to substrates of various shape and size. In this paper, double-sided YBCO films with maximum 2 in diameter were prepared on LaAlO3 substrates by TFA-MOD method. Inductive critical current densitiy Jc, microwave surface resistance Rs, as well as the microstructure were characterized. A newly homemade furnace system was used to epitaxially grown YBCO films, which can improve the uniformity of YBCO film significantly by gas supply and temperature distribution proper design. Results showed that the large area YBCO films were very uniform in microstructure and thickness distribution, an average inductive Jc in excess of 6 MA/cm2 with uniform distribution, and low Rs (10 GHz) below 0.3 mΩ at 77 K were obtained. Andthe film filter may be prepared to work at temperatures lower than 74 K. These results are very close to the highest value of YBCO films made by conventional vacuum method, so we show a very promising route for large-scale production of high quality large-area YBCO superconducting films at a lower cost.
NASA Astrophysics Data System (ADS)
Prando, G.; Carretta, P.; de Renzi, R.; Sanna, S.; Palenzona, A.; Putti, M.; Tropeano, M.
2011-05-01
Ac susceptibility and static magnetization measurements were performed in the optimally doped SmFeAsO0.8F0.2 superconductor. The field-temperature phase diagram of the superconducting state was drawn, and, in particular, the features of the flux lines were derived. The dependence of the intragrain depinning energy on the magnetic field intensity was derived in the thermally activated flux-creep framework, enlightening a typical 1/H dependence in the high-field regime. The intragrain critical current density was extrapolated in the zero-temperature and zero-magnetic-field limit, showing a remarkably high value Jc0(0)~2×107 A/cm2, which demonstrates that this material is rather interesting for potential future technological applications.
ERIC Educational Resources Information Center
Johnston, Basil
1978-01-01
Describing the values and moral orientations associated with the Cannibal Dance Ceremony, this article emphasizes the Kwahiutl's belief in the free will to choose between good or selflessness and evil or selfishness. (JC)
NASA Astrophysics Data System (ADS)
Chopra, Manoj
High temperature superconductors (HTS) have many potential applications e.g. magnetically levitated trains, power transmission, mechanical energy storage, dent pullers, Nuclear Magnetic Resonance (N.M.R), magnetic resonance imaging (M.R.I) etc. However, one of the most daunting tasks for the applicability of HTS is the enhancement of critical current density (Jc) and flux-pinning at liquid nitrogen temperatures by microstructure design. The addition of Ysb2BaCuOsb5 (211) particles to large grain melt textured YBasb2Cusb3Osb{7-delta} (Y123) have significantly improved the transport and magnetic properties of this material. Here, a systematic quantitative analysis on the effects of the 211 addition was performed on a microscopic scale with a systematic variation in the initial volume percentage of 211. From the correlation between critical current measurements and quantitative microscopy of both (001) and (110) sections, a maximum value of Jc was observed corresponding to a measured Y123 volume percent of 20% ± 3%. Accounting for the loss of liquid phase for the present processing, the corresponding optimum initial volume of 211 for the highest measured Jc was 40%. Further comparison between the weighted Jc and the true flux pinning force (Fp) also showed a maximum pinning force for an initial 211 addition of 40%. Although, the weighted Jc starts to decrease with an initial 211 volume of above 40%, the pinning efficiency at higher magnetic fields (2-4T) of the superconducting Y123 matrix was actually improved with an increasing 211 addition to at least 50%. Though an increasing addition of 211 was effective in producing efficient flux pinning sites in the Y123 matrix, percolation paths in the Y123 matrix became limited for supercurrent flow. Hence, a measured 211 volume corresponding to 80% 211 was shown to have the best possible critical current density. Furthermore, crack opening and crack spacing of the superficial cracks were found to decrease with an increasing 211 addition and with a decreasing 211 interparticle spacing. The penetration and surface length of each of these superficial cracks were hence reduced, which led to better electrical connectivity in the Y123 matrix. In addition, the effect of additives such as platinum and cerium oxide and their effect on the defect microstructure was quantitatively determined. Average twin spacing observed experimentally, suggested that the twin boundary energy (gammasb{tw}) was 28.9mJ/msp2 normally, while it decreased to 11.35mJ/msp2 for the 0.5wt% PtOsb2 doping and 23.6 mJ/msp2 for the case of 1 wt% CeOsb2 addition. The resultant twin morphology was also found to be substantially finer with PtOsb2 doping. Twin boundary energies were independently determined from twin shape analysis. Closer observation of the twins around a 211/Y123 interface showed a {1/ Rsp2} functional dependence of the local twin spacing at the 211/Y123 interface. The present study has also led to the identification of certain novel twin structures that have been shown to he efficient flux pinning sites. A study of this structure and its relationship with 211 particle shape, dispersion and proximity to its neighbors and its consequent effect on flux pinning was shown.
Xiong, Wangdan; Wei, Qian; Wu, Pingzhi; Zhang, Sheng; Li, Jun; Chen, Yaping; Li, Meiru; Jiang, Huawu; Wu, Guojiang
2017-07-01
The β-ketoacyl-acyl carrier protein synthase I (KASI) is involved in de novo fatty acid biosynthesis in many organisms. Two putative KASI genes, JcKASI-1 and JcKASI-2, were isolated from Jatropha curcas. The deduced amino acid sequences of JcKASI-1 and JcKASI-2 exhibit around 83.8% and 72.5% sequence identities with AtKASI, respectively, and both contain conserved Cys-His-Lys-His-Phe catalytic active sites. Phylogenetic analysis indicated that JcKASI-2 belongs to a clade with several KASI proteins from dicotyledonous plants. Both JcKASI genes were expressed in multiple tissues, most strongly in filling stage seeds of J. curcas. Additionally, the JcKASI-1 and JcKASI-2 proteins were both localized to the plastids. Expressing JcKASI-1 in the Arabidopsis kasI mutant rescued the mutant's phenotype and restored the fatty acid composition and oil content in seeds to wild-type, but expressing JcKASI-2 in the Arabidopsis kasI mutant resulted in only partial rescue. This implies that JcKASI-1 and JcKASI-2 exhibit partial functional redundancy and KASI genes play a universal role in regulating fatty acid biosynthesis, growth, and development in plants. Copyright © 2017 Elsevier GmbH. All rights reserved.
USDA-ARS?s Scientific Manuscript database
The Janzen-Connell (JC) hypothesis provides a powerful framework for explaining the maintenance of tree diversity in tropical forests. Its central tenet -- that recruits experience high mortality near conspecifics and at high densities -- assumes a degree of host specialization in interactions betwe...
Signe B. Leirfallom; Robert E. Keane; Diana F. Tomback; Solomon Z. Dobrowski
2015-01-01
Whitebark pine (Pinus albicaulis Engelm.) populations are declining nearly rangewide from a combination of factors, including mountain pine beetle (Dendroctonus ponderosae Hopkins, 1902) outbreaks, the exotic pathogen Cronartium ribicola J.C. Fisch. 1872, which causes the disease white pine blister rust, and successional replacement due to historical fire...
Advantageous grain boundaries in iron pnictide superconductors
Katase, Takayoshi; Ishimaru, Yoshihiro; Tsukamoto, Akira; Hiramatsu, Hidenori; Kamiya, Toshio; Tanabe, Keiichi; Hosono, Hideo
2011-01-01
High critical temperature superconductors have zero power consumption and could be used to produce ideal electric power lines. The principal obstacle in fabricating superconducting wires and tapes is grain boundaries—the misalignment of crystalline orientations at grain boundaries, which is unavoidable for polycrystals, largely deteriorates critical current density. Here we report that high critical temperature iron pnictide superconductors have advantages over cuprates with respect to these grain boundary issues. The transport properties through well-defined bicrystal grain boundary junctions with various misorientation angles (θGB) were systematically investigated for cobalt-doped BaFe2As2 (BaFe2As2:Co) epitaxial films fabricated on bicrystal substrates. The critical current density through bicrystal grain boundary (JcBGB) remained high (>1 MA cm−2) and nearly constant up to a critical angle θc of ∼9°, which is substantially larger than the θc of ∼5° for YBa2Cu3O7–δ. Even at θGB>θc, the decay of JcBGB was much slower than that of YBa2Cu3O7–δ. PMID:21811238
NASA Astrophysics Data System (ADS)
Dou, S. X.; Pan, A. V.; Zhou, S.; Ionescu, M.; Wang, X. L.; Horvat, J.; Liu, H. K.; Munroe, P. R.
2003-08-01
We investigated the effect of SiC nanoparticle doping on the crystal lattice structure, critical temperature Tc, critical current density Jc, and flux pinning in MgB2 superconductor. A series of MgB2-x(SiC)x/2 samples with x=0-1.0 were fabricated using an in situ reaction process. The contraction of the lattice and depression of Tc with increasing SiC doping level remained rather small most likely due to the counterbalancing effect of Si and C co-doping. The high level Si and C co-doping allowed the creation of intragrain defects and highly dispersed nanoinclusions within the grains which can act as effective pinning centers for vortices, improving Jc behavior as a function of the applied magnetic field. The enhanced pinning is mainly attributable to the substitution-induced defects and local structure fluctuations within grains. A pinning mechanism is proposed to account for different contributions of different defects in MgB2-x(SiC)x/2 superconductors.
Educational Evaluation and the Hartman Value Profile.
ERIC Educational Resources Information Center
Byrum, Stephen C.
1979-01-01
A tool consisting of 2 sets of 18 statements and requiring 20 minutes for administration, the Hartman Value Profile evaluates progress and maturity in areas not readily adaptable to more objective means of evaluation. Firsthand experiences with the HVP have indicated successful evaluations of postsecondary student thinking. (JC)
Forum, Changing Values: Where are We Going?
ERIC Educational Resources Information Center
Haney, Peggy H., Ed.; And Others
This issue of "Forum" magazine for adults and accompanying teaching units for use with students of all age levels deals with recent value trends. "Forum" is one of a group of educational publications and teaching units that JC Penney stores provide for local community groups and school consumer education programs. The magazine…
Misra, Aparna; Khan, Kasim; Niranjan, Abhishek; Kumar, Vinod; Sane, Vidhu A
2017-10-01
Oils and fats are stored in endosperm during seed development in the form of triacylglycerols. Three acyltransferases: glycerol-3-phosphate acyltransferase (GPAT), lysophosphatidyl acyltransferase (LPAT) and diacylglycerol acyltransferase (DGAT) are involved in the storage lipid biosynthesis and catalyze the stepwise acylation of glycerol backbone. In this study two members of GPAT gene family (JcGPAT1 and JcGPAT2) from Jatropha seeds were identified and characterized. Sequence analysis suggested that JcGPAT1 and JcGPAT2 are homologous to Arabidopsis acyltransferase-1 (ATS1) and AtGPAT9 respectively. The sub-cellular localization studies of these two GPATs showed that JcGPAT1 localizes into plastid whereas JcGPAT2 localizes in to endoplasmic reticulum. JcGPAT1 and JcGPAT2 expressed throughout the seed development with higher expression in fully matured seed compared to immature seed. The transcript levels of JcGPAT2 were higher in comparison to JcGPAT1 in different developmental stages of seed. Over-expression of JcGPAT1 and JcGPAT2 under constitutive and seed specific promoters in Arabidopsis thaliana increased total oil content. Transgenic seeds of JcGPAT2-OE lines accumulated 43-60% more oil than control seeds whereas seeds of Arabidopsis lines over-expressing plastidial GPAT lead to only 13-20% increase in oil content. Functional characterization of GPAT homologues of Jatropha in Arabidopsis suggested that these are involved in oil biosynthesis but might have specific roles in Jatropha. Copyright © 2017 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Abd-Shukor, R.; Jannah, A. N.
2017-09-01
Many new superconducting materials have been discovered in recent years. This includes hydrogen sulfide which superconducts at 203 K under high pressure and Fe-As based materials. To this date the copper oxide-based materials remain as the highest transition temperature superconductor under normal pressure. In this paper we discuss the use of nano-sized particle as pinning center in the Ag-sheathed high temperature superconductor tapes to enhance the transport properties. When the size d of the pinning center is between the coherence length ξ and the penetration depth λ (ξ < d < λ), a stronger interaction between the pinning center and flux lines leading to higher transport critical current density, Jc can be expected. The effect of nanoparticle with size between the coherence length and the penetration depth i.e. ξ < d < λ, Co3O4 on superconductor tapes is discussed in this paper. Three types of Bi(Pb)-Sr-Ca-Cu-O starting materials namely from co-precipitation method without Co3O4 and with 30 nm and 50 nm Co3O4 addition have been prepared. The composition of the 30 nm and 50 nm Co3O4 added samples is (Bi1.6Pb0.4)Sr2Ca2Cu3O10-(Co3O4)0.02 and (Bi1.6Pb0.4)Sr2Ca2Cu3O10-(Co3O4)0.01, respectively. The tapes (˜2-3 cm long) were heated at 845°C for 100 and 150 h. All nanoparticles added tapes showed higher Jc compared to the non-added tapes. By comparing the current results with our previously reported results, the tapes with 30 nm Co3O4 sintered for 50 h showed the highest Jc at all temperatures. This work also showed that smaller magnetic nanoparticles enhanced Jc better than larger particles, A longer sintering time (> 50 h) degraded Jc.
"Dear Teacher, Johnny Copied."
ERIC Educational Resources Information Center
Jackson, Louise A.; And Others
1987-01-01
Presents the problem of intentional or unintentional plagiarism on the part of young students, several possible causes for it, and offers ways teachers can help students avoid copying and understand the value of owning one's writing. (JC)
NASA Astrophysics Data System (ADS)
Nakamura, Y.; Shioiri, T.; Kurihara, C.; Machida, T.; Inada, R.; Oota, A.
2008-09-01
The use of alloy sheath is effective to increase the strength of Ag-sheathed Bi2223 tapes. However, the Jc value of alloy sheathed tapes was not high enough since the undesired reaction to form impurity phases and the change in formation rate of Bi2223 were disturbed by the microstructure of the filaments . In this study, the effect of 2223 contents in precursor on the formation and property of Bi2223 tapes sheathed with Ag-Mg alloy was investigated. The conversion rate of Bi2223 from Bi2212 was increased by the addition of Bi2223 phase in precursor but the conversion rate in Ag-Mg alloy sheathed tapes was slower than that in the Ag-Cu alloy sheathed tapes. This reduction of conversion speed of Bi2223 may be attributed to the decrease in the growth rate of Bi2223 crystals in Ag-Mg alloy sheath. Since the tapes with small Bi2223 crystals after first sintering showed many outgrowths after final sintering, the formation of outgrowth would be caused in the case of small crystal size. The Jc value of 2.2 × 10 4 A/cm 2 was achieved in the samples using the precursor with 10 wt.% 2223. The high Jc value can be achieved by the proper control of precursor condition including the contents of Bi2223 and corresponding heat treatment pattern in Ag-Mg alloy sheathed tapes.
Could JC virus provoke metastasis in colon cancer?
Sinagra, Emanuele; Raimondo, Dario; Gallo, Elena; Stella, Mario; Cottone, Mario; Orlando, Ambrogio; Rossi, Francesca; Orlando, Emanuele; Messina, Marco; Tomasello, Giovanni; Lo Monte, Attilio Ignazio; La Rocca, Ennio; Rizzo, Aroldo Gabriele
2014-01-01
AIM: To evaluate the prevalence of John Cunningham virus (JC virus) in a small cohort of patients with colon cancer and to assess its presence in hepatic metastasis. METHODS: Nineteen consecutive patients with histologically diagnosed colon cancer were included in our study, together with ten subjects affected by histologically and serologically diagnosed hepatitis C virus infection. In the patients included in the colon cancer group, JC virus was searched for in the surgical specimen; in the control group, JC virus was searched for in the hepatic biopsy. The difference in the prevalence of JC virus in the hepatic biopsy between the two groups was assessed through the χ2 test. RESULTS: Four out of 19 patients with colon cancer had a positive polymerase chain reaction (PCR) test for JC virus, and four had liver metastasis. Among the patients with liver metastasis, three out of four had a positive PCR test for JC virus in the surgical specimen and in the liver biopsy; the only patient with liver metastasis with a negative test for JC virus also presented a negative test for JC virus in the surgical specimen. In the control group of patients with hepatitis C infection, none of the ten patients presented JC virus infection in the hepatic biopsy. The difference between the two groups regarding JC virus infection was statistically significant (χ2 = 9.55, P = 0.002). CONCLUSION: JC virus may play a broader role than previously thought, and may be mechanistically involved in the late stages of these tumors. PMID:25400458
NASA Astrophysics Data System (ADS)
Yin, Hang; Shi, Ying
2018-05-01
Not Available Project supported by the National Basic Research Program of China (Grant No. 2013CB922204), the National Natural Science Foundation of China (Grant Nos. 11574115 and 11704146), and the Natural Science Foundation of Jilin Province, China (Grant No. 20150101063JC).
Sposato, Bruno; Scalese, Macro
2013-01-01
The aim was to evaluate the impact of Cupressus sempervirens (Cs) and Juniperus communis (Jc) sensitisations in "Maremma" in southern Tuscany. 811 consecutive outpatients (357 F - 57.86%; age: 36.9 ± 16.6) with suspected allergic respiratory symptoms underwent skin prick tests (SPT) for common allergens and for Cs and Jc. SPT resulted negative in 295 (36.37%) subjects. A Cs/Jc sensitisation was found in 294 (36.25%): 289 (98.3%) were sensitised to Cs whereas 198 (67.34%) to Jc. There was a co-sensitisation between Cs and Jc in 193 (65.6%) subjects. Cs/Jc mono-sensitisation was found in 39 (13.6%) subjects. A higher number (p<0.0001) of Cs/Jc sensitised subjects reported winter (131-44.55%) and spring (124-42.2%) symptoms compared to Cs/Jc non-sensitised and non-allergic subjects. Most Cs/Jc sensitised subjects reported rhinitis and conjunctivitis (p<0.0001), whereas only few reported coughing and asthma (p<0.01). The most frequent co-sensitisation was with grass, olive and other trees in Cs/Jc subjects (p<0.001). Those who reported winter symptoms, likely influenced by Cupressaceae, rhinitis was the main symptom whereas asthma was less frequent. Cs/Jc sensitisation resulted to be a risk factor (OR: 1.73 [CI95% 1.18-2.55]) for rhinitis whereas the probability of being asthmatic was reduced (OR: 0.62 [CI95% 0.44-0.85]). The prevalence of Cs/Jc sensitisation is about 36% in "Maremma". However, only in 44% of the patients, Cs/Jc seem to cause typical winter symptoms. Rhinitis is the predominant symptom, whereas asthma is less frequent. Testing Cupressaceae sensitisation using Jc pollen extract, rather than Cs, may result to be less sensitive. Copyright © 2011 SEICAP. Published by Elsevier Espana. All rights reserved.
Definition of current density in the presence of a non-local potential.
Li, Changsheng; Wan, Langhui; Wei, Yadong; Wang, Jian
2008-04-16
In the presence of a non-local potential arising from electron-electron interaction, the conventional definition of current density J(c) = (e/2m)([(p-eA)ψ](*)ψ-ψ(*)[(p-eA)ψ]) cannot satisfy the condition of current conservation, i.e., [Formula: see text] in the steady state. In order to solve this problem, we give a new definition of current density including the contribution due to the non-local potential. We show that the current calculated based on the new definition of current density conserves the current and is the same as that obtained from the Landauer-Büttiker formula. Examples are given to demonstrate our results.
Heald, Steve M.; Tarantini, Chiara; Lee, Peter J.; ...
2018-03-19
To meet critical current density, Jc, targets for the Future Circular Collider (FCC), the planned replacement for the Large Hadron Collider (LHC), the high field performance of Nb 3Sn must be improved, but champion J c values have remained static for the last 10 years. Making the A15 phase stoichiometric and enhancing the upper critical field H c2 by Ti or Ta dopants are the standard strategies for enhancing high field performance but detailed recent studies show that even the best modern wires have broad composition ranges. To assess whether further improvement might be possible, we employed EXAFS to determinemore » the lattice site location of dopants in modern high-performance Nb 3Sn strands with J c values amongst the best so far achieved. Although Ti and Ta primarily occupy the Nb sites in the A15 structure, we also find significant Ta occupancy on the Sn site. These findings indicate that the best performing Ti-doped stand is strongly sub-stoichiometric in Sn and that antisite disorder likely explains its high average H c2 behavior. These new results suggest an important role for dopant and antisite disorder in minimizing superconducting property distributions and maximizing high field J c properties.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Heald, Steve M.; Tarantini, Chiara; Lee, Peter J.
To meet critical current density, Jc, targets for the Future Circular Collider (FCC), the planned replacement for the Large Hadron Collider (LHC), the high field performance of Nb 3Sn must be improved, but champion J c values have remained static for the last 10 years. Making the A15 phase stoichiometric and enhancing the upper critical field H c2 by Ti or Ta dopants are the standard strategies for enhancing high field performance but detailed recent studies show that even the best modern wires have broad composition ranges. To assess whether further improvement might be possible, we employed EXAFS to determinemore » the lattice site location of dopants in modern high-performance Nb 3Sn strands with J c values amongst the best so far achieved. Although Ti and Ta primarily occupy the Nb sites in the A15 structure, we also find significant Ta occupancy on the Sn site. These findings indicate that the best performing Ti-doped stand is strongly sub-stoichiometric in Sn and that antisite disorder likely explains its high average H c2 behavior. These new results suggest an important role for dopant and antisite disorder in minimizing superconducting property distributions and maximizing high field J c properties.« less
NASA Astrophysics Data System (ADS)
Loveley, M. R.; Marcantonio, F.; Lyle, M. W.; Wang, J. K.
2013-12-01
In this study, we attempt to understand how preferential sorting of fine particles during redistribution processes in the Panama Basin affects the 230Th constant-flux proxy. Fine particles likely contain greater amounts of 230Th, so that preferential sorting of fine particles may bias sediment mass accumulation rates (MARs). We examined sediments that span the past 25 kyr from two new sediment cores retrieved within about 56 km of each other in the northern part of the basin (MV1013-01-'4JC', 5° 44.699'N 85° 45.498' W, 1730 m depth; MV1014-01-'8JC', 6° 14.038'N 86° 2.613' W, 1993 m depth). Core 4JC, closer to the ridge top that bounds the basin (Cocos Ridge), has a thin sediment drape, while the deeper core 8JC, has a thicker sediment drape and lies further from the ridge top. 230Th-derived focusing factors from 4JC are similar and suggest winnowing with average values of about 0.5 and 0.6 during the Holocene and the last glacial, respectively. For 8JC, calculated average focusing factors are significantly different and suggest focusing with values of about 2 during the Holocene and 4 during the last glacial. Since the two sites are close to each other, one would expect similar rain rates and, therefore, similar 230Th-derived MARs within similar windows of time, i.e., the rain rate should not vary significantly at each site temporally. In addition, the radiocarbon-derived sand (>63μm) MARs should behave similarly since coarser particles are likely not transported by bottom currents. Sand MARs are, indeed, similar during the Holocene and the last glacial at each site. During the last glacial, however, sand MARs are about a factor of 3 higher than those during the Holocene. On the other hand, there is little variability in the 230Th-derived MARs both spatially and temporally. We interpret the discrepancies between the radiocarbon-derived sand and 230Th-derived MARs as being due to preferential sorting of fine particles during the redistribution of sediments by deep-sea currents. The 230Th-derived focusing factors are being overestimated at the deeper site and vice versa at the shallower site, and the degree of inaccuracy varies temporally. We discuss this temporal variability and its relationship to deep-sea current velocities.
NASA Astrophysics Data System (ADS)
Sotelo, A.; Madre, M. A.; Diez, J. C.; Rasekh, Sh; Angurel, L. A.; Martínez, E.
2009-03-01
Textured rods of Bi-2212 based materials with nominal compositions Bi2Sr2CaCu2O8+δ, Bi2Sr2CaCu2O8+δ+1 wt% Ag, Bi1.6Pb0.4Sr2CaCu2O8+δ, and Bi1.6Pb0.4Sr2CaCu2O8+δ+3 wt% Ag were fabricated using a laser floating zone (LFZ) melting method. The electrical, magnetic, and mechanical properties of the resulting rods after annealing were characterized. Pb doping results in the decrease of the transport critical current density, Jc,t (from 4.4 × 107 to 6 × 106 A m-2 at 65 K and self-field) as well as in the worsening of the mechanical properties, by about 35% compared to the undoped samples. In contrast, Ag doping results in the improvement of both the critical current density and mechanical strength. In this regard we have observed an increase of Jc,t (65 K) from 4.4 × 107 for Bi-2212 to 7.2 × 107 A m-2 for Bi-2212/Ag and from 6 × 106 for Bi(Pb)-2212 to 8 × 106 A m-2 for Bi(Pb)-2212/Ag. These described effects are related to the microstructural observations, since Pb doping dramatically reduces the texture while Ag doping improves it. Moreover, for samples with Ag addition, an intergrowth of Bi-2223 inside the Bi-2212 grains is observed, which would explain the improved superconducting properties of these samples.
Critical current density and third-harmonic voltage in superconducting films
NASA Astrophysics Data System (ADS)
Mawatari, Yasunori; Yamasaki, Hirofumi; Nakagawa, Yoshihiko
2002-09-01
When a sinusoidal drive current I0cos ωt flows in a small coil close to the surface of a superconducting film, third-harmonic voltage V3 cos(3ωt+θ3) is induced in the coil if the film causes a nonlinear response. We have developed an approximate theoretical method yielding the relationships among I0, V3, and θ3, thus providing the scientific basis for a widely used inductive method for measuring the critical current density Jc in large-area superconducting films. Our results show that V3 is near zero when I0 is smaller than a threshold value Ic0∝Jcd, where d is the film thickness. When I0>Ic0, on the other hand, the third-harmonic voltage is expressed as V3 exp(-iθ3)=ωIc0G(I0/Ic0), where G(x) is a scaling function determined by the configuration of the coil. We demonstrate the scaling law of V3/Ic0 vs I0/Ic0 in a YBa2Cu3O7-δ film.
Richter, Craig G; Thompson, William H; Bosman, Conrado A; Fries, Pascal
2015-07-01
The quantification of covariance between neuronal activities (functional connectivity) requires the observation of correlated changes and therefore multiple observations. The strength of such neuronal correlations may itself undergo moment-by-moment fluctuations, which might e.g. lead to fluctuations in single-trial metrics such as reaction time (RT), or may co-fluctuate with the correlation between activity in other brain areas. Yet, quantifying the relation between moment-by-moment co-fluctuations in neuronal correlations is precluded by the fact that neuronal correlations are not defined per single observation. The proposed solution quantifies this relation by first calculating neuronal correlations for all leave-one-out subsamples (i.e. the jackknife replications of all observations) and then correlating these values. Because the correlation is calculated between jackknife replications, we address this approach as jackknife correlation (JC). First, we demonstrate the equivalence of JC to conventional correlation for simulated paired data that are defined per observation and therefore allow the calculation of conventional correlation. While the JC recovers the conventional correlation precisely, alternative approaches, like sorting-and-binning, result in detrimental effects of the analysis parameters. We then explore the case of relating two spectral correlation metrics, like coherence, that require multiple observation epochs, where the only viable alternative analysis approaches are based on some form of epoch subdivision, which results in reduced spectral resolution and poor spectral estimators. We show that JC outperforms these approaches, particularly for short epoch lengths, without sacrificing any spectral resolution. Finally, we note that the JC can be applied to relate fluctuations in any smooth metric that is not defined on single observations. Copyright © 2015. Published by Elsevier Inc.
Cloning and characterization of a SnRK2 gene from Jatropha curcas L.
Chun, J; Li, F-S; Ma, Y; Wang, S-H; Chen, F
2014-12-19
Although the SnRK2 class of Ser/Thr protein kinases is critical for signal transduction and abiotic stress resistance in plants, there have been no studies to examine SnRK2 in Jatropha curcas L. In the present study, JcSnRK2 was cloned from J. curcas using the rapid amplification of cDNA end technique and characterized. The JcSnRK2 genomic sequence is 2578 base pairs (bp), includes 10 exons and 9 introns, and the 1017-bp open reading frame encodes 338 amino acids. JcSnRK2 was transcribed in all examined tissues, with the highest transcription rate observed in the roots, followed by the leaves and stalks; the lowest rate was observed in flowers and seeds. JcSnRK2 expression increased following abscisic acid treatment, salinity, and drought stress. During a 48-h stress period, the expression of JcSnRK2 showed 2 peaks and periodic up- and downregulation. JcSnRK2 was rapidly activated within 1 h under salt and drought stress, but not under cold stress. Because of the gene sequence and expression similarity of JcSnRK2 to AtSnRK2.8, primarily in the roots, an eukaryotic expression vector containing the JcSnRK2 gene (pBI121-JcSnRK2) was constructed and introduced to the Arabidopsis AtSnRK2.8 mutant snf2.8. JcSnRK2-overexpressing plants exhibited higher salt and drought tolerance, further demonstrating the function of JcSnRK2 in the osmotic stress response. J. curcas is highly resistant to extreme salt and drought conditions and JcSnRK2 was found to be activated under these conditions. Thus, JcSnRK2 is potential candidate for improving crop tolerance to salt and drought stress.
Free flux flow in two single crystals of V3Si with differing pinning strengths
NASA Astrophysics Data System (ADS)
Gafarov, O.; Gapud, A. A.; Moraes, S.; Thompson, J. R.; Christen, D. K.; Reyes, A. P.
2011-10-01
Results of measurements on two very clean, single-crystal samples of the A15 superconductor V3Si are presented. Magnetization and transport data have confirmed the ``clean'' quality of both samples, as manifested by: (i) high residual electrical resistivity ratio, (ii) very low critical current densities Jc, and (iii) a ``peak'' effect in the field dependence of critical current. The (H,T) phase line for this peak effect is shifted down for the slightly ``dirtier'' sample, which consequently also has higher critical current density Jc(H). Large Lorentz forces are applied on mixed-state vortices via large currents, in order to induce the highly ordered free flux flow (FFF) phase, using experimental methods developed previously. The traditional model by Bardeen and Stephen (BS) predicts a simple field dependence of flux flow resistivity ρf(H) ˜ H/Hc2, presuming a field-independent flux core size. A model by Kogan and Zelezhina (KZ) takes into account the effects of magnetic field on core size, and predict a clear deviation from the linear BS dependence. In this study, ρf(H) is confirmed to be consistent with predictions of KZ.
Influence of substrate type on transport properties of superconducting FeSe0.5Te0.5 thin films
NASA Astrophysics Data System (ADS)
Yuan, Feifei; Iida, Kazumasa; Langer, Marco; Hänisch, Jens; Ichinose, Ataru; Tsukada, Ichiro; Sala, Alberto; Putti, Marina; Hühne, Ruben; Schultz, Ludwig; Shi, Zhixiang
2015-06-01
FeSe0.5Te0.5 thin films were grown by pulsed laser deposition on CaF2, LaAlO3 and MgO substrates and structurally and electro-magnetically characterized in order to study the influence of the substrate on their transport properties. The in-plane lattice mismatch between FeSe0.5Te0.5 bulk and the substrate shows no influence on the lattice parameters of the films, whereas the type of substrate affects the crystalline quality of the films and, therefore, the superconducting properties. The film on MgO showed an extra peak in the angular dependence of critical current density Jc(θ) at θ = 180° (H||c), which arises from c-axis defects as confirmed by transmission electron microscopy. In contrast, no Jc(θ) peaks for H||c were observed in films on CaF2 and LaAlO3. Jc(θ) can be scaled successfully for both films without c-axis correlated defects by the anisotropic Ginzburg-Landau approach with appropriate anisotropy ratio γJ. The scaling parameter γJ is decreasing with decreasing temperature, which is different from what we observed in FeSe0.5Te0.5 films on Fe-buffered MgO substrates.
Polycrystalline Superconducting Thin Films: Texture Control and Critical Current Density
NASA Astrophysics Data System (ADS)
Yang, Feng
1995-01-01
The growth processes of polycrystalline rm YBa_2CU_3O_{7-X} (YBCO) and yttria-stabilized-zirconia (YSZ) thin films have been developed. The effectiveness of YSZ buffer layers on suppression of the reaction between YBCO thin films and metallic substrates was carefully studied. Grown on the chemically inert surfaces of YSZ buffer layers, YBCO thin films possessed good quality of c-axis alignment with the c axis parallel to the substrate normal, but without any preferred in-plane orientations. This leads to the existence of a large percentage of the high-angle grain boundaries in the YBCO films. The critical current densities (rm J_{c}'s) found in these films were much lower than those in single crystal YBCO thin films, which was the consequence of the weak -link effect of the high-angle grain boundaries in these films. It became clear that the in-plane alignment is vital for achieving high rm J_{c }s in polycrystalline YBCO thin films. To induce the in-plane alignment, ion beam-assisted deposition (IBAD) technique was integrated into the conventional pulsed laser deposition process for the growth of the YSZ buffer layers. It was demonstrated that using IBAD the in-plane orientations of the YSZ grains could be controlled within a certain range of a common direction. This ion -bombardment induced in-plane texturing was explained using the anisotropic sputtering yield theory. Our observations and analyses have provided valuable information on the optimization of the IBAD process, and shed light on the texturing mechanism in YSZ. With the in-plane aligned YSZ buffer layers, YBCO thin films grown on metallic substrates showed improved rm J_{c}s. It was found that the in-plane alignment of YSZ and that of YBCO were closely related. A direct correlation was revealed between the rm J_{c} value and the degree of the in-plane alignment for the YBCO thin films. To explain this correlation, a numerical model was applied to multi-grain superconducting paths with different textures to determine the expected rm J_{c}s. The good agreement between the experimental data and numerical results confirmed that the rm J_{c} improvement directly resulted from the reduction of the number of high-angle grain boundaries in the in-plane aligned polycrystalline YBCO thin films, and provided a guideline on the further improvement of the rm J_ {c}s of polycrystalline YBCO thin films.
Migration of Interplanetary Dust and Comets
NASA Astrophysics Data System (ADS)
Ipatov, S. I.; Mather, J. C.
Our studies of migration of interplanetary dust and comets were based on the results of integration of the orbital evolution of 15,000 dust particles and 30,000 Jupiter-family comets (JFCs) [1-3]. For asteroidal and cometary particles, the values of the ratio β between the radiation pressure force and the gravitational force varied from <0.0004 to 0.4. For silicates, such values correspond to particle diameters between >1000 and 1 microns. The probability of a collision of a dust particle started from an asteroid or JFC with the Earth during a lifetime of the particle was maximum at diameter d ˜100 microns. For particles started from asteroids and comet 10P, this maximum probability was ˜0.01. Different studies of migration of dust particles and small bodies testify that the fraction of cometary dust particles of the overall dust population inside Saturn's orbit is considerable and can be dominant: (1) Cometary dust particles produced both inside and outside Jupiter's orbit are needed to explain the observed constant number density of dust particles at 3-18 AU. The number density of migrating trans-Neptunian particles near Jupiter's orbit is smaller by a factor of several than that beyond Saturn's orbit. Only a small fraction of asteroidal particles can get outside Jupiter's orbit. (2) Some (less than 0.1%) JFCs can reach typical near-Earth object orbits and remain there for millions of years. Dynamical lifetimes of most of the former JFCs that have typical near-Earth object orbits are about 106 -109 yr, so during most of these times they were extinct comets. Such former comets could disintegrate and produce a lot of mini-comets and dust. (3) Comparison of the velocities of zodiacal dust particles (velocities of MgI line) based on the distributions of particles over their orbital elements obtained in our runs [3-4] with the velocities obtained at the WHAM observations shows that only asteroidal dust particles cannot explain these observations, and particles produced by comets, including high-eccentricity comets, are needed for such explanation. The fraction of particles started from Encke-type comets is not large (<0.15) in order to fit the observational distributions of particles over their distances from the Sun. Studies of velocities of MgI line and corresponding eccentricities and inclinations in our runs showed that the mean eccentricity of zodiacal dust particles is about 0.5. [1] Ipatov S.I. and Mather J.C. (2004) Annals of the New York Acad. of Sciences, 1017, 46- 65. [2] Ipatov S.I., Mather J.C., and Taylor P. (2004) Annals of the New York Acad. of Sciences, 1017, 66-80. [3] Ipatov S.I. and Mather J.C. (2006) Advances in Space Research, 37, 126-137. [4] Ipatov S.I. et al. (2006) 37th LPSC, #1471.
Fabrication of superconducting nanowires from ultrathin MgB2 films via focused ion beam milling
NASA Astrophysics Data System (ADS)
Zhang, Chen; Wang, Da; Liu, Zheng-Hao; Zhang, Yan; Ma, Ping; Feng, Qing-Rong; Wang, Yue; Gan, Zi-Zhao
2015-02-01
High quality superconducting nanowires were fabricated from ultrathin MgB2 films by a focused ion beam milling technique. The precursor MgB2 films in 10 nm thick were grown on MgO substrates by using a hybrid physical-chemical vapor deposition method. The nanowires, in widths of about 300-600 nm and lengths of 1 or 10 μm, showed high superconducting critical temperatures (Tc's) above 34 K and narrow superconducting transition widths (ΔTc's) of 1-3 K. The superconducting critical current density Jc of the nanowires was above 5 × 107 A/cm2 at 20 K. The high Tc, narrow ΔTc, and high Jc of the nanowires offered the possibility of making MgB2-based nano-devices such as hot-electron bolometers and superconducting nanowire single-photon detectors with high operating temperatures at 15-20 K.
Technical issues of a high-Tc superconducting bulk magnet
NASA Astrophysics Data System (ADS)
Fujimoto, Hiroyuki
2000-06-01
Superconducting magnets made of high-Tc superconductors are promising for industrial applications. It is well known that REBa2Cu3O7-x superconductors prepared by melt processes have a high critical current density, Jc, at 77 K and high magnetic fields. The materials are very promising for high magnetic field applications as a superconducting permanent/bulk magnet with liquid-nitrogen refrigeration. Light rare-earth (LRE) BaCuO bulks, compared with REBaCuO bulks, exhibit a larger Jc in high magnetic fields and a much improved irreversibility field, Hirr, at 77 K. In this study, we discuss technical issues of a high-Tc superconducting bulk magnet, namely the aspects of the melt processing for bulk superconductors, their characteristic superconducting properties and mechanical properties, and trapped field properties of a superconducting bulk magnet. One of the possible applications is a superconducting bulk magnet for the magnetically levitated (Maglev) train in the future.
Zhuang, Yongliang; Hou, Hu; Zhao, Xue; Zhang, Zhaohui; Li, Bafang
2009-08-01
Collagen (JC) was extracted from jellyfish (Rhopilema esculentum) and hydrolyzed to prepare collagen hydrolysate (JCH). The protective effects of JC and JCH against UV-induced damages to mice skin were evaluated and compared in this article. JC and JCH could alleviate the UV-induced abnormal changes of antioxidative indicators, including the superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activities and the contents of glutathione (GSH) and malondiaidehyde (MDA). JC and JCH could protect skin lipid and collagen from the UV radiation damages. Furthermore, the changes of total ceramide and glycosaminoglycan in skin were recovered significantly by JC and JCH. The action mechanisms mainly involved the antioxidative properties and the repairing to endogenous collagen synthesis of JC and JCH in vivo. JCH with the lower molecular weight showed much higher effects than JC. The results indicated that JCH was a novel antiphotoaging agent from natural resources.
An ortholog of LEAFY in Jatropha curcas regulates flowering time and floral organ development.
Tang, Mingyong; Tao, Yan-Bin; Fu, Qiantang; Song, Yaling; Niu, Longjian; Xu, Zeng-Fu
2016-11-21
Jatropha curcas seeds are an excellent biofuel feedstock, but seed yields of Jatropha are limited by its poor flowering and fruiting ability. Thus, identifying genes controlling flowering is critical for genetic improvement of seed yield. We isolated the JcLFY, a Jatropha ortholog of Arabidopsis thaliana LEAFY (LFY), and identified JcLFY function by overexpressing it in Arabidopsis and Jatropha. JcLFY is expressed in Jatropha inflorescence buds, flower buds, and carpels, with highest expression in the early developmental stage of flower buds. JcLFY overexpression induced early flowering, solitary flowers, and terminal flowers in Arabidopsis, and also rescued the delayed flowering phenotype of lfy-15, a LFY loss-of-function Arabidopsis mutant. Microarray and qPCR analysis revealed several flower identity and flower organ development genes were upregulated in JcLFY-overexpressing Arabidopsis. JcLFY overexpression in Jatropha also induced early flowering. Significant changes in inflorescence structure, floral organs, and fruit shape occurred in JcLFY co-suppressed plants in which expression of several flower identity and floral organ development genes were changed. This suggests JcLFY is involved in regulating flower identity, floral organ patterns, and fruit shape, although JcLFY function in Jatropha floral meristem determination is not as strong as that of Arabidopsis.
An ortholog of LEAFY in Jatropha curcas regulates flowering time and floral organ development
Tang, Mingyong; Tao, Yan-Bin; Fu, Qiantang; Song, Yaling; Niu, Longjian; Xu, Zeng-Fu
2016-01-01
Jatropha curcas seeds are an excellent biofuel feedstock, but seed yields of Jatropha are limited by its poor flowering and fruiting ability. Thus, identifying genes controlling flowering is critical for genetic improvement of seed yield. We isolated the JcLFY, a Jatropha ortholog of Arabidopsis thaliana LEAFY (LFY), and identified JcLFY function by overexpressing it in Arabidopsis and Jatropha. JcLFY is expressed in Jatropha inflorescence buds, flower buds, and carpels, with highest expression in the early developmental stage of flower buds. JcLFY overexpression induced early flowering, solitary flowers, and terminal flowers in Arabidopsis, and also rescued the delayed flowering phenotype of lfy-15, a LFY loss-of-function Arabidopsis mutant. Microarray and qPCR analysis revealed several flower identity and flower organ development genes were upregulated in JcLFY-overexpressing Arabidopsis. JcLFY overexpression in Jatropha also induced early flowering. Significant changes in inflorescence structure, floral organs, and fruit shape occurred in JcLFY co-suppressed plants in which expression of several flower identity and floral organ development genes were changed. This suggests JcLFY is involved in regulating flower identity, floral organ patterns, and fruit shape, although JcLFY function in Jatropha floral meristem determination is not as strong as that of Arabidopsis. PMID:27869146
Tang, Yuehui; Liu, Kun; Zhang, Ju; Li, Xiaoli; Xu, Kedong; Zhang, Yi; Qi, Jing; Yu, Deshui; Wang, Jian; Li, Chengwei
2017-01-01
Transcription factors of the AP2/ERF family play important roles in plant growth, development, and responses to biotic and abiotic stresses. In this study, a physic nut AP2/ERF gene, JcDREB2 , was functionally characterized. Real-time PCR analysis revealed that JcDREB2 was expressed mainly in the leaf and could be induced by abscisic acid but suppressed by gibberellin (GA) and salt. Transient expression of a JcDREB2-YFP fusion protein in Arabidopsis protoplasts cells suggested that JcDREB2 is localized in the nucleus. Rice plants overexpressing JcDREB2 exhibited dwarf and GA-deficient phenotypes with shorter shoots and roots than those of wild-type plants. The dwarfism phenotype could be rescued by the application of exogenous GA 3 . The expression levels of GA biosynthetic genes including OsGA20ox1 , OsGA20ox2 , OsGA20ox4 , OsGA3ox2, OsCPS1 , OsKO2 , and OsKAO were significantly reduced in plants overexpressing JcDREB2 . Overexpression of JcDREB2 in rice increased sensitivity to salt stress. Increases in the expression levels of several salt-tolerance-related genes in response to salt stress were impaired in JcDREB2 -overexpressing plants. These results demonstrated not only that JcDREB2 influences GA metabolism, but also that it can participate in the regulation of the salt stress response in rice.
Sinha, Devanjan; Srivastava, Shubhi; D'Silva, Patrick
2016-08-12
Mitochondrial J-proteins play a critical role in governing Hsp70 activity and, hence, are essential for organellar protein translocation and folding. In contrast to yeast, which has a single J-protein Pam18, humans involve two J-proteins, DnaJC15 and DnaJC19, associated with contrasting cellular phenotype, to transport proteins into the mitochondria. Mutation in DnaJC19 results in dilated cardiomyopathy and ataxia syndrome, whereas expression of DnaJC15 regulates the response of cancer cells to chemotherapy. In the present study we have comparatively assessed the biochemical properties of the J-protein paralogs in relation to their association with the import channel. Both DnaJC15 and DnaJC19 formed two distinct subcomplexes with Magmas at the import channel. Knockdown analysis suggested an essential role for Magmas and DnaJC19 in organellar protein translocation and mitochondria biogenesis, whereas DnaJC15 had dispensable supportive function. The J-proteins were found to have equal affinity for Magmas and could stimulate mitochondrial Hsp70 ATPase activity by equivalent levels. Interestingly, we observed that DnaJC15 exhibits bifunctional properties. At the translocation channel, it involves conserved interactions and mechanism to translocate the precursors into mitochondria. In addition to protein transport, DnaJC15 also showed a dual role in yeast where its expression elicited enhanced sensitivity of cells to cisplatin that required the presence of a functional J-domain. The amount of DnaJC15 expressed in the cell was directly proportional to the sensitivity of cells. Our analysis indicates that the differential cellular phenotype displayed by human mitochondrial J-proteins is independent of their activity and association with Magmas at the translocation channel. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.
Strong-pinning regimes by spherical inclusions in anisotropic type-II superconductors
DOE Office of Scientific and Technical Information (OSTI.GOV)
Willa, R.; Koshelev, A. E.; Sadovskyy, I. A.
2017-11-27
The current-carrying capacity of type-II superconductors is decisively determined by how well material defect structures can immobilize vortex lines. In order to gain deeper insights into intrinsic pinning mechanisms, we have explored the case of vortex trapping by randomly distributed spherical inclusions using large-scale simulations of the time-dependent Ginzburg-Landau equations. We find that for a small density of particles having diameters of two coherence lengths, the vortex lattice preserves its structure and the critical current jc decays with the magnetic field following a power-law B-a with a ~ 0:66, which is consistent with predictions of strong pinning theory. For highermore » density of particles and/or larger inclusions, the lattice becomes progressively more disordered and the exponent smoothly decreases down to a ~ 0:3. At high magnetic fields, all inclusions capture a vortex and the critical current decays faster than B-1 as would be expected by theory. In the case of larger inclusions with diameter of four coherence length, the magnetic-field dependence of the critical current is strongly affected by the ability of inclusions to capture multiple vortex lines. We found that at small densities, the fraction of inclusions trapping two vortex lines rapidly grows within narrow field range leading to a shallow peak in jc(B)-dependence within this range. With increasing inclusion density, this peak transforms into a plateau, which then smooths out. Using the insights gained from simulations, we determine the limits of applicability of strong pinning theory and provide different routes to describe vortex pinning beyond those bounds.« less
NASA Astrophysics Data System (ADS)
Tripathi, D.; Dey, T. K.
2018-05-01
The effect of nanoscale aluminum nitride (n-AlN) and carbon (n-C) co-doping on superconducting properties of polycrystalline bulk MgB2 superconductor has been investigated. Polycrystalline pellets of MgB2, MgB2 + 0.5 wt% AlN (nano), MgB_{1.99}C_{0.01} and MgB_{1.99}C_{0.01} + 0.5 wt% AlN (nano) have been synthesized by a solid reaction process under inert atmosphere. The transition temperature (TC) estimated from resistivity measurement indicates only a small decrease for C (nano) and co-doped MgB2 samples. The magnetic field response of investigated samples has been measured at 4, 10, and 20 K in the field range ± 6 T. MgB2 pellets co-doped with 0.5 wt% n-AlN and 1 wt% n-C display appreciable enhancement in critical current density (J_C) of MgB2 in both low (≥ 3 times), as well as, high-field region (≥ 15 times). J_C versus H behavior of both pristine and doped MgB2 pellets is well explained in the light of the collective pinning model. Further, the normalized pinning force density f_p(= F_p/F_{pmax}) displays a fair correspondence with the scaling procedure proposed by Eisterer et al. Moreover, the scaled data of the pinning force density (i.e., f_p{-}h data) of the investigated pellets at different temperature are well interpreted by a modified Dew-Hughes expression reported by Sandu and Chee.
Physical property characterization of Fe-tube encapsulated and vacuum annealed bulk MgB 2
NASA Astrophysics Data System (ADS)
Awana, V. P. S.; Rawat, Rajeev; Gupta, Anurag; Isobe, M.; Singh, K. P.; Vajpayee, Arpita; Kishan, H.; Takayama-Muromachi, E.; Narlikar, A. V.
2006-08-01
We report the phase formation, and present a detailed study of magnetization and resistivity under magnetic field of MgB 2 polycrystalline bulk samples prepared by the Fe-tube encapsulated and vacuum (10 -5 Torr) annealed (750 ∘C) route. Zero-field-cooled magnetic susceptibility (χ) measurements exhibited a sharp transition to the superconducting state with a sizeable diamagnetic signal at 39 K (Tc). The measured magnetization loops of the samples, despite the presence of flux jumps, exhibited a stable current density (Jc) of around 2.4×10 5 A/cm 2 in up to 2 T (Tesla) field and at temperatures (T) up to 10 K. The upper critical field is estimated from resistivity measurements in various fields and shows a typical value of 8 T at 21 K. Further, χ measurements at an applied field of 0.1 T reveal a paramagnetic Meissner effect (PME) that is briefly discussed.
Electrical and magnetic properties of conductive Cu-based coated conductors
NASA Astrophysics Data System (ADS)
Aytug, T.; Paranthaman, M.; Thompson, J. R.; Goyal, A.; Rutter, N.; Zhai, H. Y.; Gapud, A. A.; Ijaduola, A. O.; Christen, D. K.
2003-11-01
The development of YBa2Cu3O7-δ (YBCO)-based coated conductors for electric power applications will require electrical and thermal stabilization of the high-temperature superconducting (HTS) coating. In addition, nonmagnetic tape substrates are an important factor in order to reduce the ferromagnetic hysteresis energy loss in ac applications. We report progress toward a conductive buffer layer architecture on biaxially textured nonmagnetic Cu tapes to electrically couple the HTS layer to the underlying metal substrate. A protective Ni overlayer, followed by a single buffer layer of La0.7Sr0.3MnO3, was employed to avoid Cu diffusion and to improve oxidation resistance of the substrate. Property characterizations of YBCO films on short prototype samples revealed self-field critical current density (Jc) values exceeding 2×106 A/cm2 at 77 K and good electrical connectivity. Magnetic hysteretic loss due to Ni overlayer was also investigated.
Ketas, Thomas J.; Kuhmann, Shawn E.; Palmer, Ashley; Zurita, Juan; He, Weijing; Ahuja, Sunil K.; Klasse, Per Johan; Moore, John P.
2007-01-01
Several CCR5 ligands, including small molecules and monoclonal antibodies (MAbs), are being developed as therapies for infection with strains of human immunodeficiency virus type 1 (HIV-1) that use CCR5 for entry (R5 viruses). The efficacy of such therapies could be influenced by inter-individual differences in host factors, such as CCR5 expression levels. To study this, we used peripheral blood mononuclear cells (PBMCs) from humans and rhesus macaques. The half-maximal inhibitory concentrations (IC50) of the small-molecule CCR5 ligands CMPD167, UK427,857 and SCH-D, and of the PRO 140 MAb, differ by >2 logs in a donor-dependent manner. We studied this variation by using flow cytometry to measure CCR5 expression on PBMCs from six of the human donors: the IC50 values of both SCH-D and PRO 140 correlated with CCR5 expression (R2 = 0.64 and 0.99, respectively). We also determined the efficacy of the CCR5 ligands against HIV-1 infection of HeLa-derived cell lines that express CD4 at the same level but vary 2-fold in CCR5 expression (JC.48 and JC.53 cells). The moderately greater CCR5 expression on the JC.53 than the JC.48 cells was associated with proportionately higher median IC50 values for all four CCR5 ligands but not for a soluble CD4-based inhibitor or a non-nucleoside reverse transcriptase inhibitor. We conclude that differences in CCR5 expression on human PBMCs, which can be affected by CCL3L1 gene dose, may influence the antiviral potency of CCR5 ligands in vitro, but other host factors are also likely to be involved. These host factors may affect the clinical activity of CCR5 inhibitors, including their use as topical microbicides to prevent HIV-1 transmission. PMID:17428518
NASA Astrophysics Data System (ADS)
Krelaus, J.; Heinemann, K.; Ullmann, B.; Freyhardt, H. C.
1995-02-01
Bulk YBa 2Cu 4O 8 (Y-124) is prepared from YBa 2Cu 3O 7-σ (Y-123) and CuO by a powder-metallurgical method. The superconducting features of the Y-124, in particular critical current densities and activation energies, are measured resistively using a four-probe technique and magnetically using a Faraday magnetometer. In a second step the Y-124 is decomposed at high temperatures. The intragranular critical current density is measured at different annealing times, tA, in order to determine and discuss the characteristics of the jc( tA) curves.
Li, Chaoqiong; Luo, Li; Fu, Qiantang; Niu, Longjian; Xu, Zeng-Fu
2014-05-08
Physic nut (Jatropha curcas L.) is a potential feedstock for biofuel production because Jatropha oil is highly suitable for the production of the biodiesel and bio-jet fuels. However, Jatropha exhibits low seed yield as a result of unreliable and poor flowering. FLOWERING LOCUS T (FT) -like genes are important flowering regulators in higher plants. To date, the flowering genes in Jatropha have not yet been identified or characterized. To better understand the genetic control of flowering in Jatropha, an FT homolog was isolated from Jatropha and designated as JcFT. Sequence analysis and phylogenetic relationship of JcFT revealed a high sequence similarity with the FT genes of Litchi chinensis, Populus nigra and other perennial plants. JcFT was expressed in all tissues of adult plants except young leaves, with the highest expression level in female flowers. Overexpression of JcFT in Arabidopsis and Jatropha using the constitutive promoter cauliflower mosaic virus 35S or the phloem-specific promoter Arabidopsis SUCROSE TRANSPORTER 2 promoter resulted in an extremely early flowering phenotype. Furthermore, several flowering genes downstream of JcFT were up-regulated in the JcFT-overexpression transgenic plant lines. JcFT may encode a florigen that acts as a key regulator in flowering pathway. This study is the first to functionally characterize a flowering gene, namely, JcFT, in the biofuel plant Jatropha.
... Avidan AY. Sleep and its disorders. In: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy SL, eds. Bradley's ... Rucker JC, Thurtell MJ. Cranial neuropathies. In: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy SL, eds. Bradley's ...
Cai, Li; Zhang, Lu; Fu, Qiantang; Xu, Zeng-Fu
2018-01-01
The seed oil of Jatropha curcas is considered a potential bioenergy source that could replace fossil fuels. However, the seed yield of Jatropha is low and has yet to be improved. We previously reported that exogenous cytokinin treatment increased the seed yield of Jatropha . Cytokinin levels are directly regulated by isopentenyl transferase (IPT), cytochrome P450 monooxygenase, family 735, subfamily A (CYP735A), and cytokinin oxidase/dehydrogenase (CKX). In this study, we cloned six IPT genes, one JcCYP735A gene, and seven JcCKX genes. The expression patterns of these 14 genes in various organs were determined using real-time quantitative PCR. JcIPT1 was primarily expressed in roots and seeds, JcIPT2 was expressed in roots, apical meristems, and mature leaves, JcIPT3 was expressed in stems and mature leaves, JcIPT5 was expressed in roots and mature leaves, JcIPT6 was expressed in seeds at 10 days after pollination, and JcIPT9 was expressed in mature leaves. JcCYP735A was mainly expressed in roots, flower buds, and seeds. The seven JcCKX genes also showed different expression patterns in different organs of Jatropha . In addition, CK levels were detected in flower buds and seeds at different stages of development. The concentration of N 6 -(Δ 2 -isopentenyl)-adenine (iP), iP-riboside, and trans -zeatin (tZ) increased with flower development, and the concentration of iP decreased with seed development, while that of tZ increased. We further analyzed the function of JcCYP735A using the CRISPR-Cas9 system, and found that the concentrations of tZ and tZ-riboside decreased significantly in the Jccyp735a mutants, which showed severely retarded growth. These findings will be helpful for further studies of the functions of cytokinin metabolic genes and understanding the roles of cytokinins in Jatropha growth and development.
Tang, Mingyong; Tao, Yan-Bin
2016-01-01
Jatropha curcas is a promising feedstock for biofuel production because Jatropha oil is highly suitable for the production of biodiesel and bio-jet fuels. However, Jatropha exhibits a low seed yield as a result of unreliable and poor flowering. APETALA1 (AP1) is a floral meristem and organ identity gene in higher plants. The flower meristem identity genes of Jatropha have not yet been identified or characterized. To better understand the genetic control of flowering in Jatropha, an AP1 homolog (JcAP1) was isolated from Jatropha. An amino acid sequence analysis of JcAP1 revealed a high similarity to the AP1 proteins of other perennial plants. JcAP1 was expressed in inflorescence buds, flower buds, sepals and petals. The highest expression level was observed during the early developmental stage of the flower buds. The overexpression of JcAP1 using the cauliflower mosaic virus (CaMV) 35S promoter resulted in extremely early flowering and abnormal flowers in transgenic Arabidopsis plants. Several flowering genes downstream of AP1 were up-regulated in the JcAP1-overexpressing transgenic plant lines. Furthermore, JcAP1 overexpression rescued the phenotype caused by the Arabidopsis AP1 loss-of-function mutant ap1-11. Therefore, JcAP1 is an ortholog of AtAP1, which plays a similar role in the regulation of flowering in Arabidopsis. However, the overexpression of JcAP1 in Jatropha using the same promoter resulted in little variation in the flowering time and floral organs, indicating that JcAP1 may be insufficient to regulate flowering by itself in Jatropha. This study helps to elucidate the function of JcAP1 and contributes to the understanding of the molecular mechanisms of flower development in Jatropha. PMID:27168978
Cai, Li; Zhang, Lu
2018-01-01
The seed oil of Jatropha curcas is considered a potential bioenergy source that could replace fossil fuels. However, the seed yield of Jatropha is low and has yet to be improved. We previously reported that exogenous cytokinin treatment increased the seed yield of Jatropha. Cytokinin levels are directly regulated by isopentenyl transferase (IPT), cytochrome P450 monooxygenase, family 735, subfamily A (CYP735A), and cytokinin oxidase/dehydrogenase (CKX). In this study, we cloned six IPT genes, one JcCYP735A gene, and seven JcCKX genes. The expression patterns of these 14 genes in various organs were determined using real-time quantitative PCR. JcIPT1 was primarily expressed in roots and seeds, JcIPT2 was expressed in roots, apical meristems, and mature leaves, JcIPT3 was expressed in stems and mature leaves, JcIPT5 was expressed in roots and mature leaves, JcIPT6 was expressed in seeds at 10 days after pollination, and JcIPT9 was expressed in mature leaves. JcCYP735A was mainly expressed in roots, flower buds, and seeds. The seven JcCKX genes also showed different expression patterns in different organs of Jatropha. In addition, CK levels were detected in flower buds and seeds at different stages of development. The concentration of N6-(Δ2-isopentenyl)-adenine (iP), iP-riboside, and trans-zeatin (tZ) increased with flower development, and the concentration of iP decreased with seed development, while that of tZ increased. We further analyzed the function of JcCYP735A using the CRISPR-Cas9 system, and found that the concentrations of tZ and tZ-riboside decreased significantly in the Jccyp735a mutants, which showed severely retarded growth. These findings will be helpful for further studies of the functions of cytokinin metabolic genes and understanding the roles of cytokinins in Jatropha growth and development. PMID:29785355
Campbell penetration depth in iron-based superconductors
NASA Astrophysics Data System (ADS)
Prommapan, Plengchart
2011-12-01
A "true" critical current density, jc, as opposite to commonly measured relaxed persistent (Bean) current, jB, was extracted from the Campbell penetration depth, lambda C(T, H) measured in single crystals of LiFeAs, and optimally electron-doped Ba (Fe0.954Ni 0.046)2As2 (FeNi122). In LiFeAs, the effective pinning potential is non-parabolic, which follows from the magnetic field - dependent Labusch parameter alpha. At the equilibrium (upon field - cooling), alpha( H) is non-monotonic, but it is monotonic at a finite gradient of the vortex density. This behavior leads to a faster magnetic relaxation at the lower fields and provides a natural dynamic explanation for the fishtail (second peak) effect. We also find the evidence for strong pinning at the lower fields.The inferred field dependence of the pinning potential is consistent with the evolution from strong pinning, through collective pinning, and eventually to a disordered vortex lattice. The value of j c (2 K) ≃ 1:22 x106 A/cm² provide an upper estimate of the current carrying capability of LiFeAs. Overall, vortex behavior of almost isotropic, fully-gapped LiFeAs is very similar to highly anisotropic d-wave cuprate superconductors, the similarity that requires further studies in order to understand unconventional superconductivity in cuprates and pnictides. In addition to LiFeAs, we also report the magnetic penetration depth in BaFe2As2 based superconductors including irradiation of FeNi122. In unirradiated FeNi122, the maximum critical current value is, jc(2 K) ≃ 3.3 x 106 A/cm². The magnetic-dependent feature was observed near the transition temperature in FeTe0.53Se0.47 and irradiated FeNi122. Because of this feature, further studies are required in order to properly calibrate the Campbell penetration depth. Finally, we detected the crossing between the magnetic penetration depth and London penetration depth in optimally hold-doped Ba0.6K 0.4Fe2As2 (BaK122) and isovalent doped BaFe2(As0.7P0.3)2 (BaP122). These phenomena probably coincide with anomalous Meissner effect reported in pnictide superconductors [Prozorov et al. (2010b)] however more studies are needed in order to clarify this.
Sarmiento, Carolina; Zalamea, Paul-Camilo; Dalling, James W; Davis, Adam S; Stump, Simon M; U'Ren, Jana M; Arnold, A Elizabeth
2017-10-24
The Janzen-Connell (JC) hypothesis provides a conceptual framework for explaining the maintenance of tree diversity in tropical forests. Its central tenet-that recruits experience high mortality near conspecifics and at high densities-assumes a degree of host specialization in interactions between plants and natural enemies. Studies confirming JC effects have focused primarily on spatial distributions of seedlings and saplings, leaving major knowledge gaps regarding the fate of seeds in soil and the specificity of the soilborne fungi that are their most important antagonists. Here we use a common garden experiment in a lowland tropical forest in Panama to show that communities of seed-infecting fungi are structured predominantly by plant species, with only minor influences of factors such as local soil type, forest characteristics, or time in soil (1-12 months). Inoculation experiments confirmed that fungi affected seed viability and germination in a host-specific manner and that effects on seed viability preceded seedling emergence. Seeds are critical components of reproduction for tropical trees, and the factors influencing their persistence, survival, and germination shape the populations of seedlings and saplings on which current perspectives regarding forest dynamics are based. Together these findings bring seed dynamics to light in the context of the JC hypothesis, implicating them directly in the processes that have emerged as critical for diversity maintenance in species-rich tropical forests.
An aging effect and its origin in GdBCO thin films
NASA Astrophysics Data System (ADS)
Schlesier, K.; Huhtinen, H.; Granroth, S.; Paturi, P.
2010-06-01
An aging effect investigation was made for GdBa2Cu3O7 (GdBCO) thin films grown on SrTiO3 (001) substrates with pulsed laser deposition (PLD) method from nanograined targets. The films were cut into two pieces where one piece was coated with gold cap layer while the other was left without coating. Both pieces were kept in ambient air during the half year measurement period. Magnetization measurements as well as phase purity, lattice parameter, oxygen effect and depth structure determination with x-ray diffraction (XRD) were made in one month interval. For structure and oxygen content, x-ray photoelectron spectroscopy measurements (XPS) were done in the beginning and in the end of the period. A reduction of the critical temperature and the critical current density, Jc, was found in the gold coated GdBCO film in ambient air in course of time. A smaller decrease of Jc was detected in uncoated GdBCO. No development of impurity phase, increase of a-orientation or reduction of the pinning structure was detected in uncoated GdBCO. However, a small development of impurity phase was found in gold coated GdBCO. The diminution of Tc and Jc is concluded to originate from oxygen release. No such a phenomenon was found in YBa2Cu3O7. We conclude that gold is not a proper cap layer at least for some applications.
Effect of cubic equiaxed grains and its Ti-stabilizing performance in Nb3Sn strands
NASA Astrophysics Data System (ADS)
Chaowu, Zhang; Lian, Zhou; Sulpice, Andre; Soubeyroux, Jean-Louis; Xiande, Tang; Verwaerde, Christophe; Hoang, Gia Ky
2009-06-01
Two kinds of multifilament internal-Sn Nb3Sn superconducting strands were fabricated through the RRP method, one with 2 wt% of Ti alloyed in an Sn core and the other just pure Sn. Four reaction temperatures of 650, 675, 700 and 725 °C and 128 h duration were applied for A15 phase formation heat treatment after a Cu-Sn alloying procedure of 210 °C/50 h+340 °C/25 h. Through the standard four-probe technique the heat-treated coil samples were examined for the transport non-Cu JC variation with applied field B which was then used to calculate the flux pinning force variation FP-B. The samples' phase microstructure were also observed by means of FESEM. The obtained results demonstrate that for fully reacted Nb3Sn superconductors the transport critical current density JC is more importantly affected by the cubic equiaxed morphology than by grain dimension, due to its much stronger flux pinning performance of the morphology. Ti addition in Sn stabilizes the cubic equiaxed grains at lower reaction temperature so that the HT temperature is effectively reduced, the flux pinning strength is largely reinforced and thus the transport non-Cu JC is substantially promoted. Funds: this research project was supported by the France-China Collaboration Research contract CNRS no. 722441 and the SUST doctoral foundation BJ07-07.
Spin generation by strong inhomogeneous electric fields
NASA Astrophysics Data System (ADS)
Finkler, Ilya; Engel, Hans-Andreas; Rashba, Emmanuel; Halperin, Bertrand
2007-03-01
Motivated by recent experiments [1], we propose a model with extrinsic spin-orbit interaction, where an inhomogeneous electric field E in the x-y plane can give rise, through nonlinear effects, to a spin polarization with non-zero sz, away from the sample boundaries. The field E induces a spin current js^z= z x(αjc+βE), where jc=σE is the charge current, and the two terms represent,respectively, the skew scattering and side-jump contributions. [2]. The coefficients α and β are assumed to be E- independent, but conductivity σ is field dependent. We find the spin density sz by solving the equation for spin diffusion and relaxation with a source term ∇.js^z. For sufficiently low fields, jc is linear in E, and the source term vanishes, implying that sz=0 away from the edges. However, for large fields, σ varies with E. Solving the diffusion equation in a T-shaped geometry, where the electric current propagates along the main channel, we find spin accumulation near the entrance of the side channel, similar to experimental findings [1]. Also, we present a toy model where spin accumulation away from the boundary results from a nonlinear and anisotropic conductivity. [1] V. Sih, et al, Phys. Rev. Lett. 97, 096605 (2006). [2] H.-A. Engel, B.I. Halperin, E.I.Rashba, Phys. Rev. Lett. 95, 166605 (2005).
Transcriptome analysis of Jatropha curcas L. flower buds responded to the paclobutrazol treatment.
Seesangboon, Anupharb; Gruneck, Lucsame; Pokawattana, Tittinat; Eungwanichayapant, Prapassorn Damrongkool; Tovaranonte, Jantrararuk; Popluechai, Siam
2018-06-01
Jatropha seeds can be used to produce high-quality biodiesel due to their high oil content. However, Jatropha produces low numbers of female flowers, which limits seed yield. Paclobutrazol (PCB), a plant growth retardant, can increase number of Jatropha female flowers and seed yield. However, the underlying mechanisms of flower development after PCB treatment are not well understood. To identify the critical genes associated with flower development, the transcriptome of flower buds following PCB treatment was analyzed. Scanning Electron Microscope (SEM) analysis revealed that the flower developmental stage between PCB-treated and control flower buds was similar. Based on the presence of sex organs, flower buds at 0, 4, and 24 h after treatment were chosen for global transcriptome analysis. In total, 100,597 unigenes were obtained, 174 of which were deemed as interesting based on their response to PCB treatment. Our analysis showed that the JcCKX5 and JcTSO1 genes were up-regulated at 4 h, suggesting roles in promoting organogenic capacity and ovule primordia formation in Jatropha. The JcNPGR2, JcMGP2-3, and JcHUA1 genes were down-regulated indicating that they may contribute to increased number of female flowers and amount of seed yield. Expression of cell division and cellulose biosynthesis-related genes, including JcGASA3, JcCycB3;1, JcCycP2;1, JcKNAT7, and JcCSLG3 was decreased, which might have caused the compacted inflorescences. This study represents the first report combining SEM-based morphology, qRT-PCR and transcriptome analysis of PCB-treated Jatropha flower buds at different stages of flower development. Copyright © 2018 Elsevier Masson SAS. All rights reserved.
Arslan-Alaton, Idil; Kabdaşli, Işik; Vardar, Burcu; Tünay, Olcay
2009-05-30
Reactive dyebath effluents are ideal candidates for electrocoagulation due to their intensive color, medium strength, recalcitrant COD and high electrolyte (NaCl) content. The present study focused on the treatability of simulated reactive dyebath effluent (COD(o)=300 mg/L; color in terms of absorbance values A(o,436)=0.532 cm(-1), A(o,525)=0.693 cm(-1) and A(o,620)=0.808 cm(-1)) employing electrocoagulation with aluminum and stainless steel electrodes. Optimization of critical operating parameters such as initial pH (pH(o) 3-11), applied current density (J(c)=22-87 mA/cm(2)) and electrolyte type (NaCl or Na(2)SO(4)) improved the overall treatment efficiencies resulting in effective decolorization (99% using stainless steel electrodes after 60 min, 95% using aluminum electrodes after 90 min electrocoagulation) and COD abatement (93% with stainless steel electrodes after 60 min, 86% with aluminum electrodes after 90 min of reaction time). Optimum electrocoagulation conditions were established as pH(o) 5 and J(c)=22 mA/cm(2) for both electrode materials. The COD and color removal efficiencies also depended on the electrolyte type. No in situ, surplus adsorbable organically bound halogens (AOX) formation associated with the use of NaCl as the electrolyte during electrocoagulation was detected. An economical evaluation was also carried out within the frame of the study. It was demonstrated that electrocoagulation of reactive dyebath effluent with aluminum and stainless steel electrodes was a considerably less electrical energy-intensive, alternative treatment method as compared with advanced chemical oxidation techniques.
Diffusion studies and critical current in superconducting Nb-Ti-Ta artificial pinning center wire
NASA Astrophysics Data System (ADS)
Bormio-Nunes, C.; Gomes, P. M. N.; Tirelli, M. A.; Ghivelder, L.
2005-08-01
The diffusion between Nb-20%Ta (wt %) and pure Ti is studied at temperatures of 973, 1023, and 1073K, for duration times among 25 and 121h in an artificial pinning center (APC) wire composed of a Ti core surrounded by a Nb-20%Ta layer. The produced diffusion layer is a ternary alloy with superconducting properties, such as critical field Bc2 and critical current density JC, which intrinsically depend on the layer composition. Measurements of layer morphology and composition were performed, and the results show a preferential diffusion of Nb and Ta into Ti. There is a slight diffusion of Ti into Nb through grain boundaries. The presence of Ta also slows down the diffusion of Nb in Ti if compared to the couple formed by pure Nb and Ti. Regarding the mechanical properties of the composite wire, the use of lower temperatures to form the ternary phase is desirable in order to avoid a larger portion of the diffusion layer rich in Ti that favorites α-Ti precipitations that are detrimental to the wire ductility. The best JC value was obtained for the sample heat treated at 973K. The improvement of the flux-line pinning was associated with a sharp change of the diffusion layer composition rather than pinning by normal layer interfaces, suggesting a new source of pinning in this kind of material. Nb-Ti-Ta ternary alloys have the potential to be used in superconducting magnets when fields above 12T are required.
Fan, Jian; Zhuang, Yongliang; Li, Bafang
2013-01-17
Jellyfish collagen (JC) was extracted from jellyfish umbrella and hydrolyzed to prepare jellyfish collagen hydrolysate (JCH). The effects of JC and JCH on UV-induced skin damage of mice were evaluated by the skin moisture, microscopic analyses of skin and immunity indexes. The skin moisture analyses showed that moisture retention ability of UV-induced mice skin was increased by JC and JCH. Further histological analysis showed that JC and JCH could repair the endogenous collagen and elastin protein fibers, and could maintain the natural ratio of type I to type III collagen. The immunity indexes showed that JC and JCH play a role in enhancing immunity of photoaging mice in vivo. JCH showed much higher protective ability than JC. These results suggest that JCH as a potential novel antiphotoaging agent from natural resources.
2014-01-01
Background Physic nut (Jatropha curcas L.) is a potential feedstock for biofuel production because Jatropha oil is highly suitable for the production of the biodiesel and bio-jet fuels. However, Jatropha exhibits low seed yield as a result of unreliable and poor flowering. FLOWERING LOCUS T (FT) –like genes are important flowering regulators in higher plants. To date, the flowering genes in Jatropha have not yet been identified or characterized. Results To better understand the genetic control of flowering in Jatropha, an FT homolog was isolated from Jatropha and designated as JcFT. Sequence analysis and phylogenetic relationship of JcFT revealed a high sequence similarity with the FT genes of Litchi chinensis, Populus nigra and other perennial plants. JcFT was expressed in all tissues of adult plants except young leaves, with the highest expression level in female flowers. Overexpression of JcFT in Arabidopsis and Jatropha using the constitutive promoter cauliflower mosaic virus 35S or the phloem-specific promoter Arabidopsis SUCROSE TRANSPORTER 2 promoter resulted in an extremely early flowering phenotype. Furthermore, several flowering genes downstream of JcFT were up-regulated in the JcFT-overexpression transgenic plant lines. Conclusions JcFT may encode a florigen that acts as a key regulator in flowering pathway. This study is the first to functionally characterize a flowering gene, namely, JcFT, in the biofuel plant Jatropha. PMID:24886195
Free flux flow: a probe into the field dependence of vortex core size in clean single crystals
NASA Astrophysics Data System (ADS)
Gapud, A. A.; Gafarov, O.; Moraes, S.; Thompson, J. R.; Christen, D. K.; Reyes, A. P.
2012-02-01
The free-flux-flow (FFF) phase has been attained successfully in a number of clean, weak-pinning, low-anisotropy, low-Tc, single-crystal samples as a unique probe into type II superconductivity that is independent of composition. The ``clean'' quality of the samples have been confirmed by reversible magnetization, high residual resistivity ratio, and low critical current densities Jc with a re-entrant ``peak'' effect in Jc(H) just below the critical field Hc2. The necessity of high current densities presented technical challenges that had been successfully addressed, and FFF is confirmed by a field-dependent ohmic state that is also well below the normal state. In these studies, the FFF resistivity ρf(H) has been measured in order to observe the field-dependent core size of the quantized magnetic flux vortices as modeled recently by Kogan and Zelezhina (KZ) who predicted a specific deviation from Bardeen-Stephen flux flow, dependent on normalized temperature and scattering parameter λ. The compounds studied are: V3Si, LuNi2B2C, and NbSe2, and results have shown consistency with the KZ model. Other applications of this method could also be used to probe normal-state properties, especially for the new iron arsenides, as will be discussed.
Fan, Jian; Zhuang, Yongliang; Li, Bafang
2013-01-01
Jellyfish collagen (JC) was extracted from jellyfish umbrella and hydrolyzed to prepare jellyfish collagen hydrolysate (JCH). The effects of JC and JCH on UV-induced skin damage of mice were evaluated by the skin moisture, microscopic analyses of skin and immunity indexes. The skin moisture analyses showed that moisture retention ability of UV-induced mice skin was increased by JC and JCH. Further histological analysis showed that JC and JCH could repair the endogenous collagen and elastin protein fibers, and could maintain the natural ratio of type I to type III collagen. The immunity indexes showed that JC and JCH play a role in enhancing immunity of photoaging mice in vivo. JCH showed much higher protective ability than JC. These results suggest that JCH as a potential novel antiphotoaging agent from natural resources. PMID:23344251
A Computer Program for the Preliminary Design of Contrarotating Propellers
1975-12-01
10 062, 10 030’t .0b03 10062 Nt:=42,1 03Q 20030 MNNiJC 79 Lv L=M-1 SP:S IN (FLOAT (L) *8 (N, ID) AZL=AZLOCON1#CMP (Mtg)*SKF 20038 BZL=BZL*CONi...81,82vJC1 Pm1=.IMPUN(t31 BI.,JC) PP 5 P P2/PP 3 9D06=SjNPUN(R1q8OJN~ P*7:sIP4PUN(dl s8 ,JC) P0d=S IMPUN(81,E39tJC) F’P9=PF / PB n~o 1C09 I:1,JC 03 10940 L=1...0 )r) =Y ( D) no? J:1,v4 IF (A) l1 t :-(XA-Ytjl)AC 3SU"=:SUMOPROt) A NS=S U* Copy brkabdlo to DDC does not pb ;ml fully ICYNGl reproduction -7-707 44
Sources of zodiacal dust particles
NASA Astrophysics Data System (ADS)
Ipatov, S. I.; Mather, J. C.
2007-08-01
The orbital evolution of dust particles produced by asteroids, comets, and trans- Neptunian objects was integrated [1-3]. Analysis of results of these integrations testify in favor of a considerable fraction of particles produced by comets among overall zodiacal dust particles, but it does not contradict to >30% of asteroidal dust needed for explanation of formation of dust bands. Fractions of asteroidal particles, particles originating beyond Jupiter's orbit (including trans-Neptunian particles), and cometary particles originating inside of Jupiter's orbit are estimated to be about 1/3 each, with a possible deviation from 1/3 up to 0.1-0.2. Comparison of the plots of the number density vs. the distance R from the Sun obtained for particles produced by different small bodies with the plots based on observations shows that asteroidal and trans- Neptunian particles alone can not explain the observed almost constant number density at R ∼3-18 AU and a lot of particles must be produced by comets at R ∼5-10 AU [2-3]. Comparison of the WHAM (Wisconsin H-Alpha Mapper spectrometer) observations of spectra of zodiacal light with our models showed [4-5] that a significant fraction of particles produced by short-period comets is required to fit the observations of the width and velocity of the Mg I line. Comparison of the observations of the number density inside Jupiter's orbit with the number density of particles produced by different small bodies leads to the same conclusion about a considerable fraction of cometary particles. This comparison does not make limitations on cometary particles produced beyond Jupiter's orbit, but it shows that the fraction of particles produced by Encke-type comets (with eccentricities ∼0.8-0.9) does not exceed 0.15 of the overall population. The estimated fraction of particles produced by long-period and Halley-type comets among zodiacal dust also does not exceed 0.1-0.15. Though trans-Neptunian particles fit different observations of dust inside Jupiter's orbit, they can not be dominant in the zodiacal cloud because they can not be dominant between orbits of Jupiter and Saturn. The conclusion on a considerable fraction of cometary dust is also in an agreement with our studies [6] of the dynamics of Jupiter-family comets, which showed that some former cometary objects could get high eccentric orbits located entirely inside of Jupiter's orbit and stay in these orbits for a long time. Some of these objects could disintegrate producing a substantial amount of dust. [1] Ipatov S.I., Mather J.C., and Taylor P. (2004) Annals of the New York Acad. of Sciences, 1017, 66-80. [2] Ipatov S.I. and Mather J.C. (2006) Advances in Space Research, 37, 126-137. [3] Ipatov S.I. and Mather J.C., (2007) Dust in Planetary Systems, ed. by H. Krüger and A. Graps, ESA Publications, SP-643, p. 91-94. [4] Ipatov S.I. et al. (2006) 37th LPSC, #1471. [5] Ipatov S.I. et al., astro-ph/0608141. [6] Ipatov S.I. and Mather J.C. (2004) Annals of the New York Acad. of Sciences, 1017, 66-80.
Thermally activated flux flow in FeSe0.5Te0.5 superconducting single crystal
NASA Astrophysics Data System (ADS)
Hamad, R. M.; Kayed, T. S.; Kunwar, S.; Ziq, Kh A.
2017-07-01
The current-voltage (J-E) isotherms of single crystal FeSe0.5Te0.5 sample have been measured at several temperatures near the transition temperature (Tc) and under applied magnetic fields (H). A power law (E ˜ Jβ ) has been used to fit the data and evaluate the activation energy Uo (T) using β = Uo/kBT. At low current density (J << Jc), the initial behaviour is associated with thermally activated flux Flow (TAFF) while at J >> Jc vortex flux flow (FF) behavior is expected. The effects of applied magnetic field on FF and TAFF also been investigated. We found that Uo(FF) was reduced with by about an order of magnitude in magnetic fields as low as ˜1.5 Tesla-the reduction in Uo(TAFF) is even faster than in Uo(FF)-hence reflecting the low pinning nature (defects, vacancies etc.) of FeSe0.5Te0.5 superconductor.
Second cluster integral from the spectrum of an infinite XXZ spin chain
NASA Astrophysics Data System (ADS)
Bibikov, P. N.
2015-03-01
First and second terms of the low-temperature cluster expansion for the free energy density of a magnetically polarized XXZ spin chain is obtained within the propagator approach suggested by E.W. Montroll and J.C. Ward. All the calculations employ only one- and two-magnon infinite-chain spectrums. In the XXX-point the result reproduces the well known S. Katsura's formula obtained 50 years ago by finite-chain calculations.
Electronic Materials and Applications 2014 (Abstracts)
2015-04-02
the thermal image using IR camera and surface tempera- ture using thermo couple. Lastly, we conducted a surface coating to change the surface...progress in the superconducting films and coated conductors of iron chalcogenides. With a CeO2 buffer , critical current densities (Jc) over 7 MA/cm2...Roosen, University of Erlangen-Nuremberg, Germany Kato, N. 23-Jan 11:15AM Pacific 11:30 AM (EMA-S1-021-2014) Glass-like Thermal Conductivity of (010
Chryseobacterium salipaludis sp. nov., isolated at a wild ass sanctuary.
Divyasree, B; Suresh, G; Sasikala, Ch; Ramana, Ch V
2018-02-01
A Gram-stain-negative, rod-shaped, non-motile, aerobic bacterium was isolated from a sediment sample obtained from a wild ass sanctuary in Gujarat, India. The strain designated JC490 T was oxidase- and catalase-positive. The 16S rRNA gene sequence analysis and sequence comparison data indicated that strain JC490 T was a member of the genus Chryseobacterium and was closely related to Chryseobacterium jeonii AT1047 T (96.4 %) and with other members of the genus Chryseobacterium (<96.3 %). The DNA G+C content of strain JC490 T was 34 mol%. Strain JC490 T had phosphatidylethanolamine, two unidentified aminolipids, two unidentified phospholipids and five unidentified polar lipids. Menaquinone-6 was the only respiratory quinone found. Iso-C15 : 0, anteiso-C15 : 0 and iso-C17 : 0 3-OH were the major fatty acids of strain JC490 T . On the basis of physiological, genotypic, phylogenetic and chemotaxonomic analyses, it is concluded that strain JC490 T constitutes a novel species of the genus Chryseobacterium, for which the name Chryseobacterium salipaludis sp. nov. is proposed. The type strain is JC490 T (=KCTC 52835 T =LMG 30048 T ).
Transformation of Primary Hamster Brain Cells with JC Virus and Its DNA
Frisque, R. J.; Rifkin, D. B.; Walker, D. L.
1980-01-01
We transformed primary hamster brain cells with four isolates of JC virus and JC virus DNA. Several properties of these transformants were characterized and compared to those of simian virus 40 transformants isolated under identical conditions. Images PMID:6251275
Tao, Yan-Bin; He, Liang-Liang; Niu, Longjian; Xu, Zeng-Fu
2016-08-01
The 1.5 kb JcAP1 promoter from the biofuel plant Jatropha curcas is predominantly active in the inflorescence buds of transgenic plants, in which the -1313/-1057 region is essential for maintaining the activity. Arabidopsis thaliana APETALA1 (AP1) is a MADS-domain transcription factor gene that functions primarily in flower development. We isolated a homolog of AP1 from Jatropha curcas (designated JcAP1), which was shown to exhibit flower-specific expression in Jatropha. JcAP1 is first expressed in inflorescence buds and continues to be primarily expressed in the sepals. We isolated a 1.5 kb JcAP1 promoter and evaluated its activity in transgenic Arabidopsis and Jatropha using the β-glucuronidase (GUS) reporter gene. In transgenic Arabidopsis and Jatropha, the inflorescence buds exhibited notable GUS activity, whereas the sepals did not. Against expectations, the JcAP1 promoter was active in the anthers of Arabidopsis and Jatropha and was highly expressed in Jatropha seeds. An analysis of promoter deletions in transgenic Arabidopsis revealed that deletion of the -1313/-1057 region resulted in loss of JcAP1 promoter activity in the inflorescence buds and increased activity in the anthers. These results suggested that some regulatory sequences in the -1313/-1057 region are essential for maintaining promoter activity in inflorescence buds and can partly suppress activity in the anthers. Based on these findings, we hypothesized that other elements located upstream of the 1.5 kb JcAP1 promoter may be required for flower-specific activation. The JcAP1 promoter characterized in this study can be used to drive transgene expression in both the inflorescence buds and seeds of Jatropha.
Tao, Yan-Bin; He, Liang-Liang; Niu, Long-Jian; Xu, Zeng-Fu
2015-04-01
The JcUEP promoter is active constitutively in the bio-fuel plant Jatropha curcas , and is an alternative to the widely used CaMV35S promoter for driving constitutive overexpression of transgenes in Jatropha. Well-characterized promoters are required for transgenic breeding of Jatropha curcas, a biofuel feedstock with great potential for production of bio-diesel and bio-jet fuel. In this study, an ubiquitin extension protein gene from Jatropha, designated JcUEP, was identified to be ubiquitously expressed. Thus, we isolated a 1.2 kb fragment of the 5' flanking region of JcUEP and evaluated its activity as a constitutive promoter in Arabidopsis and Jatropha using the β-glucuronidase (GUS) reporter gene. As expected, histochemical GUS assay showed that the JcUEP promoter was active in all Arabidopsis and Jatropha tissues tested. We also compared the activity of the JcUEP promoter with that of the cauliflower mosaic virus 35S (CaMV35S) promoter, a well-characterized constitutive promoter conferring strong transgene expression in dicot species, in various tissues of Jatropha. In a fluorometric GUS assay, the two promoters showed similar activities in stems, mature leaves and female flowers; while the CaMV35S promoter was more effective than the JcUEP promoter in other tissues, especially young leaves and inflorescences. In addition, the JcUEP promoter retained its activity under stress conditions in low temperature, high salt, dehydration and exogenous ABA treatments. These results suggest that the plant-derived JcUEP promoter could be an alternative to the CaMV35S promoter for driving constitutive overexpression of transgenes in Jatropha and other plants.
MgB2 wire diameter reduction by hot isostatic pressing—a route for enhanced critical current density
NASA Astrophysics Data System (ADS)
Morawski, A.; Cetner, T.; Gajda, D.; Zaleski, A. J.; Häßler, W.; Nenkov, K.; Rindfleisch, M. A.; Tomsic, M.; Przysłupski, P.
2018-07-01
The effect of wire diameter reduction on the critical current density of pristine MgB2 wire was studied. Wires were treated by a hot isostatic pressing method at 570 °C and at pressures of up to 1.1 GPa. It was found that the wire diameter reduction induces an increase of up to 70% in the mass density of the superconducting cores. This feature leads to increases in critical current, critical current density, and pinning force density. The magnitude and field dependence of the critical current density are related to both grain connectivity and structural defects, which act as effective pinning centers. High field transport properties were obtained without doping of the MgB2 phase. A critical current density jc of 3500 A mm‑2 was reached at 4 K, 6 T for the best sample, which was a five-fold increase compared to MgB2 samples synthesized at ambient pressure.
Behavior of cellulose-degrading bacteria in thermophilic anaerobic digestion process.
Syutsubo, K; Nagaya, Y; Sakai, S; Miya, A
2005-01-01
Previously, we found that the newly isolated Clostridium sp. strain JC3 became the dominant cellulose-degrading bacterium in thermophilic methanogenic sludge. In the present study, the behavior of strain JC3 in the thermophilic anaerobic digestion process was investigated quantitatively by molecular biological techniques. A cellulose-degrading experiment was conducted at 55 degrees C with a 9.5 L of anaerobic baffled reactor having three compartments (Nos. 1, 2, 3). Over 80% of the COD input was converted into methane when 2.5 kgCOD m(-3) d(-1) was loaded for an HRT of 27 days. A FISH probe specific for strain JC3 was applied to sludge samples harvested from the baffled reactor. Consequently, the ratio of JC3 cells to DAPI-stained cells increased from below 0.5% (undetectable) to 9.4% (compartment 1), 13.1% (compartment 2) and 21.6% (compartment 3) at day 84 (2.5 kgCOD m(-3)d(-1)). The strain JC3 cell numbers determined by FISH correlated closely with the cellulose-degrading methanogenic activities of retained sludge. A specific primer set targeting the cellulase gene (cellobiohydrolaseA: cbhA) of strain JC3 was designed and applied to digested sludge for treating solid waste such as coffee grounds, wastepaper, garbage, cellulose and so on. The strain JC3 cell numbers determined by quantitative PCR correlated closely with the cellulose-sludge loading of the thermophilic digester. Strain JC3 is thus important in the anaerobic hydrolysis of cellulose in thermophilic anaerobic digestion processes.
Redesigning journal club in residency.
Al Achkar, Morhaf
2016-01-01
The gap between production and implementation of knowledge is the main reason for the suboptimal quality of health care. To eliminate this gap and improve the quality of patient care, journal club (JC) in graduate medical education provides an opportunity for learning the skills of evidence-based medicine. JC, however, continues to face many challenges mainly due to poorly defined goals, inadequate preparation, and lack of interest. This article presents an innovative model to prepare and present JC based on three pillars: dialogical learning through group discussion, mentored residents as peer teachers, and including JC as part of a structured curriculum to learn evidence-based medicine. This engaging model has the potential to transform JC from a moribund session that is daunting for residents into a lively discussion to redefine clinical practice using the most current evidence.
Wang, Peipei; Li, Jing; Gao, Xiaoyang; Zhang, Di; Li, Anlin; Liu, Changning
2018-05-29
Physic nut ( Jatropha curcas L.) is a species of flowering plant with great potential for biofuel production and as an emerging model organism for functional genomic analysis, particularly in the Euphorbiaceae family. DNA binding with one finger (Dof) transcription factors play critical roles in numerous biological processes in plants. Nevertheless, the knowledge about members, and the evolutionary and functional characteristics of the Dof gene family in physic nut is insufficient. Therefore, we performed a genome-wide screening and characterization of the Dof gene family within the physic nut draft genome. In total, 24 JcDof genes (encoding 33 JcDof proteins) were identified. All the JcDof genes were divided into three major groups based on phylogenetic inference, which was further validated by the subsequent gene structure and motif analysis. Genome comparison revealed that segmental duplication may have played crucial roles in the expansion of the JcDof gene family, and gene expansion was mainly subjected to positive selection. The expression profile demonstrated the broad involvement of JcDof genes in response to various abiotic stresses, hormonal treatments and functional divergence. This study provides valuable information for better understanding the evolution of JcDof genes, and lays a foundation for future functional exploration of JcDof genes.
Lizarondo, Lucylynn M; Grimmer-Somers, Karen; Kumar, Saravana
2011-09-23
Research evidence suggests that journal clubs (JCs) are one approach which can be used to bridge the gap between research and clinical practice. However, there are issues which potentially threaten their viability such as on-going participation or compliance with attendance, which require further exploration. The objectives of this study are: to explore the views and perspectives of allied health practitioners (AHPs) regarding the use of any type of JC in promoting evidence-based practice (EBP); to identify ways in which an innovative model of JC developed by the International Centre for Allied Health Evidence (iCAHE) might be refined. A qualitative descriptive study utilising focus group interviews with various groups of AHP was undertaken-- those who have been exposed to the iCAHE JC model and those who have no experience of the iCAHE model (although they may have had exposure to other forms of JC). Maximum variation sampling was used to recruit participants for the study. Transcripts of focus groups were coded and distilled into content-related categories. Six focus groups with 39 AHPs were facilitated. Allied health practitioners perspectives' on JCs were classified in five broad categories: utility and benefits of a JC, elements of an effective and sustainable JC, barriers to participation, incentives for participation, and opportunities for improvement in the current iCAHE JC model. Overall, JCs were seen as a forum for reflective practice and keeping up-to-date with research evidence, and a venue for learning the processes involved in critical appraisal. Limited knowledge of statistics and heavy clinical workload were reported as barriers to participation in a JC. Strategies such as mentoring, strong support from managers, and providing CPD (continuing professional development) points can potentially address these barriers. Opportunities for refinement of the current iCAHE model were raised. This study suggests that a structured model of JC such as iCAHE's model is acceptable, and likely to be used with enthusiasm by AHP to achieve EBP. Future research should explore the impact of iCAHE JC compared with no JC exposure, and other forms of exposure to JCs, in influencing change in allied health practitioners behaviours and evidence implementation.
Functional characterization of two microsomal fatty acid desaturases from Jatropha curcas L.
Wu, Pingzhi; Zhang, Sheng; Zhang, Lin; Chen, Yaping; Li, Meiru; Jiang, Huawu; Wu, Guojiang
2013-10-15
Linoleic acid (LA, C18:2) and α-linolenic acid (ALA, C18:3) are polyunsaturated fatty acids (PUFAs) and major storage compounds in plant seed oils. Microsomal ω-6 and ω-3 fatty acid (FA) desaturases catalyze the synthesis of seed oil LA and ALA, respectively. Jatropha curcas L. seed oils contain large proportions of LA, but very little ALA. In this study, two microsomal desaturase genes, named JcFAD2 and JcFAD3, were isolated from J. curcas. Both deduced amino acid sequences possessed eight histidines shown to be essential for desaturases activity, and contained motif in the C-terminal for endoplasmic reticulum localization. Heterologous expression in Saccharomyces cerevisiae and Arabidopsis thaliana confirmed that the isolated JcFAD2 and JcFAD3 proteins could catalyze LA and ALA synthesis, respectively. The results indicate that JcFAD2 and JcFAD3 are functional in controlling PUFA contents of seed oils and could be exploited in the genetic engineering of J. curcas, and potentially other plants. Copyright © 2013 Elsevier GmbH. All rights reserved.
Correlation function for generalized Pólya urns: Finite-size scaling analysis
NASA Astrophysics Data System (ADS)
Mori, Shintaro; Hisakado, Masato
2015-11-01
We describe a universality class for the transitions of a generalized Pólya urn by studying the asymptotic behavior of the normalized correlation function C (t ) using finite-size scaling analysis. X (1 ),X (2 ),... are the successive additions of a red (blue) ball [X (t )=1 (0 )] at stage t and C (t )≡Cov[X (1 ),X (t +1 )]/Var[X (1 )] . Furthermore, z (t ) =∑s=1tX (s ) /t represents the successive proportions of red balls in an urn to which, at the (t +1 )th stage, a red ball is added [X (t +1 )=1 ] with probability q [z (t )]=(tanh{J [2 z (t )-1 ]+h }+1 )/2 ,J ≥0 , and a blue ball is added [X (t +1 )=0 ] with probability 1 -q [z (t )] . A boundary [Jc(h ) ,h ] exists in the (J ,h ) plane between a region with one stable fixed point and another region with two stable fixed points for q (z ) . C (t ) ˜c +c'.tl -1 with c =0 (>0 ) for J
NASA Astrophysics Data System (ADS)
Grajales-Nishimura, José Manuel; Ramos-Arias, Mario Alfredo; Solari, Luigi; Murillo-Muñetón, Gustavo; Centeno-García, Elena; Schaaf, Peter; Torres-Vargas, Ricardo
2018-04-01
The Juchatengo complex (JC) suite is located between the Proterozoic Oaxacan complex to the north and the Xolapa complex to the south, and was amalgamated by late Paleozoic magmatism. It consists of mafic and sedimentary rocks that have oceanic affinities, with internal pseudostratigraphic, structural and metamorphic characteristics, which resemble a typical upper-level ophiolite assemblage. New U-Pb zircon and previous hornblende K-Ar analyses yield ages of ca. 291-313 Ma (U-Pb) for plagiogranites and ca. 282-277 Ma for tonalites intruding the entire sequence, including pelagic sediments at the top, with a maximum deposition age of ca. 278 Ma and noteworthy local provenance. These data constrain the age of the JC to the Late Pennsylvanian-Early Permian period. Hf isotopic analyses obtained from zircons in the JC plagiogranite and tonalite show that they come from a similar primitive mantle source (176Hf/177Hf: 0.282539-0.283091; ƐHf(t): + 3.2 to + 15.0). ƐHf(t) values from near 0 to - 2.8 in the tonalites indicate a contribution from the continental crust. Trace elements and REE patterns in whole rock and zircons point to a primitive mantle source for differentiated mafic, plagiogranite dykes and tonalitic plutons. Geochronological and geochemical data address the generation of new oceanic crust above the subduction zone, probably in a backarc setting. In this tectonic scenario, the JC ophiolite originated due to the convergence of the paleo-Pacific plate below the already integrated Oaxacan and Acatlán complexes in western Pangea. The dextral displacement places the deformation in a transtensional regime during the late Paleozoic age.
Microstructural study of brass matrix internal tin multifilamentary Nb3Sn superconductors
NASA Astrophysics Data System (ADS)
Banno, Nobuya; Miyamoto, Yasuo; Tachikawa, Kyoji
2018-03-01
Zn addition to the Cu matrix in internal-tin-processed Nb3Sn superconductors is attractive in terms of the growth kinetics of the Nb3Sn layers. Sn activity is enhanced in the Cu-Zn (brass) matrix, which accelerates Nb3Sn layer formation. Here, we prepared multifilamentary wires using a brass matrix with a Nb core diameter of less than 10 μm and investigated the potential for further Jc improvement through microstructural and microchemical studies. Ti was added into the Sn cores in the precursor wire. Microchemical analysis showed that Ti accumulates between subelements consisting of Nb cores, which blocks Sn diffusion through this region when the spacing between the subelements in the precursor wire is a few microns. The average grain size was found to be about 230 nm through image analysis. To date, matrix Jc values of 1470 and 640 A/mm-2 have been obtained at 12 and 16 T, respectively. The area fraction of Nb cores in the filamentary region of the precursor wire was about 36.3%. There was still some unreacted Nb core area after heat treatment. Insufficient Ti diffusion into the Nb3Sn layers was identified in the outer subelements. These findings suggest that there is still room for improvement in Jc.
Flow behaviour and constitutive modelling of a ferritic stainless steel at elevated temperatures
NASA Astrophysics Data System (ADS)
Zhao, Jingwei; Jiang, Zhengyi; Zu, Guoqing; Du, Wei; Zhang, Xin; Jiang, Laizhu
2016-05-01
The flow behaviour of a ferritic stainless steel (FSS) was investigated by a Gleeble 3500 thermal-mechanical test simulator over the temperature range of 900-1100 °C and strain rate range of 1-50 s-1. Empirical and phenomenological constitutive models were established, and a comparative study was made on the predictability of them. The results indicate that the flow stress decreases with increasing the temperature and decreasing the strain rate. High strain rate may cause a drop in flow stress after a peak value due to the adiabatic heating. The Zener-Hollomon parameter depends linearly on the flow stress, and decreases with raising the temperature and reducing the strain rate. Significant deviations occur in the prediction of flow stress by the Johnson-Cook (JC) model, indicating that the JC model cannot accurately track the flow behaviour of the FSS during hot deformation. Both the multiple-linear and the Arrhenius-type models can track the flow behaviour very well under the whole hot working conditions, and have much higher accuracy in predicting the flow behaviour than that of the JC model. The multiple-linear model is recommended in the current work due to its simpler structure and less time needed for solving the equations relative to the Arrhenius-type model.
Lichtman, Judith H; Jones, Sara B; Leifheit-Limson, Erica C; Wang, Yun; Goldstein, Larry B
2011-12-01
Ischemic stroke patients treated at Joint Commission Primary Stroke Center (JC-PSC)-certified hospitals have better outcomes. Data reflecting the impact of JC-PSC status on outcomes after hemorrhagic stroke are limited. We determined whether 30-day mortality and readmission rates after hemorrhagic stroke differed for patients treated at JC-PSC-certified versus noncertified hospitals. The study included all fee-for-service Medicare beneficiaries aged 65 years or older with a primary discharge diagnosis of subarachnoid hemorrhage (SAH) or intracerebral hemorrhage (ICH) in 2006. Covariate-adjusted logistic and Cox proportional hazards regression assessed the effect of care at a JC-PSC-certified hospital on 30-day mortality and readmission. There were 2305 SAH and 8708 ICH discharges from JC-PSC-certified hospitals and 3892 SAH and 22 564 ICH discharges from noncertified hospitals. Unadjusted in-hospital mortality (SAH: 27.5% versus 33.2%, P<0.0001; ICH: 27.9% versus 29.6%, P=0.003) and 30-day mortality (SAH: 35.1% versus 44.0%, P<0.0001; ICH: 39.8% versus 42.4%, P<0.0001) were lower in JC-PSC hospitals, but 30-day readmission rates were similar (SAH: 17.0% versus 17.0%, P=0.97; ICH: 16.0% versus 15.5%, P=0.29). Risk-adjusted 30-day mortality was 34% lower (odds ratio, 0.66; 95% confidence interval, 0.58-0.76) after SAH and 14% lower (odds ratio, 0.86; 95% confidence interval, 0.80-0.92) after ICH for patients discharged from JC-PSC-certified hospitals. There was no difference in 30-day risk-adjusted readmission rates for SAH or ICH based on JC-PSC status. Patients treated at JC-PSC-certified hospitals had lower risk-adjusted mortality rates for both SAH and ICH but similar 30-day readmission rates as compared with noncertified hospitals.
Lichtman, Judith H.; Jones, Sara B.; Leifheit-Limson, Erica C.; Wang, Yun; Goldstein, Larry B.
2012-01-01
Background and Purpose Ischemic stroke patients treated at Joint Commission Primary Stroke Center (JC-PSC) certified hospitals have better outcomes. Data reflecting the impact of JC-PSC status on outcomes after hemorrhagic stroke are limited. We determined whether 30-day mortality and readmission rates after hemorrhagic stroke differed for patients treated at JC-PSC certified versus non-certified hospitals. Methods The study included all fee-for-service Medicare beneficiaries ≥65 years old with a primary discharge diagnosis of subarachnoid hemorrhage (SAH) or intracerebral hemorrhage (ICH) in 2006. Covariate-adjusted logistic and Cox proportional hazards regression assessed the effect of care at a JC-PSC certified hospital on 30-day mortality and readmission. Results There were 2,305 SAH and 8,708 ICH discharges from JC-PSC certified hospitals and 3,892 SAH and 22,564 ICH discharges from non-certified hospitals. Unadjusted in-hospital mortality (SAH: 27.5% vs. 33.2%, p<0.0001; ICH: 27.9% vs. 29.6%, p=0.003) and 30-day mortality (SAH: 35.1% vs. 44.0%, p<0.0001; ICH: 39.8% vs. 42.4%, p<0.0001) were lower in JC-PSC hospitals, but 30-day readmission rates were similar (SAH: 17.0% vs. 17.0%, p=0.97; ICH: 16.0% vs. 15.5%; p=0.29). Risk-adjusted 30-day mortality was 34% lower (OR 0.66, 95% CI 0.58–0.76) after SAH and 14% lower (OR 0.86, 95% CI 0.80–0.92) after ICH for patients discharged from JC-PSC certified hospitals. There was no difference in 30-day risk-adjusted readmission rates for SAH or ICH based on JC-PSC status. Conclusions Patients treated at JC-PSC certified hospitals had lower risk-adjusted mortality rates for both SAH and ICH but similar 30-day readmission rates as compared with non-certified hospitals. PMID:22033986
Gillard, Laura; Billiauws, Lore; Stan-Iuga, Bogdan; Ribeiro-Parenti, Lara; Jarry, Anne-Charlotte; Cavin, Jean-Baptiste; Cluzeaud, Françoise; Mayeur, Camille; Thomas, Muriel; Freund, Jean-Noël; Lacorte, Jean-Marc; Le Gall, Maude; Bado, André; Joly, Francisca; Le Beyec, Johanne
2016-01-01
Short bowel syndrome (SBS) patients developing hyperphagia have a better outcome. Gastrointestinal endocrine adaptations help to improve intestinal functions and food behaviour. We investigated neuroendocrine adaptations in SBS patients and rat models with jejuno-ileal (IR-JI) or jejuno-colonic (IR-JC) anastomosis with and without parenteral nutrition. Circulating levels of ghrelin, PYY, GLP-1, and GLP-2 were determined in SBS rat models and patients. Levels of mRNA for proglucagon, PYY and for hypothalamic neuropeptides were quantified by qRT-PCR in SBS rat models. Histology and immunostaining for Ki67, GLP-1 and PYY were performed in SBS rats. IR-JC rats, but not IR-JI, exhibited significantly higher crypt depths and number of Ki67-positive cells than sham. Fasting and/or postprandial plasma ghrelin and PYY concentrations were higher, or tend to be higher, in IR-JC rats and SBS-JC patients than in controls. Proglucagon and Pyy mRNA levels were significantly enhanced in IR-JC rats. Levels of mRNA coding hypothalamic orexigenic NPY and AgRP peptides were significantly higher in IR-JC than in sham rats. We demonstrate an increase of plasma ghrelin concentrations, major changes in hypothalamic neuropeptides levels and greater induction of PYY in SBS-JC rats and patients suggesting that jejuno-colonic continuity creates a peculiar environment promoting further gut-brain adaptations. PMID:27323884
Mudalkar, Shalini; Sreeharsha, Rachapudi Venkata; Reddy, Attipalli Ramachandra
2016-05-20
Abiotic stress leads to the generation of reactive oxygen species (ROS) which further results in the production of reactive carbonyls (RCs) including methylglyoxal (MG). MG, an α, β-dicarbonyl aldehyde, is highly toxic to plants and the mechanism behind its detoxification is not well understood. Aldo-keto reductases (AKRs) play a role in detoxification of reactive aldehydes and ketones. In the present study, we cloned and characterised a putative AKR from Jatropha curcas (JcAKR). Phylogenetically, it forms a small clade with AKRs of Glycine max and Rauwolfia serpentina. JcAKR was heterologously expressed in Escherichia coli BL-21(DE3) cells and the identity of the purified protein was confirmed through MALDI-TOF analysis. The recombinant protein had high enzyme activity and catalytic efficiency in assays containing MG as the substrate. Protein modelling and docking studies revealed MG was efficiently bound to JcAKR. Under progressive drought and salinity stress, the enzyme and transcript levels of JcAKR were higher in leaves compared to roots. Further, the bacterial and yeast cells expressing JcAKR showed more tolerance towards PEG (5%), NaCl (200mM) and MG (5mM) treatments compared to controls. In conclusion, our results project JcAKR as a possible and potential target in crop improvement for abiotic stress tolerance. Copyright © 2016 Elsevier GmbH. All rights reserved.
Gillard, Laura; Billiauws, Lore; Stan-Iuga, Bogdan; Ribeiro-Parenti, Lara; Jarry, Anne-Charlotte; Cavin, Jean-Baptiste; Cluzeaud, Françoise; Mayeur, Camille; Thomas, Muriel; Freund, Jean-Noël; Lacorte, Jean-Marc; Le Gall, Maude; Bado, André; Joly, Francisca; Le Beyec, Johanne
2016-06-21
Short bowel syndrome (SBS) patients developing hyperphagia have a better outcome. Gastrointestinal endocrine adaptations help to improve intestinal functions and food behaviour. We investigated neuroendocrine adaptations in SBS patients and rat models with jejuno-ileal (IR-JI) or jejuno-colonic (IR-JC) anastomosis with and without parenteral nutrition. Circulating levels of ghrelin, PYY, GLP-1, and GLP-2 were determined in SBS rat models and patients. Levels of mRNA for proglucagon, PYY and for hypothalamic neuropeptides were quantified by qRT-PCR in SBS rat models. Histology and immunostaining for Ki67, GLP-1 and PYY were performed in SBS rats. IR-JC rats, but not IR-JI, exhibited significantly higher crypt depths and number of Ki67-positive cells than sham. Fasting and/or postprandial plasma ghrelin and PYY concentrations were higher, or tend to be higher, in IR-JC rats and SBS-JC patients than in controls. Proglucagon and Pyy mRNA levels were significantly enhanced in IR-JC rats. Levels of mRNA coding hypothalamic orexigenic NPY and AgRP peptides were significantly higher in IR-JC than in sham rats. We demonstrate an increase of plasma ghrelin concentrations, major changes in hypothalamic neuropeptides levels and greater induction of PYY in SBS-JC rats and patients suggesting that jejuno-colonic continuity creates a peculiar environment promoting further gut-brain adaptations.
NASA Astrophysics Data System (ADS)
Mofizur Rahman Jahangir, Mohammad; Johnston, Paul; Khalil, Mohammad Ibrahim; Richards, Karl
2010-05-01
Denitrification may be regarded as the dominant nitrate removal or attenuation process in shallow groundwater. A major concern arising from the denitrification process is that it not only serves as a natural pathway for excess NO3- removal but its intermediate product, N2O, is a potent greenhouse gas. A groundwater monitoring network was established on grazed grassland at research farms at Johnstown Castle (JC) and Solohead (SH) on tillage at Oak Park (OP) in Ireland, to investigate the denitrification capacity and N2O:(N2O+N2) ratio within the shallow groundwater zone. The geology of this zone at the 3 sites was i) JC: sand and gravel intermixed with clay, ii) SH: silt and gravel intermixed with dense clay and iii) OP: dense gravel with interbedded clays. Average groundwater table was respectively 3.2, 2.4 and 4.0 m below ground level. Ten piezometers of 50 mm ID with 2 m screen sections were installed at 3.5-6.0 m below ground level using a rotary air drilling method at the three sites. Groundwater sampling was carried out monthly for 6 months (February to July, 2009) using a bladder pump following the USEPA low flow sampling procedures. Dissolved groundwater N2O was separated by degassing groundwater in a sealed serum bottle (160ml) using high purity He (water:He = 3:1) and the collected headspace equilibrium gas was analyzed on a Varian gas chromatograph. The N2/Ar ratio, measured using a Membrane Inlet Mass Spectrometer, was used to estimate the denitrified N2 concentrations. The mean NO3-N concentrations were 7.0, 2.5 and 11.0 mg L-1 in JC, SH and OP, respectively. Ground water dissolved N2O concentrations ranged from 0.01 to 0.05, 0.01 to 0.06 and 0.002 to 0.06 mg L-1, with corresponding mean values of 0.03, 0.02, 0.02 mg N.L-1 in JC, SH and OP, respectively. The mean values for total denitrification (N2O+N2) were 1.94, 1.03 and 0.38 mg N.L-1, which accounted for 22, 29 and 3% losses of total NO3- -N in JC, SH and OP, respectively. The higher denitrification measured on the grassland compared to tillage is most likely related to the hydrogeological conditions e.g. DOC, DO and redox-potential rather than land-use. More importantly, the mean N2O:N2O+N2 ratios, being 0.01, 0.02 and 0.05, respectively in JC, SH and OP indicated that 95-99% of total denitrification was molecular N2 (98-99% in grassland and 95% in tillage farm). With respect to temporal changes, denitrification losses were higher in May in grassland systems and in April in tillage farming systems. Shallow groundwater denitrification appeared to be an important process in reducing NO3- , with low N2O concentrations indicating low losses of this greenhouse gas to the atmosphere upon discharging to surface water.
Watts, D M; LeDuc, J W; Bailey, C L; Dalrymple, J M; Gargan, T P
1982-11-01
Serological data accumulated during the past decade indicated that a variety of feral and domestic animals of the Delaware-Maryland-Virginia (DelMarVa) Peninsula were infected with Jamestown Canyon (JC) and/or Keystone (KEY) viruses (Bunyaviridae, California serogroup). Neutralizing (N) antibody to JC virus was most prevalent in white-tailed deer, sika deer, cottontail rabbits and horses. KEY virus N antibody was detected most frequently in gray squirrels and domestic goats. N antibody indicative of past infection by one or both viruses also was found in raccoons, horses and humans. JC and/or KEY virus N antibodies were not demonstrable in sera of several other species of small mammals and reptiles. Investigations were extended to evaluate the role of domestic goats as an amplifying host of JC and KEY viruses and to assess their potential as sentinels of virus transmission. Goats maintained in the Pocomoke Cypress Swamp during the summer season of 1978, acquired N antibodies to JC and KEY viruses. Following experimental inoculation with either JC or KEY virus, all goats developed N antibody despite the absence of a demonstrable viremia in most animals. Goats proved to be effective as sentinels for monitoring the transmission of JC and KEY viruses; however, the exceptionally low titers or absence of viremia following inoculation with these viruses would seem to preclude a potential virus-amplifying role for this species. Although findings implicated primarily gray squirrels and white-tailed deer as possible amplifying hosts of KEY and JC virus, respectively, further investigations will be required to clarify their role, particularly since both viruses may be maintained entirely by transovarial transmission.
van Haaften, Caroline; Boot, Arnoud; Corver, Willem E; van Eendenburg, Jaap D H; Trimbos, Baptist J M Z; van Wezel, Tom
2015-04-25
Ovarian cancer remains still the leading cause of death of gynecological malignancy, in spite of first-line chemotherapy with cisplatin and paclitaxel. Although initial response is favorably, relapses are common and prognosis for women with advanced disease stays poor. Therefore efficacious approaches are needed. Previously, an anti-cancer agent, EPD exhibited potent cytotoxic effects towards ovarian cancer and not towards normal cells. Cell viability and cell cycle analysis studies were performed with EPD, in combination with cisplatin and/or paclitaxel, using the ovarian carcinoma cell lines: SK-OV-3, OVCAR-3, JC, JC-pl and normal fibroblasts. Cell viability was measured using Presto Blue and cell cycle analysis using a flow cytometer. Apoptosis was measured in JC and JC-pl , using the caspase 3 assay kit. In JC-pl, SK-OV-3 and JC, synergistic interactions between either EPD and cisplatin or EPD and paclitaxel were observed. For the first time the effects of EPD on the cell cycle of ovarian cancer cells and normal cells was studied. EPD and combinations of EPD with cisplatin and/ or paclitaxel showed cell cycle arrest in the G2/M phase. The combination of EPD and cisplatin showed a significant synergistic effect in cell line JC-pl, while EPD with paclitaxel showed synergistic interaction in JC. Additionally, synergistic drug combinations showed increased apoptosis. Our results showed a synergistic effect of EPD and cisplatin in an ovarian drug resistant cell line as well as a synergistic effect of EPD and paclitaxel in two other ovarian cell lines. These results might enhance clinical efficacy, compared to the existing regimen of paclitaxel and cisplatin.
Roseomonas oryzae sp. nov., isolated from paddy rhizosphere soil.
Ramaprasad, E V V; Sasikala, Ch; Ramana, Ch V
2015-10-01
A non-motile, coccus-shaped, pale-pink-pigmented bacterium, designated strain JC288T, was isolated from a paddy rhizosphere soil collected from Western Ghats, Kankumbi, Karnataka, India. Cells were found to be Gram-stain-negative, and catalase- and oxidase-positive; the major fatty acids were C16 : 0, C16 : 1ω7c/C16 : 1ω6c, C18 : 1ω7c/C18 : 1ω6c and C18 : 1 2-OH. The predominant respiratory quinone was Q-10 and the genomic DNA G+C content was 67.5 mol%. Strain JC288T contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, four unidentified aminolipids, three unidentified phospholipids, two unidentified lipids, an aminophospholipid and a glycolipid. Hydroxyspirilloxanthin was the major carotenoid of strain JC288T. 16S rRNA gene sequence comparisons indicated that strain JC288T represents a member of the genus Roseomonas within the family Acetobacteraceae of the phylum Proteobacteria. Strain JC288T shared the highest 16S rRNA gene sequence similarity with Roseomonas rhizosphaerae YW11T (97.3 %), Roseomonas aestuarii JC17T (97.1 %), Roseomonas cervicalis CIP 104027T (95.9 %) and other members of the genus Roseomonas ( < 95.5 %). The distinct genomic difference and morphological, physiological and chemotaxonomic differences from the previously described taxa support the classification of strain JC288T as a representative of a novel species of the genus Roseomonas, for which the name Roseomonas oryzae sp. nov. is proposed. The type strain is JC288T ( = KCTC 42542T = LMG 28711T).
Plasma and Electro-energetic Physics
2012-03-07
Dynamical Equations (with complex surfaces ): Relativistic Lorentz Force Law for relativistic momentum p and velocity u: tDcJcH tBcE /)/1()/4...0.1-1 s • 3D, high-fidelity, parallel modeling of high energy density fields and particles in complex geometry with some surface effects...cathodes (500 µm separation) Tang, AFRL/RD 12 DISTRIBUTION A: Approved for public release; distribution is unlimited. ICEPIC simulations Equipotential
Processing of Mixed Oxide Superconductors
1989-01-01
doping with cobalt to eliminate twins we were able to show that the effect of twins on Jc is generall- very small (later work by * others has shown a...to show that the forces available by Meissner effects are far too small to be useful and it is necessary to work in higher fields, using the forces...I when working out the effective volume fraction at high 0 densities that even if the grains are touching there is an This is the same as the
Temperature Versus Salinity Gradients Below the Ocean Mixed Layer
2012-05-03
where salinity controls the depth of the mixed layer are understood to have “barrier” layers [Lukas and Lindstrom , 1991], where the depth of vertically...the horizontal. For example, Rudnick and Martin [2002] have shown that the ocean mixed layer at sub-mesoscales is horizontally well density compensated...Res., 102, 23,063–23,078, doi:10.1029/97JC01443. Barron, C. N., A. B. Kara, P. J. Martin , R. C. Rhodes, and L. F. Smedstad (2006), Formulation
Submillimeter SIS Mixers Using High Current Density Nb/AIN/Nb Tunnel Junctions and NbTiN Films
NASA Astrophysics Data System (ADS)
Kawamura, J.; Miller, D.; Chen, J.; Kooi, J.; Zmuidzinas, J.; Bumble, B.; Leduc, H.; Stern, J.
1999-03-01
We are currently exploring ways to improve the performance of SIS mixers above 700 GHz. One approach is to use NbTiN in place of Nb for all or some of the mixer circuitry. With its high gap frequency and low losses demonstrated up to 800 GHz, it should be possible to fabricate an all-NbTiN SIS mixer with near quantum-limited noise performance up to 1.2 THz. Using a quasioptical twin-slot two-junction mixer with NbTiN ground plane and wiring and hybrid Nb/A1N/NbTiN junctions, we measured an uncorrected receiver noise temperature of TRx ~ 500 K across 790-850 GHz at 4.2 K bath temperature. Our second approach is to reduce the RC product of the mixer by employing very high current density Nb/A1N/Nb junctions. By using these we will greatly relax the requirement on tuning circuits, which is where substantial losses occur in mixers operating above the Nb gap frequency. These junctions have resistance-area products of R_N*A ~ 5.6 Ohm um2, good subgap to normal resistance ratios, R_sg/R_N ~ 10, and good run-to-run reproducibility. From FTS measurements we infer that omega*R_N*C = 1 at 270 GHz in these junctions. This is a substantial improvement over that available using Nb/Al0x/Nb technology. The sensitivity of a receiver incorporating these high current density mixers is T_Rx = 110 K at 533 GHz using a design for lower J_c mixers, which is close to the best we have measured with lower J_c Nb/Al0x/Nb mixers.
NASA Astrophysics Data System (ADS)
Moffitt, Sarah E.; Hill, Tessa M.; Ohkushi, Kenichi; Kennett, James P.; Behl, Richard J.
2014-01-01
we present a history of deoxygenation of upper intermediate waters during the last deglaciation from Santa Barbara Basin (SBB), based on quantitative analyses of benthic foraminiferal assemblages, from a new shallow piston core above basin sill depth (MV0811-15JC, 418 m), and previously described sequences in the deeper basin (MD02-2504, 481 m and MD02-2503, 570 m). We document a 152 m depth transect of benthic foraminiferal assemblages to extract changing community structure (density, diversity, and evenness) and improve paleoenvironmental interpretation of late Quaternary vertical oscillations in the upper boundary of the oxygen minimum zone (OMZ). Close interaction between changes in open margin OMZ and that of the restricted SBB is documented using these quantitative techniques. MV0811-15JC, while being unlaminated, contains strongly hypoxic foraminiferal assemblages (including species Bolivina tumida and Nonionella stella), coeval with preserved sediment laminations in the deeper cores. Last Glacial Maximum (LGM) assemblages across this transect contained oxic fauna and high diversity. At 14.7 ka, glacial termination IA, hypoxic benthic fauna appeared across the transect, recording hypoxic waters (<0.5 ml L-1) < 300 m from the ocean surface. Bølling/Allerød (B/A) assemblages uniquely stand out in the record, exhibited by low density, diversity, and evenness, and taxonomic composition reflecting extreme and stressful hypoxia and methane-rich environments. Younger Dryas assemblages were diverse and composed of oxic fauna, similar to LGM assemblages. Termination IB initiated another deoxygenation shift, followed by OMZ-associated faunal and density patterns. This analysis strengthens the quantitative assessment of oxygen concentrations involved in deglacial OMZ change and reveals the unexpected, remarkable shallowness of OMZ influence during the B/A.
An Economic History of Indian Treaties in the Great Lakes Region
ERIC Educational Resources Information Center
American Indian Journal, 1978
1978-01-01
An attempt to do what has rarely been done in the 19th century, this article examines the actual economic resources and values associated with United States Indian treaties and agreements in the Great Lakes region (land, trade, timber, maple sugar, fish and game, water resources, military posts and roads, and annuities). (JC)
Universal current-velocity relation of skyrmion motion in chiral magnets
NASA Astrophysics Data System (ADS)
Iwasaki, Junichi; Mochizuki, Masahito; Nagaosa, Naoto
2013-03-01
Current-driven motion of the magnetic domain wall requires large critical current density jc ~109 -1012 A/m2, at which the joule heating is a serious problem. The skyrmions recently discovered in chiral magnets, on the other hand, have much smaller critical current of jc ~105 -106 A/m2. We present a numerical simulation of the Landau-Lifshitz-Gilbert equation, which reveals a remarkably robust and universal current-velocity relation of the slyrmion motion driven by the spin transfer torque unaffected by either impurities or nonadiabatic effect in sharp contrast to the case of domain wall or spin helix (HL). Simulation results are analyzed using a theory based on Thiele's equation, and it is concluded that this surprising behavior is due to the Magnus force and flexible shape-deformation of individual skyrmions and skyrmion crystal (SkX), which enable them to avoid pinning centers and then weaken the net pinning force. Dynamical deformation of SkX leads to the fluctuation of Bragg peak with large amplitude, which can be detected by the recent neutron-scattering experiment.
Prise en compte des ``courants de London'' dans la modélisation des supraconducteurs
NASA Astrophysics Data System (ADS)
Bossavit, Alain
1997-10-01
A model is given, in variational form, in which volumic “Bean currents”, ruled by Bean's law, and surface “London currents” coexist. This macroscopic model generalizes Bean's one, by appending to the critical density j_c a second parameter, with the dimension of a length, similar to London's depth λ. The one-dimensional version of the model is investigated, in order to link this parameter with the standard observable H-M characteristics On propose un modèle, sous forme variationnelle, associant des “courants de Bean” volumiques, décrits par la loi de Bean, et des “courants de London”, surfaciques. Ce modèle macroscopique généralise celui de Bean, caractérisé par le courant critique j_c, et fait intervenir un second paramètre, homogène à une longueur, analogue au λ de London. La version unidimensionnelle du modèle est étudiée en détail de manière à relier ce paramètre à l'observation des caractéristiques H-M usuelles.
NASA Astrophysics Data System (ADS)
Takeuchi, T.; Tsuchiya, K.; Saeda, M.; Banno, N.; Kikuchi, A.; Iijima, Y.
2010-12-01
To enhance the non-Cu critical current density Jc at 15 T and 4.2 K (1000 A mm - 2 at present) we have endeavoured to refine the grain size of rapid heating, quenching and transformation (RHQT)-processed Nb3Al. In the present study, the grain boundary structures of RHQT-processed Nb3Al were examined by electron backscatter diffraction (EBSD) because transgranular fracture prevents the observation of fractured cross sections of Nb3Al to statistically determine the grain size. The grain size distributions of body-centred-cubic supersaturated-solid-solution Nb(Al)ss and A15 Nb3Al filaments were measured for grains misoriented by more than 2°, 5° and 15°. A mixed grain structure, which consists of a few large grains (>25 µm) and many small grains (<1 µm), was observed for an Nb3Al filament that had been transformed from non-deformed Nb(Al)ss. Plastic deformation that had been made between the rapid heating and quenching steps and the transformation step apparently homogenized the grain size distribution and then reduced the average grain size. The misorientation angle distributions of Nb(Al)ss and Nb3Al were also measured and compared with each other. A clear relationship between the Jc and the inverse grain size was not confirmed for the RHQT Nb3Al conductors examined in the present study, which indicates the importance of making a filament compositionally homogeneous to obtain a high Jc.
Effect of the seed layer on the Y0.5Gd0.5Ba2Cu3O7-σ film fabricated by PLD
NASA Astrophysics Data System (ADS)
Yao, Yanjie; Wang, Wei; Liu, Linfei; Lu, Saidan; Wu, Xiang; Zheng, Tong; Liu, Shunfan; Li, Yijie
2018-06-01
The surface morphology and internal residual stress have influence on the critical current density (Jc) of REBa2Cu3O7-σ (REBCO) coated conductor. In order to modulate them, a series of Y0.5Gd0.5Ba2Cu3O7-σ (YGBCO) films were prepared by pulsed laser deposition (PLD) through introducing a seed layer in this paper. The thicknesses of seed layer changes from about 2 nm to 30 nm. For comparison, a standard sample without seed layer was fabricated at the same deposition condition. The surface morphology was illustrated by Scanning electron microscopy (SEM). The surface roughness was scanned by Atomic force microscopy (AFM). The microstructure and internal strain were measured by X-ray Diffraction (XRD). DC four-probe method was used to measure the critical current of the samples at 77 K and self-field. As a result, all samples have high Jc of about 4 MA/cm2, while the self-field Jc of the YGBCO films can be promoted by the seed layer. The results of our research work are as follows. First of all, seed layer makes the deposition of the YGBCO layer much easier to control. By this way, we can decrease the surface roughness of the samples. Furthermore, the internal residual stress of the YGBCO films with seed layer decrease. Finally, the best thickness of the seed layer was found by summarizing and analyzing the conditions of seed layer.
Francesconi, Walter; Berton, Fulvia; Koob, George F.; Sanna, Pietro Paolo
2010-01-01
The juxtacapsular nucleus of the anterior division of the BNST (jcBNST) receives robust glutamatergic projections from the basolateral nucleus of the amygdala (BLA), the postpiriform transition area, and the insular cortex as well as dopamine (DA) inputs from the midbrain. In turn the jcBNST sends GABAergic projections to the medial division of the central nucleus of the amygdala (CEAm) as well as other brain regions. We recently described a form of long-term potentiation of the intrinsic excitability (LTP-IE) of neurons of the juxtacapsular nucleus of BNST (jcBNST) in response to high-frequency stimulation (HFS) of the stria terminalis that was impaired during protracted withdrawal from alcohol, cocaine, and heroin and in rats chronically treated with corticotropin releasing factor (CRF) intracerebroventricularly. Here we show that DAergic neurotransmission is required for the induction of LTP-IE of jcBNTS neurons through dopamine (DA) D1 receptors. Thus, activation of the central CRF stress system and altered DAergic neurotransmission during protracted withdrawal from alcohol and drugs of abuse may contribute to the disruption of LTP-IE in the jcBNST. Impairment of this form of intrinsic neuronal plasticity in the jcBNST could result in inadequate neuronal integration and reduced inhibition of the CEA, contributing to the negative affective state that characterizes protracted abstinence in post-dependent individuals. These results provide a novel neurobiological target for vulnerability to alcohol and drug dependence. PMID:19683025
Tang, Yuehui; Qin, Shanshan; Guo, Yali; Chen, Yanbo; Wu, Pingzhi; Chen, Yaping; Li, Meiru; Jiang, Huawu; Wu, Guojiang
2016-01-01
The AP2/ERF transcription factors play crucial roles in plant growth, development and responses to biotic and abiotic stresses. A total of 119 AP2/ERF genes (JcAP2/ERFs) have been identified in the physic nut genome; they include 16 AP2, 4 RAV, 1 Soloist, and 98 ERF genes. Phylogenetic analysis indicated that physic nut AP2 genes could be divided into 3 subgroups, while ERF genes could be classed into 11 groups or 43 subgroups. The AP2/ERF genes are non-randomly distributed across the 11 linkage groups of the physic nut genome and retain many duplicates which arose from ancient duplication events. The expression patterns of several JcAP2/ERF duplicates in the physic nut showed differences among four tissues (root, stem, leaf, and seed), and 38 JcAP2/ERF genes responded to at least one abiotic stressor (drought, salinity, phosphate starvation, and nitrogen starvation) in leaves and/or roots according to analysis of digital gene expression tag data. The expression of JcERF011 was downregulated by salinity stress in physic nut roots. Overexpression of the JcERF011 gene in rice plants increased its sensitivity to salinity stress. The increased expression levels of several salt tolerance-related genes were impaired in the JcERF011-overexpressing plants under salinity stress. PMID:26943337
Honda, Kohei; Saito, Hidekazu; Fukui, Naoko; Ito, Eiko; Ishikawa, Kazuo
2013-09-01
The prevalence of Japanese cedar (JC) pollinosis in Japanese children is increasing. However, few studies have reported the relationship between pollen count levels and the prevalence of pollinosis. To evaluate the relationship between JC pollen count levels and the prevalence of pollinosis in children, we investigated the sensitization and development of symptoms for JC pollen in two areas of Akita in northeast Japan with contrasting levels of exposure to JC pollen. The study population consisted of 339 elementary school students (10-11 years of age) from the coastal and mountainous areas of Akita in 2005-2006. A questionnaire about symptoms of allergic rhinitis was filled out by the students' parents. A blood sample was taken to determine specific IgE antibodies against five common aeroallergens. The mean pollen count in the mountainous areas was two times higher than that in the coastal areas in 1996-2006. The prevalence rates of nasal allergy symptoms and sensitization for mites were almost the same in both areas. On the other hand, the rates of nasal allergy symptoms and sensitization for JC pollen were significantly higher in the mountainous areas than in the coastal areas. The rate of the development of symptoms among children sensitized for JC pollen was almost the same in both areas. These results suggest that pollen count levels may correlate with the rate of sensitization for JC pollinosis, but may not affect the rate of onset among sensitized children in northeast Japan.
Tang, Yuehui; Qin, Shanshan; Guo, Yali; Chen, Yanbo; Wu, Pingzhi; Chen, Yaping; Li, Meiru; Jiang, Huawu; Wu, Guojiang
2016-01-01
The AP2/ERF transcription factors play crucial roles in plant growth, development and responses to biotic and abiotic stresses. A total of 119 AP2/ERF genes (JcAP2/ERFs) have been identified in the physic nut genome; they include 16 AP2, 4 RAV, 1 Soloist, and 98 ERF genes. Phylogenetic analysis indicated that physic nut AP2 genes could be divided into 3 subgroups, while ERF genes could be classed into 11 groups or 43 subgroups. The AP2/ERF genes are non-randomly distributed across the 11 linkage groups of the physic nut genome and retain many duplicates which arose from ancient duplication events. The expression patterns of several JcAP2/ERF duplicates in the physic nut showed differences among four tissues (root, stem, leaf, and seed), and 38 JcAP2/ERF genes responded to at least one abiotic stressor (drought, salinity, phosphate starvation, and nitrogen starvation) in leaves and/or roots according to analysis of digital gene expression tag data. The expression of JcERF011 was downregulated by salinity stress in physic nut roots. Overexpression of the JcERF011 gene in rice plants increased its sensitivity to salinity stress. The increased expression levels of several salt tolerance-related genes were impaired in the JcERF011-overexpressing plants under salinity stress.
NASA Astrophysics Data System (ADS)
Duc-Toan, Nguyen; Tien-Long, Banh; Young-Suk, Kim; Dong-Won, Jung
2011-08-01
In this study, a modified Johnson-Cook (J-C) model and an innovated method to determine (J-C) material parameters are proposed to predict more correctly stress-strain curve for tensile tests in elevated temperatures. A MATLAB tool is used to determine material parameters by fitting a curve to follow Ludwick's hardening law at various elevated temperatures. Those hardening law parameters are then utilized to determine modified (J-C) model material parameters. The modified (J-C) model shows the better prediction compared to the conventional one. As the first verification, an FEM tensile test simulation based on the isotropic hardening model for boron sheet steel at elevated temperatures was carried out via a user-material subroutine, using an explicit finite element code, and compared with the measurements. The temperature decrease of all elements due to the air cooling process was then calculated when considering the modified (J-C) model and coded to VUMAT subroutine for tensile test simulation of cooling process. The modified (J-C) model showed the good agreement between the simulation results and the corresponding experiments. The second investigation was applied for V-bending spring-back prediction of magnesium alloy sheets at elevated temperatures. Here, the combination of proposed J-C model with modified hardening law considering the unusual plastic behaviour for magnesium alloy sheet was adopted for FEM simulation of V-bending spring-back prediction and shown the good comparability with corresponding experiments.
Composite ceramic superconducting wires for electric motor applications
NASA Astrophysics Data System (ADS)
Holloran, John W.
1989-07-01
Progress is described on developing Y-123 wire for an HTSC motor. The wire development involves synthesis of Y-123 powder, spinning polymer containing green fiber, heat treating the fiber to produce metallized superconducting filaments, and characterizing the electrical properties. A melt spinning process was developed for producing 125-micron diameter green fiber containing 50 vol percent Y-123. This fiber can be braided for producing transposed multifilamentary wire. A process was developed to coat green fiber with silver alloys which can be continuous sintering. A second process for multifilamentary ribbon wire is also being developed. The Y-123 filaments have 77 deg self-field Jc values up to 2600 A/sq cm, but Jc is reduced to 10 A/cm squared at 800 G. Preliminary data is presented on mechanical properties. A dc homopolar motor with an iron magnetic circuit is being designed to operate with early HTSC wire.
Improved Pinning Morphology in HTS with Order of Magnitude Increase in Jc and Pinned Field
2008-01-27
Patricia Nieto 0.25 Lilliana Phamnguyen 0.25 William Rifenburgh 0.25 Adriana Rodriguez 0.25 Jonathan Salazar 0.25 Michael Saldana 0.25 Clinton Seibert...times higher than the initial Jc. Bulk YBCO was used in the experiment, and Jc set a new world’s record of 321 kA /cc for this variety of HTS, over 5
J.C. Nalle Community School: A Study of a School Turnaround Effort. Publication #2015-14
ERIC Educational Resources Information Center
Redd, Zakia; Princiotta, Daniel; Stratford, Brandon; Caal, Selma; Li, Weilin; Murphy, Kelly; Coffey, Amelia; Carrington, Nicholas; Carney, Rachel; Oster, Maryjo; Horton, Susannah
2015-01-01
J.C. Nalle is a Community School located in the Marshall Heights neighborhood of Ward 7 in Washington, D.C. The community in which J.C. Nalle is located, historically one of the more economically disadvantaged areas of the city, has experienced a number of changes in recent years. This report of evaluation findings begins with an introduction to…
NASA Astrophysics Data System (ADS)
Pavan Kumar Naik, S.; Bai, V. Seshu
2017-02-01
In the present work, with the aim of improving the local flux pinning at the unit cell level in the YBa2Cu3O7-δ (YBCO) bulk superconductors, 20 wt% of nanoscale Sm2O3 and micron sized (Nd, Sm, Gd)2BaCuO5 secondary phase particles were added to YBCO and processed in oxygen controlled preform optimized infiltration growth process. Nano Dispersive Sol Casting method is employed to homogeneously distribute the nano Sm2O3 particles of 30-50 nm without any agglomeration in the precursor powder. Microstructural investigations on doped samples show the chemical fluctuations as annuli cores in the 211 phase particles. The introduction of mixed rare earth elements at Y-site resulted in compositional fluctuations in the superconducting matrix. The associated lattice mismatch defects have provided flux pinning up to large magnetic fields. Magnetic field dependence of current density (Jc(H)) at different temperatures revealed that the dominant pinning mechanism is caused by spatial variations of critical temperatures, due to the spatial fluctuations in the matrix composition. As the number of rare earth elements increased in the YBCO, the peak field position in the scaling of the normalized pinning force density (Fp/Fp max) significantly gets shifted towards the higher fields. The curves of Jc(H) and Fp/Fp max at different temperatures clearly indicate the LRE substitution for LRE' or Ba-sites for δTc pinning.
Massee, Freek; Sprau, Peter Oliver; Wang, Yong-Lei; Davis, J. C. Séamus; Ghigo, Gianluca; Gu, Genda D.; Kwok, Wai-Kwong
2015-01-01
Maximizing the sustainable supercurrent density, JC, is crucial to high-current applications of superconductivity. To achieve this, preventing dissipative motion of quantized vortices is key. Irradiation of superconductors with high-energy heavy ions can be used to create nanoscale defects that act as deep pinning potentials for vortices. This approach holds unique promise for high-current applications of iron-based superconductors because JC amplification persists to much higher radiation doses than in cuprate superconductors without significantly altering the superconducting critical temperature. However, for these compounds, virtually nothing is known about the atomic-scale interplay of the crystal damage from the high-energy ions, the superconducting order parameter, and the vortex pinning processes. We visualize the atomic-scale effects of irradiating FeSexTe1−x with 249-MeV Au ions and find two distinct effects: compact nanometer-sized regions of crystal disruption or “columnar defects,” plus a higher density of single atomic site “point” defects probably from secondary scattering. We directly show that the superconducting order is virtually annihilated within the former and suppressed by the latter. Simultaneous atomically resolved images of the columnar crystal defects, the superconductivity, and the vortex configurations then reveal how a mixed pinning landscape is created, with the strongest vortex pinning occurring at metallic core columnar defects and secondary pinning at clusters of point-like defects, followed by collective pinning at higher fields. PMID:26601180
Qiu, Wenbin; Jie, Hyunseock; Patel, Dipak; Lu, Yao; Luzin, Vladimir; Devred, Arnaud; Somer, Mehmet; Shahabuddin, Mohammed; Kim, Jung Ho; Ma, Zongqing; Dou, Shi Xue; Hossain, Md. Shahriar Al
2016-01-01
Superconducting wires are widely used in fabricating magnetic coils in fusion reactors. In consideration of the stability of 11B against neutron irradiation and lower induced radio-activation properties, MgB2 superconductor with 11B serving as boron source is an alternative candidate to be used in fusion reactor with severe irradiation environment. In present work, a batch of monofilament isotopic Mg11B2 wires with amorphous 11B powder as precursor were fabricated using powder-in-tube (PIT) process at different sintering temperature, and the evolution of their microstructure and corresponding superconducting properties was systemically investigated. Accordingly, the best transport critical current density (Jc) = 2 × 104 A/cm2 was obtained at 4.2 K and 5 T, which is even comparable to multi-filament Mg11B2 isotope wires reported in other work. Surprisingly, transport Jc vanished in our wire which was heat-treated at excessively high temperature (800 °C). Combined with microstructure observation, it was found that lots of big interconnected microcracks and voids that can isolate the MgB2 grains formed in this whole sample, resulting in significant deterioration in inter-grain connectivity. The results can be a constructive guide in fabricating Mg11B2 wires to be used as magnet coils in fusion reactor systems such as ITER-type tokamak magnet. PMID:27824144
Liaw, Yu-Ching; Chen, Cheng-Hsu; Shu, Kuo-Hsiung; Fang, Chiung-Yao; Ou, Wei-Chih; Chen, Pei-Lain; Shen, Cheng-Huang; Lin, Mien-Chun; Chang, Deching; Wang, Meilin
2012-12-01
Kidney cells are the common host for JC virus (JCV) and BK virus (BKV). Reactivation of JCV and/or BKV in patients after organ transplantation, such as renal transplantation, may cause hemorrhagic cystitis and polyomavirus-associated nephropathy. Furthermore, JCV and BKV may be shed in the urine after reactivation in the kidney. Rearranged as well as archetypal non-coding control regions (NCCRs) of JCV and BKV have been frequently identified in human samples. In this study, three JC/BK recombined NCCR sequences were identified in the urine of a patient who had undergone renal transplantation. They were designated as JC-BK hybrids 1, 2, and 3. The three JC/BK recombinant NCCRs contain up-stream JCV as well as down-stream BKV sequences. Deletions of both JCV and BKV sequences were found in these recombined NCCRs. Recombination of DNA sequences between JCV and BKV may occur during co-infection due to the relatively high homology of the two viral genomes.
JC virus chromogenic in situ hybridization in brain biopsies from patients with and without PML.
Procop, Gary W; Beck, Rose C; Pettay, James D; Kohn, Debra J; Tuohy, Marion J; Yen-Lieberman, Belinda; Prayson, Richard A; Tubbs, Raymond R
2006-06-01
Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by the JC polyoma virus. Electron microscopy and immunohistochemistry are the traditional methods of confirming the presence of the virus in brain biopsies from these patients. We studied the brain biopsies from 7 patients with PML and 6 patients without PML with chromogenic in situ hybridization (CISH) for the JC polyoma virus using a commercially available probe. The biopsies from the patients with the PML cases were proven to contain the JC polyoma virus by traditional and molecular methods. The CISH findings were compared with the known state of infection. All (7/7) of the biopsies from patients with PML were positive for the presence of polyoma virus by CISH, whereas the biopsies from patients without PML were uniformly negative. CISH seems to be a useful tool for the detection of the JC virus in brain biopsies from patients with PML, and is more accessible because a commercial probe is available.
Hua, Wan; Hu, Huiling; Chen, Fang; Tang, Lin; Peng, Tong; Wang, Zhanguo
2015-03-18
In this work, a high-speed countercurrent chromatography (HSCCC) method was established for the preparation of phorbol esters (PEs) from Jatropha curcas. n-Hexane-ethyl acetate-methanol-water (1.5:1.5:1.2:0.5, v/v) was selected as the optimum two-phase solvent system to separate and purify jatropha factor C1 (JC1) with a purity of 85.2%, as determined by HPLC, and to obtain a mixture containing four or five PEs. Subsequently, continuous semipreparative HPLC was applied to further purify JC1 (99.8% as determined by HPLC). In addition, UPLC-PDA and UPLC-MS were established and successfully used to evaluate the isolated JC1 and PE-rich crude extract. The purity of JC1 was only 87.8% by UPLC-UV. A peak (a compound highly similar to JC1) was indentified as the isomer of JC1 by comparing the characteristic UV absorption and MS spectra. Meanwhile, this strategy was also applied to analyze the PE-rich crude extract from J. curcas. It is interesting that there may be more than 15 PEs according to the same quasi-molecular ion peaks, highly similar sequence-specific fragment ions, and similar UV absorption spectrum.
Ismail, Sherine; Al Khansa, Sara; Aseeri, Mohammed; Alhamdan, Hani; Quadri, K. H. Mujtaba
2017-01-01
Journal clubs have been traditionally incorporated into academic training programs to enhance competency in the interpretation of literature. We designed a structured journal club (JC) to improve skills in the interpretation of literature; however, we were not aware of how learners (interns, residents, clinical pharmacists, etc.) would perceive it. We aimed to assess the perception of learners at different levels of pharmacy training. A cross-sectional design was used. A self-administered online survey was emailed to JC attendees from 2010–2014 at King Abdulaziz Medical City, Jeddah, Saudi Arabia. The survey questions included: introduction sessions, topic selection, JC layout, interaction with the moderator, and decision-making skills by clinical pharmacists. The response rate was 58/89 (65%); 52/54 (96%) respondents believed that JC adds to their knowledge in interpreting literature. Topic selection met the core curriculum requirements for credentials exams for 16/36 (44.4%), while 16/22 (73%) presenters had good to excellent interaction with the moderator. JC facilitated decision-making for 10/12 (83%) of clinical pharmacists. The results suggest that clinical pharmacist-steered JC may serve as an effective tool to empower learners at different levels of pharmacy practice, with evidence-based principles for interpretation of literature and guide informed decision-making. PMID:28970415
Cosmetic procedures among youths: a survey of junior college and medical students in Singapore.
Ng, Jia Hui; Yeak, Seth; Phoon, Natalie; Lo, Stephen
2014-08-01
Although cosmetic procedures have become increasingly popular among the younger population in recent years, limited research on this subject has been done in the Asian context. We aimed to explore the views and knowledge regarding cosmetic procedures among junior college (JC) and medical students in Singapore. In the first phase of the study, a cross-sectional, self-administered survey of 1,500 JC students aged 16-21 years from six JCs was conducted in 2010. The same survey was then conducted on a random sample of Year 2-5 medical students from an undergraduate medical school in 2011. In total, 1,164 JC and 241 medical students responded to the surveys. There was an overall female to male ratio of 1.3:1. Of all the respondents, 2.5% of the JC students and 3.0% of the medical students admitted to having undergone cosmetic procedures. Among those who claimed to have never had cosmetic procedures done, 9.0% and 44.0% of the JC and medical students, respectively, responded that they would consider such procedures in the future. Those who disapproved of their peers undergoing cosmetic surgery comprised 35.0% of JC students and 56.8% of medical students. Among the JC and medical students, 52.0% and 36.1%, respectively, were unaware of any risks associated with cosmetic procedures. The younger population is increasingly accepting of cosmetic procedures. However, there is a general lack of understanding of the risks associated with such procedures. Education of both the general public and medical students may help prevent potential medicolegal issues.
Hu, Ying-Xiong; Tao, Yan-Bin; Xu, Zeng-Fu
2017-01-01
Gibberellins (GAs) are plant hormones that play fundamental roles in plant growth and development. Gibberellin 2-oxidase (GA2ox) plays a direct role in determining the levels of bioactive GAs by catalyzing bioactive GAs or their immediate precursors to inactive forms. In this study, a GA2ox gene, designated JcGA2ox6, was isolated from Jatropha curcas. JcGA2ox6 is expressed in all tissues of adult Jatropha, with the highest expression level in male flowers and the lowest expression level in young leaves. Overexpression of JcGA2ox6 in Arabidopsis resulted in a typical dwarf phenotype, along with late flowering, smaller leaves and flowers, shorter siliques and smaller seeds. Similarly, when JcGA2ox6 was overexpressed in Jatropha, the transgenic plants exhibited a dwarf phenotype with dark-green leaves and smaller inflorescences, flowers, fruits and seeds. However, the flowering time of Jatropha was not affected by overexpression of JcGA2ox6, unlike that in the transgenic Arabidopsis. Moreover, the number of flowers per inflorescence, the weight of 10 seeds and the seed oil content were significantly decreased in transgenic Jatropha. The results indicated that overexpression of JcGA2ox6 had a great impact on the vegetative and reproductive growth of transgenic Jatropha. Furthermore, we found that the dwarf phenotype of transgenic Jatropha was caused by a decrease in endogenous bioactive GA4, which was correlated with the degree of dwarfism. PMID:29312375
Mwaengo, Dufton M.; Novembre, Francis J.
1998-01-01
We have previously described the development of AIDS in a chimpanzee (C499) infected with human immunodeficiency virus type 1 (HIV-1) and the subsequent pathogenic HIV-1 infection in another chimpanzee (C455) transfused with blood from C499 (F. J. Novembre et al., J. Virol. 71:4086–4091, 1997). In the present study, two virus isolates were derived from these animals: HIV-1JC from peripheral blood mononuclear cells (PBMC) of C499, and HIV-1NC from plasma of C455. These virus isolates were used to generate two infectious molecular clones, termed HIV-1JC16 and HIV-1NC7 (JC16 and NC7, respectively). Comparative analyses of the sequences of the two clones showed that they were highly interrelated but distinct. Based on heteroduplex mobility assays, JC16 and NC7 appear to represent dominant viruses in the uncloned stock population. Compared with amino acid sequences of the parental viruses HIV-1SF2, HIV-1LAV-1b, and HIV-1NDK, JC16 and NC7 showed a number of differences, including insertions, deletions, and point mutations spread throughout the genome. However, insertion/deletion footprints in several genes of both JC16 and NC7 suggested that recombination between SF2 and LAV-1b could have occurred, possibly contributing to the generation of a pathogenic virus. Comparative in vitro analyses of the molecular clones and the uncloned stocks of HIV-1JC and HIV-1NC revealed that these viruses had strikingly similar replicative abilities in mitogen-stimulated PBMC and in macrophages. Compared to the SF2 and LAV-1b isolates of HIV-1, HIV-1JC and HIV-1NC isolates were more similar to LAV-1b with respect to the ability to replicate in mitogen-stimulated PBMC and macrophages. These viruses should prove to be useful in mapping determinants of pathogenesis. PMID:9765443
Yuste, Rosario Sanchez; Frías, Carolina; López, Ana; Vallejo, Carlos; Martín, Paloma; Bellas, Carmen
2008-01-01
To compare the diagnostic value of cytology and immunohistochemistry staining (IHS) of urine samples for polyomavirus reactivation diagnosis. Sixty-eight urine samples collected from 18 immunosuppressed patients were analyzed by Papanicolaou and IHS with a JC/BK virus-specific monoclonal antibody. Overall, polyomavirus BK (BKV) was positive in 11 of 18 patients (61.1%) (3 of whom developed hemorrhagic cystitis) and in 23 of 68 urine samples (28%). Of 23 samples, 4 (17%) were positive by 1 of the 2 techniques, only. Of 23 samples, 19 (83%) were positive by both methods. In matching urine samples from the same patient, the number of BKV-infected positive cells detected by IHS in urine slides was higher than those detected by Papanicolaou staining (71.3%). The main advantage of LHS is that it allowed confirmation of BKV infection diagnosis in urine samples. IHS detected more BKV-infected cells in samples with few positive urothelial cells, which would have gone undetected if only Papanicolaou staining had been used as the BKV screening method. Urine samples testing for BKV by both techniques will improve diagnosis in asymptomatic patients, allowing early therapeutic intervention and a better clinical outcome.
Grain Size Biasing of 230Th-derived Focusing Factors in the Panama Basin
NASA Astrophysics Data System (ADS)
Loveley, M. R.; Marcantonio, F.; Lyle, M. W.; Ibrahim, R.; Wang, J. K.; Hertzberg, J. E.
2014-12-01
In this study, we attempt to understand how differing grain size classes in Panama Basin sediments may create biasing of 230Th as a constant-flux proxy. Greater amounts of 230Th are contained in fine grained particles, which, if fractionated from coarser grained counterparts may lead to biasing of 230Th-derived mass accumulation rates (MARs) and sediment focusing factors. We examined sediments that span the past 25 kyr from four new sediment cores retrieved from two different localities close to the ridges that bound the Panama Basin. Each locality contained paired sites that were seismically interpreted to have undergone sediment redistribution, i.e., thick focused sites versus thin winnowed sites. Two sediment cores were retrieved from the northern part of the Panama basin, Cocos Ridge, (MV1014-01-"4JC", 5° 44.7'N 85° 45.5' W, 1730 m depth; MV1014-01-"8JC", 6° 14.0'N 86° 2.6' W, 1993 m depth), and two were retrieved from the southern part of the basin, Carnegie Ridge, (MV1014-02-"11JC", 0° 41.6'S 85° 20.0' W, 2452 m depth; MV1014-02-"17JC" 0° 10.8'S 85° 52.0' W, 2846 m depth). Cores 4JC and 11JC lie closer to the ridge tops of the Cocos and Carnegie Ridges, respectively, and have thin sediment drapes, while deeper cores, 8JC (Cocos) and 17JC (Carnegie), have thicker sediment drapes and lie downslope from the ridge top cores. Age-model-derived sand MARs, which likely represent the vertical rain of particles that cannot be transported by bottom currents, are similar at each of the paired sites in Holocene and glacial time slices. However, 230Th-normalized MARs are about 50% lower, on average at each of the paired sites during the same time slices. Both Holocene and glacial samples from "thin" cores (4,11JC) contain, surprisingly, significant amounts (up to 50%) of the 230Th within the coarse grained (>63 μm) fraction which makes up 40-70% of the bulk samples analyzed. On the contrary, Holocene and glacial samples from "thick" cores, (8,17JC), contain the greatest amounts of 230Th (up to 49%) in the finest grain-sized fraction (<4μm), which makes up 26-40% of the bulk samples analyzed. Although, redistribution of sediment has taken place, our analysis indicates that 230Th-derived focusing factors are being overestimated at thick sites and underestimated at thin sites.
GrB-TWEAK: A Potential Novel Biologic for NSCLC Therapy
2015-09-01
72 hours. Cell viability was determined using the crystal violet staining method followed by solubilization of the dye in Sorenson’s buffer as...using the cationic dye JC-1 (JC-1 Assay Kit; MitoProbe) according to the manufacturer’s instructions, as previously described (8). For in vivo detection...mitochondrial depolarization (the loss of mitochondrial transmembrane potential as measured by green fluorescence of the JC-1 cationic dye in its
Use of hybridot assay to screen for BK and JC polyomaviruses in non-immunosuppressed patients.
Cobb, J J; Wickenden, C; Snell, M E; Hulme, B; Malcolm, A D; Coleman, D V
1987-01-01
Urine samples from 50 patients attending a genitourinary outpatient clinic and from 13 renal allograft recipients were investigated for evidence of infection with human BK and JC polyomaviruses using cytology and a new DNA hybridot assay. Forty four per cent of samples from the renal allograft recipients were positive by cytology and 75% by DNA hybridisation, indicating that hybridot assay is more sensitive than cytological screening. BK and JC viral DNA was found in 20% of the patients attending the genitourinary clinic, showing infection with BK virus and JC virus in a group of patients with clinical conditions not normally associated with immunological deficiency-a finding that has not been reported before. Images Figure PMID:3040812
Dobkin BH. Neurological rehabilitation. In: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy SL, eds. Bradley's Neurology in Clinical Practice . 7th ed. Philadelphia, PA: Elsevier; 2016:chap 57. Greenwood JC, ...
Pan, Bang-Zhen; Chen, Mao-Sheng; Ni, Jun; Xu, Zeng-Fu
2014-11-17
Jatropha curcas, whose seed content is approximately 30-40% oil, is an ideal feedstock for producing biodiesel and bio-jet fuels. However, Jatropha plants have a low number of female flowers, which results in low seed yield that cannot meet the needs of the biofuel industry. Thus, increasing the number of female flowers is critical for the improvement of Jatropha seed yield. Our previous findings showed that cytokinin treatment can increase the flower number and female to male ratio and also induce bisexual flowers in Jatropha. The mechanisms underlying the influence of cytokinin on Jatropha flower development and sex determination, however, have not been clarified. This study examined the transcriptional levels of genes involved in the response to cytokinin in Jatropha inflorescence meristems at different time points after cytokinin treatment by 454 sequencing, which gave rise to a total of 294.6 Mb of transcript sequences. Up-regulated and down-regulated annotated and novel genes were identified, and the expression levels of the genes of interest were confirmed by qRT-PCR. The identified transcripts include those encoding genes involved in the biosynthesis, metabolism, and signaling of cytokinin and other plant hormones, flower development and cell division, which may be related to phenotypic changes of Jatropha in response to cytokinin treatment. Our analysis indicated that Jatropha orthologs of the floral organ identity genes known as ABCE model genes, JcAP1,2, JcPI, JcAG, and JcSEP1,2,3, were all significantly repressed, with an exception of one B-function gene JcAP3 that was shown to be up-regulated by BA treatment, indicating different mechanisms to be involved in the floral organ development of unisexual flowers of Jatropha and bisexual flowers of Arabidopsis. Several cell division-related genes, including JcCycA3;2, JcCycD3;1, JcCycD3;2 and JcTSO1, were up-regulated, which may contribute to the increased flower number after cytokinin treatment. This study presents the first report of global expression patterns of cytokinin-regulated transcripts in Jatropha inflorescence meristems. This report laid the foundation for further mechanistic studies on Jatropha and other non-model plants responding to cytokinin. Moreover, the identification of functional candidate genes will be useful for generating superior varieties of high-yielding transgenic Jatropha.
Proteomic analysis of oil bodies in mature Jatropha curcas seeds with different lipid content.
Liu, Hui; Wang, Cuiping; Chen, Fan; Shen, Shihua
2015-01-15
To reveal the difference among three mature Jatropha curcas seeds (JcVH, variant with high lipid content; JcW, wild type and JcVL, variant with low lipid content) with different lipid content, comparative proteomics was employed to profile the changes of oil body (OB) associated protein species by using gels-based proteomic technique. Eighty-three protein species were successfully identified through LTQ-ES-MS/MS from mature JcW seeds purified OBs. Two-dimensional electrophoresis analysis of J. curcas OB associated protein species revealed they had essential interactions with other organelles and demonstrated that oleosin and caleosin were the most abundant OB structural protein species. Twenty-eight OB associated protein species showed significant difference among JcVH, JcW and JcVL according to statistical analysis. Complementary transient expression analysis revealed that calcium ion binding protein (CalBP) and glycine-rich RNA binding protein (GRP) were well targeted in OBs apart from the oleosins. This study demonstrated that ratio of lipid content to caleosins abundance was involved in the regulation of OB size, and the mutant induced by ethylmethylsulfone treatment might be related to the caleosin like protein species. These findings are important for biotechnological improvement with the aim to alter the lipid content in J. curcas seeds. The economic value of Jatropha curcas largely depends on the lipid content in seeds which are mainly stored in the special organelle called oil bodies (OBs). In consideration of the biological importance and applications of J. curcas OB in seeds, it is necessary to further explore the components and functions of J. curcas OBs. Although a previous study concerning the J. curcas OB proteome revealed oleosins were the major OB protein component and additional protein species were similar to those in other oil seed plants, these identified OB associated protein species were corresponding to the protein bands instead of protein spots in the electrophoresis gels. Furthermore, the interaction of OB associated protein species and their contribution to OB formation and stabilization are still blank. In this study, with the overall object of profiling OB protein species from mature J. curcas seeds with different lipid content, we provided a setting of comparative OB proteomics with biochemical data and transient expression to explore the core of OB associated protein species involved in the regulation of OB size and lipid accumulation. The results were important for biotechnological improvement with the aim to a global modification of lipid storage in J. curcas seeds. Meanwhile, this study gave insight into possible associations between OBs and other organelles in mature J. curcas seeds. It may represent new aspects of the biological functions of the OBs during the oil mobilization. Combined the technique of transient transformation, a newly reported protein species, glycine-rich RNA binding protein (GRP) was successfully targeted in OBs. Therefore, further molecular analysis of these protein species is warranted to verify this association and what role they have in OBs. Copyright © 2014 Elsevier B.V. All rights reserved.
Nanoscale-SiC doping for enhancing Jc and Hc2 in superconducting MgB2
NASA Astrophysics Data System (ADS)
Dou, S. X.; Braccini, V.; Soltanian, S.; Klie, R.; Zhu, Y.; Li, S.; Wang, X. L.; Larbalestier, D.
2004-12-01
The effect of nanoscale-SiC doping of MgB2 was investigated in comparison with undoped, clean-limit, and Mg-vapor-exposed samples using transport and magnetic measurements. It was found that there are two distinguishable but related mechanisms that control the critical current-density-field Jc(H ) behavior: increase of upper critical field Hc2 and improvement of flux pinning. There is a clear correlation between the critical temperature Tc, the resistivity ρ, the residual resistivity ratio RRR =R(300K)/R(40K), the irreversibility field H*, and the alloying state in the samples. The Hc2 is about the same within the measured field range for both the Mg-vapor-treated and the SiC-doped samples. However, the Jc(H ) for the latter is higher than the former in a high-field regime by an order of magnitude. Mg vapor treatment induced intrinsic scattering and contributed to an increase in Hc2. SiC doping, on the other hand, introduced many nanoscale precipitates and disorder at B and Mg sites, provoking an increase of ρ(40K ) from 1μΩcm (RRR=15) for the clean-limit sample to 300μΩcm (RRR=1.75) for the SiC-doped sample, leading to significant enhancement of both Hc2 and H * with only a minor effect on Tc. Electron energy-loss spectroscope and transmission electron microscope analysis revealed impurity phases: Mg2Si, MgO, MgB4, BOx, SixByOz, and BC at a scale below 10nm and an extensive domain structure of 2-4-nm domains in the doped sample, which serve as strong pinning centers.
Agarwal, Parinita; Dabi, Mitali; Agarwal, Pradeep K
2014-08-01
The WRKY family of transcription factors (TFs) play an intricate role in regulating the stress signaling pathways by autoregulation or may be by cross regulation through interaction with other proteins. Although WRKY TFs are considered to be plant specific, however, their presence has been reported from unicellular algae, slime mould, and gymnosperms. We have isolated the JcWRKY cDNA from an important biofuel crop Jatropha curcas growing in the wastelands of India. The JcWRKY gene has an ORF of 693 bp and encodes a 230 amino acids protein with estimated molecular mass of 25.25 kDa. JcWRKY shows close homology to FaWRKY1 and St-WRKY1. The JcWRKY contains seven potential phosphorylation sites, which might be involved in regulating its function. The transcript analysis revealed that the JcWRKY transcript gets upregulated in response to salinity, dehydration, salicylic acid (SA), methyl jasmonate (MeJa), and collar rot fungus Macrophomina. However, maximum expression is observed under SA, highlighting its role in enhancing systemic acquired resistance for disease tolerance. The JcWRKY recombinant protein showed binding to W-box of pathogenesis related-1 (PR-1) and iso1 (encoding isoamylase1) promoters. Overexpression of JcWRKY in Escherichia coli enhanced the growth of cells in NaCl, KCl, mannitol, sorbitol, SA, and MeJa treatments, indicating that it protects and promotes growth under ionic, osmotic, and chemical stresses. The enhancement in growth can be due to the regulation of stress responsive genes. Therefore, it can be used as an important gene for enhancing abiotic and biotic resistance in plants and to facilitate faster growth of E. coli cells under stress conditions for efficient expression.
#GeriMedJC: The Twitter Complement to the Traditional-Format Geriatric Medicine Journal Club.
Gardhouse, Amanda I; Budd, Laura; Yang, Seu Y C; Wong, Camilla L
2017-06-01
Twitter is a public microblogging platform that overcomes physical limitations and allows unrestricted participation beyond academic silos, enabling interactive discussions. Twitter-based journal clubs have demonstrated growth, sustainability, and worldwide communication, using a hashtag (#) to follow participation. This article describes the first year of #GeriMedJC, a monthly 1-hour live, 23-hour asynchronous Twitter-based complement to the traditional-format geriatric medicine journal club. The Twitter moderator tweets from the handle @GeriMedJC; encourages use of #GeriMedJC; and invites content experts, study authors, and followers to participate in critical appraisal of medical literature. Using the hashtag #GeriMedJC, tweets were categorized according to thematic content, relevance to the journal club, and authorship. Third-party analytical tools Symplur and Twitter Analytics were used for growth and effect metrics (number of followers, participants, tweets, retweets, replies, impressions). Qualitative analysis of follower and participant profiles was used to establish country of origin and occupation. A semistructured interview of postgraduate trainees was conducted to ascertain qualitative aspects of the experience. In the first year, @GeriMedJC has grown to 541 followers on six continents. Most followers were physicians (43%), two-thirds of which were geriatricians. Growth metrics increased over 12 months, with a mean of 121 tweets, 25 participants, and 105,831 impressions per journal club. Tweets were most often related to the article being appraised (87.5%) and ranged in thematic content from clinical practice (29%) to critical appraisal (24%) to medical education (20%). #GeriMedJC is a feasible example of using social media platforms such as Twitter to encourage international and interprofessional appraisal of medical literature. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.
Cosmetic procedures among youths: a survey of junior college and medical students in Singapore
Ng, Jia Hui; Yeak, Seth; Phoon, Natalie; Lo, Stephen
2014-01-01
INTRODUCTION Although cosmetic procedures have become increasingly popular among the younger population in recent years, limited research on this subject has been done in the Asian context. We aimed to explore the views and knowledge regarding cosmetic procedures among junior college (JC) and medical students in Singapore. METHODS In the first phase of the study, a cross-sectional, self-administered survey of 1,500 JC students aged 16–21 years from six JCs was conducted in 2010. The same survey was then conducted on a random sample of Year 2–5 medical students from an undergraduate medical school in 2011. RESULTS In total, 1,164 JC and 241 medical students responded to the surveys. There was an overall female to male ratio of 1.3:1. Of all the respondents, 2.5% of the JC students and 3.0% of the medical students admitted to having undergone cosmetic procedures. Among those who claimed to have never had cosmetic procedures done, 9.0% and 44.0% of the JC and medical students, respectively, responded that they would consider such procedures in the future. Those who disapproved of their peers undergoing cosmetic surgery comprised 35.0% of JC students and 56.8% of medical students. Among the JC and medical students, 52.0% and 36.1%, respectively, were unaware of any risks associated with cosmetic procedures. CONCLUSION The younger population is increasingly accepting of cosmetic procedures. However, there is a general lack of understanding of the risks associated with such procedures. Education of both the general public and medical students may help prevent potential medicolegal issues. PMID:25189303
Duan, Peipei; Cai, Feng; Luo, Yongting; Chen, Yangxi; Zou, Shujuan
2015-09-01
Isoenzyme c of horseradish peroxidase (HRP-C) is widely used in enzyme immunoassay combined with chemiluminescence (CL) detection. For this application, HRP-C activity measurement is usually based on luminol oxidation in the presence of hydrogen peroxide (H2O2). However, this catalysis reaction was enhancer dependent. In this study, we demonstrated that Jatropha curcas peroxidase (JcGP1) showed high efficiency in catalyzing luminol oxidation in the presence of H2O2. Compared with HRP-C, the JcGP1-induced reaction was enhancer independent, which made the enzyme-linked immunosorbent assay (ELISA) simpler. In addition, the JcGP1 catalyzed reaction showed a long-term stable CL signal. We optimized the conditions for JcGP1 catalysis and determined the favorable conditions as follows: 50 mM Tris buffer (pH 8.2) containing 10 mM H2 O2, 14 mM luminol and 0.75 M NaCl. The optimum catalysis temperature was 30°C. The detection limit of JcGP1 under optimum condition was 0.2 pM. Long-term stable CL signal combined with enhancer-independent property indicated that JcGP1 might be a valuable candidate peroxidase for clinical diagnosis and enzyme immunoassay with CL detection. Copyright © 2014 John Wiley & Sons, Ltd.
Wang, Haibo; Ao, Pingxing; Yang, Shuanglong; Zou, Zhurong; Wang, Shasha; Gong, Ming
2015-03-01
Proline dehydrogenase (ProDH) (EC 1.5.99.8) is a key enzyme in the catabolism of proline. The enzyme JcProDH and its complementary DNA (cDNA) were isolated from Jatropha curcas L., an important woody oil plant used as a raw material for biodiesels. It has been classified as a member of the Pro_dh superfamily based on multiple sequence alignment, phylogenetic characterization, and its role in proline catabolism. Its cDNA is 1674 bp in length with a complete open reading frame of 1485 bp, which encodes a polypeptide chain of 494 amino acids with a predicted molecular mass of 54 kD and a pI of 8.27. Phylogenetic analysis indicated that JcProDH showed high similarity with ProDH from other plants. Reverse transcription PCR (RT-PCR) analysis revealed that JcProDH was especially abundant in the seeds and flowers but scarcely present in the stems, roots, and leaves. In addition, the expression of JcProDH increased in leaves experiencing environmental stress such as cold (5 °C), heat (42 °C), salt (300 mM), and drought (30 % PEG6000). The JcProDH protein was successfully expressed in the yeast strain INVSc1 and showed high enzyme activity in proline catabolism. This result confirmed that the JcProDH gene negatively participated in the stress response.
... Meningococcemia associated purpura Necrosis of the toes References Kumar V, Abbas AK, Aster JC. Cellular responses to ... and toxic insults: adaptation, injury, and death. In: Kumar V, Abbas AK, Aster JC, eds. Robbins and ...
... A. Bones, joints, and soft tissue tumors. In: Kumar V, Abbas AK, Aster JC, eds. Robbins and ... ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 26. Kumar V, Abbas AK, Aster JC. Cellular responses to ...
... to a part of the brain called the brainstem Tumor in the top of the lung Injections ... 424. Thurtell MJ, Rucker JC. Pupillary and eyelid abnormalities. In: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy ...
... 12th ed. Philadelphia, PA: Elsevier; 2017:1061-1067. Kumar V, Abbas AK, Aster JC. Cellular responses to ... and toxic insults: adaptation, injury, and death. In: Kumar V, Abbas AK, Aster JC, eds. Robbins and ...
1992-12-01
longer in the Gulf of Mexico and the patrol, in such areas as th(. Florida Straits have learned what Yucatan Peninsula and from naval Ii means to look down...same performed on conventional deep - containing shallow cracks aW/W < J value have markedly different crack specimens The increa-ed 02, are commonly...the Jc values ’for characterization of the crack-tip atW ratio effects on the measured corresponding deep -crack spec- stress field Moreover, these
1982-01-01
as a potential tailed deer neutralized both JC and KEY viruses , amplifying host of this virus . Sika deer, and cot- Evidence based on PRN.,, titers...Bunyaviridae, Cali- fornia serogroup). Neutralizing (N) antibody to JC virus was most prevalent in white-tailed deer, sika deer, cottontail rabbits and... viruses also was found in raccoons, horses and humans. JC and/or KEY virus N antibodies were not demonstrable in sera of several other species of
9th Annual Systems Engineering Conference: Volume-1 Monday Tutorial
2006-10-26
Joint Integrating Concepts (JIC) • Forceable Entry Ops • Undersea Superiority • Global Strike Ops • Sea-Basing Ops • Air & Missile Defense • JC2 • Joint...Forceable Entry Ops o Undersea Superiority o Global Strike Ops o Sea-Basing Ops o Air & Missile Defense o JC2 o Joint Logistics Includes an illustrative... Undersea Superiority • Global Strike Ops • Sea-Basing Ops • Air & Missile Defense • JC2 • Joint Logistics Universal Joint Task List (UJTL) • Strategic
2014-01-01
Background Triacylglycerols (TAGs) are the most abundant form of storage oil in plants. They consist of three fatty acid chains (usually C16 or C18) covalently linked to glycerol. SDP1 is a specific lipase for the first step of TAG catabolism in Arabidopsis seeds. Arabidopsis mutants deficient in SDP1 accumulate high levels of oils, probably due to blockage in TAG degradation. We applied this knowledge from the model plant, Arabidopsis thaliana, to engineer increased seed oil content in the biodiesel plant Jatropha curcas using RNA interference (RNAi) technology. Results As Jatropha is a biodiesel crop, any significant increase in its seed oil content would be an important agronomic trait. Using A. thaliana as a model plant, we found that a deficiency of SDP1 led to higher TAG accumulation and a larger number of oil bodies in seeds compared with wild type (Columbia-0; Col-0). We cloned Jatropha JcSDP1, and verified its function by complementation of the Arabidopsis sdp1-5 mutant. Taking advantage of the observation with Arabidopsis, we used RNAi technology to generate JcSDP1 deficiency in transgenic Jatropha. We found that Jatropha JcSDP1-RNAi plants accumulated 13 to 30% higher total seed storage lipid, along with a 7% compensatory decrease in protein content, compared with control (CK; 35S:GFP) plants. Free fatty acid (FFA) content in seeds was reduced from 27% in control plants to 8.5% in JcSDP1-RNAi plants. Conclusion Here, we showed that SDP1 deficiency enhances seed oil accumulation in Arabidopsis. Based on this result, we generated SDP1-deficient transgenic Jatropha plants using by RNAi technology with a native JcSDP1 promoter to silence endogenous JcSDP1 expression. Seeds of Jatropha JcSDP1-RNAi plants accumulated up to 30% higher total lipid and had reduced FFA content compared with control (CK; 35S:GFP) plants. Our strategy of improving an important agronomic trait of Jatropha can be extended to other oil crops to yield higher seed oil. PMID:24606605
Analysis of JC virus DNA replication using a quantitative and high-throughput assay
Shin, Jong; Phelan, Paul J.; Chhum, Panharith; Bashkenova, Nazym; Yim, Sung; Parker, Robert; Gagnon, David; Gjoerup, Ole; Archambault, Jacques; Bullock, Peter A.
2015-01-01
Progressive Multifocal Leukoencephalopathy (PML) is caused by lytic replication of JC virus (JCV) in specific cells of the central nervous system. Like other polyomaviruses, JCV encodes a large T-antigen helicase needed for replication of the viral DNA. Here, we report the development of a luciferase-based, quantitative and high-throughput assay of JCV DNA replication in C33A cells, which, unlike the glial cell lines Hs 683 and U87, accumulate high levels of nuclear T-ag needed for robust replication. Using this assay, we investigated the requirement for different domains of T-ag, and for specific sequences within and flanking the viral origin, in JCV DNA replication. Beyond providing validation of the assay, these studies revealed an important stimulatory role of the transcription factor NF1 in JCV DNA replication. Finally, we show that the assay can be used for inhibitor testing, highlighting its value for the identification of antiviral drugs targeting JCV DNA replication. PMID:25155200
NASA Astrophysics Data System (ADS)
Elsabawy, Khaled M.; Fallatah, Ahmed M.; Alharthi, Salman S.
2018-07-01
For the first time high energy Helium-Silver laser which belongs to the category of metal-vapor lasers applied as microstructure promoter for optimally Ir-doped-MgB2sample. The Ir-optimally doped-Mg0.94Ir 0.06B2 superconducting sample was selected from previously published article for one of authors themselves. The samples were irradiated by a three different doses 1, 2 and 3 h from an ultrahigh energy He-Ag-Laser with average power of 103 W/cm2 at distance of 3 cm. Superconducting measurements and micro-structural features were investigated as function of He-Ag Laser irradiation doses. Results indicated that irradiations via an ultrahigh energy He-Ag-Laser promoted grains to lower sizes and consequently measured Jc's values enhanced and increased. Furthermore Tc-offsets for all irradiated samples are better than non-irradiated Mg0.94Ir 0.06B2.
NASA Astrophysics Data System (ADS)
Yoshihara, K.; van Mierlo, M.; Ng, A.; Shankar Kumar, B.; De Ruiter, A.; Komatsu, Y.; Horiguchi, H.; Hashimoto, H.
2008-08-01
This paper introduces the Japan Canada Joint Collaboration Satellites - Formation Flying (JC2Sat-FF) project. JC2Sat-FF is a joint project between the Canadian Space Agency (CSA) and the Japan Aerospace Exploration Agency (JAXA) with the end goal of building, launching and operating two 20kg- class nanosatellites for technical demonstration of formation flight (FF) using differential drag technique, relative navigation using commercial off-the-shelf (COTS) dual band GPS receivers and far infra-red radiance measurement. A unique aspect of this project is that the two JC2Sats are developed by a united small team consisting of engineers and researchers from both agencies. Technical exchange in this international team gives stimulation to the members and generates a synergistic effect for the project.
Genome-wide analysis of the WRKY gene family in physic nut (Jatropha curcas L.).
Xiong, Wangdan; Xu, Xueqin; Zhang, Lin; Wu, Pingzhi; Chen, Yaping; Li, Meiru; Jiang, Huawu; Wu, Guojiang
2013-07-25
The WRKY proteins, which contain highly conserved WRKYGQK amino acid sequences and zinc-finger-like motifs, constitute a large family of transcription factors in plants. They participate in diverse physiological and developmental processes. WRKY genes have been identified and characterized in a number of plant species. We identified a total of 58 WRKY genes (JcWRKY) in the genome of the physic nut (Jatropha curcas L.). On the basis of their conserved WRKY domain sequences, all of the JcWRKY proteins could be assigned to one of the previously defined groups, I-III. Phylogenetic analysis of JcWRKY genes with Arabidopsis and rice WRKY genes, and separately with castor bean WRKY genes, revealed no evidence of recent gene duplication in JcWRKY gene family. Analysis of transcript abundance of JcWRKY gene products were tested in different tissues under normal growth condition. In addition, 47 WRKY genes responded to at least one abiotic stress (drought, salinity, phosphate starvation and nitrogen starvation) in individual tissues (leaf, root and/or shoot cortex). Our study provides a useful reference data set as the basis for cloning and functional analysis of physic nut WRKY genes. Copyright © 2013 Elsevier B.V. All rights reserved.
Notes on Finite Cooperative Games,
1981-02-01
solution concepts: .-%. P Th. 1: (VIN) M (r) + o (Peleg) 11 r STh. II: (VI) K(r) + 0 (Maschler & Peleg) Donald Brown and Peter Loeb, "The Values of...C. If ZeJ and ySZ ipso facto ZeC C. Since K K 0jC- for any j, CcC, OJC. Then C is a filter and C 3. By Zorn’s Lemma there exists UI such that UI is
Gulf of California Response to Hurricane Juliette
2010-01-01
desert. J. Geophys. Res. 109, C03043. doi:10.1029/2003JC001938. Barth, A., Alvera -Azcárate, A., Weisberg, R.H., 2008a. A nested model study of the Loop...Current generated variability and its impact on the West Florida Shelf. J. Geophys. Res. 113, C05009. doi:10.1029/2007JC004492. Barth, A., Alvera ...C08033. doi:10.1029/2007JC004585. Barth, A., Alvera -Azcárate, A., Weisberg, R.H., 2008c. Benefit of nesting a regional model into a large-scale ocean model
Ji, Chenhui; Xue, Guo-Fang; Lijun, Cao; Feng, Peng; Li, Dongfang; Li, Lin; Li, Guanglai; Hölscher, Christian
2016-03-01
The incretins glucagon-like peptide 1 (GLP-1) and glucose dependent insulinotropic polypeptide (GIP) are growth factors with neuroprotective properties. GLP-1 mimetics are on the market as treatments for type 2 diabetes and are well tolerated. Both GLP-1 and GIP mimetics have shown neuroprotective properties in animal models of Parkinson's and Alzheimer's disease. In addition, the GLP-1 mimetic exendin-4 has shown protective effects in a clinical trial in Parkinson's disease (PD) patients. Novel GLP-1/GIP dual-agonist peptides have been developed and are tested in diabetic patients. Here we demonstrate the neuroprotective effects of a novel dual agonist (DA-JC1) in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. MPTP was injected once-daily (20 mg/kg i.p.) for 7 days, and the dual agonist was injected 30 min later i.p. (50 nmol/kg bw). The PI3k inhibitor LY294002 (0.6 mg/kg i.v.) was co-injected in one group. DA-JC1 reduced or reversed most of the MPTP induced motor impairments in the rotarod and in a muscle strength test. The number of tyrosine hydroxylase (TH) positive neurons in the substantia nigra (SN) was reduced by MPTP and increased by DA-JC1. The ratio of anti-inflammatory Bcl-2 to pro-inflammatory BAX as well as the activation of the growth factor kinase Akt was reduced by MPTP and reversed by DA-JC1. The PI3k inhibitor had only limited effect on the DA-JC1 drug effect. Importantly, levels of the neuroprotective brain derived neurotropic factor (BDNF) were reduced by MPTP and enhanced by DA-JC1. The results demonstrate that DA-JC1 shows promise as a novel treatment for PD. Copyright © 2016. Published by Elsevier B.V.
Genetics Home Reference: intranuclear rod myopathy
... Lochmüller H, Graziano C, Mitrani-Rosenbaum S, Twomey D, Sparrow JC, Beggs AH, Nowak KJ. Mutations and polymorphisms ... Epub 2008 Jun 24. Review. Citation on PubMed Sparrow JC, Nowak KJ, Durling HJ, Beggs AH, Wallgren- ...
High Temperature Superconductor Josephson Weak Links
NASA Technical Reports Server (NTRS)
Hunt, B. D.; Barner, J. B.; Foote, M. C.; Vasquez, R. C.
1993-01-01
High T_c edge-geometry SNS microbridges have been fabricated using ion-damaged YBa_2Cu_3O_(7-x) (YBCO) and a nonsuperconducting phase of YBCO (N-YBCO) as normal metals. Optimization of the ion milling process used for YBCO edge formation and cleaning has resulted in ion-damage barrier devices which exhibit I-V characteristics consistent with the Resistively-Shunted-Junction (RSJ) model, with typical current densities (J_c) of approximately 5 x 10^6 A/cm^2 at 4.2 K. Characterization of N-YBCO films suggests that N-YBCO is the orthorhombic YBCO phase with oxygen disorder suppressing T_c...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Xu, Xingchen; Peng, Xuan; Sumption, Michael
The internal oxidation technique can generate ZrO2 nano particles in Nb3Sn strands, which markedly refine the Nb3Sn grain size and boost the high-field critical current density (Jc). This article summarizes recent efforts on implementing this technique in practical Nb3Sn wires and adding Ti as a dopant. It is demonstrated that this technique can be readily incorporated into the present Nb3Sn conductor manufacturing technology. Powder-in-tube (PIT) strands with fine subelements (~25 µm) based on this technique were successfully fabricated, and proper heat treatments for oxygen transfer were explored. Future work for producing strands ready for applications is proposed.
NASA Astrophysics Data System (ADS)
Setoyama, Yui; Shimoyama, Jun-ichi; Motoki, Takanori; Kishio, Kohji; Awaji, Satoshi; Kon, Koichi; Ichikawa, Naoki; Inamori, Satoshi; Naito, Kyogo
2016-12-01
Effects of densification of precursor disks on the density of residual voids and critical current properties for YBCO melt-textured bulk superconductors were systematically investigated. Six YBCO bulks were prepared from precursor pellets with different initial particle sizes of YBa2Cu3Oy (Y123) powder and applied pressures for pelletization. It was revealed that use of finer Y123 powder and consolidation using cold-isostatic-pressing (CIP) with higher pressures result in reduction of residual voids at inner regions of bulks and enhance Jc especially under low fields below the second peak.
Yokosuka, Tomoko; Goto, Hiroaki; Fujii, Hisaki; Naruto, Takuya; Takeuchi, Masanobu; Tanoshima, Reo; Kato, Hiromi; Yanagimachi, Masakatsu; Kajiwara, Ryosuke; Yokota, Shumpei
2013-12-01
The purpose of the study is to establish a simple and relatively inexpensive flow cytometric chemosensitivity assay (FCCA) for leukemia to distinguish leukemic blasts from normal leukocytes in clinical samples. We first examined whether the FCCA with the mitochondrial membrane depolarization sensor, 5, 50, 6, 60-tetrachloro-1, 10, 3, 30 tetraethyl benzimidazolo carbocyanine iodide (JC-1), could detect drug-induced apoptosis as the conventional FCCA by annexin V/7-AAD detection did and whether it was applicable in the clinical samples. Second, we compared the results of the FCCA for prednisolone (PSL) with clinical PSL response in 18 acute lymphoblastic leukemia (ALL) patients to evaluate the reliability of the JC-1 FCCA. Finally, we performed the JC-1 FCCA for bortezomib (Bor) in 25 ALL or 11 acute myeloid leukemia (AML) samples as the example of the clinical application of the FCCA. In ALL cells, the results of the JC-1 FCCA for nine anticancer drugs were well correlated with those of the conventional FCCA using anti-annexin V antibody (P < 0.001). In the clinical samples from 18 children with ALL, the results of the JC-1 FCCA for PSL were significantly correlated with the clinical PSL response (P = 0.005). In ALL samples, the sensitivity for Bor was found to be significantly correlated with the sensitivity for PSL (P = 0.005). In AML samples, the Bor sensitivity was strongly correlated with the cytarabine sensitivity (P = 0.0003). This study showed the reliability of a relatively simple and the FCCA using JC-1, and the possibility for the further clinical application.
Wenke, Rachel J; Thomas, Rae; Hughes, Ian; Mickan, Sharon
2018-05-09
Journal clubs (JC) may increase clinicians' evidence-based practice (EBP) skills and facilitate evidence uptake in clinical practice, however there is a lack of research into their effectiveness in allied health. We investigated the effectiveness of a structured JC that is Tailored According to Research Evidence And Theory (TREAT) in improving EBP skills and practice compared to a standard JC format for allied health professionals. Concurrently, we explored the feasibility of implementing TREAT JCs in a healthcare setting, by evaluating participating clinicians' perceptions and satisfaction. We conducted an explanatory mixed methods study involving a cluster randomised controlled trial with a nested focus group for the intervention participants. Nine JCs with 126 allied health participants were randomly allocated to receive either the TREAT or standard JC format for 1 h/month for 6 months. We conducted pre-post measures of EBP skills and attitudes using the EBP questionnaire and Assessing Competence in Evidence-Based Medicine tool and a tailored satisfaction and practice change questionnaire. Post-intervention, we also conducted a focus group with TREAT participants to explore their perceptions of the format. There were no significant differences between JC formats in EBP skills, knowledge or attitudes or influence on clinical practice, with participants maintaining intermediate level skills across time points. Participants reported significantly greater satisfaction with the organisation of the TREAT format. Participants in both groups reported positive changes to clinical practice. Perceived outcomes to the TREAT format and facilitating mechanisms were identified including the use of an academic facilitator, group appraisal approach and consistent appraisal tools which assisted skill development and engagement. It is feasible to implement an evidence-based JC for allied health clinicians. While clinicians were more satisfied with the TREAT format, it did not significantly improve their EBP skills, attitudes, knowledge and/or practice, when compared to the standard format. The use of an academic facilitator, group based critical appraisal, and the consistent use of appraisal tools were perceived as useful components of the JC format. A structured JC may maintain EBP skills in allied health clinicians and facilitate engagement, however additional training may be required to further enhance EBP skills. ACTRN12616000811404 Retrospectively registered 21 June 2016.
Demonstration of the Jaynes-Cummings ladder with Rydberg-dressed atoms
Lee, Jongmin; Martin, Michael J.; Jau, Yuan-Yu; ...
2017-04-06
Here, we observe the nonlinearity of the Jaynes-Cummings (JC) ladder in the Autler-Townes spectroscopy of the hyperfine ground states for a Rydberg-dressed two-atom system. The role of the two-level system in the JC model is played by the presence or absence of a collective Rydberg excitation, and the bosonic mode manifests as the number n of single-atom spin flips, symmetrically distributed between the atoms. We also measure the normal-mode splitting and √ n nonlinearity as a function of detuning and Rabi frequency, thereby experimentally establishing the isomorphism with the JC model.
Constitutive Model Constants for Al7075-T651 and Al7075-T6
NASA Astrophysics Data System (ADS)
Brar, Nachhatter; Joshi, Vasant; Harris, Bryan
2009-06-01
Aluminum 7075-T651 and 7075-T6 are characterized at quasi-static and high strain rates to determine Johnson-Cook (J-C) strength and fracture model constants. Constitutive model constants are required as input to computer codes to simulate projectile (fragment) impact or similar impact events on structural components made of these material. J-C strength model constants (A, B, n, C, and m) for the two alloys are determined from tension stress-strain data at room and high temperature to 250^oC. J-C strength model constants for Al7075-T651 are: A=527 MPa, B=676 MPa, n=0.71, C=0.017, and m=1.61 and for Al7075-T6: A = 546 MPa, B = 674 MPa, n = 0.72, C = 0.059, and m =1.56. J-C fracture model constants are determined form quasi-static and high strain rate/high temperature tests on notched and smooth tension specimens. J-C fracture model constants for the two alloys are: Al7075-T651; D1 = 0.110, D2 = 0.573, D3= -3.4446, D4 = 0.016, and D 5= 1.099 and Al7075-T6; D1= 0.451 D2= -0.952 D3= -.068, D4 =0.036, and D5 = 0.697.
Superconducting, magnetic and magnetotransport properties of FeTe1-xSex single crystals
NASA Astrophysics Data System (ADS)
Kumar, Rohit; Sudesh, Varma, G. D.
2018-05-01
The single crystalline samples with compositions FeTe1-xSex (0.25 ≤ x ≤ 0.50) have been prepared via self-flux method and the superconducting, magnetic and magnetotransport properties of the grown crystals were investigated. The superconducting onset temperatures have been determined from the measurements of zero field cooled magnetization and resistance with temperatures. In the present case, highest superconducting transition temperature TC (onset) ˜ 15 K has been obtained for x=0.5. The HC2 (T=0 K) values have been estimated by fitting the experimental HC2 - T plots with WHH model. The highest HC2(0) has been obtained for x=0.5. The activation energy of the thermally activated flux flow has been found from the broadening of superconducting transition in an applied magnetic field using the Arrhenius law. Our results show that the activation energy (U0) decreases with the increasing magnetic field. Furthermore, the magnetization measurements for x=0.4 and 0.5 samples have been performed at T=5 K in the magnetic field range ±7 T to estimate critical current density at different applied magnetic fields using Bean formula. We see that the sample x=0.5 has higher values of JC as compared to that of x=0.4 at all magnetic fields. This is in conformity with the behavior of U0-H plots.
NASA Astrophysics Data System (ADS)
Brandt, Ernst Helmut
1998-09-01
The ac susceptibility χ=χ'-iχ'' of superconductor cylinders of finite length in a magnetic field applied along the cylinder axis is calculated using the method developed in the preceding paper, part I. This method does not require any approximation of the infinitely extended magnetic field outside the cylinder or disk but directly computes the current density J inside the superconductor. The material is characterized by a general current-voltage law E(J), e.g., E(J)=Ec[J/Jc(B)]n(B), where E is the electric field, B=μ0H the magnetic induction, Ec a prefactor, Jc the critical current density, and n>=1 the creep exponent. For n>1, the nonlinear ac susceptibility is calculated from the hysteresis loops of the magnetic moment of the cylinder, which is obtained by time integration of the equation for J(r,t). For n>>1 these results go over into the Bean critical state model. For n=1, and for any linear complex resistivity ρac(ω)=E/J, the linear ac susceptibility is calculated from an eigenvalue problem which depends on the aspect ratio b/a of the cylinder or disk. In the limits b/a<<1 and b/a>>1, the known results for thin disks in a perpendicular field and long cylinders in a parallel field are reproduced. For thin disks in a perpendicular field, at large frequencies χ(ω) crosses over to the behavior of slabs in parallel geometry since the magnetic field lines are expelled and have to flow around the disk. The results presented may be used to obtain the nonlinear or linear resistivity from contact-free magnetic measurements on superconductors of realistic shape.
Ohtsuka, Masayuki; Miyakawa, Shuichi; Nagino, Masato; Takada, Tadahiro; Miyazaki, Masaru
2015-03-01
The 3(rd) English edition of the Japanese classification of the biliary tract cancers (JC) is now available in this journal. The primary aim of this revision is to provide all clinicians and researchers with a common language of cancer staging at an international level. On the other hand, there are several important issues that should be solved for the optimization of the staging system. Revision concepts and major revision points of the 3(rd) English edition of the JC were reviewed. Furthermore, comparing with the 7(th) edition of staging system developed by the Union for International Cancer Control (UICC) and the American Joint Committee on Cancer (AJCC), distinctive points in the JC was discussed. In this edition of the JC, the same stage groupings as those in the UICC/AJCC staging system were basically adopted. T, N, and M categories were also identical in principle with those in the UICC/AJCC staging system, although slight modifications were proposed as the "Japanese rules". As distinctive points, perihilar cholangiocarcinomas and ampullary region carcinomas were clearly defined. Intraepithelial tumor was discriminated from invasive carcinoma at ductal resection margins. Classifications of site-specific surgical margin status remained in this edition. Histological classification was based on that in the former editions of the JC, but adopted some parts of the World Health Organization classification. The JC now share its staging system of the biliary tact carcinomas with the UICC/AJCC staging system. Future validation of the "Japanese rules" could provide important evidence to make globally standardized staging system. © 2015 Japanese Society of Hepato-Biliary-Pancreatic Surgery.
Publications - RDF 2002-1 | Alaska Division of Geological & Geophysical
., Clautice, K.H., Flynn, R.L., Grady, J.C., Munly, W.C., and Johnson, M.R. Publication Date: Aug 2002 ., Flynn, R.L., Grady, J.C., Munly, W.C., and Johnson, M.R., 2002, Major-oxide, minor-oxide, trace-element
El-Cheikh, Jean; Fürst, Sabine; Casalonga, Francois; Crocchiolo, Roberto; Castagna, Luca; Granata, Angela; Oudin, Claire; Faucher, Catherine; Berger, Pierre; Sarran, Anthony; Blaise, Didier
2012-01-01
We report here the case of progressive multifocal leukoencephalopathy (PML) related to human polyomavirus JC (JCV) infection after an allogeneic transplantation with umbilical cord blood cells in 59-year-old woman with follicular Non Hodgkin lymphoma. She presented with dysphagia and weakness; magnetic resonance imaging demonstrated marked signal abnormality in the sub-cortical white matter of the left frontal lobe and in the posterior limb of the right internal capsule. Polymerase chain reaction (PCR) analysis of the cerebrospinal fluid (CSF) was positive for John Cunningham (JC) virus. JC viral DNA in the CSF was positive, establishing the diagnosis of PML. Brain biopsy was not done. Extensive investigations for other viral infections seen in immuno-compromised patients were negative. The patient's neurologic deficits rapidly increased throughout her hospital stay, and she died one month after the diagnosis. These findings could have practical implications and demonstrate that in patients presenting neurological symptoms and radiological signs after UCBT, the JCV encephalitis must be early suspected.
El-Cheikh, Jean; Fürst, Sabine; Casalonga, Francois; Crocchiolo, Roberto; Castagna, Luca; Granata, Angela; Oudin, Claire; Faucher, Catherine; Berger, Pierre; Sarran, Anthony; Blaise, Didier
2012-01-01
We report here the case of progressive multifocal leukoencephalopathy (PML) related to human polyomavirus JC (JCV) infection after an allogeneic transplantation with umbilical cord blood cells in 59-year-old woman with follicular Non Hodgkin lymphoma. She presented with dysphagia and weakness; magnetic resonance imaging demonstrated marked signal abnormality in the sub-cortical white matter of the left frontal lobe and in the posterior limb of the right internal capsule. Polymerase chain reaction (PCR) analysis of the cerebrospinal fluid (CSF) was positive for John Cunningham (JC) virus. JC viral DNA in the CSF was positive, establishing the diagnosis of PML. Brain biopsy was not done. Extensive investigations for other viral infections seen in immuno-compromised patients were negative. The patient’s neurologic deficits rapidly increased throughout her hospital stay, and she died one month after the diagnosis. These findings could have practical implications and demonstrate that in patients presenting neurological symptoms and radiological signs after UCBT, the JCV encephalitis must be early suspected. PMID:22811792
YBa_2Cu_3O_{7-δ} : in pursuit of the ideal microstructure
NASA Astrophysics Data System (ADS)
Smith, D. S.; Suasmoro, S.; Lejeune, M.; Rabier, J.; Denanot, M. F.; Heintz, J. M.; Magro, C.; Bonnet, J. P.
1992-02-01
This paper examines the role of different factors in the microstructure of ceramic YBa2Cu3O{7-δ} with emphasis on its electrical response. In particular we discuss : 1. the effect of microstructural variations on j_c and ρ_{300}, 2. measurement of j_c, 3. the presence of minor phases and carbonates, 4. oxygen uptake and microcracks, 5. plastic deformation and related structural defects. Dans cet article, nous examinons d'une part la réponse électrique de céramiques supraconductrices massives de type YBa2Cu3O{7-δ} et d'autre part sa relation avec la microstructure. Nous présenterons successivement : 1. L'incidence de modifications microstructurales sur les valeurs de j_c et ρ_{300}, 2. les mesures expérimentales de j_c, 3. la présence de phases minoritaires et de carbonates, 4. la reprise d'oxygène et la microfissuration, 5. la déformation plastique et les défauts structuraux associés.
Lizarondo, Lucylynn M; Grimmer-Somers, Karen; Kumar, Saravana; Crockett, Alan
2012-10-29
Although allied health is considered to be one 'unit' of healthcare providers, it comprises a range of disciplines which have different training and ways of thinking, and different tasks and methods of patient care. Very few empirical studies on evidence-based practice (EBP) have directly compared allied health professionals. The objective of this study was to examine the impact of a structured model of journal club (JC), known as iCAHE (International Centre for Allied Health Evidence) JC, on the EBP knowledge, skills and behaviour of the different allied health disciplines. A pilot, pre-post study design using maximum variation sampling was undertaken. Recruitment was conducted in groups and practitioners such as physiotherapists, occupational therapists, speech pathologists, social workers, psychologists, nutritionists/dieticians and podiatrists were invited to participate. All participating groups received the iCAHE JC for six months. Quantitative data using the Adapted Fresno Test (McCluskey & Bishop) and Evidence-based Practice Questionnaire (Upton & Upton) were collected prior to the implementation of the JC, with follow-up measurements six months later. Mean percentage change and confidence intervals were calculated to compare baseline and post JC scores for all outcome measures. The results of this study demonstrate variability in EBP outcomes across disciplines after receiving the iCAHE JC. Only physiotherapists showed statistically significant improvements in all outcomes; speech pathologists and occupational therapists demonstrated a statistically significant increase in knowledge but not for attitude and evidence uptake; social workers and dieticians/nutritionists showed statistically significant positive changes in their knowledge, and evidence uptake but not for attitude. There is evidence to suggest that a JC such as the iCAHE model is an effective method for improving the EBP knowledge and skills of allied health practitioners. It may be used as a single intervention to facilitate evidence uptake in some allied health disciplines but may need to be integrated with other strategies to influence practice behaviour in other practitioners. An in-depth analysis of other factors (e.g. individual, contextual, organisational), or the relative contribution of these variables is required to better understand the determinants of evidence uptake in allied health.
2012-01-01
Background Although allied health is considered to be one 'unit' of healthcare providers, it comprises a range of disciplines which have different training and ways of thinking, and different tasks and methods of patient care. Very few empirical studies on evidence-based practice (EBP) have directly compared allied health professionals. The objective of this study was to examine the impact of a structured model of journal club (JC), known as iCAHE (International Centre for Allied Health Evidence) JC, on the EBP knowledge, skills and behaviour of the different allied health disciplines. Methods A pilot, pre-post study design using maximum variation sampling was undertaken. Recruitment was conducted in groups and practitioners such as physiotherapists, occupational therapists, speech pathologists, social workers, psychologists, nutritionists/dieticians and podiatrists were invited to participate. All participating groups received the iCAHE JC for six months. Quantitative data using the Adapted Fresno Test (McCluskey & Bishop) and Evidence-based Practice Questionnaire (Upton & Upton) were collected prior to the implementation of the JC, with follow-up measurements six months later. Mean percentage change and confidence intervals were calculated to compare baseline and post JC scores for all outcome measures. Results The results of this study demonstrate variability in EBP outcomes across disciplines after receiving the iCAHE JC. Only physiotherapists showed statistically significant improvements in all outcomes; speech pathologists and occupational therapists demonstrated a statistically significant increase in knowledge but not for attitude and evidence uptake; social workers and dieticians/nutritionists showed statistically significant positive changes in their knowledge, and evidence uptake but not for attitude. Conclusions There is evidence to suggest that a JC such as the iCAHE model is an effective method for improving the EBP knowledge and skills of allied health practitioners. It may be used as a single intervention to facilitate evidence uptake in some allied health disciplines but may need to be integrated with other strategies to influence practice behaviour in other practitioners. An in-depth analysis of other factors (e.g. individual, contextual, organisational), or the relative contribution of these variables is required to better understand the determinants of evidence uptake in allied health. PMID:23106851
Micro Computer Feedback Report for the Strategic Leader Development Inventory
1993-05-01
POS or NEG variables CALL CREATE MEM DIR ;make a memory directory JC SELS ;exat I error CALL SELECT-SCREEN ;dlsplay select screen JC SEL4 ;no flles in...get keyboaI Input CMP AL,1Bh3 ;ls I an Esc key ? JNZ SEL2 ;X not goto nrod test G-95 JMP SEL4 ;Exit SEL2: CMP AL,OOh Iskapick? JZ SEL ;I YES exit loop...position CALL READ DATE ;gat DOS daoe od 4e CALL F4ND -ERO ;kxlae OW In data ue JC SEL.5 SEL4 : CALL RELEASE MEM DIR ;release meu block CLC ;cler carry fag
1975-09-01
unit volume of conductor is: k2 2 dB 2 W" - 1 -PV : •iw2 1d11TII-3- 2 wihen the superconductor is in the normal state and: k - 2 dB I j P/ dB...C 2 -Bc ha 2 + 2 2 ’ -.4) ic ic B ~ h 2 .2t J P(-a~d) - (-• + 2_-- + 1 ) Jc Jc In the region d<x<a Jc =ici and the local power dissipation per unit ... unit length ever the whole of the circu- lar cross section is: ( 1 2 = x dh I4 :ross section
Connectivity, Doping, and Anisotropy in Highly Dense Magnesium Diboride (MgB2)
NASA Astrophysics Data System (ADS)
Li, Guangze
Magnesium diboride (MgB2) is a superconducting material which can be potentially used in many applications such as magnetic resonance imaging system (MRI), wind turbine generators and high energy physics facilities. The major advantages of MgB2 over other superconductors include its relatively high critical temperature of about 39 K, its low cost of raw materials, its simple crystal structure, and its round multifilament form when in the form of superconducting wires. Over the past fourteen years, much effort has been made to develop MgB2 wires with excellent superconducting properties, particularly the critical current density J c. However, this research has been limited by technical difficulties such as high porosity and weak connectivity in MgB2, relatively small flux pinning strength, low upper critical field B c2 and relatively high anisotropy. The goal of this dissertation is to understand the relationship between superconducting properties, microstructure, and reaction mechanisms in MgB 2. In particular, the influences of connectivity, B c2, anisotropy and flux pinning were investigated in terms of the effects of these variables on the Jcs and n-values of MgB2 superconducting wires (n-value is a parameter which indicates the sharpness of resistive V-I transition). The n -values of traditional "Powder in Tube (PIT)" processed MgB2 wires were improved by optimizing precursor species after the identification of microstructural defects such as so-called "sausaging problems". Also, it was found that "high porosity and weak connectivity" was one of the most critical issues which limited the J c performance in typical MgB2. To overcome this problem, highly dense, well-connected MgB2 conductors were successfully fabricated by adopting an innovative "Advanced Internal Magnesium Infiltration (AIMI)" process. A careful study on the reaction kinetics together with the microstructural evidence demonstrated how the MgB2 layer was formed as the infiltration process proceeded. As a result, it is possible to control the MgB2 layer growth in the AIMI-processed MgB 2 wires. The best AIMI wires, with improved density and connectivity, accomplished an outstanding layer Jc, which was 1.0 x 105 A/cm2 at 4.2 K and 10 T, nearly 10 times higher than the Jcs of PIT wires. The engineering Je of AIMI wires, namely the critical current over the whole cross-sectional area in the wire, achieved 1.7 x 104 A/cm2 at 4.2 K, 10 T, 200 % higher than those of PIT wires. Finally, two promising dopants, Dy2O3 and O, were engineered to incorporate with MgB2. Dy 2O3 nanopowders, co-doped with C in AIMI wires, enhanced the Jc performance at elevated temperatures such as 20 K. Oxygen, on the other hand, doped into MgB2 thin films through a newly-developed O2 annealing process, improved Bc2 to 14 T at 21 K. Both of the doping studies were helpful to understand the superconducting nature of MgB2.
Elevation of waterfront facade looking west. The twostory structure at ...
Elevation of waterfront facade looking west. The two-story structure at the left houses the F. & H. Benning Company Mill and is not part of the J.C. Lore Oyster House. - J.C. Lore Oyster House, 14430 Solomons Island Road, Solomons, Calvert County, MD
Elevation of south facade. The twostory structure to the right ...
Elevation of south facade. The two-story structure to the right of the J.C. Lore Oyster House houses the F. & H. Benning Company Oyster Mill, see HAER No. MD-135. - J.C. Lore Oyster House, 14430 Solomons Island Road, Solomons, Calvert County, MD
Installation Effects on Heat Transfer Measurements for a Turbine Vane
2003-03-01
turbine vanes and blades in order to acquire high accuracy, high frequency response data. Typically the installation procedure has involved either mounting...length scale such as blade chord) again matches the engine value. Also before the start of the run a choke valve downstream of the turbine is set to...of Engineering for Gas Turbines and Power (January 1984), Volume 106. p 229 - 240. Gibbings, J.C. “On boundary Layer Transition Wires.” Aeronautical
Eberhart, Charles G; Chaudhry, Aneeka; Daniel, Richard W; Khaki, Leila; Shah, Keerti V; Gravitt, Patti E
2005-01-01
Background p53 mutations are relatively uncommon in medulloblastoma, but abnormalities in this cell cycle pathway have been associated with anaplasia and worse clinical outcomes. We correlated p53 protein expression with pathological subtype and clinical outcome in 75 embryonal brain tumors. The presence of JC virus, which results in p53 protein accumulation, was also examined. Methods p53 protein levels were evaluated semi-quantitatively in 64 medulloblastomas, 3 atypical teratoid rhabdoid tumors (ATRT), and 8 supratentorial primitive neuroectodermal tumors (sPNET) using immunohistochemistry. JC viral sequences were analyzed in DNA extracted from 33 frozen medulloblastoma and PNET samples using quantitative polymerase chain reaction. Results p53 expression was detected in 18% of non-anaplastic medulloblastomas, 45% of anaplastic medulloblastomas, 67% of ATRT, and 88% of sPNET. The increased p53 immunoreactivity in anaplastic medulloblastoma, ATRT, and sPNET was statistically significant. Log rank analysis of clinical outcome revealed significantly shorter survival in patients with p53 immunopositive embryonal tumors. No JC virus was identified in the embryonal brain tumor samples, while an endogenous human retrovirus (ERV-3) was readily detected. Conclusion Immunoreactivity for p53 protein is more common in anaplastic medulloblastomas, ATRT and sPNET than in non-anaplastic tumors, and is associated with worse clinical outcomes. However, JC virus infection is not responsible for increased levels of p53 protein. PMID:15717928
Nishiyama, T; Kaneko, K; Yamada, K; Teranishi, R; Kato, T; Hirayama, T; Tobita, H; Izumi, T; Shiohara, Y
2014-11-01
IntroductionSince the discovery of REBa2Cu3O7-y (RE: Rare Earth element, REBCO) superconductors, they have been expected as the best candidates for the power cable application due to its high critical temperature (Tc) and critical current density (Jc). Among those REBCO superconductors, GdBa2Cu3O7-y (GdBCO) have been receiving great interest because they have higher Tc and Jc than YBa2Cu3O7-y [1].GdBCO with various types of precipitates as artificial pinning centers (APCs) have been proposed to minimize the anisotropy of Jc characteristics under the magnetic field. Among those precipitates, BaHfO3 (BHO) was found most effective precipitates as APCs in GdBCO film prepared by pulsed laser deposition (PLD) method [2]. It is therefore necessary to investigate not only the morphologies but also the dispersion of BHO precipitates within the GdBCO, to understand the role of BHO for the superconducting characteristics. In this study, morphologies and dispersions of BHO precipitates were characterized three-dimensional by scanning transmission electron tomography ExperimentalBHO dispersed GdBCO films were fabricated on Hastelloy C-276TM substrates with buffer layers of CeO2/LaMnO3/MgO/ Gd2ZrO7 by PLD method.To observe microstructure of GdBCO film with BHO precipitates, cross-section TEM specimens were prepared by FIB method using Quanta 3D-200 (FEI, USA) with acceleration voltage from 2 to 30 kV. Three-dimensional information such as morphology and dispersion, of BHO precipitates were characterized by electron tomography using STEM-HAADF. Result and discussionFigure 1 shows three-dimensional reconstructed volume of BHO precipitates in GdBCO, which revealed that fine BHO precipitates have rod- and plate-like morphologies with homogeneous dispersion in GdBCO. In addition, growth directions of these precipitates were found with wide angular distributions from growth direction of GdBCO. Anisotropy of Jc in the magnetic fields was probably enhanced by various growth directions and homogeneous dispersion of nanosized BHO within GdBCO.jmicro;63/suppl_1/i26/DFU080F1F1DFU080F1Fig. 1.Three-dimensional reconstructed volume of BHO. © The Author 2014. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
ERIC Educational Resources Information Center
Swank, Jacqueline M.; Gagnon, Joseph C.
2017-01-01
Background: Mental health screening and assessment is crucial within juvenile correctional facilities (JC). However, limited information is available about the current screening and assessment procedures specifically within JC. Objective: The purpose of the current study was to obtain information about the mental health screening and assessment…
Current Juvenile Corrections Professional Development Practices and Future Directions
ERIC Educational Resources Information Center
Gagnon, Joseph C.; Houchins, David E.; Murphy, Kristin M.
2012-01-01
Personnel in juvenile corrections (JC) work with students who have challenging academic, behavioral, and mental health needs. The complexity of the JC setting requires personnel to be highly skilled in effective practices to meet the demands of their job. Unfortunately, juvenile correctional personnel are neglected as an important link in the…
Performance of Microbial Concrete Developed Using Bacillus Subtilus JC3
NASA Astrophysics Data System (ADS)
Rao, M. V. Seshagiri; Reddy, V. Srinivasa; Sasikala, Ch.
2017-12-01
Concrete is vulnerable to deterioration, corrosion, and cracks, and the consequent damage and loss of strength requires immensely expensive remediation and repair. So need for special concrete that they would respond to crack formation with an autonomous self-healing action lead to research and development of microbial concrete. The microbial concrete works on the principle of calcite mineral precipitation by a specific group of alkali-resistant spore-forming bacteria related to the genus Bacillus called Bacillus subtilis JC3, this phenomenon is called biomineralization or Microbiologically Induced Calcite Crystal Precipitation. Bacillus subtilis JC3, a common soil bacterium, has inherent ability to precipitate calcite crystals continuously which enhances the strength and durability performance of concrete enormously. This microbial concrete can be called as a "Self healing Bacterial Concrete" because it can remediate its cracks by itself without any human intervention and would make the concrete more durable and sustainable. This paper discuss the incorporation of microorganism Bacillus subtilis JC3 (developed at JNTU, India) into concrete and presents the results of experimental investigations carried out to study the improved durability and sustainability characteristics of microbial concrete.
Manipulation of Auxin Response Factor 19 affects seed size in the woody perennial Jatropha curcas
Sun, Yanwei; Wang, Chunming; Wang, Ning; Jiang, Xiyuan; Mao, Huizhu; Zhu, Changxiang; Wen, Fujiang; Wang, Xianghua; Lu, Zhijun; Yue, Genhua; Xu, Zengfu; Ye, Jian
2017-01-01
Seed size is a major determinant of seed yield but few is known about the genetics controlling of seed size in plants. Phytohormones cytokinin and brassinosteroid were known to be involved in the regulation of herbaceous plant seed development. Here we identified a homolog of Auxin Response Factor 19 (JcARF19) from a woody plant Jatropha curcas and genetically demonstrated its functions in controlling seed size and seed yield. Through Virus Induced Gene Silencing (VIGS), we found that JcARF19 was a positive upstream modulator in auxin signaling and may control plant organ size in J. curcas. Importantly, transgenic overexpression of JcARF19 significantly increased seed size and seed yield in plants Arabidopsis thaliana and J. curcas, indicating the importance of auxin pathway in seed yield controlling in dicot plants. Transcripts analysis indicated that ectopic expression of JcARF19 in J. curcas upregulated auxin responsive genes encoding essential regulators in cell differentiation and cytoskeletal dynamics of seed development. Our data suggested the potential of improving seed traits by precisely engineering auxin signaling in woody perennial plants. PMID:28102350
Liu, Guan-xin; Liao, Ning
2016-01-01
To observe the clinical efficacy of Jiakangling Capsule (JC) combined with reduction of 1311 in treatment of Graves hyperthyroidism. Totally 387 Graves hyperthyroidism patients were randomly assigned to the treatment group (200 cases) and the control group (187 cases). Patients in the treatment group took JC combined with reduction of 131I. The 131I dosage per gram of thyroid tissue was 50-80 microCi. They additionally took JC one week after taking 1311 for one consecutive month. Patients in the control group took 131 routinely as one disposable treatment. The 131I dosage per gram of thyroid tissue was 70-120 microCi, without using JC or other anti-thyroid drugs. All patients were reexamined after 24-month treatment. Whether hyperthyroidism was cured, incurred, or permanent was observed. Efficacies of thyroglobulin antibody (TGAb) and thyroid microsome antibody (TMAb) were compared between the two groups. Compared with the control group, the incurred ratio increased in the treatment group [3.2% (6/187) vs. 16.0% (32/200), P < 0.01], the incurred ratio of strong positive TGAb and TMAb patients increased [3.5% (2/57) vs. 27.1% (16/59), P < 0.01], the permanent hypothyroidism ratio decreased [21.1% (12/57) vs. 3.4% (2/59), P < 0.05 ]. JC combined with reduction of 1311 was superior in treating Graves hyperthyroidism induced permanent hypothyroidism than routine 1311 treatment, especially for strong positive TGAb and TMAb patients.
Vieira, Carlos Eduardo Delfino; Costa, Patrícia Gomes; Lunardelli, Bruna; de Oliveira, Luciana Fernandes; Cabrera, Liziara da Costa; Risso, Wagner Ezequiel; Primel, Ednei Gilberto; Meletti, Paulo César; Fillmann, Gilberto; Martinez, Claudia Bueno dos Reis
2016-01-15
In order to assess the quality of streams susceptible to contamination by pesticides we apply biochemical and genotoxic biomarkers in the Neotropical fish Prochilodus lineatus submitted to in situ tests. Fish were caged, for 96 h, in two streams located in areas with intensive use of pesticides, the Apertados (AP) and the Jacutinga (JC), and in a small stream (Godoy stream — GD) found inside a forest fragment adjacent to a State Park. Biochemical parameters, such as biotransformation enzymes 7-ethoxyresorufin-O-deethylase (EROD) and glutathione-S-transferase (GST), non-protein thiols (NPSH), lipoperoxidation (LPO), protein carbonylation (PCO) and acetylcholinesterase (AChE) were evaluated in various fish organs, as well as genotoxic biomarkers (damage to DNA and occurrence of micronuclei and erythrocyte nuclear abnormalities). Samples of water and sediment were collected for analysis of metals (Cu, Cr, Pb, Ni, Mn, Cd and Zn), organochloride pesticides, and triazine and glyphosate herbicides. We observed an increase in liver GST activity in fish at AP and gill GST activity in fish at JC. An increase in liver LPO was also observed in fish exposed to AP and JC. The same animals also exhibited increased DNA damage and erythrocyte nuclear abnormalities (ENAs) compared to the fish kept in GD. A number of compounds showed concentrations higher than the permitted levels, in particular, dichlorodiphenyltrichloroethane (DDT), its metabolites dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD), hexachlorocyclohexanes (HCH), heptachloride, diclofluanid and aldrins. These pesticides were detected at higher concentrations in water and sediment samples from AP, followed by JC and GD. The Integrated Biomarker Response Index (IBR) indicated that AP and JC (AP: 21.7 > JC: 18.5 > GD: 12.6) have the worst environmental quality. Integrated biomarker analysis revealed that the alterations observed related well with the levels of environmental contaminants, demonstrating the effectiveness of this biomonitoring approach.
Murota, Yoshitaka; Tabu, Kouichi; Taga, Tetsuya
2016-11-04
Elucidating the precise properties of cancer stem cells (CSCs) is indispensable for the development of effective therapies against tumors, because CSCs are key drivers of tumor development, metastasis and relapse. We previously reported that the Hoechst 33342 dye-low staining side population (SP) method can enrich for CSCs in the C6 glioma cell line, and that the positively stained main population (MP) cells are non-CSCs. Presence of cancer stem-like SP cells is reported in various types of cancer. Although altered cellular energy metabolism is a hallmark of cancer, very little has been studied on the applicability of fluorescent probes for the understanding of CSC energy metabolism. The metabolic status of C6 SP and MP cells are evaluated by CellROX, MitoTracker Green (MTG) and JC-1 for cellular oxidative stress, mitochondrial amount, and mitochondrial membrane potential, respectively. SP cells were found to exhibit significantly lower fluorescent intensities of CellROX and MTG than MP cells. However, inhibition of ATP binding cassette (ABC) transporters by verapamil enhanced the intensities of these probes in SP cells to the levels similar to those in MP cells, indicating that SP cells expel the probes outside of the cells through ABC transporters. Next, SP cells were stained with JC-1 dye which exhibits membrane potential dependent accumulation in mitochondrial matrix, followed by formation of aggregates. The mitochondrial membrane potential indicated by the aggregates of JC-1 was 5.0-fold lower in SP cells than MP cells. Inhibition of ABC transporters enhanced the fluorescent intensities of the JC-1 aggregates in both SP and MP cells, the former of which was still 2.2-fold lower than the latter. This higher JC-1 signal in MP cells was further found to be due to the Hoechst 33342 dye existing in MP cells. When SP and MP cells were recultured to deprive the intracellular Hoechst 33342 dye and then stained with JC-1 in the presence of verapamil, the intensities of JC-1 aggregates in such SP and MP cells became comparable. Inhibiting ABC transporters and depriving Hoechst 33342 dye are required for the accurate assessment of side population-defined C6 glioma stem cell metabolism using fluorescent probes.
Authigenic Uranium in Eastern Equatorial Pacific Sediments
NASA Astrophysics Data System (ADS)
Marcantonio, F.; Lyle, M. W.; Loveley, M. R.; Ibrahim, R.
2014-12-01
Authigenic U concentrations have been used as an indicator of redox state in marine sediments. Soluble U(VI) in porewaters is reduced to insoluble U(IV) under suboxic conditions setting up a diffusion gradient through which U in bottom waters is supplied to reducing sediments. Researchers have used sedimentary redox enrichment of U as a tool to identify past redox changes, which may be caused by changes in organic carbon rain rates and/or bottom water oxygen levels. Differentiating between these two explanations is important, as the former is tied to the use of authigenic U as a paleoproductivity proxy. We examined sediments from 4 sediment cores retrieved from two different localities in the Panama Basin in the eastern equatorial Pacific. Two cores were retrieved from the northern Panama basin at the Cocos Ridge, (4JC at 5° 44.7'N 85° 45.5' W, 1730 m depth; 8JC at 6° 14.0'N 86° 2.6' W, 1993 m depth), and two were retrieved from the south at the Carnegie Ridge, (11JC at 0° 41.6'S 85° 20.0' W, 2452 m depth; 17JC at 0° 10.8'S 85° 52.0' W, 2846 m depth). Using 230Th systematics and seismic profiling at each of the sites, we've identified significant sediment winnowing (4JC and 11JC) and focusing (8JC and 17JC). At all sites, we believe that changes in age-model-derived sand (i.e., >63µm) mass accumulation rates (MAR) best represent changes in rain rates. Glacial rain rates are higher than those in the Holocene by a factor of 2-3 at both sites. Peak Mn levels (>1%), the brown-to-green color transition (which likely represents the oxic/post-oxic boundary), and peak U concentrations all appear in the same order with increasing depth down core. At the Carnegie sites, where MARs are greater than those at the Cocos sites, increases in authigenic U (up to 4 ppm) occur during the mid- to late Holocene at depths of 10-15 cm. At the Cocos sites, increases in authigenic U (up to 12 ppm) occur lower in the sediment column (25-30 cm) during the late glacial. The decrease in sediment MAR (and, likely, productivity) between the last glacial and the Holocene has most likely driven the syndiagenetic enrichment of U at these sites by diffusion of bottom water U to slightly beyond the oxic/post-oxic boundary. Hence, changing bottom water oxygen levels are not a requirement to explain authigenic U concentrations in eastern equatorial Pacific sediments.
NASA Astrophysics Data System (ADS)
Clem, John R.
2011-06-01
I introduce a critical-state theory incorporating both flux cutting and flux transport to calculate the magnetic-field and current-density distributions inside a type-II superconducting cylinder at its critical current in a longitudinal applied magnetic field. The theory is an extension of the elliptic critical-state model introduced by Romero-Salazar and Pérez-Rodríguez. The vortex dynamics depend in detail on two nonlinear effective resistivities for flux cutting (ρ∥) and flux flow (ρ⊥), and their ratio r=ρ∥/ρ⊥. When r<1, the low relative efficiency of flux cutting in reducing the magnitude of the internal magnetic-flux density leads to a paramagnetic longitudinal magnetic moment. As a model for understanding the experimentally observed interrelationship between the critical currents for flux cutting and depinning, I calculate the forces on a helical vortex arc stretched between two pinning centers when the vortex is subjected to a current density of arbitrary angle ϕ. Simultaneous initiation of flux cutting and flux transport occurs at the critical current density Jc(ϕ) that makes the vortex arc unstable.
ERIC Educational Resources Information Center
McDonnell, Janice D.
The Jacques Cousteau National Estuarine Research Reserve (JC NERR) program has successfully capitalized on human fascination with the ocean by using the marine environment to develop interest and capability in science. The Institute of Marine & Coastal Sciences, as the managing agency of the JC NERR, makes its faculty, staff resources, and…
REPRODUCTIVE EFFECTS OF THE WATER DISINFECTANT BYPRODUCT BROMOCHLOROACETIC ACID (BCA) IN ADULT AND JUVENILE MALE C57BL/6 MICE.
JC Rockett, JC Luft, JB Garges and DJ Dix. Reproductive Toxicology Division, USEPA, RTP, NC, USA.
Sponsor: G Klinefelter
The development of wate...
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2011-11-14
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Implementation of ERDC HEP Geo-Material Model in CTH and Application
2011-11-02
used TARDEC JWL inputs for C4 and Johnson- Cook Strength inputs TARDEC JC fracture model inputs for 5083 plate changed due to problems seen in...fracture inputs from IMD tests - LS-DYNA C4 JWL and Johnson-Cook strength inputs used in CTH runs - Results indicate that TARDEC JC fracture model
Ye, Liyang; Cruciani, Davide; Xu, Minfeng; Mine, Susumu; Amm, Kathleen; Schwartz, Justin
2015-01-01
Long lengths of metal/MgB2 composite conductors with high critical current density (Jc), fabricated by the power-in-tube (PIT) process, have recently become commercially available. Owing to its electromagnetic performance in the 20 K – 30 K range and relatively low cost, MgB2 may be attractive for a variety of applications. One of the key issues for magnet design is stability and quench protection, so the behavior of MgB2 wires and magnets must be understood before large systems can emerge. In this work, the stability and quench behavior of several conduction-cooled MgB2 wires are studied. Measurements of the minimum quench energy and normal zone propagation velocity are performed on short samples in a background magnetic field up to 3 T and on coils in self-field and the results are explained in terms of variations in the conductor architecture, electrical transport behavior, operating conditions (transport current and background magnetic field) and experimental setup (short sample vs small coil). Furthermore, one coil is quenched repeatedly with increasing hot-spot temperature until Jc is decreased. It is found that degradation during quenching correlates directly with temperature and not with peak voltage; a safe operating temperature limit of 260 K at the surface is identified. PMID:25883414
Intrinsic and extrinsic pinning in NdFeAs(O,F): vortex trapping and lock-in by the layered structure
NASA Astrophysics Data System (ADS)
Tarantini, C.; Iida, K.; Hänisch, J.; Kurth, F.; Jaroszynski, J.; Sumiya, N.; Chihara, M.; Hatano, T.; Ikuta, H.; Schmidt, S.; Seidel, P.; Holzapfel, B.; Larbalestier, D. C.
2016-10-01
Fe-based superconductors (FBS) present a large variety of compounds whose properties are affected to different extents by their crystal structures. Amongst them, the REFeAs(O,F) (RE1111, RE being a rare-earth element) is the family with the highest critical temperature Tc but also with a large anisotropy and Josephson vortices as demonstrated in the flux-flow regime in Sm1111 (Tc ∼ 55 K). Here we focus on the pinning properties of the lower-Tc Nd1111 in the flux-creep regime. We demonstrate that for H//c critical current density Jc at high temperatures is dominated by point-defect pinning centres, whereas at low temperatures surface pinning by planar defects parallel to the c-axis and vortex shearing prevail. When the field approaches the ab-planes, two different regimes are observed at low temperatures as a consequence of the transition between 3D Abrikosov and 2D Josephson vortices: one is determined by the formation of a vortex-staircase structure and one by lock-in of vortices parallel to the layers. This is the first study on FBS showing this behaviour in the full temperature, field, and angular range and demonstrating that, despite the lower Tc and anisotropy of Nd1111 with respect to Sm1111, this compound is substantially affected by intrinsic pinning generating a strong ab-peak in Jc.
NASA Astrophysics Data System (ADS)
Marcantonio, F.; Loveley, M.; Wisler, M.; Hostak, R.; Hertzberg, J. E.; Schmidt, M. W.; Lyle, M. W.
2017-12-01
Storage of respired carbon in the deep ocean may play a significant role in lowering atmospheric CO2 concentrations by about 80 ppm during the last glacial maximum compared to pre-industrial times. The cause of this sequestration and the subsequent release of the deep respired carbon pool at the last termination remains elusive. Within the last glacial period, on millennial timescales, the relationship between the CO2 cycle and any waxing and waning of a deep respired pool also remains unclear. To further our understanding of the millennial variability in the storage of a deep-ocean respired carbon pool during the last glacial, we measure authigenic uranium and 230Th-derived non-lithogenic barium fluxes (xsBa flux) in two high-sedimentation-rate cores from the Panama Basin of the Eastern Equatorial Pacific (EEP) (8JC, 6° 14.0' N, 86° 02.6' W; 1993 m water depth; 17JC 00° 10.8' S, 85° 52.0' W; 2846 m water depth). Sediment authigenic U concentrations are controlled by the redox state of sediments which, in turn, is a function of the rain of organic material from the surface ocean and the oxygen content of bottom waters. At both 8JC and 17JC, the mismatch between xsBa fluxes, a proxy for the reconstruction of oceanic productivity, and authigenic uranium concentrations suggests that the primary control of the latter values is changes in bottom water oxygenation. Peak authigenic uranium concentrations occur during glacial periods MIS 2, 3, and 4, respectively, and are two to three times higher than those during interglacial periods, MIS 1 and 5. EEP bottom waters were likely suboxic during times of the last glacial period when atmospheric CO2 concentrations were at their lowest concentrations. In addition, the pattern of increased deep-water oxygenation during times of higher CO2 during the last glacial is similar to that reported in a study of authigenic U in sediments from the Antarctic Zone of the Southern Ocean (Jaccard et al., 2016). We suggest that a respired carbon pool existed within a large swath of the abyssal Southern and Pacific Oceans throughout the entire last glacial cycle, and that this respired carbon was periodically released through increased ventilation of deep ocean waters. Jaccard et al. (2016) Nature 530, 207-210.
Roseomonas hibiscisoli sp. nov., isolated from the rhizosphere of Mugunghwa (Hibiscus syriacus).
Yan, Zheng-Fei; Lin, Pei; Li, Chang-Tian; Kook, MooChang; Wang, Qi-Jun; Yi, Tae-Hoo
2017-08-01
A Gram-stain-negative, aerobic, non-motile and coccoid to short-rod-shaped bacterial strain (THG-N2.22T) was isolated from the rhizosphere of Mugunghwa (Hibiscus syriacus). Growth occurred at 20-40 °C (optimum 28 °C), at pH 5-9 (optimum 7) and with 0-4 % (w/v) NaCl (optimum 1 %). Based on 16S rRNA gene sequence analysis, the nearest phylogenetic neighbours of strain THG-N2.22T were identified as Roseomonas rhizosphaerae YW11T (98.5 % similarity), Roseomonas rubra S5T (98.5 %), Roseomonas cervicalis ATCC 49957T (98.2 %), Roseomonas aestuarii JC17T (97.8 %), Roseomonas oryzae JC288T (97.3 %) and Roseomonas ludipueritiae 170/96T (97.3 %); levels of similarity with the type strains of other Roseomonas species were lower than 97.0 %. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, two unidentified aminolipids, three unidentified phospholipids and three unidentified lipids. The major quinone was ubiquinone-10. The major fatty acids were C16 : 0, C18 : 1 2-OH, C18 : 1ω7c and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The DNA G+C content of strain THG-N2.22T was 64.1 mol%. DNA-DNA hybridization values between strain THG-N2.22T and R. rhizosphaerae YW11T, R. rubra S5T, R. cervicalis ATCC 49957T, R. aestuarii JC17T, R. oryzae JC288T and R. ludipueritiae 170/96T were 43.1 % (30.2 %, reciprocal analysis), 39.0 % (24.7 %), 34.4 % (15.2 %), 18.0 % (14.5 %), 14.7 % (9.7 %) and 11.0 % (5.6 %), respectively. On the basis of the phylogenetic analysis, chemotaxonomic data, physiological characteristics and DNA-DNA hybridization data, strain THG-N2.22T represents a novel species of the genus Roseomonas, for which the name Roseomonas hibiscisoli sp. nov. is proposed. The type strain is THG-N2.22T (=KACC 18935T=CCTCC AB 2016176T).
Gromek, Samantha M.; Suria, Andrea M.; Fullmer, Matthew S.; Garcia, Jillian L.; Gogarten, Johann Peter; Nyholm, Spencer V.; Balunas, Marcy J.
2016-01-01
Female members of many cephalopod species house a bacterial consortium in the accessory nidamental gland (ANG), part of the reproductive system. These bacteria are deposited into eggs that are then laid in the environment where they must develop unprotected from predation, pathogens, and fouling. In this study, we characterized the genome and secondary metabolite production of Leisingera sp. JC1, a member of the roseobacter clade (Rhodobacteraceae) of Alphaproteobacteria isolated from the jelly coat of eggs from the Hawaiian bobtail squid, Euprymna scolopes. Whole genome sequencing and MLSA analysis revealed that Leisingera sp. JC1 falls within a group of roseobacters associated with squid ANGs. Genome and biochemical analyses revealed the potential for and production of a number of secondary metabolites, including siderophores and acyl-homoserine lactones involved with quorum sensing. The complete biosynthetic gene cluster for the pigment indigoidine was detected in the genome and mass spectrometry confirmed the production of this compound. Furthermore, we investigated the production of indigoidine under co-culture conditions with Vibrio fischeri, the light organ symbiont of E. scolopes, and with other vibrios. Finally, both Leisingera sp. JC1 and secondary metabolite extracts of this strain had differential antimicrobial activity against a number of marine vibrios, suggesting that Leisingera sp. JC1 may play a role in host defense against other marine bacteria either in the eggs and/or ANG. These data also suggest that indigoidine may be partially, but not wholly, responsible for the antimicrobial activity of this squid-associated bacterium. PMID:27660622
Singh, Hem; Prakash, Atish; Kalia, A N; Majeed, Abu Bakar Abdul
2016-10-01
Previously explored combination therapies mostly involved the use of bioactive molecules. It is believed that herbal compounds containing multiple plant products have synergistic hepatoprotective effects and could enhance the desired actions. To investigate the combination of ethanolic fruits extract of Solanum xanthocarpum (SX) and Juniperus communis (JC) against Paracetamol (PCM) and Azithromycin (AZM) induced liver toxicity in rats. Liver toxicity was induced by combine oral administration of PCM (250 mg/kg) and AZM (200 mg/kg) for 7 days in Wistar rats. Fruit extract of SX (200 and 400 mg/kg) and JC (200 and 400 mg/kg) were administered daily for 14 days. The hepatoprotective activity was assessed using liver functional test, oxidative parameters and histopathological examination. The results demonstrated that combine administration of AZM and PCM significantly produced liver toxicity by increasing the serum level of hepatic enzymes and oxidative parameters in liver of rats. Histopathological examination also indicated that AZM and PCM produced liver damage in rats. Chronic treatment of SX and JC extract significantly and dose-dependently attenuated the liver toxicity by normalizing the biochemical factors and no gross histopathological changes were observed in liver of rats. Furthermore, combine administration of lower dose of SX and JC significantly potentiated their hepatoprotective effect which was significant as compared to their effect per se. The results clearly indicated that SX and JC extract has hepatoprotective potential against AZM and PCM induced liver toxicity due to their synergistic anti-oxidant properties.
Solar cycles and depositional processes in annual 10Be from two varved lake sediment records
NASA Astrophysics Data System (ADS)
Czymzik, Markus; Muscheler, Raimund; Brauer, Achim; Adolphi, Florian; Ott, Florian; Kienel, Ulrike; Dräger, Nadine; Słowiński, Michał; Aldahan, Ala; Possnert, Göran
2015-10-01
Beryllium 10 concentrations (10Becon) were measured at annual resolution from varved sediment cores of Lakes Tiefer See (TSK) and Czechowskie (JC) for the period 1983-2009 (∼solar cycles 22 and 23). Calibrating the 10Becon time-series against complementing proxy records from the same archive as well as local precipitation and neutron monitor data, reflecting solar forced changes in atmospheric radionuclide production, allowed (i) identifying the main depositional processes and (ii) evaluating the potential for solar activity reconstruction. 10Becon in TSK and JC sediments are significantly correlated to varying neutron monitor counts (TSK: r = 0.5, p = 0.05, n = 16; JC: r = 0.46, p = 0.03, n = 22). However, the further correlations with changes in organic carbon contents in TSK as well as varying organic carbon and detrital matter contents in JC point to catchment specific biases in the 10Becon time-series. In an attempt to correct for these biases multiple regression analysis was applied to extract an atmospheric 10Be production signal (10Beatmosphere). To increase the signal to noise ratio a 10Be composite record (10Becomposite) was calculated from the TSK and JC 10Beatmosphere time-series. 10Becomposite is significantly correlated to variations in the neutron monitor record (r = 0.49, p = 0.01, n = 25) and matches the expected amplitude changes in 10Be production between solar cycle minima and maxima. This calibration study on 10Be from two sites indicates the large potential but also, partly site-specific, limitations of 10Be in varved lake sediments for solar activity reconstruction.
Publications - Plafker, George and others, 1994 | Alaska Division of
Publications Plafker, George and others, 1994 main content USGS Plafker, George and others, 1994 Publication Details Title: Neotectonic map of Alaska Authors: Plafker, George, Gilpin, L.M., and Lahr, J.C Reference Plafker, George, Gilpin, L.M., and Lahr, J.C., 1994, Neotectonic map of Alaska, in Plafker, George
BIOSPACE/DYABOLIC October 2010 Field Program, Monterey Bay, California Data Report
2011-07-20
AU Fluorometer. After first reading samples were acidified with three drops of 5% HCl (to destroy the Chlorophyll) allowing the measurement of...DBCBLFOEB CJ BB BND-)#DBE CME JC 57$%2$0=$2B EKGE JKLMCJN DBCBLMKBN CN JJ 57$%2$0=$2C ENJE JKLMBO DBCBLMKMM JE F JO 57$%2$0=$2J EFBN JKLMEKK DBCBLMKMF JC
Mutations Allow JC Polyomaviruses to Elude Antibody Recognition | Center for Cancer Research
JC polyomavirus (JCV) infects the urinary tract of most adults. In healthy individuals, JCV infection does not cause noticeable symptoms. However, in those with compromised immune systems, JCV can cause a lethal brain disease called progressive multifocal leukoencephalopathy (PML). Data from a recently approved assay to detect serum antibodies specific for the JCV protein VP1
2007-01-01
Morris JC, Hulette C, Schmechel D, Reiman EM, Rogers J, Stephan DA. (2005). Gene expression correlates of neurofibrillary tangles in Alzheimer’s...Walker DG, Lafleur BJ, Coon KD, Brown KM, Caselli R, Kukull W, Higdon R, McKeel D, Morris JC, Hulette C, Schmechel D, Reiman EM, Rogers J, Stephan
Agarwal, Parinita; Dabi, Mitali; Sapara, Komal K; Joshi, Priyanka S; Agarwal, Pradeep K
2016-01-01
Plants, being sessile, have developed intricate signaling network to specifically respond to the diverse environmental stress. The plant-specific WRKY TFs form one of the largest TF family and are involved in diverse plant processes, involving growth, development and stress signaling through auto and cross regulation with different genes and TFs. Here, we report the functional characterization of a salicylic acid -inducible JcWRKY TF. The JcWRKY overexpression confers salinity tolerance in transgenic tobacco, as was evident by increased chlorophyll content and seed germination potential. The transgenic plants showed increased soluble sugar, membrane stability, reduced electrolyte leakage and generation of reactive oxygen species (H 2 O 2 and [Formula: see text]) as compared to the wild type. Furthermore, the low SA treatment along with salinity improved the tolerance potential of the transgenics by maintaining ROS homeostasis and high K + /Na + ratio. The transcript expression of SA biosynthetic gene ICS1 and antioxidative enzymes ( CAT and SOD ) showed upregulation during stress. Thus, the present study reflects that JcWRKY is working in co-ordination with SA signaling to orchestrate the different biochemical and molecular pathways to maneuvre salt stress tolerance of the transgenic plants.
Genome-Wide Analysis of the NAC Gene Family in Physic Nut (Jatropha curcas L.)
Wu, Zhenying; Xu, Xueqin; Xiong, Wangdan; Wu, Pingzhi; Chen, Yaping; Li, Meiru; Wu, Guojiang; Jiang, Huawu
2015-01-01
The NAC proteins (NAM, ATAF1/2 and CUC2) are plant-specific transcriptional regulators that have a conserved NAM domain in the N-terminus. They are involved in various biological processes, including both biotic and abiotic stress responses. In the present study, a total of 100 NAC genes (JcNAC) were identified in physic nut (Jatropha curcas L.). Based on phylogenetic analysis and gene structures, 83 JcNAC genes were classified as members of, or proposed to be diverged from, 39 previously predicted orthologous groups (OGs) of NAC sequences. Physic nut has a single intron-containing NAC gene subfamily that has been lost in many plants. The JcNAC genes are non-randomly distributed across the 11 linkage groups of the physic nut genome, and appear to be preferentially retained duplicates that arose from both ancient and recent duplication events. Digital gene expression analysis indicates that some of the JcNAC genes have tissue-specific expression profiles (e.g. in leaves, roots, stem cortex or seeds), and 29 genes differentially respond to abiotic stresses (drought, salinity, phosphorus deficiency and nitrogen deficiency). Our results will be helpful for further functional analysis of the NAC genes in physic nut. PMID:26125188
Genome-Wide Analysis of the NAC Gene Family in Physic Nut (Jatropha curcas L.).
Wu, Zhenying; Xu, Xueqin; Xiong, Wangdan; Wu, Pingzhi; Chen, Yaping; Li, Meiru; Wu, Guojiang; Jiang, Huawu
2015-01-01
The NAC proteins (NAM, ATAF1/2 and CUC2) are plant-specific transcriptional regulators that have a conserved NAM domain in the N-terminus. They are involved in various biological processes, including both biotic and abiotic stress responses. In the present study, a total of 100 NAC genes (JcNAC) were identified in physic nut (Jatropha curcas L.). Based on phylogenetic analysis and gene structures, 83 JcNAC genes were classified as members of, or proposed to be diverged from, 39 previously predicted orthologous groups (OGs) of NAC sequences. Physic nut has a single intron-containing NAC gene subfamily that has been lost in many plants. The JcNAC genes are non-randomly distributed across the 11 linkage groups of the physic nut genome, and appear to be preferentially retained duplicates that arose from both ancient and recent duplication events. Digital gene expression analysis indicates that some of the JcNAC genes have tissue-specific expression profiles (e.g. in leaves, roots, stem cortex or seeds), and 29 genes differentially respond to abiotic stresses (drought, salinity, phosphorus deficiency and nitrogen deficiency). Our results will be helpful for further functional analysis of the NAC genes in physic nut.
Design versions of HTS three-phase cables with the minimized value of AC losses
NASA Astrophysics Data System (ADS)
Altov, V. A.; Balashov, N. N.; Degtyarenko, P. N.; Ivanov, S. S.; Kopylov, S. I.; Lipa, DA; Samoilenkov, S. V.; Sytnikov, V. E.; Zheltov, V. V.
2018-03-01
Design versions of HTS three-phase cables consisting of 2G HTS tapes have been investigated by the numerical simulation method with the aim of AC losses minimization. Two design versions of cables with the coaxial and extended rectangular cross-section shape are considered – the non-sectioned and sectioned one. In the latter each cable phase consists of sections connected in parallel. The optimal dimensions of sections and order of their alteration are chosen by appropriate calculations. The model used takes into account the current distribution between the sections and its non-uniformity within each single HTS tape as well. The following characteristics are varied: design version, dimension, positioning of extra copper layer in a cable, design of HTS tapes themselves and their mutual position. The dependence of AC losses on the latter two characteristics is considered in details, and the examples of cable designs optimized by the total set of characteristics for the medium class of voltages (10 – 60 kV) are given. At the critical current JC=5.1 кA per phase and current amplitudes lower than 0.85JC, the level of total AC losses does not exceed the natural cryostat heat losses.
Composite ceramic superconducting wires for electric motor applications
NASA Astrophysics Data System (ADS)
Halloran, John W.
1990-04-01
Silver clad polycrystalline Y-123 wire is being fabricated with a continuous reel-to-reel process. Scale-up activities are underway to produce enough wire for the field coils of the HTSC motor. Green HTSC fiber were produced in kilometer lengths, and sintered wires up to 166 meters long. The 77K Jc values are 1000-2800 A/sq cm in self field. To improve Jc of the Y-123 wire, development began on directional crystallization, including preliminary work at A. D. Little and Oak Ridge National Lab. Large lots of BiSCCO material were produced to fabricated fibers and sintered polycrystalline BiSSCO wire as rolled tape. Work continued in collaboration with Sandia and Los Alamos National Laboratories on rapid thermal processing of Y-123, with most emphasis on characterizing the rapid oxygenation effect. The design of the HTSC homopolar motor has been improved to increase the output from field coils by using six smaller coils, each with separately optimized current. Motor construction is in progress. Preliminary design is underway on a dc heteropolar motor with HTSC field windings and armature and a brushless trapped flux permanent magnet dc motor, in which the field is produced by trapped flux in an HTSC rotor.
Analysis and Algorithms for Imperfect Sensor Deployment and Operations
2016-05-23
fortification-interdiction-routing games that take place over the traveling salesman problem (TSP) in reference 16. This study reveals that a straightforward...Journal on Optimization. 16. Lozano, L., Smith, J.C., and Kurz, M.E., Solving the Traveling Salesman Problem with Interdiction and Fortification...the Traveling Salesman Problem with Interdiction and Fortification, submitted to Operations Research Letters. Tadayon, B. and Smith, J.C., A Survey of
2006-12-01
hypothesis testing (ANOVA) using icrosoft Excel v10.0 atα= 0.05 significance threshold. Fol- owing ANOVA, Fisher’s least significant difference, LSD , air...critical value (α= 0.05) ound in the t distribution. If the average absolute difference etween any two groups was greater than the LSD critical alue...cIntyre, T.M., Pontsler, A.V., Silva, A.R., St Hilaire, A., Xu, Y., Hin- shaw , J.C., Zimmerman, G.A., Hama, K., Aoki, J., Arai, H., Prestwich, G.D
NASA Astrophysics Data System (ADS)
Takahashi, K.; Kobayashi, H.; Yamada, Y.; Ibi, A.; Fukushima, H.; Konishi, M.; Miyata, S.; Shiohara, Y.; Kato, T.; Hirayama, T.
2006-09-01
In order to increase the critical current, Ic, we have fabricated thick GdBa2Cu3O7-δ (GdBCO) coated conductors (CCs) by the pulsed laser deposition (PLD) method on PLD-CeO2/ion-beam assisted deposition (IBAD)-Gd2Zr2O7 (GZO)/hastelloy metal substrate tapes. The highest critical current value was 522 A cm-1 for a thickness of 3.6 µm in self-field at 77 K. It was found that a low volume fraction of a-axis orientated grains was obtained in the thick GdBCO CCs, compared to YBa2Cu3O7-δ (YBCO) CCs. Consequently, the GdBCO CCs showed higher critical current density (Jc) than YBCO CCs in all thicknesses from 0.2 to 3.6 µm. Furthermore, we have succeeded in improving Ic in a magnetic field by the introduction of artificial pinning centres using a 5 mol% ZrO2 doped GdBCO target. In the measurement of the Ic dependence on the magnetic field angle, θ, Ic was much improved, especially at 0°, i.e., with the magnetic field parallel to the c-axis. The Ic value at 3 T was 59.5 A cm-1 at 0° and it showed a minimum of 42.3 A cm-1 at 82° for 2.28 µm thick CC. The minimum value in the angular dependence of Ic at 3 T was about five times higher than that of YBCO CC and two times higher than that of pure GdBCO CC.
Man, Shumei; Cox, Margueritte; Patel, Puja; Smith, Eric E; Reeves, Mathew J; Saver, Jeffrey L; Bhatt, Deepak L; Xian, Ying; Schwamm, Lee H; Fonarow, Gregg C
2017-02-01
Primary stroke center (PSC) certification was established to identify hospitals providing evidence-based care for stroke patients. The numbers of PSCs certified by Joint Commission (JC), Healthcare Facilities Accreditation Program, Det Norske Veritas, and State-based agencies have significantly increased in the past decade. This study aimed to evaluate whether PSCs certified by different organizations have similar quality of care and in-hospital outcomes. The study population consisted of acute ischemic stroke patients who were admitted to PSCs participating in Get With The Guidelines-Stroke between January 1, 2010, and December 31, 2012. Measures of care quality and outcomes were compared among the 4 different PSC certifications. A total of 477 297 acute ischemic stroke admissions were identified from 977 certified PSCs (73.8% JC, 3.7% Det Norske Veritas, 1.2% Healthcare Facilities Accreditation Program, and 21.3% State-based). Composite care quality was generally similar among the 4 groups of hospitals, although State-based PSCs underperformed JC PSCs in a few key measures, including intravenous tissue-type plasminogen activator use. The rates of tissue-type plasminogen activator use were higher in JC and Det Norske Veritas (9.0% and 9.8%) and lower in State and Healthcare Facilities Accreditation Program certified hospitals (7.1% and 5.9%) (P<0.0001). Door-to-needle times were significantly longer in Healthcare Facilities Accreditation Program hospitals. State PSCs had higher in-hospital risk-adjusted mortality (odds ratio 1.23, 95% confidence intervals 1.07-1.41) compared with JC PSCs. Among Get With The Guidelines-Stroke hospitals with PSC certification, acute ischemic stroke quality of care and outcomes may differ according to which organization provided certification. These findings may have important implications for further improving systems of care. © 2016 American Heart Association, Inc.
Soares, A M S; Carvalho, L P; Melo, E J T; Costa, H P S; Vasconcelos, I M; Oliveira, J T A
2015-06-01
Toxoplasma gondii is a parasite of great medical and veterinary importance that has worldwide distribution and causes toxoplasmosis. There are few treatments available for toxoplasmosis and the search for plant extracts and compounds with anti-Toxoplasma activity is of utmost importance for the discovery of new active drugs. The objective of this study was to investigate the action of a protein extract and a protease inhibitor enriched fraction from J. curcas seed cake on developing tachyzoites of T. gondii-infected Vero cells. The protein extract (JcCE) was obtained after solubilization of the J. curcas seed cake with 100 mM sodium borate buffer, pH 10, centrifugation and dialysis of the resulting supernatant with the extracting buffer. JcCE was used for the in vitro assays of anti-Toxoplasma activity at 0.01, 0.1, 0.5, 1.5, 3.0 and 5.0 mg/ml concentration for 24 h. The results showed that JcCE reduced the percentage of infection and the number of intracellular parasites, but had no effect on the morphology of Vero cells up to 3.0 mg/mL. The cysteine protease inhibitor enriched fraction, which was obtained after chromatography of JcCE on Sephadex G-75 and presented a unique protein band following SDS-PAGE, reduced both the number of T. gondii infected cells and intracellular parasites. These results suggest that both JcCE and the cysteine protease inhibitor enriched fraction interfere with the intracellular growth of T. gondii. Copyright © 2015 Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Heusser, L. E.; Hendy, I. L.
2015-12-01
The Younger Dryas is a well-known rapid climatic cooling that interrupted the Marine Isotope Stage (MIS) 1-2 deglacial warming of Termination 1. This cool event has been associated with ice sheet readvance, meridional overturning, circulation changes, and southward movement of the Intertropical Convergence Zone. In Southern California, the Younger Dryas has been associated with cooler SST, low marine productivity, a well-ventilated oxygen minimum zone, and a wetter climate. Similar rapid cooling events have been found at other terminations including Termination 5 at the MIS 11-12 deglaciation (~425 Ka) identified by ice rafting events in the North Atlantic. Here we present new pollen census data from a unique suite of cores taken from the sub-oxic sediments of Santa Barbara Basin (MV0508-15JC, MV0805-20JC, MV0508-33JC, 29JC and 21JC). These short cores, collected on a truncated anticline within SBB, provide the opportunity to examine the response of southern California terrestrial and marine ecosystems to rapid climate change during the MIS 11-12 deglaciation (Termination 5), which is identified by a bioturbated interval within a sequence of laminated sediments. During Termination 1, changes in Southern California precipitation are reflected in pollen- based reconstructions Southern California vegetation. The high precipitation of glacial montane-coniferous assemblages of pine (Pinus) and Juniper (Juniperus/Calocedrus) transitions into interglacial drought, as expresssed by arid oak (Quercus)/chaparral vegetation. The Younger Dryas interrupts the transition as a high-amplitude pulse in pine associated with increased Gramineae (grass). Termination 5 differs, as the high precipitation of glacial montane-coniferous assemblages do not transition into arid oak/chaparral vegetation. However, a Younger Dryas-like rapid climate event was associated with increased pine and grass.
Full control of the spin-wave damping in a magnetic insulator using spin orbit torque
NASA Astrophysics Data System (ADS)
Klein, Olivier
2015-03-01
The spin-orbit interaction (SOI) has been an interesting and useful addition in the field of spintronics by opening it to non-metallic magnet. It capitalizes on adjoining a strong SOI normal metal next to a thin magnetic layer. The SOI converts a charge current, Jc, into a spin current, Js, with an efficiency parametrized by ΘSH, the spin Hall angle. An important benefit of the SOI is that Jc and Js are linked through a cross-product, allowing a charge current flowing in-plane to produce a spin current flowing out-of-plane. Hence it enables the transfer of spin angular momentum to non-metallic materials and in particular to insulating oxides, which offer improved performance compared to their metallic counterparts. Among all oxides, Yttrium Iron Garnet (YIG) holds a special place for having the lowest known spin-wave (SW) damping factor. Until recently the transmission of spin current through the YIG|Pt interface has been subject to debate. While numerous experiments have reported that Js produced by the excitation of ferromagnetic resonance (FMR) in YIG can cross efficiently the YIG|Pt interface and be converted into Jc in Pt through the inverse spin Hall effect (ISHE), most attempts to observe the reciprocal effect, where Js produced in Pt by the direct spin Hall effect (SHE) is transferred to YIG, resulting in damping compensation, have failed. This has been raising fundamental questions about the reciprocity of the spin transparency of the interface between a metal and a magnetic insulator. In this talk it will be demonstrated that the threshold current for damping compensation can be reached in a 5 μm diameter YIG(20nm)|Pt(7nm) disk. Reduction of both the thickness and lateral size of a YIG-structure were key to reach the microwave generation threshold current, Jc*. The experimental evidence rests upon the measurement of the ferromagnetic resonance linewidth as a function of Idc using a magnetic resonance force microscope (MRFM). It is shwon that the magnetic losses of spin-wave modes existing in the magnetic insulator can be reduced or enhanced by at least a factor of five depending on the polarity and intensity of the in-plane dc current, Idc. Complete compensation of the damping of the fundamental mode by spin-orbit torque is reached for a current density of ~ 3 .1011 A.m-2, in agreement with theoretical predictions. At this critical threshold the MRFM detects a small change of static magnetization, a behavior consistent with the onset of an auto-oscillation regime. This result opens up a new area of research on the electronic control of the damping of YIG-nanostructures.
Broad Temperature Pinning Study of 15 mol.% Zr-Added (Gd, Y)-Ba-Cu-O MOCVD Coated Conductors
DOE Office of Scientific and Technical Information (OSTI.GOV)
Xu, AX; Khatri, N; Liu, YH
BaZrO3 (BZO) nanocolumns have long been shown to be very effective for raising the pinning force F-p of REBa2Cu3Ox (REBCO, where RE = rare earth) films at high temperatures and recently at low temperatures too. We have successfully incorporated a high density of BZO nanorods into metal organic chemical vapor deposited (MOCVD) REBCO coated conductors via Zr addition. We found that, compared to the 7.5% Zr-added coated conductor, dense BZO nanorod arrays in the 15% Zr-added conductor are effective over the whole temperature range from 77 K down to 4.2 K. We attribute the substantially enhanced J(c) at 30 Kmore » to the weak uncorrelated pinning as well as the strong correlated pinning. Meanwhile, by tripling the REBCO layer thickness to similar to 2.8 mu m, the engineering critical current density J(e) at 30 K exceeds J(e) of optimized Nb-Ti wires at 4.2 K.« less
2014-06-01
from the ODM standard. Leveraging SPARX EA’s Java application programming interface (API), the team built a tool called OWL2EA that can ingest an OWL...server MySQL creates the physical schema that enables a user to store and retrieve data conforming to the vocabulary of the JC3IEDM. 6. GENERATING AN
Susceptibility of superconductor disks and rings with and without flux creep
NASA Astrophysics Data System (ADS)
Brandt, Ernst Helmut
1997-06-01
First some consequences of the Bean assumption of constant critical current Jc in type-II superconductors are listed and the Bean ac susceptibility of narrow rings is derived. Then flux creep is described by a nonlinear current-voltage law E~Jn, from which the saturated magnetic moment at constant ramp rate H-|Apa(t) is derived for rings with general hole radius a1 and general creep exponent n. Next the exact formulation for rings in a perpendicular applied field Ha(t) is presented in the form of an equation of motion for the current density in thick rings and disks or the sheet current in thin rings and disks. This method is used to compute general magnetization curves m(Ha) and ac susceptibilities χ of rings with and without creep, accounting also for nonconstant Jc(B). Typical current and field (B) profiles are depicted. The initial slope of m(Ha) (the ideal diamagnetic moment) and the field of full penetration are expressed as functions of the inner and outer ring radii a1 and a. A scaling law is derived which states that for arbitrary creep exponent n the complex nonlinear ac susceptibility χ(H0,ω) depends only on the combination Hn-10/ω of the ac amplitude H0 and the ac frequency ω/2π. This scaling law thus connects the known dependencies χ=χ(ω) in the ohmic limit (n=1) and χ=χ(H0) in the Bean limit (n-->∞).
2012-04-22
... r>jc M CM O il 1 *|I » - I JC ES I •; ^ £ 1 » _c — e :/: JI — V — K >,* «• E 5 - ... I E I| g. o * —.^ n a: x: (X*. z cr 5. ^^ u .£•"• es 'n lc re fL £. £. o; oe ai te. a: Z ...
Flipped classroom model for learning evidence-based medicine.
Rucker, Sydney Y; Ozdogan, Zulfukar; Al Achkar, Morhaf
2017-01-01
Journal club (JC), as a pedagogical strategy, has long been used in graduate medical education (GME). As evidence-based medicine (EBM) becomes a mainstay in GME, traditional models of JC present a number of insufficiencies and call for novel models of instruction. A flipped classroom model appears to be an ideal strategy to meet the demands to connect evidence to practice while creating engaged, culturally competent, and technologically literate physicians. In this article, we describe a novel model of flipped classroom in JC. We present the flow of learning activities during the online and face-to-face instruction, and then we highlight specific considerations for implementing a flipped classroom model. We show that implementing a flipped classroom model to teach EBM in a residency program not only is possible but also may constitute improved learning opportunity for residents. Follow-up work is needed to evaluate the effectiveness of this model on both learning and clinical practice.
Flipped classroom model for learning evidence-based medicine
Rucker, Sydney Y; Ozdogan, Zulfukar; Al Achkar, Morhaf
2017-01-01
Journal club (JC), as a pedagogical strategy, has long been used in graduate medical education (GME). As evidence-based medicine (EBM) becomes a mainstay in GME, traditional models of JC present a number of insufficiencies and call for novel models of instruction. A flipped classroom model appears to be an ideal strategy to meet the demands to connect evidence to practice while creating engaged, culturally competent, and technologically literate physicians. In this article, we describe a novel model of flipped classroom in JC. We present the flow of learning activities during the online and face-to-face instruction, and then we highlight specific considerations for implementing a flipped classroom model. We show that implementing a flipped classroom model to teach EBM in a residency program not only is possible but also may constitute improved learning opportunity for residents. Follow-up work is needed to evaluate the effectiveness of this model on both learning and clinical practice. PMID:28919831
Magnetic viscosity phenomena in exchange coupled CoFe /MnIr bilayers
NASA Astrophysics Data System (ADS)
Kim, Dong Young; Kim, C. O.; Tsunoda, M.; Yamaguchi, M.; Yabugami, S.; Takahashi, M.
2007-05-01
The complex permeability spectra were measured in the low (10Hz-1MHz) and microwave (100MHz-9GHz) frequency ranges in CoFe /MnIr bilayers. The low frequency permeability spectra showed the magnetic viscosity effect below the critical antiferromagnet thickness (tcAF), but not at tAF
NASA Technical Reports Server (NTRS)
Cure, David; Weller, Thomas; Miranda, Felix A.
2011-01-01
In this paper, a comparison between Jerusalem Cross (JC) and Square Patch (SP) based Frequency Selected Surfaces (FSS) for low profile antenna applications is presented. The comparison is aimed at understanding the performance of low profile antennas backed by high impedance surfaces. In particular, an end loaded planar open sleeve dipole (ELPOSD) antenna is examined due to the various parameters within its configuration, offering significant design flexibility and a wide operating bandwidth. Measured data of the antennas demonstrate that increasing the number of unit cells improves the fractional bandwidth. The antenna bandwidth increased from 0.8% to 1.8% and from 0.8% to 2.7% for the JC and SP structures, respectively. The number of unit cells was increased from 48 to 80 for the JC-FSS and from 24 to 48 for the SP-FSS.
Multi-band microwave metamaterial absorber based on coplanar Jerusalem crosses
NASA Astrophysics Data System (ADS)
Wang, Guo-Dong; Liu, Ming-Hai; Hu, Xi-Wei; Kong, Ling-Hua; Cheng, Li-Li; Chen, Zhao-Quan
2014-01-01
The influence of the gap on the absorption performance of the conventional split ring resonator (SRR) absorber is investigated at microwave frequencies. Our simulated results reveal that the geometry of the square SRR can be equivalent to a Jerusalem cross (JC) resonator and its corresponding metamaterial absorber (MA) is changed to a JC absorber. The JC MA exhibits an experimental absorption peak of 99.1% at 8.72 GHz, which shows an excellent agreement with our simulated results. By simply assembling several JCs with slightly different geometric parameters next to each other into a unit cell, a perfect multi-band absorption can be effectively obtained. The experimental results show that the MA has four distinct and strong absorption peaks at 8.32 GHz, 9.8 GHz, 11.52 GHz and 13.24 GHz. Finally, the multi-reflection interference theory is introduced to interpret the absorption mechanism.
NASA Astrophysics Data System (ADS)
Shin, Sang Yong; Woo, Kuk Je; Hwang, Byoungchul; Kim, Sangho; Lee, Sunghak
2009-04-01
The fracture toughness in the transition-temperature region of three American Petroleum Institute (API) X70 and X80 pipeline steels was analyzed in accordance with the American Society for Testing and Materials (ASTM) E1921-05 standard test method. The elastic-plastic cleavage fracture toughness ( K Jc ) was determined by three-point bend tests, using precracked Charpy V-notch (PCVN) specimens; the measured K Jc values were then interpreted by the three-parameter Weibull distribution. The fracture-toughness test results indicated that the master curve and the 98 pct confidence curves explained the variation in the measured fracture toughness well. The reference temperatures obtained from the fracture-toughness test and index temperatures obtained from the Charpy impact test were lowest in the X70 steel rolled in the two-phase region, because this steel had smaller effective grains and the lowest volume fraction of hard phases. In this steel, few hard phases led to a higher resistance to cleavage crack initiation, and the smaller effective grain size led to a higher possibility of crack arrest, thereby resulting in the best overall fracture properties. Measured reference temperatures were then comparatively analyzed with the index temperatures obtained from the Charpy impact test, and the effects of microstructures on these temperatures were discussed.
2013-05-01
Biodegradation of Nitroaromatic Compounds; Spain, J.C., Ed.; Plenum Press: New York , 1995; pp 69–85. Renoux, A.Y.; Sarrazin, M.; Hawari, J.; Sunahara...in Contaminated Soil. In Biodegradation of Nitroaromatic Compounds. Spain, J.C., Ed.; Plenum Press: New York , 1995; pp 1–18. Robidoux, P.Y...CANDIDA 1. INTRODUCTION Many sites associated with military operations that involve munition manufacturing, disposal , testing, and training
Evaluation of Mouse Wound Models for Probiotics-Based Wound Infection Prevention Study
2016-06-01
Martinez MA, Valdez JC. Bacteriotherapy with Lactobacillus plantarum in burns. Int Wound J. 2009; 6(1):73-81. 3. Valdéz JC, Peral MC, Rachid M...Santana M, Perdigón G. Interference of Lactobacillus plantarum with Pseudomonas aeruginosa in vitro and in infected burns: the potential use of...used. The punch and skin flap models are reproducible murine models for wounding and infection. The use of probiotic ( Lactobacillus reuteri) had
Aircraft Enroute Command and Control Comms Redesign Mechanical Documentation
2015-12-01
and power equipment is secured. Custom racks , with 8 server rack bays, are mounted to the pallet, with 2 desk stations for equipment operators...conventional rack equipment. Equipment in the original system was larger and heavier than the new equipment selected for the NG-JC2S. Battery backup was...purposes. The equipment also needed to be easily removable in the event of equipment failure. Surplus rack space available in the NG-JC2S system allowed
Predicting Rediated Noise With Power Flow Finite Element Analysis
2007-02-01
Defence R&D Canada – Atlantic DEFENCE DÉFENSE & Predicting Rediated Noise With Power Flow Finite Element Analysis D. Brennan T.S. Koko L. Jiang J...PREDICTING RADIATED NOISE WITH POWER FLOW FINITE ELEMENT ANALYSIS D.P. Brennan T.S. Koko L. Jiang J.C. Wallace Martec Limited Martec Limited...model- or full-scale data before it is available for general use. Brennan, D.P., Koko , T.S., Jiang, L., Wallace, J.C. 2007. Predicting Radiated
Contreras, Rubén H; dos Santos, Francisco P; Ducati, Lucas C; Tormena, Cláudio F
2010-12-01
Adequate analyses of canonical molecular orbitals (CMOs) can provide rather detailed information on the importance of different σ-Fermi contact (FC) coupling pathways (FC term transmitted through the σ-skeleton). Knowledge of the spatial distribution of CMOs is obtained by expanding them in terms of natural bond orbitals (NBOs). Their relative importance for transmitting the σ-FC contribution to a given spin-spin coupling constants (SSCCs) is estimated by resorting to the expression of the FC term given by the polarisation propagator formalism. In this way, it is possible to classify the effects affecting such couplings in two different ways: delocalisation interactions taking place in the neighbourhood of the coupling nuclei and 'round the ring' effects. The latter, associated with σ-ring currents, are observed to yield significant differences between the FC terms of (2)J(C2H3) and (2)J(C3H2) SSCCs which, consequently, are taken as probes to gauge the differences in σ-ring currents for the five-membered rings (furan, thiophene, selenophene and pyrrol) and also for the six-membered rings (benzene, pyridine, protonated pyridine and N-oxide pyridine) used in the present study. Copyright © 2010 John Wiley & Sons, Ltd.
Agarwal, Parinita; Dabi, Mitali; More, Prashant; Patel, Khantika; Jana, Kalyanashis; Agarwal, Pradeep K
2016-01-01
Plants in ecosystems are simultaneously exposed to abiotic and biotic stresses, which restrict plant growth and development. The complex responses to these stresses are largely regulated by plant hormones, which in turn, orchestrate the different biochemical and molecular pathways to maneuver stress tolerance. The PR-10 protein family is reported to be involved in defense regulation, stress response and plant growth and development. The JcPR-10a overexpression resulted in increased number of shoot buds in tobacco (Nicotiana tabacum), which could be due to high cytokinin to auxin ratio in the transgenics. The docking analysis shows the binding of three BAP molecules at the active sites of JcPR-10a protein. JcPR-10a transgenics showed enhanced salt tolerance, as was evident by increased germination rate, shoot and root length, relative water content, proline, soluble sugar and amino acid content under salinity. Interestingly, the transgenics also showed enhanced endogenous cytokinin level as compared to WT, which, further increased with salinity. Exposure of gradual salinity resulted in increased stomatal conductance, water use efficiency, photosynthesis rate and reduced transpiration rate. Furthermore, the transgenics also showed enhanced resistance against Macrophomina fungus. Thus, JcPR-10a might be working in co-ordination with cytokinin signaling in mitigating the stress induced damage by regulating different stress signaling pathways, leading to enhanced stress tolerance.
The interaction of Ag with Bi-Pb-Sr-Ca-Cu-O superconductor
NASA Astrophysics Data System (ADS)
Dou, S. X.; Song, K. H.; Liu, H. K.; Sorrell, C. C.; Apperley, M. H.; Gouch, A. J.; Savvides, N.; Hensley, D. W.
1989-10-01
Bi-Pb-Sr-Ca-Cu-O superconductor compounds have been doped with up to 30 wt% Ag, sintered under variable oxygen partial pressure, and characterised in terms of the electrical and crystallographic behaviour. In contrast to previous reports that claim that Ag is the only metal non-poisoning to the superconductivity of Bi-Sr-Ca-Cu-O (BSCCO), it has been found that Ag additions to Bi-Pb-Sr-Ca-Cu-O depress Tc and Jc drastically and cause a large decrease in lattice parameters when samples are treated in air or pure oxygen. However, the lattice parameters, Tc and Jc remain unaffected by Ag additions when samples are heat treated in 0.030-0.067 atm oxygen. It is clear that the Ag reacts with and destabilises the superconducting phase when the samples are treated in air or pure oxygen while, when the samples are heat treated in low oxygen partial pressures, the Ag remains as an isolated inert metal phase that improves the weak links between the grains. This discovery clearly shows the feasibility of Ag-clad superconductor wire. For Ag-clad superconductor tape of 0.1 mm 2 cross sectional area heat treated in air, Jc was measured to be 54 A/cm 2. The same specimen sintered in 0.067 atm oxygen showed that the Jc increased to 2078 A/cm 2.
NASA Technical Reports Server (NTRS)
Ofek, E. O.; Fox, D.; Cenko, Stephen B.; Sullivan, M; Gnat, O.; Frail, D. A.; Horesh, A.; Corsi, A.; Quimby, R. M.; Gehrels, N.;
2013-01-01
The optical light curve of some supernovae (SNe) may be powered by the outward diffusion of the energy deposited by the explosion shock (the so-called shock breakout) in optically thick (Tau approx > 30) circumstellar matter (CSM). Recently, it was shown that the radiation-mediated and radiation-dominated shock in an optically thick wind must transform into a collisionless shock and can produce hard X-rays. The X-rays are expected to peak at late times, relative to maximum visible light. Here we report on a search, using Swift/XRT and Chandra, for X-ray emission from 28 SNe that belong to classes whose progenitors are suspected to be embedded in dense CSM. Our sample includes 19 Type IIn SNe, one Type Ibn SN, and eight hydrogen-poor superluminous SNe (SLSN-I such as SN 2005ap). Two SNe (SN 2006jc and SN 2010jl) have X-ray properties that are roughly consistent with the expectation for X-rays from a collisionless shock in optically thick CSM. However, the X-ray emission from SN 2006jc can also be explained as originating in an optically thin region. Thus, we propose that the optical light curve of SN 2010jl is powered by shock breakout in CSM. We suggest that two other events (SN 2010al and SN 2011ht) were too X-ray bright during the SN maximum optical light to be explained by the shock-breakout model.We conclude that the light curves of some, but not all, SNe IIn/Ibn are powered by shock breakout in CSM. For the rest of the SNe in our sample, including all of the SLSN-I events, our X-ray limits are not deep enough and were typically obtained too early (i.e., near the SN maximum light) for definitive conclusions about their nature. Late-time X-ray observations are required in order to further test whether these SNe are indeed embedded in dense CSM. We review the conditions required for a shock breakout in a wind profile. We argue that the timescale, relative to maximum light, for the SN to peak in X-rays is a probe of the column density and the density profile above the shock region. In SNe whose X-ray emission slowly rises, and peaks at late times, the optical light curve is likely powered by the diffusion of shock energy in a dense CSM. We note that if the CSM density profile falls faster than a constant-rate wind-density profile, then X-rays may escape at earlier times than estimated for the wind-profile case. Furthermore, if the CSM has a region in which the density profile is very steep relative to a steady wind-density profile, or if the CSM is neutral, then the radio free-free absorption may be sufficiently low for radio emission to be detected.
Brooks, Morgan M; Neelam, Sudha; Fudala, Rafal; Gryczynski, Ignacy; Cammarata, Patrick R
2013-01-01
Dissipation of the electrochemical gradient across the inner mitochondrial membrane results in mitochondrial membrane permeability transition (mMPT), a potential early marker for the onset of apoptosis. In this study, we demonstrate a role for glycogen synthase kinase-3β (GSK-3β) in regulating mMPT. Using direct inhibition of GSK-3β with the GSK-3β inhibitor SB216763, mitochondria may be prevented from depolarizing (hereafter referred to as mitoprotection). Cells treated with SB216763 showed an artifact of fluorescence similar to the green emission spectrum of the JC-1 dye. We demonstrate the novel use of spectral deconvolution to negate the interfering contributing fluorescence by SB216763, thus allowing an unfettered analysis of the JC-1 dye to determine the mitochondrial membrane potential. Secondary cultures of virally transfected human lens epithelial cells (HLE-B3) were exposed to acute hypoxic conditions (approximately 1% O₂) followed by exposure to atmospheric oxygen (approximately 21% O₂). The fluorescent dye JC-1 was used to monitor the extent of mitochondrial depolarization upon exposure of inhibitor treatment relative to the control cells (mock inhibition) in atmospheric oxygen. Annexin V-fluorescein isothiocyanate/propidium iodide staining was implemented to determine cell viability. Treatment of HLE-B3 cells with SB216763 (12 µM), when challenged by oxidative stress, suppressed mitochondrial depolarization relative to control cells as demonstrated with JC-1 fluorescent dye analysis. Neither the control nor the SB216763-treated HLE-B3 cells tested positive with annexin V-fluorescein isothiocyanate/propidium iodide staining under the conditions of the experiment. Inhibition of GSK-3β activity by SB216763 blocked mMPT relative to the slow but consistent depolarization observed with the control cells. We conclude that inhibition of GSK-3β activity by the GSK-3β inhibitor SB216763 provides positive protection against mitochondrial depolarization.
Kozutsumi, Daisuke; Tsunematsu, Masako; Yamaji, Taketo; Kino, Kohsuke
2007-01-01
Cry-consensus peptide is a linearly linked peptide of T-cell epitopes for the management of Japanese cedar (JC) pollinosis and is expected to become a new drug for immunotherapy. However, the mechanism of T-cell epitopes in allergic diseases is not well understood, and thus, a simple in vitro procedure for evaluation of its biological activity is desired. Peripheral blood mononuclear cells (PBMC) were isolated from 27 JC pollinosis patients and 10 healthy subjects, and cultured in vitro for 4 days in the presence of Cry-consensus peptide and (3)H-thymidine. The relationship between growth stimulation (stimulation index; SI) and antigen-specific IgE levels in serum was also investigated in JC pollinosis patients. Moreover, to confirm the importance of the primary sequence in Cry-consensus peptide, heat-treated Cry-consensus peptide and a mixture of the amino acids of which Cry-consensus peptide is composed, and their (3)H-thymidine uptake was compared with Cry-consensus peptide. Finally, whether Cry-consensus peptide stimulates PBMCs from healthy subjects was investigated. The mean SI of JC patients showed a good correlation with Cry-consensus peptide concentration in the culture medium; however, the SI was independent of the anti-Cry j 1 IgE level. Heat-denatured Cry-consensus peptide retained a PBMC proliferation stimulatory effect comparable to the original Cry-consensus peptide, while the mixture of amino acids constituting Cry-consensus peptide did not stimulate PBMC proliferation. PBMCs from healthy subjects did not respond to Cry-consensus peptide at all. These data indicate that the PBMC response of patients suffering from JC pollinosis to Cry-consensus peptide is specific for the sequence of T cell epitopes thereof and may be useful for the evaluation of the efficacy of Cry-consensus peptide in vivo.
Modeling and Optimization for Epitaxial Growth: Transport and Growth Studies
1999-01-01
effect . It is expressed as the sum of these two components j i jC i jT i where jC i and jT i denote the concentration driven and thermally driven...improve manufacturing effectiveness for epitaxial growth of silicon and silicon-germanium (Si-Ge) thin films on a silicon wafer. Growth takes place in the...non-uniformity to compensate for the effects of other phenomena such as reactant depletion, gas heating and gas phase reactions, thermal diffusion of
NASA Astrophysics Data System (ADS)
Voelzke, M. R.
2016-11-01
This work is based on a systematic analysis of images of 1P/Halley comet collected during its penultimate and ultimate approaches, i.e., in 1910 and in 1986. The present research basically characterised, identified, classified, measured and compared some of the tail structures of comet 1P/Halley like DEs, wavy structures and solitons. The images illustrated in the Atlas of Comet Halley 1910 II (Donn et al., 1986), which shows the comet in its 1910 passage, were compared with the images illustrated in The International Halley Watch Atlas of Large-Scale Phenomena (Brandt et al., 1992), which shows the comet in its 1986 passage. While two onsets of DEs were discovered after the perihelion passage in 1910, the average value of the corrected cometocentric velocity Vc was (57 ± 15) km/s; ten were discovered after the perihelion passage in 1986 with an average of corrected velocities equal to (130 ± 37) km/s. The mean value of the corrected wavelength of wavy structures, in 1910, is equal to (1.7 ± 0.1) x 10^6 km and in 1986 is (2.2 ± 0.2) x 10^6 km. The mean value of the amplitude A of the wave, in 1910, is equal to (1.4 ± 0.1) x 10^5 km and in 1986 it is equal to (2.8 ± 0.5) x 10^5 km. The goals of this research are to report the results obtained from the analysis of the P/Halleýs 1910 and 1986 images, to provide empirical data for comparison and to form the input for future physical/theoretical work. Referências [1] Brandt, J.C., Niedner Jr., M.B. & Rahe, J. 1992. International Halley Watch Atlas of Large-Scale Phenomena. University of Colorado-Boulder (printed by Johnson Printing Co., Boulder, CO) [2] Donn, B., Rahe, J. & Brandt, J.C. 1986. Atlas of Comet Halley 1910 II. NASA SP-488
Structural and critical current properties in Al-doped MgB 2
NASA Astrophysics Data System (ADS)
Zheng, D. N.; Xiang, J. Y.; Lang, P. L.; Li, J. Q.; Che, G. C.; Zhao, Z. W.; Wen, H. H.; Tian, H. Y.; Ni, Y. M.; Zhao, Z. X.
2004-08-01
A series of Al-doped Mg 1- xAl xB 2 samples have been fabricated and systematic study on structure and superconducting properties have been carried out for the samples. In addition to a structural transition observed by XRD, TEM micrographs showed the existence of a superstructure of double c-axis lattice constant along the direction perpendicular to the boron honeycomb sheet. In order to investigate the effect of Al doping on flux pinning and critical current properties in MgB 2, measurements on the superconducting transition temperature Tc, irreversible field Birr and critical current density Jc were performed too, for the samples with the doping levels lower than 0.15 in particular. These experimental observations were discussed in terms of Al doping induced changes in carrier concentration.
NASA Astrophysics Data System (ADS)
Wang, Xiaolong; Tan, Zhenyu; Pan, Jie; Chen, Xinxian
2016-08-01
In this work the effects of O2 concentration on the pulsed dielectric barrier discharge in helium-oxygen mixture at atmospheric pressure have been numerically researched by using a one-dimensional fluid model in conjunction with the chosen key species and chemical reactions. The reliability of the used model has been examined by comparing the calculated discharge current with the reported experiments. The present work presents the following significant results. The dominative positive and negative particles are He2+ and O2-, respectively, the densities of the reactive oxygen species (ROS) get their maxima nearly at the central position of the gap, and the density of the ground state O is highest in the ROS. The increase of O2 concentration results in increasingly weak discharge and the time lag of the ignition. For O2 concentrations below 1.1%, the density of O is much higher than other species, the averaged dissipated power density presents an evident increase for small O2 concentration and then the increase becomes weak. In particular, the total density of the reactive oxygen species reaches its maximums at the O2 concentration of about 0.5%. This characteristic further convinces the experimental observation that the O2 concentration of 0.5% is an optimal O2/He ratio in the inactivation of bacteria and biomolecules when radiated by using the plasmas produced in a helium oxygen mixture. supported by the Fundamental Research Funds of Shandong University, China (No. 2016JC016)
The role of mitochondrial reactive oxygen species in pH regulation in articular chondrocytes.
Milner, P I; Wilkins, R J; Gibson, J S
2007-07-01
To examine the effect of O(2) and the role, and source, of reactive oxygen species (ROS) on pH regulation in articular chondrocytes. Cartilage from equine metacarpo/tarsophalangeal joints was digested (collagenase) to isolate chondrocytes and loaded with 2',7'-bis-2-(carboxyethyl)-5(6)-carboxylfluorescein, a pH-sensitive fluorophore. O(2) tension was maintained using Eschweiler tonometers and a Wosthoff gas mixer. Cells were exposed to agents which alter ROS levels, mitochondrial inhibitors and/or inhibitors of protein phosphorylation. ROS levels were determined by dichlorofluorescein and mitochondrial membrane potential measured using JC-1. pH homeostasis was dependent on ROS. Na(+)/H(+) exchanger (NHE) activity was inhibited at low O(2) tension (acid efflux reducing from 2.30+/-0.05 to 1.27+/-0.11mMmin(-1) at 1%). NHE activity correlated with ROS levels (r(2)=0.65). ROS levels were increased by antimycin A (with levels at 1% O(2) tension increasing from 59+/-9% of the value at 20% to 87+/-7%), but reduced by rotenone, myxothiazol and diphenyleneiodonium. Hypoxia induced depolarisation of the mitochondrial membrane potential (with JC-1 red-green fluorescence ratio at 1% O(2) tension decreasing to 40+/-10% of the value at 20%). The response to changes in O(2) and to antimycin A was inhibited by staurosporine, wortmanin and calyculin A. The fall in ROS levels in hypoxia reduces the ability of articular chondrocytes to regulate pH, inhibiting NHE activity via changes in protein phosphorylation. The site of ROS generation is likely to be mitochondrial electron transport chain complex III. These effects are important to understanding normal chondrocyte function and response to altered O(2) tension.
California serogroup and Powassan virus infection of cats.
Keane, D P; Parent, J; Little, P B
1987-08-01
One hundred and seventy five sera from cats in Ontario, Canada, were tested for hemagglutination inhibition (HI) antibodies to three arboviruses; namely, Powassan (POW) of the Flavivirus serogroup, and Snowshoe hare (SSH) and Jamestown Canyon (JC) viruses of the California (CAL) serogroup. All sera were negative for antibodies to POW virus. Twelve cats possessed CAL serogroup antibodies including 3 with antibodies to SSH alone, 6 with antibodies to JC alone, and 3 with antibodies to both SSH and JC antigens. POW virus was inoculated into seven cats, one intracerebrally and six intravenously. Neurologic signs were not detected in any of the cats. Histologic lesions of a nonsuppurative encephalitis and encephalomyelitis were observed in the intracerebrally inoculated cat and in one of the intravenously inoculated cats, respectively. POW virus was not isolated from the brain or spinal cord of either of these two cats. HI antibodies were detected in the sera of all inoculated animals. HI antibodies were not detected in the CSF of any animal.
Progressive Multifocal Leukoencephalopathy: Endemic Viruses and Lethal Brain Disease.
Haley, Sheila A; Atwood, Walter J
2017-09-29
In 1971, the first human polyomavirus was isolated from the brain of a patient who died from a rapidly progressing demyelinating disease known as progressive multifocal leukoencephalopathy. The virus was named JC virus after the initials of the patient. In that same year a second human polyomavirus was discovered in the urine of a kidney transplant patient and named BK virus. In the intervening years it became clear that both viruses were widespread in the human population but only rarely caused disease. The past decade has witnessed the discovery of eleven new human polyomaviruses, two of which cause unusual and rare cancers. We present an overview of the history of these viruses and the evolution of JC polyomavirus-induced progressive multifocal leukoencephalopathy over three different epochs. We review what is currently known about JC polyomavirus, what is suspected, and what remains to be done to understand the biology of how this mostly harmless endemic virus gives rise to lethal disease.
Yang, Yumei; Luo, Zhu; Zhang, Mengru; Liu, Chang; Gong, Ming; Zou, Zhurong
2016-04-01
H(+)-pyrophosphatase (H(+)-PPase) is a primary pyrophosphate (PPi)-energized proton pump to generate electrochemical H(+) gradient for ATP production and substance translocations across membranes. It plays an important role in stress adaptation that was intensively substantiated by numerous transgenic plants overexpressing H(+)-PPases yet devoid of any correlated studies pointing to the elite energy plant, Jatropha curcas. Herein, we cloned the full length of J. curcas H(+)-PPase (JcVP1) complementary DNA (cDNA) by reverse transcription PCR, based on the assembled sequence of its ESTs highly matched to Hevea brasiliensis H(+)-PPase. This gene encodes a polypeptide of 765 amino acids that was predicted as a K(+)-dependent H(+)-PPase evolutionarily closest to those of other Euphorbiaceae plants. Many cis-regulatory elements relevant to environmental stresses, molecular signals, or tissue-specificity were identified by promoter prediction within the 1.5-kb region upstream of JcVP1 coding sequence. Meanwhile, the responses of JcVP1 expression to several common abiotic stresses (salt, drought, heat, cold) were characterized with a considerable accordance with the inherent stress tolerance of J. curcas. Moreover, we found that the heterologous expression of JcVP1 could significantly improve the salt tolerance in both recombinant Escherichia coli and Saccharomyces cerevisiae, and this effect could be further fortified in yeast by N-terminal addition of a vacuole-targeting signal peptide from the H(+)-PPase of Trypanosoma cruzi.
NASA Astrophysics Data System (ADS)
Radtke, R. J.; Levin, K.
1995-02-01
Experiments on the cuprate superconductors demonstrate that these materials may be viewed as a stack of Josephson junctions along the direction normal to the CuO 2 planes (the c-axis). In this paper, we present a model which describes this intrinsic Josephson coupling in terms of incherent quasiparticle hopping along the c-axis arising from wave-function overlap, impurity-assisted hopping, and boson-assised hopping. We use this model to compute the magnitude and temperature T dependence of the resulting Josephson critical current jc( T) for s- and d-wave superconductors. Contrary to other approaches, d-wave pairing in this model is compatible with an intrinsic Josephson effect at all hole concentrations and leads to jc( T) αT at low T. By parameterizing our theory with c-axis resistivity data from YBa 2Cu 3O 7-δ (YBCO), we estimate jc( T) for optimally doped and underdoped members of this family. jc( T) can be measured either directly or indirectly through microwave penetration depth experiments, and current measurements on Bi 2Sr 2CaCu 2O 8 and La 2- xSr xCuO 4 are found to be consistent with s-wave pairing and the dominance of assisted hopping processes. The situation in YBCO is still unclear, but our estimates suggest that further experiments on this compound would be of great help in elucidating the validity of our model in general and the pairing symmetry in particular.
Chen, Xuanzhen; Peng, Yong; Peng, Shan; Yao, Song; Chen, Chao; Xu, Ping
2017-01-01
This study aims to investigate the flow and fracture behavior of aluminum alloy 6082-T6 (AA6082-T6) at different strain rates and triaxialities. Two groups of Charpy impact tests were carried out to further investigate its dynamic impact fracture property. A series of tensile tests and numerical simulations based on finite element analysis (FEA) were performed. Experimental data on smooth specimens under various strain rates ranging from 0.0001~3400 s-1 shows that AA6082-T6 is rather insensitive to strain rates in general. However, clear rate sensitivity was observed in the range of 0.001~1 s-1 while such a characteristic is counteracted by the adiabatic heating of specimens under high strain rates. A Johnson-Cook constitutive model was proposed based on tensile tests at different strain rates. In this study, the average stress triaxiality and equivalent plastic strain at facture obtained from numerical simulations were used for the calibration of J-C fracture model. Both of the J-C constitutive model and fracture model were employed in numerical simulations and the results was compared with experimental results. The calibrated J-C fracture model exhibits higher accuracy than the J-C fracture model obtained by the common method in predicting the fracture behavior of AA6082-T6. Finally, the Scanning Electron Microscope (SEM) of fractured specimens with different initial stress triaxialities were analyzed. The magnified fractographs indicate that high initial stress triaxiality likely results in dimple fracture.
LONGITUDINAL MONITORING OF TREE AIRBORNE POLLEN IN JAPAN.
Kishikawa, Reiko; Kotoh, Eiko; Oshikawa, Chie; Soh, Nobuo; Shimoda, Terufumi; Saito, Akemi; Sahashi, Norio; Enomoto, Tadao; Usami, Atsushi; Teranishi, Hidetoyo; Fujisaki, Yohko; Yokoyama, Toshitaka; Murayama, Kohji; Imai, Tohru; Fukutomi, Yuma; Taniguchi, Masami; Iwanaga, Tomoaki
2017-01-01
In Japan patients with Japanese Cedar (JC) pollinosis have increased nation widely since the latter of 1970's. The Ministry of Health and Welfare of Japanese Governments has begun to take preventive measures against JC pollinosis and airborne pollen monitoring has begun to investigate as a causative agent since 1986. We have estimated the longitudinal investigation result for successful prevention and treatment against pollinosis in Japan. We have monitored airborne pollen all year around since July 1986 by gravitational pollen sampler, Durham's sampler, at more than 20 locations in the Japanese Islands. Pollen samples were sent to our hospital and counted pollen number per cm 2 after stained by Calberla solution and then classified main pollen grains as a causative agent of pollinosis. JC pollen number was the most of all, more than 40%, next cypress family, about 20%. They were occupied of more than 60% of all and they increased with the remarkable annual fluctuation as the allergen of JC pollinosis. Beech family pollen counting were also increasing and occupied about 10% of all pollen counts. In Hokkaido the prevalence of birch family pollen count was larger than that in other districts. There is cross-reactivity between beech and birch family which related with oral allergic syndrome.Perspective and Conclusion: In future new occurrences of oral allergy syndrome due to increasing allergic tree pollen grains would be appeared. The contentious pollen research should be important for patients with pollinosis in Japan.
Isolation and application of Gordonia sp. JC11 for removal of boat lubricants.
Chanthamalee, Jirapat; Luepromchai, Ekawan
2012-01-01
Boat lubricants are continuously released into the marine environment and thereby cause chronic oil pollution. This study aims to isolate lubricant-degrading microorganisms from Thai coastal areas as well as to apply a selected strain for removal of boat lubricants. Ten microorganisms in the genera of Gordonia, Microbacterium, Acinetobacter, Pseudomonas, Brucella, Enterococcus and Candida were initially isolated by crude oil enrichment culture techniques. The lubricant-removal activity of these isolates was investigated with mineral-based lubricants that had been manufactured for the 4-stroke diesel engines of fishing boats. Gordonia sp. JC11, the most effective strain was able to degrade 25-55% of 1,000 mg L(-1) total hydrocarbons in six tested lubricants, while only 0-15% of the lubricants was abiotically removed. The bacterium had many characteristics that promoted lubricant degradation such as hydrocarbon utilization ability, emulsification activity and cell surface hydrophobicity. For bioaugmentation treatment of lubricant contaminated seawater, the inoculum of Gordonia sp. JC11 was prepared by immobilizing the bacterium on polyurethane foam (PUF). PUF-immobilized Gordonia sp. JC11 was able to remove 42-56% of 100-1,000 mg L(-1) waste lubricant No. 2 within 5 days. This lubricant removal efficiency was higher than those of free cells and PUF without bacterial cells. The bioaugmentation treatment significantly increased the number of lubricant-degrading microorganisms in the fishery port seawater microcosm and resulted in rapid removal of waste lubricant No. 2.
The Research of EAST Pedestal Structure and Preliminary Application
NASA Astrophysics Data System (ADS)
Wang, Tengfei; Zang, Qing; Han, Xiaofeng; Xiao, Shumei; Hu, Ailan; Zhao, Junyu
2016-10-01
The pedestal characteristic is an important basis for high confinement mode (H-mode) research. Because of the finite spatial resolution of Thomson scattering (TS) diagnostic on Experimental Advanced Superconducting Tokamak (EAST), it is necessary to characterize the pedestal with a suitable functional form. Based on simulated and experimental data of EAST, it is shown that the two-line method with a bilinear fitting has better reproducibility of pedestal parameters than hyperbolic tangent (tanh) and modified hyperbolic tangent (mtanh) methods. This method has been applied to EAST type I edge localized mode (ELM) discharges, and the electron pedestal density is found to be proportional to the line-averaged density and the edge pressure gradient is found to be proportional to the pedestal pressure. Furthermore, the ion poloidal gyro-radius has been identified as the suitable parameter to describe the pedestal pressure width. supported by National Natural Science Foundation of China (Nos. 11275233 and 11405206), and the National Magnetic Confinement Fusion Science Program of China (No. 2013GB112003), and Science Foundation of Institute of Plasma Physics, Chinese Academy of Sciences (No. DSJJ-15-JC01)
Effect of grain-boundary flux pinning in MgB 2 with columnar structure
NASA Astrophysics Data System (ADS)
Kim, D. H.; Hwang, T. J.; Cha, Y. J.; Seong, W. K.; Kang, W. N.
2009-10-01
We studied the flux pinning properties by grain boundaries in MgB 2 films prepared by using a hybrid physical chemical vapor deposition method on the c-axis oriented sapphire substrates. All the films we report here had the columnar grains with the growth direction perpendicular to the substrates and the grain sizes in the range of a few hundred nanometers. At very low magnetic fields, no discernable grain-boundary (GB) pinning effect was observed in all measuring temperatures, but above those fields, the effect of GB flux pinning was observed as enhanced critical current densities ( Jcs) and reduced resistances when an external magnetic field ( B) was aligned parallel to the c-axis. We interpret the B dependence of Jc in the terms of flux line lattice shear inside the columnar grains activated by dislocations of Frank-Read source while the flux lines pinned by GB act as anchors for dislocations. Magnetic field dependence of flux pinning force density for B parallel to the c-axis was reasonably explained by the above model.
Free flux flow in two single crystals of V3Si with slightly different pinning strengths
NASA Astrophysics Data System (ADS)
Gafarov, O.; Gapud, A. A.; Moraes, S.; Thompson, J. R.; Christen, D. K.; Reyes, A. P.
2010-10-01
Results of recent measurements on two very clean, single-crystal samples of the A15 superconductor V3Si are presented. Magnetization and transport data already confirmed the ``clean'' quality of both samples, as manifested by: (i) high residual resistivity ratio, (ii) very low critical current densities, and (iii) a ``peak'' effect in the field dependence of critical current. The (H,T) phase line for this peak effect is shifted in the slightly ``dirtier'' sample, which consequently also has higher critical current density Jc(H). High-current Lorentz forces are applied on mixed-state vortices in order to induce the highly ordered free flux flow (FFF) phase, using the same methods as in previous work. A traditional model by Bardeen and Stephen (BS) predicts a simple field dependence of flux flow resistivity ρf(H), presuming a field-independent flux core size. A model by Kogan and Zelezhina (KZ) takes core size into account, and predict a clear deviation from BS. In this study, ρf(H) is confirmed to be consistent with predictions of KZ, as will be discussed.
1991-07-01
Massachusetts "A Microscopy Study of Impact Damage on Epoxy-Matrix ..... . . . 8-1 Carbon Fiber Composites " D.J. Boll, W.D. Bascom and J.C. Weidner Hercules...ON EPOXY-MATRIX CARBON FIBER COMPOSITES D.J. Boll, W.D. Bascom and J.C. Weidner Hercules Aerospace Magna, Utah A Microscopy Study of Impact Damage on...Epoxy-Matrix Carbon Fiber Composites D. 3. Boll, W. D. Bascom, J. C. Weidner and W. J. Murri Hercules Aerospace Magna, Utah Abstract The damage
Direct Broad-Range Detection of Alphaviruses in Mosquito Extracts
2007-11-25
D.J., Robbins, D.W., Hannis , J.C., Harrell, P.M., Massire, C., Hall, T.A., Jiang, Y., Ranken, R., Drader, J.J., White, N., McNeil, J.A., Crooke, S.T...962. Hofstadler, S.A., Sampath, R., Blyn, L.B., Eshoo, M.W., Hall, T.A., Jiang, Y., Drader, J.J., Hannis , J.C., Sannes-Lowery, K.A., Cummins, L.L...H., Hannis , J., Harrell, P.M., Neuman, B., Buchmeier, M.J., Jiang, Y., Ranken, R., Drader, J., Samant, V., Griffey, R.H., McNeil, J.A., Crooke, S.T
Micro Computer Feedback Report for the Strategic Leader Development Inventory; Source Code
1994-03-01
SEL5 ;exit if error CALL SELZCT SCRZEN ;display select screen JC SEL4 ;no files in directory .------- display the files NOV BX, [BarPos] ;starting...SEL2 ;if not goto next test imp SEL4 ; Ecit SEL2: CUP AL,ODh ;in it a pick ? 3Z SEL3 ;if YES exit loop ------- see if an active control key was...file CALL READCOMFIG eread file into memory JC SEL5 ;exit to main menu CALL OPEN DATA FILE ;is data arailable? SEL4 : CALL RELEASE_ _MDR ;release mom
Analysis of JC virus DNA replication using a quantitative and high-throughput assay
DOE Office of Scientific and Technical Information (OSTI.GOV)
Shin, Jong; Phelan, Paul J.; Chhum, Panharith
2014-11-15
Progressive Multifocal Leukoencephalopathy (PML) is caused by lytic replication of JC virus (JCV) in specific cells of the central nervous system. Like other polyomaviruses, JCV encodes a large T-antigen helicase needed for replication of the viral DNA. Here, we report the development of a luciferase-based, quantitative and high-throughput assay of JCV DNA replication in C33A cells, which, unlike the glial cell lines Hs 683 and U87, accumulate high levels of nuclear T-ag needed for robust replication. Using this assay, we investigated the requirement for different domains of T-ag, and for specific sequences within and flanking the viral origin, in JCVmore » DNA replication. Beyond providing validation of the assay, these studies revealed an important stimulatory role of the transcription factor NF1 in JCV DNA replication. Finally, we show that the assay can be used for inhibitor testing, highlighting its value for the identification of antiviral drugs targeting JCV DNA replication. - Highlights: • Development of a high-throughput screening assay for JCV DNA replication using C33A cells. • Evidence that T-ag fails to accumulate in the nuclei of established glioma cell lines. • Evidence that NF-1 directly promotes JCV DNA replication in C33A cells. • Proof-of-concept that the HTS assay can be used to identify pharmacological inhibitor of JCV DNA replication.« less
NASA Astrophysics Data System (ADS)
Kinoshita, A.; Takahashi, K.; Kobayashi, H.; Yamada, Y.; Ibi, A.; Fukushima, H.; Konishi, M.; Miyata, S.; Shiohara, Y.; Kato, T.; Hirayama, T.
2007-10-01
In order to obtain a high critical current, Ic, we have fabricated a thick GdBa2Cu3O7-x (GdBCO) film by the pulsed laser deposition (PLD) method on a PLD-CeO2/ion-beam assisted deposition (IBAD)-Gd2Zr2O7 (GZO)/hastelloy metal substrate. The film of a 3.6 μm thickness exhibited the highest critical current of 522 A/cm at self-field and at 77 K. It was found that a low volume fraction of a-axis oriented grains was obtained in the thick GdBCO films, compared to YBa2Cu3O7-x (YBCO) films. The GdBCO films showed a higher critical current density (Jc), than YBCO films in all thicknesses from 0.2 to 3.6 μm. Furthermore, we have improved Ic in a magnetic field by the introduction of artificial pinning centers using a 5 mol% ZrO2-doped GdBCO target. In the measurement of angular dependence of Ic, which was much improved at 0°, the magnetic field was parallel to the c-axis. The Ic value at 3 T was 59.5 A/cm at 0° and showed a minimum of 42.3 A/cm at 82° for the film of a 2.3 μm thickness. The minimum value at 3 T in angular dependence of Ic was about five times higher than that of the YBCO film and two times higher than that of pure the GdBCO film.
Rizk, Francine; Laverdure, Sylvain; d'Alençon, Emmanuelle; Bossin, Hervé; Dupressoir, Thierry
2018-01-01
The Lepidopteran ambidensovirus 1 isolated from Junonia coenia (hereafter JcDV) is an invertebrate parvovirus considered as a viral transduction vector as well as a potential tool for the biological control of insect pests. Previous works showed that JcDV-based circular plasmids experimentally integrate into insect cells genomic DNA. In order to approach the natural conditions of infection and possible integration, we generated linear JcDV- gfp based molecules which were transfected into non permissive Spodoptera frugiperda ( Sf9 ) cultured cells. Cells were monitored for the expression of green fluorescent protein (GFP) and DNA was analyzed for integration of transduced viral sequences. Non-structural protein modulation of the VP-gene cassette promoter activity was additionally assayed. We show that linear JcDV-derived molecules are capable of long term genomic integration and sustained transgene expression in Sf9 cells. As expected, only the deletion of both inverted terminal repeats (ITR) or the polyadenylation signals of NS and VP genes dramatically impairs the global transduction/expression efficiency. However, all the integrated viral sequences we characterized appear "scrambled" whatever the viral content of the transfected vector. Despite a strong GFP expression, we were unable to recover any full sequence of the original constructs and found rearranged viral and non-viral sequences as well. Cellular flanking sequences were identified as non-coding ones. On the other hand, the kinetics of GFP expression over time led us to investigate the apparent down-regulation by non-structural proteins of the VP-gene cassette promoter. Altogether, our results show that JcDV-derived sequences included in linear DNA molecules are able to drive efficiently the integration and expression of a foreign gene into the genome of insect cells, whatever their composition, provided that at least one ITR is present. However, the transfected sequences were extensively rearranged with cellular DNA during or after random integration in the host cell genome. Lastly, the non-structural proteins seem to participate in the regulation of p9 promoter activity rather than to the integration of viral sequences.
Distribution and cycling of lead in the high and low latitudinal Atlantic Ocean
NASA Astrophysics Data System (ADS)
Schlosser, C.; Menzel Barraqueta, J. L.; Rapp, I.; Pampin Baro, J.; Achterberg, E. P.
2016-02-01
Lead (Pb) is a toxic trace metal; even small quantities are lethal to most unicellular and multicellular organisms. Major sources of lead to the environment are the burning of coal, industrial mining, and the use of leaded gasoline (which has not been entirely phased out of use around the globe). These and other anthropogenic sources of Pb continue to pollute the environment and affect primary production and the development of heterotrophic organisms in the sea. Pb concentrations in oceanic waters are ten to a hundred times higher in surface waters than in deep waters (0.05 - 0.1 nmol L-1 compared to 1 - 5 pmol L-1), this deposition-like profile clearly reflecting the significant anthropogenic input of Pb to the ocean. In order to explore the cycling and fate of this anthropogenic Pb, we collected seawater from the polar North Atlantic (JC274 in 2013, GEOVIDE in 2014), the sub-tropical Atlantic (D361 in 2011 & M107 in 2014), the South Atlantic (JC068 in 2012), and the Atlantic sector of the Southern Ocean (JC271 in 2013). These samples were analyzed for their dissolved and soluble and total dissolvable Pb concentrations by off-line pre-concentration using a SeaFAST device (Elemental Science Inc.) and isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS, Thermo ElementXR). Results indicate that dissolved Pb exists mainly as colloidal species, which, as the precursors of larger particles are subsequently critical for the removal of lead from the water column. For example, the removal of colloidal Pb through particle scavenging was observed in the high productivity waters of the Mauritanian upwelling region and at the outlet of the La Plata River on the South American shelf. In terms of Pb pollution, highest Pb concentrations (up to 60 pmol L-1) were observed in the Agulhas current. But even remote locations, such as the northern Arctic Ocean and near South Georgia in the Southern Ocean, activities of man had an impact; the Pb concentrations of 30 pmol L-1 found there compare to modern values in the Baltic Sea.
Gadelha, Cibelle Gomes; Miranda, Rafael de Souza; Alencar, Nara Lídia M; Costa, José Hélio; Prisco, José Tarquinio; Gomes-Filho, Enéas
2017-05-01
Jatropha curcas is an oilseed species that is considered an excellent alternative energy source for fossil-based fuels for growing in arid and semiarid regions, where salinity is becoming a stringent problem to crop production. Our working hypothesis was that nitric oxide (NO) priming enhances salt tolerance of J. curcas during early seedling development. Under NaCl stress, seedlings arising from NO-treated seeds showed lower accumulation of Na + and Cl - than those salinized seedlings only, which was consistent with a better growth for all analyzed time points. Also, although salinity promoted a significant increase in hydrogen peroxide (H 2 O 2 ) content and membrane damage, the harmful effects were less aggressive in NO-primed seedlings. The lower oxidative damage in NO-primed stressed seedlings was attributed to operation of a powerful antioxidant system, including greater glutathione (GSH) and ascorbate (AsA) contents as well as catalase (CAT) and glutathione reductase (GR) enzyme activities in both endosperm and embryo axis. Priming with NO also was found to rapidly up-regulate the JcCAT1, JcCAT2, JcGR1 and JcGR2 gene expression in embryo axis, suggesting that NO-induced salt responses include functional and transcriptional regulations. Thus, NO almost completely abolished the deleterious salinity effects on reserve mobilization and seedling growth. In conclusion, NO priming improves salt tolerance of J. curcas during seedling establishment by inducing an effective antioxidant system and limiting toxic ion and reactive oxygen species (ROS) accumulation. Copyright © 2017 Elsevier GmbH. All rights reserved.
Chen, Xuanzhen; Peng, Shan; Yao, Song; Chen, Chao; Xu, Ping
2017-01-01
This study aims to investigate the flow and fracture behavior of aluminum alloy 6082-T6 (AA6082-T6) at different strain rates and triaxialities. Two groups of Charpy impact tests were carried out to further investigate its dynamic impact fracture property. A series of tensile tests and numerical simulations based on finite element analysis (FEA) were performed. Experimental data on smooth specimens under various strain rates ranging from 0.0001~3400 s-1 shows that AA6082-T6 is rather insensitive to strain rates in general. However, clear rate sensitivity was observed in the range of 0.001~1 s-1 while such a characteristic is counteracted by the adiabatic heating of specimens under high strain rates. A Johnson-Cook constitutive model was proposed based on tensile tests at different strain rates. In this study, the average stress triaxiality and equivalent plastic strain at facture obtained from numerical simulations were used for the calibration of J-C fracture model. Both of the J-C constitutive model and fracture model were employed in numerical simulations and the results was compared with experimental results. The calibrated J-C fracture model exhibits higher accuracy than the J-C fracture model obtained by the common method in predicting the fracture behavior of AA6082-T6. Finally, the Scanning Electron Microscope (SEM) of fractured specimens with different initial stress triaxialities were analyzed. The magnified fractographs indicate that high initial stress triaxiality likely results in dimple fracture. PMID:28759617
Tracing Jomon and Yayoi ancestries in Japan using ALDH2 and JC virus genotype distributions.
Miyamori, Daisuke; Ishikawa, Noboru; Idota, Nozomi; Kakiuchi, Yasuhiro; McLean, Stuart; Kitamura, Tadaichi; Ikegaya, Hiroshi
2015-01-01
According to the dual structure model, the modern Japanese ethnic population consists of a mixture of the Jomon people, who have existed in Japan since at least the New Stone Age, and the Yayoi people, who migrated to western Japan from China around the year 300 bc Some reports show that the Yayoi are linked to a mutation of the aldehyde dehydrogenase 2 gene (ALDH2). Recent viral studies indicate two major groups found in the Japanese population: a group with the CY genotype JC virus (JCV) and a group with the MY genotype JCV. It is unclear whether either genotype of the JC virus is related to the Jomon or Yayoi. In this study, we attempted to detect JCV genotypes and ALDH2 mutations from the DNA of 247 Japanese urine samples to clarify the relationship between the dual structure model and the JCV genotype through ALDH2 mutation analysis and JCV genotyping. The ALDH2 polymorphism among 66 JC virus-positive samples was analyzed, and it was found that the ALDH2 variant is significantly higher in the population with CY genotype JCV (51.5 %) than in the population with the MY genotype (24.2 %) (p < 0.05). From these findings, it may be inferred that the ALDH2 mutation, which is related to the Yayoi, is related to CY genotype JCV. When the Yayoi migrated to the Japanese archipelago, they brought the ALDH2 mutation as well as the CY genotype JCV.
Validation of the Intelligibility in Context Scale for Jamaican Creole-Speaking Preschoolers.
Washington, Karla N; McDonald, Megan M; McLeod, Sharynne; Crowe, Kathryn; Devonish, Hubert
2017-08-15
To describe validation of the Intelligibility in Context Scale (ICS; McLeod, Harrison, & McCormack, 2012a) and ICS-Jamaican Creole (ICS-JC; McLeod, Harrison, & McCormack, 2012b) in a sample of typically developing 3- to 6-year-old Jamaicans. One-hundred and forty-five preschooler-parent dyads participated in the study. Parents completed the 7-item ICS (n = 145) and ICS-JC (n = 98) to rate children's speech intelligibility (5-point scale) across communication partners (parents, immediate family, extended family, friends, acquaintances, strangers). Preschoolers completed the Diagnostic Evaluation of Articulation and Phonology (DEAP; Dodd, Hua, Crosbie, Holm, & Ozanne, 2006) in English and Jamaican Creole to establish speech-sound competency. For this sample, we examined validity and reliability (interrater, test-rest, internal consistency) evidence using measures of speech-sound production: (a) percentage of consonants correct, (b) percentage of vowels correct, and (c) percentage of phonemes correct. ICS and ICS-JC ratings showed preschoolers were always (5) to usually (4) understood across communication partners (ICS, M = 4.43; ICS-JC, M = 4.50). Both tools demonstrated excellent internal consistency (α = .91), high interrater, and test-retest reliability. Significant correlations between the two tools and between each measure and language-specific percentage of consonants correct, percentage of vowels correct, and percentage of phonemes correct provided criterion-validity evidence. A positive correlation between the ICS and age further strengthened validity evidence for that measure. Both tools show promising evidence of reliability and validity in describing functional speech intelligibility for this group of typically developing Jamaican preschoolers.
Molecular nano-arches on silicon
NASA Astrophysics Data System (ADS)
Dobrin, S.
2007-08-01
The formation of molecular nano-arches on the Si(1 1 1)-7 × 7 surface was modeled using density functional theory (DFT). It has been suggested, based on the calculations, that the arches are formed by molecular dimers of chlorobenzene at near-monolayer coverages. Molecules of the dimer are covalently bound to two silicon adatoms and to each other thereby forming a molecular arch on the surface. The structure of the molecular dimer was calculated at the B3LYP/6-31G(d) level of theory. The dimers were found to be stable at room temperature, and to form a near-monolayer coverage, which has been observed in the experiment [X.H. Chen, Q. Kong, J.C. Polanyi, D. Rogers, S. So, Surf. Sci. 340 (1995) 224; Y. Cao, J.F. Deng, G.Q. Xu, J. Chem. Phys. 112 (2000) 4759].
Sáyago-Ayerdi, Sonia G; Mateos, Raquel; Ortiz-Basurto, Rosa I; Largo, Carlota; Serrano, José; Granado-Serrano, Ana Belén; Sarriá, Beatriz; Bravo, Laura; Tabernero, María
2014-04-01
Dietary fibre (DF) obtained from Agave tequilana, which is rich in fructans and insoluble DF, and jamaica calyces (Hibiscus sabdariffa), which is rich in DF and phenolic compounds, were assessed as new potential functional ingredients using the hypercholesterolemic animal model. Wistar rats (200-250 g) were divided into 3 groups (n=8) and fed with cholesterol-rich diets supplemented with cellulose (CC, control), agave DF (ADF) or ADF with jamaica calyces (ADF-JC). After consuming the test diets for 5 weeks, weight gain in the ADF-JC group was significantly lower than in the other groups. The ADF and ADF-JC groups had a reduced concentration of cholesterol transporters in the caecum tissue, although no changes were observed in the plasma lipid profile. Both treatments improved the redox status by reducing the malondialdehyde serum levels and protein oxidative damage, compared to the CC group. DF from A. tequilana alone, or in combination with jamaica calyces, shows promising potential as a bioactive ingredient. Copyright © 2013 Elsevier Ltd. All rights reserved.
Shao, Minglong; Zhang, Xian; Rao, Zhiming; Xu, Meijuan; Yang, Taowei; Li, Hui; Xu, Zhenghong
2015-01-01
To improve the androst-1,4-diene-3,17-dione (ADD) production from phytosterol by Mycobacterium neoaurum JC-12, fructose was firstly found favorable as the initial carbon source to increase the biomass and eliminate the lag phase of M. neoaurum JC-12 in the phytosterol transformation process. Based on this phenomenon, two-stage fermentation by using fructose as the initial carbon source and feeding glucose to maintain strain metabolism was designed. By applying this strategy, the fermentation duration was decreased from 168 h to 120 h with the ADD productivity increased from 0.071 g/(L·h) to 0.108 g/(L·h). Further, three-stage fermentation by adding phytosterol to improve ADD production at the end of the two-stage fermentation was carried out and the final ADD production reached 18.6 g/L, which is the highest reported ADD production using phytosterol as substrate. Thus, this strategy provides a possible way in enhancing the ADD production in pharmaceutical industry. PMID:26352898
2002-01-01
Gessain A, Barin F, Vernant JC, Gout O, Maurs L, Calender A, de The G. Antibodies to human T-lymphotropic virus type 1 in patients with tropical spastic...association with blood transfusion. Ann Neurol 1990;28:50- 6 30. Gout O, Baulac M, Gessain A, et al. Rapid development of myelopathy after HTLV-I...uncultured cells of a patient with Sezary T-cell leukemia. Nature 1981;294:268-71. 3. Gessain A, Barin F, Vernant JC, Gout O, Maurs L, Calender A, de
Investigation of Molecular Mechanism of JC virus Viroporin Activity.
Suzuki, Tadaki
2015-01-01
Viroporins are small and hydrophobic viral proteins that form pores on host cell membranes, and their expression can increase the permeability of cellular membranes and the production of progeny virus particles. JC virus (JCV) is the causative agent of progressive multifocal leukoenchephalopathy (PML). We demonstrate that JCV Agno, which is the small and hydrophobic protein, andincreases the plasma membrane permeability and virion release, acts as a viroporin. We also demonstrate that an interaction of Agno with a host cellular protein regulates the viroporin activity of Agno. These findings indicate a new paradigm in virus-host interactions regulating viroporin activity and viral replication.
2006-09-30
Jolliff, J. K., J.C. Kindle, B. Penta, R . Arnone, Z. Lee, C. Rowley (2005), Towards an Ocean Color Data Assimilation System: Analysis of Ocean Color...and Hydrodynamic Processes, Eos Trans., AGU, 87(36), Ocean Sci. Meet. Suppl., Abstract OS53K-04 Jolliff, J.K., J.C. Kindle, B. Penta, R . Arnone, Z...WQ(N 0.10,..--------~ r ------------------, B) BOOM O.!Or---------------------------, C)NWC ··Q·41 Znm ··Q·443nm ··Q·490nm " 0 ·5 !Onm .. a ·SSSnm
2008-03-01
preparation by Ximing Tang et al. b.3. NOTCH3 /JAGGED1 pathway. Notch3 (N3) is a member of the family of Notch transmembrane receptors, which are...Prudkin L, Liu D, Tchinda J, Woods D, Behrens C, Bekele BN, Moran C, Lee C, Aster JC, Zhou B-B, Wistuba II. NOTCH3 /JAGGED1 pathway is involved in non...Behrens C, Bekele BN, Moran C, Lee C, Aster JC, Zhou B-B, Wistuba II. NOTCH3 /JAGGED1 pathway is involved in non-small cell lung cancer pathogenesis
Fermionology in the Kondo-Heisenberg model: the case of CeCoIn5
NASA Astrophysics Data System (ADS)
Zhong, Yin; Zhang, Lan; Lu, Han-Tao; Luo, Hong-Gang
2015-09-01
The Fermi surface of heavy electron systems plays a fundamental role in understanding their variety of puzzling phenomena, for example, quantum criticality, strange metal behavior, unconventional superconductivity and even enigmatic phases with yet unknown order parameters. The spectroscopy measurement of the typical heavy fermion superconductor CeCoIn5 has demonstrated multi-Fermi surface structure, which has not been studied in detail theoretically in a model system like the Kondo-Heisenberg model. In this work, we take a step toward such a theoretical model by revisiting the Kondo-Heisenberg model. It is found that the usual self-consistent calculation cannot reproduce the fermionology of the experimental observation of the system due to the sign binding between the hopping of the conduction electrons and the mean-field valence-bond order. To overcome such inconsistency, the mean-field valence-bond order is considered as a free/fitting parameter to correlate them with real-life experiments as performed in recent experiments [M.P. Allan, F. Massee, D.K. Morr, J. Van Dyke, A.W. Rost, A.P. Mackenzie, C. Petrovic, J.C. Davis, Nat. Phys. 9, 468 (2013); J. Van Dyke, F. Massee, M.P. Allan, J.C. Davis, C. Petrovic, D.K. Morr, Proc. Natl. Acad. Sci. 111, 11663 (2014)], which also explicitly reflects the intrinsic dispersion of local electrons observed in experimental measurements. Given the fermionology, the calculated effective mass enhancement, entropy, superfluid density and Knight shift are all in qualitative agreement with the experimental results of CeCoIn5, which confirms our assumption. Our result supports a d_{x^2 - y^2 }-wave pairing structure in the heavy fermion material CeCoIn5.
NASA Astrophysics Data System (ADS)
Araki, Takeshi; Hirabayashi, Izumi
2003-11-01
Large-area, uniform, high critical current density (Jc) YBa2Cu3O7-x (YBCO) superconductor films are now routinely obtained by metalorganic deposition using trifluoroacetates (TFA-MOD). This method does not require any expensive vacuum apparatus at any time during the whole process. Thus, TFA-MOD is regarded as one of the most suitable candidates for fabricating a YBCO tape for many high-power applications. This method originated from an electron beam process using BaF2 developed by Mankiewich et al. Afterwards, Gupta et al reported using TFA-MOD to prepare a similar precursor film. These two ex situ processes used fluorides instead of BaCO3 to avoid the fatal deterioration in Jc, which is caused in the resulting films through metal carboxylic groups. Fluorides not only avoid such deterioration but also lead to perfectly c-axis-oriented epitaxial crystal growth. In conventional metalorganic deposition, nucleation in the precursor film causes random orientation in the resulting film. However, in TFA-MOD, nanocrystallites in the precursor film never cause such disorder. Furthermore, during the firing process of TFA-MOD, water and HF gas diffuse quickly between the film surface and growth front of the YBCO layer. This diffusion never limits the growth rate of YBCO. What distinguishes TFA-MOD from conventional metalorganic deposition? What happens during heat treatment? In this paper, we discuss all the TFA-MOD processes and the peculiar growth scheme of the YBCO layer in TFA-MOD using the model of a quasi-liquid network. In addition, we review the history of TFA-MOD and recent results and discuss the prospects of future applications.
Fractionation of memory in medial temporal lobe amnesia.
Bird, Chris M; Shallice, Tim; Cipolotti, Lisa
2007-03-25
We report a comprehensive investigation of the anterograde memory functions of two patients with memory impairments (RH and JC). RH had neuroradiological evidence of apparently selective right-sided hippocampal damage and an intact cognitive profile apart from selective memory impairments. JC, had neuroradiological evidence of bilateral hippocampal damage following anoxia due to cardiac arrest. He had anomic and "executive" difficulties in addition to a global amnesia, suggesting atrophy extending beyond hippocampal regions. Their performance is compared with that of a previously reported hippocampal amnesic patient who showed preserved recollection and familiarity for faces in the context of severe verbal and topographical memory impairment [VC; Cipolotti, L., Bird, C., Good, T., Macmanus, D., Rudge, P., & Shallice, T. (2006). Recollection and familiarity in dense hippocampal amnesia: A case study. Neuropsychologia, 44, 489-506.] The patients were administered experimental tests using verbal (words) and two types of non-verbal materials (faces and buildings). Receiver operating characteristic analyses were used to estimate the contribution of recollection and familiarity to recognition performance on the experimental tests. RH had preserved verbal recognition memory. Interestingly, her face recognition memory was also spared, whilst topographical recognition memory was impaired. JC was impaired for all types of verbal and non-verbal materials. In both patients, deficits in recollection were invariably associated with deficits in familiarity. JC's data demonstrate the need for a comprehensive cognitive investigation in patients with apparently selective hippocampal damage following anoxia. The data from RH suggest that the right hippocampus is necessary for recollection and familiarity for topographical materials, whilst the left hippocampus is sufficient to underpin these processes for at least some types of verbal materials. Face recognition memory may be adequately subserved by areas outside of the hippocampus.
So, Eric; Hyer, Christopher F; Richardson, Marcus P; Thomas, Randall C
The journal club (JC) is a traditional part of postgraduate medical education, although little has been written on its current role in podiatric surgical training programs. The goal of the present study was to determine how JCs are conducted and the factors associated with their success. Anonymous electronic surveys were distributed to all podiatric foot and ankle surgical training program directors in the United States with a valid e-mail address. A total of 202 surveys were initially e-mailed to training program directors, with a second and third round sent to those who did not respond. The eventual response rate was 47.5%. The variables associated with success included high faculty attendance, dissemination of articles in advance, and regularly scheduled meetings. Of the residency programs that responded, 39.0% provided some type of handout or supplemental session and 39.8% provided supplemental session or handouts regarding the process of critical review, epidemiology, or biostatistics. A structured review instrument or checklist was used to guide critical appraisal in 21.5% of the JCs, and 11.8% of the programs provided feedback to residents. The JC was perceived by residency directors to be valuable and worthy of maintaining. Residency directors perceived the following factors to be associated with a successful JC: faculty participation, a designated leader, mandatory attendance, dissemination of materials in advance, and regularly scheduled meetings. Areas cited for improvement included implementation of a structured review instrument, delineation of clear goals, and periodic evaluation. We believe these findings could aid residency directors interested in maximizing the educational benefits of their JC. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.
Engineering low phorbol ester Jatropha curcas seed by intercepting casbene biosynthesis.
Li, Chunhong; Ng, Ailing; Xie, Lifen; Mao, Huizhu; Qiu, Chengxiang; Srinivasan, Ramachandran; Yin, Zhongchao; Hong, Yan
2016-01-01
Casbene is a precursor to phorbol esters and down-regulating casbene synthase effectively reduces phorbol ester biosynthesis. Seed-specific reduction of phorbol ester (PE) helps develop Jatropha seed cake for animal nutrition. Phorbol esters (PEs) are diterpenoids present in some Euphorbiaceae family members like Jatropha curcas L. (Jatropha), a tropical shrub yielding high-quality oil suitable as feedstock for biodiesel and bio jet fuel. Jatropha seed contains up to 40 % of oil and can produce oil together with cake containing high-quality proteins. However, skin-irritating and cancer-promoting PEs make Jatropha cake meal unsuitable for animal nutrition and also raise some safety and environmental concerns on its planting and processing. Two casbene synthase gene (JcCASA163 and JcCASD168) homologues were cloned from Jatropha genome and both genes were highly expressed during seed development. In vitro functional analysis proved casbene synthase activity of JcCASA163 in converting geranylgeranyl diphosphate into casbene which has been speculated to be the precursor to PEs. A seed-specific promoter driving inverted repeats for RNAi interference targeting at either JcCASA163 or both genes could effectively down-regulate casbene synthase gene expression with concurrent marked reduction of PE level (by as much as 85 %) in seeds with no pleiotropic effects observed. Such engineered low PE in seed was heritable and co-segregated with the transgene. Our work implicated casbene synthase in Jatropha PE biosynthesis and provided evidence for casbene being the precursor for PEs. The success in reducing seed PE content through down-regulation of casbene synthase demonstrates the feasibility of intercepting PE biosynthesis in Jatropha seed to help address safety concerns on Jatropha plantation and seed processing and facilitate use of its seed protein for animal nutrition.
Huo, Li-Jun; Ma, Xing-Hong; Yang, Zeng-Ming
2002-10-15
The purpose of this study was to assess sperm quality in extended boar semen during in vitro storage in order to determine which extender should be used and how long boar semen can be stored. Freshly ejaculated boar semen was diluted with equal volumes of Beltsville thaw solution (BTS), Androhep, KIEV or Zorlesco extenders and stored at 17 degrees C for up to 15 days. Sperm quality was evaluated by examining viability using SYBR-14/PI and Hoechst 33258 staining, mitochondrial activity using 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolyl-carbocyanine iodide (JC-1) staining, acrosome intactness by Coomassie blue staining, and capacitation status by chlortetracycline (CTC) staining. There were over 50% viable spermatozoa in boar semen extended with Zorlesco and Androhep extenders on Day 13 of storage. The percentage of JC-1-stained spermatozoa was 53.8 +/- 2.1% for Zorlesco and 57.7 +/- 1.60% for Androhep extenders on Day 13 of storage. The percentage of acrosome-intact spermatozoa detected by Coomassie blue staining was higher than that in the SYBR-14PI-, Hoechst 33258-, and JC-1-stained samples in our study. The results from SYBR-14/PI, Hoechst 33258, JC-1, and Coomassie blue staining were highly correlated (r > or = 0.9461). There were less than 15% capacitated spermatozoa in the semen extended with BTS, Androhep and Zorlesco extenders during 9 days of storage. However, most viable boar spermatozoa became capacitated by Day 13 of storage. The rank order of four extenders for maintaining sperm viability and mitochondrial activity was as follows: Androhep, Zorlesco, BTS, KIEV.
A new shielding calculation method for X-ray computed tomography regarding scattered radiation.
Watanabe, Hiroshi; Noto, Kimiya; Shohji, Tomokazu; Ogawa, Yasuyoshi; Fujibuchi, Toshioh; Yamaguchi, Ichiro; Hiraki, Hitoshi; Kida, Tetsuo; Sasanuma, Kazutoshi; Katsunuma, Yasushi; Nakano, Takurou; Horitsugi, Genki; Hosono, Makoto
2017-06-01
The goal of this study is to develop a more appropriate shielding calculation method for computed tomography (CT) in comparison with the Japanese conventional (JC) method and the National Council on Radiation Protection and Measurements (NCRP)-dose length product (DLP) method. Scattered dose distributions were measured in a CT room with 18 scanners (16 scanners in the case of the JC method) for one week during routine clinical use. The radiation doses were calculated for the same period using the JC and NCRP-DLP methods. The mean (NCRP-DLP-calculated dose)/(measured dose) ratios in each direction ranged from 1.7 ± 0.6 to 55 ± 24 (mean ± standard deviation). The NCRP-DLP method underestimated the dose at 3.4% in fewer shielding directions without the gantry and a subject, and the minimum (NCRP-DLP-calculated dose)/(measured dose) ratio was 0.6. The reduction factors were 0.036 ± 0.014 and 0.24 ± 0.061 for the gantry and couch directions, respectively. The (JC-calculated dose)/(measured dose) ratios ranged from 11 ± 8.7 to 404 ± 340. The air kerma scatter factor κ is expected to be twice as high as that calculated with the NCRP-DLP method and the reduction factors are expected to be 0.1 and 0.4 for the gantry and couch directions, respectively. We, therefore, propose a more appropriate method, the Japanese-DLP method, which resolves the issues of possible underestimation of the scattered radiation and overestimation of the reduction factors in the gantry and couch directions.
2010-12-01
6 ]. Shot peening is a cold working process in which the surface of the 4 Approved for public release; distribution unlimited...for the ZA Model Parameter Value σa 945.1961MPa B 246.6467MPa β0 1.1636×10− 6 β1 0.1065 B0 1481.249 MPa εr 0.0538 α0 10− 6 α1 3.1564×10− 4 Figures 15 and...16 show the strain rate dependence curves at different strains for the JC and ZA models. 10 − 6 10 − 4 10 −2 10 0 10 2 10 4 10 6 1000 1100 1200
Quasipermanent magnets of high temperature superconductor - Temperature dependence
NASA Technical Reports Server (NTRS)
Chen, In-Gann; Liu, Jianxiong; Ren, Yanru; Weinstein, Roy; Kozlowski, Gregory; Oberly, Charles E.
1993-01-01
We report on persistent field in quasi-permanent magnets of high temperature superconductors. Magnets composed of irradiated Y(1+)Ba2Cu3O7 trapped field Bt = 1.52 T at 77 K and 1.9 T at lower temperature. However, the activation magnet limited Bt at lower temperature. We present data on Jc(H,T) for unirradiated materials, and calculate Bt at various T. Based upon data at 65 K, we calculate Bt in unirradiated single grains at 20 K and find that 5.2 T will be trapped for grain diameter d about 1.2 cm, and 7.9 T for d = 2.3 cm. Irradiated grains will trap four times these values.
Rodrigues, Marília Danyelle Nunes; Seminotti, Bianca; Zanatta, Ângela; de Mello Gonçalves, Aline; Bellaver, Bruna; Amaral, Alexandre Umpierrez; Quincozes-Santos, André; Goodman, Stephen Irwin; Woontner, Michael; Souza, Diogo Onofre; Wajner, Moacir
2017-08-01
Patients affected by glutaric aciduria type I (GA-I) show progressive cortical leukoencephalopathy whose pathogenesis is poorly known. In the present work, we exposed cortical astrocytes of wild-type (Gcdh +/+ ) and glutaryl-CoA dehydrogenase knockout (Gcdh -/- ) mice to the oxidative stress inducer menadione and measured mitochondrial bioenergetics, redox homeostasis, and cell viability. Mitochondrial function (MTT and JC1-mitochondrial membrane potential assays), redox homeostasis (DCFH oxidation, nitrate and nitrite production, GSH concentrations and activities of the antioxidant enzymes SOD and GPx), and cell death (propidium iodide incorporation) were evaluated in primary cortical astrocyte cultures of Gcdh +/+ and Gcdh -/- mice unstimulated and stimulated by menadione. We also measured the pro-inflammatory response (TNFα levels, IL1-β and NF-ƙB) in unstimulated astrocytes obtained from these mice. Gcdh -/- mice astrocytes were more vulnerable to menadione-induced oxidative stress (decreased GSH concentrations and altered activities of the antioxidant enzymes), mitochondrial dysfunction (decrease of MTT reduction and JC1 values), and cell death as compared with Gcdh +/+ astrocytes. A higher inflammatory response (TNFα, IL1-β and NF-ƙB) was also observed in Gcdh -/- mice astrocytes. These data indicate a higher susceptibility of Gcdh -/- cortical astrocytes to oxidative stress and mitochondrial dysfunction, probably leading to cell death. It is presumed that these pathomechanisms may contribute to the cortical leukodystrophy observed in GA-I patients.
NASA Astrophysics Data System (ADS)
Gafarov, Ozarfar; Gapud, Albert A.; Moraes, Sunhee; Thompson, James R.; Christen, David K.; Reyes, Arneil P.
2011-03-01
Results of recent measurements on two very clean, single-crystal samples of the A15 superconductor V3 Si are presented. Magnetization and transport data confirm the ``clean'' quality of both samples, as manifested by: (i) high residual resistivity ratio, (ii) low critical current densities, and (iii) a ``peak'' effect in the field dependence of critical current. The (H,T) phase line for this peak effect is shifted in the slightly ``dirtier'' sample, which also has higher critical current density Jc (H). High-current Lorentz forces are applied on mixed-state vortices in order to induce the highly ordered free flux flow (FFF) phase, using the same methods as in previous work. A traditional model by Bardeen and Stephen (BS) predicts a simple field dependence of flux flow resistivity ρf (H), presuming a field-independent flux core size. A model by Kogan and Zelezhina (KZ) takes core size into account, and predicts a deviation from BS. In this study, ρf (H) is confirmed to be consistent with predictions of KZ, as will be discussed. Funded by Research Corporation and the National Science Foundation.
Li, G. Z.; Sumption, M. D.; Collings, E. W.
2015-01-01
Significantly enhanced critical current density (Jc) for MgB2 superconducting wires can be obtained following the advanced internal Mg infiltration (AIMI) route. But unless suitable precautions are taken, the AIMI-processed MgB2 wires will exhibit incomplete MgB2 layer formation, i.e. reduced superconductor core size and hence suppressed current-carrying capability. Microstructural characterization of AIMI MgB2 wires before and after the heat treatment reveals that the reaction mechanism changes from a “Mg infiltration-reaction” at the beginning of the heat treatment to a “Mg diffusion-reaction” once a dense MgB2 layer is formed. A drastic drop in the Mg transport rate from infiltration to diffusion causes the termination of the MgB2 core growth. To quantify this process, a two-stage kinetic model is built to describe the MgB2 layer formation and growth. The derived kinetic model and the associated experimental observations indicate that fully reacted AIMI-processed MgB2 wires can be achieved following the optimization of B particle size, B powder packing density, MgB2 reaction activation energy and its response to the additions of dopants. PMID:26973431
NASA Astrophysics Data System (ADS)
Sparing, M.; Reich, E.; Hänisch, J.; Gottschall, T.; Hühne, R.; Fähler, S.; Rellinghaus, B.; Schultz, L.; Holzapfel, B.
2017-10-01
The critical current density {J}{{c}} in {{YBa}}2{{Cu}}3{{{O}}}7-δ thin films, which limits their application in external magnetic fields, can be enhanced by the introduction of artificial pinning centers such as non-superconducting nanoparticles inducing additional defects and local strain in the superconducting matrix. To understand the correlation between superconductivity, defect structures and particles, a controlled integration of particles with adjustable properties is essential. A powerful technique for the growth of isolated nanoparticles in the range of 10 nm is dc-magnetron sputtering in an inert gas flow. The inert gas condensation (IGC) of particles allows for an independent control of both the particle diameter distribution and the areal density. We report on the integration of such gas-phase-condensed {{HfO}}2 nanoparticles into pulsed laser deposited (PLD) {{YBa}}2{{Cu}}3{{{O}}}7-δ thin film multilayers with a combined PLD-IGC system. The particles and the structure of the multilayers are analyzed by transmission electron microscopy on cross-sectional FIB lamellae. As a result of the IGC particle implementation, randomly as well as biaxially oriented {{BaHfO}}3 precipitates are formed in the {{YBa}}2{{Cu}}3{{{O}}}7-δ thin films. With as few as three interlayers of nanoparticles, the pinning force density is enhanced in the low-field region.
1993-12-06
CAH.,)’Il]iCl• i. AUTHOR(S) Ceceli A. Duchi, M. Kanskar, J.C. Wu, M.N. WYbourne, Sui Xiong Cai, Hingdi Yan, and John F. W. Keana PERFORMING...13 < Eugene, OR 97403 1 M- Attn: John F. W. Keana* and Martin N. Wybjurne** SPONSORINGIMONITORING AGENCY NAME(S) AND AODRESS(ES) 10...M. Kanskart, J.C. Wut , M.N. Wybourne, Sui Xiong Cail, Mingdi Yan’, and John F.W. Keanaý Department of Physicst and Chemistry*, University of Oregon
Beppu, Minako; Kawamoto, Michi; Nukuzuma, Souichi; Kohara, Nobuo
2012-01-01
We describe a case of a 67-year-old man with systemic lupus erythematosus who presented with progressive left hemiplegia. Although the cerebral spinal fluid (CSF) polymerase chain reaction (PCR) for the JC virus was negative, a brain biopsy confirmed the diagnosis of progressive multifocal leukoencephalopathy (PML). The tapering of prednisone and the use of cidofovir could not arrest the disease progression. Administration of mefloquine stopped the extension of the lesion, and resulted in obvious clinical improvement. The CSF nested PCR for the JC virus also became negative. This widely used drug should be tried for the treatment of non-HIV PML.
Impact erosion prediction using the finite volume particle method with improved constitutive models
NASA Astrophysics Data System (ADS)
Leguizamón, Sebastián; Jahanbakhsh, Ebrahim; Maertens, Audrey; Vessaz, Christian; Alimirzazadeh, Siamak; Avellan, François
2016-11-01
Erosion damage in hydraulic turbines is a common problem caused by the high- velocity impact of small particles entrained in the fluid. In this investigation, the Finite Volume Particle Method is used to simulate the three-dimensional impact of rigid spherical particles on a metallic surface. Three different constitutive models are compared: the linear strainhardening (L-H), Cowper-Symonds (C-S) and Johnson-Cook (J-C) models. They are assessed in terms of the predicted erosion rate and its dependence on impact angle and velocity, as compared to experimental data. It has been shown that a model accounting for strain rate is necessary, since the response of the material is significantly tougher at the very high strain rate regime caused by impacts. High sensitivity to the friction coefficient, which models the cutting wear mechanism, has been noticed. The J-C damage model also shows a high sensitivity to the parameter related to triaxiality, whose calibration appears to be scale-dependent, not exclusively material-determined. After calibration, the J-C model is capable of capturing the material's erosion response to both impact velocity and angle, whereas both C-S and L-H fail.
Development of marker-free transgenic Jatropha plants with increased levels of seed oleic acid
2012-01-01
Background Jatropha curcas is recognized as a new energy crop due to the presence of the high amount of oil in its seeds that can be converted into biodiesel. The quality and performance of the biodiesel depends on the chemical composition of the fatty acids present in the oil. The fatty acids profile of the oil has a direct impact on ignition quality, heat of combustion and oxidative stability. An ideal biodiesel composition should have more monounsaturated fatty acids and less polyunsaturated acids. Jatropha seed oil contains 30% to 50% polyunsaturated fatty acids (mainly linoleic acid) which negatively impacts the oxidative stability and causes high rate of nitrogen oxides emission. Results The enzyme 1-acyl-2-oleoyl-sn-glycero-3-phosphocholine delta 12-desaturase (FAD2) is the key enzyme responsible for the production of linoleic acid in plants. We identified three putative delta 12 fatty acid desaturase genes in Jatropha (JcFAD2s) through genome-wide analysis and downregulated the expression of one of these genes, JcFAD2-1, in a seed-specific manner by RNA interference technology. The resulting JcFAD2-1 RNA interference transgenic plants showed a dramatic increase of oleic acid (> 78%) and a corresponding reduction in polyunsaturated fatty acids (< 3%) in its seed oil. The control Jatropha had around 37% oleic acid and 41% polyunsaturated fatty acids. This indicates that FAD2-1 is the major enzyme responsible for converting oleic acid to linoleic acid in Jatropha. Due to the changes in the fatty acids profile, the oil of the JcFAD2-1 RNA interference seed was estimated to yield a cetane number as high as 60.2, which is similar to the required cetane number for conventional premium diesel fuels (60) in Europe. The presence of high seed oleic acid did not have a negative impact on other Jatropha agronomic traits based on our preliminary data of the original plants under greenhouse conditions. Further, we developed a marker-free system to generate the transgenic Jatropha that will help reduce public concerns for environmental issues surrounding genetically modified plants. Conclusion In this study we produced seed-specific JcFAD2-1 RNA interference transgenic Jatropha without a selectable marker. We successfully increased the proportion of oleic acid versus linoleic in Jatropha through genetic engineering, enhancing the quality of its oil. PMID:22377043
Asami, Tatsuya; Katayama, Hiroyuki; Torrey, Jason Robert; Visvanathan, Chettiyappan; Furumai, Hiroaki
2016-09-15
In order to properly assess and manage the risk of infection by enteric viruses in tap water, virus removal efficiency should be evaluated quantitatively for individual processes in actual drinking water treatment plants (DWTPs); however, there have been only a few studies due to technical difficulties in quantifying low virus concentration in water samples. In this study, the removal efficiency of indigenous viruses was evaluated for coagulation-sedimentation (CS) and rapid sand filtration (RSF) processes in a DWTP in Bangkok, Thailand by measuring the concentration of viruses before and after treatment processes using real-time polymerase chain reaction (qPCR). Water samples were collected and concentrated from raw source water, after CS, and after RSF, and inhibitory substances in water samples were reduced by use of a hydrophobic resin (DAX-8). Pepper mild mottle virus (PMMoV) and JC polyomavirus (JC PyV) were found to be highly prevalent in raw waters, with concentrations of 10(2.88 ± 0.35) and 10(3.06 ± 0.42) copies/L (geometric mean ± S.D.), respectively. Step-wise removal efficiencies were calculated for individual processes, with some variation observed between wet and dry seasons. During the wet season, PMMoV was removed less by CS and more by RSF on average (0.40 log10 vs 1.26 log10, respectively), while the reverse was true for JC PyV (1.91 log10 vs 0.49 log10, respectively). Both viruses were removed similarly during the dry season, with CS removing the most virus (PMMoV, 1.61 log10 and 0.78 log10; JC PyV, 1.70 log10, and 0.59 log10; CS and RSF, respectively). These differences between seasons were potentially due to variations in raw water quality and the characteristics of the viruses themselves. These results suggest that PMMoV and JC PyV, which are more prevalent in environmental waters than the other enteric viruses evaluated in this study, could be useful in determining viral fate for the risk management of viruses in water treatment processes in actual full-scale DWTPs. Copyright © 2016. Published by Elsevier Ltd.
Barron, John A.; Bukry, David; Dean, Walter E.; Addison, Jason A.; Finney, Bruce
2009-01-01
High-resolution records of diatoms, silicoflagellates, and geochemistry covering the past 15,000 years were studied in three cores from the Gulf of Alaska (GOA). Core EW0408-85JC in an oceanic setting on the Kayak Slope displays a paleoceanographic record similar to that at several locations on the California margin during deglaciation. Biologic productivity as reconstructed using geochemical and microfossil proxies increased abruptly during the Bølling–Alleröd (Bø–Al) warm interval (14.7–12.9 cal ka), declined during the Younger Dryas (YD) cold interval (12.9 to 11.7 cal kyr BP), and rose again during the earliest Holocene. At this site, the record after ~ 11 cal kyr BP is dominated by oceanic diatoms and silicoflagellates, with geochemical proxies displaying more subtle variation. Cores EW0408-66JC in the Yakobi Sea Valley near Cross Sound and EW0408-11JC in the Gulf of Esquibel contain an expanded, composite record along the southeast Alaskan margin. Core 66JC contains a detailed record of the Bø–Al and YD. Diatoms and silicoflagellates indicate that coastal upwelling and biosiliceous productivity were strong during the Bø–Al but declined during the YD. Sea ice-related diatoms increased in abundance during the YD, indicating cooler, but less productive waters. The glacial to biogenic marine sediment transition in core 11JC occurs at 1280 cmbsf (centimeters below sea floor), probably representing rising sea level and deglaciation early in the Bø–Al. Freshwater and sea-ice related diatoms are common in the lower part of the core (Bø–Al and YD), but upwelling-related diatoms and silicoflagellates quickly increased in relative abundance up-core, dominating the record of the past 11,000 years. Low oxygen conditions in the bottom water as reconstructed using geochemical proxies (U and Mo concentration) were most intense between ~ 6.5 and 2.8 cal kyr BP, the beginning of which is coincident with increases in abundance of upwelling-related diatoms. The records from these three cores jointly thus made it possible to reconstruct paleoclimatic and paleoceanographic conditions at high northern Pacific latitudes during the last 15 kyr.
Block copolymer self-assembly–directed synthesis of mesoporous gyroidal superconductors
Robbins, Spencer W.; Beaucage, Peter A.; Sai, Hiroaki; Tan, Kwan Wee; Werner, Jörg G.; Sethna, James P.; DiSalvo, Francis J.; Gruner, Sol M.; Van Dover, Robert B.; Wiesner, Ulrich
2016-01-01
Superconductors with periodically ordered mesoporous structures are expected to have properties very different from those of their bulk counterparts. Systematic studies of such phenomena to date are sparse, however, because of a lack of versatile synthetic approaches to such materials. We demonstrate the formation of three-dimensionally continuous gyroidal mesoporous niobium nitride (NbN) superconductors from chiral ABC triblock terpolymer self-assembly–directed sol-gel–derived niobium oxide with subsequent thermal processing in air and ammonia gas. Superconducting materials exhibit a critical temperature (Tc) of about 7 to 8 K, a flux exclusion of about 5% compared to a dense NbN solid, and an estimated critical current density (Jc) of 440 A cm−2 at 100 Oe and 2.5 K. We expect block copolymer self-assembly–directed mesoporous superconductors to provide interesting subjects for mesostructure-superconductivity correlation studies. PMID:27152327
NASA Astrophysics Data System (ADS)
Aytug, T.; Paranthaman, M.; Kang, B. W.; Sathyamurthy, S.; Goyal, A.; Christen, D. K.
2001-10-01
Coated conductor applications in power technologies require stabilization of the high-temperature superconducting (HTS) layers against thermal runaway. Conductive La0.7Sr0.3MnO3 (LSMO) has been epitaxially grown on biaxially textured Ni substrates as a single buffer layer. The subsequent epitaxial growth of YBa2Cu3O7-δ (YBCO) coatings by pulsed laser deposition yielded self-field critical current densities (Jc) of 0.5×106A/cm2 at 77 K, and provided good electrical connectivity over the entire structure (HTS+conductive-buffer+metal substrate). Property characterizations of YBCO/LSMO/Ni architecture revealed excellent crystallographic and morphological properties. These results have demonstrated that LSMO, used as a single, conductive buffer layer, may offer potential for use in fully stabilized YBCO coated conductors.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rabe, Craig D.; Nelson, Douglas D.
The Nez Perce Tribe Johnson Creek Artificial Propagation Enhancement Project (JCAPE) has conducted juvenile and adult monitoring and evaluation studies for its 10th consecutive year. Completion of adult and juvenile Chinook salmon studies were conducted for the purpose of evaluating a small-scale production initiative designed to increase the survival of a weak but recoverable spawning aggregate of summer Chinook salmon Oncorhynchus tshawytscha. The JCAPE program evaluates the life cycle of natural origin (NOR) and hatchery origin (HOR) supplementation fish to quantify the key performance measures: abundance, survival-productivity, distribution, genetics, life history, habitat, and in-hatchery metrics. Operation of a picket stylemore » weir and intensive multiple spawning ground surveys were completed to monitor adult Chinook salmon and a rotary screw trap was used to monitor migrating juvenile Chinook salmon in Johnson Creek. In 2007, spawning ground surveys were conducted on all available spawning habitat in Johnson Creek and one of its tributaries. A total of 63 redds were observed in the index reach and 11 redds for all other reaches for a combined count of 74 redds. Utilization of carcass recovery surveys and adult captures at an adult picket weir yielded a total estimated adult escapement to Johnson Creek of 438 Chinook salmon. Upon deducting fish removed for broodstock (n=52), weir mortality/ known strays (n=12), and prespawning mortality (n=15), an estimated 359 summer Chinook salmon were available to spawn. Estimated total migration of brood year 2005 NOR juvenile Chinook salmon at the rotary screw trap was calculated for three seasons (summer, fall, and spring). The total estimated migration was 34,194 fish; 26,671 of the NOR migrants left in the summer (July 1 to August 31, 2005) as fry/parr, 5,852 left in the fall (September 1 to November 21, 2005) as presmolt, and only 1,671 NOR fish left in the spring (March 1 to June 30, 2006) as smolt. In addition, there were 120,415 HOR supplementation smolts released into Johnson Creek during the week of March 12, 2007. Life stage-specific juvenile survival from Johnson Creek to Lower Granite and McNary dams was calculated for brood year 2005 NOR and HOR supplementation juvenile Chinook salmon. Survival of NOR parr Chinook salmon migrating from Johnson Creek to Lower Granite and McNary dams was 28.2% and 16.2%. Survival of NOR presmolt Chinook salmon migrating from Johnson Creek to Lower Granite and McNary dams was 28.2% and 22.3%. Survival of NOR smolt Chinook salmon migrating from Johnson Creek to Lower Granite and McNary dams was 44.7% and 32.9%. Survival of HOR smolt Chinook salmon migrating from Johnson Creek to Lower Granite and McNary dams was 31.9% and 26.2%. Multi-year analysis on smolt to adult return rate's (SAR's) and progeny to parent ratio's (P:P's) were calculated for NOR and HOR supplementation Brood Year 2002 Chinook salmon. SAR's were calculated from Johnson Creek to Johnson Creek (JC to JC), Lower Granite Dam to Lower Granite (LGD to LGD), and Lower Granite Dam to Johnson Creek (LGD to JC); for NOR fish SAR's were 0.16%, 1.16% and 1.12%, while HOR supplementation SAR's from JC to JC, LGD to LGD and LGD to JC were 0.04%, 0.19% and 0.13%. P:P's for all returning NOR and HOR supplemented adults were under replacement levels at 0.13 and 0.65, respectively. Recruit per spawner estimates (R/S) for Brood Year 2005 adult Chinook salmon were also calculated for NOR and HOR supplemented Chinook salmon at JC and LGD. R/S estimates for NOR and HOR supplemented fish at JC were 231 and 1,745, while R/S estimates at LGD were 67 and 557. Management recommendations address (1) effectiveness of data collection methods, (2) sufficiency of data quality (statistical power) to enable management recommendations, (3) removal of uncertainty and subsequent cessation of M&E activities, and (4) sufficiency of findings for program modifications prior to five-year review.« less
NASA Astrophysics Data System (ADS)
Iwai, Sadanori; Miyazaki, Hiroshi; Tosaka, Taizo; Tasaki, Kenji; Urata, Masami; Ioka, Shigeru; Ishii, Yusuke
2013-11-01
We have been developing a conduction-cooled coil wound with YBCO-coated conductors for HTS applications. Previously, we have fabricated a coil composed of a stack of 12 single pancakes wound with 4 mm-wide YBCO tapes. This coil had a central magnetic field as high as 5.1 T at 10 K under conduction-cooled conditions. In the present study, we fabricated and tested a coil composed of a stack of four single pancakes wound with 12 mm-wide YBCO tapes. The total size of the coil and the Jc value of the tapes were almost the same as those of the former coil. At 77 K, the voltage-current characteristics showed a high n-value of 24, confirming that the coil had no degradation. Furthermore, in a conduction-cooled configuration at 20 K to 60 K, the coil showed a high n-value of over 20. At 20 K, the central magnetic field reached 5.9 T at 903 A, which is 1.3-times higher than that of the former coil.
Diabetic neuropathy; Diabetes - neuropathy; Diabetes - peripheral neuropathy ... pubmed/27979897 . Boulton AJM, Malik RA. Diabetes mellitus: ... of peripheral nerves. In: Daroff RB, Jankovic J, Mazziotta JC, ...
Campbell penetration depth in Fe-based superconductors
DOE Office of Scientific and Technical Information (OSTI.GOV)
Prommapan, Plegchart
A 'true' critical current density, j c, as opposite to commonly measured relaxed persistent (Bean) current, j B, was extracted from the Campbell penetration depth, Λ c(T,H) measured in single crystals of LiFeAs, and optimally electron-doped Ba(Fe 0.954Ni 0.046) 2As 2 (FeNi122). In LiFeAs, the effective pinning potential is nonparabolic, which follows from the magnetic field - dependent Labusch parameter α. At the equilibrium (upon field - cooling), α(H) is non-monotonic, but it is monotonic at a finite gradient of the vortex density. This behavior leads to a faster magnetic relaxation at the lower fields and provides a natural dynamicmore » explanation for the fishtail (second peak) effect. We also find the evidence for strong pinning at the lower fields.The inferred field dependence of the pinning potential is consistent with the evolution from strong pinning, through collective pinning, and eventually to a disordered vortex lattice. The value of jc(2 K) ≅ 1.22 x 10 6 A/cm 2 provide an upper estimate of the current carrying capability of LiFeAs. Overall, vortex behavior of almost isotropic, fully-gapped LiFeAs is very similar to highly anisotropic d-wave cuprate superconductors, the similarity that requires further studies in order to understand unconventional superconductivity in cuprates and pnictides. In addition to LiFeAs, we also report the magnetic penetration depth in BaFe 2As 2 based superconductors including irradiation of FeNi122. In unirradiated FeNi122, the maximum critical current value is, j c(2K) ≅ 3.3 x 10 6 A/cm 2. The magnetic-dependent feature was observed near the transition temperature in FeTe 0.53Se 0.47 and irradiated FeNi122. Because of this feature, further studies are required in order to properly calibrate the Campbell penetration depth. Finally, we detected the crossing between the magnetic penetration depth and London penetration depth in optimally hold-doped Ba 0.6K 0.4Fe 2As 2 (BaK122) and isovalent doped BaFe 2(As 0.7P 0.3) 2 (BaP122). These phenomena probably coincide with anomalous Meissner effect reported in pnicitde superconductors [Prozorov et al. (2010b)] however more studies are needed in order to clarify this.« less
A giant outburst two years before the core-collapse of a massive star.
Pastorello, A; Smartt, S J; Mattila, S; Eldridge, J J; Young, D; Itagaki, K; Yamaoka, H; Navasardyan, H; Valenti, S; Patat, F; Agnoletto, I; Augusteijn, T; Benetti, S; Cappellaro, E; Boles, T; Bonnet-Bidaud, J-M; Botticella, M T; Bufano, F; Cao, C; Deng, J; Dennefeld, M; Elias-Rosa, N; Harutyunyan, A; Keenan, F P; Iijima, T; Lorenzi, V; Mazzali, P A; Meng, X; Nakano, S; Nielsen, T B; Smoker, J V; Stanishev, V; Turatto, M; Xu, D; Zampieri, L
2007-06-14
The death of massive stars produces a variety of supernovae, which are linked to the structure of the exploding stars. The detection of several precursor stars of type II supernovae has been reported (see, for example, ref. 3), but we do not yet have direct information on the progenitors of the hydrogen-deficient type Ib and Ic supernovae. Here we report that the peculiar type Ib supernova SN 2006jc is spatially coincident with a bright optical transient that occurred in 2004. Spectroscopic and photometric monitoring of the supernova leads us to suggest that the progenitor was a carbon-oxygen Wolf-Rayet star embedded within a helium-rich circumstellar medium. There are different possible explanations for this pre-explosion transient. It appears similar to the giant outbursts of luminous blue variable stars (LBVs) of 60-100 solar masses, but the progenitor of SN 2006jc was helium- and hydrogen-deficient (unlike LBVs). An LBV-like outburst of a Wolf-Rayet star could be invoked, but this would be the first observational evidence of such a phenomenon. Alternatively, a massive binary system composed of an LBV that erupted in 2004, and a Wolf-Rayet star exploding as SN 2006jc, could explain the observations.
Wideband-Switchable Metamaterial Absorber Using Injected Liquid Metal.
Kim, Hyung Ki; Lee, Dongju; Lim, Sungjoon
2016-08-22
Metamaterial absorbers can provide good solutions for radar-cross-section (RCS) reduction. In spite of their attractive features of thinness, lightness, and low cost, resonant metamaterial absorbers have a drawback of narrow bandwidth. For practical radar applications, wideband absorbers are necessary. In this paper, we propose a wideband-switchable metamaterial absorber using liquid metal. In order to reduce RCS both for X-band and C-band, the switchable Jerusalem cross (JC) resonator is introduced. The JC resonator consists of slotted circular rings, chip resistors, and microfluidic channels. The JC resonator is etched on a flexible printed circuit board (FPCB), and the microfluidic channels are laser-etched on a polydimethylsiloxane (PDMS) material. The proposed absorber can switch the absorption frequency band by injecting a liquid metal alloy into the channels. The performance of the absorber was demonstrated through full-wave simulation and through measurements employing prototypes. The experimental results showed absorption ratios of over 90% from 7.43 GHz to 14.34 GHz, and from 5.62 GHz to 7.3 GHz, with empty channels and liquid metal-filled channels, respectively. Therefore, the absorption band was successfully switched between the C-band (4-8 GHz) and the X-band (8-12 GHz) by injecting liquid metal eutectic gallium indium alloy (EGaIn) into the channels.
Wideband-Switchable Metamaterial Absorber Using Injected Liquid Metal
NASA Astrophysics Data System (ADS)
Kim, Hyung Ki; Lee, Dongju; Lim, Sungjoon
2016-08-01
Metamaterial absorbers can provide good solutions for radar-cross-section (RCS) reduction. In spite of their attractive features of thinness, lightness, and low cost, resonant metamaterial absorbers have a drawback of narrow bandwidth. For practical radar applications, wideband absorbers are necessary. In this paper, we propose a wideband-switchable metamaterial absorber using liquid metal. In order to reduce RCS both for X-band and C-band, the switchable Jerusalem cross (JC) resonator is introduced. The JC resonator consists of slotted circular rings, chip resistors, and microfluidic channels. The JC resonator is etched on a flexible printed circuit board (FPCB), and the microfluidic channels are laser-etched on a polydimethylsiloxane (PDMS) material. The proposed absorber can switch the absorption frequency band by injecting a liquid metal alloy into the channels. The performance of the absorber was demonstrated through full-wave simulation and through measurements employing prototypes. The experimental results showed absorption ratios of over 90% from 7.43 GHz to 14.34 GHz, and from 5.62 GHz to 7.3 GHz, with empty channels and liquid metal-filled channels, respectively. Therefore, the absorption band was successfully switched between the C-band (4-8 GHz) and the X-band (8-12 GHz) by injecting liquid metal eutectic gallium indium alloy (EGaIn) into the channels.
Akhund, Saima; Kadir, Muhammad Masood
2006-08-22
Journal clubs are an internationally recognized teaching tool in many postgraduate medical education fields. In developing countries lack of funds for current print materials may have limited journal club use. But with advancing information technology trainees in developing countries increasingly have more access to high quality journals online. However, we are aware of no studies describing journal club existence and effectiveness in postgraduate medical training in Pakistan. Also we have found no published effectiveness studies of this teaching modality in Community Medicine (Public Health) in any country. This study evaluated the effectiveness of Community Medicine (Public Health) Resident Journal Club (CMR-JC) in Aga Khan University, Pakistan using international criteria for successful journal clubs (2 years continuous existence and more than 50% attendance) and examining resident and alumni satisfaction. Journal club effectiveness criteria were searched using electronic search databases. Departmental records were reviewed from September 1999-September 2005. Ninety percent of residents and alumni of Community Medicine Residency Programme participated voluntarily in a confidential survey. The CMR-JC was regularly conducted. More than 95% of residents attended. (Total residents in the CMR-Programme: 32). Twenty-seven out of 29 current residents/alumni responded to the anonymous questionnaire. Acquisition of critical appraisal skills (23 respondents) and keeping up with current literature (18 respondents) were the two most important objectives achieved. Respondents recommended improved faculty participation and incorporating a structured checklist for article review. CMR-JC fulfils criteria for effective journal clubs. Residents and alumni agree CMR-JC meets its objectives. Incorporating suggested recommendations will further improve standards. The journal club learning modality should be included in residency training programs in developing countries. Effective use of online resources to support journal clubs is demonstrated as a successful alternative to excessive expenditure for obtaining print journals. Those trying to start or improve journal clubs can benefit from our experience.
Sánchez-Mendiola, Melchor; Morales-Castillo, Daniel; Torruco-García, Uri; Varela-Ruiz, Margarita
2015-12-14
A time-honored strategy for keeping up to date in medicine and improving critical appraisal skills is the Journal Club (JC). There are several reports of its use in medicine and allied health sciences but almost no reports of JC focused on medical education. The purpose of the study is to describe and evaluate an eight years' experience with a medical education Journal Club (MEJC). We started a monthly medical education JC in 2006 at UNAM Faculty of Medicine in Mexico City. Its goal is to provide faculty with continuing professional development in medical education. A discussion guide and a published paper were sent 2 weeks before sessions. We reviewed the themes and publication types of the papers used in the sessions, and in June-July 2014 administered a retrospective post-then-pre evaluation questionnaire to current participants that had been regular attendees to the JC for more than 2 years. The retrospective post-then-pre comparisons were analyzed with Wilcoxon signed-rank test. Effect sizes were calculated for the pre-post comparisons with Cohen's r. There have been 94 MEJC sessions until July 2014. Average attendance is 20 persons, a mix of clinicians, educators, psychologists and a sociologist. The articles were published in 32 different journals, and covered several medical education themes (curriculum, faculty development, educational research methodology, learning methods, assessment, residency education). 22 Attendees answered the evaluation instrument. The MEJC had a positive evaluation from good to excellent, and there was an improvement in self-reported competencies in medical education literature critical appraisal and behaviors related to the use of evidence in educational practice, with a median effect size higher than 0.5. The evaluation instrument had a Cronbach's alpha of 0.96. A periodic Medical Education Journal Club can improve critical appraisal of the literature, and be maintained long-term using evidence-based strategies. This activity is a useful adjunct to the scholarship of teaching.
Akhund, Saima; Kadir, Muhammad Masood
2006-01-01
Background Journal clubs are an internationally recognized teaching tool in many postgraduate medical education fields. In developing countries lack of funds for current print materials may have limited journal club use. But with advancing information technology trainees in developing countries increasingly have more access to high quality journals online. However, we are aware of no studies describing journal club existence and effectiveness in postgraduate medical training in Pakistan. Also we have found no published effectiveness studies of this teaching modality in Community Medicine (Public Health) in any country. This study evaluated the effectiveness of Community Medicine (Public Health) Resident Journal Club (CMR-JC) in Aga Khan University, Pakistan using international criteria for successful journal clubs (2 years continuous existence and more than 50% attendance) and examining resident and alumni satisfaction. Methods Journal club effectiveness criteria were searched using electronic search databases. Departmental records were reviewed from September1999–September 2005. Ninety percent of residents and alumni of Community Medicine Residency Programme participated voluntarily in a confidential survey. Results The CMR-JC was regularly conducted. More than 95% of residents attended. (Total residents in the CMR-Programme: 32). Twenty-seven out of 29 current residents/alumni responded to the anonymous questionnaire. Acquisition of critical appraisal skills (23 respondents) and keeping up with current literature (18 respondents) were the two most important objectives achieved. Respondents recommended improved faculty participation and incorporating a structured checklist for article review. Conclusion CMR-JC fulfils criteria for effective journal clubs. Residents and alumni agree CMR-JC meets its objectives. Incorporating suggested recommendations will further improve standards. The journal club learning modality should be included in residency training programs in developing countries. Effective use of online resources to support journal clubs is demonstrated as a successful alternative to excessive expenditure for obtaining print journals. Those trying to start or improve journal clubs can benefit from our experience. PMID:16925800
Changes to anti-JCV antibody levels in a Swedish national MS cohort
Warnke, Clemens; Ramanujam, Ryan; Plavina, Tatiana; Bergström, Tomas; Goelz, Susan; Subramanyam, Meena; Kockum, Ingrid; Rahbar, Afsar; Kieseier, Bernd C; Holmén, Carolina; Olsson, Tomas; Hillert, Jan; Fogdell-Hahn, Anna
2013-01-01
Background The anti-JC virus (JCV) antibody status has been introduced to stratify patients with multiple sclerosis (MS) for higher or lower risk of progressive multifocal leukoencephalopathy (PML). Objective To assess the potential utility of anti-JCV antibody levels for earlier diagnosis or prediction of PML. Methods An analytically validated antibody assay was used to determine serological status, normalised optical density values, and dilution titres for anti-JCV antibodies. The method was applied to stored sera of 1157 patients with MS including five cases of PML, all enrolled in the Swedish pharmacovigilance study for natalizumab (NAT). Anticytomegalovirus (CMV) and antivaricella-zoster (VZV) antibody levels served as controls. Results Prior to treatment with NAT, anti-JCV antibody levels were stable in the anti-JCV positive patients. During therapy, a slight decrease in anti-JCV and anti-VZV antibody levels, but not anti-CMV antibody levels, was observed. All five patients who developed PML showed a mild to moderate increase in anti-JCV antibody levels at time of PML diagnosis; pre-PML samples suggested that this increase might start already prior to diagnosis of PML. Conclusions Treatment initiation with NAT may lead to a slight decrease in anti-JCV and anti-VZV antibody levels, suggestive of a mild suppressive effect of NAT on antibody levels. Our findings in five cases of PML demonstrate that the onset of PML can be accompanied by increasing anti-JCV antibodies in serum. Monitoring of anti-JCV antibody levels could potentially be used as a tool for prediction or earlier diagnosis of PML during NAT treatment for MS. Further studies are warranted. PMID:23463870
Changes to anti-JCV antibody levels in a Swedish national MS cohort.
Warnke, Clemens; Ramanujam, Ryan; Plavina, Tatiana; Bergström, Tomas; Goelz, Susan; Subramanyam, Meena; Kockum, Ingrid; Rahbar, Afsar; Kieseier, Bernd C; Holmén, Carolina; Olsson, Tomas; Hillert, Jan; Fogdell-Hahn, Anna
2013-11-01
The anti-JC virus (JCV) antibody status has been introduced to stratify patients with multiple sclerosis (MS) for higher or lower risk of progressive multifocal leukoencephalopathy (PML). To assess the potential utility of anti-JCV antibody levels for earlier diagnosis or prediction of PML. An analytically validated antibody assay was used to determine serological status, normalised optical density values, and dilution titres for anti-JCV antibodies. The method was applied to stored sera of 1157 patients with MS including five cases of PML, all enrolled in the Swedish pharmacovigilance study for natalizumab (NAT). Anticytomegalovirus (CMV) and antivaricella-zoster (VZV) antibody levels served as controls. Prior to treatment with NAT, anti-JCV antibody levels were stable in the anti-JCV positive patients. During therapy, a slight decrease in anti-JCV and anti-VZV antibody levels, but not anti-CMV antibody levels, was observed. All five patients who developed PML showed a mild to moderate increase in anti-JCV antibody levels at time of PML diagnosis; pre-PML samples suggested that this increase might start already prior to diagnosis of PML. Treatment initiation with NAT may lead to a slight decrease in anti-JCV and anti-VZV antibody levels, suggestive of a mild suppressive effect of NAT on antibody levels. Our findings in five cases of PML demonstrate that the onset of PML can be accompanied by increasing anti-JCV antibodies in serum. Monitoring of anti-JCV antibody levels could potentially be used as a tool for prediction or earlier diagnosis of PML during NAT treatment for MS. Further studies are warranted.
NASA Astrophysics Data System (ADS)
Craig, Timothy J.; Parnell-Turner, Ross
2018-06-01
The microseismic hypocenters plotted in our study, derived in Parnell-Turner et al. (2017), used data collected by instrumentation from the NERC Ocean-Bottom Instrumentation Facility (Minshull et al., 2005) under the auspices of NERC projects NE/J022551/1, NE/J02029X/1 and NE/J021741/1 led by Tim Reston, Christine Peirce and Christopher MacLeod, during cruises JC102 and JC109 led by Christine Peirce. The raw seismic data from the OBS deployment are available from the NERC's British Oceanographic Data Centre (https://www.bodc.ac.uk), or by contacting the NERC grant-holders directly.
Wang, Gang; Sun, Yanwei; Xu, Ruirui; Qu, Jing; Tee, Chuansia; Jiang, Xiyuan; Ye, Jian
2014-04-01
Jatropha curcas mosaic disease (JcMD) is a newly emerging disease that has been reported in Africa and India. Here, we report the complete nucleotide sequence of a new Indian cassava mosaic virus isolate (ICMV-SG) from Singapore. Infection of ICMV-SG showed more severe JcMD in Jatropha curcas and Nicotiana benthamiana than the other ICMV isolates reported previously, though ICMV-SG shares high sequence identity with the other ICMV isolates. Agroinfectious DNA-A alone sufficiently induced systemic symptoms in N. benthamiana, but not in J. curcas. Results from agroinfection assays showed that systemic infection of ICMV-SG in J. curcas required both DNA-A and DNA-B components.
Mutations Allow JC Polyomaviruses to Elude Antibody Recognition | Center for Cancer Research
JC polyomavirus (JCV) infects the urinary tract of most adults. In healthy individuals, JCV infection does not cause noticeable symptoms. However, in those with compromised immune systems, JCV can cause a lethal brain disease called progressive multifocal leukoencephalopathy (PML). Data from a recently approved assay to detect serum antibodies specific for the JCV protein VP1 revealed that patients with antibodies are at increased risk of developing PML. At the same time, sequencing studies of JCV in cerebrospinal fluid (CSF) identified a number of mutations in VP1. Christopher Buck, Ph.D., and Diana Pastrana, Ph.D., of CCR’s Laboratory of Cellular Oncology, and their colleagues hypothesized that the VP1 mutations could allow the virus to evade antibody-mediated elimination.
Separation of solids by varying the bulk density of a fluid separating medium
Peterson, Palmer L.; Duffy, James B.; Tokarz, Richard D.
1978-01-01
A method and apparatus for separating objects having a density greater than a selected density value from objects having a density less than said selected density value. The method typically comprises: (a) providing a separation vessel having an upper and lower portion, said vessel containing a liquid having a density exceeding said selected density value; (b) reducing the apparent density of the liquid to said selected density value by introducing solid, bubble-like bodies having a density less than that of the liquid into the lower portion of the vessel and permitting them to rise therethrough; (c) introducing the objects to be separated into the separation vessel and permitting the objects having a density greater than the apparent density of the liquid to sink to the lower portion of the vessel, while the objects having a density less than said selected density value float in the upper portion of the vessel; and (d) separately removing the higher density objects in the lower portion and the lower density objects in the upper portion from the separation vessel. The apparatus typically comprises: (a) a vessel containing a liquid having a density such that at least part of said objects having a density exceeding said selected density value will float therein; (b) means to place said objects into said vessel; (c) means to reduce the effective density of at least a portion of said liquid to said selected density value, whereby said objects having a density exceeding said selected density value sink into said liquid and said objects having a density less than said selected density value remain afloat, said means to adjust the effective density comprising solid, bubble-like bodies having a density less than said selected density value and means for introducing said bodies into said liquid; and (d) means for separately removing said objects having a density exceeding said selected density value and said objects having a density less than said selected density value from said vessel.
Volcano-rift interaction on Venus: initial results from the Beta-Atla-Themis region.
NASA Astrophysics Data System (ADS)
Lopez, I.; Martin-Gonzalez, F.; Marquez, A.; de Pablo, M. A.; Carreno, F.
Extensional deformation and volcanism are widespread and geographically related processes on the surface of Venus (e.g. Head et al., 1992; Solomon et al., 1992). We report the initial results of an ongoing study on the interaction between fracture belts (chasmata and fossae) and large to intermediate-size volcanoes on Venus. The initial work focused in Beta-Atla-Themis, a region centered at ˜ 250o of longitude that covers ˜ 20 percent of the surface of the planet in which concentration of volcanic centers and fracture belts exceeds the global mean density (e.g. Crumpler et al., 1993). We carried out a survey of the volcanic features located in and close to fracture belts using existing volcano databases (Crumpler and Aubele, 2000) updated during this initial stage of our study through the analysis of full-resolution Magellan radar images for the studied region. We identified over a hundred volcanic features of different size and type (large volcanoes, intermediate-size volcanoes, steep-side domes and modified or fluted edifices) located in or near fracture belts. In this initial work, we have also established the time relationship that exist between each volcanic feature and the fracture belts and found that volcanic edifices predate, postdate or develop contemporaneously to extensional fracturing. Detailed structural mapping of locations where extensional fracturing and the formation of volcanoes is related is being carried out. In these geological settings the fracture patterns resulting from the interaction between both processes can help to constrain the different processes that operate during volcano growth (i.e. dike intrusion, chamber inflation, volcanic sagging and volcanic spreading) and its interaction with the regional stress fields responsible for the fracture belts. References: - Crumpler L.S. and J.C. Aubele (2000). Volcanism on Venus. In Encyclopedia of volcanoes, (Sigurdsson, H, B. Houghton, S.R. McNutt, H. Rymer, J. Stix, eds), p.727- 770. Academic Press. - Crumpler, L.S., J.W. Head and J.C. Aubele (1993). Relation of mayor volcanic center concentration on Venus to global tectonic patterns. Science, 261, p.591-595. - Head, J.W., L.S. Crumpler, J.C. Aubele, J.E. Guest and R.S. Saunders (1992). Venus volcanism: Classification of volcanic features and structures, associations, and global 1 distribution from Magellan data. J. Geophys. Res., 97, p.13153-13197. - Solomon S.C., S.E. Smrekar, D.L. Bindschadler, R.E. Grimm, W.M. Kaula, G.E. McGill, R.J. Phillips, R.S. Saunders, G. Schubert, S.W, Squyres and E.R. Stofan (1992). Venus tectonics: An overview of Magellan observations. J. Geophys. Res., 97, p.13199-13255. 2
... of your drowsiness. Alternative Names Sleepiness - during the day; Hypersomnia; Somnolence References Chokroverty S, Avidan AY. Sleep and its disorders. In: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy SL, eds. Bradley's Neurology in ...
Revised estimates for continuous shoreline fumigation: a PDF approach.
Nazir, Muddassir; Khan, Faisal I; Husain, Tahir
2005-02-14
A probability density function (PDF) fumigation model is presented here to study the dispersion of air pollutants emitted from a tall stack on the shoreline. This work considers dispersion of the pollutants in the stable layer and within the thermal internal boundary layer (TIBL) proceeds independently. The growth of TIBL is considered parabolic with distance inland. Turbulence is taken as homogeneous and stationary. Dispersion of particles (contaminant) in lateral and vertical directions is assumed independent of each other. This assumption allows us to consider the position of particles in both directions as independent random variables. The lateral dispersion distribution within the TIBL is considered as Gaussian and independent of height. A skewed bi-Gaussian vertical velocity PDF is used to account for the physics of dispersion due to different characteristics of updrafts and downdrafts within the TIBL. We have used Weil (J.C. Weil, A diagnosis of the asymmetry in top-down and bottom-up diffusion using a Lagrangian stochastic model, J. Atmos. Sci., 47 (1990) 501-515) solutions to find out the parameters of this PDF. Incorporating finite Lagrangian integral time scale for the vertical velocity component, it is observed that it reduces the vertical dispersion in the beginning and moves the point of maximum concentration further downwind. Due to little dispersion in the beginning, there is more plume to be dispersed causing higher concentrations at large distances. The model has considered Weil and Brower's (J.C. Weil, P.R. Brower, Estimating convective boundary layer parameters for diffusion applications, Maryland Power Plant Siting Program Rep. PPSP-MP-48, Department of Natural Resources, Annapolis, MD, 1985, 37 pp.) convective limit to analyze dispersion characteristics within TIBL. The revised model discussed here is evaluated with the data available from the Nanticoke field experiment on fumigation conducted in summer of 1978 in Ontario, Canada. The results of revised model are in good agreement with the observed data.
Buchholz, Jens; Schwentner, Andreas; Brunnenkan, Britta; Gabris, Christina; Grimm, Simon; Gerstmeir, Robert; Takors, Ralf; Eikmanns, Bernhard J; Blombach, Bastian
2013-09-01
Exchange of the native Corynebacterium glutamicum promoter of the aceE gene, encoding the E1p subunit of the pyruvate dehydrogenase complex (PDHC), with mutated dapA promoter variants led to a series of C. glutamicum strains with gradually reduced growth rates and PDHC activities. Upon overexpression of the l-valine biosynthetic genes ilvBNCE, all strains produced l-valine. Among these strains, C. glutamicum aceE A16 (pJC4 ilvBNCE) showed the highest biomass and product yields, and thus it was further improved by additional deletion of the pqo and ppc genes, encoding pyruvate:quinone oxidoreductase and phosphoenolpyruvate carboxylase, respectively. In fed-batch fermentations at high cell densities, C. glutamicum aceE A16 Δpqo Δppc (pJC4 ilvBNCE) produced up to 738 mM (i.e., 86.5 g/liter) l-valine with an overall yield (YP/S) of 0.36 mol per mol of glucose and a volumetric productivity (QP) of 13.6 mM per h [1.6 g/(liter × h)]. Additional inactivation of the transaminase B gene (ilvE) and overexpression of ilvBNCD instead of ilvBNCE transformed the l-valine-producing strain into a 2-ketoisovalerate producer, excreting up to 303 mM (35 g/liter) 2-ketoisovalerate with a YP/S of 0.24 mol per mol of glucose and a QP of 6.9 mM per h [0.8 g/(liter × h)]. The replacement of the aceE promoter by the dapA-A16 promoter in the two C. glutamicum l-lysine producers DM1800 and DM1933 improved the production by 100% and 44%, respectively. These results demonstrate that C. glutamicum strains with reduced PDHC activity are an excellent platform for the production of pyruvate-derived products.
Buchholz, Jens; Schwentner, Andreas; Brunnenkan, Britta; Gabris, Christina; Grimm, Simon; Gerstmeir, Robert; Takors, Ralf; Eikmanns, Bernhard J.
2013-01-01
Exchange of the native Corynebacterium glutamicum promoter of the aceE gene, encoding the E1p subunit of the pyruvate dehydrogenase complex (PDHC), with mutated dapA promoter variants led to a series of C. glutamicum strains with gradually reduced growth rates and PDHC activities. Upon overexpression of the l-valine biosynthetic genes ilvBNCE, all strains produced l-valine. Among these strains, C. glutamicum aceE A16 (pJC4 ilvBNCE) showed the highest biomass and product yields, and thus it was further improved by additional deletion of the pqo and ppc genes, encoding pyruvate:quinone oxidoreductase and phosphoenolpyruvate carboxylase, respectively. In fed-batch fermentations at high cell densities, C. glutamicum aceE A16 Δpqo Δppc (pJC4 ilvBNCE) produced up to 738 mM (i.e., 86.5 g/liter) l-valine with an overall yield (YP/S) of 0.36 mol per mol of glucose and a volumetric productivity (QP) of 13.6 mM per h [1.6 g/(liter × h)]. Additional inactivation of the transaminase B gene (ilvE) and overexpression of ilvBNCD instead of ilvBNCE transformed the l-valine-producing strain into a 2-ketoisovalerate producer, excreting up to 303 mM (35 g/liter) 2-ketoisovalerate with a YP/S of 0.24 mol per mol of glucose and a QP of 6.9 mM per h [0.8 g/(liter × h)]. The replacement of the aceE promoter by the dapA-A16 promoter in the two C. glutamicum l-lysine producers DM1800 and DM1933 improved the production by 100% and 44%, respectively. These results demonstrate that C. glutamicum strains with reduced PDHC activity are an excellent platform for the production of pyruvate-derived products. PMID:23835179
NASA Astrophysics Data System (ADS)
Schuele, Paul J.; Schmidt, V. Hugo
1989-02-01
Pressure and temperature effects on the one dimensional (1D) and higher-dimensionality correlations associated with the ferroelectric and antiferroelectric phase transitions in cesium dihydrogen phosphate were studied by means of the 133Cs nuclear magnetic resonance (NMR) spin-lattice relaxation time T1. We measured T1 at 6.5 MHz at temperatures down to the ferroelectric (FE) Curie point TC at 1 bar and at 1.5 and 3.0 kbar, down to the triple point Tt=124.6 K at 3.3 kbar, and down to the antiferroelectric (AFE) Néel point TN at 3.6 kbar. With decreasing temperature, T1 first decreases exponentially due to 1D fluctuations associated with the Jb interactions in disordered hydrogen-bonded chains running along b. As the temperature falls further, T1 then decreases linearly as the Jc interaction between these chains in hydrogen-bonded planes comes into play. From these results and the known pressure derivatives of TC and TN, we calculated pressure dependences for Jb, Jc, and for the interplanar interaction Ja. At 3.3 kbar Ja changes sign, so the plane stacking becomes AFE instead of FE. Above 8.9 kbar, where Jc extrapolates to zero, a new AFE phase with a checkerboard arrangement of FE b chains is predicted.
Genome-wide analysis of the GRAS gene family in physic nut (Jatropha curcas L.).
Wu, Z Y; Wu, P Z; Chen, Y P; Li, M R; Wu, G J; Jiang, H W
2015-12-29
GRAS proteins play vital roles in plant growth and development. Physic nut (Jatropha curcas L.) was found to have a total of 48 GRAS family members (JcGRAS), 15 more than those found in Arabidopsis. The JcGRAS genes were divided into 12 subfamilies or 15 ancient monophyletic lineages based on the phylogenetic analysis of GRAS proteins from both flowering and lower plants. The functions of GRAS genes in 9 subfamilies have been reported previously for several plants, while the genes in the remaining 3 subfamilies were of unknown function; we named the latter families U1 to U3. No member of U3 subfamily is present in Arabidopsis and Poaceae species according to public genome sequence data. In comparison with the number of GRAS genes in Arabidopsis, more were detected in physic nut, resulting from the retention of many ancient GRAS subfamilies and the formation of tandem repeats during evolution. No evidence of recent duplication among JcGRAS genes was observed in physic nut. Based on digital gene expression data, 21 of the 48 genes exhibited differential expression in four tissues analyzed. Two members of subfamily U3 were expressed only in buds and flowers, implying that they may play specific roles. Our results provide valuable resources for future studies on the functions of GRAS proteins in physic nut.
Dalling, James W.; Stump, Simon M.; U’Ren, Jana M.; Arnold, A. Elizabeth
2017-01-01
The Janzen–Connell (JC) hypothesis provides a conceptual framework for explaining the maintenance of tree diversity in tropical forests. Its central tenet—that recruits experience high mortality near conspecifics and at high densities—assumes a degree of host specialization in interactions between plants and natural enemies. Studies confirming JC effects have focused primarily on spatial distributions of seedlings and saplings, leaving major knowledge gaps regarding the fate of seeds in soil and the specificity of the soilborne fungi that are their most important antagonists. Here we use a common garden experiment in a lowland tropical forest in Panama to show that communities of seed-infecting fungi are structured predominantly by plant species, with only minor influences of factors such as local soil type, forest characteristics, or time in soil (1–12 months). Inoculation experiments confirmed that fungi affected seed viability and germination in a host-specific manner and that effects on seed viability preceded seedling emergence. Seeds are critical components of reproduction for tropical trees, and the factors influencing their persistence, survival, and germination shape the populations of seedlings and saplings on which current perspectives regarding forest dynamics are based. Together these findings bring seed dynamics to light in the context of the JC hypothesis, implicating them directly in the processes that have emerged as critical for diversity maintenance in species-rich tropical forests. PMID:28973927
Birk, Efrat; Har-Zahav, Adi; Manzini, Chiara M.; Pasmanik-Chor, Metsada; Kornreich, Liora; Walsh, Christopher A.; Noben-Trauth, Konrad; Albin, Adi; Simon, Amos J.; Colleaux, Laurence; Morad, Yair; Rainshtein, Limor; Tischfield, David J.; Wang, Peter; Magal, Nurit; Maya, Idit; Shoshani, Noa; Rechavi, Gideon; Gothelf, Doron; Maydan, Gal; Shohat, Mordechai; Basel-Vanagaite, Lina
2010-01-01
Intellectual disability (ID) affects 1%–3% of the general population. We recently reported on a family with autosomal-recessive mental retardation with anterior maxillary protrusion and strabismus (MRAMS) syndrome. One of the reported patients with ID did not have dysmorphic features but did have temporal lobe epilepsy and psychosis. We report on the identification of a truncating mutation in the SOBP that is responsible for causing both syndromic and nonsyndromic ID in the same family. The protein encoded by the SOBP, sine oculis binding protein ortholog, is a nuclear zinc finger protein. In mice, Sobp (also known as Jxc1) is critical for patterning of the organ of Corti; one of our patients has a subclinical cochlear hearing loss but no gross cochlear abnormalities. In situ RNA expression studies in postnatal mouse brain showed strong expression in the limbic system at the time interval of active synaptogenesis. The limbic system regulates learning, memory, and affective behavior, but limbic circuitry expression of other genes mutated in ID is unusual. By comparing the protein content of the +/jc to jc/jc mice brains with the use of proteomics, we detected 24 proteins with greater than 1.5-fold differences in expression, including two interacting proteins, dynamin and pacsin1. This study shows mutated SOBP involvement in syndromic and nonsyndromic ID with psychosis in humans. PMID:21035105
NASA Astrophysics Data System (ADS)
Roy, Swagata; Biswas, Srija; Babu, K. Arun; Mandal, Sumantra
2018-05-01
A novel constitutive model has been developed for predicting flow responses of super-austenitic stainless steel over a wide range of strains (0.05-0.6), temperatures (1173-1423 K) and strain rates (0.001-1 s-1). Further, the predictability of this new model has been compared with the existing Johnson-Cook (JC) and modified Zerilli-Armstrong (M-ZA) model. The JC model is not befitted for flow prediction as it is found to be exhibiting very high ( 36%) average absolute error (δ) and low ( 0.92) correlation coefficient (R). On the contrary, the M-ZA model has demonstrated relatively lower δ ( 13%) and higher R ( 0.96) for flow prediction. The incorporation of couplings of processing parameters in M-ZA model has led to exhibit better prediction than JC model. However, the flow analyses of the studied alloy have revealed the additional synergistic influences of strain and strain rate as well as strain, temperature, and strain rate apart from those considered in M-ZA model. Hence, the new phenomenological model has been formulated incorporating all the individual and synergistic effects of processing parameters and a `strain-shifting' parameter. The proposed model predicted the flow behavior of the alloy with much better correlation and generalization than M-ZA model as substantiated by its lower δ ( 7.9%) and higher R ( 0.99) of prediction.
Shi, Xiaodong; Gu, Yuxi; Dai, Tingwei; Wu, Yang; Wu, Peng; Xu, Ying; Chen, Fang
2018-06-05
Trichomes are epidermal outgrowths of plant tissues that can secrete or store large quantities of secondary metabolites, which contribute to plant defense responses against stress. The use of bioengineering methods for regulating the development of trichomes and metabolism is a widely researched topic. In the present study, we demonstrate that JcZFP8, a C2H2 zinc finger protein gene from Jatropha curcas L., can regulate trichome development in transgenic tobacco. To understand the underlying mechanisms, we performed transcriptome profiling of overexpression JcZFP8 transgenic plants and wild-type tobacco. Based on the analysis of differentially expressed genes, we determined that genes of the plant hormone signal transduction pathway was significantly enriched, suggesting that these pathways were modulated in the transgenic plants. In addition, the transcript levels of the known trichome-related genes in Arabidopsis were not significantly changed, whereas CycB2 and MYB genes were differentially expressed in the transgenic plants. Despite tobacco and Arabidopsis have different types of trichomes, all the pathways were associated with C2H2 zinc finger protein genes. Our findings help us to understand the regulation of multicellular trichome formation and suggest a new metabolic engineering method for the improvement of plants. Copyright © 2018 Elsevier B.V. All rights reserved.
Tuning Vortex Creep in Irradiated YBa2Cu3O7-δ Coated Conductors
NASA Astrophysics Data System (ADS)
Eley, Serena; Kihlstrom, Karen; Holleis, Sigrid; Leroux, Maxime; Rupich, Martin; Miller, Dean; Kayani, Asghar; Welp, Ulrich; Kwok, Wai-Kwong; Civale, Leonardo
YBa2Cu3O7-δ coated conductors (CCs) show non-monotonic changes in the temperature-dependent creep rate, S (T) , due to mixed pinning landscapes comprised of twin boundaries, planar defects, point defects, and nanoparticle precipitates. Notably, in low fields, there is a conspicuous dip in S as T increases from ~20K to ~65K. The source of this dip is poorly understood. Moreover, pinning landscapes that are favorable for high critical currents, Jc, are not necessarily optimal for low S. We have found that, though oxygen irradiation introduces few-nm-sized defects that result in significant increases in Jc, it is detrimental to creep, increasing S (reducing the dip depth) for T > 20K. Understanding the source of this dip is crucial to engineering pinning landscapes that concurrently promote high Jc and low S. To this end, we study changes in S (T) as we tune the ratio of smaller (point to few-nm-sized) defects to larger nanoparticles in an oxygen-irradiated CC by annealing in O2 at 250°C to 600°C. We observe a steady decrease in S (T > 20K) with increasing annealing temperature. This suggests that pre-existing nanoparticle precipitates are likely responsible for the dip in S (T) , and underlines the fact that the effects of defects are not additive, but rather can be competitive.
Black AR, Cowan KH. Cancer biology and genetics. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 181. Kumar V, Abbas AK, Aster JC. Neoplasia. ...
ERIC Educational Resources Information Center
Kemnitzer, Luis S.
1978-01-01
Analyzing the Yuwipi ceremony of the Dakota Sioux, this article describes a single performance and then discusses the Yuwipi in terms of its general meaning (light phase, dark phase, marginal phase, and feast). (JC)
Bechham JD, Solbrig MV, Tyler KL. Viral encephalitis and meningitis. In: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy SL, eds. Bradley's Neurology in Clinical Practice . 7th ed. Philadelphia, PA: Elsevier; 2016:chap ...
NASA Astrophysics Data System (ADS)
Garbacz, Piotr
2018-05-01
Results of quantum mechanical computations of the antisymmetric part of the indirect spin-spin coupling tensor, ?, performed using the coupled-cluster method, the second-order polarisation propagator approximation, and the density functional theory for 25 molecules and nearly 100 spin-spin couplings are reported. These results are used for an estimation of the magnitude of the recently proposed liquid-state nuclear magnetic resonance chirality-sensitive effect, which allows to determine the molecular chirality directly, i.e. without the need for the application of any chiral agent. The following were found: (i) the antisymmetry J⋆ is usually larger for the coupling between spins separated by two chemical bonds in comparison with the coupling through one bond, (ii) promising samples are those which contain fluorine, and (iii) the antisymmetry of the spin-spin coupling tensor is of the order of a few hertz for commercially available chemical compounds. Therefore, the relevant property of the experiment, the pseudoscalar Jc, for them is of the order of 1 nHz m/V.
Vortex Escape from Columnar Defect in a Current-Loaded Superconductor
NASA Astrophysics Data System (ADS)
Fedirko, V. A.; Kasatkin, A. L.; Polyakov, S. V.
2018-06-01
The problem of Abrikosov vortices depinning from extended linear (columnar) defect in 3D-anisotropic superconductor film under non-uniformly distributed Lorentz force is studied for the case of low temperatures, disregarding thermal activation processes. We treat it as a problem of mechanical behavior of an elastic vortex string settled in a potential well of a linear defect and exerted to Lorentz force action within the screening layer about the London penetration depth near the specimen surface. The stability problem for the vortex pinning state is investigated by means of numerical modeling, and conditions for the instability threshold are obtained as well as the critical current density j_c and its dependence on the film thickness and magnetic field orientation. The instability leading to vortex depinning from extended linear defect first emerges near the surface and then propagates inside the superconductor. This scenario of vortex depinning mechanism at low temperatures is strongly supported by some recent experiments on high-Tc superconductors and other novel superconducting materials, containing columnar defects of various nature.
Temperature dependence of lower critical field of YBCO superconductor
NASA Astrophysics Data System (ADS)
Rani, Poonam; Hafiz, A. K.; Awana, V. P. S.
2018-05-01
We report the detailed study of the temperature dependence of the lower critical field (Hc1) of the YBa2Cu3O7 superconductor by magnetization measurements. The curve shows the multiband gap behavior of the sample. It is found that the sample is not a single BCS type superconductor. Hc1 is measured as the point at which the curve deviates from a Meissner-like linear M(H) curve to a nonlinear path. The Hc1 for YBCO at different temperatures from 10K to 85K has been determined by magnetization measurements M(H) with applied field parallel to the c-axis. The sample phase purity has been confirmed by Rietveld fitted X-ray diffraction data. The amplitude (1-17Oe) dependent AC susceptibility confirms the granular nature of superconducting compound. Using Bean model we calculated the temperature dependency of inter-grain critical current density and Jc(0) is found as 699.14kAcm-2.
... Mazziotta JC, Pomeroy SL, eds. Bradley's Neurology in Clinical Practice . 7th ed. Philadelphia, PA: Elsevier; 2016:chap 17. Purvin V, Glaser JS. Topical diagnosis: prechiasmal visual pathways. In: Tasman W, Jaeger EA, ...
... Bates ER, Blankenship JC, et al. 2015 ACC/AHA/SCAI Focused update on primary percutaneous coronary intervention ... myocardial infarction: an update of the 2011 ACCF/AHA/SCAI guideline for percutaneous coronary intervention and the ...
American Therapeutic Recreation Association
... Affiliates ATRA Committees ATRA Task Forces ATRA Sections International RT/TR Month Member Directory Social Networking Board Calls and Member-Only Webinars Federal Public Policy Coverage Joint Commission (JC) Commission on Accreditation ...
... whole tooth. This area is known as the "pulp" of the tooth. The jawbone is attached to ... JC, eds. Robbins and Cotran Pathologic Basis of Disease . 9th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap ...
Ishii, Satoshi; Ashida, Naoaki; Ohno, Hiroki; Segawa, Takahiro; Yabe, Shuhei; Otsuka, Shigeto; Yokota, Akira; Senoo, Keishi
2017-06-01
Thirty-nine denitrifying bacterial strains closely related to one another, represented by strains TSA40T and TSA66T, were isolated from rice paddy soils. Strains TSA40T and TSA66T were Gram-stain-negative, slightly curved rod-shaped, and motile by means of polar flagella. They were able to reduce nitrate, nitrite and nitrous oxide, but unable to fix atmospheric N2. While strain TSA66T was able to grow autotrophically by H2-dependent denitrification, strain TSA40T could not. Phylogenetic analysis suggested that they belong to the family Oxalobacteraceae, the order Burkholderiales in the class Betaproteobacteria. Major components in the fatty acids (C16 : 0, C17 : 0 cyclo, C18 : 1ω7c and summed feature 3) and quinone (Q-8) also supported the affiliation of strains TSA40T and TSA66T to the family Oxalobacteraceae. Based on 16S rRNA gene sequence comparisons, strains TSA40T and TSA66T showed the greatest degree of similarity to Herbaspirillum massiliense JC206T, Noviherbaspirillum malthae CC-AFH3T, Noviherbaspirillum humi U15T, Herbaspirillum seropedicae Z67T and Paucimonas lemoignei LMG 2207T, and lower similarities to the members of other genera. Average nucleotide identity values between the genomes of strain TSA40T, TSA66T and H. massiliense JC206T were 75-77 %, which was lower than the threshold value for species discrimination (95-96 %). Based on the 16S rRNA gene sequence analysis in combination with physiological, chemotaxonomic and genomic properties, strains TSA40T (=JCM 17722T=ATCC TSD-69T) and TSA66T (=JCM 17723T=DSM 25787T) are the type strains of two novel species within the genus Noviherbaspirillum, for which the names Noviherbaspirillum denitrificans sp. nov. and Noviherbaspirillum autotrophicum sp. nov. are proposed, respectively. We also propose the reclassification of Herbaspirillum massiliense as Noviherbaspirillum massiliense comb. nov.
Genetics Home Reference: hyperlysinemia
... Sources for This Page Markovitz PJ, Chuang DT, Cox RP. Familial hyperlysinemias. Purification and characterization of the ... Biery BJ, Morrell JC, Goodman BK, Geisbrecht BV, Cox RP, Gould SJ, Geraghty MT. Identification of the ...
Genetics Home Reference: Griscelli syndrome
... Jacob CM, Cristofani L, Casella EB, Voltarelli JC, de Saint-Basile G, Espreafico EM. Griscelli syndrome: characterization ... Asal GT, Tezcan I, Metin A, Lambert N, de Saint Basile G, Sanal O. Griscelli syndrome types ...
(HVPE) growth of III-V materials for high-efficiency 1-sun to low-concentration solar cell applications growth, 2011. Timothy, J.C., D.L. Young, and T.A. Gessert, Modeling, Characterization, and Properties of
ERIC Educational Resources Information Center
Appalachia, 1976
1976-01-01
Detailing the present socioeconomic status of Appalachia, this article presents relevant data on Appalachian job opportunities, economic growth, human services, natural resources, governmental structure, population growth, income, health care, education levels, housing, and community services. (JC)
The Geneva Conference--A Summary
ERIC Educational Resources Information Center
American Indian Journal, 1977
1977-01-01
The "Final Resolution" of the International Non-Governmental Organizations Conference on Discrimination Against Indigenous Populations (1977) is detailed in this article which describes the program of action for the legal field and the sociocultural field. (JC)
ERIC Educational Resources Information Center
Serrao, John
1976-01-01
Emphasizing the spring migration of frogs, toads, and salamanders to their watery breeding sites, this article presents information on numerous amphibians and suggests both indoor and outdoor educational activities appropriate for elementary and/or early secondary instruction. (JC)
ERIC Educational Resources Information Center
Lewis, Norman
1978-01-01
Describing Bolivia's interest in encouraging Caucasian immigrants from South Africa, for purposes of settling and developing traditionally Indian lands, this article details the miserable conditions of slavery and cultural/physical genocide currently operative in Bolivia. (JC)
... pulse References Fang JC, O'Gara PT. The history and physical examination. In: Mann DL, Zipes DP, Libby P, Bonow RO, Braunwald E, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine . 10th ed. Philadelphia, PA: Elsevier ...
... Yoga References Fang JC, O’Gara PT. The history and physical examination. In: Mann DL, Zipes DP, Libby P, Bonow RO, Braunwald E, eds. Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine . 10th ed. Philadelphia, PA: Elsevier ...
Genetics Home Reference: periventricular heterotopia
... Metcalfe KA, Isidor B, Louvier UW, Poduri A, Taylor JC, Tilly P, Poirier K, Saillour Y, Lebrun N, Stemmelen T, Rudolf G, Muraca G, Saintpierre B, Elmorjani A; Deciphering Developmental Disorders study, Moïse M, ...
... FF, eds. Ferri's Clinical Advisor 2017 . Philadelphia, PA: Elsevier; 2017:562.e1-563.e1. Hahn D, Hodson ... JG, ed. Emergency Medicine . 2nd ed. Philadelphia, PA: Elsevier Saunders; 2013:chap 22. Jennette JC, Falk RJ, ...
Dementia due to metabolic causes
... may cause confusion and changes in thinking or reasoning. These changes may be short-term or lasting. ... Mazzotta JC, Pomeroy SL, eds. Bradley's Neurology in Clinical Practice . 7th ed. Philadelphia, PA: Elsevier; 2016:chap ...
The Educational Administrator as "The Prince".
ERIC Educational Resources Information Center
Ryder, Sarah
1979-01-01
Quoting from Machiavelli's "Il Principe", the author demonstrates by explication and example that what was true for fifteenth century Italy is true today and maintains that principles for successful administration are universal and timeless. (JC)
Subacute combined degeneration
... SCD Images Central nervous system and peripheral nervous system Central nervous system References Pytel P, Anthony DC. Peripheral nerves and ... chap 27. So YT. Deficiency diseases of the nervous system. In: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy ...
Genetics Home Reference: mycosis fungoides
... Cigudosa JC, Barranco C, Serrano S, Dummer R, Tensen CP, Solé F, Pujol RM, Espinet B. Oligonucleotide array- ... K, Knijnenburg J, Boer JM, Willemze R, Tensen CP. Oncogenomic analysis of mycosis fungoides reveals major differences ...
Indians in Almanacs (1793-1815)
ERIC Educational Resources Information Center
Wenrick, Jon S.
1975-01-01
The American Indian appeared frequently in the almanac literature of 1783-1815 and was used as a source of humor, political comment, romanticism, etc, much of which contributed to the cultural conflict of the times. (JC)
Over-the-counter pain relievers
... Waltham, MA: Elsevier; 2016:236-272. Dinakar P. Principles of pain management. In: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy SL, eds. Bradley's Neurology in Clinical Practice . 7th ed. Philadelphia, PA: Elsevier; 2016:chap 54.
Smoking induces transcription of the heat shock protein system in the joints.
Ospelt, Caroline; Camici, Giovanni G; Engler, Anna; Kolling, Christoph; Vogetseder, Alexander; Gay, Renate E; Michel, Beat A; Gay, Steffen
2014-07-01
Smoking increases the risk of developing rheumatoid arthritis (RA) and worsens the course of the disease. In the current study we analysed whether smoking can affect gene expression directly in the joints. Synovial fibroblasts were incubated with 5% cigarette smoke extract and changes in gene expression were detected using whole genome microarrays and verified with real-time PCR. Synovial tissues were obtained from smoking and non-smoking patients with RA undergoing joint replacement surgery and from mice exposed to cigarette smoke or ambient air in a whole body exposure chamber for 3 weeks. Microarray and real-time PCR analysis showed a significant upregulation of the heat shock proteins DnaJA4, DnaJB4, DnaJC6, HspB8 and Hsp70 after stimulation of synovial fibroblasts with 5% cigarette smoke extract. Similarly, in synovial tissues of smokers with RA the expression of DnaJB4, DnaJC6, HspB8 and Hsp70 was significantly higher compared with non-smokers with RA. Upregulation of DnaJB4 and DnaJC6 in joints by smoking was also confirmed in mice exposed to cigarette smoke. Our data clearly show that smoking can change gene expression in the joints, which can lead to the activation of signalling pathways that promote development of autoimmunity and chronic joint inflammation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
Cao, Lijun; Li, Dongfang; Feng, Peng; Li, Lin; Xue, Guo-Fang; Li, Guanglai; Hölscher, Christian
2016-04-13
The incretins glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are growth factors. GLP-1 mimetics are on the market as treatments for type 2 diabetes. Both GLP-1 and GIP mimetics have shown neuroprotective properties in previous studies. In addition, the GLP-1 mimetic exendin-4 has shown protective effects in a clinical trial in Parkinson's disease (PD) patients. Novel GLP-1/GIP dual-agonist peptides have been developed to treat diabetes. Here, we report the neuroprotective effects of a novel dual agonist (DA-JC1) in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. MPTP was injected once daily (20 mg/kg intraperitoneally) for 7 days and the dual agonist was coinjected once daily (50 nmol/kg intraperitoneally). We found that the drug reduced most of the MPTP-induced motor impairments in the rotarod, open-field locomotion, and muscle strength test. The number of tyrosine hydroxylase-positive neurons in the substantia nigra and striatum was reduced by MPTP and increased by DA-JC1. Synapse numbers (synaptophysin expression) were reduced in the substantia nigra and the striatum by MPTP and DA-JC1 reversed this effect. The activation of a chronic inflammation response by MPTP was considerably reduced by the dual agonist (DA) (astroglia and microglia activation). Therefore, dual agonists show promise as a novel treatment of PD.
Coupled antiferromagnetic spin-1/2 chains in green dioptase, Cu6 [Si6O18.6] H2O
NASA Astrophysics Data System (ADS)
Podlesnyak, Andrey; Anovitz, L. M.; Kolesnikov, A. I.; Matsuda, M.; Prisk, T. R.; Ehlers, G.; Toth, S.
Gem crystals of natural dioptase with colors ranging from emerald-green to bluish have delighted people since ancient times and still attract attention of mineral collectors around the globe. The crystal structure of green dioptase (space group R 3) consists of corrugated silicate rings Si6O<18 interconnected by Cu2+ ions. Oxygen atoms form axially-elongated octahedral of CuO4(H2O)2. The magnetic ground state of green dioptase remains controversial. We report inelastic neutron scattering measurements of the magnetic excitations of green dioptase Cu6 [ Si6O18.6 ] H2O. The observed spectrum contains two magnetic modes and a prominent spin gap that is consistent with the ordered ground state of Cu moments coupled antiferromagnetically in spiral chains along the c axis and ferromagnetically in ab planes on the hexagonal cell. The data are in excellent agreement with a spin-1/2 Hamiltonian that includes AFM nearest-neighbor intra-chain coupling Jc = 10 . 6 (1) meV, ferromagnetic inter-chain coupling Jab = - 1 . 2 (1) meV and exchange anisotropy ΔJc = 0 . 14 (1) meV. This appears compatible with reduced Nèel temperature, TN = 14 . 5 K <
High-field transport properties of a P-doped BaFe2As2 film on technical substrate
Iida, Kazumasa; Sato, Hikaru; Tarantini, Chiara; Hänisch, Jens; Jaroszynski, Jan; Hiramatsu, Hidenori; Holzapfel, Bernhard; Hosono, Hideo
2017-01-01
High temperature (high-Tc) superconductors like cuprates have superior critical current properties in magnetic fields over other superconductors. However, superconducting wires for high-field-magnet applications are still dominated by low-Tc Nb3Sn due probably to cost and processing issues. The recent discovery of a second class of high-Tc materials, Fe-based superconductors, may provide another option for high-field-magnet wires. In particular, AEFe2As2 (AE: Alkali earth elements, AE-122) is one of the best candidates for high-field-magnet applications because of its high upper critical field, Hc2, moderate Hc2 anisotropy, and intermediate Tc. Here we report on in-field transport properties of P-doped BaFe2As2 (Ba-122) thin films grown on technical substrates by pulsed laser deposition. The P-doped Ba-122 coated conductor exceeds a transport Jc of 105 A/cm2 at 15 T for main crystallographic directions of the applied field, which is favourable for practical applications. Our P-doped Ba-122 coated conductors show a superior in-field Jc over MgB2 and NbTi, and a comparable level to Nb3Sn above 20 T. By analysing the E − J curves for determining Jc, a non-Ohmic linear differential signature is observed at low field due to flux flow along the grain boundaries. However, grain boundaries work as flux pinning centres as demonstrated by the pinning force analysis. PMID:28079117
High-field transport properties of a P-doped BaFe2As2 film on technical substrate
NASA Astrophysics Data System (ADS)
Iida, Kazumasa; Sato, Hikaru; Tarantini, Chiara; Hänisch, Jens; Jaroszynski, Jan; Hiramatsu, Hidenori; Holzapfel, Bernhard; Hosono, Hideo
2017-01-01
High temperature (high-Tc) superconductors like cuprates have superior critical current properties in magnetic fields over other superconductors. However, superconducting wires for high-field-magnet applications are still dominated by low-Tc Nb3Sn due probably to cost and processing issues. The recent discovery of a second class of high-Tc materials, Fe-based superconductors, may provide another option for high-field-magnet wires. In particular, AEFe2As2 (AE: Alkali earth elements, AE-122) is one of the best candidates for high-field-magnet applications because of its high upper critical field, Hc2, moderate Hc2 anisotropy, and intermediate Tc. Here we report on in-field transport properties of P-doped BaFe2As2 (Ba-122) thin films grown on technical substrates by pulsed laser deposition. The P-doped Ba-122 coated conductor exceeds a transport Jc of 105 A/cm2 at 15 T for main crystallographic directions of the applied field, which is favourable for practical applications. Our P-doped Ba-122 coated conductors show a superior in-field Jc over MgB2 and NbTi, and a comparable level to Nb3Sn above 20 T. By analysing the E - J curves for determining Jc, a non-Ohmic linear differential signature is observed at low field due to flux flow along the grain boundaries. However, grain boundaries work as flux pinning centres as demonstrated by the pinning force analysis.
NASA Technical Reports Server (NTRS)
Subramanyam, G.; Kapoor, V. J.; Chorey, C. M.; Bhasin, K. B.
1992-01-01
The paper describes the processing and electrical transport measurements for achieving reproducible high-Tc and high-Jc sputtered TlCaBaCuO thin films on LaAlO3 substrates, for microelectronic applications. The microwave properties of TlCaBaCuO thin films were investigated by designing, fabricating, and characterizing microstrip ring resonators with a fundamental resonance frequency of 12 GHz on 10-mil-thick LaAlO3 substrates. Typical unloaded quality factors for a ring resonator with a superconducting ground plane of 0.3 micron-thickness and a gold ground plane of 1-micron-thickness were above 1500 at 65 K. Typical values of penetration depth at 0 K in the TlCaBaCuO thin films were between 7000 and 8000 A.
NASA Astrophysics Data System (ADS)
Zongyu, Jing; Faqi, Li; Jiangzhong, Zou; Zhibiao, Wang
2006-05-01
Objectives: To develop a tissue mimicking phantom which can be used to evaluate the focusing performance of the HIFU transducer, and the phantom should has the same acoustic characteristic and thermotics characteristic as the biological tissue. Materials and methods: The tissue mimicking phantom was made from water, gelatin, fresh biologic tissue Its ultrasonic parameters (attenuation coefficient) of the phantom was measured by the method of radiation pressure, and thermotics parameters of the phantom, including thermal conductivity, specific heat/fusion point et al were tested under the Measurement meter. The HIFU biological effect of the phantom was evaluated under the Model JC focused ultrasound tumor therapeutic system, developed and produced by Chongqing HIFU Technology Co. Ltd (working frequency: 0.7MHz; acoustic power: 200W; focal distance: 135mm; Acoustic focal region: 3×3×25 cubic mm). Results: The self-made phantom is sable, has smooth and glossy appearance, well-distributed construction, and good elasticity. We measured the followed values for acoustic and thermal properties: density 1049±2 kg/m3; attenuation 0.532±0.017 dB/cm (0.8 MHz), 0.612±0.021 dB/cm (1.0 MHz); thermal conductivity 0.76±0.08 W/m/-°C; specific heat 3653±143 J/kg-°C; fusion point154±8°C. The BFR induced in the phantom after HIFU exposure was stable in its size and appearance. Conclusion: We produced and improved one tissue mimicking phantom successfully which had semblable ultrasound and thermphysical properties like the soft tissue, and can replace the bovine liver to investigate the HIFU biological effect and to detect the focusing performance of the HIFU energy transducer. The research was supported by Chongqing University of Medical Science (CX200320).
Effects of high-energy proton irradiation on the superconducting properties of Fe(Se,Te) thin films
NASA Astrophysics Data System (ADS)
Sylva, G.; Bellingeri, E.; Ferdeghini, C.; Martinelli, A.; Pallecchi, I.; Pellegrino, L.; Putti, M.; Ghigo, G.; Gozzelino, L.; Torsello, D.; Grimaldi, G.; Leo, A.; Nigro, A.; Braccini, V.
2018-05-01
In this paper we explore the effects of 3.5 MeV proton irradiation on Fe(Se,Te) thin films grown on CaF2. In particular, we carry out an experimental investigation with different irradiation fluences up to 7.30 · 1016 cm‑2 and different proton implantation depths, in order to clarify whether and to what extent the critical current is enhanced or suppressed, what are the effects of irradiation on the critical temperature, resistivity, and critical magnetic fields, and finally what is the role played by the substrate in this context. We find that the effect of irradiation on superconducting properties is generally small compared to the case of other iron-based superconductors. The irradiation effect is more evident on the critical current density Jc, while it is minor on the transition temperature Tc, normal state resistivity ρ, and on the upper critical field Hc2 up to the highest fluences explored in this work. In more detail, our analysis shows that when protons implant in the substrate far from the superconducting film, the critical current can be enhanced up to 50% of the pristine value at 7 T and 12 K; meanwhile, there is no appreciable effect on critical temperature and critical fields together with a slight decrease in resistivity. On the contrary, when the implantation layer is closer to the film–substrate interface, both critical current and temperature show a decrease accompanied by an enhancement of the resistivity and lattice strain. This result evidences that possible modifications induced by irradiation in the substrate may affect the superconducting properties of the film via lattice strain. The robustness of the Fe(Se,Te) system to irradiation-induced damage makes it a promising compound for the fabrication of magnets in high-energy accelerators.
Genetics Home Reference: tarsal-carpal coalition syndrome
... Belmonte JC, Choe S. Structural basis of BMP signalling inhibition by the cystine knot protein Noggin. Nature. 2002 ... Links Data Files & API Site Map Subscribe Customer Support USA.gov Copyright Privacy Accessibility FOIA Viewers & Players ...
Solid Foods: How to Get Your Baby Started
... nutritional interventions. The Journal of Allergy and Clinical Immunology: In Practice. 2013;1:29. For consumers: Seven ... allergic diseases. The Journal of Allergy and Clinical Immunology. 2013;131:78. Kiefte-de Jong JC, et ...
Genetics Home Reference: malonyl-CoA decarboxylase deficiency
... decarboxylase malonic aciduria malonyl-coenzyme A decarboxylase deficiency MCD deficiency Related Information How are genetic conditions and ... Morrell JC, Wanders RJ, Matalon R, Gould SJ. MCD encodes peroxisomal and cytoplasmic forms of malonyl-CoA ...
Prenatal care in your second trimester
... SG, Niebyl JR, Simpson JL, et al, eds. Obstetrics: Normal and Problem Pregnancies . 7th ed. Philadelphia, PA: ... JC, Hobel CJ, eds. Hacker & Moore's Essentials of Obstetrics and Gynecology . 6th ed. Philadelphia, PA: Elsevier; 2016: ...
Psychoanalytic Criticism and Teaching Shakespeare.
ERIC Educational Resources Information Center
Wheeler, Richard P.
1987-01-01
Presents a brief overview of previous psychoanalytically based theories of Shakespeare's plays, particularly "Hamlet," and defends the notion of introducing undergraduates to psychoanalytically based criticism because of the insights it may give students into their own lives. (JC)
The Use of Ethnographic Methods in Educational Evaluation
ERIC Educational Resources Information Center
Wilson, Stephen
1977-01-01
By treating a school as a subculture, the Center for New Schools hopes to use the techniques of anthropology to elucidate behavioral problems which may be keeping school members from achieving their goals. (JC)
... 2016:chap 44. Ellenson LH, Pirog EC. The female genital tract. In: Kumar V, Abbas AK, Aster JC, eds. Robbins and Cotran Pathologic Basis of Disease . 9th ed. Philadelphia, ... of the female pelvis. In: Wein AJ, Kavoussi LR, Partin AW, ...
"Why are Your Kids Writing during Reading Time?"
ERIC Educational Resources Information Center
Harp, Bill
1987-01-01
Presents a hypothetical situation of an elementary school principal's concern at students writing during reading time, and offers a possible teacher's response with information about the direct tie between writing and reading improvement. (JC)
... the autonomic nervous system. This is the part of the nervous system that is not under your control. Sweating is ... Skin layers References Chelimsky T, Chelimsky G. Disorders of the autonomic nervous system. In: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy ...
NASA Astrophysics Data System (ADS)
Wassermann, Jérôme; Sabroux, Jean-Christophe; Richon, Patrick; Pontreau, Sébastien; Guillon, Sophie; Pili, Eric
2010-05-01
The Roselend tunnel was drilled in the fifties by blasting in the micashists, granites and gneisses of the Méraillet massif (French Alps). It is situated on the shore of the Roselend reservoir Lake near its dam. Several tectonic shear fractures related to the Alpine orogeny intersect the dead end tunnel (with length of 128 m and section about 2 m), indeed the fracture density varies from 0.45 to 1 fracture per meter along the tunnel (Dezayes and Villemin 2002). Some fractures are partially or totally filled with secondary minerals. The flow rates of percolating water through the fractured medium are seasonal dependent. Large fractures drain a large fluid volume unlike small ones that drain limited fluid volume (Patriarche et al. 2007). The Roselend underground laboratory allows the study of the geochemical and geophysical responses of a fractured rock mass to periodic sollicitations due to water level variations of the nearby Roselend reservoir Lake. The tunnel was instrumented in the nineties to understand the relationship between radon (Rn-222) concentration and water level variations of the Roselend reservoir Lake (Trique et al. 1999). In order to characterize the geometry and the extent of the EDZ, core drilling and permeability measurements through pneumatic testing are performed along the Roselend tunnel. Drilled core analysis consists of direct observations at a macroscopic scale of fractures (density of fractures from EDZ) and also at a microscopic scale via thin sections. Method of pressure build-up in wells (Jakubick and Franz 1993, Bossart et al. 2002) is used to determine permeability profile along each borehole and hence to precise the extent and geometry of the EDZ. A strong correlation is observed between permeability profiles and the density of fractures estimated from core analysis. The extent of the EDZ appears to be about one tunnel radius i.e. one meter around the tunnel corridor. Another experiment consisting of continuous differential pressure measurements between an obturated borehole and the tunnel is conducted to monitor the possible modifications of the transport properties of the EDZ due to hydraulical and/or mechanical sollicitations of the nearby Roselend reservoir lake. As radon level is controlled by emanation and transport path through the medium. The observed bursts of radon should be due to changes of the radon transport properties (Trique et al. 1999) of the EDZ. A correlation between the differential pressure variations and radon bursts is clearly observed. Radon bursts seem to be related to overpressure events that take place in the instrumented borehole. Which external sollicitations, hydraulical or mechanical, or both, induce such a behaviour? References Bossart, P., Meier, P. M., Moeri, A., Trick, T., and J.-C. Mayor (2002). Geological and hydraulic characterisation of the excavation disturbed zone in the Opalinus Clay of the Mont Terri Rock Laboratory, Engineering Geology, 66, 19-38. Dezayes, C., and T. Villemin (2002). Etat de la fracturation dans la galerie CEA de Roselend et analyse de la déformation cassante dans le massif du Méraillet, technical report, Lab. de Geodyn. de Chaisnes Alp., Univ. de Savoie, Savoie, France. Jakubick, A. T., and T. Franz (1993). Vacuum testing of the permeability of the excavation damaged zone, Rock Mech. Rock Engng., 26(2), 165-182. Patriarche, D., Pili, E., Adler, P. M., and J.-F. Thovert (2007). Stereological analysis of fractures in the Roselend tunnel and permeability determination, Water Resour. Res., 43, W09421. Richon, P., Perrier, F., Sabroux, J.-C., Trique, M., Ferry, C., Voisin, V., and E. Pili (2004). Spatial and time variations of radon-222 concentration in the atmosphere of a dead-end horizontal tunnel, J. Environ. Radioact., 78, 179-198. Richon, P., Perrier, F., Pili, E., and J.-C. Sabroux (2009). Detectability and significance of the 12hr barometric tide in radon-222 signal, dripwater flow rate, air temperature and carbon dioxide concentration in an underground tunnel, Geophys. J. Int., 176, 683-694.
Genetics Home Reference: familial lipoprotein lipase deficiency
... 1 millimeter in diameter), but individual xanthomas can cluster together to form larger patches. They are generally ... JC, Méndez-González J, Blanco-Vaca F. Molecular analysis of chylomicronemia in a clinical laboratory setting: diagnosis ...
Positive Stereotyping: The Cultural Relativist in the Classroom
ERIC Educational Resources Information Center
Kleinfeld, Judith
1976-01-01
While cultural relativism has been an important corrective to the ethnocentrism of the past, teachers have often vulgarized this viewpoint to mean that no standards they hold can be applied to American Indian students. (Author/JC)
Oyster shell conveyor used to lift shells from the dock ...
Oyster shell conveyor used to lift shells from the dock into the receiving room housed in the 1965 concrete block addition. - J.C. Lore Oyster House, 14430 Solomons Island Road, Solomons, Calvert County, MD
Construction and Validation of a Scale to Measure Maslow's Concept of Self-Actualization
ERIC Educational Resources Information Center
Jones, Kenneth Melvin; Randolph, Daniel Lee
1978-01-01
Designed to measure self-actualization as defined by Abraham Maslow, the Jones Self Actualizing Scale, as assessed in this study, possesses content validity, reliability, and a number of other positive characteristics. (JC)
A School in Siberia: 14-Year-Olds Take University Math Course.
ERIC Educational Resources Information Center
Bogdanovsky, Georgy
1978-01-01
Ordinary students (n=40) are participating in a Soviet experiment wherein they are taught by well-known scientists and specialists in a math-intensive course comparable to that taught at the Kiev University. (JC)
... v652.pdf . Accessed May 16, 2016. Dinakar P. Principles of pain management. In: Daroff RB, Jankovic J, Mazziotta JC, eds. Bradley's Neurology in Clinical Practice . 7th ed. Philadelphia, PA: Elsevier; 2015:chap 54. Nikolajsen L, Springer JS, Haroutiunian S. Phantom ...
Hu, C H; Zhuang, X J; Wei, Y M; Zhang, M; Lu, S S; Lu, Y Q; Yang, X G; Lu, K H
Poor reproductivity hampers the commercialization of cryopreserved boar semen. This study was to determine the differences in the sperm mitochondrial function between boar and bull semen at different cryopreservation stages. Boar and bull fresh, equilibrated, and frozen-thawed spermatozoa were evaluated for mitochondrial function using JC-1 under a fluorescent microscope. Bull and boar percentage of spermatozoa staining green (PSSG) showed no difference between fresh and equilibrated semen (P> 0.05). However, frozen-thawed bull and boar semen demonstrated significantly higher PSSG (P < 0.01) than fresh and equilibrated semen. Frozen-thawed boar semen represented a significantly higher PSSG (P < 0.01) than bull semen. Negative cryopreservation influence on boar and bull spermatozoa was not significantly produced by pre-freezing procedures, but rather by freezing and thawing. Cryopreservation has more pronounced negative effects on boar than on bull spermatozoa, which partly explains lagged commercialization of frozen boar semen.
Sanchez-Quintana, Ana; Breña-Atienza, Joaquín; Marrero-Santos, Carmen; Alvarez-Acosta, Luis
2013-08-05
We describe a case of progressive multifocal leucoencephalopathy (PML) in a 39-year-old patient diagnosed with chronic lymphocytic leukaemia (CLL) who underwent two allogenic matched-sibling stem cell transplantations. PML was confirmed just after the first transplantation with cerebral MRI and by PCR in the cerebrospinal fluid. After immunosuppression withdrawal and cidofovir treatment, he achieved a reversal of clinical symptoms, John Cunningham (JC) virus positivity and MRI lesions regression. He remained asymptomatic for 5 years with no signs of infection activity, even though he received three new chemotherapy regimens due to a CLL relapse. However, after the second stem cell transplantation, new neurological symptoms began and a reactivation of the JC virus infection was detected. This time, treatment with mefloquine was started, but he experienced a progressive neurological deterioration and died 1 month after the symptoms began.
Strong Flux Pinning of Nano-Sized Ysz Particles in Ybco Films Prepared by Mod Method
NASA Astrophysics Data System (ADS)
Ye, S.; Suo, H. L.; Liu, M.; Tang, X.; Wu, Z. P.; Zhao, Y.; Zhou, M. L.
The YBCO films with doped YSZ nanoparticles have been prepared successfully by metal organic doepositon method using trifluoroacetates (TFA-MOD) through dissolving Zr organic salt into the YBCO precursor solution. The doped films have well in-plane and out-plane textures detected by both XRD Φ-scan and ω-scan. The YSZ nanoparticles with the size of about 5 ~ 15 nm were observed on the surface of the YBCO films using both FE-SEM and TEM. By comparing the superconducting properties, it was found that the doped YBCO films had lower Tc than that of undoped YBCO films. However, as increasing the applied magnetic field, Jc of the doped YBCO films were much better than that of undoped one. The Jc was as higher as 2.5 times than that of undoped YBCO film at 77 K and 1 T applied field.
Akiyoshi, Takeshi; Matzno, Sumio; Sakai, Mika; Okamura, Noboru; Matsuyama, Kenji
2009-12-01
We tried to clarify the cytotoxic mechanism of VK(3) using the breast cancer cell line MCF-7. Cytotoxicity was measured via intracellular esterase activity. DNA fragmentation was assessed by agarose gel electrophoresis. JC-1 staining was applied to measure mitochondrial dysfunction. Caspase activation and reactive oxidative species (ROS) generation were also measured. VK(3) exhibited cytotoxicity that caused DNA fragmentation in MCF-7 cells with an IC(50) of 14.2 microM. JC-1 staining revealed that VK(3) caused mitochondrial dysfunction including a disappearance of mitochondrial membrane potential. Additional investigation showed that the mitochondrial damage was induced by the generation of ROS and the subsequent activation of caspase-7 and -9. Our findings demonstrate that VK(3)-induced apoptosis is selectively initiated by the mitochondria-related pathway and might be useful in breast cancer chemotherapy.
Pharmacological cdk inhibitor R-Roscovitine suppresses JC virus proliferation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Orba, Yasuko; Laboratory of Molecular and Cellular Pathology, Hokkaido University Graduate School of Medicine, N15, W7, Kita-ku, 060-8638, Sapporo; Research Fellow of the Japan Society for the Promotion of Science
2008-01-05
The human Polyomavirus JC virus (JCV) utilizes cellular proteins for viral replication and transcription in the host cell nucleus. These cellular proteins represent potential targets for antiviral drugs against the JCV. In this study, we examined the antiviral effects of the pharmacological cyclin-dependent kinase (cdk) inhibitor R-Roscovitine, which has been shown to have antiviral activity against other viruses. We found that Roscovitine significantly inhibited the viral production and cytopathic effects of the JCV in a JCV-infected cell line. Roscovitine attenuated the transcriptional activity of JCV late genes, but not early genes, and also prevented viral replication via inhibiting phosphorylation ofmore » the viral early protein, large T antigen. These data suggest that the JCV requires cdks to transcribe late genes and to replicate its own DNA. That Roscovitine exhibited antiviral activity in JCV-infected cells suggests that Roscovitine might have therapeutic utility in the treatment of progressive multifocal leukoencephalopathy (PML)« less
Vilkin, Alex; Niv, Yaron
2011-04-01
Incorporation of viral DNA may interfere with the normal sequence of human DNA bases on the genetic level or cause secondary epigenetic changes such as gene promoter methylation or histone acetylation. Colorectal cancer (CRC) is the second leading cause of cancer mortality in the USA. Chromosomal instability (CIN) was established as the key mechanism in cancer development. Later, it was found that CRC results not only from the progressive accumulation of genetic alterations but also from epigenetic changes. JC virus (JCV) is a candidate etiologic factor in sporadic CRC. It may act by stabilizing β-catenin, facilitating its entrance to the cell nucleus, initialing proliferation and cancer development. Diploid CRC cell lines transfected with JCV-containing plasmids developed CIN. This result provides direct experimental evidence for the ability of JCV T-Ag to induce CIN in the genome of colonic epithelial cells. The association of CRC hMLH1 methylation and tumor positivity for JCV was recently documented. JC virus T-Ag DNA sequences were found in 77% of CRCs and are associated with promoter methylation of multiple genes. hMLH1 was methylated in 25 out of 80 CRC patients positive for T-Ag (31%) in comparison with only one out of 11 T-Ag negative cases (9%). Thus, JCV can mediate both CIN and aberrant methylation in CRC. Like other viruses, chronic infection with JCV may induce CRC by different mechanisms which should be further investigated. Thus, gene promoter methylation induced by JCV may be an important process in CRC and the polyp-carcinoma sequence.
Armstrong, Joanne C; Kozhimannil, Katy B; McDermott, Patricia; Saade, George R; Srinivas, Sindhu K
2016-02-01
This report describes the development of a measure of low-risk cesarean delivery by the Society for Maternal-Fetal Medicine (SMFM). Safely lowering the cesarean delivery rate is a priority for maternity care clinicians and health care delivery systems. Therefore, hospital quality assurance programs are increasingly tracking cesarean delivery rates among low-risk pregnancies. Two commonly used definitions of "low risk" are available, the Joint Commission (JC) and the Agency for Healthcare Research and Quality (AHRQ) measures, but these measures are not clinically comprehensive. We sought to refine the definition of the low-risk cesarean delivery rate to enhance the validity of the metric for quality measurement. We created this refined definition-called the SMFM definition-and compared it to the JC and AHRQ measures using claims-based data from the 2011 Nationwide Inpatient Sample of >863,000 births in 612 hospitals. Using these definitions, we calculated means and interquartile ranges (25th-75th percentile range) for hospital low-risk cesarean delivery rates, stratified by hospital size, teaching status, urban/rural location, and payer mix. Across all hospitals, the mean low-risk cesarean delivery rate was lowest for the SMFM definition (12.65%), but not substantially different from the JC and AHRQ measures (13.12% and 13.29%, respectively). We empirically examined the SMFM definition to ensure its validity and utility. This refined definition performs similarly to existing measures and has the added advantage of clinical perspective, enhanced face validity, and ease of use. Copyright © 2016 Elsevier Inc. All rights reserved.
Genetics Home Reference: Adams-Oliver syndrome
... Baveja R, Silva ES, Dixon J, Leon EL, Solomon BD, Glusman G, Niederhuber JE, Roach JC, Patel MS. Mutations in NOTCH1 cause Adams-Oliver syndrome. Am J Hum Genet. 2014 Sep 4;95(3):275-84. doi: 10.1016/j. ...
DNA ARRAYS: TECHNOLOGY, OPTIONS AND TOXOCOLOGICAL APPLICATIONS
DNA arrays: technology, options and toxicological applications.
Rockett JC, Dix DJ.
Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, NC 27711, USA. rockett.john@epa.gov
The hu...
Claim and Adjustment Letters: Theory Versus Practice and Legal Implications.
ERIC Educational Resources Information Center
Aalberts, Roberts J.; Krajewski, Lorraine A.
1987-01-01
Addresses the reasons companies respond to consumer complaints, analyzes 35 business letters responding to complaints and the ways in which the letters deviate from textbook recommendations, and examines legal theories applicable to claim adjustment letters. (JC)
Elementary Principals: How Do We Compare with Middle Managers in Industry?
ERIC Educational Resources Information Center
Alkire, Gary F.; Dorin, Patrick C.
1979-01-01
A study conducted at the University of Minnesota (1977) suggests there is no significant difference in the activities of elementary school principals and industrial managers when it comes to planning, investigating, coordinating, and evaluating activities. (JC)
On Dramatic Instruction: Towards a Taxonomy of Methods.
ERIC Educational Resources Information Center
Courtney, Richard
1987-01-01
Examines the many possible methods used by instructors who work with dramatic action: in educational drama, drama therapy, social drama, and theater. Discusses an emergent taxonomy whereby instructors choose either spontaneous/formal, overt/covert/, or intrinsic/extrinsic methods. (JC)
NASA Astrophysics Data System (ADS)
Pickering, Juliet C.; Nave, Gillian; Liggins, Florence; Clear, Christian; Ruffoni, Matthew; Sansonetti, Craig
2015-08-01
We present new laboratory spectroscopic measurements to produce atomic data for astrophysically important species: neutral, singly and doubly ionised iron group elements.We use high resolution Fourier Transform Spectrometry (FTS) (resolving power up to 2x106 at 200nm) to measure atomic spectra, giving accurate line wavelengths (to a few parts in 108), atomic energy levels, hyperfine structure splitting and log gfs (accurate to a few %) (Ruffoni et al this meeting). These data are vital for astrophysical spectral analyses for: line identification, spectrum synthesis, elemental abundance determinations [eg 1], and disentangling of blends etc. It is not possible to theoretically calculate these atomic data to the accuracy needed for modern astrophysics applications.At Imperial College we have a unique visible-VUV FT spectrometer with short wavelength cut-off of 135nm. We supplement FTS data at shorter wavelengths with spectra recorded on the NIST 10.7m grating spectrograph (with phosphor image or photographic plates) and at longer wavelengths in the IR we use the NIST IR FT spectrometer.An elemental spectrum may contain thousands of spectral lines from the IR to VUV. We use these wavelengths to correct known atomic energy levels, and search for new atomic levels. The result is a classified linelist and accurate atomic energy levels.We present progress on iron group element atomic energy levels and wavelengths for V I and V II [2,3], Co III [4], Cr I, Mn I and Mn II, and Ni II.This work is supported by STFC(UK), The Leverhulme Trust, The Royal Society and NASA.References[1] Bergemann M, Pickering JC & Gehren T,“NLTE analysis of Co I/Co II lines in spectra of cool stars with new laboratory hyperfine splitting constants",MNRAS 401(2) 1334 (2010)[2] Thorne AP, Pickering JC & Semeniuk J,“The spectrum and term analysis of V II”, ApJS 207,13 (2013)[3] Thorne AP, Pickering JC & Semeniuk J,“The spectrum and term analysis of V I",ApJS 192,11 (2011)[4] Smillie DG, Pickering JC, Nave G & Smith PL,“The Spectrum and Term Analysis of Co III Measured using Fourier Transform and Grating Spectroscopy”,ApJS submitted
NASA Astrophysics Data System (ADS)
Zellers, S.; Cowan, E. A.; Davies, M. H.
2014-12-01
Gulf of Alaska sediments contain distinct, low-diversity assemblages of benthic and planktic foraminifera, whose distribution is a function of food availability, water mass properties, ice proximity, transport/deposition, predation, and taphonomic processes. Spatial and temporal changes in diversity reflect these processes and provide insight into this margin's history. Two quantitative techniques are integrated to define and characterize benthic foraminferal biozones in Gulf of Alaska sediment core samples collected by the R/V Maurice Ewing in 2004 at shelf site EW0408-79JC (59.53° N, 141.76° W, 158 m depth), and slope site EW0408-85JC (59.56° N, 144.15° W, 682 m depth). Sediments date from the end of the most recent glaciation (diamict in 85JC) to the present (bioturbated, silty clay at both sites). We apply SHE analysis, a graphical, iterative technique, based on diversity trends in a plot of ln E vs. ln N, where E is species evenness and N is cumulative number of specimens. In each step, the plot is examined for the first change in slope between successive samples, representing a change in diversity. At this point a boundary is defined, samples before the break are removed, and the analysis is repeated until all samples are analyzed. Data are further analyzed using an unmixing algorithm known as polytopic vector analyses. This technique defines a small number of orthogonal end members that explain a majority of the variance, thus reducing data complexity and aiding interpretation. SHE-analysis of benthic foraminiferal data defines eighteen informal abundance biozones. Polytopic vector analyses indicate that the faunal assemblages reflect mixtures of up to seven distinct biofacies: outer neritic (2), upper bathyal (2), reduced oxygen (2), and inner neritic. Rapid changes in faunal diversity correspond with increased sedimentation rates, especially during the end of the most recent glaciation (17 to 16 ka). The same relationship occurs over the last 1000 years at the shelf site. Where the cores overlap in age, many more assemblage boundaries occur in the shelf core, suggesting a comparatively dynamic environment relative to the slope. The least amount of diversity change corresponds with the laminated intervals in 85JC, coincident with high productivity and development of anoxia during regional deglaciation.
Ran, Du; Hu, Chang-Sheng; Yang, Zhen-Biao
2016-01-01
We study the entanglement transfer from a two-mode continuous variable system (initially in the two-mode SU(2) cat states) to a couple of discrete two-state systems (initially in an arbitrary mixed state), by use of the resonant Jaynes-Cummings (JC) interaction. We first quantitatively connect the entanglement transfer to non-Gaussianity of the two-mode SU(2) cat states and find a positive correlation between them. We then investigate the behaviors of the entanglement transfer and find that it is dependent on the initial state of the discrete systems. We also find that the largest possible value of the transferred entanglement exhibits a variety of behaviors for different photon number as well as for the phase angle of the two-mode SU(2) cat states. We finally consider the influences of the noise on the transferred entanglement. PMID:27553881
The power of sex: some reflections on the Caldwell's "African sexuality" thesis.
Heald, S
1995-01-01
J.C. Caldwell et al. would like to construct a model of African society which is capable of generating ideas about the nature of sex behavior. Such a model would explain population and fertility patterns as well as those relevant to the spread of HIV. However, the author is concerned with the values and morality of sexuality in East Africa. She stresses that her intention is not to comprehensively rebut Caldwell's work, but simply to reflect upon the nature of sexuality in East Africa while drawing upon the works of Caldwell. The author's goal is to highlight areas of disagreement and to present and re-present evidence from the ethnographic record in order to move toward more satisfactory descriptive criteria with which to begin to think, as an anthropologist, about sexual morality in Africa. Sections consider Africa's alternative civilization, the lineage model, respect, the metaphor of mingling, affection, and alliance and contract.
Spectroscopic Factors From the Single Neutron Pickup Reaction ^64Zn(d,t)
NASA Astrophysics Data System (ADS)
Leach, Kyle; Garrett, P. E.; Demand, G. A.; Finlay, P.; Green, K. L.; Phillips, A. A.; Sumithrarachchi, C. S.; Svensson, C. E.; Triambak, S.; Ball, G. C.; Faestermann, T.; Krücken, R.; Wirth, H.-F.; Herten-Berger, R.
2008-10-01
A great deal of attention has recently been paid towards high precision superallowed β-decay Ft values. With the availability of extremely high precision (<0.1%) experimental data, the precision on Ft is now limited by the ˜1% theoretical corrections.ootnotetextI.S. Towner and J.C. Hardy, Phys. Rev. C 77, 025501 (2008). This limitation is most evident in heavier superallowed nuclei (e.g. ^62Ga) where the isospin-symmetry-breaking correction calculations become more difficult due to the truncated model space. Experimental data is needed to help constrain input parameters for these calculations, and thus experimental spectroscopic factors for these nuclei are important. Preliminary results from the single-nucleon-transfer reaction ^64Zn(d,t)^63Zn will be presented, and the implications for calculations of isospin-symmetry breaking in the superallowed &+circ; decay of ^62Ga will be discussed.
NASA Astrophysics Data System (ADS)
Ning, Fangkun; Jia, Weitao; Hou, Jian; Chen, Xingrui; Le, Qichi
2018-05-01
Various fracture criteria, especially Johnson and Cook (J-C) model and (normalized) Cockcroft and Latham (C-L) criterion were contrasted and discussed. Based on normalized C-L criterion, adopted in this paper, FE simulation was carried out and hot rolling experiments under temperature range of 200 °C–350 °C, rolling reduction rate of 25%–40% and rolling speed from 7–21 r/min was implemented. The microstructure was observed by optical microscope and damage values of simulation results were contrasted with the length of cracks on diverse parameters. The results show that the plate generated less edge cracks and the microstructure emerged slight shear bands and fine dynamic recrystallization grains rolled at 350 °C, 40% reduction and 14 r/min. The edge cracks pre-criterion model was obtained combined with Zener-Hollomon equation and deformation activation energy.
Experimental analysis of a TEM plane transmission line for DNA studies at 900 MHz EM fields
NASA Astrophysics Data System (ADS)
Belloni, F.; Doria, D.; Lorusso, A.; Nassisi, V.; Velardi, L.; Alifano, P.; Monaco, C.; Talà, A.; Tredici, M.; Rainò, A.
2006-07-01
A suitable plane transmission line was developed and its behaviour analysed at 900 MHz radiofrequency fields to study DNA mutability and the repair of micro-organisms. In this work, utilizing such a device, we investigated the behaviour of DNA mutability and repair of Escherichia coli strains. The transmission line was very simple and versatile in changing its characteristic resistance and field intensity by varying its sizes. In the absence of cell samples inside the transmission line, the relative modulation of the electric and/or magnetic field was ±31% with respect to the mean values, allowing the processing of more samples at different exposure fields in a single run. A slight decrease in spontaneous mutability to rifampicin-resistance of the E. coli JC411 strain was demonstrated in mismatch-repair proficient samples exposed to the radio-frequency fields during their growth on solid medium.
Glassy vortex behavior in superconducting SrPd2Ge2 single crystals
NASA Astrophysics Data System (ADS)
Sung, N. H.; Jo, Y. J.; Cho, B. K.
2012-07-01
In this study we report the vortex-glass behavior of superconducting ternary germanide SrPd2Ge2 single crystals with a ThCr2Si2-type structure. We observed flux trapping and its nonexponential decay with time after the magnetic field was turned off at T = 2 K. In addition, we found that the diamagnetism in the zero field cooling (ZFC) mode below Tc was irreversible, depending on the temperature and field history, whereas the diamagnetism in the field-cooled warming (FCW) mode was reversible if the applied magnetic field was parallel to the c-axis. An irreversibility line Tr(H) was determined by the ZFC and FCW measurements at various magnetic fields, and the temperature dependence of Tr(H) was found to agree with the de Almeida-Thouless relation, H = H0[1-Tr(H)/Tc(0)]γ, where γ = 3/2. Including these vortex-glass behaviors, we discuss the critical current density, Jc(T), determined from isothermal magnetization measurements at various temperatures, and the pinning potential, determined from the slope of an Arrhenius plot, lnR(T,B) versus 1/T.
Eddy damping effect of additional conductors in superconducting levitation systems
NASA Astrophysics Data System (ADS)
Jiang, Zhao-Fei; Gou, Xiao-Fan
2015-12-01
Passive superconducting levitation systems consisting of a high temperature superconductor (HTSC) and a permanent magnet (PM) have demonstrated several fascinating applications such as the maglev system, flywheel energy storage. Generally, for the HTSC-PM levitation system, the HTSC with higher critical current density Jc can obtain larger magnetic force to make the PM levitate over the HTSC (or suspended below the HTSC), however, the process of the vibration of the levitated PM, provides very limited inherent damping (essentially hysteresis). To improve the dynamic stability of the levitated PM, eddy damping of additional conductors can be considered as the most simple and effective approach. In this article, for the HTSC-PM levitation system with an additional copper damper attached to the HTSC, we numerically and comprehensively investigated the damping coefficient c, damping ratio, Joule heating of the copper damper, and the vibration frequency of the PM as well. Furthermore, we comparatively studied four different arrangements of the copper damper, on the comprehensive analyzed the damping effect, efficiency (defined by c/VCu, in which VCu is the volume of the damper) and Joule heating, and finally presented the most advisable arrangement.
Multifilament Superconducting Wire Based on NbTi Alloy in a Combined Copper/Copper-Nickel Matrix
NASA Astrophysics Data System (ADS)
Vedernikov, G. P.; Shikov, A. K.; Potanina, L. V.; Gubkin, I. N.; Scherbakova, O. V.; Salunin, N. I.; Korpusov, V. U.; Novikov, S. I.; Novikov, M. S.
2004-06-01
Model fine filament superconducting 0.65 mm wire based on NbTi alloy, intended for operating in fields having sweep rate from 1 up to 4 T/s, has been developed and manufactured by Bochvar Institute (VNIINM). The wire was fabricated by a single stacking method. Each filament was surrounded by a matrix of commercial MN-5 alloy (Cu-5wt.%Ni). The effects of heat treatment regimes, and twist pitches within the range of 3.5 - 8 mm on Jc of the strand were investigated at fields of 2-8 T. The critical current density is more than 2700 A/mm2 at 5 T, 4.2 K. The magnetization of wire has been measured by a vibrating magnetometer at field amplitude up to ± 3 T. Hysteresis losses and effective diameter were calculated. Total and coupling losses have been determined by Fitz method on strand magnetization at fields, varying in trapezoidal mode. It was shown that the wire of this type is of potential application for the use in the magnets of the GSI-type accelerator to be constructed in Germany.