The spin Hall effect (SHE), induced by spin-orbit interaction in nonmagnetic materials, is one of the promising phenomena for conversion between charge and spin currents in spintronic devices. The ...spin Hall (SH) angle is the characteristic parameter of this conversion. We have performed experiments of the conversion from spin into charge currents by the SHE in lateral spin valve structures. We present experimental results on the extrinsic SHEs induced by doping nonmagnetic metals, Cu or Ag, with impurities having a large spin-orbit coupling, Bi or Pb, as well as results on the intrinsic SHE of Au. The SH angle induced by Bi in Cu or Ag is negative and particularly large for Bi in Cu, 10 times larger than the intrinsic SH angle in Au. We also observed a large SH angle for CuPb, but the SHE signal disappeared in a few days. Such an aging effect could be related to a fast mobility of Pb in Cu and has not been observed in CuBi alloys.
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Number–size distributions of aerosol particles with diameters of 10–500 nm in the marine boundary layer were observed continually onboard the R/V Hakuho Maru over the equatorial and subtropical North ...Pacific and South Pacific during December 2011–March 2012. Number–size distributions over each area were parameterized using a sum of up to three lognormal functions. Bi-modal size distributions with peak diameters at 30–80 nm (Aitken mode) and 100–200 nm (accumulation mode) were observed frequently. Larger peak diameters of Aitken and accumulation modes were observed over the eastern equator, where 5-day backward trajectories showed that the air masses had derived from high-chlorophyll oceanic regions without precipitation. Smaller peak diameters and low concentrations were often observed over the North Pacific. The trajectories show that such air mass originated from oceanic regions with less chlorophyll, exhibiting high precipitation frequency. New particle formation (NPF) events have often been observed over the mid-latitude eastern South Pacific with a low condensation sink (CS) and some dimethyl sulfide, although none was observed over the equator, where CS was higher. The lesser CS condition at NPF events was mostly correlated with local precipitation or precipitation along the trajectories within 1 day. These results suggest that differences of the number–size distribution and occasions of NPF events among sea areas most closely accord with precipitation along the trajectories.
•Aerosol number–size distributions were observed over the North and South Pacific.•Distributions over respective areas were parameterized using lognormal fitting.•Bimodal distributions of larger peaks were observed over the eastern equator.•New particle formation occurred often at eastern South Pacific mid-latitudes.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
In some materials the competition between superconductivity and magnetism brings about a variety of unique phenomena such as the coexistence of superconductivity and magnetism in heavy-fermion ...superconductors or spin-triplet supercurrent in ferromagnetic Josephson junctions. Recent observations of spin-charge separation in a lateral spin valve with a superconductor evidence that these remarkable properties are applicable to spintronics, although there are still few works exploring this possibility. Here, we report the experimental observation of the quasiparticle-mediated spin Hall effect in a superconductor, NbN. This compound exhibits the inverse spin Hall (ISH) effect even below the superconducting transition temperature. Surprisingly, the ISH signal increases by more than 2,000 times compared with that in the normal state with a decrease of the injected spin current. The effect disappears when the distance between the voltage probes becomes larger than the charge imbalance length, corroborating that the huge ISH signals measured are mediated by quasiparticles.
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IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SBMB, UL, UM, UPUK
Various radionuclides including fission products and heavy nuclides were released into the environment during the Fukushima Daiichi Nuclear Power Station (FDNPS) accident. The dissolution followed by ...migration of deposited radionuclides of Cs, Sr and U on soils could take place to the local environment. Therefore, it is necessary to determine sorption-desorption coefficients of U in soil-water system around the FDNPS from a migration viewpoint. The determination of sorption coefficient Kd(S) as well as desorption coefficient Kd(D) for U has been carried out in the present study using a laboratory batch method. Stable U was used for sorption from simulated ground water onto contaminated soil samples collected from Okuma Town, Fukushima. Different soil parameters were measured to understand their effects on sorption and desorption processes. The obtained Kd(S) and Kd(D) values of U were compared with values of Kd(S) and Kd(D) of Cs and Sr and Kd(S)–U in known Fukushima accident contaminated soils reported in the literature for better understanding. It was observed that Kd(S)–U varied from 160 to 5100 L/kg, whereas Kd(D)-U ranged from 200 to 11000 L/kg. Kd(D) was higher than Kd(S) for U in these soils implying irreversibility of the sorption process. Pearson's correlation of Kd(S) values suggested that U sorption is affected by various soil parameters. However, desorption is decided by the nature of U species formed in sorption process and soil parameters like pH, presence of carbonates, Ca ions, clay minerals etc. to some extent. The comparison between Kd(S) and Kd(D) values for Cs, Sr and U revealed that unsorbed Sr could migrate farther than unsorbed Cs or U under the present experimental conditions. Both sorption and desorption studies are of great importance to understand migration of metal ions from contaminated sites to local uncontaminated areas.
•Sorption-desorption studies of U were carried out on Okuma Town soil samples from Fukushima Prefecture.•Kd(S) values of Cs, Sr and U obtained between previous and present studies revealed Kd(S)–U > Kd(S)–Cs > Kd(S)–Sr.•Higher Kd values for U and Cs in the desorption than sorption showed irreversibility of U and Cs sorption on soils.•Pearson's correlation of Kd values with soil parameters helped to understand the sorption-desorption processes.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In the present study, 137Cs and 238U activity concentrations, 234U/238U activity ratio, and 235U/238U isotope ratio were measured in fifteen soil samples collected from the exclusion zone around the ...Fukushima Daiichi Nuclear Power Station (FDNPS). The 137Cs activity concentrations of Fukushima-accident contaminated soil samples ranged from 29.9 to 4780 kBq kg−1 with a mean of 2007 kBq kg−1. On the other hand, the 238U activity concentrations of these soil samples ranged from 5.2 to 22.4 Bq kg−1 with a mean of 13.2 Bq kg−1. The activity ratios of 234U/238U ranged from 0.973 to 1.023. The 235U/238U isotope ratios of these exclusion zone soil samples varied from 0.007246 to 0.007260, and they were similar to the natural terrestrial ratio confirming the natural origin. Using isotope dilution technique, the 235U/137Cs activity ratio was theoretically estimated for highly 137Cs contaminated soil samples from Fukushima exclusion zone ranged from 5.01 × 10−8 - 6.16 × 10−7 with a mean value of 2.51 × 10−7.
•137Cs activity concentration ranged from 29.9 to 4780 kBq kg−1.•The activity ratio of 234U/238U were in the range of 0.973–1.023.•The 235U/238U isotope ratios indicate natural in origin for Fukushima soil samples.•The 235U/137Cs activity ratio ranged from 5.01 × 10−8 - 6.16 × 10−7 for Fukushima exclusion zone soil samples.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
ABSTRACT
We search for the signature of cosmological shocks in stacked gas pressure profiles of galaxy clusters using data from the South Pole Telescope (SPT). Specifically, we stack the latest ...Compton-y maps from the 2500 deg2 SPT-SZ survey on the locations of clusters identified in that same data set. The sample contains 516 clusters with mean mass $\langle M_{\rm 200m}\rangle = 10^{14.9} \, {\rm M}_\odot$ and redshift 〈z〉 = 0.55. We analyse in parallel a set of zoom-in hydrodynamical simulations from the three hundred project. The SPT-SZ data show two features: (i) a pressure deficit at R/R200m = 1.08 ± 0.09, measured at 3.1σ significance and not observed in the simulations, and; (ii) a sharp decrease in pressure at R/R200m = 4.58 ± 1.24 at 2.0σ significance. The pressure deficit is qualitatively consistent with a shock-induced thermal non-equilibrium between electrons and ions, and the second feature is consistent with accretion shocks seen in previous studies. We split the cluster sample by redshift and mass, and find both features exist in all cases. There are also no significant differences in features along and across the cluster major axis, whose orientation roughly points towards filamentary structure. As a consistency test, we also analyse clusters from the Planck and Atacama Cosmology Telescope Polarimeter surveys and find quantitatively similar features in the pressure profiles. Finally, we compare the accretion shock radius ($R_{\rm sh,\, acc}$) with existing measurements of the splashback radius (Rsp) for SPT-SZ and constrain the lower limit of the ratio, $R_{\rm sh,\, acc}/R_{\rm sp}\gt 2.16 \pm 0.59$.
A pilot survey in the Central Garhwal Himalayan region, India, assessed radon and thoron inhalation doses using RADUET, CR39 detectors during January to October 2013. Detectors were deployed for 95, ...101, and 92 days in winter, summer, and in the rainy season respectively. Highest
222
Rn concentration (260 ± 13 Bqm
−3
) was in cemented categories, followed by 170 ± 8 and 190 ± 10 Bqm
−3
in wood-stone dwellings. Wood-mud categories had lower levels (116 ± 6 to 128 ± 8 Bqm
−3
). Despite significant
222
Rn concentration, analysis of seasonal radiation exposures (EEC
Tn
and F
eq
) with short-lived decay products showed reduced doses in winter months ranging from 2.97 (± 0.31) to 6.91 (± 0.32) Bqm
−3
.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
We examine the effects of magnitude, colour and Lyα equivalent width (EW) on the spatial distribution of z ∼ 3 Lyman break galaxies (LBGs) and report significant differences in the two-point ...autocorrelation functions. The results are obtained using samples of ∼10 000-55 000 LBGs from the Canada-France-Hawaii Telescope Legacy Survey Deep Fields. We find that magnitude has a larger effect on the autocorrelation function amplitude on small scales ( 1
Mpc, the one-halo term) and that colour is more influential on large scales ( 1
Mpc, the two-halo term). We find the most significant differences between autocorrelation functions for LBGs with dominant net Lyα EW in absorption (aLBGs) and dominant net Lyα EW in emission (eLBGs) determined from 95 per cent pure samples of each population using a photometric technique calibrated from ∼1000 spectra. The aLBG autocorrelation function has a higher two-halo amplitude than the full LBG sample and has a one-halo term departure from a power-law fit near ∼1
Mpc, corresponding to the virial radii of M
DM ∼ 1013 M dark matter haloes. In contrast, the eLBG autocorrelation function has a one-halo term departure at ∼0.12
Mpc, suggesting parent haloes of M
DM ∼ 1011 M and a two-halo term that exhibits a curious 'hump' on intermediate scales that we localize to the faintest, bluest members. The aLBG-eLBG cross-correlation function exhibits an anticorrelation component that reinforces different physical locations for a significant fraction of aLBGs and eLBGs. We introduce a 'shell' model for the eLBG autocorrelation function and find that the form can be reproduced assuming that a significant fraction of eLBGs have a shell-like spatial distribution. Based on the analysis of all LBG subsamples, and considering the natural asymmetric distribution of LBGs on the colour-magnitude diagram, we conclude that aLBGs are more likely to reside in group-like environments hosting multiple luminous (i
′ < 26.4) LBGs whereas eLBGs are more likely to be found on group outskirts and in the field. Because Lyα is a tracer of several intrinsic properties, including morphology, the results presented here imply that the mechanisms behind the morphology-density relation at low redshift are in place at z ∼ 3 and that Lyα EW may be a key environment diagnostic. Finally, our results show that the LBG autocorrelation function amplitude is lower than the true average as a result of the spatial anticorrelation of the spectral types. This result holds broad consequences for all autocorrelation functions measured for any population that contains members residing in different environments as the average amplitude, and hence the inferred average dark matter mass, will always be underestimated.
We have measured spin Hall effects in spin glass metals, CuMnBi alloys, with the spin absorption method in the lateral spin valve structure. Far above the spin glass temperature T(g) where the ...magnetic moments of Mn impurities are randomly frozen, the spin Hall angle of a CuMnBi ternary alloy is as large as that of a CuBi binary alloy. Surprisingly, however, it starts to decrease at about 4T(g) and becomes as little as 7 times smaller at 0.5T(g). A similar tendency was also observed in anomalous Hall effects in the ternary alloys. We propose an explanation in terms of a simple model considering the relative dynamics between the localized moment and the conduction electron spin.
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