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Journal Articles

Spectral reflectance and associated photograph of boreal forest understory formation in interior Alaska

Kobayashi, Hideki*; Suzuki, Rikie*; Yang, W.*; Ikawa, Hiroki*; Inoue, Tomoharu*; Nagano, Hirohiko; Kim, Y.*

Polar Data Journal (Internet), 2, p.14 - 29, 2018/11

The Arctic and boreal regions have been experiencing a rapid warming in the 21st century. It is important to understand the dynamics of boreal forest at the continental scale under the climate and environmental changes. While the role of understory vegetation in boreal forest ecosystems on carbon and nutrient cycling cannot be ignored, they are still one of least understood components in boreal ecosystems. Spectroscopic measurements of vegetation are useful to identify species and their biochemical characteristics. In this data paper, we present spectral reflectances of 44 typical understory formations and five 30-m long transects. The spectral reflectance covers the spectral region of visible, near infrared and shortwave infrared (350-2500 nm). For the transect measurements, we decided the length of transect at 30 m, similar to the scale of one pixel of a Landsat type satellite imagery. The photographs at all positions, where spectral reflectances were obtained, are included to understand the structure and status of each sample. The data set contains six dwarf shrubs (blueberry (${it Vaccinium uliginosum}$), cowberry (${it Vaccinium vitisidea}$), feltleaf willow (${it Salix alaxensis}$), young birch (${it Betula neoalaskana}$), young aspen (${it Pupulus tremuloides}$), and young black spruce (${it Picea mariana}$)), two herbaceous (cottongrass (${it Eriophorum vaginatum}$) and marsh Labrador tea (${it Ledum decumbens}$)), three mosses (Sphagnum moss, splendid feather moss (${it Hylocomium splendens}$), and polytrichum moss (${it Polytrichum commune}$)), and reindeer lichen (${it Cladonia rangiferina}$). Spectral reflectances from several non-vegetative such as snow, litter, and soil are also included. This spectral and photographic data set can be used for understanding the spectral characteristics of understory formations, designing newly planned spectral observations, and developing and validating the remote sensing methodology of large scale understory monitoring.

Journal Articles

In situ observations reveal how spectral reflectance responds to growing season phenology of an open evergreen forest in Alaska

Kobayashi, Hideki*; Nagai, Shin*; Kim, Y.*; Yan, W.*; Ikeda, Kyoko*; Ikawa, Hiroki*; Nagano, Hirohiko; Suzuki, Rikie*

Remote Sensing, 10(7), p.1071_1 - 1071_19, 2018/07

 Times Cited Count:4 Percentile:55.99(Remote Sensing)

Plant phenology timings, such as spring green-up and autumn senescence, are essential state information characterizing biological responses and terrestrial carbon cycles. Current efforts for the in situ reflectance measurements are not enough to obtain the exact interpretation of how seasonal spectral signature responds to phenological stages in boreal evergreen needleleaf forests. This study shows the first in situ continuous measurements of canopy scale (overstory + understory) and understory spectral reflectance and vegetation index in an open boreal forest in interior Alaska. Two visible and near infrared spectroradiometer systems were installed at the top of the observation tower and the forest understory, and spectral reflectance measurements were performed in 10 min intervals from early spring to late autumn. We found that canopy scale normalized difference vegetation index (NDVI) varied with the solar zenith angle. On the other hand, NDVI of understory plants was less sensitive to the solar zenith angle. Due to the influence of the solar geometry, the annual maximum canopy NDVI observed in the morning satellite overpass time (10-11 am) shifted to the spring direction compared with the standardized NDVI by the fixed solar zenith angle range (60-70 degree). We also found that the in situ NDVI time-series had a month-long high NDVI plateau in autumn, which was completely out of photosynthetically active periods when compared with eddy covariance net ecosystem exchange measurements. The result suggests that the onset of an autumn high NDVI plateau is likely to be the end of the growing season. In this way, our spectral measurements can serve as baseline information for the development and validation of satellite-based phenology algorithms in the northern high latitudes.

Journal Articles

Neutron diffraction of ice and water in hydrogels

Sekine, Yurina; Kobayashi, Riki*; Chi, S.*; Fernandez-Baca, J. A.*; Suzuya, Kentaro; Fujisaki, Fumika*; Ikeda, Kazutaka*; Otomo, Toshiya*; Fukazawa, Tomoko*; Yamauchi, Hiroki; et al.

JPS Conference Proceedings (Internet), 8, p.033009_1 - 033009_6, 2015/09

Neutron diffraction profiles of low-D$$_{2}$$O-content poly-N,N,-dimethylacrylamide (PDMAA) hydrogels were measured from 100 to 300 K to investigate the structure and properties of water in hydrogels. A broad diffraction observed at temperatures lower than 220 K indicates the existence of amorphous ice in the hydrogels at low temperatures. During the heating process, diffraction peaks from ice crystals appear in the profiles. These peaks indicate that cubic ice and hexagonal ice exist at T $$geq$$ 220 K. We refined the structure parameters of these ices in the hydrogel, which indicate the existence of low-density ice in the hydrogel.

Journal Articles

Performance evaluation of the European Committee Standardization Method EN1785 for the detection of irradiated processed food

Tsutsumi, Tomoaki*; Adachi, Rika*; Takatsuki, Satoshi*; Nei, Daisuke*; Kameya, Hiromi*; Todoriki, Setsuko*; Kikuchi, Masahiro; Kobayashi, Yasuhiko; Matsuda, Rieko*; Teshima, Reiko*

Shokuhin Shosha, 49(1), p.9 - 15, 2014/12

no abstracts in English

Journal Articles

Influence of electron doping on magnetic order in CeRu$$_2$$Al$$_{10}$$

Kobayashi, Riki*; Kaneko, Koji; Saito, Kotaro*; Mignot, J.-M.*; Andr$'e$, G.*; Robert, J.*; Wakimoto, Shuichi; Matsuda, Masaaki*; Chi, S.*; Haga, Yoshinori; et al.

Journal of the Physical Society of Japan, 83(10), p.104707_1 - 104707_5, 2014/10

 Times Cited Count:13 Percentile:28.67(Physics, Multidisciplinary)

Journal Articles

Spin-chirality-driven ferroelectricity on a perfect triangular lattice antiferromagnet

Mitamura, Hiroyuki*; Watanuki, Ryuta*; Kaneko, Koji; Onozaki, Norimichi*; Amo, Yuta*; Kittaka, Shunichiro*; Kobayashi, Riki*; Shimura, Yasuyuki*; Yamamoto, Isao*; Suzuki, Kazuya*; et al.

Physical Review Letters, 113(14), p.147202_1 - 147202_5, 2014/10

 Times Cited Count:12 Percentile:30.42(Physics, Multidisciplinary)

Journal Articles

Neutron diffraction of ice in hydrogels

Sekine, Yurina; Fukazawa, Tomoko*; Aizawa, Mamoru*; Kobayashi, Riki*; Chi, S.*; Fernandez-Baca, J. A.*; Yamauchi, Hiroki; Fukazawa, Hiroshi

Journal of Physical Chemistry B, 118(47), p.13453 - 13457, 2014/08

 Times Cited Count:1 Percentile:97.6(Chemistry, Physical)

Neutron diffraction patterns for deuterated poly-$$N$$,$$N$$,-dimethylacrylamide (PDMAA) hydrogels were measured from 10 to 300 K to investigate the structure and properties of water in the gels. Diffraction peaks observed below 250 K indicate the existence of ice in the hydrogels. Some diffraction peaks from the ice are at lower diffraction angles than those in ordinary hexagonal ice (Ih). These shifts in peaks indicate that the lattice constants of the $$a$$ and $$c$$ axes in the ice are about 0.29% and 0.3% higher than those in ice Ih, respectively. The results show that bulk low-density ice can exist in PDMAA hydrogels. The distortions in the lattice structure of ice imply significant interactions between water molecules and the surrounding polymer chains, which play an important role in the chemical and mechanical properties of the hydrogel.

Journal Articles

Anharmonic Pr guest modes in Pr(Os$$_{1-x}$$Ru$$_x$$)$$_4$$Sb$$_{12}$$ investigated by inelastic X-ray scattering

Tsutsui, Satoshi; Kaneko, Koji; Miyazaki, Ryoichi*; Higashinaka, Ryuji*; Aoki, Yuji*; Kobayashi, Riki*; Wakimoto, Shuichi; Baron, A. Q. R.*; Sugawara, Hitoshi*; Sato, Hideyuki*

JPS Conference Proceedings (Internet), 3, p.011060_1 - 011060_5, 2014/06

Journal Articles

Comparison of $$J$$c characteristics in PIT wires based on BaFe$$_{2}$$As$$_{2}$$ with different substitutions

Tamegai, Tsuyoshi*; Pyon, S.*; Ding, Q. P.*; Inoue, Hiroshi*; Kobayashi, Hiroki*; Tsuchiya, Yuji*; Sun, Y.*; Kajitani, Hideki; Koizumi, Norikiyo

Journal of Physics; Conference Series, 507(2), p.022041_1 - 022041_4, 2014/05

 Times Cited Count:3 Percentile:16.77

The author studied the effect of chemical compound for superconducting performance ($$J$$c) of iron-based superconductors. As a result, it was revealed that BaFe$$_{2}$$As$$_{2}$$ showed high Jc. And more, BaFe$$_{2}$$As$$_{2}$$ showed higer $$J$$c such as 32,000A/cm$$^{2}$$ (4.2K) by being applied of 120 MPa of hot isostatic pressure (HIP). Thus, higher $$J$$c performance could be achieved.

Journal Articles

Powder neutron diffraction study of HoCoGa$$_{5}$$

Kobayashi, Riki; Kaneko, Koji; Wakimoto, Shuichi; Chi, S.*; Sanada, Naoyuki*; Watanuki, Ryuta*; Suzuki, Kazuya*

Journal of the Korean Physical Society, 63(3), p.337 - 340, 2013/08

 Times Cited Count:3 Percentile:67.89(Physics, Multidisciplinary)

Journal Articles

Uniaxial-pressure control of magnetic phase transitions in a frustrated magnet CuFe$$_{1-x}$$Ga$$_{x}$$O$$_{2}$$ (x =0, 0.018)

Nakajima, Taro*; Mitsuda, Setsuo*; Takahashi, Keiichiro*; Yoshitomi, Keisuke*; Masuda, Kazuya*; Kaneko, Chikafumi*; Homma, Yuki*; Kobayashi, Satoru*; Kitazawa, Hideaki*; Kosaka, Masashi*; et al.

Journal of the Physical Society of Japan, 81(9), p.094710_1 - 094710_8, 2012/09

Journal Articles

Uniaxial-pressure control of magnetic phase transitions in a frustrated magnet CuFe$$_{1-x}$$Ga$$_{x}$$O$$_{2}$$ ($$x$$ = 0, 0.018)

Nakajima, Taro*; Mitsuda, Setsuo*; Takahashi, Keiichiro*; Yoshitomi, Keisuke*; Masuda, Kazuya*; Kaneko, Chikafumi*; Homma, Yuki*; Kobayashi, Satoru*; Kitazawa, Hideaki*; Kosaka, Masashi*; et al.

Journal of the Physical Society of Japan, 81(9), p.094710_1 - 094710_8, 2012/09

 Times Cited Count:10 Percentile:39.75(Physics, Multidisciplinary)

Journal Articles

Analysis of relaxation times of radicals in irradiated black pepper using pulse-ESR and CW-ESR

Kameya, Hiromi*; Kikuchi, Masahiro; Todoriki, Setsuko*; Furuta, Masakazu*; Kobayashi, Yasuhiko; Hara, Hideyuki*; Shimoyama, Yuhei; Ukai, Mitsuko*

Shokuhin Shosha, 47(1), p.6 - 10, 2012/09

no abstracts in English

Journal Articles

Relaxation behaviors of free radicals from $$gamma$$-irradiated black pepper using pulsed EPR spectroscopy

Kameya, Hiromi*; Kikuchi, Masahiro; Hara, Hideyuki*; Furuta, Masakazu*; Todoriki, Setsuko*; Kobayashi, Yasuhiko; Ukai, Mitsuko*; Shimoyama, Yuhei

Applied Magnetic Resonance, 42(2), p.153 - 159, 2012/03

 Times Cited Count:3 Percentile:75.55(Physics, Atomic, Molecular & Chemical)

no abstracts in English

Journal Articles

Magnetic structure determination of Ce$$T_{2}$$Al$$_{10}$$ ($$T$$ = Ru and Os); Single crystal neutron diffraction studies

Kato, Harukazu*; Kobayashi, Riki; Takesaka, Tomoaki*; Nishioka, Takashi*; Matsumura, Masahiro*; Kaneko, Koji; Metoki, Naoto

Journal of the Physical Society of Japan, 80(7), p.073701_1 - 073701_4, 2011/07

 Times Cited Count:53 Percentile:9.62(Physics, Multidisciplinary)

Journal Articles

Detection of irradiated garlic blub using ESR spectroscopy, PSL and TL methods

Kameya, Hiromi*; Saito, Kimie*; Kikuchi, Masahiro; Kobayashi, Yasuhiko; Ukai, Mitsuko*; Todoriki, Setsuko*

Nippon Shokuhin Kagaku Kogakkai-Shi, 57(11), p.472 - 478, 2010/11

The detection methods of $$gamma$$ ray irradiated garlic blub were studied using electron spin resonance (ESR) spectroscopy, photo stimulated luminescence (PSL) and thermo luminescence (TL). The radiation source was $$^{60}$$Co, the dose level was 50 to 180 Gy. The ESR spectra were consisted of one singlet signal at $$g$$ = 2.00. Upon irradiation, the intensity of the singlet signal was increased. The intensity of PSL signals from stem of irradiated garlic blub was increased as compared with that from non irradiated ones. In TL measurement the glow 1 curves of irradiated samples exhibited a maximum at temperature range of 180 to 220$$^{circ}$$C, whereas those of the non irradiated samples were observed at about 300$$^{circ}$$C. TL glow ratios calculated over the temperature range of 150 to 250$$^{circ}$$C were significantly smaller in non irradiated samples than in irradiated samples after one year storage. Thus irradiated garlic blub was identified by the shape of TL glow 1 curves and TL glow ratios. We concluded ESR, PSL and TL are suitable for detection method of irradiated garlic blub.

Journal Articles

Sprouting and rooting inhibition of garlic with Co-60 $$gamma$$-rays

Kobayashi, Yasuhiko; Kikuchi, Masahiro; Todoriki, Setsuko*; Saito, Kimie*; Katsura, Yoko*; Kameya, Hiromi*; Ichikawa, Mariko*; Iizuka, Tomoko*; Chiba, Etsuko*; Ukai, Mitsuko*

Shokuhin Shosha, 45(1-2), p.26 - 33, 2010/09

Effect of $$gamma$$-irradiation on sprouting and rooting of garlic was investigated. Sprouting and rooting of garlic were inhibited by irradiation of bulbs at 2 months after harvest with doses more than 30 Gy. Four weeks-later irradiation requires higher doses to complete sprouting/rooting inhibition.

Journal Articles

Basic vacuum test of 500-kV photocathode DC gun components at KEK

Yamamoto, Masahiro*; Uchiyama, Takashi*; Miyajima, Tsukasa*; Honda, Yosuke*; Sato, Kotaro*; Matsuba, Shunya*; Saito, Yoshio*; Kobayashi, Masanori*; Kurisu, Hiriki*; Hajima, Ryoichi; et al.

Proceedings of 7th Annual Meeting of Particle Accelerator Society of Japan (DVD-ROM), p.717 - 720, 2010/08

A 500-kV photocathode DC electron gun which can supply the beam of a low emittance and a high average current has been developed in collaboration with KEK, JAEA, Hiroshima Univ., Nagoya Univ. and Yamaguchi Univ. The vacuum of the gun chamber has to be lower Extreme High Vacuum for maintain cathode-life time. A titanium chamber and new material of ceramic were employed to reduce outgassing rate. The result of outgassing rate of the gun chamber is described in this report.

Journal Articles

Recent progress in the energy recovery linac project in Japan

Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.

Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05

Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.

Journal Articles

Detection method for irradiated garlic using ESR

Ukai, Mitsuko*; Kameya, Hiromi*; Nakamura, Hideo*; Todoriki, Setsuko*; Kikuchi, Masahiro; Sakashita, Tetsuya; Funayama, Tomoo; Kobayashi, Yasuhiko

JAEA-Review 2009-041, JAEA Takasaki Annual Report 2008, P. 85, 2009/12

By Electron Spin Resonance (ESR) spectroscopy, we revealed free radicals in irradiated garlic. The representative ESR spectrum of garlic is composed of a singlet at the ${it g}$-value of 2.0. The signal is due to organic free radicals. Upon $$gamma$$-irradiation, new signals appeared. To analyze the irradiation effects, we proposed an ESR detection method of irradiated garlic.

52 (Records 1-20 displayed on this page)