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A Case Study of Risk Assessment of Ozone Impact on Forest Tree Species in Japan
Watanabe, Makoto,Yamaguchi, Masahiro,Matsumura, Hideyuki,Kohno, Yoshihisa,Koike, Takayoshi,Izuta, Takeshi Korean Society for Atmospheric Environment 2011 Asian Journal of Atmospheric Environment (AJAE) Vol.5 No.4
Ozone ($O_3$) is a main component of photochemical oxidants and a phytotoxic air pollutant. Although the current levels of tropospheric $O_3$ in East Asia could adversely affect productivity of forest tree species, risk assessments of $O_3$ impact were limited. In this paper, we summarize the methodology of risk assessment of $O_3$ on forest tree species based on our two previous studies, risk assessments of $O_3$ impact on the growth of Fagus crenata by Watanabe et al. (2012) and on the annual carbon absorption of three representative conifers, Cryptomeria japonica, Pinus densiflora and Larix kaempferi by Watanabe et al. (2010). $O_3$ sensitivity of each tree species obtained from an experimental study, $O_3$ exposure and atmospheric N deposition based on field monitoring and vegetation survey were integrated by geographic information system method. Based on the results, we conclude that the area with high risk of $O_3$ impact does not necessarily correspond to the area with high $O_3$ exposure. The varieties of tree habitat, tree sensitivity to $O_3$ and annual carbon absorption among the tree species, and N deposition-induced change in the $O_3$ sensitivity of F. crenata are raised as the factors of discordance between areas with high risk and those with high $O_3$ exposure. In the last part of this paper, we discuss the present uncertainty and perspectives of risk assessment for the future studies on the impact of $O_3$ on forest tree species in East Asia.
A Case Study of Risk Assessment of Ozone Impact on Forest Tree Species in Japan
Makoto Watanabe,Masahiro Yamaguchi,Hideyuki Matsumura,Yoshihisa Kohno,Takayoshi Koike,Takeshi Izuta 한국대기환경학회 2011 Asian Journal of Atmospheric Environment (AJAE) Vol.5 No.4
Ozone (O_3) is a main component of photochemical oxidants and a phytotoxic air pollutant. Although the current levels of tropospheric O_3 in East Asia could adversely affect productivity of forest tree species,risk assessments of O_3 impact were limited. In this paper, we summarize the methodology of risk assessment of O_3 on forest tree species based on our two previous studies, risk assessments of O_3 impact on the growth of Fagus crenata by Watanabe et al. (2012) and on the annual carbon absorption of three representative conifers, Cryptomeria japonica, Pinus densiflora and Larix kaempferi by Watanabe et al. (2010). O_3 sensitivity of each tree species obtained from an experimental study, O_3 exposure and atmospheric N deposition based on field monitoring and vegetation survey were integrated by geographic information system method. Based on the results, we conclude that the area with high risk of O_3 impact does not necessarily correspond to the area with high O_3 exposure. The varieties of tree habitat, tree sensitivity to O_3 and annual carbon absorption among the tree species, and N deposition-induced change in the O_3 sensitivity of F. crenata are raised as the factors of discordance between areas with high risk and those with high O_3 exposure. In the last part of this paper, we discuss the present uncertainty and perspectives of risk assessment for the future studies on the impact of O_3 on forest tree species in East Asia.
An estimation of static aerodynamic forces of box girders using computational fluid dynamics
Watanabe, Shigeru,Inoue, Hiroo,Fumoto, Koichiro Techno-Press 2004 Wind and Structures, An International Journal (WAS Vol.7 No.1
This study has focused on aerodynamics for a wind-resistance design about the single and tandem box girder sections to realize a super-long span bridge in the near future. Three-dimensional static analysis of flows around the fundamental single and tandem box girder sections with fairing is carried out by means of the IBTD/FS finite element technique with LES turbulence model. As the results of the analysis, computations have verified aerodynamic characteristics of both sections by the histories of aerodynamic forces, the separation and reattachment flow patterns and the surface pressure distributions. The relationship between the section shapes and the aerodynamic characteristics is also investigated in both sections. And the mechanism about the generation of fluctuating aerodynamic forces is discussed.
Dark aerobic methane emission associated to leaf factors of two Acacia and five Eucalyptus species
Watanabe, M.,Watanabe, Y.,Kim, Y.S.,Koike, T. Pergamon Press ; Elsevier [distribution] 2012 Atmospheric environment Vol.54 No.-
We sought the biological factors determining variations in the methane emission rates from leaves of different plant species under aerobic conditions. Accordingly, we studied relations between the methane emission rate and leaf traits of two Acacia and five Eucalyptus species. We grew seedlings of each species in a glasshouse and measured the methane emission rate of the detached leaves under dark conditions at 30 <SUP>o</SUP>C. At the same time we measured the leaf mass per area (LMA), water content, and concentrations of carbon and nitrogen. There was no correlation between the leaf nitrogen concentration and the methane emission rate. This is consistent with previous findings that enzymatic processes do not influence methane emission. We found a significant negative correlation between LMA and the methane emission rate. Our results suggest that leaf structure is primarily responsible for differences in the rates of aerobic methane emission from leaves of different species.
Rotating Choke and Choked Surge in an Axial Pump Impeller
Watanabe, Toshifumi,Sato, Hideyoshi,Henmi, Yasuhiko,Horiguchi, Hironori,Kawata, Yutaka,Tsujimoto, Yoshinobu Korean Society for Fluid machinery 2009 International journal of fluid machinery and syste Vol.2 No.3
Unlike usual turbopump inducers, the axial flow pump tested operates very stably at design flow rate without rotating cavitation nor cavitation surge. Flow visualization suggests that this is because the tip cavity smoothly extends into the flow passage without the interaction with the leading edge of the next blade. However, at low flow rate and low cavitation number, choked surge and rotating choke were observed. Their correlation with the performance curve under cavitation is discussed and their instantaneous flow fields are shown.
Internal Flow of a Two-Bladed Helical Inducer at an Extremely Low Flow Rate
Watanabe, Satoshi,Inoue, Naoki,Ishizaka, Koichi,Furukawa, Akinori,Kim, Jun-Ho Korean Society for Fluid machinery 2010 International journal of fluid machinery and syste Vol.3 No.2
The attachment of inducer upstream of main impeller is an effective method to improve the suction performance of turbopump. However, various types of cavitation instabilities are known to occur even at the designed flow rate as well as in the partial flow rate region. The cavitation surge occurring at partial flow rates is known to be strongly associated with the inlet back flow. In the present study, in order to understand the detailed structure of internal flow of inducer, we firstly carried out the experimental and numerical studies of non-cavitating flow, focusing on the flow field near the inlet throat section and inside the blade passage of a two bladed inducer at a partial flow rate. The steady flow simulation with cavitation model was also made to investigate the difference of flow field between in the cavitating and no-cavitating conditions.
Anti-dementia Effects of Gouteng-san and Si-Wu-Tang
Watanabe, Hiroshi The Korean Society of Toxicology Korea Environment 2001 Toxicological Research Vol.17 No.-
Recently, a traditional medicine called Gouteng-san, which consists of eleven herbs, was reported to be effective in treating vascular dementia with a double-blind, placebo-controlled study. Gout-eng-san is also used for patients with vascular dementia in combination with Si-Wu-Tang. The effect of Gouteng-san and Si-Wu-Tang on deficit of learning behavior was investigated using step-down passive avoidance task in mice. Hot-water extract of Gouteng-san (1.5 and 6 g/kg, p.o.) significantly prolonged the step-down latency shortened by scopolamine. The extract of Uncaria hook (150 mg/kg, p.o.), one of the component herb of Gouteng-san, significantly prevented the decrease in the latency after scopolamine. Hot-water extract of Si-Wu-Tang (1.5 and 6 g/kg of dried herbs, p.o.) prevented dose-dependently scopola-mine-induced disruption qf learning behavior. Si-Wu-Tang also prevented the ischemia-induced deficit of learning behavior. Both hot water extract of peony and angelica (1.5 g/kg, p.o.), which are component herbs qf Si-Wu-Tang, prevented the scopolamine-induced learning behavior deficit. Scopolamine (10 uM) suppressed long-term potentiation (LTP) of population spike in the CA1 region of the rat hippocampal slices. Peoniflorin (0.1~ 1uM) extracted from paeony root significantly ameliorated scopolamine-induced inhibition of LTR These results suggest that improvement of deficit of learning behavior by Gouteng-san and Si-Wu-Tang is mediated by direct and/or indirect activation of the cholinergic system in the brain.
Present Status of Research on Design and Processing of Functionally Graded Materials
Watanabe, Ryuzo,Nishida, Toshihiko,Hirai, Toshio 대한금속재료학회 2003 METALS AND MATERIALS International Vol.9 No.6
Recent activities in the research of functionally graded materials (FGMs) are reviewed with an emphasis on the fabrication techniques for graded microstructure and functions. The research activities have focused on the processing of graded structures that satisfy the designed functions. Several examples of practical applications of FGMs are described in the present paper to demonstrate the fabrication approaches typical to this kind of material. The remainder of the paper is devoted to summarizing a recently finished national project supported by the Ministry of Education of Japan. Research and developments with respect to FGMs in various fields including physics, chemistry, medical science, and biology are briefly reviewed.