Radio spectra of the low-luminosity active galactic nucleus NGC 266 at centimetre-to-submillimetre wavelengths     

A. Doi  S. Kameno  M. Inoue 《Monthly notices of the Royal Astronomical Society》2005,360(1):119-124

We report multi-frequency and multi-epoch radio continuum observations with multi-spatial resolution for the low-luminosity active galactic nucleus (LLAGN) NGC 266. In the centimetre regime, we find diffuse components with Very Large Array (VLA) observations, and a variable compact core with a rising spectrum with Very Long Baseline Array (VLBA) observations. Although the spectral index of the rising spectrum is consistent with the prediction of the simple advection-dominated accretion flow (ADAF) model, the observed radio power is slightly high compared with that of the model prediction. A spectral break at centimetre-to-millimetre wavelengths is inferred from the upper limits of flux densities from Nobeyama Millimetre Array (NMA) and James Clerk Maxwell Telescope (JCMT) data at millimetre and submillimetre wavelengths, respectively. More complicated considerations are required for the theoretical model to interpret such observed radio properties.  相似文献   

In situ strength measurements on natural upper-mantle minerals   总被引：1，自引：0，他引：1  

Junji Yamamoto  Jun-ichi Ando  Hiroyuki Kagi  Toru Inoue  Akihiro Yamada  Daisuke Yamazaki  Tetsuo Irifune 《Physics and Chemistry of Minerals》2008,35(5):249-257

Using in situ strength measurements at pressures up to 10 GPa and at room temperature, 400, 600, and 700°C, we examined rheological properties of olivine, orthopyroxene, and chromian-spinel contained in a mantle-derived xenolith. Mineral strengths were estimated using widths of X-ray diffraction peaks as a function of pressure, temperature, and time. Differential stresses of all minerals increase with increasing pressure, but they decrease with increasing temperature because of elastic strain on compression and stress relaxation during heating. During compression at room temperature, all minerals deform plastically at differential stress of 4–6 GPa. During subsequent heating, thermally induced yielding is observed in olivine at 600°C. Neither orthopyroxene nor spinel shows complete stress relaxation, but both retain some stress even at 700°C. The strength of the minerals decreases in the order of chromian-spinel ≈ orthopyroxene > olivine for these conditions. This order of strength is consistent with the residual pressure of fluid inclusions in mantle xenoliths.  相似文献   

Methodology for preliminary assessment of Natech risk in urban areas   总被引：1，自引：0，他引：1  

Ana Maria Cruz  Norio Okada 《Natural Hazards》2008,46(2):199-220

Concern for natural hazard-triggered technological disasters (Natech disasters) in densely populated and industrialized areas is growing. Residents living in urban areas subject to high natural hazard risk are often unaware of the potential for secondary disasters such as hazardous materials releases from neighboring industrial facilities, chemical storage warehouses or other establishments housing hazardous materials. Lessons from previous disasters, such as the Natech disaster during the Kocaeli earthquake in Turkey in 1999 call for the need to manage low frequency/high consequence events, particularly in today’s densely populated areas. However, there is little guidance available on how local governments and communities can assess Natech risk. To add to the problem, local governments often do not have the human or economic resources or expertise to carry out detailed risk assessments. In this article, we propose a methodology for preliminary assessment of Natech risk in urban areas. The proposed methodology is intended for use by local government officials in consultation with the public. The methodology considers possible interactions between the various systems in the urban environment: the physical infrastructure (e.g., industrial plants, lifeline systems, critical facilities), the community (e.g., population exposed), the natural environment (e.g., delicate ecosystems, river basins), and the risk and emergency management systems (e.g., structural and nonstructural measures). Factors related to vulnerability and hazard are analyzed and qualitative measures are recommended. Data from hazardous materials releases during the Kocaeli, Turkey earthquake of August 17, 1999 are used as a case study to demonstrate the applicability of the methodology. Limitations of the proposed methodology are discussed as well as future research needs.

Norio OkadaEmail:

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1975 Lecture by the winner of the Okada Prize     

Norio Ogura 《Journal of Oceanography》1975,31(5):219-226

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Convergence,divergence and vertical velocity at a tidal front in Hiuchi-Nada,Japan   总被引：2，自引：0，他引：2  

Tetsuo Yanagi  Koji Ishikawa  Koh-ichi Inoue  Satoshi Susami 《Journal of Oceanography》1995,51(2):225-238

The detailed flow structure around a tical front in Hiuchi-Nada, Japan was observed with the use of ADCP (Acoustic Doppler Current Profiler). The surface convergence region is observed at the transition zone between vertically well mixed area and the stratified area. The surface divergence regions exist next to the surface convergence region. The strong downward current is estimated in the middle layer just below the surface convergence region. The maximum surface convergence and the maximum downward velocity in the middle layer are 1.0×10^–4 s^–1 and 0.12 cm s^–1, respectively.  相似文献   

I-1 Wave energy absorption characteristics of circular air chamber for use of light beacon     

Reisaku Inoue  Masami Iwai 《Ocean Engineering》1985,12(6):554-555

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Validity of sea surface temperature observed with the TRITON buoy under diurnal heating conditions     

Yoshimi Kawai  Hiroshi Kawamura  Sumio Tanba  Kentaro Ando  Kunio Yoneyama  Norio Nagahama 《Journal of Oceanography》2006,62(6):825-838

In order to investigate the validity of buoy-observed sea surface temperature (SST), we installed special instruments to measure near-surface ocean temperature on the TRITON buoy moored at 2.07°N, 138.06°E from 2 to 13 March 2004, in addition to a standard buoy sensor for the regular SST measurement at 1.5-m depth. Large diurnal SST variations were observed during this period, and the variations of the temperatures at about 0.3-m depth could be approximately simulated by a one-dimensional numerical model. However, there was a notable discrepancy between the buoy-observed 1.5-m-depth SST (SST_1.5m) and the corresponding model-simulated temperature only during the daytime when the diurnal rise was large. The evaluation of the heat balance in the sea surface layer showed that the diurnal rise of the SST_1.5m in these cases could not be accounted for by solar heating alone. We examined the depth of the SST_1.5m sensor and the near-surface temperature observed from a ship near the buoy, and came to the conclusion that the solar heating of the buoy hull and/or a disturbance in the temperature field around the buoy hull would contribute to the excessive diurnal rise of the SST_1.5m observed with the TRITON buoy. However, the temperature around the hull was not sufficiently homogenized, as suggested in a previous paper. For the diurnal rise of the SST_1.5m exceeding 0.5 K, the daytime buoy data became doubtful, through dynamics that remain to be clarified. A simple formula is proposed to correct the unexpected diurnal amplitude of the buoy SST_1.5m.  相似文献   

Synchrotron IR study of hydrous ringwoodite (γ-Mg2SiO4) up to 30 GPa     

E. M. Chamorro Pérez  I. Daniel  J.-C. Chervin  P. Dumas  J. D. Bass  T. Inoue 《Physics and Chemistry of Minerals》2006,33(7):502-510

High-pressure synchrotron infrared (IR) absorption spectra were collected between 650 and 4,000 cm⁻¹ at ambient temperature for hydrous Mg-ringwoodite (γ-Mg₂SiO₄) up to 30 GPa. The main feature in the OH⁻ stretching region is an extremely broad band centred at 3,150 cm⁻¹. The hydrogen bond is strong for most protons and the most probable site for protonation is the tetrahedral edge. With increasing pressure, this band shifts downward while decreasing its integrated intensity until disappearance at a pressure of 25 GPa. Only one band at 2,450 cm⁻¹ and an absorption plateau persist with a maximum wavenumber of 3,800 cm⁻¹. This behaviour is reversible upon pressure release. We interpret this as a second-order phase transition occurring in hydrated Mg-ringwoodite at high pressure (beyond ∼ 25 GPa). This result is compatible with the observation by Kleppe et al. (Phys Chem Miner 29:473–476, 2002a) who suggested the presence of Si–O–Si linkages and/or partial increase in the coordination of Si. Beyond the phase transition, the protons are delocalized and their environment on the ringwoodite structure is probably quite different from that at low pressure. Data obtained in situ at high pressures and temperatures are needed to better understand the effect of protonation on the structure and to better constrain this phase transition.  相似文献   

Damaging properties of ground motions and prediction of maximum response of structures based on momentary energy response     

Norio Hori  Norio Inoue 《地震工程与结构动力学》2002,31(9):1657-1679

Dynamic damaging potential of ground motions must be evaluated by the response behaviour of structures, and it is necessary to indicate what properties of ground motions are most appropriate for evaluation. For that purpose, the behaviour of energy input process and hysteretic energy dissipation are investigated in this study. It is found that the momentary input energy that is an index for the intensity of input energy is related to the characteristics of earthquakes such as cyclic or impulsive, and to the response displacement of structures immediately. On the basis of these results, a procedure is proposed to predict inelastic response displacement of structures by corresponding earthquake input energy to structural dissipated damping and hysteretic energy. In this procedure the earthquake response of structures is recognized as an input and dissipation process of energy, and therefore structural properties and damaging properties of ground motions can be taken into account more generally. Lastly, the studies of the pseudodynamic loading test of reinforced concrete structure specimens subjected to ground motions with different time duration are shown. The purpose of this test is to estimate the damaging properties of ground motions and the accuracy of the proposed prediction procedure. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

Process of Housing Damage Assessment: The 1995 Hanshin-Awaji Earthquake Disaster Case     

Horie  Kei  Maki  Norio  Kohiyama  Masayuki  Lu  Hengjian  Tanaka  Satoshi  Hashitera  Shin  Shigekawa  Kishie  Hayashi  Haruo 《Natural Hazards》2003,29(3):341-370

Rebuilding of victims' livelihoods was a crucial issue in the restoration process in the1995 Hanshin-Awaji Earthquake Disaster. Housing damage assessment influencedmost of the rebuilding of the livelihood in the long term, because the Victim Certificatesissued by the local governments based on the results of the Housing damage assessmentwas required to receive most of the individual assistance measures. In the process ofHousing damage assessment, many complex problems arose, leading to extensivework on the part of the disaster responders. Consequently, a considerable number ofvictims were dissatisfied with the assessment and applied for a resurvey. Due to a floodof requests for resurvey, disaster responders had to work on damage assessment, leavingrelief activities aside.In order to facilitate Housing damage assessment, this paper discusses thefollowing five points: (1) the processes and the problems of assessments performedin the Hanshin-Awaji Earthquake Disaster, (2) the changes in the nature of informationneeded by the victims, (3) the improvements over the present damage assessment, (4)the housing situation in Japan, and (5) the international situation on damage assessment.It is obvious from the results that a poor damage assessment system and the size ofthe disaster produced a very large work load. Differences in appreciation among theinvestigators also contributed to unfair assessments and led to the victims beingincreasingly dissatisfied by the survey results. Finally, a design concept for acomprehensive damage assessment system, which has been derived from theabove five points, is proposed for post-disaster management.  相似文献