Dynamic Strength of Gravelly Soils and Its Relation to the Penetration Resistance

Undrained cyclic triaxial tests have been conducted on specimens of dense diluvial gravelly soils taken from four sites by an in-situ freeze sampling method. The test results and previous test results obtained by other researchers suggest that the dynamic strength of gravelly soils can be evaluated based on both the modified blow count of the penetration tests and on the effective confining pressure. A method for the evaluation by utilizing the large penetration test (LPT) blow counts is proposed in this paper by considering the effect of the effective confining pressure on the dynamic strength

Near- to mid-infrared spectroscopy of the heavily obscured AGN LEDA 1712304 with AKARI/IRC

Context. Although heavily obscured active galactic nuclei (AGNs) have been found by many observational studies, the properties of the surrounding dust are poorly understood. Using AKARI/IRC spectroscopy, we discover a new sample of a heavily obscured AGN in LEDA 1712304 which shows a deep spectral absorption feature due to silicate dust. Aims. We study the infrared (IR) spectral properties of circumnuclear silicate dust in LEDA 1712304. Methods. We perform IR spectral fitting, considering silicate dust properties such as composition, porosity, size and crystallinity. Spectral energy distribution (SED) fitting is also performed to the flux densities in the UV to sub-millimeter range to investigate the global spectral properties. Results. The best-fit model indicates 0.1 $\mu$m-sized porous amorphous olivine (${\rm Mg_{2x}Fe_{2-2x}SiO_4}$; $x=0.4$) with $4\%$ crystalline pyroxene. The optical depth is $\tau_{\rm sil}{\sim}2.3$, while the total IR luminosity and stellar mass are estimated to be $L_{\rm IR}=(5\pm1){\times}10^{10}\,L_{\odot}$ and $M_{\rm star}=(2.7\pm0.8){\times}10^{9}\,M_{\odot}$, respectively. In such low $L_{\rm IR}$ and $M_{\rm star}$ ranges, there are few galaxies which show that large ${\tau}_{\rm sil}$. Conclusions. The silicate dust in the AGN torus of LEDA 1712304 has properties notably similar to those in other AGNs as a whole, but slightly different in the wing shape of the absorption profile. The porosity of the silicate dust suggests dust coagulation or processing in the circumnuclear environments, while the crystallinity suggests that the silicate dust is relatively fresh.Comment: 9 pages, 6 figures, accepted for publication in A&

Liquefaction Case Study of Volcanic Gravel Layer during 1993 Hokkaido-Nansei-Oki Earthquake

During the Hokkaido-Nansei-Oki Earthquake, a high-land area around the foot of the volcano, Mt. Komagatake, in Hokkaido in Northern Japan experienced liquefaction phenomena inflicting damages of differential settlement in some tens of houses in the area. Several kinds of geotechnical site investigations were carried out to study the cause of the damage in a typical liquefaction site. Trenching and geological survey disclosed that Holocene debris avalanche deposit containing a plenty of large rocks actually liquefied. The undrained cyclic triaxial test was carried out on large intact samples taken out by the in-situ freezing sampling. The stress ratio measured in the test was in accordance with the seismic induced stress ratio estimated from the maximum acceleration in the area

Dust properties in the cold and hot gas phases of the ATLAS3D early-type galaxies as revealed by AKARI

The properties of the dust in the cold and hot gas phases of early-type galaxies (ETGs) are key to understand ETG evolution. We thus conducted a systematic study of the dust in a large sample of local ETGs, focusing on relations between the dust and the molecular, atomic, and X-ray gas of the galaxies, as well as their environment. We estimated the dust temperatures and masses of the 260 ETGs from the ATLAS3D survey, using fits to their spectral energy distributions primarily constructed from AKARI measurements. We also used literature measurements of the cold (CO and HI) and X-ray gas phases. Our ETGs show no correlation between their dust and stellar masses, suggesting inefficient dust production by stars and/or dust destruction in X-ray gas. The global dust-to-gas mass ratios of ETGs are generally lower than those of late-type galaxies, likely due to dust-poor HI envelopes in ETGs. They are also higher in Virgo Cluster ETGs than in group and field ETGs, but the same ratios measured in the central parts of the galaxies only are independent of galaxy environment. Slow-rotating ETGs have systematically lower dust masses than fast-rotating ETGs. The dust masses and X-ray luminosities are correlated in fast-rotating ETGs, whose star formation rates are also correlated with the X-ray luminosities. The correlation between dust and X-rays in fast-rotating ETGs appears to be caused by residual star formation, while slow-rotating ETGs are likely well evolved, and thus exhausting their dust. These results appear consistent with the postulated evolution of ETGs, whereby fast-rotating ETGs form by mergers of late-type galaxies and associated bulge growth, while slow-rotating ETGs form by (dry) mergers of fast-rotating ETGs. Central cold dense gas appears to be resilient against ram pressure stripping, suggesting that Virgo Cluster ETGs may not suffer strong related star formation suppression.Comment: 18 pages, 7 figures, accepted for publication in A&

Soil Investigation and FVT Analysis in Hualien LSST SSI Research

An international joint research program, Large-Scale Seismic Test (LSST) Program at Hualien, Taiwan, is ongoing, where a large-scale model structure partly embedded in gravelly layer was constructed, in-depth site soil geotechnical investigation was performed at every one of four construction stages, that is, before excavation, after excavation before structure construction, after structure construction before backfill, and after backfill, forced vibration tests (FVTs) of the model structure before backfill (FVT-1) and after backfill (FVT-2) were performed, and seismic observation of the dynamic SSI (soil-structure interaction) system is underway. This paper describes the change of the shear wave velocity (Vs) accompanied by the construction stage progress, and predictive and correlative FVT analyses, taking above-mentioned Vs change into account

Interpretation from large-scale shake table tests on piles undergoing lateral spreading in liquefied soils

doi: 10.1016/j.soildyn.2005.02.018Results from a benchmark test on full-scale piles are used to investigate the response of piles to lateral spreading. In the experiment, two single piles, a relatively flexible pile that moves together with the surrounding soil and a relatively stiff pile that does not follow the ground movement have been subjected to large post-liquefaction ground displacement simulating piles in laterally spreading soils. The observed response of the piles is first presented and then the results are used to examine the lateral loads on the pile from a non-liquefied soil at the ground surface and to evaluate the stiffness characteristics of the spreading soils. The measured ultimate lateral pressure from the crust soil on the stiff pile was about 4.5 times the Rankine passive pressure. The back-calculated stiffness of the liquefied soil was found to be in the range between 1/30 and 1/80 of the initial stiffness of the soil showing gradual decrease in the course of lateral spreading

The Baculovirus Uses a Captured Host Phosphatase to Induce Enhanced Locomotory Activity in Host Caterpillars

The baculovirus is a classic example of a parasite that alters the behavior or physiology of its host so that progeny transmission is maximized. Baculoviruses do this by inducing enhanced locomotory activity (ELA) that causes the host caterpillars to climb to the upper foliage of plants. We previously reported that this behavior is not induced in silkworms that are infected with a mutant baculovirus lacking its protein tyrosine phosphatase (ptp) gene, a gene likely captured from an ancestral host. Here we show that the product of the ptp gene, PTP, associates with baculovirus ORF1629 as a virion structural protein, but surprisingly phosphatase activity associated with PTP was not required for the induction of ELA. Interestingly, the ptp knockout baculovirus showed significantly reduced infectivity of larval brain tissues. Collectively, we show that the modern baculovirus uses the host-derived phosphatase to establish adequate infection for ELA as a virion-associated structural protein rather than as an enzyme