83 research outputs found
Effect of shatterproof polymer film application on the fracture types and strength of glass subject to bending load
Shatterproof polymer films are widely for windows used because they can be
easily installed on existing glass windows to improve safety. Applying them to
glass plates has been reported to not only prevent fragments from scattering
but also increase load-bearing capacity and penetration resistance. However,
the clarification of their mechanism and quantitative evaluation are still
insufficient because the effect of film application on the strength and failure
mode of glass under quasi-static loading has not been investigated. In this
study, three-point bending tests and fracture surface observations were
conducted on a float glass with a shatterproof polymer film. The stress field
formed inside the glass was visualised during the tests using the photoelastic
method. By varying the support span of the specimen, the deformation mode was
varied to generate three types of failures: bending, shear caused by Hertzian
contact stress, and mixed-mode failures. Under the conditions in the present
study, the breaking loads of the specimens with and without film were almost
the same; however, the fracture surface observation indicated that the area
subjected to shear failure caused by Hertzian contact stress was larger with
film application. Finally, the effect of the film thickness on the breaking
load due to bending deformation was theoretically predicted.Comment: In pres
Cool core disturbed: Observational evidence for coexistence of sub-sonic sloshing gas and stripped shock-heated gas around the core of RX J1347.5-1145
RXJ1347.5-1145 (z = 0.451) is one of the most luminous X-ray galaxy clusters,
which hosts a prominent cool core and exhibits a signature of a major merger.
We present the first direct observational evidence for sub-sonic nature of
sloshing motion of the cool core. We find that a residual X-ray image from the
Chandra X-ray Observatory after removing the global emission shows a clear
dipolar pattern characteristic of gas sloshing, whereas we find no significant
residual in the Sunyaev-Zel'dovich effect (SZE) image from the Atacama Large
Millimeter/submillimeter Array (ALMA). We estimate the equation of state of
perturbations in the gas from the X-ray and SZE residual images. The inferred
velocity is 420 +310 -420 km s-1, which is much lower than the adiabatic sound
speed of the intracluster medium in the core. We thus conclude that the
perturbation is nearly isobaric, and gas sloshing motion is consistent with
being in pressure equilibrium. Next, we report evidence for gas stripping of an
infalling subcluster, which likely shock-heats gas to high temperature well in
excess of 20 keV. Using mass distribution inferred from strong lensing images
of the Hubble Space Telescope (HST), we find that the mass peak is located away
from the peak position of stripped gas with statistical significance of >
5{\sigma}. Unlike for the gas sloshing, the velocity inferred from the equation
of state of the excess hot gas is comparable to the adiabatic sound speed
expected for the 20 keV intracluster medium. All of the results support that
the southeast substructure is created by a merger. On the other hand, the
positional offset between the mass and the gas limits the self-interaction
cross section of dark matter to be less than 3.7 h-1 cm2 g-1 (95% CL).Comment: 18 pages, 10 figures, accepted for publication in Ap
Submillimeter detection of the Sunyaev -- Zel'dovich effect toward the most luminous X-ray cluster at z=0.45
We report on the detection of the Sunyaev -- Zel'dovich (SZ) signals toward
the most luminous X-ray cluster RXJ1347-1145 at Nobeyama Radio Observatory (21
and 43 GHz) and at James Clerk Maxwell Telescope (350 GHz). In particular the
latter is the first successful detection of the SZ temperature increment in the
submillimeter band which resolved the profile of a cluster of galaxies. Both
the observed spectral dependence and the radial profile of the SZ signals are
fully consistent with those expected from the X-ray observation of the cluster.
The combined analysis of 21GHz and 350GHz data reproduces the temperature and
core-radius of the cluster determined with the ROSAT and ASCA satellites when
we adopt the slope of the density profile from the X-ray observations.
Therefore our present data provide the strongest and most convincing case for
the detection of the submillimeter SZ signal from the cluster, as well as in
the Rayleigh -- Jeans regime. We also discuss briefly the cosmological
implications of the present results.Comment: 11 pages, The Astrophysical Journal (Letters), in pres
Dense SDM (12-Core × 3-Mode) Transmission Over 527 km With 33.2-ns Mode-Dispersion Employing Low-Complexity Parallel MIMO Frequency-Domain Equalization
Sex-inducing effects toward planarians widely present among parasitic flatworms
Summary
Various parasitic flatworms infect vertebrates for sexual reproduction, often causing devastating diseases in their hosts. Consequently, flatworms are of great socioeconomic and biomedical importance. Although the cessation of parasitic flatworm sexual reproduction is a major target of anti-parasitic drug design, little is known regarding bioactive compounds controlling flatworm sexual maturation. Using the planarian Dugesia ryukyuensis, we observed that sex-inducing substances found in planarians are also widespread in parasitic flatworms, such as monogeneans and flukes (but not in tapeworms). Reverse-phase HPLC analysis revealed the sex-inducing substance(s) eluting around the tryptophan retention time in the fluke Calicophoron calicophorum, consistent with previous studies on the planarian Bipalium nobile, suggesting that the substance(s) is likely conserved among flatworms. Moreover, six of the 18 ovary-inducing substances identified via transcriptome and metabolome analyses are involved in purine metabolism. Our findings provide a basis for understanding and modifying the life cycles of various parasitic flatworms.journal articl
High-Resolution Submillimeter and Near-Infrared Studies of the Transition Disk around Sz 91
To reveal the structures of a transition disk around a young stellar object
in Lupus, Sz 91, we have performed aperture synthesis 345 GHz continuum and
CO(3--2) observations with the Submillimeter Array (\sim1\arcsec--3\arcsec
resolution), and high-resolution imaging of polarized intensity at the
-band by using the HiCIAO instrument on the Subaru Telescope (0\farcs25
resolution). Our observations successfully resolved the inner and outer radii
of the dust disk to be 65 AU and 170 AU, respectively, which indicates that Sz
91 is a transition disk source with one of the largest known inner holes. The
model fitting analysis of the spectral energy distribution reveals an H
mass of M_\sun in the cold (30 K) outer part at
AU by assuming a canonical gas-to-dust mass ratio of 100, although a
small amount ( M_\sun) of hot (180 K) dust possibly
remains inside the inner hole of the disk. The structure of the hot component
could be interpreted as either an unresolved self-luminous companion body (not
directly detected in our observations) or a narrow ring inside the inner hole.
Significant CO(3--2) emission with a velocity gradient along the major axis of
the dust disk is concentrated on the Sz 91 position, suggesting a rotating gas
disk with a radius of 420 AU. The Sz 91 disk is possibly a rare disk in an
evolutionary stage immediately after the formation of protoplanets because of
the large inner hole and the lower disk mass than other transition disks
studied thus far
High-Resolution Submillimeter and Near-Infrared Studies of the Transition Disk around Sz 91
To reveal the structures of a transition disk around a young stellar object in Lupus, Sz 91, we have performed aperture synthesis 345 GHz continuum and CO(32) observations with the Submillimeter Array ( 13 resolution), and high-resolution imaging of polarized intensity at the Ks-band by using the Hi-CIAO instrument on the Subaru Telescope (0.25 resolution). Our observations successfully resolved the inner and outer radii of the dust disk to be 65 and 170AU, respectively, which indicates that Sz 91 is a transition disk source with one of the largest known inner holes. The model fitting analysis of the spectral energy distribution reveals an H2 mass of 2.4 103 M in the cold (T 30 K) outer part at 65 r 170 AU by assuming a canonical gas-to-dust mass ratio of 100, although a small amount ( 3109 M) of hot (T 180 K) dust possibly remains inside the inner hole of the disk. The structure of the hot component could be interpreted as either an unresolved self-luminous companion body (not directly detected in our observations) or a narrow ring inside the inner hole. Significant CO(32) emission with a velocity gradient along the major axis of the dust disk is concentrated on the Sz 91 position, suggesting a rotating gas disk with a radius of 420 AU. The Sz 91 disk is possibly a rare disk in an evolutionary stage immediately after the formation of protoplanets because of the large inner hole and the lower disk mass than other transition disks studied thus far
Human PSF concentrates DNA and stimulates duplex capture in DMC1-mediated homologous pairing
PSF is considered to have multiple functions in RNA processing, transcription and DNA repair by mitotic recombination. In the present study, we found that PSF is produced in spermatogonia, spermatocytes and spermatids, suggesting that PSF may also function in meiotic recombination. We tested the effect of PSF on homologous pairing by the meiosis-specific recombinase DMC1, and found that human PSF robustly stimulated it. PSF synergistically enhanced the formation of a synaptic complex containing DMC1, ssDNA and dsDNA during homologous pairing. The PSF-mediated DMC1 stimulation may be promoted by its DNA aggregation activity, which increases the local concentrations of ssDNA and dsDNA for homologous pairing by DMC1. These results suggested that PSF may function as an activator for the meiosis-specific recombinase DMC1 in higher eukaryotes
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