41 research outputs found
Improvement of Elastomer Elongation and Output for Dielectric Elastomers
The need for light, high-strength, and artificial muscles is growing rapidly. A well-known type of artificial muscle meeting these requirements is the dielectric elastic (DE) type, which uses electrostatic force between electrodes. In hopes of utilizing, it practically for a variety of purposes, research and development is rapidly progressing all over the world as a technology for practical use. Much of the market demand is dominated by more output-focused applications such as DE power suits, DE motors, DE muscles for robots, and larger DE power systems. To meet these demands, the elasticity of the elastomer is very important. In this paper, we discussed what the important factors are for SS curves, viscoelasticity tests, etc. of the dielectric elastomer materials. Recent attempts have been also made to use new carbon foam materials such as SWCNTs and MWCNTs as electrodes for DEs. These electrodes bring the elastomers to a higher level of performance
Dusty ERO Search behind Two Massive Clusters
We performed deep K'-band imaging observations of 2 massive clusters, MS
0451.6-0305 at z = 0.55 and MS 0440.5+0204 at z = 0.19, for searching
counterparts of the faint sub-mm sources behind these clusters, which would
provide one of the deepest extremely red object(ERO) samples. Comparing our
near-infrared images with optical images taken by the Hubble Space Telescope
and by the Subaru Telescope, we identified 13 EROs in these fields. The sky
distributions of EROs are consistent with the previous results, that there is a
sign of strong clustering among detected EROs. Also, the surface density with
corrected lensing amplification factors in both clusters are in good agreement
with that derived from previous surveys. We found 7 EROs and 3 additional very
red objects in a small area (\sim 0.6 arcmin^2) of the MS 0451.6-0305 field
around an extended SCUBA source. Many of their optical and near-infrared colors
are consistent with dusty star-forming galaxies at high redshifts(z \sim
1.0-4.0), and they may be constituting a cluster of dusty starburst galaxies
and/or lensed star-forming galaxies at high redshift. Their red J-K' colors and
faint optical magnitudes suggest they are relatively old massive stellar
systems with ages(>300 Mega years) suffering from dust obscuration. We also
found a surface-density enhancement of EROs around the SCUBA source in the MS
0440.5+0204 field.Comment: 19 pages, 11 figures, Latex(using pasj00.cls). To be published in
PASJ vol 55, No. 4(Aug 2003
A toxicoproteomic study on cardioprotective effects of pre-administration of docetaxel in a mouse model of adriamycin-induced cardiotoxicity.
Studies suggest that pre-administration of docetaxel (DOC) in adriamycin (ADR)-DOC combination anticancer therapy results in stronger antitumor effects and fewer ADR-induced cardiotoxic deaths in mouse model, yet no mechanism explaining this effect has been established. The aim of this study was to identify cellular processes in mouse heart tissue affected by different ADR/DOC dosing protocols using a toxicoproteomic approach. We applied fluorogenic derivatization-liquid chromatography-tandem mass spectrometry (FD-LC-MS/MS) - which consists of fluorogenic derivatization, separation and fluorescence detection by LC, and identification by LC-tandem mass spectrometry - to the proteomic analysis of heart tissue from control, intermittent-dosing (DOC-ADR), and simultaneous-dosing (ADR&DOC) groups. In DOC-ADR group, ADR was administered 12h after DOC injection; in ADR&DOC group, both drugs were administered simultaneously; in control group, saline was administered at the same timing as ADR injection of other groups. Heart samples were isolated from all mice 1 week after the treatment. The highly reproducible and sensitive method (FD-LC-MS/MS) identified nine proteins that were differentially expressed in heart tissue of control and the two treatment groups; seven of these nine proteins participate in cellular energy production pathways, including glycolysis, the tricarboxylic acid cycle, and the mitochondrial electron transport chain. Significantly higher expression of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was observed in the DOC-ADR group, the group with the fewer cardiotoxic deaths, than in the ADR&DOC group. Therefore, GAPDH may have potential as a drug target for protective intervention and a biomarker for evaluation of the cardioprotective effects in pre-clinical studies
Decomposition of the Superwind in M82
We present new optical images (, , and H) of the archetypical
starburst/superwind galaxy M82 obtained with the 8.2 m Subaru Telescope to
reveal new detailed structures of the superwind-driven nebula and the
high-latitude dark lanes. The emission-line nebula is decomposed into (1) a
ridge-dominated component comprising numerous filament/loop sub-structures
whose overall morphology appears as a pair of narrow cylinders, and (2) a
diffuse component extended over much wider opening angle from the nucleus. We
suggest that these two components have different origins. The ridge-dominated
component appears as a pair of cylinders rather than a pair of cones. Since
this morphological property is similar to that of hot plasma probed by soft
X-ray, this component seems to surround the hot plasma. On the other hand, the
diffuse component may arise from dust grains which scatter stellar light from
the galaxy. Since inner region of this component is seen over the prominent ^^
^^ X"-shaped dark lanes streaming out from the nuclear region and they can be
reproduced as a conical distribution of dust grains, there seems to be a dusty
cold outflow as well as the hot one probed by soft X-ray and shock-excited
optical emission lines. If this is the case, the presence of such high-latitude
dust grains implies that neutral gaseous matter is also blown out during the
course of the superwind activity.Comment: 12 pages, 6 figures. Accepted for publication in PAS
A Shock-Induced Pair of Superbubbles in the High-Redshift Powerful Radio Galaxy MRC 0406-244
We present new optical spectroscopy of the high-redshift powerful radio
galaxy MRC 0406244 at redshift of 2.429. We find that the two extensions
toward NW and SE probed in the rest-frame ultraviolet image are heated mainly
by the nonthermal continuum of the active galactic nucleus. However, each
extension shows a shell-like morphology, suggesting that they are a pair of
superbubbles induced by the superwind activity rather than by the interaction
between the radio jet and the ambient gas clouds. If this is the case, the
intense starburst responsible for the formation of superbubbles could occur
yr ago. On the other hand, the age of the radio jets may
be of the order of yr, being much shorter than the starburst age.
Therefore, the two events, i.e., the starburst and the radio-jet activities,
are independent phenomena. However, their directions of the expanding motions
could be governed by the rotational motion of the gaseous component in the host
galaxy. This idea appears to explain the alignment effect of MRC 0406244.Comment: 4 pages (emulateapj.sty), Fig. 1 (jpeg) + Fig.2 (eps). Accepted for
publications in ApJ (Letters
Current Performance and On-Going Improvements of the 8.2 m Subaru Telescope
An overview of the current status of the 8.2 m Subaru Telescope constructed
and operated at Mauna Kea, Hawaii, by the National Astronomical Observatory of
Japan is presented. The basic design concept and the verified performance of
the telescope system are described. Also given are the status of the instrument
package offered to the astronomical community, the status of operation, and
some of the future plans. The status of the telescope reported in a number of
SPIE papers as of the summer of 2002 are incorporated with some updates
included as of 2004 February. However, readers are encouraged to check the most
updated status of the telescope through the home page,
http://subarutelescope.org/index.html, and/or the direct contact with the
observatory staff.Comment: 18 pages (17 pages in published version), 29 figures (GIF format),
This is the version before the galley proo
Toxicoproteomic analysis of a mouse model of nonsteroidal anti-inflammatory drug-induced gastric ulcers
Nonsteroidal anti-inflammatory drugs (NSAIDs) are valuable agents; however, their use has been limited by their association with mucosal damage in the upper gastrointestinal tract. NSAIDs inhibit cyclooxygenase and consequently block the synthesis of prostaglandins, which have cytoprotective effects in gastric mucosa; these effects on prostaglandins have been thought to be major cause of NSAID-induced ulceration. However, studies indicate that additional NSAID-related mechanisms are involved in formation of gastric lesions. Here, we used a toxicoproteomic approach to understand cellular processes that are affected by NSAIDs in mouse stomach tissue during ulcer formation. We used fluorogenic derivatization-liquid chromatography-tandem mass spectrometry (FD-LC-MS/MS)-which consists of fluorogenic derivatization, separation and fluorescence detection by LC, and identification by LC-tandem mass spectrometry-in this proteomic analysis of pyrolic stomach from control and diclofenac (Dic)-treated mice. FD-LC-MS/MS results were highly sensitive; 10 differentially expressed proteins were identified, and all 10 were more highly expressed in Dic-treated mice than in control mice. Specifically, expression levels of 78. kDa glucose-regulated protein (GRP78), heat shock protein beta-1 (HSP27), and gastrin were more than 3-fold higher in Dic-treated mice than in control mice. This study represents a first step to ascertain the precise actors of early NSAID-induced ulceration
Influence of charge leakage on energy density of dielectric elastomer generator with transversely restrained configuration
Dielectric elastomer generator (DEG) could harvest electrical energy from cyclic deformation by changing the capacitance of dielectric elastomer (DE). Due to its advantages of light weight and high energy density, DEG has great development potential in the utilization of renewable mechanical energy. A key bottleneck restricting the development of DEG is the charge leakage phenomenon, which can reduce the DEG energy density. In this work, the effect of the charge leakage phenomenon on DEG energy density was investigated based on experiments and theoretical simulations. The results showed that with the increase of bias voltage and transverse pre-stretching ratio, the DEG energy density of quadrangular and triangular harvesting cycle first increased and then decreased, and the maximum experimental energy densities of the DEG with transversely restrained configuration were 120 mJ/g and 187 mJ/g, respectively. In addition, a simulation method for calculating the DEG energy density based on charge leakage model was proposed to quantitatively analyze the influence of charge leakage on DEG energy density. The simulation results showed that the energy density of the quadrangular harvesting cycle could be significantly improved by decreasing the charge leakage of the DE film