<Note>Thermal Properties of Newly Developed Acetylated Cellulose

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。A novel acetylated cellulose called cellulose oligo-oxymethylene ether acetate, COAc, was prepared by the homogeneous reaction in Paraformaldehyde/DMSO medium. Measurements of thermal deformation for COAc series with different degree of substitution (DS) revealed that the asending deformation for all samples went off at about 170℃. Heat treatment above this temperature caused remarkable change in thermal properties of COAc. A large weight loss of COAc was also observed in the region above this temperature From these results, the side chain of COAc was concluded to decompose above 170℃

Cassini multi-instrument assessment of Saturn's polar cap boundary

We present the first systematic investigation of the polar cap boundary in Saturn's high-latitude magnetosphere through a multi-instrument assessment of various Cassini in situ data sets gathered between 2006 and 2009. We identify 48 polar cap crossings where the polar cap boundary can be clearly observed in the step in upper cutoff of auroral hiss emissions from the plasma wave data, a sudden increase in electron density, an anisotropy of energetic electrons along the magnetic field, and an increase in incidence of higher-energy electrons from the low-energy electron spectrometer measurements as we move equatorward from the pole. We determine the average level of coincidence of the polar cap boundary identified in the various in situ data sets to be 0.34° ± 0.05° colatitude. The average location of the boundary in the southern (northern) hemisphere is found to be at 15.6° (13.3°) colatitude. In both hemispheres we identify a consistent equatorward offset between the poleward edge of the auroral upward directed field-aligned current region of ~1.5–1.8° colatitude to the corresponding polar cap boundary. We identify atypical observations in the boundary region, including observations of approximately hourly periodicities in the auroral hiss emissions close to the pole. We suggest that the position of the southern polar cap boundary is somewhat ordered by the southern planetary period oscillation phase but that it cannot account for the boundary's full latitudinal variability. We find no clear evidence of any ordering of the northern polar cap boundary location with the northern planetary period magnetic field oscillation phase

Performance measurement of the 8-input SQUIDs for TES frequency domain multiplexing

金沢大学大学院理工研究域数物科学系We report on performance of 8-input superconducting quantum interference devices (SQUIDs) for multiplexing transition-edge sensor signals by using frequency-domain multiplexing. We found the typical critical current and the flux noise to be 17-19 μA and 0.7-1.1 μΦ0/Hz, respectively. We also measured the crosstalk current between the input coils of the SQUIDs, and found that the mutual inductance was consistent with the design value, 800 pH. We confirmed that the cross talk current due to the mutual inductance was reduced by the flux-locked-loop (FLL) feedback, and its reduction rate was consistent with 1/(1+L), where L is the FLL feedback gain. We also show the result of 2-channel DC-driven TES signals readout using the 8-input SQUIDs. © Springer Science+Business Media, LLC 2008

Electron Density Distributions in Saturn's Ionosphere

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.Between 26 April and 15 September 2017, Cassini executed 23 highly inclined Grand Finale orbits through a new frontier for space exploration, the narrow region between Saturn and the D Ring, providing the first opportunity for obtaining in situ ionospheric measurements. During the Grand Finale orbits, the Radio and Plasma Wave Science instrument observed broadband whistler mode emissions and narrowband upper hybrid frequency emissions. Using known wave propagation characteristics of these two plasma wave modes, the electron density is derived over a broad range of ionospheric latitudes and altitudes. A two‐part exponential scale height model is fitted to the electron density measurements. The model yields a double‐layered ionosphere with plasma scale heights of 545/575 km for the northern/southern hemispheres below 4,500 km and plasma scale heights of 4,780/2,360 km for the northern/southern hemispheres above 4,500 km. The interpretation of these layers involves the interaction between the rings and the ionosphere

An Estimate of the Dust Pickup Currents at Enceladus

The electrodynamic environment at Enceladus is often assumed to be driven exclusively by ions produced from the moon's south polar plume. In this presentation, we demonstrate that acceleration of moon-originating submicron dust by the reduced co-rotating E-field is capable of creating a substantial current perpendicular to the magnetic field. This pickup current may be comparable to the ion pickup current, and may be large enough to deflect the local magnetic field. We will analyze observations from the Langmuir Probe that is a component of Cassini's Radio and Plasma Wave Science (RPWS) package, along with associated plasma waves that reveal electron concentrations. We will especially examine the observations from the 12 March 2008 spacecraft passage by the body, where the spacecraft was moving primarily southward taking it along-side the jet/plume emitted from the south pole of the moon. The region of dust pickup is found to originate about 3-5 Enceladus radii northward of the moon, and extends to at least 10 radii southward of the moon. We attempt to quantify the dust pickup current and describe the effect the current might have on the overall magnetoplasma and E-field environment in the vicinity of the body

Protein Phosphatase Magnesium Dependent 1A (PPM1A) Plays a Role in the Differentiation and Survival Processes of Nerve Cells

The serine/threonine phosphatase type 2C (PPM1A) has a broad range of substrates, and its role in regulating stress response is well established. We have investigated the involvement of PPM1A in the survival and differentiation processes of PC6-3 cells, a subclone of the PC12 cell line. This cell line can differentiate into neuron like cells upon exposure to nerve growth factor (NGF). Overexpression of PPM1A in naive PC6-3 cells caused cell cycle arrest at the G2/M phase followed by apoptosis. Interestingly, PPM1A overexpression did not affect fully differentiated cells. Using PPM1A overexpressing cells and PPM1A knockdown cells, we show that this phosphatase affects NGF signaling in PC6-3 cells and is engaged in neurite outgrowth. In addition, the ablation of PPM1A interferes with NGF-induced growth arrest during differentiation of PC6-3 cells

Investigating Mercury's Environment with the Two-Spacecraft BepiColombo Mission

The ESA-JAXA BepiColombo mission will provide simultaneous measurements from two spacecraft, offering an unprecedented opportunity to investigate magnetospheric and exospheric dynamics at Mercury as well as their interactions with the solar wind, radiation, and interplanetary dust. Many scientific instruments onboard the two spacecraft will be completely, or partially devoted to study the near-space environment of Mercury as well as the complex processes that govern it. Many issues remain unsolved even after the MESSENGER mission that ended in 2015. The specific orbits of the two spacecraft, MPO and Mio, and the comprehensive scientific payload allow a wider range of scientific questions to be addressed than those that could be achieved by the individual instruments acting alone, or by previous missions. These joint observations are of key importance because many phenomena in Mercury's environment are highly temporally and spatially variable. Examples of possible coordinated observations are described in this article, analysing the required geometrical conditions, pointing, resolutions and operation timing of different BepiColombo instruments sensors.Peer reviewe