779 research outputs found
Metal-Insulator Transition and Spin Degree of Freedom in Silicon 2D Electron Systems
Magnetotransport in 2DES's formed in Si-MOSFET's and Si/SiGe quantum wells at
low temperatures is reported. Metallic temperature dependence of resistivity is
observed for the n-Si/SiGe sample even in a parallel magnetic field of 9T,
where the spins of electrons are expected to be polarized completely.
Correlation between the spin polarization and minima in the diagonal
resistivity observed by rotating the samples for various total strength of the
magnetic field is also investigated.Comment: 3 pages, RevTeX, 4 eps-figures, conference paper (EP2DS-13
Dynamics of Permanent-Magnet Biased Active Magnetic Bearings
Active magnetic radial bearings are constructed with a combination of permanent magnets to provide bias forces and electromagnets to generate control forces for the reduction of cost and the operating energy consumption. Ring-shaped permanent magnets with axial magnetization are attached to a shaft and share their magnet stators with the electromagnets. The magnet cores are made of solid iron for simplicity. A simplified magnetic circuit of the combined magnet system is analyzed with linear circuit theory by approximating the characteristics of permanent magnets with a linear relation. A linearized dynamical model of the control force is presented with the first-order approximation of the effects of eddy currents. Frequency responses of the rotor motion to disturbance inputs and the motion for impulsive forces are tested in the non-rotating state. The frequency responses are compared with numerical results. The decay of rotor speed due to magnetic braking is examined. The experimental results and the presented linearized model are similar to those of the all-electromagnetic design
Apparent effect of dust extinction on the observed outflow velocity of ionized gas in galaxy mergers
In this study, we examine photoionization outflows during the late stages of
galaxy mergers, with a specific focus on the relation between observed velocity
of outflowing gas and the apparent effects of dust extinction. We used the
N-body/smoothed particle hydrodynamics (SPH) code ASURA for galaxy merger
simulations. These simulations concentrated on identical galaxy mergers
featuring supermassive black holes (SMBHs) of 10 M and gas
fractions of 30\% and 10 \%. From the simulation data, we derived velocity and
velocity dispersion diagrams for the AGN-driven ionized outflowing gas. Our
findings show that high-velocity outflows with velocity dispersions of 500 km
s or greater can be observed in the late stages of galactic mergers.
Particularly, in buried AGNs, both the luminosity-weighted outflow velocity and
velocity dispersion increase owing to the apparent effects of dust extinction.
Owing to these effects, the velocity--velocity dispersion diagrams display a
noticeable blue-shifted tilt in models with higher gas fractions. Crucially,
this tilt is not influenced by the AGN luminosity but emerges from the
observational impacts of dust extinction. Our results imply that the observed
high-velocity \OIII outflow exceeding 1000 km s in buried AGNs may be
linked to the dust extinction that occurs during the late stages of gas-rich
galaxy mergers.Comment: 14 pages, accepted for publication in Ap
Why summer harvesting of common reed is a viable management practice?
A wetland stand of Phragmites australis (Cav.) Trin. Ex Steud., located in Akigase Park, saitama Prefecture, Japan was investigated to study the effects of summer harvesting. The effect from harvesting in June, when carbohydrate supplies in the rhizomes are at a minimum, was compared with harvesting in July, when rhizomes are recharged with carbohydrates. From April through Octover 2000, biomass of above and below-ground organs and bukj density (Prhiz, an easily measured parameter proportional to the quantity of non-structural polysaccharide reserves) of rhizomes of different ages was measured. The present study quantitatively analysed the effects exerted on the refeneration dynamics of shoots and storage dynamics of rhizomes of a stand of P.australis subjected to summer harvesting. Summer harvesting did not exert significant effects (increase/decrease) on shoot biomass at the end of the same growing season. However, the seasonal pattern in rhizome storage showed a marked variation between the two harvested stands. The rate of increase in Prhiz of different age categories of rhizomes after shoot harvesting showed that the rate of Prhiz increase was negatively and linearly correlated with rhizome age in both June-cut and July-cut stands. Also cutting in June rather than July enabled to retard the recharging capacity of P.australis rhizomes. The study identified the seasonal changes of the quality of the rhizome reserves as essential for proper vegetation management.Article信州大学山地水環境教育研究センター研究報告 2: 41-46(2004)departmental bulletin pape
Age specific rhizome dynamics of Phragmites australis and their effects on nutrient cycling.
Characteristics of rhizome resource storage of common reed, Phragmites australis (Cav.) Trin. Ex Steudel, were investigated associated with the aboveground biomass in terms of rhizome age category. Age-specific rhizome biomass and total nonstructual carbohydrate (TNC), and standing stock of aboveground biomass were observed monthlu. The biomass of one- or two-year old rhizomes did not reduce during the growing season, while a large reduction was observed with older rhizomes. TNC concentration declines twice a year, first in May before the recovery in late spring and second after August, followed by recovery in November. The amount of remobilized TNC is negatively correlated to rhizome age during spring growth and autumnal translocation, except for one year old rhizomes. Analyses of carbon budgets implies that the spring decline is caused by the remobilization of TNC for the aboveground biomass growth and rhizome respiration, and that of autumn is mainly due to respiration, while translocation of dead shoots contributes to the subsequent recovery of rhizome biomass. The nitrogen contents substantially decrease decrease during the second summer, however, phosphorous contents reduce gradually during the whole year.Article信州大学山地水環境教育研究センター研究報告 2: 47-52(2004)departmental bulletin pape
Dependence of conformational stability on hydrophobicity of the amino acid residue in a series of variant proteins substituted at a unique position of tryptophan synthase alpha subunit.
Evaluation of cases of mammoplasty with the areolar inferior pedicle technique
INTRODUCTION: Mammoplasty is one of the most common plastic surgeries in Brazil. Among the surgical techniques described in the literature, the areolar inferior pedicle technique is the most significant because of its versatility, safety, and satisfactory aesthetic results. This study avaluated cases of mammoplasty with the areolar inferior pedicle technique performed by the author, and to propose a small change in the attachment of the pedicle to the pectoralis major muscle.
METHODS: A total of 74 patients underwent the surgery from June 2007 to December 2014.
RESULTS: The average patient age was 35.63 years; the mean body mass index was 25.8; and the mean follow-up duration was 28 months. Complications occurred in 33.76% of the cases, and the average amount of resected tissue was 585 g. The degree of satisfaction was excellent or good in 93% of the cases. The sensitivity of the areolar-papillary complex (APC) was maintained in 72% of left-breast reconstructions and 77% of right-breast reconstructions. Moreover, there was a complete loss of sensitivity in 3% of left-breast cases.
CONCLUSION: The use of mammoplasty with the areolar inferior pedicle was versatile and safe, and produced favorable outcomes. In addition, the sensitivity of the APC was adequately maintained. Further studies might confirm the importance of the change in fixation of the pedicle suggested in this study
Quantitative study of valence and configuration interaction parameters of the Kondo semiconductors CeM2Al10 (M = Ru, Os and Fe) by means of bulk-sensitive hard x-ray photoelectron spectroscopy
The occupancy of the 4f^n contributions in the Kondo semiconductors
CeM2Al10(M = Ru, Os and Fe) has been quantitatively determined by means of
bulk-sensitive hard x-ray photoelectron spectroscopy (HAXPES) on the Ce 3d core
levels. Combining a configuration interaction scheme with full multiplet
calculations allowed to accurately describe the HAXPES data despite the
presence of strong plasmon excitations in the spectra. The configuration
interaction parameters obtained from this analysis -- in particular the
hybridization strength V_eff and the effective f binding energy Delta_f --
indicate a slightly stronger exchange interaction in CeOs2Al10 compared to
CeRu2Al10, and a significant increase in CeFe2Al10. This verifies the
coexistence of a substantial amount of Kondo screening with magnetic order and
places the entire CeM2Al10 family in the region of strong exchange
interactions.Comment: 9 pages, 4 figures, submitted to Physical Review
Alliinase from Ensifer adhaerens and Its Use for Generation of Fungicidal Activity
A bacterium Ensifer adhaerens FERM P-19486 with the ability of alliinase production was isolated from a soil sample. The enzyme was purified for characterization of its general properties and evaluation of its application in on-site production of allicin-dependent fungicidal activity. The bacterial alliinase was purified 300-fold from a cell-free extract, giving rise to a homogenous protein band on polyacrylamide gel electrophoresis. The bacterial alliinase (96 kDa) consisted of two identical subunits (48 kDa), and was most active at 60°C and at pH 8.0. The enzyme stoichiometrically converted (-)-alliin ((-)-S-allyl-L-cysteine sulfoxide) to form allicin, pyruvic acid, and ammonia more selectively than (+)-alliin, a naturally occurring substrate for plant alliinase ever known. The C-S lyase activity was also detected with this bacterial enzyme when S-alkyl-L-cysteine was used as a substrate, though such a lyase activity is absolutely absent in alliinase of plant origin. The enzyme generated a fungicidal activity against Saccharomyces cerevisiae in a time- and a dose-dependent fashion using alliin as a stable precursor. Alliinase of Ensifer adhaerens FERM P-19486 is the enzyme with a novel type of substrate specificity, and thus considered to be beneficial when used in combination with garlic enzyme with respect to absolute conversion of (±)-alliin to allicin
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