643 research outputs found
Statistical quantum operation
A generic unital positive operator-valued measure (POVM), which transforms a
given stationary pure state to an arbitrary statistical state with perfect
decoherence, is presented. This allows one to operationally realize
thermalization as a special case. The loss of information due to randomness
generated by the operation is discussed by evaluating the entropy.
Thermalization of the bipartite spin-1/2 system is discussed as an illustrative
example.Comment: 10 pages, no figure
Stationary photon-atom entanglement and flow equation
Stationary photon-atom entanglement is discussed by applying the method of
flow equation to the Jaynes-Cummings model. A nonlocal continuous unitary
transformation is explicitly constructed and the associated positive
operator-valued measures for the photons and atom are obtained. Then, flow of
the entanglement entropy is analyzed. A comment is also made on implementing
the unitary operation in the method of flow equation. This method may offer a
new strategy for quantum-state engineering.Comment: 21 pages, no figure
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Combination of high-resolution cone beam computed tomography and metal artefact reduction software: a new image fusion technique for evaluating intracranial stent apposition after aneurysm treatment.
We introduce a new imaging technique to improve visualisation of stent apposition after endovascular treatment of brain aneurysms employing high-resolution cone beam CT and three-dimensional digital subtraction angiography. After performing a stent-assisted coil embolisation of brain aneurysm, the image datasets were processed with a metal artefact reduction software followed by the automated image fusion programmes. Two patients who underwent aneurysm coiling using a Neuroform stent were evaluated. The reconstructed 3D images showed a detailed structure of the stent struts and identified malappositions of the deployed stents. Case 1 showed good apposition on the outer curvature side of the carotid siphon, while the inner curvature side showed prominent malapposition. Case 2, with multiple aneurysms, showed good apposition on both outer and inner curvature sides, although inward prolapse of the struts was observed. This new imaging technique may help evaluate stent apposition after the endovascular aneurysm treatment
Performance of segment type switched reluctance motor using grain-oriented
Authors developed a segment type switched reluctance motor (SRM) as a rare earth less motor. The object is to reduce the acoustic noise and vibration as well as improve the torque characteristics. In this paper, we propose the performance improve method using grain-oriented electric steel as the segment core. The validity is confirmed experimentally.15th International Conference on Electrical Machines and Systems, ICEMS 2012; Sapporo; Japan; 21 October 2012 ~ 24 October 201
Plasma calcium and calcitonin levels at food intake in eels and goldfish
金沢大学環日本海域環境研究センター生物多様性研究部門In order to examine whether calcitonin plays an important role in Ca homeostasis of teleosts, such as suppressing hypercalcemia at food intake, we compared the plasma Ca levels and calcitonin levels in eels fed normally with eels starved for one week (Experiment I), and in goldfish administered with a high Ca-consomme solution into the digestive tract with goldfish given physiological saline solution (Experiment II). In Experiment I, the plasma Ca levels and calcitonin levels in the fed eels were significantly higher than those in the starved eels after one week. In Experiment II, the plasma Ca levels in the high Ca-treated goldfish were significantly higher than those in the saline-treated goldfish after 1 hr and 3 hr. The number of goldfish showing over 500 pg/ml of plasma calcitonin was significantly higher in the high Ca-treated group than in the saline-treated group. From the results of both experiments, we conclude that in these two species, Ca and/or nutriment absorbed via the digestive tract may affect plasma calcitonin levels. However, more experiments are needed to directly demonstrate that calcitonin suppresses hypercalcemia at food intake
Characteristics of a half-wave rectified brushless synchronous generator
The paper proposes the half-wave rectified brushless synchronous generator and analyzes the basic characteristics using the finite element method. It is based on the half-wave rectified excitation theory and doesn\u27t need brush and slip ring system or permanent magnets for field excitation.7th International Power Electronics Conference, IPEC-Hiroshima - ECCE Asia 2014; Hiroshima; Japan; 18 May 2014 through 21 May 201
A characteristic experiment of 4-phase segment type switched reluctance motor
Authors developed a novel segment type switched reluctance motor (SRM) as a rare earth less motor. The torque was increased by 40% and the radial force was decreased by 76% compared with the same size VR type SRM. Increasing the average torque, however, caused increasing torque ripple. In this paper we propose a 4-phase segment type switched reluctance motor and show that the torque ripple can be decreased by controlling the excitation current.15th International Conference on Electrical Machines and Systems, ICEMS 2012; Sapporo; Japan; 21 October 2012 ~ 24 October 201
On the improvement performance of a dual rotor segment type SRM
A dual rotor segment type switched reluctance motor (SRM) is proposed for flat configuration. It has toroidal stator coil and has inner rotor as well as outer rotor. The performance characteristics are calculated using finite element method. On a flat type SRM, leakage flux is greatly generated at both side coil. To reduce the leakage flux we propose shield structure. Effectiveness of the shield structure is verified analytically.2013 IEEE 10th International Conference on Power Electronics and Drive Systems, PEDS 2013; Kitakyushu; Japan; 22 April 2013 through 25 April 201
FOREVER22: the first bright galaxies with population III stars at redshifts and comparisons with JWST data
We study the formation of the first galaxies in overdense regions modelled by
the FORmation and EVolution of galaxies in Extremely overdense Regions
motivated by SSA22 (FOREVER22) simulation project. Our simulations successfully
reproduce the star formation rates and the relations
of candidate galaxies at observed by the James Webb Space
Telescope (JWST). We suggest that the observed galaxies are hosted by
dark-matter haloes with and are in
short-period starburst phases. On the other hand, even simulated massive
galaxies in overdense regions cannot reproduce the intense star formation rates
and the large stellar masses of observed candidates at . Also, we
show that the contribution of population III stars to the UV flux decreases as
the stellar mass increases and it is a few percent for galaxies with . Therefore, a part of the observed flux by
JWST could be the light from population III stars. Our simulations suggest that
the UV flux can be dominated by population III stars and the UV-slope shows
if future observations would reach galaxies with at of which the mass fraction
of population III stars can be greater than 10 percent.Comment: 9 pages, 6 figures, accepted for publication in MNRA
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