614 research outputs found
Current-induced domain wall motion in a nanowire with perpendicular magnetic anisotropy
We study theoretically the current-induced magnetic domain wall motion in a
metallic nanowire with perpendicular magnetic anisotropy. The anisotropy can
reduce the critical current density of the domain wall motion. We explain the
reduction mechanism and identify the maximal reduction conditions. This result
facilitates both fundamental studies and device applications of the current-
induced domain wall motion
H2 pressure swing adsorption for IGCC power plant and techno-economic analysis of integrating PSA to IGCC with carbon capture
Carbon capture and sequestration technologies emerge as the effectual remediation processes to reduce CO2 emissions from coal power plants. Integrated gasification combined cycle (IGCC) is a representative technology for utilizing coal as feedstock and is consequently playing a more important role to cover the global energy demand.
The IGCC produces H2-rich mixture at high pressures (30-35 bar) after capturing CO2. It is reported that the high purity H2 recovered from the IGCC process can be economically supplied to a hydrogen turbine or fuel cell. And a PSA process is a strong candidate to produce high purity H2 from the IGCC effluent gas. However, due to higher operating pressure than the present H2 PSA processes, reducing the operating costs and efficiency has emerged as one of the key issues.
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Squeezing Limit of the Josephson Ring Modulator as a Non-Degenerate Parametric Amplifier
Two-mode squeezed vacuum states are a crucial component of quantum
technologies. In the microwave domain, they can be produced by Josephson ring
modulator which acts as a three-wave mixing non-degenerate parametric
amplifier. Here, we solve the master equation of three bosonic modes describing
the Josephson ring modulator with a novel numerical method to compute squeezing
of output fields and gain at low signal power. We show that the third-order
interaction from the three-wave mixing process intrinsically limits squeezing
and reduces gain. Since our results are related to other general cavity-based
three-wave mixing processes, these imply that any non-degenerate parametric
amplifier will have an intrinsic squeezing limit in the output fields.Comment: 6+6 pages, 4 figure
Bound for Gaussian-state Quantum illumination using direct photon measurement
We present bound for quantum illumination with Gaussian state when using
on-off detector or photon number resolving detector, where its performance is
evaluated with signal-to-noise ratio. First, in the case of coincidence
counting, the best performance is given by two-mode squeezed vacuum (TMSV)
state which outperforms coherent state and classically correlated thermal (CCT)
state. However coherent state can beat the TMSV state with increasing signal
mean photon number when using the on-off detector. Second, the performance is
enhanced by taking Fisher information approach of all counting probabilities
including non-detection events. In the Fisher information approach, the TMSV
state still presents the best performance but the CCT state can beat the TMSV
state with increasing signal mean photon number when using the on-off detector.
We also show that displaced squeezed state exhibits the best performance in the
single-mode Gaussian state.Comment: 5 pages, 2 figures, comments welcom
The influence of game genre on Internet gaming disorder
Although Internet gaming disorder (IGD) has been investigated in detail, minimal research has been conducted regarding the influence of different game genres on IGD. The aim of this study is to compare the characteristics of members of game genre-specific groups with IGD and to identify factors associated with IGD status in each group in a large sample of adults. Methods Internet games were categorized into four genres: real-time strategy games, massive multiplayer online role-playing games (MMORPG), sport games, and first-person shooter (FPS) games. Participants (n = 2,923) who usually played one of these games completed an anonymous online survey that collected sociodemographic, game usage pattern, and psychopathological assessment data. Results MMORPG and FPS game players more frequently met the criteria for IGD than participants in the other two groups. Differences between the IGD-suspected gamers within the genre-specific groups were observed for a few items, such as average game-playing time and the subscales of the behavioral activation system; however, the factors that contributed to the development of IGD within each game genre-specific group were found to be considerably different. Discussion and conclusions The findings of this study suggest that IGD is a stable psychiatric diagnosis encompassing users of a broad range of game genres. In addition, the development of strategies for the prevention of and early intervention on individuals at high risk for developing IGD may require consideration of the distinct characteristics identified as effective predictors of IGD in users of each game genre
Risk Factors for Posterior Cage Migration after Lumbar Interbody Fusion Surgery
Study DesignA retrospective clinical case series.PurposeTo determine the strength of association between cage retropulsion and its related factors.Overview of LiteratureLumbar interbody fusion with cage can obtain a firm union and can restore the disc height with normal sagittal and coronal alignment. Although lumbar interbody fusion procedures have satisfactory clinical outcomes, peri- and postoperative complications regarding the cage remain challenging.MethodsFrom January 2006 to June 2016, 1,047 patients with lumbar degenerative disc disease who underwent posterior lumbar interbody fusion or transforaminal interbody fusion at Gyeongsang National University Hospital were enrolled. Medical records and pre- and postoperative radiographs were reviewed to identify significant cage retropulsion-related factors. The associations between cage retropulsion with various risk factors were evaluated by calculating odds ratios (ORs) and 95% confidence intervals (CIs) using multiple logistic regression analysis.ResultsOf 1,229 disc levels, 16 cases (1.3%, 10 men and 6 women) had cage retropulsion. Univariate analysis revealed no significant differences between the cage retropulsion group and the no cage retropulsion group with regard to demographic data such as age, sex, weight, height, body mass index (BMI), smoking habits, presence of osteoporosis, and duration of follow-up. Multivariate analysis revealed that low BMI (OR, 0.875; 95% CI, 0.771–0.994; p=0.040), presence of screw loosening (OR, 27.400; 95% CI, 7.818–96.033; p<0.001), and pear-shaped disc (OR, 9.158; 95% CI, 2.455–34.160; p=0.001) were significantly associated with cage retropulsion.ConclusionsThis study demonstrated that low BMI, loosening of posterior instrumentation, and pear-shaped disc were associated with cage retropulsion after lumbar interbody fusion. Therefore, when performing lumbar interbody fusion with a cage, surgeons should have skillful surgical techniques for firm fixation to prevent cage retropulsion, particularly in non-obese patients
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