1,532 research outputs found

    On Generalised Free Products of Conjugacy Separable Groups

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    AbstractIn this paper we prove that a free product of conjugacy separable groupsAandB, amalgamating a cyclic subgroup, is conjugacy separable ifAandBare subgroup separable, cyclic conjugacy separable, 2-free, and residuallyp-finite, for all prime numbersp. The following result is an example of the applications we obtain as consequences of our main theorem. LetAandBeach be a free product of surface groups, amalgamating a maximal cyclic subgroup. Then a free product ofAandB, amalgamating a cyclic subgroup, is conjugacy separable

    Separability Properties of Certain Tree Products of Groups

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    AbstractWe introduce the concept of finite compatibility to prove certain double coset separability of tree products of central subgroup separable groups. We also prove a criterion for the conjugacy separability of generalized free products of two conjugacy separable groups amalgamating a central subgroup in one of the factors. Using this we prove that tree products of finitely many central subgroup separable and conjugacy separable groups are conjugacy separable. We apply the results to polycyclic-by-finite groups and groups of linkages of torus knots

    Magnetic moment of hyperons in nuclear matter by using quark-meson coupling models

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    We calculate the magnetic moments of hyperons in dense nuclear matter by using relativistic quark models. Hyperons are treated as MIT bags, and the interactions are considered to be mediated by the exchange of scalar and vector mesons which are approximated as mean fields. Model dependence is investigated by using the quark-meson coupling model and the modified quark-meson coupling model; in the former the bag constant is independent of density and in the latter it depends on density. Both models give us the magnitudes of the magnetic moments increasing with density for most octet baryons. But there is a considerable model dependence in the values of the magnetic moments in dense medium. The magnetic moments at the nuclear saturation density calculated by the quark meson coupling model are only a few percents larger than those in free space, but the magnetic moments from the modified quark meson coupling model increase more than 10% for most hyperons. The correlations between the bag radius of hyperons and the magnetic moments of hyperons in dense matter are discussed.Comment: substantial changes in the text, submitted to PL

    Efficient magneto-optical trapping of Yb atoms with a violet laser diode

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    We report the first efficient trapping of rare-earth Yb atoms with a high-power violet laser diode (LD). An injection-locked violet LD with a 25 mW frequency-stabilized output was used for the magneto-optical trapping (MOT) of fermionic as well as bosonic Yb isotopes. A typical number of 4×1064\times 10^6 atoms for 174^{174}Yb with a trap density of 1×108/\sim 1\times10^8/cm3^3 was obtained. A 10 mW violet external-cavity LD (ECLD) was used for the one-dimensional (1D) slowing of an effusive Yb atomic beam without a Zeeman slower resulting in a 35-fold increase in the number of trapped atoms. The overall characteristics of our compact violet MOT, e.g., the loss time of 1 s, the loading time of 400 ms, and the cloud temperature of 0.7 mK, are comparable to those in previously reported violet Yb MOTs, yet with a greatly reduced cost and complexity of the experiment.Comment: 5 pages, 3 figures, 1 table, Phys. Rev. A (to be published

    Cyclic AMP-specific phosphodiesterase, PDE8A1, is activated by protein kinase A-mediated phosphorylation

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    The cyclic AMP-specific phosphodiesterase PDE8 has been shown to play a pivotal role in important processes such as steroidogenesis, T cell adhesion, regulation of heart beat and chemotaxis. However, no information exists on how the activity of this enzyme is regulated. We show that under elevated cAMP conditions, PKA acts to phosphorylate PDE8A on serine 359 and this action serves to enhance the activity of the enzyme. This is the first indication that PDE8 activity can be modulated by a kinase, and we propose that this mechanism forms a feedback loop that results in the restoration of basal cAMP levels. (C) 2012 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserve

    Facile mechanochemical synthesis of non-stoichiometric silica-carbon composite for enhanced lithium storage properties

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    A large number of new electrode materials and novel structural designs are emerging for lithium-ion batteries, yet scalable synthesis and raw material costs still hinder the practical application of such materials. Here, we designed and fabricated a low-cost SiOx/C composite by a facile and scalable mechanofusion route with a ball-milling method. We selected aerosil and graphite precursor-needle coke, which are two widely used materials in industry, as a silicon source and carbon source, respectively. This SiOx/C composite shows a high reversible capacity (ca. 550 mAh g−1) at the 180th cycle and good rate performance. Our scalable synthesis route of electrode materials can stimulate the progress of other energy storage technologies for practical applications

    Landscape Design for Improved Thermal Environment: An Optimized Tree Arrangement Design for Climate-Responsive Outdoor Spaces in Residential Buildings Complexes

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    The heat reduction effect of trees has been investigated through numerical simulations; however, there are still challenges to applying the scientific results to the planning process due to the model's complexity and the computational resources required. This study investigates a rapid spatial evaluation method for heat stress potential, measured by mean radiant temperature (MRT), by decomposing radiation into sub-radiation using a multilayer MRT model. This method also enables the reproduction of optimized layouts considering the effect of tree arrangement in residential buildings. Multi-objectives were achieved through an evolutionary algorithm, resulting in more effective design layouts combining tree types and arrangements, all within a standard budget. By adopting this study's approach, landscape designers can create climate-responsive tree layouts with reduced heat exposure and generate customized planting designs tailored to their preferences

    An enhanced machine learning-based biometric authentication system using RR- Interval Framed Electrocardiograms

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    This paper is targeted in the area of biometric data enabled security by using machine learning for the digital health. The traditional authentication systems are vulnerable to the risks of forgetfulness, loss, and theft. Biometric authentication is has been improved and become the part of daily life. The Electrocardiogram (ECG) based authentication method has been introduced as a biometric security system suitable to check the identification for entering a building and this research provides for studying ECG-based biometric authentication techniques to reshape input data by slicing based on the RR-interval. The Overall Performance (OP) as a newly proposed performance measure is the combined performance metric of multiple authentication measures in this study. The performance of the proposed system using a confusion matrix has been evaluated and it has achieved up to 95% accuracy by compact data analysis. The Amang ECG (amgecg) toolbox in MATLAB is applied to the mean square error (MSE) based upper-range control limit (UCL) which directly affects three authentication performance metrics: the number of accepted samples, the accuracy and the OP. Based on this approach, it is found that the OP could be maximized by applying a UCL of 0.0028, which indicates 61 accepted samples within 70 samples and ensures that the proposed authentication system achieves 95% accuracy
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