Ferromagnetic Fixed Point of the Kondo Model in a Luttinger Liquid

The Kondo effect in a Luttinger liquid is studied using the renormalization group method. By renormalizing the boson fields, scaling equations to the second order for an arbitrary Luttinger interaction are obtained. For the ferromagnetic Kondo coupling, a spin bound state(triplet) can be realized without invoking a nearest neighbor spin interaction in agreement with the recent Bethe ansatz calculation. The scaling theory in the presence of the scalar potential shows that there is no interplay between the magnetic and non-magnetic interaction. Also a study on the crossover behavior of the Kondo temperature between the exponential and the power law type is presented.Comment: 9 pages, 2 figures. Accepted for publication in J. Phys.: Condens. Matte

Multi-anyons in the magnetic field

We consider the external magnetic field effects on the two types of anyon with fractional statistical parameters $p/q$ with coprimes $p$ and $q$, one with fractional charge $e/q$ and flux $p \phi_0(=hc/e)$(type I), the other with fractional flux $p \phi_0/q$ and fundamental charge $e$(type II). These two-types of anyons show different behaviors in the presence of the external magnetic field. We also considered the geometry in which a two-dimensional plane contains an island of anyons with different statistical parameter in their equilibrium. The equilibrium inside an island is shown to be periodic with respect to the flux through the island. The period for the type I anyon equals to the integer multiple of the fundamental flux quantum. In the case of type II anyon the period is found to be the fractional multiple of the fundamental flux quantum.Comment: revtex, no figure

The CKM matrix from anti-SU(7) unification of GUT families

We estimate the CKM matrix elements in the recently proposed minimal model, anti-SU(7) GUT for the family unification, $[\,3\,]+2\,[\,2\,]+8\,[\,\bar{1}\,]$+\,(singlets). It is shown that the real angles of the right-handed unitary matrix diagonalizing the mass matrix can be determined to fit the Particle Data Group data. However, the phase in the right-handed unitary matrix is not constrained very much. We also includes an argument about allocating the Jarlskog phase in the CKM matrix. Phenomenologically, there are three classes of possible parametrizations, \delq=\alpha,\beta, or $\gamma$ of the unitarity triangle. For the choice of \delq=\alpha, the phase is close to a maximal one.Comment: 11 pages of LaTex file with 2 figure

Statistical Watermarking for Networked Control Systems

Watermarking can detect sensor attacks in control systems by injecting a private signal into the control, whereby attacks are identified by checking the statistics of the sensor measurements and private signal. However, past approaches assume full state measurements or a centralized controller, which is not found in networked LTI systems with subcontrollers. Since generally the entire system is neither controllable nor observable by a single subcontroller, communication of sensor measurements is required to ensure closed-loop stability. The possibility of attacking the communication channel has not been explicitly considered by previous watermarking schemes, and requires a new design. In this paper, we derive a statistical watermarking test that can detect both sensor and communication attacks. A unique (compared to the non-networked case) aspect of the implementing this test is the state-feedback controller must be designed so that the closed-loop system is controllable by each sub-controller, and we provide two approaches to design such a controller using Heymann's lemma and a multi-input generalization of Heymann's lemma. The usefulness of our approach is demonstrated with a simulation of detecting attacks in a platoon of autonomous vehicles. Our test allows each vehicle to independently detect attacks on both the communication channel between vehicles and on the sensor measurements

Universal Correction of Density Functional Theory to Include London Dispersion (up to Lr, Element 103)

Conventional density functional theory (DFT) fails to describe accurately the London dispersion essential for describing molecular interactions in soft matter (biological systems, polymers, nucleic acids) and molecular crystals. This has led to several methods in which atom-dependent potentials are added into the Kohn–Sham DFT energy. Some of these corrections were fitted to accurate quantum mechanical results, but it will be tedious to determine the appropriate parameters to describe all of the atoms of the periodic table. We propose an alternative approach in which a single parameter in the low-gradient (lg) functional form is combined with the rule-based UFF (universal force-field) nonbond parameters developed for the entire periodic table (up to Lr, Z = 103), named as a DFT-ulg method. We show that DFT-ulg method leads to a very accurate description of the properties for molecular complexes and molecular crystals, providing the means for predicting more accurate weak interactions across the periodic table

Prevalence and spatial concordance of visual field deterioration in fellow eyes of glaucoma patients.

PurposeTo examine the prevalence of visual field deterioration in contralateral eyes of patients with worsening open-angle glaucoma and to evaluate the spatial concordance of visual field deterioration between both eyes.MethodsOne hundred sixteen open-angle glaucoma patients who underwent 8 or more visual field examinations over ≥ 6 years of follow-up were included. The rates of the fast and slow components of visual field decay for each of 52 visual field test locations were calculated with point-wise exponential regression analysis. The spatial concordance of visual field deterioration in contralateral eyes was evaluated with a concordance ratio (calculated as the number of overlapping locations divided by the total number of deteriorating locations) and by comparing the rate of decay in corresponding modified glaucoma hemifield test clusters.ResultsThe average visual field mean deviation (± standard deviation [SD]) was -8.5 (± 6.4) dB and the mean (± SD) follow-up time was 9.0 (± 1.6) years. Sixty-three patients had mild damage, 23 had moderate damage, and 30 had severe damage. The mean concordance ratio (± SD) was 0.46 (± 0.32) for the mild group, 0.33 (± 0.27) for the moderate group, and 0.35 (± 0.21) for the severe group. Thirty-one patients (27%) had deterioration in concordant locations (p < 0.05). Visual field deterioration was greater in the superior hemifield than the inferior hemifield (p < 0.05) when evaluated with both the concordance ratio and modified glaucoma hemifield test cluster analysis methods.ConclusionsThere is only fair spatial concordance with regard to visual field deterioration between the both eyes of an individual. We conclude that testing algorithms taking advantage of inter-eye spatial concordance would not be particularly advantageous in the early detection of glaucomatous deterioration

750 GeV diphoton resonance and electric dipole moments

We examine the implication of the recently observed 750 GeV diphoton excess for the electric dipole moments of the neutron and electron. If the excess is due to a spin zero resonance which couples to photons and gluons through the loops of massive vector-like fermions, the resulting neutron electric dipole moment can be comparable to the present experimental bound if the CP-violating angle {\alpha} in the underlying new physics is of O(10^{-1}). An electron EDM comparable to the present bound can be achieved through a mixing between the 750 GeV resonance and the Standard Model Higgs boson, if the mixing angle itself for an approximately pseudoscalar resonance, or the mixing angle times the CP-violating angle {\alpha} for an approximately scalar resonance, is of O(10^{-3}). For the case that the 750 GeV resonance corresponds to a composite pseudo-Nambu-Goldstone boson formed by a QCD-like hypercolor dynamics confining at \Lambda_HC, the resulting neutron EDM can be estimated with \alpha ~ (750 GeV / \Lambda_HC)^2\theta_HC, where \theta_HC is the hypercolor vacuum angle.Comment: 21 pages, 5 figure

Design and Performance of Hybrid Control Rod For Passive IN-core Cooling System

Department of Nuclear EngineeringProtection of the public and the environment from undue radiation hazards is a definition of nuclear safety. Although there are various safety systems in nuclear power plants to achieve the nuclear safety, Fukushima-Daiichi accident showed the vulnerabilities of the installed safety systems. After the Fukushima accident, various passive safety systems and strategies are under development to cope with the postulated accidents. The majority of passive safety systems concentrated to inject emergency core coolant (ECC) or feedwater with the circuits comprise many pipelines and valves. In station blackout condition, the pressure of reactor vessel would be higher than the ECC injection pressure resulting in failure of ECC supply and eventually causing core damage. The reliability issues about the performance of passive safety systems have been discussed owing to their high uncertainties, low performance, and lack of experience in operation compared to active safety systems. In aspect of probabilistic safety, complex circuits which comprise many valves and pipelines have possibilities of single failure and common cause failure. Development of innovative passive safety system having differentiated working principle, significant performance, and low possibility of failure can enhance reactor safety providing solutions for the aforementioned problems. Based on these requirements, hybrid control rod which combines the functions of control rod and heat pipe was proposed for the development of passive in-core cooling system (PINCs). The control rods drop to the core using gravity and shutdown the reactor by neutron absorption. The thermosyphon heat pipe is a passive heat transfer device using phase change and convection of working fluid in a closed metal container having two different temperature interfaces (evaporator and condenser). The combination of thermosyphon and control rod, hybrid control rod can achieve reactor shutdown and decay heat removal simultaneously at accident conditions. Hybrid control rod was designed considering the aspects of neutronics (reactivity worth) and mechanical integrity. Most of the nuclear reactors operate at high temperature and high pressure environment with high power density. Thus, pressure control strategies of the hybrid control rod using non-condensable gas and expansion of the working fluid were established to achieve high decay heat removal capacity and operating conditions. The designed hybrid control rods were equipped on the experimental facility and their thermal performances were studied under various amount of working fluid, amount of non-condensable gas, and operating pressures of the test section. The experimental results showed relations between heat transfer characteristics and controlled parameters. Controlling operating condition of hybrid control rod in high pressure worked successfully, and the proportionality between maximum heat removal capacity and operating pressure of hybrid control rod design has been proven. Measured maximum heat transfer rate of single hybrid control rod was 6 kW at 20 bar. Simulations of multi-dimensional analysis for reactor safety (MARS) code were also performed to validate the experimental results and evaluate the prediction capability of the code on the hybrid control rod. The simulation results showed the limits of heat transfer models in the code analyzing the hybrid control rod in which the boiling and condensation heat transfer occurs simultaneously in a manner of countercurrent flow. The experimental results were compared with several models associated with boiling heat transfer, condensation heat transfer, and critical heat flux (CHF) of thermosyphon for the development or the selection of optimal models. The selected models could be implemented to system analysis codes in the purpose of deterministic safety assessment of PINCs against design basis accidents. Imura???s correlation, which was developed in two-phase natural convection condition and validated with experiments in wide range, was selected as boiling heat transfer model of pressurized hybrid control rod. The existing condensation models were based on Nusselt???s film condensation theory. Hence, the effect of non-condensable gas and perturbation between upward vapor flow and downward liquid film flow were not considered at the same time. The change of effective heat transfer length due to presence of non-condensable gas and effect of fluid inertia were considered for the derivation of new condensation model. The main thermal-hydraulic phenomenon which induces CHF of thermosyphon is flooding. The flooding-based CHF models for thermosyphon were derived with theories on instability of the liquid film or maximum liquid film flow rate in countercurrent flow condition. The limited prediction capabilities of the models were attributed to difference between hydraulic diameter and heated diameter as well as high operating pressure. Consequently, new model regarding the CHF of hybrid control rod was suggested to explain its unique characteristics. The hybrid control rod could be equipped on spent fuel dry storage casks for the extension of their thermal margins. The mock-up was designed to be scaled-down to 1/10 of metal dry storage cask developed by NAC. The effect of hybrid control rod on thermal margins of the cask was experimentally studied. The equipment of hybrid control rod with installation of heat sink lid reduced the temperature distributions inside the cask at equal power density condition. Application of hybrid control rod could extend the thermal margin up to 30 %. Feasibility of PINCs based on experimentally and analytically studied hybrid control rods were discussed according to commercial reactors. A number of nuclear facilities has been built to supply and manage energy. The nuclear fuels generate decay heat even in shutdown condition by fission products. Management of the decay heat is important to satisfy demand for nuclear safety. Therefore, new conceptual safety system is required to supplement the issues on existing safety systems. Passive in-core cooling system based on hybrid control rod is the effective way to be applied on extensive nuclear facilities containing nuclear fuels. Pressurized hybrid control rod could meet the operating conditions of application objects with significant decay heat removal capacity.ope

Multi-scale Simulation of Linear, Short-Chain Polyethylene Liquids under Flow Conditions

The rheological and structural properties of polymeric liquids cannot be condensed within a single numerical model. They should be described within hierarchical, multi-level numerical models in which each sub-model is responsible for different time and length scales; atomistic, mesoscopic, and continuum. In this study, the rheological and structural properties of linear, short-chain polyethylene liquids were investigated from the classical atomistic level to the mesoscopic and continuum levels of description. At the atomistic level of description, nonequilibrium molecular dynamics (NEMD) simulations of linear, short-chain polyethylene liquids spanning from C16H24 to C128H256 were performed to advance our knowledge of fundamental characteristic of chain molecules under shear and planar elongational flow. Furthermore, entanglement characteristics, such as the shortest primitive path length, and the network configurations, were investigated as functions of strain rate in both vastly different flow fields using the topological Z-code. At the mesoscopic level of description, Brownian dynamics (BD) simulations of a freely-jointed chain with equivalent contour length to C78H158 were carried out to compare single-chain dynamics in dense liquids (NEMD) and dilute solutions (BD) under shear flow. In addition, the macromolecular configurational diversity of individual chains in dense liquids and dilute solutions was explored using a brightness distribution method inspired by the rheo-optical investigation of DNA solutions. Based on these observations, a simple coarse-grained mesoscopic model for unentangled polymeric liquids and semi-dilute solutions was proposed and compared with NEMD simulation data and experiments of semi-dilute DNA solutions under shear flow in terms of the rheological and structural properties, such as viscosity, normal stress coefficients, conformation tensor, and so on. Moreover, this model was further coarse-grained to the continuum level through pre-averaging and compared with NEMD simulation data to examine the relationships between different levels of description on the rheological and structural properties of unentangled polymeric materials under shear flow