Double Universal Research Articles

Double universality of the transition in the supercritical state.

Universality aids consistent understanding of physical properties and states of matter where a theory predicts how a property of a phase (solid, liquid, and gas) changes with temperature or pressure. Here, we show that the matter above the critical point has a remarkable double universality. The first universality is the transition between the liquid-like and gas-like states seen in the crossover of the specific heat on the dynamical length with a fixed inversion point. The second universality is the operation of this effect in many supercritical fluids, including N2, CO2, Pb, H2O, and Ar. Despite different structure and chemical bonding, the transition has the same fixed inversion point deep in the supercritical state. This advances our understanding of the supercritical state previously considered to be a featureless area on the phase diagram and a theoretical guide for improved deployment of supercritical fluids in green and environmental applications.

The Double Universal Joint Wrist on a Manipulator: Inverse Position Kinematics and Singularities

The Double Universal Joint Wrist on a Manipulator: Inverse Position Kinematics and Singularities

La crisis del Estado-Nación en el malestar de Europa

En este trabajo se abordan algunos de los problemas a los que hoy día se enfrenta la democracia en Europa, especialmente aquellos relacionados con el uso del concepto Estado- nación. Es cierto que este concepto se usó a fin de fundamentar la emergencia de los Estados europeos modernos. Sin embargo, el mismo concepto ha permitido ahora que se adopte un camino diferente hasta el extremo de reclamar una Europa distinta, la Europa de las naciones, que trata de ocupar el lugar de la antigua Europa de los Estados. Ambas alternativas, tanto la de los tradicionales Estados-nación, como la nueva de las naciones que reclaman su propio Estado, poseen el mismo fundamento filosófico-político, el concepto de Estado-nación. En este texto se reflexiona sobre ese concepto con el fin de descubrir la razón de su ambigüedad. A fin de conseguirlo, habremos de entender el mecanismo de su funcionamiento, lo que nos permitirá subrayar que el concepto de Estado-nación se basa en una doble universalidad.

Nonadiabatic quantum phase transition in a trapped spinor condensate

We study the effect of an external harmonic trapping potential on an outcome of the non-adiabatic quantum phase transition from an antiferromagnetic to a phase-separated state in a spin-1 atomic condensate. Previously, we demonstrated that the dynamics of an untrapped system exhibits double universality with two different scaling laws appearing due to conservation of magnetization. We show that in the presence of a trap double universality persists. However, the corresponding scaling exponents are strongly modified by transfer of local magnetization across the system. The values of these exponents cannot be explained by the effect of causality alone, as in the spinless case. We derive the appropriate scaling laws based on a slow diffusive-drift relaxation process in the local density approximation.

“Meng? It Just Means Cute”: A Chinese Online Vernacular Term in Context

“Meng? It Just Means Cute”: A Chinese Online Vernacular Term in Context

Dynamics of the modified Kibble-Żurek mechanism in antiferromagnetic spin-1 condensates

We investigate the dynamics and outcome of a quantum phase transition from an antiferromagnetic to phase separated ground state in a spin-1 Bose-Einstein condensate of ultracold atoms. We explicitly demonstrate double universality in dynamics within experiments with various quench time. Furthermore, we show that spin domains created in the nonequilibrium transition constitute a set of mutually incoherent quasicondensates. The quasicondensates appear to be positioned in a semi-regular fashion, which is a result of the conservation of local magnetization during the post-selection dynamics.

Double universality of a quantum phase transition in spinor condensates: modification of the Kibble-Żurek mechanism by a conservation law.

We consider a phase transition from an antiferromagnetic to a phase separated ground state in a spin-1 Bose-Einstein condensate of ultracold atoms. We demonstrate the occurrence of two scaling laws, for the number of spin domain seeds just after the phase transition, and for the number of spin domains in the final, stable configuration. Only the first scaling can be explained by the standard Kibble-Żurek mechanism. We explain the occurrence of two scaling laws by a model including postselection of spin domains due to the conservation of condensate magnetization.

Development of anthropomorphic robot hand SKK robot hand I

In this paper, a three-fingered anthropomorphic robot hand, called SKK Robot Hand I, is presented. By employing a two-DOF joint mechanism, called Double Active Universal Joint (abbreviated as DAUJ from now on) as its metacarpal joint, the hand makes it possible to mimic humanlike motions. We begin with addressing the motivation of the design and mention how the anthropomorphic feature of a human is realized in the design of SKK Hand I. Also, the mechanism of the hand is explained in detail, and advantages in its modular design are discussed. The proposed hand is developed for use as a testbed for dextrous manipulation. It is expected to resolve the increasing demand for robotic applications in unstructured environments. We describe its hardware construction as well as the controller structure including the preliminary results of experiments.

Development of Anthropomorphic Robotic Joint

In this paper, we present a new two-dof anthropomorphic joint mechanism that enables to mimic the humanlike motion. The proposed mechanism, called Double Active Universal Joint(DAUJ), generates a two-dof swivel motion without rolling by the coupled motion of two independent motor. In addition, we perform basic experiments to confirm the effectiveness of the proposed mechanism and the results are reported.

Single and Double Universal Seesaw Mechanisms with Universal Strength for Yukawa Couplings

Single and double universal seesaw mechanisms and the hypothesis of universal strength for Yukawa couplings are applied to formulate a unified theory of fermion mass spectrum in a model based on an extended Pati-Salam symmetry. Five kinds of Higgs fields are postulated to mediate scalar interactions among electroweak doublets of light fermions and electroweak singlets of heavy exotic fermions with relative Yukawa coupling constants of exponential form. At the first-order seesaw approximation, quasi-democratic mass matrices with equal diagonal elements are derived for all charged fermion sectors and a diagonal mass matrix is obtained for the neutrino sector under an additional ansatz. Assuming the vacuum neutrino oscillation, the problems of solar and atmospheric neutrino anomalies are investigated.

Double universality of 1/ f noise percolation-like exponent in systems with exponentially wide spectrum of resistances

Theory and numerical simulations of /1 f noise in random networks in which bonds take resistance r ∼ exp(- λx), where x is a random variable and λ ⪢ are presented. For microscopic noise generating mechanism which obeys the form of { δr 2} ∼ r 2+ θ , it is shown that the overall noise intensity of the network is given by C e ∼ λ m exp(- λθx c ), where 1 − x c is the percolation threshold. In the range 0 ⩽ θ < 2 exponent m is “double universal”, i.e. it is independent of the lattice geometry and of microscopic noise generating mechanism. Numerical simulations give m ≌ 2.5.

1/f noise in percolation and percolationlike systems.

The behavior of 1/f noise effective intensity in two-phase percolation systems and percolationlike systems with an exponentially wide distribution of bond resistances is reviewed. Monte Carlo simulations on random resistor networks are performed. For a two-phase system the numerical values of noise critical exponents \ensuremath{\kappa}=1.54\ifmmode\pm\else\textpm\fi{}0.025, \ensuremath{\kappa}\ensuremath{'}=0.61\ifmmode\pm\else\textpm\fi{}0.02, w=6.31\ifmmode\pm\else\textpm\fi{}0.25, and w\ensuremath{'}=6.9\ifmmode\pm\else\textpm\fi{}0.25 are found in agreement with theoretical analysis performed with the help of a hierarchical model of a two-phase percolation system. For a system with an exponentially wide spectrum of bond resistances, i.e., a system in which bonds take on resistances r=${\mathit{r}}_{0}$ exp(-\ensuremath{\lambda}x), where \ensuremath{\lambda}\ensuremath{\gg}1 and x is a random variable, it is assumed that in the individual resistors the noise generating mechanism obeys the form {\ensuremath{\delta}${\mathit{r}}^{2}$}\ensuremath{\sim}${\mathit{r}}^{2+\mathrm{\ensuremath{\theta}}}$. In this case the effective noise intensity ${\mathit{C}}_{\mathit{e}}$\ensuremath{\equiv}S\ensuremath{\Omega}, where S is the relative power spectral density of system resistance fluctuations and \ensuremath{\Omega} is the system volume, is given by ${\mathit{C}}_{\mathit{e}}$\ensuremath{\sim}${\ensuremath{\lambda}}^{\mathit{m}}$ exp(-\ensuremath{\lambda}\ensuremath{\theta}${\mathit{x}}_{\mathit{c}}$), where 1-${\mathit{x}}_{\mathit{c}}$ is the percolation threshold. The exponent m is ``double universal,'' i.e., it is independent of lattice geometry and of the microscopic noise generating mechanism. Numerical simulations performed for \ensuremath{\theta}=1 and 0 give approximately m\ensuremath{\simeq}2.3 and confirm this ``double universality'' of the exponent m. The connections between 1/f noise effective intensity and effective susceptibility in a two-phase weakly nonlinear percolation system are also established. \textcopyright{} 1996 The American Physical Society.

Matter-Induced Neutrino Oscillation in Double Universal Seesaw Model

The Mikheyev-Smirnov-Wolfenstein effect is investigated in an extended gauge field theory in which the universal seesaw mechanism is applied singly to the charged fermion sectors to lower their masses below the electroweak energy scale and doubly to the neutral fermion sector to make neutrinos superlight. At the first seesaw approximation, neutrinos are proved to have a distinctive spectrum consisting of doubly degenerate states with smaller mass mS and a singlet state with larger mas mL. The lepton mixing matrix is determined definitely in terms of the masses of charged leptons and down quarks, with a very small vacuum mixing angle sin θ= 0.043 ±0.004. The Schrödinger-like equation describing the spatial evolution of stationary neutrino flux is solved for globally-rotated-flavor wave functions. Comparison of its nonadiabatic solution with experimental results leads to an estimation mL2 - mS2 = (6 ±2) ×10-6 eV2 for the squared mass difference and a capture rate prediction of 74 ±12 SNU for the SAGE gallium experiment.

Matter-Induced Neutrino Oscillation in Double Universal Seesaw Model

The Mikheyev-Smirnov-Wolfenstein effect is investigated in an extended gauge field theory in which the universal seesaw mechanism is applied singly to the charged fermion sectors to lower their masses below the electroweak energy scale and doubly to the neutral fermion sector to make neutrinos superlight. At the first seesaw approximation, neutrinos are proved to have a distinctive spectrum consisting of doubly degenerate states with smaller mass ms and a singlet state with larger mass m L

Imperatives, Logic, and Moral Obligation

It is claimed that 'Do x!“ means 'Then you will do x'. Answering a “Why?” question concerning the former may take either of two forms, viz., 'Because ——' or 'If you wish to ——'. The second answer completes the truncated hypothetical. “Ought” sentences are treated as a species of imperatives involving universality in the “if” clause ('If anyone wished to ——'). Moral “ought” sentences involve a double universality, viz., the one mentioned above and universality connecting the action with social harmony (e.g., “If everyone were to do x, then there would be social harmony').