Femtosecond quantum fluid dynamics of helium atom under an intense laser field

A comprehensive, nonperturbative, time-dependent quantum mechanical (TDQM) approach is proposed for studying the dynamics of a helium atom under an intense, ultrashort (femtoseconds) laser pulse. The method combines quantum fluid dynamics (QFD) and density functional theory. It solves a single generalized nonlinear Schrödinger equation of motion (EOM), involving time and three space variables, which is obtained from two QFD equations, namely, a continuity equation and an Euler-type equation. A highly accurate finite difference scheme along with a stability analysis is presented for numerically solving the EOM. Starting from the ground-state Hartree-Fock density for He at t=0, the EOM yields the time-dependent (TD) electron density, effective potential surface, difference density, difference effective potential, ground-state probability, (r), magnetic susceptibility, polarizability, flux, etc. By a Fourier transformation of the TD dipole moment along the linearly polarized-field direction, the power and rate spectra for photoemission are calculated. Eleven mechanistic routes for photoemission are identified, which include high harmonic generation as well as many other spectral transitions involving ionized, singly excited, doubly excited (autoionizing), and continuum He states, based on the evolution of the system up to a particular time. Intimate connections between photoionization and photoemission are clearly observed through computer visualizations. Apart from being consistent with current experimental and theoretical results, the present results offer certain predictions on spectral transitions which are open to experimental verification

Time-dependent quantum fluid dynamics of the photoionization of the He atom under an intense laser field

A time-dependent (TD), nonperturbative quantum fluid density functional equation of motion, developed in our laboratory, is numerically solved for studying the photoionization dynamics of the He atom under an intense, ultrasharp, ultrashort laser pulse. The generalized nonlinear Schrodinger equation is obtained through a hydrodynamical continuity equation and an Euler-type equation of motion. It yields the electron density, effective potential surface, and other density-based quantities from start to finish. Starting from the ground-state Hartree-Fock density for He at t = 0, various singlet and triplet states of singly and doubly excited (autoionizing) He as well as several states of He+ have been identified in the time-evolved electron density, by a Fourier transformation of the time variable of the complex autocorrelation function. Computer visualizations of the td difference density and difference potential show distinctly nonlinear and extremely interesting geometrical features of the oscillating atom. Detailed mechanistic routes for multiphoton, sequential, and above-threshold ionization have been obtained, each route involving many states. The present, comprehensive method reveals the important physical features of the atom-laser interaction and the calculated results are consistent with current experimental and theoretical results. This emphasizes the validity of the hydrodynamical approach for studying td quantum mechanical phenomena

Stripped ion-helium atom collision dynamics within a time-dependent quantum fluid density functional theory

A nonperturbative, time-dependent (TD) quantum mechanical approach is described for studying the collision dynamics between the He atom and a fully stripped ion. The method combines quantum fluid dynamics and density functional theory to solve two coupled equations: one for the trajectory of the projectile nucleus and the other for the electronic charge distribution of the target atom. The computed TD and frequency-dependent properties provide detailed features of the collision process. Inelastic and ionization cross sections are also reported

How do Australian mental health services use easy read to make information accessible for people with intellectual disability?

Introduction: Access to health information is a right for all people. Easy read information is one strategy used to make information accessible for people with intellectual disability. This research explored how easy read is used and the ways accessible information can address access barriers, with a focus on Australian mental health services. Methods: Semi-structured interviews were conducted across four sites to explore how easy read was used. Participants (n = 49) were easy read users, health practitioners and staff from services providing mental health care in New South Wales, Australia. An integrated health literacy framework was used to analyse data. Results: Most mental health staff did not use easy read or other accessible information, and did not consistently offer people with intellectual disability opportunities to understand, appraise and apply health information. This investigation confirmed the limited availability of accessible information resources, including easy read, and the importance of relationships of support when accessing health information. Conclusion: People with intellectual disability did not routinely have access to mental health information. Substantial change is required to address this disparity. Implications: Agency policy and processes require change to support staff practices that uphold the right to information. Inclusive practices that incorporate using easy read in health contexts, including mental health, are needed to facilitate change

Lifting defects for nonstable K_0-theory of exchange rings and C*-algebras

The assignment (nonstable K_0-theory), that to a ring R associates the monoid V(R) of Murray-von Neumann equivalence classes of idempotent infinite matrices with only finitely nonzero entries over R, extends naturally to a functor. We prove the following lifting properties of that functor: (1) There is no functor F, from simplicial monoids with order-unit with normalized positive homomorphisms to exchange rings, such that VF is equivalent to the identity. (2) There is no functor F, from simplicial monoids with order-unit with normalized positive embeddings to C*-algebras of real rank 0 (resp., von Neumann regular rings), such that VF is equivalent to the identity. (3) There is a {0,1}^3-indexed commutative diagram D of simplicial monoids that can be lifted, with respect to the functor V, by exchange rings and by C*-algebras of real rank 1, but not by semiprimitive exchange rings, thus neither by regular rings nor by C*-algebras of real rank 0. By using categorical tools from an earlier paper (larders, lifters, CLL), we deduce that there exists a unital exchange ring of cardinality aleph three (resp., an aleph three-separable unital C*-algebra of real rank 1) R, with stable rank 1 and index of nilpotence 2, such that V(R) is the positive cone of a dimension group and V(R) is not isomorphic to V(B) for any ring B which is either a C*-algebra of real rank 0 or a regular ring.Comment: 34 pages. Algebras and Representation Theory, to appea

Efficient Equilibria in Polymatrix Coordination Games

We consider polymatrix coordination games with individual preferences where every player corresponds to a node in a graph who plays with each neighbor a separate bimatrix game with non-negative symmetric payoffs. In this paper, we study $\alpha$-approximate $k$-equilibria of these games, i.e., outcomes where no group of at most $k$ players can deviate such that each member increases his payoff by at least a factor $\alpha$. We prove that for $\alpha \ge 2$ these games have the finite coalitional improvement property (and thus $\alpha$-approximate $k$-equilibria exist), while for $\alpha < 2$ this property does not hold. Further, we derive an almost tight bound of $2\alpha(n-1)/(k-1)$ on the price of anarchy, where $n$ is the number of players; in particular, it scales from unbounded for pure Nash equilibria ($k = 1)$ to $2\alpha$ for strong equilibria ($k = n$). We also settle the complexity of several problems related to the verification and existence of these equilibria. Finally, we investigate natural means to reduce the inefficiency of Nash equilibria. Most promisingly, we show that by fixing the strategies of $k$ players the price of anarchy can be reduced to $n/k$ (and this bound is tight)

The munich LSTM-RNN approach to the MediaEval 2014 "Emotion in Music" Task

In this paper we describe TUM's approach for the MediaEval's \Emotion in Music" task. The goal of this task is to automatically estimate the emotions expressed by music (in terms of Arousal and Valence) in a time-continuous fashion. Our system consists of Long-Short Term Memory Recurrent Neural Networks (LSTM-RNN) for dynamic Arousal and Valence regression. We used two di erent sets of acoustic and psychoacoustic features that have been previously proven as e ective for emotion prediction in music and speech. The best model yielded an average Pearson's correlation coe-cient of 0.354 (Arousal) and 0.198 (Valence), and an average Root Mean Squared Error of 0.102 (Arousal) and 0.079 (Valence)

STABILITY INDICATING CHIRAL HPLC METHOD FOR THE ESTIMATION OF PIOGLITAZONE ENANTIOMERS IN PHARMACEUTICAL FORMULATION

Objective: A stability indicating chiral high performance liquid chromatographic (HPLC) method was developed and validated for the separated (S)and (R) pioglitazone in raw material and its determination in the presence of degradation products formed during forced degradation studies.Methods: In the present study, an isocratic normal phase-HPLC method was developed with stationary phase as ACI Cellu 1 (150 mm × 4.6 mm i.d.,5  μ)  column  and  n-hexane:  N-propyl  alcohol  (80:20,  V/V)  as  mobile  phase.  The  entire  study  was  performed  using  1.0  ml/minute  as  flow  rate  and the detection wavelength at  233 nm. The pioglitazone (R and S) was exposed to various stress condition such as hydrolytic (acid and base), neutral, oxidative, and photolytic. The stressed samples were analyzed by the proposed method.Result:  The  described  method  was  linear  over  the  range  of  5-15 µg/ml  for  R-pioglitazone  and  4-14 µg/ml  for  S-pioglitazone.  The  limit  of  detection and limit of quantification of S-pioglitazone and R-pioglitazone were found to be 1.4 μg/ml and 4.26 μg/ml, respectively. The recovery study of S and R-Pioglitazone from tablets formulation ranged from 97.14% to 100.04%, respectively.Conclusion: The developed method can be applied in the quality control of drug products.Keywords: Stability-indicating method, Validation, Chiral, Pioglitazone