Comment on "Clock Shift in High Field Magnetic Resonance of Atomic Hydrogen"

In this Comment, we reanalyze the experiments on the collision frequency shift of the b-c and a-d hyperfine transitions in three-dimensional atomic hydrogen in the presence of, respectively, a and b-state atoms. Accurate consideration of the symmetry of the spatial and spin part of the diatomic wavefunction yields the difference a_T-a_S=0.30(5) \AA between the triplet and singlet s-wave scattering lengths of hydrogen atoms. This corrects the factor-of two error of the commented work [Phys. Rev. Lett. 101, 263003 (2008)].Comment: 1 pag

Decay Properties Of The Dipole Isobaric Analog Resonances

A continuum-RPA-based approach is applied to describe the decay properties of isolated dipole isobaric analog resonances in nuclei having not-too-large neutron excess. Calculated for a few resonances in 90Zr the elastic E1-radiative width and partial proton widths for decay into one-hole states of 89Y are compared with available experimental data.Comment: 8 pages, 4 figures, prepared with RevTe

Hyperfine frequency shift in two-dimensional atomic hydrogen

We propose the explanation of a surprisingly small hyperfine frequency shift in the two-dimensional (2D) atomic hydrogen bound to the surface of superfluid helium below 0.1 K. Owing to the symmetry considerations, the microwave-induced triplet-singlet transitions of atomic pairs in the fully spin-polarized sample are forbidden. The apparent nonzero shift is associated with the density-dependent wall shift of the hyperfine constant and the pressure shift due to the presence of H atoms in the hyperfine state $a$ not involved in the observed $b\to c$ transition. The interaction of adsorbed atoms with one another effectively decreases the binding energy and, consequently, the wall shift by the amount proportional to their density. The pressure shift of the $b\to c$ resonance comes from the fact that the impurity $a$-state atoms interact differently with the initial $b$-state and final $c$-state atoms and is also linear in density. The net effect of the two contributions, both specific for 2D hydrogen, is comparable with the experimental observation. To our knowledge, this is the first mentioning of the density-dependent wall shift. We also show that the difference between the triplet and singlet scattering lengths of H atoms, $a_t-a_s=30(5)$ pm, is exactly twice smaller than the value reported by Ahokas {\it et al.}, Phys. Rev. Lett. {\bf101}, 263003 (2008).Comment: 4 pages, no figure

Synthetic cannabinoids induced psychotic episode as differential diagnostic challenge: clinical case

In order to highlight a problem of differential diagnostic of primal psychotic episode which induced by "smoking mixtures" intoxication, the case of a primary psychotic episode of schizophrenia due to the use of cannabinoids, which is primarily qualified as acute polymorphic psychotic disorder with symptoms of schizophrenia has been described. As a result, the issue of clinical differential diagnosis of the genesis of acute polymorphic psychotic disorder with symptoms of schizophrenia induced by synthetic cannabinoids was revealed

Variants and factors of catatonic syndrome pathomorphosis in the structure of endogenous catatonia

Urgency. Pathomorphosis of mental pathology leads to polymorphism or dissociation of its clinical manifestations, and, as a result, to difficulties in identification and differential diagnosis of individual psychopathological forms. Design. In order to establish the basic characteristics, variants and factors of the endogenic catatonia pathomorphism in schizophrenia patients, 144 individuals were examined. In the patients under examination the elements of endogenous catatonia were in the structure of various clinical forms of schizophrenia. Results. On the basis of a comparative analysis of the clinical and psychopathological characteristics of the catatonic syndrome in two ten - year periods pool of factors of endogenous catatonia pathomorphism, its structural and dynamic deviations were established. Conclusions. The main characteristics and tendencies of endogenous catatonia pathomorphism are determined. Four groups of catatonic syndrome pathomorphosis factors are identified and systematized: pharmacogenic, toxic, alternative, involutionary. Two vectors of pathomorphosis were systematized: functional (pharmacogenic and toxic groups) and morphological (alternative and involutionary groups)

Robust computer-aided synthesis and optimization of linear multivariable control systems with varying plant dynamics via AUTOCON

AUTOCON is an automated computer-aided design tool for the synthesis and optimization of linear multivariable control systems based upon user-defined control parameter optimization. Violations in stability and performance requirements are computed from constraints on Single Input/Single Output (SISO) open- and closed-loop transfer function frequency responses, and from constraints on the singular-value frequency responses of Multiple Input/Multiple Output (MIMO) transfer functions, for all critical plant variations. Optimum nonlinear programming algorithms are used in the search for local constrained solutions in which violations in stability and performance are caused either to vanish or be minimized for a proper selection of the control parameters. Classical control system stability and performance design can, in this way, be combined with modern multivariable robustness methods to offer general frequency response loop-shaping via a computer-aided design tool. Complete Nichols, Nyquist, Bode, singular-value Bode magnitude and transient response plots are produced, including user-defined boundary responses. AUTOCON is used to synthesize and optimize the lateral/directional flight control system for a typical high-performance aircraft

Impurity relaxation mechanism for dynamic magnetization reversal in a single domain grain

The interaction of coherent magnetization rotation with a system of two-level impurities is studied. Two different, but not contradictory mechanisms, the `slow-relaxing ion' and the `fast-relaxing ion' are utilized to derive a system of integro-differential equations for the magnetization. In the case that the impurity relaxation rate is much greater than the magnetization precession frequency, these equations can be written in the form of the Landau-Lifshitz equation with damping. Thus the damping parameter can be directly calculated from these microscopic impurity relaxation processes

On Uniqueness of Boundary Blow-up Solutions of a Class of Nonlinear Elliptic Equations

We study boundary blow-up solutions of semilinear elliptic equations $Lu=u_+^p$ with $p>1$, or $Lu=e^{au}$ with $a>0$, where $L$ is a second order elliptic operator with measurable coefficients. Several uniqueness theorems and an existence theorem are obtained.Comment: To appear in Comm. Partial Differential Equations; 10 page