The S0_0(0) structure in highly compressed hydrogen and the orientational transition

A calculation of the rotational S$_0$(0) frequencies in high pressure solid para-hydrogen is performed. Convergence of the perturbative series at high density is demonstrated by the calculation of second and third order terms. The results of the theory are compared with the available experimental data to derive the density behaviour of structural parameters. In particular, a strong increase of the value of the lattice constant ratio $c/a$ and of the internuclear distance is determined. Also a decrease of the anisotropic intermolecular potential is observed which is attributed to charge transfer effects. The structural parameters determined at the phase transition may be used to calculate quantum properties of the rotationally ordered phase.Comment: accepted Europhysics Letter

Nanostratification of optical excitation in self-interacting 1D arrays

The major assumption of the Lorentz-Lorenz theory about uniformity of local fields and atomic polarization in dense material does not hold in finite groups of atoms, as we reported earlier [A. E. Kaplan and S. N. Volkov, Phys. Rev. Lett., v. 101, 133902 (2008)]. The uniformity is broken at sub-wavelength scale, where the system may exhibit strong stratification of local field and dipole polarization, with the strata period being much shorter than the incident wavelength. In this paper, we further develop and advance that theory for the most fundamental case of one-dimensional arrays, and study nanoscale excitation of so called "locsitons" and their standing waves (strata) that result in size-related resonances and related large field enhancement in finite arrays of atoms. The locsitons may have a whole spectrum of spatial frequencies, ranging from long waves, to an extent reminiscent of ferromagnetic domains, -- to super-short waves, with neighboring atoms alternating their polarizations, which are reminiscent of antiferromagnetic spin patterns. Of great interest is the new kind of "hybrid" modes of excitation, greatly departing from any magnetic analogies. We also study differences between Ising-like near-neighbor approximation and the case where each atom interacts with all other atoms in the array. We find an infinite number of "exponential eigenmodes" in the lossless system in the latter case. At certain "magic" numbers of atoms in the array, the system may exhibit self-induced (but linear in the field) cancellation of resonant local-field suppression. We also studied nonlinear modes of locsitons and found optical bistability and hysteresis in an infinite array for the simplest modes.Comment: 39 pages, 5 figures; v2: Added the Conclusions section, corrected a typo in Eq. (5.3), corrected minor stylistic and grammatical imperfection

First-Principle Homogenization Theory for Periodic Metamaterials

We derive from first principles an accurate homogenized description of periodic metamaterials made of magnetodielectric inclusions, highlighting and overcoming relevant limitations of standard homogenization methods. We obtain closed-form expressions for the effective constitutive parameters, pointing out the relevance of inherent spatial dispersion effects, present even in the long-wavelength limit. Our results clarify the limitations of quasi-static homogenization models, restore the physical meaning of homogenized metamaterial parameters and outline the reasons behind magnetoelectric coupling effects that may arise also in the case of center-symmetric inclusions.Comment: 58 pages, 10 figures Phys. Rev. B, in press (2011

Nuclear Magnetic Relaxation in the Ferrimagnetic Chain Compound NiCu(C_7_H_6_N_2_O_6_)(H_2_O)_3_2H_2_O: Three-Magnon Scattering?

Recent proton spin-lattice relaxation-time (T_1_) measurements on the ferrimagnetic chain compound NiCu(C_7_H_6_N_2_O_6_)(H_2_O)_3_2H_2_O are explained by an elaborately modified spin-wave theory. We give a strong evidence of the major contribution to 1/T_1_ being made by the three-magnon scattering rather than the Raman one.Comment: J. Phys.: Condens. Matter 16, No. 49, 9023 (2004

Posttreatment Ischemic Lesion Evolution Is Associated With Reduced Favorable Functional Outcome in Patients With Stroke

BACKGROUND AND PURPOSE: Ischemic lesion volume can increase even 24 hours after onset of an acute ischemic stroke. In this study, we investigated the association of lesion evolution with functional outcome and the influence of successful recanalization on this association. METHODS: We included patients from the MR CLEAN trial (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) who received good quality noncontrast CT images 24 hours and 1 week after stroke onset. The ischemic lesion delineations included infarct, edema, and hemorrhagic transformation. Lesion evolution was defined as the difference between the volumes measured on the 1-week and 24-hour noncontrast CTs. The association of lesion evolution with functional outcome was evaluated using unadjusted and adjusted logistic regression. Adjustments were made for baseline, clinical, and imaging parameters that were associated P<0.10) in univariate analysis with favorable functional outcome, defined as modified Rankin Scale score of ≤2. Interaction analysis was performed to evaluate the influence of successful recanalization, defined as modified Arterial Occlusion Lesion score of 3 points, on this association. RESULTS: Of the 226 patients who were included, 69 (31%) patients achieved the favorable functional outcome. Median lesion evolution was 22 (interquartile range, 10–45) mL. Lesion evolution was significantly inversely correlated with favourable functional outcome: unadjusted odds ratio, 0.76 (95% CI, 0.66–0.86; per 10 mL of lesion evolution; P<0.01) and adjusted odds ratio: 0.85 (95% CI, 0.72–0.97; per 10 mL of lesion evolution; P=0.03). There was no significant interaction of successful recanalization on the association of lesion evolution and favorable functional outcome (odds ratio, 1.01 [95% CI, 0.77–1.36]; P=0.94). CONCLUSIONS: In our population, subacute ischemic lesion evolution is associated with unfavorable functional outcome. This study suggests that even 24 hours after onset of stroke, deterioration of the brain continues, which has a negative effect on functional outcome. This finding may warrant additional treatment in the subacute phase

Beheers- en ontwikkelingsplan 2004 MNP-modellen: kennismodel effecten landschap kwaliteit monitoring schaal belevingsGIS

Dit plan ontwikkeld door het Natuurplanbureau, geeft een visie op drie modellen voor de graadmeters landschap, beleving en recreatie. Het gaat om: KELK (kennismodel effecten landschapkwaliteit); monitoringsysteem schaalkenmerken; belevingsGIS. Met het huidige systeem kunnen de gevolgen van veranderingen in grondgebruik aangegeven worden voor: herkenbaarheid van de ontstaansgeschiedenis, de belevingswaarde en de (recreatieve) gebruikswaard