Collective phase-like mode and the role of lattice distortions at TN ~TC in RMn2O5 (R= Pr, Sm, Gd, Tb, Bi)

We report on electronic collective excitations in RMn(2)O(5) (R =Pr, Sm, Gd, Tb) showing condensation starting at and below ~T(N) ~T(C)~ 40-50 K. Their origin is understood as partial delocalized e(g) electron orbitals in the Jahn-Teller distortion of the pyramid dimer with strong hybridized Mn(3+)-O bonds. Our local probes, Raman, infrared, and x-ray absorption, back the conclusion that there is no structural phase transition at T(N)~T(C). Ferroelectricity is magnetically assisted by electron localization triggering lattice polarizability by unscreening. We have also found phonon hardening as the rare earth is sequentially replaced. This is understood as a consequence of lanthanide contraction. It is suggested that partially f-electron screened rare earth nuclei might be introducing a perturbation to e(g) electrons prone to delocalize as the superexchange interaction takes place.     

Morphometric partitioning of the respiratory surface area and diffusion capacity of the gills and swim bladder in juvenile Amazonian air-breathing fish, Arapaima gigas

The gills and the respiratory swim bladders of juvenile specimens (mean body mass 100 g) of the basal teleost Arapaima gigas (Cuvier 1829) were evaluated using stereological methods in vertical sections. The surface areas, harmonic mean barrier thicknesses and morphometric diffusing capacities for oxygen and carbon dioxide were estimated. The average respiratory surface area of the swim bladder (2173 cm² kg^?1) exceeded that of the gills (780 cm² kg^?1) by a factor of 2.79. Due to the extremely thin air–blood barrier in the swim bladder (harmonic mean 0.22 μm) and the much thicker water–blood barrier of the gills (9.61 μm), the morphometric diffusing capacity for oxygen and carbon dioxide was 88 times greater in the swim bladder than in the gills. These data clearly indicate the importance of the swim bladder, even in juvenile A. gigas that still engage in aquatic respiration. Because of the much greater diffusion constant of CO₂ than O₂ in water, the gills also remain important for CO₂ release.     

Analytics and numerics of drug release tracking

The study of the dependence of fluxes, concentrations and response times, on the characteristic properties of drug delivery polymeric devices, plays an important role in the design of drug release platforms. The aim of this paper is to develop mathematical tools for an in-depth understanding of drug release tracking. The mathematical model presented takes into account the viscoelastic properties of the polymer and the state of the dispersed drug: free or chemically bound to the matrix. For nonlinear chemical bounds the process is described by a nonlinear integro-differential system and the drug release tracking is treated numerically. For linear chemical bounds closed formulas for the fluxes and response times are established in terms of the parameters that characterize the drug and the platform. These formulas provide a set of a priori estimations for the variables of the model. Numerical examples which show the effectiveness of the approach are included.     

Limit pricing under third-degree price discrimination

This paper shows how a multimarket incumbent can use low pre-entry prices for entry deterrence. We consider an incumbent who operates in two independent markets and has private information about his production cost. In one of the markets, there is a potential entrant offering a differentiated product. The most reasonable perfect Bayesian equilibrium is either the least-cost separating equilibrium or the pooling equilibrium where both types of incumbents set the low-cost monopoly prices. This equilibrium may involve a downward distortion in the pre-entry prices of both markets. Our model has interesting implications for antitrust regulation as well as for international trade policy. First, predatory tests based on a single market are inadequate for a multimarket incumbent. Second, a lower price in a foreign market is neither a necessary nor a sufficient condition for the existence of entry deterrence in a foreign market.     

Influence of low intensity laser therapy (AsGa) on the cicatrization process of mechanic tendon injury in wistar rats

The aim of this study was to compare the effect of the low level Laser therapy (AsGa) in the experimental tendon injury. Low level Laser therapy has been used in several studies to observe the regenerative quality and tecidual cicatrization. Forty Wistar rats (male) were divided into 4 groups: control group (C-group); injury group (L-group); treated group with Laser therapy 3 J/cm² (3J-group); and treated group with Laser therapy 6 J/cm² (6J-group). Groups L, 3J, and 6J were submitted to a mechanic Achilles tendon injury with a Kocher Forceps for 10 s. The animals were sacrificed after ten days of treatment. Histopathological evaluation using hematoxylin-eosin and Picro-Sirius staining showed a decreased (p < 0.05) of collagen in L-group (353.12 ± 9.85 ??m²/field) compared to C-group (215.13 ± 22.63 ??m²/field). Animals treated with Laser showed a significant increase in collagen fibers despite the applied dosage (3J-group: 375.89 ± 26.99 ??m²/field; 6J group: 400.34 ± 62.92 ??m²/field; p < 0.05). These data suggest that low-level Laser therapy was efficient for the treatment of mechanics Achilles tendon injury in Wistar rats.     

What does it take to launch self-confined jets from astrophysical accretion discs?

Well collimated jets are observed from young stellar objects (YSO), active galactic nuclei (AGN) and some galactic compacts objects (X-ray Binaries). These jets are powerful in the sense that they seem to carry a sizable fraction of the power released in the underlying accretion disc. The most complete and reliable jet models are actually disc winds, launched from the innermost disc regions: accretion and ejection are naturally interdependent, through the action of large scale magnetic fields anchored in the disc.In the last decade, disc winds have been quite successfully compared to observed YSO jets. Indeed, these jets are well monitored and provide several valuable diagnostics (plasma temperature, density and velocity stratification) that put stringent constraints on all available jet models. However, even if disc winds provide a satisfactory “first order” explanation for YSO jets, they cannot explain alone the whole phenomenology of these jets and some interaction with the central object must be taken into account.Disc wind models rely on the presence of a large scale vertical field close to equipartition. It will be shown that fulfilling such a condition is not an easy task. A complex interplay between advection and turbulent diffusion of the field is probably the cause of long term variability, as observed in X-ray binaries for instance. We also show, for the first time, that the outer parts in accretion discs could be highly magnetized. This may be the reason of ubiquitous massive, low velocity winds observed in YSOs, AGN and XrBs.     

Selective floating gate non‐volatile paper memory transistor

Here we report the performance of a selective floating gate (V_GS) n‐type non‐volatile memory paper field‐effect transistor. The paper dielectric exhibits a spontaneous polarization of about 1 mCm^–2 and GIZO and IZO amorphous oxides are used respectively as the channel and the gate layers. The drain and source regions are based in continuous conductive thin films that promote the integration of fibres coated with the active semiconductor. The floating memory transistor writes, reads and erases the stored information with retention times above 14500 h, and is selective (for V_GS > 5 ± 0.1 V). That is, to erase stored information a symmetric pulse to the one used to write must be utilized, allowing to store in the same space different information. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Two-dimensional temporal coherence coding for super resolved imaging

In this paper, we present an approach that can be used for transmission of 2D spatial information through space-limited systems capable of transmitting even only a single spatial pixel. The input 2D object is illuminated with temporally incoherent illumination. The axial coherence length is very short and it equals only a few microns. Attached to the input object spatial random phase mask generates different axial shift for every pixel of the input. The temporal delays of the encoding (axial shifts) of every pixel are longer than the coherence length of the illuminating source. Therefore no temporal correlation exists between the various pixels of the input. A lens combines all spatial pixels into one point at its focal plane. Although the various spatial pixels were mixed together, since the random mask provided axial delay which was larger than the coherence length of the light source, the orthogonality between the spatial content of every pixel is preserved. The decoding system includes a lens that is positioned at the output of the resolution reduction system and it converts the output light into a plane wave containing all the spatial information of the original image mixed together in all of its pixels. By interfering this plane wave with the same plane wave after passing through the same random spatial coding mask, the spatial information of every pixel of the input object is recovered.     

High-pressure phase equilibrium data for systems with carbon dioxide, α-humulene and trans-caryophyllene

The aim of this work is to report phase equilibrium data for the binary systems (CO₂ + α-humulene) and (CO₂ + trans-caryophyllene), and for the ternary system (CO₂ + α-humulene + trans-caryophyllene). Results from literature show that α-humulene and trans-caryophyllene are the main compounds responsible for the anti-inflammatory and anti-allergic characteristics attributed to the medicinal plant Cordia verbenacea D.C., hence giving importance to the phase behaviour investigation performed in this work. Phase equilibrium experiments were performed in a high-pressure, variable-volume view cell over the temperature range of T = (303 to 343) K and pressures up to 20 MPa. (Liquid + liquid) and (vapour + liquid + liquid) equilibrium were observed at T = 303 K, while (vapour + liquid) phase transitions were verified to occur from T = (313 to 343) K, for all systems studied. Thermodynamic modelling was performed using the Peng–Robinson equation of state and the classical quadratic mixing rules, with a satisfactory agreement between experimental and calculated values.