Controlling microstructure and film growth of relaxor-ferroelectric thin films for high break-down strength and energy-storage performance

The relaxor ferroelectric Pb_0.9La_0.1(Zr_0.52Ti_0.48)O₃ (PLZT) thin films were deposited using pulsed laser deposition, and their microstructures, break-down field strengths and energy storage performances were investigated as a function of the buffer layer and electrode. A large recoverable energy-storage density (U_reco) of 23.2 J/cm³ and high energy-storage efficiency (η) of 91.6% obtained in the epitaxial PLZT film grown on SrRuO₃/SrTiO₃/Si are much higher than those in the textured PLZT film (U_reco = 21.9 J/cm³, η = 87.8%) on SrRuO₃/Ca₂Nb₃O₁₀-nanosheet/Si and the polycrystalline PLZT film (U_reco = 17.6 J/cm³, η = 82.6%) on Pt/Ti/SiO₂/Si, under the same condition of 1500 kV/cm and 1 kHz, due to the slim polarization loop and significant antiferroelectric-like behavior. Owing to the high break-down strength (BDS) of 2500 kV/cm, a giant U_reco value of 40.2 J/cm³ was obtained for the epitaxial PLZT film, in which U_reco values of 28.4 J/cm³ (at BDS of 2000 kV/cm) and 20.2 J/cm³ (at BDS of 1700 kV/cm), respectively, were obtained in the textured and polycrystalline PLZT films. The excellent fatigue-free properties and high thermal stability were also observed in these films.     

Disruption of ergosterol biosynthesis,growth, and the morphological transition in <Emphasis Type="Italic">Candida albicans</Emphasis> by sterol methyltransferase inhibitors containing sulfur at C-25 in the sterol side chain

The sterol substrate analog 25-thialanosterol and its corresponding sulfonium salt were evaluated for their ability to serve as antifungal agents and to inhibit sterol methyltransferase (SMT) activity in Candida albicans. Both compounds inhibited cell proliferation, were fungistatic, interrupted the yeastlike-form to germ-tube-form transition, and resulted in the accumulation of zymosterol and related Δ²⁴-sterols concurrent with a decrease in ergosterol, as was expected for the specific inhibition of SMT activity. Feedback on sterol synthesis was evidenced by elevated levels of cellular sterols in treated vs. control cultures. However, neither farnesol nor squalene accumulated in significant amounts in treated cultures, suggesting that carbon flux is channeled from the isoprenoid pathway to the sterol pathway with minor interruption or redirection until blockage at the C-methylation step. Activity assays using solubilized C. albicans SMT confirmed the inhibitors impair SMT action. Kinetic analysis indicated that 25-thialanosterol inhibited SMT with the properties of a time-dependent mechanismbased inactivator K _i of 5 =gmM and apparent k _inact of 0.013 min⁻¹, whereas the corresponding sulfonium salt was a reversible-type transition state analog exhibiting a K _i of 20 nM. The results are interpreted to imply changes in ergosterol homeostasis as influenced by SMT activity can control growth and the morphological transition in C. albicans, possibly affecting disease development.     

D0C: A code to calculate scalar one-loop four-point integrals with complex masses

We present a new Fortran code to calculate the scalar one-loop four-point integral with complex internal masses, based on the method of 't Hooft and Veltman. The code is applicable when the external momenta fulfill a certain physical condition. In particular it holds if one of the external momenta or a sum of them is timelike or lightlike and therefore covers all physical processes at colliders. All the special cases related to massless external particles are treated separately. Some technical issues related to numerical evaluation and Landau singularities are discussed.     

Two channel digital watermarking for music based on exponential time-spread echo kernel

To robustly and imperceptibly embed copyright information as a watermark into music clips, a two channel digital watermarking system based on the least significant bit (LSB) method and echo hiding (EH) with a new exponential time-spread echo kernel (ETEK) is proposed. By spreading the echo so that it seems like natural room reverberation, as well as the use of two channels to separately watermark by the LSB method and the EH method which have complementary characteristics, the system provides satisfactory sound quality and exhibits both efficient retrieval capacity and robustness against attacks. Experiments show that the proposed system retrieves watermarks with 100% accuracy for all clips and is almost imperceptible. With a set of 42 attacks supplied by the StirMark Benchmark for Audio (SMBA), the proposed system has an average robustness of 0.98 where the ideal value is 1.00, and higher than any conventional methods. With these results, the proposed system is shown to be possible for the application to music distribution over the Internet.     

A comparison of historical land-use change patterns and recommendations for flood plain developments in three delta regions in Southeast Asia

Historical land-cover changes in three delta regions in Southeast Asia are assessed by using selected Landsat images from 1990 to 2005. Potential inundation areas of the delta regions for different return periods are estimated by using digital elevation model data and extreme-value distribution of annual maximum river discharges. The results indicate significant changes of natural land cover within the potential inundation areas due to agricultural exploitation and industrialization. Implications for flood-mitigation policies are discussed. There is a clear need for sustainable land-use management strategies in all three areas.     

Verschleißeigenschaften salzbadnitrocarburierter Oberflächen verschiedener Badvarianten

This paper explores the influence of two types of bath variants (Tenifer Classic and Tenifer Low Porosity) for the liquid nitrocarburising treatment technology on different types of steel (34CrAINi7, 42CrMoS4, 40CrMnNiMo, X8CrNiS18–9, EN-GJS-600 and especially 16MnCrS5, two 16MnCrS5-type steels and EN-GJS-400) with special focus on their tribological behaviour under dry conditions. A cylinder-on-plate test rig (Optimol SRV4) was employed to investigate the wear resistance of the treated materials. As one result it could be shown, that better wear resistivity under dry conditions not subsequently means harder and denser white layer.     

Comments on “Performances of a Fully Integrated All-Optical Pulse Reshaper Based on Cascaded Coupled Nonlinear Microring Resonators” [Sep 07 2417-2426]

In the above paper we did not accurately evaluate the Q-factors given in Table I. We give in the present table the corrected values. Captions of figures 11, 12, 13 and 15 must be changed using these new values: in the caption of Fig. 11 Q_in ^t 4.81, Q_out = 11.61 and Q_out ^t = 3.18; in the caption of Fig. 12 Q_out = 9.71 and Q_out ^t = 1.85; in the caption of Fig. 13 Q_out = 6.01 and Q_out ^t 4.64; in the caption of Fig. 15 Q_out = 5.86 and Q_out ^t = 2.11. In the text, the best Q-factor increase in the lossly case of 4.72 dB obtained at 10 Gbit/s.     

Mechanical behaviour of fired clay materials subjected to freeze–thaw cycles

The aim of this paper is to study the frost durability of fired clay materials. The behaviour of five fired clay materials with different physical and mechanical properties (porosity, permeability, mechanical strengths and elasticity modulus) subjected to freeze–thaw cycles is analysed. The strains of specimens and the evolution of the main properties with the number of cycles are assessed. The analysis shows that the pore distribution is not the only important parameter but that the tensile strength is also significant. A complete data bank is thus built up to study the effects of the physical and mechanical parameters on frost resistance and to determine how these parameters are affected by frost cycles. It will be possible to use these data to improve the modelling of coupled thermo-hydro-mechanical phenomena involved during the freezing and thawing process in porous media.