Long Range

A theme that has come to the fore in advanced planning for long-range space exploration is the concept of "propellantless propulsion" or "field propulsion." One version of this concept involves the projected possibility that empty space itself (the quantum vacuum, or space-time metric) might be manipulated so as to provide energy/thrust for future space vehicles. Although such a proposal has a certain science-fiction quality about it, modern theory describes the vacuum as a polarizable medium that sustains energetic quantum fluctuations. Thus the possibility that matter/vacuum interactions might be engineered for space-flight applications is not a priori ruled out, although certain constraints need to be acknowledged. The structure and implications of such a far-reaching hypothesis are considered herein. Comment: Paper withdrawn. Author Ibison does not subscribe to some of the speculations in this document

For most of the last century, condensed matter physics has been dominated by band theory and Landau's symmetry breaking theory. In the last twenty years, however, there has been an emergence of a new paradigm associated with fractionalization, emergent gauge bosons and fermions, topological order, string-net condensation, and long range entanglements. These new physical concepts are so fundamental that they may even influence our understanding of the origin of light and electrons in the universe.

The long-range and molecular orders and dynamics in codispersions of egg sphingomyelin-cholesterol have been investigated by synchrotron x-ray diffraction and electron spin resonance using phosphatidylcholine spin-labeled at several positions on the sn-2 chain. Mixtures containing 0, 17, 33, 41, 50 mol% cholesterol exhibited a single phase by x-ray diffraction methods. The temperature dependence of the d-spacing between 20 and 50°C is attenuated with increasing proportions of cholesterol, becoming invariant for cholesterol contents of 41 and 50 mol% on completion of the liquid-ordered phase. Electron spin resonance revealed two sites for 17 and 33 mol% cholesterol. One site is highly ordered and the other is less ordered than the fluid phase of pure sphingomyelin as shown by the molecular and the intramolecular order parameters reflecting the segmental motions of the probe. The two-sites exchange rate indicates a mean lifetime of the sites of ;0.1 ms during which the lipid displacement is ;1 nm. The short lifetime of the sites probed by ESR and the single phase detected by x-ray diffraction support in this binary mixture, the building up of the Lo phase by a progressive accumulation of randomly distributed sphingomyelin-cholesterol condensed complexes rather than by diffusional exchange between extended domains.

Proposed ship-based long-range electromagnetic guns require input energies greater then 100 MJ, at peak powers in excess of 50 GW, and at average power in the tens of megawatts. This paper describes a conceptual pulsed-power system for driving these types of guns. A generic design was developed based on state-of-the-art power-supply, capacitor, and switching technologies. Results of modeling and parametric studies are presented, and key issues that impact system size and configuration are explored. An assessment is made of the feasibility of integrating this type of system into an electric-drive ship.

In this paper multivariate spontaneous EEG signals from three broad groups of human subjects--control, seizure, and mania--were studied with the aim of investigating the possible effect of these pathologies on the degree of phase synchronization between cortical areas. The degree of phase synchrony was measured by two recently developed measures which are more suitable than classical indices like correlation or coherence when dealing with nonlinear and non-stationary signals like the EEG. Signals were reduced to seven frequency bands (delta, theta, alpha-1, alpha-2, beta-1, beta-2 and gamma) which were statistically compared between the normal and the other two groups. It was found that the degree of long-range synchrony was significantly reduced for both pathological groups as compared with the control group. No clear differences were found in the degrees of short-range synchrony.

Abstract. Planetary exploration mission requirements are becoming more demanding. Due to the increasing cost, the missions that provide mobile platforms that can acquire data at multiple locations are becoming more attractive. Wheeled vehicles such as the Mars ...

The homogeneous precipitation kinetics of the ordered phases Al 3 Zr and Al 3 Sc in Al solid solutions has been simulated at the mesoscopic scale by the cluster dynamics method. The polyatomic clusters, embedded in the solid solution, have an L1 2 structure and exchange solute atoms via absorption and emission reactions controlled by interfacial and long range diffusion. The time evolution of the cluster distribution is determined numerically, solving a set of master differential equations coupled through monomer exchanges. Results are presented for different temperatures and solute supersaturations and are discussed in terms of the classical schemes of precipitation and of recent atomistic Monte-Carlo simulations.

A nonlinear statistical method for the inversion of ocean color spectra is used to determine three inherent optical properties (IOPs), the absorption coefficients for phytoplankton and dissolved and detrital materials, and the backscattering coefficient due to particulates. The inherent optical property inversion model assumes that (1) the relationship between remotesensing reflectance and backscattering and absorption is well known, (2) the optical coefficients for pure water are known, and (3) the spectral shapes of the specific absorption coefficients for phytoplankton and dissolved and detrital materials and the specific backscattering coefficient for particulates are known. This leaves the magnitudes for the three unknown coefficients to be determined. A sensitivity analysis is conducted to determine the best IOP model configuration for the Sargasso Sea using existing bio-optical models. The optical and biogeochemical measurements used were collected as part of the Bermuda Bio-Optics Project and the U.S. Joint Global Ocean Flux Study Bermuda Atlantic Time Series (BATS). The results demonstrate that the lOP ......... ' mouc• is most sensitive to-' ....... useu to mourn changes in me exponential decay constant .............. absorption by dissolved and detrital materials. The retrieved chlorophyll a estimates show excellent correspondence to chlorophyll a determinations (r 2 = 81%), similar to estimates from standard band ratio pigment algorithms, while providing two additional retrievals simultaneously. The temporal signal of retrieved estimates of absorption by colored dissolved and detrital materials is mirrored in ratios of Kd(410) to Kd(488), a qualitative indicator for nonalgal light attenuation coefficients. The backscatter coefficient for particles is nearly constant in time and shows no correspondence with the temporal signal observed for chlorophyll a concentrations. Last, the IOP model is evaluated using only those wavelengths which closely match the Sea Viewing Wide Field of View Sensor wave bands. This results in only a 1 to 6% decrease in hindcast skill with the BATS biogeochemical data set. This is encouraging for the long-range goal of applying the IOP model to data from upcoming ocean color satellite missions. the inversion of ocean color spectra to produce three relevant inherent optical properties (IOPs) for the analysis of biogeochemical variability: the absorption coefficient by phytoplankton, the absorption coefficient by dissolved and detrital materials, and the backscattering coefficient due to Copyright 1997 by the American Geophysical Union. Paper number 96JC03243. 0148-0227/97/96JC-03243509.00 particulates. Methods to invert ocean color observations, such as those employed here, have been extensively explored by Morel and Prieur [1977], Sugihara et al. [1985], Sathyendranath et al. [1989], Gordon et al. [1988], and Roeslet and Perry [1995]. The color of the sea will be related to those photons which are backscattered from within the water column and are not absorbed before entering the atmosphere. Hence changes in the total absorption coefficient, a(;L) (notation list is provided), and the backscattering coefficient, b b (;L), regulate the variations in ocean color spectra or remotely sensed reflectance [Rrs(•.)], where Rrs(•.) is defined as the ratio of upwelled radiance to downwelled irradiance (=Lu(•.)/Ed(•.)). Values of a(;L) an be effectively partitioned into absorption due to water, phytoplankton, and nonalgal materials [e.g.,

Robotic unmanned aerial vehicles have great potential as surveying and instrument deployment platforms in the exploration of planets and moons with an atmosphere. Among the various types of planetary aerovehicles proposed, lighter-than-atmosphere (LTA) systems are of particular interest because of their extended mission duration and long traverse capabilities. In this paper, we argue that the unique characteristics of robotic airships make them ideal candidates for exploration of planetary bodies with an atmosphere. Robotic airships extend the capabilities of balloons through their flight controllability, allowing (1) precise flight path execution for surveying purposes, (2) long-range as well as close-up ground observations, (3) station-keeping for long-term monitoring of high science value sites, (4) transportation and deployment of scientific instruments and in situ laboratory facilities across vast distances, and (5) opportunistic flight path replanning in response to the detection of relevant sensor signatures. Implementation of these capabilities requires achieving a high degree of vehicle autonomy across a broad spectrum of operational scenarios. The paper outlines some of the core autonomy technologies required to implement the capabilities listed above, drawing on work and results obtained in the context of AURORA (Autonomous Unmanned Remote Monitoring Robotic Airship), a research effort that focuses on the development of the technologies required for substantially autonomous robotic airships. We discuss airship modeling and control, autonomous navigation, and sensor-based flight control. We also outline an approach to airborne perception and monitoring which includes mission-specific target acquisition, discrimination and identification, and present experimental results obtained with AURORA.

A pair of cyanide-bridged iron-copper molecular assemblies relevant to cyanide-inhibited heme-copper oxidases has been studied by X-ray absorption spectroscopy at both Fe and Cu K-edges. These two complexes, [(py)(OEP)Fe-CN-Cu(Me 6 tren)] 2+ (2) and [(py)(OEP)Fe-CN-Cu(TIM)] 2+ (3), contain a unique four-body Fe-C-N-Cu bridge with an Fe-C-N angle of 179°. They, however, differ significantly in the Cu-N-C angle (174°i n 2 and 147°in 3). These two complexes provide the opportunity to study long-range multiple scattering (MS) interactions between the Fe and the Cu centers. We have calculated theoretical four-body MS signals for the bridge configuration and other four-body pathways in the structures, and performed least-squares fittings of the theoretical signals to the experimental data using the GNXAS programs. A strong long-range Fe‚‚‚Cu interaction (4.94 Å) has been observed from both the Fe and Cu K-edge data for 2. GNXAS analysis shows that this long-range interaction is attributed to the MS amplitude enhancement from the linear four-body Fe-C-N-Cu configuration. This interaction is not observable from the Fe and Cu K-edge data for 3 where the angle deviates significantly from linearity. An angle-dependence study of MS effects on the Cu-N-C angle shows that there is a large enhancement of MS intensity when the angle approaches linearity, and that this MS effect is negligible when the angle is below ∼160°. Essentially no Fe-Cu interaction is detectable for a configuration with such an angle. Comparisons with three-body MS effects found in Fe-O/O(H)-Cu bridged systems are made. The significance of the findings of this study to the structural definition of the binuclear center in the cyanide-inhibited heme-copper oxidases is discussed.

A long-term, multiarea, and multistage model for the supply/interconnections expansion planning of integrated electricity and natural gas (NG) is presented in this paper. The proposed Gas Electricity Planning (GEP) model considers the NG value chain, i.e., from the supply to end-consumers through NG pipelines and the electrical systems value chain, i.e., power generation and transmission, in an integrated way. The sources of NG can be represented by NG wells, liquefied natural gas (LNG) terminals and storages of NG and LNG. The electricity generation may be composed by hydro plants, wind farms, or thermal plants where the latter represent the link between the gas and the electricity chain. The proposed model is formulated as a mixed-integer linear optimization problem which minimizes the investment and operation costs to determine the optimal location, technologies, and installation times of any new facilities for power generation, power interconnections, and the complete natural gas chain value (supply/transmission/storage) as well as the optimal dispatch of existing and new facilities over a long range planning horizon. A didactic case study as well as the Brazilian integrated gas/electricity system are presented to illustrate the proposed framework.

This study concerned an experimental truffle bed of downy oaks infected by the ectomycorrhizal fungus Tuber melanosporum and planted in 1983. The presence of T. melanosporum creates rounded areas with little herbaceous cover, termed AbrulisB, where carpophores are found. Thê investigation was aimed at relating the occurrence and carpophore production of T. melanosporum to soil properties, i.e., organic matter, structure, aeration and fertility, expressed in terms of total organic C, aggregate size classes, DTPA-extractable Fe and Mn, and host plant height. Data were Ž . processed by multivariate geostatistical techniques. A linear model of coregionalization LMC Ž . Ž . Ž . including i a nugget effect, ii a short-range spherical structure with a range of 7 m and iii a long-range spherical structure with a range of 32 m, was fitted to the experimental direct and Ž . cross-variograms of the investigated properties. Factorial kriging analysis FKA was used to separate the sources of variation of the data according to the spatial scale at which they operate, and to summarize and map them in terms of spatial factors. An indicator approach was adopted to estimate and map the conditional probability of presence and fructification of T. melanosporum. The visual comparison between the spatial pattern of the long-range structure of the first regionalized factor with the probability map of finding brulis plus carpophore production revealed ) Corresponding author. A. Castrignano . 0016-7061r00r$ -see front matter q 2000 Elsevier Science B.V. All rights reserved.

A composite map of 177 locI has been constructed in two steps. The first combined pairwise logarithmof-odds scores on 127 loci Into a comprehensive genetic map. Then this map was projected onto the physical map through cytogenetic assignments, and the small amount of physical data was interpolated for an additional 50 loci each of which had been assigned to an interval of less than 10 megabases. The resulting composite map is on the physical scale with a resolution of 1.5 megabases. In the future these methods may be used to incorporate locations from linkage, contigs, radiation hybrids, restriction fragments, and somatic cell maps. Dense, reliable, and well-documented maps are essential for longrange sequencing and to local and clone disease genes.

A common joining method in microelectronics is thermosonic bonding of gold wires to aluminium pads deposited on the integrated circuit. In the interface between the wire and the pad a number of intermetallic compounds Al x Au y can develop, which significantly affect the mechanical properties and corrosion resistance of the bonds. Based on Onsager's extremal principle of irreversible thermodynamics, the present paper describes the evolution of the intermetallic phases. This macroscopic model contains several thermodynamic and kinetic parameters, some of which are not available from databases. As an alternative to often cumbersome experiments, density functional theory is applied to calculate the formation energies of the phases and of atomic vacancies, as well as the vacancy migration energies in AlAu 4. To derive tracer diffusion coefficients from the atomistic vacancy jump rates, one must take peculiarities of the AlAu 4 lattice into account: the vacancy migration energy between certain gold sites is found to be rather low, but these low-energy jumps are arranged in closed triangles and, therefore, do not provide paths for long-range diffusion of gold atoms. However, together with two other types of jumps with still moderate migration energies, a contiguous network of diffusion paths for gold becomes possible. Since the diffusion of aluminium in AlAu 4 requires the generation of high-energy anti-site defects (at least temporarily), aluminium is expected to move very slowly, but no final solution is provided.

We study the directional-growth patterns of the transparent nonfaceted alloy succinonitrile-(D)camphor (SCN-DC) at eutectic concentration in thin and bulk samples using real-time observation methods. We measure in situ the minimum-undercooling spacing l m and the small-spacing stability limit l c of the thin, quasi-lamellar patterns. We find l 2 m V % 10:2 mm 3 s À1 and l c % 0:65l m. This last result is contrary to the common conjecture that l c ¼ l m in lamellar patterns, but in agreement with previous experimental and numerical studies in the CBr 4-C 2 Cl 6 eutectic. In bulk samples, we observe the growth of rod-like patterns in real time. We show that these patterns do not usually achieve long-range hexagonal order after long solidification times, although their average spacing reaches a constant value, which is close to l m , after a relatively short transient.

An important aspect of particle trajectory modeling in the ocean is the assessment of the uncertainty in the final particle position. Monte Carlo particle trajectory simulations using surface currents derived from standard-range and long-range CODAR HF radar systems were performed using random-walk and random-flight models of the unresolved velocities. Velocity statistics for these models were derived from the covariance functions of differences between CODAR and drifter estimates of surface currents. Comparison of predicted trajectories and drifter tracks demonstrate that these predictions are superior to assuming the drifters stay at their initial position. Vertical shear between the effective depth of long-range CODAR measurements ($2.4 m) and that of drifters (0.65 m) causes the drifters to move more rapidly downwind than predicted. This bias is absent when standard-range CODAR currents (effective depth $0.5 m) are used, implying that drifter leeway is not the cause of the bias. Particle trajectories were computed using CODAR data and the random-flight model for 24-hour intervals using a Monte Carlo approach to determine the 95% confidence interval of position predictions. Between 80% and 90% of real drifters were located within the predicted confidence interval, in reasonable agreement with the expected 95% success rate. In contrast, predictions using the random-walk approach proved inconsistent with observations unless the diffusion coefficient was increased to approximately the random-flight value. The consistency of the random-flight uncertainty estimates and drifter data supports the use of our methodology for estimating model parameters from drifter-CODAR velocity differences.

We study the formation and growth of equilibrium clusters in a suspension of weakly-charged colloidal particles and small non-adsorbing polymers. The effective potential is characterised by a short-range attraction and a long-range repulsion. The size, shape and local structure of the clusters are studied using three-dimensional particle microscopy. We observe a rapid growth in the mean cluster size and the average number of nearest neighbours approaching the gel boundary.

Despite the recent research interest in integrating land use and transportation models inspired by federal legislation, no product had met the data, budget, and personnel constraints faced by the metropolitan planning organizations in Indiana. Consequently, the Indiana Department of Transportation sponsored a study to determine the feasibility of assembling a software package that would capture the relationships between land use and transportation that MPOs need to incorporate in their planning and analysis, while accounting for the current and expected status of Indiana MPO hardware and software capabilities. An Integrated Transportation Land Use Modeling System (ITLUMS) was developed by adapting standard land use models in the literature to the needs of Indiana MPOs. In addition, ITLUMS automates procedures that have been done manually and offers some new methods for key steps in the modeling process. ITLUMS was developed with the close participation of an MPO, whose data were used to calibrate, validate, and test the system. The results were satisfactory enough to justify proceeding to the implementation stage of the project.

The MutT enzyme (129 residues) catalyzes the hydrolysis of normal and mutagenic nucleoside triphosphates, such as 8-oxo-dGTP, by substitution at the rarely attacked P-P, to yield NMP and pyrophosphate. Previous heteronuclear NMR studies of MutT have shown the secondary structure to consist of a five-stranded mixed P-sheet connected by the loop I-a-helix I-loop I1 motif, by two tight tums, and by loop 111, and terminated by loop IV-a-helix I1 [Abeygunawardana et al. (1993) Biochemistry 32, 1307 1 -13080; Weber et al. (1 993) Biochemistry 32, 1308 1 -13087). Complete side-chain assignments of IH and I3C resonances have now been made by 3D C(C0)NH and HCCH-TOCSY experiments. A total of 1461 interproton proximities (1 1 per residue), obtained by 3D 15N-resolved NOESY-HSQC and 3D I3C-resolved NOESY-HSQC spectra, including 372 long-range NOES, as well as 65 dihedral angle

We report the structural and magnetic properties of the La1−xTbxMn1/2Sc1/2O3 series. LaMn1/2Sc1/2O3 shows a long range ferromagnetic ordering in agreement with a fully polarized Mn-sublattice. The substitution of La with Tb produces structural changes which affect the magnetic properties. This substitution leads to a contraction in the unit cell volume that mainly reduces the M–O–M bond angle (M = Mn,

Page 1. Advanced pixel design for infrared 3D LADAR imaging Fabrice Guellec, Michaël Tchagaspanian Eric de Borniol, Pierre Castelein, André Perez, Johan Rothman CEA Leti – MINATEC, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France ABSTRACT ...

A hybrid method, coupling a ray tracing method and a finite difference approach, is proposed for modelling T-wave propagation from an underwater source to an on-land seismic station. The long-range hydroacoustic wavefield, estimated in the SOFAR channel by the Maslov approach, shows many triplications of propagation with an increasing number of caustics as the range increases. Ray tracing approaches lead to a straightforward analysis of the SOFAR propagation: we find that the duration and the amplitude of the hydroacoustic T waves generated by a source close to the SOFAR axis may be respectively eight times longer and almost seven times higher than the duration and the amplitude of hydroacoustic T waves generated by a source close to the SOFAR limits. The finite difference modelling handles the complex hydroacoustic–seismi c T-wave conversion on atoll shores with an illustration of seismic T waves recorded during the Midplate experiment in 1989. Two different seismic stations, FGA on the Fangataufa Atoll and DIN on the Mururoa Atoll, both in French Polynesia, have recorded the seismic T waves due to an underwater chemical blast at a distance greater than 900 km. Synthetic seismograms computed by our proposed hybrid method are close enough to the real data for quantitative interpretation. We believe that the input model structure is accurate enough to allow such analysis of the seismic T waves. The numerical simulation shows that the seismic T waves recorded at both stations are mainly composed of P phases and Rayleigh phases. The simulation shows that the seismic T-wave duration is often linked to the source depth, although other factors (the continental slope or the distance between the top of the continental slope and the seismic station) may also affect the signal duration.

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Atomic short-range order is commonly observed in CuMn alloys via a diffuse (1 1 2 0) peak in neutron diffraction patterns. There has been speculation for many years on the existence and nature of any corresponding long-range order. A sample of Cu80Mn20 has been irradiated in a high fast-neutron flux to produce a large number of crystal defects at around room temperature and thus facilitate the ordering process. Measurements of the diffuse neutron scattering from this sample demonstrate that long-range order has been induced in the sample, as evidenced by at least five Bragg peaks. This order is not seen in a reference sample prepared in identical fashion except for the irradiation. The Cowley short-range order parameters for both samples are calculated and a candidate structure for the long-range order is proposed.

We nd that intervals between successive drops from a leaky faucet display scale-invariant, longrange anticorrelations characterized by the same exponents of heart beat-to-beat intervals of healthy subjects. This behavior is also con rmed by numerical simulations on lattice and it is faucetwidth-and ow-rate-independent. The histogram for the drop intervals is also well described by a L evy distribution with the same index for both histograms of healthy and diseased subjects. This additional result corroborates the evidence for similarities between leaky faucets and healthy hearts underlying dynamics.

In this article we discuss the realization of antenna gate structures for inductively coupled passive HF RFID systems. Antenna gates are currently used in several applications, from industrial tracking to access control: in these structures the identification process is realized with the use of more antennas disposed in a configuration that makes them similar to doors. Nowadays these structures can reach a maximum width of 1.50-1.60 meters due to the limitations deriving from the CEPT ERC Recommendation 70-03 annex 9 on electromagnetic emissions from electronic devices. Next to this, limitations also derive from the decrease of the electromagnetic field with the distance and from physical constrains due to the fact that the field strength is proportional to the dimensions of the antennas. The purpose of this article is to describe a possible optimum configuration of antennas allowing the detection of tags across a 2 meters wide gate reducing as much as possible its dimensions.

Having explored mechanical activation for synthesis and fabrication of Pb-based relaxor ferroelectrics, we observed several unique phenomena in association with mechanical activation of these electroceramic materials, including the unique nanocrystalline structure, phase transition, order Á/disorder transformation and activation-induced morphotropic behavior. In the study of sequential combination of Pb(Fe 1/2 Nb 1/2 )O 3 (PFN), nanocrystallite perovskite PFN phase is successfully derived from mechanical activation of both mixed oxides and Columbite precursor. However, the two nanocrystalline PFN phases are considerably different in phase stability. Mechanical activation can lead to morphotropic behavior in complex perosvkites, such as in Pb(Ni 0.5 W 0.5 )O 3 Á/ PbTiO 3 (PNW Á/PT), where an unique temperature-stable dielectric behavior is demonstrated over the wide temperature range of (/ 120 to 40 8C. Both short range disordering and long range disordering occur in Pb(Mg 1/3 Nb 2/3 )O 3 Á/Pb(Mg 1/2 W 1/2 )O 3 (PMN Á/ PMW) upon mechanical activation. A Monte-Carlo simulation algorithm, based on the competition between the thermal activation and the mechanical activation-triggered shear process, is established to model the order Á/disorder transformation in Pb-based relaxor ferroelectrics. #

Low gradient optics have been proposed for an upgrade of the LHC interaction region. Using lower gradient, larger aperture and longer NbTi quadrupoles with respect to the nominal layout, it is possible to achieve = 25cm with additional aperture margins and better dynamic aperture. The main drawbacks are an increase of the number of the long range interactions and limitations in the downstream matching section. Four layouts and optics, which span the parameter space and modularity for NbTi technology, are proposed and studied extensively in order identify and quantify the merits and challenges.

We present a nonlinear dynamical model of the human gait control system in a variety of gait regimes. The stride-interval time series in normal human gait is characterized by slightly multifractal fluctuations. The fractal nature of the fluctuations becomes more pronounced under both an increase and decrease in the average gait. Moreover, the long-range memory in these fluctuations is lost when the gait is keyed on a metronome. Human locomotion is controlled by a network of neurons capable of producing a correlated syncopated output. The central nervous system is coupled to the motocontrol system, and together they control the locomotion of the gait cycle itself. The metronomic gait is simulated by a forced nonlinear oscillator with a periodic external force associated with the conscious act of walking in a particular way.

Multilayered BaTi 1-x Sn x O 3 (BTS) ceramics with different Ti/Sn ratios were produced by pressing and sintering at 1420 o C for 2 hours. X-ray diffractometry, scanning electron microscopy and energy dispersive spectroscopy were used for structural, microstructural and elemental analysis, respectively. The dielectric and ferroelectric behavior of sintered samples was studied, too. It is found that in ingredient materials, with increasing Sn content, the tetragonality decreases; Curie temperature moves towards room temperature, while the maximum of the dielectric constant increases, and also, they becomes less hysteretic. It is noticed that multilayered BTS ceramics with different Ti/Sn contents have a broad transition temperature and show a relatively high dielectric constant in a wide temperature range. It is shown that dielectric properties of these materials may be modified by a combination of different BTS powders as well as layers number.

Structural models of martensitic interfaces are those where the habit plane (HP) is comprised of coherent terraces reticulated by arrays of interfacial defects. Such interfaces are shown explicitly to exhibit no long-range displacements and to move in a glissile manner by lateral motion of disconnections along the interface. We quantify predictions of HP and orientation relationship (OR) between the parent and product crystals for such models in terms of a reference lattice in an approach called a topological model (TM). These crystallographic quantities for the TM are compared with those of the phenomenological theory of martensite crystallography (PTMC). For the case of transformations resembling α to β in Ti, but where lattice invariant deformation is suppressed, the two models agree when the interplanar spacings of the terraces in the two crystals are the same. However, although the OR's according to the two approaches are very similar, the predicted HP's differ systematically when the terrace plane spacings are varied. The differences arise because the PTMC interfaces are unrelaxed configurations that are invariant planes of the geometrical shape transformation, whereas TM interfaces are physically invariant planes as a transformation progresses.

The present paper is aimed at providing a survey of investigations undertaken regarding the preparation and characterization of helical supramolecular architectures using a strategy based on two concepts: coordination chemistry and mesomorphic behavior. Metal-coordination procedures have been used to design and synthesize molecular units capable of organizing into helical superstructures. In order to ensure this capability, the molecular building blocks have been complemented with a pro-mesogenic character, most commonly columnar, so that this type of mesophase is used as a template to build up helical supramolecular architectures with long-range orientational order and long-range positional order. For example, metal-containing liquid crystals have been described that organize into helical columnar mesophases whose structure has been fully investigated. To date, molecular units that display this organizational behavior have been found to be very different in shape, and hence the formation of helical structures has a different origin in each case. In this paper, three molecular structures are discussed (i.e. 'disk-like' molecules, 'propeller-like' molecules and polycatenar elongated molecules) that have been shown to give rise to helical organizations. Models have been proposed for the three systems described and in the present overview these have been classified as azimuthal rotation of planar disk-like complexes, interdigitated stacking of octahedral complexes and staggered stacking of polycatenar elongated planar complexes, respectively. Throughout this paper, emphasis is placed on studies carried out in the mesophase that have allowed authors to propose the corresponding models. #

The electronic structure and size scaling of spectroscopic observables in conjugated polymers are investigated using time-dependent density functional theory. We show that local density approximations and gradientcorrected functionals do not have an effective attractive Coulomb interaction between photoexcited electronhole pairs to form bound states and therefore do not reproduce finite exciton sizes. Long-range nonlocal and nonadiabatic density functional corrections ͑such as hybrid mixing with an exact Hartree-Fock exchange͒ are necessary to capture correct delocalization of photoexcitations in one-dimensional polymeric chains.

Image and video quality in Long Range Observation Systems (LOROS) suffer from atmospheric turbulence that causes small neighbourhoods in image frames to chaotically move in different directions and substantially hampers visual analysis of such image and video sequences. The paper presents a real-time algorithm for perfecting turbulence degraded videos by means of stabilization and resolution enhancement. The latter is achieved by exploiting the turbulent motion. The algorithm involves generation of a "reference" frame and estimation, for each incoming video frame, of a local image displacement map with respect to the reference frame; segmentation of the displacement map into two classes: stationary and moving objects and resolution enhancement of stationary objects, while preserving real motion. Experiments with synthetic and real-life sequences have shown that the enhanced videos, generated in real time, exhibit substantially better resolution and complete stabilization for stationary objects while retaining real motion.

Abstract- Application of guided waves for rail inspection in railroad industry is considered in the paper. They are particularly sensitive to vertical defects and they are used at relatively low frequency so they are not significantly attenuated by weld material. Dispersion curves and mode shapes for guided waves in rails were calculated using finite element technique. For the experiments a mode that only propagates in the web of the rail at frequency less than 100 kHz was chosen. Novel transducers were designed which produce in-plane displacements. For damping of the transducers a specially designed backing material composite was used in order to reduce the ringing effect of the piezo element at low frequencies. Experiments were conducted using a single transducer and array of four transducers. Different materials were evaluated for dry-coupling of the transducers to the rail surface. The experimental prototype system enables the screening of 20 meters of rail from a single array p...

The Greater sage-grouse (Centrocercus urophasianus) occupies the sage brush habitats of Western North America. Large population declines in the last several decades have made it a candidate for possible listing under the Endangered Species Act. Listing was recently avoided in part because local working groups are developing long-range management plans in conjunction with federal and local agencies. The Foster Creek Conservation District, a working group in Douglas County, Washington, saw the potential for system dynamics to synthesize known sage-grouse dynamics and local land use patterns to support development of their Habitat Conservation Plan and subsequent land management decisions. This case study highlights the integration of science, local knowledge and social concerns into a participatory process that uses system dynamics as a forum for the exploration of the impacts of land management decisions upon the sage-grouse population and the landowners of Douglas County, Washington.

We report cloning and sequencing of gene ps1 encoding a versatile peroxidase combining catalytic properties of lignin peroxidase (LiP) and manganese peroxidase (MnP) isolated from lignocellulose cultures of the white-rot fungus Pleurotus eryngii. The gene contains 15 putative introns, and the deduced amino acid sequence consists of a 339-residue mature protein with a 31-residue signal peptide. Several putative response elements were identified in the promoter region. Amino acid residues involved in oxidation of Mn 2 and aromatic substrates by direct electron transfer to heme and long-range electron transfer from superficial residues as predicted by analogy with Phanerochaete chrysosporium MnP and LiP, respectively. A dendrogram is presented illustrating sequence relationships between 29 fungal peroxidases.

Seismologists, and more recently computational and condensed-matter physicists, have made extensive use of computer modeling to investigate the physics of earthquakes. Here, the authors describe a simple cellular automaton model that explores the possible relationship between Gutenberg-Richter scaling and critical phenomena.

The accurate long-range forecast of southwest rainfall can have manifold benefits for the country, from disaster mitigation and town planning to crop planning and power generation. In this paper, the rainfall has been modeled using artificial neural network (ANN) with different network configurations. Performance of these networks are compared with some results found in the literature. The networks have also been tested for the data outside the range of the trained data and compared with known results. The present network is found to be better in term of predictions than the previous results by others. Southwest monsoon rainfall over India for 6 years in advance has been predicted.

The alleged problems associated with self-control, hyperbolic discounting and other examples of seemingly irrational intertemporal choice are examined in the context of an evolution-based neurobiological model that emphasizes the role of the biological evolution of big brains and language and the cultural evolution of institutions. There is no utility function in the brain; it has no central-planner, in fact, the brain is a self-organized complex system, a decentralized spontaneous order. This spontaneous order is coordinated, much like an economy, by a distributed network that maintains and makes available the discounted net value of various options to decentralized and specialized areas in the brain when making decisions. Further, that decision making is embodied and embedded in the decision making environment. For humans, an important part of that environment is the social environment consisting of institutions and other components of culture. It was, in part, the evolution of this environment that made long-range planning possible. Additionally, it is very often the lack of embedded experience with the environment that leads to what seems to be irrational intertemporal choices. In fact, under close examination the evidence for consistent irrational intertemporal choice is weak.

We present for the first time, a fully integrated battery powered RFID integrated circuit (IC) for operation at ultrahigh frequency (UHF) and microwave bands. The battery powered RFID IC can also work as a passive RFID tag without a battery or when the battery has died (i.e., voltage has dropped below 1.3 V); this novel dual passive and battery operation allays one of the major drawbacks of currently available active tags, namely that the tag cannot be used once the battery has died. When powered by a battery, the current consumption is 700 nA at 1.5 V (400 nA if internal signals are not brought out on testpads). This ultra-low-power consumption permits the use of a very small capacity battery of 100 mA hr for lifetimes exceeding ten years; as a result a battery tag that is very close to a passive tag both in form factor and cost is made possible. The chip is built on a 1m digital CMOS process with dual poly layers, EEPROM and Schottky diodes. The RF threshold power at 2.45 GHz is -19 dBm which is the lowest ever reported threshold power for RFID tags and has a range exceeding 3.5 m under FCC unlicensed operation at the 2.4-GHz microwave band. The low threshold is achieved with architectural choices and low-power circuit design techniques. At 915 MHz, based on the experimentally measured tag impedance (92-j837) and the threshold spec of the tag (200 mV), the theoretical minimum range is 24 m. The tag initially is in a "low-power" mode to conserve power and when issued the appropriate command, it operates in "full-power" mode. The chip has on-chip voltage regulators, clock and data recovery circuits, EEPROM and a digital state machine that implements the ISO 18000-4 B protocol in the "full-power" mode. We provide detailed explanation of the clock recovery circuits and the implementation of the binary sort algorithm, which includes a pseudorandom number generator. Other than the antenna board and a battery, no external components are used.