Datasets:

nirantk

/

triplets-study-short

like 0

The role of dislocation scattering in n-type GaN films

The lateral transport in GaN films produced by electron cyclotron resonance plasma-assisted molecular beam epitaxy doped n type with Si to the levels of 1015–1020 cm−3 was investigated. The room temperature electron mobility versus carrier concentration was found to follow a family of bell-shaped curves consistent with a recently proposed model of scattering by charged dislocations. The mechanism of this scattering was investigated by studying the temperature dependence of the carrier concentration and electron mobility. It was found that in the low carrier concentration region (<1017 cm−3), the electron mobility is thermally activated with an activation energy half of that of carrier concentration. This is in agreement with the prediction of the dislocation model.

Abstract A layer of random defects in the simple cubic Ising model with nearest neighbor ferromagnetic interactions of strength J is considered. Using the real space renormalization group method we calculate defect free energy in the whole temperature range. Specifically, we analyze: the layer of diluted defects, the layer of spin-glass type defects, and the layer of mixed defects. The free energy is strongly dependent on the value of couplings between the defect and the bulk.

eng_Latn

Photoconductive decay in LCVD/PECVD low temperature grown GaN

Photoconductive decay in undoped GaN has been investigated at room temperature using an ArF excimer laser as illuminative source and a boxcar integrator for detection of decay signals. GaN films were grown by combined laser and microwave plasma enhanced chemical vapour deposition at 550°C. The respective room temperature electron concentration and Hall mobility of the films were measured to be in the range 1015–1016 cm−3 and up to 200 cm2/V s. Two time constants, 0.8 and 6 μs, are distinguishable in typical photoconductive decay curves and are associated with a dominant fast recombination and a weaker, slower process via an unidentified defect state respectively. Near-band photoluminescence dominates the emission spectrum with little contribution from the sub-bandgap process often found in the presence of high-density defects.

Using ultrafast optical-pump terahertz-probe spectroscopy, we study the THz dynamics and electronic cooling in few-layer epitaxial and CVD graphene; a microscopic theory of carrier-carrier and carrier-phonon interactions accounts quantitatively for the observed dynamics.

eng_Latn

The application of microelectrodes to the study of the methoxylation of furan

Abstract Steady state microelectrode techniques are used to investigate the bromide mediated, anodic oxidation of furan in methanol, a reaction of considerable synthetic interest. It is confirmed that the reaction occurs via a rate determining step between bromine and the furan. The dependence of the steady state limiting current for the Br − /Br 2 reaction on the radius of the microdisc electrode is analysed to obtain a rate constant of 68 dm 3 mol −1 s − for the reaction of bromine with furan.

We calculate the localization lengths for lattice fermions with random gap in two dimensions. This is done by means of the transfer matrix approach. Numerical results are analyzed for finite-size scaling and they exhibit a metal-insulator and a insulator-insulator transition. At these transitions we calculate the critical exponent of the localization length.

eng_Latn

DFT Theoretical Investigation of Ionization Potential and Electron Affinity of 2,6-Dithiopurine

All the molecular structures of thirty-three possible 2,6-dithiopurine tautomers have been optimized by density functional theory(DFT) method at B3LYP/6-311G(d,p) level.The paper also calculates the HOMO and the LUMO energy,the first ionization potential,electron affinity and energy level gap between HOMO and LUMO on all the tautomers,and Fermi levels in gas phase and aqueous phase.In addition,the paper analyzes and discusses the chemical activity of various isomers in the aqueous phase and gas phase,which will explore useful reference information for this molecular pharmacology activity and experimental study.

Abstract We report on n -channel tunneling field-effect transistors (TFET) with a tensile strained Si channel and a compressively strained Si 0.5 Ge 0.5 source. The device shows good performance with an average subthreshold swing S of 80 mV/dec over a drain current range of more than 3 orders of magnitude. We observed that the on-current increases exponentially with the back gate voltage. At a back gate voltage of 8 V, the on-current was enhanced by a factor of 1.6. The back gate also improves the on/off current ratio. Low temperature measurements show a slightly temperature dependent S , characteristic for a tunneling dominated device.

eng_Latn

Fine and Large Coulomb Diamonds in a Silicon Quantum Dot

We experimentally study the transport properties of silicon quantum dots (QDs) fabricated from a highly doped n-type silicon-on-insulator wafer. Low noise electrical measurements using a low temperature complementary metal-oxide-semiconductor (LTCMOS) amplifier are performed at 4.2 K in liquid helium. Two series of Coulomb peaks are observed: long-period oscillations and fine structures, and both of them show clear source drain voltage dependence. We also observe two series of Coulomb diamonds having different periodicity. The obtained experimental results are well reproduced by a master equation analysis using a model of double QDs coupled in parallel.

The dependence of the differential cross section ${\mathrm{d}\sigma}/{\mathrm{d}p_{\perp}}$ of inclusive heavy quark production in pp and $\bar{\mathrm{p}}$p collisions on the renormalization and factorization scales is investigated. The implications of our results for experiments at TEVATRON and LHC are discussed. In particular, it is shown that the NLO QCD predictions for $\bar{t}t$ production at the LHC based on the Principle of Minimal Sensitivity are by 30-50% higher than the standard ones.

eng_Latn

[The effect of hemocarbosorption and biohemosorption on oxygen metabolism and intoxication in patients with peritonitis in multiple organ failure].

An analysis of results of treatment of patients with diffuse peritonitis has shown that the syndrome of polyorganic insufficiency is found in 24.2% of cases. A system of score screening assessment of severity of the course of polyorganic insufficiency syndrome has been developed. The dynamics of indicators of intoxication and oxygen metabolism was used for comparison of efficiency of hemosorption and biohemosorption. Conclusions are made that hemocarbosorption is preferable at the first phase of the syndrome of polyorganic insufficiency while biohemosorption--at the second phase of polyorganic insufficiency.

Abstract We theoretically study the optical absorption in a quantum well with the semi-parabolic potential plus the semi-inverse squared potential (SPSIS) in the presence of a static magnetic field in which both one- and two-photon absorption processes have been taken into account. The expression of the magneto-optical absorption coefficient (MOAC) is expressed by the second-order golden rule approximation including the electron–LO phonon interaction. We also use the profile method to obtain the full width at half maximum (FWHM) of the absorption peaks. Our numerical results show that either MOAC or FWHM strongly depends on the confinement frequency, temperature, and magnetic field but their dependence on the parameter β is very weak. The temperature dependence of FWHM is consistent with the previous theoretical and experimental works.

eng_Latn

Effect of nonequilibrium phonons on superconducting states with two coexisting energy gaps

It is shown that under the influence of tunnel currents, superconductors may exhibit a ''first order transition'' to a state with two coexisting energy gaps. An energy and number conserving approximation for the collision operator is used to explicitly take into account in the theory the effect of nonequilibrium phonons. Quantitative predictions for experiments are presented.

We have developed a new framework of antisymmetrized molecular dynamics (AMD), to adequately treat the I=0 KN interaction, which is essential to study kaonic nuclei. The improved points are 1) pK{sup -}/nK{sup 0} mixing and 2) total spin and isospin projections. These improvements enable us to investigate various kaonic nuclei (ppnK{sup -}, pppK{sup -}, pppnK{sup -}, {sup 6}BeK{sup -}, {sup 9}BK{sup -}, and {sup 11}CK{sup -}) systematically. We have found that they are deeply bound and extremely dense with a variety of shapes.

eng_Latn

Multiple frequencies in quantum oscillations from underdoped YBa_2Cu_3O_6.5

High-precision measurements of the de Haas-van Alphen effect in the underdoped high-temperature superconductor \Y reveal three distinct frequencies in the quantum oscillations spectra. Analysis based on the standard Lifshitz-Kosevich theory reveal two satellite frequencies at F$_2$ = 450 T and F$_3$ = 630 T, on either side of a dominant frequency at F$_1$ = 540 T. Apart from a second harmonic of F$_1$, no other frequency is detected. We discuss the possibility that the satellite frequencies arise from bilayer splitting and warping of a single quasi-2D Fermi surface with c-axis dispersion, which indicates that c-axis coherence is restored at low temperature.

Through the study of the high-speed signal PCB(Printed Circuit Board)layout in the structure of the signal trace,for needs of smooth and controllable in PCB layout of high-speed digital server motherboard system,this paper proposes a three degree quasi-uniform B-spline dynamical fitting method.By reading overlap shape points in batches,property of high-speed signal traces with whole three degree quasi-uniform B-spline is realized.Through circuit debugging simulation,this dynamic fitting algorithm reduces high-speed signal attenuation effectively.

eng_Latn

Sinusoidally Modulated Silicon Leaky Wave Antenna for sub-THz Applications

A new sub-THz leaky wave antenna based on grounded silicon substrate for chip to chip communication applications is presented. The proposed leaky wave antenna is based on sinusoidally modulated surface reactance. This surface reactance is implemented by using varying width strips on the top of a grounded silicon substrate. Two approaches for developing these strips are studied. These two approaches are based on either highly doped silicon strips or gold strips. Both the doped silicon and the gold are presented by using their corresponding Drude models at the proposed operating frequency. Comparisons between the properties of these two approaches are presented to show the applicability of each one.

We present a comprehensive study of the frequency shifts associated with the lattice potential in a Sr lattice clock by comparing two such clocks with a frequency stability reaching 5x10{sup -17} after a 1 h integration time. We put the first experimental upper bound on the multipolar M1 and E2 interactions, significantly smaller than the recently predicted theoretical upper limit, and give a 30-fold improved upper limit on the effect of hyperpolarizability. Finally, we report on the first observation of the vector and tensor shifts in a Sr lattice clock. Combining these measurements, we show that all known lattice related perturbations will not affect the clock accuracy down to the 10{sup -17} level, even for lattices as deep as 150 recoil energies.

eng_Latn

1 Fundamental Problems for Universal Quantum Computers

Several fundamental problems and restrictions for universal quantum computers are pointed out. Firstly, it is shown that the halting of universal quantum computers is incompatible with the constraint of unitarity of the quantum dynamics. Secondly, the consequences of the second law of thermodynamics and the existence of time constants associated with the generation of initial states of quantum systems are shown to impose severe limits on the capabilities of quantum computers.

Using ultrafast optical-pump terahertz-probe spectroscopy, we study the THz dynamics and electronic cooling in few-layer epitaxial and CVD graphene; a microscopic theory of carrier-carrier and carrier-phonon interactions accounts quantitatively for the observed dynamics.

eng_Latn

Tensor random fields in conductivity and classical or microcontinuum theories

We study the basic properties of tensor random fields (TRFs) of the wide-sense homogeneous and isotropic kind with generally anisotropic realizations. Working within the constraints of small strains, attention is given to antiplane elasticity, thermal conductivity, classical elasticity and micropolar elasticity, all in quasi-static settings albeit without making any specific statements about the Fourier and Hooke laws. The field equations (such as linear and angular momentum balances and strain–displacement relations) lead to consequences for the respective dependent fields involved. In effect, these consequences are restrictions on the admissible forms of the correlation functions describing the TRFs.

Abstract In extension of an earlier note 1) we present some observations of different electric and magnetic switching phenomena in thin polycrystalline EuS film junctions. A possible explanation for qualitatively different nonllinearities of the current transport behavior in spite of very similar preparation conditions of the samples, is a narrow-band energetic structure with the Fermi level lying within such a band or between.

eng_Latn

Effects of Boundary Conditions and Source Dimensions on the Effective Thermal Conductivity of a Printed Circuit Board

The heat conduction equation and its boundary conditions were used to show that the planar and normal thermal conductivities of an orthotropic model of a printed circuit board were functions of source to board size ratio, top and bottom side boundary conditions, and thickness and thermal conductivity of each layer. Numerical solutions of the heat conduction equation were used to quantify the dependence on source to board size ratio and top and bottom boundary conditions. It was shown that the thermal conductivities were stronger functions of the source to board size ratio for smaller values of this ratio. This dependence was more pronounced for boards with stronger convection heat transfer on their top side, and for boards with thicker component side copper layer. The thermal conductivities were less sensitive to the variation of the convection heat transfer on the bottom side of the board.Copyright © 2003 by ASME

This paper describes a novel technique for studying structure-transport correlations in nanoscale multilayer thin films. Here, local current-voltage characteristics from simplified magnetic tunnel junctions are measured in situ on cross-sectional transmission electron microscopy (TEM) samples and correlated directly with TEM images of the microstructure at the tunneling site. It is found that local variations in barrier properties can be detected by a point probe method, and that the tunneling barrier height and width can be extracted.

eng_Latn

Excitation localization effects in nanoscale molecular clusters (J-aggregates)

An analysis of experimental data from low-temperature selective spectroscopy and single J-aggregate spectroscopy reveals a hierarchy of exciton states within the confines of the absorption band of J-aggregates which are formed by relaxation of an excited state. For J-aggregates, which are characterized by substantial static disorder, strongly localized excitons are found in the long-wavelength edge of the absorption band; they have a discrete energy spectrum and jump mobility, and are not subject to strong relaxation. Delocalized (spatially extended) excitons are excited within the absorption band of the J-aggregates, except at its long-wavelength edge. They are characterized by coherent exciton transport and are the source of self-localized excitons.

An instruction-level simulator for IBM 3090 with VF (vector facility) has been developed for studying the performance of vector processors and their memory hierarchies. Results of a study of the locality of several large scientific applications are presented. The cache miss ratios of vectorized applications are found to be almost equal to those of their original scalar executions. Moreover, both the spatial and temporal locality of these applications (in scalar and vector executions) are strong enough to show a sufficiently high hit ratio on conventional cache structures.<<ETX>>

eng_Latn

Approximate separability for the hydrogen atom in a uniform magnetic field

Starting from the O(4) supersymmetry of the field-free hydrogen atom, the authors study the spectrum of the H atom in a uniform magnetic field by exact numerical calculations in a complete basis. They define a label K that is approximately conserved and hence leads to very small anticrossings in a region reaching well into the n-mixing regime.

Abstract This paper presents a theoretical model for the behavior of solid solutions of group III and V impurities in silicon. The impurities are considered as weak electrolytes dissolved in an ionizing medium. The Fermi level, the activity coefficient and the dissociation equilibrium constants for the dopants are calculated, using Fermi-Dirac statistics, as functions of temperature and doping level. The solid solutions obey Henry's law at very low concentrations and exhibit positive deviations as the concentration is increased. Ionization of impurities or dopants as a function of their concentrations are discussed.

eng_Latn

AlGaN Channel High Electron Mobility Transistors with Ultra-Low Drain-Induced-Barrier-Lowering Coefficient

The conventional AlGaN/GaN high electron mobility transistor (HEMT), the AlGaN/GaN/AlGaN HEMT, and the AlxGa1−xN/AlyGa1−yN HEMT are fabricated on sapphire substrates to study the drain-induced barrier-lowering (DIBL) effect. It is found that the AlxGa1−xN/AlyGa1−yN HEMT with AlGaN channel has the lowest DIBL coefficient of 6.7 mV/V compared with the other two HEMTs. This is attributed to the best two-dimensional electron gas confinement of the AlxGa1−xN/AlyGa1−yN structure. This opinion is further confirmed by the conduction band diagrams and electron distribution calculated from the one-dimensional Poisson—Schrodinger equation.

Let W be a UHF algebra and sQ(D) the disk algebra. If W = [U,ll >1 I ]Jand a is a product-type automorphism of W which leaves each 21,, invariant, then a defines an embedding t1 2>(D) n+ 1 D The inductive limit of this system is a Banach algebra whose maximal ideal space is closely related to that of the disk algebra if the Connes spectrum F(a) is finite.

eng_Latn

Inhibition of Alzheimer's amyloid-β peptide aggregation and its disruption by a conformationally restricted α/β hybrid peptide

Insertion of an anthranilic acid in an amyloidogenic peptide sequence generates a novel conformationally restricted α/β-hybrid peptide that inhibits amyloid formation of Aβ(1–40) and disrupts preformed fibrillar aggregates in vitro. Such β-sheet breaker hybrid peptides (BSBHps) may be useful for designing novel physiologically important compounds relevant to diverse amyloidoses and for studying the process of aggregation.

We investigate the quantum anomalous Hall effect in a mixture of ultra-cold neutral bosons and fermions held on a hexagonal optical lattice. In the strong atom-atom interaction limit, composite fermions composed of one fermion with bosons or bosonic holes in the mixture are formed. Such composite fermions have already been generated successfully in experiment [Nat. Phys. {\bf 7}, 642 (2011)]. Here we predict that this kind of composite fermions may provide a realization of the quantum anomalous Hall effect by tuning the atom-atom interaction or the filling of the bosons in the mixture. We also discuss the corresponding experimental signatures of the quantum anomalous Hall effect in the Bose-Fermi mixture on hexagonal optical lattice.

eng_Latn

A Note on Biquaternionic MIT Bag Model

The term ”bag model” unifies several attempts to construct a mathematical description of the phenomenon of quark confinement. Such models are often used for estimating different characteristics of a hadron. The aim of this note is to add one more characterization to the list of known characterizations of Dirac equation (see, e.g., [8], [10]). In the article, we study the Dirichlet type boundary value problems and MIT bag model in three-dimensional piece-wise Liapunov domains. Mathematical Subject Classification: Primary 81V05, 78A25; Secondary 30G35

We present an electronic structure calculation of the valence band for some II--VI binary/ternary alloy interfaces. We use the empirical tight-binding method and the surface Green's function matching method. For the ternary alloys we use our previously set Hamiltonians they describe well the band gap change with composition obtained experimentally. At the interface domain, we find three non-dispersive and two interface states besides the known bulk bands. The non-dispersive states are reminiscent of the ones already obtained experimentally as well as theoretically, in (001)-oriented surfaces. We make use of the available theoretical calculations for the (001)-oriented surfaces of the binary compounds and for the binary/binary interfaces to compare our new results with.

kor_Hang

A Relation between the Correlation Dimensions of Multifractal Wavefunctions and Spectral Measures in Integer Quantum Hall Systems

We study the time evolution of wavepackets of non-interacting electrons in a two-dimensional disordered system in strong magnetic field. For wavepackets built from states near the metal-insulator transition in the center of the lowest Landau band we find that the return probability to the origin $p(t)$ decays algebraically, $p(t) \sim t^{-D_2/2}$, with a non-conventional exponent $D_2/2$. $D_2$ is the generalized dimension describing the scaling of the second moment of the wavefunction. We show that the corresponding spectral measure is multifractal and that the exponent $D_2/2$ equals the generalized dimension $\widetilde{D}_2$ of the spectral measure.

We model cross-market Bitcoin prices as long-memory processes and study dynamic interdependence in a fractionally cointegrated VAR framework. We find long-memory in both the individual markets and the system of markets depicting non-homogeneous informational inefficiency. Moreover, Bitcoin markets are found to be fractionally cointegrated, where uncertainty negatively impacts this type of cointegration relationship.

eng_Latn

Energy-level pinning and the 0.7 spin state in one dimension: GaAs quantum wires studied using finite-bias spectroscopy

We study the effects of electron-electron interactions on the energy levels of GaAs quantum wires (QWs) using finite-bias spectroscopy. We probe the energy spectrum at zero magnetic field, and at crossings of opposite-spin-levels in high in-plane magnetic field B. Our results constitute direct evidence that spin-up (higher energy) levels pin to the chemical potential as they populate. We also show that spin-up and spin-down levels abruptly rearrange at the crossing in a manner resembling the magnetic phase transitions predicted to occur at crossings of Landau levels. This rearranging and pinning of subbands provides a phenomenological explanation for the 0.7 structure, a one-dimensional (1D) nanomagnetic state, and its high-B variants.

We show that Variational Autoencoders consistently fail to learn marginal distributions in latent and visible space. We ask whether this is a consequence of matching conditional distributions, or a limitation of explicit model and posterior distributions. We explore alternatives provided by marginal distribution matching and implicit distributions through the use of Generative Adversarial Networks in variational inference. We perform a large-scale evaluation of several VAE-GAN hybrids and explore the implications of class probability estimation for learning distributions. We conclude that at present VAE-GAN hybrids have limited applicability: they are harder to scale, evaluate, and use for inference compared to VAEs; and they do not improve over the generation quality of GANs.

eng_Latn

The paper presents the modeling of subsea coaxial cable as a FIR filter on MATLAB. The subsea coaxial cables are commonly used in telecommunication industry and, oil and gas industry. Furthermore, this cable is unlike a filter circuit, which is a “lumped network” as individual components appear as discrete items. Therefore, a subsea coaxial network can be represented as a digital filter. In overall, the study has been conducted using MATLAB to model the subsea coaxial channel model base on primary and secondary parameters of subsea coaxial cable.

Static analysis forms the basis of calculations in structural design of overhead power lines. The environmental loads considered in design can be assumed static (icing) or quasi-static (idealized steady wind). However, dynamic analysis is necessary to predict line transient response to shock loads such as those induced by the sudden failure of components or sudden ice-shedding effects on the conductors. This paper summarizes a macroscopic modeling approach to line dynamic analysis where emphasis is put on capturing the salient features of the propagation of such shock loads in a line section. The approach is illustrated with a case study of a line section having suffered two tower failures due to conductor breakages during an ice storm. The cable dynamics model proposed has been applied successfully to several examples, using the commercial software ADINA.

By using a superluminescent diode as the light source and a depolariser inside the fibre coil, a constant scale factor is achieved without using polarisation control elements. For long-term behaviour an RMS-bias drift of 10 degrees/h is obtained.

eng_Latn

The Duane plot is a simple and widely used graphical technique in the analysis of repairable systems. The fitting of a straight line to points in that graph serves to determine the behavior of the system assuming a power law process. However, the classical least squares fitting suffer from lack of robustness and it is specially heavily affected by the more remote and perhaps least interesting points. In order to solve this drawback we propose a robust fit based on Least Median of Squares (LMS) or Least Trimmed Squares (LTS) regression estimators of [1] . This methodology has been applied in a project aimed to study the reliability, availability and maintainability of the aerial contact line of the Spanish railways.

In this article, a new methodology to determine the criticality of the components of the overhead contact line (OCL) system by means of a component criticality index is proposed. The methodology is based on classic failure mode and effects analysis (FMEA) but adapted to its application on this system, with characteristics far from industrial systems where FMEA was developed. The procedure is focused on the analysis of the system's operating history with the important advantage that the subjectivity of the usual procedures is reduced. This methodology has proved to be very useful when applied to decision-making and for establishing maintenance frequencies of the elements of the OCL of the Spanish railway network, and it could also be applied to other kind of large-scale distributed systems.

Smartphones may be seen as miniature toolboxes to perform Physics experiments. In this paper, we present three different “optics workbenches" mainly based on the light meter of a smartphone. One is aimed at the precise study of Malus law and other effects associated to linearly polarized light, the second allows quantifying the light intensity distribution of diffraction or interference patterns projected on a screen, and the third demonstrates the so-called inverse square law obeyed by the light from a point-like source. These experiments allow to quantitatively demonstrate three fundamental laws of optics using quite inexpensive equipment.

eng_Latn

Analysis of polarization-mode coupling by acoustic torsional waves in optical fibers

Coupling of polarization modes of the LP01 spatial mode by acoustic torsional waves in an optical fiber is considered in detail. Analytic expressions of the coupling coefficients based on the combined effects of birefringence and photoelastic contributions are found. The results show that for regular fibers the birefringence component is the larger of the two. By the use of higher radial orders of the acoustic torsional modes, the coupling efficiency can be increased.

In this paper we study the multivariate ANOVA decomposition for $1$-periodic functions on the torus. In particular we use the integral projection operator that leads to the classical ANOVA decomposition. Relationships between the Fourier coefficients of the function and its ANOVA terms lead to special frequency index sets and give an understanding of the decomposition working in the frequency domain. Moreover, we consider the truncated ANOVA decomposition and provide error bounds for approximation in $\mathrm{L}_\infty$ and $\mathrm{L}_2$. We present an approximation method based on the truncated decomposition with regard to a superposition dimension $d_s$.

eng_Latn

A wave propagation matrix method in semiclassical theory

Abstract A wave propagation matrix method is used to derive the semiclassical formulae of the multi-turning-point problem. A phase shift matrix and a barrier transformation matrix are introduced to describe the process of a particle travelling through a potential well and crossing a potential barrier respectively. The wave propagation matrix is given by the products of phase shift matrices and barrier transformation matrices. We then apply the method to study scattering by surface transparent potentials and the Bloch wave in solids.

Abstract. One of the goals, in the context of nonparametric regression by smoothing spline functions, is to choose the optimal value for the smoothing parameter. In this paper, we deal with the cross validation method(CV), as a performance criteria for smoothing parameter selection. First, we implement a CV-based algorithm, in Matlab 6.5 medium and we apply it on a test function, in order to emphase the quality of the fitting by the CV-smoothing spline function. Then, we fit some real data with this kind of function.

eng_Latn

The Flexible Dispersion-managed Optical Links with a Randomly Distributed RDPS

Dispersion management (DM), optical phase conjugation (OPC), and the combination of these two are promising techniques to compensate for the signal distortion due to group velocity dispersion and optical Kerr effects of single mode fiber. The goal of this paper is to investigate the system performance depending on the variation degree of the random variable of RDPSs in the optical links for 960 Gbps WDM transmissions.

Introduction ::: The purpose of this study is to compare the tissue incorporation of a novel fenestrated and non-fenestrated crosslinked porcine dermal matrix (CPDM) (CollaMend™, Davol Inc., Warwick, RI) in a porcine model of ventral hernia repair.

eng_Latn

Applied technique of the welding method of long distance transmission pipeline

Welding methods of long-distance transportation pipeline are essential for its manufacturing quality,reliability and security of operation.A reasonable selecting of welding methods and applying corresponding welding technology are the keys to ensure the welding quality of long-distance transportation pipeline.According to the characteristics and requirements of field welding of long-distance transformation pipeline,this paper expounds the welding methods in field welding and use situation in production site,and looks forward to the application prospects of main welding methods.

In this study, we present the analytic temperature profile in cylindrical geometry for transmissive optics. The model permits the explicit calculation of the optical path length difference across the radial direction of a rod. This allows us to determine the specific length of the compensation material to remove the thermal effect not only for a small region at the beam’s center but also for the entire geometry of the optics, including high-order aberrations for various power ranges.

eng_Latn

Experimental determination of multiple instability regions by Fourier filtering methods in a single-mirror feedback scheme

In this study, a special Fourier filtering scheme is utilized to give an experimental demonstration of a basic property of many optical pattern forming systems. This is the existence of a sequence of tongue-like instability regions at increasing values of transverse wave numbers. This work determines the boundaries of the tongues, i.e. the marginal stability curve, and compare the results with theoretical ones.

A methodology for hierarchical statistical circuit characterization which does not rely upon circuit-level Monte Carlo simulation is presented. The methodology uses principal component analysis, response surface methodology, and statistics to directly calculate the statistical distributions of higher-level parameters from the distributions of lower-level parameters. We have used the methodology to characterize a folded cascode operational amplifier and a phase-locked loop. This methodology permits the statistical characterization of large analog and mixed-signal systems, many of which are extremely time-consuming or impossible to characterize using existing methods.

eng_Latn

Marchenko Equation for Time Reversal Imaging in an Underwater Acoustic Waveguide

Time reversal (TR) has been used to acoustic imaging to recover the spatial distribution of scatterers or the source location in an underwater acoustic waveguide. This study presents a method based on Marchenko equation, and we focus on achieving acoustic source distribution inside the medium. However, to achieve accurate results for TR imaging, a detailed model of the medium should be known. Otherwise, artifacts can emerge and the results will suffer a lot from model mismatch. Our proposed methodology aims to eliminate the artifacts caused by model mismatch, and to improve the results of imaging weaker sources. To achieve this, reflection data must be acquired from a vertical array and a transducer array is also needed to emit the signal iteratively.

4 pages.-- PACS numbers: 05.45.Xt, 87.10.+e.-- ArXiv pre-print: http://arxiv.org/abs/nlin.CD/0512009.-- Final full-text version of the paper available at: http://dx.doi.org/10.1103/PhysRevE.73.055202.

eng_Latn

BOTDR optical fiber sensor temperature performance optimization based on DoE

This Paper presents the results of simulations as well as theoretical discussions on the application of temperature sensing using BOTDR optical fiber sensor which based on spontaneous Brillouin scattering.Several traditional definitions of Stimulated Brillouin Scattering(SBS) threshold power and a new definition using temperature power change coefficient is explained using the simulation model of BOTDR sensor.Due to the fact that the sensor performance is affected by several factors with interaction between each of the factors,DoE provides a statistically accurate strategy for simulation to determine the optimal settings for the constructed sensor.The result had shown SBS suppression by 8.5dBm to achieve the maximum sensing distance of up to 110km.

This paper deals with the study on the extracting conditions of flavonoid from tea.Response surface methodology was used to obtain the optimum extracting conditions by Design-Expert 6.0.The research findings show that the optimum extracting conditions were as follows:extracting 60 min,water temperature 80℃,60%alcohol,10 times volumes.

eng_Latn

Weighted Mean of Signal Intensity for Unbiased Fiber Tracking of Skeletal Muscles: Development of a New Method and Comparison With Other Correction Techniques

ObjectivesThe aim of this study was to investigate the origin of random image artifacts in stimulated echo acquisition mode diffusion tensor imaging (STEAM-DTI), assess the role of averaging, develop an automated artifact postprocessing correction method using weighted mean of signal intensities (WM

We present X-ray light curves and the energy spectra for two contact binaries SW Lac and W UMa, which are obtained from the ASCA(Advanced Satellite for Cosmology and Astrophysics) observations. We find that both sources show appreciable flux variations during the observatoins, and the variations are erratic and are not orbital-phase dependent. From a spectral analysis, we also find that the W UMa spectrum can be reproduced by a variable-abundance plasma model with a single temperature of , while the SW Lac spectrum requires two different temperatures and .

eng_Latn

Toward improved P300 speller performance in outdoor environment using polarizer

P300, which is usually evoked by visual stimulus, is widely used in electroencephalography (EEG) based brain computer interface (BCI) studies. As an application-oriented BCI study, the P300 speller would inevitably be used in outdoor environments. However, the visual stimulation effect might be interfered by the reflections in outdoor environment. This paper attempted to improve the outdoor P300 speller performance by using polarizer. Six subjects participated our two experiments, each experiment was conducted three times under three different conditions. The results demonstrated that a suitable polarizer can indeed improve the performance of outdoor P300 speller.

This paper describes a new methodology of estimating free-space optical communications link budgets to be expected in conditions of severe turbulence. The approach is derived from observing that the ability of an adaptive optics (AO) system to compensate turbulence along a path is limited by the transmitter and receiver Rayleigh range, proportional to the diameter of the optics squared and inverse of the wavelength of light utilized. The method uses the Fried parameter computed over the range outside of the transmitter and receiver Rayleigh ranges, to calculate the Strehl ratios that yield a reasonable prediction of the light impinging on the receiving telescope aperture and the power coupling into the fiber. Comparisons will be given between theory and field measurements. These comparisons show that AO is most effective within the Rayleigh ranges, or when an atmospheric gradient is present, and lesser so when the total range is much greater than the sum of the Rayleigh ranges.

eng_Latn

Second-harmonic generation by off-axis propagation in an anisotropic optical waveguide

Second-harmonic generation (SHG) by means of radiation modes (the Cerenkov-type radiation scheme) in an anisotropic optical waveguide by off-axis propagation has been studied theoretically. If the second-harmonic wave is a leaky wave of the waveguide, the Cerenkov-type SHG efficiency may be comparable with the efficiency of the guided-mode–guided-mode SHG without critical control of the wave-vector-matching condition. The model presented predicts a strong modification of the radiation field by a change of the interaction length. A numerical simulation of the proposed type of SHG in a graded-index waveguide on the X-cut surface of LiNbO3 is made.

This paper deals with robust estimation of states and unknown inputs for a class of non linear system described by Takagi-Sugeno fuzzy models. The proposed approach is developed on the basis of adaptive Luenberger observer theory. A robustness study, using the L 2 technique, is carried out to take in consideration the model uncertainties. Unknown inputs estimation is ensured through a fuzzy proportional integral adaptive law, computed from an accurate observer outputs which allow a fast dynamic estimation. Design conditions are formulated into Linear Matrix Inequalities (LMIs) terms. Numerical example is given to illustrate the efficiency of the proposed techniques.

eng_Latn

Numerical Study of Interactions Between Phase II of OC4 Wind Turbine and Its Semi-Submersible Floating Support System

The motion response of the floating support system is critical in designing and confirming the safety and efficiency of an offshore wind turbine. This paper aims to study the interaction between the wind turbine and its semi-submersible floating system for Phase II of the Offshore Code Comparison Collaboration Continuation (OC4) project. First, the validation of wave generation and damping is performed to guarantee the accuracy of waves. Then, the grid convergence is studied to eliminate the influence of different grids. Last, the motion of the semi-submersible floating system in specific waves is compared with a parked wind turbine and with an equivalent operated wind turbine. The equivalent forces and moments of the NREL 5-MW in different wind speeds have been exerted on the rotational center of the semi-submersible floating system. The results show the influences of the wind turbine on the supporting system in waves.

We proposed a simple method to realize optical Fourier transform during the nonlinear wave shaping processes. In this method, an integrated optical superlattice is designed to realize multiple optical functions, which plays important roles in both the nonlinear harmonic generation process and the optical Fourier Transform process. We demonstrated our method by the nonlinear generation of Airy beams as an example. It is a universal method for beam shaping and is of practical importance for designing compact nonlinear optical devices.

eng_Latn

Characteristics of propagation function of Plane wave diffracted by small circular band

Based on the scalar diffraction theory and the boundary condition of Rayleigh-Sommerfeld,the accurate on-axis propagating wave function of plane wave diffracted by small circular band is obtained by solving the first integral of Rayleigh-Sommerfeld.By means of the function,the extremas of on-axis light intensity,the locations and number as a function of the radius of small circular band are analyzed,and then extend the conclusion as the inner radius trends to zero or outer radius trends to infinity.This study offers the conclusion not only for the application of engineering and technology but also for the optics education.

This paper considers a method to realize a two-valued input three-valued output function f:{0, 1}/sup n//spl rarr/{0, 1, 2} by using a cascade of four-input cells. Decomposition of a group function is used to find a canonical form. We show that the Walsh spectrum specifies the canonical form, and the number of non-zero coefficients in the spectrum is proportional to the number of cells in the cascade. Finally, we show a design algorithm for a p-valued function f:{0, 1}/sup n//spl rarr/{0, 1, ..., p-1}. The designed cascades are reversible and conservative.

eng_Latn

what does otdr stand for in fiber optics

New: Download a free OTDR Simulator for PCs. After you study this page, you can download a free OTDR simulator to run on your PC. The Optical Time Domain Reflectometer (OTDR) is useful for testing the integrity of fiber optic cables. It can verify splice loss, measure length and find faults. The OTDR is also commonly used to create a picture of fiber optic cable when it is newly installed.

SFDR is defined as the ratio of the RMS value of the carrier wave (maximum signal component) at the input of the ADC or output of DAC to the RMS value of the next largest noise or harmonic distortion component (which is referred to as a “spurious” or a “spur”) at its output.

eng_Latn

An ab initio computational study of the properties of four linear dihydrogen-bonded complexes pairing MH2 (M = Zn, Cd) with HCCRgF (Rg = Ar, Kr) was undertaken at the MP2/DGDZVP level of theory. The calculated complexation energies of the linear complexes vary between 6.5 kJ/mol for M = Zn to 8.5 kJ/mol for M = Cd. Equilibrium interatomic H...H distances are roughly 2.07 A for all four complexes. The red shifts of the H-C stretching frequency of HCCRgF correlate nicely with the interaction energies.

In the present investigation, we performed a thorough study of potential energy curves, rovibrational spectra, and spectroscopic constants for complexes pairing via dihydrogen bonds. In particular, we dealt with LiH···HX (X = F, CN, CCH, CCF, CCCl) complexes by employing accurate electronic energy calculations at the MP2/aug-cc-pVDZ level of theory. Following this, the Numerov method was applied to solve the nuclear Schrödinger equation, thus obtaining spectroscopic constants and rovibrational spectra. Good linear correlation between the magnitudes of the interaction energies for interaction of HX with LiH, and the most positive electrostatic potentials of hydrogen in HX, was established.

We prove uniform local-in-time existence and uniqueness of solutions to the density-dependent magnetohydrodynamic equations.

eng_Latn

The hyperpolarizability has been extensively studied to identify universal properties when it is near the fundamental limit. Here, we employ the Monte Carlo method to study the fundamental limit of the second hyperpolarizability. As was found for the hyperpolarizability, the largest values of the second hyperpolarizability approaches the calculated fundamental limit. The character of transition moments and energies of the energy eigenstates are investigated near the second hyperpolarizability's upper bounds using the missing state analysis, which assesses the role of each pair of states in their contribution. In agreement with the three-level ansatz, our results indicate that only three states (ground and two excited states) dominate when the second hyperpolarizability is near the limit.

Sum rules have been used to show that there is an upper limit to molecular susceptibilities. Such calculations have been applied to the diagonal part of the second-order susceptibility tensor as measured with electric-field-induced second-harmonic generation, and to a variety of third-order measurements. The results show that the off-resonant susceptibilities of all molecules measured fall within the calculated limits. In this contribution, we show that the most susceptibilities measured with hyper Rayleigh scattering (HRS) fall below the two-dimensional theoretical limit, and discuss the issue of why some molecules appear to break this limit.

Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights.

eng_Latn

The partial molar volume of ions in water furnishes an indication, if not precise information, about the nature of ionic solvation (1–5). Accordingly, it was hoped that differences in this term and particularly the effect of temperatures on the differences in the apparent partial molar volume for a series of ions in light and heavy water would provide a basis for decisions on the nature of solvation of the benzenesulfonic ion. This ion is of considerable interest in the study of solvolysis, but very little is known about the characteristics of solvation.

The surface chemistry of aqueous solutions plays a ubiquitous role in many chemical and biological processes. Here, the authors probe the surfaces of sodium halide solutions with surface-specific femtosecond vibrational spectroscopy, and observe surface concentrations of halide ions several times greater than in the bulk.

We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero.

eng_Latn

Directed Self-Assembly of Quantum Dots in a Nematic Liquid Crystal

Self organizing anisotropic nematic liquid crystals (LCs) induce self-assembly on quantum dots (QDs) to form one-dimensional chains along the nematic director. Spatial ordering of QDs, achieved in the nematic LC matrix, can be controlled in a preferred direction on application of electric fields, gaining better self-assembly. Once the field goes off, the LC+QD system relaxes back to the original state, revealing the intrinsic dynamics. Due to the dielectric anisotropy of the system, this dynamic response can be captured by studying dielectric relaxation. The studied dynamic response reveals insights on the field-induced self-assembly mechanism and the stability of the LC+QD system.

This paper comments the letter entitled "Network analysis of the state space of discrete dynamical systems" by A. Shreim et al. [Physical Review Letters, 98, 198701 (2007)]. We found that some theoretical analyses are wrong and the proposed indicators based on parameters of phase network can not discriminate dynamical complexity of the discrete dynamical systems composed by 1-D Cellular Automata.

eng_Latn

Polyelectrolytic aspects of the titration curve. The semi-flexible model.

An analysis is given of the theoretical approach to the quantitative description of proton dissociation curves for weak polyacids. The basic model of the counterion condensation theory has been used, with the modification reported in the preceding study (S. Paoletti, A. Cesàro, C. Arce Samper and J.C. Benegas, Biophys. Chem. 34 (1989) 301). In this paper we demonstrate the effect of relaxing the hypothesis of a rigid conformation on the polyelectrolytic properties of weak polyacids. As an application of the present approach, a description is given of the titration curves for two weak polyacids, poly(DL-glutamic acid) (PDLGA) and poly(L-aspartic acid) (PLAA).

We will now develop the approximation theory appropriate for the finite elements developed in Chapter 3. We take a constructive approach, defining an averaged version of the Taylor polynomial familiar from calculus. The key estimates are provided by some simple lemmas from the theory of Riesz potentials, which we derive. As a corollary, we provide a proof of Sobolev’s inequality, much in the spirit given originally by Sobolev.

eng_Latn

Optimisation of molecular structure for traction fluids

According to the guidelines for the molecular design of traction base fluids obtained from a previous study, more than 100 chemical compounds have been synthesised. Employing 61 naphthenic compounds whose chemical structures have been clearly identified, the optimisation of molecular structure has been studied regarding the compatibility of high-temperature traction coefficient and low-temperature fluidity. As a result, the requirements for molecular structures for high-performance traction base fluids have been clarified.

A reconstruction method of soot volume fraction and temperature distribution based on back-projection of flame image dual-channel intensities was proposed.The cross-section contour profiles of ethylene/air non-premixed axisymmetric flame were reconstructed.The results show that the inner ethylene gas was not thoroughly ignited before the middle of the flame,where the maximum cross-section average temperature and volume fraction occurred.The maximum fraction occurs near flame edge and is vulnerable to temperature change or oxygen concentration variation.

eng_Latn

The CO chemisorption on some active sites of Pd clusters : A DFT study

Abstract The CO adsorption on Pd, Pd 2 and Pd 4 small clusters was studied using density functional methods; the theoretical results obtained here were compared with experimental vibration frequencies of CO adsorbed on supported Pd-nanoparticles. The results indicate that the CO adsorption over Pd 2 and Pd 4 clusters give CO vibration frequencies values closed to the experiment values. Also, the theoretical results for the threefold hollow sites were compared with other nanoclusters, with n >50 atoms, where the Pd 4 cluster also give values closed to the experiment. According with the results, two and four atoms small clusters could be used to model the active interaction sites between a gas molecule like CO and Pd nanoparticle.

The correlation suggested by van Noort1 in his Comment on our paper2 is an improvement of the Simamura correlation.3 Unfortunately, there is not sufficient information in our paper2 to compare both approaches. The uncertainties cited in ref 2 are not statistical but an expert’s estimation of the uncertainties of unknown melting points. The average deviations of experimental and estimated values from our correlation are 10 K for 61 chlorine-substituted dioxins (PCDDs) and 15 K for 59 chlorine-substituted dibenzofurans (PCDFs). The corresponding graphs are presented as Figures 1 and 2. So, our correlation is considerably better for PCDDs and the same for PCDFs. Literature Cited

eng_Latn

Hydrogen bonding: Part 20. Infrared study of the high temperature β-form of choline chloride

Abstract Infrared spectral studies of β-choline chloride at 95°C clearly demonstrate the presence of OH … Cl hydrogen bonding. This observation contradicts an earlier conclusion, based on X-ray structural studies, that such hydrogen bonding could not occur in this high-temperature form of choline chloride. A moderate reinterpretation of the X-ray data may reconcile these contradictory conclusions. Unlike α-choline chloride, β-choline chloride does not show CH … Cl hydrogen bonding. It is possible that loss of CH … Cl hydrogen bonding is a factor in the marked difference in radiation sensitivity of the α- and β-forms.

A flow boiling heat transfer experiment platform was designed and built using alternative refrigerant R134a as the working fluid.It can be used for investigation on two-phase flow and boiling heat transfer characteristics and fluid-to-fluid modeling of critical heat flux.Some problems concerning the materials,welding,sealing,thermal insulation,special machining and accessories are discussed in detail.

eng_Latn

Direction of separation and dependence of feed concentration in liquid thermogravitational columns

Abstract The direction of separation in a thermogravitational column was studied for 12 binary mixtures with the following components: Benzene, toluene, n-hexane, n-heptane, cyclohexane, carbon tetrachloride, tetrabromoethane, and tetrachloroethane. The separation sign is governed by the density of the components. A study was also made of the effect of feed concentration on the separation value. The shape of the curve relating separation and charge concentration was found to depend strongly on “molecular mobility” and molecular structure.

Abstract : The report contains a brief analysis of the following items: (a) Two-dimensional steady flow (variational method), (b) One-dimensional unsteady flow (variational method), (c) Plasma with finite conductivity (exact solutions), (d) Approximate solutions and linearized equations, (e) New numerical methods, (f) Low conductivity plasma, (g) Applications, (h) Plasma acceleration and MHD power generation. A detailed discussion of future plans is given. (Author)

eng_Latn

Theory of preferential solvation of nonelectrolytes

The concepts of local compositions around a solute and preferential solvation of a solute are defined in terms of the Kirkwood-Buff integrals. The difference between the local and the bulk composition is a measure of the preferential solvation of a solute with respect to the various components of the solvent. A statistical mechanical theory is developed that leads to simple relationships between local compositions and experimentally measurable quantities. Some preliminary results on preferential solvation of methane in mixtures of water-ethanol and water-p-dioxane are presented.

Abstract We study a general nonlinear elliptic equation in the Orlicz setting with data not belonging to the dual of the energy space. We provide several Lorentz-type and Morrey-type estimates for the gradients of solutions under various conditions on the data.

eng_Latn

TÉLOMÉRISATION ENÉMULSION DU STYRÈNE AVEC LES MERCAPTANS

Abstract The telomerization in emulsion of styrene is studied with two transfer agens: thioglycolic acid and 1,1,2,2-tetrahydro perfluorooctane thiol. The influence of the telogen-amount vs the degree of telomerization, that of the surfactant concentration and that of the nature of the initiator are investigated. The telomerization of this monomer with these aliphatic mercaptans is possible in aqueous medium whatever the solubility of the thiols in water. Transfer constants of both these mercaptans were determined as 1.60 and 1.16 for thioglycolic acid and the fluoronated thiol, respectively. © 1997 Elsevier Science Ltd. All rights reserved

We study in perturbative QCD the helicity amplitudes of the process ${\ensuremath{\gamma}}^{*}\stackrel{\ensuremath{\rightarrow}}{p}\ensuremath{\rho}p$ at large virtualities Q of the photon ${\ensuremath{\gamma}}^{*}.$ We estimate all spin-flip amplitudes taking into account an important effect of the scale behavior of the gluon density. The transition of a transverse virtual photon to a longitudinal vector meson is not small at typical conditions at the DESY ep collider HERA. This helicity nonconserving amplitude leads by interference to a measurable effect in the distribution of the angle between the electron scattering and the meson production planes.

yue_Hant

Les méthodes de déconvolution et leurs limitations fondamentales

2014 We deal first with the analogy between physical linear systems and convolution equations, and show the theoretical difficulties encountered when solving such equations (existence, uniqueness...). We define precisely the words deconvolution, apodization used by physicists. We then make a survey (not intended to be exhaustive) of deconvolution methods and algorithms currently proposed by severals authors. In the end we study, when possible, the limitations due to various noises appearing at different levels of the measurement and how, in some circumstances, an a priori information may decrease the importance of these limitations. REVUE DE PHYSIQUE APPLIQUEE TOME 11, MARS 1976, PAGE

Hydratation des cis- et trans-cyclooctenes et du dimethyl-2,3 butene-2 en alcools correspondants dans divers milieux

fra_Latn

Monohydride and dihydride formation at Si(100) 2x1: A high resolution electron energy loss spectroscopy study

Abstract Results from EELS and LEED investigations on the interaction of atomic hydrogen with the Si(100) 2x1 surface give direct evidence for the formation of two distinct surface phases: a monohydride Si(100) 2x1:H and a dihydride Si(100) 1x1::2H phase. Temperature and exposure time determine which of the two phases appears. An analysis of normal vibrational modes leads to an identification of hydrogen adsorption complexes in both phases.

We present Monte Carlo simulation results for square-well homopolymers at a series of bond lengths. Although the model contains only isotropic pairwise interactions, under appropriate conditions this system shows spontaneous chiral symmetry breaking, where the chain exists in either a left- or a right-handed helical structure. We investigate how this behavior depends upon the ratio between bond length and monomer radius.

eng_Latn

Synthesis and structure determination of helical polymers

The recent remarkable progress in structural investigations of helical polymers by high-resolution atomic force microscopy provides their exact helical structures including helical pitch and handedness. Seeing is believing!

In this study muon-spin rotation (μSR) serves as a tool for sensitive monitoring of the environment of muoniated radicals in isotropic liquids. A systematic investigation of the behaviour of the hyperfine coupling constants of cyclohexadienyl-type radicals is performed, and it is found that they are in linear dependence on solvent polarity, with certain deviations. These deviations are discussed in detail. It is found that with increasing length of the hydroxyalkyl substituent group the perturbation of the phenyl ring becomes smaller.

eng_Latn

Chemical reaction rates of quasi-free electrons in non-polar liquids. The equilibrium CO2 + e− CO2−☆

The forward and reverse rates of the reaction CO2 + e− CO2− were determined in tetramethylsilane, neopentane and 2,2,4-trimethylpentane as a function of temperature. The forward reaction is exothermic in solution but the equilibrium constant shifts over four orders of magnitude with changes in solvent. The change in entropy for the forward reaction is approximately the same (−44 cal/mol degree) in the three solvents.

Let a neuronal population be composed of an excitatory group interconnected to an inhibitory group. In the Wilson-Cowan model, the activity of each group of neurons is described by a first-order nonlinear differential equation. The source of the nonlinearity is the interaction between these two groups, which is represented by a sigmoidal function. Such a nonlinearity makes difficult theoretical works. Here, we analytically investigate the dynamics of a pair of coupled populations described by the Wilson-Cowan model by using a linear approximation. The analytical results are compared to numerical simulations, which show that the trajectories of this fourth-order dynamical system can converge to an equilibrium point, a limit cycle, a two-dimensional torus, or a chaotic attractor. The relevance of this study is discussed from a biological perspective.

eng_Latn

Analysis of 19F and 13C NMR spectra of tetrafluorophthalic anhydride and its derivatives

Abstract 19 F and 13 C NMR spectra of perfluorinated compounds (i.e., tetrafluorophthalic anhydride, its hydroxyl- and amino-derivatives, N-pentafluorophenyltetrafluorophthalimide, and hexafluoroindan-1,3-dione) were analysed. Different signals in NMR spectra were assigned based on the analysis of spin–spin coupling constants. All assignments made were further confirmed by density functional theory (DFT) calculations of 13 C chemical shifts and J C,F coupling constants.

We study the basic properties of tensor random fields (TRFs) of the wide-sense homogeneous and isotropic kind with generally anisotropic realizations. Working within the constraints of small strains, attention is given to antiplane elasticity, thermal conductivity, classical elasticity and micropolar elasticity, all in quasi-static settings albeit without making any specific statements about the Fourier and Hooke laws. The field equations (such as linear and angular momentum balances and strain–displacement relations) lead to consequences for the respective dependent fields involved. In effect, these consequences are restrictions on the admissible forms of the correlation functions describing the TRFs.

eng_Latn

Liouvillian and Algebraic Solutions of Second and Third Order Linear Differential Equations

Abstract In this paper we show that the index of a 1-reducible subgroup of the differential Galois group of an ordinary homogeneous linear differential equation L ( y ) = 0 yields the best possible bound for the degree of the minimal polynomial of an algebraic solution of the Riccati equation associated to L ( y ) = 0. For an irreducible third order equation we show that this degree belongs to {3,6,9,21,36}. When the Galois group is a finite primitive group, we reformulate and generalize work of L. Fuchs to show how to compute the minimal polynomial of a solution instead of the minimal polynomial of the logarithmic derivative of a solution. These results lead to an effective algorithm to compute Liouvillian solutions of second and third order linear differential equations.

Self organizing anisotropic nematic liquid crystals (LCs) induce self-assembly on quantum dots (QDs) to form one-dimensional chains along the nematic director. Spatial ordering of QDs, achieved in the nematic LC matrix, can be controlled in a preferred direction on application of electric fields, gaining better self-assembly. Once the field goes off, the LC+QD system relaxes back to the original state, revealing the intrinsic dynamics. Due to the dielectric anisotropy of the system, this dynamic response can be captured by studying dielectric relaxation. The studied dynamic response reveals insights on the field-induced self-assembly mechanism and the stability of the LC+QD system.

eng_Latn

Inelastic-neutron-scattering study at low temperature of the quantum sine-Gordon breather in 4-methyl-pyridine with partially deuterated methyl groups.

Abstract Inelastic neutron scattering spectra of 4-methyl-pyridine with the partially deuterated methyl (4MP-CH 2 D) are interpreted within the quantum sine-Gordon theory. The bands are assigned to the quantized travelling states of the breather. The band splitting corresponds to different chain conformations.

Equations have been developed for describing the isotherms of extraction of rare-earth metal(III) [REM(III)] nitrates from aqueous concentrated solutions by 100% diisoamyl methylphosphonate, taking into account the variation of activity coefficients of components in the organic phase when its composition is varied within broad limits. The thermodynamic parameters of the extraction equilibria have been calculated using as the standard states hypothetical one-molal aqueous REM(III) nitrate solutions and pure components of the organic phase at a mole fraction of 1.0.

eng_Latn

Two-step process for aromatics production from natural gas/shale gas condensates

The aromatics production system is useful for producing an aromatics-rich system product from a liquid hydrocarbon condensate includes a hydroprocessing reactor, an aromatization reactor system and a hydrogen extraction unit. The method for producing the aromatics-rich system product from the wide boiling range condensate includes introducing the wide boiling range condensate into the hydroprocessing reactor, operating the aromatics production system such that the hydroprocessing reactor forms a naphtha boiling temperature range liquid product, such that the aromatization reactor system forms the aromatics-rich system product, and such that the hydrogen extraction unit forms a high-purity hydrogen.

Abstract We study the dynamics of a wrinkled flame held downstream of a cold, isothermal, flat burner The analysis is conducted in the framework of a thermal diffusional flame model. An Arrhenius rate with a large activation temperature and a single reactant with Lewis number unity are postulated We show that the nonlinear evolution equation for the front shape and position is no longer local, neither in time nor in space, when the flame is sufficiently close to the burner surface.

eng_Latn

Evidence for phase separation of ethanol-water mixtures at the hydrogen terminated nanocrystalline diamond surface

Interactions between ethanol-water mixtures and a hydrophobic hydrogen terminated nanocrystalline diamond surface, are investigated by sessile drop contact angle measurements. The surface free energy of the hydrophobic surface, obtained with pure liquids, differs strongly from values obtained by ethanol-water mixtures. Here, a model which explains this difference is presented. The model suggests that, due to a higher affinity of ethanol for the hydrophobic surface, when compared to water, a phase separation occurs when a mixture of both liquids is in contact with the H-terminated diamond surface. These results are supported by a computational study giving insight in the affinity and related interaction at the liquid-solid interface.

Abstract Bubbles of inviscid fluid surrounded by a viscous fluid in a Hele–Shaw cell can merge and break off. During the process of break-off, a thinning neck pinches off to a universal self-similar singularity. We describe this process and reveal its integrable structure: it is a solution of the dispersionless limit of the AKNS hierarchy. The singular break-off patterns are universal, not sensitive to details of the process and can be seen experimentally. We briefly discuss the dispersive regularization of the Hele–Shaw problem and the emergence of the Painleve II equation at the break-off.

eng_Latn

H2 formation from Polycyclic Aromatic Hydrocarbon molecules

In this work we study statistical fragmentation of Polycyclic Aromatic Hydrocarbon (PAH) molecules following collisions with keV ions. Dissociation and transition state energies for H- and H2-emissions from PAHs have been calculated and a simple electronic stopping model has been used to calculate collision-induced internal PAH temperatures. We find that H2 may be formed efficiently from pristine PAHs for internal ion temperatures above 2200 K.

Polymerisation en solution de diacides carboxylique en presence de phosgene a temperature ambiante

eng_Latn

Phase equilibrium in low-density polyethylene — Normal alkanes systems

The crystalline equilibrium diagrams were obtained for eigh LDPE—n-alkane systems with the cloud point method. A point of view was formulated in which there is a major difference between crystal separation in lowmolecular-weight systems and systems containing flexible macromolecules, and it derives from differences in the essence of the phase transitions that take place in these systems.

This book, which was first published in Russian in 2005, deals with the homogenization of partial differential equations (pdes) of elliptic and parabolic types. The authors study both boundary value problems posed in highly perforated domains or equations with rapidly oscillating coefficients. The standard theory of homogenization (periodic theory, uniformly elliptic oscillating coefficients) is supposed to be already known and the emphasis is put on nonstandard situations leading to multicomponent or nonlocal equations.

eng_Latn

Many scientific techniques exploit NMR phenomena to study molecular physics , crystals , and non-crystalline materials through NMR spectroscopy .

Many scientific techniques exploit the NMR phenomena to study molecular physics , crystals and non crystalline materials through NMR spectroscopy .

The report recommendations include : greater data collection of air and water data , `` rigorous '' air pollution standards and mandatory disclosure of chemicals used in the hydraulic fracturing process .

eng_Latn

Effects of Translational Nonequilibrium in the Shock Wave Front in Dense Gases and Liquids

On the basis of the generalized Enskog kinetic equation, the problem of the structure of a shock wave in dense reacting gases and liquids is solved. It is shown that the physicochemical processes in the zone of translational nonequilibrium (ZTN) in the shock wave front do not obey the Arrhenius kinetics. The rates of high-threshold processes in the ZTN in the shock wave front may exceed these rates in equilibrium behind the front by a factor of 106 and more. An analytical expression is obtained for the rate constant of nonequilibrium processes in the front. Comparison of the results of calculation of the yield of products with broken double bond in the benzene molecule with the experimental data reveals that the formation of these products proceeds by the mechanism of nonadiabatic collisions realized under highly nonequilibrium conditions.

We study in this paper the properties of a two-body random matrix ensemble for distinguishable spins. We require the ensemble to be invariant under the group of local transformations and analyze a parametrization in terms of the group parameters and the remaining parameters associated with the 'entangling' part of the interaction. We then specialize to a spin chain with nearest-neighbour interactions and numerically find a new type of quantum-phase transition related to the strength of a random external field, i.e. the time-reversal-breaking one-body interaction term.

eng_Latn

what is a solvent solute and solution

A solvent is a substance which dissolves a solute. When a solvent dissolves into a solute, it creates a solution. If i pour salt into a cup of water. The salt is the solute because it's being dissolved and the water is the solvent because it is doing the dissolving.

home / study / science / chemistry / chemistry questions and answers / What Is The Strongest Type Of Intermolecular Force Between Solute And Solvent In Each Solution? ... Question: What is the strongest type of intermolecular force between solute and solvent in each solution? ... Show transcribed image text What is the strongest type of intermolecular force between solute and solvent in each solution?

eng_Latn

Broken rotor bar fault diagnosis using fast Fourier transform applied to field-oriented control induction machine: simulation and experimental study

DWT for rotor bars fault detection applied to backstepping control induction motor drive in low-speed

Transcriptional activation of HIF-1 by a ROS-ERK axis underlies the resistance to photodynamic therapy

eng_Latn

The torque monitoring of high-speed rotary shaft is often unsuccessful because of sensor installation, reliability, accuracy and other practical issues, so high-speed rotary shaft torque monitoring has become an urgent need. The brushless torque sensor is developed based on strain measurement, which transformed the torque to the deformation of the shell, the torque value is obtained by strain measurement of the shell, the measurement error is less than 4% by experimental verification. In a torque measurement of cold rolling mill main transmission shaft, the torque vibration data is verified by inherent characteristic simulation of rolling mill drive system, and the torque amplitude data is verified by motor power and speed signals. It is proved that the strain brushless torque sensor is feasible and the measurement result is correct, which provides a basis for other high-speed rotating shaft torque detection works.

Since the torque sensor is applied widely,it is necessary to study it.After analyzing the theory of typical elastic elements,the enforcing method for 5 forms of strain torque sensor are presented,in which strain,torsional deformation and natural frequency of torsional vibration is analyzed in theory and relative mechanical models are established respectively.Taking the minimum volume of torsion deformation as the goal function,the optimal design for the geometric dimension of the elastic element is conducted as well as the performance difference among different forms of toque sensors.Finally,a strain torque sensor is designed,and the FEA simulation of the sensor is completed,which result rectifies the mechanical model of torque sensor.Thus the computation problems in designing strain torque sensor are solved.

We prove that groups acting geometrically on delta-quasiconvex spaces contain no essential Baumslag-Solitar quotients as subgroups. This implies that they are translation discrete, meaning that the translation numbers of their nontorsion elements are bounded away from zero.

eng_Latn

Aimed at the intelligent car adopts speed closed-loop control strategy,precise value of car speed is required,the thesis designs speed measurement sensors and signal processing circuits.By studying different digital speed measurement algorithms,high theoretical speed measurement precision can be obtained with M/T method in the wide range of driving speed according to digital speed measurement principle.At the same time,M/T speed measurement algorithm is achieved on the hardware basis of freescale S12 single chip.Speed sensor signal is simulated by Signal Generator(SG),and the advantages of M/T speed measurement algorithm are proved with experiments.As the result,theoretical basis and program designing examples are provided for the speed measurement of intelligent car.

In developing a tiny crawler-type cultivator, the chassis speed needs to be accurately obtained in order to meet the requirements of precision agriculture for straight walking. This paper focuses on solving the problem of chassis speed measurement. Firstly, the principle of speed measuring device and the special M/T method is introduced. Then we use STM32F407ZGT6 as the hardware development environment and give the program flow chart to achieve the special M/T method. Finally, according to the demand of this project, the experimental results are obtained by taking different data, which prove the reliability of the special M/T method.

In developing a tiny crawler-type cultivator, the chassis speed needs to be accurately obtained in order to meet the requirements of precision agriculture for straight walking. This paper focuses on solving the problem of chassis speed measurement. Firstly, the principle of speed measuring device and the special M/T method is introduced. Then we use STM32F407ZGT6 as the hardware development environment and give the program flow chart to achieve the special M/T method. Finally, according to the demand of this project, the experimental results are obtained by taking different data, which prove the reliability of the special M/T method.

eng_Latn

It is shown that B.C. Moore's balancing model (1981) can be extended to unstable systems by utilizing two weighted Grammian matrices. It is proposed that the J omega axis can be shifted to handle unstable systems. The balanced approach involves the solution of two modified Lyapunov equations. Two numerical examples are given to illustrate the results. >

This project is directed at the third generation of heart pumps being developed in commercial research laboratories which employ feedback-controlled magnetically levitated pump impellers. Unique features of the control problem are the quasi-periodic pressure disturbances of the natural heart and nonlinearities of the magnetic levitation system. The main motivation for this paper is the power consumption due to quasi-periodic disturbance of natural heart. Since clinical studies are not possible for the vast majority of our work, there is a need for an apparatus to simulate the left ventricular assist device (LVAD) for controller design. Inspired by this need, we design a novel experimental apparatus to study the Maglev LAVDs. We develop a nonlinear model, then a linearized model followed by simulation and stabilization of the closed-loop system using a virtual zero power (VZP) controller.

Berzelius failed to make use of Faraday's electrochemical laws in his laborious determination of equivalent weights.

eng_Latn

Ultrasonic quality control of press-fit joints

A technique for quantitatively evaluating the quality of interference-fit joints by the echopulse method is proposed. A formula is obtained for calculating the value of the coefficient of ultrasound reflection from the site of the joint fit from the measured amplitudes of echo pulses in a free ring and in an assembled joint. It is shown that the reflection coefficient is the main parameter characterizing the quality of an interference-fit joint, i.e., its ability to withstand loads, determined by the maximum value of the torque transferred by a pressure joint, because the reflection coefficient is related to the normal stresses at the contacting surfaces of the joint. To optimize the process of studying the quality of a joint, it is noted that the automation of the testing procedure using the proposed technique is possible and desirable.

This paper discusses the conception of virtual instrument and the application of data collecting system with USB in the hydraulic measurement system, analyzes the basic features of USB and NI Compact-DAQ, and idiographic realizing methods for building the hydraulic test system. Through the test, the each technical specification of system has met the design requirements.

eng_Latn

A Parametric Study on Admittance Signatures of a PZT Transducer Under Free Vibration

Piezoelectric material is proven to be a versatile collocated sensor and actuator. Its specific application includes electromechanical impedance (EMI)-based structural health monitoring (SHM). To date, several EMI models are available in the literature but parametric studies are scarcely available. This study aims at providing a parametric study on selected models, considering a freely vibrating piezoelectric transducer. The effect of varying mechanical and electrical parameters of the transducer on the admittance signatures was investigated. The theoretical results were compared against the experiments. Accuracy of the model was successfully refined upon model updating.

Abstract The problem of diagnosing a fault or a perturbation in a dynamical system (be it industrial or natural) can be restated as the characterization of the transfer function of a filter that acts on a “sane” or “unperturbed” system to transform it into a “faulted” or “perturbed” one. This filter would then be approximated as time-invariant (and linear) only for short time windows, while the time evolution of such transfer function on longer time scales leads to a simple but powerful general framework that allows to diagnose the onset and/or the time evolution of a fault or perturbation of the system.

eng_Latn

Shock Source Assessment of a Separation Nut

The shock output of a pyrotechnic separation nut is presented and the events contributing to the overall shock output are identified. Events are separated into ignition, internal impacts, and thread segment bolt release. The events are isolated and the resulting shock response spectrums are compared against the overall SRS. The results indicate that, for the separation nut under study, the ignition event is not a contributor to the overall output shock and that the thread segment/ bolt release primarily drives the high frequency component of the shock output.

This paper describes the application of a parameter optimizing technique to determine numerical values for a circuit model of a squirrel-cage induction machine. The model includes the effects of magnetic saturation of the main and leakage flux paths and skin effect in the rotor bars. All parameters have been measured at different voltage levels up to the rated value to demonstrate the effect of magnetic saturation.

kor_Hang

The Pulsating Stroke Box Structure Improvements of SSS-Type Vertical Ring and High Gradient Magnetic Separator

This paper describes the pulsating stroke box’s role in the process of magnetic separation,and its some improvements on structure in order to optimize performance and enhance its service life: the support structure of reciprocating shaft,the sealing of reciprocating shaft’s stretched side and the stroke adjustment.The improved pulsating stroke box structure is stable performance,compact,easy to use and long life.

The author discusses the stability of the slip power recovery generator (SPRG), in open loop and in closed loop, for applications like the exploitation of ocean wave energy by water column devices. The stability study was performed using small displacement models for each of the following situations: SPRG in open loop, SPRG with inner current loop, and SPRG with active power regulation. Numerical results obtained for an experimental 3.2 kVA prototype are presented. >

eng_Latn

Study Various Defects of Ball Bearings through Different Vibration Techniques

The main objective of this study is to evaluate ball bearing defects under different operation conditions through vibration measurements. There are several tests conducted for healthy and defective bearing under variable speeds and load conditions. Experimental tests are conducted for six sets of ball bearings. Initially, a good bearing is fastened in the test rig and vibration signals are measured using the FFT analyzer to show the base-line performance of a healthy bearing. Then, the good bearing is exchanged by defective bearing and vibration signals are measured for each case separately under the same operation condition. Frequency domain, time domain and root-mean-square are used to describe various bearing defects. The experimental results are showed that each one of these methods is useful to identify the bearing problems. Also, the results proved that the significant variation in the root-mean-square at different rotational speed.

Harvey J. Finison (Equipment Laboratory, Wright Field, Dayton, Ohio): One of the greatest problems in brush wear testing has been the selection of test conditions representative of service conditions. Selection of test conditions considerably more severe than actual operating conditions may result in elimination of brushes capable of giving excellent service performance, in fact, superior to those which may be selected on the basis of more severe tests.

eng_Latn

Influence of Motorcycle Noise on Gear Transmission

The study of motorcycle's acoustic signal shows that gears noise take a great proportion on the whole acoustic of motorcycle.So how to control the noiseof gears is very helpful for reducing the whole motor's acoustic.This paper discusses the engine matching with transmission system in reason,primary transmission and gear geometry design parameter the mend of tooth body(tooth form tooth direction) how to influence the acoustic of motorcycle.The study shows that the gear transmission System's matching with engine in reason can notable improve the efficiency of motorcycle.In the meaning time the exactly choosing the primary transmission gear geometry design parameter and the mend of primary transmission gear's tooth body can effectively reduce the acoustic of motorcycle.This paper has engineering practice sense.

This paper describes a measurement technique suitable for characterizing nonlinear microwave devices operating under multi-frequency excitation. A dual six-port network analyzer configured for simultaneous load-pull and source-pull measurement allows the characterization of nonlinear devices under multi-tone excitation, for use as mixers and broadband power amplifiers. The performance of a particular circuit can be optimize as a function of source and load impedances, at each input and output signal frequencies. Measurement results for the MESFET NE 76184, resistive mixer (2.9 to 7.1 GHz) show that a higher performance can be obtained by choosing independently the appropriate termination for input and output frequencies. The experimental results are also useful for the device modelling purposes. >

eng_Latn

Mechanical Aspects Of The Servo Mount Telescope

A tracking telescope designed, built and tested by Perkin-Elmer contains several unique mechanical design solutions that may be applied to other types of equipment with similar design requirements. Three design areas that required special approaches include an azimuth overtravel stop mechanism permitting +190 degrees of motion, a drive system with very low gear-induced errors and zero backlash and a cable wrap system.

OBJECTIVE. The purpose of this study is to evaluate the diagnostic value of in vivo MR spectroscopy (MRS) with semilocalization by adiabatic selective refocusing (semi-LASER MRS) in differentiating...

kor_Hang

Method for measuring frequency response function of vibrating structure in large noise environment

The invention relates to a method for measuring frequency response function of a vibration structure in loud-noise environment, comprising the following steps: a linear swept-frequency signal is adopted as an excitation signal and acceleration response signals of the structure vibration is filtered in a fractional order Fourier domain by fractional order Fourier transformation, so that effect of noise in non-stationary process can be lessened, and measuring accuracy of the frequency response function is improved. Simultaneously, in the method, two groups of experiment signal data are expressed as one group of plural experiment signal data so as to avoid effect of superposition of two signal components, and only one-time filtering is needed to finish noise removal treatment of the two groups of the experiment signal data so as to improve noise removal effect and operating speed.

The purpose of this note is to document some work done as part of the effort directed at designing and simulating a bunch-by-bunch feedback system to control longitudinal coupled bunch instabilities in the B-factory. In particular, I discuss the ring model used in the simulation program developed to study this feedback system. Basically the simulation is a simple tracking program in which the rf drive voltage, the wakefields due to all the bunches, the synchrotron radiation losses, and the kicks applied to the bunches by the bunch-by-bunch feedback are all modelled as voltages applied at a single, discrete point in the ring. The computation of the bunch-by-bunch feedback voltages may of course be done by any desired algorithms. An example and discussion of the general behavior without bunch-by-bunch feedback is given at the end of this report.

eng_Latn

Airgap-less electric motor: A solution for high-torque low-speed applications

Internal Permanent Magnet Motor Design for Electric Vehicle Drive

motor imagery in mental rotation : an fmri study .

eng_Latn

Analytic power factor calculation for vernier machines with concentrated windings

Generic torque-maximizing design methodology of surface permanent-magnet vernier machine

A comparative study of semi-naive Bayes methods in classification learning

eng_Latn

Thinking and practice on school-running orientation of the Newly-established universities-A case study of North China Institute of Science and Technology

The Newly-established universities should be advancing with everlasting innovation by accurate orientation on the basis of their own actual situation.As the only university affiliated to the State Administration of Work Safety,North China Institute of Science and Technology is continuously exploring the development planning,teaching reform,the cultivation of talents and so on,orientating itself towards a modern multidisciplinary university and the first-class training base with the safety science and technology characteristics.

In order to study the unit's movement law,a transient dynamic response model of large hydroelectric machines is established.The model couples the whole unit such as main shaft,generator rotor,turbine runner and various bearing supporting,and involves consistent quality of the unit shaft,gyroscopic inertia and angular inertia.The finite element method and direct numerical integration method are used in the calculation.Through an engineering example,the numerical simulations of time-course response and axes contrail are respectively carried out when the units are acted under transient initial displacements and transient imbalance loads.The calculated results are discussed and analyzed.By means of comparison between calculated and measured data,their results are close.

eng_Latn

Wind turbines Fault Detection and identification using Set-Valued Observers

Research on wind turbine Operations & Maintenance (O&M) procedures is critical to the expansion of Wind Energy Conversion systems (WEC). In order to reduce O&M costs and increase the lifespan of the turbine, we study the application of Set-Valued Observers (SVO) to the problem of Fault Detection and Isolation (FDI) of wind turbines, by taking advantage of the recent advances in SVO theory for model invalidation. A simple wind turbine model is presented along with possible faulty scenarios. The SVO algorithm is built upon these dynamics, taking into account process disturbances, model uncertainty, and measurement noise. The FDI algorithm is assessed within a publicly available benchmark model, using Monte-Carlo simulation runs.

an unmodified (perfect involute) gear pair was compared with that of gears with various profile modifications. relations were found between various profile rnodificatlons and the resulting dynamic loads. the gear's static transmission error, gave a very good estimation of gear dynamic loading. Cor- An effective error, obtained from frequency domain analysis of Design curves generated by dynamic simulation at several profile modlfi- catlons are given for gear systems operated at various applied loads. Optimum profile modifications can then be determined from the design curves to yield a minimum dynamic effect for a gear system and to provide up-to-date knowledge for better gear deslgn. NOMENCLATURE amplitude of ith frequency component

eng_Latn

MANUFACTURING METHODS FOR CONICAL GAS BEARINGS.

Abstract : The development of methods of manufacture of conical gas bearing surfaces on a cylindrical grinding machine is described. The work is principally directed towards reducing the cost of gas bearings for precision gyroscopes, but has application to bearings for other purposes. The results of some early manufacturing trials are discussed and means for further simplifying the manufacturing method are suggested. (Author)

The study of motorcycle's acoustic signal shows that gears noise take a great proportion on the whole acoustic of motorcycle.So how to control the noiseof gears is very helpful for reducing the whole motor's acoustic.This paper discusses the engine matching with transmission system in reason,primary transmission and gear geometry design parameter the mend of tooth body(tooth form tooth direction) how to influence the acoustic of motorcycle.The study shows that the gear transmission System's matching with engine in reason can notable improve the efficiency of motorcycle.In the meaning time the exactly choosing the primary transmission gear geometry design parameter and the mend of primary transmission gear's tooth body can effectively reduce the acoustic of motorcycle.This paper has engineering practice sense.

yue_Hant

HDS does not study the NHH-to-NHH sector of the mailstream.

HDS does not study every part of the mailstream.

HDS studies the NHH-to-NHH sector.

eng_Latn

High Quality Media Streaming over Longdistance Network Using FELIX Experimental Facility

This demo paper presents the FELIX project [1] approach of implementation the "High Quality Media Transmission over long-distance networks" use case. A virtual slice built on demand over European and Japan infrastructure allows to perform the experiments and shows capabilities of the test-bed and its availability for high quality media streaming experiments over a long distance federated network. It is also the first time when the FELIX Control Framework is used for provisioning the SDN resources for the experiments. Two experiments for use case implementation and validation in the FELIX test-bed are proposed and described.

A conceptual design study titled Deep-space Optical Terminals was recently completed for an optical communication ::: technology demonstration from Mars in the 2018 time frame. We report on engineering trades for the entire system, ::: and for individual subsystems including the flight terminal, the ground receiver and the ground transmitter. A point ::: design is described to meet the requirement for greater than 0.25 Gb/s downlink from the nearest distance to Mars of ::: 0.42 AU with a maximum mass and power allocation of 40 kg and 110 W. Furthermore, the concept design addresses ::: link closure at the farthest Mars range of 2.7 AU. Maximum uplink data-rate of 0.3 Mb/s and ranging with 30 cm ::: precision are also addressed.

eng_Latn

Raspberry PI Based OFFLINE MEDIA SERVER

In this research paper, an economically low computing environment using Raspberry Pi zero W model based systems is very Well organized to use computing system in the developing environment. All this work will be done on Linux OS platform and it will help to develop the server using the Raspberry pi. A partition will be made on the SD card which is connected to the Raspberry pi that helps to store the media and work with them Offline. This accommodate up to 50 users to work offline.

A conceptual design study titled Deep-space Optical Terminals was recently completed for an optical communication ::: technology demonstration from Mars in the 2018 time frame. We report on engineering trades for the entire system, ::: and for individual subsystems including the flight terminal, the ground receiver and the ground transmitter. A point ::: design is described to meet the requirement for greater than 0.25 Gb/s downlink from the nearest distance to Mars of ::: 0.42 AU with a maximum mass and power allocation of 40 kg and 110 W. Furthermore, the concept design addresses ::: link closure at the farthest Mars range of 2.7 AU. Maximum uplink data-rate of 0.3 Mb/s and ranging with 30 cm ::: precision are also addressed.

kor_Hang

Number of information and its relation to the cosmological constant resulting from Landauer’s principle

Using a recent published formula for the number of information N that results from Landauer’s principle we obtain an expression for the cosmological constant Λ. Next, assuming the universe as a system of mass M satisfying Landauer’s principle and eliminating its mass M from the given expression for the number of information, we obtain a new expression that agrees with the expression derived by Lloyd. Furthermore, we modify the generalized entropy relation and three equivalent entropy expressions are obtained. Finally, in two different universes the time rate of change of the entropy is calculated. In a flat universe the time rate of the entropy is time independent and depends on fundamental constants of physics.

In this paper, we study the connection and secrecy performance under two-tier cellular network during uplink phase, where both large-scale factor (path propagation loss) and small-scale factor (Nakagami fading) are considered., which are beyond the scope of the existing works. Analytical expressions of network connection and secrecy probabilities are derived., which are validated through Monte Carlo simulations. Numerical results reveal that the theoretical expressions of connection and secrecy probabilities are in good agreement with simulation results. Moreover, simulation results demonstrate that larger $m$ value, which means stronger LOS component, leads to a worse connection performance, but a better secrecy secrecy performance.

eng_Latn

what is the digital divide

The Digital Divide, ICT, and Broadband Internet ICT - Information Communications Technologies. The Digital Divide, or the digital split, is a social issue referring to the differing amount of information between those who have access to the Internet (specially broadband access) and those who do not have access.

Most of the reports about the digital divide center around racial and socio-economic differences (a 2010 study confirmed that household income is the greatest predictor of Internet use). However, for those families in rural areas, access is still the number one issue.

eng_Latn

In this work the degradation of transformer mineral oil in oil-immersed ZnO-based surge arresters has been studied. Three different kinds of ZnO varistors: 1-non-coated, 2-resin-coated and 3-glass-coated, have been used in this study. It can be seen that after long-period high thermal constraints in oil there is a deposited layer on the varistors' surface which call disturb the function of the non-coated varistors. It is also observed that the ZnO varistor and its coating have an influence on degradation of the oil.

In this paper the AC ageing of ZnO-based varistors in transformer oil is studied by an accelerated ageing during 6000 hours. Three kinds of varistors have been studied: 1-non-coated, 2-coated by resin and 3-coated by glass . As well the thermal behaviour of varistors has been studied at different temperatures and voltages. It is found that the coating and environmental conditions have a great influence on the thermal behaviour and the lifetime of varistors. The oil improves their thermal behaviour. As well it improves the I(V) characteristics of the coated varistors while for the naked ones it causes a premature degradation. It is seen that glass could be, from the thermal point of view, a good material for coating the varistors.

Protection equipment based on metal oxide varistors is the most common solution today in the field of low voltage surge arrester applications. All ZnO based varistors are power electronic devices made of n-type semiconductor polycrystalline ceramics, having a high degree of non-linearity of current-voltage dependence. This paper presents an original algorithm applied for dimensioning low voltage varistors, used to protect the inverters located in photovoltaic plants. The algorithm consists in 3 steps, one for computing the height corresponding to the desired voltage, another for the determination of the diameter corresponding to a certain energy/volume absorption capacity, and, a third one which is a sort of safety test for conformity.

eng_Latn

High Physical Parameters Adjustment of the npp+ Solar Cell Structure using PC1D

In this paper, we present a study on the behavior of a polycrystalline silicon cell, specifically the NPP+ structure. The simulation of this structure is done using the PC1D software; this latter allows simulating different structures of photovoltaic cells. The general purpose of the present work is focused on the study of the manner that the cell physical parameters evolve in order to extract the optimal values and then increase the conversion efficiency. The simulation of several parameters such as doping, texturing, textured surface depth, series resistance, shunt resistance, carrier life time and others parameters, make it possible to choose the right parameters values to be used. In this work the efficiency of this studied structure reaches a value of 23%, which represents a good value for this type of cell.

Abstract In this paper, we analyze photometry of V504 Cyg semi-detached binary system. For this purpose, after taking the photometric data, primary and secondary minimum and new epoch were calculated. The period of system is found to be 0.3516916 day. Analysis of light curve was performed by PHOEBE software which uses last version of Wilson–Devinney code. 3D model of the system is worked out using Binary Maker software. The O’Connell effect in the light curve is observed and an accurate model of this system is presented by introducing four spots on the components.

eng_Latn

Influence of defects on solar cell parameters - an experimental study

The influence of defects on solar cell parameters has been determined by fabricating and evaluating small area cells. Arrays of small area (50 mil diameter) solar cells were fabricated on polished polycrystalline silicon substrates. Their I-V characteristics (dark and illuminated), spectral responses and minority carrier diffusion lengths were measured. Selected diodes were laser scanned for photo-response variations. Diodes were defect etched to determine the densities of dislocations, stacking faults, twins, and other grain-boundaries. Dependences of cell parameters on type and density of defects have been evaluated. Application of the results of this analysis to predict large area cell parameters has been experimentally verified. 3 refs.

This paper discusses the factors which could affect the surface quality of zinc strip,such as technology,equipment,environment and operation in production process.Some suggestions to improve the surface quality of zinc strip were given.

eng_Latn

Space and time analysis of irradiation variation across the UK: A 10 year study of solar farm yield

This research offers an understanding of year-to-year and area-to-area variability of PV performance, measured in terms of specific yield (kWh/KWp). This information will assist in grid management.

In the paper, we establish an improvement of Minkowski inequality for sums. Its reverse version is also given.).

eng_Latn

Design and development of a simple solar dehydrator for crop drying

Abstract In this paper, a simple solar collector cum crop drying system is described. The categorical objectives of this paper are (1) to identify a suitable medium capacity solar drying system and (2) to study analytically and experimentally the performance characteristics of this newly fabricated solar drying system. The drying ratio, rehydration ratio, culinary and organoleptic characteristics, of Methi and Bhendi crops were studied and presented in this paper.

This patent relates to the integration of a light display screen with one or more blades of the windmill (LCD, LED, drop banner, ...) (Figure 1) and (Figures 1, 2, 3) , to change the remote display using a remote control and / or computer.

eng_Latn

Alq3 (tris(8-hydroxyquinolinato)aluminium) as a selective n-type contact for FAMAPIBr perovskite solar cells with efficient energy transfer to increase the solar cell photocurrent

We investigated the use of tris(8-hydroxyquinolinato)aluminium, known as Alq3, as a selective contact for electrons in functional FAMAPIBr (formamidinium/methylammonium lead iodide bromide) solar cells. The solar cells with Alq3 interfacial layers show excellent photocurrent upon standard 1 sun illumination (100 mW cm−[email protected] AM G sun simulated light) due to efficient energy transfer from the selective contact layer to the perovskite.

The design of the LTE physical layer (PHY) is heavily influenced by the requirements for high peak transmission rate (100 Mbps DL/50 Mbps UL), spectral efficiency and multiple channel bandwidths (1.25–20 MHz). Unfortunately, the existing WCDMA turbo interleaver does not permit an efficient high throughput implementation. That is why the 3rd Generation Partnership Project (3GPP) has proposed the quadratic polynomial permutation (QPP) interleaver to rectify this situation. In this paper, we will study the performances of QPP interleaver for LTE encoder channel for different configurations of LTE system and we study the effect of LTE channel turbo encoder for the transmission over a wireless multipath channel.

eng_Latn

Study of physical models of a monolayer of a fiber composite by the eddy-current method

An experimental study is made of physical models of a monolayer of a composite consisting of unidirectional strands of conducting carbon fibers separated by layers of a nonconducting binder. In the models, the strands of carbon fibers are replaced by copper conductors of the corresponding diameter which are covered by a thin dielectric film. It is determined that the parameters introduced to describe a rectangular eddy-current transducer are independent of its orientation relative to the direction of the conductors but do depend to a large extent on the reinforcement coefficient. The monolayer is shown to be equivalent to a plate composed of a homogeneous conducting material of equal thickness. The equivalent electrical conductivity of the plate is determined and is found to be more than an order lower than the conductivity of the material of the conductors in the model.

This paper shows that an enhancement in the performance of commercial screen-printed multi-crystalline silicon photovoltaic modules can be achieved via luminescent down-shifting of the incident light. Using fluorescent organic dyes dissolved in the pre-existing poly-ethylene vinyl acetate (EVA) encapsulation layer, an increase in the short-wavelength external quantum efficiency of over 10% absolute, which results in 0.18% absolute higher efficiency, is reported. This approach offers the opportunity for prompt application at production scale, since it neither requires any modification to the module manufacturing process nor does it add to the cost of power generation. Copyright © 2010 John Wiley & Sons, Ltd.

eng_Latn

Empirical battery model characterizing a utility-scale carbon-enhanced VRLA battery

In this paper, the electrical characteristics of a carbon enhanced valve-regulated lead-acid (VRLA) battery from East Penn Manufacturing are investigated and a dynamic model is developed for use in electrical simulations. The electrochemical processes that cause specific dynamic behaviors have been investigated. These processes are explained and a non-linear electric model, which captures the results of some of these electrochemical dynamics, is presented. The method to determine model parameters using experimental data is shown. To verify the battery model, both a pulsed current profile and an arbitrary current profile were applied to the battery and to the battery model and the voltage responses of the two were compared.

In this paper, we present a study on the behavior of a polycrystalline silicon cell, specifically the NPP+ structure. The simulation of this structure is done using the PC1D software; this latter allows simulating different structures of photovoltaic cells. The general purpose of the present work is focused on the study of the manner that the cell physical parameters evolve in order to extract the optimal values and then increase the conversion efficiency. The simulation of several parameters such as doping, texturing, textured surface depth, series resistance, shunt resistance, carrier life time and others parameters, make it possible to choose the right parameters values to be used. In this work the efficiency of this studied structure reaches a value of 23%, which represents a good value for this type of cell.

eng_Latn

design and control of smart dc microgrid for integration of renewable energy sources .

Comprehensive Approach to Modeling and Simulation of Photovoltaic Arrays

Mental health professionals’ attitudes towards mental illness: professional and cultural factors in the INTER NOS study

eng_Latn

Buck converter MPPT control of a photovoltaic system

Modeling and Simulation of Photovoltaic module using MATLAB/Simulink

A comparative study of vein pattern recognition for biometrie authentication

eng_Latn

A Modified P&O-MPPT based on Pythagorean Theorem and CV-MPPT for PV Systems

Energy comparison of MPPT techniques for PV Systems

international computer and information literacy study assessment framework .

eng_Latn

Simulation and Hardware Implementation of Incremental Conductance MPPT With Direct Control Method Using Cuk Converter

Regulation of Photovoltaic Voltage

6LoWPAN: a study on QoS security threats and countermeasures using intrusion detection system approach

eng_Latn

Energetic disorder induced leakage current in organic bulk heterojunction solar cells: comprehending the ultra-high open circuit voltage loss at low temperatures

Organic bulk heterojunction solar cells suffer from a huge, nonmonotonic loss of open-circuit voltage ${V}_{o\phantom{\rule{0}{0ex}}c}$ at low temperatures, which thwarts their practical application. The authors incorporate energetic disorder into a drift-diffusion model to study the ${V}_{o\phantom{\rule{0}{0ex}}c}-T$ relations under various working conditions. In reproducing the empirical observations, they find that disorder-suppressed carrier mobility is the culprit. This work provides a comprehensive picture from the charge-dynamics perspective that will facilitate the engineering of this emerging class of devices.

Different systems act as one of the most promising forms of integration in the urban planning structure. In the process of formation of plans for social and economic development of major cities more often, there is a situation, when the improvement of resources efficiency needs not just a concentration of effort, but also some new and innovative forms of building production organization. It is proposed to establish in Odessa the "Corporate Scientific and Technical Complex of urban planning energy renovation" as an innovative organizational structure which practically uses the accumulated scientific and technical potential for the reconstruction of historic buildings in Odessa in 1820–920 using energy efficiency standards. It is necessary to organize courses in the form of accelerated training for workers of the occupation "master of finishing construction work" specialty "plasterer" for "KNTK GERek" effective functioning.

eng_Latn

what is pvsyst software

PVsyst is a program designed for the study, sizing and data analysis of complete PV systems.It deals with grid-connected, stand-alone, pumping and DC-grid (public transportation) PV systems, and includes extensive meteo and PV systems components databases, as well as general solar energy tools. All comments (0).Vsyst allows you to study and design photovoltaic systems, which use solar panels to convert sunlight into electricity. The program offers three main design options.

Peer-to-peer file-sharing clients are a dime a dozen these days, and many of these applications are quite similar to one another. Pvsyst 6 Activation Code Generator is one more entry into this category of software, and although it works, there’s nothing about it that particularly distinguishes it from the competition.vsyst 6 Activation Code Generator is a tiny clipboard Pvsyst 6 Activation Code Generator, it can be recalled via a Pvsyst 6 Activation Code Generator and supports both bitmap and text clipboards. Pvsyst 6 Activation Code Generator is very unobstrusive and will change the way you think about clipboard operations.

eng_Latn

The paper describes an analysis of rain gauge data to determine an appropriate radius of influence to use for the objective analysis of rainfall over Indian monsoon region. The correlation co-efficient (CC) of rainfall between rain gauges in discrete distance intervals is computed, and the distance at which CC falls to 0.3 is chosen as the radius of rainfall influence. The method is applied for the monthly mean rainfall observations for June, July and August of Indian summer monsoon 2001. The method is also tested for a few case studies in relation to varying geographical and synoptic situations. The study shows that the radius of influence of rainfall over Indian region, in general, is around 200 km, but it has certain day to day variations depending on the prevailing synoptic conditions. The finding of the study is expected to be very useful for the objective analysis of rainfall over Indian region.

A cumulative semivariogram (CSV) method is proposed as an optimum analysis technique for producing gridded fields of meteorological regional variables that are sampled at irregular sites as sparse data. After having discussed the basis of the CSV and its theoretical representations by functional models, the procedure of obtaining weighting functions useful for simple optimum analysis calculations from the CSVs is explained. The experimental CSVs are obtained from monthly rainfall data for northwestern Turkey. Following the interpretation of these experimental CSVs, they are converted into experimental weighting functions necessary for optimum analysis. Comparison of these experimental functions is made on an individual monthly basis with other mathematically simple but geometric weighting functions that are available in the meteorology literature. It is observed that none of the available geometric weighting functions represents completely the regional variation within one month. However, the exp...

Microwave devices with the Rollet parameter (k) less than one can always be made stable by resistive loading. In cases where noise figure or output power is at a premium, the performance of an amplifier can often be enhanced by using a design where k is less than unity thereby avoiding resistive loading. While a simultaneous conjugate match is impossible for such conditionally stable designs, single-sided matching can be achieved. Low-noise and power designs are examples where single-sided matching considerations naturally occur. With single-sided matching and 0 >

eng_Latn

To improve the study on the development of forest fires,the forest fire spreading model was established through the experiments and observation data.Based on the MODIS data,this study obtained data sequence from the enhanced image with fusion technology,then established the spreading and predicting model of forest fires through the integration of Grey Theory.The model has many characters: the process of modeling is simple,data are easy to get,the strong applicability makes it can be used in more fields.By the analysis,half of the predicted relative error was less than 1%,25% was less than 5%,and 25% was 5%-10%.

To improve the precision of gray modeling in forest fire and solve the problem of small date modeling, ER algorithm is proposed. Based on the senior introduced the robust estimation to gray modeling, this method interpolate the modeling date again. The method can achieve small date (3 dates) modeling. This research compared with three calculation methods: least squares method, least squares interpolation method and ER algorithm. According to the fitting precision, least squares method is 10.21%, least squares interpolation method is 1.08% and ER algorithm is 0.00%. That can be obtained by calculating ER algorithm has a good fitting effect.

This publication contains reprint articles for which IEEE does not hold copyright. Full text is not available on IEEE Xplore for these articles.

eng_Latn

Statistical inference for alpha-series process with truncated normal distribution

In this paper we consider an alpha-series process when the distribution of the first occurrence time of an event is assumed to be truncated normal distribution. Firstly, we study several nonparametric inferences including the Least-square estimate (LSE) and the Maximum-likelihood estimate (ML). Some estimators of the parameters in alpha-series process are derived by using the methods referred above. Furthermore, we consider the consistency and asymptotic normality properties of the estimators. Finally, we obtain the simulation results which are calculated over Monte Carlo replications to compare the performance of these variety estimators.

ABSTRACTWe utilize the Internet search data from Google Trends to provide short-term forecasts for the inflow of Japanese tourists to South Korea. We construct the Google variable in a systematic way by combining keywords to minimize mean squared or mean absolute forecasting errors. We augment the Google variable to the standard time-series forecasting models and compare their forecasting accuracies. We find that Google-augmented models perform much better than the standard time-series models in terms of short-term forecasting accuracy. In particular, Google models show better out-of-sample forecasting performance than in-sample forecasting.

eng_Latn

DOA estimation for uncorrelated and coherent signals based on Fourth-order Cumulants

This work aims to estimate the Direction-of-arrival (DOA) of uncorrelated and coherent signals based on Fourth-order Cumulant (FOC) and sparse reconstruction method. Firstly, a subspace method based on FOC matrix is proposed for estimating the DOAs of the uncorrelated signalsthen combining the FOC matrix of the coherent signals with sparse reconstruction theory, we obtain the DOAs information of the coherent signals by mapping a sparse vector. Simulation results are provided to demonstrate that our proposed method is not sensitive to the non-Gaussian signals and colored noise.

Leveraging grid computing technology, i.e. the visualization of distributed computing and data resources such as processing, network bandwidth and storage capacity to create a single system image, we present a Grid Air Quality Forecast System (G-AQFS). The modeling system consists of meteorological and dispersion models coupled in cascade. The computational workflow of the modeling system is defined by means of DAGs (direct acyclic graph). A simple system is presented to manage and schedule the computational grid resources. As case study the system has been applied over Salento area, in the Apulia region (South-eastern Italy), to simulate ground level ozone concentration. Model predictions have been compared with field measurements, with reasonable results.

eng_Latn

Analysis and Forecast of October Rainstorm in Guilin

Statistic is made regarding the October rainstorm process in Guilin during the 42 years from 1960 to 2002 by utilizing the historical synoptic chart information with a view to study the circulation characteristics of its influencing weather system and its evolution law, based on which the forecast mode indices are established according to classification, providing some reference for realtime forecast business of October rainstorm.

The paper sets up a model for forcasting population analgsis,grey system theory and statistics of Benxi population~ between 1990 and 1999.The use of this model proves that the result gained with the methods presented in the paper is nearly in agreement with the fact.

eng_Latn