Miracle-dz/UniFAR-FTUs huggingface dataset:
Analysis of Power-Law Fluid Flow in a Microchannel with Electrokinetic Effects

The pressure driven flow of power-law fluids in microchannels subject to electrokinetic effects is analyzed in this work. The Cauchy momentum equation together with the power-law fluid constitutive equation is used to describe the power-law fluid flow in a slit microchannel with consideration of a body force resulting from the interaction of the charge density in the electrical double layer of the channel and the flow-induced electrokinetic potential. By using an appropriate approximate scheme, an expression for the induced streaming potential is obtained. The velocity profile, volumetric flow rate, apparent viscosity and friction coefficient are analytically evaluated, and the influencing factors including ionic concentration, wall zeta potential, flow behavior index and pressure difference are investigated. It is found that the pseudoplastic fluids are more susceptible to electokinetic effects than the dilatant fluids and then the flow characteristics of the pseudoplastic fluids are found to deviate dra.
Forest attribution using K-NN methods with Landsat 8 imagery and forest field plots

This study presents an approach to integrate Landsat satellite imagery and forest monitoring field plots, to produce forest attribute maps across the state of Victoria, Australia. Over 450 field plots, sampled from a stratified systematic random framework, were measured to characterise woody and non-woody forest attributes. Field plot data were applied in various k-NN procedures using Landsat8 data to map biomass, stems per hectare and species diversity. The study investigated four k-NN distance metrics (Mahalanobis Nearest Neighbour, Most Similar Neighbour, Gradient Nearest Neighbour and Random Forest Nearest Neighbour), as well as five k values representing number of Neighbours used in the prediction model (1, 2, 5, 10 and 20). Model accuracy was assessed in various dimensions, including plot (root mean square difference) and regional level (Area comparison of design-based (plots) vs. model-based (map) estimates). Results are used to provide guidance for implementing k-NN in a large area operational setting.
The starburst ring around the Seyfert nucleus in NGC 7469

High-resolution radio continuum, optical emission line, and optical continuum images of the luminous Seyfert plus circumnuclear starburst hybrid galaxy NGC 7469 are presented. The radio emission from the starburst is largely confined to a ring of diameter 3 arcsec, or 1.0 kpc. There is clear evidence for optical continuum emission and probably optical line emission from the ring. The disks of NGC 1068 and NGC 7469 exhibit a strong similarity in almost all observed properties. Current star formation models can account for the luminous far-infrared emission and the strength of the nonthermal radio emission in NGC 7469, with an expected supernova rate of about one per year. The starburst ring is probably a result of concentration of gas into a ring via resonances between orbital motion and a rotating barlike or ovally distorted potential.
Limit theory for autoregressive‐parameter estimates in an infinite‐variance random walk

We consider the asymptotic behaviour of least-squares and M-estimates of the autoregressive parameter when the process is an infinite-variance random walk. It is shown that certain M -estimates converge faster than least-squares estimates and that they are also asymptotically normal. On considere ľestimation du parametre autoregressif ďun modele AR(1) quand en realite le processus est une marche aleatoire de variance infinie. Le comportement asymptotique des M-estimateurs et des estimateurs de moindres carres est etudie. On demontre que certains M-estimateurs convergent plus rapidement que les estimateurs de moindres carres et qu'ils possedent une loi asymptotique gaussienne.
Interface‐trap generation at ultrathin SiO2 (4–6 nm)‐Si interfaces during negative‐bias temperature aging

This article reports an investigation of the negative‐bias temperature instability in metal‐oxide‐silicon (MOS) systems with gate oxide thickness (Tox) in the range of 4.2–30 nm. The bias temperature aging was performed on p‐type samples with applied negative oxide fields (1.6–5.0 MV/cm) over a temperature range of 150–290 °C. The maximum aging time was 5000 h. The interface‐trap distribution was evaluated by the conductance technique. This time‐consuming method yields reliable results even in ultrathin oxides, if appropriate corrections are made. The interface‐trap generation and the concurrent fixed oxide charge can be expressed by simple empirical expressions. Their characteristic features are the inverse proportionality to oxide thickness (Tox) for the generated interface‐trap density (Nit) and no thickness dependence for the fixed charge generation. A general phenomenological model is proposed to explain these empirical expressions in terms of the diffusion‐reaction chemistry between hydrogenated tri.
Conduction mechanisms in partially crystallized (La,Na)MnO3 films

The electric and magnetoresistive properties of partially crystallized (La,Na)MnO3 films near the paramagnet-ferromagnet transition are investigated. The objects of study are films obtained on polychore substrates by magnetotron sputtering and substrate temperatures 300 and 500°C. The temperature behavior of the electric resistance is analyzed to determine the limits of between the experimental data and the existing theoretical models. A generalized picture of the evolution of conduction mechanisms accompanying a change in temperature and regimes of heat treatment of the samples is constructed. It is shown that a correlation exists between the character of the temperature variation of the magnetoresistance and the change in the conduction mechanisms. The characteristic temperatures which describe the boundaries of the regions in which a definite conduction mechanism dominates are established.
THREE-DIMENSIONAL DYNAMICS OF PROTOSTELLAR EVOLUTION

A three-dimensional finite difference numerical methodology has been developed for self-gravitating, rotating gaseous systems. The fully nonlinear equations for time-varying fluid dynamics are solved by high-speed computer in a cylindrical coordinate system rotating with an instantaneous angular velocity. The time-dependent adiabatic collapse of gravitationally bound, rotating, protostellar clouds is studied for specified uniform and nonuniform initial conditions. Uniform clouds can form axisymmetric, rotating toroidal configurations. If the thermal pressure is high, nonuniform clouds can also collapse to axisymmetric ellipsoids. For low thermal pressures, however, the collapsing cloud is unstable to perturbations. The resulting fragmentation of unstable protostellar clouds is investigated by studying the response of rotating, self-gravitating, equilibrium toroids to nonaxisymmetric perturbations. The detailed evolution of the fragmentation toroid depends upon a nondimensional function of the initial entropy, the total mass in the toroid, the angular velocity of rotation, and the number of perturbation wave-lengths around the circumference of the toroid. For low and intermediate entropies, the configuration develops into corotating components with spiral streamers. In the spiral regions retrograde vortices are observed in some examples. For high levels of entropy, barred spirals can exist as intermediate states of the fragmentation.
Hyperspectral Image Classification Based on Quadratic Fisher's Discriminant Analysis and Multi-class Support Vector Machine

ABSTRACT In this paper, we present a hyperspectral image classification method based on Quadratic Fisher's Discriminant Analysis (QFDA) and Multi-class Support Vector Machine (M-SVM). QFDA has been utilized for feature extraction and dimensionality reduction of a high dimensional hyperspectral image and M-SVM is used for classification purpose. The suggested scheme is compared with Principal Component Analysis (PCA) with SVM scheme and it is observed that the proposed method is superior with respect to classification accuracy. Further, it is observed that QFDA preserves the class discriminatory information in the reduced features as compared to PCA.
Graphs with Monochromatic Complete Subgraphs in Every Edge Coloring

For integers r, $s\geqq 2$, let $\Gamma (r,s)$ be the class of all graphs G with the following property if the edges of G are colored red and blue, then either G contains r mutually adjacent vertices with all connecting lines colored red, or s mutually adjacent vertices with all connecting lines colored blue. By Ramsey’s theorem, $\Gamma (r,s)$ contains all sufficiently large complete graphs. It follows that $\Gamma (r,s)$ contains all graphs with a sufficiently large number of mutually adjacent vertices. We are concerned here with determining the minimum number $f = f(r,s)$ such that $\Gamma (r,s)$ contains a graph G with at most f mutually adjacent vertices. Obviously $f(r,s)\geqq \max (r,s)$. We show constructively that $f(r,s) = \max (r,s)$.
Performance characteristics of the magnetic constrained layer damping

A new class of surface damping treatment is proposed to provide effective means for attenuating undesirable structural vibrations. The proposed treatment relies in its operation on the use of smart damping treatments which consist of integrated arrays of constrained visco-elastic damping layers that are controlled passively by a specially arranged network of permanent magnets. The interaction between the magnets and the visco-elastic layers aims at enhancing the energy dissipation characteristics of the damping treatments. In this manner, it would be possible to manufacture structures that are light in weight which are also capable of meeting strict constraints on structural vibration when subjected to unavoidable disturbances.
Supercontinuum generation in air–silica microstructured fibers with nanosecond and femtosecond pulse pumping

We study the generation of supercontinua in air–silica microstructured fibers by both nanosecond and femtosecond pulse excitation. In the nanosecond experiments, a 300-nm broadband visible continuum was generated in a 1.8-m length of fiber pumped at 532 nm by 0.8-ns pulses from a frequency-doubled passively Q-switched Nd:YAG microchip laser. At this wavelength, the dominant mode excited under the conditions of continuum generation is the LP11 mode, and, with nanosecond pumping, self-phase modulation is negligible and the continuum generation is dominated by the interplay of Raman and parametric effects. The spectral extent of the continuum is well explained by calculations of the parametric gain curves for four-wave mixing about the zero-dispersion wavelength of the LP11 mode. In the femtosecond experiments, an 800-nm broadband visible and near-infrared continuum has been generated in a 1-m length of fiber pumped at 780 nm by 100-fs pulses from a Kerr-lens model-locked Ti:sapphire laser. At this wavelength, excitation and continuum generation occur in the LP01 mode, and the spectral width of the observed continuum is shown to be consistent with the phase-matching bandwidth for parametric processes calculated for this fiber mode. In addition, numerical simulations based on an extended nonlinear Schrodinger equation were used to model supercontinuum generation in the femtosecond regime, with the simulation results reproducing the major features of the experimentally observed spectrum.
Ternary interpolatory subdivision

Ternary Interpolatory Subdivision M.D. van der Walt Department of Mathematics, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa. Thesis: MSc (Math) December 2012 Subdivision is an important and e cient tool for rendering smooth curves and surfaces in computer graphics, by repeatedly applying a subdivision (re ning) scheme to a given set of points. In the literature, attention has been mostly restricted to developing binary subdivision schemes. The primary emphasis of this thesis is on ternary subdivision, and in particular on the interpolatory case. We will derive a symmetric ternary interpolatory subdivision scheme for the rendering of curves, satisfying analogous properties to the Dubuc-Deslauriers binary scheme. Explicit construction methods, as well as a corresponding convergence analysis, will be presented. Graphical illustrations of the results will also be provided. ii Stellenbosch University http://scholar.sun.ac.za
Experimental study of electromagnetic wave propagation in dense random media

Abstract Controlled experiments have been conducted to measure the propagation of synthetically generated pulses in dense random media. The dense media were prepared by embedding spherical dielectric scatterers in a homogeneous background medium: the size and volume fraction of the scatterers were the controlled parameters. A network analyser-based system operating in the frequency domain was used to measure the electric field reflected and transmitted by slab-shaped samples of dense media as the source signal was swept from 26.5 to 40 GHz. An inverse Fourier transform was used to convert the frequency domain response into time domain pulse waveforms. The time domain response was then used to obtain pulse propagation velocity and attenuation in the controlled samples. The experimental results are shown to be in general agreement with dense medium theories.
The role of the potentials in electromagnetism

There are two conflicting views about electromagnetic phenomena. The first is based on the action between stationary and moving particles of electric charge and the second on energy distributions in electric and magnetic fields. The difference between these approaches is seen most clearly in the roles assigned to the potentials. According to the particle view the potentials convey the force from one particle to another, whereas in the field approach the potentials are system parameters related to the field energy. The article compares the two views and concludes that the particle view faces impossible difficulties because it ascribes local significance to quantities which are unobservable and conflicts with the quantum‐mechanical understanding of charge as a statistical distribution.
Interactions among pressure, density, vorticity and their gradients in compressible turbulent channel flows

The interactions among pressure, density, vorticity and their gradients in compressible turbulent channel flows (TCF) are studied using direct numerical simulations (DNS). DNS of three isothermal-wall TCF for Mach number Ma = 0.2, 0.7, and 1.5, respectively are performed using a discontinuous Galerkin method (DGM). The Reynolds numbers of these three cases are ≈2800, based on the bulk velocity, bulk density, half channel width and dynamic viscosity at the wall. A high cross-correlation between density and spanwise vorticity occurs at y+≈4, which is coincident with the peak mean spanwise baroclinicity. The relationship between the spanwise baroclinicity and the correlation is analysed. The difference between the evolution of density and spanwise vorticity very near the wall is discussed. The transport equation for the mean product of density and vorticity fluctuations 〈ρ′ω′i〉 is presented and the distributions of terms in the 〈ρ′ω′z〉 transport equation indicate that the minima and maxima of the profiles are located around y+≈5. The connection between pressure gradients and vorticity fluxes for compressible turbulent flows with variable viscosity has been formulated and verified. High correlations (0.7–1.0) between pressure gradient and vorticity flux are found very close to the wall (y+<5). The correlation coefficients are significantly influenced by Ma and viscosity in this region. Turbulence advection plays an important role in destroying the high correlations between pressure gradient and vorticity flux in the region away from the wall (y+ > 5).
Power robustification of approximately linear tests

Abstract We present a general method of improving the power of linear and approximately linear tests when deviations from a translation family of distributions must be taken into account. This method involves the combination of a linear statistic measuring location and a quadratic statistic measuring change of shape of the underlying distribution. The tests (“funnel tests”) are constructed as certain Bayes tests. In general they gain a sizeable amount of power over the linear tests adapted to the translation family when a change of shape of the underlying distribution occurs, while losing little for translation alternatives (“power robustification”). We introduce the concept of funnel tests in an Gaussian framework first. The effect of power robustification is studied by means of a power function expansion, which applies to a large class of tests sharing a certain invariance property. The funnel tests are characterized by a maximin property over a region defined by a rotational cone. The idea of the const.
Stability analysis of Markovian jumping stochastic Cohen—Grossberg neural networks with discrete and distributed time varying delays

In this paper, the global asymptotic stability problem of Markovian jumping stochastic Cohen—Grossberg neural networks with discrete and distributed time-varying delays (MJSCGNNs) is considered. A novel LMI-based stability criterion is obtained by constructing a new Lyapunov functional to guarantee the asymptotic stability of MJSCGNNs. Our results can be easily verified and they are also less restrictive than previously known criteria and can be applied to Cohen—Grossberg neural networks, recurrent neural networks, and cellular neural networks. Finally, the proposed stability conditions are demonstrated with numerical examples.
Fusion Neutron Flux Monitor for ITER

Neutron flux monitor (NFM) as an important diagnostic sub-system in ITER (international thermonuclear experimental reactor) provides a global neutron source intensity, fusion power and neutron flux in real time. Three types of neutron flux monitor assemblies with different sensitivities and shielding materials have been designed. Through MCNP (Mante-Carlo neutral particle transport code) calculations, this extended system of NFM can detect the neutron flux in a range of 104 n/(cm2? s) to 1014 n/(cm2? s). It is capable of providing accurate neutron yield measurements for all operational modes encountered in the ITER experiments including the in-situ calibration. Combining both the counting mode and Campbelling (MSV; Mean Square Voltage) mode in the signal processing units, the requirement of the dynamic range (107) for these NFMs and time resolution (1 ms) can be met. Based on a uncertainty analysis, the estimated absolute measurement accuracies of the total fusion neutron yield can reach the required 10% level in both the early stage of the DD-phase and the full power DT operation mode. In the advanced DD-phase, the absolute measurement accuracy would be better than 20%.
Study of the SO2 oxidation in solution and its role in atmospheric chemistry

The mechanism of SO2 oxidation in diluted catalytic solutions was studied. It was found that the oxidation stops after a certain pH value is reached. In the same catalytic solutions, the maximum possible SO4− formation is a linear function of the SO2 partial pressure in the air. This mechanism of SO4− formation can account for observed SO4− concentrations in rain, fog, and smog only if some neutralizing cations in the aerosols or traces of NH3 in the air are present. It is shown that in the latter case the system SO2NH3-catalytic solution can explain the main features of SO4− formation in our atmosphere.
Low bit-rate image compression via discrete wavelet transform and classified vector quantization

This paper proposes a high-efficiency low bit-rate image compression algorithm that is based on weighted classified vector quantization (WCVQ) of discrete wavelet transform (DWT) coefficients. The algorithm first does multi-level wavelet decomposition to the original image, and then constructs band-cross vectors along resolution-level-cross high frequency sub-bands respectively in the horizontal, vertical and diagonal three directions that makes the most of the correlation of DWT coefficients among those sub-bands, and then classifies these band-cross vectors into important clustering and unimportant clustering by zero-tree vector and vector energy, and last merges several adjacent unimportant vectors into an unimportant vector block and codes them uniformly, while, applies weighted vector quantization consistent with HVS to the important vectors by progressive constructive clustering (PCC) algorithm that improves the coding efficiency and the reconstructed image quality.
Multiple-Scale Solution of Weakly Nonlinear Elliptic Equations on the Upper Half-Plane

A multiple-scale perturbation method which was previously used to obtain solutions of some weakly nonlinear elliptic Dirichlet boundary-value problems on a semi-infinite strip is here extended to apply to problems on the upper half-plane. This is significant since in potential theory many problems can be solved by mapping to the upper half-plane. Examples are given and the method is applied to the nonlinear problem of a thin airfoil in subsonic flow.
High current injection into SiO2 from Si rich SiO2 films and experimental applications

Chemically vapor deposited (CVD) Si rich SiO2 layers on thermal or CVD SiO2 layers incorporated into metal‐insulator‐semiconductor (MIS) capacitor structures are shown to give very large injected electron currents at low to moderate negative gate voltage biases. The dependence of this injection mechanism on the Si rich SiO2 composition and thickness, temperature, capacitor area, annealing conditions, gate metal (Al or Au), and underlying SiO2 thickness is described. Photocurrent measurements are discussed and are shown to give similar barrier energies as seen for ’’uniform’’ internal photoemission into SiO2. From the experimental electrical and photoelectrical measurements described here and transmission electron microscopy (TEM) and Auger studies of others, a possible model to explain this phenomenon based on electric field distortion caused by a two phase mixture of amorphous Si and SiO2 is presented. Two experimental applications of these structures are described. In one application, an electrically al.