Miracle-dz/UniFAR-FTUs huggingface dataset:
The oscillating drop technique revisited

The oscillating drop technique—in combination with some kind of levitation—is widely used today for the measurement of the surface tension and viscosity of liquids. It is based on Rayleigh's theory for the surface tension driven oscillations of a spherical, force-free, liquid drop. Unfortunately, this ideal case is never realized in practice. Whereas the influence of the levitation field and finite viscosity on the oscillation frequencies has been discussed by several authors, more practical questions related to the observation of these oscillations have not been addressed before and are the topic of this contribution. In particular, the influence of translational or rotational sample movement, and additional effects due to signal processing are discussed. It is hoped that this paper will help to avoid the many pitfalls inherent in the oscillating drop technique and will thus lead to unambiguous and reliable results.
Measurements of X-ray scattering from interstellar grains

The results of an Einstein Observatory imaging proportional counter investigation of the halos produced by the scattering of X-rays from interstellar grains of four compact Galactic (low-latitude) and two extragalactic (high-latitude) X-ray sources are reported. It is found that the intensity of these halos correlates well with the amount of visual extinction and the distance through the Galaxy's dust layer: quantities which measure the column density of grains to a given source. From this result, and from the size and shape of the halos from the Galactic sources, a number of grain parameters are derived in the context of two alternate grain size distributions: the Mathis-Rumpl-Nordsieck (MRN) and the Oort-van de Hulst distributions, either of which is capable of producing the observed halos. Though no single grain size is capable of producing the shapes observed for these halos, a mean size of about 0.1 micron and a number density of about 10 to the -12th grains/cu cm produce the correct halo intensities. From the additional parameters determined from the size and shape of the halos, results concerning the amount of material in grains which are in general agreement with the observed depletion of the elements from the gas phase of the interstellar medium, as well as with the detailed predictions of the MRN size distribution, are found.
Full-vectorial modal analysis for circular optical waveguides based on the multidomain Chebyshev pseudospectral method

What we believe to be a new one-dimensional full-vectorial mode solver for circular waveguides in step-index optical fibers is introduced based on the multidomain Chebyshev pseudospectral method and the perfectly matched layer. The formulations are derived with two transverse components on the radial axis in the cylindrical coordinate system. The electromagnetic fields are expanded inside each homogeneous layer by the Chebyshev basis functions, and then matched rigorously at the radial discontinuities by the interface conditions. The numerical analysis on the guided and leaky modes of the two layer air-clad fiber, hybrid surface plasmon polariton, and Bragg fibers demonstrates the validity and good performance of the present method, which has remarkably high accuracy and fast convergence.
Duct flow with a transverse magnetic field at high Hartmann numbers

Finite element methods can be used for determining the flow in a straight channel under a variety of wall conductivity conditions when a uniform magnetic field is imposed perpendicular to the flow direction. At high Hartmann numbers oscillatory solutions are found unless sufficient points are placed within the Hartmann layers. In some one‐ and two‐dimensional problems it appears that it is adequate to place one or two points within the Hartmann layer to remove the oscillations. Central core values can sometimes be predicted with good accuracy even when the Hartmann layers are not resolved adequately. A nine‐point Gauss point rule has been used to evaluate the stiffness and other matrices for the eight‐node elements. Copyright © 2001 John Wiley & Sons, Ltd.
Sensitivity analysis and design optimization of three‐dimensional non‐linear aeroelastic systems by the adjoint method

We consider the problem of optimizing a non‐linear aeroelastic system in steady‐state conditions, where the structure is represented by a detailed finite element model, and the aerodynamic loads are predicted by the discretization of the non‐linear Euler equations. We present a solution method for this problem that is based on the three‐field formulation of fluid–structure interaction problems, and the adjoint approach for coupled sensitivity analysis. We discuss the computational complexity of the proposed solution method, describe its implementation on parallel processors, and illustrate its computational efficiency with the aeroelastic optimization of various wings. Copyright © 2002 John Wiley & Sons, Ltd.
Integration of the modified Korteweg-de Vries hierarchy with an integral type of source

The modified Korteweg-de Vries hierarchy with an integral type of source (mKdVHWS), which consists of the reduced AKNS eigenvalue problem with r = q and the mKdV hierarchy with an extra term of the integration of a square eigenfunction, is investigated. We propose a method to find the explicit evolution equation for the eigenfunction of the auxiliary linear problems of the mKdVHWS. Then we determine the evolution equations of scattering data corresponding to the mKdVHWS, and solve the equation in the mKdVHWS by inverse scattering transformation.
Thermal sealing of blood vessels using infrared lasers

Suture ligation of blood vessels during surgery can be time-consuming and skill-intensive. Energy-based, electrosurgical and ultrasonic devices have recently replaced sutures for many surgical procedures, providing rapid hemostasis during surgery. However, these devices have the potential to create large collateral zones of thermal damage and tissue necrosis. This study explores infrared (IR) lasers as an alternative technology for rapid and precise thermal coagulation and sealing of blood vessels. Eight near-IR lasers (808, 980, 1075, 1470, 1550, 1850- 1880, 1908, and 2120 nm) were tested. Preliminary studies were performed using fresh porcine renal vessels, ex vivo, with diameters of 1-6 mm, compressed to a thickness of 0.4 mm. A linear beam profile was then applied normal to the vessel for narrow, full-width thermal coagulation. Laser irradiation time was 5 s. Vessel burst pressure measurements were used to determine seal strength. The 1470 nm laser wavelength sealed a wide range of vessel diameters from 1-6 mm. Other lasers (1550, 1850-1880, and 1908 nm) also sealed vessels, but were limited by suboptimal seal pressures, excessive charring, and/or limited power output preventing treatment of large vessels.
Plasmon dispersion and damping in electrically isolated two-dimensional charge sheets

Using high-resolution reflection electron-energy-loss spectroscopy (HREELS), we compare experimental results for the wave-vector-dependent behavior of plasmons in a graphene sheet on SiC(0001) with that due to a filled band of surface states on semiconducting silicon. There are significant differences in behavior between the two systems and the behavior predicted for a classical two-dimensional sheet of electrons. In particular, the damping increases with wave vector independent of any obvious inelastic scattering channel. The results illustrate the importance of finite-momentum, nonlocal potential effects for the dynamical behavior of electrically isolated charge sheets.
On Forward-in-Time Differencing for Fluids: an Eulerian/Semi-Lagrangian Non-Hydrostatic Model for Stratified Flows

ABSTRACT In this paper, we describe a non-hydrostatic anelastic model for simulating stratified flows in terrain-following coordinates. The model is based solely on non-oscillatory forward-in-rime integration schemes, and our primary goal is to demonstrate the utility of such methods for modelling small-scale atmospheric dynamics. We use the formal similarity of the Eulerian and semi-Lagrangian equations of two-time-level approximations to construct a unified model that readily allows selection of either formulation. We apply the model to two test problems of stratified flows past isolated obstacles. We use these tests to validate the forward-in-time approach against a traditional centred-in-time-and-space Eulerian model, and to discuss the relative accuracy and efficiency of the two formulations of our model. One problem illustrates the efficacy of flux-form Eulerian methods, while the other demonstrates strengths of the semi-Lagrangian approach.
A new method of 3D reconstruction using the point cloud and distance images of laser radar

As for the characteristic of the data acquired by laser radar and the three dimentional point cloud in disorder, and by combining the abundant in three dimentional information of point cloud with the specific textural information of distance images, we raised a new algorithm on the reconstruction of laser radar based on simplified point cloud and distance images. In this article, we take advantage of the feature that Delaunay triangulation have to raise a simplified algorithm to achieve the model network. In this algorithm, at first we build up the Delaunay triangulation, then comfirm the vector by calculating the distance that every vertex in the network from the adjacency vertex, and then calculate the intersection angle that the vector with triangle around; at the same time set the angular threshold in order to generate the new Delaunay triangulation. Experimental results show that this algorithm can accomplish the simplication of triangulation without affecting the accuracy of the modeling, along with the detailed, textural and shading information, we can achieve 3D reconstruction of the target images effectively.
Environmental pollution, the public sector and economic growth: A comparison of different scenarios

In this paper we present an endogenous growth model with productive public capital and environmental pollution. Emissions result from production and raise the stock of pollution that negatively affects the utility of the household. The government levies an income tax and a tax on emissions and uses its revenues for public investment and for abatement of pollution. This paper studies the structure of the model assuming three different scenarios and analyzes how the latter affects the balanced growth rate of the economy and welfare. The first scenario posits that abatement is set such that the stock of pollution is constant, in the second scenario pollution declines over time, and in the third scenario, pollution grows at the same positive rate as the economic variables. Copyright © 2010 John Wiley & Sons, Ltd.
Logarithmic convergence rates of the iteratively regularized Gauss - Newton method for an inverse potential and an inverse scattering problem

Convergence and logarithmic convergence rates of the iteratively regularized Gauss - Newton method in a Hilbert space setting are proven provided a logarithmic source condition is satisfied. This method is applied to an inverse potential and an inverse scattering problem, and the source condition is interpreted as a smoothness condition in terms of Sobolev spaces for the case where the domain is a circle. Numerical experiments yield convergence and convergence rates of the form expected by our general convergence theorem.
The Application of Wavelet Transform in Image Dispose

The features of wavelet transform is firstly introduced in this paper, then the directional wavelet is introduced to pick up image characteristic, finally, the experimental results of directional wavelet used in characteristic identification of character-figure is given, it proves this characteristics puck-up method has good local direction characteristics, this function make it has good identification capacity for typical noise of character: stroke missed, stroke break, mechanism twitter, stroke conglutination, so it very useful for character identification.
Theoretical analysis and modeling of light trapping in high efficicency GaAs nanowire array solar cells

A rigorous analysis and design of efficient light trapping for Gallium arsenide nanowire array (NWA) solar cells is presented. The influence of the geometric parameters on the optical absorption of NWA has been thoroughly analyzed by using finite-difference time-domain simulations. It is found that the NWA have superior absorption characteristic over thin-film due to the combined effects of intrinsic anti-reflection and efficient excitation of resonant modes. Optimized optical designs are obtained by maximizing the ultimate photocurrent under AM1.5G illumination. The photogeneration profiles under optimized conditions are incorporated into electrical modeling, in which the core-shell NWA solar cells exhibit 22.3% efficiency.
Optical properties of hexagonal GaN

Single-crystalline hexagonal GaN (α-GaN) films have been grown on (0001) sapphire substrates by metalorganic chemical vapor deposition at 1040 °C. The complex dielectric functions, e(E)=e1(E)+ie2(E), of the epitaxial films have been measured by spectroscopic ellipsometry (SE) for E⊥c in the region between 1.5 and 5.0 eV at room temperature. Previously published ultraviolet SE spectra of α-GaN are examined by considering the effects of surface roughness using an analysis based on an effective medium model. Ex situ atomic force microscopy is used to assess independently surface flatness. By mathematically removing the effects of surface roughness, the most reliable e(E) values for α-GaN are presented in the 1.25–10 eV photon–energy range. Theoretical dispersion analysis suggests that the E0 structure could be characterized by a three-dimensional M0 critical point and the E1α (α=A,B,C) structures by two-dimensional M1 critical points. To facilitate design of various optoelectronic devices, dielectric-functio.
The superposition of alternating on-off flows and a fluid model

An on{off process is a 0{1 process (cid:24) t in which consecutive 0-periods (cid:148) T 0 ;n (cid:149) alternate with 1-periods (cid:148) T 1 ;n (cid:149) (cid:144) n D 1 ; 2 ;::: (cid:145) . The on and off time sequences are independent, each consisting of i.i. d. r.v. s. By the superposed (cid:13)ow, we mean the process Z t D P N‘ D 1 r ‘ (cid:24) ‘ t , where r ‘ > 0 and (cid:148) (cid:24) 1 t (cid:149) ;:::; (cid:148) (cid:24) N t (cid:149) are independent on{off (cid:13)ows. The process (cid:24) ‘t is not Markovian; however, with the age component (cid:17) ‘ t , the process w ‘ t D (cid:144) (cid:24) ‘ t ;(cid:17) ‘ t (cid:145) is a piecewise deter- ministic Markov process. In this paper we study the buffer content process for which the tail of its steady-state distribution 9 (cid:144) b (cid:145) ful(cid:12)lls inequality C (cid:0) e (cid:0) (cid:13)b (cid:20) 9 (cid:144) b (cid:145) (cid:20) C C e (cid:0) (cid:13)b , where (cid:13) > 0 is the solution of some basic non- linear system of equations.
Robust model tracking control for a class of nonlinear plants

We propose a new model-following control scheme for a class of nonlinear plants. The feedback control signal is a continuous function of all its arguments. It is shown that this scheme guarantees that tracking error remains bounded and tends to a neighborhood of the origin with a rate not inferior to an exponential one; furthermore, it allows the designer to arbitrarily prescribe the rate of convergence and the size of the set of ultimate boundedness.
Embedded surfaces in four-manifolds, branched covers, and SO(3)-invariants

One of the outstanding problems in four-dimensional topology is to find the minimal genus of an oriented smoothly embedded surface representing a given homology class in a smooth four-manifold. For an arbitrary homology class in an arbitrary smooth manifold not even a conjectural lower bound is known. However, for the classes represented by smooth algebraic curves in (simply connected) algebraic surfaces, it is possible that the genus of the algebraic curve, given by the adjunction formula is the minimal genus. This is usually called the (generalized) Thom conjecture. It is mentioned in Kirby's problem list [11] as Problem 4·36.
Distinction between deterministic and random beam fanning in photorefractive materials

Photorefractive beam fanning is observed in diffusion dominated materials such as barium titanate and photovoltaic materials such as lithium niobate. Beam fanning in barium titanate has been extensively used to generate self-pumped phase conjugation. Beam fanning patterns in lithium niobate have been utilized in characterization of the photorefractive material. Two types of beam fanning have been shown to exist: deterministic beam fanning which results from the shape of the beam, and random beam fanning which originates from scattering of the incident beam from the surface and bulk of the crystal. In this paper, we report on a careful analysis of both kinds of fanning, using a focused Gaussian beam of varying waists and incorporating randomness in amplitude and phase at the surface and through the bulk of the photorefractive material. We show that in photorefractive barium titanate, deterministic beam fanning, characterized by a deflection of the main lobe of the beam in the far field and an additional sideband, may dominate over waist sizes in the tens of microns, whereas random beam fanning, characterized by multiple lobes, dominate over waist sizes larger than tens of microns.
A criterion for cellularity in a topological 4-manifold

We give a necessary and sufficient condition for a compact set in the interior of a topological 4-manifold to be cellular. This generalizes D. R. McMillan's cellularity criterion for higher dimensions to dimension four. Let X be a compact set in the interior of a topological n-manifold with (possibly empty) boundary M. We say that X is cellular in M if there is a sequence of n-cells Ci C int M such that X = nool Ci and Cji c int Ci for every i. The concept of cellularity has been one of the most important in modern geometric topology ever since it was introduced by M. Brown [1] in 1960 (e.g., see [5]). In 1964, D. R. McMillan, Jr. [6] proved a beautifully simple criterion for a compact set in the interior of a PL n-manifold (n > 5): A UV? -compactum X in the interior of a PL n-manifold (n > 5) M is cellular in M if and only if it satisfies the following cellularity criterion (CC): 0 (CC) For every neighborhood U C M of X there is a neighborhood V C (CC) U of X such that every loop in V X is null-homotopic in U X. (A compact set X in an ANR Y has the UV? -property [5] if for every neighborhood U C Y of X there is a neighborhood V C U such that V is contractible in U.) By [4], McMillan's result now holds also for TOP n-manifolds (n > 5). With a special proviso concerning possible fake cubes, McMillan's criterion holds in dimension three as well [6]. Finally, for n < 2, the Phragmen-Brouwer theorem shows that X C int Mn is cellular if and only if X has property uv? (the homology version of UV? [5]) [9]. We extend McMillan's criterion to dimension four: THEOREM. Suppose that X is a UV? -compactum in the interior of a topological 4-manifold with boundary M4. Then X is cellular in M4 if and only if X satisfies the cellularity criterion (CC). PROOF. It is clear that the condition CC is necessary for cellularity of X in M4 [1] so we only prove its sufficiency. Since X is a UV? -compactum, given a neighborhood U c int M4 there is an open set V C U, containing X, and such that V is contractible in U. Therefore V is orientable and the classifying map for the topological microbundle on V lifts to BO(4). ,BO(4)
Thin-film Bi-Sr-Ca-Cu-O high-temperature superconductors using pulsed laser evaporation from sintered disks

Films of the high‐temperature superconductor in the Bi‐Sr‐Ca‐Cu‐O system were deposited by pulsed laser evaporation from a ceramic disk. Films deposited onto (100) MgO show x‐ray diffraction patterns characteristic of c‐axis textured Bi2(Sr,Ca,Bi)3Cu2Ox phase following annealing for 10 min at 850 °C in 20% O2‐80% N2. These textured films have zero resistance at 78 K and show resistance drops near 110 K. The effects of the annealing environment on the electrical and structural properties are presented.
Stability of piecewise rotations and affine maps

We study the dynamics of non-ergodic piecewise linear maps under perturbations. We show that for the class of maps that can be conjugated to piecewise rotations, sets following the same codings change Hausdorff continuously under perturbations of the map. It follows that the size f of the set of points that iterate arbitrarily close to discontinuities changes semi-continuously under perturbations. This implies f changes continuously on a dense Gδ set and this supports a stronger numerical result by Ashwin, Chambers and Petkov, that the measure of such a set changes continuously. The main tools used in the paper include properties of convexity and symbolic dynamics. The scope of our work includes maps that appear in digital filters. A digital filter is a type of signal processing algorithm (software) used for filtering a digital signal.
Bubble domains in magnetostatically coupled garnet films

Bubble domains have been observed in five composite garnet structures consisting of two epitaxial magnetic layers separated by a layer of nonmagnetic garnet. The static and ``ordering'' properties of the domains are described and the arrangement of the overlying domains is discussed as a function of bias field. It is shown qualitatively that the strength of the magnetostatic interaction between the two magnetic layers can be changed considerably by varying the relative film thicknesses in the composites.
Time-varying neuro-fuzzy model using probability density function techniques for batch processes

A time-varying neuro-fuzzy model (TNFM) based on the probability density function (PDF) technique is proposed in this paper. It is able to describe the characteristics of repetition of batch process by using the input–output data information of batch axes and time axes separately. More specifically, the parameters of time-varying neuro-fuzzy are functions of time during one batch, while it can be looked as uniform values from the viewpoint of batch to batch. Moreover, it converts the modelling problem into a PDF shape of modelling error control problem. The adjustable parameters of TNFM are updated to make the PDF shape of modelling error to follow the targeted PDF. As a result, the proposed method not only describes the characteristics of repetition of batch process, but also guarantees the generalization and robustness, especially when uncertainty and disturbance exist. Lastly, to verify the effectiveness of the proposed identification method, it is applied to a benchmark batch process, in comparison with the traditional identification algorithm based on minimum variance and zero mean.
An Example of the Value of Strong Climatological Signals in Tropical Cyclone Track Forecasting: Hurricane Ivan (2004)

Abstract Since 1970, tropical cyclone (TC) track forecasts have improved steadily in the Atlantic basin. This improvement has been linked primarily to advances in numerical weather prediction (NWP) models. Concurrently, with few exceptions, the development and operational use of statistical track prediction schemes have experienced a relative decline. Statistical schemes provided the most accurate TC track forecasts until approximately the late 1980s. In this note, it is shown that increased reliance on the global NWP models does not always guarantee the best forecast. Here, Hurricane Ivan is used from the 2004 Atlantic TC season as a classical example, and reminder, of how strong climatological signals still can add substantial value to TC track forecasts, in the form of improved accuracy and increased timeliness at minimal computational cost. In an 8-day period in early September 2004, Hurricane Ivan was repeatedly, and incorrectly, forecast by 12 operational NWP models to move with a significant northw.