Miracle-dz/UniFAR-FTUs huggingface dataset:
Algebraic design of anisochronic controllers for time delay systems

The prime objective of the paper is to overcome the conventional restriction to the field of rational functions as far as the algebraic design of control systems is concerned. By adopting the affine parameterization approach from algebraic control synthesis for the controllers given as the so-called RQ-meromorphic functions an algebraic solution to time-delay system control design is opened where neither an introduction of 2D transfer functions nor the assumption of commensurate delays is needed. The proposed design results in controllers combining both the integrators and delayers due to this property referred to as anisochronic.
Preparation and evaluation of formalized bivalent Newcastle and Salmonella poultry vaccine

This study was conducted to prepare and evaluate the potency of different inactivated vaccine formulations that protect chickens against Salmonella Enteritidis and Newcastle disease virus using Montanide as adjuvant. Protection and the humoral immune response of prepared vaccines against Salmonella Enteritidis and Newcastle disease virus was evaluated and compared to imported vaccine. In this study, different formulae of Salmonella Enteritidis and Newcastle disease vaccines were prepared and compared with the imported one by measuring the antibody titer against Newcastle disease virus by hemagglutination inhibition test and the antibody titer against Salmonella Enteritidis using Enzyme Linked Immunosorbent Assay. On the other hand, the protection percentages against Newcastle disease and Salmonella Enteritidis were recorded to determine the best effective formula. The highest hemagglutination inhibition antibody level against NDV at first week was recorded for the prepared combined Newcastle disease and Salmonella Enteritidis vaccine (4.2 log 2 ) followed by the prepared monovalent Newcastle disease (3.4 log 2 ); the lowest antibody level (3.1 log 2 ) was obtained with the imported vaccine. A gradual increase was observed in all groups to 7.1 log 2 , 6.8 log 2 and 6.4 log 2 at fourth week post vaccination, respectively. The antibody titer against Salmonella Enteritidis was 552 for the prepared combined Salmonella Enteritidis and Newcastle disease, followed by the prepared monovalent Salmonella Enteritidis (477) at first week post vaccination; the antibody titer obtained for the imported vaccine was 477. There was a gradual increase to 1456, 1406 and 1130 at fourth week post vaccination, respectively. Prepared combined vaccines gave the highest protection percentage, followed by prepared monovalent types and finally imported vaccines. Vaccination by the prepared combined Salmonella Enteritidis and Newcastle disease vaccine may be a way to increase the resistance of birds to S almonella and Newcastle and to decrease the shedding rate.
The effect of Newtonian cooling on vertically propagating magneto-acoustic waves in a thermally conducting isothermal atmosphere (II)

In this article, we examine reflection, dissipation and attenuation of vertically propagating waves in an isothermal atmosphere under the combined effect of Newtonian cooling, thermal conduction and viscosity with a weak horizontal magnetic field. We consider the case in which the combined effect of viscosity and magnetic field is dominated by that of the thermal conduction and for small values of the Newtonian parameter. As a result, the atmosphere can be divided into three distinct regions that are connected by two transition regions. The lower and middle regions are connected by a semi-transparent barrier and the middle and upper regions are connected by an absorbing and reflecting barrier. In the connecting barriers the reflection and transmission of the waves takes place. The presence of Newtonian cooling effects on the adiabatic region, produces attenuation in the amplitudes of the waves and reduces the energy absorption in the transition regions. The reflection coefficient is determined in the lower and middle regions and the results are discussed in the context of the heating of the solar atmosphere.
Recursive second order convergence method for natural frequencies and modes when using dynamic stiffness matrices

When exact dynamic stiffness matrices are used to compute natural frequencies and vibration modes for skeletal and certain other structures, a challenging transcendental eigenvalue problem results. The present paper presents a newly developed, mathematically elegant and computationally efficient method for accurate and reliable computation of both natural frequencies and vibration modes. The method can also be applied to buckling problems. The transcendental eigenvalue problem is first reduced to a generalized linear eigenvalue problem by using Newton's method in the vicinity of an exact natural frequency identified by the Wittrick–Williams algorithm. Then the generalized linear eigenvalue problem is effectively solved by using a standard inverse iteration or subspace iteration method. The recursive use of the Newton method employing the Wittrick–Williams algorithm to guide and guard each Newton correction gives secure second order convergence on both natural frequencies and mode vectors. The second order mode accuracy is a major advantage over earlier transcendental eigenvalue solution methods, which typically give modes of much lower accuracy than that of the natural frequencies. The excellent performance of the method is demonstrated by numerical examples, including some demanding problems, e.g. with coincident natural frequencies, with rigid body motions and large‐scale structures. Copyright © 2003 John Wiley & Sons, Ltd.
Class I methanol masers: masers with extended green objects

We have compared the results of a number of published class I methanol maser surveys with the catalogue of high-mass outflow candidates identified from the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire survey (known as extended green objects or EGOs). We find class I methanol masers associated with approximately two-thirds of EGOs. Although the association between outflows and class I methanol masers has long been postulated on the basis of detailed studies of a small number of sources, this result demonstrates the relationship for the first time on a statistical basis. Despite the publication of a number of searches for class I methanol masers, a close physical association with another astrophysical object which could be targeted for the search is still lacking. The close association between class I methanol masers and EGOs therefore provides a large catalogue of candidate sources, most of which have not previously been searched for class I methanol masers. Interstellar masers and outflows have both been proposed to trace an evolutionary sequence for high-mass star formation, therefore a better understanding of the relationship between class I methanol masers and outflow offers the potential for comparison and amalgamation of these two evolutionary sequences.
Uncertainty Analysis of Radiative Heating Predictions for Titan Entry

The objective of this study was to investigate the uncertainty in shock layer radiative heating predictions on the surface of a hypersonic inflatable aerodynamic decelerator during Titan entry at peak radiative heating conditions. Computational fluid dynamics simulations of planetary entry flows and radiative heating predictions possess a significant amount of uncertainty due to the complexity of the flow physics and the difficulty in obtaining accurate experimental results of molecular-level phenomena. Sources of uncertainty considered include flowfield chemical rate models, molecular band emission, and the excitation/deexcitation rates of molecules modeled with a non-Boltzmann approach. Because of the computational cost of the numerical models, uncertainty quantification was performed with a surrogate modeling approach based on a sparse approximation of the point-collocation nonintrusive polynomial chaos expansion. Accurate uncertainty results were obtained with only 500 evaluations of the computational.
Short period, high field cryogenic undulator for extreme performance x-ray free electron lasers

Short period, high field undulators can enable short wavelength free electron lasers (FELs) at low beam energy, with decreased gain length, thus allowing much more compact and less costly FEL systems. We describe an ongoing initiative to develop such an undulator based on an approach that utilizes novel cryogenic materials. While this effort was begun in the context of extending the photon energy regime of a laser-plasma accelerator based electron source, we consider here implications of its application to sub-fs scenarios in which more conventional injectors are employed. The use of such low-charge, ultrashort beams, which has recently been proposed as a method of obtaining single-spike performance in x-ray FELs, is seen in simulation to give unprecedented beam brightness. This brightness, when considered in tandem with short wavelength, high field undulators, enables extremely high performance FELs. Two examples discussed in this paper illustrate this point well. The first is the use of the SPARX injector at 2.1 GeV with 1 pC of charge to give 8 GW peak power in a single spike at 6.5 \AA{} with a photon beam peak brightness greater than ${10}^{35}\text{ }\text{ }\mathrm{photons}/(\mathrm{s}\text{ }{\mathrm{mm}}^{2}\text{ }{\mathrm{mrad}}^{2}\text{ }\text{ }0.1%\text{ }\text{ }\mathrm{BW})$, which will also reach LCLS wavelengths on the 5th harmonic. The second is the exploitation of the LCLS injector with 0.25 pC, 150 as pulses to lase at 1.5 \AA{} using only 4.5 GeV energy; beyond this possibility, we present start-to-end simulations of lasing at unprecedented short wavelength, 0.15 \AA{}, using 13.65 GeV LCLS design energy.
A Second-Order Godunov Method for Wave Problems in Coupled Solid-Water-Gas Systems

We present a second-order Godunov method for computing unsteady, one-dimensional wave problems with fracture and cavitation in coupled solid? water? gas systems. The method employs a hydro-elasto-plastic body, the Tait equation, and the ideal gas law for solid, water, and gaseous phases, respectively, and models both fractures and cavities as vacuum zones with distinct borders. The numerical approach utilizes a Lagrangian formulation in conjunction with local solid? water? gas-vacuum Riemann problems, which have unique solutions and can be solved efficiently. The various phases are treated in a unified manner and no supplementary interface conditions are necessary for tracking material boundaries. Calculations are carried out for Riemann problems, wave propagation and reflection in a water? rock? air system, and spallation and cavitation in an explosion? steel? water? gas system. It is shown that the Godunov method has high resolution for shocks and phase interfaces, clearly resolves elastic and plastic waves, and successfully describes onset and propagation of fracture and cavitation zones.
Electron lifetimes from narrowband wave‐particle interactions within the plasmasphere

This paper is devoted to the systematic study of electron lifetimes from narrowband wave‐particle interactions within the plasmasphere. It relies on a new formulation of the bounce‐averaged quasi‐linear pitch angle diffusion coefficients parameterized by a single frequency, ω, and wave normal angle, θ. We first show that the diffusion coefficients scale with ω/Ωce, where Ωce is the equatorial electron gyrofrequency, and that maximal pitch angle diffusion occurs along the line α0 = π/2–θ, where α0 is the equatorial pitch angle. Lifetimes are computed for L shell values in the range [1.5, 3.5] and energies, E, in the range [0.1, 6] MeV as a function of frequency and wave normal angle. The maximal pitch angle associated with a given lifetime is also given, revealing the frequencies that are able to scatter nearly equatorial pitch angle particles. The lifetimes are relatively independent of frequency and wave normal angle after taking into consideration the scaling law, with a weak dependence on wave normal angle up to 60–70°, increasing to infinity as the wave normal angle approaches the resonance cone. We identify regions in the (L, E) plane in which a single wave type (hiss, VLF transmitters, or lightning‐generated waves) is dominant relative to the others. We find that VLF waves dominate the lifetime for 0.2–0.4 MeV at L ~ 2 and for 0.5–0.8 MeV at L ~ 1.5, while hiss dominates the lifetime for 2–3 MeV at L = 3–3.5. The influence of lightning‐generated waves is always mixed with the other two and cannot be easily differentiated. Limitations of the method for addressing effects due to restricted latitude or pitch angle domains are also discussed. Finally, for each (L, E) we search for the minimum lifetime and find that the optimal frequency that produces this lifetime increases as L diminishes. Restricting the search to very oblique waves, which could be emitted during the Demonstration and Science Experiments satellite mission, we find that the optimal frequency is always close to 0.16Ωce.
The AAstrom-Wittenmark self-tuning regulator revisited and ELS-based adaptive trackers

Although considerable progress has been made in stochastic adaptive control, the problem concerning the convergence of the original self-tuning regulator proposed by K.J. AAstrom and B. Wittenmark (1973) is still open. Since it is attractive in theory and important in applications, this problem is examined and a rigorous proof of its stability and optimality is given. Related problems such as convergence of the extended-least-squares (ELS)-based adaptive tracker are also considered. >
Sensing the soot load in automotive diesel particulate filters by microwave methods

Modern vehicles with diesel engines need to be equipped with particulate filters (DPFs) to meet today's and tomorrow's stringent emission regulations. Such filters must be regenerated on a regular basis to burn off the soot adsorbed in the course of time. As the regeneration processes consume fuel, they must be kept to the bare minimum which requires a detailed knowledge of the actual soot load in the filter. We have investigated if the soot load can be determined in situ by the cavity perturbation method at operating frequencies in the low GHz range. We will show that, indeed, current microwave technology as used, for instance, in cellular phones is capable of detecting the soot load in a diesel particulate filter. Experimentally observed sensitivities of cavity resonance frequencies to soot load (adsorbed mass) were as high as 3 MHz g−1. This contribution reports on the measurement approach, experimental results obtained in industrial dynamometer test benches and the conclusions to be drawn from the results.
Stable azimuthal stationary state in quintic nonlinear optical media

We analyze the structure of the first azimuthal stationary state for a nonlinear medium presenting simultaneously a cubic (focusing) and a quintic (defocusing) dependence with the light intensity in the refractive index. This solution takes the form of a dark vortex of light hosted in a compact light beam. The existence of these modes is guaranteed if the flux exceeds a certain minimum threshold and if the modes are extremely stable for fluxes larger than a critical value that we calculated. We verified the robust nature of this solution inducing internal oscillations by an initial phase chirp. Using the variational method, we obtain an approximate picture for the beam internal dynamics. We also studied numerically the interactions between two near-vortex solutions, finding that for a wide combination of beam parameters they show elastic collisions.
High resolution H band imaging polarimetry of IRC +10216. The obscured location of the central star

We have carried out an H band imaging polarimetry of an evolved AGB star IRC + 10216 using CIAO and AO on the Subaru telescope. Our polarimetric images show NE-S bipolar lobes, a NW lobe, a discrete NW arc with similar to 4. '' 2 radius and two new features of a fan-like shape at the SE and of an elliptic shape at the NW with small polarizations (P < 4%) near the intensity peak. The polarization vectors in the NE-S lobes and the NW lobe have a centrosymmetric pattern centered at the position of the illumination source (the central star). The illumination source is located at (+0.'' 25, -0.'' 065) from the intensity peak between the SE fan and the NW ellipse. The polarization vectors between these two features are aligned along a line across them. We interpret that the appearance of the SE fan and the NW ellipse reflects a sudden increase of the mass loss rate that likely initiated the formation of an edge-on dust torus. This sudden mass loss increase probably began about a half century ago.
What Monte Carlo methods cannot do

Abstract Although extremely flexible and obviously useful for many risk assessment problems, Monte Carlo methods have four significant limitations that risk analysts should keep in mind. (1) Like most methods based on probability theory, Monte Carlo methods are data‐intensive. Consequently, they usually cannot produce results unless a considerable body of empirical information has been collected, or unless the analyst is willing to make several assumptions in the place of such empirical information. (2) Although appropriate for handling variability and stochasticity, Monte Carlo methods cannot be used to propagate partial ignorance under any frequentist interpretation of probability. (3) Monte Carlo methods cannot be used to conclude that exceedance risks are no larger than a particular level. (4) Finally, Monte Carlo methods cannot be used to effect deconvolutions to solve backcalculation problems such as often arise in remediation planning. This paper reviews a series of 10 exemplar problems in risk ana.
Numerical Solutions of Forced Convection Boundary Layer Flow on a Horizontal Circular Cylinder with Newtonian Heating

This study considers the steady forced convection boundary layer flow over a horizontal circular cylinder, generated by Newtonian heating in which the heat transfer from the surface is proportional to the local surface temperature. The governing boundary layer equations are first transformed into a system of nondimensional equations via the non-dimensional variables, and then into nonsimilar equations before they are solved numerically using a numerical scheme known as the Keller box method. Numerical solutions are obtained for the skin friction coefficient and the local wall temperature as well as the velocity and temperature profiles.
Solute transport through a deforming porous medium

Solute transport through a porous medium is typically modelled assuming the porous medium is rigid. However, many applications exist where the porous medium is deforming, including, municipal landfill liners, mine tailings dams, and land subsidence. In this paper, mass balance laws are used to derive the flow and transport equations for a deforming porous medium. The equations are derived in both spatial and material co‐ordinate systems. Solute transport through an engineered landfill liner is used as an illustrative example to show the differences between the theory for a rigid porous medium, and small and large deformation analysis of a deforming porous medium. It is found that the large deformation model produces shorter solute breakthrough times, followed by the small deformation model, and then the rigid porous medium model. It is also found that it is important to include spatial and temporal void ratio variations in the large deformation analysis. It is shown that a non‐linear large deformation model may greatly reduce the solute breakthrough time, compared to a standard transport analysis typically employed by environmental engineers. Copyright © 2002 John Wiley & Sons, Ltd.
Wave-power absorption by systems of oscillating surface pressure distributions

Some general results are derived for the efficiency of energy absorption of a system of uniform oscillatory surface pressure distributions. The results, which are based on classical linear water-wave theory, show the close analogies which exist with theories for systems of absorbing oscillatory rigid bodies and a number of new reciprocal relations for pressure distributions are suggested and proved. Some simple examples illustrating the general results are given and compared with the corresponding results for rigid bodies.
Regular shock refraction in planar ideal MHD

We study the classical problem of planar shock refraction at an oblique density discontinuity, separating two gases at rest, in planar ideal (magneto)hydrodynamics. In the hydrodynamical case, 3 signals arise and the interface becomes Richtmyer-Meshkov unstable due to vorticity deposition on the shocked contact. In the magnetohydrodynamical case, on the other hand, when the normal component of the magnetic field does not vanish, 5 signals will arise. The interface then typically remains stable, since the Rankine-Hugoniot jump conditions in ideal MHD do not allow for vorticity deposition on a contact discontinuity. We present an exact Riemann solver based solution strategy to describe the initial self similar refraction phase. Using grid-adaptive MHD simulations, we show that after reflection from the top wall, the interface remains stable.
Buoyancy and Shear Characteristics of Hurricane-Tornado Environments

Abstract Detailed composite profiles of temperature, moisture, and wind are constructed for tornado environments in tropical cyclones that affected the United States during the period 1948–86. Winds are composited in components radial and tangential to the tropical cyclone center at observation time. Guided by observed patterns of tornado occurrence, composites are constructed for a variety of different stratifications of the data, including proximity to tornadoes, position relative to the cyclone center, time of day, time after cyclone landfall, cyclone translation speed, and location of landfall. The composites are also compared to composite soundings from Great Plains tornado environments. A variety of sounding parameters am examined to see which are most closely related to the patterns of tornado distribution. Lower-tropospheric vertical shears are generally stronger in the tropical cyclone tornado environments than on the Great Plains. Vertical shear and helicity parameters, along with 700-hPa wind s.
De-aging of Fe-doped lead-zirconate-titanate ceramics by electric field cycling: 180°- vs. non-180° domain wall processes

Acceptor-doped ferroelectrics tend to show pronounced aging behavior. The microscopic effects of aging are commonly related to oxygen vacancies, however, there are still open questions with respect to their impact on domain wall movements. To elucidate the latter, the reverse process of de-aging by electric field cycling is investigated here on Pb(Zr0.54Ti0.46)O3 doped with iron in different concentrations. Measurements of the hysteretic behavior of large-signal parameters, i.e., polarization and strain, as well as small-signal parameters, i.e., electrical permittivity and piezoelectric coefficient, are used to distinguish between reversible and irreversible movement of 180°- and non-180° domain walls. The results indicate that for low doping concentrations, the de-aging behavior of 180° domain wall motion is governed by irreversible domain wall motion and a coarsening of the domain structure, while for non-180° domain walls the change in reversible domain wall mobility is the dominant de-aging mechanism.