Miracle-dz/UniFAR-FTUs huggingface dataset:
Brillouin Scattering and Dispersion and Attenuation of Hypersonic Thermal Waves in Liquid Carbon Tetrachloride

Brillouin spectra of liquid CCl4 (at 20.0°C) have been investigated 20 scattering angles, from 40° to 145°. The spectra were excited by 6328‐A radiation from a He‐Ne laser and analyzed with a pressure‐scanned Fabry‐Perot spectrometer. The measured frequency shifts and linewidths of the Brillouin component were used to determine velocities and attenuations of thermal waves in the frequency range 1.6–4.7 Gc/sec. A large dispersion (>10%) and corresponding change in attenuation were found, characteristic of a thermal relaxation process in this region. A broad new component in the spectrum of isotropic scattering was observed, which is also characteristic of a relaxation process. Analyses of these data were carried out in two ways: one is based on a simple extension of acoustic equations to light scattering, and the other, on Mountain's theory of light scattering in the region of a thermal relaxation. It is shown that the observed spectra and derived data agree with Mountain's theory in all respects. Also, fr.
Managing Strategic Change of an Organization's Performance: A Case Study of Nzoia Sugar Company, Kenya

The Kenyan sugar sector is characterized by a series of decline and collapse of state funded milling companies despite massive funding by Government of Kenya. This study sought to establish major causes of Nzoia Sugar Company milling cane below daily target of 7000 tonnes, how strategies are formulated, implemented, controlled, and causes of resistance to change. The study employed census approach with target population of 44 staff members due to convenience and sensitivity of the information in the sugar industry. The research design was descriptive. The data for the study was both primary and secondary. Structured and unstructured questionnaires were the main tools for collecting primary data. Data was analyzed using multiple correlation analysis and descriptive statistics. Data was presented through graphs, pie-charts, frequency tables and figures. The findings showed that most of the workers who resisted change were subordinates comprising 67.7% while managers who resisted comprised 6.5%. The correlation significance was 0.05. There was positive correlation between improvement in performance and implementation of the strategies of +0.363. There was a negative correlation between resistance to change and involvement in resistance to change of -0.33. The study recommends involvement of all stakeholders in strategy formulation implementation and control.
An updated length‐scale formulation for turbulent mixing in clear and cloudy boundary layers

A new mixing‐length scale is presented for turbulence‐closure schemes, with special emphasis on neutral‐to‐convective conditions in clear and cloudy boundary layers. The length scale is intended for a prognostic turbulent‐kinetic‐energy closure. It is argued that present‐day length‐scale formulations may easily fail in one of two limiting situations. Schemes based on a local stability measure (e.g. the Richardson number) display unrealistic behaviour and instabilities in the convective limit. This strongly limits the representation of mixing in cloudy boundary layers. On the other hand, it is shown that non‐local parcel methods may misrepresent mixing near the surface. The new length‐scale formulation combines local and non‐local stability in a new way; it uses vertical integrals over the stability (the Richardson number) in a simple ‘parcel’ framework. The length scale matches with surface‐layer similarity for near‐neutral conditions and displays a realistic convective limit. The use of the length‐scale formulation can be extended easily to cloudy boundary layers. The scheme is numerically stable and computationally cheap. The behaviour of the length scale is evaluated in a single‐column model (SCM) and in a high‐resolution limited‐area model (LAM). The SCM shows good behaviour in three cases with and without boundary‐layer clouds. The prediction of the near‐surface wind and temperature in the LAM compares favourably with tower measurements at Cabauw (the Netherlands). Copyright © 2004 Royal Meteorological Society
Numerical integration based on evolutionary functional network

In this paper, a novel evolutionary functional network (EFN) is introduced. Firstly the generalized basis function is introduced, and then genetic programming is improved by changing the objects and structure of encoding. Sequences of generalized basis functions acts as individuals, general tree structure is used to encode them. Least square method (LSM) is used to design fitness function and by a number of evolutions, the optimum approximated model is achieved. The algorithm is used to compute the numerical integrals of all kinds of functions. Finally, results of 5 experiments show that this algorithm is effectively feasible and more accurate.
Quantum dot solar concentrator behaviour, predicted using a ray trace approach

SYNOPSIS Using a three-dimensional raytrace technique, a model to optimise the design of Quantum Dot Solar Concentrators for photovoltaic applications has been developed. The model includes reflection, refraction and absorption of solar radiation allowing the prediction of the optical efficiency. The optical efficiency is defined as the energy emitted from the selected edge or edges divided by the solar energy incident on the material. Using the model, a parametric analysis was performed and the optical properties of a selected system optimised. Details of the model and predictions of concentrator efficiency and ray path lengths for a range of quantum dot seeding levels are shown. The effects of path length on energy absorbed in the carrier material and that reaching the photovoltaic material are presented.
Inversion of experimental multi-frequency data using the contrast source inversion method

This paper presents the results of inversion of electromagnetic scattered field data, measured by the Institut Fresnel, Marseille, France, from cylindrical objects, for both TM illumination (electric field in the cylindrical direction) and TE illumination (electric field in the transversal plane). The reconstructions are obtained with the contrast source inversion method extended with a multiplicative regularization. We perform a simultaneous multi-frequency inversion. Since there are both dielectric and metallic objects, we do not take this a priori information into account and in all cases we reconstruct both the permittivity and the electrical conductivity of the unknown objects. The results show that the present inversion method enables 'blind' inversion of a wide class of scattered field data.
Electron Bernstein wave excitation by counterpropagating electromagnetic waves in a plasma

Two high-power counterpropagating electromagnetic waves (ω1,k1x) and (ω2,−k2x) in a low-density plasma in the presence of a static magnetic field Bsz, drive an electron Bernstein wave at the beat frequency ω=ω1−ω2 and k=(k1+k2)x, when ω∼ωc⪡ω1,ω2 and kρ≥1, where ωc is the electron cyclotron frequency and ρ is the Larmor radius. The electromagnetic waves exert a ponderomotive force on the electrons and resonantly drive the Bernstein mode(ω,k). When the pump waves have finite z extent, the Bernstein wave has an effective kz and a component of group velocity in the direction of the magnetic field, leaking it out of the interaction region, limiting the level of the Bernstein mode. Plasma inhomogeneity also introduces convection losses. However, the electron Bernstein mode potential could still be significantly greater than the ponderomotive potential.
Properties of sensitivity and complementary sensitivity functions in single-input single-output digital control systems

Sensitivity and complementary sensitivity functions play a key role in feedback control system design. This paper is concerned with the relation between the sampling period and the properties of these functions in digital control systems. Some integral constraints and the lower bounds of the H ∞-norm are derived, which show that the feedback performance for the unstable plant with the stable digital compensator can be improved as the sampling period goes to zero.
Radio structures of Seyfert galaxies. VII. Extension of a distance-limited sample

The VLA has been used at 6 and 20 cm to observe 27 Seyfert galaxies with recessional velocities less than 4600 km/s that had not been mapped previously. The sample shows weak trends for Seyfert 2 galaxies to have more luminous and larger radio sources than Seyfert 1 galaxies. A 20 cm radio luminosity function is constructed for each Seyfert type and shown to be fairly flat for powers betwen 10 to the 20th and 10 to the 23rd W/Hz. About 10 percent of the galaxies in the present sample may have flat-spectrum components contributing a substantial amount of their total flux density at centimeter wavelengths. 39 refs.
Vertical diffusion of the far wake of a sphere moving in a stratified fluid

The far wake of a sphere towed horizontally in a linearly stratified fluid with Froude numbers F ∈ (0.25,12.7) and Reynolds numbers Re ∈ [150,30 000] is investigated. Regardless of the initial Froude number, the wake becomes quasi two dimensional at times large compared with the Brunt–Vaisala period. For F≤4.5, the horizontal motions are coherent over the whole depth of the wake. The wake takes the form of a regular von Karman street for F≤1.5 but is irregular at larger F. For F≥4.5 the far wake consists of, vertically incoherent, horizontal motions in several layers. The transition occurs smoothly by a vertical decorrelation of the horizontal motion in the depth of the far which starts at F=4.5. The most novel result is that the horizontal velocity and vertical vorticity diffuse vertically in a time much shorter than predicted by a viscous diffusion law. The ratio of the observed diffusion time to the viscous diffusion time is expected to depend on Reynolds number as is indicated by a simple model.
The External Origin of the Gas in S0 Galaxies

In this Letter we present three new cases of S0 galaxies, namely NGC 2768, NGC 4379, and IC 4889, out of a sample of 15, in which the gas is counterrotating or strongly kinematically decoupled with respect to the stellar body of the galaxy. Assuming gas infall with randomly oriented angular momentum, this result implies that in 40% of the galaxies in our sample, the ionized gas is of external origin. However, several pieces of evidence suggest that the acquisition of external gas in S0 galaxies can be even more general
Spectroscopic second harmonic generation measured on plasma-deposited hydrogenated amorphous silicon thin films

Optical second harmonic generation (SHG) has been measured for plasma-deposited thin films of hydrogenated amorphous silicon (a‐Si:H) at different polarization states for pump photon energies between 1.0 and 1.7eV. Distinct resonance peaks are observed in this energy range and it is shown that the SH signal originates from an isotropic contribution at both the film-surface and substrate-interface region. The possibility that the SH signal originates from surface and interface dangling bond states of a‐Si:H is discussed.
Plasma-particle interaction for strong stochastic magnetic fields: Isotropic and anisotropic scattering regimes

We investigate theoretically the interaction between charged particles and a plasma by calculating the scattering anisotropy. In several physical environments such as supernova shells, we expect strong stochastic magnetic fields. As shown, particle scattering is anisotropic in real physical situations even if the stochastic magnetic fields are isotropic and much stronger than the mean magnetic field. This anisotropic scattering result is very important for understanding diffusive shock acceleration, a mechanism which is usually thought to be responsible for the high energies of cosmic rays.
Modeling and Optimal Design of Machining-Induced Residual Stresses in Aluminium Alloys Using a Fast Hierarchical Multiobjective Optimization Algorithm

The residual stresses induced during shaping and machining play an important role in determining the integrity and durability of metal components. An important issue of producing safety critical components is to find the machining parameters that create compressive surface stresses or to minimize tensile surface stresses. In this article, a systematic data-driven fuzzy modeling methodology is proposed, which allows constructing transparent fuzzy models considering both accuracy and interpretability attributes of fuzzy systems. The new method employs a hierarchical optimization structure to improve the modeling efficiency, where two learning mechanisms cooperate together: the Nondominated Sorting Genetic Algorithm II (NSGA-II) is used to improve the model's structure, while the gradient descent method is used to optimize the numerical parameters. This hybrid approach is then successfully applied to the problem that concerns the prediction of machining induced residual stresses in aerospace aluminium alloys. Based on the developed reliable prediction models, NSGA-II is further applied to the multiobjective optimal design of aluminium alloys in a “reverse-engineering” fashion. It is revealed that the optimal machining regimes to minimize the residual stress and the machining cost simultaneously can be successfully located.
A study on germination and seedling growth of Blcakgram ( Vigna mungo L . Hepper ) germplasm against Polyethylene glycol 6000 stress

Seed germination is considered as one of the first and foremost fundamental life stages of a plant, where the success in growth and yield is also depending on this stage. An experiment was conducted in order to study the effect of different concentrations (i.e. 0, 10, 20 and 30 %) of polyethylene glycol (PEG) stress on germination and early growth stages of 29 inbred lines of blackgram (Vigna mungo L. Hepper) in Plant Physiology laboratory, Department of Botany and Microbiology, Acharya Nagarjuna University. Different germination indices such as rate of imbibition, germination percent, germination energy, radical length, shoot length, relative water content, protein, nitrogen and biochemical parameters such as proline, peroxidise, polyphenol oxidase, catalase and superoxide dismutase along with drought parameters like percent injury, drought tolerance index was measured. Results showed significant differences among the cultivars at each drought stress level and significant decrease was observed in imbibition percentage, germination, length of radicle and plumule and radicle and plumule dry matter along with biochemical parameters. Among all the test genotypes LBG 17, LBG 764, LBG 752 and LBG 756 showed their efficiency in terms of germination and germination attributes besides showing more biochemical activity to with stand to the drought conditions and suggested to cultivate in soils with less moisture availability.
Single-cavity wavelength-switched fiber ring laser based on fiber bending effect in mach-zehnder interferometer

The author has experimentally demonstrated a wavelength switching single cavity fiber ring laser incorporating a Mach–Zehnder interferometer with two optical wavelength thin film filters. By changing the radius of the fiber bending in one path, the wavelength gradually shifts from one wavelength to another or forms a dual-wavelength operation due to the laser gain competition depending on the path loss.
Motion of high-current vacuum arcs on spiral-type contacts

Motion of vacuum arcs on spiral-type contacts is not only controlled by self-induced magnetic fields, but also by heating phenomena. An expression is derived which permits the calculation of the speed of the arc from a computation of the time needed to heat the surface up to boiling temperature. The heat flux density of the constricted arc at the anode is required as input for the calculation. Good coincidence is achieved with experimental data. The speed of the arc varies from 5 to 400 m/s, depending on experimental conditions. >
A modification of the test of Shapiro and Wilk for normality

The W statistic of Shapiro and Wilk provides the best omnibus test of normality, but its application is limited up to n= 50. This study modifies W, such that it can be extended for all sample sizes. The critical values of W, i.e. the modification of W, is given for n up to 5000. The empirical moments show that the null distribution of W is skewed to the left and is consistant for all sample sizes. Empirical powers of W are also comparable with those of W.
Regulation of a one-link flexible robot arm using sliding-mode technique

Abstract This paper is concerned with the application of sliding control’ to the regulation of a one-link flexible robot arm, with an arbitrary number of flexible modes. Slidingmode technique is applied to achieve a robust feedback linearization of the highly non-linear dynamic equation of the arm. Pole placement is then used to attain good dynamic response. An example is given to demonstrate the potential of the sliding method. This work serves as a first step towards a practical solution in the feedback control of flexible arms using the sliding technique.
Plasmon emission in photoexcited gold nanoparticles

Light emission at the particle plasmon frequency is observed in optically excited spherical gold nanoparticles. We find a photoluminescence efficiency of ${10}^{\ensuremath{-}6}$, which is essentially independent of particle size and four orders of magnitude higher than the efficiencies determined from metal films. Our experimental findings are explained with a process in which excited $d$-band holes recombine nonradiatively with $\mathit{sp}$ electrons, emitting particle plasmons. These plasmons subsequently radiate, giving rise to the photoluminescence observed in the experiment. We determine the quantum efficiencies involved in this process.
Change in Charging Characteristics of High Polymers due to Plasma Treatment

Polymer films of high density polyethylene (HDPE) and Nylon 12 were plasma-treated in Ar gas and the effect of the treatment on their charging characteristics was investigated. After the plasma treatment,the contact angle of each film decreased and films tended to became more negatively charged. The contact angle and the charging characteristics gradually recovered with time and appeared to reach constant values 10 days after the treatment.
Large‐eddy simulation: A critical review of the technique

Large-eddy simulation is being increasingly used as a means of both predicting the properties of specific turbulent flows and providing flow details which can be used like data to test and refine other turbulence-closure models. Although such simulations derive their credibility from the explicit resolution of large-scale turbulent eddies, they depend upon a small-scale turbulence closure and must to some degree inherit the many uncertainties associated with turbulence closure. Most results obtained to date have been very encouraging, with examples of good agreement with observations and insensitivity to the small-scale turbulence closure. However, there are some counter examples of incorrect prediction in circumstances where the small-scale closure is critical. The evidence from the simulations suggests that this critical behaviour may only occur in the regions of large-eddy simulation where matches to boundaries, or regions of statically stable fluid, are encountered. In such regions an empirical approach dominates, and there is evidence that the small-scale turbulence closure must represent stochastic fluctuations of the unresolved stresses. Although there is a need to refine the small-scale turbulence models, it is clear from the promise of current applications that, with the expected growth in computer power, this technique will have increasing breadth of application. Here the underlying assumptions and current practical implementations of the technique are critically reviewed.
The Count of Monte Carlo : Analysing Global Banking and Currency Crises , 1883-2008 . Mardi Dungey

An empirical model of nancial crises is speci ed and estimated using annual data for the period 1883 to 2008. Contagion is explicitly modelled by allowing additional linkages across countries when the number of crises reaches a threshold level. As the data are characterised as counts of the number of countries experiencing a crisis within a year, a threshold integer autoregressive moving average model (TINARMA) is speci ed. An EMM estimator which uses Monte Carlo simulations is proposed as estimation by maximum likelihood is infeasible. The empirical results show strong evidence of contagion during currency and banking crises, with additional evidence of a potential 10 year cycle. Keywords: count time series; binomial thinning; e¢ cient method of moments JEL Classi cation: C150, C220, C250
Average nutrient uptake by a self-propelled unsteady squirmer

We present results for the average mass transfer to a spherical squirmer, a model micro-organism whose surface oscillates tangentially to itself. The surface motion drives a low-Reynolds-number flow which enables the squirmer either to swim relative to the fluid at infinity, at an average speed proportional to a streaming parameter, $W$, or to stir the fluid around it while remaining, on average, at rest (if $W\,{=}\,0$), as represented by a hovering parameter, $b$. We assume that the amplitude of the time-periodic surface distortions is scaled by a dimensionless small parameter $\epsilon$, and consider only high Péclet numbers $P$ – a measure of convection versus diffusion – by setting $P^{-1acute;\,{=}\,\epsilon^2 \gamma$, where $\gamma$ is a parameter of $O(1)$. It is shown that the average mass concentration distribution satisfies a steady convection–diffusion equation with an effective velocity field that is different from the actual mean velocity field. The model is used to calculate the mass transfer across the surface of the squirmer, measured by the mean Sherwood number $Sh$. We find asymptotic solutions for small and large $\gamma$ and numerical results for the whole range of values. While the large-$\gamma$ expansions are reproduced well by the numerical results, there is a discrepancy between the two at small $\gamma$. We believe this is due to very small recirculation regions, attached to the surface of the squirmer, which make boundary layer theory applicable only when $1/\gamma$ is immense. For the parameters chosen in this study, results indicate that both hovering and streaming contribute to the mass transfer, although streaming has a greater effect. Also, energy dissipation considerations show that an optimum swimming mode exists, at least at small and large $\gamma$, for any given uptake rate. However, other factors have still to be taken into account, and the model realism improved, if we want to make predictions for real aquatic micro-organisms.
The Internationalization of Chinese Firms: A Case for Theoretical Extension?

This paper examines the patterns of, and motives for, internationalization by prominent market-seeking Chinese firms. Case studies of these firms indicate that they are seeking technological and brand assets to create a competitive position in international markets. While mainstream theory tends to assume that firms internationalize to exploit competitive advantages, Chinese firms are generally making such investments in order to address competitive disadvantages. They are engaging in 'inward' internationalization by means of original equipment manufacture (OEM) and joint venture partnerships, and 'outward' internationalization by means of acquisition and organic expansion abroad. Each of these routes offers certain benefits coupled with its own challenges or risks. The paper concludes that the Chinese case offers an opportunity to extend present theorizing in four primary areas concerning the latecomer perspective and catch-up strategies, institutional analysis with reference to the role of government, the relations between entrepreneurs and institutions, and the liability of foreignness.