Miracle-dz/UniFAR-FTUs huggingface dataset:
Coherent baroclinic eddies on a sloping bottom

A coherent and stable baroclinic eddy in a rotating fluid was produced on a sloping bottom by releasing a dome of salt water into the ambient fresh water. A strong cyclonic vortex is produced above the heavy dome. The entire eddy system moves ‘north-westward’ (with the up-slope direction designated ‘north’) as a ‘Taylor column’. The eddy system displays long lifetimes, but it is shown that a theory of isolated systems cannot account for the experimental observations. Instead, it is demonstrated that the vortex flow above the lens is along the lines of constant depth, producing a net pressure force on the lens, which approximately balances the buoyancy force. When Ekman friction is also included, it accounts for the northward motion of the dome.
CHARACTERISTIC LYAPUNOV EXPONENTS AND SMOOTH ERGODIC THEORY

CONTENTSPart I § 1. Introduction § 2. Prerequisites from ergodic theory § 3. Basic properties of the characteristic exponents of dynamical systems § 4. Properties of local stable manifoldsPart II § 5. The entropy of smooth dynamical systems § 6. "Measurable foliations". Description of the π-partition § 7. Ergodicity of a diffeomorphism with non-zero exponents on a set of positive measure. The K-property § 8. The Bernoullian property § 9. Flows § 10. Geodesic flows on closed Riemannian manifolds without focal pointsReferences
Similarity Analysis of the Radiative Gas Dynamic Equations with Spherical Symmetry

Similarity representation of the radiative gas dynamic equations with spherical symmetry, amenable to a wide variety of radiation law, is presented. The general representation of the equations of motion is effected by the simple artifice of retaining the definitions of the radiant quantities as operators on the radiative intensity and of recognizing the variability of the index refraction. Specific constitutive forms for the radiation field manifest themselves in implied constraint conditions. Because of radiative heating, similarity structure may be prescribed for the gas on both sides of shock waves. Numerical examples are constructed for strong explosions and implosions.
Dust-Coulomb and dust-acoustic wave propagation in dense dusty plasmas with high fugacity

A detailed investigation of electrostatic dust wave modes in unmagnetized dusty plasmas consisting of electrons, ions and dust grains has been carried out over a wide range of dust fugacity and wave frequency by using fluid as well as kinetic (Vlasov) theories. The dust fugacity parameter is defined by f≡4πnd0λD2R∼ND R/λD where nd0, λD and R are respectively the dust number density, the plasma Debye length and the grain size (radius), and ND=4πnd0λD3/3 is the dust plasma parameter. Dusty plasmas are considered to be tenuous, dilute or dense according as f≪1, ∼1, or ≫1. In particular, attention is focused on the “dust–acoustic waves” (DAWs) and the “dust–Coulomb waves” (DCWs) which exist in the tenuous (low fugacity) and the dense (high fugacity) regimes, respectively, when the wave frequency is much smaller than the grain charging frequency. Unlike the DAWs, which exist even with constant grain charge, the DCWs [N. N. Rao, Phys. Plasmas 6, 4414 (1999)] are the normal modes associated with grain char.
On a penetrating radiation from thunderclouds

The possibility of the production of fast β-rays by a charged thundercloud has been discussed by Professor C. T. R. Wilson, who has shown that such a cloud should spray upwards a stream of “runaway electrons” of energy as high as 5 × 109 electron-volts. The action of the earth’s magnetic field upon this stream should cause it to return to the earth at considerable distances from the cloud, supposing that the energy of the particles was not converted into γ-radiation by nuclear encounters on the way. A search for such particles in the region below a thundercloud has already been made by one of us, but without success. The fact that they are not produced in this region can be ascribed either to the field being too small and limited in extent or to the effect of nuclear stoppage. Although their presence would have strengthened the original suggestion, their absence does not invalidate Wilson’s view that upward-moving particles generated in the strong field within the cloud do exist. To test this suggestion directly, however, Is a more difficult problem, for the supposed electron spray as it returned to earth would be spread out over a wide region and its intensity at any particular point would not be large.
Roll waves on a shallow layer of mud modelled as a power-law fluid

We give a theory of permanent roll waves on a shallow layer of fluid mud which is modelled as a power-law fluid. Based on the long-wave approximation, Kármán's momentum integral method is applied to derive the averaged continuity and the momentum equations. Linearized instability analysis of a uniform flow shows that the growth rate of unstable disturbances increases monotonically with the wavenumber, and therefore is insufficient to suggest a preferred wavelength for the roll wave. Nonlinear roll waves are obtained next as periodic shocks connected by smooth profiles with depth increasing monotonically from the rear to the front. Among all wavelengths only those longer than a certain threshold correspond to positive energy loss across the shock, and are physically acceptable. This threshold also implies a minimum discharge, viewed in the moving system, for the roll wave to exist. These facts suggest that a roll wave developed spontaneously from infinitesimal disturbances should have the shortest wavelength corresponding to zero dissipation across the shock, though finite dissipation elsewhere. The discontinuity at the wave front is a mathematical shortcoming needing a local requirement. Predictions for the spontaneously developed roll waves in a Newtonian case are compared with available experimental data. Longer roll waves, with dissipation at the discontinuous fronts, cannot be maintained if the uniform flow is linearly stable, when the fluid is slightly non-Newtonian. However, when the fluid is highly non-Newtonian, very long roll waves may still exist even if the corresponding uniform flow is stable to infinitesimal disturbances. Numerical results are presented for the phase speed, wave height and wavenumber, and wave profiles for a representative value of the flow index of fluid mud.
On estimating equations with censored data

SUMMARY General estimating equations based on independent identically distributed random variables which may be right-censored are considered. The equations which appear to be natural analogues of the uncensored equations require full distributional assumptions, and a distribution-free modification based on the product-limit estimator is suggested. It follows from self-consistency that the resulting estimating functions are simply means obtained from the product-limit estimator. The asymptotic variances of the estimators obtained from the equations are derived and compared.
Order picking under random and turnover-based storage policies in fishbone aisle warehouses

A recent trend in the layout design of unit-load warehouses is the application of layouts without conventional parallel pick aisles and straight middle aisles. Two examples for such designs are flying-V and fishbone designs for single- and dual-command operations. In this study, it is shown that the multi-item order picking problem can be solved in polynomial time for both fishbone and flying-V layouts. These two designs are compared with the traditional parallel-aisle design under the case of multi-item pick lists. Simple heuristics are proposed for fishbone layouts that are inspired by those put forward for parallel-aisle warehouses and it is experimentally shown that a modification of the aisle-by-aisle heuristic produces good results compared with other modified S-shape and largest gap heuristics when items have uniform demand. Computational experiments are performed in order to compare the performances of fishbone and traditional layouts under optimal routing and it is shown that a fishbone design can obtain improvements of around 20% over parallel-aisle design in single-command operations but can perform as high as around 30% worse than an equivalent parallel-aisle layout as the size of the pick list increases. The sensitivity of the results to varying demand skewness levels when volume-based storage is applied is tested and it is shown that unlike the single- and dual-command cases, a fishbone design performs better compared to a traditional design under highly skewed demand as opposed to uniform demand.
Performance of plate finned tube heat exchangers under dehumidifying conditions

Systematic studies of continuous fin-and-tube tube heat exchangers under dehumidifying conditions are reported in the present study. The heat exchangers consist of nine fin-and-tube heat exchangers having plane fins. The effects of fin spacing, the number of tube row, and inlet conditions are investigated. Data are presented in terms of j factors and friction factors f . It is found that the inconsistencies in the open literature may be associated with the wet fin efficiency. A correlation is proposed for the present plate fin configuration; this correlation can describe 92 percent of j , and 91 percent of the f data within ±10 percent.
The Formation of Nocturnal Rainfall Offshore from Convection over Western Kalimantan (Borneo) Island

This study investigates the diurnal variation of convection over western Kalimantan (Borneo) Island and the adjacent seas through analysis of results from surface meteorological observations, satellite observations of convection and precipitation, and numerical experiments with a mesoscale model. Precipitation measurements from the TRMM satellite indicated that rainfall occurs mostly in the afternoon and evening along the coast of the island, and at night and in the early morning over the plains in the central regions of the island and over the sea adjacent to the coast. Results from surface meteorological observations showed that intense shortwave radiation is observed on the western coast at Siantan on most days, even on days with heavy rain. Consequently, sea breezes are evident in the afternoon, whereas land breezes prevail in the early morning. Occasionally, a strong offshore flow is observed by the QuikSCAT satellite over the sea adjacent to the western coast of the island in the early morning, with calm surface winds on the coastal land.Climate modeling studies for a 1-month period during the region’s rainy season successfully replicated the main features of the observed regional distribution, diurnal variation of surface winds and convection over the western coast of the island and the adjacent seas. The results showed that convections develop across a wide area along the coast of the island at similar times in the late afternoon with the penetration of the sea breeze. The convections cause a rapid drop in temperature in the lower atmosphere, which produces a temperature contrast between the land and the sea, with lower temperatures occurring over the island. In response to the temperature differences, a strong offshore flow occurs over the sea adjacent to the western coast during nighttime, which creates an intensive wind convergence at the low-levels, and initiates convection offshore near the coast at late night and early morning. The results of this study suggest that the strong offshore flow derived principally from convections that develop earlier in the afternoon and evening over the island plays an important role in the formation of the nocturnal rainfall over the sea in the vicinity of western Kalimantan Island.
Advantages of the Green Solid State FSW over the Conventional GMAW Process

The present work is an experimental comparison between the friction stir welding (FSW) and the conventional gas metal arc welding (GMAW) in joining of Al alloys. Two sets of 3 mm thick aluminum strip pairs were friction stir welded in a regular butting joint configuration. Two rotational speeds of 1750 rpm and 2720 rpm were utilized to perform the FSW process. The axial force and the transverse speed were kept constant at 6.5 KN and 45 mm/min, respectively. Cylindrical tool shoulder and pin geometry were selected. Strip pairs of other similar sets were butt jointed using the conventional GMAW. The welding quality, power input, and macrostructure and microstructure of the butted joints were examined. The types of the fumes and the amount of the released gases were measured and compared. The results showed that the solid state FSW is green, environment-friendly, and of superior welding properties compared to the conventional GMAW.
Grouping for Testing Trends in Categorical Data

Abstract In many studies there is believed to be a trend in a categorical variate with a continuous variate. Often in these cases it is desired to test for the trend using k groups formed from the continuous variable. This article is concerned with the grouping problem where the goal is essentially to maximize the asymptotic efficiency of the test. Optimal classes are given for k = 2, 3, 4, 5 and 6 for the uniform, normal and exponential distributions. Also, the number of groups to use and the “robustness” of the optimal grouping are investigated. It is noted that the “mathematical problem” in determining the optimal classes appears in other studies; a rationale for this is presented.
350 Micron Images of Massive Star Formation Regions

We present 350 μm continuum images of 24 massive star formation regions obtained with the Caltech Submillimeter Observatory equipped with the SHARC focal-plane array. At this wavelength the spatial resolution is 11″. The 350 μm emission is compared with thermal radio continuum emission and OH, H2O, and CH3OH masers. Emission at 350 μm is believed to be thermal emission from dust heated by embedded or nearby stars. Compact radio continuum sources are usually present in the mapped 350 μm fields, and more than 60% of the 350 μm peaks coincide with radio continuum peaks. This association lends strong support to the notion that the dust is heated primarily by hot stars. Masers are also a common property of massive star formation regions. Usually OH, H2O, and/or CH3OH masers are found near, but generally not coincident with, the 350 μm peaks. Less than 25% of the 350 μm peaks have no reported masers located close by. In most of the observed regions, the 350 μm dust maps show one or more components surrounded by fainter extended emission. In total, we identify 28 separate 350 μm components. Ten of the 28 components do not have radio continuum counterparts. These are luminous sources and should produce detectable H II regions. It is postulated that these sources may be undergoing such rapid accretion that the infalling matter quenches the H II region very close to the protostar, thereby making the H II region undetectable in free-free emission. Objects in this evolutionary state may well represent the long-sought precursors to ultracompact H II regions and should have the properties of accreting massive protostars (e.g., accretion disks, bipolar molecular outflows, hot shocked gas, infall with spin-up toward the protostar). We suggest that the 10 sources in this category in our sample merit further observational study for these properties. Two-temperature graybody models constrained by the observed infrared spectral energy distributions were calculated to estimate the total mass, luminosity, average dust temperature, and hydrogen column and number densities for each source. The graybody models do not account for possible low-level emission from the coolest dust (<25 K) and therefore may underestimate the total mass. There is, however, no evidence for emission in excess of the models at 1.3 mm, and we conclude that the mass contribution of dust colder than ∼25 K cannot be large. Thus, the graybody models shown provide useful average global properties required to understand massive star formation environments.
Cosmological deductions from the alignment of local gravity and motion

L'alignement du mouvement du Groupe Local au travers du fond microonde cosmique et du flux optique net determine a partir de catalogues de galaxies est considere. Le rapport du dipole optique au taux d'accroissement du monopole optique est utilise pour determiner le parametre Ω directement sur l'echelle 1 pour cent du rayon de Hubble
230 s room-temperature storage time and 1.14 eV hole localization energy in In0.5Ga0.5As quantum dots on a GaAs interlayer in GaP with an AlP barrier

A GaP n+p-diode containing In0.5Ga0. 5As quantum dots (QDs) and an AlP barrier is characterized electrically, together with two reference samples: a simple n+p-diode and an n+p-diode with AlP barrier. Localization energy, capture cross-section, and storage time for holes in the QDs are determined using deep-level transient spectroscopy. The localization energy is 1.14(±0.04) eV, yielding a storage time at room temperature of 230(±60) s, which marks an improvement of 2 orders of magnitude compared to the former record value in QDs. Alternative material systems are proposed for still higher localization energies and longer storage times.
On the Rate of Multivariate Poisson Convergence

The distribution of the sum of independent nonidentically distributed Bernoulli random vectors inRkis approximated by a multivariate Poisson distribution. By using a multivariate adaption of Kerstan's (1964,Z. Wahrsch. verw. Gebiete2, 173? 179) method, we prove a conjecture of Barbour (1988,J. Appl. Probab.25A, 175? 184) on removing a log-term in the upper bound of the total variation distance. Second-order approximations are included.
Numerical and Experimental Study of Solidification in a Spherical Shell

The present study explores numerically and experimentally the process of a phase-change material (PCM) solidification in a spherical shell. At the initial state, the PCM liquid occupies 98.5% of the shell. The upper segment of 1.5% contains air, which flows in as the solidification progresses. In the experiments, a commercially available paraffin wax is used. Its properties are engaged in the numerical simulations. The investigation is performed for solidification in spherical shells of 20 mm, 40 mm, 60 mm, and 80 mm in diameter at the wall uniform temperature, which varied from 10°C to 40°C below the mean solidification temperature of the phase-change material. Transient numerical simulations are performed using the FLUENT 6.2 software and incorporate such phenomena as flow in the liquid phase, volumetric shrinkage due to solidification, and irregular boundary between the PCM and air. The numerical model is validated versus the experimental results. Shrinkage patterns and void formation are demonstrated. Dimensional analysis of the results is performed and presented as the PCM melt fractions versus the product of the Fourier and Stefan numbers. This analysis leads to a generalization that encompasses the cases considered herein.
Anomalously high plasma densities in the plasma sheet boundary layer

We report the first observation of a high-density (5 cm−3) plasma region with low perpendicular temperature (less than 30 eV) in the plasma sheet boundary layer. We used several experiments on board the ISEE spacecraft. The plasma density is determined by the relaxation sounder. The hot particle and magnetic field measurements show that high-density regions are observed next to the region of high hot particle fluxes, and they also put an upper limit on the perpendicular temperature of the dense plasma population. Current sheets flowing primarily in the ± Y direction for this event are identified using their magnetic signature in the region of hot particle gradient.
QUALITATIVE ANALYSIS OF A NONLINEAR WAVE EQUATION

We study the qualitative behavior of solutions of a wave equation with nonlinear damping and a source term. We give a characterization of blow-up of solutions, improving a previous result. When the dissipation dominates the source term, we show existence of unbounded global solutions. We use the stable (potential well) and unstable sets, introduced by Sattinger and Payne. We study all bounded global solutions, and we charaterize their convergence as $t \rightarrow \infty$. In particular, we prove that every solution, with energy larger or equal than the depth of the potential well, is global, bounded and converges to the set of nonzero equilibria.
Influence of an evanescence layer in front of the antenna on the coupling efficiency of ion cyclotron waves

The effect on coupling of an evanescent layer in front of ion cyclotron fast-wave antennas is commonly described by the exponential factor exp(−2k‖d), with k‖ the parallel wave vector of the peak of the launched wave spectrum and d the width of the evanescence layer. With an elementary one-dimensional model, we demonstrate that this dependence is too pessimistic, as confirmed by recent experiments.
Evidence for systematic evolution in the properties of galaxies in distant clusters

This paper investigates the evolution of galaxies as a function of look-back time, primarily using early-type galaxies in rich cluster environments. We demonstrate that, by selecting distant galaxies in the near-infrared, representative samples containing approximately the same proportion of galaxy classes can be constructed independently of redshift, thus avoiding biases introduced by optical selection criteria. Using this method, we construct a sample of 180 galaxies selected at near-infrared wavelengths in the fields of 10 rich clusters with 0.5 < z < 0.9. Observing and data processing techniques, with infrared arrays yielding the required high-precision photometry of cluster members, are discussed
The magnetostriction and stress dependence of the magneto-impedance effect in ribbons of amorphous ?

Amorphous ribbons of have been stress annealed in order to study the influence of magnetostriction on the magneto-impedance effect and its behaviour with applied tensile stresses. Magnetostriction is shown to be an important parameter that can be used to regulate the magneto-impedive response, as well as permeability and induced anisotropy. The amorphous ribbons change their saturation magnetostriction constants depending on the annealing parameters, between and and exhibit high values of the sensitivity to the applied magnetic fields in the magneto-impedance measurements, up to in the unstressed state and up to in the case of applying a 130 MPa tensile stress, at a frequency of 1 MHz.
Correlation between crystal structure and magnetic properties of Gd5(SixGe1-x)4 compounds

Based upon the reported crystal structure data of Gd5 (Six Ge1-x )4 compounds, a possible correlation between the crystal structure and magnetic properties of the compounds is explored. An almost linear dependence of the ferromagnetic ordering temperature on a M-M (M = Si, Ge or a mixture of Si and Ge) bond length is derived within a first approximation. It is argued that the mechanism of the ferromagnetic coupling in the Gd5 Si4 -based (x >0.5) and Gd5 Ge4 -based (x 0.2) solid solutions is the same as that in the intermediate phase Gd5 (Six Ge1-x )4 (0.24 x 0.5), i.e. the ferromagnetic Gd-(Gd, M)-Gd blocks couple with each other via an M2 layer, regardless of their crystal structures at room temperature. The M-M bond length in the M2 layer is a crucial structural parameter governing the ferromagnetic ordering temperature of the compounds. The orthorhombic structure of the intermediate phase at low temperature is stabilized by the ferromagnetic exchange interaction.