Miracle-dz/UniFAR-FTUs huggingface dataset:
Effect of metal/substrate interfaces on radio-frequency loss in superconducting coplanar waveguides

Microscopic two-level systems (TLSs) are known to contribute to loss in resonant superconducting microwave circuits. This loss increases at low power and temperatures as the TLSs become unsaturated. We find that the loss is dependent on both the substrate-superconductor interface and the roughness of the surfaces. A native, oxide-free interface reduced the loss due to TLSs. However, a rough surface in the CPW gap did not cause more TLS loss, but the overall loss was significantly increased for the roughest surfaces.
Temperature and velocity field regimes of convective motions in a rotating plane fluid layer

The paper is a continuation of work published in Boubnov & Golitsyn (1986). We present new measurements of the temperature and velocity field patterns and their statistical characteristics. This allows us to classify regimes of convection in a plane rotating horizontal fluid layer in terms of Rayleigh and Taylor numbers. Within the irregular regimes geostrophic convection is found for which the Rossby number is much less than unity. In the regular regimes the mean temperature profiles are linear with height in the bulk of the fluid, the gradient being dependent mainly on rotation rate Ω and fluid depth h. These together with some dimensional arguments lead to the heat transfer relationship Nu ∝ Ra3 Ta−2 between Nusselt, Rayleigh and Taylor numbers. Experimental results by Rossby (1969) and theoretical work by Chan (1974) and Riahi (1977) suggested this dependence. The dependence on ωτ of the temperature power spectrum normalized by the variance was found to be universal at higher frequencies for all irregular convective motions, where τ is the timescale of the thermal boundary layer for cases with a small influence of rotation and with τ about three times larger (in numerical coefficient) for geostrophic convection. For irregular geostrophic regimes it is found that the temperature variance depends on rotation rate and heat flux, and is inversely proportional to the buoyancy parameter. Horizontal and vertical components of the velocity fields were measured for regular as well as irregular regimes, confirming, especially for geostrophic convection, the theoretical results by Golitsyn (1980). In conclusion some geophysical applications are briefly mentioned.
Vibrations of an infinite viscoelastic layer with a dissipative memory

A model of elastic‐energy dissipation based on a memory mechanism with two degrees of freedom is applied to the problem of the determination of the response spectrum at the surface of a layer when the spectrum is given at the bottom. The reaction of the surface of the layer is obtained directly with the Laplace‐transform method. With the Fourier method, the amplification function is also found at the surface of the layer; it depends on the first power of the coefficient of viscosity—the Q−1 is proportional to a fractional power of the frequency. The reaction inside of the layer in the case of an infinite layer has also been obtained as function of time and in the Fourier space. It is verified that the amplification function (namely, the peak amplitude response of the free surface of the viscoelastic layer at a “resonant frequency”) depends strongly on the dissipation mechanism; a complete knowledge of the parameters of this mechanism could be of great help in the solution of many physical and engineering .
INSIGHTS INTO FILAMENT ERUPTION ONSET FROM SOLAR DYNAMICS OBSERVATORY OBSERVATIONS

We examine the buildup to and onset of an active region filament confined eruption of 2010 May 12, using EUV imaging data from the Solar Dynamics Observatory (SDO) Atmospheric Imaging Array and line-of-sight magnetic data from the SDO Helioseismic and Magnetic Imager. Over the hour preceding eruption the filament undergoes a slow rise averaging ∼3 km s−1, with a step-like trajectory. Accompanying a final rise step ∼20 minutes prior to eruption is a transient preflare brightening, occurring on loops rooted near the site where magnetic field had canceled over the previous 20 hr. Flow-type motions of the filament are relatively smooth with speeds ∼50 km s−1 prior to the preflare brightening and appear more helical, with speeds ∼50–100 km s−1, after that brightening. After a final plateau in the filament's rise, its rapid eruption begins, and concurrently an outer shell “cocoon” of the filament material increases in emission in hot EUV lines, consistent with heating in a newly formed magnetic flux rope. The main flare brightenings start ∼5 minutes after eruption onset. The main flare arcade begins between the legs of an envelope-arcade loop that is nearly orthogonal to the filament, suggesting that the flare results from reconnection among the legs of that loop. This progress of events is broadly consistent with flux cancellation leading to formation of a helical flux rope that subsequently erupts due to onset of a magnetic instability and/or runaway tether cutting.
Stability of spatially developing boundary layers in pressure gradients

A new formulation of the stability of boundary-layer flows in pressure gradients is presented, taking into account the spatial development of the flow and utilizing a special coordinate transformation. The formulation assumes that disturbance wavelength and eigenfunction vary downstream no more rapidly than the boundary-layer thickness, and includes all terms nominally of order R−1 in the boundary-layer Reynolds number R. In Blasius flow, the present approach is consistent with that of Bertolotti et al. (1992) to O(R−1) but simpler (i.e. has fewer terms), and may best be seen as providing a parametric differential equation which can be solved without having to march in space. The computed neutral boundaries depend strongly on distance from the surface, but the one corresponding to the inner maximum of the streamwise velocity perturbation happens to be close to the parallel flow (Orr-Sommerfeld) boundary. For this quantity, solutions for the Falkner-Skan flows show the effects of spatial growth to be striking only in the presence of strong adverse pressure gradients. As a rational analysis to O(R−1) demands inclusion of higher-order corrections on the mean flow, an illustrative calculation of one such correction, due to the displacement effect of the boundary layer, is made, and shown to have a significant destabilizing influence on the stability boundary in strong adverse pressure gradients. The effect of non-parallelism on the growth of relatively high frequencies can be significant at low Reynolds numbers, but is marginal in other cases. As an extension of the present approach, a method of dealing with non-similar flows is also presented and illustrated. However, inherent in the transformation underlying the present approach is a lower-order non-parallel theory, which is obtained by dropping all terms of nominal order R−1 except those required for obtaining the lowest-order solution in the critical and wall layers. It is shown that a reduced Orr-Sommerfeld equation (in transformed coordinates) already contains the major effects of non-parallelism.
Ultrasonic measurement of milk coagulation time

Using a pulse reflection technique an ultrasonic system has been developed to monitor in situ the coagulation process of rennetted milk. The velocity and attenuation of ultrasonic waves through coagulating milk were continuously monitored. The observed changes in ultrasonic velocity during coagulation were used to predict the coagulation time. The coagulation time is indicative of the transition from the enzymatic phase to the physicochemical phase. The determination of coagulation time has a decisive role in determining the qualities of the end product in cheesemaking.
Financial states of world financial and commodities markets around sovereign debt crisis

We applied a threshold method to construct a complex network from cross-correlations coefficients of 46 daily time series comprised of 23 global indices and 23 commodity futures from 2010 - 2014. We identify financial states of both global indices and commodity futures based on the change of the network structure. The trend of the average correlation is decreasing except sharp peak during crises during the study period. The threshold networks are generated at a threshold value of θ = 0.1 and the change of degrees of each node over time is used to identify the financial state for each index. We observe that commodity futures, such as EU CO2 emission, live cattle, natural gas as well as the financial indices of Jakarta and Indonesia stock exchange (JKSE) and Kuala Lumpur stock exchange (KLSE) change states frequently. By the average change in links we identify the indices which are more reactive to crises.
Divergence Form Operators on Fractal-like Domains

We consider elliptic operators L in divergence form on certain domains in Rd with fractal volume growth. The domains we look at are pre-Sierpinski carpets, which are derived from higher dimensional Sierpinski carpets. We prove a Harnack inequality for non-negative L-harmonic functions on these domains and establish upper and lower bounds for the corresponding heat equation.
An upside-down normal loss function-based method for quality improvement

Traditional measures of process quality do not offer much information on how much better or worse a process is when finding optimal settings of a given problem. The upside-down normal loss function (UDNLF) is a weighted loss function that provides a more reasonable risk assessment to the losses of being off-target in product engineering research. The UDNLF can be used in process design and optimization to accurately reflect and quantify the losses associated with the process in a way which minimizes the expected loss of the upside-down normal (UDN). The function has a scale parameter which can be adjusted by the practitioners to account for the actual percentage of materials failing to work at specification limits. In this article, the ‘target is best’ case is addressed to estimate the expected loss of UDN due to variation from target in the robust process design and response surface modelling context. An approach is proposed to find the control factor settings of a system by directly minimizing the expected loss. The procedure and its merits are illustrated through an example.
Type 2 Subdirectly Irreducible Algebras in Finitely Decidable Varieties

Abstract Let V be a finitely decidable variety and A ∈ V a finite subdirectly irreducible algebra with a type 2 monolith μ. We prove that (1) the solvable radical ν of A is the centralizer of μ (2) ν is abelian, i.e., every solvable congruence of A is abelian; (3) the interval sublattice I[ν, 1A] ⊆ Con A is linear, and typ{ν, aA} ∈ {3}.
Nacelle Interaction with Natural Wind Before Take-Off

To understand how natural wind close to the ground interacts with a jet engine, tests have been completed with a 1/20-scale model fan and intake rig operating within a simulation of the lower atmospheric boundary layer. Unsteady measurements are used to confirm that turbulence in the ambient flow is attenuated as the intake is approached, and analysis of unsteady pressure data reveals that the nacelle surface pressure field is most sensitive to large length-scale gusts. A new statistical approach to analyze intermittent intake separation is used to show that there is hysteresis in the unsteady separation and reattachment of the inlet flow and that there are similarities between the unsteady and steady intake performance. These findings suggest that the intake response to natural wind can be described as quasi steady, and a novel probabilistic model of nacelle behavior is devised based on this hypothesis. The model shows that by combining some statistical characteristics of the wind with the steady intake performance it is possible to synthesize the observed unsteady performance. This confirms that the intake response can be treated in a quasi-steady manner, and this has significant practical implications for engine intake testing and design.
Third-Order Optical Nonlinearities in Thin Films of CdS Nanocrystals

The non-resonant nonlinear optical properties of CdS nanocrystals (NCs) embedded in silica (i) and forming matrix-free (MF) almost close-packed films (ii) were studied using the Z-scan technique. Among the group (i), samples containing NCs covered with a HgS and CuS shell were investigated. The highest value of the nonlinear refractive index n2 1⁄4 1.85 10– 6 cm2/W was measured for the MF films. This number exceeds by far the value typical for bulk CdS and cannot be explained in terms of thermally induced nonlinearity. Strong enhancement of local fluctuations of the electro-magnetic field in MF films where NCs form aggregates or clusters is suggested to explain this result. Within the group (ii), an enhancement of the nonlinearity was observed under pulsed irradiation for both CdS/HgS and CdS/CuS nanoparticles, compared to CdS NCs without a shell.
Journal writing: enlivening elementary linear algebra

ABSTRACT This paper examines the various issues surrounding the implementation of journal writing in an undergraduate linear algebra course. A discussion of sample journal entries and an interactive sequence of messages between an instructor and a student are presented first. Then, using these representatives as a backdrop, issues are raised concerning the journaling process with particular attention paid to questions concerning individual or corporate responses, prompts, and openness. Finally, the benefits of incorporating journal writing into an undergraduate mathematics course are identified and supported with students' comments from their journals and their reflections on the process. The identified benefits include: (a) opening lines of communication; (b) personalizing the learning environment; (c) organizing ideas; and (d) self-evaluating learning. As a result, evidence provided in this paper forms a case for the inclusion of writing activities, specifically journaling, in advanced undergraduate mat.
Large-scale structural effects in developed turbulent flow through closely-spaced rod arrays

Axial and azimuthal turbulence intensities in the rod-gap region are shown, for developed turbulent flow through parallel rod arrays, to increase strongly with decreasing rod spacing. Two array geometries are reported: one was constructed from a rectangular cross-section duct containing four rods and spaced at five pitch-to-diameter or wall-to-diameter ratios; the second was a test section containing six rods set in a regular square-pitch array to represent the interior flow region of a large array. Measurements were made of the mean axial velocity, wall-shear-stress variation, axial-pressure distribution and Reynolds stresses. Techniques for resolving secondary-flow velocities to within ±1% of the local axial velocity failed to detect significant non-zero mean secondary-flow components. Analysis of the turbulent flow structure showed an energetic azimuthal turbulent-velocity component in the open rod gap for both geometries. The axial turbulent velocity has a coupled large-scale semiperiodic structure, with an antiphase relationship across the rod-gap centre or subchannel boundary. This structure is considered to be generated by an incompressible-flow parallel-channel instability, and, for closely spaced rod arrays, is the dominant process for intersubchannel mass, heat or momentum exchange.
Velocity Spectra in the Unstable Planetary Boundary Layer

Abstract Models for velocity spectra of all three components in the lower half of the unstable PBL are presented. The model spectra are written as a sum of two parts, nS(n) = A(fi, z/zi)w*2 + B(f, z/zi)u*02, a mixed layer part with a stability dependence, and a surface layer part without stability dependence and with negligible influence of z/zi in B in the surface layer; A is independent of z/zi for the horizontal components. The model agrees very well with data for variances, peak frequencies and spectra from the Kansas and Minnesota experiments. Requirements for models of spectra in the upper half of the PBL are outlined qualitatively only.
On Non‐parametric Testing, the Uniform Behaviour of the t‐test, and Related Problems

Abstract. In this article, we revisit some problems in non‐parametric hypothesis testing. First, we extend the classical result of Bahadur & Savage [Ann. Math. Statist. 25 (1956) 1115] to other testing problems, and we answer a conjecture of theirs. Other examples considered are testing whether or not the mean is rational, testing goodness‐of‐fit, and equivalence testing. Next, we discuss the uniform behaviour of the classical t‐test. For most non‐parametric models, the Bahadur–Savage result yields that the size of the t‐test is one for every sample size. Even if we restrict attention to the family of symmetric distributions supported on a fixed compact set, the t‐test is not even uniformly asymptotically level α. However, the convergence of the rejection probability is established uniformly over a large family with a very weak uniform integrability type of condition. Furthermore, under such a restriction, the t‐test possesses an asymptotic maximin optimality property.
MPDATA and grid adaptivity in geophysical fluid flow models

Geophysical flows can profoundly affect human activities. Often characterized by an astonishing range of significant scales and a rich assortment of physical processes, the complexity of such flows generally precludes all but numerical simulation for prediction and understanding—yet even state of the art computational models may be severely challenged by problems such as hurricane intensification. Although a number of significant issues are involved, a major factor is often grid resolution, for which grid adaptivity (GA) can be useful. Our experience has been that MPDATA is particularly well suited for GA. This paper sketches general details of a model that blends MPDATA with continuous GA; highlights a tensor viewpoint of the geometric conservation law; and presents results for both global and regional atmospheric applications. Together, the examples demonstrate the advantages of using GA with MPDATA to resolve fine‐scale features—explicit gravity waves generated by flow over orography. Resolution of these waves (or lack thereof) are shown to affect global climate; furthermore, wave resolution is shown to depend upon the regional atmospheric environment. Finally the regional simulations show a surprising increase in the complexity of the wavefields as resolution is increased to the point of resolving nonhydrostatic effects. Copyright © 2005 John Wiley & Sons, Ltd.
The Misdirected Central Engine of the Hyperluminous Infrared Galaxy and Type 2 QSO IRAS P09104+4109

Hubble Space Telescope Wide-Field Planetary Camera 2 imaging polarimetry of the hyperluminous infrared galaxy (and misdirected QSO) IRAS P09104+4109 reveals a highly polarized (p≈20%) giant (~5 kpc) bipolar reflection nebula centered on the nucleus. This, together with our previous detection of broad, polarized Mg II and newly detected broad, polarized Balmer emission lines in our ground-based spectropolarimetry, confirms that the lobes of the nebula are dominated by scattered light from the misdirected QSO and that the object would be indistinguishable from typical luminous QSOs if viewed from either pole. Comparison with previously published narrowband images in the light of [O III] λλ4959, 5007 and [O II] λ3727 shows that the northern lobe of the nebula is coincident with the ionization cone, thus the same light that impinges on the scattering material also ionizes the narrow-line gas. The biconical structure and high polarization suggest that the central UV continuum source is surrounded by a dusty torus of half-opening angle ~23° inclined ~37° with respect to our line of sight. The radio structure of this radio-intermediate object also indicates a long-lived axisymmetry to the central power source, but with a different axis relative to the scattering bicone. We propose that this difference in axes betrays the history of a cataclysmic event that altered the fundamental orientation of the central engine—the bicone defines the current axis of the system. Radio-emitting plasma is beginning to move outward along this new axis, depriving the old radio lobes of power. IRAS P09104+4109 is the first radio-quiet/intermediate object of QSO luminosity and hidden broad lines to show direct evidence that the axisymmetric torus inferred to exist in many Seyfert nuclei is also present in objects of high luminosity.
Exact Variance of Combined Inter- and Intra-Block Estimates in Incomplete Block Designs

Abstract This article presents methods for evaluating exact variance of combined inter- and intra-block estimates of treatment effects in incomplete block designs. The results are valid for all incomplete block designs and hold for a wide class of combined estimates including most in the literature. Tables of exact variance for some estimates are presented for some balanced designs and for some partially balanced designs.
Protection against outliers in empirical bayes estimation

The proven optimality properties of empirical Bayes estimators and their documented successful performance in practice have made them popular. Although many statisticians have used these estimators since the landmark paper of James and Stein (1961), relatively few have proposed techniques for protecting them from the effects of outlying observations or outlying parameters. One notable series of studies in protection against outlying parameters was conducted by Efron and Morris (1971, 1972, 1975). In the fully Bayesian case, a general discussion on robust procedures can be found in Berger (1984, 1985). Here we implement and evaluate a different approach for outlier protection in a random-effects model which is based on appropriate specification of the prior distribution. When unusual parameters are present, we estimate the prior as a step function, as suggested by Laird and Louis (1987). This procedure is evaluated empirically, using a number of simulated data sets to compare the effects of the step-function prior with those of the normal and Laplace priors on the prediction of small-area proportions. Les estimateurs bayesiens empiriques sont des outils largement utilises en raison de leurs proprietes d'optimalite bien etablies et de leur bon rendement en pratique. Peu de techniques ont ete suggerees pour la protection de ces estimateurs contre les effets d'observations aberrantes ou de parametres aberrants, en depit de leur utilisation par de nombreux statisticiens depuis rarticle repere de James et Stein (1961). Une importante serie d'etudes concernant la protection contre les parametres aberrants fut menee par Efron et Morris (1971, 1972, 1975). On trouve dans Berger (1984, 1985) une presentation generale sur les procedures robustes dans le contexte purement bayesien. Dans cet article, nous utilisons et evaluons une approche differente pour la protection contre les valeurs aberrantes dans un modele a effets aleatoires. Celle-ci est fondee sur une specification appropriee de la distribution a priori. Lorsque des parametres inhabituels sont presents, nous estimons la distribution a priori par une fonction en escalier, comme l'ont suggere Laird et Louis (1987). Cette procedure est evaluee empiriquement, en utilisant un certain nombre d'ensembles de donnees simulees. Nous comparons les effets de la loi a priori en escalier a ceux des lois a priori gaussienne et de Laplace, sur la prevision de proportions pour de petites regions.