Miracle-dz/UniFAR-FTUs huggingface dataset:
On the luminosity curves of persons having normal and abnormal colour vision

1. When reading a recent paper before the Royal Society, and also in the Press, Dr. Edridge Green has stated that he can find no connection between the luminosity and the colour sense of persons having either normal or abnormal colour sensations. Since I feel that to allow such a statement to go unchallenged might be interpreted as meaning that no such connection could be shown to exist, I propose in the following paper to place before the Society some of the evidence which indicated that there is in reality a very intimate relation between luminosity and colour sense. The results given include a small part of those which have been obtained in a series of experiments which have occupied the last two years and form part of investigation which is still in progress. The term “luminosity” as used in this paper has the following meaning: Suppose that light from some source, such as the electric arc, is admitted to a spectroscope by means of which a real pure spectrum is produced, and that a slide in the plane in which the spectrum is formed carries a slit of fixed width. Light of sensibly one wave-length, i. e. monochromatic light, will pass through this slit, and by means of a lens placed in the beam of this light an image of the first face of the prism which is used to from the spectrum can be formed on a screen. In this way a monochromatic patch of light is obtained, the brightness of which depends on the nature of the source of light, the width of the collimator slit, the width of the slit placed in the spectrum, which for short will be called the movable slit, and the dimensions of the lenses employed. Further, if alongside this coloured patch is formed a white patch of light produced by light which proceeds from the same source but has not undergone dispersion, and that by some means or other the intensity of this white light is altered till the coloured and white light, measured in any arbitrary units, measure the luminosity of the light of that colour which is passing through the movable slit. Since the unit in which the white light is measured is arbitrary, we are not concerned with the absolute intensity of illumination of the white patch, and may use any device we like to alter the quantity of white light which falls on the screen so long as we are able to measure the ratio of the quantity of light employed in different experiments. It will further be observed that for any given person the measurement of the luminosity of a given coloured light in the spectrum involves the comparsion of the brightness of the coloured patch as it appears to him with the brightness of the white patch as it appears to him.
The Physlet Approach to Simulation Design.

Over the past two years, the AAPT/ComPADRE staff and the Open Source Physics group have published the second edition of Physlet Physics and Physlet Quantum Physics , delivered as interactive web pages on AAPT/ComPADRE and as free eBooks available through iTunes and Google Play. These two websites, and their associated books, add over 1000 interactive exercises for the teaching of introductory physics, introductory and intermediate modern physics, and quantum mechanics to AAPT/ComPADRE.
Experimental and computational modeling of the kinematics and aerodynamics of flapping wing

High-speed videography is used in measuring the kinematic and deformation parameters of the flapping wing. Based on these data, a theoretical analysis of the underlying physics is performed using computational fluid dynamics simulations. The time varying of the pitching angle in the chordwise directions exhibits a significant second harmonic. Results suggest the mechanics of membrane deformations during a flapping cycle is analogous to the buckling of a bistable structure. Noticeably, with an increase in the freestream speed, the downstroke duration increases. The solution to the three-dimensional fluid dynamics problem is constructed using two-dimensional solutions obtained for several sections of the wing by the improved discrete vortex method. The inertial component is dominant in the normal force coefficient, and hence, added mass is the main mechanism in aerodynamic force production for the studied problem. A normal component of the acceleration of the wing’s trailing edge taken with a negative sign .
FUSE Determination of Abundances in Long-Period Pulsating V1093 Her (PG 1716+426) Stars

We present an analysis of the Far Ultraviolet Spectroscopic Explorer (FUSE) spectra of five V1093 Her (PG 1716+426) stars, the subgroup of hydrogen-rich subdwarf B stars that exhibit very low amplitude, long-period luminosity variations. Our primary aim is to investigate whether these stars display abundances which differ from those observed in the nonvariable sdB stars and also in the shorter period V361 Hya variables. For the light elements and for those beyond the iron peak, our abundances are consistent with the trends observed in earlier studies. For the important iron peak elements Ti, V, Cr, Mn, Fe, Co, and Ni, which are thought to be directly linked to the driving mechanism in both long-period and short-period variables, the abundances determined in the V1093 Her stars appear very homogeneous and exhibit mild enrichments (by factors of 2-5 for Cr, Mn, Fe, and Co) over the solar value. However, these abundances do not differ appreciably from those measured in a sample consisting of constant stars and one short-period pulsator. The implications of these findings for current models which involve both diffusion processes and stellar winds to account for the driving of nonradial pulsations in sdB stars are discussed.
Electrically driven vortices in a weak dipolar magnetic field in a shallow electrolytic layer

Steady dipolar vortices continuously driven by electromagnetic forcing in a shallow layer of an electrolytic fluid are studied experimentally and theoretically. The driving Lorentz force is generated by the interaction of a dc uniform electric current injected in the thin layer and the non-uniform magnetic field produced by a small dipolar permanent magnet (0.33 T). Laminar velocity profiles in the neighbourhood of the zone affected by the magnetic field were obtained with particle image velocimetry in planes parallel and normal to the bottom wall. Flow planes at different depths of the layer were explored for injected currents ranging from 10 to 100 mA. Measurements of the boundary layer attached to the bottom wall reveal that owing to the variation of the field in the normal direction, a slightly flattened developing profile with no shear stresses at the free surface is formed. A quasi-two-dimensional magnetohydrodynamic numerical model that introduces the non-uniformity of the magnetic field, particularly its decay in the normal direction, was developed. Vertical diffusion produced by the bottom friction was modelled through a linear friction term. The model reproduces the main characteristic behaviour of the electromagnetically forced flow.
Negative Magnetoresistance in Homogeneous Amorphous Superconducting Pb Wires

We report systematic magnetotransport measurements on a series of {ital in situ} grown homogeneous amorphous Pb wires. Corresponding to the broadening of the superconducting transitions as the wires cross over from 2D to 1D, we observe a {ital negative} magnetoresistance (MR) below the mean-field T{sub c} at low fields. Both the magnitude of the negative MR and the crossover field increase with decreasing T{sub c} and wire cross-sectional area. We speculate that these observations are the result of superfluid density fluctuations in sign as well as in magnitude along these wires close to the superconductor-insulator transition. {copyright} {ital 1997} {ital The American Physical Society}
Turbulent single-photon propagation in the Canary optical link

The role of turbulence for Quantum Communications (QC) has been investigated in a 143 km-long link. The analysis of the received signal temporal domain indicate how to exploit constructively its effects in the case of QC along very long free-space links as well satellite links. Novel applications with relevant background noise may be envisaged.
Corneal biomechanical properties from air-puff corneal deformation imaging

The combination of air-puff systems with real-time corneal imaging (i.e. Optical Coherence Tomography (OCT), or Scheimpflug) is a promising approach to assess the dynamic biomechanical properties of the corneal tissue in vivo. In this study we present an experimental system which, together with finite element modeling, allows measurements of corneal biomechanical properties from corneal deformation imaging, both ex vivo and in vivo. A spectral OCT instrument combined with an air puff from a non-contact tonometer in a non-collinear configuration was used to image the corneal deformation over full corneal cross-sections, as well as to obtain high speed measurements of the temporal deformation of the corneal apex. Quantitative analysis allows direct extraction of several deformation parameters, such as apex indentation across time, maximal indentation depth, temporal symmetry and peak distance at maximal deformation. The potential of the technique is demonstrated and compared to air-puff imaging with Scheimpflug. Measurements ex vivo were performed on 14 freshly enucleated porcine eyes and five human donor eyes. Measurements in vivo were performed on nine human eyes. Corneal deformation was studied as a function of Intraocular Pressure (IOP, 15-45 mmHg), dehydration, changes in corneal rigidity (produced by UV corneal cross-linking, CXL), and different boundary conditions (sclera, ocular muscles). Geometrical deformation parameters were used as input for inverse finite element simulation to retrieve the corneal dynamic elastic and viscoelastic parameters. Temporal and spatial deformation profiles were very sensitive to the IOP. CXL produced a significant reduction of the cornea indentation (1.41x), and a change in the temporal symmetry of the corneal deformation profile (1.65x), indicating a change in the viscoelastic properties with treatment. Combining air-puff with dynamic imaging and finite element modeling allows characterizing the corneal biomechanics in-vivo.
A Bayesian solution to the problem of state estimation in an unknown noise environment

Abstract The problem of estimation of the state of a linear dynamic system driven by white Gaussian noise with unknown covariance Q and observed by a linear function of the state contaminated by white Gaussian noise with unknown covariance R is considered. Bayesian recursion relations for the probability densities of the unknown random variables conditioned on all available data are developed. Initially a relation giving the a posteriori densities of Q and R conditioned on all available data is developed. However since the possible range of Q and R is generally unbounded and also because Q and R may have quite large dimension, a mechanization of the aforesaid algorithm by representing Q and R with a grid of possible values is considered unfeasible for any realistic problems. Therefore, the random variables Q and R are transformed to random variables representing the optimal gain and the covariance of the innovations process by use of the steady state Kalman filter relations. The resulting probability dens.
Rigid levitation and suspension of high‐temperature superconductors by magnets

A high‐Tc superconductor floating freely above a magnet of low symmetry remains rigidly suspended in the air in almost any position and orientation as if stuck in an invisible heap of sand. This striking effect is due to pinning of the magnetic flux lines inside the superconductor and is often overlooked, since usually magnets with rotational symmetry are used for levitation. Magnets with rotational symmetry allow for nearly undamped orbiting and rotation of the superconductor about the magnet’s symmetry axis. But even in this geometry, flux‐line pinning can be seen, since it forces the orbiting superconductor to turn the same face toward the axis. Superconductors with sufficiently strong pinning may even be suspended below a magnet.
Free vibrations of beams accounting for refined theories and radial basis functions

The free vibration response analysis of beams with arbitrar y cross-sections and geometrical boundary conditions consists of one of the most classical problem of dynamics of c ontinuum systems. Depending on the beam length as well as on the geometrical characteristics of the cross-sec tion, classical beam theories neglecting (Euler-Bernoull i) and accounting (Timoshenko) for transverse shear deformation can lead to inaccurate results, especially in those cases in which vibration modes involving significant cross-section defor mations are of interest. The use of refined theories, which ar e able to accurately detect in-plane deformations and warpin g, is therefore mandatory in many practical problems relate d to the high-frequency response analysis and thin-walled beam s. In this work, one-dimensional refined theories are develo ped on the basis of the Unified Formulation (UF), which was recent ly i roduced by the authors [1]. Closed-form exact solutions of governing equations relate d to free vibration analysis are available only for a few case s of boundary conditions. Therefore, to obtain the solutions fo r a wide range of problems, adequate approximated/numerica l methods have to be developed, see [2]. Numerical methods can be classified as meshless and mesh-based methods. Among the latter, the finite element method (FEM) is probably the mo st p pular. FEM, as well as any other method introducing a finite discretization of the problem domain, reveals by defi nition deficiencies in the evaluation of the high-frequency response, which plays a fundamental role in many practical p roblems such as wave propagation and vibro-acoustics. The use of meshless methods is mandatory in these cases. Among th e many available meshless methods, the radial basis functions (RBF) method is considered in this work to investi gate the free vibration characteristics of beams by account ing for refined theories developed on the basis of UF. In the recen t past, authors applied RBF and UF to plate and shell problems and encouraging results were obtained [3]. A few de tails on the technique adopted are outlined below.
Quantized electronic structure and growth of Pb films on highly oriented pyrolytic graphite

We have measured the electronic structure of thin Pb films grown on highly oriented pyrolytic graphite (HOPG) by angle-resolved photoemission spectroscopy. Quantum well states (QWSs) corresponding to confined Pb valence electrons are observed. Their energy positions are fixed, but their intensities evolve for increasing Pb coverages. The results indicate that the films are rough, consisting of multiple thicknesses. Nevertheless, the thickness distribution is sufficiently narrow to allow a unique assignment for each QWS peak in terms of a quantum number and the exact film thickness in atomic layers. For increasing Pb coverages of up to 10 monolayers (ML), the even film thicknesses of 2, 4, 6, 8, and 10 ML are much more prevalent than the odd film thicknesses of 1, 3, 5, 7, and 9 ML, thus suggesting significant differences in surface energy between the even and odd thicknesses. These results are consistent with an available first-principles calculation of the surface energies of freestanding films; an implication is that the interaction between the Pb film and the HOPG substrate is weak. The in-plane dispersion relations of the QWSs are measured. The effective masses at the surface zone center agree well with the results calculated from the bulk Pb band structure, in sharp contrast to the strongly enhanced or anomalous effective masses in Pb films grown on Si(111) as reported previously. This finding indicates that the anomalous effective masses in Pb/Si(111) are not caused by increased electron correlation effects in a confined geometry, but are rather attributable to a strong interfacial interaction between the QWSs and the substrate electronic structure.
Development of a Nb_3AI Conductor to be Applied to a Fusion Reactor and Its Application to a Large Superconducting Coil

The Japan Atomic Energy Research Institute has been involved in developing Nb3Al conductors since the middle of 1980s based on the consideration that Nb3Al conductors are capable of producing a higher magnetic field than Nb3Sn conductors owing to the extremely high critical current density in high magnetic fields. At the beginning of the development work, a fabrication technique for Nb3Al strands using a Jelly-roll process was established. This process requires heat treatment at 750°C for 50 h instead of a temperature of more than 1,800°C as required by the conventional method. Using this technique, about 1 ton of strands was produced and a 150-m Nb3Al cable-in-conduit conductor was fabricated. For the next step, to demonstrate the applicability of the Nb3Al conductor to a large coil, a coil 1.5-m in diameter, called the Nb3Al Insert, was manufactured. A react-and-wind method was tried for the production process as it simplifies the fabrication of large coils such as an ITER-TF coil. Performance tests of the Nb3Al Insert were conducted in 2002. The Nb3Al Insert could be charged to the designed point of 13 T and 46 kA without showing any instability. Thus, the world's first large superconducting coil using a Nb3Al conductor was successfully developed, thus indicating the possibility of producing fusion magnets that can operate in higher magnetic fields than those used with Nb3Sn conductors.
Postprocessing of Ensemble Weather Forecasts Using a Stochastic Weather Generator

This study proposes a new statistical method for postprocessing ensemble weather forecasts using a stochastic weather generator. Key parameters of the weather generator were linked to the ensemble forecast means for both precipitation and temperature, allowing the generation of an infinite number of daily times series that are fully coherent with the ensemble weather forecast. This method was verified through postprocessing reforecast datasets derived from the Global Forecast System (GFS) for forecast leads ranging between 1 and 7 days over two Canadian watersheds in the Province of Quebec. The calibration of the ensemble weather forecasts was based on a cross-validation approach that leaves one year out for validation and uses the remaining years for training the model. The proposed method was compared with a simple bias correction method for ensemble precipitation and temperature forecasts using a set of deterministic and probabilistic metrics. The results show underdispersion and biases for the raw GFS ensemble weather forecasts, which indicated that they were poorly calibrated. The proposed method significantly increased the predictive power of ensembleweatherforecastsforforecastleadsrangingbetween1and7days,andwasconsistentlybetterthanthe bias correction method. The ability to generate discrete, autocorrelated daily time series leads to ensemble weather forecasts’ straightforward use in forecasting models commonly used in the fields of hydrology or agriculture. This study further indicates that the calibration of ensemble forecasts for a period up to one week is reasonable for precipitation, and for temperature it could be reasonable for another week.
A Survey of the Pisces-Perseus Supercluster. VI. The Declination Zone +15.5 degrees to n+21.5 degrees

New results are presented of Arecibo observations in the 21 cm line of 765 galaxies with declinations between 15.5° and 21.5°, in the Pisces-Perseus supercluster zone. If considered independently on the neighboring parts of sky, this region, to the South of the supercluster ridge, shows significantly less evidence of structure on large scales in excess of 30 Mpc, contrasting substantially with the characteristics of the declination zones immediately to the North
Hot spots in the microwave sky

Tha assumption that the cosmic background fluctuations can be approximated as a random Gaussian field implies specific predictions for the radiation temperature pattern. Using this assumption, the abundances and angular sizes are calculated for regions of various levels of brightness expected to appear in the sky. Different observational strategies are assessed in the context of these results. Calculations for both large-angle and small-angle anisotropy generated by scale-invariant fluctuations in a flat universe are presented. Also discussed are simple generalizations to open cosmological models. 21 references.
Large scale motions in electrical discharges

Mass motions of a plasma are numerically analyzed for a discharge from a central small screen electrode of circular cross section and two other screen electrodes covering the two ends of a circular tube. In effect, there are two oppositely directed discharges from the central electrode and this simplifies the analysis. Rotational electromagnetic forces cause two large eddies, each with a region of high velocity or a jet on either side of the central electrode. The case is further computed where the plasma is allowed to flow from one end to the other through the tube and the screen electrodes. The plasma entering the end screen electrode flows around the eddy lying between the electrode and the central electrode. This provides a recirculating and confined motion associated with the first discharge. As the plasma flows farther downstream, it is drawn to the axis of the second discharge and becomes a part of its jet.
Energy-delay complexity of asychronous circuits

In this thesis, a circuit-level theory of energy-delay complexity is developed for asynchronous circuits. The energy-delay efficiency of a circuit is characterized using the metric Et^n , where E is the energy consumed by the computation, t is the delay of the computation, and n is a positive number that reflects a chosen trade-off between energy and delay. Based on theoretical and experimental evidence, it is argued that for a circuit optimized for minimal Et^n, the consumed energy is independent, in first approximation, of the types of gates (NAND, NOR, etc.) used by the circuit and is solely dependent on n and the total amount of wiring capacitance switched during computation. Conversely, the circuit speed is independent, in first approximation, of the wiring capacitance and depends only on n and the types of gates used. The complexity model allows us to compare the energy-delay efficiency of two circuits implementing the same computation. On the other hand, the complexity model itself does not say much about the actual transistor sizes that achieve the optimum. For this reason, the problem of transistor sizing of circuits optimized for Et^n is investigated, as well. A set of analytical formulas that closely approximate the optimal transistor sizes are explored. An efficient iteration procedure that can further improve the original analytical solution is then studied. Based on these results, a novel transistor-sizing algorithm for energy-delay efficiency is introduced. It is shown that the Et^n metric for the energy-delay efficiency index n ≥ 0 characterizes any optimal trade-off between the energy and the delay of a computation. For example, any problem of minimizing the energy of a system for a given target delay can be restated as minimizing Et^n for a certain n. The notion of minimum-energy function is developed and applied to the parallel and sequential composition of circuits in general and, in particular, to circuits optimized through transistor sizing and voltage scaling. Bounds on the energy and delay of the optimized circuits are computed, and necessary and sufficient conditions are given under which these bounds are reached. Necessary and sufficient conditions are also given under which components of a design can be optimized independently so as to yield a global optimum when composed. Through these applications, the utility of the minimum-energy function is demonstrated. The use of this minimum-energy function yields practical insight into ways of improving the overall energy-delay efficiency of circuits.