Miracle-dz/UniFAR-FTUs huggingface dataset:
Portable optical spectroscopy for accurate analysis of ethane in exhaled breath

We report on a maintenance-free, ward-portable, tunable diode laser spectroscopy system for the ultra-sensitive detection of ethane gas. Ethane is produced when cellular lipids are oxidized by free radicals. As a breath biomarker, ethane offers a unique measure of such oxidative stress. The ability to measure real-time breath ethane fluctuations will open up new areas in non-invasive healthcare. Instrumentation for such a purpose must be highly sensitive and specific to the target gas. Our technology has a sensitivity of 70 parts per trillion and a 1 s sampling rate. Based on a cryogenically cooled lead-salt laser, the instrument has a thermally managed closed-loop refrigeration system, eliminating the need for liquid coolants. Custom LabVIEW software allows automatic control by a laptop PC. We have field tested the instrument to ensure that target performance is sustained in a range of environments. We outline the novel applications underway with the instrument based on an in vivo clinical assessment of oxidative stress.
A comparison of the performance of the 3-D super-ensemble and an ensemble Kalman filter for short-range regional ocean prediction

This study compares the ability of two approaches integrating models and data to forecast the Ligurian Sea regional oceanographic conditions in the short-term range (0–72 hours) when constrained by a common observation dataset. The post-processing 3-D super-ensemble (3DSE) algorithm, which uses observations to optimally combine multi-model forecasts into a single prediction of the oceanic variable, is first considered. The 3DSE predictive skills are compared to those of the Regional Ocean Modeling System model in which observations are assimilated through a more conventional ensemble Kalman filter (EnKF) approach. Assimilated measurements include sea surface temperature maps, and temperature and salinity subsurface observations from a fleet of five underwater gliders. Retrospective analyses are carried out to produce daily predictions during the 11-d period of the REP10 sea trial experiment. The forecast skill evaluation based on a distributed multi-sensor validation dataset indicates an overall superior performance of the EnKF, both at the surface and at depth. While the 3DSE and EnKF perform comparably well in the area spanned by the incorporated measurements, the 3DSE accuracy is found to rapidly decrease outside this area. In particular, the univariate formulation of the method combined with the absence of regular surface salinity measurements produces large errors in the 3DSE salinity forecast. On the contrary, the EnKF leads to more homogeneous forecast errors over the modelling domain for both temperature and salinity. The EnKF is found to consistently improve the predictions with respect to the control solution without assimilation and to be positively skilled when compared to the climatological estimate. For typical regional oceanographic applications with scarce subsurface observations, the lack of physical spatial and multivariate error covariances applicable to the individual model weights in the 3DSE formulation constitutes a major limitation for the performance of this multi-model-data fusion approach compared to conventional advanced data assimilation strategies.
Single-shot two-channel Talbot interferometry using checker grating and Hilbert-Huang fringe pattern processing

Diffraction efficiency and image processing enhanced two-dimensional Talbot shearing interferometry providing phase object derivative information in two mutually orthogonal directions is proposed. The properties of the Talbot interferometer using amplitude checker grating are studied and its performance is compared with a common configuration based on the cross-type amplitude Ronchi grids. Besides the light output gain further setup attractiveness is related to conducting the automatic fringe pattern analysis guided by recently introduced Hilbert-Huang processing for single exposure two-dimensional grating interferometry. The checker grating self-image deformed by the object under test is resolved into two linear fringe families running in 45/135 deg directions with respect to checker grating lines. Next the separated fringe sets are filtered using automatic selective reconstruction aided by enhanced fast empirical mode decomposition and mutual information detrending. Finally the Hilbert spiral transform is implemented to retrieve phase maps representing first derivatives of the object phase distribution. Efficient adaptive digital filtering enables analysis of complex patterns without resorting to coherent spatial filtering resulting in complicated and bulky experimental setups. Numerical and experimental studies corroborate the robustness and versatility of the proposed approach.
Closed universes: their future evolution and final state

On montre que l'existence d'une hypersurface maximale (un temps d'expansion maximum) est une condition necessaire et suffisante pour l'existence d'une singularite finale dans un Univers avec une surface de Cauchy compacte. Les seules topologies qui peuvent admettre des hypersurfaces maximales sont S 3 et S 2 ×S 1 ainsi que des topologies plus compliquees formees a partir de ces deux types. On discute de l'application de ces resultats a l'inflation
In-plane aligned YBCO thick films grown in situ by high temperature ultrasonic spray pyrolysis

Ultrasonic spray pyrolysis (USP) has been used to deposit thick films (up to 5 micron) of YBa2Cu3O7-x in situ on single-crystal oxide substrates, and single-crystal and textured polycrystalline Ag foil of different orientations. Epitaxial films grow with a strong level of in-plane texture on the single crystal oxide substrates (<3° full width at half maximum) and on (100) and (110) oriented Ag. Films grown under optimized conditions have onset Tc of 91 K with transition widths of ~ 6 K. The films are fully connected and Jc are ~ 1.0×104A cm-2 at 77 K and ~ 5×105A cm-2 at 20 K.
Behaviour of laser-produced high-β plasmas in a spindle-cusp magnetic container

Detailed experimental measurements have been made of the time-dependent behaviour of high- beta plasmas ( beta <or approximately=0.6) produced by a focused laser beam irradiating thin solid target wires of polyethylene or aluminium at the null-field of a spindle-cusp magnetic container. The ring cusp width is shown to increase from 0.6 to 2.9 times the local ion gyro-radius as the value of plasma beta decreases from 0.6 to below 0.2 during the confinement phase. The re-thermalisation of particle energy in the cusp container, the relatively rapid penetration of magnetic fields into the cusp plasma volume, and the containment properties of spindle-cusps for high- beta plasmas are discussed.
Search Games with Mobile and Immobile Hider

We consider search games in which the searcher moves along a continuous trajectory in a set Q until he captures the hider, where Q is either a network or a two (or more) dimensional region. We distinguish between two types of games; in the first type which is considered in the first part of the paper, the hider is immobile while in the second type of games which is considered in the rest of the paper, the hider is mobile. A complete solution is presented for some of the games, while for others only upper and lower bounds are given and some open problems associated with those games are presented for further research.
Experimental and Numerical Study of Stationary Throat Plug in Shock Tunnel

A throat plug is a device in a shock tunnel to prevent fragments, produced by the bursting of the primary diaphragm, from entering the nozzle and damaging the model. In the present study, a series of experimental and numerical studies has been carried out to investigate the flows around stationary throat plugs in a shock tunnel. For this purpose, conical, circular, and double circular stationary throat plugs that have a 19.4% areal blockage were used as the test models. The primary shock velocity was set at 1.19 km/s, and the shock generated a tailored condition when helium and air were used as the driver and driven gases at room temperature. In the experiment, the nozzle reservoir pressure and the pitot pressure at the nozzle exit were measured to examine the influence of the throat plug. It was found that, from both the experiment and the calculation, all types of the plugs generate a pressure bump in the nozzle reservoir during the transient period of interaction between the reflected shock and the pl.
Cup products and group extensions

Abstract Let G be a finitely generated group and let R be a commutative ring, regarded as a G-module with G acting trivially. We shall determine when the cup product of two elements of H1(G, R) is zero. Our method will use the interpretation of H2(G, R) as extensions of G by R. This will give an alternative demonstration of results of Hillman and Würfel.
Electron transit time and reliable mobility measurements from thick film hydroxyquinoline-based organic light-emitting diode

The time delay (τd) in the transient electroluminescence (EL) signal of a bilayer organic light-emitting diode with a structure of indium-tin oxide /N,N′-diphenyl-N,N′-bis(3methylphenyl)-(1,1′-biphenyl)-4,4′-diamine /tris(8-hydroxyquinoline) aluminum (Alq3)/Al has been measured and analyzed as a function of the thickness (D) of the Alq3 layer. For a thin layer of Alq3 (D 200 nm), τd approaches the intrinsic electron transit time through Alq3. Electron mobility of Alq3 can be evaluated for the thick-film devices and the results are in excellent agreement with independent time-of-flight measurements. The application of transient EL in mobility measurement for C540-doped Alq3 is discussed.
Translational motion of a bubble undergoing shape oscillations

This paper studies the nonlinear coupling between the volume pulsation, translational motion and shape modes of an oscillating bubble, especially in the context of translational instability, known as ‘dancing motion’, that is demonstrated by bubbles in acoustic standing waves. A set of coupled equations is derived that describes volume pulsations of a bubble, its translational motion and shape oscillations evolving on the bubble surface. The amplitudes of the surface modes and the translational velocity of the bubble are assumed to be small and allowed for in the equations of motion up to only second-order terms. The amplitude of the volume oscillation is not limited. Unlike earlier work on this subject, where only two adjacent shape modes with given natural frequencies are taken into account, we allow for all shape modes and do not impose any limitations on their natural frequencies. As a result, the present analysis reveals additional features, which have not been noted previously, inherent in the mutual interactions of the shape modes as well as in the interaction between the shape modes and the translational motion.
Empirical sigma - d relations and main galactic radio loops

This paper represents a review of the empirical Galactic and extragalactic sigma - D relations (relations between the surface brightness sigma and the diameter D) for supernova remnants (SNRs), with checking the connection of the main Galactic radio loops (Loop I, II, III and IV) with these relations. We present results which suggest, in another way, that the radio loops may have an SNR origin. The updated relations have been measured to have slopes beta = 2 in log-log space. The best sigma - D relations for M31 and M33 galaxies were derived and these relations are shown to be flatter (beta < 2) than those for Galactic SNRs alone. This result confirms that selection effects play an important role in data-sets made up of Galactic SNRs. A sigma - D relation with 157 reliable calibrators (both Galactic and extragalactic) is derived. This relation also has a slope beta = 2.07 ± 13.
HOCUS: The Haskins optically-corrected ultrasound system for measuring speech articulation

The tongue is the most important supralaryngeal articulator for speech, yet, because it is typically out of view, its movements have been difficult to quantify. Here is described a new combination of techniques involving ultrasound in conjunction with an optoelectric motion measurement system (Optotrak). Combining these, the movements of the tongue are imaged and simultaneously corrected for motion of the head and of the ultrasound transceiver. Optotrak’s infrared‐emitting diodes are placed on the transceiver and the speakers head in order to localize the ultrasound image of the tongue relative to the hard palate. The palate can be imaged with ultrasound by having the ultrasound signal penetrate a water bolus held against the palate by the tongue. This trace is coregistered with the head and potentially with the same talker’s sagittal MR image, to provide additional information on the unimaged remainder of the tract. The tongue surface, from the larynx to near the tip, can then be localized in relationship to the hard palate. The result is a fairly complete view of the tongue within the vocal tract at sampling rates appropriate for running speech. A comparison with other imaging vocal tract systems will be presented. [Work supported by NIH Grant DC‐02717. ]
Active damping of self-excited torsional vibrations in oil well drillstrings

Abstract A drillstring used for the drilling of oil or gas wells behaves as a rotating torsional pendulum. The drillstring is rotated at a constant angular velocity by an electric motor, but exhibits superimposed torsional vibrations caused by a non-linear relationship between torque and angular velocity at the rock-crushing tool. The vibrations are self-excited, and disappear when the mean angular velocity of the pendulum is raised above a threshold value. An active damping system is described that strongly reduces the threshold value by using feedback control, thus extending the working range for vibration-free rotation. It operates at the current and the voltage of the electric motor, and can be implemented with only electrical components. The active damping system is interpreted as an extension of the passive tuned vibration absorber for quenching of self-excited vibrations in the form of a resilient foundation, as described by Tondl (1975Journal of Sound and Vibration42(2), 251–260). The concept of quenching self-excited vibrations by modifying the drive system as described in this paper is directly applicable to other engineering systems which are driven by a separately excited DC motor. Furthermore, the concept can be applied to systems driven by a hydraulic motor with a continuously variable flow rate.
Analysis of asymptotic projectile motion with air resistance using the Lambert W function

We calculate the range of a projectile experiencing air resistance in the asymptotic region of large velocities by introducing the Lambert W function. From the exact solution for the range in terms of the Lambert W function, we derive an approximation for the maximum range in the limit of large velocities. Analysis of the result confirms an independent numerical result observed in an introductory physics class that the angle at which the maximum range occurs, θmax, goes rapidly to zero for increasing initial firing speeds v0≫1. We show that θmax∼(ln v0)/v0.
Exact algorithms for the job sequencing and tool switching problem

The job Sequencing and tool Switching Problem (SSP) involves optimally sequencing jobs and assigning tools to a capacitated magazine in order to minimize the number of tool switches. This article analyzes two integer linear programming formulations for the SSP. A branch-and-cut algorithm and a branch-and-bound algorithm are proposed and compared. Computational results indicate that instances involving up to 25 jobs can be solved optimally using the branch-and-bound approach.
Energetic ring current particles generated by recurring substorm cycles

It is now generally accepted that substorm expansive phase activity involves a release of magnetotail energy, part of which is available for the acceleration of highly energetic particles (E > 100 keV) that play a role in ring current and radiation belt formation. However, the physical process whereby this acceleration takes place is not yet fully understood. In this paper we consider the physics of the acceleration process based on the tenet that acceleration of particles to E >100 keV occurs as a cumulative process involving a sequence of substorm expansive phases. In our view, nonadiabatic particle dynamics plays a key role in the energization process. We present both a qualitative description and quantitative treatment which starts with a consideration of a single particle and is then extended to track the evolution of the particle distribution function over several substorm expansive phase cycles. We stress two salient features of the evolution of particle distribution function, namely the rapid formation of a non-Maxwellian high-energy tail and the saturation of this tail distribution toward a kappa distribution in the asymptotic limit.
Experimental study of rarefied gas flow near sudden contraction junction of a tube

An experimental study of nearly isothermal rarefied gas flow near the sudden contraction junction of a tube is presented in this paper. The measurements are performed with nitrogen gas flowing at low pressures in conventional tubes with sudden contraction area ratios of 1.48, 3.74, 12.43, and 64. The flow is dynamically similar to gas flow in a microchannel as the Knudsen number (0.0001 < Kn < 0.032) falls in the slip flow regime. The Reynolds number in the smaller section (Res) ranges between 0.2 and 837. The static pressure measurements are analyzed to understand the flow behavior. The static pressure variation along the wall and uniform radial pressure profile near the junction indicates absence of flow separation and vena contracta. The static pressure variation in both the tubes approaches the pressure variation as that of an isolated straight tube at a certain critical Knudsen number for a given area ratio. The velocity field is obtained through a momentum balance and using the flow measurements. Th.
High-precision thermal conductivity measurements as a probe of polymer/nanoparticle interfaces

We use the 3ω method to study the thermal conductivity of composites of nanoscale alumina particles in polymethylmethacrylate (PMMA) matrices. Effective medium theory and data for the changes in conductivity produced by low volume fractions of particle fillers are used to estimate the thermal conductance G of PMMA/alumina interfaces in the temperature range of 40<T<280 K. Near room temperature, G≈30±10 MW m−2 K−1 and the critical particle radius, r0=Λ0/G, is extremely small, r0≈7.5±2.5 nm. (Λ0=0.205 W m−1 K−1 is the conductivity of the PMMA matrix.) Therefore, high volume fractions of typical ceramic nanoparticles with r≫r0 can be used in thermal interface materials such as adhesives, pastes, and pads.
Full-wave simulation of enhanced outcoupling of organic light-emitting devices with an embedded low-index grid

Enhancement of light outcoupling into substrate modes by a grid of low-refractive-index material embedded into the organic layer of an organic light-emitting device (OLED) is analyzed using full-wave electromagnetic simulations. The low-index grid (LIG) redirects modes normally trapped within the high-index organic and indium tin oxide layers (waveguide modes) into the substrate where they can be further extracted into free space using methods such as microlens arrays or roughened surfaces. This increases the external quantum and power efficiencies without affecting the electroluminescent spectrum. The dependence on grid geometry, dimensions, and refractive index is explored to optimize the structure. Simulations show that up to 50% more light can be extracted from the high-index region using an ultralow-index (n=1.03) grid than a conventional device, and provided efficient substrate-to-air outcoupling, the external quantum efficiencies of LIG OLEDs can reach >50%.
Collective motions in non-uniformly magnetized plasmas

While the reduced particle and fluid descriptions of magnetized plasma dynamics are based on the same set of approximations they apparently give differing results for the collective motions in non-uniform magnetic fields. Here it is shown that these two pictures give identical results when the diamagnetic effects due to charged particle gyration are taken into account. The subtle kinematical effects of the latter are revealed through many illustrations. Finally, this insight is used to explain the physical mechanism behind the ideal interchange instability. All these topics are intimately connected and have so far not been given an adequate presentation in introductory textbooks.
Excitonic and biexcitonic properties of single GaN quantum dots modeled by 8-band k⋅p theory and configuration-interaction method

Received 2 March 2009; published 26 June 2009 Excitons and biexcitons in GaN/AlN quantum dots (QD) were investigated with special emphasis on the use of these QDs for single-photon source applications. The theoretical methodology for the calculation of single-particle states was based on 8-band strain-dependent envelope function Hamiltonian, with the effects of spin-orbit interaction, crystal-field splitting, and piezoelectric and spontaneous polarizations taken into account. Exciton and biexciton states were found using the configuration-interaction method. Optimal QD heights for their use in single-photon emitters were determined for various diameter to height ratios. The competition between strong confinement in GaN QDs and internal electric field, generally reported in wurtzite GaN, was also discussed, as well as its effect on appearance of bound biexcitons.
Parametrization of the depth of the entrainment zone above the daytime mixed layer

A new parametrization for the depth of the daytime entrainment zone is presented. It is derived from a simple energy budget, in which the eddy velocity in the mixed layer penetrating the overlying stable entrainment zone is taken to be proportional to the characteristic top-down velocity scale. It gives a better ordering of the data of two earlier studies by Deardorff et al. and Boers and Eloranta as compared with traditional parcel theory based on the bottom-up velocity scale. Furthermore, it can be seen that the data from the two studies belong to different regimes of the characteristic scaling parameter.
Process-Based Decomposition of the Global Surface Temperature Response to El Niño in Boreal Winter

AbstractThis paper reports an attribution analysis that quantifies addible contributions to the observed temperature anomalies from radiative and nonradiative processes in terms of both amplitude and spatial pattern for the two most prominent surface temperature patterns in an El Nino winter. One is the El Nino SST pattern consisting of warming SST anomalies over the eastern equatorial Pacific basin surrounded by cooling SST anomalies in the western and subtropical Pacific, and the other is a tripole surface temperature anomaly characteristic of a positive Pacific–North American (PNA) teleconnection pattern. The decomposition of the observed temperature anomalies is achieved with the coupled atmosphere–surface climate feedback-responses analysis method (CFRAM), which is formulated utilizing energy balance in the atmosphere–surface columns and linearization of radiative energy perturbation.Out of the mean amplitude of 0.78 K of the El Nino SST pattern, the oceanic dynamics and heat storage term alone contr.