Miracle-dz/UniFAR-FTUs huggingface dataset:
NUMERICAL PREDICTION OF SEMI-CONFINED JET IMPINGEMENT AND COMPARISON WITH EXPERIMENTAL DATA

SUMMARY The standard k-c eddy viscosity model of turbulence in conjunction with the logarithmic law of the wall has been applied to the prediction of a fblly developed turbulent axisymmetric jet impinging within a semi-conbed space. A single geometry with a Reynolds number of 20,000 and a nozzle-to-plate spacing of two diameters has been considered with inlet boundary conditions based on measured profiles of velocity and turbulence. Velocity, turbulence and heat transfer data have been obtained using laser-Doppler anemometry and liquid crystal thermography respectively. In the developing wall jet, numerical results of heat transfer compare to within 20% of experiment where isotropy prevails and the trends in turbulent kinetic energy are predicted. However, stagnation point heat transfer is overpredicted by about 300%, which is attributed directly to the turbulence model and inapplicability of the wall function. Jet impingment flows are frequently used in industrial practice for their high heat and mass transfer rates. Their employment is common but also diverse and typical applications include many heating, cooling and drying processes such as the manufacture of printed wiring boards, printing processes, production of foodstuffs, de-icing of aircraft wings and cooling of turbine aerofoils. The high heat transfer rates are especially needed to achieve short processing times for product quality or owing to temporal limitations of the process and/or for energy efficiency. The fluid dynamic structure of such processes is extremely complex and as such it is often reduced to that of understanding a single impinging jet, which will be turbulent except at very low Reynolds numbers. Even when the practical application is simplified, the necessary experimental rigs can be cumbersome and expensive, not to mention the time-consuming data acquisition, validation and analysis. Numerical simulations are an alternative to the experimental approach and can provide a fast and economic solution which will describe the flow or at least identify trends in the flow or heat transfer distribution. In this case the designer needs to be aware of the reliability and limitations of the numerical solutions for that particular geometry under investigation. An assessment of the model can only be obtained by comparison with experiment. Since numerical solutions are problem-dependent, there is a need for reliable experimental data specific to the jet impingement geometry to facilitate a direct assessment.
Subpicosecond laser timing stabilization

The 0.25 Hz-25 kHz pulse timing fluctuations of a Nd:YAG CW-mode-locked laser are reduced from 20.6 ps to less than 0.30 ps rms by an electronic phase-lock loop. Stabilizer design considerations include the laser phase control characteristics, phase detector additive noise, and spurious detection of the laser amplitude noise by the loop phase detector. Applications include synchronization of multiple picosecond pulsed lasers, and synchronization of lasers and electronic signal sources in picosecond physical measurements. >
Nonlinear waves in a self-gravitating charge-varying collisional dust molecular cloud in presence of diverse equilibrium inhomogeneities

An evolutionary model for investigating the nonlinear gravito-electrostatic waves in a self-gravitating inhomogeneous planar collisional dust molecular cloud on the Jeans scales of space and time is theoretically proposed. It includes dust-charge variation and weak but finite inertia of the thermal electrons and ions. All the equilibrium gradients and inhomogeneities arising from the dynamics of the electrons, ions, neutral and charged grains are considered simultaneously for the first time. So, any conventional homogenization assumption for mathematical simplification is avoided. By standard inhomogeneous multiple scaling techniques, it is methodologically shown that the fluctuations are collectively governed by a new gravito-electrostatically coupled pair of driven Korteweg–de Vries (d-KdV) equations with new gradient-driven variable coefficients and self-consistent linear sources. A numerical analysis portrays the eigenmode excitations as oscillatory shock- and soliton-like structures. In addition, depending on the explicit regions of the varied plasma parameter space and inhomogeneities, a new shape-transition from soliton to shock and vice versa occurs. Our nonlinear wave analyses could be applied to explain multispace satellite observations and predictions made by others in the past.
Tests for an Epidemic Change in a Sequence of Exponentially Distributed Random Variables

Consider a sequence of independent exponential random variables that is susceptible to a change in the means. We would like to test whether the means have been subjected to an epidemic change after an unknown point, for an unknown duration in the sequence. The likelihood ratio statistic and a likelihood ratio type statistic are derived. The distribution theories and related properties of the test statistics are discussed. Percentage points and powers of the tests are tabulated for selected values of the parameters. The powers of these two tests are then compared to the two statistics proposed by Aly and Bouzar. The tests are applied to find epidemic changes in the set of Stanford heart transplant data and air traffic arrival data.
Rothamsted Repository Download

In water-scarce regions, alternate-furrow irrigation (AFI) — alternately wetting half of the plant roots — has proven to be an effective water-saving approach without compromising yield. However, the extent to which AFI with wastewater affects N cycling genes remains poorly studied. We aimed to investigate changes in main N transformation processes, bacterial and fungal community composition, as well as relative abundance of N cycle-associated genes in soil receiving AFI with swine wastewater. The experimental plan included three irrigation rates, irrigating pepper plants with 50%, 65%, and 80% of the amount of water required under conventional furrow irrigation to prevent the crop suffering water stress. Each treatment had a groundwater irrigation control. We measured edaphic factors, microbial community composition, and relative abundance of genes in rhizosphere and bulk soils. Altering water use in AFI did not exert a significant effect on bacterial and fungal communities. By increasing the irrigation rate of wastewater, relative abundances of nifH , bacterial and archaeal amoA and nosZ genes decreased, whereas those of nirK and nirS genes increased in the rhizosphere soil; nitrification rate did not decrease and the denitrification rate remained unchanged in both rhizosphere and bulk soil, implying that appropriate increase of wastewater use by AFI can improve N use efficiency.
Characteristics of the mouth shape in the production of Japanese

The mouth of a speaker was illuminated by a stroboscopic light source every 10ms, and pictures of both frontal and lateral views of the mouth were taken utilizing a special camera in which a long film was driven continuously. Changes in the dimensions of various parts of the mouth were measured in these pictures. The up-and-down movements of the centers of the upper and lower lips, and the lateral movements of the corners of the lips, were also recorded by attaching small metal pellets to the lips at these points and by illuminating them with the stroboscopic light source every 5ms. The frontal projections of the traces of these points were displayed three-dimensionally by adding the time axis. (This graph is called a “labiogram.”) The material used here comprised the 100 Japanese monosyllables and some words consisted of two, three or four moras. They were spoken by a female adult. On the basis of the stroboscopic observations, characteristics of the mouth shape for each kind of the speech sound and coarticulation effects were analyzed. The use of the visual information of the mouth shape to improve lipreading ability of Japanese was also discussed.
Optical polarization models of quasi-stellar objects and BL Lacertae objects

A model for optically thin synchrotron radiation from a region of partially aligned magnetic field is compared with optical linear polarization data for QSOs and BL Lacertae objects. The synchrotron theory is treated by considering the magnitude and angle of the field perpendicular to the line of sight to be described by a probability distribution. A quite general argument shows that on such a model the linear polarization should depend much more steeply on the spectral index of the radiation than it does in the case of a perfectly aligned field. For two general classes of field asymmetry, the polarization usually depends linearly or quadratically on the spectral index and on the square of the field alignment, for small values of the alignment. QSO data from the literature together with new observations of BL Lacertae objects are gathered together and compared with this model; a 15--20 percent upper limit for the field alignment is consistent with the polarization of the nonvariable objects and the quiescent polarization of the variables, while the highly polarized bursts of the variables require less than a factor of 2 enhancement in the alignment. For objects with curved spectra, perhaps due to upper energy cutoffs inmore » the electron spectrum, the theory predicts a polarization which rises gradually with frequency. This polarization wavelength dependence is weak over the optical band, but should be easily observable in those BL Lacertae objects with curved spectra, once polarization observations have been extended beyond the optical window. A possible observation of this effect in PKS 0735+17 in the optical on three nights is presented. (AIP)« less
A self‐consistent approach for micro–macro modeling of elastic–plastic deformation in polycrystalline geomaterials

This paper is devoted to multi‐scale modeling of elastic–plastic deformation of a class of geomaterials with a polycrystalline microstructure. We have extended and improved the simplified polycrystalline model presented in [Zeng T. et al., 2014. Mech. Mater.69(1):132–145]. A rigorous and fully consistent self‐consistent (SC) scheme is proposed to describe the interaction among plastic mineral grains. We have also deeply discussed the numerical issues related to the numerical implementation of the proposed micromechanical model. The efficiency of the proposed model and the related numerical procedure is evaluated in several representative cases. We have compared the numerical results respectively obtained from the fully SC model and two simplified ones. It is found that the SC model produces a softer stress–strain response than that of the simplified models. The comparisons between the estimation of overall behavior of a granite in different loading conditions and experimental data are also conducted. Copyright © 2015 John Wiley & Sons, Ltd.
On stable hydrostatic equilibrium configurations of the galaxy and implications for its halo

Using a variety of observations, it is shown that the gaseous, magnetic field, and cosmic-ray components in the local region of the Galaxy may be in a large-scale hydrostatic equilibrium that is stable against Parker-type instabilities. Lower limits for the density of the halo are derived as a function of its scale height. The temperature of the hot medium in the disk and at large distances from the plane is found to be typically about a million K in a stable equilibrium, whereas around z roughly 1-3 kpc the temperature could be only 200,000-300,000 K. The scale height of the sum of cosmic-ray and magnetic field pressures in a stable hydrostatic equilibrium state is found to be only weakly dependent on the scale height of the gaseous halo. 109 references.
Intraoperative laser speckle contrast imaging for monitoring cerebral blood flow: results from a 10-patient pilot study

Monitoring cerebral blood flow (CBF) during neurosurgery can provide important physiological information for a variety of surgical procedures. Although multiple intraoperative vascular monitoring technologies are currently available, a quantitative method that allows for continuous monitoring is still needed. Laser speckle contrast imaging (LSCI) is an optical imaging method with high spatial and temporal resolution that has been widely used to image CBF in animal models in vivo. In this pilot clinical study, we adapted a Zeiss OPMI Pentero neurosurgical microscope to obtain LSCI images by attaching a camera and a laser diode. This LSCI adapted instrument has been used to acquire full field flow images from 10 patients during tumor resection procedures. The patient's ECG was recorded during acquisition and image registration was performed in post-processing to account for pulsatile motion artifacts. Digital photographs confirmed alignment of vasculature and flow images in four cases, and a relative change in blood flow was observed in two patients after bipolar cautery. The LSCI adapted instrument has the capability to produce real-time, full field CBF image maps with excellent spatial resolution and minimal intervention to the surgical procedure. Results from this study demonstrate the feasibility of using LSCI to monitor blood flow during neurosurgery.
V-Mail: 3D-Enabled Correspondence About Spatial Data on (Almost) All Your Devices

We present V-Mail, a framework of cross-platform applications, interactive techniques, and communication protocols for improved multi-person correspondence about spatial 3D datasets. Inspired by the daily use of e-mail, V-Mail seeks to enable a similar style of rapid, multi-person communication accessible on any device; however, it aims to do this in the new context of spatial 3D communication, where limited access to 3D graphics hardware typically prevents such communication. The approach integrates visual data storytelling with data exploration, spatial annotations, and animated transitions. V-Mail “data stories” are exported in a standard video file format to establish a common baseline level of access on (almost) any device. The V-Mail framework also includes a series of complementary client applications and plugins that enable different degrees of story co-authoring and data exploration, adjusted automatically to match the capabilities of various devices. A lightweight, phone-based V-Mail app makes it possible to annotate data by adding captions to the video. These spatial annotations are then immediately accessible to team members running high-end 3D graphics visualization systems that also include a V-Mail client, implemented as a plugin. Results and evaluation from applying V-Mail to assist communication within an interdisciplinary science team studying Antarctic ice sheets confirm the utility of the asynchronous, cross-platform collaborative framework while also highlighting some current limitations and opportunities for future work.
On Bayesian consistency

We consider a sequence of posterior distributions based on a data‐dependent prior (which we shall refer to as a pseudoposterior distribution) and establish simple conditions under which the sequence is Hellinger consistent. It is shown how investigations into these pseudo posteriors assist with the understanding of some true posterior distributions, including Pólya trees, the infinite dimensional exponential family and mixture models.
Estimating a Nonstationary Spatial Structure Using Simulated Annealing

During the past decade, a useful model for nonstationary random fields has been developed. This consists of reducing the random field of interest to isotropy via a bijective bi-continuous deformation of the index space. Then the problem consists of estimating this space deformation together with the isotropic correlation in the deformed index space. We propose to estimate both this space deformation and this isotropic correlation using a constrained continuous version of the simulated annealing for a Metropolis-Hastings dynamic. This method provides a nonparametric estimation of the deformation which has the required property to be bijective; so far, the previous nonparametric methods do not guarantee this property. We illustrate our work with two examples, one concerning a precipitation dataset. We also give one idea of how spatial prediction should proceed in the new coordinate space.
Single-layer capacitive feed for wideband probe-fed microstrip antenna elements

In this paper, it is shown how a single-layer capacitive feeding mechanism, consisting of a small rectangular probe-fed patch, which is capacitively coupled to the radiating element, can be used to obtain wideband operation for probe-fed microstrip antennas on thick substrates. The main advantages of this feeding mechanism are that all the elements reside on a single layer and that it is very easy to fine-tune the input impedance. Calculated as well as measured results for rectangular, circular and annular-ring geometries are included.
Metrology and prediction for integrating a subsystem on a vehicle: Application to a fan system attached to the front end of a car

The car industry must satisfy physical acoustic and vibratory objectives in order to comply with safety and comfort norms. Among others, efforts entering the chassis should be limited. When a host structure is excited by a vibratory system, called subsystem, it also vibrates and may radiate an acoustic field. Usually, the subsystem is first tested on a bench and the question is then to deduce the efforts entering the chassis from those entering the test bench. Globalising notions of impedance already made evident via deformable structure configurations are used presently through measurements in a technological configuration, the complexity of which does not allow modelling. The case of a fan system attached to the front end of a car is under study. Some metrological conclusions, as well as more dedicated ones concerning the fan system itself, will be given. Finally, on the calculation and prediction sides, expected properties that are not satisfied (such as symmetry in measured matrices) are seen to be of no great consequence in the present case.
Critical-exponent measurements of a two-dimensional superconductor

Voltage-current (V-I) measurements of an amorphous indium/ p indium oxide thin-film composite have yielded values for the exponent eta(T) describing the power-law decay of the order-parameter correlation function appropriate to the Kosterlitz-Thouless description of phase transitions in two-dimensional systems. A pronounced crossover in the V-I characteristics at the phase-transition temperature, T/sub c/, is obtained. Theoretical expressions both above and below T/sub c/ are verified, and a value of eta(T/sub c/) = 0.23 is measured for a film with normal-state sheet resistance of 3560 . cap omega. /D'Alembertian measured at 8 K.
A mini linac based positron source

We have installed in Sac lay a demonstration setup for an intense positron source in November 2008. It is based on a compact 6 MeV electron linac to produce positrons via pair production on a tungsten target. A relatively high current of 0.15 mA compensates the low energy, which is below the neutron activation threshold. The expected production rate is 4x10(11) fast positrons per second. A set of coils is arranged to select the fast positrons from the diffracted electron beam in order to study the possibility to use a rare gas cryogenic moderator away from the main flux of particles. A first part of the commissioning of the linac has been performed. First attempts at measuring the fast positron flux are underway. This setup is part of a project to demonstrate the feasibility of an experiment to produce the H(+) ion for a free fall measurement of neutral antihydroeen (H). Its small size and cost could be of interest for a university laboratory or industry for materials science applications. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Energy and exergy analysis of Hybrid Ground-Coupled Heat Pumps with hot water supply

The energy and exergy efficiencies of a Hybrid Ground-Coupled Heat Pump (HGCHP) system with Domestic Hot Water (DHW) supply are analysed based on experimental study. Comparisons between the HGCHP and conventional DHW systems, i.e., Air Source Heat Pump (ASHP), Electric Heater (ElcH) and Gas-Fired Boiler (GasB), are made with respect to the energy and exergy efficiencies. The results show that the HGCHP system results in the highest energy efficiency, ranging from 6.7 to 2.1. In addition, the HGCHP system possesses the highest exergy efficiency among the four kinds of DHW heating systems.
Optically induced surface gratings on azoaromatic polymer films

The surface of an azoaromatic polymer film is optically altered to produce local highly efficient diffraction gratings. The gratings obtained are stable but can be erased by heating the polymer above its glass transition temperature and no permanent damage of the film is observed. Multiple gratings can be simultaneously written and gratings can be overwritten. Atomic force microscopy was used to investigate the gratings produced on the surfaces. Possible mechanisms responsible for the surface alteration are discussed.
Analytic expressions for mode conversion in a plasma with a linear density profile

The transformation of electromagnetic waves into Langmuir oscillations (and vice versa) is explicitly examined in the vicinity where the wave frequency matches the electron plasma frequency in an inhomogeneous plasma. For an unmagnetized plasma with a linear density profile of scale length L, closed‐form, analytic expressions are derived, in terms of Airy functions, for the reflection and mode conversion coefficients of Langmuir and electromagnetic waves utilizing a source approximation that is valid when the electromagnetic field scale length is large compared to that of the electrostatic field. The technique developed to determine the energy flux coefficients and the fields is general enough to apply to a plasma with a profile other than a linear one, and should prove useful in other problems where a scale length separation is valid. The reflection coefficient for the ‘‘direct’’ problem (incident electromagnetic wave) is equal in magnitude to that of the ‘‘inverse’’ problem (incident electrostatic wave).