Miracle-dz/UniFAR-FTUs huggingface dataset:
Models for infrared emission from IRAS galaxies

Models for the infrared emission from Infrared Astronomy Satellite (IRAS) galaxies by Rowan-Robinson and Crawford, by deJong and Brink, and by Helou, are reviewed. Rowan-Robinson and Crawford model the 12 to 100 micron radiation from IRAS galaxies in terms of 3 components: a normal disk component, due to interstellar cirrus; a starburst component, modeled as hot stars in an optically thick dust cloud; and a Seyfert component, modeled as a power-law continuum immersed in an n(r) variation r sup -1 dust cloud associated with the narrow-line region of the Seyfert nucleus. The correlations between the luminosities in the different components, the blue luminosity, and the X-ray luminosity of the galaxies are consistent with the model. Spectra from 0.1 to 1000 microns are predicted and compared with available observations. The de Jong and Brink, and Helou, model IRAS non-Seyfert galaxies in terms of a cool (cirrus) component and a warm (starburst) component. The de Jong and Brink estimate the face-on internal extinction in the galaxies and find that it is higher in galaxies with more luminous starbursts. In Helou's model the spectrum of the warm component varies strongly with the luminosity in that component. The three models are briefly compared.
Transverse mode selection and injection locking in 1550-nm multimode VCSELs induced by optical injection

An experimental investigation of the modal selection induced by optical injection in 1550 nm multitransverse-mode VCSELs is performed. The free-running VCSEL emits in two transverse modes that are linearly polarized in a direction referred as parallel. We consider the situation in which parallel polarized laser light is injected in the VCSEL in order to select its fundamental transverse mode. We analyze the dependence of the modal selection process on the wavelength detuning between the externally injected signal and the fundamental mode. The injected power needed to select the fundamental mode as a function of the wavelength detuning is measured for several values of the bias current. This injected power exhibits a minimum at a positive wavelength detuning. The curves obtained for different bias currents are very close for positive and large wavelength detuning, while they are very separated for smaller detuning. The selection of the fundamental mode can be obtained with a value of the injected power that changes only slightly with the bias current when the wavelength detuning is large and positive. These results indicate that operation at large and positive wavelength detuning is of interest in the long-distance single-mode fiber transmission of multimode injection-locked VCSELs because the selection of the fundamental mode is obtained with an injected power that is almost independent on the VCSEL bias current. Both, the minimum injected power and the wavelength detuning at which it appears increase with the VCSEL bias current. We describe the relation between transverse mode selection and injection locking by comparing the dependence of both phenomena on the wavelength detuning. Modal selection is accompanied by injection locking only for large and positive values of the wavelength detuning. For small detuning values, with the VCSEL biased with a low (high) current, the injected power required for modal selection is lower (higher) than that needed for injection locking.
Stability and electronic structure of GaN nanotubes from density-functional calculations

Density-functional calculations are used to predict the stability and electronic structures of GaN nanotubes. Strain energies of GaN nanotubes are comparable to those of carbon nanotubes, suggesting the possibility for the formation of GaN nanotubes. The zigzag nanotube is a semiconductor with direct band gap, whereas the armchair nanotube has an indirect band gap. The band gaps decrease with decreasing diameter, contrary to the case of carbon nanotubes. We further discuss possible ways of synthesizing GaN nanotubes in conjunction with carbon nanotubes.
On the anticorrelation of the electric field and peak electron energy within an auroral arc

Data from the second flight of the Aries Porcupine sounding rocket campaign are presented and analyzed. The data reveal auroral electrons with spectral peaks at energies up to 4 keV and the dc electric field shows a remarkable degree of anticorrelation with the peak electron energy. Electron precipitation data are used as input to a numerical simulation of the auroral ionosphere to calculate ion production rates. From these and the recombination rates, the equilibrium electron density is calculated, properly accounting for the effective drift velocity of ionization from its point of production. Using the classical formulas, the Pedersen and Hall conductivities in the neutral frame are then calculated. Finally, various combinations of the arc motion velocity and neutral wind velocity are used to compare the resulting electric field component normal to the arc with the observations. The results imply that the ionization produced by the auroral electrons does not move with the E × B drift velocity, perhaps the result of a larger collisional coupling to neutrals than expected. A relationship is obtained between the components of the neutral wind velocity parallel and perpendicular to the arc. The observed anticorrelation is attributed to the blockage of field-aligned current and the resulting polarization of the ionosphere as well as the relatively linear relationship between peak electron energy and height integrated conductivity for peak energies below a few keV.
CdTe Schottky diodes from colloidal nanocrystals

We have fabricated ultrathin photovoltaic cadmium telluride (CdTe) film solar cells from colloidal nanorod solutions with a power conversion efficiency of 5.0% and internal quantum efficiency approaching unity near the band edge. Sintering of the CdTe nanorod films was necessary to facilitate grain growth and enhanced optical absorption. By analyzing electrode dependence, capacitance-voltage, temperature dependence, and current-voltage characteristics, the device performance is shown to be dominated by the formation of a p-CdTe/Al Schottky junction. The reduced need for material and cheaper processing make this an attractive technology for solar power generation.
A Comparison of Alternative Models for Testlets

When tests are made up of testlets, standard item response theory (IRT) models are often not appropriate due to the local dependence present among items within a common testlet. A testlet-based IRT model has recently been developed to model examinees' responses under such conditions (Bradlow, Wainer, & Wang, 1999). The Bradlow, Wainer, and Wang model introduces separate testlet factors to account for this dependence and applies a common item discrimination parameter to both the general ability and testlet factor. This study investigates several alternative ways of accounting for local dependence that make different assumptions regarding the influence of testlet factors on item performance. The authors implement several Bayesian model selection criteria to compare models using several real test data sets that have a testlet structure. Results suggest that an alternative model in which separate discrimination parameters are applied to the general ability and testlet factors provides a better fit to these data despite its greater complexity. Index terms: item response theory, Bayesian model comparison, Markov chain Monte Carlo, testlets
Electrohydrodynamic stability of dielectric liquids during transient regime of space‐charge‐limited injection

A critical examination is undertaken of experiments performed in order to verify electro‐hydrodynamic stability criterion of an insulating liquid subjected to a unipolar space‐charge‐limited injection. It appears that the comparison between predicted and measured values is meaningless because the theory is valid for a stationary state of conduction while experiments have been carried out under transient conditions. The stability of space‐charge‐limited current during the transient regime is investigated using the quasistationary approach to evaluate the growth rate and the amplification factor of the velocity perturbation. It is shown that the experimental results do not agree with theory; the measured criteria are clearly lower than the expected ones. It is suggested that this discrepancy might be attributed to phenomena related to the injection mechanisms.
Terrestrial laser scanner to detect landslide displacement fields: a new approach

A terrestrial laser scanner (TLS) allows the generation of a detailed model of a landslide surface. In this way, when two or more georeferenced models obtained by multi‐temporal scans are available, the landslide displacement field can be computed. Nevertheless, such a computation is a relatively complex task because the recognition of correspondences among the multi‐temporal models is required. The Iterative Closest Point (ICP) algorithm allows the alignment of two 3D objects having a common part by iterative shape matching. A new method for the automatic calculation of a landslide displacement field is presented here. It is based on a piecewise application of the ICP algorithm and is made possible by the robustness of this algorithm against noise and small morphological modifications. After a series of numerical experimentations, this method was successfully applied to two test sites located in the North‐Eastern Italian Alps affected by high‐risk landslides of the slump type (Perarolo di Cadore and Lamosano) with very different observational conditions.
The intensity-fluctuation distribution of Gaussian light

We discuss the quantum-mechanical problem of intensity fluctuations in samples of Gaussian light and its connection with the corresponding classical scalar problem involving fluctuations of random noise power. We obtain an expression for the intensity-fluctuation distribution of light with a Lorentzian spectrum, and investigate analytically its asymptotic behaviour. Numerical techniques are used to evaluate the distribution for various intermediate linewidths, and some examples of the corresponding theoretical photon-counting distributions are also given.
Model fitting and validation of six height–DBH equations for Pinus kesiya Royle ex Gordon in Benguet Province, Philippines

This study was conducted to develop tree height–diameter at breast height (DBH) models for Pinus kesiya Royle ex Gordon (Benguet pine) in Benguet Province, Philippines, using six commonly used nonlinear growth models. A total of 1809 total height and DBH measurements were used and randomly split into two datasets. The majority of the measurements (80%) were used for initial parameter estimation of the six models, whereas the remaining 20% were applied to validate the models. The combined data (100%) were used for the final model fitting. Mean difference (MD) for each DBH class (10 cm interval) and the overall MD were determined for model validation. Results of the validation showed that the Modified Logistic model had the best overall MD with −0.15300 m, whereas the Schnute model had the highest prediction error with −0.17000 m. The performance of the developed models was evaluated and ranked using the coefficient of determination (R2 ), root mean square error (RMSE), MD, absolute mean difference (AMD) and Furnival index (FI). Based on this evaluation, all six models were able to determine the height–DBH relationship and fitted the data well, but the Modified Logistic and Exponential growth models had the best performance evaluation results.
Phase Doppler anemometry measurements and analysis of turbulence modulation in dilute gas–solid two-phase shear flows

Flow velocities of a dilute gas–solid two-phase flow in a vertical sudden expansion were measured using phase Doppler anemometry to study the behaviour of the turbulence modulation for the stronger shear for various particle mass loadings, inlet Reynolds numbers and particle diameters. The measurements show that the particles changed the gas turbulence by elongation of the entire gas flow field in the downstream direction, which displaced the axial profile of the section-averaged fluctuation velocity in comparison with that of the single-phase flow, and by either the particle inertia reducing the local turbulence or the wake eddy effects enhancing the turbulence. Both mechanisms resulted in an apparent turbulence modulation, which has not been referred to in the related literature, and have led to an ambiguous understanding of turbulence modulation. The elongation and inlet effects should be eliminated to estimate whether the gas turbulence was really modified. The linear relationship between the gas mean velocity gradient and the root-mean-square fluctuation velocity, which was found to be similar to that in single-phase flows, gradually disappeared as the flow developed and the shear intensity reduced. The linear relationship also varied with different conditions. Specifically, the turbulence modulation was enhanced by higher particle mass loadings and the linear relationship disappeared with increasing particle mass loading. This linearity can perhaps be regarded as a criterion for determining the effect of stronger turbulence modulation.
Efficiency Comparison Between Circular and Semicircular Fins Circumscribing Circular Pipes

A new design of fin has been conceived, which is in the shape of a semicircular strip. A step-by-step straightforward detailed derivation of the governing equations for two-dimensional temperature distribution in a semicircular fin has been presented, assuming a third degree polynomial. Numerical results are presented to illustrate the effects of pipe size and the number of semicircular fins on the thermal performance of the fin. It has been shown mathematically that the efficiency of a semicircular fin can be greater than that of a circular fin, having same total volume of fin material when employed over the circumference of a circular pipe.
Rational L/sub 2/ approximation: a non-gradient algorithm

The problem of determining the best rational approximant of a given rational transfer function of higher order according to the L/sub 2/-norm criterion is considered. An efficient algorithm is presented that makes it possible to find a (local) minimum without evaluating derivatives. It is based on a reformulation of the necessary conditions for optimality in terms of interpolation constraints. Examples show that the algorithm converges rapidly to a solution even if started from poor initial guesses. <<ETX>>
Direct Nuclear Reactions

This classic volume, reprinted twenty years after it was first published, takes a close look at the theory of direct nuclear reactions. It emphasizes the microscopic aspects of these reactions and their description in terms of the changes induced in the motion of individual nucleons, except where collective motion in nuclei gives a more succinct description. Assuming only a modest knowledge of quantum mechanics and some acquaintance with angular momentum algebra, the book begins essentially at the beginning. Its goal is to provide the novice with the means of becoming competent to do research on direct reactions, and the experienced researcher with a detailed discussion of advanced topics. For completeness, appendices on angular momentum algebra and special functions are included.
Disks in Transition in the Taurus Population: Spitzer IRS Spectra of GM Aurigae and DM Tauri

We present Spitzer Infrared Spectrograph (IRS) observations of two objects of the Taurus population that show unambiguous signs of clearing in their inner disks. In one of the objects, DM Tau, the outer disk is truncated at 3 AU; this object is akin to another recently reported in Taurus, CoKu Tau/4, in that the inner disk region is free of small dust. Unlike CoKu Tau/4, however, this star is still accreting, so optically thin gas should still remain in the inner disk region. The other object, GM Aur, also accreting, has ~0.02 lunar masses of small dust in the inner disk region within ~5 AU, consistent with previous reports. However, the IRS spectrum clearly shows that the optically thick outer disk has an inner truncation at a much larger radius than previously suggested, ~24 AU. These observations provide strong evidence for the presence of gaps in protoplanetary disks.
All optical decoder switch based on photonic crystal ring resonators

Based on photonic crystal ring resonators and nonlinear Kerr effect, in this paper we proposed a 1*2 all optical decoder switch. Our proposed structure has 1 logic input port and one bias input port. This decoder switch has 2 output ports, via this logic input port we control the bias signal to transfer toward desired output port. We employed numerical methods such as plane wave expansion and finite difference time domain for analyzing the proposed structure.
Efficient methods for identifying weak nodes in electrical power networks

The paper presents two computationally efficient and simple methods of identifying weak buses in electrical power systems. The main purpose of identifying weak buses is to maintain control of voltages at these buses, in particular to prevent voltage collapse. The first method is based on the right singular vector, corresponding to a minimum singular value of the power-flow Jacobian matrix, which indicates sensitive voltages. The second method is based on the voltage collapse proximity indicator. The presented methods are successfully applied to several systems.
Structural, magnetic, and transport properties of substitutionally doped graphene nanoribbons from first principles

We present a study of the electronic properties of narrow zigzag and armchair nanoribbons substitutionally doped with a single boron, nitrogen, or phosphorus atom. Using density functional calculations, we analyze the formation energy, electronic band structures, magnetic, and quantum conductance properties of these nanoribbons with doping site positions ranging from the edge to the center of the ribbon. Substitutional doping is found to be most favorable at the ribbon edge in all the cases except for the boron-doped armchair ribbon, which has the lowest formation energy in the three-coordinated site next to the edge. Boron-doped zigzag nanoribbons exhibit spin-dependent donor-like states when the dopant is on the ribbon edge, and acceptor states as the dopant moves toward the ribbon center. Nitrogen doped zigzag nanoribbons show the opposite effect, while phosphorus doped nanoribbons exhibit both donor-like and acceptor-like states. The band structure and local density of states of these ribbons indicate that dips in conductance occur from either the presence of a localized state or the opening of mini band-gaps around a particular energy value. The variations in conductance arising from different doping profiles could be useful for tailoring the properties of graphene-based nanoelectronic devices.
Recovery Processes and Factors Limiting Cloud-Top Height following the Arrival of a Dry Intrusion Observed during TOGA COARE

Abstract This study investigates the recovery of the tropical atmosphere to moist conditions following the arrival of a dry intrusion observed during the Tropical Ocean and Global Atmosphere Program Coupled Ocean–Atmosphere Response Experiment (TOGA COARE). A cloud-resolving model was used to quantify the processes leading to the moistening of the lower and middle troposphere. The model replicates the general recovery of the tropical atmosphere. The moisture field in the lower and middle troposphere recovered in large part from clouds repeatedly penetrating into the dry air mass. The moistening of the dry air mass in the simulation was due to lateral mixing on the edges of cloudy regions rather than mixing at cloud top. While the large-scale advection of moisture played a role in controlling the general evolution of moisture field, the large-scale thermal advection and radiation tend to directly control the evolution of the temperature field. The diurnal variations in these two terms were largely responsi.
Optical properties of large-area polycrystalline chemical vapor deposited graphene by spectroscopic ellipsometry

Spectroscopic ellipsometry was used to characterize the complex refractive index of chemical vapor deposition (CVD) graphene grown on copper foils and transferred to glass substrates. Two ellipsometers, with respective wavelength ranges extending into the ultraviolet and infrared (IR), have been used to characterize the CVD graphene optical functions. The optical absorption follows the same relation to the fine structure constant previously observed in the IR region, and displays the exciton-dominated absorption peak at ∼4.5 eV. The optical functions of CVD graphene show some differences when compared to published values for exfoliated graphene.
Detached-Eddy Simulation of a Louver-Cooling Scheme for Turbine Blades

The performance of a louver-cooling scheme on a flat plate was analyzed using a detached-eddy-simulation turbulence model. It was assumed that the louver-cooling scheme was tested in a wind tunnel with the mainstream flow velocity of 20 m/s, equivalent to a Reynolds number of 16,200, based on the jet diameter. Turbulence closure was achieved by a realizable k-e-based detached-eddy-simulation turbulence model. Solutions of two blowing ratios of 0.5 and 1 were successfully obtained by running parallel on 16 nodes on a computer cluster. The flowfields were found to be highly unsteady and oscillatory in nature, with the maximum fluctuation of the adiabatic effectiveness as high as 15% of the time-averaged value. It is shown that the fluctuations in the adiabatic effectiveness are mainly caused by the spanwise fluctuation of the coolant jet and the unsteady vortical structures created by the interaction of the jet and the mainstream.
Laser beam induced currents in polycrystalline silicon thin films prepared by interference laser crystallization

Polycrystalline silicon layers are prepared by interference laser crystallization (ILC) in the superlateral growth regime. To characterize their microscopic photoelectrical properties, light beam induced current (LBIC) is used, employing a focused laser beam for local generation of photocarriers in the layers with spatial resolution of ≈0.4 μm. The results are correlated with surface morphology obtained by atomic force microscopy. In the single pulse ILC, the temperature profiles are optimized by changing the proportion of interfering beam intensities. The typical grains are of triangular shape, with a length of 1.5 μm and width <0.5 μm. The photocurrent response is dominated by variations in the sample thickness. In the multiple pulse ILC, thin films with grains of quadratic shape and of size exceeding 5 μm are obtained by shifting the sample through an interference pattern, thus taking advantage of lateral epitaxial regrowth. Here, by use of a lock–in, LBIC can detect position and local electronic prope.
Depletion characteristics of two-dimensional lateral p‐n-junctions

We have fabricated two-dimensional in-plane p‐n junctions from a p-doped pseudomorphic GaAs∕In0.1Ga0. 9As∕Al0.35Ga0. 65As heterostructure employing Si compensation doping by focused ion beam implantation. The current–voltage characteristics at room temperature showed good rectifying behavior, and the current in the reverse direction was below 1nA for voltages up to 10V. The depletion width was measured by optical beam-induced current, and a linear dependence on the reverse bias was found which is in contrast to the square root dependence observed in three-dimensional junctions. The results agree well with theoretical predictions.