Miracle-dz/UniFAR-FTUs huggingface dataset:
crashα: coupling continuum and line radiative transfer

The detection of lya lines from local and distant objects has always been of great importance in astrophysics. It has been extensively used as indicator of redshift, as a measurement of the star formation activity of galaxies and as a probe of their internal structure. In the last few years an increasing interest has been devoted to the search of lya emitters (LAEs) at high redshift, which are expected to be characterized by a strong lya emission, but significantly attenuated by dust absorption. Emission of lya photons from high redshift sources has also an impact on the detectability of 21~cm line from neutral hydrogen in the Intergalactic Medium (IGM). This work is focused on the study, analysis and implementation of a new radiative transfer scheme (CRLya) which, for the first time in the literature, follows simultaneously the propagation of lya and ionizing radiation self-consistently. This allows to investigate the effects of evolving ionization configurations on the propagation of lya radiation and on the shaping of the line emerging from single objects. The implementation introduces the time evolution for lya photons (a feature commonly neglected in line radiative transfer codes) and, to reduce the computational time needed to follow each scattering, adopts a statistical approach to the lya treatment by making extensive use of pre-compiled tables. I find that the emerging spectra keep memory of the ionization history which generates a given ionization configuration of the gas and, to properly account for this effect, a self-consistent joint evolution of line and ionizing continuum radiation as implemented in CRLya is necessary. As next step, I implemented new features in CRLya: a new emission system, diffuse lya photons from recombination and treatment of dust. With a new test performed on a simulated galaxy at redshift z~10, I show the ability of the code to determine the variations of the lya radiation field while the gas in which it propagates is affected by the ionizing radiation emitted by the stars within the galaxy. In this test, the lya radiation is generated by both stars and recombining ionized gas. Finally I tackle the impact of lya photon scattering on the IGM temperature. This is an important issue since lya photons could be able to heat the IGM temperature above the CMB temperature and render the 21 cm line visible in emission. In the last Chapter, I discuss the implementation of the lya heating in \CRLya and I analyze how the temperature is modified by changing the most relevant physical parameters in the simulation.
The Use of an Organic Self-Assembled Monolayer Coating to Promote Dropwise Condensation of Steam on Horizontal Tubes

Hydrophobic coatings have been created through self-assembled monolayers (SAMs) on gold, copper, and copper-nickel alloy surfaces that enhance steam condensation through dropwise condensation. The monolayer is formed by chemisorption of alkylthiols on these metal surfaces. Due to their negligible thickness (10-15 A), SAMs have negligible heat transfer resistance, and involve a minuscule amount of the organic material to pose any contamination problem to the system from erosion of the coating. The coating was applied directly to copper and 90/10 copper-nickel tubes, and to previously gold-sputtered aluminum tubes. The quality of the drops on SAMs, based on visual observation, was found to be similar for the three surfaces, with the gold surface showing a slight superiority. When compared to complete filmwise condensation, the SAM coating increased the condensation heat transfer coefficient by factors of 4 for gold-coated aluminum, and by about 5 for copper and copper-nickel tubes, under vacuum operation (10 kPa). The respective enhancements under atmospheric conditions were about 9 and 14. Comparatively, the heat transfer coefficient obtained with a bare gold surface (with no organic coating) was 2.5 times that of the filmwise condensation heat transfer coefficient under vacuum, and 3.4 at atmospheric conditions.
Viscous effects on small‐amplitude surface waves

The transient behavior of small‐amplitude standing waves on the plane surface of an infinitely deep viscous liquid is investigated. An integro‐differential equation of motion for the free surface is derived and solved exactly. The small‐time behavior of the solution agrees with that computed in the approximation of irrotational flow, and the large‐time one with the results for the discrete spectrum obtained by means of the standard normal‐mode analysis. In between these two asymptotic regimes, however, the exact solution is significantly different from either approximation, except when the effect of viscosity is very small.
A simple and continuous polycrystalline silicon thin-film transistor model for SPICE implementation

A simple current-voltage model for polycrystalline silicon thin-film transistors (polysilicon TFTs) is proposed, including the sixth-order polynomial function coefficients fitted to the effective mobility versus gate voltage data, the channel length modulation, and impact ionization effects. The model possesses continuity of current in the transfer characteristics from weak to strong inversion and in the output characteristics throughout the linear and saturation regions of operation. The model parameters are used as input parameters in AIM-SPICE circuit simulator for device modeling. The model has been applied in a number of long and short channel TFTs, and the statistical distributions of the model parameters have been derived which are useful for checking the functionality of TFTs circuits with AIM-SPICE.
Boundary-crossing probabilities for the Brownian motion and Poisson processes and techniques for computing the power of the Kolmogorov-Smirnov test

Let w(t), 0 ≦ t ≦ ∞, be a Brownian motion process, i.e., a zero-mean separable normal process with Pr{w(0) = 0} = 1, E{w(t 1)w(t 2)}= min (t 1, t 2), and let a, b denote the boundaries defined by y = a(t), y = b(t), where b(0) < 0 < a(0) and b(t) < a(t), 0 ≦ t ≦ T ≦ ∞. A basic problem in many fields such as diffusion theory, gambler's ruin, collective risk, Kolmogorov-Smirnov statistics, cumulative-sum methods, sequential analysis and optional stopping is that of calculating the probability that a sample path of w(t) crosses a or b before t = T. This paper shows how this probability may be computed for sufficiently smooth boundaries by numerical solution of integral equations for the first-passage distribution functions. The technique used is to approximate the integral equations by linear recursions whose coefficients are estimated by linearising the boundaries within subintervals. The results are extended to cover the tied-down process subject to the condition w(1) = 0. Some related results for the Poisson process and the sample distribution function are given. The procedures suggested are exemplified numerically, first by computing the probability that the tied-down Brownian motion process crosses a particular curved boundary for which the true probability is known, and secondly by computing the finite-sample and asymptotic powers of the Kolmogorov-Smirnov test against a shift in mean of the exponential distribution.
Imaging characteristics of binary and phase shift masks for EUV projection lithography

Projection lithography at wavelengths in the extreme ultraviolet spectral range between 5 and 20 nm (EUV-lithography) employs reflective optical components including masks. This article applies rigorous electromagnetic field (EMF) simulation in combination with accurate projection image modeling to explore the impact of typical mask geometry parameters on the characteristics of lithographic processes. This includes telecentricity and shadowing effects resulting from the off-axis illumination in EUV systems and mask induced aberration{like effects. The importance of these effects for several alternative mask concepts including attenuated and alternating phase shift masks is investigated.
Localization and nonlinear transport in single walled carbon nanotube fibers

Electrical and magnetotransport properties of single walled carbon nanotube (SWCNT) fibers are reported. The dependencies of resistance on temperature can be approximated by the Mott law for three-dimensional variable range hopping (VRH) below 80 K and by typical law for fluctuation induced tunneling model within the range of 80–300 K. Both negative and positive magnetoresistances (MRs) were observed. At low fields, MR is negative. Positive upturn was observed on the MR curves, which shifted to the high field’s values with temperature increase. The upturn field of the MR effect was shifted from 1.5 T at 2 K to a value of about 20 T at 40 K. The value of positive MR varies as exp(B2), which changes to B1/3 at sufficiently high fields as expected for the VRH transport. The model of VRH transport is illustrated by the influence of strong microwave field and terahertz radiation induced photocurrent manifestation at low temperatures.
Transport through metallic nanogaps in an in-plane three-terminal geometry

Fabrication of three-terminal nanoscale devices is a key issue in molecular electronics to implement field-effect molecular transistor. We present in this paper two different electromigration procedures to realize metallic nanogaps at room and liquid helium temperature. A room temperature controlled electromigration process, consisting of a gradual thinning of a nanowire until the formation of a one channel contact, gives the best yield of bare nanogaps, i.e., gaps with a tunneling-like behavior. At low temperature and for a not fully controlled electromigration process, metallic clusters may remain inside the nanogap. An in-plane side gate electrode coupled to the nanogap allows transport measurements as a function of the gate voltage. Using this external tool we investigate the properties of the nanogaps, showing how clusters can mimic molecular behavior.
Maximum non-Gaussianity parameters estimation of ultrasonic echoes and its application in ultrasonic non-destructive evaluation

The accurate estimation of the ultrasonic echo pattern is essential in ultrasonic non-destructive evaluation. In this paper, a generalized parametric ultrasonic echo mode was presented. It is influenced by a set of parameters: bandwidth, arrival time, center frequency, amplitude and phase. The maximum non-Gaussianity and amplitude (MNA) principle is used to estimate these parameters. Analytically, the MNA algorithm can estimate the echo parameters accurately. Furthermore, an optimal parameter matched filter is designed with the estimated parameters to eliminate the initial phase of the ultrasonic echo. As a result, only the correlated portion remained; then, the time of arrival (TOA) and/or time of flight (TOF) of each echo can be estimated directly from the radio frequency representation of the processed ultrasonic signals. Numerical simulation and experimental results show that the optimal parameter matched filter is effective in noise suppression with improved detection signals and greater position estimation accuracy.
Numerical Analysis of the Hydrodynamic Ram Phenomenon in Aircraft Fuel Tanks

Hydrodynamic Ram (HRAM) is a phenomenon that occurs when a high-energetic object penetrates a fluid-filled container. The projectile transfers its momentum and kinetic energy through the fluid to the surrounding structure increasing the risk of catastrophic failure and an excessive structural damage on adjacent components. It is of particular concern in the design of wing fuel tanks for aircraft because it has been identified as one of the important factors in aircraft vulnerability. In order to study the aforementioned phenomenon, water filled aluminium tubes (to different volume percentages) were subjected to impact of spherical projectiles. This work is focused on the analysis of energies, momenta and pressure contours obtained by means of a previously developed and validated numerical model in order to achieve a better understanding of the fluid/structure interaction problem that takes place during the HRAM phenomenon.
Synchronization of an axial-type Bi-2223 bulk motor operated in liquid nitrogen

We fabricated and tested an axial-type Bi-2223 bulk motor that was operated in liquid nitrogen. The rotating characteristics were tested as a function of temperature, which was controlled by evacuating the metal cryostat with a rotary vacuum pump. The tests were performed for different air-gap lengths. It was found for the first time that the synchronization was realized when the operating temperature as well as the armature current was set to the appropriate range. Furthermore, the no-load test results showed that the rotating speed had no hysteretic characteristics through the increasing and decreasing process of the armature current even after the motor was pulled-in, and this result indicated that there were no trapped fluxoids in the bulk rotor.
Orthogonal Vertical Normal Modes for a Multilevel Model

Abstract Orthogonal vertical normal modes are found for a multilevel sigma-coordinate model, linearized about a state of rest with a nonisothermal mean temperature profile. Orthogonality permits the partitioning of energy into the vertical modes, and simplifies the application of variational techniques to normal mode initialization in the multilevel case. Improved procedures are described for the vertical transforms required during normal mode initialization. We derive relationships between the time derivatives of the energy computed in vertical normal mode space and in gold point space, and analogous relationships between the changes made by initialization to the vertical normal mode coefficients and the corresponding changes made in grid point space.
Prediction of a Three-Dimensional Circular Turbulent Jet in Crossflow

A quasi-three-di mensional integral method is used to solve the problem of the isothermal incompressible turbulent jet. The jet is submerged and is circular at its origin. The mathematical model is based on two integral momentum equations, one written for a direction parallel to the jet centerline and the other for a direction perpendicular to the centerline. For their solution, the entrainment rate into the jet is determined as the linear combination of a modified straight jet entrainment and the entrainment into a vortex pair. The family of velocity profiles required for the integration of the momentum equations is three-dimensional. The profiles are determined along the jet centerline on the basis of the distorted jet cross sections, thus being nonsimilar. The mathematical model is numerically solved, yielding the internal jet flowfield. Results are compared to experiments with different injection velocity to crossflow velocity ratios and with different injection angles. Agreement between theory and experiment is found to be satisfactory in some cases and good in others.
A TWO-CHANNEL PHOTOMETER WITH REFLECTIVE APERTURES

The Twin Photometric Telescope, St. Andrews has recently been upgraded which included the provision of new computer controlled photometers. The design of the single channel photometers is conventional except in the way in which target objects are acquired and monitored during observations. The new instruments use integrating CCD cameras to continuously observe the fields surrounding the apertures. This reflective aperture design also gives advantages in the efficiency with which sky observations can be made simultaneously with checks on the telescope pointing.
Newton-Raphson solution for gradually varied flow

A numerical solution is presented for the standard step method of'calculating the free surface profile in gradually varied flow. Based on the Manning equation for friction slope, the solution employs the Newton-Raphson approximation. No simplifying assumptions are made concerning the cross-section geometry. The solution is applied to the particular cases of trapezoidal and rectangular channels with a constant bed slope.
Nonlinear growth functions for modeling tree height–diameter relationships for Gmelina arborea (Roxb.) in south-west Nigeria

Tree height–diameter relationship can be used as an important input component in forest growth and yield models, and description of stand dynamics. Five nonlinear growth functions were fitted to tree height–diameter data of a 21-year-old Gmelina arborea plantation in Ibadan, Nigeria. The data consisted of three sets obtained in 2004, 2008 and 2011 for total tree height and diameter at breast height (DBH). According to the model statistics, the five growth functions fitted the data equally well, but resulted in different asymptote estimates. Modified exponential fit was observed to give the best fit for the three data sets based on least square error, coefficient of determination and significance. The predicted values follow the same nonlinear pattern and formed close to the line of best fit without much outlier. The result of this study revealed that the ability of DBH in determining height is not strong enough based on the model's goodness of fit and the model's ability for predictive purposes. Hence, more variables such as age, crown area and soil fertility were recommended to be incorporated in future prediction of the tree height in the study area.
(K−, π−) Reaction Cross Sections with Microscopic Cluster-Model Wave Functions for Light p-Shell Hypernuclei

The pion angular distributions and excitation spectra of the (K-,Jr-) reactions leading to ~Be, ~Li and ~Li are calculated by using the a+x+A(x=a,d,p) three-cluster model wave functions and the DWIA treatment. It is shown that several excited states including "genuinely hypemuclear" states can come into observation, if appropriate angles or kaon incident momenta are chosen. (K-,Jr-) reaction experiments have been proved to be very useful to study hypemuclear structures. Measurements of forward pions coming from the recoilless hyperon production have disclosed mainly the hyperon single particle aspect in hypemuclei.
Mode Estimation via Conditionally Linear Filtering: Application to Gyro Failure Monitoring

This work introduces a novel approximate nonlinear filtering paradigm for nonlinear non-Gaussian discrete-time systems. Hinging on the concept of conditional orthogonality of random sequences, the conditionally linear filtering approach is an extension of the classical linear filtering approach. The resulting estimator turns out to be conditionally linear with respect to the most recent measurement, given the passed observations, which is adequate for online filtering. It is shown that the classical Kalman filter and the conditionally Gaussian filter, i.e., the optimal filter for conditionally linearGaussian systems, are special cases of the conditionally linear filter.When applied to the problem of mode estimation in jump-parameter systems with full state information, it provides an approximate nonlinear mode estimator that only requires the first two moments of the process noise, whereas the optimal filter (Wonham filter) requires the complete noise distribution. In the case of noisy measurements in jump-linear systems, the conditionally linear filtering approach lends itself to a meaningful hybrid estimator. The proposed hybrid estimator is successfully applied to the problem of gyro failure monitoring onboard spacecraft using noisy attitude quaternion measurements. Extensive Monte Carlo simulations show that the conditionally linear mode estimator outperforms the linear mode estimator. For Gaussian noises the conditionally linear filter and the optimalWonham filter perform similarly. Moreover, for Weibull-type noises, the conditionally linear filter outperforms a Wonham filter that assumes Gaussian noises.
Error analysis of two methods for range-images registration

With the improvements in range image registration techniques, this paper focuses on error analysis of two registration methods being generally applied in industry metrology including the algorithm comparison, matching error, computing complexity and different application areas. One method is iterative closest points, by which beautiful matching results with little error can be achieved. However some limitations influence its application in automatic and fast metrology. The other method is based on landmarks. We also present a algorithm for registering multiple range-images with non-coding landmarks, including the landmarks' auto-identification and sub-pixel location, 3D rigid motion, point pattern matching, global iterative optimization techniques et al. The registering results by the two methods are illustrated and a thorough error analysis is performed.
Estimating the Internal Consistency Reliability of Tests Composed of Testlets Varying in Length

When a test is composed of a series of clustered items (testlets), authorities recommend that testlet scores be used in estimating internal consistency reliability. However, if the testlets vary in length or employ a variety of item formats, the scores will probably fail to satisfy the requirements of the tau equivalent model. In such a case, coefficient alpha will be negatively biased and a congeneric coefficient is preferable. The degree of bias in testlet-based alpha is considered via hypothetical examples and real test data. A simple formula for computing a testlet-based congeneric coefficient is presented.
HIV INTEGRASE PROTEIN

✵ ABSTRACT Azadirachta indica (Neem) is an evergreen tree that belongs to the Meliaceae family. It is native to the Indian subcontinent and grows worldwide. It is also known as the "village pharmacy" in India for its wide range of therapeutic and pharmacological properties. An in vitro study indicated that A. indica showed anti-HIV properties. However, the exact mechanism for the supposed anti-HIV properties remains unknown. This study aimed to construct an insilico database of the compounds present in A. indica and propose a computational analysis of these compounds against HIV integrase. We performed a thorough literature search to gather relevant information on the plant compounds, including chemical structure, location within the plant, extraction method, and percent yield of each compound found in the plant. We took a comprehensive approach to closely study the binding pockets of HIV integrase and performed molecular docking on A. indica compounds using Molecular Operating Environment. A deductive analysis of the docking energies of these compounds revealed thirty potential binders against HIV integrase proteins. We further validated these binders by comparing the ligand interactions to known inhibitors using Ligplot+, which identified the presence of numerous hydrogen bonds and hydrophobic interactions at the protein binding pocket. In conclusion, we propose an underlying binding potential for several A. indica compounds with HIV integrase, yielding a potential mechanism for the anti-HIV activity of A. indica.
A Multi-Scale Approach for Modelling Airborne Transport of Mucosalivary Fluid

COVID-19 pandemic promoted a lot of research activities in relation to mucosalivary fluid airborne transport. Indeed, infection mechanisms are the result of mucosalivary fluid droplets exchange and the knowledge in this area is still largely inadequate. One of the main challenges concerns the modelling of mucosalivary fluid complex nature. Specifically, this is a key element to predict small diameters dry nuclei formation which are highly relevant from the transmission risk point of view. For this reason, in this paper we present and discuss the development of a new multi-scale modelling technique which incorporates the Population Balance Equation into a standard particle-source-in-cell method. Thus, the effectiveness of the aforementioned technique in droplet nuclei generation modelling is showed and discussed. Also the impact of velocity boundary conditions at the mouth print is assessed as well as the effect of the correlations for mass transfer showing that their neglect causes an underestimation in distance reached by the droplets.