Miracle-dz/UniFAR-FTUs huggingface dataset:
Size dependence of twin formation energy in cubic SiC at the nanoscale

This letter reports the size dependence of twin formation energy in cubic SiC at the nanoscale, while the bulk value is nearly zero. Atomic edges surround the twin boundary of SiC nanowires, and they are responsible for the finite twin formation energy and its size dependence. Based on classical molecular statics calculations, the average formation energy of convex and concave edges is 73meV∕nm. Effectively, the twin formation energy is inversely proportional to the length of edges surrounding the twin boundary. Results of this letter make it possible to understand large separations of twin boundaries in SiC nanowires.
Dominant region for pitch at low fundamental frequencies (F0): The effect of fundamental frequency, phase and temporal structure

When a complex tone contains many harmonics, its pitch is usually determined by harmonics in a restricted frequency region, called the “dominant region,” which for fundamental frequencies (F0s) ≥ 100 Hz corresponds to low, resolved harmonics. We estimated the dominant region for tones with low F0, by measuring thresholds, F0DLs, for detecting a change in F0 of a group of harmonics embedded within harmonics with fixed F0. The spectral position of the shifted group was systematically varied. Components were added in either cosine or random phase. For F0s of 35 and 50 Hz, the position of the dominant region depended strongly on the relative phases of the components. When the envelope had a low peak factor, with multiple peaks per period (random phase), the dominant region fell at low harmonic numbers (for F0=50 Hz), or was not well defined (for F0=35 Hz). When the envelope had a high peak factor, with one peak per period (cosine phase), the dominant region fell at high harmonic numbers, where harmonics were unresolved. Generally, performance was better for cosine than for random phase. The results indicate that harmonics in the dominant region are not always resolved.
Ionization by Electron Impact in CO, N 2 , NO, and O 2

Ionization by electron impact in diatomic gases has been studied in this work with a mass spectrometer designed to measure $\frac{m}{e}$, appearance potential, and initial kinetic energy for each ion observed. Results have been obtained for the gases CO, ${\mathrm{N}}_{2}$, NO, and ${\mathrm{O}}_{2}$ with some confirmatory work in ${\mathrm{H}}_{2}$. Discussion is included of the nature and identification of dissociative ionization processes and of the retarding potential and appearance potential measurements. Values of important quantities such as the dissociation energies of CO, ${\mathrm{N}}_{2}$, and NO; the sublimation energy of C; the electron affinity of O; and the excitation energy of ${\mathrm{O}}^{\ensuremath{-}}$ are determined again by electron impact in this work.
International Journal of Electrical and Computer Engineering (IJECE)

Rume Elizabeth Yoro, Fidelis Obukohwo Aghware, Maureen Ifeanyi Akazue, Ayei Egu Ibor, Arnold Adimabua Ojugo Department of Computer Science, Dennis Osadebey University Asaba, Asaba, Nigeria Department of Computer Science, University of Delta, Agbor, Nigeria Department of Computer Science, Delta State University, Abraka, Nigeria Department of Computer Science, University of Calabar, Calabar, Nigeria Department of Computer Science, Federal University of Petroleum Resources Effurun, Effurun, Nigeria
θ-PSO: a new strategy of particle swarm optimization

Particle swarm optimization (PSO) is an efficient, robust and simple optimization algorithm. Most studies are mainly concentrated on better understanding of the standard PSO control parameters, such as acceleration coefficients, etc. In this paper, a more simple strategy of PSO algorithm called θ-PSO is proposed. In θ-PSO, an increment of phase angle vector replaces the increment of velocity vector and the positions are decided by the mapping of phase angles. Benchmark testing of nonlinear functions is described and the results show that the performance of θ-PSO is much more effective than that of the standard PSO.
On Positive Harris Recurrence of Multiclass Queueing Networks: A Unified Approach Via Fluid Limit Models

It is now known that the usual traffic condition (the nominal load being less than one at each station) is not sufficient for stability for a multiclass open queueing network. Although there has been some progress in establishing the stability conditions for a multiclass network, there is no unified approach to this problem. In this paper, we prove that a queueing network is positive Harris recurrent if the corresponding fluid limit model eventually reaches zero and stays there regardless of the initial system configuration. As an application of the result, we prove that single class networks, multiclass feedforward networks and first-buffer-first-served preemptive resume discipline in a re-entrant line are positive Harris recurrent under the usual traffic condition. AMS 1991 subject classification: Primary 60K25, 90B22; Secondary 60K20, 90B35.
A Characterization of the Variation in Relative Humidity across West Africa during the Dry Season

AbstractThe variation of relative humidity across West Africa during the dry season is evaluated using the Modern Era Retrospective Analysis for Research and Applications (MERRA) dataset and the method of self-organizing maps. Interest in the dry season of West Africa is related to the connection between near-surface atmospheric moisture and the occurrence of meningitis across West Africa, most notably in the region known as the meningitis belt. The patterns in relative humidity are analyzed in terms of frequency of each pattern as well as the sequencing from one pattern to the next. The variations in relative humidity are characterized subannually for individual years from 1979 to 2009 as well as decadally over the entire 30-yr duration of dry seasons in West Africa. The progression from relatively moist patterns to relatively dry patterns and back to the moist patterns over the course of the dry season corresponds to the northward and then southward migration of the intertropical convergence zone. The r.
The Stable Set of Associated Primes of the Ideal of a Graph

Let G be a graph and let I be the edge ideal of G. We give a constructive method for determining primes associated to the powers of I. Brodmann showed that the sets of associated primes stabilize. for large powers of I. Our construction will yield this stable set and an upper bound on where the stable set will occur.
Analysis of lithium niobate all-optical wavelength shifters for the third spectral window

We numerically investigate the performance of wavelength shifters in quasi-phase-matched channel waveguides in lithium niobate. The shifters are based on cascaded quadratic processes, namely, sum- and difference-frequency generation, and permit efficient conversion and signal gain near 1.55 µm over the full bandwidth of erbium-doped fiber amplifiers.
Analízate: Towards a Platform to Analyze Activities and Emotional States of Informal Caregivers

An informal caregiver is exposed to an emotional overload, which can lead to high stress levels. To provide caregivers with awareness about their emotions, we propose an emotion-tracking platform based on Facebook status updates. For this purpose, we trained several classification models to assign emotions to Facebook status updates. Then, we developed a Facebook application that connected to each user’s profile, gathered their status updates, classified their emotions, and generated a summary. We tested the application with 54 participants, finding the relative precision to be 84%, while the platform was perceived to be valuable and novel. Participants thought the application allowed them to think about their emotions and the information they share.
Statistical Inference Based on Ranks

A coherent, unified set of statistical methods, based on ranks, for analyzing data resulting from various experimental designs. Uses MINITAB, a statistical computing system for the implementation of the methods. Assesses the statistical and stability properties of the methods through asymptotic efficiency and influence curves and tolerance values. Includes exercises and problems.
Mean Pulse Shape and Polarization of PSR J0437–4715

Mean pulse shape and polarization parameters have been obtained for PSR J0437-4715 at 438, 660, and 1512 MHz using the Australia Telescope National Facility Parkes 64 m radio telescope and the Caltech correlator. The pulse profile is complex with many identifiable features, including an unusual double “notch,” and evolves strongly with frequency. Strong linear and circular polarization are observed at all frequencies, with the fractional linear polarization highest near the wings of the pulse. Circular polarization is strongest near the pulse center, with a sense reversal at the center. Position-angle variations are complex and include what appear to be orthogonal-mode transitions. However, at other frequencies, some of these transitions are not orthogonal. Even when these transitions are allowed for, the position angle does not follow the simple rotating-vector model, suggesting departures from a dipole field configuration in the emission region. A frequency-dependent lag of the total-intensity profile with respect to the polarization profile is observed. This effect has not previously been seen in any pulsar. An improved value of the rotation measure along the path to the pulsar is derived.
Structure and formation of dust devil–like vortices in the atmospheric boundary layer: A high-resolution numerical study

[1] The development of dust devil–like vortices in the atmospheric convective boundary layer (CBL) is studied using large-eddy simulation (LES). Special focus is placed on the analysis of the spatial structure of the vortices, the vorticity-generating mechanisms, and how the vortices depend on the larger-scale coherent near-surface flow pattern of the CBL. Vortex centers are automatically detected during the simulation, and a tracking method is developed, which allows us to determine the temporally averaged structures of selected vortices. Also, various vorticity budget terms are calculated. A reference study with high resolution (2 m) and large model domain (2000 × 2000 × 500 grid points) is carried out to account for the dependency of vortex generation on the larger-scale CBL flow pattern, i.e., the near-surface hexagonal cells. Vortices predominantly appear within the vertices of the cells. Their vorticity is maintained by a combination of divergence and twisting effects. Flow visualizations by tracers show that the vortices have an inverted cone-like shape, similar to observed dust devils. Simulated vortex characteristics like tangential velocity or vorticity are at the lower limit of observed values. Strength and number of vortices heavily depend on the background wind. A small background wind enhances vortices, but for a mean wind speed of 4.4 m s−1, vortex generation is significantly reduced, mainly because the near-surface flow changes from a cellular to a more band-like pattern. A new mechanism is suggested, which relates the initial vortex generation to the cellular flow pattern.
Observed and projected precipitation variability in Athens over a 2.5 century period

The observed and projected precipitation variability in Athens is assessed for a 2.5 century period. The observed variability is examined using the 150‐year historical record of the National Observatory of Athens, while future variability using an ensemble of regional climate models. A good agreement between observations and the model ensemble was found for annual and seasonal precipitation. The model ensemble overestimated the number of rainy days and precipitation amount corresponding to light precipitation and underestimated them corresponding to moderate–heavy precipitation. A 35% decrease in total annual precipitation coupled with an increase in extreme precipitation was projected by the model ensemble up to 2100. Copyright © 2013 Royal Meteorological Society
Ultraviolet Observations of Prominence Activation and Cool Loop Dynamics

In this paper we investigate the thermal and dynamic properties of dynamic structures in and around a prominence channel observed on the limb on 2003 April 17. Observations were taken with the Solar and Heliospheric Observatory's Solar Ultraviolet Measurements of Emitted Radiation (SOHO SUMER) in lines formed at temperatures from 80,000 K to 1.6 MK. The instrument was pointed to a single location and took a series of 90 s exposures. Two-dimensional context was provided by the Transition Region and Coronal Explorer (TRACE) in the UV and EUV and the Kanzelhöhe Solar Observatory in Hα. Two dynamic features were studied in depth: an activated prominence and repeated motions in a loop near the prominence. We calculated three-dimensional geometries and trajectories, differential emission measures, and limits on the mass, pressure, average density, and kinetic and thermal energies. These observations provide important tests for models of dynamics in prominences and cool (~105 K) loops, which will ultimately lead to a better understanding of the mechanism(s) leading to energy and mass flow in these solar features.
Solitons as elementary particles: a paradigm scrutinized

Solitons occur as topologically stable solutions of the classical field equations underlying a large class of quantum field theories. We review some of the results which show that these solitons behave like classical Newtonian particles, albeit with some surprising behaviour, and that, suitably quantized, these solitons contribute to the particle spectrum of the quantum field theory. Along the way, we highlight some of the remaining problems. We also comment on the reverse issue: do the elementary particles we know experimentally have a description as solitons?
Weak dependence beyond mixing and asymptotics for nonparametric regression

We consider a new concept of weak dependence, introduced by Doukhan and Louhichi [Stochastic Process. Appl. 84 (1999) 313-342], which is more general than the classical frameworks of mixing or associated sequences. The new notion is broad enough to include many interesting examples such as very general Bernoulli shifts, Markovian models or time series bootstrap processes with discrete innovations. Under such a weak dependence assumption, we investigate nonparametric regression which represents one (among many) important statistical estimation problems. We justify in this more general setting the whitening by windowing principle for nonparametric regression, saying that asymptotic properties remain in first order the same as for independent samples. The proofs borrow previously used strategies, but precise arguments are developed under the new aspect of general weak dependence.
Spectroscopic characterization and energy transfer process in cobalt and cobalt-iron co-doped ZnSe/ZnS crystals

Cobalt doped II-VI wide band semiconductors (e.g. ZnSe, ZnS, CdSe) are promising media for infrared (IR) laser applications. They could be utilized as effective passive Q-switches for cavities of Alexandrite as well as Nd and Er lasers operating over 0.7-0.8, 1.3-1.6, and ~2.8 μm spectral ranges. We report spectroscopic characterization of Co:ZnSe and Co:ZnS crystals. Absorption cross-sections were measured for 4A2(F) → 4T1(P), 4A2(F) → 4T1(F), and 4A2(F) → 4T2(F) transitions with maximum absorption at 768(726), 1615(1500), 2690(2740) nm for ZnSe(ZnS) crystals, respectively. The calculated absorption cross-sections of the above transitions were estimated to be 64(56)×1019, 7.5(7.8)×1019, and 0.52(0.49)×1019 cm2 for ZnSe(ZnS) crystal hosts. In addition to the above applications the cobalt ions could be utilized for excitation of Fe2+ ions via resonance energy transfer process. Tunable room temperature lasing of Fe 2+ doped binary and ternary chalcogenides has been successfully demonstrated over 3.5-6 μm spectral range. However, II-VI lasers based on Fe2+ active ions don’t feature convenient commercially available pump sources (e.g. some Fe doped crystal hosts require pump wavelengths longer than 3 μm). Therefore, the process of energy transfer from Co2+ to Fe2+ ions could enable utilization of commercially available visible and near-infrared pump sources. We report a spectroscopic characterization of iron-cobalt co-doped ZnS and ZnSe crystals over 14-300K temperature range. Mid-IR laser oscillation at 3.9 μm(3.6 μm) via energy transfer in the Co:Fe:ZnSe (Co:Fe:ZnS) co-doped crystals was demonstrated under cobalt excitation at 4A2(F) → 4T1(P) (~0.7μm) and 4A2(F) → 4T1(F) (~1.56 μm) transitions.
A Compositing Approach for Preserving Significant Features in Atmospheric Profiles

Abstract Composite profiles of thermodynamic and kinematic variables are prepared to represent the characteristics of the environment within which a particular atmospheric phenomenon occurs. During the averaging process, it is desirable to retain the dominant features and associated gradients found in the individual profiles so that representative values of quantities such as flux parameters, energy budgets, convective available potential energy, and various stability indices can be computed from the composite profiles. The conventional compositing approach, where averages are computed at common heights, reduces or even smooths out a significant feature when the height and vertical extent of the feature differ from one individual profile to the next. To retain a desirable feature in the composite profile, it is necessary to compute averages at the heights where the feature occurs and to compute the average height of the feature itself. As an example of the capabilities of this scaling or feature-preservin.
A Finite Element Analysis of the Effects of Sub- strate Curvature on Cellular Traction Forces and Morphology

That mechanical properties of the extracellular environment can influence cell behaviour has already been established. Recent studies indicate that human mesenchymal stem cells are affected by the surface curvature of the underlying substrate. However, how meso-scale substrate curvature affects cell behaviour is still not clear. This study utilised the finite element method to simulate a prestressed human mesenchymal stem cell conforming and attaching to a flat control substrate, concave hemispherical and concave cylindrical substrates with curvature radii from 300 μm to 75 μm. The cell model comprises the actin cortex, cytoskeleton, and nucleus modelled with a hyperelastic material definition and 30 linear elastic stress fibres prestressed with a force of 10 nN. The effects of surface curvature on cellular traction forces, cell height, nuclear aspect ratio and actin cortex was studied. The vertical traction forces were observed to be 70% and 40% lower for the hemispherical and cylindrical substrates of the highest curvatures compared to the flat control substrate, respectively. Cellular traction forces towards the cell periphery were roughly 10-20% higher than the more central cellular traction forces independent of substrate curvature. Stresses in the actin cortex were observed to increase by 290% and 220% from the flat control substrate to the hemispherical and cylindrical substrates of the highest curvatures, respectively. These results indicate that the cell is more sensitive to hemispherical substrates than cylindrical substrates. The results also support in vitro observations where hMSCs are seen to span hemispherical substrates and avoid continuous contact. Master of Science Thesis A.S. Tjernshaugen
Aerodynamic Performance of VAWT Airfoils: Comparison between Wind Tunnel Testing Using a New Three-Component Strain Gauge Balance and CFD Modelling

Vertical axis wind turbines are an emerging and in-development wind energy technology which are characterized by their complicated aerodynamics. Detached flow conditions, which are typically developed at operational tip speed ratios, demand a rigorous characterization of the airfoils for an accurate prediction of the turbine performance. In this work, a custom-built, three-component external strain gauge balance, specifically developed for airfoil testing, is validated. The physical reasons responsible for discrepancies with reference data are also analyzed. Two- and three-dimensional flat plates, as well as the DU06-W-200 airfoil, are tested in a wind tunnel. Lift and drag coefficients and pitching moments are obtained for a wide angular range at Re = 200,000. The results are compared with data from the bibliography and CFD simulations, performed with the recently developed GEKO (generalized k-omega) turbulence model, achieving remarkable agreement. Instantaneous forces are also analyzed with both experimental and CFD techniques, providing interesting results of the unsteady fluid dynamics. Finally, critical factors affecting the measurements are identified and enhancements are proposed for future works. In summary, a thorough evaluation of this new balance design is provided, showing its valuable potential for VAWT applications.
Feeling One Thing and Doing Another: How Expressions of Guilt and Shame Influence Hypocrisy Judgment

The present study investigated how people, as uninvolved social observers (i.e., those not affected by the emotion expresser’s behavior), judge hypocrisy in a target who publicly expresses their self-conscious emotions (i.e., shame and guilt) after making an immoral decision, then repeats the same immoral behavior again. Results across the two studies conducted showed that participants viewed the target as more hypocritical when the target expressed guilt (vs. shame) for their past misdeed and then committed the same act again. The present study suggests that social perceivers tend to infer expressions of guilt (and of shame to a lesser degree) as signaling future changes, which is reflected in judgments of hypocrisy. The study further discusses implications for the social functions of emotional expression and communication.
Design of 1-7 GHz High Gain Wideband Filter LNA for Wireless Applications

The paper proposes a 3-stage wideband LNA based on 3rd order Chebyshev band pass filter with cascode MOS configuration and an output matching stage. MOS1 along with source degeneration inductor provides narrowband impedance matching and MOS2 in cascode provides isolation of gate-to-drain capacitance with the input section in the feedback path. The input impedance of the cascode amplifier is incorporated as part of the filter. Band pass filter provides wide bandwidth operation with flat gain over the frequency of interest. The proposed LNA circuit is implemented in 90 nm MOS PTM node. The circuit furnishes a gain of 17.95 dB with a minimum noise figure of 1.115 dB and a good reverse isolation of −22.8 dB over a frequency range of 1–7 GHz.
The Optical Spectral Line List of RR Telescopii

The symbiotic nova RR Telescopii has been observed with the 1.5 m telescope of the Cerro Tololo Inter-American Observatory (CTIO), using the 1.5 m bench-mounted echelle spectrograph in conjunction with a Tektronix CCD. It displays a rich emission-line spectrum, ranging in excitation from O I to [Ni VIII]. We present a list of 491 measured lines, with their suggested identifications, covering a wavelength range from 3430 to 9320 Å. Of these, only nine are unidentified, and 70 lines are cataloged that were not given in the original line list of Thackeray. Absolute line intensities are also given, which have been derived by comparing the high-resolution data with a flux-calibrated low-resolution spectrum taken with the Cassegrain spectrograph on the 1.0 m telescope at CTIO.