Miracle-dz/UniFAR-FTUs huggingface dataset:
Thermo‐mechanical response of concrete sandwich panels reinforced with glass fiber reinforced polymer bars

The thermo‐mechanical behavior of sandwich panels was experimentally investigated. The panels featured two external concrete layers reinforced with glass fiber reinforced polymer rebars (GFRP) and an internal expanded polystyrene insulation layer. These are typical for low load bearing and thermally insulated panels in façade claddings. To assess the suitability of the internal GFRP reinforcement, the heating condition was such that rebars in one concrete layer were exposed to temperatures higher than the glass transition temperature of the resins. Such extreme condition allowed verifying the retention of the mechanical behavior, in terms of deformability and load‐carrying capacity, with bending tests of unheated and heated panels. As main outcome, the elevated temperature produced significant modification of the insulation layer, considerable reduction of global stiffness and load‐carrying capacity, while GFRP bars were not apparently modified.
Hypersonic airbreathing propulsion

Hypersonic airbreathing propulsion technology is rapidly maturing to enable flight vehicles with transformational capabilities. APL has a rich history of leading-edge accomplishments in this arena. Laboratory-invented technology is being transitioned to a missile flight demonstration, and APL is contributing to a variety of hypersonic technologies and vehicle system concepts being developed by the DoD. Building from a substantial knowledge base on the operation of these emerging propulsion systems, this article discusses science and technology issues that will enable future performance improvements and expanded operational envelopes for these systems. Critical technology challenges include improving our understanding of the stressing aerothermal environment, achieving the necessary component and integrated engine performance, dealing with the engine system dynamics to achieve robust operation, developing proper scaling laws to enable transition from ground test to flight systems, and developing advanced lightweight, high-temperature materials and cooling techniques to handle the engine environment. We also briefly address the potential warfighting payoff of systems that use high-speed missiles.
General solution of a density functionally gradient piezoelectric cantilever and its applications

We have used the plane strain theory of transversely isotropic bodies to study a piezoelectric cantilever. In order to find the general solution of a density functionally gradient piezoelectric cantilever, we have used the inverse method (i.e. the Airy stress function method). We have obtained the stress and induction functions in the form of polynomials as well as the general solution of the beam. Based on this general solution, we have deduced the solutions of the cantilever under different loading conditions. Furthermore, as applications of this general solution in engineering, we have studied the tip deflection and blocking force of a piezoelectric cantilever actuator. Finally, we have addressed a method to determine the density distribution profile for a given piezoelectric material.
The domain derivative and two applications in inverse scattering theory

The author recalls the notion of the domain derivative of a functional. The existence and a characterization of the domain derivative of the far-field pattern for a scattering problem with Dirichlet boundary condition is proved. The second part uses this characterization for an efficient implementation of a Gauss-Newton method for solving the inverse obstacle scattering problem. The author deals with the sensitivity of the linearized obstacle problem.
Systems of differential equations which are competitive or cooperative: III. Competing species

For pt.II, see J. Math. Anal. , vol.16, p.423 (1985). Persistent trajectories of the n-dimensional system xi=xiNi(x1, . . ., xn), xi>or=0, are studied under the assumptions that the system is competitive and dissipative with irreducible community matrices ( delta Ni/ delta xj). The main result is that there is a canonically defined countable (generically finite) family of disjoint invariant open (n-1) cells which attract all non-convergent persistent trajectories. These cells are Lipschitz submanifolds and are transverse to positive rays. In dimension 3 this implies that an omega limit set of a persistent orbit is either an equilibrium, a cycle bounding an invariant disc, or a one-dimensional continuum having a non-trivial first Cech cohomology group and containing an equilibrium. Thus the existence of a persistent trajectory in the three-dimensional case implies the existence of a positive equilibrium. In any dimension it is shown that if the community matrices are strictly negative then there is a closed invariant (n-1) cell which attracts every persistent trajectory. This shows that a seemingly special construction by Smale (1976) of certain competitive systems is in fact close to the general case.
SUPERMASSIVE BLACK HOLE MASS ESTIMATES USING SLOAN DIGITAL SKY SURVEY QUASAR SPECTRA AT 0.7 < z < 2

We present Mg ii-based black hole (BH) mass estimates for 27,602 quasars with rest-frame UV spectra available in the Sloan Digital Sky Survey Data Release Three. This estimation is possible due to the existence of an empirical correlation between the radius of the broad-line region (BLR) and the continuum luminosity at 3000 Å. We regenerate this correlation by applying our measurement method to UV spectra of low-redshift quasars in the Hubble Space Telescope/International Ultraviolet Explorer databases which have corresponding reverberation mapping estimates of the Hβ BLR's radius. Our mass estimation method uses the line dispersion rather than the full width at half-maximum of the low-ionization Mg ii emission line. We measure Mg ii line dispersions for quasars whose spectra have been reconstructed using the most significant eigenspectra produced through Principal Component Analysis. We have tested the reliability of using reconstructed spectra in BH mass estimation using a Monte Carlo simulation and by comparing the results from original and reconstructed Data Release Three spectra. We show that using reconstructed spectra not only makes bias-free mass estimation possible for quasars with low spectroscopic signal-to-noise ratio, but also reduces the intrinsic scatter of the distribution of the BH masses to lower than 0.15 dex.
The Use of ICT in the learning process among the students of History and Civilization at Abdelmalek Essaadi University, Morocco

This article aims at analyzing the use of information and communications technology (ICT) in the learning process among university students of History and Civilization at Abdelmalek Essaadi University in Morocco. Data was collected by means of a questionnaire that was distributed among 187 students. The results reveal that there is still a digital divide regarding unequal access to ICT and its limited use by the students. Hence the need for multiplying efforts to ensure an effective integration strategy of ICT in the pedagogical practices.
Development of a Simple Fatigue Cracking Test for Asphalt Binders

Current Superpave® PG specification uses parameter |G*|sin(δ) to quantify asphalt binder fatigue resistance. The parameter’s effectiveness has been debated for a long time. AASHTO recently adopted the linear amplitude sweep test as a provisional standard, AASHTO TP 101-12. The authors evaluated the sensitivity of this standard to different aging conditions: unaged original binders, rolling thin-film oven-aged binders, and 20- to 80-h pressure aging vessel–aged binders. Test results showed, in many cases, longer predicted fatigue lives for more-aged binders. Thus this study developed a simple fatigue cracking test for asphalt binders. In this new test, the pure linear amplitude sweep (PLAS) test, peak shear strain was increased linearly from 0% to 30% over a course of 3,000 oscillatory cycles. A new fatigue parameter, the fatigue resistance energy index (FREI), was derived with fracture mechanics. The PLAS test and FREI parameter were sensitive to both binder aging conditions and rejuvenator type and dosage. Four laboratory mixtures were employed to evaluate the correlation between this new binder fatigue test and the two mixture cracking tests: the Texas overlay test and the Illinois flexibility index test. The results showed that the PLAS and FREI correlated well with the mixture cracking tests. Additionally, the proposed method was preliminarily verified with the FHWA accelerated loading facility test, and a fair relationship with the full-scale fatigue test data was observed. It is obvious that the PLAS and associated FREI need further validation through more field test sections.
Wave propagation in transversely isotropic elastic media - I. Homogeneous plane waves

In relation to transversely isotropic media, this paper presents a detailed study of those aspects of the propagation of homogeneous plane elastic waves which are essential to a basic understanding of the behaviour of surface waves. It is first shown how the ordering of the speeds of plane waves provides, directly and simply, a means of classifying the chosen materials, with the class label specifying the broad structure of the slowness surface and the location of its singular points. An examination of the shape of the outer sheet of the slowness surface follows, providing inter alia a complete account of the incidence of the various types of transonic states. The discussion turns next to exceptional waves, that is homogeneous plane waves which leave free of traction some family of parallel planes. The subset of the plane waves possessing this property is determined, after which the subset of the exceptional waves serving as limiting waves for an exceptional transonic state is picked out. Exceptional transonic states occur only when the axis of material symmetry lies either in the reference plane or at right angles to the reference vector and these orientations of the axis are referred to as α and β configurations respectively. The exceptional states are arranged in a threefold classification, one class consisting of a continuous set of α configurations and the others discrete β configurations. The paper ends with calculations of the limiting speed of the transonic state for the totality of α and β configurations.
The ergodicity bias in the observed galaxy distribution

The spatial distribution of galaxies we observed is subject to the given condition that we, human beings are sitting right in a galaxy — the Milky Way. Thus the ergodicity assumption is questionable in interpretation of the observed galaxy distribution. The resultant difference between observed statistics (volume average) and the true cosmic value (ensemble average) is termed as the ergodicity bias. We perform explicit numerical investigation of the effect for a set of galaxy survey depths and near-end distance cuts. It is found that the ergodicity bias in observed two- and three-point correlation functions in most cases is insignificant for modern analysis of samples from galaxy surveys and thus close a loophole in precision cosmology. However, it may become non-negligible in certain circumstances, such as those applications involving three-point correlation function at large scales of local galaxy samples. Thus one is reminded to take extra care in galaxy sample construction and interpretation of the statistics of the sample, especially when the characteristic redshift is low.
Seismic Capacity Evaluation of Interior Shear Keys for Highway Bridges

ABSTRACT Interior shear keys commonly serve as structural fuses to control damage in substructures under seismic loads. To evaluate the seismic capacity of interior shear keys, six specimens with the main variables were tested. Three failure modes of the interior shear key specimens were observed during the tests. Moreover, different analytical models corresponding to the three failure modes and an empirical formula were developed to estimate the seismic capacity of the specimens. Compared with the experimental results, the improved methods provided a more accurate prediction of the load-carrying capacity than the classical analytical models.
Study of new modulation data-transmission formats for dispersion-controlled high-bit-rate fibreoptic communication lines

The results of simulation of the propagation of optical signals in a multichannel high-bit-rate fibreoptic communication line with a combined scheme for amplifying optical signals based on new modulation data-transmission formats are presented. A comparative characteristic of formats with the amplitude and phase modulations of the electromagnetic-wave carrier is presented. The results of numerical simulation show that phase-modulation formats have a considerable advantage over amplitude formats. The use of phase-modulation formats leads to an increase in the maximum range of high-quality communications by a factor of three on average compared to amplitude-modulation formats. It is shown that optimal propagation regimes both in the case of amplitude-modulation and phase-modulation formats are realised for the normal (negative) group-velocity dispersion. However, the dispersion value for amplitude-modulation formats proves to be considerably greater than for phase-modulation formats.
NLRX1 promotes immediate IRF1-directed antiviral responses by limiting dsRNA-activated translational inhibition mediated by PKR

NLRX1 is unique among the nucleotide-binding-domain and leucine-rich-repeat (NLR) proteins in its mitochondrial localization and ability to negatively regulate antiviral innate immunity dependent on the adaptors MAVS and STING. However, some studies have suggested a positive regulatory role for NLRX1 in inducing antiviral responses. We found that NLRX1 exerted opposing regulatory effects on viral activation of the transcription factors IRF1 and IRF3, which might potentially explain such contradictory results. Whereas NLRX1 suppressed MAVS-mediated activation of IRF3, it conversely facilitated virus-induced increases in IRF1 expression and thereby enhanced control of viral infection. NLRX1 had a minimal effect on the transcription of IRF1 mediated by the transcription factor NF- (cid:75) B and regulated the abundance of IRF1 post-transcriptionally by preventing translational shutdown mediated by the double-stranded RNA (dsRNA)-activated kinase PKR and thereby allowed virus-induced increases in the abundance of IRF1 protein.
Two - temperature problem for Klein - Gordon equation

Disclosed is a monostable multivibrator in which an output voltage of an integrating circuit and a reference voltage from a reference voltage source are compared by means of a comparator, and a flip-flop is set in response to a comparison voltage of the comparator and reset in response to an external reset signal. The output of the flip-flop operates a transistor for controlling the discharge of a capacitor of the integrating circuit, and is taken out as an output pulse of the monostable multivibrator.
Ultrabright multikilovolt coherent tunable x-ray source at λ ∼ 2.71–2.93 Å

Detailed molecular structural information of the living state is of enormous significance to the medical and biological communities. Since hydrated biologically active structures are small delicate complex three-dimensional (3D) entities, it is essential to have molecular scale spatial resolution, high contrast, distortionless, direct 3D modalities of visualization of naturally functioning specimens in order to faithfully reveal their full molecular architectures. An x-ray holographic microscope equipped with an x-ray laser as the illuminator would be uniquely capable of providing these images. A quantitative interlocking concordance of physical evidence, that includes (a) the observation of strong enhancement of selected spectral components of several Xeq+ hollow-atom transition arrays (q = 31, 32, 34, 35, 36, 37) radiated axially from confined plasma channels, (b) the measurement of line narrowing that is spectrally correlated with the amplified transitions, (c) evidence for spectral hole-burning in the spontaneous emission, a manifestation of saturated amplification, that corresponds spectrally with the amplified lines, and (d) the detection of an intense narrow (δθx ∼ 0.2 mrad) directed beam of radiation, (1) experimentally demonstrates in the λ ∼ = 2.71–2.93 Å range (ℏωx ∼ = 4230–4570 eV) the operation of a new concept capable of producing the ideal conditions for amplification of multikilovolt x-rays and (2) proves the feasibility of a compact x-ray illuminator that can cost-effectively achieve the mission of biological x-ray microholography. The measurements also (α) establish the property of tunability in the quantum energy over a substantial fraction of the spectral region exhibiting amplification (Δℏωx ∼ 345 eV) and (β) demonstrate the coherence of the x-ray output through the observation of a canonical spatial mode pattern. An analysis of the physical scaling revealed by these results indicates that the capability of the x-ray source potentially includes single-molecule microimaging, the key for the in situ structural analysis of membrane proteins, a cardinal class of drug targets. An estimate of the peak brightness achieved in these initial experiments gives a value of ∼1031–1032 photons s−1 mm−2 mrad−2/(0.1% bandwidth), a magnitude that is ∼107–108-fold higher than presently available synchrotron technology.
Integrability properties of high energy dynamics in the multi-color QCD

It is shown that the interaction of reggeized gluons in the leading logarithmic approximation (LLA) of the multicolor QCD has a number of remarkable mathematical properties, including its conformal invariance, holomorphic factorization, and duality symmetry. The Reggeon Hamiltonian coincides with the Hamiltonian of the integrable Heisenberg model with the spins being the Möbius group generators. Using the Baxter–Sklyanin representation, we calculate intercepts of the colorless states constructed from three and four reggeized gluons and anomalous dimensions of the corresponding higher twist operators. To understand the origin of the integrability of high-energy dynamics in the multicolor QCD in the LLA, we investigate next-to-leading corrections to the BFKL and DGLAP equations in the N = 4 supersymmetric gauge theory beyond the LLA.
Neutrino oscillations in magnetically driven supernova explosions

We investigate neutrino oscillations from core-collapse supernovae that produce magnetohydrodynamic (MHD) explosions. By calculating numerically the flavor conversion of neutrinos in the highly non-spherical envelope, we study how the explosion anisotropy has impacts on the emergent neutrino spectra through the Mikheyev-Smirnov-Wolfenstein effect. In the case of the inverted mass hierarchy with a relatively large θ13 (sin2 2θ13 ≳ 10−3), we show that survival probabilities of ν̄e and νe seen from the rotational axis of the MHD supernovae (i.e., polar direction), can be significantly different from those along the equatorial direction. The event numbers of ν̄e observed from the polar direction are predicted to show steepest decrease, reflecting the passage of the magneto-driven shock to the so-called high-resonance regions. Furthermore we point out that such a shock effect, depending on the original neutrino spectra, appears also for the low-resonance regions, which could lead to a noticeable decrease in the νe signals. This reflects a unique nature of the magnetic explosion featuring a very early shock-arrival to the resonance regions, which is in sharp contrast to the neutrino-driven delayed supernova models. Our results suggest that the two features in the ν̄e and νe signals, if visible to the Super-Kamiokande for a Galactic supernova, could mark an observational signature of the magnetically driven explosions, presumably linked to the formation of magnetars and/or long-duration gamma-ray bursts.
Collision Analysis at 60-GHz mmWave Mesh Networks: The Case With Blockage and Shadowing

Collision Analysis at 60-GHz mmWave Mesh Networks: The Case With Blockage and Shadowing Kangjia Lyu This thesis can be viewed as two parts. The first part focuses on performance analysis of millimeter wave (mmWave) communications. We investigate how the interference behaves in the outdoor mesh network operating at 60-GHz when blockage and shadowing are present using the probability of collision as a metric, under both the protocol model and the physical model. In contrast with results reported in mmWave mesh networks at 60-GHz that advocates that interference has only a marginal effect, our results show that for a short-range link of 100 m, the collision probability gets considerably larger (beyond 0.1) at the signal-to-interference-plusnoise ratio (SINR) of interest (for example, the reference value is chosen as 15 dB for uncoded quadrature phase shift keying (QPSK)). Compensation or compromise should be made in order to maintain a low probability of collision, either by reducing transmitter node density which is to the detriment of the network connectivity, or by switching to a compact linear antenna array with more flat-top elements, which places more stringent requirements in device integration techniques. The second part of this thesis focuses on finding the optimal unmanned aerial vehicle (UAV) deployment in the sense that it can maximize over specific network connectivity. We have introduced a connectivity measure based on the commonly used network connectivity metric, which is refered to as global soft connectivity. This measure can be easily extended to account for different propagation models, such as Rayleigh fading and Nakagami fading. It can also be modified to incorporate the 5 link state probability and beam alignment errors in highly directional networks. As can be shown, under the line-of-sight (LOS) and Rayleigh fading assumptions, the optimization regarding the global soft connectivity can be expressed as a weighted sum of the square of link distances between the nodes within the network, namely the ground-to-ground links, the UAV-to-UAV links and the ground-to-UAV links. This can be shown to be a quadratically constrained quadratic program (QCQP) problem with non-convex constraints. We have also extended our global connectivity to other types of connectivity criteria: network k-section connectivity and k-connectivity. In all the three cases, we have proposed a heuristic and straightforward way of finding the suboptimal UAV locations. The simulation results have shown that all these methods can improve our network connectivity considerably, which can achieve a gain of up to 30% for a five UAV scenario.
Positron–hydrogen molecule scattering considering the positronium-formation channel

Positron–hydrogen molecule scattering has been studied using a model coupled-channel (CC) calculation considering positronium (Ps) formation for the ground state explicitly in the coupling scheme. For the first time, realistic results for the low-energy ground-state Ps-formation cross sections in e+–H2 scattering are reported employing CC, and the effect of the Ps-formation channel on the elastic cross section has also been revealed. Results are compared with previous predictions and measured data.