Miracle-dz/UniFAR-FTUs huggingface dataset:
Natural element approximations involving bubbles for treating mechanical models in incompressible media

In this paper, a new approach is proposed to address issues associated with incompressibility in the context of the meshfree natural element method (NEM). The NEM possesses attractive features such as interpolant shape functions or auto‐adaptive domain of influence, which alleviates some of the most common difficulties in meshless methods. Nevertheless, the shape functions can only reproduce linear polynomials, and in contrast to moving least squares methods, it is not easy to define interpolations with arbitrary approximation consistency. In order to treat mechanical models involving incompressible media in the framework of mixed formulations, the associated functional approximations must satisfy the well‐known inf–sup, or LBB condition. In the proposed approach, additional degrees of freedom are associated with some topological entities of the underlying Delaunay tessellation, i.e. edges, triangles and tetrahedrons. The associated shape functions are computed from the product of the NEM shape functions related to the original nodes. Different combinations can be used to construct new families of NEM approximations. As these new approximations functions are not related to any node, as they vanish at the nodes, from now on we refer these shape functions as bubbles. The shape functions can be corrected enforcing different reproducing conditions, when they are used as weights in the moving least square (MLS) framework. In this manner, the effects of the obtained higher approximation consistency can be evaluated. In this work, we restrict our attention to the 2D case, and the following constructions will be considered: (a) bubble functions associated with the Delaunay triangles, called b1‐NEM and (b) bubble functions associated with the Delaunay edges, called b2‐NEM. We prove that all these approximation schemes allow direct enforcement of essential boundary conditions. The bubble‐NEM schemes are then used to approximate the displacements in the linear elasticity mixed formulation, the pressure being approximated by the standard NEM. The numerical LBB test is passed for all the bubble‐NEM approximations, and pressure oscillations are removed in the incompressible limit. Copyright © 2005 John Wiley & Sons, Ltd.
Possible pseudogap behavior of electron-doped high-temperature superconductors

We have measured the low-energy quasiparticle excitation spectrum of the electron doped high-temperature superconductors (HTS) Nd(1.85)Ce(0.15)CuO(4-y) and Pr(1.85)Ce(0.15)CuO(4-y) as a function of temperature and applied magnetic field using tunneling spectroscopy. At zero magnetic field, for these optimum doped samples no excitation gap is observed in the tunneling spectra above the transition temperature Tc. In contrast, below Tc for applied magnetic fields well above the resistively determined upper critical field, a clear excitation gap at the Fermi level is found which is comparable to the superconducting energy gap below Tc. Possible interpretations of this observation are the existence of a normal state pseudogap in the electron doped HTS or the existence of a spatially non-uniform superconducting state.
Remarks on IIB pp-waves with Ramond-Ramond fluxes and massive two dimensional nonlinear sigma models

We continue the study of supersymmetric type IIB pp-wave solutions by Maldacena and Maoz (hep-th/0207284), who showed Ramond-Ramond five-forms can induce potential terms in the light cone string actions which are nonlinear sigma models with special holonomy target spaces. We show that nonvanishing Ramond-Ramond three-forms provide extra potential terms involving Killing vectors in the string action and identify the supersymmetry requirements. In particular, in solutions with (1,1) worldsheet supersymmetry, the Killing vectors are required to be self-dual in Spin(7).
Development of an optic-based guided wave excitation technique

In recent years, nondestructive testing (NDT) has gained popularity for structural health monitoring and damage detection applications. Among the NDT methods, guided wave based NDT techniques have attracted the attention of many researchers due to their relatively long sensing range. These guided waves can be generated in a structure and sensed by a variety of techniques. The present study proposes a new scheme for PZT excitation and sensing based on laser and optoelectronic technologies, where power as well as data can be transmitted via laser. This paper mainly focuses on the excitation aspect. An arbitrary waveform is generated using a light source and transmitted to the PZT. A photodiode connected to the PZT then converts the light into an electrical signal and excites the PZT. The technique can be configured either for wired or wireless PZT excitations. Finally, the feasibility of the proposed power transmission scheme has been experimentally demonstrated in a laboratory setup.
Interband transitions in semi-metals, semiconductors, and topological insulators: A new driving force for plasmonics and nanophotonics

Plasmonic and Mie resonances in subwavelength nanostructures provide an efficient way to manipulate light below the diffraction limit that has fostered the growth of plasmonics and nanophotonics. Plasmonic resonances have been mainly related with the excitation of free charge carriers, initially in metals, and Mie resonances have been identified in Si nanostructures. Remarkably, although much less studied, semi-metals, semiconductors and topological insulators of the p-block enable plasmonic resonances without free charge carriers and Mie resonances with enhanced properties compared with Si. In this review, we explain how interband transitions in these materials show a major role in this duality. We evaluate the plasmonic and Mie performance of nanostructures made of relevant p-block elements and compounds, especially Bi, and discuss their promising potential for applications ranging from switchable plasmonics and nanophotonics to energy conversion, especially photocatalysis.
Ghost imaging: from quantum to classical to computational

Ghost‐imaging experiments correlate the outputs from two photodetectors: a high spatial‐resolution (scanning pinhole or CCD camera) detector that measures a field which has not interacted with the object to be imaged, and a bucket (single‐pixel) detector that collects a field that has interacted with the object. We review the Gaussian‐state framework for ghost imaging setups that rely on biphoton states or pseudothermal states. The understanding derived therefrom leads to two new ghost imaging configurations, employing spatial light modulators to impose controlled spatial incoherence at the source, one of which uses only a single‐pixel detector.
A computerized approach to the New York City school bus routing problem

Transportation is an area where operations research has had a great impact on systems by improving service quality and reducing operating costs. In particular, one of the most visible applications is in routing and scheduling school buses. In this paper we investigate various issues related to the development of a computerized system to help route and schedule school buses throughout the five boroughs of New York City. The routing problem presents many challenges because of its magnitude, the vast resources involved and the intricacies one encounters when routing in a completely urban environment. We analyze various aspects of the problem including the generation of routes in the Borough of Manhattan and provide a solution requiring far fewer buses than are currently in use. The computerized system, called CATS, incorporating many of the results obtained in this research, is currently being used to route Special Education students.
Changes in Environmental Parameters and Their Impact on Forest Growth in Northern Eurasia

We performed an empirical investigation of forest growth for two types of forests in northern Eurasia (larches and spruces) in order to show that the sensitivity of trees to the variable climate and geomagnetic field can be seen even under the large-scale average. The main purpose of this research was to model a forest growth rate V for each forest type on the basis of several environmental parameters influencing the tree growth in a high degree and to find the differences and similarities of the larches and spruces’ response to changing environment. We showed that V, which is related to the annual tree-ring width, could be derived from the Normalized Difference Vegetation Index (NDVI) data. Averaged yearly by species for 1982-2006, it displayed a long-term decrease (most likely related to the global climate change) as well as short-term variations with periods of 2.2, 4 and 8 years. A composite function method was used for modeling. We selected several tree growth drivers (the temperature, precipitation, insolation and the geomagnetic field intensity) that were highly correlated with V, and a function was modeled that described the behavior of V. The correlation coefficients between the derived function and experimental time series were 0.8 for larches and 0.9 for spruces. Compared with spruces, larches demonstrated higher thermo-sensitivity. A loss of tree sensitivity to temperature changes is puzzling for dendroclimatology, as a similar process might have occurred during previous periods of sharp global climate changes (as observed currently). Sensitivity of trees to geomagnetic field changes is confirmed both at long- and short-timescales. Spruces are found to be more magnetosensitive than larches.
Initial/Boundary Value Problems for Simultaneous Evolution Equations in Three Dimensions

A novel procedure recently introduced by the senior author is adapted here for the analysis of initial/boundary value problems for pairs of linear dispersive evolution equations in three dimensions. Such simultaneous equations are shown to arise naturally out of linear representations for 2+1‐dimensional nonlinear integrable equations. The method presented emanates from the encoding of such simultaneous equations as the condition that a certain differential 1‐form is closed.
Random Fibonacci sequences

Solutions to the random Fibonacci recurrence xn + 1 = xn? xn-1 decrease (increase) exponentially, xn~exp (? n), for sufficiently small (large) ? In the limits ? 0 and ? , we expand the Lyapunov exponent ? (? ) in powers of ? and ? -1, respectively. For the classical case of ? = 1 we obtain exact non-perturbative results. In particular, an invariant measure associated with Ricatti variable rn = xn + 1/xn is shown to exhibit plateaux around all rational r.
Protonated CO2 in massive star-forming clumps

Interstellar CO2 is an important reservoir of carbon and oxygen, and one of the major constituents of the icy mantles of dust grains, but it is not observable directly in the cold gas because has no permanent dipole moment. Its protonated form, HOCO+, is believed to be a good proxy for gaseous CO2. However, it has been detected in only a few star-forming regions so far, so that its interstellar chemistry is not well understood. We present new detections of HOCO+ lines in 11 high-mass star-forming clumps. Our observations increase by more than three times the number of detections in star-forming regions so far. We have derived beam-averaged abundances relative to H2 in between 0.3 and 3.8 x 10^{-11}. We have compared these values with the abundances of H13CO+, a possible gas-phase precursor of HOCO+, and CH3OH, a product of surface chemistry. We have found a positive correlation with H13CO+, while with CH3OH there is no correlation. We suggest that the gas-phase formation route starting from HCO+ plays an important role in the formation of HOCO+, perhaps more relevant than protonation of CO2 (upon evaporation of this latter from icy dust mantles).
Optical dispersion, two-photon absorption and self-phase modulation in silicon waveguides at 1.5 μm wavelength

We measure linear optical dispersion, nonlinear refraction and two-photon absorption in a silicon waveguide at 1.54 μm wavelength. The total dispersion in the silicon waveguide was found to be −9.1 fs/(nm cm). At 1.54 μm wavelength, the two-photon absorption coefficient was found to be 0.45 cm/GW and a π phase shift from self-phase modulation was observed in optical pulses of 60 W peak-coupled power, generated from an amplified gain-switched laser diode.
Mobility estimation in microsized bismuth wire arrays

Wire-diameter dependencies were investigated using microwire sample arrays with diameters from 2 to 25 μm and polycrystalline bulk bismuth. Seebeck coefficient and resistivity were measured from 50 to 300 K. Although the temperature dependence of the Seebeck coefficients of all samples were similar to that of the bulk, the resistivity dependence of the 2-μm-diameter microwire array sample had a small positive temperature coefficient, and was quite different from the other samples. Mobility was estimated using a simple model to identify the dependences on temperature and wire diameter. The ratio of electron mobility divided by hole mobility gradually decreased with decreasing temperature for samples with wire diameters below 6 μm, and electron mobility was suppressed at low temperatures, explaining the promotion of the boundary scattering. Therefore, small positive temperature coefficients of resistivity were obtained for very small diameter microwire array samples. To compare with the temperature dependen.
Halos of rich clusters of galaxies. I. An infall model for the Coma Cluster

The large mass of a cluster of galaxies slows the Hubble expansion in a surrounding volume. The ratio of the matter density near the cluster to the average density at large distances grows as the cosmological density parameter, . cap omega. , decreases. For values of . cap omega. <0.2, the gravitational attraction of the Coma Cluster acting upon an initially homogeneous external medium is sufficient to account for a galaxy population comparable to that of the Coma Supercluster.
CP violation in semileptonic tau lepton decays

The leading order contribution to the direct $CP$ asymmetry in ${\ensuremath{\tau}}^{\ifmmode\pm\else\textpm\fi{}}\ensuremath{\rightarrow}{K}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\pi}}^{0}{\ensuremath{\nu}}_{\ensuremath{\tau}}$ decay rates is evaluated within the standard model. The weak phase required for $CP$ violation is introduced through an interesting mechanism involving second order weak interactions, which is also responsible for tiny violations of the $\ensuremath{\Delta}S=\ensuremath{\Delta}Q$ rule in ${K}_{l3}$ decays. The calculated $CP$ asymmetry turns out to be of order ${10}^{\ensuremath{-}12}$, leaving a large window for studying effects of nonstandard sources of $CP$ violation in this observable.
Electron-hole imbalance in superconductor/normal-metal mesoscopic structures

We analysed the electron-hole or, in other words, branch imbalance (BI) and the related electric potential Vimb which may arise in a mesoscopic superconductor/normal-metal (S/N) structure under non-equilibrium conditions in the presence of a supercurrent. Non-equilibrium conditions can be created in different ways: a) a quasiparticle current flowing between the N reservoirs; b) a temperature gradient between the N reservoirs and no quasiparticle current. It is shown that the voltage Vimb oscillates with the phase difference . In a cross-geometry structure the voltage Vimb arises in the vertical branch and affects the conditions for a transition to the π-state.
“Clinical Profile of Spirulina on Skin Diseases-A Study in Tertiary care Hospital, Bangladesh”

: Introduction: Spirulina stands out as a sustainable bioactive microalga with health-promoting properties, and an important active ingredient of natural cosmetics products. Spirulina is a unicellular blue-green alga rich in vitamins, minerals, pigments, proteins, polysaccharides, which indicates a high potential use in anti-aging cosmetic products as well as for skin protection. Preliminary studies showed antioxidant potential, immediate benefits on the skin microrelief and hydration and skin compatibility of formulations containing Spirulina extract. Objective of this study: To assess the clinical profile of Spirulina on Skin Diseases-A Study In Tertiary care Hospital, Bangladesh. Methods: It is a descriptive study conducted at Dermatology and Venereology OPD in 250 bedded Mohammad Ali Hospital , Bogura and Rangpur Medical College Hospital, Rangpur, Bangladesh for the period from 1st January, 2020 to 31st December 2020. Fifty (50) healthy male and female participated in the clinical efficacy study, aged between 18-65 yrs. The gel-cream formulation, supplemented, or not (vehicle - FGV) with 0.1% (w/w) of Spirulina extract (FGA) was applied twice daily on the volunteers face region. The effects were evaluated in terms of skin hydration, transepidermal water loss-TEWL, skin micro relief, sebum content and morphological and structural epidermal features before and after a 28-day-period of application of the formulations . Results: A total of 50 patients were included in the study conducted over a period of 1 year, of which 25 (50.0%) were male and 25 (50.0%) were females. 50 healthy male and female participated in the clinical efficacy study, aged between 18-65 yrs. After 28 days of application of the formulation containing Spirulina extract, a significant increase of the stratum corneum water content was observed in both groups. This effect was more pronounced on the mature skin group. The formulation containing Spirulina extract increased stratum corneum water content and reduced the TEWL in both groups. However, a significant reduction in the older group, that received the formulation with Spirulina extract, was observed when compared to the younger group and to the vehicle formulation. Only the formulation containing the active ingredient under study reduced significantly the sebum content on the volunteer’s skin. It was also noted an improvement of the skin microrelief by the reduction of the surface roughness and after the treatment the keratinocytes were more uniformly distributed and homogeneous. Conclusion: The formulation containing Spirulina extract improved skin conditions and provided long term skin benefits such as hydration, protection of the skin barrier function and oil control. Finally, Spirulina extract stands out as a unique active ingredient for effective multifunctional dermocosmetic formulations for the care of young and mature skin.
Clouds and the Earth's Radiant Energy System (CERES): Long-wave Calibration Plan and Radiometric Test Model (RTM) Calibration Results

The CERES instrument has three radiometers which operate in the short-wave (0,3 μm to 5 μm), the long-wave (8 μm to 12 μm) and total broadband (0,3 μm to >200 μm) spectral regions. The long-wave calibration plan for CERES provides for absolute radiometric calibration of the two CERES sensors operating in the long-wave portion of the spectrum. Ground calibration is carried out in the TRW Radiometric Calibration Facility (RCF), a cryogenic vacuum chamber with the capability to simulate radiometrically both cold space and Earth viewing conditions. Absolute calibration is made using a temperature-based radiometric scale created by a black-body radiance standard controlled at temperatures from 200 K to 320 K. In May 1992, the CERES radiometric test model (RTM), a developmental but functionally flight-like instrument, was calibrated at TRW in the RCF. This was the first end-to-end long-wave calibration of a CERES sensor and provided a test and initial validation of the long-wave calibration plan and procedures. The gain, offset, out-of-field response and spectral response were determined for each sensor. The end-to-end long-wave calibration plan is described and the RTM calibration and validation results are presented.
Sobre os modelos de magnitude-freqüência e de estabilidade de vertentes

The first part of this article is dedicated to the magnitude-frequency approach, which represents a new light in Process Geomorphology assessment. Its proposal remounts to Wolman and Miller’s work (1960), but gained a new force with the Ahnert’s paper (1987), which integrates in a semilogarithm function the amount of effective contribution of a variety of events considered in a processes study. This approach is indistinctly applicable in all work scales and for all kinds of events, providing more accurate predictions in time and space. The second part refers to the evolution of models for slope stability, created in Soil Mechanics and adapted to Geomorphology, from Coulomb (1776) to Fredlund (1987). Surveyed data examples in a humid tropical area are presented in the two parts to illustrate the assertions and comments.
The AC photovoltaic module

This paper describes the design, development and performance of a large-area photovoltaic module whose electrical output is AC power suitable for direct connection to the utility grid. The AC PV module, developed with support from the US DOE and NREL under the PV:BONUS Program, incorporates a dedicated, integrally mounted, high-efficiency 250 Watt DC-to-AC inverter that is fully compatible with 120 V, 60 Hz utility power. We call this concept an AC photovoltaic module or in context, simply an AC Module. Because of its ease of use and wide appeal, the AC PV module may be considered the first photovoltaic appliance. The module's output may be connected directly to a building's conventional AC distribution system without need for DC wiring, string combiners, DC ground-fault protection or additional power-conditioning equipment. The AC module has the potential to become the first photovoltaic power "building product", as it can be marketed as a complete, packaged solution for the emerging residential rooftop and commercial demand-side management markets.
Orbital and escape dynamics in barred galaxies - II. The 3D system: Exploring the role of the normally hyperbolic invariant manifolds

A three degrees of freedom (3-dof) barred galaxy model composed of a spherically symmetric nucleus, a bar, a flat disc and a spherically symmetric dark matter halo is used for investigating the dynamics of the system. We use colour-coded plots to demonstrate how the value of the semi-major axis of the bar influences the regular or chaotic dynamics of the 3-dof system. For distinguishing between ordered and chaotic motion we use the Smaller ALingment Index (SALI) method, a fast yet very accurate tool. Undoubtedly, the most important elements of the dynamics are the normally hyperbolic invariant manifolds (NHIMs) located in the vicinity of the index 1 Lagrange points $L_2$ and $L_3$. These manifolds direct the flow of stars over the saddle points, while they also trigger the formation of rings and spirals. The dynamics in the neighbourhood of the saddle points is visualized by bifurcation diagrams of the Lyapunov orbits as well as by the restriction of the Poincare map to the NHIMs. In addition, we reveal how the semi-major axis of the bar influences the structure of these manifolds which determine the final stellar structure (rings or spirals). Our numerical simulations suggest that in galaxies with weak bars the formation of $R_1$ rings or $R_1'$ pseudo-rings is favoured. In the case of galaxies with intermediate and strong bars the invariant manifolds seem to give rise to $R_1R_2$ rings and twin spiral formations, respectively. We also compare our numerical outcomes with earlier related work and with observational data.