Miracle-dz/UniFAR-FTUs huggingface dataset:
Transient Groundwater Flow In A Single Fracture

Understanding the water flow behaviour in a single fracture is essential for investigating groundwater flow and solute transport in fractured crystalline rock formations in the context of water supply, remediation of dissolved contaminant or projecting long-term nuclear waste repositories. Numerical modelling was used as a tool for studying the geometrical and hydraulic properties of a single fracture. Two computer codes were developed for this purpose. The first one simulates the fracture-free space geometry and the other one solves the transient flow equation. The fracture geometry simulation consists of defining the contact zones where the fracture is closed for the water flow, and of generating the aperture values in zones of water flow. The distribution of contact areas within the simulated fracture is governed by principles of percolation theory. The positive values of aperture in water-flow zones were distributed according to the knowledge of real fracture data. Transient flow simulation is based on principles of fluid mass balance in the fracture space and on locally valid cubic law that quantifies flow rate through the fracture profile. The problem is solved numerically by means of the discretization in time and the finite element method. The percolation theory approach makes it possible to get a faithful evaluation of the fracture permeability and the transient form of the flow equation enables us to simulate the flow and pressure field propagation in accordance to laboratory or field test conditions.
Zone-boundary phonons in hexagonal and cubic GaN

We present results of second-order Raman-scattering experiments on hexagonal and cubic GaN covering the acoustic and the optical overtone spectral region. Based on a comparison of the experimental scattering data with the calculated phonon-dispersion curves as well as the group-theoretically derived selection rules, we were able to assign the observed structures to particular phonon branches and determined the points in the Brillouin zone from which the scattering originates. Our measurements reveal the energies of acoustic zone-boundary phonons in hexagonal GaN.
Analysis of streamwise-oriented vortex interactions for two wings in close proximity

This investigation addresses the impingement of the trailing vortex provided by a leader-wing upon a follower-wing operating in close proximity. Exploration of the relative spacing between the two wings reveals several distinct flow regimes occur within a small range of lateral positions of the incident vortex. These changes effectively alter the evolution of the follower-wing wake via mutual induction between the incident and trailing vortices. Several unsteady mechanisms impact the general flow field in each regime. The incident vortex for an inboard impingement rapidly decays over the wing due to transition to turbulence. A tip-aligned vortex results in a highly unsteady interaction and generates enhanced surface pressure fluctuations beneath the tip vortex. Placing the incident vortex outboard elicits mutual instability between the leader and follower-wing trailing vortices. While lift-enhancement was found to be dominated by an inviscid increase in effective angle of attack, viscous effects in the ne.
Direct imaging of gate-controlled persistent spin helix state in a modulation-doped GaAs/AlGaAs quantum well

Using time- and spatially-resolved Kerr microscopy, we directly measure the spatiotemporal evolution of photoexcited local spins of a two-dimensional electron gas in a modulation-doped GaAs/AlGaAs quantum well with a top gate electrode. The spatial pattern of spins after diffusion is controlled by a gate voltage that changes the strength of the spin–orbit interaction (SOI) field. By measuring the time dependence of spin distribution with an external magnetic field, we successfully observe a persistent spin helix state by tuning the gate voltage, and we obtain both Rashba and Dresselhauss SOI parameters separately.
Pattern formation in martensitic thin films

Pattern formation in martensitic materials refers to the accommodation problem of how to mix martensitic variants coherently to minimize the strain energy. A framework motivated by energy-minimizing multirank laminated patterns is proposed to study this problem in martensitic films. It is found that the interfaces between the variants of martensite can be quite different in thin films than in bulk materials, and they typically have a simpler structure. Various intriguing and fascinating self-accommodation patterns are predicted for martensitic thin films with different orientations. The results are in good agreement with the Bhattacharya-James thin-film theory [K. Bhattacharya and R. D. James, J. Mech. Phys. Solids 47, 531 (1999)] as well as with experimental observations.
Elektronenoptische Abbildung auf Grund der Wellenmechanik. I

Ausgehend von der Schrodinger-Gleichung des rotationssymmetrischen elektrisch-magnetischen Feldes wird die Existenz einer objektahnlichen Abbildung bewiesen. Die Wellenfunktion des paraxialen Bereiches wird dazu fur jede beliebige Einstellebene durch den Verlauf der Wellenfunktion in der Objektebene ausgedruckt. Mit Hilfe dieser Losung der paraxialen Schrodinger-Gleichung wird gezeigt, das eine bestimmte Einstellebene existiert, in welcher bis auf eine Masstabsanderung die gleiche Verteilung der Elektronenstromdichte wie in der Objektebene herrscht. Diese Bildlage und die Vergroserung stimmen mit den entsprechenden Grosen der geometrischen Elektronenoptik uberein. Die Abbildung eines Spaltes und einer Kreislochblende wird fur eine bestimmte typische Magnetlinse durchgerechnet. Allgemein zeigt sich, das in einer beliebigen Einstellebene Fresnelsche Beugungserscheinungen entstehen, deren Beugungssaume mit Annaherung an die Bildebene unbegrenzt zusammenrucken und so den scharfen Bildrand bilden. Der wesentliche Einflus einer Blende auf die Abbildung wird untersucht. Man kommt so von der Schrodinger-Gleichung in konsequenter Weise zur Theorie der wellenmechanischen Abbildung durchstrahlter periodischer Objekte (Gitter), welche das Analogon zur Abbe-Rayleighschen Theorie darstellt. Im Gegensatz zur Lichtoptik spielt die Abbildung von Phasenobjekten die beherrschende Rolle. Schlieslich wird in einem II. Teil das Problem der Modifikation der Wellenfunktion durch das elektrisch-magnetische Abbildungsfeld auch fur das nicht-paraxiale Gebiet behandelt, indem das wellenmechanische Analogon zur Kirchhoffschen Beugungsformel fur den felderfullten Raum aufgestellt wird. Auf diese Weise ergibt sich eine konsequente Theorie des wellenmechanischen Einflusses der Bildfehler auf die Abbildung.
Increasing the structural variety of discrete nondiffracting wave fields

We investigate discrete nondiffracting beams (DNBs) being the foundation of periodic and quasiperiodic intensity distributions. Besides the number of interfering plane waves, the phase relation among these waves is decisive to form a particular intensity lattice. In this manner, we systematize different classes of DNBs and present similarities as well as differences. As one prominent instance, we introduce the class of sixfold nondiffracting beams, offering four entirely different transverse intensity distributions: in detail, the hexagonal, kagome, and honeycomb pattern, as well as a hexagonal vortex beam. We further extend our considerations to quasiperiodic structures and show the changeover to Bessel beams. In addition, we introduce a highly flexible implementation of the experimental analog of DNBs, namely discrete pseudo-nondiffracting beams, and present locally resolved intensity and phase measurements, which underline the nondiffracting character of the generated wave fields.
Seasonal winter forecasts and the stratosphere

We investigate seasonal forecasts of the winter North Atlantic Oscillation (NAO) and their relationship with the stratosphere. Climatological frequencies of sudden stratospheric warming (SSW) and strong polar vortex (SPV) events are well represented and the predicted risk of events varies between 25 and 90% from winter to winter, indicating predictability beyond the deterministic range. The risk of SSW and SPV events relates to predicted NAO as expected, with NAO shifts of −6.5 and +4.8 hPa in forecast members containing SSW and SPV events. Most striking of all is that forecast skill of the surface winter NAO vanishes from these hindcasts if members containing SSW events are excluded.
On exponential asymptotics for nonseparable wave equations I: complex geometrical optics and connection

Kelley’s Geometrical Optics method opens an efficient approach to the study of waves when the variables in the wave equation cannot be separated. The trajectories of the Hamilton-Jacobi equation are then needed for access to the wave structure. When several disjoint potential wells are present, account of the interaction between them requires consideration of trajectories and tori in complex phase space and of the unfamiliar connectivity of such complex toroids. It is shown how connection theory across wells and barriers can be reformulated in a manner that is simple and flexible and assures the rigorous reliability needed for exponentially precise approximation to functionals of the Hamiltonian operator in several dimensions. To make this difficult and unfamiliar subject more accessible, its discussion is preceded by a simple example of a double well on a strip domain in two dimensions. Parts II and III will apply the results to the quantitative resolution of degeneracy of discrete and continuous spectra.
PROPERTIES AND GRAVITATIONAL COLLAPSE OF THE CORE IN G19.61 − 0.23

We present the results of an observational study toward the core in G19.61 − 0.23 with the Submillimeter Array. The continuum at 900 μm revealed that the core has a mass of 15 M☉. The rotational temperature and the column density of CH3CN are 552 K and 3.4 × 1016 cm−2, respectively. No UC H ii region or infrared source was found at the peak position of the core. Inverse P Cygni profiles were clearly exhibited in the 13CO J = 3–2 and CN N = 3–2 lines, strongly indicating that material infall is taking place in this compact hot core. The mass-infall rate estimated from the 13CO J = 3–2 line is 6.1 × 10−3 M☉ yr−1, which agrees with the value calculated from a free-fall model. The mass-infall rate, together with the difference of the infall velocities estimated from the 13CO J = 3–2 and CN J = 3–2 lines as well as the spatial distribution of their absorption show that the inflow motion originates from gravitational potential and is consistent with the inside-out model. The prior maser observations indicated outflow activities in this core. The signatures of both inflow and outflow activities suggest that there may be an embedded early high-mass star forming via gas accretion. After comparing the emissions of CO and its isotopes with the other widely used inflow motion tracers, we find that the CO lines may also be useful to trace inflow motion in a small scale when the continuum background is bright enough.
Low delay audio coding based on logarithmic spherical vector quantization

Most systems for the transmission and storage of speech and audio signals are nowadays based on digital technology. For specific applications, e.g., wireless microphones for live concerts, however, operation constraints are defined which only analog technology could fulfill. The most critical and often contradictory constraints are a low algorithmic delay, a high perceived quality for speech as well as for audio signals at low bit rates and a low computational complexity. State-of-the-art standardized approaches for digital lossy source coding in general either have a high algorithmic delay or have been optimized for speech signals only and are not suitable for audio coding. The outcome of this thesis are novel approaches for the lossy compression of digital speech and audio signals with low algorithmic delay. The new concepts are principally based on combined linear prediction and vector quantization which is wellknown from state-of-the-art speech codecs. However, fundamental modifications of the concepts known from speech coding are essential to achieve a low algorithmic delay and a low computational complexity as well as a high perceived speech and audio quality at low bit rates. The developed approaches for low delay audio coding significantly outperform standardized audio codecs with a comparable algorithmic delay and bit rate, e.g., the ITU-T G.722 audio codec, in terms of a higher subjective quality for speech and particularly audio signals.
Description of the two-neutrino ββ decay of 100Mo by pnMAVA

The microscopic anharmonic vibrator approach (MAVA) is a scheme where the one- and two-phonon states of an even–even nucleus are treated consistently by using a realistic microscopic nuclear Hamiltonian. This model has recently been extended to describe odd–odd nuclei by adding proton–neutron phonons in a scheme called the proton–neutron MAVA (pnMAVA). In this paper, we apply pnMAVA to compute the nuclear matrix elements corresponding to the two-neutrino double beta (2νββ) decay of 100Mo to the ground state and the first excited 0+ state of 100Ru in a realistic single-particle space. We also compute the GT− and GT+ Gamow–Teller strength functions and compare them with the plain pnQRPA (proton–neutron QRPA) and available data. The redistribution of strength to four-quasiparticle degrees of freedom can be clearly seen in the GT+ function. The more striking effect is seen in the 2νββ matrix element corresponding to the ground-state transition where the incoherence of individual contributions is stronger for the pnMAVA than for the pnQRPA, and a 15% reduction in the magnitude of the matrix element is obtained for the pnMAVA. The 2νββ transition rate to the excited 0+ state is zero in a pnQRPA calculation, whereas the pnMAVA result is not far from the measured decay rate.
Mode-Ray Duality

Earlier results in the theory of terrestrial radio waves are applied to seismology. A partial field of the complete eigen-value solution for a sphere can be interpreted as real rays. Watson's transformation and the WKBJ approximation are employed to establish links between the index trio (l, m, n) of a mode and the corresponding parameters of the ray trajectory associated with this mode. It is shown that Snell's law for rays and Jean's formula are complementary. The condition of constructive interference is expressed as an integral equation for the eigen-frequencies _nω_l.
LOCALIZED THERMAL ANALYSIS USING A MINIATURIZED RESISTIVE PROBE

We describe a novel thermal characterization technique based on a differential arrangement, which achieves spatially localized calorimetric analysis. It involves the use of an active probe which acts both as a highly localized heat source and a thermometer. This ability opens the way for the implementation of scanning calorimetric microscopy where image contrast will be created from thermal analysis data. For a number of polymers we have recorded events such as glass transitions, meltings, recrystallizations and thermal decomposition within volumes of material estimated at a few μm3. The data obtained are compared with those obtained from conventional calorimetry and the events registered in both cases are found to match. For a full quantitative analysis of the results obtained, mathematical modelling of the operation of the technique, taking account of physical and other changes in materials, is required.
The swarm and the queen: towards a deterministic and adaptive particle swarm optimization

A very simple particle swarm optimization iterative algorithm is presented, with just one equation and one social/confidence parameter. We define a "no-hope" convergence criterion and a "rehope" method so that, from time to time, the swarm re-initializes its position, according to some gradient estimations of the objective function and to the previous re-initialization (it means it has a kind of very rudimentary memory). We then study two different cases, a quite "easy" one (the Alpine function) and a "difficult" one (the Banana function), but both just in dimension two. The process is improved by taking into account the swarm gravity center (the "queen") and the results are good enough so that it is certainly worthwhile trying the method on more complex problems.
Photovoltaic grid-connected inverter using two-switch buck-boost converter

This paper presents a two-stage photovoltaic grid-connected inverter. The first stage is a two-switch buck-boost circuit that performs various functions; tracking a maximum power point of the photovoltaic array and controlling current using fixed frequency current mode control technique; as well as reforming a direct current waveform to an absolute sinusoidal waveform. The second stage is a H-bridge switch that converts an absolute sinusoidal waveform to a sinusoidal waveform with a low harmonic distortion current and connected to utility. The system configuration is reliable using a single-chip DSP controller. Experimental results satisfy with simulation.
Geração de cenários sintéticos de energia e vazão para o planejamento da operação energética

Na analise economica de um projeto de desenvolvimento de um campo de petroleo sao levados em consideracao diversos elementos. Na parte de receitas o principal elemento e a curva de producao de petroleo. Os desembolsos podem ser divididos em dois grandes grupos: investimentos e custos operacionais. Os custos operacionais podem ser de forma geral divididos em tres grandes grupos: custos da plataforma, custos de logistica e custos de suporte em terra. Em maior ou menor grau cada um destes custos tem alguma dependencia com relacao ao nivel de producao do sistema. Neste trabalho sera apresentada uma tecnica que permitira a modelagem destas dependencias atraves da construcao de distribuicoes bivariadas. A tecnica e baseada no conceito de funcao de dependencia ou representacao uniforme, no qual a funcao de dependencia faz a ligacao das distribuicoes marginais univariadas com sua representacao multivariada. Estes resultados permitirao numa etapa posterior a ampliacao da analise de risco destes projetos.
Robustness of linear feedback control systems to unmodelled high-frequency dynamics

A basic issue in the control of linear time-invariant plants is the effect of neglected high-frequency dynamics on the performance, in particular on the closed-loop stability, of the control system. In this paper, the robustness of various output feedback control designs, based on a reduced-order model with neglected high-frequency dynamics, is investigated using singular perturbation techniques. A general robust design rule is to avoid static output feedback for systems with unmodelled high-frequency dynamics. From a frequency-domain standpoint, the robust design rule is to avoid closing high-frequency plant loops by using strictly proper controllers or controllers with a low-pass filtering property.
Jet impingement and the hydraulic jump on horizontal surfaces with anisotropic slip

This paper presents an analysis that describes the dynamics of laminar liquid jet impingement on horizontal surfaces with anisotropic slip. Due to slip at the surface and the anisotropy of its magnitude, the overall behavior departs notably from classical results. For the scenario considered the slip length varies as a function of the azimuthal coordinate and describes superhydrophobic surfaces micropatterned with alternating ribs and cavities. The thin film dynamics are modeled by a radial momentum analysis for a given jet Reynolds number and specified slip length and the influence of slip on the entire flow field is significant. In an average sense the thin film dynamics exhibit similarities to behavior that exists for a surface with isotropic slip. However, there are also important deviations that are a direct result of the azimuthally varying slip and these become more pronounced at higher Reynolds numbers and at greater slip lengths. The analysis also allows determination of the azimuthally varying r.
Highly excited levels of neutral ytterbium. II. Multichannel quantum defect analysis of odd- and even-parity spectra

For pt.I see ibid., vol.13, no.6, p.1073 (1980). Data on the bound even-parity spectrum of Yb have been presented in the preceding paper (Carnus et al., 1980). These data provide an excellent opportunity for the application of multichannel quantum defect theory (MQDT) to this spectrum. The bound even-parity J=0, 2 spectra and the bound odd-parity J=1 spectrum are analysed with MQDT models. The behaviour of the even-parity 4f146sns 1S0 (n>or=7) and 4f146snd 1.3D2 (n>or=8) Rydberg series perturbed by levels of the 4f146p2 and 4f135d6s6p configurations is well interpreted; in the same way the known bound levels of the 4f146snp 1.3P1 Rydberg series (n>or=12) perturbed by levels of the 4f135d26s configuration are well interpreted. The mutual interaction of the singlet and triplet levels of J=1 and J=2 Rydberg series is analysed. Some assignments of levels are changed and predicted energy values are given for many levels.
Second-order distributed feedback lasers based on films containing perylenediimide derivatives

The fabrication and characterization of highly efficient and photostable second-order distributed feedback lasers (DFB), based on polystyrene films doped with a perylenediimide (PDI) derivative as active laser material, is reported. DFB gratings were obtained via thermal nanoimprint lithography and transferred to SiO2 substrates by reactive ion etching. The influence of the PDI concentration on the laser performance has been investigated. The best results were obtained for the device based on the 0.5 wt% PDI-doped film, that emits at a wavelength of 571 nm, with a threshold of 2.5 μJ/pulse and a photostability halflife of around 500 min; i.e. 300000 pump pulses. The effectiveness of the DFB grating is evidenced by the decrease in threshold in two orders of magnitude with respect to the amplified spontaneous emission threshold obtained for a similar film deposited over a SiO2 substrate without grating.
In vivo assessment of pharmacological potentials of different fractions of Fagonia

Introduction : Hemostasis mechanism involves blood coagulation as one of the step which is responsible for blood clot formation that restricts blood flow at site of injury. By inhibiting coagulation cascade and reducing thrombus formation, several cardiovascular diseases (CVD) and atherosclerosis can be prevented. Traditionally, Fagonia olivieri (zygophyllaceae) is reported in the treatment of diabetes, coughs, blood purifier, cooling agent, blood vascular diseases, digestive system disorders and cancer in initial stages. Objectives : Different fractions of F. olivieri methanolic extract were evaluated in this study for their anticoagulatory, anti-inflammatory and antidepressant potentials. Methodology : Anticoagulatory, anti-inflammatory and antidepressant potentials of ethyl acetate, butanol and aqueous extracts of F. olivieri were assessed using capillary tube experiment, carrageenan induced paw edema test and forced swim test respectively. Results : The results of this investigation have revealed that ethyl acetate and butanol fractions possess significant anticoagulatory potentials as compared to control (P=0.0002). Butanol extract showed highest anti-inflammatory activity. Maximum anti-depressant activity was shown by ethyl acetate followed by n-butanol and aqueous extracts. Conclusion : Hence, it can be concluded that F. olivieri exhibits anticoagulatory, anti-inflammatory and antidepressant potentials which justifies its use for the treatment of various disorders particularly blood vascular diseases.