Miracle-dz/UniFAR-FTUs huggingface dataset:
Bond strength of composite to dentin: effect of acid etching and laser irradiation through an uncured self-etch adhesive system

This study evaluated the effect on micro-tensile bond strength (µ-TBS) of laser irradiation of etched/unetched dentin through an uncured self-etching adhesive. Dentinal surfaces were treated with Clearfil SE Bond Adhesive (CSE) either according to the manufacturer’s instructions (CSE) or without applying the primer (CSE/NP). The dentin was irradiated through the uncured adhesive, using an Nd:YAG laser at 0.75 or 1 W power settings. The adhesive was cured, composite crowns were built up, and the teeth were sectioned into beams (0.49 mm2) to be stressed under tension. Data were analyzed using one-way ANOVA and Tukey statistics (α = 5%). Dentin of the fractured specimens and the interfaces of untested beams were observed under scanning electron microscopy (SEM). The results showed that non-etched irradiated surfaces presented higher µ-TBS than etched and irradiated surfaces (p < 0.05). Laser irradiation alone did not lead to differences in µ-TBS (p > 0.05). SEM showed solidification globules on the surfaces of the specimens. The interfaces were similar on irradiated and non-irradiated surfaces. Laser irradiation of dentin through the uncured adhesive did not lead to higher µ-TBS when compared to the suggested manufacturer’s technique. However, this treatment brought benefits when performed on unetched dentin, since bond strengths were higher when compared to etched dentin.
Scanning tunneling microscope instrumentation

A review is presented of the basic operating principles of scanning tunneling microscopy and spectroscopy. The physical and electronic design of the scanning tunneling microscope is discussed, and other new microscopes using similar concepts are described. Some examples of the past accomplishments of scanning tunneling microscopy are given, and prospects for future applications are assessed.
Numerical Calculation of Time‐Dependent Viscous Incompressible Flow of Fluid with Free Surface

A new technique is described for the numerical investigation of the time‐dependent flow of an incompressible fluid, the boundary of which is partially confined and partially free. The full Navier‐Stokes equations are written in finite‐difference form, and the solution is accomplished by finite‐time‐step advancement. The primary dependent variables are the pressure and the velocity components. Also used is a set of marker particles which move with the fluid. The technique is called the marker and cell method. Some examples of the application of this method are presented. All non‐linear effects are completely included, and the transient aspects can be computed for as much elapsed time as desired.
A Numerical Study of Typhoon Megi (2010). Part I: Rapid Intensification

AbstractTyphoon Megi (15W) was the most powerful and longest-lived tropical cyclone (TC) over the western North Pacific during 2010. While it shared many common features of TCs that crossed Luzon Island in the northern Philippines, Megi experienced unique intensity and structural changes, which were reproduced reasonably well in a simulation using the Advanced Research Weather Research and Forecasting Model (ARW-WRF) with both dynamical initialization and large-scale spectral nudging. In this paper processes responsible for the rapid intensification (RI) of the modeled Megi before it made landfall over Luzon Island were analyzed. The results show that Megi experienced RI over the warm ocean with high ocean heat content and decreasing environmental vertical shear. The onset of RI was triggered by convective bursts (CBs), which penetrate into the upper troposphere, leading to the upper-tropospheric warming and the formation of the upper-level warm core. In turn, CBs with their roots inside of the eyewall in.
The Lyman and Werner band systems of molecular hydrogen

Abstract Line positions and emission probabilities of the Lyman and Werner band systems of molecular hydrogen have been calculated by solving a system of four coupled Schrodinger equations. We have been able to identify several thousand new lines emitted by a low pressure discharge in H2 from 172 nm down to 78 nm. Many high-J energy levels are reported for the first time. Molecular constants are derived for the (unperturbed) 1Π−u states. Several examples demonstrate that the emission spectrum is very significantly different from that which could be deduced from a knowledge of only the absorption spectrum.
Problems in simulating the stratocumulus-topped boundary layer with a third-order closure model

Abstract We have used a third-order closure model, proposed by Andre and others, in which the time-rate-change terms, the relaxation and rapid effects for the pressure-related terms, and the clipping approximation are included along with the quasi-normal closure, to study turbulence in a cloudy layer that is cooled radiatively from above. The results show a spurious oscillation, with the largest amplitude near the inversion. An analysis of the problem shows that the oscillation arises from the mean-gradient and buoyancy terms of the triple-moment equations; these terms are largest near the cloud top. In the stably stratified layer just above the interface, turbulence can excite gravity waves. A model with a closure assumption for the pressure-related terms, not taking into consideration the transport of wave energy, can possibly generate spurious oscillations. We attempted to damp the oscillation by introducing diffusion terms into the triple-moment equations. With a reasonable choice of the diffusion coe.
Effects of Coastal Orography on Landfalling Cold Fronts. Part I: Dry, Inviscid Dynamics

Abstract In this study, the interaction of cold fronts with idealized coastal terrain typical of the western United States and Canada is considered. Two issues are examined. First, what are the factors that determine the strength of the coastal winds, and second, what are the orographic effects on the frontal evolution? To address these issues, the authors utilize a two-dimensional, Boussinesq terrain-following coordinate numerical model in which a uniform prescribed flow is forced to move over a plateau. The resultant across-mountain velocities are characterized by a zone of strongly decelerated flow upstream of the windward slope and a train of inertia-gravity waves downstream. A barrier-jet oriented parallel to the mountain is produced by the Coriolis force. The variations of the magnitude of the upstream deceleration and the barrier jet over a wide range of Froude numbers and Rossby numbers are described. Steady, linear theory applied to flow over a plateau shows that the upstream deceleration is dete.
Quantum dimension as entanglement entropy in two dimensional conformal field theories

We study the entanglement entropy of excited states in two-dimensional conformal field theories (CFTs). In particular, we consider excited states obtained by acting on a vacuum with primary operators. We show that the entanglement entropy increases by a finite constant amount under its time evolution. Moreover, in rational conformal field theories, we prove that this increase of the (both Renyi and von Neumann) entanglement entropy always coincides with the log of the quantum dimension of the primary operator.
An Evolutionary Newton Method for Shape Reconstruction

We consider the problem to reconstruct the location and shape of an unknown number of sound-soft obstacles from the far ﬁeld pattern of scattered acoustic waves. First, the point source method is used to generate an estimate for the area where the obstacles are located. In its simplest form the point source method will provide the convex hull of the set of obstacles. Then, we investigate a novel evolutionary Newton algorithm which integrates the Newton scheme with elements of an evolutionary approach. The Newton method is an eﬃcient local method to ﬁnd obstacles if the number, approximate location and shape of all obstacles is known. With-out this knowledge the method quickly runs into local minima or diverges. The evolutionary algorithm is capable of ﬁnding the number of obstacles, their location and shape. However, in its typical form the algorithm is not appropriate for inverse scattering problems due to the expensive evaluation of the forward scattering map. Evolutionary algorithms usually use a large number of target function evaluations on a population of solutions and converge slowly. We will employ principles of both algorithms to formulate a novel evolutionary Newton scheme which does combine the strength of both evolutionary methods and the Newton scheme and does avoid their particular limitations. This shows that a combination of statistical and deterministical reconstruction methods can be used to signiﬁcantly extend the range of the algorithms of both areas. In our last part we illustrate the feasibility of the scheme by numerical examples.
Chaotic behavior in the Josephson equations with periodic force

The goal of this paper is to prove analytically the existence of chaos, for certain parameter values, in the dynamics of the Josephson equations \[\text{(E)(F)}\qquad\ddot \phi + \sin \phi + k\sin 2\phi + \begin{pmatrix} A( \cos \phi + 2k\cos 2\phi ) \\ \alpha \end{pmatrix} \dot \phi = \beta + B\sin \omega t\]. Combining previous results with new results, a more complete description of dynamics of the Josephson equations is obtained.
Interpretation of the Three-Parameter Testlet Response Model and Information Function

The testlet response model is designed for handling items that are clustered, such as those embedded within the same reading passage. Although the testlet is a powerful tool for handling item clusters in educational and psychological testing, the interpretations of its item parameters, the conditional correlation between item pairs, and the testlet information function are not always clear. For example, the a-parameter in a testlet response model, which is sometimes referred to as the discrimination parameter and interpreted in the conventional way, is often directly compared to the a-parameter in standard item response models. In this article, it is argued that despite the deceptively similar forms of the a-parameters, such interpretation and comparison can be misleading. A marginalized version of the testlet model is introduced to derive quantities that are comparable to standard item response models. This mean (marginalization) of the function approach is contrasted with the temptingly simple but inappropriate function of the mean approach, in which the testlet effect is set to its mean of zero in respective equations for item response, correlation, and information functions. Testlet data collected from a science assessment within the National Assessment of Educational Progress are used to illustrate the subtle differences in the interpretations of the various response models.
Changes in the Low-Level Kinematic and Thermodynamic Structure of Hurricane Alicia (1983) at Landfall

Abstract Aircraft, land station, and buoy data were composited with respect to the center of Hurricane Alicia (1983) for three 8-h periods corresponding to prelandfall in the open Gulf of Mexico, landfall in the Galveston area, and postlandfall in the vicinity of Houston. Comparison of the wind analyses before, during, and after landfall emphasizes the land-sea frictional asymmetry at landfall. In addition, other asymmetries in the surface wind field and differences between the flight-level and the surface wind fields are revealed. The asymmetric structure of the surface wind field may be interpreted as having resulted from the combined effects of land-sea roughness differences, background environmental flow, and storm translation. The land-sea frictional difference acted to oppose the mean vortex flow over land and reinforce it over water. The southwest background environmental flow acted nearly parallel to the coastline, producing surface inflow on the left side and outflow on the right side, while the .
Meteorological effects of the solar eclipse of 11 August 1999

A rare and spectacular total solar eclipse crossed the south-west tip of Britain, sweeping swiftly onwards into continental Europe, during the late morning of 11 August 1999 (Fig. 1). (The last total solar eclipse in the UK barely clipped Shetland in 1954, and the next will not occur until 2081, in the Channel Islands.) The rest of the country was subjected to a deep partial eclipse. For most of Britain, the eclipse lasted from about 1000 to 1235 BST, with maximum obscuration of the Sun by the Moon between about 1112 and 1122BST, exact timings being later further east (Bell 1997). Unfortunately the surface pressure analysis (Fig. 2) shows a weak low approaching Ireland, with an associated cloudy trough hitting the south-west peninsula just at the crucial hour when avid eclipse watchers could well have done without this nuisance! Ahead of the front, winds were light in a slack south or south-east airflow resulting from a weak transient ridge. Cloud conditions further east and north in Britain were still patchy but generally clearer (Fig. zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA3). While many of the south coast resorts east of the Isle of Wight had largely clear skies, with typically 7 or 8 hours of bright sunshine, those further west were mainly cloudy with only an hour or less of sunshine.
The motion of ions specularly reflected off a quasi-parallel shock in the presence of large-amplitude, monochromatic MHD waves

A test particle model is used to study the motion of ions specularly reflected off a shock in the presence of large-amplitude, monochromatic, transverse MHD waves. The characteristics of the motion depend on the frequency, wavelength, phase, and amplitude of the wave that is being convected into the shock. For low wave frequencies and long wavelengths (ω′ ≪ ion gyrofrequency, λ ≫ ion gyroradius), the ion motion depends only upon θBn(ϕ0), the instantaneous angle between the total magnetic field at the shock (ambient + wave) and the shock normal. For high wave frequencies and short wavelengths (ω′ ≫ ion gyrofrequency, λ ≪ ion gyroradius), the ion motion depends only upon θBn0, the angle between the ambient magnetic field and the shock normal. For intermediate frequencies and wavelengths, including those of interest in the region upstream from the earth';s bow shock (ω′ ∼ ion gyrofrequency, λ ∼ ion gyroradius), no simple θBn0 or θBn(ϕ0)criterion for the ion motion is found. For example, at intermediate frequencies, the motion depends both on θBn(ϕ0) and θBn0 as well as upon b/B, the ratio of the wave amplitude to ambient magnetic field strength. In general, the presence of upstream waves inhibits the escape of specularly reflected ions from the shock, the effect being greatest when the wave amplitude is large. Other properties of ion motion that are affected by the presence of an MHD wave include the propagation time of an ion from the shock to a given upstream distance, the time variation of the gyrospeed and guiding center speed, and the energy upon return to the shock.
Evaluation of use of magnetically bistable microwires for magnetic labels

The dynamics of the magnetization reversal by means of head‐to‐head domain‐wall propagation is investigated both experimentally and theoretically for magnetic labels made from Fe‐rich bistable glass‐coated microwires. It is shown that the amplitudes of the electromagnetic harmonics generated by bistable Fe‐rich magnetic labels of the length 1–4 cm with metallic nuclear diameter of 10–20 µm are more than 5 times larger than that of similar labels made of Co‐rich microwires having high permeability and low coercive force. The electromagnetic harmonics can be detected at the distances up to 15–20 cm from the magnetic label at the signal‐to‐noise ratio not lower than 2.0.
How to do a Weibull statistical analysis of flexural strength data: application to AlON, diamond, zinc selenide, and zinc sulfide

For the purpose of assessing the strength of engineering ceramics, it is common practice to interpret the measured stresses at fracture in the light of a semi-empirical expression derived from Weibull's theory of brittle fracture, i.e., ln[-ln(1-P)]=-mln((sigma) N)+mln((sigma) ), where P is the cumulative failure probability, (sigma) is the applied tensile stress, m is the Weibull modulus, and (sigma) N is the nominal strength. The strength of (sigma) N, however, does not represent a true measure because it depends not only on the test method but also on the size of the volume or the surface subjected to tensile stresses. In this paper we intend to first clarify issues relating to the application of Weibull's theory of fracture and then make use of the theory to assess the results of equibiaxial flexure testing that was carried out on polycrystalline infrared-transmitting materials. These materials are brittle ceramics, which most frequently fail as a consequence of tensile stresses acting on surface flaws. Since equibiaxial flexure testing is the preferred method of measuring the strength of optical ceramics, we propose to formulate the failure-probability equation in terms of a characteristic strength, (sigma) C, for biaxial loadings, i.e., P=1-exp{-(pi) (ro/cm)2[(Gamma) (1+1/m)]m((sigma) /(sigma) C)m}, where ro is the radius of the loading ring (in centimeter) and (Gamma) (z) designates the gamma function. A Weibull statistical analysis of equibiaxial strength data thus amounts to obtaining the parameters m and (sigma) C, which is best done by directly fitting estimated Pi vs i data to the failure-probability equation; this procedure avoids distorting the distribution through logarithmic linearization and can be implemented by performing a non-linear bivariate regression. Concentric- ring fracture testing performed on five sets of Raytran materials validates the procedure in the sense that the two parameters model appears to describe the experimental failure-probability distributions remarkably well. Specifically, we demonstrate that the wide divergence in published CVD-diamond strength data reflects the poor Weibull modulus of this material and must be attributed to the size effect rather than the quality of the deposits. Finally, the problem of obtaining correct failure stresses from the measured failure loads is examined in the Appendix.
Structural and electronic properties of III-V bismuth compounds

We have performed ab initio self-consistent calculations based on the full potential linear augmented plane-wave method with the generalized gradient approximation to investigate the structural and the electronic properties of the less known bismuth III-V compounds: BBi, AlBi, GaBi, and InBi. Ground state parameters are computed and compared with available theoretical and experimental works. The zinc-blende phase is found to be the most stable for BBi, AlBi, and GaBi, while InBi prefers the tetragonal PbO structure. The relativistic contraction of the $6s$ orbital of Bi has strong effect on the band structure of III-Bi compounds, which exhibits some features that differ considerably from those of typical III-V semiconductors. In particular, we found an inverted band gap, which reflects a semimetallic character of these systems. Their bonding nature is analyzed in terms of valence charge density transfer, showing three different natures of the bond. Besides, the calculated valence charge density for BBi shows an anomalous behavior characterized by a charge transfer toward the cation B atom, while the others III-Bi behave as the typical III-V compounds with a small charge transfer to the anion bismuth atom.
The hochschild cohomology ring of a modular group algebra: the commutative case

Let k be a field of characteristic P >0 and let G be a finite abelian group. We determine the structure of the Hochschild cohomology ring of the group algebra k G. Moreover, we prove that for any finite group G the Krull dimension of H H *(k G) equals the p-rank of G.
A closure model for transient heat conduction in porous media

Equations governing the transient heat conduction in porous materials consisting of solids and fluids of different thermal properties were derived with a volumetric average scheme under the assumption of nonthermal equilibrium. The derivation leads to a macroscopic two-equation system which requires the closure modeling of new unknown terms due to interfacial transport, namely, the tortuosity term and the interfacial heat transfer term. Closure relations were obtained from the microscopic equations for temperature fluctuation under quasi-steady assumption. The closure coefficients appeared in the closure relations then depend on the media geometry as well as thermal properties. To demonstrate these dependencies, the closure coefficient for the thermal tortuosity is evaluated based on the effective stagnant thermal conductivity model proposed by Hsu et al. (1995) for periodically packed cubes, and the coefficient for interfacial heat transfer based on a quasi-steady heat conduction of dispersed spheres immersed in fluids. The salient features as well as the applicability and limitation of the newly proposed transient heat conduction model were discussed.
Comparison of sunspot area data bases

Sunspot area measurements play an important role in the studies of sunspot groups and variations in solar irradiance. However, the measured areas may be burdened with systematic and random errors, which may affect the results in these fields. Mainly the total solar irradiance models can be improved by using more precise area data. In order to choose the most appropriate area data for a given study or create a homogeneous composite area data base, there is a need to compare the sunspot areas provided by different observatories. In this study we statistically investigated all the available corrected sunspot area data bases for the years 1986 and 1987. We find that the photographic data bases are in good agreement with each other but there are important systematic differences between the photographic and sunspot drawings data bases. We give the characteristic parameters for the systematic and random errors as well as the possible reasons for them.
Heliographic latitude dependence of the Sun's irradiance

It has recently been reported that the total radiative emission variations from solar type stars exceeds the currently observed solar constant variations (from spacecraft over the last decade) by a factor near 4. Aside from other remote alternatives, this suggests three clear possibilities: (1) the Sun may undergo irradiance variations several times larger than any we have seen; (2) our Sun is highly unusual with regard to its radiative output; or (3) our terrestrial position in the heliosphere provides a special vantage point which reduces the observed solar irradiance variations. We investigate the last possibility by considering the influence of observer latitude upon calculated irradiance variations using a simple model for emission from solar contrast features. We consider modeled sunspots, faculae, and network structures. As the latitude angle of the observer rises relative to the heliographic equator, sunspot deficit contributions diminish and facular plus network contributions escalate. We find that the observing latitude can influence the irradiance variations by a factor near 6. When we integrate the irradiance variations, over the celestial sphere, they average to 3 times the terrestrial effect, suggesting that the solar cycle luminosity variations are proportionally, 3 times larger than the solar constant variations. Thus we suggest the Sun's luminosity output varies even more strongly with the solar cycle than is apparent in the solar constant variations. The influence of the observer viewing angle relative to stellar spin axis, studied here, may be possible to investigate with a thorough statistical examination of other solar type stars. Additionally, the rotational modulation due to active regions (as a function of observer viewing angle) may also be a valuable area for future investigation.