Miracle-dz/UniFAR-FTUs huggingface dataset:
Scattering of a plane wave by one-dimensional dielectric random rough surfaces—study with the curvilinear coordinate method

We present a method giving the bi-static scattering coefficient of a one-dimensional dielectric random rough surface illuminated by a plane wave. The theory is based on Maxwell's equations written in a nonorthogonal coordinate system. For each medium, this method leads to an eigenvalue system. The scattered field is expanded as a linear combination of eigensolutions satisfying the outgoing wave condition. The boundary conditions allow the diffraction amplitudes to be determined. The Monte Carlo technique is applied and the bi-static scattering coefficient is estimated by averaging the scattering amplitudes over several realizations. The results of a Gaussian random process with a Gaussian roughness spectrum are compared to published experimental and numerical data. Comparisons are conclusive.
Renormalisation group analysis of the phase transition in the 2D Coulomb gas, Sine-Gordon theory and XY-model

A systematic renormalisation group technique for studying the 2D sine-Gordon theory (Coulomb gas, XY model) near its phase transition is presented. The new results are (a) higher order terms in the flow equations beyond those of Kosterlitz (1974) give rise to a new universal quantity; (b) this in turn gives the universal form as well as the relative coefficient of the next-to-leading term in the correlation function of the XY model; (c) the free energy (1PI vacuum sum) is calculated after the singularity at beta 2=4 pi is treated; (d) vortices with multiple charges are shown to be irrelevant; (e) symmetry breaking fields are analysed systematically. The main ideas that the sine-Gordon theory can be defined as a double expansion in alpha (fugacity) and delta = beta 2/8 pi -1 (distance from the critical temperature at alpha =0). Wave-function and coupling constant ( alpha ) renormalisations are necessary and sufficient, around beta 2=8 pi where cos phi acquires dimension 2, for functions with elementary SG fields. This gives rise to renormalisation of beta . The renormalisability is proved to the order calculated in the context of the SG theory, and in general, by using the equivalence to the Thirring-Schwinger model. The renormalised beta 2 plays a role analogous to the dimension in a phi 4 theory-8 pi being the critical dimension. beta 2>8 pi gives an infrared asymptotically free theory which leads to the well-known fixed line. The infrared properties are understood by analogy with the non-linear sigma model.
Testing the Empirical Relation between Ultraviolet Color and Attenuation of Galaxies

We test the empirical relation between ultraviolet color and attenuation as derived for starburst galaxies with a wide assortment of galaxy types detected by the Galaxy Evolution Explorer and find that it systematically overestimates the far-ultraviolet attenuation of our sample by ~0.5 mag. Our efforts to find an additional parameter that could improve the starburst reddening relation were unsuccessful. In particular, UV - Ks colors (in nonmatching apertures) show no correlation with the offset from the starburst reddening relation, suggesting either that UV - Ks colors are a poor tracer of present to past average star formation history (the "b" parameter) or that the intrinsic dust distribution/geometry may be responsible for moving galaxies off the correlation. It is possible to reduce the systematic overestimate of AFUV by using the linear correlation derived from our sample, which simply lowers the starburst predicted values of AFUV by 0.58 mag. The scatter, however, remains large at 0.89 mag.
On the vortex formation in the mixing layer behind dunes

Flow processes in the mixing layer behind dunes provide the feedback between flow, sediment transport and the bed forms, which is assumed to be responsible for the development and persistence of dunes. It is attempted to classify these flow processes in terms of coherent structures, in which the vorticity of the upstream boundary layer is concentrated. Information from flow visualization is used to describe these vortical structures. The literature was reviewed to search for theoretical and experimental results of similar flow situations, which can provide the essential concepts.
Transfer functions of solid vocal-tract models constructed from ATR MRI database of Japanese vowel production

The ATR MRI database of Japanese vowel production was used to evaluate the acoustic characteristics of the vocal tract for the five Japanese vowels through the measurements of frequency responses from solid vocal-tract models formed by a stereolithographic technique. The database includes speech sounds as well as volumetric magnetic resonance imaging (MRI) data, but the speech sounds were recorded separately from the acquisition MRI data; therefore, their speech spectra are not appropriate for use as the reference for the transfer functions of the vocal tract. A time-stretched pulse signal generated from a horn driver unit was introduced into the physical model at the lips, and the response signals of the models were recorded at the model’s glottis. In the measurements, the glottis of the models was sealed with a plastic plate, and the response signals were measured from a small hole in the plate using a probe microphone. This method permits accurate measurement of the transfer functions of the vocal tract under a closed-glottis condition. The resulting transfer functions of the five Japanese vowels provide a benchmark for testing numerical analysis methods that have been used to study vocal-tract acoustics, although the solid wall decreases the frequencies of lower resonances.
Electromagnetism and the holomorphic properties of spacetime

The Cauchy–Riemann equations of holomorphy are extended to fields in higher‐dimensional spaces in a framework of Clifford algebras. The equations of holomorphy in Minkowski spacetime turn out to be the Maxwell equations in vacuum. The Lorentz gauge condition is a result of the holomorphy. Sources can be included in an extension of the residue theorem, where charges correspond to the residues.
Semiclassical molecular dynamics for strongly coupled Coulomb systems

Based on the time‐dependent variational principle for a Hartree wave function, a semiclassical approximation for a strongly correlated plasma is derived. This procedure maps the quantum dynamical problem to a classical one with one additional degree of freedom per particle and is considered the natural extension of classical molecular dynamics. As a test case, a single electron in a Coulomb potential is studied. For the full many‐body problem the pair distribution function, the velocity autocorrelation function, the conductivity, and the diffusion constants are calculated for a plasma. We also consider liquid molecular hydrogen and lithium as a further test case which is sensitive to the treatment of the Pauli exclusion principle.
Fabrication and test of the LDX levitation coil

The Levitated Dipole Experiment (LDX) was designed by Columbia University and the Massachusetts Institute of Technology to investigate plasma confinement within a dipole magnetic field. The experiment consists of a 5 m diameter by 3 m tall vacuum chamber and three superconductor coils: a Nb/sub 3/Sn Floating Coil that provides the dipole field for plasma confinement; a NbTi Charging Coil that inductively charges and discharges the Floating Coil current; and a high temperature superconductor (Bi-2223) Levitation Coil that electromagnetically supports the weight of the 620 kg Floating Coil and controls its vertical position within the vacuum chamber. LDX is the first US plasma confinement experiment to use a high temperature superconductor coil. The use of high temperature superconductor minimizes the electrical and cooling power needed for levitation, allowing additional power for plasma heating. The levitation coil is a 2800 turn, 1.3 m outer diameter, double pancake winding. It is designed to operate at up to 150 A current at 20 K and is cooled by a combination of one stage cryocooler and liquid nitrogen cooled radiation shield. This paper provides details for the design, fabrication and test of the coil.
Facial Structure in Operator Algebra Theory

We give a complete description of the closed faces in twelve kinds of convex sets that appear in operator algebra theory. These consist of positive parts of unit balls for C*-algebras and their dual spaces, and for von Neumann algebras and their pre-duals; of self-adjoint parts of unit balls in the same four classes and finally of general unit balls in the four classes. All these faces are shown to be semi-exposed and naturally paired with a polar face in the dual (or pre-dual) space
Two-photon self-induced transparency in a resonant medium. II. Transient pulse behaviour

For pt.I see ibid., vol.8, no.3, 339 (1975). The transient behaviour of two short optical pulses in two-photon coherent propagation is obtained by calculating numerically the coherent propagation equations which couple the two electromagnetic pulses and the atomic system in self-consistent fashion. The coherent interaction of the two different frequency pulses gives rise to lossless propagation in the absorptive medium. This description is characterized by a two-photon area theorem. Novel coherent propagation effects of peak amplification and multiple pulse breakup are found. These effects are ascribed to two-photon self-induced transparency analogous to that of a one-photon transition in a two-level system. A difference of input intensity between the two different frequency pulses yields curious modulation effects involving sharp peak amplification and marked pulse breakup for the low-intensity input. In contrast, the high-intensity input pulse displays a smooth variation with distance and time. Low-loss pulse transmission above threshold, and pulse advance and delay are found for the present case in contrast to that for one-photon self-induced transparency.
Recent Changes of Arctic Multiyear Sea Ice Coverage and the Likely Causes

aMerICaN MeTeOrOLOGICaL SOCIeTy | 145 AffiliAtions: Polyakov and Walsh—International Arctic Research Center, University of Alaska Fairbanks, Fairbanks, Alaska; kWok—Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California CoRREsPonDinG AUtHoR: Igor V. Polyakov, International Arctic Research Center, University of Alaska Fairbanks, P.O. Box 757335, Fairbanks, AK 99775 E-mail: igor@iarc.uaf. edu
Optimal positive airway pressure requirement and polysomnography indices of obstructive sleep apnea severity in the Saudi population

CONTEXT: Positive airway pressure (PAP) is the first-line therapy for obstructive sleep apnea (OSA). Overnight PAP titration for determining optimal PAP requirements is expensive and often inconvenient. Prediction of optimal PAP requirements from diagnostic polysomnography via mathematical equations is possible but variable across populations. AIMS: We aimed to (1) determine the optimal PAP requirement, (2) determine differences in optimal PAP requirements across OSA severity groups, (3) determine the relationship between optimal PAP requirement and diagnostic polysomnography measurements of OSA severity, and (4) develop a pilot equation to predict the optimal PAP requirement from diagnostic polysomnography in a sample from the Saudi population. METHODS: We analyzed records pertaining to adult OSA patients (n = 215; 63% of males) who underwent standardized diagnostic and titration polysomnography in our sleep laboratory between 2015 and 2019. Demographic, anthropometric, and clinical information were also collected for the analysis. Inferential statistics were performed for comparisons between diagnostic and titration studies and between OSA severity groups. Regression analyses were also performed to determine the potential predictors of optimal PAP requirements. Data were presented as the mean (± standard deviation) or median (25th–75th quartiles) according to normality. RESULTS: The median optimal PAP requirement was 13 (9–17) cmH2O. The optimal PAP requirement was significantly greater for male versus female participants (14 [10–17] vs. 12 [8–16] cmH2O) and for participants with severe OSA (16 [12–20] cmH2O, n = 119) versus those with moderate (11 [8–14] cmH2O, n = 63) or mild (9 [7–12] cmH2O, n = 33) OSA. When combined, nadir oxygen saturation, oxygen desaturation index, and arousal index could be used to predict the optimal PAP requirement (R2 = 0.39, F = 34.0, P < 0.001). CONCLUSIONS: The optimal PAP requirement in the Saudi population is relatively high and directly correlated with OSA severity. Diagnostic polysomnography measurements of OSA severity predicted the optimal PAP requirement in this sample. Prospective validation is warranted.
Two‐Dimensional Gaseous Detonations: Velocity Deficit

The measured velocity of gaseous detonation waves is less than that predicted by the Chapman‐Jouguet plane wave theory. The velocity deficit (difference between theoretical and measured velocities) has been found earlier to vary inversely with the tube diameter and initial pressure. A quantitative explanation of this effect is advanced by determining the growth of the viscous boundary layer on the tube wall and its effect upon the flow in the reaction zone of the detonation front. It is proposed that the boundary layer displacement effect within the reaction zone produces a uniform flow divergence throughout the detonation front. The velocity deficit due to this two‐dimensional flow is determined, using measured values of reaction zone thickness. The agreement of the velocity deficit with measured values is within a factor of two for the five hydrogen‐oxygen‐inert gas mixtures and one acetylene‐oxygen mixture for which sufficient data are available.
Factors Affecting the Providing of Sexual Health Services by Midwives: A Qualitative Research in Iran

Background: Sexual health is one of the most important aspects of health. In Iran, most services associated with reproductive and sexual health are provided by midwives at health centers. As different factors are effective in providing care services associated with sexual health, the present study aims to investigate the factors affecting the provision of sexual health services by midwives. Materials and Methods: In this qualitative content analysis study, data were collected by conducting in-depth interviews with 16 midwives, 7 key informants, and 6 stakeholders. Besides, the sampling method was purposeful, and data analysis was conducted using conventional content analysis and MAXQDA software. Results: After analyzing the content of the qualitative data, two themes were extracted, which included facilitators of and barriers to providing sexual health services by midwives. Conclusions: By modifying educational curricula, providing in-service training, and adopting appropriate policies, barriers for providing accessible sexual health services by midwives can be reduced.
On the relationship between coronal heating, magnetic flux, and the density of the solar wind

[1] The stark differences between the current solar minimum and the previous one offer a unique opportunity to develop new constraints on mechanisms for heating and acceleration of the solar wind. We have used a combination of numerical simulations and analysis of remote solar and in situ observations to infer that the coronal heating rate, H, scales with the average magnetic field strength within a coronal hole, Bch. This was accomplished in three steps. First, we analyzed Ulysses measurements made during its first and third orbit southern and northern polar passes (i.e., during near-solar minimum conditions) to deduce a linear relationship between proton number density (np) and radial magnetic field strength (Br) in the high-speed quiescent solar wind, consistent with the results of McComas et al. (2008) and Ebert et al. (2009). Second, we used Wilcox Solar Observatory measurements of the photospheric magnetic field to show that the magnetic field strength within coronal holes (Bch) is approximately correlated with the strength of the interplanetary field at the location of Ulysses. Third, we used hydrodynamic simulations to show that np in the solar wind scales linearly with H. Taken together, these results imply the chain: H ∝ np ∝ Br ∝ Bch. We also explored ideas that the correlation between np and Br could have resulted from interplanetary processes, or from the superradial expansion of the coronal magnetic field close to the Sun, but find that neither possibility can produce the observed relationship. The derived heating relationship is consistent with (1) empirical heating laws derived for closed-field line regions and (2) theoretical models aimed at understanding both the heating and acceleration of the solar wind.
Photorefractive intermodal exchangers in optical fiber

Photorefractive intermodal exchangers (PRIME) in optical fiber are optically written refractive index gratings that couple two copropagating modes of the fiber. The author examines the characteristic feature of these devices. He shows how mode coupling automatically occurs at the wavelength lambda /sub irr/ used to write the refractive index grating, and calculates the bandwidth of mode coupling as a function of the fiber parameters. A discussion is presented to determine under what conditions mode coupling can also be obtained at wavelengths different from lambda /sub irr/, and between modes other than those used to write the grating. The refractive index change required for 100% power transfer over a given length is also calculated for different situations. >
How to have passively Q-switched lasers self-pulsate

The rate equations of passively Q-switched lasers are considered. These equations represent the dynamics of the photon number in the laser cavity, the population inversion of the laser, and the ground-state population of the saturable absorber, when excited by an input (pumping rate). Having the rate equations, (i) it is shown that the laser is the bounded-input bounded-state (BIBS) and the bounded-input bounded-output (BIBO) stable; (ii) the amplitudes of step inputs are determined for which all equilibrium points of the laser are unstable. The boundedness of the laser output and the instability of its equilibrium points imply that the laser can have a periodic, a quasi-periodic, or a chaotic output. When the output is periodic, the laser is self-pulsating, which is the desirable behavior of the laser.
An Evaluation of Temporal Distributions of High, Low, and Zero Cohort Morbidity of Cumulative First Treatment Bovine Respiratory Disease and Their Associations with Demographic, Health, and Performance Outcomes in US Feedlot Cattle

Simple Summary Cluster analyses were performed on the cohort temporal distributions of bovine respiratory disease BRD. Results illustrated that the optimal number of clusters differed by the level of morbidity within the cohort. Different temporal patterns of cumulative first treatment BRD which could influence disease prevention and control techniques were identified. Descriptive and statistical associations of risk factors for each cluster better describes the cattle represented within each cluster. More research is needed to understand the potential economic impact each cluster has on feedlot production. Improved understanding of cohort timing and magnitude of BRD could potentially identify interventions to mitigate disease burden and economic impacts. Abstract Timing and magnitude of bovine respiratory disease (BRD) can impact intervention and overall economics of cattle on feed. Furthermore, there is a need to better describe when cattle are being treated for BRD. The first objective was to perform a cluster analysis on the temporal distributions of cumulative first treatment BRD from HIGH (≥15% of cattle received treated for BRD) and LOW cohorts (>0 and <15% of cattle received treated for BRD) to assess cohort-level timing (days on feed) of BRD first treatments. The second objective was to determine associations among cluster groups (temporal patterns) and demographic risk factors, health outcomes, and performance. Cluster analysis determined that optimal number of clustering groups for the HIGH morbidity cohort was six clusters and LOW morbidity cohort was seven clusters. Cohorts with zero BRD treatment records were added for statistical comparisons. Total death loss, BRD morbidity, average daily gain (ADG), railing rate, days to 50% BRD, cattle received, shrink, arrival weight, and sex were associated with temporal groups (p < 0.05). These data could be used as a tool for earlier identification and potential interventions for cohorts based on the BRD temporal pattern.
Parametrization of Eddy Mass Transport in the Arctic Seas Based on the Sensitivity Analysis of Large-Scale Flows

The characteristics of eddy mass transport are estimated depending on the values of the parameters of a large-scale flow that forms under the conditions of the shelf seas in the Arctic. For this, the results of numerical simulation of the Kara Sea with a horizontal resolution permitting the development of mesoscale eddies are used. The multiple realizations of eddy mass flux resulting from a numerical experiment are considered as a statistical sample and are analyzed using methods of sensitivity study and clustering of sample elements. Functional dependencies are obtained that are closest to the simulated distributions of quantities. These expressions make it possible, within the framework of large-scale models, to evaluate the characteristics of the cross-isobathic eddy mass transport in the diffusion approximation with a counter-gradient flux. Numerical experiments using the SibCIOM model showed that areas along the Fram branch of the Atlantic waters trajectory in the Arctic as well as the shelf of the East Siberian and Laptev seas with adjacent deep water areas are most sensitive to the proposed parametrization of eddy exchanges. Accounting for counter-gradient eddy fluxes turned out to be less important.
Ecology and behaviour of the franciscana (Pontoporia blainvillei) in Bahia Anegada, Argentina

From January 1993 to July 1997, franciscana sightings were recorded from shore-based stations and vessels at Bahfa Anegada, Argentina. In total, 321 hours were spent in direct observation of dolphins following the Ad libitum and Focal sampling methods. The present study provides information on the ecology and behaviour of the franciscana in the study area. A total of 25lsightings were made and the number of sightings per unit effort (SPUE) was significantly greater during spring (p = 0.001). Dolphins were recorded at a mean distance from shore of 3.2km (0.4km-10.7km), although they were found at a significantly greater mean distance from shore during winter (p = 0.005). More sightings were recorded during flood tide than during ebb tide (p = 0.016). A higher SPUE was also recorded from a sailboat than from a motor boat (p = 0.005). Group size was small, ranging from 1 to 6 individuals. Calves were recorded during spring and summer and only one calf was observed per group. The behaviour showed a seasonal pattern with co-operative feeding and travelling activities increasing during winter. Tide and depth also influenced behaviour. Co-operative feeding increased during flood tide, while travelling decreased. The behavioural ecology of the franciscana appears similar to that of other coastal and river dolphins. This study represents the first attempts to understand the behaviour of the franciscana in its natural habitat.