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Affected by the soaking of goaf water, the reduced bearing capacity of section coal pillar is not conducive to disaster prevention and control. In order to study the equivalent width of section coal pillar in rock burst coal seam under water-rich conditions, taking the 4-2 302 working face of a coal mine as an example, stress distribution characteristics and evolution laws of section coal pillars under immersion and natural water content conditions were analyzed by theoretical calculation, numerical simulation and engineering practice. The theoretical calculation results indicate that compared to immersion conditions, the width of the naturally water-bearing coal pillar decreased by 5.66 m, the width of the plastic zone decreased by 2.69 m, and the width of the elastic core zone decreased by 3.53 m. Furthermore, through numerical simulation and comparative analysis of stress peaks and ranges of 36 m immersed coal pillar and 26 m, 28 m, 30 m, 32 m with non-immersed coal pillar, it was found that the stress distribution curves of 30 m non-immersed coal pillar was similar to that of 36 m immersed coal pillar.

The variations in the spectral parameters of the sodium doublet Na I D line of the high-latitude supergiant 89 Her were investigated on the basis of the spectrograms obtained at the 2-m telescope of Shamakhy Astrophysical Observatory for 1975–2017. The research has shown that, in addition to shorter periodic changes, which were found earlier by various authors, there are also long-period changes in the atmosphere of this star. It has been found that the sodium doublet Na I D line's radial velocity of the absorption component varies with a period of 5000 days. The orbital elements of the binary system were determined for the first time within the spectral-binary system model. [ABSTRACT FROM AUTHOR]

A laboratory study of local scour at complex piers under steady clear-water conditions is presented. The term complex piers is used to define a bridge pier comprising of a column, pile cap, and pile group. Comprehensive data over the full range of possible pile cap elevations for complex piers with different geometries were obtained using five complex pier models, which were scaled down from existing bridges in Malaysia. The data are used to evaluate existing methodologies for characterizing the effective width of complex piers with varying pile cap location relative to the undisturbed streambed. The effect of pile cap location on scour depth is also addressed. To improve the predictions of local scour at complex piers, the new data and some previous data are used to propose a new method to predict local scour depth at complex piers. [ABSTRACT FROM AUTHOR]

The latitudinal variations of intensity of the absorption bands of methane on Saturn before and after the equinox in 2009 are considered, when the tilt of the planet's equator to the direction to the Sun was close to zero and both hemispheres were in equal insolation. The basic global changes of meridional distribution of absorption in the weak and moderate bands of methane in the wavelength range of 580-800 nm are extracted. The most characteristic feature of Saturn – a reduced absorption of methane in the equatorial belt – retains.

X-ray photoelectron spectroscopy (XPS) is widely used in surface and materials laboratories around the world. It is a near surface technique, providing detailed chemical information about samples in the form of survey and narrow scans. To extract the maximum amount of information about materials it is often necessary to peak fit XPS narrow scans. And while indispensable to XPS data analysis, even experienced practitioners can struggle with their peak fitting. In our previous publication, we introduced the equivalent width (EW XPS ) as both a possible machine automated method, one that requires less expert judgment for characterizing XPS narrow scans, and as an approach that may be well suited for the analysis of complex spectra. The EW XPS figure of merit was applied to four different data sets. However, as previously noted, other width functions are also regularly employed for analyzing functions. Here we evaluate two other width functions for XPS narrow scan analysis: the autocorrelation width (AW XPS ) and the variance ( σ XPS 2 ). These widths were applied to the same four sets of spectra studied before: (a) four C 1s narrow scans of ozone-treated carbon nanotubes (CNTs) (EW XPS : ∼2.11–2.16 eV, AW XPS : ∼3.9–4.1 eV, σ XPS 2 : ∼5.0–5.2 eV, and a modified form of σ XPS 2 , denoted σ XPS 2 * : ∼6.3–6.8 eV), (b) silicon wafers with different oxide thicknesses (EW XPS : ∼1.5–2.9 eV, AW XPS : ∼2.28–4.9, and σ XPS 2 : ∼0.7–4.9 eV), (iii) hydrogen-terminated silicon surfaces, before and after modification with pentyl groups, and after annealing of the pentyl-terminated surface (EW XPS : ∼0.7–1.0 eV, AW XPS : ∼1.2–1.6 eV, and σ XPS 2 : ∼0.12–0.19 eV), and (iv) C 1s narrow scans from five different nanodiamond samples, three of which showed charging (EW XPS : ∼2.6–4.8 eV, AW XPS : ∼3.8–6.9 eV, and σ XPS 2 : ∼1.6–4.2 eV). All three of the width functions showed similar trends, except in the case of the C 1s spectra of the CNT samples, which were the most complex spectra evaluated, where σ XPS 2 showed poor correlation with the corresponding O/C ratios. Accordingly, we favor EW XPS and AW XPS . EW XPS is advantageous because it is conceptually simple, giving the most intuitive results. AW XPS has the advantage of not requiring the user to specify the height of the function at its maximum, which will be affected by noise. Because these functions are based on different mathematical operations/algorithms, best practices may involve the calculation of both widths for a set of narrow scans. The standard deviation, σ XPS , i.e., the square root of the variance, was also examined. As expected, it gave results similar to σ XPS 2 . [ABSTRACT FROM AUTHOR]

Abstract: We have selected a large sample of star-forming galaxies (104,088) from SDSS-DR4 to derive oxygen abundance calibrations using equivalent width (EW) ratios of three metallicity-sensitive emission-line ratios: [Nii]/Hα, ([Oiii]/Hβ)/([Nii]/Hα), and [Nii]/[Sii]. The analytic calibrations of 12+log(O/H) versus these line-ratios have been obtained as third-order polynomial fits, appropriate for metal-rich galaxies. These observed relations are consistent with photoionization models. These can be used as calibration references for future studies about metallicities of galaxies, especially when there are problems dealing with proper flux calibration for spectra, e.g., some of the current generation of wide-field galaxy surveys that use multi-object spectrographs. [Copyright &y& Elsevier]

High resolution spectra with a high signal/noise ratio have been obtained in the region of the HeI D line for 13 dwarfs of spectral types A5 through K0. The variability in the equivalent width of this spectrum line was studied for five of these stars over a period of several hundred days. Significant variability was observed for only one of these stars, θ Cyg. [ABSTRACT FROM AUTHOR]

The chemically peculiar star HD 115735 (= HR 5023 = 21 CVn) was observed with the 2.34 meter Vainu Bappu Telescope at Kavalur during the period of January 1999 to April 2000. A total of 47 spectrograms were obtained in the wavelength region of 3900 Å to 4400 Å at a resolution of 0.65 Å per pixel. The equivalent widths of Si II features at 4077, 4128, 4131 Å have been found to be varying with a period of 0.88 ± 0.02 day, the amplitudes being about 0.1Å. This is the first report of spectroscopic variations of these features in this star. [ABSTRACT FROM AUTHOR]

A simple reliable theoretical approach is developed to calculate the equivalent width of copper and potassium resonance lines at 3247.54 and 7665 A˚ using atomic absorption techniques. The calculations have been carried out for the two limiting cases of a pure Doppler (Gaussian) and Lorentzian (dispersion) line profiles. The more general case of a Voigt line profile leads to an efficient analytical formula permits a rapid estimate of the equivalent width with sufficient precision. The reliability of the approach has been verified by providing the curves of growth for the given spectral lines to describe the behavior of the equivalent width as the number of absorbing atoms in the ground state is increased. Allowance is made in the analysis for the dependence of the equivalent width for Voigt profile on the damping constant α, which is a measure of the half width of Lorentz profile relative to the Doppler profile. [Copyright &y& Elsevier]

For multimode pulsed dye lasers (of nanosecond and microsecond duration with frequency-dependent losses in the cavity), experimental studies and theoretical calculations have been made of the dependence of the value of the equivalent line width, used as a measure of selective absorption, on the main parameters characterizing the laser, the cavity, and the absorbent. Analytical relations have been obtained which describe the main aspects of complete absorption in lines with dispersion, Gaussian, or mixed spectra profiles, and their experimental testing has been carried out. [ABSTRACT FROM AUTHOR]