Swan System Research Articles

The construction of hotel information management mode under the trend of low carbon tourism

Abstract The management of hotels in the context of low-carbon tourism tends to be more and more information-based, and there is an urgent need to build a management model in line with information technology. In this paper, a hotel informatization management system considering customer satisfaction is established, the system objectives are designed based on the demand analysis of travelers, and the functions of subsystems are designed based on the information management activities of the system. For the analysis module of customer satisfaction, the satisfaction index system of hotel travelers is constructed based on the ACSI model, and the satisfaction index is analyzed using the PLSR method. For the database structure of the system, the system tables were divided into several interrelated information tables. In the system test, this system’s read/write rate improved by 8.26% compared with the Green Cloud system and 7.53% compared with the Golden Swan system. Regarding the fit of satisfaction analysis, this system improved by 5.53%, 18.90%, 12.29%, and 1.33% over the quadratic graph method, the Carnot model, the CCSI model, and the ECSI model, respectively. Regarding the optimization rate of services, this system improves by 8.03% compared to the Opera system. The information-based management system helps improve the hotel’s service quality and management level and also provides a solution for operators to develop users in the hotel industry.

Episodes of Molecular Emission in the Optical Spectrum of IRAS 22272+5435

Emission of carbon-bearing molecular lines in multiple optical spectra of IRAS 22272+5435 from 2015 to 2017 is detected, and, for the first time in post–asymptotic giant branch stars, real-time evolution of these features is observed. Specifically, lines of various vibrational transitions of the CN Red system and C2 Swan system are identified to be in emission. Contrary to the narrow and blueshifted AGB ejecta absorption lines, the emission profiles are broad and redshifted or blueshifted by no more than a few kilometers per second. Molecular emissions appear to be exclusive to spectra corresponding to pulsation phases closer to the star’s light maxima than minima, but there are also such spectra without emissions. The time required for emissions to reach the largest observed intensity or decrease to absorption is around 2–3 weeks. The C2 Phillips system lines are observed to have emission components as well, but no evidence for their short-term variability is found. It is proposed that the observed emissions originate within few stellar radii above the photosphere.

Diagnostics of laser-induced plasma on carbon-based polymer material using atomic and molecular emission spectra

Time-integrated optical emission analysis of laser-induced plasma on Teflon is presented. Plasma was induced under atmospheric pressure air using transversely excited atmospheric CO2 laser pulses. Teflon is a C-based polymer that is, among other things, interesting as a substrate for laser-induced breakdown spectroscopy analysis of liquid samples. This study aimed to determine the optimal experimental conditions for obtaining neutral and ionized C spectral lines and C2 and CN molecular band emission suitable for spectrochemical purposes. Evaluation of plasma parameters was done using several spectroscopic techniques. Stark profiles of appropriate C ionic lines were used to determine electron number density. The ratio of the integral intensity of ionic-to-atomic C spectral lines was used to determine the ionization temperature. A spectral emission of C2 Swan and CN violet bands system was used to determine the temperature of the colder, peripheral parts of plasma. We critically analyzed the use of molecular emission bands as a tool for plasma diagnostics and suggested methods for possible improvements.

Vibrational Emission Study of the CN and C2 in Nylon and ZnO/Nylon Polymer Using Laser-Induced Breakdown Spectroscopy (LIBS).

The laser-induced breakdown spectroscopy (LIBS) technique was performed on polymers to study the neutral and ionic emission lines along with the CN violet system (B2Σ+ to X2Σ+) and the C2 Swan system (d3 Пg–a3 Пu). For the laser-based emission analyses, the plasma was produced by focusing the laser beam of a Q-switched Nd: YAG laser (2ω) at an optical wavelength of 532 nm, 5 ns pulse width, and a repetition frequency of 10 Hz. The integration time of the detection system was fixed at 1–10 ms while the target sample was positioned in air ambiance. Two organic polymers were investigated in this work: nylon and nylon doped with ZnO. The molecular optical emission study of nylon and doped nylon polymer sample reveals CN and C2 molecular structures present in the polymer. The vibrational emission analysis of CN and C2 bands gives information about the molecular structure of polymers and dynamics influencing the excitation structures of the molecules. Besides, it was further investigated that the intensity of the molecular optical emission structure strongly depends on the electron number density (cm−3), excitation temperature (eV), and laser irradiance (W/cm2). These results suggest that LIBS is a reliable diagnostic technique for the study of polymers regarding their molecular structure, identification, and compositional analysis.

Laser-Induced Breakdown Spectroscopy analysis of polymers in three different atmospheres

This paper deals with the analysis of polymer materials of various composition and molecular structure using Laser-Induced Breakdown Spectroscopy (LIBS). To make the discussion more transparent, we studied structurally different polymer samples using LIBS in various atmospheres (air, He, Ar) and examined their influence on signal response. We chose aliphatic (PP, PA 66, POM) and aromatic (PS, ABS) polymers with/without heterogeneous atoms (N, O) in their backbone structure. The emission spectra of all examined polymers are exceedingly similar; they exhibit a characteristic atomic/ionic emission line from four biogenic elements (C, H, N, O) and specific molecular emission bands. We focused on intensities of spectral molecular bands such as carbon dimer (C2 Swan system at 516.5 nm) and cyano (CN band at 338.3 nm) bands as a response to various atmospheres. Sources of molecular bands are native bonds and bonds created from an interaction of plasma with buffers gas molecules. Here, we present a correlation between the polymer structure and signal responses. Finally, Principal Component Analysis was used to further assess the influence of ambient atmospheres on the clustering of LIBS data originating from various polymer samples.

Optical emission of graphite plasma generated in ambient air using low-irradiance carbon dioxide laser pulses

Optical emission studies of graphite plasma induced by infrared (IR) Transversely Excited Atmospheric carbon dioxide (TEA CO2) laser pulses in ambient air at atmospheric pressure are reported. The plasma was induced at relatively low-irradiance, up to 40 MW cm−2, and the plasma emission was recorded using time-integrated LIBS measurements. The time profile of the 160 mJ laser pulse is composed of a short, 100 ns long initial spike, and a long 2 μs tail. About 60 mJ is contained in the initial pulse, and the 100-mJ tail contribution is favorable for extended plasma absorption that promotes creation of long-lasting highly-excited plasma. With laser pulse focused behind the target surface, recorded spectra consisted of intensive, sharp atomic and single charged ionic spectral lines of carbon, and trace elements, e.g. Ca, Cu, V, Si, and Ti. Good signal to background ratios obtained indicate potential application in the analysis of impurities in graphite, and also elemental analysis of other materials with high carbon content. The average electron number density was determined from Stark-broadened emission profile of C I 247.9 nm line, and the line intensity ratio of CII 250.9 nm/C I 247.9 nm line pair was used for estimation of ionization temperature. Depending on the applied fluence, electron density was in the range 2.6–4.8 × 1017 cm−3, and ionization temperature between 19,000 and 22,000 K. Beside line spectra, intensive and well-developed band spectra of diatomic molecules C2 (Swan system), and CN (violet system) were obtained. Pulse energy threshold for observation of molecular emission was 50 mJ. From the spectroscopic studies of the emission bands, the rotational and vibrational temperatures were estimated by comparing the experimental and simulated emission spectra. Vibrational and rotational temperatures deduced from Δν = 0 sequences of the Swan system of C2 were 3100 K and 3850 K, respectively. The most intense band of the CN violet system showed strong self-absorption and led to overestimated temperature values, Tvib = Trot = 4900 K.

Tuning of Conversion and Optical Emission by Electron Temperature in Inductively Coupled CO2 Plasma

This paper focuses on how the electron temperature and other plasma properties affect optical emission and CO2 conversion in CO2 plasma. Such plasma-mediated reactions can enable efficient CO2 reuse. We study CO2 and CO plasmas generated by inductively coupled radiofrequency power (30–300 W) at low pressures (6–400 Pa). By varying the argon admixture, we can study the effect of the electron temperature, Te, on the conversion and emission properties using optical emission spectroscopy, mass spectrometry, and electrical probe measurements. Importantly, we can observe several parameters simultaneously: Te, CO2 conversion, chemiluminescence from CO2, and dissociation products and optical emission from several atomic and CO transitions and from the C2 Swan system. On the basis of these results, we establish a correlation between Te, the CO2 conversion, and the optical emission spectra. A low Te enhances CO2 conversion and Swan band emission. In contrast with published studies, our results show that the CO2 and C2 vibrations are not in local equilibrium. This means that the vibrational temperatures of CO2 and C2 should differ.

Nanoparticle synthesis by high-density plasma sustained in liquid organosilicon precursors

A high-density plasma in a pin-to-pin configuration was sustained in liquid organosilicon precursors (hexamethyldisiloxane, tetraethyl orthosilicate, and tetramethylcyclotetrasiloxane) by the application of a high-voltage at a frequency of 1 kHz and a duty cycle of 30%. For all organosilicon precursors investigated, the current-voltage characteristics revealed a spark mode, with typical discharge duration of about 50 ns. Both the number of microdischarges and the total amount of charges per microdischarge increased with the amplitude of the applied voltage. The optical emission spectroscopy revealed strong emission from the C2 Swan system along with H I, Si I, and O I emission lines, indicating very high fragmentation levels of the organosilicon precursors upon discharge ignition. This was confirmed by Transmission Electron Microscopy and Energy-Dispersive X-ray spectroscopy indicating the formation of amorphous silicon oxycarbide nanoparticles. However, W I emission lines as well as W crystalline nanoparticles could also be seen; a feature ascribed to plasma-electrode interactions.

Study of infrared emission spectroscopy for the B(1)Δg-A(1)Πu and B'(1)Σg(+)-A(1)Πu systems of C2.

Thirteen bands for the B(1)Δg-A(1)Πu system and eleven bands for the B'(1)Σg(+)-A(1)Πu system of C2 were identified in the Fourier transform infrared emission spectra of hydrocarbon discharges. The B'(1)Σg(+)v = 4 and the B(1)Δg v = 6, 7, and 8 vibrational levels involved in nine bands were studied for the first time. A direct global analysis with Dunham parameters was carried out satisfactorily for the B(1)Δg-A(1)Πu system except for a small perturbation in the B(1)Δg v = 6 level. The calculated rovibrational term energies up to B(1)Δg v = 12 showed that the level crossing between the B(1)Δg and d(3)Πg states is responsible for many of the prominent perturbations in the Swan system observed previously. Nineteen forbidden transitions of the B(1)Δg-a(3)Πu transition were identified and the off-diagonal spin-orbit interaction constant AdB between d(3)Πg and B(1)Δg was derived as 8.3(1) cm(-1). For the B'(1)Σg(+)-A(1)Πu system, only individual band analyses for each vibrational level in the B'(1)Σg(+) state could be done satisfactorily and Dunham parameters obtained from these effective parameters showed that the anharmonic vibrational constant ωexe is anomalously small (nearly zero). Inspection of the RKR (Rydberg-Klein-Rees) potential curves for the B'(1)Σg(+) and X(1)Σg(+) states revealed that an avoided crossing or nearly avoided crossing may occur around 30,000 cm(-1), which is responsible for the anomalous molecular constants in these two states.

SPECTROSCOPIC VARIABILITY OF IRAS 22272+5435

ABSTRACT A time series of high-resolution spectra was observed in the optical wavelength region for the bright proto-planetary nebula IRAS 22272+5435 (HD 235858), along with a simultaneous monitoring of its radial velocity and BV R C magnitudes. The object is known to vary in light, color, and velocity owing to pulsation with a period of 132 days. The light and color variations are accompanied by significant changes in spectral features, most of which are identified as lines of carbon-bearing molecules. According to the observations, the C2 Swan system and CN Red system lines are stronger near the light minimum. A photospheric spectrum of the central star was calculated using new self-consistent atmospheric models. The observed intensity variations in the C2 Swan system and CN Red system lines were found to be much larger than expected if due solely to the temperature variation in the atmosphere of the pulsating star. In addition, the molecular lines are blueshifted relative to the photospheric velocity. The site of formation of the strong molecular features appears to be a cool outflow triggered by the pulsation. The variability in atomic lines seems to be mostly due variations of the effective temperature during the pulsation cycle. The profiles of strong atomic lines are split, and some of them are variable in a timescale of a week or so, probably because of shock waves in the outer atmosphere.

Time and species dependent ambient air’s effects on carbon clusters generated during femtosecond laser ablation of highly oriented pyrolytic graphite

Near infrared femtosecond laser is employed to ablate highly oriented pyrolytic graphite (HOPG) in ambient air and in vacuum respectively. The recorded transient emission spectra of the ablated plume with a time resolution of 2 ns indicate that the effects of air on the plume are dependent on both time and species. This finding provides important insights into the generation and decay mechanisms of different carbon radicals or clusters. At 1 or 2 ns after the laser pulse strikes the target, air weakens the Swan bands of C2 compared with the case in vacuum, an effect that may be caused by the quenching collisions between air molecules and C2 radicals. This result shows that C2 may be mainly generated by direct spallation from the target surface at the early stage of ablation. Emission spectra at large time delays present that the existence time of the Swan bands in air is longer than the lifetime of the upper electronic state of the Swan system, suggesting that the air-involved three-body recombination and collisional excitation that enhance the generation of emitting C2 overcome quenching collisions at large time delays. A spectral band at ~416 nm assigned to the transition from 1Σ u + to X 1Σ g + of C15 is more intense in air than in vacuum, indicating that C15 clusters are generated at least partially by the combination of smaller clusters in air. It is also found that air-assisted heat transfer makes the temperature of carbon clusters decrease more quickly in air than in vacuum, leading to a much shorter lifetime of the continuum in air.

Laser ablation molecular isotopic spectrometry of carbon isotopes

Quantitative determination of carbon isotopes using Laser Ablation Molecular Isotopic Spectrometry (LAMIS) is described. Optical emission of diatomic molecules CN and C2 is used in these measurements. Two quantification approaches are presented: empirical calibration of spectra using a set of reference standards and numerical fitting of a simulated spectrum to the experimental one. Formation mechanisms of C2 and CN in laser ablation plasma are briefly reviewed to provide insights for implementation of LAMIS measurements. A simulated spectrum of the 12C2 Swan system was synthesized using four constituents within 473.5–476.5nm. Simulation included three branches of 12C2 (1-0), branches R(0-0) and R(1-1), and branch P(9-8) of 12C2. Spectral positions of the tail lines in R(0-0) and R(1-1) were experimentally measured, since they were not accurately known before. The Swan band (1-0) of the isotopologue 13C12C was also simulated. Fitting to the experimental spectrum yielded the ratio 13C/12C=1.08% in a good agreement with measurements by isotope ratio mass spectrometry. LAMIS promises to be useful in coal, oil and shale exploration, carbon sequestration monitoring, and agronomy studies.

Spectroscopic analysis of coal plasma emission produced by laser ablation

An analysis of plasma produced by laser ablation using 1,064 nm of laser radiation from a Q-switched Nd:YAG on coal mineral samples under air ambient, was performed. The emission of molecular band systems such as C2 Swan System , the First Negative System N2 (Band head at 501.53 nm) and different emission lines were investigated using the optical emission spectroscopy technique. The C2 molecular spectra (Swan band) were analyzed to determine vibrational temperature (0.62 eV). The density and electron temperature of the plasma have been evaluated using Stark broadening and the intensity of the nitrogen emission lines (N II). Values of 1.2 eV of electron temperature and 1.82×1019 cm-3 of electron density were found.

Influence of ultrasonic frequency on Swan band sonoluminescence and sonochemical activity in aqueous tert-butyl alcohol solutions.

The multibubble sonoluminescence (MBSL) spectra of t-BuOH aqueous solutions submitted to power ultrasound at 20, 204, 362, and 613 kHz show emissions for the Δυ = -1 to Δυ = +2 vibrational sequences of C2* Swan system (d(3)Πg → a(3)Πu). The Δυ=+2 emission overlaps with the CH(A-X) emission band. The maximal Swan band emission is observed when the MBSL of water itself is almost completely quenched. In general, MBSL is more intense at high-frequency compared to 20 kHz ultrasound. However, in the presence of Xe, the MBSL of C2* at 20 kHz is so bright that it can be seen by the unaided eye as a blue glow in the close vicinity of the ultrasonic tip. The intensity of the C2* band emission exhibits a maximum vs t-BuOH concentration: 0.1-0.2 M at 20 kHz and (1-8) × 10(-3) M at high-frequency ultrasound. Such a huge difference is attributed to a much smaller bubble size at high ultrasonic frequency or, in other words, to a much higher bubble surface/volume ratio providing more efficient saturation of the bubble interior with t-BuOH vapors and to the fact that high frequency bubbles remain active for many more cycles than 20 kHz ones, thus accumulating more hydrocarbon decomposition products. Simulation of the emission spectra using Specair software demonstrated the absence of thermal equilibrium for C2* radicals (Tv > Tr), where Tv and Tr are the vibrational and the rotational temperature, respectively. In Ar, Tv decreases with increasing t-BuOH concentration reaching a steady value in the concentration domain that corresponds to C2* emission maximum intensity. In the presence of Xe an extremely high Tv is obtained, which is explained by the relatively low ionization potential of Xe providing a higher electron temperature of nonequilibrium plasma generated during bubble collapse. Analysis of the gaseous products of t-BuOH sonolysis reveals a significant sonochemical activity even at high t-BuOH concentration when MBSL is totally quenched, indicating that drastic conditions could be produced also within nonsonoluminescing cavitation bubbles.

Excitation spectra of the [formula omitted] band system of C2

Excitation spectra of the d3Πg-c3Σu+ band system of the C2 molecule were observed at room temperature by laser-induced fluorescence spectroscopy. Molecular constants of the c3Σu+ state were determined for the v=0, 1, 2, 3, and 5 levels, including the centrifugal distortion constant. A level crossing between the v=1 level of the c3Σu+ state and the v=7 level of the a3Πu state was unambiguously identified by simultaneously observing the 3–1 band of the d3Πg-c3Σu+ system and the 3–7 band of the Swan system. Rotational level shifts observed in these vibronic levels could be explained by the perturbations arising from the L±S∓ and J±L∓ terms of the spin-orbit and rotational Hamiltonians. De-perturbed molecular constants for the c3Σu+(v=1) and a3Πu(v=7) states are presented, and the possibility of an additional perturbation by another level, A1Πu(v=2), is discussed.

Spectroscopic study of emission coal mineral plasma produced by laser ablation

Spectroscopic analysis of plasma produced by laser ablation of coal samples using 1064 nm radiation pulses from a Q-switched Nd:YAG on different target under air ambient, was performed. The emission of molecular band systems such as C2 Swan System (d3Πg→a3Πu), the First Negative System N2 (Band head at 501,53 nm) and emission lines of the C I, C II, were investigated using the optical emission spectroscopy technique. The C2 molecular spectra (Swan band) were analyzed to determine vibrational temperature (0,62 eV); the density and electron temperature of the plasma have been evaluated using Stark broadening and the intensity of the nitrogen emission lines N II, the found values of 1,2 eV and 2,2 x1018 cm−3 respectively.

C2 Swan spectrum used as a molecular pyrometer in transferred arc and the influence noise to signal ratio on the temperature values

The C2 Swan system molecular emission spectrum is frequently observed in arc plasmas containing hydrocarbons. The spectra emitted from 5 kw in the transferred arc reactor at atmospheric pressure by CH4/CO2/Ar mixture are recorded with the help of an optical system consisting of a linear CCD array coupled with 2m spectrometer. The rotational temperature of 4300±300K is found from the experimental Abel inverted spectra in the arc center after a point-to-point comparison of the spectrum with a computer simulated one. The influence of the noise to signal ratio has been studied, if the noise to signal ratio is about 10% we found an error of 7% at temperature 3000K and 10% at 6000K.

Stark broadening for diagnostics of the electron density in non-equilibrium plasma utilizing isotope hydrogen alpha lines

Two Stark broadening parameters including FWHM (full width at half maximum) and FWHA (full width at half area) of isotope hydrogen alpha lines are simultaneously introduced to determine the electron density of a pulsed vacuum arc jet. To estimate the gas temperature, the rotational temperature of the C2 Swan system is fit to 2500 ± 100 K. A modified Boltzmann-plot method with bi-factor is introduced to determine the modified electron temperature. The comparison between results of atomic and ionic lines indicates the jet is in partial local thermodynamic equilibrium and the electron temperature is close to 13 000 ± 400 K. Based on the computational results of Gig-Card calculation, a simple and precise interpolation algorithm for the discrete-points tables can be constructed to obtain the traditional ne-Te diagnostic maps of two Stark broadening parameters. The results from FWHA formula by the direct use of FWHM = FWHA and these from the diagnostic map are different. It can be attributed to the imprecise FWHA formula form and the deviation between FWHM and FWHA. The variation of the reduced mass pair due to the non-equilibrium effect contributes to the difference of the results derived from two hydrogen isotope alpha lines. Based on the Stark broadening analysis in this work, a corrected method is set up to determine ne of (1.10 ± 0.08) × 1021 m−3, the reference reduced mass μ0 pair of (3.30 ± 0.82 and 1.65 ± 0.41), and the ion kinetic temperature of 7900 ± 1800 K.

Carbon Swan Spectra Measurements following Breakdown of Nitro Compound Explosive Simulants

Our measurements of micro-plasma following laser-induced optical breakdown of nitro compound explosive simulants, here 3-nitrobenzoic acid, show well-developed molecular spectra during the first several hundreds of nanoseconds. Analysis of recorded carbon spectra is accomplished using accurate line strengths for the diatomic molecular Swan system. Presence of hydrogen-beta allows us to infer electron density in the plasma evolution. Computational challenges include accounting for background variation and appropriate modeling of hydrogen embedded in molecular spectra. Recorded and computed spectra agree nicely for time delays on the order of 1.6 μs from optical breakdown when using a single temperature for local thermodynamic equilibrium plasma.

Vibrational emission analysis of the CN molecules in laser-induced breakdown spectroscopy of organic compounds

Laser-induced breakdown spectroscopy (LIBS) of organic materials is based on the analysis of atomic and ionic emission lines and on a few molecular bands, the most important being the CN violet system and the C2 Swan system. This paper is focused in molecular emission of LIBS plasmas based on the CN (B2Σ–X2Σ) band, one of the strongest emissions appearing in all carbon materials when analyzed in air atmosphere. An analysis of this band with sufficient spectral resolution provides a great deal of information on the molecule, which has revealed that valuable information can be obtained from the plume chemistry and dynamics affecting the excitation mechanisms of the molecules. The vibrational emission of this molecular band has been investigated to establish the dependence of this emission on the molecular structure of the materials. The paper shows that excitation/emission phenomena of molecular species observed in the plume depend strongly on the time interval selected and on the irradiance deposited on the sample surface. Precise time resolved LIBS measurements are needed for the observation of distinctive CN emission. For the organic compounds studied, larger differences in the behavior of the vibrational emission occur at early stages after plasma ignition. Since molecular emission is generally more complex than that involving atomic emission, local plasma conditions as well as plume chemistry may induce changes in vibrational emission of molecules. As a consequence, alterations in the distribution of the emissions occur in terms of relative intensities, being sensitive to the molecular structure of every single material.