Quantitative Spectroscopic Analysis Research Articles

Quantitative Spectroscopic Analysis of Surface-Reaching Photoexcited Holes in g-C3N4/TiO2 Z-Scheme Heterojunctions.

The Z-scheme heterojunction has been demonstrated to be effective in tuning the photocatalytic performance of photocatalysts. However, there is still a lack of quantitative and in-depth research on how the Z-scheme heterojunction affects the concentration of surface-reaching photoexcited charges. Here, by combining time-resolved spectroscopies and kinetic analysis, the concentration of surface-reaching photoholes (Ch+(surf)) within g-C3N4/TiO2 Z-scheme heterojunctions was quantitatively analyzed for the first time. Quantitative measurements reveal that Ch+(surf) of the prepared Z-scheme photocatalysts is highly dependent on the g-C3N4 content and the induced Z-scheme heterojunctions at the g-C3N4/TiO2 interface. Encouragingly, we found that a properly engineered Z-scheme heterojunction with close coupling of g-C3N4 and TiO2 can significantly increase the Ch+(surf), leading to nearly a 1.7-fold increase compared with pristine TiO2 samples. Furthermore, a distinct hole trap state-mediated Z-scheme charge transfer mechanism was uncovered in which the intrinsic interface defects at the g-C3N4/TiO2 junction act as hole traps, accelerating interface electron-hole recombination, thereby boosting spatial charge separation and ultimately enriching the Ch+(surf). This work provides insights into understanding and controlling electron pathways and Ch+(surf) in Z-scheme photocatalysis, with implications for the screening of different types of direct Z-scheme photocatalysts.

On-line measurement of COD and nitrate in water against stochastic background interference based on ultraviolet–visible spectroscopy and physics-informed multi-task learning

Traditional ultraviolet–visible spectroscopic quantitative analytical methods face challenges in simultaneous and long-term accurate measurement of chemical oxygen demand (COD) and nitrate due to spectral overlap and the interference from stochastic background caused by turbidity and chromaticity in water. Addressing these limitations, a compact dual optical path spectrum detection sensor is introduced, and a novel ultraviolet–visible spectroscopic quantitative analysis model based on physics-informed multi-task learning (PI-MTL) is designed. Incorporating a physics-informed block, the PI-MTL model integrates pre-existing physical knowledge for enhanced feature extraction specific to each task. A multi-task loss wrapper strategy is also employed, facilitating comprehensive loss evaluation and adaptation to stochastic backgrounds. This novel approach significantly outperforms conventional models in COD and nitrate measurement under stochastic background interference, achieving impressive prediction R2 values of 0.941 for COD and 0.9575 for nitrate, while reducing root mean squared error (RMSE) by 60.89 % for COD and 77.3 % for nitrate in comparison to the conventional chemometric model partial least squares regression (PLSR), and by 30.59 % and 65.96 %, respectively, in comparison to a benchmark convolutional neural network (CNN) model. The promising results emphasize its potential as a spectroscopic instrument designed for online multi-parameter water quality monitoring against stochastic background interference, enabling long-term accurate measurement of COD and nitrate levels.

The IACOB project

Context. Blue supergiants (BSGs) are key objects for understanding the evolution of massive stars, which play a crucial role in the evolution of galaxies. However, discrepancies between theoretical predictions and empirical observations have opened up important questions yet to be answered. Studying statistically significant and unbiased samples of these objects can help to improve the situation. Aims. We perform a homogeneous and comprehensive quantitative spectroscopic analysis of a large sample of Galactic luminous blue stars (a majority of which are BSGs) from the IACOB spectroscopic database, providing crucial parameters to refine and improve theoretical evolutionary models. Methods. We derived the projected rotational velocity (υ sin i) and macroturbulent broadening (υmac) using IACOB-BROAD, which combines Fourier transform and line-profile fitting techniques. We compared high-quality optical spectra with state-of-the-art simulations of massive star atmospheres computed with the FASTWIND code. This comparison allowed us to derive effective temperatures (Teff), surface gravities (log 𝑔), microturbulences (ξ), surface abundances of silicon and helium, and to assess the relevance of stellar winds through a wind-strength parameter (log Q). Results. We provide estimates and associated uncertainties of the above-mentioned quantities for the largest sample of Galactic luminous O9 to B5 stars spectroscopically analyzed to date, comprising 527 targets. We find a clear drop in the relative number of stars at Teff ≈ 21 kK, coinciding with a scarcity of fast rotating stars below that temperature. We speculate that this feature (roughly corresponding to B2 spectral type) might be roughly delineating the location of the empirical terminal-age main sequence in the mass range between 15 and 85 M⊙. By investigating the main characteristics of the υ sin i distribution of O stars and BSGs as a function of Teff, we propose that an efficient mechanism transporting angular momentum from the stellar core to the surface might be operating along the main sequence in the high-mass domain. We find correlations between ξ,υmac and the spectroscopic luminosity 𝓛 (defined as Teff4 / g). We also find that no more than 20% of the stars in our sample have atmospheres clearly enriched in helium, and suggest that the origin of this specific subsample might be in binary evolution. We do not find clear empirical evidence of an increase in the wind strength over the wind bi-stability region toward lower Teff.

Improved and Validated Quantitative Spectroscopic Analysis of Chlorpheniramine in Pharmaceutical Formulations

Improved and Validated Quantitative Spectroscopic Analysis of Chlorpheniramine in Pharmaceutical Formulations

The unusual planetary nebula nucleus in the Galactic open cluster M37 and six further hot white dwarf candidates

Planetary nebulae in Galactic open star clusters are rare objects; only three are known to date. They are of particular interest because their distance can be determined with high accuracy, allowing one to characterize the physical properties of the planetary nebula and its ionizing central star with high confidence. Here we present the first quantitative spectroscopic analysis of a central star in an open cluster, namely the faint nucleus of IPHASX J055226.2+323724 in M37. This cluster contains 14 confirmed white dwarf members, which were previously used to study the initial-to-final-mass relation of white dwarfs, and six additional white dwarf candidates. We performed an atmosphere modeling of spectra taken with the 10m Gran Telescopio Canarias. The central star is a hot hydrogen-deficient white dwarf with an effective temperature of 90 000 K and spectral type PG1159 (helium- and carbon-rich). We know it is about to transform into a helium-rich DO white dwarf because the relatively low atmospheric carbon abundance indicates ongoing gravitational settling of heavy elements. The star belongs to a group of hot white dwarfs that exhibit ultrahigh-excitation spectral lines possibly emerging from shock-heated material in a magnetosphere. We find a relatively high stellar mass of M = 0.85−0.14+0.13 M⊙. This young white dwarf is important for the semi-empirical initial-final mass relation because any uncertainty related to white-dwarf cooling theory is insignificant with respect to the pre-white-dwarf timescale. Its post-asymptotic-giant-branch age of 170 000–480 000 yr suggests that the extended planetary nebula is extraordinarily old. We also performed a spectroscopic analysis of the six other white dwarf candidates of M37, confirming one as a cluster member.

Non-targeted and targeted analytical approaches for estimating the features of wine spirits

Non-targeted UV–Vis/synchronous fluorescence (SF) spectroscopic and differential pulse voltammetric (DPV) fingerprinting have been tested to discriminate between caramel-containing and caramel-free wine spirits using partial least squares-discriminant analysis (PLS-DA), variable importance in projection (VIP)-PLS-DA, VIP-principal component analysis-linear discriminant analysis (PCA-LDA) and VIP-support vector machine (SVM). A 96 % total correct classification in VIP-PLS-DA and VIP-PCA-LDA was achieved using, among others, of 115 variables corresponding to a potential range from 0.43 to 1.00 V in DPV, or 45 variables selected from SF spectra recorded at a difference between the emission and excitation wavelengths of 100 nm for diluted samples. The conclusions resulting from the non-targeted methods were verified and confirmed by the targeted quantitative analysis of the samples using the HPLC-DAD method, focused on 5-hydroxymethylfurfural, furfural, syringaldehyde and vanilline. In targeted SF spectroscopic quantitative analysis, the PLS regression model based on 21 variables selected from SF spectra recorded at a difference between the emission and excitation wavelengths of 100 nm was suitable for the determination of caramel in the range from 0.1 to 4.0 g/L. High coefficients of determination R2 and small root mean squared error (RMSE) values for both cross-validation and prediction (R2 = 0.9811 and 0.9736, respectively, and RMSE = 0.046 and 0.047, respectively) prove good quantitative properties of the VIP-PLS regression model.

In-situ redox conditions in hydrothermal diamond-anvil cell experiments using various metal gaskets

Hydrothermal diamond-anvil cells (HDACs) have been widely used in various research fields since they were introduced in 1993. Unlike temperature (T) and pressure (P), the redox states of the samples in HDAC experiments were poorly controlled or measured; they were usually estimated by observing the reduction/disappearance of redox-sensitive mineral(s) (e.g., Mo metal) and corresponding formation and growth of such mineral(s) (e.g., MoO2) without in-situ redox measurement. In this study, we demonstrated the generation of H2 during experiments using various metal gaskets, including inert (Re) and chemically more reactive metals (Ni, Co, Mo, and W), in the pure H2O system under various P-T conditions. A technique for quantitative Raman spectroscopic analysis of H2 in HDAC is designed. Based on this technique, the oxygen fugacity (fO2) values of Mo-MoO2 buffer at the experimental P-T conditions were then calculated from these measured H2 pressures. We demonstrated that steady-state redox control can be maintained at a fixed T between 400 and 500 °C in HDAC experiments using a Mo gasket for durations of up to two hours and for those using a Re gasket with an additional Mo rod in the sample between 400 and 800 °C for durations of up to 90 min, regardless of the considerable changes in sample pressure. This demonstration was established by the balance between the rates of H2 generation and H2 loss from the sample chamber. The loss of H2 enhanced the consumption of H2O and therefore reduced the sample pressures during the experiments.We believe that hydrogen contents in every HDAC experiment, which attempt to control the redox state, need in situ measurement, then estimate the real redox state and compare it to thermodynamic equilibrium prediction. To enhance in situ redox control and measurements, modifications of HDAC are required for improving the quantitative Raman spectroscopic analysis technique in both sensitivity and accuracy.

Electrospun Poly-L-Lactic Acid Scaffolds Surface-Modified via Reactive Magnetron Sputtering Using Different Mixing Ratios of Nitrogen and Xenon.

Controlled regeneration processes involving tissue growth using the surface and structure of scaffolds, are actively used in tissue engineering. Reactive magnetron sputtering is a versatile surface modification method of both metal and polymer substrates, as the properties of the formed coatings can be modified in a wide range by changing the process parameters. In magnetron sputtering, the working gas and its composition have an influence on the chemical composition and physical characteristics of the obtained coatings. However, there are no studies addressing the influence of the nitrogen/xenon gas mixture ratio in direct current magnetron sputtering on the deposition rate, physicochemical and in vitro properties of surface-modified biocompatible poly-L-lactic acid scaffolds. In this study, the application of mixtures of nitrogen and xenon in various ratios is demonstrated to modify the surface of non-woven poly-L-lactic acid scaffolds by direct current magnetron sputtering of a titanium target. It has been found that the magnetron sputtering parameters chosen do not negatively influence the morphology of the prepared scaffolds, but increase the hydrophilicity. Moreover, quantitative spectroscopic analysis results indicate that the formed coatings are primarily composed of titanium oxide and titanium oxynitride compounds and is dependent on the gas mixture ratio only to a certain extent. Atomic force microscopy investigations of the roughness of the fibers of the electrospun scaffolds and the thickness of the coatings formed on them show that the considerable variations observed in the intrinsic fiber reliefs are due to the formation of a fine layer on the fiber surfaces. The observed decrease in roughness after plasma modification is due to temperature and radiation effects of the plasma. In vitro experiments with human osteosarcoma cells show that the scaffolds investigated here have no cytotoxic effect on these cells. The cells adhere and proliferate well on each of the surface-modified electrospun scaffolds, with stimulation of cell differentiation in the osteogenic direction.

Radiation-Driven Wind Hydrodynamics of Massive Stars: A Review

Mass loss from massive stars plays a determining role in their evolution through the upper Hertzsprung–Russell diagram. The hydrodynamic theory that describes their steady-state winds is the line-driven wind theory (m-CAK). From this theory, the mass loss rate and the velocity profile of the wind can be derived, and estimating these properly will have a profound impact on quantitative spectroscopy analyses from the spectra of these objects. Currently, the so-called β law, which is an approximation for the fast solution, is widely used instead of m-CAK hydrodynamics, and when the derived value is β≳1.2, there is no hydrodynamic justification for these values. This review focuses on (1) a detailed topological analysis of the equation of motion (EoM), (2) solving the EoM numerically for all three different (fast and two slow) wind solutions, (3) deriving analytical approximations for the velocity profile via the LambertW function and (4) presenting a discussion of the applicability of the slow solutions.

Improving the accuracy of quantitative spectroscopic analysis of leukocyte by suppressing the influence of the "M" factors based on "M + N" theory.

Leukocytes play a crucial role in clinical diagnosis. The noninvasive and immediate detection of this low blood component has both important application and academic significance. The "M + N" theory makes it obvious that suppressing the influence of N factors and reducing the influence of M factors are both necessary in order to accurately detect the low content of blood components like leukocytes. Therefore, based on the strategy of "fixing the influencing factors" in the "M + N" theory, this paper proposes the method of "partition modeling based on the content of large concentrations of non-target components." Firstly, a dynamic spectral acquisition system was built to achieve the noninvasive acquisition of spectra. Then this paper applies the method proposed above to the modeling process of the samples. In order to lessen the impact of the M factors, the approach first divides the samples into groups based on the concentrations of the major blood components (platelets and hemoglobin). This reduces the range of fluctuation of the non-target components in each interval. The modeling of the leukocyte content was then carried out independently for each sample contained in each compartment. Compared with the result of modeling the sample directly, the related coefficient of the calibration set (Rc) improved by 11.70%, and the root mean square error (RMSEC) decreased by 76.97%; the related coefficient of the prediction set (Rp) improved by 32.68%, and the root mean square error (RMSEP) decreased by 52.80%. When the model was applied to predict all samples, the related coefficient (R-all) increased by 16.67%, and the root mean square error (RMSE-all) dropped by 63.00%. It was shown that, as compared to direct modeling of leukocyte concentration, the method of "partition modeling based on the content of large concentrations of non-target components" considerably increased the accuracy of quantitative analysis of leukocytes. The method can be used to analyze other blood components as well, offering a fresh approach and technique to increase the precision of spectral analysis of the blood's small content components.

High-sensitivity IR to UV broadband ellipsometry and transmission characterization of high-purity glasses

Glasses are widely used as transparent substrates in thin-film and optical applications, but also as window materials in devices and operando cells. Determining the dielectric properties of the glass over a wide spectral range is often the crucial first step for the subsequent quantitative spectroscopic analysis, design and application of layer stacks and complex sample systems. Reflection-based ellipsometry—the method of choice for this task—is challenging for thick transparent substrates because of backside reflections that influence the optical response. Here, we extend the methodological treatment of backside reflections in ellipsometry by accounting for the spatial overlap—and its dependence on incidence angle, thickness and refractive index—between the light beams’ cross-sections and the detector aperture. We thereby demonstrate the incorporation of backside reflections in high-sensitivity multi-instrument, multi-angle ellipsometry and transmission for both measurement and quantitative modeling of glasses. Consolidating data from three instruments, we determine the dielectric function of two high-purity fused silica (Suprasil1) and quartz (Herasil102) glasses from the deep-ultraviolet to the mid-infrared (200–25000nm), with a sensitivity to absorption features as small as 10–7. Our non-destructive approach obviates the need for sample modifications like backside roughening, thus laying the foundation for future detailed ellipsometry studies on lower-purity glasses such as soda–lime- and borosilicate-based substrates for thin-film applications.

Spectroscopic investigations of detachment on the MAST Upgrade Super-X divertor

We present the first analysis of the atomic and molecular processes at play during detachment in the MAST-U Super-X divertor using divertor spectroscopy data. Our analysis indicates detachment in the MAST-U Super-X divertor can be separated into four sequential phases: first, the ionisation region detaches from the target at detachment onset leaving a region of increased molecular densities downstream. The plasma interacts with these molecules, resulting in molecular ions ( and/or ) that further react with the plasma leading to molecular activated recombination and dissociation (MAR and MAD), which results in excited atoms and significant Balmer line emission. Second, the MAR region detaches from the target leaving a sub-eV temperature region downstream. Third, an onset of strong emission from electron–ion recombination (EIR) ensues. Finally, the electron density decays near the target, resulting in the bulk of the electron density moving upstream. The analysis in this paper indicates that plasma–molecule interactions have a larger impact than previously reported and play a critical role in the intensity and interpretation of hydrogen atomic line emission characteristics on MAST-U. Furthermore, we find that the Fulcher band emission profile in the divertor can be used as a proxy for the ionisation region and may also be employed as a plasma temperature diagnostic for improving the separation of hydrogenic emission arising from electron-impact excitation and that from plasma–molecular interactions. We provide evidences for the presence of low electron temperatures (≪0.5 eV) during detachment phases III–IV based on quantitative spectroscopy analysis, a Boltzmann relation of the high-n Balmer line transitions together with an analysis of the brightness of high-n Balmer lines.

Exploring variables optimization methods to screen surface-enhanced Raman spectroscopy characteristic peaks for rapid detection of difenoconazole pesticides in tea

Detection of pesticide residues in tea is a requisite technique to safeguard consumer food safety. This paper carried out rapid quantitative analysis of difenoconazole residues by surface-enhanced Raman spectroscopy (SERS) combined with chemometric methods. Primary secondary amine (PSA), nano bamboo charcoal (NBC) and anhydrous MgSO4 were employed to eliminate the impact of tea matrix in tea on the difenoconazole pesticides investigation. SERS spectral data excited with gold colloid was collected from 97 tea samples. Competitive adaptive reweighted sampling (CARS) was employed to choose some optimal spectral variables, which were coincident with experiment characteristic peaks and theoretical calculation. Then, random forest (RF) was adapted to develop quantitative analysis models for monitoring difenoconazole residues, and compared with partial least squares (PLS) models. The results demonstrated that the prediction performance of the models using spectra variables subset screened by CARS was significantly improved. In addition, non-linear RF regression models outperformed linear PLS regression models in predicting difenoconazole concentration in tea. The best results of the CARS_RF model were obtained with correlation coefficient (R), root mean square error (RMSE) and ratio performance deviation (RPD) in prediction set of 0.97, 2.50 and 4.01, respectively. The overall results encouraged the development of a rapid, simple and convenient spectral spectroscopic quantitative analysis method of pesticide residues in tea.

Quantitative calorimetric and spectroscopic analysis of drug-drug interactions

Quantitative study of drug-drug interaction (DDI) is important for their effective and safe clinical management of various diseases. The interaction between two drugs results in either a reduction in action of one drug or an overall enhancement of the patient-beneficial effect. In the present work, we have studied interaction of naproxen with various anticancer, non-steroidal anti-inflammatory drugs, vitamins, antibiotic, antidiabetic, and antithyroid drugs with the help of ultrasensitive isothermal titration calorimetry and uv-absorbance spectroscopy. The purpose of this research is to comprehend the strength of drug-drug interaction based on thermodynamic signatures and simultaneously obtain support from absorbance spectral changes. Weak interaction of naproxen was observed with all the studied drugs except for L-ascorbic acid, diclofenac and lincomycin. In all the discussed drugs L-Ascorbic acid has the strongest interaction with naproxen while diclofenac and lincomycin show no sign of interaction. Further, correlation of standard molar enthalpy of interaction (ΔHm°), change in absorbance maxima (ΔAmax), and partitioning coefficient in organic to aqueous phase (logP) with number of H-bonding groups present (nH) on the drug was done, which suggests that with increase in hydrogen bonding groups the strength of DDI decreases. The thermodynamic signature also enabled understanding role of desolvation in the interaction process.

The IACOB project

Context. Stellar rotation is of key importance in the formation process, the evolution, and the final fate of massive stars. Aims. We perform a reassessment of the empirical rotational properties of Galactic massive O-type stars using the results from a detailed analysis of ground-based multi-epoch optical spectra obtained in the framework of the IACOB & OWN surveys. Methods. Using high-quality optical spectroscopy, we established the velocity distribution for a sample of 285 apparently single and single-line spectroscopic binary (SB1) Galactic O-type stars. We also made use of the rest of the parameters from the quantitative spectroscopic analysis presented in prior IACOB papers (mainly Teff, log g, and multiplicity) to study the v sin i behavior and evolution from the comparison of subsamples in different regions of the spectroscopic Hertzsprung–Rusell diagram (sHRD). Our results are compared to the main predictions – regarding current and initial rotational velocities – of two sets of well-established evolutionary models for single stars, as well as from population synthesis simulations of massive stars that include binary interaction. Results. We reassess the known bimodal nature of the v sin i distribution, and find a non-negligible difference between the v sin i distribution of single and SB1 stars. We provide empirical evidence supporting the proposed scenario that the tail of fast rotators is mainly produced by binary interactions. Stars with extreme rotation (>300 km s−1) appear as single stars that are located in the lower zone of the sHRD. We notice little rotational braking during the main sequence, a braking effect independent of mass (and wind strength). The rotation rates of the youngest observed stars lean to an empirical initial velocity distribution with ⪅20% of critical velocity. Lastly, a limit in v sin i detection below 40–50 km s−1 seems to persist, especially in the upper part of the sHRD, possibly associated with the effect of microturbulence in the measurement methodology used.

Completely Computational Model Setup for Spectroscopic Techniques: The Ab Initio Molecular Dynamics Indirect Hard Modeling Approach.

The spectroscopic quantification of mixture compositions usually requires pure compounds and mixtures of known compositions for calibration. Since they are not always available, methods to fill such gaps have evolved, which are, however, not generally applicable. Therefore, calibration can be extremely challenging, especially when multiple unstable species, for example, intermediates, exist in a system. This study presents a new calibration approach that uses ab initio molecular dynamics (AIMD)-simulated spectra to set up and calibrate models for the physics-based spectral analysis method indirect hard modeling (IHM). To demonstrate our approach called AIMD-IHM, we analyze Raman spectra of ternary hydrogen-bonding mixtures of acetone, methanol, and ethanol. The derived AIMD-IHM pure-component models and calibration coefficients are in good agreement with conventionally generated experimental results. The method yields compositions with prediction errors of less than 5% without any experimental calibration input. Our approach can be extended, in principle, to infrared and NMR spectroscopy and allows for the analysis of systems that were hitherto inaccessible to quantitative spectroscopic analysis.

Quantitative Spectroscopic Analysis of Water Populations in the Hydrated Nanopore Environments of a Natural Montmorillonite

Smectite clays are implicated in solute trapping in natural and engineered processes. Here we evaluated 23Na solid-state nuclear magnetic resonance (NMR) and thermogravimetric analysis-coupled mass...

Fundamental parameters of the massive eclipsing binary HM1 8

ABSTRACT We present a comprehensive study of the massive binary system HM1 8, based on multi-epoch high-resolution spectroscopy, V-band photometry, and archival X-ray data. Spectra from the OWN Survey, a high-resolution optical monitoring of Southern O and WN stars, are used to analyse the spectral morphology and perform quantitative spectroscopic analysis of both stellar components. The primary and secondary components are classified as O4.5 IV(f) and O9.7 V, respectively. From a radial velocity (RV) study, we derived a set of orbital parameters for the system. We found an eccentric orbit (e = 0.14 ± 0.01) with a period of P = 5.87820 ± 0.00008 d. Through the simultaneous analysis of the RVs and the V-band light curve, we derived an orbital inclination of 70.0° ± 2.0 and stellar masses of $M_a=33.6^{+1.4}_{-1.2}~\text{M}_{\odot }$ for the primary, and $M_b=17.7^{+0.5}_{-0.7}~\text{M}_{\odot }$ for the secondary. The components show projected rotational velocities vasin i = 105 ± 14 km s−1 and vbsin i = 82 ± 15 km s−1, respectively. A tidal evolution analysis is also performed and found to be in agreement with the orbital characteristics. Finally, the available X-ray observations show no evidence of a colliding winds region; therefore, the X-ray emission is attributed to stellar winds.

Ethanol inactivation of orthonairoviruses in ixodid ticks

Ixodid ticks represent vectors and reservoirs for a broad range of zoonotic pathogens. Collected ticks from field studies are therefore usually stored in ethanol, which in higher concentrations effectively inactivates most of the known tick-borne pathogens. Although commonly practiced as gold standard for inactivation, hardly any scientific data demonstrate that ethanol sufficiently penetrates the comparatively thick cuticula of ticks. Therefore, Amblyomma hebraeum tick pools were stored for 21 days in ethanol (96%). Afterwards, the ethanol was removed and the ticks were homogenized. Quantitative 1H-NMR spectroscopic analysis was applied to determine the residual concentration of ethanol inside the ticks. 1H-NMR spectroscopic analysis revealed that ethanol constituted 28.3–42.6 mg of the total weight of three ticks in the pools (89.9–121.5 mg). In addition, the low-pathogenic Hazara orthonairovirus (HAZV) was used as a cell culture model for this study. The virus was exposed to ethanol concentrations between 0 and 60% and incubated under various temperature conditions for four time periods. Afterwards, the residual virus infectivity was determined by titration. Following ethanol exposure, HAZV did not grow in cells after 9 h of exposure to an ethanol concentration of 25%. These results demonstrate an extremely low ethanol resistance of the virus, which was generally in line with previously reported ethanol inactivation data for Crimean-Congo hemorrhagic fever orthonairovirus (CCHFV). After prolonged storage and impregnation, comparable ethanol concentrations are achieved in the ticks, indicating the suitability of this inactivation method also for Bunyaviruses in ticks. At the very least, a massive virus inactivation can be assumed. Definitive proof of virus inactivation would require a bioassay of ethanol-treated infected ticks under appropriate biosafety conditions.

ISOSCELES: Grid of stellar atmosphere and hydrodynamic models of massive stars. The first results

AbstractIn this work we seek to derive simultaneously the stellar and wind parameters of massive stars, mainly A and B type supergiant stars. Our stellar properties encompass the effective temperature, the surface gravity, the micro-turbulence velocity and, silicon abundance. For wind properties we consider the line–force parameters (α, k and δ) obtained from the standard line-driven wind theory. To model the data we use the radiative transport code Fastwind considering the hydrodynamic solutions derived with the stationary code Hydwind. Then, ISOSCELES, a grid of stellar atmosphere and hydrodynamic models of massive stars is created. Together with the observed spectra and a semi-automatic tool the physical properties from these stars are determined through spectral line fittings. This quantitative spectroscopic analysis provide an estimation about the line–force parameters. In addition, we confirm that the hydrodynamic solutions, called δ-slow solutions, describe quite reliable the radiation line-driven winds of B supergiant stars.