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A multistage biometric verification system uses multiple biometrics and/or multiple biometric verifiers to generate a verification decision. The core of a multistage biometric verification system is reject option which allows a stage not to give a genuine/impostor decision when it is not confident enough. This paper studies the effectiveness of symmetric rejection for multistage biometric verification systems. The symmetric rejection method determines the reject region by symmetrically rejecting equal proportion of genuine and impostor scores. The applicability of a multistage biometric verification system depends on how secure and user convenient it is, which is measured by the performance–cost trade-off. This paper analyzes the performance–cost trade-off of symmetric rejection method by conducting extensive experiments. Experiments are performed on two biometric databases: (1) publicly available NIST database and (2) a keystroke database. In addition, the symmetric rejection method is empirically compared with two existing rejection methods: (1) sequential probability ratio test-based method, which uses score-fusion and (2) Marcialis et al.’s method, which does not use score fusion. Results demonstrate strong effect of symmetric rejection method on creating a secure and user convenient multistage biometric verification system.

We collected data of the surface tension versus the temperature of 28 saturated refrigerant fluids available in the NIST database. These data are used to build a new corresponding state-based correlation. Compared with other previously proposed correlations, the current one has the advantages of both simplicity and accuracy. To check the ability of correlations, we compared the numerically calculated/predicted results with the data in the NIST database. It is found that the average absolute deviations are less than 10% for 26 refrigerants and less than 1% for 8 refrigerants.

A very simple method for determining the photoelectron partial intensities and reduced partial intensities for HAXPES photoelectrons is proposed. For these calculations, it is sufficient to know a formalism expressing the photoelectron signal intensity as a function of the inelastic mean free path. The only computational problem is due to required procedure of multiple numerical differentiation, although one can use published programs for that purpose. The proposed method was designed to photoemission emitted by unpolarized X-rays and for planar samples. A wide range of photoelectron energies was considered: from 500 eV to 4000 eV. Evaluation of accuracy was performed by comparison with partial intensities obtained from accompanying Monte Carlo simulations of photoelectron trajectories in the same analytical conditions. The proposed method was found to provide up to eight partial intensities with reasonable accuracy. Depending on element, photoelectron line, and kinetic energy, the mean percentage deviation varied in the range from 0.95% to 3.11%. Similar agreement was observed in comparisons with published partial intensities obtained from Monte Carlo simulations, and with partial intensities obtained from the database SESSA (NIST Database for the Simulation of Electron Spectra for Surface Analysis, Version 2.1.1).

More than 200 toxic substances (including narcotic drugs, psychotropic drugs, organic phosphorus compounds, carbamates, pyrethroids and other pesticides, veterinary drugs, rodenticides, natural toxins, and other drugs) were identified and quantified using an ion-trap mass spectrometer. The advantages of this technique-its selectivity, accuracy, precision, utilization of only small amounts of the sample, and short analysis time for a single sample (less than 30s)-render it a rapid and accurate methodology for toxin screening. Subsequently, an extractive electrospray ionization (EESI) mass spectrometry database was established by combining the Xcalibur data processing system with NIST database software. This allowed unknown toxicants in urine and blood samples, stomach contents, and liver samples, as provided by the Jiangxi Provincial Public Security Department, to be analyzed and identified. This EESI methodology and databank has the potential for widespread application to the large-scale analysis of practical samples. Graphical abstract ᅟ.

International audience; In this work, fully relativistic multi-configuration Dirac-Hartree-Fock approach for calculating atomic structure parameters has been presented and compared to other approaches such as Hartree-Fock pseudo-Relativistic (HFR) method. As an example of application, results of fully relativistic calculations for the ion Ca XV have been obtained and compared to Hartree-Fock pseudo-relativistic calculations and to NIST database values.This example is important for plasma diagnostic and astrophysical studies because Ca XV atomic data of high accuracy are still very scarce.

Laser-induced breakdown spectroscopy (LIBS) is a sensitive optical technique that is capable of rapid multi-elemental analysis. The development of this technique for elemental analysis of pharmaceutical products may eventually revolutionize the field of human health. Under normal circumstances, the elemental analysis of pharmaceutical products based on chemical methods is time-consuming and complicated. In this investigation, the principal aim is to develop an LIBS-based methodology for elemental analysis of pharmaceutical products. This LIBS technique was utilized for qualitative as well as quantitative analysis of the elements present in Ca-based tablets. All the elements present in the tablets were detected and their percentage compositions were verified in a single shot, using the proposed instrument. These elements (e.g., Ca, Mg, Fe, Zn, and others) were identified by the wavelengths of their spectral lines, which were verified using the NIST database. The approximate amount of each element was determined based on their observed peaks and the result was in exact agreement with the content specification. The determination of the composition of prescription drug for patients is highly important in numerous circumstances. For example, the exploitation of LIBS may facilitate elemental decomposition of medicines to determine the accuracy of the stated composition information. Moreover, the approach can provide element-specific, meaningful, and accurate information related to pharmaceutical products. Keywords: Laser-induced breakdown spectroscopy, Elements identification, Health-care pharmaceutics, Qualitative analysis, Quantitative analysis

We show that a variety of the critical parameters of substances can be systematized by relating them to the corresponding Boyle values and heat of vaporization under normal conditions. We have found new relationship for the critical parameters of substances obtained by processing the NIST database and other various sources. According to new relationship, the sum of the ratios of the critical and Boyle temperatures and the critical temperature to the heat of vaporization practically remains constant. The previous one (Apfelbaum and Vorob’ev in J Phys Chem B 113:3521, 2009) states that the sum of the critical temperature and density reduced to the corresponding Boyle values is also constant. Check for 70 substances from the NIST database and calculations for Mie m-6 potential confirmed these regularities within few percent accuracy.

In recent years, LIBS quantitative analysis based on multivariate regression has received considerable attention, and variable selection is critical for improving accuracy of multivariate regression analysis of LIBS. In the present study, sequential backward selection combined with random forest was proposed to improve detection accuracy of sulfur and phosphorus in steel. First, LIBS spectrum line of S and P was identified by the NIST database. Second, input variables for RF calibration model were selected and optimized by SBS, and RF model parameters (ntree and mtry) were optimized by out-of-bag (OOB) estimation. Finally, optimized input variables and model parameters were employed to build an SBS-RF calibration model for quantitative analysis of P and S in steel. Results showed that the SBS-RF model provided good predictions for S (R2 = 0.9991) and P (R2 = 0.9994) compared with those provided by the univariate method, PLS model and traditional RF model. Thus, LIBS coupled with SBS-RF is an effective method for quality supervision and control of steel products.

Many free radical reactions are used currently for syntheses not easily accomplished by other methods. Hence, there is an increasing need for information about bond dissociation energies and enthalpies of formation of the molecules and radicals than is currently available for the more complex species involved in such reactions. We provide 98 standard enthalpies of formation that are not available in the extensive NIST database (number 69), 127 bond dissociation energies not experimentally available, and many previously unknown or uncertain enthalpies of formation of radicals, all at 298 K. A method is presented that allows one to obtain good predictions of the thermodynamic properties of new species using the inherent radical stabilities of their components. The information should be useful for designing and rationalizing synthetic radical reactions.

We present results of measurements of the oscillator strength of intercombination lines of He-like Vanadium ions in high energy density (HED) laser-produced-plasmas and compare them with the simulations from commonly used codes and data from the NIST database. Whilst not yet sufficiently accurate to constrain different trusted atomic-physics models for the particular system studied, our results are in agreement with the available data within experimental error bars, yet differ from cruder approximations of the oscillator strength used in certain atomic-kinetics packages, suggesting that this general method could be further extended to be used as a measurement of the oscillator strength of additional atomic transitions under the extreme conditions that are achieved in HED experiments.

In this study, a Bayesian approach is demonstrated to identify parameters in adsorption isotherm models. First, we demonstrate the data fusion with Bayesian analysis for which we use CO2 sorption on UiO-66 sorbents. This material has been studied by different groups to report CO2 adsorption data in the NIST database under different conditions. We unify the data in two different ways depending upon the assumption around the error distribution of the data. In the first case study, all the data are assumed to have a common error distribution regardless of the source, and in the second approach, the error distributions of data from different sources are distinguished from each other. We apply a Bayesian approach to perform an optimal experimental design to minimize the uncertainty in adsorption isotherm parameters.

The relativistic multiconfiguration Dirac–Hartree–Fock (MCDHF) method has been employed to calculate the atomic parameters of Mo XVIII, which are important for fusion determination of plasma properties in different conditions. Atomic data, such as energy levels, lifetimes, wavelengths, spectroscopic labels, and transition rates for the transitions among the lowest 112 states of the 3 s 2 3 p 6 3 d 7 , 3 s 2 3 p 5 3 d 8 , 3s3 p 6 3 d 8 , and 3s 2 3 p 6 3 d 6 4 s configurations are given. To describe the atomic system accurately, electron correlation effects are taken into account. We also present a calculation within fully relativistic frame based on the Flexible Atomic Code (FAC). This, in turn, allowed us to make an intercomparison on the obtained data. Our two sets of results are also evaluated by comparison with the NIST database recommended values. The new calculated energy levels are, on the average, about 1.5% higher than NIST database recommended values and yield oscillator strengths within 5% of the theoretical values. This study provides a substantial amount of updated atomic data, which are essential for fusion applications.

Synopsis Accurate atomic data of the iron group elements are of major importance in astrophysics. In the present work energy spectrum calculations are performed for 332 lowest states for Ni II ion. Energy levels are compared with NIST database recommended values. All computations were done using the general-purpose relativistic atomic structure package GRASP2018.

Background The use of high-throughput sequencing data has improved the results of genomic analysis due to the resolution of mapping algorithms. Although several tools for copy-number variation calling in whole genome sequencing have been published, the noisy nature of sequencing data is still a limitation for accuracy and concordance among such tools. To assess the performance of PennCNV original algorithm for array data in whole genome sequencing data, we processed mapping (BAM) files to extract coverage, representing log R ratio (LRR) of signal intensity, and B allele frequency (BAF). Results We used high quality sample NA12878 from the recently reported NIST database and created 10 artificial samples with several CNVs spread along all chromosomes. We compared PennCNV-Seq with other tools with general deletions and duplications, as well as for different number of copies and copy-neutral loss-of-heterozygosity (LOH). Conclusion PennCNV-Seq was able to find correct CNVs and can be integrated in existing CNV calling pipelines to report accurately the number of copies in specific genomic regions.

Detecting tattoo images stored in information technology (IT) devices of suspects is an important but challenging task for law enforcement agencies. Recently, the U.S. National Institute of Standards and Technology (NIST) held a challenge and released a tattoo database for the commercial and academic community in advancing research and development into automated image-based tattoo recognition technology. The best tattoo detection result in the NIST challenge was achieved by MorphoTrak with accuracy of 96.3%. This paper aims to answer three questions. 1) Is the NIST database suitable for training algorithms to detect tattoo images stored in IT devices of suspects? 2) Can convolutional neural networks (CNNs) outperform the MorphoTrak's algorithm? 3) How do training databases impact on tattoo detection performance? The NIST tattoo detection database containing 2,349 images and a database containing 10,000 collected from Flickr are utilized to answer these questions. The Flickr images taken in diverse environments and poses are used to simulate images stored in the IT devices. A CNN is trained on the NIST and Flickr images for this study. The experimental results demonstrate that the CNN outperforms the MorphoTrak's algorithm by 2.5%, achieving accuracy of 98.8% on the NIST database. When the CNN is trained on the NIST database to detect Flickr images, the accuracy drops to 65.8%. It implies that the NIST database is not an ideal database for training algorithms to detect tattoo images in IT devices of suspects. However, when the training database size increases, the detection performance improves.

The electronic SURDAT database published in 2007 (available freely from the website www.imim.pl/english ) is being integrated with the NIST database (available freely from www.boulder.nist.gov/div853/lead_free/solders.html ) to provide a single source for data on lead-free (Pb-free) soldering alloys. The NIST database was developed to support circuit board designers, and so it is focused primarily on mechanical properties. In contrast, the SURDAT database is focused primarily on thermophysical properties. Together, they will form a much more complete source for the properties of Pb-free solder alloys.

the literature values. The bath gases (SF6 or CO2) have got minor effect on the rate constants of RHFO2+NO→NO2+prod. reactions; RHFO2 = CH3CH2O2, CH3CHFO2, CH3CF2O2, CF3CH2O2, CF3CHFO2. The obtained rate coefficients are in the scope of the literature values, although they are lower than those recommended in NIST database. The reasons are discussed.

The NIST database lists several Mn II lines that were observed in the laboratory but not classified. They cannot be used in spectrum synthesis because their atomic line data are unknown. These lines are concentrated in the 2380-2700 A interval. We aimed to assign energy levels and log gf values to these lines. Semi-empirical line data for Mn II computed by Kurucz were used to synthesize the ultraviolet spectrum of the slow-rotating, HgMn star HD 175640. The spectrum was compared with the high-resolution spectrum observed with the HST-STIS equipment. A UVES spectrum covering the 3050-10000 A region was also examined. We determined a total of 73 new energy levels, 58 from the STIS spectrum of HD 175640 and another 15 from the UVES spectrum. The new energy levels give rise to numerous new computed lines. We have identified more than 50% of the unclassified lines listed in the NIST database and have changed the assignement of another 24 lines. An abundance analysis of the star HD 175640, based on the comparison of observed and computed ultraviolet spectra in the 1250-3040 A interval, is the by-product of this study on Mn II., Paper accepted by Astronomy & Astrophysics

The article considers the successful implementation of relativistic equation-of-motion coupled cluster method for the electron attachment problem (EA-EOMCC) at the level of single- and double- excitation approximation. The implemented relativistic EA-EOMCC method is employed to calculate ionization potential values of alkali metal atoms (Li, Na, K, Rb, Cs, Fr) and the vertical electron affinity values of LiX (X = H, F, Cl, Br), NaY (Y = H, F, Cl) starting from their closed-shell configuration. Both four-component and exact two-component calculations are done for all the opted systems. Further, we have shown the effect of spin-orbit interaction considering the atomic systems. The results of our atomic calculations are compared with the values from the NIST database and the results are found to be very accurate (< 1 %)., 26 Pages, 3 figures, 6 Tables. Comments are welcome

We carried out a detailed analysis of spectra of the unique roAp star HD 101065 (Przybylski's star) near the resonance doublet Li I 6708 A, using a most complete line list including all possible transitions between REE levels of NIST database. Our model calculations were performed under two assumptions: blend of Li and REE lines, and blend of REE lines only. They prove that Li lines are present in the range 6707.72-6708.02 AA, and that the resulting Li abundance is 3.1 dex (in the scale log N(H) = 12.0, while the isotopic ratio 6Li/7Li is near to 0.3., Comment: 8 pages, 2 figs, 4 tables, accepted by AA

We report the general implementation of the relativistic equation-of-motion coupled-cluster method to calculate double ionization spectra (DI-EOMCC) of atomic and molecular systems. As a first application, this method is employed to calculate the principal valence double ionization potential values of He and alkaline earth metal (Be, Mg, Ca, Sr and Ba) atoms. Our results are compared with the results available from the national institute of standards and technology (NIST) database and other ab initio calculations. We have achieved an accuracy of ~ 0.1%, which is an improvement over the first principles T-matrix calculations [J. Chem. Phys. 123, 144112 (2005)]. We also present results using the second-order many-body perturbation theory and the random- phase approximation in the equation-of-motion framework and these results are compared with the DI-EOMCC results., Comment: 5 pages, 4 figure

Breast density is a widely recognized potential risk factor for breast cancer. However, accurate quantification of breast density is a challenging task in mammography. The current use of plastic breast-equivalent phantoms for calibration provides limited accuracy in dual-energy mammography due to the chemical composition of the phantom. We implemented a breast-equivalent liquid phantom for dual-energy calibration in order to improve the accuracy of breast density measurement. To design these phantoms, three liquid compounds were chosen: water, isopropyl alcohol, and glycerol. Chemical compositions of glandular and adipose tissues, obtained from NIST database, were used as reference materials. Dual-energy signal of the liquid phantom at different breast densities (0% to 100%) and thicknesses (1 to 8cm) were simulated. Glandular and adipose tissue thicknesses were estimated from a higher order polynomial of the signals. Our results indicated that the linear attenuation coefficients of the breast-equivalent liquid phantoms match those of the target material. Comparison between measured and known breast density data shows a linear correlation with a slope close to 1 and a non-zero intercept of 7%, while plastic phantoms showed a slope of 0.6 and a non-zero intercept of 8%. Breast density results derived from the liquid calibration phantoms showed higher accuracy than those derived from the plastic phantoms for different breast thicknesses and various tube voltages. We performed experimental phantom studies using liquid phantoms and then compared the computed breast density with those obtained using a bovine tissue model. The experimental data and the known values were in good correlation with a slope close to 1 (∼1.1). In conclusion, our results indicate that liquid phantoms are a reliable alternative for calibration in dual-energy mammography and better reproduce the chemical properties of the target material. © 2014 Institute of Physics and Engineering in Medicine.

This work reports atomic transition probabilities of 33 spectral lines belonging to 3s-3p, 3p-3d and 3d-4f multiplets of O II, all of them measured in the 405-465 nm spectral region in an emission experiment. Relative intensity measurements have been made on a pulsed discharge lamp and the absolute Aki-values have been obtained taking the NIST database as a reference in temperature diagnosis. The results of this work confirm the other recent available data measured by Veres and Wiese (Veres G and Wiese W L 1996 Phys. Rev. A 54 1999) with a different source and the calculations of Bell et al (Bell K L, Hibbert A, Stafford R P and McLaughlin B M 1994 Phys. Scr. 50 343) with a very satisfactory agreement (usually within 10%).

Developed recently local subspace classifier (LSC) based on local principal component analysis (LPCA) though has high performance (99.4% on NIST database of handwritten digits) lacks a mechanism of recovery from errors. Having confidence levels associated with the decision function in the classifier could help in creation of such procedure. In this paper it is shown how rough set idea can be used to incorporate confidence mechanism. In this way we make the algorithm more adequate to practical use as human actions are now possible at low confidence decisions. Besides main goal of the paper the necessary algorithmic tools for LPCA and their theoretical base are presented, too.

In most vapour-compression refrigeration systems, a certain amount of lubricant oil is used to lubricate moving parts. As a side effect, part of it is carried by the refrigerant and circulates through the entire cycle. In refrigeration systems, lubricant oil cannot be considered alone, because it functions as a refrigerant-oil mixture. In this chapter, the thermodynamic properties of R-134a, Polyalkylene Glycol (PAG) oil and their mixture were investigated.

The lifetime of the 1s 2 2s 2 2p 2P3/2 level as well as the fine structure energy splitting between 2P3/2 and 2P1/2 levels in the boron isoelectronic sequence for low to medium Z elements (Z = 14−36) and for selected high-Z elements (Z = 54, 64, 79, 82, 83, 92) have been calculated using the Dirac-Fock Multiconfiguration method with both quantum-electrodynamic and electronic correlation corrections included. All-order Breit and vacuum polarization corrections were included in the calculation, with a fully optimized active set wavefunction. The results are compared with other theoretical data, NIST database recommended values, and available experimental data. A good agreement with both theoretical and experimental values is obtained.

Three programs were assessed for their ability to predict mass spectral fragmentation patterns for all constitutional isomers of an experimental low-resolution electron impact mass spectrum (EI-MS), given the molecular formula, and use this information to identify the "correct structure". MOLGEN 3.5 was used to generate the structures, while all spectra were extracted from the NIST database. The commercial programs Mass Frontier and ACD MS Manager, as well as MOLGEN-MSF (developed by the University of Bayreuth) were used to generate mass spectral fragments. MOLGEN-MSF was used to generate "match values" to compare the different programs and their ability to identify the "correct structure". Although high match values could be achieved with certain settings, the ranking of the correct structure relative to other constitutional isomers was not significantly better than the results published previously and in some cases significantly worse. Furthermore, all programs showed bias toward specific structures, which changed significantly with minor changes to the program settings. Thus, advances in mass spectral fragment prediction have not necessarily improved computer aided structure elucidation (CASE) from EI-MS and indicate that caution must be used when confirming the identity of a compound only based on the match between its predicted fragments and the mass spectrum.

The PA/p K a equalization principle, that is the idea that H-bond strengths can be rationalized in terms of matching between acid–base properties of the H-bond donor and acceptor moieties, is more than forty years old but has never been verified in its generality for lack of suitable data. Its definitive verification has now become possible, at least in principle, because of the availability of ever more extended compilations of thermodynamic acid–base indicators (proton affinities, PAs, in the gas phase and p K a (H 2 O)s in aqueous solutions) and of two readily accessible and comprehensive sources of H-bond strengths (the NIST database, reporting gas-phase dissociation energies of hundreds of H-bonded complexes, and the Cambridge Structural Database, CSD, including the crystal structures and H-bond geometries of thousands of chemical compounds). The combination of two acid–base indicators (PA and p K a ) with two datasets (gas-phase energies and solid-state geometries) provides four types of possible correlations between H-bond strengths and donor–acceptor acid–base properties, each one potentially leading to the full assessment of the equalization principle for the complete set of known H-bonds. This does not occur in practice and it is shown in the text that a number of constraints of both physical and thermodynamic nature arise which severely limit the application of each type of correlation to partial subsets (classes) of H-bonds and, sometimes, to none. The main practical consequences are that; (i) resonance-assisted H-bonds (RAHBs) cannot be interpreted by means of any acid–base indicator; (ii) gas-phase dissociation enthalpies can be used for the H-bonds which are charged associations of two acids, [A⋯H⋯A′] − , or two bases, [B⋯H⋯B′] + , but not for those which are acid–base associations, A H⋯B, and constitute the class by far most numerous of H-bonds; and (iii) only the correlation between H-bond strengths deriving from crystal geometries and Δp K a s, the p K a differences between H-bond donor and acceptor groups, can deal with these three classes of bonds at the same time and has, therefore, the chance to become the method of election for a quick and reasonably accurate prediction of H-bond strengths based on thermodynamic acid–base indicators.

Introduction Necrotising enterocolitis (NEC) is the most common serious gastrointestinal complication of preterm birth. Clinical signs and symptoms are often non-specific and may only become apparent once disease is established. A biomarker to indicate early disease would allow earlier treatment and may improve outcome. We have reported a pilot study showing changes in faecal volatile organic compounds (VOCs) profile in the prodromal period of NEC. Here, we report a much larger series with more comprehensive clinical and laboratory data. Method Daily faecal samples were collected prospectively from 1375 apparently healthy preterm babies, born between 23 and 34 weeks gestation, in 8 NICUs over a 2-year period. Over 13,000 samples were catalogued. Samples from 70 healthy preterm babies and 34 preterm babies who developed NEC (Bell’s stage II and III) were analysed. In short, 50–100 mg of faeces underwent headspace gas extraction using solid phase micro-extraction followed by gas chromatography–mass spectrometry using our optimised method. Each NEC patient was matched with 1 to 3 healthy control patients. Samples from NEC patients between 1 to 6 days prior to diagnosis and matched samples from controls were selected. Compounds were identified using an in-house developed pipeline involving the AMDIS software, the NIST database and the R packages Metab and XCMS. Univariate and multivariate analysis were performed on the clinical and VOC data. The features best describing the differences between NEC and control samples were used to build a classifier for the diagnosis of NEC. Results Six VOCs and birthweight were significant in multivariable analysis. Birthweight was the strongest predictor. Of the VOCs, 3 were positively associated with NEC and 3 negatively associated. A logistic regression model was developed to diagnose NEC overall, then for each of the 6 days that preceded the clinical diagnosis. Overall the model had an area under the ROC (AUROC) curve of 0.83. When estimated for each day, the AUROC ranged from 0.78 to 0.9. Conclusion To the best of our knowledge, this is the first large scale metabolomics study of faecal VOCs aiming at classifying NEC patients. The data indicate the VOCs may be used to predict NEC up to 6 days before the condition is diagnosed using current methods. This may have an important impact on reducing the mortality of this devastating condition. Further investigation of VOCs may also elucidate the pathogenesis of NEC. Disclosure of interest None Declared.

The success gained by applying bit-plane decomposition methods to handwriting recognition have been demonstrated in our previous work [S. Hoque et al., 2003, 2002]. In this paper we address the relationship between the diversity and the improvements obtained by applying multiple combinations of various layers. These layers are obtained by applying a method based on an n-tuple based classification system, namely, the random decomposition technique proposed in S. Hoque et al. (2003). We investigated 5 combination methods and 9 diversity measures using data extracted from the NIST database. Results presented in this paper support the use of the bit-plane decomposition approach as a diversification method. Strong correlation was found between both the accuracy and the improvements and the diversity measures in the majority of the combination methods investigated.

A comparison is made of the relative accuracy of some NDDO semiempirical methods and the DFT functionals LYP and PW91 using both double and triple zeta basis sets. The comparison is between the calculated heat of formation and that reported in the NIST database.

The ratio of two line strengths at 922.7 nm and 978.7 nm of argon is measured in an argon pulsed discharge with the use of a single-mode Ti:Sapphire laser. The result 3.29(0.13) is in agreement with our theoretical prediction 3.23 and with a less accurate ratio 2.89(0.43) from the NIST database., Comment: 5 pages, 2 figures, 1 table

A summary of the contents and features of the new NIST Atomic Spectra Database is presented. All material in this large database has been obtained from critical data assessments done over the last 30 years. Only reference data, i.e., data fulfilling certain quality requirements, are included. For each spectral line and energy level, one numerical value—the “best” available value—is tabulated.

the Editors of the five journals outlined therationale for the cooperation that ensures authors and reviewersalike are aware of previously published literature for theproperties and systems that are in the NIST database andrelevant to those studied. The process involves NIST“capturing” the new experimental data, comparing it againstexisting values in the NIST data archive, and providing a reportthat (a) lists relevant literature sources and (b) highlights anyobvious discrepancies in the new data. The Journal of Chemical& Engineering Data is primarily concerned with the publicationof original results and in this regard it is incumbent uponauthors to validate their methods by comparison with existingdata.To streamline the process and to further enhance the qualityof published articles, changes have been made to the NISTcooperation that were effective March 2013 and these areoutlined in the following: First, NIST will no longer provide aLiterature Report for each submitted article. In place of thisservice, NIST has created and will maintain the free online toolThermoLit (http://trc.nist.gov/thermolit/) that allows any userto create a Literature Report on demand. This will eliminateNIST’s role in providing the report, thus reducing the timerequired for review. In addition, ThermoLit can be used as aresource by authors and reviewers to, for example, plan anexperimental program. The Journal of Chemical & EngineeringData expects all authors to use ThermoLit to identify relevantliterature data with which to compare their new results.ThermoLit is designed as an aid to the traditional methods usedto obtain a comprehensive literature search and cannot be usedas a substitute for these methods because the NIST data archivedoes not contain data from all journals and publications.NIST will, however, continue to provide data evaluation (theso-called NIST Data Report), at the end of the review process,but immediately prior to final acceptance of the article. Thisevaluation will include comparison of the reported data withvalues within the NIST Data Archive. It will also highlight anyunexpectedly large discrepancies, such as those arising fromtypographical errors. Matters that require further attention fromthe authors will be returned for revision. Although the dataevaluation has not changed, we use this opportunity to remindauthors that results with uncertainties must be tabulated asdescribed in the Guide for Authors, which is obtainable fromhttp://trc.nist.gov/JCED-Support.html, and the links containedtherein. It is mandatory that tables be self-contained andinclude the uncertainties of all reported quantities (variables,constraints, and properties). In addition, authors are required topresent the purity and other details of their samples in tabularform. Example tables and figures have been prepared by NISTand are available (http://trc.nist.gov/JCED-Support.html).Authors need to consult these examples and the presubmissioncheck-list, also available at http://trc.nist.gov/JournalCoop/JCED/Reporting_Guidelines_JCED.html, prior to submissionof their manuscript to ensure that publication is not delayedowing to table format or content problems.In 2012, IUPAC guidelines for the reporting of phaseequilibrium measurements were published (Pure Appl. Chem.2012, 84(8), 1785), and the requirements of this journal areconsistent with those recommendations. We are certain that thenew ThermoLit tool and the procedures described here willfurther enhance the already high quality of articles published inthe Journal of Chemical & Engineering Data. These same revisedinstructions have been published by the other four journalsinvolved in the collaboration with NIST.

In spite of large overabundances of Xe II observed in numerous mercury-manganese (HgMn) stars, Xe II oscillator strengths are only available for a very limited number of transitions. As a consequence, several unidentified lines in the spectra of HgMn stars could be due to Xe II. In addition, some predicted Xe II lines are redshifted by about 0.1 A from stellar unidentified lines, raising the question about the wavelength accuracy of the Xe II line data available in the literature. For these reasons we investigated the Xe II lines lying in the 3900-4521 A, 4769-7542 A, and 7660-8000 A spectral ranges of four well-studied HgMn stars. We compared the Xe II wavelengths listed in the NIST database with the position of the lines observed in the high-resolution UVES spectrum of the xenon-overabundant, slowly rotating HgMn stars HR 6000, and we modified them when needed. We derived astrophysical oscillator strengths for all the Xe II observed lines and compared them with the literature values, when available. In this framework, we performed a complete abundance analysis of HD 71066, while we relied on our previous works for the other stars. We find that all the lines with wavelengths related to the 6d and 7s energy levels have a corresponding unidentified spectral line, blueshifted by the same quantity of about 0.1 A in all the four stars, so that we identified these lines as coming from Xe II and modified their NIST wavelength value according to the observed stellar value. We find that the Xe II stellar oscillator strengths may differ from one star to another from 0.0 dex to 0.3 dex. We adopted the average of the oscillator strengths derived from the four stars as final astrophysical oscillator strength., Paper was accepted by A&A for publication