Data Evaluation Procedures Research Articles

IUPAC recommended experimental methods and data evaluation procedures for the determination of radical copolymerization reactivity ratios from composition data

The IUPAC method uses monomer composition, conversion, and copolymer composition to find reactivity ratios. Shown the optimal reactivity ratios in red and a 95% Confidence Interval in blue.

A novel and holistic approach for experimental x-ray fundamental parameter determination—the Ru L-shell

The present work aims to improve both the experimental and the data evaluation procedures necessary for a determination of L-subshell atomic fundamental parameters (FPs). The main motivation lies in the fact that the established approach, consisting of a sequential evaluation of recorded transmission and fluorescence spectra in the vicinity of the three L-absorption edges, provides relatively large uncertainties for the Coster–Kronig (CK) factors. Up to now, reliable uncertainty budgets were in the order of 15%–100% and more. The novel holistic evaluation procedure addresses these large uncertainties, by employing a much larger experimental dataset extending far above the L1 absorption edge and a combined evaluation approach for a more reliable determination of the CK factors. Here, using the Ru-L shells as an example, their uncertainties are reduced to under 15%. In addition, this enables also the determination of other relevant FP data, such as the L-subshell Auger yields, the L-subshell photoionization cross sections as well as the L-subshell fluorescence production cross sections with significantly lower uncertainties as compared to the established approach.

Near-edge X-ray absorption fine structure spectroscopy in studies of self-assembled monomolecular films

This article reviews the application of near-edge X-ray absorption fine structure (NEXAFS) spectroscopy to characterization of self-assembled monolayers (SAMs) which are an important part of modern nanotechnology, being particular useful in context of surface and interface engineering. NEXAFS spectroscopy provides information about the electronic structure of the SAMs, which allows to recognize specific functional groups and building blocks of the SAM-forming molecules. Due to the linear dichroism effects in X-ray absorption, this technique is also capable to give insight into orientational order and molecular orientation in the SAMs, both overall and building-block-specific. To illustrate the above points, a variety of representative examples for different classes of SAMs is provided, accompanied by the information about the general aspects of the technique and the description of suitable data evaluation procedures. Finally, it is shown that the application of NEXAFS spectroscopy to SAMs is not only limited by their characterization but is also useful to monitor chemical and physical processes involving these systems.

Fick diffusion coefficients probed by the shadowgraph method considering confinement and advection.

The present work contributes to the development of the shadowgraph method for its routine application for an accurate determination of the Fick diffusion coefficient D11 of binary fluid mixtures. In this context, measurement and data evaluation strategies for thermodiffusion experiments where confinement and advection are potentially present are elaborated by studying two binary liquid mixtures with positive and negative Soret coefficients, i.e., 1,2,3,4-tetrahydronaphthalene/n-dodecane and acetone/cyclohexane. For obtaining accurate D11 data, the dynamics of non-equilibrium fluctuations in concentration is analyzed considering recent theory by data evaluation procedures that are demonstrated to be suitable for different experimental configurations.

Nanomaterial Characterization in Complex Media-Guidance and Application.

A broad range of inorganic nanoparticles (NPs) and their dissolved ions possess a possible toxicological risk for human health and the environment. Reliable and robust measurements of dissolution effects may be influenced by the sample matrix, which challenges the analytical method of choice. In this study, CuO NPs were investigated in several dissolution experiments. Two analytical techniques (dynamic light scattering (DLS) and inductively-coupled plasma mass spectrometry (ICP-MS)) were used to characterize NPs (size distribution curves) time-dependently in different complex matrices (e.g., artificial lung lining fluids and cell culture media). The advantages and challenges of each analytical approach are evaluated and discussed. Additionally, a direct-injection single particle (DI sp)ICP-MS technique for assessing the size distribution curve of the dissolved particles was developed and evaluated. The DI technique provides a sensitive response even at low concentrations without any dilution of the complex sample matrix. These experiments were further enhanced with an automated data evaluation procedure to objectively distinguish between ionic and NP events. With this approach, a fast and reproducible determination of inorganic NPs and ionic backgrounds can be achieved. This study can serve as guidance when choosing the optimal analytical method for NP characterization and for the determination of the origin of an adverse effect in NP toxicity.

Ice nucleating properties of the sea ice diatom Fragilariopsis cylindrus and its exudates

Abstract. In this study, we investigated the ice nucleation activity of the Antarctic sea ice diatom Fragilariopsis cylindrus. Diatoms are the main primary producers of organic carbon in the Southern Ocean, and the Antarctic sea ice diatom F. cylindrus is one of the predominant species. This psychrophilic diatom is abundant in open waters and within sea ice. It has developed several mechanisms to cope with the extreme conditions of its environment, for example, the production of ice-binding proteins (IBPs) and extracellular polymeric substances known to alter the structure of ice. Here, we investigated the ice nucleation activity of F. cylindrus using a microfluidic device containing individual sub-nanolitre (∼90 µm) droplet samples. The experimental method and a newly implemented Poisson-statistics-based data evaluation procedure applicable to samples with low ice nucleating particle concentrations were validated by comparative ice nucleation experiments with well-investigated bacterial samples from Pseudomonas syringae (Snomax®). The experiments reveal an increase of up to 7.2 ∘C in the ice nucleation temperatures for seawater containing F. cylindrus diatoms when compared to pure seawater. Moreover, F. cylindrus fragments also show ice nucleation activity, while experiments with the F. cylindrus ice-binding protein (fcIBP) show no significant ice nucleation activity. A comparison with experimental results from other diatoms suggests a universal behaviour of polar sea ice diatoms, and we provide a diatom-mass-based parameterization of their ice nucleation activity for use in models.

The impact of biostatistics on hazard characterization using in vitro developmental neurotoxicity assays.

In chemical safety assessment, benchmark concentrations (BMC) and their associated uncertainty are needed for the toxicological evaluation of in vitro data sets. A BMC estimation is derived from concentration-response modelling and results from various statistical decisions, which depend on factors such as experimental design and assay endpoint features. In current data practice, the experimenter is often responsible for the data analysis and therefore relies on statistical software, often without being aware of the software default settings and how they can impact the outputs of data analysis. To provide more insight into how statistical decision-making can influence the outcomes of data analysis and interpretation, we have developed an automated platform that includes statistical methods for BMC estimation, a novel endpoint-specific hazard classification system, and routines that flag data sets that are outside the applicability domain for an automatic data evaluation. We used case studies on a large dataset produced by a developmental neurotoxicity (DNT) in vitro battery (DNT IVB). Here we focused on the BMC and its confidence interval (CI) estimation as well as on final hazard classification. We identified five crucial statistical decisions the experimenter must make during data analysis: choice of replicate averaging, response data normalization, regression modelling, BMC and CI estimation, and choice of benchmark response levels. The insights gained are intended to raise more awareness among experimenters on the importance of statistical decisions and methods but also to demonstrate how important fit-for-purpose, internationally harmonized and accepted data evaluation and analysis procedures are for objective hazard classification.

Reference Density Database for 20 Aqueous Alkali Halide Solutions

A reference density database of aqueous alkali halide solutions is presented. The solutes are the 20 alkali halides consisting of the cations Li+, Na+, K+, Rb+, Cs+, and anions F−, Cl−, Br−, I−. Experimental density data of these aqueous electrolyte solutions are extensively collected and critically evaluated. A data evaluation procedure is proposed, utilizing support vector regression (SVR) to compare the experimental datasets against each other. Data evaluation is based on agreement with data from other sources rather than accuracy claimed in the literature. Datasets with large deviation from others are identified and removed. The proposed reference database consists of 11 081 data points of 586 datasets from 309 references. Maximum deviations between the selected datasets do not exceed 1%, and are smaller than 0.5% for most of the aqueous alkali halide solutions. SVR models are also trained based on the reference database. Data distribution is visualized using a Gaussian mixture model. Applicability domains of the SVR models are analyzed using Williams plots. An executable program is provided for calculations based on the SVR models.

Systematic trends of 0[formula omitted], 1[formula omitted], 3[formula omitted] and 2[formula omitted] excited states in even-even nuclei

The spin and parity (Jπ) assignments in even-even nuclei were reviewed across the nuclear chart using the Evaluated Nuclear Structure Data File (ENSDF). The prevalence of 21+ first or lowest excited states is confirmed. The properties of 02+, 11−, and 31− lowest excited states were reexamined using the ENSDF data evaluation procedures. The Jπ systematic trends and correlations between level quantum numbers and nuclear physics phenomena are discussed.

Requirements for accurate quantification of nitrate and nitrite in molasses: Insights from an interlaboratory comparison

The quantification of nitrate and nitrite in molasses is an emerging requirement for the sugar industry. The establishment of a validated analytical methodology is necessary to comply with the EU-guidelines on maximum permissible levels currently under discussion. In the present study, validation of an anion exchange chromatographic method to determine nitrate and nitrite in molasses was performed determining key validation parameters via several stages of an interlaboratory comparison for the first time. Since a stable, homogeneous sample material was necessary for establishing quantitative accuracy, a nitrite-spiked molasses material was prepared and evaluated independently across two laboratories in a parallel study. This preliminary study revealed that quantification of nitrate and nitrite content in molasses could be achieved with excellent precision under repeatability conditions of measurement (1.21% RSD for nitrate; 1.26% RSD for nitrite) in independent laboratories but requires preservation of samples at −20 °C for long-term (>several days) storage prior the analysis. A subsequent stage involving five different participating laboratories was then undertaken to evaluate anion exchange chromatography with conductivity detection for this application within a round robin study. The first phase focused on the analysis of nitrite-spiked molasses to optimize the individual analytical practices of laboratories and to elaborate a harmonized sample preparation protocol. In the second phase the participating laboratories analyzed seven molasses samples with different pH-value, dry substance, factory origin, with nitrate levels ranging from 2931 mg/kg – 6436 mg/kg and nitrite levels ranging from 25.3 mg/kg – 109 mg/kg. The determination of precision of reproducibility conditions of measurement revealed average relative interlaboratory standard deviations of 2.5% for nitrate and of 13% for nitrite. The present study clearly demonstrates the necessity of harmonization and standardization regarding measurement and data evaluation procedures applied for controlling nitrate and nitrite in molasses. • The challenging determination of nitrite with IC in molasses is addressed. • Storage of molasses at −20 °C is necessary to ensure sample stability. • Interlaboratory comparison with five laboratories is performed. • Harmonization and standardization of methods are identified to be necessary.

Challenges and opportunities of water quality monitoring and multi-stakeholder management in small islands: the case of Santa Cruz, Galápagos (Ecuador)

Sustainable water resources management roots in monitoring data reliability and a full engagement of all institutions involved in the water sector. When competences and interests are overlapping, however, coordination may be difficult, thus hampering cooperative actions. This is the case of Santa Cruz Island (Galápagos, Ecuador). A comprehensive assessment on water quality data (physico-chemical parameters, major elements, trace elements and coliforms) collected since 1985 revealed the need of optimizing monitoring efforts to fill knowledge gaps and to better target decision-making processes. A Water Committee (Comité de la gestión del Agua) was established to foster the coordinated action among stakeholders and to pave the way for joint monitoring in the island that can optimize the efforts for water quality assessment and protection. Shared procedures for data collection, sample analysis, evaluation and data assessment by an open-access geodatabase were proposed and implemented for the first time as a prototype in order to improve accountability and outreach towards civil society and water users. The overall results reveal the high potential of a well-structured and effective joint monitoring approach within a complex, multi-stakeholder framework.

EXFOR-NSR PDF database: a system for nuclear knowledge preservation and data curation

Current needs of nuclear science and technology include complete, well-documented, and easily verifiable nuclear data. The complete data records require supporting nuclear bibliography, presently stored in dedicated libraries, in addition, to actual data. Experimental nuclear reaction data (EXFOR) and Nuclear Science References (NSR) databases contain compilations based on primary (journals) and secondary (conference proceedings, theses, preprints, etc.) publications, and data received from authors via private communications. The secondary library materials and private communications often represent a bottleneck for nuclear data verification, compilation, evaluation, and dissemination activities. To address this issue, bibliographic materials were scanned into PDF (Portable Document Format) files and uploaded in a relational database.The traditional scope of nuclear databases that includes meta-data and numbers derived from data in specialized formats was broadened to accommodate the large volumes of original nuclear data publications. The complete PDF publication files were stored in a relational database as Binary Large OBjects (BLOB). This unique collection of nuclear data compilations and supporting publications generate many opportunities for machine learning applications.The Web interfaces for authorized and public access to the EXFOR-NSR nuclear publications database were implemented at the U.S. National Nuclear Data Center, https://www.nndc.bnl.gov/ and IAEA Nuclear Data Section, https://www-nds.iaea.org/. The current system is complementary to major nuclear libraries and narrowly focused on nuclear data compilation and evaluation procedures. The contents of the PDF database, details of implementation, and Web interface are described. New capabilities for data curation, knowledge preservation, worldwide dissemination, and natural language processing (NLP) applications are given.

A detailed uncertainty analysis of EI-MBMS data from combustion experiments

Electron ionization molecular-beam mass spectrometry (EI-MBMS) is a widely used analytical method for studying the chemistry of combustion processes and for providing quantitative validation targets for kinetic model development often in form of species mole fraction profiles. The present study focuses on the determination of the uncertainties of such data, which result from the mass spectrometric measurements as well as from the data evaluation procedure, in particular through the use of different calibration methods, i.e., through a direct calibration of the instrument, a convolution procedure, and through the method of Relative Ionization Cross Sections (RICS). A series of calibration experiments were carried out using two independent time-of-flight mass spectrometers in order to check the influence of experimental and instrumental parameters on the uncertainties. The data obtained reveal several key contributors to the uncertainty, which are, among others, the signal intensity of a species in the mass spectrum, the instability of instrumental parameters, the species itself, and the calibration method.The propagation of these uncertainties from the different calibration methods as well as from the instrumental inconstancies into the final uncertainties of the mole fractions is further demonstrated using a gaussian error propagation and provision of sensitivities for different uncertainty sources is given. It was found that most of the uncertainties of the mole fractions reported in the literature are smaller than those reported here and presumably only consider the reproducibility of the signal.The use of two independent mass spectrometers for the experiments also revealed that the uncertainties determined for one instrument cannot be directly transferred to another especially for the method of direct calibration due to differences in the signal reproducibility, but that the uncertainties only change marginal for the semi-theoretical approaches.

Mapping of Spatio-Temporal Changes of Surface Water Using Sentinel-1 SAR Images

Exploration of surface water bodies and their spatial definition has great importance in water resources management and helps understand hydrological processes in the country. Fast, regular, and effective ways of mapping watercourses and their surroundings through remote sensing methods are crucial tools for capturing change and predicting hazards. The last decades have brought new data products, open-source software, and evaluation procedures that allow low-cost mapping of surface water objects. A widespread and sought-after option for this type of mapping is the use of SAR (Synthetic Aperture Radar) image products. Just through SAR technology that it is possible to identify changes in water in a relatively short time and at the same time under any meteorological conditions thanks to backscattered microwave radiation. This paper presents the possibilities of using SAR technology and its data for long-term temporal mapping of meteorological-hydrological changes in surface water using satellite images of Sentinel-1 product level GRD. As regards surface water extraction, this process is performing by segmenting the threshold values according to the Otsu principle. The water surfaces are then interpreted into the form of water masks of objects by the binarization of the final image. These values are subsequently compared with the supervised classification RFC (Random Forest Classifier) method results. Suitable processing and evaluation procedures conclude that the more suitable polarization configuration for mapping water bodies is VV (vertical-vertical) polarization. As for speckle filter tools to eliminate radar noise, the most suitable option seems to be using a Lee filter. To achieve more accurate results of the extracted water bodies, it is then appropriate to implement quantitative statistical indicators of accuracy and their numerical interpretation of the reliability of results. This paper aims to demonstrate the advantages of using satellite SAR images for spatiotemporal mapping of surface water in the landscape to observe hydrological processes due to inundation, ecological and meteorological changes, and anthropogenic activity.

Wall Temperature Measurements in a Full-Scale Gas Turbine Combustor Test Rig With Fiber Coupled Phosphor Thermometry

Abstract Wall temperature measurements with fiber coupled online phosphor thermometry were, for the first time, successfully performed in a full-scale H-class Siemens gas turbine combustor. Online wall temperatures were obtained during high-pressure combustion tests up to 8 bar at the Siemens Clean Energy Center (CEC) test facility. Since optical access to the combustion chamber with fibers being able to provide high laser energies is extremely challenging, we developed a custom-built measurement system consisting of a water-cooled fiber optic probe and a mobile measurement container. A suitable combination of chemical binder and thermographic phosphor was identified for temperatures up to 1800 K on combustor walls coated with a thermal barrier coating (TBC). To our knowledge, these are the first measurements reported with fiber coupled online phosphor thermometry in a full-scale high-pressure gas turbine combustor. Details of the setup and the measurement procedures will be presented. The measured signals were influenced by strong background emissions probably from CO*2 chemiluminescence. Strategies for correcting background emissions and data evaluation procedures are discussed. The presented measurement technique enables the detailed study of combustor wall temperatures and using this information an optimization of the gas turbine cooling design.

Experimental Methods for Measuring the Breakup Frequency in Turbulent Emulsification: A Critical Review

The growing interest in using population balance modeling to describe emulsification processes has spurred an interest in experimentally measuring the breakup frequency. This contribution classifies, compares, and critically reviews the different methods that have been suggested for measuring the breakup frequency, applicable to emulsification devices. Two major approaches can be seen in previous studies. The first is ‘single drop breakup experiment’-based studies, which estimate the breakup frequency by observing the fate of individual drops. The second approach involves ‘emulsification experiment’-based studies, which combine measured drop-size distributions with assumptions to allow for estimations of the breakup frequency. This second approach can be further subdivided in three types: Parametric determination, inverse self-similarity-based methods, and direct back-calculation methods. Each of these methods are reviewed in terms of their implementation, reliability, and validity. Suggestions of methodological considerations for future studies are given for each class, together with more general suggestions for further investigations. The overall objective is to provide emulsification researchers with background information when choosing which method to use for measuring the breakup frequency and with support when setting up experiments and data evaluation procedures.

The measurement of helium leakages through flange gaskets for gas-cooled fast reactors

The study deals with the development of a method that would reliably determine the tightness of flange joints of the helium circuit of a gas-cooled fast reactor (GFR). The proposed procedure and equipment enable the parallel measurement of the helium leakage from a high-pressure cell and He contamination in the cell by the diffusion of gases from the ambient atmosphere against the pressure gradient. The self-designed apparatus is constructed for the performance of long-term tests of both parameters (i.e. both He leakage and its contamination) at a temperature of 400 °C and a pressure of 20 MPa. Nevertheless, the construction limits of the device at which the measurement can be safely carried out are 450 °C/35 MPa. The permanent gases diffusing into helium through the gasket were analyzed by a gas chromatograph with a PDHID detector, whereas the He leakage was determined using a high-sensitivity TCD. The article presents continuous results of tests carried out at ambient temperature. The procedures for data measurement and evaluation are demonstrated on one selected type of gasket with the inner diameter of 44 mm, the outer diameter of 79 mm and the thickness of 14.2 mm.

Experimental methods and data evaluation procedures for the determination of radical copolymerization reactivity ratios

Article Experimental methods and data evaluation procedures for the determination of radical copolymerization reactivity ratios was published on January 1, 2020 in the journal Chemistry International (volume 42, issue 1).

Recommended criteria for the evaluation of bacterial mutagenicity data (Ames test)

A committee was constituted within the International Workshop on Genetic Toxicology Testing (IWGT) to evaluate the current criteria for a valid Ames test and to provide recommendations for interpretation of test results. Currently, determination of a positive vs. a negative result is made by applying various data evaluation procedures for comparing dosed plates with the concurrent solvent control plates. These evaluation procedures include a requirement for a specific fold increase (2- or 3-fold, specific to the bacterial strain), formal statistical procedures, or subjective (expert judgment) evaluation. After extensive discussion, the workgroup was not able to reach consensus recommendations in favor of any of these procedures. There was a consensus that combining additional evaluation criteria to the comparison between dosed plates and the concurrent solvent control plates improves test interpretation. The workgroup recommended using these additional criteria because the induction of mutations is a continuum of responses and there is no biological relevance to a strict dividing line between a positive (mutagenic) and not-positive (nonmutagenic) response. The most useful additional criteria identified were a concentration-response relationship and consideration of a possible increase above the concurrent control in the context of the laboratory’s historical solvent control values for the particular tester strain. The workgroup also emphasized the need for additional testing to resolve weak or inconclusive responses, usually with altered experimental conditions chosen based on the initial results. Use of these multiple criteria allowed the workgroup to reach consensus on definitions of “clear positive” and “clear negative” responses which would not require a repeat test for clarification. The workgroup also reached consensus on recommendations to compare the responses of concurrent positive and negative controls to historical control distributions for assay acceptability, and the use of control charts to determine the validity of the individual test.

Estimation of Local Heading Patterns of Nocturnal Migrants using Orientation Cages

Abstract Busse P. 2018. Estimation of local heading patterns of nocturnal Migrants using orientation cages. Ring 40: 31-58 The main aim of this paper is to compare the results of two data evaluation procedures used for presenting the data from the orientation cage field tests. Both procedures accept multimodality of the data and multimodality of the headings of an individual bird as well as migrating population. The goal is to reach acceptable level of migration patterns presentation in biological sense, taking under consideration a flexibility of the real movements, depending on specific weather and landscape parameters. Such knowledge is absolutely necessary for estimating migration bottle-necks and the long-term studies on influence of the climate changes on migration patterns. The material used for the comparison of the procedures was collected in years 2001-2007 by the team of the Bulgarian Ringing Station Kalimok (44°00’N, 26°26’E) within the frame of the SEEN (SE European Bird Migration Network) activity and kindly shared for evaluation. The data were obtained using the standard SEEN methods, with the standard Busse’s cage working procedure of the field tests. The material contains data on four species of nocturnal migrants living in different habitats: the Great Reed Warbler, Acrocephalus arundinaceus (ACR.ARU), the Sedge Warbler, A. schoenobaenus (ACR.ENO), the Willow Warbler, Phylloscopus trochilus (PHY.LUS) and the Whitethroat, Sylvia communis (SYL.COM). There are confirmed earlier conclusions that so called „classic” unimodal procedure is not applicable to the orientation cage data resulted from any field procedure. There are available two evaluation procedures that base on the same general assumptions: multimodality of distributions that reflects combination of several unimodal partial distributions, that can be described both using sophisticated Bayesian „Calculation” method and much simpler „Estimation” procedure. Results of both procedures are enough close to each other that they can be used for describing local and general heading patterns of migration of the nocturnal migratory movements studied using orientation cages.