WorldWideScience

Sample records for classification reference material

  1. Nanomaterials for environmental studies: classification, reference material issues, and strategies for physico-chemical characterisation.

    Science.gov (United States)

    Stone, Vicki; Nowack, Bernd; Baun, Anders; van den Brink, Nico; Kammer, Frank von der; Dusinska, Maria; Handy, Richard; Hankin, Steven; Hassellöv, Martin; Joner, Erik; Fernandes, Teresa F

    2010-03-01

    NanoImpactNet is a European Commission Framework Programme 7 (FP7) funded project that provides a forum for the discussion of current opinions on nanomaterials in relation to human and environmental issues. In September 2008, in Zurich, a NanoImpactNet environmental workshop focused on three key questions: 1. What properties should be characterised for nanomaterials used in environmental and ecotoxicology studies? 2. What reference materials should be developed for use in environmental and ecotoxicological studies? 3. Is it possible to group different nanomaterials into categories for consideration in environmental studies? Such questions have been, at least partially, addressed by other projects/workshops especially in relation to human health effects. Such projects provide a useful basis on which this workshop was based, but in this particular case these questions were reformulated in order to focus specifically on environmental studies. The workshop participants, through a series of discussion and reflection sessions, generated the conclusions listed below. The physicochemical characterisation information identified as important for environmental studies included measures of aggregation/agglomeration/dispersability, size, dissolution (solubility), surface area, surface charge, surface chemistry/composition, with the assumption that chemical composition would already be known. There is a need to have test materials for ecotoxicology, and several substances are potentially useful, including TiO(2) nanoparticles, polystyrene beads labelled with fluorescent dyes, and silver nanoparticles. Some of these test materials could then be developed into certified reference materials over time. No clear consensus was reached regarding the classification of nanomaterials into categories to aid environmental studies, except that a chemistry-based classification system was a reasonable starting point, with some modifications. It was suggested, that additional work may be

  2. Reference Materials System: materials policy information system

    Energy Technology Data Exchange (ETDEWEB)

    Bhagat, N.K.; Hoffman, K.C.

    1979-01-01

    The social and economic development of a nation is dependent on a reliable supply of materials and energy and on the efficient utilization of these resources. Decision making in industry and the formulation of government policies require a comprehensive information base encompassing the technical, economic, and environmental factors involved in the flow of materials through production processes and the overall economy. The Reference Materials System (RMS) is a network description of the flow of materials from resource extraction through refinement, production, and transportation processes to the utilization, maintenance, and recycling operations. The system has been employed for the assessment of material production technologies and for the evaluation of substitution possibilities. The RMS provides a framework for integrating engineering and economic information into a comprehensive systems framework. The network flow diagram is quantified in terms of the mass flow of all renewable and nonrenewable materials on an annual basis through each step of the system. A variety of data elements including capital and labor requirements may be organized in this framework to provide a Materials Policy Data Base. This process description of the materials system may also be coupled with economic policy models of the input--output or econometric variety to ensure proper analysis of the role of materials in the overall economy.

  3. 40 CFR 1042.910 - Reference materials.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Reference materials. 1042.910 Section... Other Reference Information § 1042.910 Reference materials. Documents listed in this section have been... information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov...

  4. 40 CFR 1043.100 - Reference materials.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Reference materials. 1043.100 Section... § 1043.100 Reference materials. Documents listed in this section have been incorporated by reference into... the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov...

  5. 40 CFR 86.1 - Reference materials.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Reference materials. 86.1 Section 86.1... EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES § 86.1 Reference materials. Link to an amendment... notice of change must be published in the Federal Register and the material must be available to the...

  6. 40 CFR 90.7 - Reference materials.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Reference materials. 90.7 Section 90.7... EMISSIONS FROM NONROAD SPARK-IGNITION ENGINES AT OR BELOW 19 KILOWATTS General § 90.7 Reference materials... Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to...

  7. Maps and related cartographic materials cataloging, classification, and bibliographic control

    CERN Document Server

    Larsgarrd L, Mary

    2013-01-01

    Make maps and other cartographic materials more easily accessible and usable!Maps and Related Cartographic Materials: Cataloging, Classification, and Bibliographic Control is a format-focused reference manual for catalogers that should occupy a prominent place on your reference shelf.Outside of standard cartographic cataloging tools, the bibliographic treatment of all forms of cartographic materials has never been compiled into one useful source. This book separately examines the treatment of all major cartographic format types and outlines the way each should be cataloged.

  8. 40 CFR 89.6 - Reference materials.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Reference materials. 89.6 Section 89.6... EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES General § 89.6 Reference materials. (a... information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov...

  9. 40 CFR 91.6 - Reference materials.

    Science.gov (United States)

    2010-07-01

    ... forth material from the Society of Automotive Engineers which has been incorporated by reference. The... Automotive Engineers International, 400 Commonwealth Dr., Warrendale, PA 15096-0001. Document number and name.... (1) ASTM material. The following table sets forth material from the American Society for Testing...

  10. Material Classification Using Raw Time-of-Flight Measurements

    KAUST Repository

    Su, Shuochen

    2016-12-13

    We propose a material classification method using raw time-of-flight (ToF) measurements. ToF cameras capture the correlation between a reference signal and the temporal response of material to incident illumination. Such measurements encode unique signatures of the material, i.e. the degree of subsurface scattering inside a volume. Subsequently, it offers an orthogonal domain of feature representation compared to conventional spatial and angular reflectance-based approaches. We demonstrate the effectiveness, robustness, and efficiency of our method through experiments and comparisons of real-world materials.

  11. Polyfluorinated substances in abiotic standard reference materials

    NARCIS (Netherlands)

    Reiner, J.L.; Blaine, A.C.; Higgins, C.P.; Kwadijk, C.J.A.F.

    2015-01-01

    The National Institute of Standards and Technology (NIST) has a wide range of Standard Reference Materials (SRMs) which have values assigned for legacy organic pollutants and toxic elements. Existing SRMs serve as homogenous materials that can be used for method development, method validation, and m

  12. Reference materials and representative test materials: the nanotechnology case

    Energy Technology Data Exchange (ETDEWEB)

    Roebben, G., E-mail: gert.roebben@ec.europa.eu [Joint Research Centre of the European Commission, Institute for Reference Materials and Measurements (Belgium); Rasmussen, K. [Joint Research Centre of the European Commission, Institute for Health and Consumer Protection (Italy); Kestens, V.; Linsinger, T. P. J. [Joint Research Centre of the European Commission, Institute for Reference Materials and Measurements (Belgium); Rauscher, H. [Joint Research Centre of the European Commission, Institute for Health and Consumer Protection (Italy); Emons, H. [Joint Research Centre of the European Commission, Institute for Reference Materials and Measurements (Belgium); Stamm, H. [Joint Research Centre of the European Commission, Institute for Health and Consumer Protection (Italy)

    2013-03-15

    An increasing number of chemical, physical and biological tests are performed on manufactured nanomaterials for scientific and regulatory purposes. Existing test guidelines and measurement methods are not always directly applicable to or relevant for nanomaterials. Therefore, it is necessary to verify the use of the existing methods with nanomaterials, thereby identifying where modifications are needed, and where new methods need to be developed and validated. Efforts for verification, development and validation of methods as well as quality assurance of (routine) test results significantly benefit from the availability of suitable test and reference materials. This paper provides an overview of the existing types of reference materials and introduces a new class of test materials for which the term 'representative test material' is proposed. The three generic concepts of certified reference material, reference material(non-certified) and representative test material constitute a comprehensive system of benchmarks that can be used by all measurement and testing communities, regardless of their specific discipline. This paper illustrates this system with examples from the field of nanomaterials, including reference materials and representative test materials developed at the European Commission's Joint Research Centre, in particular at the Institute for Reference Materials and Measurements (IRMM), and at the Institute for Health and Consumer Protection (IHCP).

  13. Myths of Isotopic Reference Materials Busted

    Science.gov (United States)

    Coplen, T.

    2007-12-01

    During the past several years, the determination of the isotopic abundances of elements including H, Li, B, C, N, O, Mg, Si, S, Cl, Ca, Cr, Fe, Cu, Zn, Tl, and Se has substantially increased because of expanded use in hydrology, environmental studies, microbiology, forensic investigations, atmospheric investigations, oceanography, etc. Improvements in instrumentation enable increasingly precise isotope-amount-ratio measurements in these fields, but these improvements in precision commonly do not lead to improvements in accuracy because of the lack or improper use of isotopic reference materials. When properly used, these critically important materials enable any laboratory worldwide to measure the same homogeneous sample and report the same isotopic abundance within analytical uncertainty. For example, for stable isotopic analysis of gaseous hydrogen samples, the agreement among 36 laboratories worldwide before normalization to any hydrogen gas reference material was 11.8 per mill. After normalization to anchors (gaseous H isotopic reference materials) at each end of the delta H-2 scale, the agreement was 0.85 per mill, an improvement of more than an order of magnitude. Consistency of delta C-13 measurements often can be improved by nearly 50 percent by anchoring the delta C-13 scale with two isotopic reference materials differing substantially in C-13 mole fraction, namely NBS 19 calcite and L-SVEC lithium carbonate. Agreement of delta C-13 values of four expert laboratories analyzing USGS40 L- glutamic acid by CF-IRMS methods improved from 0.084 to 0.015 per mill with use of the two scale anchors (NBS 19 and L-SVEC). Solid oxygen isotopic reference materials (IAEA-600 caffeine, IAEA-601 and IAEA-602 benzoic acids, IAEA-NO-3, USGS32, USGS34, and USGS35 nitrates, NBS-127, IAEA-SO-5, and IAEA-SO-6 barium sulfates) are poorly calibrated. Calibrating these solids to the VSMOW-SLAP reference water scale has been very difficult because both the solids and reference

  14. Standard reference materials for thorium analysis.

    Science.gov (United States)

    Holmes, L

    2001-01-01

    Reference materials (RMs) are used in analytical measurements for several purposes--to develop and validate analytical measurements, as quality control indicators and for calibration. It is therefore essential that suitable reference materials are available. Because thorium is usually found in very acid-resistant, mineral phases, this becomes even more critical when techniques such as ICP-MS are used, which require complete sample digestion. This paper gives an overview of the reference materials that are currently available for thorium (232Th and other thorium isotopes) in various matrices, sources and indicative costs. The IAEA database is identified as a particularly useful source of information, and the website address is: http://www.iaea.org/programmes/nahunet/e4/nmrm/index.htm A brief summary of the discussion held at the '1st European Workshop on the Analysis of Thorium in Workplace Materials', regarding reference materials, is given at the end of the paper. A general need for new RMs, specifically for workplace materials, was identified as a priority.

  15. Preparation of Reference Material 8504, Transformer Oil

    OpenAIRE

    Poster, Dianne L.; Schantz, Michele M.; Wise, Stephen A.

    2005-01-01

    A new reference material (RM), RM 8504, has been prepared for use as a diluent oil with Aroclors in transformer oil Standard Reference Materials (SRMs) 3075 to 3080 and SRM 3090 when developing and validating methods for the determination of polychlorinated biphenyls (PCBs) as Aroclors in transformer oil or similar matrices. SRMs 3075-3080 and SRM 3090 consist of individual Aroclors in the same transformer oil that was used to prepare RM 8504. A unit of RM 8504 consists of one bottle containi...

  16. Preparation of Reference Material 8504, Transformer Oil.

    Science.gov (United States)

    Poster, Dianne L; Schantz, Michele M; Wise, Stephen A

    2005-01-01

    A new reference material (RM), RM 8504, has been prepared for use as a diluent oil with Aroclors in transformer oil Standard Reference Materials (SRMs) 3075 to 3080 and SRM 3090 when developing and validating methods for the determination of polychlorinated biphenyls (PCBs) as Aroclors in transformer oil or similar matrices. SRMs 3075-3080 and SRM 3090 consist of individual Aroclors in the same transformer oil that was used to prepare RM 8504. A unit of RM 8504 consists of one bottle containing approximately 100 mL of transformer oil. No additional constituents have been added to the oil.

  17. Spectral Band Selection for Urban Material Classification Using Hyperspectral Libraries

    Science.gov (United States)

    Le Bris, A.; Chehata, N.; Briottet, X.; Paparoditis, N.

    2016-06-01

    In urban areas, information concerning very high resolution land cover and especially material maps are necessary for several city modelling or monitoring applications. That is to say, knowledge concerning the roofing materials or the different kinds of ground areas is required. Airborne remote sensing techniques appear to be convenient for providing such information at a large scale. However, results obtained using most traditional processing methods based on usual red-green-blue-near infrared multispectral images remain limited for such applications. A possible way to improve classification results is to enhance the imagery spectral resolution using superspectral or hyperspectral sensors. In this study, it is intended to design a superspectral sensor dedicated to urban materials classification and this work particularly focused on the selection of the optimal spectral band subsets for such sensor. First, reflectance spectral signatures of urban materials were collected from 7 spectral libraires. Then, spectral optimization was performed using this data set. The band selection workflow included two steps, optimising first the number of spectral bands using an incremental method and then examining several possible optimised band subsets using a stochastic algorithm. The same wrapper relevance criterion relying on a confidence measure of Random Forests classifier was used at both steps. To cope with the limited number of available spectra for several classes, additional synthetic spectra were generated from the collection of reference spectra: intra-class variability was simulated by multiplying reference spectra by a random coefficient. At the end, selected band subsets were evaluated considering the classification quality reached using a rbf svm classifier. It was confirmed that a limited band subset was sufficient to classify common urban materials. The important contribution of bands from the Short Wave Infra-Red (SWIR) spectral domain (1000-2400 nm) to material

  18. A reference material for dynamic displacement calibration

    Science.gov (United States)

    Davighi, A.; Hack, E.; Patterson, E.; Whelan, M.

    2010-06-01

    Calibration of displacement and strain measurement systems is an essential step in providing traceability and confidence in stress and strain distributions obtained from experiment and used to validate simulations employed in engineering design. Reference materials provide a simple, well-defined distribution of the measured quantity that can be traced to an international standard and can be used to assess the uncertainty associated with the measurement system. Previous work has established a reference material and procedure for calibrating optical systems for measuring static, in-plane strain distributions and also demonstrated its use. A new effort is in progress to extend this work to the measurement of three-dimensional displacement distributions induced by cyclic and dynamic loading, including transients and large-scale deformation. The first step in this effort has been to define both the essential and desirable attributes of a reference material for calibrating systems capable of measurements of dynamic displacement and strain. An international consortium of research laboratories, system designers, manufacturers and end-users has identified a list of attributes and members of the experimental mechanics community have been asked to weight the importance of these attributes. The attributes are being utilised to evaluate candidate designs for the reference material which have been generated through a series of brain-storming sessions within the consortium.

  19. Development of synthetic environmental radioactivity reference materials.

    Science.gov (United States)

    Harms, Arvic; Gilligan, Chris

    2012-09-01

    In this paper, a novel way of developing synthetic environmental radioactivity reference materials via the sol-gel process is described. Two solid reference materials (both having a SiO(2) matrix) were synthesised by hydrolysing a liquid mixture of tetraethyl orthosilicate (TEOS), ethanol and standardised mixed radionuclide solutions. The certified values, which were in the Bqg(-1) range, for the radionuclides in the material were determined by NPL and compared with results from measurements made by 36 organisations from 17 countries using a 'consensus' approach. The measurements were made within two wider test exercises (the NPL Environmental Radioactivity Proficiency Test Exercises 2009 and 2010). Certified activity concentration values were obtained for (60)Co, (133)Ba, (134)Cs, (137)Cs, (152)Eu, (154)Eu and (241)Am and indicative values were obtained for (55)Fe and (90)Sr.

  20. Hypothesis-driven classification of materials using nuclear magnetic resonance relaxometry

    Science.gov (United States)

    Espy, Michelle A.; Matlashov, Andrei N.; Schultz, Larry J.; Volegov, Petr L.

    2016-08-09

    Technologies related to identification of a substance in an optimized manner are provided. A reference group of known materials is identified. Each known material has known values for several classification parameters. The classification parameters comprise at least one of T.sub.1, T.sub.2, T.sub.1.rho., a relative nuclear susceptibility (RNS) of the substance, and an x-ray linear attenuation coefficient (LAC) of the substance. A measurement sequence is optimized based on at least one of a measurement cost of each of the classification parameters and an initial probability of each of the known materials in the reference group.

  1. Development studies of captopril certified reference material

    Directory of Open Access Journals (Sweden)

    Raquel Nogueira

    2011-06-01

    Full Text Available This paper describes the studies performed with the candidate Certified Reference Material (CRM of captopril, the first CRM of an active pharmaceutical ingredient (API in Brazil, including determination of impurities (organic, inorganic and volatiles, homogeneity testing, short- and long-term stability studies, calculation of captopril content using the mass balance approach, and estimation of the associated measurement uncertainty.Este artigo descreve os estudos realizados com o candidato a Material de Referência Certificado (MRC de captopril, primeiro MRC de fármacos no Brasil, incluindo a determinação de impurezas (orgânicas, inorgânicas e voláteis, testes de homogeneidade, testes de estabilidade de curta e longa duração, cálculo do teor de captopril por balanço de massa e estimativa da incerteza de medição associada ao valor certificado.

  2. Reference material systems: a sourcebook for material assessment

    Energy Technology Data Exchange (ETDEWEB)

    Bhagat, N. (ed.)

    1976-12-01

    A reference set of data related to material systems and a framework for carrying out the material technologies assessment are presented. While the bulk of renewables have been considered in this report, the nonrenewable materials dealt with here include structural materials only, such as steel, aluminum, cement and concrete, and bricks. The complete data set is supposed to include material flows, energy requirements, capital and labor inputs, and environmental effects for each process that a resource must go through to become a useful material for an end use. Although effort has been made to obtain as much information as possible, considerable gaps in data, apparent throughout this report, could not be avoided. A new material technology can be evaluated by substituting that technology for appropriate elements of the reference materials system and calculating the net change in material resource, energy, capital and labor requirements, and environmental impacts. This combination of information thus serves as a means of evaluating the potential benefits to be gained by research in various material technologies.

  3. On the traceability of gaseous reference materials

    Science.gov (United States)

    Brown, Richard J. C.; Brewer, Paul J.; Harris, Peter M.; Davidson, Stuart; van der Veen, Adriaan M. H.; Ent, Hugo

    2017-06-01

    The complex and multi-parameter nature of chemical composition measurement means that establishing traceability is a challenging task. As a result incorrect interpretations about the origin of the metrological traceability of chemical measurement results can occur. This discussion paper examines why this is the case by scrutinising the peculiarities of the gas metrology area. It considers in particular: primary methods, dissemination of metrological traceability and the role of documentary standards and accreditation bodies in promulgating best practice. There is also a discussion of documentary standards relevant to the NMI and reference material producer community which need clarification, and the impact which key stakeholders in the quality infrastructure can bring to these issues.

  4. Reference benchmarks relating to great groups of genetic soil classification of China with soil taxonomy

    Institute of Scientific and Technical Information of China (English)

    SHI Xuezheng; YU Dongsheng; SUN Weixia; WANG Hongjie; ZHAO Qiguo; GONG Zitong

    2004-01-01

    Soil classification forms the basis for the exchange and extension of research findings in soil science and for the modernization of management of soil resources. This paper systematically reviews the compatibility of the genetic soil classification of China (GSCC) and soil taxonomy (ST).This includes a study of the evolution and consummation of the GSCC and assessment of the databases and methods of the study. Using the "Soil Species of China (six volumes)"and some provincial soil species as the basic material, the authors gathered information from 2540 soil species. Based on the key described in ST, the 2540 soil species were taxonomically classified into corresponding soil orders, suborders,great groups and subgroups and then matched with corresponding map units in the 1: 1000000 digital soil map of China. Using the high-level classification units of the two soil classification systems, and the attributes of each soil species,the sizes of distribution areas were mapped. The soil distribution results were analyzed and compared statistically. The reference compatibility between the great groups used in GSCC system and the soil orders of the ST is discussed. It is believed that 20 great groups display maximum referencibility >95% and 15 great groups depict maximum referencibility in the range of 70%-95%, which can be cited as reference benchmarks. The remaining 25 great groups are less compatible (with maximum referencibility <70%) and need further study, or require referencing at lower classification levels or at a regional level to help to improve the accuracy of the reference.

  5. Quality-Oriented Classification of Aircraft Material Based on SVM

    Directory of Open Access Journals (Sweden)

    Hongxia Cai

    2014-01-01

    Full Text Available The existing material classification is proposed to improve the inventory management. However, different materials have the different quality-related attributes, especially in the aircraft industry. In order to reduce the cost without sacrificing the quality, we propose a quality-oriented material classification system considering the material quality character, Quality cost, and Quality influence. Analytic Hierarchy Process helps to make feature selection and classification decision. We use the improved Kraljic Portfolio Matrix to establish the three-dimensional classification model. The aircraft materials can be divided into eight types, including general type, key type, risk type, and leveraged type. Aiming to improve the classification accuracy of various materials, the algorithm of Support Vector Machine is introduced. Finally, we compare the SVM and BP neural network in the application. The results prove that the SVM algorithm is more efficient and accurate and the quality-oriented material classification is valuable.

  6. Environmental reference materials methods and case studies

    DEFF Research Database (Denmark)

    Schramm-Nielsen, Karina Edith

    1998-01-01

    This thesis introduces the reader to the concept of chemical environmental reference materials and their role in traceability and chemical analyses of the environment. A number of models and principles from the literature are described. Some suggestions are made as to how stability studies can...... be modelled when the length of the study is unknown. Experimental data has been collected from two stability studies of aqueous matrices. The first study regards the stability of TN NO² + ³-N and n in autoclaved wastewater samples over a period of 22 months. Data was collected specifically for this study...... with two purposes: 1) to investigate the stability of selected analytes in the chosen matrices and 2) to explore the applicability of various statistical models for the description of stability studies. Three univariate and three multivariate stability models have been applied to these data sets...

  7. Enhanced material classification using turbulence-degraded polarimetric imagery.

    Science.gov (United States)

    Hyde, Milo W; Schmidt, Jason D; Havrilla, Michael J; Cain, Stephen C

    2010-11-01

    An enhanced material-classification algorithm using turbulence-degraded polarimetric imagery is presented. The proposed technique improves upon an existing dielectric/metal material-classification algorithm by providing a more detailed object classification. This is accomplished by redesigning the degree-of-linear-polarization priors in the blind-deconvolution algorithm to include two subclasses of metals--an aluminum group classification (includes aluminum, copper, gold, and silver) and an iron group classification (includes iron, titanium, nickel, and chromium). This new classification provides functional information about the object that is not provided by existing dielectric/metal material classifiers. A discussion of the design of these new degree-of-linear-polarization priors is provided. Experimental results of two painted metal samples are also provided to verify the algorithm's accuracy.

  8. Material control system simulator program reference manual

    Energy Technology Data Exchange (ETDEWEB)

    Hollstien, R.B.

    1978-01-24

    A description is presented of a Material Control System Simulator (MCSS) program for determination of material accounting uncertainty and system response to particular adversary action sequences that constitute plausible material diversion attempts. The program is intended for use in situations where randomness, uncertainty, or interaction of adversary actions and material control system components make it difficult to assess safeguards effectiveness against particular material diversion attempts. Although MCSS may be used independently in the design or analysis of material handling and processing systems, it has been tailored toward the determination of material accountability and the response of material control systems to adversary action sequences.

  9. 40 CFR 1065.1010 - Reference materials.

    Science.gov (United States)

    2010-07-01

    ... and Technology that we have incorporated by reference. The first column lists the number and name of... Procedures,” Amended July 30, 2002, Mobile Source Division, California Air Resources Board 1065.805...

  10. Recent production of candidate reference materials at IRMM

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, G.N.; Pauwels, J.; Le Guern, L.; Schimmel, H.; Trapmann, S. [Commission of the European Communities, Geel (Belgium). Joint Research Centre

    2001-06-01

    In the execution of its mission to promote a common European measurement system in support of EU policies, IRMM's Reference Materials Unit is currently involved in preparation of proficiency-testing samples and candidate reference materials. Recent work related to bovine spongiform encephalopathy in cows, genetically modified organisms, and a variety of environmental materials is described. (orig.)

  11. Special nuclear material information, security classification guidance. Instruction

    Energy Technology Data Exchange (ETDEWEB)

    Flickinger, A.

    1982-12-03

    The Instruction reissues DoD Instruction 5210.67, July 5, 1979, and provides security classification guidance for information concerning significant quantities of special nuclear material, other than that contained in nuclear weapons and that used in the production of energy in the reactor plant of nuclear-powered ships. Security classification guidance for these data in the latter two applications is contained in Joint DoE/DoD Nuclear Weapons Classification Guide and Joint DoE/DoD Classification Guide for the Naval Nuclear Propulsion Program.

  12. 40 CFR 92.5 - Reference materials.

    Science.gov (United States)

    2010-07-01

    ... § 92.113 ASTM D 1945-91, Standard Test Method for Analysis of Natural Gas by Gas Chromatography § 92... Supercritical Fluid Chromatography § 92.113 ASTM E 29-93a, Standard Practice for Using Significant Digits in... follows: Document number and name 40 CFR part 92 reference SAE Paper 770141, Optimization of a...

  13. AOAC INTERNATIONAL's Technical Division on Reference Materials (TDRM) Reference Materials Database.

    Science.gov (United States)

    Zink, Donna

    2016-09-01

    The Technical Division on Reference Materials (TDRM) of AOAC INTERNATIONAL recommends policy and criteria to facilitate the development and use of reference materials (RMs) in the validation, implementation, and routine use of AOAC INTERNATIONAL methods. To aid analysts in these areas, TDRM has developed a searchable online database to identify RMs suitable for use with AOAC Official Methods of Analysis(SM) (OMA). RMs can be queried by analyte, by analyte and matrix, or by the selection of an OMA, based on analytes and matrixes described within the scope of the selected method. Only essential information is included in the database, to maximize usefulness and minimize the effort required to keep information current. Additional information, such as measurement uncertainty and purchasing instructions, is available through a link to the producer's Web site, when that information is available online. Data sets are solicited on a voluntary basis from National Metrology Institutes and accredited producers. Consideration of ease-of-use and ease-of-operation is a guiding principle in this database, as is cost management.

  14. Corrosion reference for geothermal downhole materials selection

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, P.F. II, Smith, C.C.; Keeney, R.C.; Kirk, D.K.; Conover, M.F.

    1983-03-01

    Geothermal downhole conditions that may affect the performance and reliability of selected materials and components used in the drilling, completion, logging, and production of geothermal wells are reviewed. The results of specific research and development efforts aimed at improvement of materials and components for downhole contact with the hostile physicochemical conditions of the geothermal reservoir are discussed. Materials and components covered are tubular goods, stainless steels and non-ferrous metals for high-temperature downhole service, cements for high-temperature geothermal wells, high-temperature elastomers, drilling and completion tools, logging tools, and downhole pumps. (MHR)

  15. Homogeneity studies in reference materials with Zeeman solid sampling GFAAS

    Energy Technology Data Exchange (ETDEWEB)

    Mohl, C.; Stoeppler, M.; Grobecker, K.H.

    1987-09-01

    The homogeneity of lead and cadmium in reference materials was investigated by solid sampling GFAAS. The following materials were comparatively analyzed: Standard reference materials from NBS, Washington 1567 wheat flour, 1568 rice flour and 1577a bovine liver, certified reference materials from BCR, Brussels, No 63 milk powder, No 184 bovine muscle, No 185 bovine liver, No 186 pig kidney, No 189 wholemeal flour, No 191 brown bread and a whole fish (dab) homogenate from the environmental specimen bank in the FRG. The results are remarkably different for the investigated materials.

  16. [Review of normal spectral emissivity standard reference materials].

    Science.gov (United States)

    Yu, Kun; Liu, Yu-Fang; Zhao, Yue-Jin

    2012-11-01

    In order to improve the accuracy of spectral emissivity measurement, standard reference materials of spectral emissivity as the dissemination of quantity in spectral emissivity measurement are used for the calibration of spectral emissivity measurement apparatus. In the present paper, firstly the standard reference materials data proposed by the American National Institute of Standards and Technology are introduced, and some underlying standard reference materials suggested by some metering departments in Europe are analyzed in detail For the standard reference material Armco iron and SiC proposed by some researchers, the advantages and disadvantages were explored. Finally, the characteristics of standard reference materials are summarized, and the future development of spectral emissivity measurement standard is prospected.

  17. Optimizing spectral CT parameters for material classification tasks

    Science.gov (United States)

    Rigie, D. S.; La Rivière, P. J.

    2016-06-01

    In this work, we propose a framework for optimizing spectral CT imaging parameters and hardware design with regard to material classification tasks. Compared with conventional CT, many more parameters must be considered when designing spectral CT systems and protocols. These choices will impact material classification performance in a non-obvious, task-dependent way with direct implications for radiation dose reduction. In light of this, we adapt Hotelling Observer formalisms typically applied to signal detection tasks to the spectral CT, material-classification problem. The result is a rapidly computable metric that makes it possible to sweep out many system configurations, generating parameter optimization curves (POC’s) that can be used to select optimal settings. The proposed model avoids restrictive assumptions about the basis-material decomposition (e.g. linearity) and incorporates signal uncertainty with a stochastic object model. This technique is demonstrated on dual-kVp and photon-counting systems for two different, clinically motivated material classification tasks (kidney stone classification and plaque removal). We show that the POC’s predicted with the proposed analytic model agree well with those derived from computationally intensive numerical simulation studies.

  18. The development and evaluation of reference materials for food microbiology

    NARCIS (Netherlands)

    Veld, in 't P.

    1998-01-01

    Since 1986 the National Institute of Public Health and the Environment (RIVM) has worked on the development and evaluation of microbiological reference materials (RMs) with support from the European Communities Bureau of Reference (BCR), now called Standards Measurement and Testing (SM&

  19. The development and evaluation of reference materials for food microbiology.

    NARCIS (Netherlands)

    in 't Veld, P.H.

    1998-01-01

    Since 1986 the National Institute of Public Health and the Environment (RIVM) has worked on the development and evaluation of microbiological reference materials (RMs) with support from the European Communities Bureau of Reference (BCR), now called Standards Measurement and Testing (SM&T). The RMs a

  20. The development and evaluation of reference materials for food microbiology

    NARCIS (Netherlands)

    Veld, in 't P.

    1998-01-01

    Since 1986 the National Institute of Public Health and the Environment (RIVM) has worked on the development and evaluation of microbiological reference materials (RMs) with support from the European Communities Bureau of Reference (BCR), now called Standards Measurement and Testing

  1. The objective and the prospects of creating certified reference materials of fire protection substances and materials

    Directory of Open Access Journals (Sweden)

    M. P. Dubinin

    2014-01-01

    Full Text Available The article describes the state of things in the field of production and use of fire protection materials. The need to develop certified reference materials of fire protection materials is justified.

  2. 49 CFR 1245.6 - Cross reference to standard occupational classification manual.

    Science.gov (United States)

    2010-10-01

    .... 200Professional and Administrative 201Professionals (Other Than Those Reported in 101 and 102): General Counsel... Auditors 1412. 204General and Administrative Supervisors: General Supv. 4511 and 137. Supv. 4511 and 137... REPORTS CLASSIFICATION OF RAILROAD EMPLOYEES; REPORTS OF SERVICE AND COMPENSATION § 1245.6 Cross reference...

  3. Certified reference materials and reference methods for nuclear safeguards and security.

    Science.gov (United States)

    Jakopič, R; Sturm, M; Kraiem, M; Richter, S; Aregbe, Y

    2013-11-01

    Confidence in comparability and reliability of measurement results in nuclear material and environmental sample analysis are established via certified reference materials (CRMs), reference measurements, and inter-laboratory comparisons (ILCs). Increased needs for quality control tools in proliferation resistance, environmental sample analysis, development of measurement capabilities over the years and progress in modern analytical techniques are the main reasons for the development of new reference materials and reference methods for nuclear safeguards and security. The Institute for Reference Materials and Measurements (IRMM) prepares and certifices large quantities of the so-called "large-sized dried" (LSD) spikes for accurate measurement of the uranium and plutonium content in dissolved nuclear fuel solutions by isotope dilution mass spectrometry (IDMS) and also develops particle reference materials applied for the detection of nuclear signatures in environmental samples. IRMM is currently replacing some of its exhausted stocks of CRMs with new ones whose specifications are up-to-date and tailored for the demands of modern analytical techniques. Some of the existing materials will be re-measured to improve the uncertainties associated with their certified values, and to enable laboratories to reduce their combined measurement uncertainty. Safeguards involve the quantitative verification by independent measurements so that no nuclear material is diverted from its intended peaceful use. Safeguards authorities pay particular attention to plutonium and the uranium isotope (235)U, indicating the so-called 'enrichment', in nuclear material and in environmental samples. In addition to the verification of the major ratios, n((235)U)/n((238)U) and n((240)Pu)/n((239)Pu), the minor ratios of the less abundant uranium and plutonium isotopes contain valuable information about the origin and the 'history' of material used for commercial or possibly clandestine purposes, and

  4. Evaluation of a reference material for glycated haemoglobin

    NARCIS (Netherlands)

    Weykamp, CW; Penders, TJ; Muskiet, FAJ; vanderSlik, W

    1996-01-01

    The use of lyophilized blood as a reference material for glycated haemoglobin was investigated with respect to IFCC criteria for calibrators and control materials. Ninety-two laboratories, using 11 methods, detected no changes in glycated haemoglobin content when the lyophilizate was stored for one

  5. Feasibility of a recombinant human apolipoprotein E reference material

    NARCIS (Netherlands)

    Schiele, F.; Barbier, A.; Visvikis, A.; Aggerbeck, L.; Rosseneu, M.; Havekes, L.; Huttinger, M.; Profilis, C.; Siest, G.

    1998-01-01

    The aim of this work was to prepare a recombinant apo E material and to determine its suitability as a reference material. We produced human apo E3 using recombinant DNA technology. The cDNA of human apo E3 was cloned in the pARHS bacterial expression vector and used to transfect E. Coli BL21 (DE3)

  6. Evaluation of a reference material for glycated haemoglobin

    NARCIS (Netherlands)

    Weykamp, CW; Penders, TJ; Muskiet, FAJ; vanderSlik, W

    The use of lyophilized blood as a reference material for glycated haemoglobin was investigated with respect to IFCC criteria for calibrators and control materials. Ninety-two laboratories, using 11 methods, detected no changes in glycated haemoglobin content when the lyophilizate was stored for one

  7. Stability and homogeneity of microbiological reference materials: some statistical models

    NARCIS (Netherlands)

    Heisterkamp SH; Hoogenveen RT; van Strijp-Lockefeer NGWM; Hoekstra JA; Havelaar AH; Mooijman KA

    1991-01-01

    Microbiological reference materials are being developed by the RIVM since several years. These materials consist of capsules filled with milkpowder artificially contaminated with a bacteria test strain of choice (i.e. Escherichia coli, Enterobacter cloacae, Salmonella typhimurium). Both from long

  8. A new basaltic glass microanalytical reference material for multiple techniques

    Science.gov (United States)

    Wilson, Steve; Koenig, Alan; Lowers, Heather

    2012-01-01

    The U.S. Geological Survey (USGS) has been producing reference materials since the 1950s. Over 50 materials have been developed to cover bulk rock, sediment, and soils for the geological community. These materials are used globally in geochemistry, environmental, and analytical laboratories that perform bulk chemistry and/or microanalysis for instrument calibration and quality assurance testing. To answer the growing demand for higher spatial resolution and sensitivity, there is a need to create a new generation of microanalytical reference materials suitable for a variety of techniques, such as scanning electron microscopy/X-ray spectrometry (SEM/EDS), electron probe microanalysis (EPMA), laser ablation inductively coupled mass spectrometry (LA-ICP-MS), and secondary ion mass spectrometry (SIMS). As such, the microanalytical reference material (MRM) needs to be stable under the beam, be homogeneous at scales of better than 10–25 micrometers for the major to ultra-trace element level, and contain all of the analytes (elements or isotopes) of interest. Previous development of basaltic glasses intended for LA-ICP-MS has resulted in a synthetic basaltic matrix series of glasses (USGS GS-series) and a natural basalt series of glasses (BCR-1G, BHVO-2G, and NKT-1G). These materials have been useful for the LA-ICP-MS community but were not originally intended for use by the electron or ion beam community. A material developed from start to finish with intended use in multiple microanalytical instruments would be useful for inter-laboratory and inter-instrument platform comparisons. This article summarizes the experiments undertaken to produce a basalt glass reference material suitable for distribution as a multiple-technique round robin material. The goal of the analytical work presented here is to demonstrate that the elemental homogeneity of the new glass is acceptable for its use as a reference material. Because the round robin exercise is still underway, only

  9. Reference Materials System: a framework for substitution analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bhagat, N K; Hoffman, K C

    1978-01-01

    A comprehensive systems approach to materials policy analysis, the Reference Materials System (RMS), has been developed and is described. The RMS provides a systematic approach to organizing diverse materials on all processes ranging from extraction of resources through their refinement, transportation, fabrication, installation, and maintenance at the point of end use, as well as recycling. This system can be used for the assessment of material technologies, substitutions and policies, and has been applied to assess the role of renewable materials as substitutes for energy intensive nonrenewables.

  10. Final recommendations for reference materials in black carbon analysis

    Science.gov (United States)

    Schmidt, Michael W. I.; Masiello, Caroline A.; Skjemstad, Jan O.

    Last summer, a symposium was held to discuss aspects of global biogeochemical cycles, including organic matter cycling in soils, rivers, and marine environments; black carbon particle fluxes and the biological pump; dissolved organic matter; and organic matter preservation. Seventy scientists from various disciplines, including oceanography, soil science, geology, and chemistry attended the 3-day meeting at the Friday Harbor Laboratories, a research station of the University of Washington.“New Approaches in Marine Organic Biogeochemistry” commemorated the life and science of a colleague and friend, John I. Hedges, who was also involved in several groups developing chemical reference materials. Part of this symposium included a workshop on chemical reference materials, where final recommendations of the Steering Committee for Black Carbon Reference Materials were presented.

  11. Commutability evaluation of reference materials of composition and properties of substances and materials

    Directory of Open Access Journals (Sweden)

    E. V. Osintseva

    2016-01-01

    Full Text Available The International Organization for Standardization laid down modern requirements for reference material producers (ISO 17034:2016, testing and calibration laboratories (ISO 15025:2005, stipulating the evaluation of reference material commutability in the course of their development (ISO Guide 35:2006 and use (ISO Guide 33:2006. The article deals with general issues of reference material commutability evaluation, the cases when the commutability evaluation is useful and the description of the approach, which may be used in the processing measurement results when evaluating the commutability of reference materials.

  12. A revised classification for direct tooth-colored restorative materials.

    Science.gov (United States)

    Mount, Graham J; Tyas, Martin J; Ferracane, Jack L; Nicholson, John W; Berg, Joel H; Simonsen, Richard J; Ngo, Hien C

    2009-09-01

    Composite resins and glass-ionomer cements were introduced to dentistry in the 1960s and 1970s, respectively. Since then, there has been a series of modifications to both materials as well as the development other groups claiming intermediate characteristics between the two. The result is a confusion of materials leading to selection problems. While both materials are tooth-colored, there is a considerable difference in their properties, and it is important that each is used in the appropriate situation. Composite resin materials are esthetic and now show acceptable physical strength and wear resistance. However, they are hydrophobic, and therefore more difficult to handle in the oral environment, and cannot support ion migration. Also, the problems of gaining long-term adhesion to dentin have yet to be overcome. On the other hand, glass ionomers are water-based and therefore have the potential for ion migration, both inward and outward from the restoration, leading to a number of advantages. However, they lack the physical properties required for use in load-bearing areas. A logical classification designed to differentiate the materials was first published by McLean et al in 1994, but in the last 15 years, both types of material have undergone further research and modification. This paper is designed to bring the classification up to date so that the operator can make a suitable, evidence-based, choice when selecting a material for any given situation.

  13. A Reference Guide for Cryogenic Properties of Materials

    Energy Technology Data Exchange (ETDEWEB)

    Weisend, John G

    2003-09-16

    A thorough knowledge of the behavior of materials at cryogenic temperatures is critical for the design of successful cryogenic systems. Over the past 50 years, a tremendous amount of material properties at cryogenic temperatures have been measured and published. This guide lists resources for finding these properties. It covers online databases, computer codes, conference proceedings, journals, handbooks, overviews and monographs. It includes references for finding reports issued by government laboratories and agencies. Most common solids and fluids used in cryogenics are covered.

  14. Production and characterization of a bovine liver candidate reference material

    Science.gov (United States)

    Bianchi, S. R.; Peixoto, A. M. J.; Souza, G. B.; Tullio, R. R.; Nogueira, A. R. A.

    2016-07-01

    The preparation of a bovine liver candidate reference material and the steps are taken to confirm its homogeneity, long and short term stabilities, and consensus values are described. Details of the sample preparation and the final collaborative exercise are presented. The material elemental composition was characterized by 17 elements (As, Ca, Cd, Co, Cu, Fe, K, Mg, Mo, Mn, Na, P, Pb, Se, Sr, V, and Zn) of nutritional and toxicological significance.

  15. Developing a matrix reference material for screening of transgenic rice.

    Science.gov (United States)

    Li, Jun; Wu, Yuhua; Li, Xiaofei; Wang, Yulei; Zhang, Li; Li, Yunjing; Wu, Gang

    2015-12-01

    Certified reference materials (CRMs) that are compatible with detection methods are needed to detect genetically modified organisms (GMOs). Screening is the first detection step in determining the possible presence of GMO ingredients in food or feed; however, screening has been hindered by the lack of GMO CRMs. In this study, transgenic rice materials were developed via the transformation of a construct harboring 11 commonly used screening elements. Digital PCR was utilized to identify a homozygous single-copy line termed SDrice. The qualitative detections of 11 elements in 21 transgenic materials demonstrated that the genomic DNA of the SDrice was suitable for use as a positive control in the screening of GMO ingredients. The suitability of SDrice as reference material was further checked by testing the sensitivity of 11 known conventional PCR assays, ranging from 10 to 50 copies of the SDrice genome. The standard curves that were created using SDrice DNA series as calibrators all exhibited good linearities in the relationships of the Ct values with the template copy numbers in these 11 real-time PCR assays. The LODs of the real-time PCR assays were estimated to be two to five copies of the SDrice genome. Comparisons of the SDrice with other GM rice revealed that significant differences existed in both the intercepts of the standard curves and the ΔCt values of the exogenous and reference genes for the P-35S, T-nos, HPT, T-35S, and Bar assays; the SDrice was not fit for quantification of other GM rice events. This study provided a matrix reference material (RM) that was suitable for screening GM rice, determination of sensitivity and a LOD of PCR assays, and overcame some of the drawbacks of plasmid DNA as reference material.

  16. MICROCRM: Feasibility certification studies of microbiological reference materials

    NARCIS (Netherlands)

    Mooijman KA; Nagelkerke NJD; Demarquilly C; Lemdani M; Stewardson D; Fouweather T; Lightfoot N; Simonart T; MGB

    2004-01-01

    In 2002 feasibility certification studies were carried out on three different types of microbiological reference materials for eight different ISO and EN standard methods, related to EU water legislation (Drinking-water Directive and Bathing-water Directive). These studies were performed as part of

  17. Overview of Uranium Isotopic Reference Materials at IRMM

    Science.gov (United States)

    Alonso-Munoz, A.; Richter, S.; Eykens, R.; Aregbe, Y.; Kuehn, H.; Verbruggen, A.

    2007-12-01

    For many applications in the geological sciences, in particular in geochemistry research, isotope ratio measurements play a significant role. For instance, in geochronology isotope abundances of uranium and its daughter products thorium and lead have been used since more than five decades to determine the age of various samples of geological interest. However, in order to validate mass spectrometric measurement procedures and to calibrate detector systems, suitable isotope reference materials are needed. IRMM is a well recognized provider for nuclear isotope reference materials to the nuclear industry and nuclear safeguards authorities, which can also be used for geological applications. This paper gives an overview of isotope reference materials for uranium prepared and certified at IRMM. These materials are synthetic isotope reference materials prepared based on proven methods of purifying and mixing highly enriched oxides. Firstly, a set of 10 mixtures of 233U, 235U and 238U was made in which the 235U/238U ratios were kept at 1:1 and the 233U/235U ratios varied from 1.0 to 10-6 (IRMM-072). This set is ideal for checking the linearity response of detectors used in isotope mass spectrometry. Recently, after the IRMM-072 series was exhausted, it has been replaced by the IRMM-073 and IRMM-074 series. Secondly the double spike IRMM-3636 with a 233U/236U ratio of 1:1 was prepared which allows internal mass fractionation correction for high precision 235U/238U ratio measurements. The 234U abundance of this double spike material is low enough to allow an accurate and precise correction of 234U/238U ratios, even for measurements of close to equilibrium uranium samples.

  18. Fluctuation Analyses for Pattern Classification in Nondestructive Materials Inspection

    Directory of Open Access Journals (Sweden)

    A. P. Vieira

    2010-01-01

    Full Text Available We review recent work on the application of fluctuation analyses of time series for pattern classification in nondestructive materials inspection. These analyses are based on the evaluation of time-series fluctuations across time intervals of increasing size, and were originally introduced in the study of fractals. A number of examples indicate that this approach yields relevant features allowing the successful classification of patterns such as (i microstructure signatures in cast irons, as probed by backscattered ultrasonic signals; (ii welding defects in metals, as probed by TOFD ultrasonic signals; (iii gear faults, based on vibration signals; (iv weld-transfer modes, as probed by voltage and current time series; (v microstructural composition in stainless steel, as probed by magnetic Barkhausen noise and magnetic flux signals.

  19. Recommended reference materials for realization of physicochemical properties density

    CERN Document Server

    Herington, E F G

    1976-01-01

    This book first presents the nomenclature and units used in the determination of densities of liquids and solids, followed by a general description of the apparatus and the methods used in the measurement of density, with particular reference to the pycnometric, hydrostatic weighing, magnetic float, and temperature flotation methods. The use of water as a density reference material is then explained, focusing on the isotopic composition of Standard Mean Ocean Water (SMOW) and the absolute density of SMOW as a function of temperature. Problems due to the effect of pressure and dissolved gases o

  20. Reference Materials for Reactor Neutron Fluence Rate and Temperature Measurements

    Science.gov (United States)

    Ingelbrecht, C.

    2003-06-01

    Certified reference materials are distributed by the European Commission through the BCR® programme (over 500 CRMs) including a series of activation and fission monitor materials originally proposed by the Euratom Working Group on Reactor Dosimetry. The current range (18 CRMs) includes materials to cover the complete energy spectrum, and suitable for different irradiation times. Fission monitors are 238UO2 or 237NpO2 in the form of microspheres. Activation monitors are high purity metals (Ni, Cu, Al, Fe, Nb, Rh, or Ti), certified for interfering trace impurities, or dilute aluminium-based alloys. Reference materials newly certified are IRMM-530R A1-0.1%Au, replacing the exhausted IRMM-530 material, used as comparator for k0- standardisation, and three new Al-Co alloys (0.01, 0.1 and 1.0%Co). Others in the process of certification are A1-0.1%Ag and A1-2%Sc for thermal and epithermal fluence rate measurements and two uranium-doped glass materials intended for dosimetry by the fission-track technique. Various alloy compositions have been prepared for use as melt-wire temperature monitors with melting points ranging from 198 to 327ºC.

  1. Lawrence Livermore National Laboratory Working Reference Material Production Pla

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Amy; Thronas, Denise; Marshall, Robert

    1998-11-04

    This Lawrence Livermore National Laboratory (LLNL) Working Reference Material Production Plan was written for LLNL by the Los Alamos National Laboratory to address key elements of producing seven Pu-diatomaceous earth NDA Working Reference Materials (WRMS). These WRMS contain low burnup Pu ranging in mass from 0.1 grams to 68 grams. The composite Pu mass of the seven WRMS was designed to approximate the maximum TRU allowable loading of 200 grams Pu. This document serves two purposes: first, it defines all the operations required to meet the LLNL Statement of Work quality objectives, and second, it provides a record of the production and certification of the WRMS. Guidance provided in ASTM Standard Guide C1128-89 was used to ensure that this Plan addressed all the required elements for producing and certifying Working Reference Materials. The Production Plan was written to provide a general description of the processes, steps, files, quality control, and certification measures that were taken to produce the WRMS. The Plan identifies the files where detailed procedures, data, quality control, and certification documentation and forms are retained. The Production Plan is organized into three parts: a) an initial section describing the preparation and characterization of the Pu02 and diatomaceous earth materials, b) middle sections describing the loading, encapsulation, and measurement on the encapsulated WRMS, and c) final sections describing the calculations of the Pu, Am, and alpha activity for the WRMS and the uncertainties associated with these quantities.

  2. Certified reference materials of trace elements in water

    Indian Academy of Sciences (India)

    A K Agrawal

    2005-07-01

    Measurement of trace elements is playing a vital role in industries and various sectors of science and technology including semiconductors, food, health and environmental sectors. In most of the cases a small error in measurement can vitiate all the measures taken for quality control and management. Many decisions regarding the suitability of material/products are based on the analysis. To reduce or eliminate the rejection rate of the products, accurate and reliable measurements are needed which can be achieved by the use of certified reference materials (CRMs). Their use in calibration of analytical equipments and validation of test methods ensures high quality in measurements and it provides traceability to the measurement data with national/international measurement systems (SI unit) also. In the present scenario of globalization of economy, use of certified reference materials (CRMs) in measurements is essential for global acceptance of products and test reports. Their use fulfil a mandatory requirement of international quality systems (ISO 9000, ISO/IEC standard 17025) including our national accreditation body, National Accreditation Board for Testing and Calibration Laboratories (NABL), World Trade Organization (WTO) etc. International manufacturers of CRMs are meeting most of the requirement of CRMs of the country. To meet the demand of CRMs indigenously, the National Physical Laboratory, India initiated a national programme on preparation and dissemination of certified reference materials.

  3. Developing Potential New Reference Materials for Light Isotopes in Foodstuffs

    Science.gov (United States)

    Frew, Russell; Van Hale, Robert; Clarke, Dianne; Abrahim, Aiman; Resch, Christian; Mayr, Leopold; Cannavan, Andrew; Gröning, Manfred

    2013-04-01

    Measurements of subtle variations in stable isotope ratios provide the means for verifying food integrity in numerous ways. Adulterants usually have different isotopic composition so their presence in a food is readily detectable. Stable isotope measurements can also be used to determine the region of production of the food. In most cases the ability of stable isotope measurements to verify, or otherwise reject, the authenticity of the food is greatly enhanced by comparison of a result to a reference database. The more high-quality data in the database, the more statistical power is afforded by the comparison. A serious weakness at present is the lack of reference materials in food matrices available to the community. Thus researchers have to rely on in-house standards for calibration and quality assurance. The result is that there are numerous datasets published that may be internally consistent but it is exceedingly difficult to combine these datasets into a cohesive database. This is particularly important for measurements of the hydrogen isotopes. Here we present a survey of the stable isotope (^2H, ^13C and ^15N) composition of 12 Reference Materials from the International Atomic Energy Agency catalogue. All but one of these materials are plant matter and have been developed as reference materials for other applications such as radionuclide or trace element measurements. Thus they have been verified as suitable materials in terms of stability and homogeneity for those tests. The purpose of this work is to ascertain if they are similarly suitable as stable isotope reference materials. The results from our survey show that there is a wide range in elemental and isotopic composition among these materials. For example, the ^15N values range from-13.5‰ to +18.6‰ and the nitrogen elemental composition range is from 0.7% to 9.7%. The ^13C values range from -20‰ to -40‰ and the carbon elemental composition ranges from 15% to 47%. We are now in the process of

  4. Updating Classifications of Ceramic Dental Materials: A Guide to Material Selection.

    Science.gov (United States)

    McLaren, Edward A; Figueira, Johan

    2015-06-01

    The indications for and composition of today's dental ceramic materials serve as the basis for determining the appropriate class of ceramics to use for a given case. By understanding the classifications, composition, and characteristics of the latest all-ceramic materials, which are presented in this article in order of most to least conservative, dentists and laboratory technicians can best determine the ideal material for a particular treatment.

  5. Primary certification of reference material for electrolytic conductivity of bioethanol

    Science.gov (United States)

    da Silva, L. F.; Gomes, M. R. F.; Cassini, G. C.; Faria, A. C. V.; Fraga, I. C. S.

    2016-07-01

    Nowadays the preservation of the planet is spreading into the international scene with the use of renewable energy sources such as bioethanol. The challenge is to guarantee the quality of produced bioethanol, and the electrolytic conductivity (EC) is one of the specified parameters for this purpose. However, is necessary to demonstrate the metrological traceability of the measurement results for EC in this matrix. This study presents the certification of a reference material for EC in bioethanol by using only primary measurements. The value of primary certified reference material (CRM) is (0.77 ± 0.06) µS.cm-1, and its use will provide the metrological traceability needed for measurement results in laboratories.

  6. New Filler Material for Reference Free Part Encapsulation Fixture

    Institute of Scientific and Technical Information of China (English)

    LI Bei-zhi; YANG Jian-guo; ZHOU Hu

    2002-01-01

    Reference free part encapsulation (RFPE) is a nontraditional universal fixturing technique. In this paper,new filler material-a lower melting point alloy for RFPE technique is introduced. Based on experiment, the shrinlkage and expansion rate, the effect of filler on workpiece drift and the effect of filler thickness on cutting distortion are studied. The alloy has a good mechanical and physical performance and the need of RFPE fixturing can be perfectly satisfied. The result shows that if the formula and process parameters of filler material are properly selected, it can obviously improve the quality of the workpiece, enhance the machining efficiency and reduce the manufacturing cost.

  7. Development and characterisation of a new line width reference material

    Science.gov (United States)

    Dai, Gaoliang; Zhu, Fan; Heidelmann, Markus; Fritz, Georg; Bayer, Thomas; Kalt, Samuel; Fluegge, Jens

    2015-11-01

    A new critical dimension (CD, often synonymously used for line width) reference material with improved vertical parallel sidewalls (IVPSs) has been developed and characterised. The sample has a size of 6 mm  ×  6 mm, consisting of 4 groups of 5  ×  5 feature patterns. Each feature pattern has a group of five reference line features with a nominal CD of 50 nm, 70 nm, 90 nm, 110 nm and 130 nm, respectively. Each feature pattern includes a pair of triangular alignment marks, applicable for precisely identifying the target measurement position, e.g. for comparison or calibration between different tools. The geometry of line features has been investigated thoroughly using a high-resolution transmission electron microscope and a CD atomic force microscope (CD-AFM). Their results indicate the high quality of the line features: the top corner radius of  strategy for the non-destructive calibration of the developed sample is introduced, which enables the application of the reference material in practice.

  8. Quality assurance of chemical ingredient classification for the National Drug File - Reference Terminology.

    Science.gov (United States)

    Zheng, Ling; Yumak, Hasan; Chen, Ling; Ochs, Christopher; Geller, James; Kapusnik-Uner, Joan; Perl, Yehoshua

    2017-09-01

    The National Drug File - Reference Terminology (NDF-RT) is a large and complex drug terminology consisting of several classification hierarchies on top of an extensive collection of drug concepts. These hierarchies provide important information about clinical drugs, e.g., their chemical ingredients, mechanisms of action, dosage form and physiological effects. Within NDF-RT such information is represented using tens of thousands of roles connecting drugs to classifications. In previous studies, we have introduced various kinds of Abstraction Networks to summarize the content and structure of terminologies in order to facilitate their visual comprehension, and support quality assurance of terminologies. However, these previous kinds of Abstraction Networks are not appropriate for summarizing the NDF-RT classification hierarchies, due to its unique structure. In this paper, we present the novel Ingredient Abstraction Network (IAbN) to summarize, visualize and support the audit of NDF-RT's Chemical Ingredients hierarchy and its associated drugs. A common theme in our quality assurance framework is to use characterizations of sets of concepts, revealed by the Abstraction Network structure, to capture concepts, the modeling of which is more complex than for other concepts. For the IAbN, we characterize drug ingredient concepts as more complex if they belong to IAbN groups with multiple parent groups. We show that such concepts have a statistically significantly higher rate of errors than a control sample and identify two especially common patterns of errors. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Characterization of Ricin and R. communis Agglutinin Reference Materials

    Directory of Open Access Journals (Sweden)

    Sylvia Worbs

    2015-11-01

    Full Text Available Ricinus communis intoxications have been known for centuries and were attributed to the toxic protein ricin. Due to its toxicity, availability, ease of preparation, and the lack of medical countermeasures, ricin attracted interest as a potential biological warfare agent. While different technologies for ricin analysis have been established, hardly any universally agreed-upon “gold standards” are available. Expert laboratories currently use differently purified in-house materials, making any comparison of accuracy and sensitivity of different methods nearly impossible. Technically challenging is the discrimination of ricin from R. communis agglutinin (RCA120, a less toxic but highly homologous protein also contained in R. communis. Here, we established both highly pure ricin and RCA120 reference materials which were extensively characterized by gel electrophoresis, liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI MS/MS, and matrix-assisted laser desorption ionization–time of flight approaches as well as immunological and functional techniques. Purity reached >97% for ricin and >99% for RCA120. Different isoforms of ricin and RCA120 were identified unambiguously and distinguished by LC-ESI MS/MS. In terms of function, a real-time cytotoxicity assay showed that ricin is approximately 300-fold more toxic than RCA120. The highly pure ricin and RCA120 reference materials were used to conduct an international proficiency test.

  10. TRENDS IN FIELD OF REFERENCE MATERIALS IN RUSSIA

    Directory of Open Access Journals (Sweden)

    E. V. Osintseva

    2015-01-01

    Full Text Available Trends in development of reference materials (RMs in Russia, in particular in the regulation and standardization, are described. As of December- 2015, Fifteen statutory and regulatory acts are valid in Russia in that field. The main principles of these acts to be harmonized with international requirements are discussed. Four interstate standards (for CIS country based on ISO Guide 30, ISO Guide 31, ISO Guide 34, ISO Guide 35 are developed and issued in 2016 to harmonize activities in the RMfield. The main trend in the national and interstate standardization in the RM field is the harmonization with international RM documents (OIML, ISO. In 2015 190 new approved pattern certified reference materials (CRMs of composition and properties of substances and materials were developed in Russia. The majority of new patterns of CRMs were developed for metallurgical, oil producing, refining and gas enterprises. Also CRM development for clinical diagnosis, pharmaceutics, ecological monitoring and production safety are still requested.. Development of CRMs based on the principles of private-state partnership is growing slowly.

  11. Characterization of Ricin and R. communis Agglutinin Reference Materials.

    Science.gov (United States)

    Worbs, Sylvia; Skiba, Martin; Söderström, Martin; Rapinoja, Marja-Leena; Zeleny, Reinhard; Russmann, Heiko; Schimmel, Heinz; Vanninen, Paula; Fredriksson, Sten-Åke; Dorner, Brigitte G

    2015-11-26

    Ricinus communis intoxications have been known for centuries and were attributed to the toxic protein ricin. Due to its toxicity, availability, ease of preparation, and the lack of medical countermeasures, ricin attracted interest as a potential biological warfare agent. While different technologies for ricin analysis have been established, hardly any universally agreed-upon "gold standards" are available. Expert laboratories currently use differently purified in-house materials, making any comparison of accuracy and sensitivity of different methods nearly impossible. Technically challenging is the discrimination of ricin from R. communis agglutinin (RCA120), a less toxic but highly homologous protein also contained in R. communis. Here, we established both highly pure ricin and RCA120 reference materials which were extensively characterized by gel electrophoresis, liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI MS/MS), and matrix-assisted laser desorption ionization-time of flight approaches as well as immunological and functional techniques. Purity reached >97% for ricin and >99% for RCA120. Different isoforms of ricin and RCA120 were identified unambiguously and distinguished by LC-ESI MS/MS. In terms of function, a real-time cytotoxicity assay showed that ricin is approximately 300-fold more toxic than RCA120. The highly pure ricin and RCA120 reference materials were used to conduct an international proficiency test.

  12. Agricultural biological reference materials for analytical quality control

    Energy Technology Data Exchange (ETDEWEB)

    Ihnat, M.

    1986-01-01

    Cooperative work is under way at Agriculture Canada, US Department of Agriculture, and US National Bureau of Standards in an attempt to fill some of the gaps in the world repertoire of reference materials and to provide much needed control materials for laboratories' day to day operations. This undertaking involves the preparation and characterization of a number of agricultural and food materials for data quality control for inorganic constituents. Parameters considered in the development of these materials were material selection based on importance in commerce and analysis; techniques of preparation, processing, and packaging; physical and chemical characterization; homogeneity testing and quantitation (certification). A large number of agricultural/food products have been selected to represent a wide range of not only levels of sought-for constituents (elements) but also a wide range of matrix components such as protein, carbohydrate, dietary fiber, fat, and ash. Elements whose concentrations are being certified cover some two dozen major, minor, and trace elements of nutritional, toxicological, and environmental significance.

  13. Certification of reference material of bacterial suspension turbidity

    Directory of Open Access Journals (Sweden)

    O. V. Fadeikina

    2014-01-01

    Full Text Available The article presents the results of research carried out FSBI "SCEMAP" of the Ministry of Health of the Russian Federation in order to bring qualification procedures for opacity standard samples of bacterial suspensions in line with current requirements for certified reference materials. The studies include: the justification requirements for the certification of opacity standard samples of bacterial suspensions, the development of the program and procedure of its evaluation, validation of the measurement procedure for the certified characteristics, statistical analysis of test results and calculation of metrological characteristics.

  14. Development studies of a new metronidazole certified reference material

    OpenAIRE

    Nogueira, Raquel; Rocha, Werickson Fortunato de Carvalho; Silva,Thaís Elias da; Rego, Eliane Cristina Pires do; Moreira, Gabriela Fernandes; Wollinger, Wagner; Caixeiro, Janaína Marques Rodrigues

    2012-01-01

    Este artigo apresenta os resultados dos estudos realizados com o candidato a material de referência certificado (MRC) de metronidazol, primeiro MRC deste fármaco disponibilizado no mercado e segundo MRC de fármacos brasileiro. Os estudos incluem a determinação dos teores de impurezas orgânicas, inorgânicas e voláteis, validação do método analítico de cromatografia líquida de alta eficiência (CLAE), estudos de estabilidade em condições de transporte e estocagem, estudo de homogeneidade, determ...

  15. Optimal Selection of Reference Set for the Nearest Neighbor Classification by Tabu Search

    Institute of Scientific and Technical Information of China (English)

    张鸿宾; 孙广煜

    2001-01-01

    In this paper, a new approach is presented to find the reference set for the nearest neighbor classifier. The optimal reference set, which has minimum sample size and satisfies a certain error rate threshold, is obtained through a Tabu search algorithm. When the error rate threshold is set to zero, the algorithm obtains a near minimal consistent subset of a given training set. While the threshold is set to a small appropriate value, the obtained reference set may compensate the bias of the nearest neighbor estimate. An aspiration criterion for Tabu search is introduced, which aims to prevent the search process from the inefficient wandering between the feasible and infeasible regions in the search space and speed up the convergence. Experimental results based on a number of typical data sets are presented and analyzed to illustrate the benefits of the proposed method. Compared to conventional methods, such as CNN and Dasarathy's algorithm, the size of the reduced reference sets is much smaller, and the nearest neighbor classification performance is better, especially when the error rate thresholds are set to appropriate nonzero values. The experimental results also illustrate that the MCS (minimal consistent set) of Dasarathy's algorithm is not minimal, and its candidate consistent set is not always ensured to reduce monotonically. A counter example is also given to confirm this claim.

  16. The new IAEA reference material: IAEA-434 technologically enhanced naturally occurring radioactive materials (TENORM) in phosphogypsum

    Energy Technology Data Exchange (ETDEWEB)

    Shakhashiro, A., E-mail: A.Shakhashiro@iaea.or [International Atomic Energy Agency, Agency' s Laboratories, Vienna International Center, PO Box 100, A-1400 Vienna (Austria); Sansone, U. [International Atomic Energy Agency, Agency' s Laboratories, Vienna International Center, PO Box 100, A-1400 Vienna (Austria); Wershofen, H. [Environmental Radioactivity, PTP, Braunschweig (Germany); Bollhoefer, A. [Environmental Radioactivity, Department of the Environment and Heritage, Darwin (Australia); Kim, C.K. [International Atomic Energy Agency, Agency' s Laboratories, Vienna International Center, PO Box 100, A-1400 Vienna (Austria); Kim, C.S. [Department of Environmental Radioactivity Assessment, Korea Institute of Nuclear Safety, Daejeon, Republic of Korea (Former collaborator) (Korea, Republic of); Kis-Benedek, G. [International Atomic Energy Agency, Agency' s Laboratories, Vienna International Center, PO Box 100, A-1400 Vienna (Austria); Korun, M. [Jozef Stefan Institute, Ljubljana (Slovenia); Moune, M. [LNE-LNHB, Laboratoire National Henri Becquerel, Gif-sur-Yvette Cedex (France); Lee, S.H. [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of); Tarjan, S. [Central Radiological Laboratory, Hungarian Agricultural Authority, Budapest (Hungary); Al-Masri, M.S. [Atomic Energy Commission of Syria, Damascus (Syrian Arab Republic)

    2011-01-15

    A reliable determination of Technologically Enhanced Naturally Occurring Radioactive Materials in phosphogypsum is necessary to comply with radiation protection and environmental regulations. In this respect, a new phosphogypsum reference material was produced and certified to assist in the validation of analytical methods and the quality assurance of produced analytical results. This paper presents the sample preparation methodology, material homogeneity assessment, characterization campaign results and assignment of property values, and associated uncertainties. The reference values and associated uncertainties for Pb-210, Ra-226, Th-230, U-234 and U-238 were established based on consensus values calculated from analytical results reported by three National Metrology Institutes and five expert laboratories.

  17. The new IAEA reference material: IAEA-434 technologically enhanced naturally occurring radioactive materials (TENORM) in phosphogypsum.

    Science.gov (United States)

    Shakhashiro, A; Sansone, U; Wershofen, H; Bollhöfer, A; Kim, C K; Kim, C S; Kis-Benedek, G; Korun, M; Moune, M; Lee, S H; Tarjan, S; Al-Masri, M S

    2011-01-01

    A reliable determination of Technologically Enhanced Naturally Occurring Radioactive Materials in phosphogypsum is necessary to comply with radiation protection and environmental regulations. In this respect, a new phosphogypsum reference material was produced and certified to assist in the validation of analytical methods and the quality assurance of produced analytical results. This paper presents the sample preparation methodology, material homogeneity assessment, characterization campaign results and assignment of property values, and associated uncertainties. The reference values and associated uncertainties for Pb-210, Ra-226, Th-230, U-234 and U-238 were established based on consensus values calculated from analytical results reported by three National Metrology Institutes and five expert laboratories.

  18. Phase classification by mean shift clustering of multispectral materials images.

    Science.gov (United States)

    Martins, Diego Schmaedech; Josa, Victor M Galván; Castellano, Gustavo; da Costa, José A T Borges

    2013-10-01

    A mean-shift clustering (MSC) algorithm is introduced as a valuable alternative to perform materials phase classification from multispectral images. As opposed to other multivariate statistical techniques, such as factor analysis or principal component analysis (PCA), clustering techniques directly assign a class label to each pixel, so that their outputs are phase segmented images, i.e., there is no need for an additional segmentation algorithm. On the other hand, as compared to other clustering procedures and classification methods, such as segmentation by thresholding of multiple spectral components, MSC has the advantages of not requiring previous knowledge of the number of data clusters and not assuming any shape for these clusters, i.e., neither the number nor the composition of the phases must be previously known. This makes MSC a particularly useful tool for exploratory research, assisting phase identification of unknown samples. Visualization and interpretation of the results are also simplified, since the information content of the output image does not depend on the particular choice of the content of the color channels.We applied MSC to the analysis of two sets of X-ray maps acquired in scanning electron microscopes equipped with energy-dispersive detection systems. Our results indicate that MSC is capable of detecting additional phases, not clearly identified through PCA or multiple thresholding, with a very low empirical reject rate.

  19. Stable isotope reference materials at the IAEA - the latest developments.

    Science.gov (United States)

    Assonov, Sergey; Gröning, Manfred; Fajgelj, Ales

    2017-04-01

    During the last few years the IAEA has performed works in several directions as following: • Released IAEA-603 (replacement of NBS19) - this is primary Stable isotope Reference Material (RM) used for the VPDB 13C and 18O scale realisation, • Released 6 isotopically enriched (in 2H and 18O) waters, • Performed careful monitoring of LVEC' property delta-13C value. This resulted in understanding that LSVEC needs a replacement. • Taken part in characterisation of 18 new organic CRMs (together with Indiana University and USGS) • Creating collaborations with metrology institutes - focus on metrological aspects of RMs, • As a spin-off of the Technical Meeting on Stable Isotope Reference Materials (IAEA, Vienna 2014) the European EMPIR project aimed to create infrastructure to produce gas mixtures characterised in CO2 isotope composition has been established (NPL, UK and other metrological institutes). The presentation will give details of these works and overview of the current status of RMs production and development.

  20. Prescribing during pregnancy and lactation with reference to the Swedish classification system

    DEFF Research Database (Denmark)

    Olesen, Charlotte; Sørensen, Henrik Toft; Berg, Lolkje de Jong-van den

    1999-01-01

    AIM: To assess the current prescribing pattern for 15,756 primiparae before, during, and after their pregnancies with reference to fetal and neonatal risk. METHOD: A prescription database study with linkage to The Danish Medical Birth Registry from 1991 to 1996. The drug subsidy system in Danish...... retail pharmacies, made it possible to identify prescriptions by individual use. All 34,334 prescriptions were set against the Swedish classification of risk of drug use in pregnancy and lactation. RESULTS: During pregnancy, safe (group A), potentially harmful (group B3, C, and D), and non......-classifiable drugs accounted for 40.9%, 26.6% and 28.7% respectively. The proportion of women who redeemed drugs was 29.2%, 8.6%, 18.7% and 0.9% from drug groups A, B, C and D respectively. The proportion of prescriptions from high risk groups declined during the course of pregnancy. Postpartum, safe drugs (group I...

  1. INAA Application for Trace Element Determination in Biological Reference Material

    Science.gov (United States)

    Atmodjo, D. P. D.; Kurniawati, S.; Lestiani, D. D.; Adventini, N.

    2017-06-01

    Trace element determination in biological samples is often used in the study of health and toxicology. Determination change to its essentiality and toxicity of trace element require an accurate determination method, which implies that a good Quality Control (QC) procedure should be performed. In this study, QC for trace element determination in biological samples was applied by analyzing the Standard Reference Material (SRM) Bovine muscle 8414 NIST using Instrumental Neutron Activation Analysis (INAA). Three selected trace element such as Fe, Zn, and Se were determined. Accuracy of the elements showed as %recovery and precision as %coefficient of variance (%CV). The result showed that %recovery of Fe, Zn, and Se were in the range between 99.4-107%, 92.7-103%, and 91.9-112%, respectively, whereas %CV were 2.92, 3.70, and 5.37%, respectively. These results showed that INAA method is precise and accurate for trace element determination in biological matrices.

  2. Bias detection and certified reference materials for random measurands

    Science.gov (United States)

    Rukhin, Andrew L.

    2015-12-01

    A problem that frequently occurs in metrology is the bias checking of data obtained by a laboratory against the specified value and uncertainty estimate given in the certificate of analysis. The measurand—a property of a certified reference material (CRM)—is supposed to be random with a normal distribution whose parameters are given by the certificate specifications. The laboratory’s data from subsequent measurements of the CRM (a CRM experiment) are summarized by the sample mean value and its uncertainty which is commonly based on a repeatability standard deviation. New confidence intervals for the lab’s bias are derived. Although they may lack intuitive appeal, those obtained by using higher order asymptotic methods, compared and contrasted in this paper, are recommended.

  3. Certified reference material to water content determination in bioethanol fuel

    Directory of Open Access Journals (Sweden)

    Janaína M. Rodrigues

    2012-01-01

    Full Text Available Bioethanol is a strategic biofuel in Brazil. Thus, a strong metrological basis for its measurements is required to ensure the quality and promote its exportation. Recently, Inmetro certified a reference material for water content in bioethanol. This paper presents the results of these studies. The characterization, homogeneity, short-term stability and long-term stability uncertainty contributions values were 0.00500, 0.0166, 0.0355 and 0.0391 mg g-1, respectively. The certificated value for water content of bioethanol fuel was (3.65 ± 0.11 mg g-1. This CRM is the first and up to now the unique in the world.

  4. Production of Working Reference Materials for the Capability Evaluation Project

    Energy Technology Data Exchange (ETDEWEB)

    Phillip D. Noll, Jr.; Robert S. Marshall

    1999-03-01

    Nondestructive waste assay (NDA) methods are employed to determine the mass and activity of waste-entrained radionuclides as part of the National TRU (Trans-Uranic) Waste Characterization Program. In support of this program the Idaho National Engineering and Environmental Laboratory Mixed Waste Focus Area developed a plan to acquire capability/performance data on systems proposed for NDA purposes. The Capability Evaluation Project (CEP) was designed to evaluate the NDA systems of commercial contractors by subjecting all participants to identical tests involving 55 gallon drum surrogates containing known quantities and distributions of radioactive materials in the form of sealed-source standards, referred to as working reference materials (WRMs). Although numerous Pu WRMs already exist, the CEP WRM set allows for the evaluation of the capability and performance of systems with respect to waste types/configurations which contain increased amounts of {sup 241}Am relative to weapons grade Pu, waste that is dominantly {sup 241}Am, as well as wastes containing various proportions of depleted uranium. The CEP WRMs consist of a special mixture of PuO{sub 2}/AmO{sub 2} (IAP) and diatomaceous earth (DE) or depleted uranium (DU) oxide and DE and were fabricated at Los Alamos National Laboratory. The IAP WRMS are contained inside a pair of welded inner and outer stainless steel containers. The DU WRMs are singly contained within a stainless steel container equivalent to the outer container of the IAP standards. This report gives a general overview and discussion relating to the production and certification of the CEP WRMs.

  5. Reference materials and interlaboratory comparison for actinide analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hanssens, Alain; Viallesoubranne, Carole; Roche, Claude; Liozon, Gerard [Commissariat a l' Energie Atomique, Marcoule: BP 17171, 30207 Bagnols sur Ceze (France)

    2008-07-01

    Measurement quality is crucial for the safety of nuclear facilities and is a primary requirement for fissile material monitoring and accountancy. CETAMA (Cea Committee for the establishment of analysis methods), in collaboration with Cea and AREVA laboratories, fabricates certified reference materials and organizes interlaboratory comparison programs for plutonium and uranium assay in solution. A new plutonium metal measurement standard (MP3) is currently being prepared by Cea and is a subject of cooperative work in view of its certification and use by analysis laboratories. U and Pu interlaboratory comparisons are carried out at regular intervals on benchmark samples in coordination with working groups from French nuclear laboratories. These programs are supported by international cooperation. 'Chemical' methods (potentiometry, gravimetric analysis, etc.) generally provide the best accuracy. Coulometry is the benchmark technique for plutonium assay: its metrological qualities should be an incentive for wider use by laboratories performing precise control assays of plutonium as well as uranium. Gravimetric analysis provides excellent results for analysis of pure uranyl nitrate solutions. In view of its many advantages we encourage laboratories to employ this technique to assay pure U or Pu solutions. 'Physical' or 'physicochemical' methods are increasingly used, and their performance has improved. K-edge absorption spectrometry and isotope dilution mass spectrometry are capable of reaching measurement quality levels comparable to those of the best 'chemical' methods. (authors)

  6. Pigment production by Bacteroides species with reference to sub-classification.

    Science.gov (United States)

    Duerden, B I

    1975-02-01

    All six reference strains of Bacteroides species, 36 laboratory isolates conforming to this group, and individual strains of Escherichia coli, Proteus mirabilis, Salmonella typhimurium and Clostridum welchii produced a dense black pigment, identified as ferrus sulphide, when grown in cooked-meat media containing cystine and ferrous sulphate. This was an indicator effect resulting from the production of H2S by the bacteria in the presence of ferrous ions and was unrelated to the characteristic pigment produced by strains of B. melaninogenicus when grown on blood agar. A pigment was extracted by ultrasonic disintegration of washed cells of three reference strains of B. melanino-genicus grown for 1 week in horse-blood broth and on human-blood agar. It was intracellular or cell-associated, soluble in water and had the spectrophotometric characteristics of a derivative of haemoglobin. No such pigment was extracted from strains of B. fragilis or B. necrophorus by similar procedures. Pigment production is a stable characteristic of those strains of Bacteroides called B. melaninogenicus and it is a significant property in the classification of the Bacteroides group. However, the pigment-producing strains are not a homogenous species, and there were considerable differences between the results of biochemical tests and antibograms obtained with the three strains of B. melaninogenicus.

  7. 40 CFR 1068.95 - What materials does this part reference?

    Science.gov (United States)

    2010-07-01

    ... material from the Society of Automotive Engineers that we have incorporated by reference. The first column... reference it. Anyone may purchase copies of these materials from the Society of Automotive Engineers,...

  8. Reference Materials: Critical Importance to the Infant Formula Industry.

    Science.gov (United States)

    Wargo, Wayne F

    2017-09-01

    Infant formula is one of the most regulated foods in the world. It has advanced in complexity over the years as a result of numerous research innovations. To ensure product safety and quality, analytical technologies have also had to advance to keep pace. Given the rigorous performance demands expected of these methods and the ever-growing array of complex matrixes, there is the potential for gaps to exist in current Official MethodsSM and other recognized international methods for infant formula and adult nutritionals. Food safety concerns, particularly for infants, drive the need for extensive testing by manufacturers and regulators. The net effect is the potential for an increase in time- and resource-consuming regulatory disputes. In an effort to mitigate such costly activities, AOAC INTERNATIONAL, under the direction of the Infant Formula Council of America-a trade association of manufacturers and marketers of formulated nutritional products-agreed to establish voluntary consensus Standard Method Performance Requirements, and, ultimately, to identify and publish globally recognized, fit-for-purpose standard methods. To accomplish this task, nutritional reference materials (RMs), representing all major commercially available nutritional formulations, were (and continue to be) a critical necessity. In this paper, various types of RMs will be defined, followed by review and discussion of their importance to the infant formula industry.

  9. Reference material manufacture and certification for the AVNG

    Energy Technology Data Exchange (ETDEWEB)

    Hauck, Danielle K [Los Alamos National Laboratory; Mac Arthur, Duncan [Los Alamos National Laboratory; Thron, Jonathan L [Los Alamos National Laboratory; Livke, Alexander [VNIIEF; Kondratov, Sergey [VNIIEF; Razinkov, Sergey [VNIIEF

    2010-01-01

    Testing and demonstration of any radiation measurement system requires the use of appropriate radioactive sources. The AVNG implementation that we describe is an attribute measurement system built by RFNC - VNIIEF in Sarov, Russia. The AVNG detects neutron and gamma radiation signatures and displays the three unclassified attributes of 'plutonium presence,' 'plutonium mass > 2 kg,' and 'plutonium isotopic ratio ({sup 240}Pu to {sup 239}Pu) < 0.1.' The AVNG was tested using a number of reference material (RM) sources with masses and isotopic ratios above and below these thresholds. The AVNG was demonstrated in June 2009 using several of these sources in addition to detector calibration sources. Since the AVNG was designed to measure multi-kg plutonium sources, the RM was manufactured specifically for use with this system. In addition, the RM was used to test the thresholds in the AVNG, so the size and composition of each RM was certified prior to use. In this presentation, we will describe the various steps in the manufacture and certification of these RM sources.

  10. Development of working reference materials for clinical virology.

    Science.gov (United States)

    Fryer, Jacqueline F; Baylis, Sally A; Gottlieb, Anna L; Ferguson, Morag; Vincini, Giuseppe A; Bevan, Valerie M; Carman, William F; Minor, Philip D

    2008-12-01

    Nucleic acid amplification technique (NAT)-based assays are replacing traditional diagnostic methods in clinical laboratories. However, many of these assays are developed in-house and the lack of standardised reference materials has hindered assay implementation and control. Consequently, in the UK, the Clinical Virology Network (CVN), the National Institute for Biological Standards and Control (NIBSC), and the Health Protection Agency (HPA), are working in collaboration to develop working standards or 'run controls' for diagnostic NAT-based assays, particularly real-time PCR. These run controls are intended for use in microbiology laboratories and are designed to be extracted and amplified in the same way as clinical samples and included in each assay run. The aim is to enable clinical laboratories to continuously monitor the performance of their diagnostic NAT assays on a run-by-run basis allowing inter-laboratory comparisons, and ultimately improving the consistency of results. At present, eight candidate run controls representing clinically relevant viral targets have been prepared for evaluation by CVN laboratories. Data have been returned on the performance of each run control in routine diagnostic assays. Preliminary results presented here indicate a high level of variability in intra- and inter-assay detection of these targets, highlighting the need for standardisation of assays within molecular diagnostics.

  11. LA-ICP-MS of magnetite: Methods and reference materials

    Science.gov (United States)

    Nadoll, P.; Koenig, A.E.

    2011-01-01

    Magnetite (Fe3O4) is a common accessory mineral in many geologic settings. Its variable geochemistry makes it a powerful petrogenetic indicator. Electron microprobe (EMPA) analyses are commonly used to examine major and minor element contents in magnetite. Laser ablation ICP-MS (LA-ICP-MS) is applicable to trace element analyses of magnetite but has not been widely employed to examine compositional variations. We tested the applicability of the NIST SRM 610, the USGS GSE-1G, and the NIST SRM 2782 reference materials (RMs) as external standards and developed a reliable method for LA-ICP-MS analysis of magnetite. LA-ICP-MS analyses were carried out on well characterized magnetite samples with a 193 nm, Excimer, ArF LA system. Although matrix-matched RMs are sometimes important for calibration and normalization of LA-ICP-MS data, we demonstrate that glass RMs can produce accurate results for LA-ICP-MS analyses of magnetite. Cross-comparison between the NIST SRM 610 and USGS GSE-1G indicates good agreement for magnetite minor and trace element data calibrated with either of these RMs. Many elements show a sufficiently good match between the LA-ICP-MS and the EMPA data; for example, Ti and V show a close to linear relationship with correlation coefficients, R2 of 0.79 and 0.85 respectively. ?? 2011 The Royal Society of Chemistry.

  12. [Classification of Colombian children with malnutrition according to NCHS reference or WHO standard].

    Science.gov (United States)

    Velásquez, Claudia; Bermúdez, Juliana; Echeverri, Claudia; Estrada, Alejandro

    2011-12-01

    A descriptive study was conducted to evaluate the concordance of National Center for Health Statistics reference (NCHS) used to classify undernourished children from Colombia with the WHO Child Growth Standards. We used data from children aged 6 to 59 months with acute malnutrition (Z Infantil" nutrition program in Colombia. Indicators height-for-age, weight for-height were analyzed when they were admitted to the hospital and weight for-height leaving the hospital. A statistical method used to compare means was T-student. Correlation coefficient intraclass (CCI) and Kappa index evaluated the concordance between NCHS and OMS; McNemar method evaluated the changes on the nutritional classification for children according to growth devices used. Of the total number of children classified as normal by NCHS, 10.4% were classified as stunted by WHO. 64% of the children admitted to the hospital presented acute malnutrition according to NCHS, of these 44,8% presented severe emaciation according to OMS, indeed severe emaciation increased of 36,0% to 63,3% using OMS. 5% of children leaving the hospital could need to stay more days if they had been evaluated with OMS. Growth devices shown high concordance in height-for-age (CCI = 0,988; k= 0,866) and weight for-height (CCI = 0,901; k = 0,578). Concluded that OMS growth standards classified more malnourished children and more severe states, in addition more malnourished children could be hospitalized and they could stay more days.

  13. Molecular phylogeny and revised classification of the haplotilapiine cichlid fishes formerly referred to as "Tilapia".

    Science.gov (United States)

    Dunz, Andreas R; Schliewen, Ulrich K

    2013-07-01

    African cichlids formerly referred to as "Tilapia" represent a paraphyletic species assemblage belonging to the so called haplotilapiine lineage which gave rise to the spectacular East African cichlid radiations (EARs) as well as to globally important aquaculture species. We present a comprehensive molecular phylogeny of representative haplotilapiine cichlids, combining in one data set four mitochondrial and five nuclear loci for 76 species, and compare it with phylogenetic information of a second data set of 378 mitochondrial ND2 haplotypes representing almost all important "Tilapia" or Tilapia-related lineages as well as most EAR lineages. The monophyly of haplotilapiines is supported, as is the nested sister group relationship of Etia and mouthbrooding tilapiines with the remaining haplotilapiines. The latter are consistently placed in eight monophyletic clades over all datasets and analyses, but several dichotomous phylogenetic relationships appear compromised by cytonuclear discordant phylogenetic signal. Based on these results as well as on extensive morphological evidence we propose a novel generic and suprageneric classification including a (re-)diagnosis of 20 haplotilapiine cichlid genera and nine tribes. New tribes are provided for the former subgenera Coptodon Gervais, 1853, HeterotilapiaRegan, 1920 and PelmatolapiaThys van den Audenaerde, 1969, in addition for "Tilapia" joka, Tilapia sensu stricto and Chilochromis, Etia, Steatocranus sensu stricto, the mouthbrooding tilapiines and for a clade of West African tilapiines.

  14. Dioxins in Food and Feed - Reference Methods and New Certified Reference Materials (DIFFERENCE)

    NARCIS (Netherlands)

    Leeuwen, van S.P.J.; Goeyens, L.; Loco, van J.; Carbonelle, S.; Overmeire, van I.; Beernaert, H.; Cleuvenbergen, van R.; Schoeters, G.; Bjoerklund, E.; Sporring, S.; Abalos, M.; Abad, E.; Rivera, J.; Santos, J.; Traag, W.A.; Hoogenboom, R.; Haglund, P.; Wiberg, K.; Holst, von C.; Maquet, A.; Pasini, A.L.; Fraise, D.; Becher, G.; Korytar, P.; Leonards, P.E.G.; Boer, de J.

    2005-01-01

    The European research project DIFFERENCE (“Dioxins in Food and Feed – Reference methods and New Certified Reference Materials”) was focussed on the development of an alternative methods for analysis of polychlorinated dibenzodioxins (PCDDs), dibenzofurans (PCDFs) and dioxin-like polychlorinated

  15. 10 CFR 431.443 - Materials incorporated by reference.

    Science.gov (United States)

    2010-01-01

    ... reference. (a) General. The Department incorporates by reference the following standards into Subpart X of... Test Methods for Single- and Three-Phase Small Motors, IBR approved for § 431.444. (2) (c) IEEE...-1331, 1-800-678-IEEE (4333), or go to http://www.ieee.org/web/publications/home/index.html. (1)...

  16. Reference Materials in LIS Instruction: A Delphi Study

    Science.gov (United States)

    Rabina, Debbie

    2013-01-01

    This paper presents the results of a Delphi study conducted over a two-month period in 2011. The purpose of the study was to identify reference sources that should be covered in basic reference courses taught in LIS programs in the United States. The Delphi method was selected for its appropriateness in soliciting expert opinions and assessing the…

  17. [Study of reference material for excitation spectrum wavelength calibration of fluorescence spectrophotometer].

    Science.gov (United States)

    Chen, Xiao-bo; Kang, Dong-guo; Zhao, Cheng-yi; Li, Song; Wu, Zheng-long; Ma, Hui; Liu, Zhong-min; Zheng, Zhe

    2005-07-01

    A reference material used for wavelength calibration of fluorescence spectrophotometer was found. The holmium doped oxide reference material GBW(E) 130112 is a kind of standard reference material for absorption spectrophotometer. It can emit 547.7 nm fluorescence when excited by xenon lamp light. The excitation spectrum of 547.7 nm fluorescence was measured. It was found that the measured peaks of excitation spectrum are positioned at 333.56, 360.43 and 418.39 nm, respectively, which are coincident with the true values 333.8, 360.9 and 418.5 nm of reference material certification. It was illustrated that the holmium doped oxide reference material GBW(E)130112 could be used as reference material for the excitation wavelength calibration of the fluorescence spectrophotometer. Its property could be enhanced very much if high luminescent efficiency material is selected as rare earth ion doped matrix, and the purity is enhanced to reduce the cross relaxation.

  18. REFERENCE MATERIALS SYSTEM OF SCIENTIFIC METHODICAL CENTRE OF STATE SERVICE OF REFERENCE MATERIALS FOR COMPOSITION AND PROPERTIES OF SUBSTANCES AND MATERIALS URAL RESEARCH INSTITUTE FOR METROLOGY

    Directory of Open Access Journals (Sweden)

    E. V. Osinseva

    2015-01-01

    Full Text Available Since 1960s UNIIM performs research in the field of needs in reference materials of composition and properties of substances and materials (RM as well as develops it. During the research UNIIM has developed 757 types of RMs for metrological measurement assurance of factors of composition and properties of substance and materials for test laboratories of chemical, pharmaceutical, fuel, food industry, agriculture, metallurgy and ecological monitoring laboratories. List ofRMs enlarges thanks to development of UNIIM standards and transmission measurement facility from State standards of units. Taking into account the actual requirements in the field of measurements, the UNIIM's key destination is to assure the accuracy and the metrological traceability of measurements. The present-day system of RMs to be developed in UNIIM includes RMs of composition of inorganic and organic compounds and their solutions, fuels, stable isotopic materials, water, grounds, food products, biomaterials, nanomaterials, metals, alloys and other materials offerrous and non-ferrous industry, RMs of properties (thermodynamic, magnetic, physical-chemical, technical of substances and materials. The present article considers history of RMs list development which were created by UNIIM and the strategy of this direction.

  19. 10 CFR 431.133 - Materials incorporated by reference.

    Science.gov (United States)

    2010-01-01

    ...-Conditioning and Refrigeration Institute (ARI) Standard 810-2003, “Performance Rating of Automatic Commercial..., Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 29-1988 (RA 2005), “Methods of Testing Automatic... incorporated by reference are available for inspection at: (i) National Archives and Records...

  20. Recommended reference materials for realization of physicochemical properties pressure-volume-temperature relationships

    CERN Document Server

    Herington, E F G

    1977-01-01

    Recommended Reference Materials for Realization of Physicochemical Properties presents recommendations of reference materials for use in measurements involving physicochemical properties, namely, vapor pressure; liquid-vapor critical temperature and critical pressure; orthobaric volumes of liquid and vapor; pressure-volume-temperature properties of the unsaturated vapor or gas; and pressure-volume-temperature properties of the compressed liquid. This monograph focuses on reference materials for vapor pressures at temperatures up to 770 K, as well as critical temperatures and critical pressures

  1. Intestinal permeability study of minoxidil: assessment of minoxidil as a high permeability reference drug for biopharmaceutics classification.

    Science.gov (United States)

    Ozawa, Makoto; Tsume, Yasuhiro; Zur, Moran; Dahan, Arik; Amidon, Gordon L

    2015-01-05

    The purpose of this study was to evaluate minoxidil as a high permeability reference drug for Biopharmaceutics Classification System (BCS). The permeability of minoxidil was determined in in situ intestinal perfusion studies in rodents and permeability studies across Caco-2 cell monolayers. The permeability of minoxidil was compared with that of metoprolol, an FDA reference drug for BCS classification. In rat perfusion studies, the permeability of minoxidil was somewhat higher than that of metoprolol in the jejunum, while minoxidil showed lower permeability than metoprolol in the ileum. The permeability of minoxidil was independent of intestinal segment, while the permeability of metoprolol was region-dependent. Similarly, in mouse perfusion study, the jejunal permeability of minoxidil was 2.5-fold higher than that of metoprolol. Minoxidil and metoprolol showed similar permeability in Caco-2 study at apical pH of 6.5 and basolateral pH of 7.4. The permeability of minoxidil was independent of pH, while metoprolol showed pH-dependent transport in Caco-2 study. Minoxidil exhibited similar permeability in the absorptive direction (AP-BL) in comparison with secretory direction (BL-AP), while metoprolol had higher efflux ratio (ER > 2) at apical pH of 6.5 and basolateral pH of 7.4. No concentration-dependent transport was observed for either minoxidil or metoprolol transport in Caco-2 study. Verapamil did not alter the transport of either compounds across Caco-2 cell monolayers. The permeability of minoxidil was independent of both pH and intestinal segment in intestinal perfusion studies and Caco-2 studies. Caco-2 studies also showed no involvement of carrier mediated transport in the absorption process of minoxidil. These results suggest that minoxidil may be an acceptable reference drug for BCS high permeability classification. However, minoxidil exhibited higher jejunal permeability than metoprolol and thus to use minoxidil as a reference drug would raise the

  2. USGS Reference Materials Program: Serving the Needs of the Global Analytical Community

    Science.gov (United States)

    Wolf, Ruth E.; Wilson, Stephen A.

    2007-01-01

    Every year in the United States, millions of measurements are made on the chemical composition of items that affect us on a daily basis. The accuracy of these measurements is routinely determined by the analysis of appropriate reference materials. In the field of earth science, reference materials are particularly important because they help us develop a better understanding of the processes that have shaped, and continue to shape the world around us. USGS reference materials are distributed internationally to organizations involved in geochemical and environmental analysis, instrumentation and methods development, and industrial research and quality assurance. Reference materials are widely used in the development and validation of geochemical models used by the USGS.

  3. Classification

    Science.gov (United States)

    Clary, Renee; Wandersee, James

    2013-01-01

    In this article, Renee Clary and James Wandersee describe the beginnings of "Classification," which lies at the very heart of science and depends upon pattern recognition. Clary and Wandersee approach patterns by first telling the story of the "Linnaean classification system," introduced by Carl Linnacus (1707-1778), who is…

  4. Standard Reference Development of nuclear material for Tensile and Hardness Test Properties

    Energy Technology Data Exchange (ETDEWEB)

    Choo, Y. S.; Kim, D. S.; Yoo, B. O.; Ahn, S. B.; Baik, S. J.; Chun, Y. B.; Kim, K. H.; Hong, K. P.; Ryu, W. S

    2007-12-15

    Standard reference is a official approved data such a coefficient of physics, approved material properties, and etc., which should be analyzed and evaluated by scientific method to acquire official approval for accuracy and credibility of measured data and information. So it could be used broadly and continuously by various fields of nation and society. It is classified to effective standard reference, verified standard reference, and certified standard reference. There are sixteen fields in designated standard references such a physical chemistry field, material field, metal field, and the others. The standard reference of neutron irradiated nuclear structural material is classified to metal field. This report summarized the whole processes about data collection, data production, data evaluation and the suggestion of details evaluation technical standard for tensile and hardness properties, which were achieved by carry out the project 'nuclear material standard reference development' as a result.

  5. delta 15N and non-carbonate delta 13C values for two petroleum source rock reference materials and a marine sediment reference material

    Science.gov (United States)

    Dennen, Kristin O.; Johnson, Craig A.; Otter, Marshall L.; Silva, Steven R.; Wandless, Gregory A.

    2006-01-01

    Samples of United States Geological Survey (USGS) Certified Reference Materials USGS Devonian Ohio Shale (SDO-1), and USGS Eocene Green River Shale (SGR-1), and National Research Council Canada (NRCC) Certified Marine Sediment Reference Material (PACS-2), were sent for analysis to four separate analytical laboratories as blind controls for organic rich sedimentary rock samples being analyzed from the Red Dog mine area in Alaska. The samples were analyzed for stable isotopes of carbon (delta13Cncc) and nitrogen (delta15N), percent non-carbonate carbon (Wt % Cncc) and percent nitrogen (Wt % N). SDO-1, collected from the Huron Member of the Ohio Shale, near Morehead, Kentucky, and SGR-1, collected from the Mahogany zone of the Green River Formation are petroleum source rocks used as reference materials for chemical analyses of sedimentary rocks. PACS-2 is modern marine sediment collected from the Esquimalt, British Columbia harbor. The results presented in this study are, with the exceptions noted below, the first published for these reference materials. There are published information values for the elemental concentrations of 'organic' carbon (Wt % Corg measured range is 8.98 - 10.4) and nitrogen (Wt % Ntot 0.347 with SD 0.043) only for SDO-1. The suggested values presented here should be considered 'information values' as defined by the NRCC Institute for National Measurement Reference Materials and should be useful for the analysis of 13C, 15N, C and N in organic material in sedimentary rocks.

  6. Alternative buffer material. Status of the ongoing laboratory investigation of reference materials and test package 1

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, Daniel [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Dueck, Ann; Nilsson, Ulf; Olsson, Siv; Sanden, Torbjoern [Clay Technology AB, Lund (Sweden); Lydmark, Sara; Jaegerwall, Sara; Pedersen, Karsten [Microbial Analytics Sweden AB, Moelnlycke (Sweden); Hansen, Staffan [LTH Lund Univ., Lund (Sweden)

    2011-07-15

    Bentonite clay is part of the Swedish KBS-3 design of final repositories for high level radioactive waste. Wyoming bentonite with the commercial name MX-80 (American Colloid Co) has long been the reference for buffer material in the KBS-3 concept. Extending the knowledge base of alternative buffer materials will make it possible to optimize regarding safety, availability and cost. For this reason the field experiment Alternative Buffer Material (ABM) was started at Aespoe Hard Rock Laboratory during 2006. The experiment includes three medium-scale test packages, each consisting of a central steel tube with heaters, and a buffer of compacted clay. Eleven different clays were chosen for the buffers to examine effects of smectite content, interlayer cations and overall iron content. Also bentonite pellets with and without additional quartz are being tested. The buffer in package 1 had been subjected to wetting by formation water and heating for more than two years (at 130 deg C for {approx} 1 year) when it was retrieved and analyzed. The main purposes of the project were to characterise the clays with respect to hydro-mechanical properties, mineralogy and chemical composition and to identify any differences in behaviour or long term stability. The diversity of clays and the heater of steel also make the experiment suitable for studies of iron-bentonite interactions. This report concerns the work accomplished up to now and is not to be treated as any final report of the project.

  7. Hydrophobicity classification of polymeric materials based on fractal dimension

    Directory of Open Access Journals (Sweden)

    Daniel Thomazini

    2008-12-01

    Full Text Available This study proposes a new method to obtain hydrophobicity classification (HC in high voltage polymer insulators. In the method mentioned, the HC was analyzed by fractal dimension (fd and its processing time was evaluated having as a goal the application in mobile devices. Texture images were created from spraying solutions produced of mixtures of isopropyl alcohol and distilled water in proportions, which ranged from 0 to 100% volume of alcohol (%AIA. Based on these solutions, the contact angles of the drops were measured and the textures were used as patterns for fractal dimension calculations.

  8. 10 CFR 435.3 - Material incorporated by reference.

    Science.gov (United States)

    2010-01-01

    ... Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY STANDARDS FOR NEW FEDERAL LOW-RISE RESIDENTIAL BUILDINGS Mandatory Energy Efficiency Standards for Federal Low-Rise Residential Buildings. § 435... this material by the standard-setting organization will not affect the DOE building energy...

  9. Determination of water in NIST reference material for mineral oils

    Science.gov (United States)

    Cedergren; Nordmark

    2000-07-15

    The accuracy of the reference concentrations of moisture in electrical insulating oil RM 8506 and lubricating oil RM 8507 (both of mineral type) and specified by the National Institute of Standards and Technology (NIST) as containing 39.7 and 76.8 ppm (w/w) water, respectively, has recently been the subject of debate in this journal. To shed some further light on this controversy, we report in this correspondence results for these oils obtained by two additional methods, one based on specially designed reagents for diaphragm-free Karl Fischer (KF) coulometry and the other based on the concept of stripping at elevated temperature/continuous KF coulometry. A positive interference effect was shown to take place for RM 8506 when the direct coulometric method was used. If the results are corrected for this, the values including six different procedures varied in the range 13.5-15.6 ppm (w/w). For RM 8507, all values were between 42.5 and 47.2 ppm (w/w), which means that the values recommended by NIST for both reference oils using volumetric titration are about twice as high as those obtained with the other techniques. A possible explanation for this discrepancy is presented.

  10. Classification

    DEFF Research Database (Denmark)

    Hjørland, Birger

    2017-01-01

    This article presents and discusses definitions of the term “classification” and the related concepts “Concept/conceptualization,”“categorization,” “ordering,” “taxonomy” and “typology.” It further presents and discusses theories of classification including the influences of Aristotle...... and Wittgenstein. It presents different views on forming classes, including logical division, numerical taxonomy, historical classification, hermeneutical and pragmatic/critical views. Finally, issues related to artificial versus natural classification and taxonomic monism versus taxonomic pluralism are briefly...

  11. A new classification system for all-ceramic and ceramic-like restorative materials.

    Science.gov (United States)

    Gracis, Stefano; Thompson, Van P; Ferencz, Jonathan L; Silva, Nelson R F A; Bonfante, Estevam A

    2015-01-01

    Classification systems for all-ceramic materials are useful for communication and educational purposes and warrant continuous revisions and updates to incorporate new materials. This article proposes a classification system for ceramic and ceramic-like restorative materials in an attempt to systematize and include a new class of materials. This new classification system categorizes ceramic restorative materials into three families: (1) glass-matrix ceramics, (2) polycrystalline ceramics, and (3) resin-matrix ceramics. Subfamilies are described in each group along with their composition, allowing for newly developed materials to be placed into the already existing main families. The criteria used to differentiate ceramic materials are based on the phase or phases present in their chemical composition. Thus, an all-ceramic material is classified according to whether a glass-matrix phase is present (glass-matrix ceramics) or absent (polycrystalline ceramics) or whether the material contains an organic matrix highly filled with ceramic particles (resin-matrix ceramics). Also presented are the manufacturers' clinical indications for the different materials and an overview of the different fabrication methods and whether they are used as framework materials or monolithic solutions. Current developments in ceramic materials not yet available to the dental market are discussed.

  12. [Latin American regional reference materials for porcine heparin and bovine heparin].

    Science.gov (United States)

    Albertengo, M E; Cinto, R O; Araldi, H T; Vernengo, M J

    1990-02-01

    In agreement with the Regional Programme of Reference Materials of the Panamerican Health Organization the Instituto Nacional de Farmacología y Bromatología of Buenos Aires designed a study for the calibration of a Reference Material for Heparin, porcine, mucosal and a Reference Material for Heparin, bovine, mucosal. The assay methods used in this study were those described in the United States Pharmacopeia XXI Ed and British Pharmacopoeia 1980, Addendum 1983. The overall combined potency estimates of both heparin in preparations relative to 4th Int.St. was 1633.83 UI/ampoule (95% confidence limits 1609.70-1657.96 UI/ampoule) for porcine heparin and 1332.31 UI/ampoule (95% confidence limits, 1302.31-1361.77 UI/ampoule) for bovine heparin. The assigned unitage was 1630 UI/ampoule for the porcine Reference Material and 1330 UI/ampoule for the bovine Reference Material.

  13. An Ontology to Support the Classification of Learning Material in an Organizational Learning Environment: An Evaluation

    Science.gov (United States)

    Valaski, Joselaine; Reinehr, Sheila; Malucelli, Andreia

    2017-01-01

    Purpose: The purpose of this research was to evaluate whether ontology integrated in an organizational learning environment may support the automatic learning material classification in a specific knowledge area. Design/methodology/approach: An ontology for recommending learning material was integrated in the organizational learning environment…

  14. Evolutionary design of bone scaffolds with reference to material selection.

    Science.gov (United States)

    Heljak, M K; Swięszkowski, W; Lam, C X F; Hutmacher, D W; Kurzydłowski, K J

    2012-01-01

    The favourable scaffold for bone tissue engineering should have desired characteristic features, such as adequate mechanical strength and three-dimensional open porosity, which guarantee a suitable environment for tissue regeneration. In fact, the design of such complex structures like bone scaffolds is a challenge for investigators. One of the aims is to achieve the best possible mechanical strength-degradation rate ratio. In this paper we attempt to use numerical modelling to evaluate material properties for designing bone tissue engineering scaffold fabricated via the fused deposition modelling technique. For our studies the standard genetic algorithm was used, which is an efficient method of discrete optimization. For the fused deposition modelling scaffold, each individual strut is scrutinized for its role in the architecture and structural support it provides for the scaffold, and its contribution to the overall scaffold was studied. The goal of the study was to create a numerical tool that could help to acquire the desired behaviour of tissue engineered scaffolds and our results showed that this could be achieved efficiently by using different materials for individual struts. To represent a great number of ways in which scaffold mechanical function loss could proceed, the exemplary set of different desirable scaffold stiffness loss function was chosen.

  15. Future needs and requirements for AMS {sup 14}C standards and reference materials

    Energy Technology Data Exchange (ETDEWEB)

    Scott, E. Marian E-mail: marian@stats.gla.ac.uk; Boaretto, Elisabetta; Bryant, Charlotte; Cook, Gordon T.; Gulliksen, Steinar; Harkness, Doug D.; Heinemeier, Jan; McGee, Edward; Naysmith, Philip; Possnert, Goran; Plicht, Hans van der; Strydonck, Mark van

    2004-08-01

    {sup 14}C measurement uses a number of standards and reference materials with different properties. Historically the absolute calibration of {sup 14}C measurement was tied to 1890 wood, through the 'primary' standard of NBS-OxI (produced by the National Bureau of Standards, now NIST - National Institute of Standards and technology) subsequently replaced by NBS-OxII. These are both internationally calibrated and certified materials, whose {sup 14}C activities are known absolutely. A second tier of materials, often called secondary standards or reference materials, and including internationally recognised materials such as ANU-sucrose (now also IAEA-C6), Chinese - sucrose and the IAEA C1-C6 series, augmented by additional oxalic acid samples are also used routinely. The activity of these materials has been estimated from large numbers of measurements made by many laboratories. Recently, further natural materials from the Third and Fourth International Radiocarbon Inter-comparisons (TIRI and FIRI) have been added to this list. The activities of these standards and reference materials span both the applied {sup 14}C age range and the chemical composition range of typical samples, but this is not achieved uniformly and there is a continuing need for reference materials for laboratory quality control and measurement-traceability purposes. In this paper, we review the development of {sup 14}C standards and reference materials and consider the future requirements for such materials within the {sup 14}C AMS community.

  16. Teachers' opinion about learning continuum based on student's level of competence and specific pedagogical material in classification topics

    Science.gov (United States)

    Andriani, Aldina Eka; Subali, Bambang

    2017-08-01

    This research discusses learning continuum development for designing a curriculum. The objective of this study is to gather the opinion of public junior and senior high school teachers about learning continuum based on student's level of competence and specific pedagogical material in classification topics. This research was conducted in Yogyakarta province from October 2016 to January 2017. This research utilizes a descriptive survey method. Respondents in this study consist of 281 science teachers at junior and senior high school in Yogyakarta city and 4 regencies namely Sleman, Bantul, Kulonprogo, and Gunung Kidul. The sample were taken using a census. The collection of data used questionnaire that had been validated from the aspects of construct validity and experts judgements. Data were analyzed using a descriptive analysis technique. The results of the analysis show that the opinions of teachers regarding specific pedagogical material in classification topics of living things at the junior high school taught in grade VII to the ability level of C2 (Understanding). At senior high school level, it is taught in grade X with the ability level C2 (Understanding). Based on these results, it can be concluded that the opinions of teachers still refer to the current syllabus and curriculum so that the teachers do not have pure opinions about the student's competence level in classification topics that should be taught at the level of the grade in accordance with the level of corresponding competency.

  17. Spectral Classification of Similar Materials using the Tetracorder Algorithm: The Calcite-Epidote-Chlorite Problem

    Science.gov (United States)

    Dalton, J. Brad; Bove, Dana; Mladinich, Carol; Clark, Roger; Rockwell, Barnaby; Swayze, Gregg; King, Trude; Church, Stanley

    2001-01-01

    Recent work on automated spectral classification algorithms has sought to distinguish ever-more similar materials. From modest beginnings separating shade, soil, rock and vegetation to ambitious attempts to discriminate mineral types and specific plant species, the trend seems to be toward using increasingly subtle spectral differences to perform the classification. Rule-based expert systems exploiting the underlying physics of spectroscopy such as the US Geological Society Tetracorder system are now taking advantage of the high spectral resolution and dimensionality of current imaging spectrometer designs to discriminate spectrally similar materials. The current paper details recent efforts to discriminate three minerals having absorptions centered at the same wavelength, with encouraging results.

  18. Spectral Classification of Similar Materials using the Tetracorder Algorithm: The Calcite-Epidote-Chlorite Problem

    Science.gov (United States)

    Dalton, J. Brad; Bove, Dana; Mladinich, Carol; Clark, Roger; Rockwell, Barnaby; Swayze, Gregg; King, Trude; Church, Stanley

    2001-01-01

    Recent work on automated spectral classification algorithms has sought to distinguish ever-more similar materials. From modest beginnings separating shade, soil, rock and vegetation to ambitious attempts to discriminate mineral types and specific plant species, the trend seems to be toward using increasingly subtle spectral differences to perform the classification. Rule-based expert systems exploiting the underlying physics of spectroscopy such as the US Geological Society Tetracorder system are now taking advantage of the high spectral resolution and dimensionality of current imaging spectrometer designs to discriminate spectrally similar materials. The current paper details recent efforts to discriminate three minerals having absorptions centered at the same wavelength, with encouraging results.

  19. Embrapa's experience in the production and development of agriculture reference materials

    Science.gov (United States)

    Nogueira, A. R. A.; Souza, G. B.; Bossu, C. M.; Bianchi, S. R.; Verhalen, T. R.; Silva, P. T.; Peixoto, A. A. J.; Silva, C. S.

    2016-07-01

    The main challenge of Embrapa is to develop a model of genuine Brazilian tropical agriculture and livestock. To get this task, the quality of laboratories results is mandatory, increasing the demand for reference materials. Projects were proposed to produce reference materials to support the national agriculture laboratories and consolidate a network able to perform reliable and reproducible analytical testing laboratory within the internationally standards required. Reference materials were produced and available to interested laboratories and collaborative tests were conducted to obtain consensus values. The results and statistical evaluations were performed with the use of software developed by Embrapa Pecuaria Sudeste.

  20. Element concentrations in candidate biological and environmental reference materials by k[sub 0]-standardized INAA

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, M.C. (LNETI, Inst. de Ciencias e Engenharia Nucleares, Dept. de Energia e Engenharia Nucleares, Sacavem (Portugal))

    1993-01-01

    k[sub 0]-Based Neutron Activation Analysis (k[sub 0]INAA) was used to analyze the candidate reference materials Apple Leaves and Peach Leaves, and Oriental Tobacco Leaves and Virginia Tobacco Leaves. Concentration values for 27 elements were measured. The accuracy was ascertained by analysis of two certified reference materials. NIST 1572 Citrus Leaves and 1573 Tomato Leaves. The homogeneity test of the IAEA Evernia prunastri candidate reference material in aliquots [>=] 100 mg is extended to the elements Sc, Cr, Fe, Co, Zn, Rb, Sb, Cs, Ba, Ce and Th. (orig.).

  1. ARTIFICIAL NEURAL NETWORKS FOR MATERIAL CLASSIFICATION IN PURCHASING PORTFOLIO MANAGEMENT

    OpenAIRE

    de Santis, Rodrigo Barbosa; de Aguiar, Eduardo Pestana; Goliatt, Leonardo .

    2017-01-01

    Abstract. Strategic sourcing is an important technique within supply chain management area that allows companies to understand their purchasing portfolio and to better take advantage of their bargain power versus key suppliers, reducing supply risks to an acceptable minimum. The Kraljic portfolio matrix is an important model for evaluating materials and services categoriesin two main aspects: the importance of a particular purchasing and the complexity of the supply market. Although, the clas...

  2. Preparation and characterization of the fish reference material; Preparacao e caracterizacao de um material de referencia de peixe

    Energy Technology Data Exchange (ETDEWEB)

    Ulrich, Joao Cristiano

    2011-07-01

    The certified reference materials (CRMs) play an important role in obtaining measurement results traceable to the International System of Units, through an unbroken chain of comparisons. Thus, the demand for new certified reference materials (CRMs) increases every day in all areas of knowledge. The availability of reference materials, mainly in Brazil is still incipient, given that the demand far exceeds the available variety of these materials. The amount of certified reference materials available in the country is insufficient to meet the need of the scientific community and demands for development of new methodologies. Among the many areas in need of reference materials, we highlight the importance for the food trade balance for these products within the country. The certification of food products, intended both for export and for domestic consumption, requires analysis methods that provide precise and accurate results to ensure product quality. This paper describes the preparation and certification of a reference material in the fish matrix in mercury and methylmercury. The study brings together since the stage of material selection, preparation, development of homogeneity and stability studies and characterization. The certification was performed by means of measurements using two analytical techniques, flow injection analysis - cold vapor atomic absorption spectrometry (FIA-CV-AAS) and isotope dilution applied to mass spectrometry (IDMS), which is a primary method. In this work the standards of the ISO 30 (ABNT 30-34) and ISO Guide 35 was used as the basis for the preparation and characterization of the material. For the calculation of uncertainties was used the GUM and Eurachem guide. As a result, was produced and certified a lot of material in relation to the concentration of mercury (Hg = 0.271 {+-} 0.057 mg g{sup -1}) and methylmercury (MeHg = 0.245 {+-} 0.038 mg g{sup -1}), and informational values of lead and arsenic. (author)

  3. Cross-Reference Benchmarks for Translating the Genetic Soil Classification of China into the Chinese Soil Taxonomy

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Soil classification is the foundation for exchange and extension of research findings in soil science and for modern management of soil resources. This study explained database and research methodology to create a cross-reference system for translating the Genetic Soil Classification of China (GSCC) into the Chinese Soil Taxonomy (CST). With the help of the CST keys, each of the 2 540 soil species in GSCC has been interpreted to its corresponding soil order, suborder,great group, and sub-group in CST. According to the methodology adopted, the assigned soil species have been linked one another to their corresponding polygons in the 1:1000 000 digital soil map of China. Referencibility of each soil species between the GSCC and CST systems was determined statistically on the basis of distribution area of each soil species at a high taxon level of the two systems. The soils were then sorted according to their maximum referencibility and classified into three categories for discussion. There were 19 soil great groups in GSCC with maximum referencibility > 90% and 22great groups between 60%-90%. These soil great groups could serve as cross-reference benchmarks. There were 19 great groups in GSCC with maximum referencibility < 60%, which could be used as cross-reference benchmarks until new and better results were available. For these soils, if the translation was made at a lower soil taxon level or on a regional basis,it would improve their referencibility enabling them to serve as new cross-reference benchmarks.

  4. On draft of intergovernmental agreement for development and use of reference materials of composition and properties of substances and materials

    Directory of Open Access Journals (Sweden)

    E. V. Osintseva

    2016-01-01

    Full Text Available The article deals with information of development of a draft of Agreement for development and use of reference materials of composition and properties of substances and materials which was developed within Interstate Council for Standardization, Metrology and Certification

  5. Determination and Certification of Multielements in 6 Biological Reference Materials by NAA

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>Food safety has been a problem of global concern. The insufficient availability of certificated reference materials (CRM) used for food analysis has resulted in a lack of internal quality control in food

  6. Evaluation of Botanical Reference Materials for the Determination of Vanadium in Biological Samples

    DEFF Research Database (Denmark)

    Heydorn, Kaj; Damsgaard, Else

    1982-01-01

    Three botanical reference materials prepared by the National Bureau of Standards have been studied by neutron activation analysis to evaluate their suitability with respect to the determination of vanadium in biological samples. Various decomposition methods were applied in connection with chemic....... A reference value of 1.15 mg/kg of this material is recommended, based on results from 3 different methods. All three materials are preferable to SRM 1571 Orchard Leaves, while Bowen's Kale remains the material of choice because of its lower concentration....

  7. Feature Extraction and Automatic Material Classification of Underground Objects from Ground Penetrating Radar Data

    Directory of Open Access Journals (Sweden)

    Qingqing Lu

    2014-01-01

    Full Text Available Ground penetrating radar (GPR is a powerful tool for detecting objects buried underground. However, the interpretation of the acquired signals remains a challenging task since an experienced user is required to manage the entire operation. Particularly difficult is the classification of the material type of underground objects in noisy environment. This paper proposes a new feature extraction method. First, discrete wavelet transform (DWT transforms A-Scan data and approximation coefficients are extracted. Then, fractional Fourier transform (FRFT is used to transform approximation coefficients into fractional domain and we extract features. The features are supplied to the support vector machine (SVM classifiers to automatically identify underground objects material. Experiment results show that the proposed feature-based SVM system has good performances in classification accuracy compared to statistical and frequency domain feature-based SVM system in noisy environment and the classification accuracy of features proposed in this paper has little relationship with the SVM models.

  8. Global Stress Classification System for Materials Used in Solar Energy Applications

    Science.gov (United States)

    Slamova, Karolina; Schill, Christian; Herrmann, Jan; Datta, Pawan; Chih Wang, Chien

    2016-08-01

    Depending on the geographical location, the individual or combined impact of environmental stress factors and corresponding performance losses for solar applications varies significantly. Therefore, as a strategy to reduce investment risks and operating and maintenance costs, it is necessary to adapt the materials and components of solar energy systems specifically to regional environmental conditions. The project «GloBe Solar» supports this strategy by focusing on the development of a global stress classification system for materials in solar energy applications. The aim of this classification system is to assist in the identification of the individual stress conditions for every location on the earth's surface. The stress classification system could serve as a decision support tool for the industry (manufacturers, investors, lenders and project developers) and help to improve knowledge and services that can provide higher confidence to solar power systems.

  9. Certification of elements in and use of standard reference material 3280 multivitamin/multielement tablets

    Science.gov (United States)

    Standard Reference Material (SRM) 3280 Multivitamin/Multielement Tablets was issued by the National Institute of Standards and Technology (NIST) in 2009 and has certified and reference mass fraction values for 13 vitamins, 26 elements, and 2 carotenoids. Elements were measured using two or more ana...

  10. REFERENCE MATERIALS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Potala PalaceConstruction of the Potala Palace began in the mid-7th century for the Tubo King Songtsan Gambo to greet his Han wife, Princess Wencheng. It comprised 999 rooms then, plus one built atop the Red Hill, which, said to have 1,000 rooms, was later destroyed by thunderbolts and wars. What we see today is a structure built during the 17th century.In the mid-17th century, the White House was added to the Potala Palace, which spread along the Red Hill in Lhasa.The palace is a structure of clay, wood and stone. The palace was the residence of the Dalai Lama of various generations. Beginning with the period of the 5th Dalai Lama, major religious and political ceremonies were held there.The palace covers a total area of 360,000 square meters, with major building rising 117 meters high in 13 floors, and extends some 360 meters from east to west.From 1989 to 1994, the State earmarked some 55 million Yuan and large quantities of gold and silver to repair the palace.In December 1994, the palace found its w

  11. Classification of materials using nuclear magnetic resonance dispersion and/or x-ray absorption

    Science.gov (United States)

    Espy, Michelle A.; Matlashov, Andrei N.; Schultz, Larry J.; Volegov, Petr L.; Urbaitis, Algis; Sandin, Henrik; Yoder, Jacob; Surko, Stephen

    2017-01-31

    Methods for determining the identity of a substance are provided. A classification parameter set is defined to allow identification of substances that previously could not be identified or to allow identification of substances with a higher degree of confidence. The classification parameter set may include at least one of relative nuclear susceptibility (RNS) or an x-ray linear attenuation coefficient (LAC). RNS represents the density of hydrogen nuclei present in a substance relative to the density of hydrogen nuclei present in water. The extended classification parameter set may include T.sub.1, T.sub.2, and/or T.sub.1.rho. as well as at least one additional classification parameter comprising one of RNS or LAC. Values obtained for additional classification parameters as well as values obtained for T.sub.1, T.sub.2, and T.sub.1.rho. can be compared to known classification parameter values to determine whether a particular substance is a known material.

  12. Classification of materials using nuclear magnetic resonance dispersion and/or x-ray absorption

    Energy Technology Data Exchange (ETDEWEB)

    Espy, Michelle A.; Matlashov, Andrei N.; Schultz, Larry J.; Volegov, Petr L.; Urbaitis, Algis; Sandin, Henrik; Yoder, Jacob; Surko, Stephen

    2017-01-31

    Methods for determining the identity of a substance are provided. A classification parameter set is defined to allow identification of substances that previously could not be identified or to allow identification of substances with a higher degree of confidence. The classification parameter set may include at least one of relative nuclear susceptibility (RNS) or an x-ray linear attenuation coefficient (LAC). RNS represents the density of hydrogen nuclei present in a substance relative to the density of hydrogen nuclei present in water. The extended classification parameter set may include T.sub.1, T.sub.2, and/or T.sub.1.rho. as well as at least one additional classification parameter comprising one of RNS or LAC. Values obtained for additional classification parameters as well as values obtained for T.sub.1, T.sub.2, and T.sub.1.rho. can be compared to known classification parameter values to determine whether a particular substance is a known material.

  13. [Evaluation and characterization of the certified reference materials for coagulation factor Ⅷ and Ⅸ activity testing].

    Science.gov (United States)

    Zhang, H P; Zhou, W B; Li, C B; Du, Z L; Peng, M T

    2016-05-31

    To evaluate and characterize the certified reference materials for coagulation factor Ⅷ (FⅧ) and factor Ⅸ (FⅨ) activity testing. The homogeneity and stability of three lots of certified reference materials (F01-F03) with different factor concentrations were evaluated according to guidelines"Reference materials-general and statistical principles for certification","Guidance on evaluating the homogeneity and stability of samples used for proficiency testing"and"Technical Norm of Primary Reference Material". The certified reference materials were characterized by eight laboratories using one-stage method, which were calibrated by the coagulation standard provided by the National Institute for Biological Standards and Control (NIBSC) in UK. The Coefficient of Variation (CV) of homogeneity test of FⅧ activity of three lots of certified reference materials were 3.9%, 3.3% and 3.4%, respectively. While that of FⅨ activity were 3.7%, 3.0% and 1.8%, respectively. The results of one-way ANOVA showed that all certified reference materials had good homogeneity (P>0.05), and the between-bottle homogeneity uncertainties (ubb) of FⅧ and FⅨ activity were 0.5%-2.9% and 0.1%-3.9%, respectively. All certified reference materials stored in -80 ℃ remained stable in 9 months by trend analysis, and the long-term stability uncertainties(ults) of FⅧ and FⅨ activity were 0.5%-5.1% and 1.3%-4.4%, respectively. The characterization uncertainties (uchar) of FⅧ and FⅨ activity testing were 0.9%-2.4% and 1.1%-2.4%, respectively. The combined uncertainties and extended uncertainties (coverage factor k=2) were calculated. The assigned values of each lot of certified reference materials for FⅧ activity were (85±13)%, (36.0±3.4)% and (20.5±2.3)%, and that were (102±13)%, (47.8±6.9)% and (29.3±3.8)% for FⅨ activity, respectively. The certified reference materials for FⅧ and FⅨ activity testing have good homogeneity and stability. The results of the

  14. Reference material for radionuclides in sediment IAEA-384 (Fangataufa Lagoon sediment)

    DEFF Research Database (Denmark)

    Povinec, P.P.; Pham, M.K.; Sanchez-Cabeza, J.A.;

    2007-01-01

    A reference material designed for the determination of anthropogenic and natural radionuclides in sediment, IAEA-384 (Fangataufa Lagoon sediment), is described and the results of certification are presented. The material has been certified for 8 radionuclides (K-40, Co-60, Eu-155, Th-230, U-238, ...

  15. Certified Reference Material IAEA-446 for radionuclides in Baltic Sea seaweed

    DEFF Research Database (Denmark)

    Pham, M.K.; Benmansour, M.; Carvalho, F.P.

    2014-01-01

    A Certified Reference Material (CRM) for radionuclides in seaweed (Fucus vesiculosus) from the Baltic Sea (IAEA-446) is described and the results of the certification process are presented. The 40K, 137Cs, 234U and 239þ240Pu radionuclides were certified for this material, and information values...

  16. Certified reference materials for food packaging specific migration tests: development, validation and modelling

    NARCIS (Netherlands)

    Stoffers, N.H.

    2005-01-01

    Keywords:certified reference materials; diffusion; food contact materials; food packaging; laurolactam; migration modelling; nylon; specific migration This thesis compiles several research topics

  17. Certificate of Analysis, Standard Reference Material® 1849, Infant/Adult Nutritional Formula

    Science.gov (United States)

    Standard Reference material (SRM) 1849 is intended primarily for validation of methods for determining proximates, fatty acids, vitamins, elements and nucleotides in infant and adult nutritional formulas and similar materials. This SRM can also be used for quality assurance when assigning values to ...

  18. Determination of perfluorinated alkyl acid concnetrations in biological standard reference materials

    NARCIS (Netherlands)

    Reiner, J.L.; O'Connell, S.G.; Butt, C.M.; Kwadijk, C.J.A.F.

    2012-01-01

    Standard reference materials (SRMs) are homogeneous, well-characterized materials used to validate measurements and improve the quality of analytical data. The National Institute of Standards and Technology (NIST) has a wide range of SRMs that have mass fraction values assigned for legacy pollutants

  19. Screening tests for hazard classification of complex waste materials - Selection of methods

    Energy Technology Data Exchange (ETDEWEB)

    Weltens, R., E-mail: reinhilde.weltens@vito.be [VITO Flemish Institute for Technological Research, Boeretang 200, B 2400 Mol (Belgium); Vanermen, G.; Tirez, K. [VITO Flemish Institute for Technological Research, Boeretang 200, B 2400 Mol (Belgium); Robbens, J. [University of Antwerp - Laboratory for Ecophysiology, Biochemistry and Toxicology, Groenenborgerlaan 171, B2020 Antwerp (Belgium); Deprez, K.; Michiels, L. [University of Hasselt - Biomedical Research Institute, University Hasselt, Campus Diepenbeek, Agoralaan A, B3590 Diepenbeek (Belgium)

    2012-12-15

    In this study we describe the development of an alternative methodology for hazard characterization of waste materials. Such an alternative methodology for hazard assessment of complex waste materials is urgently needed, because the lack of a validated instrument leads to arbitrary hazard classification of such complex waste materials. False classification can lead to human and environmental health risks and also has important financial consequences for the waste owner. The Hazardous Waste Directive (HWD) describes the methodology for hazard classification of waste materials. For mirror entries the HWD classification is based upon the hazardous properties (H1-15) of the waste which can be assessed from the hazardous properties of individual identified waste compounds or - if not all compounds are identified - from test results of hazard assessment tests performed on the waste material itself. For the latter the HWD recommends toxicity tests that were initially designed for risk assessment of chemicals in consumer products (pharmaceuticals, cosmetics, biocides, food, etc.). These tests (often using mammals) are not designed nor suitable for the hazard characterization of waste materials. With the present study we want to contribute to the development of an alternative and transparent test strategy for hazard assessment of complex wastes that is in line with the HWD principles for waste classification. It is necessary to cope with this important shortcoming in hazardous waste classification and to demonstrate that alternative methods are available that can be used for hazard assessment of waste materials. Next, by describing the pros and cons of the available methods, and by identifying the needs for additional or further development of test methods, we hope to stimulate research efforts and development in this direction. In this paper we describe promising techniques and argument on the test selection for the pilot study that we have performed on different types of

  20. Classification of fire-technical characteristic of roofing materials in European and Russian regulation documents

    Directory of Open Access Journals (Sweden)

    Gravit Marina

    2016-01-01

    Full Text Available The authors analyze the fire-danger index of building materials (such as roofing materials in European and Russian regulations. The parameters which were obtained during tests in accordance with standard of roofing materials in European and Russian methods of testing were analyzed. Some of the tests to determine the properties of the fire hazard of building materials are identical. Contributors show that the European standardization system has a much wider range of test methods for determining the properties of fire safety of construction materials. In Russia, for some tests is not unique (the test in a corner room, non-flammability tests, etc.. We concluded that the European standards for building materials are more stringent and also that the correlation between the various indicators missing. We demonstrate significant differences in the European and Russian fire hazard classification of identical roofing materials.

  1. RNA-CODE: a noncoding RNA classification tool for short reads in NGS data lacking reference genomes.

    Directory of Open Access Journals (Sweden)

    Cheng Yuan

    Full Text Available The number of transcriptomic sequencing projects of various non-model organisms is still accumulating rapidly. As non-coding RNAs (ncRNAs are highly abundant in living organism and play important roles in many biological processes, identifying fragmentary members of ncRNAs in small RNA-seq data is an important step in post-NGS analysis. However, the state-of-the-art ncRNA search tools are not optimized for next-generation sequencing (NGS data, especially for very short reads. In this work, we propose and implement a comprehensive ncRNA classification tool (RNA-CODE for very short reads. RNA-CODE is specifically designed for ncRNA identification in NGS data that lack quality reference genomes. Given a set of short reads, our tool classifies the reads into different types of ncRNA families. The classification results can be used to quantify the expression levels of different types of ncRNAs in RNA-seq data and ncRNA composition profiles in metagenomic data, respectively. The experimental results of applying RNA-CODE to RNA-seq of Arabidopsis and a metagenomic data set sampled from human guts demonstrate that RNA-CODE competes favorably in both sensitivity and specificity with other tools. The source codes of RNA-CODE can be downloaded at http://www.cse.msu.edu/~chengy/RNA_CODE.

  2. A study of production of radioactive environmental reference materials used for proficiency testing program in Taiwan.

    Science.gov (United States)

    Peng, En-Chi; Wang, Jeng-Jong

    2013-11-01

    To realise radioactive environmental reference materials in Taiwan, seven environmental materials of soil, water, vegetation, meat, airborne particles (filter paper), milk and mushroom samples that are frequently encountered were used to establish the preparation of the reference materials. These seven environmental materials were collected, checked for freedom from radioactivity and prepared according to their properties. The preparation was carried out by using activity about 10-100 times that of the minimum detectable activity (MDA) in routine measurements in the radioactive standard used to spike the inactive material and this standard is traceable to national ionising radioactivity standards (TAF, 2004). To demonstrate sample traceability to the added standard, each sample was carefully measured and its uncertainty evaluated. Based on the recommendations of ISO Guide 35 for evaluation of reference materials and with the above assessment and verification procedures, the uncertainties (k=1) of the spike activity used in making reference materials were: (60)Co≤4.6%, (134)Cs≤4.7%, (137)Cs≤5.0%, total β≤0.6% and (3)H≤1.3%.

  3. A Void Reference Sensor-Multiple Signal Classification Algorithm for More Accurate Direction of Arrival Estimation of Low Altitude Target

    Institute of Scientific and Technical Information of China (English)

    XIAO Hui; SUN Jin-cai; YUAN Jun; NIU Yi-long

    2007-01-01

    There exists MUSIC (multiple signal classification) algorithm for direction of arrival (DOA) estimation. This paper is to present a different MUSIC algorithm for more accurate estimation of low altitude target. The possibility of better performance is analyzed using a void reference sensor (VRS) in MUSIC algorithm. The following two topics are discussed: 1) the time delay formula and VRS-MUSIC algorithm with VRS located on the minus of z-axes; 2) the DOA estimation results of VRS-MUSIC and MUSIC algorithms. The simulation results show VRS-MUSIC algorithm has three advantages compared with MUSIC: 1 ) When the signal to noise ratio (SNR) is more than - 5 dB, the direction estimation error is 1/2 as much as that obtained by MUSIC; 2) The side lobe is more lower and the stability is better; 3) The size of array that the algorithm requires is smaller.

  4. Fractographic classification in metallic materials by using 3D processing and computer vision techniques

    Directory of Open Access Journals (Sweden)

    Maria Ximena Bastidas-Rodríguez

    2016-09-01

    Full Text Available Failure analysis aims at collecting information about how and why a failure is produced. The first step in this process is a visual inspection on the flaw surface that will reveal the features, marks, and texture, which characterize each type of fracture. This is generally carried out by personnel with no experience that usually lack the knowledge to do it. This paper proposes a classification method for three kinds of fractures in crystalline materials: brittle, fatigue, and ductile. The method uses 3D vision, and it is expected to support failure analysis. The features used in this work were: i Haralick’s features and ii the fractal dimension. These features were applied to 3D images obtained from a confocal laser scanning microscopy Zeiss LSM 700. For the classification, we evaluated two classifiers: Artificial Neural Networks and Support Vector Machine. The performance evaluation was made by extracting four marginal relations from the confusion matrix: accuracy, sensitivity, specificity, and precision, plus three evaluation methods: Receiver Operating Characteristic space, the Individual Classification Success Index, and the Jaccard’s coefficient. Despite the classification percentage obtained by an expert is better than the one obtained with the algorithm, the algorithm achieves a classification percentage near or exceeding the 60 % accuracy for the analyzed failure modes. The results presented here provide a good approach to address future research on texture analysis using 3D data.

  5. Microhomogeneity in reference materials for microanalytical methods - a possible recourse from a blind alley?

    Science.gov (United States)

    Renno, A. D.; Michalak, P. P.; Munnik, F.; Tolosana-Delgado, R.; van den Boogaart, G. K.

    2013-12-01

    It is assumed that reference materials for microanalytical methods must be homogeneous, i.e. have the same concentration of the relevant element(s) overall, to ensure that they can be used reliably to get comparison values during the analysis with non absolute methods. With increasing resolution it becomes more and more difficult to ensure such homogeneity, up to the point that it is not possible for several microanalytical methods. Painstaking search for homogeneous natural minerals in gem quality or elaborate expensive methods to produce synthetic minerals provide as obvious solutions to the problem. We propose a way to get reliable reference values with some types of inhomogeneous material, based on multiple probing the reference material. Consider a reference material, which average concentration on the relevant element and its microscale variability has been adequately characterized by a destructive method at a series of grid spots. The minimal number of probing spots required for a certain precision level can be derived from the variance calculations. This procedure is always valid, whenever the heterogeneity value distribution of the reference material has a variance, but at the price that the number of spots will be huge if it is large. However, using adequate models of local heterogeneity can greatly reduce that number. Geostatistics can be used in random, systematic and periodic heterogeneities, while robust methods are useful in cases of nugget heterogeneities. Typical examples of natural and synthetic minerals, analysed by electron microprobe and micro-PIXE (particle induced X-ray emission) for microhomogeneity/microheterogeneity are shown. The distinctions between the two strategies of using these materials as a potential reference material are demonstrated.

  6. Reference materials and representative test materials to develop nanoparticle characterization methods: the NanoChOp project case

    Science.gov (United States)

    Roebben, Gert; Kestens, Vikram; Varga, Zoltan; Charoud-Got, Jean; Ramaye, Yannic; Gollwitzer, Christian; Bartczak, Dorota; Geißler, Daniel; Noble, James; Mazoua, Stéphane; Meeus, Nele; Corbisier, Philippe; Palmai, Marcell; Mihály, Judith; Krumrey, Michael; Davies, Julie; Resch-Genger, Ute; Kumarswami, Neelam; Minelli, Caterina; Sikora, Aneta; Goenaga-Infante, Heidi

    2015-10-01

    This paper describes the production and characteristics of the nanoparticle test materials prepared for common use in the collaborative research project NanoChOp (Chemical and optical characterisation of nanomaterials in biological systems), in casu suspensions of silica nanoparticles and CdSe/CdS/ZnS quantum dots. This paper is the first to illustrate how to assess whether nanoparticle test materials meet the requirements of a 'reference material' (ISO Guide 30:2015) or rather those of the recently defined category of 'representative test material' (ISO TS 16195:2013). The NanoChOp test materials were investigated with small-angle X-ray scattering (SAXS), dynamic light scattering (DLS) and centrifugal liquid sedimentation (CLS) to establish whether they complied with the required monomodal particle size distribution. The presence of impurities, aggregates, agglomerates and viable microorganisms in the suspensions was investigated with DLS, CLS, optical and electron microscopy and via plating on nutrient agar. Suitability of surface functionalization was investigated with attenuated total reflection Fourier transform infrared spectrometry (ATR-FTIR) and via the capacity of the nanoparticles to be fluorescently labeled or to bind antibodies. Between-unit homogeneity and stability were investigated in terms of particle size and zeta potential. This paper shows that only based on the outcome of a detailed characterization process one can raise the status of a test material to representative test material or reference material, and how this status depends on its intended use.

  7. Precise Determination of Silicon in Ceramic Reference Materials by Prompt Gamma Activation Analysis at JRR-3

    Directory of Open Access Journals (Sweden)

    Tsutomu Miura

    2016-04-01

    Full Text Available Prompt gamma activation analysis using a thermal neutron-guided beam at Japan Atomic Energy Agency JRR-3M was applied for the precise determination of Si in silicon nitride ceramic reference materials [Japan Ceramic Reference Material (JCRM R 003]. In this study, the standard addition method coupled with internal standard was used for the nondestructive determination of Si in the sample. Cadmium was used as internal standard to obtain the linear calibration curves and to compensate for the neutron beam variability. The analytical result of determining Si in JCRM R 003 silicon nitride fine powder ceramic reference materials using prompt gamma activation analysis was in good agreement with that obtained by classical gravimetric analysis. The relative expanded measurement uncertainty (k = 2 associated with the determined value was 2.4%.

  8. Precise determination of silicon in ceramic reference materials by prompt gamma activation analysis at JRR-3

    Energy Technology Data Exchange (ETDEWEB)

    Miura, Tsutomu [National Metrology Institute of Japan-AIST, Ibaraki (Japan); Matsue, Hideaki [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Ibaraki (Japan)

    2016-04-15

    Prompt gamma activation analysis using a thermal neutron-guided beam at Japan Atomic Energy Agency JRR-3M was applied for the precise determination of Si in silicon nitride ceramic reference materials [Japan Ceramic Reference Material (JCRM) R 003]. In this study, the standard addition method coupled with internal standard was used for the nondestructive determination of Si in the sample. Cadmium was used as internal standard to obtain the linear calibration curves and to compensate for the neutron beam variability. The analytical result of determining Si in JCRM R 003 silicon nitride fine powder ceramic reference materials using prompt gamma activation analysis was in good agreement with that obtained by classical gravimetric analysis. The relative expanded measurement uncertainty (k = 2) associated with the determined value was 2.4%.

  9. Towards the development of standard reference materials for soot measurements – Part 1: Tailored graphitized soot

    Directory of Open Access Journals (Sweden)

    T. Khokhlova

    2010-04-01

    Full Text Available The lack of standard reference materials for calibrating, troubleshooting and intercomparing instruments that measure the properties of black carbon, commonly referred to as soot, has been a major obstacle that hinders improved understanding of how climate and health is impacted by this ubiquitous component of the atmosphere. A different approach is offered here as a means of constructing precisely controlled material with fractions of organic carbon (OC on the surface of elemental carbon (EC whose structure reflects that of combustion particles found in the atmosphere. The proposed soot reference material (SRM uses elemental carbon as a basis substrate for surface coatings of organic compounds that are representative of main classes of organics identified in the coverage of soot produced by fossil fuel burning. A number of methods are used to demonstrate the quality and stability of the reference EC and SRM. Comparison of the nominal fraction of OC deposited on the EC substrate with the fraction measured with thermal/optical analysis (TOA shows excellent agreement. Application of this type of reference material for evaluating the different methods of carbon analysis may help resolve differences that currently exist between comparable measurement techniques when trying to separate OC and EC from ambient samples.

  10. Tailored graphitized soot as reference material for EC/OC measurement validation

    Directory of Open Access Journals (Sweden)

    O. Popovicheva

    2011-05-01

    Full Text Available The lack of standard reference materials for calibrating, troubleshooting and intercomparing techniques that measure the composition of black carbon, commonly referred to as soot, has been a major obstacle that hinders improved understanding of how climate and health is impacted by this ubiquitous component of the atmosphere. A different approach is offered here as a means of constructing precisely controlled material with fractions of organic carbon (OC on the surface of elemental carbon (EC whose structure reflects that of the combustion produced particles found in the atmosphere. The proposed soot reference material (SRM uses EC as a basis substrate for surface coatings of organic compounds that are representative of the main classes of organics identified in the coverage of soot produced by fossil fuel burning. A number of methods are used to demonstrate the quality and stability of the reference EC and SRM. Comparison of the nominal fraction of OC deposited on the EC substrate with the fraction measured with thermal/optical analysis (TOA shows excellent agreement. Application of this type of reference material for evaluating the different methods of carbon analysis may help resolve differences that currently exist between comparable measurement techniques when trying to separate OC and EC from ambient samples.

  11. Reference materials produced for a European metrological research project focussing on measurements of NORM.

    Science.gov (United States)

    Larijani, C; Pearce, A K; Regan, P H; Russell, B C; Jerome, S M; Crespo, M T; de Felice, P; Lutter, G; Maringer, F; Mazánová, M

    2017-08-01

    Reliable measurement of Naturally Occurring Radioactive Materials is of significance in order to comply with environmental regulations and for radiological protection purposes. This paper discusses the standardisation of three reference materials, namely sand, tuff and TiO2 to serve as quality control materials for traceability, method validation and instrument calibration. The sample preparation, material characterization via γ, α and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and the assignment of values for both the 4n (Thorium) and 4n+2 (Uranium) decay series are described. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  12. Feature Extraction and Automatic Material Classification of Underground Objects from Ground Penetrating Radar Data

    OpenAIRE

    Qingqing Lu; Jiexin Pu; Zhonghua Liu

    2014-01-01

    Ground penetrating radar (GPR) is a powerful tool for detecting objects buried underground. However, the interpretation of the acquired signals remains a challenging task since an experienced user is required to manage the entire operation. Particularly difficult is the classification of the material type of underground objects in noisy environment. This paper proposes a new feature extraction method. First, discrete wavelet transform (DWT) transforms A-Scan data and approximation coefficient...

  13. Evaluation of potential emission spectra for the reliable classification of fluorescently coded materials

    Science.gov (United States)

    Brunner, Siegfried; Kargel, Christian

    2011-06-01

    The conservation and efficient use of natural and especially strategic resources like oil and water have become global issues, which increasingly initiate environmental and political activities for comprehensive recycling programs. To effectively reutilize oil-based materials necessary in many industrial fields (e.g. chemical and pharmaceutical industry, automotive, packaging), appropriate methods for a fast and highly reliable automated material identification are required. One non-contacting, color- and shape-independent new technique that eliminates the shortcomings of existing methods is to label materials like plastics with certain combinations of fluorescent markers ("optical codes", "optical fingerprints") incorporated during manufacture. Since time-resolved measurements are complex (and expensive), fluorescent markers must be designed that possess unique spectral signatures. The number of identifiable materials increases with the number of fluorescent markers that can be reliably distinguished within the limited wavelength band available. In this article we shall investigate the reliable detection and classification of fluorescent markers with specific fluorescence emission spectra. These simulated spectra are modeled based on realistic fluorescence spectra acquired from material samples using a modern VNIR spectral imaging system. In order to maximize the number of materials that can be reliably identified, we evaluate the performance of 8 classification algorithms based on different spectral similarity measures. The results help guide the design of appropriate fluorescent markers, optical sensors and the overall measurement system.

  14. Assessment of international reference materials for isotope-ratio analysis (IUPAC Technical Report)

    Science.gov (United States)

    Brand, Willi A.; Coplen, Tyler B.; Vogl, Jochen; Rosner, Martin; Prohaska, Thomas

    2014-01-01

    Since the early 1950s, the number of international measurement standards for anchoring stable isotope delta scales has mushroomed from 3 to more than 30, expanding to more than 25 chemical elements. With the development of new instrumentation, along with new and improved measurement procedures for studying naturally occurring isotopic abundance variations in natural and technical samples, the number of internationally distributed, secondary isotopic reference materials with a specified delta value has blossomed in the last six decades to more than 150 materials. More than half of these isotopic reference materials were produced for isotope-delta measurements of seven elements: H, Li, B, C, N, O, and S. The number of isotopic reference materials for other, heavier elements has grown considerably over the last decade. Nevertheless, even primary international measurement standards for isotope-delta measurements are still needed for some elements, including Mg, Fe, Te, Sb, Mo, and Ge. It is recommended that authors publish the delta values of internationally distributed, secondary isotopic reference materials that were used for anchoring their measurement results to the respective primary stable isotope scale.

  15. A feasibility study for producing an egg matrix candidate reference material for the polyether ionophore salinomycin.

    Science.gov (United States)

    Ferreira, Rosana Gomes; Monteiro, Mychelle Alves; Pereira, Mararlene Ulberg; da Costa, Rafaela Pinto; Spisso, Bernardete Ferraz; Calado, Veronica

    2016-08-01

    The aim of this work was to study the feasibility of producing an egg matrix candidate reference material for salinomycin. Preservation techniques investigated were freeze-drying and spray drying dehydration. Homogeneity and stability studies of the produced batches were conducted according to ISO Guides 34 and 35. The results showed that all produced batches were homogeneous and both freeze-drying and spray drying techniques were suitable for matrix dehydrating, ensuring the material stability. In order to preserve the material integrity, it must be transported within the temperature range of -20 up to 25°C. The results constitute an important step towards the development of an egg matrix reference material for salinomycin is possible. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Reference material for natural radionuclides in glass designed for underground experiments

    CERN Document Server

    Povinec, P P; Busto, J; Cerna, C; Degering, D; Hamajima, Y; Holy, K; Hult, M; Jeskovsky, M; Koehler, M; Kovacik, A; Laubenstein, M; Loaiza, P; Mamedov, F; Marquet, C; Mott, J; Mullerova, M; Perrot, F; Piquemal, F; Reyss, J -L; Saakyan, R; Simgen, H; Soule, B; Stanicek, J; Sykora, I; Stekl, I

    2015-01-01

    A reference material designed for the determination of natural radionuclides in solid samples (glass pellets) is described and the results of certification are presented. The material has been certified for 7 natural radionuclides (40K, 226Ra, 228Ra, 228Th, 232Th, 235U and 238U). An information value is given for 210Pb. Radon (222Rn) emanation experiments showed results comparable within participating laboratories, however, the number of data and precision was too low to carry out a certification process. The reference material may be used for quality management of analytical laboratories engaged in the high-sensitive analysis of radionuclides in the construction materials of detectors placed in ultra low background underground laboratories.

  17. PAHs in baby food: assessment of three different processing techniques for the preparation of reference materials.

    Science.gov (United States)

    Huertas-Pérez, José Fernando; Bordajandi, Luisa R; Sejerøe-Olsen, Berit; Emteborg, Håkan; Baù, Andrea; Schimmel, Heinz; Dabrio, Marta

    2015-04-01

    A feasibility study for producing a matrix reference material for selected polycyclic aromatic hydrocarbons (PAHs) in baby food is reported. A commercially available baby food, containing carrots, potatoes, tomato, white beans and meat, was spiked with the so-called 15 + 1 PAHs included in the PAHs priority list for food of the EU, at a mass fraction level of 1 μg/kg. The contaminated baby food was further processed by autoclaving, freezing or freeze drying. The homogeneity of the three materials (bottle-to-bottle variation) and their short-term (4 weeks) and long-term (18 months) stability at different temperatures were assessed. To this end, an analytical method based on a solid-liquid extraction followed by cleaning up with gel permeation chromatography (GPC) and solid phase extraction (SPE) and GC-IDMS determination, was validated in-house. It could be demonstrated that the procedure fulfilled the demands for application to the homogeneity and isochronous stability studies for the candidate reference materials targeted here. All three materials proved to be sufficiently homogeneous for the intended use. Measurements on the autoclaved material provided the most promising results in terms of envisaged shelf life, although freeze drying was also found to be a suitable processing technique for most of the investigated PAHs. These results are an important step towards the development of a matrix reference material for PAHs in a processed food matrix in a presentation very similar to routine samples.

  18. Homogeneity study of a corn flour laboratory reference material candidate for inorganic analysis.

    Science.gov (United States)

    Dos Santos, Ana Maria Pinto; Dos Santos, Liz Oliveira; Brandao, Geovani Cardoso; Leao, Danilo Junqueira; Bernedo, Alfredo Victor Bellido; Lopes, Ricardo Tadeu; Lemos, Valfredo Azevedo

    2015-07-01

    In this work, a homogeneity study of a corn flour reference material candidate for inorganic analysis is presented. Seven kilograms of corn flour were used to prepare the material, which was distributed among 100 bottles. The elements Ca, K, Mg, P, Zn, Cu, Fe, Mn and Mo were quantified by inductively coupled plasma optical emission spectrometry (ICP OES) after acid digestion procedure. The method accuracy was confirmed by analyzing the rice flour certified reference material, NIST 1568a. All results were evaluated by analysis of variance (ANOVA) and principal component analysis (PCA). In the study, a sample mass of 400mg was established as the minimum mass required for analysis, according to the PCA. The between-bottle test was performed by analyzing 9 bottles of the material. Subsamples of a single bottle were analyzed for the within-bottle test. No significant differences were observed for the results obtained through the application of both statistical methods. This fact demonstrates that the material is homogeneous for use as a laboratory reference material. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Development of a new cucumber reference material for pesticide residue analysis: feasibility study for material processing, homogeneity and stability assessment.

    Science.gov (United States)

    Grimalt, Susana; Harbeck, Stefan; Shegunova, Penka; Seghers, John; Sejerøe-Olsen, Berit; Emteborg, Håkan; Dabrio, Marta

    2015-04-01

    The feasibility of the production of a reference material for pesticide residue analysis in a cucumber matrix was investigated. Cucumber was spiked at 0.075 mg/kg with each of the 15 selected pesticides (acetamiprid, azoxystrobin, carbendazim, chlorpyrifos, cypermethrin, diazinon, (α + β)-endosulfan, fenitrothion, imazalil, imidacloprid, iprodione, malathion, methomyl, tebuconazole and thiabendazole) respectively. Three different strategies were considered for processing the material, based on the physicochemical properties of the vegetable and the target pesticides. As a result, a frozen spiked slurry of fresh cucumber, a spiked freeze-dried cucumber powder and a freeze-dried cucumber powder spiked by spraying the powder were studied. The effects of processing and aspects related to the reconstitution of the material were evaluated by monitoring the pesticide levels in the three materials. Two separate analytical methods based on LC-MS/MS and GC-MS/MS were developed and validated in-house. The spiked freeze-dried cucumber powder was selected as the most feasible material and more exhaustive studies on homogeneity and stability of the pesticide residues in the matrix were carried out. The results suggested that the between-unit homogeneity was satisfactory with a sample intake of dried material as low as 0.1 g. A 9-week isochronous stability study was undertaken at -20 °C, 4 °C and 18 °C, with -70 °C designated as the reference temperature. The pesticides tested exhibited adequate stability at -20 °C during the 9-week period as well as at -70 °C for a period of 18 months. These results constitute a good basis for the development of a new candidate reference material for selected pesticides in a cucumber matrix.

  20. Doorways III: Teacher Reference Materials. On School-Related Gender-Based Violence Prevention and Response

    Science.gov (United States)

    US Agency for International Development, 2009

    2009-01-01

    The Doorways training program was designed by the U.S. Agency for International Development (USAID)-funded Safe Schools Program (Safe Schools) to enable teachers, community members and students to prevent and respond to school-related gender-based violence (SRGBV). This booklet, "Doorways III: Teacher Reference Materials on School-Related…

  1. A certified reference material for radionuclides in the water sample from Irish Sea (IAEA-443)

    DEFF Research Database (Denmark)

    Pham, M.K.; Betti, M.; Povinec, P.P.

    2011-01-01

    A new certified reference material (CRM) for radionuclides in sea water from the Irish sea (IAEA-443) is described and the results of the certification process are presented. Ten radionuclides (3H, 40K, 90Sr, 137Cs, 234U, 235U, 238U, 238Pu, 239+240Pu and 241Am) have been certified, and information...

  2. Future needs and requirements for AMS C-14 standards and reference materials

    NARCIS (Netherlands)

    Scott, EM; Boaretto, E; Bryant, C; Cook, GT; Gulliksen, S; Harkness, DD; Heinemeier, J; McGee, E; Naysmith, P; Possnert, G; van der Plicht, H; van Strydonck, M; Cook, Gordon T.

    2004-01-01

    C-14 measurement uses a number of standards and reference materials with different properties. Historically the absolute calibration of C-14 measurement was tied to 1890 wood, through the 'primary' standard of NBS-OxI (produced by the National Bureau of Standards, now NIST - National Institute of St

  3. Reference Materials for Food and Nutrition Metrology: Past, Present and Future

    Science.gov (United States)

    Establishment of a metrology-based measurement system requires the solid foundation of traceability of measurements to available, appropriate certified reference materials (CRM). In the early 1970’s the first “biological” RM of Bowens Kale, as well as Orchard Leaves and Bovine Liver SRMs, from the ...

  4. Sources of Braille Reading Materials. Reference Circular No. 86-2.

    Science.gov (United States)

    Redmond, Linda, Comp.

    This reference circular lists sources of braille books available for loan, purchase, rental, or free (give-away) distribution. Divided into four sections, it includes general sources of braille books, sources of specialized braille materials, the major braille presses, and resources for further information about braille books and magazines.…

  5. Speciation of dimethylarsinyl-riboside derivatives (arsenosugars) in marine reference materials by HPLC-ICP-MS

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt

    1995-01-01

    (cf. Table 2) were present in shellfish certified reference materials (CRMs) and in a lobster hepatopancreas CRM. The concentration of the two arsenosugars in the shellfish samples amounts to 18% of the total arsenic as compared to arsenobetaine at 9–13% and dimethylarsinate at 4–9% of the total...

  6. Evaluation of New Geological Reference Materials for U-Series Measurements

    Science.gov (United States)

    Denton, J. S.; Goldstein, S. J.; Nunn, A. J.; Ui Chearnaigh, K.; Amato, R.; Murrell, M. T.

    2012-12-01

    Uranium-series analytical measurements are widely used in geochemistry, geochronology, paleoclimatology, volcanology, environmental risk assessment and other fields. Recent advances in high-resolution, rapid, in situ microanalytical techniques e.g. LA-ICP-MS and SIMS present numerous opportunities for the geoanalytical community. As with other analytical techniques, the quality of the elemental concentration and isotopic data obtained through microanalytical techniques is dependent on the accurate characterization of suitable reference materials. Even for the case of fs-laser ablation applications, a range of well-characterized standards are required for high precision U-series work. Advances have been made in evaluating existing standard reference materials for U-series isotopic analysis, but this work is ongoing as more reference materials become available. In this study we present MC-TIMS and MC-ICP-MS results for uranium and thorium isotopic ratios and elemental concentrations measured in a suite of newly available Chinese Geological Standard Glasses (CGSG) designed for microanalysis. These glasses exhibit a range of chemical compositions including basalt, syenite, andesite and a soil. U concentrations for these glasses range from ≈2 to 14 μg/g and [Th]/[U] ratios range from ≈4 to 6. Uranium and thorium concentration and isotopic data will also be presented for rhyolitic obsidian from Macusani, SE Peru, which can be used as a rhyolitic reference material. These high-precision and high-accuracy ratios, from a suite of standards that exhibit a range of natural, non-basaltic compositions, will complement data from existing standards and expand the catalogue of reference materials that are appropriate for in situ U-series work. These results can be used to assess the performance of microanalytical techniques and will facilitate inter-laboratory comparison of data within the broader geoscience community.

  7. Development of a Certified Reference Material for myeloperoxidase-anti-neutrophil cytoplasmic autoantibodies (MPO-ANCA).

    Science.gov (United States)

    Monogioudi, Evanthia; Hutu, Dana Petronela; Martos, Gustavo; Sheldon, Joanna; Schimmel, Heinz; Meroni, Pier Luigi; Zegers, Ingrid

    2016-06-01

    A serum Certified Reference Material (CRM) for supporting reliable autoimmune diagnostics was recently released by the Institute for Reference Materials and Measurements (IRMM) of the Joint Research Centre of the European Commission. It was produced in collaboration with a Working Group on the Harmonisation of Autoimmune Tests of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC WG-HAT). This material is aimed at facilitating the standardisation of measurements of anti-myeloperoxidase immunoglobulin G antibodies. The CRM could be used as a common calibrant by clinicians and manufacturers thereby significantly improving the comparability of results from commercial immunoassays used for IgG anti-MPO measurements. This paper provides information on the new CRM and its intended use.

  8. Platinum stable isotope analysis of geological standard reference materials by double-spike MC-ICPMS

    DEFF Research Database (Denmark)

    Creech, John Benjamin; Baker, J. A.; Handler, M. R.

    2014-01-01

    We report a method for the chemical purification of Pt from geological materials by ion-exchange chromatography for subsequent Pt stable isotope analysis by multiple-collector inductively coupled plasma mass spectrometry (MC-ICPMS) using a Pt-Pt double-spike to correct for instrumental mass bias...... (Creech et al., 2013, J. Anal. At. Spectrom. 28, 853-865). The reproducibility in natural samples is evaluated by processing multiple replicates of four standard reference materials, and is conservatively taken to be ca. ±0.088 (2sd). Pt stable isotope data for the full set of reference materials have....... Double-spiking of samples was carried out prior to digestion and chemical separation to correct for any mass-dependent fractionation that may occur due to incomplete recovery of Pt. Samples were digested using a NiS fire assay method, which pre-concentrates Pt into a metallic bead that is readily...

  9. Certification of a meat reference material based on a collaborative study

    Directory of Open Access Journals (Sweden)

    Claudia Marcela Salazar Arzate

    2013-01-01

    Full Text Available Through a collaborative project, comparison studies were carried out to improve measurement capabilities of participating laboratories, supporting them to produce, characterize and distribute reference materials in the food sector. The project was planned in four annual stages (milk, water, meat and grains. The third stage aimed specifically to quantify and certify the nutritional content of the parameters (nitrogen, fat, sodium and potassium of a batch candidate as Certified Reference Material (CRM of canned beef. This study was conducted in collaboration between several National Metrology Institutes (NMIs and/or collaborating laboratories, which, once identified the possible causes of variability or bias in the measurements, as well as the opportunities of improvement, achieved the certification of the material beef. The CRM was distributed among the participants to cover the needs of the food industry of meat products and testing laboratories in their respective countries.

  10. Synthetic Reference Materials Based on Polymer Films for the Control of Welding Fumes Composition

    Science.gov (United States)

    Kuznetsova, O. V.; Kuznetsova, A. N.; Begunova, L. A.

    2017-04-01

    Analysis of the current hygienic situation in the welding production showed that the intensification of welding processes involves the deterioration of air quality, which negatively affects the welders health. Welders are exposed to a variety of metal fumes, including manganese that may elevate the risk for neurological diseases. The control of metals concentration in the air of the working area is difficult due to the lack of reference materials. The creation of reference materials of welding fumes composition is a challenge due to chemical characteristics of their physical properties. Synthetic samples in a form of the polymer film containing powder particles of welding fumes were create. Studies on the selection of the polymer were done. Experiments proved that the qualitative materials of synthetic welding fumes are obtained by using polyvinyl alcohol. The metals concentration in the samples was determined by X-ray fluorescence analysis. The obtained data demonstrates indirectly the uniform distribution of welding fumes powder particles on the polymer film.

  11. Diffusion-controlled toluene reference material for VOC emissions testing: international interlaboratory study.

    Science.gov (United States)

    Howard-Reed, Cynthia; Liu, Zhe; Cox, Steven; Leber, Dennis; Samarov, Dan; Little, John C

    2014-04-01

    The measurement of volatile organic compound (VOC) emissions from building products and materials by manufacturers and testing laboratories, and the use of the test results for labeling programs, continue to expand. One issue that hinders wide acceptance for chamber product testing is the lack of a reference material to validate test chamber performance. To meet this need, the National Institute of Standards and Technology (NIST) and Virginia Tech (VT) have developed a prototype reference material that emits a single VOC similar to the emissions of a diffusion-controlled building product source with a dynamic emissions profile. The prototype material has undergone extensive testing at NIST and a pilot interlaboratory study (ILS) with four laboratories. The next development step is an evaluation of the prototype source in multiple-sized chambers of 14 laboratories in seven countries. Each laboratory was provided duplicate specimens and a test protocol. Study results identified significant issues related to the need to store the source at a subzero Celsius temperature until tested and possible inconsistencies in large chambers. For laboratories using a small chamber and meeting all the test method criteria, the results were very encouraging with relative standard deviations ranging from 5% to 10% across the laboratories. Currently, the chamber performance of laboratories conducting product VOC emissions testing is assessed through interlaboratory studies (ILS) using a source with an unknown emission rate. As a result, laboratory proficiency can only be based on the mean and standard deviation of emission rates measured by the participating ILS laboratories. A reference material with a known emission rate has the potential to provide an independent assessment of laboratory performance as well as improve the quality of interlaboratory studies. Several international laboratories with different chamber testing systems demonstrated the ability to measure the emission rate

  12. Classification-free threat detection based on material-science-informed clustering

    Science.gov (United States)

    Yuan, Siyang; Wolter, Scott D.; Greenberg, Joel A.

    2017-05-01

    X-ray diffraction (XRD) is well-known for yielding composition and structural information about a material. However, in some applications (such as threat detection in aviation security), the properties of a material are more relevant to the task than is a detailed material characterization. Furthermore, the requirement that one first identify a material before determining its class may be difficult or even impossible for a sufficiently large pool of potentially present materials. We therefore seek to learn relevant composition-structure-property relationships between materials to enable material-identification-free classification. We use an expert-informed, data-driven approach operating on a library of XRD spectra from a broad array of stream of commerce materials. We investigate unsupervised learning techniques in order to learn about naturally emergent groupings, and apply supervised learning techniques to determine how well XRD features can be used to separate user-specified classes in the presence of different types and degrees of signal degradation.

  13. Development of NIST standard reference material 2373: Genomic DNA standards for HER2 measurements

    Directory of Open Access Journals (Sweden)

    Hua-Jun He

    2016-06-01

    Full Text Available NIST standard reference material (SRM 2373 was developed to improve the measurements of the HER2 gene amplification in DNA samples. SRM 2373 consists of genomic DNA extracted from five breast cancer cell lines with different amounts of amplification of the HER2 gene. The five components are derived from the human cell lines SK-BR-3, MDA-MB-231, MDA-MB-361, MDA-MB-453, and BT-474. The certified values are the ratios of the HER2 gene copy numbers to the copy numbers of selected reference genes DCK, EIF5B, RPS27A, and PMM1. The ratios were measured using quantitative polymerase chain reaction and digital PCR, methods that gave similar ratios. The five components of SRM 2373 have certified HER2 amplification ratios that range from 1.3 to 17.7. The stability and homogeneity of the reference materials were shown by repeated measurements over a period of several years. SRM 2373 is a well characterized genomic DNA reference material that can be used to improve the confidence of the measurements of HER2 gene copy number.

  14. Nanomaterials for environmental studies: Classification, reference material issues, and strategies for physico-chemical characterisation

    NARCIS (Netherlands)

    Stone, V.; Nowack, B.; Baun, A.; Brink, van den N.W.; Kammer, von den F.; Dusinska, M.; Handy, R.; Hankin, S.; Hassellöv, M.; Joner, E.; Fernandes, T.F.

    2010-01-01

    NanoImpactNet is a European Commission Framework Programme 7 (FP7) funded project that provides a forum for the discussion of current opinions on nanomaterials in relation to human and environmental issues. In September 2008, in Zurich, a NanoImpactNet environmental workshop focused on three key que

  15. Present status and strategic plan for the stable isotope reference materials at the IAEA.

    Science.gov (United States)

    Assonov, Sergey; Groening, Manfred

    2016-04-01

    The presentation will give the overview of the stable isotope reference materials (SI-RMs) under distribution by the IAEA, its stable isotope laboratory and capacities related to material testing & production as well as future plans. Historically, most of the IAEA reference materials were produced and made available via collaborations with expert stable isotope laboratories worldwide. The IAEA plans include several directions as follows: • Maintaining the scale-defining SI-RMs at the highest level and introducing adequate replacements when needed; • Monitoring existing SI-RMs for any potential alteration(s) and of isotopic values assigned; • Identifying and then addressing the needs for new SI-RMs, with the priority to address the most critical applications (environmental and climate related applications, human health, food safety studies) and newly emerging analytical isotope techniques; • Performing all measurements aimed for characterisation of new SI-RMs and the corresponding uncertainty evaluation in accordance to the latest metrological concepts; • Promoting metrological approaches on traceability and uncertainty evaluation in every day practice of stable isotope measurements; • Expanding the IAEA capacities for SI-RMs by (i) planning a renewed laboratory at IAEA; (ii) enlarging collaboration with expert laboratories aimed to help IAEA in production and characterisation of new SI-RMs. These major directions will help to address the increasing demand for Stable Isotope Reference Materials.

  16. Material classification and automatic content enrichment of images using supervised learning and knowledge bases

    Science.gov (United States)

    Mallepudi, Sri Abhishikth; Calix, Ricardo A.; Knapp, Gerald M.

    2011-02-01

    In recent years there has been a rapid increase in the size of video and image databases. Effective searching and retrieving of images from these databases is a significant current research area. In particular, there is a growing interest in query capabilities based on semantic image features such as objects, locations, and materials, known as content-based image retrieval. This study investigated mechanisms for identifying materials present in an image. These capabilities provide additional information impacting conditional probabilities about images (e.g. objects made of steel are more likely to be buildings). These capabilities are useful in Building Information Modeling (BIM) and in automatic enrichment of images. I2T methodologies are a way to enrich an image by generating text descriptions based on image analysis. In this work, a learning model is trained to detect certain materials in images. To train the model, an image dataset was constructed containing single material images of bricks, cloth, grass, sand, stones, and wood. For generalization purposes, an additional set of 50 images containing multiple materials (some not used in training) was constructed. Two different supervised learning classification models were investigated: a single multi-class SVM classifier, and multiple binary SVM classifiers (one per material). Image features included Gabor filter parameters for texture, and color histogram data for RGB components. All classification accuracy scores using the SVM-based method were above 85%. The second model helped in gathering more information from the images since it assigned multiple classes to the images. A framework for the I2T methodology is presented.

  17. Statistical Analysis of a Round-Robin Measurement Survey of Two Candidate Materials for a Seebeck Coefficient Standard Reference Material.

    Science.gov (United States)

    Lu, Z Q J; Lowhorn, N D; Wong-Ng, W; Zhang, W; Thomas, E L; Otani, M; Green, M L; Tran, T N; Caylor, C; Dilley, N R; Downey, A; Edwards, B; Elsner, N; Ghamaty, S; Hogan, T; Jie, Q; Li, Q; Martin, J; Nolas, G; Obara, H; Sharp, J; Venkatasubramanian, R; Willigan, R; Yang, J; Tritt, T

    2009-01-01

    In an effort to develop a Standard Reference Material (SRM™) for Seebeck coefficient, we have conducted a round-robin measurement survey of two candidate materials-undoped Bi2Te3 and Constantan (55 % Cu and 45 % Ni alloy). Measurements were performed in two rounds by twelve laboratories involved in active thermoelectric research using a number of different commercial and custom-built measurement systems and techniques. In this paper we report the detailed statistical analyses on the interlaboratory measurement results and the statistical methodology for analysis of irregularly sampled measurement curves in the interlaboratory study setting. Based on these results, we have selected Bi2Te3 as the prototype standard material. Once available, this SRM will be useful for future interlaboratory data comparison and instrument calibrations.

  18. Material Classification by Analysis of Prompt Photon Spectra Induced by 14-Mev Neutrons

    Science.gov (United States)

    Barzilov, Alexander; Novikov, Ivan

    Neutron based technologies are widely used in the field of bulk material analysis. These methods employ characteristic prompt gamma rays induced by a neutron probe for classification of the interrogated object using the elemental parameters extracted from the spectral data. Automatic data analysis and material classification algorithms are required for applications where access to nuclear spectroscopy expertise is limited and/or the autonomous robotic operation is necessary. Data obtained with neutron based systems differ from elemental composition evaluations based on chemical formulae due to statistical nature of nuclear reactions, presence of shielding and cladding, and other environmental conditions. Experimental data that are produced by the spectral decomposition can be expressed graphically as sets of overlapping classes in a multidimensional space of measured elemental intensities. To discriminate between classes of various materials, decision-tree and pattern recognition algorithms were studied. Results of application of these methods to data sets obtained for a pulsed 14-MeV neutron generator based active interrogation system are discussed.

  19. Characterization of brown rice as a certified reference material for Fukushima accident-related radioactivity measurements.

    Science.gov (United States)

    Unno, Yasuhiro; Hachinohe, Mayumi; Hamamatsu, Shioka; Todoriki, Setsuko; Yunoki, Akira; Miura, Tsutomu

    2014-05-01

    We developed a certified reference material of brown rice to measure radioactivity from the Fukushima Daiichi Nuclear Power Plant accident. The rice was planted in the spring of 2011, just after the Fukushima accident occurred, and it was harvested in the autumn of 2011. The certified value of radioactivity concentration in the rice was 33.6 Bq kg(-1) of Cs-134 and 51.8 Bq kg(-1) of Cs-137 on August 1, 2012. The reference material is being widely distributed by the National Metrology Institute of Japan. To determine the radioactivity and its uncertainties in the brown rice, we employed gamma-ray spectrometry with a high-purity germanium detector and Monte Carlo simulation.

  20. Development and certification of a coal fly ash certified reference material for selected polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Cao, X; Xu, X; Cui, W; Xi, Z

    2001-08-01

    The development and certification of a coal fly ash certified reference material (CRM) for polycyclic aromatic hydrocarbons (PAH) is described; this is the first natural matrix CRM for organic environmental analysis in China. The homogeneity and stability of this material have been tested by HPLC. The concentrations of several PAH were determined by use of two independent, different methods--solvent extraction-HPLC analysis with UV detection coupled with fluorescence detection (FLD) and solvent extraction, isolation with a silica column, and GC analysis with flame ionization detection (FID). Five certified values were determined: phenanthrene 7.1 +/- 2.6 microg g(-1), anthracene 2.0 +/- 0.8 microg g(-1), fluoranthene 7.4 +/- 1.9 microg g(-1), pyrene 7 +/- 2 microg g(-1), and benzo[a]pyrene 1.3 +/- 0.3 microg g(-1). Reference values for several other PAH are also suggested.

  1. Problematic issues of the development of reference materials of composition and properties for aircraft industry

    Directory of Open Access Journals (Sweden)

    A. N. Lutsenko

    2016-01-01

    Full Text Available Considered problematic issues of the development of reference materials (RMs for aircraft industry. The focus is on the methods for choosing the RM chemical composition and metallographic structure, and the use of different technologies for their production with high intra- and between item homogeneity. Considered problematic issues of the RM program, shows the need to expand and optimize the range of RMs. The present work is performed within framework of the integrated research concept 2.1. "Fundamentally oriented research" ("Strategic concepts of development of materials and technologies for their processing for the period up to 2030".

  2. RBS as a new primary direct reference method for measuring quantity of material

    Science.gov (United States)

    Jeynes, C.

    2017-09-01

    The quantity of material in thin films can be measured reliably, non-destructively, and at an absolute traceable accuracy with a combined standard uncertainty of 1% by Rutherford backscattering spectrometry (RBS). We have demonstrated a measurement protocol for the determination of quantity of material by RBS that has been accredited at this accuracy to the ISO 17025 standard by the United Kingdom Accreditation Service (UKAS). The method is entirely traceable to SI units relying on no artefacts, and thus qualifies as a primary direct reference method as defined by the ISO Guide 35:1985 (paragraph 9.4.1).

  3. Candidate coffee reference material for element content: production and certification schemes adopted at CENA/USP

    Energy Technology Data Exchange (ETDEWEB)

    Tagliaferro, Fabio Sileno; Fernandes, Elisabete A. de Nadai; Bacchi, Marcio Arruda; Franca, Elvis Joacir de [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil). Lab. de Radioisotopos], e-mail: fabiotag@cena.usp.br, e-mail: lis@cena.usp.br, e-mail: mabacchi@cena.usp.br, e-mail: ejfranca@cena.usp.br; Bode, Peter; Bacchi, Marcio Arruda; Franca, Elvis Joacir de [Delft University of Technology, Delft (Netherlands). Interfaculty Reactor Inst.], e-mail: P.Bode@iri.tudelft.nl

    2003-07-01

    Certified reference materials (CRMs) play a fundamental role in analytical chemistry establishing the traceability of measurement results and assuring accuracy and reliability. In spite of the huge importance of measurements in the food sector, Brazil does not produce CRMs to supply the demand. Consequently the acquisition of CRMs depends on imports at high costs. The coffee sector needs CRMs, however there is no material that represents the coffee composition. Since 1998, the Laboratorio de Radioisotopos (LRi) of CENA/USP has been involved in analysis of coffee. During this period, knowledge has been accumulated about several aspects of coffee, such as system of cultivation, elemental composition, homogeneity of the material, possible contaminants and physical properties of beans. Concomitantly, LRi has concentrated efforts in the field of metrology in chemistry, and now all this expertise is being used as the basis for the production of a coffee certified reference material (CRM) for inorganic element content. The scheme developed for the preparation and certification of coffee RM relies on the ISO Guides 34 and 35. The approaches for selection, collection and preparation of the material, moisture determination method, homogeneity testing, certification and long-term stability testing are discussed and a time frame for the expected accomplishments is provided. (author)

  4. Measurement of polybrominated diphenyl ethers in environmental matrix standard reference materials

    Energy Technology Data Exchange (ETDEWEB)

    Stapleton, H.; Schantz, M.; Wise, S. (National Institute of Standards and Technology)

    2004-09-15

    Polybrominated diphenyl ethers (PBDEs) are a class of emerging contaminants of concern as many studies have now demonstrated that these compounds are bioaccumulative, persistent and increasing in concentration in the environment. PBDEs are being detected in almost every environmental sample examined, and they have even been measured in samples collected in the Arctic, further demonstrating their persistence and potential for long range transport. More and more studies are continuing to examine the fate and transport of these flame retardant compounds in environmental samples and as such, reference materials are needed to provide quality control on these measurements. The National Institute of Standards and Technology (NIST) supports a national Standard Reference Material (SRM) program for measurement of organic contaminants such as PCBs, PAHs and chlorinated pesticides in environmental matrices. This current study was undertaken to provide reference measurements for PBDEs in selected SRMs that are currently used by various laboratories throughout the United States. These SRMs include matrices such as marine mammal blubber, lake trout tissue, mussel tissue, sediment, house dust and human serum. We report here reference values for 22 PBDE congeners that have been quantified in these seven types of SRMs.

  5. Software Management Environment (SME) release 9.4 user reference material

    Science.gov (United States)

    Hendrick, R.; Kistler, D.; Manter, K.

    1992-01-01

    This document contains user reference material for the Software Management Environment (SME) prototype, developed for the Systems Development Branch (Code 552) of the Flight Dynamics Division (FDD) of Goddard Space Flight Center (GSFC). The SME provides an integrated set of management tools that can be used by software development managers in their day-to-day management and planning activities. This document provides an overview of the SME, a description of all functions, and detailed instructions concerning the software's installation and use.

  6. Stability of aflatoxin B1 in animal feed candidate reference materials

    NARCIS (Netherlands)

    Roos, A.H.; Mazijk, van R.J.; Tuinstra, L.G.M.T.; Huf, F.A.

    1991-01-01

    Two candidate reference materials animal feed were stored at a temperature of -18°C, 4 C, 20°C and 37°C. The stability of aflatoxin B1 was studied duringa period of two years. A significant decrease in the aflatoxin B1 content was measured in the samples stared at 20°C and 37°C. In the samples

  7. The role of adequate reference materials in density measurements in hemodialysis

    Science.gov (United States)

    Furtado, A.; Moutinho, J.; Moura, S.; Oliveira, F.; Filipe, E.

    2015-02-01

    In hemodialysis, oscillation-type density meters are used to measure the density of the acid component of the dialysate solutions used in the treatment of kidney patients. An incorrect density determination of this solution used in hemodialysis treatments can cause several and adverse events to patients. Therefore, despite the Fresenius Medical Care (FME) tight control of the density meters calibration results, this study shows the benefits of mimic the matrix usually measured to produce suitable reference materials for the density meter calibrations.

  8. Classification of plastic materials by imaging laser-induced ablation plumes

    Science.gov (United States)

    Negre, Erwan; Motto-Ros, Vincent; Pelascini, Frederic; Yu, Jin

    2016-08-01

    A method of rapid classification and identification of plastic materials has been studied in this work. Such method is based on fast spectroscopic imagery of laser-induced ablation plume on plastics to be analyzed. More specifically, a classification schema has been developed first according to the nature of the CC bonds which characterize the polymer matrix. Our results show that the spatial distribution and the evolution of the molecular species in the ablation plume, such as C2 and CN, exhibit clear different behaviors for polymers without any native CC bond, with CC single bonds or with CC double bonds respectively. Therefore the morphological parameters of the populations of the molecular species extracted from the time-resolved spectroscopic images of the plumes provide efficient indicators to classify the polymers characterized by the above mentioned different kinds of CC bonds. When dealing with different polymers with the same kind of CC bond, CC single bond for instance, other indicators should be introduced to provide the further discrimination. Such indicators can be for example a specific native molecular bond other than CC bonds, CN for example, the total emission intensity of which may exhibit specific time evolution. The robustness of the developed classification schema has been then studied with respect to two of the most frequently used additives in plastics fabrication, graphite and titanium. Our results show a negligible influence of these additives in the morphology of the populations of the molecular species when such additives are mixed into the polymer matrix with the percentages usually used in plastics productions, which demonstrates the validity of the developed classification schema for plastics.

  9. Hierarchy concepts: classification and preparation strategies for zeolite containing materials with hierarchical porosity.

    Science.gov (United States)

    Schwieger, Wilhelm; Machoke, Albert Gonche; Weissenberger, Tobias; Inayat, Amer; Selvam, Thangaraj; Klumpp, Michael; Inayat, Alexandra

    2016-06-13

    'Hierarchy' is a property which can be attributed to a manifold of different immaterial systems, such as ideas, items and organisations or material ones like biological systems within living organisms or artificial, man-made constructions. The property 'hierarchy' is mainly characterised by a certain ordering of individual elements relative to each other, often in combination with a certain degree of branching. Especially mass-flow related systems in the natural environment feature special hierarchically branched patterns. This review is a survey into the world of hierarchical systems with special focus on hierarchically porous zeolite materials. A classification of hierarchical porosity is proposed based on the flow distribution pattern within the respective pore systems. In addition, this review might serve as a toolbox providing several synthetic and post-synthetic strategies to prepare zeolitic or zeolite containing material with tailored hierarchical porosity. Very often, such strategies with their underlying principles were developed for improving the performance of the final materials in different technical applications like adsorptive or catalytic processes. In the present review, besides on the hierarchically porous all-zeolite material, special focus is laid on the preparation of zeolitic composite materials with hierarchical porosity capable to face the demands of industrial application.

  10. [Criticism of the gonioscopic classifications of the glaucoma: with particular reference to the classification issued by the European Glaucoma Society in 2008].

    Science.gov (United States)

    Bordeianu, Constantin Dan

    2014-01-01

    To critically analyze the gonioscopic classifications of glaucoma, especially of the classification issued by the European Glaucoma Society in 2008, in order to reveal its advantages and shortcomings. The paper tries to determine the extent to which this classification is clear (being based on a coherent and consistently followed set of criteria), is comprehensive (framing all forms of glaucoma), helps to understand the sickness (using a logical framing system), and facilitates therapeutic decision making (offering direct therapeutic suggestions). The paper shows that, compared with all the previous classifications, the 2008 European Glaucoma Society classification is one step ahead (in the way of classifying the group of secondary angle-closure glaucomas), two steps behind (in rejecting two useful categories of congenital glaucoma), and similar in several respects: that it is based on criticizable fundamental and secondary criteria that cannot cover all forms of sickness gathered at a particular crossing; that it uses several equally weighted criteria for one single crossing (division); that it frames one clinical entity in several clinical categories; that it does not reflect reality in some aspects; and that it does not offer direct therapeutic suggestions: after framing a case in a scheme built on the basis of gonioscopic observation, it requires a second stage of pathogenic analysis, so that the ophthalmologist is able to decide the correct treatment only in the third stage. This tortuous thinking pathway, with successive stages - that are not followed by all doctors, explains many of the erroneous therapeutic decisions. All these considerations justify the efforts to find a new classification, able to correct the abovementioned shortcomings.

  11. Consensus evaluation of radioactivity-in-soil reference materials in the context of an NPL Environmental Radioactivity Proficiency Test Exercise.

    Science.gov (United States)

    Dean, Julian; Collins, Sean; Garcia Miranda, Maria; Ivanov, Peter; Larijani, Cyrus; Woods, Selina

    2017-01-25

    The development of two radioactivity-in-soil reference materials is described - one for peat and one for soil with high sand content. Each bulk material was processed, subdivided and measured before being sent to participants in an NPL Environmental Radioactivity Proficiency Test Exercise. Activity concentrations of radionuclides in each material were determined by 'consensus' evaluations of participants' results using two weighted mean methods. The project demonstrated the use of such exercises in delivering reference materials to the user community.

  12. Developing a reference material for diffusion-controlled formaldehyde emissions testing.

    Science.gov (United States)

    Liu, Zhe; Liu, Xiaoyu; Zhao, Xiaomin; Cox, Steven S; Little, John C

    2013-11-19

    Formaldehyde, a known human carcinogen and mucous membrane irritant, is emitted from a variety of building materials and indoor furnishings. The drive to improve building energy efficiency by decreasing ventilation rates increases the need to better understand emissions from indoor products and to identify and develop lower emitting materials. To help meet this need, formaldehyde emissions from indoor materials are typically measured using environmental chambers. However, chamber testing results are frequently inconsistent and provide little insight into the mechanisms governing emissions. This research addresses these problems by (1) developing a reference formaldehyde emissions source that can be used to validate chamber testing methods for characterization of dynamic sources of formaldehyde emissions and (2) demonstrating that emissions from finite formaldehyde sources can be predicted using a fundamental mass-transfer model. Formaldehyde mass-transfer mechanisms are elucidated, providing practical approaches for developing diffusion-controlled reference materials that mimic actual sources. The fundamental understanding of emissions mechanisms can be used to improve emissions testing and guide future risk reduction actions.

  13. 230Th-234U Model-Ages of Some Uranium Standard Reference Materials

    Energy Technology Data Exchange (ETDEWEB)

    Williams, R W; Gaffney, A M; Kristo, M J; Hutcheon, I D

    2009-05-28

    The 'age' of a sample of uranium is an important aspect of a nuclear forensic investigation and of the attribution of the material to its source. To the extent that the sample obeys the standard rules of radiochronometry, then the production ages of even very recent material can be determined using the {sup 230}Th-{sup 234}U chronometer. These standard rules may be summarized as (a) the daughter/parent ratio at time=zero must be known, and (b) there has been no daughter/parent fractionation since production. For most samples of uranium, the 'ages' determined using this chronometer are semantically 'model-ages' because (a) some assumption of the initial {sup 230}Th content in the sample is required and (b) closed-system behavior is assumed. The uranium standard reference materials originally prepared and distributed by the former US National Bureau of Standards and now distributed by New Brunswick Laboratory as certified reference materials (NBS SRM = NBL CRM) are good candidates for samples where both rules are met. The U isotopic standards have known purification and production dates, and closed-system behavior in the solid form (U{sub 3}O{sub 8}) may be assumed with confidence. We present here {sup 230}Th-{sup 234}U model-ages for several of these standards, determined by isotope dilution mass spectrometry using a multicollector ICP-MS, and compare these ages with their known production history.

  14. Statistical Analysis of a Round-Robin Measurement Survey of Two Candidate Materials for a Seebeck Coefficient Standard Reference Material

    Directory of Open Access Journals (Sweden)

    Lu, Z. Q. J.

    2009-01-01

    Full Text Available In an effort to develop a Standard Reference Material (SRM™ for Seebeck coefficient, we have conducted a round-robin measurement survey of two candidate materials—undoped Bi2Te3 and Constantan (55 % Cu and 45 % Ni alloy. Measurements were performed in two rounds by twelve laboratories involved in active thermoelectric research using a number of different commercial and custom-built measurement systems and techniques. In this paper we report the detailed statistical analyses on the interlaboratory measurement results and the statistical methodology for analysis of irregularly sampled measurement curves in the interlaboratory study setting. Based on these results, we have selected Bi2Te3 as the prototype standard material. Once available, this SRM will be useful for future interlaboratory data comparison and instrument calibrations.

  15. Reliable classification of moving waste materials with LIBS in concrete recycling.

    Science.gov (United States)

    Xia, Han; Bakker, M C M

    2014-03-01

    Effective discrimination between different waste materials is of paramount importance for inline quality inspection of recycle concrete aggregates from demolished buildings. The moving targeted materials in the concrete waste stream are wood, PVC, gypsum block, glass, brick, steel rebar, aggregate and cement paste. For each material, up to three different types were considered, while thirty particles of each material were selected. Proposed is a reliable classification methodology based on integration of the LIBS spectral emissions in a fixed time window, starting from the deployment of the laser shot. PLS-DA (multi class) and the hybrid combination PCA-Adaboost (binary class) were investigated as efficient classifiers. In addition, mean centre and auto scaling approaches were compared for both classifiers. Using 72 training spectra and 18 test spectra per material, each averaged by ten shots, only PLS-DA achieved full discrimination, and the mean centre approach made it slightly more robust. Continuing with PLS-DA, the relation between data averaging and convergence to 0.3% average error was investigated using 9-fold cross-validations. Single-shot PLS-DA presented the highest challenge and most desirable methodology, which converged with 59 PC. The degree of success in practical testing will depend on the quality of the training set and the implications of the possibly remaining false positives.

  16. An international evaluation of holmium oxide solution reference materials for wavelength calibration in molecular absorption spectrophotometry.

    Science.gov (United States)

    Travis, John C; Zwinkels, Joanne C; Mercader, Flora; Ruíz, Arquímedes; Early, Edward A; Smith, Melody V; Noël, Mario; Maley, Marissa; Kramer, Gary W; Eckerle, Kenneth L; Duewer, David L

    2002-07-15

    Commercial spectrophotometers typically use absorption-based wavelength calibration reference materials to provide wavelength accuracy for their applications. Low-mass fractions of holmium oxide (Ho2O3) in dilute acidic aqueous solution and in glass matrixes have been favored for use as wavelength calibration materials on the basis of spectral coverage and absorption band shape. Both aqueous and glass Ho2O3 reference materials are available commercially and through various National Metrology Institutes (NMIs). Three NMIs of the North American Cooperation in Metrology (NORAMET) have evaluated the performance of Ho3-(aq)-based Certified Reference Materials (CRMs) under "routine" operating conditions using commercial instrumentation. The study was not intended to intercompare national wavelength scales but to demonstrate comparability of wavelength measurements among the participants and between two versions of the CRMs. It was also designed to acquire data from a variety of spectrophotometers for use in a NIST study of wavelength assignment algorithms and to provide a basis for a possible reassessment of NIST-certified Ho3+(aq) band locations. The resulting data show a substantial level of agreement among laboratories, instruments, CRM preparations, and peak-location algorithms. At the same time, it is demonstrated that the wavelength comparability of the five participating instruments can actually be improved by calibrating all of the instruments to the consensus Ho3+(aq) band locations. This finding supports the value of absorption-based wavelength standards for calibrating absorption spectrophotometers. Coupled with the demonstrated robustness of the band position values with respect to preparation and measurement conditions, it also supports the concept of extending the present approach to additional NMIs in order to certify properly prepared dilute acidic Ho2O3 solution as an intrinsic wavelength standard.

  17. History of reference materials for food and nutrition metrology: As represented in the series of BERM Symposia

    Science.gov (United States)

    Establishment of a metrology-based measurement system requires the solid foundation of traceability of measurements to available, appropriate certified reference materials (CRM). In the early 1970s the first “biological” Reference Material (RM) of Bowens Kale, Orchard Leaves, and Bovine Liver from ...

  18. Functioning in lymphedema from the patients' perspective using the International Classification of Functioning, Disability and health (ICF) as a reference

    NARCIS (Netherlands)

    Viehoff, P.B.; Gielink, P.D.; Damstra, R.J.; Heerkens, Y.F.; Ravensberg, C.D. van; Neumann, M.H.

    2015-01-01

    Abstract Purpose. To identify and quantify meaningful concepts in lymphedema from the patients' perspectives using the International Classification of Functioning, Disability and Health (ICF). Methods. Six focus group interviews in five different centers were organized, audiotaped, transcribed verba

  19. Functioning in lymphedema from the patients' perspective using the International Classification of Functioning, Disability and health (ICF) as a reference

    NARCIS (Netherlands)

    Viehoff, P.B.; Gielink, P.D.; Damstra, R.J.; Heerkens, Y.F.; Ravensberg, C.D. van; Neumann, M.H.

    2015-01-01

    Abstract Purpose. To identify and quantify meaningful concepts in lymphedema from the patients' perspectives using the International Classification of Functioning, Disability and Health (ICF). Methods. Six focus group interviews in five different centers were organized, audiotaped, transcribed

  20. Bias in the absorption coefficient determination of a fluorescent dye, standard reference material 1932 fluorescein solution

    Energy Technology Data Exchange (ETDEWEB)

    DeRose, Paul C. [Analytical Chemistry Division, National Institute of Standards and Technology, 100 Bureau Dr., Gaithersburg, MD 20899-8394 (United States)]. E-mail: paul.derose@nist.gov; Kramer, Gary W. [Analytical Chemistry Division, National Institute of Standards and Technology, 100 Bureau Dr., Gaithersburg, MD 20899-8394 (United States)

    2005-06-15

    The absorption coefficient of standard reference material[registered] (SRM[registered]) 1932, fluorescein in a borate buffer solution (pH=9.5) has been determined at {lambda}=488.0, 490.0, 490.5 and 491.0 nm using the US national reference UV/visible spectrophotometer. The purity of the fluorescein was determined to be 97.6% as part of the certification of SRM 1932. The solution measured was prepared gravimetrically by diluting SRM 1932 with additional borate buffer. The value of the absorption coefficient was corrected for bias due to fluorescence that reaches the detector and for dye purity. Bias due to fluorescence was found to be on the order of -1% for both monochromatic and polychromatic (e.g., diode-array based) spectrophotometers.

  1. Results of a Saxitoxin Proficiency Test Including Characterization of Reference Material and Stability Studies

    Directory of Open Access Journals (Sweden)

    Kirsi Harju

    2015-11-01

    Full Text Available A saxitoxin (STX proficiency test (PT was organized as part of the Establishment of Quality Assurance for the Detection of Biological Toxins of Potential Bioterrorism Risk (EQuATox project. The aim of this PT was to provide an evaluation of existing methods and the European laboratories’ capabilities for the analysis of STX and some of its analogues in real samples. Homogenized mussel material and algal cell materials containing paralytic shellfish poisoning (PSP toxins were produced as reference sample matrices. The reference material was characterized using various analytical methods. Acidified algal extract samples at two concentration levels were prepared from a bulk culture of PSP toxins producing dinoflagellate Alexandrium ostenfeldii. The homogeneity and stability of the prepared PT samples were studied and found to be fit-for-purpose. Thereafter, eight STX PT samples were sent to ten participating laboratories from eight countries. The PT offered the participating laboratories the possibility to assess their performance regarding the qualitative and quantitative detection of PSP toxins. Various techniques such as official Association of Official Analytical Chemists (AOAC methods, immunoassays, and liquid chromatography-mass spectrometry were used for sample analyses.

  2. Short-term stability test for thorium soil candidate a reference material

    Energy Technology Data Exchange (ETDEWEB)

    Clain, Almir F.; Fonseca, Adelaide M.G.; Dantas, Vanessa V.D.B.; Braganca, Maura J.C.; Souza, Poliana S., E-mail: almir@ird.gov.br, E-mail: adelaide@ird.gov.br, E-mail: vanessa@ird.gov.br, E-mail: maura@ird.gov.br, E-mail: poliana@bolsista.ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    This work describes a methodology to determine the soil short-term stability after the steps of production in laboratory. The short-term stability of the soil is an essential property to be determined in order to producing a reference material. The soil is a candidate of reference material for chemical analysis of thorium with metrological traceability to be used in environmental analysis, equipment calibration, validation methods, and quality control. A material is considered stable in a certain temperature if the property of interest does not change with time, considering the analytical random fluctuations. Due to this, the angular coefficient from the graphic of Th concentration versus elapsed time must be near to zero. The analytical determinations of thorium concentration were performed by Instrumental Neutron activation Analysis. The slopes and their uncertainties were obtained from the regression lines at temperatures of 20 deg C and 60 deg C, with control temperature of -20 deg C. From the obtained data a t-test was applied. In both temperatures the calculated t-value was lower than the critical value, so we can conclude with 95% confidence level that no significant changes happened during the period studied concerning thorium concentration in soil at temperatures of 20 deg C and 60 deg C, showing stability at these temperatures. (author)

  3. Evaluation of a fungal collection as certified reference material producer and as a biological resource center

    Directory of Open Access Journals (Sweden)

    Tatiana Forti

    2016-06-01

    Full Text Available Abstract Considering the absence of standards for culture collections and more specifically for biological resource centers in the world, in addition to the absence of certified biological material in Brazil, this study aimed to evaluate a Fungal Collection from Fiocruz, as a producer of certified reference material and as Biological Resource Center (BRC. For this evaluation, a checklist based on the requirements of ABNT ISO GUIA34:2012 correlated with the ABNT NBR ISO/IEC17025:2005, was designed and applied. Complementing the implementation of the checklist, an internal audit was performed. An evaluation of this Collection as a BRC was also conducted following the requirements of the NIT-DICLA-061, the Brazilian internal standard from Inmetro, based on ABNT NBR ISO/IEC 17025:2005, ABNT ISO GUIA 34:2012 and OECD Best Practice Guidelines for BRCs. This was the first time that the NIT DICLA-061 was applied in a culture collection during an internal audit. The assessments enabled the proposal for the adequacy of this Collection to assure the implementation of the management system for their future accreditation by Inmetro as a certified reference material producer as well as its future accreditation as a Biological Resource Center according to the NIT-DICLA-061.

  4. Multivariate methods for analysis of environmental reference materials using laser-induced breakdown spectroscopy

    Directory of Open Access Journals (Sweden)

    Shikha Awasthi

    2017-06-01

    Full Text Available Analysis of emission from laser-induced plasma has a unique capability for quantifying the major and minor elements present in any type of samples under optimal analysis conditions. Chemometric techniques are very effective and reliable tools for quantification of multiple components in complex matrices. The feasibility of laser-induced breakdown spectroscopy (LIBS in combination with multivariate analysis was investigated for the analysis of environmental reference materials (RMs. In the present work, different (Certified/Standard Reference Materials of soil and plant origin were analyzed using LIBS and the presence of Al, Ca, Mg, Fe, K, Mn and Si were identified in the LIBS spectra of these materials. Multivariate statistical methods (Partial Least Square Regression and Partial Least Square Discriminant Analysis were employed for quantitative analysis of the constituent elements using the LIBS spectral data. Calibration models were used to predict the concentrations of the different elements of test samples and subsequently, the concentrations were compared with certified concentrations to check the authenticity of models. The non-destructive analytical method namely Instrumental Neutron Activation Analysis (INAA using high flux reactor neutrons and high resolution gamma-ray spectrometry was also used for intercomparison of results of two RMs by LIBS.

  5. Organic depth profiling of a nanostructured delta layer reference material using large argon cluster ions.

    Science.gov (United States)

    Lee, J L S; Ninomiya, S; Matsuo, J; Gilmore, I S; Seah, M P; Shard, A G

    2010-01-01

    Cluster ion beams have revolutionized the analysis of organic surfaces in time-of-flight secondary ion mass spectrometry and opened up new capabilities for organic depth profiling. Much effort has been devoted to understanding the capabilities and improving the performance of SF(5)(+) and C(60)(n+), which are successful for many, but not all, organic materials. Here, we explore the potential of organic depth profiling using novel argon cluster ions, Ar(500)(+) to Ar(1000)(+). We present results for an organic delta layer reference sample, consisting of ultrathin "delta" layers of Irganox 3114 (approximately 2.4 nm) embedded between thick layers of Irganox 1010 (approximately 46 or 91 nm). This indicates that, for the reference material, major benefits can be obtained with Ar cluster ions, including a constant high sputtering yield throughout a depth of approximately 390 nm, and an extremely low sputter-induced roughness of <5 nm. Although the depth resolution is currently limited by an instrumental artifact, and may not be the best attainable, these initial results strongly indicate the potential to achieve high depth resolution and suggest that Ar cluster ions may have a major role to play in the depth profiling of organic materials.

  6. Identifying the concepts contained in outcome measures of clinical trials on four internal disorders using the international classification of functioning, disability and health as a reference

    OpenAIRE

    2004-01-01

    Objectives: To systematically identify and compare the concepts contained in outcome measures of clinical trials on chronic ischemic heart disease, diabetes mellitus, obesity and obstructive pulmonary disease, including asthma using the International Classification of Functioning, Disability and Health (ICF) as a reference. Methods: Randomized controlled trials between 1993 and 2003 were located in MEDLINE and selected according predefined criteria. The outcome measures were extracted and...

  7. Development of a standard reference material for Cr(vi) in contaminated soil

    Science.gov (United States)

    Nagourney, S.J.; Wilson, S.A.; Buckley, B.; Kingston, H.M.S.; Yang, S.-Y.; Long, S.E.

    2008-01-01

    Over the last several decades, considerable contamination by hexavalent chromium has resulted from the land disposal of Chromite Ore Processing Residue (COPR). COPR contains a number of hexavalent chromium-bearing compounds that were produced in high temperature industrial processes. Concern over the carcinogenic potential of this chromium species, and its environmental mobility, has resulted in efforts to remediate these waste sites. To provide support to analytical measurements of hexavalent chromium, a candidate National Institute of Standards and Technology (NIST) Standard Reference Material?? (SRM 2701), having a hexavalent chromium content of approximately 500 mg kg -1, has been developed using material collected from a waste site in Hudson County, New Jersey, USA. The collection, processing, preparation and preliminary physico-chemical characterization of the material are discussed. A two-phase multi-laboratory testing study was carried out to provide data on material homogeneity and to assess the stability of the material over the duration of the study. The study was designed to incorporate several United States Environmental Protection Agency (USEPA) determinative methods for hexavalent chromium, including Method 6800 which is based on speciated isotope dilution mass spectrometry (SIDMS), an approach which can account for chromium species inter-conversion during the extraction and measurement sequence. This journal is ?? The Royal Society of Chemistry 2008.

  8. Preparation and certification of Re-Os dating reference materials: Molybdenites HLP and JDC

    Science.gov (United States)

    Du, A.; Wu, S.; Sun, D.; Wang, Shaoming; Qu, W.; Markey, R.; Stain, H.; Morgan, J.; Malinovskiy, D.

    2004-01-01

    Two Re-Os dating reference material molybdenites were prepared. Molybdenite JDC and molybdenite HLP are from a carbonate vein-type molybdenum-(lead)- uranium deposit in the Jinduicheng-Huanglongpu area of Shaanxi province, China. The samples proved to be homogeneous, based on the coefficient of variation of analytical results and an analysis of variance test. The sampling weight was 0.1 g for JDC and 0.025 g for HLP. An isotope dilution method was used for the determination of Re and Os. Sample decomposition and preconcentration of Re and Os prior to measurement were accomplished using a variety of methods: acid digestion, alkali fusion, ion exchange and solvent extraction. Negative thermal ionisation mass spectrometry and inductively coupled plasma-mass spectrometry were used for the determination of Re and 187Os concentration and isotope ratios. The certified values include the contents of Re and Os and the model ages. For HLP, the Re content was 283.8 ?? 6.2 ??g g-1, 187Os was 659 ?? 14 ng g-1 and the Re-Os model age was 221.4 ?? 5.6 Ma. For JDC, the Re content was 17.39 ?? 0.32 ng g-1, 187Os was 25.46 ?? 0.60 ng g-1 and the Re-Os model age was 139.6 ?? 3.8 Ma. Uncertainties for both certified reference materials are stated at the 95% level of confidence. Three laboratories (from three countries: P.R. China, USA, Sweden) joined in the certification programme. These certified reference materials are primarily useful for Re-Os dating of molybdenite, sulfides, black shale, etc.

  9. The determination of water in crude oil and transformer oil reference materials.

    Science.gov (United States)

    Margolis, Sam A; Hagwood, Charles

    2003-05-01

    The measurement of the amount of water in oils is of significant economic importance to the industrial community, particularly to the electric power and crude oil industries. The amount of water in transformer oils is critical to their normal function and the amount of water in crude oils affects the cost of the crude oil at the well head, the pipeline, and the refinery. Water in oil Certified Reference Materials (CRM) are essential for the accurate calibration of instruments that are used by these industries. Three NIST Standard Reference Materials (SRMs) have been prepared for this purpose. The water in these oils has been measured by both coulometric and volumetric Karl Fischer methods. The compounds (such as sulfur compounds) that interfere with the Karl Fischer reaction (interfering substances) and inflate the values for water by also reacting with iodine have been measured coulometrically. The measured water content of Reference Material (RM) 8506a Transformer Oil is 12.1+/-1.9 mg kg(-1) (plus an additional 6.2+/-0.9 mg kg(-1) of interfering substances). The measured water content of SRM 2722 Sweet Crude Oil, is 99+/-6 mg kg(-1) (plus an additional 5+/-2 mg kg(-1) of interfering substances). The measured water content of SRM 2721 Sour Crude Oil, is 134+/-18 mg kg(-1) plus an additional 807+/-43 mg kg(-1) of interfering substances. Interlaboratory studies conducted with these oil samples (using SRM 2890, water saturated 1-octanol, as a calibrant) are reported. Some of the possible sources of bias in these measurements were identified, These include: improperly calibrated instruments, inability to measure the calibrant accurately, Karl Fischer reagent selection, and volatilization of the interfering substances in SRM 2721.

  10. DISCUSSION ON PERIOD VERIFICATION OF MARINE CERTIFIED REFERENCE MATERIAL IN LABORATORY%浅谈实验室如何进行海洋标准物质期间核查

    Institute of Scientific and Technical Information of China (English)

    吴碧玉; 谷尚莉

    2011-01-01

    The classification of marine certified reference material was introuduced. The method for period verification of marine certified reference material to ensure the accuracy of value in marine environmental monitoring and improve the quality of marine monitoring was expounded.%介绍海洋标准物质的分类,阐述了各种海洋标准物质的期间核查方法,以保证海洋环境监测工作量值的准确性,提高海洋监测的质量.

  11. Development of a new chlorogenic acid certified reference material for food and drug analysis.

    Science.gov (United States)

    Yang, Dezhi; Jiao, LingTai; Zhang, Baoxi; Du, Guanhua; Lu, Yang

    2017-06-05

    This paper reports the preparation and characterization of a new chlorogenic acid (CHA) certified reference material (CRM), which is unavailable commercially. CHA is an active ingredient found in many geo-authentic Chinese medicinal materials and developed as an anti-cancer drug. In this work, trace impurities were isolated and identified through various techniques. CHA CRM was quantified with two analytical methods, and their results were in good agreement with each other. The certified value and corresponding expanded uncertainty of CHA CRM reached 99.4%±0.2%, which was calculated by multiplying the combined standard uncertainty by the coverage factor (k=2), at a confidence level of 95%. This CRM can be used to calibrate measurement system, evaluate or validate measurement procedures, assign traceable property values to non-CRMs, and conduct quality control assays. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Toward New High Temperature Reference Materials for Calorimetry and Thermal Analysis

    Directory of Open Access Journals (Sweden)

    Razouk R.

    2014-01-01

    Full Text Available The French National Metrology Laboratory LNE-LCM has developed a high temperature reference facility for accurate measurements of the specific heat capacity and of the enthalpy of fusion of materials over the temperature range [23 °C, 1000 °C]. The metrological approach was to modify a commercial Calvet calorimeter in order to lower the uncertainty of measurement and to insure the metrological traceability of the measurements to the SI units, in particular by designing a new calibration system. The enthalpies of fusion of pure metals (indium, tin and silver and of a binary alloy Ag-28Cu have been measured. The results obtained on the three pure metallic materials are in very good agreement with data obtained by other National Metrology Institutes (NMIs using adiabatic calorimetry.

  13. Electrochromic materials and devices for energy-efficient windows. [161 references

    Energy Technology Data Exchange (ETDEWEB)

    Lampert, C.M.

    1984-02-01

    Numerous inorganic and organic electrochromic materials are discussed in the context of developing a film-based optical shutter for a window application. It is possible electronically to alter a window's transmission and reflection properties by use of electrochromic thin films. This allows regulation of conductive and radiative heat transfer rates, with variable optical attenuation. As a result, an aperture can be optically and thermally managed, reducing space heating and cooling loads. The properties of transition metal oxides, such as WO/sub 3/, MoO/sub 3/, Ir/sub 2/O/sub 3/ and V/sub 2/O/sub 5/, are detailed. Organic systems, such as heptyl viologen and polytungsten anion, are reviewed. Also, intercalated structures are discussed. Various designs of working devices are outlined with emphasis on solid-state configurations. From this quantification, materials and devices with appropriate deposition techniques for window applications are detailed. 161 references, 9 figures, 4 tables.

  14. Fundamental studies to develop certified reference material to calibrate spectrophotometer in the ultraviolet region

    Science.gov (United States)

    da Conceição, F. C.; Borges, P. P.; Gomes, J. F. S.

    2016-07-01

    Spectrophotometry is the technique used in a great number of laboratories around the world. Quantitative determination of a high number of inorganic, organic and biological species can be made by spectrophotometry using calibrated spectrophotometers. International standards require the use of optical filters to perform the calibration of spectrophotometers. One of the recommended materials is the crystalline potassium dichromate (K2Cr2O7), which is used to prepare solutions in specific concentrations for calibration or verification of spectrophotometers in the ultraviolet (UV) spectral regions. This paper presents the results concerning the fundamental studies for developing a certified reference material (CRM) of crystalline potassium dichromate to be used as standard of spectrophotometers in order to contribute to reliable quantitative analyses.

  15. Protein standardization V: value transfer. A practical protocol for the assignment of serum protein values from a Reference Material to a Target Material.

    Science.gov (United States)

    Blirup-Jensen, Søren; Johnson, A Myron; Larsen, Marianne

    2008-01-01

    We present a practical protocol for the assignment of values to serum proteins in a Target Material using a Reference Material. This protocol is based on the model of Direct Value Transfer between serum matrices and is intended to improve the value assignment of commercial calibrators using the Reference Material CRM 470 (now labeled ERM-DA 470) or similar reference materials. The procedure describes the general as well as the practical principles involved in the value assignment (with examples). The practical transfer protocol is based on multiple assays of 6 dilutions of the Reference Material and 6 dilutions of the Target Material. The transfer protocol requires several measurements a day repeated on several days, an important prerequisite being that all reconstitutions and dilutions are controlled by weighing thus reducing uncertainty in the transfer. In open systems that allow the use of the Reference Material as calibrator and the Target Material as samples, the proportionality of the two materials (the presence or absence of matrix effects) can now be directly assessed by evaluating a single regression plot. If no matrix effects are found, the regression line will pass through zero with a slope equal to the ratio of the concentrations of the two materials. In closed systems, the dedicated commercial calibrator has to be used as such; the Reference Material and the Target Material are now assayed as samples against this calibrator. Two regression plots are therefore obtained; if no matrix effects are present among the two materials and the calibrator, both the Reference and Target Materials will show zero intercepts, and the ratio of the two slopes will equal the ratio of the concentrations.

  16. Assessment of commutability for candidate certified reference material ERM-BB130 "chloramphenicol in pork".

    Science.gov (United States)

    Zeleny, Reinhard; Emteborg, Håkan; Schimmel, Heinz

    2010-10-01

    Chloramphenicol (CAP), an effective antibiotic against many microorganisms, is meanwhile banned in the EU for treatment of food-producing animals due to adverse health effects. The Institute for Reference Materials and Measurements (IRMM) is currently developing a certified reference material (CRM) for CAP in pork, intended for validation and method performance verifications of analytical methods. The material will be certified using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) methods and has a target CAP level around the minimum required performance limit (MRPL) of 0.3 microg/kg. To prove that the material can be applied as a quality control tool for screening methods, a commutability study was conducted, involving five commercially available enzyme-linked immunosorbent assay kits and one biosensor assay (BiaCore kit). Meat homogenates (cryo-milled wet tissue) with CAP concentrations around the MRPL and the candidate CRM (lyophilised powder) were measured by LC-MS/MS and GC-MS as well as the six screening methods. Pairwise method comparisons of results obtained for the two sample types showed that the CRM can successfully be applied as quality control (QC) sample to all six screening methods. The study suggests that ERM-BB130 is sufficiently commutable with the investigated assays and that laboratories applying one of the investigated kits therefore benefit from using ERM-BB130 to demonstrate the correctness of their results. However, differences among the assays were observed, either in the abundance of bias between screening and confirmatory LC and GC methods, the repeatability of test results, or goodness of fit between the methods.

  17. Development and application of a general plasmid reference material for GMO screening.

    Science.gov (United States)

    Wu, Yuhua; Li, Jun; Wang, Yulei; Li, Xiaofei; Li, Yunjing; Zhu, Li; Li, Jun; Wu, Gang

    The use of analytical controls is essential when performing GMO detection through screening tests. Additionally, the presence of taxon-specific sequences is analyzed mostly for quality control during GMO detection. In this study, 11 commonly used genetic elements involving three promoters (P-35S, P-FMV35S and P-NOS), four marker genes (Bar, NPTII, HPT and Pmi), and four terminators (T-NOS, T-35S, T-g7 and T-e9), together with the reference gene fragments from six major crops of maize, soybean, rapeseed, rice, cotton and wheat, were co-integrated into the same single plasmid to construct a general reference plasmid pBI121-Screening. The suitability test of pBI121-Screening plasmid as reference material indicated that the non-target sequence on the pBI121-Screening plasmid did not affect the PCR amplification efficiencies of screening methods and taxon-specific methods. The sensitivity of screening and taxon-specific assays ranged from 5 to 10 copies of pBI121-Screening plasmid, meeting the sensitivity requirement of GMO detection. The construction of pBI121-Screening solves the lack of a general positive control for screening tests, thereby reducing the workload and cost of preparing a plurality of the positive control. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Periodic reference tracking control approach for smart material actuators with complex hysteretic characteristics

    Science.gov (United States)

    Sun, Zhiyong; Hao, Lina; Song, Bo; Yang, Ruiguo; Cao, Ruimin; Cheng, Yu

    2016-10-01

    Micro/nano positioning technologies have been attractive for decades for their various applications in both industrial and scientific fields. The actuators employed in these technologies are typically smart material actuators, which possess inherent hysteresis that may cause systems behave unexpectedly. Periodic reference tracking capability is fundamental for apparatuses such as scanning probe microscope, which employs smart material actuators to generate periodic scanning motion. However, traditional controller such as PID method cannot guarantee accurate fast periodic scanning motion. To tackle this problem and to conduct practical implementation in digital devices, this paper proposes a novel control method named discrete extended unparallel Prandtl-Ishlinskii model based internal model (d-EUPI-IM) control approach. To tackle modeling uncertainties, the robust d-EUPI-IM control approach is investigated, and the associated sufficient stabilizing conditions are derived. The advantages of the proposed controller are: it is designed and represented in discrete form, thus practical for digital devices implementation; the extended unparallel Prandtl-Ishlinskii model can precisely represent forward/inverse complex hysteretic characteristics, thus can reduce modeling uncertainties and benefits controllers design; in addition, the internal model principle based control module can be utilized as a natural oscillator for tackling periodic references tracking problem. The proposed controller was verified through comparative experiments on a piezoelectric actuator platform, and convincing results have been achieved.

  19. Soot Reference Materials for instrument calibration and intercomparisons: a workshop summary with recommendations

    Directory of Open Access Journals (Sweden)

    D. Baumgardner

    2012-03-01

    Full Text Available Soot, which is produced from biomass burning and the incomplete combustion of fossil and biomass fuels, has been linked to regional and global climate change and to negative health problems. Scientists measure soot using a variety of methods in order to quantify source emissions and understand its atmospheric chemistry, reactivity under emission conditions, interaction with solar radiation, influence on clouds, and health impacts. A major obstacle currently limiting progress is the absence of established standards or reference materials for calibrating the many instruments used to measure the various properties of soot.

    The current state of availability and practicability of soot standard reference materials (SRMs was reviewed by a group of 50 international experts during a workshop in June of 2011. The workshop was convened to summarize the current knowledge on soot measurement techniques, identify the measurement uncertainties and limitations related to the lack of SRMs, and identify attributes of SRMs that, if developed, would reduce measurement uncertainties. The workshop established that suitable SRMs are available for calibrating some, but not all, measurement methods. The community of single-particle sootphotometer (SP2 users identified a suitable SRM, fullerene soot, but users of instruments that measure light absorption by soot collected on filters did not. Similarly, those who use thermal optical analysis (TOA to analyze the organic and elemental carbon components of soot were not satisfied with current SRMs. The workshop produced recommendations for the development of new SRMs that would be suitable for the different soot measurement methods.

  20. Palm-based standard reference materials for iodine value and slip melting point.

    Science.gov (United States)

    Tarmizi, Azmil Haizam Ahmad; Lin, Siew Wai; Kuntom, Ainie

    2008-09-22

    This work described study protocols on the production of Palm-Based Standard Reference Materials for iodine value and slip melting point. Thirty-three laboratories collaborated in the inter-laboratory proficiency tests for characterization of iodine value, while thirty-two laboratories for characterization of slip melting point. The iodine value and slip melting point of palm oil, palm olein and palm stearin were determined in accordance to MPOB Test Methods p3.2:2004 and p4.2:2004, respectively. The consensus values and their uncertainties were based on the acceptability of statistical agreement of results obtained from collaborating laboratories. The consensus values and uncertainties for iodine values were 52.63 +/- 0.14 Wijs in palm oil, 56.77 +/- 0.12 Wijs in palm olein and 33.76 +/- 0.18 Wijs in palm stearin. For the slip melting points, the consensus values and uncertainties were 35.6 +/- 0.3 degrees C in palm oil, 22.7 +/- 0.4 degrees C in palm olein and 53.4 +/- 0.2 degrees C in palm stearin. Repeatability and reproducibility relative standard deviations were found to be good and acceptable, with values much lower than that of 10%. Stability of Palm-Based Standard Reference Materials remained stable at temperatures of -20 degrees C, 0 degrees C, 6 degrees C and 24 degrees C upon storage for one year.

  1. Extensive sequencing of seven human genomes to characterize benchmark reference materials.

    Science.gov (United States)

    Zook, Justin M; Catoe, David; McDaniel, Jennifer; Vang, Lindsay; Spies, Noah; Sidow, Arend; Weng, Ziming; Liu, Yuling; Mason, Christopher E; Alexander, Noah; Henaff, Elizabeth; McIntyre, Alexa B R; Chandramohan, Dhruva; Chen, Feng; Jaeger, Erich; Moshrefi, Ali; Pham, Khoa; Stedman, William; Liang, Tiffany; Saghbini, Michael; Dzakula, Zeljko; Hastie, Alex; Cao, Han; Deikus, Gintaras; Schadt, Eric; Sebra, Robert; Bashir, Ali; Truty, Rebecca M; Chang, Christopher C; Gulbahce, Natali; Zhao, Keyan; Ghosh, Srinka; Hyland, Fiona; Fu, Yutao; Chaisson, Mark; Xiao, Chunlin; Trow, Jonathan; Sherry, Stephen T; Zaranek, Alexander W; Ball, Madeleine; Bobe, Jason; Estep, Preston; Church, George M; Marks, Patrick; Kyriazopoulou-Panagiotopoulou, Sofia; Zheng, Grace X Y; Schnall-Levin, Michael; Ordonez, Heather S; Mudivarti, Patrice A; Giorda, Kristina; Sheng, Ying; Rypdal, Karoline Bjarnesdatter; Salit, Marc

    2016-06-07

    The Genome in a Bottle Consortium, hosted by the National Institute of Standards and Technology (NIST) is creating reference materials and data for human genome sequencing, as well as methods for genome comparison and benchmarking. Here, we describe a large, diverse set of sequencing data for seven human genomes; five are current or candidate NIST Reference Materials. The pilot genome, NA12878, has been released as NIST RM 8398. We also describe data from two Personal Genome Project trios, one of Ashkenazim Jewish ancestry and one of Chinese ancestry. The data come from 12 technologies: BioNano Genomics, Complete Genomics paired-end and LFR, Ion Proton exome, Oxford Nanopore, Pacific Biosciences, SOLiD, 10X Genomics GemCode WGS, and Illumina exome and WGS paired-end, mate-pair, and synthetic long reads. Cell lines, DNA, and data from these individuals are publicly available. Therefore, we expect these data to be useful for revealing novel information about the human genome and improving sequencing technologies, SNP, indel, and structural variant calling, and de novo assembly.

  2. Accuracy of ELISA detection methods for gluten and reference materials: a realistic assessment.

    Science.gov (United States)

    Diaz-Amigo, Carmen; Popping, Bert

    2013-06-19

    The determination of prolamins by ELISA and subsequent conversion of the resulting concentration to gluten content in food appears to be a comparatively simple and straightforward process with which many laboratories have years-long experience. At the end of the process, a value of gluten, expressed in mg/kg or ppm, is obtained. This value often is the basis for the decision if a product can be labeled gluten-free or not. On the basis of currently available scientific information, the accuracy of the obtained values with commonly used commercial ELISA kits has to be questioned. Although recently several multilaboratory studies have been conducted in an attempt to emphasize and ensure the accuracy of the results, data suggest that it was the precision of these assays, not the accuracy, that was confirmed because some of the underlying assumptions for calculating the gluten content lack scientific data support as well as appropriate reference materials for comparison. This paper discusses the issues of gluten determination and quantification with respect to antibody specificity, extraction procedures, reference materials, and their commutability.

  3. Preparation and certification of arsenate [As(V)] reference material, NMIJ CRM 7912-a.

    Science.gov (United States)

    Narukawa, Tomohiro; Kuroiwa, Takayoshi; Narushima, Izumi; Jimbo, Yasujiro; Suzuki, Toshihiro; Chiba, Koichi

    2010-05-01

    Arsenate [As(V)] solution reference material, National Metrology Institute of Japan (NMIJ) certified reference material (CRM) 7912-a, for speciation of arsenic species was developed and certified by NMIJ, the National Institute of Advanced Industrial Science and Technology. High-purity As(2)O(3) reagent powder was dissolved in 0.8 M HNO(3) solution and As(III) was oxidized to As(V) with HNO(3) to prepare 100 mg kg(-1) of As(V) candidate CRM solution. The solution was bottled in 400 bottles (50 mL each). The concentration of As(V) was determined by four independent analytical techniques-inductively coupled plasma mass spectrometry, inductively coupled plasma optical emission spectrometry, graphite furnace atomic absorption spectrometry, and liquid chromatography inductively coupled plasma mass spectrometry-according to As(V) calibration solutions, which were prepared from the arsenic standard of the Japan Calibration Service system and whose species was guaranteed to be As(V) by NMIJ. The uncertainties of all the measurements and preparation procedures were evaluated. The certified value of As(V) in the CRM is (99.53 +/- 1.67) mg kg(-1) (k = 2).

  4. Determination of plutonium isotopes in seawater reference materials using isotope-dilution ICP-MS.

    Science.gov (United States)

    Zheng, Jian; Yamada, Masatoshi

    2012-09-01

    We analyzed the activities of (239)Pu, (240)Pu, (239+240)Pu, (241)Pu, the ratio of number of atoms (atom ratio) for (240)Pu/(239)Pu, and the activity ratio of (241)Pu/(239+240)Pu in seawater reference materials, IAEA-443 and IAEA-381, using a highly sensitive isotope dilution sector field inductively coupled plasma mass spectrometry method. With a mean chemical yield of 65% determined with (242)Pu as a tracer, we found that the experimentally established values in IAEA-443 for (239)Pu, (240)Pu, (241)Pu and (239+240)Pu activities are almost the same as those in IAEA-381. Regarding the (239+240)Pu activity, we provided the most precise and accurate result among the twelve laboratories, which participated in the interlaboratory comparison. In addition, for the (240)Pu/(239)Pu atom ratio, our results for IAEA-381 (0.2315±0.0008) and IAEA-443 (0.2325±0.0008) are in good agreement with the IAEA information value (0.229±0.006), but have much smaller uncertainty. Since the new seawater reference material, IAEA-443, is commercially available, it can be used not only for method validation for seawater plutonium isotope ratio and activity analysis, but also for more general use as a plutonium isotope standard for mass discrimination correction for other environmental samples.

  5. Platinum stable isotope analysis of geological standard reference materials by double-spike MC-ICPMS

    Science.gov (United States)

    Creech, J.B.; Baker, J.A.; Handler, M.R.; Bizzarro, M.

    2015-01-01

    We report a method for the chemical purification of Pt from geological materials by ion-exchange chromatography for subsequent Pt stable isotope analysis by multiple-collector inductively coupled plasma mass spectrometry (MC-ICPMS) using a 196Pt-198Pt double-spike to correct for instrumental mass bias. Double-spiking of samples was carried out prior to digestion and chemical separation to correct for any mass-dependent fractionation that may occur due to incomplete recovery of Pt. Samples were digested using a NiS fire assay method, which pre-concentrates Pt into a metallic bead that is readily dissolved in acid in preparation for anion-exchange chemistry. Pt was recovered from anion-exchange resin in concentrated HNO3 acid after elution of matrix elements, including the other platinum group elements (PGE), in dilute HCl and HNO3 acids. The separation method has been calibrated using a precious metal standard solution doped with a range of synthetic matrices and results in Pt yields of ≥90% with purity of ≥95%. Using this chemical separation technique, we have separated Pt from 11 international geological standard reference materials comprising of PGE ores, mantle rocks, igneous rocks and one sample from the Cretaceous–Paleogene boundary layer. Pt concentrations in these samples range from ca. 5 ng g−1 to 4 μg g−1. This analytical method has been shown to have an external reproducibility on δ198Pt (permil difference in the 198Pt/194Pt ratio from the IRMM-010 standard) of ±0.040 (2 sd) on Pt solution standards (Creech et al., 2013, J. Anal. At. Spectrom. 28, 853-865). The reproducibility in natural samples is evaluated by processing multiple replicates of four standard reference materials, and is conservatively taken to be ca. ±0.088 (2 sd). Pt stable isotope data for the full set of reference materials have a range of δ198Pt values with offsets of up to 0.4‰ from the IRMM-010 standard, which are readily resolved with this technique. These results

  6. Functioning in lymphedema from the patients’ perspective using the International Classification of Functioning, Disability and health (ICF) as a reference

    NARCIS (Netherlands)

    Viehoff, Peter; Gielink, Petra; Damstra, Robert; Heerkens, Yvonne; Ravensberg, Dorine van; Neumann, Martino

    2014-01-01

    To capture the views of different health care providers involved in the treatment of patients with lymphoedema from various countries around the world on the functioning of lymphoedema patients and the factors influencing functioning of these patients using the international classification of functi

  7. Characterizing Vaccinium berry Standard Reference Materials by GC-MS using NIST spectral libraries.

    Science.gov (United States)

    Lowenthal, Mark S; Andriamaharavo, Nirina R; Stein, Stephen E; Phinney, Karen W

    2013-05-01

    A gas chromatography-mass spectrometry (GC-MS)-based method was developed for qualitative characterization of metabolites found in Vaccinium fruit (berry) dietary supplement Standard Reference Materials (SRMs). Definitive identifications are provided for 98 unique metabolites determined among six Vaccinium-related SRMs. Metabolites were enriched using an organic liquid/liquid extraction, and derivatized prior to GC-MS analysis. Electron ionization (EI) fragmentation spectra were searched against EI spectra of authentic standards compiled in the National Institute of Standards and Technology's mass spectral libraries, as well as spectra selected from the literature. Metabolite identifications were further validated using a retention index match along with prior probabilities and were compared with results obtained in a previous effort using collision-induced dissociation (CID) MS/MS datasets from liquid chromatography coupled to mass spectrometry experiments. This manuscript describes a nontargeted metabolite profile of Vaccinium materials, compares results among related materials and from orthogonal experimental platforms, and discusses the feasibility and development of using mass spectral library matching for nontargeted metabolite identification.

  8. Development of reference material for proficiency tests: arsenic in fish tissue

    Energy Technology Data Exchange (ETDEWEB)

    Santana, Luciana Vieira de; Sarkis, Jorge E.S.; Ulrich, Joao C.; Hortellani, Marcos Antonio, E-mail: santana-luciana@ig.com.br, E-mail: jesarkis@ipen.br, E-mail: jculrich@ipen.br, E-mail: mahortel@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Proficiency tests (PT) are extensively used to evaluate the analytical competence of laboratories, and are also used as a part of accreditation processes. For this reason are important tool for quality control of laboratories including laboratories that act directly with food exporting companies. In Brazil there are no providers of proficiency testing for toxic metals, such as arsenic in fish tissue. This study presents a protocol to produce reference material to be used in proficiency test for arsenic in fish tissue following the recommendations of the ISO Guide 35. The preparation scheme consisted of: selecting of individuals, cleaning of scale and skin, trituration, homogenization, and spiking with arsenic at two levels of concentration. The mixture was then irradiated in a cyclotron Cyclone 30 Applications ion beam with cobalt 60 at 10.00 ± 1.05 KGy, before being packed into sachets. To verify the efficacy of the irradiation procedure, 26 (randomly selected) irradiated sachets and 26 non-irradiated sachets were assessed for homogeneity and stability. The results indicate that irradiation with cobalt 60 is crucial for ensuring the preservation of the integrity of the material, providing stable material at room temperature for 2 months. The samples can therefore be transported at room temperature. (author)

  9. 硅铝铁标准物质的研制%Development of reference materials of silicon-aluminium-iron

    Institute of Scientific and Technical Information of China (English)

    李凤超; 周振华; 周晨旭

    2011-01-01

    On the basis of the needs of reference materials of silicon-aluminum-iron in our country, two reference materials of silicon-aluminum-iron were prepared According to the requirements of technical standard of silicon-aluminum-iron alloy, the silicon-aluminum-iron alloy with different content and without air hole or impurities on surface was selected as raw materials. After removing outer skin and inclusions and serting, the samples were prepared in to block samples with diameter of 40-50 mm. Then, they were grinded to particles with size smaller than 2 mm by jaw crusher. After fully mixing, the samples were repeatedly grinded with sample preparation machine. All the samples were made to pass through 0.125 mm (120 grid) screen. The u-niformity and stability tests of prepared reference materials were performed. The results showed that the prepared reference material had good uniformity and stability. The characterisation analysis of three elements including silicon, aluminum and iron in reference material was performed by several laboratories. The analytical data were tested by Grubbs method, Cochran's theorem and Shapiro-wilks method. The results showed that the normality test values of prepared reference material were all higher than the value of 95 % confidence probability. The certified values exhibited normal distribution or approximately normal distribution.

  10. GOST 8.315 "GSI. Reference materials of composition and properties of substances and materials. Basic concepts": basic principles of revision

    Directory of Open Access Journals (Sweden)

    E. V. Osintseva

    2016-01-01

    Full Text Available A key point of the revision of GOST 8.315"GSI. Reference materials of composition and properties of substances and materials. Basic concepts" is harmonization with the documents of International Organization for Standardization (ISO and International Organization of Legal Metrology"(OIML in terms of reference materials. The article sets out the basic principles of the document revision: harmonization of terms and definitions with ISO Guide 30:2015, distinction between "reference material" and "certified reference material" not only as concepts, but also as objects, which are subject to their own requirements and criteria of development, production and use (according to ISO Guide 31, ISO Guide 35, ISO 17034; introduction ofprovisions, related to the issue of reference materials, accredited to ISO 17034 by RM producers; introduction of provisions in the area of legal metrology in terms of reference materials according to OIML D 18. Introduction of the updated document will contribute to a new round of RM activity in Russia and other member-countries of Interstate council, based on international principles of RM development and use.

  11. Preparation and certification of arsenobetaine reference material NMIJ CRM 7901-a.

    Science.gov (United States)

    Narukawa, Tomohiro; Chiba, Koichi; Kuroiwa, Takayoshi; Yarita, Takashi; Takatsu, Akiko

    2007-09-01

    An arsenobetaine [(CH(3))(3)As(+)CH(2)COO(-)] solution reference material, NMIJ CRM 7901-a, intended for use in the speciation of arsenic compounds, was developed and certified by the National Metrology Institute of Japan (NMIJ), part of the National Institute of Advanced Industrial Science and Technology (AIST). The high-purity arsenobetaine powder was synthesized from trimethylarsine [(CH(3))(3)As], and it was dissolved in water in order to prepare 20 mg kg(-1) of arsenobetaine standard solution. The solution was bottled in 500 bottles (each containing 10 ml). Certification of the CRM for arsenobetaine was conducted by NMIJ. The concentration of As was determined by four independent analytical techniques (ICP-MS, ICP-OES, GFAAS and LC-ICP-MS), and each result was converted to the arsenobetaine concentration by applying an appropriate factor. The arsenobetaine concentration in the CRM was thus certified.

  12. Certification of B-group vitamins (b1, b2, b6, and b12) in four food reference materials

    NARCIS (Netherlands)

    Ollilainen, V.; Finglas, P.M.; Berg, H. van den; Froidmont-Görtz, I. de

    2001-01-01

    In 1989, the Community Bureau of Reference started a research program to improve the quality of vitamin analysis in food. To achieve this task, vitamin methodology was evaluated and tested by interlaboratory studies and the preparation of certified reference materials, which will be used for quality

  13. Certification of B-group vitamins (b1, b2, b6, and b12) in four food reference materials

    NARCIS (Netherlands)

    Ollilainen, V.; Finglas, P.M.; Berg, H. van den; Froidmont-Görtz, I. de

    2001-01-01

    In 1989, the Community Bureau of Reference started a research program to improve the quality of vitamin analysis in food. To achieve this task, vitamin methodology was evaluated and tested by interlaboratory studies and the preparation of certified reference materials, which will be used for quality

  14. Certification for copper concentration in reference material for fuel anhydro ethylic alcohol; Certificacao da concentracao de cobre em material de referencia para alcool etilico anidro combustivel (AEC)

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Lindomar Augusto dos; Rocha, Marcia Silva da; Mesko, Marcia Foster; Silva, Fagner Francisco da; Quaresma, Maria Cristina Baptista; Araujo, Thiago Oliveira [Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial (DIMCI/INMETRO), Duque de Caxias, RJ (Brazil). Diretoria de Metrologia Cientifica e Industrial], E-mail: lareis@inmetro.gov.br

    2009-07-01

    This work aiming to obtain the first certified reference material for fuel anhydro ethylic alcohol relative to the copper concentration, which has his maximum limit determined by the in force legislation providing traceability and reliability for the measurement results.

  15. Soot reference materials for instrument calibration and intercomparisons: a workshop summary with recommendations

    Directory of Open Access Journals (Sweden)

    D. Baumgardner

    2012-08-01

    Full Text Available Soot, which is produced from biomass burning and the incomplete combustion of fossil and biomass fuels, has been linked to regional and global climate change and to negative health problems. Scientists measure the properties of soot using a variety of methods in order to quantify source emissions and understand its atmospheric chemistry, reactivity under emission conditions, interaction with solar radiation, influence on clouds, and health impacts. A major obstacle currently limiting progress is the absence of established standards or reference materials for calibrating the many instruments used to measure the various properties of soot.

    The current state of availability and practicability of soot standard reference materials (SRMs was reviewed by a group of 50 international experts during a workshop in June of 2011. The workshop was convened to summarize the current knowledge on soot measurement techniques, identify the measurement uncertainties and limitations related to the lack of soot SRMs, and identify attributes of SRMs that, if developed, would reduce measurement uncertainties. The workshop established that suitable SRMs are available for calibrating some, but not all, measurement methods. The community of users of the single-particle soot-photometer (SP2, an instrument using laser-induced incandescence, identified a suitable SRM, fullerene soot, but users of instruments that measure light absorption by soot collected on filters did not. Similarly, those who use thermal optical analysis (TOA to analyze the organic and elemental carbon components of soot were not satisfied with current SRMs. The workshop, and subsequent, interactive discussions, produced a number of recommendations for the development of new SRMs, and their implementation, that would be suitable for the different soot measurement methods.

  16. Palm-Based Standard Reference Materials for Iodine Value and Slip Melting Point

    Directory of Open Access Journals (Sweden)

    Azmil Haizam Ahmad Tarmizi

    2008-01-01

    Full Text Available This work described study protocols on the production of Palm-Based Standard Reference Materials for iodine value and slip melting point. Thirty-three laboratories collaborated in the inter-laboratory proficiency tests for characterization of iodine value, while thirty-two laboratories for characterization of slip melting point. The iodine value and slip melting point of palm oil, palm olein and palm stearin were determined in accordance to MPOB Test Methods p3.2:2004 and p4.2:2004, respectively. The consensus values and their uncertainties were based on the acceptability of statistical agreement of results obtained from collaborating laboratories. The consensus values and uncertainties for iodine values were 52.63 ± 0.14 Wijs in palm oil, 56.77 ± 0.12 Wijs in palm olein and 33.76 ± 0.18 Wijs in palm stearin. For the slip melting points, the consensus values and uncertainties were 35.6 ± 0.3 °C in palm oil, 22.7 ± 0.4 °C in palm olein and 53.4 ± 0.2 °C in palm stearin. Repeatability and reproducibility relative standard deviations were found to be good and acceptable, with values much lower than that of 10%. Stability of Palm-Based Standard Reference Materials remained stable at temperatures of –20 °C, 0 °C, 6 °C and 24 °C upon storage for one year.

  17. Medical Devices; Immunology and Microbiology Devices; Classification of the Assayed Quality Control Material for Clinical Microbiology Assays. Final order.

    Science.gov (United States)

    2017-07-27

    The Food and Drug Administration (FDA, Agency, or we) is classifying the assayed quality control material for clinical microbiology assays into class II (special controls). The special controls that will apply to the device are identified in this order and will be part of the codified language for the assayed quality control material for clinical microbiology assays' classification. The Agency is classifying the device into class II (special controls) to provide a reasonable assurance of safety and effectiveness of the device.

  18. Classification of carbon materials for developing structure-properties relationships based on the aggregate state of the precursors

    Institute of Scientific and Technical Information of China (English)

    Oleksiy V. Khavryuchenko; Volodymyr D.Khavryuchenko

    2014-01-01

    Modern carbon science lacks an efficient structure-related classi-fication of materials. We present an approach based on dividing carbon materials by the aggregate state of the precursor. The common features in the structure of carbon particles that allow putting them into a group are discussed, with particular attention to the potential energy stored in the carbon structure from differ-ent rates of relaxation during the synthesis and prearrangement of structural motifs due to the effect of the precursor structure.

  19. Quantitative micro x-ray fluorescence analyses without reference standard material; Referenzprobenfreie quantitative Mikro-Roentgenfluoreszenzanalyse

    Energy Technology Data Exchange (ETDEWEB)

    Wolff, Timo

    2009-07-15

    X-ray fluorescence analysis (XRF) is a standard method for non-destructive investigations. Due to the development of polycapillary optics and SDDdetectors requiring no cooling with liquid nitrogen, XRF becomes a suitable method for a large number of applications, e. g. for the analysis of objects in arts and archaeology. Spectrometers developed for those purposes allow investigations outside of laboratories und provide excitation areas with diameters of 10-70 {mu}m. In most applications, quantification of XRF data is realized by the usage of standard reference materials. Due to absorption processes in the samples the accuracy of the results depends strongly on the similarity of the sample and the reference standard. In cases where no suitable references are available, quantification can be done based on the ''fundamental parameter (fp) method''. This quantification procedure is based on a set of equations describing the fluorescence production and detection mathematical. The cross sections for the interaction of x-rays with matter can be taken from different databases. During an iteration process the element concentrations can be determined. Quantitative XRF based on fundamental parameters requires an accurate knowledge of the excitation spectrum. In case of a conventional setup this spectrum is given by the X-ray tube spectrum and can be calculated. The use of polycapillary optics in micro-XRF spectrometers changes the spectral distribution of the excitation radiation. For this reason it is necessary to access the transmission function of the used optic. The aim of this work is to find a procedure to describe this function for routine quantification based on fundamental parameters. Most of the measurements have been carried out using a commercial spectrometer developed for applications in arts and archaeology. On the one hand the parameters of the lens, used in the spectrometer, have been investigated by different experimental characterization

  20. Comparison of Capability of Digitizing Methods to Predict Soil classification According to the Soil Taxonomy and World Reference Base for Soil Resources

    Directory of Open Access Journals (Sweden)

    zohreh mosleh

    2017-02-01

    Full Text Available Introduction: Soil classification generally aims to establish a taxonomy based on breaking the soil continuum into homogeneous groups that can highlight the essential differences in soil properties and functions between classes.The two most widely used modern soil classification schemes are Soil Taxonomy (ST and World Reference Base for Soil Resources (WRB.With the development of computers and technology, digital and quantitative approaches have been developed. These new techniques that include the spatial prediction of soil properties or classes, relies on finding the relationships between soil and the auxiliary information that explain the soil forming factors or processes and finally predict soil patterns on the landscape. These approaches are commonly referred to as digital soil mapping (DSM (14. A key component of any DSM mapping activity is the method used to define the relationship between soil observation and auxiliary information (4. Several types of machine learning approaches have been applied for digital soil mapping of soil classes, such as logistic and multinomial logistic regressions (10,12, random forests (15, neural networks (3,13 and classification trees (22,4. Many decisions about the soil use and management are based on the soil differences that cannot be captured by higher taxonomic levels (i.e., order, suborder and great group (4. In low relief areas such as plains, it is expected that the soil forming factors are more homogenous and auxiliary information explaining soil forming factors may have low variation and cannot show the soil variability. Materials and Methods: The study area is located in the Shahrekord plain of Chaharmahal-Va-Bakhtiari province. According tothe semi-detailed soil survey (16, 120 pedons with approximate distance of 750 m were excavated and described according to the “field book for describing and sampling soils” (19. Soil samples were taken from different genetic horizons, air dried and

  1. Development of certified reference materials for accurate determination of fluoroquinolone antibiotics in chicken meat.

    Science.gov (United States)

    Hyung, Seok-Won; Lee, Chi-Ho; Kim, Byungjoo

    2017-08-15

    Certified reference materials (CRMs; KRISS CRM 108-03-003, 108-03-004) were developed for the accurate determination of fluoroquinolones (enrofloxacin and ciprofloxacin, respectively) in chicken meat. Two groups of chickens were cured with feeds containing enrofloxacin and ciprofloxacin, respectively. After slaughter, the thigh and breast meats were combined for the respective groups and the meat was freeze-dried, pulverized, sieved, and V-mixed. The final bulk material was bottled in 10g portions. For certification of the CRMs, isotope dilution-liquid chromatography/tandem mass spectrometry was used. The certified values of the CRMs were (19.06±0.86)mg/kg for enrofloxacin and (1.095±0.038)mg/kg for ciprofloxacin. The stabilities of the CRMs were monitored at -70°C for 12months, at -20°C for 2months, and at room temperature for 1month. Both CRM candidates were stable during the monitoring period for each temperature. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Size-selective poorly soluble particulate reference materials for evaluation of quantitative analytical methods.

    Science.gov (United States)

    Stefaniak, Aleksandr B; Turk, Gregory C; Dickerson, Robert M; Hoover, Mark D

    2008-07-01

    Owing to the absence of readily available certified particulate reference materials (RMs), most analytical methods used to determine particulate contaminant levels in workplace or other environments are validated using solution RMs, which do not assess the robustness of the digestion step for all forms and sizes of particles in a sample. A library of particulate RMs having a range of chemical forms and particle sizes is needed to support a shift in method evaluation strategies to include both solution and particulate RMs. In support of creating this library, we characterized bulk and physically size separated fractions of beryllium oxide (BeO) particles recovered from the machining fluid sludge of an industrial ceramic products grinding operation. Particles were large agglomerates of compact, crystalline BeO primary particles having diameters on the order of several micrometers. As expected, the particle surface area was independent of sieve size, with a range from 3.61 m(2)/g (53-63-microm fraction) to 4.82 m(2)/g (355-600-microm fraction). The density was near the theoretical value (3.01 g/cm(3)). The data support more detailed characterization of the sludge materials for use as size-selective RMs. This work illustrates an approach that can be used to develop RMs that are difficult to digest.

  3. Development of a certified reference material: ethanol in water - a practical case

    Directory of Open Access Journals (Sweden)

    Vanderléa de Souza

    2006-01-01

    Full Text Available The present work describes the development of a certified reference material (CRM composed of solutions of ethanol in water in five different concentrations, and all stages necessary for the development of an CRM, according to the guidelines of ISO GUIDES 30, 31, 32, 33, 34 and 35. The development of this CRM has been determined by Inmetro Rule n. 006 of 2002, which requires that all breath alcohol analyzers being used in Brazil shall have their respective models approved and that the subsequent verifications shall be performed based on tests with solutions of ethanol in water. As a result, the development of this CRM significantly contributes to the reliability of measurements performed with breath alcohol analyzers, with stated measurement uncertainty. Equally important, this development provides society with a CRM that may have multiple applications, not restricted to the verification of breath alcohol analyzers.O presente trabalho descreve o desenvolvimento de um material de referência certificado (MRC referente a soluções de etanol em água em cinco concentrações diferentes, abordando todas as etapas necessárias para o desenvolvimento de um MRC, conforme prescreve as ISO GUIDE 30, 31, 32, 33, 34 e 35. O desenvolvimento deste MRC originou-se nas determinações da Portaria Inmetro n° 006 de 2002, que assegura que todos os etilômetros a serem utilizados no Brasil deverão ter os seus modelos aprovados, e as verificações realizadas a partir de ensaios com soluções de etanol em água. Após um treinamento, em fevereiro de 2003, no The Federal Institute for Material Research and Testing - BAM, que é um instituto metrológico alemão designado, a Dquim iniciou o processo de desenvolvimento deste MRC, o qual foi concluído em agosto de 2004. No Inmetro desenvolveu-se inicialmente o procedimento de preparo individual, onde as soluções do MRC são preparadas em garrafas de 0,5 L. Atualmente está se estudando, no Inmetro, o

  4. New Organic Stable Isotope Reference Materials for Distribution through the USGS and the IAEA

    Science.gov (United States)

    Schimmelmann, Arndt; Qi, Haiping

    2014-05-01

    The widespread adoption of relative stable isotope-ratio measurements in organic matter by diverse scientific disciplines is at odds with the dearth of international organic stable isotopic reference materials (RMs). Only two of the few carbon (C) and nitrogen (N) organic RMs, namely L-glutamic acids USGS40 and USGS41 [1], both available from the U.S. Geological Survey (USGS) and the International Atomic Energy Agency (IAEA), provide an isotopically contrasting pair of organic RMs to enable essential 2-point calibrations for δ-scale normalization [2, 3]. The supply of hydrogen (H) organic RMs is even more limited. Numerous stable isotope laboratories have resorted to questionable practices, for example by using 'CO2, N2, and H2 reference gas pulses' for isotopic calibrations, which violates the principle of identical treatment of sample and standard (i.e., organic unknowns should be calibrated directly against chemically similar organic RMs) [4], or by using only 1 anchor instead of 2 for scale calibration. The absence of international organic RMs frequently serves as an excuse for indefensible calibrations. In 2011, the U.S. National Science Foundation (NSF) funded an initiative of 10 laboratories from 7 countries to jointly develop much needed new organic RMs for future distribution by the USGS and the IAEA. The selection of targeted RMs attempts to cover various common compound classes of broad technical and scientific interest. We had to accept compromises to approach the ideal of high chemical stability, lack of toxicity, and low price of raw materials. Hazardous gases and flammable liquids were avoided in order to facilitate international shipping of future RMs. With the exception of polyethylene and vacuum pump oil, all organic RMs are individual, chemically-pure substances, which can be used for compound-specific isotopic measurements in conjunction with liquid and gas chromatographic interfaces. The compounds listed below are under isotopic calibration by

  5. Development of palm-based reference materials for the quantification of fatty acids composition.

    Science.gov (United States)

    Tarmizi, Azmil Haizam Ahmad; Lin, Siew Wai; Kuntom, Ainie

    2008-01-01

    Characterisation of fatty acids composition of three palm-based reference materials was carried out through inter-laboratory proficiency tests. Twelve laboratories collaborated in these tests and the fatty acids compositions of palm oil, palm olein and palm stearin were determined by applying the MPOB Test Methods p3.4:2004 and p3.5:2004. Determination of consensus values and their uncertainties were based on the acceptable statistical agreement of results obtained from the collaborating laboratories. The consensus values and uncertainties (%) for each palm oil reference material produced are listed as follows : 0.20% (C12:0), 1.66+/-0.05% (C14:0), 43.39+/-0.39% (C16:0), 0.14+/-0.06% (C16:1), 3.90+/-0.11% (C18:0), 40.95+/-0.23% (C18:1), 9.68+/-0.21% (C18:2), 0.16+/-0.07% (C18:3) and 0.31+/-0.08% (C20:0) for fatty acids composition of palm oil; 0.23+/-0.04% (C12:0), 1.02+/-0.04% (C14:0), 39.66+/-0.19% (C16:0), 0.18+/-0.07% (C16:1), 3.81+/-0.04% (C18:0), 44.01+/-0.08% (C18:1), 10.73+/-0.08% (C18:2), 0.20+/-0.06% (C18:3) and 0.34+/-0.04% (C20:0) for fatty acids composition of palm olein; and 0.20% (C12:0), 1.14+/-0.05% (C14:0), 49.42+/-0.25% (C16:0), 0.16+/-0.08% (C16:1), 4.15+/-0.10% (C18:0), 36.14+/-0.77% (C18:1), 7.95+/-0.29% (C18:2), 0.11+/-0.07% (C18:3) and 0.30+/-0.08% (C20:0) for fatty acids composition of palm stearin.

  6. Retrospective Analysis of NIST Standard Reference Material 1450, Fibrous Glass Board, for Thermal Insulation Measurements.

    Science.gov (United States)

    Zarr, Robert R; Heckert, N Alan; Leigh, Stefan D

    2014-01-01

    Thermal conductivity data acquired previously for the establishment of Standard Reference Material (SRM) 1450, Fibrous Glass Board, as well as subsequent renewals 1450a, 1450b, 1450c, and 1450d, are re-analyzed collectively and as individual data sets. Additional data sets for proto-1450 material lots are also included in the analysis. The data cover 36 years of activity by the National Institute of Standards and Technology (NIST) in developing and providing thermal insulation SRMs, specifically high-density molded fibrous-glass board, to the public. Collectively, the data sets cover two nominal thicknesses of 13 mm and 25 mm, bulk densities from 60 kg·m(-3) to 180 kg·m(-3), and mean temperatures from 100 K to 340 K. The analysis repetitively fits six models to the individual data sets. The most general form of the nested set of multilinear models used is given in the following equation: [Formula: see text]where λ(ρ,T) is the predicted thermal conductivity (W·m(-1)·K(-1)), ρ is the bulk density (kg·m(-3)), T is the mean temperature (K) and ai (for i = 1, 2, … 6) are the regression coefficients. The least squares fit results for each model across all data sets are analyzed using both graphical and analytic techniques. The prevailing generic model for the majority of data sets is the bilinear model in ρ and T. [Formula: see text] One data set supports the inclusion of a cubic temperature term and two data sets with low-temperature data support the inclusion of an exponential term in T to improve the model predictions. Physical interpretations of the model function terms are described. Recommendations for future renewals of SRM 1450 are provided. An Addendum provides historical background on the origin of this SRM and the influence of the SRM on external measurement programs.

  7. Effective density of Aquadag and fullerene soot black carbon reference materials used for SP2 calibration

    Directory of Open Access Journals (Sweden)

    M. Gysel

    2011-08-01

    Full Text Available The mass and effective density of black carbon (BC particles generated from aqueous suspensions of Aquadag and fullerene soot was measured and parametrized as a function of their mobility diameter. The measurements were made by two independent research groups by operating a differential mobility analyser (DMA in series with an aerosol particle mass analyser (APM or a Couette centrifugal particle mass analyser (CPMA. Consistent and reproducible results were found in this study for different production lots of Aquadag, indicating that the effective density of these particles is a stable quantity and largely unaffected by differences in aerosol generation procedures and suspension treatments. The effective density of fullerene soot particles from one production lot was also found to be stable and independent of suspension treatments. Some difference to previous literature data was observed for both Aquadag and fullerene soot at larger particle diameters. Knowledge of the exact relationship between mobility diameter and particle mass is of great importance, as DMAs are commonly used to size-select particles from BC reference materials for calibration of single particle soot photometers (SP2, which quantitatively detect the BC mass in single particles.

  8. Certified reference material of bioethanol for metrological traceability in electrochemical parameters analyses.

    Science.gov (United States)

    Serta Fraga, Isabel Cristina; Ribeiro, Carla Matos; Sobral, Sidney Pereira; Dias, Júlio Cesar; Gonçalves, Mary Ane; Borges, Paulo Paschoal; Gonzaga, Fabiano Barbieri

    2012-09-15

    Bioethanol has become an important biofuel because it is a source of renewable energy and can help to decrease global warming. However, the quality of bioethanol needs to be guaranteed so that it can be trusted and accepted in international trade. The Brazilian Metrology Institute (Inmetro) has been developing a certified reference material (CRM) for bioethanol to ensure quality control for measurement in the bioethanol matrix. Inmetro has certified 11 quality parameters. Using these, the CRM of bioethanol will contribute to guaranteeing metrological traceability and reliable measurement results. These factors can be used to compare different bioethanols produced to comply with legislation in different countries in order to avoid technical barriers and thus increase the international trade in Brazilian bioethanol. The aim of this paper is to present the results of certification studies using three important electrochemical quality parameters in the CRM of bioethanol-total acid number, pHe and electrolytic conductivity-which are crucial in protecting the metallic parts of a vehicle from corrosion. The certified results obtained for total acid number, pHe and electrolytic conductivity parameters were (16.2±1.7)mg L(-1), 6.07±0.30, and (1.03±0.11)μS cm(-1), respectively. The uncertainties for all parameters were the expanded uncertainty obtained by multiplying the combined standard uncertainty by a coverage factor of k=2, which represents an approximately 95% confidence level.

  9. Effective density of Aquadag and fullerene soot black carbon reference materials used for SP2 calibration

    Directory of Open Access Journals (Sweden)

    M. Gysel

    2011-12-01

    Full Text Available The mass and effective density of black carbon (BC particles generated from aqueous suspensions of Aquadag and fullerene soot was measured and parametrized as a function of their mobility diameter. The measurements were made by two independent research groups by operating a differential mobility analyser (DMA in series with an aerosol particle mass analyser (APM or a Couette centrifugal particle mass analyser (CPMA. Consistent and reproducible results were found in this study for different production lots of Aquadag, indicating that the effective density of these particles is a stable quantity and largely unaffected by differences in aerosol generation procedures and suspension treatments. The effective density of fullerene soot particles from one production lot was also found to be stable and independent of suspension treatments. Some differences to previous literature data were observed for both Aquadag and fullerene soot at larger particle diameters. Knowledge of the exact relationship between mobility diameter and particle mass is of great importance, as DMAs are commonly used to size-select particles from BC reference materials for calibration of single particle soot photometers (SP2, which quantitatively detect the BC mass in single particles.

  10. A new Certified Reference Material for radionuclides in Irish sea sediment (IAEA-385)

    Energy Technology Data Exchange (ETDEWEB)

    Pham, M.K. [Marine Environment Laboratories, International Atomic Energy Agency, MC 98000 Principality of Monaco (Monaco)], E-mail: m.pham@iaea.org; Sanchez-Cabeza, J.A.; Povinec, P.P. [Marine Environment Laboratories, International Atomic Energy Agency, MC 98000 Principality of Monaco (Monaco); Andor, K. [Frederic Joliot-Curie National Research Inst. for Radiobiology and Radiohygiene, Anna u. 5, 1221 Budapest (Hungary); Arnold, D. [Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig (Germany); Benmansour, M. [Centre National de l' Energies des Sciences et des Techniques Nucleaires, 1382 Agdal, Rabat 10001 (Morocco); Bikit, I. [Dept. of Physics, Faculty of Science and Mathematics, University of Novi Sad, Trg Dositeja Obradovica 4, 21000 Novi Sad, Serbia (Serbia ); Carvalho, F.P. [Instituto Tecnologico e Nuclear, E.N. 10, P-2686-953 Sacavem (Portugal); Dimitrova, K. [Executive Environment Agency of Bulgaria, Regional Laboratory Varna, 4 Jan Palah Str., Varna 9000 (Bulgaria); Edrev, Z.H. [Regional Inspectorate of Environment and Waters, 2 Stara Planina str., 6000 Stara Zagora (Bulgaria); Engeler, C. [Radiochemistry Dept., Institute for Inland Water Management and Waste Water Treatment, P.O. Box 17, 8200 AA Lelystad (Netherlands); Fouche, F.J. [South African Nuclear Energy Corporation NECSA Ltd., P.O. Box 582, Pretoria 0001 (South Africa); Garcia-Orellana, J. [Dept. de Fisica, Universitat Automona de Barcelona, 08193-Cerdanyola del Valles (Spain); Gasco, C. [Instituto de Medio Ambiente, Radioecologia del Medio Acuatico, Av. de la Complutense 22, 28040 Madrid (Spain); Gastaud, J. [Marine Environment Labs., International Atomic Energy Agency, MC 98000 Principality of Monaco (Monaco); Gudelis, A. [Institute of Physics, Nuclear and Environmental Radioactivity Research Lab., Savanoriu Ave 231, 2053 Vilnius (Lithuania); Hancock, G. [CSIRO Land and Water, Clunies Ross St., GPO Box 1666, Canberra, ACT 2601 (Australia)] (and others)

    2008-11-15

    A new Certified Reference Material (CRM) for radionuclides in sediment (IAEA-385) is described and the results of the certification process are presented. Eleven radionuclides ({sup 40}K, {sup 137}Cs, {sup 226}Ra, {sup 228}Ra, {sup 230}Th, {sup 232}Th, {sup 234}U, {sup 238}U, {sup 238}Pu, {sup 239+240}Pu and {sup 241}Am) have been certified and information mass activities with 95% confidence intervals are given for seven other radionuclides ({sup 90}Sr, {sup 210}Pb({sup 210}Po), {sup 235}U, {sup 239}Pu, {sup 240}Pu and {sup 241}Pu). Results for less frequently reported radionuclides ({sup 60}Co, {sup 99}Tc, {sup 134}Cs, {sup 155}Eu, {sup 224}Ra and {sup 239}Np) and information on some activity and mass ratios are also reported. The CRM can be used for quality assurance/quality control of the analysis of radionuclides in sediment samples, for the development and validation of analytical methods and for training purposes.

  11. Results of {sup 14}C analysis on low-level reference materials

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, S.J.; Kotzer, T.G

    2000-04-01

    An invitation from the University of Glasgow to participate in an international intercomparison of {sup 14}C analysis and the increased need for quality assurance for measurements performed at the Low-Level Laboratory by AECL's Environmental Technologies Branch (ETB), Chalk River Laboratories, prompted the initiation of this work. Standard {sup 14}C samples from the IAEA and from the ETB were analyzed and compared to their reference values. All analyses agreed well with reported values and confirmed that the ETB can reliably measure {sup 14}C between 50 and 500 Bq/kg C. Samples from the University of Glasgow, Scotland, were also analyzed and reported. The results of counting various CO{sub 2} blank materials (dry ice from a CO{sub 2}-siphon and limestone) showed that the source of CO{sub 2} does not have an effect on background count rate or counter efficiency. The ETB's lower limit of detection (LLD) has been calculated to be 10 -20 Bq/kg C and the determination limit (L{sub Q}) for samples during the ETB's routine operations has been documented to be 44 Bq/kg C. (author)

  12. Development of hemoglobin A1c certified reference material by liquid chromatography isotope dilution mass spectrometry.

    Science.gov (United States)

    Bi, Jiaming; Wu, Liqing; Yang, Bin; Yang, Yi; Wang, Jing

    2012-04-01

    We report the development of a National Institute of Metrology (NIM) hemoglobin A(1c) (HbA(1c)) certified reference material (CRM). Each CRM unit contains about 10 μL of hemoglobin. Both hemoglobin and glycated hemoglobin were quantitatively determined by high-performance liquid chromatography (HPLC)-isotope dilution mass spectrometry (IDMS) with synthesized VHLTPE and glycated VHLTPE as standards. The mass fraction of synthesized VHLTPE or glycated VHLTPE was also quantitatively determined by HPLC-IDMS with NIM amino acid CRMs as standards. The homogeneity and stability of the CRMs were examined with a commercial HbA(1c) analyzer based on the HPLC principle. Fifteen units were randomly selected for homogeneity examination, and statistical analysis showed there was no inhomogeneity. Examination of the stability showed that the CRM was stable for at least 6 months at -80 °C. Uncertainty components of the balance, amino acid purity, hydrolysis and proteolysis efficiency, method reproducibility, homogeneity, and stability were taken into consideration for uncertainty evaluation. The certified value of NIM HbA(1c) CRM was expressed as the ratio of HbA(1c) to total hemoglobin in moles, and was (9.6 ± 1.9)%. The CRM can be used as a calibration or validation standard for clinical diagnostics. It is expected to improve the comparability for HbA(1c) measurement in China.

  13. Development of Certified Reference Materials for Diarrhetic Shellfish Poisoning Toxins, Part 1: Calibration Solutions.

    Science.gov (United States)

    Beach, Daniel G; Crain, Sheila; Lewis, Nancy; LeBlanc, Patricia; Hardstaff, William R; Perez, Ruth A; Giddings, Sabrina D; Martinez-Farina, Camilo F; Stefanova, Roumiana; Burton, Ian W; Kilcoyne, Jane; Melanson, Jeremy E; Quilliam, Michael A; McCarron, Pearse

    2016-09-01

    Okadaic acid (OA) and its analogs dinophysistoxins-1 (DTX1) and -2 (DTX2) are lipophilic polyethers produced by marine dinoflagellates. These toxins accumulate in shellfish and cause diarrhetic shellfish poisoning (DSP) in humans. Regulatory testing of shellfish is essential to safeguard public health and for international trade. Certified reference materials (CRMs) play a key role in analytical monitoring programs. This paper presents an overview of the interdisciplinary work that went into the planning, production, and certification of calibration-solution CRMs for OA, DTX1, and DTX2. OA and DTX1 were isolated from large-scale algal cultures and DTX2 from naturally contaminated mussels. Toxins were isolated by a combination of extraction and chromatographic steps with processes adapted to suit the source and concentration of each toxin. New 19-epi-DSP toxin analogs were identified as minor impurities. Once OA, DTX1, and DTX2 were established to be of suitable purity, solutions were prepared and dispensed into flame-sealed glass ampoules. Certification measurements were carried out using quantitative NMR spectroscopy and LC-tandem MS. Traceability of measurements was established through certified external standards of established purity. Uncertainties were assigned following standards and guidelines from the International Organization for Standardization, with components from the measurement, stability, and homogeneity studies being propagated into final combined uncertainties.

  14. Development of a Certified Reference Material (NMIJ CRM 7203-a) for Elemental Analysis of Tap Water.

    Science.gov (United States)

    Zhu, Yanbei; Narukawa, Tomohiro; Inagaki, Kazumi; Miyashita, Shin-Ichi; Kuroiwa, Takayoshi; Ariga, Tomoko; Kudo, Izumi; Koguchi, Masae; Heo, Sung Woo; Suh, Jung Ki; Lee, Kyoung-Seok; Yim, Yong-Hyeon; Lim, Youngran

    2017-01-01

    A certified reference material (CRM), NMIJ CRM 7203-a, was developed for the elemental analysis of tap water. At least two independent analytical methods were applied to characterize the certified value of each element. The elements certified in the present CRM were as follows: Al, As, B, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, Pb, Rb, Sb, Se, Sr, and Zn. The certified value for each element was given as the (property value ± expanded uncertainty), with a coverage factor of 2 for the expanded uncertainty. The expanded uncertainties were estimated while considering the contribution of the analytical methods, the method-to-method variance, the sample homogeneity, the long-term stability, and the concentrations of the standard solutions for calibration. The concentration of Hg (0.39 μg kg(-1)) was given as the information value, since loss of Hg was observed when the sample was stored at room temperature and exposed to light. The certified values of selected elements were confirmed by a co-analysis carried out independently by the NMIJ (Japan) and the KRISS (Korea).

  15. Development of Lentivirus-Based Reference Materials for Ebola Virus Nucleic Acid Amplification Technology-Based Assays.

    Science.gov (United States)

    Mattiuzzo, Giada; Ashall, James; Doris, Kathryn S; MacLellan-Gibson, Kirsty; Nicolson, Carolyn; Wilkinson, Dianna E; Harvey, Ruth; Almond, Neil; Anderson, Robert; Efstathiou, Stacey; Minor, Philip D; Page, Mark

    2015-01-01

    The 2013-present Ebola virus outbreak in Western Africa has prompted the production of many diagnostic assays, mostly based on nucleic acid amplification technologies (NAT). The calibration and performance assessment of established assays and those under evaluation requires reference materials that can be used in parallel with the clinical sample to standardise or control for every step of the procedure, from extraction to the final qualitative/quantitative result. We have developed safe and stable Ebola virus RNA reference materials by encapsidating anti sense viral RNA into HIV-1-like particles. The lentiviral particles are replication-deficient and non-infectious due to the lack of HIV-1 genes and Envelope protein. Ebola virus genes were subcloned for encapsidation into two lentiviral preparations, one containing NP-VP35-GP and the other VP40 and L RNA. Each reference material was formulated as a high-titre standard for use as a calibrator for secondary or internal standards, and a 10,000-fold lower titre preparation to serve as an in-run control. The preparations have been freeze-dried to maximise stability. These HIV-Ebola virus RNA reference materials were suitable for use with in-house and commercial quantitative RT-PCR assays and with digital RT-PCR. The HIV-Ebola virus RNA reference materials are stable at up to 37°C for two weeks, allowing the shipment of the material worldwide at ambient temperature. These results support further evaluation of the HIV-Ebola virus RNA reference materials as part of an International collaborative study for the establishment of the 1st International Standard for Ebola virus RNA.

  16. Glycerol as a reference material for fecal fat quantitation using low-resolution time domain ¹H NMR spectroscopy.

    Science.gov (United States)

    Corsetti, James P; Sterry, Judy; Sakpal, Manisha; Lefevre, Brian H; Ryan, Dan

    2011-11-01

    To assess glycerol as reference material for low-resolution time-domain (1)H NMR analysis of fecal fat. NMR analysis of fecal fat in stool samples with added glycerol was used to assess linearity, recovery, and relationship with NMR lipid signal. The study revealed for added glycerol excellent linearity (r=0.9998), recovery (101-104%), and linear relationship with simulated fecal fat content. Glycerol is an effective reference material for NMR fecal fat analysis. Copyright © 2011 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  17. Functioning in patients with schizophrenia: a systematic review of the literature using the International Classification of Functioning, Disability and Health (ICF) as a reference.

    Science.gov (United States)

    Gorostiaga, A; Balluerka, N; Guilera, G; Aliri, J; Barrios, M

    2017-03-01

    To identify and quantify the main concepts included in published studies focusing on individuals with schizophrenia using the International Classification of Functioning, Disability and Health (ICF). Searches (limited to those published from 2008 to 2012) were performed in MEDLINE, PsycINFO and CINAHL. Included studies described participants with schizophrenia, were original articles and included only subjects who were at least 18 years of age at study entry. All concepts underlying the measures and the text of the articles were extracted, and they were linked to ICF categories using standardized rules. From the 3584 abstracts retrieved, 348 were randomly selected, and of these, 206 studies met the inclusion criteria. A total of 17,141 concepts were extracted, 84.8% of which could be linked to 491 ICF categories: 222 (45.21%) of the categories referred to Body Functions, 29 (5.91%) to Body Structures, 186 (37.88%) to Activities and Participation and 54 (11%) to Environmental Factors. Seventy second-level categories were reported in at least 5% of all studies: 30 of these categories referred to Body Functions, 2 to Body Structures, 34 to Activities and Participation and 4 to Environmental Factors. The study has allowed us to identify and quantify the main concepts included in studies focusing on people with schizophrenia using the ICF. The majority of the concepts refer to Body Functions and Activities and Participation, rather than to Body Structures and Environmental Factors.

  18. 40 CFR 1060.810 - What materials does this part reference?

    Science.gov (United States)

    2010-07-01

    ... material. Table 2 to this section lists material from the Society of Automotive Engineers that we have... the Society of Automotive Engineers, 400 Commonwealth Drive, Warrendale, PA 15096 or http://www.sae.... (a) ASTM material. Table 1 to this section lists material from the American Society for Testing...

  19. Preparation and certification of the Polish reference material `Oriental Tobacco Leaves` (CTA-OTL-1) for inorganic trace analysis

    Energy Technology Data Exchange (ETDEWEB)

    Dybczynski, R.; Polkowska-Motrenko, H.; Samczynski, Z.; Szopa, Z. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1996-12-31

    A new Polish certified reference material `Oriental Tobacco Leaves` (CTA-OTL-1) for inorganic trace analysis was prepared. Fresh tobacco leaves of variety `Oriental` were dried, ground and sieved. All precautions were taken to avoid contamination of material with metals. The next step was homogenization. Preliminary homogeneity checking consisted in determining of Ca, Fe and K content by X-ray fluorescence. Final homogeneity testing was performed by neutron activation analysis determining Co, Cr, Fe and Rb. To assure long-term stability, the whole lot of material was sterilized by electron beam radiation. Certification of the candidate reference material was done on the basis of world-wide interlaboratory comparisons exercise in which 61 laboratories, using various analytical methods participated. (author). 30 refs, 12 tabs, 21 figs.

  20. Feasibility study for producing a carrot/potato matrix reference material for 11 selected pesticides at EU MRL level: material processing, homogeneity and stability assessment.

    Science.gov (United States)

    Saldanha, Helena; Sejerøe-Olsen, Berit; Ulberth, Franz; Emons, Hendrik; Zeleny, Reinhard

    2012-05-01

    The feasibility for producing a matrix reference material for selected pesticides in a carrot/potato matrix was investigated. A commercially available baby food (carrot/potato-based mash) was spiked with 11 pesticides at the respective EU maximum residue limits (MRLs), and further processed by either freezing or freeze-drying. Batches of some 150 units were produced per material type. First, the materials were assessed for the relative amount of pesticide recovered after processing (ratio of pesticide concentration in the processed material to the initially spiked pesticide concentration). In addition, the materials' homogeneity (bottle-to-bottle variation), and the short-term (1 month) and mid-term (5 months) stability at different temperatures were assessed. For this, an in-house validated GC-EI-MS method operated in the SIM mode with a sample preparation procedure based on the QuEChERS ("quick, easy, cheap, effective, rugged, and safe") principle was applied. Measurements on the frozen material provided the most promising results (smallest analyte losses during production), and also freeze-drying proved to be a suitable alternative processing technique for most of the investigated pesticides. Both the frozen and the freeze-dried material showed to be sufficiently homogeneous for the intended use, and storage at -20°C for 5 months did not reveal any detectable material degradation. The results constitute an important step towards the development of a pesticide matrix reference material. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Certified reference materials for testing of the presence/absence of Staphylococcus aureus enterotoxin A (SEA) in cheese.

    Science.gov (United States)

    Zeleny, Reinhard; Nia, Yacine; Schimmel, Heinz; Mutel, Isabelle; Hennekinne, Jacques-Antoine; Emteborg, Håkan; Charoud-Got, Jean; Auvray, Frédéric

    2016-08-01

    Staphylococcal enterotoxins (SEs) account for a substantial number of food-poisoning outbreaks. European legislation (Commission Regulation 1441/2007) stipulates the reference procedure for SE analysis in milk and dairy products, which is based on extraction, dialysis concentration and immunochemical detection using one of two approved assays (VIDAS(®) SET2, Ridascreen(®) SET Total). However, certified reference materials (CRMs) are lacking to support laboratories in performing reliable detection of Staphylococcus aureus enterotoxin A (SEA) in relevant matrices at sub-nanogram per gram levels. The certification of a set of three reference materials (blank and two SEA-containing materials) for testing of the presence/absence of SEA in cheese is described. The reference procedure was applied in an intercomparison with 15 laboratories, and results were reported in a qualitative manner (presence or absence of SEA in the sample). No false-negative or false-positive results were obtained. The certified values were stated as diagnostic specificity (blank material) or diagnostic sensitivity (SEA-containing materials) and were 100 % in all cases. Stability studies demonstrated suitable material stability when stored cooled or frozen. An in-house study on the recovery of SEA in the cheese materials using a double-sandwich enzyme-linked immunosorbent assay (ELISA) revealed comparable recovery values of around 45 % at the two spiking levels and in both the SEA-containing CRMs as well as blank CRM freshly spiked prior to analysis. The values were also comparable over time and among different analysts. The materials provide valuable support to laboratories for method validation and method performance verification and will increase the reliability of measuring SEA in cheese.

  2. Development of working reference materials of copper ore material%铜矿石二级标准物质的研制

    Institute of Scientific and Technical Information of China (English)

    梅连平; 云天化

    2011-01-01

    介绍了铜矿石二级标准物质的研制方法.进行了均匀性检验和稳定性检验并对其定值,结果显示该二级标准物质均匀性和稳定性以及定值准确性均达到国家标准物质的性能指标,符合国家计量技术规范的要求.%This paper introduced the development of working reference materials of copper ore material through the uniformity and stability testing and value definiting.The results showed that this working reference material's uniformity, stability and the accuracy of fixed value have reached the performance index of national standard materials, which have been up to the national metrological verification technical specification's requirements.

  3. Phosphated minerals to be used as radioactive reference materials; Minerais fosfatados para serem utilizados como materiais de referencia radioativos

    Energy Technology Data Exchange (ETDEWEB)

    Braganca, M.J.C.S.; Tauhata, L. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. Nacional de Metrologia das Radiacoes Ionizantes (LNMRI); Clain, A.F. [Universidade Severino Sombra, Vassouras, RJ (Brazil); Moreira, I. [Pontificia Univ. Catolica do Rio de Janeiro (PUC/Rio), RJ (Brazil). Dept. de Quimica

    2003-07-01

    The production and the supplying of certified reference materials, or deliberated contaminated materials containing natural radionuclides for laboratories which analyses environmental samples are fundamentals for the correct measurements of their radioactive levels. This analysis quality represents a important step for the safeguards of the population health, and quality control of the imported and exported products, such as minerals, agricultural and raw materials. The phosphate rocks, containing significant concentrations of thorium, and used as raw material and fertilizers justified a study for better characterization and distinction to be used cas certified reference radioactive materials. Therefore, samples from the two carboanalytical-alkaline chimneys (Araxa and Catalao), and one from metasedimentar origin (Patos de Minas), distant 100 km from each other, were collected and chemical and cholecystographic characterized by optical emission, X-ray diffraction and fluorescence. The element concentrations were determined by neutron activation analysis, ICP-MS and ICP-AES. The results, after multivariate statistical analysis and study of correlations among elements, have shown geochemical similarities of the phosphates from Araxa and Catalao, and differences from Patos de Minas, despite of the geographic proximity. The concentration of thorium between 200 and 500 (mg/g) allows to use such minerals as reference materials.

  4. Preparation and characterisation of in-house reference material of tylosin in honey and results of a proficiency test.

    Science.gov (United States)

    Bohm, Detlef A; Stachel, Carolin S; Hackenberg, Rudolf; Gowik, Petra

    2011-08-26

    The analysis of incurred material from animals treated with pharmacologically active substances is an efficient way to check the accuracy of a method. Tylosin A was chosen for the preparation of that material because it is highly effective in controlling active infections of American Foulbrood (AFB), a global threat to apiculture, but residues in honey are not allowed according to European legislation. For this reason an in-house reference material of honey containing the macrolide tylosin A and its degradation product desmycosin (tylosin B) was prepared. After the treatment of a beehive with the appropriate macrolide tylosin A, the honey samples were collected. The incurred honey material was diluted by mixing with blank honey. Concentrations of 25.81 μg kg(-1) for tylosin A and of 19.28 μg kg(-1) for its degradation product desmycosin (tylosin B) were reached. The homogeneity was checked by analysing 12 bottles in duplicate. The stability was tested at different defined temperatures and storage conditions. The reference material described above was homogeneous and stable. Samples of this in-house reference material were used for the realisation of a proficiency test with international participation. All participants accomplished satisfying results with the exception of one laboratory. Copyright © 2011. Published by Elsevier B.V.

  5. Report on Childhood Obesity in China (2)Verification of BMI Classification Reference for Overweight and Obesity in Chinese Children and Adolescents

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective To verify Working Group for Obesity in China (WGOC) recommended body mass index (BMI) classification reference for overweight and obesity in Chinese children and adolescents using the data of 2002 China Nationwide Nutrition and Health Survey. Methods Pediatric metabolic syndrome (MetS) and abnormality of each risk factor for MetS were defined using the criteria for US adolescents. Definition of hyper-TC, LDL, and dyslipidemia in adults was applied as well. The average level and abnormality rate of the metabolic indicators were described by BMI percentiles and compared with general linear model analysis. Receiver operating characteristic analysis was used to summarize the potential of BMI to discriminate between thepresence and absence of the abnormality of these indicators. Results There was neither significantly increasing nor significantly decreasing trend of biochemical parameter levels in low BMI percentile range (<65th). Slight increasing trend from the 75th and a significant increase were found when BMI≥85th percentile. In general, the prevalence of the examined risk factors varied slightly when BMI percentile<75th, and substantial increases were consistently seen when BMI percentile≥75th. As an indicator of hyper-TG, hypertension and MetS, the sensitivity and specificity were equal at the point of BMI<75th percentile, and the Youden's index of risk factors also reached peak point before 75th percentile except for MetS. When the BMI percentile was used as the screening indicator of MetS, Youden's index reached peak point at 85th percentile, just the point in the ROC graph that was nearest to the upper left corner. Conclusion The BMI classification reference for overweight and obesity recommended by WGOC is rational to predict and prevent health risks in Chinese children and adolescents. Lower screening cut-off points, such as 83th percentile or 80th percentile, should not be excluded when they are considered as overweight criteria in

  6. Development of a reference material for Staphylococcus aureus enterotoxin A in cheese: feasibility study, processing, homogeneity and stability assessment.

    Science.gov (United States)

    Zeleny, R; Emteborg, H; Charoud-Got, J; Schimmel, H; Nia, Y; Mutel, I; Ostyn, A; Herbin, S; Hennekinne, J-A

    2015-02-01

    Staphylococcal food poisoning is caused by enterotoxins excreted into foods by strains of staphylococci. Commission Regulation 1441/2007 specifies thresholds for the presence of these toxins in foods. In this article we report on the progress towards reference materials (RMs) for Staphylococcal enterotoxin A (SEA) in cheese. RMs are crucial to enforce legislation and to implement and safeguard reliable measurements. First, a feasibility study revealed a suitable processing procedure for cheese powders: the blank material was prepared by cutting, grinding, freeze-drying and milling. For the spiked material, a cheese-water slurry was spiked with SEA solution, freeze-dried and diluted with blank material to the desired SEA concentration. Thereafter, batches of three materials (blank; two SEA concentrations) were processed. The materials were shown to be sufficiently homogeneous, and storage at ambient temperature for 4weeks did not indicate degradation. These results provide the basis for the development of a RM for SEA in cheese.

  7. Classification of octet AB-type binary compounds using dynamical charges: A materials informatics perspective

    Science.gov (United States)

    Pilania, G.; Gubernatis, J. E.; Lookman, T.

    2015-12-01

    The role of dynamical (or Born effective) charges in classification of octet AB-type binary compounds between four-fold (zincblende/wurtzite crystal structures) and six-fold (rocksalt crystal structure) coordinated systems is discussed. We show that the difference in the dynamical charges of the fourfold and sixfold coordinated structures, in combination with Harrison’s polarity, serves as an excellent feature to classify the coordination of 82 sp-bonded binary octet compounds. We use a support vector machine classifier to estimate the average classification accuracy and the associated variance in our model where a decision boundary is learned in a supervised manner. Finally, we compare the out-of-sample classification accuracy achieved by our feature pair with those reported previously.

  8. Classification of phosphogypsum as a waste material from the aspect of environmental protection

    Directory of Open Access Journals (Sweden)

    Rajković Miloš B.

    2004-01-01

    Full Text Available Phosphogypsum is primarily classified as a heavy waste. The classification of phosphogypsum as dangerous waste may be only maintained under the condition that phosphates with the highest content of radio nuclides are used in the production of H3PO4 by the so called "wet procedure" (Morocco, Florida, which, due to the great quantity of present radio nuclides, causes considerable environmental pollution by radon. The classification of phosphogypsum as a separate category of radioactive waste may be conditionally accepted, because phosphogypsum is not a radioactive waste. All the instructions about the collection, documentation and storage of phosphogypsum so far on disposal sites, and possible transport, also due to non-existing legal recommendations must comply with the classification of phosphogypsum as dangerous waste.

  9. Development of a genomic DNA reference material panel for myotonic dystrophy type 1 (DM1) genetic testing.

    Science.gov (United States)

    Kalman, Lisa; Tarleton, Jack; Hitch, Monica; Hegde, Madhuri; Hjelm, Nick; Berry-Kravis, Elizabeth; Zhou, Lili; Hilbert, James E; Luebbe, Elizabeth A; Moxley, Richard T; Toji, Lorraine

    2013-07-01

    Myotonic dystrophy type 1 (DM1) is caused by expansion of a CTG triplet repeat in the 3' untranslated region of the DMPK gene that encodes a serine-threonine kinase. Patients with larger repeats tend to have a more severe phenotype. Clinical laboratories require reference and quality control materials for DM1 diagnostic and carrier genetic testing. Well-characterized reference materials are not available. To address this need, the Centers for Disease Control and Prevention-based Genetic Testing Reference Material Coordination Program, in collaboration with members of the genetic testing community, the National Registry of Myotonic Dystrophy and Facioscapulohumeral Muscular Dystrophy Patients and Family Members, and the Coriell Cell Repositories, has established and characterized cell lines from patients with DM1 to create a reference material panel. The CTG repeats in genomic DNA samples from 10 DM1 cell lines were characterized in three clinical genetic testing laboratories using PCR and Southern blot analysis. DMPK alleles in the samples cover four of five DM1 clinical categories: normal (5 to 34 repeats), mild (50 to 100 repeats), classical (101 to 1000 repeats), and congenital (>1000 repeats). We did not identify or establish Coriell cell lines in the premutation range (35 to 49 repeats). These samples are publicly available for quality control, proficiency testing, test development, and research and should help improve the accuracy of DM1 testing.

  10. Certified reference materials for radionuclides in Bikini Atoll sediment (IAEA-410) and Pacific Ocean sediment (IAEA-412)

    DEFF Research Database (Denmark)

    Pham, M. K.; van Beek, P.; Carvalho, F. P.

    2016-01-01

    The preparation and characterization of certified reference materials (CRMs) for radionuclide content in sediments collected offshore of Bikini Atoll (IAEA-410) and in the open northwest Pacific Ocean (IAEA-412) are described and the results of the certification process are presented. The certifi...

  11. Doorways II: Community Counselor Reference Materials. On School-Related Gender-Based Violence Prevention and Response

    Science.gov (United States)

    US Agency for International Development, 2009

    2009-01-01

    The Doorways training program was designed by the U.S. Agency for International Development (USAID)-funded Safe Schools Program (Safe Schools) to enable teachers, community members and students to prevent and respond to school-related gender-based violence (SRGBV). This booklet, "Doorways II: Community Counselor Reference Materials on…

  12. Quantification of the predominant monomeric catechins in baking chocolate standard reference material by LC/APCI-MS.

    Science.gov (United States)

    Nelson, Bryant C; Sharpless, Katherine E

    2003-01-29

    Catechins are polyphenolic plant compounds (flavonoids) that may offer significant health benefits to humans. These benefits stem largely from their anticarcinogenic, antioxidant, and antimutagenic properties. Recent epidemiological studies suggest that the consumption of flavonoid-containing foods is associated with reduced risk of cardiovascular disease. Chocolate is a natural cocoa bean-based product that reportedly contains high levels of monomeric, oligomeric, and polymeric catechins. We have applied solid-liquid extraction and liquid chromatography coupled with atmospheric pressure chemical ionization-mass spectrometry to the identification and determination of the predominant monomeric catechins, (+)-catechin and (-)-epicatechin, in a baking chocolate Standard Reference Material (NIST Standard Reference Material 2384). (+)-Catechin and (-)-epicatechin are detected and quantified in chocolate extracts on the basis of selected-ion monitoring of their protonated [M + H](+) molecular ions. Tryptophan methyl ester is used as an internal standard. The developed method has the capacity to accurately quantify as little as 0.1 microg/mL (0.01 mg of catechin/g of chocolate) of either catechin in chocolate extracts, and the method has additionally been used to certify (+)-catechin and (-)-epicatechin levels in the baking chocolate Standard Reference Material. This is the first reported use of liquid chromatography/mass spectrometry for the quantitative determination of monomeric catechins in chocolate and the only report certifying monomeric catechin levels in a food-based Standard Reference Material.

  13. A regional classification scheme for estimating reference water quality in streams using land-use-adjusted spatial regression-tree analysis

    Science.gov (United States)

    Robertson, D.M.; Saad, D.A.; Heisey, D.M.

    2006-01-01

    Various approaches are used to subdivide large areas into regions containing streams that have similar reference or background water quality and that respond similarly to different factors. For many applications, such as establishing reference conditions, it is preferable to use physical characteristics that are not affected by human activities to delineate these regions. However, most approaches, such as ecoregion classifications, rely on land use to delineate regions or have difficulties compensating for the effects of land use. Land use not only directly affects water quality, but it is often correlated with the factors used to define the regions. In this article, we describe modifications to SPARTA (spatial regression-tree analysis), a relatively new approach applied to water-quality and environmental characteristic data to delineate zones with similar factors affecting water quality. In this modified approach, land-use-adjusted (residualized) water quality and environmental characteristics are computed for each site. Regression-tree analysis is applied to the residualized data to determine the most statistically important environmental characteristics describing the distribution of a specific water-quality constituent. Geographic information for small basins throughout the study area is then used to subdivide the area into relatively homogeneous environmental water-quality zones. For each zone, commonly used approaches are subsequently used to define its reference water quality and how its water quality responds to changes in land use. SPARTA is used to delineate zones of similar reference concentrations of total phosphorus and suspended sediment throughout the upper Midwestern part of the United States. ?? 2006 Springer Science+Business Media, Inc.

  14. Certification of reference materials by energy-dispersive x-ray fluorescence spectrometry?

    DEFF Research Database (Denmark)

    Christensen, Leif Højslet; Heydorn, Kaj

    1985-01-01

    This paper studies the precision and accuracy that can be achieved using energy-dispersive x-ray fluorescence spectrometry for the determination of total sulphur content in BCR 38 Fly Ash issued by the European Community Bureau of Reference....

  15. Certified reference materials for organic contaminants for use in monitoring of the aquatic environment

    NARCIS (Netherlands)

    Boer, de J.; McGovern, E.

    2001-01-01

    Over the last three decades organic contaminants have been of increasing importance in environmental monitoring. Dioxins, furans, polychlorinated biphenyls and organochlorine pesticides have determined the environmental research agenda. This has led to an increasing demand for certified reference

  16. IgG subclass concentrations in certified reference material 470 and reference values for children and adults determined with the binding site reagents.

    Science.gov (United States)

    Schauer, Uwe; Stemberg, Frank; Rieger, Christian H L; Borte, Michael; Schubert, Simone; Riedel, Frank; Herz, Udo; Renz, Harald; Wick, Manfred; Carr-Smith, Hugh D; Bradwell, Arthur R; Herzog, Wilhelm

    2003-11-01

    There is currently no international reference preparation for IgG subclass (IgGSc) quantification. This situation has led to calibration differences among assays and a variety of reference interval values with consequential difficulties in comparing results. We therefore evaluated IgGSc concentrations in Certified Reference Material 470 (CRM 470). Pure, polyclonal IgG1, -2, -3, and -4 were prepared from a large serum pool for use as primary standards. The IgG mass in each preparation was calculated from amino-acid analysis data. IgGSc concentrations were assessed in CRM 470 by nephelometry with modern analytical techniques, using these reference preparations. Subsequently, IgGSc concentrations were measured in 380 healthy individuals (250 males and 130 females), and age-dependent reference intervals were established. IgGSc concentrations in CRM 470 were as follows: IgG1, 5028 mg/L; IgG2, 3418 mg/L; IgG3, 579 mg/L, and IgG4, 381 mg/L, with a total IgG concentration of 9406 mg/L, 2.83% below the certified total IgG value of 9680 mg/L. Age-dependent percentile curves for the four IgGSc were constructed using a Box-Cox transformation. Maximum median values were as follows: IgG1, 6.02 g/L at 11 years; IgG2, 3.45 g/L at 31 years; IgG3, 0.63 g/L at 17 years; and IgG4, 0.48 g/L at 14 years. No significant sex-related differences were observed. The correlation between the summation of individual IgGSc and separate measurements of total IgG concentrations was good and supports the accuracy of the results. The results are based on The Binding Site assays and should not be considered appropriate for other assays unless so demonstrated.

  17. Monazite RW-1: a homogenous natural reference material for SIMS U-Pb and Th-Pb isotopic analysis

    Science.gov (United States)

    Ling, Xiao-Xiao; Huyskens, Magdalena H.; Li, Qiu-Li; Yin, Qin-Zhu; Werner, Ronald; Liu, Yu; Tang, Guo-Qiang; Yang, Ya-Nan; Li, Xian-Hua

    2016-10-01

    Well-characterized matrix-matched natural mineral references of known age are an important prerequisite for SIMS (secondary ion mass spectrometry) U-Th-Pb dating. We have characterized RW-1, a 44 g yellowish-brown single monazite specimen from a Norwegian pegmatite as an excellent hi-Th reference material for secondary ion mass spectrometric U-Th-Pb dating. A total of 206 secondary ion mass spectrometric analyses over six analytical sessions were performed on different monazite fragments of RW-1. The analyses resulted in 207Pb-based common lead corrected 206Pb/238U ages and Th-Pb ages with overall 2 % (2 SD = standard deviation) variations, indicating the good U-Th-Pb system homogeneity. The homogeneity of Th content of 11.8 ± 1.0 wt% (2 SD) and Th/U of 42 ± 3 (2 SD) make this crystal also a good compositional reference material. We used the combined ID-TIMS(Pb)/ID-MC-ICP-MS(U) technique (i.e. isotope dilution thermal ionization mass spectrometry for Pb, and isotope dilution multi-collector inductively-coupled plasma mass spectrometry for U) to determine U-Pb ages of the monazite samples studied. The mean 207Pb/235U age of 904.15 ± 0.26 Ma (95 % confidence level) is recommended as the best estimate crystallization age for RW-1 monazite. Considering that the most commonly distributed U-Pb monazite reference materials have rather low ThO2, we suggest that this RW-1 monazite with its ThO2 of 13.5 wt% is a suitable reference material providing investigators more confidence when dating high-Th monazite unknowns.

  18. 火药比容标准物质的研制%Development of Reference Material of Propellant Specific Volume

    Institute of Scientific and Technical Information of China (English)

    赵宏立; 刘来东; 靳建伟; 赵宝明; 宋长文

    2013-01-01

    A reference material, mainly composed of nitrocellulose (NC),nitroglycerine (NG), centralite and vaseline ,was developed for verifying instruments specific volume of propellant. The homogeneity of characteristic value of the reference material was tested by means of the variance analysis method, and its stability had been examined for more than one year. The reference material of propellant specific volume was determined by multi-department based on same principles, and the certified result was 627.2L/kg. The combined standard uncertainty and expanded uncertainty of standard value of reference material were also evaluated, and the expanded uncertainty was determined 9.0L/kg(k=2). The result showed that the reference material had good homogeneity and stability, its characteristic value was accurate and reliable. The reference material could meet the requirement of transferring the certified value of specific volume, calibrate and verify the instruments specific volume of propellant.%研制了以硝化棉、硝化甘油、中定剂和凡士林为主要成分的火药比容标准物质,采用方差分析方法检验了标准物质的均匀性,并进行了1a以上的稳定性考核;通过多家单位采用同一原理方法进行标准物质定值,分析评估了标准物质标准值的合成标准不确定度和扩展不确定度,得到标准比容值为627.2L/kg,扩展不确定度为9.0L/kg(k=2)。结果表明,该标准物质特性量值准确、可靠,均匀性和稳定性好,能够满足火药比容量值传递的要求,达到校准和检定火药比容测量仪的目的。

  19. Preparation of two biological reference materials for QUASIMEME inter-laboratory testing

    NARCIS (Netherlands)

    Lohman, M.; Korytar, P.

    2007-01-01

    Two biological materials have been prepared for the Institute for Environmental Studies (IVM), Free University, Amsterdam to be used in QUASIMEME interlaboratory studies. The materials prepared are: 300 tins of homogenized blue mussels from the Waddenzee (QO07-1) and 300 tins of homogenized shrimps

  20. GUIDANCE FOR THE PROPER CHARACTERIZATION AND CLASSIFICATION OF LOW SPECIFIC ACTIVITY MATERIALS AND SURFACE CONTAMINATED OBJECTS FOR DISPOSAL

    Energy Technology Data Exchange (ETDEWEB)

    PORTSMOUTH JH; BLACKFORD LT

    2012-02-13

    Regulatory concerns over the proper characterization of certain waste streams led CH2M HILL Plateau Remediation Company (CHPRC) to develop written guidance for personnel involved in Decontamination & Decommissioning (D&D) activities, facility management and Waste Management Representatives (WMRs) involved in the designation of wastes for disposal on and off the Hanford Site. It is essential that these waste streams regularly encountered in D&D operations are properly designated, characterized and classified prior to shipment to a Treatment, Storage or Disposal Facility (TSDF). Shipments of waste determined by the classification process as Low Specific Activity (LSA) or Surface Contaminated Objects (SCO) must also be compliant with all applicable U.S. Department of Transportation (DOE) regulations as well as Department of Energy (DOE) orders. The compliant shipment of these waste commodities is critical to the Hanford Central Plateau cleanup mission. Due to previous problems and concerns from DOE assessments, CHPRC internal critiques as well as DOT, a management decision was made to develop written guidance and procedures to assist CHPRC shippers and facility personnel in the proper classification of D&D waste materials as either LSA or SCO. The guidance provides a uniform methodology for the collection and documentation required to effectively characterize, classify and identify candidate materials for shipping operations. A primary focus is to ensure that waste materials generated from D&D and facility operations are compliant with the DOT regulations when packaged for shipment. At times this can be difficult as the current DOT regulations relative to the shipment of LSA and SCO materials are often not clear to waste generators. Guidance is often sought from NUREG 1608/RAMREG-003 [3]: a guidance document that was jointly developed by the DOT and the Nuclear Regulatory Commission (NRC) and published in 1998. However, NUREG 1608 [3] is now thirteen years old and

  1. Thermal desorption GC-MS as a tool to provide PAH certified standard reference material on particulate matter quartz filters.

    Science.gov (United States)

    Grandesso, Emanuela; Pérez Ballesta, Pascual; Kowalewski, Konrad

    2013-02-15

    Reference materials for particulate matter (PM) on filter media are not available for the quantification of polycyclic aromatic hydrocarbons (PAHs) in ambient air. This is due to the difficulty of obtaining reference material that has a homogeneous distribution on a filter surface that is large enough for characterization and distribution. High volume sample filters from different locations and seasons were considered to validate the feasibility of the use of quartz filters as reference material for PAH concentrations. A rapid thermal desorption (TD) technique coupled with gas chromatography/mass spectroscopy was applied to characterise the material for the content of fifteen different PAHs. TD technique allowed for rapid and accurate analysis of small sections of filter (5mm diameter), leaving enough material for the production of twenty sub-filter cuts (42 mm diameter) that could be used for distribution and control. Stability and homogeneity tests required for material certification were performed as indicated by the ISO guide 34:2009 and ISO 35:2006. The contribution of the heterogeneous distribution of PAHs on the filter surface resulted generally lower than 10% and higher for more volatile PAHs. One year of storage at -18°C indicated no significant variation in PAH concentrations. Nevertheless, a methodology for shipping and storing of the filter material at ambient temperature in especially designed plastic envelopes, was also shown to allow for stabile concentrations within twenty days. The method accuracy was confirmed by the analysis of NIST SRM 1649a (urban dust) and PAH concentrations were validated against the reference values obtained from an inter-laboratory exercise. In the case of benzo[a]pyrene for masses quantified between 100 pg and 10 ng the TD method provided expanded uncertainties of circa 10%, while the inter-laboratory reference value uncertainties ranged between 15 and 20%. The evaluation of these results supports the use of the presented

  2. Using the International Classification of Functioning, Disability and Health (ICF to describe children referred to special care or paediatric dental services.

    Directory of Open Access Journals (Sweden)

    Denise Faulks

    Full Text Available Children in dentistry are traditionally described in terms of medical diagnosis and prevalence of oral disease. This approach gives little information regarding a child's capacity to maintain oral health or regarding the social determinants of oral health. The biopsychosocial approach, embodied in the International Classification of Functioning, Disability and Health - Child and Youth version (ICF-CY (WHO, provides a wider picture of a child's real-life experience, but practical tools for the application of this model are lacking. This article describes the preliminary empirical study necessary for development of such a tool - an ICF-CY Core Set for Oral Health. An ICF-CY questionnaire was used to identify the medical, functional, social and environmental context of 218 children and adolescents referred to special care or paediatric dental services in France, Sweden, Argentina and Ireland (mean age 8 years ± 3.6 yrs. International Classification of Disease (ICD-10 diagnoses included disorders of the nervous system (26.1%, Down syndrome (22.0%, mental retardation (17.0%, autistic disorders (16.1%, and dental anxiety alone (11.0%. The most frequently impaired items in the ICF Body functions domain were 'Intellectual functions', 'High-level cognitive functions', and 'Attention functions'. In the Activities and Participation domain, participation restriction was frequently reported for 25 items including 'Handling stress', 'Caring for body parts', 'Looking after one's health' and 'Speaking'. In the Environment domain, facilitating items included 'Support of friends', 'Attitude of friends' and 'Support of immediate family'. One item was reported as an environmental barrier - 'Societal attitudes'. The ICF-CY can be used to highlight common profiles of functioning, activities, participation and environment shared by children in relation to oral health, despite widely differing medical, social and geographical contexts. The results of this empirical

  3. Standard Practice for Design, Manufacture, and Material Grouping Classification of Hole-Type Image Quality Indicators (IQI) Used for Radiology

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 This practice covers the design, material grouping classification, and manufacture of hole-type image quality indicators (IQI) used to indicate the quality of radiologic images. 1.2 This practice is applicable to X-ray and gamma-ray radiology. 1.3 The values stated in inch-pound units are to be regarded as standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  4. Interactive Classification of Construction Materials: Feedback Driven Framework for Annotation and Analysis of 3d Point Clouds

    Science.gov (United States)

    Hess, M. R.; Petrovic, V.; Kuester, F.

    2017-08-01

    Digital documentation of cultural heritage structures is increasingly more common through the application of different imaging techniques. Many works have focused on the application of laser scanning and photogrammetry techniques for the acquisition of threedimensional (3D) geometry detailing cultural heritage sites and structures. With an abundance of these 3D data assets, there must be a digital environment where these data can be visualized and analyzed. Presented here is a feedback driven visualization framework that seamlessly enables interactive exploration and manipulation of massive point cloud data. The focus of this work is on the classification of different building materials with the goal of building more accurate as-built information models of historical structures. User defined functions have been tested within the interactive point cloud visualization framework to evaluate automated and semi-automated classification of 3D point data. These functions include decisions based on observed color, laser intensity, normal vector or local surface geometry. Multiple case studies are presented here to demonstrate the flexibility and utility of the presented point cloud visualization framework to achieve classification objectives.

  5. 中国食材分类方法浅析%Shallow analysis of classification method of China food material

    Institute of Scientific and Technical Information of China (English)

    柴可夫; 谷英敏; 马纲

    2011-01-01

    Things of one kind come together. To partition the material according to the varityis the premise of understanding and using the substance. By means of analyzing the evolution of classification method of the ancient drug herbs, food herbs, it is concluded that the classification method is formed and developed gradually to be accompanied with the development of drug properties and food properties, meanwhile, the classification method and can promote people to know and utilize the drug properties and food properties.%物以类聚,按类划分物质是认识了解使用该物质的前题,通过对古代药物本草、食物本草的分类方法的演变分析,得出分类方法是伴随着药性、食性的发展而逐步形成发展起来的,同时分类方法又能促进人们对食性、药性的认识和利用.

  6. Certified reference material for the quality control of cadmium, copper nickel and zinc determination in estuarine water (CRM 505)

    Energy Technology Data Exchange (ETDEWEB)

    Quevauviller, P. [European Commission, Standards, Measurement and Testing Programme, Brussels (Belgium); Kramer, K.J.M. [IMW-TNO, Laboratory for Applied Marine Research P.O. Box 57, NL-1780 AB Den Helder (Netherlands); Vinhas, T. [Instituto Hidrografico, rua das Trinas 49, P-1200 Lisbon (Portugal)

    1996-02-01

    Analyses of estuarine water samples are routinely carried out by a number of laboratories to monitor the level of environmental contamination by toxic substances, e.g. heavy metals. A series of interlaboratory studies has been organised by the Community Bureau of Reference, BCR (now renamed Standards, Measurements and Testing Programme) to improve the quality of the determinations of selected trace metals in estuarine water samples. The improvement achieved allowed to produce a reference material (CRM 505) which was certified for its content of Cd, Cu, Ni and Zn. Further improvements were considered to be necessary for the certification of other trace elements, e.g. Pb. This material was collected in the Tagus Estuary, carefully prepared (filtered and acidified) and its homogeneity and long term stability were verified. This paper presents the work performed for the certification of Cd, Cu, Ni and Zn. Indicative values are reported for As, Co, Fe, Mn, Pb and V. (orig.). With 5 figs., 6 tabs.

  7. Certified reference material for the quality control of cadmium, copper nickel and zinc determination in estuarine water (CRM 505).

    Science.gov (United States)

    Quevauviller, P; Kramer, K J; Vinhas, T

    1996-02-01

    Analyses of estuarine water samples are routinely carried out by a number of laboratories to monitor the level of environmental contamination by toxic substances, e.g. heavy metals. A series of interlaboratory studies has been organised by the Community Bureau of Reference, BCR (now renamed Standards, Measurements and Testing Programme) to improve the quality of the determinations of selected trace metals in estuarine water samples. The improvement achieved allowed to produce a reference material (CRM 505) which was certified for its content of Cd, Cu, Ni and Zn. Further improvements were considered to be necessary for the certification of other trace elements, e.g. Pb. This material was collected in the Tagus Estuary, carefully prepared (filtered and acidified) and its homogeneity and long term stability were verified. This paper presents the work performed for the certification of Cd, Cu, Ni and Zn. Indicative values are reported for As, Co, Fe, Mn, Pb and V.

  8. Material investigation for manufacturing of reference step gauges for CT scanning verification

    DEFF Research Database (Denmark)

    Cantatore, Angela; Angel, Jais Andreas Breusch; De Chiffre, Leonardo

    2012-01-01

    This work deals with the study of stability and material investigation for manufacturing of step gauges for CT scanning verification. Four replica step gauges were fabricated using a bisacryl material for dental applications and the stability over five months was monitored using a tactile CMM....... The material was unstable, probably due to a modification of the chemical composition which lowered the hardness. New step gauges were manufactured through milling. Polyetheretherketone (PEEK) and Polyp-phenylenesulphide (PPS with 40% glass) fulfil the requirements regarding hardness and mechanical properties...... and two series of five step gauges (one series for each material) were manufactured by milling. Results show a significant improvement in terms of form stability and surface geometry quality of the new step gauges with respect to the replica step gauges in Luxabite, as reported below....

  9. Certified reference material for radionuclides in fish flesh sample IAEA-414 (mixed fish from the Irish Sea and North Sea)

    DEFF Research Database (Denmark)

    Pham, M.K.; Sanchez-Cabeza, J.A.; Povinec, P.P.

    2006-01-01

    ratios are also included. The CRM can be used for quality assurance/quality control of the analysis of radionuclides in fish sample, for the development and validation of analytical methods and for training purposes. The material is available from IAEA, Vienna, in 100 g units. (c) 2006 Elsevier Ltd. All......A certified reference material (CRM) for radionuclides in fish sample IAEA-414 (mixed fish from the Irish Sea and North Seas) is described and the results of the certification process are presented. Nine radionuclides (K-40, Cs-137, Th-232, U-234, U-235, U-238, Pu-238, Pu239+240 and Am-241) were...

  10. Comprehensive Pb-Sr-Nd-Hf isotopic, trace element, and mineralogical characterization of mafic to ultramafic rock reference materials

    Science.gov (United States)

    Fourny, Anaïs.; Weis, Dominique; Scoates, James S.

    2016-03-01

    Controlling the accuracy and precision of geochemical analyses requires the use of characterized reference materials with matrices similar to those of the unknown samples being analyzed. We report a comprehensive Pb-Sr-Nd-Hf isotopic and trace element concentration data set, combined with quantitative phase analysis by XRD Rietveld refinement, for a wide range of mafic to ultramafic rock reference materials analyzed at the Pacific Centre for Isotopic and Geochemical Research, University of British Columbia. The samples include a pyroxenite (NIM-P), five basalts (BHVO-2, BIR-1a, JB-3, BE-N, GSR-3), a diabase (W-2), a dolerite (DNC-1), a norite (NIM-N), and an anorthosite (AN-G); results from a leucogabbro (Stillwater) are also reported. Individual isotopic ratios determined by MC-ICP-MS and TIMS, and multielement analyses by HR-ICP-MS are reported with 4-12 complete analytical duplicates for each sample. The basaltic reference materials have coherent Sr and Nd isotopic ratios with external precision below 50 ppm (2SD) and below 100 ppm for Hf isotopes (except BIR-1a). For Pb isotopic reproducibility, several of the basalts (JB-3, BHVO-2) require acid leaching prior to dissolution. The plutonic reference materials also have coherent Sr and Nd isotopic ratios (<50 ppm), however, obtaining good reproducibility for Pb and Hf isotopic ratios is more challenging for NIM-P, NIM-N, and AN-G due to a variety of factors, including postcrystallization Pb mobility and the presence of accessory zircon. Collectively, these results form a comprehensive new database that can be used by the geochemical community for evaluating the radiogenic isotope and trace element compositions of volcanic and plutonic mafic-ultramafic rocks.

  11. Dual-energy cone-beam CT with a flat-panel detector: Effect of reconstruction algorithm on material classification

    Energy Technology Data Exchange (ETDEWEB)

    Zbijewski, W., E-mail: wzbijewski@jhu.edu; Gang, G. J.; Xu, J.; Wang, A. S.; Stayman, J. W. [Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205 (United States); Taguchi, K.; Carrino, J. A. [Russell H. Morgan Department of Radiology, Johns Hopkins University, Baltimore, Maryland 21205 (United States); Siewerdsen, J. H. [Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205 and Russell H. Morgan Department of Radiology, Johns Hopkins University, Baltimore, Maryland 21205 (United States)

    2014-02-15

    Purpose: Cone-beam CT (CBCT) with a flat-panel detector (FPD) is finding application in areas such as breast and musculoskeletal imaging, where dual-energy (DE) capabilities offer potential benefit. The authors investigate the accuracy of material classification in DE CBCT using filtered backprojection (FBP) and penalized likelihood (PL) reconstruction and optimize contrast-enhanced DE CBCT of the joints as a function of dose, material concentration, and detail size. Methods: Phantoms consisting of a 15 cm diameter water cylinder with solid calcium inserts (50–200 mg/ml, 3–28.4 mm diameter) and solid iodine inserts (2–10 mg/ml, 3–28.4 mm diameter), as well as a cadaveric knee with intra-articular injection of iodine were imaged on a CBCT bench with a Varian 4343 FPD. The low energy (LE) beam was 70 kVp (+0.2 mm Cu), and the high energy (HE) beam was 120 kVp (+0.2 mm Cu, +0.5 mm Ag). Total dose (LE+HE) was varied from 3.1 to 15.6 mGy with equal dose allocation. Image-based DE classification involved a nearest distance classifier in the space of LE versus HE attenuation values. Recognizing the differences in noise between LE and HE beams, the LE and HE data were differentially filtered (in FBP) or regularized (in PL). Both a quadratic (PLQ) and a total-variation penalty (PLTV) were investigated for PL. The performance of DE CBCT material discrimination was quantified in terms of voxelwise specificity, sensitivity, and accuracy. Results: Noise in the HE image was primarily responsible for classification errors within the contrast inserts, whereas noise in the LE image mainly influenced classification in the surrounding water. For inserts of diameter 28.4 mm, DE CBCT reconstructions were optimized to maximize the total combined accuracy across the range of calcium and iodine concentrations, yielding values of ∼88% for FBP and PLQ, and ∼95% for PLTV at 3.1 mGy total dose, increasing to ∼95% for FBP and PLQ, and ∼98% for PLTV at 15.6 mGy total dose. For a

  12. Comprehensive inter-laboratory calibration of reference materials for d18O versus VSMOW using various on-line high-temperature conversion techniques

    Science.gov (United States)

    Coplen, Tyler B.; Bohlke, Johnkarl F.; Mroczkowski, Stanley J.; Qi, Haiping; Brand, Willi A.; Aerts-Bijma, Anita T.; Gehre, Matthias; Geilmann, Heike; Groning, Manfred

    2009-01-01

    "Internationally distributed organic and inorganic oxygen isotopic reference materials have been calibrated by six laboratories carrying out more than 5300 measurements using a variety of high-temperature conversion techniques (HTC) in an evaluation sponsored by the International Union of Pure and Applied Chemistry (IUPAC). To aid in the calibration of these reference materials, which span more than 125‰, an artificially enriched reference water (d18O of +78.91‰) and two barium sulfates (one depleted and one enriched in 18O) were prepared and calibrated relative to VSMOW2 and SLAP reference waters. These materials were used to calibrate the other isotopic reference materials in this study, which yielded: Reference material d18O and estimated combined uncertainty

  13. Comprehensive inter-laboratory calibration of reference materials for δ18O versus VSMOW using various on-line high-temperature conversion techniques

    Science.gov (United States)

    Brand, Willi A.; Coplen, Tyler B.; Aerts-Bijma, Anita T.; Böhlke, J.K.; Gehre, Matthias; Geilmann, Heike; Groning, Manfred; Jansen, Henk G.; Meijer, Harro A. J.; Mroczkowski, Stanley J.; Qi, Haiping; Soergel, Karin; Stuart-Williams, Hilary; Weise, Stephan M.; Werner, Roland A.

    2009-01-01

    Internationally distributed organic and inorganic oxygen isotopic reference materials have been calibrated by six laboratories carrying out more than 5300 measurements using a variety of high-temperature conversion techniques (HTC)a in an evaluation sponsored by the International Union of Pure and Applied Chemistry (IUPAC). To aid in the calibration of these reference materials, which span more than 125‰, an artificially enriched reference water (δ18O of +78.91‰) and two barium sulfates (one depleted and one enriched in 18O) were prepared and calibrated relative to VSMOW2b and SLAP reference waters. These materials were used to calibrate the other isotopic reference materials in this study, which yielded: Reference materialδ18O and estimated combined uncertainty c IAEA-602 benzoic acid

  14. The Kjeldahl method as a primary reference procedure for total protein in certified reference materials used in clinical chemistry. II. Selection of direct Kjeldahl analysis and its preliminary performance parameters.

    Science.gov (United States)

    Vinklárková, Bára; Chromý, Vratislav; Šprongl, Luděk; Bittová, Miroslava; Rikanová, Milena; Ohnútková, Ivana; Žaludová, Lenka

    2015-01-01

    To select a Kjeldahl procedure suitable for the determination of total protein in reference materials used in laboratory medicine, we reviewed in our previous article Kjeldahl methods adopted by clinical chemistry and found an indirect two-step analysis by total Kjeldahl nitrogen corrected for its nonprotein nitrogen and a direct analysis made on isolated protein precipitates. In this article, we compare both procedures on various reference materials. An indirect Kjeldahl method gave falsely lower results than a direct analysis. Preliminary performance parameters qualify the direct Kjeldahl analysis as a suitable primary reference procedure for the certification of total protein in reference laboratories.

  15. Marine mammal blubber reference and control materials for use in the determination of halogenated organic compounds and fatty acids

    Energy Technology Data Exchange (ETDEWEB)

    Kucklick, John R.; Pugh, Rebecca S.; Becker, Paul R. [Hollings Marine Laboratory, National Institute of Standards and Technology (NIST), Charleston, SC (United States); Schantz, Michele M.; Porter, Barbara J.; Poster, Dianne L.; Leigh, Stefan; Wise, Stephen A. [NIST, Analytical Chemistry Division, Gaithersburg, MD (United States); Rowles, Teri K. [National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Silver Spring, MD (United States)

    2010-05-15

    The National Institute of Standards and Technology (NIST) has a diverse collection of control materials derived from marine mammal blubber, fat, and serum. Standard Reference Material (SRM) 1945 Organics in Whale Blubber was recertified for polychlorinated biphenyl (PCB) congeners, organochlorine pesticides, and polybrominated diphenyl ether (PBDE) congeners. SRM 1945 has also been assigned mass fraction values for compounds not frequently determined in marine samples including toxaphene congeners, coplanar PCBs, and methoxylated PBDE congeners which are natural products. NIST also has assigned mass fraction values, as a result of interlaboratory comparison exercises, for PCB congeners, organochlorine pesticides, PBDE congeners, and fatty acids in six homogenate materials produced from marine mammal blubber or serum. The materials are available from NIST upon request; however, the supply is very limited for some of the materials. The materials include those obtained from pilot whale blubber (Homogenates III and IV), Blainville's beaked whale blubber (Homogenate VII), polar bear fat (Homogenate VI), and California sea lion serum (Marine Mammal Control Material-1 Serum) and blubber (Homogenate V). (orig.)

  16. Standard practice for design, manufacture and material grouping classification of wire image quality indicators (IQI) used for radiology

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice covers the design, material grouping classification, and manufacture of wire image quality indicators (IQI) used to indicate the quality of radiologic images. 1.2 This practice is applicable to X-ray and gamma-ray radiology. 1.3 This practice covers the use of wire penetrameters as the controlling image quality indicator for the material thickness range from 6.4 to 152 mm (0.25 to 6.0 in.). 1.4 The values stated in inch-pound units are to be regarded as standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  17. The Development of Certified Substantial Reference Material for Radioactivity of Building Materials%放射性建材实物标准样品的研制

    Institute of Scientific and Technical Information of China (English)

    韩颖

    2012-01-01

    Certified Substantial RMs "Reference Material for Radioactivity of Stone", "Reference Material for Radioactivity of the Ceramic Products" and "Reference Material for Radioactivity of the Powder Ash Air- entrained Concrete" are used to calibrate γ spectrometers and examine the veracity of the measurement for the content of radionuclides 256Ra, 232Th and 40K in approximate host-material samples.They covers all the radionuclides needed to be tested in building materials. All the radionuclides have been in secular radioactive equilibrium.The fixed value of these three RMs were measured by 8 authoritative radioactivity testing institution. Their homogeneity and stability is good so as to provide to protection for people's safety and health.%有证实物标准样品“石材放射性标准样品”、“陶瓷产品的放射性标准样品”及“粉煤灰砌块的放射性标准样品”适用于γ谱仪校准和考核相近基质样品中所含放射性核素36Ra、232h和40K含量测定的准确性,覆盖了建材产品需要检验的所有核素,达到放射平衡。样品由8家权威放射性检测机构采用低本底多道γ能谱仪测量方法进行定值测量,均匀性和稳定性良好,以对人们的安全与健康提供保护。

  18. Factors Affecting the Supply of Strategic Raw Materials with Particular Reference to the Aerospace Manufacturing Industry

    Science.gov (United States)

    1984-04-01

    scale of production and technological-industrial problems, chromium, cobalt, hafnium , manganese, niobium, titanium, tungsten and vanadium are all...resources are likely to increase. While the raw materials specified (chromium, cobalt, hafnium , niobium, tantalum, manganese, molybdenum, titanium...are those based on aluminium , nickel, steel and titanium. In engine production nickel, steel and titanium are used respectively for the hot end

  19. Two new reference materials based on tobacco leaves: certification for over a dozen of toxic and essential elements.

    Science.gov (United States)

    Samczyński, Zbigniew; Dybczyński, Rajmund S; Polkowska-Motrenko, Halina; Chajduk, Ewelina; Pyszynska, Marta; Danko, Bożena; Czerska, Elżbieta; Kulisa, Krzysztof; Doner, Katarzyna; Kalbarczyk, Paweł

    2012-01-01

    The preparation, certification, and characterization of two new biological certified reference materials for inorganic trace analysis have been presented. They are based on two different varieties of tobacco leaves, namely, Oriental Basma Tobacco Leaves (INCT-OBTL-5), grown in Greece, and Polish Virginia Tobacco Leaves (INCT-PVTL-6), grown in Poland. Certification of the materials was based on the statistical evaluation of results obtained in a worldwide interlaboratory comparison, in which 87 laboratories from 18 countries participated, providing 2568 laboratory averages on nearly 80 elements. It was possible to establish the certified values of concentration for many elements in the new materials, that is, 37 in INCT-OBTL-5 and 36 in INCT-PVTL-6, including several toxic ones like As, Cd, Hg, Pb, and so forth. The share and the role of instrumental analytical techniques used in the process of certification of the new CRMs are discussed.

  20. Iron Disilicide as High-Temperature Reference Material for Traceable Measurements of Seebeck Coefficient Between 300 K and 800 K

    Science.gov (United States)

    Ziolkowski, Pawel; Stiewe, Christian; de Boor, Johannes; Druschke, Ines; Zabrocki, Knud; Edler, Frank; Haupt, Sebastian; König, Jan; Mueller, Eckhard

    2016-09-01

    Thermoelectric generators (TEGs) convert heat to electrical energy by means of the Seebeck effect. The Seebeck coefficient is a central thermoelectric material property, measuring the magnitude of the thermovoltage generated in response to a temperature difference across a thermoelectric material. Precise determination of the Seebeck coefficient provides the basis for reliable performance assessment in materials development in the field of thermoelectrics. For several reasons, measurement uncertainties of up to 14% can often be observed in interlaboratory comparisons of temperature-dependent Seebeck coefficient or in error analyses on currently employed instruments. This is still too high for an industrial benchmark and insufficient for many scientific investigations and technological developments. The TESt (thermoelectric standardization) project was launched in 2011, funded by the German Federal Ministry of Education and Research (BMBF), to reduce measurement uncertainties, engineer traceable and precise thermoelectric measurement techniques for materials and TEGs, and develop reference materials (RMs) for temperature-dependent determination of the Seebeck coefficient. We report herein the successful development and qualification of cobalt-doped β-iron disilicide (β-Fe0.95Co0.05Si2) as a RM for high-temperature thermoelectric metrology. A brief survey on technological processes for manufacturing and machining of samples is presented. Focus is placed on metrological qualification of the iron disilicide, results of an international round-robin test, and final certification as a reference material in accordance with ISO-Guide 35 and the "Guide to the expression of uncertainty in measurement" by the Physikalisch-Technische Bundesanstalt, the national metrology institute of Germany.

  1. Iron Disilicide as High-Temperature Reference Material for Traceable Measurements of Seebeck Coefficient Between 300 K and 800 K

    Science.gov (United States)

    Ziolkowski, Pawel; Stiewe, Christian; de Boor, Johannes; Druschke, Ines; Zabrocki, Knud; Edler, Frank; Haupt, Sebastian; König, Jan; Mueller, Eckhard

    2017-01-01

    Thermoelectric generators (TEGs) convert heat to electrical energy by means of the Seebeck effect. The Seebeck coefficient is a central thermoelectric material property, measuring the magnitude of the thermovoltage generated in response to a temperature difference across a thermoelectric material. Precise determination of the Seebeck coefficient provides the basis for reliable performance assessment in materials development in the field of thermoelectrics. For several reasons, measurement uncertainties of up to 14% can often be observed in interlaboratory comparisons of temperature-dependent Seebeck coefficient or in error analyses on currently employed instruments. This is still too high for an industrial benchmark and insufficient for many scientific investigations and technological developments. The TESt (thermoelectric standardization) project was launched in 2011, funded by the German Federal Ministry of Education and Research (BMBF), to reduce measurement uncertainties, engineer traceable and precise thermoelectric measurement techniques for materials and TEGs, and develop reference materials (RMs) for temperature-dependent determination of the Seebeck coefficient. We report herein the successful development and qualification of cobalt-doped β-iron disilicide ( β-Fe0.95Co0.05Si2) as a RM for high-temperature thermoelectric metrology. A brief survey on technological processes for manufacturing and machining of samples is presented. Focus is placed on metrological qualification of the iron disilicide, results of an international round-robin test, and final certification as a reference material in accordance with ISO-Guide 35 and the "Guide to the expression of uncertainty in measurement" by the Physikalisch-Technische Bundesanstalt, the national metrology institute of Germany.

  2. A Family of Reference Hugoniots for Two-phase Porous Materials

    Science.gov (United States)

    2015-06-01

    material, which are the adiabatic compression of the gaseous phase and the heat due to plastic work generated from the deformation of particles. The...heating mechanisms mentioned in the literature [7] are cracking, adiabatic shear banding, cumulative jetting, etc. In addition, the flow from the... compression and adiabatic expansion of condensed substances, [in Russian], Sarov, Russian Federal Nuclear Centre - VNIIEF, 2nd ed., 2006. 13. van Thiel M

  3. Principles of material choice with reference to the Green Star SA rating system

    CSIR Research Space (South Africa)

    Van Reenen, Coralie A

    2014-09-01

    Full Text Available tools address engineered wood products (only in Interior Pilot tool), paints, adhesives and sealants, and carpets and flooring. VOC limits are specified and the use of materials that boast low VOC emissions or are VOC free is encouraged... colourless chemical that is a gas at room temperature with a pungent odour. In a poorly ventilated area, the effects of formaldehyde gas on humans range from respiratory effects (eg. Asthma) to eye, nose and throat irritations, skin irritation and fatigue...

  4. NAVAIR Portable Source Initiative (NPSI) Standard for Material Properties Reference Database (MPRD) V2.2

    Science.gov (United States)

    2012-09-26

    Shrub  Forb  Vine  Graminoid  Cactus  Fern  Lichen  Bryophyte MPRD Material Library is conceptually organized as a conventional library...and text. This data is organized in a desert landform hierarchy. auth-FEIS FEIS Fire Effects Information System (USDA forest service). auth-MPRD...Lodgepole Pine: Pinus contorta var. murrayana (latin name, defined under authority FEIS ( Fire Effects Information System (USDA forest service

  5. Assessment of Materialism and Reference Group Influence on Preference for Western Branded Fabrics in Maiduguri, Borno State, Nigeria

    Directory of Open Access Journals (Sweden)

    Mohammed Abba

    2013-01-01

    Full Text Available This paper investigates how materialism and reference group influence may affect consumers’ preference for western branded fabrics. Data for the study was collected through questionnaire administered on a sample of 26 respondents. The respondents were selected using convenient sampling through snowball from a population of male and female professional workers aged 18 and above. Data collected from the primary source (questionnaire was analyzed using simple percentage. Findings revealed that materialism had no significant influence on their preferences for western branded fabrics. Reference groups, however, significantly influenced respondents’ decision to purchase Western branded fabrics. It was concluded that although some of the behaviors of the sampled group were quite materialistic, they were not enhanced by associations with Western branded fabrics and their related cultural values. Based on the findings, it was recommended that marketers of western brands in Borno state, particularly in the state capital can do well if they adopt a strategy of deliberately targeting and nurturing of their consumers’ reference groups, rather than attempt to position their products on the basis of inherent materialistic values.

  6. Feasibility of the development of reference materials for the detection of Ag nanoparticles in food: neat dispersions and spiked chicken meat

    NARCIS (Netherlands)

    Grombe, R.; Allmaier, G.; Charoud-Got, J.; Dudkiewicz, A.; Emteborg, H.; Hofmann, T.; Huusfeldt-Larsen, E.; Lehner, A.; Llinas, M.; Loeschner, K.; Molhave, K.; Peters, R.J.B.; Seghers, J.; Solans, C.; Kammer, van den F.; Wagner, S.; Weigel, S.; Linsinger, T.P.J.

    2015-01-01

    The feasibility of producing colloidal silver nanoparticle reference materials and silver nanoparticle spiked reference matrix materials was investigated. Two concentrations of PVP-coated silver nanoparticle dispersions were evaluated and used to spike chicken meat, with the aim of producing a set o

  7. Feasibility of the development of reference materials for the detection of Ag nanoparticles in food: neat dispersions and spiked chicken meat

    NARCIS (Netherlands)

    Grombe, R.; Allmaier, G.; Charoud-Got, J.; Dudkiewicz, A.; Emteborg, H.; Hofmann, T.; Huusfeldt-Larsen, E.; Lehner, A.; Llinas, M.; Loeschner, K.; Molhave, K.; Peters, R.J.B.; Seghers, J.; Solans, C.; Kammer, van den F.; Wagner, S.; Weigel, S.; Linsinger, T.P.J.

    2015-01-01

    The feasibility of producing colloidal silver nanoparticle reference materials and silver nanoparticle spiked reference matrix materials was investigated. Two concentrations of PVP-coated silver nanoparticle dispersions were evaluated and used to spike chicken meat, with the aim of producing a set

  8. Fundamental discrepancies in abortion estimates and abortion-related mortality: A reevaluation of recent studies in Mexico with special reference to the International Classification of Diseases

    Directory of Open Access Journals (Sweden)

    Koch E

    2012-12-01

    Full Text Available Elard Koch,1,2 Paula Aracena,1 Sebastián Gatica,1 Miguel Bravo,1 Alejandra Huerta-Zepeda,3 Byron C Calhoun41Institute of Molecular Epidemiology (MELISA, Center of Embryonic Medicine and Maternal Health, Faculty of Medicine, Universidad Católica de la Santísima Concepción, Concepción, Chile; 2Faculty of Medicine, University of Chile, Santiago, Chile; 3Universidad Popular Autónoma del Estado de Puebla UPAEP, Puebla, México; 4Department of Obstetrics and Gynecology, West Virginia University, Charleston, WV, USAAbstract: In countries where induced abortion is legally restricted, as in most of Latin America, evaluation of statistics related to induced abortions and abortion-related mortality is challenging. The present article reexamines recent reports estimating the number of induced abortions and abortion-related mortality in Mexico, with special reference to the International Classification of Diseases (ICD. We found significant overestimations of abortion figures in the Federal District of Mexico (up to 10-fold, where elective abortion has been legal since 2007. Significant overestimation of maternal and abortion-related mortality during the last 20 years in the entire Mexican country (up to 35% was also found. Such overestimations are most likely due to the use of incomplete in-hospital records as well as subjective opinion surveys regarding induced abortion figures, and due to the consideration of causes of death that are unrelated to induced abortion, including flawed denominators of live births. Contrary to previous publications, we found important progress in maternal health, reflected by the decrease in overall maternal mortality (30.6% from 1990 to 2010. The use of specific ICD codes revealed that the mortality ratio associated with induced abortion decreased 22.9% between 2002 and 2008 (from 1.48 to 1.14 deaths per 100,000 live births. Currently, approximately 98% of maternal deaths in Mexico are related to causes other than

  9. Correlation of some soil types of Kosovo from the old Yugoslavian Soil Classification (YSC) into World Reference Bases for soil resources (WRB)

    Science.gov (United States)

    Bresilla, Betim; Zogaj, Muhamet; Szegi, Tamas; Micheli, Erika; Bresilla, Kushtrim

    2013-04-01

    Kosovo is still using the old Yugoslavian Soil Classification system. Therefore, the aim of this research is to view the correlation between the old Yugoslavian Soil Classification (YSC) and World Reference Bases for soil resources (WRB). A total of 46 samples of genetic horizons were collected from 11 profiles, randomly from a soil map of Kosovo (1974). The samples belong to four different soil types classified according to WRB, which are spread in different location throughout the country. The physical and chemical properties such as structure and texture, pH, organic matter OM, calcium carbonate CaCO3, cation exchange capacity CEC, base saturation BS and electrical conductivity EC were analyzed by standard methods. The results showed that the structure of most of the profiles are blocky angulare and blocky subangulare while the first and fourth profile have prismatic structure below 40 cm and the eighth profile have no structure below 25 cm. The texture of most of the profiles is loamy, clay and clay loamy, whereas the nineth profile sandy loam texture. The pH in H2O mostly is weak acidic, basic and weak alkaline, therefore, is decreasing with depth while in profiles that have a certain amount of CaCO3 the pH is increasing. The profiles are rich in organic matter but the OM is decreasing linearly with depth except in third profile that organic matter is increasing below topsoil. The CaCO3 takes place in profile seven below 90cm, in profile eight throughout it and in profile eleven as well. The cation exchange capacity varies from the profiles with 4.53 cmol/kg the lowest value in profile nine until 51.3 cmol/kg the highest value in profile eighth. Base saturation is more than 95% in all the profiles. The electrical conductivity varies from 71 mS/cm up to 545 mS/cm. Based on a field experiment, we found that the existing soil map of Kosovo (1974) is not fully corresponding to the soil in the field, thus, 45.45% of the map corresponds to the field, while 54

  10. Using the International Classification of Functioning, Disability and Health (ICF) to Describe Children Referred to Special Care or Paediatric Dental Services

    Science.gov (United States)

    Faulks, Denise; Norderyd, Johanna; Molina, Gustavo; Macgiolla Phadraig, Caoimhin; Scagnet, Gabriela; Eschevins, Caroline; Hennequin, Martine

    2013-01-01

    Children in dentistry are traditionally described in terms of medical diagnosis and prevalence of oral disease. This approach gives little information regarding a child’s capacity to maintain oral health or regarding the social determinants of oral health. The biopsychosocial approach, embodied in the International Classification of Functioning, Disability and Health - Child and Youth version (ICF-CY) (WHO), provides a wider picture of a child’s real-life experience, but practical tools for the application of this model are lacking. This article describes the preliminary empirical study necessary for development of such a tool - an ICF-CY Core Set for Oral Health. An ICF-CY questionnaire was used to identify the medical, functional, social and environmental context of 218 children and adolescents referred to special care or paediatric dental services in France, Sweden, Argentina and Ireland (mean age 8 years ±3.6yrs). International Classification of Disease (ICD-10) diagnoses included disorders of the nervous system (26.1%), Down syndrome (22.0%), mental retardation (17.0%), autistic disorders (16.1%), and dental anxiety alone (11.0%). The most frequently impaired items in the ICF Body functions domain were ‘Intellectual functions’, ‘High-level cognitive functions’, and ‘Attention functions’. In the Activities and Participation domain, participation restriction was frequently reported for 25 items including ‘Handling stress’, ‘Caring for body parts’, ‘Looking after one’s health’ and ‘Speaking’. In the Environment domain, facilitating items included ‘Support of friends’, ‘Attitude of friends’ and ‘Support of immediate family’. One item was reported as an environmental barrier – ‘Societal attitudes’. The ICF-CY can be used to highlight common profiles of functioning, activities, participation and environment shared by children in relation to oral health, despite widely differing medical, social and geographical

  11. A mixture model with a reference-based automatic selection of components for disease classification from protein and/or gene expression levels

    Directory of Open Access Journals (Sweden)

    Kopriva Ivica

    2011-12-01

    Full Text Available Abstract Background Bioinformatics data analysis is often using linear mixture model representing samples as additive mixture of components. Properly constrained blind matrix factorization methods extract those components using mixture samples only. However, automatic selection of extracted components to be retained for classification analysis remains an open issue. Results The method proposed here is applied to well-studied protein and genomic datasets of ovarian, prostate and colon cancers to extract components for disease prediction. It achieves average sensitivities of: 96.2 (sd = 2.7%, 97.6% (sd = 2.8% and 90.8% (sd = 5.5% and average specificities of: 93.6% (sd = 4.1%, 99% (sd = 2.2% and 79.4% (sd = 9.8% in 100 independent two-fold cross-validations. Conclusions We propose an additive mixture model of a sample for feature extraction using, in principle, sparseness constrained factorization on a sample-by-sample basis. As opposed to that, existing methods factorize complete dataset simultaneously. The sample model is composed of a reference sample representing control and/or case (disease groups and a test sample. Each sample is decomposed into two or more components that are selected automatically (without using label information as control specific, case specific and not differentially expressed (neutral. The number of components is determined by cross-validation. Automatic assignment of features (m/z ratios or genes to particular component is based on thresholds estimated from each sample directly. Due to the locality of decomposition, the strength of the expression of each feature across the samples can vary. Yet, they will still be allocated to the related disease and/or control specific component. Since label information is not used in the selection process, case and control specific components can be used for classification. That is not the case with standard factorization methods. Moreover, the component selected by proposed method

  12. An insect-inspired bionic sensor for tactile localisation and material classification with state-dependent modulation

    Directory of Open Access Journals (Sweden)

    Luca ePatanè

    2012-08-01

    Full Text Available Insects carry a pair of antennae on their head: multimodal sensory organs that serve a wide range of sensory-guided behaviours. During locomotion, antennae are involved in near-range orientation, for example in detecting, localising, probing and negotiating obstacles.Here we present a bionic, active tactile sensing system inspired by insect antennae. It comprises an actuated elastic rod equipped with a terminal acceleration sensor. The measurement principle is based on the analysis of damped harmonic oscillations registered upon contact with an object. The dominant frequency of the oscillation is extracted to determine the distance of the contact point along the probe, and basal angular encoders allow tactile localisation in a polar coordinate system. Finally, the damping behaviour of the registered signal is exploited to determine the most likely material.The tactile sensor is tested in four approaches with increasing neural plausibility: First, we show that peak extraction from the Fourier spectrum is sufficient for tactile localisation with position errors below 1%. Also, the damping property of the extracted frequency is used for material classification. Second, we show that the Fourier spectrum can be analysed by an Artificial Neural Network which can be trained to decode contact distance and to classify contact materials. Thirdly, we show how efficiency can be improved by band-pass filtering the Fourier spectrum by application of non-negative matrix factorisation. This reduces the input dimension by 95% while reducing classification performance by 8% only. Finally, we replace the FFT by an array of spiking neurons with gradually differing resonance properties, such that their spike rate is a function of the input frequency. We show that this network can be applied to detect tactile contact events of a wheeled robot, and how detrimental effects of robot velocity on antennal dynamics can be suppressed by state-dependent modulation of the

  13. 29 CFR 779.355 - Classification of lumber and building materials sales.

    Science.gov (United States)

    2010-07-01

    ... LABOR STANDARDS ACT AS APPLIED TO RETAILERS OF GOODS OR SERVICES Exemptions for Certain Retail or... business rather than a function of a retail merchant; (2) Sales of lumber and building materials in...

  14. Reference intervals for thyreotropin and thyroid hormones for healthy adults based on the NOBIDA material and determined using a Modular E170

    DEFF Research Database (Denmark)

    Friis-Hansen, Lennart; Hilsted, Linda

    2008-01-01

    BACKGROUND: The aim of the present study was to establish Nordic reference intervals for thyreotropin (TSH) and the thyroid hormones in heparinized plasma. METHODS: We used 489 heparinized blood samples, collected in the morning, from the Nordic NOBIDA reference material, from healthy adults....... The number and distribution of the samples in the NOBIDA material makes it suitable for the determination of hormone Nordic reference intervals....

  15. Examples of reference material data needed for LBB analysis derived from WGCS-EC-DGXI studies

    Energy Technology Data Exchange (ETDEWEB)

    Petrequin, P.; Houssin, B.; Guinovart, J.

    1997-04-01

    Mechanical data collected through the sponsorship of the Activity Group 3 <<Materials>> of the Working Group Codes and Standards of DG XI European Commission are pointed out to illustrate their potential use for Leak Before Break analyses. Most of the tensile, fatigue, creep and fracture toughness data have been generated for stainless steels, mainly on modified type 316 L (N), selected for the Super Phoenix LMFBR. Trends for ongoing programs and future works on C-Mn and MnNiMo low alloy steels are provided.

  16. Effect of certified reference material 470 (CRM 470) on national quality assurance programs for serum proteins in Europe.

    Science.gov (United States)

    Johnson, A M; Whicher, J T

    2001-11-01

    The introduction of the international reference material for serum proteins, CRM 470, has resulted in significant reduction of the among-laboratory variance for most proteins assayed in European national quality assurance programs. In general, the CVs have decreased by 5 to 65%. However, both among- and within-manufacturer variances in many cases remain unacceptably high. In addition, concentration-dependent differences in variance and bias are present for some proteins. Although some variance will persist, reducing variance and bias to levels required for the institution of universal reference ranges will necessitate more accurate transfer of values to calibrants and controls and improved calibration curve fitting by manufacturers, as well as better quality control within laboratories.

  17. Determination of total fluorine in five coal reference materials by proton-induced gamma-ray emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Roelandts, I.; Robaye, G.; Delbrouck-Habaru, J.M.; Weber, G. [University of Liege, Sart (Belgium). Dept. of Geology, Petrology and Geochemistry

    1996-03-01

    The direct non-destructive proton-induced gamma-ray emission (PIGE) technique with a germanium detector was applied to the determination of total fluorine concentration in five coal reference materials (BCR 30, NIST 1632b, NIST 1635, SARM 20 and USGS CLB-1). Duplicate analyses were made from five randomly selected bottles of each coal. Individual data are presented and some problems (calibration, proton stopping power, effects of sample heating by the proton beam, background estimation) which were encountered during this study are discussed. Sensitivity and reproducibility of the determinations, and homogeneity of the coal samples with respect to fluorine contents by analysis of variance were investigated. The present data are also compared with the few published values for these reference samples, including other PIGE data. The use of synthetic standards and spiked samples in the present study suggested that the PIGE method was more accurate than other techniques.

  18. A new certified reference material for benzene measurement in air on a sorbent tube: development and proficiency testing.

    Science.gov (United States)

    Caurant, A; Lalère, B; Schbath, M-C; Stumpf, C; Sutour, C; Mace, T; Quisefit, J-P; Doussin, J-F; Vaslin-Reimann, S

    2010-11-01

    A certified matrix reference material (CRM) for the measurement of benzene in ambient air has been developed at Laboratoire National de Métrologie et d'Essais. The production of these CRMs was conducted using a gravimetric method fully traceable to the International System of Units. The CRMs were prepared by sampling an accurate mass of a gaseous primary reference material of benzene, using a high-precision laminar flowmeter and a mass flow controller, with a PerkinElmer sampler filled with Carbopack™ X sorbent. The relative standard deviations obtained for the preparation of a batch of 20 tubes loaded with 500 ng of benzene were below 0.2%. Each CRM is considered independent from the others and with its own certified value and an expanded uncertainty estimated to be within 0.5%, lower than the uncertainties of benzene CRMs already available worldwide. The stability of these materials was also established up to 12 months. These CRMs were implemented during proficiency testing, to evaluate the analytical performances of seven French laboratories involved in benzene air monitoring.

  19. 甲苯中苯标准物质的研制%Development of reference material of benzene in toluene

    Institute of Scientific and Technical Information of China (English)

    张苏敏; 张毅; 代妍; 何丘

    2012-01-01

    以甲苯和苯为原料,采用称量-容量法研制了浓度为5 mg/mL的甲苯中苯溶液标准物质.所研制的标准物质通过均匀性检验、稳定性检验和与GBW(E) 130101的比对,标准值的相对扩展不确定度为3%(k=2),有效期限为24 m.%A kind of reference material of benzene in toluene was prepared using benzene and toluene as raw materials by Gravimetric-Volume Method. The standard value of concentration is 5 mg/mL. The reference material passed the homogeneity inspection, stability examination and intercomparison test between it and GBW(E) 130101. The relative expanded uncertainty of the concentration standard value is 3% (A = 2). The validity period is 24 m.

  20. Accuracy of reported flash point values on material safety data sheets and the impact on product classification.

    Science.gov (United States)

    Radnoff, Diane

    2013-01-01

    Material Safety Data Sheets (MSDSs) are the foundation of worker right-to-know legislation for chemical hazards. Suppliers can use product test data to determine a product's classification. Alternatively, they may use evaluation and professional judgment based on test results for the product or a product, material, or substance with similar properties. While the criteria for classifying products under the new Globally Harmonized System of Classification and Labeling of Chemicals (GHS) are different, a similar process is followed. Neither the current Workplace Hazardous Materials Information System (WHMIS) nor GHS require suppliers to test their products to classify them. In this project 83 samples of products classified as flammable or combustible, representing a variety of industry sectors and product types, were collected. Flash points were measured and compared to the reported values on the MSDSs. The classifications of the products were then compared using the WHMIS and GHS criteria. The results of the study indicated that there were significant variations between the disclosed and measured flash point values. Overall, more than one-third of the products had flash points lower than that disclosed on the MSDS. In some cases, the measured values were more than 20°C lower than the disclosed values. This could potentially result in an underestimation regarding the flammability of the product so it is important for employers to understand the limitations in the information provided on MSDSs when developing safe work procedures and training programs in the workplace. Nearly one-fifth of the products were misclassified under the WHMIS system as combustible when the measured flash point indicated that they should be classified as flammable when laboratory measurement error was taken into account. While a similar number of products were misclassified using GHS criteria, the tendency appeared to be to "over-classify" (provide a hazard class that was more conservative

  1. MO-F-CAMPUS-I-03: Tissue Equivalent Material Phantom to Test and Optimize Coherent Scatter Imaging for Tumor Classification

    Energy Technology Data Exchange (ETDEWEB)

    Albanese, K; Morris, R; Lakshmanan, M; Greenberg, J; Kapadia, A [Duke University, Durham, NC (United States)

    2015-06-15

    Purpose: To accurately model different breast geometries using a tissue equivalent phantom, and to classify these tissues in a coherent x-ray scatter imaging system. Methods: A breast phantom has been designed to assess the capability of coded aperture coherent x-ray scatter imaging system to classify different types of breast tissue (adipose, fibroglandular, tumor). The tissue-equivalent phantom was modeled as a hollow plastic cylinder containing multiple cylindrical and spherical inserts that can be positioned, rearranged, or removed to model different breast geometries. Each enclosure can be filled with a tissue-equivalent material and excised human tumors. In this study, beef and lard, placed inside 2-mm diameter plastic Nalgene containers, were used as surrogates for fibroglandular and adipose tissue, respectively. The phantom was imaged at 125 kVp, 40 mA for 10 seconds each with a 1-mm pencil beam. The raw data were reconstructed using a model-based reconstruction algorithm and yielded the location and form factor, or momentum transfer (q) spectrum of the materials that were imaged. The measured material form factors were then compared to the ground truth measurements acquired by x-ray diffraction (XRD) imaging. Results: The tissue equivalent phantom was found to accurately model different types of breast tissue by qualitatively comparing our measured form factors to those of adipose and fibroglandular tissue from literature. Our imaging system has been able to define the location and composition of the various materials in the phantom. Conclusion: This work introduces a new tissue equivalent phantom for testing and optimization of our coherent scatter imaging system for material classification. In future studies, the phantom will enable the use of a variety of materials including excised human tissue specimens in evaluating and optimizing our imaging system using pencil- and fan-beam geometries. United States Department of Homeland Security Duke University

  2. 238U/235U determinations of some commonly used reference materials and U-bearing accessory minerals (Invited)

    Science.gov (United States)

    Condon, D.; Noble, S.; McLean, N.; Bowring, S. A.

    2009-12-01

    We have determined 238U/235U ratios for a suite of commonly used natural (CRM 112a, SRM 950a, HU-1) and synthetic (IRMM 184 and CRM U500) uranium reference materials in addition to several U-bearing accessory phases (zircon and monazite) by thermal ionisation mass-spectrometry (TIMS) using the IRMM 3636 233U-236U double spike to accurately correct for mass fractionation. The 238U/235U values for the natural uranium reference materials differ, by up to 0.1%, from the widely used ‘consensus’ value (137.88) with all having 238U/235U values less than 137.88. Similarly, initial 238U/235U data from zircon and monazite yield 238U/235U values that are lower than the ‘consensus’ value. The data obtained from U-bearing minerals is used to assess how the uncertainty in the 238U/235U ratio contributes to the systematic discordance observed in 238U/206Pb and 235U/207Pb dates (Mattinson, 2000; Schoene et al., 2006) which has traditionally been wholly attributed to error in the U decay constants. The 238U/235U determinations made on the synthetic reference materials yield results that are considerably more precise and accurate than the certified values (0.02% vs. 0.1% for CRM U500). The calibration of isotopic tracers used for U-daughter geochronology that are partially based upon these reference materials, and the resultant age determinations, will benefit from increased accuracy and precision. Mattinson, J.M., 2000. Revising the “gold standard”—the uranium decay constants of Jaffey et al., 1971. Eos Trans. AGU, Spring Meet. Suppl., Abstract V61A-02. Schoene B., Crowley J.L., Condon D.C., Schmitz M.D., Bowring S.A., 2006, Reassessing the uranium decay constants for geochronology using ID-TIMS U-Pb data. Geochimica et Cosmochimica Acta 70: 426-445

  3. Development of a new ferulic acid certified reference material for use in clinical chemistry and pharmaceutical analysis

    Directory of Open Access Journals (Sweden)

    Dezhi Yang

    2015-05-01

    Full Text Available This study compares the results of three certified methods, namely differential scanning calorimetry (DSC, the mass balance (MB method and coulometric titrimetry (CT, in the purity assessment of ferulic acid certified reference material (CRM. Purity and expanded uncertainty as determined by the three methods were respectively 99.81%, 0.16%; 99.79%, 0.16%; and 99.81%, 0.26% with, in all cases, a coverage factor (k of 2 (P=95%. The purity results are consistent indicating that the combination of DSC, the MB method and CT provides a confident assessment of the purity of suitable CRMs like ferulic acid.

  4. Fundamental discrepancies in abortion estimates and abortion-related mortality: A reevaluation of recent studies in Mexico with special reference to the International Classification of Diseases.

    Science.gov (United States)

    Koch, Elard; Aracena, Paula; Gatica, Sebastián; Bravo, Miguel; Huerta-Zepeda, Alejandra; Calhoun, Byron C

    2012-01-01

    In countries where induced abortion is legally restricted, as in most of Latin America, evaluation of statistics related to induced abortions and abortion-related mortality is challenging. The present article reexamines recent reports estimating the number of induced abortions and abortion-related mortality in Mexico, with special reference to the International Classification of Diseases (ICD). We found significant overestimations of abortion figures in the Federal District of Mexico (up to 10-fold), where elective abortion has been legal since 2007. Significant overestimation of maternal and abortion-related mortality during the last 20 years in the entire Mexican country (up to 35%) was also found. Such overestimations are most likely due to the use of incomplete in-hospital records as well as subjective opinion surveys regarding induced abortion figures, and due to the consideration of causes of death that are unrelated to induced abortion, including flawed denominators of live births. Contrary to previous publications, we found important progress in maternal health, reflected by the decrease in overall maternal mortality (30.6%) from 1990 to 2010. The use of specific ICD codes revealed that the mortality ratio associated with induced abortion decreased 22.9% between 2002 and 2008 (from 1.48 to 1.14 deaths per 100,000 live births). Currently, approximately 98% of maternal deaths in Mexico are related to causes other than induced abortion, such as hemorrhage, hypertension and eclampsia, indirect causes, and other pathological conditions. Therefore, only marginal or null effects would be expected from changes in the legal status of abortion on overall maternal mortality rates. Rather, maternal health in Mexico would greatly benefit from increasing access to emergency and specialized obstetric care. Finally, more reliable methodologies to assess abortion-related deaths are clearly required.

  5. Fundamental discrepancies in abortion estimates and abortion-related mortality: A reevaluation of recent studies in Mexico with special reference to the International Classification of Diseases

    Science.gov (United States)

    Koch, Elard; Aracena, Paula; Gatica, Sebastián; Bravo, Miguel; Huerta-Zepeda, Alejandra; Calhoun, Byron C

    2012-01-01

    In countries where induced abortion is legally restricted, as in most of Latin America, evaluation of statistics related to induced abortions and abortion-related mortality is challenging. The present article reexamines recent reports estimating the number of induced abortions and abortion-related mortality in Mexico, with special reference to the International Classification of Diseases (ICD). We found significant overestimations of abortion figures in the Federal District of Mexico (up to 10-fold), where elective abortion has been legal since 2007. Significant overestimation of maternal and abortion-related mortality during the last 20 years in the entire Mexican country (up to 35%) was also found. Such overestimations are most likely due to the use of incomplete in-hospital records as well as subjective opinion surveys regarding induced abortion figures, and due to the consideration of causes of death that are unrelated to induced abortion, including flawed denominators of live births. Contrary to previous publications, we found important progress in maternal health, reflected by the decrease in overall maternal mortality (30.6%) from 1990 to 2010. The use of specific ICD codes revealed that the mortality ratio associated with induced abortion decreased 22.9% between 2002 and 2008 (from 1.48 to 1.14 deaths per 100,000 live births). Currently, approximately 98% of maternal deaths in Mexico are related to causes other than induced abortion, such as hemorrhage, hypertension and eclampsia, indirect causes, and other pathological conditions. Therefore, only marginal or null effects would be expected from changes in the legal status of abortion on overall maternal mortality rates. Rather, maternal health in Mexico would greatly benefit from increasing access to emergency and specialized obstetric care. Finally, more reliable methodologies to assess abortion-related deaths are clearly required. PMID:23271925

  6. Childhood obesity classification systems and cardiometabolic risk factors: a comparison of the Italian, World Health Organization and International Obesity Task Force references.

    Science.gov (United States)

    Valerio, Giuliana; Balsamo, Antonio; Baroni, Marco Giorgio; Brufani, Claudia; Forziato, Claudia; Grugni, Graziano; Licenziati, Maria Rosaria; Maffeis, Claudio; Miraglia Del Giudice, Emanuele; Morandi, Anita; Pacifico, Lucia; Sartorio, Alessandro; Manco, Melania

    2017-02-04

    Body Mass Index Italian reference data are available for clinical and/or epidemiological use, but no study compared the ability of this system to classify overweight and obesity and detect subjects with clustered cardiometabolic risk factors with international standards. Therefore our aim was to assess 1) the agreement among the Italian Society for Pediatric Endocrinology and Diabetology (ISPED), the World Health Organisation (WHO) and the International Obesity Task Force (IOTF) Body Mass Index cut-offs in estimating overweight or obesity in children and adolescents; 2) the ability of each above-mentioned set of cut-points to detect subjects with cardiometabolic risk factors. Data of 6070 Italian subjects aged 5-17 years were collected. Prevalence of normal-weight, overweight and obesity was determined using three classification systems: ISPED, WHO and IOTF. High blood pressure, hypertriglyceridemia, low high density lipoprotein-cholesterol and impaired fasting glucose were considered as cardiometabolic risk factors. ISPED and IOTF classified more subjects as normal-weight or overweight and less subjects as obese as compared to WHO (p  0.900), while it differed for obesity definition, ranging from the highest agreement between ISPED and IOTF (k 0.875) to the lowest between ISPED and WHO (k 0.664). WHO had the highest sensitivity, while ISPED and IOTF systems had the highest specificity, in identifying obese subjects with clustered cardiometabolic risk factors. Analogous results were found in subjects stratified by gender or age. ISPED and IOTF systems performed similarly in assessing overweight and obesity, and were more specific in identifying obese children/adolescents with clustered cardiometabolic risk factors; on the contrary, the WHO system was more sensitive. Given the seriousness of the obesity epidemic, we wonder whether the WHO system should be preferable to the national standards for clinical practice and/or obesity screening.

  7. What can be expected from high-Z semiconductor detectors. [Assessment of promising semiconductor materials; 25 references

    Energy Technology Data Exchange (ETDEWEB)

    Armantrout, G.A.; Swierkowski, S.P.; Sherohman, J.W.; Lee, J.H.

    1976-11-17

    It has been hoped that high-Z semiconductors would offer efficient ..gamma..-ray detection at or near ambient temperatures with energy resolution significantly better than NaI (Tl) scintillators. For use at X-ray energies, this goal has been achieved with both HgI/sub 2/, CdTe, and GaAs detectors. However, at higher energies (approximately 660 keV) all current detectors have one or more significant deficiencies in terms of attainable volume, charge collection efficiency, and polarization effects. Starting with first principles, all potential compounds which can be formed by the binary combination of elements from the periodic chart were considered as possible detector materials. A rank-ordered listing of the most promising materials for further development is given as well as an assessment of the prospects for future success. 25 references.

  8. Selective arsenic speciation analysis of human urine reference materials using gradient elution ion-exchange HPLC-ICP-MS

    DEFF Research Database (Denmark)

    Sloth, Jens Jørgen; Larsen, Erik Huusfeldt; Julshamn, K.

    2004-01-01

    Arsenic speciation analysis was performed in two human urine certified reference materials (NIES No. 18 and NIST SRM2670a) and three human urine control materials (Seronorm, Medisafe and Lyphocheck). The samples were diluted 1 + 3 prior to analysis by gradient elution anion or cation exchange high-performance...... liquid chromatography ( HPLC) coupled with inductively coupled plasma mass spectrometry (ICP-MS). Nine arsenic species, including arsenic acid, arsenous acid, monomethylarsonic acid, dimethylarsinic acid, arsenobetaine, trimethylarsine oxide, dimethylarsinoylacetic acid, trimethylarsoniopropionate...... and dimethylarsinoylethanol, were determined in the urines. Additionally, several unknown arsenicals were detected. This is the first time that dimethylarsinoylacetic acid and trimethylarsoniopropionate have been reported in human urine. The sums of the species concentrations determined by the chromatographic approaches were...

  9. Size Classification of Chopped Carbon Fibers in the Composite Materials Manufacturing

    OpenAIRE

    А.S. Dovbysh; А.F. Budnik; N.І. Andriienko

    2010-01-01

    Information synthesis of the learning decision support system for automation of the chopped carbon fibers size control used for the matrix filling within the manufacturing of composite materials based on polytetrafluoroethylene is considered. To improve the reliability of recognition learning algorithm with the optimization of the precision control is proposed.

  10. Size Classification of Chopped Carbon Fibers in the Composite Materials Manufacturing

    Directory of Open Access Journals (Sweden)

    А.S. Dovbysh

    2010-01-01

    Full Text Available Information synthesis of the learning decision support system for automation of the chopped carbon fibers size control used for the matrix filling within the manufacturing of composite materials based on polytetrafluoroethylene is considered. To improve the reliability of recognition learning algorithm with the optimization of the precision control is proposed.

  11. Introducing Students to Rheological Classification of Foods, Cosmetics, and Pharmaceutical Excipients Using Common Viscous Materials

    Science.gov (United States)

    Faustino, Ce´lia; Bettencourt, Ana F.; Alfaia, Anto´nio; Pinheiro, Lídia

    2015-01-01

    Rheological measurements are very important tools for the characterization of the flow and deformation of a material, as well as for optimization of the rheological parameters. The application and acceptance of pharmaceutical formulations, cosmetics, and foodstuffs depends upon their rheological characteristics, such as texture, consistency, or…

  12. Introducing Students to Rheological Classification of Foods, Cosmetics, and Pharmaceutical Excipients Using Common Viscous Materials

    Science.gov (United States)

    Faustino, Ce´lia; Bettencourt, Ana F.; Alfaia, Anto´nio; Pinheiro, Lídia

    2015-01-01

    Rheological measurements are very important tools for the characterization of the flow and deformation of a material, as well as for optimization of the rheological parameters. The application and acceptance of pharmaceutical formulations, cosmetics, and foodstuffs depends upon their rheological characteristics, such as texture, consistency, or…

  13. Method development in quantitative NMR towards metrologically traceable organic certified reference materials used as (31)P qNMR standards.

    Science.gov (United States)

    Weber, Michael; Hellriegel, Christine; Rueck, Alexander; Wuethrich, Juerg; Jenks, Peter; Obkircher, Markus

    2015-04-01

    Quantitative nuclear magnetic resonance (qNMR) spectroscopy is employed by an increasing number of analytical and industrial laboratories for the assignment of content and quantitative determination of impurities. Within the last few years, it was demonstrated that (1)H qNMR can be performed with high accuracy leading to measurement uncertainties below 1 % relative. It was even demonstrated that the combination of (1)H qNMR with metrological weighing can lead to measurement uncertainties below 0.1 % when highly pure substances are used. Although qNMR reference standards are already available as certified reference materials (CRM) providing traceability on the basis of (1)H qNMR experiments, there is an increasing demand for purity assays on phosphorylated organic compounds and metabolites requiring CRM for quantification by (31)P qNMR. Unfortunately, the number of available primary phosphorus standards is limited to a few inorganic CRM which only can be used for the analysis of water-soluble analytes but fail when organic solvents must be employed. This paper presents the concept of value assignment by (31)P qNMR measurements for the development of CRM and describes different approaches to establish traceability to primary Standard Reference Material from the National Institute of Standards and Technology (NIST SRM). Phosphonoacetic acid is analyzed as a water-soluble CRM candidate, whereas triphenyl phosphate is a good candidate for the use as qNMR reference material in organic solvents. These substances contain both nuclei, (1)H and (31)P, and the concept is to show that it is possible to indirectly quantify a potential phosphorus standard via its protons using (1)H qNMR. The same standard with its assigned purity can then be used for the quantification of an analyte via its phosphorus using (31)P qNMR. For the validation of the concept, triphenyl phosphate and phosphonoacetic acid have been used as (31)P qNMR standards to determine the purity of the analyte

  14. Development of High-purity Certified Reference Materials for 17 Proteinogenic Amino Acids by Traceable Titration Methods.

    Science.gov (United States)

    Kato, Megumi; Yamazaki, Taichi; Kato, Hisashi; Eyama, Sakae; Goto, Mari; Yoshioka, Mariko; Takatsu, Akiko

    2015-01-01

    To ensure the reliability of amino acid analyses, the National Metrology Institute of Japan of the National Institute of Advanced Industrial Science and Technology (NMIJ/AIST) has developed high-purity certified reference materials (CRMs) for 17 proteinogenic amino acids. These CRMs are intended for use as primary reference materials to enable the traceable quantification of amino acids. The purity of the present CRMs was determined based on two traceable methods: nonaqueous acidimetric titration and nitrogen determination by the Kjeldahl method. Since neither method could distinguish compounds with similar structures, such as amino acid-related impurities, impurities were thoroughly quantified by combining several HPLC methods, and subtracted from the obtained purity of each method. The property value of each amino acid was calculated as a weighted mean of the corrected purities by the two methods. The uncertainty of the property value was obtained by combining measurement uncertainties of the two methods, a difference between the two methods, the uncertainty from the contribution of impurities, and the uncertainty derived from inhomogeneity. The uncertainty derived from instability was considered to be negligible based on stability monitoring of some CRMs. The certified value of each amino acid, property value with uncertainty, was given for both with or without enantiomeric separation.

  15. Development of an In-Situ Radiological Classification Technique for Material from CERN's Accelerator Facilities

    CERN Document Server

    AUTHOR|(CDS)2081300; Froeschl, Robert; Forkel-Wirth, Doris

    CERN, the European Organization for Nuclear Research, operates high energy accelerators for particle physics research. Because of beam losses and subsequent particle interactions, radioactivity can be induced in certain accelerator components. Material and waste taken out of the accelerators facilities as a result of maintenance repair and upgrade actions as well as in case of decommissioning needs to be radiologically classied for future handling. Depending on the level of residual activity, some of these components are candidates for clearance from regulatory control in Switzerland. The Swiss radiation protection ordinance sets as criteria for clearance of material and waste from regulatory control the compliance with radionuclide specic limits for surface contamination and for specic activity as well as an ambient dose equivalent rate criterion. For objects with a mass below 1 kg a radionuclide specic clearance limit for total activity has to be respected. This work is focused on the specic activity criter...

  16. Recommended Hazard Classification Procedures for In-Process Propellant and Explosive Material

    Science.gov (United States)

    1980-09-01

    Test Impingement Test Rubbing Friction Test Local Thermal Test Regional Thermal Test Standard Test for Hazard Detection of Chemicals...a-9 Heater winding 33 a-10 Cover plates and heater terminals 34 a-11 Local thermal test , sample data sheet 35 a-11.1 Typical DTA - DSC curve with...mm LOCAL THERMAL TEST Purpose Inprocess explosive and propellant materials may be susceptible to initiation from localized hot spots from such

  17. Prediction and classification of the degradation state of plastic materials used in modern and contemporary art

    Science.gov (United States)

    Manfredi, M.; Barberis, E.; Marengo, E.

    2017-01-01

    Today, artworks partially or completely made of plastic materials can be found in almost all international museums and collections. The deterioration of these objects is now becoming evident mainly because these synthetic materials are not designed for a long life and the characterization of their state of conservation can help curators and conservators. In this research we investigated the applicability of a portable attenuated total reflection (ATR) infrared spectrometer for the non-invasive characterization and for monitoring the degradation of plastics used in modern and contemporary art. Several polypropylene and polycarbonate samples were artificially aged in solar box, simulating about 200 years of museum light exposure, and they were monitored with the portable ATR, creating an infrared library of the conservation state of plastics. Through the use of chemometric techniques like principal component analysis-linear discriminant analysis and partial least square—discriminant analysis, we built a robust degradation model of each material that can be used to predict and classify the degradation state of artworks and to identify the priority of intervention in the museum collections. Portable ATR coupled to multivariate statistics can be employed for taking care of plastic artworks as it is non-invasive, the analysis is very fast and it can be performed directly in situ.

  18. Evaluation of new geological reference materials for uranium-series measurements: Chinese Geological Standard Glasses (CGSG) and macusanite obsidian.

    Science.gov (United States)

    Denton, J S; Murrell, M T; Goldstein, S J; Nunn, A J; Amato, R S; Hinrichs, K A

    2013-10-15

    Recent advances in high-resolution, rapid, in situ microanalytical techniques present numerous opportunities for the analytical community, provided accurately characterized reference materials are available. Here, we present multicollector thermal ionization mass spectrometry (MC-TIMS) and multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) uranium and thorium concentration and isotopic data obtained by isotope dilution for a suite of newly available Chinese Geological Standard Glasses (CGSG) designed for microanalysis. These glasses exhibit a range of compositions including basalt, syenite, andesite, and a soil. Uranium concentrations for these glasses range from ∼2 to 14 μg g(-1), Th/U weight ratios range from ∼4 to 6, (234)U/(238)U activity ratios range from 0.93 to 1.02, and (230)Th/(238)U activity ratios range from 0.98 to 1.12. Uranium and thorium concentration and isotopic data are also presented for a rhyolitic obsidian from Macusani, SE Peru (macusanite). This glass can also be used as a rhyolitic reference material, has a very low Th/U weight ratio (around 0.077), and is approximately in (238)U-(234)U-(230)Th secular equilibrium. The U-Th concentration data agree with but are significantly more precise than those previously measured. U-Th concentration and isotopic data agree within estimated errors for the two measurement techniques, providing validation of the two methods. The large (238)U-(234)U-(230)Th disequilibria for some of the glasses, along with the wide range in their chemical compositions and Th/U ratios should provide useful reference points for the U-series analytical community.

  19. Resolving Radiological Waste Classification and Release Issues Using Material Process Information and Simple Measurements and Models

    Energy Technology Data Exchange (ETDEWEB)

    Hochel, R.C. [Westinghouse Savannah River Company, AIKEN, SC (United States)

    1997-11-01

    This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by United States Government or any agency thereof. The views and opinions of the author expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

  20. Determination of tungsten in geochemical reference material basalt Columbia River 2 by radiochemical neutron activation analysis and inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, Samuel S.; Beck, Chelsie L.; Bowen, James M.; Eggemeyer, Tere A.; Hines, Corey C.; Liezers, Martin; Metz, Lori A.; Morley, Shannon M.; Restis, Kaitlyn R.; Snow, Mathew; Wall, Donald E.; Clark, Sue B.; Seiner, Brienne N.

    2017-01-02

    Environmental tungsten (W) analyses are inhibited by a lack of reference materials and practical methods to remove isobaric and radiometric interferences. We present a method that evaluates the potential use of commercially available sediment, Basalt Columbia River-2 (BCR-2), as a reference material using neutron activation analysis (NAA) and mass spectrometry. Tungsten concentrations using both methods are in statistical agreement at the 95% confidence interval (92 ± 4 ng/g for NAA and 100 ±7 ng/g for mass spectrometry) with recoveries greater than 95%. These results indicate that BCR-2 may be suitable as a reference material for future studies.

  1. 烟草分析用氯溶液标准物质%Chlorine Solution Reference Material for Tobacco Analysis

    Institute of Scientific and Technical Information of China (English)

    蒋锦锋; 马明; 李栋; 李青常; 范黎

    2011-01-01

    In order to ensure the accuracy and traceability of the test results of chlorine content in tobacco by continuous flow method, the sodium chloride of primary reference material was used as the raw material of solution reference material (SRM). The SRM was prepared via weighing, dissolving, repacking and heat sealing and went through homogeneity and stability test. The mass concentration of the SRM was 0.1001 mg/mL valued by gravimetric method. The main factors influencing the uncertainty of the SRM, including mass, purity, volume, homogeneity and stability, were also analyzed, its uncertainty was of 0.0005 mg/mL.%为了保证连续流动法测定烟草中氯结果的准确性和可溯源性,选择一级标准物质氯化钠为原料,经定量称取和定体积溶解,安瓿瓶分装和热封,研制出氯溶液标准物质.该标准物质经均匀性、稳定性检验,并用重量法定值,其质量浓度为0.1001 mg/mL.对影响该标准物质不确定度的质量、纯度、体积、均匀性、稳定性等因素进行了分析,其不确定度为0.0005 mg/mL.

  2. Nano-sized aerosol classification, collection and analysis--method development using dental composite materials.

    Science.gov (United States)

    Bogdan, Axel; Buckett, Mary I; Japuntich, Daniel A

    2014-01-01

    This article presents a methodical approach for generating, collecting, and analyzing nano-size (1-100 nm) aerosol from abraded dental composite materials. Existing aerosol sampling instruments were combined with a custom-made sampling chamber to create and sample a fresh, steady-state aerosol size distribution before significant Brownian coagulation. Morphological, size, and compositional information was obtained by Transmission Electron Microscopy (TEM). To create samples sizes suitable for TEM analysis, aerosol concentrations in the test chamber had to be much higher than one would typically expect in a dental office, and therefore, these results do not represent patient or dental personnel exposures. Results show that nano-size aerosol was produced by the dental drill alone, with and without cooling water drip, prior to abrasion of dental composite. During abrasion, aerosol generation seemed independent of the percent filler load of the restorative material and the operator who generated the test aerosol. TEM investigation showed that "chunks" of filler and resin were generated in the nano-size range; however, free nano-size filler particles were not observed. The majority of observed particles consisted of oil droplets, ash, and graphitic structures.

  3. Semi-Supervised Bayesian Classification of Materials with Impact-Echo Signals

    Directory of Open Access Journals (Sweden)

    Jorge Igual

    2015-05-01

    Full Text Available The detection and identification of internal defects in a material require the use of some technology that translates the hidden interior damages into observable signals with different signature-defect correspondences. We apply impact-echo techniques for this purpose. The materials are classified according to their defective status (homogeneous, one defect or multiple defects and kind of defect (hole or crack, passing through or not. Every specimen is impacted by a hammer, and the spectrum of the propagated wave is recorded. This spectrum is the input data to a Bayesian classifier that is based on the modeling of the conditional probabilities with a mixture of Gaussians. The parameters of the Gaussian mixtures and the class probabilities are estimated using an extended expectation-maximization algorithm. The advantage of our proposal is that it is flexible, since it obtains good results for a wide range of models even under little supervision; e.g., it obtains a harmonic average of precision and recall value of 92.38% given only a 10% supervision ratio. We test the method with real specimens made of aluminum alloy. The results show that the algorithm works very well. This technique could be applied in many industrial problems, such as the optimization of the marble cutting process.

  4. Semi-supervised Bayesian classification of materials with impact-echo signals.

    Science.gov (United States)

    Igual, Jorge; Salazar, Addisson; Safont, Gonzalo; Vergara, Luis

    2015-05-19

    The detection and identification of internal defects in a material require the use of some technology that translates the hidden interior damages into observable signals with different signature-defect correspondences. We apply impact-echo techniques for this purpose. The materials are classified according to their defective status (homogeneous, one defect or multiple defects) and kind of defect (hole or crack, passing through or not). Every specimen is impacted by a hammer, and the spectrum of the propagated wave is recorded. This spectrum is the input data to a Bayesian classifier that is based on the modeling of the conditional probabilities with a mixture of Gaussians. The parameters of the Gaussian mixtures and the class probabilities are estimated using an extended expectation-maximization algorithm. The advantage of our proposal is that it is flexible, since it obtains good results for a wide range of models even under little supervision; e.g., it obtains a harmonic average of precision and recall value of 92.38% given only a 10% supervision ratio. We test the method with real specimens made of aluminum alloy. The results show that the algorithm works very well. This technique could be applied in many industrial problems, such as the optimization of the marble cutting process.

  5. Certified reference material for radionuclides in fish flesh sample IAEA-414 (mixed fish from the Irish Sea and North Sea)

    Energy Technology Data Exchange (ETDEWEB)

    Pham, M.K. [International Atomic Energy Agency (IAEA), Marine Environment Laboratory (MEL), MC 98000 (Monaco)]. E-mail: m.pham@iaea.org; Sanchez-Cabeza, J.A.; Povinec, P.P.; Gastaud, J.; La Rosa, J.; Lee, S.-H.; Liong Wee Kwong, L.; Oregioni, B.; Wyse, E. [International Atomic Energy Agency (IAEA), Marine Environment Laboratory (MEL), MC 98000 (Monaco); Arnold, D. [Physikalisch-Technische Bundesanstalt, Braunschweig, 38116 Germany (Germany); Benmansour, M. [Centre National de l' Energie, des Sciences et des Techniques Nucleaires (CNESTEN), B.P. 1382, R.P.10001, Rabat (Morocco); Bojanowski, R. [Institute of Oceanology, Polish Academy of Sciences, PL-81-712 Sopot (Poland); Carvalho, F.P. [Instituto Tecnologico e Nuclear, Departamento de Proteccao Radiologica e Seguranca Nuclear, P-2685-953 Sacavem (Portugal); Kim, C.K. [Department of Radiological Environmental Assessment, Korea Institute of Nuclear Safety, Yo-song, Taejon 305-600, Korea (Korea); Esposito, M. [Laboratorio di Ingegneria Nucleare, Universita di Bologna, 40136 Bologna (Italy); Gasco, C.L. [CIEMAT-DIAE, Radioecologia del Medio Acuatico, 28040 Madrid (Spain); Ham, G.J. [National Radiological Protection Board, Chilton, Didcot, Oxon, OX11 0RA (United Kingdom); Hegde, A.G. [Environmental Survey Laboratory, Bhabha Atomic Research Center, Tarapur Atomic Power Station, Maharashtra 401 504 (India); Holm, E. [Department of Medical Radiation Physics, Lund University Hospital, 22185 Lund (Sweden); Jaskierowicz, D. [Lab. d' Analyses de Surveillance et d' Expertise de la Marine, Base Navale de Cherbourg, 50115 Cherbourg (France); Kanisch, G. [Federal Research Centre for Fisheries, Institute of Fisheries Ecology, 20539 Hamburg (Germany); Llaurado, M. [Lab. de Radiologia Ambiental, Dept. de Quimica Analitica, Facultat de Quimica, Universitat de Barcelona, 08028 Barcelona (Spain); Le Petit, G. [Commissariat a l' Energie Atomique, DASE/SRCE, 91680 Bruyeres-le-Chatel (France); Maruo, Y. [and others

    2006-10-15

    A certified reference material (CRM) for radionuclides in fish sample IAEA-414 (mixed fish from the Irish Sea and North Seas) is described and the results of the certification process are presented. Nine radionuclides ({sup 4}K, {sup 137}Cs, {sup 232}Th, {sup 234}U, {sup 235}U, {sup 238}U, {sup 238}Pu, {sup 239+24}Pu and {sup 241}Am) were certified for this material. Information on massic activities with 95% confidence intervals is given for six other radionuclides ({sup 9}Sr, {sup 21}Pb({sup 21}Po), {sup 226}Ra, {sup 239}Pu, {sup 24}Pu {sup 241}Pu). Less frequently reported radionuclides ({sup 99}Tc, {sup 129}I, {sup 228}Th, {sup 23}Th and {sup 237}Np) and information on some activity and mass ratios are also included. The CRM can be used for quality assurance/quality control of the analysis of radionuclides in fish sample, for the development and validation of analytical methods and for training purposes. The material is available from IAEA, Vienna, in 100 g units.

  6. An Overview of Pickering Emulsions: Solid-Particle Materials, Classification, Morphology, and Applications

    Directory of Open Access Journals (Sweden)

    Yunqi Yang

    2017-05-01

    Full Text Available Pickering emulsion, a kind of emulsion stabilized only by solid particles locating at oil–water interface, has been discovered a century ago, while being extensively studied in recent decades. Substituting solid particles for traditional surfactants, Pickering emulsions are more stable against coalescence and can obtain many useful properties. Besides, they are more biocompatible when solid particles employed are relatively safe in vivo. Pickering emulsions can be applied in a wide range of fields, such as biomedicine, food, fine chemical synthesis, cosmetics, and so on, by properly tuning types and properties of solid emulsifiers. In this article, we give an overview of Pickering emulsions, focusing on some kinds of solid particles commonly serving as emulsifiers, three main types of products from Pickering emulsions, morphology of solid particles and as-prepared materials, as well as applications in different fields.

  7. Holocaust in the Classroom: Books--Variety and Convenience [and] Deaf Students, Reference Materials, and the Holocaust.

    Science.gov (United States)

    Schleper, David R.

    1999-01-01

    Suggested books and reference sources for deaf students studying the holocaust include picture books, beginning chapter books, chapter books, poems and comics, reference books, deaf-related Web sites, general holocaust Web sites, and deaf-related printed references. (DB)

  8. Certified reference materials for radionuclides in Bikini Atoll sediment (IAEA-410) and Pacific Ocean sediment (IAEA-412).

    Science.gov (United States)

    Pham, M K; van Beek, P; Carvalho, F P; Chamizo, E; Degering, D; Engeler, C; Gascó, C; Gurriaran, R; Hanley, O; Harms, A V; Herrmann, J; Hult, M; Ikeuchi, Y; Ilchmann, C; Kanisch, G; Kis-Benedek, G; Kloster, M; Laubenstein, M; Llaurado, M; Mas, J L; Nakano, M; Nielsen, S P; Osvath, I; Povinec, P P; Rieth, U; Schikowski, J; Smedley, P A; Suplinska, M; Sýkora, I; Tarjan, S; Varga, B; Vasileva, E; Zalewska, T; Zhou, W

    2016-03-01

    The preparation and characterization of certified reference materials (CRMs) for radionuclide content in sediments collected offshore of Bikini Atoll (IAEA-410) and in the open northwest Pacific Ocean (IAEA-412) are described and the results of the certification process are presented. The certified radionuclides include: (40)K, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (232)Th, (234)U, (238)U, (239)Pu, (239+240)Pu and (241)Am for IAEA-410 and (40)K, (137)Cs, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (232)Th, (235)U, (238)U, (239)Pu, (240)Pu and (239+240)Pu for IAEA-412. The CRMs can be used for quality assurance and quality control purposes in the analysis of radionuclides in sediments, for development and validation of analytical methods and for staff training. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Evaluation of cyanocobalamin in multivitamin tablets and their Standard Reference Material 3280 by HPLC with visible detection.

    Science.gov (United States)

    Matsumoto, Teruki; Takebayashi, Jun; Ishimi, Yoshiko; Ozawa, Chihiro; Sano, Akira; Hirota, Takashi; Endoh, Kaori

    2012-01-01

    As a part of the development of an alternative to microbiological assay for vitamin B12, we performed a quantitative analysis of cyanocobalamin (CN-cbl) in a National Institute of Standards and Technology Standard Reference Material (SRM 3280) by HPLC. Using this method, the observed value (4.64 microg/g) of CN-cbl in SRM 3280 was found to be in good agreement with the certified value (4.80 microg/g). The accuracy was over 95%, with a corresponding measurement precision value of 5%. To evaluate the applicability of the method on commercial multivitamin tablets, the method was applied to a variety of these samples. The present method has a good accuracy and precision to evaluate CN-cbl with respect to all of the examined tablets.

  10. Multi-product newsvendor problem with hybrid demand and its applications to ordering pharmaceutical reference standard materials

    Science.gov (United States)

    Wang, Dan; Qin, Zhongfeng

    2016-04-01

    Uncertainty is inherent in the newsvendor problem. Most of the existing literature is devoted to characterizing the uncertainty either by randomness or by fuzziness. However, in many cases, randomness and fuzziness simultaneously appear in the same problem. Motivated by this observation, we investigate the multi-product newsvendor problem by considering the demands as hybrid variables which are proposed to describe quantities with double uncertainties. According to the expected value criterion, we formulate an expected profit maximization model and convert it to a deterministic form when the chance distributions are given. We discuss two special cases of hybrid variable demands and give their chance distributions. Then we design hybrid simulation to estimate the chance distribution and use genetic algorithm to solve the proposed models. Finally, we proceed to present numerical examples of purchasing pharmaceutical reference standard materials to illustrate the applicability of our methodology and the effectiveness of genetic algorithm.

  11. Desenvolvimento de material de referência para microbiologia de alimentos contendo estafilococos coagulase positiva em matriz queijo Development of reference material for the microbiology of foods containing coagulase-positive Staphylococcus in a cheese matrix

    Directory of Open Access Journals (Sweden)

    Marcelo Luiz Lima Brandão

    2013-03-01

    Full Text Available O uso de materiais de referência (MR é uma das principais ferramentas utilizadas para garantia e controle da qualidade de laboratórios de microbiologia de alimentos. No Brasil, a RDC n.º 12/01 da Anvisa prevê como um dos parâmetros para a avaliação da qualidade de queijos a enumeração de estafilococos coagulase positiva (ECP. O grande desafio na produção de MR destinados a ensaios microbiológicos é a instabilidade natural dos micro-organismos, o que dificulta o desenvolvimento e a manutenção desses MR. O objetivo deste estudo foi produzir um MR quantitativo destinado ao ensaio de enumeração de ECP em matriz queijo. Uma amostra de queijo ultrafiltrado com contagem de ECP The use of reference materials (RM is one of the principal tools used for assurance and quality control in food microbiology laboratories. In Brazil, Anvisa RDC nº 12/01 specifies the enumeration of coagulase-positive staphylococcus (CPS as one of the parameters for evaluating cheese quality. The main challenge in the production of RM destined for microbiological assays is the natural instability of the microorganisms, which makes it difficult to develop and maintain them. This study aimed to produce a quantitative RM for use in enumeration assays of CPS in cheese matrixes. A sample of an ultra-filtered cheese with a CPS count of <10 CFU/g and a total nº of viable aerobes of 1.2 × 10³ CFU/g was used as the matrix to produce the RM. The matrix was distributed in flasks, contaminated with specific concentrations of the target bacteria and submitted to freeze-drying. Sucrose was used as the cryo-protector. The RM produced was considered homogeneous and stable at < -70ºC during the entire study period (10 months. The material was shown to be stable at 4, 25, 30 and 35 ºC for 4 days, although the results indicated a decrease in cell concentration at 35 ºC. At -20 ºC the RM was stable for 48 days. It was concluded that the material showed all the necessary

  12. Establishment of a standard reference material (SRM) herbal DNA barcode library of Vitex negundo L. (lagundi) for quality control measures.

    Science.gov (United States)

    Olivar, Jay Edneil C; Alaba, Joanner Paulus Erik P; Atienza, Jose Francisco M; Tan, Jerick Jeffrey S; Umali, Maximo T; Alejandro, Grecebio Jonathan D

    2016-05-01

    The majority of the population in the Philippines relies on herbal products as their primary source for their healthcare needs. After the recognition of Vitex negundo L. (lagundi) as an important and effective alternative medicine for cough, sore throat, asthma and fever by the Philippine Department of Health (DOH), there was an increase in the production of lagundi-based herbal products in the form of teas, capsules and syrups. The efficiency of these products is greatly reliant on the use of authentic plant material, and to this day no standard protocol has been established to authenticate plant materials. DNA barcoding offers a quick and reliable species authentication tool, but its application to plant material has been less successful due to (1) lack of a standard DNA barcoding loci in plants and (2) poor DNA yield from powderised plant products. This study reports the successful application of DNA barcoding in the authentication of five V. negundo herbal products sold in the Philippines. Also, the first standard reference material (SRM) herbal library for the recognition of authentic V. negundo samples was established using 42 gene accessions of ITS, psbA-trnH and matK barcoding loci. Authentication of the herbal products utilised the SRM following the BLASTn and maximum-likelihood (ML) tree construction criterion. Barcode sequences were retrieved for ITS and psbA-trnH of all products tested and the results of the study revealed that only one out of five herbal products satisfied both BLASTn and ML criterion and was considered to contain authentic V. negundo. The results prompt the urgent need to utilise DNA barcoding in authenticating herbal products available in the Philippine market. Authentication of these products will secure consumer health by preventing the negative effects of adulteration, substitution and contamination.

  13. Preparation, characterization and certification of uranium isotope reference materials; Preparacao, Caracterizacao e certificacao de materiais de referencia isotopicos de uranio

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira Junior, Olivio Pereira de

    2006-07-01

    This work describes the preparation, characterization and certification of a set of uranium isotope reference materials ranging from 0.5 to 20.0 % of {sup 235}U in mass. The most important concepts of metrology in chemical measurements were applied so that the certified quantities in these materials could be directly traceable to the International System of Units (SI). As a consequence of this approach, these materials can be used in the instruments calibration, estimation of measurement uncertainty, method validation, assessment of performance of analysts, quality control routines and interlaboratory comparison programmes. The most advanced methods and techniques in mass spectrometry, that is, gas source mass spectrometry (GSMS), thermal ionisation mass spectrometry (TIMS) and inductively coupled plasma mass spectrometry (ICPMS) were investigated to identify which are the dominant components in the uncertainty and to quantify its contribution to the final value of the measurement uncertainty of the isotopic ratio. The results obtained were then compared to verify which are the methods and techniques associated to the lowest measurement uncertainty values. The isotope amount ratio n({sup 235}U)/n({sup 238}U) was certified in the materials produced to expanded uncertainties ranging from 0.02 to 0.10 % and the ratios n({sup 234}U)/n({sup 238}U) and n({sup 236}U)/n({sup 238}U), to uncertainties ranging from 0.03 to 2.20 %. These values fully comply to the requirements of the isotopic characterization of nuclear fuel as well as the analysis of environmental samples for nuclear safeguards. (author)

  14. Determination of selected oxygenated polycyclic aromatic hydrocarbons (oxy-PAHs) in diesel and air particulate matter standard reference materials (SRMs).

    Science.gov (United States)

    Nocun, Margarete S; Schantz, Michele M

    2013-06-01

    Oxygenated polycyclic aromatic hydrocarbons (oxy-PAHs) have recently received much attention in discussions regarding the negative impacts of particulate matter (PM) on human health and the environment. The National Institute of Standards and Technology provides several environmental matrix standard reference materials (SRMs) with certified and reference values for polycyclic aromatic hydrocarbons (PAHs) and nitrated PAHs. In this study, the concentrations of oxygenated PAHs are determined in three air PM SRMs (1649b, 1648a, and 2786) and three diesel PM SRMs (1650b, 2975, and 1975) using two independent gas chromatography-mass spectrometry methods. Concentrations of oxy-PAHs were at the milligrams per kilogram level with higher overall concentrations in diesel PM (up to 50 mg/kg for 9,10-anthraquinone). One of the highest oxy-PAH concentrations (up to 5 mg/kg) measured in the air particulate SRMs was for 7,12-benz[a]anthracenquinone. These results suggest that oxygenated PAHs should not be neglected in the analysis of PM as their concentrations can be as high as those of some PAHs and are one to two orders of magnitude higher than those for nitro-PAHs.

  15. The influence of Saccharomyces cerevisiae enzyme ratio on preparation virgin coconut oil for candidate in-house reference materials

    Science.gov (United States)

    Rohyami, Yuli; Anjani, Rafika Debby; Purwanti, Napthalina Putri

    2017-03-01

    Virgin coconut oil is an excellent product which has result of oil processing business opportunities in the international market. Standardization of virgin coconut oil necessary to satisfy the requirements industry needs. This research is expected as procedure preparation of reference materials. Preparation of virgin coconut oil by Sacharomycescerevisiaeenzyme. Based on the results of this study concluded that the ratio of Saccharomyces cerevisiae can affect the yield of virgin coconut oil produced. The preparation of virgin coconut oil enzymatically using a variety of mass ratio of 0.001 to 0.006% is obtained yield average of 12.40%. The optimum separation of virgin coconut oil on the use of enzymes with a mass ratio of 0.002%. The average water content at a ratio of 0.002% is 0.04 % with a value of uncertainty is 0.005%. The average iodine number in virgin coconut oil produced is 2.4403 ± 0,1974 grams of iodine per 100 grams of oil and optimum iodine number is obtained from the manufacturing process virgin coconut oil with a ratio of 0.006% Saccharomyces cerevisiae. Sacharomycescerevisiae with a ratio of 0.002% results virgin coconut oil with acid number 0.3068 ± 0.1098%. The peroxide value of virgin coconut oil between 0.0108 ± 0.009 to 0.0114 ± 0015milli-equivalent per kilograms. Organoleptic test results and test chemical parameters can be used as the test data that can be developed in prototype preparation of candidate in-house reference material in the testing standards of quality virgin coconut oil.

  16. Surface Reference Materials

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Manuals and instructions for observing the weather and recording observations. Includes the Weather Bureau Circulars published from 1889 through the 1950s, and the...

  17. Marine Reference Materials

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Various publications and other instructions for taking marine weather observations. includes Weather Service Observing Handbook No. 1, Weather Bureau Circular M, and...

  18. Upper Air Reference Materials

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Instructions for observing and recording radiosonde, pilot balloon and other in-situ observations above the earth's surface. Includes Weather Bureau Circular O.

  19. Toward standardization of carbohydrate-deficient transferrin (CDT) measurements: II. Performance of a laboratory network running the HPLC candidate reference measurement procedure and evaluation of a candidate reference material.

    Science.gov (United States)

    Helander, Anders; Wielders, Jos P M; Jeppsson, Jan-Olof; Weykamp, Cas; Siebelder, Carla; Anton, Raymond F; Schellenberg, François; Whitfield, John B

    2010-11-01

    Carbohydrate-deficient transferrin (CDT) is a descriptive term used for a temporary change in the transferrin glycosylation profile caused by alcohol, and used as a biomarker of chronic high alcohol consumption. The use of an array of methods for measurement of CDT in various absolute or relative amounts, and sometimes covering different transferrin glycoforms, has complicated the comparability of results and caused confusion among medical staff. This situation prompted initiation of an IFCC Working Group on CDT standardization. This second publication of the WG-CDT covers the establishment of a network of reference laboratories running a high-performance liquid chromatography (HPLC) candidate reference measurement procedure, and evaluation of candidate secondary reference materials. The network laboratories demonstrated good and reproducible performance and thus can be used to assign target values for calibrators and controls. A candidate secondary reference material based on native human serum lyophilized with a cryo-/lyoprotectant to prevent protein denaturation was found to be commutable and stable during storage. A proposed strategy for calibration of different CDT methods is also presented. In an external quality assurance study involving 66 laboratories and covering the current routine CDT assays (HPLC, capillary electrophoresis and immunoassay), recalculation of observed results based on the nominal values for the candidate calibrator reduced the overall coefficient of variation from 18.9% to 5.5%. The logistics for distribution of reference materials and review of results were found to be functional, indicating that a full reference system for CDT may soon be available.

  20. Development of a standard reference material containing 22 chlorinated hydrocarbon gases at 1 μmol/mol in nitrogen.

    Science.gov (United States)

    Li, Ning; Du, Jian; Yang, Jing; Fan, Qiang; Tian, Wen

    2017-09-08

    A gas standard mixture containing 22 chlorinated hydrocarbons in high purity nitrogen was prepared using a two-step weighing method and a gasifying apparatus developed in-house. The concentration of each component was determined using a gas chromatograph with flame ionization detection (GC/FID). Linear regression analysis of every component was performed using the gas standard mixture with concentrations ranging from 1 to 10 μmol/mol, showing the complete gasification of volatile organic compound (VOCs) species in a selected cylinder. Repeatability was also examined to ensure the reliability of the preparation method. In addition, no significant difference was observed between domestic treated and imported treated cylinders, which were conducive to reduction of the cost of raw materials. Moreover, the results of stability testing at different pressures and long-term stability tests indicated that the gas standard at 1 μmol/mol level with relative expanded uncertainties of 5% was stable above 2 MPa for a minimum of 12 months. Finally, a quantity comparison was conducted between the gas standard and a commercial gas standard from Scott Specialty Gases (now Air Liquide America Specialty Gases). The excellent agreement of every species suggested the favorable accuracy of our gas standard. Therefore, this reference material can be applied to routine observation of VOCs and for other purposes.

  1. Chemical Bonding and Structural Information of Black CarbonReference Materials and Individual Carbonaceous AtmosphericAerosols

    Energy Technology Data Exchange (ETDEWEB)

    Hopkins, Rebecca J.; Tivanski, Alexei V.; Marten, Bryan D.; Gilles, Mary K.

    2007-04-25

    The carbon-to-oxygen ratios and graphitic nature of a rangeof black carbon standard reference materials (BC SRMs), high molecularmass humic-like substances (HULIS) and atmospheric particles are examinedusing scanning transmission X-ray microscopy (STXM) coupled with nearedge X-ray absorption fine structure (NEXAFS) spectroscopy. UsingSTXM/NEXAFS, individual particles with diameter>100 nm are studied,thus the diversity of atmospheric particles collected during a variety offield missions is assessed. Applying a semi-quantitative peak fittingmethod to the NEXAFS spectra enables a comparison of BC SRMs and HULIS toparticles originating from anthropogenic combustion and biomass burns,thus allowing determination of the suitability of these materials forrepresenting atmospheric particles. Anthropogenic combustion and biomassburn particles can be distinguished from one another using both chemicalbonding and structural ordering information. While anthropogeniccombustion particles are characterized by a high proportion ofaromatic-C, the presence of benzoquinone and are highly structurallyordered, biomass burn particles exhibit lower structural ordering, asmaller proportion of aromatic-C and contain a much higher proportion ofoxygenated functional groups.

  2. A new series of uranium isotope reference materials for investigating the linearity of secondary electron multipliers in isotope mass spectrometry

    Science.gov (United States)

    Richter, S.; Alonso, A.; Aregbe, Y.; Eykens, R.; Kehoe, F.; Kühn, He; Kivel, N.; Verbruggen, A.; Wellum, R.; Taylor, P. D. P.

    2009-04-01

    A new series of gravimetrically prepared uranium isotope reference materials, the so-called IRMM-074 series, with the n(235U)/n(238U) isotope ratio held constant at unity and the n(233U)/n(238U) isotope ratios varying from 1.0 to 10-6 has been prepared and certified. This series is suited for calibration of secondary electron multipliers used widely in isotope mass spectrometry, in particular for techniques such as thermal ionization mass spectrometry (TIMS), inductively coupled plasma mass spectrometry (ICPMS), accelerator mass spectrometry (AMS) and resonance ionization mass spectrometry (RIMS). The new IRMM-074 was prepared as a replacement for the already exhausted IRMM-072 predecessor series. Uranium materials with high isotopic enrichments of 233U, 235U and 238U were purified using identical methods involving separation on anion and cation column followed by a precipitation as peroxide. The oxides were calcined to convert them to U3O8 simultaneously, in an oven installed in a glove-box that provided a controlled low-humidity environment. The oxides of 235U and 238U were weighed and mixed with a mole ratio n(235U)/n(238U) = 1.0 and then dissolved. The 233U oxide was dissolved to form a separate solution with the same concentration and 6rom this primary solution three dilutions were made by weighing. A weighed amount of the n(235U)/n(238U) solution and weighed amounts of the 233U solutions were mixed in various proportions in order to achieve n(233U)/n(238U) isotope ratios varying from 1.0 to 10-6. The methods for the preparation, the mixing and the mixing calculations are described. The expanded uncertainties (coverage factor k = 2) of the certified isotope ratios for the IRMM-074 series are 0.015% for the n(235U)/n(238U) ratio and 0.025% for the n(233U)/n(238U) ratios, which constitutes an improvement compared to those of the predecessor IRMM-072 series. In addition, recent observations regarding the linearity response of secondary electron multipliers (SEMs

  3. Nicotine, acetanilide and urea multi-level2H-,13C- and15N-abundance reference materials for continuous-flow isotope ratio mass spectrometry

    Science.gov (United States)

    Schimmelmann, A.; Albertino, A.; Sauer, P.E.; Qi, H.; Molinie, R.; Mesnard, F.

    2009-01-01

    Accurate determinations of stable isotope ratios require a calibration using at least two reference materials with different isotopic compositions to anchor the isotopic scale and compensate for differences in machine slope. Ideally, the S values of these reference materials should bracket the isotopic range of samples with unknown S values. While the practice of analyzing two isotopically distinct reference materials is common for water (VSMOW-SLAP) and carbonates (NBS 19 and L-SVEC), the lack of widely available organic reference materials with distinct isotopic composition has hindered the practice when analyzing organic materials by elemental analysis/isotope ratio mass spectrometry (EA-IRMS). At present only L-glutamic acids USGS40 and USGS41 satisfy these requirements for ??13C and ??13N, with the limitation that L-glutamic acid is not suitable for analysis by gas chromatography (GC). We describe the development and quality testing of (i) four nicotine laboratory reference materials for on-line (i.e. continuous flow) hydrogen reductive gas chromatography-isotope ratio mass-spectrometry (GC-IRMS), (ii) five nicotines for oxidative C, N gas chromatography-combustion-isotope ratio mass-spectrometry (GC-C-IRMS, or GC-IRMS), and (iii) also three acetanilide and three urea reference materials for on-line oxidative EA-IRMS for C and N. Isotopic off-line calibration against international stable isotope measurement standards at Indiana University adhered to the 'principle of identical treatment'. The new reference materials cover the following isotopic ranges: ??2Hnicotine -162 to -45%o, ??13Cnicotine -30.05 to +7.72%, ?? 15Nnicotine -6.03 to +33.62%; ??15N acetanilide +1-18 to +40.57%; ??13Curea -34.13 to +11.71%, ??15Nurea +0.26 to +40.61% (recommended ?? values refer to calibration with NBS 19, L-SVEC, IAEA-N-1, and IAEA-N-2). Nicotines fill a gap as the first organic nitrogen stable isotope reference materials for GC-IRMS that are available with different ??13N

  4. Advances in the Metrology of Absolute Value Assignments to Isotopic Reference Materials: Consequences from the Avogadro Project

    Science.gov (United States)

    Vocke, Robert; Rabb, Savelas

    2015-04-01

    All isotope amount ratios (hereafter referred to as isotope ratios) produced and measured on any mass spectrometer are biased. This unfortunate situation results mainly from the physical processes in the source area where ions are produced. Because the ionized atoms in poly-isotopic elements have different masses, such processes are typically mass dependent and lead to what is commonly referred to as mass fractionation (for thermal ionization and electron impact sources) and mass bias (for inductively coupled plasma sources.) This biasing process produces a measured isotope ratio that is either larger or smaller than the "true" ratio in the sample. This has led to the development of numerous fractionation "laws" that seek to correct for these effects, many of which are not based on the physical processes giving rise to the biases. The search for tighter and reproducible precisions has led to two isotope ratio measurement systems that exist side-by-side. One still seeks to measure "absolute" isotope ratios while the other utilizes an artifact based measurement system called a delta-scale. The common element between these two measurement systems is the utilization of isotope reference materials (iRMs). These iRMs are used to validate a fractionation "law" in the former case and function as a scale anchor in the latter. Many value assignments of iRMs are based on "best measurements" by the original groups producing the reference material, a not entirely satisfactory approach. Other iRMs, with absolute isotope ratio values, have been produced by calibrated measurements following the Atomic Weight approach (AW) pioneered by NBS nearly 50 years ago. Unfortunately, the AW is not capable of calibrating the new generation of iRMs to sufficient precision. So how do we get iRMs with isotope ratios of sufficient precision and without bias? Such a focus is not to denigrate the extremely precise delta-scale measurements presently being made on non-traditional and tradition

  5. A preliminary study for the development of reference material using oyster for determination of (137)Cs, (90)Sr and plutonium isotopes.

    Science.gov (United States)

    Lee, Sang-Han; Oh, Jung-Suk; Lee, Jong-Man; Lee, Kyung-Bum; Park, Tae-Soon; Lee, Min-Kie; Kim, Seung-Hwan; Choi, Jong-Ki

    2016-03-01

    A new reference material for the determination of (137)Cs, (90)Sr and Pu isotopes ((238)Pu and (239,240)Pu) is being developed using dried oyster matrix by Korea Research Institute of Standards and Science (KRISS). The oyster was collected from Tongyoung harbour, southern part of Korea and the artificial radionuclides ((137)Cs, (90)Sr, (238)Pu and (239,240)Pu) were spiked into the material. After pretreatment and processing, the material was tested for homogeneity and massic activities were determined by measuring (137)Cs, (90)Sr, (238)Pu and (239,240)Pu. The reference value and extended uncertainty for those isotopes will be reported later.

  6. Utility of NIST Whole-Genome Reference Materials for the Technical Validation of a Multigene Next-Generation Sequencing Test.

    Science.gov (United States)

    Shum, Bennett O V; Henner, Ilya; Belluoccio, Daniele; Hinchcliffe, Marcus J

    2017-07-01

    The sensitivity and specificity of next-generation sequencing laboratory developed tests (LDTs) are typically determined by an analyte-specific approach. Analyte-specific validations use disease-specific controls to assess an LDT's ability to detect known pathogenic variants. Alternatively, a methods-based approach can be used for LDT technical validations. Methods-focused validations do not use disease-specific controls but use benchmark reference DNA that contains known variants (benign, variants of unknown significance, and pathogenic) to assess variant calling accuracy of a next-generation sequencing workflow. Recently, four whole-genome reference materials (RMs) from the National Institute of Standards and Technology (NIST) were released to standardize methods-based validations of next-generation sequencing panels across laboratories. We provide a practical method for using NIST RMs to validate multigene panels. We analyzed the utility of RMs in validating a novel newborn screening test that targets 70 genes, called NEO1. Despite the NIST RM variant truth set originating from multiple sequencing platforms, replicates, and library types, we discovered a 5.2% false-negative variant detection rate in the RM truth set genes that were assessed in our validation. We developed a strategy using complementary non-RM controls to demonstrate 99.6% sensitivity of the NEO1 test in detecting variants. Our findings have implications for laboratories or proficiency testing organizations using whole-genome NIST RMs for testing. Copyright © 2017 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

  7. The Kjeldahl method as a primary reference procedure for total protein in certified reference materials used in clinical chemistry. I. A review of Kjeldahl methods adopted by laboratory medicine.

    Science.gov (United States)

    Chromý, Vratislav; Vinklárková, Bára; Šprongl, Luděk; Bittová, Miroslava

    2015-01-01

    We found previously that albumin-calibrated total protein in certified reference materials causes unacceptable positive bias in analysis of human sera. The simplest way to cure this defect is the use of human-based serum/plasma standards calibrated by the Kjeldahl method. Such standards, commutative with serum samples, will compensate for bias caused by lipids and bilirubin in most human sera. To find a suitable primary reference procedure for total protein in reference materials, we reviewed Kjeldahl methods adopted by laboratory medicine. We found two methods recommended for total protein in human samples: an indirect analysis based on total Kjeldahl nitrogen corrected for its nonprotein nitrogen and a direct analysis made on isolated protein precipitates. The methods found will be assessed in a subsequent article.

  8. Advance in Developing Genetically Modified Plant Reference Material%转基因植物标准物质研究进展

    Institute of Scientific and Technical Information of China (English)

    董莲华; 赵正宜; 李亮; 隋志伟; 王晶

    2012-01-01

    转基因产品的安全性一直都备受关注,因此转基因产品的定性、定量检测越来越重要,而转基因标准物质的使用是转基因产品检测结果有效和可比的重要保证.本文针对国内外转基因植物标准物质的研究现状及相关技术进行综述,重点介绍了转基因植物标准物质的种类、转基因标准物质定值技术,分析了转基因标准物质研制过程中的关键点.更重要的是综述并提出了质粒DNA分子标准物质的定值模式,包括如何合理评价质粒分子可替代性问题,此外还总结了目前国外转基因标准物质的种类,目的是为我国转基因植物标准物质研制和相关研究提供有价值的参考.%In the p ast two decades, many countries have been paying more attention to safety of genetically modified (GM) product, and thus, qualitative and quantitative test of GM products become more and more important. The test result can be more comparable and reliable by using GM reference material. This paper reviews the research progress of GM reference material and related techniques: it introduces the variety of GM reference material and techniques of value assignment for GM reference material, and also evaluates the key procedures in developing GM reference material. More importantly, it is concluded that how to assign the reference value for the plasmid reference material including the commutability between the plasmid and genomic DNA. Additionally, it summarizes the current international GM certified reference material. This aims to provide some valuable reference for developing GM reference material in China.

  9. Hair analysis for drugs of abuse: evaluation of analytical methods, environmental issues, and development of reference materials.

    Science.gov (United States)

    Welch, M J; Sniegoski, L T; Allgood, C C; Habram, M

    1993-01-01

    Methods for extraction of cocaine, some of its metabolites, morphine, and codeine from hair and methods for analyzing the extracts have been investigated. Results of these studies have shown that extractions with 0.1N HCl are efficient at removing the target compounds from hair and appear to be as effective as enzymatic digestions that dissolve the hair. GC/MS with either electron ionization or chemical ionization was found to provide accurate and unambiguous determinations of the target compounds. Tandem mass spectrometry (MS/MS) also provided accurate results when performed on extracts from hair, but results were ambiguous when MS/MS was performed on hair segments directly. Environmental issues, including the removal of powdered and vapor-deposited cocaine from the hair surface and the effect of various hair treatments on the levels of cocaine entrapped in hair, have also been investigated. Removal of cocaine deposited on hair was incomplete by all approaches tested, making differentiation of hair of cocaine users from hair with environmental exposure of cocaine difficult. Cocaethylene, a cocaine metabolite believed to be formed in the liver, was found in the hair of some cocaine users and may be a good marker for proving drug use. Common hair treatments, such as shampoos, conditioners, and peroxide bleaches, reduced cocaine levels in a fortified hair material by 60 to 80% after 30 treatments. Finally, to assist laboratories in evaluating the accuracy of their methods, two human hair reference materials with recommended concentrations of cocaine, benzoylecgonine, morphine, and codeine determined by GC/MS have been developed.

  10. Determination of non-certified levoglucosan, sugar polyols and ergosterol in NIST Standard Reference Material 1649a

    Science.gov (United States)

    Pomata, Donatella; Di Filippo, Patrizia; Riccardi, Carmela; Buiarelli, Francesca; Gallo, Valentina

    2014-02-01

    Organic component of airborne particulate matter originates from both natural and anthropogenic sources whose contributions can be identified through the analysis of chemical markers. The validation of analytical methods for analysis of compounds used as chemical markers is of great importance especially if they must be determined in rather complex matrices. Currently, standard reference materials (SRM) with certified values for all those analytes are not available. In this paper, we report a method for the simultaneous determination of levoglucosan and xylitol as tracers for biomass burning emissions, and arabitol, mannitol and ergosterol as biomarkers for airborne fungi in SRM 1649a, by GC/MS. Their quantitative analysis in SRM 1649a was carried out using both internal standard calibration curves and standard addition method. A matrix effect was observed for all analytes, minor for levoglucosan and major for polyols and ergosterol. The results related to levoglucosan around 160 μg g-1 agreed with those reported by other authors, while no comparison was possible for xylitol (120 μg g-1), arabitol (15 μg g-1), mannitol (18 μg g-1), and ergosterol (0.5 μg g-1). The analytical method used for SRM 1649a was also applied to PM10 samples collected in Rome during four seasonal sampling campaigns. The ratios between annual analyte concentrations in PM10 samples and in SRM 1649a were of the same order of magnitude although particulate matter samples analyzed were collected in two different sites and periods.

  11. Determination of caffeine, theobromine, and theophylline in standard reference material 2384, baking chocolate, using reversed-phase liquid chromatography.

    Science.gov (United States)

    Thomas, Jeanice Brown; Yen, James H; Schantz, Michele M; Porter, Barbara J; Sharpless, Katherine E

    2004-06-02

    A rapid and selective isocratic reversed-phase liquid chromatographic method has been developed at the National Institute of Standards and Technology to simultaneously measure caffeine, theobromine, and theophylline in a food-matrix standard reference material (SRM) 2384, Baking Chocolate. The method uses isocratic elution with a mobile phase composition (volume fractions) of 10% acetronitrile/90% water (pH adjusted to 2.5 using acetic acid) at a flow rate of 1.5 mL/min with ultraviolet absorbance detection (274 nm). Total elution time for these analytes is less than 15 min. Concentration levels of caffeine, theobromine, and theophylline were measured in single 1-g samples taken from each of eight bars of chocolate over an eight-day period. Samples were defatted with hexane, and beta-hydroxyethyltheophylline was added as the internal standard. The repeatability for the caffeine, theobromine, and theophylline measurements was 5.1, 2.3, and 1.9%, respectively. The limit of quantitation for all analytes was theobromine, and theophylline in SRM 2384.

  12. Preparation and certification of hijiki reference material, NMIJ CRM 7405-a, from the edible marine algae hijiki (Hizikia fusiforme).

    Science.gov (United States)

    Narukawa, Tomohiro; Inagaki, Kazumi; Zhu, Yanbei; Kuroiwa, Takayoshi; Narushima, Izumi; Chiba, Koichi; Hioki, Akiharu

    2012-02-01

    A certified reference material, NMIJ CRM 7405-a, for the determination of trace elements and As(V) in algae was developed from the edible marine hijiki (Hizikia fusiforme) and certified by the National Metrology Institute of Japan (NMIJ), the National Institute of Advanced Industrial Science and Technology (AIST). Hijiki was collected from the Pacific coast in the Kanto area of Japan, and was washed, dried, powdered, and homogenized. The hijiki powder was placed in 400 bottles (ca. 20 g each). The concentrations of 18 trace elements and As(V) were determined by two to four independent analytical techniques, including (ID)ICP-(HR)MS, ICP-OES, GFAAS, and HPLC-ICP-MS using calibration solutions prepared from the elemental standard solution of Japan calibration service system (JCSS) and the NMIJ CRM As(V) solution, and whose concentrations are certified and SI traceable. The uncertainties of all the measurements and preparation procedures were evaluated. The values of 18 trace elements and As(V) in the CRM were certified with uncertainty (k = 2).

  13. 基于多重指标下ABC分类法的煤矿库存物资分类%Stock Material Classification for Coal Mine Based on Multiple Criteria ABC Classification

    Institute of Scientific and Technical Information of China (English)

    杨娟; 郭海湘; 杨文霞; 诸克军

    2011-01-01

    传统的ABC分类法基于年销售额单一度量标准,容易忽视其它影响库存物资的因素.鉴于此,本文应用多重指标的ABC分类法对郑州煤电物资供销公司的库存物资进行分类.文中比较了两个指标(月平均使用金额与提前期)、三个指标(月平均使用金额、月平均单位库存成本或月平均单位成本与提前期)及五个指标(月平均使用数量、提前期、供应商数量、月平均单位库存成本、月平均销售成本)的分类效果,另外,提前期的取值也分别采用最大值、最小值、平均值进行了计算.与现场管理者的经验值比较,结果表明采用两个指标(月平均使用金额与提前期)且提前期取最小值的吻合效果最好.本研究成果可应用于煤矿物资的分类,可根据具体实际情况,添加度量物资重要性的指标.%ABC classification based on only single measurement such as annual dollar usage easily ignores other criteria also recognized important in stock material classification. In this paper, multiple criteria ABC classification is applied to classify stock materials into different groups for zhengzhou materials supply and marketing company. Different classification results are presented respectively considering two criteria (monthly dollar usage and lead time) , three criteria( monthly dollar usage, monthly average unit inventory cost or monthly average unit cost and lead time) and five criteria( monthly average usage amount, lead time, the number of suppliers, monthly average unit stock cost, monthly average sale cost). In addition, lead time is calculated respectively with its maximal, minimal, average. Compared with the local manager' s experience, the result proves that the matching effect is the best while using two criteria( monthly average dollar usage and lead time ) and lead time minimal to measure inventory material. The result may be applied to classify materials into different groups by adding the criteria

  14. The development of the first set of Brazilian reference materials for the petroleum sector; O desenvolvimento dos primeiros materiais de referencia nacionais para o setor de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Zucchini, Ricardo R. [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil). Agrupamento de Materiais de Referencia

    2004-07-01

    The petroleum sector uses a number of standardized tests to characterize raw materials and products. The development of in-company programs for assurance of measurement quality, the increasing need to demonstrate proficiency by means of certification schemes or by widely accepted metrological practices, have been promoting a more intensive use of certified reference materials, in calibration as well as in validation of measurement methods and also in order to show the qualification of the laboratories. In this paper it is presented the preparation, performed by IPT's Reference Materials Group, of the first set of reference materials specially developed considering the needs of the petroleum community. Briefly, are presented the identification of the demands from the users, selection of matrices, homogeneity tests and stability studies, and the certification of the new reference materials, which are four diesel fuel oils with certified sulfur contents and one material with flash point certified by TAG and Pensky-Martens methods. It is presented a summary of the certification process, performed by means of a combined effort of several professionals that are now working at laboratories of research institutions, refineries and other industries, universities, fuel monitoring facilities and in National Petroleum Agency. (author)

  15. Feasibility of the development of reference materials for the detection of Ag nanoparticles in food: neat dispersions and spiked chicken meat

    DEFF Research Database (Denmark)

    Grombe, Ringo; Allmaier, Günter; Charoud-Got, Jean

    2015-01-01

    -ICP-MS, as well as AgNP particle size by dynamic light scattering, transmission electron microscopy (TEM) and gas-phase electrophoretic molecular mobility analysis. Chicken breasts were homogenized by cryo-milling and spiked with aqueous AgNP dispersions. Rapid freezing over liquid nitrogen resulted......The feasibility of producing colloidal silver nanoparticle reference materials and silver nanoparticle spiked reference matrix materials was investigated. Two concentrations of PVP-coated silver nanoparticle dispersions were evaluated and used to spike chicken meat, with the aim of producing a set...... of reference materials to support the development of analytical methods for the detection and quantification of nanoparticles in food. Aqueous silver nanoparticle (AgNP) dispersions were evaluated for their homogeneity of mass fraction and particle size and found sufficiently homogeneous to be used...

  16. 美军EPAS系统对我军士兵职业分类研究的启示%The Reference of EPAS for the PLA Soldier Classification System

    Institute of Scientific and Technical Information of China (English)

    张家喜; 肖玮; 石蕊; 苗丹民

    2011-01-01

    The purpose of this paper is to introduce a person-job-match method in the military domain, the Enlisted Personnel Allocation System(EPAS). EPAS is the a latest classification methodology that optimally allocates recruits to jobs so as to maximize the predicted performance of an accession cohort whilemeeting military job fill, distribution, and timing requirements, and can significantly improve the military personnel classification with a linear programming optimization software program. This article providesa brief history of EPAS, describes how it enhances the effectiveness of classification, then discusses how to develop and comprise a classification system for the People's Liberation Army (PLA) by taking reference from it. Classification is the process of assigning new enlisted personnel to initial job training in the Army. Unlike selection, classification brings the job to the right man. U. S. Army's classification system is based on a long history of research. Shortly after World War I1, the U.S. Army started investigations of improved methods for classification. However, significant and exalting research strides in the classification area have just been made recently and have yet to be tested out in the Army's operations. It is worth noting that Project A and Project B conducted over the 1980s made huge contributions to classification theory improvement. The PC prototype of EPAS development began in the fall of 1993 and was largely completed by the spring of 1997. A fruitfid field test evaluation which was conducted over 2001 - 2003 will be transparent to army applicants and career counselors. The U. S. Army currently takes a minimum enlistment standard approach to classification: identifying high priority Military Occupational Specialty (MOS) for which the soldiers meet the minimum Aptitude Area composite score qualifications. EPAS attempts to go beyond this and make a better use of each recruit' s potential. Through Aptitude Area

  17. 语篇转喻:照应的符号学分析与分类%Textual Metonymy:A Semiotic Analysis and Classification of Reference

    Institute of Scientific and Technical Information of China (English)

    幸君臖; 史晓慧

    2014-01-01

    《英语中的衔接》一书的出版引起了人们对照应等衔接关系的关注。通过对语篇转喻和衔接之间关系的研究,将语言、认知和语境纳入同一框架下,对照应成分进行符号学的解读,揭示衔接系统中照应的工作机制,并根据照应的工作机制将人称照应和指示照应进一步分为直陈式照应和转喻式照应,使照应系统分类更具体更精密。%The publication of Cohesion in English prompted various studies on cohesion and its ties, including reference.The present paper tries to conduct a textual metonymic study of reference so as to reveal its mechanisms with a semiotic metonymic model which integrates language, cognition and context into a tri-dimensional whole.Then,based on the different mechanisms generating referential relations,the paper categorizes reference into congruent reference and metonymic reference,making the reference system more delicate.

  18. Preparation and certification of the Polish reference material Virginia Tobacco Leaves (CTA-VTL-2) for inorganic trace analysis including microanalysis

    Energy Technology Data Exchange (ETDEWEB)

    Dybczynski, R.; Polkowska-Motrenko, H.; Samczynski, Z.; Szopa, Z.

    1997-12-31

    A new Polish certified reference material Virginia Tobacco Leaves (CTA-VTL-2) for inorganic trace analysis including microanalysis has been prepared. Certification of the candidate reference material was based on the world-wide interlaboratory comparison in which 60 laboratories from 18 countries, participated using various analytical methods and techniques. Data evaluation performed by means of the new multifunctional software package -SSQC. Recommended values were assigned for 33 and `information` values for 10 elements, respectively. The validity of `certified` values was confirmed for several elements using `very accurate` methods developed in this Laboratory. (author). 47 refs, 28 figs, 12 tabs.

  19. Desenvolvimento de material de referência para microbiologia de alimentos contendo Listeria monocytogenes em matriz queijo

    Directory of Open Access Journals (Sweden)

    Marcelo Luiz Lima Brandão

    2013-10-01

    Full Text Available A NBR ISO/IEC 17025:2005, uma das normas mais utilizadas em laboratórios de ensaio, descreve como um de seus critérios para a garantia da qualidade dos resultados analíticos a participação periódica dos laboratórios em ensaios de proficiência (EP. Os analitos, utilizados nos EP são materiais de referência (MR provenientes de um mesmo lote, e devem apresentar características de homogeneidade e estabilidade. O objetivo deste estudo foi produzir um MR qualitativo destinado ao ensaio de pesquisa de Listeria monocytogenes em matriz queijo pela técnica de liofilização. Para a produção do MR, foi utilizado como matriz o queijo Minas frescal (QMF ultrafiltrado. A matriz foi distribuída em frascos, contaminada com a bactéria alvo e submetida à liofilização, tendo a sacarose como crioprotetor. O MR produzido foi considerado homogêneo e estável na temperatura de ≤-70°C durante todo o período estudado (10 meses. O material apresentou estabilidade a 4, 25, 30 e 35°C por quatro dias e a -20°C por 48 dias, e os resultados estatísticos indicam tendência à estabilidade. Conclui-se que o material apresentou todos os requisitos necessários de um MR de qualidade e poderia ser transportado aos laboratórios participantes de um EP à temperatura máxima de 35°C por até quatro dias, uma vez que os resultados indicaram a manutenção da concentração celular nesse período. Esse foi o primeiro trabalho a descrever uma metodologia de produção de MR contendo L. monocytogenes em matriz queijo.

  20. Best Reference Sources 2001.

    Science.gov (United States)

    Coutts, Brian; McConnell, Tamara

    2002-01-01

    Presents an annotated list of the best reference materials published in 2001. Discusses activity in the reference publishing industry; costs; and lists print materials, Web sites, databases, and CD-ROMs. (LRW)

  1. Isolation and characterization of gluten protein types from wheat, rye, barley and oats for use as reference materials

    Science.gov (United States)

    Schalk, Kathrin; Lexhaller, Barbara; Koehler, Peter

    2017-01-01

    Gluten proteins from wheat, rye, barley and, in rare cases, oats, are responsible for triggering hypersensitivity reactions such as celiac disease, non-celiac gluten sensitivity and wheat allergy. Well-defined reference materials (RM) are essential for clinical studies, diagnostics, elucidation of disease mechanisms and food analyses to ensure the safety of gluten-free foods. Various RM are currently used, but a thorough characterization of the gluten source, content and composition is often missing. However, this characterization is essential due to the complexity and heterogeneity of gluten to avoid ambiguous results caused by differences in the RM used. A comprehensive strategy to isolate gluten protein fractions and gluten protein types (GPT) from wheat, rye, barley and oat flours was developed to obtain well-defined RM for clinical assays and gluten-free compliance testing. All isolated GPT (ω5-gliadins, ω1,2-gliadins, α-gliadins, γ-gliadins and high- and low-molecular-weight glutenin subunits from wheat, ω-secalins, γ-75k-secalins, γ-40k-secalins and high-molecular-weight secalins from rye, C-hordeins, γ-hordeins, B-hordeins and D-hordeins from barley and avenins from oats) were fully characterized using analytical reversed-phase high-performance liquid chromatography (RP-HPLC), sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), N-terminal sequencing, electrospray-ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS) and untargeted LC-MS/MS of chymotryptic hydrolyzates of the single GPT. Taken together, the analytical methods confirmed that all GPT were reproducibly isolated in high purity from the flours and were suitable to be used as RM, e.g., for calibration of LC-MS/MS methods or enzyme-linked immunosorbent assays (ELISAs). PMID:28234993

  2. Isolation and characterization of gluten protein types from wheat, rye, barley and oats for use as reference materials.

    Science.gov (United States)

    Schalk, Kathrin; Lexhaller, Barbara; Koehler, Peter; Scherf, Katharina Anne

    2017-01-01

    Gluten proteins from wheat, rye, barley and, in rare cases, oats, are responsible for triggering hypersensitivity reactions such as celiac disease, non-celiac gluten sensitivity and wheat allergy. Well-defined reference materials (RM) are essential for clinical studies, diagnostics, elucidation of disease mechanisms and food analyses to ensure the safety of gluten-free foods. Various RM are currently used, but a thorough characterization of the gluten source, content and composition is often missing. However, this characterization is essential due to the complexity and heterogeneity of gluten to avoid ambiguous results caused by differences in the RM used. A comprehensive strategy to isolate gluten protein fractions and gluten protein types (GPT) from wheat, rye, barley and oat flours was developed to obtain well-defined RM for clinical assays and gluten-free compliance testing. All isolated GPT (ω5-gliadins, ω1,2-gliadins, α-gliadins, γ-gliadins and high- and low-molecular-weight glutenin subunits from wheat, ω-secalins, γ-75k-secalins, γ-40k-secalins and high-molecular-weight secalins from rye, C-hordeins, γ-hordeins, B-hordeins and D-hordeins from barley and avenins from oats) were fully characterized using analytical reversed-phase high-performance liquid chromatography (RP-HPLC), sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), N-terminal sequencing, electrospray-ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS) and untargeted LC-MS/MS of chymotryptic hydrolyzates of the single GPT. Taken together, the analytical methods confirmed that all GPT were reproducibly isolated in high purity from the flours and were suitable to be used as RM, e.g., for calibration of LC-MS/MS methods or enzyme-linked immunosorbent assays (ELISAs).

  3. Development of a certified reference material (NMIJ CRM 7505-a) for the determination of trace elements in tea leaves.

    Science.gov (United States)

    Zhu, Yanbei; Narukawa, Tomohiro; Inagaki, Kazumi; Kuroiwa, Takayoshi; Chiba, Koichi

    2011-01-01

    A certified reference material (CRM) for trace elements in tea leaves has been developed in National Metrology Institute of Japan (NMIJ). The CRM was provided as a dry powder (<90 µm) after frozen pulverization of washed and dried fresh tea leaves from a tea plant farm in Shizuoka Prefecture, Japan. Characterization of the property value for each element was carried out exclusively by NMIJ with at least two independent analytical methods, including inductively coupled plasma mass spectrometry (ICP-MS), high-resolution (HR-) ICP-MS, isotope-dilution (ID-) ICP-MS, inductively coupled plasma optical emission spectrometry (ICP-OES), graphite-furnace atomic-absorption spectrometry (GF-AAS) and flame atomic-absorption spectrometry (FAAS). Property values were provided for 19 elements (Ca, K, Mg, P, Al, B, Ba, Cd, Cu, Fe, Li, Mn, Na, Ni, Pb, Rb, Sr, Zn and Co) and informative values for 18 elements (Ti, V, Cr, Y, and all of the lanthanides, except for Pm whose isotopes are exclusively radioactive). The concentration ranges of property values and informative values were from 1.59% (mass) of K to 0.0139 mg kg(-1) of Cd and from 0.6 mg kg(-1) of Ti to 0.0014 mg kg(-1) of Lu, respectively. Combined relatively standard uncertainties of the property values were estimated by considering the uncertainties of the homogeneity, analytical methods, characterization, calibration standard, and dry-mass correction factor. The range of the relative combined standard uncertainties was from 1.5% of Mg and K to 4.1% of Cd.

  4. Certification of Charpy V-Notch Reference Test Pieces of 30 J Nominal Absorbed Energy - Certified Reference Materials ERM®-FA013bg and ERM®-FA013bh

    OpenAIRE

    LAMBERTY MARIE ANDREE; Dean, Alan; Roebben, Gert

    2011-01-01

    This certification report describes the processing and characterisation of ERM®-FA013bg and ERM®-FA013bh, two batches of Charpy V-notch certified reference test pieces. Sets of five of these test pieces are used for the verification of pendulum impact test machines according to EN 10045-2 (Charpy impact test on metallic materials, Part 2. Method for the verification of impact testing machines [1]) or according to ISO 148-2 (Metallic materials - Charpy pendulum impact test - Part 2: Verificati...

  5. Development of two fine particulate matter standard reference materials (<4 μm and <10 μm) for the determination of organic and inorganic constituents.

    Science.gov (United States)

    Schantz, Michele M; Cleveland, Danielle; Heckert, N Alan; Kucklick, John R; Leigh, Stefan D; Long, Stephen E; Lynch, Jennifer M; Murphy, Karen E; Olfaz, Rabia; Pintar, Adam L; Porter, Barbara J; Rabb, Savelas A; Vander Pol, Stacy S; Wise, Stephen A; Zeisler, Rolf

    2016-06-01

    Two new Standard Reference Materials (SRMs), SRM 2786 Fine Particulate Matter (Particulate Matter (particulate matter (PM). These materials have been characterized for the mass fractions of selected polycyclic aromatic hydrocarbons (PAHs), nitrated PAHs, brominated diphenyl ether (BDE) congeners, hexabromocyclododecane (HBCD) isomers, sugars, polychlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF) congeners, and inorganic constituents, as well as particle-size characteristics. These materials are the first Certified Reference Materials available to support measurements of both organic and inorganic constituents in fine PM. In addition, values for PAHs are available for RM 8785 Air Particulate Matter on Filter Media. As such, these SRMs will be useful as quality control samples for ensuring compatibility of results among PM monitoring studies and will fill a void to assess the accuracy of analytical methods used in these studies. Graphical Abstract Removal of PM from filter for the preparation of SRM 2786 Fine Particulate Matter.

  6. Study of the structure and development of the set of reference materials of composition and structure of heat resisting nickel and intermetallic alloys

    Directory of Open Access Journals (Sweden)

    E. B. Chabina

    2016-01-01

    Full Text Available Relevance of research: There are two sizes (several microns and nanodimensional of strengthening j'-phase in single-crystal heat resisting nickel and intermetallic alloys, used for making blades of modern gas turbine engines (GTD. For in-depth study of structural and phase condition of such alloys not only qualitative description of created structure is necessary, but quantitative analysis of alloy components geometrical characteristics. Purpose of the work: Development of reference material sets of heat resisting nickel and intermetallic alloy composition and structure. Research methods: To address the measurement problem of control of structural and geometrical characteristics of single-crystal heat resisting and intermetallic alloys by analytical microscopy and X-ray diffraction analysis the research was carried out using certified measurement techniques on facilities, entered in the Register of Measurement Means of the Russian Federation. The research was carried out on microsections, foils and plates, cut in the plane {100}. Results: It is established that key parameters, defining the properties of these alloys are particle size of strengthening j' -phase, the layer thickness of j-phase between them and parameters of phases lattice. Metrological requirements for reference materials of composition and structure of heat resisting nickel and intermetallic alloys are formulated. The necessary and sufficient reference material set providing the possibility to determine the composition and structure parameters of single-crystal heat resisting nickel and intermetallic alloys is defined. The developed RM sets are certified as in-plant reference materials. Conclusion: The reference materials can be used for graduation of spectral equipment when conducting element analysis of specified class alloys; for calibration of means of measuring alloy structure parameters; for measurement of alloys phases lattice parameters; for structure reference pictures

  7. 2010年北京标准物质国际研讨会综述%Summary of RM 2010-Beijing International Symposium on Reference Materials

    Institute of Scientific and Technical Information of China (English)

    王亚平; 袁建; 许春雪

    2011-01-01

    This paper described the RM 2010-Beijing international symposium on reference materials, which is the largest conference in the history about reference materials international conference. The symposium was hosted by National Institute of Metrology P. R. China and supported by China Association for Instrumental Analysis and Chinese Society for Measurement. The themes of the symposium were mainly the current situation, future development trend, challenges of reference materials. The main themes included the relationships between the reference materials, environmental protection, international business and so on, the preparation, measurement methods and challenges for reference materials, current situations for national and international reference materials. The sessions of the symposium included about public security and health care, advanced materials for energy technology and environmental protection, developments and application of international reference materials, general analytical technology. The achievements in Chinese reference materials were presented through this conference and promoted the status of China about development of reference materials. The delegates communicated for the challenges and problems during the preparation for the reference materials. In this paper, we also summarized the main themes and the situation and application of Chinese reference materials, especially geological reference materials. Up to end of 2010, the totally 6011 kinds of referencematerials in China consists of 1701 first grade and 4310 second grade certified national reference materials, covering with steel, inorganic and industrial materials and so on. The numbers of reference materials reached international advanced level, however, there are some problems about lack of some species and categories along with unreasonable structure. The reference materials are short of in some important research fields as new resource, new energy, new materials, biology, clinical

  8. Classification of Horn of Africa School Children: Is It Appropriate for the Educational Authorities in England to Refer to Them as Refugees?

    Science.gov (United States)

    Kuyok, Kuyok Abol

    2010-01-01

    Drawing on evidence from a PhD study, this paper raises questions about the appropriateness of English educational authorities to continue to refer to the Horn of Africa children, most of them born in the UK, as refugees. The word refugee, in its broad definition, seemingly masks fundamental differences and may reinforce stereotypical perceptions…

  9. Comprehensive analysis for major, minor and trace element contents and Sr-Nd-Pb-Hf isotope ratios in sediment reference materials, JSd-1 and MAG-1

    Digital Repository Service at National Institute of Oceanography (India)

    Nath, B.N.; Makishima, A.; Noordmann, J.; Tanaka, R.; Nakamura, E.

    In view of the requirement of a well-characterized and easily available aquatic sediment reference material, a comprehensive analysis comprising of fifty major, minor and trace elements as well as Sr–Nd–Pb–Hf isotopes were carried out...

  10. Comprehensive inter-laboratory calibration of reference materials for delta O-18 versus VSMOW using various on-line high-temperature conversion techniques

    NARCIS (Netherlands)

    Brand, Willi A.; Coplen, Tyler B.; Aerts-Bijma, Anita T.; Böhlke, J.K.; Gehre, Matthias; Geilmann, Heike; Gröning, Manfred; Jansen, Henk G.; Meijer, Harro A. J.; Mroczkowski, Stanley J.; Qi, Haiping; Soergel, Karin; Stuart-Williams, Hilary; Weise, Stephan M.; Werner, Roland A.

    2009-01-01

    Internationally distributed organic and inorganic oxygen isotopic reference materials have been calibrated by six laboratories carrying out more than 5300 measurements using a variety of high-temperature conversion techniques (HTC)a in an evaluation sponsored by the International Union of Pure and A

  11. Organic Reference Materials for Hydrogen, Carbon, and Nitrogen Stable Isotope-Ratio Measurements : Caffeines, n-Alkanes, Fatty Acid Methyl Esters, Glycines, L-Valines, Polyethylenes, and Oils

    NARCIS (Netherlands)

    Schimmelrnann, Arndt; Qi, Haiping; Coplen, Tyler B.; Brand, Willi A.; Fong, Jon; Meier-Augenstein, Wolfram; Kemp, Helen F.; Toman, Blaza; Ackermann, Annika; Assonov, Sergey; Aerts-Bijma, Anita T.; Brejcha, Ramona; Chikaraishi, Yoshito; Darwish, Tamim; Elsner, Martin; Gehre, Matthias; Geilmann, Heike; Groeing, Manfred; Helie, Jean-Francois; Herrero-Martin, Sara; Meijer, Harro A. J.; Sauer, Peter E.; Sessions, Alex L.; Werner, Roland A.

    2016-01-01

    An international project developed, quality-tested, and determined isotope-delta values of 19 new organic reference materials (RMs) for hydrogen, carbon, and nitrogen stable isotope-ratio measurements, in addition to analyzing pre-existing RMs NBS 22 (oil), IAEA-CH-7 (polyethylene foil), and IAEA-60

  12. Feasibility study for the development of certified reference materials for specific migration testing. Part 1: Initial migrant concentration and specific migration

    NARCIS (Netherlands)

    Stoffers, N.H.; Störmer, A.; Bradley, E.L.; Brandsch, R.; Cooper, I.; Linssen, J.P.H.; Franz, R.

    2004-01-01

    The paper describes a project with the main objective of developing the know how to produce certified reference materials (CRMs) for specific migration testing. Certification parameters discussed are the initial concentration of the migrant in the polymer (C-P,C- 0) and the specific migration into a

  13. Feasibility study for the development of certified reference materials for specific migration testing. Part 2: Estimation of diffusion parameters and comparison of experimental and predicted data

    NARCIS (Netherlands)

    Stoffers, N.H.; Brandsch, R.; Bradley, E.L.; Cooper, I.; Dekker, M.; Störmer, A.; Franz, R.

    2005-01-01

    This paper describes the second part of a project whose main objective was to develop the know-how to produce certified reference materials (CRMs) for specific migration testing. Certification parameters discussed are the diffusion coefficient, DP, the respective polymer-specific coefficient, AP, of

  14. Development of a certified reference material (NMIJ CRM 7512-a) for the determination of trace elements in milk powder.

    Science.gov (United States)

    Zhu, Yanbei; Narukawa, Tomohiro; Miyashita, Shin-ichi; Kuroiwa, Takayoshi; Inagaki, Kazumi; Chiba, Koichi; Hioki, Akiharu

    2013-01-01

    A certified reference material (CRM), NMIJ CRM 7512-a, was developed for the determination of trace elements in milk powder. At least three independent analytical methods were applied to characterize the certified value of each element; all of these analytical methods were based on microwave acid digestions and carried out using different analytical instruments. The certified value was given on a dry-mass basis, where the dry-mass correction factor was obtained by drying the sample at 65°C for 15 to 25 h. The certified values in the units of mass fractions for 13 elements were as follows: Ca, 8.65 (0.38) g kg(-1); Fe, 0.104 (0.007) g kg(-1); K, 8.41 (0.33) g kg(-1); Mg, 0.819 (0.024) g kg(-1); Na, 1.87 (0.09) g kg(-1); P, 5.62 (0.23) g kg(-1); Ba, 0.449 (0.013) mg kg(-1); Cu, 4.66 (0.23) mg kg(-1); Mn, 0.931 (0.032) mg kg(-1); Mo, 0.223 (0.012) mg kg(-1); Rb, 8.93 (0.31) mg kg(-1); Sr, 5.88 (0.20) mg kg(-1); and Zn, 41.3 (1.4) mg kg(-1), where the numbers in the parentheses are the expanded uncertainties with a coverage factor of 2. The expanded uncertainties were estimated considering the contribution of the analytical methods, the method-to-method variance, the sample homogeneity, the dry-mass correction factor, and the concentrations of the standard solutions for calibration. The concentrations of As (2.1 μg kg(-1)), Cd (0.2 μg kg(-1)), Cr (1.3 μg kg(-1)), Pb (0.3 μg kg(-1)), and Y (64 μg kg(-1)) were given as information values for the present CRM.

  15. New Robust Reference Materials for In Situ Single Grain Rutile U-Pb Geochronology and Method Refinements for Detrital Rutile Analysis by LA-MC-ICP-MS

    Science.gov (United States)

    Parrish, R. R.; Bracciali, L.; Condon, D. J.; Horstwood, M. S.; Najman, Y.

    2012-12-01

    While rutile (TiO2) occurs in the heavy mineral suite of detrital sediments and originates mainly in medium- to high-grade metamorphic and some igneous rocks, there are very few applications of U-Pb dating of rutile to provenance studies; this is due to an overreliance on zircon, low U content of rutile limiting measurement quality by in situ methods, a higher proportion of common Pb relative to zircon, and a lack of widely available good quality reference materials. We have addressed these issues and characterized two ~ 1.8 Ga rutile reference materials by SEM, trace elements, U-Pb ID-TIMS, and intra-grain and inter-grain U-Pb LA-MC-ICP-MS analysis using mixed faraday and multiple ion counting detectors with high sensitivity. We have assessed U-Pb discordance and in situ variations in relative common Pb and age and their bearing on the quality of the reference materials for in situ U-Pb dating. The rutiles (Sugluk-4 and PCA-S207) come from granulite facies belts of the Canadian Shield, namely the northern Cape Smith Belt of Quebec and the Snowbird Tectonic Zone (Sasatchewan). The ID-TIMS data are slightly discordant due to variable common Pb and limited Pb loss; the variation in 6 single grains of Sugluk-4, that we use as the primary reference material, is 75% of all rutile grains in a sediment; unsuccessful analyses are due to poor quality rutiles with massive common Pb and/or U contents Horstwood M.S.A., Najman,Y., Two new rutile reference materials for in situ U-Pb LA-MC-ICP-MS dating and applications to sedimentary provenance, submitted to Chem. Geol.

  16. Metallurgical and chemical characterization of copper alloy reference materials within laser ablation inductively coupled plasma mass spectrometry: Method development for minimally-invasive analysis of ancient bronze objects

    Energy Technology Data Exchange (ETDEWEB)

    Walaszek, Damian, E-mail: damian.walaszek@empa.ch [Laboratory for Analytical Chemistry, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); University of Warsaw, Faculty of Chemistry, Pasteura 1, 02-093 Warsaw (Poland); Senn, Marianne [Laboratory for Analytical Chemistry, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Faller, Markus [Laboratory for Jointing Technology and Corrosion, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Philippe, Laetitia [Laboratory for Mechanics of Materials and Nanostructures, Swiss Federal Laboratories for Materials Science and Technology, Feuerwerkstrasse 39, CH-3602 Thun (Switzerland); Wagner, Barbara; Bulska, Ewa [University of Warsaw, Faculty of Chemistry, Pasteura 1, 02-093 Warsaw (Poland); Ulrich, Andrea [Laboratory for Analytical Chemistry, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland)

    2013-01-01

    The chemical composition of ancient metal objects provides important information for manufacturing studies and authenticity verification of ancient copper or bronze artifacts. Non- or minimal-destructive analytical methods are preferred to mitigate visible damage. Laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) enables the determination of major elements as well as impurities down to lower ppm-levels, however, accuracy and precision of analysis strongly depend on the homogeneity of reference materials used for calibration. Moreover, appropriate analytical procedures are required e.g. in terms of ablation strategies (scan mode, spot size, etc.). This study reviews available copper alloy (certified) reference materials — (C)RMs from different sources and contributes new metallurgical data on homogeneity and spatial elemental distribution. Investigations of the standards were performed by optical and scanning electron microscopy with X-ray spectrometry (SEM-EDX) for the following copper alloy and bronze (certified) reference materials: NIST 454, BAM 374, BAM 211, BAM 227, BAM 374, BAM 378, BAS 50.01-2, BAS 50.03-4, and BAS 50.04-4. Additionally, the influence of inhomogeneities on different ablation and calibration strategies is evaluated to define an optimum analytical strategy in terms of line scan versus single spot ablation, variation of spot size, selection of the most appropriate RMs or minimum number of calibration reference materials. - Highlights: ► New metallographic data for copper alloy reference materials are provided. ► Influence of RMs homogeneity on quality of LA-ICPMS analysis was evaluated. ► Ablation and calibration strategies were critically discussed. ► An LA-ICPMS method is proposed for analyzing most typical ancient copper alloys.

  17. Preparation of Reference Material of Moisture in Methanol%甲醇中微量水分标准物质的研制

    Institute of Scientific and Technical Information of China (English)

    王乐新; 许思思; 王云; 李锋丽; 黄清波; 郭波

    2015-01-01

    The reference material of moisture in methanol was prepared by using anhydrous ethanol. The uniformity and stability were tested. The testing results showed that the reference material exhibited good uniformity and stability, the value showed no significant changes in one year. The standard value was defined by the way of comparison with the national primary reference material. The standard value of reference material of moisture in methanol was 0.103%, Urel=3%(k=2). The reference material can meet the requirement of verification and calibration of Carle Fischer moisture titrators.%用无水甲醇试剂研制了甲醇中微量水分标准物质,对研制的标准物质量值进行了均匀性和稳定性检验。结果表明,该标准物质均匀性良好,其量值在一年内无显著变化,具有较好的稳定性。采用与国家一级标准物质比较法进行定值,研制的甲醇中微量水分标准物质的定值结果为0.103%,相对扩展不确定度为3%(k=2)。该标准物质满足卡尔·费休水分测定仪检定校准的要求。

  18. Evaluation of Method-Specific Extraction Variability for the Measurement of Fatty Acids in a Candidate Infant/Adult Nutritional Formula Reference Material.

    Science.gov (United States)

    Place, Benjamin J

    2017-05-01

    To address community needs, the National Institute of Standards and Technology has developed a candidate Standard Reference Material (SRM) for infant/adult nutritional formula based on milk and whey protein concentrates with isolated soy protein called SRM 1869 Infant/Adult Nutritional Formula. One major component of this candidate SRM is the fatty acid content. In this study, multiple extraction techniques were evaluated to quantify the fatty acids in this new material. Extraction methods that were based on lipid extraction followed by transesterification resulted in lower mass fraction values for all fatty acids than the values measured by methods utilizing in situ transesterification followed by fatty acid methyl ester extraction (ISTE). An ISTE method, based on the identified optimal parameters, was used to determine the fatty acid content of the new infant/adult nutritional formula reference material.

  19. Determination of the absolute 32S/34S ratio of IAEA-S-1 reference material and V-CDT sulfur isotope standard

    Institute of Scientific and Technical Information of China (English)

    丁悌平; 白瑞梅; 李延河; 万德芳; 邹晓秋; 张青莲

    1999-01-01

    The absolute 32S/34S ratios of IAEA-S-1 reference material and V-CDT standard are determined. For cross-checking, two sets of synthetic isotope mixtures are prepared from high purity 32S and 34S-enriched materials in different forms: the first set is prepared from BaSO4 whereas the second is prepared from Ag2S. The sulfur isotope analyses are done by using SF6 method with a MAT-251 EM mass spectrometer. The resulting 32S/34S ratio of IAEAS-1 reference material is 22.656 4±0. 006 0, and that of V-CDT is 22. 649 6±0. 006 0.

  20. Electrothermal atomic absorption spectrometric determination of vanadium in extracts of soil and sewage sludge certified reference materials after fractionation by means of the Communities Bureau of Reference modified sequential extraction procedure

    Science.gov (United States)

    Žemberyová, M.; Jankovič, R.; Hagarová, I.; Kuss, H.-M.

    2007-05-01

    A modified three-step sequential extraction procedure proposed by the Commission of European Communities Bureau of Reference (BCR) was applied to certified reference materials of three different soil groups (rendzina, luvisol, cambisol) and sewage sludge of different composition originating from a municipal water treatment plant in order to assess potential mobility and the distribution of vanadium in the resulting fractions. Analysis of the extracts was carried out by electrothermal atomic absorption spectrometry with Zeeman background correction using transversely heated graphite atomizers. Extracts showed significant matrix interferences which were overcome by the standard addition technique. The original soil and sludge certified reference materials (CRMs) and the extraction residue from the sequential extraction were decomposed by a mixture of HNO 3-HClO 4-HF in an open system. The content of V determined after decomposition of the samples was in very good agreement with the certified total values. The accuracy of the sequential extraction procedure was checked by comparing the sum of the vanadium contents in the three fractions and in the extraction residue with the certified total content of V. The amounts of vanadium leached were in good correlation with the certified total contents of V in the CRMs of soils and sewage sludge. In the soils examined, vanadium was present almost entirely in the mineral lattice, while in the sewage sludge samples 9-14% was found in the oxidizable and almost 25% in the reducible fractions. The recovery ranged from 93-106% and the precision (RSD) was below 10%.

  1. Extract-filter-shoot liquid chromatography with mass spectrometry for the analysis of vitamin D2 in a powdered supplement capsule and standard reference material 3280.

    Science.gov (United States)

    Byrdwell, William Craig

    2014-08-01

    An "extract-filter-shoot" method for the analysis of vitamin D2, ergocalciferol, in a dry powdered dietary supplement capsule containing rice flour excipient and in a National Institute of Standards and Technology standard reference material 3280 is reported. Quantification of vitamin D2 was done by atmospheric pressure chemical ionization mass spectrometry using selected ion monitoring, two transitions of selected reaction monitoring, and extracted ion chromatograms from full scans. UV detection was used for the quantification of Vitamin D2 in the dry powder capsule, whereas interfering species rendered UV detection unreliable for standard reference material 3280. Average values for standard reference material 3280 ranged from 8.27 ± 0.58 to 8.33 ± 0.57 μg/g using internal standard calibration and response factor approaches, compared to the previous National Institute of Standards and Technology internal value for vitamin D2 of 8.78 ± 0.11 μg/g, and the recently updated reference value of 8.6 ± 2.6 μg/g. The powdered supplement capsule was found to contain 28.19 ± 0.35 to 28.67 ± 0.90 μg/capsule for a capsule labeled to contain 25.00 μg. The triacylglycerol composition of the rice flour excipient in the powdered supplement capsule determined by atmospheric pressure chemical ionization mass spectrometry is also reported.

  2. Preparation of waterproof OSL dosimeters from hygroscopic materials with a special reference to NaCl:Cu

    Science.gov (United States)

    More, Y. K.; Wankhede, S. P.; Patil, R. R.; Kulkarni, M. S.; Kumar, Munish; Moharil, S. V.

    2016-05-01

    Optically stimulated luminescence (OSL) originally developed for geological/archaeological dating, has been found very useful for diverse applications in the field of radiation dosimetry. There is still a scarcity of OSL materials with demonstrated properties suited to dosimetry applications. Progress on the development of OSL materials with engineered properties has been slow and most research has focused on the OSL characterization of existing materials. One of the reasons for availability of only a handful of OSL dosimetry materials with adequate properties is that they have to satisfy certain stringent conditions necessary for such applications. Especially, hygroscopic materials are considered totally unsuitable. The efforts were made in our laboratory to overcome this problem. It is shown here that "water-proof" dosimeters can be prepared from even hygroscopic materials such as NaCl.

  3. USGS46 Greenland ice core water – A new isotopic reference material for δ2H and δ18O measurements of water

    Science.gov (United States)

    Coplen, Tyler B.; Qi, Haiping; Tarbox, Lauren V.; Lorenz, Jennifer M.; Buck, Bryan

    2015-01-01

    Ice core from Greenland was melted, filtered, homogenised, loaded into glass ampoules, sealed, autoclaved to eliminate biological activity, and calibrated by dual-inlet isotope-ratio mass spectrometry. This isotopic reference material (RM), USGS46, is intended as one of two secondary isotopic reference waters for daily normalisation of stable hydrogen (δ2H) and stable oxygen (δ18O) isotopic analysis of water with a mass spectrometer or a laser absorption spectrometer. The measured δ2H and δ18O values of this reference water were −235.8 ± 0.7‰ and −29.80 ± 0.03‰, respectively, relative to VSMOW on scales normalised such that the δ2H and δ18O values of SLAP reference water are, respectively, −428 and −55.5‰. Each uncertainty is an estimated expanded uncertainty (U = 2uc) about the reference value that provides an interval that has about a 95-percent probability of encompassing the true value. This reference water is available in cases containing 144 glass ampoules that are filled with either 4 ml or 5 ml of water per ampoule.

  4. Evaluation of Students' Views about the Use of SCORM (Sharable Content Object Reference Model)-Compatible Materials in Physics Teaching

    Science.gov (United States)

    Gonen, Selahattin; Basaran, Bulent

    2013-01-01

    In the present study, a web site including instructional materials such as Whiteboard Movies (WBM), simulations and animations and testing materials such as true-false, fill-in-the-blanks, puzzles, open-ended questions and multiple-choice questions was designed. The study was carried out with 76 students attending Dicle College (DC), Diyarbakir…

  5. USGS42 and USGS43: human-hair stable hydrogen and oxygen isotopic reference materials and analytical methods for forensic science and implications for published measurement results.

    Science.gov (United States)

    Coplen, Tyler B; Qi, Haiping

    2012-01-10

    Because there are no internationally distributed stable hydrogen and oxygen isotopic reference materials of human hair, the U.S. Geological Survey (USGS) has prepared two such materials, USGS42 and USGS43. These reference materials span values commonly encountered in human hair stable isotope analysis and are isotopically homogeneous at sample sizes larger than 0.2 mg. USGS42 and USGS43 human-hair isotopic reference materials are intended for calibration of δ(2)H and δ(18)O measurements of unknown human hair by quantifying (1) drift with time, (2) mass-dependent isotopic fractionation, and (3) isotope-ratio-scale contraction. While they are intended for measurements of the stable isotopes of hydrogen and oxygen, they also are suitable for measurements of the stable isotopes of carbon, nitrogen, and sulfur in human and mammalian hair. Preliminary isotopic compositions of the non-exchangeable fractions of these materials are USGS42(Tibetan hair)δ(2)H(VSMOW-SLAP) = -78.5 ± 2.3‰ (n = 62) and δ(18)O(VSMOW-SLAP) = +8.56 ± 0.10‰ (n = 18) USGS42(Indian hair)δ(2)H(VSMOW-SLAP) = -50.3 ± 2.8‰ (n = 64) and δ(18)O(VSMOW-SLAP) = +14.11 ± 0.10‰ (n = 18). Using recommended analytical protocols presented herein for δ(2)H(VSMOW-SLAP) and δ(18)O(VSMOW-SLAP) measurements, the least squares fit regression of 11 human hair reference materials is δ(2)H(VSMOW-SLAP) = 6.085δ(2)O(VSMOW-SLAP) - 136.0‰ with an R-square value of 0.95. The δ(2)H difference between the calibrated results of human hair in this investigation and a commonly accepted human-hair relationship is a remarkable 34‰. It is critical that readers pay attention to the δ(2)H(VSMOW-SLAP) and δ(18)O(VSMOW-SLAP) of isotopic reference materials in publications, and they need to adjust the δ(2)H(VSMOW-SLAP) and δ(18)O(VSMOW-SLAP) measurement results of human hair in previous publications, as needed, to ensure all results on are on the same scales.

  6. USGS42 and USGS43: Human-hair stable hydrogen and oxygen isotopic reference materials and analytical methods for forensic science and implications for published measurement results

    Science.gov (United States)

    Coplen, T.B.; Qi, H.

    2012-01-01

    Because there are no internationally distributed stable hydrogen and oxygen isotopic reference materials of human hair, the U.S. Geological Survey (USGS) has prepared two such materials, USGS42 and USGS43. These reference materials span values commonly encountered in human hair stable isotope analysis and are isotopically homogeneous at sample sizes larger than 0.2 mg. USGS42 and USGS43 human-hair isotopic reference materials are intended for calibration of δ(2)H and δ(18)O measurements of unknown human hair by quantifying (1) drift with time, (2) mass-dependent isotopic fractionation, and (3) isotope-ratio-scale contraction. While they are intended for measurements of the stable isotopes of hydrogen and oxygen, they also are suitable for measurements of the stable isotopes of carbon, nitrogen, and sulfur in human and mammalian hair. Preliminary isotopic compositions of the non-exchangeable fractions of these materials are USGS42(Tibetan hair)δ(2)H(VSMOW-SLAP) = -78.5 ± 2.3‰ (n = 62) and δ(18)O(VSMOW-SLAP) = +8.56 ± 0.10‰ (n = 18) USGS42(Indian hair)δ(2)H(VSMOW-SLAP) = -50.3 ± 2.8‰ (n = 64) and δ(18)O(VSMOW-SLAP) = +14.11 ± 0.10‰ (n = 18). Using recommended analytical protocols presented herein for δ(2)H(VSMOW-SLAP) and δ(18)O(VSMOW-SLAP) measurements, the least squares fit regression of 11 human hair reference materials is δ(2)H(VSMOW-SLAP) = 6.085δ(2)O(VSMOW-SLAP) - 136.0‰ with an R-square value of 0.95. The δ(2)H difference between the calibrated results of human hair in this investigation and a commonly accepted human-hair relationship is a remarkable 34‰. It is critical that readers pay attention to the δ(2)H(VSMOW-SLAP) and δ(18)O(VSMOW-SLAP) of isotopic reference materials in publications, and they need to adjust the δ(2)H(VSMOW-SLAP) and δ(18)O(VSMOW-SLAP) measurement results of human hair in previous publications, as needed, to ensure all results on are on the same scales.

  7. 氦同位素锂辉石标准物质的研制%Preparation and Calibration of Reference Material for Helium Isotope

    Institute of Scientific and Technical Information of China (English)

    李延河; 宋鹤彬; 乐国量

    2005-01-01

    Two spodumene samples for helium isotope standard were prepared. According to the preparation criterion on first grade national standard materials, homogeneity tests of helium contents and isotope compositions of two samples were carried out using the heat melt method. The homogeneity tests and certification analysis show that 4He contents and 3He/4He ratios of two reference material samples are homogeneous. Afterward two standard samples were distributed to four laboratories for cooperative fixed values. All data of various laboratories submit to normal distribution and not abnormity values. The average values of each laboratory are recommended as values of two spodumene samples for helium isotope standard.

  8. Protein standardization IV: Value transfer procedure for the assignment of serum protein values from a reference preparation to a target material.

    Science.gov (United States)

    Blirup-Jensen, S; Johnson, A M; Larsen, M

    2001-11-01

    A new approach for the assignment of values to serum proteins in a target material using a reference preparation has been developed. The procedure describes the general as well as the practical principles involved in the value assignment (with examples). Two models have been developed: 1) The direct value transfer between serum matrices and 2) the indirect value transfer from a pure protein preparation to a serum protein material. The necessary mathematical equations are developed and explained. The data reduction and statistical evaluation are discussed. The practical procedure (the transfer protocol) is based on six dilutions of the reference preparation assayed together with six dilutions of the target material. In this way imprecision is reduced and the proportionality of the two materials (i.e. the presence or absence of matrix effects) can be assessed directly by evaluating a single regression plot. If no matrix effects are found, the regression line will pass through zero with a slope equal to the ratio of the concentrations of the two materials. The transfer protocol is based on a multiple point value assignment obtained by several measurements a day repeated on several days, an important prerequisite being that all reconstitutions and dilutions are controlled by weighing.

  9. Development of urine standard reference materials for metabolites of organic chemicals including polycyclic aromatic hydrocarbons, phthalates, phenols, parabens, and volatile organic compounds

    Science.gov (United States)

    Schantz, Michele M.; Benner, Bruce A.; Heckert, N. Alan; Sander, Lane C.; Sharpless, Katherine E.; Vander Pol, Stacy S.; Vasquez, Y.; Villegas, M.; Wise, Stephen A.; Alwis, K. Udeni; Blount, Benjamin C.; Calafat, Antonia M.; Li, Zheng; Silva, Manori J.; Ye, Xiaoyun; Gaudreau, Éric; Patterson, Donald G.; Sjödin, Andreas

    2016-01-01

    Two new Standard Reference Materials (SRMs), SRM 3672 Organic Contaminants in Smokers’ Urine (Frozen) and SRM 3673 Organic Contaminants in Non-Smokers’ Urine (Frozen), have been developed in support of studies for assessment of human exposure to select organic environmental contaminants. Collaborations among three organizations resulted in certified values for 11 hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and reference values for 11 phthalate metabolites, 8 environmental phenols and parabens, and 24 volatile organic compound (VOC) metabolites. Reference values are also available for creatinine and the free forms of caffeine, theobromine, ibuprofen, nicotine, cotinine, and 3-hydroxycotinine. These are the first urine Certified Reference Materials characterized for metabolites of organic environmental contaminants. Noteworthy, the mass fractions of the environmental organic contaminants in the two SRMs are within the ranges reported in population survey studies such as the National Health and Nutrition Examination Survey (NHANES) and the Canadian Health Measures Survey (CHMS). These SRMs will be useful as quality control samples for ensuring compatibility of results among population survey studies and will fill a void to assess the accuracy of analytical methods used in studies monitoring human exposure to these organic environmental contaminants. PMID:25651899

  10. Development of urine standard reference materials for metabolites of organic chemicals including polycyclic aromatic hydrocarbons, phthalates, phenols, parabens, and volatile organic compounds.

    Science.gov (United States)

    Schantz, Michele M; Benner, Bruce A; Heckert, N Alan; Sander, Lane C; Sharpless, Katherine E; Vander Pol, Stacy S; Vasquez, Y; Villegas, M; Wise, Stephen A; Alwis, K Udeni; Blount, Benjamin C; Calafat, Antonia M; Li, Zheng; Silva, Manori J; Ye, Xiaoyun; Gaudreau, Éric; Patterson, Donald G; Sjödin, Andreas

    2015-04-01

    Two new Standard Reference Materials (SRMs), SRM 3672 Organic Contaminants in Smokers' Urine (Frozen) and SRM 3673 Organic Contaminants in Non-Smokers' Urine (Frozen), have been developed in support of studies for assessment of human exposure to select organic environmental contaminants. Collaborations among three organizations resulted in certified values for 11 hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and reference values for 11 phthalate metabolites, 8 environmental phenols and parabens, and 24 volatile organic compound (VOC) metabolites. Reference values are also available for creatinine and the free forms of caffeine, theobromine, ibuprofen, nicotine, cotinine, and 3-hydroxycotinine. These are the first urine Certified Reference Materials characterized for metabolites of organic environmental contaminants. Noteworthy, the mass fractions of the environmental organic contaminants in the two SRMs are within the ranges reported in population survey studies such as the National Health and Nutrition Examination Survey (NHANES) and the Canadian Health Measures Survey (CHMS). These SRMs will be useful as quality control samples for ensuring compatibility of results among population survey studies and will fill a void to assess the accuracy of analytical methods used in studies monitoring human exposure to these organic environmental contaminants.

  11. Certification of a reference material for determination of total cyanide in soil to support implementation of the International Standard ISO 11262:2011.

    Science.gov (United States)

    Scharf, Holger; Bremser, Wolfram

    2015-04-01

    Cyanides are among the most important inorganic pollutants to be tested and monitored in environmental compartments. They can be distinguished and determined as free cyanide, weak acid dissociable cyanide or as total cyanide. However, in any case obtained, measurement results are operationally defined referring to the applied analytical method. In 2011, the International Standard ISO 11262 has been published which specifies a normative analytical method for the determination of total cyanide in soil. The objective of the project described in this paper was to provide the first soil reference material (CRM) certified for its mass fraction of total cyanide on the basis of this standard. A total of 12 German laboratories with proven experience in the determination of cyanides in environmental samples participated in the certification study. Measurement results were evaluated in full compliance with the requirements of ISO Guide 35. Taking into account the results of the inter-laboratory comparison as well as the outcome of the homogeneity and stability studies, a certified mass fraction of total cyanide of 21.1 mg/kg and an expanded uncertainty (k = 2) of 1.3 mg/kg were assigned to the material. The reference material has been issued as CRM BAM-U114.

  12. Determination of catechins and caffeine in proposed green tea standard reference materials by liquid chromatography-particle beam/electron ionization mass spectrometry (LC-PB/EIMS).

    Science.gov (United States)

    Castro, Joaudimir; Pregibon, Tara; Chumanov, Kristina; Marcus, R Kenneth

    2010-10-15

    Presented here is the quantitative analysis of green tea NIST standard reference materials (SRMs) via liquid chromatography-particle beam/electron ionization mass spectrometry (LC-PB/EIMS). Three different NIST green tea standard reference materials (SRM 3254 Camellia sinesis Leaves, SRM 3255 C. sinesis Extract and SRM 3256 Green Tea-containing Oral Dosage Form) are characterized for the content of caffeine and a series of catechin species (gallic acid, catechin, epicatechin, epigallocatechin, epicatechin gallate and epigallocatechin gallate (EGCG)). The absolute limits of detection for caffeine and the catechin species were determined to be on the nanogram level. A reversed-phase chromatographic separation of the green tea reference materials was carried out on a commercial C(18) column using a gradient of water (containing 0.1% TFA) and 2:1 methanol:acetonitrile (containing 0.1%TFA) at 0.9mLmin(-1) and an analysis time of 50min. Quantification of caffeine and the catechin species was carried out using the standard addition and internal standard methods, with the latter providing appreciable improvements in precision and recovery.

  13. Simultaneous determination of theobromine, (+)-catechin, caffeine, and (-)-epicatechin in standard reference material baking chocolate 2384, cocoa, cocoa beans, and cocoa butter.

    Science.gov (United States)

    Risner, Charles H

    2008-01-01

    A reverse-phase liquid chromatography analysis is used to access the quantity of theobromine, (+)-catechin, caffeine, and (-)-epicatechin in Standard Reference Material 2384 Baking Chocolate, cocoa, cocoa beans, and cocoa butter using water or a portion of the mobile phase as the extract. The procedure requires minimal sample preparation. Theobromine, (+)-catechin, caffeine, and (-)-epicatechin are detected by UV absorption at 273 nm after separation using a 0.3% acetic acid-methanol gradient (volume fractions) and quantified using external standards. The limit of detection for theobromine, (+)-catechin, caffeine, and (-)-epicatechin averages 0.08, 0.06, 0.06, and 0.06 microg/mL, respectively. The method when applied to Standard Reference Material 2384 Baking Chocolate; baking chocolate reference material yields results that compare to two different, separate procedures. Theobromine ranges from 26000 mg/kg in cocoa to 140 mg/kg in cocoa butter; (+)-catechin from 1800 mg/kg in cocoa to below detection limits of < 32 mg/kg in cocoa butter; caffeine from 2400 mg/kg in cocoa to 400 mg/kg in cocoa butter, and (-)-epicatechin from 3200 mg/kg in cocoa to BDL, < 27 mg/kg, in cocoa butter. The mean recoveries from cocoa are 102.4 +/- 0.6% for theobromine, 100.0 +/- 0.6 for (+)-catechin, 96.2 +/- 2.1 for caffeine, and 106.2 +/- 1.7 for (-)-epicatechin.

  14. Development of an orange juice in-house reference material and its application to guarantee the quality of vitamin C determination in fruits, juices and fruit pulps.

    Science.gov (United States)

    Valente, A; Sanches-Silva, A; Albuquerque, T G; Costa, H S

    2014-07-01

    Reference materials are useful for the quality control of analytical procedures and to evaluate the performance of laboratories. There are few and expensive certified reference materials commercially available for vitamin C or ascorbic acid analysis in food matrices. In this study, the preparation and the suitability assessment of an orange juice in-house reference material (RM) for vitamin C analysis in fruits, juices and in fruit pulps is described. This RM was used for the development and full validation of an HPLC method. The results showed excellent linearity (r(2)=0.9995), good accuracy (96.6-97.3%) and precision, as relative standard deviation, ranged from 0.70% to 3.67%. The in-house RM was homogenous and stable at storage conditions (-80°C) during 12 months. According to our results, this in-house RM is an excellent tool to use in quality control and method verification purposes for vitamin C analysis of fruits, juices and fruit pulps matrices. Furthermore, a stabilization solution with perchloric and metaphosphoric acids was developed which prevents degradation of ascorbic acid for a period of 12 months at -80°C.

  15. Evaluation of reference genes for quantitative real-time PCR in oil palm elite planting materials propagated by tissue culture.

    Directory of Open Access Journals (Sweden)

    Pek-Lan Chan

    Full Text Available BACKGROUND: The somatic embryogenesis tissue culture process has been utilized to propagate high yielding oil palm. Due to the low callogenesis and embryogenesis rates, molecular studies were initiated to identify genes regulating the process, and their expression levels are usually quantified using reverse transcription quantitative real-time PCR (RT-qPCR. With the recent release of oil palm genome sequences, it is crucial to establish a proper strategy for gene analysis using RT-qPCR. Selection of the most suitable reference genes should be performed for accurate quantification of gene expression levels. RESULTS: In this study, eight candidate reference genes selected from cDNA microarray study and literature review were evaluated comprehensively across 26 tissue culture samples using RT-qPCR. These samples were collected from two tissue culture lines and media treatments, which consisted of leaf explants cultures, callus and embryoids from consecutive developmental stages. Three statistical algorithms (geNorm, NormFinder and BestKeeper confirmed that the expression stability of novel reference genes (pOP-EA01332, PD00380 and PD00569 outperformed classical housekeeping genes (GAPDH, NAD5, TUBULIN, UBIQUITIN and ACTIN. PD00380 and PD00569 were identified as the most stably expressed genes in total samples, MA2 and MA8 tissue culture lines. Their applicability to validate the expression profiles of a putative ethylene-responsive transcription factor 3-like gene demonstrated the importance of using the geometric mean of two genes for normalization. CONCLUSIONS: Systematic selection of the most stably expressed reference genes for RT-qPCR was established in oil palm tissue culture samples. PD00380 and PD00569 were selected for accurate and reliable normalization of gene expression data from RT-qPCR. These data will be valuable to the research associated with the tissue culture process. Also, the method described here will facilitate the selection

  16. Validation of MODIS cloud mask and multilayer flag using CloudSat-CALIPSO cloud profiles and a cross-reference of their cloud classifications

    Science.gov (United States)

    Wang, Tao; Fetzer, Eric J.; Wong, Sun; Kahn, Brian H.; Yue, Qing

    2016-10-01

    Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) Collection 6 cloud observations (MYD06) at 1 km are collocated with daytime CloudSat-Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) (C-C) cloud vertical structures (2B-CLDCLASS-LIDAR). For 2007-2010, over 267 million C-C cloud profiles are used to (1) validate MODIS cloud mask and cloud multilayer flag and (2) cross-reference between C-C cloud types and MODIS cloud regimes defined by joint histograms of cloud top pressure (CTP) and cloud optical depth (τ). Globally, of total observations, C-C reports 27.1% clear and 72.9% cloudy, whereas MODIS reports 30.0% confidently clear and 58.7% confidently cloudy, with the rest 7.1% as probably clear and 4.2% as probably cloudy. Agreement between MODIS and C-C is 77.8%, with 20.9% showing both clear and 56.9% showing both cloudy. The 9.1% of observations are clear in MODIS but cloudy in C-C, indicating clouds missed by MODIS; 1.8% of observations are cloudy in MODIS but clear in C-C, likely due to aerosol/dust or surface snow layers misidentified by MODIS. C-C reports 47.4/25.5% single-layer/multilayer clouds, while MODIS reports 26.7/14.0%. For C-C single-layer clouds, 90% of tropical MODIS high (CTP 23) clouds are recognized as deep convective in C-C. Approximately 70% of MODIS low-level (CTP > 680 hPa) clouds are classified as stratocumulus in C-C regardless of region and optical thickness. No systematic relationship exists between MODIS middle-level (680 < CTP < 440 hPa) clouds and C-C cloud types, largely due to different definitions adopted.

  17. Stable isotope analyses of oxygen (18O:17O:16O) and chlorine (37Cl:35Cl) in perchlorate: reference materials, calibrations, methods, and interferences

    Science.gov (United States)

    Böhlke, John Karl; Mroczkowski, Stanley J.; Sturchio, Neil C.; Heraty, Linnea J.; Richman, Kent W.; Sullivan, Donald B.; Griffith, Kris N.; Gu, Baohua; Hatzinger, Paul B.

    2017-01-01

    RationalePerchlorate (ClO4−) is a common trace constituent of water, soils, and plants; it has both natural and synthetic sources and is subject to biodegradation. The stable isotope ratios of Cl and O provide three independent quantities for ClO4− source attribution and natural attenuation studies: δ37Cl, δ18O, and δ17O (or Δ17O or 17Δ) values. Documented reference materials, calibration schemes, methods, and interferences will improve the reliability of such studies.MethodsThree large batches of KClO4 with contrasting isotopic compositions were synthesized and analyzed against VSMOW-SLAP, atmospheric O2, and international nitrate and chloride reference materials. Three analytical methods were tested for O isotopes: conversion of ClO4− to CO for continuous-flow IRMS (CO-CFIRMS), decomposition to O2 for dual-inlet IRMS (O2-DIIRMS), and decomposition to O2 with molecular-sieve trap (O2-DIIRMS+T). For Cl isotopes, KCl produced by thermal decomposition of KClO4 was reprecipitated as AgCl and converted into CH3Cl for DIIRMS.ResultsKClO4 isotopic reference materials (USGS37, USGS38, USGS39) represent a wide range of Cl and O isotopic compositions, including non-mass-dependent O isotopic variation. Isotopic fractionation and exchange can affect O isotope analyses of ClO4− depending on the decomposition method. Routine analyses can be adjusted for such effects by normalization, using reference materials prepared and analyzed as samples. Analytical errors caused by SO42−, NO3−, ReO42−, and C-bearing contaminants include isotope mixing and fractionation effects on CO and O2, plus direct interference from CO2 in the mass spectrometer. The results highlight the importance of effective purification of ClO4− from environmental samples.ConclusionsKClO4 reference materials are available for testing methods and calibrating isotopic data for ClO4− and other substances with widely varying Cl or O isotopic compositions. Current ClO4−extraction, purification

  18. Addressing Analytical Challenges of the Environmental Monitoring for the Water Framework Directive: ERM-CE100, a New Biota Certified Reference Material.

    Science.gov (United States)

    Dosis, Ioannis; Ricci, Marina; Majoros, Laszlo; Lava, Roberto; Emteborg, Håkan; Held, Andrea; Emons, Hendrik

    2017-02-21

    In the context of supporting the EU Member States in the implementation of the EU Water Framework Directive (WFD), a project for the production of a fish reference material (ERM-CE100) certified for its content of the two priority substances hexachlorobenzene (HCB) and hexachlorobutadiene (HCBD) was carried out at the Joint Research Centre (JRC) of the European Commission. The starting material was naturally contaminated Wels catfish (Silurus glanis), caught in the Ebro River (Spain). A novel approach for the processing of the fish was tested that resulted in a homogeneous and stable reference material in the form of a wet paste. The fresh-like texture of the matrix enhances the comparability of this material toward routinely analyzed environmental biota samples and facilitates its use as a quality assurance tool given that the WFD environmental quality standards (EQS) for biota are expressed as wet weight. Certified values for the mass fractions of HCB and HCBD were assigned with 120 ± 8 and 36 ± 4 μg/kg, respectively. The related interlaboratory comparison involved 13 expert laboratories applying a range of analytical methodologies. It is the first biota CRM ever available for HCBD. ERM-CE100 can be used to assess the performance of analytical methods employed in the mandatory monitoring of water bodies under the WFD, thus, providing a benchmark for establishing comparability among measurement results.

  19. Feasibility studies to establish at the Kazakhstan Ulba metallurgical plant the manufacturing capability to produce low-enriched uranium certified reference materials

    Energy Technology Data Exchange (ETDEWEB)

    Kuzminski, Jozef [Los Alamos National Laboratory; Nesuhoff, J [NBL; Cratto, P [NBL; Pfennigwerth, G [Y12 NATIONAL SEC. COMPLEX; Mikhailenko, A [ULBA METALLURGICAL PLANT; Maliutina, I [ULBA METALLURGICAL PLANT; Nations, J [GREGG PROTECTION SERVICES

    2009-01-01

    One of the salient features of the transition plan that the United States Department of Energy/National Nuclear Security Administration (DOE/NNSA) is presently implementing in the Former Soviet Union countries is the availability of uranium certified reference materials for calibration of nondestructive assay (NDA) measurement equipment. To address this challenge, DOE/NNSA and U.S. national laboratories have focused their cooperative efforts on establishing a reliable source for manufacturing, certifying, and supplying of such standards. The Ulba Metallurgical Plant (UMP), Kazakhstan, which processes large quantities of low-enriched uranium to produce ceramic fuel pellets for nuclear-powered reactors, is well situated to become a key supplier of low-enriched uranium certified reference materials for the country and Central Asia region. We have recently completed Phase I of a feasibility study to establish at UMP capabilities of manufacturing these standards. In this paper we will discuss details of a proposed methodology for uranium down-blending, material selection and characterization, and a proposed methodology of measurement by destructive (DA) and non-destructive (NDA) analysis to form a database for material certification by the competent State authorities in the Republic of Kazakhstan. In addition, we will discuss the prospect for manufacturing of such standards at UMP.

  20. A new organic reference material, L-glutamic acid, USGS41a, for δ13C and δ15N measurements − a replacement for USGS41

    Science.gov (United States)

    Qi, Haiping; Coplen, Tyler B.; Mroczkowski, Stanley J.; Brand, Willi A.; Brandes, Lauren; Geilmann, Heike; Schimmelmann, Arndt

    2016-01-01

    RationaleThe widely used l-glutamic acid isotopic reference material USGS41, enriched in both 13C and 15N, is nearly exhausted. A new material, USGS41a, has been prepared as a replacement for USGS41.MethodsUSGS41a was prepared by dissolving analytical grade l-glutamic acid enriched in 13C and 15N together with l-glutamic acid of normal isotopic composition. The δ13C and δ15N values of USGS41a were directly or indirectly normalized with the international reference materials NBS 19 calcium carbonate (δ13CVPDB = +1.95 mUr, where milliurey = 0.001 = 1 ‰), LSVEC lithium carbonate (δ13CVPDB = −46.6 mUr), and IAEA-N-1 ammonium sulfate (δ15NAir = +0.43 mUr) and USGS32 potassium nitrate (δ15N = +180 mUr exactly) by on-line combustion, continuous-flow isotope-ratio mass spectrometry, and off-line dual-inlet isotope-ratio mass spectrometry.ResultsUSGS41a is isotopically homogeneous; the reproducibility of δ13C and δ15N is better than 0.07 mUr and 0.09 mUr, respectively, in 200-μg amounts. It has a δ13C value of +36.55 mUr relative to VPDB and a δ15N value of +47.55 mUr relative to N2 in air. USGS41 was found to be hydroscopic, probably due to the presence of pyroglutamic acid. Experimental results indicate that the chemical purity of USGS41a is substantially better than that of USGS41.ConclusionsThe new isotopic reference material USGS41a can be used with USGS40 (having a δ13CVPDB value of −26.39 mUr and a δ15NAir value of −4.52 mUr) for (i) analyzing local laboratory isotopic reference materials, and (ii) quantifying drift with time, mass-dependent isotopic fractionation, and isotope-ratio-scale contraction for isotopic analysis of biological and organic materials. Published in 2016. This article is a U.S. Government work and is in the public domain in the USA.

  1. Preparation of Interference Filter Reference Materials for ELISA Analytical Instruments%酶标分析仪波长标准物质的研制

    Institute of Scientific and Technical Information of China (English)

    杨欣欣; 张彬; 荀其宁; 拓锐; 胡国星; 潘忠泉

    2015-01-01

    以硫化锌为高折射材料和冰晶石为低反射材料,利用真空镀膜技术、光学极值法检测膜厚技术镀制了窄带全介质干涉滤光片,K9玻璃为薄膜保护层,采用切割、粗磨、精磨、抛光、镀膜等光学工艺制得酶标分析仪波长标准物质,经均匀性、稳定性考核合格后,由紫外可见近红外分光光度计标准装置对标准物质定值。研制的酶标分析仪波长标准物质定制结果扩展不确定度为0.7 nm(k=2),使用方便,量值准确、稳定,技术指标满足酶标分析仪波长示值误差及重复性检定/校准工作的需要。%The interference filter reference materials were made by vacuum coating technology and optical film thickness extremum method which plating zinc sulfide as high refraction materials and cryolite as low reflective materials of narrow–band interference filter, and K9 glass was used as film protective layer. After some optical technology such as cutting, coarse grinding,fine grinding,polishing and plating, the uniformity, stability of interference filter reference materials were examinated by the ultraviolet–visible–near infrared spectrophotometer standard device. According to the results, the deterministic uncertainty of the development reference material was 0.7 nm(k=2). Therefore, the developed interference filter reference materials can meet the verification/calibration requirement for wavelength error and repeatability of ELISA analytical instruments with convenience and stable value.

  2. A new organic reference material, l-glutamic acid, USGS41a, for δ(13) C and δ(15) N measurements - a replacement for USGS41.

    Science.gov (United States)

    Qi, Haiping; Coplen, Tyler B; Mroczkowski, Stanley J; Brand, Willi A; Brandes, Lauren; Geilmann, Heike; Schimmelmann, Arndt

    2016-04-15

    The widely used l-glutamic acid isotopic reference material USGS41, enriched in both (13) C and (15) N, is nearly exhausted. A new material, USGS41a, has been prepared as a replacement for USGS41. USGS41a was prepared by dissolving analytical grade l-glutamic acid enriched in (13) C and (15) N together with l-glutamic acid of normal isotopic composition. The δ(13) C and δ(15) N values of USGS41a were directly or indirectly normalized with the international reference materials NBS 19 calcium carbonate (δ(13) CVPDB = +1.95 mUr, where milliurey = 0.001 = 1 ‰), LSVEC lithium carbonate (δ(13) CVPDB = -46.6 mUr), and IAEA-N-1 ammonium sulfate (δ(15) NAir = +0.43 mUr) and USGS32 potassium nitrate (δ(15) N = +180 mUr exactly) by on-line combustion, continuous-flow isotope-ratio mass spectrometry, and off-line dual-inlet isotope-ratio mass spectrometry. USGS41a is isotopically homogeneous; the reproducibility of δ(13) C and δ(15) N is better than 0.07 mUr and 0.09 mUr, respectively, in 200-μg amounts. It has a δ(13) C value of +36.55 mUr relative to VPDB and a δ(15) N value of +47.55 mUr relative to N2 in air. USGS41 was found to be hydroscopic, probably due to the presence of pyroglutamic acid. Experimental results indicate that the chemical purity of USGS41a is substantially better than that of USGS41. The new isotopic reference material USGS41a can be used with USGS40 (having a δ(13) CVPDB value of -26.39 mUr and a δ(15) NAir value of -4.52 mUr) for (i) analyzing local laboratory isotopic reference materials, and (ii) quantifying drift with time, mass-dependent isotopic fractionation, and isotope-ratio-scale contraction for isotopic analysis of biological and organic materials. Published in 2016. This article is a U.S. Government work and is in the public domain in the USA. Published in 2016. This article is a U.S. Government work and is in the public domain in the USA.

  3. Security classification of information

    Energy Technology Data Exchange (ETDEWEB)

    Quist, A.S.

    1989-09-01

    Certain governmental information must be classified for national security reasons. However, the national security benefits from classifying information are usually accompanied by significant costs -- those due to a citizenry not fully informed on governmental activities, the extra costs of operating classified programs and procuring classified materials (e.g., weapons), the losses to our nation when advances made in classified programs cannot be utilized in unclassified programs. The goal of a classification system should be to clearly identify that information which must be protected for national security reasons and to ensure that information not needing such protection is not classified. This document was prepared to help attain that goal. This document is the first of a planned four-volume work that comprehensively discusses the security classification of information. Volume 1 broadly describes the need for classification, the basis for classification, and the history of classification in the United States from colonial times until World War 2. Classification of information since World War 2, under Executive Orders and the Atomic Energy Acts of 1946 and 1954, is discussed in more detail, with particular emphasis on the classification of atomic energy information. Adverse impacts of classification are also described. Subsequent volumes will discuss classification principles, classification management, and the control of certain unclassified scientific and technical information. 340 refs., 6 tabs.

  4. A revision in hydrogen isotopic composition of USGS42 and USGS43 human-hair stable isotopic reference materials for forensic science.

    Science.gov (United States)

    Coplen, Tyler B; Qi, Haiping

    2016-09-01

    The hydrogen isotopic composition (δ(2)HVSMOW-SLAP) of USGS42 and USGS43 human hair stable isotopic reference materials, normalized to the VSMOW (Vienna-Standard Mean Ocean Water)-SLAP (Standard Light Antarctic Precipitation) scale, was originally determined with a high temperature conversion technique using an elemental analyzer (TC/EA) with a glassy carbon tube and glassy carbon filling and analysis by isotope-ratio mass spectrometer (IRMS). However, the TC/EA IRMS method can produce inaccurate δ(2)HVSMOW-SLAP results when analyzing nitrogen-bearing organic substances owing to the formation of hydrogen cyanide (HCN), leading to non-quantitative conversion of a sample into molecular hydrogen (H2) for IRMS analysis. A single-oven, chromium-filled, elemental analyzer (Cr-EA) coupled to an IRMS substantially improves the measurement quality and reliability of hydrogen isotopic analysis of hydrogen- and nitrogen-bearing organic material because hot chromium scavenges all reactive elements except hydrogen. USGS42 and USGS43 human hair isotopic reference materials have been analyzed with the Cr-EA IRMS method, and the δ(2)HVSMOW-SLAP values of their non-exchangeable hydrogen fractions have been revised: [Formula: see text] [Formula: see text] where mUr=0.001=‰. On average, these revised δ(2)HVSMOW-SLAP values are 5.7mUr more positive than those previously measured. It is critical that readers pay attention to the δ(2)HVSMOW-SLAP of isotopic reference materials in publications as they may need to adjust the δ(2)HVSMOW-SLAP measurement results of human hair in previous publications to ensure all results are on the same isotope-delta scale.

  5. Serum PTH reference values established by an automated third-generation assay in vitamin D-replete subjects with normal renal function: consequences of diagnosing primary hyperparathyroidism and the classification of dialysis patients.

    Science.gov (United States)

    Souberbielle, Jean-Claude; Massart, Catherine; Brailly-Tabard, Sylvie; Cormier, Catherine; Cavalier, Etienne; Delanaye, Pierre; Chanson, Philippe

    2016-03-01

    To determine parathyroid hormone (PTH) reference values in French healthy adults, taking into account serum 25-hydroxyvitamin D (25OHD), renal function, age, gender, and BMI. We studied 898 healthy subjects (432 women) aged 18-89 years with a normal BMI and estimated glomerular filtration rate (eGFR), 81 patients with surgically proven primary hyperparathyroidism (PHPT), and 264 dialysis patients. 25OHD and third-generation PTH assays were implemented on the LIAISON XL platform. Median PTH and 25OHD values in the 898 healthy subjects were 18.8  ng/l and 23.6  ng/ml respectively. PTH was lower in subjects with 25OHD ≥30  ng/ml than in those with lower values. Among the 183 subjects with 25OHD ≥30  ng/ml, those aged ≥60 years (n=31) had higher PTH values than younger subjects, independent of 25OHD, BMI, and eGFR (P<0.001). Given the small number of subjects aged ≥60 years, we adopted the 95% CI of PTH values for the entire group of 183 vitamin D-replete subjects (9.4-28.9  ng/l) as our reference values. With 28.9  ng/l as the upper limit of normal (ULN) rather than the manufacturer's ULN of 38.4  ng/l, the percentage of PHPT patients with 'high' PTH values rose to 90.1% from 66.6% (P<0.001), and 18.6% of the dialysis patients were classified differently in view of the KDIGO target range (two to nine times the ULN). When only subjects with 25OHD ≥30  ng/ml were included in the reference population, the PTH ULN fell by 22.4%, diagnostic sensitivity for PHPT improved, and the classification of dialysis patients was modified. © 2016 European Society of Endocrinology.

  6. 角膜接触镜透氧系数参考材料的研究%Reference materials for calibrating oxygen permeability in contact lenses

    Institute of Scientific and Technical Information of China (English)

    文燕; 贾晓航; 方红萍; 何涛; 齐伟明; 郑健

    2015-01-01

    Objective To find a series of reference materials that can be used to calibrate the oxygen permeability (Dk) of contact lenses using polarographic analysis.Methods A control study was performed on two different production samples to create a reference for oxygen permeability coefficients.The Dk of a rigid contact lens material was first measured by a coulometric method, then selections from samples of material were analyzed for Dk values.On the basis of the results, the selected samples were verified for use as reference material.Results For the four Boston rigid contact lens materials, the consistency of oxygen permeability met the requirements when the same production sample was chosen.The Dks, expressed as 2 times the standard deviation at a 95% confidence level, were 2.10%, 0.64%, 1.48%, and 3.16%, respectively, which conformed to the requirement of GB/T11417.7-2012 《Ophthalmic optics.Contact lenses.Part 7: Physicochemical properties test methods》.That is, the Dk reference for the material shall be known within the range of ±5%.Therefore, the average values of the oxygen permeabilities obtained from more than 6 samples can be regarded as the nominal value for a reference material.Conclusion The four Boston rigid contact lens materials (ES, EO, XO and XO2) basically meet the test requirements of oxygen permeability for the soft contact lens material available on the market.%目的 给出一套适合用于校准极谱法测量接触镜透氧系数的参考材料.方法 对照研究.通过库伦法测量硬性接触镜材料透氧系数值,并通过批材料透氧系数离散性分析,判定所选材料是否可作为参考材料.结果 Boston的ES、EO、XO和XO24种硬性接触镜材料,当选择同一生产批时,透氧系数的一致性较符合要求,在置信水平95%状况下用2倍标准差标示时,分别为2.10%、0.64%、1.48%和3.16%,符合GB/T11417.7-2012《眼科光学接触镜第7部分:理化性能试验方法》中关

  7. Physical fitness training reference manual for security force personnel at fuel cycle facilities possessing formula quantities of special nuclear materials

    Energy Technology Data Exchange (ETDEWEB)

    Arzino, P.A.; Caplan, C.S.; Goold, R.E. (California State Univ., Hayward, CA (United States). Foundation)

    1991-09-01

    The recommendations contained throughout this NUREG are being provided to the Nuclear Regulatory Commission (NRC) as a reference manual which can be used by licensee management as they develop a program plan for the safe participation of guards, Tactical Response Team members (TRTs), and all other armed response personnel in physical fitness training and in physical performance standards testing. The information provided in this NUREG will help licensees to determine if guards, TRTs, and other armed response personnel can effectively perform their normal and emergency duties without undue hazard to themselves, to fellow employees, to the plant site, and to the general public. The recommendations in this NUREG are similar in part to those contained within the Department of Energy (DOE) Medical and Fitness Implementation Guide which was published in March 1991. The guidelines contained in this NUREG are not requirements, and compliance is not required. 25 refs.

  8. USING ELASTIC WAVE VELOCITY ON CLASSIFICATION WEATHERING ROCK MATERIALS AND PREDICTION OF ENGINEERING PROPERTIES IN KURTUN GRANODIORITE

    Directory of Open Access Journals (Sweden)

    Şener CERYAN

    2007-02-01

    Full Text Available A great number of landslides occurred in weathered granites outcropped the area in which Kurtun Dams with reservoirs and Gümüshane-Giresun highways pass trough. For this, weathering effect on the rock materials of the Kurtun granodiorite was investigated. In this study, both physical and mineralogical changes on the granitic materials due to weathering are described separately using P- wave velocity in rocks materials. Mineralogical Change Parameter and Physical Parameter defined based on P- wave velocity in rocks materials are applied on the samples from the selected weathering profiles, for the estimation of the effects of weathering on the physicomechanical properties of rock materials. The relative variation of mechanical properties and these indices display a statistically significant correlation. Besides, it is shown that P wave velocity in the solid parts of the samples. and Quantitative Weathering index originally defined Ceryan (1999a as based on slake-durability index, Mineralogical Change Parameter and Physical Parameter can be used together to evaluate the effect of weathering on the mechanical behavior of rocks material from Kürtün granodiorite.

  9. Analysis of material flow of MECOM, a. s. Humenné, with reference to time, quality and quantity of processed raw material

    Directory of Open Access Journals (Sweden)

    Vaceľ Rastislav

    2001-12-01

    Full Text Available If we want that our companies meet criteria of future develepment trends of world economy, we must radically change, we can say, leave old principles of operating and management and acquire absolutely new models. Models BPR (Business Process Reengineering, that is a part of ITQM (Integrated Total Quality Management,in these tendencies are appearing to be very positive. So as to put these changes into practice, we need fully to know structure of organisation and internal progresses in organisation and management in context with external enviroment.Preparation for realization of reengineering processes requires detailed analysis of micrologistics of material flow in food processing company MECOM, a. s., Humenné too. This analysis in primary stage follows movement of basic raw material through particular departmetns of purchase, production and distribution, where it specificaly deals with these processes in looking at time, quality and quantity, based on a need to keep priority order.Logistic coordination and synchronisation of material flow, information flow and flow of finances,have an impact on company and can resolve conflict of partial targets of individual divisions which are very varied and often opposite.Entire synchronisation of these single aims isn´t possible, partial accommodation is achieveable only. The task of logistics in this company is to amend opposite partial aims, in priority order to achieve the one mutual target for all departments of company. This target presents total satisfaction of wants of consumers, achieveable by common fulfilment of performance and economical destination.

  10. Quantitative Analysis of Plutonium Content in Particles Collected from a Certified Reference Material by Total Nuclear Reaction Energy (Q Value) Spectroscopy

    Science.gov (United States)

    Croce, M. P.; Hoover, A. S.; Rabin, M. W.; Bond, E. M.; Wolfsberg, L. E.; Schmidt, D. R.; Ullom, J. N.

    2016-08-01

    Microcalorimeters with embedded radioisotopes are an emerging category of sensor with advantages over existing methods for isotopic analysis of trace-level nuclear materials. For each nuclear decay, the energy of all decay products captured by the absorber (alpha particles, gamma rays, X-rays, electrons, daughter nuclei, etc.) is measured in one pulse. For alpha-decaying isotopes, this gives a measurement of the total nuclear reaction energy (Q value) and the spectra consist of well-separated, narrow peaks. We have demonstrated a simple mechanical alloying process to create an absorber structure consisting of a gold matrix with small inclusions of a radioactive sample. This absorber structure provides an optimized energy thermalization environment, resulting in high-resolution spectra with minimal tailing. We have applied this process to the analysis of particles collected from the surface of a plutonium metal certified reference material (CRM-126A from New Brunswick Laboratory) and demonstrated isotopic analysis by microcalorimeter Q value spectroscopy. Energy resolution from the Gaussian component of a Bortels function fit was 1.3 keV FWHM at 5244 keV. The collected particles were integrated directly into the detector absorber without any chemical processing. The ^{238}Pu/^{239}Pu and ^{240}Pu/^{239}Pu mass ratios were measured and the results confirmed against the certificate of analysis for the reference material. We also demonstrated inter-element analysis capability by measuring the ^{241}Am/^{239}Pu mass ratio.

  11. Participatory Communication Referred to Meta-Design Approach through the FleXpeaker™ Application of Innovative Material in Exhibition Design

    Directory of Open Access Journals (Sweden)

    Pei-Hsuan Su

    2016-07-01

    Full Text Available Modelling a communication system in material culture today always involves with objects, people, organizations, activities and interrelationships among them. The researcher suggests bringing together stakeholders engaged to exchange ideas, which the interactions relate to multiple professions and disciplines in a participatory scope of communication system. Owing to the invention of digital media, the status quo of images and sounds has revolutionized and caused changes of the mode of art exhibitions that produce activities and aesthetic concepts in terms of numerical representation, modularity, automation, visual variability and transcoding. Underlying a participatory-design approach, the research emphasizes a co-creative meta-interpretation of museum‟s visitors. In addition, the research delves further into the use of new media-FleXpeaker™ [ITRI], as the carrier. Combining art and design with innovative technology, the research focuses on examining design objects and innovative material which are applied in new media art and exhibition, in the hope to find new angles of participatory interpretation of the “integrated innovation” in curating an exhibition.

  12. Antimony speciation analysis in sediment reference materials using high-performance liquid chromatography coupled to hydride generation atomic fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Potin-Gautier, M. [Laboratoire de Chimie Analytique, BioInorganique et Environnement LCABIE (UMR CNRS 3054), Universite de Pau et des pays de l' Adour, 64000 Pau (France); Pannier, F. [Laboratoire de Chimie Analytique, BioInorganique et Environnement LCABIE (UMR CNRS 3054), Universite de Pau et des pays de l' Adour, 64000 Pau (France)]. E-mail: Florence.pannier@univ-pau.fr; Quiroz, W. [Laboratoire de Chimie Analytique, BioInorganique et Environnement LCABIE (UMR CNRS 3054), Universite de Pau et des pays de l' Adour, 64000 Pau (France); Laboratorio de Quimica Analitica y Ambiental, Instituto de Quimica, Pontificia Universidad catolica de Valparaiso (Chile); Pinochet, H. [Laboratorio de Quimica Analitica y Ambiental, Instituto de Quimica, Pontificia Universidad catolica de Valparaiso (Chile); Gregori, I. de [Laboratorio de Quimica Analitica y Ambiental, Instituto de Quimica, Pontificia Universidad catolica de Valparaiso (Chile)

    2005-11-30

    This work presents the development of suitable methodologies for determination of the speciation of antimony in sediment reference samples. Liquid chromatography with a post-column photo-oxidation step and hydride generation atomic fluorescence spectrometry as detection system is applied to the separation and determination of Sb(III), Sb(V) and trimethylantimony species. Post-column decomposition and hydride generation steps were studied for sensitive detection with the AFS detector. This method was applied to investigate the conditions under which speciation analysis of antimony in sediment samples can be carried out. Stability studies of Sb species during the extraction processes of solid matrices, using different reagents solutions, were performed. Results demonstrate that for the extraction yield and the stability of Sb species in different marine sediment extracts, citric acid in ascorbic acid medium was the best extracting solution for antimony speciation analysis in this matrix (between 55% and 65% of total Sb was recovered from CRMs, Sb(III) being the predominant species). The developed method allows the separation of the three compounds within 6 min with detection limits of 30 ng g{sup -1} for Sb(III) and TMSbCl2 and 40 ng g{sup -1} for Sb(V) in sediment samples.

  13. Characterizing a full spectrum of physico-chemical properties of ginsenosides rb1 and rg1 to be proposed as standard reference materials.

    Science.gov (United States)

    Kim, Il-Woung; Hong, Hee-Do; Choi, Sang Yoon; Hwang, Da-Hye; Her, Youl; Kim, Si-Kwan

    2011-11-01

    Good manufacturing practice (GMP)-based quality control is an integral component of the common technical document, a formal documentation process for applying a marketing authorization holder to those countries where ginseng is classified as a medicine. In addition, authentication of the physico-chemical properties of ginsenoside reference materials, and qualitative and quantitative batch analytical data based on validated analytical procedures are prerequisites for certifying GMP. Therefore, the aim of this study was to propose an authentication process for isolated ginsenosides Rb1 and Rg1 as reference materials (RM) and for these compounds to be designated as RMs for ginseng preparations throughout the world. Ginsenoside Rb1 and Rg1 were isolated by Diaion HP-20 adsorption chromatography, silica gel flash chromatography, recrystallization, and preparative HPLC. HPLC fractions corresponding to those two ginsenosides were recrystallized in appropriate solvents for the analysis of physico-chemical properties. Documentation of the isolated ginsenosides was made according to the method proposed by Gaedcke and Steinhoff. The ginsenosides were subjected to analyses of their general characteristics, identification, purity, content quantitation, and mass balance tests. The isolated ginsenosides were proven to be a single compound when analyzed by three different HPLC systems. Also, the water content was found to be 0.940% for Rb1 and 0.485% for Rg1, meaning that the net mass balance for ginsenoside Rb1 and Rg1 were 99.060% and 99.515%, respectively. From these results, we could assess and propose a full spectrum of physicochemical properties for the ginsenosides Rb1 and Rg1 as standard reference materials for GMP-based quality control.

  14. Identification of TL-Om1, an adult T-cell leukemia (ATL) cell line, as reference material for quantitative PCR for human T-lymphotropic virus 1.

    Science.gov (United States)

    Kuramitsu, Madoka; Okuma, Kazu; Yamagishi, Makoto; Yamochi, Tadanori; Firouzi, Sanaz; Momose, Haruka; Mizukami, Takuo; Takizawa, Kazuya; Araki, Kumiko; Sugamura, Kazuo; Yamaguchi, Kazunari; Watanabe, Toshiki; Hamaguchi, Isao

    2015-02-01

    Quantitative PCR (qPCR) for human T-lymphotropic virus 1 (HTLV-1) is useful for measuring the amount of integrated HTLV-1 proviral DNA in peripheral blood mononuclear cells. Many laboratories in Japan have developed different HTLV-1 qPCR methods. However, when six independent laboratories analyzed the proviral load of the same samples, there was a 5-fold difference in their results. To standardize HTLV-1 qPCR, preparation of a well-defined reference material is needed. We analyzed the integrated HTLV-1 genome and the internal control (IC) genes of TL-Om1, a cell line derived from adult T-cell leukemia, to confirm its suitability as a reference material for HTLV-1 qPCR. Fluorescent in situ hybridization (FISH) showed that HTLV-1 provirus was monoclonally integrated in chromosome 1 at the site of 1p13 in the TL-Om1 genome. HTLV-1 proviral genome was not transferred from TL-Om1 to an uninfected T-cell line, suggesting that the HTLV-1 proviral copy number in TL-Om1 cells is stable. To determine the copy number of HTLV-1 provirus and IC genes in TL-Om1 cells, we used FISH, digital PCR, and qPCR. HTLV-1 copy numbers obtained by these three methods were similar, suggesting that their results were accurate. Also, the ratio of the copy number of HTLV-1 provirus to one of the IC genes, RNase P, was consistent for all three methods. These findings indicate that TL-Om1 cells are an appropriate reference material for HTLV-1 qPCR. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  15. Effects of the composition of standard reference material on the accuracy of determinations of {sup 210}Pb and {sup 137}Cs in soils with gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y., E-mail: yongli32@hotmail.co [State Key Laboratory of Dryland Farming and Soil Erosion in the Loess Plateau, Institute of Soil and Water Conservation, CAS and MWR, Yangling 712100 (China); Institute of Environment and Sustainable Development in Agriculture, CAAS, No. 12 Zhongguancun South Street, Beijing 100081 (China); Geng, X.C.; Yu, H.Q. [Institute of Environment and Sustainable Development in Agriculture, CAAS, No. 12 Zhongguancun South Street, Beijing 100081 (China); Wan, G.J. [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang (China)

    2011-02-15

    The effect of the composition of the used standard reference material (SRM) on results of determination of fallout radionuclides in soil samples was studied. Using five soil types as SRMs, we measured the specific activity of {sup 210}Pb and {sup 137}Cs in six target samples of Chestnut soil. It was observed that the determination of the {sup 210}Pb activity in the samples depended on the chemical composition of SRMs used to create the efficiency curves. Thus, using SRMs similar in chemical composition to the target samples should improve accuracy in the determination of {sup 210}Pb in environmental samples.

  16. DEVELOPMENT OF CERTIFIED REFERENCE MATERIALS OF HEAT RESISTING NICKEL ALLOYS FOR DETERMINATION OF DETRIMENTAL IMPURITIES AND RARE EARTH ELEMENTS BY SPECTRAL METHODS

    Directory of Open Access Journals (Sweden)

    2015-01-01

    Full Text Available Results of development and certification of reference materials of composition of heat resisting nickel alloy with the certified values of content of detrimental impurities (Zn, Cd, Pb, Tl, Bi, In, Ag, Sb, Ga, Ge, As, Se, Sn, Te, Mn, Cu, rare earth elements (Pr, Nd, Dy, Gd, Ho, Er, Nb, Sc, Y, La, Ce, and also other impurities (P, B, Fe, Si, V, Ru, Zr, Hf, Ca, Mg are given. Developed CRMs are used for calibration of optical emission spectrometers, mass-spectrometers with glow discharge and laser sampling and others.

  17. Determination of the carbon, hydrogen and nitrogen contents of alanine and their uncertainties using the certified reference material L-alanine (NMIJ CRM 6011-a).

    Science.gov (United States)

    Itoh, Nobuyasu; Sato, Ayako; Yamazaki, Taichi; Numata, Masahiko; Takatsu, Akiko

    2013-01-01

    The carbon, hydrogen, and nitrogen (CHN) contents of alanine and their uncertainties were estimated using a CHN analyzer and the certified reference material (CRM) L-alanine. The CHN contents and their uncertainties, as measured using the single-point calibration method, were 40.36 ± 0.20% for C, 7.86 ± 0.13% for H, and 15.66 ± 0.09% for N; the results obtained using the bracket calibration method were also comparable. The method described in this study is reasonable, convenient, and meets the general requirement of having uncertainties ≤ 0.4%.

  18. Characterization and Uncertainty Assessment of a Certified Reference Material of Chloramphenicol in Methanol (GBW(E)082557).

    Science.gov (United States)

    Yang, Mengrui; Wang, Min; Zhou, Jian; Song, Yinqing; Wang, Tongtong

    2016-01-01

    Prior to preparation of CRM candidate of chloramphenicol in methanol with a concentration of 100 mg/L, two independent methods including mass balance (MB) and quantitative nuclear magnetic resonance (qNMR) were employed to precisely measure the mass fraction of pure chloramphenicol materials. The mass fraction was assigned to be 99.8% with uncertainty of 0.3%. Homogeneity testing and stability study of chloramphenicol in methanol were examined by using high performance liquid chromatography. Additionally, the uncertainties originating from the process of CRM development were comprehensively evaluated. The experimental results indicate that the property value of this CRM is homogeneous and stable at 4°C for at least six months. The new CRM (GBW(E)082557) can be applicable to calibration of instrument and assurance of accuracy and comparability of results in routine measurement.

  19. Characterization and Uncertainty Assessment of a Certified Reference Material of Chloramphenicol in Methanol (GBW(E)082557)

    Science.gov (United States)

    Zhou, Jian; Song, Yinqing; Wang, Tongtong

    2016-01-01

    Prior to preparation of CRM candidate of chloramphenicol in methanol with a concentration of 100 mg/L, two independent methods including mass balance (MB) and quantitative nuclear magnetic resonance (qNMR) were employed to precisely measure the mass fraction of pure chloramphenicol materials. The mass fraction was assigned to be 99.8% with uncertainty of 0.3%. Homogeneity testing and stability study of chloramphenicol in methanol were examined by using high performance liquid chromatography. Additionally, the uncertainties originating from the process of CRM development were comprehensively evaluated. The experimental results indicate that the property value of this CRM is homogeneous and stable at 4°C for at least six months. The new CRM (GBW(E)082557) can be applicable to calibration of instrument and assurance of accuracy and comparability of results in routine measurement. PMID:27493666

  20. The Reference Materials of Preparation about Salmonella Enteritidis%肠炎沙门氏菌活菌标准物质的研制

    Institute of Scientific and Technical Information of China (English)

    柯璐; 林杰; 戴晓丽; 黄嫦娇; 黄晓蓉

    2015-01-01

    本文以肠炎沙门氏菌为选制菌种,用鸡肉糜混合保护剂配方作为活菌标准物质基质,采用冷冻真空干燥法研制活菌标准物质,共进行了3个批次的研究,每个批次分别制备100份熟制基质和100份生制基质的活菌标准物质。均匀性试验结果表明,生制基质和熟制基质的相对重复性标准差为2.185%和3.596%、相对再现性标准差为2.185%和3.514%,方差分析:P值均大于0.05,表明批次内以及批次间无显著差异。稳定性试验表明,在-20℃条件下,2种活菌标准物质稳定性良好。制备的肠炎沙门氏菌活菌标准物质具有相应的菌种特性,良好的稳定性,对研究同类型标准物质具有一定的参考价值,填补实验室检测质量控制对照物以及标准物质的空缺。%Choose Salmonella enteritidis to the target species , take Chicken mince mixed protectant formula as matrix in Living Bacterium Reference Material , adopt Lyophilization method to develop Living Bacterium Reference Material, for the study of three batches total, each batch prepared the RM containing 100 bottles of Cooked Chicken Matrix and 100 bottles of Raw Chicken Matrix.The results of the uniformity experiment showed that, the repeatability standard deviation of raw chicken matrix and cooked chicken matrix is 2.185%and 3.596%, the reproducibility standard deviation is 2.185%and 3.514%, the results of the Analysis of Variance are P>0.05, it indicated that there was no significant difference between the six batches of RM. Stability experiments showed that the RM stord at -20 ℃, the two kind of RM have good Stability. Conclusion:The Salmonella Enteritidis Living Bacterium Reference Material with corresponding strain properties, good stability, and them have great reference value to study the same type Reference Material , and fill the laboratory testing of quality control contrast and Reference Materials.

  1. Marked disequilibrium between 234Th and 230Th of the 238U natural radioactive decay chain in IAEA reference materials n. 312, 313 and 314.

    Science.gov (United States)

    Colaianni, A; D'Erasmo, G; Pantaleo, A; Schiavulli, L

    2011-02-01

    A new laboratory for the spectroscopy of natural radioactivity with a good energy resolution is presented. It consists of two distinct parts equipped, respectively, the first one with a HpGe γ-ray detector, whose setup has been already completed, and the second one with large area Silicon α-ray detectors and a radiochemical section for thin α-samples preparation, whose setup is yet in progress and will be the argument of a separate work. The γ-ray spectrometer was calibrated by means of IAEA Reference Materials n. 312, 313, 314 and 375. A large difference from the predictions of secular equilibrium emerged between the activities of (234)Th and (230)Th in Materials n. 312, 313 and 314.

  2. Marked disequilibrium between {sup 234}Th and {sup 230}Th of the {sup 238}U natural radioactive decay chain in IAEA reference materials n. 312, 313 and 314

    Energy Technology Data Exchange (ETDEWEB)

    Colaianni, A. [Dipartimento di Geologia e Geofisica dell' Universita di Bari, Via Orabona, 4 - 70125 Bari (Italy); I.N.F.N. Sezione di Bari, Via G. Amendola, 173 - 70126 Bari (Italy); D' Erasmo, G. [Dipartimento Interateneo di Fisica dell' Universita di Bari, Via G. Amendola, 173 - 70126 Bari (Italy); I.N.F.N. Sezione di Bari, Via G. Amendola, 173 - 70126 Bari (Italy); Pantaleo, A., E-mail: pantaleo@ba.infn.i [I.N.F.N. Sezione di Bari, Via G. Amendola, 173 - 70126 Bari (Italy); Schiavulli, L. [Dipartimento Interateneo di Fisica dell' Universita di Bari, Via G. Amendola, 173 - 70126 Bari (Italy); I.N.F.N. Sezione di Bari, Via G. Amendola, 173 - 70126 Bari (Italy)

    2011-02-15

    A new laboratory for the spectroscopy of natural radioactivity with a good energy resolution is presented. It consists of two distinct parts equipped, respectively, the first one with a HpGe {gamma}-ray detector, whose setup has been already completed, and the second one with large area Silicon {alpha}-ray detectors and a radiochemical section for thin {alpha}-samples preparation, whose setup is yet in progress and will be the argument of a separate work. The {gamma}-ray spectrometer was calibrated by means of IAEA Reference Materials n. 312, 313, 314 and 375. A large difference from the predictions of secular equilibrium emerged between the activities of {sup 234}Th and {sup 230}Th in Materials n. 312, 313 and 314.

  3. 自然类词项的意义与指称--基于分类学实践的考察%The Meaning and Reference of Natural Kind Term:An Investigation Based on the Practice of Classification

    Institute of Scientific and Technical Information of China (English)

    董国安

    2015-01-01

    The practice of taxonomy contains two procedures:identification and constructing classified system.The natural kind terms,such as"Panthera Tigris (tiger)",can be used to designate an object of identification,and also can be used as an expression of a category in certain system of classification.The former is designator-usage of natural kind term and the latter is concept-usage of it.Based on the differences between the two usages mentioned,some se-mantic arguments about the reference of natural kind terms can be solved more naturally.%分类学实践包含鉴定和建立分类系统两个环节,诸如虎(Panthera tigris)这样的自然类词项既可指称一个鉴定的对象,也可表示某种分类系统的一个范畴。前者是自然类词项的指示词用法,后者则是自然类词项的概念用法。基于对自然类词项两种用法的区别,可以比较自然地解决某些语义学问题。

  4. Olfactory Reference Syndrome

    Directory of Open Access Journals (Sweden)

    Alper Evrensel

    2015-12-01

    Full Text Available Olfactory reference syndrome is a delusional disorder in which the patient persistently and falsely believes that his or her body emits a foul odor. The disease is considered a variant of somatic type of delusional disorder under the diagnostic systems. Similarities between olfactory reference syndrome and obsessive compulsive disorder have also been noted. The etiopathogenesis of the disorder has not yet been clarified. Antidepressants, antipsychotics and psychotherapy are used in the treatment of this disorder. The aim of this article was to review clinical features, neurobiology, differantial diagnosis, classification problems and treatment of olfactory reference syndrome.

  5. Seri Landscape Classification and Spatial Reference

    Science.gov (United States)

    O'Meara, Carolyn

    2010-01-01

    This thesis contributes to the growing field of ethnophysiography, a new subfield of cognitive anthropology that aims to determine the universals and variation in the categorization of landscape objects across cultures. More specifically, this work looks at the case of the Seri people of Sonora, Mexico to investigate the way they categorize…

  6. Seri Landscape Classification and Spatial Reference

    Science.gov (United States)

    O'Meara, Carolyn

    2010-01-01

    This thesis contributes to the growing field of ethnophysiography, a new subfield of cognitive anthropology that aims to determine the universals and variation in the categorization of landscape objects across cultures. More specifically, this work looks at the case of the Seri people of Sonora, Mexico to investigate the way they categorize…

  7. Simultaneous determination of Si, Al and Na concentrations by particle induced gamma-ray emission and applications to reference materials and ceramic archaeological artifacts

    Science.gov (United States)

    Dasari, K. B.; Chhillar, S.; Acharya, R.; Ray, D. K.; Behera, A.; Lakshmana Das, N.; Pujari, P. K.

    2014-11-01

    A particle induced gamma ray emission (PIGE) method using 4 MeV proton beam was standardized for simultaneous determination of Si, Al and Na concentrations and has been applied for non-destructive analysis of several reference materials and archaeological clay pottery samples. Current normalized count rates of gamma-rays for the three elements listed above were obtained by an in situ method using Li as internal standard. The paper presents application of the in situ current normalized PIGE method for grouping study of 39 clay potteries, obtained from Rajasthan and Andhra Pradesh states of India. Grouping of artifacts was carried out using the ratios of SiO2 to Al2O3 concentrations, due to their non volatile nature. Powder samples and elemental standards in pellet forms (cellulose matrix) were irradiated using the 4 MeV proton beam (∼10 nA) from the 3 MV tandem accelerator at IOP Bhubaneswar, and assay of prompt gamma rays was carried out using a 60% relative efficiency HPGe detector coupled to MCA. The concentration ratio values of SiO2/Al2O3 indicated that pottery samples fell into two major groups, which are in good agreement with their collection areas. Reference materials from IAEA and NIST were analyzed for quantification of Si, Al and Na concentrations as a part of validation as well as application of PIGE method.

  8. Simultaneous determination of Si, Al and Na concentrations by particle induced gamma-ray emission and applications to reference materials and ceramic archaeological artifacts

    Energy Technology Data Exchange (ETDEWEB)

    Dasari, K.B. [Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); GITAM Institute of Science, GITAM University, Visakhapatnam 530045 (India); Chhillar, S. [Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Acharya, R., E-mail: racharya@barc.gov.in [Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Ray, D.K.; Behera, A. [Ion Beam Laboratory, Institute of Physics, Bhubaneswar 751005 (India); Lakshmana Das, N. [GITAM Institute of Science, GITAM University, Visakhapatnam 530045 (India); Pujari, P.K. [Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2014-11-15

    A particle induced gamma ray emission (PIGE) method using 4 MeV proton beam was standardized for simultaneous determination of Si, Al and Na concentrations and has been applied for non-destructive analysis of several reference materials and archaeological clay pottery samples. Current normalized count rates of gamma-rays for the three elements listed above were obtained by an in situ method using Li as internal standard. The paper presents application of the in situ current normalized PIGE method for grouping study of 39 clay potteries, obtained from Rajasthan and Andhra Pradesh states of India. Grouping of artifacts was carried out using the ratios of SiO{sub 2} to Al{sub 2}O{sub 3} concentrations, due to their non volatile nature. Powder samples and elemental standards in pellet forms (cellulose matrix) were irradiated using the 4 MeV proton beam (∼10 nA) from the 3 MV tandem accelerator at IOP Bhubaneswar, and assay of prompt gamma rays was carried out using a 60% relative efficiency HPGe detector coupled to MCA. The concentration ratio values of SiO{sub 2}/Al{sub 2}O{sub 3} indicated that pottery samples fell into two major groups, which are in good agreement with their collection areas. Reference materials from IAEA and NIST were analyzed for quantification of Si, Al and Na concentrations as a part of validation as well as application of PIGE method.

  9. Constructing criticality by classification

    DEFF Research Database (Denmark)

    Machacek, Erika

    2017-01-01

    This paper explores the role of expertise, the nature of criticality, and their relationship to securitisation as mineral raw materials are classified. It works with the construction of risk along the liberal logic of security to explore how "key materials" are turned into "critical materials......, legitimizing a criticality discourse.Specifically, the paper introduces a typology delineating the inferences made by the experts from their produced recommendations in the classification of rare earth element criticality. The paper argues that the classification is a specific process of constructing risk...

  10. Studies on the chemical conditions and microstructure in the reference bentonites of alternative buffer materials project (ABM) in Aespoe

    Energy Technology Data Exchange (ETDEWEB)

    Muurinen, A. (VTT Technical Research Centre of Finland, Espoo (Finland))

    2009-06-15

    The chemical and microstructural properties of some bentonites used in the ABM project in Aespoe HRL were studied in laboratory experiments. The aim was to obtain information about the materials before they were used in the field experiment and to test the research methods that will be used when the packages of the field experiment are retrieved. The bentonites of interest were MX-80, Deponit CAN, Asha 505 and Friedland Clay. The pH values in the compacted samples prepared from the clay powders and deionized water were about 8 for MX-80, 7 for Deponit and Asha, and 6.5 for Friedland clay. The Eh values in the compacted MX-80, Asha and Deponit samples varied between 100 mV and -100 mV, and in the Friedland clay from 0 mV to 200 mV. The total porosity, chloride porosity and the microstructure were studied in compacted samples prepared from MX-80, Deponit, Asha and Friedland Clay and equilibrated through filter plates with 0.1 M NaCl solution for 12.5 months in aerobic conditions. The dry densities of the samples were approximately 0.7, 1.0, 1.25 and 1.55 g/cm3. XRD and SAXS (Small Angle X-ray Scattering) were used to study the microstructure of the MX-80 and Deponit bentonites. It was obvious that the chloride porosity was lower than the water porosity in all the clays, which indicates the exclusion of anions caused by the negatively charged surfaces. In the XRD measurements on MX-80, Asha and Deponit, the measured basal spaces represented by the diffraction peaks were smaller than the theoretical one assuming a homogenous microstructure. This indicates that there was a substantial amount of water also in the pores, which were not seen by XRD. The SAXS data modelling which considered single discs and stacks of discs proposed that a large fraction of the clay should be considered as single platelets. The fraction of the single discs decreased with the increasing density of the sample. The number of layers in the stacks varied from 4 to 8. By combining the information

  11. Bast shoes as archaeological material: origin, classification, restoration (the case of the finds made in Sviyazhsk and Kazan

    Directory of Open Access Journals (Sweden)

    Abdullin Khalim M.

    2014-09-01

    Full Text Available The article is devoted to the study and restoration of footwear made of bast and birch bark in the 17th-19th centuries from the 2012-2013 archaeological excavations in Kazan and Sviyazhsk. Historical and archival research on the site combined with archaeological analysis allowed to clearly date each artifact. The study of archaeological footwear revealed the morphology of the items and their manufacturing technology. In order to preserve the unique finds, a system of restoration measures has been developed, which made it possible to restore the fiber structure. For conservation and restoration of the articles, a mixed methodology of processing archaeological finds made of textiles and wood has been applied. At the stage of items drying, a method that allowed retaining the form and color has been used. On the basis of analogies and the data of ethnography, it was determined that, according to the type of plaiting, the bast shoes found are characteristic of the local population, while a birch-bark unit refers to the northern (Novgorod variety, whereas a bast shoe with interwoven leather straps finds an analogy in Moscow and Yaroslavl.

  12. The classification on short message

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper discusses the importance of the classification of short message, and details some key technologies related. Through implementing a fundamental prototype, some basic models and technical references are provided.

  13. Fantasy-Driven Versus Contact-Driven Users of Child Sexual Exploitation Material: Offender Classification and Implications for Their Risk Assessment.

    Science.gov (United States)

    Merdian, Hannah L; Moghaddam, Nima; Boer, Douglas P; Wilson, Nick; Thakker, Jo; Curtis, Cate; Dawson, Dave

    2016-04-06

    Since the advent of the Internet, convictions for the possession, display, trading, and distribution of child sexual exploitation material (CSEM) have risen steadily, but little is known about their appropriate assessment and treatment, especially concerning their risk of reoffending. It has been suggested that a conceptual distinction of fantasy- versus contact-driven CSEM users might be of merit. Sixty-eight offenders recruited from sex offender treatment providers were assessed via an anonymous computer survey including a variety of clinical and risk-related variables; the findings showed differences in the psychological profiles between CSEM users and contact child sex offenders. Numerical and spatial methods of data analysis were used to identify subgroups of CSEM users; these confirmed the twofold distinction of fantasy- versus contact-driven offending. The spatial representation of participants identified three dimensions as crucial in the classification of these subgroups: direct sexual contact with a minor, possession of fantasy-generating material, and social contact with other users with a sexual interest in minors; potentially differentiating distinct offender subgroups with different risks and needs. The current study informed the development of an empirical model of CSEM users that could aid in the assessment of risk of reoffending and cross-over to contact sex offending. © The Author(s) 2016.

  14. Preparação de um material de referência certificado para controle de agrotóxicos em hortifrutigranjeiros: estudo da homogeneidade Preparation of a certified reference material for pesticide control in the cultivation of fruits and vegetables: a homogeneity study

    Directory of Open Access Journals (Sweden)

    Maria Helena Wohlers Morelli Cardoso

    2010-06-01

    Full Text Available Neste trabalho são apresentados os esforços para garantir a homogeneidade de um material de referência. Níveis residuais (mg.kg-1 de quatro agrotóxicos (γ-HCH, fenitrotiona, clorpirifós e procimidona foram adicionados à polpa de tomate com o objetivo de se preparar um material de referência certificado. As propriedades mais importantes desses materiais são a homogeneidade e a estabilidade. Antes de serem enviados a outros laboratórios, os materiais de referência precisam ter sua homogeneidade verificada. Nas etapas prévias, amostras foram avaliadas de modo a prover dados sobre o tratamento mais adequado para minimizar a variabilidade analítica do lote preparado e garantir a qualidade da amostra candidata a material de referência certificado, tão bem como a estimativa da incerteza associada à homogeneidade. A análise de variância fornece informações sobre a variabilidade do lote preparado e o grau de invariabilidade da amostra fortificada. Depois da preparação, as amostras foram expostas à radiação gama na dose de 2 kGy e submetidas a um estudo interlaboratorial para certificação. As concentrações certificadas dos agrotóxicos após caracterização foram 0,191 ± 0,047 mg.kg-1; 0,192 ± 0,068 mg.kg-1; 0,225 ± 0,076 mg.kg-1e 0,177 ± 0,051 mg.kg-1 para o γ-HCH, a fenitrotiona, clorpirifós e procimidona respectivamente.This study reports on the efforts to ensure homogeneity of certified reference materials. Residues of four pesticides (γ-HCH, fenitrothion, chlorpyrifos, and procymidone were added to tomato pulp in order to produce reference materials. The two most important properties of such materials are known to be homogeneity and stability. Before being shipped to other laboratories, reference materials must have their homogeneity certified. As part of a preliminary study, hundreds of samples were investigated in order to provide data on the most suitable treatments to minimize analytical variability and

  15. Weighted Chebyshev distance classification method for hyperspectral imaging

    Science.gov (United States)

    Demirci, S.; Erer, I.; Ersoy, O.

    2015-06-01

    The main objective of classification is to partition the surface materials into non-overlapping regions by using some decision rules. For supervised classification, the hyperspectral imagery (HSI) is compared with the reflectance spectra of the material containing similar spectral characteristic. As being a spectral similarity based classification method, prediction of different level of upper and lower spectral boundaries of all classes spectral signatures across spectral bands constitutes the basic principles of the Multi-Scale Vector Tunnel Algorithm (MS-VTA) classification algorithm. The vector tunnel (VT) scaling parameters obtained from means and standard deviations of the class references are used. In this study, MS-VT method is improved and a spectral similarity based technique referred to as Weighted Chebyshev Distance (WCD) method for the supervised classification of HSI is introduced. This is also shown to be equivalent to the use of the WCD in which the weights are chosen as an inverse power of the standard deviation per spectral band. The use of WCD measures in terms of the inverse power of standard deviations and optimization of power parameter constitute the most important side of the study. The algorithms are trained with the same kinds of training sets, and their performances are calculated for the power of the standard deviation. During these studies, various levels of the power parameters are evaluated based on the efficiency of the algorithms for choosing the best values of the weights.

  16. The application of SRF vs. RDF classification and specifications to the material flows of two mechanical-biological treatment plants of Rome: Comparison and implications.

    Science.gov (United States)

    Di Lonardo, Maria Chiara; Franzese, Maurizio; Costa, Giulia; Gavasci, Renato; Lombardi, Francesco

    2016-01-01

    This work assessed the quality in terms of solid recovered fuel (SRF) definitions of the dry light flow (until now indicated as refuse derived fuel, RDF), heavy rejects and stabilisation rejects, produced by two mechanical biological treatment plants of Rome (Italy). SRF classification and specifications were evaluated first on the basis of RDF historical characterisation methods and data and then applying the sampling and analytical methods laid down by the recently issued SRF standards. The results showed that the dry light flow presented a worst SRF class in terms of net calorific value applying the new methods compared to that obtained from RDF historical data (4 instead of 3). This lead to incompliance with end of waste criteria established by Italian legislation for SRF use as co-fuel in cement kilns and power plants. Furthermore, the metal contents of the dry light flow obtained applying SRF current methods proved to be considerably higher (although still meeting SRF specifications) compared to those resulting from historical data retrieved with RDF standard methods. These differences were not related to a decrease in the quality of the dry light flow produced in the mechanical-biological treatment plants but rather to the different sampling procedures set by the former RDF and current SRF standards. In particular, the shredding of the sample before quartering established by the latter methods ensures that also the finest waste fractions, characterised by higher moisture and metal contents, are included in the sample to be analysed, therefore affecting the composition and net calorific value of the waste. As for the reject flows, on the basis of their SRF classification and specification parameters, it was found that combined with the dry light flow they may present similar if not the same class codes as the latter alone, thus indicating that these material flows could be also treated in combustion plants instead of landfilled. In conclusion, the

  17. Repackaging and transport of PuO{sub 2} and mox reference materials: the experience at the joint research centre in Ispra

    Energy Technology Data Exchange (ETDEWEB)

    D' Alberti, F.; Lutique, S.; Maluta, F.; Mazzuccato, M. [Joint Research Centre, Via Fermi I-21020, Ispra (Italy)

    2010-07-01

    The Joint Research Centre (JRC) is a Directorate of the European Commission, distributed over sites in Belgium, Germany, Italy, the Netherlands and Spain. Its mission is to provide customer-driven scientific and technical support for the conception, development, implementation and monitoring of EU policies. Peripheral to its fundamental mission are the Decommissioning and radioactive Waste Management (D and WM) activities associated with the JRC nuclear installations constructed and operated during the early years of its research sites. Since the 1980's, the JRC evolving mission has progressively reduced the need for nuclear installations, that must now be decommissioned. The removal of nuclear material from an installation is a prerequisite to start the decommissioning. This paper reports the successful experience at the JRC Italian site (Ispra) on the preparation, packaging and transfer of Plutonium (PuO{sub 2}) and Mixed Oxides (MOX) reference materials used for over twenty years, from the Ispra Performance Laboratory (PERLA) to the original owner abroad. In particular the need for design, licensing and construction of new glove box lines and auxiliary tools as well as the safety provisions for material containers handling and transport are described. (authors)

  18. Certification of the reference material of water content in water saturated 1-octanol by Karl Fischer coulometry, Karl Fischer volumetry and quantitative nuclear magnetic resonance.

    Science.gov (United States)

    Wang, Haifeng; Ma, Kang; Zhang, Wei; Li, Jia; Sun, Guohua; Li, Hongmei

    2012-10-15

    Certified reference materials (CRMs) of water content are widely used in the calibration and validation of Karl Fischer coulometry and volumetry. In this study, the water content of the water saturated 1-octanol (WSO) CRM was certified by Karl Fischer coulometry, volumetry and quantitative nuclear magnetic resonance (Q NMR). The water content recovery by coulometry was 99.76% with a diaphragm-less electrode and Coulomat AG anolyte. The relative bias between the coulometry and volumetry results was 0.06%. In Q NMR, the water content of WSO is traceable to the International System (SI) of units through the purity of internal standard. The relative bias of water content in WSO between Q NMR and volumetry was 0.50%. The consistency of results for these three independent methods improves the accuracy of the certification of the RM. The certified water content of the WSO CRM was 4.76% with an expanded uncertainty of 0.09%.

  19. Certified reference material for the quality control of EDTA- and DTPA-extractable trace metal contents in calcareous soil (CRM 600)

    Energy Technology Data Exchange (ETDEWEB)

    Quevauviller, P. [European Commission, Standards, Measurements and Testing Programme, Brussels (Belgium); Lachica, M.; Barahona, E. [Estacion Experimental del Zaidin, Granada (Spain); Gomez, A. [Institut Nacional de Recherche Agronomique, Station d`Agronomie, Villenave d`Ornon (France); Rauret, G. [Universidad de Barcelona, Dept. de Quimica Analitica, Barcelona (Spain); Ure, A. [University of Strathclyde, Dept. of Pure and Applied Chemistry, Glasgow (United Kingdom); Muntau, H. [European Commission, Joint Research Centre, Environment Institute, Ispra (Italy)

    1998-03-01

    Single extraction tests are commonly used to study the eco-toxicity and mobility of metals in soils, e.g. to assess the bioavailable metal fraction (and thus to estimate the related phyto-toxic and nutritional deficiency effects) and the environmentally accessible trace metals upon disposal of e.g. sediment on to a soil (e.g. contamination of ground waters). However, the lack of uniformity in the different procedures does not allow the results to be compared worldwide nor the procedures to be validated. This paper describes the interlaboratory testing of EDTA- and DTPA-extraction procedures for soil analysis, followed by the preparation of a calcareous soil reference material (CRM 600), the homogeneity and stability studies and the analytical work performed for the certification of the EDTA- and DTPA- extractable contents of some trace metals (following the standardized extraction procedures). (orig.) With 2 figs., 7 tabs., 14 refs.

  20. Certified reference material for quantification of polycyclic aromatic hydrocarbons and toxic elements in tunnel dust (NMIJ CRM 7308-a) from the National Metrology Institute of Japan

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Nobuyasu; Inagaki, Kazumi; Narukawa, Tomohiro; Aoyagi, Yoshie; Narushima, Izumi; Koguchi, Masae; Numata, Masahiko [National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki (Japan)

    2011-11-15

    The National Metrology Institute of Japan has issued a certified reference material of tunnel dust for polycyclic aromatic hydrocarbons (PAHs) and toxic element analyses. PAH certification was performed using isotope dilution mass spectrometry with deuterium-labeled PAHs as internal standards. Three extraction techniques (microwave-assisted extraction with toluene/methanol, Soxhlet extraction with toluene, and pressurized liquid extraction with toluene) were used, and the extracts were measured by gas chromatography/mass spectrometry with two different columns. For values of PAHs, 11 PAHs are provided as certified values between 0.294 and 20.3 mg/kg, and five PAHs are provided as information values. Certified values of five toxic elements (Cr, Ni, Pb, Mn, and Cd) obtained from microwave-assisted digestions and a combination of measurement techniques are also provided between 43.4 and 10.71 x 10{sup 3} mg/kg. (orig.)

  1. Development of C-reactive protein certified reference material NMIJ CRM 6201-b: optimization of a hydrolysis process to improve the accuracy of amino acid analysis.

    Science.gov (United States)

    Kato, Megumi; Kinumi, Tomoya; Yoshioka, Mariko; Goto, Mari; Fujii, Shin-Ichiro; Takatsu, Akiko

    2015-04-01

    To standardize C-reactive protein (CRP) assays, the National Metrology Institute of Japan (NMIJ) has developed a C-reactive protein solution certified reference material, CRM 6201-b, which is intended for use as a primary reference material to enable the SI-traceable measurement of CRP. This study describes the development process of CRM 6201-b. As a candidate material of the CRM, recombinant human CRP solution was selected because of its higher purity and homogeneity than the purified material from human serum. Gel filtration chromatography was used to examine the homogeneity and stability of the present CRM. The total protein concentration of CRP in the present CRM was determined by amino acid analysis coupled to isotope-dilution mass spectrometry (IDMS-AAA). To improve the accuracy of IDMS-AAA, we optimized the hydrolysis process by examining the effect of parameters such as the volume of protein samples taken for hydrolysis, the procedure of sample preparation prior to the hydrolysis, hydrolysis temperature, and hydrolysis time. Under optimized conditions, we conducted two independent approaches in which the following independent hydrolysis and liquid chromatography-isotope dilution mass spectrometry (LC-IDMS) were combined: one was vapor-phase acid hydrolysis (130 °C, 24 h) and hydrophilic interaction liquid chromatography-mass spectrometry (HILIC-MS) method, and the other was microwave-assisted liquid-phase acid hydrolysis (150 °C, 3 h) and pre-column derivatization liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. The quantitative values of the two different amino acid analyses were in agreement within their uncertainties. The certified value was the weighted mean of the results of the two methods. Uncertainties from the value-assignment method, between-method variance, homogeneity, long-term stability, and short-term stability were taken into account in evaluating the uncertainty for a certified value. The certified value and the

  2. 漫透射视觉密度计密度片标准物质的研制%Preparation of Reference Material for Diffuse Transmission Visual Densitometer

    Institute of Scientific and Technical Information of China (English)

    程康; 孔炜; 邱黛君; 郭波; 张瑞锋; 仵欣

    2015-01-01

    以工业射线胶片为主材,经过曝光和暗室处理等工艺,制备检定校准漫透射视觉密度计用的密度片标准物质。密度片的级数达到24级、光学密度值范围为0.03~5.00,密度片的量值、均匀性及光谱特性等参数均优于相关规程对标准密度片的规定参数,可广泛应用于漫透射视觉密度计的检定校准工作。%By using industrial radiographic films for basic material, the reference step tablet for diffuse transmission visual densitometer was developed after the process of exposure and darkroom processing technology. The step tablet had 24 levels and the range of optical density value was 0.03–5.00. The density value,uniformity and spectral characteristics of the reference step tablet were much better than the demand parameters of related rules, which could be widely used for verification and calibration of diffuse transmission visual densitometers.

  3. Quantitative analysis of trace elements in environmental powders with laser ablation inductively coupled mass spectrometry using non-sample-corresponding reference materials for signal evaluation

    Science.gov (United States)

    Bauer, Gerald; Limbeck, Andreas

    2015-11-01

    Laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) is an attractive alternative to traditional procedures for the analysis of environmental samples (i.e., conventional liquid measurement after sample digestion). However, for accurate quantification, certified reference materials (CRM) are necessary which match the composition of the sample and include all elements of interest at the required concentration levels. The limited availability of appropriate CRMs hampers therefore substantial application. In this work, an LA-ICP-MS procedure allowing for accurate determination of trace element contents in powdered environmental samples is presented. For LA-ICP-MS analysis, the samples are mixed with an internal standard (silver oxide) and a binder (sodium tetra borate) and subsequently pressed to pellets. Quantification is accomplished using a calibration function determined using CRMs with varying matrix composition and analyte content, pre-treated and measured in the same way as the samples. With this approach, matrix-induced ablation differences resulting from varying physical/chemical properties of the individual CRMs could be compensated. Furthermore, ICP-related matrix-effects could be minimized using collision/reaction cell technology. Applicability of the procedure has been demonstrated by assessment of Cd, Cu, Ni, and Zn in four different environmental CRMs (NIST SRM1648a (urban particulate matter), NIST SRM2709 (San Joaquin Soil), BCR144 (sewage sludge), and BCR723 (road dust)). Signal evaluation was performed by alternative use of three CRMs for calculation of the calibration function whereas the remaining fourth CRM acted as unknown sample, resulting in a good agreement between measured and certified values for all elements and reference materials.

  4. Characterisation of a natural quartz crystal as a reference material for microanalytical determination of Ti, Al, Li, Fe, Mn, Ga and Ge

    Science.gov (United States)

    Audetat, Andreas; Garbe-Schonberg, Dieter; Kronz, Andreas; Pettke, Thomas; Rusk, Brian G.; Donovan, John J.; Lowers, Heather

    2015-01-01

    A natural smoky quartz crystal from Shandong province, China, was characterised by laser ablation ICP-MS, electron probe microanalysis (EPMA) and solution ICP-MS to determine the concentration of twenty-four trace and ultra trace elements. Our main focus was on Ti quantification because of the increased use of this element for titanium-in-quartz (TitaniQ) thermobarometry. Pieces of a uniform growth zone of 9 mm thickness within the quartz crystal were analysed in four different LA-ICP-MS laboratories, three EPMA laboratories and one solution-ICP-MS laboratory. The results reveal reproducible concentrations of Ti (57 ± 4 μg g-1), Al (154 ± 15 μg g-1), Li (30 ± 2 μg g-1), Fe (2.2 ± 0.3 μg g-1), Mn (0.34 ± 0.04 μg g-1), Ge (1.7 ± 0.2 μg g-1) and Ga (0.020 ± 0.002 μg g-1) and detectable, but less reproducible, concentrations of Be, B, Na, Cu, Zr, Sn and Pb. Concentrations of K, Ca, Sr, Mo, Ag, Sb, Ba and Au were below the limits of detection of all three techniques. The uncertainties on the average concentration determinations by multiple techniques and laboratories for Ti, Al, Li, Fe, Mn, Ga and Ge are low; hence, this quartz can serve as a reference material or a secondary reference material for microanalytical applications involving the quantification of trace elements in quartz.

  5. Interlaboratory comparison of two AOAC liquid chromatographic fluorescence detection methods for paralytic shellfish toxin analysis through characterization of an oyster reference material.

    Science.gov (United States)

    Turner, Andrew D; Lewis, Adam M; Rourke, Wade A; Higman, Wendy A

    2014-01-01

    An interlaboratory ring trial was designed and conducted by the Centre for Environment, Fisheries, and Aquaculture Science to investigate a range of issues affecting the analysis of a candidate Pacific oyster paralytic shellfish toxin reference material. A total of 21 laboratories participated in the study and supplied results using one or more of three instrumental methods, specifically precolumn oxidation (Pre-COX) LC with fluorescence detection (FLD; AOAC Official Method 2005.06), postcolumn oxidation (PCOX) LC-FLD (AOAC Official Method 2011.02), and hydrophilic interaction LC/MS/MS. Each participant analyzed nine replicate samples of the oyster tissue in three separate batches of three samples over a period of time longer than 1 week. Results were reported in a standardized format, reporting both individual toxin concentrations and total sample toxicity. Data were assessed to determine the equivalency of the two AOAC LC methods and the LC/MS/MS method as well as an assessment of intrabatch and interbatch repeatability and interlaboratory reproducibility of each method. Differences among the results reported using the three methods were shown to be statistically significant, although visual comparisons showed an overlap between results generated by the majority of tests, the exception being the Pre-COX quantitation of N-hydroxylated toxins in post ion-exchange fractions. Intralaboratory repeatability and interlaboratory reproducibility were acceptable for most of the results, with the exception of results generated from fractions. The results provided good evidence for the acceptable performance of the PCOX method for the quantitation of C toxins. Overall the study showed the usefulness of interlaboratory analysis for the characterization of paralytic shellfish poisoning matrix reference materials, highlighting some issues that may need to be addressed with further method assessment at individual participant laboratories.

  6. Ten Reference Materials for Available Nutrients of Agricultural Soils%10个土壤有效态成分分析标准物质研制

    Institute of Scientific and Technical Information of China (English)

    刘妹; 顾铁新; 程志中; 黄宏库; 鄢卫东; 鄢明才

    2011-01-01

    Six nutrient-doped soil samples, used as reference materials, were prepared in 1998 but have been used up in the past 10 years. They played an important role in evaluation of soil productivity and ecological geochemistry. To satisfy surveys and evaluations in multi-purpose regional geochemistry and agricultural soil productivity, a series of ten new reference materials ( GBW07412a - GBW07417a, GBW07458 - GBW07461 ) were collected from the main agricultural regions of China and prepared by the Institute of Geophysical and Geochemical Exploration (IGGE ) at in 2009. Six of the ten samples were collected from the same sites as the six samples prepared in 1998, while the others four were collected from western China and calcareous. 50 indices, including nutritious and heavy metal elements, have been certified for all ten materials. These reference materials are more comprehensive and have been more widely distributed than the materials prepared in 1998. Furthermore, to eliminate the influence of analytical method differences in some indices between agricultural and forestry departments, methods of analysis and pretreatment were comprehensively discussed and unified by 13 laboratories from Ministry of Agriculture, Ministry of Land and Resources and Chinese Academy of Sciences.%首批6个土壤有效态成分分析标准物质( GBW07412~ GBW07417),在土壤地力评价和生态农业环境地球化学评价中发挥了重要作用,经十年广泛应用,现已用尽.为满足我国覆盖区多目标地球化学调查与评价及农业土壤地力调查与评价有效态化学成分测试质量监控的需求,2009年中国地质科学院地球物理地球化学勘查研究所研制了新系列土壤有效态成分分析标准物质(GBW07412a~GBW07417a,GBW07458 ~ GBW07461).该系列10个标准物质在原有6个样品采集地重新采集的基础上,新增的4个样品侧重于西部地区和石灰性土壤,使得新研制的有效态成分分析标准物质地域

  7. Determination of metal concentrations in certified plastic reference materials after small-size autoclave and microwave-assisted digestion followed with inductively coupled plasma optical emission spectrometry

    Science.gov (United States)

    Lehtimäki, Esa; Väisänen, Ari

    2017-01-01

    The digestion methods for the determination of As, Cd, Cr, Pb, Sb, Sn and Zn concentrations in plastic samples using microwave-assisted digestion (MW-AD) and small-size autoclave digestion was developed. The certified polyethylene, polypropylene, polyvinyl chloride and acrylonitrile butadiene styrene certified reference materials were used in order to find digestion method working properly for several sample matrices. Efficiency of the digestion methods was evaluated by analyzing the residual carbon in digests by TOC analyzer. MW-AD using a mixture of 7 mL of HNO3 and 3 mL of H2O2 as a digestion solution resulted in excellent recoveries for As, Cd, Pb, Sb and Zn, and were in the range of 92-107% for all the analytes except Pb in polyethylene material. Autoclave digestion using 5 mL of concentrated HNO3 as a digestion solution resulted in similar recoveries with the exception of a higher As recovery (98%). Tin recovery resulted in low level after both MW-AD and autoclave digestion. Autoclave digestion was further developed resulting in a partially open two-step digestion process especially for the determination of Sn and Cr. The method resulted in higher recoveries of Sn and Cr (87 and 76%) but with the lower concentration of easily volatile As, Cd and Sb.

  8. 同位素稀释-ICPMS法测定地质标准物质中铂族元素%Determination of Platinum-group Elements in the Geological Standard Reference Materials by Isotope Dilution-ICPMS

    Institute of Scientific and Technical Information of China (English)

    胡明月; 何红蓼

    2005-01-01

    Platinum group elements (PGEs) includes platinum, palladium, iridium, osmium, rhodium and ruthenium. It has very high economic and scientific value in the field of geoscience and environmental science. But the analysis data referred by the different lab are very disperse because of the difficulty of the determination of PGEs. It makes very difficult to fix the value of the PGEs in the standard reference materials. In the article, the values of the PGEs in the standard reference materials of ocean sediment are determined by isotope dilution technique and dependable values of these elements are provided.

  9. Preparação de um material de referência certificado para controle de agrotóxicos em hortifrutigranjeiros: estudo da estabilidade Preparation of a certified reference material for pesticide control in the cultivation fruits and vegetables: a stability study

    Directory of Open Access Journals (Sweden)

    Maria Helena Wohlers Morelli Cardoso

    2010-06-01

    Full Text Available Neste trabalho são apresentados os resultados dos estudos de estabilidade referentes à produção de um material de referência certificado. Foram avaliados níveis residuais de concentração dos agrotóxicos γ-HCH, fenitrotiona, clorpirifós e procimidona em polpa de tomate. A pasteurização e a irradiação gama foram empregadas à polpa de tomate, visando manter a integridade da amostra candidata a material de referência. A polpa foi preparada e dividida em duas partes. Cada parte foi fortificada com os referidos agrotóxicos na faixa de concentração de 0,1 a 0,2 mg.kg-1. Uma das partes foi submetida à pasteurização a 90 °C por 4 minutos e a outra parte foi irradiada com dose de 2,0 kGy depois de homogeneizada. A estabilidade e a incerteza da amostra, correspondente ao período de tempo avaliado, foram determinadas através da análise de regressão em conjunto com a ANOVA. Os resultados indicaram que ambos os procedimentos de preparo da amostra são adequados para a conservação da polpa de tomate fortificada com os quatro agrotóxicos, com vantagem para o tratamento por irradiação com a dose de 2,0 kGy.This research presents the results of stability studies regarding the production of certified reference materials. The residual concentration levels of four pesticides, namely γ-HCH, fenitrothion, chlorpyrifos, and procymidone were investigated. Pasteurization combined with gamma irradiation was used to maintain the integrity of the mixture tested as a reference material candidate. The pulp was prepared and split into two parts. Each part was then spiked with those pesticides in the concentration range of 0.1 to 0.2 mg.kg-1 in tomato pulp. One of them was submitted to pasteurization at 90 °C for 4 minutes after being homogenized, and the other was irradiated with a gamma dose of 2.0 kGy. The material stability and the corresponding uncertainty during the period of time evaluated were determined using regression analysis and

  10. k{sub 0}-NAA quality assessment in an Algerian laboratory by analysis of SMELS and four IAEA reference materials using Es-Salam research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hamidatou, L.A., E-mail: lylia.h@hotmail.fr [Nuclear Reseach Center of Birine, P.O. Box 180 Ain Oussera, 17200 Djelfa (Algeria); Dekar, S.; Boukari, S. [Department of physics, Ferhat Abbes University, 19000 Setif (Algeria)

    2012-08-01

    Different types of synthetic multi-element standard material (SMELS) and four IAEA reference materials, 140, Sl-1, Soil-7 and Lichen-336 were analyzed for validation and QC/QA of the k{sub 0}-standardised Neutron Activation Analysis (k{sub 0}-NAA). The samples of SMELS and RMs were irradiated at Es-Salam research reactor and measured on an absolutely calibrated HPGe detector with 35% relative efficiency connected to a Canberra Genie 2k inspector. Concentrations of 33 elements such as As, Au, Ba, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, In, K, La, Mn, Mo, Na, Nd, Rb, Sb, Sc, Se, Sm, Sr, Ta, Tb, Th, Tm, U, Yb, Zn, and Zr were determined in SMELS and RMs. The analytical results agreed well with the assigned values of SMELS and certified values of RMs. In the case of RMs, concentrations of a few elements, whose certified values are not available, could be determined. The comparison between experimental values and assigned/certified data for SMELS and RMs was made by means of the results from Relative Bias, Z-score and U-score. The relatives bias of the elements determined in SMELS with respect to the assigned values were all within{+-}4.6%. For RMs with respect to certified values were within{+-}10% except for few elements for which RB varied from -28.6% to +12.8%. The Z-score values at 95% confidence level for most of the elements in both the materials were within {+-}1. The U-scores for most of the elements were lower than 1.

  11. Cosmetics Europe compilation of historical serious eye damage/eye irritation in vivo data analysed by drivers of classification to support the selection of chemicals for development and evaluation of alternative methods/strategies: the Draize eye test Reference Database (DRD).

    Science.gov (United States)

    Barroso, João; Pfannenbecker, Uwe; Adriaens, Els; Alépée, Nathalie; Cluzel, Magalie; De Smedt, Ann; Hibatallah, Jalila; Klaric, Martina; Mewes, Karsten R; Millet, Marion; Templier, Marie; McNamee, Pauline

    2017-02-01

    A thorough understanding of which of the effects assessed in the in vivo Draize eye test are responsible for driving UN GHS/EU CLP classification is critical for an adequate selection of chemicals to be used in the development and/or evaluation of alternative methods/strategies and for properly assessing their predictive capacity and limitations. For this reason, Cosmetics Europe has compiled a database of Draize data (Draize eye test Reference Database, DRD) from external lists that were created to support past validation activities. This database contains 681 independent in vivo studies on 634 individual chemicals representing a wide range of chemical classes. A description of all the ocular effects observed in vivo, i.e. degree of severity and persistence of corneal opacity (CO), iritis, and/or conjunctiva effects, was added for each individual study in the database, and the studies were categorised according to their UN GHS/EU CLP classification and the main effect driving the classification. An evaluation of the various in vivo drivers of classification compiled in the database was performed to establish which of these are most important from a regulatory point of view. These analyses established that the most important drivers for Cat 1 Classification are (1) CO mean ≥ 3 (days 1-3) (severity) and (2) CO persistence on day 21 in the absence of severity, and those for Cat 2 classification are (3) CO mean ≥ 1 and (4) conjunctival redness mean ≥ 2. Moreover, it is shown that all classifiable effects (including persistence and CO = 4) should be present in ≥60 % of the animals to drive a classification. As a consequence, our analyses suggest the need for a critical revision of the UN GHS/EU CLP decision criteria for the Cat 1 classification of chemicals. Finally, a number of key criteria are identified that should be taken into consideration when selecting reference chemicals for the development, evaluation and/or validation of alternative methods and

  12. Classification of anthropogenic soils by new diagnostic criteria involved in the Slovak Soil Classification System (2014)

    Science.gov (United States)

    Sobocká, Jaroslava; Balkovič, Juraj; Bedrna, Zoltán

    2017-04-01

    Anthropogenic soils can be found mostly in SUITMA areas. The issue of adequate and correct description and classification of these soils occurs very often and can result in inconsistent even in contradictory opinions. In the new version of the anthropogenic soil classification system in Slovakia some new diagnostics criteria were involved and applied for better understanding the inherent nature of these soils. The group of the former anthropogenic soils was divided following scheme of soil reference groups in the WRB 2014 (Anthrozem and Technozem). According to the new version of the Slovak anthropogenic soils classification (2014) there have been distinguished 2 groups of anthropogenic soils: 1) cultivated soils group including 2 soil types (in Slovak terminology): Kultizem and Hortizem and 2) technogenic soils group having 2 soil types: Antrozem and Technozem. Cultivated soil group represents soils developing or forming "in-situ" with diagnostic horizons characterized by human deeply influenced cultivated processes. Technogenic soil group are soils developing like "ex-situ" soils. The key features recognizing technogenic soil group are human-transported and altered material (HTAM = ex-situ aspect), and artefacts content. Diagnostic horizons (top and subsoil) were described as various material affected by physical-mechanical excavation, transportation and spread, mixing, and containing artefacts (the new diagnostic feature). Kultizems are differentiated by cultivated horizon(s) and Technozems by anthropogenic horizon(s). Cultivated horizons are mostly well-known described horizon in many scientific references. Anthropogenic horizons for Technozem are developed from the human-induced transported and altered material which origin is from the other ecological locality that adjacent area. Materials (or substrates) can consist of various material (natural, technogenic or their mixing) with thickness ≥ 60 cm. Artefacts are the second diagnostic feature which presence

  13. Growth references

    NARCIS (Netherlands)

    Buuren, S. van

    2007-01-01

    A growth reference describes the variation of an anthropometric measurement within a group of individuals. A reference is a tool for grouping and analyzing data and provides a common basis for comparing populations.1 A well known type of reference is the age-conditional growth diagram. The

  14. Road Classification and Condition Determination Using Hyperspectral Imagery

    Science.gov (United States)

    Mohammadi, M.

    2012-07-01

    Hyperspectral data has remarkable capabilities for automatic identification and mapping of urban surface materials because of its high spectral resolution. It includes a wealth of information which facilitates an understanding of the ground material properties. For identification of road surface materials, information about their relation to hyperspectral sensor measurements is needed. In this study an approach for classification of road surface materials using hyperspectral data is developed. The condition of the road surface materials, in particular asphalt is also investigated. Hyperspectral data with 4m spatial resolution of the city of Ludwigsburg, Germany consisting of 125 bands (wavelength range of 0.4542μm to 2.4846 μm) is used. Different supervised classification methods such as spectral angle mapper are applied based on a spectral library established from field measurements and in-situ inspection. It is observed that using the spectral angle mapper approach with regions of interest is helpful for road surface material identification. Additionally, spectral features are tested using their spectral functions in order to achieve better classification results. Spectral functions such as mean and standard deviation are suitable for discriminating asphalt, concrete and gravel. Different asphalt conditions (good, intermediate and bad) are distinguished using the spectral functions such as mean and image ratio. The mean function gives reliable results. Automatisierte Liegenschaftskarte (ALK) vector data for roads is integrated in order to confine the analysis to roads. Reliable reference spectra are useful in evaluation of classification results for spectrally similar road surface materials. The classification results are assessed using orthophotos and field visits information.

  15. Hydrothermal titanite from the Chengchao iron skarn deposit: temporal constraints on iron mineralization, and its potential as a reference material for titanite U-Pb dating

    Science.gov (United States)

    Hu, Hao; Li, Jian-Wei; McFarlane, Christopher R. M.

    2017-09-01

    Uranium-lead isotopes and trace elements of titanite from the Chengchao iron skarn deposit (Daye district, Eastern China), located along the contact zones between Triassic marine carbonates and an early Cretaceous intrusive complex consisting of granite and quartz diorite, were analyzed using laser ablation inductively coupled plasma mass spectrometry to provide temporal constraints on iron mineralization and to evaluate its potential as a reference material for titanite U-Pb geochronology. Titanite grains from mineralized endoskarn have simple growth zoning patterns, exhibit intergrowth with magnetite, diopside, K-feldspar, albite and actinolite, and typically contain abundant primary two-phase fluid inclusions. These paragenetic and textural features suggest that these titanite grains are of hydrothermal origin. Hydrothermal titanite is distinct from the magmatic variety from the ore-related granitic intrusion in that it contains unusually high concentrations of U (up to 2995 ppm), low levels of Th (12.5-453 ppm), and virtually no common Pb. The REE concentrations are much lower, as are the Th/U and Lu/Hf ratios. The hydrothermal titanite grains yield reproducible uncorrected U-Pb ages ranging from 129.7 ± 0.7 to 132.1 ± 2.7 Ma (2σ), with a weighted mean of 131.2 ± 0.2 Ma [mean standard weighted deviation (MSWD) = 1.7] that is interpreted as the timing of iron skarn mineralization. This age closely corresponds to the zircon U-Pb age of 130.9 ± 0.7 Ma (MSWD = 0.7) determined for the quartz diorite, and the U-Pb ages for zircon and titanite (130.1 ± 1.0 Ma and 131.3 ± 0.3 Ma) in the granite, confirming a close temporal and likely genetic relationship between granitic magmatism and iron mineralization. Different hydrothermal titanite grains have virtually identical uncorrected U-Pb ratios suggestive of negligible common Pb in the mineral. The homogeneous textures and U-Pb characteristics of Chengchao hydrothermal titanite suggest that the mineral might be a

  16. Development of SI-traceable C-peptide certified reference material NMIJ CRM 6901-a using isotope-dilution mass spectrometry-based amino acid analyses.

    Science.gov (United States)

    Kinumi, Tomoya; Goto, Mari; Eyama, Sakae; Kato, Megumi; Kasama, Takeshi; Takatsu, Akiko

    2012-07-01

    A certified reference material (CRM) is a higher-order calibration material used to enable a traceable analysis. This paper describes the development of a C-peptide CRM (NMIJ CRM 6901-a) by the National Metrology Institute of Japan using two independent methods for amino acid analysis based on isotope-dilution mass spectrometry. C-peptide is a 31-mer peptide that is utilized for the evaluation of β-cell function in the pancreas in clinical testing. This CRM is a lyophilized synthetic peptide having the human C-peptide sequence, and contains deamidated and pyroglutamylated forms of C-peptide. By adding water (1.00 ± 0.01) g into the vial containing the CRM, the C-peptide solution in 10 mM phosphate buffer saline (pH 6.6) is reconstituted. We assigned two certified values that represent the concentrations of total C-peptide (mixture of C-peptide, deamidated C-peptide, and pyroglutamylated C-peptide) and C-peptide. The certified concentration of total C-peptide was determined by two amino acid analyses using pre-column derivatization liquid chromatography-mass spectrometry and hydrophilic chromatography-mass spectrometry following acid hydrolysis. The certified concentration of C-peptide was determined by multiplying the concentration of total C-peptide by the ratio of the relative area of C-peptide to that of the total C-peptide measured by liquid chromatography. The certified value of C-peptide (80.7 ± 5.0) mg/L represents the concentration of the specific entity of C-peptide; on the other hand, the certified value of total C-peptide, (81.7 ± 5.1) mg/L can be used for analyses that does not differentiate deamidated and pyroglutamylated C-peptide from C-peptide itself, such as amino acid analyses and immunochemical assays.

  17. Seismic texture classification. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Vinther, R.

    1997-12-31

    The seismic texture classification method, is a seismic attribute that can both recognize the general reflectivity styles and locate variations from these. The seismic texture classification performs a statistic analysis for the seismic section (or volume) aiming at describing the reflectivity. Based on a set of reference reflectivities the seismic textures are classified. The result of the seismic texture classification is a display of seismic texture categories showing both the styles of reflectivity from the reference set and interpolations and extrapolations from these. The display is interpreted as statistical variations in the seismic data. The seismic texture classification is applied to seismic sections and volumes from the Danish North Sea representing both horizontal stratifications and salt diapers. The attribute succeeded in recognizing both general structure of successions and variations from these. Also, the seismic texture classification is not only able to display variations in prospective areas (1-7 sec. TWT) but can also be applied to deep seismic sections. The seismic texture classification is tested on a deep reflection seismic section (13-18 sec. TWT) from the Baltic Sea. Applied to this section the seismic texture classification succeeded in locating the Moho, which could not be located using conventional interpretation tools. The seismic texture classification is a seismic attribute which can display general reflectivity styles and deviations from these and enhance variations not found by conventional interpretation tools. (LN)

  18. A simplified classification system for partially edentulous spaces

    Directory of Open Access Journals (Sweden)

    Bhandari Aruna J, Bhandari Akshay J

    2014-04-01

    Full Text Available Background: There is no single universally employed classification system that will specify the exact edentulous situation. Several classification systems exist to group the situation and avoid confusion. Classifications based on edentulous areas, finished restored prostheses, type of direct retainers or fulcrum lines are there. Some are based depending on the placement of the implants. Widely accepted Kennedy Applegate classification does not give any idea about length, span or number of teeth missing. Rule 6 governing the application of Kennedy method states that additional edentulous areas are referred as modification number 1,2 etc. Rule 7 states that extent of the modification is not considered; only the number of edentulous areas is considered. Hence there is a need to modify the Kennedy –Applegate System. Aims: This new classification system is an attempt to modify Kennedy –Applegate System so as to give the exact idea about missing teeth, space, span, side and areas of partially edentulous arches. Methods and Material: This system will provide the information regarding Maxillary or Mandibular partially edentulous arches, Left or Right side, length of the edentulous space, number of teeth missing and whether there will be tooth borne or tooth – tissue borne prosthesis. Conclusions: This classification is easy for application, communication and will also help to design the removable cast partial denture in a better logical and systematic way. Also, this system will give the idea of the edentulous status and the number of missing teeth in fixed, hybrid or implant prosthesis.

  19. Concurrent determination of 237Np and Pu isotopes using ICP-MS: analysis of NIST environmental matrix standard reference materials 4357, 1646a, and 2702.

    Science.gov (United States)

    Matteson, Brent S; Hanson, Susan K; Miller, Jeffrey L; Oldham, Warren J

    2015-04-01

    An optimized method was developed to analyze environmental soil and sediment samples for (237)Np, (239)Pu, and (240)Pu by ICP-MS using a (242)Pu isotope dilution standard. The high yield, short time frame required for analysis, and the commercial availability of the (242)Pu tracer are significant advantages of the method. Control experiments designed to assess method uncertainty, including variation in inter-element fractionation that occurs during the purification protocol, suggest that the overall precision for measurements of (237)Np is typically on the order of ± 5%. Measurements of the (237)Np concentration in a Peruvian Soil blank (NIST SRM 4355) spiked with a known concentration of (237)Np tracer confirmed the accuracy of the method, agreeing well with the expected value. The method has been used to determine neptunium and plutonium concentrations in several environmental matrix standard reference materials available from NIST: SRM 4357 (Radioactivity Standard), SRM 1646a (Estuarine Sediment) and SRM 2702 (Inorganics in Marine Sediment).

  20. Development of PVC and PP resin pellet certified reference materials for heavy metal analysis with respect to the RoHS directive.

    Science.gov (United States)

    Ohata, Masaki; Hioki, Akiharu

    2013-01-01

    The PVC (polyvinyl chloride) and the PP (polypropylene) resin pellet certified reference materials (CRMs, NMIJ CRM 8123-a and 8133-a) with respect to the RoHS (restriction of the use of hazardous substances in electrical and electronics equipment) directive were developed in the present study. Both the sample pretreatment and the measurement procedures for the determination of Cd, Cr, Hg and Pb in the PVC and the PP resin pellets were examined, and several analytical methods were developed. Microwave acid digestion and dry-ashing followed by acid digestion procedures were examined as sample pretreatment procedures. In the case of measurement procedures, an inductively coupled plasma mass spectrometry (ICPMS) including an isotope dilution mass spectrometry (IDMS) and an ICP optical emission spectrometry (ICPOES) were used. Since the analytical results obtained by different analytical methods showed good agreement within their uncertainties estimated, it was concluded that the analytical methods established in this study were reliable with high accuracy. The homogeneity and the stability of Cd, Cr, Hg and Pb in these plastic CRMs were also evaluated, and the results revealed sufficient homogeneity of 0.3-0.7% and stability for more than 5 years. From these results, it is considered that these CRMs are useful CRM for the determination of Cd, Cr, Hg and Pb in plastics with respect to the RoHS directive.

  1. Estimation of mercury speciation in soil standard reference materials with different extraction methods by ion chromatography coupled with ICP-MS.

    Science.gov (United States)

    Park, Misun; Yoon, Hyeon; Yoon, Cheolho; Yu, Jae-Young

    2011-01-01

    Analytical methods for the speciation of mercury, based on microwave extraction and sonication extraction, have been tested to determine the inorganic mercury and methyl mercury contents in two standard soil reference materials: SRM 2710 Montana Soil and BCR 580 estuarine sediment. Prior to applying the speciation extraction methods, the mineral compositions were analyzed via XRD analysis, with SRM 2710 shown to be composed mostly of aluminum silicate minerals, while carbonate minerals were the major constituent in BCR 580. Two extraction methods, microwave and sonication, were tested for the analysis and recovery efficiency of total mercury. The accuracy and efficiency of each extraction method was also compared. In the analysis of total mercury, the microwave extraction method, with using methanol and HCl as extractants, was better for SRM2710, while the application of the sonication extraction method was more efficient for the calcite-based BCR 580. The results showed good separation and recovery efficiencies, with values reaching 100% of those estimated. The sonication method was selected for the speciation of mercury, especially in BCR 580. An extraction solution comprising of a 1:1 mixture of methanol and HCl was used for the sonication extraction of BCR 580, with the resulting extractants analyzed by IC-HG-ICP-MS for methyl mercury and inorganic mercury. As a simple, rapid, sensitive, and accurate method, sonication extraction was found to be satisfactory.

  2. Organomercury determination in biological reference materials: application to a study on mercury speciation in marine mammals off the Faröe Islands.

    Science.gov (United States)

    Schintu, M; Jean-Caurant, F; Amiard, J C

    1992-08-01

    The potential use of graphite furnace atomic absorption spectrometry (GF-AAS) for the organic mercury determination in marine biological tissues was evaluated. Following its isolation by acid extraction in toluene, organic mercury was recovered in aqueous thiosulfate and measured by GF-AAS. The detection limit was 0.01 microgram Hg/g (as methyl mercury). Analyses were conducted on three reference standard materials certified for their methyl mercury content, DOLT-1, DORM-1, and TORT-1, provided by the National Research Council of Canada. The method resulted in very good recovery and reproducibility, indicating that GF-AAS can provide results comparable to those obtained by using more expensive and time consuming analytical techniques. The method was applied to the analysis of liver tissues of pilot whale specimens (Globicephala melas) from the drive fishery of the Faröe Islands (northeast Atlantic). The results provided useful information on the proportion of different mercury forms in the liver of these marine mammals.

  3. Certified Reference Material for Use in (1)H, (31)P, and (19)F Quantitative NMR, Ensuring Traceability to the International System of Units.

    Science.gov (United States)

    Rigger, Romana; Rück, Alexander; Hellriegel, Christine; Sauermoser, Robert; Morf, Fabienne; Breitruck, KathrinBreitruck; Obkircher, Markus

    2017-09-01

    In recent years, quantitative NMR (qNMR) spectroscopy has become one of the most important tools for content determination of organic substances and quantitative evaluation of impurities. Using Certified Reference Materials (CRMs) as internal or external standards, the extensively used qNMR method can be applied for purity determination, including unbroken traceability to the International System of Units (SI). The implementation of qNMR toward new application fields, e.g., metabolomics, environmental analysis, and physiological pathway studies, brings along more complex molecules and systems, thus making use of 1H qNMR challenging. A smart workaround is possible by the use of other NMR active nuclei, namely 31P and 19F. This article presents the development of three classes of qNMR CRMs based on different NMR active nuclei (1H, 31P, and 19F), and the corresponding approaches to establish traceability to the SI through primary CRMs from the National Institute of Standards and Technology and the National Metrology Institute of Japan. These TraceCERT® qNMR CRMs are produced under ISO/IEC 17025 and ISO Guide 34 using high-performance qNMR.

  4. Microwave-assisted versus conventional decomposition procedures applied to a ceramic potsherd standard reference material by inductively coupled plasma atomic emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Papadopoulou, D.N.; Zachariadis, G.A.; Anthemidis, A.N.; Tsirliganis, N.C.; Stratis, J.A

    2004-03-03

    Inductively coupled plasma atomic emission spectrometry (ICP-AES) is a powerful, sensitive analytical technique with numerous applications in chemical characterization including that of ancient pottery, mainly due to its multi-element character, and the relatively short time required for the analysis. A critical step in characterization studies of ancient pottery is the selection of a suitable decomposition procedure for the ceramic matrix. The current work presents the results of a comparative study of six decomposition procedures applied on a standard ceramic potsherd reference material, SARM 69. The investigated decomposition procedures included three microwave-assisted decomposition procedures, one wet decomposition (WD) procedure by conventional heating, one combined microwave-assisted and conventional heating WD procedure, and one fusion procedure. Chemical analysis was carried out by ICP-AES. Five major (Si, Al, Fe, Ca, Mg), three minor (Mn, Ba, Ti) and two trace (Cu, Co) elements were determined and compared with their certified values. Quantitation was performed at two different spectral lines for each element and multi-element matrix-matched calibration standards were used. The recovery values for the six decomposition procedures ranged between 75 and 110% with a few notable exceptions. Data were processed statistically in order to evaluate the investigated decomposition procedures in terms of recovery, accuracy and precision, and eventually select the most appropriate one for ancient pottery analysis.

  5. Development of a certified reference material (NMIJ CRM 7531-a) for the determination of trace cadmium and other elements in brown rice flour.

    Science.gov (United States)

    Miyashita, Shin-ichi; Inagaki, Kazumi; Narukawa, Tomohiro; Zhu, Yanbei; Kuroiwa, Takayoshi; Hioki, Akiharu; Chiba, Koichi

    2012-01-01

    A certified reference material (CRM) for trace cadmium and other elements in brown rice flour was developed at the National Metrology Institute of Japan (NMIJ). The CRM was provided as a dry powder after drying and frozen pulverization of fresh brown rice obtained from a Japanese domestic market. Characterization of the property value for each element was carried out exclusively by NMIJ with at least two independent analytical methods, including inductively coupled plasma mass spectrometry (ICP-MS), ICP high-resolution mass spectrometry, isotope-dilution ICP-MS, ICP optical emission spectrometry, and graphite-furnace atomic-absorption spectrometry. Property values were provided for six elements (Mn, Fe, Cu, Zn, As, and Cd). The concentration range of the property values was from 0.280 mg kg(-1) of As to 31.8 mg kg(-1) of Zn. The combined relative standard uncertainties of the property values were estimated by considering the uncertainties of the homogeneity, characterization, difference among analytical methods, dry-mass correction factor, and calibration standard. The range of the relative combined standard uncertainties was from 1.1% of Zn to 1.6% of As.

  6. A certified urea reference material (NMIJ CRM 6006-a) as a reliable calibrant for the elemental analyses of amino acids and food samples.

    Science.gov (United States)

    Itoh, Nobuyasu; Yamazaki, Taichi; Sato, Ayako; Numata, Masahiko; Takatsu, Akiko

    2014-01-01

    We examined the reliability of a certified reference material (CRM) for urea (NMIJ CRM 6006-a) as a calibrant for N, C, and H in elemental analyzers. Only the N content for this CRM is provided as an indicative value. To estimate the C and H contents of the urea CRM, we took into account the purity of the urea and the presence of other identified impurities. When we examined the use of various masses of the calibrant (0.2 to 2 mg), we unexpectedly observed low signal intensities for small masses of H and N, but these plateaued at about 2 mg. We therefore analyzed four amino acid CRMs and four food CRMs on a 2-mg scale with the urea CRM as the calibrant. For the amino acid CRMs, the differences in the analytical and theoretical contents (≤0.0026 kg/kg) were acceptable with good repeatability (≤0.0013 kg/kg in standard deviation; n = 4). For food CRMs, comparable repeatabilities to those obtained with amino acid CRMs (≤0.0025 kg/kg in standard deviation; n = 4) were obtained. The urea CRM can therefore be used as a reliable calibrant for C, H, and N in an elemental analyzer.

  7. Certification of methylmercury content in two fresh-frozen reference materials: SRM 1947 Lake Michigan fish tissue and SRM 1974b organics in mussel tissue (Mytilus edulis)

    Energy Technology Data Exchange (ETDEWEB)

    Davis, W.C.; Christopher, S.J.; Pugh, Rebecca S. [National Institute of Standards and Technology (NIST), Hollings Marine Laboratory, Analytical Chemistry Division, Charleston, SC (United States); Donard, O.F.X.; Krupp, Eva A. [LCABIE/CNRS Helioparc Pau-Pyrenees, Pau (France); Point, David [National Institute of Standards and Technology (NIST), Hollings Marine Laboratory, Analytical Chemistry Division, Charleston, SC (United States); LCABIE/CNRS Helioparc Pau-Pyrenees, Pau (France); Horvat, Milena; Gibicar, D. [Jozef Stefan Institute, Ljubljana (Slovenia); Kljakovic-Gaspic, Z. [Jozef Stefan Institute, Ljubljana (Slovenia); Institute for Medical Research and Occupational Health, Zagreb (Croatia); Porter, Barbara J.; Schantz, Michele M. [National Institute of Standards and Technology (NIST), Analytical Chemistry Division, Gaithersburg, MD (United States)

    2007-04-15

    This paper describes the development of two independent analytical methods for the extraction and quantification of methylmercury from marine biota. The procedures involve microwave extraction, followed by derivatization and either headspace solid-phase microextraction (SPME) with a polydimethylsiloxane (PDMS)-coated silica fiber or back-extraction into iso-octane. The identification and quantification of the extracted compounds is carried out by capillary gas chromatography/mass spectrometric (GC/MS) and inductively coupled plasma mass spectrometric (GC/ICP-MS) detection. Both methods were validated for the determination of methylmercury (MeHg) concentrations in a variety of biological standard reference materials (SRMs) including fresh-frozen tissue homogenates of SRM 1946 Lake Superior fish tissue and SRM 1974a organics in mussel tissue (Mytilus edulis) and then applied to the certification effort of SRM 1947 Lake Michigan fish tissue and SRM 1974b organics in mussel tissue (Mytilus edulis). While past certifications of methylmercury in tissue SRMs have been based on two independent methods from the National Institute of Standards and Technology (NIST) and participating laboratories, the methods described within provide improved protocols and will allow future certification efforts to be based on at least two independent analytical methods within NIST. (orig.)

  8. Biomedical Engineering Desk Reference

    CERN Document Server

    Ratner, Buddy D; Schoen, Frederick J; Lemons, Jack E; Dyro, Joseph; Martinsen, Orjan G; Kyle, Richard; Preim, Bernhard; Bartz, Dirk; Grimnes, Sverre; Vallero, Daniel; Semmlow, John; Murray, W Bosseau; Perez, Reinaldo; Bankman, Isaac; Dunn, Stanley; Ikada, Yoshito; Moghe, Prabhas V; Constantinides, Alkis

    2009-01-01

    A one-stop Desk Reference, for Biomedical Engineers involved in the ever expanding and very fast moving area; this is a book that will not gather dust on the shelf. It brings together the essential professional reference content from leading international contributors in the biomedical engineering field. Material covers a broad range of topics including: Biomechanics and Biomaterials; Tissue Engineering; and Biosignal Processing* A hard-working desk reference providing all the essential material needed by biomedical and clinical engineers on a day-to-day basis * Fundamentals, key techniques,

  9. References on Sustainable Buildings

    OpenAIRE

    2005-01-01

    This web site is developed with the aim to promote sustainable design and planning of buildings. Selected references including books, reports, audio/visual materials and journals are listed. Most of the materials can be found in the HKU Libraries. To facilitate retrieval, links are provided to the library catalogue system for further information and study.

  10. On the use of certified reference materials for assuring the quality of results for the determination of mercury in environmental samples.

    Science.gov (United States)

    Bulska, Ewa; Krata, Agnieszka; Kałabun, Mateusz; Wojciechowski, Marcin

    2017-03-01

    This work focused on the development and validation of methodologies for the accurate determination of mercury in environmental samples and its further application for the preparation and certification of new reference materials (RMs). Two certified RMs ERM-CC580 (inorganic matrix) and ERM-CE464 (organic matrix) were used for the evaluation of digestion conditions assuring the quantitative recovery of mercury. These conditions were then used for the digestion of new candidates for the environmental RMs: bottom sediment (M_2 BotSed), herring tissue (M_3 HerTis), cormorant tissue (M_4 CormTis), and codfish muscle (M_5 CodTis). Cold vapor atomic absorption spectrometry (CV AAS) and inductively coupled plasma mass spectrometry (ICP MS) were used for the measurement of mercury concentration in all RMs. In order to validate and assure the accuracy of results, isotope dilution mass spectrometry (IDMS) was applied as a primary method of measurement, assuring the traceability of obtained values to the SI units: the mole, the kilogram, and the second. Results obtained by IDMS using n((200)Hg)/n((202)Hg) ratio, with estimated combined uncertainty, were as follows: (916 ± 41)/[4.5 %] ng g(-1) (M_2 BotSed), (236 ± 14)/[5.9 %] ng g(-1) (M_3 HerTis), (2252 ± 54)/[2.4 %] ng g(-1) (M_4 CormTis), and (303 ± 15)/[4.9 %] ng g(-1) (M_CodTis), respectively. Different types of detection techniques and quantification (external calibration, standard addition, isotope dilution) were applied in order to improve the quality of the analytical results. The good agreement (within less than 2.5 %) between obtained results and those derived from the Inter-laboratory Comparison, executed by the Institute of Nuclear Chemistry and Technology (Warsaw, Poland) on the same sample matrices, further validated the analytical procedures developed in this study, as well as the concentration of mercury in all four new RMs. Although the developed protocol enabling the metrological

  11. [Definition and classification of epilepsy].

    Science.gov (United States)

    Jibiki, Itsuki

    2014-05-01

    The concept or definition of epilepsy was mentioned as a chronic disease of the brain consisting of repetitions of EEG paroxysm and clinical seizures caused by excessive discharges of the cerebral neurons, in reference with Gastaut's opinion and the other statements. Further, we referred to diseases to be excluded from epilepsy such as isolated, occasional and subclinical seizures and so on. Next, new classifications of seizures and epilepsies were explained on the basis of revised terminology and concepts for organization of seizures and epilepsies in Report of the ILAE Communication in Classification and Terminology, 2005-09, in comparison with the Classification of Epileptic Seizures in 1981 and the Classification of Epilepsies and Epileptic Syndromes in 1989.

  12. Bosniak Classification system

    DEFF Research Database (Denmark)

    Graumann, Ole; Osther, Susanne Sloth; Karstoft, Jens;

    2014-01-01

    . Purpose: To investigate the inter- and intra-observer agreement among experienced uroradiologists when categorizing complex renal cysts according to the Bosniak classification. Material and Methods: The original categories of 100 cystic renal masses were chosen as “Gold Standard” (GS), established...... to the calculated weighted κ all readers performed “very good” for both inter-observer and intra-observer variation. Most variation was seen in cysts catagorized as Bosniak II, IIF, and III. These results show that radiologists who evaluate complex renal cysts routinely may apply the Bosniak classification...

  13. 转基因玉米质粒分子国家标准样品的构建%Research on Molecular DNA Reference Material for GM Maize

    Institute of Scientific and Technical Information of China (English)

    郑秋月; 曹际娟; 徐君怡; 赵昕

    2012-01-01

    本文研制转基因玉米常见的4个品系:BT11、MON810、NK603和T25质粒分子国家标准样品.研究重点包括目标序列和内标准基因序列的选择和扩增、标准样品定值和分析等.均匀性和稳定性结果表明,所研制的转基因玉米4个品系标准样品均匀稳定.采用PicoGreen DNA分子荧光定量方法定值标准样品.多家单位合作定值,确定标准样品的标准值及其不确定度.所研制的转基因玉米质粒分子标准样品获得了国家标准样品证书,适用于转基因产品的定量和定性测定.%We devoloped the research of GM Maize BT1U MON810, NK603 and T25 Line Molecular DNA Reference Material. Research priorities include the target sequence and the internal standard gene sequences selection and amplification, reference Material definite value and analysis. The result of uniformity and stability test showed that the Reference Materials were uniformity and stability. The value of Reference Material was difinited by PicoGreen DNA fluorescence quantitative method. The standard value and uncertainty of Reference Material was difinited by many units cooperation.The Molecular DNA Reference Material with certificate has the important value on the quantitative and qualitative detection of GMO.

  14. Reference Revolutions.

    Science.gov (United States)

    Mason, Marilyn Gell

    1998-01-01

    Describes developments in Online Computer Library Center (OCLC) electronic reference services. Presents a background on networked cataloging and the initial implementation of reference services by OCLC. Discusses the introduction of OCLC FirstSearch service, which today offers access to over 65 databases, future developments in integrated…

  15. 肠侵袭性大肠埃希氏菌国家核酸标准样品的研制%Development of Enteroinvasive Escherichia coli nucleic acid reference material

    Institute of Scientific and Technical Information of China (English)

    那晗; 倪长鹏; 刘宇; 吴远高; 徐君怡; 郑秋月

    2015-01-01

    目的:研制肠侵袭性大肠埃希氏菌核酸标准样品,并对其均匀性和稳定性进行评价。方法本文研究了肠侵袭性大肠埃希氏菌核酸标准样品的关键制备技术和保存技术,定值技术和定值方式,开展均匀性和稳定性试验,并对食品中肠侵袭性大肠埃希氏菌核酸标准样品的不确定度进行确定;标准样品采用 PicoGreen DNA 分子荧光定量方法进行定值。多家单位合作定值,确定标准样品的标准值及其不确定度。结果标准样品均匀性标准不确定度为0.016%,不稳定标准差为0.0100,均匀性和稳定性试验结果表明,本文研制的标准样品均匀且稳定。结论研制出具有溯源性的肠侵袭性大肠埃希氏菌核酸标准样品并获得国家标准样品证书,可适用于肠侵袭性大肠埃希氏菌的检测和质量控制。%Objective Enteroinvasive Escherichia Coli(EIEC) Molecular DNA Reference Material was developed, and uniformity and stability of test were evaluated. Methods The key preparation technology, saving technology, certified technique and mode for EIEC Molecular DNA Reference Material were researched, via uniformity and stability test. The uncertainty for EIEC Molecular DNA Reference Material was evaluated in food. The standard value was determined by PicoGreen DNA molecule fluorescence quantitative methods. Standard and uncertainty of reference material was determined by many units cooperation. Results Uniformity standard uncertainty of reference material was 0.016 %, unstable standard deviation was 0.0100. The result of uniformity and stability test showed that reference material developed in this study was uniform and stable. Conclusion EIEC Molecular DNA Reference Material with the traceability was developed, and certificate of national reference material was obtained. It could be used for quantitative detection and qualitative quality control of EIEC.

  16. 多接收电感耦合等离子体质谱法测定Nd同位素标准物质%Nd Isotopic Measurements of Reference Materials Using Multicollector-Inductively Coupled Plasma Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    唐索寒; 何学贤; 王进辉; 朱祥坤

    2005-01-01

    The precision and accuracy of Nd isotope analysis using multicollector-inductively coupled plasma mass spectrometry (MC-ICPMS) is verified through repeated measurements of standard reference materials of JMC Nd2O3 and GBW04419. A mixed solution of Nd separated from hundreds of geological samples is measured for 143Nd/144Nd ratio, which produces excellent long-term repeatability. This solution, named as CAGS-Nd-1, can be used as an in-house reference material for monitoring instrument stability during Nd isotope measurements.

  17. 17 CFR 200.505 - Original classification.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Original classification. 200...; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Classification and Declassification of National Security Information and Material § 200.505 Original classification. (a) No Commission Member or employee has...

  18. 17 CFR 200.506 - Derivative classification.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Derivative classification. 200...; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Classification and Declassification of National Security Information and Material § 200.506 Derivative classification. Any document that includes...

  19. Increasing the Accuracy in the Measurement of the Minor Isotopes of Uranium: Care in Selection of Reference Materials, Baselines and Detector Calibration

    Science.gov (United States)

    Poths, J.; Koepf, A.; Boulyga, S. F.

    2008-12-01

    The minor isotopes of uranium (U-233, U-234, U-236) are increasingly useful for tracing a variety of processes: movement of anthropogenic nuclides in the environment (ref 1), sources of uranium ores (ref 2), and nuclear material attribution (ref 3). We report on improved accuracy for U-234/238 and U-236/238 by supplementing total evaporation protocol TIMS measurement on Faraday detectors (ref 4)with multiplier measurement for the minor isotopes. Measurement of small signals on Faraday detectors alone is limited by noise floors of the amplifiers and accurate measurement of the baseline offsets. The combined detector approach improves the reproducibility to better than ±1% (relative) for the U-234/238 at natural abundance, and yields a detection limit for U-236/U-238 of <0.2 ppm. We have quantified contribution of different factors to the uncertainties associated with these peak jumping measurement on a single detector, with an aim of further improvement. The uncertainties in the certified values for U-234 and U-236 in the uranium standard NBS U005, if used for mass bias correction, dominates the uncertainty in their isotopic ratio measurements. Software limitations in baseline measurement drives the detection limit for the U-236/U-238 ratio. This is a topic for discussion with the instrument manufacturers. Finally, deviation from linearity of the response of the electron multiplier with count rate limits the accuracy and reproducibility of these minor isotope measurements. References: (1) P. Steier et al(2008) Nuc Inst Meth(B), 266, 2246-2250. (2) E. Keegan et al (2008) Appl Geochem 23, 765-777. (3) K. Mayer et al (1998) IAEA-CN-98/11, in Advances in Destructive and Non-destructive Analysis for Environmental Monitoring and Nuclear Forensics. (4) S. Richter and S. Goldberg(2003) Int J Mass Spectrom, 229, 181-197.

  20. Reference characterisation of sound speed and attenuation of the IEC