WorldWideScience

Sample records for biological reference materials

  1. The preparation of biological reference materials for QUASIMEME

    NARCIS (Netherlands)

    Kotterman, M.J.J.

    2011-01-01

    Biological materials, consisting of three different batches of mussels; from Den Helder harbour (POPs, TBT), Irish mussels (metals) and Wadden Sea mussels, fortified with highly contaminated mussels from Belgium (POPs), and of one batch of turbot liver (metals) have been prepared for use in QUASIMEM

  2. 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.

  3. Biological reference materials from the National Institute for Environmental Studies (Japan)

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, Kensaku

    1988-12-01

    The National Institute for Environmental Studies has recently undertaken the development of two new biological reference materials, Sargasso and Rice Flour-Unpolished, for trace element analysis. The sargasso seaweed (Sargassum felvellum) reference material contains high levels of alkali, alkaline earth elements and As, together with low concentrations of heavy metals. The rice flour-unpolished reference material was prepared from unpolished rice collected from three different locations in Japan. This reference material consists of three samples, each containing different levels (low, medium, high) of Cd. This paper presents the preparation and elemental composition of NIES Sargasso and Rice Flour-Unpolished reference materials, following a brief description of each of the currently available NIES certified reference materials.

  4. Reference Materials

    Science.gov (United States)

    Merkus, Henk G.

    Reference materials for measurement of particle size and porosity may be used for calibration or qualification of instruments or for validation of operating procedures or operators. They cover a broad range of materials. On the one hand there are the certified reference materials, for which governmental institutes have certified one or more typical size or porosity values. Then, there is a large group of reference materials from commercial companies. And on the other hand there are typical products in a given line of industry, where size or porosity values come from the analysis laboratory itself or from some round-robin test in a group of industrial laboratories. Their regular application is essential for adequate quality control of particle size and porosity measurement, as required in e.g., ISO 17025 on quality management. In relation to this, some quality requirements for certification are presented.

  5. Biological and environmental reference materials for trace elements, nuclides and organic microcontaminants

    International Nuclear Information System (INIS)

    This report has been produced from a database on analytical reference materials of biological and environmental origin, which is maintained at the International Atomic Energy Agency. It is an updated version of an earlier report, published in 1985, which focussed mainly on reference materials for trace elements. In the present version of the report, reference materials for trace elements still constitute the major part of the data; however, information is also now included on a number of other selected analytes of relevance to IAEA programmes, i.e. radionuclides, stable isotopes and organic microcontaminants. The database presently contains 2,694 analyte values for 117 analytes in 116 biological and 77 environmental (non-biological) reference materials produced by 20 different suppliers. Additional information on the cost of the material, the unit size supplied, (weight or volume), and the minimum weight of material recommended for analysis is also provided (if available to the authors). It is expected that this report will help analysts to select the reference material that matches as closely as possible, with respect to matrix type and concentrations of the analytes of interest, the ''real'' samples that are to be analysed. Refs, 12 tabs

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

    Science.gov (United States)

    Forti, Tatiana; Souto, Aline da S S; do Nascimento, Carlos Roberto S; Nishikawa, Marilia M; Hubner, Marise T W; Sabagh, Fernanda P; Temporal, Rosane Maria; Rodrigues, Janaína M; da Silva, Manuela

    2016-01-01

    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. PMID:26991280

  8. 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.

  9. Biological reference materials for quality control of elemental composition analytical data

    International Nuclear Information System (INIS)

    Twelve biological-matrix, agricultural/food reference materials, Corn Stalk (Zea Mays) (NIST RM 8412), Corn Kernel (Zea Mays) (NIST RM 8413), Bovine Muscle Powder (NIST RM 8414), Whole Egg Powder (NIST RM 8415), Microcrystalline Cellulose (NIST RM 8416), Wheat Gluten (NIST RM 8418), Corn Starch (NIST RM 8432), Corn Bran (NIST RM 8433), Whole Milk Powder (NIST RM 8435), Durum Wheat Flour (NIST RM 8436), Hard Red Spring Wheat Flour (NIST RM 8437) and Soft Winter Wheat Flour (NIST RM 8438) were developed. They were characterized with respect to elemental composition via two extensive international interlaboratory characterization campaigns providing 303 reference and informational concentration values for 34 elements (Al, As, B, Ba, Br, Ca, Cd, Cl, Co, Cr, Cs, Cu, F, Fe, Hg, I, K, Mg, Mn, Mo, N, Na, Ni, P, Pb, Rb, S, Sb, Se, Sr, Ti, V, W, Zn) of nutritional, toxicological, and environmental significance. These products are available to the analytical community, for quality control of elemental composition analytical data, from the Standard Reference Materials Program, National Institute of Standards and Technology, Gaithersburg, MD, USA. (author)

  10. 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

  11. 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

  12. Preparation of three biological reference material for QUASIMEME inter-laboratory testing

    NARCIS (Netherlands)

    Lohman, M.; Korytar, P.

    2006-01-01

    Three biological materials have been prepared for IVM, Free University, Amsterdam to be used in QUASIMEME interlaboratory studies. The materials prepared are: 300 glass jars of homogenized Mediterranean mussels (QM06-1), 280 tins of homogenized blue mussels from German Bight (QM06-3) and 300 tins of

  13. Elemental analysis of biological materials. Current problems and techniques with special reference to trace elements

    International Nuclear Information System (INIS)

    Selected techniques were reviewed for the assay of trace and minor elements in biological materials. Other relevant information is also presented on the need for such analyses, sampling, sample preparation and analytical quality control. In order to evaluate and compare the applicability of the various analytical techniques on a meaningful and objective basis, the materials chosen for consideration were intended to be typical of a wide range of biological matrics of different elemental compositions, namely Bowen's kale, representing a plant material, and NBS bovine liver, IAEA animal muscle, and blood serum, representing animal tissues. The subject is reviewed under the following headings: on the need for trace element analyses in the life sciences (4 papers); sampling and sample preparation for trace element analysis (2 papers); analytical techniques for trace and minor elements in biological materials (7 papers); analytical quality control (2 papers)

  14. Compilation of elemental concentration data for NBS Biological and Environmental Standard Reference Materials

    International Nuclear Information System (INIS)

    Concentration data on up to 76 elementals in 19 NBS Standard Reference Materials have been collected from 325 journal articles and technical reports. These data are summarized into mean +- one standard deviation values and compared with available data from NBS and other review articles. Data are presented on the analytical procedures employed and all raw data are presented in appendixes

  15. Homogeneity study on biological candidate reference materials: the role of neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Daniel P.; Moreira, Edson G., E-mail: dsilva.pereira@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Instrumental Neutron activation Analysis (INAA) is a mature nuclear analytical technique able to accurately determine chemical elements without the need of sample digestion and, hence, without the associated problems of analyte loss or contamination. This feature, along with its potentiality use as a primary method of analysis, makes it an important tool for the characterization of new references materials and in the assessment of their homogeneity status. In this study, the ability of the comparative method of INAA for the within-bottle homogeneity of K, Mg, Mn and V in a mussel reference material was investigated. Method parameters, such as irradiation time, sample decay time and distance from sample to the detector were varied in order to allow element determination in subsamples of different sample masses in duplicate. Sample masses were in the range of 1 to 250 mg and the limitations of the detection limit for small sample masses and dead time distortions for large sample masses were investigated. (author)

  16. Determination of copper, molybdenum and selenium in biological reference materials by inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    In a contribution to the elemental characterization of 10 new reference materials, Bovine Muscle Powder (136), Corn Starch (162), Hard Red Spring Wheat Flour (165), Soft Winter Wheat Flour (166), Whole Milk Powder (183), Wheat Gluten (184), Corn Bran (186). Durum Wheat Flour (187), Whole Egg Powder (188) and Microcrystalline Cellulose (189), the total concentrations of Cu, Mo and Se were determined by the application of an analytical method based on isotope dilution inductively coupled plasma mass spectrometry. Cu and Mo contents were quantified by measurement of 65Cu/63Cu and 97Mo/100Mo isotopic ratios following spiking with 65Cu and 97Mo and digestion with nitric acid. Selenium was separated as hydrogen selenide from the matrix using sodium borohydride after spiking with 82Se and acid digestion-dry ashing and quantified by measurement of the 82Se/78Se isotopic ratio. Comparison of these results with those from a variety of other methods and assessment of the procedures using certified reference materials indicated that the determinations of Cu, Mo and Se were performed without analytical bias. (orig.)

  17. Survey of currently available reference materials for use in connection with the determination of trace elements in biological and environmental materials

    International Nuclear Information System (INIS)

    This report focuses on analytical reference materials which have been developed for use in connection with the determination of toxic and essential trace elements in biomedical and health-related environmental samples. Data are reported on 60 biological and 40 environmental (non-biological) reference materials from 11 suppliers. Certified concentration values (or their equivalents) and non-certified concentration values (or information values) are presented in various tables which are intended to help the user select a reference material that matches as closely as possible (i.e. with respect to matrix type and concentration of the element of interest) the ''real'' samples that are to be analysed. These tables have been generated from a database characterized by the following parameters: total number of reference materials=100; total number of elements recorded=69; total number of concentration values recorded=1771. Also included in the report is information (where available) on the cost of each material, the unit weight or volume supplied, and the minimum weight of material recommended for analysis. (author)

  18. Survey of reference materials. V. 2: Environmentally related reference materials for trace elements, nuclides and microcontaminants

    International Nuclear Information System (INIS)

    The present report presently contains over 250 reference materials with trace element and organic contaminant information on fuel, geological and mineral, anthropogenic disposal, soil reference and miscellaneous reference materials. Not included in the current report is information on most biological and environmental reference materials with trace element, stable isotope, radioisotope and organic contaminant information. 8 refs, tabs

  19. Development of a candidate reference material for adventitious virus detection in vaccine and biologicals manufacturing by deep sequencing

    OpenAIRE

    Edward T Mee; Preston, Mark D.; Minor, Philip D.; ,; Huang, Xuening; Nguyen, Jenny; Wall, David; Hargrove, Stacey; Fu, Thomas; Xu, George; Li, Li; Cote, Colette; Delwart, Eric; Li, Linlin; Hewlett, Indira

    2016-01-01

    Background Unbiased deep sequencing offers the potential for improved adventitious virus screening in vaccines and biotherapeutics. Successful implementation of such assays will require appropriate control materials to confirm assay performance and sensitivity. Methods A common reference material containing 25 target viruses was produced and 16 laboratories were invited to process it using their preferred adventitious virus detection assay. Results Fifteen laboratories returned results, obtai...

  20. Multiscale Biological Materials

    DEFF Research Database (Denmark)

    Frølich, Simon

    2016-01-01

    Materials formed by organisms, also known as biological materials, exhibit outstanding structural properties. The range of materials formed in nature is remarkable and their functions include support, protection, motion, sensing, storage, and maintenance of physiological homeostasis. These complex...... materials are characterized by their hierarchical and composite design, where features with sizes ranging from nanometers to centimeters provide the basis for the functionality of the material. Understanding of biological materials is, while very interesting from a basic research perspective, also valuable...... as inspiration for the development of new materials for medical and technological applications. In order to successfully mimic biological materials we must first have a thorough understanding of their design. As such, the purpose of the characterization of biological materials can be defined as the establishment...

  1. Nuclear measurements and reference materials

    International Nuclear Information System (INIS)

    This report summarizes the progress of the JRC programs on nuclear data, nuclear metrology, nuclear reference materials and non-nuclear reference materials. Budget restrictions and personnel difficulties were encountered during 1987. Fission properties of 235U as a function of neutron energy and of the resonances can be successfully described on the basis of a three exit channel fission model. Double differential neutron emission cross-sections were accomplished on 7Li and were started for the tritium production cross-section of 9Be. Reference materials of uranium minerals and ores were prepared. Special nuclear targets were prepared. A batch of 250 g of Pu02 was characterized in view of certification as reference material for the elemental assay of plutonium

  2. Transuranium reference measurements and reference materials

    International Nuclear Information System (INIS)

    During the 30 years of its existence, the Central Bureau for Nuclear Measurements has been involved in numerous high-accuracy investigations of mainly nuclear properties of elements important for the nuclear fuel cycle and for application of relevant radionuclides. This paper reports that these studies were made possible by the availability of particle accelerators (150-MeV electron linear accelerator; 3.7- and 7-MV Van de Graaff accelerators) as neutron sources and the use of specialized laboratories for the preparation, characterization, and manipulation of radioactive samples. Examples of investigations with plutonium and neptunium are capture and fission cross sections of 239Pu at very low energies, spontaneous fission fragment mass and energy distributions of 242Pu at very low energies, spontaneous fission fragment mass and energy distributions of 242Pu, alpha-particle and gamma-ray spectra of 237Np, half-life of 241Pu, use of 237Np in reactor neutron dosimetry, preparation and characterization of plutonium oxide reference materials for nondestructive analysis, and demonstration of the potential of synthetic isotope mixtures for analytical control of the nuclear fuel cycle

  3. 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).

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

    International Nuclear Information System (INIS)

    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).

  5. AQCS intercomparison runs, reference materials 1991

    International Nuclear Information System (INIS)

    The purpose of the Analytical Quality Control Services programme provided by the IAEA is to assist laboratories engaged in the analysis of nuclear, environmental, biological, and materials of marine origin for radionuclide, major, minor and trace elements, as well as stable isotopes using atomic and nuclear analytical techniques, to check the quality of their work. The determination of accuracy requires special procedures such as analysis to be carried out by as many different and independent methods, analysts and techniques as possible, control analysis with reference materials and participation in interlaboratory comparison studies. This document gives details of the specimens and samples which the IAEA intends to distribute in 1991. Tabs

  6. 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.

  7. Neutron activation analysis of reference materials

    International Nuclear Information System (INIS)

    The importance is pointed out of neutron activation analysis in the preparation of reference materials, and studies are reported conducted recently by UJV. Instrumental neutron activation analysis has been used in testing homogeneity and in determining 28 elements in newly prepared reference standards of coal fly ash designated ENO, EOP and ECH. For accuracy testing, the same method was used in the analysis of NBS SRM-1633a Trace Elements in Coal Fly Ash and IAEA CRM Soil-5 and RM Soil-7. Radiochemical neutron activation analysis was used in determining Cd, Cu, Mn, Mo, and Zn in biological materials NBS SRM-1577 Bovine Liver, Bowen's Kale and in IAEA RM Milk Powder A-11 and Animal Muscle H-4. In all instances very good precision and accuracy of neutron activation analysis results were shown. (author)

  8. 40 CFR 1042.910 - Reference materials.

    Science.gov (United States)

    2010-07-01

    ... reference as prescribed in 5 U.S.C. 552(a) and 1 CFR part 51. Anyone may inspect copies at the U.S. EPA, Air... 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...

  9. Automated extraction of DNA from reference samples from various types of biological materials on the Qiagen BioRobot EZ1 Workstation

    DEFF Research Database (Denmark)

    Stangegaard, Michael; Jørgensen, Mads; Hansen, Anders Johannes;

    2009-01-01

    We have validated and implemented a protocol for DNA extraction from various types of biological materials using a Qiagen BioRobot EZ1 Workstation. The sample materials included whole blood, blood from deceased, buccal cells on Omni swabs and FTA Cards, blood on FTA Cards and cotton swabs......, and muscle biopsies. The DNA extraction was validated according to EN/ISO 17025 for the STR kits AmpFlSTR« Identifiler« and AmpFlSTR« Yfiler« (Applied Biosystems). Of 298 samples extracted, 11 (4%) did not yield acceptable results. In conclusion, we have demonstrated that extraction of DNA from various types...... of biological material can be performed quickly and without the use of hazardous chemicals, and that the DNA may be successfully STR typed according to the requirements of forensic genetic investigations accredited according to EN/ISO 17025...

  10. Bisphenol A polycarbonate as a reference material

    Science.gov (United States)

    Hilado, C. J.; Cumming, H. J.; Williams, J. B.

    1977-01-01

    Test methods require reference materials to standardize and maintain quality control. Various materials have been evaluated as possible reference materials, including a sample of bisphenol A polycarbonate without additives. Screening tests for relative toxicity under various experimental conditions were performed using male mice exposed to pyrolysis effluents over a 200-800 C temperature range. It was found that the bisphenol A polycarbonate served as a suitable reference material as it is available in large quantities, and does not significantly change with time.

  11. 40 CFR 1043.100 - Reference materials.

    Science.gov (United States)

    2010-07-01

    ... in 5 U.S.C. 552(a) and 1 CFR part 51. Anyone may inspect copies at the U.S. EPA, Air and Radiation... 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...

  12. Flotation of Biological Materials

    Directory of Open Access Journals (Sweden)

    George Z. Kyzas

    2014-03-01

    Full Text Available Flotation constitutes a gravity separation process, which originated from the minerals processing field. However, it has, nowadays, found several other applications, as for example in the wastewater treatment field. Concerning the necessary bubble generation method, typically dispersed-air or dissolved-air flotation was mainly used. Various types of biological materials were tested and floated efficiently, such as bacteria, fungi, yeasts, activated sludge, grape stalks, etc. Innovative processes have been studied in our Laboratory, particularly for metal ions removal, involving the initial abstraction of heavy metal ions onto a sorbent (including a biosorbent: in the first, the application of a flotation stage followed for the efficient downstream separation of metal-laden particles. The ability of microorganisms to remove metal ions from dilute aqueous solutions (as most wastewaters are is a well-known property. The second separation process, also applied effectively, was a new hybrid cell of microfiltration combined with flotation. Sustainability in this field and its significance for the chemical and process industry is commented.

  13. Environmental reference materials methods and case studies

    DEFF Research Database (Denmark)

    Schramm-Nielsen, Karina Edith

    1998-01-01

    evaluation of certification data. The plots illustrate consistency between replicate measurements on samples from a batch of reference material, carried out in a number of laboratories according to a staggered nested design. The development of a reference material is illustrated by a series of experiments......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...

  14. Making Biological Materials

    Institute of Scientific and Technical Information of China (English)

    Julian F.V.Vincent

    2005-01-01

    @@ 1 Chemistry and synthesis 1.1 Production and control of materials These days there can be few people who do not know that proteins are defined by DNA. DNA is made of two strands, each of which has along it, like a string of fairy lights, side branches that meet between the strands and hold them together.

  15. 49 CFR 171.7 - Reference material.

    Science.gov (United States)

    2010-10-01

    ... A and B), V, VIII (Division 1), and IX of 1998 Edition of American Society of Mechanical Engineers... sections in which the material is referenced. Source and name of material 49 CFR reference American... Infectious Agents, 1998 173.134 American Institute of Chemical Engineers (AIChE), 3 Park Avenue New York,...

  16. Artful interfaces within biological materials

    Directory of Open Access Journals (Sweden)

    John W.C. Dunlop

    2011-03-01

    Full Text Available Biological materials have a wide range of mechanical properties matching their biological function. This is achieved via complex structural hierarchies, spanning many length scales, arising from the assembly of different sized building blocks during growth. The interfaces between these building blocks can increase resistance to fracture, join materials of different character, make them deform more easily and provide motility. While they represent only a tiny fraction of the overall volume, interfaces are essential for the integrity and function of the overall tissue. Understanding their construction principles, often based on specialized molecular assemblies, may change our current thinking about composite materials.

  17. Development of solid radium-226 reference materials

    International Nuclear Information System (INIS)

    Radium-226 reference materials having a matrix similar to soil or tailings samples are not available in sufficient quantity for use by remedial-action contractors to calibrate their laboratory gamma-ray spectrometers. Such reference materials are needed to provide uniform standardization among measurements made by remedial-action contractors. A task, therefore, was undertaken to prepare about 200 pounds each of three different concentrations of radium-226 reference materials by diluting tailings with high-purity silica. Target values for radium-226 content were 50, 15, and 5 pCi/g. The radium-226 content of the reference materials was measured by C.W. Sill of EG and G Idaho, Inc., Idaho Falls, using a high- resolution alpha spectrometry technique standardized with National Bureau of Standards (NBS) standard 4961. A summary of this technique is provided in Appendix A of this report. An independent measurement of the radium-226 content was conducted by Bendix Field Engineering Corporation (Bendix), Grand Junction, Colorado, using a high-resolution Ge(Li) detector, which was calibrated using the New Brunswick Laboratory (NBL) 100-A Series standards. The Ge(Li) detector has also been used to determine the radium-226 content in the calibration models at the Grand Junction facility; these models are used by remedial-action contractors for calibration of borehole logging gamma-ray probes. 8 references, 12 tables

  18. Certified reference materials for organic analysis

    International Nuclear Information System (INIS)

    This presentation discusses the requirements for certified reference materials (CRMs) to be used in measurements of residues of pesticides in food and environmental samples. It deals with the types of CRMs, matrix selection, sample preparation and representativeness. It also discusses CRM validity period and gives some examples of CRM preparation

  19. [Possibilities of testing the biological acceptability of composite filling materials, with special reference to the microscopic test for pulp vitality. Review of the literature].

    Science.gov (United States)

    Nyárasdy, I

    1990-08-01

    The main problem of microscopically observing the living pulpa consists in that it lies embedded into hard tissue. The haemodynamics of the pulpa may be defined by studying the physical parameters by examining the characteristics of blood flow and by the factors determining them. By comparison with other tissues little work is dealing with regulating the blood flow. The vital microscopic model of the rat incisor pulpa was first employed by Gängler to testing dental filling materials. The results thereof well complete the findings of standardized tests. On basis of the foregoing the sublining in case of clinical employment of composite filling materials is unconditionally suggested. PMID:2401373

  20. Biological materials: a materials science approach.

    Science.gov (United States)

    Meyers, Marc A; Chen, Po-Yu; Lopez, Maria I; Seki, Yasuaki; Lin, Albert Y M

    2011-07-01

    The approach used by Materials Science and Engineering is revealing new aspects in the structure and properties of biological materials. The integration of advanced characterization, mechanical testing, and modeling methods can rationalize heretofore unexplained aspects of these structures. As an illustration of the power of this methodology, we apply it to biomineralized shells, avian beaks and feathers, and fish scales. We also present a few selected bioinspired applications: Velcro, an Al2O3-PMMA composite inspired by the abalone shell, and synthetic attachment devices inspired by gecko.

  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. Development and use of reference materials and quality control materials

    International Nuclear Information System (INIS)

    Current knowledge is summarized on correct use of commercially available certified reference materials (CRMs) and reference materials (RMs). Acknowledged are also the limitations and restrictions analysts have to face if they want to apply quality control. The concept of in-house RMs or quality control materials (QCMs) is advocated to supplement the use of CRMs for quality control purposes. On hand advice on how to select, prepare, characterize and use these QCMs is given from the experts' perspective. Several scenarios are described to make this concept widely applicable to: advanced laboratories with CRMs with validated analytical techniques available, laboratories with less experience and facilities, as well as cases were labile compounds and unstable matrices are involved. Each scenario considers different approaches to overcome the lack of appropriate CRMs and advise on the preparation of QCMs, which might fit the particular purpose

  4. 78 FR 16472 - Deposit of Biological Materials

    Science.gov (United States)

    2013-03-15

    ... United States Patent and Trademark Office Deposit of Biological Materials ACTION: Proposed collection....'' SUPPLEMENTARY INFORMATION: I. Abstract The deposit of biological materials as part of a patent application is... use the invention as specified by 35 U.S.C. 112. The term ``biological material'' is defined by 37...

  5. 75 FR 6348 - Deposit of Biological Materials

    Science.gov (United States)

    2010-02-09

    ... Patent and Trademark Office Deposit of Biological Materials ACTION: Proposed collection; comment request....Fawcett@uspto.gov . Include ``0651-0022 Deposit of Biological Materials comment'' in the subject line of....Hanlon@uspto.gov . SUPPLEMENTARY INFORMATION: I. Abstract The deposit of biological materials as part...

  6. An outline of reference materials for analysis techniques in China

    International Nuclear Information System (INIS)

    This paper provides background information on the development in the field of reference materials in China. The major considerations in development of reference materials include homogeneity, stability, handling procedures and certification. Further it discusses the plans for development in the near future specific natural-matrix reference materials containing low levels of trace elements and having high degree of homogeneity

  7. Certification of a nickel metal reference material for neutron dosimetry (EC Nuclear Reference Material 521)

    International Nuclear Information System (INIS)

    Nickel metal, of 99.99 % nominal purity and natural isotopic composition, in the form of 0.1 mm thick foil and 0.5 mm diameter wire has been certified for its cobalt mass fraction. The certified value of cobalt (<0.1μg.g-1) is based on 38 results obtained by neutron activation analysis, emission spectrometry with inductively coupled plasma excitation and atomic absorption spectrometry, whereas the isotopic composition of the nickel was verified by thermal ionization mass spectrometry. The material is intended to be used as a reference material in neutron metrology

  8. Certification of an iron metal reference material for neutron dosimetry (EC nuclear reference material 524)

    International Nuclear Information System (INIS)

    Iron metal, of > 99.996% nominal purity, in the form of 0.1 mm thick foil and of 0.5 mm diameter wire has been certified for its manganese and cobalt mass fractions. The certified value of the cobalt mass fraction (-1) is based on 39 accepted results from five laboratories using two different methods. The certified value of the manganese mass fraction (-1) is based on 41 accepted results from five laboratories using three different methods. The overall purity was also verified. The material is intended to be used as a reference material in neutron dosimetry. (authors). 8 refs., 9 tabs., 2 figs

  9. Análise epidemiológica dos acidentes com material biológico registrados no Centro de Referência em Saúde do Trabalhador - Londrina-PR Epidemiological analysis of accidents with biological material reported to the Worker's Health Reference Center in Londrina-PR

    OpenAIRE

    Regina Stella Spagnuolo; Renata Cristina Silva Baldo; Ivan Amaral Guerrini

    2008-01-01

    OBJETIVO: Analisar a distribuição dos acidentes de trabalho com exposição a material biológico das fichas de notificação registradas no Centro de Referência de Saúde do Trabalhador de Londrina, traçando um perfil dos profissionais acidentados. MÉTODOS: Trata-se de um estudo retrospectivo descritivo, com abordagem quantitativa, realizado através de um levantamento nas 253 fichas de notificação de acidentes com material biológico que foram encaminhadas das instituições de saúde da área de abran...

  10. 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.

  11. 40 CFR 90.7 - Reference materials.

    Science.gov (United States)

    2010-07-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be inspected at U.S. EPA Air and Radiation... 19103. Document number and name 40 CFR part 90 reference ASTM D86-93: Standard Test Method for...., Warrendale, PA 15096-0001. Document number and name 40 CFR part 90 reference SAE J1930 September...

  12. 40 CFR 1065.1010 - Reference materials.

    Science.gov (United States)

    2010-07-01

    ... Federal Register approved the incorporation by reference as prescribed in 5 U.S.C. 552(a) and 1 CFR part... of the International System of Units (SI), Barry N. Taylor, Physics Laboratory 1065.20,...

  13. 40 CFR 89.6 - Reference materials.

    Science.gov (United States)

    2010-07-01

    ... 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be inspected at US EPA, OAR, 1200 Pennsylvania Ave... 19428-2959. Document number and name 40 CFR part 89 reference ASTM D86-97: “Standard Test Method for... Commonwealth Dr., Warrendale, PA 15096-0001. Document number and name 40 CFR part 89 reference SAE J244 June...

  14. 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.

  15. 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.

  16. 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

    2015-12-01

    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. PMID:26703723

  17. Certification of a uranium-238 dioxide reference material for neutron dosimetry (EC nuclear reference material 501)

    International Nuclear Information System (INIS)

    Uranium-238 oxide of 99.999% isotopic and 99.98% chemical purity was transformed into dioxide spheres of nominal 0.5 and 1.0 mm diameter by gel precipitation and subsequent calcination under carbon dioxide and under argon containing 5% hydrogen at 1 125 K. The spheres were analysed by thermal ionization mass spectrometry, including isotope dilution, by gravimetry and by potentiometric titration. On the basis of these analyses, the uranium mass fraction was certified at 879.4 ± 2.8 g.kg-1, and the 235U/U - and 238U/U abundances at 10.4 ± 0.5 mg.kg-1 and 999.9896 ± 0.0005 g.kg-1, respectively. The material is intended to be used as a reference material in neutron metrology

  18. New reference materials improvement of methods of measurements

    International Nuclear Information System (INIS)

    The report summarizes the development of about 120 reference materials in a variety of fields (non ferrous metals, trace element analysis, food products, biomedical analysis, physical and technical properties of solid materials). The document also provides practical advice for trace element analyses, describes the principles followed for certifying reference materials and provides recommendations for their use

  19. 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)

  20. Determination of carbon-14 in environmental level, solid reference materials

    Energy Technology Data Exchange (ETDEWEB)

    Blowers, Paul, E-mail: paul.blowers@cefas.co.uk [Cefas Lowestoft Laboratory, Pakefield Road, Lowestoft, Suffolk, NR33 0HT (United Kingdom); Caborn, Jane, E-mail: jane.a.caborn@nnl.co.uk [NNL, Springfields, Salwick, Preston, Lancashire, PR4 0XJ (United Kingdom); Dell, Tony [Veterinary Laboratories Agency, New Haw, Addlestone, Surrey, KT15 3NB (United Kingdom); Gingell, Terry [DSTL, Radiation Protection Services, Crescent Road, Alverstoke, Gosport, Hants, PO12 2DL (United Kingdom); Harms, Arvic [National Physical Laboratory, Hampton Road, Teddington, Middlesex, TW11 0LW (United Kingdom); Long, Stephanie [Radiological Protection Institute of Ireland, 3 Clonskeagh Square, Clonskeagh Road, Dublin 14, Ireland (United Kingdom); Sleep, Darren [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, LA1 4AP (United Kingdom); Stewart, Charlie [UKAEA (Waste Management Group), Chemical Support Services, D1310/14, Dounreay, Thurso, Caithness, KW14 7TZ (United Kingdom); Walker, Jill [Radiocarbon Dating, The Old Stables, East Lockinge, Wantage, Oxon OX12 8QY (United Kingdom); Warwick, Phil E. [GAU-Radioanalytical, National Oceanography Centre Southampton, European Way, Southampton, SO14 3ZH (United Kingdom)

    2011-10-15

    An intercomparison exercise to determine the {sup 14}C activity concentrations in a range of solid, environmental level materials was conducted between laboratories in the UK. IAEA reference materials, C2, C6 and C7, and an in-house laboratory QA material were dispatched in 2006 to ten laboratories comprising of members of the Analyst Informal Working Group (AIWG) and one other invited party. The laboratories performed the determinations using a number of techniques, and using the results each one was evaluated in terms of levels of precision, sensitivity and limits of detection. The results of the study show that all techniques are capable of successfully analysing {sup 14}C in environmental level materials, however, a shortage of certified environmental reference materials exists. The suitability of the IAEA reference materials and other material for use as reference materials was also assessed.

  1. Determination of carbon-14 in environmental level, solid reference materials

    International Nuclear Information System (INIS)

    An intercomparison exercise to determine the 14C activity concentrations in a range of solid, environmental level materials was conducted between laboratories in the UK. IAEA reference materials, C2, C6 and C7, and an in-house laboratory QA material were dispatched in 2006 to ten laboratories comprising of members of the Analyst Informal Working Group (AIWG) and one other invited party. The laboratories performed the determinations using a number of techniques, and using the results each one was evaluated in terms of levels of precision, sensitivity and limits of detection. The results of the study show that all techniques are capable of successfully analysing 14C in environmental level materials, however, a shortage of certified environmental reference materials exists. The suitability of the IAEA reference materials and other material for use as reference materials was also assessed.

  2. 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.

  3. 40 CFR 86.1 - Reference materials.

    Science.gov (United States)

    2010-07-01

    ....C. 552(a) and 1 CFR part 51. To enforce any edition other than that specified in this section, a... Chromatography, 1994 SAE Handbook—SAE International Cooperative Engineering Program, Volume 1: Materials, Fuels....094-8, 86.096-8. (iii) SAE J1850, July 1995, Class B Data Communication Network Interface,...

  4. Preparation and certification of the human hair reference material

    International Nuclear Information System (INIS)

    The preparation of the human hair reference material and the steps taken to confirm its homogeneity and stability as well as its certification are described. Certified values for 17 elements, which are of importance for human health, and reference values for the other 13 elements are provided for this material. (author)

  5. Standard and reference materials for marine science, revised edition, 1993

    OpenAIRE

    IOC for UNESCO

    1993-01-01

    This is the third edition of the catalog of reference materials suited for use in marine science, originally compiled in 1986 for NOAA, IOC and UNEP. The catalog lists close to 2,000 reference materials from sixteen producers and contains information about their proper use, sources, availability, and analyte concentrations. Indices are included for elements, isotopes, and organic compounds, as are cross references to CAS registry numbers, alternate names, and chemical structures of selected o...

  6. [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.

  7. [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. PMID:23387148

  8. Flouescence reference materials used for optical and biophotonic applications

    Science.gov (United States)

    Engel, A.; Otterman, C.; Klahn, J.; Enseling, D.; Korb, T.; Resch-Genger, U.; Hoffmann, K.; Schweizer, S.; Selling, J.; Kynast, U.; Koberling, F.; Rupertus, V.

    2007-07-01

    Fluorescence techniques are known for their high sensitivity and are widely used as analytical tools and detection methods for product and process control, material sciences, environmental and bio-technical analysis, molecular genetics, cell biology, medical diagnostics, and drug screening. According to DIN/ISO 17025 certified standards are used for fluorescence diagnostics having the drawback of giving relative values for fluorescence intensities only. Therefore reference materials for a quantitative characterization have to be related directly to the materials under investigation. In order to evaluate these figures it is necessary to calculate absolute numbers like absorption/excitation cross sections and quantum yield. This can be done for different types of dopands in different materials like glass, glass ceramics, crystals or nano crystalline material embedded in polymer matrices. Based on the optical spectroscopy data we will discuss options for characteristic doped glasses and glass ceramics with respect to scattering and absorption regime. It has shown recently for YAG:Ce glass ceramics that for a proper determination of the quantum efficiency in these highly scattering media a reference material with similar scattering and fluorescent properties is required. This may be performed using the emission decay measurement diagnostics, where the decay time is below 100 ns. In this paper we present first results of these aspects using well performing LUMOGEN RED organic pigments for a comparison of mainly transparent glass with glass ceramics doped with various amounts of dopands e.g. ions of raw earth elements and transition metals. The LUMOGEN red is embedded in silica and polyurethane matrices. Characterisations on wavelength accuracy and lifetime for different environmental conditions (temperature, UV irradiation) have been performed. Moreover intensity patterns and results for homogeneity, isotropy, photo and thermal stability will be discussed. In a next

  9. Additive manufacturing of biologically-inspired materials.

    Science.gov (United States)

    Studart, André R

    2016-01-21

    Additive manufacturing (AM) technologies offer an attractive pathway towards the fabrication of functional materials featuring complex heterogeneous architectures inspired by biological systems. In this paper, recent research on the use of AM approaches to program the local chemical composition, structure and properties of biologically-inspired materials is reviewed. A variety of structural motifs found in biological composites have been successfully emulated in synthetic systems using inkjet-based, direct-writing, stereolithography and slip casting technologies. The replication in synthetic systems of design principles underlying such structural motifs has enabled the fabrication of lightweight cellular materials, strong and tough composites, soft robots and autonomously shaping structures with unprecedented properties and functionalities. Pushing the current limits of AM technologies in future research should bring us closer to the manufacturing capabilities of living organisms, opening the way for the digital fabrication of advanced materials with superior performance, lower environmental impact and new functionalities. PMID:26750617

  10. Biological and physical conditions of macroinvertebrates in reference lowland streams

    Science.gov (United States)

    de Brouwer, Jan; Eekhout, Joris; Verdonschot, Piet

    2016-04-01

    Channelisation measures taken halfway the 20th century have had destructive consequences for the diversity of the ecology in the majority of the lowland streams in countries such as the Netherlands. Currently, stream restoration measures are being implemented in these degraded lowland streams, where design principles are often based on outdated relationships between biological and physical conditions. Little is known about the reference conditions in these streams. Therefore, the aim of this research is to quantify the relationships between biological and physical conditions of macroinvertebrates in reference lowland streams. The research was conducted in four near-natural lowland streams in Central Poland. Field data were obtained during a field campaign in 2011. The following data were obtained in a 50-m reach in each of the four streams: macroinvertebrate sampling, spatial habitat patterns, bathymetry, and flow-velocity. Furthermore, water level, light sensitivity and temperature sensors were installed to obtain the temporal dynamic of these streams. Macroinvertebrates were sampled in 9 different habitat types, i.e. sand, gravel, fine organic matter, stones, branches, leaves, silt, vegetation, and wood. Macroinvertebrates were determined to the highest taxonomic level possible. Data from the bathymetrical surveys were interpolated on a grid and bathymetrical metrics were determined. Flow velocity measurements were related to habitats and flow velocity metrics were determined. Analysis of the data shows that flow conditions vary among the different habitat, with a gradient from hard substrates towards soft substrates. Furthermore, the data show that stream as a unit best explains species composition, but also specific habitat conditions, such as substrate type and flow velocity, correlate with species composition. More specific, the data shows a strong effect of wood on species composition. These findings may have implications for stream restoration design, which

  11. Determination of rare earth and uranium in reference biological materials certified by the method of neutron activation analysis; Determinacao de terras raras e de uranio em materiais biologicos de referencia certificados pelo metodo de analise por ativacao com neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Lais H.P.; Saiki, Mitiko, E-mail: laispaciulli@gmail.com, E-mail: mitiko@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The objective of this study was to evaluate the precision and accuracy of the determinations of Sc, La, Ce, Nd, Sm, Eu, Tb, Yb, Lu and U in certified reference materials (CRMs). To solve the problem of interference from fission products of U in the determination of lanthanides were obtained correction factors for this interference for {sup 140}La, {sup 141}Ce, {sup 143}Ce, {sup 153}Sm and {sup 147}Nd. The experimental procedure of Neutron Activation Analysis consisted of irradiating aliquots of each of the CRMs with synthetic standards of elements under thermal neutron flux of the IEA-R1 nuclear reactor, followed by gamma-ray spectrometry using a high-resolution hyperpurity GE detector. The analyzes of CRMs indicate good accuracy and precision of results, demonstrating the feasibility of applying of established procedure in NAA of elements studied in organic vegetable matrices.

  12. 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

  13. Accidents with biological material in workers

    OpenAIRE

    Cleonice Andréa Alves Cavalcante; Elisângela Franco de Oliveira Cavalcante; Maria Lúcia Azevedo Ferreira de Macêdo; Eliane Cavalcante dos Santos; Soraya Maria de Medeiros

    2013-01-01

    The objective was to describe the accidents with biological material occurred among workers of Rio Grande do Norte, Brazil, between 2007 and 2009. Secondary data were collected in the National Notifiable Diseases Surveillance System by exporting data to Excel using Tabwin. Among the types of occupational accidents reported in the state, the biological accidents (no. = 1,170) accounted for 58.3% with a predominance of cases among nurses (48.6%). The percutaneous exposure was the most frequent ...

  14. 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

  15. Preparation and characterization of the fish reference material

    International Nuclear Information System (INIS)

    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-1) and methylmercury (MeHg = 0.245 ± 0.038 mg g-1), and informational values of lead and arsenic. (author)

  16. Anorganic fluorescence reference materials for decay time of fluorescence emission

    Science.gov (United States)

    Engel, A.; Ottermann, C.; Klahn, J.; Korb, T.; Resch-Genger, U.; Hoffmann, K.; Kynast, U.; Rupertus, V.

    2008-02-01

    Fluorescence techniques are known for their high sensitivity and are widely used as analytical tools, detection methods and imaging applications for product and process control, material sciences, environmental and bio-technical analysis, molecular genetics, cell biology, medical diagnostics, and drug screening. According to DIN/ISO 17025 certified standards are used for steady state fluorescence diagnostics, a method having the drawback of giving relative values for fluorescence intensities only. Therefore reference materials for a quantitative characterization have to be related directly to the materials under investigation. In order to evaluate these figures it is necessary to calculate absolute numbers such as absorption/excitation cross sections and quantum yield. This has been done for different types of dopands in different materials such as glass, glass ceramics, crystals or nano crystalline material embedded in polymer matrices. Samples doped with several fluophores of different emission wavelengths and decay times are required for fluorescent multiplexing applications. Decay times shorter than 100 ns are of special interest. In addition, a proper knowledge is necessary of quantum efficiency in highly scattering media. Recently, quantum efficiency in YAG:Ce glass ceramics has been successfully investigated. Glass and glass ceramics doped with threefold charged rare earth elements are available. However, these samples have the disadvantage of emission decay times much longer than 1 microsecond, due to the excitation and emission of their optical forbidden electronic transitions. Therefore first attempts have been made to produce decay-time standards based on organic and inorganic fluophores. Stable LUMOGEN RED pigments and YAG:Ce phosphors are diluted simultaneously in silicone matrices using a wide range of concentrations between 0.0001 and 2 wt%. Organic LUMOGEN RED has decay times in the lower nanosecond range with a slight dependency on concentration

  17. 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

  18. The preparation and certification of ten uranium reference materials

    International Nuclear Information System (INIS)

    This report describes the procedures involved in the preparation, analysis and certification of ten 'UREM' uranium-bearing materials for use as international reference materials. Recommended values for total U3O8 are assigned to all of the ten materials. Twenty-two laboratories from seven countries contributed a total of approximately 300 analytical results for each material. The analytical methods used were X-ray-fluorescence spectrometry, colorimetry, fluorimetry, neutron-activation analysis, and emission spectroscopy using an inductively coupled plasma source. Approximately 300 kg of each reference material was prepared, primarily for use by the South African uranium industry. However, a limited amount of each material is available for overseas laboratories

  19. 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

  20. Reference materials--a main element in a coherent reference measurement system.

    Science.gov (United States)

    Dybkaer, R

    1991-04-01

    The analytical reliability of any measurement procedure requires a specifically designed, coherent reference measurement system, including interrelated measurement procedures and measurement standards such as reference materials. The latter may be characterized by three sets of characteristics. The general characteristics comprise origin, mode of production, physical state and phase, homogeneity, physical form, container, additives, storage conditions, stability, and dangerous properties. The specific characteristics describe molecular composition, analyte, purity, matrix, quantity of interest (including scale), assigned value, and uncertainty of measurement. The additional characteristics concern the way in which values for other characteristics were obtained, the hierarchical position of the material, certificate, instructions for use, and intended function. The problem areas of reference materials comprise definition of the appropriate analyte, purification, matrix, assignment of values, and nomenclature. The present ambiguous terminology is presented and a systematic structure of descriptive names is proposed (tab. 1). PMID:1868129

  1. Using Raman spectroscopy to characterize biological materials.

    Science.gov (United States)

    Butler, Holly J; Ashton, Lorna; Bird, Benjamin; Cinque, Gianfelice; Curtis, Kelly; Dorney, Jennifer; Esmonde-White, Karen; Fullwood, Nigel J; Gardner, Benjamin; Martin-Hirsch, Pierre L; Walsh, Michael J; McAinsh, Martin R; Stone, Nicholas; Martin, Francis L

    2016-04-01

    Raman spectroscopy can be used to measure the chemical composition of a sample, which can in turn be used to extract biological information. Many materials have characteristic Raman spectra, which means that Raman spectroscopy has proven to be an effective analytical approach in geology, semiconductor, materials and polymer science fields. The application of Raman spectroscopy and microscopy within biology is rapidly increasing because it can provide chemical and compositional information, but it does not typically suffer from interference from water molecules. Analysis does not conventionally require extensive sample preparation; biochemical and structural information can usually be obtained without labeling. In this protocol, we aim to standardize and bring together multiple experimental approaches from key leaders in the field for obtaining Raman spectra using a microspectrometer. As examples of the range of biological samples that can be analyzed, we provide instructions for acquiring Raman spectra, maps and images for fresh plant tissue, formalin-fixed and fresh frozen mammalian tissue, fixed cells and biofluids. We explore a robust approach for sample preparation, instrumentation, acquisition parameters and data processing. By using this approach, we expect that a typical Raman experiment can be performed by a nonspecialist user to generate high-quality data for biological materials analysis. PMID:26963630

  2. SPOTS project and development of a standard and reference material

    Science.gov (United States)

    Burguete, R.; Patterson, E.

    2010-06-01

    The ‘Standardization Project for Optical Techniques of Strain measurement’ (SPOTS) was focused on the development of reference materials for calibrating optical systems for static strain measurement and standardized tests for evaluating the capabilities of such systems. The reference material consists of a beam in four-point bending within a monolithic frame that ensures reproducibility of the boundary and loading conditions. A procedure for the use of the reference material has been developed and leads to the evaluation of measurement uncertainties that allow the construction of confidence limits for the data obtained with the calibrated optical system. The design and methodology have been developed into a proposed draft standard which is being endorsed by VAMAS (Versailles Agreement on Materials And Standards) for review by ISO (International Standards Organisation). An overview of philosophy underpinning the proposed draft standard is presented and serves as an introduction to the reference material and standardized test and their use in providing higher confidence in optical measurements of strain.

  3. 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.

  4. 235Uranium isotope abundance certified reference material for gamma spectrometry EC nuclear reference material 171 certification report

    International Nuclear Information System (INIS)

    This certification report contains the information necessary for the final certification of EC nuclear reference material 171. It is also intended to inform the user of the reference material concerned on technical/scientific details which are not given in the certificate. The report describes the reference material which consists of sets of U3O8 samples with five different 235U/U abundances, filled in cylindrical aluminium cans. The can bottom serves as window for emitted gamma radiation. The report describes how the 235U/U abundances were characterized, how the other properties relevant for gamma measurements were determined and gives all connected results as well as those from the verification measurements. Appendix A represents the draft certificate. 32 refs

  5. 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.

  6. 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. PMID:26462921

  7. 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

  8. Element content and particle size characterization of a mussel candidate reference material

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Edson G.; Vasconcellos, Marina B.A., E-mail: emoreira@ipen.b, E-mail: mbvascon@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro do Reator de Pesquisas; Santos, Rafaela G. dos; Martinelli, Jose R., E-mail: jroberto@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencias e Tecnologia de Materiais

    2011-07-01

    The use of certified reference materials is an important tool in the quality assurance of analytical measurements. To assure reliability on recently prepared powder reference materials, not only the characterization of the property values of interest and their corresponding uncertainties, but also physical properties such as the particle size distribution must be well evaluated. Narrow particle size distributions are preferable than larger ones; as different size particles may have different analyte content. Due to this fact, the segregation of the coarse and the fine particles in a bottle may lead to inhomogeneity of the reference material, which should be avoided. In this study the element content as well as the particle size distribution of a mussel candidate reference material produced at IPEN-CNEN/SP was investigated. Instrumental Neutron Activation Analysis was applied to the determination of 15 elements in seven fractions of the material with different particle size distributions. Subsamples of the materials were irradiated simultaneously with elemental standards at the IEA-R1 research nuclear reactor and the induced gamma ray energies were measured in a hyperpure germanium detector. Three vials of the candidate reference material and three coarser fractions, collected during the preparation, were analyzed by Laser Diffraction Particle Analysis to determine the particle size distribution. Differences on element content were detected for fractions with different particle size distribution, indicating the importance of particle size control for biological reference materials. From the particle size analysis, Gaussian particle size distribution was observed for the candidate reference material with mean particle size {mu} = 94.6 {+-} 0.8 {mu}m. (author)

  9. 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.

  10. Blood plasma reference material: a global resource for proteomic research.

    Science.gov (United States)

    Malm, Johan; Danmyr, Pia; Nilsson, Rolf; Appelqvist, Roger; Végvári, Akos; Marko-Varga, György

    2013-07-01

    There is an ever-increasing awareness and interest within the clinical research field, creating a large demand for blood fraction samples as well as other clinical samples. The translational research area is another field that is demanding for blood samples, used widely in proteomics, genomics, as well as metabolomics. Blood samples are globally the most common biological samples that are used in a broad variety of applications in life science. We hereby introduce a new reference blood plasma standard (heparin) that is aimed as a global resource for the proteomics community. We have developed these reference plasma standards by defining the Control group as those with C-reactive protein levels 30 mg/L. In these references we have used both newborn children 1-2 weeks, as well as youngsters 15-30 years, and middle aged 30-50 years, and elderly patients at the ages of 65+. In total, there were 80 patients in each group in the reference plasma pools. We provide data on the developments and characteristics of the reference blood plasma standards, as well as what is used by the team members at the respective laboratories. The standards have been evaluated by pilot sample processing in biobanking operations and are currently a resource that allows the Proteomic society to perform quantitative proteomic studies. By the use of high quality reference plasma samples, global initiatives, such as the Chromosome Human Proteome Project (C-HPP), will benefit as one scientific program when the entire human proteome is mapped and linked to human diseases. The plasma reference standards are a global resource and can be accessed upon request. PMID:23701512

  11. Nanobiotechnology: synthetic biology meets materials science.

    Science.gov (United States)

    Jewett, Michael C; Patolsky, Fernando

    2013-08-01

    Nanotechnology, the area of science focused on the control of matter in the nanometer scale, allows ground-breaking changes of the fundamental properties of matter that are often radically different compared to those exhibited by the bulk counterparts. In view of the fact that dimensionality plays a key role in determining the qualities of matter, the realization of the great potential of nanotechnology has opened the door to other disciplines such as life sciences and medicine, where the merging between them offers exciting new applications, along with basic science research. The application of nanotechnology in life sciences, nanobiotechnology, is now having a profound impact on biological circuit design, bioproduction systems, synthetic biology, medical diagnostics, disease therapy and drug delivery. This special issue is dedicated to the overview of how we are learning to control biopolymers and biological machines at the molecular- and nanoscale. In addition, it covers far-reaching progress in the design and synthesis of nanoscale materials, thus enabling the construction of integrated systems in which the component blocks are comparable in size to the chemical and biological entities under investigation.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. Certification of a uranium dioxide reference material for chemical analyses

    International Nuclear Information System (INIS)

    This report, issued by the Central Bureau for Nuclear Measurements (CBNM), describes the characterization of a uranium dioxide reference material with accurately determined uranium mass fraction for chemical analyses. The preparation, conditioning, homogeneity tests and the analyses performed on this material are described in Annex 1. The evaluation of the individual impurity results, total of impurities and uranium mass fraction are given in Annex 2. Information on a direct determination of uranium by titration is given in Annex 3. The uranium mass fraction (881.34+-0.13) g.kg-1 calculated in Annex 2 is given on the certificate

  20. Development of a Thin Film Magnetic Moment Reference Material.

    Science.gov (United States)

    Pappas, D P; Halloran, S T; Owings, R R; da Silva, F C S

    2008-01-01

    In this paper we present the development of a magnetic moment reference material for low moment magnetic samples. We first conducted an inter-laboratory comparison to determine the most useful sample dimensions and magnetic properties for common instruments such as vibrating sample magnetometers (VSM), SQUIDs, and alternating gradient field magnetometers. The samples were fabricated and then measured using a vibrating sample magnetometer. Their magnetic moments were calibrated by tracing back to the NIST YIG sphere, SRM 2853. PMID:27096108

  1. Biological reference points for fish stocks in a multispecies context

    DEFF Research Database (Denmark)

    Collie, J.S.; Gislason, Henrik

    2001-01-01

    variation. For a prey species like sprat, fishing mortality reference levels should be conditioned on the level of predation mortality. For a predator species, a conservative level of fishing mortality can be identified that will prevent growth overfishing and ensure stock replacement. These first- order...

  2. 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.

  3. Solid freeform fabrication of biological materials

    Science.gov (United States)

    Wang, Jiwen

    This thesis investigates solid freeform fabrication of biological materials for dental restoration and orthopedic implant applications. The basic approach in this study for solid freeform fabrication of biological materials is micro-extrusion of single or multiple slurries for 3D components and inkjet color printing of multiple suspensions for functionally graded materials (FGMs). Common issues associated with micro-extrusion and inkjet color printing are investigated. These common issues include (i) formulation of stable slurries with a pseudoplastic property, (ii) cross-sectional geometry of the extrudate as a function of the extrusion parameters, (iii) fabrication path optimization for extrusion process, (iv) extrusion optimization for multi-layer components, (v) composition control in functionally graded materials, and (vi) sintering optimization to convert the freeform fabricated powder compact to a dense body for biological applications. The present study clearly shows that the rheological and extrusion behavior of dental porcelain slurries depend strongly on the pH value of the slurry and extrusion conditions. A slurry with pseudoplastic properties is a basic requirement for obtaining extruded lines with rectangular cross-sections. The cross-sectional geometry of the extrudate is also strongly affected by extrusion parameters including the extrusion nozzle height, nozzle moving speed, extrusion rate, and critical nozzle height. Proper combinations of these extrusion parameters are necessary in order to obtain single line extrudates with near rectangular cross-sections and 3D objects with dimensional accuracy, uniform wall thickness, good wall uprightness, and no wall slumping. Based on these understandings, single-wall, multi-wall, and solid teeth have been fabricated via micro-extrusion of the dental slurry directly from a CAD digital model in 30 min. Inkjet color printing using stable Al2O3 and ZrO 2 aqueous suspensions has been developed to fabricate

  4. Preparation and quality control of materials used in the reference buffer material

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, D.A.; Hnatiw, D.S.J.; Kohle, C.L.

    1992-09-15

    This document summarizes the methodologies developed for preparing the reference buffer material (RBM) for use in laboratory-scale and field-scale experiments. Two commercially available concrete mixers have been successfully used to repeatedly produce homogeneous bulk buffer and backfill materials. The components, blending procedures, quality control sampling requirements, and mixing checklists used in the production of the reference buffer material are presented. Use of these directions will ensure that consistent batching of sealing materials is achieved and operator-induced variability is minimized.

  5. Preparation and characterization of a Perna perna (Linnaeus, 1758) mussel reference material

    International Nuclear Information System (INIS)

    The use of certified reference materials in chemical analysis is an important requirement in quality assurance systems, as it allows the validation of analytical methods and the realization of the metrological traceability of results. Then, it is possible to obtain valid and comparable results not only in space, but also in time. In this study, all the steps for the preparation of a national mussel reference material were attained, from the collection of the bulk material to processing steps such as freeze-drying, grinding, bottling and sterilization. Internationally accepted principles were applied for the homogeneity and stability assessment of the material, using instrumental neutron activation analysis and atomic absorption spectrometry as analytical techniques. By means of a collaborative program with participation of Brazilian and foreign laboratories, the chemical characterization of the material was performed. Element content in the mass percentage to mg kg-1 range was determined for 47 elements and some radionuclides, naturally present in the material. With the application of suitable statistical treatment to the data, it was considered that the content of 11 of those elements may be certified: As, Ca, Cl, Co, K, Mg, Mn, Na, Se, Th and Zn. This study may be considered an important step in the national metrological development, as it shows that the production and characterization of biological reference materials, mussel in particular, is feasible in Brazil, as a tool for quality assurance of environmental and nutritional studies performed in the country. (author)

  6. Reference materials for nondestructive assay of special nuclear material. Volume 1. Uranium oxide plus graphite powder

    International Nuclear Information System (INIS)

    This manual describes the fabrication of reference materials for use in gamma-ray-based nondestructive assay of low-density uranium-bearing samples. The sample containers are 2-l bottles. The reference materials consist of small amounts of UO2 spread throughout a graphite matrix. The 235U content ranges from 0 to 100 g. The manual also describes the far-field assay procedure used with low-resolution detectors

  7. Self-Reference, Biologic and the Structure of Reproduction

    CERN Document Server

    Kauffman, Louis H

    2015-01-01

    This paper concentrates on relationships of formal systems with biology. The paper is based on previous papers by the author. We have freely used texts of those papers where the formulations are of use, and we have extended the concepts and discussions herein considerably beyond the earlier work. We concentrate on formal systems not only for the sake of showing how there is a fundamental mathematical structure to biology, but also to consider and reconsider philosophical and phenomenological points of view in relation to natural science and mathematics. The relationship with phenomenology comes about in the questions that arise about the nature of the observer in relation to the observed that arise in philosophy, but also in science in the very act of determining the context and models upon which it shall be based.We examine the schema behind the reproduction of DNA. The DNA molecule consists of two interwound strands, the Watson Strand (W) and the Crick Strand (C). The two strands are bonded to each other vi...

  8. Reference Material IAEA 434: Naturally Occurring Radionuclides in Phosphogypsum

    International Nuclear Information System (INIS)

    Phosphogypsum is generated as a by-product of the phosphoric acid based fertilizer industry. The discharge of phosphogypsum on earth surface deposits is a potential source of enhanced natural radiation and heavy metals, and the resulting environmental impact should be considered carefully to ensure safety and compliance with environmental regulations. In addition, phosphogypsum can be used to make several building materials and it is used in agriculture as a conditioner to maintain soil productivity in areas where soils are poor and erode easily. A reliable determination of naturally occurring radionuclides in phosphogypsum is necessary to comply with the radiation protection and environmental regulations. The IAEA-434 will assist laboratories in the IAEA Member States in validating their analytical methods for the determination of naturally occurring radionuclides in phosphogypsum and to control the quality of the produced analytical results. Reference values for the massic activities and associated standard uncertainties were established for: Pb-210, Ra-226, Th-230, U-234 and U-238. During sample production and certification, the requirements for reference material production and certification as stated in ISO guides 34 and 35 were taken into account. This report summarizes the preparation and certification process

  9. Preparation, characterization and certification of uranium isotope reference materials

    International Nuclear Information System (INIS)

    This work describes the preparation, characterization and certification of a set of uranium isotope reference materials ranging from 0.5 to 20.0 % of 235U 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(235U)/n(238U) was certified in the materials produced to expanded uncertainties ranging from 0.02 to 0.10 % and the ratios n(234U)/n(238U) and n(236U)/n(238U), 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)

  10. Electrodynamics in Arbitrary Reference Frames and in Arbitrary Material Media

    International Nuclear Information System (INIS)

    Full text: The investigation of electromagnetic phenomena in material media still belongs to the most difficult tasks of electrodynamics. Complexity and variability of material media practically exclude effective applications of methods and computational techniques elaborated in the framework of standard microscopic electrodynamics with classical vacuum as a ground state. In order to obtain satisfactorily exact descriptions of electromagnetic properties of complex material media one is enforced to use methods and approximations which are difficult to control. Moreover, they usually break covariance properties and the results obtained are valid in one reference frame which choice remains subjective and model dependent. Some time ago we have proposed a reformulation of Maxwell electrodynamics which opens new ways in study of electromagnetic processes in material media. The formalism gets rid of assumptions characteristic for vacuum electrodynamics only and it avoids the usage of constitutive relations as primary relations put on quantities needed for a complete description of an electromagnetic system. Fundamental properties of all electromagnetic quantities are their uniquely defined transformation rules and their analysis allows to determine the possible relations between them. Within such a scheme it is possible to introduce constitutive relations which do not have analogies in macroscopic classical electrodynamics. They may be used in description of microscopic electromagnetic processes in a different way than it is done in the framework of quantum electrodynamics. (author)

  11. 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.

  12. 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.

  13. Novel application of high pressure processing for the production of shellfish toxin matrix reference materials.

    Science.gov (United States)

    Turner, Andrew D; Powell, Andy L; Burrell, Stephen

    2014-11-01

    The production of homogeneous and stable matrix reference materials for marine biotoxins is important for the validation and implementation of instrumental methods of analysis. High pressure processing was investigated to ascertain potential advantages this technique may have in stabilising paralytic shellfish poisoning toxins in shellfish tissues compared to untreated materials. Oyster tissues were subjected to a range of different temperatures and pressures, with results showing a significant reduction in biological activity in comparison to control samples, without significantly altering toxin profiles. Tissue subjected to pressures >600 MPa at 50 °C was assessed for homogeneity and stability. The sample homogeneity was determined using a pre-column oxidation LC-FLD method and shown to be within accepted levels of within batch repeatability. Short and long-term stability studies were conducted over a range of temperatures, with analysis by pre and post column oxidation LC-FLD demonstrating improved stability of toxins compared to the untreated materials and with epimerisation of toxins also notably reduced in treated materials. This study confirmed the technique of high pressure processing to improve the stability of PSP toxins compared to untreated wet tissues and highlighted its applicability in reference material preparation where removal of biological activity is of importance.

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

    International Nuclear Information System (INIS)

    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  <7 nm, vertical sidewall (slope mostly within 90°  ±  0.5°) and very small line width variation (LWR down to 0.36 nm). The application of the developed sample for calibrating the scaling factor and effective tip geometry of the CD-AFM are demonstrated. The scaling factor of the CD-AFM is calibrated to be 0.9988, coinciding well with the theoretical value 1 as the tool was calibrated to a traceable metrological atomic force microscope. The effective width of a CDR120-EBD tip is calibrated as 128.32 nm. Finally, a strategy for the non-destructive calibration of the developed sample is introduced, which enables the application of the reference material in practice. (paper)

  15. 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.

  16. Scalar material reference systems and loop quantum gravity

    Science.gov (United States)

    Giesel, K.; Thiemann, T.

    2015-07-01

    In the past, the possibility to employ (scalar) material reference systems in order to describe classical and quantum gravity directly in terms of gauge invariant (Dirac) observables has been emphasized frequently. This idea has been picked up more recently in loop quantum gravity with the aim to perform a reduced phase space quantization of the theory, thus possibly avoiding problems with the (Dirac) operator constraint quantization method for a constrained system. In this work, we review the models that have been studied on the classical and/or the quantum level and parametrize the space of theories considered so far. We then describe the quantum theory of a model that, to the best of our knowledge, has only been considered classically so far. This model could arguably be called the optimal one in this class of models considered as it displays the simplest possible true Hamiltonian, while at the same time reducing all constraints of general relativity.

  17. 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.

  18. Ultrafast spectroscopy in biological and organic materials

    Science.gov (United States)

    Bai, Guang

    This thesis consists of an experimental investigation of the dynamics of the biological material, visual pigment rhodopsin, and the persistent hole burning material, octaethylpophine-doped polystyrene (OEP/PS), utilizing femtosecond laser spectroscopy. The cis-trans isomerization of the retinal chromophore in rhodopsin at ambient temperature has been studied by employing a novel three beam femtosecond transient absorption method, and a new model is proposed. Two- thirds of the excited rhodopsin molecules isomerize promptly via curve-crossing to form bathorhodopsin in ~200 femtoseconds. The remaining third will miss curve-crossing and stay in the excited state, which never isomerizes and decays to the ground state rhodopsin in ~3 picoseconds. These results are consistent with recent two-beam femtosecond transient experiments[1-6] and agree well with molecular dynamics calculations[7-8]. The three-beam pump-probe measurement is an important technical advance in the characterization of transient species in the initial step of vision, which directly measures the formation dynamics of the ground state species. Using this technique, we could drive the bathorhodopsin back into rhodopsin. This is the first experimental evidence of trans to cis formation of rhodopsin at ambient temperature. The characteristic parameters and phototransformation pathway of OEP/PS have been studied for optical storage applications. Femtosecond accumulated photon echo and time-resolved absorption spectroscopy were used. The optical dephasing time T2 for a laser bandwidth covering the whole inhomogeneous zero-phonon absorption band is 200 ± 50 ps at 1.4 K. T2 reduces significantly to 100 ps when the temperature increases to 4.2 K. This temperature dependence indicates that OEP/PS must operate at very low temperatures. The saturation dose is 6 J/cm2. The maximum number of readings is equivalent to the same amount of energy of writing. 150 fs single-shot detection of a 4-bit packet stored in an

  19. Reference values and action levels of biological monitoring in occupational exposure.

    Science.gov (United States)

    Ong, C N

    1999-09-01

    The primary objectives of biological monitoring are (1) to prevent health impairment, (2) to assist in the assessment of risk, and (3) to evaluate the effectiveness of environmental controls. An efficient way to achieve these objectives would be to enforce the compliance of biological exposure standards at the workplace. However, biological monitoring should be viewed in the total context of control and prevention of work-related diseases, and not merely to comply with permissible standards. Biological monitoring depends very much on the conditions that the chemical is absorbed and how it is metabolised. Genetic diversity could therefore contribute to significant differences in this aspect. Furthermore, many of the reference values established have so far not been fully validated and therefore their usefulness is rather limited. This paper reviews and illustrates using some recent findings to show that biological reference values are influenced not just by the above mentioned issues, but also factors such as (1) health and nutritional status of the exposed population, (2) social and cultural factors, and (3) climatic conditions. Caution has to be taken when considering having an action level for some of the biological reference value. Biological reference values set without considering people, technology, and working conditions would be fraught with difficulties in implementation. PMID:10511254

  20. Laser interaction with biological material mathematical modeling

    CERN Document Server

    Kulikov, Kirill

    2014-01-01

    This book covers the principles of laser interaction with biological cells and tissues of varying degrees of organization. The problems of biomedical diagnostics are considered. Scattering of laser irradiation of blood cells is modeled for biological structures (dermis, epidermis, vascular plexus). An analytic theory is provided which is based on solving the wave equation for the electromagnetic field. It allows the accurate analysis of interference effects arising from the partial superposition of scattered waves. Treated topics of mathematical modeling are: optical characterization of biological tissue with large-scale and small-scale inhomogeneities in the layers, heating blood vessel under laser irradiation incident on the outer surface of the skin and thermo-chemical denaturation of biological structures at the example of human skin.

  1. Reference material manufacture and certification for the AVNG

    Energy Technology Data Exchange (ETDEWEB)

    Hauck, Danielle K [Los Alamos National Laboratory; Thron, Jonathan [Los Alamos National Laboratory; MacArthur, Duncan W. [Los Alamos National Laboratory; Livke, Alexander [RFNC - VNIIEF; Bulatov, M [RFNC-VNIIEF; Kondratov, Sergey [RFNC-VNIIEF; Leplyavkina, M [RFNC-VNIIEF; Razinkov, Sergey [RFNC-VNIIEF; Sivachev, D [RFNC-VNIIEF; Tsybryaev, S [RFNC-VNIIEF; V' yushin, A [RFNC-VNIIEF

    2010-07-09

    Testing and demonstration of any radiation measurement system requires the use of appropriate radioactive sources. An attribute measurement system (A VNG) was developed and fabricated at the Russian Federal Nuclear Center, VNIIEF, Russia, under contract with LANL, USA. The A VNG detects neutron and gamma radiation signatures and compares the data analysis results with the specified threshold values for three unclassified attributes; plutonium is present or absent, plutonium mass is greater than or less than the specified threshold value and plutonium isotopic ratio 240Pu to 239Pu) is greater than or less then the threshold value. A set of reference materials (RMs) was specially manufactured for the A VNG with masses and isotopic ratios above and below the selected thresholds. The set of RMs was certified in compliance with the Russian metrological requirements. The RMs were used to debug and test the A VNG and to demonstrate the A VNG operation to an American delegation in June 2009. In this presentation, we will describe the various steps in the manufacture and certification of these RM sources.

  2. 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.

  3. Reference material manufacture and certification for the AVNG

    International Nuclear Information System (INIS)

    Testing and demonstration of any radiation measurement system requires the use of appropriate radioactive sources. An attribute measurement system (A VNG) was developed and fabricated at the Russian Federal Nuclear Center, VNIIEF, Russia, under contract with LANL, USA. The A VNG detects neutron and gamma radiation signatures and compares the data analysis results with the specified threshold values for three unclassified attributes; plutonium is present or absent, plutonium mass is greater than or less than the specified threshold value and plutonium isotopic ratio 240Pu to 239Pu) is greater than or less then the threshold value. A set of reference materials (RMs) was specially manufactured for the A VNG with masses and isotopic ratios above and below the selected thresholds. The set of RMs was certified in compliance with the Russian metrological requirements. The RMs were used to debug and test the A VNG and to demonstrate the A VNG operation to an American delegation in June 2009. In this presentation, we will describe the various steps in the manufacture and certification of these RM sources.

  4. 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.

  5. The acquisition of dangerous biological materials :

    Energy Technology Data Exchange (ETDEWEB)

    Aceto, Donato Gonzalo; Astuto-Gribble, Lisa M.; Gaudioso, Jennifer M.

    2007-11-01

    Numerous terrorist organizations have openly expressed interest in producing and deploying biological weapons. However, a limiting factor for many terrorists has been the acquisition of dangerous biological agents, as evidenced by the very few successful instances of biological weapons use compared to the number of documented hoaxes. Biological agents vary greatly in their ability to cause loss of life and economic damage. Some agents, if released properly, can kill many people and cause an extensive number of secondary infections; other agents will sicken only a small number of people for a short period of time. Consequently, several biological agents can potentially be used to perpetrate a bioterrorism attack but few are likely capable of causing a high consequence event. It is crucial, from a US national security perspective, to more deeply understand the likelihood that terrorist organizations can acquire the range of these agents. Few studies have attempted to comprehensively compile the technical information directly relevant to the acquisition of dangerous bacteria, viruses and toxins. In this report, technical fact sheets were assembled for 46 potentially dangerous biological agents. Much of the information was taken from various research sources which could ultimately and significantly expedite and improve bioterrorism threat assessments. By systematically examining a number of specific agent characteristics included in these fact sheets, it may be possible to detect, target, and implement measures to thwart future terrorist acquisition attempts. In addition, the information in these fact sheets may be used as a tool to help laboratories gain a rudimentary understanding of how attractive a method laboratory theft is relative to other potential acquisition modes.

  6. 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…

  7. 40 CFR 600.011-93 - Reference materials.

    Science.gov (United States)

    2010-07-01

    ... 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be inspected at the U.S. Environmental Protection.... Document number and name 40 CFR part 600 reference ASTM E 29-67 (Reapproved 1973) Standard Recommended... the U.S. and Canada), or at http://www.sae.org. Document No. and name 40 CFR part 600 reference...

  8. 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.

  9. Biological issues in materials science and engineering: Interdisciplinarity and the bio-materials paradigm

    Science.gov (United States)

    Murr, L. E.

    2006-07-01

    Biological systems and processes have had, and continue to have, important implications and applications in materials extraction, processing, and performance. This paper illustrates some interdisciplinary, biological issues in materials science and engineering. These include metal extraction involving bacterial catalysis, galvanic couples, bacterial-assisted corrosion and degradation of materials, biosorption and bioremediation of toxic and other heavy metals, metal and material implants and prostheses and related dental and medical biomaterials developments and applications, nanomaterials health benefits and toxicity issue, and biomimetics and biologically inspired materials developments. These and other examples provide compelling evidence and arguments for emphasizing biological sicences in materials science and engineering curricula and the implementation of a bio-materials paradigm to facilitate the emergence of innovative interdisciplinarity involving the biological sciences and materials sciences and engineering.

  10. 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.

  11. Material science lesson from the biological photosystem

    Science.gov (United States)

    Kim, Younghye; Lee, Jun Ho; Ha, Heonjin; Im, Sang Won; Nam, Ki Tae

    2016-08-01

    Inspired by photosynthesis, artificial systems for a sustainable energy supply are being designed. Each sequential energy conversion process from light to biomass in natural photosynthesis is a valuable model for an energy collection, transport and conversion system. Notwithstanding the numerous lessons of nature that provide inspiration for new developments, the features of natural photosynthesis need to be reengineered to meet man's demands. This review describes recent strategies toward adapting key lessons from natural photosynthesis to artificial systems. We focus on the underlying material science in photosynthesis that combines photosystems as pivotal functional materials and a range of materials into an integrated system. Finally, a perspective on the future development of photosynthesis mimetic energy systems is proposed.

  12. Sustainable production of biological materials for food and agricultural applications

    OpenAIRE

    Angün, Pınar

    2013-01-01

    Ankara : Materials Science and Nanotechnology Program of Graduate School of Engineering and Science of Bilkent University, 2013. Thesis (Master's) -- Bilkent University, 2013. Includes bibliographical references leaves 94-110. Angün, Pınar Master's

  13. Novel biological materials for food and environmental applications

    OpenAIRE

    Umu, Özgün Candan Onarman

    2012-01-01

    Ankara : The Materials Science and Nanotechnology Program of the Graduate School of Engineering and Science of Bilkent University, 2012. Thesis (Master's) -- Bilkent University, 2012. Includes bibliographical references leaves 71-86. Umu, Özgün Candan Onarman Master's

  14. Cost-effective production of biological materials for food applications

    OpenAIRE

    Han, Diren

    2012-01-01

    Ankara : The Materials Science and Nanotechnology Program of the Graduate School of Engineering and Science of Bilkent University, 2012. Thesis (Master's) -- Bilkent University, 2012. Includes bibliographical references leaves 67-74. Han, Diren Master's

  15. Development of Certified Reference Materials for Diarrhetic Shellfish Poisoning Toxins, Part 2: Shellfish Matrix Materials.

    Science.gov (United States)

    McCarron, Pearse; Reeves, Kelley L; Giddings, Sabrina D; Beach, Daniel G; Quilliam, Michael A

    2016-09-01

    Okadaic acid (OA) and its analogs, dinophysistoxins-1 (DTX1) and -2 (DTX2) are lipophilic biotoxins produced by marine algae that can accumulate in shellfish and cause the human illness known as diarrhetic shellfish poisoning (DSP). Regulatory testing of shellfish is required to protect consumers and the seafood industry. Certified reference materials (CRMs) are essential for the development, validation, and quality control of analytical methods, and thus play an important role in toxin monitoring. This paper summarizes work on research and development of shellfish tissue reference materials for OA and DTXs. Preliminary work established the appropriate conditions for production of shellfish tissue CRMs for OA and DTXs. Source materials, including naturally incurred shellfish tissue and cultured algae, were screened for their DSP toxins. This preliminary work informed planning and production of a wet mussel (Mytilus edulis) tissue homogenate matrix CRM. The homogeneity and stability of the CRM were evaluated and found to be fit-for-purpose. Extraction and LC-tandem MS methods were developed to accurately certify the concentrations of OA, DTX1, and DTX2 using a combination of standard addition and matrix-matched calibration to compensate for matrix effects in electrospray ionization. The concentration of domoic acid was also certified. Uncertainties were assigned following standards and guidelines from the International Organization for Standardization. The presence of other toxins in the CRM was also assessed and information values are reported for OA and DTX acyl esters.

  16. Acquisition of improved reference values for cesium, iodine, strontium, thorium, and uranium in selected NIST reference materials.

    Science.gov (United States)

    Parr, R M; Kawamura, H; Iyengar, G V

    1999-01-01

    As part of a study on the ingestion and organ content of some trace elements of importance in radiological protection, additional work has been undertaken to acquire improved reference values for cesium, iodine, strontium, thorium, and uranium in four selected reference materials provided by the US National Institute of Standards and Technology. The materials are SRM-1548 Total Diet, SRM-1548a Typical Diet, SRM-1486 Bone Meal, and RM-8414 Bovine Muscle. A coordinated study was undertaken with the help of seven selected laboratories in five countries. Instrumental and radiochemical neutron activation analysis and inductively coupled plasma-mass spectrometry were the analytical main techniques used. PMID:10676473

  17. 10 CFR 431.443 - Materials incorporated by reference.

    Science.gov (United States)

    2010-01-01

    ... this section for incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Any... 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)...

  18. 9 CFR 77.1 - Material incorporated by reference.

    Science.gov (United States)

    2010-01-01

    ... been approved for incorporation by reference into the Code of Federal Regulations by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. (a) The procedures... 1141, USDA South Building, 14th Street and Independence Avenue, SW., Washington, DC; or (3) May...

  19. Editorial:Mechanics of biological and bio-inspired materials%Editorial: Mechanics of biological and bio-inspired materials

    Institute of Scientific and Technical Information of China (English)

    Baohua Jia

    2012-01-01

    The field of mechanics of biological and bio-inspired materials underwent an exciting development over the past several years,which made it stand at the cutting edge of both engineering mechanics and biomechanics.As an intriguing interdisciplinary research field,it aims at elucidating the fundamental principles in nature's design of strong,multi-functional and smart Materials by focusing on the assembly,deformation,stability and failure of the materials.These principles should have wide applications in not only material sciences and mechanical engineering but also biomedical engineering.For instance,the knowledge in Mechanical principles of biological materials is very helpful for addressing some major challenges in material sciences and engineering.They also have the potential to provide quantitative understanding about how forces and deformation affect human being's health,diseases and treatment at tissue,cellular and molecular levels.This special subject on "mechanics of biological and bio-inspired materials" collects a few studies on recent development by leading scientists in this field.The biological materials or systems in these studies include cell,cytoskeleton (e.g.,microtubulus,intermediate filaments),lipid molecules and composite system of lipid and nanoparticle,tissue,and biological attachment systems,etc.

  20. Certification of the uranium hexafluoride reference materials for isotopic composition

    OpenAIRE

    MIALLE SÉBASTIEN; Richter, Stephan; HENNESSY Carmel; TRUYENS Jan; Jakobsson, Ulf; Aregbe, Yetunde

    2014-01-01

    The IRMM-019 to IRMM-029 series of uranium hexafluoride materials is certified for the isotopic composition. After conversion into uranyl nitrate solution, certification and homogeneity measurements were performed by Thermal Ionization Mass Spectrometry. Analyses were performed by Modified Total Evaporation and for some materials the major isotope amount ratio n(235U)/n(238U) was measured using a n(233U)/n(236U) double spike. Measurements were confirmed by UF6 Gas Source Mass Spectrometry. Ma...

  1. Materiomics: biological protein materials, from nano to macro

    Directory of Open Access Journals (Sweden)

    Steven Cranford

    2010-11-01

    Full Text Available Steven Cranford, Markus J BuehlerCenter for Materials Science and Engineering, Laboratory for Atomistic and Molecular Mechanics, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USAAbstract: Materiomics is an emerging field of science that provides a basis for multiscale material system characterization, inspired in part by natural, for example, protein-based materials. Here we outline the scope and explain the motivation of the field of materiomics, as well as demonstrate the benefits of a materiomic approach in the understanding of biological and natural materials as well as in the design of de novo materials. We discuss recent studies that exemplify the impact of materiomics – discovering Nature’s complexity through a materials science approach that merges concepts of material and structure throughout all scales and incorporates feedback loops that facilitate sensing and resulting structural changes at multiple scales. The development and application of materiomics is illustrated for the specific case of protein-based materials, which constitute the building blocks of a variety of biological systems such as tendon, bone, skin, spider silk, cells, and tissue, as well as natural composite material systems (a combination of protein-based and inorganic constituents such as nacre and mollusk shells, and other natural multiscale systems such as cellulose-based plant and wood materials. An important trait of these materials is that they display distinctive hierarchical structures across multiple scales, where molecular details are exhibited in macroscale mechanical responses. Protein materials are intriguing examples of materials that balance multiple tasks, representing some of the most sustainable material solutions that integrate structure and function despite severe limitations in the quality and quantity of material building blocks. However, up until now, our attempts to analyze and

  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. Analysis and Design of Biological Materials and Structures

    CERN Document Server

    Öchsner, Andreas; Altenbach, Holm

    2012-01-01

    This collection provides researchers and scientists with advanced analyses and materials design techniques in Biomaterials and presents mechanical studies of biological structures. In 16 contributions well known experts present their research on Stress and Strain Analysis, Material Properties, Fluid and Gas mechanics and they show related problems.

  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. Hearing Tests on Mobile Devices: Evaluation of the Reference Sound Level by Means of Biological Calibration

    Science.gov (United States)

    Kipiński, Lech; Grysiński, Tomasz; Kręcicki, Tomasz

    2016-01-01

    Background Hearing tests carried out in home setting by means of mobile devices require previous calibration of the reference sound level. Mobile devices with bundled headphones create a possibility of applying the predefined level for a particular model as an alternative to calibrating each device separately. Objective The objective of this study was to determine the reference sound level for sets composed of a mobile device and bundled headphones. Methods Reference sound levels for Android-based mobile devices were determined using an open access mobile phone app by means of biological calibration, that is, in relation to the normal-hearing threshold. The examinations were conducted in 2 groups: an uncontrolled and a controlled one. In the uncontrolled group, the fully automated self-measurements were carried out in home conditions by 18- to 35-year-old subjects, without prior hearing problems, recruited online. Calibration was conducted as a preliminary step in preparation for further examination. In the controlled group, audiologist-assisted examinations were performed in a sound booth, on normal-hearing subjects verified through pure-tone audiometry, recruited offline from among the workers and patients of the clinic. In both the groups, the reference sound levels were determined on a subject’s mobile device using the Bekesy audiometry. The reference sound levels were compared between the groups. Intramodel and intermodel analyses were carried out as well. Results In the uncontrolled group, 8988 calibrations were conducted on 8620 different devices representing 2040 models. In the controlled group, 158 calibrations (test and retest) were conducted on 79 devices representing 50 models. Result analysis was performed for 10 most frequently used models in both the groups. The difference in reference sound levels between uncontrolled and controlled groups was 1.50 dB (SD 4.42). The mean SD of the reference sound level determined for devices within the same model

  6. 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.

  7. Household Hazardous Materials and Their Labels: A Reference for Teachers.

    Science.gov (United States)

    Dean, Lillian F.

    Household hazardous materials are products or wastes which are toxic, corrosive, reactive, and/or ignitable. Although common products such as pesticides, oils, gasoline, solvents, cleaners, and polishes are hazardous, students and adults are not always aware of potential dangers. This sourcebook contains definitions and examples of household…

  8. 10 CFR 431.95 - Materials incorporated by reference.

    Science.gov (United States)

    2010-01-01

    ... INDUSTRIAL EQUIPMENT Commercial Air Conditioners and Heat Pumps Test Procedures § 431.95 Materials... published in 1998, “Water-source heat pumps—Testing and rating for performance—Part 1: Water-to-air and...) published in 2004, “Standard for Packaged Terminal Air-Conditioners and Heat Pumps,” IBR approved for §...

  9. 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.

  10. 16O thin film reference materials for nuclear reaction analysis

    International Nuclear Information System (INIS)

    Full text: Thin film Ta2O5 samples were distributed to CRP participants for use in the round-robin exercise. This appendix describes how these samples were prepared and characterized. Preparation was made using anodic oxidation of tantalum using an electrolyte solution of 4% ammonium citrate prepared with water of natural 16O isotopic composition. A constant anodising current of 4 mA/cm2 was maintained until the desired electrolysis v voltage was reached, then stopped immediately. The areal density of 16O in these thin Ta2O5 films was determined by NRA using the method described elsewhere and comparing the data with that from a primary anodic Ta2O5 standard kindly made available to us by Dr C. Ortega of GPS, Paris. The 16O(d,p1)14N reaction at 850 keV was used with the protons detected with a 300 mm2 silicon detector located at an angle of 150 deg. A 12 μm MylarTM foil covered the detector. Detector count rates were kept sufficiently low so that deadtime corrections are negligible. There are various sources of uncertainty which when compounded, produce the final uncertainty in the 16O areal density of the thin film samples. The major sources of uncertainty are: 1. The primary reference standard is estimated to have an absolute value that is within ± 3% of the true value. 2. There is a small low energy tail on the p1 peak in the NRA spectrum, most likely due to oxygen dissolved in the bulk tantalum. The counts in this tailing are less than 2% of the gross counts recorded in the spectrum peak, and similar in magnitude from sample to sample. We assign a systematic error of 0.5% to the background correction for all samples. There is negligible change in the total sample uncertainty when this systematic error is added in quadrature to the uncertainty of the primary reference standard. 3. The reproducibility of peak areas from several measurements was better than 1%. This indicates that sample homogeneity and current integration were both sufficiently good that their

  11. The host response to allogeneic and xenogeneic biological scaffold materials.

    Science.gov (United States)

    Keane, Timothy J; Badylak, Stephen F

    2015-05-01

    The clinical use of biological scaffold materials has become commonplace. Such scaffolds are composed of extracellular matrix (ECM), or components of ECM, derived from allogeneic or xenogeneic tissues. Such scaffold materials vary widely in their source tissue, processing methods and sterilization methods. The success or failure of an ECM scaffold for a given application is dependent on the host response following implantation; a response that is largely mediated by the innate immune system and which is influenced by a numerous factors, including the processing methods used in the preparation of biological scaffolds. The present paper reviews various aspects of the host response to biological scaffolds and factors that affect this response. In addition, some of the logistical, regulatory and reconstructive implications associated with the use of biological scaffolds are discussed. PMID:24668694

  12. Certification of uranium hexafluoride reference materials for isotopic composition

    International Nuclear Information System (INIS)

    The IRMM-019 to IRMM-029 series of uranium hexafluoride materials is certified for the isotopic composition. After conversion into uranyl nitrate solution, certification and homogeneity measurements were performed by thermal ionization mass spectrometry. Analyses were performed by Modified Total Evaporation and for some materials the major isotope amount ratio n(235U)/n(238U) was measured using a n(233U)/n(236U) double spike. Measurements were confirmed by UF6 gas source mass spectrometry. Major isotope amount ratios were certified with relative expanded uncertainties (k = 2) of 0.015-0.030 % and the minor isotope amount ratios n(234U)/n(238U) and n(236U)/n(238U) were certified with relative expanded uncertainties of 0.02-3 %. (author)

  13. Alpha damage in non-reference waste form matrix materials

    International Nuclear Information System (INIS)

    Although bitumen is the matrix material currently used for European α-bearing intermediate level waste streams, polymer and polymer-modified cement matrices could have advantages over bitumen for such wastes. Two organic matrix systems have been studied - an epoxide resin, and an epoxide modified cement. Alpha irradiations were carried out by incorporating 241Am at approx. 0.9 Ci/l. Comparisons have been made with unirradiated material and with materials which had been γ-irradiated to the same dose as the α-irradiated samples. Measurements were made of dimensional changes, mechanical properties and the leaching behaviour of 241Am and 137Cs. A limited amount of swelling (< 3%) was observed in α-irradiated epoxide resin; none was observed in the epoxide modified cement. Gamma irradiation to 300 kGy has no significant effect on the mechanical properties of either system. However, alpha irradiation to the same dose produced significant changes in flexural strength, an increase for the polymer and a decrease for the polymer-cement. Leaching in these systems was found to be a diffusion-controlled process; alpha irradiation to approx. 250 kGy has little effect on the leaching behaviour of either system. (author)

  14. Standard reference materials: srm 768: temperature reference standard for use below 0. 5 k

    Energy Technology Data Exchange (ETDEWEB)

    Stolen, R.J. Jr; Dove, R.B.

    1979-04-01

    Cryogenic temperature scales are now available (viz., the newly created EPT-76) which are quite accurate and which extend deep into the cryogenic region (as low as 0.5 K). It is the region below 0.5 K where no formal scale exists which is of concern here. By developing a compact device which provides five reference temperatures from 0.015 K to 0.21 K, the authors hope to provide a lingua franca by which experimental results of different laboratories involving the parameter temperature may be meaningfully compared. Such a device, designated SRM 768, is now available and consists of a self-contained assembly of coils and five samples which can be used to provide in situ temperature calibration. Simple room temperature electronics readily permit the observation of the five narrow and highly reproducible superconducting phase transitions. These phase transitions have been assigned temperature values by means of fundamental thermometers used at the National Bureau of Standards. Provided that care is exercised in reducing the magnetic field acting upon the device, the user can confidently expect to achieve a temperature reproducibility and traceability to the NBS temperature scale of plus or minus 0.3 mK.

  15. Flexible Organic Electronics in Biology: Materials and Devices.

    Science.gov (United States)

    Liao, Caizhi; Zhang, Meng; Yao, Mei Yu; Hua, Tao; Li, Li; Yan, Feng

    2015-12-01

    At the convergence of organic electronics and biology, organic bioelectronics attracts great scientific interest. The potential applications of organic semiconductors to reversibly transmit biological signals or stimulate biological tissues inspires many research groups to explore the use of organic electronics in biological systems. Considering the surfaces of movable living tissues being arbitrarily curved at physiological environments, the flexibility of organic bioelectronic devices is of paramount importance in enabling stable and reliable performances by improving the contact and interaction of the devices with biological systems. Significant advances in flexible organic bio-electronics have been achieved in the areas of flexible organic thin film transistors (OTFTs), polymer electrodes, smart textiles, organic electrochemical ion pumps (OEIPs), ion bipolar junction transistors (IBJTs) and chemiresistors. This review will firstly discuss the materials used in flexible organic bioelectronics, which is followed by an overview on various types of flexible organic bioelectronic devices. The versatility of flexible organic bioelectronics promises a bright future for this emerging area. PMID:25393596

  16. Flexible Organic Electronics in Biology: Materials and Devices.

    Science.gov (United States)

    Liao, Caizhi; Zhang, Meng; Yao, Mei Yu; Hua, Tao; Li, Li; Yan, Feng

    2015-12-01

    At the convergence of organic electronics and biology, organic bioelectronics attracts great scientific interest. The potential applications of organic semiconductors to reversibly transmit biological signals or stimulate biological tissues inspires many research groups to explore the use of organic electronics in biological systems. Considering the surfaces of movable living tissues being arbitrarily curved at physiological environments, the flexibility of organic bioelectronic devices is of paramount importance in enabling stable and reliable performances by improving the contact and interaction of the devices with biological systems. Significant advances in flexible organic bio-electronics have been achieved in the areas of flexible organic thin film transistors (OTFTs), polymer electrodes, smart textiles, organic electrochemical ion pumps (OEIPs), ion bipolar junction transistors (IBJTs) and chemiresistors. This review will firstly discuss the materials used in flexible organic bioelectronics, which is followed by an overview on various types of flexible organic bioelectronic devices. The versatility of flexible organic bioelectronics promises a bright future for this emerging area.

  17. Materials Manufactured from 3D Printed Synthetic Biology Arrays

    Science.gov (United States)

    Gentry, Diana; Micks, Ashley

    2013-01-01

    Many complex, biologically-derived materials have extremely useful properties (think wood or silk), but are unsuitable for space-related applications due to production, manufacturing, or processing limitations. Large-scale ecosystem-based production, such as raising and harvesting trees for wood, is impractical in a self-contained habitat such as a space station or potential Mars colony. Manufacturing requirements, such as the specialized equipment needed to harvest and process cotton, add too much upmass for current launch technology. Cells in nature are already highly specialized for making complex biological materials on a micro scale. We envision combining these strengths with the recently emergent technologies of synthetic biology and 3D printing to create 3D-structured arrays of cells that are bioengineered to secrete different materials in a specified three-dimensional pattern.

  18. Chemical analysis and biological testing of materials from the EDS coal liquefaction process: a status report

    Energy Technology Data Exchange (ETDEWEB)

    Later, D.W.; Pelroy, R.A.; Wilson, B.W.

    1984-05-01

    Representative process materials were obtained from the EDS pilot plant for chemical and biological analyses. These materials were characterized for biological activity and chemical composition using a microbial mutagenicity assay and chromatographic and mass spectrometric analytical techniques. The two highest boiling distillation cuts, as well as process solvent (PS) obtained from the bottoms recycle mode operation, were tested for initiation of mouse skin tumorigenicity. All three materials were active; the crude 800/sup 0 +/F cut was substantially more potent than the crude bottoms recycle PS or 750 to 800/sup 0/F distillate cut. Results from chemical analyses showed the EDS materials, in general, to be more highly alkylated and have higher hydroaromatic content than analogous SRC II process materials (no in-line process hydrogenation) used for comparison. In the microbial mutagenicity assays the N-PAC fractions showed greater activity than did the aliphatic hydrocarbon, hydroxy-PAH, or PAH fractions, although mutagenicity was detected in certain PAH fractions by a modified version of the standard microbial mutagenicity assay. Mutagenic activities for the EDS materials were lower, overall, than those for the corresponding materials from the SRC II process. The EDS materials produced under different operational modes had distinguishable differences in both their chemical constituency and biological activity. The primary differences between the EDS materials studied here and their SRC II counterparts used for comparison are most likely attributable to the incorporation of catalytic hydrogenation in the EDS process. 27 references, 28 figures, 27 tables.

  19. Instrumental neutron activation analysis of marine sediment in-house reference material

    International Nuclear Information System (INIS)

    Reference materials play an important role in demonstrating the quality and reliability of analytical data. The advantage of using in-house reference materials is that they provide a relatively cheap option as compared to using commercially available certified reference material (CRM) and can closely resemble the laboratory routine test sample. A marine sediment sample was designed as an in-house reference material, in the framework of quality assurance and control (QA/QC) program of the Neutron Activation Analysis (NAA) Laboratory at Nuclear Malaysia. The NAA technique was solely used for the homogeneity test of the marine sediment sample. The CRM of IAEA- Soil 7 and IAEA- SL1 (Lake Sediment) were applied in the analysis as compatible matrix based reference materials for QA purposes. (Author)

  20. [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.

  1. Development of reference materials for SNF NDA systems

    Energy Technology Data Exchange (ETDEWEB)

    Klann, R. T.

    2000-02-29

    The Department of Energy has over 200 different fuel types which will be placed in a geologic repository for ultimate disposal. At the present time, DOE EM is responsible for assuring safe existing conditions, achieving interim storage, and preparing for final disposition. Each task is governed by regulations which dictate a certain degree of knowledge regarding the contents and condition of the fuel. This knowledge and other associated characteristics are referred to as data needs. It is the stance of DOE EM, that personnel and economic resources are not available to obtain the necessary data to characterize such individual fuel type for final disposal documentation purposes. In addition, it is beyond the need of DOE to do so. This report describes the effort to classify the 200+ fuel types into a subset of fuel types for the purpose of non-destructive analysis (NDA) measurement system development and demonstration testing in support of the DOE National Spent Nuclear Fuel (NSNFP) Program. The fuel types have been grouped into 37 groups based on fuel composition, fuel form, assembly size, enrichment, and other characteristics which affect NDA measurements (e.g., neutron poisons).

  2. 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.

  3. Near-Infrared Fluorescent Materials for Sensing of Biological Targets

    Directory of Open Access Journals (Sweden)

    Julia Xiaojun Zhao

    2008-05-01

    Full Text Available Near-infrared fluorescent (NIRF materials are promising labeling reagents for sensitive determination and imaging of biological targets. In the near-infrared region biological samples have low background fluorescence signals, providing high signal to noise ratio. Meanwhile, near-infrared radiation can penetrate into sample matrices deeply due to low light scattering. Thus, in vivo and in vitro imaging of biological samples can be achieved by employing the NIRF probes. To take full advantage of NIRF materials in the biological and biomedical field, one of the key issues is to develop intense and biocompatible NIRF probes. In this review, a number of NIRF materials are discussed including traditional NIRF dye molecules, newly developed NIRF quantum dots and single-walled carbon nanotubes, as well as rare earth metal compounds. The use of some NIRF materials in various nanostructures is illustrated. The enhancement of NIRF using metal nanostructures is covered as well. The fluorescence mechanism and bioapplications of each type of the NIRF materials are discussed in details.

  4. 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.

  5. Electron Microscopy of Biological Materials at the Nanometer Scale

    Science.gov (United States)

    Kourkoutis, Lena Fitting; Plitzko, Jürgen M.; Baumeister, Wolfgang

    2012-08-01

    Electron microscopy of biological matter uses three different imaging modalities: (a) electron crystallography, (b) single-particle analysis, and (c) electron tomography. Ideally, these imaging modalities are applied to frozen-hydrated samples to ensure an optimal preservation of the structures under scrutiny. Cryo-electron microscopy of biological matter has made important advances in the past decades. It has become a research tool that further expands the scope of structural research into unique areas of cell and molecular biology, and it could augment the materials research portfolio in the study of soft and hybrid materials. This review addresses how researchers using transmission electron microscopy can derive structural information at high spatial resolution from fully hydrated specimens, despite their sensitivity to ionizing radiation, despite the adverse conditions of high vacuum for samples that have to be kept in aqueous environments, and despite their low contrast resulting from weakly scattering building blocks.

  6. Biological evaluation of dental materials, in vitro and in vivo

    International Nuclear Information System (INIS)

    In this paper, the correlation between the user of tissue culture for in vitro tests and the tissue irritability and pupal response observed in in vitro tests, will be discussed. It would produce confusion if dental materials were standardised with the unreliable parameter of the living system in dynamic balance. Biological tests, both in vitro and in vivo, should be used for pre-standards testing, without any political control to establish physicochemical standards. As a first step, corrosion tests and the dissolution dosje of toxic components from the material in the tissue culture medium and/or artificial salvia should be standardised under conditions simulating the oral environment. The CNC method and photo-pattern analysis are used for the interpretation of cytotoxicity. The need for biological testing, both in vitro and in vivo, definitely exists in order to obtain physicochemical standards, with a biological simulation depending upon the feedback obtained from the results of in vitro and in vivo tests

  7. Twenty five years of reference material activity at Agriculture and Agri-Food Canada.

    Science.gov (United States)

    Ihnat, M

    2001-06-01

    In the mid 1970s, the available RMs, notably Bowen's Kale and Orchard Leaves and Bovine liver from National Bureau of Standards (NBS), although of great benefit, were overwhelmingly insufficiently representative, in respect of matrix and elemental composition, of the wide range of natural products submitted for analysis and in worldwide commerce. To provide additional coverage, an RM development project was initiated with input from cooperating analysts leading to an Agriculture and Agri-Food Canada/National Institute of Standards and Technology (NIST) cooperative venture and development of a total of 12 different agricultural/food RMs. With a total of 303 concentration values for 34 elements and a wide range of matrix components such as ash, silica, protein, fat, carbohydrate and fiber, these RMs significantly augment the world repertoire of biological control materials. A final material under consideration is a highly reliable, discrete, synthetic RM for quality control and calibration. This paper summarizes the research and developmental activities undertaken during the past quarter of a century related to RM development at Agriculture and Agri-Food Canada and includes a short historical background, conceptual considerations, preparation, physical characterization, homogeneity estimation, chemical characterization, calculation of recommended reference values and associated uncertainties, methodology development and application, and performance of inorganic analytical methods in a multielement, multilaboratory, collaborative characterization campaign. PMID:11451252

  8. Estimation of the minimum uncertainty of DNA concentration in a genetically modified maize sample candidate certified reference material.

    Science.gov (United States)

    Prokisch, J; Zeleny, R; Trapmann, S; Le Guern, L; Schimmel, H; Kramer, G N; Pauwels, J

    2001-08-01

    Homogeneity testing and the determination of minimum sample mass are an important part of the certification of reference materials. The smallest theoretically achievable uncertainty of certified concentration values is limited by the concentration distribution of analyte in the different particle size fractions of powdered biological samples. This might be of special importance if the reference material is prepared by dry mixing, a dilution technique which is used for the production of the new and third generation of genetically modified (GMO) plant certified reference materials. For the production of dry mixed PMON 810 maize reference material a computer program was developed to calculate the theoretically smallest uncertainty for a selected sample intake. This model was used to compare three differently milled maize samples, and the effect of dilution on the uncertainty of the DNA content of GMO maize was estimated as well. In the case of a 50-mg sample mass the lowest achievable standard deviation was 2% for the sample containing 0.1% GMO and the minimum deviation was less than 0.5% for the sample containing 5% GMO. PMID:11569879

  9. Reference material IAEA 413: Major, minor and trace elements in algae

    International Nuclear Information System (INIS)

    Reference materials are a basic requirement for any sort of quantitative chemical and radiochemical analysis. Laboratories need them for calibration and quality control throughout their analytical work. The IAEA started to produce reference materials in the early 1960s to meet the needs of the analytical laboratories in its Member States that required reference materials for quality control of their measurements. The initial efforts were focused on the preparation of environmental reference materials containing anthropogenic radionuclides for use by those laboratories employing nuclear analytical techniques. These reference materials were characterized for their radionuclide content through interlaboratory comparison involving a core group of some 10 to 20 specialist laboratories. The success of these early exercises led the IAEA to extend its activities to encompass both terrestrial and marine reference materials containing primordial radionuclides and trace elements. Today, the IAEA has more than 90 reference materials and maintains a customer base of about 5000 members from more than 85 Member States. Within the frame of IAEA activities in production and certification of RM, this report describes the certification of the IAEA 413: Major, minor and trace elements in algae. Details are given on methodologies and data evaluation

  10. Remediation of anionic surfactants and ammonium by biological materials

    OpenAIRE

    Sarıoğlu, Ömer Faruk

    2012-01-01

    Ankara : The Materials Science and Nanotechnology Program of the Graduate School of Engineering and Science of Bilkent University, 2012. Thesis (Master's) -- Bilkent University, 2012. Includes bibliographical references leaves 83-97. Sarıoğlu, Ömer Faruk Master's

  11. Nanostructured materials for biological imaging and chemical sensing

    OpenAIRE

    Yıldırım, Adem

    2014-01-01

    Ankara : Materials Science and Nanotechnology Program of the Graduate School of Engineering and Science of Bilkent University, 2014. Thesis (Ph.D.) -- Bilkent University, 2014. Includes bibliographical references leaves 116-139. Yıldırım, Adem Ph. D.

  12. The Role of Reference Condition in Biological Assessment and Criteria: An EPA Guidance Document

    Science.gov (United States)

    Southerland, M. T.; Larsen, D. P.; Davis, W. S.

    2005-05-01

    The U.S. Environmental Protection Agency is preparing a document to provide States, Tribes, and other practitioners with guidelines on the reference condition concept and how to apply it in their water management programs, particularly for assessing the condition of aquatic resources. These guidelines are intended to broaden the implementation of biological monitoring and assessment, to increase the consistency among States and Tribes, and to improve the success of individual programs. Establishing and using the reference condition concept appropriately is critical to implementing biocriteria and tiered aquatic life uses to protect and restore water resource quality. This document will cover the following topics: a description of the concept of reference condition and related concepts (including minimally disturbed, least disturbed, and attainable conditions); methods for characterizing reference and related conditions; the role of water body classification to partition natural variability; setting thresholds to determine achievement of a target condition; and application of the concept in heavily modified regions (e.g., urban landscapes; agricultural regions) and waterbodies (reservoirs, regulated rivers). A section on frequently asked questions and answers is included. Throughout the document, examples are drawn from existing State and Tribal programs to illustrate specific applications that are consistent with the guidelines.

  13. Reference materials for nondestructive assay of special nuclear material. Volume 2. Thin metal foils of highly enriched uranium

    International Nuclear Information System (INIS)

    This report describes the fabrication of reference materials for use in gamma-ray-based nondestructive assay of small high-density uranium samples. The sample containers are small Petri dishes. The reference materials consist of thin circular discs of highly enriched uranium metal foil. The 235U content ranges from 0.2 to 10 g. The report also describes the assay procedure used with low-resolution detectors

  14. 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.

  15. Structure and mechanics of interfaces in biological materials

    Science.gov (United States)

    Barthelat, Francois; Yin, Zhen; Buehler, Markus J.

    2016-04-01

    Hard biological materials — for example, seashells, bone or wood — fulfil critical structural functions and display unique and attractive combinations of stiffness, strength and toughness, owing to their intricate architectures, which are organized over several length scales. The size, shape and arrangement of the ‘building blocks’ of which these materials are made are essential for defining their properties and their exceptional performance, but there is growing evidence that their deformation and toughness are also largely governed by the interfaces that join these building blocks. These interfaces channel nonlinear deformations and deflect cracks into configurations in which propagation is more difficult. In this Review, we discuss comparatively the composition, structure and mechanics of a set of representative biological interfaces in nacre, bone and wood, and show that these interfaces possess unusual mechanical characteristics, which can encourage the development of advanced bioinspired composites. Finally, we highlight recent examples of synthetic materials inspired from the mechanics and architecture of natural interfaces.

  16. Synthetic Self-Assembled Materials in Biological Environments.

    Science.gov (United States)

    Versluis, Frank; van Esch, Jan H; Eelkema, Rienk

    2016-06-01

    Synthetic self-assembly has long been recognized as an excellent approach for the formation of ordered structures on the nanoscale. Although the development of synthetic self-assembling materials has often been inspired by principles observed in nature (e.g., the assembly of lipids, DNA, proteins), until recently the self-assembly of synthetic molecules has mainly been investigated ex vivo. The past few years however, have witnessed the emergence of a research field in which synthetic, self-assembling systems are used that are capable of operating as bioactive materials in biological environments. Here, this up-and-coming field, which has the potential of becoming a key area in chemical biology and medicine, is reviewed. Two main categories of applications of self-assembly in biological environments are identified and discussed, namely therapeutic and imaging agents. Within these categories key concepts, such as triggers and molecular constraints for in vitro/in vivo self-assembly and the mode of interaction between the assemblies and the biological materials will be discussed. PMID:27042774

  17. 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)

  18. Traceability and quality requirements for reference materials. The context for trace element speciation

    International Nuclear Information System (INIS)

    For over forty years the International Atomic Energy Agency (IAEA), through its Analytical Quality Control Services (AQCS), has prepared and distributed reference materials (RMs) to the analytical laboratories in its Member States to assist them in maintaining/improving the quality of their analytical measurements and to help them achieve internationally acceptable levels of quality assurance. With each new material, AQCS especially attempts to address the needs in developing Member States since these may be outside the regular programme of the national and regional commercial RMs suppliers. The AQCS programme responds to the recommendations of consultants' and working groups convened by the Agency's Director General and closely co-operates with technical assistance and co-ordinated research programmes that involve analytical measurements. The IAEA RMs include matrices of environmental and biological origin, characterised for primordial and anthropogenic radionuclides, stable isotopes, organic contaminants and inorganic elements. Preparation, characterisation and distribution of IAEA RMs is carried out by different Sections and Units of the IAEA Laboratories located in Austria and Monaco. RMs of terrestrial origin, characterised for inorganic elements and radionuclides, are mainly prepared by the Chemistry Unit (CU) located in Seibersdorf, Austria. RMs characterised for stable isotopes, H-3 and C-14 are prepared by the Isotope Hydrology Unit located in Vienna. RMs of marine origin, characterised for radionuclides, minor and trace elements and organic contaminants, are prepared by Marine Environment Laboratory located in Monaco. The selection and characterisation of RMs is performed in close co-operation with other Sections in the IAEA including: Nutrition and Health Related Environmental Studies, Industrial Applications and Chemistry, Safeguards Analytical Laboratory and the Agriculture and Biotechnology Laboratory. With the exception of RMs for the determination

  19. Normalization Methods and Selection Strategies for Reference Materials in Stable Isotope Analyes. Review

    International Nuclear Information System (INIS)

    Stable isotope ratio mass spectrometers are highly precise, but not accurate instruments. Therefore, results have to be normalized to one of the isotope scales (e.g., VSMOW, VPDB) based on well calibrated reference materials. The selection of reference materials, numbers of replicates, δ-values of these reference materials and normalization technique have been identified as crucial in determining the uncertainty associated with the final results. The most common normalization techniques and reference materials have been tested using both Monte Carlo simulations and laboratory experiments to investigate aspects of error propagation during the normalization of isotope data. The range of observed differences justifies the need to employ the same sets of standards worldwide for each element and each stable isotope analytical technique. (author)

  20. 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

  1. A summary of chemical and biological testing of proposed disposal of sediment from Richmond Harbor relative to the Deep Off-Shelf Reference Area, the Bay Farm Borrow Area, and the Alcatraz Environs Reference Area

    Energy Technology Data Exchange (ETDEWEB)

    Mayhew, H.L.; Karle, L.M.; Gruendell, B.D.; Pinza, M.R. [Battelle/Marine Sciences Lab., Sequim, WA (United States)

    1993-12-01

    The US Army Corps of Engineers was authorized to dredge Richmond Harbor to accomodate large, deep-draft vessels. An ecological evaluation of the Harbor sediments was performed describing the physical characteristics, toxic substances, effects on aquatic organisms,and potential for bioaccumulation of chemical contaminants. The objective of this report is to compare the sediment chemistry, acute toxicity, and bioaccumulation results of the Richmond Harbor sediments to each of the reference areas; i.e., the Deep Off-Shelf Reference Area, the Bay Farm Borrow Area, and the Alcatraz Environs Reference Area. This report will enable the US Army Corps of Engineers to determine whether disposal at a reference area is appropriate for all or part of the dredged material from Richmond Harbor. Chemical analyses were performed on 30 sediment samples; 28 of those samples were then combined to form 7 composites. The seven composites plus sediment from two additional stations received both chemical and biological evaluations.

  2. FDTD Simulation of Exposure of Biological Material to Electromagnetic Nanopulses

    CERN Document Server

    Simicevic, N; Simicevic, Neven; Haynie, Donald T

    2004-01-01

    Ultra-wideband (UWB) electromagnetic pulses of nanosecond duration, or nanopulses, are of considerable interest to the communications industry and are being explored for various applications in biotechnology and medicine. The propagation of a nanopulse through biological matter has been computed in the time domain using the finite difference-time domain method (FDTD). The approach required existing Cole-Cole model-based descriptions of dielectric properties of biological matter to be re-parametrized using the Debye model, but without loss of accuracy. The approach has been applied to several tissue types. Results show that the electromagnetic field inside a biological tissue depends on incident pulse rise time and width. Rise time dominates pulse behavior inside a tissue as conductivity increases. It has also been found that the amount of energy deposited by 20 $kV/m$ nanopulses is insufficient to change the temperature of the exposed material for the pulse repetition rates of 1 $MHz$ or less.

  3. CHARACTERISATION OF BIOLOGICALLY PRETREATED RAW MATERIALS FOR BIOPULPING PROCESS

    Directory of Open Access Journals (Sweden)

    Susy Albert

    2012-12-01

    Full Text Available Biopulping, the treatment of wood chips by white rot fungi and subsequent chip refining is envisioned as a method for saving energy and making a stronger paper product. The present study aims to find suitability of two fungal isolates Phellinus pectinatus and Daedaleopsis confragosa for the process of biopulping and the characteristion of the biologically pretreated raw materials for biopulping. Two combinations of raw samples, Bamboo: wood shavings and Bamboo: wood shavings: Sorghum halepense culm were prepared and subjected to four different pretreatment. Daedaleopsis confragosa was found to be effective in biopulping with a supplement of Potato dextrose broth medium to the raw material.

  4. Development of methods for determining aflatoxins in biological material

    OpenAIRE

    Kussak, Anders

    1995-01-01

    In this thesis, it is shown how aflatoxins can be determined in biological material. The thesis is a summary of five papers. Aflatoxins are carcinogenic mycotoxins produced by Aspergillus moulds. Methods were developed for the determination of aflatoxins in samples of airborne dust and human urine collected at feed factories. For the dust samples from such agricultural products as copra, cotton seed and maize, methods were developed for the determination of aflatoxins B1, B2, G1 and G2. For u...

  5. CHARACTERISATION OF BIOLOGICALLY PRETREATED RAW MATERIALS FOR BIOPULPING PROCESS

    OpenAIRE

    Susy Albert; Amee Padhiar

    2012-01-01

    Biopulping, the treatment of wood chips by white rot fungi and subsequent chip refining is envisioned as a method for saving energy and making a stronger paper product. The present study aims to find suitability of two fungal isolates Phellinus pectinatus and Daedaleopsis confragosa for the process of biopulping and the characteristion of the biologically pretreated raw materials for biopulping. Two combinations of raw samples, Bamboo: wood shavings and Bamboo: wood shavings: Sorghum halepens...

  6. Standard and reference materials for marine science. Third edition. Technical memo

    International Nuclear Information System (INIS)

    The third edition of the catalog of reference materials suited for use in marine science, originally compiled in 1986 for NOAA, IOC, and UNEP. The catalog lists close to 2,000 reference materials from sixteen producers and contains information about their proper use, sources, availability, and analyte concentrations. Indices are included for elements, isotopes, and organic compounds, as are cross references to CAS registry numbers, alternate names, and chemical structures of selected organic compounds. The catalog is being published independently by both NOAA and IOC/UNEP and is available from NOAA/NOS/ORCA in electronic form

  7. Diffusion theory in biology: a relic of mechanistic materialism.

    Science.gov (United States)

    Agutter, P S; Malone, P C; Wheatley, D N

    2000-01-01

    Diffusion theory explains in physical terms how materials move through a medium, e.g. water or a biological fluid. There are strong and widely acknowledged grounds for doubting the applicability of this theory in biology, although it continues to be accepted almost uncritically and taught as a basis of both biology and medicine. Our principal aim is to explore how this situation arose and has been allowed to continue seemingly unchallenged for more than 150 years. The main shortcomings of diffusion theory will be briefly reviewed to show that the entrenchment of this theory in the corpus of biological knowledge needs to be explained, especially as there are equally valid historical grounds for presuming that bulk fluid movement powered by the energy of cell metabolism plays a prominent note in the transport of molecules in the living body. First, the theory's evolution, notably from its origins in connection with the mechanistic materialist philosophy of mid nineteenth century physiology, is discussed. Following this, the entrenchment of the theory in twentieth century biology is analyzed in relation to three situations: the mechanism of oxygen transport between air and mammalian tissues; the structure and function of cell membranes; and the nature of the intermediary metalbolism, with its implicit presumptions about the intracellular organization and the movement of molecules within it. In our final section, we consider several historically based alternatives to diffusion theory, all of which have their precursors in nineteenth and twentieth century philosophy of science.

  8. Survey of reference materials. V. 1: Biological and environmental reference materials for trace elements, nuclides and microcontaminants

    International Nuclear Information System (INIS)

    Irradiation in combination with other food process/treatments, at sterilizing or at substerilizing doses, has long been known to be capable of yielding shelf-stable foods, particularly dry-packed meat, poultry and fish/shellfish products having very good eating quality and nutritional value. However, other than highly specific, targeted used with astronauts and cosmonauts in space, with immune-suppressed medical patients at one US hospital, and for military feeding plus supplying small nich 'markets' in the Republic of South Africa, there has been no commercial exploitation of the research and development that has gone into establishing this potentially very useful and valuable food irradiation application category. But what with rising global energy costs, and immune-comprised/suppressed populations on the increase, together with increasing consumer demand for minimally processed superior eating quality foods in developed countries especially, the potential and need for industrial use of this largely neglected food irradiation areas is becoming more and more apparent. 8 refs, 12 tabs

  9. 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, ...

  10. 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 ...

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

    International Nuclear Information System (INIS)

    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: 60Co≤4.6%, 134Cs≤4.7%, 137Cs≤5.0%, total β≤0.6% and 3H≤1.3%. - Highlights: • Seven kinds environmental materials were used to establish the production of the RMs. • Spiking the traceable standard radioactive source to the blank substance. • Each sample was carefully evaluated for its uncertainty. • The performance of the RMs was estimated with the Proficiency Testing program report. • The ability of the environment RMs in the configuration is quite good

  12. 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

  13. List of reference materials for non-destructive assay of U, Th and Pu isotopes

    International Nuclear Information System (INIS)

    A list of reference materials for non-destructive assay has been compiled within six countries of the EEC, the Commission and the IAEA with the assistance of the members of the Esarda working group on NDA. The reference materials have been tabulated according to the type of fuel cycle (HEU, LEU, Pu) and type of fuel. For each material the following data are given: the chemical composition, the nominal value or the range in quantity of the element, the U235 enrichment or isotopic composition, the physical form and number of pieces

  14. Report of the research co-ordination meeting on reference materials for microanalytical nuclear techniques

    International Nuclear Information System (INIS)

    Many microanalytical procedure require specific natural-matrix reference materials containing very low levels of trace elements and having a high degree of homogeneity. This proposed CRP will specifically address the question of quality control materials for these techniques. The participants of the meeting discussed the requirements for certified reference materials to by used in microanalysis with particular emphasis on the homogeneity issues. This publication contains summary of the discussions along with conclusions and recommendations made by the participants. The publication also contains 13 individual presentations delivered by the participants. Each of the individual papers has been provided with an abstract and indexed separately

  15. The ChEBI reference database and ontology for biologically relevant chemistry: enhancements for 2013.

    Science.gov (United States)

    Hastings, Janna; de Matos, Paula; Dekker, Adriano; Ennis, Marcus; Harsha, Bhavana; Kale, Namrata; Muthukrishnan, Venkatesh; Owen, Gareth; Turner, Steve; Williams, Mark; Steinbeck, Christoph

    2013-01-01

    ChEBI (http://www.ebi.ac.uk/chebi) is a database and ontology of chemical entities of biological interest. Over the past few years, ChEBI has continued to grow steadily in content, and has added several new features. In addition to incorporating all user-requested compounds, our annotation efforts have emphasized immunology, natural products and metabolites in many species. All database entries are now 'is_a' classified within the ontology, meaning that all of the chemicals are available to semantic reasoning tools that harness the classification hierarchy. We have completely aligned the ontology with the Open Biomedical Ontologies (OBO) Foundry-recommended upper level Basic Formal Ontology. Furthermore, we have aligned our chemical classification with the classification of chemical-involving processes in the Gene Ontology (GO), and as a result of this effort, the majority of chemical-involving processes in GO are now defined in terms of the ChEBI entities that participate in them. This effort necessitated incorporating many additional biologically relevant compounds. We have incorporated additional data types including reference citations, and the species and component for metabolites. Finally, our website and web services have had several enhancements, most notably the provision of a dynamic new interactive graph-based ontology visualization.

  16. The use of BIM reference models for multi-material structural design

    OpenAIRE

    Djedović, Sanel

    2014-01-01

    Master thesis deals with multi-material structural design that is based on reference architectural model. We performed process and product analysis that is relevant for multi-material structural design and proposed and demonstrated its use for three construction materials (concrete, steel and wood) In the frames of process analysis we used IDEFØ methodology to describe AS-IS structural design. A detailed description of process models of existing design procedures for building permit and pr...

  17. Biological nitrogen fixation by faba bean, pea and vetch, using isotopic techniques (N-15) and two reference crops

    International Nuclear Information System (INIS)

    A field experiment was carried out on a Typic Dystrandept soil at Santa Catalina Experimental Station, Cutuglagua, Pichincha, Ecuador. The objectives were to quantify faba bean (Vicia faba) pea (Pisum sativum) and vetch (Vicia sativa) biological nitrogen fixation using N-15 isotopic technique and to evaluate suitability of reference crops for such quantification. Higher values of biological nitrogen fixation were obtained using maize (Zea mays L.) than using wheat (Triticum vurgare) as reference crops. The average values were 85 and 81 per cent for vetch; 73 and 69 per cent for faba bean; and 34 and 18 per cent for pea, respectively. It was assumed that nitrogen use efficiency should be the same for fixing and no fixing crop, but it was observed that a reference crop with low nitrogen use efficiency underestimates legume biological nitrogen fixation. Results suggest that greater caution is needed when selecting reference crops for legumes with low nitrogen fixation

  18. OECD Policy Recommendations on Security for Biological Materials

    International Nuclear Information System (INIS)

    Biomedical innovations derived from research on pathogenic micro-organisms promise astounding health and economic benefits. Some such biological resources employed in the RandD for diagnostic kits, vaccines and therapeutics, however, possess capacity for dual-use; they may be misused to develop biological weapons. Research facilities entrusted with possession of such dual-use materials have a responsibility to comply with biosecurity measures that are designed to prevent loss or theft and thereby reduce the probability of a bioterrorist attack. The OECD has provided a forum for its Member countries to engage in a dialogue of international co-operation with a view to produce policies that achieve a research environment fortified by biosecurity measures and capable of producing health innovations. In 2007, the OECD developed a risk assessment framework and risk management principles for Biological Resource Centres. Ongoing policy work at the OECD will look to design biosecurity guidelines appropriate to a broader range of facilities in possession of dual-use materials, such as university and industrial laboratories.(author)

  19. Interfacing materials science and biology for drug carrier design.

    Science.gov (United States)

    Such, Georgina K; Yan, Yan; Johnston, Angus P R; Gunawan, Sylvia T; Caruso, Frank

    2015-04-01

    Over the last ten years, there has been considerable research interest in the development of polymeric carriers for biomedicine. Such delivery systems have the potential to significantly reduce side effects and increase the bioavailability of poorly soluble therapeutics. The design of carriers has relied on harnessing specific variations in biological conditions, such as pH or redox potential, and more recently, by incorporating specific peptide cleavage sites for enzymatic hydrolysis. Although much progress has been made in this field, the specificity of polymeric carriers is still limited when compared with their biological counterparts. To synthesize the next generation of carriers, it is important to consider the biological rationale for materials design. This requires a detailed understanding of the cellular microenvironments and how these can be harnessed for specific applications. In this review, several important physiological cues in the cellular microenvironments are outlined, with a focus on changes in pH, redox potential, and the types of enzymes present in specific regions. Furthermore, recent studies that use such biologically inspired triggers to design polymeric carriers are highlighted, focusing on applications in the field of therapeutic delivery.

  20. Feasibility Study for the Development of Plutonium Reference Materials for Age Dating in Nuclear Forensics

    International Nuclear Information System (INIS)

    Isotopic reference materials certified for the age of nuclear material (uranium, plutonium) are needed in the fields of nuclear forensics and environmental measurements. Therefore a feasibility study for the development of plutonium reference materials for age dating has been started recently at the Institute for Reference Materials and Measurements (EC-JRC-IRMM). The ''age'' of the material is defined as the time that has passed since the last chemical separation of the mother and daughter isotopes (e.g. 241Pu and 241Am). Assuming that the separation has been complete and all the daughter isotopes have been removed from the original material during this last separation, the age of the material can be determined by measuring the ratio of daughter and mother radio-nuclides, e.g. 241Am/241Pu. At a given time after the last separation and depending on the half lives of the radio-nuclides involved, a certain amount of the daughter radionuclide(s) will be present. For the determination of the unknown age of a material different ''clocks'' can be used; ''clocks'' are pairs of mother and daughter radio-nuclides, such as 241Am/241Pu, 238Pu/234U, 239Pu/235U, 240Pu/236U, and possibly 242Pu/238U. For the age estimation of a real sample, such as material seized in nuclear forensics investigations or dust samples in environmental measurements, it is advisable to use more than one clock in order to ensure the reliability of the results and to exclude the possibility that the sample under question is a mixture of two or more materials. Consequently, a future reference material certified for separation date should ideally be certified for more than one ''clock'' or several reference materials for different ''clocks'' should be developed. The first step of this study is to verify the known separation dates of different plutonium materials of different ages and isotopic compositions by measuring the mother (238Pu, 239Pu, 240Pu, 241Pu, 242Pu) and daughter (234U, 235U, 236U, 238U and

  1. Bioreceptivity evaluation of cementitious materials designed to stimulate biological growth.

    Science.gov (United States)

    Manso, Sandra; De Muynck, Willem; Segura, Ignacio; Aguado, Antonio; Steppe, Kathy; Boon, Nico; De Belie, Nele

    2014-05-15

    Ordinary Portland cement (OPC), the most used binder in construction, presents some disadvantages in terms of pollution (CO2 emissions) and visual impact. For this reason, green roofs and façades have gain considerable attention in the last decade as a way to integrate nature in cities. These systems, however, suffer from high initial and maintenance costs. An alternative strategy to obtain green facades is the direct natural colonisation of the cementitious construction materials constituting the wall, a phenomenon governed by the bioreceptivity of such material. This work aims at assessing the suitability of magnesium phosphate cement (MPC) materials to allow a rapid natural colonisation taking carbonated OPC samples as a reference material. For that, the aggregate size, the w/c ratio and the amount of cement paste of mortars made of both binders were modified. The assessment of the different bioreceptivities was conducted by means of an accelerated algal fouling test. MPC samples exhibited a faster fouling compared to OPC samples, which could be mainly attributed to the lower pH of the MPC binder. In addition to the binder, the fouling rate was governed by the roughness and the porosity of the material. MPC mortar with moderate porosity and roughness appears to be the most feasible material to be used for the development of green concrete walls.

  2. Bioreceptivity evaluation of cementitious materials designed to stimulate biological growth.

    Science.gov (United States)

    Manso, Sandra; De Muynck, Willem; Segura, Ignacio; Aguado, Antonio; Steppe, Kathy; Boon, Nico; De Belie, Nele

    2014-05-15

    Ordinary Portland cement (OPC), the most used binder in construction, presents some disadvantages in terms of pollution (CO2 emissions) and visual impact. For this reason, green roofs and façades have gain considerable attention in the last decade as a way to integrate nature in cities. These systems, however, suffer from high initial and maintenance costs. An alternative strategy to obtain green facades is the direct natural colonisation of the cementitious construction materials constituting the wall, a phenomenon governed by the bioreceptivity of such material. This work aims at assessing the suitability of magnesium phosphate cement (MPC) materials to allow a rapid natural colonisation taking carbonated OPC samples as a reference material. For that, the aggregate size, the w/c ratio and the amount of cement paste of mortars made of both binders were modified. The assessment of the different bioreceptivities was conducted by means of an accelerated algal fouling test. MPC samples exhibited a faster fouling compared to OPC samples, which could be mainly attributed to the lower pH of the MPC binder. In addition to the binder, the fouling rate was governed by the roughness and the porosity of the material. MPC mortar with moderate porosity and roughness appears to be the most feasible material to be used for the development of green concrete walls. PMID:24602907

  3. Advanced Tomography Techniques For Inorganic, Organic, and Biological Materials

    Energy Technology Data Exchange (ETDEWEB)

    Evans, James E.; Friedrich, Heiner

    2016-07-01

    Three-dimensional (3D) tomography using electrons and x-rays has pushed our understanding of the micro- and nanoscale spatial organization for biological, organic and inorganic materials. While significant impact has already been realized from tomography applications, new advanced methods are quickly expanding the versatility of this approach to better link structure, composition and function of complex 3D assemblies across multiple scales. In this article we highlight several frontiers where new developments in tomography are empowering all new science across biology, chemistry and physics. The 5 articles that appear in this MRS Bulletin Issue describe in detail these latest developments in analytical electron tomography, atomic resolution electron tomography, advanced recording schemes in scanning transmission electron (STEM) tomography, cryo-STEM tomography of whole cells, and multiscale correlative tomography.

  4. Development of Reference Materials for Thermal-Diffusivity Measurements by the Flash Method

    Science.gov (United States)

    Akoshima, M.; Abe, H.; Baba, T.

    2015-12-01

    The thermal conductivity of solid materials used for thermal simulations and thermal designs can be obtained as the product of thermal diffusivity, specific heat capacity, and bulk density in many cases. The thermal diffusivity is usually measured by the flash method, and the specific heat capacity is usually measured by differential scanning calorimetry. In order to obtain reliable thermal conductivities for strict thermal design, it is necessary to measure the thermal diffusivity using the flash method, a well-validated apparatus. Reference materials are an effective means for validation of most practical measurement apparatus. For the flash method, isotropic graphite was selected as a candidate reference material. A batch of isotropic graphite samples was prepared and characterized in detail in order to be a certified reference material for thermal-diffusivity measurement. The detailed characterization ensures the traceability of the measurement results to the international system of units (SI). A convenient reference material for thermal conductivity was also obtained by using the known thermal-diffusivity measurements, specific heat capacity, and density of the material.

  5. A mussel (Mytilus edulis) tissue certified reference material for the marine biotoxins azaspiracids

    OpenAIRE

    McCarron, Pearse; Giddings, Sabrina D.; Reeves, Kelley L.; Hess, Philipp; Michael A. Quilliam

    2015-01-01

    Azaspiracids (AZAs) are lipophilic biotoxins produced by marine algae that can contaminate shellfish and cause human illness. The European Union (EU) regulates the level of AZAs in shellfish destined for the commercial market, with liquid chromatography-mass spectrometry (LC-MS) being used as the official reference method for regulatory analysis. Certified reference materials (CRMs) are essential tools for the development, validation, and quality control of LC-MS methods. This paper describes...

  6. Ultrafast electron microscopy in materials science, biology, and chemistry

    International Nuclear Information System (INIS)

    The use of pump-probe experiments to study complex transient events has been an area of significant interest in materials science, biology, and chemistry. While the emphasis has been on laser pump with laser probe and laser pump with x-ray probe experiments, there is a significant and growing interest in using electrons as probes. Early experiments used electrons for gas-phase diffraction of photostimulated chemical reactions. More recently, scientists are beginning to explore phenomena in the solid state such as phase transformations, twinning, solid-state chemical reactions, radiation damage, and shock propagation. This review focuses on the emerging area of ultrafast electron microscopy (UEM), which comprises ultrafast electron diffraction (UED) and dynamic transmission electron microscopy (DTEM). The topics that are treated include the following: (1) The physics of electrons as an ultrafast probe. This encompasses the propagation dynamics of the electrons (space-charge effect, Child's law, Boersch effect) and extends to relativistic effects. (2) The anatomy of UED and DTEM instruments. This includes discussions of the photoactivated electron gun (also known as photogun or photoelectron gun) at conventional energies (60-200 keV) and extends to MeV beams generated by rf guns. Another critical aspect of the systems is the electron detector. Charge-coupled device cameras and microchannel-plate-based cameras are compared and contrasted. The effect of various physical phenomena on detective quantum efficiency is discussed. (3) Practical aspects of operation. This includes determination of time zero, measurement of pulse-length, and strategies for pulse compression. (4) Current and potential applications in materials science, biology, and chemistry. UEM has the potential to make a significant impact in future science and technology. Understanding of reaction pathways of complex transient phenomena in materials science, biology, and chemistry will provide fundamental

  7. 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%.

  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

    dissolved in acid in preparation for anion-exchange chemistry. Pt was recovered from anion-exchange resin in concentrated HNO acid after elution of matrix elements, including the other platinum group elements (PGE), in dilute HCl and HNO 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...... (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...

  9. 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.

  10. 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.

  11. Generation and Characterization of Six Recombinant Botulinum Neurotoxins as Reference Material to Serve in an International Proficiency Test.

    Science.gov (United States)

    Weisemann, Jasmin; Krez, Nadja; Fiebig, Uwe; Worbs, Sylvia; Skiba, Martin; Endermann, Tanja; Dorner, Martin B; Bergström, Tomas; Muñoz, Amalia; Zegers, Ingrid; Müller, Christian; Jenkinson, Stephen P; Avondet, Marc-Andre; Delbrassinne, Laurence; Denayer, Sarah; Zeleny, Reinhard; Schimmel, Heinz; Åstot, Crister; Dorner, Brigitte G; Rummel, Andreas

    2015-12-01

    The detection and identification of botulinum neurotoxins (BoNT) is complex due to the existence of seven serotypes, derived mosaic toxins and more than 40 subtypes. Expert laboratories currently use different technical approaches to detect, identify and quantify BoNT, but due to the lack of (certified) reference materials, analytical results can hardly be compared. In this study, the six BoNT/A1-F1 prototypes were successfully produced by recombinant techniques, facilitating handling, as well as improving purity, yield, reproducibility and biosafety. All six BoNTs were quantitatively nicked into active di-chain toxins linked by a disulfide bridge. The materials were thoroughly characterized with respect to purity, identity, protein concentration, catalytic and biological activities. For BoNT/A₁, B₁ and E₁, serotypes pathogenic to humans, the catalytic activity and the precise protein concentration were determined by Endopep-mass spectrometry and validated amino acid analysis, respectively. In addition, BoNT/A₁, B₁, E₁ and F₁ were successfully detected by immunological assays, unambiguously identified by mass spectrometric-based methods, and their specific activities were assigned by the mouse LD50 bioassay. The potencies of all six BoNT/A1-F1 were quantified by the ex vivo mouse phrenic nerve hemidiaphragm assay, allowing a direct comparison. In conclusion, highly pure recombinant BoNT reference materials were produced, thoroughly characterized and employed as spiking material in a worldwide BoNT proficiency test organized by the EQuATox consortium. PMID:26703728

  12. MAK and BAT values list 2014. Maximum permissible concentrations at the place of work and biological tolerance values for working materials; MAK- und BAT-Werte-Liste 2014. Maximale Arbeitsplatzkonzentrationen und Biologische Arbeitsstofftoleranzwerte

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-11-01

    The book on the MAK (maximum permissible concentrations at the place of work) and BAT (biological tolerance values for working materials) value list 2014 includes the following chapters: (a) Maximum permissible concentrations at the place of work: definition, application and determination of MAT values, list of materials; carcinogenic working materials, sensibilizing working materials, aerosols, limiting the exposition peaks, skin resorption, MAK values during pregnancy, germ cell mutagens, specific working materials; (b) Biological tolerance values for working materials: definition and application of BAT values, list of materials, carcinogenic working materials, biological guide values, biological working material reference values.

  13. MAK and BAT values list 2015. Maximum permissible concentrations at the place of work and biological tolerance values for working materials; MAK- und BAT-Werte-Liste 2015. Maximale Arbeitsplatzkonzentrationen und Biologische Arbeitsstofftoleranzwerte

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-11-01

    The book on the MAK (maximum permissible concentrations at the place of work) and BAT (biological tolerance values for working materials) value list 2015 includes the following chapters: (a) Maximum permissible concentrations at the place of work: definition, application and determination of MAT values, list of materials; carcinogenic working materials, sensibilizing working materials, aerosols, limiting the exposition peaks, skin resorption, MAK values during pregnancy, germ cell mutagens, specific working materials; (b) Biological tolerance values for working materials: definition and application of BAT values, list of materials, carcinogenic working materials, biological guide values, biological working material reference values.

  14. The role of material in homogeneities in biological growth

    Directory of Open Access Journals (Sweden)

    Grillo A.

    2005-01-01

    Full Text Available We investigate the influence of the material in homogeneities that are generated by an isotropic growth on the source of mass acting within a growing living tissue. In order to do that, we need to study the interaction between these material in homogeneities and the chemical agents dissolved within the tissue. For this purpose, we use some ideas and methods from Condensed Matter Physics (e.g., the Path Integral technique employed in modeling Brownian processes and apply them to the Continuum Mechanics description of volumetric Growth. We believe that this approach may provide new physical insight into the interactions between the macroscopic dynamics of living systems and the evolution of the subsystems which activate biological processes.

  15. 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.

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

    International Nuclear Information System (INIS)

    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. (author)

  17. 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.

  18. 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. PMID:27216677

  19. Access and benefit sharing of Antarctica's biological material.

    Science.gov (United States)

    Puig-Marcó, Roser

    2014-10-01

    Searching and sampling of Antarctic Biological Material (ABM) is happening with no explicit regulation on access and benefit sharing requirements. Patents already exist on inventions stemming from Antarctic living organisms. The Antarctic Treaty System (ATS) provides mechanisms to ensure that scientific knowledge and data generated from the collection and use of ABM are shared, although commercialization might be a threat to this free exchange of scientific knowledge. Some of the underlying problems regarding the access and benefit sharing of ABM are that under the ATS there are gaps concerning definitions, access to specimens, benefit sharing, commercialization and reporting issues. The Antarctic Treaty Consultative Parties (ATCPs) have decided that the Antarctic Treaty Consultative Meeting (ATCM) is the competent body to discuss the matter, and the ATS is the appropriate framework for managing the collection of biological material in the Antarctic Treaty area and for considering its use. Nevertheless, opinions diverge as to the need for more specific rules on access and benefit sharing other than that already resulting from the obligation to give prior notification and share scientific results.

  20. Laser-matter structuration of optical and biological materials

    Energy Technology Data Exchange (ETDEWEB)

    Hallo, L., E-mail: hallo@celia.u-bordeaux1.fr [CELIA, Universite Bordeaux 1 (France); Mezel, C., E-mail: candice.mezel@cea.fr [CELIA, Universite Bordeaux 1 (France); CEA Le Ripault, 37260 Monts (France); Guillemot, F., E-mail: fabien.guillemot@inserm.fr [UMR 577 INSERM, Universite Bordeaux 2 (France); Chimier, B., E-mail: chimier@celia.u-bordeaux1.fr [CELIA, Universite Bordeaux 1 (France); Bourgeade, A., E-mail: antoine.bourgeade@cea.fr [CEA-CESTA, Le Barp (France); Regan, C., E-mail: regan@celia.u-bordeaux1.fr [CELIA, Universite Bordeaux 1 (France); Duchateau, G., E-mail: duchateau@celia.u-bordeaux1.fr [CELIA, Universite Bordeaux 1 (France); Souquet, A., E-mail: agnes.souquet@inserm.fr [UMR 577 INSERM, Universite Bordeaux 2 (France); Hebert, D., E-mail: david.hebert@cea.fr [CEA-CESTA, Le Barp (France)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer In this study we model nanomaterial structuring. Black-Right-Pointing-Pointer The laser energy deposition is discussed first. Black-Right-Pointing-Pointer Full and approximate models are discussed. Black-Right-Pointing-Pointer Dynamic material response is addressed via hydrodynamics. Black-Right-Pointing-Pointer Sild effects are accounted for - Abstract: Interaction of ultrafast laser, i.e. from the femtosecond (fs) to the nanosecond (ns) regime, with initially transparent matter may produce very high energy density hot spots in the bulk as well as at the material surface, depending on focusing conditions. In the fs regime, absorption is due to ionisation of the dielectric, which enables absorption process to begin, and then hydrodynamic to take place. In the ns regime both absorption and hydrodynamic are coupled to each other, which complexifies considerably the comprehension but matter structuration looks similar. A numerical tool including solution of 3D Maxwell equations and a rate equation for free electrons is first compared to some available simple models of laser energy absorption. Then, subsequent material deformation, i.e. structuration, is determined by solving hydrodynamic equations, including or not solid behaviour. We show that nature of the final structures strongly depends on the amount of deposited energy and on the shape of the absorption zone. Then we address some problems related to laser-matter structuration of optical and biological materials in the fs, ps and ns regimes.

  1. Testing of IAEA standard reference materials by Research and Development Institute, Czechoslovak Uranium Industry

    International Nuclear Information System (INIS)

    The Institute have partaken of attestations for a number of years. It has thus obtained a number of reference materials and could completely test the accuracy of the analytical methods used. The materials being tested included uranium and thorium ores, milk, whey, sea sediments and algae. The methods used included X-ray fluorescence analysis, high resolution gamma spectrometry, atomic absorption spectrometry, radiometric methods. Uranium was determined by spectrophotometry using Arsenazo III. (M.D.). 2 tabs., 17 refs

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

    OpenAIRE

    Povinec, P.; PHAM M. K.; Busto, J.; Cerna, C.; Degering, D.; Y. Hamajima; Holy, K.; Hult, Mikael; Jeskovsky, M.; Koehler, M; Kovacik, A.; Laubenstein, Matthias; Loaiza, P.; Mamedov, F.; Marquet, C.

    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 certifica...

  3. Combating illicit trafficking in nuclear and other radioactive material. Reference material

    International Nuclear Information System (INIS)

    This publication is intended for individuals and organizations that may be called upon to deal with the detection of and response to criminal or unauthorized acts involving nuclear or other radioactive material. It will also be useful for legislators, law enforcement agencies, government officials, technical experts, lawyers, diplomats and users of nuclear technology. This manual emphasizes the international initiatives for improving the security of nuclear and other radioactive material. However, it is recognized that effective measures for controlling the transfer of equipment, non-nuclear material, technology or information that may assist in the development of nuclear explosive devices, improvised nuclear devices (INDs) or other radiological dispersal devices (RDDs) are important elements of an effective nuclear security system. In addition, issues of personal integrity, inspection and investigative procedures are not discussed in this manual, all of which are essential elements for an effective overall security system. The manual considers a variety of elements that are recognized as being essential for dealing with incidents of criminal or unauthorized acts involving nuclear and other radioactive material. Depending on conditions in a specific State, including its legal and governmental infrastructure, some of the measures discussed will need to be adapted to suit that State's circumstances. However, much of the material can be applied directly in the context of other national programmes. This manual is divided into four main parts. Section 2 discusses the threat posed by criminal or unauthorized acts involving nuclear and other radioactive material, as well as the policy and legal bases underlying the international effort to restrain such activities. Sections 3 and 4 summarize the major international undertakings in the field. Sections 5-8 provide some basic technical information on radiation, radioactive material, the health consequences of radiation

  4. 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.

  5. 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…

  6. The preparation of a reference material of South African zirconium concentrate from Richards Bay

    International Nuclear Information System (INIS)

    This report describes the preparation of a South African zirconium concentrate as an inernational reference material. The procedure for the selection of preferred values is outlined. Eleven laboratories contributed to the analytical programme, and 7 elements have been asssigned preferred values

  7. 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

  8. Analysis of FDA in-house food reference materials with anticoincidence INAA

    International Nuclear Information System (INIS)

    In-house reference material (IRM) cocoa powder (CCP) has been in use at US Food and Drug Administration laboratories for about 15 years. A single lot of commercial material was originally characterized for 32 elements by several laboratories and five techniques. A unique approach for basis weight determination based upon ambient relative humidity was developed for CCP, eliminating the need for dry weight determinations. The CCP Reference Sheet is updated by incorporating new results approximately every 5 years. The last update occurred in 2006. As part of an effort to revalidate and update values for CCP, anticoincidence instrumental neutron activation analysis (INAA) was used to determine mass fractions for 16 of the originally characterized elements, as well as to provide information on 16 other elements. Results were in very good agreement with 2006 Reference Sheet values. A new candidate IRM, fresh-frozen swordfish (FFSF) powder, was produced by adding inorganic As, Cd, Cr, Hg, Pb, Sb, and Se to liquid nitrogen-frozen commercial swordfish filets which were then homogenized. Portions of FFSF were analyzed by INAA to provide mass fraction and homogeneity information for As, Cd, Cr, Hg, Sb, and Se as well as for eight other elements occurring naturally in the material. Non-homogeneities were ≤2.5 % for As, Br, Cd, and Cs, and ≤1.8 % for Cr, Hg, Rb, Sb, and Se. Certified reference materials DORM-3 Fish Protein powder and fresh-frozen SRM 1947 Lake Michigan Fish Tissue were analyzed as controls. (author)

  9. 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...

  10. Elemental determinations in NBS 1633A Fly Ash Standard Reference material using INAA PGNAA

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, J.R.; Schlegel, S.C. (Missouri Univ., Columbia (USA). Research Reactor Facility)

    1985-02-01

    INAA was used for the determination of 23 elements, and prompt gamma neutron activation analysis (PGNAA) for the determination of 10 elements in U.S. National Bureau of Standards (NBS) 1633A Fly Ash Standard Reference Material. The results are in excellent agreement with the limited number of NBS certified values available.

  11. Biology Teacher and Expert Opinions about Computer Assisted Biology Instruction Materials: A Software Entitled Nucleic Acids and Protein Synthesis

    Science.gov (United States)

    Hasenekoglu, Ismet; Timucin, Melih

    2007-01-01

    The aim of this study is to collect and evaluate opinions of CAI experts and biology teachers about a high school level Computer Assisted Biology Instruction Material presenting computer-made modelling and simulations. It is a case study. A material covering "Nucleic Acids and Protein Synthesis" topic was developed as the "case". The goal of the…

  12. Spatio-structural granularity of biological material entities

    Directory of Open Access Journals (Sweden)

    Vogt Lars

    2010-05-01

    -structural granularity framework for all domain reference ontologies that model cumulative-constitutively organized material entities. With its multi-perspectives approach it allows querying an ontology stored in a database at one's own desired different levels of detail: The contents of a database can be organized according to diverse granularity perspectives, which in their turn provide different views on its content (i.e. data, knowledge, each organized into different levels of detail.

  13. 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.

  14. Reference methods and materials. A programme of support for regional and global marine pollution assessments

    International Nuclear Information System (INIS)

    This document describes a programme of comprehensive support for regional and global marine pollution assessments developed by the United Nations Environment Programme (UNEP) in cooperation with the International Atomic Energy Agency (IAEA) and the Intergovernmental Oceanographic Commission (IOC) and with the collaboration of a number of other United Nations Specialized agencies including the Food and Agriculture Organisation (FAO), the World Meteorological Organisation (WMO), the World Health Organisation (WHO) and the International Maritime Organisation (IMO). Two of the principle components of this programme, Reference Methods and Reference materials are given special attention in this document and a full Reference Method catalogue is included, giving details of over 80 methods currently available or in an advanced stage of preparation and testing. It is important that these methods are seen as a functional component of a much wider strategy necessary for assuring good quality and intercomparable data for regional and global pollution monitoring and the user is encouraged to read this document carefully before employing Reference Methods and Reference Materials in his/her laboratory. 3 figs

  15. Determination of cadmium, lead and zinc in a candidate reference materials using isotope dilution mass spectrometry

    International Nuclear Information System (INIS)

    The growing demands placed on analytical laboratories to ensure the reliability of their results, due to the introduction of systems of quality and to the increasing use of metrology in chemical measurements has led most laboratories to validate their methodologies and to control them statistically. One of the techniques used most often for these purposes is based on the use of reference materials. The proper use of these materials means that laboratory results may be traced to the International System of Units, analytical methodologies can be validated, instruments calibrated and chemical measurements harmonized. One of the biggest challenges in developing reference materials is that of certifying their properties, a process that has been defined as assigning a concentration value that is as close as possible to the true value together with its uncertainty. Organizations that produce reference materials use several options for their certification process, and among these is the use of a primary method. Among the primary methods recognized by the International Office of Weights and Measures is the Isotope Dilution Mass Spectrometry technique. The Chilean Nuclear Energy Commission, through its Reference Materials Program, has prepared a reference material of clam tissue, which has been chemically defined by different analytical methodologies applied in different national and international laboratories. This work describes the methodology developed with the CIEMAT for determining the elements lead, cadmium and zinc in the clam tissue reference material using the primary technique of Isotope Dilution Mass Spectrometry. The calculation is described for obtaining the spike amounts to be added to the sample and the procedure is explained for carrying out the isotopic exchange. The isotopic relationships 204Pb/205Pb, 111Cd/114Cd and 66Zn/67Zn were determined in an atomic emission spectrometer with a plasma source with the following characteristics: plasma ionization

  16. The High-Strain Rate Loading of Structural Biological Materials

    Science.gov (United States)

    Proud, W. G.; Nguyen, T.-T. N.; Bo, C.; Butler, B. J.; Boddy, R. L.; Williams, A.; Masouros, S.; Brown, K. A.

    2015-10-01

    The human body can be subjected to violent acceleration as a result of explosion caused by military ordinance or accident. Blast waves cause injury and blunt trauma can be produced by violent impact of objects against the human body. The long-term clinical manifestations of blast injury can be significantly different in nature and extent to those suffering less aggressive insult. Similarly, the damage seen in lower limbs from those injured in explosion incidents is in general more severe than those falling from height. These phenomena increase the need for knowledge of the short- and long-term effect of transient mechanical loading to the biological structures of the human body. This paper gives an overview of some of the results of collaborative investigation into blast injury. The requirement for time-resolved data, appropriate mechanical modeling, materials characterization and biological effects is presented. The use of a range of loading platforms, universal testing machines, drop weights, Hopkinson bars, and bespoke traumatic injury simulators are given.

  17. Determination of operationally defined fractions of aluminium in reference materials and acid attacked environmental samples

    International Nuclear Information System (INIS)

    The aim of the presented work is to evaluate the selectivity of the operationally defined procedures for the aluminium fractionation in the reference materials and the environmental samples affected by the mining activity. The combination of the sequential optimized BCR (European Commission Community Bureau of Reference) three-step, the single (H2O, CaCl2, Na2S2O4, NH4F (NH4)2C2O4, HCl, NTA, EDTA, DTPA) and the solid phase chelating ion-exchange extraction procedures was performed for the aluminium fractionation in the samples. The amount of the reactive Al determined by the solid phase extraction on the chelating resin Iontosorb Salicyl is the most important operationally defined fraction of aluminium from the aspect of its negative effects on the environment. The available Al concentrations obtained from the different operationally defined fractionation methods were compared. The flame atomic absorption spectrometry was used for the aluminium quantification. The X-ray diffraction analyse of the samples was performed for the mineral composition determination. The precision, the repeatability and the accuracy for the all steps of the optimized BCR sequential extraction procedure were checked on six reference materials (SRM 2710, RSS SO-2, RSS SO-4, CRM SA-B, SRM RTH 912, CRM 025-050). The precision and the repeatability were very good with the R.S.D. values 11%. The fraction specific accuracy was excellent. The new indicative fractional Al values in the used reference materials are published

  18. IMOS National Reference Stations: A Continental-Wide Physical, Chemical and Biological Coastal Observing System

    Science.gov (United States)

    Lynch, Tim P.; Morello, Elisabetta B.; Evans, Karen; Richardson, Anthony J.; Rochester, Wayne; Steinberg, Craig R.; Roughan, Moninya; Thompson, Peter; Middleton, John F.; Feng, Ming; Sherrington, Robert; Brando, Vittorio; Tilbrook, Bronte; Ridgway, Ken; Allen, Simon; Doherty, Peter; Hill, Katherine; Moltmann, Tim C.

    2014-01-01

    Sustained observations allow for the tracking of change in oceanography and ecosystems, however, these are rare, particularly for the Southern Hemisphere. To address this in part, the Australian Integrated Marine Observing System (IMOS) implemented a network of nine National Reference Stations (NRS). The network builds on one long-term location, where monthly water sampling has been sustained since the 1940s and two others that commenced in the 1950s. In-situ continuously moored sensors and an enhanced monthly water sampling regime now collect more than 50 data streams. Building on sampling for temperature, salinity and nutrients, the network now observes dissolved oxygen, carbon, turbidity, currents, chlorophyll a and both phytoplankton and zooplankton. Additional parameters for studies of ocean acidification and bio-optics are collected at a sub-set of sites and all data is made freely and publically available. Our preliminary results demonstrate increased utility to observe extreme events, such as marine heat waves and coastal flooding; rare events, such as plankton blooms; and have, for the first time, allowed for consistent continental scale sampling and analysis of coastal zooplankton and phytoplankton communities. Independent water sampling allows for cross validation of the deployed sensors for quality control of data that now continuously tracks daily, seasonal and annual variation. The NRS will provide multi-decadal time series, against which more spatially replicated short-term studies can be referenced, models and remote sensing products validated, and improvements made to our understanding of how large-scale, long-term change and variability in the global ocean are affecting Australia's coastal seas and ecosystems. The NRS network provides an example of how a continental scaled observing systems can be developed to collect observations that integrate across physics, chemistry and biology. PMID:25517905

  19. IMOS National Reference Stations: a continental-wide physical, chemical and biological coastal observing system.

    Directory of Open Access Journals (Sweden)

    Tim P Lynch

    Full Text Available Sustained observations allow for the tracking of change in oceanography and ecosystems, however, these are rare, particularly for the Southern Hemisphere. To address this in part, the Australian Integrated Marine Observing System (IMOS implemented a network of nine National Reference Stations (NRS. The network builds on one long-term location, where monthly water sampling has been sustained since the 1940s and two others that commenced in the 1950s. In-situ continuously moored sensors and an enhanced monthly water sampling regime now collect more than 50 data streams. Building on sampling for temperature, salinity and nutrients, the network now observes dissolved oxygen, carbon, turbidity, currents, chlorophyll a and both phytoplankton and zooplankton. Additional parameters for studies of ocean acidification and bio-optics are collected at a sub-set of sites and all data is made freely and publically available. Our preliminary results demonstrate increased utility to observe extreme events, such as marine heat waves and coastal flooding; rare events, such as plankton blooms; and have, for the first time, allowed for consistent continental scale sampling and analysis of coastal zooplankton and phytoplankton communities. Independent water sampling allows for cross validation of the deployed sensors for quality control of data that now continuously tracks daily, seasonal and annual variation. The NRS will provide multi-decadal time series, against which more spatially replicated short-term studies can be referenced, models and remote sensing products validated, and improvements made to our understanding of how large-scale, long-term change and variability in the global ocean are affecting Australia's coastal seas and ecosystems. The NRS network provides an example of how a continental scaled observing systems can be developed to collect observations that integrate across physics, chemistry and biology.

  20. Millimeter wave and terahertz dielectric properties of biological materials

    Science.gov (United States)

    Khan, Usman Ansar

    Broadband dielectric properties of materials can be employed to identify, detect, and characterize materials through their unique spectral signatures. In this study, millimeter wave, submillimeter wave, and terahertz dielectric properties of biological substances inclusive of liquids, solids, and powders were obtained using Dispersive Fourier Transform Spectroscopy (DFTS). Two broadband polarizing interferometers were constructed to test materials from 60 GHz to 1.2 THz. This is an extremely difficult portion of the frequency spectrum to obtain a material's dielectric properties since neither optical nor microwave-based techniques provide accurate data. The dielectric characteristics of liquids such as cyclohexane, chlorobenzene, benzene, ethanol, methanol, 1,4 dioxane, and 10% formalin were obtained using the liquid interferometer. Subsequently the solid interferometer was utilized to determine the dielectric properties of human breast tissues, which are fixed and preserved in 10% formalin. This joint collaboration with the Tufts New England Medical Center demonstrated a significant difference between the dielectric response of tumorous and non-tumorous breast tissues across the spectrum. Powders such as anthrax, flour, talc, corn starch, dry milk, and baking soda have been involved in a number of security threats and false alarms around the globe in the last decade. To be able to differentiate hoax attacks and serious security threats, the dielectric properties of common household powders were also examined using the solid interferometer to identify the powders' unique resonance peaks. A new sample preparation kit was designed to test the powder specimens. It was anticipated that millimeter wave and terahertz dielectric characterization will enable one to clearly distinguish one powder from the other; however most of the powders had relatively close dielectric responses and only Talc had a resonance signature recorded at 1.135 THz. Furthermore, due to

  1. Analyze of histopathelogical for medical devices and biological material on biocompatibility evaluation

    Institute of Scientific and Technical Information of China (English)

    NIE Wei; JIANG Hua; WANG Li; GUAN Jing-fang; SHI Hong-dao

    2001-01-01

    @@ The toxicity and biocompatibility of medical devices and biological material areprominent facts in evaluation of the material. There are two major methods to evaluate the biocompatibility of biological materials . one kind is to do vivo. The materialor extracts are used to study the effect of the material on the growth, metabolismand proliferation of the histocyte.

  2. 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.

  3. Preparation, characterization and use of a reference material to proficiency testing for determination of metals in fish tissue in natura

    International Nuclear Information System (INIS)

    The proficiency tests are widely used to evaluate the analytical capacity of laboratories and also as part of the accreditation process. For this reason, are important tools for the control of the quality of the analytical results obtained in the laboratories that work directly with seafood companies. In Brazil there are no providers of proficiency testing for metals potentially toxic in fish tissues. In this work will be described all steps used for the production of reference materials to be used in a proficiency testing pilot study for As, Cd, Pb and Hg in fish tissue following the recommendations of the ISO Guide 35. He preparation scheme consisted in selecting the individuals, cleaning, grinding, homogenization and fortification with As, Cd and Pb in two concentration levels. The preparation resulted in 164 sachets of 10 g each. In order to evaluate the effect of gamma irradiation in the samples conservation 52 sachets were irradiated with 60Co (10.00 ± 1.05 kGy) in a gamma cell. This material with others non irradiated 52 sachets were used for the homogeneity and stability studies. The remaining 60 were used for the proficiency testing. The results demonstrated that both materials were homogeneous and presented good stability (during a period of 45 days). However, the irradiated material present better integrity, concerning biological degradation, when stored in ambient temperature. For this reason they were used to the proficiency testing pilot program. Ten laboratories participated in the proficiency testing pilot study and the results were evaluated using the following tests: z-score, confidence ellipse and En numbers. This work demonstrates the capability of the laboratory to produce reference materials as well as to organize and conduct proficiency testing. (author)

  4. Standard guide for preparation of working reference materials for use in analysis of nuclear fuel cycle materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2001-01-01

    1.1 This guide covers the preparation and characterization of working reference materials (WRM) that are produced by a laboratory for its own use in the analysis of nuclear materials. Guidance is provided for establishing traceability of WRMs to certified reference materials by a defined characterization process. The guidance provided is generic; it is not specific for a given material. 1.2 The information provided by this guide is found in the following sections: Section Planning 6 Preparation 7 Packaging and Storage 8 Characterization 9 Statistical Analysis 10 Documentation 11 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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.

  5. PROTECTION OF WOODEN MATERIALS AGAINST BIOLOGICAL ATTACK BY USING NANOTECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Michal Havrlik

    2015-04-01

    Full Text Available This article is focused on protection of wooden materials by using nanofibrous textiles with biocidal addition, which continues on the work of a group at the Center for Nanotechnology at the Faculty of Civil Engineering in the CTU. Timber is a natural material which is predisposed for biodegradation and therefore it is essential to study suitable and effective protection against microorganisms. Wood is a material susceptible to biological corrosion and therefore it is necessary to protect it. The study compares biocidal efficiency of polymer solution as a coating and as a layer from nanofiber textiles. We used polyvinyl alcohol (PVA as a basic polymer which was enriched by substances from commercial Lignofix E – profi, solution of CuSO4 · 5H2O and AgNO3 and finally colloidal silver as an example of nanoparticles. The final concentration of the biocidal substance was 1 (v/wt% in fiber. The nanofiber textiles are produced on the device Nanospider NS LAB 500 (Elmarco, CR on cylinder rotating electrode. The study was divided into two parts, the first being an agar plate test and the second a test on samples from timber. The mixture of mold was used as the model organism. (Alternaria tenuissima, Pochonia bulbiosa, Trichoderma viride and Acremonium sclerotigenum. Comparison of efficiency between the polymer paint and nanofiber textiles showed no difference. The best results were shown by PVA with an addition of substances from the commercial biocidal treatment Lignofix-E Profi on the agar plate. The difference of result was shown on timbre samples, finding that the best results were with treatment by PVA doped by Silver nitrate. The anticipated results were shown by treatment with non-doped PVA, which does not have any fungicidal protective effect.

  6. Prompt gamma activation analysis of boron in reference materials using diffracted polychromatic neutron beam

    International Nuclear Information System (INIS)

    Boron concentrations were analyzed for standard reference materials by prompt gamma activation analysis (PGAA). The measurements were performed at the SNU-KAERI PGAA facility installed at Hanaro, the research reactor of Korea Atomic Energy Research Institute (KAERI). The facility uses a diffracted polychromatic beam with a neutron flux of 7.9 x 107 n/cm2 s. Elemental sensitivity for boron was calibrated from the prompt gamma-ray spectra of boric acid samples containing 2-45 μg boron. The sensitivity of 2131 cps/mg-B was obtained from the linearity of the boron peak count rate versus the boron mass. The detection limit for boron was estimated to be 67 ng from an empty sample bag spectrum for a counting time of 10,000 s. The measured boron concentrations for standard reference materials showed good consistency with the certified or information values

  7. Analysis of soil reference materials for vanadium(+5) species by electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Solid Certified Reference Materials (CRMs) with known vanadium(+5) content are currently not commercially available. Because of this, vanadium species have been determined in solid CRMs of soil, viz. CRM023-50, CRM024-50, CRM049-50, SQC001 and SQC0012. These CRMs are certified with only total vanadium content. Vanadium(+5) was extracted from soil reference materials with 0.1 M Na2CO3. The quantification of V(+5) was carried out by electrothermal atomic absorption spectrometry (ET-AAS). The concentration of V(+5) in the analyzed CRMs was found to be ranging between 3.60 and 86.0 μg g-1. It was also found that SQC001 contains approximately 88% of vanadium as V(+5) species. Statistical evaluation of the results of the two methods by paired t-test was in good agreement at 95% level of confidence.

  8. Prompt gamma activation analysis of boron in reference materials using diffracted polychromatic neutron beam

    Science.gov (United States)

    Byun, S. H.; Sun, G. M.; Choi, H. D.

    2004-01-01

    Boron concentrations were analyzed for standard reference materials by prompt gamma activation analysis (PGAA). The measurements were performed at the SNU-KAERI PGAA facility installed at Hanaro, the research reactor of Korea Atomic Energy Research Institute (KAERI). The facility uses a diffracted polychromatic beam with a neutron flux of 7.9 × 10 7 n/cm 2 s. Elemental sensitivity for boron was calibrated from the prompt gamma-ray spectra of boric acid samples containing 2-45 μg boron. The sensitivity of 2131 cps/mg-B was obtained from the linearity of the boron peak count rate versus the boron mass. The detection limit for boron was estimated to be 67 ng from an empty sample bag spectrum for a counting time of 10,000 s. The measured boron concentrations for standard reference materials showed good consistency with the certified or information values.

  9. Evaluation of the Community's research programme ''Nuclear measurements and reference materials'' (1980-1985)

    International Nuclear Information System (INIS)

    A panel has evaluated the research programme ''Nuclear measurements and reference materials'' performed by JRC-Geel, CBNM (Central Bureau for Nuclear Measurements) during the period 1980-85. Furthermore the panel has considered more general topics such as major facilities, staff and collaboration between JRC-Geel, CBNM and other organizations. Finally, the panel has discussed the future direction of the programme. The panel expressed its satisfaction with the scientific and technical quality of the work and recommended that JRC-Geel, CBNM should continue to play an important role in Europe in the fields of nuclear measurements and nuclear reference materials. The panel also recommended that the underlying research be strengthened and that the nuclear experience and expertise of JRC-Geel, CBNM be utilized for non-nuclear applications

  10. 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. PMID:11583083

  11. Multielement analysis of environmental reference materials by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Concentrations of trace elements in environmental reference materials prepared by the National Institute for Environmental Studies, Japan (NIES) and by the National Institute of Standards and Technology, USA (NIST) were determined by instrumental neutron activation analysis (INAA). NIES CRM No. 5 Human Hair, No. 6 Mussel, No. 7 Tea Leaves, No. 8 Vehicle Exhaust Particulates, No. 9 Sargasso and No. 10 Rice Flour-unpolished samples (ca. 150 - 1200 mg) and NIST SRM 1632a Bituminous Coal, SRM 1635 Sub-bituminous Coal and SRM 1633a Coal Fly Ash samples (ca. 10 - 150 mg) were irradiated at the Musashi Institute of Technology Research Reactor (MITRR). Concentrations of 28 - 52 elements in these NIES and NIST environmental reference materials were determined by two irradiation methods and four γ-ray counting methods. The determined values were in good agreement with the NIES and NIST certified values. (author)

  12. Imaging of nonthrombotic pulmonary embolism: biological materials, nonbiological materials, and foreign bodies.

    Science.gov (United States)

    Bach, Andreas Gunter; Restrepo, Carlos Santiago; Abbas, Jasmin; Villanueva, Alberto; Lorenzo Dus, María José; Schöpf, Reinhard; Imanaka, Hideaki; Lehmkuhl, Lukas; Tsang, Flora Hau Fung; Saad, Fathinul Fikri Ahmad; Lau, Eddie; Rubio Alvarez, Jose; Battal, Bilal; Behrmann, Curd; Spielmann, Rolf Peter; Surov, Alexey

    2013-03-01

    Nonthrombotic pulmonary embolism is defined as embolization to the pulmonary circulation caused by a wide range of substances of endogenous and exogenous biological and nonbiological origin and foreign bodies. It is an underestimated cause of acute and chronic embolism. Symptoms cover the entire spectrum from asymptomatic patients to sudden death. In addition to obstruction of the pulmonary vasculature there may be an inflammatory cascade that deteriorates vascular, pulmonary and cardiac function. In most cases the patient history and radiological imaging reveals the true nature of the patient's condition. The purpose of this article is to give the reader a survey on pathophysiology, typical clinical and radiological findings in different forms of nonthrombotic pulmonary embolism. The spectrum of forms presented here includes pulmonary embolism with biological materials (amniotic fluid, trophoblast material, endogenous tissue like bone and brain, fat, Echinococcus granulosus, septic emboli and tumor cells); nonbiological materials (cement, gas, iodinated oil, glue, metallic mercury, radiotracer, silicone, talc, cotton, and hyaluronic acid); and foreign bodies (lost intravascular objects, bullets, catheter fragments, intraoperative material, radioactive seeds, and ventriculoperitoneal shunts). PMID:23102488

  13. 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...... for 12 other radionuclides (90Sr, 99Tc, 210Pb (210Po), 226Ra, 228Ra, 228Th, 230Th, 232Th, 235U, 238U, 239Pu and 240Pu) are presented. The CRM can be used for Quality Assurance/Quality Control of analysis of radionuclides in seaweed and other biota samples, as well as for development and validation...

  14. 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)

  15. 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.

  16. Development of benzene, toluene, ethylbenzene and xylenes certified gaseous reference materials

    Science.gov (United States)

    Brum, M. C.; Sobrinho, D. C. G.; Fagundes, F. A.; Oudwater, R. J.; Augusto, C. R.

    2016-07-01

    The work describes the production of certified gaseous reference materials of benzene, toluene, ethylbenzene and xylenes (BTEX) in nitrogen from the gravimetric production up to the long term stability tests followed by the certifying step. The uncertainty in the amount fractions of the compounds in these mixtures was approximately 4% (relative) for the range studied from 2 to 16 µmol/mol. Also the adsorption of the BTEX on the cylinder surface and the tubing were investigated as potential uncertainty source.

  17. The NIMROC reference materials: revised values for thorium, yttrium, lanthanum, and the rare-earth elements

    International Nuclear Information System (INIS)

    This report gives all the analytical results submitted by the contributing laboratories before July 1983 for thorium, yttrium, lanthanum, and the rare-earth elements in the six NIMROC reference materials (SARM 1 to 6), which were prepared in 1966 by the former National Institute for Metallurgy, now the Council for Mineral Technology (Mintek). The statistical evaluation of these results and the assignment of new or revised recommended or provisional values are described

  18. 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.

  19. Certified reference material IAEA-418: I-129 in Mediterranean sea water

    International Nuclear Information System (INIS)

    Our society is attaching increasing importance to the study and assessment of the state and health of the environment. Organizations involved in such activities rely on the quality of the information provided and, ultimately, on the precision and accuracy of the data on which the information is based. Many laboratories are involved in the production of environmental data in many cases leading to wider assessments. These laboratories may develop and validate new analytical methods, study the environmental impact of human activities, provide services to other organizations, etc. In particular, laboratories are providing data on levels of radioactivity in a variety of marine matrixes such as water, suspended matter, sediments and biota. Because of the need to base scientific conclusions on valid and internationally comparable data, the need to provide policy makers with correct information and the need for society to be informed of the state of the environment, it is indispensable to ensure the quality of the data produced by each laboratory. Principles of good laboratory practice require both internal and external procedures to verify the quality of the data produced. Internal quality is verified in a number of ways such as the use of laboratory information systems, keeping full records of equipment performance and standardization of analytical procedures. External quality can also be ascertained in a number of ways, notably accreditation by an external body under a defined quality scheme but also, amongst others, the use of internationally accepted calibration standards that are traceable to the SI international system of units, the participation in interlaboratory comparisons or the regular use of reference materials to test laboratory performance. The Radiometrics Laboratory of the IAEA Marine Environment Laboratories has been providing quality products for the last 40 years which include the organization of interlaboratory comparisons, proficiency tests

  20. A reference material for establishing uncertainties in full-field displacement measurements

    International Nuclear Information System (INIS)

    A simple reference material for establishing the minimum measurement uncertainty of optical systems for measuring 3D surface displacement fields in deforming objects is described and its use demonstrated by employing 3D digital image correlation as an exemplar technique. The reference material consists of a stepped bar, whose dimensions can be scaled to suit the application, and that can be clamped rigidly at its thick end to create an idealized cantilever. The cantilever was excited at resonance to generate out-of-plane displacements and, in a separate experiment, loaded statically in-plane to provide in-plane displacement fields. The displacements were measured using 3D digital image correlation and compared to the predicted displacement fields derived from tip deflections obtained using a calibrated transducer that provided traceability to the national standard for length. The minimum measurement uncertainties were evaluated by comparing the measured and predicted displacement fields, taking account of the uncertainties in the input parameters for the predictions. It was found that the minimum measurement uncertainties were less than 3% for the Cartesian components of displacement present during static in-plane bending and less than 3 µm for out-of-plane displacements during dynamic loading. It was concluded that this reference material was more straightforward to use, more versatile and yielded comparable results relative to an earlier design. (paper)

  1. Generation and Characterization of Six Recombinant Botulinum Neurotoxins as Reference Material to Serve in an International Proficiency Test

    Directory of Open Access Journals (Sweden)

    Jasmin Weisemann

    2015-11-01

    Full Text Available The detection and identification of botulinum neurotoxins (BoNT is complex due to the existence of seven serotypes, derived mosaic toxins and more than 40 subtypes. Expert laboratories currently use different technical approaches to detect, identify and quantify BoNT, but due to the lack of (certified reference materials, analytical results can hardly be compared. In this study, the six BoNT/A1–F1 prototypes were successfully produced by recombinant techniques, facilitating handling, as well as improving purity, yield, reproducibility and biosafety. All six BoNTs were quantitatively nicked into active di-chain toxins linked by a disulfide bridge. The materials were thoroughly characterized with respect to purity, identity, protein concentration, catalytic and biological activities. For BoNT/A1, B1 and E1, serotypes pathogenic to humans, the catalytic activity and the precise protein concentration were determined by Endopep-mass spectrometry and validated amino acid analysis, respectively. In addition, BoNT/A1, B1, E1 and F1 were successfully detected by immunological assays, unambiguously identified by mass spectrometric-based methods, and their specific activities were assigned by the mouse LD50 bioassay. The potencies of all six BoNT/A1–F1 were quantified by the ex vivo mouse phrenic nerve hemidiaphragm assay, allowing a direct comparison. In conclusion, highly pure recombinant BoNT reference materials were produced, thoroughly characterized and employed as spiking material in a worldwide BoNT proficiency test organized by the EQuATox consortium.

  2. Development of a certified reference material for genetically modified potato with altered starch composition.

    Science.gov (United States)

    Broothaerts, Wim; Corbisier, Philippe; Emons, Hendrik; Emteborg, Håkan; Linsinger, Thomas P J; Trapmann, Stefanie

    2007-06-13

    The presence of genetically modified organisms (GMOs) in food and feed products is subject to regulation in the European Union (EU) and elsewhere. As part of the EU authorization procedure for GMOs intended for food and feed use, reference materials must be produced for the quality control of measurements to quantify the GMOs. Certified reference materials (CRMs) are available for a range of herbicide- and insect-resistant genetically modified crops such as corn, soybean, and cotton. Here the development of the first CRM for a GMO that differs from its non-GMO counterpart in a major compositional constituent, that is, starch, is described. It is shown that the modification of the starch composition of potato (Solanum tuberosum L.) tubers, together with other characteristics of the delivered materials, have important consequences for the certification strategy. Moreover, the processing and characterization of the EH92-527-1 potato material required both new and modified procedures, different from those used routinely for CRMs produced from genetically modified seeds. PMID:17508757

  3. 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. PMID:24102115

  4. 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.

  5. Testing the homogeneity of candidate reference materials by solid sampling - AAS and INAA

    International Nuclear Information System (INIS)

    The necessity to quantify a natural material's homogeneity with respect to its elemental distribution prior to chemical analysis of a given aliquot is emphasised. Available instruments and methods to obtain the relevant information are described. Additionally the calculation of element specific, relative homogeneity factors, HE, and of a minimum sample mass M5% to achieve 5% precision on a 95% confidence level is given. Especially, in the production and certification of Certified Reference Materials (CRMs) this characteristic information should be determined in order to provide the user with additional inherent properties of the CRM to enable more economical use of the expensive material and to evaluate further systematic bias of the applied analytical technique. (author)

  6. Quality assessment of organic coffee beans for the preparation of a candidate reference material

    International Nuclear Information System (INIS)

    A random sampling was carried out in the coffee beans collected for the preparation of the organic green coffee reference material in view of assessing the homogeneity and the presence of soil as impurity. Fifteen samples were taken for the between-sample homogeneity evaluation. One of the samples was selected and 10 test portions withdrawn for the within-sample homogeneity evaluation. Br, Ca, Co, Cs, Fe, K, Na, Rb, Sc and Zn were determined by instrumental neutron activation analysis (INAA). The F-test demonstrated that the material is homogeneous for Ca, Co, Cs, K and Sc, but not homogeneous for Br, Fe, Na, Rb and Zn. Results of terrigenous elements suggested negligible soil contamination in the raw material. (author)

  7. Reference Material Kydex(registered trademark)-100 Test Data Message for Flammability Testing

    Science.gov (United States)

    Engel, Carl D.; Richardson, Erin; Davis, Eddie

    2003-01-01

    The Marshall Space Flight Center (MSFC) Materials and Processes Technical Information System (MAPTIS) database contains, as an engineering resource, a large amount of material test data carefully obtained and recorded over a number of years. Flammability test data obtained using Test 1 of NASA-STD-6001 is a significant component of this database. NASA-STD-6001 recommends that Kydex 100 be used as a reference material for testing certification and for comparison between test facilities in the round-robin certification testing that occurs every 2 years. As a result of these regular activities, a large volume of test data is recorded within the MAPTIS database. The activity described in this technical report was undertaken to mine the database, recover flammability (Test 1) Kydex 100 data, and review the lessons learned from analysis of these data.

  8. Giant and universal magnetoelectric coupling in soft materials and concomitant ramifications for materials science and biology.

    Science.gov (United States)

    Liu, Liping; Sharma, Pradeep

    2013-10-01

    Magnetoelectric coupling-the ability of a material to magnetize upon application of an electric field and, conversely, to polarize under the action of a magnetic field-is rare and restricted to a rather small set of exotic hard crystalline materials. Intense research activity has recently ensued on materials development, fundamental scientific issues, and applications related to this phenomenon. This tantalizing property, if present in adequate strength at room temperature, can be used to pave the way for next-generation memory devices such as miniature magnetic random access memories and multiple state memory bits, sensors, energy harvesting, spintronics, among others. In this Rapid Communication, we prove the existence of an overlooked strain mediated nonlinear mechanism that can be used to universally induce the giant magnetoelectric effect in all (sufficiently) soft dielectric materials. For soft polymer foams-which, for instance, may be used in stretchable electronics-we predict room-temperature magnetoelectric coefficients that are comparable to the best known (hard) composite materials created. We also argue, based on a simple quantitative model, that magnetoreception in some biological contexts (e.g., birds) most likely utilizes this very mechanism.

  9. On the status of IAEA delta-13C stable isotope reference materials.

    Science.gov (United States)

    Assonov, Sergey; Groening, Manfred; Fajgelj, Ales

    2016-04-01

    For practical reasons all isotope measurements are performed on relative scales realized through the use of international, scale-defining primary standards. In fact these standards were materials (artefacts, similar to prototypes of meter and kg) selected based on their properties. The VPDB delta-13C scale is realised via two highest-level reference materials NBS19 and LSVEC, the first defining the scale and the second aimed to normalise lab-to-lab calibrations. These two reference materials (RMs) have been maintained and distributed by IAEA and NIST. The priority task is to maintain these primary RMs at the required uncertainty level, thus ensuring the long-term scale consistency. The second task is to introduce replacements when needed (currently for exhausted NBS19, work in progress). The next is to produce a family of lower level RMs (secondary, tertiary) addressing needs of various applications (with different delta values, in different physical-chemical forms) and their needs for the uncertainty; these RMs should be traceable to the highest level RMs. Presently three is a need for a range of RMs addressing existing and newly emerging analytical techniques (e.g. optical isotopic analysers) in form of calibrated CO2 gases with different delta-13C values. All that implies creating a family of delta-13C stable isotope reference materials. Presently IAEA works on replacement for NBS19 and planning new RMs. Besides, we found that LSVEC (introduced as second anchor for the VPDB scale in 2006) demonstrate a considerable scatter of its delta-13C value which implies a potential bias of the property value and increased value uncertainty which may conflict with uncertainty requirements for atmospheric monitoring. That is not compatible with the status of LSVEC, and therefore it should be replaced as soon as possible. The presentation will give an overview of the current status, the strategic plan of developments and the near future steps.

  10. Development of botanical and fish oil standard reference materials for fatty acids.

    Science.gov (United States)

    Schantz, Michele M; Sander, Lane C; Sharpless, Katherine E; Wise, Stephen A; Yen, James H; NguyenPho, Agnes; Betz, Joseph M

    2013-05-01

    As part of a collaboration with the National Institutes of Health's Office of Dietary Supplements and the Food and Drug Administration's Center for Drug Evaluation and Research, the National Institute of Standards and Technology has developed Standard Reference Material (SRM) 3274 Botanical Oils Containing Omega-3 and Omega-6 Fatty Acids and SRM 3275 Omega-3 and Omega-6 Fatty Acids in Fish Oil. SRM 3274 consists of one ampoule of each of four seed oils (3274-1 Borage (Borago officinalis), 3274-2 Evening Primrose (Oenothera biennis), 3274-3 Flax (Linium usitatissimum), and 3274-4 Perilla (Perilla frutescens)), and SRM 3275 consists of two ampoules of each of three fish oils (3275-1 a concentrate high in docosahexaenoic acid, 3275-2 an anchovy oil high in docosahexaenoic acid and eicosapentaenoic acid, and 3275-3 a concentrate containing 60% long-chain omega-3 fatty acids). Each oil has certified and reference mass fraction values for up to 20 fatty acids. The fatty acid mass fraction values are based on results from analyses using gas chromatography with flame ionization detection (GC-FID) and mass spectrometry (GC/MS). These SRMs will complement other reference materials currently available with mass fractions for similar analytes and are part of a series of SRMs being developed for dietary supplements. PMID:23371533

  11. Biological nitrogen fixation in common bean and faba bean using N-15 methodology and two reference crops

    International Nuclear Information System (INIS)

    A field was conducted on a Typic ustropepts soil located at 'La Tola', the experimental campus of the Agricultural Sciences Faculty at Tumbaco, Ecuador. The objectives were to quantify faba bean (Vicia faba) and common bean (Phaseolus vulgaris) biological nitrogen fixation, using quinoa (chenopodium quinoa) and maize (Zea mays) as reference crops. The average values were 80 and 70 per cent for faba bean and 42 and 14 per cent for common bean, respectively. It was assumed that nitrogen use eficiency was the same for fixing crops but observed that a crop with high nitrogen use efficiency overestimates legume biological nitrogen fixation. Results suggests that greater caution is needed when selecting reference crops for legumes with nitrogen fixation

  12. Biological Diversity of Created Forested Wetlands in Comparison to Reference Forested Wetlands in the Bay Watershed

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Amphibians, reptiles, birds, and mammals were surveyed at six created forested wetlands in central Maryland and at six adjacent reference forested wetlands during...

  13. Reference waste forms and packing material for the Nevada Nuclear Waste Storage Investigations Project

    International Nuclear Information System (INIS)

    The Lawrence Livermore National Laboratory (LLNL), Livermore, Calif., has been given the task of designing and verifying the performance of waste packages for the Nevada Nuclear Waste Storage Investigations (NNWSI) Project. NNWSI is studying the suitability of the tuffaceous rocks at Yucca Mountain, Nevada Test Site, for the potential construction of a high-level nuclear waste repository. This report gives a summary description of the three waste forms for which LLNL is designing waste packages: spent fuel, either as intact assemblies or as consolidated fuel pins, reprocessed commercial high-level waste in the form of borosilicate glass, and reprocessed defense high-level waste from the Defense Waste Processing Facility in Aiken, S.C. Reference packing material for use with the alternative waste package design for spent fuel is also described. 14 references, 8 figures, 20 tables

  14. Standard reference material certification: contribution of NAA with a TRIGA reactor

    International Nuclear Information System (INIS)

    Pavia has cooperative links with the major international agencies devoted to the certification of SRMs or CRMs as the Bureau Communautaire de Reference (BCR), the European Institute for Reference Materials and Measurement (IRMM), the USA National Institute of Standards and Technology (NIST) and the International Atomic Energy Agency (IAEA). During these cooperative works, a large amount of analytical data obtained with NAA has been compared, and meaningful methodological information achieved with respect to accuracy and precision in the analysis of several elements at different concentrations in various matrices. Analytical data on As, Cd, Cr, Co, Cu, Cs, Fe, Zn, K, Sc, U, Th, Al, Sb, Mn, V, Hg, Sr, Rb, Se,Pt, all the Rare Earths and halogens Br, Cl, I, have been obtained and contributed for the final certification

  15. Report of the consultants meeting on proper use of reference and control materials

    International Nuclear Information System (INIS)

    Quality control in analytical laboratories as a basis of a complete quality system needs still to be developed in many Member States. To support the dissemination of information in this field a consultants meeting on 'Proper Use of Reference and Quality Control Materials' was held at the IAEA Headquarters, Vienna, from 13 to 17 August 2001. The experts convened with the objective to prepare a TECDOC to advise analytical laboratories in Member States on the correct use of Certified Reference Materials (CRMs) for Quality Control purposes and give practical recommendations to expand this concept to in-house Quality Control Materials (QCMs). In view of the existing literature in this field an urgent need for a practical guidebook for the preparation and application of cost effective and matrix matching QCMs was identified and the experts tried to fill this gap from their relevant experience. One and a half days of lecturing was followed by intensive discussion and brain storming to create a list of key words, which were structured in a logical order to provide a frame for the projected document. Responsibilities were assigned and deadlines fixed for the submission of the full text. (author)

  16. 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)

  17. Certified Reference Material IAEA-448: Soil from Oil Field Contaminated with Technically Enhanced Radium-226

    International Nuclear Information System (INIS)

    To ensure reliable evaluation of potential radiological hazards and proper decision making related to radiation protection measures, the IAEA, through the IAEA Environment Laboratories, supports Member State laboratories in their efforts to maintain readiness and to improve the quality of analytical results. It does so by producing reference materials, by developing standardized methods for sample collection and analysis, and by conducting interlaboratory comparisons and proficiency tests as tools for external quality control of analytical results. The problem of naturally occurring radioactive material (NORM) contamination is known to be widespread, occurring in oil and gas production facilities throughout the world. It has become a subject of attention in many IAEA Member States. In response to this radiological concern, facilities in many Member States have been characterizing the nature and extent of NORM in oil and gas installations and in the surrounding environment, evaluating the potential for exposure to workers and the public, and developing methods for properly managing these relatively high massic activity residues. Within this context, the IAEA Environment Laboratories, in cooperation with the Atomic Energy Commission of Syria, an IAEA Collaborating Centre, have prepared a new certified reference material of soil contaminated with NORM, identified as IAEA-448, certified for the massic activity of 226Ra. This report presents the methodologies used for the production and certification of IAEA-448

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

    International Nuclear Information System (INIS)

    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)

  19. Organization and diffusion in biological and material fabrication problems

    Science.gov (United States)

    Mangan, Niall Mari

    This thesis is composed of two problems. The first is a systems level analysis of the carbon concentrating mechanism in cyanobacteria. The second presents a theoretical analysis of femtosecond laser melting for the purpose of hyperdoping silicon with sulfur. While these systems are very distant, they are both relevant to the development of alternative energy (production of biofuels and methods for fabricating photovoltaics respectively). Both problems are approached through analysis of the underlying diffusion equations. Cyanobacteria are photosynthetic bacteria with a unique carbon concentrating mechanism (CCM) which enhances carbon fixation. A greater understanding of this mechanism would offer new insights into the basic biology and methods for bioengineering more efficient biochemical reactions. The molecular components of the CCM have been well characterized in the last decade, with genetic analysis uncovering both variation and commonalities in CCMs across cyanobacteria strains. Analysis of CCMs on a systems level, however, is based on models formulated prior to the molecular characterization. We present an updated model of the cyanobacteria CCM, and analytic solutions in terms of the various molecular components. The solutions allow us to find the parameter regime (expression levels, catalytic rates, permeability of carboxysome shell) where carbon fixation is maximized and oxygenation is minimized. Saturation of RuBisCO, maximization of the ratio of CO2 to O2, and staying below or at the saturation level for carbonic anhydrase are all needed for maximum efficacy. These constraints limit the parameter regime where the most effective carbon fixation can occur. There is an optimal non-specific carboxysome shell permeability, where trapping of CO2 is maximized, but HCO3 - is not detrimentally restricted. The shell also shields carbonic anhydrase activity and CO2 → HCO3- conversion at the thylakoid and cell membrane from one another. Co-localization of carbonic

  20. Thermoelectric needle probe for temperature measurements in biological materials.

    Science.gov (United States)

    Korn, U; Rav-Noy, Z; Shtrikman, S; Zafrir, M

    1980-04-01

    In certain biological and medical applications it is important to measure and follow temperature changes inside a body or tissue. Any probe inserted into a tissue causes damage to tissue and distortion to the initial temperature distribution. To minimize this interference, a fine probe is needed. Thus, thin film technology is advantageous and was utilized by us to produce sensitive probes for these applications. The resulting probe is a small thermocouple at the tip of a thin needle (acupuncture stainless steel needle, approximately 0.26 mm in diameter and length in the range 5-10 cm was used). The junction was produced at the needle's tip by coating the needle with thin layers of insulating and thermoelectric materials. The first layer is an insulating one and is composed of polyacrylonitrile (PAN) and polymide produced by plasma polymerization and dip-coating respectively. This layer covers all the needle except the tip. The second layer is a vacuum deposited thermoelectric thin layer of Bi-5% Sb alloy coating also the tip. The third layer is for insulation and protection and is composed of PAN and polyimide. In this arrangement the junction is at the needle's tip, the needle is one conductor, the thermoelectric layer is the other and they are isolated by the plastic layer. The probe is handy and mechanically sturdy. The sensitivity is typically 77 microV/degrees C at room temperature and is constant to within 2% up to 90 degrees C. The response is fast (less than 1 sec) the noise is small, (less than 0.05 degrees C) and because of the small dimension, damage to tissue and disturbance to the measured temperature field are minimal. PMID:7382928

  1. Value determination of ZrO2 in-house reference material (RM) candidate

    International Nuclear Information System (INIS)

    The value determination of zirconium oxide in-house reference materials (RM) candidate has been done by referring to ISO:35-2006 standard. The raw material of RM was 4 kg of ZrO2, Merck, that was dried at 90°C for 2×6 hours in a closed room. The samples were crushed with stainless steel (SS) pestle to pass ≤ 200 mesh sieve, homogenized in a homogenizer for 3×6 hours to obtain the powdered, dried and homogenous samples. The gravimetric method was performed to test the moisture content, while XRF and AAS methods were used to test the homogeneity and stability of samples candidates. Reference material (RM) candidates of ZrO2 powder were put into polyethylene bottles, each weighing 100 g. Samples were distributed to 10 testing laboratories that have been accredited for testing the composition of the oxide contents and loss of ignition (LOI) using variety of analytical methods that have been validated such as AAS, XRF, NAA, and UV-Vis. The testing results of oxide content and loss of ignition parameters from various laboratories were analyzed using statistical methods. The testing data of oxide concentration in zirconium oxide RM candidates obtained from various laboratories were ZrO2: 97.7334 ± 0.0016%, HfO2: 1.7329 ± 0.0024%, SiO2: 30.1224 ± 0.0053%, Al2O3: 0.0245 ± 0.0015%, TiO2: 0.0153 ± 0.0006%, Fe2O3: 0.0068 ± 0.0005%, CdO: 3.1798 ± 0.00006 ppm, and the LOI results was = 0.0217 ± 0.00022%. (author)

  2. 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.

  3. Certified reference materials of agricultural products and foods bearing radioactivity from the Fukushima nuclear accident

    International Nuclear Information System (INIS)

    Certified reference materials (CRMs) for food analysis were developed in an inter-laboratory experiment for validation of measurement of radiocesium in foodstuffs. Since 2012, five series of CRMs were developed, including for brown rice grain, soybean powder, beef flake, shiitake mushroom powder and marine fish (meat and bone parts). This paper discusses the strategy of development, including choice of CRMs developed and the preparation and certification procedures applied for CRM development. In particular, some detailed data are presented for the most popular CRMs developed: brown rice grain, soybean powder and beef flake. (author)

  4. DNA copy number concentration measured by digital and droplet digital quantitative PCR using certified reference materials

    OpenAIRE

    CORBISIER Philippe; Pinheiro, Leonardo; Mazoua, Stephane; KORTEKAAS Anna Maria; CHUNG PUI YAN JENNY; GERGANOVA TSVETELINA IVANOVA; Roebben, Gert; Emons, Hendrik; Emslie, K

    2015-01-01

    The value assignment for properties of six certified reference materials (ERM-AD623a–f), each containing a plasmid DNA solution ranging from 1 million to 10 copies per μL, by using digital PCR (dPCR) with the BioMark™ HD System (Fluidigm) has been verified by applying droplet digital PCR (ddPCR) using the QX100 system (Bio-Rad). One of the critical factors in the measurement of copy number concentrations by digital PCR is the partition volume. Therefore, we determined the average droplet volu...

  5. 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...... values on massic activities with 95% confidence intervals are given for four radionuclides (230Th, 232Th, 239Pu and 240Pu). Results for less frequently reported radionuclides (99Tc, 228Th, 237Np and 241Pu) are also reported. The CRM can be used for quality assurance/quality control of the analysis...

  6. Preparation of homogeneous thorium oxide powders for development of certified reference materials

    International Nuclear Information System (INIS)

    In view of the growing importance of Thorium Oxide (ThO2) as a fuel in nuclear power reactors, it is essential to develop Certified Reference Materials (CRMs) for trace level assay of ThO2 in order to validate analytical methods and also to assess the performance of an individual chemical laboratory. The present paper discusses the preparation of four batches of homogeneous Thorium Oxide (ThO2) powders on kilogram levels including a batch of ThO2 and Natural UO2 mixed oxide with varying amounts of impurities and also developing them as CRMs based on round robin tests. (author)

  7. Distinguishability of Biological Material Using Ultraviolet Multi-Spectral Fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Gray, P.C.; Heinen, R.J.; Rigdon, L.D.; Rosenthal, S.E.; Shokair, I.R.; Siragusa, G.R.; Tisone, G.C.; Wagner, J.S.

    1998-10-14

    Recent interest in the detection and analysis of biological samples by spectroscopic methods has led to questions concerning the degree of distinguishability and biological variability of the ultraviolet (W) fluorescent spectra from such complex samples. We show that the degree of distinguishability of such spectra is readily determined numerically.

  8. Deciphering the language between biological and synthetic materials

    Directory of Open Access Journals (Sweden)

    Paolo Antonio Netti

    2014-06-01

    Full Text Available Chemical signals propagating through aqueous environment are at the basis of the language utilized by living systems to exchange information. In the last years, molecular biology has partly disclosed the grammar and the syntax of this complex language revealing the fascinating world of molecular communication that is the foundation of biological development.

  9. Soil contamination in plant samples and in botanical reference materials. Signature, quantification and consequences

    International Nuclear Information System (INIS)

    Individual samples of several sets of plants (lichens, tobacco, spruce needles, grass, botanical reference materials) show highly significant correlations of Al, Fe, Hf, La, Na, Th, Ti and V with Sc. These correlations result from the terrigenous part of aerosols deposited on and measured together with the plants. The composition of this contamination is almost uniform among the different plant sets and can be approximated by the composition of the upper continental crust. The mass of the terrigenous material ranges from 100 mg/g plant. Its presence is expected to lead to concentrations of the above and of other elements that deviate substantially from those of plants without contamination. This is proved by the comparison of two sets of spruce needles, one of which was measured without and the other after removal of the aerosol. (author)

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

    International Nuclear Information System (INIS)

    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 239+240Pu radionuclides were certified for this material, and information values for 12 other radionuclides (90Sr, 99Tc, 210Pb (210Po), 226Ra, 228Ra, 228Th, 230Th, 232Th, 235U, 238U, 239Pu and 240Pu) are presented. The CRM can be used for Quality Assurance/Quality Control of analysis of radionuclides in seaweed and other biota samples, as well as for development and validation of analytical methods, and for training purposes

  11. 1984 EC enquiry into the needs for nuclear reference materials (Z>89)

    International Nuclear Information System (INIS)

    For years now, experts in the nuclear field have expressed and pointed out the widespread need for Nuclear Reference Materials (NRMs) in the whole of the nuclear fuel cycle. NRMs were defined as actinides with well-characterized chemical, isotopic and/or physical properties for use as a common base for the calibration of instruments and checking of analytical methods. Since nuclear energy from fission reactors is an increasing contributor to the electricity generating capacity in the EC, there is an equivalent demand for accurate analytical measurements in the various stages of the fuel cycle and in associated fields such as: commercial transactions, production control, nuclear material accounting (safeguards), waste disposal, environmental and health physics, research and development. An essential element for improving analyses and measurements is the availability and use of the appropriate NRMs

  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. 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. PMID:20665007

  14. Integrated multilaboratory systems biology reveals differences in protein metabolism between two reference yeast strains

    NARCIS (Netherlands)

    Canelas, A.B.; Harrison, N.; Fazio, A.; Zhang, J.; Pitkänen, J.P.; Brink, J. van den; Bakker, B.M.; Bogner, L.; Bouwman, J.; Castrillo, J.I.; Cankorur, A.; Chumnanpuen, P.; Daran-Lapujade, P.; Dikicioglu, D.; Eunen, K. van; Ewald, J.C.; Heijnen, J.J.; Kirdar, B.; Mattila, I.; Mensonides, F.I.; Niebel, A.; Penttilä, M.; Pronk, J.T.; Reuss, M.; Salusjärvi, L.; Sauer, U.; Sherman, D.; Siemann-Herzberg, M; Westerhoff, H.; Winde, J.de; Petranovic, D.; Oliver, S.G.; Workman, C.T.; Zamboni, N.; Nielsen, J.

    2010-01-01

    The field of systems biology is often held back by difficulties in obtaining comprehensive, high-quality, quantitative data sets. In this paper, we undertook an interlaboratory effort to generate such a data set for a very large number of cellular components in the yeast Saccharomyces cerevisiae, a

  15. Development of human protein reference database as an initial platform for approaching systems biology in humans

    DEFF Research Database (Denmark)

    Peri, Suraj; Navarro, J Daniel; Amanchy, Ramars;

    2003-01-01

    Human Protein Reference Database (HPRD) is an object database that integrates a wealth of information relevant to the function of human proteins in health and disease. Data pertaining to thousands of protein-protein interactions, posttranslational modifications, enzyme/substrate relationships, di...

  16. Utilizing a reference material for assessing absolute tumor mechanical properties in modality independent elastography

    Science.gov (United States)

    Kim, Dong Kyu; Weis, Jared A.; Yankeelov, Thomas E.; Miga, Michael I.

    2014-03-01

    There is currently no reliable method for early characterization of breast cancer response to neoadjuvant chemotherapy (NAC) [1,2]. Given that disruption of normal structural architecture occurs in cancer-bearing tissue, we hypothesize that further structural changes occur in response to NAC. Consequently, we are investigating the use of modalityindependent elastography (MIE) [3-8] as a method for monitoring mechanical integrity to predict long term outcomes in NAC. Recently, we have utilized a Demons non-rigid image registration method that allows 3D elasticity reconstruction in abnormal tissue geometries, making it particularly amenable to the evaluation of breast cancer mechanical properties. While past work has reflected relative elasticity contrast ratios [3], this study improves upon that work by utilizing a known stiffness reference material within the reconstruction framework such that a stiffness map becomes an absolute measure. To test, a polyvinyl alcohol (PVA) cryogel phantom and a silicone rubber mock mouse tumor phantom were constructed with varying mechanical stiffness. Results showed that an absolute measure of stiffness could be obtained based on a reference value. This reference technique demonstrates the ability to generate accurate measurements of absolute stiffness to characterize response to NAC. These results support that `referenced MIE' has the potential to reliably differentiate absolute tumor stiffness with significant contrast from that of surrounding tissue. The use of referenced MIE to obtain absolute quantification of biomarkers is also translatable across length scales such that the characterization method is mechanics-consistent at the small animal and human application.

  17. 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.

  18. 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.

  19. Determination of arsenic in food and dietary supplement standard reference materials by neutron activation analysis

    International Nuclear Information System (INIS)

    Arsenic was measured in food and dietary supplement standard reference materials by neutron activation analysis for the purpose of assigning certified or reference As mass fractions and to assess material homogeneity. Instrumental neutron activation analysis was used to value assign As in candidate SRM 3532 Calcium Dietary Supplement and candidate SRM 3262 Hypericum perforatum (St. John's Wort) Aerial Parts down to about 100 μg/kg. Values were also determined for two additional candidate St. John's Wort SRMs with As mass fractions 24Na and 82Br limited the reproducibility of the method below 100 μg/kg. For measurement of lower As mass fractions, a radiochemical neutron activation analysis method with extraction of As3+ into diethyl-dithiocarbamate in chloroform and detection limits down to 0.1 μg/kg. As was used to value-assign As mass fractions for SRM 3280 Multivitamin/Multielement Tablets and for candidate SRM 3233 Fortified Breakfast Cereal, and at <10 μg/kg in candidate SRM 1845a Whole Egg Powder. (author)

  20. 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.

  1. 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.

  2. Production of trace elements in coastal sea water certified reference material NMIA MX014.

    Science.gov (United States)

    Merrick, Jeffrey P; Saxby, David L; White, Ian E A W; Antin, Luminita; Murby, E John

    2016-06-01

    A certified reference material (CRM) for trace elements in acidified sea water, NMIA MX014, has been produced by the National Measurement Institute Australia (NMIA). The CRM consists of natural coastal sea water with 12 elements (As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se and V) fortified to levels relevant to environmental regulatory testing in Australia ranging from 0.4 to 22 μg/kg. Certified values for these 12 elements were assigned using reference methods developed at NMIA, using either isotope dilution or standard addition with ICP-MS measurement. Specialised sample preparation (coprecipitation) and ICP-MS optimisation (online dilution, collision/reaction chemistry, high mass resolution) were used to negate the effect of the high level of dissolved solids. Multiple confirmatory experiments were performed in order to verify that ICP-MS spectral interferences were eliminated and to estimate the measurement uncertainty contribution from method precision and method trueness. Extensive homogeneity and stability testing was performed and the measurement uncertainty of certified values includes contributions from between-bottle homogeneity, short-term stability, medium-term stability and long-term stability. Special attention was paid to the stability of Hg due to well-known preservation problems. Acidified sea water matrix was satisfactory for stabilising Hg at 0.4 μg/kg for at least 4 years. Relative expanded uncertainties (k = 2) for the 12 certified values were between 1 and 11 %. NMIA MX014 is intended for use as a reference material for analytical method validation and quality control for quantification of trace elements in saline water and other similar sample types. PMID:27108283

  3. An Experimental Evaluation of the Effectiveness of the Biological Sciences Curriculum Study Special Materials Approach to Teaching Biology to the Slow Learner.

    Science.gov (United States)

    Welford, John Mack

    Students (comparable in intelligence and ability) in slow-learning classes using either "Biological Sciences Curriculum Study (BSCS) Special Materials" or some other slow-learner biology materials, were compared on the basis of scores on the "Nelson Biology Test", the "Biological Sciences; Patterns and Processes Final Examination", and two short…

  4. Certified Reference Materials for Radioactivity Measurements in Environmental Samples of Soil and Water: IAEA-444 and IAEA-445

    International Nuclear Information System (INIS)

    Reference Materials are an important requirement for any sort of quantitative chemical and radiochemical analysis. Laboratories need them for calibration and quality control throughout their analytical work. The IAEA started to produce reference materials in the early 1960's to meet the needs of the analytical laboratories in its Member States that required reference materials for quality control of their measurements. The initial efforts were focused on the preparation of environmental reference materials containing anthropogenic radionuclides for use by those laboratories employing nuclear analytical techniques. These reference materials were characterized for their radionuclide content through interlaboratory comparison involving a core group of some 10 to 20 specialist laboratories. The success of these early exercises led the IAEA to extend its activities to encompass both terrestrial and marine reference materials containing primordial radionuclides and trace elements. Within the frame of IAEA activities in production and certification of reference materials, this report describes the certification of the IAEA-444 and IAEA-445: soil and water spiked with gamma emitting radionuclides respectively. Details are given on methodologies and data evaluation

  5. Development of Analyses of Biological Steroids Using Chromatography--Special Reference to Vitamin D Compounds and Neurosteroids--

    Institute of Scientific and Technical Information of China (English)

    Kazutake Shimada; Tatsuya Higashi; Kuniko Mitamura

    2003-01-01

    Steroids comprise a large group of natural substances that must frequently be monitored in various biological materials. Due to the metabolic versatility of steroid molecules, extremely complex mixtures are often encountered, necessitating the use of a chromatographic procedure prior to measurement. In this article we present our work, that is, the development of analyses of biological steroids (especially vitamin D compounds and neurosteroids) using gas chromatography/mass spectrometry, high-performance liquid chromatography (including inclusion chromatography using cyclodextrin) and liquid chromatography/mass spectrometry.

  6. Body mass and body weight: a dual reference system in biology Masa y peso corporales: un sistema dual de referencia en biología

    OpenAIRE

    BRUNO GÜNTHER; ENRIQUE MORGADO

    2003-01-01

    ABSTRACT The aim of the present study was to compare two different biological similarity criteria, one was based on body mass (M) as a theoretical reference system in accordance with the MLT-system of physics, while the other utilized the body weight (W) for the same purpose. The mass-dependent allometry should be applied during space flights as well as during fetal and newborn conditions of life, whereas the weight-dependence should prevail in earth-bound physiology. The above mentioned dist...

  7. Method And System For Examining Biological Materials Using Low Power Cw Excitation Raman Spectroscopy.

    Energy Technology Data Exchange (ETDEWEB)

    Alfano, Robert R. (Bronx, NY); Wang, Wubao (Flushing, NY)

    2003-05-06

    A method and system for examining biological materials using low-power cw excitation Raman spectroscopy. A low-power continuous wave (cw) pump laser beam and a low-power cw Stokes (or anti-Stokes) probe laser beam simultaneously illuminate a biological material and traverse the biological material in collinearity. The pump beam, whose frequency is varied, is used to induce Raman emission from the biological material. The intensity of the probe beam, whose frequency is kept constant, is monitored as it leaves the biological material. When the difference between the pump and probe excitation frequencies is equal to a Raman vibrational mode frequency of the biological material, the weak probe signal becomes amplified by one or more orders of magnitude (typically up to about 10.sup.4 -10.sup.6) due to the Raman emission from the pump beam. In this manner, by monitoring the intensity of the probe beam emitted from the biological material as the pump beam is varied in frequency, one can obtain an excitation Raman spectrum for the biological material tested. The present invention may be applied to in the in vivo and/or in vitro diagnosis of diabetes, heart disease, hepatitis, cancers and other diseases by measuring the characteristic excitation Raman lines of blood glucose, cholesterol, serum glutamic oxalacetic transaminase (SGOT)/serum glutamic pyruvic transaminase (SGPT), tissues and other corresponding Raman-active body constituents, respectively.

  8. Trends in United States Biological Materials Oversight and Institutional Biosafety Committees

    Science.gov (United States)

    Jenkins, Chris

    2014-01-01

    Biological materials oversight in life sciences research in the United States is a challenging endeavor for institutions and the scientific, regulatory compliance, and federal communities. In order to assess biological materials oversight at Institutional Biosafety Committees (IBCs) registered with the United States National Institutes of Health,…

  9. Determination of zinc stable isotopes in biological materials using isotope dilution inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    A method is described for using isotope dilution to determine both the amount of natural zinc and enriched isotopes of zinc in biological samples. Isotope dilution inductively coupled plasma mass spectrometry offers a way to quantify not only the natural zinc found in a sample but also the enriched isotope tracers of zinc. Accurate values for the enriched isotopes and natural zinc are obtained by adjusting the mass count rate data for measurable instrumental biases. Analytical interferences from the matrix are avoided by extracting the zinc from the sample matrix using diethylammonium diethyldithiocarbamate. The extraction technique separates the zinc from elements which form interfering molecular ions at the same nominal masses as the zinc isotopes. Accuracy of the method is verified using standard reference materials. The detection limit is 0.06 μg Zn per sample. Precision of the abundance ratios range from 0.3-0.8%. R.S.D. for natural zinc concentrations is about 200-600 μg g-1. The accuracy and precision of the measurements make it possible to follow enriched isotopic tracers of zinc in biological samples in metabolic tracer studies. (author). 19 refs.; 1 fig., 4 tabs

  10. 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.

  11. On the nesting biology of Pirhosigma Giordani Soika (Hymenoptera, Vespidae, Eumeninae, with special reference to the use of vegetable matter

    Directory of Open Access Journals (Sweden)

    Marcel G. Hermes

    2013-12-01

    Full Text Available On the nesting biology of Pirhosigma Giordani Soika (Hymenoptera, Vespidae, Eumeninae, with special reference to the use of vegetable matter. The use of vegetable matter in nest building is not widespread among the Eumeninae, and is reported for the first time for the two species of potter wasps Pirhosigma superficiale and P. limpidum. These wasps make mostly spherical mud nests over which they attach small pieces of unmasticated plant matter. Use of plant fragments in this group of wasps is interpreted as camouflage behavior.

  12. Near-infrared spectroscopy and hyperspectral imaging: non-destructive analysis of biological materials.

    Science.gov (United States)

    Manley, Marena

    2014-12-21

    Near-infrared (NIR) spectroscopy has come of age and is now prominent among major analytical technologies after the NIR region was discovered in 1800, revived and developed in the early 1950s and put into practice in the 1970s. Since its first use in the cereal industry, it has become the quality control method of choice for many more applications due to the advancement in instrumentation, computing power and multivariate data analysis. NIR spectroscopy is also increasingly used during basic research performed to better understand complex biological systems, e.g. by means of studying characteristic water absorption bands. The shorter NIR wavelengths (800-2500 nm), compared to those in the mid-infrared (MIR) range (2500-15 000 nm) enable increased penetration depth and subsequent non-destructive, non-invasive, chemical-free, rapid analysis possibilities for a wide range of biological materials. A disadvantage of NIR spectroscopy is its reliance on reference methods and model development using chemometrics. NIR measurements and predictions are, however, considered more reproducible than the usually more accurate and precise reference methods. The advantages of NIR spectroscopy contribute to it now often being favoured over other spectroscopic (colourimetry and MIR) and analytical methods, using chemicals and producing chemical waste, such as gas chromatography (GC) and high performance liquid chromatography (HPLC). This tutorial review intends to provide a brief overview of the basic theoretical principles and most investigated applications of NIR spectroscopy. In addition, it considers the recent development, principles and applications of NIR hyperspectral imaging. NIR hyperspectral imaging provides NIR spectral data as a set of images, each representing a narrow wavelength range or spectral band. The advantage compared to NIR spectroscopy is that, due to the additional spatial dimension provided by this technology, the images can be analysed and visualised as

  13. Assembling new technologies at the interface of materials science and biology

    Science.gov (United States)

    Stendahl, John C.

    Molecular self-assembly can be used to construct advanced materials by taking cues from nature and harnessing noncovalent interactions. This bottom-up approach affords molecular level precision that can cultivate pathways to improved materials function. The graduate research presented in this thesis integrates molecular self-assembly with traditional concepts in chemistry and materials science, with the ultimate goal of developing innovative solutions in technology and medicine. In the field of polymer engineering, self-assembly was used to create supramolecular nanoribbons that, when incorporated into polystyrene, modify its microstructure and significantly enhance its toughness and ductility. In medicine, self-assembly was used to create ordered, chemically functional materials to improve interactions with cells and other constituents of the biological environment. One system that was investigated is based on a triblock molecule in which cholesterol is connected to a lysine dendron by a flexible oligo-(L-lactic acid) spacer. These molecules self-assemble into polar surface coatings on fibrous poly(L-lactic acid) scaffolds that improve the scaffold's wettability and increase its retention of cells during seeding. Another self-assembling system that was investigated for biomedical applications is a family of molecules referred to as peptide amphiphiles (PA's). PA's consist of hydrophobic alkyl tails connected to short, hydrophilic peptides that incorporate biological signaling epitopes. These molecules spontaneously assemble into networks of well-defined nanofibers in aqueous environments, with the signaling epitopes presented in high density on the nanofiber exteriors. Nanofiber assembly is triggered by charge screening on the peptides and is able to produce self-supporting gels in concentrations of less than 1.0 wt.-%. The assembly process and mechanical properties of PA gels was investigated in detail with vibrational spectroscopy and oscillatory rheology. PA

  14. The Elemental Analysis of Biological and Environmental Materials Using a 2MEV Proton Beam

    Science.gov (United States)

    Arshed, Waheed

    Available from UMI in association with The British Library. A programme has been developed to simulate the proton induced x-ray emission (PIXE) spectra and its uses have been described. The PIXE technique has been applied to the analysis of new biological reference materials which consist of IAEA human diet samples and NIST leaf samples. Homogeneity of these and two existing reference materials, IAEA soil -7 and Bowen's kale, has also been determined at the mug scale. A subsample representative of a material is ascertained by determination of sampling factors for the elements detected in the material. Proton induced gamma-ray emission (PIGE) analysis in conjunction with PIXE has been employed to investigate F and other elemental concentrations found in human teeth samples. The mean F concentration in enamel and dentine parts of teeth followed an age dependent model. Concentrations of Ca and P were found to be higher in the enamel than in the dentine. Analysis of blood and its components in the study of elemental models in sickle cell disease in Nigerians has been carried out. Comparisons revealed that Cl, Ca and Cu were at higher levels whereas K, Fe, Zn and Rb were at lower levels in the whole blood of the sicklers compared to controls. Similar results were obtained for the erythrocytes except that Br was found at higher concentration in erythrocytes of the sicklers. Higher concentrations of Cl, K, Fe and Cu were also observed in plasma of the sicklers compared to controls. PIXE and scanning electron microscopy (SEM) were used in the characterization of the Harmattan dust particulates collected at Kano and Ife. Most of the elements were found to be at higher concentrations as compared to those found in Recife (Brazil) and Toronto (Canada). The value of total suspended particulate was above the relevant national air quality standards. PIXE in conjunction with Rutherford backscattering spectrometry and instrumental neutron activation analysis was employed in the

  15. Photoconversion of gasified organic materials into biologically-degradable plastics

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, Paul F. (Golden, CO); Maness, Pin-Ching (Golden, CO)

    1993-01-01

    A process is described for converting organic materials (such as biomass wastes) into a bioplastic suitable for use as a biodegradable plastic. In a preferred embodiment the process involves thermally gasifying the organic material into primarily carbon monoxide and hydrogen, followed by photosynthetic bacterial assimilation of the gases into cell material. The process is ideally suited for waste recycling and for production of useful biodegradable plastic polymer.

  16. Photoconversion of gasified organic materials into biologically-degradable plastics

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, P.F.; Pinching Maness.

    1993-10-05

    A process is described for converting organic materials (such as biomass wastes) into a bioplastic suitable for use as a biodegradable plastic. In a preferred embodiment the process involves thermally gasifying the organic material into primarily carbon monoxide and hydrogen, followed by photosynthetic bacterial assimilation of the gases into cell material. The process is ideally suited for waste recycling and for production of useful biodegradable plastic polymer. 3 figures.

  17. Nuclear measurements and reference materials annual progress report, january - december 1988

    International Nuclear Information System (INIS)

    The 1988 progress report of the Central Bureau for Nuclear Measurements (CBNM) is presented. The major changes in the role and orientation of the Joint Research Center, of which CBNM is an institute, are included. The main tasks of CBNM, which involve the program on Nuclear Measurements and Reference Materials, are given. Technical activities concerning the GELINA electron beam and Van de Graaff accelerators are reported. The study of transition radiation at linear electron accelerators, and the development of isotope dilution mass spectrometry, for trace analysis and isotope abundance measurements in iron and gallium, are summarized. The scientific and technical support to the commission, work for third parties, and contribution to conferences are presented

  18. Certified reference, intercomparison, performance evaluation and emergency preparedness exercise materials for radionuclides in food

    International Nuclear Information System (INIS)

    The threat to global security from terrorist attack does not solely arise from illicit use of firearms, explosives or weapons of mass destruction. Terrorist threats will inevitably become more subtle as information and expertise is acquired by terrorist groups, and one vulnerable area is food and the food supply chain. Many laboratories, especially in countries with nuclear programmes, are involved in the routine monitoring of foodstuffs, and will be required to respond with increased food monitoring necessary for ensuring food safety and protecting public health after real (or perceived) contamination of food by either accidental or illicit means. This paper examines the needs for reference and performance testing materials that were identified at an international workshop to discuss this matter held at NIST in 2008, and further refined at a follow-up workshop in 2009. (author)

  19. The IAEA programme and perspectives for environmental radionuclide monitoring and preparation of reference materials

    International Nuclear Information System (INIS)

    For more than thirty years, the laboratories of the International Atomic Energy Agency have been involved in the monitoring of environmental radioactivity and in the world-wide provision of reference materials for radionuclides in environmental matrices. The occurrence of hot particles in selected sites and their morphological, structural, chemical and radiochemical characteristics have to be better investigated in order to identify possible correlations with the contaminating event and to assess the associated radiological risks. Research on radionuclides in the environment will also be extended to the measurement and compilation of data on the contaminants introduced by non-nuclear industrial activities and agrochemical treatments. In response to the world-wide trend towards increased reliability, comparability and traceability of chemical and radiochemical measurements, The IAEA will revise, develop and document a set of reference analytical procedures for naturally occurring radionuclides, which will supplement the current revision of procedures for anthropogenic radionuclides. The IAEA will enhance its support provided to the laboratories in the Member States for the implementation of a quality system and to achieve traceability of their radiometric measurements. Furthermore the IAEA will continue to provide training and maintain comparability and reliability of environmental radiochemical measurements by organizing proficiency tests and interlaboratory comparisons. These tests and exercises will also be used by the IAEA to monitor and evaluate the capability and preparedness of its ALMERA (Analytical Laboratories for Measuring Environmental Radioactivity) Network

  20. A mussel (Mytilus edulis) tissue certified reference material for the marine biotoxins azaspiracids.

    Science.gov (United States)

    McCarron, Pearse; Giddings, Sabrina D; Reeves, Kelley L; Hess, Philipp; Quilliam, Michael A

    2015-04-01

    Azaspiracids (AZAs) are lipophilic biotoxins produced by marine algae that can contaminate shellfish and cause human illness. The European Union (EU) regulates the level of AZAs in shellfish destined for the commercial market, with liquid chromatography-mass spectrometry (LC-MS) being used as the official reference method for regulatory analysis. Certified reference materials (CRMs) are essential tools for the development, validation, and quality control of LC-MS methods. This paper describes the work that went into the planning, preparation, characterization, and certification of CRM-AZA-Mus, a tissue matrix CRM, which was prepared as a wet homogenate from mussels (Mytilus edulis) naturally contaminated with AZAs. The homogeneity and stability of CRM-AZA-Mus were evaluated, and the CRM was found to be fit for purpose. Extraction and LC-MS/MS methods were developed to accurately certify the concentrations of AZA1 (1.16 mg/kg), AZA2 (0.27 mg/kg), and AZA3 (0.21 mg/kg) in the CRM. Quantitation methods based on standard addition and matrix-matched calibration were used to compensate for the matrix effects in LC-MS/MS. Other toxins present in this CRM at lower levels were also measured with information values reported for okadaic acid, dinophysistoxin-2, yessotoxin, and several spirolides.

  1. Using environmental reference materials for quality assurance in spanish radiochemical laboratories

    International Nuclear Information System (INIS)

    In order to achieve international acceptance of results, laboratories must be in a position to demonstrate that their results are reliable and traceable to SI units of measurement. Laboratories can provide objective evidence of their performance through participation in external quality assessment schemes sometimes referred to as proficiency tests (PT). To achieve this objective for environmental radioactivity laboratories in Spain, CSN, in collaboration with CIEMAT, has organised periodical intercomparison exercises to provide these laboratories with the means to assess the quality of their results. In order to implement the ISO/IUPAC/AOAC Harmonised Protocol for the Proficiency Testing of Analytical Laboratories, CIEMAT has been collaborating with the IAEA-AQCS during the last two exercises and has used IAEA reference materials as test samples. The first PT was organised using the IAEA-SED-1 which is a lake sediment containing K40, Ra226, Ac228, Cs137, Sr90, and Pu-(239+240), while the second PT used IAEA-Soil- 6 for the same set of radionuclides. This paper presents the results reported for the second test as well as a comparison of the participants' performance in both tests. The application of this Harmonised Protocol has provided an objective assessment of the performance of the laboratories, enabling them to evaluate and make appropriate modifications to their procedures

  2. A mussel (Mytilus edulis) tissue certified reference material for the marine biotoxins azaspiracids.

    Science.gov (United States)

    McCarron, Pearse; Giddings, Sabrina D; Reeves, Kelley L; Hess, Philipp; Quilliam, Michael A

    2015-04-01

    Azaspiracids (AZAs) are lipophilic biotoxins produced by marine algae that can contaminate shellfish and cause human illness. The European Union (EU) regulates the level of AZAs in shellfish destined for the commercial market, with liquid chromatography-mass spectrometry (LC-MS) being used as the official reference method for regulatory analysis. Certified reference materials (CRMs) are essential tools for the development, validation, and quality control of LC-MS methods. This paper describes the work that went into the planning, preparation, characterization, and certification of CRM-AZA-Mus, a tissue matrix CRM, which was prepared as a wet homogenate from mussels (Mytilus edulis) naturally contaminated with AZAs. The homogeneity and stability of CRM-AZA-Mus were evaluated, and the CRM was found to be fit for purpose. Extraction and LC-MS/MS methods were developed to accurately certify the concentrations of AZA1 (1.16 mg/kg), AZA2 (0.27 mg/kg), and AZA3 (0.21 mg/kg) in the CRM. Quantitation methods based on standard addition and matrix-matched calibration were used to compensate for the matrix effects in LC-MS/MS. Other toxins present in this CRM at lower levels were also measured with information values reported for okadaic acid, dinophysistoxin-2, yessotoxin, and several spirolides. PMID:25335820

  3. 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

  4. 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.

  5. Feasibility study on production of a matrix reference material for cyanobacterial toxins.

    Science.gov (United States)

    Hollingdale, Christie; Thomas, Krista; Lewis, Nancy; Békri, Khalida; McCarron, Pearse; Quilliam, Michael A

    2015-07-01

    The worldwide increase in cyanobacterial contamination of freshwater lakes and rivers is of great concern as many cyanobacteria produce potent hepatotoxins and neurotoxins (cyanotoxins). Such toxins pose a threat to aquatic ecosystems, livestock, and drinking water supplies. In addition, dietary supplements prepared from cyanobacteria can pose a risk to consumers if they contain toxins. Analytical monitoring for toxins in the environment and in consumer products is essential for the protection of public health. Reference materials (RMs) are an essential tool for the development and validation of analytical methods and are necessary for ongoing quality control of monitoring operations. Since the availability of appropriate RMs for cyanotoxins has been very limited, the present study was undertaken to examine the feasibility of producing a cyanobacterial matrix RM containing various cyanotoxins. The first step was large-scale culturing of various cyanobacterial cultures that produce anatoxins, microcystins, and cylindrospermopsins. After harvesting, the biomass was lyophilized, blended, homogenized, milled, and bottled. The moisture content and physical characteristics were assessed in order to evaluate the effectiveness of the production process. Toxin levels were measured by liquid chromatography with tandem mass spectrometry and ultraviolet detection. The reference material was found to be homogeneous for toxin content. Stability studies showed no significant degradation of target toxins over a period of 310 days at temperatures up to +40 °C except for the anatoxin-a, which showed some degradation at +40 °C. These results show that a fit-for-purpose matrix RM for cyanotoxins can be prepared using the processes and techniques applied in this work. PMID:25929442

  6. Estimation of uncertainty of a reference material for proficiency testing for the determination of total mercury in fish in nature

    International Nuclear Information System (INIS)

    We provide an uncertainty estimates for homogeneity and stability studies of reference material used in proficiency test for determination of total mercury in fish fresh muscle tissue. Stability was estimated by linear regression and homogeneity by ANOVA. The results indicate that the reference material is both homogeneous and chemically stable over the short term. Total mercury concentration of the muscle tissue, with expanded uncertainty, was 0.294 ± 0.089 μg g−1

  7. Toward the Development of Certified Reference Materials for Effective Biodiesel Testing - Part 1: Processing, Homogeneity, and Stability

    OpenAIRE

    ULBERTH-BUCHGRABER MANUELA; POTALIVO MONICA; EMTEBORG Per; HELD Andrea

    2011-01-01

    To address the current lack of certified reference materials (CRMs) for biodiesel analysis, the Institute for Reference Materials and Measurements (IRMM), Joint Research Centre (JRC), European Commission (EC), launched a comprehensive feasibility study on the production of biodiesel CRMs for relevant specification parameters as provided in EN 14214,1 the basis for defining product specifications and measurement methods for biodiesel in the European Union (EU). Laboratories need to be able to ...

  8. Certification of the equivalent spherical diameters of silica nanoparticles in aqueous solution - Certified Reference Material ERM®-FD304

    OpenAIRE

    FRANKS Katrin; BRAUN ADELINA; CHAROUD-GOT Jean; COUTEAU Olivier; KESTENS Vikram; LAMBERTY MARIE ANDREE; Linsinger, Thomas; Roebben, Gert

    2011-01-01

    This report describes the certification of several equivalent spherical diameters of silica nanoparticles in aqueous solution, Certified Reference Material (CRM) ERM®-FD304. The CRM has been certified by the European Commission, Joint Research Centre, Institute for Reference Materials and Measurements (IRMM), Geel, BE. ERM-FD304 consists of silica nanoparticles suspended in aqueous solution. The intended use of this CRM is t o check the performance of instruments and methods that determine...

  9. Polish reference material: soya bean flour (INCT-SBF-4) for inorganic trace analysis - preparation and certification

    International Nuclear Information System (INIS)

    Preparation, examination and certification of the new matrix reference material of biological origin: Soya Bean Flour (INCT-SBF-4) is described. The material was prepared from soya bean grown in India, not genetically modified. After milling, the material was sieved through the 150 mm nylon sieves and stored in a polyethylene (PE) bag. Approximately 50 kg of sieved soya bean flour was collected. Examination by optical microscopy revealed that Martin's diameter of over 90% of particles was below 50 mm. The whole lot of soya bean flour was then homogenized by mixing for 20 hours in a 110 dm3 PE drum rotated in three directions. Preliminary homogeneity testing by X-ray fluorescence (XRF) method and final checking of homogeneity by neutron activation analysis (NAA) after distribution of the material into containers revealed, that it is sufficiently homogeneous at least for a sample size ≥ 100 mg. In order to assure the long-term stability, all containers with INCT-SBF-4 were sterilized by electron beam radiation. Long-term stability was checked by analyzing concentrations of selected elements in the material stored in the air-conditioned room at 20 oC. Short-term stability was examined by the determination of concentrations of the selected elements in the bottle stored in the CO2 incubator at 37 oC. The material was certified on the basis of a worldwide interlaboratory comparison, in which 92 laboratories from 19 countries participated providing 1107 laboratory averages (4873 individual determinations) for 58 elements. A method of data evaluation leading to assignment of certified values was the same as that used previously in the Laboratory of the Department of Analytical Chemistry, Institute of Nuclear Chemistry and Technology. The results for a few elements were obtained by definitive methods developed in the Laboratory and used to support the certification process. Analytical uncertainties and stability uncertainties were quantified to arrive at combined

  10. Biology of the black-backed jackal Canis mesomelas with reference to rabies.

    Science.gov (United States)

    McKenzie, A A

    1993-12-01

    The black-backed jackal is represented in rabies records from southern Africa and is suspected of playing an important role in the disease in this region. The basic biology of the species suggests that it does have certain characteristics that could make it an ideal rabies vector. However, the engimatically low incidence of rabies in undisturbed jackal populations suggests that more subtle processes may be involved. It is suggested that jackal society is arranged in the form of cryptic packs and that disruption of the hierachy through persecution may increase agonistic encounters and thence the incidence of rabies. Suggestions are made for the incorporation of the jackal in rabies control programmes without resorting to extermination. PMID:7777322

  11. Integrated multilaboratory systems biology reveals differences in protein metabolism between two reference yeast strains

    DEFF Research Database (Denmark)

    Canelas, Andre B.; Harrison, Nicola; Fazio, Alessandro;

    2010-01-01

    The field of systems biology is often held back by difficulties in obtaining comprehensive, high-quality, quantitative data sets. In this paper, we undertook an interlaboratory effort to generate such a data set for a very large number of cellular components in the yeast Saccharomyces cerevisiae......, a widely used model organism that is also used in the production of fuels, chemicals, food ingredients and pharmaceuticals. With the current focus on biofuels and sustainability, there is much interest in harnessing this species as a general cell factory. In this study, we characterized two yeast strains...... analysis of the high-throughput data, we hypothesize that differences in phenotype are due to differences in protein metabolism....

  12. Preparation and biological evaluations of PLA/chitosan composite materials

    Institute of Scientific and Technical Information of China (English)

    ZHOU Chang-ren; LI Lihua; DING Shan

    2001-01-01

    @@ INTRODUCTION Polylactic acid (PLA) is a biodegradable material that is hontoxic and biocompatible. However, as scaffold materials, PLA has several obvious weaknesses:biodegrading too fast, acidic degradation product, and hydrophobic. When PLA isplanted in the body, the degradation takes place synchronously.

  13. Environmental effects on recruitment and implications for biological reference points of Eastern Baltic cod (Gadus morhua)

    DEFF Research Database (Denmark)

    Köster, Fritz; Vinther, Morten; MacKenzie, Brian;

    2009-01-01

    stock productivity. Long-term projections suggest that under adverse environmental conditions for reproduction, harvesting at fishing mortality determined as precautionary may not lead to a recovery of the stock to a biomass level considered precautionary. Thus, a revision of either the limit fishing......The decline of the Eastern Baltic cod (Gadus morhua) stock from highest to lowest stock levels on record throughout the 1980s and early 1990s was caused by a combination of recruitment failure and increasing fishing pressure at declining stock sizes. The processes driving the reproductive success...... of limit reference points, but according to long-term simulations also for target fishing mortalities, being central parts of harvest control rules in several management plans....

  14. 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

  15. 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.

  16. Collaborative study for the calibration of replacement batches for the heparin low-molecular-mass for assay biological reference preparation.

    Science.gov (United States)

    Terao, E; Daas, A

    2016-01-01

    The European Pharmacopoeia (Ph. Eur.) prescribes the control of the activity of low molecular mass heparins by assays for anti-Xa and anti-IIa activities (monograph 0828), using a reference standard calibrated in International Units (IU). An international collaborative study coded BSP133 was launched in the framework of the Biological Standardisation Programme (BSP) run under the aegis of the Council of Europe and the European Commission to calibrate replacement batches for the dwindling stocks of the Heparin low-molecular-mass for assay Biological Reference Preparation (BRP) batch 8. Thirteen official medicines control and manufacturers laboratories from European and non-European countries took part in this study to calibrate two freeze-dried candidate batches against the 3rd International Standard (IS) for heparin, low molecular weight (11/176; 3rd IS). The Heparin low-molecular-mass for assay BRP (batch 8) was also included in the test panel to check the continuity between subsequent BRP batches. Taking into account the stability data, the results of this collaborative study and on the basis of the central statistical analysis performed at the European Directorate for the Quality of Medicines & HealthCare (EDQM), the 2 candidate batches were officially adopted by the Commission of the European Pharmacopoeia as Heparin low-molecular-mass for assay BRP batches 9 and 10 with assigned anti-Xa activities of 102 and 100 IU/vial and anti-IIa activities of 34 and 33 IU/vial respectively. PMID:27507705

  17. Proposals for the use of reference materials and for the development of in-house quality control materials for food analysis

    International Nuclear Information System (INIS)

    A summary is presented of factors to be considered in the development of food-based in-house quality control materials to augment available Reference Materials and for frequent, concerted data quality control. Some guidelines are offered regarding approaches to the many considerations required for such an endeavour. Preliminary draft recommendations containing a sequence of steps has been compiled as a starting proposal for a food quality control material development scheme, for a range of natural matrices and measurands. In addition, information on the selection and utilization of Certified Reference Materials and procedures for performance interpretation and corrective action is provided. (author)

  18. Propulsion of swimming microrobots inspired by metachronal waves in ciliates: from biology to material specifications

    International Nuclear Information System (INIS)

    The quest for swimming microrobots originates from possible applications in medicine, especially involving navigation in bodily fluids. Swimming microorganisms have become a source of inspiration because their propulsion mechanisms are effective in the low-Reynolds number regime. In this study, we address a propulsion mechanism inspired by metachronal waves, i.e. the spontaneous coordination of cilia leading to the fast swimming of ciliates. We analyse the biological mechanism (referring to its particular embodiment in Paramecium caudatum), and we investigate the contribution of its main features to the swimming performance, through a three-dimensional finite-elements model, in order to develop a simplified, yet effective artificial design. We propose a bioinspired propulsion mechanism for a swimming microrobot based on a continuous cylindrical electroactive surface exhibiting perpendicular wave deformations travelling longitudinally along its main axis. The simplified propulsion mechanism is conceived specifically for microrobots that embed a micro-actuation system capable of executing the bioinspired propulsion (self-propelled microrobots). Among the available electroactive polymers, we select polypyrrole as the possible actuation material and we assess it for this particular embodiment. The results are used to appoint target performance specifications for the development of improved or new electroactive materials to attain metachronal-waves-like propulsion. (paper)

  19. Determination of halogens, with special reference to iodine, in geological and biological samples using pyrohydrolysis for preparation and inductively coupled plasma mass spectrometry and ion chromatography for measurement.

    Science.gov (United States)

    Schnetger, B; Muramatsu, Y

    1996-11-01

    A method for determining iodine, bromine, chlorine and fluorine in geological and biological materials is described. In a quartz tube, solid material was heated to 1100 degrees C under a wet oxygen flow (pyrohydrolysis). By this process the halogens (I, Br, Cl, F) were separated from the matrix and then collected in a receiver solution. The chemical yield of iodine was determined by a radioactive tracer. ICP-MS and ion chromatographic measurements were used for the determination of the halogens. The method was optimized by investigating different experimental conditions. All four halogens can be trapped in the receiver solution from one combustion procedure. Precision and accuracy were evaluated by the analysis of environmental standard reference materials (rock, soil, milk, leaves, marine tissue). The concentrations in the materials analysed were in the ranges 0.006-50 mg kg-1 for I, 0.06-1300 mg kg-1 for Br, 50-1100 mg kg-1 for F and 400-11000 mg kg-1 for Cl. The lower values represent the practical detection limit of this method. The results obtained by the proposed method and the certified values are in good agreement. PMID:8952450

  20. 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

  1. New improved method for evaluation of growth by food related fungi on biologically derived materials

    DEFF Research Database (Denmark)

    Bergenholtz, Karina P.; Nielsen, Per Væggemose

    2002-01-01

    Biologically derived materials, obtained as commercial and raw materials (Polylactate (PLA), Polyhydroxybutyrate (PHB), potato, wheat and corn starch) were tested for their ability to support fungal growth using a modified ASTM G21-96 (American Society for Testing and Materials) standard as well ...

  2. Quantification of ultraviolet photon emission from interaction of charged particles in materials of interest in radiation biology research

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Syed Bilal, E-mail: ahmadsb@mcmaster.ca [Department of Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, ON (Canada); Department of Physics and Applied Mathematics, Pakistan Institute of Engineering and Applied Sciences, Islamabad (Pakistan); McNeill, Fiona E., E-mail: fmcneill@mcmaster.ca [Department of Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, ON (Canada); Prestwich, William V., E-mail: prestwic@mcmaster.ca [Department of Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, ON (Canada); Byun, Soo Hyun, E-mail: soohyun@mcmaster.ca [Department of Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, ON (Canada); Seymour, Colin, E-mail: seymouc@mcmaster.ca [Department of Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, ON (Canada); Mothersill, Carmel E., E-mail: mothers@mcmaster.ca [Department of Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, ON (Canada)

    2014-01-15

    In radiation biology experiments often cells are irradiated using charged particles with the intention that only a specified number of cells are hit by the primary ion track. However, in doing so several other materials such as the cell container and the growth media etc. are also irradiated, and UV radiation emitted from these materials can potentially interact with the cells. We have hypothesized that some “bystander effects” that are thought to be chemically mediated, may be, in fact, a physical effect, where UV is interacting with non-targeted cells. Based upon our hypothesis we quantified the emission of UV from Polypropylene, Mylar, Teflon, and Cellophane which are all commonly used materials in radiation biology experiments. Additionally we measured the NIST standard materials of Oyster tissue and Citrus leaves as these powdered materials are derived from living cells. Protons accelerated up to an energy of 2.2 MeV, in a 3 MV Van de Graff accelerator, were used for irradiation. Beam current was kept to 10 nA, which corresponds to a proton fluence rate of 2.7 × 10{sup 10} protons mm{sup −2} s{sup −1}. All the materials were found to emit light at UV frequencies and intensities that were significant enough to conduct a further investigation for their biological consequences. Mylar and polypropylene are commonly used in radiation induced bystander effect studies and are considered to be non-fluorescent. However our study showed that this is not the case. Significant luminescence observed from the irradiated NIST standard reference materials for Oyster tissue and Citrus leaves verified that the luminescence emission is not restricted only to the polymeric materials that are used to contain cells. It can also occur from ion interactions within the cells as well.

  3. NIST bullet signature measurement system for RM (Reference Material) 8240 standard bullets.

    Science.gov (United States)

    Ma, Li; Song, John; Whitenton, Eric; Zheng, Alan; Vorburger, Theodore; Zhou, Jack

    2004-07-01

    A bullet signature measurement system based on a stylus instrument was developed at the National Institute of Standards and Technology (NIST) for the signature measurements of NIST RM (Reference Material) 8240 standard bullets. The standard bullets are developed as a reference standard for bullet signature measurements and are aimed to support the recently established National Integrated Ballistics Information Network (NIBIN) by the Bureau of Alcohol, Tobacco and Firearms (ATF) and the Federal Bureau of Investigation (FBI). The RM bullets are designed as both a virtual and a physical bullet signature standard. The virtual standard is a set of six digitized bullet signatures originally profiled from six master bullets fired at ATF and FBI using six different guns. By using the virtual signature standard to control the tool path on a numerically controlled diamond turning machine at NIST, 40 RM bullets were produced. In this paper, a comparison parameter and an algorithm using auto-and cross-correlation functions are described for qualifying the bullet signature differences between the RM bullets and the virtual bullet signature standard. When two compared signatures are exactly the same (point by point), their cross-correlation function (CCF) value will be equal to 100%. The measurement system setup, measurement program, and initial measurement results are discussed. Initial measurement results for the 40 standard bullets, each measured at six land impressions, show that the CCF values for the 240 signature measurements are higher than 95%, with most of them even higher than 99%. These results demonstrate the high reproducibility for both the manufacturing process and the measurement system for the NIST RM 8240 standard bullets. PMID:15317178

  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. Report of the 2nd research co-ordination meeting on reference materials for microanalytical nuclear techniques

    International Nuclear Information System (INIS)

    Many microanalytical procedure require specific natural-matrix reference materials containing very low levels of trace elements and having a high degree of homogeneity. This proposed CRP will specifically address the question of quality control materials for these techniques. The participants of the meeting discussed the requirements for certified reference materials to by used in microanalysis with particular emphasis on the homogeneity issues. This publication contains summary of the discussions along with conclusions and recommendations made by the participants. The publication also contains ten individual presentations delivered by the participants. Each of the individual papers has been provided with an abstract and indexed separately

  6. Biomolecular coronas provide the biological identity of nanosized materials

    NARCIS (Netherlands)

    Monopoli, Marco P; Åberg, Christoffer; Salvati, Anna; Dawson, Kenneth A

    2012-01-01

    The search for understanding the interactions of nanosized materials with living organisms is leading to the rapid development of key applications, including improved drug delivery by targeting nanoparticles, and resolution of the potential threat of nanotechnological devices to organisms and the en

  7. Fragment Produced by Nuclear Reaction of Heavy Ions Interacted with Tissue-equivalent Biological Material

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In heavy ion therapy and radiation biological effects the nuclear fragments from the heavy ion collisions may cause a significant alteration of the radiation field. Nuclear collision between beam particles and tissue nuclei along the penetration path of high-energy ions in tissue or biological-equivalent material causes a loss

  8. Provisional Assessment of Candidate High-Temperature Thermal Conductivity Reference Materials in the EMRP “Thermo” Project

    OpenAIRE

    Wu, J.; Morrell, R; T. Fry; Gnaniah, S.; Gohil, D.; Dawson, A.; Hameury, J.; Koenen, Alain; Hammerschmidt, U.; Turzó-András, E.; Strnad, R.; Blahut, A.

    2015-01-01

    This article describes the provisional assessment of a short list of four candidate high-temperature thermal conductivity reference materials in a European research project, “Thermo.” These four candidate materials are low-density calcium silicate, amorphous silica, high-density calcium silicate, and exfoliated vermiculite. Based on initial tests on material composition and microstructure changes, dimensional stability, mechanical stability, chemical stability and uniformity, the best two can...

  9. 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.

  10. Development of a candidate certified reference material of cypermethrin in green tea

    International Nuclear Information System (INIS)

    Highlights: ► A cypermethrin CRM in green tea was developed. ► Using two isotope dilution mass spectrometry techniques for characterization. ► Certified value of 148 μg kg−1 with expanded uncertainty of ±9.2%. ► Support quality assurance of pesticide residue analysis in tea to testing. - Abstract: This paper presents the preparation of a candidate certified reference material (CRM) of cypermethrin in green tea, GLHK-11-01a according to the requirements of ISO Guide 34 and 35. Certification of the material was performed using a newly developed isotope dilution mass spectrometry (IDMS) approach, with gas chromatography high resolution mass spectrometry (GC–HRMS) and gas chromatography–tandem mass spectrometry (GC–MS/MS). Statistical analysis (one-way ANOVA) showed excellent agreement of the analytical data sets generated from the two mass spectrometric detections. The characterization methods have also been satisfactorily applied in an Asia-Pacific Metrology Program (APMP) interlaboratory comparison study. Both the GC–HRIDMS and GC–IDMS/MS methods proved to be sufficiently reliable and accurate for certification purpose. The certified value of cypermethrin in dry mass fraction was 148 μg kg−1 and the associated expanded uncertainty was 14 μg kg−1. The uncertainty budget was evaluated from sample in homogeneity, long-term and short-term stability and variability in the characterization procedure. GLHK-11-01a is primarily developed to support the local and wider testing community on need basis in quality assurance work and in seeking accreditation.

  11. Multiscale modeling of emergent materials: biological and soft matter

    DEFF Research Database (Denmark)

    Murtola, Teemu; Bunker, Alex; Vattulainen, Ilpo;

    2009-01-01

    In this review, we focus on four current related issues in multiscale modeling of soft and biological matter. First, we discuss how to use structural information from detailed models (or experiments) to construct coarse-grained ones in a hierarchical and systematic way. This is discussed...... in the context of the so-called Henderson theorem and the inverse Monte Carlo method of Lyubartsev and Laaksonen. In the second part, we take a different look at coarse graining by analyzing conformations of molecules. This is done by the application of self-organizing maps, i.e., a neural network type approach....... Such an approach can be used to guide the selection of the relevant degrees of freedom. Then, we discuss technical issues related to the popular dissipative particle dynamics (DPD) method. Importantly, the potentials derived using the inverse Monte Carlo method can be used together with the DPD thermostat...

  12. Analysis of biological materials using a nuclear microprobe

    Science.gov (United States)

    Mulware, Stephen Juma

    The use of nuclear microprobe techniques including: Particle induced x-ray emission (PIXE) and Rutherford backscattering spectrometry (RBS) for elemental analysis and quantitative elemental imaging of biological samples is especially useful in biological and biomedical research because of its high sensitivity for physiologically important trace elements or toxic heavy metals. The nuclear microprobe of the Ion Beam Modification and Analysis Laboratory (IBMAL) has been used to study the enhancement in metal uptake of two different plants. The roots of corn (Zea mays) have been analyzed to study the enhancement of iron uptake by adding Fe (II) or Fe(III) of different concentrations to the germinating medium of the seeds. The Fe uptake enhancement effect produced by lacing the germinating medium with carbon nanotubes has also been investigated. The aim of this investigation is to ensure not only high crop yield but also Fe-rich food products especially from calcareous soil which covers 30% of world's agricultural land. The result will help reduce iron deficiency anemia, which has been identified as the leading nutritional disorder especially in developing countries by the World Health Organization. For the second plant, Mexican marigold (Tagetes erecta ), the effect of an arbuscular mycorrhizal fungi (Glomus intraradices ) for the improvement of lead phytoremediation of lead contaminated soil has been investigated. Phytoremediation provides an environmentally safe technique of removing toxic heavy metals (like lead), which can find their way into human food, from lands contaminated by human activities like mining or by natural disasters like earthquakes. The roots of Mexican marigold have been analyzed to study the role of arbuscular mycorrhizal fungi in enhancement of lead uptake from the contaminated rhizosphere.

  13. An evaluation of thermal and epithermal neutron activation analysis compton suppression methods for biological reference materials.

    Science.gov (United States)

    Landsberger, S; Wu, D

    1999-01-01

    For neutron activation analysis (NAA), the usual matrix problems of sodium, chlorine, and bromine are well known to give rise to high backgrounds that inhibit the determination of several trace elements for short-lived or medium-lived NAA. For long counting times in long-lived NAA, very low backgrounds are required to achieve good sensitivities. We have investigated the use of thermal and epithermal NAA in conjunction with Compton suppression to determine several elements such as arsenic, antimony, cadmium, and mercury, at the level of a few nanograms. The values of these techniques are discussed in contrast to the standard radiochemical methods. PMID:10676521

  14. Physical properties of oil-SPM aggregates : experiments with NIST standard reference material 1941b

    Energy Technology Data Exchange (ETDEWEB)

    Khelifa, A.; Brown, C.E. [Environment Canada, Ottawa, ON (Canada). Emergencies Science and Technology Division, Science and Technology Branch, Environmental Science and Technology Centre; Chun, M.; Eubank, J.L.E. [Waterloo Univ., ON (Canada). Nanotechnology Engineering

    2008-07-01

    Oil spilled in water disperses by a natural process in which suspended particulate matter (SPM) combines with oil droplets to form Oil-SPM aggregates (OSA). This paper presented a newly developed experimental procedure to measure the physical properties of OSAs, including size, settling velocity and effective density. A laboratory setup was created to examine the formation of OSAs in which the sediment Standard Reference Material 1941b was mixed with Arabian Medium and South Louisiana crude oils, and Corexit 9500 chemical dispersants at various concentrations. The study revealed that the hypothesis stating that OSAs are neutrally buoyant and do not settle to the seafloor is not valid. The OSAs appeared to behave as sediment flocs commonly observed in coastal waters. It was concluded that from an oil spill response perspective, the use of chemical dispersant in coaster waters rich in SPM could be problematic since it may enhance oil sedimentation and contaminate the seafloor. However, further research is needed to evaluate the effects of other key factors controlling the fate of OSAs that were not investigated in this study. These include the effect of mixing energy and the settling process of natural flocs. 29 refs., 1 tab., 10 figs.

  15. Uranium Isotopic Ratio Measurements of U3O8 Reference Materials by Atom Probe Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Fahey, Albert J.; Perea, Daniel E.; Bartrand, Jonah AG; Arey, Bruce W.; Thevuthasan, Suntharampillai

    2016-01-01

    We report results of measurements of isotopic ratios obtained with atom probe tomography on U3O8 reference materials certified for their isotopic abundances of uranium. The results show good agreement with the certified values. High backgrounds due to tails from adjacent peaks complicate the measurement of the integrated peak areas as well as the fact that only oxides of uranium appear in the spectrum, the most intense of which is doubly charged. In addition, lack of knowledge of other instrumental parameters, such as the dead time, may bias the results. Isotopic ratio measurements can be performed at the nanometer-scale with the expectation of sensible results. The abundance sensitivity and mass resolving power of the mass spectrometer are not sufficient to compete with magnetic-sector instruments but are not far from measurements made by ToF-SIMS of other isotopic systems. The agreement of the major isotope ratios is more than sufficient to distinguish most anthropogenic compositions from natural.

  16. 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.

  17. 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.

  18. Determination of multielements in a typical Japanese diet certified reference material by instrumental neutron activation analysis.

    Science.gov (United States)

    Suzuki, Shogo; Okada, Yukiko; Hirai, Shoji

    2003-08-01

    Multielements in a typical Japanese diet certified reference material prepared at the National Institute for Environmental Studies (NIES) of Japan, in collaboration with the National Institute of Radiological Sciences (NIRS) of Japan were determined by instrumental neutron activation analysis (INAA). Five samples (ca. 510-1000 mg) and comparative standards were irradiated for a short time (10 s) at a thermal neutron flux of 1.5 x 10(12) n cm(-2) s(-1) (pneumatic transfer) and for a long time (6 h) at a thermal neutron flux of 3.7 x 10(12) n cm(-2) s(-1) (central thimble) in the Rikkyo University Research Reactor (TRIGA Mark-II, 100 kW). The irradiated samples were measured by conventional gama-ray spectrometry using a coaxial Ge detector, and by anti-coincidence and coincidence gamma-ray spectrometry with a coaxial Ge detector and a well-type NaI(Tl) detector. The concentrations of 38 elements were determined by these methods. PMID:12945682

  19. Results of 14C analysis on low-level reference materials

    International Nuclear Information System (INIS)

    An invitation from the University of Glasgow to participate in an international intercomparison of 14C 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 14C 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 14C between 50 and 500 Bq/kg C. Samples from the University of Glasgow, Scotland, were also analyzed and reported. The results of counting various CO2 blank materials (dry ice from a CO2-siphon and limestone) showed that the source of CO2 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 (LQ) for samples during the ETB's routine operations has been documented to be 44 Bq/kg C. (author)

  20. 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. PMID:27524810

  1. Multielement analysis of human hair reference material by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    A Human Hair (NIES No. 5) as an environmental reference material prepared by the National Institute for Environmental Studies of Japan (NIES) was analyzed by an instrumental neutron activation method. The human hair samples (ca. 200∼500 mg) were irradiated for 2 min or 5 h at Musashi Institute of Technology Research Reactor. The activated samples were measured by four gamma-ray spectrometories, namely a spectrometry using a coaxial Ge detector, anticoincidence and coincidence counting spectrometries using a coaxial Ge detector, and a well-type NaI (Tl) detector, and a low energy photon spectrometry (LEPS) using a planer Ge detector, to determine as many trace elements as possible with high sensitivity. Concentrations of 43 elements (Na, Mg, Al, Si, S, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Ag, Cd, Sn, Sb, I, Cs, Ba, La, Ce, Nd, Sm, Eu, Tb, Yb, Hf, Ta, Au, Hg, Th, U) were determined by these measurements. The analyzed values of many elements except Sr were in good agreement with NIES certified values determined by nine different analytical methods. (author)

  2. The preparation of uranium-doped glass reference materials for environmental measurements

    Science.gov (United States)

    Raptis, K.; Ingelbrecht, C.; Wellum, R.; Alonso, A.; De Bolle, W.; Perrin, R.

    2002-03-01

    Seven different uranium glass powders containing 5 mass% uranium with 235U abundances from natural to highly enriched have been prepared for the IRMM support programme to the International Atomic Energy Agency (IAEA) and for the IRMM external NUSIMEP quality control programme (Nuclear Signatures Interlaboratory Measurement Evaluation Programme). The particles will be primarily used, blended with (inactive) matrix glass powder in various ratios to simulate environmental samples containing "hot" particles in order to assess the performance of various separation and measurement techniques. High-purity borosilicate glass was prepared by blending of powders, melting and grinding by ball milling and jet milling to a powder of about 12 μm. A quantity of this glass was then blended with U 3O 8, melted and milled to powder. Laser diffraction measurements were made to ensure that the particle size distribution of the uranium glass matched that of the matrix glass in order to ensure homogeneous blending. The final yield was 30-40 g of each uranium glass and 1 kg of matrix glass. The glasses have been certified as reference materials for isotope abundances of uranium.

  3. Low cost materials of construction for biological processes: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1993-05-13

    The workshop was held, May 1993 in conjunction with the 15th Symposium on Biotechnology for Fuels and Chemicals. The purpose of this workshop was to present information on the biomass to ethanol process in the context of materials selection and through presentation and discussion, identify promising avenues for future research. Six technical presentations were grouped into two sessions: process assessment and technology assessment. In the process assessment session, the group felt that the pretreatment area would require the most extensive materials research due the complex chemical, physical and thermal environment. Discussion centered around the possibility of metals being leached into the process stream and their effect on the fermentation mechanics. Linings were a strong option for pretreatment assuming the economics were favorable. Fermentation was considered an important area for research also, due to the unique complex of compounds and dual phases present. Erosion in feedstock handling equipment was identified as a minor concern. In the technology assessment session, methodologies in corrosion analysis were presented in addition to an overview of current coatings/linings technology. Widely practiced testing strategies, including ASTM methods, as well as novel procedures for micro-analysis of corrosion were discussed. Various coatings and linings, including polymers and ceramics, were introduced. The prevailing recommendations for testing included keeping the testing simple until the problem warranted a more detailed approach and developing standardized testing procedures to ensure the data was reproducible and applicable. The need to evaluate currently available materials such as coatings/linings, carbon/stainless steels, or fiberglass reinforced plastic was emphasized. It was agreed that economic evaluation of each material candidate must be an integral part of any research plan.

  4. Biological Parameters and Molecular Markers of Clone CL Brener - The Reference Organism of the Trypanosoma cruzi Genome Project

    Directory of Open Access Journals (Sweden)

    Bianca Zingales

    1997-11-01

    Full Text Available Clone CL Brener is the reference organism used in the Trypanosoma cruzi Genome Project. Some biological parameters of CL Brener were determined: (a the doubling time of epimastigote forms cultured in liver infusion-tryptose (LIT medium at 28oC is 58±13 hr; (b differentiation of epimastigotes to metacyclic trypomastigotes is obtained by incubation in LIT-20% Grace´s medium; (c trypomastigotes infect mammalian cultured cells and perform the complete intracellular cycle at 33 and 37oC; (d blood forms are highly infective to mice; (e blood forms are susceptible to nifurtimox and benznidazole. The molecular typing of CL Brener has been determined: (a isoenzymatic profiles are characteristic of zymodeme ZB; (b PCR amplification of a 24Sa ribosomal RNA sequence indicates it belongs to T. cruzi lineage 1; (c schizodeme, randomly amplified polymorphic DNA (RAPD and DNA fingerprinting analyses were performed

  5. Status of study on biological and toxicological effects of nanoscale materials

    Institute of Scientific and Technical Information of China (English)

    WANG Bing; FENG Weiyue; ZHAO Yuliang; XING Gengmei; CHAI Zhifang; WANG Haifang; JIA Guang

    2005-01-01

    Because the physical and chemical properties of nanosized materials mostly differ from the existing microsized materials, their potential impacts on human health and the environment will be topics under the serious discussions in press and in a number of international scientific journals. We analyze and summarize the existing data of the experimental study on the biological activities and adverse effects of nanoscale materials/particles including single wall carbon nanotubes, multi wall carbon nanotubes, titanium oxide and iron powders. Though some biological behaviors of nanoscale materials observed cannot be understood on the basis of the current knowledge, as the existing data are mostly preliminary, it is too early to make some exclusive conclusions on biological activities (or the toxicity) of any of nanoscale materials. The experimental techniques, the current topics, and the future research directions for this new research field are also discussed.

  6. Analysis of hazardous biological material by MALDI mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    KL Wahl; KH Jarman; NB Valentine; MT Kingsley; CE Petersen; ST Cebula; AJ Saenz

    2000-03-21

    Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-MS) has become a valuable tool for analyzing microorganisms. The speed with which data can be obtained from MALDI-MS makes this a potentially important tool for biological health hazard monitoring and forensic applications. The excitement in the mass spectrometry community in this potential field of application is evident by the expanding list of research laboratories pursuing development of MALDI-MS for bacterial identification. Numerous research groups have demonstrated the ability to obtain unique MALDI-MS spectra from intact bacterial cells and bacterial cell extracts. The ability to differentiate strains of the same species has been investigated. Reproducibility of MALDI-MS spectra from bacterial species under carefully controlled experimental conditions has also been demonstrated. Wang et al. have reported on interlaboratory reproducibility of the MALDI-MS analysis of several bacterial species. However, there are still issues that need to be addressed, including the careful control of experimental parameters for reproducible spectra and selection of optimal experimental parameters such as solvent and matrix.

  7. Preparation of Biologically Active Materials by Biomimetic Process

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In order to form the apatite nuclei on a surface of the substrate,the substrate was placed on or in CaO,SiO2-based glass particles which were soaked in a simulated body fluid with ion concentrations nearly equal to those of human blood plasma,and to make the apatite nuclei grow on the substrate in situ,the substrate was soaked in another solution highly supersaturated with respect to the apatite. The induction period for the apatite nucleation varied from 0 to 4 days depending on the kind of the substrate. The thickness of the apatite layer increases linearly with increasing soaking time in the second solution.The rate of growth of the apatite layer increases with increasing degree of the supersaturation and temperature of the second solution, reaching 7um/d in a solution with ion concentrations which is as 1.5 times as those of the simulated body fluid at 60 ℃. The adhesive strength of the apatite layer to the substrate varies depending on the kind and roughness of the substrate. Polyethyleneterephthalate and polyethersulfone plates abraded with No.400 diamond paste show adhesive strengths of as high as 4 MPa. This type of composite of the bone-like apatite with metals, ceramics and organic polymers might be useful not only as highly bioactive hard tissue-repairing materials with analogous mechanical properties to those of the hard tissues, but also as highly biocompatible soft tissue-repairing materials with ductility.

  8. Sample sizing of biological materials analyzed by energy dispersion X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Paiva, Jose D.S.; Franca, Elvis J.; Magalhaes, Marcelo R.L.; Almeida, Marcio E.S.; Hazin, Clovis A., E-mail: dan-paiva@hotmail.com, E-mail: ejfranca@cnen.gov.br, E-mail: marcelo_rlm@hotmail.com, E-mail: maensoal@yahoo.com.br, E-mail: chazin@cnen.gov.b [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2013-07-01

    Analytical portions used in chemical analyses are usually less than 1g. Errors resulting from the sampling are barely evaluated, since this type of study is a time-consuming procedure, with high costs for the chemical analysis of large number of samples. The energy dispersion X-ray fluorescence - EDXRF is a non-destructive and fast analytical technique with the possibility of determining several chemical elements. Therefore, the aim of this study was to provide information on the minimum analytical portion for quantification of chemical elements in biological matrices using EDXRF. Three species were sampled in mangroves from the Pernambuco, Brazil. Tree leaves were washed with distilled water, oven-dried at 60 deg C and milled until 0.5 mm particle size. Ten test-portions of approximately 500 mg for each species were transferred to vials sealed with polypropylene film. The quality of the analytical procedure was evaluated from the reference materials IAEA V10 Hay Powder, SRM 2976 Apple Leaves. After energy calibration, all samples were analyzed under vacuum for 100 seconds for each group of chemical elements. The voltage used was 15 kV and 50 kV for chemical elements of atomic number lower than 22 and the others, respectively. For the best analytical conditions, EDXRF was capable of estimating the sample size uncertainty for further determination of chemical elements in leaves. (author)

  9. Detection of Biological Materials Using Ion Mobility Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Rodacy, P.J.; Sterling, J.P.; Butler, M.A.

    1999-03-01

    Traditionally, Ion Mobility Spectroscopy has been used to examine ions of relatively low molecular weight and high ion mobility. In recent years, however, biomolecules such as bradykinin, cytochrome c, bovine pancreatic trypsin inhibitor (BPTI), apomyoglobin, and lysozyme, have been successfully analyzed, but studies of whole bio-organisms have not been performed. In this study an attempt was made to detect and measure the mobility of two bacteriophages, {lambda}-phage and MS2 using electrospray methods to inject the viruses into the ion mobility spectrometer. Using data from Yeh, et al., which makes a comparison between the diameter of non-biologic particles and the specific particle mobility, the particle mobility for the MS2 virus was estimated to be 10{sup {minus}2} cm{sup 2}/volt-sec. From this mobility the drift time of these particles in our spectrometer was calculated to be approximately 65 msec. The particle mobility for the {lambda}-phage virus was estimated to be 10{sup {minus}3} cm{sup 2}/volt-sec. which would result in a drift time of 0.7 sec. Spectra showing the presence of a viral peak at the expected drift time were not observed. However, changes in the reactant ion peak that could be directly attributed to the presence of the viruses were observed. Virus clustering, excessive collisions, and the electrospray injection method limited the performance of this IMS. However, we believe that an instrument specifically designed to analyze such bioagents and utilizing other injection and ionization methods will succeed in directly detecting viruses and bacteria.

  10. Model of heterogeneous material dissolution in simulated biological fluid

    Science.gov (United States)

    Knyazeva, A. G.; Gutmanas, E. Y.

    2015-11-01

    In orthopedic research, increasing attention is being paid to bioresorbable/biodegradable implants as an alternative to permanent metallic bone healing devices. Biodegradable metal based implants possessing high strength and ductility potentially can be used in load bearing sites. Biodegradable Mg and Fe are ductile and Fe possess high strength, but Mg degrades too fast and Fe degrades too slow, Ag is a noble metal and should cause galvanic corrosion of the more active metallic iron - thus, corrosion of Fe can be increased. Nanostructuring should results in higher strength and can result in higher rate of dissolution/degradation from grain boundaries. In this work, a simple dissolution model of heterogeneous three phase nanocomposite material is considered - two phases being metal Fe and Ag and the third - nanopores. Analytical solution for the model is presented. Calculations demonstrate that the changes in the relative amount of each phase depend on mass exchange and diffusion coefficients. Theoretical results agree with preliminary experimental results.

  11. Manipulating lipid bilayer material properties using biologically active amphipathic molecules

    Energy Technology Data Exchange (ETDEWEB)

    Ashrafuzzaman, Md [Department of Physiology and Biophysics, Weill Medical College of University of Cornell, New York, NY 10021 (United States); Lampson, M A [Department of Physiology and Biophysics, Weill Medical College of University of Cornell, New York, NY 10021 (United States); Greathouse, D V [Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701 (United States); II, R E Koeppe [Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701 (United States); Andersen, O S [Department of Physiology and Biophysics, Weill Medical College of University of Cornell, New York, NY 10021 (United States)

    2006-07-19

    Lipid bilayers are elastic bodies with properties that can be manipulated/controlled by the adsorption of amphipathic molecules. The resulting changes in bilayer elasticity have been shown to regulate integral membrane protein function. To further understand the amphiphile-induced modulation of bilayer material properties (thickness, intrinsic monolayer curvature and elastic moduli), we examined how an enantiomeric pair of viral anti-fusion peptides (AFPs)-Z-Gly-D-Phe and Z-Gly-Phe, where Z denotes a benzyloxycarbonyl group, as well as Z-Phe-Tyr and Z-D-Phe-Phe-Gly-alters the function of enantiomeric pairs of gramicidin channels of different lengths in planar bilayers. For both short and long channels, the channel lifetimes and appearance frequencies increase as linear functions of the aqueous AFP concentration, with no apparent effect on the single-channel conductance. These changes in channel function do not depend on the chirality of the channels or the AFPs. At pH 7.0, the relative changes in channel lifetimes do not vary when the channel length is varied, indicating that these compounds exert their effects primarily by causing a positive-going change in the intrinsic monolayer curvature. At pH 4.0, the AFPs are more potent than at pH 7.0 and have greater effects on the shorter channels, indicating that these compounds now change the bilayer elastic moduli. When AFPs of different anti-fusion potencies are compared, the rank order of the anti-fusion activity and the channel-modifying activity is similar, but the relative changes in anti-fusion potency are larger than the changes in channel-modifying activity. We conclude that gramicidin channels are useful as molecular force transducers to probe the influence of small amphiphiles upon lipid bilayer material properties.

  12. DNA copy number concentration measured by digital and droplet digital quantitative PCR using certified reference materials.

    Science.gov (United States)

    Corbisier, Philippe; Pinheiro, Leonardo; Mazoua, Stéphane; Kortekaas, Anne-Marie; Chung, Pui Yan Jenny; Gerganova, Tsvetelina; Roebben, Gert; Emons, Hendrik; Emslie, Kerry

    2015-03-01

    The value assignment for properties of six certified reference materials (ERM-AD623a-f), each containing a plasmid DNA solution ranging from 1 million to 10 copies per μL, by using digital PCR (dPCR) with the BioMark™ HD System (Fluidigm) has been verified by applying droplet digital PCR (ddPCR) using the QX100 system (Bio-Rad). One of the critical factors in the measurement of copy number concentrations by digital PCR is the partition volume. Therefore, we determined the average droplet volume by optical microscopy, revealing an average droplet volume that is 8 % smaller than the droplet volume used as the defined parameter in the QuantaSoft software version 1.3.2.0 (Bio-Rad) to calculate the copy number concentration. This observation explains why copy number concentrations estimated with ddPCR and using an average droplet volume predefined in the QuantaSoft software were systematically lower than those measured by dPCR, creating a significant bias between the values obtained by these two techniques. The difference was not significant anymore when the measured droplet volume of 0.834 nL was used to estimate copy number concentrations. A new version of QuantaSoft software (version 1.6.6.0320), which has since been released with Bio-Rad's new QX200 systems and QX100 upgrades, uses a droplet volume of 0.85 nL as a defined parameter to calculate copy number concentration. PMID:25600685

  13. Report of the consultants' meeting on traceability of IAEA-AQCS reference materials to SI-units

    International Nuclear Information System (INIS)

    The purpose of the meeting was to discuss the present Agency's Analytical Quality Control Services (AQCS) procedure for the characterization of reference materials and to identify necessary improvements or changes needed to fulfill the requirements on traceability and uncertainty related to the property value of IAEA reference materials. This publication contains a summary of the discussions held at the meeting as well as specific recommendations made by the consultants. It also contains draft reports of two previous meetings and individual papers presented by the consultants at the meeting. These reports and papers have been provided with abstracts and indexed separately

  14. Sampling and sample preparation methods for the analysis of trace elements in biological material

    International Nuclear Information System (INIS)

    The authors attempt to give a most systamtic possible treatment of the sample taking and sample preparation of biological material (particularly in human medicine) for trace analysis (e.g. neutron activation analysis, atomic absorption spectrometry). Contamination and loss problems are discussed as well as the manifold problems of the different consistency of solid and liquid biological materials, as well as the stabilization of the sample material. The process of dry and wet ashing is particularly dealt with, where new methods are also described. (RB)

  15. Nano-FTIR chemical mapping of minerals in biological materials

    Directory of Open Access Journals (Sweden)

    Sergiu Amarie

    2012-04-01

    Full Text Available Methods for imaging of nanocomposites based on X-ray, electron, tunneling or force microscopy provide information about the shapes of nanoparticles; however, all of these methods fail on chemical recognition. Neither do they allow local identification of mineral type. We demonstrate that infrared near-field microscopy solves these requirements at 20 nm spatial resolution, highlighting, in its first application to natural nanostructures, the mineral particles in shell and bone. "Nano-FTIR" spectral images result from Fourier-transform infrared (FTIR spectroscopy combined with scattering scanning near-field optical microscopy (s-SNOM. On polished sections of Mytilus edulis shells we observe a reproducible vibrational (phonon resonance within all biocalcite microcrystals, and distinctly different spectra on bioaragonite. Surprisingly, we discover sparse, previously unknown, 20 nm thin nanoparticles with distinctly different spectra that are characteristic of crystalline phosphate. Multicomponent phosphate bands are observed on human tooth sections. These spectra vary characteristically near tubuli in dentin, proving a chemical or structural variation of the apatite nanocrystals. The infrared band strength correlates with the mineral density determined by electron microscopy. Since nano-FTIR sensitively responds to structural disorder it is well suited for the study of biomineral formation and aging. Generally, nano-FTIR is suitable for the analysis and identification of composite materials in any discipline, from testing during nanofabrication to even the clinical investigation of osteopathies.

  16. Chemical modifiers in arsenic determination in biological materials by tungsten coil electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Bruhn, C.G.; Huerta, V.N.; Neira, J.Y. [Departamento de Analisis Instrumental, Facultad de Farmacia, Universidad de Concepcion, P.O. Box 237, Concepcion (Chile)

    2004-01-01

    Palladium, iridium, and rhodium are evaluated as possible chemical modifiers in the determination of As in digest solutions of biological materials (human hair and clam) by tungsten coil electrothermal atomic absorption spectrophotometry (TCA-AAS). The modifier in solution was applied onto the coil and thermally pre-reduced; the pre-reduction conditions, the amount of modifier, and the thermal program were optimized. Palladium was not satisfactory, whereas Ir and Rh were effective modifiers and rendered better relative sensitivity for As by a factor of 1.4 and 1.9, respectively compared to the case without modifier. Upon optimization of thermal conditions for As in pre-reduced Ir (2.0 {mu}g) and Rh (2.0 {mu}g) modifiers and in the digest solutions of the study matrices, Rh (2.0 {mu}g) was more effective modifier and was selected as such. The mean within-day repeatability was 2.8% in consecutive measurements (25-100 {mu}g L{sup -1}) (3 cycles, each of n=6) and confirmed good short-term stability of the absorbance measurements. The mean reproducibility was 4.4% (n=20 in a 3-day period) and the detection limit (3{sigma}{sub blank}/slope) was 29 pg (n=15). The useful coil lifetime in Rh modifier was extended to 300-400 firings. Validation was by determination of As in the certified reference material (CRM) of ''Oyster tissue'' solution with a percentage relative error (E{sub rel}%) of 2% and percentage relative standard deviation (RSD%) of 3% (n=4), and by analytical recovery of As spiked in CRM of human hair [94{+-}8% (n=4)]. The methodology is simple, fast (sample readout frequency 21 h{sup -1}), reliable, of low cost, and was applied to the determination of As in hair samples of exposed and unexposed workers. (orig.)

  17. Use of water activity characteristics enables a simplified approach for defining the reference moisture condition for FDA cocoa powder in-house reference material.

    Science.gov (United States)

    Cunningham, W C

    2013-10-01

    The Food and Drug Administration uses water activity behavior characteristics when adjusting test portion mass to correct for the moisture condition of its cocoa powder in-house reference material. The cocoa powder's moisture condition, and therefore weight, equilibrates according to the relative humidity (RH) of its surroundings. This process is predictable and defined by an isotherm. The reference values in the certificate of analysis are relative to the material's condition at 30% RH, which is assumed to be mid-range for typical laboratory settings. Since mass variations are relatively small within a 15-50% RH range, the mass may be measured immediately after removing a test portion from a storage bottle and used without correction if a standard uncertainty of 0.7% is acceptable for the mass. If greater accuracy is needed and the laboratory RH is known, a very simple and quick procedure can be used whereby the test portion is left open and exposed to the laboratory air overnight before weighing. After applying a correction, the standard uncertainty for mass measurement drops to 0.3%. PMID:23942587

  18. Application of direct solid sample analysis for the determination of chlorine in biological materials using electrothermal vaporization inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Santos de Gois, Jefferson; Pereira, Éderson R. [Departamento de Química, Universidade Federal de Santa Catarina, 88040-970 Florianópolis, SC (Brazil); Welz, Bernhard [Departamento de Química, Universidade Federal de Santa Catarina, 88040-970 Florianópolis, SC (Brazil); INCT de Energia e Ambiente do CNPq (Brazil); Borges, Daniel L.G., E-mail: daniel.borges@ufsc.br [Departamento de Química, Universidade Federal de Santa Catarina, 88040-970 Florianópolis, SC (Brazil); INCT de Energia e Ambiente do CNPq (Brazil)

    2015-03-01

    This work describes a methodology developed to carry out Cl determination in biological materials using electrothermal vaporization inductively coupled plasma mass spectrometry and direct solid sample analysis. The solid samples were directly weighed into graphite ‘cups’ and inserted into the graphite furnace. The RF power and the carrier gas flow rate were optimized at 1300 W and 0.7 L min{sup −1}, respectively. Calibration could be carried out using aqueous standard solutions with pre-dried modifiers (Pd + Nd or Pd + Ca) or using solid certified reference materials with the same pre-dried modifiers or without the use of modifiers. The limit of quantification was determined as 5 μg g{sup −1} under optimized conditions and the Cl concentration was determined in five certified reference materials with certified concentrations for Cl, in addition to three certified reference materials, for which certified values for Cl were unavailable; in the latter case, the results were compared with those obtained using high-resolution continuum source molecular absorption spectrometry. Good agreement at a 95% statistical confidence level was achieved between determined and certified or reference values. - Highlights: • Direct determination of chlorine in solid biological materials is described for the first time using ICP-MS. • Calibration against aqueous standards is feasible. • The method is accurate and sensitive, regardless of the composition of the solid sample.

  19. Application of direct solid sample analysis for the determination of chlorine in biological materials using electrothermal vaporization inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    This work describes a methodology developed to carry out Cl determination in biological materials using electrothermal vaporization inductively coupled plasma mass spectrometry and direct solid sample analysis. The solid samples were directly weighed into graphite ‘cups’ and inserted into the graphite furnace. The RF power and the carrier gas flow rate were optimized at 1300 W and 0.7 L min−1, respectively. Calibration could be carried out using aqueous standard solutions with pre-dried modifiers (Pd + Nd or Pd + Ca) or using solid certified reference materials with the same pre-dried modifiers or without the use of modifiers. The limit of quantification was determined as 5 μg g−1 under optimized conditions and the Cl concentration was determined in five certified reference materials with certified concentrations for Cl, in addition to three certified reference materials, for which certified values for Cl were unavailable; in the latter case, the results were compared with those obtained using high-resolution continuum source molecular absorption spectrometry. Good agreement at a 95% statistical confidence level was achieved between determined and certified or reference values. - Highlights: • Direct determination of chlorine in solid biological materials is described for the first time using ICP-MS. • Calibration against aqueous standards is feasible. • The method is accurate and sensitive, regardless of the composition of the solid sample

  20. 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. PMID:27220526

  1. Ultrafast Spectroscopy in Conjugated Organic and Biological Materials

    Science.gov (United States)

    Yan, Ming

    The dynamics of two kinds of conjugated materials, the visual pigment rhodopsin and the organic polymer poly(p -phenylene vinylene), have been studied utilizing femtosecond spectroscopy. The 11-cis to all-trans torsional isomerization of the retinal chromophore in rhodopsin for both protonated and deuterated aqueous environments have been studied by time-resolved absorption measurements at room temperature. The kinetic results are well modeled by rate equations based on the scheme which involves the isomerization along the torsional coordinate of the 11-cis bond of the retinal chromophore. A metastable intermediate 90 degree twisted state is formed within 200 fs on the excited state surface by rotation around the C_{11} -C_{12} double bond, and it takes 3 ps to form the fully isomerized all -trans photoproduct known as bathorhodopsin and to repopulate the ground state rhodopsin. These results agree well with the semiempirical energy level and molecular dynamics calculations. The observed dynamics are insensitive to deuteration of the exchangeable protons which suggest that proton translocation is unimportant at physiological temperatures. The conjugated polymer, Poly(p-phenylene vinylene) (PPV) in a stretch oriented film, has been studied using polarized time-resolved absorption with subpicosecond resolution and transient luminescence measurements. Excitations are generated by photoexcitation near the band edge (500nm -540nm) with a 200 fs pulse and the resulting spectral changes are probed with a white light pulse. Lattice stabilized (singlet) self-trapped excitons are formed within 200 fs which are observed by measuring the stimulated gain in their emission band which decay at 10 ps. The agreement of the photoinduced exciton gain spectrum (luminescence spectrum (10 ps) and the steady state luminescence spectrum suggest that the singlet excitons are not further trapped after 200fs of their formation time. Excitation wavelength dependence measurements suggest that

  2. Finite element simulation for the mechanical characterization of soft biological materials by atomic force microscopy.

    Science.gov (United States)

    Valero, C; Navarro, B; Navajas, D; García-Aznar, J M

    2016-09-01

    The characterization of the mechanical properties of soft materials has been traditionally performed through uniaxial tensile tests. Nevertheless, this method cannot be applied to certain extremely soft materials, such as biological tissues or cells that cannot be properly subjected to these tests. Alternative non-destructive tests have been designed in recent years to determine the mechanical properties of soft biological tissues. One of these techniques is based on the use of atomic force microscopy (AFM) to perform nanoindentation tests. In this work, we investigated the mechanical response of soft biological materials to nanoindentation with spherical indenters using finite element simulations. We studied the responses of three different material constitutive laws (elastic, isotropic hyperelastic and anisotropic hyperelastic) under the same process and analyzed the differences thereof. Whereas linear elastic and isotropic hyperelastic materials can be studied using an axisymmetric simplification, anisotropic hyperelastic materials require three-dimensional analyses. Moreover, we established the limiting sample size required to determine the mechanical properties of soft materials while avoiding boundary effects. Finally, we compared the results obtained by simulation with an estimate obtained from Hertz theory. Hertz theory does not distinguish between the different material constitutive laws, and thus, we proposed corrections to improve the quantitative measurement of specific material properties by nanoindentation experiments.

  3. Finite element simulation for the mechanical characterization of soft biological materials by atomic force microscopy.

    Science.gov (United States)

    Valero, C; Navarro, B; Navajas, D; García-Aznar, J M

    2016-09-01

    The characterization of the mechanical properties of soft materials has been traditionally performed through uniaxial tensile tests. Nevertheless, this method cannot be applied to certain extremely soft materials, such as biological tissues or cells that cannot be properly subjected to these tests. Alternative non-destructive tests have been designed in recent years to determine the mechanical properties of soft biological tissues. One of these techniques is based on the use of atomic force microscopy (AFM) to perform nanoindentation tests. In this work, we investigated the mechanical response of soft biological materials to nanoindentation with spherical indenters using finite element simulations. We studied the responses of three different material constitutive laws (elastic, isotropic hyperelastic and anisotropic hyperelastic) under the same process and analyzed the differences thereof. Whereas linear elastic and isotropic hyperelastic materials can be studied using an axisymmetric simplification, anisotropic hyperelastic materials require three-dimensional analyses. Moreover, we established the limiting sample size required to determine the mechanical properties of soft materials while avoiding boundary effects. Finally, we compared the results obtained by simulation with an estimate obtained from Hertz theory. Hertz theory does not distinguish between the different material constitutive laws, and thus, we proposed corrections to improve the quantitative measurement of specific material properties by nanoindentation experiments. PMID:27214690

  4. 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.

  5. 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. PMID:26434333

  6. 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…

  7. 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...

  8. 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. PMID:25172706

  9. The characterization of uranium and plutonium reference materials by the (100-X) route; basic principle and applications

    International Nuclear Information System (INIS)

    Uranium and plutonium reference materials are produced to calibrate reagents used in titrimetric methods or to check instrumental techniques like electrochemical methods. For this purpose, the most commonly prepared reference materials are high-purity uranium metal pieces and uranium dioxide pellets, respectively plutonium metal pieces and plutonium dioxide powders. Two different routes can be followed to certify the element content: a direct or an indirect route. With the direct route the main element is assayed using appropriate redox titration methods. The overall uncertainty on the main element is limited by both the precision of the titration methods used and the uncertainty of the reference materials. The indirect route is applicable only for high purity base material. It requires the measurement of the sum of impurities (X) in the material and the substraction of this sum from hundred per cent (100-X). Since the (100-X) route requires the measurement of a large number of elements, a variety of analytical methods has to be used, and a contribution by different specialized laboratories is requested. The uncertainty of the total of impurities is calculated from the respective uncertainties of the determination of each specific element. If the total of impurities is sufficiently small and even if it is determined with a rather large uncertainty, the (100-X) route leads nevertheless to a low uncertainty on the main element content. The application of the (100-X) route is illustrated for the case of uranium dioxide pellets certified as an European Community Nuclear Reference Material. The (100-X) route is recommended as a very accurate one for high purity material characterization and certification purposes

  10. Evaluation of geologic materials to limit biological intrusion into low-level radioactive waste disposal sites

    Energy Technology Data Exchange (ETDEWEB)

    Hakonson, T.E.

    1986-02-01

    This report describes the results of a three-year research program to evaluate the performance of selected soil and rock trench cap designs in limiting biological intrusion into simulated waste. The report is divided into three sections including a discussion of background material on biological interactions with waste site trench caps, a presentation of experimental data from field studies conducted at several scales, and a final section on the interpretation and limitations of the data including implications for the user.

  11. Evaluation of geologic materials to limit biological intrusion into low-level radioactive waste disposal sites

    International Nuclear Information System (INIS)

    This report describes the results of a three-year research program to evaluate the performance of selected soil and rock trench cap designs in limiting biological intrusion into simulated waste. The report is divided into three sections including a discussion of background material on biological interactions with waste site trench caps, a presentation of experimental data from field studies conducted at several scales, and a final section on the interpretation and limitations of the data including implications for the user

  12. Metrological aspects related to stable isotope reference materials: the traceability concept and uncertainty evaluation scheme supporting every day practice.

    Science.gov (United States)

    Assonov, Sergey; Groening, Manfred; Fajgelj, Ales

    2016-04-01

    The worldwide metrological comparability of stable isotope measurement results is presently achieved by linking them to the conventional delta scales. Delta scales are realized by scale defining reference materials, most of them being supplied by the IAEA (examples are VSMOW2 & SLAP2). In fact, these reference materials are artefacts, characterized by a network of laboratories using the current best measurement practice. In reality any measurement result is linked to the scale via reference materials (RMs) in use. Any RMs is traceable to the highest-level RMs which define the scale; this is valid not only for international RMs (mostly secondary RMs like IAEA-CH-7, NBS22) but for any lab standard calibrated by users. This is a basic of measurement traceability. The traceability scheme allows addressing both the comparability and long-term compatibility of measurement results. Correspondingly, the uncertainty of any measurement result has to be propagated up to the scale level. The uncertainty evaluation should include (i) the uncertainty of the RMs in use; (ii) the analytical uncertainty of the materials used in calibration runs performed at the user laboratory; (iii) the reproducibility on results obtained on sample material; (iv) the uncertainty of corrections applied (memory, drift, etc). Besides these, there may be other uncertainty components of to be considered. The presentation will illustrate the metrological concepts involved (comparability, traceability etc) and give a generic scheme for the uncertainty evaluation.

  13. The Principle of Integration in International Sustainable Development Law (ISDL with Reference to the Biological Weapons Convention (BWC

    Directory of Open Access Journals (Sweden)

    Marina Abdul Majid

    2016-02-01

    Full Text Available The Biological Weapons Convention (BWC does not explicitly refer to sustainable development despite the fact that other United Nations (UN disarmament documents prescribe that international environmental law principles and sustainable development be considered among arms control agreements. This study’s objective is to utilize the principle of integration’s three components of environmental, economic, and social development, as found in the International Sustainable Development Law (ISDL from the New Delhi Declaration (Delhi Declaration of Principles of International Law Relating to Sustainable Development, in order to evaluate whether the BWC contains such components; thereby, making it possible for the BWC to contribute to sustainable development. The methodology of this study is necessarily qualitative, given that it is a socio-legal research that relies on international agreements such as the BWC, declarations, resolutions, plans of implementation, other non-binding documents of the UN, and secondary resources—all of which are analyzed through a document analysis. The results show that the BWC addresses the environment (Article II, prohibits transfers relating to export controls, international trade, and economic development (Article III, while at the same time, covering social development concerns, health, and diseases that make up the international social law (Article X. Since the BWC is found to be capable of contributing to sustainable development, it is concluded that ISDL cannot be restricted to international environmental, economic, and social law, but should be expanded to include international arms control law.

  14. The Widespread Prevalence and Functional Significance of Silk-Like Structural Proteins in Metazoan Biological Materials.

    Science.gov (United States)

    McDougall, Carmel; Woodcroft, Ben J; Degnan, Bernard M

    2016-01-01

    In nature, numerous mechanisms have evolved by which organisms fabricate biological structures with an impressive array of physical characteristics. Some examples of metazoan biological materials include the highly elastic byssal threads by which bivalves attach themselves to rocks, biomineralized structures that form the skeletons of various animals, and spider silks that are renowned for their exceptional strength and elasticity. The remarkable properties of silks, which are perhaps the best studied biological materials, are the result of the highly repetitive, modular, and biased amino acid composition of the proteins that compose them. Interestingly, similar levels of modularity/repetitiveness and similar bias in amino acid compositions have been reported in proteins that are components of structural materials in other organisms, however the exact nature and extent of this similarity, and its functional and evolutionary relevance, is unknown. Here, we investigate this similarity and use sequence features common to silks and other known structural proteins to develop a bioinformatics-based method to identify similar proteins from large-scale transcriptome and whole-genome datasets. We show that a large number of proteins identified using this method have roles in biological material formation throughout the animal kingdom. Despite the similarity in sequence characteristics, most of the silk-like structural proteins (SLSPs) identified in this study appear to have evolved independently and are restricted to a particular animal lineage. Although the exact function of many of these SLSPs is unknown, the apparent independent evolution of proteins with similar sequence characteristics in divergent lineages suggests that these features are important for the assembly of biological materials. The identification of these characteristics enable the generation of testable hypotheses regarding the mechanisms by which these proteins assemble and direct the construction of

  15. The Widespread Prevalence and Functional Significance of Silk-Like Structural Proteins in Metazoan Biological Materials.

    Directory of Open Access Journals (Sweden)

    Carmel McDougall

    Full Text Available In nature, numerous mechanisms have evolved by which organisms fabricate biological structures with an impressive array of physical characteristics. Some examples of metazoan biological materials include the highly elastic byssal threads by which bivalves attach themselves to rocks, biomineralized structures that form the skeletons of various animals, and spider silks that are renowned for their exceptional strength and elasticity. The remarkable properties of silks, which are perhaps the best studied biological materials, are the result of the highly repetitive, modular, and biased amino acid composition of the proteins that compose them. Interestingly, similar levels of modularity/repetitiveness and similar bias in amino acid compositions have been reported in proteins that are components of structural materials in other organisms, however the exact nature and extent of this similarity, and its functional and evolutionary relevance, is unknown. Here, we investigate this similarity and use sequence features common to silks and other known structural proteins to develop a bioinformatics-based method to identify similar proteins from large-scale transcriptome and whole-genome datasets. We show that a large number of proteins identified using this method have roles in biological material formation throughout the animal kingdom. Despite the similarity in sequence characteristics, most of the silk-like structural proteins (SLSPs identified in this study appear to have evolved independently and are restricted to a particular animal lineage. Although the exact function of many of these SLSPs is unknown, the apparent independent evolution of proteins with similar sequence characteristics in divergent lineages suggests that these features are important for the assembly of biological materials. The identification of these characteristics enable the generation of testable hypotheses regarding the mechanisms by which these proteins assemble and direct the

  16. The Widespread Prevalence and Functional Significance of Silk-Like Structural Proteins in Metazoan Biological Materials

    Science.gov (United States)

    McDougall, Carmel; Woodcroft, Ben J.

    2016-01-01

    In nature, numerous mechanisms have evolved by which organisms fabricate biological structures with an impressive array of physical characteristics. Some examples of metazoan biological materials include the highly elastic byssal threads by which bivalves attach themselves to rocks, biomineralized structures that form the skeletons of various animals, and spider silks that are renowned for their exceptional strength and elasticity. The remarkable properties of silks, which are perhaps the best studied biological materials, are the result of the highly repetitive, modular, and biased amino acid composition of the proteins that compose them. Interestingly, similar levels of modularity/repetitiveness and similar bias in amino acid compositions have been reported in proteins that are components of structural materials in other organisms, however the exact nature and extent of this similarity, and its functional and evolutionary relevance, is unknown. Here, we investigate this similarity and use sequence features common to silks and other known structural proteins to develop a bioinformatics-based method to identify similar proteins from large-scale transcriptome and whole-genome datasets. We show that a large number of proteins identified using this method have roles in biological material formation throughout the animal kingdom. Despite the similarity in sequence characteristics, most of the silk-like structural proteins (SLSPs) identified in this study appear to have evolved independently and are restricted to a particular animal lineage. Although the exact function of many of these SLSPs is unknown, the apparent independent evolution of proteins with similar sequence characteristics in divergent lineages suggests that these features are important for the assembly of biological materials. The identification of these characteristics enable the generation of testable hypotheses regarding the mechanisms by which these proteins assemble and direct the construction of

  17. Body mass and body weight: a dual reference system in biology Masa y peso corporales: un sistema dual de referencia en biología

    Directory of Open Access Journals (Sweden)

    BRUNO GÜNTHER

    2003-03-01

    Full Text Available ABSTRACT The aim of the present study was to compare two different biological similarity criteria, one was based on body mass (M as a theoretical reference system in accordance with the MLT-system of physics, while the other utilized the body weight (W for the same purpose. The mass-dependent allometry should be applied during space flights as well as during fetal and newborn conditions of life, whereas the weight-dependence should prevail in earth-bound physiology. The above mentioned distinctions are relevant not only for the specific metabolic rates but also for numerous biological time functions, as for instance for the heart and respiratory rates of all mammals, whose allometric exponent is b = - 0.09 during fetal life, and b = - 0.25 in all adult specimens.El objetivo del presente trabajo fue la comparación de dos diferentes criterios de similitud, uno basado en la masa corporal (M como sistema teórico de referencia de acuerdo con el sistema MLT de la Física, en tanto que el otro utilizó el peso corporal (W con este mismo propósito. La alometría dependiente de la masa debería aplicarse durante los vuelos espaciales así como durante la vida fetal y la condición de recién nacido, en tanto que la dependencia del peso debe prevalecer en la fisiología terrestre. La distinción antes mencionada es relevante, no sólo para el metabolismo específico y también para numerosas funciones biológicas en relación con funciones de tiempo, como ser con las frecuencias cardiaca y respiratoria de todos los mamíferos cuyo exponente alométrico es b = - 0,09 durante la vida fetal, y b = - 0,25 en todos los especimenes adultos.

  18. 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.

  19. Membrane materials for storing biological samples intended for comparative nanotoxicological testing

    Science.gov (United States)

    Metelkin, A.; Kuznetsov, D.; Kolesnikov, E.; Chuprunov, K.; Kondakov, S.; Osipov, A.; Samsonova, J.

    2015-11-01

    The study is aimed at identifying the samples of most promising membrane materials for storing dry specimens of biological fluids (Dried Blood Spots, DBS technology). Existing sampling systems using cellulose fiber filter paper have a number of drawbacks such as uneven distribution of the sample spot, dependence of the spot spreading area on the individual biosample properties, incomplete washing-off of the sample due to partially inconvertible sorption of blood components on cellulose fibers, etc. Samples of membrane materials based on cellulose, polymers and glass fiber with applied biosamples were studied using methods of scanning electron microscopy, FT-IR spectroscopy and surface-wetting measurement. It was discovered that cellulose-based membrane materials sorb components of biological fluids inside their structure, while membranes based on glass fiber display almost no interaction with the samples and biological fluid components dry to films in the membrane pores between the structural fibers. This characteristic, together with the fact that membrane materials based on glass fiber possess sufficient strength, high wetting properties and good storage capacity, attests them as promising material for dry samples of biological fluids storage systems.

  20. Caracterização detalhada de material de referência certificado de carvão brasileiro

    Directory of Open Access Journals (Sweden)

    Vera L. V. Fallavena

    2013-01-01

    Full Text Available The use and characterization of the first Certified Reference Material (CRM of Brazilian coal for analytical quality control are presented. All results were determined within the limits of repeatability and reproducibility allowed under the standards. Notable among the characterization parameters was the mineral matter content (45.39% obtained by an alternative procedure showing a low relative error (-2.1% compared to the standard technique (low ashing temperature. The possible expanded application of this CRM application in national laboratories, beyond the certificated and reference parameters, has advantages such as lower cost and easy availability, but round robin tests must be performed.

  1. A study of mechanical behavior of rock-fill materials with reference to particle crushing

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In rock-fill dams of 200 to 300 m high,maximum compressive stress can exceed 6MPa.At such a high stress level,rock-fill materials may experience particle crushing during shear.The material behavior is highly sophisticated exhibiting pressure and density dependency as well as particle crushing effects.Through scrutinizing the relevant experimental data on rock-fill materials and sands published in the literatures,this paper is focused on understanding basic mechanical characteristics of this sort of materials in the light of constitutive modelling.

  2. Propulsion of swimming microrobots inspired by metachronal waves in ciliates: from biology to material specifications

    OpenAIRE

    Palagi, Stefano; Jager, Edwin; Mazzolai, Barbara; Beccai, Lucia

    2013-01-01

    The quest for swimming microrobots originates from possible applications in medicine, especially involving navigation in bodily fluids. Swimming microorganisms have become a source of inspiration because their propulsion mechanisms are effective in the low-Reynolds number regime. In this study, we address a propulsion mechanism inspired by metachronal waves, i.e. the spontaneous coordination of cilia leading to the fast swimming of ciliates. We analyse the biological mechanism (referring to i...

  3. Preparation of zirconium and zirconium-base alloy certified reference materials JAERI-Z11 to -Z18

    International Nuclear Information System (INIS)

    The Second Sub-Committee on Zircaloy Analysis was organized in April, 1978, under the Committee on Analytical Chemistry on Nuclear Fuels and Reactor Materials, JAERI, for the renewal of zirconium and zirconium-base alloy certified reference materials ( CRM's). The Sub-Committee decided certified values of major constituents and impurities in eight reference materials ( JAERI -Z11 to -Z18 ) in July, 1983, based on the results obtained by cooperative analysis during 1978 to 1983. CRM's JAERI-Z11 to -Z14 are Zircaloy-2 in the form of disk, 32 mm in diameter and 20 mm in thickness, and useful primarily for fluorescent X-ray and emission spectrographic analysis. CRMs JAERI-Z15 and -Z16 are zirconium in the form of plate, 30 mm square and 2 mm in the thickness, and specially designed for the analysis of hafnium at trace levels : 2 to 40 μg/g. CRM's JAERI -Z17 and -Z18 are Zircaloy-2 and -4, respectively, in the form of chips, packed in a glass bottle of which content is 25 g and useful for the analysis of carbon in Zircaloy. This report describes mainly preparation of certified reference materials, and homogeneity test by neutron activation analysis and fluorescent X-ray spectrometry. CRMs JAERI-Z11 to -Z14 have been distributed with provisional certificate since July, 1979. (author)

  4. The preparation and analysis of minerals for use as reference material

    International Nuclear Information System (INIS)

    This report covers the progress made in the collection of reference samples, and describes the completion of the five interlaboratory analytical programmes (those on ferrochromium slags, fluorspar, 'mixed' NIMROC samples, rare earths, and ferromanganese slags). A comprehensive tabulation of the samples that have been evaluated, and a list of the samples that have not been evaluated are included

  5. Developing a Reference Material for Diffusion-Controlled Formaldehyde Emissions Testing

    Science.gov (United States)

    Emissions of formaldehyde from building materials can contaminate indoor air and create significant risks to human health. The need to control formaldehyde emissions from indoor materials is made more urgent by the prevailing drive to improve building energy by decreasing ventil...

  6. Nutrition Education Materials and Audiovisuals for Grades Preschool through 6. Special Reference Briefs Series.

    Science.gov (United States)

    Evans, Shirley King, Comp.

    This bibliography was prepared for educators interested in nutrition education materials, audiovisuals, and resources for classroom use. Items listed cover a range of topics including general nutrition, food preparation, food science, and dietary management. Teaching materials listed include food models, games, kits, videocassettes, and lesson…

  7. Current studies of biological materials using instrumental and radiochemical neutron activation analysis

    International Nuclear Information System (INIS)

    Instrumental neutron activation analysis still remains the preferred option when analysing the trace element distribution in a wide rage of materials by neutron activation analysis. However, when lower limits of detection are required or major interferences reduce the effectiveness of this technique, radiochemical neutron activation analysis is applied. This paper examines the current use of both methods and the development of rapid radiochemical techniques for analysis of the biological materials, hair, cow's milk, human's milk, milk powder, blood and blood serum

  8. 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

  9. Wetland Biomass Production: emergent aquatic management options and evaluations. A final subcontract report. [Includes a bibliography containing 686 references on Typha from biological abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Pratt, D.C.; Dubbe, D.R.; Garver, E.G.; Linton, P.J.

    1984-07-01

    The high yield potential and attractive chemical composition of Typha make it a particularly viable energy crop. The Minnesota research effort has demonstrated that total annual biomass yields equivalent to 30 dry tonnes/ha (13 tons/acre) are possible in planted stands. This compares with yields of total plant material between 9 and 16 dry tonnes/ha (4 to 7 tons/acre) in a typical Minnesota corn field. At least 50% of the Typha plant is comprised of a belowground rhizome system containing 40% starch and sugar. This high level of easily fermentable carbohydrate makes rhizomes an attractive feedstock for alcohol production. The aboveground portion of the plant is largely cellulose, and although it is not easily fermentable, it can be gasified or burned. This report is organized in a manner that focuses on the evaluation of the management options task. Results from stand management research performed at the University of Minnesota during 1982 and 1983 are integrated with findings from an extensive survey of relevant emergent aquatic plant research and utilization. These results and findings are then arranged in sections dealing with key steps and issues that need to be dealt with in the development of a managed emergent aquatic bio-energy system. A brief section evaluating the current status of rhizome harvesting is also included along with an indexed bibliography of the biology, ecology, and utilization of Typha which was completed with support from this SERI subcontract. 686 references, 11 figures, 17 tables.

  10. Measuring the complex permittivity tensor of uniaxial biological materials with coplanar waveguide transmission line

    Science.gov (United States)

    A simple and accurate technique is described for measuring the uniaxial permittivity tensor of biological materials with a coplanar waveguide transmission-line configuration. Permittivity tensor results are presented for several chicken and beef fresh meat samples at 2.45 GHz....

  11. Evaluation of precision and accuracy of selenium measurements in biological materials using neutron activation analysis

    International Nuclear Information System (INIS)

    In recent years, the accurate determination of selenium in biological materials has become increasingly important in view of the essential nature of this element for human nutrition and its possible role as a protective agent against cancer. Unfortunately, the accurate determination of selenium in biological materials is often difficult for most analytical techniques for a variety of reasons, including interferences, complicated selenium chemistry due to the presence of this element in multiple oxidation states and in a variety of different organic species, stability and resistance to destruction of some of these organo-selenium species during acid dissolution, volatility of some selenium compounds, and potential for contamination. Neutron activation analysis (NAA) can be one of the best analytical techniques for selenium determinations in biological materials for a number of reasons. Currently, precision at the 1% level (1s) and overall accuracy at the 1 to 2% level (95% confidence interval) can be attained at the U.S. National Bureau of Standards (NBS) for selenium determinations in biological materials when counting statistics are not limiting (using the 75Se isotope). An example of this level of precision and accuracy is summarized. Achieving this level of accuracy, however, requires strict attention to all sources of systematic error. Precise and accurate results can also be obtained after radiochemical separations

  12. X-ray spectrometric determination of thorium in bone and other biological materials

    International Nuclear Information System (INIS)

    An x-ray spectrometric method has been developed for the determination of thorium in bone and other biological materials. The limit of detection at the 95% confidence level is 20 ng. This corresponds to a concentration of 2 ppb in a 10-g sample of bone ash

  13. Selenium determination in biological material by atomic absorption spectrophotometry in graphite furnace and using vapor generation

    International Nuclear Information System (INIS)

    The applicability of the atomic absorption spectrophotometry to the determination of selenium in biological material using vapor generation and electrothermal atomization in the graphite furnace was investigated. Instrumental parameters and the analytical conditions of the methods were studied. Decomposition methods for the samples were tested, and the combustion in the Wickbold apparatus was chosen. (author)

  14. New materials and biologically active preparations on the basis of (organilthio) chloroacetylene

    Institute of Scientific and Technical Information of China (English)

    D'yachkova; S.; G.

    2005-01-01

    (Organylthio)chloroacetylenes [RSC≡CCl, 1], the object of our systematic research, provide a promising source of new classes of polyfunctional compounds of acetylenic and polyheterocyclic seriesamong which biologically active substances, monomers and precursors for the preparation of new materials possessing a whole complex of valuable properties have been recognized.……

  15. New materials and biologically active preparations on the basis of (organilthio) chloroacetylene

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ (Organylthio)chloroacetylenes [RSC≡CCl, 1], the object of our systematic research, provide a promising source of new classes of polyfunctional compounds of acetylenic and polyheterocyclic seriesamong which biologically active substances, monomers and precursors for the preparation of new materials possessing a whole complex of valuable properties have been recognized.

  16. Simultaneous Determination of Arsenic, Manganese, and Selenium in Biological Materials by Neutron-Activation Analysis

    DEFF Research Database (Denmark)

    Heydorn, Kaj; Damsgaard, Else

    1973-01-01

    A new method was developed for the simultaneous determination of arsenic, manganese, and selenium in biological material by thermal-neutron activation analysis. The use of 81 mSe as indicator for selenium permitted a reduction of activation time to 1 hr for a 1 g sample, and the possibility of loss...

  17. Occupational accidents with exposure to biological material: Description of cases in Bahia

    Directory of Open Access Journals (Sweden)

    Técia Maria Santos Carneiro e Cordeiro

    2016-04-01

    Full Text Available Background and Objective: This study is included in the field of public health in Brazil, in particular occupational health, by the occupational accidents with exposure to biological material consists of a preventable injury. Thus, the objective was to describe risk factors the of occupational accidents with exposure to biological material and the conduct postexposure adopted notified of cases in Notifiable Diseases Information System (SINAN in the State of Bahia in 2012. Methods: This is a descriptive epidemiological study realized with data from the injuries of notifications SINAN in February 2013, the analysis was realized using descriptive statistics in absolute frequencies and relative. Results: The results indicate a higher occurrence of occupational accidents involving exposure to biological materials in Bahia in the female population (78.1% and aged between 30-49 years (51.5%; the blood was fluid larger contact in accidents 75.2% by percutaneous (71.5%; post-exposure procedures were adopted in accordance recommended by the Ministry of Health; divers information were not fulfilled in the notifications and only 23.8% of Occupational Accidents Comunication (CAT were issued. Conclusion: It is considered necessary to draw up strategies on occupational health and safety, consciousness of workers about the relevance of the measures adopted after occupational accidents with exposure to biological material and the training of professionals for case notification and research to fill all the fields of the notification form and also the issuance of CAT.

  18. Environmental impacts of post-consumer material managements: recycling, biological treatments, incineration.

    Science.gov (United States)

    Valerio, F

    2010-11-01

    The environmental impacts of recycling, mechanical biological treatments (MBT) and waste-to-energy incineration, the main management strategies to respond to the increasing production of post-consumer materials are reviewed and compared. Several studies carried out according to life-cycle assessment (LCA) confirm that the lowest environmental impact, on a global scale, is obtained by recycling and by biological treatments (composting and anaerobic fermentations) if compost is used in agriculture. The available air emission factors suggest that, on a local scale, mechanical biological treatments with energy recovery of biogas, may be intrinsically safer than waste-to-energy incinerators. Several studies confirm the capability of biological treatments to degrade many toxic xenobiotic contaminating urban wastes such as dioxins and polycyclic aromatic hydrocarbons, an important property to be improved, for safe agricultural use of compost. Further LCA studies to compare the environmental impact of MBTs and of waste-to-energy incinerators are recommended.

  19. Development of certified matrix reference materials for quality assurance of screening 134Cs and 137Cs in food

    International Nuclear Information System (INIS)

    A certified reference material using activated alumina powder certified for activity of 134Cs and 137Cs was developed. The results of the verification and the certification are described. The certified reference material can be used for quality assurance of screening activity measurements of 134Cs and 137Cs in food/foodstuffs. Commercially available equipments were experimentally tested using the CRM and another CRM including 40K. The results of these tests are also shown. - Highlights: • CRM of 134Cs and 137Cs using activated alumina was developed. • CRM including 134Cs, 137Cs and 40K was also developed. • Results of experimental performance test of commercial inspection equipments using CRMs were shown

  20. Fluorescence anisotropy measurements in solution: Methods and reference materials (IUPAC Technical Report)

    OpenAIRE

    Ameloot, Marcel; vandeVen, Martin; Ulises Acuna, A.; Valeur, Bernard

    2013-01-01

    After recalling the basic relations relevant to both steady-state and time-resolved fluorescence polarization, it is shown how the values of steady-state polarized intensities recorded experimentally usually need to be corrected for systematic effects and errors, caused by instrumentation and sample properties. A list of selected reference values of steady-state fluorescence anisotropy and polarization is given. Attention is also paid to analysis of time-resolved fluorescence anisotropy data ...

  1. Intralaboratory comparison experiments for plutonium determination in working reference material K4Pu (SO4)4: coulometry and biamperometry

    International Nuclear Information System (INIS)

    Accurate and precise determination of Pu in reactor fuel materials is essential for the characterization of the fuel as well as for fissile material accounting. Electroanalytical methods like Coulometry, Potentiometry , and Biamperometry based on the redox reactions are widely employed for determination of Pu at milligram levels. Controlled potential coulometry is a well established routinely employed technique for precise and accurate determination of plutonium. A biamperometric method based on the Pu(VI)-Pu(IV) redox couple has been in routine use for Pu determination in a variety of nuclear fuel materials in our laboratory for past 25 years. In order to validate the status of the methodologies employed for Pu determination an intralaboratory comparison experiments involving Pu determination in working reference material K4Pu(SO4)4 was conducted. Results of these studies are presented in this paper

  2. The role of instrumental activation analysis in the verification and completion of analytical data of rock reference materials

    International Nuclear Information System (INIS)

    Ten selected rock reference materials (USGS diabase W-l, basalt BCR-1, andesite AGV-1, granite G-2, granodiorite GSP-1, and CRPG basalt BE-N, granite GS-N, trachyte ISH-G, serpentine UB-N, glass standard VS-N) were analyzed by instrumental neutron and photon activation analyses. The results were evaluated on average for the entire set of samples to detect possible systematic deviations of the determined values from the reference values. Out of 47 elements determined, 43 elements were determined with reasonable agreement (deviation <10% on average) with the reference values. Au could not be determined because of a high blank from packaging polyethylene foil. Systematically higher Dy and lower Ho and Tm (by about 20 % on average) in our results require further investigation. In several cases, reasons for greater differences between the determined and recommended values could not be traced in our procedures. The most suspect is the recommended value for W in the CRPG BE-N basalt, which is twenty-five times higher than the value determined in the present work, probably due to inconsistent contamination from a W carbide mill used in production of this reference material. (author)

  3. 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

    . 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.......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...

  4. Synthesis of Precision for the Certification of Phosphorus in Biological Materials by INAA

    DEFF Research Database (Denmark)

    Damsgaard, E.; Heydorn, K.

    1987-01-01

    The β-emitter32P was used to determine total phosphorus by INAA in Skim Milk Powder RM 63, a material now certified by the EEC Bureau of Reference (BCR). Samples and comparator were irradiated in the Danish reactor DR 3. One month later the samples were dissolved in water and aliquots counted...

  5. 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...... 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...

  6. 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.

  7. Caracterização detalhada de material de referência certificado de carvão brasileiro

    OpenAIRE

    Vera L. V. Fallavena; Cristiane S. de Abreu; Taísi D. Inácio; Marçal Pires; Carla M. N. Azevedo; Iolanda D. Fernandes; Lizete S. Ferret; M. Rosa Martinez Tarazona

    2013-01-01

    The use and characterization of the first Certified Reference Material (CRM) of Brazilian coal for analytical quality control are presented. All results were determined within the limits of repeatability and reproducibility allowed under the standards. Notable among the characterization parameters was the mineral matter content (45.39%) obtained by an alternative procedure showing a low relative error (-2.1%) compared to the standard technique (low ashing temperature). The possible expanded a...

  8. 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.

  9. Immobilized Biofilm in Thermophilic Biohydrogen Production using Synthetic versus Biological Materials

    Directory of Open Access Journals (Sweden)

    Jaruwan Wongthanate

    2015-02-01

    Full Text Available Biohydrogen production was studied from the vermicelli processing wastewater using synthetic and biological materials as immobilizing substrate employing a mixed culture in a batch reactor operated at the initial pH 6.0 and thermophilic condition (55 ± 1ºC. Maximum cumulative hydrogen production (1,210 mL H2/L wastewater was observed at 5% (v/v addition of ring-shaped synthetic material, which was the ring-shaped hydrophobic acrylic. Regarding 5% (v/v addition of synthetic and biological materials, the maximum cumulative hydrogen production using immobilizing synthetic material of ball-shaped hydrophobic polyethylene (HBPE (1,256.5 mL H2/L wastewater was a two-fold increase of cumulative hydrogen production when compared to its production using immobilizing biological material of rope-shaped hydrophilic ramie (609.8 mL H2/L wastewater. SEM observation of immobilized biofilm on a ball-shaped HBPE or a rope-shaped hydrophilic ramie was the rod shape and gathered into group.

  10. Combating illicit trafficking in nuclear and other radioactive material. Technical guidance. Reference manual. (Chinese Edition)

    International Nuclear Information System (INIS)

    This publication is intended for individuals and organizations that may be called upon to deal with the detection of and response to criminal or unauthorized acts involving nuclear or other radioactive material. It will also be useful for legislators, law enforcement agencies, government officials, technical experts, lawyers, diplomats and users of nuclear technology. This manual emphasizes the international initiatives for improving the security of nuclear and other radioactive material. However, it is recognized that effective measures for controlling the transfer of equipment, non-nuclear material, technology or information that may assist in the development of nuclear explosive devices, improvised nuclear devices (INDs) or other radiological dispersal devices (RDDs) are important elements of an effective nuclear security system. In addition, issues of personal integrity, inspection and investigative procedures are not discussed in this manual, all of which are essential elements for an effective overall security system. The manual considers a variety of elements that are recognized as being essential for dealing with incidents of criminal or unauthorized acts involving nuclear and other radioactive material. Depending on conditions in a specific State, including its legal and governmental infrastructure, some of the measures discussed will need to be adapted to suit that State's circumstances. However, much of the material can be applied directly in the context of other national programmes. This manual is divided into four main parts. Section 2 discusses the threat posed by criminal or unauthorized acts involving nuclear and other radioactive material, as well as the policy and legal bases underlying the international effort to restrain such activities. Sections 3 and 4 summarize the major international undertakings in the field. Sections 5-8 provide some basic technical information on radiation, radioactive material, the health consequences of radiation

  11. HRI catalytic two-stage liquefaction (CTSL) process materials: chemical analysis and biological testing

    Energy Technology Data Exchange (ETDEWEB)

    Wright, C.W.; Later, D.W.

    1985-12-01

    This report presents data from the chemical analysis and biological testing of coal liquefaction materials obtained from the Hydrocarbon Research, Incorporated (HRI) catalytic two-stage liquefaction (CTSL) process. Materials from both an experimental run and a 25-day demonstration run were analyzed. Chemical methods of analysis included adsorption column chromatography, high-resolution gas chromatography, gas chromatography/mass spectrometry, low-voltage probe-inlet mass spectrometry, and proton nuclear magnetic resonance spectroscopy. The biological activity was evaluated using the standard microbial mutagenicity assay and an initiation/promotion assay for mouse-skin tumorigenicity. Where applicable, the results obtained from the analyses of the CTSL materials have been compared to those obtained from the integrated and nonintegrated two-stage coal liquefaction processes. 18 refs., 26 figs., 22 tabs.

  12. Use of 15N in nitrification inhibitor studies with special reference to indigenous materials

    International Nuclear Information System (INIS)

    Non-edible oil seed cakes and their constituents have been advantageously used for increasing the efficiency of fertilizer nitrogen (N) for crop production. The beneficial effects of these materials have been attributed to retardation of nitrification, which lessen the loss of N associated with nitrification by leaching and denitrification in situations where these losses are high. However, it is possible that some of the effects of these materials could be due to immobilization-remineralization of N particularly when the carbonaceous materials are added with fertilizers at high rates. A methodology involving the use of 15N-labelled fertilizers is advanced to sort out whether the beneficial effects of non-edible oil seed cakes and other materials are due to retardation of nitrification and or immobilization-remineralization of fertilizer N. Using the proposed technique it would be possible to make realistic evaluation of the wealth of indigenous products as nitrification inhibitors. Following the proposed approach it would also be possible to widen the scope and depth of research in this area for ultimately better exploitation of indigenous materials as nitrification inhibitors. (author). 18 refs

  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. 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

  15. Kant's Understanding of the Enlightenment with Reference to his Refutation of Materialism

    OpenAIRE

    Paola Rumore

    2014-01-01

    The paper focuses on the role of Kant’s refutation of materialism in his understanding of the Enlightenment, meant to be the necessary condition that allows human beings to express their proper dignity, i.e. to cultivate the urge for and the vocation of free thought. Sketching the main moments of the German struggle against the threat of materialism, the paper places Kant’s refutation within this tradition, and reconstructs the steps of his critique from the very beginning of his ...

  16. 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.)

  17. Thermo-fluidic devices and materials inspired from mass and energy transport phenomena in biological system

    Institute of Scientific and Technical Information of China (English)

    Jian XIAO; Jing LIU

    2009-01-01

    Mass and energy transport consists of one of the most significant physiological processes in nature, which guarantees many amazing biological phenomena and activ-ities. Borrowing such idea, many state-of-the-art thermo-fluidic devices and materials such as artificial kidneys, carrier erythrocyte, blood substitutes and so on have been successfully invented. Besides, new emerging technologies are still being developed. This paper is dedicated to present-ing a relatively complete review of the typical devices and materials in clinical use inspired by biological mass and energy transport mechanisms. Particularly, these artificial thermo-fluidic devices and materials will be categorized into organ transplantation, drug delivery, nutrient transport, micro operation, and power supply. Potential approaches for innovating conventional technologies were discussed, corresponding biological phenomena and physical mechan-isms were interpreted, future promising mass-and-energy-transport-based bionic devices were suggested, and prospects along this direction were pointed out. It is expected that many artificial devices based on biological mass and energy transport principle will appear to better improve vari-ous fields related to human life in the near future.

  18. Adolescent Mental Health: Selected Materials from the NCEMCH Reference Collection, April 1997.

    Science.gov (United States)

    National Center for Education in Maternal and Child Health, Arlington, VA.

    Items in this annotated bibliography deal with the mental health of adolescents and include materials for adolescents, parents, health educators, and health professionals. Resources cited include 11 videotapes and 64 publications dealing with the following topics: (1) teenage suicide; (2) mental illness in the family; (3) coping; (4) teenage…

  19. Kant's Understanding of the Enlightenment with Reference to his Refutation of Materialism

    Directory of Open Access Journals (Sweden)

    Paola Rumore

    2014-11-01

    Full Text Available The paper focuses on the role of Kant’s refutation of materialism in his understanding of the Enlightenment, meant to be the necessary condition that allows human beings to express their proper dignity, i.e. to cultivate the urge for and the vocation of free thought. Sketching the main moments of the German struggle against the threat of materialism, the paper places Kant’s refutation within this tradition, and reconstructs the steps of his critique from the very beginning of his reflection – still dealing with the main topics of Wolff’s metaphysic – up to the definitive refutation he develops on the basis of the transcendental idealism of the first Critique. The shift from the «obscure reasons» pointed out in the Dreams, that allow a refutation of materialism on moral grounds, to the statement of the meaninglessness of the question in a transcendental perspective reveals that the attempt to find a solution to the problem of materialism – most of all in its psychological meaning –represents a neverending challenge within Kant’s reflection.

  20. Development of a certified reference material for the content of nitroimidazole parent drugs and hydroxy metabolites in pork meat.

    Science.gov (United States)

    Zeleny, R; Schimmel, H; Ulberth, F; Emons, H

    2009-02-23

    Nitroimidazoles have been applied in the past to poultry and pigs to treat protozoan diseases and to combat bacterial infections, but due to adverse health effects their use in food-producing animals has meanwhile been banned in the EU. The request for a certified reference material in a representative matrix was stipulated by the responsible Community Reference Laboratory and is underpinned by the need to improve the accuracy and comparability of measurement data and to establish metrological traceability of analytical results. The Institute for Reference Materials and Measurements (IRMM) has responded to this demand by developing and producing a new certified matrix reference material, ERM-BB124. This incurred lyophilised pork meat material was certified according to ISO guides 34 and 35 for the mass fractions of six nitroimidazole compounds. Processing of the frozen muscle tissue to the final material was accomplished by application of cutting, freeze-drying, mixing and milling techniques. Homogeneity and stability measurements were performed using liquid chromatography tandem mass spectrometry. The relative standard uncertainty due to possible heterogeneity showed to be below 1.8% for all analytes. Potential degradation during transport and storage was assessed by isochronous stability studies. No significant instability was detected at a storage temperature of -20 degrees C for a shelf-life of 2 years. The certified mass fraction values were assigned upon evaluation of the data acquired in an international laboratory inter-comparison involving 12 expert laboratories using different sample preparation procedures, but exclusively LC-MS/MS methods. Relative standard uncertainty contributions for the characterisation (between-lab variation of mean values) were found to be between 1.6 and 4.8%. Certified values for five analytes were in the range of 0.7 to 6.2 microg kg(-1), with expanded relative uncertainties ranging between 7 and 14%. Dimetridazole could be

  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

    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.

  2. 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.

  3. Two-stage coal liquefaction process materials from the Wilsonville Facility operated in the nonintegrated and integrated modes: chemical analyses and biological testing

    Energy Technology Data Exchange (ETDEWEB)

    Later, D.W.

    1985-01-01

    This document reports the results from chemical analyses and biological testing of process materials sampled during operation of the Wilsonville Advanced Coal Liquefaction Research and Development Facility (Wilsonville, Alabama) in both the noncoupled or nonintegrated (NTSL Run 241) and coupled or integrated (ITSL Run 242) two-stage liquefaction operating modes. Mutagenicity and carcinogenicity assays were conducted in conjunction with chromatographic and mass spectrometric analyses to provide detailed, comparative chemical and biological assessments of several NTSL and ITSL process materials. In general, the NTSL process materials were biologically more active and chemically more refractory than analogous ITSL process materials. To provide perspective, the NTSL and ITSL results are compared with those from similar testing and analyses of other direct coal liquefaction materials from the solvent refined coal (SRC) I, SRC II and EDS processes. Comparisons are also made between two-stage coal liquefaction materials from the Wilsonville pilot plant and the C.E. Lummus PDU-ITSL Facility in an effort to assess scale-up effects in these two similar processes. 36 references, 26 figures, 37 tables.

  4. 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

  5. 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.

  6. Dynamics of a material point in a noninertial frame of reference

    Energy Technology Data Exchange (ETDEWEB)

    Verozub, L.V. (Khar' kovskij Gosudarstvennyj Univ. (Ukrainian SSR))

    1981-10-01

    Elements of material point dynamics in noninertial counting systems (NCS), where space-time is suggested to be pseudofinsler, are investigated. Considered were methods analogous for inertial counting systems for description of the physical system state change in time and based on equations of motion for dynamical variables and on the Hamilton-Jakobi equations. It is shown, in particular, that the presence of inertial forces in NCS may be interpreted as manifestation of difference of space-time in the latter from pseudoeuclidean. Such interpretation is alternative to the known interpretation of inertial forces in NCS as hypothetical force effect of the rest substance of Universe.

  7. 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.

  8. 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.

  9. 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.

  10. Novel microwave near-field sensors for material characterization, biology, and nanotechnology

    CERN Document Server

    Joffe, R; Shavit, R

    2015-01-01

    The wide range of interesting electromagnetic behavior of contemporary materials requires that experimentalists working in this field master many diverse measurement techniques and have a broad understanding of condensed matter physics and biophysics. Measurement of the electromagnetic response of materials at microwave frequencies is important for both fundamental and practical reasons. In this paper, we propose a novel near-field microwave sensor with application to material characterization, biology, and nanotechnology. The sensor is based on a subwavelength ferrite-disk resonator with magnetic-dipolar-mode (MDM) oscillations. Strong energy concentration and unique topological structures of the near fields originated from the MDM resonators allow effective measuring material parameters in microwaves, both for ordinary structures and objects with chiral properties.

  11. Clinical treatment adherence of health care workers and students exposed to potentially infectious biological material

    Directory of Open Access Journals (Sweden)

    Maria Cristina Mendes de Almeida

    2015-04-01

    Full Text Available OBJECTIVE To assess adherence to clinical appointments by health care workers (HCW and students who suffered accidents with potentially infectious biological material. METHOD A retrospective cross-sectional study that assessed clinical records of accidents involving biological material between 2005 and 2010 in a specialized unit. RESULTS A total of 461 individuals exposed to biological material were treated, of which 389 (84.4% were HCWs and 72 (15.6% students. Of the 461 exposed individuals, 307 (66.6% attended a follow-up appointment. Individuals who had suffered an accident with a known source patient were 29 times more likely to show up to their scheduled follow-up appointments (OR: 29.98; CI95%: 16.09-55.83. CONCLUSION The predictor in both univariate and multivariate analyses for adherence to clinical follow-up appointment was having a known source patient with nonreactive serology for the human immunodeficiency virus and/or hepatitis B and C.

  12. 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

  13. 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.

  14. The need for and the importance of biological indicators of radiation effects with special reference to injuries in radiation accidents

    International Nuclear Information System (INIS)

    The need for further research on the existing and new biological indicators of radiation injury has been expressed. The studies on the radiation-induced alterations of membrane structure and function stimulated investigations aiming to develop an indicator based on membrane-phenomena. The co-ordinated research programme on ''Cell Membrane Probes as Biological Indicators of Radiation Injury in Radiation Accidents'' was initiated in mid 1977 and terminated in 1980. Within this programme many basic observations were made in connection with altered features of various animal and human cell membranes. Molecular, biophysical, biochemical and cell biological approaches were performed. The rapid reaction within minutes or hours of membranes against relatively low doses of various types of irradiations were described and the effects proved to be transitory, i.e. membrane regeneration occurred within hours. These dose- and timedependent alterations suggest the possibility of developing a biological indicator which would give signals at the earliest period after radiation injury when no other biological informations are available. The importance of a system of biological indicators is emphasized. (author)

  15. Solid phase speciation of arsenic by sequential extraction in standard reference materials and industrially contaminated soil samples

    Energy Technology Data Exchange (ETDEWEB)

    Herreweghe, Samuel van; Swennen, Rudy; Vandecasteele, Carlo; Cappuyns, Valerie

    2003-04-01

    Leaching experiments, a mineralogical survey and larger samples are preferred when arsenic is present as discrete mineral phases. - Availability, mobility, (phyto)toxicity and potential risk of contaminants is strongly affected by the manner of appearance of elements, the so-called speciation. Operational fractionation methods like sequential extractions have been applied for a long time to determine the solid phase speciation of heavy metals since direct determination of specific chemical compounds can not always be easily achieved. The three-step sequential extraction scheme recommended by the BCR and two extraction schemes based on the phosphorus-like protocol proposed by Manful (1992, Occurrence and Ecochemical Behaviours of Arsenic in a Goldsmelter Impacted Area in Ghana, PhD dissertation, at the RUG) were applied to four standard reference materials (SRM) and to a batch of samples from industrially contaminated sites, heavily contaminated with arsenic and heavy metals. The SRM 2710 (Montana soil) was found to be the most useful reference material for metal (Mn, Cu, Zn, As, Cd and Pb) fractionation using the BCR sequential extraction procedure. Two sequential extraction schemes were developed and compared for arsenic with the aim to establish a better fractionation and recovery rate than the BCR-scheme for this element in the SRM samples. The major part of arsenic was released from the heavily contaminated samples after NaOH-extraction. Inferior extraction variability and recovery in the heavily contaminated samples compared to SRMs could be mainly contributed to subsample heterogeneity.

  16. Solid phase speciation of arsenic by sequential extraction in standard reference materials and industrially contaminated soil samples

    International Nuclear Information System (INIS)

    Leaching experiments, a mineralogical survey and larger samples are preferred when arsenic is present as discrete mineral phases. - Availability, mobility, (phyto)toxicity and potential risk of contaminants is strongly affected by the manner of appearance of elements, the so-called speciation. Operational fractionation methods like sequential extractions have been applied for a long time to determine the solid phase speciation of heavy metals since direct determination of specific chemical compounds can not always be easily achieved. The three-step sequential extraction scheme recommended by the BCR and two extraction schemes based on the phosphorus-like protocol proposed by Manful (1992, Occurrence and Ecochemical Behaviours of Arsenic in a Goldsmelter Impacted Area in Ghana, PhD dissertation, at the RUG) were applied to four standard reference materials (SRM) and to a batch of samples from industrially contaminated sites, heavily contaminated with arsenic and heavy metals. The SRM 2710 (Montana soil) was found to be the most useful reference material for metal (Mn, Cu, Zn, As, Cd and Pb) fractionation using the BCR sequential extraction procedure. Two sequential extraction schemes were developed and compared for arsenic with the aim to establish a better fractionation and recovery rate than the BCR-scheme for this element in the SRM samples. The major part of arsenic was released from the heavily contaminated samples after NaOH-extraction. Inferior extraction variability and recovery in the heavily contaminated samples compared to SRMs could be mainly contributed to subsample heterogeneity

  17. 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.

  18. Production and characterization of APAT-RM004 (compost) and APAT-RM005 (agricultural soil) matrix reference materials

    International Nuclear Information System (INIS)

    Compost is the decomposed remnants of organic materials (usually those with plant origins) and it is used in gardening and agriculture, mixed in with the soil. It improves soil structure, increases the amount of organic matter, and provides nutrients. Compost is a common name for humus, which is the result of the decomposition of organic matter. Generally, compost is the raw material obtained by the aerobic decomposition of the organic residues of the municipal waste or of the vegetable market waste. Composting is the industrial operation to produce compost on a large scale and it is the controlled decomposition technique of organic matter. Rather than allowing nature to take its slow course, a composter provides an optimal environment in which decomposer can thrive. The compost raw material used to prepare the APAT-RM004 reference material has been obtained from an aerobic composting plant located near Rome (Italy). This plant produces compost from organic waste originating from municipal routine plant trimmings, pruning, lawn mowing and wastes deriving from vegetable markets. The homogeneity test was carried out on 10 different units (bottles) sequentially selected over the whole bottling process. This study has been carried by measuring the total contents of C by CHN-S considering a sample intake of 0.02g and by the determination of the Hg content by direct mercury analyzer (DMA-80) considering a sample intake of 0.5g. Both techniques achieve high precision levels and require little or no sample processing prior to analysis

  19. Preparation of biological samples for transmission X-ray microanalysis: a review of alternative procedures to the use of sectioned material

    International Nuclear Information System (INIS)

    Although transmission X-ray microanalysis of biological material has traditionally been carried out mainly on sectioned preparations, a number of alternative procedures exist. These are considered under three major headings - whole cell preparations, analysis of cell homogenates and biological fluids, and applications of the technique to microsamples of purified biochemicals. These three aspects provide a continuous range of investigative level - from the cellular to the molecular. The use of X-ray microanalysis with whole cell preparations is considered in reference to eukaryote (animal) cells and prokaryotes - where it has particular potential in environmental studies on bacteria. In the case of cell homogenates and biological fluids, the technique has been used mainly with microdroplets of animal material. The use of X-ray microanalysis with purified biochemicals is considered in relation to both particulate and non-particulate samples. In the latter category, the application of this technique for analysis of thin films of metalloprotein is particularly emphasised. It is concluded that wider use could be made of the range of preparative techniques available - both within a particular investigation, and in diverse fields of study. Transmission X-ray microanalysis has implications for environmental, physiological and molecular biology as well as cell biology

  20. 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. PMID:24004454

  1. Development and Applications Of Photosensitive Device Systems To Studies Of Biological And Organic Materials

    Energy Technology Data Exchange (ETDEWEB)

    Gruner, Sol

    2012-01-20

    The primary focus of the grant is the development of new x-ray detectors for biological and materials work at synchrotron sources, especially Pixel Array Detectors (PADs), and the training of students via research applications to problems in biophysics and materials science using novel x-ray methods. This Final Progress Report provides a high-level overview of the most important accomplishments. These major areas of accomplishment include: (1) Development and application of x-ray Pixel Array Detectors; (2) Development and application of methods of high pressure x-ray crystallography as applied to proteins; (3) Studies on the synthesis and structure of novel mesophase materials derived from block co-polymers.

  2. Enhanced Removal of Lead by Chemically and Biologically Treated Carbonaceous Materials

    Directory of Open Access Journals (Sweden)

    Mohamed E. Mahmoud

    2012-01-01

    Full Text Available Hybrid sorbents and biosorbents were synthesized via chemical and biological treatment of active carbon by simple and direct redox reaction followed by surface loading of baker’s yeast. Surface functionality and morphology of chemically and biologically modified sorbents and biosorbents were studied by Fourier Transform Infrared analysis and scanning electron microscope imaging. Hybrid carbonaceous sorbents and biosorbents were characterized by excellent efficiency and superiority toward lead(II sorption compared to blank active carbon providing a maximum sorption capacity of lead(II ion as 500 μmol g−1. Sorption processes of lead(II by these hybrid materials were investigated under the influence of several controlling parameters such as pH, contact time, mass of sorbent and biosorbent, lead(II concentration, and foreign ions. Lead(II sorption mechanisms were found to obey the Langmuir and BET isotherm models. The potential applications of chemically and biologically modified-active carbonaceous materials for removal and extraction of lead from real water matrices were also studied via a double-stage microcolumn technique. The results of this study were found to denote to superior recovery values of lead (95.0–99.0±3.0–5.0% by various carbonaceous-modified-bakers yeast biosorbents.

  3. Marketing the use of the space environment for the processing of biological and pharmaceutical materials

    Science.gov (United States)

    1984-01-01

    The perceptions of U.S. biotechnology and pharmaceutical companies concerning the potential use of the space environment for the processing of biological substances was examined. Physical phenomena that may be important in space-base processing of biological materials are identified and discussed in the context of past and current experiment programs. The capabilities of NASA to support future research and development, and to engage in cooperative risk sharing programs with industry are discussed. Meetings were held with several biotechnology and pharmaceutical companies to provide data for an analysis of the attitudes and perceptions of these industries toward the use of the space environment. Recommendations are made for actions that might be taken by NASA to facilitate the marketing of the use of the space environment, and in particular the Space Shuttle, to the biotechnology and pharmaceutical industries.

  4. Damage-free vibrational spectroscopy of biological materials in the electron microscope

    Science.gov (United States)

    Rez, Peter; Aoki, Toshihiro; March, Katia; Gur, Dvir; Krivanek, Ondrej L.; Dellby, Niklas; Lovejoy, Tracy C.; Wolf, Sharon G.; Cohen, Hagai

    2016-03-01

    Vibrational spectroscopy in the electron microscope would be transformative in the study of biological samples, provided that radiation damage could be prevented. However, electron beams typically create high-energy excitations that severely accelerate sample degradation. Here this major difficulty is overcome using an `aloof' electron beam, positioned tens of nanometres away from the sample: high-energy excitations are suppressed, while vibrational modes of energies guanine crystals in their native state, resolving their characteristic C-H, N-H and C=O vibrational signatures with no observable radiation damage. The technique opens up the possibility of non-damaging compositional analyses of organic functional groups, including non-crystalline biological materials, at a spatial resolution of ~10 nm, simultaneously combined with imaging in the electron microscope.

  5. Possibilities of nondestructive determination of fluorine in coal and biological materials by IPAA

    International Nuclear Information System (INIS)

    The possibilities of nondestructive determination of fluorine in coal and biological materials by instrumental photon activation analysis (IPAA) were studied. The determination was based on counting the non-specific 511 keV annihilation gamma rays of 18F, a pure positron emitter which is the product of the photonuclear reaction 19F(γ, n)18F. The simultaneous formation of some additional positron emitters, particularly 45Ti and 34mCl, is an interfering factor. When using correction standards for Ti and Cl and optimization of the beam energy and irradiation-decay-counting times, fluorine could be determined by IPAA in selected coal and biological samples at the ten ppm level. The feasibility of additional optimization for further improvements of the proposed IPAA procedure are discussed

  6. Exploring matter through photons and neutrons: from biological molecules to designer materials

    International Nuclear Information System (INIS)

    Understanding structure-property relationships of naturally occurring materials has been the aim of scientific research for centuries. The discovery of short wavelength x-rays and neutrons in the 20th century provided a means of studying molecular structure. The methodology of x-ray and neutron diffraction has been successfully applied to determine structures of molecules across disciplines of physics, chemistry, biology, biochemistry and medicine. Typical applications in physics include study of phase transformations, elasticity measurements, magnetic structure, surface scattering etc. In chemistry, the applications have ranged from routine structure determinations of reaction intermediates or natural products to refinement of quantum chemical parameters of atomic and molecular charge densities. The science of crystallography has had a profound effect on the disciplines of biology and medicine. A whole new discipline and industry was created when the structure of DNA was discovered through x-ray diffraction

  7. Development of Standards for NanoSIMS Analyses of Biological Materials

    Energy Technology Data Exchange (ETDEWEB)

    Davission, M L; Weber, P K; Pett-Ridge, J; Singer, S

    2008-07-31

    NanoSIMS is a powerful analytical technique for investigating element distributions at the nanometer scale, but quantifying elemental abundances requires appropriate standards, which are not readily available for biological materials. Standards for trace element analyses have been extensively developed for secondary ion mass spectrometry (SIMS) in the semiconductor industry and in the geological sciences. The three primary approaches for generating standards for SIMS are: (1) ion implantation (2) using previously characterized natural materials, and (3) preparing synthetic substances. Ion implantation is a reliable method for generating trace element standards, but it is expensive, which limits investigation of the analytical issues discussed above. It also requires low background levels of the elements of interest. Finding or making standard materials has the potential to provide more flexibility than ion implantation, but realizing homogeneity at the nano-scale is in itself a significant challenge. In this study, we experiment with all three approaches, but with an emphasis toward synthetic organic polymers in order to reduce costs, increase flexibility, and achieve a wide dynamic concentration range. This emphasis serves to meet the major challenge for biological samples of identifying matrix matched, homogeneous material. Biological samples themselves are typically heterogeneous at the scale of microns to 100s of microns, and therefore they are poor SIMS standards. Therefore, we focused on identifying 'biological-like' materials--either natural or synthetic--that can be used for standards. The primary criterion is that the material be as compositionally similar to biological samples as possible (primarily C, H, O, and N). For natural material we adsorbed organic colloids consisting of peptidoglycan (i.e., amino sugars), activated charcoal, and humic acids. Experiments conducted with Si on peptidoglycan showed low affinity as SiO{sub 2}, yet its

  8. Biological and Biomimetic Low-Temperature Routes to Materials for Energy Applications

    Energy Technology Data Exchange (ETDEWEB)

    Morse, Daniel E. [Univ. of California, Santa Barbara, CA (United States). Inst. for Collaborative Biotechnologies

    2016-08-29

    New materials are needed to significantly improve the efficiencies of energy harnessing, transduction and storage, yet the synthesis of advanced composites and multi-metallic semiconductors with nanostructures optimized for these functions remains poorly understood and even less well controlled. To help address this need, we proposed three goals: (1) to further investigate the hierarchical structure of the biologically synthesized silica comprising the skeletal spicules of sponges that we discovered, to better resolve the role and mechanism of templating by the hierarchically assembled silicatein protein filament; (2) to extend our molecular and genetic analyses and engineering of silicatein, the self-assembling, structure-directing, silica-synthesizing enzyme we discovered and characterized, to better understand and manipulate the catalysis and templating of semiconductor synthesis,; and (3) to further investigate, scale up and harness the biologically inspired, low-temperature, kinetically controlled catalytic synthesis method we developed (based on the mechanism we discovered in silicatein) to investigate the kinetic control of the structure-function relationships in magnetic materials, and develop new materials for energy applications. The bio-inspired catalytic synthesis method we have developed is low-cost, low temperature, and operates without the use of polluting chemicals. In addition to direct applications for improvement of batteries and fuel cells, the broader impact of this research includes a deeper fundamental understanding of the factors governing kinetically controlled synthesis and its control of the emergent nanostructure and performance of a wide range of nanomaterials for energy applications.

  9. "Rinse and trickle": a protocol for TEM preparation and investigation of inorganic fibers from biological material.

    Science.gov (United States)

    Vigliaturo, Ruggero; Capella, Silvana; Rinaudo, Caterina; Belluso, Elena

    2016-07-01

    The purpose of this work is to define a sample preparation protocol that allows inorganic fibers and particulate matter extracted from different biological samples to be characterized morphologically, crystallographically and chemically by transmission electron microscopy-energy dispersive spectroscopy (TEM-EDS). The method does not damage or create artifacts through chemical attacks of the target material. A fairly rapid specimen preparation is applied with the aim of performing as few steps as possible to transfer the withdrawn inorganic matter onto the TEM grid. The biological sample is previously digested chemically by NaClO. The salt is then removed through a series of centrifugation and rinse cycles in deionized water, thus drastically reducing the digestive power of the NaClO and concentrating the fibers for TEM analysis. The concept of equivalent hydrodynamic diameter is introduced to calculate the settling velocity during the centrifugation cycles. This technique is applicable to lung tissues and can be extended to a wide range of organic materials. The procedure does not appear to cause morphological damage to the fibers or modify their chemistry or degree of crystallinity. The extrapolated data can be used in interdisciplinary studies to understand the pathological effects caused by inorganic materials. PMID:27151190

  10. Biomolecular Interactions and Biological Responses of Emerging Two-Dimensional Materials and Aromatic Amino Acid Complexes.

    Science.gov (United States)

    Mallineni, Sai Sunil Kumar; Shannahan, Jonathan; Raghavendra, Achyut J; Rao, Apparao M; Brown, Jared M; Podila, Ramakrishna

    2016-07-01

    The present work experimentally investigates the interaction of aromatic amino acids viz., tyrosine, tryptophan, and phenylalnine with novel two-dimensional (2D) materials including graphene, graphene oxide (GO), and boron nitride (BN). Photoluminescence, micro-Raman spectroscopy, and cyclic voltammetry were employed to investigate the nature of interactions and possible charge transfer between 2D materials and amino acids. Graphene and GO were found to interact strongly with aromatic amino acids through π-π stacking, charge transfer, and H-bonding. Particularly, it was observed that both physi and chemisorption are prominent in the interactions of GO/graphene with phenylalanine and tryptophan while tyrosine exhibited strong chemisorption on graphene and GO. In contrast, BN exhibited little or no interactions, which could be attributed to localized π-electron clouds around N atoms in BN lattice. Lastly, the adsorption of amino acids on 2D materials was observed to considerably change their biological response in terms of reactive oxygen species generation. More importantly, these changes in the biological response followed the same trends observed in the physi and chemisorption measurements. PMID:27281436

  11. Interpreting atomic force microscopy nanoindentation of hierarchical biological materials using multi-regime analysis.

    Science.gov (United States)

    Bonilla, M R; Stokes, J R; Gidley, M J; Yakubov, G E

    2015-02-01

    We present a novel Multi-Regime Analysis (MRA) routine for interpreting force indentation measurements of soft materials using atomic force microscopy. The MRA approach combines both well established and semi-empirical theories of contact mechanics within a single framework to deconvolute highly complex and non-linear force-indentation curves. The fundamental assumption in the present form of the model is that each structural contribution to the mechanical response acts in series with other 'mechanical resistors'. This simplification enables interpretation of the micromechanical properties of materials with hierarchical structures and it allows automated processing of large data sets, which is particularly indispensable for biological systems. We validate the algorithm by demonstrating for the first time that the elastic modulus of polydimethylsiloxane (PDMS) films is accurately predicted from both approach and retraction branches of force-indentation curves. For biological systems with complex hierarchical structures, we show the unique capability of MRA to map the micromechanics of live plant cells, revealing an intricate sequence of mechanical deformations resolved with precision that is unattainable using conventional methods of analysis. We recommend the routine use of MRA to interpret AFM force-indentation measurements for other complex soft materials including mammalian cells, bacteria and nanomaterials. PMID:25569139

  12. 2012 best practices for repositories collection, storage, retrieval, and distribution of biological materials for research international society for biological and environmental repositories.

    Science.gov (United States)

    2012-04-01

    Third Edition [Formula: see text] [Box: see text] Printed with permission from the International Society for Biological and Environmental Repositories (ISBER) © 2011 ISBER All Rights Reserved Editor-in-Chief Lori D. Campbell, PhD Associate Editors Fay Betsou, PhD Debra Leiolani Garcia, MPA Judith G. Giri, PhD Karen E. Pitt, PhD Rebecca S. Pugh, MS Katherine C. Sexton, MBA Amy P.N. Skubitz, PhD Stella B. Somiari, PhD Individual Contributors to the Third Edition Jonas Astrin, Susan Baker, Thomas J. Barr, Erica Benson, Mark Cada, Lori Campbell, Antonio Hugo Jose Froes Marques Campos, David Carpentieri, Omoshile Clement, Domenico Coppola, Yvonne De Souza, Paul Fearn, Kelly Feil, Debra Garcia, Judith Giri, William E. Grizzle, Kathleen Groover, Keith Harding, Edward Kaercher, Joseph Kessler, Sarah Loud, Hannah Maynor, Kevin McCluskey, Kevin Meagher, Cheryl Michels, Lisa Miranda, Judy Muller-Cohn, Rolf Muller, James O'Sullivan, Karen Pitt, Rebecca Pugh, Rivka Ravid, Katherine Sexton, Ricardo Luis A. Silva, Frank Simione, Amy Skubitz, Stella Somiari, Frans van der Horst, Gavin Welch, Andy Zaayenga 2012 Best Practices for Repositories: Collection, Storage, Retrieval and Distribution of Biological Materials for Research INTERNATIONAL SOCIETY FOR BIOLOGICAL AND ENVIRONMENTAL REPOSITORIES (ISBER) INTRODUCTION T he availability of high quality biological and environmental specimens for research purposes requires the development of standardized methods for collection, long-term storage, retrieval and distribution of specimens that will enable their future use. Sharing successful strategies for accomplishing this goal is one of the driving forces for the International Society for Biological and Environmental Repositories (ISBER). For more information about ISBER see www.isber.org . ISBER's Best Practices for Repositories (Best Practices) reflect the collective experience of its members and has received broad input from other repository professionals. Throughout this document

  13. Analytical methods for determination of terbinafine hydrochloride in pharmaceuticals and biological materials$

    Institute of Scientific and Technical Information of China (English)

    Basavaiah Kanakapura n; Vamsi Krishna Penmatsa

    2016-01-01

    Terbinafine is a new powerful antifungal agent indicated for both oral and topical treatment of myco-sessince. It is highly effective in the treatment of determatomycoses. The chemical and pharmaceutical analysis of the drug requires effective analytical methods for quality control and pharmacodynamic and pharmacokinetic studies. Ever since it was introduced as an effective antifungal agent, many methods have been developed and validated for its assay in pharmaceuticals and biological materials. This article reviews the various methods reported during the last 25 years.

  14. Imaging material properties of biological samples with a Force Feedback Microscope

    CERN Document Server

    Costa, Luca; Newman, Emily; Zubieta, Chloe; Chevrier, Joel; Comin, Fabio

    2013-01-01

    Mechanical properties of biological samples have been imaged with a force feedback microscope. The force, force gradient and the dissipation are simultaneously measured quantitatively from solely the knowledge of the spring constant. The results are preliminary but demonstrate that the method can be used to measure material properties, it is robust and produce quantitative high force resolution measurements of interaction characteristics. The small stiffness and oscillation of the cantilever results in an vibrational energy much smaller than the thermal energy, reducing the interaction to a minimum. Because the lever is over-damped, the excitation frequency can be chosen arbitrarily.

  15. Computer-assisted reactor NAA of geological and other reference materials, using the ksub(o)-standardization method

    International Nuclear Information System (INIS)

    USGS BCR-1 and G-2, NBS 1633a Coal Fly-Ash and a 7-element synthetic standard for biological materials were analyzed by reactor NAA, using the ksub(o)-standardization method. The analyses were performed independently in the analytical laboratories of the Institute for Nuclear Sciences (INW), Gent, and the Central Research Institute for Physics (KFKI), Budapest. This procedure allowed not only a comparison with the specified data or with other published values, but enabled a check of the consistency of our own results obtained in largely different experimental conditions. As concluded, the ksub(o)-standardization method combines general versatility (with respect to irradiation and counting conditions) with good accuracy, while the experimental work remains as simple as possible. Since the ksub(o) method is a computer-oriented technique, a FORTRAN IV program was designed and applied on a VAX 11/780 machine. (author)

  16. Estimates of direct biological transport of radioactive waste in the deep sea with special reference to organic carbon budgets

    International Nuclear Information System (INIS)

    Calculations can be made for the maximum theoretical transport of pollutants such as radionuclides by movement of organisms out of a deep-sea benthic boundary layer dump site based on a presumption of a steady state organic carbon budget and estimated biological concentration factors. A calculated flux rate depends on the difference between a limiting input of organic matter and that carbon used by the biota or accumulating in the sediment. On average, the potential biological mass transport is low compared to physical transport. Exceptions to this generalization are possible in the far field after spatial gradients are obliterated or if natural mass migrations or periodic spawning concentrations occur in the near field. Biologically mediated fluxes of contaminants due to mixing of sediments by bioturbation or vertical flux due to scavenging by sinking particles are significant for movements of pollutants to and from sediments. These pathways contribute to the direct input of contaminants into food webs which may contain harvestable species. These fluxes are unimportant for mass transfers in the ocean but they determine the exposure of critical groups to contaminants

  17. 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.

  18. DIRECT DETERMINATION OF GOLD IN SUSPENSIONS OF ROCK AND ORE REFERENCE MATERIALS USING ELECTROTHERMAL HIGH RESOLUTION ATOMIC ABSORPTION SPECTROMETRY

    OpenAIRE

    Zakharov, Y. А.; Irisov, D. S.; Okunev, R. V.; Musin, R. Kh.; Haibullin, R. R.

    2014-01-01

    High resolution continuum source atomic absorption spectrometer ContrAA-700 with graphite furnace is used for direct gold determination in rocks and ores on the level 10-6-10-3 % mas. Russian standard reference materials of gold containing ore СЗР-4 (2.13 ± 0.05 g/ton), black slates of Sykhoy Log СЛг-1 (2.50 ± 0.03 g/ton) and СЧС-1 (0.10 ± 0.02 g/ton) in mass 1 mg was inserted into the furnace in the suspension form prepared on the mix of concentrated HNO3 and HCl (1:3) with following sevenfo...

  19. 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.

  20. 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,...

  1. 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

  2. Biologic

    CERN Document Server

    Kauffman, L H

    2002-01-01

    In this paper we explore the boundary between biology and the study of formal systems (logic). In the end, we arrive at a summary formalism, a chapter in "boundary mathematics" where there are not only containers but also extainers ><, entities open to interaction and distinguishing the space that they are not. The boundary algebra of containers and extainers is to biologic what boolean algebra is to classical logic. We show how this formalism encompasses significant parts of the logic of DNA replication, the Dirac formalism for quantum mechanics, formalisms for protein folding and the basic structure of the Temperley Lieb algebra at the foundations of topological invariants of knots and links.

  3. Radiochemical method for the simultaneous determination of 233U, 236U, 237Np, 236Pu, 238Pu, and 239Pu in biological materials

    International Nuclear Information System (INIS)

    A radiochemical method has been developed for the determination of multiple isotopes of uranium, neptunium, and plutonium in biological materials. The elements are separated from the other sample constituents and from each other by anion exchange in halide media. Their recoveries are monitored by isotopic diluents. The amounts of the analyte and diluent isotopes of each element are measured alpha spectrometrically. The interelemental separation factors are generally greater than 102, and the recovery of each element ranges from 60% to 90%. 4 references, 1 table

  4. Validation of a liquid chromatographic method for determination of related substances in a candidate certified reference material of captopril

    Directory of Open Access Journals (Sweden)

    Raquel Nogueira

    2011-06-01

    Full Text Available This paper describes the validation of a reversed-phase high performance liquid chromatography method (RP-HPLC with diode array detection (DAD for determination of related substances (impurities from organic synthesis and degradation products of captopril according to the Brazilian Pharmacopeia IV. The aim of this study was to guarantee the method accuracy for quantification of related substances, an essential requisite to determine, using the mass balance approach, the captopril content in the first Brazilian certified reference material (CRM of an active pharmaceutical ingredient (API, developed by Inmetro. The captopril instability in solution is discussed and the captopril content determined by mass balance is compared to the results from titration and differential scanning calorimetry (DSC.Este artigo descreve a validação de método de cromatografia líquida de alta eficiência em fase reversa (CLAE-RP com detector de fotodiodos (DAD para determinação de substâncias relacionadas (impurezas orgânicas de síntese e produtos de degradação de captopril segundo Farmacopéia Brasileira IV ed. Este estudo teve como objetivo garantir que o método é capaz de quantificar com exatidão o teor de substâncias relacionadas, um requisito essencial para que o teor de captopril seja determinado por balanço de massa no primeiro material de referência certificado (MRC de fármacos brasileiro, o qual foi desenvolvido pelo Inmetro. A instabilidade do captopril em solução é discutida em detalhes e o teor de captopril determinado por balanço de massa é comparado com aqueles obtidos por titulação e por calorimetria exploratória diferencial (DSC.

  5. Application of X ray fluorescence techniques for the determination of hazardous and essential trace elements in environmental and biological materials

    International Nuclear Information System (INIS)

    Full text: The utilization of X ray fluorescence (XRF) technique for the determination of trace element concentrations in environmental and biological samples is presented. The analytical methods used include energy dispersive X ray fluorescence (EDXRF), total reflection X ray fluorescence (TXRF), micro-beam X ray fluorescence and direct in situ X-ray fluorescence analysis. The measurements have been performed with X ray tube- and radioisotope-based energy dispersive X ray fluorescence spectrometers. Both liquid nitrogen- and thermo electrically-cooled silicon detectors were utilized in the analysis. Samples analysed include soil, water, plant material, and airborne particulate matter collected on filters. Depending on the technique and the investigated elements, the above-mentioned samples were analysed either directly or indirectly (after decomposing the sample in a mineralization process or/and chemical preconcentration procedure). The achieved detection limits for different techniques, established by measuring appropriate reference standards, are presented. The utilization of the micro-beam XRF technique for studying element distribution in heterogeneous samples and investigating the 3D- and 2D-morphology of minute samples by means of computerized X ray absorption and X ray fluorescence tomography is described. The different X ray techniques have their unique advantages. The micro-beam X ray fluorescence set-up has an advantage of producing very well collimated primary X ray beam (by means of X ray capillary optics the beam is collimated down to about 15 μm in diameter), in front of which the analysed sample can be precisely positioned, providing local information about the sample composition. TXRF technique has its leading edge in analysis of liquid samples, and as a reference method for a conventional bulk EDXRF analysis of heterogeneous materials such as air particulates collected on filter where the particle size effects can seriously influence the

  6. Particle Accelerator Applications: Ion and Electron Irradiation in Materials Science, Biology and Medicine

    Science.gov (United States)

    Rodríguez-Fernández, Luis

    2010-09-01

    Although the developments of particle accelerators are devoted to basic study of matter constituents, since the beginning these machines have been applied with different purposes in many areas also. Today particle accelerators are essential instruments for science and technology. This work presents an overview of the main application for direct particle irradiation with accelerator in material science, biology and medicine. They are used for material synthesis by ion implantation and charged particle irradiation; to make coatings and micromachining; to characterize broad kind of samples by ion beam analysis techniques; as mass spectrometers for atomic isotopes determination. In biomedicine the accelerators are applied for the study of effects by charged particles on cells. In medicine the radiotherapy by electron irradiation is widely used, while hadrontherapy is still under development. Also, they are necessary for short life radioisotopes production required in radiodiagnostic.

  7. Particle Accelerator Applications: Ion and Electron Irradiation in Materials Science, Biology and Medicine

    International Nuclear Information System (INIS)

    Although the developments of particle accelerators are devoted to basic study of matter constituents, since the beginning these machines have been applied with different purposes in many areas also. Today particle accelerators are essential instruments for science and technology. This work presents an overview of the main application for direct particle irradiation with accelerator in material science, biology and medicine. They are used for material synthesis by ion implantation and charged particle irradiation; to make coatings and micromachining; to characterize broad kind of samples by ion beam analysis techniques; as mass spectrometers for atomic isotopes determination. In biomedicine the accelerators are applied for the study of effects by charged particles on cells. In medicine the radiotherapy by electron irradiation is widely used, while hadrontherapy is still under development. Also, they are necessary for short life radioisotopes production required in radiodiagnostic.

  8. 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)

  9. 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. PMID:26982211

  10. Biological availability of energy related effluent material in the coastal ecosystem

    International Nuclear Information System (INIS)

    In order to make the predictions necessary to forecast the ecological consequences of an energy-related technology, there must be an understanding of: the biogeochemical processes involved in the natural system; the manner in which an energy technology affects these processes and how, in turn, this affects the ecosystem as a whole. Direct biological effects such as lethality, behavioral changes, and physiological changes, are being studied under the program previously discussed. The biological availability and impact studies are investigating: the chemical, physical, and biological processes that occur in the natural marine ecosystem; how energy effluents affect these processes; and the factors involved in regulating the bioavailability of effluent material. This past year's effort has centered on defining the quantities and forms of metals and radioisotopes in nuclear power plant effluent streams, the chemical forms present in bioassay systems, the chemical and microbial processes controlling the forms of metals available from the sediments, and the uptake and control of copper in shrimp. In addition, several sites in Sequim Bay have been monitored for potential use in field verification studies

  11. New Method for Monitoring the Process of Freeze Drying of Biological Materials.

    Science.gov (United States)

    Alkeev, Nikolay; Averin, Stanislav; von Gratowski, Svetlana

    2015-12-01

    A capacitive sensor was proposed and tested for the monitoring and control of a freeze drying process of a vaccine against the Newcastle disease of birds. The residual moisture of the vaccine was measured by the thermogravimetric method. The vaccine activity was determined by titration in chicken embryos. It was shown that, at the stages of freezing and primary drying, a capacitive sensor measured the fraction of unfrozen liquid phase in a material and allowed one to control the sublimation stage of drying in an optimal way. This prevented the foaming of the material and shortened the total drying time approximately twice. The control range at the sublimation stage of drying expanded up to -70°C. It was found at the final stage of drying that the signal of a capacitive sensor passed through a maximum value. We supposed that this maximum corresponds to the minimum of intramolecular mobility of biological macromolecules and hence to the optimal residual moisture of the material, which ensures long-term preservation of its activity. We also suppose that using the capacitive sensor at the final stage of drying allows one to more precisely detect the time when the residual moisture of dried material reaches the optimal value. PMID:26022547

  12. Analytic determination of the activation of essential and toxic trace elements in biological material

    International Nuclear Information System (INIS)

    A neutron activation-analysis technique for the multielement determination in biological material was developed. The individual steps of this procedure comprise radiochemical and also instrumental analytic techniques. After radiochemical separation 34 elements can be determined, after only instrumental procedures 26 elements can be detected in biological material. The radiochemical analysis of 34 elements lasts 4 days. Tracer investigations on the radionuclide retention of the anorganic separators HAP, TiP and ZP in 9N aqueous HNO3 solution indicated that apart from Na-24, K-42 and P-32 the radionuclides Cs-134, Rb-86 and Se-75 are almost quantitatively adsorbed at the separators. For the remaining investigated radionuclides different but well-reproducible retention values resulted. The pH-value only slightly influences the extent of the radionuclide retention. Kinetic investigations on the radiochemical precipitation of some radionuclides on Cu and Cu(Hg)sub(x) were carried out. The depositing of the radionuclides Ag-110m, Hg-203 and Se-75 at 00C and room temperature on Cu(Hg)sub(x) and Cu foil is a first order reaction. The half-life periods and the velocity constants of the depositing on Cu and Cu(Hg)sub(x) were determined for the investigated radionuclides in dependency of the temperature. The technique was examined by means of international biological multielement standards of known element combinations. The realisation of ring tests for the multielement determination in potatoe and milk powder showed that this method provides precise results. The applicability of the radiochemical method was confirmed by the simultaneous determination of 25 elements in overall nutrition samples. The instrumental technique was applied for the multielement determination in human hair (of the head) and in river water. (orig./MG)

  13. Collaborative analysis for certification of zirconium and zirconium base alloy reference materials JAERI-Z11 to Z16

    International Nuclear Information System (INIS)

    The second Sub-Committee on Zircaloy Analysis was organized in April 1978, under the Committee on Analytical Chemistry on Nuclear Fuels and Reactor Materials, JAERI, for the renewal of zirconium and zirconium base alloy certified reference materials (CRMs). The Sub-Committee carried out collaborative analysis among 13 participating laboratories for the certification of the CRMs, JAERI-Z11 to Z18, after development, improvement and evaluation of analytical methods during the period of May 1978 to June 1982. As the result of the collaborative analysis, the certified value was given for 18 elements (Sn, Fe, Ni, Cr, B, Cd, U, Cu, Co, Mn, Pb, Al, Ti, Si, Mo, W, Hf, C) in the CRMs. The first part of this report includes general discussion, the second part principles of certification, the third part development and verification of analytical methods, and the fourth part evaluation of analytical results on 17 elements. Preparation of Z11 to Z18, and certification for carbon in JAERI-Z17 and Z18 were reported separately in JAERI-M 83-241 and M 83-035, respectively. (author)

  14. Comparative study of optimised BCR sequential extraction scheme and acid leaching of elements in the certified reference material NIST 2711

    International Nuclear Information System (INIS)

    The optimised BCR sequential extraction procedure and a 4 h 1 mol L-1 HCl partial extraction have been performed on the NIST 2711 reference material for a suite of 12 elements (Cd, Sb, Pb, Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, As) using magnetic sector ICP-MS. A pseudo-total aqua regia digest of NIST 2711 has also been undertaken for quality assurance purposes, and comparison of the sum of the four BCR fractions, which included an aqua regia digest on the residue, with the pseudo-total aqua regia digest has been used to assess the accuracy of the BCR partitioning approach. As a result of this work, discrepancies between previous studies about BCR partitioning of elements in NIST 2711 have been discussed and an increase in confidence about the use of BCR partitioning scheme on seven elements (Cd, Pb, Al, Mn, Fe, Cu, Zn) in this standard material has been obtained. On the other hand, BCR partitioning for Sb, Cr, Co, Ni and As has been provided for the first time. Partial extraction results are also reported for the same 12 elements analysed by the optimised BCR procedure, with the partial extraction results exhibiting a strong correlation with the sum of the three labile steps of the BCR procedure

  15. 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.

  16. Application of reference point indentation for micro-mechanical surface characterization of calcium silicate based dental materials.

    Science.gov (United States)

    Antonijević, Djordje; Milovanović, Petar; Riedel, Christoph; Hahn, Michael; Amling, Michael; Busse, Björn; Djurić, Marija

    2016-04-01

    The objective of this study was to elucidate micromechanical properties of Biodentine and two experimental calcium silicate cements (CSCs) using Reference Point Indentation (RPI). Biomechanical characteristics of the cement type and the effects of a radiopacifier, liquid components, acid etching treatment and bioactivation in simulated body fluid (SBF) were investigated by measuring the microhardness, average unloading slope (Avg US) and indentation distance increase (IDI). Biodentine had a greater microhardness than the experimental CSCs, while the Avg US and IDI values were not significantly different among investigated materials. There was a statistically significant difference in microhardness and IDI values between pure CSCs and radiopacified cements (p < 0.05). Micromechanical properties were not affected by different liquid components used. Acid-etching treatment reduced Biodentine's microhardness while cements' immersion in SBF resulted in greater microhardness and higher IDI values compared to the control group. Clearly, the physiological environment and the cements' composition affect their surface micromechanical properties. The addition of calcium chloride and CSCs' immersion in SBF are beneficial for CSCs' micromechanical performance, while the addition of radiopacifiers and acid etching treatment weaken the CSCs' surface. Application of RPI aids with the characterization of micromechanical properties of synthetic materials' surfaces. PMID:26888441

  17. 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

  18. 生物质电厂电气主接线的选择%Electrical Main Wiring Selection in Biological Material Power Plant

    Institute of Scientific and Technical Information of China (English)

    张彦昌; 石巍; 张超

    2012-01-01

    Due to the distribution and transportation cost limit in biological material power plant, the capacity is generally not too large, its internal electrical main wiring type is flexible and various. Introduction was made to the plan of the power plant connect-in system, the selection measures of generator voltage and high-voltage used by plant, and the setting principle of generator outlet circuit breakers. Two kinds of electrical main wiring in biological material power plant were compared and analyzed from the reliability and economy aspects, thus the optimized plan was obtained to provide reference for design and study in biological material power plant.%生物质发电厂容量由于受燃料分布及运输成本限制,容量一般不大,其内部电气主接线型式灵活多变。介绍了电厂接入系统的方案、发电机电压及高压厂用电压的选择措施,以及发电机出口断路器的设置原则。从可靠性和经济性两方面对生物质电厂的两种电气主接线进行对比分析,进而得出优选方案,供生物质电厂设计与研究参考。

  19. Carbon Stable Isotope Analysis of Methylmercury Toxin in Biological Materials by Gas Chromatography Isotope Ratio Mass Spectrometry.

    Science.gov (United States)

    Masbou, Jeremy; Point, David; Guillou, Gaël; Sonke, Jeroen E; Lebreton, Benoit; Richard, Pierre

    2015-12-01

    A critical component of the biogeochemical cycle of mercury (Hg) is the transformation of inorganic Hg to neurotoxic monomethylmercury (CH3Hg). Humans are exposed to CH3Hg by consuming marine fish, yet the origin of CH3Hg in fish is a topic of debate. The carbon stable isotopic composition (δ(13)C) embedded in the methyl group of CH3Hg remains unexplored. This new isotopic information at the molecular level is thought to represent a new proxy to trace the carbon source at the origin of CH3Hg. Here, we present a compound-specific stable isotope analysis (CSIA) technique for the determination of the δ(13)C value of CH3Hg in biological samples by gas chromatography combustion isotope ratio mass spectrometry analysis (GC-C-IRMS). The method consists first of calibrating a CH3Hg standard solution for δ(13)C CSIA. This was achieved by comparing three independent approaches consisting of the derivatization and halogenation of the CH3Hg standard solution. The determination of δ(13)C(CH3Hg) values on natural biological samples was performed by combining a CH3Hg selective extraction, purification, and halogenation followed by GC-C-IRMS analysis. Reference δ(13)C values were established for a tuna fish certified material (ERM-CE464) originating from the Adriatic Sea (δ(13)C(CH3Hg) = -22.1 ± 1.5‰, ± 2 SD). This value is similar to the δ(13)C value of marine algal-derived particulate organic carbon (δ(13)CPOC = -21‰).

  20. 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