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Sample records for activation analysis method

  1. Analysis of Precision of Activation Analysis Method

    Heydorn, Kaj; Nørgaard, K.

    1973-01-01

    The precision of an activation-analysis method prescribes the estimation of the precision of a single analytical result. The adequacy of these estimates to account for the observed variation between duplicate results from the analysis of different samples and materials, is tested by the statistic T...

  2. Computer modeling for neutron activation analysis methods

    Full text: The INP AS RU develops databases for the neutron-activation analysis - ND INAA [1] and ELEMENT [2]. Based on these databases, the automated complex is under construction aimed at modeling of methods for natural and technogenic materials analysis. It is well known, that there is a variety of analysis objects with wide spectra, different composition and concentration of elements, which makes it impossible to develop universal methods applicable for every analytical research. The modelling is based on algorithm, that counts the period of time in which the sample was irradiated in nuclear reactor, providing the sample's total absorption and activity analytical peaks areas with given errors. The analytical complex was tested for low-elemental analysis (determination of Fe and Zn in vegetation samples, and Cu, Ag and Au - in technological objects). At present, the complex is applied for multielemental analysis of sediment samples. In this work, modern achievements in the analytical chemistry (measurement facilities, high-resolution detectors, IAEA and IUPAC databases) and information technology applications (Java software, database management systems (DBMS), internet technologies) are applied. Reference: 1. Tillaev T., Umaraliev A., Gurvich L.G., Yuldasheva K., Kadirova J. Specialized database for instrumental neutron activation analysis - ND INAA 1.0, The 3-rd Eurasian Conference Nuclear Science and its applications, 2004, pp.270-271.; 2. Gurvich L.G., Tillaev T., Umaraliev A. The Information-analytical database on the element contents of natural objects. The 4-th International Conference Modern problems of Nuclear Physics, Samarkand, 2003, p.337. (authors)

  3. Instrumental neutron activation analysis - a routine method

    This thesis describes the way in which at IRI instrumental neutron activation analysis (INAA) has been developed into an automated system for routine analysis. The basis of this work are 20 publications describing the development of INAA since 1968. (Auth.)

  4. The monostandard method in thermal neutron activation analysis

    A simple method is described for instrumental multielement thermal neutron activation analysis using a monostandard. For geological and air dust samples, iron is used as a comparator, while sodium has advantages for biological materials. To test the capabilities of this method, the values of the effective cross sections of the 23 elements determined were evaluated in a reactor site with an almost pure thermal neutron flux of about 9 x 1012 n x cm-2 x sec-1 and an epithermal neutron contribution of less than 0,03%. The obtained values were found to agree mostly well with the literature best values of thermal neutron cross sections. The results of an analysis by activation in the same site agree well with the relative method using multielement standard and for several standard reference materials with certified element contents. A comparison of the element contents obtained by the monostandard and relative methods together with corresponding precisions and accuracies is given. A brief survey of the monostandard method is presented. (orig.)

  5. Analysis of medicinal plant extracts by neutron activation method

    This dissertation has presented the results from analysis of medicinal plant extracts using neutron activation method. Instrumental neutron activation analysis was applied to the determination of the elements Al, Br, Ca, Ce, Cl, Cr, Cs, Fe, K, La, Mg, Mn, Na, Rb, Sb, Sc and Zn in medicinal extracts obtained from Achyrolcline satureoides DC, Casearia sylvestris, Centella asiatica, Citrus aurantium L., Solano lycocarpum, Solidago microglossa, Stryphnondedron barbatiman and Zingiber officinale R. plants. The elements Hg and Se were determined using radiochemical separation by means of retention of Se in HMD inorganic exchanger and solvent extraction of Hg by bismuth diethyl-dithiocarbamate solution. Precision and accuracy of the results have been evaluated by analysing reference materials. The therapeutic action of some elements found in plant extracts analyzed was briefly discussed

  6. High precision methods of neutron activation analysis applied to geochemistry

    Neutron activation analysis is a technique for measuring abundances of chemical elements, which differs from other methods in that it is based upon nuclear reactions instead of chemistry. This characteristic has special relevance for geochemistry because of its inherent sensitivity for trace elements which cannot be reached by other methods. 99% of the earth's crust is made up of just 8 elements, whereas the remaining 1% must accommodate 70-odd rock building trace elements of which about half can be measured by neutron activation analysis. In recent years, there has been much interest in these trace elements because they encompass diverse chemical properties. The present discussion of the technique is based upon more than 15 years of experience at the Lawrence Berkeley Laboratory and The Hebrew University of Jerusalem. This is not meant to intimate that the practices in other laboratories do not merit attention. Perhaps our approach differs from other published work in the emphasis given to sources of error and learning how to control them

  7. Tool for automated method design in activation analysis

    A computational approach to the optimization of the adjustable parameters of nuclear activation analysis has been developed for use in comprehensive method design calculations. An estimate of sample composition is used to predict the gamma-ray spectra to be expected for given sets of values of experimental parameters. These spectra are used to evaluate responses such as detection limits and measurement precision for application to optimization by the simplex method. This technique has been successfully implemented for the simultaneous determination of sample size and irradiation, decay and counting times by the optimization of either detection limit or precision. Both single-element and multielement determinations can be designed with the aid of these calculations. The combination of advance prediction and simplex optimization is both flexible and efficient and produces numerical results suitable for use in further computations

  8. Neutron activation analysis: A primary method of measurement

    Greenberg, Robert R.; Bode, Peter; De Nadai Fernandes, Elisabete A.

    2011-03-01

    Neutron activation analysis (NAA), based on the comparator method, has the potential to fulfill the requirements of a primary ratio method as defined in 1998 by the Comité Consultatif pour la Quantité de Matière — Métrologie en Chimie (CCQM, Consultative Committee on Amount of Substance — Metrology in Chemistry). This thesis is evidenced in this paper in three chapters by: demonstration that the method is fully physically and chemically understood; that a measurement equation can be written down in which the values of all parameters have dimensions in SI units and thus having the potential for metrological traceability to these units; that all contributions to uncertainty of measurement can be quantitatively evaluated, underpinning the metrological traceability; and that the performance of NAA in CCQM key-comparisons of trace elements in complex matrices between 2000 and 2007 is similar to the performance of Isotope Dilution Mass Spectrometry (IDMS), which had been formerly designated by the CCQM as a primary ratio method.

  9. Structural Analysis Extended with Active Fault Isolation - Methods and Algorithms

    Gelso, Esteban R.; Blanke, Mogens

    2009-01-01

    Isolability of faults is a key issue in fault diagnosis whether the aim is maintenance or active fault-tolerant control. It is often encountered that while faults are detectable, they are only group-wise isolable from a usual diagnostic point of view. However, active injection of test signals on...... system inputs can considerably enhance fault isolability. This paper investigates this possibility of active fault isolation from a structural point of view. While such extension of the structural analysis approach was suggested earlier, algorithms and case studies were needed to explore this theory. The...

  10. Conventional radiometric methods of analysis including neutron activation

    The chapter aims primarily to provide a reference with which the various mass spectrometric methods may be compared. The fundamental problems created by low specific activity in the measurement of very long-lived radionuclides using radiometric techniques are noted and discussed in terms of the different types of decay, background count rates, source weight and spectral interferences. An attempt is made to identify typical detection limits for the radiometric determination of the various long-lived radionuclides. The use of neutron activation as a means of enhancing sensitivity or convenience of measurement for long-lived radionuclides is described with appropriate illustrations. Mass spectrometry and radiometry are seen as complementary, not competitive techniques for the measurement of radioactive materials, each with its own advantages and disadvantages. (author). 21 refs, 2 figs, 6 tabs

  11. Tensor analysis methods for activity characterization in spatiotemporal data

    Haass, Michael Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Van Benthem, Mark Hilary [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ochoa, Edward M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-03-01

    Tensor (multiway array) factorization and decomposition offers unique advantages for activity characterization in spatio-temporal datasets because these methods are compatible with sparse matrices and maintain multiway structure that is otherwise lost in collapsing for regular matrix factorization. This report describes our research as part of the PANTHER LDRD Grand Challenge to develop a foundational basis of mathematical techniques and visualizations that enable unsophisticated users (e.g. users who are not steeped in the mathematical details of matrix algebra and mulitway computations) to discover hidden patterns in large spatiotemporal data sets.

  12. Multichannel analysis of surface waves (MASW) - Active and passive methods

    Park, C.B.; Miller, R.D.; Xia, J.; Ivanov, J.

    2007-01-01

    The conventional seismic approaches for near-surface investigation have usually been either high-resolution reflection or refraction surveys that deal with a depth range of a few tens to hundreds meters. Seismic signals from these surveys consist of wavelets with frequencies higher than 50 Hz. The multichannel analysis of surface waves (MASW) method deals with surface waves in the lower frequencies (e.g., 1-30 Hz) and uses a much shallower depth range of investigation (e.g., a few to a few tens of meters). ?? 2007 Society of Exploration Geophysicists.

  13. Establishment and application of the cyclic neutron activation analysis method on mini-reactor

    Background: Instrument neutron activation analysis is a nondestructive analytic method. Some elements after irradiation produce short half-life radio-nuclides (<60 s), and others produce both long-lived and short-lived nuclides. For these short-lived nuclides, the single measurement has big error. Purpose: In order to reduce the error, cyclic neutron activation analysis can be used to improve the sensitivity. Methods: A device was designed to be connected to the sample transporter, detector and irradiation pipeline in the reactor, which can automatically control the irradiation time and counting time. According to the nuclear parameters of certain elements, irradiation time and counting time and cycle times were determined by experiment. Cyclic activation analysis method was established at the mini-reactor. Results: This paper studied cyclic activation analysis conditions of 17 kinds of element, and applied to the determination of actual samples. Cyclic epithermal neutron activation analysis (CENAA) method was discussed too. By the analysis of national standard reference materials, the reliability of this method was confirmed. Conclusion: Cyclic neutron activation analysis (CNAA) is an effective analytic method for only short life nuclide elements. For both short and long lived nuclides of elements, the cyclic activation analysis method can make the analytical cycle shorten, from a few days or several weeks to within a few minutes. Cyclic activation analysis has the advantages of high sensitivity, and its precision and accuracy are better than single short irradiation activation analysis. (authors)

  14. Study on the methods for analysis of the chemical poison in canister by neutron activity

    The method that is used to analyse the poison gases in canister by neutron activity is proposed. Through theory analysis and experimental measurement, the feasibility for analysis of the poison gases in a canister by neutron activity has been demonstrated, and it is proved that the method itself do not result in radioactive problem to use again the canister. (authors)

  15. A simple and fast method for the determination of active ingredient in antiperspirant cosmetics by neutron activation analysis

    Antiperspirant cosmetics are tested for their active ingredient (aluminium chlorohydroxide) by conventional analytical techniques. Aluminium has been determined by instrumental neutron activation analysis in all antiperspirant products and package forms available in the Greek market in order to develop a simple and fast method for quantization. The results show that neutron activation analysis could be established as an official method for the determination of active ingredient in antiperspirant cosmetics. The proposed method is compared with the existing official methods and an alternative sampling method for aerosol package is presented. (author)

  16. Possibilities of Controlling Nutritious Wheat Flour by the Method of Neutron Activation Analysis

    Possibilities of controlling nutritious wheat flour by the method of neutron activation analysis are studied. It is established, that detection of contents of As, Cd, Hg, Cu and Zn in wheat flour is possible using this method and a neutron multiplier. The results of measurements were worked out by polycomparative method. (author)

  17. Evaluation of precision and accuracy of neutron activation analysis method of environmental samples analysis

    Evaluation of precision and accuracy of Neutron Activation Analysis (NAA) method used by P2TRR performed by analyzed the standard reference samples from the National Institute of Environmental Study of Japan (NIES-CRM No.10 (rice flour) and the National Bureau of USA (NBS-SRM 1573a (tomato leave) by NAA method. In analyze the environmental SRM No.10 by NAA method in qualitatively could identified multi elements of contents, namely: Br, Ca, Co, CI, Cs, Gd, I, K< La, Mg, Mn, Na, Pa, Sb, Sm, Sr, Ta, Th, and Zn (19 elements) for SRM 1573a; As, Br, Cr, CI, Ce, Co, Cs, Fe, Ga, Hg, K, Mn, Mg, Mo, Na, Ni, Pb, Rb, Sr, Se, Sc, Sb, Ti, and Zn, (25 elements) for CRM No.10a; Ag, As, Br, Cr, CI, Ce, Cd, Co, Cs, Eu, Fe, Ga, Hg, K, Mg, Mn, Mo, Na, Nb, Pb, Rb, Sb, Sc, Th, TI, and Zn, (26 elements) for CRM No. 10b; As, Br, Co, CI, Ce, Cd, Ga, Hg, K, Mn, Mg, Mo, Na, Nb, Pb, Rb, Sb, Se, TI, and Zn (20 elementary) for CRM No.10c. In the quantitatively analysis could determined only some element of sample contents, namely: As, Co, Cd, Mo, Mn, and Zn. From the result compared with NIES or NBS values attained with deviation of 3% ∼ 15%. Overall, the result shown that the method and facilities have a good capability, but the irradiation facility and the software of spectrometry gamma ray necessary to developing or seriously research perform

  18. Analysis of sediment samples by reactor neutron activation analysis using Ko method

    The study on the determination of elemental concentration in sediments from lakes and other water bodies is of prime importance for geological as well as environmental studies. The profile of different elements with prior knowledge of sedimentation rates might provide clues to knowledge of their possible origin. The results on the determination of elemental concentration in sediments from Nanital lake at different depths are presented using single comparator neutron activation analysis (KoNAA) method. Irradiations of samples along with gold as comparator were carried out in Apsara reactor at Bhabha Atomic Research Centre. The concentrations of Na, K, Mn, Cu, Ba, As, Sr, Sc, La, Sm, Eu and Dy were determined. Variations in concentration of different elements in the sediment samples as a function of depth and the derived correlations are presented in this paper. (author). 5 refs., 1 fig., 1 tab

  19. Instrumental neutron-activation analysis of geological samples for rare earths using internal standard method

    Full text: Instrumental neutron-activation analysis os one of a few modern analytical techniques, being applied to solve difficult analytical tasks, such as mineral resources analysis for rare earth element content. No other analytical technique can be used with the latter end in view, since Instrumental neutron-activation analysis is possessed of the highest precision among them. In order to check experimentally the stated approach to REE content calculation by the internal standard method, relative bias values of this approach should be estimated. This approach will be verified further with a number of different rock samples simultaneously analyzed by an instrumental neutron-activation analysis certified analytical technique

  20. Automatization of the neutron activation analysis method in the nuclear analysis laboratory

    In the present paper the work done to automatice the Neutron Activation Analysis technic with a neutron generator is described. An interface between an IBM compatible microcomputer and the equipment in use to make this kind of measurement was developed. including the specialized software for this system

  1. Comparative study of destructive and non-destructive methods in the activation analysis of rocks

    A comparative study between non-destructive thermal neutron activation analysis and activation analysis with radiochemical group separation is made Both methods are applied to the determination of trace elements minor and major elements in rocks. The treatment of the rocks, with special reference to the problems related to grinding and contamination by foreign elements is described. The choice of standards for multielement trace activation analysis is discussed. Two types of computer programs for the evalution of data obtained through Ge-li detector counting are used. All the phases of the destructive and non destructive analysis are described. In the destructive analysis, an adaptation of the group separation scheme developed by Morrison et al for the activation analysis of geological samples is made. The changes introduced make the radiochemical separation simpler and more rapid. Both destructive and non destructive methods are tested by means of the analysis of the United States Geological Survey standard rock AGV-1, which has been analysed by many authors. The same procedure is then applied to some alcaline rocks taken from the apatite mine of Jacupiranga, in the State of Sao Paulo, Brazil. The knowledge of the trace element concentration in these rocks is important for geochemical studies. A detailed study of the possible interferences encountered in the neutron activation analysis of these rocks is made, considering the interferences due to major activities, and to the proximity of the several gamma ray energies of the radioisotopes produced. Finally, the comparative study between the two methods is presented, using statistical tests for the quantitative evalution of results. (Author)

  2. Neutron activation analysis of trace elements in carbonate rocks by using a ko standardization method

    The quantitative analysis of the trace element was conducted by the ko method using carbonate rock standard sample JLs-1 (limestone) and JDo-1 (Dolomite), and the effectiveness of the activation analysis with the ko method to the carbonate rock sample was confirmed. The accuracy of the quantitative measurement for the analysis results of long-lived nuclides of Al and Ba, middle-lived nuclides of Sm and Ho, and short-lived nuclides of Ce and Yb was evaluated compared with recommended values of Geological Survey of Japan. (H. Katsuta)

  3. Principles and methods of neutron activation analysis (NAA) in improved water resources development

    The methods of neutron activation analysis (NAA) as it applies to water resources exploration, exploitation and management has been reviewed and its capabilities demonstrated. NAA has been found to be superior and offer higher sensitivity to many other analytical techniques in analysis of water. The implications of chemical and element concentrations (water pollution and quality) determined in water on environmental impact assessment to aquatic life and human health are briefly highlighted

  4. Application of active neutronic interrogation method to the line analysis in reprocessing plant

    In a reprocessing plant of irradiated spent fuels, the knowledge in real time (line analysis) of uranium and plutonium quantities present in solutions is an extremely important parameter to control the proceeding and for the apparatus safety. The active neutronic analysis give a nondestructive non intrusive and quick measure to know the concentrations. This method consists in inducing fissions in nuclides with a neutron source and then to detect the particles which come from

  5. Multi elementary analysis in medicinal plants through the neutron activation method

    A instrumental method by neutron activation in multielementary analysis was applied. Samples of Centelha asiatica (Cairucu) and Paulinia cupana (Guarana) were used. The elements Al, Br, Ca, Cl, Fe, K, Mn, Na, Rb, Sc, and Zn were determined. The results like precision and exactitude were analysed. (L.M.J.)

  6. Activation analysis

    The neutron activation analysis, which appears to be in limits for further advance, is the most suitable for providing information on the principal as well as the microcomponents in any sample of solid form. Then, instrumental activation analysis is capable of determination of far many elements in various samples. Principally on the neutron activation analysis, the following are described in literature survey from 1982 to middle 1984: bibliography, review, data collection, etc.; problems in spectral analysis and measurement; activation analysis with neutrons; charged particle and photo-nucleus reactions; chemical separation, isotopic dilution activation analysis; molecular activation analysis; standard materials; life and its relation samples; environmental, food, court trial and archaeological samples; space and earth sciences. (Mori, K.)

  7. Large sample activation analysis. Monitoring of photovoltaic module recycling using radioanalytical methods

    Photovoltaic modules are the most promising sources of renewable energy. According to respective EU Directives both the glass carrier material and the photo-active layer (CdTe in this study) shall be re-used. Analyses for process surveillance and control have to be carried out, primarily for monitoring of the separation efficiency and the enrichment level of CdTe. For on-site measurement and process control energy-dispersive X-ray fluorescence spectrometry was used. Instrumental photon activation analysis using an electron linear accelerator as activating bremsstrahlung source is intended to be used later for iterative intermediate analysis of random samples for quality control. In this work, the feasibility of both methods for this task was studied. (author)

  8. Performance Analysis of Transfer function Based Active Noise Cancellation Method Using Evolutionary Algorithm

    Prof. Vikas Gupta

    2014-01-01

    Full Text Available Due to the exponential increase of noise pollution, the demand for noise controlling system is also increases. Basically two types of techniques are used for noise cancellation active and passive. But passive techniques are inactive for low frequency noise, hence there is an increasing demand of research and developmental work on active noise cancellation techniques. In this paper we introduce a new method in the active noise cancellation system. This new method is the transfer function based method which used Genetic and Particle swarm optimization (PSO algorithm for noise cancellation. This method is very simple and efficient for low frequency noise cancellation. Here we analysis the performance of this method in the presence of white Gaussian noise and compare the results of Particle swarm optimization (PSO and Genetic algorithm. Both algorithms are suitable for different environment, so we observe their performance in different fields. In this paper a comparative study of Genetic and Particle swarm optimization (PSO is described with proper results. It will go in depth what exactly transfer function method, how it work and advantages over neural network based method

  9. A method of neutron activation analysis to determine the concentration of alloy elements in steels

    The determination of the concentration of V, Mn and W in several types of steels was carried out through neutron activation analysis with an isotopic neutron source. Induced activities were detected with a NaI(Tl) gamma spectrometer coupled to a single channel pulse height analyser. Highly significant correlations have been found between specific count rates for each radionuclide and the concentration of the corresponding element (r > = .999 for each element); concentration ranges comprised a number of steel types. The comparison between the results of the application of the method and the ones obtained through conventional chemical analyses showed discrepancies no higher than 10%. (Author)

  10. Analysis of ancient coins by activation with rapid neutrons and by PIXE method

    The quantitative analysis of valuable objects in archaelogical research calls for the use of strictly non-destructive methods, even on very small surfaces of the object to investigate. The analytical method used by L.A.R.N. for the determination of principal elements Cu, Sn and Pb and of trace elements As and Ag in coins have been: 1. the rapid neutron activation (14 Mev) for the analysis of Sn; 2. the PIXE (Proton-Induced X-ray Emission) technique for the surface and core measures in samples which have been sawn as Sn, Pb, Ag and As. These methods have been used to analyse the blanks of Argos supplied by the Institut d'Archeologie of the University of Louvain. (A.F.)

  11. [Activity and cost analysis in surgical pathology. Experience of a French university laboratory using the activity-based costing method].

    Bellocq, J P; Biron, N; Kessler, S; Penaud, M; Faujour, V; Ospel, J; Supper, E; Barthel, A; Roussel, J F; Méchine-Neuville, A; Marcellin, L; Lang-Avérous, G; Chenard, M P

    2001-06-01

    Good self-knowledge enables us to have a well- reasoned adaptation to our environment. Starting from this precept based on simple common sense, activity and cost analysis, when applied to medical departments in a university hospital setting, represents a necessary phase in their scientific progression and in the continuation of their university vocation. This is all the more true given the present climate of economic and organizational restructuring of medical facilities. This paper relates the experience of a French surgical pathology department which was assessed for cost effectiveness using the Activity-Based Costing (ABC) method in 1999. This method, which originated in the business world and of which the general concepts are presented here, has given us a keener understanding of the diverse processes involved, their costs and how these costs are arrived at. Moreover, this method has identified the proportion of costs imputable to diagnostic work and of those linked to work specific to a university hospital, in particular teaching and research and development. The results can then be used for a clearer analysis of the figures required by prescribers and health care funding agencies, and, within the department, to enhance perception of work carried out by the entire staff in order to initiate a new type of management centered on activity (Activity-Based Management). Adaptable to any medical department, whatever its organizational structure, independent of the significance of any given code letter and regardless of the rating method used to grade activities, the ABC method also allows for comparisons between structures of a similar nature. The thoughts it inspires on economic performance must take into account the rules of good medical practice, the imperatives of quality assurance, the need for "breathing space" which are indispensable to research and a humanist conception of working relations. PMID:11468559

  12. The advanced 3D method for activation analysis of fusion reactor materials

    The method allows analyzing the complex objects activated by neutrons (e.g. fusion reactors) combining advantages of the 3D radiation transport by MCNP program with calculations of multiple activation and radioactive decay chains by FISPACT program. The problem of preparing the gamma-ray sources in cells of 3D geometry was solved by creation of an interface between the MCNP and FISPACT programs. The interface allows optimizing the process of activation analysis by revealing dominant sources of radiation. The developed interface essentially reduces the time needed for calculations. The main advantage of the method is realization of so-called 'multibox' procedure for decay gamma source sampling during decay gamma transport in very large and complex fusion reactor models. Shutdown dose rate calculations are faster (up to 600 times in ITER cryostat) in comparison with applied MCNP standard source definition by using an external user-supplied source subroutine of the 'multibox' procedure. The offered method is intended for solution of the activation tasks with deep penetration of radiation. The method was used in the engineering design of ITER-FEAT and RF DEMO-S

  13. a Three-Step Spatial-Temporal Clustering Method for Human Activity Pattern Analysis

    Huang, W.; Li, S.; Xu, S.

    2016-06-01

    How people move in cities and what they do in various locations at different times form human activity patterns. Human activity pattern plays a key role in in urban planning, traffic forecasting, public health and safety, emergency response, friend recommendation, and so on. Therefore, scholars from different fields, such as social science, geography, transportation, physics and computer science, have made great efforts in modelling and analysing human activity patterns or human mobility patterns. One of the essential tasks in such studies is to find the locations or places where individuals stay to perform some kind of activities before further activity pattern analysis. In the era of Big Data, the emerging of social media along with wearable devices enables human activity data to be collected more easily and efficiently. Furthermore, the dimension of the accessible human activity data has been extended from two to three (space or space-time) to four dimensions (space, time and semantics). More specifically, not only a location and time that people stay and spend are collected, but also what people "say" for in a location at a time can be obtained. The characteristics of these datasets shed new light on the analysis of human mobility, where some of new methodologies should be accordingly developed to handle them. Traditional methods such as neural networks, statistics and clustering have been applied to study human activity patterns using geosocial media data. Among them, clustering methods have been widely used to analyse spatiotemporal patterns. However, to our best knowledge, few of clustering algorithms are specifically developed for handling the datasets that contain spatial, temporal and semantic aspects all together. In this work, we propose a three-step human activity clustering method based on space, time and semantics to fill this gap. One-year Twitter data, posted in Toronto, Canada, is used to test the clustering-based method. The results show that the

  14. Charged Particle Activation Analysis as a Novel Method for Nuclear Metrology

    Accelerator based nuclear method of charged particle activation analysis has been used in order to analyse Australian environmental samples. Atmospheric particulates collected, around East Coast Australian cities and Port Moresby, just before and after the French Atomic Test Series of 1974 in the Pacific have been analyzed by proton activation analysis. A number of elements, namely S, Ca, Ti, Cr, Fe, Ni, Cu, Zn, Se and Hg, ranging in concentrations from .001 g/m3 to up to 3.27 g/m3 have been detected. The changes observed in the concentrations of these elements in the two sets of samples, taken just before and just after the Atomic Tests, are attributed to synoptic rather than nuclear Fall-Outeffects.

  15. Argon activation analysis, application to dating by the potassium-argon method

    Activation analysis using radiogenic argon-40 has been applied to rock-dating by the K-Ar method. The argon is extracted from the sample, purified, activated to saturation in a flux of 2 X 1013 neutrons/cm2 sec-1 and measured by gamma spectroscopy. The sensitivity obtained is such that it is possible to measure amounts of argon corresponding to age of a few thousand years only. However since it has not been possible to measure the amount of pollution of radiogenic argon by atmospheric argon with any accuracy, the measurable age limit is in fact of the order of MY. The method has been applied to basalts from the Mont-Dore region. The results obtained are in fairly good agreement with geological, stratigraphic and paleomagnetic data. (author)

  16. Evaluation of radiochemical neutron activation analysis methods for determination of arsenic in biological materials.

    Paul, Rick L

    2011-01-01

    Radiochemical neutron activation analysis (RNAA) with retention on hydrated manganese dioxide (HMD) has played a key role in the certification of As in biological materials at NIST. Although this method provides very high and reproducible yields and detection limits at low microgram/kilogram levels, counting geometry uncertainties may arise from unequal distribution of As in the HMD, and arsenic detection limits may not be optimal due to significant retention of other elements. An alternate RNAA procedure with separation of arsenic by solvent extraction has been investigated. After digestion of samples in nitric and perchloric acids, As(III) is extracted from 2 M sulfuric acid solution into a solution of zinc diethyldithiocarbamate in chloroform. Counting of (76)As allows quantitation of arsenic. Addition of an (77)As tracer solution prior to dissolution allows correction for chemical yield and counting geometries, further improving reproducibility. The HMD and solvent extraction procedures for arsenic were compared through analysis of SRMs 1577c (bovine liver), 1547 (peach leaves), and 1575a (pine needles). Both methods gave As results in agreement with certified values with comparable reproducibility. However, the solvent extraction method yields a factor of 3 improvement in detection limits and is less time-consuming than the HMD method. The new method shows great promise for use in As certification in reference materials. PMID:21133431

  17. Instrumental photon activation analysis of coal fly ashes using the internal standard method coupled with the standard addition method

    Multielement determinations of coal fly ashes (NIST SRM-1633a and BCR CRM-38) have been carried out by instrumental photon activation analysis using 30 MeV bremsstrahlung and the internal standard method coupled with the standard addition method. In these determinations, some major and minor constituent elements in the samples were properly used as effective internal standards. As a result, it was demonstrated that concentrations of 18 elements were determined accurately and precisely. Furthermore, a similar multielement determination has also been examined using 20 MeV bremsstrahlung. In this case, it was proved that better results can be achieved, because all interfering reactions were eliminated completely. (author) 14 refs.; 5 tabs

  18. The method of Sample Management in Neutron Activation Analysis Laboratory-Serpong

    In the testing laboratory used by neutron activation analysis method, sample preparation is the main factor and it can't be neglect. The error in the sample preparation can give result with lower accuracy. In this article is explained the scheme of sample preparation i.e sample receive administration, the separate of sample, fluid and solid sample preparation, sample grouping, irradiation, sample counting and holding the sample post irradiation. If the management of samples were good application based on Standard Operation Procedure, therefore each samples has good traceability. To optimize the management of samples is needed the trained and skilled personal and good facility. (author)

  19. Determination Of Heavy Metal Elements In The Environmental Samples Using Neutron Activation Analysis Method

    The environmental samples (water, soil and spinach) were analyzed using analysis activation neutron method. The aim of this research is to determine the heavy metal's pollution level in comparation with environmental standard. Samples were taken from 3 different locations, Kelurahan Papanggo, Kelurahan Sunter Agung, and Kelurahan Sunter Jaya. The samples were irradiated in the RSG-GAS's rabbit system. Samples irradiated were then measured by a gamma spectrometer. The result showed that environmental samples contained toxical heavy metal elements: Cr and As; moderate: Mn, V, and Co; and less toxical: Fe and Zn. The concentration of Cr, Co, and Zn in the soil, water and spinach samples were less than environmental standards applied

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

    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

  1. Present and future prospects for neutron activation analysis compared to other methods available

    The evolution of analysis by Neutron Activation during the last fifty years is briefly described. The reasons for its persistent success, in spite of more recent methods are examined. These reasons are based on the specific advantages of neutron irradiation: neutron penetration into the material, sensitive detection of 60 elements, selectivity and reliability. Furthermore the sensitivity is inversely proportional to the natural abundance of the element (for A>80). However to benefit fully from the advantages of N.A.A., it is essential to study the potential sources of error inherent in each step of the analysis (sampling, preparation, calibration, irradiation, chemical separation, radioactive measurement, calculation and interpretation of the results). These risks are discussed and examples given. The principal areas in which the N.A.A. is being used more and more are ultra-traces analysis, studies on the multivariant correlation between elements and the validation of other methods. Based on present applications and the likely progress of this technique, its future prospects are discussed. (author). 30 refs, 2 figs, 8 tabs

  2. Study of covariances involved in the k0 method of neutron activation analysis

    This work aimed the development of a methodology for the treatment of uncertainty in the k0 Method for Neutron Activation Analysis (NAA), comprehensively and accurately, by applying the covariance analysis methodology. All parameters involved in determining the concentration of a given element were analyzed with criteria in order to establish the correlations among them. Also established were the possible correlations between the concentrations of different elements for the same sample and for different samples. This procedure generated a large number of correlations that have been rigorously addressed. Data for analysis were obtained experimentally by means of irradiations performed at 24A irradiation position, near the core of the IEA-R1 research reactor, located at IPEN-CNEN/SP. The parameters α and f, characterizing the neutron field were determined by applying several methods from the literature. A detailed statistical treatment was applied to each measurement, verifying the various uncertainties and partial correlations. In order to deepen the study, targets of 64Zn and 68Zn were chosen, for which the nuclear parameters k0 and Q0 showed discrepancies in the literature in order to determine them experimentally. For 64Zn, the values for these parameters resulted 5.63(8) x 10-3 and 1.69(6), respectively. For 68Zn they resulted 4.00(6) x 10-4 and 2.34(4), respectively. These values were compared with data from the literature. The Monte Carlo method was applied at various stages of study, to allow accurate determination of some parameters needed for the complete data analysis. (author)

  3. Multielement analysis of human hair and kidney stones by instrumental neutron activation analysis with the k0-standardization method

    This paper focuses on the evaluation of the k0 method of instrumental neutron activation analysis in biological materials. The method has been applied in multielement analysis of human hair standard reference materials from IAEA, No. 085, No. 086 and from NIES (National Institute for Environmental Sciences) No. 5. Hair samples from people resident in different parts of Malaysia, in addition to a sample from Japan, were analyzed. In addition, human kidney stones from members of the Malaysian population have been analyzed for minor and trace elements. More than 25 elements have been determined. The samples were irradiated in the rotary rack (Lazy Susan) at the TRIGA Mark II reactor of the Malaysian Institute for Nuclear Technology and Research (MINT). The accuracy of the method was ascertained by analysis of other reference materials, including 1573 tomato leaves and 1572 citrus leaves. In this method the deviation of the 1/E1+α epithermal neutron flux distribution from the 1/E law (P/T ratio) for true coincidence effects of the γ-ray cascade and the HPGe detector efficiency were determined and corrected for

  4. Multielement analysis of human hair and kidney stones by instrumental neutron activation analysis with the k0-standardization method.

    Abugassa, I; Sarmani, S B; Samat, S B

    1999-06-01

    This paper focuses on the evaluation of the k0 method of instrumental neutron activation analysis in biological materials. The method has been applied in multielement analysis of human hair standard reference materials from IAEA, No. 085, No. 086 and from NIES (National Institute for Environmental Sciences) No. 5. Hair samples from people resident in different parts of Malaysia, in addition to a sample from Japan, were analyzed. In addition, human kidney stones from members of the Malaysian population have been analyzed for minor and trace elements. More than 25 elements have been determined. The samples were irradiated in the rotary rack (Lazy Susan) at the TRIGA Mark II reactor of the Malaysian Institute for Nuclear Technology and Research (MINT). The accuracy of the method was ascertained by analysis of other reference materials, including 1573 tomato leaves and 1572 citrus leaves. In this method the deviation of the 1/E1+ alpha epithermal neutron flux distribution from the 1/E law (P/T ratio) for true coincidence effects of the gamma-ray cascade and the HPGe detector efficiency were determined and corrected for. PMID:10355102

  5. The use of the TRIGA Mark II reactor, Ljubljana, Yugoslavia in the k0 method of neutron activation analysis

    The k0 standardisation method is suitable for routine multi-element determinations in various materials by reactor neutron activation. A 21 - element synthetic standard for biological material was analysed in this work by neutron activation analysis and the results obtained, as well as our experience with the method itself, are discussed. (author)

  6. Prioritizing conservation activities using reserve site selection methods and population viability analysis.

    Newbold, Stephen C; Siikamäki, Juha

    2009-10-01

    In recent years a large literature on reserve site selection (RSS) has developed at the interface between ecology, operations research, and environmental economics. Reserve site selection models use numerical optimization techniques to select sites for a network of nature reserves for protecting biodiversity. In this paper, we develop a population viability analysis (PVA) model for salmon and incorporate it into an RSS framework for prioritizing conservation activities in upstream watersheds. We use spawner return data for three closely related salmon stocks in the upper Columbia River basin and estimates of the economic costs of watershed protection from NOAA to illustrate the framework. We compare the relative cost-effectiveness of five alternative watershed prioritization methods, based on various combinations of biological and economic information. Prioritization based on biological benefit-economic cost comparisons and accounting for spatial interdependencies among watersheds substantially outperforms other more heuristic methods. When using this best-performing prioritization method, spending 10% of the cost of protecting all upstream watersheds yields 79% of the biological benefits (increase in stock persistence) from protecting all watersheds, compared to between 20% and 64% for the alternative methods. We also find that prioritization based on either costs or benefits alone can lead to severe reductions in cost-effectiveness. PMID:19831069

  7. Application of the neutron activation analysis method to the multielemental determination of food samples

    The application of thermal neutron activation analysis method for determining elements presented at low concentration and level of traces in bread and dried milk samples, using non-destructive and chemical analyses, was studied. The non-destructive analyses were based on measurements of gamma spectrometry of samples and standards irradiated by thermal neutron flux on the order of 1012n cm-2s-1. The irradiation time varied from some minutes to 8 hours. The Na, Cl, Mn, Br, Fe, Zn, Rb, Sb, Cr and Sc elements in bread samples were determined. The Na, K, Cl, Ca, Mg, Br, Al, Zn, Rb, Sb and Cr elements in dried milk samples were determined. In destructive analysis, the 24Na radioisotope was separeted by retention on hydrated antimony pentoxide column from 8N HCL after digestion of organic matter. The bread was dissolved in HNO3 concentrated and 70% of HCLO4 and the dried milk was dissolved in HNO3 concentrated and H2O2. The 64Cu, 69mZn and 140La radioisotopes determined. The concentrations obtained for dried milk were compared with data obtained by other authors from different contries. Basic considerations on detection limit related to its application on the technique used in this work, were done. The detection limits and trace elements using the Currie and Girardi methods were determined. The accuracy of results obtained for trace element detection limits is discussed. (Author)

  8. Application of the neutron activation analysis method to the multielemental determination of food samples

    The thermal neutron activation analysis method was applied to the determination of elements present at low concentrations and trace levels in samples of bread and milk powder using non-destructive analyses were based on gamma ray spectrometric measurements of samples and standards irradiated for periods which varied from some minutes to eight hours in a thermal neutron flux of about 1012n cm-2s-1. The concentrations obtained for milk powder were compared with the data obtained by other autors from different contries. For the bread, that comparison was not possible, because data about trace analysis in bread samples were not found. Besides, the results obtained for the various brands of bread and milk by means of non destructive and destructive analyses were compared using Student's t criterion. Some basic considerations about 'Detection Limit' were done, mainly in relation to its application in the technique used in the present work. The detection and determination limits of the trace elements analysed by destructive and non destructive techniques in bread and milk powder samples were determined using the Currie and Girardi methods. The precision of the analyses and the results obtained for the detection limits of the analysed trace elements are discussed. (Author)

  9. Rapid estimation of compost enzymatic activity by spectral analysis method combined with machine learning.

    Chakraborty, Somsubhra; Das, Bhabani S; Ali, Md Nasim; Li, Bin; Sarathjith, M C; Majumdar, K; Ray, D P

    2014-03-01

    The aim of this study was to investigate the feasibility of using visible near-infrared (VisNIR) diffuse reflectance spectroscopy (DRS) as an easy, inexpensive, and rapid method to predict compost enzymatic activity, which traditionally measured by fluorescein diacetate hydrolysis (FDA-HR) assay. Compost samples representative of five different compost facilities were scanned by DRS, and the raw reflectance spectra were preprocessed using seven spectral transformations for predicting compost FDA-HR with six multivariate algorithms. Although principal component analysis for all spectral pretreatments satisfactorily identified the clusters by compost types, it could not separate different FDA contents. Furthermore, the artificial neural network multilayer perceptron (residual prediction deviation=3.2, validation r(2)=0.91 and RMSE=13.38 μg g(-1) h(-1)) outperformed other multivariate models to capture the highly non-linear relationships between compost enzymatic activity and VisNIR reflectance spectra after Savitzky-Golay first derivative pretreatment. This work demonstrates the efficiency of VisNIR DRS for predicting compost enzymatic as well as microbial activity. PMID:24398221

  10. Drawing up of a procedure for vanadium determination in mussels using the neutron activation analysis method

    This work establishes an adequate procedure for obtaining reliable results for determination of vanadium in mussels, leg by leg by the neutron activation analysis (NAA), viewing the posterior application on the bio monitoring the coastal pollution, particularly near the petroleum terminals.For the evaluation of result quality concerning to the quality of those results, the work analysed the reference material certification NIST SRM 1566b Oyster Tissue. The precision of the results were also analysed using repetitions of mussel samples collected at the coastal of northern Sao Paulo state, Brazil. The NAA procedure consisted of 200 mg of sample and a synthetic standard of vanadium during a period of 8 s and under a thermal neutron flux of 6.6 x 1012 n cm-2 s-1 at the pneumatic station 4 of the IEA-R1 nuclear reactor of IPEN-CNEN/SP. After a 3 min decay, the measurements of the gamma activities of the sample and the standard were done using a Ge hyper pure semi-conductor detector, connected to gamma ray multichannel analyser. The vanadium were determined by the measurement of the gamma activity of the 52V through the 1434.08 keV peak, and half-life time of 3.75 min. The concentration of V were calculated by the comparative method. The obtained results indicated the viability of the NAA procedure established for the determination of vanadium in mussels

  11. Determination of multielements by neutron activation analysis using a coincidence counting method

    When γ-rays are counted using γ-ray spectrometry for neutron activation analysis (NAA), the Compton continuum from high-energy γ-rays often interferes with the detection of nuclides with lower energy γ-rays. A coincidence counting of γ-rays in the cascade series with a coaxial Ge detector and a well-type NaI(Tl) detector can reduce this problem. The coincidence counting method was applied to the determination of Se, Hf, Ba, Cs, Co, Sb and Sc in 3 kinds of certified reference materials (NIES CRM No.16 river sediment, NIES/NIRS typical Japanese diet CRM and NIES/WAMRL fish otolith CRM) and 10 kind of iron remains excavated at the ruins of Kaman-Kalehoyuk in Turkey. These samples and comparative standards were irradiated for 6 h at a thermal neutron flux of 3.7 x 1012 n cm-2s-1 in the Rikkyo University Research Reactor (TRIGA Mark-II, 100 kW). The irradiated samples were counted by multiparameter MCA (LN-9000, Laboratory Equipment Corporation). A coaxial Ge detector (relative efficiency of 21% and FWHM of 1.8 keV at 1332 keV) was used for the conventional counting method. For the coincidence counting method, the coaxial Ge detector along with a well-type NaI(Tl) detector (6 in.φ x 6 in., well 3 in.φ x 4 in.) was used. Using this method to determine Se, Hf, Ba, Cs, Co, Sb and Sc, the lower limit of the determination was improved by 2-4 times compared with the conventional counting method using the coaxial Ge detector. The determined values were in good agreement with the certified values. (author)

  12. The use of instrumental neutron activation analysis method in bio-sorption determination

    Full text: Recently, much attention is paid to the research and development of effective metal remediation methods. In industry, for the removal of metals from the industrial solutions and wastes, the expensive ion-exchange resin method of metal sorption is used today. The microbiological methods are much less expensive, are available and provide its application in natural conditions. The search for molybdenum bio sorbent was performed amongst Actinomyces strains. The 18 of Streptomyces strains were used. The data showed that all investigated strains uptake the molybdenum from the solution in various degrees. The molybdenum determination was performed using neutron activation analysis technique. In a nuclear reactor, the samples were treated with a steady flow of neutrons (5.1·1013) n·cm-2 sec-1 in 20 hours. The samples were stored for 6-7 days before analysis. The Actinomyces biomass uptake capacity was up to 94.5 %. The 8 cultures have the most high uptake capacity that varied from 87.4 to 94.5 %. Streptomyces sp. 39 and Streptomyces sp.32 have the lowest bio-sorption capacity amongst studied strains, which was 46.6% and 40 % respectively, whereas the bio sorption capacity of other cultures varied from 55.8 to 64.1%. The influence of some physical and chemical parameters (culture age, pH, temperature) on molybdenum bio-sorption was studied. Data showed that the change in pH, temperature and cultivation period lead to the increase of bio-sorption capacity

  13. Sesquiterpene Lactones from Artemisia Genus: Biological Activities and Methods of Analysis.

    Ivanescu, Bianca; Miron, Anca; Corciova, Andreia

    2015-01-01

    Sesquiterpene lactones are a large group of natural compounds, found primarily in plants of Asteraceae family, with over 5000 structures reported to date. Within this family, genus Artemisia is very well represented, having approximately 500 species characterized by the presence of eudesmanolides and guaianolides, especially highly oxygenated ones, and rarely of germacranolides. Sesquiterpene lactones exhibit a wide range of biological activities, such as antitumor, anti-inflammatory, analgesic, antiulcer, antibacterial, antifungal, antiviral, antiparasitic, and insect deterrent. Many of the biological activities are attributed to the α-methylene-γ-lactone group in their molecule which reacts through a Michael-addition with free sulfhydryl or amino groups in proteins and alkylates them. Due to the fact that most sesquiterpene lactones are thermolabile, less volatile compounds, they present no specific chromophores in the molecule and are sensitive to acidic and basic mediums, and their identification and quantification represent a difficult task for the analyst. Another problematic aspect is represented by the complexity of vegetal samples, which may contain compounds that can interfere with the analysis. Therefore, this paper proposes an overview of the methods used for the identification and quantification of sesquiterpene lactones found in Artemisia genus, as well as the optimal conditions for their extraction and separation. PMID:26495156

  14. Study on the determination of palladium in biological samples by the method of neutron activation analysis

    Palladium is one of platinum group elements present in the nature at very low concentrations. However with the use of this element in the automobile catalyzers Pd became a new pollutant. Besides, Pd has been studied in the preparation of new antitumour drugs. Consequently, there is a need to determine Pd concentrations in biological and environmental samples. This study presents palladium results obtained in the analysis of biological samples and reference materials using instrumental thermal and epithermal neutron activation analysis (INAA and ENAA). The solvent extraction and solid phase extraction separation methods were also applied before ENAA. The samples analyzed in this study were, reference material BCR 723 - Palladium, Platinum and Rhodium in road dust, CCQM-P63 automotive catalyst material of the Proficiency Test and bovine tissue samples containing palladium prepared in the laboratory. Samples and palladium synthetic standard were irradiated at the IEA-R1 nuclear research reactor under thermal neutron flux of about 4 x 10 12 n cm-2 s-1, during a period of 4 and 16 h for INAA and ENAA, respectively. The induced gamma activity of 109Pd to the sample and standard was measured using a hyper pure Ge detector coupled to a gamma ray spectrometer. The palladium concentration was calculated by comparative method. The gamma ray energy of 109Pd radioisotope measured was of 88.0 keV, located in a spectrum region of low energy where occurs the interference of X rays, 'Bremsstrahlung' radiations, as well as Compton effect of 24Na. The pre-separation of palladium from interfering elements by solvent extraction was performed using dimethylglyoxime complexant and chloroform as diluent. In the case of the pre separation procedure using solid reversed phase column, the palladium was retained using N,N-diethyl-N'-benzoyl thiourea complexant and eluted using ethanol. Aliquots of the resulting solutions from the pre-separations, free of interfering elements, were transferred

  15. Method Development of Cadmium Investigation in Rice by Radiochemical Neutron Activation Analysis

    Full text: A radiochemical neutron activation analysis for the determination of cadmium was investigated. A chemical separation of cadmium utilized ion exchange chromatography of a strong basic anion-exchange resin BIO-RAD 1X 8 (Chloride form). The adsorbing medium of 2M HCl was found to be the most suitable among the concentration attempted (2, 4, 6, 8 and 10M HCl) and the eluent for desorption of the cadmium from column was 8M NH3 solution. A chemical yield of 95% was found. The method has been evaluated by analyzing certified reference materials with 0.5.g/g (SRM 1577b, Bovine Liver) and 2.48.g/g (SRM 1566b, Oyster Tissue) cadmium. The agreement of the result with certified values is within 92% for Bovine Liver and 96% for Oyster Tissue. The method developed was applied to determine the cadmium concentrations in contaminated Thai rice. It was found that the cadmium concentrations ranged from 7.4 to 578.9 ppb

  16. Study on the manganese distribution in the soil of an agricultural field using neutron activation analysis method

    Manganese distribution in the soil of an agricultural field was evaluated by neutron activation analysis. The accuracy and precision of the method were verified by the analysis of two Standard Reference Materials with different manganese concentration in the experimental field, through one schematic diagram. (author). 7 refs., 1 fig., 2 tabs

  17. Trace elements determination in silicon and ferrosilicon reference materials by instrumental neutron activation analysis method

    The use of certified reference materials, CRM, is of uppermost importance in the rastreability realization of the measurement process. At times, CRM use is restricted by the non existence of a suitable CRM with similarity to the sample in respect to matrix composition or with element levels in different orders of magnitude. IPT Chemical Division launched a project to prepare a metallic silicon CRM, due to the requirements of the industries in this field. To characterize this new CRM, IPEN Nuclear Reactor Center is able to perform instrumental neutron activation analysis, INAA, a very suitable method for silicon matrix samples because they produce basically the short lived radionuclide 31 Si under thermal neutrons flux, which after radioactive decay, does not interfere in the determination of other elements. In this paper, it is presented the determination of As, Br, Co, Cr, K, Eu, Fe, La, Mn, Na Nb, Sb, Sm, Sc, Th, Tb, U, V, W and Yb in silicon CRM NBS SRM 57; ferrosilicon CRM IPT 56; IPT 70; NBS SRM 58a; NBS SRM 59a and silicon RM under preparation IPT 132. From the results, the accuracy and the precision of the process were assessed. (author)

  18. Study on Kο-standardization method of neutron activation analysis in HANARO research reactor

    The neutron activation analysis based on kο-standardization method (kο-NAA) has been known as one of the remarkable developments of NAA in recent with advantages of experimental simplicity, high accuracy, excellent flexibility with respect to irradiation and counting conditions, and suitability for computerization. This work has carried out to consider the application of kο-NAA on NAA 1 of HANARO research reactor such as the calibration of gamma-ray spectrometry and irradiation facility. α and f-values related to the reactor neutron spectrum parameters as main factor of irradiation quality are measured and some SRMs are analyzed to compare the accuracy of the measured results. The analytical results with the deviation mostly less than ±15% and all Z-score lower 1.5 in comparison between the experiment value and that value certified of some SRMs has shown a promising capability in application of kο-NAA on the HANARO research reactor

  19. A hybrid method for the analysis of learner behaviour in active learning environments

    Pahl, Claus

    2007-01-01

    Software-mediated learning requires adjustments in the teaching and learning process. In particular active learning facilitated through interactive learning software differs from traditional instructor-oriented, classroom-based teaching. We present behaviour analysis techniques for Web-mediated learning. Motivation, acceptance of the learning approach and technology, learning organisation and actual tool usage are aspects of behaviour that require different analysis techniques to be used. A h...

  20. Role of neutron activation analysis in metrology of modern inorganic trace analysis. Pt.1: Qualification of neutron activation analysis (NAA) as a primary ratio method of measurement

    The role of NAA in the metrology of modern inorganic trace analysis is to be discussed in a series of three papers, beginning from this one. They are: 1) the qualification of relative NAA as a primary method of measurement: 2) the unique function of parametric NAA as a 'back-up' method of relative NAA; and 3) the role of NAA in the characterization of a new generation CRMs suitable for quality control of microanalysis. The first of the series, the principle, the uncertainties and the traceability of NAA are analyzed. The qualification of NAA at the state of the art level as a primary ratio method is thus justified. An example is given to further verify the position of NAA as a primary ratio method. Advantages and drawbacks, as well as current status and future perspectives, of NAA as a primary method are discussed. Definitions of relevant terms and international norms are attached as appendices for the convenience of the reader

  1. METHODS AND MODELS FOR ANALYSIS OF THE ORGANIZATIONAL ECONOMICS ACTIVITY USED FOR DEVELOPMENT OF INFORMATICS SYSTEMS

    TEODORA VĂTUIU

    2014-10-01

    Full Text Available Study of organizational activity and highlighting problem situations that require specific solutions, require a detailed analysis of the models defined for the real system of the economic companies, regarded not as a sum of assets, but as organizations in which there are activities related into processes. In addition to the usual approach of using modeling languages in the development of information systems, in this paper we intend to present some examples that demonstrate the usefulness of a standard modeling language (UML to analyze organizational activities and to report problem situations that may occur in data management registered on primary documents or in processes that bring together activities. Examples that have been focused on a travel agency can be extrapolated to any other organization, and the diagrams can be used in different contexts, depending on the complexity of the activities identified.

  2. New method in the criminalistics: neutron-activation analysis of the human hair

    The application of the neutron activation analysis for the examination of human hair for criminological purposes is discussed. Earlier Nal scintillation detector and 256-channels analyzer were used and only form trace elements could be detected in the hair. Recently using Ge/Li detector and a 1024-channels analyzer 11 trace elements were detected in the human hair. (H.E.)

  3. An improved method for measuring soil microbial activity by gas phase flow injection analysis

    Gregory Doran; Alek Zander

    2012-01-01

    The rate of carbon dioxide production is commonly used as a measure of microbial activity in the soil. The traditional method of CO2 determination involves trapping CO2 in an alkali solution and then determining CO2 concentration indirectly by titration of the remaining alkali in the solution. This method is still commonly employed in laboratories throughout the world due to its relative simplicity and the fact that it does not require expensive, specific equipment. However, there are several...

  4. Cash Flow Analysis Using Methods of Measuring Financial Flows by Type of Activity

    Spineanu-Georgescu Luciana

    2011-01-01

    Analysis of financial balance through cash flows used to estimate future cash needs based on past situation, their knowledge would be useful to both shareholders interested in the existence of sufficient cash to pay dividends and creditors who are interested in recovering loans. Equally, knowledge of future cash flows of interest to potential investors updated cash flow method is a method of evaluation of the company.

  5. Studies on the method for determination of fluoride concentration in rat hard tissues by neutron activation analysis using 20F

    Neutron activation analysis method (non disruptive analysis, short time period measurement) has been recognized as a high precision analysis of fluoride concentration in hard tissue. Heat neutron irradiation analysis using instrumental neutron activation analysis (INAA) method was used to investigate 20F concentration. Results were as follows. F concentration in a dried material of hard tissue using INAA method can be fixed by measuring the 20F's energy peak for 10 seconds after neutron irradiation under 1 x 10 n/cm2·s for 10 seconds. Non responding time that is caused by short half reduction time of 20F can be recovered enough by a revise calculation. Reproducibility of measured fluoride concentration using INAA method was well stabilized. Rat hard tissue which takes no fluoride can be determined fluoride concentration without sodium restriction. Femur fluoride concentrations using INAA method had significant correlation with conventional microdiffusion analysis method (r=0.997, regression line: Y=1.13X + 2.98). Increase of fluoride density in dentine of rat molars under growing period according to fluoride intake was 1/3 of femurs and mandibles. (author)

  6. Methods and considerations for the analysis and standardization of assessing muscle sympathetic nerve activity in humans.

    White, Daniel W; Shoemaker, J Kevin; Raven, Peter B

    2015-12-01

    The technique of microneurography and the assessment of muscle sympathetic nerve activity (MSNA) are used in laboratories throughout the world. The variables used to describe MSNA, and the criteria by which these variables are quantified from the integrated neurogram, vary among studies and laboratories and, therefore, can become confusing to those starting to learn the technique. Therefore, the purpose of this educational review is to discuss guidelines and standards for the assessment of sympathetic nervous activity through the collection and analysis of MSNA. This review will reiterate common practices in the collection of MSNA, but will also introduce considerations for the evaluation and physiological inference using MSNA. PMID:26299824

  7. Trace element determination in human bones using the neutron activation analysis method

    This work presents the results obtained in the analysis of rib bone samples from normal human individuals by applying instrumental neutron activation analysis. In these analyses, the elements Br, Cl, Fe, K, Mg, Na, Rb, Sr and Zn were found at the ppm level and the elements Ca and P at the level of percentage. The precision and the of the results were evaluated by using biological reference materials NIST SRM 1577a Bovine Liver, IAEA A-11 Milk powder, NIES CRM 9 Sargasso e NIES CRM 10A Rice Flour Unpolished. (author). 5 refs., 3 tabs

  8. Evaluation and standardization of neutron activation analysis according to the K0 method in the RP-10 reactor

    It has been characterized and standardized an irradiation of the RP-10 Research Nuclear Reactor for use of the K0 method of neutron activation analysis using the Hoegdahl convention; also it has been evaluate the behaviour of such method in regard to the accuracy and precision of the results obtained in the quantitative multi elemental analysis of several certified materials of reference. In order to prove that the analytical method is totally under statistical control, it has been used the Heydorn method. It has been verified that the method is exact, precise and reliable to determine the aluminium, antimuonium, arsenic, bromine, calcium, chloride, copper, magnesium, manganese, sodium, titanium, vanadium, zinc and other elements. Also, they are discussed, in regard to the use of K0 constants, the different formalisms employed to calculate the integral of the reaction rate by nucleus in the activation. (author). 58 refs., 18 tabs., 6 figs

  9. An open source cryostage and software analysis method for detection of antifreeze activity.

    Buch, J L; Ramløv, H

    2016-06-01

    The aim of this study is to provide the reader with a simple setup that can detect antifreeze proteins (AFP) by inhibition of ice recrystallisation in very small sample sizes. This includes an open source cryostage, a method for preparing and loading samples as well as a software analysis method. The entire setup was tested using hyperactive AFP from the cerambycid beetle, Rhagium mordax. Samples containing AFP were compared to buffer samples, and the results are visualised as crystal radius evolution over time and in absolute change over 30 min. Statistical analysis showed that samples containing AFP could reliably be told apart from controls after only two minutes of recrystallisation. The goal of providing a fast, cheap and easy method for detecting antifreeze proteins in solution was met, and further development of the system can be followed at https://github.com/pechano/cryostage. PMID:27041219

  10. Analysis of cat oocyte activation methods for the generation of feline disease models by nuclear transfer

    Herrick Jason R

    2009-12-01

    Full Text Available Abstract Background Somatic cell nuclear transfer in cats offers a useful tool for the generation of valuable research models. However, low birth rates after nuclear transfer hamper exploitation of the full potential of the technology. Poor embryo development after activation of the reconstructed oocytes seems to be responsible, at least in part, for the low efficiency. The objective of this study was to characterize the response of cat oocytes to various stimuli in order to fine-tune existing and possibly develop new activation methods for the generation of cat disease models by somatic cell nuclear transfer. Methods First, changes in the intracellular free calcium concentration [Ca2+]i in the oocytes induced by a number of artificial stimuli were characterized. The stimuli included electroporation, ethanol, ionomycin, thimerosal, strontium-chloride and sodium (Na+-free medium. The potential of the most promising treatments (with or without subsequent incubation in the presence of cycloheximide and cytochalasin B to stimulate oocyte activation and support development of the resultant parthenogenetic embryos was then evaluated. Finally, the most effective methods were selected to activate oocytes reconstructed during nuclear transfer with fibroblasts from mucopolysaccharidosis I- and alpha-mannosidosis-affected cats. Results All treatments were able to elicit a [Ca2+]i elevation in the ooplasm with various characteristics. Pronuclear formation and development up to the blastocyst stage was most efficiently triggered by electroporation (60.5 +/- 2.9 and 11.5 +/- 1.7% and the combined thimerosal/DTT treatment (67.7 +/- 1.8 and 10.6 +/- 1.9%; incubation of the stimulated oocytes with cycloheximide and cytochalasin B had a positive effect on embryo development. When these two methods were used to activate oocytes reconstructed during nuclear transfer, up to 84.9% of the reconstructed oocytes cleaved. When the 2 to 4-cell embryos (a total of 220 were

  11. Analysis and classification of physical and chemical methods of fuel activation

    Fedorchak Viktoriya

    2015-12-01

    Full Text Available The offered article explores various research studies, developed patents in terms of physical and chemical approaches to the activation of fuel. In this regard, national and foreign researches in the field of fuels activators with different principles of action were analysed, evaluating their pros and cons. The article also intends to classify these methods and compare them regarding diverse desired results and types of fuels used. In terms of physical and chemical influences on fuels and the necessity of making constructive changes in the fuel system of internal combustion engines, an optimal approach was outlined.

  12. Application of different methods of neutron activation analysis to the determination of trace elements in rock samples

    In this report three different methods of neutron activation analysis applied to the determination of up to 20 trace elements in Egyptian rock samples and the results obtained are discussed. In Part I a physical approach is described for instrumental multielement activation analysis with whole neutron spectrum (without Cd-cover) using the monostandard (single comparator) method. 15 Samples representing different Egyptian granite rocks were analyzed. As many as 21 trace elements beside Fe, K and Na were determined. The accuracy of the method for nondestructive multielement analysis agrees within 3% with the relative method using multielement standards. In Part II a method is described for epithermal neutron activation analysis of 20 elements in granite rock samples using only one standard. Gold has been used as a single comparator due to its relatively high resonance integral value (Io = 400) and in addition, it is preferable on Co in order to obtain a large epithermal activation in a short irradiation. The method of calculation is simple and rapid and can be done using small calculator. In Part III experiments are described in which a neutron capture gamma-ray spectroscopy facility assembled at the Institute of Radiochemistry, KfK (for analytical purposes) using Cf252 neutron source of strength ∝ 6x107 n/sec, has been used to check its applicability and sensitivity for quantitative analyses of ores. The analysis of Sm, Gd and Mn in phosphate and monazite rock samples has been carried out. The results from this study show a variation of about 25% from the values determined by RNAA method. The reasons for this discrepancy are discussed and suggestions are made to optimize the conditions of measurement and irradiation. (orig./RB)

  13. Application of neutron activation analysis method in leaves of Casearia obliqua medicinal plant

    The pharmacological properties of medicinal plants have been related to the presence of organic compounds, however elements are also known to have an important participation in the active compounds constitution process. In this study, instrumental neutron activation analysis (INAA) was applied to determine elements in leaves of Casearia obliqua medicinal plant collected at two different locations in the Atlantic Forest, Brazil, SP. Soil samples collected from where this plant was grown were also analyzed in order to verify if there is a correlation between the elements present in soils and plant leaves. Br, Ca, Cl, Co, Cr, Cs, Fe, K, La, Mn, Na, Rb, Sb, Sc and Zn were determined in C. obliqua leaves and the elements As, Ca, Ce, Eu, Fe, Hf, La, Lu, Nd, Rb, Sc, Sm, Tb, Th, U and Zn in soils. Soil samples collected from two different locations presented similar concentrations for most elements. Likewise, C. obliqua leaves collected from the two locations presented similar elemental contents. These results suggest that analysis of extracts from these leaf samples and the evaluation of their pharmacological activities should be carried out. Certified reference materials IAEA-Soil-7, USGS W-1, NIST 1573a Tomato Leaves and NIST 1515 Apple Leaves were analyzed and the quality of the obtained results was assured. (author)

  14. Forward-looking activities: incorporating citizens' visions: A critical analysis of the CIVISTI method.

    Gudowsky, Niklas; Peissl, Walter; Sotoudeh, Mahshid; Bechtold, Ulrike

    2012-11-01

    Looking back on the many prophets who tried to predict the future as if it were predetermined, at first sight any forward-looking activity is reminiscent of making predictions with a crystal ball. In contrast to fortune tellers, today's exercises do not predict, but try to show different paths that an open future could take. A key motivation to undertake forward-looking activities is broadening the information basis for decision-makers to help them actively shape the future in a desired way. Experts, laypeople, or stakeholders may have different sets of values and priorities with regard to pending decisions on any issue related to the future. Therefore, considering and incorporating their views can, in the best case scenario, lead to more robust decisions and strategies. However, transferring this plurality into a form that decision-makers can consider is a challenge in terms of both design and facilitation of participatory processes. In this paper, we will introduce and critically assess a new qualitative method for forward-looking activities, namely CIVISTI (Citizen Visions on Science, Technology and Innovation; www.civisti.org), which was developed during an EU project of the same name. Focussing strongly on participation, with clear roles for citizens and experts, the method combines expert, stakeholder and lay knowledge to elaborate recommendations for decision-making in issues related to today's and tomorrow's science, technology and innovation. Consisting of three steps, the process starts with citizens' visions of a future 30-40 years from now. Experts then translate these visions into practical recommendations which the same citizens then validate and prioritise to produce a final product. The following paper will highlight the added value as well as limits of the CIVISTI method and will illustrate potential for the improvement of future processes. PMID:23204998

  15. An analysis method of the press information related with the nuclear activity in Argentina

    The articles published by the newspapers during the year 1987 were analyzed and classified according to their contents. An attribute was assigned to each article (positive, negative or neutral) in agreement with its connotation regarding the nuclear activity in Argentina. An ISIS base system was developed using these data. The purpose of this analysis was to evaluate the influence of the press in the public opinion. The relation between the different variables show the importance and approach (environmental, technico-scientifical or political) given by the press to the different subjects. The results show a general lack of knowledge about nuclear activities and a concern among the readers associated with the environmental risks, which calls for the need to develop an information program for the community. The fundamentals of this program should improve the organization in order to make the information reach the external demands, to promote educational programs and to continuously provide information to the press. (S.M.)

  16. Evaluation of accuracy, precision and determination limit in the human hair analysis using neutron activation method

    The accuracy, precision and determination limit were evaluated for determination of Al, As, Br, Ca, Cd, Cl, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Sb, Sc, Se, V and Zn in human head hair by instrumental neutron activation analysis. The precision was examined by analyzing human hair sample, and the results of relative standard deviations obtained ranged from 3.9 to 16.2%. The results accuracy was evaluated by using reference materials GBW 09101 Human Hair and NIES 5 Human Hair. Currie criterion was used for calculation of the determination limit. (author). 8 refs., 2 tabs

  17. Study on 99Mo production by Mo-solution irradiation method (3). Activation analysis of irradiation target

    The impurity concentrations in both (NH4)6Mo7O24 and K2MoO4 solutions, which were selected as the advanced targets of the Mo-solution irradiation method for 99Mo production, were determined by the instrumental Neutron Activation Analysis (NAA) using the k0-standardization method. As a result, Na, Mn and W were identified as impurities in the received molybdates. After the compatibility test with structural material (SUS304) under gamma-ray irradiation, activation analysis of the molybdate solutions by the NAA method was also carried out. It was found that the identified impurity concentrations stayed stably in the solutions and that no elements came from the structural material. However, a small corrosion of the structural material was observed from the ICP measurement. (author)

  18. The Cost of Company Occupational Accidents: An Activity Based Analysis using the SACA Method

    Rikhardsson, Pall M.; Impgaard, Martin

    - for evaluating the visible and hidden costs of corporate occupational accidents. It also focused on whether the registration, processing and reporting of these costs could be integrated in the corporate accounting information system. The project was based on case studies in 9 Danish companies within 3 different......The Systematic Accident Cost Analysis (SACA) project is a research project carried out during 2001 by The Aarhus School of Business and PricewaterhouseCoopers Denmark with financial support from The Danish National Working Environment Authority. It empirically tested a method - the SACA method...... industry sectors. The main conclusions are that only 2/3 of the costs of occupational accidents are visible in corporate accounting systems while 1/3 is hidden from management view. The highest cost of occupational accidents for a company with 3.600 employees was estimated to approximately $682...

  19. The studies for application of Ko-standardization method of neutron activation analysis on Dalat reactor

    The studies for application of the Ko-NAA method have been carried out in order to aim at creating a concrete procedure of the method, which is able to apply for practical samples. The results of the calibration of neutron spectrum parameters at cell 7-1, 13-2 and rotary rack on Dalat reactor, the calibration of detection efficiency of gamma spectrometers, the application and development of computer software for processing of gamma-ray spectra and for calculating of related problems (i.e. detector efficiency, neutron spectrum parameters, elemental concentration, etc.) and the quality control/assessment (QC/QA) with the analysis of the reference material IAEA-Soil7 have been presented as well as the application of the ko-NAA for practical samples in geological, archaeological, bio-medical and environmental objects has also been shown. (author)

  20. A development and integration of the concentration database for relative method, k0 method and absolute method in instrumental neutron activation analysis using Microsoft Access

    Instrumental Neutron Activation Analysis (INAA) is offen used to determine and calculate the concentration of an element in the sample by the National University of Malaysia, especially students of Nuclear Science Program. The lack of a database service leads consumers to take longer time to calculate the concentration of an element in the sample. This is because we are more dependent on software that is developed by foreign researchers which are costly. To overcome this problem, a study has been carried out to build an INAA database software. The objective of this study is to build a database software that help the users of INAA in Relative Method and Absolute Method for calculating the element concentration in the sample using Microsoft Excel 2010 and Microsoft Access 2010. The study also integrates k0 data, k0 Concent and k0-Westcott to execute and complete the system. After the integration, a study was conducted to test the effectiveness of the database software by comparing the concentrations between the experiments and in the database. Triple Bare Monitor Zr-Au and Cr-Mo-Au were used in Abs-INAA as monitor to determine the thermal to epithermal neutron flux ratio (f). Calculations involved in determining the concentration are the net peak area (Np), the measurement time (tm), the irradiation time (tirr), k-factor (k), thermal to epithermal neutron flux ratio (f), the parameters of the neutron flux distribution epithermal (α) and detection efficiency (εp). For Com-INAA databases, reference material IAEA-375 Soil was used to calculate the concentration of elements in the sample. CRM, SRM are also used in this database. After the INAA database integration, a verification process was to examine the effectiveness of the Abs-INAA was carried out by comparing the sample concentration between the in database and the experiment. The result of the experimental concentration value of INAA database software performed with high accuracy and precision. ICC

  1. Thick activation detectors for neutron spectrometry using different unfolding methods: sensitivity analysis and dose calculation

    This paper discusses the use of threshold detectors of extended sizes for low intensity neutron fields' characterization. The detectors were tested by the measurement of the neutron spectrum of an 241Am–Be source. Integral quantities characterizing the neutron field, required for radiological protection, have been derived by unfolding the measured data. A good agreement is achieved between the obtained results and those deduced using Bonner spheres. In addition, a sensitivity analysis of the results to the deconvolution procedure is given. - Highlights: ► Low intensity neutron fields' characterization using thick threshold detectors. ► Low activity 241Am–Be neutron source spectrum measurement. ► Integral quantities required for radiological protection have been derived. ► The results are in good agreement with those deduced using Bonner spheres. ► The results are not very sensitive to the chosen deconvolution procedure.

  2. Origin identification for Cantona, Puebla, obsidians by the analysis method of neutron activation (NAA)

    There are tests that most of the obsidian worked in the workshops of Cantona, Puebla, is coming from the mineral deposits of Oyameles-Zaragoza, but also has been detected obsidian that macroscopically belongs to other mineral deposits. The present work has as purpose to determine the provenance of an obsidian sample obtained in the Cantona Site to know if there was the presence of obsidian of other mineral deposits. For the study the neutron activation analysis was used to identify the presence of other deposits. An explanation on the treatment to the selected pieces is included, the preparation of the same ones for its irradiation in the nuclear reactor, the counting and statistical study of the results. Finally the results of the selected samples are presented, indicating their origin places, that time comes and the interpretation of the results is given. (Author)

  3. Activation analysis in Greece

    A review of research and development on NAA as well as examples of applications of this method are presented, taken from work carried out over the last 21 years at the Radioanalytical Laboratory of the Department of Chemistry in the Greek Nuclear Research Center ''Demokritos''. Improved and faster radiochemical NAA methods have been developed for the determination of Au, Ni, Cl, As, Cu, U, Cr, Eu, Hg and Mo in several materials, for the simultaneous determination of Br and I; Mg, Sr and Ni; As and Cu; As, Sb and Hg; Mn, Sr and Ba; Cd and Zn; Se and As; Mo and Cr in biological materials. Instrumental NAA methods have also been developed for the determination of Ag, Cl and Na in lake waters, Al, Ca, Mg and V in wines, 7 trace elements in biological materials, 17 trace elements in sediments and 20 minor and trace elements in ceramics. A comprehensive computer program for routine activation analysis using Ge(Li) detectors have been worked out. A rather extended charged-particle activation analysis program is carried out for the last 10 years, including particle induced X-ray emission (PIXE) analysis, particle induced prompt gamma-ray emission analysis (PIGE), other nuclear reactions and proton activation analysis. A special neutron activation method, the delayed fission neutron counting method is used for the analysis of fissionable elements, as U, Th, Pu, in samples of the whole nuclear fuel cycle including geological, enriched and nuclear safeguards samples

  4. Comparative analysis of dose rates in bricks determined by neutron activation analysis, alpha counting and X-ray fluorescence analysis for the thermoluminescence fine grain dating method

    In order to evaluate the age from the equivalent dose and to obtain an optimized and efficient procedure for thermoluminescence (TL) dating, it is necessary to obtain the values of both the internal and the external dose rates from dated samples and from their environment. The measurements described and compared in this paper refer to bricks from historic buildings and a fine-grain dating method. The external doses are therefore negligible, if the samples are taken from a sufficient depth in the wall. However, both the alpha dose rate and the beta and gamma dose rates must be taken into account in the internal dose. The internal dose rate to fine-grain samples is caused by the concentrations of natural radionuclides 238U, 235U, 232Th and members of their decay chains, and by 40K concentrations. Various methods can be used for determining trace concentrations of these natural radionuclides and their contributions to the dose rate. The dose rate fraction from 238U and 232Th can be calculated, e.g., from the alpha count rate, or from the concentrations of 238U and 232Th, measured by neutron activation analysis (NAA). The dose rate fraction from 40K can be calculated from the concentration of potassium measured, e.g., by X-ray fluorescence analysis (XRF) or by NAA. Alpha counting and XRF are relatively simple and are accessible for an ordinary laboratory. NAA can be considered as a more accurate method, but it is more demanding regarding time and costs, since it needs a nuclear reactor as a neutron source. A comparison of these methods allows us to decide whether the time- and cost-saving simpler techniques introduce uncertainty that is still acceptable. - Highlights: • Dose rates from natural U, Th and K in bricks were determined for the purpose of TL dating. • Results from neutron activation analysis, alpha counting and X-ray fluorescence analysis were compared. • Good match was observed for K determination. • Systematically lower dose rates from U and Th

  5. The comparison of the methods of activation analysis of nitrogen in diamond on cyclotron and microtron

    The successes in the scientific studies of natural diamond led to the fact that in several industrially - developed countries the crystals of syntetic diamond are produced in necessary quantities for precise - mechanical industry, abrasive machinery, scientific and space equipment, etc. Nevertheless, the world diamond for natural diamond (according to information sources) is still large. The study of origin, structure and properties of natural diamond is carried out by scientists for more than 300 years. Diamonds differ in share, structure and properties. The results of determination of admixture element composition of natural diamonds and development of different methods for obtaining of syntetic diamonds showed the 'main' admixture in diamonds is the nitrogen. The total quantitative concentration of nitrogen gives information on the origin, habitus, color, weight, quality and even on the geography of place of origin of natural diamond's crystals. In order to save the structure and properties of diamond's crystals, any developed method for nitrogen determination must be non-destructive. Such method was developed on the cyclotron of Institute of Nuclear Physics. The total concentrations of nitrogen's admixture in 70 crystals of natural diamond of weight from 15.5 to 716 mg were determined. The total concentration of nitrogen (0.1-2.68 %) in diamond was determined by the irradiation of crystal by fast neutrons, which were generated in thick beryllium target (h=4 mm) by the beam of protons or deuterons. In Samarkand State University, the calculation method for determination of nitrogen in diamonds was done using electron Bremsstrahlung from microtron MT - 22C (tungsten target h = 2 mm). The structure of diamond -crystal lattice in the knots of which are the atoms of carbon 12,13C. The admixture elements are in bound and free status. The determination of nitrogen in samples is done by positron - radiating radioisotope of nitrogen 13N(e+→γ: Eγ= 0.511 MeV) created

  6. Thick activation detectors for neutron spectrometry using different unfolding methods: sensitivity analysis and dose calculation

    Medkour Ishak-Boushaki, Ghania, E-mail: gmedkour@yahoo.com [Laboratoire SNIRM-Faculte de Physique, Universite des Sciences et de la Technologie Houari Boumediene, BP 32 El-Alia BabEzzouar, Algiers (Algeria); Boukeffoussa, Khelifa [Laboratoire SNIRM-Faculte de Physique, Universite des Sciences et de la Technologie Houari Boumediene, BP 32 El-Alia BabEzzouar, Algiers (Algeria); Idiri, Zahir [Centre de Recherche Nucleaire d' Alger, 02 Boulevard Frantz-Fanon, BP 399, Algiers (Algeria); Allab, Malika [Laboratoire SNIRM-Faculte de Physique, Universite des Sciences et de la Technologie Houari Boumediene, BP 32 El-Alia BabEzzouar, Algiers (Algeria)

    2012-03-15

    This paper discusses the use of threshold detectors of extended sizes for low intensity neutron fields' characterization. The detectors were tested by the measurement of the neutron spectrum of an {sup 241}Am-Be source. Integral quantities characterizing the neutron field, required for radiological protection, have been derived by unfolding the measured data. A good agreement is achieved between the obtained results and those deduced using Bonner spheres. In addition, a sensitivity analysis of the results to the deconvolution procedure is given. - Highlights: Black-Right-Pointing-Pointer Low intensity neutron fields' characterization using thick threshold detectors. Black-Right-Pointing-Pointer Low activity {sup 241}Am-Be neutron source spectrum measurement. Black-Right-Pointing-Pointer Integral quantities required for radiological protection have been derived. Black-Right-Pointing-Pointer The results are in good agreement with those deduced using Bonner spheres. Black-Right-Pointing-Pointer The results are not very sensitive to the chosen deconvolution procedure.

  7. Neutron activation analysis of archaeological artefacts using the conventional relative method: A realistic approach for analysis of large samples

    A new approach for analysis of entire potsherds of archaeological interest by INAA, using the conventional relative method, is described. The analytical method proposed involves, primarily, the preparation of replicates of the original archaeological pottery, with well known chemical composition (standard), destined to be irradiated simultaneously, in a well thermalized external neutron beam of the RP-10 reactor, with the original object (sample). The concentrations determined by irradiation of the entire replicates, in comparison with those obtained from the analysis of the aliquots, show a reasonable agreement; in particular, the percentage recoveries for lanthanum and scandium, with differences ≥ 10 % with respect to the reference. The basic advantage of this proposal is to avoid the need of performing complicated effect corrections when dealing with large samples, due to neutron self shielding, neutron self-thermalization and gamma ray attenuation. In addition, and in contrast with the other methods, the main advantages are the possibility of evaluating the uncertainty of the results and, fundamentally, validating the overall methodology. (orig.)

  8. Associations between diet and disease activity in ulcerative colitis patients using a novel method of data analysis

    Curno Richard

    2005-02-01

    Full Text Available Abstract Background The relapsing nature and varying geographical prevalence of ulcerative colitis (UC implicates environmental factors such as diet in its aetiology. Methods In order to determine which foods might be related to disease activity in UC a new method of dietary analysis was developed and applied. Eighty-one UC patients were recruited at all stages of the disease process. Following completion of a 7 d diet diary, clinical assessment including a sigmoidoscopic examination (scale 0 (normal mucosa to 6 (very active disease was conducted. Food weights for each person were adjusted (divided by the person's calorific intake for the week. Each food consumed was given a food sigmoidoscopy score (FSS calculated by summing the products of the (adjusted weight of food consumed and sigmoidoscopy score for each patient and occurrence of food and dividing by the total (adjusted weight of the food consumed by all 81 patients. Thus, foods eaten in large quantities by patients with very active disease have high FSSs and vice versa. Foods consumed by Results High FSS foods were characterized by high levels of the anti-thiamin additive sulfite (Mann-Whitney, p Conclusions The dietary analysis method described provides a new tool for establishing relationships between diet and disease and indicates a potentially therapeutic diet for UC.

  9. SLOWPOKE: neutron activation analysis

    Neutron activation analysis permits the non-destructive determination of trace elements in crude oil and its derivatives at high sensitivity (up to 10-9 g/g) and good precision. This article consists of a quick survey of the method followed by an illustration based on the results of recent work at the SLOWPOKE reactor laboratory at the Ecole Polytechnique

  10. A field method for assessing body composition by portable XRF bromine analysis: Validation against instrumental neutron activation

    Full text: Extracellular water space (ECW) is expanded in acute illness or in catabolic states. The assessment of change in ECW provides a simple method for monitoring nutritional status. ECW can be measured by Br dilution. A small amount of natural Br (10-17mg per Kg of body weight) is given orally. The concentration of Br in plasma is measured prior and 3 hours following the administration. Plasma is analysed for Br either by ion-exchange chromatography, or by non-destructive methods, such as instrumental neutron activation analysis (INAA) or X-ray fluorescence (XRF). We developed a method for the rapid analysis of Br in plasma with a small hand-held, XRF instrument consisting of a 30mCi Cd-109 source and an electronically-cooled solid-state Xray detector. 128 plasma samples were analysed from 64 volunteers aged 19 to 84y. The samples were measured first with the XRF instrument and then by INAA using the nuclear reactor of the research center 'Democritos' by the 79Br(n,γ)80Br neutron capture reaction. The samples were exposed to 2x1013n/cm2/s for 3 min. Detection of the 80Br (t1/2= 17.8 min) gamma-ray (616.2 KeV) followed 3 min after the irradiation using a liquid nitrogen-cooled purified Ge photon detector. We found the XRF instrument to be highly correlated with the neutron activation measurements (R= 1.000 for 7 standards, R = 0.997 for human plasma samples). We also observed that, in our group of volunteers, ECW was able to assess nutritional status as determined by in vivo neutron activation analysis. This simple method makes body composition measurements widely available as the main outcome of nutritional and pharmaceutical anabolic interventions. (author)

  11. Comparative analysis of dose rates in bricks determined by neutron activation analysis, alpha counting and X-ray fluorescence analysis for the thermoluminescence fine grain dating method

    Bártová, H.; Kučera, J.; Musílek, L.; Trojek, T.

    2014-11-01

    In order to evaluate the age from the equivalent dose and to obtain an optimized and efficient procedure for thermoluminescence (TL) dating, it is necessary to obtain the values of both the internal and the external dose rates from dated samples and from their environment. The measurements described and compared in this paper refer to bricks from historic buildings and a fine-grain dating method. The external doses are therefore negligible, if the samples are taken from a sufficient depth in the wall. However, both the alpha dose rate and the beta and gamma dose rates must be taken into account in the internal dose. The internal dose rate to fine-grain samples is caused by the concentrations of natural radionuclides 238U, 235U, 232Th and members of their decay chains, and by 40K concentrations. Various methods can be used for determining trace concentrations of these natural radionuclides and their contributions to the dose rate. The dose rate fraction from 238U and 232Th can be calculated, e.g., from the alpha count rate, or from the concentrations of 238U and 232Th, measured by neutron activation analysis (NAA). The dose rate fraction from 40K can be calculated from the concentration of potassium measured, e.g., by X-ray fluorescence analysis (XRF) or by NAA. Alpha counting and XRF are relatively simple and are accessible for an ordinary laboratory. NAA can be considered as a more accurate method, but it is more demanding regarding time and costs, since it needs a nuclear reactor as a neutron source. A comparison of these methods allows us to decide whether the time- and cost-saving simpler techniques introduce uncertainty that is still acceptable.

  12. Forensic Activation Analysis

    The high sensitivity of high-flux (reactor) thermal-neutron activation analysis (NAA) for the detection and quantitative measurement of a large number of elements has led, in recent years, to a considerable degree of application of the method in the area of scientific crime investigation (criminalistics). Thus, in a Forensic Activation Analysis Bibliography recently compiled by the author, some 135 publications in this field are listed - and more are appearing quite rapidly. The nondestructive character of the purely-instrumental form of the method is an added advantage in forensic work, since evidence samples involved in actual criminal cases are not destroyed during analysis, but are preserved intact for possible presentation in court. Quite aside from, or in addition to, use in court, NAA results can be very helpful in the investigative stage of particular criminal cases. The ultra sensitivity of the method often enables one to analyze evidence specimens that are too tiny for meaningful analysis by more conventional elemental analysis methods. Also, this high sensitivity often enables one to characterize, or individualize, evidence specimens as to the possibility of common origin - via the principle of multi-element trace-constituent characterization

  13. Sesquiterpene Lactones from Artemisia Genus: Biological Activities and Methods of Analysis

    Bianca Ivanescu; Anca Miron; Andreia Corciova

    2015-01-01

    Sesquiterpene lactones are a large group of natural compounds, found primarily in plants of Asteraceae family, with over 5000 structures reported to date. Within this family, genus Artemisia is very well represented, having approximately 500 species characterized by the presence of eudesmanolides and guaianolides, especially highly oxygenated ones, and rarely of germacranolides. Sesquiterpene lactones exhibit a wide range of biological activities, such as antitumor, anti-inflammatory, analges...

  14. Optimization of crude enzyme preparation methods for analysis of glutamine synthetase activity in phytoplankton and field samples

    WANG Yujue; WANG Dazhi; HONG Huasheng

    2009-01-01

    Glutamine synthetase (GS) is an important enzyme involved in nitrogen assimilation and metabolism in marine phytoplankton. However, little work has been done in situ due to the limitation of crude enzyme preparation methods. In this study, three enzyme preparation methods, high-speed centrifugation (HC, <10 000 g), ultracentrifugation (UC, 70 000 g), and ultrafiltration (UF) with 100 kμ, molecular weight cutoff, were compared using two diatom species (Asterionellopsis glacialis and Thalassiosira weissflogii), and two dinoflagellate species (Alexandrium catenella and Prorocentrum donghaiense) as experimental materials together with field samples collected from Xiamen Harbor, China. The results showed that HC is the best method to prepare crude enzymes for glutamine synthetase activity (GSA) in diatom species and diatom-dominant samples, while UF is the best method to extract GS from dinoflagellate species and dinoflagellate-dominant samples. For the HC method, the optimal centrifugal speed and time were 10 000 g and 35 min, respectively, and under these conditions, the highest GSA was obtained in all samples. This study indicates that both methods (HC and UF) overcome the limitation of centrifugal speed and could be applied to in situ GSA analysis, especially at sea.

  15. Forensic activation analysis

    Basic principles of neutron activation analysis are outlined. Examples of its use in police science include analysis for gunshot residues, toxic element determinations and multielement comparisons. Advantages of neutron activation analysis over other techniques are described. (R.L.)

  16. Determination of antioxidant activity in herbal ingredients for foods using new methods of chemical analysis

    Katalina Muñoz

    2012-06-01

    Full Text Available A new procedure has been used to separate and quantify the free radical-scavenging activity of individual compounds 18 samples of Thymus vulgaris and 12 samples of Rosmarinus officinalis (both used as natural food preservatives, based on the combination of HPTLC (High Performance Thin Layer Chromatography and postchromatographic DPPH● radical derivatization. The compounds thymol and rosmarinic acid in T. vulgaris and R. officinalis, respectively, were identified by comparisons of their Rf values and UV spectra to standards analyzed under identical analytical conditions, while the quantitative data were calculated from their calibration curves. We found that not only that the biomass yield but also the metabolite content in herbs, depend on the ecotype (genetics and on the agro ecological conditions. The effect of the ambient on the metabolite content is extremely significant and also on their antioxidant activity (One-way ANOVA with Newman-Keuls Multiple Comparison post test was performed using GraphPad Prism version 4.00 for Windows, GraphPad Software. This work pretends to demonstrate the great importance of using new technologies for the selection of the best materials used as natural food preservatives.

  17. Application of the activation analysis using the method of retarded fission neutrons counting for the determination of some fissionable nuclides

    A system for the detection and counting of delayed neutrons which allows the analysis of some fissile and fertile nuclides, in samples of milligram size, was developed. This was applied for the analysis of natural uranium and thorium and also for determining the 235U/238U ratio in non-irradiated samples which contain uranium with different degrees of enrichment in 235U. The spectrum of activated neutrons was varied in order to discriminate the nuclides, by covering or not the sample with a material (cadmium or boron) able to absorb low energy neutrons. Determination of 235U/238U ratios, through the number of delayed neutrons, was made by drawing a calibration curve using standards ranging from 0.5% to 93% on 235U; the accuracy of the method was also examined. In a first step, conditions for a simultaneous and non-destructive analysis of uranium and thorium were developed. The interference between these two nuclides was studied, using simulated samples. Real samples were provided by Nuclemon and IAEA. For samples with uranium concentration in the range of percentages and thorium concentration of some ppm, uranium interferes in the determination of thorium through the non-destructive analytical method. For this case, a fast and quantitative chemical method was studied which allows for the separation of thorium from uranium before the determination of throrium concentration by counting the delayed fission neutrons. It was found that the results obtained by both destructive and non-destructive methods are very consistent and can be considered statistically equivalent within a confidence level of 95%. (Author)

  18. Comparison of two semi-absolute methods. k0-instrumental neutron activation analysis and fundamental parameter method X-ray fluorescence spectrometry for Ni-based alloys

    Nickel based alloys play important role in nuclear, mechanical and chemical industry. Two semi-absolute standardless methods, k0-instrumental neutron activation analysis (k0-INAA) and fundamental parameter X-ray fluorescence spectrometry (FP-XRF) were used for the characterization of certified nickel based alloys. The optimized experimental conditions for NAA provided results for 18 and XRF for 15 elements. Both techniques were unable to quantify some important alloy making elements. However, both reported results of other elements as information values. The techniques were analyzed for their sensitivity and accuracy. Sensitivity was evaluated by the number of elements determined by each technique. Accuracy was ascertained by using the linear regression analysis and the average root mean squared error.

  19. Analysis for trace mercury concentration. I. Critical evaluation of current procedures. II. A proposed method for determination by instrumental neutron activation analysis

    Current methods of sample pretreatments, digestion, lyophilization and extraction, have been found to lead to considerable loss of mercury, at an initial mercury concentration of 1 μg/g, and less. Storage of solutions of mercury at concentrations of less than 1 μg/ml, in glass, Teflon and polyethylene containers, leads to losses by adsorption. Electrochemical reduction of mercury to the metal, and subsequent volatilization, is postulated as the mechanism of loss from the samples studied during lyophilization. A method of instrumental neutron activation analysis, which obviates the above pretreatments, has been developed for mercury concentrations as low as 1 ng/ml

  20. Neutron Activation Analysis

    Corliss, William R.

    1968-01-01

    In activation analysis, a sample of an unknown material is first irradiated (activated) with nuclear particles. In practice these nuclear particles are almost always neutrons. The success of activation analysis depends upon nuclear reactions which are completely independent of an atom's chemical associations. The value of activation analysis as a research tool was recognized almost immediately upon the discovery of artificial radioactivity. This book discusses activation analysis experiments, applications and technical considerations.

  1. Application of neutron activation analysis

    The physical basis and analytical possibilities of neutron activation analysis have been performed. The number of applications in material engineering, geology, cosmology, oncology, criminology, biology, agriculture, environment protection, archaeology, history of art and especially in chemical analysis have been presented. The place of the method among other methods of inorganic quantitative chemical analysis for trace elements determination has been discussed

  2. Internal standard method in α spectrometric determination of uranium and thorium radioisotopes using instrumental neutron activation analysis

    A new approach to α spectrometric determination of the radioisotopes of uranium and thorium was developed for environmental samples based on 238U and 232Th as internal standards. 238U and 232Th were accurately determined in the sample by simultaneous instrumental neutron activation analysis. Other aliquots of the sample were totally dissolved, uranium and thorium separated by anion exchange, and thin sources electroplated for α spectrometry. From the known mass concentrations of 238U and 232Th, their activity concentrations were obtained, and thus from the relative ratios of uranium (234U, 235U, 238U) and thorium (228Th, 230Th, 232Th) radioisotopes in the α spectra, the absolute isotopic activity concentrations were derived. The advantages of the procedure are that neither the chemical recovery of the radiochemical separation nor the counting efficiency of the α spectrometer is required; the use of internal standards eliminates the need for addition of expensive, calibrated, external radioisotopic tracers such as 232U and 229Th. The new approach was tested on some certified environmental reference materials and compared with the classical method using external radioisotopic tracers. It may advantageously be combined with the standard approach to obtain an independent set of data for quality control. 25 refs

  3. The neutron activation analysis in the study of Langmuir-Blodgett multilayers composition - relation to other methods of investigation

    The features of the neutron activation analysis (NAA) used in the study of Langmuir-Blodget (LB) multilayers composition are compared with the following analytical techniques: radiometry, spectrophotometry, IR-spectroscopy and electron spectroscopy for chemical analysis. A very important advantage of NAA is possibility for the simultaneous determination of all the inorganic ions in the sample, especially when LB multilayers serve as models of biological systems. Thus competitive reactions of bivalent and monovalent cations (Ca2+/Na+, K+) or specific reactions of counterions of equal charge (Zn2+/Cd2+. HPO42-/HAsO42-, SO42-/CrO42-) can be investigated with great accuracy. The parallel application of onother analytical technique is necessary when the structure of the multilayers, their stability, the molecular interactions or the binding energies of the elements are to be studied. An attempt to classify roughly the applicability of each method to some particular counterions is given. Such characteristics as the lower limit of detection, simplicity of the analysis accessibility, rapidity, etc. have been taken into consideration

  4. Validation of the instrumental neutron activation analysis method for mercury analysis in hair samples used for biomonitoring of mercury environmental contamination

    Environmental mercury contamination has lately become of widespread concern in Brazil owing to gold extraction activities in the Amazon region and also to industrial activities. It is estimated that tonnes of mercury are thrown in the rivers of the Amazon region annually or are evaporated into the open air owing to the amalgamation procedure employed in gold extraction. In the present work, as pail of an IAEA Co-ordinated Research Programme (CRP), three main population groups were studied: a control group of individuals with no suspicion of contamination by mercury; a group of people living near the Billings Dam, located in one of the most heavily industrialized parts of the country, and several Indian tribes living in Xingu Park, an Indian reservation located in the Amazon region. An important part of the CRP was the validation of the analytical methodology for die analysis of total mercury in the hair samples of the population groups studied. Instrumental neutron activation analysis (INAA) was chosen for the analysis of mercury in these samples. It has the advantage of being non-destructive, which can be quite convenient when dealing with a large number of samples, which is the case in epidemiological studies. The experimental procedure consisted of irradiation of the hair samples in the IEA-R1 nuclear research reactor and measurement of the gamma radioactivity of 197Hg. For the validation of the analytical methodology, the following reference materials (RMs) were analysed: IAEA MA-A-2/TM Fish Flesh Homogenate; SHINR GBW-9101 Chinese Human Hair and the candidate RMs IAEA-085 and IAEA-086 Human Hair. The recently acquired RM BCR CRM-397 was also analysed. The accuracy and precision of the INAA method for the analysis of these RMs is discussed, as well as the applicability of the method to the analysis of mercury in the hair of the population groups studied. (author)

  5. Multielement analysis of human hair and kidney stones by instrumental neutron activation analysis with the k{sub 0}-standardization method

    Abugassa, I.; Sarmani, S.B. [Department of Nuclear Science, Universiti Kebangsaan Malaysia, Bangi, Selangor (Malaysia); Samat, S.B. [Department of Physics, Universiti Kebangsaan Malaysia, Bangi, Selangor (Malaysia)

    1999-06-01

    This paper focuses on the evaluation of the k{sub 0} method of instrumental neutron activation analysis in biological materials. The method has been applied in multielement analysis of human hair standard reference materials from IAEA, No. 085, No. 086 and from NIES (National Institute for Environmental Sciences) No. 5. Hair samples from people resident in different parts of Malaysia, in addition to a sample from Japan, were analyzed. In addition, human kidney stones from members of the Malaysian population have been analyzed for minor and trace elements. More than 25 elements have been determined. The samples were irradiated in the rotary rack (Lazy Susan) at the TRIGA Mark II reactor of the Malaysian Institute for Nuclear Technology and Research (MINT). The accuracy of the method was ascertained by analysis of other reference materials, including 1573 tomato leaves and 1572 citrus leaves. In this method the deviation of the 1/E{sup 1+{alpha}} epithermal neutron flux distribution from the 1/E law (P/T ratio) for true coincidence effects of the {gamma}-ray cascade and the HPGe detector efficiency were determined and corrected for.

  6. Study on activation analysis

    High purity aluminum has been analyzed by neutron activation analysis. The determination of copper contents is aluminum has been used to evaluate its purity level. A new sensitive method has been developed by using graphite thermal column to reduce or eliminate the interference of 24Na which is generated from 27Al (n,α) 24Na reaction by fast neutron. Influence for activity of 24Na due to above reaction is found to be between 2.3 - 2.8 %. Copper contents in the high purity aluminum come out 0.542±0.084 ppm. In addition, contents of 23 other impurity elements (<0.1 - 0.01 ppm) are measured using general method after detection limit and optimum conditions are established. (author)

  7. Contribution of Italy to the activities on intercomparison of analysis methods for seismically isolated nuclear structures: Finite element analysis of lead rubber bearings

    This paper presents a summary of the results of nonlinear Finite Element (FE) analyses carried out by ENEL-Ricerca, Hydraulic and Structural Centre and ENEA-ERG-SIEC-SISM, on Lead Rubber Bearings (LRBs). Activities were carried out in the framework of the four years' Coordinated Research Programme (CRP) of the International Atomic Energy Agency (IAEA) on Intercomparison of Analysis Methods for Seismically Isolated Nuclear Structures. The bearing Finite Element Models (FEMs) are validated through comparisons of the numerical results with experimental test data. The reliability of FEMs for simulating the behaviour of rubber bearings is presented and discussed. (author)

  8. Comparative analysis of dose rates in bricks determined by neutron activation analysis, alpha counting and X-ray fluorescence analysis for the thermoluminescence fine grain dating method

    Bártová, H.; Kučera, Jan; Musílek, L.; Trojek, T.

    2014-01-01

    Roč. 104, NOV (2014), s. 393-397. ISSN 0969-806X. [1st International Conference on Dosimetry and its Applications (ICDA). Prague, 23.6.2013-28.6.2013] R&D Projects: GA MŠk(XE) LM2011019 Institutional support: RVO:61389005 Keywords : Alpha coutning * neutron activation analysis * X-ray fluorescence * thermoluminescence dating * dose rate Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.380, year: 2014

  9. Analysis of two precipitation methods on the yield, structural features and activity of sulfated polysaccharides from Gracilaria cornea (Rhodophyta

    Ricardo Basto Souza

    2015-03-01

    Full Text Available The global demand for natural products from seaweeds has increased worldwide; however, no description of the use of isoamly alcohol (IAA for obtaining of sulfated polysaccharides (SPs has been reported. We investigated the efficiency of two precipitation methods (M in obtaining SPs from the red seaweed Gracilaria cornea. SPs enzymatically isolated were concentrated with cetylpyridinium chloride (M I or IAA (M II and extracts were examined with regard to their yield, structural features and in vitro effects on the activated partial thromboplastin time (APTT using normal human plasma and standard heparin (193 IU mg-1. Yield difference reached 12.99%. Quantitative determination of sulfate was similar between the two methods (̴ 26%, but extracts revealed different pattern on charge density by agarose gel electrophoresis. Whereas both extracts revealed as agarocolloids, alternative M II was also efficient for lipids, proteins and nucleic acids according to the infrared analysis. Extracts had virtually no effect on APPT (1.95 and 2 IU mg-1 for M I and M II, respectively. The results revealed IAA as an alternative solvent for obtaining SPs from the red seaweed G. cornea, depending on the industry’ usage criterion.

  10. An Analysis of the Romanian General Accounting Plan. Opportunities for Adaptation to the Activity-Based Costing (ABC) Method

    Irina-Alina Preda; Sorinel Capusneanu

    2008-01-01

    In this article, we analyze the causes that have led to the improvement of the Romanian general accounting plan according to the Activity- Based Costing (ABC) method. We explain the advantages presented by the dissociated organization of management accounting, in contrast with the tabular- statistical form. The article also describes the methodological steps to be taken in the process of recording book entries, according to the Activity-Based Costing (ABC) method in Romania.

  11. An Analysis of the Romanian General Accounting Plan. Opportunities for Adaptation to the Activity-Based Costing (ABC Method

    Irina-Alina Preda

    2008-11-01

    Full Text Available In this article, we analyze the causes that have led to the improvement of the Romanian general accounting plan according to the Activity- Based Costing (ABC method. We explain the advantages presented by the dissociated organization of management accounting, in contrast with the tabular- statistical form. The article also describes the methodological steps to be taken in the process of recording book entries, according to the Activity-Based Costing (ABC method in Romania.

  12. Methods of Multivariate Analysis

    Rencher, Alvin C

    2012-01-01

    Praise for the Second Edition "This book is a systematic, well-written, well-organized text on multivariate analysis packed with intuition and insight . . . There is much practical wisdom in this book that is hard to find elsewhere."-IIE Transactions Filled with new and timely content, Methods of Multivariate Analysis, Third Edition provides examples and exercises based on more than sixty real data sets from a wide variety of scientific fields. It takes a "methods" approach to the subject, placing an emphasis on how students and practitioners can employ multivariate analysis in real-life sit

  13. Active Learning Methods

    Zayapragassarazan, Z.; Kumar, Santosh

    2012-01-01

    Present generation students are primarily active learners with varied learning experiences and lecture courses may not suit all their learning needs. Effective learning involves providing students with a sense of progress and control over their own learning. This requires creating a situation where learners have a chance to try out or test their…

  14. Development of a data base system and concentration calculation for neutron activation analysis as per the k0 method

    One of the most important nuclear analytical techniques is the neutron activation analysis used to determine which elements and their proportion are included within an analysis sample. A sample is undergone to the procedures of the technique, and the information, which is dispersed, is generated in each phase of this process. Therefore, it is necessary this information should be organized properly for its better use

  15. A simple and rapid method for the determination of iodine in rice samples by radiochemical neutron activation analysis

    A simple and rapid method has been developed for the determination of iodine in rice samples by radiochemical neutron activation analysis. Irradiated rice powder was decomposed together with an iodide carrier solution containing I-131 on heating in a sodium hypochlorite solution. After decomposition, the solution was acidified with hydrochloric acid, and the insoluble residue was filtered off. To the filtrate sodium sulfite solution and palladium chloride solution were added, and the precipitate of palladium iodide was separated with a glass fiber filter paper. Iodine contents of rice were calculated from the peak areas under the 443 keV γ-ray of I-128 in the precipitate and comparative stand ard. Corrections for the chemical recovery were applied to them by means of the areas under the 365 keV γ-ray of I-131. This method was applied to the certified refe rece materials, IAEA wheat flour RM-V-5 and NBS orchard leaves SRM 1571. The results were in good agreement with the recommended values. Iodine contents of rice samples of two different origins in Japan were found to be of the order of 100ng g-1 (dry weight base). The recovery of iodine in this procedure was about 80%. Decontamination factors for Mn, Cl, Na, and Br in the final fraction were 7 x 103, 2 x 104, 3 x 104, and 2 x 102, respectively. The time required for the chemical procedure was about 15 min, and the limit of determination was 0.7 ng of iodine in a sample of 1 g. (author)

  16. Analysis of numerical methods

    Isaacson, Eugene

    1994-01-01

    This excellent text for advanced undergraduates and graduate students covers norms, numerical solution of linear systems and matrix factoring, iterative solutions of nonlinear equations, eigenvalues and eigenvectors, polynomial approximation, and other topics. It offers a careful analysis and stresses techniques for developing new methods, plus many examples and problems. 1966 edition.

  17. Assessment of Thorium Analysis Methods

    The Assessment of thorium analytical methods for mixture power fuel consisting of titrimetry, X-ray flouresence spectrometry, UV-VIS spectrometry, alpha spectrometry, emission spectrography, polarography, chromatography (HPLC) and neutron activation were carried out. It can be concluded that analytical methods which have high accuracy (deviation standard < 3%) were; titrimetry neutron activation analysis and UV-VIS spectrometry; whereas with low accuracy method (deviation standard 3-10%) were; alpha spectrometry and emission spectrography. Ore samples can be analyzed by X-ray flourescnce spectrometry, neutron activation analysis, UV-VIS spectrometry, emission spectrography, chromatography and alpha spectometry. Concentrated samples can be analyzed by X-ray flourescence spectrometry; simulation samples can be analyzed by titrimetry, polarography and UV-VIS spectrometry, and samples of thorium as minor constituent can be analyzed by neutron activation analysis and alpha spectrometry. Thorium purity (impurities element in thorium samples) can be analyzed by emission spectography. Considering interference aspects, in general analytical methods without molecule reaction are better than those involving molecule reactions (author). 19 refs., 1 tabs

  18. Improvements in an in vivo neutron activation analysis (NAA) method for the measurement of fluorine in human bone

    We previously published a method for the in vivo measurement of bone fluoride using neutron activation analysis (NAA) and demonstrated the utility of the technique in a pilot study of environmentally exposed people. The method involved activation of the hand in an irradiation cavity at the McMaster University Accelerator Laboratory and acquisition of the resultant γ-ray signals in a ‘4π’ NaI(Tl) detector array of nine detectors. In this paper we describe a series of improvements to the method. This was investigated via measurement of hand simulating phantoms doped with varying levels of fluorine and fixed amounts of sodium, chlorine and calcium. Four improvements to the technique were tested since our first publication. The previously published detection limit for phantom measurements using this system was 0.66 mg F/g Ca. The accelerator irradiation and detection facilities were relocated to a new section of the laboratory and one more detector was added to the detection system. This was found to reduce the detection limit (possibly because of better detection shielding and additional detector) to 0.59 mg F/g Ca, a factor of 1.12. A new set of phantoms was developed and in this work we show that they improved the minimum detectable limit for fluoride in phantoms irradiated using neutrons produced by 2.15 MeV protons on lithium by a factor of 1.55. We compared the detection limits previously obtained using a summed signal from the nine detectors with the detection limit obtained by acquiring the spectra in anticoincidence mode for reduction of the disturbing signal from chlorine in bone. This was found to improve the ratio of the detection of fluorine to chlorine (an interfering signal) by a factor of 2.8 and the resultant minimum detection limit was found to be reduced by a factor of 1.2. We studied the effects of changing the timing of γ-ray acquisition. Our previously published data used a series of three 10 s acquisitions followed by a 300 s count

  19. Studies on the method for determination of fluoride concentration in rat hard tissues by neutron activation analysis using sup 20 F

    Nakakura, Tadao (Nippon Dental Univ., Tokyo (Japan))

    1991-04-01

    Neutron activation analysis method (non disruptive analysis, short time period measurement) has been recognized as a high precision analysis of fluoride concentration in hard tissue. Heat neutron irradiation analysis using instrumental neutron activation analysis (INAA) method was used to investigate {sup 20}F concentration. Results were as follows. F concentration in a dried material of hard tissue using INAA method can be fixed by measuring the {sup 20}F's energy peak for 10 seconds after neutron irradiation under 1 x 10 n/cm{sup 2}center dots for 10 seconds. Non responding time that is caused by short half reduction time of {sup 20}F can be recovered enough by a revise calculation. Reproducibility of measured fluoride concentration using INAA method was well stabilized. Rat hard tissue which takes no fluoride can be determined fluoride concentration without sodium restriction. Femur fluoride concentrations using INAA method had significant correlation with conventional microdiffusion analysis method (r=0.997, regression line: Y=1.13X + 2.98). Increase of fluoride density in dentine of rat molars under growing period according to fluoride intake was 1/3 of femurs and mandibles. (author).

  20. Validation of k0 standardization method in neutron activation analysis-The use of Kayzero for Windows programme at the nuclear physics institute, Rez

    The goal of this work was to validate the method of the k0 standardization in neutron activation analysis at the laboratory of neutron activation analysis in Rez using the Kayzero for Windows software package. For verification of the precision and accuracy of the method two types of reference materials were used. One was a set of synthetic materials aimed at checking the implementation of k0 standardization. The others were matrix standard reference materials of the US National Institute of Standards and Technology comprising several types of matrices. In general, good agreement was obtained between results of this work and values in certificates of the individual reference materials, thus proving the accuracy of our results and successful implementation of the method for analysis of real samples. In addition, detection limits for more than 50 elements were evaluated.

  1. Methods for Risk Analysis

    Many decision-making situations today affect humans and the environment. In practice, many such decisions are made without an overall view and prioritise one or other of the two areas. Now and then these two areas of regulation come into conflict, e.g. the best alternative as regards environmental considerations is not always the best from a human safety perspective and vice versa. This report was prepared within a major project with the aim of developing a framework in which both the environmental aspects and the human safety aspects are integrated, and decisions can be made taking both fields into consideration. The safety risks have to be analysed in order to be successfully avoided and one way of doing this is to use different kinds of risk analysis methods. There is an abundance of existing methods to choose from and new methods are constantly being developed. This report describes some of the risk analysis methods currently available for analysing safety and examines the relationships between them. The focus here is mainly on human safety aspects

  2. Simultaneous determination of Ti, Cr, Fe, Cu, Ga and Zr in aluminium alloys by charged-particle activation analysis using the internal standard method

    In order to study the application of the newly developed internal standard method for charged-particle activation analysis, simultaneous determination of Ti, Cr, Fe, Cu, Ga and Zr in several commercial aluminium alloys was tried using the respective proton-induced reactions. As a result, it could be proved that the best precision and accuracy are also obtained in these determinations. (author)

  3. Activity based costing (ABC Method

    Prof. Ph.D. Saveta Tudorache

    2008-05-01

    Full Text Available In the present paper the need and advantages are presented of using the Activity BasedCosting method, need arising from the need of solving the information pertinence issue. This issue has occurreddue to the limitation of classic methods in this field, limitation also reflected by the disadvantages ofsuch classic methods in establishing complete costs.

  4. 13. seminar 'Activation analysis'

    Collection of the abstracts of contributions to the seminar covering broad ranges of application of activation analysis and improvements of systems and process steps. Most of them have been prepared separately for the energy data bases. (RB)

  5. Methods for RNA Analysis

    Olivarius, Signe

    While increasing evidence appoints diverse types of RNA as key players in the regulatory networks underlying cellular differentiation and metabolism, the potential functions of thousands of conserved RNA structures encoded in mammalian genomes remain to be determined. Since the functions of most...... RNAs rely on interactions with proteins, the establishment of protein-binding profiles is essential for the characterization of RNAs. Aiming to facilitate RNA analysis, this thesis introduces proteomics- as well as transcriptomics-based methods for the functional characterization of RNA. First, RNA......-protein pulldown combined with mass spectrometry analysis is applied for in vivo as well as in vitro identification of RNA-binding proteins, the latter succeeding in verifying known RNA-protein interactions. Secondly, acknowledging the significance of flexible promoter usage for the diversification of the...

  6. Study on the use of neutron activation analysis within a new separation method in order to determine element traces in sea water

    Starting from the problematic situation of neutron activation analysis of sea salt it is outlined, that an early separation of disturbing nuclides of chief components will considerably increase the number of elements which can be determined by NAA of sea salt. Referring to this, a new separation method is presented which allows the selective separation of chief activities with the high decontamination factors required. For 21 elements limits of detection achieved by this method are compared with the average content of sea water. (orig.)

  7. A simple method of designing irradiation-, cooling-, and counting time in multi-element neutron activation analysis

    A method was investigated to seek the optimum irradiation-, cooling-, and counting time for economy of time, labor, and cost. For the first step, the terms of the basic equation of induction and decay of radioactivity were grouped into three parts: the terms of time, of proper values to each nuclide, and of variables due to experimental conditions. Then the equation was simplified by taking logarithm, and the values calculated from the equation for the terms of time and the characteristic values of each nuclide were tabulated. The counting time was decided in such a way that the counts of radioactivity of each nuclide fall in a range between minimal and maximal counts which were decided by counting statistics and by the dead time level of the measuring instruments. The calculation was made by simple treatment of the variables of the experimental conditions and of the values found in the prepared tables. An experimental scheme designed by the above method was applied to analysis of an atmospheric ''standard'' reference sample, and the analytical results were compared with those by the experimental scheme by R. Dams and with those obtained by three nuclear laboratories. The comparison showed that the present method made experiments economical in time, labor, and cost of the analysis by shortening the time of measurement to one half of those of R. Dams, leaving the accuracy almost in the same level. (auth.)

  8. Development of methods for the application of neutron activation analysis to the determination of trace elements in food

    For the determination of trace elements in foodstuffs with the aid of neutron activation analysis the separation of volatile radionuclides after digestion of the sample is of special interest for radiochemical processing. A distallation procedure was developed to give reproducable results, however optimal conditions were not found for all volatile radionuclides studied. The required selective separation of Br82 from the distillate was best achieved by the application of an ion-exchange column-chromatography technique. The computer programs for the evaluation of complex gamma spectra have been developed further. The automatic peak search and peak area determination is based on a computer program using the correlation technique and carried out with a mini-computer coupled with a multi-channel gamma spectrometer. The results, which are presented in 3 earlier reports relating to this research program, reveal the advantages and disadvantages of the individual steps of the radiochemical separation scheme. Before neutron activation analysis can be introduced on a routine basis, some aspects of the radiochemical process remain to be tested; these studies will be published in a fourth and final report. (orig.)

  9. An enzymatic deconjugation method for the analysis of small molecule active drugs on antibody-drug conjugates.

    Li, Yi; Gu, Christine; Gruenhagen, Jason; Yehl, Peter; Chetwyn, Nik P; Medley, Colin D

    2016-01-01

    Antibody-drug conjugates (ADCs) are complex therapeutic agents that use the specific targeting properties of antibodies and the highly potent cytotoxicity of small molecule drugs to selectively eliminate tumor cells while limiting the toxicity to normal healthy tissues. Two critical quality attributes of ADCs are the purity and stability of the active small molecule drug linked to the ADC, but these are difficult to assess once the drug is conjugated to the antibody. In this study, we report a enzyme deconjugation approach to cleave small molecule drugs from ADCs, which allows the drugs to be subsequently characterized by reversed-phase high performance liquid chromatography. The model ADC we used in this study utilizes a valine-citrulline linker that is designed to be sensitive to endoproteases after internalization by tumor cells. We screened several proteases to determine the most effective enzyme. Among the 3 cysteine proteases evaluated, papain had the best efficiency in cleaving the small molecule drug from the model ADC. The deconjugation conditions were further optimized to achieve complete cleavage of the small molecule drug. This papain deconjugation approach demonstrated excellent specificity and precision. The purity and stability of the active drug on an ADC drug product was evaluated and the major degradation products of the active drug were identified. The papain deconjugation method was also applied to several other ADCs, with the results suggesting it could be applied generally to ADCs containing a valine-citrulline linker. Our results indicate that the papain deconjugation method is a powerful tool for characterizing the active small molecule drug conjugated to an ADC, and may be useful in ensuring the product quality, efficacy and the safety of ADCs. PMID:26891281

  10. An Analysis on the Radioactivity Uncertainty Caused by Monte Carlo Stochastic Errors Using Sampling Based Method for the Accelerator Activation Problem

    In this study, to estimate the uncertainty caused by the MC stochastic error, the sampling based sensitivity and uncertainty method is introduced. After the estimation procedure was constructed, the activation analyses were performed for the βNMR (beta-radiation-detected Nuclear Magnetic Resonance) facility. In this study, procedure and program to analyze the activity uncertainty caused by stochastic error of MC method were developed. Using the flux and standard deviation information in MC transport output, 300 randomly sampled flux sets were produced to calculate the uncertainty. It is widely used to couple Monte Carlo (MC) transport code and activation code for the activation analysis of the accelerators. MC method is a stochastic approach for the particle transport; hence, the stochastic errors are always included in the MC transport results. Using the developed procedure, the air activation calculation in βNMR facility was performed. From the results, the major nuclide affected by the flux uncertainty was analyzed. Also, the guideline on the number of particle history is proposed to have a reliable result of the activation. The developed method and procedure will contribute to increasing the accuracy and reliability on the activation calculation

  11. Use of reference materials for validating analytical methods. Applied to the determination of As, Co, Na, Hg, Se and Fe using neutron activation analysis

    The main purpose of an analytical laboratory is to provide reliable information on the nature and composition of the materials submitted for analysis. This purpose can only be attained if analytical methodologies that have the attributes of accuracy, precision, specificity and sensitivity, among others, are used. The process by which these attributes are evaluated is called validation of the analytical method. The Chilean Nuclear Energy Commission's Neutron Activation Analysis Laboratory is applying a quality guarantee program to ensure the quality of its analytical results, which aims, as well, to attain accreditation for some of its measurements. Validation of the analytical methodologies used is an essential part of applying this program. There are many forms of validation, from comparison with reference techniques to participation in inter-comparison rounds. Certified reference materials were used in this work in order to validate the application of neutron activation analysis in determining As, Co, Na, Hg, Se and Fe in shellfish samples. The use of reference materials was chosen because it is a simple option that easily detects sources of systematic errors. Neutron activation analysis is an instrumental analytical method that does not need chemical treatment and that is based on processes which take place in the nuclei of atoms, making the matrix effects unimportant and different biological reference materials can be used. The following certified reference materials were used for validating the method used: BCR human hair 397, NRCC dogfish muscle DORM-2, NRCC -dogfish liver DOLT-2, NIST - oyster tissue 1566, NIES - mussel 6 and BCR - tuna fish 464. The reference materials were analyzed using the procedure developed for the shellfish samples and the above-mentioned elements were determined. With the results obtained, the parameters of accuracy, precision, detection limit, quantification limit and uncertainty associated with the method were determined for each

  12. Quantitative structure–activity relationship study of P2X7 receptor inhibitors using combination of principal component analysis and artificial intelligence methods

    Ahmadi, Mehdi; Shahlaei, Mohsen

    2015-01-01

    P2X7 antagonist activity for a set of 49 molecules of the P2X7 receptor antagonists, derivatives of purine, was modeled with the aid of chemometric and artificial intelligence techniques. The activity of these compounds was estimated by means of combination of principal component analysis (PCA), as a well-known data reduction method, genetic algorithm (GA), as a variable selection technique, and artificial neural network (ANN), as a non-linear modeling method. First, a linear regression, combined with PCA, (principal component regression) was operated to model the structure–activity relationships, and afterwards a combination of PCA and ANN algorithm was employed to accurately predict the biological activity of the P2X7 antagonist. PCA preserves as much of the information as possible contained in the original data set. Seven most important PC's to the studied activity were selected as the inputs of ANN box by an efficient variable selection method, GA. The best computational neural network model was a fully-connected, feed-forward model with 7−7−1 architecture. The developed ANN model was fully evaluated by different validation techniques, including internal and external validation, and chemical applicability domain. All validations showed that the constructed quantitative structure–activity relationship model suggested is robust and satisfactory. PMID:26600858

  13. Quantitative structure-activity relationship study of P2X7 receptor inhibitors using combination of principal component analysis and artificial intelligence methods.

    Ahmadi, Mehdi; Shahlaei, Mohsen

    2015-01-01

    P2X7 antagonist activity for a set of 49 molecules of the P2X7 receptor antagonists, derivatives of purine, was modeled with the aid of chemometric and artificial intelligence techniques. The activity of these compounds was estimated by means of combination of principal component analysis (PCA), as a well-known data reduction method, genetic algorithm (GA), as a variable selection technique, and artificial neural network (ANN), as a non-linear modeling method. First, a linear regression, combined with PCA, (principal component regression) was operated to model the structure-activity relationships, and afterwards a combination of PCA and ANN algorithm was employed to accurately predict the biological activity of the P2X7 antagonist. PCA preserves as much of the information as possible contained in the original data set. Seven most important PC's to the studied activity were selected as the inputs of ANN box by an efficient variable selection method, GA. The best computational neural network model was a fully-connected, feed-forward model with 7-7-1 architecture. The developed ANN model was fully evaluated by different validation techniques, including internal and external validation, and chemical applicability domain. All validations showed that the constructed quantitative structure-activity relationship model suggested is robust and satisfactory. PMID:26600858

  14. Optimization of instrumental neutron activation analysis method by means of 2{sup k} experimental design technique aiming the validation of analytical procedures

    Petroni, Robson; Moreira, Edson G., E-mail: rpetroni@ipen.br, E-mail: emoreira@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    In this study optimization of procedures and standardization of Instrumental Neutron Activation Analysis (INAA) methods were carried out for the determination of the elements arsenic, chromium, cobalt, iron, rubidium, scandium, selenium and zinc in biological materials. The aim is to validate the analytical methods for future accreditation at the National Institute of Metrology, Quality and Technology (INMETRO). The 2{sup k} experimental design was applied for evaluation of the individual contribution of selected variables of the analytical procedure in the final mass fraction result. Samples of Mussel Tissue Certified Reference Material and multi-element standards were analyzed considering the following variables: sample decay time, counting time and sample distance to detector. The standard multi-element concentration (comparator standard), mass of the sample and irradiation time were maintained constant in this procedure. By means of the statistical analysis and theoretical and experimental considerations it was determined the optimized experimental conditions for the analytical methods that will be adopted for the validation procedure of INAA methods in the Neutron Activation Analysis Laboratory (LAN) of the Research Reactor Center (CRPq) at the Nuclear and Energy Research Institute (IPEN - CNEN/SP). Optimized conditions were estimated based on the results of z-score tests, main effect and interaction effects. The results obtained with the different experimental configurations were evaluated for accuracy (precision and trueness) for each measurement. (author)

  15. Optimization of instrumental neutron activation analysis method by means of 2k experimental design technique aiming the validation of analytical procedures

    In this study optimization of procedures and standardization of Instrumental Neutron Activation Analysis (INAA) methods were carried out for the determination of the elements arsenic, chromium, cobalt, iron, rubidium, scandium, selenium and zinc in biological materials. The aim is to validate the analytical methods for future accreditation at the National Institute of Metrology, Quality and Technology (INMETRO). The 2k experimental design was applied for evaluation of the individual contribution of selected variables of the analytical procedure in the final mass fraction result. Samples of Mussel Tissue Certified Reference Material and multi-element standards were analyzed considering the following variables: sample decay time, counting time and sample distance to detector. The standard multi-element concentration (comparator standard), mass of the sample and irradiation time were maintained constant in this procedure. By means of the statistical analysis and theoretical and experimental considerations it was determined the optimized experimental conditions for the analytical methods that will be adopted for the validation procedure of INAA methods in the Neutron Activation Analysis Laboratory (LAN) of the Research Reactor Center (CRPq) at the Nuclear and Energy Research Institute (IPEN - CNEN/SP). Optimized conditions were estimated based on the results of z-score tests, main effect and interaction effects. The results obtained with the different experimental configurations were evaluated for accuracy (precision and trueness) for each measurement. (author)

  16. The Active Method of Teaching Foreign Languages

    Regina Juškienė

    2011-04-01

    Full Text Available The article discusses the active method of teaching foreign languages. It is considered to be the most effective means to teach foreign languages by increasing the efficiency of teaching foreign languages. The application of this method requires a good guide to the general concept of the human activity and deep analysis of its constituents. The preparation of the methodology for the active method of teaching foreign languages may benefit from the results of the analysis greatly. Since the number of hours for language teaching at non – philological higher school is limited, a selection of rational teaching subject must be carried out before the teaching process. Improved work is both theoretically and practically significant.

  17. Spatial and Temporal Analysis on the Distribution of Active Radio-Frequency Identification (RFID Tracking Accuracy with the Kriging Method

    Xin Liu

    2014-10-01

    Full Text Available Radio frequency identification (RFID technology has already been applied in a number of areas to facilitate the tracking process. However, the insufficient tracking accuracy of RFID is one of the problems that impedes its wider application. Previous studies focus on examining the accuracy of discrete points RFID, thereby leaving the tracking accuracy of the areas between the observed points unpredictable. In this study, spatial and temporal analysis is applied to interpolate the continuous distribution of RFID tracking accuracy based on the Kriging method. An implementation trial has been conducted in the loading and docking area in front of a warehouse to validate this approach. The results show that the weak signal area can be easily identified by the approach developed in the study. The optimum distance between two RFID readers and the effect of the sudden removal of readers are also presented by analysing the spatial and temporal variation of RFID tracking accuracy. This study reveals the correlation between the testing time and the stability of RFID tracking accuracy. Experimental results show that the proposed approach can be used to assist the RFID system setup process to increase tracking accuracy.

  18. A new method based on fractal variance function for analysis and quantification of sympathetic and vagal activity in variability of R-R time series in ECG signals

    Conte, Elio [Department of Pharmacology and Human Physiology and Tires, Center for Innovative Technologies for Signal Detection and Processing, University of Bari, Bari (Italy); School of Advanced International Studies on Nuclear, Theoretical and Nonlinear Methodologies-Bari (Italy)], E-mail: fisio2@fisiol.uniba.it; Federici, Antonio [Department of Pharmacology and Human Physiology and Tires, Center for Innovative Technologies for Signal Detection and Processing, University of Bari, Bari (Italy); Zbilut, Joseph P. [Department of Molecular Biophysics and Physiology, Rush University Medical Center, 1653W Congress, Chicago, IL 60612 (United States)

    2009-08-15

    It is known that R-R time series calculated from a recorded ECG, are strongly correlated to sympathetic and vagal regulation of the sinus pacemaker activity. In human physiology it is a crucial question to estimate such components with accuracy. Fourier analysis dominates still to day the data analysis efforts of such data ignoring that FFT is valid under some crucial restrictions that results largely violated in R-R time series data as linearity and stationarity. In order to go over such approach, we introduce a new method, called CZF. It is based on variogram analysis. It is aimed from a profound link with Recurrence Quantification Analysis that is a basic tool for investigation of non linear and non stationary time series. Therefore, a relevant feature of the method is that it finally may be applied also in cases of non linear and non stationary time series analysis. In addition, the method enables also to analyze the fractal variance function, the Generalized Fractal Dimension and, finally, the relative probability density function of the data. The CZF gives very satisfactory results. In the present paper it has been applied to direct experimental cases of normal subjects, patients with hypertension before and after therapy and in children under some different conditions of experimentation.

  19. A new method based on fractal variance function for analysis and quantification of sympathetic and vagal activity in variability of R-R time series in ECG signals

    It is known that R-R time series calculated from a recorded ECG, are strongly correlated to sympathetic and vagal regulation of the sinus pacemaker activity. In human physiology it is a crucial question to estimate such components with accuracy. Fourier analysis dominates still to day the data analysis efforts of such data ignoring that FFT is valid under some crucial restrictions that results largely violated in R-R time series data as linearity and stationarity. In order to go over such approach, we introduce a new method, called CZF. It is based on variogram analysis. It is aimed from a profound link with Recurrence Quantification Analysis that is a basic tool for investigation of non linear and non stationary time series. Therefore, a relevant feature of the method is that it finally may be applied also in cases of non linear and non stationary time series analysis. In addition, the method enables also to analyze the fractal variance function, the Generalized Fractal Dimension and, finally, the relative probability density function of the data. The CZF gives very satisfactory results. In the present paper it has been applied to direct experimental cases of normal subjects, patients with hypertension before and after therapy and in children under some different conditions of experimentation.

  20. Sacred activity by the Method of Excavation

    Eliana Anjos Furtado

    2014-04-01

    Full Text Available Excavation is a clinical and teaching methodology created by the first author of this article. It constitutes a way of helping subjects think, make and speak. This process occurs through the xcavation of making, unblinding and/or unveiling elements in search for the understanding of sacred activity. Through xcavation, subjects understand their thoughts, values and the society in which they live in as they excavate their life stories and their relations with making, including their daily, social and work activities. We applied a thoughtful analysis to approach the role of excavation and the concept of sacred activity. Sacred activity is the core activity of every human being, which is not necessarily the activity we perform in our everyday or work life. Sacred activity is that in which subjects are inserted and experience integrally, genuinely and with no masking. Through sacred activities, subjects surrender, not only to the activity itself, but also to the other, to himself and into himself, by quest. Seeking sacred activity is, therefore, a process of questioning, excavating the routine of subjects, watching and understanding the content of this excavation, replacing and adjusting what is being unveiled, and thus making this activity sacred. In this analysis, we concluded that, by the method of excavation, the sacralization of this action should allow subjects to have tender relationships, and thus be cured.

  1. Analysis of medicinal plant extracts by neutron activation method; Analise de extratos de plantas medicinais pelo metodo de ativacao com neutrons

    Vaz, Sandra Muntz

    1995-12-31

    This dissertation has presented the results from analysis of medicinal plant extracts using neutron activation method. Instrumental neutron activation analysis was applied to the determination of the elements Al, Br, Ca, Ce, Cl, Cr, Cs, Fe, K, La, Mg, Mn, Na, Rb, Sb, Sc and Zn in medicinal extracts obtained from Achyrolcline satureoides DC, Casearia sylvestris, Centella asiatica, Citrus aurantium L., Solano lycocarpum, Solidago microglossa, Stryphnondedron barbatiman and Zingiber officinale R. plants. The elements Hg and Se were determined using radiochemical separation by means of retention of Se in HMD inorganic exchanger and solvent extraction of Hg by bismuth diethyl-dithiocarbamate solution. Precision and accuracy of the results have been evaluated by analysing reference materials. The therapeutic action of some elements found in plant extracts analyzed was briefly discussed 70 refs., 13 figs., 15 tabs

  2. Implementation of the k0-standardization Method for an Instrumental Neutron Activation Analysis: Use-k0-IAEA Software as a Demonstration

    Under the RCA post-doctoral program, from May 2005 through February 2006, it was an opportunity to review the present work being carried out in the Neutron Activation Analysis Laboratory, HANARO Center, KAERI. The scope of this research included: a calibration of the counting system, a characterization of the irradiation facility ,a validation of the established ko-NAA procedure.The ko-standardization method for an Neutron Activation Analysis(ko-NAA), which is becoming increasingly popular and widespread,is an absolute calibration technique where the nuclear data are replaced by compound nuclear constants which are experimentally determined. The ko-IAEA software distributed by the IAEA in 2005 was used as a demonstration for this work. The NAA no. 3 irradiation hole in the HANARO research reactor and the gamma-ray spectrometers No. 1 and 5 in the NAA Laboratory were used

  3. Studies on application of neutron activation analysis -Applied research on air pollution monitoring and development of analytical method of environmental samples

    This research report is written for results of applied research on air pollution monitoring using instrumental neutron activation analysis. For identification and standardization of analytical method, 24 environmental samples are analyzed quantitatively, and accuracy and precision of this method are measured. Using airborne particulate matter and biomonitor chosen as environmental indicators, trace elemental concentrations of sample collected at urban and rural site monthly are determined ant then the calculation of statistics and the factor analysis are carried out for investigation of emission source. Facilities for NAA are installed in a new HANARO reactor, functional test is performed for routine operation. In addition, unified software code for NAA is developed to improve accuracy, precision and abilities of analytical processes. (author). 103 refs., 61 tabs., 19 figs

  4. Instrumental neutron activation analysis of geochemical samples by k{sub 0} standardization method using short lived nuclides

    Oura, Yasuji; Kanzaki, Chinatsu; Ebihara, Mitsuru [Tokyo Metropolitan Univ., Graduate School of Science, Tokyo (Japan)

    2003-03-01

    Mg, Al, Ca, Ti, V, and Mn contents in geochemical and cosmochemical samples were analyzed by both k{sub 0} standardization INAA and conventional INAA by a comparison method. The contents of Mg, Al, and Mn by k{sub 0} method were consistent with recommended values and ones by comparison methods. For Ti and V their values are slightly higher than recommended ones. The values by k{sub 0} method were reliable within {+-}10%. (author)

  5. Determination of 60 Co by means of Neutron Activation Analysis in the sorption of Co in synthesized porous oxides by the combustion method

    Recently inorganic materials are investigating as sorbent of radioactive pollutants present in water. The inorganic oxides belong to this group of materials. A quick method exists for the obtaining of inorganic oxides, denominated combustion method that could be used to produce porous oxides successfully with good properties for the sorption of radioactive ions. In this investigation, iron oxides, magnesium and zinc were synthesized obtained by the combustion method, comparing them with those synthesized by the calcination method, using two different synthesis temperatures. The obtained solids were characterized by scanning electron microscopy (Sem), by X-ray diffraction (XRD) and by semiquantitative elemental analysis (EDS). After the characterization, the crystalline oxides synthesized by both methods, to temperature of 800 C, were evaluated as sorbents in the removal of Co2+ ions, through experiments in batch, and using neutron activation analysis, determining the sorption percentage, with this it was concluded that the magnesium oxide produced by combustion it is more effective in the removal of Co2+ ions than that synthesized by calcination. It was determined the surface area of the magnesium oxides, obtaining a surface area greater for the synthesized oxide by combustion method. (Author)

  6. USE OF STATISTICAL METHODS IN DETECTING ACCOUNTING ENGINEERING ACTIVITIES (AS EXEMPLIFIED BY THE ACCOUNTING SYSTEM IN POLAND – SECOND PART: EMPIRICAL ASPECTS OF ANALYSIS

    Leszek Michalczyk

    2013-10-01

    Full Text Available This article is one in a series of two publications concerning detection of accounting engineering operations in use. Its conclusions and methods may be applied to external auditing procedures. The aim of the present duo-article is to define a method of statistical analysis that could identify procedures falling within the scope of a framework herein defined as accounting engineering. This model for analysis is meant to be employed in these aspects of initial financial and accounting audit in a business enterprise that have to do with isolating the influence of variant accounting solutions, which are a consequence of the settlement method chosen by the enterprise. Materials for statistical analysis were divided into groups according to the field in which a given company operated. In this article, we accept and elaborate on the premise that significant differences in financial results may be solely a result of either expansive policy on new markets or the acquisition of cheaper sources for operating activities. In the remaining cases, the choice of valuation and settlement methods becomes crucial; the greater the deviations, the more essential this choice becomes. Even though the research materials we analyze are regionally-conditioned, the model may find its application in other accounting systems, provided that it has been appropriately implemented. Furthermore, the article defines an innovative concept of variant accounting.

  7. Conference on instrumental activation analysis - IAA 89

    The proceedings contain 40 abstracts of papers all of which have been incorporated in INIS. The papers were centred on the applications of radioanalytical methods, especialy on neutron activation analysis, X-ray fluorescence analysis, PIXE analysis and tracer techniques in biology, medicine and metallurgy, measuring instruments including microcomputers, and data processing methods. (J.P.)

  8. Conference on Instrumental Activation Analysis: IAA 89

    Vobecky, M.; Obrusnik, I.

    1989-05-01

    The proceedings contain 40 abstracts of papers all of which have been incorporated in INIS. The papers were centred on the applications of radioanalytical methods, especially on neutron activation analysis, x ray fluorescence analysis, PIXE analysis and tracer techniques in biology, medicine and metallurgy, measuring instruments including microcomputers, and data processing methods.

  9. The chemical speciation and analysis of trace elements in sediment with Neutron Activation Analytical method(NAA) and atomic mass spectrometry

    In this research, first of all, the analytical methods for the determination of major elements in sediment have been developed with ICP-MS (Inductively Coupled Plasma Mass Spectrometry). The analytical results of major elements (Al, Ca, K, Fe, Mg) with Cool ICP-MS were much better than those with normal ICP-MS. The analytical results were compared with those of NAA (Neutron Activation Analysis). NAA were a little superior to ICP-MS for the determination of major elements in sediment as a non-destructive trace analytical trace analytical method. The analytical methods for the determination of minor elements (Cr, Ce, U, Co, Pb, As, Se) have been also developed with ICP-MS. The analytical results by standard calibration curve with ICP-MS were not accurate due to the matrix interferences. Thus, the internal standard method was applied, then the analytical results for minor elements with ICP-MS were greatly improved. The analytical results obtained by ICP-MS were compared with those obtained by NAA. It showed that the two analytical methods have great capabilities for the determination of minor elements in sediments. Accordingly, the NAA will plan an important role in analysis of environment sample with complex matrix. ICP-MS also will play an important role because it has a great capability for the determination of Pb that could not be determined by NAA

  10. Communication Network Analysis Methods.

    Farace, Richard V.; Mabee, Timothy

    This paper reviews a variety of analytic procedures that can be applied to network data, discussing the assumptions and usefulness of each procedure when applied to the complexity of human communication. Special attention is paid to the network properties measured or implied by each procedure. Factor analysis and multidimensional scaling are among…

  11. Comparative analysis of selected methods for the assessment of antimicrobial and membrane-permeabilizing activity: a case study for lactoferricin derived peptides

    Lohner Karl

    2008-11-01

    Full Text Available Abstract Background Growing concerns about bacterial resistance to antibiotics have prompted the development of alternative therapies like those based on cationic antimicrobial peptides (APs. These compounds not only are bactericidal by themselves but also enhance the activity of antibiotics. Studies focused on the systematic characterization of APs are hampered by the lack of standard guidelines for testing these compounds. We investigated whether the information provided by methods commonly used for the biological characterization of APs is comparable, as it is often assumed. For this purpose, we determined the bacteriostatic, bactericidal, and permeability-increasing activity of synthetic peptides (n = 57; 9–13 amino acid residues in length analogous to the lipopolysaccharide-binding region of human lactoferricin by a number of the most frequently used methods and carried out a comparative analysis. Results While the minimum inhibitory concentration determined by an automated turbidimetry-based system (Bioscreen or by conventional broth microdilution methods did not differ significantly, bactericidal activity measured under static conditions in a low-ionic strength solvent resulted in a vast overestimation of antimicrobial activity. Under these conditions the degree of antagonism between the peptides and the divalent cations differed greatly depending on the bacterial strain tested. In contrast, the bioactivity of peptides was not affected by the type of plasticware (polypropylene vs. polystyrene. Susceptibility testing of APs using cation adjusted Mueller-Hinton was the most stringent screening method, although it may overlook potentially interesting peptides. Permeability assays based on sensitization to hydrophobic antibiotics provided overall information analogous – though not quantitatively comparable- to that of tests based on the uptake of hydrophobic fluorescent probes. Conclusion We demonstrate that subtle changes in methods for

  12. Charged-particle activation analysis

    The paper discusses the methodology and application of nuclear activation with ion beams (19 via 16O(3He,p)18F, 12C(3He,α)11C and 14N(p,α)11C respectively. Recently, triton activation has been shown to be inherently still superior to 3He activation for the determination of oxygen [16O(3H,n)18F]. Lithium, boron, carbon and sulphur can be detected rapidly, nondestructively and with high sensitivity (approximately 0.25ppm for Li and B) via ''quasi-prompt'' activation based on the detection of short-lived, high-energy beta emitters (10ms1H(7Li,n)7Be for example. Nondestructive multielement analysis: Proton activation has the inherent potential for meeting requirements of broad elemental coverage, sensitivity (ppm and sub-ppm range) and selectivity. Up to 30 elements have been determined in Al, Co, Ag, Nb, Rh, Ta and biological samples, using 12-MeV proton activation followed by gamma-ray spectrometry. These capabilities are further enhanced with the counting of X-ray emitters, 28 elements (269) and accuracy using proton activation. 204Pb/206Pb ratios can also be determined with a relative precision of a few per cent. Although charged-particle activation analysis is a well-established trace analysis technique, broad potential capabilities remain to be explored, e.g. those arising from ultrashort-lived nuclides, heavy ion interactions and the combination of delayed and prompt methods. (author)

  13. Development of the Method of Bacterial Leaching of Metals out of Low-Grade Ores, Rocks, and Industrial Wastes Using Neutron Activation Analysis

    Tsertsvadze, L A; Petriashvili, Sh G; Chutkerashvili, D G; Kirkesali, E I; Frontasyeva, M V; Pavlov, S S; Gundorina, S F

    2001-01-01

    The results of preliminary investigations aimed at the development of an economical and easy to apply technique of bacterial leaching of rare and valuable metals out of low-grade ores, complex composition ores, rocks, and industrial wastes in Georgia are discussed. The main groups of microbiological community of the peat suspension used in the experiments of bacterial leaching are investigated and the activity of particular microorganisms in the leaching of probes with different mineral compositions is assessed. The element composition of the primary and processed samples was investigated by the epithermal neutron activation analysis method and the enrichment/subtraction level is estimated for various elements. The efficiency of the developed technique to purify wastes, extract some scrace metals, and enrich ores or rocks in some elements, e.g. Au, U, Th, Cs, Sr, Rb, Sc, Zr, Hf, Ta, Gd, Er, Lu, Ce, etc., is demonstrated.

  14. Method of rare earths determination, with separation pre-irradiation followed by neutron activation analysis. Using of brazilian standards BB-1 and GB-1

    In order to determine the rare earth elements (REE) in rocks, by neutron activation analysis, a group separation, before irradiation, was developed. The brazilian geological standards BB-1 and GB-1, provided by Instituto de Geociencias da Universidade da Bahia, were analyzed. The method was based an acid digestion of the samples, cation exchange separation with a Dowex 50WX8 column and coprecipitation of the REE with calcium oxalate. Interferers like U, Th, Ta and Fe were eliminated. The concentration values of ten REE (La, Ce, Pr, Nd, Sm, Eu, Tb, Ho, Yb and Lu) were determined. The analysis of Pr brought a contribution to the knowledge of the REE contents in these geological standards, since there are not yet results in the literature. The other REE data obtained were compared with literature values and some discrepancies are discussed. (author)

  15. Contribution of Italy to the activities on intercomparison of analysis methods for seismically isolated nuclear structures: Shake table tests on a steel frame structure mock-up

    This report describes a series of tests performed during a wide ranging experimental campaign on a steel frame structure mock-up subjected to shake table excitations, in both fixed and base isolated configurations. Preliminary numerical simulations of experimental results, carried out by the ENEA and ENEL, are also reported. The main features of a simplified model of rubber bearings, developed and proposed by ENEA and ENEL, used in the above mentioned numerical analysis, are presented together with example of validations. Activities are being carried out in the framework of the four years' Co-ordinated Research Programme (CRP) of the International Atomic Energy Agency (IAEA) on Intercomparison of Analysis Methods for Seismically Isolated Nuclear Structures. (author)

  16. COMPETITIVE INTELLIGENCE ANALYSIS - SCENARIOS METHOD

    Ivan Valeriu

    2014-07-01

    Full Text Available Keeping a company in the top performing players in the relevant market depends not only on its ability to develop continually, sustainably and balanced, to the standards set by the customer and competition, but also on the ability to protect its strategic information and to know in advance the strategic information of the competition. In addition, given that economic markets, regardless of their profile, enable interconnection not only among domestic companies, but also between domestic companies and foreign companies, the issue of economic competition moves from the national economies to the field of interest of regional and international economic organizations. The stakes for each economic player is to keep ahead of the competition and to be always prepared to face market challenges. Therefore, it needs to know as early as possible, how to react to others’ strategy in terms of research, production and sales. If a competitor is planning to produce more and cheaper, then it must be prepared to counteract quickly this movement. Competitive intelligence helps to evaluate the capabilities of competitors in the market, legally and ethically, and to develop response strategies. One of the main goals of the competitive intelligence is to acknowledge the role of early warning and prevention of surprises that could have a major impact on the market share, reputation, turnover and profitability in the medium and long term of a company. This paper presents some aspects of competitive intelligence, mainly in terms of information analysis and intelligence generation. Presentation is theoretical and addresses a structured method of information analysis - scenarios method – in a version that combines several types of analysis in order to reveal some interconnecting aspects of the factors governing the activity of a company.

  17. In vivo radioactive metabolite analysis for individualized medicine: A basic study of a new method of CYP activity assay using 123I-IMP

    Introduction: 123I-N-isopropyl-p-iodoamphetamine (123I-IMP) is metabolized and converted to 123I-p-iodoamphetamine (123I-PIA) by CYP2C19 in humans. Since variations in 123I-PIA levels reflect variations in CYP2C19 activity, CYP2C19 activity can be estimated by quantitative analysis of 123I-PIA levels. Thus, 123I-IMP administration can provide diagnostic information not only regarding cerebral blood flow (rCBF) but also regarding metabolic function. The aim of the present study was to detect variations in CYP activity in mice using metabolite analysis. Methods: Metabolism of 125I-IMP in pooled homogenates of mouse liver (MLH) was analyzed by high-performance liquid chromatography (HPLC) in the presence or absence of NADPH. The amount of 125I-PIA generated was calculated as the normalized peak area of the chromatogram. Inhibition of 125I-IMP metabolism was evaluated using the inhibitor SKF-525A. A biodistribution study of 125I-IMP was performed to determine the organ distribution of 125I-IMP/125I-IMP metabolites and the effect of SKF-525A. Variations in CYP activity in vivo were detected by administration of 123I-IMP and/or SKF-525A to mice. The liver and the kidney were then excised, homogenized and analyzed using HPLC. Results: 125I-IMP was metabolized by MLH in the presence of NADPH, and the production of 125I-PIA was inhibited by SKF-525A. SKF-525A did not greatly affect the biodistribution of 125I-IMP/125I-IMP metabolites in vivo. Both 123I-IMP and 123I-PIA were detected in organs of control mice. However, 123I-PIA was not detected in the livers or kidneys of mice treated with SKF-525A. Conclusions: CYP activity in vivo was inhibited by SKF-525A treatment. Variations in CYP activity could be detected in the blood, liver and kidney as changes in the peak area of 123I-PIA. Advances in knowledge and implications for patient care: 123I-IMP metabolite analysis has the potential to provide beneficial information for prediction of the effect of medicines, in addition

  18. The application and development of k0-standardization method of neutron activation analysis at Dalat research reactor

    In recent years the k0-NAA method has been applied and developed at the 500 kW Dalat research reactor, which includes the establishment of a PC database of k0-NAA-related nuclear parameters, e.g., radionuclide produced, half-lives, k0-factors, Q0, E-barr Eγ, etc; the access to the database is able by a k0-NAA software or by manual; the detection efficiency calibration of gamma spectrometers used in k0-NAA, the determination of reactor neutron spectrum parameters such as α and f factors and neutron fluxes in the irradiation channels, and the validation of the developed k0-NAA procedure by analysing some SRMs, namely Coal Fly Ash (NIST-1633b), Bovine Liver (NIST-1577b) and IAEA-Soil7. The analytical results showed the deviations between experimental and certified values were mostly less than 15% with most Z-scores lower than 2. The k0-NAA procedure established at the Dalat research reactor has been regarded as a reliable standardization method of NAA and as available for practical applications, in particularly for airborne particulate and crude oil samples. (author)

  19. Development of RP-HPLC method for Qualitative Analysis of Active Ingredient (Gallic acid from Stem Bark of Dendrophthoe falcate Linn.

    Hafsa Deshmukh

    2011-04-01

    Full Text Available A simple, precise and sensitive, RP-HPLC method with UV detection at 271nm was developed and validated for qualitative determination of active ingredient Gallic acid from stem bark of Dendrophthoe falcate Linn. Separation was performed on a ThermoMOS 2 HYPERSIL C18 column (250 cm × 4.6 mm, 5µm ODS 3 using mobile phase comprising of 0.1% Orthophosphoric acid : Acetonitrile (400 cm3 : 600 cm3 with a flow rate of 1 ml/minute with a short run time of 13 minute. The method was validated according to the regulatory guidelines with respect to linearity, system suitability, precision, solution stability, accuracy, robustness, assay and recovery. Detector response was linear for HPLC in the range of 0.04 to 0.16 mg/cm3. The system suitability, precision, solution stability, accuracy, robustness, assay and recovery was assessed by calculating % COV for all these parameters which is less than two as expected. The recovery of the method for Gallic acid was found 98.94% which shows that method is accurate. The described method has the advantage of being rapid and easy hence it can be applied for routine quality control analysis of Gallic acid from Dendrophthoe falcate Linn.

  20. Firm Analysis by Different Methods

    Píbilová, Kateřina

    2012-01-01

    This Diploma Thesis deals with an analysis of the company made by selected methods. External environment of the company is analysed using PESTLE analysis and Porter’s five-factor model. The internal environment is analysed by means of Kralicek Quick test and Fundamental analysis. SWOT analysis represents opportunities and threats of the external environment with the strengths and weaknesses of the company. The proposal of betterment of the company’s economic management is designed on the basi...

  1. Method Dynamics: An Analysis of the Effect of Activity-Based Instruction on the Persistent Misconceptions of Physics Students

    Markes, Mark; Reiser, Emily

    2004-05-01

    Studies have indicated that student misconceptions negatively impact the effectiveness of physics education. Research has also shown that activity based instruction (ABI) has greater effectiveness than lecture based instruction (LBI) in many applications. This paper examines the effect of ABI on the persistent misconceptions of physics students. A persistent misconception is defined for an LBI student as identical wrong answers on pre and posttests, using the Force and Motion Concept Evaluation. To evaluate the effect of ABI on persistent misconceptions, pretest and posttest responses were divided into wrong to same wrong (ww), wrong to different wrong (ww'), and wrong to right (wr). The effect of ABI was modeled as a transfer of probability among these three response groups. Results indicate that ABI obtains about equal gains from the ww' and ww groups with the transfer from ww to ww' small in comparison. This indicates that ABI is about equally effective with students who have persistent misconceptions and students who do not have persistent misconceptions.

  2. Determination of toxic and trace elements in human hair and sediment samples by reactor neutron activation analysis technique based-on the k-zero method

    The analysis of human hair can evaluate the degree of environmental pollutants exposure to human body, intakes of food and metabolism. Also, the analysis of sediment can aid in reconstructing the history of changes, understanding human impact on the ecosystem, and suggesting possible remedial strategies. The ko-standardization method of neutron activation analysis (ko-NAA) on research reactor is capable to play an important role as a main analytical technique with the advantages of sensitivity, precision, accuracy, multielement and routine for the sample object. Therefore, the project's aim is to build the ko-NAA procedures on the Dalat research reactor for the analysis of human hair and sediment samples. The Ko-NAA procedure on the Dalat research reactor is able to determine of multielement: Ag, Al, As, Br, Ca, Cl, Co, Cr, Cu, Fe, Hg, I, K Mg, Mn, Na, S, Sb, Se, Sr, Ti, V and Zn in The human hair; and of multielement: As, Co, Cr, Cs, Fe, Hf, K, La, Mn, Na Rb, Sb, Sc, Yb and Zn in the sediment. (author)

  3. Study on photon activation analysis of carbon in glasses for fiber amplifiers by using the flow method for the rapid separation of 11C

    We have studied nuclear interference from a matrix produced by (γ, n), (γ, 2n), (γ, p) and (n, γ) reactions and a flow method for 11C separation in order to develop an approach for the photon activation analysis of carbon in InF3-based fluoride, chalcogenide and tellurite glasses for fiber amplifiers. We found that seventeen radionuclides are produced from these glasses and chemical separation is necessary to determine carbon. For the flow method, which involves the fusion of an irradiated sample with an oxidizer, the conversion of 11C into 11CO2 and the absorption of 11C in ethanolamine solution, we used a mixture of Pb3O4 and B2O3 as the oxidizer. We also found that the reaction between 19F(γ, n) and 23Na(γ, αn) in the ethanolamine solution produced 18F contamination with fluoride and chalcogenide glasses and that this flow method can only be applied to tellurite glasses. We confirmed that the chemical yield of the flow method was close to 100% when determining carbon in standard steel samples by using lithium carbonate as a standard sample. We determined that the carbon concentrations in two kinds of tellurite glass were 8 to 13 and 21 to 28 ppm, respectively. (author)

  4. Activation analysis in forensic studies

    Application of neutron activation analysis in forensics are grouped into 3 categories: firearms-discharge applications, elemental analysis of other nonbiological evidence materials (paint, other), and elemental analysis of biological evidence materials (multielemental analysis of hair, analysis of hair for As and Hg). 18 refs

  5. Probabilistic methods for rotordynamics analysis

    Wu, Y.-T.; Torng, T. Y.; Millwater, H. R.; Fossum, A. F.; Rheinfurth, M. H.

    1991-01-01

    This paper summarizes the development of the methods and a computer program to compute the probability of instability of dynamic systems that can be represented by a system of second-order ordinary linear differential equations. Two instability criteria based upon the eigenvalues or Routh-Hurwitz test functions are investigated. Computational methods based on a fast probability integration concept and an efficient adaptive importance sampling method are proposed to perform efficient probabilistic analysis. A numerical example is provided to demonstrate the methods.

  6. A new method based on low background instrumental neutron activation analysis for major, trace and ultra-trace element determination in atmospheric mineral dust from polar ice cores.

    Baccolo, Giovanni; Clemenza, Massimiliano; Delmonte, Barbara; Maffezzoli, Niccolò; Nastasi, Massimiliano; Previtali, Ezio; Prata, Michele; Salvini, Andrea; Maggi, Valter

    2016-05-30

    Dust found in polar ice core samples present extremely low concentrations, in addition the availability of such samples is usually strictly limited. For these reasons the chemical and physical analysis of polar ice cores is an analytical challenge. In this work a new method based on low background instrumental neutron activation analysis (LB-INAA) for the multi-elemental characterization of the insoluble fraction of dust from polar ice cores is presented. Thanks to an accurate selection of the most proper materials and procedures it was possible to reach unprecedented analytical performances, suitable for ice core analyses. The method was applied to Antarctic ice core samples. Five samples of atmospheric dust (μg size) from ice sections of the Antarctic Talos Dome ice core were prepared and analyzed. A set of 37 elements was quantified, spanning from all the major elements (Na, Mg, Al, Si, K, Ca, Ti, Mn and Fe) to trace ones, including 10 (La, Ce, Nd, Sm, Eu, Tb, Ho, Tm, Yb and Lu) of the 14 natural occurring lanthanides. The detection limits are in the range of 10(-13)-10(-6) g, improving previous results of 1-3 orders of magnitude depending on the element; uncertainties lies between 4% and 60%. PMID:27154827

  7. Determining the amount of Br, Na and K in six wheat samples with neutron activation analysis (NAA) method in Arak, I.R. Iran

    Accurate knowledge of the trace elemental concentrations in wheat and its products is of great importance from a nutritional point of view. In this study, six wheat samples were prepared from the agriculture research center of Arak named Sardari, Amir, MV-17, Batava, Karaj-2 and Alvand; they were analyzed by neutron activation method (NAA). In this method, Isfahan miniature reactor as a neutron source and relative NAA method has been used as the analysis type. In this design in order to record gamma spectrum the MCA system and high purity germanium detector were used. Finally, the concentration of the trace elements such as Br, K and Na value was determined for the Sardari, Amir, Alvand, MV-17, Batava, Karaj-2 wheat samples. The average concentration of trace elements in all wheat samples in the studied area are 2.41(0.8597-6.1175) mg kg-1 for Br, 13.42(8.7063-24.696) mg kg-1 for Na and 463.30(434.22-505.45) mg kg-1 for K, respectively. These were compared with other reports results. This study has been conducted as the first time for this region. (author)

  8. Optimization of instrumental activation analysis

    Activation analysis is one of the most well-understood methods available to the analyst. It should, therefore, be possible to infer, from prior information about the sample, what procedure should be followed in its analysis. The accuracy of this process is naturally limited by the extent and accuracy of the prior information available. Better results should be obtained in this way, however, than by ignoring prior information. It is the task of optimization to discover the analytical procedure that best suits the sample being analyzed. Optimization can be conveniently conceptualized if each experimental parameter is considered as a dimension of a geometric space. In activation analysis, if only irradiation and decay times are to be adjusted, the parameter space will be two dimensional. Each point in the parameter space corresponds to a possible procedure for carrying out a determination and each such procedure will perform more or less satisfactorily than others. Optimization, then, consists of a search for a point or a region in parameter space where performance meets the analyst's requirements. Practicality is an important consideration in designing a procedure for activation analysis. There are limits to the amount of radioactive material that can be handled safely and to the count rate that be accurately measured. Circumstances often impose further limits. It is, therefore, necessary to constrain the search of parameter space to those regions that correspond to practical procedures. In attempting an optimization, one must consider a number of aspects. A set of experimental parameters must be chosen for adjustment and others set at fixed values, often due to practical constraints. The way in which quality of analytical performance (the response function) is to be evaluated must be decided. A means of locating the optimum must be chosen and, finally, this optimization scheme must be implemented in a practical, convenient manner. These aspects are discussed

  9. Activation analysis in science and technics

    Physical bases of the method of neutron activation analysis are described. Reactions of element nuclei with neutrons, gamma quanta and charged particles, ways of radioactivity measurement, gamma spectrometry in particular, have been described. The method errors, as well as element determination sensitivity in samples of different composition are considered, perspectives of activation analysis development being reflected. The practical use of the method in the studies on solid-state physics, during the analysis of semiconductors and pure materials, in criminalistics, agriculture, the environmnental control in geology and biology, is shown

  10. Comparison of 14 MeV neutron activation analysis and competitive methods for determination of oxygen, nitrogen, silicon, fluorine and other elements

    14 MeV neutron activation analysis (14 MeV NAA) makes use of small particle accelerators to produce 14 MeV neutrons from the D-T reaction. The neutrons produce radioactive isotopes in samples by the reactions (n,p), (n,2n) and (n,α). Gamma rays emitted are counted to determine the amount of the target element present. Major applications have been determination of total O, N or Si in solid and liquid matrices, but the technique can also be applied to determine concentrations of about 30 other elements including F, Cl, Al, P and Mg. Detection limits are a few micrograms in the best cases and milligrams for most others. The method has advantages of being nondestructive, fast and insensitive to sample inhomogeneities. It lends itself especially well to sequential analysis of the same sample by several techniques and to samples that are difficult to dissolve. Portable generators have been applied to industrial situations and to well logging. Major disadvantages are the necessity to house a radiation producing instrument, the cost of the equipment and the lack of useful neutron reactions for some important elements. Accuracy (typically +-1 to 10% relative) and precision (+-1 to 5% relative) are comparable to competing techniques. For determination of low levels of O and N in most metals inert gas fusion is more rapid and sensitive; elemental analyzer is more sensitive for O and N in organics. Wet chemical methods rarely have any advantage over 14 MeV NAA for solid samples when concentrations are in the detection limit range of the 14 MeV NAA methods. Future developments in the field will come in the areas of simpler, more portable and higher neutron output generator designs. (author). 66 refs

  11. Neutron activation analysis of biological substances

    A Bowen cabbage sample was used as a reference material for the neutron activation studies, and the method was checked by the analysis of other biological substances (blood or serum etc.). For nondestructive measurements also some non-trace elements were determined in order to decide whether the activation analysis is a useful means for such measurements. The new activation analysis procedure was used for biomedical studies as, e.g., for trace element determination in body fluids, and for the analysis of inorganic components in air samples. (R.P.)

  12. Comparison of two semi-absolute methods. k{sub 0}-instrumental neutron activation analysis and fundamental parameter method X-ray fluorescence spectrometry for Ni-based alloys

    Wasim, Mohammad [Pakistan Institute of Nuclear Science and Technology, Islamabad (Pakistan). Chemistry Div.; Ahmad, Sajjad [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Chemistry

    2015-07-01

    Nickel based alloys play important role in nuclear, mechanical and chemical industry. Two semi-absolute standardless methods, k{sub 0}-instrumental neutron activation analysis (k{sub 0}-INAA) and fundamental parameter X-ray fluorescence spectrometry (FP-XRF) were used for the characterization of certified nickel based alloys. The optimized experimental conditions for NAA provided results for 18 and XRF for 15 elements. Both techniques were unable to quantify some important alloy making elements. However, both reported results of other elements as information values. The techniques were analyzed for their sensitivity and accuracy. Sensitivity was evaluated by the number of elements determined by each technique. Accuracy was ascertained by using the linear regression analysis and the average root mean squared error.

  13. New method to measure oxygen isotopic concentration ratios 18O/16O by gamma-activation analysis, especially in biological media

    Two photonuclear reactions were used for this isotopic analysis: 16O(γ,n)15O (threshold energy 15.7 MeV) and 18O(γ,p)17N (threshold energy 16.3 MeV). 15O is a pure β+ emitter of half-life 2.03 minutes, whereas 17N presents a 4.2 second neutron emission. A scintillation probe equipped with a sodium iodide crystal detects the 15O positron annihilation γ-rays. The 17N neutron activity is recorded with BF3 type counters. The potentialities of this new oxygen isotope analysis method using an electron accelerator, are described. Detection limit of 0.1 μg 18O is easily attainable. The equipment designed and built to industrialize this technique is described. The measurement system is connected by a fast pneumatic circuit to the irradiation device set up at the outlet of the accelerator. The flow-sheet of the apparatus is shown. A central electronic control unit commands, according to a pre-set time table, the linear accelerator, the sample loader, the pneumatic circuits and the counting instruments. It allows a hundred samples to be analysed automatically, the accelerator, detection instruments and pneumatic transfer circuits being controlled by a logic system linked to an electronic chronometer. (T.G.)

  14. Determination of concentrations of minor and micro elements in ancient bronze drums artifacts samples by KO-standardization method of neutron activation analysis

    The study aims to get a lot information about manufacturers of ancient bronze artifacts and ancient civilization. By KO-standardization method of neutron activation analysis developed in the Nuclear Research Institute, the concentrations of Au, Ag, As, Zn, Sb, Sn elements in ancient bronze alloy samples of 99 bronze artifacts from many excavated archaeological sites at the provinces in Vietnam were determined with uncertainties about ±10%. These elemental concentrations have been utilized in a statistical analysis procedure in order to determine similarities and correlation between the various samples. Th abnormal high of concentrations of noble metals as Au, Ag in ancient bronze indicates that the ancient metallurgists had been interested in role of these metals on sound quality of bronze artifacts. Especially, the concentrations of As in many samples are very high even at about 10%. This gives an evidence that in ancient time the humankind could use bronze As alloy in order to improve quality when they had produced bronze artifacts. (author)

  15. Fish sampling with active methods

    Kubečka, Jan; Godo, O. R.; Hickley, P.; Prchalová, Marie; Říha, Milan; Rudstam, L.; Welcomme, R.

    2012-01-01

    Roč. 123, July (2012), s. 1-3. ISSN 0165-7836 Institutional support: RVO:60077344 Keywords : fish stock assessment * active and passive gear * intercalibration Subject RIV: EH - Ecology, Behaviour Impact factor: 1.695, year: 2012

  16. Determination of trace elements in scallop and fish otolith by instrumental neutron activation analysis using anti-coincidence and coincidence counting methods

    Trace element concentrations in scallop reference material and fish otolith certified reference materials prepared at the National Institute for Environmental Studies (NIES) of Japan were determined by instrumental neutron activation analysis (INAA). Nine aliquots of scallop sample (ca. 252∼507 mg) and five aliquots of fish otolith sample (ca. 502 ∼ 988 mg) and comparative standards were irradiated for a short time (10 s) at a thermal neutron flux of 1.5 x 1012 n cm-2s-1 (pneumatic transfer) and for a long time (6 h) at a thermal neutron flux of 3.7 x 1012n cm-2s-1 (central thimble) in the Rikkyo University Research Reactor (100 kW). The irradiated samples were measured by conventional γ-ray spectrometry using a coaxial Ge detector, and by anti-coincidence and coincidence γ-ray spectrometry with a coaxial Ge detector and a well-type NaI (Tl) detector to determine as many trace elements as possible with high sensitivity. The concentrations of 34 elements of the NIES No.15 scallop reference material and 16 elements of the NIES No.22 fish otolith CRM were determined. Using the coincidence counting method to determine Se, Ba and Hf, the lower limit of the determination was improved by 2 times compared with the conventional counting method. (author)

  17. Devising of the method for the determination of small and very small amounts of cadmium in biological materials by radiochemical version of neutron activation analysis

    The newly modified version of the method for the determination of cadmium in biological materials by radiochemical NAA based on selective post irradiation separation of Cd using ion exchange rasin Retardion 11A8 is presented. The conditions necessary for the selective retaining of Cd on the column exploiting both anionic and cationic ion exchange function of the resin have been discussed. Depending on the composition of the external solution, cadmium existing in the form of either anionic chloride complexes or cationic amine species is taken up by quaternary ammonium or carboxylate functional groups, respectively while accompanying elements are eluted. The elaborated method was further verified by determine Cd content in several certified biological reference materials using neutron activation analysis. The ion exchange separation procedure assures very high radiochemical purity of the cadmium fraction. Decontamination factors obtained for Mo, Sb, Na, Zn, Co, Sc amounted to 103 - 106. Detection limit for Cd was 0.5 μg kg-1. Analytical results show good agreement with the certified values. (author). 10 refs, 7 figs, 1 tab

  18. Study on the dynamics of halogen elements in the agro-environment and these element`s deficiency, toxicity and environmental hazards by the application of the neutron activation analysis method

    Yuita, Kouichi [National Inst. of Agro-Environmental Sciences, Tsukuba, Ibaraki (Japan)

    1998-03-01

    A neutron activation analysis method is an accurate and highly sensitive method for analyzing halogen elements (iodine, bromine and chlorine) except fluorine. It is unsubstitutable and valuable method especially for iodine (including radioactive {sup 129}I) and bromine which are present at lower levels. Halogen elements have high chemical and physiological activities and move widely in the environment. As a result, deficiency and an excess of halogen elements in plants and animals have occurred and artificial halogen compounds have caused environmental pollution in wide areas. We efficiently utilized the neutron activation analysis method and an activable tracer method to obtain valuable findings which contribute to the clarification of and measures against these actual problems and which are also concerned with the occurrence, distribution and migration of halogen elements in the environment, especially agricultural and forestry ecosystems in space and in time. (author)

  19. Study of reactor characteristics for the adaptation of the monoelement standard method in activation analysis. Application to impurity determination in silicon

    Nuclear reactions by irradiation in a nuclear reactor are reviewed. Quantitative analysis by comparison with multielement standard is treated. Comparison methods using a monoelement standard, easier to use they require a previous study of neutronic characteristics of irradiation channels of reactors (thermal and epithermal flux ratio and eventual deviations fo epithermal neutron energy spectra from the 1/E relationship). Then analysis fo silicon polycrystals by both methods is studied and interfering reactions during irradiation are examined

  20. Neutron activation analysis of geochemical samples

    The present paper will describe the work done at the Technical Research Centre of Finland in developing methods for the large-scale activation analysis of samples for the geochemical prospecting of metals. The geochemical prospecting for uranium started in Finland in 1974 and consequently a manually operated device for the delayed neutron activation analysis of uranium was taken into use. During 1974 9000 samples were analyzed. The small capacity of the analyzer made it necessary to develop a completely automated analyzer which was taken into use in August 1975. Since then 20000-30000 samples have been analyzed annually the annual capacity being about 60000 samples when running seven hours per day. Multielemental instrumental neutron activation analysis is used for the analysis of more than 40 elements. Using instrumental epithermal neutron activation analysis 25-27 elements can be analyzed using one irradiation and 20 min measurement. During 1982 12000 samples were analyzed for mining companies and Geological Survey of Finland. The capacity is 600 samples per week. Besides these two analytical methods the analysis of lanthanoids is an important part of the work. 11 lanthanoids have been analyzed using instrumental neutron activation analysis. Radiochemical separation methods have been developed for several elements to improve the sensitivity of the analysis

  1. Materials characterization of radioactive waste forms using a multi-element detection method based on the instrumental neutron activation analysis. MEDINA

    Radioactive waste has to meet the specifications and acceptance criteria defined by national regulatory and management authorities for its intermediate and final storage. In Germany the Federal Office for Radiation Protection (Bundesamt fuer Strahlenschutz - BfS) has established waste acceptance requirements for the Konrad repository. Konrad is the disposal for radioactive waste with negligible heat generation and is located near the city of Salzgitter and is currently under construction. It will start operation not before the year 2021. The waste-acceptance-requirements are derived from a site-specific safety assessment. They include specific requirements on waste forms, packaging as well as limitations to activities of individual radionuclides and limitations to masses of non-radioactive harmful substances. The amount of chemically toxic elements in the waste is limited in order to avoid pollution of underground water reserves. To comply with these requirements every waste package has to be characterised in its radiological and chemical composition. This characterisation can be performed on the basis of existing documentation or, if the documentation is insufficient, on further analytical analysis. Segmented or integral gamma-scanning as well as active or passive neutron counting are used worldwide as the standard measurement methods for the radiological characterisation and quality checking of radioactive waste. These techniques determine the isotope specific activity of waste packages, but they do not allow the detection of non-radioactive hazardous substances inside the waste packages. Against this background the Institute of Nuclear Engineering and Technology Transfer (NET) at RWTH Aachen University and the Institute of Safety Research and Reactor Technology at Forschungszentrum Juelich jointly develop an innovative non-destructive analytical technique called MEDINA - ''Multi-Element Detection based on Instrumental Neutron Activation'' for

  2. Reliability and risk analysis methods research plan

    This document presents a plan for reliability and risk analysis methods research to be performed mainly by the Reactor Risk Branch (RRB), Division of Risk Analysis and Operations (DRAO), Office of Nuclear Regulatory Research. It includes those activities of other DRAO branches which are very closely related to those of the RRB. Related or interfacing programs of other divisions, offices and organizations are merely indicated. The primary use of this document is envisioned as an NRC working document, covering about a 3-year period, to foster better coordination in reliability and risk analysis methods development between the offices of Nuclear Regulatory Research and Nuclear Reactor Regulation. It will also serve as an information source for contractors and others to more clearly understand the objectives, needs, programmatic activities and interfaces together with the overall logical structure of the program

  3. SWOT ANALYSIS ON SAMPLING METHOD

    CHIS ANCA OANA

    2014-07-01

    Full Text Available Audit sampling involves the application of audit procedures to less than 100% of items within an account balance or class of transactions. Our article aims to study audit sampling in audit of financial statements. As an audit technique largely used, in both its statistical and nonstatistical form, the method is very important for auditors. It should be applied correctly for a fair view of financial statements, to satisfy the needs of all financial users. In order to be applied correctly the method must be understood by all its users and mainly by auditors. Otherwise the risk of not applying it correctly would cause loose of reputation and discredit, litigations and even prison. Since there is not a unitary practice and methodology for applying the technique, the risk of incorrectly applying it is pretty high. The SWOT analysis is a technique used that shows the advantages, disadvantages, threats and opportunities. We applied SWOT analysis in studying the sampling method, from the perspective of three players: the audit company, the audited entity and users of financial statements. The study shows that by applying the sampling method the audit company and the audited entity both save time, effort and money. The disadvantages of the method are difficulty in applying and understanding its insight. Being largely used as an audit method and being a factor of a correct audit opinion, the sampling method’s advantages, disadvantages, threats and opportunities must be understood by auditors.

  4. The use of hogdahl convention k0 neutron activation analysis (NAA) standardization method and atomic absortion spectroscopy (ASS) for determination of toxic elements in foodstuffs

    Copper, cadmium, tin, chromium, arsenic, antimony, vanadium and mercury contents were determined in various foodstuffs (Mussa paradisiaca (plantains), Manihot esculentus (cassavas), Vantosoma sagittifolium (cocoyam). Vantosoma sagittifolium leaves (kontomire), Lycopersicum esculentus (tomatoes), Capsicum species (peppers), Solanum melongena (garden eggs), Nbelmoschus esculentus (okro), and Colocasia esculenta (kooko or taro)) produced in the Wassa West District, Ghana. These plants are the basis of human nutrition in the study area. These elements were determined using Hogdahl convention k0 Instrumental Neutron Activation Analysis (NAA) Standardization Method and Atomic Absorption Spectroscopy (AAS). The elements in the various foodstuffs and their concentration ranges were Cu (16.87-180.06) mg/kg, As (2.68-9.84) µg/g, Cd (0.63-5.64) µg/g, Hg (0.01-67) ng/g, Cr (0.03-3.66) µg/g, Sb (1.1- 18.6) ng/g, Sn (3.4-58.4) ng/g, and V (12-99) ng/g. The study showed that there are high levels of toxic elements in the foodstuffs grown in the mining areas as compared to that of the non-mining area (i.e., control area). This could be attributed to gold mines pollution. Compared to the World Health Organization (WHO) permissible levels of toxic elements in foods, Cu, Cr and Hg were above the permissible levels whereas the concentrations of As, Cd. Sb, Sn and V fall within the permissible levels. (au)

  5. Evaluation of neutron flux parameters in irradiation sites of research reactor using the Westcott-formalism for the k0 neutron activation analysis method

    Kasban, H.; Hamid, Ashraf

    2015-12-01

    Instrumental Neutron Activation Analysis using k0 (k0-INAA) method has been used to determine a number of elements in sediment samples collected from El-Manzala Lake in Egypt. k0-INAA according to Westcott's formalism has been implemented using the complete irradiation kit of the fast pneumatic rabbit and some selected manually loaded irradiation sites for short and long irradiation at Egypt Second Research Reactor (ETRR-2). Zr-Au and Co sets as neutron flux monitors are used to determine the neutron flux parameters (f and α) in each irradiation sites. Two reference materials IAEA Soil-7 samples have been inserted and implemented for data validation and an internal monostandard multi monitor used (k0 based IM-NAA). It was given a good agreement between the experimental analyzed values and that obtained of the certified values. The major and trace elements in the sediment samples have been evaluated with the use of Co as an internal and Au as an external monostandard comparators. The concentrations of the elements (Cr, Mn and Zn) in the sediment samples of the present work are discussed regarding to those obtained from other sites.

  6. Statistical methods for bioimpedance analysis

    Christian Tronstad

    2014-04-01

    Full Text Available This paper gives a basic overview of relevant statistical methods for the analysis of bioimpedance measurements, with an aim to answer questions such as: How do I begin with planning an experiment? How many measurements do I need to take? How do I deal with large amounts of frequency sweep data? Which statistical test should I use, and how do I validate my results? Beginning with the hypothesis and the research design, the methodological framework for making inferences based on measurements and statistical analysis is explained. This is followed by a brief discussion on correlated measurements and data reduction before an overview is given of statistical methods for comparison of groups, factor analysis, association, regression and prediction, explained in the context of bioimpedance research. The last chapter is dedicated to the validation of a new method by different measures of performance. A flowchart is presented for selection of statistical method, and a table is given for an overview of the most important terms of performance when evaluating new measurement technology.

  7. Neutron activation analysis of reference materials

    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. TIBER activation analysis

    TIBER-II is an engineering test reactor designed to establish the technical feasibility for fusion, and is a U.S. option for the prospective International Thermonuclear Test Reactor (ITER). The TIBER-II baseline design has a 3 m major radius, 3.6 aspect ratio, and 1.1 MW/m2 average neutron wall loading. The inboard shield is about .5 m thick and structurally consists of tungsten alloy and PCA alloy. The outboard is 1.52 m thick and utilizes PCA as structure and beryllium as a neutron multiplier. An aqueous solution of 160 g LiNO3/liter is used throughout as a coolant and breeder. A one-dimensional cylindrical model for TIBER is used to calculate the neutron flux and the radioactivities. Activities are calculated during and after 2.5 full power years (FPY) of operation

  9. Evaluation of business activity using financial analysis

    Kučerová, Martina

    2012-01-01

    Czech University of Life Sciences Prague Faculty of Economics and Management Department of Trade and Accounting Abstract of Diploma Thesis Evaluation of business activity using financial analysis Martina Kučerová © 2012 CULS in Prague Summary: The aim of this thesis is to apply methods of financial analysis on chosen business for its first three accounting periods 2009, 2010 and 2011. The thesis is further analysis of my bachelor thesis on to...

  10. Statistical methods for bioimpedance analysis

    Christian Tronstad; Are Hugo Pripp

    2014-01-01

    This paper gives a basic overview of relevant statistical methods for the analysis of bioimpedance measurements, with an aim to answer questions such as: How do I begin with planning an experiment? How many measurements do I need to take? How do I deal with large amounts of frequency sweep data? Which statistical test should I use, and how do I validate my results? Beginning with the hypothesis and the research design, the methodological framework for making inferences based on measurements a...

  11. Nonlinear programming analysis and methods

    Avriel, Mordecai

    2003-01-01

    Comprehensive and complete, this overview provides a single-volume treatment of key algorithms and theories. The author provides clear explanations of all theoretical aspects, with rigorous proof of most results. The two-part treatment begins with the derivation of optimality conditions and discussions of convex programming, duality, generalized convexity, and analysis of selected nonlinear programs. The second part concerns techniques for numerical solutions and unconstrained optimization methods, and it presents commonly used algorithms for constrained nonlinear optimization problems. This g

  12. Activation of Students with Various Teaching Methods

    Andersen, Shuang Ma

    2011-01-01

    A group of teaching methodes to active engineer students have been tried out. The methodes are developed based on the Pedagogical Cyclic Workflow (PCW). Comparing with earlier evaluation, positive feedback is achieved among the students.......A group of teaching methodes to active engineer students have been tried out. The methodes are developed based on the Pedagogical Cyclic Workflow (PCW). Comparing with earlier evaluation, positive feedback is achieved among the students....

  13. Validation of k(0) standardization method in neutron activation analysis-The use of Kayzero for Windows programme at the nuclear physics institute, Rez

    Kubešová, Marie; Kučera, Jan

    2010-01-01

    Roč. 622, č. 2 (2010), s. 403-406. ISSN 0168-9002 Institutional research plan: CEZ:AV0Z10480505 Keywords : neutron activation analysis * k(0) standardization * Validation Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.142, year: 2010

  14. Anti–inflammatory activity and qualitative analysis of different extracts of Maytenus obscura (A. Rich.) Cuf. by high performance thin layer chromatography method

    Alajmi, Mohamed F.; Perwez Alam

    2014-01-01

    Objective: To perform aqueous ethanol soluble fraction (AESF) and dichloromethane extract of aerial parts of Maytenus obscura (A. Rich.) Cuf. using high performance thin layer chromatography (HPTLC) and to test anti-inflammatory activity of these extracts. Methods: HPTLC studies were carried out using CAMAG HPTLC system equipped with Linomat IV applicator, TLC scanner 3, Reprostar 3, CAMAG ADC 2 and WIN CATS-4 software were used. The anti-inflammatory activity was tested by injecting diffe...

  15. The psycho-activated linguistic method.

    Zivny, P

    1993-01-01

    A method for teaching foreign languages through the use of ten hypnotic sessions was developed. The method included the preparation of taped material for home application. The use of this method was analyzed in 153 subjects in Czechoslovakia, Russia and Italy. Preliminary analysis indicates that the method facilitates the learning of a foreign language. PMID:8070996

  16. Activation analysis using Cornell TRIGA

    A major use of the Cornell TRIGA is for activation analysis. Over the years many varieties of samples have been analyzed from a number of fields of interest ranging from geology, archaeology and textiles. More recently the analysis has been extended to high technology materials for applications in optical and semiconductor devices. Trace analysis in high purity materials like Si wafers has been the focus in many instances, while in others analysis of major/minor components were the goals. These analysis has been done using the delayed mode. Results from recent measurements in semiconductors and other materials will be presented. In addition the near future capability of using prompt gamma activation analysis using the Cornell cold neutron beam will be discussed. (author)

  17. Quick methods for radiochemical analysis

    Quick methods for radiochemical analysis, of adequate precision for the assay of a limited number of biologically important radionuclides, are important in the development of effective monitoring programs, particularly those that would be applied in emergency situations following an accidental release of radioactive substances. Methods of this type have been developed in a number of laboratories and are being altered and improved from time to time. The Agency invited several Member States to provide detailed information on any such procedures that might have been developed in their laboratories. From the information thus obtained a number of methods have been selected that appear to meet the criteria of speed and economy in the use of materials and equipment, and seem to be eminently suitable for those radionuclides that might be of major interest from the point of view of assessing the potential dose to persons following a serious dispersal of contamination. Refs, figs and tabs

  18. Gait analysis methods in rehabilitation

    Baker Richard

    2006-03-01

    Full Text Available Abstract Introduction Brand's four reasons for clinical tests and his analysis of the characteristics of valid biomechanical tests for use in orthopaedics are taken as a basis for determining what methodologies are required for gait analysis in a clinical rehabilitation context. Measurement methods in clinical gait analysis The state of the art of optical systems capable of measuring the positions of retro-reflective markers placed on the skin is sufficiently advanced that they are probably no longer a significant source of error in clinical gait analysis. Determining the anthropometry of the subject and compensating for soft tissue movement in relation to the under-lying bones are now the principal problems. Techniques for using functional tests to determine joint centres and axes of rotation are starting to be used successfully. Probably the last great challenge for optical systems is in using computational techniques to compensate for soft tissue measurements. In the long term future it is possible that direct imaging of bones and joints in three dimensions (using MRI or fluoroscopy may replace marker based systems. Methods for interpreting gait analysis data There is still not an accepted general theory of why we walk the way we do. In the absence of this, many explanations of walking address the mechanisms by which specific movements are achieved by particular muscles. A whole new methodology is developing to determine the functions of individual muscles. This needs further development and validation. A particular requirement is for subject specific models incorporating 3-dimensional imaging data of the musculo-skeletal anatomy with kinematic and kinetic data. Methods for understanding the effects of intervention Clinical gait analysis is extremely limited if it does not allow clinicians to choose between alternative possible interventions or to predict outcomes. This can be achieved either by rigorously planned clinical trials or using

  19. Experimental analysis of the mass eficiency curve for gross alphya activity and morphological study of the residue obtained by the co-precipitation method

    Montaña Gurrera, Montserrat; Camacho García, Antonia; Valles Murciano, M. Isabel; Serrano Carreño, M. Isabel

    2012-01-01

    Gross alpha activity determination in drinking water is one of the radiological parameters that must be determined in order to decide whether further specific analyses of radionuclides in samples is required. This parameter can be determined by the co-precipitation method using a ZnS(Ag) scintillation detector or a proportional counter. The method consists of collecting all alpha emitters of interest using barium and iron as carriers as they provide more uniform and homogeneous residues than ...

  20. Standardizing Activation Analysis: New Software for Photon Activation Analysis

    Photon Activation Analysis (PAA) of environmental, archaeological and industrial samples requires extensive data analysis that is susceptible to error. For the purpose of saving time, manpower and minimizing error, a computer program was designed, built and implemented using SQL, Access 2007 and asp.net technology to automate this process. Based on the peak information of the spectrum and assisted by its PAA library, the program automatically identifies elements in the samples and calculates their concentrations and respective uncertainties. The software also could be operated in browser/server mode, which gives the possibility to use it anywhere the internet is accessible. By switching the nuclide library and the related formula behind, the new software can be easily expanded to neutron activation analysis (NAA), charged particle activation analysis (CPAA) or proton-induced X-ray emission (PIXE). Implementation of this would standardize the analysis of nuclear activation data. Results from this software were compared to standard PAA analysis with excellent agreement. With minimum input from the user, the software has proven to be fast, user-friendly and reliable.

  1. Active teaching methods, studying responses and learning

    Christensen, Hans Peter; Vigild, Martin Etchells; Thomsen, Erik Vilain;

    Students’ study strategies when exposed to activating teaching methods are measured, analysed and compared to study strategies in more traditional lecture-based teaching.......Students’ study strategies when exposed to activating teaching methods are measured, analysed and compared to study strategies in more traditional lecture-based teaching....

  2. Active teaching methods, studying responses and learning

    Christensen, Hans Peter; Vigild, Martin Etchells; Thomsen, Erik Vilain;

    2010-01-01

    Students’ study strategies when exposed to activating teaching methods are measured, analysed and compared to study strategies in more traditional lecture-based teaching. The resulting learning outcome is discussed.......Students’ study strategies when exposed to activating teaching methods are measured, analysed and compared to study strategies in more traditional lecture-based teaching. The resulting learning outcome is discussed....

  3. Prospects for absolute neutron activation analysis

    The desirability for absolute neutron activation analysis(ANAA) is two-fold. Results by the comparitor method are only as good as the standards used, and also the method offers a chance of having the final results available within minutes of completing the analysis. In the past ANAA was not seriously considered because of the scarcity and poor qaulity of the nuclear data that were available. This situation is however steadily improving and the possible applications are being investigated. This report reviews the present status by considering the basic activation equation, calculation of parameters, the factors of importance and the size error one might expect

  4. Combination Clustering Analysis Method and its Application

    Bang-Chun Wen; Li-Yuan Dong; Qin-Liang Li; Yang Liu

    2013-01-01

    The traditional clustering analysis method can not automatically determine the optimal clustering number. In this study, we provided a new clustering analysis method which is combination clustering analysis method to solve this problem. Through analyzed 25 kinds of automobile data samples by combination clustering analysis method, the correctness of the analysis result was verified. It showed that combination clustering analysis method could objectively determine the number of clustering firs...

  5. Activation analysis with reactor neutrons

    The potentialities of neutron as an analytical probe are indicated, pointing out the need for development of other approaches, besides the conventional activation method. Development of instrumental approach to activation and applications, carried out at Analytical Chemistry Division are outlined. The role of, and the need for, the development and application of mathematical methods in enhancing the information content, and in turn the interpretation of the analytical results, is demonstrated. (author)

  6. Human hair neutron activation analysis: analysis on population level, mapping

    Neutron activation analysis is an outstanding analytical method having very wide applications in various fields. Analysis of human hair within last decades mostly based on neutron activation analysis is a very attractive illustration of the application of nuclear analytical techniques. Very interesting question is how the elemental composition differs in different areas or cities. In this connection the present paper gives average data and maps of various localities in the vicinity of drying-out Aral Sea and of various industrial cities in Central Asia. (author)

  7. Hybrid methods for cybersecurity analysis :

    Davis, Warren Leon,; Dunlavy, Daniel M.

    2014-01-01

    Early 2010 saw a signi cant change in adversarial techniques aimed at network intrusion: a shift from malware delivered via email attachments toward the use of hidden, embedded hyperlinks to initiate sequences of downloads and interactions with web sites and network servers containing malicious software. Enterprise security groups were well poised and experienced in defending the former attacks, but the new types of attacks were larger in number, more challenging to detect, dynamic in nature, and required the development of new technologies and analytic capabilities. The Hybrid LDRD project was aimed at delivering new capabilities in large-scale data modeling and analysis to enterprise security operators and analysts and understanding the challenges of detection and prevention of emerging cybersecurity threats. Leveraging previous LDRD research e orts and capabilities in large-scale relational data analysis, large-scale discrete data analysis and visualization, and streaming data analysis, new modeling and analysis capabilities were quickly brought to bear on the problems in email phishing and spear phishing attacks in the Sandia enterprise security operational groups at the onset of the Hybrid project. As part of this project, a software development and deployment framework was created within the security analyst work ow tool sets to facilitate the delivery and testing of new capabilities as they became available, and machine learning algorithms were developed to address the challenge of dynamic threats. Furthermore, researchers from the Hybrid project were embedded in the security analyst groups for almost a full year, engaged in daily operational activities and routines, creating an atmosphere of trust and collaboration between the researchers and security personnel. The Hybrid project has altered the way that research ideas can be incorporated into the production environments of Sandias enterprise security groups, reducing time to deployment from months and

  8. Neutron activation analysis in Bulgaria

    The development of instrumental neutron activation analysis (INAA) as a routine method started in 1960 with bringing into use of the experimental nuclear reactor 2 MW -IRT-2000. For the purposes of INAA the vertical channels were used. The neutron flux vary from 1 to 6x1012n/cm2s, with Cd ratio for gold of about 4,4. In one of the channels the neutron flux is additionally thermalised with grafite, in others - a pneumatic double-tube rabbit system is installed. One of the irradiation positions is equiped with 1 mm Cd shield constantly. With the pressure of the working gas (air) of 2 bar the transport time in one direction is 2,5 sec. Because of lack of special system for uniform irradiation an accuracy of 3% can be reached by use of iron monitors for long irradiations and copper monitors for use in the rabbit system. Two neutron generators are also working but the application of 14 MeV neutrons for INAA is still quite limited. The most developed are the applications of INAA in the fields of geology and paedology, medicine and biology, environment and pollution, archaeology, metallurgy, metrology and hydrology, criminology

  9. Probabilistic Models of Analysis of Loan Activity of Internet Banking

    Kondrateva Irina G.; Ostapenko Irina N.

    2012-01-01

    In article the main advantages of electronic banking in comparison with traditional, methods of the analysis of credit activity are considered. The special role is taken to the probabilistic method of analysis of credit activity in the Internet-bank. Modeling of activity of bank on the basis of probabilistic models of credit operations.

  10. Stability analysis of fractional-order generalized chaotic susceptible–infected–recovered epidemic model and its synchronization using active control method

    Sana P Ansari; Saurabh K Agrawal; Subir Das

    2015-01-01

    This paper presents the synchronization between a pair of identical susceptible–infected–recovered (SIR) epidemic chaotic systems and fractional-order time derivative using active control method. The fractional derivative is described in Caputo sense. Numerical simulation results show that the method is effective and reliable for synchronizing the fractional-order chaotic systems while it allows the system to remain in chaotic state. The striking features of this paper are: the successful presentation of the stability of the equilibrium state and the revelation that time for synchronization varies with the variation in fractional-order derivatives close to the standard one for different specified values of the parameters of the system.

  11. Development of RP-HPLC method for Qualitative Analysis of Active Ingredient (Gallic acid) from Stem Bark of Dendrophthoe falcate Linn.

    Hafsa Deshmukh; Pradnya J. Prabhu

    2011-01-01

    A simple, precise and sensitive, RP-HPLC method with UV detection at 271nm was developed and validated for qualitative determination of active ingredient Gallic acid from stem bark of Dendrophthoe falcate Linn. Separation was performed on a ThermoMOS 2 HYPERSIL C18 column (250 cm × 4.6 mm, 5µm ODS 3) using mobile phase comprising of 0.1% Orthophosphoric acid : Acetonitrile (400 cm3 : 600 cm3) with a flow rate of 1 ml/minute with a short run time of 13 minute. The method was validated accordi...

  12. INTER-COUNTRY EFFICIENCY EVALUATION IN INNOVATION ACTIVITY ON THE BASIS OF METHOD FOR DATA ENVELOPMENT ANALYSIS AMONG COUNTRIES WITH DEVELOPED AND DEVELOPING ECONOMY, INCLUDING THE REPUBLIC OF BELARUS

    I. V. Zhukovski

    2016-01-01

    Full Text Available The paper considers a problem on efficiency evaluation of innovation activity in 63 countries with developed and developing economies while using a method for data envelopment analysis. The following results of innovation activity have been used for calculation of an efficiency factor: export of high-technology products as percentage of industrial product export, export of ICT services as percentage of services export and payments obtained due to realization of intellectual property rights (in US dollars. A model of the data envelopment analysis with a changeable scale-dependent effect and which is directed on maximization of the obtained results (output-oriented VRS model has been used for the analysis. The evaluation has shown that such countries as the USA, Israel, Sweden and some others have maximum efficiency of resource transformation into innovative activity output. The executed analysis has revealed that the Republic of Belarus has a potential for improvement of indices on innovation results.

  13. Neutron activation analysis helps in picture attribution

    The neutron activation analysis application for obtaining the data useful for proper attribution of paintings has been presented on the base of several examples. The identification on this way of dye elements, pigments and other painting materials is an important element among the physico-chemical methods helping the attribution procedure of old painting objects

  14. Neutron Activation Analysis with k0 Standardization

    SCK-CEN's programme on Neutron Activation Analysis with k0-standardisation aims to: (1) develop and implement k0-standardisation method for NAA; (2) to exploit the inherent qualities of NAA such as accuracy, traceability, and multi-element capability; (3) to acquire technical spin-off for nuclear measurements services. Main achievements in 1997 are reported

  15. The influence of friends and psychosocial factors on physical activity and screen time behavior in adolescents: a mixed-methods analysis.

    Garcia, Jeanette M; Sirard, John R; Deutsch, Nancy L; Weltman, Arthur

    2016-08-01

    (1) Determine the association between adolescent moderate-to-vigorous physical activity (MVPA) and screen time with their nominated friends' behaviors and (2) explore potential mechanisms of friends' social influences on MVPA and screen time. Participants consisted of 152 adolescents (mean age: 14.5 years, 53 % female, 50 % high school, 80 % Caucasian). MVPA was measured with an Actigraph GT3X+ accelerometer. Demographic and psychosocial variables were assessed via questionnaires. Participants nominated up to 5 friends who completed MVPA and screen time questionnaires. A subset of adolescents (n = 108) participated in focus groups that examined potential mechanism of friends' influence on MVPA and screen time. Multiple regression analysis examined the association of demographic, psychological, and nominated friend variables with participants' MVPA and screen time. NVivo 10.0 was used to analyze qualitative data. Greater levels of friends' MVPA was associated with greater levels of MVPA in both males (p friends' screen time was associated with greater levels of screen time in males (p = .04) while psychosocial variables, such as increased screen time enjoyment, were associated with increased screen time in females (p = .01). School level was not associated with either MVPA or screen time. Focus group data indicated that friends positively influenced participants' MVPA through engaging in activity with participants, verbal encouragement, and modeling of MVPA. All participants preferred to be active with friends rather than alone, however, females preferred activity with a close friend while males preferred to be active with a group. Enjoyment of MVPA was the most cited reason for engaging in MVPA with friends. The majority of participants reported friends not having an influence on screen time. Adolescents with active friends are more likely to be physically active and spend less time engaging in screen-based behaviors. Interventions to increase MVPA in

  16. Data Analysis Methods for Paleogenomics

    Avila Arcos, Maria del Carmen

    , thanks to the introduction of NGS and the implementation of data analysis methods specific for each project. Chapters 1 to 3 have been published in peer-reviewed journals and Chapter 4 is currently in review. Chapter 5 consists of a manuscript describing initial results of an ongoing research project...... of sequence data, generated using next-generation sequencing (NGS) technologies, from either forensic (Chapter 1) or ancient (Chapters 2-5) materials. These chapters present projects very different in nature, reflecting the diversity of questions that have become possible to address in the ancient DNA field......, for which more data is currently being generated; therefore it should be interpreted as a preliminary report. In addition to the five chapters, an introduction and five appendices are included. Appended articles are included for the reader's interest, these represent the collaborations I have been part...

  17. Neutron activation analysis of coins

    Activation analysis was applied to the study of coins using 14MeV neutrons produced by an accelerator for the determination of oxygen and neutrons emitted from a 252Cf source for the determination of the other elements (Au, Ag, Cu, As etc...). The advantages of this technique are presented

  18. Automated activation-analysis system

    An automated delayed neutron counting and instrumental neutron activation analysis system has been developed at Los Alamos National Laboratory's Omega West Reactor (OWR) to analyze samples for uranium and 31 additional elements with a maximum throughput of 400 samples per day. The system and its mode of operation for a large reconnaissance survey are described

  19. Computational methods for global/local analysis

    Ransom, Jonathan B.; Mccleary, Susan L.; Aminpour, Mohammad A.; Knight, Norman F., Jr.

    1992-01-01

    Computational methods for global/local analysis of structures which include both uncoupled and coupled methods are described. In addition, global/local analysis methodology for automatic refinement of incompatible global and local finite element models is developed. Representative structural analysis problems are presented to demonstrate the global/local analysis methods.

  20. Activities in the Dynamic Occupational Therapy Method

    Jô Benetton; Taís Quevedo Marcolino

    2013-01-01

    This paper addresses the concept and use of the instrument named ‘activities’ in occupational therapy, sustained by the propositions of the Dynamic Occupational Therapy Method (DOTM). Initially, we present general aspects related to the activities in the DOTM such as the option for the name ‘activities’, its conceptual definition, use as a tool, and active participation in the dynamic of triadic relationship. Further, it approaches the character of activities: therapeutic, educational and soc...

  1. Neutron activation spectrometry and neutron activation analysis in analytical geochemistry

    The present report is to show the geochemists who are interested in neutron activation spectrometry (NAS) and neutron activation analysis (NAA) which analytical possibilities these methods offer him. As a review of these analytical possibilities, a lieterature compolation is given which is subdivided into two groups: 1) rock (basic, intermediary, acid, sediments, soils and nuds, diverse minerals, tectites, meteorites and lunar material). 2) ore (Al, Au, Be, Cr, Cu, Mn, Mo, Fe, Pb, Pt, Sn, Ti, W, Zn, Zr, U and phosphate ore, polymetallic ores, fluorite, monazite and diverse ores). The applied methods as well as the determinable elements in the given materials can be got from the tables. On the whole, the literature evaluation carried out makes it clear that neutron activation spectrometry is a very useful multi-element method for the analysis of rocks. The analysis of ores, however, is subjected to great limitations. As rock analysis is very frequently of importance in prospecting for ore deposits, the NAS proves to be extremely useful for this very field of application. (orig./LH)

  2. Sensitivity analysis for activation problems

    A study has been made about how to develop further the techniques for sensitivity analysis used by FISPACT-II. FISPACT-II is a software suite for the analysis of nuclear activation and transmutation problems, developed for all nuclear applications. The software already permits sensitivity analysis to be performed by Monte Carlo sampling, and a faster uncertainty analysis is made possible by a powerful graph-based approach which generates a reduced set of nuclides on pathways leading to significant contributions to radiological quantities. The peculiar aspects of the sensitivity analysis problem for activation are the large number, typically thousands, of rate equation parameters (decay rates and reaction cross-sections) which all have some degree of associated error, and the fact that activity as a function of time varies as a sum of exponentials, so appears discontinuous as rate parameters are varied unless the sampling frequency is impracticably fast. Nevertheless, Monte Carlo sampling is a generic approach and it is therefore conceivable that techniques more targeted to the activation problem might be beneficial. Moreover, recent theoretical developments have highlighted the importance of a two-stage approach to mathematically similar problems, where in the first stage, information is collected about the global behaviour of the problem, such as the identification of the rate parameters which cause the greatest variation in dose or nuclear activity, before a second stage examines a problem with its scope restricted by the information from the first. In the second stage, for example, Quasi-Monte Carlo sampling may be used in a restricted parameter space. The current work concentrates on the first stage and consists of a review of possible techniques with a detailed examination of the most promising pathways reduction approach, examined directly using FISPACT-II. All the evidence obtained demonstrates the strong potential of this approach. (authors)

  3. Activation analysis of air particulate matter

    This review on activation analysis of air particulate matter is an extended and updated version of a review given by the same authors in 1985. The main part is aimed at the analytical scheme and refers to rules and techniques for sampling, sample and standard preparation, irradiation and counting procedures, as well as data processing, - evaluation, and - presentation. Additional chapters deal with relative and monostandard methods, the use of activation analysis for atmosphere samples in various localities, and level of toxic and other elements in the atmosphere. The review contains 190 references. (RB)

  4. Activation analysis as applied to environmental substances

    The historical background of activation analysis as applied to environmental problems is first briefly described. Then, the present state of its utilization for environmental samples, mainly atmospheric floating particles and human hairs, is reviewed. The problem with irradiation reactors is also mentioned. In the activation analysis of environmental substances, the instrumental neutron activation analysis (INAA) with the thermal neutrons in reactors is the main; besides, there are the methods with bremsstrahlung, etc. The INAA is most effectively used for atmospheric airborne particles and the micro-elements in human hairs. In Japan, the INAA is currently employed by the Environmental Agency in its national air pollution surveillance network for metallic pollutants. The problem with reactors is the limited capacity for thermal neutron irradiation. (Mori, K.)

  5. High-capacity neutron activation analysis facility

    A high-capacity neutron activation analysis facility, the Reactor Activation Facility, was designed and built and has been in operation for about a year at one of the Savannah River Plant's production reactors. The facility determines uranium and about 19 other elements in hydrogeochemical samples collected in the National Uranium Resource Evaluation program, which is sponsored and funded by the United States Department of Energy, Grand Junction Office. The facility has a demonstrated average analysis rate of over 10,000 samples per month, and a peak rate of over 16,000 samples per month. Uranium is determined by cyclic activation and delayed neutron counting of the U-235 fission products; other elements are determined from gamma-ray spectra recorded in subsequent irradiation, decay, and counting steps. The method relies on the absolute activation technique and is highly automated for round-the-clock unattended operation

  6. Activation analysis using γ photons

    This report summarizes all the data required for using photonuclear reactions in the field of analysis. After a brief review of the elementary properties of nuclear reactions induced by photon irradiation, the main characteristics are given of high energy (E > 20 MeV) Bremsstrahlung sources. The principle of activation analysis based on the use of photons is given. Actual examples of the analytic possibilities are described in detail, in particular in the case of the determination of very small quantities (-6) of C, N, O and F. The influence of interfering nuclear reactions is discussed. (author)

  7. A solid-phase microextraction GC/MS/MS method for rapid quantitative analysis of food and beverages for the presence of legally restricted biologically active flavorings.

    Bousova, Katerina; Mittendorf, Klaus; Senyuva, Hamide

    2011-01-01

    A method was developed using automated headspace solid-phase microextraction coupled with GC/MS/MS to simultaneously determine the presence of seven biologically active flavoring substances whose levels of use in processed foods is controlled by statutory limits. The method can be applied to identify and quantify the presence of 1,2-benzopyrone (coumarin), beta-asarone, 1-allyl-4-methoxybenzene (estragole), menthofuran, 4-allyl-1 ,2-dimethoxybenzene (methyl eugenol), pulegone, and thujone at levels ranging from 0.5 to 3000 mg/kg. The method has been optimized and validated for three different generic food types categorized on the basis of composition and anticipated use levels of flavorings and food ingredients. The food categories are alcoholic and nonalcoholic beverages; semisolid processed foods (e.g., soups, sauces, confectionary, etc.); and solid foods (muesli, bakery products, etc.). The method is simple, inexpensive, and rapid, and eliminates the use of flammable and toxic solvents. There is no sample preparation, and using MSIMS, unequivocal confirmation of identification is achieved even in highly complex matrixes containing many potential interfering volatiles. The method precision for spiked samples ranged from 2 to 21%, with the greatest variability associated with solid matrixes. The LOD and LOQ values were well below 0.1 and 0.5 mg/kg, respectively, in all cases for individual substances, fulfilling requirements for enforcement purposes. The robustness of the method was demonstrated in a small survey of retail samples of four spirits, five flavored milks, three energy drinks, five liqueurs, five soups, 10 sauces, five herbal teas, and three breakfast cereals. PMID:21919351

  8. Analysis and estimation of risk management methods

    Kankhva Vadim Sergeevich

    2016-05-01

    Full Text Available At the present time risk management is an integral part of state policy in all the countries with developed market economy. Companies dealing with consulting services and implementation of the risk management systems carve out a niche. Unfortunately, conscious preventive risk management in Russia is still far from the level of standardized process of a construction company activity, which often leads to scandals and disapproval in case of unprofessional implementation of projects. The authors present the results of the investigation of the modern understanding of the existing methodology classification and offer the authorial concept of classification matrix of risk management methods. Creation of the developed matrix is based on the analysis of the method in the context of incoming and outgoing transformed information, which may include different elements of risk control stages. So the offered approach allows analyzing the possibilities of each method.

  9. Fourier methods for biosequence analysis.

    Benson, D C

    1990-01-01

    Novel methods are discussed for using fast Fourier transforms for DNA or protein sequence comparison. These methods are also intended as a contribution to the more general computer science problem of text search. These methods extend the capabilities of previous FFT methods and show that these methods are capable of considerable refinement. In particular, novel methods are given which (1) enable the detection of clusters of matching letters, (2) facilitate the insertion of gaps to enhance seq...

  10. Neutron activation analysis of geological materials

    Neutron activation analysis (NAA) is an extremely sensitive, selective and precise method, which yields a wealth of elemental information from even a small-sized sample. With the recent advances in nuclear reactors and high-efficiency and high-resolution semiconductor detectors, NAA has become a powerful method for multielemental analysis. The concentration of major, minor, and trace elements vary from 1 to 4 orders of magnitude in geological materials. By varying neutron fluxes, irradiation times, decay and counting intervals and using both instrumental and radiochemical techniques in NAA, it is possible to accurately determine about 50 elements in a sample aliquant. The practical aspects of the NAA method as applied to geological materials are discussed in detail, and are demonstrated by the analysis of the United States Geological Survey (USGS) and the International Atomic Energy Agency (IAEA) standard reference geological materials. General aspects of the elemental interpretations in terrestrial samples are also discussed. (author)

  11. Probabilistic methods for structural response analysis

    Wu, Y.-T.; Burnside, O. H.; Cruse, T. A.

    1988-01-01

    This paper addresses current work to develop probabilistic structural analysis methods for integration with a specially developed probabilistic finite element code. The goal is to establish distribution functions for the structural responses of stochastic structures under uncertain loadings. Several probabilistic analysis methods are proposed covering efficient structural probabilistic analysis methods, correlated random variables, and response of linear system under stationary random loading.

  12. Spectroscopic Chemical Analysis Methods and Apparatus

    Hug, William F.; Reid, Ray D.

    2012-01-01

    This invention relates to non-contact spectroscopic methods and apparatus for performing chemical analysis and the ideal wavelengths and sources needed for this analysis. It employs deep ultraviolet (200- to 300-nm spectral range) electron-beam-pumped wide bandgap semiconductor lasers, incoherent wide bandgap semiconductor lightemitting devices, and hollow cathode metal ion lasers. Three achieved goals for this innovation are to reduce the size (under 20 L), reduce the weight [under 100 lb (.45 kg)], and reduce the power consumption (under 100 W). This method can be used in microscope or macroscope to provide measurement of Raman and/or native fluorescence emission spectra either by point-by-point measurement, or by global imaging of emissions within specific ultraviolet spectral bands. In other embodiments, the method can be used in analytical instruments such as capillary electrophoresis, capillary electro-chromatography, high-performance liquid chromatography, flow cytometry, and related instruments for detection and identification of unknown analytes using a combination of native fluorescence and/or Raman spectroscopic methods. This design provides an electron-beampumped semiconductor radiation-producing method, or source, that can emit at a wavelength (or wavelengths) below 300 nm, e.g. in the deep ultraviolet between about 200 and 300 nm, and more preferably less than 260 nm. In some variations, the method is to produce incoherent radiation, while in other implementations it produces laser radiation. In some variations, this object is achieved by using an AlGaN emission medium, while in other implementations a diamond emission medium may be used. This instrument irradiates a sample with deep UV radiation, and then uses an improved filter for separating wavelengths to be detected. This provides a multi-stage analysis of the sample. To avoid the difficulties related to producing deep UV semiconductor sources, a pumping approach has been developed that uses

  13. Overview of activities related to the WGCS/AG2 in the study of structural analysis methods and damage models for the development of design rules

    , two other areas, one related to Research and Development programmes the other to and industrial projects conducted by EU organizations, have been an important source of input to the WGCS work. Therefore, it could be mentioned that the work produced by the WGCS moves amongst the three boundary areas described above. Paper describes the outstanding studies and ongoing activities of the WGCS including simplified calculation methods and established computational techniques as well as constitutive equations needed for complicated material descriptions and benchmarks

  14. 7th international conference ''Modern trends in activation analysis''

    The conference was held on 23-27 June, 1986 in Copenhagen (DK) with the participation of specialists from 42 countries. 175 papers were submitted covering the wide field of applications of neutron activation analysis, from novel techniques to sample preparation, information processes and control, activation techniques, light element and rare earth element determination, ultratracer analysis, quality assurance, comparator methods, and reference materials. The poster session was mainly oriented to industrial applications of activation analysis, biological applications, in vivo use of neutron activation analysis, the applications of neutron activation analysis in environmental control, criminology, etc. (E.S.)

  15. A catalog of automated analysis methods for enterprise models.

    Florez, Hector; Sánchez, Mario; Villalobos, Jorge

    2016-01-01

    Enterprise models are created for documenting and communicating the structure and state of Business and Information Technologies elements of an enterprise. After models are completed, they are mainly used to support analysis. Model analysis is an activity typically based on human skills and due to the size and complexity of the models, this process can be complicated and omissions or miscalculations are very likely. This situation has fostered the research of automated analysis methods, for supporting analysts in enterprise analysis processes. By reviewing the literature, we found several analysis methods; nevertheless, they are based on specific situations and different metamodels; then, some analysis methods might not be applicable to all enterprise models. This paper presents the work of compilation (literature review), classification, structuring, and characterization of automated analysis methods for enterprise models, expressing them in a standardized modeling language. In addition, we have implemented the analysis methods in our modeling tool. PMID:27047732

  16. Methods for using polypeptides having cellobiohydrolase activity

    Morant, Marc D; Harris, Paul

    2016-08-23

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  17. Constructing an Intelligent Patent Network Analysis Method

    Wu, Chao-Chan; Yao, Ching-Bang

    2012-01-01

    Patent network analysis, an advanced method of patent analysis, is a useful tool for technology management. This method visually displays all the relationships among the patents and enables the analysts to intuitively comprehend the overview of a set of patents in the field of the technology being studied. Although patent network analysis possesses relative advantages different from traditional methods of patent analysis, it is subject to several crucial limitations. To overcome the drawbacks...

  18. Reactor neutron activation analysis of industrial materials

    The specific application of neutron activation analysis (n.a.a.) for industrial materials is demonstrated by the determination of impurities in BeO, Al, Si, Cu, Ge, GaP, GaAs, steel, and irradiated uranium. A group scheme gives an orientation about the possibilities of n.a.a. The use of different standards, methods for the measurement of low radioactivities and errors caused by recoil reaction and radiation stimulated diffusion are discussed. (author)

  19. 3D analysis methods - Study and seminar

    The first part of the report results from a study that was performed as a Nordic co-operation activity with active participation from Studsvik Scandpower and Westinghouse Atom in Sweden, and VTT in Finland. The purpose of the study was to identify and investigate the effects rising from using the 3D transient com-puter codes in BWR safety analysis, and their influence on the transient analysis methodology. One of the main questions involves the critical power ratio (CPR) calculation methodology. The present way, where the CPR calculation is per-formed with a separate hot channel calculation, can be artificially conservative. In the investigated cases, no dramatic minimum CPR effect coming from the 3D calculation is apparent. Some cases show some decrease in the transient change of minimum CPR with the 3D calculation, which confirms the general thinking that the 1D calculation is conservative. On the other hand, the observed effect on neutron flux behaviour is quite large. In a slower transient the 3D effect might be stronger. The second part of the report is a summary of a related seminar that was held on the 3D analysis methods. The seminar was sponsored by the Reactor Safety part (NKS-R) of the Nordic Nuclear Safety Research Programme (NKS). (au)

  20. Anti-inflammatory activity and qualitative analysis of different extracts of Maytenus obscura (A. Rich.) Cuf. by high performance thin layer chromatography method

    Mohamed F. Alajmi; Perwez Alam

    2014-01-01

    Objective: To perform aqueous ethanol soluble fraction (AESF) and dichloromethane extract of aerial parts of Maytenus obscura (A. Rich.) Cuf. using high performance thin layer chromatography (HPTLC) and to test anti-inflammatory activity of these extracts.Methods:HPTLC studies were carried out using CAMAG HPTLC system equipped with Linomat IV applicator, TLC scanner 3, Reprostar 3, CAMAG ADC 2 and WIN CATS-4 software were used. The anti-inflammatory activity was tested by injecting different groups of rats (6 each) with formalin in hind paw and measuring the edema volume before and 1 h later formalin injection. Control group received saline i.p. The extracts treatment was injected i.p. in doses of 100 and 200 mg/kg 1 h before formalin administration. Indomethacin (30 mg/kg) was used as standard.Results:The results of preliminary phytochemical studies confirmed the presence of protein, lipid, carbohydrate, phenol, flavonoid, saponin, triterpenoid, alkaloid and anthraquinone in both extracts. Chromatography was performed on glass-backed silica gel 60 F254 HPTLC plates with the green solvents toluene: ethyacetate: glacial acetic acid (5:3:0.2, v/v/v) as mobile phase. HPTLC finger printing of AESF revealed major eight peaks with Rf values in the range of 0.28 to 0.80 and the dichloromethane revealed major 11 peaks with Rf values in the range of 0.12 to 0.76. The purity of sample was confirmed by comparing the absorption spectra at start, middle and end position of the band. Treatment of rats (i.p.) with AESF and dichloromethane in doses of 100 and 200 mg/kg inhibited singnificantly (P<0.05, n=6) formalin-induced inflammation by 50%, 55.9%, 45.5%, and 51.4%, respectively.Conclusions:HPTLC finger printing of AESF and dichloromethane of Maytenus obscura revealed eight major spots for alcoholic extracts and nine major spots for dichloromethane extracts. These HPTLC profiles may be of great usefulness in the quality control of herbal products containing these extracts. The

  1. Probabilistic structural analysis methods of hot engine structures

    Chamis, C. C.; Hopkins, D. A.

    1989-01-01

    Development of probabilistic structural analysis methods for hot engine structures is a major activity at Lewis Research Center. Recent activities have focused on extending the methods to include the combined uncertainties in several factors on structural response. This paper briefly describes recent progress on composite load spectra models, probabilistic finite element structural analysis, and probabilistic strength degradation modeling. Progress is described in terms of fundamental concepts, computer code development, and representative numerical results.

  2. Neutron Activation analysis of waste water

    An instrumental neutron activation analysis for the simultaneous determination of chlorine, bromine, sodium, manganese, cobalt, copper, chromium, zinc, nickel, antimony and iron in waste water is described. They were determined in waste water samples under normal conditions by non-destructive neutron activation simultaneously using a suitable monostandard method. Standardized water samples were used and irradiated in polyethylene ampoules at a neutron flux of 1013 cm-2 s-1 for periods of 1 minute, 1 and 10 hours. A Ge hyperpure detector was used for your activity determination, with count times of 60, 180, 300 and 600 seconds. The obtained results show than the method can be utilized for the determination of this elements without realize anything previous treatment of the samples. (Author)

  3. Evaluation of methods to assess physical activity

    Leenders, Nicole Y. J. M.

    Epidemiological evidence has accumulated that demonstrates that the amount of physical activity-related energy expenditure during a week reduces the incidence of cardiovascular disease, diabetes, obesity, and all-cause mortality. To further understand the amount of daily physical activity and related energy expenditure that are necessary to maintain or improve the functional health status and quality of life, instruments that estimate total (TDEE) and physical activity-related energy expenditure (PAEE) under free-living conditions should be determined to be valid and reliable. Without evaluation of the various methods that estimate TDEE and PAEE with the doubly labeled water (DLW) method in females there will be eventual significant limitations on assessing the efficacy of physical activity interventions on health status in this population. A triaxial accelerometer (Tritrac-R3D, (TT)), an uniaxial (Computer Science and Applications Inc., (CSA)) activity monitor, a Yamax-Digiwalker-500sp°ler , (YX-stepcounter), by measuring heart rate responses (HR method) and a 7-d Physical Activity Recall questionnaire (7-d PAR) were compared with the "criterion method" of DLW during a 7-d period in female adults. The DLW-TDEE was underestimated on average 9, 11 and 15% using 7-d PAR, HR method and TT. The underestimation of DLW-PAEE by 7-d PAR was 21% compared to 47% and 67% for TT and YX-stepcounter. Approximately 56% of the variance in DLW-PAEE*kgsp{-1} is explained by the registration of body movement with accelerometry. A larger proportion of the variance in DLW-PAEE*kgsp{-1} was explained by jointly incorporating information from the vertical and horizontal movement measured with the CSA and Tritrac-R3D (rsp2 = 0.87). Although only a small amount of variance in DLW-PAEE*kgsp{-1} is explained by the number of steps taken per day, because of its low cost and ease of use, the Yamax-stepcounter is useful in studies promoting daily walking. Thus, studies involving the

  4. Instrumentation in neutron activation analysis

    The rise of neutron activation analysis (NAA) as a tool in geochemical research has parallelled advances in detector, multi-channel analyzer, and computer technology. Micro-computers are now being integrated into NAA systems, and gamma-ray spectrometer instrumentation is evolving towards direct-reading systems. The investigator is faced with a wide range of possibilities and choices when equipping or re-equipping a laboratory. The geoscientist is provided with an overview of the available instrumentation and what soon may be feasible. (L.L.)

  5. Evaluation methods of SWOT analysis

    VANĚK, Michal; Mikoláš, Milan; Žváková, Kateřina

    2012-01-01

    Strategic management is an integral part of top management. By formulating the right strategy and its subsequent implementation, a managed organization can attract and retain a comparative advantage. In order to fulfil this expectation, the strategy also has to be supported with relevant findings of performed strategic analyses. The best known and probably the most common of these is a SWOT analysis. In practice, however, the analysis is reduced to mere presentation of influence factors, whic...

  6. Space-Borne and Ground-Based Sar Interferometry for Landslide Activity Analysis and Monitoring in the Appennines of Emilia Romagna (Italy): Review of Methods and Preliminary Results

    Barbieri, M.; Corsini, A.; Casagli, N.; Farina, P.; Coren, F.; Sterzai, P.; Leva, D.; Tarchi, D.

    2004-06-01

    This work concerns the application of SAR interferometry for the assessment of the long-term analysis of the state of activity of deep seated mass movements affecting some urban areas in the northern Appennines of Emilia Romagna region (from 1994-2001 space-borne ERS data) and for the real-time monitoring of active flow-like landslides in year 2002 (from ground-based system). These activities are part of an ongoing research project supported by civil protection authorities of the Emilia-Romagna region that involves several research institutes with diverse expertises. A set of test sites characterized by a high landslide risk have been selected mainly taking into account phenomena characteristics such as deformation rates and vegetation coverage, with respect to the employed techniques. After a preliminary detailed geomorphologic characterization of the sites, the interferometric analyses, still in progress, have been implemented. In particular space-borne DInSAR has been applied for 10 unstable areas using a set of ERS1/ERS2 data acquired in the last 7 years. From 9 interferograms, the line-of-sight displacement maps have been calculated and, later on, post processed in GIS environment in order to have on-slope-direction displacement maps that could fully be integrated with geomorphologic and ancillary data and that could semi-quantitatively be compared with other traditional monitoring data. The results obtained have been rather satisfactory, especially in some test sites where entire villages are settled on the mass movement, as in the case of Berceto (Parma) presented in the paper, and post-processed products have proved a significant amelioration of basic interferometric ones. Moreover, in order to measure terrain displacements induced by landslide characterized by high deformation rates and little urbanisation, ground-based SAR interferometry (GBInSAR) has been used for the monitoring of a test site located in the province of Bologna. This application proved

  7. Convergence analysis of combinations of different methods

    Kang, Y. [Clarkson Univ., Potsdam, NY (United States)

    1994-12-31

    This paper provides a convergence analysis for combinations of different numerical methods for solving systems of differential equations. The author proves that combinations of two convergent linear multistep methods or Runge-Kutta methods produce a new convergent method of which the order is equal to the smaller order of the two original methods.

  8. Probabilistic methods in combinatorial analysis

    Sachkov, Vladimir N

    2014-01-01

    This 1997 work explores the role of probabilistic methods for solving combinatorial problems. These methods not only provide the means of efficiently using such notions as characteristic and generating functions, the moment method and so on but also let us use the powerful technique of limit theorems. The basic objects under investigation are nonnegative matrices, partitions and mappings of finite sets, with special emphasis on permutations and graphs, and equivalence classes specified on sequences of finite length consisting of elements of partially ordered sets; these specify the probabilist

  9. Nonlinear structural analysis using integrated force method

    N R B Krishnam Raju; J Nagabhushanam

    2000-08-01

    Though the use of the integrated force method for linear investigations is well-recognised, no efforts were made to extend this method to nonlinear structural analysis. This paper presents the attempts to use this method for analysing nonlinear structures. General formulation of nonlinear structural analysis is given. Typically highly nonlinear bench-mark problems are considered. The characteristic matrices of the elements used in these problems are developed and later these structures are analysed. The results of the analysis are compared with the results of the displacement method. It has been demonstrated that the integrated force method is equally viable and efficient as compared to the displacement method.

  10. Large sample neutron activation analysis of a ceramic vase

    Stamatelatos, I.E.; Tzika, F.; Vasilopoulou, T.; Koster-Ammerlaan, M.J.J.

    2010-01-01

    Large Sample Neutron Activation Analysis (LSNAA) was applied to perform non-destructive elemental analysis of a ceramic vase. Appropriate neutron self-shielding and gamma ray detection efficiency calibration factors were derived using Monte Carlo code MCNP5. The results of LSNAA were compared against Instrumental Neutron Activation Analysis (INAA) results and a satisfactory agreement between the two methods was observed. The ratio of derived concentrations between the two methods was within 0...