WorldWideScience

Sample records for chemical analysis

  1. Chemical Security Analysis Center

    Data.gov (United States)

    Federal Laboratory Consortium — In 2006, by Presidential Directive, DHS established the Chemical Security Analysis Center (CSAC) to identify and assess chemical threats and vulnerabilities in the...

  2. Chemical exchange program analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Waffelaert, Pascale

    2007-09-01

    As part of its EMS, Sandia performs an annual environmental aspects/impacts analysis. The purpose of this analysis is to identify the environmental aspects associated with Sandia's activities, products, and services and the potential environmental impacts associated with those aspects. Division and environmental programs established objectives and targets based on the environmental aspects associated with their operations. In 2007 the most significant aspect identified was Hazardous Materials (Use and Storage). The objective for Hazardous Materials (Use and Storage) was to improve chemical handling, storage, and on-site movement of hazardous materials. One of the targets supporting this objective was to develop an effective chemical exchange program, making a business case for it in FY07, and fully implementing a comprehensive chemical exchange program in FY08. A Chemical Exchange Program (CEP) team was formed to implement this target. The team consists of representatives from the Chemical Information System (CIS), Pollution Prevention (P2), the HWMF, Procurement and the Environmental Management System (EMS). The CEP Team performed benchmarking and conducted a life-cycle analysis of the current management of chemicals at SNL/NM and compared it to Chemical Exchange alternatives. Those alternatives are as follows: (1) Revive the 'Virtual' Chemical Exchange Program; (2) Re-implement a 'Physical' Chemical Exchange Program using a Chemical Information System; and (3) Transition to a Chemical Management Services System. The analysis and benchmarking study shows that the present management of chemicals at SNL/NM is significantly disjointed and a life-cycle or 'Cradle-to-Grave' approach to chemical management is needed. This approach must consider the purchasing and maintenance costs as well as the cost of ultimate disposal of the chemicals and materials. A chemical exchange is needed as a mechanism to re-apply chemicals on site. This

  3. Chemical process hazards analysis

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-01

    The Office of Worker Health and Safety (EH-5) under the Assistant Secretary for the Environment, Safety and Health of the US Department (DOE) has published two handbooks for use by DOE contractors managing facilities and processes covered by the Occupational Safety and Health Administration (OSHA) Rule for Process Safety Management of Highly Hazardous Chemicals (29 CFR 1910.119), herein referred to as the PSM Rule. The PSM Rule contains an integrated set of chemical process safety management elements designed to prevent chemical releases that can lead to catastrophic fires, explosions, or toxic exposures. The purpose of the two handbooks, ``Process Safety Management for Highly Hazardous Chemicals`` and ``Chemical Process Hazards Analysis,`` is to facilitate implementation of the provisions of the PSM Rule within the DOE. The purpose of this handbook ``Chemical Process Hazards Analysis,`` is to facilitate, within the DOE, the performance of chemical process hazards analyses (PrHAs) as required under the PSM Rule. It provides basic information for the performance of PrHAs, and should not be considered a complete resource on PrHA methods. Likewise, to determine if a facility is covered by the PSM rule, the reader should refer to the handbook, ``Process Safety Management for Highly Hazardous Chemicals`` (DOE- HDBK-1101-96). Promulgation of the PSM Rule has heightened the awareness of chemical safety management issues within the DOE. This handbook is intended for use by DOE facilities and processes covered by the PSM rule to facilitate contractor implementation of the PrHA element of the PSM Rule. However, contractors whose facilities and processes not covered by the PSM Rule may also use this handbook as a basis for conducting process hazards analyses as part of their good management practices. This handbook explains the minimum requirements for PrHAs outlined in the PSM Rule. Nowhere have requirements been added beyond what is specifically required by the rule.

  4. Radiometric chemical analysis

    International Nuclear Information System (INIS)

    The radiometric method of analysis is noted for its sensitivity and its simplicity in both apparatus and procedure. A few inexpensive radioactive reagents permit the analysis of a wide variety of chemical elements and compounds. Any particular procedure is generally applicable over a very wide range of concentrations. It is potentially an analytical method of great industrial significance. Specific examples of analyses are cited to illustrate the potentialities of ordinary equipment. Apparatus specifically designed for radiometric chemistry may shorten the time required, and increase the precision and accuracy for routine analyses. A sensitive and convenient apparatus for the routine performance of radiometric chemical analysis is a special type of centrifuge which has been used in obtaining the data presented in this paper. The radioactivity of the solution is measured while the centrifuge is spinning. This device has been used as the basis for an automatic analyser for phosphate ion, programmed to follow a sequence of unknown sampling, reagent mixing, centrifugation, counting data presentation, and phosphate replenishment. This analyser can repeatedly measure phosphate-concentration in the range of 5 to 50 ppm with an accuracy of ±5%. (author)

  5. Chemical Analysis Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Uses state-of-the-art instrumentation for qualitative and quantitative analysis of organic and inorganic compounds, and biomolecules from gas, liquid, and...

  6. Microprocessors in automatic chemical analysis

    International Nuclear Information System (INIS)

    Application of microprocessors to programming and computing of solutions chemical analysis by a sequential technique is examined. Safety, performances reliability are compared to other methods. An example is given on uranium titration by spectrophotometry

  7. Chemical substructure analysis in toxicology

    International Nuclear Information System (INIS)

    A preliminary examination of chemical-substructure analysis (CSA) demonstrates the effective use of the Chemical Abstracts compound connectivity file in conjunction with the bibliographic file for relating chemical structures to biological activity. The importance of considering the role of metabolic intermediates under a variety of conditions is illustrated, suggesting structures that should be examined that may exhibit potential activity. This CSA technique, which utilizes existing large files accessible with online personal computers, is recommended for use as another tool in examining chemicals in drugs. 2 refs., 4 figs

  8. Chemical substructure analysis in toxicology

    Energy Technology Data Exchange (ETDEWEB)

    Beauchamp, R.O. Jr. [Center for Information on Toxicology and Environment, Raleigh, NC (United States)

    1990-12-31

    A preliminary examination of chemical-substructure analysis (CSA) demonstrates the effective use of the Chemical Abstracts compound connectivity file in conjunction with the bibliographic file for relating chemical structures to biological activity. The importance of considering the role of metabolic intermediates under a variety of conditions is illustrated, suggesting structures that should be examined that may exhibit potential activity. This CSA technique, which utilizes existing large files accessible with online personal computers, is recommended for use as another tool in examining chemicals in drugs. 2 refs., 4 figs.

  9. Chemical analysis by nuclear techniques

    International Nuclear Information System (INIS)

    This state art report consists of four parts, production of micro-particles, analysis of boron, alpha tracking method and development of neutron induced prompt gamma ray spectroscopy (NIPS) system. The various methods for the production of micro-paticles such as mechanical method, electrolysis method, chemical method, spray method were described in the first part. The second part contains sample treatment, separation and concentration, analytical method, and application of boron analysis. The third part contains characteristics of alpha track, track dectectors, pretreatment of sample, neutron irradiation, etching conditions for various detectors, observation of track on the detector, etc. The last part contains basic theory, neutron source, collimator, neutron shields, calibration of NIPS, and application of NIPS system

  10. Coulometry in quantitative chemical analysis and physico-chemical research

    International Nuclear Information System (INIS)

    Electroanalytical methods such as potentiometry, amperometry, coulometry and voltammetry are well established and routinely employed in quantitative chemical analysis as well as in chemical research. Coulometry is one of the most important electroanalytical techniques, which involves change in oxidation state of electro active species by heterogeneous electron transfer. In primary coulometric method, uranium is determined at mercury pool electrode and plutonium at platinum gauze electrode

  11. Chemical analysis of water in hydrogeology

    International Nuclear Information System (INIS)

    The aim of the monograph is to give complete information on the chemical analysis of water hydrogeology not only for the students program of Geology study (Bachelor degree study), Engineering Geology and Hydrogeology (Master's degree study) and Engineering Geology (doctoral level study), but also for students from other colleges and universities schools in Slovakia, as well as in the Czech Republic, dealing with the chemical composition of water and its quality, from different perspectives. The benefit would be for professionals with hydrogeological, water and environmental practices, who can find there all the necessary information about proper water sampling, the units used in the chemical analysis of water, expressing the proper chemical composition of water in its various parameters through classification of chemical composition of the water up to the basic features of physical chemistry at thermodynamic calculations and hydrogeochemical modelling.

  12. 40 CFR 761.253 - Chemical analysis.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Chemical analysis. 761.253 Section 761.253 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT... analysis. (a) Extract PCBs from the standard wipe sample collection medium and clean-up the extracted...

  13. Chemical analysis of high purity graphite

    International Nuclear Information System (INIS)

    The Sub-Committee on Chemical Analysis of Graphite was organized in April 1989, under the Committee on Chemical Analysis of Nuclear Fuels and Reactor Materials, JAERI. The Sub-Committee carried out collaborative analyses among eleven participating laboratories for the certification of the Certified Reference Materials (CRMs), JAERI-G5 and G6, after developing and evaluating analytical methods during the period of September 1989 to March 1992. The certified values were given for ash, boron and silicon in the CRM based on the collaborative analysis. The values for ten elements (Al, Ca, Cr, Fe, Mg, Mo, Ni, Sr, Ti, V) were not certified, but given for information. Preparation, homogeneity testing and chemical analyses for certification of reference materials were described in this paper. (author) 52 refs

  14. Spectroscopic chemical analysis methods and apparatus

    Science.gov (United States)

    Hug, William F. (Inventor); Reid, Ray D. (Inventor); Bhartia, Rohit (Inventor)

    2013-01-01

    Spectroscopic chemical analysis methods and apparatus are disclosed which employ deep ultraviolet (e.g. in the 200 nm to 300 nm spectral range) electron beam pumped wide bandgap semiconductor lasers, incoherent wide bandgap semiconductor light emitting devices, and hollow cathode metal ion lasers to perform non-contact, non-invasive detection of unknown chemical analytes. These deep ultraviolet sources enable dramatic size, weight and power consumption reductions of chemical analysis instruments. Chemical analysis instruments employed in some embodiments include capillary and gel plane electrophoresis, capillary electrochromatography, high performance liquid chromatography, flow cytometry, flow cells for liquids and aerosols, and surface detection instruments. In some embodiments, Raman spectroscopic detection methods and apparatus use ultra-narrow-band angle tuning filters, acousto-optic tuning filters, and temperature tuned filters to enable ultra-miniature analyzers for chemical identification. In some embodiments Raman analysis is conducted along with photoluminescence spectroscopy (i.e. fluorescence and/or phosphorescence spectroscopy) to provide high levels of sensitivity and specificity in the same instrument.

  15. Service activities of chemical analysis division

    International Nuclear Information System (INIS)

    Progress of the Division during the year of 1988 was described on the service activities for various R and D projects carrying out in the Institute, for the fuel fabrication and conversion plant, and for the post-irradiation examination facility. Relevant analytical methodologies developed for the chemical analysis of an irradiated fuel, safeguards chemical analysis, and pool water monitoring were included such as chromatographic separation of lanthanides, polarographic determination of dissolved oxygen in water, and automation on potentiometric titration of uranium. Some of the laboratory manuals revised were also included in this progress report. (Author)

  16. Entropy generation reduction through chemical pinch analysis

    International Nuclear Information System (INIS)

    The pinch analysis (PA) concept emerged, late '80s, as one of the methods to address the energy management in the new era of sustainable development. It was derived from combined first and second law analysis, as a technique ensuring a better thermal integration, aiming the minimization of entropy production or, equivalently, exergy destruction by heat exchanger networks (HEN). Although its ascendance from the second law analysis is questionable, the PA reveals as a widespread tool, nowadays, helping in energy savings mostly through a more rational use of utilities. Unfortunately, as principal downside, one should be aware that the global minimum entropy production is seldom attained, since the PA does not tackle the whole plant letting aside the chemical reactors or separation trains. The chemical reactor network (CRN) is responsible for large amounts of entropy generation (exergy losses), mainly due to the combined composition and temperature change. The chemical pinch analysis (CPA) concept focuses on, simultaneously, the entropy generation reduction of both CRN and HEN, while keeping the state and working parameters of the plant in the range of industrial interest. The fundamental idea of CPA is to include the CRN (through the chemical reaction heat developed in reactors) into the HEN and to submit this extended system to the PA. This is accomplished by replacing the chemical reactor with a virtual heat exchanger system producing the same amount of entropy. For an endothermic non-adiabatic chemical reactor, the (stepwise infinitesimal) supply heat δq flows from a source (an external/internal heater) to the stream undergoing the chemical transformation through the reactor, which in turn releases the heat of reaction ΔHR to a virtual cold stream flowing through a virtual cooler. For an exothermic non-adiabatic chemical reactor, the replacement is likewise, but the heat flows oppositely. Thus, in the practice of designing or retrofitting a flowsheet, in order to

  17. Chemical abundance analysis of 19 barium stars

    CERN Document Server

    Yang, G C; Spite, M; Chen, Y Q; Zhao, G; Zhang, B; Liu, G Q; Liu, Y J; Liu, N; Deng, L C; Spite, F; Hill, V; Zhang, C X

    2016-01-01

    We aim at deriving accurate atmospheric parameters and chemical abundances of 19 barium (Ba) stars, including both strong and mild Ba stars, based on the high signal-to-noise ratio and high resolution Echelle spectra obtained from the 2.16 m telescope at Xinglong station of National Astronomical Observatories, Chinese Academy of Sciences. The chemical abundances of the sample stars were obtained from an LTE, plane-parallel and line-blanketed atmospheric model by inputting the atmospheric parameters (effective temperatures, surface gravities, metallicity and microturbulent velocity) and equivalent widths of stellar absorption lines. These samples of Ba stars are giants indicated by atmospheric parameters, metallicities and kinematic analysis about UVW velocity. Chemical abundances of 17 elements were obtained for these Ba stars. Their light elements (O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn and Ni) are similar to the solar abundances. Our samples of Ba stars show obvious overabundances of neutron-capture (n-ca...

  18. Analysis of Chemical Technology Division waste streams

    International Nuclear Information System (INIS)

    This document is a summary of the sources, quantities, and characteristics of the wastes generated by the Chemical Technology Division (CTD) of the Oak Ridge National Laboratory. The major contributors of hazardous, mixed, and radioactive wastes in the CTD as of the writing of this document were the Chemical Development Section, the Isotopes Section, and the Process Development Section. The objectives of this report are to identify the sources and the summarize the quantities and characteristics of hazardous, mixed, gaseous, and solid and liquid radioactive wastes that are generated by the Chemical Technology Division (CTD) of the Oak Ridge National Laboratory (ORNL). This study was performed in support of the CTD waste-reduction program -- the goals of which are to reduce both the volume and hazard level of the waste generated by the division. Prior to the initiation of any specific waste-reduction projects, an understanding of the overall waste-generation system of CTD must be developed. Therefore, the general approach taken in this study is that of an overall CTD waste-systems analysis, which is a detailed presentation of the generation points and general characteristics of each waste stream in CTD. The goal of this analysis is to identify the primary waste generators in the division and determine the most beneficial areas to initiate waste-reduction projects. 4 refs., 4 figs., 13 tabs

  19. Chemical detection, identification, and analysis system

    International Nuclear Information System (INIS)

    The chemical detection, identification, and analysis system (CDIAS) has three major goals. The first is to display safety information regarding chemical environment before personnel entry. The second is to archive personnel exposure to the environment. Third, the system assists users in identifying the stage of a chemical process in progress and suggests safety precautions associated with that process. In addition to these major goals, the system must be sufficiently compact to provide transportability, and it must be extremely simple to use in order to keep user interaction at a minimum. The system created to meet these goals includes several pieces of hardware and the integration of four software packages. The hardware consists of a low-oxygen, carbon monoxide, explosives, and hydrogen sulfide detector; an ion mobility spectrometer for airborne vapor detection; and a COMPAQ 386/20 portable computer. The software modules are a graphics kernel, an expert system shell, a data-base management system, and an interface management system. A supervisory module developed using the interface management system coordinates the interaction of the other software components. The system determines the safety of the environment using conventional data acquisition and analysis techniques. The low-oxygen, carbon monoxide, hydrogen sulfide, explosives, and vapor detectors are monitored for hazardous levels, and warnings are issued accordingly

  20. VALIDATION GUIDELINES FOR LABORATORIES PERFORMING FORENSIC ANALYSIS OF CHEMICAL TERRORISM

    Science.gov (United States)

    The Scientific Working Group on Forensic Analysis of Chemical Terrorism (SWGFACT) has developed the following guidelines for laboratories engaged in the forensic analysis of chemical evidence associated with terrorism. This document provides a baseline framework and guidance for...

  1. Systems analysis of past, present, and future chemical terrorism scenarios.

    Energy Technology Data Exchange (ETDEWEB)

    Hoette, Trisha Marie

    2012-03-01

    Throughout history, as new chemical threats arose, strategies for the defense against chemical attacks have also evolved. As a part of an Early Career Laboratory Directed Research and Development project, a systems analysis of past, present, and future chemical terrorism scenarios was performed to understand how the chemical threats and attack strategies change over time. For the analysis, the difficulty in executing chemical attack was evaluated within a framework of three major scenario elements. First, historical examples of chemical terrorism were examined to determine how the use of chemical threats, versus other weapons, contributed to the successful execution of the attack. Using the same framework, the future of chemical terrorism was assessed with respect to the impact of globalization and new technologies. Finally, the efficacy of the current defenses against contemporary chemical terrorism was considered briefly. The results of this analysis justify the need for continued diligence in chemical defense.

  2. Principal Component Analysis on Chemical Abundances Spaces

    CERN Document Server

    Ting, Y S; Kobayashi, C; De Silva, G M; Bland-Hawthorn, J

    2011-01-01

    [Shortened] In preparation for the HERMES chemical tagging survey of about a million Galactic FGK stars, we estimate the number of independent dimensions of the space defined by the stellar chemical element abundances [X/Fe]. [...] We explore abundances in several environments, including solar neighbourhood thin/thick disk stars, halo metal-poor stars, globular clusters, open clusters, the Large Magellanic Cloud and the Fornax dwarf spheroidal galaxy. [...] We find that, especially at low metallicity, the production of r-process elements is likely to be associated with the production of alpha-elements. This may support the core-collapse supernovae as the r-process site. We also verify the over-abundances of light s-process elements at low metallicity, and find that the relative contribution decreases at higher metallicity, which suggests that this lighter elements primary process may be associated with massive stars. [...] Our analysis reveals two types of core-collapse supernovae: one produces mainly alpha-e...

  3. Possibilities of Moessbauer spectroscopy for chemical analysis

    International Nuclear Information System (INIS)

    Full text: The Moessbauer spectroscopy technique belongs to few methods of defining the phase state or crystallographic sites of a substance. The Moessbauer spectra bear information on various hyperfine interactions, many of which are indirectly related to the chemical nature of the Moessbauer atom and its nearest environment. Determination of the parameters of hyperfine interactions that can be extracted from Moessbauer spectra and used for qualitative analysis is a routine task. In the present work, we studied the influence of various factors on experimental errors encountered in quantitatively defining the phase composition or site populations of the substance under study, such as the measurements geometry, Lamb-Moessbauer coefficients, absorber thickness, efficiency and dead time of the detection system and spectral line shape. The absolute f measurements were made using the 'black' absorber method. Moessbauer measurements were carried out with carefully controlled background intensities, since the accuracy of f evaluation directly depends on the measurement of the background. The influence of a non-uniformity of samples on the results of the quantitative analysis is discussed. The data analysis was divided into two parts: removal of instrumental artifacts by folding and baseline correction and deconvolution to extract the hyperfine parameters of individual local environments. In our approach, calibration graphs were drawn by measuring the spectra of a series of analogous samples having different known concentrations. For the same purpose, the internal standard method was also used. Experimental data are presented for phase analyses of different samples. (author)

  4. Advanced development in chemical analysis of Cordyceps.

    Science.gov (United States)

    Zhao, J; Xie, J; Wang, L Y; Li, S P

    2014-01-01

    Cordyceps sinensis, also called DongChongXiaCao (winter worm summer grass) in Chinese, is a well-known and valued traditional Chinese medicine. In 2006, we wrote a review for discussing the markers and analytical methods in quality control of Cordyceps (J. Pharm. Biomed. Anal. 41 (2006) 1571-1584). Since then this review has been cited by others for more than 60 times, which suggested that scientists have great interest in this special herbal material. Actually, the number of publications related to Cordyceps after 2006 is about 2-fold of that in two decades before 2006 according to the data from Web of Science. Therefore, it is necessary to review and discuss the advanced development in chemical analysis of Cordyceps since then. PMID:23688494

  5. Chemical abundance analysis of 19 barium stars

    Science.gov (United States)

    Yang, Guo-Chao; Liang, Yan-Chun; Spite, Monique; Chen, Yu-Qin; Zhao, Gang; Zhang, Bo; Liu, Guo-Qing; Liu, Yu-Juan; Liu, Nian; Deng, Li-Cai; Spite, Francois; Hill, Vanessa; Zhang, Cai-Xia

    2016-01-01

    We aim at deriving accurate atmospheric parameters and chemical abundances of 19 barium (Ba) stars, including both strong and mild Ba stars, based on the high signal-to-noise ratio and high resolution Echelle spectra obtained from the 2.16 m telescope at Xinglong station of National Astronomical Observatories, Chinese Academy of Sciences. The chemical abundances of the sample stars were obtained from an LTE, plane-parallel and line-blanketed atmospheric model by inputting the atmospheric parameters (effective temperatures Teff, surface gravities log g, metallicity [Fe/H] and microturbulence velocity ξt) and equivalent widths of stellar absorption lines. These samples of Ba stars are giants as indicated by atmospheric parameters, metallicities and kinematic analysis about UVW velocity. Chemical abundances of 17 elements were obtained for these Ba stars. Their Na, Al, α- and iron-peak elements (O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Ni) are similar to the solar abundances. Our samples of Ba stars show obvious overabundances of neutron-capture (n-capture) process elements relative to the Sun. Their median abundances of [Ba/Fe], [La/Fe] and [Eu/Fe] are 0.54, 0.65 and 0.40, respectively. The Y I and Zr I abundances are lower than Ba, La and Eu, but higher than the α- and iron-peak elements for the strong Ba stars and similar to the iron-peak elements for the mild stars. There exists a positive correlation between Ba intensity and [Ba/Fe]. For the n-capture elements (Y, Zr, Ba, La), there is an anti-correlation between their [X/Fe] and [Fe/H]. We identify nine of our sample stars as strong Ba stars with [Ba/Fe] >0.6 where seven of them have Ba intensity Ba=2-5, one has Ba=1.5 and another one has Ba=1.0. The remaining ten stars are classified as mild Ba stars with 0.17<[Ba/Fe] <0.54.

  6. Spectroscopic Chemical Analysis Methods and Apparatus

    Science.gov (United States)

    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

  7. Hybrid chemical and nondestructive-analysis technique

    Energy Technology Data Exchange (ETDEWEB)

    Hsue, S.T.; Marsh, S.F.; Marks, T.

    1982-01-01

    A hybrid chemical/NDA technique has been applied at the Los Alamos National Laboratory to the assay of plutonium in ion-exchange effluents. Typical effluent solutions contain low concentrations of plutonium and high concentrations of americium. A simple trioctylphosphine oxide (TOPO) separation can remove 99.9% of the americium. The organic phase that contains the separated plutonium can be accurately assayed by monitoring the uranium L x-ray intensities.

  8. Hybrid chemical and nondestructive analysis technique

    International Nuclear Information System (INIS)

    A hybrid chemical/NDA technique has been applied at the Los Alamos National Laboratory to the assay of plutonium in ion-exchange effluents. Typical effluent solutions contain low concentrations of plutonium and high concentrations of americium. A simple trioctylphosphine oxide (TOPO) separation can remove 99.9% of the americium. The organic phase that contains the separated plutonium can be accurately assayed by monitoring the uranium L x-ray intensities

  9. EDXRF for non-destructive chemical analysis

    International Nuclear Information System (INIS)

    One of the non-destructive methods used for the identification and verification of metals is by the energy-dispersive X-ray fluorescence (EDXRF) technique. EDXRF analysis provides several important advantages such as simultaneous determination of the elements present, enable to analyse a very wide concentration range, fast analysis with no sample preparation. The paper shows how this technique is developed and applied in the identification and verification of different grades of stainless steels and also precious metals analysis. (Author)

  10. Chemical Diversity, Origin, and Analysis of Phycotoxins.

    Science.gov (United States)

    Rasmussen, Silas Anselm; Andersen, Aaron John Christian; Andersen, Nikolaj Gedsted; Nielsen, Kristian Fog; Hansen, Per Juel; Larsen, Thomas Ostenfeld

    2016-03-25

    Microalgae, particularly those from the lineage Dinoflagellata, are very well-known for their ability to produce phycotoxins that may accumulate in the marine food chain and eventually cause poisoning in humans. This includes toxins accumulating in shellfish, such as saxitoxin, okadaic acid, yessotoxins, azaspiracids, brevetoxins, and pinnatoxins. Other toxins, such as ciguatoxins and maitotoxins, accumulate in fish, where, as is the case for the latter compounds, they can be metabolized to even more toxic metabolites. On the other hand, much less is known about the chemical nature of compounds that are toxic to fish, the so-called ichthyotoxins. Despite numerous reports of algal blooms causing massive fish kills worldwide, only a few types of compounds, such as the karlotoxins, have been proven to be true ichthyotoxins. This review will highlight marine microalgae as the source of some of the most complex natural compounds known to mankind, with chemical structures that show no resemblance to what has been characterized from plants, fungi, or bacteria. In addition, it will summarize algal species known to be related to fish-killing blooms, but from which ichthyotoxins are yet to be characterized. PMID:26901085

  11. Chemical equilibrium analysis of dry hydrogen combustion

    International Nuclear Information System (INIS)

    The present work is based on a thermo-chemical equilibrium model for studying the effect of combustion of hydrogen during postulated accident scenarios in nuclear reactor containments. This model is based on the method of element potentials which seeks to minimize the free energy of the system. The condition on internal energy balance is imposed as a constraint during the minimization process. Another simplified model purely based on the internal energy balance has also been implemented to investigate the isolated impact of free energy and the conditions under which it becomes dominant. The two models have been used to extract final pressures for a wide range of initial conditions and mixture compositions that are typically found during accident scenarios. In the absence of hydrogen combustion experimental data, such models will become important for laying down a first estimate on the possible outcomes. (author)

  12. Chemical aspects of nuclear methods of analysis

    International Nuclear Information System (INIS)

    This final report includes papers which fall into three general areas: development of practical pre-analysis separation techniques, uranium/thorium separation from other elements for analytical and processing operations, and theory and mechanism of separation techniques. A separate abstract was prepared for each of the 9 papers

  13. Arrays in biological and chemical analysis

    DEFF Research Database (Denmark)

    Christensen, Claus Bo Vöge

    2002-01-01

    Recently a dramatic change has happened for biological and biochemical analysis. Originally developed as an academic massive parallel screening tool, industry has caught the idea as well of performing all kinds of assays in the new format of microarrays. From food manufacturers over water supply...

  14. Analysis of blood spots for polyfluoroalkyl chemicals

    International Nuclear Information System (INIS)

    Polyfluoroalkyl chemicals (PFCs) have been detected in humans, in the environment, and in ecosystems around the world. The potential for developmental and reproductive toxicities of some PFCs is of concern especially to children's health. In the United States, a sample of a baby's blood, called a 'dried blood spot' (DBS), is obtained from a heel stick within 48 h of a child's birth. DBS could be useful for assessing prenatal exposure to PFCs. We developed a method based on online solid phase extraction coupled with high performance liquid chromatography-isotope dilution tandem mass spectrometry for measuring four PFCs in DBS, perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate, perfluorooctanoate (PFOA), and perfluorononanoate. The analytical limits of detection using one whole DBS (∼75 μL of blood) were -1. To validate the method, we analyzed 98 DBS collected in May 2007 in the United States. PFOS and PFOA were detected in all DBS at concentrations in the low ng mL-1 range. These data suggest that DBS may be a suitable matrix for assessing perinatal exposure to PFCs, but additional information related to sampling and specimen storage is needed to demonstrate the utility of these measures for assessing exposure.

  15. Isotopes in chemical analysis for water management

    International Nuclear Information System (INIS)

    Surface or underground water circulations and interactions are more and more often studied with the help of geochemistry and more particularly by using isotopic tracers. These isotopic tracer techniques allow, in particular, to define for each system under study, the natural or anthropic origin of the chemical elements, their behaviour, their transport in the different compartments, the circulation schemes of deep fluids and their interaction with the surrounding rocks. This article presents: 1 - the isotopes: definition, measurements and uses (stable and instable isotopes, measurement means, some examples: stable isotopes of the water molecule, boron isotopes, sulfur and oxygen isotopes of sulfates, strontium isotopes, nitrogen isotopes of nitrates); 2 - isotopes and water cycle: atmospheric tracing (rainfall signal at the drainage basin scale and at the country scale, aerosols characterization in urban areas), management of alluvial aquifers, underground waters and origin of nitrogenous contaminations, underground and surface waters in the context of aquifer floods: the case of the Somme basin, underground waters at the basin scale: heterogeneities, interactions and management processes (stable isotopes of the water molecule, S and O isotopes of dissolved sulfates, strontium isotopes); 3 - conclusion. (J.S.)

  16. Controlling the accuracy of chemical analysis

    International Nuclear Information System (INIS)

    Most of the IAEA reference materials are certified in intercomparisons by calculation of the overall mean of reported laboratory mean values. IAEA certification is provided at ''A level'' (satisfactory, or high degree of confidence), or at ''B level'' (acceptable, or reasonable degree of confidence) sampling , storage and preliminary processing, use of reliable analytical methods, internal and external control of accuracy and reliability result in excellent certified reference materials for inorganic, geologic, environmental, biological and other quantitative analysis by means of conventional and nuclear methods. 34 refs, 4 figs, 3 tabs

  17. Chemical form analysis method of particulate nickel compounds

    International Nuclear Information System (INIS)

    Chemical form of nickel is metallic nickel, nickel oxide and nickel ferrite in the PWR primary chemistry condition. The distribution of chemical form depends on Ni/Fe ratio and chemistry condition, especially dissolved hydrogen concentration. Nickel is parent element of Co-58 and the chemical form is important for Co-58 generation. A method of chemical form analysis of nickel has been developed. This method uses the difference in dissolution characteristics of nickel compounds. Metallic nickel and others are separated by nitric acid, and others are divided to nickel oxide and nickel ferrite by oxalic acid. Some cruds in the primary coolant of a PWR were analyzed by using this method. The method is not complex and available at chemical laboratory in a nuclear power plant. (author)

  18. Airborne chemistry: acoustic levitation in chemical analysis.

    Science.gov (United States)

    Santesson, Sabina; Nilsson, Staffan

    2004-04-01

    This review with 60 references describes a unique path to miniaturisation, that is, the use of acoustic levitation in analytical and bioanalytical chemistry applications. Levitation of small volumes of sample by means of a levitation technique can be used as a way to avoid solid walls around the sample, thus circumventing the main problem of miniaturisation, the unfavourable surface-to-volume ratio. Different techniques for sample levitation have been developed and improved. Of the levitation techniques described, acoustic or ultrasonic levitation fulfils all requirements for analytical chemistry applications. This technique has previously been used to study properties of molten materials and the equilibrium shape()and stability of liquid drops. Temperature and mass transfer in levitated drops have also been described, as have crystallisation and microgravity applications. The airborne analytical system described here is equipped with different and exchangeable remote detection systems. The levitated drops are normally in the 100 nL-2 microL volume range and additions to the levitated drop can be made in the pL-volume range. The use of levitated drops in analytical and bioanalytical chemistry offers several benefits. Several remote detection systems are compatible with acoustic levitation, including fluorescence imaging detection, right angle light scattering, Raman spectroscopy, and X-ray diffraction. Applications include liquid/liquid extractions, solvent exchange, analyte enrichment, single-cell analysis, cell-cell communication studies, precipitation screening of proteins to establish nucleation conditions, and crystallisation of proteins and pharmaceuticals. PMID:14762640

  19. Appendix C. Collection of Samples for Chemical Agent Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Koester, C; Thompson, C; Doerr, T; Scripsick, R

    2005-09-23

    This chapter describes procedures for the collection and analysis of samples of various matrices for the purpose of determining the presence of chemical agents in a civilian setting. This appendix is intended to provide the reader with sufficient information to make informed decisions about the sampling and analysis process and to suggest analytical strategies that might be implemented by the scientists performing sampling and analysis. This appendix is not intended to be used as a standard operating procedure to provide detailed instructions as to how trained scientists should handle samples. Chemical agents can be classified by their physical and chemical properties. Table 1 lists the chemical agents considered by this report. In selecting sampling and analysis methods, we have considered procedures proposed by the Organization for Prohibition of Chemical Weapons (OPCW), the U. S. Environmental Protection Agency (EPA), and peer-reviewed scientific literature. EPA analytical methods are good resources describing issues of quality assurance with respect to chain-of-custody, sample handling, and quality control requirements.

  20. Terahertz Chemical Analysis of Exhaled Human Breath - Broad Essay of Chemicals

    Science.gov (United States)

    Branco, Daniela R.; Fosnight, Alyssa M.; Thomas, Jessica R.; Medvedev, Ivan R.

    2013-06-01

    Approximately 3000 chemicals are thought to be present in human breath. Of these chemicals, many are considered typical of exhaled air. Yet, others can allude to different disease pathologies. The detection of chemicals in breath could have many practical purposes in medicine and provide a noninvasive means of diagnostics. We have previously reported on detection of ethanol, methanol, and acetone in exhaled human breath using a novel sub-millimeter/THz spectroscopic approach. This paper reports on our most recent study. A tentative list has been made of approximately 20 chemicals previously found in breath using other methods. Though many of these chemicals are only expressed in samples from donors with certain pathologies, at the time of this submission we are able to detect and quantitatively measure acetaldehyde and dimethyl sulfide in the breath of several healthy donors. Additional tentatively identified chemicals have been seen using this approach. This presentation will explain our experimental procedures and present our most recent results in THz breath analysis. Prospects, challenges and future plans will be outlined and discussed.

  1. Gradient Bundle Analysis: A Full Topological Approach to Chemical Bonding

    CERN Document Server

    Morgenstern, Amanda

    2016-01-01

    The "chemical bond" is a central concept in molecular sciences, but there is no consensus as to what a bond actually is. Therefore, a variety of bonding models have been developed, each defining the structure of molecules in a different manner with the goal of explaining and predicting chemical properties. This thesis describes the initial development of gradient bundle analysis (GBA), a chemical bonding model that creates a high resolution picture of chemical interactions within the charge density framework. GBA is based on concepts from the quantum theory of atoms in molecules (QTAIM), but uses a more complete picture of the topology and geometry of the electron charge density to understand and predict bonding interactions. Gradient bundles are defined as volumes bounded by zero-flux surfaces (ZFSs) in the gradient of the charge density with well-defined energies. The structure of gradient bundles provides an avenue for detecting the locations of valence electrons, which correspond to reactive regions in a ...

  2. Surface chemical composition analysis of heat-treated bamboo

    Science.gov (United States)

    Meng, Fan-dan; Yu, Yang-lun; Zhang, Ya-mei; Yu, Wen-ji; Gao, Jian-min

    2016-05-01

    In this study, the effect of heat treatment on the chemical composition of bamboo slivers was studied. The chemical properties of the samples were examined by chemical analysis. Results showed a decrease in the contents of holocellulose and α-cellulose, as well as an increase in the contents of lignin and extractives. Changes in the chemical structure of bamboo components were analyzed by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). FTIR spectroscopy results indicated that hemicellulose contents decrease, whereas lignin contents increase after heat treatment. Ester formation linked to lignin decreased the hygroscopicity of the bamboo samples and consequently improved their dimensional stability and durability. XPS spectroscopy results showed that hemicelluloses and celluloses are relatively more sensitive to the heating process than lignin. As a consequence, hemicellulose and cellulose contents decreased, whereas lignin contents increased during heat treatment. The results obtained in this study provide useful information for the future utilization of heat-treated bamboo.

  3. Method for fractional solid-waste sampling and chemical analysis

    DEFF Research Database (Denmark)

    Riber, Christian; Rodushkin, I.; Spliid, Henrik;

    2007-01-01

    Chemical characterization of solid waste is a demanding task due to the heterogeneity of the waste. This article describes how 45 material fractions hand-sorted from Danish household waste were subsampled and prepared for chemical analysis of 61 substances. All material fractions were subject to...... repeated particle-size reduction, mixing, and mass reduction until a sufficiently small but representative sample was obtained for digestion prior to chemical analysis. The waste-fraction samples were digested according to their properties for maximum recognition of all the studied substances. By combining...... four subsampling methods and five digestion methods, paying attention to the heterogeneity and the material characteristics of the waste fractions, it was possible to determine 61 substances with low detection limits, reasonable variance, and high accuracy. For most of the substances of environmental...

  4. The Impact of Flow Injection on Modern Chemical Analysis

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    There is no doubt that Flow Injection Analysis (FIA) has had a profound impact on the ways and means that modern analytical chemical procedures are performed. This is amply reflected in the voluminous scientific literature, which by the middle of 2004 passed more than 14,500 FIA-publications in...

  5. Bark chemical analysis explains selective bark damage by rodents

    Czech Academy of Sciences Publication Activity Database

    Heroldová, Marta; Jánová, Eva; Suchomel, J.; Purchart, L.; Homolka, Miloslav

    2009-01-01

    Roč. 2, č. 2 (2009), s. 137-140. ISSN 1803-2451 R&D Projects: GA MZe QH72075 Institutional research plan: CEZ:AV0Z60930519 Keywords : bark damage * bark selection * bark chemical analysis * rowan * beech * spruce * mountain forest regeneration Subject RIV: GK - Forest ry

  6. Integrated polymer waveguides for absorbance detection in chemical analysis systems

    DEFF Research Database (Denmark)

    Mogensen, Klaus Bo; El-Ali, Jamil; Wolff, Anders;

    2003-01-01

    A chemical analysis system for absorbance detection with integrated polymer waveguides is reported for the first time. The fabrication procedure relies on structuring of a single layer of the photoresist SU-8, so both the microfluidic channel network and the optical components, which include planar...

  7. Trends in Indian Patent Filing in Chemical Sciences: An Analysis

    Directory of Open Access Journals (Sweden)

    N.B. Dahibhate,

    2012-05-01

    Full Text Available The paper analyses the trends in Indian patents filed in the area of chemical sciences during 1995 to2008. It highlights the importance of patent literature in scientific developments and global trends in patentfilings. A result of Indian patent filing analysis indicated that filing in India is increasing in the past few yearsand many public and private organisations are filing patents in India and in other countries for protecting theinventions. Among India patent filing activities, chemical and pharmaceutical sciences are the prominent areas.Individual inventors and assignees from private and public organisations are filing patents, but in India, Councilof Scientific & Industrial Research (CSIR is leading patent filer.

  8. An Extended Algorithm of Flexibility Analysis in Chemical Engineering Processes

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An extended algorithm of flexibility analysis with a local adjusting method for flexibility region of chemical processes, which is based on the active constraint strategy, is proposed, which fully exploits the flexibility region of the process system operation. The hyperrectangular flexibility region determined by the extended algorithm is larger than that calculated by the previous algorithms. The limitation of the proposed algorithm due to imperfect convexity and its corresponding verification measure are also discussed. Both numerical and actual chemical process examples are presented to demonstrate the effectiveness of the new algorithm.

  9. Chemical Cytometry: Fluorescence-Based Single-Cell Analysis

    Science.gov (United States)

    Cohen, Daniella; Dickerson, Jane A.; Whitmore, Colin D.; Turner, Emily H.; Palcic, Monica M.; Hindsgaul, Ole; Dovichi, Norman J.

    2008-07-01

    Cytometry deals with the analysis of the composition of single cells. Flow and image cytometry employ antibody-based stains to characterize a handful of components in single cells. Chemical cytometry, in contrast, employs a suite of powerful analytical tools to characterize a large number of components. Tools have been developed to characterize nucleic acids, proteins, and metabolites in single cells. Whereas nucleic acid analysis employs powerful polymerase chain reaction-based amplification techniques, protein and metabolite analysis tends to employ capillary electrophoresis separation and ultrasensitive laser-induced fluorescence detection. It is now possible to detect yoctomole amounts of many analytes in single cells.

  10. Chemical analysis of thin films at Sandia National Laboratories

    International Nuclear Information System (INIS)

    The characterization of thin films produced by chemical and physical vapor deposition requires special analytical techniques. When the average compositions of the films are required, dissolution of the thin films and measurement of the concentrations of the solubilized species is the appropriate analytical approach. In this report techniques for the wet chemical analysis of thin films of Si:Al, P2O5:SiO2, B2O3:SiO2, TiB/sub x/ and TaB/sub x/ are described. The analyses are complicated by the small total quantities of these analytes present in the films, the refractory characters of these analytes, and the possibility of interferences from the substrates on which the films are deposited. Etching conditions are described which dissolve the thin films without introducing interferences from the substrates. A chemical amplification technique and inductively coupled plasma atomic emission spectrometry are shown to provide the sensitivity required to measure the small total quantities (micrograms to milligrams) of analytes present. Also the chemical analysis data has been used to calibrate normal infrared absorption spectroscopy to give fast estimates of the phosphorus and/or boron dopant levels in thin SiO2 films

  11. All-Russia conference on chemical analysis of substances and materials. Abstracts of reports

    International Nuclear Information System (INIS)

    Collection contains abstracts of reports on chemical analysis of foods, drugs, environmental materials. Methods of chemical analysis used in such regions as chemical control in agriculture, criminology, art and archaeology, biotechnology, geology, chemistry and petrochemistry, metallurgy, metrology are presented. Theoretical, methodological and applied aspects of chemical analysis are considered

  12. Analysis of the chemical equilibrium of combustion at constant volume

    OpenAIRE

    Marius BREBENEL

    2014-01-01

    Determining the composition of a mixture of combustion gases at a given temperature is based on chemical equilibrium, when the equilibrium constants are calculated on the assumption of constant pressure and temperature. In this paper, an analysis of changes occurring when combustion takes place at constant volume is presented, deriving a specific formula of the equilibrium constant. The simple reaction of carbon combustion in pure oxygen in both cases (constant pressure and constant ...

  13. Development of microfluidic devices for chemical analysis and fluid handling

    OpenAIRE

    Egidi, Giovanni; De Rooij, Nicolas F

    2004-01-01

    Miniaturization of chemical analysis and synthesis systems improve throughput, performance and accessibility, and lead to significantly reduced costs. In this work are described several components that find place in the process of miniaturization. This work is developed in the frame of the project CREAM (Cartridges with molecularly imprinted Recognition Elements for Antibiotic residues Monitoring in Milk). Antibiotics are widely used to treat cows' diseases, and traces can be found in milk so...

  14. Device for high spatial resolution chemical analysis of a sample and method of high spatial resolution chemical analysis

    Science.gov (United States)

    Van Berkel, Gary J.

    2015-10-06

    A system and method for analyzing a chemical composition of a specimen are described. The system can include at least one pin; a sampling device configured to contact a liquid with a specimen on the at least one pin to form a testing solution; and a stepper mechanism configured to move the at least one pin and the sampling device relative to one another. The system can also include an analytical instrument for determining a chemical composition of the specimen from the testing solution. In particular, the systems and methods described herein enable chemical analysis of specimens, such as tissue, to be evaluated in a manner that the spatial-resolution is limited by the size of the pins used to obtain tissue samples, not the size of the sampling device used to solubilize the samples coupled to the pins.

  15. Cluster analysis to evaluate stable chemical elements and physical-chemical parameters behavior on uranium mining waste

    International Nuclear Information System (INIS)

    The Ore Treating Unit (UTM, in portuguese) is a deactivated uranium mine. A cluster analysis was used to evaluate the behavior of stable chemical elements and physical-chemical parameters in their effluents. The utilization of the cluster analysis proved itself effective in the assessment, allowing the identification of groups of chemical elements, physical-chemical parameters and their joint analysis (elements and parameters). As a result we may assert, based on data analysis, that there is a strong link between calcium and magnesium and between aluminum and rare-earth oxides on UTM's effluents. Sulphate was also identified as strongly linked to total and dissolved solids, and those to electrical conductivity. There were other associations, but not so strongly linked. Further gathering, to seasonal evaluation, are required in order to confirm those analysis. Additional statistical analysis (factor analysis) must be used to try to identify the origin of the identified groups on this analysis. (author)

  16. Analysis of the stochastic excitability in the flow chemical reactor

    Energy Technology Data Exchange (ETDEWEB)

    Bashkirtseva, Irina [Ural Federal University, Lenina, 51, Ekaterinburg, 620000 (Russian Federation)

    2015-11-30

    A dynamic model of the thermochemical process in the flow reactor is considered. We study an influence of the random disturbances on the stationary regime of this model. A phenomenon of noise-induced excitability is demonstrated. For the analysis of this phenomenon, a constructive technique based on the stochastic sensitivity functions and confidence domains is applied. It is shown how elaborated technique can be used for the probabilistic analysis of the generation of mixed-mode stochastic oscillations in the flow chemical reactor.

  17. Methods of remote surface chemical analysis for asteroid missions

    International Nuclear Information System (INIS)

    Different remote sensing methods are discussed which can be applied to investigate the chemical composition of minor bodies of the Solar System. The secondary-ion method, remote laser mass-analysis and electron beam induced X-ray emission analysis are treated in detail. Relative advantages of these techniques are analyzed. The physical limitation of the methods: effects of solar magnetic field and solar wind on the secondary-ion and laser methods and the effect of electrostatic potential of the space apparatus on the ion and electron beam methods are described. First laboratory results of remote laser method are given. (D.Gy.)

  18. Electrochemical approaches for chemical and biological analysis on Mars

    Science.gov (United States)

    Kounaves, Samuel P.

    2003-01-01

    Obtaining in situ chemical data from planetary bodies such as Mars or Europa can present significant challenges. The one analytical technique that has many of the requisite characteristics to meet such a challenge is electroanalysis. Described here are three electroanalytical devices designed for in situ geochemical and biological analysis on Mars. The Mars Environmental Compatibility Assessment (MECA) was built and flight qualified for the now cancelled NASA Mars 2001 Lander. Part of MECA consisted of four "cells" containing arrays of electrochemical based sensors for measuring the ionic species in soil samples. A next-generation MECA, the Robotic Chemical Analysis Laboratory (RCAL), uses a carousel-type system to allow for greater customization of analytical procedures. A second instrument, proposed as part of the 2007 CryoScout mission, consists of a flow-through inorganic chemical analyzer (MICA). CryoScout is a torpedo-like device designed for subsurface investigation of the stratigraphic climate record embedded in Mars' north polar cap. As the CryoScout melts its way through the ice cap, MICA will collect and analyze the meltwater for a variety of inorganics and chemical parameters. By analyzing the chemistry locked in the layers of dust, salt, and ice, geologists will be able to determine the recent history of climate, water, and atmosphere on Mars and link it to the past. Finally, electroanalysis shows its abilities in the detection of possible microorganism on Mars or elsewhere in the solar system. To identify an unknown microorganism, one that may not even use Earth-type biochemistry, requires a detection scheme which makes minimal assumptions and looks for the most general features. Recent work has demonstrated that the use of an array of electrochemical sensors which monitors the changes in a solution via electrical conductivity, pH, and ion selective electrodes, can be used to detect minute chemical perturbations caused by the growth of bacteria and

  19. Tip enhanced Raman scattering: plasmonic enhancements for nanoscale chemical analysis

    Science.gov (United States)

    Schultz, Zachary D.; Marr, James M.; Wang, Hao

    2014-04-01

    Tip enhanced Raman scattering (TERS) is an emerging technique that uses a metalized scanning probe microscope tip to spatially localize electric fields that enhances Raman scattering enabling chemical imaging on nanometer dimensions. Arising from the same principles as surface enhanced Raman scattering (SERS), TERS offers unique advantages associated with controling the size, shape, and location of the enhancing nanostructure. In this article we discuss the correlations between current understanding of SERS and how this relates to TERS, as well as how TERS provides new understanding and insights. The relationship between plasmon resonances and Raman enhancements is emphasized as the key to obtaining optimal TERS results. Applications of TERS, including chemical analysis of carbon nanotubes, organic molecules, inorganic crystals, nucleic acids, proteins, cells and organisms, are used to illustrate the information that can be gained. Under ideal conditions TERS is capable of single molecule sensitivity and sub-nanometer spatial resolution. The ability to control plasmonic enhancements for chemical analysis suggests new experiments and opportunities to understand molecular composition and interactions on the nanoscale.

  20. Chemical Bond Analysis of Single Crystal Growth of Magnesium Oxide

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Starting from the crystallographic structure of magnesium oxide (MgO), both the chemical bond model of solids and Pauling's third rule (polyhedral sharing rule) were employed to quantitatively analyze the chemical bonding structure of constituent atoms and single crystal growth. Our analytical results show that MgO single crystals prefer to grow along the direction and the growth rate of the {100} plane is the slowest one. Therefore, the results show that the {100} plane of MgO crystals can be the ultimate morphology face, which is in a good agreement with our previous experimental results. The study indicate that the structure analysis is an effective tool to control the single-crystal growth.

  1. Microarray Technology for Major Chemical Contaminants Analysis in Food: Current Status and Prospects

    OpenAIRE

    Xiaoxia Ding; Wen Zhang; Xiaofeng Hu; Qi Zhang; Peiwu Li; Zhaowei Zhang

    2012-01-01

    Chemical contaminants in food have caused serious health issues in both humans and animals. Microarray technology is an advanced technique suitable for the analysis of chemical contaminates. In particular, immuno-microarray approach is one of the most promising methods for chemical contaminants analysis. The use of microarrays for the analysis of chemical contaminants is the subject of this review. Fabrication strategies and detection methods for chemical contaminants are discussed in detail....

  2. Comparison of descriptive sensory analysis and chemical analysis for oxidative changes in milk

    DEFF Research Database (Denmark)

    Hedegaard, R V; Kristensen, D; Nielsen, Jacob Holm;

    2006-01-01

    products. The milk samples were evaluated in parallel by descriptive sensory analysis by a trained panel, and the correlation between the chemical analysis and the descriptive sensory analysis was evaluated. The fatty acid composition of the 3 types of milk was found to influence the oxidative and......Oxidation in 3 types of bovine milk with different fatty acid profiles obtained through manipulation of feed was evaluated by analytical methods quantifying the content of potential antioxidants, the tendency of formation of free radicals, and the accumulation of primary and secondary oxidation...... lipolytic changes occurring in the milk during chill storage for 4 d. Sensory analysis and chemical analysis showed high correlation between the typical descriptors for oxidation such as cardboard, metallic taste, and boiled milk and specific chemical markers for oxidation such as hexanal. Notably, primary...

  3. QUALITY ASSURANCE GUIDELINES FOR LABORATORIES PERFORMING FORENSIC ANALYSIS OF CHEMICAL TERRORISM

    Science.gov (United States)

    The Scientific Working Group on Forensic Analysis of Chemical Terrorism (SWGFACT) has developed the following quality assurance guidelines to provide laboratories engaged in forensic analysis of chemical evidence associated with terrorism a framework to implement a quality assura...

  4. Analysis of the chemical equilibrium of combustion at constant volume

    Directory of Open Access Journals (Sweden)

    Marius BREBENEL

    2014-04-01

    Full Text Available Determining the composition of a mixture of combustion gases at a given temperature is based on chemical equilibrium, when the equilibrium constants are calculated on the assumption of constant pressure and temperature. In this paper, an analysis of changes occurring when combustion takes place at constant volume is presented, deriving a specific formula of the equilibrium constant. The simple reaction of carbon combustion in pure oxygen in both cases (constant pressure and constant volume is next considered as example of application, observing the changes occurring in the composition of the combustion gases depending on temperature.

  5. Probabilistic Approach to Risk Analysis of Chemical Spills at Sea

    Institute of Scientific and Technical Information of China (English)

    Magda Bogalecka; Krzysztof Kolowrocki

    2006-01-01

    Risk analysis of chemical spills at sea and their consequences for sea environment are discussed. Mutual interactions between the process of the sea accident initiating events, the process of the sea environment threats, and the process of the sea environment degradation are investigated. To describe these three particular processes, the separate semi-Markov models are built. Furthermore, these models are jointed into one general model of these processes interactions.Moreover, some comments on the method for statistical identification of the considered models are proposed.

  6. Chemical phase analysis of seed mediated synthesized anisotropic silver nanoparticles

    Science.gov (United States)

    Bharti, Amardeep; Singh, Suman; Singla, M. L.; Goyal, Navdeep

    2015-08-01

    Noble-metal nanoparticles are of great interest because of its broad applications almost in every stream (i.e. biology, chemistry and engineering) due to their unique size/shape dependant properties. In this paper, chemical phase of seed mediated synthesized anisotropic silver nanoparticle (AgNPs) has been investigated via fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). These nanaoparticles were synthesized by seed-growth method controlled by urea and dextrose results to highly stable 12-20 nm particle size revealed by zeta potential and transmission electron microscopy (TEM).

  7. Chemical phase analysis of seed mediated synthesized anisotropic silver nanoparticles

    International Nuclear Information System (INIS)

    Noble-metal nanoparticles are of great interest because of its broad applications almost in every stream (i.e. biology, chemistry and engineering) due to their unique size/shape dependant properties. In this paper, chemical phase of seed mediated synthesized anisotropic silver nanoparticle (AgNPs) has been investigated via fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). These nanaoparticles were synthesized by seed-growth method controlled by urea and dextrose results to highly stable 12-20 nm particle size revealed by zeta potential and transmission electron microscopy (TEM)

  8. Physcio chemical analysis of browning inhibitors treated solanum turberosum powder

    International Nuclear Information System (INIS)

    White potatoes (Solanum turberosum) were procured from agriculture Research Institute Tarnab Farm Peshawar to use for the preparation of potato powder. The process involves sorting. Washing, peeling slicing, blanching, treating with poly phenol oxidase inhibitors, dehydration, grinding and packing. All these parameters used in process were standardized. Chemical analysis of fresh potato and potato powder were carried out. Microbiological examination, functional properties and storage life studies of the potato powder were also performed. The product prepared by drying in cabinet dryer at 55 C for 7 hours was off white colour potatoes chips which was grinded to make off white potato powder. The potato powder possessed taste and texture. (author)

  9. Crystal-Chemical Analysis of Soil at Rocknest, Gale Crater

    Science.gov (United States)

    Morrison, S. M.; Downs, R. T.; Blake, D. F.; Bish, D. L.; Ming, D. W.; Morris, R. V.; Yen, A. S.; Chipera, S. J.; Treiman, A. H.; Vaniman, D. T.; Gellert, R.; Achilles, C. N.; Rampe, E. B.; Bristow, T. F.; Crisp, J. A.; Sarrazin, P. C.; DesMarais, D. J.; Morookian, J. M.; Anderson, R. C.

    2013-01-01

    The CheMin instrument on the Mars Science Laboratory rover Curiosity performed X-ray diffraction analysis on Martian soil [1] at Rocknest in Gale Crater. In particular, crystalline phases from scoop 5 were identified and analyzed with the Rietveld method [2]. Refined unit-cell parameters are reported in Table 1. Comparing these unit-cell parameters with those in the literature provides an estimate of the chemical composition of the crystalline phases. For instance, Fig. 1 shows the Mg-content of Fa-Fo olivine as a function of the b unit-cell parameter using literature data. Our refined b parameter is indicated by the black triangle.

  10. Microbiological and chemical analysis of land snails commercialised in Sicily

    Directory of Open Access Journals (Sweden)

    Antonello Cicero

    2015-05-01

    Full Text Available In this study 160 samples of snails belonging to the species Helix aspersa maxima and Helix aspersa muller were examined for chemical and microbiological analysis. Samples came from Greece and Poland. Results showed mean concentration of cadmium (0.35±0.036 mg/kg and lead (0.05±0.013 mg/kg much higher than the limit of detection. Mercury levels in both species were not detected. Microbiological analysis revealed the absence of Salmonella spp. and Clostridium spp. in both examined species. E. coli and K. oxytoca were observed in Helix aspersa maxima and Helix aspersa muller. Furthermore, one case of fungi positivity in samples of Helix aspersa muller was found. The reported investigations highlight the need to create and adopt a reference legislation to protect the health of consumers.

  11. Chemical analysis of Yemeni archaeological cheramics and the Egyptian enigma

    International Nuclear Information System (INIS)

    Archaeological reconnaissance in Yemen produced samples of mediaeval Islamic ceramics in a 100 km2 region. The ceramics dated from 700 A.d. to 1750 A.D. and initial research indicated that they were all locally made products. 12 types of ceramics were selected for sampling on the basis of stylistic decoration. Six laboratory samples of each type were subjected to neutron activation analysis for the short-lived isotope producing elements using the SLOWPOKE reactor at the University of Toronto. A comparison with Egyptian pottery was carried out. The statistical analysis conducted on the Yemeni and Egyptian pottery produced discrete differences in their elemental composition which the archaeologist and the chemical scientist might not otherwise recognise. It is concluded that artifacts must be analyzed with due respect given to the archeological context, the elemental chemistry, and sound statistical procedures. (author)

  12. Statistical sampling and chemical analysis of complex weapon components

    International Nuclear Information System (INIS)

    One of the waste streams generated by nuclear weapon dismantlement programs will be component ''hardware'', including complex electronic assemblies such as: radars, arming/fusing/firing systems, power sources, and use-control and safety systems. Sandia National Laboratories (SNL) has been the design and development laboratory for many of these components and will be responsible for their ultimate disposition. This disposition, whether it be reuse, material recycle, or disposal, will require some level of material characterization and analysis. Previous efforts at developing a process for segregation and characterization of hazardous materials in weapon components have been documented. This paper describes the results of recent activities undertaken in support of the Weapon Hardware Inventory Reduction Effort (WHIRE) at Sandia National Laboratories. These activities have been directed principally towards: The development of a statistically sound sampling plan for chemical analysis of weapon component materials; the development of a non-destructive analytical screening method for determining the Toxicity Characteristic of excess weapon hardware

  13. Chemical Analysis of Wastewater from Unconventional Drilling Operations

    Directory of Open Access Journals (Sweden)

    Jonathan B. Thacker

    2015-04-01

    Full Text Available Trillions of liters of wastewater from oil and gas extraction are generated annually in the US. The contribution from unconventional drilling operations (UDO, such as hydraulic fracturing, to this volume will likely continue to increase in the foreseeable future. The chemical content of wastewater from UDO varies with region, operator, and elapsed time after production begins. Detailed chemical analyses may be used to determine its content, select appropriate treatment options, and identify its source in cases of environmental contamination. In this study, one wastewater sample each from direct effluent, a disposal well, and a waste pit, all in West Texas, were analyzed by gas chromatography-mass spectrometry, inductively coupled plasma-optical emission spectroscopy, high performance liquid chromatography-high resolution mass spectrometry, high performance ion chromatography, total organic carbon/total nitrogen analysis, and pH and conductivity analysis. Several compounds known to compose hydraulic fracturing fluid were detected among two of the wastewater samples including 2-butoxyethanol, alkyl amines, and cocamide diethanolamines, toluene, and o-xylene. Due both to its quantity and quality, proper management of wastewater from UDO will be essential.

  14. Cosmetics chemical composition characterization by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Brazil is in the third position in the world's cosmetics market. It is an expanding and growing market where new products and manufacturing processes are in a constant and steady expansion. Therefore, it is mandatory that the composition of the products is well known in order to guarantee safety and quality of daily used cosmetics. The Brazilian National Health Surveillance Agency (ANVISA) has issued a resolution, RDC No. 48, March 16, 2006, which defines a 'List of Substances which can not be used in personal hygiene products, cosmetics and perfumes'. In this work, samples of locally manufactured and imported cosmetics (lipsticks, eye shadows, etc.) were analyzed using the Instrumental Neutron Activation Analysis technique. The samples were irradiated in the TRIGA IPR-R1 reactor of the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN), on a 100kW thermal power, with a thermal neutron fluence rate about 8x1011ncm-2s-1. The analysis has detected the chemical elements Br, Ba, Ga, Na, K, Sc, Fe, Cr, Zn, Sm, W, La, Rb, Cs, Ta, Ge, Co, U, Ti, V, Cl, Al, Mn and Cu. The concentrations of these elements are on a range from 5 to 3000μg.g-1. Some chemical elements observed in samples (Cl, Br, Cr, U) are included at ANVISA prohibitive list. (author)

  15. Safety- and Risk Analysis Activities in Chemical Industry in Europe

    International Nuclear Information System (INIS)

    The current paper gives an overview of the legislation and the methods used in safety and risk management in the chemical industry within Europe and in particular within the European Union. The paper is based on a report that has been written for the SOS-1 project under the Nordic nuclear safety research (NKS). Safety- and risk-related matters in the process industry, in particular, in chemical, within the EU are subject to consideration at three levels: (1) EU legislation, (2) European/intemational standardisation, and (3) socio-economic analysis. EC Directives define the 'essential requirements', e.g., protection of health and safety, that must be fulfilled when goods are placed on the market or some industry is put into operation. The European standards bodies (CEN, CENELEC and ETSI) have the task of establishing the corresponding technical specifications, meeting the essential requirements of the Directives, compliance with which will provide a presumption of conformity with the essential requirements. Such specifications are referred to as 'harmonised standards'. Compliance with harmonised standards remains voluntary, and manufacturers are free to choose any other technical solution that provides compliance with the essential requirements. This view is stated in the 'New Approach' to technical harmonisation and standardisation (details can be found on the web page: http://europe.eu.int/comm/enterprise/newapproach/standardization/index .html). Standardisation as well as the regulation of technical risks is increasingly being undertaken at European or international level. The European legislator limits its role to the affirmation of overall objectives, and leaves it to the economic players to draw up the technical procedures and standards to specify in detail the ways and means of attaining them. Many countries have introduced requirements that new legislation and/or administrative regulations be subject to socio-economic analysis. In this respect there is a

  16. Uranium complexes with macrosyclic polyethers. Synthesis and structural chemical analysis

    International Nuclear Information System (INIS)

    This dissertation reports about studies on the chemical coordination behaviour of uranium of oxidation stages IV and VI with regard to twelve different macrocyclic ligands. For the preparation of the complexes, for every system a different method has been developed. The elementary analysis of the various complexes including the uranium had been done by X-ray fluorescence analysis, and the structural characterization proceeded via vibrational, uv-vis and emission spectroscopy as well as 1H-NMR and 13C-spin-lattice relaxation time studies. Conformational analysis of the polyethers used allowed the structural changes in the complexes to be observed. The structural analysis of the hydrous uranium VI crown ether complexes yielded information of characteristic features of these types of complexes. The first coordination sphere of the uranyl ion with covalently bonded anion remains unchanged. As to the water content, there is a certain range. Depending upon the solvent used, the complexes have two or four H2O molecules per formula unit. (orig./EF)

  17. Physical and Chemical Analytical Analysis: A key component of Bioforensics

    Energy Technology Data Exchange (ETDEWEB)

    Velsko, S P

    2005-02-15

    The anthrax letters event of 2001 has raised our awareness of the potential importance of non-biological measurements on samples of biological agents used in a terrorism incident. Such measurements include a variety of mass spectral, spectroscopic, and other instrumental techniques that are part of the current armamentarium of the modern materials analysis or analytical chemistry laboratory. They can provide morphological, trace element, isotopic, and other molecular ''fingerprints'' of the agent that may be key pieces of evidence, supplementing that obtained from genetic analysis or other biological properties. The generation and interpretation of such data represents a new domain of forensic science, closely aligned with other areas of ''microbial forensics''. This paper describes some major elements of the R&D agenda that will define this sub-field in the immediate future and provide the foundations for a coherent national capability. Data from chemical and physical analysis of BW materials can be useful to an investigation of a bio-terror event in two ways. First, it can be used to compare evidence samples collected at different locations where such incidents have occurred (e.g. between the powders in the New York and Washington letters in the Amerithrax investigation) or between the attack samples and those seized during the investigation of sites where it is suspected the material was manufactured (if such samples exist). Matching of sample properties can help establish the relatedness of disparate incidents, and mis-matches might exclude certain scenarios, or signify a more complex etiology of the events under investigation. Chemical and morphological analysis for sample matching has a long history in forensics, and is likely to be acceptable in principle in court, assuming that match criteria are well defined and derived from known limits of precision of the measurement techniques in question. Thus, apart from certain

  18. ANALYSIS OF THERMAL-CHEMICAL CHARACTERISTICS OF BIOMASS ENERGY PELLETS

    Directory of Open Access Journals (Sweden)

    Zorica Gluvakov

    2014-09-01

    Full Text Available In modern life conditions, when emphasis is on environmental protection and sustainable development, fuels produced from biomass are increasingly gaining in importance, and it is necessary to consider the quality of end products obtained from biomass. Based on the existing European standards, collected literature and existing laboratory methods, this paper presents results of testing individual thermal - chemical properties of biomass energy pellets after extrusion and cooling the compressed material. Analysing samples based on standard methods, data were obtained on the basis of which individual thermal-chemical properties of pellets were estimated. Comparing the obtained results with the standards and literature sources, it can be said that moisture content, ash content and calorific values are the most important parameters for quality analysis which decide on applicability and use-value of biomass energy pellets, as biofuel. This paper also shows the impact of biofuels on the quality of environmental protection. The conclusion provides a clear statement of quality of biomass energy pellets.

  19. Instrumental neutron activation analysis. A valuable link in chemical metrology

    International Nuclear Information System (INIS)

    A systematic experimental approach to the demonstration of viability of instrumental neutron activation analysis (INAA) in chemical metrology is provided. The practical approach was derived from a complete survey of uncertainty components that affect the INAA measurement process. These uncertainty components were classified by their magnitude and origin and subsequently minimized by appropriate steps in the INAA process. The process was tested with the INAA determination of Cr in SRM 1152A stainless steel; the Cr value is certified at 17.76% with an estimated uncertainty of 0.04% (0.23% relative). The INAA results from this procedure are in agreement with these specifications. Similar procedures have been applied to INAA multi-element determinations in a high temperature alloy. Agreement with available consensus values was demonstrated in the alloy. The guidelines on the determination of uncertainty were fully met, providing through INAA a valuable independent non-destructive tool in chemical measurements of metrological value such as required in the CCQM key comparisons. (author)

  20. CHEMICALS

    CERN Multimedia

    Medical Service

    2002-01-01

    It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546

  1. Chemical analysis of ancient relicts in the Milky Way disk

    Directory of Open Access Journals (Sweden)

    Tautvaišienė G.

    2012-02-01

    Full Text Available We present detailed analysis of two groups of F- and G- type stars originally found to have similarities in their orbital parameters. The distinct kinematic properties suggest that they might originate from ancient accretion events in the Milky Way. From high resolution spectra taken with the spectrograph FIES at the Nordic Optical Telescope, La Palma, we determined abundances of oxygen, alpha- and r-process elements. Our results indicate that the sample of investigated stars is chemically homogeneous and the abundances of oxygen, alpha and r-process elements are overabundant in comparison with Galactic disk dwarfs. This provides the additional evidence that those stellar groups had the common formation and possible origin from disrupted satellites.

  2. Microarray Technology for Major Chemical Contaminants Analysis in Food: Current Status and Prospects

    Directory of Open Access Journals (Sweden)

    Xiaoxia Ding

    2012-07-01

    Full Text Available Chemical contaminants in food have caused serious health issues in both humans and animals. Microarray technology is an advanced technique suitable for the analysis of chemical contaminates. In particular, immuno-microarray approach is one of the most promising methods for chemical contaminants analysis. The use of microarrays for the analysis of chemical contaminants is the subject of this review. Fabrication strategies and detection methods for chemical contaminants are discussed in detail. Application to the analysis of mycotoxins, biotoxins, pesticide residues, and pharmaceutical residues is also described. Finally, future challenges and opportunities are discussed.

  3. Analysis Of Samples From Tank 6F Chemical Cleaning

    International Nuclear Information System (INIS)

    Savannah River Remediation (SRR) is preparing Tank 6F for closure. The first step in preparing the tank for closure is mechanical sludge removal. In mechanical sludge removal, personnel add liquid (e.g., inhibited water or supernate salt solution) to the tank to form a slurry. They mix the liquid and sludge with pumps, and transfer the slurry to another tank for further processing. Mechanical sludge removal effectively removes the bulk of the sludge from a tank, but is not able to remove all of the sludge. In Tank 6F, SRR estimated a sludge heel of 5,984 gallons remained after mechanical sludge removal. To remove this sludge heel, SRR performed chemical cleaning. The chemical cleaning included two oxalic acid strikes, a spray wash, and a water wash. SRR conducted the first oxalic acid strike as follows. Personnel added 110,830 gallons of 8 wt % oxalic acid to Tank 6F and mixed the contents of Tank 6F with two submersible mixer pumps (SMPs) for approximately four days. Following the mixing, they transferred 115,903 gallons of Tank 6F material to Tank 7F. The SMPs were operating when the transfer started and were shut down approximately five hours after the transfer started. SRR collected a sample of the liquid from Tank 6F and submitted it to SRNL for analysis. Mapping of the tank following the transfer indicated that 2,400 gallons of solids remained in the tank. SRR conducted the second oxalic acid strike as follows. Personnel added 28,881 gallons of 8 wt % oxalic acid to Tank 6F. Following the acid addition, they visually inspected the tank and transferred 32,247 gallons of Tank 6F material to Tank 7F. SRR collected a sample of the liquid from Tank 6F and submitted it to SRNL for analysis. Mapping of the tank following the transfer indicated that 3,248 gallons of solids remained in the tank. Following the oxalic acid strikes, SRR performed Spray Washing with oxalic acid to remove waste collected on internal structures, cooling coils, tank top internals, and tank

  4. Chemical hazards analysis of resilient flooring for healthcare.

    Science.gov (United States)

    Lent, Tom; Silas, Julie; Vallette, Jim

    2010-01-01

    This article addresses resilient flooring, evaluating the potential health effects of vinyl flooring and the leading alternatives-synthetic rubber, polyolefin, and linoleum-currently used in the healthcare marketplace. The study inventories chemicals incorporated as components of each of the four material types or involved in their life cycle as feedstocks, intermediary chemicals, or emissions. It then characterizes those chemicals using a chemical hazard-based framework that addresses persistence and bioaccumulation, human toxicity, and human exposures. PMID:21165873

  5. Chemical analysis and potential health risks of hookah charcoal.

    Science.gov (United States)

    Elsayed, Yehya; Dalibalta, Sarah; Abu-Farha, Nedal

    2016-11-01

    Hookah (waterpipe) smoking is a very common practice that has spread globally. There is growing evidence on the hazardous consequences of smoking hookah, with studies indicating that its harmful effects are comparable to cigarette smoking if not worse. Charcoal is commonly used as a heating source for hookah smoke. Although charcoal briquettes are thought to be one of the major contributors to toxicity, their composition and impact on the smoke generated remains largely unidentified. This study aims to analyze the elemental composition of five different raw synthetic and natural charcoals by using Carbon-Hydrogen-Nitrogen (CHN) analysis, inductively coupled plasma (ICP), and scanning electron microscopy coupled with energy dispersive X-Ray spectrometry (SEM-EDS). Elemental analysis showed that the raw charcoals contain heavy metals such as zinc, iron, cadmium, vanadium, aluminum, lead, chromium, manganese and cobalt at concentrations similar, if not higher than, cigarettes. In addition, thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) was used to analyze the chemical composition of the smoke produced from burning the charcoal samples. The smoke emitted from charcoal was found to be the source of numerous compounds which could be hazardous to health. A total of seven carcinogens, 39 central nervous system depressants and 31 respiratory irritants were identified. PMID:27343945

  6. Chemical analysis of Argonne premium coal samples. Bulletin

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, C.A.

    1997-11-01

    Contents: The Chemical Analysis of Argonne Premium Coal Samples: An Introduction; Rehydration of Desiccated Argonne Premium Coal Samples; Determination of 62 Elements in 8 Argonne Premium Coal Ash Samples by Automated Semiquantitative Direct-Current Arc Atomic Emission Spectrography; Determination of 18 Elements in 5 Whole Argonne Premium Coal Samples by Quantitative Direct-Current Arc Atomic Emission Spectrography; Determination of Major and Trace Elements in Eight Argonne Premium Coal Samples (Ash and Whole Coal) by X-Ray Fluorescence Spectrometry; Determination of 29 Elements in 8 Argonne Premium Coal Samples by Instrumental Neutron Activation Analysis; Determination of Selected Elements in Coal Ash from Eight Argonne Premium Coal Samples by Atomic Absorption Spectrometry and Atomic Emission Spectrometry; Determination of 25 Elements in Coal Ash from 8 Argonne Premium Coal Samples by Inductively Coupled Argon Plasma-Atomic Emission Spectrometry; Determination of 33 Elements in Coal Ash from 8 Argonne Premium Coal Samples by Inductively Coupled Argon Plasma-Mass Spectrometry; Determination of Mercury and Selenium in Eight Argonne Premium Coal Samples by Cold-Vapor and Hydride-Generation Atomic Absorption Spectrometry; Determinaton of Carbon, Hydrogen, and Nitrogen in Eight Argonne Premium Coal Samples by Using a Gas Chromatographic Analyzer with a Thermal Conductivity Detector; and Compilation of Multitechnique Determinations of 51 Elements in 8 Argonne Premium Coal Samples.

  7. Safety- and Risk Analysis Activities in Chemical Industry in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Kozine, Igor; Duijm, Nijs Jan; Lauridsen Kurt [Risoe National Laboratory, Roskilde (Denmark). Systems Analysis Department

    2001-07-01

    The current paper gives an overview of the legislation and the methods used in safety and risk management in the chemical industry within Europe and in particular within the European Union. The paper is based on a report that has been written for the SOS-1 project under the Nordic nuclear safety research (NKS). Safety- and risk-related matters in the process industry, in particular, in chemical, within the EU are subject to consideration at three levels: (1) EU legislation, (2) European/intemational standardisation, and (3) socio-economic analysis. EC Directives define the 'essential requirements', e.g., protection of health and safety, that must be fulfilled when goods are placed on the market or some industry is put into operation. The European standards bodies (CEN, CENELEC and ETSI) have the task of establishing the corresponding technical specifications, meeting the essential requirements of the Directives, compliance with which will provide a presumption of conformity with the essential requirements. Such specifications are referred to as 'harmonised standards'. Compliance with harmonised standards remains voluntary, and manufacturers are free to choose any other technical solution that provides compliance with the essential requirements. This view is stated in the 'New Approach' to technical harmonisation and standardisation (details can be found on the web page: http://europe.eu.int/comm/enterprise/newapproach/standardization/index .html). Standardisation as well as the regulation of technical risks is increasingly being undertaken at European or international level. The European legislator limits its role to the affirmation of overall objectives, and leaves it to the economic players to draw up the technical procedures and standards to specify in detail the ways and means of attaining them. Many countries have introduced requirements that new legislation and/or administrative regulations be subject to socio-economic analysis

  8. ACTINIDE REMOVAL PROCESS SAMPLE ANALYSIS, CHEMICAL MODELING, AND FILTRATION EVALUATION

    Energy Technology Data Exchange (ETDEWEB)

    Martino, C.; Herman, D.; Pike, J.; Peters, T.

    2014-06-05

    Filtration within the Actinide Removal Process (ARP) currently limits the throughput in interim salt processing at the Savannah River Site. In this process, batches of salt solution with Monosodium Titanate (MST) sorbent are concentrated by crossflow filtration. The filtrate is subsequently processed to remove cesium in the Modular Caustic Side Solvent Extraction Unit (MCU) followed by disposal in saltstone grout. The concentrated MST slurry is washed and sent to the Defense Waste Processing Facility (DWPF) for vitrification. During recent ARP processing, there has been a degradation of filter performance manifested as the inability to maintain high filtrate flux throughout a multi-batch cycle. The objectives of this effort were to characterize the feed streams, to determine if solids (in addition to MST) are precipitating and causing the degraded performance of the filters, and to assess the particle size and rheological data to address potential filtration impacts. Equilibrium modelling with OLI Analyzer{sup TM} and OLI ESP{sup TM} was performed to determine chemical components at risk of precipitation and to simulate the ARP process. The performance of ARP filtration was evaluated to review potential causes of the observed filter behavior. Task activities for this study included extensive physical and chemical analysis of samples from the Late Wash Pump Tank (LWPT) and the Late Wash Hold Tank (LWHT) within ARP as well as samples of the tank farm feed from Tank 49H. The samples from the LWPT and LWHT were obtained from several stages of processing of Salt Batch 6D, Cycle 6, Batch 16.

  9. Avogadro: an advanced semantic chemical editor, visualization, and analysis platform

    Directory of Open Access Journals (Sweden)

    Hanwell Marcus D

    2012-08-01

    Full Text Available Abstract Background The Avogadro project has developed an advanced molecule editor and visualizer designed for cross-platform use in computational chemistry, molecular modeling, bioinformatics, materials science, and related areas. It offers flexible, high quality rendering, and a powerful plugin architecture. Typical uses include building molecular structures, formatting input files, and analyzing output of a wide variety of computational chemistry packages. By using the CML file format as its native document type, Avogadro seeks to enhance the semantic accessibility of chemical data types. Results The work presented here details the Avogadro library, which is a framework providing a code library and application programming interface (API with three-dimensional visualization capabilities; and has direct applications to research and education in the fields of chemistry, physics, materials science, and biology. The Avogadro application provides a rich graphical interface using dynamically loaded plugins through the library itself. The application and library can each be extended by implementing a plugin module in C++ or Python to explore different visualization techniques, build/manipulate molecular structures, and interact with other programs. We describe some example extensions, one which uses a genetic algorithm to find stable crystal structures, and one which interfaces with the PackMol program to create packed, solvated structures for molecular dynamics simulations. The 1.0 release series of Avogadro is the main focus of the results discussed here. Conclusions Avogadro offers a semantic chemical builder and platform for visualization and analysis. For users, it offers an easy-to-use builder, integrated support for downloading from common databases such as PubChem and the Protein Data Bank, extracting chemical data from a wide variety of formats, including computational chemistry output, and native, semantic support for the CML file format

  10. Meta-Analysis of the Chemical and Non-Chemical Stressors Affecting Childhood Obesity

    Science.gov (United States)

    Worldwide, approximately 42 million children under the age of 5 years are considered overweight or obese. While much research has focused on individual behaviors impacting obesity, little research has emphasized the complex interactions of numerous chemical and non-chemical stres...

  11. EDXRF quantitative analysis of chromophore chemical elements in corundum samples.

    Science.gov (United States)

    Bonizzoni, L; Galli, A; Spinolo, G; Palanza, V

    2009-12-01

    Corundum is a crystalline form of aluminum oxide (Al(2)O(3)) and is one of the rock-forming minerals. When aluminum oxide is pure, the mineral is colorless, but the presence of trace amounts of other elements such as iron, titanium, and chromium in the crystal lattice gives the typical colors (including blue, red, violet, pink, green, yellow, orange, gray, white, colorless, and black) of gemstone varieties. The starting point for our work is the quantitative evaluation of the concentration of chromophore chemical elements with a precision as good as possible to match the data obtained by different techniques as such as optical absorption photoluminescence. The aim is to give an interpretation of the absorption bands present in the NIR and visible ranges which do not involve intervalence charge transfer transitions (Fe(2+) --> Fe(3+) and Fe(2+) --> Ti(4+)), commonly considered responsible of the important features of the blue sapphire absorption spectra. So, we developed a method to evaluate as accurately as possible the autoabsorption effects and the secondary excitation effects which frequently are sources of relevant errors in the quantitative EDXRF analysis. PMID:19821113

  12. Method of chemical analysis of silicate rocks (1962)

    International Nuclear Information System (INIS)

    A rapid method of analysis for the physical and chemical determination of the major constituents of silicate rocks is described. Water losses at 100 deg. C and losses of volatile elements at 1000 deg. C are estimated after staying in oven for these temperatures, or by mean of a thermo-balance. The determination of silica is made by a double insolubilization with hydrochloric acid on attack solution with sodium carbonate; total iron and aluminium, both with calcium and magnesium, after ammoniacal precipitation of Fe and Al, are determined on the filtration product of silica by titrimetry-photometry of their complexes with EDTA. The alkalis Na and K by flame spectrophotometry, Mn by colorimetry of the permanganate, and Ti by mean of his complex with H2O2, are determined on fluosulfuric attack solution. Phosphorus is determined by his complex with 'molybdenum blue' on a fluoro-nitro-boric attack solution; iron is estimated by potentiometry, with the help of bichromate on hydrofluoric solution. (author)

  13. A spectroscopic analysis of the chemically peculiar star HD207561

    CERN Document Server

    Joshi, S; Martinez, P; Sachkov, M; Joshi, Y C; Seetha, S; Chakradhari, N K; Mary, D L; Girish, V; Ashoka, B N

    2012-01-01

    In this paper we present a high-resolution spectroscopic analysis of the chemically peculiar star HD207561. During a survey programme to search for new roAp stars in the Northern hemisphere, Joshi et al. (2006) observed significant photometric variability on two consecutive nights in the year 2000. The amplitude spectra of the light curves obtained on these two nights showed oscillations with a frequency of 2.79 mHz [P~6-min]. However, subsequent follow-up observations could not confirm any rapid variability. In order to determine the spectroscopic nature of HD207561, high-resolution spectroscopic and spectro-polarimetric observations were carried out. A reasonable fit of the calculated Hbeta line profile to the observed one yields the effective temperature (Teff) and surface gravity (log g) as 7300 K and 3.7 dex, respectively. The derived projected rotational velocity (vsin i) for HD207561 is 74 km/sec indicative of a relatively fast rotator. The position of HD207561 in the H-R diagram implies that this is s...

  14. Microplasmas for chemical analysis: analytical tools or research toys?

    International Nuclear Information System (INIS)

    An overview of the activities of the research groups that have been involved in fabrication, development and characterization of microplasmas for chemical analysis over the last few years is presented. Microplasmas covered include: miniature inductively coupled plasmas (ICPs); capacitively coupled plasmas (CCPs); microwave-induced plasmas (MIPs); a dielectric barrier discharge (DBD); microhollow cathode discharge (MCHD) or microstructure electrode (MSE) discharges, other microglow discharges (such as those formed between 'liquid' electrodes); microplasmas formed in micrometer-diameter capillary tubes for gas chromatography (GC) or high-performance liquid chromatography (HPLC) applications, and a stabilized capacitive plasma (SCP) for GC applications. Sample introduction into microplasmas, in particular, into a microplasma device (MPD), battery operation of a MPD and of a mini- in-torch vaporization (ITV) microsample introduction system for MPDs, and questions of microplasma portability for use on site (e.g., in the field) are also briefly addressed using examples of current research. To emphasize the significance of sample introduction into microplasmas, some previously unpublished results from the author's laboratory have also been included. And an overall assessment of the state-of-the-art of analytical microplasma research is provided

  15. Similarity Analysis of Cable Insulations by Chemical Test

    International Nuclear Information System (INIS)

    As result of this experiment, it was found that FT-IR test for material composition, TGA test for aging trend are applicable for similarity analysis of cable materials. OIT is recommended as option if TGA doesn't show good trend. Qualification of new insulation by EQ report of old insulation should be based on higher activation energy of new insulation than that of old one in the consideration of conservatism. In old nuclear power plant, it is easy to find black cable which has no marking of cable information such as manufacturer, material name and voltage. If a type test is required for qualification of these cables, how could I select representative cable? How could I determine the similarity of these cables? If manufacturer has qualified a cable for nuclear power plant more than a decade ago and composition of cable material is changed with similar one, is it acceptable to use the old EQ report for recently manufactured cable? It is well known to use FT-IR method to determine the similarity of cable materials. Infrared ray is easy tool to compare compositions of each material. But, it is not proper to compare aging trend of these materials. Study for similarity analysis of cable insulation by chemical test is described herein. To study a similarity evaluation method for polymer materials, FT-IR, TGA and OIT tests were performed for two cable insulation(old and new) which were supplied from same manufacturer. FT-IR shows good result to compare material compositions while TGA and OIT show good result to compare aging character of materials

  16. Similarity Analysis of Cable Insulations by Chemical Test

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Seog [Central Research Institute of Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

    2013-10-15

    As result of this experiment, it was found that FT-IR test for material composition, TGA test for aging trend are applicable for similarity analysis of cable materials. OIT is recommended as option if TGA doesn't show good trend. Qualification of new insulation by EQ report of old insulation should be based on higher activation energy of new insulation than that of old one in the consideration of conservatism. In old nuclear power plant, it is easy to find black cable which has no marking of cable information such as manufacturer, material name and voltage. If a type test is required for qualification of these cables, how could I select representative cable? How could I determine the similarity of these cables? If manufacturer has qualified a cable for nuclear power plant more than a decade ago and composition of cable material is changed with similar one, is it acceptable to use the old EQ report for recently manufactured cable? It is well known to use FT-IR method to determine the similarity of cable materials. Infrared ray is easy tool to compare compositions of each material. But, it is not proper to compare aging trend of these materials. Study for similarity analysis of cable insulation by chemical test is described herein. To study a similarity evaluation method for polymer materials, FT-IR, TGA and OIT tests were performed for two cable insulation(old and new) which were supplied from same manufacturer. FT-IR shows good result to compare material compositions while TGA and OIT show good result to compare aging character of materials.

  17. Analysis of chemical bonding by means of reduced density matrices

    OpenAIRE

    Álvarez Boto, Roberto

    2013-01-01

    The modern Theory of Chemical Bonding may be well understood as the study of reduced density matrices (RDMs) in real space regions to get new insights of the chemical bond. Although, much work has been widely used to understand chemical bonding from one-electron density, include correlation effects requires the access to higher order densities. Based on the cumulant expansion of the RDMs, a set of bonding indices which may decomposed into one-electron component may be defined. Each comp...

  18. TECHNO-ECONOMIC ANALYSIS OF MODERNIZATION FOR CHEMICAL EQUIPMENT

    OpenAIRE

    Задольський, Аркадій Михайлович

    2015-01-01

    Industry of Ukraine is currently in a very difficult situation. This fully relates to the chemical industry. The real way to overcome negative developments, in the chemical industry, is improving its material base and objects of fixed assets. First of all, need improvement, machinery and equipment (chemical equipment). This important problem can be solved by upgrading existing equipment. In order to choose the most efficient option for replacement of obsolete equipment, should apply the techn...

  19. Sanitary chemical and bacteriological analysis of drinking water in Kocani

    OpenAIRE

    Panova, Gordana; Panova, Blagica; Panov, Nenad

    2013-01-01

    Acute diseases occur as a result of contamination of drinking water with microorganisms (causes gastrointestinal disease) or contamination with nitrates causes methemoglobinemia in children), pesticides or other chemicals. The occurrence of water-borne infections due to inadequate sanitation, disposal of manure decomposition processing operating system or contamination during distribution. Harmful chemical pollution due to accidents or inadequate distribution system ...

  20. Nonradiological chemical pathway analysis and identification of chemicals of concern for environmental monitoring at the Hanford Site

    International Nuclear Information System (INIS)

    Pacific Northwest's Surface Environmental Surveillance Project (SESP) is an ongoing effort tot design, review, and conducted monitoring on and off the Hanford site. Chemicals of concern that were selected are listed. Using modeled exposure pathways, the offsite cancer incidence and hazard quotient were calculated and a retrospective pathway analysis performed to estimate what onsite concentrations would be required in the soil for each chemical of concern and other detected chemicals that would be required to obtain an estimated offsite human-health risk of 1.0E-06 cancer incidence or 1.0 hazard quotient. This analysis indicates that current nonradiological chemical contamination occurring on the site does not pose a significant offsite human-health risk; the highest cancer incidence to the offsite maximally exposed individual was from arsenic (1.76E-10); the highest hazard quotient was chromium(VI) (1.48E-04). The most sensitive pathways of exposure were surfacewater and aquatic food consumption. Combined total offsite excess cancer incidence was 2.09E-10 and estimated hazard quotient was 2.40E-04. Of the 17 identified chemicals of concern, the SESP does not currently (routinely) monitor arsenic, benzo(a)pyrene, bis(2- ethylhexyl)phthalate (BEHP), and chrysene. Only 3 of the chemicals of concern (arsenic, BEHP, chloroform) could actually occur in onsite soil at concern high enough to cause a 1.0E-06 excess cancer incidence or a 1.0 hazard index for a given offsite exposure pathway. During the retrospective analysis, 20 other chemicals were also evaluated; only vinyl chloride and thallium could reach targeted offsite risk values

  1. Meta-Analysis of the Chemical and Non-Chemical Stressors Affecting Childhood Obesity?

    Science.gov (United States)

    Background: Worldwide, approximately 42 million children under the age of 5 years are considered overweight or obese. While much research has focused on individual behaviors impacting obesity, little research has emphasized the complex interactions of numerous chemical and non-ch...

  2. SOIL QUALITY ASSESSMENT BASED ON CHEMICAL, ENZYMATIC AND BACTERIOLOGICAL ANALYSIS

    Directory of Open Access Journals (Sweden)

    Sofia-Paulina BALAURE

    2012-01-01

    Full Text Available This study highlights the problem of soil pollution as the result of human activities. Soil pollutans may be either chemicals or biological in nature. microbial enzymatic activities are often proposed as indicators of environmental stress. The soil samples were submitted by chemical, microbiological and enzymatic analyses. Chemical analyses were been made for determinating the heavy metals. Heavy metals from the forest soil were represented by Cu, Zn, Mn, Ni, Pb, Cd and Cr. To evaluate the concentration in heavy metals from the filtrate, we used a acetylene-nitrous oxide flame atomic absorption spectrophotometry. Potential dehydrogenase activity, the only indicator of the possible sources of pollution, excluded the presence of either chemical or biological pollution. The number of bacteria involved in the biogeochemical cycle of nitrogen in the analyzed soil indicated a high efficiency regarding the mineralization of the organic residues of plant and animal origin.

  3. Disclosure of hydraulic fracturing fluid chemical additives: analysis of regulations.

    Science.gov (United States)

    Maule, Alexis L; Makey, Colleen M; Benson, Eugene B; Burrows, Isaac J; Scammell, Madeleine K

    2013-01-01

    Hydraulic fracturing is used to extract natural gas from shale formations. The process involves injecting into the ground fracturing fluids that contain thousands of gallons of chemical additives. Companies are not mandated by federal regulations to disclose the identities or quantities of chemicals used during hydraulic fracturing operations on private or public lands. States have begun to regulate hydraulic fracturing fluids by mandating chemical disclosure. These laws have shortcomings including nondisclosure of proprietary or "trade secret" mixtures, insufficient penalties for reporting inaccurate or incomplete information, and timelines that allow for after-the-fact reporting. These limitations leave lawmakers, regulators, public safety officers, and the public uninformed and ill-prepared to anticipate and respond to possible environmental and human health hazards associated with hydraulic fracturing fluids. We explore hydraulic fracturing exemptions from federal regulations, as well as current and future efforts to mandate chemical disclosure at the federal and state level. PMID:23552653

  4. Chemical Analysis of Wastewater from Unconventional Drilling Operations

    OpenAIRE

    Jonathan B. Thacker; Doug D. Carlton; Zacariah L. Hildenbrand; Kadjo, Akinde F.; Schug, Kevin A.

    2015-01-01

    Trillions of liters of wastewater from oil and gas extraction are generated annually in the US. The contribution from unconventional drilling operations (UDO), such as hydraulic fracturing, to this volume will likely continue to increase in the foreseeable future. The chemical content of wastewater from UDO varies with region, operator, and elapsed time after production begins. Detailed chemical analyses may be used to determine its content, select appropriate treatment options, and identify ...

  5. Quasi-Chemical and Structural Analysis of Polarizable Anion Hydration

    OpenAIRE

    Rogers, David M.; Beck, Thomas L.

    2009-01-01

    Quasi-chemical theory is utilized to analyze the roles of solute polarization and size in determining the structure and thermodynamics of bulk anion hydration for the Hofmeister series Cl$^-$, Br$^-$, and I$^-$. Excellent agreement with experiment is obtained for whole salt hydration free energies using the polarizable AMOEBA force field. The quasi-chemical approach exactly partitions the solvation free energy into inner-shell, outer-shell packing, and outer-shell long-ranged contributions by...

  6. 40 CFR 761.292 - Chemical extraction and analysis of individual samples and composite samples.

    Science.gov (United States)

    2010-07-01

    ....61(a)(6) § 761.292 Chemical extraction and analysis of individual samples and composite samples. Use... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Chemical extraction and analysis of individual samples and composite samples. 761.292 Section 761.292 Protection of Environment...

  7. CERENA: ChEmical REaction Network Analyzer—A Toolbox for the Simulation and Analysis of Stochastic Chemical Kinetics

    Science.gov (United States)

    Kazeroonian, Atefeh; Fröhlich, Fabian; Raue, Andreas; Theis, Fabian J.; Hasenauer, Jan

    2016-01-01

    Gene expression, signal transduction and many other cellular processes are subject to stochastic fluctuations. The analysis of these stochastic chemical kinetics is important for understanding cell-to-cell variability and its functional implications, but it is also challenging. A multitude of exact and approximate descriptions of stochastic chemical kinetics have been developed, however, tools to automatically generate the descriptions and compare their accuracy and computational efficiency are missing. In this manuscript we introduced CERENA, a toolbox for the analysis of stochastic chemical kinetics using Approximations of the Chemical Master Equation solution statistics. CERENA implements stochastic simulation algorithms and the finite state projection for microscopic descriptions of processes, the system size expansion and moment equations for meso- and macroscopic descriptions, as well as the novel conditional moment equations for a hybrid description. This unique collection of descriptions in a single toolbox facilitates the selection of appropriate modeling approaches. Unlike other software packages, the implementation of CERENA is completely general and allows, e.g., for time-dependent propensities and non-mass action kinetics. By providing SBML import, symbolic model generation and simulation using MEX-files, CERENA is user-friendly and computationally efficient. The availability of forward and adjoint sensitivity analyses allows for further studies such as parameter estimation and uncertainty analysis. The MATLAB code implementing CERENA is freely available from http://cerenadevelopers.github.io/CERENA/. PMID:26807911

  8. Evaluating Chemical Persistence in a Multimedia Environment: ACART Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, D.H.; McKone, T.E.; Kastenberg, W.E.

    1999-02-01

    For the thousands of chemicals continuously released into the environment, it is desirable to make prospective assessments of those likely to be persistent. Persistent chemicals are difficult to remove if adverse health or ecological effects are later discovered. A tiered approach using a classification scheme and a multimedia model for determining persistence is presented. Using specific criteria for persistence, a classification tree is developed to classify a chemical as ''persistent'' or ''non-persistent'' based on the chemical properties. In this approach, the classification is derived from the results of a standardized unit world multimedia model. Thus, the classifications are more robust for multimedia pollutants than classifications using a single medium half-life. The method can be readily implemented and provides insight without requiring extensive and often unavailable data. This method can be used to classify chemicals when only a few properties are known and be used to direct further data collection. Case studies are presented to demonstrate the advantages of the approach.

  9. International Research Project on the Effects of Chemical Ageing of Polymers on Performance Properties: Chemical and Thermal Analysis

    Science.gov (United States)

    Bulluck, J. W.; Rushing, R. A.

    1996-01-01

    Work during the past six months has included significant research in several areas aimed at further clarification of the aging and chemical failure mechanism of thermoplastics (PVDF or Tefzel) pipes. Among the areas investigated were the crystallinity changes associated with both the Coflon and Tefzel after various simulated environmental exposures using X-ray diffraction analysis. We have found that significant changes in polymer crystallinity levels occur as a function of the exposures. These crystallinity changes may have important consequences on the fracture, fatigue, tensile, and chemical resistance of the materials. We have also noted small changes in the molecular weight distribution. Again these changes may result in variations in the mechanical and chemical properties in the material. We conducted numerous analytical studies with methods including X-ray Diffraction, Gel Permeation Chromatography, Fourier Transform Infrared Spectroscopy, Ultra- Violet Scanning Analysis, GC/Mass Spectrometry, Differential Scanning Calorimetry and Thermomechanical Analysis. In the ultra-violet analysis we noted the presence of an absorption band indicative of triene formation. We investigated a number of aged samples of both Tefzel and Coflon that were forwarded from MERL. We also cast films at SWT and subjected these films to a refluxing methanol 1% ethylene diamine solution. An updated literature search was conducted using Dialog and DROLLS to identify any new papers that may have been published in the open literature since the start of this project. The updated literature search and abstracts are contained in the Appendix section of this report.

  10. ANALYSIS OF SOLUBLE CHEMICAL TRANSFER BY RUNOFF WATER IN FIELD

    Institute of Scientific and Technical Information of China (English)

    TONG Ju-xiu; YANG Jin-zhong

    2008-01-01

    In order to determine the main factors influencing soluble chemical transfer and corresponding techniques for reducing fertilizer loss caused by runoff in irrigated fields, a physically based two-layer model was developed with incomplete mixing theory. Different forms of incomplete mixing parameters were introduced in the model, which was successfully verified with previous published experimental data. According to comparison, the chemicals loss of fertilizer is very sensitive to the runoff-related parameter while it is not sensitive to the infiltration-related parameter. The calculated results show that the chemicals in infiltration water play an important role in the early time of rainfall even with saturated soil, and it is mainly in the runoff flow in the late rainfall. Therefore, prevention of shallow subsurface drainage in the early rainfall is an effective way to reduce fertilizer loss, and the coverage on soil surface is another effective way.

  11. Analysis of forward and inverse problems in chemical dynamics and spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Rabitz, H. [Princeton Univ., NJ (United States)

    1993-12-01

    The overall scope of this research concerns the development and application of forward and inverse analysis tools for problems in chemical dynamics and chemical kinetics. The chemical dynamics work is specifically associated with relating features in potential surfaces and resultant dynamical behavior. The analogous inverse research aims to provide stable algorithms for extracting potential surfaces from laboratory data. In the case of chemical kinetics, the focus is on the development of systematic means to reduce the complexity of chemical kinetic models. Recent progress in these directions is summarized below.

  12. Powerful chemical technique. [CSIR uses new x-ray diffractometer for structural chemical analysis

    Energy Technology Data Exchange (ETDEWEB)

    The CSIR's National Chemical Research Laboratory (NCRL) is now using one of the most powerful techniques available to determine the structure of molecules. It has recently acquired a Single Crystal X-ray Diffractometer. This powerful method provides the only means of determining the structure of certain compounds. NCRL scientists often carry out structure determinations to find out the relative or absolute stereochemistry of molecules. This is important when correlating physiological activity and structure, information which is necessary for synthesizing medicines with specific characteristics.

  13. Probabilistic thermo-chemical analysis of a pultruded composite rod

    DEFF Research Database (Denmark)

    Baran, Ismet; Tutum, Cem Celal; Hattel, Jesper Henri

    2012-01-01

    In the present study the deterministic thermo-chemical pultrusion simulation of a composite rod taken from the literature [7] is used as a validation case. The predicted centerline temperature and cure degree profiles of the rod match well with those in the literature [7]. Following the validation...

  14. Analysis of chemical coal cleaning processes. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    Six chemical coal cleaning processes were examined. Conceptual designs and costs were prepared for these processes and coal preparation facilities, including physical cleaning and size reduction. Transportation of fine coal in agglomerated and unagglomerated forms was also discussed. Chemical cleaning processes were: Pittsburgh Energy Technology Center, Ledgemont, Ames Laboratory, Jet Propulsion Laboratory (two versions), and Guth Process (KVB). Three of the chemical cleaning processes are similar in concept: PETC, Ledgemont, and Ames. Each of these is based on the reaction of sulfur with pressurized oxygen, with the controlling factor being the partial pressure of oxygen in the reactor. All of the processes appear technically feasible. Economic feasibility is less certain. The recovery of process chemicals is vital to the JPL and Guth processes. All of the processes consume significant amounts of energy in the form of electric power and coal. Energy recovery and increased efficiency are potential areas for study in future more detailed designs. The Guth process (formally designed KVB) appears to be the simplest of the systems evaluated. All of the processes require future engineering to better determine methods for scaling laboratory designs/results to commercial-scale operations. A major area for future engineering is to resolve problems related to handling, feeding, and flow control of the fine and often hot coal.

  15. Portfolio Assessment on Chemical Reactor Analysis and Process Design Courses

    Science.gov (United States)

    Alha, Katariina

    2004-01-01

    Assessment determines what students regard as important: if a teacher wants to change students' learning, he/she should change the methods of assessment. This article describes the use of portfolio assessment on five courses dealing with chemical reactor and process design during the years 1999-2001. Although the use of portfolio was a new…

  16. Multivariate Statistical Analysis of Phyllite Samples Based on Chemical (XRF) and Mineralogical Data by XRD

    OpenAIRE

    2012-01-01

    It is presented the results obtained of a multivariate statistical analysis concerning the chemical and phase composition, as a characterization purpose, carried out with 52 rock phyllite samples selected from the provinces of Almería and Granada (SE Spain). Chemical analysis was performed by X-ray fluorescence (XRF). Crystalline phase analysis was performed by X-ray powder diffraction (XRD) and the mineralogical composition was then deduced. Quantification of weight loss (100° an...

  17. Mass spectrometry analysis of polychlorinated biphenyls: chemical ionization and selected ion chemical ionization using methane as a reagent gas

    OpenAIRE

    RAYMOND E. MARCH; MILA D. LAUSEVIC; TATJANA M. VASILJEVIC

    2000-01-01

    In the present paper a quadrupole ion trap mass spectrometer, coupled with a gas chromatograph, was used to compare the electron impact ionization (EI) and chemical ionization (Cl) technique, in terms of their selectivity in polychlorinated biphenyls (PCBs) quantitative analysis. The experiments were carried out with a modified Varian SATURN III quadrupole ion-storage mass spectrometer equipped with Varian waveform generator, coupled with a gas chromatograph with DB-5 capillary column. The di...

  18. CHEMICAL ANALYSIS OF DENSE-GAS EXTRACTS FROM LIME FLOWERS

    Directory of Open Access Journals (Sweden)

    Demyanenko DV

    2015-04-01

    Full Text Available The purpose of this work was to make qualitative and quantitative analysis of phenolic biologically active substances (BAS in the extracts produced from lime flowers with condensed gases, using method of high-performance liquid chromatography (HPLC. Materials and methods: materials for this study were the extracts obtained by consequent processing of the herbal drug and marcs thereof with various condensed gases: difluorochloromethane (Freon R22, difluoromethane (Freon R32, azeotropic mixture of difluoromethane with pentafluoroethane (Freon 410A and freon-ammonium mixture. Extracts obtained with the latter were subjected to further fractionation by liquidliquid separation into hexane, chloroform, ethyl acetate and aqueous-alcohol phases. Besides, the supercritical СО2 extract, obtained from the herbal drug under rather strong conditions (at temperature 60°С and pressure 400 bar, was studied in our previous research. Presence of phenolic BAS and their quantity in the researched samples were determined by method of HPLC with UVspectrometric detection. Results and discussion: It has been found that Freon R22 extracted trace amounts of rutin from lime flowers – its content was only 0.08% of the total extract weight. On the other hand, Freons R32 and R410А showed good selectivity to moderately polar BAS of lime flowers (derivatives of flavonoids and hydroxycinnamic acids: in particular, the extract obtained with freon R32 contained about 1.3% of the total phenolic substances, and it was the only one of the investigated condensed gases used by us which took the basic flavonoid of lime flowers tiliroside – its content was 0.42% of extract weight. Also Freons R32 and R410А were able to withdraw another compound dominating among phenolic substances in the yielded extracts. Its quantity was rather noticeable – up to 0.87% of extract weight. This substance was not identified by existing database, but its UV-spectrum was similar to those of

  19. Modeling and analysis of uranium isotope enrichment by chemical exchange

    International Nuclear Information System (INIS)

    A theoretical study of uranium isotopes separation by chemical exchange, starting with an accurate mathematical model, is presented. The experimental data used in this study were obtained by reverse break-through operation and the numerical algorithm, developed for simulation in a previous study, was adapted to be suitable for this kind of processes. The model parameters were identified from experimental data and simulations were carried out for different experimental conditions. (author)

  20. Chemical non-equilibrium flow analysis of H2 fueled scramjet nozzle

    OpenAIRE

    Yue Huang; Peiyong Wang; Yang Dou; Fei Xing

    2015-01-01

    A numerical analysis of the chemical non-equilibrium phenomena in a scramjet nozzle has been performed using CHEMKIN software. Different operating conditions of the Hyshot scramjet nozzle were simulated and analyzed. Three chemical status, frozen flow, equilibrium flow, and non-equilibrium flow, were tested and compared to demonstrate the chemical reaction effect on nozzle flow field. The real non-equilibrium flow simulation result is between those of the two limiting cases: frozen flow and e...

  1. The Matthew Effect in Environmental Science Publication: A Bibliometric Analysis of Chemical Substances in Journal Articles

    OpenAIRE

    Grandjean Philippe; Eriksen Mette L; Ellegaard Ole; Wallin Johan A

    2011-01-01

    Abstract Background While environmental research addresses scientific questions of possible societal relevance, it is unclear to what degree research focuses on environmental chemicals in need of documentation for risk assessment purposes. Methods In a bibliometric analysis, we used SciFinder to extract Chemical Abstract Service (CAS) numbers for chemicals addressed by publications in the 78 major environmental science journals during 2000-2009. The Web of Science was used to conduct title se...

  2. Chemical Analysis of Emu Feather Fiber Reinforced Epoxy Composites

    Directory of Open Access Journals (Sweden)

    V.Chandra sekhar

    2015-07-01

    Full Text Available A composite is usually made up of at least two materials out of which one is binding material called as matrix and other is a reinforcement material known as fiber. For the past ten years research is going on to explore possible composites with natural fiber like plant fibers and animal fibers. The important characteristics of composites are their strength, hardness light in weight. It is also necessary to study about the resistance of the composites for deferent chemicals. In the present work, composites prepared with epoxy (Araldite LY-556 as resin and „emu‟ bird feathers as fiber have been tested for chemical resistance. The composites were prepared by varying fiber loading (P of „emu‟ feathers ranging from 1 to 5 and length (L of feather fibers from 1 to 5 cm. The composites thus prepared were subjected to various chemicals (Acids, Alkalis, solvents etc.. Observations were plotted and studied. The results reveal that there will be weight gain for the composite samples after three days, when treated with Hydrochloric acid, Sodium carbonate, Acetic acid, Sodium hydroxide, Nitric acid and Ammonium hydroxide. Weight loss was observed for all the samples including pure epoxy when treated with Benzene, Carbon tetra chloride and Toluene.

  3. Tattoo inks: legislation, pigments, metals and chemical analysis.

    Science.gov (United States)

    Prior, Gerald

    2015-01-01

    Legal limits for chemical substances require that they are linked to clearly defined analytical methods. Present limits for certain chemicals in tattoo and permanent make-up inks do not mention analytical methods for the detection of metals, polycyclic aromatic hydrocarbons or forbidden colourants. There is, therefore, no established method for the determination of the quantities of these chemicals in tattoo and permanent make-up inks. Failing to provide an appropriate method may lead to unqualified and questionable results which often cause legal disputes that are ultimately resolved by a judge with regard to the method that should have been applied. Analytical methods are tuned to exactly what is to be found and what causes the health problems. They are extremely specific. Irrespective of which is the correct method for detecting metals in tattoo inks, the focus should be on the actual amounts of ink in the skin. CTL® has conducted experiments to determine these amounts and these experiments are crucial for toxicological evaluations and for setting legal limits. When setting legal limits, it is essential to also incorporate factors such as daily consumption, total uptake and frequency of use. A tattoo lasts for several decades; therefore, the limits that have been established for heavy metals used in drinking water or soap are not relevant. Drinking water is consumed on a daily basis and soap is used several times per week, while tattooing only occurs once. PMID:25833637

  4. Performance analysis of Isopropanol–Acetone–Hydrogen chemical heat pump

    International Nuclear Information System (INIS)

    Highlights: ► The increase of temperature of endothermic reaction reduces performance of heat pump. ► The better the performance is, the larger the number of trays. ► COP focuses on the quantity of recovered heat. ► Exergy efficiency focuses on the quantity and quality of recovered heat. - Abstract: The performance of an Isopropanol–Acetone–Hydrogen (IAH) chemical heat pump system is investigated in terms of enthalpy efficiency (COP) and exergy efficiency, in which the exothermic and endothermic reactions take place in the gas phase. The increase of reflux ratio, temperature of endothermic reaction and temperature of exothermic reaction reduces the performance of the heat pump when the other operating parameters remain unchanged. However, the performance of the IAH chemical heat pump improves with the increase of the ratio of molar quantity of hydrogen to that of acetone in the entry of exothermic reactor and the number of heat transfer units of regenerator. Generally, a better performance of the chemical heat pump corresponds to a larger number of trays in the distillation column. The performance of the system can be improved significantly after multi-parameter optimization design. The coefficient of performance (COP) pays more attention to the heat released from the exothermic reactor, while the exergy efficiency takes into consideration of both heat released from the exothermic reactor and temperature of exothermic reaction.

  5. Miniaturised wireless smart tag for optical chemical analysis applications.

    Science.gov (United States)

    Steinberg, Matthew D; Kassal, Petar; Tkalčec, Biserka; Murković Steinberg, Ivana

    2014-01-01

    A novel miniaturised photometer has been developed as an ultra-portable and mobile analytical chemical instrument. The low-cost photometer presents a paradigm shift in mobile chemical sensor instrumentation because it is built around a contactless smart card format. The photometer tag is based on the radio-frequency identification (RFID) smart card system, which provides short-range wireless data and power transfer between the photometer and a proximal reader, and which allows the reader to also energise the photometer by near field electromagnetic induction. RFID is set to become a key enabling technology of the Internet-of-Things (IoT), hence devices such as the photometer described here will enable numerous mobile, wearable and vanguard chemical sensing applications in the emerging connected world. In the work presented here, we demonstrate the characterisation of a low-power RFID wireless sensor tag with an LED/photodiode-based photometric input. The performance of the wireless photometer has been tested through two different model analytical applications. The first is photometry in solution, where colour intensity as a function of dye concentration was measured. The second is an ion-selective optode system in which potassium ion concentrations were determined by using previously well characterised bulk optode membranes. The analytical performance of the wireless photometer smart tag is clearly demonstrated by these optical absorption-based analytical experiments, with excellent data agreement to a reference laboratory instrument. PMID:24274311

  6. Development of international standards for surface analysis by ISO technical committee 201 on surface chemical analysis

    International Nuclear Information System (INIS)

    Full text: The International Organization for Standardization (ISO) established Technical Committee 201 on Surface Chemical Analysis in 1991 to develop documentary standards for surface analysis. ISO/TC 201 met first in 1992 and has met annually since. This committee now has eight subcommittees (Terminology, General Procedures, Data Management and Treatment, Depth Profiling, AES, SIMS, XPS, and Glow Discharge Spectroscopy (GDS)) and one working group (Total X-Ray Fluorescence Spectroscopy). Each subcommittee has one or more working groups to develop standards on particular topics. Australia has observer-member status on ISO/TC 201 and on all ISO/TC 201 subcommittees except GDS where it has participator-member status. I will outline the organization of ISO/TC 201 and summarize the standards that have been or are being developed. Copyright (1999) Australian X-ray Analytical Association Inc

  7. Los Alamos National Laboratory Center for direct chemical analysis of materials

    International Nuclear Information System (INIS)

    The Center for Direct Chemical Analysis at Los Alamos National Laboratory is undertaking a major effort to develop, improve, and implement direct analysis techniques for radionuclide, organic, and inorganic constituents. The Center consists of a multidisciplinary team of researchers who possess expertise in the quantitative and qualitative characterization of solid materials using a variety of analytical technologies. Materials include soils and sludges, building materials, foods, chemicals, and atmospheric gases. Direct chemical analysis techniques measure the analytes directly in the solid material with minimal sample pretreatment, whereas conventional techniques, such as atomic absorption and emission spectrochemistry, require that the solid materials be rendered in aqueous solution using concentrated acids prior to measurement. Direct chemical analysis completely bypasses the digestion process, thereby increasing the sample throughout and saving both time and money. Direct chemical analysis is unique in that it alone can conduct certain specialized but highly useful types of analysis, such as depth-profiling and the chemical structural characterization of surfaces. In addition, some direct analytical techniques eliminate the sampling step and permit rapid analysis of samples at the point of origin. Direct analysis in situ would further reduce costs and potential hazards related to sample collection and transport to the analytical laboratory

  8. Exploring the Potential for Using Inexpensive Natural Reagents Extracted from Plants to Teach Chemical Analysis

    Science.gov (United States)

    Hartwell, Supaporn Kradtap

    2012-01-01

    A number of scientific articles report on the use of natural extracts from plants as chemical reagents, where the main objective is to present the scientific applications of those natural plant extracts. The author suggests that natural reagents extracted from plants can be used as alternative low cost tools in teaching chemical analysis,…

  9. Neutron activation analysis for chemical characterization of Brazilian oxo-biodegradable plastics

    International Nuclear Information System (INIS)

    The chemical characterization of oxo-biodegradable plastic bags was performed by neutron activation analysis. The presence of several chemical elements (As, Br, Ca, Co, Cr, Fe, Hf, K, La, Na, Sb, Sc, Ta and Zn) with large variability of mass fractions amongst samples indicates that these plastics receive additives and may have been contaminated during manufacturing process thereby becoming potential environmental pollutants. (author)

  10. Identification of environmentally relevant chemicals in bibliographic databases: a comparative analysis

    DEFF Research Database (Denmark)

    Ellegaard, Ole; Wallin, Johan Albert

    2013-01-01

    Valid and reliable information on the use and effects of chemicals is a key factor in the industry and not least within many regulatory agencies. Identification data from lists of substances sometimes leads to incomplete bibliographic analysis in the major chemical databases. The present study...

  11. Analysis of solids remaining following chemical cleaning in tank 6F

    International Nuclear Information System (INIS)

    Following chemical cleaning, a solid sample was collected and submitted to Savannah River National Laboratory (SRNL) for analysis. SRNL analyzed this sample by X-ray Diffraction (XRD) and scanning electron microscopy (SEM) to determine the composition of the solids remaining in Tank 6F and to assess the effectiveness of the chemical cleaning process.

  12. Forecasting global developments in the basic chemical industry for environmental policy analysis

    NARCIS (Netherlands)

    Broeren, M.L.M.; Saygin, D.; Patel, M.K.

    2014-01-01

    The chemical sector is the largest industrial energy user, but detailed analysis of its energy use developments lags behind other energy-intensive sectors. A cost-driven forecasting model for basic chemicals production is developed, accounting for regional production costs, demand growth and stock t

  13. Chemical analysis of acoustically levitated drops by Raman spectroscopy.

    Science.gov (United States)

    Tuckermann, Rudolf; Puskar, Ljiljana; Zavabeti, Mahta; Sekine, Ryo; McNaughton, Don

    2009-07-01

    An experimental apparatus combining Raman spectroscopy with acoustic levitation, Raman acoustic levitation spectroscopy (RALS), is investigated in the field of physical and chemical analytics. Whereas acoustic levitation enables the contactless handling of microsized samples, Raman spectroscopy offers the advantage of a noninvasive method without complex sample preparation. After carrying out some systematic tests to probe the sensitivity of the technique to drop size, shape, and position, RALS has been successfully applied in monitoring sample dilution and preconcentration, evaporation, crystallization, an acid-base reaction, and analytes in a surface-enhanced Raman spectroscopy colloidal suspension. PMID:19418043

  14. Electron spectroscopies for simultaneous chemical and electrical analysis

    International Nuclear Information System (INIS)

    Electrons are used as spectroscopic probes to determine elemental composition and chemistry, and are also useful as probes of the electrical properties of devices and materials. In this paper, four examples with incident and emitted electrons were used to evaluate the electrical and chemical properties of samples. These examples were the electrical conductivity of an Ag-epoxy composite, the electric field in an avalanche photodiode near breakdown, the mechanism of conductivity of semi-insulating polycrystalline films, and the charge at an oxide/semiconductor interface for high-k applications. This kind of work is very much in the spirit of the work done by Prof. Sefik Suzer.

  15. Statistical analysis of DNT detection using chemically functionalized microcantilever arrays

    DEFF Research Database (Denmark)

    Bosco, Filippo; Bache, M.; Hwu, E.-T.;

    2012-01-01

    The need for miniaturized and sensitive sensors for explosives detection is increasing in areas such as security and demining. Micrometer sized cantilevers are often used for label-free detection, and have previously been reported to be able to detect explosives. However, only a few measurements...... on the chemically treated surfaces results in significant bending of the cantilevers and in a decrease of their resonant frequencies. We present averaged measurements obtained from up to 72 cantilevers being simultaneously exposed to the same sample. Compared to integrated reference cantilevers with...

  16. Environmental Impact Assessment for Socio-Economic Analysis of Chemicals

    DEFF Research Database (Denmark)

    Calow, Peter; Biddinger, G; Hennes, C;

    This report describes the requirements for, and illustrates the application of, a methodology for a socio-economic analysis (SEA) especially as it might be adopted in the framework of REACH.......This report describes the requirements for, and illustrates the application of, a methodology for a socio-economic analysis (SEA) especially as it might be adopted in the framework of REACH....

  17. A study of quantitative chemical state analysis on cerium surface by using auger electron spectroscopy and factor analysis

    International Nuclear Information System (INIS)

    A reaction with oxygen during oxygen exposure to Cerium metal surface under ultra high vacuum condition and depth profiling on formed Cerium oxide layer were investigated in term of chemical state analysis by Auger electron spectroscopy (AES) and by factor analysis. Principal component analysis (PCA) on Ce NON Auger spectra suggested that three physically meaningful components existed from the analyzed data in both cases. After the PCA, three spectra were extracted from the data and these showed significant peak shape changes in each spectrum which were corresponding to different chemical states. In addition, the profiles constructed by factor analysis showed the chemical state changes on the Cerium metal surface during oxidation or chemical depth distributions in the oxide layer. (author)

  18. Chemical risk evaluation, importance of the risk analysis framework uses: Latin America development restrictions

    International Nuclear Information System (INIS)

    The power point presentation is about reach and results of the risk analysis in Venezuela, chemical dangers in food, human damage, injuries , technologies news in fodd development, toxicity, microbiological risk, technical recommendations

  19. Literature survey of chemical analysis by thermal neutron induced capture gamma ray spectrometry

    International Nuclear Information System (INIS)

    A brief discussion of the principles and techniques of chemical analysis by neutron capture gamma radiation is presented, and the widely scattered literature is collected into a single table arranged by element measured

  20. Chemical analysis and sampling techniques for geothermal fluids and gases at the Fenton Hill Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Trujillo, P.E.; Counce, D.; Grigsby, C.O.; Goff, F.; Shevenell, L.

    1987-06-01

    A general description of methods, techniques, and apparatus used for the sampling, chemical analysis, and data reporting of geothermal gases and fluids is given. Step-by-step descriptions of the procedures are included in the appendixes.

  1. Toxic hazard and chemical analysis of leachates from furfurylated wood.

    Science.gov (United States)

    Pilgård, Annica; Treu, Andreas; van Zeeland, Albert N T; Gosselink, Richard J A; Westin, Mats

    2010-09-01

    The furfurylation process is an extensively investigated wood modification process. Furfuryl alcohol molecules penetrate into the wood cell wall and polymerize in situ. This results in a permanent swelling of the wood cell walls. It is unclear whether or not chemical bonds exist between the furfuryl alcohol polymer and the wood. In the present study, five different wood species were used, both hardwoods and softwoods. They were treated with three different furfurylation procedures and leached according to three different leaching methods. The present study shows that, in general, the leachates from furfurylated wood have low toxicity. It also shows that the choice of leaching method is decisive for the outcome of the toxicity results. Earlier studies have shown that leachates from wood treated with furfuryl alcohol prepolymers have higher toxicity to Vibrio fischeri than leachates from wood treated with furfuryl alcohol monomers. This is probably attributable to differences in leaching of chemical compounds. The present study shows that this difference in the toxicity most likely cannot be attributed to maleic acid, furan, furfural, furfuryl alcohol, or 2-furoic acid. However, the difference might be caused by the two substances 5-hydroxymethylfurfural and 2,5-furandimethanol. The present study found no difference in the amount of leached furfuryl alcohol between leachates from furfurylated softwood and furfurylated hardwood species. Earlier studies have indicated differences in grafting of furfuryl alcohol to lignin. However, nothing was found in the present study that could support this. The leachates of furfurylated wood still need to be PMID:20821648

  2. THE INTERACTIVE DECISION COMMITTEE FOR CHEMICAL TOXICITY ANALYSIS.

    Science.gov (United States)

    Kang, Chaeryon; Zhu, Hao; Wright, Fred A; Zou, Fei; Kosorok, Michael R

    2012-01-01

    We introduce the Interactive Decision Committee method for classification when high-dimensional feature variables are grouped into feature categories. The proposed method uses the interactive relationships among feature categories to build base classifiers which are combined using decision committees. A two-stage or a single-stage 5-fold cross-validation technique is utilized to decide the total number of base classifiers to be combined. The proposed procedure is useful for classifying biochemicals on the basis of toxicity activity, where the feature space consists of chemical descriptors and the responses are binary indicators of toxicity activity. Each descriptor belongs to at least one descriptor category. The support vector machine, the random forests, and the tree-based AdaBoost algorithms are utilized as classifier inducers. Forward selection is used to select the best combinations of the base classifiers given the number of base classifiers. Simulation studies demonstrate that the proposed method outperforms a single large, unaggregated classifier in the presence of interactive feature category information. We applied the proposed method to two toxicity data sets associated with chemical compounds. For these data sets, the proposed method improved classification performance for the majority of outcomes compared to a single large, unaggregated classifier. PMID:24415822

  3. Chemical analysis of steel (citations from the NTIS Data Base). Report for 1964-Apr 80

    Energy Technology Data Exchange (ETDEWEB)

    Cavagnaro, D.M.

    1980-05-01

    Information is cited on chemical analysis of boron, nitrogen, hydrogen, sulfur, silicon, carbon, oxygen, aluminum, rare earths, and other trace elements in steel. In addition, research on the determination of major elements, including iron, is covered. New techniques and refinement of older techniques, including x-ray fluorescence, spectroscopy, chromatography, activation analysis, and wet chemical methods are also included. (This updated bibliography contains 240 abstracts, 14 of which are new entries to the previous edition.)

  4. Applications of a versatile technique for trace analysis: atmospheric pressure negative chemical ionization.

    OpenAIRE

    Thomson, B A; Davidson, W R; Lovett, A M

    1980-01-01

    The ability to use ambient air as a carrier and reagent gas in an atmospheric pressure chemical ionization source allows instantaneous air analysis to be combined with hypersensitivity toward a wide variety of compounds. The TAGA (Trace Atmospheric Gas Analyser) is an instrument which is designed to use both positive and negative atmospheric pressure chemical ionization (APCI) for trace gas analysis; this paper describes several applications of negative APCI which demonstrates that the techni...

  5. ANALYSIS OF THE CHEMICAL COMPOSITION AND MORPHOLOGICAL STRUCTURE OF BANANA PSEUDO-STEM

    OpenAIRE

    Kun Li; Shiyu Fu; Huaiyu Zhan; Yao Zhan; Lucian A. Lucia

    2010-01-01

    An analysis of the chemical composition and anatomical structure of banana pseudo-stem was carried out using Light Microscopy (LM), Scanning Electron Microscopy (SEM), and Confocal Laser Scanning Microscopy (CLSM). The chemical analysis indicated there is a high holocellulose content and low lignin content in banana pseudo-stem compared with some other non-wood fiber resources. These results demonstrate that the banana pseudo-stem has potential value for pulping. In addition, we report for th...

  6. FINITE ELEMENT METHOD AND ANALYSIS FOR CHEMICAL-FLOODING SIMULATION

    Institute of Scientific and Technical Information of China (English)

    YUAN Yirang

    2000-01-01

    This article discusses the enhanced oil recovery numerical simulation of the chemical-flooding (such as surfactants, alcohol, polymers) composed of three-dimensional multicomponent, multiphase and incompressible mixed fluids. The mathematical model can be described as a coupled system of nonlinear partial differential equations with initialboundary value problems. From the actual conditions such as the effect of cross interference and the three-dimensional characteristic of large-scale science-engineering computation, this article puts forward a kind of characteristic finite element fractional step schemes and obtain the optimal order error estimates in L2 norm. Thus we have thoroughly solved the well-known theoretical problem proposed by a famous scientist, R. E. Ewing.

  7. Nanoscale chemical analysis and imaging of solid oxide cells

    DEFF Research Database (Denmark)

    Hauch, Anne; Bowen, Jacob R.; Kuhn, Luise Theil;

    2008-01-01

    The performance of solid oxide cells (SOCs) is highly dependent on triple phase boundaries (TPBs). Therefore, detailed TPB characterization is crucial for their further development. We demonstrate that it is possible to prepare a similar to 50 nm thick transmission electron microscopy (TEM) lamella...... of the interface between the dense ceramic electrolyte and the porous metallic/ceramic hydrogen electrode of an SOC using focused ion beam milling. We show combined TEM/scanning TEM/energy-dispersive spectroscopy investigations of the nanostructure at the TPBs in a high-performance SOC. The chemical...... composition of nanoscale impurity phases at the TPBs has been obtained with a few nanometers lateral resolution. (c) 2008 The Electrochemical Society....

  8. Chemical weapons detection by fast neutron activation analysis techniques

    International Nuclear Information System (INIS)

    A neutron diagnostic experimental apparatus has been tested for nondestructive verification of sealed munitions. Designed to potentially satisfy a significant number of van-mobile requirements, this equipment is based on an easy to use industrial sealed tube neutron generator that interrogates the munitions of interest with 14 MeV neutrons. Gamma ray spectra are detected with a high purity germanium detector, especially shielded from neutrons and gamma ray background. A mobile shell holder has been used. Possible configurations allow the detection, in continuous or in pulsed modes, of gamma rays from neutron inelastic scattering, from thermal neutron capture, and from fast or thermal neutron activation. Tests on full scale sealed munitions with chemical simulants show that those with chlorine (old generation materials) are detectable in a few minutes, and those including phosphorus (new generation materials) in nearly the same time. (orig.)

  9. Synthesis and analysis in studies of chemical evolution

    Science.gov (United States)

    Ponnamperuma, C.; Hobish, M. K.; Kobayashi, K.; Hua, L. L.; Senaratne, N.

    1986-01-01

    Studies of the various processes that may have given rise to life on the Earth have demonstrated the appropriateness of an approach that makes use of analysis and synthesis. Analysis of extraterrestrial samples in the form of meteorites has demonstrated the presence of several precursors of biomolecules, most notably a full suite of nucleic acid bases and nucleotides of biological significance. These species were determined after exhaustive extraction of the sample and subsequent analysis using HPLC, GC, MS, and GC-MS. Procedural blanks indicate that these molecules are likely not the result of contamination during the extraction and analysis process. Similar species were found as products of spark discharge experiments in atmospheres thought to mimic primitive Earth conditions. These results indicate that the basic chemistry underlying these syntheses is common, and that life may not be unique to the Earth. Studies underway in the laboratory make use of proton nuclear magnetic resonance spectroscopy as a probe to assess associations between selected amino acids and any of several nucleotides comprising their genetic code and genetic anticode sequences. These studies demonstrate a clear selectivity by the anticode sequences, thus confirming the hydrophobicity studies performed by Lacey et al. These studies further support the contention that life is likely a natural result of the physics and chemistry of the universe.

  10. Chemical analysis applied to the radiation sterilization of solid ketoprofen

    Science.gov (United States)

    Colak, S.; Maquille, A.; Tilquin, B.

    2006-01-01

    The aim of this work is to investigate the feasibility of radiation sterilization of ketoprofen from a chemical point of view. Although irradiated ketoprofen has already been studied in the literature [Katusin-Razem et al., Radiat. Phys. Chem. 73 111-116 (2005)], new results, on the basis of electron spin resonance (ESR) measurements and the use of hyphenated techniques (GC-MS and LC-MS), are obtained. The ESR spectra of irradiated ketoprofen consists of four unresolved resonance peaks and the mean G-value of ketoprofen is found to be 4 +/- 0.9 nmoles/J, which is very small. HPLC-UV analyses indicate that no significant loss of ketoprofen is detected after irradiation. LC-MS-MS analyses show that the structures of the non-volatile final products are similar to ketoprofen. Benzaldehyde is detected in the irradiated samples after dynamic-extraction GC-MS. The analyses show that ketoprofen is radioresistant and therefore might be radiosterilized.

  11. Sampling and chemical analysis of urban street runoff

    International Nuclear Information System (INIS)

    In order to characterize the environmentally relevant physical and chemical properties of urban street runoff, an automatic sampling device was developed. Precipitation samples were collected together with runoff samples. Organic and inorganic compounds were analysed in the runoff. Dissolved and particle bound substances were analysed separately. The concentrations in runoff are generally considerably higher than in precipitation. Concentrations of lead, fluoranthene and benzo(a)pyrene, in particular are higher in runoffs at sites with high traffic densities than at sites with low traffic densities. Preceding dry period normally has no effect on the measured concentrations. The typical chemograph of a dissolved substance shows a maximum at the beginning of the event dropping quickly to a minimum, which often coincides with the maximum in runoff rate. A slight rise is observed with decreasing runoff rates at the end of the event. Applying a mathematical model, chemographs may be described by three terms: - Relatively large amounts of easily soluble material at the beginning of the event decrease with increasing runoff. Conservative behaviour is assumed. - A part which varies inversely to the runoff rate. This term assumes zero-order kinetics; the amount dissolved from surfaces is constant with time. - A small constant term. Concentrations of particle bound substances correlate with amounts of total suspended solids. Frequently a negative correlation between the specific concentration of substances and the concentration of total suspended solids is observed. (orig.)

  12. Hydrocarbon analysis using desorption atmospheric pressure chemical ionization

    KAUST Repository

    Jjunju, Fred P M

    2013-07-01

    Characterization of the various petroleum constituents (hydronaphthalenes, thiophenes, alkyl substituted benzenes, pyridines, fluorenes, and polycyclic aromatic hydrocarbons) was achieved under ambient conditions without sample preparation by desorption atmospheric pressure chemical ionization (DAPCI). Conditions were chosen for the DAPCI experiments to control whether ionization was by proton or electron transfer. The protonated molecule [M+H]+ and the hydride abstracted [MH]+ form were observed when using an inert gas, typically nitrogen, to direct a lightly ionized plasma generated by corona discharge onto the sample surface in air. The abundant water cluster ions generated in this experiment react with condensed-phase functionalized hydrocarbon model compounds and their mixtures at or near the sample surface. On the other hand, when naphthalene was doped into the DAPCI gas stream, its radical cation served as a charge exchange reagent, yielding molecular radical cations (M+) of the hydrocarbons. This mode of sample ionization provided mass spectra with better signal/noise ratios and without unwanted side-products. It also extended the applicability of DAPCI to petroleum constituents which could not be analyzed through proton transfer (e.g., higher molecular PAHs such as chrysene). The thermochemistry governing the individual ionization processes is discussed and a desorption/ionization mechanism is inferred. © 2012 Elsevier B.V.

  13. Virus and Bacterial Cell Chemical Analysis by NanoSIMS

    Energy Technology Data Exchange (ETDEWEB)

    Weber, P; Holt, J

    2008-07-28

    In past work for the Department of Homeland Security, the LLNL NanoSIMS team has succeeded in extracting quantitative elemental composition at sub-micron resolution from bacterial spores using nanometer-scale secondary ion mass spectrometry (NanoSIMS). The purpose of this task is to test our NanoSIMS capabilities on viruses and bacterial cells. This initial work has proven successful. We imaged Tobacco Mosaic Virus (TMV) and Bacillus anthracis Sterne cells using scanning electron microscopy (SEM) and then analyzed those samples by NanoSIMS. We were able resolve individual viral particles ({approx}18 nm by 300 nm) in the SEM and extract correlated elemental composition in the NanoSIMS. The phosphorous/carbon ratio observed in TMV is comparable to that seen in bacterial spores (0.033), as was the chlorine/carbon ratio (0.11). TMV elemental composition is consistent from spot to spot, and TMV is readily distinguished from debris by NanoSIMS analysis. Bacterial cells were readily identified in the SEM and relocated in the NanoSIMS for elemental analysis. The Ba Sterne cells were observed to have a measurably lower phosphorous/carbon ratio (0.005), as compared to the spores produced in the same run (0.02). The chlorine/carbon ratio was approximately 2.5X larger in the cells (0.2) versus the spores (0.08), while the fluorine/carbon ratio was approximately 10X lower in the cells (0.008) than the spores (0.08). Silicon/carbon ratios for both cells and spores encompassed a comparable range. The initial data in this study suggest that high resolution analysis is useful because it allows the target agent to be analyzed separate from particulates and other debris. High resolution analysis would also be useful for trace sample analysis. The next step in this work is to determine the potential utility of elemental signatures in these kinds of samples. We recommend bulk analyses of media and agent samples to determine the range of media compositions in use, and to determine how

  14. Advances in Mid-Infrared Spectroscopy for Chemical Analysis.

    Science.gov (United States)

    Haas, Julian; Mizaikoff, Boris

    2016-06-12

    Infrared spectroscopy in the 3-20 μm spectral window has evolved from a routine laboratory technique into a state-of-the-art spectroscopy and sensing tool by benefitting from recent progress in increasingly sophisticated spectra acquisition techniques and advanced materials for generating, guiding, and detecting mid-infrared (MIR) radiation. Today, MIR spectroscopy provides molecular information with trace to ultratrace sensitivity, fast data acquisition rates, and high spectral resolution catering to demanding applications in bioanalytics, for example, and to improved routine analysis. In addition to advances in miniaturized device technology without sacrificing analytical performance, selected innovative applications for MIR spectroscopy ranging from process analysis to biotechnology and medical diagnostics are highlighted in this review. PMID:27070183

  15. Advances in Mid-Infrared Spectroscopy for Chemical Analysis

    Science.gov (United States)

    Haas, Julian; Mizaikoff, Boris

    2016-06-01

    Infrared spectroscopy in the 3–20 μm spectral window has evolved from a routine laboratory technique into a state-of-the-art spectroscopy and sensing tool by benefitting from recent progress in increasingly sophisticated spectra acquisition techniques and advanced materials for generating, guiding, and detecting mid-infrared (MIR) radiation. Today, MIR spectroscopy provides molecular information with trace to ultratrace sensitivity, fast data acquisition rates, and high spectral resolution catering to demanding applications in bioanalytics, for example, and to improved routine analysis. In addition to advances in miniaturized device technology without sacrificing analytical performance, selected innovative applications for MIR spectroscopy ranging from process analysis to biotechnology and medical diagnostics are highlighted in this review.

  16. Archaeological and chemical analysis of Tell el Yahudiyeh ware

    International Nuclear Information System (INIS)

    Typological and geographic analyses indicate that Tell el Yahudiyeh ware (found in Cyprus, Egypt, Nubia, and the Levant during the Middle Bronze period, c. 1750-1550 B.C.) were probably manufactured in two areas, the Nile Valley and the Levant. Activation analysis was carried out and correlated with the archaeological analyses. Results confirm the two ''families'' of the ware, one Egyptian and one Levantine. Speculations are offered on the social interaction of the period. 11 figures, 2 tables

  17. Controlling organic chemical hazards in food manufacturing: a hazard analysis critical control points (HACCP) approach.

    Science.gov (United States)

    Ropkins, K; Beck, A J

    2002-08-01

    Hazard analysis by critical control points (HACCP) is a systematic approach to the identification, assessment and control of hazards. Effective HACCP requires the consideration of all hazards, i.e., chemical, microbiological and physical. However, to-date most 'in-place' HACCP procedures have tended to focus on the control of microbiological and physical food hazards. In general, the chemical component of HACCP procedures is either ignored or limited to applied chemicals, e.g., food additives and pesticides. In this paper we discuss the application of HACCP to a broader range of chemical hazards, using organic chemical contaminants as examples, and the problems that are likely to arise in the food manufacturing sector. Chemical HACCP procedures are likely to result in many of the advantages previously identified for microbiological HACCP procedures: more effective, efficient and economical than conventional end-point-testing methods. However, the high costs of analytical monitoring of chemical contaminants and a limited understanding of formulation and process optimisation as means of controlling chemical contamination of foods are likely to prevent chemical HACCP becoming as effective as microbiological HACCP. PMID:12224422

  18. Wet chemical analysis for the semiconductor industry—a total view

    Science.gov (United States)

    Balazs, Marjorie K.

    1998-11-01

    The analysis of liquids to obtain information about semiconductor materials is known in the industry as "wet chemistry" and has been used since the beginning of the production of IC's. However, the analytical procedures never gained any significant attention until the mid 70's when the absolute measurement of phosphorus in PSG films by wet chemical analysis was incorporated by several industrial labs as the standard method of analysis. Today, over 120 different procedures are used to gain specific information about incoming and processed materials used in the industry. These procedures cover ultra pure water, chemicals, thin films, and wafer cleanliness. Furthermore, they are used to evaluate the cleanliness of reactors, cleanrooms, and components of all kinds that are used in cleanrooms, wet benches and reactors. This paper will cover a total look at the applications of wet chemical processes and the usefulness of the data obtained from these analytical techniques. The paper will cover not only those tests that one would expect to be done by wet processes such as the analysis of metals in chemicals, but will also cover many unusual applications of wet chemical analysis such as their usefulness in evaluating products from a variety of reactors. Included in this part of the presentation will be a unique application to determine ion implantation contaminants and recent advances for analyzing 300mm wafers without breaking them and the analysis of contamination metals in copper thin films. Actual data will be provided for each of the analytical techniques presented.

  19. Analysis of some chemical nutrients in four Brazilian tropical seaweeds

    Directory of Open Access Journals (Sweden)

    José Gerardo Carneiro

    2014-05-01

    Full Text Available Seaweeds have various chemical components with beneficial effects for human use; however, their nutritional values in Brazilian species are not well known. This study aimed to evaluate the content of water, ash, protein, carbohydrate, and lipid in four seaweeds (Hypnea musciformis, Solieria filiformis, Caulerpa cupressoides and C. mexicana. Algal constituents were determined by difference, gravimetric or colorimetric method, being the values expressed as g 100 g-1 dehydrated weight (d.w.. Results revealed that the water (10.7 ± 0.18-15.06 ± 1.14 g 100 g-1 d.w., ash (7.79 ± 0.87-15.12 ± 0.51 g 100 g-1 d.w, protein (17.12 ± 0.99-20.79 ± 0.58 g 100 g-1 d.w., lipid (0.33 ± 0.01-3.77 ± 0.13 g 100 g-1 d.w. and carbohydrate (38.07 ± 0.32-54.24 ± 0.157 g 100 g-1 d.w. contents varied between the species (p < 0.05. H. musciformis and S. filiformis (Rhodophyta had highest ash contents (14.14 ± 1.23-15.12 ± 0.51 g 100 g-1 d.w., whereas lipids were higher for Caulerpa species (Chlorophyta (1.52 ± 0.17-3.77 ± 0.13 g 100 g-1 d.w. (p < 0.05. Protein and carbohydrate were the most sources in all the species. Therefore, the studied seaweeds could be a potential source of food ingredients for diets.

  20. Different Models Used to Interpret Chemical Changes: Analysis of a Curriculum and Its Impact on French Students' Reasoning

    Science.gov (United States)

    Kermen, Isabelle; Meheut, Martine

    2009-01-01

    We present an analysis of the new French curriculum on chemical changes describing the underlying models and highlighting their relations to the empirical level. The authors of the curriculum introduced a distinction between the chemical change of a chemical system and the chemical reactions that account for it. We specify the different roles of…

  1. A methodology for chemical hazards analysis at nuclear fuels reprocessing plants

    International Nuclear Information System (INIS)

    The Savannah River Laboratory employs a formal methodology for chemical hazards analysis primarily for use in the risk assessment of its nuclear fuels reprocessing plants. The methodology combines interactive matrices for reactions of available materials, fault tree analysis, human factors, and extensive data banks on the operating history of the plants. Examples illustrate the methodology and a related data bank

  2. Inorganic chemical analysis of environmental materials—A lecture series

    Science.gov (United States)

    Crock, J.G.; Lamothe, P.J.

    2011-01-01

    At the request of the faculty of the Colorado School of Mines, Golden, Colorado, the authors prepared and presented a lecture series to the students of a graduate level advanced instrumental analysis class. The slides and text presented in this report are a compilation and condensation of this series of lectures. The purpose of this report is to present the slides and notes and to emphasize the thought processes that should be used by a scientist submitting samples for analyses in order to procure analytical data to answer a research question. First and foremost, the analytical data generated can be no better than the samples submitted. The questions to be answered must first be well defined and the appropriate samples collected from the population that will answer the question. The proper methods of analysis, including proper sample preparation and digestion techniques, must then be applied. Care must be taken to achieve the required limits of detection of the critical analytes to yield detectable analyte concentration (above "action" levels) for the majority of the study's samples and to address what portion of those analytes answer the research question-total or partial concentrations. To guarantee a robust analytical result that answers the research question(s), a well-defined quality assurance and quality control (QA/QC) plan must be employed. This QA/QC plan must include the collection and analysis of field and laboratory blanks, sample duplicates, and matrix-matched standard reference materials (SRMs). The proper SRMs may include in-house materials and/or a selection of widely available commercial materials. A discussion of the preparation and applicability of in-house reference materials is also presented. Only when all these analytical issues are sufficiently addressed can the research questions be answered with known certainty.

  3. The Matthew effect in environmental science publication: A bibliometric analysis of chemical substances in journal articles

    DEFF Research Database (Denmark)

    Grandjean, Philippe; Eriksen, Mette Lindholm; Ellegaard, Ole;

    2011-01-01

    publication rates. The persistence in the scientific literature of the top-20 chemicals was only weakly related to their publication in journals with a high impact factor, but some substances achieved high citation rates. Conclusions The persistence of some environmental chemicals in the scientific literature......Background While environmental research addresses scientific questions of possible societal relevance, it is unclear to what degree research focuses on environmental chemicals in need of documentation for risk assessment purposes. Methods In a bibliometric analysis, we used SciFinder to extract...... Chemical Abstract Service (CAS) numbers for chemicals addressed by publications in the 78 major environmental science journals during 2000-2009. The Web of Science was used to conduct title searches to determine longterm trends for prominent substances and substances considered in need of research...

  4. Instrumental neutron activation analysis, a valuable link in chemical metrology

    International Nuclear Information System (INIS)

    Instrumental neutron activation analysis (INAA) is sufficiently versatile to establish a direct link to the amount of substance determined. The inherent quality parameters of INAA, such as being virtually free of blank, having fully accountable effects of matrix and physical form, and operating over a huge range of amounts, allows the comparison of a mole (or its fraction) of a pure element with the amount of substance in the sample analyzed with the same direct relationship as a beam balance provides. Indeed, varieties of this approach are in common use in INAA in the comparator methods of quantitation. To eliminate possible perturbations of the traceability chain as they may occur in common INAA practice, experimental measurements have been set up that only involve the fraction of a mole of the element(s) of interest in form of the pure element, compound or certified standard and the unknown sample. This principle has been used in INAA measurements for certification value assignment of high temperature alloy SRMs. To further demonstrate the performance parameters of INAA, we selected the determination of chromium in SRM 1152a Stainless Steel by direct non-destructive comparison with the pure metal in form of crystalline chromium. The measurements were validated with weighed aliquots of SRM 3112a dried on filter paper pellets. The experimental results do not show deviations beyond the uncertainties of the SRMs (≤ 0.2 % relative), and the assessment of the uncertainty budget indicates that expanded uncertainties of ≤ 0.3 % are achievable. The measurements demonstrate that INAA can meet the CCQM definition of a primary ratio method of analysis

  5. Theoretical considerations of Flow Injection Analysis in the Absence of Chemical Reactions

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    2000-01-01

    The fundamental mechanism of flow injection analysis (FIA) is assumed to be simple dissusion and the response of the detector is included in a model description that provide information about the shape of the FIA peak in terms of, basically, five parameters. Two of the five parameters are associa...... any deviation from the features of the present model and the results of a tentative chemical reaction with one of the test compounds, is related to chemical kinetics....

  6. Physico Chemical Analysis of Sapota (Manilkara zapota) Coated by Edible Aloe Vera Gel

    OpenAIRE

    N.Padmaja; S. John Don Bosco; J. Sudhakara Rao

    2015-01-01

    The physical and chemical characteristics of the fruit have immense significance as they ultimately affect the quality of processed productsprepared from them. Over ripening of Sapota (Manilkara zapota) fruits at the post-harvest stage usually results in dramatic decline in quality.In the present study, physico chemical analysis (which includes Weight loss, Colour, Texture, TSS, pH, TA and Ascorbic acid content) ofedible Aloe vera gel coated Sapota fruits packed in LDPE and stored at 15 ± 2? ...

  7. Permeability and chemical analysis of aromatic polyamide based membranes exposed to sodium hypochlorite

    OpenAIRE

    Ettori, Axel; Gaudichet-Maurin, Emmanuelle; Schrotter, Jean-Christophe; Aimar, Pierre; Causserand, Christel

    2011-01-01

    In this study, a cross-linked aromatic polyamide based reverse osmosis membrane was exposed to variable sodium hypochlorite ageing conditions (free chlorine concentration, solution pH) and the resulting evolutions of membrane surface chemical and structural properties were monitored. Elemental and surface chemical analysis performed using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR), showed that chlorine is essentially incorporated on the polyamide...

  8. Embedded Fragments from U.S. Military Personnel—Chemical Analysis and Potential Health Implications

    OpenAIRE

    Centeno, José A.; Duane A. Rogers; Gijsbert B. van der Voet; Elisa Fornero; Lingsu Zhang; Mullick, Florabel G.; Chapman, Gail D.; Olabisi, Ayodele O.; Wagner, Dean J.; Alexander Stojadinovic; Potter, Benjamin K.

    2014-01-01

    Background: The majority of modern war wounds are characterized by high-energy blast injuries containing a wide range of retained foreign materials of a metallic or composite nature. Health effects of retained fragments range from local or systemic toxicities to foreign body reactions or malignancies, and dependent on the chemical composition and corrosiveness of the fragments in vivo. Information obtained by chemical analysis of excised fragments can be used to guide clinical decisions rega...

  9. Statistic analysis of grouping in evaluation of the behavior of stable chemical elements and physical-chemical parameters in effluent from uranium mining

    International Nuclear Information System (INIS)

    The Ore Treatment Unit (UTM) is a uranium mine off. The statistical analysis of clustering was used to evaluate the behavior of stable chemical elements and physico-chemical variables in their effluents. The use of cluster analysis proved effective in the evaluation, allowing to identify groups of chemical elements in physico-chemical variables and group analyzes (element and variables ). As a result, we can say, based on the analysis of the data, a strong link between Ca and Mg and between Al and TR2O3 (rare earth oxides) in the UTM effluents. The SO4 was also identified as strongly linked to total solids and dissolved and these linked to electrical conductivity. Other associations existed, but were not as strongly linked. Additional collections for seasonal evaluation are required so that assessments can be confirmed. Additional statistics analysis (ordination techniques) should be used to help identify the origins of the groups identified in this analysis. (author)

  10. Analysis of abused drugs by selected ion monitoring: quantitative comparison of electron impact and chemical ionization

    International Nuclear Information System (INIS)

    A comparison was made of the relative sensitivities of electron impact and chemical ionization when used for selected ion monitoring analysis of commonly abused drugs. For most of the drugs examined chemical ionization using ammonia as the reactant gas gave the largest single m/e ion current response per unit weight of sample. However, if maximum sensitivity is desired it is important to evaluate electron impact and chemical ionization with respect to both maximum response and degree of interference from background and endogenous materials

  11. Environmental Chemical Analysis (by B. B. Kebbekus and S. Mitra)

    Science.gov (United States)

    Bower, Reviewed By Nathan W.

    1999-11-01

    This text helps to fill a void in the market, as there are relatively few undergraduate instrumental analysis texts designed specifically for the expanding population of environmental science students. R. N. Reeve's introductory, open-learning Environmental Analysis (Wiley, 1994) is one of the few, and it is aimed at a lower level and is less appropriate for traditional classroom study. Kebbekus and Mitra's book appears to be an update of I. Marr and M. Cresser's excellent 1983 text by the same name (and also published under the Chapman and Hall imprint). It assumes no background in instrumental methods of analysis but it does depend upon a good general chemistry background in kinetic and equilibrium calculations and the standard laboratory techniques found in a classical introduction to analytical chemistry. The slant taken by the authors is aimed more toward engineers, not only in the choice of topics, but also in how they are presented. For example, the statistical significance tests presented follow an engineering format rather than the standard used in analytical chemistry. This approach does not detract from the book's clarity. The writing style is concise and the book is generally well written. The earlier text, which has become somewhat of a classic, took the unusual step of teaching the instruments in the context of their environmental application. It was divided into sections on the "atmosphere", the "hydrosphere", the "lithosphere", and the "biosphere". This text takes a similar approach in the second half, with chapters on methods for air, water, and solid samples. Users who intend to use the book as a text instead of a reference will appreciate the addition of chapters in the first half of the book on spectroscopic, chromatographic, and mass spectrometric methods. The six chapters in these two parts of the book along with four chapters scattered throughout on environmental measurements, sampling, sample preparation, and quality assurance make a nice

  12. The dilemma in prioritizing chemicals for environmental analysis: known versus unknown hazards.

    Science.gov (United States)

    Anna, Sobek; Sofia, Bejgarn; Christina, Rudén; Magnus, Breitholtz

    2016-08-10

    A major challenge for society is to manage the risks posed by the many chemicals continuously emitted to the environment. All chemicals in production and use cannot be monitored and science-based strategies for prioritization are essential. In this study we review available data to investigate which substances are included in environmental monitoring programs and published research studies reporting analyses of chemicals in Baltic Sea fish between 2000 and 2012. Our aim is to contribute to the discussion of priority settings in environmental chemical monitoring and research, which is closely linked to chemical management. In total, 105 different substances or substance groups were analyzed in Baltic Sea fish. Polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) were the most studied substances or substance groups. The majority, 87%, of all analyses comprised 20% of the substances or substance groups, whereas 46 substance groups (44%) were analyzed only once. Almost three quarters of all analyses regarded a POP-substance (persistent organic pollutant). These results demonstrate that the majority of analyses on environmental contaminants in Baltic Sea fish concern a small number of already regulated chemicals. Legacy pollutants such as POPs pose a high risk to the Baltic Sea due to their hazardous properties. Yet, there may be a risk that prioritizations for chemical analyses are biased based on the knowns of the past. Such biases may lead to society failing in identifying risks posed by yet unknown hazardous chemicals. Alternative and complementary ways to identify priority chemicals are needed. More transparent communication between risk assessments performed as part of the risk assessment process within REACH and monitoring programs, and information on chemicals contained in consumer articles, would offer ways to identify chemicals for environmental analysis. PMID:27222376

  13. Chemical analysis of Asymptotic Giant Branch stars in M62

    CERN Document Server

    Lapenna, E; Ferraro, F R; Origlia, L; Lanzoni, B; Massari, D; Dalessandro, E

    2015-01-01

    We have collected UVES-FLAMES high-resolution spectra for a sample of 6 asymptotic giant branch (AGB) and 13 red giant branch (RGB) stars in the Galactic globular cluster M62 (NGC6266). Here we present the detailed abundance analysis of iron, titanium, and light-elements (O, Na, Al and Mg). For the majority (5 out 6) of the AGB targets we find that the abundances, of both iron and titanium, determined from neutral lines are significantly underestimated with respect to those obtained from ionized features, the latter being, instead, in agreement with those measured for the RGB targets. This is similar to recent findings in other clusters and may suggest the presence of Non-Local Thermodynamical Equilibrium (NLTE) effects. In the O-Na, Al-Mg and Na-Al planes, the RGB stars show the typical correlations observed for globular cluster stars. Instead, all the AGB targets are clumped in the regions where first generation stars are expected to lie, similarly to what recently found for the AGB population of NGC6752. W...

  14. Chemical and Nutrient Analysis of Gingerbread Plum (Neocarya macrophylla Seeds

    Directory of Open Access Journals (Sweden)

    Tidjani Amza

    2010-07-01

    Full Text Available The proximate composition of gingerbread plum (Neocarya macrophylla seeds, mineral, fatty acid and amino acid compositions were evaluated. The proximate analysis revealed the following composition: moisture 10.57 and 10%, ash 4.43 and 6.43%, fat 47.28 and 2.14%, crude protein 20.37 and 61.71%, carbohydrates 8.64 and 12.10% and crude fiber 8.70 and 7.37% for Gingerbread Plum Seed Flour (GPSF and Defatted Gingerbread Plum Seed Flour (DGPSF respectively. Oleic, linoleic and arachidonic acids were the major unsaturated fatty acids with 47.15, 19.10 and 17.64% respectively. Saturated fatty acids accounted for 14.72% of total fatty acids. The main saturated fatty acids were palmitic and stearic, with minute amounts of arachidic. Magnesium, potassium and calcium were the predominant elements present in the seeds. Copper, iron and manganese were also detected in appreciable amounts. Essential amino acids were above the recommended amount by Food Agricultural Organization/W orld Health Organization (FAO/WHO for humans. The results of the present investigation showed that gingerbread plum seeds are a rich source of many important nutrients that appear to have a very positive effect on human health.

  15. Chemical Analysis of Asymptotic Giant Branch Stars in M62

    Science.gov (United States)

    Lapenna, E.; Mucciarelli, A.; Ferraro, F. R.; Origlia, L.; Lanzoni, B.; Massari, D.; Dalessandro, E.

    2015-11-01

    We have collected UVES-FLAMES high-resolution spectra for a sample of 6 asymptotic giant branch (AGB) and 13 red giant branch (RGB) stars in the Galactic globular cluster (GC) M62 (NGC 6266). Here we present the detailed abundance analysis of iron, titanium, and light elements (O, Na, Mg, and Al). For the majority (five out of six) of the AGB targets, we find that the abundances of both iron and titanium determined from neutral lines are significantly underestimated with respect to those obtained from ionized features, the latter being, instead, in agreement with those measured for the RGB targets. This is similar to recent findings in other clusters and may suggest the presence of nonlocal thermodynamic equilibrium (NLTE) effects. In the O-Na, Al-Mg, and Na-Al planes, the RGB stars show the typical correlations observed for GC stars. Instead, all the AGB targets are clumped in the regions where first-generation stars are expected to lie, similar to what was recently found for the AGB population of NGC 6752. While the sodium and aluminum abundances could be underestimated as a consequence of the NLTE bias affecting iron and titanium, the oxygen line used does not suffer from the same effects, and the lack of O-poor AGB stars therefore is a solid result. We can thus conclude that none of the investigated AGB stars belongs to the second stellar generation of M62. We also find an RGB star with extremely high sodium abundance ([Na/Fe] = +1.08 dex). Based on observations collected at the ESO-VLT (Cerro Paranal, Chile) under program 193.D-0232. Also based on observations (GO10120 and GO11609) with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

  16. Multivariate data analysis for depth resolved chemical classification and quantification of sulfur in SNMS

    Science.gov (United States)

    Sommer, M.; Goschnick, J.

    2005-09-01

    The quantification of elements in quadrupole based SNMS is hampered by superpositions of atomic and cluster signals. Moreover, the conventional SNMS data evaluation employs only atomic signals to determine elemental concentrations, which not allows any chemical specifications of the determined elements. Improvements in the elemental quantification and additional chemical information can be obtained from kinetic energy analysis and the inclusion of molecular signals into mass spectra evaluation. With the help of multivariate data analysis techniques, the combined information is used for the first time for a quantitative and chemically distinctive determination of sulfur. The kinetic energy analysis, used to solve the interference of sulfur with O 2 at masses 32-34 D, turned out to be highly important for the new type of evaluation.

  17. Surface characterization and chemical analysis of bamboo substrates pretreated by alkali hydrogen peroxide.

    Science.gov (United States)

    Song, Xueping; Jiang, Yan; Rong, Xianjian; Wei, Wei; Wang, Shuangfei; Nie, Shuangxi

    2016-09-01

    The surface characterization and chemical analysis of bamboo substrates by alkali hydrogen peroxide pretreatment (AHPP) were investigated in this study. The results tended to manifest that AHPP prior to enzymatic and chemical treatment was potential for improving accessibility and reactivity of bamboo substrates. The inorganic components, organic solvent extractives and acid-soluble lignin were effectively removed by AHPP. X-ray photoelectron spectroscopy (XPS) analysis indicated that the surface of bamboo chips had less lignin but more carbohydrate after pre-treatment. Fiber surfaces became etched and collapsed, and more pores and debris on the substrate surface were observed with Scanning Electron Microscopy (SEM). Brenauer-Emmett-Teller (BET) results showed that both of pore volume and surface area were increased after AHPP. Although XRD analysis showed that AHPP led to relatively higher crystallinity, pre-extraction could overall enhance the accessibility of enzymes and chemicals into the bamboo structure. PMID:27311789

  18. Pretreatment and integrated analysis of spectral data reveal seaweed similarities based on chemical diversity.

    Science.gov (United States)

    Wei, Feifei; Ito, Kengo; Sakata, Kenji; Date, Yasuhiro; Kikuchi, Jun

    2015-03-01

    Extracting useful information from high dimensionality and large data sets is a major challenge for data-driven approaches. The present study was aimed at developing novel integrated analytical strategies for comprehensively characterizing seaweed similarities based on chemical diversity. The chemical compositions of 107 seaweed and 2 seagrass samples were analyzed using multiple techniques, including Fourier transform infrared (FT-IR) and solid- and solution-state nuclear magnetic resonance (NMR) spectroscopy, thermogravimetry-differential thermal analysis (TG-DTA), inductively coupled plasma-optical emission spectrometry (ICP-OES), CHNS/O total elemental analysis, and isotope ratio mass spectrometry (IR-MS). The spectral data were preprocessed using non-negative matrix factorization (NMF) and NMF combined with multivariate curve resolution-alternating least-squares (MCR-ALS) methods in order to separate individual component information from the overlapping and/or broad spectral peaks. Integrated analysis of the preprocessed chemical data demonstrated distinct discrimination of differential seaweed species. Further network analysis revealed a close correlation between the heavy metal elements and characteristic components of brown algae, such as cellulose, alginic acid, and sulfated mucopolysaccharides, providing a componential basis for its metal-sorbing potential. These results suggest that this integrated analytical strategy is useful for extracting and identifying the chemical characteristics of diverse seaweeds based on large chemical data sets, particularly complicated overlapping spectral data. PMID:25647718

  19. Size distribution measurements and chemical analysis of aerosol components

    Energy Technology Data Exchange (ETDEWEB)

    Pakkanen, T.A.

    1995-12-31

    The principal aims of this work were to improve the existing methods for size distribution measurements and to draw conclusions about atmospheric and in-stack aerosol chemistry and physics by utilizing size distributions of various aerosol components measured. A sample dissolution with dilute nitric acid in an ultrasonic bath and subsequent graphite furnace atomic absorption spectrometric analysis was found to result in low blank values and good recoveries for several elements in atmospheric fine particle size fractions below 2 {mu}m of equivalent aerodynamic particle diameter (EAD). Furthermore, it turned out that a substantial amount of analyses associated with insoluble material could be recovered since suspensions were formed. The size distribution measurements of in-stack combustion aerosols indicated two modal size distributions for most components measured. The existence of the fine particle mode suggests that a substantial fraction of such elements with two modal size distributions may vaporize and nucleate during the combustion process. In southern Norway, size distributions of atmospheric aerosol components usually exhibited one or two fine particle modes and one or two coarse particle modes. Atmospheric relative humidity values higher than 80% resulted in significant increase of the mass median diameters of the droplet mode. Important local and/or regional sources of As, Br, I, K, Mn, Pb, Sb, Si and Zn were found to exist in southern Norway. The existence of these sources was reflected in the corresponding size distributions determined, and was utilized in the development of a source identification method based on size distribution data. On the Finnish south coast, atmospheric coarse particle nitrate was found to be formed mostly through an atmospheric reaction of nitric acid with existing coarse particle sea salt but reactions and/or adsorption of nitric acid with soil derived particles also occurred. Chloride was depleted when acidic species reacted

  20. The SFM/ToF-SIMS combination for advanced chemically-resolved analysis at the nanoscale

    International Nuclear Information System (INIS)

    The combination of Time-of-flight Secondary Ion Mass Spectrometry (ToF-SIMS) and Scanning Force Microscopy (SFM) allows the 3D-compositional analysis of samples or devices. Typically, the topographical data obtained by SFM is used to determine the initial sample topography and the absolute depth of the ToF-SIMS analysis. Here ToF-SIMS and SFM data sets obtained on 2 prototypical samples are explored to go beyond conventional 3D-compositional analysis. SFM topographical and material contrast maps are combined with ToF-SIMS retrospective analysis to detect features that would have escaped a conventional ToF-SIMS data analysis. In addition, SFM data is used to extrapolate the chemical information beyond the spatial resolution of ToF-SIMS, allowing the mapping of the chemical composition at the nanoscale

  1. 3D thermo-chemical-mechanical analysis of the pultrusion process

    DEFF Research Database (Denmark)

    Baran, Ismet; Hattel, Jesper Henri; Tutum, Cem C.

    2013-01-01

    In the present study, a 3D Eulerian thermo-chemical analysis is sequentially coupled with a 3D Lagrangian quasi static mechanical analysis of the pultrusion process. The temperature and degree of cure profiles at the steady state are first calculated in the thermo-chemical analysis. In the...... mechanical analysis, the developments of the process induced stresses and distortions during the process are predicted using the already obtained temperature and degree of cure profiles together with the glass transition temperature. The predictions of the transverse transient stresses and distortions are...... found to be similar as compared to the available data in the literature. Using the proposed 3D mechanical analysis, different mechanical behaviour is obtained for the longitudinal stress development as distinct from the stress development in the transverse directions. Even though the matrix material is...

  2. Participation in the 1999 IAEA interlaboratory comparison on chemical analysis of groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Joe, Kih Soo; Choi, Kwang Soon; Han, Sun Ho; Suh, Moo Yul; Park, Kyung Kyun; Choi, Ke Chun; Kim, Won Ho

    2000-08-01

    KAERI analytical laboratory participated in the 1999 IAEA interlaboratory comparison on chemical analysis of groundwater organized by IAEA Hydrology Laboratory(RAS/8/084). 13 items such as pH, electroconductivity, HCO{sub 3}, Cl, SO{sub 4}, NO{sub 3}, SiO{sub 2}, B, Li, Na, K, Ca, Mg were analyzed. The result of this program showed that KAERI laboratory was ranked within 10% range from top level. An analytical expert in KAERI attended the 'Consultants' Meeting' at IAEA headquater and prepared the guideline for chemical analysis of groundwater.

  3. Study on the chemical species of platinum group elements in geological samples by molecular activation analysis

    International Nuclear Information System (INIS)

    The chemical species of platinum group elements in some upper mantle-derived xenoliths from Eastern China are studied by molecular activation analysis, in which the chemical stepwise dissolution, nickel fire assay preconcentration and neutron activation analysis are jointly applied. The weighted sums of platinum group elements in 6 phases are in agreement with their total contents. The distribution patterns of platinum group elements in sulphides show that sulphide segregation is one of the important mechanisms for the fractionation of platinum group elements in upper mantle-derived material during partial melting

  4. Scanning angle Raman spectroscopy: Investigation of Raman scatter enhancement techniques for chemical analysis

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Matthew W. [Iowa State Univ., Ames, IA (United States)

    2013-01-01

    This thesis outlines advancements in Raman scatter enhancement techniques by applying evanescent fields, standing-waves (waveguides) and surface enhancements to increase the generated mean square electric field, which is directly related to the intensity of Raman scattering. These techniques are accomplished by employing scanning angle Raman spectroscopy and surface enhanced Raman spectroscopy. A 1064 nm multichannel Raman spectrometer is discussed for chemical analysis of lignin. Extending dispersive multichannel Raman spectroscopy to 1064 nm reduces the fluorescence interference that can mask the weaker Raman scattering. Overall, these techniques help address the major obstacles in Raman spectroscopy for chemical analysis, which include the inherently weak Raman cross section and susceptibility to fluorescence interference.

  5. Participation in the 1999 IAEA interlaboratory comparison on chemical analysis of groundwater

    International Nuclear Information System (INIS)

    KAERI analytical laboratory participated in the 1999 IAEA interlaboratory comparison on chemical analysis of groundwater organized by IAEA Hydrology Laboratory(RAS/8/084). 13 items such as pH, electroconductivity, HCO3, Cl, SO4, NO3, SiO2, B, Li, Na, K, Ca, Mg were analyzed. The result of this program showed that KAERI laboratory was ranked within 10% range from top level. An analytical expert in KAERI attended the 'Consultants' Meeting' at IAEA headquater and prepared the guideline for chemical analysis of groundwater

  6. Application of physico-chemical procedures in the analysis of urinary calculi

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, A.L.

    1985-01-01

    All physico-chemical techniques used in the analysis of urinary calculi have inherent advantages and limitations. Although x-ray powder diffraction can identify constituents unambiguously, certain minor components can be missed. Infrared spectroscopy is more sensitive but band assignment at low concentrations is difficult. Scanning electron microscopy together with energy dispersive x-ray analysis permits the simultaneous investigation of morphology and chemical microstructure. With the electron microprobe, minor constituents can be detected but tedious sample preparation procedures are required. Transmission electron microscopy is extremely useful in determining constituent inter-relationships and ultrastructure but ultramicrotomy is very difficult. Thermal gravimetric analysis gives quantitative information easily but does not satisfactorily distinguish between struvite and brushite. In an attempt to assess the accuracy of chemical analyses, 62 calculi were investigated applying several chemical tests. Those for MgS , PO4(T ), NHU and uric acid proved highly reliable while that for CaS often yielded an incorrect result. The test for oxalate was totally unsatisfactory. Investigators of stone composition and structure should include x-ray diffraction (or infrared spectroscopy) and scanning electron microscopy as their methods of first choice. In addition, chemical or thermogravimetric analyses should be utilized in an auxiliary capacity.

  7. Forecasting global developments in the basic chemical industry for environmental policy analysis

    International Nuclear Information System (INIS)

    The chemical sector is the largest industrial energy user, but detailed analysis of its energy use developments lags behind other energy-intensive sectors. A cost-driven forecasting model for basic chemicals production is developed, accounting for regional production costs, demand growth and stock turnover. The model determines the global production capacity placement, implementation of energy-efficient Best Practice Technology (BPT) and global carbon dioxide (CO2) emissions for the period 2010–2030. Subsequently, the effects of energy and climate policies on these parameters are quantified. About 60% of new basic chemical production capacity is projected to be placed in non-OECD regions by 2030 due to low energy prices. While global production increases by 80% between 2010 and 2030, the OECD's production capacity share decreases from 40% to 20% and global emissions increase by 50%. Energy pricing and climate policies are found to reduce 2030 CO2 emissions by 5–15% relative to the baseline developments by increasing BPT implementation. Maximum BPT implementation results in a 25% reduction. Further emission reductions require measures beyond energy-efficient technologies. The model is useful to estimate general trends related to basic chemicals production, but improved data from the chemical sector is required to expand the analysis to additional technologies and chemicals. - Highlights: • We develop a global cost-driven forecasting model for the basic chemical sector. • We study regional production, energy-efficient technology, emissions and policies. • Between 2010 and 2030, 60% of new chemicals capacity is built in non-OECD regions. • Global CO2 emissions rise by 50%, but climate policies may limit this to 30–40%. • Measures beyond energy efficiency are needed to prevent increasing CO2 emissions

  8. Chemical Analysis of Exhaled Human Breath Using High Resolution Mm-Wave Rotational Spectra

    Science.gov (United States)

    Guo, Tianle; Branco, Daniela; Thomas, Jessica; Medvedev, Ivan; Dolson, David; Nam, Hyun-Joo; O, Kenneth

    2014-06-01

    High resolution rotational spectroscopy enables chemical sensors that are both sensitive and highly specific, which is well suited for analysis of expired human breath. We have previously reported on detection of breath ethanol, methanol, acetone, and acetaldehyde using THz sensors. This paper will outline our present efforts in this area, with specific focus on our ongoing quest to correlate levels of blood glucose with concentrations of a few breath chemicals known to be affected by elevated blood sugar levels. Prospects, challenges and future plans will be outlined and discussed. Fosnight, A.M., B.L. Moran, and I.R. Medvedev, Chemical analysis of exhaled human breath using a terahertz spectroscopic approach. Applied Physics Letters, 2013. 103(13): p. 133703-5.

  9. SWOT analysis for safer carriage of bulk liquid chemicals in tankers.

    Science.gov (United States)

    Arslan, Ozcan; Er, Ismail Deha

    2008-06-15

    The application of strengths, weaknesses, opportunities and threats (SWOT) analysis to formulation of strategy concerned with the safe carriage of bulk liquid chemicals in maritime tankers was examined in this study. A qualitative investigation using SWOT analysis has been implemented successfully for ships that are designed to carry liquid chemicals in bulk. The originality of this study lies in the use of SWOT analysis as a management tool to formulate strategic action plans for ship management companies, ship masters and officers for the carriage of dangerous goods in bulk. With this transportation-based SWOT analysis, efforts were made to explore the ways and means of converting possible threats into opportunities, and changing weaknesses into strengths; and strategic plans of action were developed for safer tanker operation. PMID:18093731

  10. Recent Development in Optical Chemical Sensors Coupling with Flow Injection Analysis

    Directory of Open Access Journals (Sweden)

    Fuensanta Sánchez Rojas

    2006-10-01

    Full Text Available Optical techniques for chemical analysis are well established and sensors based on thesetechniques are now attracting considerable attention because of their importance in applications suchas environmental monitoring, biomedical sensing, and industrial process control. On the other hand,flow injection analysis (FIA is advisable for the rapid analysis of microliter volume samples and canbe interfaced directly to the chemical process. The FIA has become a widespread automatic analyticalmethod for more reasons; mainly due to the simplicity and low cost of the setups, their versatility, andease of assembling. In this paper, an overview of flow injection determinations by using opticalchemical sensors is provided, and instrumentation, sensor design, and applications are discussed. Thiswork summarizes the most relevant manuscripts from 1980 to date referred to analysis using opticalchemical sensors in FIA.

  11. LANL organic analysis detection capabilities for chemical and biological warfare agents

    Energy Technology Data Exchange (ETDEWEB)

    Ansell, G.B.; Cournoyer, M.E.; Hollis, K.W.; Monagle, M.

    1996-12-31

    Organic analysis is the analytical arm for several Los Alamos National Laboratory (LANL) research programs and nuclear materials processes, including characterization and certification of nuclear and nonnuclear materials used in weapons, radioactive waste treatment and waste certification programs. Organic Analysis has an extensive repertoire of analytical technique within the group including headspace gas, PCBs/pesticides, volatile organics and semivolatile organic analysis. In addition organic analysis has mobile labs with analytic capabilities that include volatile organics, total petroleum hydrocarbon, PCBs, pesticides, polyaromatic hydrocarbons and high explosive screening. A natural extension of these capabilities can be applied to the detection of chemical and biological agents,

  12. Supramolecular chemical shift reagents inducing conformational transitions: NMR analysis of carbohydrate homooligomer mixtures

    DEFF Research Database (Denmark)

    Beeren, Sophie; Meier, Sebastian

    2015-01-01

    We introduce the concept of supramolecular chemical shift reagents as a tool to improve signal resolution for the NMR analysis of homooligomers. Non-covalent interactions with the shift reagent can constrain otherwise flexible analytes inducing a conformational transition that results in signal...

  13. Fertilizer/Chemical Sales and Service Worker. Ohio's Competency Analysis Profile.

    Science.gov (United States)

    Ohio State Univ., Columbus. Vocational Instructional Materials Lab.

    This Ohio Competency Analysis Profile (OCAP), derived from a modified Developing a Curriculum (DACUM) process, is a current comprehensive and verified employer competency program list for fertilizer/chemical sales and service workers. Each unit (with or without subunits) contains competencies and competency builders that identify the occupational,…

  14. Quantitative analysis of chemical elements in single cells using nuclear microprobe and nano-probe

    International Nuclear Information System (INIS)

    The study of the role of trace elements at cellular level requires the use of state-of-the-art analytical tools that could achieve enough sensitivity and spatial resolution. We developed a new methodology for the accurate quantification of chemical element distribution in single cells based on a combination of ion beam analysis techniques STIM, PIXE and RBS. The quantification procedure relies on the development of a STIM data analysis software (Paparamborde). Validity of this methodology and limits are discussed here. The method allows the quantification of trace elements (μg/g) with a 19.8 % uncertainty in cellular compartments with mass below 0.1 ng. The main limit of the method lies in the poor number of samples that can be analyzed, due to long irradiation times required and limited access to ion beam analysis facilities. This is the reason why we developed a database for cellular chemical composition capitalization (BDC4). BDC4 has been designed in order to use cellular chemical composition as a tracer for biological activities and is expected to provide in the future reference chemical compositions for any cellular type or compartment. Application of the STIM-PIXE-RBS methodology to the study of nuclear toxicology of cobalt compounds is presented here showing that STIM analysis is absolutely needed when organic mass loss appears during PIXE-RBS irradiation. (author)

  15. On the graph and systems analysis of reversible chemical reaction networks with mass action kinetics

    NARCIS (Netherlands)

    Rao, Shodhan; Jayawardhana, Bayu; Schaft, Arjan van der

    2012-01-01

    Motivated by the recent progresses on the interplay between the graph theory and systems theory, we revisit the analysis of reversible chemical reaction networks described by mass action kinetics by reformulating it using the graph knowledge of the underlying networks. Based on this formulation, we

  16. Chemical analysis and quality control of Ginkgo biloba leaves, extracts, and phytopharmaceuticals

    NARCIS (Netherlands)

    Beek, van T.A.; Montoro, P.

    2009-01-01

    The chemical analysis and quality control of Ginkgo leaves, extracts, phytopharmaceuticals and some herbal supplements is comprehensively reviewed. The review is an update of a similar, earlier review in this journal [T.A. van Beek, J. Chromatogr. A 967 (2002) 21¿55]. Since 2001 over 3000 papers on

  17. A methodology for chemical hazards analysis at nuclear fuels reprocessing plants

    International Nuclear Information System (INIS)

    The Savannah River Laboratory employs a formal methodology for chemical hazards analysis primarily for use in the risk assessment of its nuclear fuels reprocessing plants. The methodology combines interactive matrices for reactions of available materials, fault tree analysis, human factors, and extensive data banks on the operating history of the plants. Examples illustrate the methodology and a related data bank. 5 refs., 2 figs., 4 tabs

  18. PHYSICO-CHEMICAL ANALYSIS OF FRESH AND FERMENTED FRUIT JUICES PROBIOTICATED WITH LACTOBACILLUS CASEI

    OpenAIRE

    Bathal Vijaya Kumar; Mannepula Sreedharamurthy; Obulam Vijaya Sarathi Reddy

    2013-01-01

    The objective of this study was to find out the suitability of different fruit juices for probiotication by using Lactobacillus casei. Phyto-chemical analysis of different fruit juices (mango, sapota, grape and cantaloupe) were carried out using the standard methods. Carbohydrates, flavoniods, tannins, glycosides were present and alkaloids and saponins were absent in all the above fruit juices. Further analysis by TLC and DPPH methods indicated good antioxidant activity in all the fruit juice...

  19. Prediction of chemical, physical and sensory data from process parameters for frozen cod using multivariate analysis

    DEFF Research Database (Denmark)

    Bechmann, Iben Ellegaard; Jensen, H.S.; Bøknæs, Niels;

    1998-01-01

    varied systematically at two levels. The data obtained were evaluated using the multivariate methods, principal component analysis (PCA) and partial least squares (PLS) regression. The PCA models were used to identify which process parameters were actually most important for the quality of the frozen cod...... by ones and zeroes only. These results illustrate the application of multivariate analysis as an effective strategy for improving the quality of frozen fish products. (C) 1998 Society of Chemical Industry...

  20. On the graph and systems analysis of reversible chemical reaction networks with mass action kinetics

    OpenAIRE

    Rao, Shodhan; Jayawardhana, Bayu; der Schaft, Arjan van

    2012-01-01

    Motivated by the recent progresses on the interplay between the graph theory and systems theory, we revisit the analysis of reversible chemical reaction networks described by mass action kinetics by reformulating it using the graph knowledge of the underlying networks. Based on this formulation, we can characterize the space of equilibrium points and provide simple dynamical analysis on the state space modulo the space of equilibrium points.

  1. Chemical analysis of bleach and hydroxide-based solutions after decontamination of the chemical warfare agent O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX).

    Science.gov (United States)

    Hopkins, F B; Gravett, M R; Self, A J; Wang, M; Chua, Hoe-Chee; Hoe-Chee, C; Lee, H S Nancy; Sim, N Lee Hoi; Jones, J T A; Timperley, C M; Riches, J R

    2014-08-01

    Detailed chemical analysis of solutions used to decontaminate chemical warfare agents can be used to support verification and forensic attribution. Decontamination solutions are amongst the most difficult matrices for chemical analysis because of their corrosive and potentially emulsion-based nature. Consequently, there are relatively few publications that report their detailed chemical analysis. This paper describes the application of modern analytical techniques to the analysis of decontamination solutions following decontamination of the chemical warfare agent O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX). We confirm the formation of N,N-diisopropylformamide and N,N-diisopropylamine following decontamination of VX with hypochlorite-based solution, whereas they were not detected in extracts of hydroxide-based decontamination solutions by nuclear magnetic resonance (NMR) spectroscopy or gas chromatography-mass spectrometry. We report the electron ionisation and chemical ionisation mass spectroscopic details, retention indices, and NMR spectra of N,N-diisopropylformamide and N,N-diisopropylamine, as well as analytical methods suitable for their analysis and identification in solvent extracts and decontamination residues. PMID:24633585

  2. Application of hazard analysis critical control points (HACCP) to organic chemical contaminants in food.

    Science.gov (United States)

    Ropkins, K; Beck, A J

    2002-03-01

    Hazard Analysis Critical Control Points (HACCP) is a systematic approach to the identification, assessment, and control of hazards that was developed as an effective alternative to conventional end-point analysis to control food safety. It has been described as the most effective means of controlling foodborne diseases, and its application to the control of microbiological hazards has been accepted internationally. By contrast, relatively little has been reported relating to the potential use of HACCP, or HACCP-like procedures, to control chemical contaminants of food. This article presents an overview of the implementation of HACCP and discusses its application to the control of organic chemical contaminants in the food chain. Although this is likely to result in many of the advantages previously identified for microbiological HACCP, that is, more effective, efficient, and economical hazard management, a number of areas are identified that require further research and development. These include: (1) a need to refine the methods of chemical contaminant identification and risk assessment employed, (2) develop more cost-effective monitoring and control methods for routine chemical contaminant surveillance of food, and (3) improve the effectiveness of process optimization for the control of chemical contaminants in food. PMID:11934130

  3. ANALYSIS OF CHEMICAL COMPOUNDS OF AGARWOOD OIL FROM DIFFERENT SPECIES BY GAS CHROMATOGRAPHY MASS SPECTROMETRY (GCMS)

    OpenAIRE

    Yumi Zuhanis Has-Yun Hashim; Nur Izzah Ismail; Phirdaous Abbas

    2014-01-01

    ABSTRACT: Agarwood oil is a highly prized type of oil due to its unique aroma. The oil is extracted from the fragrant resin found in the agarwood tree (trunk).  The unique aroma and quality of agarwood resin and oil are contributed by the presence of certain chemical compounds. In this work, analysis and comparison of the chemical compounds of agarwood oil from A. malaccensis, A. sub-integra and a mixture of both were conducted.  The essential oils were diluted in hexane (5%) prior to gas chr...

  4. Extracting chemical information from plane wave calculations by a 3D 'fuzzy atoms' analysis

    Science.gov (United States)

    Bakó, I.; Stirling, A.; Seitsonen, A. P.; Mayer, I.

    2013-03-01

    Bond order and valence indices have been calculated by the method of the three-dimensional 'fuzzy atoms' analysis, using the numerical molecular orbitals obtained from plane wave DFT calculations, i.e., without introducing any external atom-centered functions. Weight functions of both Hirshfeld and Becke types have been applied. The results are rather close to the similar 'fuzzy atoms' ones obtained by using atom-centered basis sets and agree well with the chemical expectations, stressing the power of the genuine chemical concepts.

  5. Impact analysis of different chemical pre-treatments on colour of apple discs during drying process

    OpenAIRE

    Magdić, D.; Lukinac, Jasmina; Jokić, Stela; Čačić-Kenjerić, F.; Bilić, M.; Velić, D.

    2009-01-01

    The main purpose of this study was to compare colour changes of chemically pre-treated dried apple discs. Changes were observed by chromameter in L*a*b* colour model by using Minolta chromameter CR-400 and by image analysis system in RGB colour model. Apple discs variety "Gold Rush" were pre-treated and dried in laboratory tray drier at drying temperature 70 °C and at airflow velocity of 1.5 ms-1. Different chemical pre-treatments were applied on apple discs (dipping in 0.5% ascorbic acid sol...

  6. Sampling and chemical analysis in environmental samples around Nuclear Power Plants and some environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yong Woo; Han, Man Jung; Cho, Seong Won; Cho, Hong Jun; Oh, Hyeon Kyun; Lee, Jeong Min; Chang, Jae Sook [KORTIC, Taejon (Korea, Republic of)

    2002-12-15

    Twelve kinds of environmental samples such as soil, seawater, underground water, etc. around Nuclear Power Plants(NPPs) were collected. Tritium chemical analysis was tried for the samples of rain water, pine-needle, air, seawater, underground water, chinese cabbage, a grain of rice and milk sampled around NPPs, and surface seawater and rain water sampled over the country. Strontium in the soil that sere sampled at 60 point of district in Korea were analyzed. Tritium were sampled at 60 point of district in Korea were analyzed. Tritium were analyzed in 21 samples of surface seawater around the Korea peninsular that were supplied from KFRDI(National Fisheries Research and Development Institute). Sampling and chemical analysis environmental samples around Kori, Woolsung, Youngkwang, Wooljin Npps and Taeduk science town for tritium and strontium analysis was managed according to plans. Succeed to KINS after all samples were tried.

  7. Humidity independent mass spectrometry for gas phase chemical analysis via ambient proton transfer reaction

    International Nuclear Information System (INIS)

    Graphical abstract: Direct and humidity independent mass spectrometry analysis of gas phase chemicals could be achieved via ambient proton transfer ionization, ion intensity was found to be stable with humidity ranged from ∼10% to ∼100%. - Highlights: • A humidity independent mass spectrometric method for gas phase samples analysis. • A universal and good sensitivity method. • The method can real time identify plant released raw chemicals. - Abstract: In this work, a humidity independent mass spectrometric method was developed for rapid analysis of gas phase chemicals. This method is based upon ambient proton transfer reaction between gas phase chemicals and charged water droplets, in a reaction chamber with nearly saturate humidity under atmospheric pressure. The humidity independent nature enables direct and rapid analysis of raw gas phase samples, avoiding time- and sample-consuming sample pretreatments in conventional mass spectrometry methods to control sample humidity. Acetone, benzene, toluene, ethylbenzene and meta-xylene were used to evaluate the analytical performance of present method. The limits of detection for benzene, toluene, ethylbenzene and meta-xylene are in the range of ∼0.1 to ∼0.3 ppbV; that of benzene is well below the present European Union permissible exposure limit for benzene vapor (5 μg m−3, ∼1.44 ppbV), with linear ranges of approximately two orders of magnitude. The majority of the homemade device contains a stainless steel tube as reaction chamber and an ultrasonic humidifier as the source of charged water droplets, which makes this cheap device easy to assemble and facile to operate. In addition, potential application of this method was illustrated by the real time identification of raw gas phase chemicals released from plants at different physiological stages

  8. Observations on the morphology and chemical analysis of medullary granules in chinchilla hair. Research letters

    Energy Technology Data Exchange (ETDEWEB)

    Keogh, H.J. (South African Inst. for Medical Research, Johannesburg); Haylett, T. (Council for Scientific and Industrial Research, Pretoria (South Africa). National Chemical Research Lab.)

    1983-02-01

    The ultrastructure of the medullary granules of white and grey chinchilla hair was investigated by scanning electron microscopy and chemical analysis in an attempt to clarify their structure and function. Atomic absorption spectroscopy and amino acid analysis showed them to be composed of melanin. The sample preparation for scanning electron microscopy is discussed. The metal content was qualitatively established by X-ray fluorescence spectrometry and quantitatively determined on a Varian Techtron model AAs atomic absorption spectrophotometer. Amino acid analysis of the granule, was carried out on a Beckman 121 amino acid analyser. Information is provided on the amino acid composition of the medullary granules as well as its metal content.

  9. Observations on the morphology and chemical analysis of medullary granules in chinchilla hair

    International Nuclear Information System (INIS)

    The ultrastructure of the medullary granules of white and grey chinchilla hair was investigated by scanning electron microscopy and chemical analysis in an attempt to clarify their structure and function. Atomic absorption spectroscopy and amino acid analysis showed them to be composed of melanin. The sample preparation for scanning electron microscopy is discussed. The metal content was qualitatively established by X-ray fluorescence spectrometry and quantitatively determined on a Varian Techtron model AAs atomic absorption spectrophotometer. Amino acid analysis of the granule, was carried out on a Beckman 121 amino acid analyser. Information is provided on the amino acid composition of the medullary granules as well as its metal content

  10. LSENS, a general chemical kinetics and sensitivity analysis code for gas-phase reactions: User's guide

    Science.gov (United States)

    Radhakrishnan, Krishnan; Bittker, David A.

    1993-01-01

    A general chemical kinetics and sensitivity analysis code for complex, homogeneous, gas-phase reactions is described. The main features of the code, LSENS, are its flexibility, efficiency and convenience in treating many different chemical reaction models. The models include static system, steady, one-dimensional, inviscid flow, shock initiated reaction, and a perfectly stirred reactor. In addition, equilibrium computations can be performed for several assigned states. An implicit numerical integration method, which works efficiently for the extremes of very fast and very slow reaction, is used for solving the 'stiff' differential equation systems that arise in chemical kinetics. For static reactions, sensitivity coefficients of all dependent variables and their temporal derivatives with respect to the initial values of dependent variables and/or the rate coefficient parameters can be computed. This paper presents descriptions of the code and its usage, and includes several illustrative example problems.

  11. Physico Chemical Analysis of Sapota (Manilkara zapota Coated by Edible Aloe Vera Gel

    Directory of Open Access Journals (Sweden)

    N. Padmaja

    2015-03-01

    Full Text Available The physical and chemical characteristics of the fruit have immense significance as they ultimately affect the quality of processed productsprepared from them. Over ripening of Sapota (Manilkara zapota fruits at the post-harvest stage usually results in dramatic decline in quality.In the present study, physico chemical analysis (which includes Weight loss, Colour, Texture, TSS, pH, TA and Ascorbic acid content ofedible Aloe vera gel coated Sapota fruits packed in LDPE and stored at 15 ± 2? were studied at regular intervals of 5 days i.e., 0th,5th, 10th,15thand 20th days. The dip treatment of Aloe vera gel coating 1:2, 7 minutes had best retained the physico chemical characteristics than the othertreatments performed and was found to be the most effective treatment in maintaining the fruit quality attributes along with the shelf lifeextension of about 20 days.

  12. Low Cost Long Distance Detector for Explosives and Chemical Analysis by IEC Application

    Directory of Open Access Journals (Sweden)

    George H. Miley

    2005-01-01

    Full Text Available A radiation source for detecting specific chemicals at several meter distances even behind walls, car doors or other barriers is the application of Million electron Volts (MeV neutrons from nuclear fusion reactions at such low intensities to avoid any danger for human bodies. The chemical analysis consists in the neutron activation of nuclei emitting then gamma radiation of lines very specific for the excited nuclei. The neutron generation by the Inertial Electrostatic Confinement (IEC had been developed to a level where very low cost neutron generators in mass production may be developed with a power supply from a normal AC plug-in or a battery. For specific chemicals e.g. the ratio of nitrogen against other elements used in all explosives, the selection of few specific gamma lines for the detectors may be of sufficiently low cost in the case of mass production.

  13. Development and Analysis of Group Contribution Plus Models for Property Prediction of Organic Chemical Systems

    DEFF Research Database (Denmark)

    Mustaffa, Azizul Azri

    and further development of the GCPlus approach for predicting mixture properties to be called the UNIFAC-CI model. The contributions of this work include an analysis of the developed Original UNIFAC-CI model in order to investigate why the model does not perform as well as the reference UNIFAC model......Prediction of properties is important in chemical process-product design. Reliable property models are needed for increasingly complex and wider range of chemicals. Group-contribution methods provide useful tool but there is a need to validate them and improve their accuracy when complex chemicals...... are present in the mixtures. In accordance with that, a combined group-contribution and atom connectivity approach that is able to extend the application range of property models has been developed for mixture properties. This so-called Group-ContributionPlus (GCPlus) approach is a hybrid model which...

  14. Combined Micro-chemical and Micro-structural Analysis of New Minerals Representing Extreme Conditions

    Science.gov (United States)

    Ma, C.; Tschauner, O. D.

    2015-12-01

    Recent improvements in micro-chemical analysis in combination with novel tools for micrometer-scale structural analysis of minerals from synchrotron X-ray diffraction open a pathway towards studies of mineral paragenesis that were previously not or barely accessible. Often mineral assemblies that represent extreme conditions also pose extreme challenges to analysis: very small size scale, complex matrix, minor amounts of material. Examples of such extreme, but also quite relevant environments are: a) High pressure shock-metamorphic minerals in meteorites and terrestrial impact sites, b) inclusions in diamonds from the deep mantle, c) ultrarefractory phases in Ca-Al-inlcusions from the solar nebula, d) presolar condensates. We show how a combination of synchrotron-based structural and semi-quantitative chemical techniques, with electron-microscopy based high-resolution imaging and fully quantitative chemical analysis and qualitative structural identification establish a powerful tool for discovery and characterization of important and interesting new minerals on micron- to submicron size scale.

  15. USE OF AMAZONIAN SPECIES FOR AGING DISTILLED BEVERAGES: PHYSICAL AND CHEMICAL WOOD ANALYSIS

    Directory of Open Access Journals (Sweden)

    Jonnys Paz Castro

    2015-06-01

    Full Text Available The process of storing liquor in wooden barrels is a practice that aims to improve the sensory characteristics, such as color, aroma and flavor, of the beverage. The quality of the liquor stored in these barrels depends on wood characteristics such as density, permeability, chemical composition, anatomy, besides the wood heat treatment used to fabricate the barrels. Brazil has a great diversity of forests, mainly in the north, in the Amazon. This region is home to thousands of tree species, but is limited to the use of only a few native species to store liquors. The objective of this study was to determine some of the physical and chemical characteristics for four Amazon wood species. The results obtained in this study will be compared with others from woods that are traditionally used for liquor storage. The species studied were angelim-pedra (Hymenolobium petraeum Ducke cumarurana (Dipteryx polyphylla (Huber Ducke, jatobá (Hymenaea courbaril L. and louro-vermelho (Nectandra rubra (Mez CK Allen. The trees were collected from Precious Woods Amazon Company forest management area, in Silves, Amazonas. Analyzes such as: concentration of extractives, lignin amount, percentage of minerals (ash and tannin content, density, elemental analysis (CHNS-O and thermal analysis were done. It was observed that the chemical composition (lignin, holocellulose and elemental analysis (percentage of C, H, N and O of the woods have significant differences. The jatobá wood presented higher tannin content, and in the thermal analysis, was that which had the lowest mass loss.

  16. Chemical and physical analysis of core materials for advanced high temperature reactors with process heat applications

    International Nuclear Information System (INIS)

    Various chemical and physical methods for the analysis of structural materials have been developed in the research programmes for advanced high temperature reactors. These methods are discussed using as examples the structural materials of the reactor core - the fuel elements consisting of coated particles in a graphite matrix and the structural graphite. Emphasis is given to the methods of chemical analysis. The composition of fuel kernels is investigated using chemical analysis methods to determine the heavy metals content (uranium, plutonium, thorium and metallic impurity elements) and the amount of non-metallic constituents. The properties of the pyrocarbon and silicon carbide coatings of fuel elements are investigated using specially developed physiochemical methods. Regarding the irradiation behaviour of coated particles and fuel elements, methods have been developed for examining specimens in hot cells following exposures under reactor operating conditions, to supplement the measurements of in-reactor performance. For the structural graphite, the determination of impurities is important because certain impurities may cause pitting corrosion during irradiation. The localized analysis of very low impurity concentrations is carried out using spectrochemical d.c. arc excitation, local laser and inductively coupled plasma methods. (orig.)

  17. Do provisions to advance chemical facility safety also advance chemical facility security? An analysis of possible synergies

    DEFF Research Database (Denmark)

    Hedlund, Frank Huess

    2012-01-01

    The European Commission has launched a study on the applicability of existing chemical industry safety provisions to enhancing security of chemical facilities covering the situation in 18 EU Member States. This paper reports some preliminary analytical findings regarding the extent to which...... Infrastructures (ECI Directive) addresses facility security but does not cover the chemical sector. Chemical facility safety at EU level is addressed by way of the Seveso-II Directive. Preliminary estimates by the chemical industry suggest that perhaps 80% of the existing safety measures under Seveso-II would...... existing provisions that have been put into existence to advance safety objectives due to synergy effects could be expected advance security objectives as well. The paper provides a conceptual definition of safety and security and presents a framework of their essential components. Key differences are...

  18. Analysis of changes in the chemical composition of the blast furnace coke at high temperatures

    Directory of Open Access Journals (Sweden)

    A. Konstanciak

    2012-12-01

    Full Text Available Purpose: The main purpose of this paper was to analyze the behavior of coke in the blast furnace. The analysis of changes in chemical composition of coke due to impact of inert gas and air at different temperatures was made. The impact of the application of the thermoabrasion coefficient on the porosity of coke was also analyzed.Design/methodology/approach: By applying the Computer Thermochemical Database of the TERMO system (REAKTOR1 and REAKTOR3 three groups of substances can be distinguished. The chemical composition of blast furnace coke and the results of calculations of changes of chemical composition of coke heat treated under certain conditions were compared. The structural studies of these materials were presented.Findings: The results of the analysis of ash produced from one of Polish cokes was taken for consideration. This is not the average composition of Polish coke ashes, nevertheless it is representative of most commonly occurring chemical compositions.Practical implications: Thanks to the thermochemical calculations it is possible to predict ash composition after the treatment in a blast furnace. Those information was crucial and had an actual impact on determining the coke quality.Originality/value: Presentation of the analytical methods which, according to author, can be very useful to evaluate and identify the heat treatment for blast furnaces cokes. The research pursued represents part of a larger project carried out within the framework of Department Extraction and Recycling of Metals, Czestochowa University of Technology.

  19. Phthalic Acid Chemical Probes Synthesized for Protein-Protein Interaction Analysis

    Directory of Open Access Journals (Sweden)

    Chin-Jen Wu

    2013-06-01

    Full Text Available Plasticizers are additives that are used to increase the flexibility of plastic during manufacturing. However, in injection molding processes, plasticizers cannot be generated with monomers because they can peel off from the plastics into the surrounding environment, water, or food, or become attached to skin. Among the various plasticizers that are used, 1,2-benzenedicarboxylic acid (phthalic acid is a typical precursor to generate phthalates. In addition, phthalic acid is a metabolite of diethylhexyl phthalate (DEHP. According to Gene_Ontology gene/protein database, phthalates can cause genital diseases, cardiotoxicity, hepatotoxicity, nephrotoxicity, etc. In this study, a silanized linker (3-aminopropyl triethoxyslane, APTES was deposited on silicon dioxides (SiO2 particles and phthalate chemical probes were manufactured from phthalic acid and APTES–SiO2. These probes could be used for detecting proteins that targeted phthalic acid and for protein-protein interactions. The phthalic acid chemical probes we produced were incubated with epithelioid cell lysates of normal rat kidney (NRK-52E cells to detect the interactions between phthalic acid and NRK-52E extracted proteins. These chemical probes interacted with a number of chaperones such as protein disulfide-isomerase A6, heat shock proteins, and Serpin H1. Ingenuity Pathways Analysis (IPA software showed that these chemical probes were a practical technique for protein-protein interaction analysis.

  20. Analysis of pharmaceutical pellets: An approach using near-infrared chemical imaging

    Energy Technology Data Exchange (ETDEWEB)

    Sabin, Guilherme P.; Breitkreitz, Marcia C.; Souza, Andre M. de [Institute of Chemistry, University of Campinas, P.O. Box 6154, 13084-971 Campinas, SP (Brazil); Fonseca, Patricia da; Calefe, Lupercio; Moffa, Mario [Zelus Servicos para Industria Farmaceutica Ltda., Av. Professor Lineu Prestes n. 2242, Sao Paulo, SP (Brazil); Poppi, Ronei J., E-mail: ronei@iqm.unicamp.br [Institute of Chemistry, University of Campinas, P.O. Box 6154, 13084-971 Campinas, SP (Brazil)

    2011-11-07

    Highlights: {yields} Near-Infrared Chemical Imaging was used for pellets analysis. {yields} Distribution of the components throughout the coatings layers and core of the pellets was estimated. {yields} Classical Least Squares (CLS) was used for calculation of the concentration maps. - Abstract: Pharmaceutical pellets are spherical or nearly spherical multi-unit dosage forms designed to optimize pharmacokinetics and pharmacodynamics features of drug release. The distribution of the pharmaceutical ingredients in the layers and core is a very important parameter for appropriate drug release, especially for pellets manufactured by the process of layer gain. Physical aspects of the sample are normally evaluated by Scanning Electron Microscopy (SEM), but it is in many cases unsuitable to provide conclusive chemical information about the distribution of the pharmaceutical ingredients in both layers and core. On the other hand, methods based on spectroscopic imaging can be very promising for this purpose. In this work, a Near-Infrared Chemical Imaging (NIR-CI) method was developed and applied to the analysis of diclophenac sodium pellets. Since all the compounds present in the sample were known in advance, Classical Least Squares (CLS) was used for calculations. The results have shown that the method was capable of providing chemical information about the distribution of the active ingredient and excipients in the core and coating layers and therefore can be complementary to SEM for the pharmaceutical development of pellets.

  1. Analysis of pharmaceutical pellets: An approach using near-infrared chemical imaging

    International Nuclear Information System (INIS)

    Highlights: → Near-Infrared Chemical Imaging was used for pellets analysis. → Distribution of the components throughout the coatings layers and core of the pellets was estimated. → Classical Least Squares (CLS) was used for calculation of the concentration maps. - Abstract: Pharmaceutical pellets are spherical or nearly spherical multi-unit dosage forms designed to optimize pharmacokinetics and pharmacodynamics features of drug release. The distribution of the pharmaceutical ingredients in the layers and core is a very important parameter for appropriate drug release, especially for pellets manufactured by the process of layer gain. Physical aspects of the sample are normally evaluated by Scanning Electron Microscopy (SEM), but it is in many cases unsuitable to provide conclusive chemical information about the distribution of the pharmaceutical ingredients in both layers and core. On the other hand, methods based on spectroscopic imaging can be very promising for this purpose. In this work, a Near-Infrared Chemical Imaging (NIR-CI) method was developed and applied to the analysis of diclophenac sodium pellets. Since all the compounds present in the sample were known in advance, Classical Least Squares (CLS) was used for calculations. The results have shown that the method was capable of providing chemical information about the distribution of the active ingredient and excipients in the core and coating layers and therefore can be complementary to SEM for the pharmaceutical development of pellets.

  2. The approach to risk analysis in three industries: nuclear power, space systems, and chemical process

    International Nuclear Information System (INIS)

    The aerospace, nuclear power, and chemical processing industries are providing much of the incentive for the development and application of advanced risk analysis techniques to engineered systems. Risk analysis must answer three basic questions: What can go wrong? How likely is it? and What are the consequences? The result of such analyses is not only a quantitative answer to the question of 'What is the risk', but, more importantly, a framework for intelligent and visible risk management. Because of the societal importance of the subject industries and the amount of risk analysis activity involved in each, it is interesting to look for commonalities, differences, and, hopefully, a basis for some standardization. Each industry has its strengths: the solid experience base of the chemical industry, the extensive qualification and testing procedures of the space industry, and the integrative and quantitative risk and reliability methodologies developed for the nuclear power industry. In particular, most advances in data handling, systems interaction modeling, and uncertainty analysis have come from the probabilistic risk assessment work in the nuclear safety field. In the final analysis, all three industries would greatly benefit from a more deliberate technology exchange program in the rapidly evolving discipline of quantitative risk analysis. (author)

  3. Chemical imaging and solid state analysis at compact surfaces using UV imaging

    DEFF Research Database (Denmark)

    Wu, Jian X.; Rehder, Sönke; van den Berg, Frans;

    2014-01-01

    Fast non-destructive multi-wavelength UV imaging together with multivariate image analysis was utilized to visualize distribution of chemical components and their solid state form at compact surfaces. Amorphous and crystalline solid forms of the antidiabetic compound glibenclamide, and...... excipients in a non-invasive way, as well as mapping the glibenclamide solid state form. An exploratory data analysis supported the critical evaluation of the mapping results and the selection of model parameters for the chemical mapping. The present study demonstrated that the multi-wavelength UV imaging is...... microcrystalline cellulose together with magnesium stearate as excipients were used as model materials in the compacts. The UV imaging based drug and excipient distribution was in good agreement with hyperspectral NIR imaging. The UV wavelength region can be utilized in distinguishing between glibenclamide and...

  4. THz-Raman: accessing molecular structure with Raman spectroscopy for enhanced chemical identification, analysis, and monitoring

    Science.gov (United States)

    Heyler, Randy A.; Carriere, James T. A.; Havermeyer, Frank

    2013-05-01

    Structural analysis via spectroscopic measurement of rotational and vibrational modes is of increasing interest for many applications, since these spectra can reveal unique and important structural and behavioral information about a wide range of materials. However these modes correspond to very low frequency (~5cm-1 - 200cm-1, or 150 GHz-6 THz) emissions, which have been traditionally difficult and/or expensive to access through conventional Raman and Terahertz spectroscopy techniques. We report on a new, inexpensive, and highly efficient approach to gathering ultra-low-frequency Stokes and anti-Stokes Raman spectra (referred to as "THz-Raman") on a broad range of materials, opening potential new applications and analytical tools for chemical and trace detection, identification, and forensics analysis. Results are presented on explosives, pharmaceuticals, and common elements that show strong THz-Raman spectra, leading to clear discrimination of polymorphs, and improved sensitivity and reliability for chemical identification.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1985-12-01

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

  6. Problem Based Learning (PBL: Analysis of Continuous Stirred Tank Chemical Reactors with a Process Control Approach

    Directory of Open Access Journals (Sweden)

    Regalado-Méndez Alejandro

    2010-10-01

    Full Text Available This work is focused on a project that integrates the curriculum such as thermodynamic, chemical reactorengineering, linear algebra, differential equations and computer programming. The purpose is thatstudents implement the most knowledge and tools to analyse the stirred tank chemical reactor as a simpledynamic system. When the students finished this practice they should have learned about analysis ofdynamic system through bifurcation analysis, hysteresis phenomena, find equilibrium points, stabilitytype, and phase portrait. Once the steps were accomplished, we concluded that the purpose wassatisfactorily reached with an increment in creative ability. The student showed a bigger interesting inthis practice, since they worked in group. The most important fact is that the percentage of failure amongstudents was 10%. Finally, using alternative teaching-learning process improves the Mexican systemeducation.

  7. Quantitative analysis of abused drugs in physiological fluids by gas chromatography/chemical ionization mass spectrometry

    International Nuclear Information System (INIS)

    Methods have been developed for quantitative analysis of commonly abused drugs in physiological fluids using gas chromatography/chemical ionization mass spectrometry. The methods are being evaluated in volunteer analytical and toxicological laboratories, and analytical manuals describing the methods are being prepared. The specific drug and metabolites included in this program are: Δ9-tetrahydrocannabinol, methadone, phencyclidine, methaqualone, morphine, amphetamine, methamphetamine, mescaline, 2,5-dimethoxy-4-methyl amphetamine, cocaine, benzoylecgonine, diazepam, and N-desmethyldiazepam. The current analytical methods utilize relatively conventional instrumentation and procedures, and are capable of measuring drug concentrations as low as 1 ng/ml. Various newer techniques such as sample clean-up by high performance liquid chromatography, separation by glass capillary chromatography, and ionization by negative ion chemical ionization are being investigated with respect to their potential for achieving higher sensitivity and specificity, as well as their ability to facilitate simultaneous analysis of more than one drug and metabolite. (Auth.)

  8. Do provisions to advance chemical facility safety also advance chemical facility security? An analysis of possible synergies

    DEFF Research Database (Denmark)

    Hedlund, Frank Huess

    The European Commission has launched a study on the applicability of existing chemical industry safety provisions to enhancing security of chemical facilities covering the situation in 18 EU Member States. This paper reports some preliminary analytical findings regarding the extent to which...... exist at the mitigation level. At the strategic policy level, synergies are obvious. The security of chemical facilities is important. First, facilities with large inventories of toxic materials could be attractive targets for terrorists. The concern is sabotage causing an intentional release that could...

  9. Micro Chemical (Elemental) Analysis of Leucas aspera (Willd) Link Employing SEM-EDAX

    OpenAIRE

    Sunkara Yashvanth; Satla Shobha Rani; S. S. Madhavendra

    2013-01-01

    The plant, Leucas aspera (Willd) Link is well known for its varied medicinal uses. Present study deals with its micro chemical (elemental) characterization using Energy Dispersive X-ray Analysis (EDAX) detector fitted to Scanning Electron Microscope. The plant has very interesting morphology. Crystals of varied shape and inclusions/exudates were noticed within and on the leaf & stem surfaces. Various plant parts analysed were, stem surface, stem sections, stem inclusions, blebs on stem hairs,...

  10. Quality assessment of mized fruit squash: physico-chemical analysis, senory evaluation and storage studies

    OpenAIRE

    Jothi, J.S.; Karmoker, P.; Sarower, K.

    2014-01-01

    Fruits and vegetables belong to an essential class of foods that supply human diet with nutritive requirements including vitamins and minerals which are essential for normal body health and function. The study was carried out to determine the physico-chemical analysis and sensory qualities of mixed fruit squash. Carrot (Drocus carota), papaya (Carica papaya) and banana (Musa sapientum) juice were standardized to produce mixed squash which was stored for 9 weeks in sterilized glass bottles at ...

  11. Patterns of innovation and organizational demography in emerging sustainable fields: an analysis of the chemical sector.

    OpenAIRE

    Marianna Epicoco

    2014-01-01

    This paper examines the eco-innovation dynamics in the chemical sector by analyzing Sustainable Chemistry (SC) technologies and the organizations that generated those technologies. First, we build an original dataset of patents and investigate trends emerging from patent statistics. Second, by using a clustering algorithm for the analysis of citation networks, we identify the main clusters of innovations that are driving the evolution of the field and analyze the demography of involved organi...

  12. Spatial Autocorrelation Analysis of Chinese Inter-Provincial Industrial Chemical Oxygen Demand Discharge

    OpenAIRE

    Yibo Liu; Xianjin Huang; Xiaofeng Zhao

    2012-01-01

    A spatial autocorrelation analysis method is adopted to process the spatial dynamic change of industrial Chemical Oxygen Demand (COD) discharge in China over the past 15 years. Studies show that amount and intensity of industrial COD discharges are on a decrease, and the tendency is more remarkable for discharge intensity. There are large differences between inter-provincial discharge amount and intensity, and with different spatial differentiation features. Global spatial autocorrelation ana...

  13. Quality system of the Chemical Analysis Laboratory to fulfill the requirements with Certification Organizations

    International Nuclear Information System (INIS)

    In the present work was described the Quality System established in the Chemical Analysis Department to fulfill with the Organization requirements, personnel, measurement equipment, calibration, working procedures, etc. to get official acknowledgment by the National Assurance System for Testing laboratories, dependent of the General Standards Direction. There are described the available resources, the performance and control of each of one principal points of the system. (Author)

  14. CHEMICAL ANALYSIS AND ANTIOXIDANT ACTIVITY OF âNERIUM OLEANDERâ LEAVES

    OpenAIRE

    Lakhmili Siham; Obraim Saida; Taourirte Moha; Seddiqi Nadia; Amraoui Hakima

    2014-01-01

    The phenolic products of medicinal plants have a great pharmacological interest. This product gives the powers of medicinal plants. They are the source of several active principles widely used in modern medicine. The use of Nerium oleander in Moroccan traditional medicine is very common. Few studies have focused on the chemical analysis and phenolic compounds of this plant. For this, we investigated the mineral composition and phenolic combination of the leaves oleander and the study of the a...

  15. "A Note on New Product Project Selection Model: Empirical Analysis in Chemical Industry" (in Japanese)

    OpenAIRE

    Kenichi Kuwashima; Junichi Tomita

    2001-01-01

    By focusing its attention on one particular scoring method that is used to evaluate R&D projects, this paper seeks to specify empirically the factors that discriminate successful projects from failed projects in the Japanese chemical industry. Our statistical analysis revealed that when projects are evaluated in this industry, three factors, marketability, technology, and synergistic potential, tend to be valued by practitioners approximately in a 3:2:1 ratio. Although the project evaluations...

  16. PHYSICO CHEMICAL ANALYSIS OF PANCHAVAKTRA RAS: A HERBO-MINERAL FORMULATION

    OpenAIRE

    Bandari Srinivasulu; P Bhadra Dev; P H C Murthy

    2013-01-01

    Panchavaktra Ras is a rational combination of Rasadravyas and Kasthaushadhis prescribed in the management of Amavata. Panchavaktra rasa has been taken into consideration for its Pharmaceutical standardization through Standard Operative procedures. In pharmaceutical study, the drug has been prepared in 3 batches adopting Khalviya Rasayana method and physico chemical analysis was carried out on these batches. This formulation was analysed by using Inductively Coupled Plasma with Optical Emissio...

  17. Fourier-Domain Analysis of Hydriding Kinetics Using Pneumato-Chemical Impedance Spectroscopy

    OpenAIRE

    Millet, P.; C. Decaux; R. Ngameni; Guymont, M.

    2007-01-01

    Analysis of phase transformation processes observed in hydrogen absorbing materials (pure metals, alloys, or compounds) is still a matter of active research. Using pneumato-chemical impedance spectroscopy (PIS), it is now possible to analyze the mechanism of hydriding reactions induced by the gas phase. Experimental impedance diagrams, measured on activated LaNi5 in single- and two-phase domains, are reported in this paper. It is shown that their shape is mostly affected by the slope of the i...

  18. Evaluation of Three Flow Injection Analysis Methods for the Determination of Chemical Oxygen Demand

    OpenAIRE

    Korenaga, Takashi; Moriwake, Tosio; Takahashi, Teruo

    1984-01-01

    Three methods for determining chemical oxygen demand (COD) by means of flow injection analysis (FIA) with potassium permanganate, potassium dichromate, or cerium(IV) sulfate as oxidant, developed in this laboratory, are described from the point of view of their operating properties. The permanganate method is the most sensitive and common, but forms manganese(IV) oxide precipitate which blocks the FIA lines and connectors. Addition of phosphoric acid in the reagent system is, however, effecti...

  19. Decomposition analysis of green chemical technology inventions from 1971 to 2010 in Japan

    OpenAIRE

    Fujii, Hidemichi; Shirakawa, Seiji

    2015-01-01

    Green chemistry plays an important role in achieving sustainable development. This study examines the determinant factors for technology invention related to green chemistry in Japan using patent application data and a decomposition analysis framework. Our main findings are that the number of green chemical technologies applied to production processes have increased because of the scale-up of overall research activities and increased priority. Additionally, the number of patent applications f...

  20. Chemical sensors and the development of potentiometric methods for liquid media analysis

    International Nuclear Information System (INIS)

    Aspects of applying indirect potentiometric determination to chemical analysis are considered. Among them are the standard and modified addition and subtraction methods, the multiple addition method, and potentiometric titration using ion-selective electrodes as indicators. These methods significantly extend the capabilities of ion-selective potentiometric analysis. Conditions for the applicability of the above-mentioned methods to various samples (Cd, REE, Th, iodides and others) are discussed using all available ion-selective electrodes as examples. 162 refs., 2 figs., 5 tabs

  1. Thermal and Chemical Characterization of Non-Metallic Materials Using Coupled Thermogravimetric Analysis and Infrared Spectroscopy

    Science.gov (United States)

    Huff, Timothy L.

    2002-01-01

    Thermogravimetric analysis (TGA) is widely employed in the thermal characterization of non-metallic materials, yielding valuable information on decomposition characteristics of a sample over a wide temperature range. However, a potential wealth of chemical information is lost during the process, with the evolving gases generated during thermal decomposition escaping through the exhaust line. Fourier Transform-Infrared spectroscopy (FT-IR) is a powerful analytical technique for determining many chemical constituents while in any material state, in this application, the gas phase. By linking these two techniques, evolving gases generated during the TGA process are directed into an appropriately equipped infrared spectrometer for chemical speciation. Consequently, both thermal decomposition and chemical characterization of a material may be obtained in a single sample run. In practice, a heated transfer line is employed to connect the two instruments while a purge gas stream directs the evolving gases into the FT-IR. The purge gas can be either high purity air or an inert gas such as nitrogen to allow oxidative and pyrolytic processes to be examined, respectively. The FT-IR data is collected realtime, allowing continuous monitoring of chemical compositional changes over the course of thermal decomposition. Using this coupled technique, an array of diverse materials has been examined, including composites, plastics, rubber, fiberglass epoxy resins, polycarbonates, silicones, lubricants and fluorocarbon materials. The benefit of combining these two methodologies is of particular importance in the aerospace community, where newly developing materials have little available data with which to refer. By providing both thermal and chemical data simultaneously, a more definitive and comprehensive characterization of the material is possible. Additionally, this procedure has been found to be a viable screening technique for certain materials, with the generated data useful in

  2. Tooth matrix analysis for biomonitoring of organic chemical exposure: Current status, challenges, and opportunities.

    Science.gov (United States)

    Andra, Syam S; Austin, Christine; Arora, Manish

    2015-10-01

    Epidemiological evidence supports associations between prenatal exposure to environmental organic chemicals and childhood health impairments. Unlike the common choice of biological matrices such as urine and blood that can be limited by short half-lives for some chemicals, teeth provide a stable repository for chemicals with half-life in the order of decades. Given the potential of the tooth bio-matrix to study long-term exposures to environmental organic chemicals in human biomonitoring programs, it is important to be aware of possible pitfalls and potential opportunities to improve on the current analytical method for tooth organics analysis. We critically review previous results of studies of this topic. The major drawbacks and challenges in currently practiced concepts and analytical methods in utilizing tooth bio-matrix are (i) no consideration of external (from outer surface) or internal contamination (from micro-odontoblast processes), (ii) the misleading assumption that whole ground teeth represent prenatal exposures (latest formed dentine is lipid rich and therefore would absorb and accumulate more organic chemicals), (iii) reverse causality in exposure assessment due to whole ground teeth, and (iv) teeth are a precious bio-matrix and grinding them raises ethical concerns about appropriate use of a very limited resource in exposure biology and epidemiology studies. These can be overcome by addressing the important limitations and possible improvements with the analytical approach associated at each of the following steps: (i) tooth sample preparation to retain exposure timing, (ii) organics extraction and pre-concentration to detect ultra-trace levels of analytes, (iii) chromatography separation, (iv) mass spectrometric detection to detect multi-class organics simultaneously, and (v) method validation, especially to exclude chance findings. To highlight the proposed improvements we present findings from a pilot study that utilizes tooth matrix biomarkers

  3. Ultrasonic nebulization extraction/low pressure photoionization mass spectrometry for direct analysis of chemicals in matrices.

    Science.gov (United States)

    Liu, Chengyuan; Zhu, Yanan; Zhou, Zhongyue; Yang, Jiuzhong; Qi, Fei; Pan, Yang

    2015-09-01

    A novel ultrasonic nebulization extraction/low-pressure photoionization (UNE-LPPI) system has been designed and employed for the rapid mass spectrometric analysis of chemicals in matrices. An ultrasonic nebulizer was used to extract the chemicals in solid sample and nebulize the solvent in the nebulization cell. Aerosols formed by ultrasonic were evaporated by passing through a transferring tube, and desolvated chemicals were ionized by the emitted light (10.6 eV) from a Krypton discharge lamp at low pressure (∼68 Pa). First, a series of semi/non-volatile compounds with different polarities, such as polycyclic aromatic hydrocarbons (PAHs), amino acids, dipeptides, drugs, nucleic acids, alkaloids, and steroids were used to test the system. Then, the quantification capability of UNE-LPPI was checked with: 1) pure chemicals, such as 9,10-phenanthrenequinone and 1,4-naphthoquinone dissolved in solvent; 2) soil powder spiked with different amounts of phenanthrene and pyrene. For pure chemicals, the correlation coefficient (R(2)) for the standard curve of 9,10-phenanthrenequinone in the range of 3 ng-20 μg mL(-1) was 0.9922, and the measured limits of detection (LOD) was 1 ng ml(-1). In the case of soil powder, linear relationships for phenanthrene and pyrene from 10 to 400 ng mg(-1) were obtained with correlation coefficients of 0.9889 and 0.9893, respectively. At last, the feasibility of UNE-LPPI for the detection of chemicals in real matrices such as tablets and biological tissues (tea, Citrus aurantium peel and sage (Salvia officinalis) leaf) were successfully demonstrated. PMID:26388379

  4. Enhanced Chemical Incident Response Plan (ECIRP). Appendix F, remediation analysis with Decision Support Tools (DSTs) for wide-area chemical hazards.

    Energy Technology Data Exchange (ETDEWEB)

    Hassig, Nancy L. (Pacific Northwest National Laboratory, Richland, WA); Pulsipher, Brent A. (Pacific Northwest National Laboratory, Richland, WA); Foltz, Greg W.; Hoette, Trisha Marie

    2011-07-01

    The Defense Threat Reduction Agency (DTRA) commissioned an assessment of the Consequence Management (CM) plans in place on military bases for response to a chemical attack. The effectiveness of the CM plans for recovering from chemical incidents was modeled using a multiple Decision Support Tools (DSTs). First, a scenario was developed based on an aerial dispersion of a chemical agent over a wide-area of land. The extent of contamination was modeled with the Hazard Prediction and Assessment Capability (HPAC) tool. Subsequently, the Analyzer for Wide Area Restoration Effectiveness (AWARE) tool was used to estimate the cost and time demands for remediation based on input of contamination maps, sampling and decontamination resources, strategies, rates and costs. The sampling strategies incorporated in the calculation were designed using the Visual Sample Plan (VSP) tool. Based on a gaps assessment and the DST remediation analysis, an Enhanced Chemical Incident Response Plan (ECIRP) was developed.

  5. Physical chemical analysis of marine sediment cementation from the Gulf of Guinea

    Science.gov (United States)

    Liu, Xianfeng; Hammad, Tammam; Saiyouri, Nadia; Hattab, Mahdia

    2012-09-01

    This study aims at investigating the cementation of marine sediments from the Gulf of Guinea by using physicochemical analysis. In order to highlight the presence of cementation in the sediments, three conventional consolidation tests were conducted on intact and remoulded samples. Mercury intrusion porosimetry analyses were then carried out on the specimens taken from samples after consolidation tests. Several physicochemical experimental techniques were used to analyze these cementations, such as cation exchange capacity analysis, batch test, scanning electron microscope imaging coupled with EDS chemical analysis, and thermal analysis. The results seem to indicate that the cementation of these sediments is predominated by the presence of smectite gel between clay aggregates (clusters). Finally, a conceptual sediment microstructural model is proposed to describe the cementation.

  6. A chemical profiling strategy for semi-quantitative analysis of flavonoids in Ginkgo extracts.

    Science.gov (United States)

    Yang, Jing; Wang, An-Qi; Li, Xue-Jing; Fan, Xue; Yin, Shan-Shan; Lan, Ke

    2016-05-10

    Flavonoids analysis in herbal products is challenged by their vast chemical diversity. This work aimed to develop a chemical profiling strategy for the semi-quantification of flavonoids using extracts of Ginkgo biloba L. (EGB) as an example. The strategy was based on the principle that flavonoids in EGB have an almost equivalent molecular absorption coefficient at a fixed wavelength. As a result, the molecular-contents of flavonoids were able to be semi-quantitatively determined by the molecular-concentration calibration curves of common standards and recalculated as the mass-contents with the characterized molecular weight (MW). Twenty batches of EGB were subjected to HPLC-UV/DAD/MS fingerprinting analysis to test the feasibility and reliability of this strategy. The flavonoid peaks were distinguished from the other peaks with principle component analysis and Pearson correlation analysis of the normalized UV spectrometric dataset. Each flavonoid peak was subsequently tentatively identified by the MS data to ascertain their MW. It was highlighted that the flavonoids absorption at Band-II (240-280 nm) was more suitable for the semi-quantification purpose because of the less variation compared to that at Band-I (300-380 nm). The semi-quantification was therefore conducted at 254 nm. Beyond the qualitative comparison results acquired by common chemical profiling techniques, the semi-quantitative approach presented the detailed compositional information of flavonoids in EGB and demonstrated how the adulteration of one batch was achieved. The developed strategy was believed to be useful for the advanced analysis of herbal extracts with a high flavonoid content without laborious identification and isolation of individual components. PMID:26907698

  7. Analysis of Chemical Constituents in Wuzi-Yanzong-Wan by UPLC-ESI-LTQ-Orbitrap-MS.

    Science.gov (United States)

    Zou, Dixin; Wang, Jinfeng; Zhang, Bo; Xie, Suhua; Wang, Qing; Xu, Kexin; Lin, Ruichao

    2015-01-01

    Wuzi-Yanzong-Wan (WZYZW), a classical traditional Chinese medicine (TCM) prescription containing Fructus Lych, Semen Cuscutae (fried), Fructus Rubi, Fructus Schisandrae chinensis (steamed) and Semen Plantaginis (fried with salt), is widely used to treat impotence, sterility, spermatorrhea, premature ejaculation, lumbago and post-micturation dribble. However, the chemical profile of WZYZW has not been established yet. In this work, a rapid and sensitive method for systematically screening and identifying the chemical constituents of WZYZW in both positive and negative ion modes using Ultra-Performance LC coupled with ESI-linear ion trap-Orbitrap tandem mass spectrometry (UPLC-ESI-LTQ-Orbitrap-MS) has been developed. Based on the chromatographic and spectrometric data, and referring to the literature, we could tentatively identify 106 compounds, including organic acids, flavonoids, phenylpropanoids, alkaloids and terpenoids. Fourteen ingredients from Fructus Lych were identified, while 10 ingredients were from Semen Cuscutae (fried), 33 ingredients were from Fructus Rubi, 37 ingredients were from Fructus Schisandrae chinensis (steamed), and 20 ingredients were from Semen Plantaginis (fried with salt). The results may provide essential data for further quality control, pharmacological research and clinical evaluation of WZYZW. Furthermore, this study indicates the developed approach based on UPLC-ESI-LTQ-Orbitrap-MS is suitable for characterizing the chemical profiles of TCM prescriptions. This is the first report to provide a comprehensive analysis of the chemical constituents of WZYZW. PMID:26633334

  8. Analysis of Chemical Constituents in Wuzi-Yanzong-Wan by UPLC-ESI-LTQ-Orbitrap-MS

    Directory of Open Access Journals (Sweden)

    Dixin Zou

    2015-12-01

    Full Text Available Wuzi-Yanzong-Wan (WZYZW, a classical traditional Chinese medicine (TCM prescription containing Fructus Lych, Semen Cuscutae (fried, Fructus Rubi, Fructus Schisandrae chinensis (steamed and Semen Plantaginis (fried with salt, is widely used to treat impotence, sterility, spermatorrhea, premature ejaculation, lumbago and post-micturation dribble. However, the chemical profile of WZYZW has not been established yet. In this work, a rapid and sensitive method for systematically screening and identifying the chemical constituents of WZYZW in both positive and negative ion modes using Ultra-Performance LC coupled with ESI-linear ion trap-Orbitrap tandem mass spectrometry (UPLC-ESI-LTQ-Orbitrap-MS has been developed. Based on the chromatographic and spectrometric data, and referring to the literature, we could tentatively identify 106 compounds, including organic acids, flavonoids, phenylpropanoids, alkaloids and terpenoids. Fourteen ingredients from Fructus Lych were identified, while 10 ingredients were from Semen Cuscutae (fried, 33 ingredients were from Fructus Rubi, 37 ingredients were from Fructus Schisandrae chinensis (steamed, and 20 ingredients were from Semen Plantaginis (fried with salt. The results may provide essential data for further quality control, pharmacological research and clinical evaluation of WZYZW. Furthermore, this study indicates the developed approach based on UPLC-ESI-LTQ-Orbitrap-MS is suitable for characterizing the chemical profiles of TCM prescriptions. This is the first report to provide a comprehensive analysis of the chemical constituents of WZYZW.

  9. Pathway analysis and exposure assessment: MEPAS modeling for nonradiological chemical contaminants at the Hanford Site

    International Nuclear Information System (INIS)

    A Chemical Pathway Analysis and Exposure Assessment was performed by the Surface Environmental Surveillance Project (SESP). The SESP monitors air, surface water, sediment, agricultural products, vegetation, soil, and wildlife in order to assess onsite of offsite environmental impacts and offsite human health risk at the Hanford Site. The objectives of this study are (1) determine if a nonradiological chemical monitoring program is warranted for the Hanford Site, (2) ensure that the selection of surveillance parameters such as media, sampling location, and analytes are chosen in a manner that is scientifically sound and cost-efficient, and (3) identify specific nonradiological chemicals of concern (COC) for the Hanford Site. The basis for identification of COC for the Hanford Site was an extensive literature review. The model was also used to predict COC concentrations required onsite to achieve an offsite cancer incidence of 1 E-6 and a hazard quotient of 1.0. This study indicated that nonradiological chemical contamination occurring onsite does not pose a significant offsite human health risk. The highest cancer incidence to the offsite maximally exposed individual from COC was from arsenic (1.76E-1 0); the highest hazard quotient was chromium VI (1.48E-04)

  10. Embedded Fragments from U.S. Military Personnel—Chemical Analysis and Potential Health Implications

    Directory of Open Access Journals (Sweden)

    José A. Centeno

    2014-01-01

    Full Text Available Background: The majority of modern war wounds are characterized by high-energy blast injuries containing a wide range of retained foreign materials of a metallic or composite nature. Health effects of retained fragments range from local or systemic toxicities to foreign body reactions or malignancies, and dependent on the chemical composition and corrosiveness of the fragments in vivo. Information obtained by chemical analysis of excised fragments can be used to guide clinical decisions regarding the need for fragment removal, to develop therapeutic interventions, and to better anticipate future medical problems from retained fragment related injuries. In response to this need, a new U.S Department of Defense (DoD directive has been issued requiring characterization of all removed fragments to provide a database of fragment types occurring in combat injuries. Objectives: The objective of this study is to determine the chemical composition of retained embedded fragments removed from injured military personnel, and to relate results to histological findings in tissue adjacent to fragment material. Methods: We describe an approach for the chemical analysis and characterization of retained fragments and adjacent tissues, and include case examples describing fragments containing depleted uranium (DU, tungsten (W, lead (Pb, and non-metal foreign bodies composed of natural and composite materials. Fragments obtained from four patients with penetrating blast wounds to the limbs were studied employing a wide range of chemical and microscopy techniques. Available adjacent tissues from three of the cases were histologically, microscopically, and chemically examined. The physical and compositional properties of the removed foreign material surfaces were examined with energy dispersive x-ray fluorescence spectrometry (EDXRF, scanning electron microscopy (SEM, laser ablation inductively-coupled plasma mass-spectrometry (LA-ICP-MS, and confocal laser Raman

  11. Embedded Fragments from U.S. Military Personnel—Chemical Analysis and Potential Health Implications

    Science.gov (United States)

    Centeno, José A.; Rogers, Duane A.; van der Voet, Gijsbert B.; Fornero, Elisa; Zhang, Lingsu; Mullick, Florabel G.; Chapman, Gail D.; Olabisi, Ayodele O.; Wagner, Dean J.; Stojadinovic, Alexander; Potter, Benjamin K.

    2014-01-01

    Background: The majority of modern war wounds are characterized by high-energy blast injuries containing a wide range of retained foreign materials of a metallic or composite nature. Health effects of retained fragments range from local or systemic toxicities to foreign body reactions or malignancies, and dependent on the chemical composition and corrosiveness of the fragments in vivo. Information obtained by chemical analysis of excised fragments can be used to guide clinical decisions regarding the need for fragment removal, to develop therapeutic interventions, and to better anticipate future medical problems from retained fragment related injuries. In response to this need, a new U.S Department of Defense (DoD) directive has been issued requiring characterization of all removed fragments to provide a database of fragment types occurring in combat injuries. Objectives: The objective of this study is to determine the chemical composition of retained embedded fragments removed from injured military personnel, and to relate results to histological findings in tissue adjacent to fragment material. Methods: We describe an approach for the chemical analysis and characterization of retained fragments and adjacent tissues, and include case examples describing fragments containing depleted uranium (DU), tungsten (W), lead (Pb), and non-metal foreign bodies composed of natural and composite materials. Fragments obtained from four patients with penetrating blast wounds to the limbs were studied employing a wide range of chemical and microscopy techniques. Available adjacent tissues from three of the cases were histologically, microscopically, and chemically examined. The physical and compositional properties of the removed foreign material surfaces were examined with energy dispersive x-ray fluorescence spectrometry (EDXRF), scanning electron microscopy (SEM), laser ablation inductively-coupled plasma mass-spectrometry (LA-ICP-MS), and confocal laser Raman

  12. Methodology for the physical and chemical exergetic analysis of steam boilers

    International Nuclear Information System (INIS)

    This paper presents a framework of thermodynamic, energy and exergy, analyses of industrial steam boilers. Mass, energy, and exergy analysis were used to develop a methodology for evaluating thermodynamic properties, energy and exergy input and output resources in industrial steam boilers. Determined methods make available an analytic procedure for the physical and chemical exergetic analysis of steam boilers for appropriate applications. The energy and exergy efficiencies obtained for the entire boiler was 69.56% and 38.57% at standard reference state temperature of 25 °C for an evaporation ratio of 12. Chemical exergy of the material streams was considered to offer a more comprehensive detail on energy and exergy resource allocation and losses of the processes in a steam boiler. - Highlights: ► We evaluated thermodynamic properties and performance variables associated with material streams. ► We analysed resources allocation, and magnitude of exergetic losses in steam boilers. ► Chemical exergy of material streams contributed to improved exergy values. ► High operational parameter will lead to higher boiler exergy. ► Exergy destroyed was higher in the combustion as against the heat exchanging unit

  13. Application of quantum dots as analytical tools in automated chemical analysis: A review

    Energy Technology Data Exchange (ETDEWEB)

    Frigerio, Christian; Ribeiro, David S.M.; Rodrigues, S. Sofia M.; Abreu, Vera L.R.G.; Barbosa, Joao A.C.; Prior, Joao A.V.; Marques, Karine L. [REQUIMTE, Laboratory of Applied Chemistry, Department of Chemical Sciences, Faculty of Pharmacy of Porto University, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto (Portugal); Santos, Joao L.M., E-mail: joaolms@ff.up.pt [REQUIMTE, Laboratory of Applied Chemistry, Department of Chemical Sciences, Faculty of Pharmacy of Porto University, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto (Portugal)

    2012-07-20

    Highlights: Black-Right-Pointing-Pointer Review on quantum dots application in automated chemical analysis. Black-Right-Pointing-Pointer Automation by using flow-based techniques. Black-Right-Pointing-Pointer Quantum dots in liquid chromatography and capillary electrophoresis. Black-Right-Pointing-Pointer Detection by fluorescence and chemiluminescence. Black-Right-Pointing-Pointer Electrochemiluminescence and radical generation. - Abstract: Colloidal semiconductor nanocrystals or quantum dots (QDs) are one of the most relevant developments in the fast-growing world of nanotechnology. Initially proposed as luminescent biological labels, they are finding new important fields of application in analytical chemistry, where their photoluminescent properties have been exploited in environmental monitoring, pharmaceutical and clinical analysis and food quality control. Despite the enormous variety of applications that have been developed, the automation of QDs-based analytical methodologies by resorting to automation tools such as continuous flow analysis and related techniques, which would allow to take advantage of particular features of the nanocrystals such as the versatile surface chemistry and ligand binding ability, the aptitude to generate reactive species, the possibility of encapsulation in different materials while retaining native luminescence providing the means for the implementation of renewable chemosensors or even the utilisation of more drastic and even stability impairing reaction conditions, is hitherto very limited. In this review, we provide insights into the analytical potential of quantum dots focusing on prospects of their utilisation in automated flow-based and flow-related approaches and the future outlook of QDs applications in chemical analysis.

  14. Application of quantum dots as analytical tools in automated chemical analysis: A review

    International Nuclear Information System (INIS)

    Highlights: ► Review on quantum dots application in automated chemical analysis. ► Automation by using flow-based techniques. ► Quantum dots in liquid chromatography and capillary electrophoresis. ► Detection by fluorescence and chemiluminescence. ► Electrochemiluminescence and radical generation. - Abstract: Colloidal semiconductor nanocrystals or quantum dots (QDs) are one of the most relevant developments in the fast-growing world of nanotechnology. Initially proposed as luminescent biological labels, they are finding new important fields of application in analytical chemistry, where their photoluminescent properties have been exploited in environmental monitoring, pharmaceutical and clinical analysis and food quality control. Despite the enormous variety of applications that have been developed, the automation of QDs-based analytical methodologies by resorting to automation tools such as continuous flow analysis and related techniques, which would allow to take advantage of particular features of the nanocrystals such as the versatile surface chemistry and ligand binding ability, the aptitude to generate reactive species, the possibility of encapsulation in different materials while retaining native luminescence providing the means for the implementation of renewable chemosensors or even the utilisation of more drastic and even stability impairing reaction conditions, is hitherto very limited. In this review, we provide insights into the analytical potential of quantum dots focusing on prospects of their utilisation in automated flow-based and flow-related approaches and the future outlook of QDs applications in chemical analysis.

  15. PACSY, a relational database management system for protein structure and chemical shift analysis

    International Nuclear Information System (INIS)

    PACSY (Protein structure And Chemical Shift NMR spectroscopY) is a relational database management system that integrates information from the Protein Data Bank, the Biological Magnetic Resonance Data Bank, and the Structural Classification of Proteins database. PACSY provides three-dimensional coordinates and chemical shifts of atoms along with derived information such as torsion angles, solvent accessible surface areas, and hydrophobicity scales. PACSY consists of six relational table types linked to one another for coherence by key identification numbers. Database queries are enabled by advanced search functions supported by an RDBMS server such as MySQL or PostgreSQL. PACSY enables users to search for combinations of information from different database sources in support of their research. Two software packages, PACSY Maker for database creation and PACSY Analyzer for database analysis, are available from http://pacsy.nmrfam.wisc.eduhttp://pacsy.nmrfam.wisc.edu.

  16. Physico-Chemical Analysis of Selected Groundwater Samples of Inkollu Mandal, Prakasam District, Andhra Pradesh, India

    Directory of Open Access Journals (Sweden)

    G. Arun Kumar

    2015-04-01

    Full Text Available Physico-chemical parameters of groundwater quality based on Physic-chemical parameters at Inkollu mandal, Prakasam district, Andhra Pradesh, India have been taken up to evaluate its suitability for Drinking purpose. Nine ground water samples were collected from different places of Inkollu mandal of Prakasam district. The quality analysis has been made through the pH, EC, TDS, Total Hardness, Sodium, Potassium, Calcium, Magnesium, Chloride, Sulphate, Nitrate, Fluoride and Iron. By observing the results, it was shown that the parameters from the water samples were compared with WHO (World Health Organization and BIS (Bureau of Indian Standards, USPH (United state Public health for ground water .The results revealed that some parameters were in high concentration and quality of the potable water has deteriorated to a large extent at some sampling locations.

  17. Instrumental neutron activation analysis applied to the chemical composition of steel

    International Nuclear Information System (INIS)

    In the technological application of steel, the knowledge of its chemical composition is of fundamental importance as it is directly related to various properties, such as, mechanical properties, corrosion resistance, temperability and others. Instrumental Neutron Activation Analysis, INAA, is an appropriate technique in the evaluation of the chemical composition of steel and other metallurgical materials due to the possibility of simultaneous determination of a great number of elements without the inconvenience of sample dissolution. Element determination is achieved with good accuracy and precision for major and minor constituents as well as for trace elements. In this paper, INAA was used in the determination of As, Co, Cu, Mn, Mo, V and W in steel and iron samples and in certified reference materials. The obtained accuracy and precision were less than 10% for most of the elements confirming the possibility of its use in the study of metallic samples and in the certification of new reference materials. (author)

  18. Computer-Aided Modelling of Short-Path Evaporation for Chemical Product Purification, Analysis and Design

    DEFF Research Database (Denmark)

    Sales-Cruz, Alfonso Mauricio; Gani, Rafiqul

    2006-01-01

    An important stage in the design process for many chemical products is its manufacture where, for a class of chemical products that may be thermally unstable (such as, drugs, insecticides, flavours /fragrances, and so on), the purification step plays a major role. Short-path evaporation is a safe...... method, suitable for separation and purification of thermally unstable materials whose design and analysis can be efficiently performed through reliable model-based techniques. This paper presents a generalized model for short-path evaporation and highlights its development, implementation and solution...... glycerol, mono-, di- and triglycerides, and (b) the recovery of a pharmaceutical product from a six-component mixture. Validation of the short-path evaporation model is highlighted through the comparison of experimental data from an industrial pilot plant with the simulated results from the model. Also...

  19. Analysis of solar chemical processes for hydrogen production from water splitting thermochemical cycles

    International Nuclear Information System (INIS)

    This paper presents a process analysis of ZnO/Zn, Fe3O4/FeO and Fe2O3/Fe3O4 thermochemical cycles as potential high efficiency, large scale and environmentally attractive routes to produce hydrogen by concentrated solar energy. Mass and energy balances allowed estimation of the efficiency of solar thermal energy to hydrogen conversion for current process data, accounting for chemical conversion limitations. Then, the process was optimized by taking into account possible improvements in chemical conversion and heat recoveries. Coupling of the thermochemical process with a solar tower plant providing concentrated solar energy was considered to scale up the system. An economic assessment gave a hydrogen production cost of 7.98$ kg-1 and 14.75$ kg-1 of H2 for, respectively a 55 MWth and 11 MWth solar tower plant operating 40 years

  20. Chemical contents in Lygeum spartum L. using instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Nedjimi, Bouzid [Djelfa Univ. (Algeria). Lab. of Exploration and Valorization of Steppe Ecosystem; Beladel, Brahim [Djelfa Univ. (Algeria)

    2015-09-01

    The present investigation was conducted to determine the chemical contents of Lygeum spartum L. (Poaceae). Samples were analyzed in order to determine essential (Ca, K, Na, Fe, Co) and some potentially toxic elements (Eu, Sb, Tb) using instrumental neutron activation analysis (INAA). In general chemical element contents were in substantial amounts to meet adult sheep requirements. Potential intake of Ca, K, Zn, Co and Fe by ruminant weighing 50 kg BW consuming 2.0 kg per day DM was sufficient to satisfy their requirements. However, only Na level was still insufficient to meet the requirements for grazing ruminants. Potential toxic elements in this species were within the safety baseline of all the assayed elements recommended by NRC. Na supplementation would seem to be necessary in this zone, for optimum productivity of grazing animals.

  1. Chemical analysis of human urinary and renal calculi by Raman laser fiber-optics method

    Science.gov (United States)

    Hong, Nguyen T. D.; Phat, Darith; Plaza, Pascal; Daudon, Michel; Dao, Nguyen Q.

    1991-11-01

    The Raman laser fiberoptics (RLFO) method using Raman spectroscopy for determination of chemical composition and optical fibers allowing multiplex, in situ, and remote possibilities, enabled chemical analysis of various human urinary and renal calculi. Raman spectra of about 40 constituents (synthetic or natural) in the authors''s possession and its 437 various binary and ternary mixtures are recorded using 1.06 micrometers radiation of a Nd:YAG laser and a FT Raman interferometer. These spectra--most of them are fluorescence free--constituted the calculi library. In the presence of urine, unknown stones can then be identified by RLFO method using an automatic computer procedure (at the present time, the Bruker IR search program is used). The results obtained for the identification of the stones are satisfactory. Major constituents of a complex calculus (

  2. Chemical contents in Lygeum spartum L. using instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    The present investigation was conducted to determine the chemical contents of Lygeum spartum L. (Poaceae). Samples were analyzed in order to determine essential (Ca, K, Na, Fe, Co) and some potentially toxic elements (Eu, Sb, Tb) using instrumental neutron activation analysis (INAA). In general chemical element contents were in substantial amounts to meet adult sheep requirements. Potential intake of Ca, K, Zn, Co and Fe by ruminant weighing 50 kg BW consuming 2.0 kg per day DM was sufficient to satisfy their requirements. However, only Na level was still insufficient to meet the requirements for grazing ruminants. Potential toxic elements in this species were within the safety baseline of all the assayed elements recommended by NRC. Na supplementation would seem to be necessary in this zone, for optimum productivity of grazing animals.

  3. Reaction path analysis of sodium-water chemical reaction field using laser diagnostics

    International Nuclear Information System (INIS)

    In a sodium-cooled fast reactor (SFR), liquid sodium is used as a heat transfer fluid because of its excellent heat transport capability. On the other hand, it has strong chemical reactivity with water vapor. One of the design basis accidents of the SFR is the water leakage into the liquid sodium flow by a breach of heat transfer tubes. Therefore, the study on sodium-water chemical reactions is of importance for security reasons. This study aims to clarify the gas phase sodium-water reaction path and reaction products. Na, Na2, H2O, and reaction products in the counter-flow sodium-water reaction field were measured using laser diagnostics such as Raman scattering and photo-fragmentation. The main product in the sodium-water reaction was determined to be NaOH and its reaction path was discussed using Na-H2O elementally reaction analysis. (author)

  4. Integrated risk analysis for acute and chronic exposure to toxic chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Gurjar, B.R.; Mohan, Manju

    2003-10-01

    The traditional practice to assess and evaluate different types of risk in isolation to each other are liable to give erroneous results. Integrated risk assessment is an answer to overcome this problem. This paper presents the cumulative or integrated assessment of acute risk posed by accidental release of hazardous chemical (e.g. chlorine) and chronic risk induced by toxic chemicals (e.g. cadmium, chromium and nickel) present in the ambient environment. The present study has been carried out in a most simplified way to demonstrate and appreciate the broader context of integrated risk analysis (IRA). It has been observed that the inclusion of background risk factors (BRF) in individual risk factors (IRF) related to an industry may significantly alter the siting and planning strategies of that industry.

  5. Kinematic analysis of in situ measurement during chemical mechanical planarization process

    International Nuclear Information System (INIS)

    Chemical mechanical planarization (CMP) is the most widely used planarization technique in semiconductor manufacturing presently. With the aid of in situ measurement technology, CMP tools can achieve good performance and stable productivity. However, the in situ measurement has remained unexplored from a kinematic standpoint. The available related resources for the kinematic analysis are very limited due to the complexity and technical secret. In this paper, a comprehensive kinematic analysis of in situ measurement is provided, including the analysis model, the measurement trajectory, and the measurement time of each zone of wafer surface during the practical CMP process. In addition, a lot of numerical calculations are performed to study the influences of main parameters on the measurement trajectory and the measurement velocity variation of the probe during the measurement process. All the efforts are expected to improve the in situ measurement system and promote the advancement in CMP control system

  6. Standard test methods for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of uranium hexafluoride

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 These test methods cover procedures for subsampling and for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of uranium hexafluoride UF6. Most of these test methods are in routine use to determine conformance to UF6 specifications in the Enrichment and Conversion Facilities. 1.2 The analytical procedures in this document appear in the following order: Note 1—Subcommittee C26.05 will confer with C26.02 concerning the renumbered section in Test Methods C761 to determine how concerns with renumbering these sections, as analytical methods are replaced with stand-alone analytical methods, are best addressed in subsequent publications. Sections Subsampling of Uranium Hexafluoride 7 - 10 Gravimetric Determination of Uranium 11 - 19 Titrimetric Determination of Uranium 20 Preparation of High-Purity U3O 8 21 Isotopic Analysis 22 Isotopic Analysis by Double-Standard Mass-Spectrometer Method 23 - 29 Determination of Hydrocarbons, Chlorocarbons, and Partially Substitut...

  7. The geographical origin and chemical composition in phellinus mushrooms measured by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    In order to expand the utilization of phellinus mushrooms as a dietary supplement, we attempted to evaluate the chemical composition by measuring its inorganic elemental content with the aid of instrumental neutron activation analysis (INAA). Twenty seven phellinus mushrooms samples were collected from Korea, Cambodia, and Vietnam. A total of 28 elements were analyzed in the phellinus mushroom samples using the INAA. The concentrations of Ca, K, and Mg are much higher than those of other elements in phellinus mushroom samples. The sum of determined elemental concentration in Cambodia samples was about 2-6 times higher than those in Korea and Vietnam samples, respectively. Based on our measurement data, we attempted to discriminate the geographical origin using principal components analysis (PCA) and linear discriminant analysis (LDA). The geographical origins of all samples were clearly classified with correct classification rate of 100%. (author)

  8. Histopathological image analysis of chemical-induced hepatocellular hypertrophy in mice.

    Science.gov (United States)

    Asaoka, Yoshiji; Togashi, Yuko; Mutsuga, Mayu; Imura, Naoko; Miyoshi, Tomoya; Miyamoto, Yohei

    2016-04-01

    Chemical-induced hepatocellular hypertrophy is frequently observed in rodents, and is mostly caused by the induction of phase I and phase II drug metabolic enzymes and peroxisomal lipid metabolic enzymes. Liver weight is a sensitive and commonly used marker for detecting hepatocellular hypertrophy, but is also increased by a number of other factors. Histopathological observations subjectively detect changes such as hepatocellular hypertrophy based on the size of a hepatocyte. Therefore, quantitative microscopic observations are required to evaluate histopathological alterations objectively. In the present study, we developed a novel quantitative method for an image analysis of hepatocellular hypertrophy using liver sections stained with hematoxylin and eosin, and demonstrated its usefulness for evaluating hepatocellular hypertrophy induced by phenobarbital (a phase I and phase II enzyme inducer) and clofibrate (a peroxisomal enzyme inducer) in mice. The algorithm of this imaging analysis was designed to recognize an individual hepatocyte through a combination of pixel-based and object-based analyses. Hepatocellular nuclei and the surrounding non-hepatocellular cells were recognized by the pixel-based analysis, while the areas of the recognized hepatocellular nuclei were then expanded until they ran against their expanding neighboring hepatocytes and surrounding non-hepatocellular cells by the object-based analysis. The expanded area of each hepatocellular nucleus was regarded as the size of an individual hepatocyte. The results of this imaging analysis showed that changes in the sizes of hepatocytes corresponded with histopathological observations in phenobarbital and clofibrate-treated mice, and revealed a correlation between hepatocyte size and liver weight. In conclusion, our novel image analysis method is very useful for quantitative evaluations of chemical-induced hepatocellular hypertrophy. PMID:26776450

  9. Microfluidic electrochemical device and process for chemical imaging and electrochemical analysis at the electrode-liquid interface in-situ

    Science.gov (United States)

    Yu, Xiao-Ying; Liu, Bingwen; Yang, Li; Zhu, Zihua; Marshall, Matthew J.

    2016-03-01

    A microfluidic electrochemical device and process are detailed that provide chemical imaging and electrochemical analysis under vacuum at the surface of the electrode-sample or electrode-liquid interface in-situ. The electrochemical device allows investigation of various surface layers including diffuse layers at selected depths populated with, e.g., adsorbed molecules in which chemical transformation in electrolyte solutions occurs.

  10. Accuracy of chemical analysis of airborne particulates: results of an intercomparison exercise

    International Nuclear Information System (INIS)

    Since suitable standard reference materials for chemical analysis of airborne particulates are not available, an intercomparison exercise was carried out among 40 interested laboratories in order to evaluate the accuracy of various trace analysis techniques for this specific application. Six hundred grams of airborne particulates were collected from the inlet filters of the air conditioning installation of a hotel in the center of Milan. The sample was sieved to remove coarser particles, thoroughly mixed, and distributed in 1 to 5 gram aliquots. The homogeneity was checked by relative measurements carried out by three independent techniques. For 40 elements no inhomogeneity was found to exceed the analytical error, which was estimated to be approximately 10 percent. The data of the analytical exercise are being collected and evaluated. Results are available for 56 elements, but to date only 33 have been determined by more than one technique. Activation analysis, emission spectroscopy, atomic absorption, x-ray fluorescence and various wet chemical methods contributed to the intercomparison. No result was received from mass spectroscopic methods and, although analyses were specifically encouraged, very few results were received on the organic components. From a first approximate evaluation a good agreement was found for Al, Fe, Zn, Mn, Ca, Pb, Cl, S, Si, Ti, Mn, while for the other elements no definite conclusion can yet be drawn. An attempt will be made to interpret important cases of systematic errors, a few of which are already evident

  11. Chemical and Microbiological Analysis of Certain Water Sources and Industrial Wastewater Samples in Dakahlia Governorate

    International Nuclear Information System (INIS)

    The chemical analysis included quantitative measurement of electrical conductivity, alkalinity , hardness sulphate, ph, total dissolved solids, chloride, as well as dissolved oxygen was carried out. The microbiological examination for different water sources and industrial wastewater samples was also conducted. some of heavy metals, Co2+ Cu2+ Fe3+ and Mn2+ were determined in fresh water, while other metals, such as Cr6+ , Co2+ , Zn2+ and Ni2+ were measured in industrial wastewater. Results of the chemical analysis showed that all measured parameters were found within the limitation either national or international law, except some samples which showed higher values than the permissible limits for some measured parameters. The microbiological analysis exhibited presence of yeasts, fungi and bacteria. Most bacterial isolates were short rod, spore formers as well as coccoid shaped bacteria. The efficiency of water treatment process on the reduction of microbial load was also calculated. Regarding the pathogenic bacteria, data showed that neither water samples nor industrial wastewater contain pathogens when using specific cultivation media for the examination. Furthermore, data proved the possibility of recycling of the tested industrial wastewater on which some microorganisms can grow. Data showed that the percent of heavy metals removal can reach to more than 70% in some cases as a result to bacterial treatment of industrial wastewater

  12. A new TXRF vacuum chamber with sample changer for chemical analysis using silicon drift chamber detector

    International Nuclear Information System (INIS)

    Full text: Several TXRF spectrometers for chemical analysis as well as for wafer surface analysis are commercially available. But there is no one available for chemical analysis offering the possibility to measure the samples in vacuum conditions. Vacuum of 10-2 mbar in the sample environment helps to reduce the background due to scattering from air, thus to improve the detection limits as well as to reduce the absorption of low energy fluorescence radiation from low Z elements and extend the elemental range to be measured and removes the Ar lines from the spectrum. The x-ray group of the Atominstitut designed and fabricated a new vacuum chamber for TXRF equipped with a 12 position sample changer from Italstructures, Riva, Italy. The detector used was a 10 mm2 silicon drift detector (KETEK, Munich, Germany), offering the advantage of electrically cooling, so no LN2 is required. The chamber was designed to be attached to a diffraction tube housing, e.g. with a fine focus Mo-x-ray tube and uses a multilayer monochromator. Spectra are stored by a small AMTEK MCA and control between sample changer and MCA communication is done by a modified AMPTEK software. The performance is expressed in detection limits of 1 pg Rb for Mo Ka excitation with 50 kV, 40 mA excitation conditions, 1000 s lifetime, obtained from a sample containing 600 pg Rb as single element standard. Details on performance, reproducibility and light element excitation and detection are presented. (author)

  13. Analysis of Thermal Desorption System for the Chemical Treatment of Old Storages of Oil Based Mud

    Directory of Open Access Journals (Sweden)

    Tanweer Hussain

    2013-04-01

    Full Text Available This paper presents an analysis for the chemical treatment of OBM (Oil Based Mud used in the drilling process in the oil and gas industry. The analysis is based on OBM stored at ENI (Italian National Energy gas fields at Bhit mount district Jamshoro since the last ten years that has been chemically and physically deteriorated. Characterization of various OBM samples was performed and these samples were processed in order to evaluate the best characteristics of the OBM for optimum treatment results. The OBM treatment process involves the separation of hazardous fluid (such as diesel or mineral oil from solids Due to the lean quality of the OBM, the dust separation process in the cyclone caused blockage in the cyclone. This paper suggests a remedial way by means of installation of a hammer stick in the cyclone dust collector to overcome cyclone blockage. The analysis is performed to compare the pressure drop and the dust collection efficiency in the cyclone with and without the hammer stick. The post-installation experimental results showed that hammer stick can improve the cyclone dust collection efficiency without blockage of the cyclone.

  14. Industrial Raman: providing easy, immediate, cost-effective chemical analysis anywhere

    Science.gov (United States)

    Farquharson, Stuart; Smith, Wayne W.; Carangelo, Robert M.; Brouillette, Carl R.

    1999-12-01

    During the past decade Raman spectroscopy has moved out of the shadow if IR spectroscopy and has become a routine laboratory tool for chemical analysis. This is largely due to the development of stable diode lasers, fiber optic samples probes, compact optical designs, high quantum efficiency detectors, and personal computers with fast electronics, and associated data acquisition and analysis. These developments allow real-time, multi-component chemical analysis, and suggest the use of Raman spectroscopy for process monitoring and control. Single-ended fiber optic proves simplify coupling into process streams, allow remote placement of the Raman instrument from the sample point, and give Raman spectroscopy a decided advantage over IR spectroscopy in industrial liquid and solid process applications. Indeed, more than a dozen new Raman instrument companies offering fiber optic based systems have been launched in the past five years. Notably, all of these systems employ charge coupled device detectors. And yet, only one company has successfully penetrated the industrial market. Instrument limitations cited include fluorescence interference, incomplete spectral coverage, wavelength reproducibility, and long-term instrument stability. To address these limitations, Real-Time Analyzers has developed a Fourier transform Raman instrument. It employs a diode pumped Nd:YAG laser with excitation at 1064 nm and a single element, uncooled InGaAs detector, that are integrated into On-Line Technologies' proven rugged, vibration and temperature immune interferometer. Instrument design and industrial applications will be presented.

  15. Neutron activation analysis applied to the chemical composition of metallic materials

    International Nuclear Information System (INIS)

    The physical properties of metallic materials, such as mechanical properties, corrosion resistance and others are determined by their chemical composition, which influences the various steps of the production process and the economic value attained by the materials. Instrumental neutron activation analysis was used in this work to evaluate the chemical composition of iron, steel, silicon and ferrosilicon reference materials. The concentration of the elements As, Co, Cr, Mn, Mo, Ni, V and W were analyzed in the iron and steel samples whereas As, Br, Co, Cr, K, Eu, Fe, La, Mn, Mo, Na, Nd, U, Th, Sb, Sc, Sm, Tb, V, W and Yb were determined in silicon and ferrosilicon samples. Accuracy was assessed comparing obtained results to reference materials certified values. Results of about 10 % were achieved for most of the elements. Precision was assessed by replicate measurements, and the results of about 10 % were also achieved. Accuracy and precision results showed that the technique is suitable for the metallic materials composition analysis. Interferences of Cr and Mn in V, Fe and Co in Mn; Co in Fe and Cr in Ti were quantified and only the last one was critical to the analysis of the materials employed in this work. (author)

  16. Comparing chemical analysis with literature studies to identify micropollutants in a catchment of Copenhagen (DK)

    DEFF Research Database (Denmark)

    Lützhøft, Hans-Christian Holten; Birch, Heidi; Eriksson, Eva;

    2011-01-01

    (EU, 2000). It is also required to establish inventories of sources to pollution, to design and perform monitoring programs as well as to outline strategies to reduce emissions if the environmental quality standards are exceeded. The aim of this study was to compare chemical analysis performed on...... urban surface runoff originating from a well defined catchment of Copenhagen (Denmark) with an inventory of potential pollution sources for the same catchment. The selected catchment covers an area with roads, a shopping centre, a parking lot, office buildings, a gymnasium and some restaurants. The...

  17. Tank 12H Acidic Chemical Cleaning Sample Analysis And Material Balance

    Energy Technology Data Exchange (ETDEWEB)

    Martino, C. J.; Reboul, S. H.; Wiersma, B. J.; Coleman, C. J.

    2013-11-08

    A process of Bulk Oxalic Acid (BOA) chemical cleaning was performed for Tank 12H during June and July of 2013 to remove all or a portion of the approximately 4400 gallon sludge heel. Three strikes of oxalic acid (nominally 4 wt % or 2 wt %) were used at 55 �C and tank volumes of 96- to 140-thousand gallons. This report details the sample analysis of a scrape sample taken prior to BOA cleaning and dip samples taken during BOA cleaning. It also documents a rudimentary material balance for the Tank 12H cleaning results.

  18. Model analysis of influences of the high-temperature reactor on location shifting in chemical industry

    International Nuclear Information System (INIS)

    An analysis is presented of the influences of High-Temperature Reactor on probable location shifting of big chemical plants, in the future. This is done by a spatial location model, that includes an investigation on 116 industrial locations within the first six countries of Common Market. The results of a computerized program show differences in location qualities when furnished either with traditional or with nuclear energy systems. In addition to location factor energy some other important factors, as subventions, taxes, labour, and transport costs are analysed, and their influence on industrial location is quantified. (orig.)

  19. Chemical composition analysis of ancient bricks and potteries by internal monostandard NAA

    International Nuclear Information System (INIS)

    The ko-based internal monostandard INAA (IM-INAA) method was used for the determination of major, minor and trace element concentrations in ancient bricks as well as potteries, collected from Buddhist (4th B.C. to 3rd A.D.) sites of in and around Vishakhapatnam district, Andhra Pradesh, India. Chemical composition analysis of these artifacts was carried out for the provenance study and also to find out possible correlations among the bricks and potteries. INAA is one of the best techniques used for the provenance study due to its advantageous properties like simultaneous multielement capability, negligible matrix effect, no spectral interference and inherent precision and accuracy

  20. Improved Method for the Flow Injection Analysis of Chemical Oxygen Demand Using Silver Nitrate

    OpenAIRE

    Korenaga, Takashi; Ikatsu, Hisayoshi; Moriwake, Tosio; Takahashi, Teruo

    1980-01-01

    On the flow injection analysis (FIA) of chemical oxygendemand (COD), silver salt was added as an oxidation catalyst for COD substances and a masking agent for halide to improve operating conditions of the FIA apparatus. Both of a proper concentration of potassium permanganate solution and 6.0 % sulfuric acid solution containing 0.1 % silver nitrate are individually pumped up with respective flow rates of 0.51 ml min(-l) and merged into a carrier stream. A 20 μ1 of sample solution is injected ...

  1. Recent developments in methods of chemical analysis in investigations of firearm-related events.

    Science.gov (United States)

    Zeichner, Arie

    2003-08-01

    A review of recent (approximately the last ten years) developments in the methods used for chemical analysis in investigations of firearm-related events is provided. This review discusses:examination of gunshot (primer) residues (GSR) and gunpowder (propellant) residues on suspects and their clothing;detection of firearm imprints on the hands of suspects;identification of the bullet entry holes and estimation of shooting distance;linking weapons and/or fired ammunition to the gunshot entries, and estimation of the time since discharge. PMID:12811451

  2. [Influence of ancient glass samples surface conditions on chemical composition analysis using portable XRF].

    Science.gov (United States)

    Liu, Song; Li, Qing-hui; Gan, Fu-xi

    2011-07-01

    Portable X-ray fluorescence analysis (PXRF) is one kind of surface analysis techniques, and the sample surface condition is an important factor that influences the quantitative analysis results. The ancient glass samples studied in the present paper were excavated from Xinjiang, Guangxi, Jiangsu provinces, and they belong to Na2O-CaO-SiO2, K2O-SiO2, and PbO-BaO-SiO2 system, respectively. Quantitative analysis results of weathered surface and inside of the ancient glass samples were compared. The concentration change of main fluxes in different parts of the samples was pointed out. Meanwhile, the authors studied the effect of distance between the sample and the reference plane, and curve shape of the sample on the quantitative results. The results obtained were calibrated by three methods, and the validity of these three methods was proved. Finally, the normalizing method was proved to be a better method for quantitative analysis of antiques. This paper also has guiding significance for chemical composition analysis of ancient jade samples using PXRF. PMID:21942060

  3. Standard test methods for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade plutonium metal

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2004-01-01

    1.1 These test methods cover procedures for the chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade plutonium metal to determine compliance with specifications.

  4. Study by factorial analysis of the influence of chemical composition on the stress corrosion cracking of austenitic stainless steels

    International Nuclear Information System (INIS)

    The stress corrosion cracking of austenitic stainless steels has been treated by factorial correspondence analysis. This statistical method gives a relationship between chemical characteristics and the susceptibility of the steels to the phenomenon

  5. Quantitative assessment of chemical artefacts produced by propionylation of histones prior to mass spectrometry analysis.

    Science.gov (United States)

    Soldi, Monica; Cuomo, Alessandro; Bonaldi, Tiziana

    2016-07-01

    Histone PTMs play a crucial role in regulating chromatin structure and function, with impact on gene expression. MS is nowadays widely applied to study histone PTMs systematically. Because histones are rich in arginine and lysine, classical shot-gun approaches based on trypsin digestion are typically not employed for histone modifications mapping. Instead, different protocols of chemical derivatization of lysines in combination with trypsin have been implemented to obtain "Arg-C like" digestion products that are more suitable for LC-MS/MS analysis. Although widespread, these strategies have been recently described to cause various side reactions that result in chemical modifications prone to be misinterpreted as native histone marks. These artefacts can also interfere with the quantification process, causing errors in histone PTMs profiling. The work of Paternoster V. et al. is a quantitative assessment of methyl-esterification and other side reactions occurring on histones after chemical derivatization of lysines with propionic anhydride [Proteomics 2016, 16, 2059-2063]. The authors estimate the effect of different solvents, incubation times, and pH on the extent of these side reactions. The results collected indicate that the replacement of methanol with isopropanol or ACN not only blocks methyl-esterification, but also significantly reduces other undesired unspecific reactions. Carefully titrating the pH after propionic anhydride addition is another way to keep methyl-esterification under control. Overall, the authors describe a set of experimental conditions that allow reducing the generation of various artefacts during histone propionylation. PMID:27373704

  6. Integrated 3D-printed reactionware for chemical synthesis and analysis.

    Science.gov (United States)

    Symes, Mark D; Kitson, Philip J; Yan, Jun; Richmond, Craig J; Cooper, Geoffrey J T; Bowman, Richard W; Vilbrandt, Turlif; Cronin, Leroy

    2012-05-01

    Three-dimensional (3D) printing has the potential to transform science and technology by creating bespoke, low-cost appliances that previously required dedicated facilities to make. An attractive, but unexplored, application is to use a 3D printer to initiate chemical reactions by printing the reagents directly into a 3D reactionware matrix, and so put reactionware design, construction and operation under digital control. Here, using a low-cost 3D printer and open-source design software we produced reactionware for organic and inorganic synthesis, which included printed-in catalysts and other architectures with printed-in components for electrochemical and spectroscopic analysis. This enabled reactions to be monitored in situ so that different reactionware architectures could be screened for their efficacy for a given process, with a digital feedback mechanism for device optimization. Furthermore, solely by modifying reactionware architecture, reaction outcomes can be altered. Taken together, this approach constitutes a relatively cheap, automated and reconfigurable chemical discovery platform that makes techniques from chemical engineering accessible to typical synthetic laboratories. PMID:22522253

  7. Chemical analysis of CH stars - II: atmospheric parameters and elemental abundances

    CERN Document Server

    Karinkuzhi, Drisya

    2014-01-01

    We present detailed chemical analyses for a sample of twelve stars selected from the CH star catalogue of Bartkevicius (1996). The sample includes two confirmed binaries, four objects that are known to show radial velocity variations and the rest with no information on the binary status. A primary objective is to examine if all these objects exhibit chemical abundances characteristics of CH stars, based on detailed chemical composition study using high resolution spectra. We have used high resolution (R ~ 42000) spectra from the ELODIE archive. These spectra cover 3900 to 6800 Angstrom in the wavelength range. We have estimated the stellar atmospheric parameters, the effective temperature Teff, the surface gravity log g, and metallicity [Fe/H] from LTE analysis using model atmospheres. Estimated temperatures of these objects cover a wide range from 4200 K to 6640 K, the surface gravity from 0.6 to 4.3 and metallicity from -0.13 to -1.5. We report updates on elemental abundances for several heavy elements, Sr,...

  8. Summer 2012 Testing and Analysis of the Chemical Mixture Methodology -- Part I

    Energy Technology Data Exchange (ETDEWEB)

    Glantz, Clifford S.; Yu, Xiao-Ying; Coggin, Rebekah L.; Ponder, Lashaundra A.; Booth, Alexander E.; Petrocchi, Achille J.; Horn, Sarah M.; Yao, Juan

    2012-07-01

    This report presents the key findings made by the Chemical Mixture Methodology (CMM) project team during the first stage of their summer 2012 testing and analysis of the CMM. The study focused on answering the following questions: o What is the percentage of the chemicals in the CMM Rev 27 database associated with each Health Code Number (HCN)? How does this result influence the relative importance of acute HCNs and chronic HCNs in the CMM data set? o What is the benefit of using the HCN-based approach? Which Modes of Action and Target Organ Effects tend to be important in determining the HCN-based Hazard Index (HI) for a chemical mixture? o What are some of the potential issues associated with the current HCN-based approach? What are the opportunities for improving the performance and/or technical defensibility of the HCN-based approach? How would those improvements increase the benefit of using the HCN-based approach? o What is the Target Organ System Effect approach and how can it be used to improve upon the current HCN-based approach? How does the benefits users would derive from using the Target Organ System Approach compare to the benefits available from the current HCN-based approach?

  9. Chemical non-equilibrium flow analysis of H2 fueled scramjet nozzle

    Directory of Open Access Journals (Sweden)

    Yue Huang

    2015-03-01

    Full Text Available A numerical analysis of the chemical non-equilibrium phenomena in a scramjet nozzle has been performed using CHEMKIN software. Different operating conditions of the Hyshot scramjet nozzle were simulated and analyzed. Three chemical status, frozen flow, equilibrium flow, and non-equilibrium flow, were tested and compared to demonstrate the chemical reaction effect on nozzle flow field. The real non-equilibrium flow simulation result is between those of the two limiting cases: frozen flow and equilibrium flow, and is closer to that of frozen flow. With complete combustion condition at nozzle inlet, the radical recombination reaction releases tremendous amount of heat and this heat is mainly used to increases gas temperature and has only slight increasing effect on thrust. With incomplete combustion condition at nozzle inlet, both combustion reaction and radical recombination occur in the nozzle, the effect of reaction heat release on thrust depends on the degree of combustion completeness at nozzle inlet, it could increase thrust tremendously compared to frozen flow.

  10. CHEMKIN-III: A FORTRAN chemical kinetics package for the analysis of gas-phase chemical and plasma kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Kee, R.J.; Rupley, F.M.; Meeks, E.; Miller, J.A.

    1996-05-01

    This document is the user`s manual for the third-generation CHEMKIN package. CHEMKIN is a software package whose purpose is to facilitate the formation, solution, and interpretation of problems involving elementary gas-phase chemical kinetics. It provides a flexible and powerful tool for incorporating complex chemical kinetics into simulations of fluid dynamics. The package consists of two major software components: an Interpreter and a Gas-Phase Subroutine Library. The Interpreter is a program that reads a symbolic description of an elementary, user-specified chemical reaction mechanism. One output from the Interpreter is a data file that forms a link to the Gas-Phase Subroutine Library. This library is a collection of about 100 highly modular FORTRAN subroutines that may be called to return information on equations of state, thermodynamic properties, and chemical production rates. CHEMKIN-III includes capabilities for treating multi-fluid plasma systems, that are not in thermal equilibrium. These new capabilities allow researchers to describe chemistry systems that are characterized by more than one temperature, in which reactions may depend on temperatures associated with different species; i.e. reactions may be driven by collisions with electrons, ions, or charge-neutral species. These new features have been implemented in such a way as to require little or no changes to CHEMKIN implementation for systems in thermal equilibrium, where all species share the same gas temperature. CHEMKIN-III now has the capability to handle weakly ionized plasma chemistry, especially for application related to advanced semiconductor processing.

  11. Development of a chemical structure comparison method for integrated analysis of chemical and genomic information in the metabolic pathways.

    Science.gov (United States)

    Hattori, Masahiro; Okuno, Yasushi; Goto, Susumu; Kanehisa, Minoru

    2003-10-01

    Cellular functions result from intricate networks of molecular interactions, which involve not only proteins and nucleic acids but also small chemical compounds. Here we present an efficient algorithm for comparing two chemical structures of compounds, where the chemical structure is treated as a graph consisting of atoms as nodes and covalent bonds as edges. On the basis of the concept of functional groups, 68 atom types (node types) are defined for carbon, nitrogen, oxygen, and other atomic species with different environments, which has enabled detection of biochemically meaningful features. Maximal common subgraphs of two graphs can be found by searching for maximal cliques in the association graph, and we have introduced heuristics to accelerate the clique finding and to detect optimal local matches (simply connected common subgraphs). Our procedure was applied to the comparison and clustering of 9383 compounds, mostly metabolic compounds, in the KEGG/LIGAND database. The largest clusters of similar compounds were related to carbohydrates, and the clusters corresponded well to the categorization of pathways as represented by the KEGG pathway map numbers. When each pathway map was examined in more detail, finer clusters could be identified corresponding to subpathways or pathway modules containing continuous sets of reaction steps. Furthermore, it was found that the pathway modules identified by similar compound structures sometimes overlap with the pathway modules identified by genomic contexts, namely, by operon structures of enzyme genes. PMID:14505407

  12. Thermodynamic analysis of a combined chemical looping-based trigeneration system

    International Nuclear Information System (INIS)

    Highlights: • A conceptual zero emission trigeneration plant is developed. • Energy and exergy based performance analysis is performed. • The optimum system performances are specified with parametric and case studies. • The plant energy and exergy efficiencies are 56.9% and 45.05%, respectively. - Abstract: Energy and exergy analyses of a newly developed three-reactor chemical looping hydrogen generation process are performed for trigeneration of power, hydrogen, and heating. The present integrated system consists of an (a) air separation unit (ASU), (b) gasification sub-system, (c) chemical looping hydrogen generation unit in connection with SOFC assisted gas turbine (CLHG-SOFC/GT), (d) an extended heat recovery steam generation unit (HRSG) to supply heat for Steam cycle, organic Rankine cycle and space heating, (e) a two stage steam Rankine cycle (SRC) for power generation with reheat and regeneration, and (f) an organic Rankine cycle (ORC) to produce power. The gasified coal is separated and purified in quench chamber and syngas cleaner; CO2 and H2 are generated from fuel and steam reactors of chemical looping unit, and both are then compressed after separated from water and ready for transportation. A specified amount of H2 produced from steam reactor is also used to produce electricity with SOFC/GT. A comprehensive parametric study is performed, and the effects of multi-generation and system integration, environmental conditions, and system parameter variations on overall efficiencies are investigated. Overall electrical, hydrogen, energy and exergy efficiencies are comparatively determined for different cases. Overall energy and exergy efficiencies of proposed system are found to be 56.9% and 45.05%, respectively, with a total exergy destruction rate of 15,421 kW. The highest exergy destruction occurs in the gasifier and CLHG due to high temperature chemical processes

  13. Chemical Analysis of the Herbal Medicine Salviae miltiorrhizae Radix et Rhizoma (Danshen

    Directory of Open Access Journals (Sweden)

    Hanqing Pang

    2016-01-01

    Full Text Available Radix Salviae miltiorrhizae et Rhizoma, known as Danshen in China, is one of the most popular traditional Chinese medicines. Recently, there has been increasing scientific attention on Danshen for its remarkable bioactivities, such as promoting blood circulation, removing blood stasis, and clearing away heat. This review summarized the advances in chemical analysis of Danshen and its preparations since 2009. Representative established methods were reviewed, including spectroscopy, thin layer chromatography, gas chromatography, liquid chromatography (LC, liquid chromatography-mass spectrometry (LC-MS, capillary electrophoresis, electrochemistry, and bioanalysis. Especially the analysis of polysaccharides in Danshen was discussed for the first time. Some proposals were also put forward to benefit quality control of Danshen.

  14. Design of sustainable chemical processes: Systematic retrofit analysis, generation and evaluation alternatives

    DEFF Research Database (Denmark)

    Carvalho, Ana; Gani, Rafiqul; Matos, Henrique

    2008-01-01

    The objective of this paper is to present a generic and systematic methodology for identifying the feasible retrofit design alternatives of any chemical process. The methodology determines a set of mass and energy indicators from steady-state process data, establishes the operational and design...... targets, and through a sensitivity-based analysis, identifies the design alternatives that can match a set of design targets. The significance of this indicator-based method is that it is able to identify alternatives, where one or more performance criteria (factors) move in the same direction thereby...... eliminating the need to identify trade-off-based solutions. These indicators are also able to reduce (where feasible) a set of safety indicators. An indicator sensitivity analysis algorithm has been added to the methodology to define design targets and to generate sustainable process alternatives. A computer...

  15. Application of Image Analysis Based on SEM and Chemical Mapping on PC Mortars under Sulfate Attack

    Institute of Scientific and Technical Information of China (English)

    YU Cheng; SUN Wei; Scrivener Karen

    2014-01-01

    The degradation mechanisms of cementitious materials exposed to sulfate solutions have been controversial, despite considerable research. In this paper, two methodologies of image analysis based on scanning electron microscope and chemical mapping are used to analyse Portland cement mortars exposed to sodium sulfate solution. The effects of sulfate concentration in solution and water to cement ratio of mortar, which are considered as the most sensitive factors to sulfate attack, are investigated respectively by comparing the macro expansion with microstructure analysis. It is found that the sulfate concentration in pore solution, expressed as sulfate content in C-S-H, plays a critical role on the supersaturation with respect to ettringite and so on the expansion force generated.

  16. Advances in explosives analysis--part I: animal, chemical, ion, and mechanical methods.

    Science.gov (United States)

    Brown, Kathryn E; Greenfield, Margo T; McGrane, Shawn D; Moore, David S

    2016-01-01

    The number and capability of explosives detection and analysis methods have increased substantially since the publication of the Analytical and Bioanalytical Chemistry special issue devoted to Explosives Analysis (Moore and Goodpaster, Anal Bioanal Chem 395(2):245-246, 2009). Here we review and critically evaluate the latest (the past five years) important advances in explosives detection, with details of the improvements over previous methods, and suggest possible avenues towards further advances in, e.g., stand-off distance, detection limit, selectivity, and penetration through camouflage or packaging. The review consists of two parts. This part, Part I, reviews methods based on animals, chemicals (including colorimetry, molecularly imprinted polymers, electrochemistry, and immunochemistry), ions (both ion-mobility spectrometry and mass spectrometry), and mechanical devices. Part II will review methods based on photons, from very energetic photons including X-rays and gamma rays down to the terahertz range, and neutrons. PMID:26462922

  17. Standard test methods for chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade boron carbide

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2004-01-01

    1.1 These test methods cover procedures for the chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade boron carbide powder and pellets to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Total Carbon by Combustion and Gravimetry 7-17 Total Boron by Titrimetry 18-28 Isotopic Composition by Mass Spectrometry 29-38 Chloride and Fluoride Separation by Pyrohydrolysis 39-45 Chloride by Constant-Current Coulometry 46-54 Fluoride by Ion-Selective Electrode 55-63 Water by Constant-Voltage Coulometry 64-72 Impurities by Spectrochemical Analysis 73-81 Soluble Boron by Titrimetry 82-95 Soluble Carbon by a Manometric Measurement 96-105 Metallic Impurities by a Direct Reader Spectrometric Method 106-114

  18. Chemical characterization of diets consumed in the COSEAS restaurant, by neutron activation analysis

    International Nuclear Information System (INIS)

    This study presents the results of chemical characterization of meals (lunch) offered by COSEAS/USP-SP restaurant, during 5 non consecutive days. These meals were collected in triplicate, in the same way they are offered to the users, being freeze-dried and prepared for chemical analysis. In the total, 15 samples were collected. The proximate composition was determined by using the standard methodologies according to AOAC (1995). The contents of some micronutrients (Ca, Fe, K, Na, Se and Zn) were determined by instrumental neutron activation analysis. The methodology validation was performed by certified reference materials analyses: Oyster Tissue (NIST SRM 1566b), Orchard Leaves (NIST SRM 1541) and Peach Leaves (NIST SRM 1547). >From concentration results the daily intake of each micronutrient was calculated considering this meal as 40% of the total daily intake and the values were compared to the new dietary recommendations of micronutrients (Dietary Reference Intakes-DRIs, Institute of Medicine, USA), for the women in the life stage from 19 to 30 years. Comparing the average values found with the recommended values, it was verified that macronutrients and Fe, Se and Zn micronutrients reached the values set by new DRIs. For Ca and K the daily intake was inadequate and Na, exceeded the recommended value. (author)

  19. Isolation and chemical analysis of nanoparticles from English ivy (Hedera helix L.)

    Energy Technology Data Exchange (ETDEWEB)

    Lenaghan, Scott C [University of Tennessee, Knoxville (UTK); Burris, Jason N [ORNL; Chourey, Karuna [ORNL; Huang, Yujian [University of Tennessee, Knoxville (UTK); Lady, Belinda [University of Tennessee, Knoxville (UTK); Sharma, Ritin [ORNL; Pan, Chongle [ORNL; Lejeune, Zorabel M [ORNL; Foister, Shane [ORNL; Hettich, Robert {Bob} L [ORNL; StewartJr., C neal [University of Tennessee, Knoxville (UTK); Zhang, Mingjun [ORNL

    2013-01-01

    It was discovered that adventitious roots of English ivy secreted a high strength adhesive containing uniform nanoparticles. These nanoparticles were hypothesized to be organic in nature. Subsequent studies have revealed several applications for these nanoparticles, but their chemical composition remained unknown. Here, we describe an isolation procedure to obtain gram quantities of ivy nanoparticles from adventitious roots. In addition, ultraviolet/visible (UV/Vis) spectroscopy, inductively coupled plasma mass spectrometry (ICP-MS), elemental analysis, fourier transform infrared spectroscopy (FTIR), and gel electrophoresis were conducted to identify the chemical nature of the ivy nanoparticles. Based on this comprehensive analysis, we conclude that the ivy nanoparticles are proteinaceous consisting of 51.77% carbon, 4.72% nitrogen, and 0.32% sulfur, without the presence of metals. Liquid chromatography tandem mass spectrometry (LC-MS/MS) based protein profiling revealed the presence of at least 6 proteins, including heat shock proteins and other large molecular weight proteins. Identification of these protein candidates will facilitate gene discovery and bioproduction of ivy nanoparticles.

  20. Characterization of Maturity Level in Laying Hen Manure by Chemical and Thermogravimetric Analysis

    Directory of Open Access Journals (Sweden)

    Alice Dall’Ara

    2008-01-01

    Full Text Available This study aims at investigating maturity levels in manure from laying hens in order to encourage its agronomic re-utilization. In fact the use of unstable/insufficiently mature manure could potentially damage both soils and crops. Effective, easy to reproduce methods are needed in order to assess bio-stabilisation and maturity levels, particularly for biomass that has not undergone conventional composting. This study compares samples of caged, laying hen manure, an organic matter rich in nutrients, N and P and devoid of litter or bulking agents, at different levels of maturation. Both chemical (dry matter, ashes, carbon and its fractioning, total and ammoniacal nitrogen and physical methods, such as thermogravimetry, were used to characterize them. Such physical methods do introduce any sample modification and shorten the analysis time. From a statistical point of view, chemical methods are effective only in distinguishing among different drying methods connected with manure management systems. Only thermogravimetric analysis can identify mature samples by means of total mass loss in the range RT- 900°C, mass loss in the range 350-425°C and energy release at 500°C. In addition, thermogravimetric profiles could be used to define a fingerprint for this kind of biomass.

  1. High-throughput peptide mass fingerprinting and protein macroarray analysis using chemical printing strategies

    International Nuclear Information System (INIS)

    We describe a 'chemical printer' that uses piezoelectric pulsing for rapid and accurate microdispensing of picolitre volumes of fluid for proteomic analysis of 'protein macroarrays'. Unlike positive transfer and pin transfer systems, our printer dispenses fluid in a non-contact process that ensures that the fluid source cannot be contaminated by substrate during a printing event. We demonstrate automated delivery of enzyme and matrix solutions for on-membrane protein digestion and subsequent peptide mass fingerprinting (pmf) analysis directly from the membrane surface using matrix-assisted laser-desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). This approach bypasses the more commonly used multi-step procedures, thereby permitting a more rapid procedure for protein identification. We also highlight the advantage of printing different chemistries onto an individual protein spot for multiple microscale analyses. This ability is particularly useful when detailed characterisation of rare and valuable sample is required. Using a combination of PNGase F and trypsin we have mapped sites of N-glycosylation using on-membrane digestion strategies. We also demonstrate the ability to print multiple serum samples in a micro-ELISA format and rapidly screen a protein macroarray of human blood plasma for pathogen-derived antigens. We anticipate that the 'chemical printer' will be a major component of proteomic platforms for high-throughput protein identification and characterisation with widespread applications in biomedical and diagnostic discovery

  2. Refractometry and interferometry in chemical analysis; Refractometrie et interferometrie en analyse chimique

    Energy Technology Data Exchange (ETDEWEB)

    Veret, C. [Faculte des Sciences de Paris, 75 (France)

    2000-03-01

    In vacuum, an electromagnetic radiation is propagated at a constant velocity. But, when it has to pass through a physical medium, it is submitted to different interactions (for instance: absorption, diffusion, refraction, polarization, dispersion, fluorescence) which lead to a modification of its propagation. In the frequency ranges of the radiation for which the absorption is not very important, the modifications of the propagation velocity of a radiation can bring data on the nature and/or the physical conditions (pressure, temperature) of a medium, whatever its state be: gas, liquid or solid. Thus, the absolute refractive index of a medium in relation to vacuum is defined as the ratio c/v of the propagation velocity c of a monochromatic electromagnetic radiation in vacuum at its velocity v in this medium. The photonic refractometry (field of ultraviolet, visible and infrared radiations) is the set of the measure techniques of the refractive indexes having a role in chemical analysis. The refractometry measures can only be applied to media which are optically transparent. After having described these techniques, the author presents their uses in chemical analysis. (O.M.)

  3. PHYSICO-CHEMICAL ANALYSIS OF SELECTED GROUND WATER SAMPLES OF RURAL AREAS OF JAIPUR, RAJASTHAN

    Directory of Open Access Journals (Sweden)

    Priyanka Dhingra

    2014-12-01

    Full Text Available The aim of present study was to assess the status of the groundwater in rural areas of Jaipur city. People on globe are under tremendous threat due to undesired changes in the physical, chemical and biological characteristics of air, water and soil. Due to increased population, urbanization, industrialization, use of fertilizers water is highly polluted with different harmful contaminants Natural water resources are being contaminated due to weathering of rocks and leaching of soil, mining processing etc. It is necessary that quality of drinking water should be checked at regular time interval to prevent various water born diseases. In present analysis physico-chemical parameter of drinking water viz. pH, hardness, TDS, residual chlorine, dissolved oxygen, electrical conductivity, Free CO2 have been analyzed. Drinking water quality of 8 villages of Amber District Jaipur, Rajasthan was analyzed to identify the nature and quality of water. The drinking water samples were collected in clean polythene one liter cans and subjected for analysis in laboratory. The main objective of the present paper is to aware people of concerned area about the water quality and concerned health hazards.

  4. Chemical investigation, isolation and structural analysis of flavones from primula veris

    International Nuclear Information System (INIS)

    The chemical investigation, isolation and structural analysis of six flavones present in flowers of Primula veris is described. Sample preparation of substances G from Primula veris comprised methanol extraction, low pressure chromatography on aluminum oxide, medium pressure chromatography on silica gel, and RP-HPLC on ODS. The six flavones, which were identified by their blue fluorescence after separation by thin layer chromatography, were named substance G1, G2, G3, G4, G5 and G6 according to their Rf-values. Fractions were collected during each of the separation processes and the fractions were analyzed by NP-HPLC and RP-HPLC. Higher resolution was obtained by NP-HPLC on a silica gel column and an n-hexane/ isopropanol (92:8 v/v) eluent, where 6 peaks (G1, G2, G3, G4, G5 and G6) were obtained. Diode array detection from 190 - 350 nm was utilized for the recording of UV-spectra for peak identification and peak-purity-analysis. The structures of Substance G4 and Substance G6 were established on the basis of UV, NMR, EI-MS and APCI-MS. The structure of the isolated substance G4 was verified by chemical synthesis. (author)

  5. Quantum chemical computations, vibrational spectroscopic analysis and antimicrobial studies of 2,3-Pyrazinedicarboxylic acid.

    Science.gov (United States)

    Beaula, T Joselin; Packiavathi, A; Manimaran, D; Joe, I Hubert; Rastogi, V K; Jothy, V Bena

    2015-03-01

    Density Functional Theory (DFT) calculations at B3PW91 level with 6-311G (d) basis sets were carried out for 2,3-Pyrazinedicarboxylic acid (PDCA) to analyze in detail the equilibrium geometries and vibrational spectra. Calculations reveal that the optimized geometry closely resembles the experimental XRD data. Vibrational spectra were analyzed on the basis of potential energy distribution (PED) of each vibrational mode, which provides quantitative as well as qualitative interpretation of IR and Raman spectra. Information about size, shape, charge density distribution and site of chemical reactivity of the molecule were obtained by mapping electron density isosurface with the electrostatic potential surface (ESP). Based on optimized ground state geometries, NBO analysis was performed to study donor-acceptor (bond-antibond) interactions. TD-DFT analysis was also performed to calculate energies, oscillator strength of electronic singlet-singlet transitions and the absorption wavelengths. The (13)C and (1)H nuclear magnetic resonance (NMR) chemical shifts of the molecule in the ground state were calculated by gauge independent atomic orbital (GIAO) method and compared with the experimental values. PDCA was screened for its antimicrobial activity and found to exhibit antifungal and antibacterial effects. Molecular docking was also performed for the different receptors. PMID:25544188

  6. Risk analysis in the chemical industry; Analisis de riesgos en la industria quimica

    Energy Technology Data Exchange (ETDEWEB)

    Rea Soto, Rogelio; Sandoval Valenzuela, Salvador [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    2000-07-01

    The Instituto de Investigaciones Electricas has a group of risk analysis (GAR), specialized in the most advanced methodologies to apply them in diverse industries of the productive sector, such as the nuclear, the oil and the chemical industries. In this work the integrated methodology that the GAR uses to make risk analysis in the chemical and oil industries is described. These analyses have as an objective to make a meticulous evaluation of the system design, the operation practices, the maintenance and inspection policies and the emergency plans. [Spanish] El Instituto de Investigaciones Electricas cuenta con un grupo de analisis de riesgo (GAR), especializado en las metodologias mas avanzadas para aplicarlas en diversas industrias del sector productivo, como lo son la nuclear, la petrolera y la quimica. En este trabajo se describe la metodologia integrada que el GAR utiliza para realizar analisis de riesgos en las industrias quimica y petrolera. Estos analisis tienen como objetivo realizar una minuciosa evaluacion del diseno del sistema, las practicas de operacion, las politicas de mantenimiento e inspeccion y los planes de emergencia.

  7. Conventional and dynamic safety analysis: Comparison on a chemical batch reactor

    International Nuclear Information System (INIS)

    Dynamic safety analysis methodologies are an attractive approach to tackle systems with complex dynamics (i.e. with behavior highly dependent on the values of the process parameters): this is often the case in various areas of the chemical industry. The present paper compares analyses with Probabilistic Safety Assessment (PSA)/Quantitative Risk Assessment (QRA) methods with those from a dynamic methodology (Monte Carlo simulation). The results of a case study for a chemical batch reactor from the literature, overall risk figure and main contributors, are examined. The comparison has shown that, provided that the event success criteria are appropriately defined, consistent results can be obtained; otherwise important accident scenarios, identifiable by the dynamic Monte Carlo simulation, are possibly missed in the application of conventional methods. Defining such criteria was quite resource-intensive: for the analysis of this small system, the success criteria definitions required many system simulation runs (about 1000). Such large numbers of runs may not be practical in industrial-scale applications. It is shown that success criteria obtained with fewer simulation runs could have led to different quantitative PSA results and to the omission of important accident scenario variants.

  8. Chemical study of sediments from Solimoes and Negro rivers by Instrumental Neutron Activation Analysis (INAA)

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Jose O. dos [Coordenacao de Cursos Tecnicos e Superiores. Instituto Federal de Educacao, Ciencia e Tecnologia de Sergipe, Lagarto, SE (Brazil); Munita, Casimiro S., E-mail: camunita@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Soares, Emilio A.A., E-mail: easores@ufam.edu.br [Departamento de Geociencias. Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil)

    2011-07-01

    The events of the last 70,000 yrs of the history of the Solimoes-Amazon river system are recorded in the fluvial terraces at region of confluence of the Negro and Solimoes rivers, and are markers of changes in the landscape of the Amazon region and it can be observed by analyzing the sedimentary deposits quaternary in Amazon fluvial system. The aim of this work was to contribute with the characterization sedimentological - stratigraphic of Pleistocene succession of the confluence zone of the Negro and Solimoes rivers by means of elemental chemical analysis. To provenance study, 24 elements were determined by Instrumental Neutron Activation Analysis from sediment samples collected at confluence of Negro and Solimoes rivers and the results were interpreted using cluster and linear discriminant analysis, which classification to priori were samples previously defined according to Pleistocene stratigraphic units individualized at study area. According to discriminant analysis, one can infer that samples from the basin of the Solimoes River and Parana do Ariau grabens (GPA) are not significantly different, but there was a clear separation of sediments from Negro and GPA groups. It was also obtained that samples from highest and lowest terraces that the of the Solimoes river and Parana do Ariau are different, suggesting that it is a process that reflects the influence of chemical weathering on the uppermost terrace deposits. Thus, this work contributes to determine the contribution of the sediments deposited by the Solimoes and Negro rivers in the filling of tectonic depressions and in the variations of degree of weathering between younger and older units, and provides additional subsidies to build the geological evolution of the area. (author)

  9. Chemical and physical analysis on hard tissues after irradiation with short pulse Nd:YAG laser

    International Nuclear Information System (INIS)

    This work reports on a study that was designed to investigate chemical, physical and morphological alterations in the dental enamel surface. The influence of application of laser in enamel surface by microscopic technical, X-ray fluorescence for chemical analysis, physical property as well as hardness and thermal analysis with Nd:YAG laser is also pointed out. A prototype of Nd:YAG (Q-switched) laser developed at the Center of Lasers and Applications - Institute of Energetic and Nuclear Research, aiming applications in the Medical Sciences that typical wavelength of 1.064 nm was used. The modifications in human dental enamel chemical composition for major and trace elements are here outlined. The accuracy of procedures was performed by analysis of natural hydroxyapatite as standard reference material. The identification and quantification of the chemical elements presented in the dental tissue samples were performed trough EDS, XRF and INAA. We determined the rate Calcium/Phosphorus (Ca/P) for different techniques. We performed an analysis in different regions of the surface and for different areas allowing a description of the chemical change in the total area of the specimen and the assessment of the compositional homogeneity of the each specimen. A comparison between XRF and INAA is presented. Based on morphological analysis of the irradiated surfaces with short pulse Nd:YAG laser we determined the area surrounded by the irradiation for the parameters for this thesis, and this technique allowed us to visualize the regions of fusion and re-solidification. The energy densities ranged from 10 J/cm2 to 40 J/cm2, with pulse width of 6, 10 e 200 ns, and repetition rates of 5 and 7 Hz. In this thesis, FTIR-spectroscopy is used to analyze powder of mineralized tissue as well as enamel, dentine, root and cementum for human and bovine teeth after irradiation with short-pulse Nd:YAG laser. Characteristic spectra were obtained for the proteins components and mineral

  10. Thermal Analysis and Investigation of NiO-Based Oxygen Carriers for Chemical-Looping Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Jerndal, Erik, e-mail: erik.jerndal@chalmers.se

    2009-03-15

    Capture and storage of CO{sub 2} can be used to reduce greenhouse gas emissions from combustion of fossil fuels. Chemical-looping combustion is a two-step combustion process where CO{sub 2} is obtained in a separate stream, ready for compression and storage. The technology uses circulating oxygen carriers to transfer oxygen from an air reactor to a fuel reactor, thus avoiding an energy consuming gas separation unit. A thermal analysis of the process using a large number of possible oxygen carriers was performed by simulating chemical reactions. Based on the ability of the oxygen carriers to convert different gaseous fuels, stability in air and melting temperature some metal oxides based on Ni, Cu, Fe, Mn, Co, W and sulphates of Ba, Sr and Ca showed good thermodynamic properties and could be feasible as oxygen carriers. The promising systems were investigated further with respect to temperature changes in the fuel reactor as well as possible formation of carbon, sulphides and sulphates which may deactivate the oxygen carriers. Oxygen carriers of NiO, supported by NiAl{sub 2}O{sub 4}, were prepared and investigated experimentally with respect to parameters important for chemical-looping combustion. These oxygen carriers were based on commercially available raw materials in contrast to most of the previously tested oxygen carriers, which have been prepared from pure chemicals. Further, it was investigated if spray-drying, which is a production method suitable for large-scale particle preparation, can be used to produce high performing oxygen carriers instead of the small-scale freeze-granulation method. Generally, materials prepared from commercially available raw material showed high reactivity with methane and oxygen. Oxygen carriers prepared by spray-drying, displayed a remarkable similarity when compared to oxygen carriers prepared from the same starting material by freeze-granulation, both regarding physical properties and reactivity. Further, the up-scaling of

  11. Analysis of exergy loss of gasoline surrogate combustion process based on detailed chemical kinetics

    International Nuclear Information System (INIS)

    Highlights: • We explored the exergy loss sources of gasoline engine like combustion process. • The model combined non-equilibrium thermodynamics with detailed chemical kinetics. • We explored effects of initial conditions on exergy loss of combustion process. • Exergy loss decreases 15% of fuel chemical exergy by design of initial conditions. • Correspondingly, the second law efficiency increases from 38.9% to 68.9%. - Abstract: Chemical reaction is the most important source of combustion irreversibility in premixed conditions, but details of the exergy loss mechanisms have not been explored yet. In this study numerical analysis based on non-equilibrium thermodynamics combined with detailed chemical kinetics is conducted to explore the exergy loss mechanism of gasoline engine like combustion process which is simplified as constant volume combustion. The fuel is represented by the common accepted gasoline surrogates which consist of four components: iso-octane (57%), n-heptane (16%), toluene (23%), and 2-pentene (4%). We find that overall exergy loss is mainly composed of three peaks along combustion generated from chemical reactions in three stages, the conversion from large fuel molecules into small molecules (as Stage 1), the H2O2 loop-related reactions (as Stage 2), and the violent oxidation reactions of CO, H, and O (as Stage 3). The effects of individual combustion boundaries, including temperature, pressure, equivalence ratio, oxygen concentration, on combustion exergy loss have been widely investigated. The combined effects of combustion boundaries on the total loss of gasoline surrogates are also investigated. We find that in a gasoline engine with a compression ratio of 10, the total loss can be reduced from 31.3% to 24.3% using lean combustion. The total loss can be further reduced to 22.4% by introducing exhaust gas recirculation and boosting the inlet charge. If the compression ratio is increased to 17, the total loss can be decreased to 20

  12. Two-dimensional dopant analysis in silicon using chemical etching and transmission electron microscopy

    Science.gov (United States)

    Neogi, Suneeta Shamanna

    The purpose of this research has been to develop a methodologoy to map two-dimensional dopant distributions in silicon and investigate the factors that influence the interpretation of the results. The analysis exploits the image contrast obtained by transmission electron microscopy (TEM) using cross-section specimens which have undergone selective chemical etching. The appearance of iso-thickness contours in a selectively etched TEM sample must represent iso-concentration contours when imaged under constant diffraction conditions. The application of this technique is two-fold: (1) to establish a physical metrology of semiconductor devices for the purpose of research and development efforts that impact on future nodes outlined in the semiconductor roadmap and (2) to provide physical data for validation of simulation tools in technology computer aided design (TCAD). The research involves an investigation into the selective removal of doped regions for both test and device structures, followed by an analysis to obtain two-dimensional (2-D) dopant profiles. The critical issues which arise in the development of a methodology to profile dopant distributions and which are addressed in this investigation are, wedge technique versus conventional dimple and ion-mill procedures for thin-film preparation, thin-film versus bulk chemical etching, data acquisition using TEM and choice of diffraction conditions, sensitivity in terms of the etch detection limit, resolution influenced by the effective extinction length of the operating reflection, digital image processing to extract profiles from thickness contours, calibration of the 2-D profiles using a one-dimensional (1-D) calibrator and role of structure/dopant interactions such as stress, interfaces and point defects in test structures and real device structures containing additional processing sequences. Selective chemical etching in combination with TEM has the sensitivity, resolution and reproducibility required to be used

  13. Development of a mass spectrometry sampling probe for chemical analysis in surgical and endoscopic procedures.

    Science.gov (United States)

    Chen, Chien-Hsun; Lin, Ziqing; Garimella, Sandilya; Zheng, Lingxing; Shi, Riyi; Cooks, R Graham; Ouyang, Zheng

    2013-12-17

    A sampling probe based on ambient desorption ionization was designed for in vivo chemical analysis by mass spectrometry in surgical and endoscopic procedures. Sampling ionization of analytes directly from tissue was achieved by sealing the sampling tip against the tissue surface without allowing leakage of the auxiliary gas used for desorption ionization. The desorbed charged species were transferred over a long distance (up to 4 m) through a flexible tube of internal diameter as small as 1/16 in. to the inlet of the mass spectrometer used for analysis. The conditions used for desorption electrospray ionization (DESI) were optimized to achieve biocompatibility for clinical applications while obtaining adequate efficiency for the analysis. This optimization involved the removal of high voltage and use of pure water as a spray solvent instead of the organic solvents or aqueous mixtures normally used. Improved sensitivity was achieved under these conditions by increasing the gas flow rate in the transfer tube. The destructive effect on tissue surfaces associated with typical desorption ionization was avoided by altering the local gas dynamics in the sample area without compromising the overall analysis efficiency. PMID:24251679

  14. RETRAN code analysis of Tsuruga-2 plant chemical volume control system (CVCS) reactor coolant leakage incident

    International Nuclear Information System (INIS)

    In the Chemical Volume Control System (CVCS) reactor primary coolant leakage incident, which occurred in Tsuruga-2 (4-loop PWR, 3,423 MWt, 1,160 MWe) on July 12, 1999, it took about 14 hours before the leakage isolation. The delayed leakage isolation and a large amount of leakage have become a social concern. Effective procedure modification was studied. Three betterments were proposed based on a qualitative analysis to reduce the pressure and temperature of the primary loop as fast as possible by the current plant facilities while maintaining enough subcooling of the primary loop. I analyzed the incident with RETRAN code in order to quantitatively evaluate the leakage reduction when these betterments are adopted. This paper is very new because it created a typical analysis method for PWR plant behavior during plant shutdown procedure which conventional RETRAN transient analyses rarely dealt with. Also the event time is very long. To carry out this analysis successfully, I devised new models such as an Residual Heat Removal System (RHR) model etc. and simplified parts of the conventional model. Based on the analysis results, I confirmed that leakage can be reduced by about 30% by adopting these betterments. Then the Japan Atomic Power Company (JAPC) modified the operational procedure for reactor primary coolant leakage events adopting these betterments. (author)

  15. Miniature near-infrared spectrometer for point-of-use chemical analysis

    Science.gov (United States)

    Friedrich, Donald M.; Hulse, Charles A.; von Gunten, Marc; Williamson, Eric P.; Pederson, Christopher G.; O'Brien, Nada A.

    2014-03-01

    Point-of-use chemical analysis holds tremendous promise for a number of industries, including agriculture, recycling, pharmaceuticals and homeland security. Near infrared (NIR) spectroscopy is an excellent candidate for these applications, with minimal sample preparation for real-time decision-making. We will detail the development of a golf ball-sized NIR spectrometer developed specifically for this purpose. The instrument is based upon a thin-film dispersive element that is very stable over time and temperature, with less than 2 nm change expected over the operating temperature range and lifetime of the instrument. This filter is coupled with an uncooled InGaAs detector array in a small, rugged, environmentally stable optical bench ideally suited to unpredictable environments. The resulting instrument weighs less than 60 grams, includes onboard illumination and collection optics for diffuse reflectance applications in the 900-1700 nm wavelength range, and is USB-powered. It can be driven in the field by a laptop, tablet or even a smartphone. The software design includes the potential for both on-board and cloud-based storage, analysis and decision-making. The key attributes of the instrument and the underlying design tradeoffs will be discussed, focusing on miniaturization, ruggedization, power consumption and cost. The optical performance of the instrument, as well as its fit-for purpose will be detailed. Finally, we will show that our manufacturing process has enabled us to build instruments with excellent unit-to-unit reproducibility. We will show that this is a key enabler for instrumentindependent chemical analysis models, a requirement for mass point-of-use deployment.

  16. Anions Analysis in Ground and Tap Waters by Sequential Chemical and CO2-Suppressed Ion Chromatography

    Directory of Open Access Journals (Sweden)

    Glen Andrew D. De Vera

    2011-06-01

    Full Text Available An ion chromatographic method using conductivity detection with sequential chemical and CO2 suppression was optimized for the simultaneous determination of fluoride, chloride, bromide, nitrate,phosphate and sulfate in ground and tap water. The separation was done using an anion exchange column with an eluent of 3.2 mM Na2CO3 and 3.2 mM NaHCO3 mixture. The method was linear in the concentration range of 5 to 300 μg/L with correlation coefficients greater than 0.99 for the six inorganic anions. The method was also shown to be applicable in trace anions analysis as given by the low method detection limits (MDL. The MDL was 1μg/L for both fluoride and chloride. Bromide, nitrate, phosphate and sulfate had MDLs of 7 μg/L, 10 μg/L, 9 μg/L and 2 μg/L, respectively. Good precision was obtained as shown in the relative standard deviation of 0.1 to 12% for peak area and 0.1 to 0.3% for retention time. The sensitivity of the method improved with the addition of CO2 suppressor to chemical suppression as shown in the lower background conductivity and detection limits. The recoveries of the anions spiked in water at 300 μg/L level ranged from 100 to 104%. The method was demonstrated to be sensitive, accurate and precise for trace analysis of the six anions and was applied in the anions analysis in ground and tap waters in Malolos, Bulacan. The water samples were found to contain high concentrations of chloride of up to 476 mg/L followed by sulfate (38 mg/L, bromide (1 mg/L, phosphate (0.4 mg/L, fluoride (0.2 mg/L and nitrate (0.1 mg/L.

  17. Biosensors for the analysis of microbiological and chemical contaminants in food.

    Science.gov (United States)

    McGrath, T F; Elliott, C T; Fodey, T L

    2012-04-01

    Increases in food production and the ever-present threat of food contamination from microbiological and chemical sources have led the food industry and regulators to pursue rapid, inexpensive methods of analysis to safeguard the health and safety of the consumer. Although sophisticated techniques such as chromatography and spectrometry provide more accurate and conclusive results, screening tests allow a much higher throughput of samples at a lower cost and with less operator training, so larger numbers of samples can be analysed. Biosensors combine a biological recognition element (enzyme, antibody, receptor) with a transducer to produce a measurable signal proportional to the extent of interaction between the recognition element and the analyte. The different uses of the biosensing instrumentation available today are extremely varied, with food analysis as an emerging and growing application. The advantages offered by biosensors over other screening methods such as radioimmunoassay, enzyme-linked immunosorbent assay, fluorescence immunoassay and luminescence immunoassay, with respect to food analysis, include automation, improved reproducibility, speed of analysis and real-time analysis. This article will provide a brief footing in history before reviewing the latest developments in biosensor applications for analysis of food contaminants (January 2007 to December 2010), focusing on the detection of pathogens, toxins, pesticides and veterinary drug residues by biosensors, with emphasis on articles showing data in food matrices. The main areas of development common to these groups of contaminants include multiplexing, the ability to simultaneously analyse a sample for more than one contaminant and portability. Biosensors currently have an important role in food safety; further advances in the technology, reagents and sample handling will surely reinforce this position. PMID:22278073

  18. Chemical Analysis of a "Miller-Type" Complex Prebiotic Broth : Part I: Chemical Diversity, Oxygen and Nitrogen Based Polymers.

    Science.gov (United States)

    Wollrab, Eva; Scherer, Sabrina; Aubriet, Frédéric; Carré, Vincent; Carlomagno, Teresa; Codutti, Luca; Ott, Albrecht

    2016-06-01

    In a famous experiment Stanley Miller showed that a large number of organic substances can emerge from sparking a mixture of methane, ammonia and hydrogen in the presence of water (Miller, Science 117:528-529, 1953). Among these substances Miller identified different amino acids, and he concluded that prebiotic events may well have produced many of Life's molecular building blocks. There have been many variants of the original experiment since, including different gas mixtures (Miller, J Am Chem Soc 77:2351-2361, 1955; Oró Nature 197:862-867, 1963; Schlesinger and Miller, J Mol Evol 19:376-382, 1983; Miyakawa et al., Proc Natl Acad Sci 99:14,628-14,631, 2002). Recently some of Miller's remaining original samples were analyzed with modern equipment (Johnson et al. Science 322:404-404, 2008; Parker et al. Proc Natl Acad Sci 108:5526-5531, 2011) and a total of 23 racemic amino acids were identified. To give an overview of the chemical variety of a possible prebiotic broth, here we analyze a "Miller type" experiment using state of the art mass spectrometry and NMR spectroscopy. We identify substances of a wide range of saturation, which can be hydrophilic, hydrophobic or amphiphilic in nature. Often the molecules contain heteroatoms, with amines and amides being prominent classes of molecule. In some samples we detect ethylene glycol based polymers. Their formation in water requires the presence of a catalyst. Contrary to expectations, we cannot identify any preferred reaction product. The capacity to spontaneously produce this extremely high degree of molecular variety in a very simple experiment is a remarkable feature of organic chemistry and possibly prerequisite for Life to emerge. It remains a future task to uncover how dedicated, organized chemical reaction pathways may have arisen from this degree of complexity. PMID:26508401

  19. Chemical Analysis of a "Miller-Type" Complex Prebiotic Broth. Part I: Chemical Diversity, Oxygen and Nitrogen Based Polymers

    Science.gov (United States)

    Wollrab, Eva; Scherer, Sabrina; Aubriet, Frédéric; Carré, Vincent; Carlomagno, Teresa; Codutti, Luca; Ott, Albrecht

    2016-06-01

    In a famous experiment Stanley Miller showed that a large number of organic substances can emerge from sparking a mixture of methane, ammonia and hydrogen in the presence of water (Miller, Science 117:528-529, 1953). Among these substances Miller identified different amino acids, and he concluded that prebiotic events may well have produced many of Life's molecular building blocks. There have been many variants of the original experiment since, including different gas mixtures (Miller, J Am Chem Soc 77:2351-2361, 1955; Oró Nature 197:862-867, 1963; Schlesinger and Miller, J Mol Evol 19:376-382, 1983; Miyakawa et al., Proc Natl Acad Sci 99:14,628-14,631, 2002). Recently some of Miller's remaining original samples were analyzed with modern equipment (Johnson et al. Science 322:404-404, 2008; Parker et al. Proc Natl Acad Sci 108:5526-5531, 2011) and a total of 23 racemic amino acids were identified. To give an overview of the chemical variety of a possible prebiotic broth, here we analyze a "Miller type" experiment using state of the art mass spectrometry and NMR spectroscopy. We identify substances of a wide range of saturation, which can be hydrophilic, hydrophobic or amphiphilic in nature. Often the molecules contain heteroatoms, with amines and amides being prominent classes of molecule. In some samples we detect ethylene glycol based polymers. Their formation in water requires the presence of a catalyst. Contrary to expectations, we cannot identify any preferred reaction product. The capacity to spontaneously produce this extremely high degree of molecular variety in a very simple experiment is a remarkable feature of organic chemistry and possibly prerequisite for Life to emerge. It remains a future task to uncover how dedicated, organized chemical reaction pathways may have arisen from this degree of complexity.

  20. Forensic analysis methodology for thermal and chemical characterization of homemade explosives

    International Nuclear Information System (INIS)

    Highlights: • Identification of homemade explosives (HME) is critical for determining the origin of explosive precursor materials. • A novel laser-heating technique was used to obtain the thermal/chemical signatures of HME precursor materials. • Liquid-fuel saturation of the pores of a solid porous oxidizer affected the total specific heat release. • Material thermal signatures were dependent on sample mass and heating rate. • This laser-heating technique can be a useful diagnostic tool for characterizing the thermochemical behavior of HMEs. - Abstract: Forensic identification of homemade explosives is critical for determining the origin of the explosive materials and precursors, and formulation procedures. Normally, the forensic examination of the pre- and post-blast physical evidence lacks specificity for homemade-explosive identification. The focus of this investigation was to use a novel measurement technique, referred to as the laser-driven thermal reactor, to obtain the thermal/chemical signatures of homemade-explosive precursor materials. Specifically, nitromethane and ammonium nitrate were studied under a variety of operating conditions and protocols. Results indicated that liquid-fuel saturation of the internal pores of a solid particle oxidizer appear to be a limiting parameter for the total specific heat release during exothermic processes. Results also indicated that the thermal signatures of these materials are dependent on sample mass and heating rate, for which this dependency may not be detectable by other commercially available thermal analysis techniques. This study has demonstrated that the laser-driven thermal reactor can be a useful diagnostic tool for characterizing the thermal and chemical behavior of trace amounts of homemade-explosive materials

  1. Forensic analysis methodology for thermal and chemical characterization of homemade explosives

    Energy Technology Data Exchange (ETDEWEB)

    Nazarian, Ashot; Presser, Cary, E-mail: cpresser@nist.gov

    2014-01-20

    Highlights: • Identification of homemade explosives (HME) is critical for determining the origin of explosive precursor materials. • A novel laser-heating technique was used to obtain the thermal/chemical signatures of HME precursor materials. • Liquid-fuel saturation of the pores of a solid porous oxidizer affected the total specific heat release. • Material thermal signatures were dependent on sample mass and heating rate. • This laser-heating technique can be a useful diagnostic tool for characterizing the thermochemical behavior of HMEs. - Abstract: Forensic identification of homemade explosives is critical for determining the origin of the explosive materials and precursors, and formulation procedures. Normally, the forensic examination of the pre- and post-blast physical evidence lacks specificity for homemade-explosive identification. The focus of this investigation was to use a novel measurement technique, referred to as the laser-driven thermal reactor, to obtain the thermal/chemical signatures of homemade-explosive precursor materials. Specifically, nitromethane and ammonium nitrate were studied under a variety of operating conditions and protocols. Results indicated that liquid-fuel saturation of the internal pores of a solid particle oxidizer appear to be a limiting parameter for the total specific heat release during exothermic processes. Results also indicated that the thermal signatures of these materials are dependent on sample mass and heating rate, for which this dependency may not be detectable by other commercially available thermal analysis techniques. This study has demonstrated that the laser-driven thermal reactor can be a useful diagnostic tool for characterizing the thermal and chemical behavior of trace amounts of homemade-explosive materials.

  2. 40 CFR Appendix A to Part 136 - Methods for Organic Chemical Analysis of Municipal and Industrial Wastewater

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Methods for Organic Chemical Analysis of Municipal and Industrial Wastewater A Appendix A to Part 136 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) GUIDELINES ESTABLISHING TEST PROCEDURES FOR THE ANALYSIS OF POLLUTANTS Pt. 136, App....

  3. Artificial intelligence/fuzzy logic method for analysis of combined signals from heavy metal chemical sensors

    Energy Technology Data Exchange (ETDEWEB)

    Turek, M. [Institute of Nano- and Biotechnologies (INB), Aachen University of Applied Sciences, Campus Juelich, Juelich (Germany); Institute of Bio- and Nanosystems (IBN), Research Centre Juelich GmbH, Juelich (Germany); Heiden, W.; Riesen, A. [Bonn-Rhein-Sieg University of Applied Sciences, Sankt Augustin (Germany); Chhabda, T.A. [Institute of Nano- and Biotechnologies (INB), Aachen University of Applied Sciences, Campus Juelich, Juelich (Germany); Schubert, J.; Zander, W. [Institute of Bio- and Nanosystems (IBN), Research Centre Juelich GmbH, Juelich (Germany); Krueger, P. [Institute of Biochemistry and Molecular Biology, RWTH Aachen, Aachen (Germany); Keusgen, M. [Institute for Pharmaceutical Chemistry, Philipps-University Marburg, Marburg (Germany); Schoening, M.J. [Institute of Nano- and Biotechnologies (INB), Aachen University of Applied Sciences, Campus Juelich, Juelich (Germany); Institute of Bio- and Nanosystems (IBN), Research Centre Juelich GmbH, Juelich (Germany)], E-mail: m.j.schoening@fz-juelich.de

    2009-10-30

    The cross-sensitivity of chemical sensors for several metal ions resembles in a way the overlapping sensitivity of some biological sensors, like the optical colour receptors of human retinal cone cells. While it is difficult to assign crisp classification values to measurands based on complex overlapping sensory signals, fuzzy logic offers a possibility to mathematically model such systems. Current work goes into the direction of mixed heavy metal solutions and the combination of fuzzy logic with heavy metal-sensitive, silicon-based chemical sensors for training scenarios of arbitrary sensor/probe combinations in terms of an electronic tongue. Heavy metals play an important role in environmental analysis. As trace elements as well as water impurities released from industrial processes they occur in the environment. In this work, the development of a new fuzzy logic method based on potentiometric measurements performed with three different miniaturised chalcogenide glass sensors in different heavy metal solutions will be presented. The critical validation of the developed fuzzy logic program will be demonstrated by means of measurements in unknown single- and multi-component heavy metal solutions. Limitations of this program and a comparison between calculated and expected values in terms of analyte composition and heavy metal ion concentration will be shown and discussed.

  4. Determination of chemical elements in Eucalyptus grandis, manured with Ballad's, by neutrons activation analysis

    International Nuclear Information System (INIS)

    The biosolid is a mud resulting from the biological treatment of wasted liquids. It is considered as a profitable alternative and important to minimize the environmental impact generated by the sewage thrown in to sanitary lands, in forest cultures like the Eucalyptus grandis. The objective of this work was to detect which chemical elements are present in Eucalyptus grandis samples, fertilized with different quantities of biosolid. The eucalyptuses of Estacao Experimental de Ciencias Florestais of Itatinga were planted in March of 1998 and collected with five years old. The used biosolid was produced by Station of Treatment of Sewer of Barueri - SP, classified as kind B. For the determination of the presence and quantity of chemical elements in the eucalyptus samples, an analysis technique by neutronic activation (NAA) was used followed by gamma rays spectroscopy. The samples were irradiated in the Nuclear Reactor IEA-R1 of IPEN-SP, followed by the measure of induced gamma rays activity, using a Detector HPGe. The presence, mainly of Br, Mn, Na and K, was detected in all analyzed samples. (author)

  5. Chemical analysis of Greek pollen - Antioxidant, antimicrobial and proteasome activation properties

    Directory of Open Access Journals (Sweden)

    Gonos Efstathios

    2011-06-01

    Full Text Available Abstract Background Pollen is a bee-product known for its medical properties from ancient times. In our days is increasingly used as health food supplement and especially as a tonic primarily with appeal to the elderly to ameliorate the effects of ageing. In order to evaluate the chemical composition and the biological activity of Greek pollen which has never been studied before, one sample with identified botanical origin from sixteen different common plant taxa of Greece has been evaluated. Results Three different extracts of the studied sample of Greek pollen, have been tested, in whether could induce proteasome activities in human fibroblasts. The water extract was found to induce a highly proteasome activity, showing interesting antioxidant properties. Due to this activity the aqueous extract was further subjected to chemical analysis and seven flavonoids have been isolated and identified by modern spectral means. From the methanolic extract, sugars, lipid acids, phenolic acids and their esters have been also identified, which mainly participate to the biosynthetic pathway of pollen phenolics. The total phenolics were estimated with the Folin-Ciocalteau reagent and the total antioxidant activity was determined by the DPPH method while the extracts and the isolated compounds were also tested for their antimicrobial activity by the dilution technique. Conclusions The Greek pollen is rich in flavonoids and phenolic acids which indicate the observed free radical scavenging activity, the effects of pollen on human fibroblasts and the interesting antimicrobial profile.

  6. Substance Flow Analysis and Source Mapping of Chemical UV-filters

    International Nuclear Information System (INIS)

    Chemical ultraviolet (UV)-filters are used in sunscreens to protect the skin from harmful UV radiation which may otherwise cause sunburns and skin cancer. Commonly used chemical UV-filters are known to cause endocrine disrupting effects in both aquatic and terrestrial animals as well as in human skin cells. Here, source mapping and substance flow analysis were applied to find the sources of six UV-filters (oxybenzone, avobenzone, 4-methylbenzylidene camphor, octyl methoxycinnamate, octyl dimethyl PABA and homosalate) and to identify the most dominant flows of these substances in Denmark. Urban water, composed of wastewater and surface waters, was found to be the primary recipient of UV-filters, whereby wastewater received an estimated 8.5-65 tonnes and surface waters received 7.1-51 tonnes in 2005. In wastewater treatment plants, their sorption onto sludge is perceived to be an important process and presence in effluents can be expected due to a lack of biodegradability. In addition, the use of UV-filters is expected to continue to increase significantly. Not all filters (e.g., octyl dimethyl PABA and homosalate) are used in Denmark. For example, 4-MBC is mainly associated with self-tanning liquids and private import of sunscreens

  7. Analysis and modelling of the energy consumption of chemical batch plants

    Energy Technology Data Exchange (ETDEWEB)

    Bieler, P.S.

    2004-07-01

    This report for the Swiss Federal Office of Energy (SFOE) describes two different approaches for the energy analysis and modelling of chemical batch plants. A top-down model consisting of a linear equation based on the specific energy consumption per ton of production output and the base consumption of the plant is postulated. The model is shown to be applicable to single and multi-product batches for batch plants with constant production mix and multi-purpose batch plants in which only similar chemicals are produced. For multipurpose batch plants with highly varying production processes and changing production mix, the top-down model produced inaccurate results. A bottom-up model is postulated for such plants. The results obtained are discussed that show that the electricity consumption for infrastructure equipment was significant and responsible for about 50% of total electricity consumption. The specific energy consumption for the different buildings was related to the degree of automation and the production processes. Analyses of the results of modelling are presented. More detailed analyses of the energy consumption of this apparatus group show that about 30 to 40% of steam energy is lost and thus a large potential for optimisation exists. Various potentials for making savings, ranging from elimination of reflux conditions to the development of a new heating/cooling-system for a generic batch reactor, are identified.

  8. Repeatability, correlation and path analysis of physical and chemical characteristics of peach fruits

    Directory of Open Access Journals (Sweden)

    Rosana Gonçalves Pires Matias

    2014-12-01

    Full Text Available This study aimed to determine the number of measurements necessary to evaluate physical and chemical characteristics of peach fruits, study the relationships between them and their direct and indirect effects on the content of ascorbic acid and total carotenoids. The characteristics skin and pulp color, fruit weight, suture, equatorial and polar diameters, firmness, soluble solids (SS, titratable acidity (TA, SS/TA ratio, ascorbic acid and total carotenoids were evaluated in 39 cultivars of peach and 3 cultivars of nectarine from the orchard of the Universidade Federal de Viçosa. The repeatability coefficient was estimated by ANOVA and CPCOR. Phenotypic correlation coefficients (rf were estimated and, after the multicollinearity diagnostics, they were unfolded to direct and indirect effects of the explanatory variables on the response variable using path analysis. There was agreement on the magnitude of repeatability coefficients obtained by the two methods; however, they varied among the 14 characteristics. The highest correlations were found between FW, SD, ED and PD. Seven fruits are sufficient to evaluate the physical and chemical characteristics of peach with a correlation coefficient of 90%. The characteristics considered in the path diagrams (b* skin, hº skin, b* pulp, hº pulp, ED, PD, FIR, SS, SS/AT and TC are not the main determinants of the ascorbic acid. The yellow hue of the pulp (hº pulp has the potential to be used in indirect selection for total carotenoids.

  9. Characterization of plutonium-bearing wastes by chemical analysis and analytical electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Behrens, R.G. [Los Alamos National Lab., NM (United States); Buck, E.C.; Dietz, N.L.; Bates, J.K.; Van Deventer, E.; Chaiko, D.J. [Argonne National Lab., IL (United States)

    1995-09-01

    This report summarizes the results of characterization studies of plutonium-bearing wastes produced at the US Department of Energy weapons production facilities. Several different solid wastes were characterized, including incinerator ash and ash heels from Rocky Flats Plant and Los Alamos National Laboratory; sand, stag, and crucible waste from Hanford; and LECO crucibles from the Savannah River Site. These materials were characterized by chemical analysis and analytical electron microscopy. The results showed the presence of discrete PuO{sub 2}PuO{sub 2{minus}x}, and Pu{sub 4}O{sub 7} phases, of about 1{mu}m or less in size, in all of the samples examined. In addition, a number of amorphous phases were present that contained plutonium. In all the ash and ash heel samples examined, plutonium phases were found that were completely surrounded by silicate matrices. Consequently, to achieve optimum plutonium recovery in any chemical extraction process, extraction would have to be coupled with ultrafine grinding to average particle sizes of less than 1 {mu}m to liberate the plutonium from the surrounding inert matrix.

  10. The measurement of the chemically mobile fraction of lead in soil using isotopic dilution analysis

    International Nuclear Information System (INIS)

    The chemically available fraction of lead in eight soils measured by isotopic dilution analysis using 212Pb ranged from 7 to 16% of the total content of lead in soil. The soluble fractions achieved values up to 63% of the total content in 1 M NH4NO3, 1 M MgCl2 and 0.05 M DTPA solutions. Increasing the contact time between water and soil, the water-soil ratio from 1:1 to 5:1 and increasing the temperature of the soil-water suspension raised the chemically available fraction in soil. Comparing various soil parameters and the mobile fraction of lead, only pH shows a significant correlation. The amphoteric character of lead causes a minimum of mobility about pH 6; pH-values below are responsible for the higher mobility of lead as Pb2+, at pH-values above 6 soluble hydroxy and humic acid complexes are formed. (orig.)

  11. The radiometric analysis of non-radioactive materials by chemical exchange

    International Nuclear Information System (INIS)

    The use of radioisotopes to measure the composition of different materials via chemical exchange within an instrument is described. The product of the reaction is a radioactive gas which is counted and serves as the indicator of measurement. This method has been applied to a number of different liquids and gases for their specific and sensitive determination. The chief limiting condition on sensitivity is imposed by the specific activity of the radiochemical component. Where high specific activities are available, sensitivity in terms of chemical quantity will be very great. The recent development of quinol- Kr85 clathrate compounds has provided a basic radiochemical source which not only provides high specific activities at low cost but also excellent half-life and energy characteristics. These clathrate compounds can be oxidized only by very strong oxidizing agents, such as ozone to release Kr85. When coupled with a salt, such as sodium chlorite, the sensing of reducing materials such as SO2 may be accomplished. Two applications of the radiometric technique employing clathrates are described. The first is the development of a balloon-borne sonde for the meteorological analysis of ozone in the upper atmosphere. The other is its use in air pollution and process control work in the form of a portable analyser. Different gases may be analysed by this device by merely changing the radiochemical reaction cell. (author)

  12. Sampling and chemical analysis of smoke gas components from the SP Industry Calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Maansson, M.; Blomqvist, P.; Isaksson, I.; Rosell, L.

    1995-12-31

    This report describes the sampling and chemical analyses of smoke gas components for combustion performed in the SP Industry Calorimeter, where continuous measurements of oxygen, carbon dioxide and carbon monoxide are an integrated part of the Calorimeter system. On-line measurements of nitrogen oxides and total amounts of unburnt hydrocarbons were performed. Hydrogen cyanide, hydrogen chloride and ammonia in the smoke were sampled and absorbed in impinger bottles and subsequently analyzed using wet chemical techniques. An adsorbent sampling system was designed to allow the identification and quantitative analysis of individual organic compounds in the smoke. Gas chromatography was utilized with a mass spectrometric detector for the identification and a FID for quantification of the total amounts as well as individual components. A procedure for cleaning the smoke gas duct in between the combustion experiments was designed and found to be effective. The materials studied were Nylon 66, polypropylene, polystyrene (with and without fire retardant), PVC, and chlorobenzene. A total of 19 large-scale tests were carried out. The mass of sample burnt ranged from 20 kg to 125 kg in an experiment. 14 refs, 11 tabs

  13. Substance Flow Analysis and Source Mapping of Chemical UV-filters

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, E., E-mail: eve@env.dtu.dk; Andersen, H. R.; Ledin, A. [Technical University of Denmark, Department of Environmental Engineering (Denmark)

    2008-12-15

    Chemical ultraviolet (UV)-filters are used in sunscreens to protect the skin from harmful UV radiation which may otherwise cause sunburns and skin cancer. Commonly used chemical UV-filters are known to cause endocrine disrupting effects in both aquatic and terrestrial animals as well as in human skin cells. Here, source mapping and substance flow analysis were applied to find the sources of six UV-filters (oxybenzone, avobenzone, 4-methylbenzylidene camphor, octyl methoxycinnamate, octyl dimethyl PABA and homosalate) and to identify the most dominant flows of these substances in Denmark. Urban water, composed of wastewater and surface waters, was found to be the primary recipient of UV-filters, whereby wastewater received an estimated 8.5-65 tonnes and surface waters received 7.1-51 tonnes in 2005. In wastewater treatment plants, their sorption onto sludge is perceived to be an important process and presence in effluents can be expected due to a lack of biodegradability. In addition, the use of UV-filters is expected to continue to increase significantly. Not all filters (e.g., octyl dimethyl PABA and homosalate) are used in Denmark. For example, 4-MBC is mainly associated with self-tanning liquids and private import of sunscreens.

  14. Characterization of plutonium-bearing wastes by chemical analysis and analytical electron microscopy

    International Nuclear Information System (INIS)

    This report summarizes the results of characterization studies of plutonium-bearing wastes produced at the US Department of Energy weapons production facilities. Several different solid wastes were characterized, including incinerator ash and ash heels from Rocky Flats Plant and Los Alamos National Laboratory; sand, stag, and crucible waste from Hanford; and LECO crucibles from the Savannah River Site. These materials were characterized by chemical analysis and analytical electron microscopy. The results showed the presence of discrete PuO2PuO2-x, and Pu4O7 phases, of about 1μm or less in size, in all of the samples examined. In addition, a number of amorphous phases were present that contained plutonium. In all the ash and ash heel samples examined, plutonium phases were found that were completely surrounded by silicate matrices. Consequently, to achieve optimum plutonium recovery in any chemical extraction process, extraction would have to be coupled with ultrafine grinding to average particle sizes of less than 1 μm to liberate the plutonium from the surrounding inert matrix

  15. Kinetics analysis of chemiluminescence in discharge-driven HF chemical lasers

    Institute of Scientific and Technical Information of China (English)

    Wei Luo; Shengfu Yuan; Baozhu Yan; Qisheng Lu; Qianjin Zou

    2011-01-01

    The chcinilummescence spectrum in the optical cavity of discharge-driven hydrogen fluoride (HF) chemical laser is measured. The result reveals that the spectra of the helium and fluorine (F) atoms are the major components. Moreover, the green chemiluminescence in the downstream of the optical axis is mostly composed of the 60P20 spectral line of the HF molecule. The analysis shows that, except for the cold pumping reaction, the recombination of the F atoms and the hot pumping reaction also occur in the optical cavity. Due to the hot. Pumping reaction and the optical cavity temperature in a specific range, the 60P20 line becomes the strongest HF molecule in the downstream region of the optical axis. After the hot pumping reaction, the green chcmilum inference always appears in the downstream region of the optical axis when the optical cavity temperature varies in a greater range.%@@ The chemiluminescence spectrum in the optical cavity of discharge-driven hydrogen fluoride(HF) chemical laser is measured.The result reveals that the spectra of the helium and fluorine(F) atoms are the major components.Moreover,the green chemiluminescence in the downstream of the optical axis is mostly composed of the 60P20 spectral line of the HF molecule.

  16. Chemical analysis and antihyperglycemic activity of an original extract from burdock root (Arctium lappa).

    Science.gov (United States)

    Tousch, Didier; Bidel, Luc P R; Cazals, Guillaume; Ferrare, Karine; Leroy, Jeremy; Faucanié, Marie; Chevassus, Hugues; Tournier, Michel; Lajoix, Anne-Dominique; Azay-Milhau, Jacqueline

    2014-08-01

    In the present study, we obtained a dried burdock root extract (DBRE) rich in caffeoylquinic acids derivatives. We performed the chemical characterization of DBRE and explored its antihyperglycemic potential in both in vitro and in vivo experiments. Chemical analysis of DBRE using LC-MS and GC-MS revealed the presence of a great majority of dicaffeoylquinic acid derivatives (75.4%) of which 1,5-di-O-caffeoyl-4-O-maloylquinic acid represents 44% of the extract. In the in vitro experiments, DBRE is able to increase glucose uptake in cultured L6 myocytes and to decrease glucagon-induced glucose output from rat isolated hepatocytes together with a reduction of hepatic glucose 6-phosphatase activity. DBRE did not increase insulin secretion in the INS-1 pancreatic β-cell line. In vivo, DBRE improves glucose tolerance both after intraperitoneal and oral subchronic administration. In conclusion, our data demonstrate that DBRE constitutes an original set of caffeoylquinic acid derivatives displaying antihyperglycemic properties. PMID:24933284

  17. Chemical Analysis and Antioxidant Activity in vitro of Polysaccharides Extracted from Lower Grade Green Tea

    Directory of Open Access Journals (Sweden)

    Ping Chen

    2013-10-01

    Full Text Available Tea is a well-known and important agricultural product in the world. The Crude Polysaccharides from tea leaves (CP probably have good antioxidant activities. However, whether or not the antioxidant abilities of CP depend on tea polyphenols in the CP is not understanded. In this study, four CP fractions (TPF30, TPF50, TPF70 and TPF90 were isolated from CP and their antioxidant activities were compared. Meanwhile, Chemical and physical characteristics of CP and four CP fractions were investigated by the combination of chemical and instrumental analysis methods. Their antioxidant activities were investigated in vitro systems, including hydroxyl radical assay, 1, 1-Diphenyl-2-Picrylhydrazyl (DPPH• scavenging activity, reducing power and chelating activity. Among CP and these four polysaccharides, TPF90 showed more significant DPPH• scavenging activity and highest reducing power, chelating activity and inhibitory effects on hydroxyl radical. Thus, it can be concluded that polysaccharides extracted from the lower grade green tea might be employed as ingredients in healthy and functional food to alleviate the oxidative stress.

  18. Artificial intelligence/fuzzy logic method for analysis of combined signals from heavy metal chemical sensors

    International Nuclear Information System (INIS)

    The cross-sensitivity of chemical sensors for several metal ions resembles in a way the overlapping sensitivity of some biological sensors, like the optical colour receptors of human retinal cone cells. While it is difficult to assign crisp classification values to measurands based on complex overlapping sensory signals, fuzzy logic offers a possibility to mathematically model such systems. Current work goes into the direction of mixed heavy metal solutions and the combination of fuzzy logic with heavy metal-sensitive, silicon-based chemical sensors for training scenarios of arbitrary sensor/probe combinations in terms of an electronic tongue. Heavy metals play an important role in environmental analysis. As trace elements as well as water impurities released from industrial processes they occur in the environment. In this work, the development of a new fuzzy logic method based on potentiometric measurements performed with three different miniaturised chalcogenide glass sensors in different heavy metal solutions will be presented. The critical validation of the developed fuzzy logic program will be demonstrated by means of measurements in unknown single- and multi-component heavy metal solutions. Limitations of this program and a comparison between calculated and expected values in terms of analyte composition and heavy metal ion concentration will be shown and discussed.

  19. Chemical analysis of interstitial water in rivers of Centro Experimental Aramar area

    International Nuclear Information System (INIS)

    This work presents the results from analysis of samples of interstitial waters for the following chemical parameters: F-, Cl-, NO2-, Br-, NO3-, PO43-, SO42- by Ionic Chromatography, Na, K by Flame Photometry, Al, Cd, Pb, Cu, Cr, Fe, Mn, Ni, Zn by ICP OES, pH and the biological parameter: toxicity by natural bioluminescent bacterium (Vibrio fischeri) bioassay. The samples were obtained from sediments collected in 6 different sampling locations, in a ratio of 10-km-long from Centro Experimental Aramar (CEA). The rivers were the samples came from were: Ipanema River, Sorocaba River and Ribeirao do Ferro River. The interstitial water was extracted by centrifugation (3000 rpm, 20 min, 4 deg C). Analysis for metal concentrations were carried out after acid digestion and others tests proceeded in the sample after filtration without further treatment. These data will contribute to evaluate the distribution of contaminants and nutrients in these collecting points and this toxicity status. The release of soluble substances from sediments to interstitial water provides one way for bioaccumulation of these compounds and may affect the survival or development of aquatic organisms. The analysis in interstitial water has never been evaluated at this sampling points and the importance of this study is collecting data providing a better knowledge of the hydrological conditions in which Centro Experimental Aramar is located. (author)

  20. Final Safety Analysis Document for Building 693 Chemical Waste Storage Building at Lawrence Livermore National Laboratory

    International Nuclear Information System (INIS)

    This Safety Analysis Document (SAD) for the Lawrence Livermore National Laboratory (LLNL) Building 693, Chemical Waste Storage Building (desipated as Building 693 Container Storage Unit in the Laboratory's RCRA Part B permit application), provides the necessary information and analyses to conclude that Building 693 can be operated at low risk without unduly endangering the safety of the building operating personnel or adversely affecting the public or the environment. This Building 693 SAD consists of eight sections and supporting appendices. Section 1 presents a summary of the facility designs and operations and Section 2 summarizes the safety analysis method and results. Section 3 describes the site, the facility desip, operations and management structure. Sections 4 and 5 present the safety analysis and operational safety requirements (OSRs). Section 6 reviews Hazardous Waste Management's (HWM) Quality Assurance (QA) program. Section 7 lists the references and background material used in the preparation of this report Section 8 lists acronyms, abbreviations and symbols. Appendices contain supporting analyses, definitions, and descriptions that are referenced in the body of this report

  1. Chemical composition of lateritic ores and its industrial processing products by neutron activation analysis

    International Nuclear Information System (INIS)

    Several techniques of neutron activation analysis for the determination of chemical composition of lateritic ores and in its industrial processing products has been assayed. Instrumental neutron activation analysis with thermal neutrons from reactor combined with short irradiations, allowed the determination of a group of elements, but it was practically not applicable with long irradiations due to the strongly interferences of Co-60, Cr-51, Sc-46 and Fe-59. Reactor epithermal neutron activation analysis (ENAA), significantly reduced such interferences and at least 20 elements had been determined by this technique. An improvement of practical detection limits (10-6%) had been achieved combining the ENAA with one step radiochemical separation by using either the ion exchange in samples of ores and tails or the cobalt liquid extraction in the elaborated products. Nearly 30 elements had been determined by this combination, that also gives a valuable information concerning the distribution of some ''dispersed'' (Se, Ir, Au, etc.) and rare earths elements (La, Sm, Yb, Lu, etc.) during the industrial treatment of lateritic ores in Cuba. 21 refs

  2. Chemical analysis of interstitial water in rivers of Centro Experimental Aramar area

    Energy Technology Data Exchange (ETDEWEB)

    Matoso, Erika; Goncalves, Julia Rosa, E-mail: ematoso@hotmail.com [Centro Tecnologico da Marinha (CE/CTM-SP), Ipero, SP (Brazil). Centro Experimental Aramar; Cadore, Solange [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Instituto de Quimica. Departamento de Quimica Analitica

    2013-07-01

    This work presents the results from analysis of samples of interstitial waters for the following chemical parameters: F{sup -}, Cl{sup -}, NO{sub 2}{sup -}, Br{sup -}, NO{sub 3}{sup -}, PO{sub 4}{sup 3-}, SO{sub 4}{sup 2-} by Ionic Chromatography, Na, K by Flame Photometry, Al, Cd, Pb, Cu, Cr, Fe, Mn, Ni, Zn by ICP OES, pH and the biological parameter: toxicity by natural bioluminescent bacterium (Vibrio fischeri) bioassay. The samples were obtained from sediments collected in 6 different sampling locations, in a ratio of 10-km-long from Centro Experimental Aramar (CEA). The rivers were the samples came from were: Ipanema River, Sorocaba River and Ribeirao do Ferro River. The interstitial water was extracted by centrifugation (3000 rpm, 20 min, 4 deg C). Analysis for metal concentrations were carried out after acid digestion and others tests proceeded in the sample after filtration without further treatment. These data will contribute to evaluate the distribution of contaminants and nutrients in these collecting points and this toxicity status. The release of soluble substances from sediments to interstitial water provides one way for bioaccumulation of these compounds and may affect the survival or development of aquatic organisms. The analysis in interstitial water has never been evaluated at this sampling points and the importance of this study is collecting data providing a better knowledge of the hydrological conditions in which Centro Experimental Aramar is located. (author)

  3. Atmospheric pressure chemical ionization Fourier transform ion cyclotron resonance mass spectrometry for complex thiophenic mixture analysis

    KAUST Repository

    Hourani, Nadim

    2013-10-01

    Rationale Polycyclic aromatic sulfur heterocycles (PASHs) are detrimental species for refining processes in petroleum industry. Current mass spectrometric Methods that determine their composition are often preceded by derivatization and dopant addition approaches. Different ionization Methods have different impact on the molecular assignment of complex PASHs. The analysis of such species under atmospheric pressure chemical ionization (APCI) is still considered limited due to uncontrolled ion generation with low- and high-mass PASHs. Methods The ionization behavior of a model mixture of five selected PASH standards was investigated using an APCI source with nitrogen as the reagent gas. A complex thiophenic fraction was separated from a vacuum gas oil (VGO) and injected using the same method. The samples were analyzed using Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS). RESULTS PASH model analytes were successfully ionized and mainly [M + H]+ ions were produced. The same ionization pattern was observed for the real thiophenic sample. It was found that S1 class species were the major sulfur-containing species found in the VGO sample. These species indicated the presence of alkylated benzothiophenic (BT), dibenzothiophenic (DBT) and benzonaphthothiophenic (BNT) series that were detected by APCI-FTICR MS. CONCLUSIONS This study provides an established APCI-FTICR MS method for the analysis of complex PASHs. PASHs were detected without using any derivatization and without fragmentation. The method can be used for the analysis of S-containing crude oil samples. © 2013 John Wiley & Sons, Ltd.

  4. A model for reliability analysis and calculation applied in an example from chemical industry

    Directory of Open Access Journals (Sweden)

    Pejović Branko B.

    2010-01-01

    Full Text Available The subject of the paper is reliability design in polymerization processes that occur in reactors of a chemical industry. The designed model is used to determine the characteristics and indicators of reliability, which enabled the determination of basic factors that result in a poor development of a process. This would reduce the anticipated losses through the ability to control them, as well as enabling the improvement of the quality of production, which is the major goal of the paper. The reliability analysis and calculation uses the deductive method based on designing of a scheme for fault tree analysis of a system based on inductive conclusions. It involves the use standard logical symbols and rules of Boolean algebra and mathematical logic. The paper eventually gives the results of the work in the form of quantitative and qualitative reliability analysis of the observed process, which served to obtain complete information on the probability of top event in the process, as well as objective decision making and alternative solutions.

  5. Micro Chemical (Elemental Analysis of Leucas aspera (Willd Link Employing SEM-EDAX

    Directory of Open Access Journals (Sweden)

    Sunkara Yashvanth

    2013-01-01

    Full Text Available The plant, Leucas aspera (Willd Link is well known for its varied medicinal uses. Present study deals with its micro chemical (elemental characterization using Energy Dispersive X-ray Analysis (EDAX detector fitted to Scanning Electron Microscope. The plant has very interesting morphology. Crystals of varied shape and inclusions/exudates were noticed within and on the leaf & stem surfaces. Various plant parts analysed were, stem surface, stem sections, stem inclusions, blebs on stem hairs, crystals of varied shape, root sections, abaxial and adaxial surfaces, flower, seed and seed caruncle. Lot of variation in elemental composition was observed in various plant parts. Major elements detected were Carbon, Oxygen, Calcium, Silica, and Aluminum. Other elements found were Iron, Sodium, potassium, Phosphorus and Chlorine.

  6. Biological uptake analysis of organisms exposed to oil and chemically dispersed oil

    Energy Technology Data Exchange (ETDEWEB)

    Coelho, G. M.; Aurand, D. V. [Ecosystem Management and Associates Inc., Purcellville, VA (United States); Wright, D. A. [Maryland Univ., Chesapeake Biological Laboratory, Solomons, MD (United States)

    1999-07-01

    This paper presents the results of a preliminary evaluation of tissue samples that were archived from a full-scale biological study of water column, inter-tidal and benthic organisms exposed to weathered Arabian crude oil or to the same oil that was chemically dispersed with Corexit 9500. At various intervals during the experiment, fish, oysters and polychaetes were removed from the mesocosm tanks, and the tissue was analyzed for 40 individual PAHs using gas chromatography/mass spectrometry. It was found that it is possible to track PAH body burden in test animal tissues, even if the water column exposure period is very short, therefore inclusion of this type of analysis in future studies would be useful in evaluating effects of thresholds for various profiles, in both mesocosm and laboratory studies. 16 refs., 1 tab., 2 figs.

  7. Biological uptake analysis of organisms exposed to oil and chemically dispersed oil

    Energy Technology Data Exchange (ETDEWEB)

    Coelho, G. M.; Aurand, D. V. [Ecosystem Management and Associates Inc., Purcellville, VA (United States); Wright, D. A. [Maryland Univ., Chesapeake Biological Laboratory, Solomons, MD (United States)

    1999-08-01

    This paper presents the results of a preliminary evaluation of tissue samples that were archived from a full-scale biological study of water column, inter-tidal and benthic organisms exposed to weathered Arabian crude oil or to the same oil that was chemically dispersed with Corexit 9500. At various intervals during the experiment, fish, oysters and polychaetes were removed from the mesocosm tanks, and the tissue was analyzed for 40 individual PAHs using gas chromatography/mass spectrometry. It was found that it is possible to track PAH body burden in test animal tissues, even if the water column exposure period is very short, therefore inclusion of this type of analysis in future studies would be useful in evaluating effects of thresholds for various profiles, in both mesocosm and laboratory studies. 16 refs., 1 tab., 2 figs.

  8. Micro-chemical analysis of diffusion bonded W-SiC joint

    Energy Technology Data Exchange (ETDEWEB)

    Matsuo, Genichiro [Graduate Student, Graduate School of Engineering, Hokkaido University, Sapporo Hokkaido 060-8628 (Japan); Shibayama, Tamaki, E-mail: shiba@ufml.caret.hokudai.ac.jp [Center for Advanced Research of Energy Conversion Materials, Hokkaido University, Sapporo Hokkaido 060-8628 (Japan); Kishimoto, Hirotatsu [Department of Materials Science and Engineering, Muroran Institute of Technology, Muroran Hokkaido 050-8585 (Japan); Hamada, Kouichi; Watanabe, Seiichi [Center for Advanced Research of Energy Conversion Materials, Hokkaido University, Sapporo Hokkaido 060-8628 (Japan)

    2011-10-01

    W and SiC joining has an attractive feature for high-temperature energy conversion systems. However, it is unclear and that is necessary to study the microstructure of the reaction phase between W and SiC by using the thermal diffusion bonding method. This work demonstrates the strengthening mechanism of W and SiC joining through a microstructure analysis of the reaction phase by FE-TEM/EDS and the observation of the interface in W and SiC after the crack propagation in HVEM. The reaction phase was amorphous, with a gap from 500 to 600 nm between W and SiC. Fine precipitates with a diameter of several tens nanometer were formed in the reaction phase. The reaction phase and precipitates did not match the chemical composition of the equilibrium compound. It is conceivable that the reaction phase and precipitates exist as a non-equilibrium condition before they reach equilibrium condition.

  9. The Virtual Product-Process Design Laboratory for Structured Chemical Product Design and Analysis

    DEFF Research Database (Denmark)

    Mattei, Michele; Yunus, Nor Alafiza Binti; Kalakul, Sawitree; Kontogeorgis, Georgios; Woodley, John; Gernaey, Krist; Gani, Rafiqul

    The objective of this paper is to present new methods for design of chemicals based formulated products and their implementation in the software, the Virtual Product-Process Design Laboratory. The new products are tailor-made blended liquid products and emulsion-based products. The new software...... the design and analysis of a wide range of homogeneous formulated products: tailor-made blends, single phase liquid formulations and emulsion-based products. The decision making process is supported by dedicated property models and structured databases, specifically developed for each design problem...... scenario. Output from the software is a small set of most promising product candidates and a short list of recommended experiments that can validate and further fine-tune the product composition. The application of the new features is highlighted through two case studies relative to an emulsion...

  10. Direct Laser Ablation and Ionization of Solids for Chemical Analysis by Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Holt, J K; Nelson, E J; Klunder, G L

    2005-09-02

    A laser ablation/ionization mass spectrometer system is described for the direct chemical analysis of solids. An Nd:YAG laser is used for ablation and ionization of the sample in a quadrupole ion trap operated in an ion-storage (IS) mode that is coupled with a reflectron time-of-flight mass spectrometer (TOF-MS). Single pulse experiments have demonstrated simultaneous detection of up to 14 elements present in glasses in the ppm range. However, detection of the components has produced non-stoichiometric results due to difference in ionization potentials and fractionation effects. Time-of-flight secondary ionization mass spectrometry (TOF-SIMS) was used to spatially map elemental species on the surface and provide further evidence of fractionation effects. Resolution (m/Dm) of 1500 and detection limits of approximately 10 pg have been achieved with a single laser pulse. The system configuration and related operating principles for accurately measuring low concentrations of isotopes are described.

  11. Chemical Analysis: An Indispensable Means for Uncovering Severe Cases of Fraud with Cosmetics and Tattoo Inks.

    Science.gov (United States)

    Hohl, Christopher; Hauri, Urs

    2016-01-01

    Three cases of fraud with commodities containing illegal stealth compounds are presented, which were uncovered by the State Laboratory Basel-City, Switzerland. All three commodities, grapefruit seed extracts, a phytocosmetical skin cream, and tattoo inks, were produced abroad, had forged declarations of ingredients and, in the case of the extracts and the cream, were marketed with far-reaching health claims. While inspections will identify suspicious products and would be able to eliminate health claims to some extent, only chemical analysis can uncover the illegal agents used and give law enforcement bodies the necessary evidence to immediately clamp down on those brands, where the stealth agent presents a serious health hazard to consumers. PMID:27198815

  12. Aluminum doped zirconia nanopowders: Wet-chemical synthesis and structural analysis by Rietveld refinement

    International Nuclear Information System (INIS)

    Alumina/zirconia nanopowders, with up to 20 mol% Al2O3, were prepared by wet-chemical synthesis technique, using controlled hydrolysis of alkoxides. The as-synthesized powders are amorphous, have very high specific surface area and the corresponding particle size smaller than 4 nm. Amorphous powders with 0, 10 and 20 mol% Al2O3 crystallize at 460, 692 and 749 deg. C, respectively, as a single-phase tetragonal zirconia, without any traces of alumina phases. Rietvled refinement of X-ray diffraction data, used for the detailed structural analysis of annealed nanopowders, showed that the high-temperature zirconia phase is stabilized due to the formation of ZrO2/Al2O3 solid solutions. High solubility of alumina in the tetragonal zirconia (up to 28.6 at% Al3+) and stabilization of tetragonal zirconia solid solution up to high temperature (as high as 1150 deg. C) were also confirmed

  13. Assessment of some chemical element contents in Traganum nudatum Del shrub using instrumental neutron activation analysis

    Institute of Scientific and Technical Information of China (English)

    Bouzid Nedjimi; Brahim Beladel

    2015-01-01

    Instrumental neutron activation analysis (INAA) has been used to determine some chemical element contents (K, Ca, Na, Fe, Zn, Co, Eu, Sb, and Sc) in Traganum nudatum Del (Chenopodiaceae family) consumed in North African rangelands by sheep livestock. Samples were collected from the area of Djelfa in an arid steppe of Algeria. Results show that pasture halophyte had sufficient levels of K, Ca, Zn, and Co to meet the requirements of ruminants. However, it seems that this halophyte shrub had substantial amounts of Na, higher than the critical level established by the National Research Council (NRC). Eu, Sb, and Sc were within the safety baseline of all the assayed elements recommended by the NRC. The high Na content (∼10 g/kg) in this halophytic species requires elevated intake of water by livestock.

  14. Analysis of biological and chemical compounds by remote spectroscopy using IR TeX glass fibers

    Science.gov (United States)

    Le Foulgoc, Karine; Le Neindre, Lydia; Guimond, Yann; Ma, Hong Li; Zhang, Xhang H.; Lucas, Jacques

    1995-09-01

    The TeX glasses are attracting much attention as materials for low loss mid-IR optical fibers and are consequently good candidates for thermal imaging, laser power delivery, and more recently remote sensing. The TeX glass fiber, transmitting in a wide optical window, has a minimum attenuation in the 9-10 micrometers region. Fibers with an attenuation of less than 0.5 dB/m have been repeatly obtained. These fibers are coated with a UV curable or thermal plastic, in order to improve their mechanical properites. The IR remote spectroscopy using TeX fibers is one of the most promising applications. This technology allows to perform in situ, real-time, and on-line analysis of chemical and biological compounds. The study of industrial processes such as fermentations has been performed by this method, based on the use of these IR TeX fibers.

  15. Spectral Analysis by XANES Reveals that GPNMB Influences the Chemical Composition of Intact Melanosomes

    Energy Technology Data Exchange (ETDEWEB)

    T Haraszti; C Trantow; A Hedberg-Buenz; M Grunze; M Anderson

    2011-12-31

    GPNMB is a unique melanosomal protein. Unlike many melanosomal proteins, GPNMB has not been associated with any forms of albinism, and it is unclear whether GPNMB has any direct influence on melanosomes. Here, melanosomes from congenic strains of C57BL/6J mice mutant for Gpnmb are compared to strain-matched controls using standard transmission electron microscopy and synchrotron-based X-ray absorption near-edge structure analysis (XANES). Whereas electron microscopy did not detect any ultrastructural changes in melanosomes lacking functional GPNMB, XANES uncovered multiple spectral phenotypes. These results directly demonstrate that GPNMB influences the chemical composition of melanosomes and more broadly illustrate the potential for using genetic approaches in combination with nano-imaging technologies to study organelle biology.

  16. Glass Formation, Chemical Properties and Surface Analysis of Cu-Based Bulk Metallic Glasses

    Directory of Open Access Journals (Sweden)

    Akihisa Inoue

    2011-04-01

    Full Text Available This paper reviews the influence of alloying elements Mo, Nb, Ta and Ni on glass formation and corrosion resistance of Cu-based bulk metallic glasses (BMGs. In order to obtain basic knowledge for application to the industry, corrosion resistance of the Cu–Hf–Ti–(Mo, Nb, Ta, Ni and Cu–Zr–Ag–Al–(Nb bulk glassy alloy systems in various solutions are reported in this work. Moreover, X-ray photoelectron spectroscopy (XPS analysis is performed to clarify the surface-related chemical characteristics of the alloy before and after immersion in the solutions; this has lead to a better understanding of the correlation between the surface composition and the corrosion resistance.

  17. Determination of chemical pollutants in the atmosphere of the Valley of Toluca by neutron activation analysis

    International Nuclear Information System (INIS)

    The studies about the presence of contaminants in the atmosphere of diverse cities have been increased widely because to the problems that those cause to public health. Because of this in 1986 was made an Atmospheric Monitoring Program in the Valley of Toluca including the city of Toluca and Toluca- Lerma industrial corridor. That program consist of a preliminary net of sampling for the recollection of total suspended particles on glass-fiber filters, the sampling was performed two times a week in five different zones. To date have been analyzed some of these filters by atomic absorption in the Chemistry School of the Mexico's State University. In this work, is showed the establishment of chemical treatment technique and the results of quantitative analysis through neutron activation in filters of recent monitoring. (Author)

  18. NMR-based analysis of the chemical composition of Japanese persimmon aqueous extracts.

    Science.gov (United States)

    Ryu, Shoraku; Furihata, Kazuo; Koda, Masanori; Wei, Feifei; Miyakawa, Takuya; Tanokura, Masaru

    2016-03-01

    Japanese persimmon (Diospyros kaki L.) is recognized as an outstanding source of biologically active compounds relating to many health benefits. In the present study, NMR spectroscopy provided a comprehensive metabolic overview of Japanese persimmon juice. Detailed signal assignments of Japanese persimmon juice were carried out using various 2D NMR techniques incorporated with broadband water suppression enhanced through T1 effects (BB-WET) or WET sequences, and 26 components, including minor components, were identified. In addition, most components were quantitatively evaluated by the integration of signals using conventional (1) H NMR and BB-WET NMR. This is the first detailed analysis combined with quantitative characterization of chemical components using NMR for Japanese persimmon. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26482562

  19. Micro-chemical analysis of diffusion bonded W-SiC joint

    International Nuclear Information System (INIS)

    W and SiC joining has an attractive feature for high-temperature energy conversion systems. However, it is unclear and that is necessary to study the microstructure of the reaction phase between W and SiC by using the thermal diffusion bonding method. This work demonstrates the strengthening mechanism of W and SiC joining through a microstructure analysis of the reaction phase by FE-TEM/EDS and the observation of the interface in W and SiC after the crack propagation in HVEM. The reaction phase was amorphous, with a gap from 500 to 600 nm between W and SiC. Fine precipitates with a diameter of several tens nanometer were formed in the reaction phase. The reaction phase and precipitates did not match the chemical composition of the equilibrium compound. It is conceivable that the reaction phase and precipitates exist as a non-equilibrium condition before they reach equilibrium condition.

  20. Determination of rare earth elements in Taiwan monazite by chemical neutron activation analysis

    International Nuclear Information System (INIS)

    Taiwan monazite is a unique mineral obtained from the heavy sand found in the river floor of Tzuo-suei river and En-suei river. Both rivers are flowing parallel with separated narrow area into the sea at southwestern coast of Taiwan. The characteristic of monazite is that it contains considerable rare earth elements (REEs). REEs are considered very useful elements in the local industries and scientific researches such as ceramic, semiconductors, and glass optics. In this study, chemical neutron activation analysis (CNAA) was used to determine the contents of REEs in Taiwan monazite. A few milligram of monazite was digested in the microwave oven for 25 minutes with mixed acid (conc. HNO3 and HClO4). REEs were preconcentrated by hydrated magnesium oxide and CNAA was performed. (author)

  1. Microstructure analysis of chemically synthesized wurtzite-type CdS nanocrystals

    Indian Academy of Sciences (India)

    DEKA KULDEEP; KALITA M P C

    2016-05-01

    Microstructure of chemically synthesized wurtzite-type CdS nanocrystals have been investigated by X-ray diffraction (XRD) peak profile analysis by applying different forms of Williamson–Hall (WH) method viz., uniform deformation model (UDM), uniform stress deformation model (USDM) and uniform deformation energy density model (UDEDM), and transmission electron microscope (TEM) observations. The WH methods show the average crystallite size to beabout 10 nm. Strain, stress and energy density of the nanocrystals are found to be $1.18 \\times 10^{−2}, 0.43$ GPa and $2.27$ kJ m$^{−3}$, respectively. High-resolution TEM (HRTEM) results show the nanocrystals to be in spherical shape with an average crystallite size of 10 nm, thereby complementing the size estimation by WH methods. Further, HRTEM observations reveal the presence of edge dislocations and twin boundaries within the nanocrystals.

  2. Analysis of Chemical Composition of Atmospheric Aerosols Above a South East Asian Rainforest

    Science.gov (United States)

    Robinson, N. H.; Allan, J. D.; Williams, P. I.; Hamilton, J. F.; Chen, Q.; Martin, S. T.; Coe, H.; McFiggans, G. B.

    2008-12-01

    The tropics emit a huge amount of volatile organic compounds (VOCs) into the Earth's atmosphere. The processes by which these gases are oxidised to form secondary organic aerosol (SOA) are not well understood or quantified. Insight into the origins and properties of these particles can be gained by analysis of their composition. Intensive field measurements were carried out as part of the Oxidant and Particle Photochemical Processes (OP3) and the Aerosol Coupling in the Earth System (ACES) projects in the rainforest in Malaysian Borneo. This is the first campaign of its type in a South East Asian rainforest. We present detailed organic aerosol composition measurements made using an Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) at Bukit Atur, a Global Atmosphere Watch site located in the Danum Valley Conservation Area. This is a state-of-the-art field deployable instrument that can provide real time composition, mass loading and aerodynamic particle sizing information. In addition, the mass spectral resolution is sufficient to perform an analysis of the elemental composition of the organic species present. Other tools such as positive matrix factorisation (PMF) have been used to help assess the relative source contributions to the organic aerosol. The aerosol's chemical origins have been further investigated by comparing these spectra to chamber experiments, mass spectral libraries and data from comparable locations in other locations. These data are also being analysed in conjunction with high complexity offline techniques applied to samples collected using filters and a Particle-Into-Liquid Sampler (PILS). Methods used include liquid chromatography and comprehensive two-dimensional gas chromatography coupled to time of flight mass spectrometry. These techniques provide a more detailed chemical characterisation of the SOA and water soluble organic carbon, allowing direct links back to gas phase precursors.

  3. Nano-structural and Nano-chemical analysis of dissimilar metal weld interfaces

    International Nuclear Information System (INIS)

    Dissimilar metal weld is generally applied to nuclear power plant for manufacturing and machining in structural components such as RPV and Pressurizer nozzles. Alloy 152 is used frequently as filler metal in the manufacture of dissimilar metal welds (DMWs) in light water reactors (LWR) to join the low alloy steel (LAS) pressure vessel nozzles and steam generator nozzles to nickel-based wrought alloy or austenitic stainless steel components. The thermal expansion coefficient of the alloy lies between those of ferrite steel and austenitic stainless steel, and it also significantly retards the carbon diffusion from the ferrite base metal to the weld metal. However, in recent years cracking phenomena have been observed in the welded joints. A concern has been raised about the integrity and reliability in the joint transition zone due to the high susceptibility of heat affected zone (HAZ) and fusion zone (FZ) to stress corrosion cracking (SCC). The dissimilar metal joints which were welded between Inconel 690, Ni-based alloy and A533B, low alloy steel with Inconel 152, filler metal were investigated. This study shows microstructural and chemical analysis between Inconel 152 and A533B by using optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM), secondary ion mass spectrometry (SIMS) and 3 dimension atom probe (3D AP). In the root region, OM and SEM analysis show the microstructure which contains the interface of Inconel 152 and A533B near the rooter region. And it shows unidentified band structure which is formed along weld interface. AP and TEM/EDS analyses show the chemical gradient containing higher Fe but lower Mn, Ni and Cr than Inconel 152 and the unidentified band

  4. Integrating bipolar electrochemistry and electrochemiluminescence imaging with microdroplets for chemical analysis.

    Science.gov (United States)

    Wu, Suozhu; Zhou, Zhenyu; Xu, Linru; Su, Bin; Fang, Qun

    2014-03-15

    Here we develop a microdroplet sensor based on bipolar electrochemistry and electrochemiluminescence (ECL) imaging. The sensor was constructed with a closed bipolar cell on a hybrid poly(dimethylsioxane) (PDMS)-indium tin oxide (ITO) glass microchip. The ITO microband functions as the bipolar electrode and its two poles are placed in two spatially separate micro-reservoirs predrilled on the PDMS cover. After loading microliter-sized liquid droplets of tris(2,2'-bipyridyl) ruthenium (II)/2-(dibutylamino) ethanol (Ru(bpy)3(2+)/DBAE) and the analyte to the micro-reservoirs, an appropriate external voltage imposed on the driving electrodes could induce the oxidation of Ru(bpy)3(2+)/DBAE and simultaneous reduction of the analyte at the anodic and cathodic poles, respectively. ECL images generated by Ru(bpy)3(2+)/DBAE oxidation at the anodic pole and the electrical current flowing through the bipolar electrode can be recorded for quantitative analyte detection. Several types of quinones were selected as model analytes to demonstrate the sensor performance. Furthermore, the cathodic pole of bipolar electrode can be modified with (3-aminopropyl)triethoxysilane-gold nanoparticles-horseradish peroxidase composites for hydrogen peroxide detection. This microdroplet sensor with a closed bipolar cell can avoid the interference and cross-contamination between analyte solutions and ECL reporting reagents. It is also well adapted for chemical analysis in the incompatible system, e.g., detection of organic compounds insoluble in water by aqueous ECL generation. Moreover, this microdroplet sensor has advantages of simple structure, high sensitivity, fast response and wide dynamic response, providing great promise for chemical and biological analysis. PMID:24140829

  5. Chemical Analysis of Fractionated Halogens in Atmospheric Aerosols Collected in Okinawa, Japan

    Science.gov (United States)

    Tsuhako, A.; Miyagi, Y.; Somada, Y.; Azechi, S.; Handa, D.; Oshiro, Y.; Murayama, H.; Arakaki, T.

    2013-12-01

    Halogens (Cl, Br and I) play important roles in the atmosphere, e.g. ozone depletion by Br during spring in Polar Regions. Sources of halogens in atmospheric aerosols are mainly from ocean. But, for example, when we analyzed Br- with ion chromatography, its concentrations were almost always below the detection limit, which is also much lower than the estimated concentrations from sodium ion concentrations. We hypothesized that portions of halogens are escaped to the atmosphere, similar to chlorine loss, changed their chemical forms to such as BrO3- and IO3-, and/or even formed precipitates. There was few reported data so far about fractionated halogen concentrations in atmospheric aerosols. Thus, purpose of this study was to determine halogen concentrations in different fractions; free ion, water-soluble chemically transformed ions and precipitates using the authentic aerosols. Moreover, we analyzed seasonal variation for each fraction. Atmospheric aerosol samples were collected at Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS) of Okinawa, Japan during January 2010 and August 2013. A high volume air sampler was used for collecting total particulate matters on quartz filters on a weekly basis. Ultrapure water was used to extract water-soluble factions of halogens. The extracted solutions were filtered with the membrane filter and used for chemical analysis with ion chromatography and ICP-MS. Moreover, the total halogens in aerosols were obtained after digesting aerosols with tetramethylammonium hydroxide (TMAH) using the microwave and analysis with ICP-MS. For Cl, water-soluble Cl- accounted for about 70% of the estimates with Na content. No other forms of water-soluble Cl were found. About 30% of Cl was assumed volatilized to the gas-phase. For Br, water-soluble Br accounted for about 43% of the estimates with Na content, and within the 43%, about 10% of Br was not in the form of Br-. About 46% of Br was assumed volatilized to the gas-phase. For I

  6. Chemical Speciation Analysis and Environmental Behaviour of 127I and 129I

    OpenAIRE

    Hansen, Violeta; Roos, Per

    2011-01-01

    This thesis deals with chemical speciation analysis and behaviour of the anthropogenic radioisotope 129I as well as stable iodine 127I in environmental samples such as freshwater, seawater, soils, sediments and seaweed. The behaviour and chemical speciation of iodine (127I and 129I) in environmental samples are very complex and strongly dependent on several factors, such as water/soil/sediment chemistry, seaweed type, different pH, Eh, quantity and quality of organic matter, microbiological a...

  7. A standard analysis method (SAM) for the automated analysis of polychlorinated biphenyls (PCBs) in soils using the chemical analysis automation (CAA) paradigm: validation and performance

    International Nuclear Information System (INIS)

    The Chemical Analysis Automation (CAA) program is developing a standardized modular automation strategy for chemical analysis. In this automation concept, analytical chemistry is performed with modular building blocks that correspond to individual elements of the steps in the analytical process. With a standardized set of behaviors and interactions, these blocks can be assembled in a 'plug and play' manner into a complete analysis system. These building blocks, which are referred to as Standard Laboratory Modules (SLM), interface to a host control system that orchestrates the entire analytical process, from sample preparation through data interpretation. The integrated system is called a Standard Analysis Method (SAME). A SAME for the automated determination of Polychlorinated Biphenyls (PCB) in soils, assembled in a mobile laboratory, is undergoing extensive testing and validation. The SAME consists of the following SLMs: a four channel Soxhlet extractor, a High Volume Concentrator, column clean up, a gas chromatograph, a PCB data interpretation module, a robot, and a human- computer interface. The SAME is configured to meet the requirements specified in U.S. Environmental Protection Agency's (EPA) SW-846 Methods 3541/3620A/8082 for the analysis of pcbs in soils. The PCB SAME will be described along with the developmental test plan. Performance data obtained during developmental testing will also be discussed

  8. Thermal, Mechanical and Chemical Analysis for VELOX -Verification Experiments for Lunar Oxygen Production

    Science.gov (United States)

    Lange, Caroline; Ksenik, Eugen; Braukhane, Andy; Richter, Lutz

    One major aspect for the development of a long-term human presence on the moon will be sustainability and autonomy of any kind of a permanent base. Important resources, such as breathable air and water for the survival of the crew on the lunar surface will have to be extracted in-situ from the lunar regolith, the major resource on the Moon, which covers the first meter of the lunar surface and contains about 45 At the DLR Bremen we are interested in a compact and flexible lab experimenting facility, which shall demonstrate the feasibility of this process by extracting oxygen out of lunar Regolith, respectively soil simulants and certain minerals in the laboratory case. For this purpose, we have investigated important boundary conditions such as temperatures during the process, chemical reaction characteristics and material properties for the buildup of the facility and established basic requirements which shall be analyzed within this paper. These requirements have been used for the concept development and outline of the facility, which is currently under construction and will be subject to initial tests in the near future. This paper will focus mainly on the theoretical aspects of the facility development. Great effort has been put into the thermal and mechanical outline and pre-analysis of components and the system in a whole. Basic aspects that have been investigated are: 1. Selection of suitable materials for the furnace chamber configuration to provide a high-temperature capable operating mode. 2. Theoretical heat transfer analysis of the designed furnace chamber assembly with subsequent validation with the aid of measured values of the constructed demonstration plant. 3. Description of chemical conversion processes for Hydrogen reduction of Lunar Regolith with corresponding analysis of thermal and reaction times under different boundary conditions. 4. Investigation of the high-temperature mechanical behavior of the constructed furnace chamber with regard to

  9. Data Analysis of Multi-Laser Standoff Spectral identification of chemical and biological compounds

    Energy Technology Data Exchange (ETDEWEB)

    Farahi, R H [ORNL; Zaharov, Viktor [ORNL; Tetard, Laurene [ORNL; Thundat, Thomas George [ORNL; Passian, Ali [ORNL

    2013-01-01

    With the availability of tunable broadband coherent sources that emit mid-infrared radiation with well-defined beam characteristics, spectroscopies that were traditionally not practical for standoff detection1 or for develop- ment of miniaturized infrared detectors2, 3 have renewed interest. While obtaining compositional information for objects from a distance remains a major challenge in chemical and biological sensing, recently we demonstrated that capitalizing on mid-infrared excitation of target molecules by using quantum cascade lasers and invoking a pump probe scheme can provide spectral fingerprints of substances from a variable standoff distance.3 However, the standoff data is typically associated with random fluctuations that can corrupt the fine spectral features and useful data. To process the data from standoff experiments toward better recognition we consider and apply two types of denoising techniques, namely, spectral analysis and Karhunen-Loeve Transform (KLT). Using these techniques, infrared spectral data have been effectively improved. The result of the analysis illustrates that KLT can be adapted as a powerful data denoising tool for the presented pump-probe infrared standoff spectroscopy.

  10. Data analysis of multi-laser standoff spectral identification of chemical and biological compounds

    Science.gov (United States)

    Farahi, R.; Zaharov, V.; Tetard, L.; Thundat, T.; Passian, A.

    2013-06-01

    With the availability of tunable broadband coherent sources that emit mid-infrared radiation with well-defined beam characteristics, spectroscopies that were traditionally not practical for standoff detection1 or for development of miniaturized infrared detectors2, 3 have renewed interest. While obtaining compositional information for objects from a distance remains a major challenge in chemical and biological sensing, recently we demonstrated that capitalizing on mid-infrared excitation of target molecules by using quantum cascade lasers and invoking a pump probe scheme can provide spectral fingerprints of substances from a variable standoff distance.3 However, the standoff data is typically associated with random fluctuations that can corrupt the fine spectral features and useful data. To process the data from standoff experiments toward better recognition we consider and apply two types of denoising techniques, namely, spectral analysis and Karhunen-Loeve Transform (KLT). Using these techniques, infrared spectral data have been effectively improved. The result of the analysis illustrates that KLT can be adapted as a powerful data denoising tool for the presented pump-probe infrared standoff spectroscopy.

  11. A path flux analysis method for the reduction of detailed chemical kinetic mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Wenting; Ju, Yiguang [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States); Chen, Zheng [State Key Laboratory for Turbulence and Complex Systems, College of Engineering, Peking University, Beijing 100871 (China); Gou, Xiaolong [School of Power Engineering, Chongqing University, Chongqing 400044 (China)

    2010-07-15

    A direct path flux analysis (PFA) method for kinetic mechanism reduction is proposed and validated by using high temperature ignition, perfect stirred reactors, and steady and unsteady flame propagations of n-heptane and n-decane/air mixtures. The formation and consumption fluxes of each species at multiple reaction path generations are analyzed and used to identify the important reaction pathways and the associated species. The formation and consumption path fluxes used in this method retain flux conservation information and are used to define the path indexes for the first and the second generation reaction paths related to a targeted species. Based on the indexes of each reaction path for the first and second generations, different sized reduced chemical mechanisms which contain different number of species are generated. The reduced mechanisms of n-heptane and n-decane obtained by using the present method are compared to those generated by the direct relation graph (DRG) method. The reaction path analysis for n-decane is conducted to demonstrate the validity of the present method. The comparisons of the ignition delay times, flame propagation speeds, flame structures, and unsteady spherical flame propagation processes showed that with either the same or significantly less number of species, the reduced mechanisms generated by the present PFA are more accurate than that of DRG in a broad range of initial pressures and temperatures. The method is also integrated with the dynamic multi-timescale method and a further increase of computation efficiency is achieved. (author)

  12. GC-FID coupled with chemometrics for quantitative and chemical fingerprinting analysis of Alpinia oxyphylla oil.

    Science.gov (United States)

    Miao, Qing; Kong, Weijun; Zhao, Xiangsheng; Yang, Shihai; Yang, Meihua

    2015-01-01

    Analytical methods for quantitative analysis and chemical fingerprinting of volatile oils from Alpinia oxyphylla were established. The volatile oils were prepared by hydrodistillation, and the yields were between 0.82% and 1.33%. The developed gas chromatography-flame ionization detection (GC-FID) method showed good specificity, linearity, reproducibility, stability and recovery, and could be used satisfactorily for quantitative analysis. The results showed that the volatile oils contained 2.31-77.30 μL/mL p-cymene and 12.38-99.34 mg/mL nootkatone. A GC-FID fingerprinting method was established, and the profiles were analyzed using chemometrics. GC-MS was used to identify the principal compounds in the GC-FID profiles. The profiles of almost all the samples were consistent and stable. The harvesting time and source were major factors that affected the profile, while the volatile oil yield and the nootkatone content had minor secondary effects. PMID:25459943

  13. Neutron activation analysis for assessing chemical composition of dry dog foods

    International Nuclear Information System (INIS)

    Brazil holds the second largest population of domestic dogs in the world, with 33 million dogs, only behind the United States. The annual consumption of dog food in the country is 1.75 million tons, corresponding to the World's sixth in trade turnover. Dog food is supposed to be a complete and balanced diet, formulated with high quality ingredients. All nutrients and minerals required for an adequate nutrition of dogs are added to the formulation to ensure longevity and welfare. In this context, the present study aimed at assessing the chemical composition of dry dog foods commercialized in Brazil. Thirty-four samples were acquired in the local market of Piracicaba and analyzed by instrumental neutron activation analysis (INAA) to determine the elements As, Br, Ca, Co, Cr, Cs, Fe, K, La, Na, Rb, Sb, Sc, Se, U, and Zn. In general, the concentrations of Ca, Fe, K, Na, and Zn complied with the values required by the Association of American Feed Control Officials (AAFCO). To evaluate the safety of dog food commercialized in Brazil, further investigation is necessary to better understand the presence of toxic elements found in this study, i.e. Sb and U. INAA was useful for the screening analysis of different types and brands of dry dog foods for the determination of both essential and toxic elements. (author)

  14. A highly stable and sensitive chemically modified screen-printed electrode for sulfide analysis

    International Nuclear Information System (INIS)

    We report here a highly stable and sensitive chemically modified screen-printed carbon electrode (CMSPE) for sulfide analysis. The CMSPE was prepared by first ion-exchanging ferricyanide into a Tosflex anion-exchange polymer and then sealing with a tetraethyl orthosilicate sol-gel layer. The sol-gel overlayer coating was crucial to stabilize the electron mediator (i.e., Fe(China)63-) from leaching. The strong interaction between the oxy-hydroxy functional group of sol-gel and the hydrophilic sites of Tosflex makes the composite highly rigid to trap the ferricyanide mediator. An obvious electrocatalytic sulfide oxidation current signal at ∼0.20 V versus Ag/AgCl in pH 7 phosphate buffer solution was observed at the CMSPE. A linear calibration plot over a wide range of 0.1 μM to 1 mM with a slope of 5.6 nA/μM was obtained by flow injection analysis. The detection limit (S/N = 3) was 8.9 nM (i.e., 25.6 ppt). Practical utility of the system was applied to the determination of sulfide trapped from cigarette smoke and sulfide content in hot spring water

  15. Miniature Variable Pressure Scanning Electron Microscope for In-Situ Imaging and Chemical Analysis

    Science.gov (United States)

    Gaskin, Jessica A.; Jerman, Gregory; Gregory, Don; Sampson, Allen R.

    2012-01-01

    NASA Marshall Space Flight Center (MSFC) is leading an effort to develop a Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) for in-situ imaging and chemical analysis of uncoated samples. This instrument development will be geared towards operation on Mars and builds on a previous MSFC design of a mini-SEM for the moon (funded through the NASA Planetary Instrument Definition and Development Program). Because Mars has a dramatically different environment than the moon, modifications to the MSFC lunar mini-SEM are necessary. Mainly, the higher atmospheric pressure calls for the use of an electron gun that can operate at High Vacuum, rather than Ultra-High Vacuum. The presence of a CO2-rich atmosphere also allows for the incorporation of a variable pressure system that enables the in-situ analysis of nonconductive geological specimens. Preliminary testing of Mars meteorites in a commercial Environmental SEM(Tradmark) (FEI) confirms the usefulness of lowcurrent/low-accelerating voltage imaging and highlights the advantages of using the Mars atmosphere for environmental imaging. The unique capabilities of the MVP-SEM make it an ideal tool for pursuing key scientific goals of NASA's Flagship Mission Max-C; to perform in-situ science and collect and cache samples in preparation for sample return from Mars.

  16. Analysis of two phase mass transfer by logarithmic driving force based on chemical thermodynamics

    International Nuclear Information System (INIS)

    In the Purex solvent extraction process in the reprocessing of spent fuel, the concentration of separated composition such as U changes continuously from very high condition to trace level. Also in most cases, water phase and organic phase continuously come in contact by counter flow operation. In this research, by the method of circulating organic phase between single liquid drop column and mixing tank, the extraction behavior of Nd and nitric acid in H2O-NaNO3/HNO3-Nd(NO3)3-100% TBP system was traced continuously, and the results of measurement and analysis are reported. The experimental equipment and the experimental condition are shown. As the driving force for two-phase mass transfer, that having chemical thermodynamic basis was introduced. It is considered that this driving force is effective for the kinetic analysis of mass transfer phenomena. Hereafter, it is necessary to confirm the more strict treatment using activity and the applicability to two-phase mass transfer phenomena. (K.I.)

  17. Chemical analysis of simulated high level waste glasses to support stage III sulfate solubility modeling

    International Nuclear Information System (INIS)

    The U.S. Department of Energy (DOE), Office of Environmental Management (EM) is sponsoring an international, collaborative project to develop a fundamental model for sulfate solubility in nuclear waste glass. The solubility of sulfate has a significant impact on the achievable waste loading for nuclear waste forms within the DOE complex. These wastes can contain relatively high concentrations of sulfate, which has low solubility in borosilicate glass. This is a significant issue for low-activity waste (LAW) glass and is projected to have a major impact on the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Sulfate solubility has also been a limiting factor for recent high level waste (HLW) sludge processed at the Savannah River Site (SRS) Defense Waste Processing Facility (DWPF). The low solubility of sulfate in glass, along with melter and off-gas corrosion constraints, dictate that the waste be blended with lower sulfate concentration waste sources or washed to remove sulfate prior to vitrification. The development of enhanced borosilicate glass compositions with improved sulfate solubility will allow for higher waste loadings and accelerate mission completion.The objective of the current scope being pursued by SHU is to mature the sulfate solubility model to the point where it can be used to guide glass composition development for DWPF and WTP, allowing for enhanced waste loadings and waste throughput at these facilities. A series of targeted glass compositions was selected to resolve data gaps in the model and is identified as Stage III. SHU fabricated these glasses and sent samples to SRNL for chemical composition analysis. SHU will use the resulting data to enhance the sulfate solubility model and resolve any deficiencies. In this report, SRNL provides chemical analyses for the Stage III, simulated HLW glasses fabricated by SHU in support of the sulfate solubility model development.

  18. Trace metals of an acid mine drainage stream using a chemical model (WATEQ) and sediment analysis

    International Nuclear Information System (INIS)

    The high metal contents common to the discharge of acid-mine drainage (AMD) from mines and mine spoils is an environmental concern to both government and industry. This paper reports the results of investigation of the behavior of metals in an AMD system at a former surface coal mine in Tuscarawas County, Oh. AMD discharges from seeps travels, in respective order through a laminar flow stream; a Typha-dominated wetland; a turbulent flow stream; and a sediment retention pond. Dissolved metals (Fe, Mn, Zn, Cr, Cd, Cu, and Al) major and minor components, and other parameters (pH, dissolved oxygen and Eh) were measured in the AMD water at each sample location. A chemical mineral equilibrium model (WATEQ) was used to predict the minerals which should precipitate at each site. Results suggest that the seeps are supersaturated and should be precipitating hematite, goethite and magnetite (iron oxides), and siderite (iron carbonate), whereas water of the other downstream sites were at or below equilibrium conditions for these minerals. The hydrogeochemistry of the AMD was further studied using sequential chemical attacks on the precipitate sediment surface coatings, in order to determine metal concentrations in the exchangeable, carbonate, Fe-Mn oxyhydroxide, and oxidizable fractions. The carbonate and exchangeable fractions of the precipitate are dominated by Ca and Fe, as well as Mg in the carbonate fraction. The Fe-Mn oxyhydroxide fraction contained Fe, Al, Mn, Mg, and trace metals, and also contained the greatest concentration of total elements in the system. The Fe-Mn oxyhydroxide is therefore, the major sink for metals of this AMD system. The decrease in the concentration of metals in the sediment precipitates in the downstream locations, is consistent with WATEQ and water analysis results

  19. Analysis of Pore Pressure and Stress Distribution around a Wellbore Drilled in Chemically Active Elastoplastic Formations

    Science.gov (United States)

    Roshan, Hamid; Rahman, S. S.

    2011-09-01

    Drilling in low-permeable reactive shale formations with water-based drilling mud presents significant challenges, particularly in high-pressure and high-temperature environments. In previous studies, several models were proposed to describe the thermodynamic behaviour of shale. Most shale formations under high pressure are expected to undergo plastic deformation. An innovative algorithm including work hardening is proposed in the framework of thermo-chemo-poroelasticity to investigate the effect of plasticity on stresses around the wellbore. For this purpose a finite-element model of coupled thermo-chemo-poro-elastoplasticity is developed. The governing equations are based on the concept of thermodynamics of irreversible processes in discontinuous systems. In order to solve the plastic problem, a single-step backward Euler algorithm containing a yield surface-correction scheme is used to integrate the plastic stress-strain relation. An initial stress method is employed to solve the non-linearity of the plastic equation. In addition, super convergent patch recovery is used to accurately evaluate the time-dependent stress tensor from nodal displacement. The results of this study reveal that thermal and chemical osmosis can significantly affect the fluid flow in low-permeable shale formations. When the salinity of drilling mud is higher than that of pore fluid, fluid is pulled out of the formation by chemical osmotic back flow. Similar results are observed when the temperature of drilling mud is lower than that of the formation fluid. It is found that linear elastic approaches to wellbore stability analysis appear to overestimate the tangential stress around the wellbore and produce more conservative stresses compared to the results of field observation. Therefore, the drilling mud properties obtained from the elastoplastic wellbore stability in shales provide a safer mud weight window and reduce drilling cost.

  20. Lagrangian analysis of microphysical and chemical processes in the Antarctic stratosphere: a case study

    Science.gov (United States)

    Di Liberto, L.; Lehmann, R.; Tritscher, I.; Fierli, F.; Mercer, J. L.; Snels, M.; Di Donfrancesco, G.; Deshler, T.; Luo, B. P.; Grooß, J.-U.; Arnone, E.; Dinelli, B. M.; Cairo, F.

    2015-06-01

    We investigated chemical and microphysical processes in the late winter in the Antarctic lower stratosphere, after the first chlorine activation and initial ozone depletion. We focused on a time interval when both further chlorine activation and ozone loss, but also chlorine deactivation, occur. We performed a comprehensive Lagrangian analysis to simulate the evolution of an air mass along a 10-day trajectory, coupling a detailed microphysical box model to a chemistry model. Model results have been compared with in situ and remote sensing measurements of particles and ozone at the start and end points of the trajectory, and satellite measurements of key chemical species and clouds along it. Different model runs have been performed to understand the relative role of solid and liquid polar stratospheric cloud (PSC) particles for the heterogeneous chemistry, and for the denitrification caused by particle sedimentation. According to model results, under the conditions investigated, ozone depletion is not affected significantly by the presence of nitric acid trihydrate (NAT) particles, as the observed depletion rate can equally well be reproduced by heterogeneous chemistry on cold liquid aerosol, with a surface area density close to background values. Under the conditions investigated, the impact of denitrification is important for the abundances of chlorine reservoirs after PSC evaporation, thus stressing the need to use appropriate microphysical models in the simulation of chlorine deactivation. We found that the effect of particle sedimentation and denitrification on the amount of ozone depletion is rather small in the case investigated. In the first part of the analyzed period, when a PSC was present in the air mass, sedimentation led to a smaller available particle surface area and less chlorine activation, and thus less ozone depletion. After the PSC evaporation, in the last 3 days of the simulation, denitrification increases ozone loss by hampering chlorine

  1. Physical and chemical analysis of Passiflora seeds and seed oil from China.

    Science.gov (United States)

    Liu, Shucheng; Yang, Feng; Li, Jiali; Zhang, Chaohua; Ji, Hongwu; Hong, Pengzhi

    2008-01-01

    The physical and chemical properties of seeds and seed oil from 'Tainung No. 1' passion fruit in China have been analyzed in order to evaluate their nutritional value. Proximate analysis shows that the seeds have a high amount of protein (10.8 +/- 0.60%) and are rich in oil (23.40 +/- 2.50%). The seeds are found to be a good source of minerals. They contain considerable amounts of sodium (2.980 +/- 0.002 mg/g), magnesium (1.540 +/- 0.001 mg/g), potassium (0.850 +/- 0.001 mg/g), and calcium (0.540 +/- 0.002 mg/g). The passion fruit seeds contain the 17 amino acids that are found naturally in plant protein (tryptophan is not analyzed). The essential amino acids account for 34% of the 17 amino acids. The amino acid score of passion fruit seeds protein is 74 and the first limiting amino acid is methionine and cystine. The oil extracted by solvent and supercritical dioxide carbon is liquid at room temperature and the color is golden-orange. The specific gravity of the oil is about 0.917. Comparing the chemical properties of the oil extracted by solvent with that by supercritical dioxide carbon, the latter may be suitable as edible oil directly, while the former will be edible after it must be refined to improve on clarity. Fatty acid composition of the seed oil indicates that the oil contains two essential fatty acids (linoleic acid and linolenic acid), but the content of linoleic acid (72.69 +/- 0.32%) is by far greater than that of linolenic acid (0.26 +/- 0.00%). The present analytical results show the passion fruit seed to be a potentially valuable non-conventional source for high-quality oil. PMID:18608550

  2. Group Analysis of Free Convection Flow of a Magnetic Nanofluid with Chemical Reaction

    Directory of Open Access Journals (Sweden)

    Md. Jashim Uddin

    2015-01-01

    Full Text Available A theoretical study of two-dimensional magnetohydrodynamics viscous incompressible free convective boundary layer flow of an electrically conducting, chemically reacting nanofluid from a convectively heated permeable vertical surface is presented. Scaling group of transformations is used in the governing equations and the boundary conditions to determine absolute invariants. A third-order ordinary differential equation which corresponds to momentum conservation and two second-order ordinary differential equations which correspond to energy and nanoparticle volume fraction (species conservation are derived. Our (group analysis indicates that, for the similarity solution, the convective heat transfer coefficient and mass transfer velocity are proportional to x-1/4 whilst the reaction rate is proportional to x-1/2, where x is the axial distance from the leading edge of the plate. The effects of the relevant controlling parameters on the dimensionless velocity, temperature, and nanoparticle volume fraction are examined. The accuracy of the technique we have used was tested by performing comparisons with the results of published work and the results were found to be in good agreement. The present computations indicate that the flow is accelerated and temperature enhanced whereas nanoparticle volume fractions are decreased with increasing order of chemical reaction. Furthermore the flow is strongly decelerated, whereas the nanoparticle volume fraction and temperature are enhanced with increasing magnetic field parameter. Increasing convection-conduction parameter increases velocity and temperatures but has a weak influence on nanoparticle volume fraction distribution. The present study demonstrates the thermal enhancement achieved with nanofluids and also magnetic fields and is of relevance to nanomaterials processing.

  3. Chemical analysis of simulated high level waste glasses to support stage III sulfate solubility modeling

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-17

    The U.S. Department of Energy (DOE), Office of Environmental Management (EM) is sponsoring an international, collaborative project to develop a fundamental model for sulfate solubility in nuclear waste glass. The solubility of sulfate has a significant impact on the achievable waste loading for nuclear waste forms within the DOE complex. These wastes can contain relatively high concentrations of sulfate, which has low solubility in borosilicate glass. This is a significant issue for low-activity waste (LAW) glass and is projected to have a major impact on the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Sulfate solubility has also been a limiting factor for recent high level waste (HLW) sludge processed at the Savannah River Site (SRS) Defense Waste Processing Facility (DWPF). The low solubility of sulfate in glass, along with melter and off-gas corrosion constraints, dictate that the waste be blended with lower sulfate concentration waste sources or washed to remove sulfate prior to vitrification. The development of enhanced borosilicate glass compositions with improved sulfate solubility will allow for higher waste loadings and accelerate mission completion.The objective of the current scope being pursued by SHU is to mature the sulfate solubility model to the point where it can be used to guide glass composition development for DWPF and WTP, allowing for enhanced waste loadings and waste throughput at these facilities. A series of targeted glass compositions was selected to resolve data gaps in the model and is identified as Stage III. SHU fabricated these glasses and sent samples to SRNL for chemical composition analysis. SHU will use the resulting data to enhance the sulfate solubility model and resolve any deficiencies. In this report, SRNL provides chemical analyses for the Stage III, simulated HLW glasses fabricated by SHU in support of the sulfate solubility model development.

  4. Chemical Species and Content Analysis of 125I in Bok-choy and Ipomoea Aquatica Forsk

    International Nuclear Information System (INIS)

    Iodine has been long known as an indispensable element in the synthesis of thyroid hormones. Severe iodine deficiency in diet leads to iodine deficiency disorders in humans. An isotope tracer experiment was carried out to study the chemical species and content analysis of 125I absorbed by the Bok-choy and Ipomoea Aquatica Forsk. The results showed that inorganic 125I, organic 125I and residual 125I have been detected in Bok-choy and Ipomoea Aquatica Forsk. In Bok-choy,the inorganic 125I content is the most which up to 42.48%, and except for residual 125I the organic 125I content is taken up to 7.91%. But in Ipomoea Aquatica Forsk, the content of 125I ranks as residual 125I > the inorganic 125I > organic 125I followed by 64.97%, 28.36% and 6.66%. The consists of inorganic 125I is I-, IO3-and I2 in both Bok-choy and Ipomoea Aquatica Forsk, and I-is the main chemical species. The protein-125I was the main form of organic iodine which respectively amounts to 22.43% and 8.68% of total iodine, the content of amylose-125I was the least which was 0.78% and 0.40% in both Bok-choy and Ipomoea Aquatica Forsk, and the content of the nucleic acid-125I is between them. The results showed that Bok-choy and Ipomoea Aquatica Forsk can enriched Iodine in environment. so, they could be cultivated as iodine vegetable. (authors)

  5. How Flow Injection Analysis (FIA) over the past 25 years has changed our way of performing chemical analyses

    DEFF Research Database (Denmark)

    Hansen, Elo Harald; Miró, Manuel

    2007-01-01

    Briefly looking back on the impact of flow injection analysis (FIA), as reflected in the rapid growth of publications in the scientific literature, and touching upon many of the novel and unique analytical chemical possibilities that FIA and its sequels, sequential injection analysis (SIA) and Lab......-on-Valve (LOV), have offered, we emphasize assays based on kinetic discrimination schemes, where, even subtle, differences in the reaction rates of the chemical reactions that occur are judiciously exploited. We give a number of examples, covering homogeneous as well as heterogeneous conversions techniques...

  6. Determination of the Calibration Curve for the Neutron-Moisture Meter by Chemical Analysis of Soils

    International Nuclear Information System (INIS)

    calculations based on chemical analysis of the soils. (author)

  7. Chemical imaging and spectroscopy using tunable filters: Instrumentation, methodology, and multivariate analysis

    Science.gov (United States)

    Turner, John Frederick, II

    Spectral imaging has experienced tremendous growth during the past ten years and is rapidly becoming a formidable analytical tool. Recent advances in electronically tunable filters and array detectors are enabling high resolution spectral images to be acquired of chemical and biological systems that have traditionally been difficult to study non-invasively. Additionally, the development of powerful and inexpensive computer platforms is broadening the appeal of spectral imaging methods which have historically required costly and computationally adept computer workstations. The emphasis of my research has been to explore high throughput widefield imaging instrumentation and methodology using novel acousto-optic tunable filter (AOTF) and liquid crystal tunable filter (LCTF) imaging spectrometers. In order to demonstrate the feasibility of employing multiplexed AOTFs for spectroscopy and chemical imaging applications, a near- infrared (NIR) multiplexed AOTF spectrometer employing Hadamard encoding sequences has been developed. In addition, the use of multiplexed AOTFs as adaptive filters in NIR spectroscopy and fluorescence imaging has been demonstrated. A second type of electronically tunable image filter, the liquid crystal tunable filter (LCTF) has recently been developed and is well suited to high resolution, diffraction limited imaging applications. The earliest generation of LCTFs was based on the Lyot birefringent filter and possessed small transmittances due to the use of multiple polarizers and imperfect waveplate action. An improved LCTF prototype incorporating split-element Lyot filter stages has been evaluated and compared to the earlier generation of LCTF devices. The high image fidelity, wide acceptance angle, and large clear aperture of the LCTF make it well suited to macroscopic chemical imaging applications. A macroscopic imaging fluorometer employing LCTFs for source tuning and emission filtering has been developed for high throughput microtiter plate

  8. Application of factor analysis to chemically analyzed data in environmental samples after x-ray fluorescence analysis

    International Nuclear Information System (INIS)

    The underlying principle of factorial analysis is frequency distribution and description of reaction in between and through the element series in specific environmental samples. Application of this factor analysis was elaborated to interpret the variance and covariance of certain elements Si, Al, Ca. K, Fe, Ti and Mg in three different types of common materials in environmental sediments, soil, and rock. These evaluations were proceeded after x-ray fluorescence measurements. Results of applications of factorial statistical data analysis show that three factors cause relationship between the above elements in a certain type of environmental samples are mainly recognized. In such cases, these factors represent the main reason for findings and interpret all hidden relationship between the chemical analyzed data. Factor one, the effect of weathering type alteration and oxidation reaction processes as a main one in case of soil and rock where they are characterized by the close covariance of a group of metals, like iron and manganese, commonly derived from weathered and altered igneous rocks. Factor two and three represents other processes. In case of soil, formation of alumino-silicate is revealed in factor two due to the positive covariance of these elements and also the presence of aluminum oxide, titanium oxide and silicon dioxide together is explained by these positive values. The inverse relation between Ca, K, Fe and Mg while indicate the presence of mineral salts which may be due to fertilization and water of irrigation. In case of factor three in that soil, it is the weakest factor that can be used to explain the relationship between the above elements

  9. Final report on the sampling and analysis of sediment cores from the L-Area oil and chemical basin

    Energy Technology Data Exchange (ETDEWEB)

    1985-08-01

    Nine vibracores were collected in the L-Area oil and chemical basin (904-83G) during late March and early April 1985. These cores were collected for analysis of the sludge on the basin floor and the underlying sediment. Several different field and laboratory analyses were performed on each three inch segment of all the cores. These included: (1) Sediment characterization; (2) Percent moisture; (3) Dry weight; (4) Spectral gamma analysis; (5) Gross alpha and beta analysis. Detailed chemical analysis were measured on selected intervals of 2 cores (LBC-5 and 6) for complete chemical characterization of the sediments. This sampling program was conducted to provide information so that a closure plan for the basin could be developed. This report describes the methods employed during the project and provide a hard copy of the analytical results from the sample analyses. Included in the appendices are copies of all field and laboratory notes taken during the project and copies of the gas chromatograms for the petroleum hydrocarbon analysis. All chemical results were also submitted on a 5-inch floppy disk.

  10. Development of Procedures for the Analysis of Components of Dumped Chemical Weapons and Their Principal Transformation Products in Sea Water

    International Nuclear Information System (INIS)

    A package of chemical analytical procedures was developed for the detection of products indicative of the presence of damped chemical weapons in the Baltic Sea. The principal requirements imposed upon the procedures were the following: high sensitivity, reliable identification of target compounds, wide range of components covered by survey analysis, and lack of interferences from sea salts. Thiodiglycol, a product of hydrolysis of sulfur mustard reportedly always detected in the sites of damping chemical weapons in the Baltic Sea, was considered the principal marker. We developed a high-sensitivity procedure for the determination of thiodiglycol in sea water, involving evaporation of samples to dryness in a vacuum concentrator, followed by tert-butyldimethylsilylation of the residue and GCMS analysis in the SIM mode with meta-fluorobenzoic acid as internal reference. The detection limit of thiodiglycol was 0.001 mg/l, and the procedure throughput was up to 30 samples per day. The same procedure, but with BSTFA as derivatizing agent instead of MTBSTFA, was used for preparing samples for survey analysis of nonvolatile components. In this case, full mass spectra were measured in the GCMS analysis. The use of BSTFA was motivated by the fact that trimethylsilyl derivatives are much wider represented in electronic mass spectral databases. The identification of sulfur mustard, volatile transformation products of sulfur mustard and lewisite, as well as chloroacetophenone in sea water was performed by means of GCMS in combination with SPME. The survey GC-MS analysis was focused on the identification of volatile and nonvolatile toxic chemicals whose mass spectra are included in the OPCW database (3219 toxic chemicals, precursors, and transformation products) with the use of AMDIS software (version 2.62). Using 2 GC-MS instruments, we could perform the survey analysis for volatile and nonvolatile components of up to 20 samples per day. Thus, the package of three procedures

  11. Applying Chemical Imaging Analysis to Improve Our Understanding of Cold Cloud Formation

    Science.gov (United States)

    Laskin, A.; Knopf, D. A.; Wang, B.; Alpert, P. A.; Roedel, T.; Gilles, M. K.; Moffet, R.; Tivanski, A.

    2012-12-01

    The impact that atmospheric ice nucleation has on the global radiation budget is one of the least understood problems in atmospheric sciences. This is in part due to the incomplete understanding of various ice nucleation pathways that lead to ice crystal formation from pre-existing aerosol particles. Studies investigating the ice nucleation propensity of laboratory generated particles indicate that individual particle types are highly selective in their ice nucleating efficiency. This description of heterogeneous ice nucleation would present a challenge when applying to the atmosphere which contains a complex mixture of particles. Here, we employ a combination of micro-spectroscopic and optical single particle analytical methods to relate particle physical and chemical properties with observed water uptake and ice nucleation. Field-collected particles from urban environments impacted by anthropogenic and marine emissions and aging processes are investigated. Single particle characterization is provided by computer controlled scanning electron microscopy with energy dispersive analysis of X-rays (CCSEM/EDX) and scanning transmission X-ray microscopy with near edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS). A particle-on-substrate approach coupled to a vapor controlled cooling-stage and a microscope system is applied to determine the onsets of water uptake and ice nucleation including immersion freezing and deposition ice nucleation as a function of temperature (T) as low as 200 K and relative humidity (RH) up to water saturation. We observe for urban aerosol particles that for T > 230 K the oxidation level affects initial water uptake and that subsequent immersion freezing depends on particle mixing state, e.g. by the presence of insoluble particles. For T cloud formation. Initial results applying single particle IN analysis using CCSEM/EDX and STXM/NEXAFS reveal that a significant amount of IN are coated by organics and, thus, are similar to the

  12. Analysis of the Engineering Restoration Effect of Abandoned Yongledian Quarry in Beijing City Based on Soil Physical and Chemical Properties

    Institute of Scientific and Technical Information of China (English)

    Liwei; CAI

    2014-01-01

    The improvement of the soil physical and chemical properties is the most important foundation for mine ecological restoration.The experiment is aimed at undisturbed area,restored area,and damaged area of abandoned Yongledian Quarry in Beijing.Through determination and analysis of soil physical and chemical properties,it shows that there are significant differences in the composite effects of soil physical and chemical properties between restored area,and undisturbed area,damaged area,and engineering restoration effectively improves the composite effects of soil physical and chemical properties in the restored area.The single factor hypothesis test shows that soil pH value,organic matter,alkali-hydrolyzable nitrogen,and total nitrogen traits are the key targets to be restored in this mining area.

  13. LSENS: A General Chemical Kinetics and Sensitivity Analysis Code for homogeneous gas-phase reactions. Part 3: Illustrative test problems

    Science.gov (United States)

    Bittker, David A.; Radhakrishnan, Krishnan

    1994-01-01

    LSENS, the Lewis General Chemical Kinetics and Sensitivity Analysis Code, has been developed for solving complex, homogeneous, gas-phase chemical kinetics problems and contains sensitivity analysis for a variety of problems, including nonisothermal situations. This report is part 3 of a series of three reference publications that describe LSENS, provide a detailed guide to its usage, and present many example problems. Part 3 explains the kinetics and kinetics-plus-sensitivity analysis problems supplied with LSENS and presents sample results. These problems illustrate the various capabilities of, and reaction models that can be solved by, the code and may provide a convenient starting point for the user to construct the problem data file required to execute LSENS. LSENS is a flexible, convenient, accurate, and efficient solver for chemical reaction problems such as static system; steady, one-dimensional, inviscid flow; reaction behind incident shock wave, including boundary layer correction; and perfectly stirred (highly backmixed) reactor. In addition, the chemical equilibrium state can be computed for the following assigned states: temperature and pressure, enthalpy and pressure, temperature and volume, and internal energy and volume. For static problems the code computes the sensitivity coefficients of the dependent variables and their temporal derivatives with respect to the initial values of the dependent variables and/or the three rate coefficient parameters of the chemical reactions.

  14. Computational analysis of the mechanism of chemical reactions in terms of reaction phases: hidden intermediates and hidden transition States.

    Science.gov (United States)

    Kraka, Elfi; Cremer, Dieter

    2010-05-18

    Computational approaches to understanding chemical reaction mechanisms generally begin by establishing the relative energies of the starting materials, transition state, and products, that is, the stationary points on the potential energy surface of the reaction complex. Examining the intervening species via the intrinsic reaction coordinate (IRC) offers further insight into the fate of the reactants by delineating, step-by-step, the energetics involved along the reaction path between the stationary states. For a detailed analysis of the mechanism and dynamics of a chemical reaction, the reaction path Hamiltonian (RPH) and the united reaction valley approach (URVA) are an efficient combination. The chemical conversion of the reaction complex is reflected by the changes in the reaction path direction t(s) and reaction path curvature k(s), both expressed as a function of the path length s. This information can be used to partition the reaction path, and by this the reaction mechanism, of a chemical reaction into reaction phases describing chemically relevant changes of the reaction complex: (i) a contact phase characterized by van der Waals interactions, (ii) a preparation phase, in which the reactants prepare for the chemical processes, (iii) one or more transition state phases, in which the chemical processes of bond cleavage and bond formation take place, (iv) a product adjustment phase, and (v) a separation phase. In this Account, we examine mechanistic analysis with URVA in detail, focusing on recent theoretical insights (with a variety of reaction types) from our laboratories. Through the utilization of the concept of localized adiabatic vibrational modes that are associated with the internal coordinates, q(n)(s), of the reaction complex, the chemical character of each reaction phase can be identified via the adiabatic curvature coupling coefficients, A(n,s)(s). These quantities reveal whether a local adiabatic vibrational mode supports (A(n,s) > 0) or resists

  15. Comparison of Computed Tomography Histogram Analysis and Chemical-Shift Magnetic Resonance Imaging for Adrenal Mass Characterization

    International Nuclear Information System (INIS)

    Background: Computed tomography (CT) histogram analysis and chemical-shift magnetic resonance imaging (MRI) are currently used modalities for adrenal mass characterization. However, it is not yet clear which modality can be regarded as most sensitive in terms of adrenal mass characterization. Purpose: To prospectively compare CT histogram analysis and chemical-shift MRI in the characterization of adrenal masses. Material and Methods: Between May 2007 and November 2008, 93 patients (45 males, 48 females; mean age 56.7 years, range 22-85 years) with 109 adrenal masses prospectively underwent both unenhanced CT and chemical-shift MRI examinations. These masses consisted of 67 adenomas and 42 metastases. Histogram analysis was applied with a circular region of interest (ROI) that recorded mean attenuation, total number of pixels, number of negative pixels, and the percentage of negative pixels on unenhanced CT images for each adrenal mass. In the CT histogram analysis, a 10% negative pixel threshold for unenhanced CT was calculated. In chemical-shift MRI, signal intensity drop between in-phase and opposed-phase images was quantitatively calculated so that adrenal-to-spleen chemical-shift ratios and adrenal signal intensity indexes were determined for each of the adrenal masses. A mass was regarded as an adenoma if it contained more than 10% negative pixels by CT histogram analysis, showed an adrenal-to-spleen chemical-shift ratio of less than 0.71, and had an adrenal signal intensity index of more than 16.5% by chemical-shift MRI. The results were compared to reveal which method was most sensitive in the diagnosis of adrenal masses and whether or not a correlation exists between these two modalities. Final diagnoses were based on imaging follow-up of minimum 6 months, biopsy, surgery, and adrenal washout study. Results: On unenhanced CT examinations, all of the 67 adenomas and 21 out of 42 metastases exhibited negative pixels. None of the metastases showed more than 10

  16. Comparison of Computed Tomography Histogram Analysis and Chemical-Shift Magnetic Resonance Imaging for Adrenal Mass Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Halefoglu, A.M.; Yasar, A.; Bas, N.; Ozel, A.; Erturk, S.M.; Basak, M. (Dept. of Radiology, Sisli Etfal Training and Research Hospital, Sisli, Istanbul (Turkey))

    2009-11-15

    Background: Computed tomography (CT) histogram analysis and chemical-shift magnetic resonance imaging (MRI) are currently used modalities for adrenal mass characterization. However, it is not yet clear which modality can be regarded as most sensitive in terms of adrenal mass characterization. Purpose: To prospectively compare CT histogram analysis and chemical-shift MRI in the characterization of adrenal masses. Material and Methods: Between May 2007 and November 2008, 93 patients (45 males, 48 females; mean age 56.7 years, range 22-85 years) with 109 adrenal masses prospectively underwent both unenhanced CT and chemical-shift MRI examinations. These masses consisted of 67 adenomas and 42 metastases. Histogram analysis was applied with a circular region of interest (ROI) that recorded mean attenuation, total number of pixels, number of negative pixels, and the percentage of negative pixels on unenhanced CT images for each adrenal mass. In the CT histogram analysis, a 10% negative pixel threshold for unenhanced CT was calculated. In chemical-shift MRI, signal intensity drop between in-phase and opposed-phase images was quantitatively calculated so that adrenal-to-spleen chemical-shift ratios and adrenal signal intensity indexes were determined for each of the adrenal masses. A mass was regarded as an adenoma if it contained more than 10% negative pixels by CT histogram analysis, showed an adrenal-to-spleen chemical-shift ratio of less than 0.71, and had an adrenal signal intensity index of more than 16.5% by chemical-shift MRI. The results were compared to reveal which method was most sensitive in the diagnosis of adrenal masses and whether or not a correlation exists between these two modalities. Final diagnoses were based on imaging follow-up of minimum 6 months, biopsy, surgery, and adrenal washout study. Results: On unenhanced CT examinations, all of the 67 adenomas and 21 out of 42 metastases exhibited negative pixels. None of the metastases showed more than 10

  17. ANALYSIS OF MACRO AND MICROELEMENTS IN TEETH, SALIVA, AND BLOOD OF WORKERS IN FERGANA CHEMICAL PLANT OF FURAN COMPOUNDS

    Directory of Open Access Journals (Sweden)

    Sunnatillo Gaffarov

    2014-11-01

    Full Text Available This article aims to share the results of research conducted in the Fergana chemical plant of furan compounds (FCPFC in Uzbekistan.19 workers of the Furan compounds plant, in Fergana, Uzbekistan, were tested. By neutron activation analysis method, we have studied microelement composition of saliva, blood, dental hard tissue, and the level of Ca, Zn, Fe, and Ag in these subjects. We havedetected that the level of chemical elements in dental hard tissue, blood, and saliva of these workers was subject to negative changes as compared to the analysis results from those in the control group.The research results havepractical value for the prophylaxis, treatment, and health resumption of the people living in rugged ecological environment and workers who are engagedwith harmful substances in chemical industry.  Furthermore,this research also provides recommendations fortreatment of dental diseases related to common conditions of pathophysiological processes carried out bylivingorganisms.

  18. Minimizing chemical interference errors for the determination of lithium in brines by flame atomic absorption spectroscopy analysis

    Institute of Scientific and Technical Information of China (English)

    WEN Xianming; MA Peihua; ZHU Geqin; WU Zhiming

    2006-01-01

    Chemical interferences (ionization and oxide/hydroxide formation) on the atomic absorbance signal of lithium in FAAS analysis of brine samples are elaborated in this article. It is suggested that inadequate or overaddition of deionization buffers can lead to loss of sensitivities under particular operating conditions. In the analysis of brine samples, signal enhancing and oxide/hydroxide formation inducing signal reduction resulting from overaddition of deionization buffers can be seen with varying amounts of chemical buffers. Based on experimental results, the authors have arrived at the op timized operating conditions for the detection of lithium, under which both ionization and stable compound formation can be suppressed. This is a simplified and quick method with adequate accuracy and precision for the determination of lithium in routine brine samples from chemical plants or R&D laboratories, which contain comparable amounts of lithium with some other components.

  19. ANALYSIS OF CHEMICAL COMPOUNDS OF AGARWOOD OIL FROM DIFFERENT SPECIES BY GAS CHROMATOGRAPHY MASS SPECTROMETRY (GCMS

    Directory of Open Access Journals (Sweden)

    Yumi Zuhanis Has-Yun Hashim

    2014-05-01

    Full Text Available ABSTRACT: Agarwood oil is a highly prized type of oil due to its unique aroma. The oil is extracted from the fragrant resin found in the agarwood tree (trunk.  The unique aroma and quality of agarwood resin and oil are contributed by the presence of certain chemical compounds. In this work, analysis and comparison of the chemical compounds of agarwood oil from A. malaccensis, A. sub-integra and a mixture of both were conducted.  The essential oils were diluted in hexane (5% prior to gas chromatography mass spectrometry (GCMS analysis performed using Agilent GCMS 7890A coupled with MSD quadrupole detector 5975 C.  Separation of analytes by gas chromatography was carried out using a Hewlett Packard HP-5MS silica capillary column (30 m X 0.25 mm X 0.25 mm. A total of 107 compounds were identified from the three samples of agarwood oils. Fifty-five (55 components were identified in A. malaccensis sample which contributes to the largest portion of the total compounds. About 20% of the compounds identified were aromatic and sesquiterpenes which have been revealed to be the main active compounds of agarwood oils which also give the aroma and pleasant odour of agarwood. Different compositions or profile of chemical components were found in agarwood oils from the two different species. Two compounds were commonly identified in all three samples namely 3-phenyl-2-butanone and alpha-cubebene.  Further studies are needed to refine the results which later can be used to assist detection and authentication of agarwood as well as its scientific-based grading. ABSTRAK: Minyak gaharu merupakan sejenis minyak beraroma unik yang mendapat permintaan tinggi dan mahal. Minyak ini diekstrak daripada resin beraroma yang terbentuk di dalam batang pokok gaharu. Keunikan aroma dan kualiti resin dan minyak gaharu ini bergantung kepada kehadiran bahan kimia tertentu. Penyelidikan ini menjurus kepada analisis dan perbandingan bahan-bahan kimia yang terdapat dalam minyak

  20. Chemical abundance analysis of the Open Clusters Berkeley 32, NGC 752, Hyades and Praesepe

    CERN Document Server

    Carrera, R

    2011-01-01

    Context. Open clusters are ideal test particles to study the chemical evolution of the Galactic disc. However the existing high-resolution abundance determinations, not only of [Fe/H], but also of other key elements, is largely insufficient at the moment. Aims. To increase the number of Galactic open clusters with high quality abundance determinations, and to gather all the literature determinations published so far. Methods. Using high-resolution (R~30000), high-quality (S/N$>60 per pixel), we obtained spectra for twelve stars in four open clusters with the fiber spectrograph FOCES, at the 2.2 Calar Alto Telescope in Spain. We use the classical equivalent widths analysis to obtain accurate abundances of sixteen elements: Al, Ba, Ca, Co, Cr, Fe, La, Mg, Na, Nd, Ni, Sc, Si, Ti, V, Y. Oxygen abundances have been derived through spectral synthesis of the 6300 A forbidden line. Results. We provide the first determination of abundance ratios other than Fe for NGC 752 giants, and ratios in agreement with the litera...

  1. Guidance on health effects of toxic chemicals. Safety Analysis Report Update Program

    Energy Technology Data Exchange (ETDEWEB)

    Foust, C.B.; Griffin, G.D.; Munro, N.B.; Socolof, M.L.

    1994-02-01

    Martin Marietta Energy Systems, Inc. (MMES), and Martin Marietta Utility Services, Inc. (MMUS), are engaged in phased programs to update the safety documentation for the existing US Department of Energy (DOE)-owned facilities. The safety analysis of potential toxic hazards requires a methodology for evaluating human health effects of predicted toxic exposures. This report provides a consistent set of health effects and documents toxicity estimates corresponding to these health effects for some of the more important chemicals found within MMES and MMUS. The estimates are based on published toxicity information and apply to acute exposures for an ``average`` individual. The health effects (toxicological endpoints) used in this report are (1) the detection threshold; (2) the no-observed adverse effect level; (3) the onset of irritation/reversible effects; (4) the onset of irreversible effects; and (5) a lethal exposure, defined to be the 50% lethal level. An irreversible effect is defined as a significant effect on a person`s quality of life, e.g., serious injury. Predicted consequences are evaluated on the basis of concentration and exposure time.

  2. Physical, chemical and microbiological analysis of the water quality of Rawal Lake, Pakistan

    Directory of Open Access Journals (Sweden)

    Mehreen Hassan

    2014-06-01

    Full Text Available What better gift of nature would be than good quality water? In order to assess the quality of water of Rawal Lake, following research was carried out. Rawal lake is a source of drinking water supplied to many areas of Rawalpindi and Islamabad’ the capital city of Pakistan. Water of this lake is being highly polluted by the local communities alongside the lake through solid waste dumping. Samples of surface water were collected, tested and analyzed in the laboratory on the basis of physical, chemical and microbiological parameters. The results showed uncertainties in many of the selected parameters. Microbiological analysis revealed high contamination of E. coli, fecal coliform and total coliform in the samples proving it unfit for drinking. It was found that the concentration of all physical parameters such as nitrates, chloride, pH and conductivity were within the normal limits. The level of heavy metals like lead, iron, chromium etc. was also found low. Turbidity at some points exceeded the maximum acceptable limit as per WHO statement.

  3. A differential chemical element analysis of the metal poor Globular Cluster NGC 6397

    CERN Document Server

    Koch, Andreas

    2011-01-01

    We present chemical abundances in three red giants and two turn-off stars in the metal poor Galactic globular cluster (GC) NGC 6397 based on spectroscopy obtained with the MIKE high resolution spectrograph on the Magellan 6.5-m Clay telescope. Our results are based on a line-by-line differential abundance analysis relative to the well-studied red giant Arcturus and the Galactic halo field star Hip 66815. At a mean of -2.10 +/- 0.02 (stat.) +/- 0.07 (sys.) the differential iron abundance is in good agreement with other studies in the literature based on gf-values. As in previous, differential works we find a distinct departure from ionization equilibrium in that the abundances of Fe I and Fe II differ by ~0.1 dex, with opposite sign for the RGB and TO stars. The alpha-element ratios are enhanced to 0.4 (RGB) and 0.3 dex (TO), respectively, and we also confirm strong variations in the O, Na, and Al/Fe abundance ratios. Accordingly, the light-element abundance patterns in one of the red giants can be attributed ...

  4. 2D NMR barcoding and differential analysis of complex mixtures for chemical identification: the Actaea triterpenes.

    Science.gov (United States)

    Qiu, Feng; McAlpine, James B; Lankin, David C; Burton, Ian; Karakach, Tobias; Chen, Shao-Nong; Pauli, Guido F

    2014-04-15

    The interpretation of NMR spectroscopic information for structure elucidation involves decoding of complex resonance patterns that contain valuable molecular information (δ and J), which is not readily accessible otherwise. We introduce a new concept of 2D-NMR barcoding that uses clusters of fingerprint signals and their spatial relationships in the δ-δ coordinate space to facilitate the chemical identification of complex mixtures. Similar to widely used general barcoding technology, the structural information of individual compounds is encoded as a specifics pattern of their C,H correlation signals. Software-based recognition of these patterns enables the structural identification of the compounds and their discrimination in mixtures. Using the triterpenes from various Actaea (syn. Cimicifuga) species as a test case, heteronuclear multiple-bond correlation (HMBC) barcodes were generated on the basis of their structural subtypes from a statistical investigation of their δH and δC data in the literature. These reference barcodes allowed in silico identification of known triterpenes in enriched fractions obtained from an extract of A. racemosa (black cohosh). After dereplication, a differential analysis of heteronuclear single-quantum correlation (HSQC) spectra even allowed for the discovery of a new triterpene. The 2D barcoding concept has potential application in a natural product discovery project, allowing for the rapid dereplication of known compounds and as a tool in the search for structural novelty within compound classes with established barcodes. PMID:24673652

  5. Superconducting High-Resolution X-Ray Spectrometers for Chemical State Analysis of Dilute Samples

    International Nuclear Information System (INIS)

    Cryogenic X-ray spectrometers operating at temperatures below 1 K combine high energy resolution with broadband efficiency for X-ray energies up to 10 keV. They offer advantages for chemical state analysis of dilute samples by fluorescence-detected X-ray absorption spectroscopy (XAS) in cases where conventional Ge or Si(Li) detectors lack energy resolution and grating spectrometers lack detection efficiency. We are developing soft X-ray spectrometers based on superconducting Nb-Al-AlOx-Al-Nb tunnel junction (STJ) technology. X-rays absorbed in one of the superconducting electrodes generate excess charge carriers in proportion to their energy, thereby producing a measurable temporary increase in tunneling current. For STJ operation at the synchrotron, we have designed a two-stage adiabatic demagnetization refrigerator (ADR) with a cold finger that holds a 3 x 3 array of STJs inside the UHV sample chamber at a temperature of ∼0.1 K within ∼15 mm of a room temperature sample. Our STJ spectrometer can have an energy resolution below 10 eV FWHM for X-ray energies up to 1 keV, and has total count rate capabilities above 100,000 counts/s. We will describe detector performance in synchrotron-based X-ray fluorescence experiments and demonstrate its use for XAS on a dilute metal site in a metalloprotein

  6. PHYSICO CHEMICAL ANALYSIS OF PANCHAVAKTRA RAS: A HERBO-MINERAL FORMULATION

    Directory of Open Access Journals (Sweden)

    Bandari Srinivasulu

    2013-03-01

    Full Text Available Panchavaktra Ras is a rational combination of Rasadravyas and Kasthaushadhis prescribed in the management of Amavata. Panchavaktra rasa has been taken into consideration for its Pharmaceutical standardization through Standard Operative procedures. In pharmaceutical study, the drug has been prepared in 3 batches adopting Khalviya Rasayana method and physico chemical analysis was carried out on these batches. This formulation was analysed by using Inductively Coupled Plasma with Optical Emission Spectroscopy (ICPOES and found the major elements Hg, S, B, Fe, Cr, Cu, Ag, C, Pb, As from medicine. The heavy metals like As, Pb and Cd were almost within permissible limits. Organoleptic features of drug are found dark grey astringent taste and pungent odour which is made of the crude drugs within the standard range. The pH of compound was 8.93-8.99 and alkaline in nature. The phytochemical screening showed the presence of Alkaloids, Saponins, Flavanoids, Tanins and Tritepenoids in this drug. The Panchavaktra Ras was subjected to estimation of Microbial contamination which was within normal limits and it does not contain harmful microbes like Enterobacteriacea, E.coli, Salmonella species. Efforts have been made to fix the analytical standards of Panchavaktra ras, which were not found, reported till date.

  7. Chemical and microbiological analysis of public school water in Uberaba Municipality

    Directory of Open Access Journals (Sweden)

    Sérgio Marcos Sanches

    2015-07-01

    Full Text Available This study evaluated the quality of water consumed by schoolchildren in the city of Uberaba, relying upon chemical analyzes to determine the levels of free-residual chlorine and levels of chromium, copper, manganese, lead and cadmium. Microbiological analysis was also performed in order to determine total coliforms and Escherichia coli, using the values established by Ordinance n0 . 2914 of 2011 of the Ministry of Health as parameters for safe drinking water. Water samples were analyzed from the drinking fountains and kitchen faucets of eight public schools that serve children aged 0-5 years. Sampling was conducted quarterly from December 2011 to September 2012, resulting in four collections. The results revealed the presence of Escherichia coli and total coliforms above the valued permitted by legislation in more than 50% of the samples. It was also observed that concentrations of free-residual chlorine were below the minimum value required by law in nearly half of the samples analyzed. In relation to the concentration of metals, some samples had water contents of copper, cadmium, chromium, manganese and lead above the permissible levels. Statistical tests revealed that when analyzing the period of sampling, only the values for the concentrations of free-residual chlorine, chromium and lead showed no significant difference (p> 0.05. The results show the need for corrective actions at the water supply point for the school population, in addition to monitoring and controlling the quality of water for human consumption.

  8. Analysis of chemical composition and bioactive property evaluation of Indian propolis

    Institute of Scientific and Technical Information of China (English)

    R Thirugnanasampandan; Sayana Beena Raveendran; R Jayakumar

    2012-01-01

    Objective: To analyze the chemical composition and to evaluate the bioactive potential of hydroalocoholic extract of propolis. Methods: Ethanol extract of propolis was analyzed by GC-MS, HPTLC and HPLC methods and in vitro antioxidant, anticholinesterase and cytotoxicity assay were performed. Results: GC-MS analysis revealed the presence of fatty acids, alcohols, and quercetin. Quercetin was identified and quantified by HPTLC and HPLC methods. Dose dependent DPPH and hydroxyl radical scavenging activity of hydroalcoholic extract of propolis was calculated as 16.20 and 34.33 μg/mL respectively. Inhibition of lipid peroxidation was significant and the IC50 value was calculated as 55.56μg/mL. Anticholinesterase activity was less observed. The cytotoxic activity against both breast (MCF-7) and lung cancer (A543) cell lines were significant and the IC50 value was calculated as 10 and 13 μg/mL respectively. Conclusions:These findings showed that bioactive compounds present in propolis will alleviate many diseases and can be used for better human health.

  9. HE0107-5240, A Chemically Ancient Star.I. A Detailed Abundance Analysis

    CERN Document Server

    Christlieb, N; Korn, A J; Barklem, P S; Beers, T C; Bessell, M S; Karlsson, T; Mizuno-Wiedner, M

    2004-01-01

    We report a detailed abundance analysis for HE0107-5240, a halo giant with [Fe/H]_NLTE=-5.3. This star was discovered in the course of follow-up medium-resolution spectroscopy of extremely metal-poor candidates selected from the digitized Hamburg/ESO objective-prism survey. On the basis of high-resolution VLT/UVES spectra, we derive abundances for 8 elements (C, N, Na, Mg, Ca, Ti, Fe, and Ni), and upper limits for another 12 elements. A plane-parallel LTE model atmosphere has been specifically tailored for the chemical composition of {\\he}. Scenarios for the origin of the abundance pattern observed in the star are discussed. We argue that HE0107-5240 is most likely not a post-AGB star, and that the extremely low abundances of the iron-peak, and other elements, are not due to selective dust depletion. The abundance pattern of HE0107-5240 can be explained by pre-enrichment from a zero-metallicity type-II supernova of 20-25M_Sun, plus either self-enrichment with C and N, or production of these elements in the AG...

  10. Post-hoc Analysis on the R&D Capabilities of Chemical and Metallurgical Manufacturing

    Directory of Open Access Journals (Sweden)

    Herman Shah Anuar

    2013-09-01

    Full Text Available The purpose of this paper is to evaluate how internal R&D, external R&D, and patenting affects the behavior of foreign, local, and joint-venture companies operating in manufacturing companies in Malaysia. Different types of manufacturing companies may have different approach in applying their R&D capabilities and patenting activity. The construct of this paper is based on the post-hoc analysis in evaluating how internal R&D, external R&D, and patenting affects the behavior of foreign, local, and joint-venture companies operating in manufacturing companies. This research was conducted using survey questionnaires. 124 companies in chemical and metallurgical manufacturing companies participated in this survey. It was indicated that these three companies behave differently when dealing with internal R&D, external R&D, and patenting. It can be concluded that these three types of companies have a different perspective on applying internal R&D, external R&D, and patenting which is based on their different business strategic direction. It is suggested that in the near future, researchers should concentrate and other types of manufacturing companies or they can involve more sample size in getting better generalization on the behavior of these companies.

  11. Morphological and chemical analysis of different precipitates on mineral trioxide aggregate immersed in different fluids.

    Science.gov (United States)

    Han, Linlin; Okiji, Takashi; Okawa, Seigo

    2010-10-01

    The purpose of this study was to analyze the ultrastructures and chemical compositions of precipitates formed on mineral trioxide aggregate (MTA; White ProRoot MTA) immersed in distilled water (DW) or phosphate buffered saline (PBS), based on the attribution that MTA's bioactivity and sealing ability are influenced by its interaction with the external fluid environment. After 1 and 14 days of immersion, precipitates formed on MTA disks were analyzed using wavelength-dispersive X-ray spectroscopy electron probe microanalyzer with image observation function (SEM-EPMA; EPMA1601, Shimadzu, Kyoto, Japan), and Fourier transform-infrared (FT-IR) spectroscopy. On DW specimens, cubic-like crystals containing Ca, O, and C (17, 66, and 17 at% respectively) were produced. State analysis of calcium k(β)spectrum also revealed calcium hydroxide. On PBS specimens, acicular-spherical and lath-like crystals with Ca/P molar ratios of 1.42 and 1.58 respectively were produced. In conclusion, the precipitates formed on DW specimens were identified as calcium carbonate and calcium hydroxide primarily, whereas the precipitates on PBS specimens were inferred to be amorphous calcium phosphate. PMID:20823620

  12. Characterization of soil chemical properties of strawberry fields using principal component analysis

    Directory of Open Access Journals (Sweden)

    Gláucia Oliveira Islabão

    2013-02-01

    Full Text Available One of the largest strawberry-producing municipalities of Rio Grande do Sul (RS is Turuçu, in the South of the State. The strawberry production system adopted by farmers is similar to that used in other regions in Brazil and in the world. The main difference is related to the soil management, which can change the soil chemical properties during the strawberry cycle. This study had the objective of assessing the spatial and temporal distribution of soil fertility parameters using principal component analysis (PCA. Soil sampling was based on topography, dividing the field in three thirds: upper, middle and lower. From each of these thirds, five soil samples were randomly collected in the 0-0.20 m layer, to form a composite sample for each third. Four samples were taken during the strawberry cycle and the following properties were determined: soil organic matter (OM, soil total nitrogen (N, available phosphorus (P and potassium (K, exchangeable calcium (Ca and magnesium (Mg, soil pH (pH, cation exchange capacity (CEC at pH 7.0, soil base (V% and soil aluminum saturation(m%. No spatial variation was observed for any of the studied soil fertility parameters in the strawberry fields and temporal variation was only detected for available K. Phosphorus and K contents were always high or very high from the beginning of the strawberry cycle, while pH values ranged from very low to very high. Principal component analysis allowed the clustering of all strawberry fields based on variables related to soil acidity and organic matter content.

  13. Design analysis of 2,000 lb. JIB crane for chemical lab

    International Nuclear Information System (INIS)

    A 2,000 lbf jib crane is needed to replace an existing 1,000 lbf jib crane in the Chemical Lab (Building MO-733). The existing 1,000 lbf jib crane (to be replaced) has a 174 boom (I-beam). The crane is attached to the wall through two brackets (about 8 1/2-ft apart). The boom is attached to the lower bracket, and a supporting rod is attached to the upper bracket. The supporting rod is attached to the boom at about 8-ft from the free end. After preliminary studies and discussions, it was decided to construct the new jib crane from two perpendicular I-beams (L-shape) without a supporting rod. The crane is to be supported on the wall through the two lower existing brackets (about 5-ft apart). The boom is to be 20-ft long cantilever (the horizontal I-beam). The vertical I-beam is to be attached to the lower two existing brackets to support the jib crane to the wall. This construction is to be similar to another existing 1,000 lbf jib crane (L-shape) in the lab. The purpose of this document is to perform a design analysis for the proposed 2,000 lbf jib crane to determine suitable sizes of members and configuration of the new jib crane assembly. After construction, if the as-built assembly differs from the 2,000 lbf jib crane as proposed in this document, a revision of this analysis needs to be performed to confirm the acceptability of the as-built assembly

  14. Gaining improved chemical composition by exploitation of Compton-to-Rayleigh intensity ratio in XRF analysis.

    Science.gov (United States)

    Hodoroaba, Vasile-Dan; Rackwitz, Vanessa

    2014-07-15

    The high specificity of the coherent (Rayleigh), as well as incoherent (Compton) X-ray scattering to the mean atomic number of a specimen to be analyzed by X-ray fluorescence (XRF), is exploited to gain more information on the chemical composition. Concretely, the evaluation of the Compton-to-Rayleigh intensity ratio from XRF spectra and its relation to the average atomic number of reference materials via a calibration curve can reveal valuable information on the elemental composition complementary to that obtained from the reference-free XRF analysis. Particularly for matrices of lower mean atomic numbers, the sensitivity of the approach is so high that it can be easily distinguished between specimens of mean atomic numbers differing from each other by 0.1. Hence, the content of light elements which are "invisible" for XRF, particularly hydrogen, or of heavier impurities/additives in light materials can be calculated "by difference" from the scattering calibration curve. The excellent agreement between such an experimental, empirical calibration curve and a synthetically generated one, on the basis of a reliable physical model for the X-ray scattering, is also demonstrated. Thus, the feasibility of the approach for given experimental conditions and particular analytical questions can be tested prior to experiments with reference materials. For the present work a microfocus X-ray source attached on an SEM/EDX (scanning electron microscopy/energy dispersive X-ray spectroscopy) system was used so that the Compton-to-Rayleigh intensity ratio could be acquired with EDX spectral data for improved analysis of the elemental composition. PMID:24950635

  15. Design analysis of 2,000 lb JIB crane for chemical lab

    Energy Technology Data Exchange (ETDEWEB)

    ZIADA, H.H.

    1999-09-22

    A 2,000 lbf jib crane is needed to replace an existing 1,000 lbf jib crane in the Chemical Lab (Building MO-733). The existing 1,000 lbf jib crane (to be replaced) has a 174 boom (I-beam). The crane is attached to the wall through two brackets (about 8 1/2-ft apart). The boom is attached to the lower bracket, and a supporting rod is attached to the upper bracket. The supporting rod is attached to the boom at about 8-ft from the free end. After preliminary studies and discussions, it was decided to construct the new jib crane from two perpendicular I-beams (L-shape) without a supporting rod. The crane is to be supported on the wall through the two lower existing brackets (about 5-ft apart). The boom is to be 20-ft long cantilever (the horizontal I-beam). The vertical I-beam is to be attached to the lower two existing brackets to support the jib crane to the wall. This construction is to be similar to another existing 1,000 lbf jib crane (L-shape) in the lab. The purpose of this document is to perform a design analysis for the proposed 2,000 lbf jib crane to determine suitable sizes of members and configuration of the new jib crane assembly. After construction, if the as-built assembly differs from the 2,000 lbf jib crane as proposed in this document, a revision of this analysis needs to be performed to confirm the acceptability of the as-built assembly.

  16. Nano-structural and Nano-chemical analysis of dissimilar metal weld interfaces

    International Nuclear Information System (INIS)

    Dissimilar Metal Welds (DMWs) is generally applied to nuclear power plants for manufacturing and machining in structural components such as reactor pressure vessels and pressurizer nozzles. Alloy 152 is used frequently as filler metal in the manufacture of the DMW in light water reactors to join the low alloy steel pressure vessel nozzles and steam generator nozzles to nickel-based wrought alloy or austenitic stainless steel components. However, in recent years cracking phenomena has been observed in the welded joints. Concerns have been raised to the integrity and reliability in the joint transition zone due to the high susceptibility of the heat affected zone (HAZ) and the fusion boundary (FB) to stress corrosion cracking in combination with thermal aging. Since the material microstructure and chemical composition are key parameters affecting the stress corrosion cracking, improving the understanding of stress corrosion cracking at the FB region requires fundamental understanding of the unique microstructure of the FB region in DMW. Despite the potential degradation and consequent risk in the DMW, there is still a lack of the fundamental understanding of microstructure in the FB region, in particular the region containing unidentified band structures near the FB. The scale of the microstructure in modern metallic materials is becoming increasingly smaller. The 3-dimensional atom probe tomography (3D APT) has a truly quantitative analytical capability to characterize nanometer scale particles in metallic materials, thus its application to the microstructural analysis in multi-component metallic materials provides critical information on the mechanism of nanoscale microstructural evolution. The 3D APT is a microscope that allows the reconstruction of 3D 'atom maps'. These reconstructions can be interrogated and interpreted to determine the nanoscale chemistry of the material. Therefore, the current study is aiming at the establishment of detail procedure for the

  17. Chemical Attribution of Fentanyl Using Multivariate Statistical Analysis of Orthogonal Mass Spectral Data.

    Science.gov (United States)

    Mayer, Brian P; DeHope, Alan J; Mew, Daniel A; Spackman, Paul E; Williams, Audrey M

    2016-04-19

    Attribution of the origin of an illicit drug relies on identification of compounds indicative of its clandestine production and is a key component of many modern forensic investigations. The results of these studies can yield detailed information on method of manufacture, starting material source, and final product, all critical forensic evidence. In the present work, chemical attribution signatures (CAS) associated with the synthesis of the analgesic fentanyl, N-(1-phenylethylpiperidin-4-yl)-N-phenylpropanamide, were investigated. Six synthesis methods, all previously published fentanyl synthetic routes or hybrid versions thereof, were studied in an effort to identify and classify route-specific signatures. A total of 160 distinct compounds and inorganic species were identified using gas and liquid chromatographies combined with mass spectrometric methods (gas chromatography/mass spectrometry (GC/MS) and liquid chromatography-tandem mass spectrometry-time of-flight (LC-MS/MS-TOF)) in conjunction with inductively coupled plasma mass spectrometry (ICPMS). The complexity of the resultant data matrix urged the use of multivariate statistical analysis. Using partial least-squares-discriminant analysis (PLS-DA), 87 route-specific CAS were classified and a statistical model capable of predicting the method of fentanyl synthesis was validated and tested against CAS profiles from crude fentanyl products deposited and later extracted from two operationally relevant surfaces: stainless steel and vinyl tile. This work provides the most detailed fentanyl CAS investigation to date by using orthogonal mass spectral data to identify CAS of forensic significance for illicit drug detection, profiling, and attribution. PMID:27010913

  18. A new technique to assess dermal absorption of chemical vapor in vitro by thermogravimetric analysis (TGA)

    OpenAIRE

    Rauma, Matias

    2008-01-01

    There is a huge lack of dermal uptake data for chemicals, and it is frequent with large variations in reported permeability coefficients for chemicals with more than one data set, showing the need for a new and standardized in vitro method. The overall aim of this thesis was to develop the new method of measuring dermal absorption of chemical vapor using the TGA method. Assessment of dermal absorption by TGA (Study I) Round pieces (ø8 mm) of pig epidermis were placed on ...

  19. Analysis of thermal-chemical interactions at the ceramic mould – molten nickel alloy interface

    OpenAIRE

    J. Śleziona; J. Michalska; F. Binczyk

    2010-01-01

    A model of thermal-chemical interactions at the ceramic mould – molten nickel alloy interface was described. Studies were carried out on mould coated with a layer of modifier based on zirconium silicate and cobalt aluminate. The thermodynamic calculations indicated thepossibility of chemical reactions taking place between the chemically active nickel alloy constituents (Al, Ti, Hf, Ta and Nb) andcomponents of the modifying coating. The result of such interactions is possible formation on the ...

  20. Characterization of a Copper mineral from Rio Grande do Sul (RS, Brazil) by Moessbauer spectroscopy and chemical analysis

    International Nuclear Information System (INIS)

    A sample from a copper-based mineral is analysed by Moessbauer spectroscopy. The results are compared with those form X-ray diffraction and microscopic analyses. A graphic correlation between the areas in the chalcopyrite spectra and the copper contents determined by chemical analysis is also made. (C.L.B.)

  1. Chemical Analysis of High Burn-up PuO2 Fuel. II Results on Dragon-Fuel. RCN Report

    International Nuclear Information System (INIS)

    The results of a chemical analysis with respect to isotopic composition and total content of the elements Zr, Mo, Ru, Cs, Nd, Pm, Sm, Eu and Pu in a batch of irradiated pyro-carbon / silicon-carbide-coated PuO2 fuel particles are reported and discussed. (author)

  2. Lessons learned from non-medical industries: root cause analysis as culture change at a chemical plant

    OpenAIRE

    Carroll, J; J. Rudolph; Hatakenaka, S

    2002-01-01

    

 Root cause analysis was introduced to a chemical plant as a way of enhancing performance and safety, exemplified by the investigation of an explosion. The cultural legacy of the root cause learning intervention was embodied in managers' increased openness to new ideas, individuals' questioning attitude and disciplined thinking, and a root cause analysis process that provided continual opportunities to learn and improve. Lessons for health care are discussed, taking account of differences b...

  3. Constraints on the Global-scale Chemical Weathering State of Mars From TES Results Based on Spectral Analysis of Chemically Weathered Basalts

    Science.gov (United States)

    Michalski, J. R.; Kraft, M. D.; Sharp, T. G.; Christensen, P. R.

    2005-12-01

    mineralogy from thermal infrared data; weathering serves to bias igneous interpretations toward rocks of higher silica and alkali contents. Trends observed in the spectral analysis of chemically weathered CRBG rock surfaces could explain some of the spectral trends observed at Mars, suggesting that martian dark region basalts have been chemically weathered under consistently low-water, or only episodically wet surface conditions.

  4. Simultaneous Quantitative and Chemical Fingerprint Analysis of Receptaculum Nelumbinis Based on HPLC-DAD-MS Combined with Chemometrics.

    Science.gov (United States)

    Liu, Haitao; Liu, Jiushi; Zhang, Jin; Qi, Yaodong; Jia, Xiaoguang; Zhang, Bengang; Xiao, Peigen

    2016-04-01

    A rapid and sensitive method based on HPLC-DAD-MS was developed for quantitative analysis of two flavonoids and chemical fingerprint analysis to evaluate the quality of Receptaculum Nelumbinis. The analysis was conducted on a Poroshell 120 C18 column (100 × 4.6 mm, 2.7 μm) with 0.2% formic acid buffer solution and methanol as mobile phases with gradient elution. This method displayed good linearity with R(2) at >0.9999 and limits of quantity <0.37 μg mL(-1). Relative standard deviation values for intra- and interday precision were <0.82 and 1.03%, respectively. The mean recovery of hyperoside was 95.54% and of isoquercitrin was 92.10%. Hyperoside and isoquercitrin were determined simultaneously, and 12 peaks in the chemical fingerprint were identified. The chemometric methods, including similarity analysis, hierarchical clustering analysis and principal component analysis, were applied to distinguish 11 batches of Receptaculum Nelumbinis samples. The above results could validate each other and successfully divide these samples into two groups. Moreover, hyperoside and isoquercitrin could be selected as chemical markers to evaluate the quality of Receptaculum Nelumbinis from different localities. This study demonstrated that the developed method was a powerful and beneficial tool to carry out the quality control of Receptaculum Nelumbinis. PMID:26921895

  5. Analysis of chemical profiles of insect adhesion secretions by gas chromatography–mass spectrometry

    International Nuclear Information System (INIS)

    Highlights: • Adhesion secretions of desert locust analyzed by GC–MS. • Insect secretions are composed of apolar and polar constituents. • Sampling simplified with contact SPME as compared to solvent sampling. • Thin-film SPME-GC–MS revealed complex alkane patterns for insect secretions. • Differences in tarsal (feet) secretions and samples from tibiae (upper legs) identified. - Abstract: This article reports on the chemical analysis of molecular profiles of tarsal secretions of the desert locust Schistocerca gregaria (Forsskål, 1775) by gas chromatography hyphenated with quadrupol mass spectrometry (GC–MS) as well as 1H-nuclear magnetic resonance (1H NMR) spectroscopy. Special focus of this study was to elaborate on sampling methods which enable selective microscale extraction of insect secretions in a spatially controlled manner, in particular tarsal adhesive secretions and secretions located on cuticle surfaces at the tibia. Various solvent sampling procedures and contact solid-phase microextraction (SPME) methods were compared in terms of comprehensiveness and extraction efficiencies as measured by signal intensities in GC–MS. Solvent sampling with water as extraction solvent gave access to the elucidation of chemical profiles of polar compound classes such as amino acids and carbohydrates, but is extremely tedious. Contact SPME on the other hand can be regarded as a simplified and more elegant alternative, in particular for the lipophilic compound fraction. Many proteinogenic amino acids and ornithine as well as carbohydrate monomers arabinose, xylose, glucose, and galactose were detected in tarsal secretions after acid hydrolysis of aqueous extracts. Qualitatively similar but quantitatively significantly different molecular profiles were found for the lipid fraction which contained mainly n-alkanes and internally branched monomethyl-, dimethyl-, and trimethyl-alkanes in the C23–C49 range as well as long chain fatty acids and aldehydes

  6. Analysis of chemical profiles of insect adhesion secretions by gas chromatography–mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Reitz, Manuela [Institute of Organic Chemistry, University of Tübingen, Auf der Morgenstelle 8, 72076 Tübingen (Germany); Gerhardt, Heike [Institute of Pharmaceutical Sciences, University of Tübingen, Auf der Morgenstelle 8, 72076 Tübingen (Germany); Schmitt, Christian; Betz, Oliver [Institute of Evolution and Ecology, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen (Germany); Albert, Klaus, E-mail: klaus.albert@uni-tuebingen.de [Institute of Organic Chemistry, University of Tübingen, Auf der Morgenstelle 8, 72076 Tübingen (Germany); Lämmerhofer, Michael, E-mail: michael.laemmerhofer@uni-tuebingen.de [Institute of Pharmaceutical Sciences, University of Tübingen, Auf der Morgenstelle 8, 72076 Tübingen (Germany)

    2015-01-07

    Highlights: • Adhesion secretions of desert locust analyzed by GC–MS. • Insect secretions are composed of apolar and polar constituents. • Sampling simplified with contact SPME as compared to solvent sampling. • Thin-film SPME-GC–MS revealed complex alkane patterns for insect secretions. • Differences in tarsal (feet) secretions and samples from tibiae (upper legs) identified. - Abstract: This article reports on the chemical analysis of molecular profiles of tarsal secretions of the desert locust Schistocerca gregaria (Forsskål, 1775) by gas chromatography hyphenated with quadrupol mass spectrometry (GC–MS) as well as {sup 1}H-nuclear magnetic resonance ({sup 1}H NMR) spectroscopy. Special focus of this study was to elaborate on sampling methods which enable selective microscale extraction of insect secretions in a spatially controlled manner, in particular tarsal adhesive secretions and secretions located on cuticle surfaces at the tibia. Various solvent sampling procedures and contact solid-phase microextraction (SPME) methods were compared in terms of comprehensiveness and extraction efficiencies as measured by signal intensities in GC–MS. Solvent sampling with water as extraction solvent gave access to the elucidation of chemical profiles of polar compound classes such as amino acids and carbohydrates, but is extremely tedious. Contact SPME on the other hand can be regarded as a simplified and more elegant alternative, in particular for the lipophilic compound fraction. Many proteinogenic amino acids and ornithine as well as carbohydrate monomers arabinose, xylose, glucose, and galactose were detected in tarsal secretions after acid hydrolysis of aqueous extracts. Qualitatively similar but quantitatively significantly different molecular profiles were found for the lipid fraction which contained mainly n-alkanes and internally branched monomethyl-, dimethyl-, and trimethyl-alkanes in the C23–C49 range as well as long chain fatty acids and

  7. Zinc injection implementation process at EDF: risk analysis, chemical specifications and operating procedures

    International Nuclear Information System (INIS)

    's strategy and the different measures adopted by EDF to provide the necessary tools to the French units : zinc injection procedures, risk analysis, chemistry -radiochemistry surveillance programs, and chemical specifications. This work can be useful for other utilities, assisting them in optimizing and/or implementing the zinc injection in the most suitable conditions, which would help to obtain the expected results in the current and the future reactors. (author)

  8. Chemical composition analysis of simulated waste glass T10-G-16A

    Energy Technology Data Exchange (ETDEWEB)

    Fox, K. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-08-01

    In this report, SRNL provides chemical composition analyses of a simulated LAW glass designated T10-G-16A.The measured chemical composition data are reported and compared with the targeted values for each component. No issues were identified in reviewing the analytical data.

  9. Introduction to Chemical Engineering Reactor Analysis: A Web-Based Reactor Design Game

    Science.gov (United States)

    Orbey, Nese; Clay, Molly; Russell, T.W. Fraser

    2014-01-01

    An approach to explain chemical engineering through a Web-based interactive game design was developed and used with college freshman and junior/senior high school students. The goal of this approach was to demonstrate how to model a lab-scale experiment, and use the results to design and operate a chemical reactor. The game incorporates both…

  10. Analysis of determination modalities concerning the exposure and emission limits values of chemical and radioactive substances

    International Nuclear Information System (INIS)

    This document presents the generic approach adopted by various organizations for the determination of the public exposure limits values to chemical and radioactive substances and for the determination of limits values of chemical products emissions by some installations. (A.L.B.)

  11. Chemical speciation analysis and environmental behaviour of 127I and 12

    International Nuclear Information System (INIS)

    Chemical speciation analysis of 129I and 127I as iodide, iodate and total inorganic iodine in seawater samples from the Baltic Proper, Skagerrak and Kattegat has been carried out. The important findings of this study are that the reduction of iodate and oxidation of iodide in Skagerrak and Kattegat may be a slow process while along the Baltic Sea surface water reduction of iodate is a relatively fast process. Although suboxic or anoxic condition are encountered in some of the Baltic Sea deep basins, the concentration of 129IO3- increases with water depth indicating that the reduction of iodate in the oxygen deficient bottom water of the Baltic Sea is a slow process. Iodine chemical speciation analysis (as iodide, iodate and total iodine including inorganic and organic iodine species) in lake water samples collected from Denmark and southern Sweden has been carried out. Destruction of organic iodine was performed by alkaline oxidation using NaOH - NaClO at 100 deg. C and anion exchange chromatography was used for separation of iodide and iodate. Iodine-129 concentrations in the lakes ranged from 1.3 - 12.8 x109 at/L and show elevated concentrations in lakes located in southwest Jutland (Denmark), near the North Sea. Except the Skaersoe Lake, were the organic iodine - 127 accounts for 50% of the total iodine, iodide (both 129I and 127I) is the predominant species form in surface water of the studied lakes. An investigation was conducted in order to quantify the total aquatic iodine (129I and 127I as inorganic and organic iodine) from fresh water and seawater samples by adsorption onto activated charcoal and DEAE 32 cellulose followed by alkaline digestion or combustion. The results show that iodide from freshwater samples can easily be adsorbed onto activated charcoal. The sorption was not affected by the pH. The absorption capacity of iodate is low and reduces quickly when its concentration increases. Compared with activated charcoal, DEAE 32 cellulose showed a

  12. Dynamic processes of conceptual change: Analysis of constructing mental models of chemical equilibrium

    Science.gov (United States)

    Chiu, Mei-Hung; Chou, Chin-Cheng; Liu, Chia-Ju

    2002-10-01

    The purpose of this study was to investigate students' mental models of chemical equilibrium using dynamic science assessments. Research in chemical education has shown that students at various levels have misconceptions about chemical equilibrium. According to Chi's theory of conceptual change, the concept of chemical equilibrium has constraint-based features (e.g., random, simultaneous, uniform activities) that might prevent students from deeply understanding the nature of the concept of chemical equilibrium. In this study, we examined how students learned and constructed their mental models of chemical equilibrium in a cognitive apprenticeship context. Thirty 10th-grade students participated in the study: 10 in a control group and 20 in a treatment group. Both groups were presented with a series of hands-on chemical experiments. The students in the treatment group were instructed based on the main features of cognitive apprenticeship (CA), such as coaching, modeling, scaffolding, articulation, reflection, and exploration. However, the students in the control group (non-CA group) learned from the tutor without explicit CA support. The results revealed that the CA group significantly outperformed the non-CA group. The students in the CA group were capable of constructing the mental models of chemical equilibrium - including dynamic, random activities of molecules and interactions between molecules in the microworld - whereas the students in the non-CA group failed to construct similar correct mental models of chemical equilibrium. The study focuses on the process of constructing mental models, on dynamic changes, and on the actions of students (such as self-monitoring/self-correction) who are learning the concept of chemical equilibrium. Also, we discuss the implications for science education.

  13. In situ chemical state analysis of buried polymer/metal adhesive interface by hard X-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Highlights: • Chemical state analysis of the buried rubber/brass interface is conducted by HAXPES. • Ultrathin rubber films are prepared on the brass surface by two methods. • A high density of Cu2S is found on the rubber side of the buried adhesive layer. • The chemical states of the buried and exposed interfaces are compared. - Abstract: Chemical state analysis of adhesive interfaces is important to understand an adhesion mechanism between two different materials. Although photoelectron spectroscopy (PES) is an ideal tool for such an analysis, the adhesive interfaces must be exposed to the surface because PES is essentially a surface sensitive technique. However, an in situ observation is possible by hard X-ray PES (HAXPES) owing to its large probing depth. In the present study, HAXPES is applied to investigate the adhesive interface between rubber and brass without exposing the interface. It is demonstrated that copper sulfides formed at the buried rubber/brass interface are distinguished from S-containing species in the rubber overlayer. The chemical state of the buried interface is compared with that of the “exposed” interface prepared by so-called a filter-paper method

  14. Practical chemical analysis of Pt and Pd based heterogeneous catalysts with hard X-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Highlights: •Hard X-ray photoelectron spectroscopy (HAXPES) enables interface analysis of catalyst. •HAXPES enables overall analysis of porous film of Pt-doped CeO2 and related catalyst. •HAXPES enables analysis of trace elements for Pd and Pt3Ni nanoparticle catalysts. -- Abstract: Interfacial properties including configuration, porosity, chemical states, and atomic diffusion greatly affect the performance of supported heterogeneous catalysts. Hard X-ray photoelectron spectroscopy (HAXPES) can be used to analyze the interfaces of heterogeneous catalysts because of its large information depth of more than 20 nm. We use HAXPES to examine Pt-doped CeO2 and related thin film catalysts evaporated on Si, carbon, and carbon nanotube substrates, because Pt-doped CeO2 has great potential as a noble metal-based heterogeneous catalyst for fuel cells. The HAXPES measurements clarify that the dopant material, substrate material, and surface pretreatment of substrate are important parameters that affect the interfacial properties of Pt-doped CeO2 and related thin film catalysts. Another advantage of HAXPES measurement of heterogeneous catalysts is that it can be used for chemical analysis of trace elements by detecting photoelectrons from deep core levels, which have large photoionization cross-sections in the hard X-ray region. We use HAXPES for chemical analysis of trace elements in Pd nanoparticle catalysts immobilized on sulfur-terminated substrates and Pt3Ni nanoparticle catalysts enveloped by dendrimer molecules

  15. Chemical analysis of sewage sludge of southern sewerage treatment plant (SSTP) Hyderabad for achieving sustainable development in sector of agriculture

    International Nuclear Information System (INIS)

    A study on the chemical analysis of sewage sludge of southern sewerage treatment plant (SSPP) Hyderabad was studied. Chemical analysis on sludge samples collected form the waste stabilization for different micro-nutrients (essential manures, nitrogen, phosphorus, potassium, calcium and magnesium) were conducted in year 1999-2000. These nutrients and metal were detected by reliable analytical method i.e. Kjeldahls method and Atomic Absorption Spectrophotometer. The analysis showed that sewage sludge contained sufficient quantity of primary and secondary nutrients, hence sewage sludge could be utilized as a natural fertilizer. This will not only solve the disposal problem but it would also be environmentally safer way of providing regulators to the plants. (author)

  16. Application of dynamic Bayesian network to risk analysis of domino effects in chemical infrastructures

    International Nuclear Information System (INIS)

    A domino effect is a low frequency high consequence chain of accidents where a primary accident (usually fire and explosion) in a unit triggers secondary accidents in adjacent units. High complexity and growing interdependencies of chemical infrastructures make them increasingly vulnerable to domino effects. Domino effects can be considered as time dependent processes. Thus, not only the identification of involved units but also their temporal entailment in the chain of accidents matter. More importantly, in the case of domino-induced fires which can generally last much longer compared to explosions, foreseeing the temporal evolution of domino effects and, in particular, predicting the most probable sequence of accidents (or involved units) in a domino effect can be of significance in the allocation of preventive and protective safety measures. Although many attempts have been made to identify the spatial evolution of domino effects, the temporal evolution of such accidents has been overlooked. We have proposed a methodology based on dynamic Bayesian network to model both the spatial and temporal evolutions of domino effects and also to quantify the most probable sequence of accidents in a potential domino effect. The application of the developed methodology has been demonstrated via a hypothetical fuel storage plant. - Highlights: • A Dynamic Bayesian Network methodology has been developed to model domino effects. • Considering time-dependencies, both spatial and temporal evolutions of domino effects have been modeled. • The concept of most probable sequence of accidents has been proposed instead of the most probable combination of accidents. • Using backward analysis, the most vulnerable units have been identified during a potential domino effect. • The proposed methodology does not need to identify a unique primary unit (accident) for domino effect modeling

  17. Abundance analysis of an extended sample of open clusters: A search for chemical inhomogeneities

    Science.gov (United States)

    Reddy, Arumalla B. S.; Giridhar, Sunetra; Lambert, David L.

    We have initiated a program to explore the presence of chemical inhomogeneities in the Galactic disk using the open clusters as ideal probes. We have analyzed high-dispersion echelle spectra (R ≥ 55,000) of red giant members for eleven open clusters to derive abundances for many elements. The membership to the cluster has been confirmed through their radial velocities and proper motions. The spread in temperatures and gravities being very small among the red giants, nearly the same stellar lines were employed thereby reducing the random errors. The errors of average abundance for the cluster were generally in 0.02 to 0.07 dex range. Our present sample covers galactocentric distances of 8.3 to 11.3 kpc and an age range of 0.2 to 4.3 Gyrs. Our earlier analysis of four open clusters (Reddy A.B.S. et al., 2012, MNRAS, 419,1350) indicate that abundances relative to Fe for elements from Na to Eu are equal within measurement uncertainties to published abundances for thin disk giants in the field. This supports the view that field stars come from disrupted open clusters. In the enlarged sample of eleven open clusters we find cluster to cluster abundance variations for some s- and r- process elements, with certain elements such as Zr and Ba showing large variation. These differences mark the signatures that these clusters had formed under different environmental conditions (Type II SN, Type Ia SN, AGB stars or a mixture of any of these) unique to the time and site of formation. These eleven clusters support the widely held impression that there is an abundance gradient such that the metallicity [Fe/H] at the solar galactocentric distance decreases outwards at about -0.1 dex per kpc.

  18. Applying Chemical Imaging Analysis to Improve Our Understanding of Cold Cloud Formation

    Science.gov (United States)

    Laskin, A.; Knopf, D. A.; Wang, B.; Alpert, P. A.; Roedel, T.; Gilles, M. K.; Moffet, R.; Tivanski, A.

    2012-12-01

    The impact that atmospheric ice nucleation has on the global radiation budget is one of the least understood problems in atmospheric sciences. This is in part due to the incomplete understanding of various ice nucleation pathways that lead to ice crystal formation from pre-existing aerosol particles. Studies investigating the ice nucleation propensity of laboratory generated particles indicate that individual particle types are highly selective in their ice nucleating efficiency. This description of heterogeneous ice nucleation would present a challenge when applying to the atmosphere which contains a complex mixture of particles. Here, we employ a combination of micro-spectroscopic and optical single particle analytical methods to relate particle physical and chemical properties with observed water uptake and ice nucleation. Field-collected particles from urban environments impacted by anthropogenic and marine emissions and aging processes are investigated. Single particle characterization is provided by computer controlled scanning electron microscopy with energy dispersive analysis of X-rays (CCSEM/EDX) and scanning transmission X-ray microscopy with near edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS). A particle-on-substrate approach coupled to a vapor controlled cooling-stage and a microscope system is applied to determine the onsets of water uptake and ice nucleation including immersion freezing and deposition ice nucleation as a function of temperature (T) as low as 200 K and relative humidity (RH) up to water saturation. We observe for urban aerosol particles that for T > 230 K the oxidation level affects initial water uptake and that subsequent immersion freezing depends on particle mixing state, e.g. by the presence of insoluble particles. For T air parcel.

  19. Phase development in conventional and active belite cement pastes by Rietveld analysis and chemical constraints

    International Nuclear Information System (INIS)

    High belite cements may be an alternative to reduce CO2 emissions. Although CO2 emissions may be depleted up to 10%, unfortunately, the hydration reactivity of belite phases is slow which leads to low mechanical strengths at early ages. In order to enhance their hydraulic reactivity, the activation of these cements by doping with alkaline oxides has been proposed. Here, we have synthesised a laboratory belite clinker without activation (47 wt.% of β-C2S and 19 wt.% of αH'-C2S) and two alkaline oxide activated clinkers (one with 13 wt.% of β-C2S, 24 wt.% of αH'-C2S and 19 wt.% of α-C2S; and the second with 12 wt.% of β-C2S, 42 wt.% of αH'-C2S and 5 wt.% of α-C2S). We have also developed a methodology to analyse quantitatively the phase evolution of cement pastes and we have applied it to these high belite cements. Rietveld quantitative phase analysis of synchrotron X-ray powder diffraction data, together with chemical constraints, is used to determine the phase development up to 1 year of hydration in the belite cement pastes. β-C2S almost does not react during the first 3 months, meanwhile αH'-C2S reacts on average more than 50% in the same period. Moreover, the degree of reaction of α-C2S is slightly larger (on average about 70% after three months) than that of αH'-C2S. Full phase analyses are reported and discussed including the time evolution of amorphous phases and free water.

  20. Mass, energy, and exergy balance analysis of chemical looping with oxygen uncoupling (CLOU) process

    International Nuclear Information System (INIS)

    Highlights: • A CLOU reactor system using a CuO-based OC and coal as fuel is analyzed. • Possible operational regions for the chosen OC are identified. • Different heat balance scenarios are investigated. • The second-law efficiency of the system is evaluated. • Various design aspects and process modelling relationships are discussed. - Abstract: Chemical looping with oxygen uncoupling (CLOU) is a promising concept for efficient combustion of solid fuels with an inherent capture of the greenhouse gas CO2. This paper presents a CLOU process scheme with stoichiometric mass, energy, and exergy balances. A CLOU reactor system using medium volatile bituminous coal as fuel and silica-supported CuO as an oxygen carrier is analyzed. The analysis includes the estimation of various design and operational parameters, thermal considerations, and evaluation of the overall performance. The operation of a reactor system of two interacting circulating fluidized beds (CFBs) is greatly influenced by the hydrodynamics. For the CuO oxygen carrier, the hydrodynamic operating range appeared feasible considering the maximum solid circulation rates in current CFB boilers. Depending upon the reactor temperatures, oxygen carrier inventories of 400–680 kg/MW in the system were found necessary for stoichiometric combustion of the fuel. The temperature difference between the reactors should not exceed 50 °C, as otherwise, problems may arise with the heat balance. Exergetic efficiencies in the range of 63–70% were obtained for different combinations of relevant design parameters. It is evident that the possible operating conditions in the system are closely related to the properties of the chosen oxygen carrier. However, the calculation procedure and design criteria presented here are applicable to any oxygen carrier to be used in the process

  1. Measurement standards and the general problem of reference points in chemical analysis

    International Nuclear Information System (INIS)

    Besides the measurement standards available in general metrology in the form of the realisations of the units of measurement, measurement standards of chemical composition are needed for the vast field of chemical measurement (measurements of the chemical composition), because it is the main aim of such measurements to quantify non-isolated substances, often in complicated matrices, to which the 'classical' measurement standards and their lower- level derivatives are not directly applicable. At present, material artefacts as well as standard measurement devices serve as chemical measurement standards. These are measurement standards in the full metrological sense only, however, if they are firmly linked to the SI unit in which the composition represented by the standard is expressed. This requirement has the consequence that only a very restricted number of really reliable chemical measurement standards exist at present. Since it is very difficult and time consuming to increase this number substantially and, on the other hand, reliable reference points are increasingly needed for all kinds of chemical measurements, primary methods of measurement and high-level reference measurements will play an increasingly important role for the establishment of worldwide comparability and hence mutual acceptance of chemical measurement results. (author)

  2. Particle Generation by Laser Ablation in Support of Chemical Analysis of High Level Mixed Waste from Plutonium Production Operations

    International Nuclear Information System (INIS)

    Investigate particles produced by laser irradiation and their analysis by Laser Ablation Inductively Coupled Plasma Mass Spectroscopy (LA/ICP-MS), with a view towards optimizing particle production for analysis of high level waste materials and waste glass. LA/ICP-MS has considerable potential to increase the safety and speed of analysis required for the remediation of high level wastes from cold war plutonium production operations. In some sample types, notably the sodium nitrate-based wastes at Hanford and elsewhere, chemical analysis using typical laser conditions depends strongly on the details of sample history composition in a complex fashion, rendering the results of analysis uncertain. Conversely, waste glass materials appear to be better behaved and require different strategies to optimize analysis

  3. CRITIC2: A program for real-space analysis of quantum chemical interactions in solids

    Science.gov (United States)

    Otero-de-la-Roza, A.; Johnson, Erin R.; Luaña, Víctor

    2014-03-01

    We present CRITIC2, a program for the analysis of quantum-mechanical atomic and molecular interactions in periodic solids. This code, a greatly improved version of the previous CRITIC program (Otero-de-la Roza et al., 2009), can: (i) find critical points of the electron density and related scalar fields such as the electron localization function (ELF), Laplacian, … (ii) integrate atomic properties in the framework of Bader’s Atoms-in-Molecules theory (QTAIM), (iii) visualize non-covalent interactions in crystals using the non-covalent interactions (NCI) index, (iv) generate relevant graphical representations including lines, planes, gradient paths, contour plots, atomic basins, … and (v) perform transformations between file formats describing scalar fields and crystal structures. CRITIC2 can interface with the output produced by a variety of electronic structure programs including WIEN2k, elk, PI, abinit, Quantum ESPRESSO, VASP, Gaussian, and, in general, any other code capable of writing the scalar field under study to a three-dimensional grid. CRITIC2 is parallelized, completely documented (including illustrative test cases) and publicly available under the GNU General Public License. Catalogue identifier: AECB_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AECB_v2_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: yes No. of lines in distributed program, including test data, etc.: 11686949 No. of bytes in distributed program, including test data, etc.: 337020731 Distribution format: tar.gz Programming language: Fortran 77 and 90. Computer: Workstations. Operating system: Unix, GNU/Linux. Has the code been vectorized or parallelized?: Shared-memory parallelization can be used for most tasks. Classification: 7.3. Catalogue identifier of previous version: AECB_v1_0 Journal reference of previous version: Comput. Phys. Comm. 180 (2009) 157 Nature of problem: Analysis of quantum-chemical

  4. Analysis of Physical, Chemical and Microbiological Pollution in one Right Click

    International Nuclear Information System (INIS)

    Current researches on the topic of indoor air pollution are moving towards expertise and prevention. Therefore it seems so critical to invest in the area of expertise and create a measuring device performing chemical, physical and bacteriological analysis in one click. Our choice of development towards this system of information management is oriented towards a modular system which can simultaneously transmit on real-time the analysis in the internet. Our production work has used several solutions and analyzed several possible methods such as microprocessor that has shown its reliability. The electronic system worked well even with some problems solved at the level of detection of particles α, β and γ. The solution NO-IP as for the transfer of data over the Internet has been successfully tested. In the same way we have been constrained to achieve measurement campaigns to verify the ability of the device to give consistent values. These campaigns were conducted on the Beaulieu of the University of Rennes 1, given the size of the site; it gives us a fairly comprehensive range of situations. These measurement campaigns extended for several months, with the purpose of comparing and analyzing the various results. These campaigns offer an opportunity of testing the operation of the aircraft and assessing the performance, knowing that all measures were compared to the device certified EN (Gasman). For the development of our device, we specify the direction and scope of the study area, analyze the existing level of detection performed and technical data manipulated, obtain a comprehensive description of the electronic system and reach a reasoned choice of a solution type of development. This allowed us to develop a multifunction prototype which objective is to control the quality of indoor air pollution in habitations. This device admits the same principle as product modem M2M (Machine to Machine). Through processes M2M, machinery (measuring instruments (device) and air

  5. Sampling and analysis of chemical element concentration distribution in rock units and orebodies

    Directory of Open Access Journals (Sweden)

    F. P. Agterberg

    2012-01-01

    Full Text Available Existing sampling techniques applied within known orebodies, such as sampling along mining drifts, yield element concentration values for larger blocks of ore if they are extended into their surroundings. The resulting average concentration values have relatively small "extension variance". These techniques can be used for multifractal modeling as well as ore reserve estimation approaches. Geometric probability theory can aid in local spatial covariance modeling. It provides information about increase of variability of element concentration over short distances exceeding microscopic scale. In general, the local clustering of ore crystals results in small-scale variability known as the "nugget effect". Parameters to characterize spatial covariance estimated from ore samples subjected to chemical analysis for ore reserve estimation may not be valid at local scale because of the nugget effect. The novel method of local singularity mapping applied within orebodies provides new insights into the nature of the nugget effect. Within the Pulacayo orebody, Bolivia, local singularity for zinc is linearly related with logarithmically transformed concentration value. If there is a nugget effect, moving averages resulting from covariance models or estimated by other methods that have a smoothing effect, such as kriging, can be improved by incorporating local singularities indicating local element enrichment or depletion. Although there have been many successful applications of the multifractal binomial/p model, its application within the Pulacayo orebody results in inconsistencies, indicating some shortcomings of this relatively simple approach. Local singularity analysis and universal multifractal modeling are two promising new approaches to improve upon results obtained by commonly used geostatistical techniques and use of the binomial/p model. All methods in this paper are illustrated using a single example (118 Pulacayo zinc values, and

  6. Thermodynamic analysis of chemical compatibility of several compounds with Fe-Cr-Al alloys

    Science.gov (United States)

    Misra, Ajay K.

    1993-01-01

    Chemical compatibility between Fe-19.8Cr-4.8Al (weight percent), which is the base composition for the commercial superalloy MA956, and several carbides, borides, nitrides, oxides, and silicides was analyzed from thermodynamic considerations. The effect of addition of minor alloying elements, such as Ti, Y, and Y2O3, to the Fe-Cr-Al alloy on chemical compatibility between the alloy and various compounds was also analyzed. Several chemically compatible compounds that can be potential reinforcement materials and/or interface coating materials for Fe-Cr-Al based composites were identified.

  7. Thermodynamic analysis of chemical compatibility of several reinforcement materials with niobium aluminides. Final contractor report

    International Nuclear Information System (INIS)

    Chemical compatibility of several reinforcement materials with three niobium aluminides, Nb3Al, Nb2Al, and NbAl3, were examined from thermodynamic considerations. The reinforcement materials considered in this study include carbides, borides, nitrides, oxides, silicides, and Engel-Brewer compounds. Thermodynamics of the Nb-Al system were reviewed and activities of Nb and Al were derived at desired calculation temperatures. Criteria for chemical compatibility between the reinforcement material and Nb-Al compounds have been defined and several chemically compatible reinforcement materials have been identified

  8. Thermodynamic analysis of chemical compatibility of ceramic reinforcement materials with niobium aluminides

    Science.gov (United States)

    Misra, Ajay K.

    1990-01-01

    Chemical compatibility of several reinforcement materials with three niobium aluminides, Nb3Al, Nb2Al, and NbAl3, were examined from thermodynamic considerations. The reinforcement materials considered in this study include carbides, borides, nitrides, oxides, silicides, and Engel-Brewer compounds. Thermodynamics of the Nb-Al system were reviewed and activities of Nb and Al were derived at desired calculation temperatures. Criteria for chemical compatibility between the reinforcement material and Nb-Al compounds have been defined and several chemically compatible reinforcement materials have been identified.

  9. Thermodynamic analysis of chemical compatibility of several reinforcement materials with niobium aluminides

    Science.gov (United States)

    Misra, Ajay K.

    1989-01-01

    Chemical compatibility of several reinforcement materials with three niobium aluminides, Nb3Al, Nb2Al, and NbAl3, were examined from thermodynamic considerations. The reinforcement materials considered in this study include carbides, borides, nitrides, oxides, silicides, and Engel-Brewer compounds. Thermodynamics of the Nb-Al system were reviewed and activities of Nb and Al were derived at desired calculation temperatures. Criteria for chemical compatibility between the reinforcement material and Nb-Al compounds have been defined and several chemically compatible reinforcement materials have been identified.

  10. Burden of disease and costs of exposure to endocrine disrupting chemicals in the European Union: an updated analysis

    DEFF Research Database (Denmark)

    Trasande, L.; Zoeller, R. T.; Hass, Ulla;

    2016-01-01

    A previous report documented that endocrine disrupting chemicals contribute substantially to certain forms of disease and disability. In the present analysis, our main objective was to update a range of health and economic costs that can be reasonably attributed to endocrine disrupting chemical...... Group, and evaluated laboratory and animal evidence of endocrine disruption using definitions recently promulgated by the Danish Environmental Protection Agency. The Delphi method was used to make decisions on the strength of the data. Expert panels consensus was achieved for probable (>20%) endocrine...... disrupting chemical causation for IQ loss and associated intellectual disability; autism; attention deficit hyperactivity disorder; endometriosis; fibroids; childhood obesity; adult obesity; adult diabetes; cryptorchidism; male infertility, and mortality associated with reduced testosterone. Accounting...

  11. Surface reactivity and layer analysis of chemisorbed reaction films in the surface-chemical environment of alkyl octadecenoates

    Indian Academy of Sciences (India)

    R B Choudhary; O N Anand; O S Tyagi

    2009-05-01

    Studies on surface reactivity of substrate iron (Fe-particles) were made in the tribo-chemical environment of alkyl octadecenoates. Two alkyl octadecenoates namely ethyl octadecenoate and methyl 12-hydroxy octadecenoate, slightly different in their chemical nature, were taken for preparing the chemisorbed reaction films (CRF) at the temperature 100 ± 5°C. The reaction products collected in the composite (amorphous) phase were isolated into three different solvent-soluble fractions (sub-layer films) using polar solvents of increasing polar strength. The FTIR analysis of these films showed that these were primarily organic in nature and were composed of alkyl and/or aryl hydroxy ethers, unsaturated hydroxy ketones, and aromatic structures chemically linked with iron surface. These reaction films also contained large amount of iron (Fe). Further, these film fractions also showed varying thermal behaviour during thermal decomposition in the temperature range of 50-800°C when thermally evaluated in the nitrogen environment.

  12. Analysis of chemical warfare agents in organic liquid samples with magnetic dispersive solid phase extraction and gas chromatography mass spectrometry for verification of the chemical weapons convention.

    Science.gov (United States)

    Singh, Varoon; Purohit, Ajay Kumar; Chinthakindi, Sridhar; Goud, Raghavender D; Tak, Vijay; Pardasani, Deepak; Shrivastava, Anchal Roy; Dubey, Devendra Kumar

    2016-05-27

    A simple, sensitive and low temperature sample preparation method is developed for detection and identification of Chemical Warfare Agents (CWAs) and scheduled esters in organic liquid using magnetic dispersive solid phase extraction (MDSPE) followed by gas chromatography-mass spectrometry analysis. The method utilizes Iron oxide@Poly(methacrylic acid-co-ethylene glycol dimethacrylate) resin (Fe2O3@Poly(MAA-co-EGDMA)) as sorbent. Variants of these sorbents were prepared by precipitation polymerization of methacrylic acid-co-ethylene glycol dimethacrylate (MAA-co-EGDMA) onto Fe2O3 nanoparticles. Fe2O3@poly(MAA-co-EGDMA) with 20% MAA showed highest recovery of analytes. Extractions were performed with magnetic microspheres by MDSPE. Parameters affecting the extraction efficiency were studied and optimized. Under the optimized conditions, method showed linearity in the range of 0.1-3.0μgmL(-1) (r(2)=0.9966-0.9987). The repeatability and reproducibility (relative standard deviations (RSDs) %) were in the range of 4.5-7.6% and 3.4-6.2% respectively for organophosphorous esters in dodecane. Limits of detection (S/N=3/1) and limit of quantification (S/N=10/1) were found to be in the range of 0.05-0.1μgmL(-1) and 0.1-0.12μgmL(-1) respectively in SIM mode for selected analytes. The method was successfully validated and applied to the extraction and identification of targeted analytes from three different organic liquids i.e. n-hexane, dodecane and silicon oil. Recoveries ranged from 58.7 to 97.3% and 53.8 to 95.5% at 3μgmL(-1) and 1μgmL(-1) spiking concentrations. Detection of diethyl methylphosphonate (DEMP) and O-Ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX) in samples provided by the Organization for Prohibition of Chemical Weapons Proficiency Test (OPCW-PT) proved the utility of the developed method for the off-site analysis of CWC relevant chemicals. PMID:27113675

  13. Analysis of weblike network structures of directed graphs for chemical reactions in methane plasmas

    International Nuclear Information System (INIS)

    Chemical reactions of molecular gases like methane are so complicated that a chart of decomposed and/or synthesized species originating from molecules in plasma resembles a weblike network in which we write down species and reactions among them. Here we consider properties of the network structures of chemical reactions in methane plasmas. In the network, atoms/molecules/radical species are assumed to form nodes and chemical reactions correspond to directed edges in the terminology of graph theory. Investigation of the centrality index reveals importance of CH3 in the global chemical reaction, and difference of an index for each radical species between cases with and without electrons clarifies that the electrons are at an influential position to tighten the network structure

  14. Chemical analysis of Mycenaean pottery from the Menelaion and its vicinity

    OpenAIRE

    Jones, R E; Tomlinson, J.T.

    2009-01-01

    A chemical characterisation of the Mycenaean pottery from the major prehistoric site of the Menelaion in Laconia. The study defines the the lcoal pottery production and identifies the imports from various centres.

  15. Measurement and analysis of chemically changed mineral fibers after experiments in vitro and in vivo.

    OpenAIRE

    Spurny, K.R.

    1983-01-01

    Asbestos, as well as other natural and man-made mineral fibers used for in vitro and in vivo experiments, must be described and defined physically and chemically as exactly as possible before any application. The interactions of fibers with the physical, chemical (air, water, etc.) and biological (cells, tissues, etc.) environments cause important changes in fiber chemistry and crystalline structure. Also, these should be detected as precisely as possible after each experiment. Our recent inv...

  16. Analysis Of Names Of Organic Chemical Compounds By Using Parser Combinators And The Generative Lexicon Theory

    OpenAIRE

    Márcio de Souza Dias; Rita Maria Silva Julia; Eduardo Costa Pereira

    2011-01-01

    This work proposes OCLAS (Organic Chemistry Language Ambiguity Solver), an automatic system to analyze syntactically and semantically Organic Chemistry compound names and to generate the pictures of their chemical structures. If both parses detect that the input name corresponds to a theoretically possible organic chemical compound, the system generates its molecular structure picture, whether or not the name respects the current official nomenclature. This capacity of treating ev...

  17. Physico Chemical Analysis of Municipal Wastewater Discharge in Ganga River,Haridwar District of Uttarakhand, India

    OpenAIRE

    Saba Shirin; Akhilesh Kumar Yadav

    2014-01-01

    This study was aimed to screen the water quality of Ganga River in Haridwar city, Uttarakhand, India. The study was conducted based on their water source, origin of pollution such as utilisation by human and animals. Monthly changes in physico-chemical parameters such as pH, Temperature, Total Dissolved Solids, Total Solids, Total Suspended Solids, Chemical Oxygen Demand, Dissolved oxygen, Biochemical Oxygen Demand and Volatile Suspended Solids were analyzed for a period of twoyear fromJanuar...

  18. Multivariate analysis of chemical properties in oxisols with different levels of intervention agricultural

    OpenAIRE

    Camacho-Tamayo, Jesús H.; Luengas-Gómez, Carlos; Fabio R Leiva

    2010-01-01

    Human intervention in agricultural production affects directly soil quality by promoting changes in physical and chemical properties through the use of fertilizers, correctives and tillage practices (Brachiria and corn- soybean). The aim of this study was to evaluate changes in the chemical properties of two Oxisols (Typic Hapludox y Typic Haplustox) with different intervention levels, in the municipality of Puerto Lopez (Meta-Colombia). Samples were taken at 42 points, spaced 25 m perpendicu...

  19. Analysis of primary coolant pump seal water distribution influence to chemical and volume system design

    International Nuclear Information System (INIS)

    The possible influences to Chemical and Volume Control System design caused by coolant pump seal water distribution are discussed. The essential reason is picked out in this paper. The temperature drop of charging flow at the regenerative heat exchanger outlet is calculated, and the feasible retrofits of the Chemical and Volume Control System are illustrated. The thermal hydraulic software Flowmaster 7.5 is employed to numerically investigate the possible capability of charging pump with different coolant pump seal requirements. (authors)

  20. Analysis of the comprehensibility of chemical hazard communication tools at the industrial workplace.

    Science.gov (United States)

    Ta, Goh Choo; Mokhtar, Mazlin Bin; Mohd Mokhtar, Hj Anuar Bin; Ismail, Azmir Bin; Abu Yazid, Mohd Fadhil Bin Hj

    2010-01-01

    Chemical classification and labelling systems may be roughly similar from one country to another but there are significant differences too. In order to harmonize various chemical classification systems and ultimately provide consistent chemical hazard communication tools worldwide, the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) was endorsed by the United Nations Economic and Social Council (ECOSOC). Several countries, including Japan, Taiwan, Korea and Malaysia, are now in the process of implementing GHS. It is essential to ascertain the comprehensibility of chemical hazard communication tools that are described in the GHS documents, namely the chemical labels and Safety Data Sheets (SDS). Comprehensibility Testing (CT) was carried out with a mixed group of industrial workers in Malaysia (n=150) and factors that influence the comprehensibility were analysed using one-way ANOVA. The ability of the respondents to retrieve information from the SDS was also tested in this study. The findings show that almost all the GHS pictograms meet the ISO comprehension criteria and it is concluded that the underlying core elements that enhance comprehension of GHS pictograms and which are also essential in developing competent persons in the use of SDS are training and education. PMID:20616463

  1. Chemical Analysis of Whale Breath Volatiles: A Case Study for Non-Invasive Field Health Diagnostics of Marine Mammals

    Directory of Open Access Journals (Sweden)

    Raquel Cumeras

    2014-09-01

    Full Text Available We explored the feasibility of collecting exhaled breath from a moribund gray whale (Eschrichtius robustus for potential non-invasive health monitoring of marine mammals. Biogenic volatile organic compound (VOC profiling is a relatively new field of research, in which the chemical composition of breath is used to non-invasively assess the health and physiological processes on-going within an animal or human. In this study, two telescopic sampling poles were designed and tested with the primary aim of collecting whale breath exhalations (WBEs. Once the WBEs were successfully collected, they were immediately transferred onto a stable matrix sorbent through a custom manifold system. A total of two large volume WBEs were successfully captured and pre-concentrated onto two Tenax®-TA traps (one exhalation per trap. The samples were then returned to the laboratory where they were analyzed using solid phase micro extraction (SPME and gas chromatography/mass spectrometry (GC/MS. A total of 70 chemicals were identified (58 positively identified in the whale breath samples. These chemicals were also matched against a database of VOCs found in humans, and 44% of chemicals found in the whale breath are also released by healthy humans. The exhaled gray whale breath showed a rich diversity of chemicals, indicating the analysis of whale breath exhalations is a promising new field of research.

  2. Biological Sampling and Analysis in Sinclair and Dyes Inlets, Washington: Chemical Analyses for 2007 Puget Sound Biota Study

    Energy Technology Data Exchange (ETDEWEB)

    Brandenberger, Jill M.; Suslick, Carolynn R.; Johnston, Robert K.

    2008-10-09

    Evaluating spatial and temporal trends in contaminant residues in Puget Sound fish and macroinvertebrates are the objectives of the Puget Sound Ambient Monitoring Program (PSAMP). In a cooperative effort between the ENVironmental inVESTment group (ENVVEST) and Washington State Department of Fish and Wildlife, additional biota samples were collected during the 2007 PSAMP biota survey and analyzed for chemical residues and stable isotopes of carbon (δ13C) and nitrogen (δ15N). Approximately three specimens of each species collected from Sinclair Inlet, Georgia Basin, and reference locations in Puget Sound were selected for whole body chemical analysis. The muscle tissue of specimens selected for chemical analyses were also analyzed for δ13C and δ15N to provide information on relative trophic level and food sources. This data report summarizes the chemical residues for the 2007 PSAMP fish and macro-invertebrate samples. In addition, six Spiny Dogfish (Squalus acanthias) samples were necropsied to evaluate chemical residue of various parts of the fish (digestive tract, liver, embryo, muscle tissue), as well as, a weight proportional whole body composite (WBWC). Whole organisms were homogenized and analyzed for silver, arsenic, cadmium, chromium, copper, nickel, lead, zinc, mercury, 19 polychlorinated biphenyl (PCB) congeners, PCB homologues, percent moisture, percent lipids, δ13C, and δ15N.

  3. LSENS, a general chemical kinetics and sensitivity analysis code for homogeneous gas-phase reactions. 2: Code description and usage

    Science.gov (United States)

    Radhakrishnan, Krishnan; Bittker, David A.

    1994-01-01

    LSENS, the Lewis General Chemical Kinetics Analysis Code, has been developed for solving complex, homogeneous, gas-phase chemical kinetics problems and contains sensitivity analysis for a variety of problems, including nonisothermal situations. This report is part 2 of a series of three reference publications that describe LSENS, provide a detailed guide to its usage, and present many example problems. Part 2 describes the code, how to modify it, and its usage, including preparation of the problem data file required to execute LSENS. Code usage is illustrated by several example problems, which further explain preparation of the problem data file and show how to obtain desired accuracy in the computed results. LSENS is a flexible, convenient, accurate, and efficient solver for chemical reaction problems such as static system; steady, one-dimensional, inviscid flow; reaction behind incident shock wave, including boundary layer correction; and perfectly stirred (highly backmixed) reactor. In addition, the chemical equilibrium state can be computed for the following assigned states: temperature and pressure, enthalpy and pressure, temperature and volume, and internal energy and volume. For static problems the code computes the sensitivity coefficients of the dependent variables and their temporal derivatives with respect to the initial values of the dependent variables and/or the three rate coefficient parameters of the chemical reactions. Part 1 (NASA RP-1328) derives the governing equations describes the numerical solution procedures for the types of problems that can be solved by lSENS. Part 3 (NASA RP-1330) explains the kinetics and kinetics-plus-sensitivity-analysis problems supplied with LSENS and presents sample results.

  4. Analysis of a Stochastic Chemical System Close to a SNIPER Bifurcation of Its Mean-Field Model

    KAUST Repository

    Erban, Radek

    2009-01-01

    A framework for the analysis of stochastic models of chemical systems for which the deterministic mean-field description is undergoing a saddle-node infinite period (SNIPER) bifurcation is presented. Such a bifurcation occurs, for example, in the modeling of cell-cycle regulation. It is shown that the stochastic system possesses oscillatory solutions even for parameter values for which the mean-field model does not oscillate. The dependence of the mean period of these oscillations on the parameters of the model (kinetic rate constants) and the size of the system (number of molecules present) are studied. Our approach is based on the chemical Fokker-Planck equation. To gain some insight into the advantages and disadvantages of the method, a simple one-dimensional chemical switch is first analyzed, and then the chemical SNIPER problem is studied in detail. First, results obtained by solving the Fokker-Planck equation numerically are presented. Then an asymptotic analysis of the Fokker-Planck equation is used to derive explicit formulae for the period of oscillation as a function of the rate constants and as a function of the system size. © 2009 Society for Industrial and Applied Mathematics.

  5. Chemical speciation analysis and environmental behaviour of 127I and 129I

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Violeta

    2011-10-15

    Chemical speciation analysis of 129I and 127I as iodide, iodate and total inorganic iodine in seawater samples from the Baltic Proper, Skagerrak and Kattegat has been carried out. The important findings of this study are that the reduction of iodate and oxidation of iodide in Skagerrak and Kattegat may be a slow process while along the Baltic Sea surface water reduction of iodate is a relatively fast process. Although suboxic or anoxic condition are encountered in some of the Baltic Sea deep basins, the concentration of 129IO{sub 3}- increases with water depth indicating that the reduction of iodate in the oxygen deficient bottom water of the Baltic Sea is a slow process. Iodine chemical speciation analysis (as iodide, iodate and total iodine including inorganic and organic iodine species) in lake water samples collected from Denmark and southern Sweden has been carried out. Destruction of organic iodine was performed by alkaline oxidation using NaOH - NaClO at 100 deg. C and anion exchange chromatography was used for separation of iodide and iodate. Iodine-129 concentrations in the lakes ranged from 1.3 - 12.8 x109 at/L and show elevated concentrations in lakes located in southwest Jutland (Denmark), near the North Sea. Except the Skaersoe Lake, were the organic iodine - 127 accounts for 50% of the total iodine, iodide (both 129I and 127I) is the predominant species form in surface water of the studied lakes. An investigation was conducted in order to quantify the total aquatic iodine (129I and 127I as inorganic and organic iodine) from fresh water and seawater samples by adsorption onto activated charcoal and DEAE 32 cellulose followed by alkaline digestion or combustion. The results show that iodide from freshwater samples can easily be adsorbed onto activated charcoal. The sorption was not affected by the pH. The absorption capacity of iodate is low and reduces quickly when its concentration increases. Compared with activated charcoal, DEAE 32 cellulose showed

  6. Thermogravimetric analysis of petroleum asphaltenes along with estimation of average chemical structure by nuclear magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Combining with the 1H and 13C nuclear magnetic resonance (NMR) determinations, elemental analysis and molecular weight measurement, average molecular formula of the chemical unit for the asphaltenes from Chinese Daqing crude oil were calculated. Thermal pyrolysis kinetics of the asphaltenes had been studied using thermogravimetric analysis (TGA). The distributed activation energy model (DAEM) was used to analyze these complex systems. The results show that the peak activation energy for pyrolysis of the asphaltenes is 245 kJ mol-1 and the pre-exponential factor is 5.88 x 1014 s-1. The DAEM method presented reasonably good results of the prediction of the weight loss curves. A linear relationship can be found from the plots of logarithm of the pre-exponential factor against the activation energy at selected conversion values. This phenomenon known as the compensation effect was explained and it was in agreement with the estimated chemical structure determined by NMR

  7. Synthesis, spectral analysis, structural elucidation and quantum chemical studies of (E)-methyl-4-[(2-phenylhydrazono)methyl]benzoate

    Science.gov (United States)

    Şahin, Zarife Sibel; Şenöz, Hülya; Tezcan, Habibe; Büyükgüngör, Orhan

    2015-05-01

    The title compound, (E)-methyl-4-[(2-phenylhydrazono)methyl]benzoate, (I), (C15H14N2O2), has been synthesized by condensation reaction of methyl-4-formylbenzoate and phenylhydrazine. The compound has been characterized by elemental analysis, IR, 1H NMR, 13C NMR, UV-Vis spectroscopies and single crystal X-ray diffraction techniques. Optimized molecular structure, harmonic vibrational frequencies, 1H and 13C NMR chemical shifts have been investigated by B3LYP/6-31G(d,p) method using density functional theory (DFT). Global chemical reactivity descriptors, natural population analysis (NPA), thermodynamic and non-linear optical (NLO) properties have also been studied. The energetic behavior of the compound has been examined in solvent media using the integral equation formalism polarizable continuum model (IEF-PCM).

  8. Standard test methods for chemical and mass spectrometric analysis of nuclear-grade gadolinium oxide (Gd2O3) powder

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 These test methods cover procedures for the chemical and mass spectrometric analysis of nuclear-grade gadolinium oxide powders to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Carbon by Direct CombustionThermal Conductivity C1408 Test Method for Carbon (Total) in Uranium Oxide Powders and Pellets By Direct Combustion-Infrared Detection Method Total Chlorine and Fluorine by Pyrohydrolysis Ion Selective Electrode C1502 Test Method for Determination of Total Chlorine and Fluorine in Uranium Dioxide and Gadolinium Oxide Loss of Weight on Ignition 7-13 Sulfur by CombustionIodometric Titration Impurity Elements by a Spark-Source Mass Spectrographic C761 Test Methods for Chemical, Mass Spectrometric, Spectrochemical,Nuclear, and Radiochemical Analysis of Uranium Hexafluoride C1287 Test Method for Determination of Impurities In Uranium Dioxide By Inductively Coupled Plasma Mass Spectrometry Gadolinium Content in Gadolinium Oxid...

  9. Analysis of essential oils from Voacanga africana seeds at different hydrodistillation extraction stages: chemical composition, antioxidant activity and antimicrobial activity.

    Science.gov (United States)

    Liu, Xiong; Yang, Dongliang; Liu, Jiajia; Ren, Na

    2015-01-01

    In this study, essential oils from Voacanga africana seeds at different extraction stages were investigated. In the chemical composition analysis, 27 compounds representing 86.69-95.03% of the total essential oils were identified and quantified. The main constituents in essential oils were terpenoids, alcohols and fatty acids accounting for 15.03-24.36%, 21.57-34.43% and 33.06-57.37%, respectively. Moreover, the analysis also revealed that essential oils from different extraction stages possessed different chemical compositions. In the antioxidant evaluation, all analysed oils showed similar antioxidant behaviours, and the concentrations of essential oils providing 50% inhibition of DPPH-scavenging activity (IC50) were about 25 mg/mL. In the antimicrobial experiments, essential oils from different extraction stages exhibited different antimicrobial activities. The antimicrobial activity of oils was affected by extraction stages. By controlling extraction stages, it is promising to obtain essential oils with desired antimicrobial activities. PMID:25686854

  10. Chemical or Biological Terrorist Attacks: An Analysis of the Preparedness of Hospitals for Managing Victims Affected by Chemical or Biological Weapons of Mass Destruction

    Directory of Open Access Journals (Sweden)

    Russell L. Bennett

    2006-03-01

    and analysis. Six hypotheses were tested. Using a questionnaire survey, the availability of functional preparedness plans, specific preparedness education/training, decontamination facilities, surge capacity, pharmaceutical supplies, and laboratory diagnostic capabilities of hospitals were examined. The findings revealed that a majority (89.2% of hospitals in the State of Mississippi have documented preparedness plans, provided specific preparedness education/training (89.2%, have dedicated facilities for decontamination (75.7%, and pharmaceutical plans and supplies (56.8% for the treatment of victims in the event of a disaster involving chemical or biological WMD. However, over half (59.5% of the hospitals could not increase surge capacity (supplies, equipment, staff, patient beds, etc. and lack appropriate laboratory diagnostic services (91.9% capable of analyzing and identifying WMD. In general, hospitals in the State of Mississippi, like a number of hospitals throughout the United States, are still not adequately prepared to manage victims of terrorist attacks involving chemical or biological WMD which consequently may result in the loss of hundreds or even thousands of lives. Therefore, hospitals continue to require substantial resources at the local, State, and national levels in order to be “truly” prepared.

  11. Chemical analysis of turmeric from Minas Gerais, Brazil and comparison of methods for flavour free oleoresin

    Directory of Open Access Journals (Sweden)

    Cyleni R. A. Souza

    1998-01-01

    Full Text Available Chemical analysis of turmeric (Curcuma longa L cultivated in eight different cities in the state of Minas Gerais, Brazil was carried out. The levels of curcuminoid pigments varied from 1.4 to 6.14 g/100 g and of volatile oil from 0.97 to 7.55 mL/100 g (dry basis. Samples from Patrocínio, Arinos and Brasilândia contained higher pigment levels compared to the others. The sample from Patrocínio contained the highest volatile oil content. The mean levels of ethyl ether extract, protein, fiber, ash and starch were 8.51, 7.01, 7.22, 7.81 and 39.87 g/100 g dry basis, respectively. Laboratory extraction of flavour free oleoresin was performed in triplicate. A higher yield of pigment in the oleoresin was obtained when the volatile oil was extracted with water vapor and the oleoresin with ethanol. The oleoresin obtained was free of flavour and could be used in a wider range of food applications.Análise química de cúrcuma (Curcuma longa L provenientes de oito municípios do Estado de Minas Gerais - Brasil foi efetuada. Os teores (base seca de pigmentos curcuminóides variaram de 1,4 a 6,14 g/100 g e os de óleo volátil, de 0,97 a 7,55 mL/100 g. Amostras de Patrocínio, Arinos e Brasilândia continham os maiores teores de pigmentos e as de Patrocínio os maiores teores de óleos voláteis. Os teores médios (base seca de extrato etéreo, proteínas, fibras, cinzas e amido encontrados foram 8,51; 7,01; 7,22; 7,81 e 39,87 g/100 g, respectivamente. Com o objetivo de obter corante amarelo isento de flavor, métodos de extração em laboratório foram comparados em triplicata. Um maior rendimento de pigmento na oleoresina foi obtido extraindo-se o óleo volátil com vapor d'água e a oleoresina com etanol. A oleoresina obtida é isenta de flavor e pode ser utilizada em um número maior de aplicações na indústria alimentícia

  12. Determination of sulphide concentrates of ore copper by XRPD and chemical analysis

    Directory of Open Access Journals (Sweden)

    Cocić Mira B.

    2009-01-01

    Full Text Available Roasting process of sulphide copper concentrates in fluo-solid reactor is an oxidation process, and presents the first stage of copper concentrate processing in Copper Mining and Smelting Complex Bor, RTB Bor. Therefore, the importance of accurate and up to date process control is an apparent precondition for the correct treatment in the following stages and also for of high grade cathode copper. As concentrate is fed into the roaster, it is heated by a stream of hot air to about 590°C. The process takes place between solid and gaseous phases without the appearance of a liquid phase. The heat generated by the exothermic oxidation reaction of sulphur from cooper and iron minerals (chalcopyrite and pyrite is sufficient to carry out the entire process autogenously at temperature from 620 to 670°C. The temperature of sulphur firing which defines the start of roasting depends on physical traits, particle size of sulfides and characteristic product of oxidation. The obtained products of the roasting process are: calcine, ready for smelting in the furnace and gas-rich sulphure dioxide (SO2, well suited for the production of sulfuric acid. The relationship between the quantitative mineral composition of the charge and of the calcine directly points out to the efficiency of the roasting process in fluo-solid reactor. The amount of bornite and magnetite, resulting from the sulfide oxidation is the most important parameter. Hence, quantitative determination of mineral composition is of great interest. In this work, the results of the determination of quantitative mineral composition of the copper sulphide concentrate (charge and products of their roasting (calcine and overflow in fluo-solid reactor in the RTB Bor are presented. The aim was to compare the results of the iron, copper, sulfur and oxygen contents determined by two independent techniques, the chemical (HA and X-ray powder diffraction analysis (XRPD that is based on the quantitative mineral

  13. Chemical Composition by Neutron Activation Analysis (INAA) of Neo-Assyrian Palace Ware from Iraq, Syria and Israel

    OpenAIRE

    Hunt, Alice M W; Johannes H Sterba

    2013-01-01

    Neo-Assyrian Palace Ware is an 8th-7th century B.C.E. fine-ware which originated in Northern Mesopotamia and spread throughout the greater Levant. The mechanism by which Palace Ware moved across the Neo-Assyrian imperial landscape (trade or local imitation/emulation) is of great archaeological interest. This dataset provides chemical compositional data, generated using instrumental neutron activation analysis (INAA), for Palace Ware vessels from Nimrud and Nineveh, in the Assyrian imperial co...

  14. Validation and assessment of uncertainty of chemical tests as a tool for the reliability analysis of wastewater IPEN

    International Nuclear Information System (INIS)

    The validation of analytical methods has become an indispensable tool for the analysis in chemical laboratories, including being required for such accreditation. However, even if a laboratory using validated methods of analysis there is the possibility that these methods generate results discrepant with reality by making necessary the addition of a quantitative attribute (a value) which indicates the degree of certainty the extent or the analytical method used. This measure assigned to the result of measurement is called measurement uncertainty. We estimate this uncertainty with a level of confidence both direction, an analytical result has limited significance if not carried out proper assessment of its uncertainty. One of the activities of this work was to elaborate a program to help the validation and evaluation of uncertainty in chemical analysis. The program was developed with Visual Basic programming language and method of evaluation of uncertainty introduced the following concepts based on the GUM (Guide to the Expression of Uncertainty in Measurement). This evaluation program uncertainty measurement will be applied to chemical analysis in support of the characterization of the Nuclear Fuel Cycle developed by IPEN and the study of organic substances in wastewater associated with professional activities of the Institute. In the first case, primarily for the determination of total uranium and the second case for substances that were generated by human activities and that are contained in resolution 357/2005. As strategy for development of this work was considered the PDCA cycle to improve the efficiency of each step and minimize errors while performing the experimental part. The program should be validated to meet requirements of standards such as, for example, the standard ISO/IEC 17025. The application, it is projected to use in other analytical procedures of both the Nuclear Fuel Cycle and in the control program and chemical waste management of IPEN

  15. INVESTIGATION OF THE CHEMICAL STRUCTURE OF CARBOXYLATED AND CARBOXYMETHYLATED FIBERS FROM WASTE PAPER VIA XRD AND FTIR ANALYSIS

    OpenAIRE

    Mohammad Mohkami Mail; Mohammad Talaeipour

    2011-01-01

    This paper describes preparation of carboxymethylated and carboxylated cellulosic fibers from waste paper. Chemical properties of the product were distinguished by Fourier-transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) spectral analysis. To produce carboxylated and crosslinked fibers and also to increase the anionic surface charge of the fibers, maleic anhydride was used in three different batches; 0, 1%, and 5%. The treatment condition for producing carboxymethylated fibe...

  16. De Novo Assembly and Transcriptome Analysis of Wheat with Male Sterility Induced by the Chemical Hybridizing Agent SQ-1

    OpenAIRE

    Qidi Zhu; Yulong Song; Gaisheng Zhang; Lan Ju; Jiao Zhang; Yongang Yu; Na Niu; Junwei Wang; Shoucai Ma

    2015-01-01

    Wheat (Triticum aestivum L.), one of the world's most important food crops, is a strictly autogamous (self-pollinating) species with exclusively perfect flowers. Male sterility induced by chemical hybridizing agents has increasingly attracted attention as a tool for hybrid seed production in wheat; however, the molecular mechanisms of male sterility induced by the agent SQ-1 remain poorly understood due to limited whole transcriptome data. Therefore, a comparative analysis of wheat anther tra...

  17. Toxicogenomic Analysis Suggests Chemical-Induced Sexual Dimorphism in the Expression of Metabolic Genes in Zebrafish Liver

    OpenAIRE

    Xun Zhang; Choong Yong Ung; Siew Hong Lam; Jing Ma; Yu Zong Chen; Louxin Zhang; Zhiyuan Gong; Baowen Li

    2012-01-01

    Differential gene expression in two sexes is widespread throughout the animal kingdom, giving rise to sex-dimorphic gene activities and sex-dependent adaptability to environmental cues, diets, growth and development as well as susceptibility to diseases. Here, we present a study using a toxicogenomic approach to investigate metabolic genes that show sex-dimorphic expression in the zebrafish liver triggered by several chemicals. Our analysis revealed that, besides the known genes for xenobioti...

  18. 我国煤化工发展分析%China Coal Chemical Industry Development Analysis

    Institute of Scientific and Technical Information of China (English)

    李志龙; 陈明

    2011-01-01

    The paper stated the characteristics of the coal chemical and analyzed the challenges and opportunities of the coal chemical development in China.The coal chemical must stick to the principle of being in proportion and in order.We need pay close attenton to international markets of crude oil and chemical products and analyse carefully the market competitiveness of coal-base products.Actively promote coal production enterprises and chemical enterprise power-and-power union.%文章阐述了新型煤化工的特点,分析了中国发展煤化工面临的挑战和机遇。发展煤化工必须坚持适度、有序的原则,综合考虑社会投入,高度关注国际油价和石化产品市场,认真分析市场竞争力,积极推动煤炭生产企业与煤化工企业强强联合。

  19. Performance analysis of solar-assisted chemical heat-pump dryer

    Energy Technology Data Exchange (ETDEWEB)

    Fadhel, M.I. [Solar Energy Research Institute, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Faculty of Engineering and Technology, Multimedia University, Jalan Ayer Keroh Lama, 75450, Melaka (Malaysia); Sopian, K.; Daud, W.R.W. [Solar Energy Research Institute, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2010-11-15

    A solar-assisted chemical heat-pump dryer has been designed, fabricated and tested. The performance of the system has been studied under the meteorological conditions of Malaysia. The system consists of four main components: solar collector (evacuated tubes type), storage tank, solid-gas chemical heat pump unit and dryer chamber. A solid-gas chemical heat pump unit consists of reactor, condenser and evaporator. The reaction used in this study (CaCl2-NH{sub 3}). A simulation has been developed, and the predicted results are compared with those obtained from experiments. The maximum efficiency for evacuated tubes solar collector of 80% has been predicted against the maximum experiment of 74%. The maximum values of solar fraction from the simulation and experiment are 0.795 and 0.713, respectively, whereas the coefficient of performance of chemical heat pump (COP{sup h}) maximum values 2.2 and 2 are obtained from simulation and experiments, respectively. The results show that any reduction of energy at condenser as a result of the decrease in solar radiation will decrease the coefficient of performance of chemical heat pump as well as decrease the efficiency of drying. (author)

  20. New methods for toxicokinetic studies on chemicals carcinogens by means of analysis of DNA damage

    International Nuclear Information System (INIS)

    For investigating the potential carcinogenic properties of chemicals or for elucidating their mechanisms of activities, it is as important to determine their DNA damaging effects as it is to determine their mutagenicity. In the following, three methods will be presented which may be utilized to detect chemically induced DNA damage. These are the classical DNA filter elution procedure (AE), the in situ nick translation (NT), and the single cell microgel-electrophoresis (MGE) assay. Latter two methods have the advantage that they will allow genotoxic effects to be determined in many organs of the experimental animals, since only minute quantities of tissue are needed. Therefore it is possible to efficiently obtain data pertaining to the toxicokinetics of the test chemical which may be used for purposes of risk assessment. (orig.)

  1. Potential of Palm Olein as Green Lubricant Source: Lubrication Analysis and Chemical Characterisation

    International Nuclear Information System (INIS)

    Palm olein (POo) is widely used as edible oil in tropical countries. The lubrication properties and chemical compositions of POo being considered to be used as renewable raw material for bio lubricant synthesis. POo is suitable to be used directly as bio lubricant for medium temperature industrial applications. Palm olein has good viscosity index, oxidative stability, flash and fire point as a lubricant source. POo contains unsaturated triacylglycerols (TAG): Palmitin-Olein-Olein, POO (33.3 %), Palmitin-Olein-Palmitin, POP (29.6 %), which are very important to produce good lubricant properties. This unsaturated bond is preferable in chemical modification to produce bio lubricant. The chemical compositions of POo were tested by using high performance liquid chromatography (HPLC) and gas chromatography (GC) techniques. (author)

  2. XLPM: efficient algorithm for the analysis of protein-protein contacts using chemical cross-linking mass spectrometry

    OpenAIRE

    Jaiswal, Mihir; Crabtree, Nathaniel Mark; Bauer, Michael A; Hall, Roger; Raney, Kevin D.; Boris L Zybailov

    2014-01-01

    Background Chemical cross-linking is used for protein-protein contacts mapping and for structural analysis. One of the difficulties in cross-linking studies is the analysis of mass-spectrometry data and the assignment of the site of cross-link incorporation. The difficulties are due to higher charges of fragment ions, and to the overall low-abundance of cross-link species in the background of linear peptides. Cross-linkers non-specific at one end, such as photo-inducible diazirines, may compl...

  3. Burden of disease and costs of exposure to endocrine disrupting chemicals in the European Union: an updated analysis.

    Science.gov (United States)

    Trasande, L; Zoeller, R T; Hass, U; Kortenkamp, A; Grandjean, P; Myers, J P; DiGangi, J; Hunt, P M; Rudel, R; Sathyanarayana, S; Bellanger, M; Hauser, R; Legler, J; Skakkebaek, N E; Heindel, J J

    2016-07-01

    A previous report documented that endocrine disrupting chemicals contribute substantially to certain forms of disease and disability. In the present analysis, our main objective was to update a range of health and economic costs that can be reasonably attributed to endocrine disrupting chemical exposures in the European Union, leveraging new burden and disease cost estimates of female reproductive conditions from accompanying report. Expert panels evaluated the epidemiologic evidence, using adapted criteria from the WHO Grading of Recommendations Assessment, Development and Evaluation Working Group, and evaluated laboratory and animal evidence of endocrine disruption using definitions recently promulgated by the Danish Environmental Protection Agency. The Delphi method was used to make decisions on the strength of the data. Expert panels consensus was achieved for probable (>20%) endocrine disrupting chemical causation for IQ loss and associated intellectual disability; autism; attention deficit hyperactivity disorder; endometriosis; fibroids; childhood obesity; adult obesity; adult diabetes; cryptorchidism; male infertility, and mortality associated with reduced testosterone. Accounting for probability of causation, and using the midpoint of each range for probability of causation, Monte Carlo simulations produced a median annual cost of €163 billion (1.28% of EU Gross Domestic Product) across 1000 simulations. We conclude that endocrine disrupting chemical exposures in the EU are likely to contribute substantially to disease and dysfunction across the life course with costs in the hundreds of billions of Euros per year. These estimates represent only those endocrine disrupting chemicals with the highest probability of causation; a broader analysis would have produced greater estimates of burden of disease and costs. PMID:27003928

  4. Numerical analysis of supersonic gas jets into liquid pools with or without chemical reaction using the SERAPHIM program

    International Nuclear Information System (INIS)

    Highlights: ► We perform numerical analysis on gas jet into liquid with or without reaction. ► We apply multi-fluid model and surface reaction model. ► Proposed model can reproduce behaviors of gas jet into liquid with reaction. - Abstract: A computer program called SERAPHIM has been developed to calculate multicomponent multiphase flow involving sodium-water chemical reaction in a steam generator of sodium cooled fast reactors. In this study, numerical analyses of supersonic gas jets into liquid pools with or without chemical reaction were performed to validate proposed numerical methods. The SERAPHIM program uses a multi-fluid model and a HSMAC method modified for compressible multiphase flows. An interfacial drag force was calculated from a newly constructed model. A surface reaction model, which has been developed by the authors, was applied to evaluate a mass generation rate by chemical reaction between a gas and liquid phase. As validation for a non-reaction problem, the experiment on horizontal supersonic air jet into water was analyzed. Numerical results showed that velocity of the injected air decreased by the effect of a interfacial drag force, and then the air went upward because of buoyancy. A horizontal penetration length of the air jet agreed with experimental results very well. On the other hand, we analyzed the experiment on vertical supersonic chlorine jet into Na–NaCl mixture. In this analysis, the injected gas disappeared at a certain height from chemical reaction. An estimated plume length showed good agreement with experimental data. The proposed numerical methods were found to be applicable to multiphase flow with supersonic gas jet and chemical reaction.

  5. Ab initio analysis of magnetovolume versus chemical effects in CeRuSi and its hydride

    Science.gov (United States)

    Matar, Samir F.

    2007-03-01

    The change from heavy fermion to antiferromagnetic behavior of intermetallic system CeRuSi upon hydrogenation is addressed on bases of lattice expansion and chemical bonding effects within the density-functional theoretical framework using all electron scalar-relativistic augmented spherical wave method. While no magnetic moment develops in the 111 system, from total-energy differences, the hydride is found to be stable as an antiferromagnet in the ground state, in agreement with experiment. The role of anisotropic lattice expansion induced by hydrogen insertion is shown to be prevailing over the chemical bonding between hydrogen and the metallic species especially cerium.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Analysis of chemical factors affecting marine ecosystem around nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Kwan Sik; Choi, Yoon Dong; Chun, Ki Jeong; Kim, Jin Kyu; Jung, Kyeong Chai; Lee, Yeong Keun; Park, Hyo Kook [Korea Atomic Energy Res. Inst., Taejon (Korea, Republic of)

    1994-06-01

    The ecological data of the coastal area of Youngkwang nuclear power plant from 1987 to 1993 were comprehensively analyzed, and various physical and chemical properties of sea water and sediments were measured. Major factors affecting phytoplankton standing crops were suspended substances, nitrate, and silicate. The contents of iron, chromium, copper, and sulfur in sediments sampled from the discharge channel were slightly higher than those in the other areas. In order to qantify the chemical impacts on marine ecosystem, it is desirable that a systematic survey be made through the whole year cycle to assure the consistency and confidence of the related data. (Author).

  8. Analysis of chemical factors affecting marine ecosystem around nuclear power plant

    International Nuclear Information System (INIS)

    The ecological data of the coastal area of Youngkwang nuclear power plant from 1987 to 1993 were comprehensively analyzed, and various physical and chemical properties of sea water and sediments were measured. Major factors affecting phytoplankton standing crops were suspended substances, nitrate, and silicate. The contents of iron, chromium, copper, and sulfur in sediments sampled from the discharge channel were slightly higher than those in the other areas. In order to qantify the chemical impacts on marine ecosystem, it is desirable that a systematic survey be made through the whole year cycle to assure the consistency and confidence of the related data. (Author)

  9. Characterization of Denitrifying Phosphorus Removal Microorganisms in a Novel Two-Sludge Process by Combining Chemical with Microbial Analysis

    Directory of Open Access Journals (Sweden)

    Haiming Zou

    2014-01-01

    Full Text Available The present work focuses on the investigation of denitrifying phosphorus removal organisms (DPB in a novel two-sludge denitrifying phosphorus removal process by combining chemical with microbial analysis. When the two-sludge process operated stably over one year, good phosphorus (P release and P uptake performance of activated sludge samples collected from this process were present in anaerobic and anoxic conditions, respectively, via batch test, showing that the ratio of P release specific rate to P uptake specific rate was 1.31. The analysis of energy dispersive spectrometry (EDS showed that P content of activated sludge samples collected at the end of anoxic phase was 12.3% of dry weight, further demonstrating the existence of microorganisms responsible for phosphorus removal in this two-sludge process. From polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE analysis, the presence of microorganisms mostly belonging to the phyla Firmicutes and Proteobacteria was observed, previously evidenced in the phosphorus removal wastewater treatment process. Fluorescence in situ hybridization (FISH quantitative analysis showed that Accumulibacter responsible for phosphorus removal was dominant in this two-sludge process, accounting for 69.7% of all bacteria in activated sludge. These results obtained from chemical and microbial analysis in this study suggested that denitrifying phosphorus removal microorganisms were completely enriched in the two-sludge process proposed here.

  10. Automated Chemical Analysis of Internally Mixed Aerosol Particles Using X-ray Spectromicroscopy at the Carbon K-Edge

    Energy Technology Data Exchange (ETDEWEB)

    Gilles, Mary K; Moffet, R.C.; Henn, T.; Laskin, A.

    2011-01-20

    We have developed an automated data analysis method for atmospheric particles using scanning transmission X-ray microscopy coupled with near edge X-ray fine structure spectroscopy (STXM/NEXAFS). This method is applied to complex internally mixed submicrometer particles containing organic and inorganic material. Several algorithms were developed to exploit NEXAFS spectral features in the energy range from 278 to 320 eV for quantitative mapping of the spatial distribution of elemental carbon, organic carbon, potassium, and noncarbonaceous elements in particles of mixed composition. This energy range encompasses the carbon K-edge and potassium L2 and L3 edges. STXM/NEXAFS maps of different chemical components were complemented with a subsequent analysis using elemental maps obtained by scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM/EDX). We demonstrate the application of the automated mapping algorithms for data analysis and the statistical classification of particles.

  11. Spectral analysis of colour-quenched and chemically quenched C-14 samples

    International Nuclear Information System (INIS)

    In this paper pairs of pulse height distribution curves, of C-14 samples, colour-quenched and chemically quenched was obtained. The possibility to choose a counting window in order to obtain the counting efficiency curves, for both type of quenching was studied. (Author) 7 refs

  12. Using Texas Instruments Emulators as Teaching Tools in Quantitative Chemical Analysis

    Science.gov (United States)

    Young, Vaneica Y.

    2011-01-01

    This technology report alerts upper-division undergraduate chemistry faculty and lecturers to the use of Texas Instruments emulators as virtual graphing calculators. These may be used in multimedia lectures to instruct students on the use of their graphing calculators to obtain solutions to complex chemical problems. (Contains 1 figure.)

  13. Identification of Chemical-Genetic Interactions via Parallel Analysis of Barcoded Yeast Strains.

    Science.gov (United States)

    Suresh, Sundari; Schlecht, Ulrich; Xu, Weihong; Miranda, Molly; Davis, Ronald W; Nislow, Corey; Giaever, Guri; St Onge, Robert P

    2016-01-01

    The Yeast Knockout Collection is a complete set of gene deletion strains for the budding yeast, Saccharomyces cerevisiae In each strain, one of approximately 6000 open-reading frames is replaced with a dominant selectable marker flanked by two DNA barcodes. These barcodes, which are unique to each gene, allow the growth of thousands of strains to be individually measured from a single pooled culture. The collection, and other resources that followed, has ushered in a new era in chemical biology, enabling unbiased and systematic identification of chemical-genetic interactions (CGIs) with remarkable ease. CGIs link bioactive compounds to biological processes, and hence can reveal the mechanism of action of growth-inhibitory compounds in vivo, including those of antifungal, antibiotic, and anticancer drugs. The chemogenomic profiling method described here measures the sensitivity induced in yeast heterozygous and homozygous deletion strains in the presence of a chemical inhibitor of growth (termed haploinsufficiency profiling and homozygous profiling, respectively, or HIPHOP). The protocol is both scalable and amenable to automation. After competitive growth of yeast knockout collection cultures, with and without chemical inhibitors, CGIs can be identified and quantified using either array- or sequencing-based approaches as described here. PMID:27587778

  14. Towards an integrated biosensor array for simultaneous and rapid multi-analysis of endocrine disrupting chemicals

    International Nuclear Information System (INIS)

    Highlights: ► A multitask biosensor for the detection of endocrine disrupting chemicals is proposed. ► The sensing system employ an array of biological recognition elements. ► Amperometric and optical transduction methods are provided in an integrated biosensor together with flow control systems. ► The biosensing device results in an integrated, automatic and portable system for environmental and agrifood application. - Abstract: In this paper we propose the construction and application of a portable multi-purpose biosensor array for the simultaneous detection of a wide range of endocrine disruptor chemicals (EDCs), based on the recognition operated by various enzymes and microorganisms. The developed biosensor combines both electrochemical and optical transduction systems, in order to increase the number of chemical species which can be monitored. Considering to the maximum residue level (MRL) of contaminants established by the European Commission, the biosensor system was able to detect most of the chemicals analysed with very high sensitivity. In particular, atrazine and diuron were detected with a limit of detection of 0.5 nM, with an RSD% less than 5%; paraoxon and chlorpyrifos were revealed with a detection of 5 μM and 4.5 μM, respectively, with an RSD% less than 6%; catechol and bisphenol A were identified with a limit of detection of 1 μM and 35 μM respectively, with an RSD% less than 5%.

  15. ECO LOGIC INTERNATIONAL GAS-PHASE CHEMICAL REDUCTION PROCESS - THE THERMAL DESORPTION UNIT - APPLICATIONS ANALYSIS REPORT

    Science.gov (United States)

    ELI ECO Logic International, Inc.'s Thermal Desorption Unit (TDU) is specifically designed for use with Eco Logic's Gas Phase Chemical Reduction Process. The technology uses an externally heated bath of molten tin in a hydrogen atmosphere to desorb hazardous organic compounds fro...

  16. ECO LOGIC INTERNATIONAL GAS-PHASE CHEMICAL REDUCTION PROCESS - THE REACTOR SYSTEM - APPLICATIONS ANALYSIS REPORT

    Science.gov (United States)

    The ELI Eco Logic International Inc. (Eco Logic) process thermally separates organics, then chemically reduces them in a hydrogen atmosphere, converting them to a reformed gas that consists of light hydrocarbons and water. A scrubber treats the reformed gas to remove hydrogen chl...

  17. Sustainability in the Design, Synthesis and Analysis of Chemical Engineering Processes 1st edition

    Science.gov (United States)

    This book preface explains the needs found by the book editors for assembling the state of the art of technical and scientific knowledge relevant to chemical engineering, sustainability, and sustainable uses of wastes and materials management, and to do so in an accessible and c...

  18. Towards an integrated biosensor array for simultaneous and rapid multi-analysis of endocrine disrupting chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Scognamiglio, Viviana, E-mail: viviana.scognamiglio@mlib.ic.cnr.it [IC-CNR Istituto di Cristallografia, AdR1 Dipartimento Agroalimentare - Via Salaria Km 29.3 00015, Rome (Italy); Pezzotti, Italo; Pezzotti, Gianni; Cano, Juan; Manfredonia, Ivano [Biosensor S.r.l. - Via degli Olmetti 44 00060 Formello, Rome (Italy); Buonasera, Katia [IC-CNR Istituto di Cristallografia, AdR1 Dipartimento Agroalimentare - Via Salaria Km 29.3 00015, Rome (Italy); Arduini, Fabiana; Moscone, Danila; Palleschi, Giuseppe [Universita di Roma Tor Vergata, Dipartimento di Scienze e Tecnologie Chimiche - Via della Ricerca Scientifica 00133, Rome (Italy); Giardi, Maria Teresa [IC-CNR Istituto di Cristallografia, AdR1 Dipartimento Agroalimentare - Via Salaria Km 29.3 00015, Rome (Italy)

    2012-11-02

    Highlights: Black-Right-Pointing-Pointer A multitask biosensor for the detection of endocrine disrupting chemicals is proposed. Black-Right-Pointing-Pointer The sensing system employ an array of biological recognition elements. Black-Right-Pointing-Pointer Amperometric and optical transduction methods are provided in an integrated biosensor together with flow control systems. Black-Right-Pointing-Pointer The biosensing device results in an integrated, automatic and portable system for environmental and agrifood application. - Abstract: In this paper we propose the construction and application of a portable multi-purpose biosensor array for the simultaneous detection of a wide range of endocrine disruptor chemicals (EDCs), based on the recognition operated by various enzymes and microorganisms. The developed biosensor combines both electrochemical and optical transduction systems, in order to increase the number of chemical species which can be monitored. Considering to the maximum residue level (MRL) of contaminants established by the European Commission, the biosensor system was able to detect most of the chemicals analysed with very high sensitivity. In particular, atrazine and diuron were detected with a limit of detection of 0.5 nM, with an RSD% less than 5%; paraoxon and chlorpyrifos were revealed with a detection of 5 {mu}M and 4.5 {mu}M, respectively, with an RSD% less than 6%; catechol and bisphenol A were identified with a limit of detection of 1 {mu}M and 35 {mu}M respectively, with an RSD% less than 5%.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-05-01

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

  20. Test results of chemical reactivity test (CRT) analysis of structural materials and explosives

    Energy Technology Data Exchange (ETDEWEB)

    Back, P.S.; Barnhart, B.V.; Walters, R.R.; Haws, L.D.; Collins, L.W.

    1980-03-21

    The chemical reactivity test, CRT, is a procedure used to screen the compatibility of component structure materials with explosives. This report contains the results of CRT materials evaluations conducted at Mound Facility. Data about materials combinations are catalogued both under the name of the explosive and the nonexplosive.