WorldWideScience

Sample records for utilizing accelerator mass

  1. Mass spectrometry with accelerators.

    Science.gov (United States)

    Litherland, A E; Zhao, X-L; Kieser, W E

    2011-01-01

    As one in a series of articles on Canadian contributions to mass spectrometry, this review begins with an outline of the history of accelerator mass spectrometry (AMS), noting roles played by researchers at three Canadian AMS laboratories. After a description of the unique features of AMS, three examples, (14)C, (10)Be, and (129)I are given to illustrate the methods. The capabilities of mass spectrometry have been extended by the addition of atomic isobar selection, molecular isobar attenuation, further ion acceleration, followed by ion detection and ion identification at essentially zero dark current or ion flux. This has been accomplished by exploiting the techniques and accelerators of atomic and nuclear physics. In 1939, the first principles of AMS were established using a cyclotron. In 1977 the selection of isobars in the ion source was established when it was shown that the (14)N(-) ion was very unstable, or extremely difficult to create, making a tandem electrostatic accelerator highly suitable for assisting the mass spectrometric measurement of the rare long-lived radioactive isotope (14)C in the environment. This observation, together with the large attenuation of the molecular isobars (13)CH(-) and (12)CH 2(-) during tandem acceleration and the observed very low background contamination from the ion source, was found to facilitate the mass spectrometry of (14)C to at least a level of (14)C/C ~ 6 × 10(-16), the equivalent of a radiocarbon age of 60,000 years. Tandem Accelerator Mass Spectrometry, or AMS, has now made possible the accurate radiocarbon dating of milligram-sized carbon samples by ion counting as well as dating and tracing with many other long-lived radioactive isotopes such as (10)Be, (26)Al, (36)Cl, and (129)I. The difficulty of obtaining large anion currents with low electron affinities and the difficulties of isobar separation, especially for the heavier mass ions, has prompted the use of molecular anions and the search for alternative

  2. Accelerator mass spectrometry.

    Science.gov (United States)

    Hellborg, Ragnar; Skog, Göran

    2008-01-01

    In this overview the technique of accelerator mass spectrometry (AMS) and its use are described. AMS is a highly sensitive method of counting atoms. It is used to detect very low concentrations of natural isotopic abundances (typically in the range between 10(-12) and 10(-16)) of both radionuclides and stable nuclides. The main advantages of AMS compared to conventional radiometric methods are the use of smaller samples (mg and even sub-mg size) and shorter measuring times (less than 1 hr). The equipment used for AMS is almost exclusively based on the electrostatic tandem accelerator, although some of the newest systems are based on a slightly different principle. Dedicated accelerators as well as older "nuclear physics machines" can be found in the 80 or so AMS laboratories in existence today. The most widely used isotope studied with AMS is 14C. Besides radiocarbon dating this isotope is used in climate studies, biomedicine applications and many other fields. More than 100,000 14C samples are measured per year. Other isotopes studied include 10Be, 26Al, 36Cl, 41Ca, 59Ni, 129I, U, and Pu. Although these measurements are important, the number of samples of these other isotopes measured each year is estimated to be less than 10% of the number of 14C samples. Copyright 2008 Wiley Periodicals, Inc.

  3. Laboratory of acceleration mass spectrometry

    International Nuclear Information System (INIS)

    Hybler, P.; Chrapan, J.

    2002-01-01

    In this paper authors describe the principle of the method of acceleration mass spectrometry and the construction plans of this instrument at the Faculty of ecology and environmental sciences in Banska Stiavnica. Using of this instrument for radiocarbon dating is discussed. A review of laboratories with acceleration mass spectrometry is presented

  4. Symposium on accelerator mass spectrometry

    International Nuclear Information System (INIS)

    1981-01-01

    The area of accelerator mass spectrometry has expanded considerably over the past few years and established itself as an independent and interdisciplinary research field. Three years have passed since the first meeting was held at Rochester. A Symposium on Accelerator Mass Spectrometry was held at Argonne on May 11-13, 1981. In attendance were 96 scientists of whom 26 were from outside the United States. The present proceedings document the program and excitement of the field. Papers are arranged according to the original program. A few papers not presented at the meeting have been added to complete the information on the status of accelerator mass spectrometry. Individual papers were prepared separately for the data base

  5. Symposium on accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-01-01

    The area of accelerator mass spectrometry has expanded considerably over the past few years and established itself as an independent and interdisciplinary research field. Three years have passed since the first meeting was held at Rochester. A Symposium on Accelerator Mass Spectrometry was held at Argonne on May 11-13, 1981. In attendance were 96 scientists of whom 26 were from outside the United States. The present proceedings document the program and excitement of the field. Papers are arranged according to the original program. A few papers not presented at the meeting have been added to complete the information on the status of accelerator mass spectrometry. Individual papers were prepared separately for the data base.

  6. Mass spectrometry with particle accelerator

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    The heavy ion accelerator use is renewing the ultrasensitive mass spectrometry in extending the detection limits. These new devices allow the measurement of rare isotope ratio, as 10 Be, 14 C, 26 Al, 36 Cl or 41 Ca, from the earth natural reservoirs [fr

  7. Accelerator-based ultrasensitive mass spectrometry

    International Nuclear Information System (INIS)

    Gove, H.E.

    1985-01-01

    This chapter describes a new mass spectrometry technique involving charged particle accelerators normally used for basic research in nuclear science. Topics considered include the limitations of conventional mass spectrometry, the limitations of the direct measurement of radioactive decay, mass spectrometry using a tandem electrostatic accelerator, mass spectrometry using a cyclotron, how accelerator mass spectrometry circumvents the limitations of conventional mass spectrometry, measurements of stable isotopes, nuclear physics and astrophysics applications, modifications to existing accelerators, descriptions of dedicated systems, and future applications

  8. Principle of accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Matsuzaki, Hiroyuki

    2007-01-01

    The principle of accelerator mass spectrometry (AMS) is described mainly on technical aspects: hardware construction of AMS, measurement of isotope ratio, sensitivity of measurement (measuring limit), measuring accuracy, and application of data. The content may be summarized as follows: rare isotope (often long-lived radioactive isotope) can be detected by various use of the ion energy obtained by the acceleration of ions, a measurable isotope ratio is one of rare isotope to abundant isotopes, and a measured value of isotope ratio is uncertainty to true one. Such a fact must be kept in mind on the use of AMS data to application research. (M.H.)

  9. Accelerator mass spectrometry in NIPNE

    International Nuclear Information System (INIS)

    Ivascu, M; Marinescu, L.; Dima, R.; Cata-Danil, D.; Petrascu, M.; Popescu, I.; Stan-Sion, C.; Radulescu, M.; Plostinaru, D.

    1997-01-01

    The Accelerator Mass Spectrometry (AMS) is today the method capable to measure the lowest concentration of a particular nuclide in sample materials. The method has applications in environmental physics, medicine, measurements of cosmic-ray or nuclear power plant produced radionuclides in the earth's atmosphere. All over the world, more than 40 charged particles and heavy ion accelerators are performing such analyses concerning the research interest of a huge number of laboratories. The Romanian Institute of Nuclear Physics and Engineering in Bucharest has initiated a construction project for the AMS facility at the FN - Van de Graaff Tandem accelerator. This program benefits of technical and financial assistance provided by IAEA in the frame of the IAEA-TC Project ROM 8014-265C. A general lay-out of the AMS project is presented. The construction work has begun and first tests of the AMS injector will take place between July - September this year. (authors)

  10. Accelerator mass spectrometry at the Rossendorf 5 MV tandem accelerator

    International Nuclear Information System (INIS)

    Friedrich, M.; Buerger, W.; Curian, H.; Hartmann, B.; Hentschel, E.; Matthes, H.; Probst, W.; Seidel, M.; Turuc, S.; Hebert, D.; Rothe, T.; Stolz, W.

    1992-01-01

    The Rossendorf electrostatic accelerators (5 MV tandem accelerator and single ended 2 MV van de Graaff accelerator) are already used for ion beam analysis. The existing methods (RBS, PIXE, ERDA, NRA, nuclear microprobe and external beam) will be completed by introduction of Accelerator Mass Spectrometry (AMS). A short description of the Rossendorf AMS system is given and first experimental results are presented. (R.P.) 4 refs.; 6 figs

  11. Subattomole sensitivity in biological accelerator mass spectrometry.

    Science.gov (United States)

    Salehpour, Mehran; Possnert, Göran; Bryhni, Helge

    2008-05-15

    The Uppsala University 5 MV Pelletron tandem accelerator has been used to study (14)C-labeled biological samples utilizing accelerator mass spectrometry (AMS) technology. We have adapted a sample preparation method for small biological samples down to a few tens of micrograms of carbon, involving among others, miniaturizing of the graphitization reactor. Standard AMS requires about 1 mg of carbon with a limit of quantitation of about 10 amol. Results are presented for a range of small sample sizes with concentrations down to below 1 pM of a pharmaceutical substance in human blood. It is shown that (14)C-labeled molecular markers can be routinely measured from the femtomole range down to a few hundred zeptomole (10 (-21) mol), without the use of any additional separation methods.

  12. Atom counting with accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Kutschera, Walter

    1995-01-01

    A brief review of the current status and some recent applications of accelerator mass spectrometry (AMS) are presented. Some connections to resonance ionization mass spectroscopy (RIS) as the alternate atom counting method are discussed

  13. New applications of accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Davis, J.C.

    1991-01-01

    Since its invention in the late 70's, and reduction to near-routine practice by the mid-80's, accelerator mass spectrometry (AMS) has become a powerful tool for archaeological and geochemical measurements in which cosmogenic isotopes such as 10 Be, 14 C, 26 Al, 36 Cl and 129 I are used as either tracers or chronometers. The utility of such measurements is demonstrated by the fact that most accelerators having AMS capabilities have significant backlogs of samples awaiting measurement. In designing and justifying a new accelerator facility in which AMS was to be a major feature, we sought to advance the field and increase the resources available for it by two steps: (1) development of new research applications in which intentionally added isotopic labels were used rather than just naturally present ones; and (2) enhancement of spectrometer throughout, making new classes of experiments possible by greatly increasing the number of samples that could be measured in individual experiments. Results of the effort to date suggest that development of a family of very small spectrometers optimized for just tritium and/or radiocarbon will be attractive in the near future

  14. International symposium on utilization of accelerators. Proceedings

    International Nuclear Information System (INIS)

    2003-01-01

    The programme of the IAEA in the Utilization of Low Energy Accelerators is implemented through the Department of Nuclear Sciences and Applications and the Department of Technical Cooperation. One aspect of the IAEA programme is to conduct symposia to highlight new developments, promote training and transfer of technology. Particle accelerators, originally developed for basic research in nuclear physics, have matured into versatile tools for applications in other branches of science, as well as in industry and medicine. In terms of numbers, electron accelerators have achieved the greatest usage being applied routinely for tasks like polymerisation of plastics, waste and flue gas treatment and sterilization of foodstuffs and medical devices. In addition, they are in widespread use in hospitals for cancer treatment. In the electronics industry, ion accelerators are utilized for implanting atoms into the surface layer of semiconductor materials. Ion implanters are also used for hardening metallic surfaces for medical implants and bearings. In the medical field, medium energy cyclotrons are used to produce isotopes for diagnostic, as well as, therapeutic applications. Recently, there has been an increased interest in proton accelerators with energies of a few hundred MeV for the treatment of deep lying tumours. Protons deposit most of their energy near the end of their path minimizing the radiation dose to surface tissue and vital organs that must be crossed to reach the target zone. Synchrotron radiation sources utilize high energy electrons that can be contained for many hours in storage rings in conjunction with specialized magnetic systems to emit synchrotron radiation in the wavelength range from infrared to X rays. Synchrotron radiation is used increasingly in macromolecular crystallography to locate the position of atoms in large protein molecules, to facilitate the understanding of the human genome and to design new anti-viral drugs. Synchrotron based X ray

  15. Accelerator mass spectrometry programme at BARC-TIFR pelletron accelerator

    International Nuclear Information System (INIS)

    Surendran, P.; Shrivastava, A.; Gupta, A.K.; Nair, J.P.; Yadav, M.L.; Gore, J.A.; Sparrow, H.; Bhagwat, P.V.; Kailas, S.

    2006-01-01

    Accelerator based mass spectrometry (ABMs) is an ultra sensitive means of counting individual atoms having sufficiently long half life and available in small amount. The 14 U D Pelletron Accelerator is an ideal machine to carry out ABMs studies with heavy isotopes like 36 Cl and 129 I. Cosmogenic radio isotope 36 Cl is widely being detected using ABMs as it has got applications in ground water research, radioactive waste management, atmospheric 36 Cl transport mechanism studies of Arctic Alpine ice core etc. As a part of the ongoing ABMs programme at 14UD Pelletron Accelerator Facility at Mumbai, a segmented gas detector developed for identification of 36 Cl was tested for performance. Recently a beam chopper required for this measurement has been developed. Further progress made in this programme is discussed in this paper. (author)

  16. Mass spectrometry by means of tandem accelerators

    International Nuclear Information System (INIS)

    Tuniz, C.

    1985-01-01

    Mass spectrometry based on an accelerator allows to measure rare cosmogenic isotopes found in natural samples with isotopic abundances up to 10E-15. The XTU Tandem of Legnaro National Laboratories can measure mean heavy isotopes (36Cl, 41Ca, 129I) in applications interesting cosmochronology and Medicine. The TTT-3 Tandem of the Naples University has been modified in view of precision studies of C14 in Archeology, Paleantology and Geology. In this paper a review is made of principles and methodologies and of some applicationy in the framework of the National Program for mass spectrametry research with the aid of accelerators

  17. Radiocarbon accelerator mass spectrometry: background and contamination

    International Nuclear Information System (INIS)

    Beukens, R.P.

    1993-01-01

    Since the advent of radiocarbon accelerator mass spectrometry (AMS) many studies have been conducted to understand the background from mass spectrometric processes and the origins of contamination associated with the ion source and sample preparation. By studying the individual contributions a better understanding of these processes has been obtained and it has been demonstrated that it is possible to date samples reliably up to 60 000 BP. (orig.)

  18. A New Accelerator-Based Mass Spectrometry.

    Science.gov (United States)

    Gove, H. E.

    1983-01-01

    Tandem electrostatic accelerators produce beams of positive ions which are used to penetrate atomic nuclei in a target, inducing nuclear reactions whose study elucidates varied properties of the nucleus. Uses of the system, which acts like a mass spectrometer, are discussed. These include radiocarbon dating measurements. (JN)

  19. Accelerator mass spectrometry: state of the art

    Energy Technology Data Exchange (ETDEWEB)

    Tuniz, C. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1996-12-31

    Accelerator Mass Spectrometry (AMS) is the analytical technique of choice for the detection of long-lived radionuclides which cannot be practically analysed with decay counting or conventional mass spectrometry. The main use of AMS has been in the analysis of radiocarbon and other cosmogenic radionuclides for archaeological, geological and environmental applications. In addition, AMS has been recently applied in biomedicine to study exposure of human tissues to chemicals and biomolecules at attomole levels. There is also a world-wide effort to analyse rare nuclides of heavier masses, such as long-lived actinides, with important applications in safeguards and nuclear waste disposal. The use of AMS is limited by the expensive accelerator technology required and there are several attempts to develop smaller and cheaper AMS spectrometers. 5 refs.

  20. Accelerator mass spectrometry: state of the art

    Energy Technology Data Exchange (ETDEWEB)

    Tuniz, C [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1997-12-31

    Accelerator Mass Spectrometry (AMS) is the analytical technique of choice for the detection of long-lived radionuclides which cannot be practically analysed with decay counting or conventional mass spectrometry. The main use of AMS has been in the analysis of radiocarbon and other cosmogenic radionuclides for archaeological, geological and environmental applications. In addition, AMS has been recently applied in biomedicine to study exposure of human tissues to chemicals and biomolecules at attomole levels. There is also a world-wide effort to analyse rare nuclides of heavier masses, such as long-lived actinides, with important applications in safeguards and nuclear waste disposal. The use of AMS is limited by the expensive accelerator technology required and there are several attempts to develop smaller and cheaper AMS spectrometers. 5 refs.

  1. Electromagnetic projectile acceleration utilizing distributed energy sources

    International Nuclear Information System (INIS)

    Parker, J.V.

    1982-01-01

    Circuit equations are derived for an electromagnetic projectile accelerator (railgun) powered by a large number of capacitive discharge circuits distributed along its length. The circuit equations are put into dimensionless form and the parameters governing the solutions derived. After specializing the equations to constant spacing between circuits, the case of lossless rails and negligible drag is analyzed to show that the electrical to kinetic energy transfer efficiency is equal to sigma/2, where sigma = 2mS/Lq 2 0 and m is the projectile mass, S the distance between discharge circuit, Lthe rail inductance per unit length, and q 0 the charge on the first stage capacitor. For sigma = 2 complete transfer of electrical to kinetic energy is predicted while for sigma>2 the projective-discharge circuit system is unstable. Numerical solutions are presented for both lossless rails and for finite rail resistance. When rail resistance is included, >70% transfer is calculated for accelerators of arbitrary length. The problem of projectile startup is considered and a simple modification of the first two stages is described which provides proper startup. Finally, the results of the numerical solutions are applied to a practical railgun design. A research railgun designed for repeated operation at 50 km/sec is described. It would have an overall length of 77 m, an electrical efficiency of 81%, a stored energy per stage of 105 kJ, and a charge transfer of <50 C per stage. A railgun of this design appears to be practicable with current pulsed power technology

  2. Accelerator mass spectrometry - From DNA to astrophysics

    International Nuclear Information System (INIS)

    Kutschera, W.

    2013-01-01

    A brief review of accelerator mass spectrometry (AMS) is presented. The present work touches on a few technical aspects and recent developments of AMS, and describes two specific applications of AMS, the dating of human DNA with the 14 C bomb peak and the search for superheavy elements in nature. Since two extended general reviews on technical developments in AMS [1] and applications of AMS [2] will appear in 2013, frequent reference to these reviews is made. (authors)

  3. The Study of Expert System Utilization for the Accelerator Operation

    International Nuclear Information System (INIS)

    Budi-Santosa; Slamet-Santosa; Subari-Santosa

    2000-01-01

    The utilization of expert system in the accelerator laboratory has been studied. The study covers the utilization of expert system in the setting up experiment (tuning parameter), controlling system, safety or warning system. The results study shows, that using the expert system in the accelerator would be easy to operate the accelerator for user and operator. Increasing the skill of expert system could be updated without logical mechanism modification. (author)

  4. Heavy-ion accelerator mass spectrometry with a 'small' accelerator

    International Nuclear Information System (INIS)

    Steier, P.; Golser, R.; Priller, A.; Vockenhuber, C.; Irlweck, K.; Kutschera, W.; Lichtenstein, V.

    2001-01-01

    Full text: VERA, the Vienna environmental research accelerator, is based on a 3-MV pelletron tandem accelerator and is designed to allow the transport of ions of all elements, from the lightest to the heaviest. The VERA heavy ion program tries to establish measurement methods which work for the long-lived radionuclides where suppression of isobars is not required. Among these are 129 I, 210 Pb, 236 U and all heavier ions where no stable isobars exist. To suppress neighboring masses, the resolution of VERA was increased, both by improving the ion optics of existing elements and by installing a new electrostatic separator after the analyzing magnet. Interfering ions which pass all beam filters are identified with a high-resolution time-of-flight system, using a 0.5 μg/cm 2 DLC (diamond-like carbon) foil in the start detector, which substantially reduces beam straggling. Compared to heavy ion AMS at large tandem accelerators (TV ≥ 8 MV) and for cases where stable isobar interference is absent, it is possible to offset the disadvantage of lower ion energy. Moreover, the more compact facilities like VERA achieve higher stability and reliability and provide advanced computer control. This promises even higher precision and sensitivity for a larger number of samples, which is a prerequisite for research on natural-occurring heavy radioisotopes at environmental levels. First results on the measurement of 210 Pb (half-life 22 a) and 236 U (23 Ma) encourages us to push towards even heavier radionuclides (e.g. 224 Pu, 81 Ma). (author)

  5. High-sensitivity mass spectrometry with a tandem accelerator

    International Nuclear Information System (INIS)

    Henning, W.

    1984-01-01

    The characteristic features of accelerator mass spectrometry are discussed. A short overview is given of the current status of mass spectrometry with high-energy (MeV/nucleon) heavy-ion accelerators. Emphasis is placed on studies with tandem accelerators and on future mass spectrometry of heavier isotopes with the new generation of higher-voltage tandems

  6. Continuous-flow accelerator mass spectrometry for radiocarbon analysis

    International Nuclear Information System (INIS)

    Wills, J.S.C.; Han, B.X.; Von Reden, K.F.; Schneider, R.J.; Roberts, M.L.

    2006-01-01

    Accelerator Mass Spectrometry (AMS) is a widely used technique for radiocarbon dating of archaeological or environmental samples that are very small or very old (up to 50,000 years before present). Because of the method's extreme sensitivity, AMS can also serve as an environmental tracer and supplements conventional nuclear counting techniques for monitoring 14 C emissions from operating nuclear power plants and waste repositories. The utility of present AMS systems is limited by the complex sample preparation process required. Carbon from combusted artefacts must be incorporated into a solid metallic target from which a negative ion beam is produced and accelerated to MeV energies by an accelerator for subsequent analysis. This paper will describe a novel technique being developed by the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) Laboratory at the Woods Hole Oceanographic Institution for the production of negative carbon ion beams directly from a continuously flowing sample gas stream, eliminating the requirement for a solid target. A key component of the new technique is a microwave-driven, gaseous-feed ion source originally developed at Chalk River Laboratories for the very different requirements of a high current proton linear accelerator. A version of this ion source is now being adapted to serve as an injector for a dedicated AMS accelerator facility at NOSAMS. The paper begins with a review of the fundamentals of radiocarbon dating. Experiments carried out at NOSAMS with a prototype of the microwave ion source are described, including measurements of sample utilization efficiency and sample 'memory' effect. A new version of the microwave ion source, optimized for AMS, is also described. The report concludes with some predictions of new research opportunities that will become accessible to the technique of continuous-flow AMS. (author)

  7. Continuous-flow accelerator mass spectrometry for radiocarbon analysis

    International Nuclear Information System (INIS)

    Wills, J.S.C.; Han, B.X.; Von Reden, K.F.; Schneider, R.J.; Roberts, M.L.

    2006-05-01

    Accelerator Mass Spectrometry (AMS) is a widely used technique for radiocarbon dating of archaeological or environmental samples that are very small or very old (up to 50,000 years before present). Because of the method's extreme sensitivity, AMS can also serve as an environmental tracer and supplements conventional nuclear counting techniques for monitoring 14 C emissions from operating nuclear power plants and waste repositories. The utility of present AMS systems is limited by the complex sample preparation process required. Carbon from combusted artefacts must be incorporated into a solid metallic target from which a negative ion beam is produced and accelerated to MeV energies by an accelerator for subsequent analysis. This paper will describe a novel technique being developed by the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) Laboratory at the Woods Hole Oceanographic Institution for the production of negative carbon ion beams directly from a continuously flowing sample gas stream, eliminating the requirement for a solid target. A key component of the new technique is a microwave-driven, gaseous-feed ion source originally developed at Chalk River Laboratories for the very different requirements of a high current proton linear accelerator. A version of this ion source is now being adapted to serve as an injector for a dedicated AMS accelerator facility at NOSAMS. The paper begins with a review of the fundamentals of radiocarbon dating. Experiments carried out at NOSAMS with a prototype of the microwave ion source are described, including measurements of sample utilization efficiency and sample 'memory' effect. A new version of the microwave ion source, optimized for AMS, is also described. The report concludes with some predictions of new research opportunities that will become accessible to the technique of continuous-flow AMS. (author)

  8. Accelerator mass spectrometry for radiocarbon dating

    International Nuclear Information System (INIS)

    Bronk, C.R.

    1987-01-01

    Accelerator mass spectrometry (AMS) has been used routinely for radiocarbon measurements for several years. This thesis describes theoretical work to understand the reasons for low accuracy and range and offers practical solutions. The production and transport of the ions used in the measurements are found to be the most crucial stages in the process. The theories behind ion production by sputtering are discussed and applied to the specific case of carbon sputtered by caesium. Experimental evidence is also examined in relation to the theories. The phenomena of space charge and lens aberrations are discussed along with the interaction between ion beams and gas molecules in the vacuum. Computer programs for calculating phase space transformations are then described; these are designed to help investigations of the effects of space charge and aberrations on AMS measurements. Calculations using these programs are discussed in relation both to measured ion beam profiles in phase space and to the current dependent transmission of ions through the Oxford radiocarbon accelerator. Improvements have been made to this accelerator and these are discussed in the context of the calculations. C - ions are produced directly from carbon dioxide at the Middleton High Intensity Sputter Source. Experiments to evaluate the performance of such a source are described and detailed design criteria established. An ion source designed and built specifically for radiocarbon measurements using carbon dioxide is described. Experiments to evaluate its performance and investigate the underlying physical processes are discussed. (author)

  9. 14C Accelerator mass spectrometry in Brazil

    International Nuclear Information System (INIS)

    Macario, K.D.; Gomes, P.R.S.; Anjos, Roberto M.; Linares, R.; Queiroz, E.A.; Oliveira, F.M.; Cardozo, L.; Carvalho, C.R.A.

    2011-01-01

    Radiocarbon Accelerator Mass Spectrometry is an ultra-sensitive technique that enables the direct measurement of carbon isotopes in samples as small as a few milligrams. The possibility of dating or tracing rare or even compound specific carbon samples has application in many fields of science such as Archaeology, Geosciences and Biomedicine. Several kinds of material such as wood, charcoal, carbonate and bone can be chemically treated and converted to graphite to be measured in the accelerator system. The Physics Institute of Universidade Federal Fluminense (UFF), in Brazil will soon be able to perform the complete 14 C-AMS measurement of samples. At the Nuclear Chronology Laboratory (LACRON) samples are prepared and converted to carbon dioxide. A stainless steel vacuum system was constructed for carbon dioxide purification and graphitization is performed in sealed tubes in a muffle oven. Graphite samples will be analyzed in a 250 kV Single Stage Accelerator produced by National Electrostatic Corporation which will be installed in the beginning of 2012. With the sample preparation laboratory at LACRON and the SSAMS system, the Physics Institute of UFF will be the first 14 C-AMS facility in Latin America. (author)

  10. Utilizing GPUs to Accelerate Turbomachinery CFD Codes

    Science.gov (United States)

    MacCalla, Weylin; Kulkarni, Sameer

    2016-01-01

    GPU computing has established itself as a way to accelerate parallel codes in the high performance computing world. This work focuses on speeding up APNASA, a legacy CFD code used at NASA Glenn Research Center, while also drawing conclusions about the nature of GPU computing and the requirements to make GPGPU worthwhile on legacy codes. Rewriting and restructuring of the source code was avoided to limit the introduction of new bugs. The code was profiled and investigated for parallelization potential, then OpenACC directives were used to indicate parallel parts of the code. The use of OpenACC directives was not able to reduce the runtime of APNASA on either the NVIDIA Tesla discrete graphics card, or the AMD accelerated processing unit. Additionally, it was found that in order to justify the use of GPGPU, the amount of parallel work being done within a kernel would have to greatly exceed the work being done by any one portion of the APNASA code. It was determined that in order for an application like APNASA to be accelerated on the GPU, it should not be modular in nature, and the parallel portions of the code must contain a large portion of the code's computation time.

  11. Accelerator science and its civil and utility engineering work

    International Nuclear Information System (INIS)

    Yoshioka, Masakazu

    2006-01-01

    In large-scale accelerator projects such as TRISTAN and J-PARC, approximately half of the total project costs are spent on the civil and utility engineering work for the accelerator. In addition, the quality of civil and utility engineering has a large effect on the quality of the beam. With increasing scale of projects, there is growing specialization of the people in charge of the accelerator on the one hand, and the people in charge of civil and utility engineering on the other. Mutual understanding between the people in charge is therefore important in such cases. From the experience I have accumulated working on the facilities of many large projects, I have become keenly aware of the necessity for both accelerator-literate civil engineering specialists and civil engineering-literate accelerator researchers. A straight-forward method for satisfying this requirement is to systematize accelerator science as a science with civil and utility engineering for accelerators recognized as its sub-field. When new projects launched, the methodology of the natural sciences should be incorporated whereby past experience is fully utilized and then new technologies and knowledge are accumulated. (author)

  12. Accelerator mass spectrometry of small biological samples.

    Science.gov (United States)

    Salehpour, Mehran; Forsgard, Niklas; Possnert, Göran

    2008-12-01

    Accelerator mass spectrometry (AMS) is an ultra-sensitive technique for isotopic ratio measurements. In the biomedical field, AMS can be used to measure femtomolar concentrations of labeled drugs in body fluids, with direct applications in early drug development such as Microdosing. Likewise, the regenerative properties of cells which are of fundamental significance in stem-cell research can be determined with an accuracy of a few years by AMS analysis of human DNA. However, AMS nominally requires about 1 mg of carbon per sample which is not always available when dealing with specific body substances such as localized, organ-specific DNA samples. Consequently, it is of analytical interest to develop methods for the routine analysis of small samples in the range of a few tens of microg. We have used a 5 MV Pelletron tandem accelerator to study small biological samples using AMS. Different methods are presented and compared. A (12)C-carrier sample preparation method is described which is potentially more sensitive and less susceptible to contamination than the standard procedures.

  13. Calibration samples for accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Hershberger, R.L.; Flynn, D.S.; Gabbard, F.

    1981-01-01

    Radioactive samples with precisely known numbers of atoms are useful as calibration sources for lifetime measurements using accelerator mass spectrometry. Such samples can be obtained in two ways: either by measuring the production rate as the sample is created or by measuring the decay rate after the sample has been obtained. The latter method requires that a large sample be produced and that the decay constant be accurately known. The former method is a useful and independent alternative, especially when the decay constant is not well known. The facilities at the University of Kentucky for precision measurements of total neutron production cross sections offer a source of such calibration samples. The possibilities, while quite extensive, would be limited to the proton rich side of the line of stability because of the use of (p,n) and (α,n) reactions for sample production

  14. Radiocarbon dating with accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Blake, W. Jr.

    1985-01-01

    Radiocarbon dating by means of accelerator mass spectrometry (AMS) has two great advantages over conventional dating: 1) much smaller samples can be handled and 2) counting time is significantly shorter. Three examples are given for Holocene-age material from east-central Ellesmere Island. The results demonstrate the potential use of this technique as a powerful research tool in studies of Quaternary chronology. Individual fragments of marine shells as small as 0.1 g have been dated successfully at the IsoTrace Laboratory, University of Toronto. In the case of an aquatic moss from a lake sediment core, an increment 0.5 cm thick could be used instead of a 5 cm-thick slice, thus allowing a much more precise estimate of the onset of organic sedimentation

  15. Utilization of electron accelerator in the Philippines

    Energy Technology Data Exchange (ETDEWEB)

    Cabalfin, Estelita G. [Philippine Nuclear Research Institute, Quezon (Philippines)

    2003-02-01

    Radiosterilization of medical and surgical supplies, radiation treatment of consumer products such as food, pharmaceuticals and cosmetics, and the modification of polymers, crosslinking or curing, using gamma irradiation facilities in Philippine industries are overviewed. Philippine Nuclear Research Institute(PNRI) conducts bioburden determination, dose setting and validation of compatibility with radiation of product and packaging with the technical assistance of IAEA. The products with yields treated at the irradiation facility from 1996-2001 are shown in table. An electron accelerator of 10 MeV and 28 kW, established by Terumo Corporation, is used since 2000 for in-house radiation sterilization of syringes. Current regulations and regulatory authority in Philippines are also briefly introduced. Future processes such as radiation vulcanized natural rubber latex (RVNRL), use of carrageenan as hydrogel for dressing wounds and others and fermented bagasse as animal feed are now in progress. (S. Ohno)

  16. Utilization of electron accelerator in the Philippines

    International Nuclear Information System (INIS)

    Cabalfin, Estelita G.

    2003-01-01

    Radiosterilization of medical and surgical supplies, radiation treatment of consumer products such as food, pharmaceuticals and cosmetics, and the modification of polymers, crosslinking or curing, using gamma irradiation facilities in Philippine industries are overviewed. Philippine Nuclear Research Institute(PNRI) conducts bioburden determination, dose setting and validation of compatibility with radiation of product and packaging with the technical assistance of IAEA. The products with yields treated at the irradiation facility from 1996-2001 are shown in table. An electron accelerator of 10 MeV and 28 kW, established by Terumo Corporation, is used since 2000 for in-house radiation sterilization of syringes. Current regulations and regulatory authority in Philippines are also briefly introduced. Future processes such as radiation vulcanized natural rubber latex (RVNRL), use of carrageenan as hydrogel for dressing wounds and others and fermented bagasse as animal feed are now in progress. (S. Ohno)

  17. Accelerator mass analysis at tandem accelerator in Kyoto University

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Masanobu; Tazawa, Yuji; Matsumoto, Hiroshi; Hirose, Masanori [Kyoto Univ. (Japan). Faculty of Science; Ogino, Koya; Kohno, Masuchika; Funaba, Hiroyuki

    1996-12-01

    Tandem accelerator in Science Faculty, Kyoto University was renewed from 5 MV in the highest terminal voltage of Van de Graaff to 8 MV of Peletron in 1992. And, AMS effective for cosmic ray, dating, environment measurement and so forth is determined to a column of collaborative studies by universities and institutes in Japan. On this renewal, because of using high energy beam transportation of the present tandem accelerator, super high sensitivity measurement of long half-life radioactive isotopes of heavy elements such as {sup 36}Cl, {sup 41}Ca, {sup 129}I and so forth is aimed, although having some limitations due to small magnet. The accelerator is active in characteristics of the middle size tandem accelerator, and developing {sup 14}C measurement for its standard technology, as aiming at {sup 36}Cl measurement, at first. As a result, in this tandem accelerator stable and high beam transmittance could be obtained by adding a slit at negative ion source to make emittance of incident beam smaller. {sup 14}C/{sup 12}C ratio of Modan`s sample obtained by graphitizing NBS oxalic acid and Ded`s sample consisting of mineral graphite produced in Sri Lanka are measured to confirm better reproductivity of this system. Future development of successive incident method is planned to test actual carbon samples. (G.K.)

  18. Applications of accelerator mass spectrometry to nuclear physics and astrophysics

    International Nuclear Information System (INIS)

    Guo Zhiyu; Zhang Chuan

    2002-01-01

    As an ultra high sensitive analyzing method, accelerator mass spectrometry is playing an important role in the studies of nuclear physics and astrophysics. The accelerator mass spectrometry (AMS) applications in searching for violation of Pauli exclusion principle and study on supernovae are discussed as examples

  19. International symposium on utilization of accelerators. Book of extended synopses

    International Nuclear Information System (INIS)

    2001-01-01

    This book presents the extended synopses of papers presented at the International Symposium on Utilization of Accelerators hosted by the Government of Brazil through its Instituto de Pesquisas Energeticas e Nucleares (IPEN). The synopses are presented unedited as they were received from the authors. Abstracts are not available for all of the synopses. Separate analytics were prepared

  20. International symposium on utilization of accelerators. Book of extended synopses

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This book presents the extended synopses of papers presented at the International Symposium on Utilization of Accelerators hosted by the Government of Brazil through its Instituto de Pesquisas Energeticas e Nucleares (IPEN). The synopses are presented unedited as they were received from the authors. Abstracts are not available for all of the synopses. Separate analytics were prepared.

  1. Surface mass balance contributions to acceleration of Antarctic ice mass loss during 2003-2013

    OpenAIRE

    Seo, Ki-Weon; Wilson, Clark R.; Scambos, Ted; Kim, Baek-Min; Waliser, Duane E.; Tian, Baijun; Kim, Byeong-Hoon; Eom, Jooyoung

    2015-01-01

    Abstract Recent observations from satellite gravimetry (the Gravity Recovery and Climate Experiment (GRACE) mission) suggest an acceleration of ice mass loss from the Antarctic Ice Sheet (AIS). The contribution of surface mass balance changes (due to variable precipitation) is compared with GRACE?derived mass loss acceleration by assessing the estimated contribution of snow mass from meteorological reanalysis data. We find that over much of the continent, the acceleration can be explained by ...

  2. The international atomic energy agency's programme on utilization of accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Dytlewski, Nikolai [International Atomic Energy Agency, Wagramer Str. 5, A-1400 Vienna (Austria); Mank, Guenter [International Atomic Energy Agency, Wagramer Str. 5, A-1400 Vienna (Austria)]. E-mail: g.mank@iaea.org; Rosengard, Ulf [International Atomic Energy Agency, Wagramer Str. 5, A-1400 Vienna (Austria); Bamford, Samuel [International Atomic Energy Agency, Wagramer Str. 5, A-1400 Vienna (Austria); Markowicz, Andrzej [International Atomic Energy Agency, Wagramer Str. 5, A-1400 Vienna (Austria); Wegrzynek, Dariusz [International Atomic Energy Agency, Wagramer Str. 5, A-1400 Vienna (Austria)

    2006-06-23

    Low-energy accelerators have in the past produced a major part of our current knowledge of nuclear physics. Today they are mainly used for applied research and industrial applications. In view of this, the International Atomic Energy Agency (IAEA) has during recent years initiated several Coordinated Research Projects (CRPs) concerning Ion Beam Analysis of Materials, Accelerator Mass Spectrometry and Nuclear Microprobe Techniques. The CRPs involve laboratories from developing as well as developed Member States, networking on a common topic coordinated by the IAEA. In order to facilitate networking, the IAEA has recently published the 'World Survey of Accelerator Based Analytical Techniques' available on the Internet and as a CD-ROM. The IAEA maintains also a beamline at a 6 MV Van de Graaff accelerator in the Rudjer Boskovic Institute, Zagreb, Croatia. Small and medium power accelerator driven spallation neutron sources will become more important as many small neutron producing research reactors are approaching the end of their useful working life. The IAEA has, within its Department for Nuclear Sciences and Applications, a programme on the Effective Utilization of Accelerators. This programme helps Member States, in particular developing Member States, in finding new areas of applications for their low and medium energy accelerators through increased participation in activities such as Coordinated Research Projects, Technical Meetings and Conferences. This paper describes the IAEA's current programme on accelerator utilization and proposed future activities.

  3. Accelerator mass spectrometry and associated facilities at Inter-University Accelerator Centre, New Delhi, India

    International Nuclear Information System (INIS)

    Kumar, Pankaj; Bohra, Archna; Ojha, S.; Gargari, S.; Joshi, R.; Roonwal, G.S.; Chopra, S.; Pattanaik, J.K.; Balakrishnan, S.

    2011-01-01

    Accelerator Mass Spectrometry (AMS) facility at Inter-University Accelerator Centre (IUAC) is developed by upgrading its existing 15UD Pelletron accelerator. Since last two decades Pelletron is mainly used for nuclear physics, materials science, atomic physics, radiation biology and accelerator mass spectrometry is recent development. In addition, a chemistry laboratory in clean room for the chemical processing of samples for AMS studies has also been established. At present the AMS facility is used for 10 Be, 26 Al measurements and soon other long lived radio-isotopes will also be used

  4. A GPU Accelerated Spring Mass System for Surgical Simulation

    DEFF Research Database (Denmark)

    Mosegaard, Jesper; Sørensen, Thomas Sangild

    2005-01-01

    There is a growing demand for surgical simulators to dofast and precise calculations of tissue deformation to simulateincreasingly complex morphology in real-time. Unfortunately, evenfast spring-mass based systems have slow convergence rates for largemodels. This paper presents a method to accele...... to accelerate computation of aspring-mass system in order to simulate a complex organ such as theheart. This acceleration is achieved by taking advantage of moderngraphics processing units (GPU)....

  5. Utilization of accelerators for development of polymer materials

    International Nuclear Information System (INIS)

    Omichi, Hideki

    1987-01-01

    There are two processes in the development of polymer materials using accelerators. One is to induce graft polymerization by irradiating the electron beam of high dose rate, and another is to induce cross-linking or decomposition by irradiating on existing polymer materials. The former is mostly at the stage of research and development, while in the latter, the industrial utilization has advanced as bridged electric wires, foaming materials and thermal contraction materials. In this paper, the results of the basic research are mainly reported. The polymerization of vinyl monomers such as styrene easily advances by the irradiation of gamma ray or electron beam, accordingly, it is widely utilized as the object of basic research. When the plural radicals produced by the irradiation of polymers couple mutually or attach to double bonds, the polymer of large molecular weight arises, on the other hand, when radicals arise by the severance of main chains in polymers, the molecular weight decreases. The utilization of accelerators for the development of polymer materials is diversified. Hereafter, also particle accelerators will be used for this field. Already ion implantation, sputtering, hole-opening and so on for polymer materials began to be studied, and the new development of materials is expected. (Kako, I.)

  6. Accelerator mass spectrometry-current status in techniques and applications

    International Nuclear Information System (INIS)

    Imamura, Mineo; Nagai, Hisao; Kobayashi, Koichi.

    1991-01-01

    Accelerator mass spectrometry (AMS) is the mass spectrometry by incorporating an accelerator. After samples are ionized, they are accelerated to a certain energy, and mass, energy, nuclear charge (atomic number) are distinguished, and ion counting is made one by one with a heavy ion detector. For the measurement of long half-life radioisotopes, mass spectrometry has been used because of the high sensitivity, but in low energy mass spectrometry, there are the difficulties due to the mixing of the molecular ions having nearly same mass and the existence of isobars. One of the methods solving these difficulties is an accelerator which enables background-free measurement. The progress of AMS is briefly described, and at present, it is carried out in about 30 facilities in the world. In AMS, the analysis is carried out in the order of the ionization of samples, the acceleration of beam, the electron stripping with a thin film, the sorting of the momentum and energy of beam and the identification of particles. The efficiency, sensitivity and accuracy of detection and the application are reported. (K.I.)

  7. Leptoquarks: Neutrino masses and related accelerator signals

    International Nuclear Information System (INIS)

    Aristizabal Sierra, D.; Hirsch, M.; Kovalenko, S. G.

    2008-01-01

    Leptoquark-Higgs interactions induce mixing between leptoquark (LQ) states with different chiralities once the electroweak symmetry is broken. In such LQ models Majorana neutrino masses are generated at 1-loop order. Here we calculate the neutrino mass matrix and explore the constraints on the parameter space enforced by the assumption that LQ-loops explain current neutrino oscillation data. LQs will be produced at the CERN LHC, if their masses are at or below the TeV scale. Since the fermionic decays of LQs are governed by the same Yukawa couplings, which are responsible for the nontrivial neutrino mass matrix, several decay branching ratios of LQ states can be predicted from measured neutrino data. Especially interesting is that large lepton flavor violating rates in muon and tau final states are expected. In addition, the model predicts that, if kinematically possible, heavier LQs decay into lighter ones plus either a standard model Higgs boson or a Z 0 /W ± gauge boson. Thus, experiments at the LHC might be able to exclude the LQ mechanism as an explanation of neutrino data.

  8. Accelerator mass spectrometry in biomedical research

    International Nuclear Information System (INIS)

    Vogel, J.S.; Turteltaub, K.W.

    1993-01-01

    Biological effects occur in natural systems at chemical concentrations of parts per billion (1:10 9 ) or less. Affected biomolecules may be separable in only milligram or microgram quantities. Quantification at attomole sensitivity is needed to study these interactions. AMS measures isotope concentrations to parts per 10 13--15 on milligram-sized samples and is ideal for quantifying long-lived radioisotopic labels that are commonly used to trace biochemical pathways in natural systems. 14 C-AMS has now been coupled to a variety of organic separation and definition technologies. The primary research investigates pharmacokinetics and genotoxicities of toxins and drugs at very low doses. Human subject research using AMS includes nutrition, toxicity and elemental balance studies. 3 H, 41 Ca and 26 Al are also traced by AMS for fundamental biochemical kinetic research. Expansion of biomedical AMS awaits further development of biochemical and accelerator technologies designed specifically for these applications

  9. A statistical investigation of the mass discrepancy-acceleration relation

    Science.gov (United States)

    Desmond, Harry

    2017-02-01

    We use the mass discrepancy-acceleration relation (the correlation between the ratio of total-to-visible mass and acceleration in galaxies; MDAR) to test the galaxy-halo connection. We analyse the MDAR using a set of 16 statistics that quantify its four most important features: shape, scatter, the presence of a `characteristic acceleration scale', and the correlation of its residuals with other galaxy properties. We construct an empirical framework for the galaxy-halo connection in LCDM to generate predictions for these statistics, starting with conventional correlations (halo abundance matching; AM) and introducing more where required. Comparing to the SPARC data, we find that: (1) the approximate shape of the MDAR is readily reproduced by AM, and there is no evidence that the acceleration at which dark matter becomes negligible has less spread in the data than in AM mocks; (2) even under conservative assumptions, AM significantly overpredicts the scatter in the relation and its normalization at low acceleration, and furthermore positions dark matter too close to galaxies' centres on average; (3) the MDAR affords 2σ evidence for an anticorrelation of galaxy size and Hubble type with halo mass or concentration at fixed stellar mass. Our analysis lays the groundwork for a bottom-up determination of the galaxy-halo connection from relations such as the MDAR, provides concrete statistical tests for specific galaxy formation models, and brings into sharper focus the relative evidence accorded by galaxy kinematics to LCDM and modified gravity alternatives.

  10. Issues and opportunities in accelerator mass spectrometry for stable isotopes.

    Science.gov (United States)

    Matteson, Sam

    2008-01-01

    Accelerator mass spectrometry (AMS) has developed in the last 30 years many notable applications to the spectrometry of radioisotopes, particularly in radiocarbon dating. The instrumentation science of trace element AMS (TEAMS) that analyzes stable isotopes, also called Accelerator SIMS or MegaSIMS, while unique in many features, has also shared in many of these significant advances and has pushed TEAMS sensitivity to concentration levels surpassing many competing mass spectroscopic technologies. This review examines recent instrumentation developments, the capabilities of the new instrumentation and discernable trends for future development. Copyright 2008 Wiley Periodicals, Inc.

  11. Design of a ram accelerator mass launch system

    Science.gov (United States)

    Aarnio, Michael; Armerding, Calvin; Berschauer, Andrew; Christofferson, Erik; Clement, Paul; Gohd, Robin; Neely, Bret; Reed, David; Rodriguez, Carlos; Swanstrom, Fredrick

    1988-01-01

    The ram accelerator mass launch system has been proposed to greatly reduce the costs of placing acceleration-insensitive payloads into low earth orbit. The ram accelerator is a chemically propelled, impulsive mass launch system capable of efficiently accelerating relatively large masses from velocities of 0.7 km/sec to 10 km/sec. The principles of propulsion are based on those of a conventional supersonic air-breathing ramjet; however the device operates in a somewhat different manner. The payload carrying vehicle resembles the center-body of the ramjet and accelerates through a stationary tube which acts as the outer cowling. The tube is filled with premixed gaseous fuel and oxidizer mixtures that burn in the vicinity of the vehicle's base, producing a thrust which accelerates the vehicle through the tube. This study examines the requirement for placing a 2000 kg vehicle into a 500 km circular orbit with a minimum amount of on-board rocket propellant for orbital maneuvers. The goal is to achieve a 50 pct payload mass fraction. The proposed design requirements have several self-imposed constraints that define the vehicle and tube configurations. Structural considerations on the vehicle and tube wall dictate an upper acceleration limit of 1000 g's and a tube inside diameter of 1.0 m. In-tube propulsive requirements and vehicle structural constraints result in a vehicle diameter of 0.76 m, a total length of 7.5 m and a nose-cone half angle of 7 degrees. An ablating nose-cone constructed from carbon-carbon composite serves as the thermal protection mechanism for atmospheric transit.

  12. Tritium depth profiling in carbon by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Friedrich, M.; Pilz, W.; Sun, G.; Behrisch, R.; Garcia-Rosales, C.; Bekris, N.; Penzhorn, R.-D.

    2000-01-01

    Tritium depth profiling measurements by accelerator mass spectrometry have been performed at the facility installed at the Rossendorf 3 MV Tandetron. In order to achieve a uniform erosion at the target surface inside a commercial Cs ion sputtering source and to avoid edge effects, the samples were mechanically scanned and the signals were recorded only during sputtering at the centre of the sputtered area. The sputtered negative ions were mass analysed by the injection magnet of the Tandetron. Hydrogen and deuterium profiles were measured with the Faraday cup between the injection magnet and the accelerator, while the tritium was counted after the accelerator with semiconductor detectors. Depth profiles have been measured for carbon samples which had been exposed to the plasma at the first wall of the Garching fusion experiment ASDEX-Upgrade and from the European fusion experiment JET, Culham, UK

  13. Thorium utilization in heavy water moderated Accelerator Driven Systems

    International Nuclear Information System (INIS)

    Bajpai, Anil; Degweker, S.B.; Ghosh, Biplab

    2011-01-01

    Research on Accelerator Driven Systems (ADSs) is being carried out around the world primarily with the objective of waste transmutation. Presently, the volume of waste in India is small and therefore there is little incentive to develop ADS based waste transmutation technology immediately. With limited indigenous U availability and the presence of large Th deposits in the country, there is a clear incentive to develop Th related technologies. India also has vast experience in design, construction and operation of heavy water moderated reactors. Heavy water moderated reactors employing solid Th fuels can be self sustaining, but the discharge burnups are too low to be economical. A possible way to improve the performance such reactors is to use an external neutron source as is done in ADS. This paper discusses our studies on Th utilization in heavy water moderated ADSs. The study is carried out at the lattice level. The time averaged k-infinity of the Th bundle from zero burnup up to the discharge burnup is taken to be the same as the core (ensemble) averaged k-infinity. For the purpose of the analysis we have chosen standard PHWR and AHWR assemblies. Variation of the pitch and coolant (H 2 O/D 2 O) are studied. Both, the once through cycle and the recycling option are studied. In the latter case the study is carried out for various enrichments (% 233 U in Th) of the recycled Th fuel bundles. The code DTF as modified for lattice and burnup calculations (BURNTRAN) was used for carrying out the study. The once through cycle represents the most attractive ADS concept (Th burner ADS) possible for Th utilization. It avoids reprocessing of Th spent fuel and in the ideal situation the use of any fissile material either initially or for sustaining itself. The gain in this system is however rather low requiring a high power accelerator and a substantial fraction of the power generated to be fed back to the accelerator. The self sustaining Th-U cycle in a heavy moderated ADS

  14. Applications of accelerator mass spectrometry: advances and innovation

    International Nuclear Information System (INIS)

    Fifield, L.K.

    2004-01-01

    Emerging trends in the applications of accelerator mass spectrometry (AMS) are identified and illustrated with specific examples. Areas of application covered include rapid landscape evolution, calibration of the radiocarbon time scale, compound-specific radiocarbon studies, tracing of nuclear discharges, and searches for extraterrestrial isotopes

  15. 14 C dating by using mass spectrometry with particle accelerator

    International Nuclear Information System (INIS)

    Santos, G.M.; Gomes, P.R.S.; Yokoyama, Y.; Tada, M.L. di; Cresswell, R.G.; Fifield, L.K.

    1999-01-01

    The different aspects concerning the 14 C dating are described, including the cosmogenic origin of 14 C, its production and absorption by matter, the procedures to be followed for the age determination and the associated errors, particularly by the Accelerator Mass Spectrometry (AMS) technique, and the different steps of the sample preparation process. (author)

  16. Neutrino mass and mixing, and non-accelerator experiments

    International Nuclear Information System (INIS)

    Robertson, R.G.H.

    1992-01-01

    We review the current status of experimental knowledge about neutrinos derived from kinematic mass measurements, neutrino oscillation searches at reactors and accelerators, solar neutrinos, atmospheric neutrinos, and single and double beta decay. The solar neutrino results yield fairly strong and consistent indication that neutrino oscillations are occurring. Other evidence for new physics is less consistent and convincing

  17. Injection system of the minicyclotron accelerator mass spectrometer

    International Nuclear Information System (INIS)

    Liu Yonghao; Li Deming; Chen Maobai; Lu Xiangshun

    1999-01-01

    The existing injection system of the SMCAMS (super-sensitive mini-cyclotron accelerator mass spectrometer) is described together with the discussion of its disadvantages exposed after having been operating for five years, which provides a basis for consideration of improvements to the injection system. An optimized injection system with an analytical magnet added prior to the minicyclotron has been proposed and calculated

  18. Surface Mass Balance Contributions to Acceleration of Antarctic Ice Mass Loss during 2003- 2013

    Science.gov (United States)

    Seo, K. W.; Wilson, C. R.; Scambos, T. A.; Kim, B. M.; Waliser, D. E.; Tian, B.; Kim, B.; Eom, J.

    2015-12-01

    Recent observations from satellite gravimetry (the GRACE mission) suggest an acceleration of ice mass loss from the Antarctic Ice Sheet (AIS). The contribution of surface mass balance changes (due to variable precipitation) is compared with GRACE-derived mass loss acceleration by assessing the estimated contribution of snow mass from meteorological reanalysis data. We find that over much of the continent, the acceleration can be explained by precipitation anomalies. However, on the Antarctic Peninsula and other parts of West Antarctica mass changes are not explained by precipitation and are likely associated with ice discharge rate increases. The total apparent GRACE acceleration over all of the AIS between 2003 and 2013 is -13.6±7.2 GTon/yr2. Of this total, we find that the surface mass balance component is -8.2±2.0 GTon/yr2. However, the GRACE estimate appears to contain errors arising from the atmospheric pressure fields used to remove air mass effects. The estimated acceleration error from this effect is about 9.8±5.8 GTon/yr2. Correcting for this yields an ice discharge acceleration of -15.1±6.5 GTon/yr2.

  19. Computer automation of an accelerator mass spectrometry system

    International Nuclear Information System (INIS)

    Gressett, J.D.; Maxson, D.L.; Matteson, S.; McDaniel, F.D.; Duggan, J.L.; Mackey, H.J.; North Texas State Univ., Denton, TX; Anthony, J.M.

    1989-01-01

    The determination of trace impurities in electronic materials using accelerator mass spectrometry (AMS) requires efficient automation of the beam transport and mass discrimination hardware. The ability to choose between a variety of charge states, isotopes and injected molecules is necessary to provide survey capabilities similar to that available on conventional mass spectrometers. This paper will discuss automation hardware and software for flexible, high-sensitivity trace analysis of electronic materials, e.g. Si, GaAs and HgCdTe. Details regarding settling times will be presented, along with proof-of-principle experimental data. Potential and present applications will also be discussed. (orig.)

  20. Determination of {sup 135}Cs by accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, C.M.; Charles, C.R.J. [Andre. E. Lalonde AMS Laboratory, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Department of Earth Sciences, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Zhao, X.-L.; Kieser, W.E. [Andre. E. Lalonde AMS Laboratory, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Department of Physics, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Cornett, R.J. [Andre. E. Lalonde AMS Laboratory, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Department of Earth Sciences, University of Ottawa, 150 Louis Pasteur, Ottawa, ON K1N 6N5 (Canada); Litherland, A.E. [IsoTrace Laboratory, University of Toronto, 60 St. George St., Toronto, ON M5S 1A7 (Canada)

    2015-10-15

    The ratio of anthropogenic {sup 135}Cs and {sup 137}Cs isotopes is characteristic of a uranium fission source. This research evaluates the technique of isotope dilution (yield tracing) for the purpose of quantifying {sup 135}Cs by accelerator mass spectrometry with on-line isobar separation. Interferences from Ba, Zn{sub 2}, and isotopes of equal mass to charge ratios were successfully suppressed. However, some sample crosstalk from source contamination remains. The transmission and di-fluoride ionization efficiencies of Cs isotopes were found to be 8 × 10{sup −3} and 1.7 × 10{sup −7} respectively. This quantification of {sup 135}Cs using yield tracing by accelerator mass spectrometry shows promise for future environmental sample analysis once the issues of sample crosstalk and low efficiency can be resolved.

  1. Accelerator mass spectrometry for measurement of long-lived radioisotopes.

    Science.gov (United States)

    Elmore, D; Phillips, F M

    1987-05-01

    Particle accelerators, such as those built for research in nuclear physics, can also be used together with magnetic and electrostatic mass analyzers to measure rare isotopes at very low abundance ratios. All molecular ions can be eliminated when accelerated to energies of millions of electron volts. Some atomic isobars can be eliminated with the use of negative ions; others can be separated at high energies by measuring their rate of energy loss in a detector. The long-lived radioisotopes (10)Be, (14)C,(26)A1, 36Cl, and (129)1 can now be measured in small natural samples having isotopic abundances in the range 10(-12) to 10(- 5) and as few as 10(5) atoms. In the past few years, research applications of accelerator mass spectrometry have been concentrated in the earth sciences (climatology, cosmochemistry, environmental chemistry, geochronology, glaciology, hydrology, igneous petrogenesis, minerals exploration, sedimentology, and volcanology), in anthropology and archeology (radiocarbon dating), and in physics (searches for exotic particles and measurement of halflives). In addition, accelerator mass spectrometry may become an important tool for the materials and biological sciences.

  2. Accelerator mass spectrometry of 41Ca with a positive-ion source and the UNILAC accelerator

    International Nuclear Information System (INIS)

    Steinhof, A.; Henning, W.; Mueller, M.; Roeckl, E.; Schuell, D.; Korschinek, G.; Nolte, E.; Paul, M.

    1987-06-01

    We have made first tests investigating the performance characteristics of the UNILAC accelerator system at GSI, in order to explore the sensitivity achievable in accelerator mass spectrometry (AMS) of 41 Ca with high-current positive-ion sources. Positively charged Ca 3+ ions of up to about 100 micro-amperes electrical current were injected from a penning-sputter source and, after further stripping to Ca 9+ , accelerated to 14.3 MeV/nucleon. The combination of velocity-focussing accelerator and magnetic ion-beam transport system completely eliminated background from the other calcium isotopes. Full-stripping and detection of 41 Ca 20+ ions with a magnetic spectrograph provides separation from isobaric 41 K and, at present, a level of sensitivity of 41 Ca/Ca ≅ 2x10 -15 . Future improvements and implications for dating of Pleistoscene samples will be discussed. (orig.)

  3. Report of the consultants' meeting on accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    Accelerator Mass Spectrometry (AMS) has developed into a major analytical tool for the measurement of ultra-low-level long-lived radionuclides. Its use within the IAEA is recommended by the consultants in this meeting. The IAEA programs in which the technology would be useful and beneficial are: safeguards, physical and chemical sciences, human health, food and agriculture, radioactive waste management, radiation safety, industry and earth sciences.

  4. Report of the consultants' meeting on accelerator mass spectrometry

    International Nuclear Information System (INIS)

    1995-01-01

    Accelerator Mass Spectrometry (AMS) has developed into a major analytical tool for the measurement of ultra-low-level long-lived radionuclides. Its use within the IAEA is recommended by the consultants in this meeting. The IAEA programs in which the technology would be useful and beneficial are: safeguards, physical and chemical sciences, human health, food and agriculture, radioactive waste management, radiation safety, industry and earth sciences

  5. Mass, charge, and energy separation by selective acceleration with a traveling potential hill

    Science.gov (United States)

    Tung, L. Schwager; Barr, W. L.; Lowder, R. S.; Post, R. F.

    1996-10-01

    A traveling electric potential hill has been used to generate an ion beam with an energy distribution that is mass dependent from a monoenergetic ion beam of mixed masses. This effect can be utilized as a novel method for mass separation applied to identification or enrichment of ions (e.g., of elements, isotopes, or molecules). This theory for mass-selective acceleration is presented here and is shown to be confirmed by experiment and by a time-dependent particle-in-cell computer simulation. Results show that monoenergetic ions with the particular mass of choice are accelerated by controlling the hill potential and the hill velocity. The hill velocity is typically 20%-30% faster than the ions to be accelerated. The ability of the hill to pickup a particular mass uses the fact that small kinetic energy differences in the lab frame appear much larger in the moving hill frame. Ions will gain energy from the approaching hill if their relative energy in the moving hill frame is less than the peak potential of the hill. The final energy of these accelerated ions can be several times the source energy, which facilitates energy filtering for mass purification or identification. If the hill potential is chosen to accelerate multiple masses, the heaviest mass will have the greatest final energy. Hence, choosing the appropriate hill potential and collector retarding voltage will isolate ions with the lightest, heaviest, or intermediate mass. In the experimental device, called a Solitron, purified 20Ne and 22Ne are extracted from a ribbon beam of neon that is originally composed of 20Ne:22Ne in the natural ratio of 91:9. The isotopic content of the processed beam is determined by measuring the energy distribution of the detected current. These results agree with the theory. In addition to mass selectivity, our theory can also be applied to the filtration of an ion beam according to charge state or energy. Because of this variety of properties, the Solitron is envisioned to

  6. 36Chlorine accelerator mass spectrometry programme at BARC-TIFR pelletron accelerator. RSP-12

    International Nuclear Information System (INIS)

    Surendran, P.; Shrivastava, A.; Gupta, A.K.; Nair, J.P.; Yadav, M.L.; Gore, J.A.; Sparrow, H.; Bhagwat, P.V.; Kailas, S.; Kale, R.M.; Hemalatha, M.

    2007-01-01

    Accelerator mass spectrometry (AMS) is an ultra sensitive means of counting individual atoms having sufficiently long half life and available in small amount. The 14 UD Pelletron Accelerator is an ideal machine to carry out AMS studies with heavy isotopes like 36 Cl and 129 I. Cosmogenic radio isotope 36 Cl is widely being detected using AMS as it has got applications in ground water research, radioactive waste management, atmospheric 36 Cl transport mechanism studies of Arctic Alpine ice core etc. As a part of the ongoing AMS programme at 14UD Pelletron Accelerator Facility, Mumbai, a segmented gas detector developed for identification of 36 Cl was tested for performance. Recently a beam chopper required for this measurement has been developed. 36 Cl measurements carried out to detect and measure the ratio of 36 Cl to 35 Cl in an irradiated sample and dated sample are reported in this paper

  7. Effect of electrode mass ratio on aging of activated carbon based supercapacitors utilizing organic electrolytes

    Science.gov (United States)

    Cericola, D.; Kötz, R.; Wokaun, A.

    2011-03-01

    The accelerated degradation of carbon based supercapacitors utilizing 1 M Et4NBF4 in acetonitrile and in propylene carbonate as electrolyte is investigated for a constant cell voltage of 3.5 V as a function of the positive over total electrode mass ratio. The degradation rate of the supercapacitor using acetonitrile as a solvent can be decreased by increasing the mass of the positive electrode. With a mass ratio (positive electrode mass/total electrode mass) of 0.65 the degradation rate is minimum. For the capacitor utilizing propylene carbonate as a solvent a similar effect was observed. The degradation rate was smallest for a mass ratio above 0.5.

  8. Accelerator mass spectrometry programme at BARC-TIFR pelletron accelerator. PD-1-2

    International Nuclear Information System (INIS)

    Bhagwat, P.V.

    2007-01-01

    Accelerator mass spectrometry (AMS) is an ultra sensitive means of counting individual atoms having sufficiently long half-life and available in small amount. The 14 UD Pelletron Accelerator is an ideal machine to carry out AMS studies with heavy isotopes like 36 Cl and 129 I. Cosmogenic radioisotope 36 Cl is widely being detected using AMS as it has got applications in ground water research, radioactive waste management, atmospheric 36 Cl transport mechanism studies of Arctic Alpine ice core etc . The AMS programme at the 14 UD Mumbai Pelletron Accelerator has taken off with the installation of the state of the art Terminal Potential Stabilizer setup and operation of the accelerator in Generating Volt Meter (GVM) mode. Feasibility studies have been carried out for detection/identification of 14 C from a charcoal sample and 3 He in natural Helium. As the primary interest of AMS programme at Mumbai Pelletron Accelerator is related to the cosmogenic nuclei, 36 Cl and 129 I, a segmented gas detector developed for identification of 36 Cl was tested for performance. Recently a beam chopper required for this measurement has also been developed

  9. Present and future prospects of accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Kutschera, W

    1988-05-20

    Accelerator mass spectrometry (AMS) has become a powerful technique for measuring extremely low abundances (10/sup -10/ to 10/sup -15/ relative to stable isotopes) of long-lived radioisotopes with half-lives in the range from 10/sup 2/ to 10/sup 8/ years. With a few exceptions, tandem accelerators turned out to be the most useful instruments for AMS measurements. Both natural (mostly cosmogenic) and manmade (anthropogenic) radioisotopes are studied with this technique. In some cases very low concentrations of stable isotopes are also measured. Applications of AMS cover a large variety of fields including anthropology, archaeology, oceanography, hydrology, climatology, volcanology, mineral exploration, cosmochemistry, meteoritics, glaciology, sedimentary processes, geochronology, environmental physics, astrophysics, nuclear and particle physics. Present and future prospects of AMS will be discussed as an interplay between the continuous development of new techniques and the investigation of problems in the above mentioned field. Depending on the specific problem to be investigated, different aspects of an AMS system are of importance. Typical factors to be considered are energy range and type of accelerator, and the possibilities of dedicated versus partial use of new or existing accelerators.

  10. Present and future prospects of accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Kutschera, W.

    1987-04-01

    Accelerator Mass Spectrometry (AMS) has become a powerful technique for measuring extremely low abundances (10 -10 to 10 -15 relative to stable isotopes) of long-lived radioisotopes with half-lives in the range from 10 2 to 10 8 years. With a few exceptions, tandem accelerators turned out to be the most useful instruments for AMS measurements. Both natural (mostly cosmogenic) and man-made (anthropogenic) radioisotopes are studied with this technique. In some cases very low concentrations of stable isotope are also measured. Applications of AMS cover a large variety of fields including anthropology, archaeology, oceanography, hydrology, climatology, volcanology, minerals exploration, cosmochemistry, meteoritics, glaciology, sedimentary processes, geochronology, environmental physics, astrophysics, nuclear and particle physics. Present and future prospects of AMS are discussed as an interplay between the continuous development of new techniques and the investigation of problems in the above mentioned fields. Typical factors to be considered are energy range and type of accelerator, and the possibilities of dedicated versus partial use of new or existing accelerators

  11. Ultra-sensitive detection of plutonium by accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Fifield, L.K.; Cresswell, R.G.; Ophel, T.R.; Ditada, M. [Australian National Univ., Canberra, ACT (Australia). Dept. of Nuclear Physics; Day, J.P.; Clacher, A. [Manchester Univ. (United Kingdom). Dept. of Chemistry; Priest, N.D. [AEA Technology, Harwell (United Kingdom)

    1996-12-31

    On the bases of the measurements performed to date, a sensitivity of 10{sup 6} atoms is achievable with accelerator mass spectroscopy (AMS) for each of the plutonium isotopes. Not only does this open the way to the sort of study outlined, but it also makes possible other novel applications, of which two examples are given: (i)the ration of {sup 240}Pu to {sup 239}Pu as a sensitive indicator of the source of the plutonium; (ii) the biochemistry of plutonium in humans. The ultra-sensitive atom counting capability of AMS will make it possible to use the very long-lived {sup 244}Pu (8x10{sup 7}a) in human volunteer studies without any significant increase in radiation body burden. This paper will describe the AMS technique as applied to plutonium using the ANU`s 14UD accelerator, will present the results obtained to date, and will discuss the prospects for the future.

  12. Accelerator mass analyses of meteorites - carbon-14 terrestrial ages

    International Nuclear Information System (INIS)

    Miura, Y.; Rucklidge, J.; Beukens, R.; Fireman, E.

    1988-01-01

    Carbon-14 terrestrial ages of ten Antarctic meteorites have been measured by the IsoTrace accelerator mass spectrometry (AMS). The 14 C terrestrial age of 1 gram sample was determined from 14 C concentrations collected at melt and re-melt temperatures, compared with the 14 C concentration of the known Bruderheim chondrite. Yamato-790448 (LL3) chondrite was found to be the oldest terrestrial age of 3x10 4 years in the nine Yamato chondrites, whereas Yamato-791630 (L4) chondrite is considered to be the youngest chondrites less than thousand years. Allan Hills chondrite of ALH-77231 (L6) shows older terrestrial age than the nine Yamato chondrites. New accelerator data of the terrestrial age show higher accuracy with smaller sample than the previous counting method. (author)

  13. Ultra-sensitive detection of plutonium by accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Fifield, L K; Cresswell, R G; Ophel, T R; Ditada, M [Australian National Univ., Canberra, ACT (Australia). Dept. of Nuclear Physics; Day, J P; Clacher, A [Manchester Univ. (United Kingdom). Dept. of Chemistry; Priest, N D [AEA Technology, Harwell (United Kingdom)

    1997-12-31

    On the bases of the measurements performed to date, a sensitivity of 10{sup 6} atoms is achievable with accelerator mass spectroscopy (AMS) for each of the plutonium isotopes. Not only does this open the way to the sort of study outlined, but it also makes possible other novel applications, of which two examples are given: (i)the ration of {sup 240}Pu to {sup 239}Pu as a sensitive indicator of the source of the plutonium; (ii) the biochemistry of plutonium in humans. The ultra-sensitive atom counting capability of AMS will make it possible to use the very long-lived {sup 244}Pu (8x10{sup 7}a) in human volunteer studies without any significant increase in radiation body burden. This paper will describe the AMS technique as applied to plutonium using the ANU`s 14UD accelerator, will present the results obtained to date, and will discuss the prospects for the future.

  14. Accelerator mass spectrometry - Indian scenario. PD-1-1

    International Nuclear Information System (INIS)

    Kailas, S.

    2007-01-01

    Accelerator based ultra sensitive Mass Spectrometry (AMS) programmes are being vigorously pursued world over for the past three decades. There are more than 50 accelerator facilities devoted to this multidisciplinary activity. Realizing the importance of this programme, the work related to AMS has commenced at three major accelerator facilities in India: Institute of Physics, Bhubaneswar; Interuniversity Accelerator Centre, Delhi; BARC - TIFR Pelletron accelerator facility, Mumbai. At Bhubaneswar, facilities have been set up to carry our high precision 14 C based AMS programmes using the 3 MV Pelletron. A magnetic bouncer, an electrostatic analyzer and a chemistry lab for making samples in graphite form are some of the important features of this AMS facility. A number of users have already got their samples analysed using this AMS facility. The AMS programme has used upto 20 % of beam time available from the 3 MV Pelletron at Bhubaneswar. At Delhi efforts are underway and initial success has been achieved for carrying out 10 Be based AMS programme. Novel method based on simultaneously injecting oxide of Be - ( 9 Be and 17 O) and ( 10 Be and 16 O) has been tried to obtain the ratio of 9 Be / 10 Be. A velocity filter is also available for this programme. Both at Bhubaneswar and Delhi, provision exists in the form of a multi cathode target wheel for carrying out measurements for a number of samples. At Mumbai the emphasis has been in precision measurement of 36 Cl in samples. Segmented anode detector has been developed for the separation of interfering 36 S and 36 Cl isobars

  15. Radiocarbon accelerator mass spectrometry (AMS) sample preparation laboratory in Brazil

    International Nuclear Information System (INIS)

    Macario, Kita D.; Gomes, Paulo R. S.; Anjos, Roberto M. dos; Linares, Roberto; Queiroz, Eduardo; Oliveira, Fabiana M. de; Cardozo, Laio; Carvalho, Carla R.A.

    2011-01-01

    Full text: For decades Accelerator Mass Spectrometry has been widely used for radiocarbon measurements all over the world with application in several fields of science from archaeology to geosciences. This technique provides ultrasensitive analysis of reduced size samples or even specific compounds since sample atoms are accelerated to high energies and measured using nuclear particle detectors. Sample preparation is extremely important for accurate radiocarbon measurement and includes chemical pre-treatment to remove all possible contaminants. For beam extraction in the accelerator ion source, samples are usually converted to graphite. In this work we report a new radiocarbon sample preparation facility installed at the Physics Institute of Universidade Federal Fluminense (UFF), in Brazil. At the Nuclear Chronology Laboratory (LACRON) samples are chemically treated and converted to carbon dioxide by hydrolysis or combustion. A stainless steel based vacuum line was constructed for carbon dioxide separation and graphitization is performed in sealed quartz tubes in a muffle oven. Successful graphite production is important to provide stable beam currents and to minimize isotopic fractionation. Performance tests for graphite production are currently under way and isotopic analysis will soon be possible with the acquisition of a Single Stage AMS System by our group. The Single Stage Accelerator produced by National Electrostatic Corporation is a 250 kV air insulated accelerator especially constructed to measure the amount of 14 C in small modern graphite samples to a precision of 0.3 % or better. With the installation of such equipment in the first half of 2012, UFF will be ready to perform the 14C -AMS technique. (author)

  16. Utilization of low-energy electron accelerators in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Cheol [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2003-02-01

    There are more than 20 electron accelerators in Korea. Most of those are installed in factories for heat-resistant cables, heat-shrinkable cables, radial tires, foams, tube/ films, curing, etc. Four low-energy electron accelerators are in operation for research purposes such as polymer modification, purification of flue gas, waste water treatment, modification of semiconductor characteristics, etc. (author)

  17. Utilization of low-energy electron accelerators in Korea

    International Nuclear Information System (INIS)

    Lee, Byung Cheol

    2003-01-01

    There are more than 20 electron accelerators in Korea. Most of those are installed in factories for heat-resistant cables, heat-shrinkable cables, radial tires, foams, tube/ films, curing, etc. Four low-energy electron accelerators are in operation for research purposes such as polymer modification, purification of flue gas, waste water treatment, modification of semiconductor characteristics, etc. (author)

  18. Utilization of electron beam accelerators for polymer processing

    International Nuclear Information System (INIS)

    Sarma, K.S.S.

    2013-01-01

    During the last decade, electron beam processing has been amply demonstrated to the Indian cable industry by BARC using 2 MeV/20 kW electron beam (EB) accelerator (ILU-6 EBA facility) located at BARC-BRIT complex, Vashi. The electron beam accelerator is a machine producing high energy electrons which are made to impinge on the materials for inducing physical, chemical and biological modifications. The process is carried out at room temperature and in ambient atmospheric conditions. Lately, quite a few numbers of accelerators have been installed by the private cable industry and carrying out cross-linking of cable insulations for high performance viz. high temperature stability, good flame retardancy, lesser solvent-swelling, thinner insulations etc. The indigenously made accelerators at EB centre, particularly the 3 MeV/30 kW accelerator will be of much help for Indian industry for polymer processing as the market is poised to grow by adapting the technology

  19. Accelerator mass spectrometry at Peking University: experiments and progress

    International Nuclear Information System (INIS)

    Chen Jiaer; Guo Zhiyu; Yan Shengqing; Li Renxing; Xiao Min; Li Kun; Liu Hongtao; Liu Kexin; Wang Jianjun; Li Bin; Lu Xiangyang; Yuan Sixun; Chen Tiemei; Gao Shijun; Zheng Shuhui; Chen Chengye; Liu Yan

    1997-01-01

    The Peking University Accelerator Mass Spectrometer (PKUAMS) has been put into routine operation. 14 C measurements of archaeological samples with fast cycling injection have shown good results. The new multi-target high-intensity sputtering ion source has been tested and 10 Be measurements were carried out with a new detector in which both the stopping of the intense flux of 10 B ions and the identification of 10 Be ions are performed. 26 Al samples were also measured. While various applications show good prospects for PKUAMS, further upgrade is desirable

  20. Application of accelerator mass spectrometry in aluminum metabolism studies

    International Nuclear Information System (INIS)

    Meirav, O.; Vetterli, D.; Johnson, R.R.; Sutton, R.A.L.; Walker, V.R.; Halabe, A.; Fink, D.; Middleton, R.; Klein, J.

    1990-06-01

    The recent recognition that aluminum causes toxicity in uremic patients and may be associated with Alzheimer's disease has stimulated many studies of its biochemical effects. However, such studies were hampered by the lack of a suitable tracer. In a novel experiment, we have applied the new technique of accelerator mass spectrometry to investigate aluminum kinetics in rats, using as a marker the long-lived isotope 26 Al. We present the first aluminum kinetic model for a biological system. The results clearly demonstrate the advantage this technique holds for isotope tracer studies in animals as well as humans. (Author) (24 refs., 3 figs.)

  1. Application of accelerator mass spectrometry in aluminum metabolism studies

    Energy Technology Data Exchange (ETDEWEB)

    Meirav, O; Vetterli, D; Johnson, R R [British Columbia Univ., Vancouver, BC (Canada). Dept. of Physics; Sutton, R A.L.; Walker, V R; Halabe, A [British Columbia U.iv., Vancouver, BC (Canada). Dept. of Medicine; Fink, D; Middleton, R; Klein, J [Pennsylvania Univ., Philadelphia, PA (United States). Dept. of Physics

    1990-06-01

    The recent recognition that aluminum causes toxicity in uremic patients and may be associated with Alzheimer`s disease has stimulated many studies of its biochemical effects. However, such studies were hampered by the lack of a suitable tracer. In a novel experiment, we have applied the new technique of accelerator mass spectrometry to investigate aluminum kinetics in rats, using as a marker the long-lived isotope {sup 26}Al. We present the first aluminum kinetic model for a biological system. The results clearly demonstrate the advantage this technique holds for isotope tracer studies in animals as well as humans. (Author) (24 refs., 3 figs.).

  2. Accelerator mass spectrometry with a coupled tandem-linac system

    International Nuclear Information System (INIS)

    Kutschera, W.

    1984-01-01

    A coupled system provides higher energies, which allows one to extend AMS to hitherto untouched mass regions. Another important argument is that the complexity, although bothersome for the operation, increases the selectivity of detecting a particular isotope. The higher-energy argument holds for any heavy-ion accelerator which is capable of delivering higher energy than a tandem. The present use of tandem-linac combinations for AMS, rather than cyclotrons, linacs or combinations of these machines, has mainly to do with the fact that this technique was almost exclusively developed around tandem accelerators. Therefore the tandem-linac combination is a natural extension to higher energies. The use of negative ions has some particular advantages in suppressing background from unwanted elements that do not form stable negative ions (e.g., N, Mg, Ar). On the other hand, this limits the detection of isotopes to elements which do form negative ions. For particular problems it may therefore be advantageous to use a positive-ion machine. What really matters most for choosing one or the other machine is to what extent the entire accelerator system can be operated in a truly quantiative way from the ion source to the detection system. 20 references, 4 figures

  3. Accelerator mass spectrometry with the Grenoble and Orsay cyclotrons

    International Nuclear Information System (INIS)

    Raisbeck, G.M.; Yiou, F.

    1981-01-01

    Three and one half years ago, at the Rochester meeting, we presented our first accelerator mass spectrometry measurements of 10 Be using the external ion source of the Grenoble cyclotron. Since that time the technique has been used to measure 10 Be in more than 100 geophysical samples. We have also used the ALICE accelerator facility (linear accelerator plus cyclotron) at Orsay to detect 26 Al (half-life 730,000 years) and 41 Ca (100,000 years). While the latter measurements have so far been carried out only with enriched samples, they did demonstrate the feasibility of eliminating interference from lower atomic number isobars by analyzing fully stripped ions of the species being sought. We describe here the present experimental status of these two techniques, following closely two papers presented recently at another conference. We would like to stress that these techniques have not been developed arbitrarily, or as goals in themselves, but rather with certain applications in mind. It is therefore perhaps useful to first briefly outline these applications, which can be divided into three areas

  4. Use of Tritium Accelerator Mass Spectrometry for Tree Ring Analysis

    Science.gov (United States)

    LOVE, ADAM H.; HUNT, JAMES R.; ROBERTS, MARK L.; SOUTHON, JOHN R.; CHIARAPPA - ZUCCA, MARINA L.; DINGLEY, KAREN H.

    2010-01-01

    Public concerns over the health effects associated with low-level and long-term exposure to tritium released from industrial point sources have generated the demand for better methods to evaluate historical tritium exposure levels for these communities. The cellulose of trees accurately reflects the tritium concentration in the source water and may contain the only historical record of tritium exposure. The tritium activity in the annual rings of a tree was measured using accelerator mass spectrometry to reconstruct historical annual averages of tritium exposure. Milligram-sized samples of the annual tree rings from a Tamarix located at the Nevada Test Site are used for validation of this methodology. The salt cedar was chosen since it had a single source of tritiated water that was well-characterized as it varied over time. The decay-corrected tritium activity of the water in which the salt cedar grew closely agrees with the organically bound tritium activity in its annual rings. This demonstrates that the milligram-sized samples used in tritium accelerator mass spectrometry are suited for reconstructing anthropogenic tritium levels in the environment. PMID:12144257

  5. Accelerator mass spectrometry at IFIN-HH in Bucharest

    International Nuclear Information System (INIS)

    Stan-Sion, C.; Catana, D.; Plostinaru, D.; Radulescu, M.; Enachescu, M.

    1999-01-01

    An AMS (Accelerator Mass Spectrometry) facility was constructed at the FN - 8 MV Tandem Accelerator of the National Institute for Physics and Nuclear Engineering in Bucharest. It represents the first experimental setup of this type in the large geographical area of Eastern Europe. The main components of the facility are: the ion injector deck, the AMS beam line and the detector systems. The injector deck is polarised at 50 kV and contains the high current sputtering ion source (spherical ionizer) followed, for beam transport, by electrostatic devices (single lenses, steerers, quadrupole lenses), a double focussing, 90 angle analysing magnet (Danfysik), a pre-acceleration tube (NEC) and several diagnose and defining elements. The AMS samples are placed in an eight stack magazine attached to the ion source. On the exit side of the Tandem Accelerator tank, a velocity filter and the particle detection system are mounted. The beam line, on the high energy side, is optically achromatic and contains two 90 angle analysing magnets of 150 MEP. For particle detection a Bragg-curve Spectroscopy Detector (ionisation chamber) is used and a multi-anode gas detector with TOF discrimination is under construction. The research programme at this new facility is focused on using 26 Al for medical applications. In future it will be use for 129 I - AMS measurements as a nuclear safeguard. This long lived isotope will be used to monitor and investigate the transport of 129 I in vicinity of three nuclear power plants in Eastern Europe: Kozloduy (Bulgaria), Cernavoda (Romania) and Chernobyl (Ukraine). Measurements will concern soil, precipitation and air samples. Water samples will be collected along the flow of rivers Danube and Dnieper, from the Danube Delta and from coastal areas of the Black Sea. (authors)

  6. Method and apparatus for accelerating a solid mass

    International Nuclear Information System (INIS)

    Tidman, D.A.; Goldstein, Y.A.

    1984-01-01

    An axi-symmetrical projectile, having a mass ranging from fractions of a gram to kilograms, is accelerated to velocities in the range of 10 5 to 10 7 centimeters per second by a propelling force produced by a plasma resulting from electric discharge. The discharge is imploded against the projectile surface so lines of the magnetic fields are approximately azimuthal around the projectile axis. The projectile is tapered so it experiences a net, stable axial accelerating force along the accelerator axis by the combined action of the magnetic field producing radially directed momentum and pressure on the plasma, the interaction of the magnetic field and ions induced by the plasma on the surface, as well as material the plasma ablates from the surface. The plasma discharge is initiated either in low density background gas between anode and cathode of a discharge module, or along an insulator surface between the electrodes in low density background gas. Alternatively, in either of these situations the discharge can be initiated in a gas which is produced by ablation of the projectile surface. In an alternative situation, the projectile acts as a switch for triggering discharges. Eddy current heating of the projectile is minimized by shaping the discharge current pulse so the plasma has a relatively weak magnetic field when it arrives at the surface, or by making the projectile electrically non-conducting. To provide a long acceleration path, a series of modules is aligned. In one embodiment, the projectile position, as it advances between modules, is sensed and discharges are switched on sequentially in the modules

  7. 36Cl accelerator mass spectrometry with a bespoke instrument

    International Nuclear Information System (INIS)

    Wilcken, K.M.; Freeman, S.P.H.T.; Schnabel, C.; Binnie, S.A.; Xu, S.; Phillips, R.J.

    2013-01-01

    Cosmogenic 36 Cl analysis by accelerator mass spectrometry (AMS) is a valuable environmental and geological sciences research tool. Overcoming the stable nuclide 36 S isobar interfering with measurement is challenging, however. Traditionally this has required large accelerators, but following recent technical advances it is now possible with ∼30 MeV ion energies. Consequently 5 MV or even smaller modern bespoke spectrometers are now 36 Cl-capable, increasing accessibility and promoting wider and more varied 36 Cl use. However, the technical ability to identify 36 Cl ions is quite distinct from demonstrated high-performance AMS. Such is the theme of this paper. We present a systematic analysis of the accurate measurement of sample radioisotope relative to the stable chlorine, the normalisation of the measured ratio and correction for remaining 36 S interference, all combined with the use of stable-isotope dilution to determine sample Cl concentration to begin with. We conclude by showing that repeated analyses support our claims for routine 3% 36 Cl-AMS data. Accordingly, the modest SUERC spectrometer well competes with the performance of larger longer-established instruments, and the results may be quite generic for modern bespoke instruments.

  8. Application of accelerator mass spectrometry in nuclear science

    International Nuclear Information System (INIS)

    Wang Xiaobo; Hu Jinjun; Wang Huijuan; Guan Yongjing; Wang Wei

    2013-01-01

    Accelerator mass spectrometry (AMS) is a promising method to provide extreme sensitivity measurements of the production yields of long-lived radioisotopes, which cannot be detected by other methods. AMS technique plays an important role in the research of nuclear physics, as well as the application field of AMS covered nuclear science and technology, life science, earth science, environmental science, archaeology etc. The newest AMS field is that of actinide, particularly U and Pu, isotopic assay with expanding applications in nuclear safeguards and monitoring, and as a modern bomb-fallout tracer for atmospheric transport and surface sediment movement. This paper reviews the applications of AMS in the research of nuclear energy and nuclear security including the research of half life of radionuclides, cross section of nuclear reaction. (authors)

  9. Dating of some fossil Romanian bones by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Olariu, Agata; Skog, Goeran; Emilian Alexandrescu; Hellborg, Ragnar; Stenstroem, Krstina; Faarinen, Mikko; Persson, Per

    2002-01-01

    Some fossil bones from Romanian territories have been dated by accelerator mass spectrometry (AMS) using the pelletron system from Lund University. The preparation of samples has been the classical procedure to produce pure graphite from bones specimens, The Paleolithic site from Malu Rosu, near Giurgiu was thoroughly analyzed. Two human fossil skulls from Cioclovina and Baia de Fier of special archaeological importance have been estimated to be of around 30 000 years old, a conclusion with great implications for the history of ancient Romania. By this physical analysis, a long scientific dispute was settled. The two fossil human skulls are the only ones of this age from Romania. One could advance the hypothesis that the skulls belong to a certain type of a branch of Central European Cro-Magon, the classical western type, considering both the chronological and the anthropological features. They constitute eastern limit of the Cro-Magnon man type. (authors)

  10. The AMS [Accelerator Mass Spectrometer] program at LLNL

    International Nuclear Information System (INIS)

    Proctor, I.D.

    1988-09-01

    Livermore will have an operational Accelerator Mass Spectrometer (AMS) by mid-1989 as part of its new Multi-user Tandem Laboratory. The spectrometer was designed primarily for applications in archaeology and the geosciences and was co-funded by the University of California Regents. Radiological control for personnel protection, ion sources and injection systems, the tandem and all beam handling hardware are operated with a distributed processor computer control system. The Tandem is the former University of Washington injector FN which has been upgraded with Dowlish tubes, pelletron charging and SF 6 gas. Design goals for the AMS system, computer aided operation, automated measurement capability, initial results and some of our intended applications will be presented. 5 refs., 2 figs

  11. Utilization of pion production accelerators in biomedical applications

    International Nuclear Information System (INIS)

    Rosen, L.

    1979-01-01

    A discussion is presented of biomedical applications of pion-producing accelerators in a number of areas, but with emphasis on pion therapy for treatment of solid, non-metastasized malignancies. The problem of cancer management is described from the standpoint of the physicist, magnitude of the problem, and its social and economic impact. Barriers to successful treatment are identified, mainly with regard to radiation therapy. The properties and characteristics of π mesons, first postulated on purely theoretical grounds by H. Yukawa are described. It is shown how they can be used to treat human cancer and why they appear to have dramatic advantages over conventional forms of radiation by virtue of the fact that they permit localization of energy deposition, preferentially, in the tumor volume. The Clinton P. Anderson Meson Physics Facility (LAMPF), and its operating characteristics, are briefly described, with emphasis on the biomedical channel. The design of a relatively inexpensive accelerator specifically for pion therapy is described as is also the status of clinical trials using the existing Clinton P. Anderson Meson Physics Facility. The advantages of proton over electron accelerator for the production of high quality, high intensity negative pion beams suitable for radiation therapy of malignancies is also addressed. Other current, medically related applications of LAMPF technology are also discussed

  12. Accelerator mass spectrometry of Strontium-90 for homeland security, environmental monitoring, and human health

    Energy Technology Data Exchange (ETDEWEB)

    Tumey, S J; Brown, T A; Hamilton, T F; Hillegonds, D J

    2008-03-03

    Strontium-90 is one of the most hazardous materials managed by agencies charged with protecting the public from radiation. Traditional radiometric methods have been limited by low sample throughput and slow turnaround times. Mass spectrometry offers the advantage of shorter analysis times and the ability to measure samples immediately after processing, however conventional mass spectrometric techniques are susceptible to molecular isobaric interferences that limit their overall sensitivity. In contrast, accelerator mass spectrometry is insensitive to molecular interferences and we have therefore begun developing a method for determination of {sup 90}Sr by accelerator mass spectrometry. Despite a pervasive interference from {sup 90}Zr, our initial development has yielded an instrumental background of {approx} 10{sup 8} atoms (75 mBq) per sample. Further refinement of our system (e.g., redesign of our detector, use of alternative target materials) is expected to push the background below 10{sup 6} atoms, close to the theoretical limit for AMS. Once we have refined our system and developed suitable sample preparation protocols, we will utilize our capability in applications to homeland security, environmental monitoring, and human health.

  13. Feasibility study on the construction and utilization of charged particle accelerators

    International Nuclear Information System (INIS)

    Cho, S.W.; Chung, M.K.; Choe, B.H.; Lee, K.W.; In, S.Y.; Park, I.S.; Kang, S.S.

    1981-01-01

    This is a report on the thorough studies of feasible accelerator to be constructed in Korea from various aspects. By following the brief descriptions on the operational principles and applications of various types of particle accelerators, estimations of required budgeting for construction and operation of those accelerators are given in detail. From the forecasted availability of government investment to accelerator project and also from the expected great role of accelerators to be played for nuclear power developments, we draw three steps' development program of accelerator technology in Korea. The first step is mainly aimed to user development and accumulation of accelerator technology through the construction and utilization of 50-100MeV electron linear accelerator. The second step to be recommended is the construction of 20-30MeV proton linear accelerator which can be used as an injector for future proton synchrotron. The third step is construction and utilization of several GeV proton synchrotron. However, development of accelerator technology in advanced countries is so fast that above-mentioned second and third step may not be regarded to be definite plans

  14. Research on Utilizing a Multivariate Feedback Algorithm to Maintain Stable Operation of Variable Energy Electron Accelerators

    International Nuclear Information System (INIS)

    Van Ausdeln, L.A.; Cordes, G.A.; Haskell, K.J.; Jones, J.L.

    2002-01-01

    Measurements performed utilizing particle accelerators rely on the stability and reproducibility of the accelerator operation, most notably for beam flux (beam current) and beam energy. This can be vital when the measurements rely on previous calibrations performed to establish a standard on which to base the end result of the measurement. The authors have designed a monitoring and control virtual instrument (VI) based on National Instruments LabVIEW TM which calls external modeling code that is written in a standard programming language. The LabVIEWTM virtual instrument allows the user to monitor multiple accelerator parameters while permitting user control of the most important four of these parameters which determine machine operation. The external modeling code, the Advanced Data Validation and Verification System (ADVVS), incorporates as a kernel the Universal Process Model (UPM) software from Triant Technologies, Inc. The kernel executes the accelerator modeling function based on previously acquired history data of the relevant parameters for accelerator operation for conditions of interest. This history data is stored as a reference set prior to subsequent operation. During accelerator operation, 11 accelerator parameters are input to ADVVS from the LabVIEW TM virtual instrument. The ADVVS uses the reference files to predict the eleven parameter values that would normally be expected for optimal accelerator operation. The set of 11 model values is the nearest model state. This multivariate modeling approach presented two principal advantages: 1. The ADVVS allowed rapid detection of anomalous accelerator behavior variant from normal accelerator behavior recorded in the reference set of the kernel. 2. The ADVVS presented a methodology to incrementally tune the accelerator back to optimal operation, thus maintaining highly stable and reproducible operation. In the future, this methodology may also be utilized to tune the accelerator initially or move

  15. Accelerator mass spectrometry of the heaviest long-lived ...

    Indian Academy of Sciences (India)

    A 3-MV pelletron tandem accelerator is the heart of the Vienna environmental research accelerator (VERA). ... Vienna Environmental Research Accelerator, Institute for Isotopic Research and Nuclear Physics, University of Vienna, A-1090 Vienna, Austria; Russian Research Center, “Kurchatov Institute”, Institute of Nuclear ...

  16. Human folate metabolism using 14C-accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Arjomand, A; Bucholz, B A; Clifford, A J; Duecker, S R; Johnson, H; Schneider, P D; Zulim, R A.

    1999-01-01

    Folate is a water soluble vitamin required for optimal health, growth and development. It occurs naturally in various states of oxidation of the pteridine ring and with varying lengths to its glutamate chain. Folates function as one-carbon donors through methyl transferase catalyzed reactions. Low-folate diets, especially by those with suboptimal methyltransferase activity, are associated with increased risk of neural tube birth defects in children, hyperhomocysteinemic heart disease, and cancer in adults. Rapidly dividing (neoplastic) cells have a high folate need for DNA synthesis. Chemical analogs of folate (antifolates) that interfere with folate metabolism are used as therapeutic agents in cancer treatment. Although much is known about folate chemistry, metabolism of this vitamin in vivo in humans is not well understood. Since folate levels in blood and tissues are very low and methods to measure them are inadequate, the few previous studies that have examined folate metabolism used large doses of radiolabeled folic acid in patients with Hodgkins disease and cancer (Butterworth et al. 1969, Krumdieck et al. 1978). A subsequent protocol using deuterated folic acid was also insufficiently sensitive to trace a physiologic folate dose (Stites et al. 1997). Accelerator mass spectrometry (AMS) is an emerging bioanalytical tool that overcomes the limitations of traditional mass spectrometry and of decay counting of long lived radioisotopes (Vogel et al. 1995). AMS can detect attomolar concentrations of 14 C in milligram-sized samples enabling in vivo radiotracer studies in healthy humans. We used AMS to study the metabolism of a physiologic 80 nmol oral dose of 14 C-folic acid (1/6 US RDA) by measuring the 14 C-folate levels in serial plasma, urine and feces samples taken over a 150-day period after dosing a healthy adult volunteer

  17. Accelerator mass spectrometry of ultra-small samples with applications in the biosciences

    International Nuclear Information System (INIS)

    Salehpour, Mehran; Håkansson, Karl; Possnert, Göran

    2013-01-01

    An overview is presented covering the biological accelerator mass spectrometry activities at Uppsala University. The research utilizes the Uppsala University Tandem laboratory facilities, including a 5 MV Pelletron tandem accelerator and two stable isotope ratio mass spectrometers. In addition, a dedicated sample preparation laboratory for biological samples with natural activity is in use, as well as another laboratory specifically for 14 C-labeled samples. A variety of ongoing projects are described and presented. Examples are: (1) Ultra-small sample AMS. We routinely analyze samples with masses in the 5–10 μg C range. Data is presented regarding the sample preparation method, (2) bomb peak biological dating of ultra-small samples. A long term project is presented where purified and cell-specific DNA from various part of the human body including the heart and the brain are analyzed with the aim of extracting regeneration rate of the various human cells, (3) biological dating of various human biopsies, including atherosclerosis related plaques is presented. The average built up time of the surgically removed human carotid plaques have been measured and correlated to various data including the level of insulin in the human blood, and (4) In addition to standard microdosing type measurements using small pharmaceutical drugs, pre-clinical pharmacokinetic data from a macromolecular drug candidate are discussed.

  18. Accelerator mass spectrometry of ultra-small samples with applications in the biosciences

    Energy Technology Data Exchange (ETDEWEB)

    Salehpour, Mehran, E-mail: mehran.salehpour@physics.uu.se [Department of Physics and Astronomy, Ion Physics, PO Box 516, SE-751 20 Uppsala (Sweden); Hakansson, Karl; Possnert, Goeran [Department of Physics and Astronomy, Ion Physics, PO Box 516, SE-751 20 Uppsala (Sweden)

    2013-01-15

    An overview is presented covering the biological accelerator mass spectrometry activities at Uppsala University. The research utilizes the Uppsala University Tandem laboratory facilities, including a 5 MV Pelletron tandem accelerator and two stable isotope ratio mass spectrometers. In addition, a dedicated sample preparation laboratory for biological samples with natural activity is in use, as well as another laboratory specifically for {sup 14}C-labeled samples. A variety of ongoing projects are described and presented. Examples are: (1) Ultra-small sample AMS. We routinely analyze samples with masses in the 5-10 {mu}g C range. Data is presented regarding the sample preparation method, (2) bomb peak biological dating of ultra-small samples. A long term project is presented where purified and cell-specific DNA from various part of the human body including the heart and the brain are analyzed with the aim of extracting regeneration rate of the various human cells, (3) biological dating of various human biopsies, including atherosclerosis related plaques is presented. The average built up time of the surgically removed human carotid plaques have been measured and correlated to various data including the level of insulin in the human blood, and (4) In addition to standard microdosing type measurements using small pharmaceutical drugs, pre-clinical pharmacokinetic data from a macromolecular drug candidate are discussed.

  19. Accelerator mass spectrometry: ultrasensitive analysis of global science

    International Nuclear Information System (INIS)

    Tuniz, C.; Bird, J.B.; Fink, D.; Herzog, G.F.

    1998-01-01

    Accelerator mass spectrometry (AMS), an innovative analytical technique, measures rare atoms at unprecedented levels of sensitivity, revolutionizing the science of radiocarbon dating and accessing new environmental tracers and chronometers. AMS can study extraterrestrial materials, the earth sciences, the future of the global environment, and the history of mankind. The Shroud of Turin, meteorites from Mars, the crown of Charlemagne, and ancient air trapped in Antarctic ice indicate some of the samples on which AMS has been applied. This book has compiled the diverse set of scientific literature into a single volume, suitable as a text or resource on the major AMS-related outcomes, issues, and methods. It explains how scientists and researchers succeeded in counting Carbon-14 atoms at an extraordinary level, examines the impact of AMS on the branches of scientific technology and historical research, provides an understanding of the chronology and significance of past and present environmental changes, details the advances in AMS equipment, technology, and methods as well as the expansion of AMS research

  20. Improving tritium exposure reconstructions using accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Love, A.H.; Hunt, J.R.; Vogel, J.S.; Knezovich, J.P.

    2004-01-01

    Direct measurement of tritium atoms by accelerator mass spectrometry (AMS) enables rapid low-activity tritium measurements from milligram-sized samples and permits greater ease of sample collection, faster throughput, and increased spatial and/or temporal resolution. Because existing methodologies for quantifying tritium have some significant limitations, the development of tritium AMS has allowed improvements in reconstructing tritium exposure concentrations from environmental measurements and provides an important additional tool in assessing the temporal and spatial distribution of chronic exposure. Tritium exposure reconstructions using AMS were previously demonstrated for a tree growing on known levels of tritiated water and for trees exposed to atmospheric releases of tritiated water vapor. In these analyses, tritium levels were measured from milligram-sized samples with sample preparation times of a few days. Hundreds of samples were analyzed within a few months of sample collection and resulted in the reconstruction of spatial and temporal exposure from tritium releases. Although the current quantification limit of tritium AMS is not adequate to determine natural environmental variations in tritium concentrations, it is expected to be sufficient for studies assessing possible health effects from chronic environmental tritium exposure. (orig.)

  1. Applications of accelerator mass spectrometry for pharmacological and toxicological research.

    Science.gov (United States)

    Brown, Karen; Tompkins, Elaine M; White, Ian N H

    2006-01-01

    The technique of accelerator mass spectrometry (AMS), known for radiocarbon dating of archeological specimens, has revolutionized high-sensitivity isotope detection in pharmacology and toxicology by allowing the direct determination of the amount of isotope in a sample rather than measuring its decay. It can quantify many isotopes, including 26Al, 14C, 41Ca, and 3H with detection down to attomole (10(-18)) amounts. Pharmacokinetic data in humans have been achieved with ultra-low levels of radiolabel. One of the most exciting biomedical applications of AMS with 14C-labeled potential carcinogens is the detection of modified proteins or DNA in tissues. The relationship between low-level exposure and covalent binding of genotoxic chemicals has been compared in rodents and humans. Such compounds include heterocyclic amines, benzene, and tamoxifen. Other applications range from measuring the absorption of 26Al to monitoring 41Ca turnover in bone. In epoxy-embedded tissue sections, high-resolution imaging of 14C label in cells is possible. The uses of AMS are becoming more widespread with the availability of instrumentation dedicated to the analysis of biomedical samples. Copyright 2005 Wiley Periodicals, Inc.

  2. Ion source memory in {sup 36}Cl accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Pavetich, Stefan; Akhmadaliev, Shavkat; Merchel, Silke; Rugel, Georg [HZDR, Dresden (Germany); Arnold, Maurice; Aumaitre, Georges; Bourles, Didier; Martschini, Martin [ASTER, Aix-en-Provence (France); Buchriegler, Josef; Golser, Robin; Keddadouche, Karim; Steier, Peter [VERA, Vienna (Austria)

    2013-07-01

    Since the DREAMS (Dresden Accelerator Mass Spectrometry) facility went operational in 2011, constant effort was put into enabling routine measurements of long-lived radionuclides as {sup 10}Be, {sup 26}Al and {sup 41}Ca. For precise AMS-measurements of the volatile element Cl the key issue is the minimization of the long term memory effect. For this purpose one of the two original HVE sources was mechanically modified, allowing the usage of bigger cathodes with individual target apertures. Additionally a more open geometry was used to improve the vacuum level. To evaluate this improvement in comparison to other up-to-date ion sources, a small inter-laboratory comparison had been initiated. The long-term memory effect in the Cs sputter ion sources of the AMS facilities VERA, ASTER and DREAMS had been investigated by running samples of natural {sup 35}Cl/{sup 37}Cl-ratio and samples containing highly enriched {sup 35}Cl({sup 35}Cl/{sup 37}Cl > 500). Primary goals of the research are the time constants of the recovery from the contaminated sample ratio to the initial ratio of the sample and the level of the long-term memory effect in the sources.

  3. Installation of a tandem-type accelerator mass spectrometer

    International Nuclear Information System (INIS)

    Mizushima, Toshihiko; Togawa, Orihiko; Mizutani, Yoshihiko; Yamamoto, Tadatoshi

    2000-02-01

    Tandem-type accelerator mass spectrometer (hereinafter referred to as Tandetron) was installed at the Ominato Facility of Mutsu Establishment, JAERI in April, 1997. The objective of its installation is to investigate the mechanism of the mixing and circulation of seawater in the ocean, by collecting seawater samples around Japan and analyzing the horizontal and vertical distributions of 14 C contained in the samples. The Tandetron consists of two lines to measure isotopic ratios of carbon and those of heavier iodine. The adjustment for the carbon line was finished and the measurements of seawater samples were started. The iodine line, on the other hand, is on the final step of its adjustment and performance tests are being carried out with a TOF (Time of Flight) detector. The iodine line will be used to analyze 129 I released from a spent nuclear fuel reprocessing plant and other nuclear facilities. In this report, we summarize the status of installation of the carbon and iodine lines for the Tandetron. The report describes the situations of their adjustments until now, the outline of the Tandetron, tests of measurement performance, evaluation and inspection of shielding performance, problems and their solutions, and so on. (author)

  4. Detection of {sup 59}Ni by accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Per; Erlandsson, Bengt; Freimann, K.; Hellborg, R.; Stenstroem, K. [Lund Univ. (Sweden). Dept. of Nuclear Physics; Larsson, Ragnar [Lund Univ. (Sweden). Chemical Engineering II; Skog, G. [Lund Univ. (Sweden). Dept. of Quaternary Geology

    1999-02-01

    The aims of this project were to develop a method to measure the amount of {sup 59}Ni in stainless steel and to determine the detection limit for this method. {sup 59}Ni is produced by neutron activation in the construction material close to the core in a nuclear reactor and it is important to know the amount of {sup 59}Ni present as it governs the classification of the waste. If the amount of {sup 59}Ni is known at different locations in relation to the core, it is also possible to refine the calculation models of the neutron flux in the reactor. Accelerator mass spectrometry, an ultra-sensitive method for measuring small concentrations of radionuclides as well as stable nuclides, has been used in this investigation to determine the concentration of {sup 59}Ni (and thereby the activity) in stainless steel. As the cobalt content in stainless steel is the main contributor to the background in a measurement of {sup 59}Ni, a method for the chemical extraction of nickel from stainless steel, including a purification step to reduce the cobalt content in the sample, has been developed. The detection limit for {sup 59}Ni has been determined to 100{+-}30 Bq per gram nickel (100{+-}30 Bq/g) with the present status of the system 14 refs, 6 figs, 3 tabs

  5. Improving tritium exposure reconstructions using accelerator mass spectrometry

    Science.gov (United States)

    Hunt, J. R.; Vogel, J. S.; Knezovich, J. P.

    2010-01-01

    Direct measurement of tritium atoms by accelerator mass spectrometry (AMS) enables rapid low-activity tritium measurements from milligram-sized samples and permits greater ease of sample collection, faster throughput, and increased spatial and/or temporal resolution. Because existing methodologies for quantifying tritium have some significant limitations, the development of tritium AMS has allowed improvements in reconstructing tritium exposure concentrations from environmental measurements and provides an important additional tool in assessing the temporal and spatial distribution of chronic exposure. Tritium exposure reconstructions using AMS were previously demonstrated for a tree growing on known levels of tritiated water and for trees exposed to atmospheric releases of tritiated water vapor. In these analyses, tritium levels were measured from milligram-sized samples with sample preparation times of a few days. Hundreds of samples were analyzed within a few months of sample collection and resulted in the reconstruction of spatial and temporal exposure from tritium releases. Although the current quantification limit of tritium AMS is not adequate to determine natural environmental variations in tritium concentrations, it is expected to be sufficient for studies assessing possible health effects from chronic environmental tritium exposure. PMID:14735274

  6. Detection of 59Ni by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Persson, Per; Erlandsson, Bengt; Freimann, K.; Hellborg, R.; Stenstroem, K.; Larsson, Ragnar; Skog, G.

    1999-02-01

    The aims of this project were to develop a method to measure the amount of 59 Ni in stainless steel and to determine the detection limit for this method. 59 Ni is produced by neutron activation in the construction material close to the core in a nuclear reactor and it is important to know the amount of 59 Ni present as it governs the classification of the waste. If the amount of 59 Ni is known at different locations in relation to the core, it is also possible to refine the calculation models of the neutron flux in the reactor. Accelerator mass spectrometry, an ultra-sensitive method for measuring small concentrations of radionuclides as well as stable nuclides, has been used in this investigation to determine the concentration of 59 Ni (and thereby the activity) in stainless steel. As the cobalt content in stainless steel is the main contributor to the background in a measurement of 59 Ni, a method for the chemical extraction of nickel from stainless steel, including a purification step to reduce the cobalt content in the sample, has been developed. The detection limit for 59 Ni has been determined to 100±30 Bq per gram nickel (100±30 Bq/g) with the present status of the system

  7. Using accelerator mass spectrometry for radiocarbon dating of textiles

    International Nuclear Information System (INIS)

    Jull, A.J.T.

    1997-01-01

    Since 1981 we have operated an NSF Accelerator Mass Spectrometry (AMS) Facility at the University of Arizona. The AMS method allows us to use very small samples of carbon, 14 C in lunar samples by galactic and solar cosmic rays, studies of in situ 14 C produced by cosmic ray spallation in rocks and ice, and studies of 14 C in groundwater dissolved inorganic carbon and dissolved organic carbon. At our laboratory, we have also successfully applied AMS 14 C to dating of many types of textiles, including silks and linens, art works, documents and artifacts fabricated from wood, parchment, ivory, and bone. The results for many of these samples are often important in questions of the authenticity of these works of art and artifacts. Our studies have encompassed a wide range of art works ranging from the Dead Sea Scrolls, the Shroud of Turin, and the Chinese silk trade to the works of Raphael, Rembrandt, and Picasso. Recently, we also dated the Vinland Map, a controversial document that shows the eastern coast of North America apparently using information from Viking voyages

  8. Transition of Iodine Analysis to Accelerator Mass Spectrometry

    International Nuclear Information System (INIS)

    Watrous, Matthew George; Adamic, Mary Louise; Olson, John Eric; Baeck, D. L.; Fox, R. V.; Hahn, P. A.; Jenson, D. D.; Lister, T. E.

    2015-01-01

    The goal of the project, New Paradigms for Isotope Ratio Mass Spectrometry: Raising the Scientific Profile and Improved Performance for Accelerator Mass Spectrometry (AMS) and Thermal Ionization Mass Spectrometry (TIMS), is to ensure that the ongoing isotope ratio determination capability within the U.S. Department of Energy complex is the world's best for application to nonproliferation. This report spells out the progress of Task 4, Transition of TIMS to AMS for Iodine Analysis, of the larger project. The subtasks under Task 4 and the accomplishments throughout the three year project life cycle are presented in this report. Progress was made in optimization of chemical extraction, determination of a detection limit for 127Iodine, production of standard materials for AMS analysis quality assurance, facilitation of knowledge exchange with respect to analyzing iodine on an AMS, cross comparison with a world-leading AMS laboratory, supercritical fluid extraction of iodine for AMS analysis and electrodeposition of seawater as a direct method of preparation for iodine analysis by AMS--all with the goal of minimizing the time required to stand up an AMS capability for iodine analysis of exposed air filters at INL. An effective extraction method has been developed and demonstrated for iodine analysis of exposed air filters. Innovative techniques to accomplish the cathode preparation for AMS analysis were developed and demonstrated and published. The known gap of a lack of available materials for reference standards in the analysis of iodine by AMS was filled by the preparation of homogenous materials that were calibrated against NIST materials. A minimum limit on the amount of abundant isotope in a sample was determined for AMS analysis. The knowledge exchange occurred with fantastic success. Scientists engaged the international AMS community at conferences, as well as in their laboratories for collaborative work. The supercritical fluid extraction work has positive

  9. Transition of Iodine Analysis to Accelerator Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Watrous, Matthew George [Idaho National Lab. (INL), Idaho Falls, ID (United States); Adamic, Mary Louise [Idaho National Lab. (INL), Idaho Falls, ID (United States); Olson, John Eric [Idaho National Lab. (INL), Idaho Falls, ID (United States); Baeck, D. L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Fox, R. V. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hahn, P. A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Jenson, D. D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lister, T. E. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    The goal of the project, New Paradigms for Isotope Ratio Mass Spectrometry: Raising the Scientific Profile and Improved Performance for Accelerator Mass Spectrometry (AMS) and Thermal Ionization Mass Spectrometry (TIMS), is to ensure that the ongoing isotope ratio determination capability within the U.S. Department of Energy complex is the world’s best for application to nonproliferation. This report spells out the progress of Task 4, Transition of TIMS to AMS for Iodine Analysis, of the larger project. The subtasks under Task 4 and the accomplishments throughout the three year project life cycle are presented in this report. Progress was made in optimization of chemical extraction, determination of a detection limit for 127Iodine, production of standard materials for AMS analysis quality assurance, facilitation of knowledge exchange with respect to analyzing iodine on an AMS, cross comparison with a world-leading AMS laboratory, supercritical fluid extraction of iodine for AMS analysis and electrodeposition of seawater as a direct method of preparation for iodine analysis by AMS--all with the goal of minimizing the time required to stand up an AMS capability for iodine analysis of exposed air filters at INL. An effective extraction method has been developed and demonstrated for iodine analysis of exposed air filters. Innovative techniques to accomplish the cathode preparation for AMS analysis were developed and demonstrated and published. The known gap of a lack of available materials for reference standards in the analysis of iodine by AMS was filled by the preparation of homogenous materials that were calibrated against NIST materials. A minimum limit on the amount of abundant isotope in a sample was determined for AMS analysis. The knowledge exchange occurred with fantastic success. Scientists engaged the international AMS community at conferences, as well as in their laboratories for collaborative work. The supercritical fluid extraction work has positive

  10. Pushing the accelerator - speeding up drug research with accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Garner, R.C. E-mail: colin.garner@cbams.co.uk; Leong, D

    2000-10-01

    Accelerator mass spectrometry (AMS) is the most sensitive analytical method yet developed for elemental isotope analysis and has a broad range of applications. The measurement of {sup 14}C is of most interest to biomedical researchers but few studies have been reported using AMS in drug discovery and development. For biomedical use, {sup 14}C is incorporated into organic molecules by either radiosynthesis or biosynthetically and the isotope is used as a surrogate for the distribution of the radiolabelled molecule either in animal or human studies. The majority of users of {sup 14}C quantitate the radioactivity using decay counting usually with a liquid scintillation counter (LSC). Our Centre over the past 12 months has been evaluating and validating the use of AMS as an alternative detection method. In vitro spiking studies of human plasma with {sup 14}C-Fluconazole, a prescription antifungal drug has demonstrated an excellent correlation between AMS and LSC (correlation coefficient 0.999). Human Phase I clinical studies have been conducted with radioactive doses ranging from 120 Bq (7000 dpm) to 11 kBq (300 nCi) to provide mass balance, plasma concentration and radioactive metabolite profiling data. Limits of detection of 0.00022 Bq {sup 14}C-labelled drug/ml plasma have been accurately quantitated in a plasma background of 0.0078 Bq/ml (0.013 dpm/ml in a plasma background of 0.47 dpm/ml or 2.72 pMC in a background of 90.19 pMC)

  11. Using accelerator mass spectrometry for radiocarbon dating of textiles

    Energy Technology Data Exchange (ETDEWEB)

    Jull, A.J.T.

    1997-12-01

    Since 1981 we have operated an NSF Accelerator Mass Spectrometry (AMS) Facility at the University of Arizona. The AMS method allows us to use very small samples of carbon, <1 mg for radiocarbon dating in contrast to earlier counting techniques. This has opened a vast array of applications of radiocarbon dating that was difficult to do before AMS because of sample size limitations of decay counting. Some of the many applications of AMS include paleoclimatic studies, archaeological research and the age of first settlement of North America by man, dating of art works and artifacts, fall times and terrestrial residence ages of meteorites, production of {sup 14}C in lunar samples by galactic and solar cosmic rays, studies of in situ {sup 14}C produced by cosmic ray spallation in rocks and ice, and studies of {sup 14}C in groundwater dissolved inorganic carbon and dissolved organic carbon. At our laboratory, we have also successfully applied AMS {sup 14}C to dating of many types of textiles, including silks and linens, art works, documents and artifacts fabricated from wood, parchment, ivory, and bone. The results for many of these samples are often important in questions of the authenticity of these works of art and artifacts. Our studies have encompassed a wide range of art works ranging from the Dead Sea Scrolls, the Shroud of Turin, and the Chinese silk trade to the works of Raphael, Rembrandt, and Picasso. Recently, we also dated the Vinland Map, a controversial document that shows the eastern coast of North America apparently using information from Viking voyages.

  12. Resource for the Development of Biomedical Accelerator Mass Spectrometry (AMS)

    Energy Technology Data Exchange (ETDEWEB)

    Turteltaub, K. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bench, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Buchholz, B. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Enright, H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kulp, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McCartt, A. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Malfatti, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ognibene, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Loots, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Stewart, B. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-04-08

    The NIH Research Resource for Biomedical AMS was originally funded at Lawrence Livermore National Laboratory in 1999 to develop and apply the technology of accelerator mass spectrometry (AMS) in broad- based biomedical research. The Resource’s niche is to fill needs for ultra high sensitivity quantitation when isotope-labeled agents are used. The Research Resource’s Technology Research and Development (TR&D) efforts will focus on the needs of the biomedical research community in the context of seven Driving Biomedical Projects (DBPs) that will drive the Center’s technical capabilities through three core TR&Ds. We will expand our present capabilities by developing a fully integrated HPLC AMS to increase our capabilities for metabolic measurements, we will develop methods to understand cellular processes and we will develop and validate methods for the application of AMS in human studies, which is a growing area of demand by collaborators and service users. In addition, we will continue to support new and ongoing collaborative and service projects that require the capabilities of the Resource. The Center will continue to train researchers in the use of the AMS capabilities being developed, and the results of all efforts will be widely disseminated to advance progress in biomedical research. Towards these goals, our specific aims are to:1.) Increase the value and information content of AMS measurements by combining molecular speciation with quantitation of defined macromolecular isolates. Specifically, develop and validate methods for macromolecule labeling, characterization and quantitation.2.) Develop and validate methods and strategies to enable AMS to become more broadly used in human studies. Specifically, demonstrate robust methods for conducting pharmacokinetic/pharmacodynamics studies in humans and model systems.3.) Increase the accessibility of AMS to the Biomedical research community and the throughput of AMS through direct coupling to separatory

  13. Resource for the Development of Biomedical Accelerator Mass Spectrometry (AMS)

    Energy Technology Data Exchange (ETDEWEB)

    Tuerteltaub, K. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bench, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Buchholz, B. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Enright, H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kulp, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Loots, G. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McCartt, A. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Malfatti, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ognibene, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Stewart, B. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-03-21

    The NIH Research Resource for Biomedical AMS was originally funded at Lawrence Livermore National Laboratory in 1999 to develop and apply the technology of accelerator mass spectrometry (AMS) in broad- based biomedical research. The Resource’s niche is to fill needs for ultra high sensitivity quantitation when isotope-labeled agents are used. The Research Resource’s Technology Research and Development (TR&D) efforts will focus on the needs of the biomedical research community in the context of seven Driving Biomedical Projects (DBPs) that will drive the Center’s technical capabilities through three core TR&Ds. We will expand our present capabilities by developing a fully integrated HPLC AMS to increase our capabilities for metabolic measurements, we will develop methods to understand cellular processes and we will develop and validate methods for the application of AMS in human studies, which is a growing area of demand by collaborators and service users. In addition, we will continue to support new and ongoing collaborative and service projects that require the capabilities of the Resource. The Center will continue to train researchers in the use of the AMS capabilities being developed, and the results of all efforts will be widely disseminated to advance progress in biomedical research. Towards these goals, our specific aims are to:1.) Increase the value and information content of AMS measurements by combining molecular speciation with quantitation of defined macromolecular isolates. Specifically, develop and validate methods for macromolecule labeling, characterization and quantitation.2.) Develop and validate methods and strategies to enable AMS to become more broadly used in human studies. Specifically, demonstrate robust methods for conducting pharmacokinetic/pharmacodynamics studies in humans and model systems.3.) Increase the accessibility of AMS to the Biomedical research community and the throughput of AMS through direct coupling to separatory

  14. Radio-tracing 'without' radioactivity: accelerator mass spectrometry in biomedicine

    International Nuclear Information System (INIS)

    Vogel, J.S.

    2005-01-01

    Accelerator mass spectrometry (AMS) is a form of isotope-ratio mass spectrometry that quantifies concentrations of certain long-lived radioisotopes independently of their radioactive decay. AMS is primarily used in the geosciences for determining the age of a material that contains naturally occurring radioisotopes. AMS uses the same high specificity for enriched levels of these radioisotopes in tracing low chemical doses for long periods in biological systems, including humans. AMS provides the safety of low radiative exposure to experimental subjects and investigators, while obtaining attomole sensitivities that are not possible with stable isotope tracers because of their natural isotopic abundances. AMS isotope tracing was first applied to quantifying the genotoxicity of low level environmental chemicals in animals and later in humans. Physiologic concentrations of 14 C-labeled trace nutrients (folate, carotene, and tocopherol) are now measured directly in humans without concern about radiation. The radiative exposure is less than the commonly accepted risks of natural background radiation or the radiation fields found in high altitude air flights. AMS measures very small biological samples (such as 20 microliters of blood) that are easily obtained from human volunteers or model animals at frequent intervals for detailed analysis of kinetic profiles. This high data density enables the construction of compartmental models that elucidate nutrient behavior in tissues that cannot be directly sampled. The pharmaceutical industry is enthusiastic about AMS as a detector for 'micro-dosing' in which the human kinetics of an assuredly non-toxic dose of a candidate drug is tested early in a development project. Molecular tracing uses 3 H or 14 C as common isotopic labels, but AMS contributes to elemental tracing with certain radioisotopes having very long lives, such as 26 AL or 41 Ca. Calcium-41 is a particularly useful isotope in biomedical research because it is used

  15. The future of the accelerator mass spectrometry of rare long-lived radioactive isotopes

    International Nuclear Information System (INIS)

    Litherland, A.E.

    1990-01-01

    Accelerators, originally designed for nuclear physics, can be added to mass spectrometric apparatus to increase the sensitivity so that isotope ratios in the range 10 -12 to 10 -15 can be measured routinely. This significant improvement of high-sensitivity mass spectrometry has been called Accelerator Mass Spectrometry. The present article addresses the basic principles of accelerator mass spectrometry and some recent applications which show its versatility. In particular, it is noted that accelerator mass spectrometry could play an increasing role in the measurement of the levels of long lived radioactivities in the environment, including the actinides, which result from human activities such as the use of nuclear power. To fulfill this promise, continued research and development is necessary to provide ion sources, various types of heavy ion accelerators and peripheral magnetic and electric analysers. (N.K.)

  16. Analytical Validation of Accelerator Mass Spectrometry for Pharmaceutical Development: the Measurement of Carbon-14 Isotope Ratio

    International Nuclear Information System (INIS)

    Keck, B.D.; Ognibene, T.; Vogel, J.S.

    2010-01-01

    Accelerator mass spectrometry (AMS) is an isotope based measurement technology that utilizes carbon-14 labeled compounds in the pharmaceutical development process to measure compounds at very low concentrations, empowers microdosing as an investigational tool, and extends the utility of 14 C labeled compounds to dramatically lower levels. It is a form of isotope ratio mass spectrometry that can provide either measurements of total compound equivalents or, when coupled to separation technology such as chromatography, quantitation of specific compounds. The properties of AMS as a measurement technique are investigated here, and the parameters of method validation are shown. AMS, independent of any separation technique to which it may be coupled, is shown to be accurate, linear, precise, and robust. As the sensitivity and universality of AMS is constantly being explored and expanded, this work underpins many areas of pharmaceutical development including drug metabolism as well as absorption, distribution and excretion of pharmaceutical compounds as a fundamental step in drug development. The validation parameters for pharmaceutical analyses were examined for the accelerator mass spectrometry measurement of 14 C/C ratio, independent of chemical separation procedures. The isotope ratio measurement was specific (owing to the 14 C label), stable across samples storage conditions for at least one year, linear over 4 orders of magnitude with an analytical range from one tenth Modern to at least 2000 Modern (instrument specific). Further, accuracy was excellent between 1 and 3 percent while precision expressed as coefficient of variation is between 1 and 6% determined primarily by radiocarbon content and the time spent analyzing a sample. Sensitivity, expressed as LOD and LLOQ was 1 and 10 attomoles of carbon-14 (which can be expressed as compound equivalents) and for a typical small molecule labeled at 10% incorporated with 14 C corresponds to 30 fg equivalents. AMS

  17. Analytical Validation of Accelerator Mass Spectrometry for Pharmaceutical Development: the Measurement of Carbon-14 Isotope Ratio.

    Energy Technology Data Exchange (ETDEWEB)

    Keck, B D; Ognibene, T; Vogel, J S

    2010-02-05

    Accelerator mass spectrometry (AMS) is an isotope based measurement technology that utilizes carbon-14 labeled compounds in the pharmaceutical development process to measure compounds at very low concentrations, empowers microdosing as an investigational tool, and extends the utility of {sup 14}C labeled compounds to dramatically lower levels. It is a form of isotope ratio mass spectrometry that can provide either measurements of total compound equivalents or, when coupled to separation technology such as chromatography, quantitation of specific compounds. The properties of AMS as a measurement technique are investigated here, and the parameters of method validation are shown. AMS, independent of any separation technique to which it may be coupled, is shown to be accurate, linear, precise, and robust. As the sensitivity and universality of AMS is constantly being explored and expanded, this work underpins many areas of pharmaceutical development including drug metabolism as well as absorption, distribution and excretion of pharmaceutical compounds as a fundamental step in drug development. The validation parameters for pharmaceutical analyses were examined for the accelerator mass spectrometry measurement of {sup 14}C/C ratio, independent of chemical separation procedures. The isotope ratio measurement was specific (owing to the {sup 14}C label), stable across samples storage conditions for at least one year, linear over 4 orders of magnitude with an analytical range from one tenth Modern to at least 2000 Modern (instrument specific). Further, accuracy was excellent between 1 and 3 percent while precision expressed as coefficient of variation is between 1 and 6% determined primarily by radiocarbon content and the time spent analyzing a sample. Sensitivity, expressed as LOD and LLOQ was 1 and 10 attomoles of carbon-14 (which can be expressed as compound equivalents) and for a typical small molecule labeled at 10% incorporated with {sup 14}C corresponds to 30 fg

  18. Acceleration of the GrIS mass loss as observed by GRACE

    DEFF Research Database (Denmark)

    Svendsen, Peter Limkilde; Andersen, Ole Baltazar; Nielsen, Allan Aasbjerg

    2012-01-01

    The mass loss of the Greenland Ice Sheet (GrIS) has previously been analysed in a variety of ways, including altimetry, gravimetry and mass budget calculations, establishing a continuing decrease in the ice mass, with a number of studies finding acceleration in the mass loss. Here, we examine...

  19. Feasibility studies of RFQ based 14C accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Guo Zhiyu; Liu Kexin; Yan Xueqing; Xie Yi; Fang Jiaxun; Chen Jiaer

    2007-01-01

    Electrostatic accelerators with terminal voltage less than 1 MeV have been successfully used for 14 C AMS. This contribution shows that a small RFQ accelerator may also be suitable for AMS 14 C measurements. A well-designed RFQ accelerator can realize a low energy spread and high isotopic selection with a length of less than 1 m and reasonable power consumption. Compared with small tandem accelerators, a RFQ does not need isolation gas and can accept much higher beam currents. Its stripper would be at ground potential and there would be no further acceleration after stripping, so the background from charge exchange processes should be lower. The RFQ design and system are described

  20. Modeling energy flexibility of low energy buildings utilizing thermal mass

    DEFF Research Database (Denmark)

    Foteinaki, Kyriaki; Heller, Alfred; Rode, Carsten

    2016-01-01

    In the future energy system a considerable increase in the penetration of renewable energy is expected, challenging the stability of the system, as both production and consumption will have fluctuating patterns. Hence, the concept of energy flexibility will be necessary in order for the consumption...... to match the production patterns, shifting demand from on-peak hours to off-peak hours. Buildings could act as flexibility suppliers to the energy system, through load shifting potential, provided that the large thermal mass of the building stock could be utilized for energy storage. In the present study...... the load shifting potential of an apartment of a low energy building in Copenhagen is assessed, utilizing the heat storage capacity of the thermal mass when the heating system is switched off for relieving the energy system. It is shown that when using a 4-hour preheating period before switching off...

  1. Promoting International Cooperation and Public Acceptance in Utilizing Proton Accelerator Technology

    International Nuclear Information System (INIS)

    Choi, Byung Ho; Hahn, Bong Oh; Lee, Jae Hyung; Kim, Kyu Ryung; Joo, Po Kook; Kim, In Kyu; Kim, Hyun Joon; Noh, Seung Jeong

    2002-11-01

    Proton engineering's main tool will be a high power proton accelerator which is to be established within next 10 years in the frame of Proton engineering Frontier Project. It is necessary for public to understand the meaning and importance of the project so that Project activities such as site preparation can be efficiently completed. And, it is required to establish a sound plan of international cooperation, and to develop user program to establish domestic foundation in utilizing the accelerator. Along with public relations activities through newspapers and broadcasting, there were more than 20 times of project presentations requested by various local governments, universities, and scientific societies. which resulted in strong support of the project from various societies. Based on collected information through actual visits to and internet surveys on foreign accelerators, a recommendation of international cooperation scheme has been made to complement domestic technological weak points, and there were discussions with some foreign organizations for that purpose. Especially, KEK of Japan, IHEP of China and KAERI have been deliberating on planning detail cooperation programs in developing and utilizing accelerator among 3 countries Some research items related with NT/BT/IT and utilizing proton beam were planned to be implemented in the Project. And a user program implemented in the Project In order to be prepared for future use of the accelerator. In order to upbring junior researchers for future days, an accelerator summer school has been planned to be held annually inviting prominent foreign and domestic lecturers

  2. Observations of the Coronal Mass Ejection with a Complex Acceleration Profile

    Science.gov (United States)

    Reva, A. A.; Kirichenko, A. S.; Ulyanov, A. S.; Kuzin, S. V.

    2017-12-01

    We study the coronal mass ejection (CME) with a complex acceleration profile. The event occurred on 2009 April 23. It had an impulsive acceleration phase, an impulsive deceleration phase, and a second impulsive acceleration phase. During its evolution, the CME showed signatures of different acceleration mechanisms: kink instability, prominence drainage, flare reconnection, and a CME–CME collision. The special feature of the observations is the usage of the TESIS EUV telescope. The instrument could image the solar corona in the Fe 171 Å line up to a distance of 2 {R}ȯ from the center of the Sun. This allows us to trace the CME up to the LASCO/C2 field of view without losing the CME from sight. The onset of the CME was caused by kink instability. The mass drainage occurred after the kink instability. The mass drainage played only an auxiliary role: it decreased the CME mass, which helped to accelerate the CME. The first impulsive acceleration phase was caused by the flare reconnection. We observed the two-ribbon flare and an increase of the soft X-ray flux during the first impulsive acceleration phase. The impulsive deceleration and the second impulsive acceleration phases were caused by the CME–CME collision. The studied event shows that CMEs are complex phenomena that cannot be explained with only one acceleration mechanism. We should seek a combination of different mechanisms that accelerate CMEs at different stages of their evolution.

  3. Correlation analysis of measurement result between accelerator mass spectrometry and gamma counter

    International Nuclear Information System (INIS)

    Minamimoto, Ryogo; Cheng, C.; Oka, Takashi; Inoue, Tomio; Hamabe, Yoshimi; Shimoda, Marika

    2010-01-01

    The guidelines for microdosing in clinical trials were published in Japan in 2008 following the guidelines of the European Medicines Agency and the Food and Drug Administration. They recommend utilizing accelerator mass spectrometry (AMS) and positron emission tomography as candidates for monitoring drug metabolites in preclinical studies. We correlate the two methods by measuring appropriately labeled tissue samples from various mouse organs using both AMS and gamma counter. First, we measured the 14 C background levels in mouse organs using the AMS system. We then clarified the relationship between AMS and gamma counter by simultaneously administering 14 C-2-fluoro-2-deoxyglucose ( 14 C-FDG) and 18 F-2-fluoro-2-deoxyglucose ( 18 F-FDG). Tissue distribution was examined after 30 min, 1 h, 2 h and 4 h using the AMS system for 14 C-FDG and gamma counter for 18 F-FDG. Background 14 C levels were subtracted from the data obtained with radiotracer administration. The background 14 C concentration differed with tissue type measured. Background 14 C concentration in mouse liver was higher than in other organs, and was approximately 1.5-fold that in blood. The correlation coefficient (r) of the measurements between AMS ( 14 C-FDG) and gamma counter ( 18 F-FDG) was high in both normal (0.99 in blood, 0.91 in brain, 0.61 in liver and 0.78 in kidney) and tumor-bearing mice (0.95 in blood and 0.99 in tumor). The clearance profile of 18 F-FDG was nearly identical to that of 14 C-FDG measured with AMS. Accelerator mass spectrometry analysis has an excellent correlation with biodistribution measurements using gamma counter. Our results suggest that the combination of AMS and positron emission tomography (PET) can act as a complementary approach to accelerate drug development. (author)

  4. Comparison of sampling methods for radiocarbon dating of carbonyls in air samples via accelerator mass spectrometry

    Science.gov (United States)

    Schindler, Matthias; Kretschmer, Wolfgang; Scharf, Andreas; Tschekalinskij, Alexander

    2016-05-01

    Three new methods to sample and prepare various carbonyl compounds for radiocarbon measurements were developed and tested. Two of these procedures utilized the Strecker synthetic method to form amino acids from carbonyl compounds with either sodium cyanide or trimethylsilyl cyanide. The third procedure used semicarbazide to form crystalline carbazones with the carbonyl compounds. The resulting amino acids and semicarbazones were then separated and purified using thin layer chromatography. The separated compounds were then combusted to CO2 and reduced to graphite to determine 14C content by accelerator mass spectrometry (AMS). All of these methods were also compared with the standard carbonyl compound sampling method wherein a compound is derivatized with 2,4-dinitrophenylhydrazine and then separated by high-performance liquid chromatography (HPLC).

  5. Comparison of sampling methods for radiocarbon dating of carbonyls in air samples via accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, Matthias, E-mail: matthias.schindler@physik.uni-erlangen.de; Kretschmer, Wolfgang; Scharf, Andreas; Tschekalinskij, Alexander

    2016-05-15

    Three new methods to sample and prepare various carbonyl compounds for radiocarbon measurements were developed and tested. Two of these procedures utilized the Strecker synthetic method to form amino acids from carbonyl compounds with either sodium cyanide or trimethylsilyl cyanide. The third procedure used semicarbazide to form crystalline carbazones with the carbonyl compounds. The resulting amino acids and semicarbazones were then separated and purified using thin layer chromatography. The separated compounds were then combusted to CO{sub 2} and reduced to graphite to determine {sup 14}C content by accelerator mass spectrometry (AMS). All of these methods were also compared with the standard carbonyl compound sampling method wherein a compound is derivatized with 2,4-dinitrophenylhydrazine and then separated by high-performance liquid chromatography (HPLC).

  6. Annual report of Department of Research Reactor and Tandem Accelerator, JFY2007. Operation, utilization and technical development of JRR-3, JRR-4, NSRR and tandem accelerator

    International Nuclear Information System (INIS)

    Miyazaki, Osamu; Awa, Yasuaki; Isaka, Koji; Kutsukake, Kenichi; Komeda, Masao; Shibata, Ko; Hiyama, Kazuhisa; Suzuki, Mayu; Sone, Takuya; Ohuchi, Tomoaki; Terakado, Yuichi; Sataka, Masao

    2009-06-01

    The Department of Research Reactors and Tandem Accelerator is in charge of the operation, utilization and technical development of JRR-3(Japan Research Reactor-3), JRR-4(Japan Research Reactor-4), NSRR(Nuclear Safety Research Reactor) and Tandem Accelerator. This annual report describes a summary of activities of services and technical developments carried out in the period between April 1, 2007 and March 31, 2008. The activities were categorized into five service/development fields: (1) Operation and maintenance of research reactors and tandem accelerator. (2) Utilization of research reactors and tandem accelerator. (3) Upgrading of utilization techniques of research reactors and tandem accelerator. (4) Safety administration for research reactors and tandem accelerator. (5) International cooperation. Also contained are lists of publications, meetings, granted permissions on lows and regulations concerning atomic energy, commendation, plans and outcomes in service and technical developments and so on. (author)

  7. Annual report of Department of Research Reactor and Tandem Accelerator, JFY2010. Operation, utilization and technical development of JRR-3, JRR-4, NSRR and Tandem Accelerator

    International Nuclear Information System (INIS)

    Ishii, Tetsuro; Nakamura, Kiyoshi; Kawamata, Satoshi; Yamada, Yusuke; Kawashima, Kazuhiro; Asozu, Takuhiro; Nakamura, Takemi; Arai, Masaji; Yoshinari, Shuji; Sataka, Masao

    2012-03-01

    The Department of Research Reactors and Tandem Accelerator is in charge of the operation, utilization and technical development of JRR-3(Japan Research Reactor No.3), JRR-4(Japan Research Reactor No.4), NSRR(Nuclear Safety Research Reactor) and Tandem Accelerator. This annual report describes a summary of activities of services and technical developments carried out in the period between April 1, 2010 and March 31, 2011. The activities were categorized into five service/development fields: (1) Operation and maintenance of research reactors and tandem accelerator, (2) Utilization of research reactors and tandem accelerator, (3) Upgrading of utilization techniques of research reactors and tandem accelerator, (4) Safety administration for research reactors and tandem accelerator, (5) International cooperation. Also contained are lists of publications, meetings, granted permissions on lows and regulations concerning atomic energy, commendation, outcomes in service and technical developments and so on. (author)

  8. The advantages of orthogonal acceleration in ICP time-of-flight mass spectrometry

    International Nuclear Information System (INIS)

    Gaal, Andrew

    2004-01-01

    The OptiMass 8000 incorporates an orthogonal acceleration time-of-flight mass spectrometer. A general schematic of the instrument is given. The continuous ion beam is chopped by an orthogonal accelerator. A push out pulse supply is coupled to the accelerator for providing repetitive push-out voltages at a frequency of 30 kHz. The ion packets that are sliced out of the beam then travel within the field free space towards the SMARTGATE ion blanker. Orthogonal accelerator parameters are set to enable temporal-spatial focusing at the SMARTGATE ion blanker, so that iso-mass ion packets are resolved in time. Any ion packets of unwanted specie are ejected from the direction of travel by supplying pulsed voltages onto the deflection plates of the SMARTGATE. The ions to be measured are let through SMARTGATE and travel further down the field free space, to enter the ion reflectron. The ion reflectron increases the resolution of the mass spectrometer by means of temporal-energy focussing. After reflection, the ions travel within the field free space towards the discrete-dynode detector. In comparison to other acceleration geometries used in elemental time-of-flight mass spectrometry the OptiMass 8000 orthogonal acceleration geometry ultimately leads to superior resolution. As the energy spread is about 3 orders of magnitude lower in the time-of-flight direction for an oaTOFMS in comparison to an on-axis system, aberration acquired in the initial stages of acceleration are much lower. As a result the orthogonal acceleration scheme provides superior resolution at the first spatial focus point and the detector. The orthogonal acceleration time-of-flight analyzer of the OptiMass 8000 is able to provide resolution of at least 1800 at mass 238. (author)

  9. Historical evolution of nuclear energy systems development and related activities in JAERI. Fission, fusion, accelerator utilization

    Energy Technology Data Exchange (ETDEWEB)

    Tone, Tatsuzo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-03-01

    Overview of the historical evolution of nuclear energy systems development and related activities in JAERI is given in the report. This report reviews the research and development for light water reactor, fast breeder reactor, high temperature gas reactor, fusion reactor and utilization of accelerator-based neutron source. (author)

  10. Accelerator mass spectrometry researches at NIES-TERRA

    International Nuclear Information System (INIS)

    Shibata, Yasuyuki; Yoneda, Minoru; Tanaka, Atsushi; Uehiro, Takashi; Morita, Masatoshi; Uchida, Masao; Yoshinaga, Jun

    2003-01-01

    In the AMS facility at the National Institute for Environmental Studies (NIES-TERRA; Tandem accelerator for Environmental Research and Radiocarbon Analysis), several research programs have been proceeded, including a program, called GC-AMS, for the compound-specific 14 C analysis in environmental samples

  11. Accelerator Mass Spectrometry with 15 UD pelletron at the Nuclear Science Centre, New Delhi

    International Nuclear Information System (INIS)

    Datta, S.K.

    1997-01-01

    The 15 UD Pelletron machine is widely used to carry on investigations in a variety of disciplines like nuclear physics, materials science, radiobiology etc. Accelerator Mass Spectrometry studies with 15 UD pelletron machine at Nuclear Science Centre are elaborated

  12. Radioecological studies at the National Accelerator Centre based on the determination of 129I by accelerator mass spectrometry (AMS)

    International Nuclear Information System (INIS)

    Lopez-Gutierrez, J. M.; Gomez-Guzman, J. M.; Chamizo, E.; Santos, F. J.; Garcia-Leon, M.; Garcia-Tenorio, R.

    2013-01-01

    Since 2006 a compact system of mass spectrometry with Accelerator (AMS) is installed at the National Center of Accelerators, Seville. After an initial set-up and study have been opening many lines of research in fields such as archeology, geology, paleontology, oceanography, oceanography, internal dosimetry and characterization of radioactive waste, among others. In particular, based on the measurement of 1 29I have made contributions to the field of radioecology and radiation protection. In this work they are summarized and presented some of these investigations. (Author)

  13. Development of the Accelerator Mass Spectrometry technology at the Comenius University in Bratislava

    Energy Technology Data Exchange (ETDEWEB)

    Povinec, Pavel P., E-mail: povinec@fmph.uniba.sk; Masarik, Jozef; Ješkovský, Miroslav; Kaizer, Jakub; Šivo, Alexander; Breier, Robert; Pánik, Ján; Staníček, Jaroslav; Richtáriková, Marta; Zahoran, Miroslav; Zeman, Jakub

    2015-10-15

    An Accelerator Mass Spectrometry (AMS) laboratory has been established at the Centre for Nuclear and Accelerator Technologies (CENTA) at the Comenius University in Bratislava comprising of a MC-SNICS ion source, 3 MV Pelletron tandem accelerator, and an analyzer of accelerated ions. The preparation of targets for {sup 14}C and {sup 129}I AMS measurements is described in detail. The development of AMS techniques for potassium, uranium and thorium analysis in radiopure materials required for ultra-low background underground experiments is briefly mentioned.

  14. Development of the Accelerator Mass Spectrometry technology at the Comenius University in Bratislava

    Science.gov (United States)

    Povinec, Pavel P.; Masarik, Jozef; Ješkovský, Miroslav; Kaizer, Jakub; Šivo, Alexander; Breier, Robert; Pánik, Ján; Staníček, Jaroslav; Richtáriková, Marta; Zahoran, Miroslav; Zeman, Jakub

    2015-10-01

    An Accelerator Mass Spectrometry (AMS) laboratory has been established at the Centre for Nuclear and Accelerator Technologies (CENTA) at the Comenius University in Bratislava comprising of a MC-SNICS ion source, 3 MV Pelletron tandem accelerator, and an analyzer of accelerated ions. The preparation of targets for 14C and 129I AMS measurements is described in detail. The development of AMS techniques for potassium, uranium and thorium analysis in radiopure materials required for ultra-low background underground experiments is briefly mentioned.

  15. Accelerated mass loss from Greenland ice sheet : Links to atmospheric circulation in the North Atlantic

    NARCIS (Netherlands)

    Seo, Ki-Weon; Waliser, Duane E.; Lee, Choon-Ki; Tian, Baijun; Scambos, Ted; Kim, Baek-Min; van Angelen, Jan H.; van den Broeke, Michiel R.

    Understanding the mechanisms that drive the mass imbalance of the Greenland ice sheet (GrIS) is critical to the accurate projection of its contribution to future sea level rise. Greenland's ice mass loss has been accelerating recently. Using satellite Earth-gravity and regional climate model data,

  16. A compact permanent magnet cyclotrino for accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Young, A.T.; Clark, D.J.; Kunkel, W.B.; Leung, K.N.; Li, C.Y. [Lawrence Berkeley Lab., CA (United States)

    1995-02-01

    The authors describe the development of a new instrument for the detection of trace amounts of rare isotopes, a Cyclotron Mass Spectrometer (CMS). A compact low energy cyclotron optimized for high mass resolution has been designed and has been fabricated. The instrument has high sensitivity and is designed to measure carbon-14 at abundances of < 10{sup {minus}12}. A novel feature of the instrument is the use of permanent magnets to energize the iron poles of the cyclotron. The instrument uses axial injection, employing a spiral inflector. The instrument has been assembled and preliminary measurements of the magnetic field show that it has a uniformity on the order of 2 parts in 10{sup 4}.

  17. The origin of mass and experiments on high-energy particle accelerators

    International Nuclear Information System (INIS)

    Ioffe, B.L.

    2006-01-01

    The visible world is one consisting of nucleons and electrons. The mass of nucleon arises from chiral symmetry breaking in quantum chromodynamics, so high energy accelerator experiments cannot give a clue to the nature of mass of matter in the visible world. The origin of the mass of the matter will be clarified when the mechanism of chiral symmetry breaking in quantum chromodynamics is established [ru

  18. Accelerator mass spectrometry at the University of Washington

    International Nuclear Information System (INIS)

    Farwell, G.W.; Schmidt, F.H.; Grootes, P.M.

    1981-01-01

    Our program is directed toward measurement of 10 Be and 14 C using the FN Tandem accelerator of the Nuclear Physics Laboratory. We began work in June 1977. Our progress and results up to August, 1979, were reported at the Tenth International Radiocarbon Conference. The present report covers chiefly our work since then. For 14 C, we are in the final stages of testing a new sample changer and alternator and are comparing three systems of normalizing the rare and abundant ion beams to give isotope ratios. We have successfully prepared graphitized carbon source samples from contemporary and other material; while the graphitized sources have given the largest carbon beams, we are exploring other possibilities, among which the use of C/Ag combinations appears very promising. For 10 Be, we have begun testing and measuring samples prepared from Antarctic and Peruvian snow and ice. In both the carbon and the beryllium programs various technical developments are in progress in addition to those reported here

  19. Experience utilizing a 3.7 MeV tandem cascade accelerator (TCA) for PET radioisotope production

    International Nuclear Information System (INIS)

    Welch, M.J.; Gaehle, G.; Dence, C.S.

    1994-01-01

    A 3.7 MeV TCA was installed at Washington University in the Spring of 1993 for evaluation as a PET isotope production accelerator. The accelerator was installed in a specially designed suite consisting of the accelerator room, a open-quotes hot labclose quotes and a open-quotes cold labclose quotes. The accelerator has been utilized routinely for PET isotope production since it's installation. Although the major radionuclide produced utilizing the TCA is oxygen-15, techniques for the production of fluorine-18 and nitrogen-13 have been developed. The novel techniques used to produce usable quantities of these latter two isotopes will be discussed

  20. Accelerator mass spectrometry of 59Ni and Fe isotopes at the Argonne superconducting linac

    International Nuclear Information System (INIS)

    Henning, W.; Kutschera, W.; Myslek-Laurikainen, B.; Pardo, R.C.; Smither, R.K.; Yntema, J.L.

    1981-01-01

    We have obtained initial results in an attempt to use the Argonne tandem-linac system for accelerator mass spectrometry of medium-heavy nuclei. Nuclei of the radioisotope 59 Ni (T/sub 1/2 = 7.5 x 10 5 y) and of the stable isotope 58 Fe at low concentrations have been accelerated and clearly identified. The latter experiment is in preparation of a measurement of the half-life of 60 Fe

  1. Earth and environmental sciences by accelerator mass spectrometry (AMS) with the large tandem accelerator

    International Nuclear Information System (INIS)

    Sasa, K.; Takahashi, T.; Sueki, K.

    2008-01-01

    A multi-nuclide AMS system on the 12UD Pelletron tandem accelerator at the University of Tsukuba (Tsukuba AMS system) has been able to measure environmental levels of long lived radioisotopes of 14 C, 26 Al, 36 Cl and 129 I by employing a molecular pilot beam method. In addition, we have been developing 32 Si and 41 Ca AMS systems for future research programs. Recently, the performance of 36 Cl AMS was improved in AMS technique. The standard deviation is within ±2%, and the background is better than 5 x 10 -15 for the 36 Cl/Cl ratio. At present, our Tsukuba AMS research group has focused its activities especially on the measurement of 36 Cl. We have measured more than 500 samples in year including earth and environmental sciences with the Tsukuba AMS system. A detailed description of the Tsukuba AMS system is given and earth and environmental applications are also described briefly. (author)

  2. Accelerating Twisted Mass LQCD with QPhiX

    Energy Technology Data Exchange (ETDEWEB)

    Schröck, Mario [INFN, Rome3; Simula, Silvano [INFN, Rome3; Strelchenko, Alexei [Fermilab

    2016-07-08

    We present the implementation of twisted mass fermion operators for the QPhiX library. We analyze the performance on the Intel Xeon Phi (Knights Corner) coprocessor as well as on Intel Xeon Haswell CPUs. In particular, we demonstrate that on the Xeon Phi 7120P the Dslash kernel is able to reach 80\\% of the theoretical peak bandwidth, while on a Xeon Haswell E5-2630 CPU our generated code for the Dslash operator with AVX2 instructions outperforms the corresponding implementation in the tmLQCD library by a factor of $\\sim 5\\times$ in single precision. We strong scale the code up to 6.8 (14.1) Tflops in single (half) precision on 64 Xeon Haswell CPUs.

  3. Accelerator Mass Spectrometry at the Nuclear Science Laboratory: Applications to Nuclear Astrophysics

    Science.gov (United States)

    Collon, P.; Bauder, W.; Bowers, M.; Lu, W.; Ostdiek, K.; Robertson, D.

    The Accelerator Mass Spectrometry (AMS) program at the Nuclear Science Laboratory of the University of Notre Dame is focused on measurements related to galactic radioactivity and to nucleosynthesis of main stellar burning as well as the production of so called Short-Lived Radionuclides (SLRs) in the Early Solar System (ESS). The research program is based around the 11MV FN tandem accelerator and the use of the gas-filled magnet technique for isobar separation. Using a technique that evolved from radiocarbon dating, this paper presents a number of research programs that rely on the use of an 11MV tandem accelerator at the center of the AMS program.

  4. Interface for the rapid analysis of liquid samples by accelerator mass spectrometry

    Science.gov (United States)

    Turteltaub, Kenneth; Ognibene, Ted; Thomas, Avi; Daley, Paul F; Salazar Quintero, Gary A; Bench, Graham

    2014-02-04

    An interface for the analysis of liquid sample having carbon content by an accelerator mass spectrometer including a wire, defects on the wire, a system for moving the wire, a droplet maker for producing droplets of the liquid sample and placing the droplets of the liquid sample on the wire in the defects, a system that converts the carbon content of the droplets of the liquid sample to carbon dioxide gas in a helium stream, and a gas-accepting ion source connected to the accelerator mass spectrometer that receives the carbon dioxide gas of the sample in a helium stream and introduces the carbon dioxide gas of the sample into the accelerator mass spectrometer.

  5. Plasma Desorption Mass Spectrometry using TANDEM accelerator in National Industrial Research Inst. of Nagoya

    Energy Technology Data Exchange (ETDEWEB)

    Mizota, Takeshi; Nakao, Setsuo; Niwa, Hiroaki; Saito, Kazuo [Particle Beam Sceince Laboratory, Multi-Function Material Science Department, National Industrial Research Inst. of Nagoya, Nagoya (Japan)

    2001-02-01

    Plasma Desorption Mass Spectrometry (PDMS) analysis was studied using TANDEM accelerator. The heavy ions of MeV range emit the secondary ions of atoms, molecules, polymers and clusters from the irradiated samples without destruction. The analysis system of PDMS designed and set-up using a mass spectrometer of Time of Flight and the TANDEM accelerator. The system performance was tested for C-60 fullerene on the surface of the samples using 11.2 MeV {sup 28}Si beams produced by the TANDEM accelerator of 1.7MV. The result shows that the hydrogen and hydrocarbons can be analyzed in the range of 1amu unit. The resolution (M/{delta}M) of the Mass Spectrometry system is confirmed to be about 1000 from the separation of the 720 and 721amu peaks, which is attributed to the C-60 fullerene including {sup 13}C atoms. (H. Katsuta)

  6. Utilization of 5 MeV electron accelerator center and perspective

    International Nuclear Information System (INIS)

    Tanaka, Hiromi

    1990-01-01

    Electron beam process gives instantaneous effect as compared with heating process, and has such merits that energy consumption is very small, objects can be treated from outside, harmful chemicals are not used and treatment can be done as packed. The spread of electron beam process is largely due to the results of the development of highly reliable accelerators and utilization technologies, but as observed from all industrial fields, it is limited to only a part. In order to contribute to the solution of problems and the spread of electron beam process, Sumitomo Heavy Industries, Ltd. installed a 5 MeV, 200 kW large power accelerator developed by RDI in USA in the Electron Irradiation Application and Development Center opened in Tsukuba City. The Center was completed in June, 1989, and has carried out the activities of the development of irradiation utilization technologies, test irradiation and entrusted irradiation service. The features of electron beam process are high dose rate, the possibility of on and off as occasion demands, the preparation of radiation sources and the disposal of wastes being unnecessary, and no environmental problem. The industrialized processes, the types, energy and use of electron accelerators, the Tsukuba irradiation facilities and others are reported. (K.I.)

  7. New method for laser driven ion acceleration with isolated, mass-limited targets

    International Nuclear Information System (INIS)

    Paasch-Colberg, T.; Sokollik, T.; Gorling, K.; Eichmann, U.; Steinke, S.; Schnuerer, M.; Nickles, P.V.; Andreev, A.; Sandner, W.

    2011-01-01

    A new technique to investigate laser driven ion acceleration with fully isolated, mass-limited glass spheres with a diameter down to 8μm is presented. A Paul trap was used to prepare a levitating glass sphere for the interaction with a laser pulse of relativistic intensity. Narrow-bandwidth energy spectra of protons and oxygen ions have been observed and were attributed to specific acceleration field dynamics in case of the spherical target geometry. A general limiting mechanism has been found that explains the experimentally observed ion energies for the mass-limited target.

  8. Improving Utility of GPU in Accelerating Industrial Applications with User-centred Automatic Code Translation

    DEFF Research Database (Denmark)

    Yang, Po; Dong, Feng; Codreanu, Valeriu

    2018-01-01

    design and hard-to-use. Little attentions have been paid to the applicability, usability and learnability of these tools for normal users. In this paper, we present an online automated CPU-to-GPU source translation system, (GPSME) for inexperienced users to utilize GPU capability in accelerating general...... SME applications. This system designs and implements a directive programming model with new kernel generation scheme and memory management hierarchy to optimize its performance. A web service interface is designed for inexperienced users to easily and flexibly invoke the automatic resource translator...

  9. Annual report of Department of Research Reactor and Tandem Accelerator, JFY2011. Operation, utilization and technical development of JRR-3, JRR-4, NSRR and tandem accelerator

    International Nuclear Information System (INIS)

    Ishii, Tetsuro; Nakamura, Kiyoshi; Kawamata, Satoshi; Ishikuro, Yasuhiro; Kawashima, Kazuhito; Kabumoto, Hiroshi; Nakamura, Takemi; Tamura, Itaru; Kawasaki, Sayuri; Sataka, Masao

    2013-03-01

    The Department of Research Reactors and Tandem Accelerator is in charge of the operation, utilization and technical development of JRR-3(Japan Research Reactor No.3), JRR-4(Japan Research Reactor No.4), NSRR(Nuclear Safety Research Reactor) and Tandem Accelerator. This annual report describes a summary of activities of services and technical developments carried out in the period between April 1, 2011 and March 31, 2012. The activities were categorized into six service/development fields: (1) Recovery from the Great East Japan Earthquake, (2) Operation and maintenance of research reactors and tandem accelerator, (3) Utilization of research reactors and tandem accelerator, (4) Upgrading of utilization techniques of research reactors and tandem accelerator, (5) Safety administration for research reactors and tandem accelerator, (6) International cooperation. Also contained are lists of publications, meetings, granted permissions on lows and regulations concerning atomic energy, number of staff members dispatched to Fukushima for the technical assistance, commendation, outcomes in service and technical developments and so on. (author)

  10. Accelerator mass spectrometry of heavy elements: /sup 36/Cl to /sup 205/Pb

    Energy Technology Data Exchange (ETDEWEB)

    Henning, W

    1987-08-25

    Measurements are discussed in which the technique of accelerator mass spectrometry was applied to problems involving heavy radioisotopes. These measurements, which depend on the ion energies that can be reached with the new heavy-ion accelerator facilities, were performed at the Argonne tandem linac accelerator system (ATLAS) and at the UNILAC accelerator at GSI. The topics include a discussion of measurements of long nuclear lifetimes, of radioisotope detection of interest to solar neutrino experiments, and of a determination of the /sup 41/Ca concentration in natural samples of terrestrial origin by making use of isotopic pre-enrichment in an isotope separator. A long-known method of isobar separation, employing a gas-filled magnetic field region, has been revived for some of these measurements and its characteristics and advantages are briefly reviewed.

  11. Development of accelerator mass spectrometry in China Institute of Atomic Energy

    International Nuclear Information System (INIS)

    He Ming; Jiang Shan; Dong Kejun; Qiu Jiuzi; Peng Bo; Guan Yongjing; Yin Xinyi; Wu Shaoyong; Li Shihong; Zhou Duo

    2005-01-01

    The measurement method for some radio isotope such as 99 Tc, 182 Hf, 151 Sm is developing in China Institute of Atomic Energy (CIAE) accelerator mass spectrometry (AMS) system, and applications in the fields of nuclear physics, geosciences, life science and materials science is carried out. The brief introduction of these methods and applications are described in this paper. (authors)

  12. Accelerator mass spectrometry radiocarbon ages of amino acid extracts from Californian palaeoindian skeletons

    International Nuclear Information System (INIS)

    Bada, J.L.; Gillespie, R.; Gowlett, J.A.J.; Hedges, R.E.M.

    1984-01-01

    The authors have used accelerator mass spectrometry to determine the radiocarbon ages of the amino acid extracts used in the original racemization studies of skeletal remains found in California. The studies indicate that some of the controversial Californian skeletons, which had been assigned to the Upper Pleistocene, are in fact Holocene. (author)

  13. Phantom dark energy with varying-mass dark matter particles: Acceleration and cosmic coincidence problem

    International Nuclear Information System (INIS)

    Leon, Genly; Saridakis, Emmanuel N.

    2010-01-01

    We investigate several varying-mass dark matter particle models in the framework of phantom cosmology. We examine whether there exist late-time cosmological solutions, corresponding to an accelerating universe and possessing dark energy and dark matter densities of the same order. Imposing exponential or power-law potentials and exponential or power-law mass dependence, we conclude that the coincidence problem cannot be solved or even alleviated. Thus, if dark energy is attributed to the phantom paradigm, varying-mass dark matter models cannot fulfill the basic requirement that led to their construction.

  14. Determination of "1"3"5Cs by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    MacDonald, C.M.; Charles, C.R.J.; Zhao, X.-L.; Kieser, W.E.; Cornett, R.J.; Litherland, A.E.

    2015-01-01

    The ratio of anthropogenic "1"3"5Cs and "1"3"7Cs isotopes is characteristic of a uranium fission source. This research evaluates the technique of isotope dilution (yield tracing) for the purpose of quantifying "1"3"5Cs by accelerator mass spectrometry with on-line isobar separation. Interferences from Ba, Zn_2, and isotopes of equal mass to charge ratios were successfully suppressed. However, some sample crosstalk from source contamination remains. The transmission and di-fluoride ionization efficiencies of Cs isotopes were found to be 8 × 10"−"3 and 1.7 × 10"−"7 respectively. This quantification of "1"3"5Cs using yield tracing by accelerator mass spectrometry shows promise for future environmental sample analysis once the issues of sample crosstalk and low efficiency can be resolved.

  15. Impact of Center-of-Mass Acceleration on the Performance of Ultramarathon Runners

    Directory of Open Access Journals (Sweden)

    Lin Shun-Ping

    2014-12-01

    Full Text Available Ultramarathon races are rapidly gaining popularity in several countries, raising interest for the improvement of training programs. The aim of this study was to use a triaxial accelerometer to compare the three-dimensional centerof- mass accelerations of two groups of ultramarathon runners with distinct performances during different running speeds and distances. Ten runners who participated in the 12-h Taipei International Ultramarathon Race underwent laboratory treadmill testing one month later. They were divided into an elite group (EG; n = 5 and a sub-elite group (SG; n = 5. The triaxial center-of-mass acceleration recorded during a level-surface progressive intensity running protocol (3, 6, 8, 9, 10, and 12 km/h; 5 min each was used for correlation analyses with running distance during the ultramarathon. The EG showed negative correlations between mediolateral (ML acceleration (r = −0.83 to −0.93, p < 0.05, and between anterior-posterior (AP acceleration and running distance (r = −0.8953 to −0.9653, p < 0.05, but not for vertical control of the center of mass. This study suggests that runners reduce stride length to minimize mediolateral sway and the effects of braking on the trunk; moreover, cadence must be increased to reduce braking effects and enhance impetus. Consequently, the competition level of ultramarathons can be elevated.

  16. Radionuclides in man and his environment measured by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Hellborg, Ragnar; Erlandsson, Bengt; Kiisk, Madis; Persson, Per; Skog, Goeran; Stenstroem, Kristina; Mattsson, Soeren; Leide-Svegborn, Sigrid; Olofsson, Mikael

    1999-01-01

    Accelerator mass spectrometry (AMS) is a highly sensitive analytical method for measuring very low concentrations of both radionuclides and stable nuclides. For radioanalytical purposes, the main advantages of AMS compared to conventional radiometric methods are the use of smaller samples (mg size) and shorter measuring times (less than one hour). In this report some current applications of the AMS technique at the Lund Pelletron accelerator are presented, in particular studies of 14 C-labeled pharmaceuticals used in clinical nuclear medicine and biomedical research

  17. Performance of the rebuilt SUERC single-stage accelerator mass spectrometer

    Science.gov (United States)

    Shanks, Richard P.; Ascough, Philippa L.; Dougans, Andrew; Gallacher, Paul; Gulliver, Pauline; Rood, Dylan H.; Xu, Sheng; Freeman, Stewart P. H. T.

    2015-10-01

    The SUERC bipolar single-stage accelerator mass spectrometer (SSAMS) has been dismantled and rebuilt to accommodate an additional rotatable pre-accelerator electrostatic spherical analyser (ESA) and a second ion source injector. This is for the attachment of an experimental positive-ion electron cyclotron resonance (ECR) ion source in addition to a Cs-sputter source. The ESA significantly suppresses oxygen interference to radiocarbon detection, and remaining measurement interference is now thought to be from 13C injected as 13CH molecule scattering off the plates of a second original pre-detector ESA.

  18. Study of the 27Al(n,2,)26Al reaction via accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Wallner, A.

    2000-06-01

    The excitation function for the 27 Al(n,2n) 26 Al reaction is expected to show a strongly non-linear behavior in the neutron-energy region around 14 MeV, the neutron energy in D-T plasmas; thus the production rate of 26 Al (t 1/2 =7.2*10 5 a) in D-T fusion environments can in principle be used to measure the temperature of such plasmas. Existing measurements, however, are strongly discordant. Therefore, a new accurate measurement of the 27 Al(n,2n) 26 Al cross sections in the near threshold region (E n =13.5-14.8 MeV) was performed with the goal to achieve relative cross sections with the highest accuracy possible. In addition, the measurements were also designed to provide good absolute cross-section values, as absolute cross sections are important for radioactive waste predictions. Samples of Al metal were irradiated with neutrons in the energy range near threshold (E th =13.55 MeV) at the Radiuminstitutes of both Vienna and St. Petersburg, and in Tokai-mura, Japan. In Tuebingen irradiations with neutrons of higher energies (17 and 19 MeV) were performed. The amount of 26 Al produced during the irradiations was measured via accelerator mass spectrometry (AMS) at the Vienna Environmental Research Accelerator (VERA). This work represents the first 26 Al measurements for this new facility. With this system, a background as low as 3*10 -15 for 26 Al/ 27 Al isotope ratios was obtained, corresponding to a (n,2n) cross section of 0.04 mb. Utilizing AMS, cross sections with much higher precision and considerably closer to the threshold than in previous investigations could be measured. The prerequisite for its application as a temperature monitor, namely a very well known shape of the excitation function was met. A quantitative prediction of the sensitivity of this method for monitoring the temperature in a D-T fusion plasma was therefore possible. For thermal plasmas temperature changes in the order of 5 to 15 % should be detectable. An even higher sensitivity was found

  19. Acceleration Signal Characteristics for Intuitional Mass Analysis of Metallic Loose Parts

    International Nuclear Information System (INIS)

    Lee, Kwang-Hyun; Jung, Chang-Gyu

    2016-01-01

    Nuclear power plants (NPPs) have operated LPMS (Loose Parts Monitoring System) for early detection of the possible presence of metallic parts in the reactor coolant system (RCS); however, analysis of the metallic impact wave characteristics in the LPMS is an important issue because information, such as the mass of the metallic part and the impact location, is not provided. Most studies have concentrated on fieldwork using the frequency characteristics for the analysis of the metallic part mass. Thus, the field engineers cannot analyze signals without special software and access to the system. This paper is intended to introduce a process of intuitional mass analysis using the attenuation rate of the acceleration signal and the intervals between peak signals. Most studies related to mass analysis of a metallic part impact signal in LPMS have used the frequency spectrum. This paper presents a method of using the acceleration signal characteristics for intuitional mass analysis of loose metallic parts. With the method proposed in this paper, because the mass of a metallic part can be understood intuitionally without any special analysis program, intuitional analysis used in parallel with frequency spectrum analysis will be in effect

  20. Importance of the virtual mass force in accelerating steam/water mixtures

    International Nuclear Information System (INIS)

    Khalil, Y.F.; Kazimi, M.S.

    1987-01-01

    Virtual mass force is one of the forces that must be considered against accelerating a dispersed fluid flowing in the bulk of a continuous fluid. This force depends on the geometry of the interface and the flow pattern of the two fluids. For dilute two-phase flow mixtures where the bubbles are singly dispersed, the value of the virtual mass force coefficient is dependent on the geometry of the bubble. However, for high void fraction cases, such as depressurization initiated by a pipe break in light water reactors, more intense interaction is expected between the two phase and, therefore, the value of the virtual mass force must be well defined. The effects of implementing the virtual mass force term in the momentum equations of a two-fluid model may be significant for improving the stability of the solution of the conservation equations, the accuracy of the numerical results, and the computation time. In the current work, a new stability criterion is derived after implementing Hancox's model for the virtual mass force in the momentum equations of the six-equation two-phase flow model of TERMIT. A one-dimensional blow-down in a horizontal pipe is considered to investigate the importance of incorporating the virtual mass force in accelerating mixtures flows

  1. Acceleration Signal Characteristics for Intuitional Mass Analysis of Metallic Loose Parts

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kwang-Hyun; Jung, Chang-Gyu [KHNP CRI, Daejeon (Korea, Republic of)

    2016-10-15

    Nuclear power plants (NPPs) have operated LPMS (Loose Parts Monitoring System) for early detection of the possible presence of metallic parts in the reactor coolant system (RCS); however, analysis of the metallic impact wave characteristics in the LPMS is an important issue because information, such as the mass of the metallic part and the impact location, is not provided. Most studies have concentrated on fieldwork using the frequency characteristics for the analysis of the metallic part mass. Thus, the field engineers cannot analyze signals without special software and access to the system. This paper is intended to introduce a process of intuitional mass analysis using the attenuation rate of the acceleration signal and the intervals between peak signals. Most studies related to mass analysis of a metallic part impact signal in LPMS have used the frequency spectrum. This paper presents a method of using the acceleration signal characteristics for intuitional mass analysis of loose metallic parts. With the method proposed in this paper, because the mass of a metallic part can be understood intuitionally without any special analysis program, intuitional analysis used in parallel with frequency spectrum analysis will be in effect.

  2. Mass-Discrepancy Acceleration Relation: A Natural Outcome of Galaxy Formation in Cold Dark Matter Halos.

    Science.gov (United States)

    Ludlow, Aaron D; Benítez-Llambay, Alejandro; Schaller, Matthieu; Theuns, Tom; Frenk, Carlos S; Bower, Richard; Schaye, Joop; Crain, Robert A; Navarro, Julio F; Fattahi, Azadeh; Oman, Kyle A

    2017-04-21

    We analyze the total and baryonic acceleration profiles of a set of well-resolved galaxies identified in the eagle suite of hydrodynamic simulations. Our runs start from the same initial conditions but adopt different prescriptions for unresolved stellar and active galactic nuclei feedback, resulting in diverse populations of galaxies by the present day. Some of them reproduce observed galaxy scaling relations, while others do not. However, regardless of the feedback implementation, all of our galaxies follow closely a simple relationship between the total and baryonic acceleration profiles, consistent with recent observations of rotationally supported galaxies. The relation has small scatter: Different feedback implementations-which produce different galaxy populations-mainly shift galaxies along the relation rather than perpendicular to it. Furthermore, galaxies exhibit a characteristic acceleration g_{†}, above which baryons dominate the mass budget, as observed. These observations, consistent with simple modified Newtonian dynamics, can be accommodated within the standard cold dark matter paradigm.

  3. Single-stage accelerator mass spectrometer radiocarbon-interference identification and positive-ionisation characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Wilcken, K.M., E-mail: klaus.wilcken@ansto.gov.au [Scottish Universities Environmental Research Centre, Scottish Enterprise Technology Park, East Kilbride G75 0QF (United Kingdom); Freeman, S.P.H.T.; Xu, S.; Dougans, A. [Scottish Universities Environmental Research Centre, Scottish Enterprise Technology Park, East Kilbride G75 0QF (United Kingdom)

    2013-01-15

    A single-stage accelerator mass spectrometer (SSAMS) is a good alternative to conventional spectrometers based on tandem electrostatic acceleration for radiocarbon measurement and permits experimentation with both negative and positive carbon ions. However, such {sup 14}C AMS of either polarity ions is limited by an interference. In the case of anion acceleration we have newly determined this to be summed {sup 13}C and {sup 16}O by improvising an additional Wien filter on our SSAMS deck. Also, {sup 14}C AMS might be improved by removing its dependency on negative-ionisation in a sputter ion source. This requires negative-ionisation of sample atoms elsewhere to suppress the {sup 14}N interference, which we accomplish by transmitting initially positive ions through a thin membrane. The ionisation dependence on ion-energy is found to be consistent with previous experimentation with vapours and thicker foils.

  4. 15 N utilization in nitride nuclear fuels for advanced nuclear power reactors and accelerator - driven systems

    International Nuclear Information System (INIS)

    Axente, D.

    2005-01-01

    15 N utilization for nitride nuclear fuels production for nuclear power reactors and accelerator - driven systems is presented. Nitride nuclear fuel is the obvious choice for advanced nuclear reactors and ADS because of its favorable properties: a high melting point, excellent thermal conductivity, high fissile density, lower fission gas release and good radiation tolerance. The application of nitride fuels in nuclear reactors and ADS requires use of 15 N enriched nitrogen to suppress 14 C production due to (n,p) reaction on 14 N. Accelerator - driven system is a recent development merging of accelerator and fission reactor technologies to generate electricity and transmute long - lived radioactive wastes as minor actinides: Np, Am, Cm. A high-energy proton beam hitting a heavy metal target produces neutrons by spallation. The neutrons cause fission in the fuel, but unlike in conventional reactors, the fuel is sub-critical and fission ceases when the accelerator is turned off. Nitride fuel is a promising candidate for transmutation in ADS of minor actinides, which are converted into nitrides with 15 N for that purpose. Tacking into account that the world wide market is about 20 to 40 Kg 15 N annually, the supply of that isotope for nitride fuel production for nuclear power reactors and ADS would therefore demand an increase in production capacity by a factor of 1000. For an industrial plant producing 100 t/y 15 N, using present technology of isotopic exchange in NITROX system, the first separation stage of the cascade would be fed with 10M HNO 3 solution of 600 mc/h flow - rate. If conversion of HNO 3 into NO, NO 2 , at the enriching end of the columns, would be done with gaseous SO 2 , for a production plant of 100 t/y 15 N a consumption of 4 million t SO 2 /y and a production of 70 % H 2 SO 4 waste solution of 4.5 million mc/y are estimated. The reconversion of H 2 SO 4 into SO 2 in order to recycle of SO 2 is a problem to be solved to compensate the cost of SO 2

  5. Utilization of Integrated Process Control, Data Capture, and Data Analysis in Construction of Accelerator Systems

    International Nuclear Information System (INIS)

    Bonnie Madre; Charles Reece; Joseph Ozelis; Valerie Bookwalter

    2003-01-01

    Jefferson Lab has developed a web-based system that integrates commercial database, data analysis, document archiving and retrieval, and user interface software, into a coherent knowledge management product (Pansophy). This product provides important tools for the successful pursuit of major projects such as accelerator system development and construction, by offering elements of process and procedure control, data capture and review, and data mining and analysis. After a period of initial development, Pansophy is now being used in Jefferson Lab's SNS superconducting linac construction effort, as a means for structuring and implementing the QA program, for process control and tracking, and for cryomodule test data capture and presentation/analysis. Development of Pansophy is continuing, in particular data queries and analysis functions that are the cornerstone of its utility

  6. Measuring test mass acceleration noise in space-based gravitational wave astronomy

    Science.gov (United States)

    Congedo, Giuseppe

    2015-03-01

    The basic constituent of interferometric gravitational wave detectors—the test-mass-to-test-mass interferometric link—behaves as a differential dynamometer measuring effective differential forces, comprising an integrated measure of gravity curvature, inertial effects, as well as nongravitational spurious forces. This last contribution is going to be characterized by the LISA Pathfinder mission, a technology precursor of future space-borne detectors like eLISA. Changing the perspective from displacement to acceleration can benefit the data analysis of LISA Pathfinder and future detectors. The response in differential acceleration to gravitational waves is derived for a space-based detector's interferometric link. The acceleration formalism can also be integrated into time delay interferometry by building up the unequal-arm Michelson differential acceleration combination. The differential acceleration is nominally insensitive to the system's free evolution dominating the slow displacement dynamics of low-frequency detectors. Working with acceleration also provides an effective way to subtract measured signals acting as systematics, including the actuation forces. Because of the strong similarity with the equations of motion, the optimal subtraction of systematic signals, known within some amplitude and time shift, with the focus on measuring the noise provides an effective way to solve the problem and marginalize over nuisance parameters. The F statistic, in widespread use throughout the gravitation waves community, is included in the method and suitably generalized to marginalize over linear parameters and noise at the same time. The method is applied to LPF simulator data and, thanks to its generality, can also be applied to the data reduction and analysis of future gravitational wave detectors.

  7. Accelerator mass spectrometry-enabled studies: current status and future prospects.

    Science.gov (United States)

    Arjomand, Ali

    2010-03-01

    Accelerator mass spectrometry is a detection platform with exceptional sensitivity compared with other bioanalytical platforms. Accelerator mass spectrometry (AMS) is widely used in archeology for radiocarbon dating applications. Early exploration of the biological and pharmaceutical applications of AMS began in the early 1990s. AMS has since demonstrated unique problem-solving ability in nutrition science, toxicology and pharmacology. AMS has also enabled the development of new applications, such as Phase 0 microdosing. Recent development of AMS-enabled applications has transformed this novelty research instrument to a valuable tool within the pharmaceutical industry. Although there is now greater awareness of AMS technology, recognition and appreciation of the range of AMS-enabled applications is still lacking, including study-design strategies. This review aims to provide further insight into the wide range of AMS-enabled applications. Examples of studies conducted over the past two decades will be presented, as well as prospects for the future of AMS.

  8. Accelerators

    CERN Multimedia

    CERN. Geneva

    2001-01-01

    The talk summarizes the principles of particle acceleration and addresses problems related to storage rings like LEP and LHC. Special emphasis will be given to orbit stability, long term stability of the particle motion, collective effects and synchrotron radiation.

  9. Prospects for experiments on neutrino masses and mixing via neutrino oscillations at future accelerators

    International Nuclear Information System (INIS)

    Lanou, R.E. Jr.

    1982-01-01

    A study is made of the requirements necessary for improvement in our knowledge of limits in mass and mixing parameters for neutrinos via oscillation phenomena at accelerators. It is concluded that increased neutrino event rate (flux x energy) at modest energy machines (e.g., AGS and LAMPF) is the single most important requirement. This will permit smaller E/L ratios and refinement of systematics

  10. Sample preparation for accelerator mass spectrometry at the University of Washington

    International Nuclear Information System (INIS)

    Grootes, P.M.; Stuiver, M.; Farwell, G.W.; Schmidt, F.H.

    1981-01-01

    The adaptation of the University of Washington FN tandem Van de Graaff to accelerator mass spectrometry (AMS), as well as some of the results obtained, are described in another paper in this volume (Farwell et al., 1981). Here we discuss our experiences in preparing carbon and beryllium samples that give large and stable ion beams when used in our Extrion cesium sputter source with an inverted cesium beam geometry

  11. The distributed control system of Shanghai mini-cyclotron accelerator mass spectrometer (SMCAMS)

    International Nuclear Information System (INIS)

    Shao Yuhe

    2001-01-01

    It is mainly introduced the composition, structure, hardware and software designing, function, and the method of communication between the host computer and the ADAM modules of the distributed control system on Shanghai Mini-cyclotron Accelerator Mass Spectrometer (SMCAMS). Some detail problems such as controlling the devices staying on high voltage by ADAM-4541 (RS-485 to Fiber Optic Convertor) and optical fiber are also introduced

  12. An electrostatic beam line for accelerator mass spectroscopy of exotic particles

    International Nuclear Information System (INIS)

    Elmore, D.; Kubik, P.W.; Hemmick, T.; Teng, R.; Kagan, H.; Haas, P.; Boyd, R.N.; Turner, R.; Nitz, D.; Ciampa, D.; Olsen, S.L.; Gentile, T.; Haelen, T.

    1985-01-01

    An all-electrostatic charged particle spectrometer has been constructed to perform high sensitivity searches for exotic states of matter. This spectrometer consists of an electrosatic beam line capable of mass independent charged particle transport and selection together with time-of-flight, energy loss and total energy detectors. This system has been used in conjunction with the tandem electrostatic accelerator at the Nuclear Structure Research Laboratory of the University of Rochester to search for fractionally charged or anomalously heavy particles. (orig.)

  13. An improved method for statistical analysis of raw accelerator mass spectrometry data

    International Nuclear Information System (INIS)

    Gutjahr, A.; Phillips, F.; Kubik, P.W.; Elmore, D.

    1987-01-01

    Hierarchical statistical analysis is an appropriate method for statistical treatment of raw accelerator mass spectrometry (AMS) data. Using Monte Carlo simulations we show that this method yields more accurate estimates of isotope ratios and analytical uncertainty than the generally used propagation of errors approach. The hierarchical analysis is also useful in design of experiments because it can be used to identify sources of variability. 8 refs., 2 figs

  14. Environmental vibration reduction utilizing an array of mass scatterers

    DEFF Research Database (Denmark)

    Peplow, Andrew; Andersen, Lars Vabbersgaard; Bucinskas, Paulius

    2017-01-01

    .g. concrete or stone blocks, specially designed brick walls, etc.). The natural frequencies of vibration for such blocks depend on the local ground stiffness and on the mass of the blocks which can be chosen to provide resonance at specified frequencies. This work concerns the effectiveness of such “blocking......Ground vibration generated by rail and road traffic is a major source of environmental noise and vibration pollution in the low-frequency range. A promising and cost effective mitigation method can be the use of heavy masses placed as a periodic array on the ground surface near the road or track (e...

  15. ANALYSIS OF IMPACT OF CHANGING THE SHOCK ABSORBER RESISTANCE FACTOR ON ACCELERATING THE VEHICLE SPRUNG MASS

    Directory of Open Access Journals (Sweden)

    P. Rozhkov

    2017-12-01

    Full Text Available The change of acceleration of the vehicle sprung mass while changing the coefficient of resistance of the adaptive pendant shock absorber has been analyzed. Presentation of disturbing influence is taken as a harmonic function containing the initial phase. Solution of the system of differential equations is carried out taking into account the initial conditions. The mathematical modeling of the impact of the vehicle sprung mass vibrations at various moments of time of forming the actuating signal on the change of the coefficient of resistance allowed to formulate requirements to the system of adaptive suspension control.

  16. Real time monitoring of accelerated chemical reactions by ultrasonication-assisted spray ionization mass spectrometry.

    Science.gov (United States)

    Lin, Shu-Hsuan; Lo, Ta-Ju; Kuo, Fang-Yin; Chen, Yu-Chie

    2014-01-01

    Ultrasonication has been used to accelerate chemical reactions. It would be ideal if ultrasonication-assisted chemical reactions could be monitored by suitable detection tools such as mass spectrometry in real time. It would be helpful to clarify reaction intermediates/products and to have a better understanding of reaction mechanism. In this work, we developed a system for ultrasonication-assisted spray ionization mass spectrometry (UASI-MS) with an ~1.7 MHz ultrasonic transducer to monitor chemical reactions in real time. We demonstrated that simply depositing a sample solution on the MHz-based ultrasonic transducer, which was placed in front of the orifice of a mass spectrometer, the analyte signals can be readily detected by the mass spectrometer. Singly and multiply charged ions from small and large molecules, respectively, can be observed in the UASI mass spectra. Furthermore, the ultrasonic transducer used in the UASI setup accelerates the chemical reactions while being monitored via UASI-MS. The feasibility of using this approach for real-time acceleration/monitoring of chemical reactions was demonstrated. The reactions of Girard T reagent and hydroxylamine with steroids were used as the model reactions. Upon the deposition of reactant solutions on the ultrasonic transducer, the intermediate/product ions are readily generated and instantaneously monitored using MS within 1 s. Additionally, we also showed the possibility of using this reactive UASI-MS approach to assist the confirmation of trace steroids from complex urine samples by monitoring the generation of the product ions. Copyright © 2014 John Wiley & Sons, Ltd.

  17. Testing the Acceleration Hypothesis: Fluency Outcomes Utilizing Still- versus Accelerated-Text in Sixth-Grade Students with Reading Disabilities

    Science.gov (United States)

    Paige, David D.

    2011-01-01

    The acceleration hypothesis views reading rate simultaneously as both an independent and dependent variable that can be manipulated to encourage increases in reading indicators (Breznitz, 2006). Within this conceptualization, reading rate represents all the component sub-processes required for proficient reading and presents the opportunity for a…

  18. Mass transfer effects in feeder flow-accelerated corrosion wall thinning

    International Nuclear Information System (INIS)

    Pietralik, J.

    2008-01-01

    Flow conditions play a dominant role in Flow-Accelerated Corrosion (FAC) under certain conditions, e.g., in CANDU feeders. While chemistry and materials set the overall potential for FAC, flow conditions determine the local distribution of wall thinning. Recent plant data of feeders and laboratory tests confirms that there is a close relationship between local flow conditions, expressed by mass transfer coefficient, and FAC rate in CANDU feeder bends. The knowledge of local effects can be useful for minimizing the number of inspected components, predicting the location of the highest FAC rate for a given piping component, and determining what components or feeders should be replaced. A similar evaluation applies also to FAC in heat transfer equipment such as heat exchangers and steam generators. The objective of this paper is to examine the relationship between FAC rate and local mass transfer parameters. For FAC where the flow is dominant, the FAC rate is proportional to mass flux of ferrous ions. The mass flux is the product of the mass transfer coefficient and the concentration difference, or degree of saturation. The mass transfer coefficient describes the intensity of the transport of corrosion products (ferrous ions) from the oxide-water interface into the bulk water. Therefore, this parameter can be used for predicting the local distribution of FAC rate in the mass-transfer controlled FAC. The degree of saturation reduces the mass flux, thus reducing the FAC rate. This effect can be significant in long piping, e.g., in outlet feeders. The paper presents plant and laboratory evidence for the relationship between local mass transfer conditions and the FAC rate. It shows correlations for mass transfer coefficient in components that are highly susceptible to FAC and most important flow parameters that affect mass transfer coefficient. The role of surface roughness, wall shear stress, and local turbulence is also discussed. (author)

  19. Preliminary report on the utilization of the Fermilab site for a future accelerator

    International Nuclear Information System (INIS)

    1996-10-01

    This report is a preliminary assessment of the utility of the Fermilab site for future accelerator projects. It responds to a request from the Director to evaluate how the Fermilab site and infrastructure may be relevant to future accelerator projects in the U.S. The SSC experience suggests that any major new project will have to be based on the existing infrastructure at one of the National Laboratories. This work presents only the technical issues and the benefits of the Fermilab site and infrastructure. The projects treated are: (1) A really large hadron collider based on the ''Pipetron'' vision of low-field (2 Tesla) magnets in a small diameter tunnel. Another option, not treated in detail, is a hadron collider using high field magnets. (2) Muon Colliders with 250 GeV and 2 TeV per beam. (3) A linear electron collider with 250 to 500 GeV per beam. The infrastructure of the state of Illinois - geology, hydrology, power and surface water- seems remarkably well suited to any of these projects. The geology of most of Illinois, including Fermilab, contains a dolomite layer that: has low seismic activity, is at an appropriate depth to provide radiation protection, is essentially impervious to water movement and thus satisfies hydrology requirements. There is adequate electrical power - both locally and statewide. We first give brief overviews of the Fermilab and Illinois infrastructure - geology, hydrology, power, and water - and then a summary of each project. On the basis of what we have learned, we feel that Fermilab must be considered seriously as a site for any of these projects. Beyond this point, however site-specific plans will need to be developed for each of the projects

  20. Designing double-gap linear accelerators for a wide mass range

    International Nuclear Information System (INIS)

    Lysenko, W.P.; Wadlinger, E.A.; Rusnak, B.; Krawczyk, F.; Saadatmand, K.; Wan, Z.

    1998-01-01

    For applications like ion implantation, rf linacs using double-gap structures with external resonators can be used because they are practical at low frequencies. However, since the two gaps associated with a given resonator cannot be individually phased, it is not obvious how to build a linac that can efficiently accelerate particles having different mass/charge ratios. This paper describes the beam dynamics of double-gap rf linacs and shows how to maximize the range of mass/charge ratios. The theory also tells one how to rescale a linac tune (i.e., reset the voltages and phases) so that a new particle, having a different mass or charge, will behave similarly to the original particle

  1. Precise isotope analysis. Application of accelerator mass spectrometry to human sample

    International Nuclear Information System (INIS)

    Tokanai, Fuyuki

    2016-01-01

    Isotope 14 C is a radioisotope with a half-life of 5,730 years, and the measurement of its concentration makes it possible to calculate 'carbon 14 age.' This paper introduces up-to-date accelerator mass spectrometry (AMS), which is used in 14 C concentration measurement, and outlines its applied researches in pharmaceutical and medical fields. AMS technique has been applied in Europe and the United States to microdose clinical tests. In Japan, implementation foundation has been ready through the guidelines of the Ministry of Health, Labour and Welfare, five years behind Europe and the United States. Although conventional AMS measurement of 14 C required an acceleration voltage of 3 million volts or more, technological development has enabled a high accuracy of 14 C concentration measurement with the low acceleration voltage of about 400,000 volts. A sample for AMS method is graphitized, transformed to carbon ions ( 12 C-, 13 C-, and 14 C-) through negative ionization with cesium irradiation, accelerated under 450 kV, bombarded with argon gas, charge-converted to 12 C+, 13 C+, and 14 C+, and measured. Biological samples for microdose study are plasma, urine, feces, and biological tissue. Model tests showed a very good linearity between the concentrations of 14 C-containing compounds and 14 C concentrations. Applied research on microdose clinical tests is expected to increase its usability in the future, as an effective means of drug development. (A.O.)

  2. Analysis of trace elements by means of accelerator secondary ion mass spectrometry

    International Nuclear Information System (INIS)

    Ender, R.M.

    1997-01-01

    The analysis of material composition and trace element concentration is of increasing interest primarily in semiconductor technology but also in metallurgy, geology, biology and medicine. At present, Secondary Ion Mass Spectrometry (SIMS) is in many respects the best technique to provide 3-dimensional information on the distribution of trace elements with concentrations below 1 ppm. However, due to the presence of molecular ions the detectability of many trace elements it restricted because of molecular mass interferences. In addition, detectors used in SIMS have a background counting rate of 0.1-1 Hz, which further limits trace element analysis. In Accelerator Mass Spectrometry (AMS) long-lived radionuclides are detected free of molecular interferences and detector background at isotopic ratios as low as 10 -15 . Moreover, isobaric interferences can be reduced as well. In order to benefit from these advantages a combination of SIMS and AMS (Accelerator SIMS) has been proposed almost 20 years ago, but no facility has ever been fully developed. It has been the aim of this work to add a new sputtering chamber for AMS measurements of ultrapure semiconductor material to the existing PSI/ETH AMS facility. To fulfill the requirements of material analysis, an UHV chamber with special precautions against contamination has been built and adapted to the existing AMS setup. For sputtering, a commercial Cs gun with an ExB filter and a 1 o beam bend for neutral particle suppression is used to obtain a pure Cs ion beam. The gun is equipped with different apertures for varying the diameter of the beam spot. With the integrated scanning unit the 10 keV Cs beam can be rastered over approximately 1 mm 2 . This allows different applications such as bulk analysis, depth profiling and imaging. The secondary ion extraction is matched to the ion optical and geometrical requirements of the existing accelerator mass spectrometer. (author) figs., tabs., 67 refs

  3. CologneAMS, a dedicated center for accelerator mass spectrometry in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Dewald, A., E-mail: dewald@ikp.uni-koeln.de [CologneAMS, Institute of Nuclear Physics, University of Cologne (Germany); Heinze, S.; Jolie, J.; Zilges, A. [CologneAMS, Institute of Nuclear Physics, University of Cologne (Germany); Dunai, T.; Rethemeyer, J.; Melles, M.; Staubwasser, M. [Institute of Geology and Mineralogy, University of Cologne (Germany); Kuczewski, B. [Division of Nuclear Chemistry, University of Cologne (Germany); Richter, J. [Institute of Prehistoric Archaeology, University of Cologne (Germany); Radtke, U. [Institute of Geography, University of Cologne, Germany, Rectorate, University of Duisburg-Essen (Germany); Blanckenburg, F. von [GFZ, German Research Centre for Geosciences, Potsdam (Germany); Klein, M. [HVEE, Amersfoort (Netherlands)

    2013-01-15

    CologneAMS is a new centre for accelerator mass spectrometry (AMS) at University of Cologne. It has been funded by the German Research Foundation (DFG) to improve the experimental conditions especially for those German scientists that apply the AMS technique for their geologic, environmental, nuclear chemical, and nuclear astrophysical research. The new AMS-device has been built by High Voltage Engineering Europe (HVEE) and has been installed in the existing accelerator area of the Institute of Nuclear Physics. The AMS-facility is designed for the spectrometry of {sup 10}Be, {sup 14}C, {sup 26}Al, {sup 36}Cl, {sup 41}Ca, {sup 129}I in and heavy ions up to {sup 236}U and {sup 244}Pu. The central part of the AMS-facility is a 6 MV Tandetron Trade-Mark-Sign accelerator. Downstream of the high energy mass spectrometer an additional switching magnet is used as a further filter element which supplies also additional ports for future extensions of the detector systems. The current status of CologneAMS and the results of the first test measurements will be presented.

  4. Utilizing Mass Customization Methods for Modular Manufacturing System Design

    DEFF Research Database (Denmark)

    Jørgensen, Steffen; Jacobsen, Alexia; Nielsen, Kjeld

    2011-01-01

    Markets today have become dynamic and demand rapid product changes, product variety, and customized products. In order to operate under and taking advantages of such conditions requires, amongst other aspects, manufacturing processes robust to product changes - a contradiction to traditional...... manufacturing systems developed as dedicated engineer-to-order solutions, tailored to production of a specific product or a limited product assortment. In response, modular manufacturing concepts are evolving, which are aimed at possessing the needed responsiveness and aimed at being the manufacturing paradigm...... of Mass Customization (MC). Research focus has been on the basic principles and enabling technologies, while modular architectures and system design have received less attention. A potential to fill these gaps by applying selected design theories and methods of MC have been seen. Based on a communality...

  5. Improved detection limit for {sup 59}Ni using the technique of accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Per; Erlandsson, Bengt; Hellborg, Ragnar; Kiisk, Madis; Larsson, Ragnar; Skog, Goeran; Stenstroem, Kristina [Lund Univ. (Sweden). Dept. of Nuclear Physics

    2002-11-01

    59 Ni is produced by neutron activation in the stainless steel close to the core of a nuclear reactor. To be able to classify the different parts of the reactor with respect to their content of long-lived radionuclides before final storage it is important to measure the 59 Ni level. Accelerator mass spectrometry is an ultra-sensitive method for counting atoms, suitable for 59 Ni measurements. Improvements in the reduction of the background and in the chemical reduction of cobalt, the interfering isobar, have been made. This chemical purification is essential when using small tandem accelerators, <3 MV, combined with the detection of characteristic projectile X-rays. These improvements have lowered the detection limit for 59 Ni by a factor of twenty compared with the first value reported for the Lund AMS facility. Material from the Swedish nuclear industry has been analysed and examples of the results are presented.

  6. Design Study of a Mini Cyclotron for the Application of Biomedical Accelerator Mass Spectrometry

    International Nuclear Information System (INIS)

    Kim, Jong-Won; Yun, Chong-Chul; Youn, Min-Yong; Wang, Sonjong

    2009-01-01

    A small cyclotron has been considered for the use of biomedical accelerator mass spectrometer (BAMS). Over a decade ago a few cyclotrons had been constructed and tested for AMS, but technical problems of instability and poor transmission efficiency caused to discontinue further developments. The major reason of the demise of cyclotron AMS was the dominance of commercial Tandem-based AMS facilities. Now BAMS may ask for more compact system, and perhaps using positive ions to accelerate isotope tracers is a favorable feature. The design of a cyclotron to meet the requirements of BAMS has been performed by adopting a compact magnet with high stability and a flat-topping rf system to increase transmission efficiency.

  7. IMPULSIVE ACCELERATION OF CORONAL MASS EJECTIONS. II. RELATION TO SOFT X-RAY FLARES AND FILAMENT ERUPTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Bein, B. M.; Berkebile-Stoiser, S.; Veronig, A. M.; Temmer, M. [Kanzelhoehe Observatory-IGAM, Institute of Physics, University of Graz, Universitaetsplatz 5, A-8010 Graz (Austria); Vrsnak, B. [Hvar Observatory, Faculty of Geodesy, University of Zagreb, Kaciceva 26, HR-10000 Zagreb (Croatia)

    2012-08-10

    Using high time cadence images from the STEREO EUVI, COR1, and COR2 instruments, we derived detailed kinematics of the main acceleration stage for a sample of 95 coronal mass ejections (CMEs) in comparison with associated flares and filament eruptions. We found that CMEs associated with flares reveal on average significantly higher peak accelerations and lower acceleration phase durations, initiation heights, and heights, at which they reach their peak velocities and peak accelerations. This means that CMEs that are associated with flares are characterized by higher and more impulsive accelerations and originate from lower in the corona where the magnetic field is stronger. For CMEs that are associated with filament eruptions we found only for the CME peak acceleration significantly lower values than for events that were not associated with filament eruptions. The flare rise time was found to be positively correlated with the CME acceleration duration and negatively correlated with the CME peak acceleration. For the majority of the events the CME acceleration starts before the flare onset (for 75% of the events) and the CME acceleration ends after the soft X-ray (SXR) peak time (for 77% of the events). In {approx}60% of the events, the time difference between the peak time of the flare SXR flux derivative and the peak time of the CME acceleration is smaller than {+-}5 minutes, which hints at a feedback relationship between the CME acceleration and the energy release in the associated flare due to magnetic reconnection.

  8. Microdroplet fusion mass spectrometry: accelerated kinetics of acid-induced chlorophyll demetallation.

    Science.gov (United States)

    Lee, Jae Kyoo; Nam, Hong Gil; Zare, Richard N

    2017-01-01

    Kinetics of acid-induced chlorophyll demetallation was recorded in microdroplets by fusing a stream of microdroplets containing 40 µM chlorophyll a or b dissolved in methanol with a stream of aqueous microdroplets containing 35 mM hydrochloric acid (pH = 1·46). The kinetics of the demetallation of chlorophyll in the fused microdroplets (14 ± 6 µm diameter; 84 ± 18 m s-1 velocity) was recorded by controlling the traveling distance of the fused microdroplets between the fusion region and the inlet of a mass spectrometer. The rate of acid-induced chlorophyll demetallation was about 960 ± 120 times faster in the charged microdroplets compared with that reported in bulk solution. If no voltage was applied to the sprayed microdroplets, then the acceleration factor was about 580 ± 90, suggesting that the applied voltage is not a major factor determining the acceleration. Chlorophyll a was more rapidly demetallated than chlorophyll b by a factor of ~26 in bulk solution and ~5 in charged microdroplets. The demetallation kinetics was second order in the H+ concentration, but the acceleration factor of microdroplets compared with bulk solution appeared to be unchanged in going from pH = 1·3 to 7·0. The water:methanol ratio of the fused microdroplets was varied from 7:3 to 3:7 causing an increase in the reaction rate of chlorophyll a demetallation by 20%. This observation demonstrates that the solvent composition, which has different evaporation rates, does not significantly affect the acceleration. We believe that a major portion of the acceleration can be attributed to confinement effects involving surface reactions rather than either to evaporation of solvents or to the introduction of charges to the microdroplets.

  9. Accelerator Mass Spectrometry at the National Institute of Nuclear Physics and Engineering in Bucharest

    International Nuclear Information System (INIS)

    Stan-Sion, C.; Catana, D.; Plostinaru, D.; Radulescu, M.; Enachescu, M.; Ivascu, M.; Marinescu, L.; Dima, R.

    2000-01-01

    The Accelerator Mass Spectrometry (AMS) is today the experimental physical method capable to measure the lowest concentration of a particular nuclide in a sample material. Ratios of radionuclides in the range 10 -13 - 10 -15 are normally measured with this technique, corresponding to a sensitivity which makes possible the detection of only 1 Atom in a surrounding material of about 1 Million of Billions of other Atoms. Thus, the AMS has advanced the art of Classical Mass Spectrometry (sensitivity 10 -11 ) to a sensitivity which allows for the first time the performance of special applications in environmental physics, medicine, pharmacology, geology, archaeology, measurements of radio nuclides in the Earth's atmosphere produced by cosmic-rays or by nuclear power plants, applications in astrophysics and in nuclear physics.An Accelerator Mass Spectrometry facility was constructed at the FN - 8 MV tandem accelerator of the National Institute of Physics and Nuclear Engineering . The construction was possible in the frame of a co-operation with the Technical University Munich and with financial support from IAEA-Vienna. It represents the first experimental set-up of this type in the large geographical area of Eastern Europe. The main components of the facility are: the ion injector deck, the AMS beam line and the detector systems. The injector deck is polarized at 50 kV and contains the high current sputtering ion source (spherical ionizer) followed, for beam transport, by electrostatic devices (single lenses, steerers, quadrupole lenses) a double focussing, 90 angle analyzing magnet (Danfysik), a pre-acceleration tube (NEC) and several diagnose and defining elements. The AMS samples are placed in an eight-stack magazine attached to the ion source. On the exit side of the tandem accelerator tank, a velocity filter and the particle detection system are mounted. The beam line, on the high-energy side, is optically achromatic and contains two 90 angle analyzing magnets of

  10. Design of the hydraulic shock absorbers characteristics using the acceleration of the sprung mass

    Directory of Open Access Journals (Sweden)

    Polach P.

    2007-10-01

    Full Text Available The force-velocity characteristics of the air-pressure-controlled shock absorbers produced in BRANO a.s. were designed on the basis of the relative deflections of the air springs. These characteristics are verified by means of another approach – the acceleration of the sprung mass criterion. The reference vehicle is the same as in the previous case – the SOR C 12 intercity bus. The bus multibody models created in the alaska simulation tool are used for the designed characteristics verification. The results of both approaches are compared.

  11. IAEA meeting on accelerator mass spectrometry, Zagreb, Croatia, April 19-21, 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    Accelerator Mass Spectrometry (AMS) has developed into a major analytical tool for the measurement of ultra-low-level long-lived radionuclides. It is of paramount importance to promote the use of AMS within the IAEA. This would be particularly beneficial for the following IAEA programs: Safeguards, Physical and chemical sciences, Human health, Food and agriculture, Radioactive waste management, Radiation safety, Industry and earth sciences. The IAEA is working in the area of development of reference materials, interlaboratory comparisons and quality assurance. This meeting recommends that this program further developed and extended to include all the AMS isotopes.

  12. IAEA meeting on accelerator mass spectrometry, Zagreb, Croatia, April 19-21, 1995

    International Nuclear Information System (INIS)

    1995-01-01

    Accelerator Mass Spectrometry (AMS) has developed into a major analytical tool for the measurement of ultra-low-level long-lived radionuclides. It is of paramount importance to promote the use of AMS within the IAEA. This would be particularly beneficial for the following IAEA programs: Safeguards, Physical and chemical sciences, Human health, Food and agriculture, Radioactive waste management, Radiation safety, Industry and earth sciences. The IAEA is working in the area of development of reference materials, interlaboratory comparisons and quality assurance. This meeting recommends that this program further developed and extended to include all the AMS isotopes

  13. Dating of two human fossil bones from Romania by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Olariu, Agata; Skog, Goeran; Hellborg, Ragnar; Stenstroem, Kristina; Faarinen, Mikko; Persson, Per; Alexandrescu, Emilian

    2005-01-01

    In this study we have dated two fossil remains found in Romania, by the method of radiocarbon using the technique of the accelerator mass spectrometry. The human fossil remains from Woman's cave, Baia de Fier, have been dated to the age 30150 ± 800 years BP, and the skull, from the Cioclovina cave has been dated to the age 29000 ± 700 years BP. These are among the most ancient dated human fossil remains from Romania, possibly belonging to the upper Paleolithic, the Aurignacian period. (authors)

  14. Discretization of space and time: mass-energy relation, accelerating expansion of the Universe, Hubble constant

    OpenAIRE

    Roatta , Luca

    2017-01-01

    Assuming that space and time can only have discrete values, we obtain the expression of the gravitational potential energy that at large distance coincides with the Newtonian. In very precise circumstances it coincides with the relativistic mass-energy relation: this shows that the Universe is a black hole in which all bodies are subjected to an acceleration toward the border of the Universe itself. Since the Universe is a black hole with a fixed radius, we can obtain the density of the Unive...

  15. Toward Understanding the Early Stags of an Impulsively Accelerated Coronal Mass Ejection

    Science.gov (United States)

    2010-08-09

    B. E., & Howard, R. A . 2009, ApJ, 702, 901 Wood, B. E., Karovska , M., Chen, J., Brueckner, G. E., Cook, J. W., & Howard, R. A . 1999, ApJ, 512, 484...ar X iv :1 00 8. 11 71 v1 [ as tr o- ph .S R ] 6 A ug 2 01 0 Astronomy & Astrophysics manuscript no. bubble c© ESO 2010 August 9, 2010 Toward...understanding the early stages of an impulsively accelerated coronal mass ejection SECCHI observations S. Patsourakos1, A . Vourlidas2, and B. Kliem3,4

  16. Accelerated ice-sheet mass loss in Antarctica from 18-year satellite laser ranging measurements

    Directory of Open Access Journals (Sweden)

    Shuanggen Jin

    2016-02-01

    Full Text Available Accurate estimate of the ice-sheet mass balance in Antarctic is very difficult due to complex ice sheet condition and sparse in situ measurements. In this paper, the low-degree gravity field coefficients of up to degree and order 5 derived from Satellite Laser Ranging (SLR measurements are used to determine the ice mass variations in Antarctica for the period 1993–2011. Results show that the ice mass is losing with -36±13 Gt/y in Antarctica, -42±11 Gt/y in the West Antarctica and 6±10 Gt/y in the East Antarctica from 1993 to 2011. The ice mass variations from the SLR 5×5 have a good agreement with the GRACE 5×5, GRACE 5×5 (1&2 and GRACE (60×60 for the entire continent since 2003, but degree 5 from SLR is not sufficient to quantify ice losses in West and East Antarctica, respectively. The rate of ice loss in Antarctica is -28±17 Gt/y for 1993-2002 and -55±17 Gt/y for 2003-2011, indicating significant accelerated ice mass losses since 2003. Furthermore, the results from SLR are comparable with GRACE measurements.

  17. Techniques of tandem accelerator mass spectrometry and their applications to 14C measurements

    International Nuclear Information System (INIS)

    Nakamura, Toshio; Nakai, Nobuyuki; Furukawa, Michiaki

    1990-01-01

    A tandem accelerator mass spectrometer, named Tandetron was installed at Nagoya University in 1982 for 14 C measurement. The Tandetron spectrometer consists of a Cs sputter ion source to produce negative carbon ions, a Schenkel-type 2.2 MV tandem accelerator, an ion-beam analyzing apparatus with a charge-energy selector and mass spectrometer, and a heavy ion detector to identify and count 14 C 3+ ions from various background ions. The 14 C concentrations in pine needles, sampled at the Higashiyama Campus of Nagoya University, have been measured since 1984. The present article describes some of the measurements of 14 C in pine needles, focusing on the annual changes in the Δ 14 C value of atmospheric CO 2 , and on the effect upon 14 C concentrations for pine needles of a local 14 CO 2 emission from incineration of radioactive organic solvent wastes containing 14 C, at the Radioisotope Center in the Higashiyama Campus. The pine needles at some locations seemed to be influenced by local artificial CO 2 emission. The Δ 14 C values increased noticeably from 1956 to 1964 as a result of artificial 14 C produced in nuclear weapon tests. (N.K.)

  18. Radiocarbon dating of lake sediments and peats by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Fowler, A.J.

    1985-01-01

    The small sample size requirement of accelerator mass spectrometry has allowed the measurement of the 14C/12C ratio for components of various lake sediment and peat samples, with a view to gaining greater understanding of sedimentary processes and to overcome some of the problems associated with conventional radiocarbon dating of sediments, where the 14C/12C ratio of the whole sample, less carbonate, is measured. Some of the fractions of sedimentary organic matter are amenable to analysis. Different molecules are specific to higher plants, algae and bacteria, so estimates of the major sources of input to the sediment can be made. The lipid fraction, though a small component (1%) of the total organic matter, yields most source information. Analyses of n-fatty acids and n-alkanes by capillary gas chromatography are used to interpret the radiocarbon result for the total crude lipid samples in the light of the environmental information so gained. Comparison of the various radiocarbon results for different components of the sediment has provided evidence for the importance of the amount of organic carbon in the samples, microbial attack during storage, the presence of mineral carbon, mixing, hard-water effects and the influence of terrestrial material on lake sediments. A regime has been proposed for the routine preparation of samples at an accelerator mass spectrometry facility in order to provide maximum useful information on a sediment sample. (author)

  19. Performance report for the low energy compact radiocarbon accelerator mass spectrometer at Uppsala University

    Energy Technology Data Exchange (ETDEWEB)

    Salehpour, M., E-mail: mehran.salehpour@physics.uu.se [Department of Physics and Astronomy, Ion Physics, Applied Nuclear Physics Division, P.O. Box 516, SE-751 20 Uppsala (Sweden); Håkansson, K.; Possnert, G. [Department of Physics and Astronomy, Ion Physics, Applied Nuclear Physics Division, P.O. Box 516, SE-751 20 Uppsala (Sweden); Wacker, L.; Synal, H.-A. [Ion Physics, ETH Zurich, Otto-Stern-Weg 5, 8093 (Switzerland)

    2016-03-15

    A range of ion beam analysis activities are ongoing at Uppsala University, including Accelerator Mass Spectrometry (AMS). Various isotopes are used for AMS but the isotope with the widest variety of applications is radiocarbon. Up until recently, only the 5 MV Pelletron tandem accelerator had been used at our site for radiocarbon AMS, ordinarily using 12 MeV {sup 14,13,12}C{sup 3+} ions. Recently a new radiocarbon AMS system, the Green-MICADAS, developed at the ion physics group at ETH Zurich, was installed. The system has a number of outstanding features which will be described. The system operates at a terminal voltage of 175 kV and uses helium stripper gas, extracting singly charged carbon ions. The low- and high energy mass spectrometers in the system are stigmatic dipole permanent magnets (0.42 and 0.97 T) requiring no electrical power nor cooling water. The system measures both the {sup 14}C/{sup 12}C and the {sup 13}C/{sup 12}C ratios on-line. Performance of the system is presented for both standard mg samples as well as μg-sized samples.

  20. Performance report for the low energy compact radiocarbon accelerator mass spectrometer at Uppsala University

    Science.gov (United States)

    Salehpour, M.; Håkansson, K.; Possnert, G.; Wacker, L.; Synal, H.-A.

    2016-03-01

    A range of ion beam analysis activities are ongoing at Uppsala University, including Accelerator Mass Spectrometry (AMS). Various isotopes are used for AMS but the isotope with the widest variety of applications is radiocarbon. Up until recently, only the 5 MV Pelletron tandem accelerator had been used at our site for radiocarbon AMS, ordinarily using 12 MeV 14,13,12C3+ ions. Recently a new radiocarbon AMS system, the Green-MICADAS, developed at the ion physics group at ETH Zurich, was installed. The system has a number of outstanding features which will be described. The system operates at a terminal voltage of 175 kV and uses helium stripper gas, extracting singly charged carbon ions. The low- and high energy mass spectrometers in the system are stigmatic dipole permanent magnets (0.42 and 0.97 T) requiring no electrical power nor cooling water. The system measures both the 14C/12C and the 13C/12C ratios on-line. Performance of the system is presented for both standard mg samples as well as μg-sized samples.

  1. Biomedical applications of accelerator mass spectrometry-isotope measurements at the level of the atom.

    Science.gov (United States)

    Barker, J; Garner, R C

    1999-01-01

    Accelerator mass spectrometry (AMS) is a nuclear physics technique developed about twenty years ago, that uses the high energy (several MeV) of a tandem Van de Graaff accelerator to measure very small quantities of rare and long-lived isotopes. Elements that are of interest in biomedicine and environmental sciences can be measured, often to parts per quadrillion sensitivity, i.e. zeptomole to attomole levels (10(-21)-10(-18) mole) from milligram samples. This is several orders of magnitude lower than that achievable by conventional decay counting techniques, such as liquid scintillation counting (LSC). AMS was first applied to geochemical, climatological and archaeological areas, such as for radiocarbon dating (Shroud of Turin), but more recently this technology has been used for bioanalytical applications. In this sphere, most work has been conducted using aluminium, calcium and carbon isotopes. The latter is of special interest in drug metabolism studies, where a Phase 1 adsorption, distribution, metabolism and excretion (ADME) study can be conducted using only 10 nanoCurie (37 Bq or ca. 0.9 microSv) amounts or less of 14C-labelled drugs. In the UK, these amounts of radioactivity are below those necessary to request specific regulatory approval from the Department of Health's Administration of Radioactive Substances Advisory Committee (ARSAC), thus saving on valuable development time and resources. In addition, the disposal of these amounts is much less an environmental issue than that associated with microCurie quantities, which are currently used. Also, AMS should bring an opportunity to conduct "first into man" studies without the need for widespread use of animals. Centre for Biomedical Accelerator Mass Spectrometry (CBAMS) Ltd. is the first fully commercial company in the world to offer analytical services using AMS. With its high throughput and relatively low costs per sample analysis, AMS should be of great benefit to the pharmaceutical and biotechnology

  2. Mass

    International Nuclear Information System (INIS)

    Quigg, Chris

    2007-01-01

    In the classical physics we inherited from Isaac Newton, mass does not arise, it simply is. The mass of a classical object is the sum of the masses of its parts. Albert Einstein showed that the mass of a body is a measure of its energy content, inviting us to consider the origins of mass. The protons we accelerate at Fermilab are prime examples of Einsteinian matter: nearly all of their mass arises from stored energy. Missing mass led to the discovery of the noble gases, and a new form of missing mass leads us to the notion of dark matter. Starting with a brief guided tour of the meanings of mass, the colloquium will explore the multiple origins of mass. We will see how far we have come toward understanding mass, and survey the issues that guide our research today.

  3. Annual report of Department of Research Reactors and Tandem Accelerator, JFY2006. Operation, utilization and technical development of JRR-3, JRR-4, NSRR and Tandem Accelerator

    International Nuclear Information System (INIS)

    2007-12-01

    The Department of Research Reactors and Tandem Accelerator is in charge of the operation, utilization and technical development of JRR-3 (Japan Research Reactor-3), JRR-4 (Japan Research Reactor-4) and NSRR (Nuclear Safety Research Reactor) and Tandem Accelerator. The following services and technical developments were achieved in Japanese Fiscal Year 2006: 1) JRR-3 was operated for 181 days in 7 cycles and JRR-4 for 149 days in 37 cycles to provide neutrons for research and development of in-house and outside users. 2) JRR-3 and JRR-4 were utilized through deliberate coordination as follows, a) Neutron irradiations of 628 materials, for neutron transmutation doping of silicon etc. b) Capsule irradiations of 3,067 samples, for neutron activation analyses etc. c) Neutron beam experiments of 6,338 cases x days. 3) Concerning to the 10 times increasing plan of cold neutron beams from JRR-3, a pressure resistant test model of the high-performance neutron moderator vessel which had been designed to increase cold neutrons twice as much as the present one was fabricated. Various developments for upgrading cold neutron guide tubes with super mirrors were in progress. 4) Boron neutron capture therapy was carried out 34 times using JRR-4. Improved neutron collimators were built to fit well to any irregular outline for cancer around the neck. 5) NSRR carried out 4 times of pulse irradiations of high burn-up MOX fuels and 9 times of un-irradiated fuels to contribute to fuel safety researches. 6) The Tandem Accelerator was operated for 201 days to contribute to the researches of nuclear physics and solid state physics with high energy heavy ions. The new utilization program of sharing beam times with outside users was performed by carrying out 45 days. The beam intensity increasing program with a high performance ion source, in place of the compact one which has been working in the high voltage terminal, has made great progress. (author)

  4. Flow and mass transfer downstream of an orifice under flow accelerated corrosion conditions

    International Nuclear Information System (INIS)

    Ahmed, Wael H.; Bello, Mufatiu M.; El Nakla, Meamer; Al Sarkhi, Abdelsalam

    2012-01-01

    Highlights: ► Mass transfer downstream of orifices was numerically and experimentally investigated. ► The surface wear pattern is measured and used to validate the present numerical results. ► The maximum mass transfer coefficient found to occur at approximately 2–3 pipe diameters downstream of the orifice. ► The FAC wear rates were correlated with the turbulence kinetic energy and wall mass transfer in terms of Sherwood number. ► The current study offered very useful information for FAC engineers for better preparation of nuclear plant inspection scope. - Abstract: Local flow parameters play an important role in characterizing flow accelerated corrosion (FAC) downstream of sudden area change in power plant piping systems. Accurate prediction of the highest FAC wear rate locations enables the mitigation of sudden and catastrophic failures, and the improvement of the plant capacity factor. The objective of the present study is to evaluate the effect of the local flow and mass transfer parameters on flow accelerated corrosion downstream of an orifice. In the present study, orifice to pipe diameter ratios of 0.25, 0.5 and 0.74 were investigated numerically by solving the continuity and momentum equations at Reynolds number of Re = 20,000. Laboratory experiments, using test sections made of hydrocal (CaSO 4 ·½H 2 O) were carried out in order to determine the surface wear pattern and validate the present numerical results. The numerical results were compared to the plants data as well as to the present experiments. The maximum mass transfer coefficient found to occur at approximately 2–3 pipe diameters downstream of the orifice. This location was also found to correspond to the location of elevated turbulent kinetic energy generated within the flow separation vortices downstream of the orifice. The FAC wear rates were correlated with the turbulence kinetic energy and wall mass transfer in terms of Sherwood number. The current study found to offer very

  5. Accelerator mass spectrometry and the prehistoric occupation of the coast of rio de janeiro - brazil

    International Nuclear Information System (INIS)

    Damasio Macario, K.; Anjos, R.M.; Gomes, P.R.S.; Facure, A.D.; Elmore, M.; Coimbra, M.; Padron, I.; Najjar, R.; Kneip, L.; Lima, T.A.; Buarque, A.; Barbosa, M.; Seda, P.

    2001-01-01

    The Accelerator Mass Spectrometry (AMS) technique is a very attractive method for mass spectrometry, since it allows determination of concentrations with sensitivity down to 1 atom of isotope in 1015 atoms, using few milligrams samples. A Tandem accelerator is used as a magnetic and electrostatic analyzer. The determination of these extremely low concentrations of rare isotopes, accelerated to the MeV range, is measured by the direct counting of the atoms by nuclear detection techniques. The AMS technique has been implemented recently in Brazil, at the Pelletron 8UD Tandem accelerator (Sao Paulo), following many improvements on the ion source, VGM control, machine parameters control and detection system. In this contribution we report an important application on AMS on archaeological studies, performed at the Prime Lab (USA), on the dating of ceramics, bones, charcoals, nuts and shells samples of the of the coast of Rio de Janeiro. The main objective of this work is to improve the present knowledge on the occupation of Brazil by the Indians in the prehistoric period, studying archaeological sites located in Rio de Janeiro. Studies show that the Brazilian coast was first occupied in the beginning of the Holocene, with the settlements of the collectors of mollusk, builders of shell mounds, called S ambaquis . The word is of Tupi etymology, tamba meaning shellfish and ki to pile up. The Tupi were a horticultural/potter group who used to live on the Brazilian coast at the time of the European arrivals; they coined the term that describes the main characteristic of the sites - the accumulation of great quantities of mollusk shells. One of objectives of this research is to understand those societies functioning structure, spatial ordering, interaction in the environment and their transformation processes, from the study of their remains. It is intended to analyze the region occupation process dynamics and search for possible links between the pre-pottery population socio

  6. Annual report of Department of Research Reactor and Tandem Accelerator, JFY2012. Operation, utilization and technical development of JRR-3, JRR-4, NSRR, Tandem Accelerator and RI Production Facility

    International Nuclear Information System (INIS)

    Murayama, Yoji; Ishii, Tetsuro; Nakamura, Kiyoshi; Uno, Yuki; Ishikuro, Yasuhiro; Kawashima, Kazuhito; Ishizaki, Nobuhiro; Matsumura, Taichi; Nagahori, Kazuhisa; Odauchi, Shouji; Maruo, Takeshi

    2014-03-01

    The Department of Research Reactor and Tandem Accelerator is in charge of the operation, utilization and technical development of JRR-3(Japan Research Reactor No.3), JRR-4(Japan Research Reactor No.4), NSRR(Nuclear Safety Research Reactor), Tandem Accelerator and RI Production Facility. This annual report describes a summary of activities of services and technical developments carried out in the period between April 1, 2012 and March 31, 2013. The activities were categorized into five service/development fields: (1) Operation and maintenance of research reactors and tandem accelerator, (2) Utilization of research reactors and tandem accelerator, (3) Upgrading of utilization techniques of research reactors and tandem accelerator, (4) Safety administration for department of research reactor and tandem accelerator, (5) International cooperation. Also contained are lists of publications, meetings, granted permissions on laws and regulations concerning atomic energy, number of staff members dispatched to Fukushima for the technical assistance, outcomes in service and technical developments and so on. (author)

  7. Fluoride sample matrices and reaction cells — new capabilities for isotope measurements in accelerator mass spectrometry

    Directory of Open Access Journals (Sweden)

    Eliades J.

    2012-04-01

    Full Text Available Two new techniques, which extend the range of elements that can be analyzed by Accelerator Mass Spectrometry (AMS, and which increase its isobar selection capabilities, have been recently introduced. The first consists of embedding the sample material in a fluoride matrix (e.g. PbF2, which facilitates the production, in the ion source, of fluoride molecular anions that include the isotope of interest. In addition to forming anions with large electron binding energies and thereby increasing the range of analysable elements, in many cases by selection of a molecular form with a particular number of fluorine atoms, some isobar discrimination can be obtained. The second technique, for the significant reduction of atomic isobar interferences, is used following mass selection of the rare isotope. It consists of the deceleration, cooling and reaction of the rare mass beam with a gas, selected so that unwanted isobars are greatly attenuated in comparison with the isotope of interest. Proof of principle measurements for the analysis of 36C1 and 41Ca have provided encouraging results and work is proceeding on the integration of these techniques in a new AMS system planned for installation in late 2012 at the University of Ottawa.

  8. International topical meeting on nuclear research applications and utilization of accelerators. Book of abstracts

    International Nuclear Information System (INIS)

    2009-01-01

    Applications of particle accelerators cover a number of areas, from strategic and applied research, safety and security, environmental applications, materials research and analytical sciences, to radioisotope production and radiation processing. Accelerator based techniques and pulsed neutron sources are expected to lead to new initiatives in materials research of relevance for both the nuclear and non-nuclear fields. Material science studies with the use of accelerators, neutron beams and other nuclear analytical methods are relevant to the development of advanced reactors, nuclear fuel cycle needs and fusion research. In this regard, a better understanding of the irradiation effects in materials for energy and non-energy applications is needed, and is reflected in accelerator techniques for modification and analysis of materials for nuclear technologies. Accelerator applications for innovative nuclear systems aiming at rad-waste transmutation (e.g., accelerator driven systems) are being pursued in many countries. Research and development using accelerators involves a broad spectrum of skills to build a cadre of trained experts in nuclear techniques in IAEA Member States, and to generate knowledge for innovative methodologies and tools. The present conference is also being held in cooperation with the American Nuclear Society (ANS), which successfully organized the series of accelerator applications conferences known as AccApp. The ANS series of topical meetings has provided a forum for the global exchange of scientific and technical knowledge on a wide variety of related topics since the first AccApp took place in 1997 in Albuquerque, USA. The last conference which was held in 2007 in Pocatello, USA, was jointly organized by the ANS and the IAEA. The main objectives of the conference are to promote exchange of information among IAEA Member States representatives/delegates and to discuss new trends in accelerator applications including nuclear materials research

  9. Dating of two paleolithic human fossils from Romania by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Olariu, Agata; Alexandrescu, Emilian; Skog, Goeran; Hellborg, Ragnar; Stenstroem, Kristina; Faarinen, Mikko; Persson, Per

    2003-01-01

    In this study, we have dated two human fossil remains from Romania by the method of radiocarbon using the technique of the accelerator mass spectrometry at the Pelletron system of Lund University, Sweden. Two fossil remains appear to be the most ancient human remains ever dated in our country: 1. A skull, a scapula and a tibia found in Baia de Fier in the Women's Cave, in Gorj county in the province Oltenia, by Constantin Nicolaescu-Plopsor in 1952; 2. A skull found in Cioclovina cave, near commune Bosorod, Hunedoara county in Transilvania by a worker at the exploitation of phosphate deposits in the year 1941. The skull was examined by Francisc Rainer, anthropologist, and Ioan Simionescu, geologist, who published a study. The lack of stratigraphic observations made very difficult the cultural and chronological assignments of this skull. These authors advanced the hypothesis that the skull belongs to the man of the type Homo sapiens fossilis. At the same time, a number of archaeologists believed that the skull might belong to a modern man, but there have been doubts about this matter. Under this circumstance, dating of the two skulls by physical analysis methods appears to be decisive. Samples of bone were taken from the scapula and tibia from Woman's cave, Baia de Fier and from the skull from Cioclovina cave. The content of Carbon 14 have been determined in the two samples by using the technique of accelerator mass spectrometry (AMS), performed at the AMS system of Lund University, in Sweden. Usually, the collagen amount sufficient for AMS measurements can be extracted from bone fragments with masses of 1 g or more (what provides 5 to 10% of the original collagen content). But, in the situation of the present studied fossil remains, because of the small quantity of bone samples and because the bones were very old, the determination of radiocarbon in the skulls was not so simple. For the preparation of the bone samples, we have essentially applied the Longin method

  10. Effective Acceleration Model for the Arrival Time of Interplanetary Shocks driven by Coronal Mass Ejections

    Science.gov (United States)

    Paouris, Evangelos; Mavromichalaki, Helen

    2017-12-01

    In a previous work (Paouris and Mavromichalaki in Solar Phys. 292, 30, 2017), we presented a total of 266 interplanetary coronal mass ejections (ICMEs) with as much information as possible. We developed a new empirical model for estimating the acceleration of these events in the interplanetary medium from this analysis. In this work, we present a new approach on the effective acceleration model (EAM) for predicting the arrival time of the shock that preceds a CME, using data of a total of 214 ICMEs. For the first time, the projection effects of the linear speed of CMEs are taken into account in this empirical model, which significantly improves the prediction of the arrival time of the shock. In particular, the mean value of the time difference between the observed time of the shock and the predicted time was equal to +3.03 hours with a mean absolute error (MAE) of 18.58 hours and a root mean squared error (RMSE) of 22.47 hours. After the improvement of this model, the mean value of the time difference is decreased to -0.28 hours with an MAE of 17.65 hours and an RMSE of 21.55 hours. This improved version was applied to a set of three recent Earth-directed CMEs reported in May, June, and July of 2017, and we compare our results with the values predicted by other related models.

  11. Plans for laser ablation of actinides into an ECRIS for accelerator mass spectroscopy

    International Nuclear Information System (INIS)

    Pardo, R.C.; Kondev, F.G.; Kondrashev, S.; Nair, C.; Palchan, T.; Rehm, E.; Scott, R.; Vondrasek, R.; Paul, M.; Collon, P.; Youinou, G.; Salvatores, M.; Palmotti, G.; McGrath, C.; Imel, G.

    2012-01-01

    A project using Accelerator Mass Spectrometry (AMS) at the ATLAS facility to measure neutron capture rates on a wide range of actinides in a reactor environment is underway. This project will require the measurement of many samples with high precision and accuracy. The AMS technique at ATLAS is based on production of highly-charged positive ions in an electron cyclotron resonance ion source (ECRIS) followed by linear acceleration. We have chosen to use laser ablation as the best means of feeding the actinide material into the ion source because we believe this technique will have more efficiency and lower chamber contamination thus reducing 'cross talk' between samples. In addition construction of a new multi-sample holder/changer to allow quick change between multiple samples is part of the project. The status of the project, design, and goals for initial offline ablation tests will be discussed as well as the overall project schedule. The paper is followed by the associated poster. (authors)

  12. Current perspectives of 14C-isotope measurement in biomedical accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Lappin, Graham; Garner, R.Colin

    2004-01-01

    Accelerator mass spectrometry (AMS) is an extremely sensitive nuclear physics technique developed in the mid-70's for radiocarbon dating of historical artefacts. The technique centres round the use of a tandem Van de Graaff accelerator to generate the potential energy to permit separation of elemental isotopes at the single atom level. AMS was first used in the early 90's for the analysis of biological samples containing enriched 14 C for toxicology and cancer research. Since that time biomedical AMS has been used in the study of (1) metabolism of xenobiotics in animals and humans (2) pathways of drug metabolism (3) biomarkers (4) metabolism of endogenous molecules including vitamins (5) DNA and protein binding studies and (6) clinical diagnosis. A new drug development concept which relies on the ultrasensitivity of AMS known as human microdosing (Phase 0) is being used to obtain early human metabolism information of candidate drugs arising out of discovery. These various aspects of AMS are reviewed in this article and a perspective on future applications of AMS provided. (orig.)

  13. Current perspectives of 14C-isotope measurement in biomedical accelerator mass spectrometry.

    Science.gov (United States)

    Lappin, Graham; Garner, R Colin

    2004-01-01

    Accelerator mass spectrometry (AMS) is an extremely sensitive nuclear physics technique developed in the mid-70's for radiocarbon dating of historical artefacts. The technique centres round the use of a tandem Van de Graaff accelerator to generate the potential energy to permit separation of elemental isotopes at the single atom level. AMS was first used in the early 90's for the analysis of biological samples containing enriched 14C for toxicology and cancer research. Since that time biomedical AMS has been used in the study of (1) metabolism of xenobiotics in animals and humans (2) pathways of drug metabolism (3) biomarkers (4) metabolism of endogenous molecules including vitamins (5) DNA and protein binding studies and (6) clinical diagnosis. A new drug development concept which relies on the ultrasensitivity of AMS known as human microdosing (Phase 0) is being used to obtain early human metabolism information of candidate drugs arising out of discovery. These various aspects of AMS are reviewed in this article and a perspective on future applications of AMS provided.

  14. Application of tandem accelerator mass spectrometor to the chronological study of archaeological samples on Ryukyu Islands

    International Nuclear Information System (INIS)

    Taira, Hatsuo; Higa, Kenichi; Nakai, Nobuyuki; Nakamura, Toshio.

    1987-01-01

    Along with the urbanization of rural areas on Ryukyu Islands, many shell mounds and pre-historic sites have been found in resent years. Chrological studies of shell samples from these mounds will lead to the better understanding of cultural background for the pre-historic human activities on the Ryukyu Islands. C-14 dating by beta counting is the common method to obtain the ages of the archaeological samples. It is, however, very limitted in obtaining the absolute ages by the above mehtod due to the large sample sizes required and time consuming. There are many newly obtained archaeological samples left unstudied in detail. The alternate is a method called Tandem Accelerator Mass Spectrometer (AMS) installed at Nagoya University, which is composed of the tandem type accelerator to measure very low concentration of C-14 in archaeological samples. The system has been designed particularly to measure the radio-carbon and has advantages of being small sample size and very little time consuming for C-14 measurement as compared with the beta counting. It is the aim of this work to apply the above AMS for obtaining the absolute ages of the archaeological samples. The results agreed well with those estimated by the Erthenware method (relative method of dating), which ranged from 500 to 6000 y.b.p. The results may be helpful for the chronological arrangement of the samples and for the understanding of pre-historical human activities on the Ryukyu Islands. (author)

  15. A dedicated AMS setup for medium mass isotopes at the Cologne FN tandem accelerator

    Science.gov (United States)

    Schiffer, M.; Altenkirch, R.; Feuerstein, C.; Müller-Gatermann, C.; Hackenberg, G.; Herb, S.; Bhandari, P.; Heinze, S.; Stolz, A.; Dewald, A.

    2017-09-01

    AMS measurements of medium mass isotopes, e.g. of 53Mn and 60Fe, are gaining interest in various fields of operation, especially geoscience. Therefore a dedicated AMS setup has been built at the Cologne 10 MV FN tandem accelerator. This setup is designed to obtain a sufficient suppression of the stable isobars at energies around 100 MeV. In this contribution we report on the actual status of the new setup and the first in-beam tests of its individual components. The isobar suppression is done with (dE/dx) techniques using combinations of energy degrader foils with an electrostatic analyzer (ESA) and a time of flight (ToF) system, as well as a (dE/dx),E gas ionization detector. Furthermore, the upgraded ion source and its negative ion yield measurement for MnO- are presented.

  16. Accelerator mass spectrometry at Arizona: geochronology of the climate record and connections with the ocean

    International Nuclear Information System (INIS)

    Jull, A.J.T.; Burr, G.S.; Beck, J.W.; Donahue, D.J.; Biddulph, D.; Hatheway, A.L.; Lange, T.E.; McHargue, L.R.

    2003-01-01

    There are many diverse uses of accelerator mass spectrometry (AMS). Carbon-14 studies at our laboratory include much research related to paleoclimate, both with 14 C as a tracer of past changes in environmental conditions as observed in corals, marine sediments and many terrestrial records. Terrestrial records such as forest fires can also show the influence of oceanic oscillations, whether they are short-term such as ENSO, or on the millennial time scale. In tracer applications, we have developed the use of 129 I as well as 14 C as tracers for nuclear pollution studies around radioactive waste dump sites, in collaboration with IAEA. We discuss some applications carried out in Tucson for several of these fields and hope to give some idea of the breadth of these studies

  17. "1"4C ages and calendar years of Japanese swords measured with accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Nagata, Kazuhiro; Matsubara, Akihiro; Kokubu, Yoko; Nakamura, Toshio

    2016-01-01

    Steel of Japanese swords has been produced with Tatara process from iron sand and charcoal. Carbon dissolved in steel was absorbed from wooden charcoal fuel during the production of the steel. From the decay of "1"4C activity in the steel, the "1"4C age of Japanese sword can be determined. The "1"4C ages of 4 Japanese swords were measured with accelerator mass spectrometry and calibrated to calendar years. Each "1"4C age provided plural calendar year periods with definite probabilities, and one of the periods agreed with the production year of each sword that was determined from the sword master's name cut in the grip of his sword after taking the age range of charcoal used for steel production and usage for several generations of the same names of sword masters into account. (author)

  18. Radiocarbon dating study of ancient iron artifacts with accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Igaki, Kenzo; Nakamura, Toshio; Hirasawa, Masahiro; Kato, Masako; Sano, Masamichi.

    1994-01-01

    In order to study the correlation between the highly resistive property against corrosion and the production method of the ancient iron artifacts, it is essentially necessary to determine the accurate ages of them. 14 C dating with accelerator mass spectrometry was applied to the two ancient artifacts, a Japanese sword of wrought iron with a production age ranged from the Kamakura to the Muromachi period, estimation based on the fabrication technique, and a planning adze of cast iron with no definite origin. The former was dated as 880±150 y.B.P., corresponding to the calendar age ranged from AD 1021 to AD 1263, and the latter as 1720±160 y.B.P. with the calendar age ranged from AD 119 to AD 457 and from AD 483 to AD 508. These calibrated 14 C ages for both iron artifacts are consistent with the relevant ages conjectured by historical considerations. (author)

  19. Accelerator Mass Spectrometry at Arizona: Geochronology of the Climatic Record and Connections with the Ocean

    Directory of Open Access Journals (Sweden)

    J.T. Jull

    2002-01-01

    Full Text Available There are many diverse uses of accelerator mass spectrometry (AMS. 14C studies at our laboratory include much research related to paleoclimate, with 14C as a tracer of past changes in environmental conditions as observed in corals, marine sediments, and many terrestrial records. Terrestrial records can also show the influence of oceanic oscillations, whether they are short term, such as ENSO (El Niño/Southern Oscillation, or on the millennial time scale. In tracer applications, we have developed the use of 129I as well as 14C as tracers for nuclear pollution studies around radioactive waste dump sites, in collaboration with IAEA. We discuss some applications carried out in Tucson, AZ, for several of these fields and hope to give some idea of the breadth of these studies.

  20. Bright betatronlike x rays from radiation pressure acceleration of a mass-limited foil target.

    Science.gov (United States)

    Yu, Tong-Pu; Pukhov, Alexander; Sheng, Zheng-Ming; Liu, Feng; Shvets, Gennady

    2013-01-25

    By using multidimensional particle-in-cell simulations, we study the electromagnetic emission from radiation pressure acceleration of ultrathin mass-limited foils. When a circularly polarized laser pulse irradiates the foil, the laser radiation pressure pushes the foil forward as a whole. The outer wings of the pulse continue to propagate and act as a natural undulator. Electrons move together with ions longitudinally but oscillate around the latter transversely, forming a self-organized helical electron bunch. When the electron oscillation frequency coincides with the laser frequency as witnessed by the electron, betatronlike resonance occurs. The emitted x rays by the resonant electrons have high brightness, short durations, and broad band ranges which may have diverse applications.

  1. Penetration of bomb radiocarbon in the tropical Indian Ocean measured by means of accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Bard, E.; Arnold, M.; Maurice, P.; Monfray, P.; Duplessy, J.C.; Oestlund, H.G.

    1988-01-01

    Radiocarbon measurements performed on seawater samples by means of accelerator mass spectrometry (AMS) enable to reduce by a factor of 2000 the water sample size needed for the 14 C measurements. Therefore no chemical treatment on board the oceanographic vessel is required. Seventy-four AMS 14 C determinations on samples collected in the tropical-equatorial Indian Ocean during the second leg of the INDIGO program (1986) are presented and compared with the β-counting results obtained during the same campaign and the GEOSECS program (1978). A pronounced reduction of the equatorial 14 C deficit suggests that substantial amounts of bomb- 14 C are associated with the westward flowing Pacific water which enters the Indian Ocean via passages through the Indonesia Archipelago and/or to meridional mixing with 14 C-rich water of the southern subtropical gyre. (orig.)

  2. Plan for mass accelerator spectrometry at Gif-sur-Yvette and Saclay

    International Nuclear Information System (INIS)

    Berthier, B.; Bianchi, L.; Delibrias, G.; Koechlin, Y.

    1981-05-01

    From early 50', a carbon 14 dating laboratory was created at the Centre des Faibles Radioactivites de Gif-sur-Yvette (C.F.R.). From this time, more than 5,000 archaeological and geological samples were measured with the Libby method by this laboratory. C.F.R. is in the way to actualize its dating activities with the new accelerator method. A 3 MV General Ionex Tandetron is planed to be located at Gif-sur-Yvette next year and shared with Orsay University for 14 C. 10 Be and 36 Cl mass spectroscopy measurement. During the same time attempts have been made to adapt the Super FN Tandem of the Centre d'Etudes Nucleaires de Saclay for 14 C dating

  3. Label-assisted mass spectrometry for the acceleration of reaction discovery and optimization

    Science.gov (United States)

    Cabrera-Pardo, Jaime R.; Chai, David I.; Liu, Song; Mrksich, Milan; Kozmin, Sergey A.

    2013-05-01

    The identification of new reactions expands our knowledge of chemical reactivity and enables new synthetic applications. Accelerating the pace of this discovery process remains challenging. We describe a highly effective and simple platform for screening a large number of potential chemical reactions in order to discover and optimize previously unknown catalytic transformations, thereby revealing new chemical reactivity. Our strategy is based on labelling one of the reactants with a polyaromatic chemical tag, which selectively undergoes a photoionization/desorption process upon laser irradiation, without the assistance of an external matrix, and enables rapid mass spectrometric detection of any products originating from such labelled reactants in complex reaction mixtures without any chromatographic separation. This method was successfully used for high-throughput discovery and subsequent optimization of two previously unknown benzannulation reactions.

  4. Decay kinetics of nicotine/NNK-DNA adducts in vivo studied by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Sun, H.F.; He, L.; Liu, Y.F.; Liu, K.X.; Lu, X.Y.; Wang, J.J.; Ma, H.J.; Li, K.

    2000-01-01

    The decay kinetics of nicotine-DNA adducts and NNK-DNA adducts in mice liver after single dosing was studied by accelerator mass spectrometry (AMS). The decay is characterized by a two-stage process. The half-lives of nicotine-DNA adducts are 1.3 d (4-24 h) and 7.0 d (1-21 d), while for NNK-DNA adducts are 0.7 d (4-24 h) and 18.0 d (1-21 d). The relatively faster decay of nicotine-DNA adducts suggests that the genotoxicity of nicotine is weaker than that of NNK. The in vitro study shows that the metabolization of nicotine is necessary for the final formation of nicotine-DNA adducts, and nicotine Δ1'(5') iminium ion is a probable metabolite species that binds to DNA molecule covalently

  5. Enhancing sample preparation capabilities for accelerator mass spectrometry radiocarbon and radiocalcium studies

    International Nuclear Information System (INIS)

    Taylor, R.E.

    1991-01-01

    With support provided by the LLNL Accelerator Mass Spectrometry Laboratory, the UCR Radiocarbon Laboratory continued its studies involving sample pretreatment and target preparation for both AMS radiocarbon ( 14 C) and radiocalcium ( 41 Ca) involving applications to archaeologically -- and paleoanthropologically- related samples. With regard to AMS 14 C-related studies, we have extended the development of a series of procedures which have, as their initial goal, the capability to combust several hundred microgram amounts of a chemically-pretreated organic sample and convert the resultant CO 2 to graphitic carbon which will consistently yield relatively high 13 C - ion currents and blanks which will yield, on a consistent basis, 14 C count rates at or below 0.20% modern, giving an 2 sigma age limit of >50,000 yr BP

  6. Interlaboratory study of the ion source memory effect in {sup 36}Cl accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Pavetich, Stefan, E-mail: s.pavetich@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01314 Dresden (Germany); Akhmadaliev, Shavkat [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01314 Dresden (Germany); Arnold, Maurice; Aumaître, Georges; Bourlès, Didier [Aix-Marseille Université, CEREGE CNRS-IRD, F-13545 Aix-en-Provence (France); Buchriegler, Josef [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01314 Dresden (Germany); University of Vienna, Faculty of Physics, VERA Laboratory, Währingerstraße 17, 1090 Vienna (Austria); Golser, Robin [University of Vienna, Faculty of Physics, VERA Laboratory, Währingerstraße 17, 1090 Vienna (Austria); Keddadouche, Karim [Aix-Marseille Université, CEREGE CNRS-IRD, F-13545 Aix-en-Provence (France); Martschini, Martin [University of Vienna, Faculty of Physics, VERA Laboratory, Währingerstraße 17, 1090 Vienna (Austria); Merchel, Silke; Rugel, Georg [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01314 Dresden (Germany); Steier, Peter [University of Vienna, Faculty of Physics, VERA Laboratory, Währingerstraße 17, 1090 Vienna (Austria)

    2014-06-01

    Highlights: • Long-term memory effect in negative ion sources investigated for chlorine isotopes. • Interlaboratory comparison of four up-to date negative ion sources. • Ion source improvement at DREAMS for minimization of long-term memory effect. • Long-term memory effect is the limitation for precise AMS data of volatile elements. • Findings to be considered for samples with highly variable ratios of {sup 36}Cl/Cl and {sup 129}I/I. - Abstract: Understanding and minimization of contaminations in the ion source due to cross-contamination and long-term memory effect is one of the key issues for accurate accelerator mass spectrometry (AMS) measurements of volatile elements. The focus of this work is on the investigation of the long-term memory effect for the volatile element chlorine, and the minimization of this effect in the ion source of the Dresden accelerator mass spectrometry facility (DREAMS). For this purpose, one of the two original HVE ion sources at the DREAMS facility was modified, allowing the use of larger sample holders having individual target apertures. Additionally, a more open geometry was used to improve the vacuum level. To evaluate this improvement in comparison to other up-to-date ion sources, an interlaboratory comparison had been initiated. The long-term memory effect of the four Cs sputter ion sources at DREAMS (two sources: original and modified), ASTER (Accélérateur pour les Sciences de la Terre, Environnement, Risques) and VERA (Vienna Environmental Research Accelerator) had been investigated by measuring samples of natural {sup 35}Cl/{sup 37}Cl-ratio and samples highly-enriched in {sup 35}Cl ({sup 35}Cl/{sup 37}Cl ∼ 999). Besides investigating and comparing the individual levels of long-term memory, recovery time constants could be calculated. The tests show that all four sources suffer from long-term memory, but the modified DREAMS ion source showed the lowest level of contamination. The recovery times of the four ion

  7. Interlaboratory study of the ion source memory effect in 36Cl accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Pavetich, Stefan; Akhmadaliev, Shavkat; Arnold, Maurice; Aumaître, Georges; Bourlès, Didier; Buchriegler, Josef; Golser, Robin; Keddadouche, Karim; Martschini, Martin; Merchel, Silke; Rugel, Georg; Steier, Peter

    2014-01-01

    Highlights: • Long-term memory effect in negative ion sources investigated for chlorine isotopes. • Interlaboratory comparison of four up-to date negative ion sources. • Ion source improvement at DREAMS for minimization of long-term memory effect. • Long-term memory effect is the limitation for precise AMS data of volatile elements. • Findings to be considered for samples with highly variable ratios of 36 Cl/Cl and 129 I/I. - Abstract: Understanding and minimization of contaminations in the ion source due to cross-contamination and long-term memory effect is one of the key issues for accurate accelerator mass spectrometry (AMS) measurements of volatile elements. The focus of this work is on the investigation of the long-term memory effect for the volatile element chlorine, and the minimization of this effect in the ion source of the Dresden accelerator mass spectrometry facility (DREAMS). For this purpose, one of the two original HVE ion sources at the DREAMS facility was modified, allowing the use of larger sample holders having individual target apertures. Additionally, a more open geometry was used to improve the vacuum level. To evaluate this improvement in comparison to other up-to-date ion sources, an interlaboratory comparison had been initiated. The long-term memory effect of the four Cs sputter ion sources at DREAMS (two sources: original and modified), ASTER (Accélérateur pour les Sciences de la Terre, Environnement, Risques) and VERA (Vienna Environmental Research Accelerator) had been investigated by measuring samples of natural 35 Cl/ 37 Cl-ratio and samples highly-enriched in 35 Cl ( 35 Cl/ 37 Cl ∼ 999). Besides investigating and comparing the individual levels of long-term memory, recovery time constants could be calculated. The tests show that all four sources suffer from long-term memory, but the modified DREAMS ion source showed the lowest level of contamination. The recovery times of the four ion sources were widely spread between

  8. Report of the advisory group meeting on the utilization of particle accelerators for proton therapy

    International Nuclear Information System (INIS)

    1998-07-01

    Accelerated protons and light ions, being electrically charged and much heavier than electrons, have definite ranges in tissue with distinct Bragg peak with sharp distal falloffs and sharp lateral dose penumbra. Radiations oncologists could take advantage of these characteristics to deposit a high dose in an irregularly shaped tumor volume while sparing the surrounding healthy tissues and critical organs. This could lead to enhanced tumor control with reduced complications. The Advisory Group has recommended a number of measures to promote and support the spread of medically dedicated particle accelerator facilities and technology

  9. A Hardware Accelerator for Fault Simulation Utilizing a Reconfigurable Array Architecture

    Directory of Open Access Journals (Sweden)

    Sungho Kang

    1996-01-01

    Full Text Available In order to reduce cost and to achieve high speed a new hardware accelerator for fault simulation has been designed. The architecture of the new accelerator is based on a reconfigurabl mesh type processing element (PE array. Circuit elements at the same topological level are simulated concurrently, as in a pipelined process. A new parallel simulation algorithm expands all of the gates to two input gates in order to limit the number of faults to two at each gate, so that the faults can be distributed uniformly throughout the PE array. The PE array reconfiguration operation provides a simulation speed advantage by maximizing the use of each PE cell.

  10. Fast parallel tandem mass spectral library searching using GPU hardware acceleration.

    Science.gov (United States)

    Baumgardner, Lydia Ashleigh; Shanmugam, Avinash Kumar; Lam, Henry; Eng, Jimmy K; Martin, Daniel B

    2011-06-03

    Mass spectrometry-based proteomics is a maturing discipline of biologic research that is experiencing substantial growth. Instrumentation has steadily improved over time with the advent of faster and more sensitive instruments collecting ever larger data files. Consequently, the computational process of matching a peptide fragmentation pattern to its sequence, traditionally accomplished by sequence database searching and more recently also by spectral library searching, has become a bottleneck in many mass spectrometry experiments. In both of these methods, the main rate-limiting step is the comparison of an acquired spectrum with all potential matches from a spectral library or sequence database. This is a highly parallelizable process because the core computational element can be represented as a simple but arithmetically intense multiplication of two vectors. In this paper, we present a proof of concept project taking advantage of the massively parallel computing available on graphics processing units (GPUs) to distribute and accelerate the process of spectral assignment using spectral library searching. This program, which we have named FastPaSS (for Fast Parallelized Spectral Searching), is implemented in CUDA (Compute Unified Device Architecture) from NVIDIA, which allows direct access to the processors in an NVIDIA GPU. Our efforts demonstrate the feasibility of GPU computing for spectral assignment, through implementation of the validated spectral searching algorithm SpectraST in the CUDA environment.

  11. Accelerator mass spectrometry analyses of environmental radionuclides: sensitivity, precision and standardisation

    Science.gov (United States)

    Hotchkis; Fink; Tuniz; Vogt

    2000-07-01

    Accelerator Mass Spectrometry (AMS) is the analytical technique of choice for the detection of long-lived radionuclides which cannot be practically analysed with decay counting or conventional mass spectrometry. AMS allows an isotopic sensitivity as low as one part in 10(15) for 14C (5.73 ka), 10Be (1.6 Ma), 26Al (720 ka), 36Cl (301 ka), 41Ca (104 ka), 129I (16 Ma) and other long-lived radionuclides occurring in nature at ultra-trace levels. These radionuclides can be used as tracers and chronometers in many disciplines: geology, archaeology, astrophysics, biomedicine and materials science. Low-level decay counting techniques have been developed in the last 40-50 years to detect the concentration of cosmogenic, radiogenic and anthropogenic radionuclides in a variety of specimens. Radioactivity measurements for long-lived radionuclides are made difficult by low counting rates and in some cases the need for complicated radiochemistry procedures and efficient detectors of soft beta-particles and low energy x-rays. The sensitivity of AMS is unaffected by the half-life of the isotope being measured, since the atoms not the radiations that result from their decay, are counted directly. Hence, the efficiency of AMS in the detection of long-lived radionuclides is 10(6)-10(9) times higher than decay counting and the size of the sample required for analysis is reduced accordingly. For example, 14C is being analysed in samples containing as little as 20 microg carbon. There is also a world-wide effort to use AMS for the analysis of rare nuclides of heavy mass, such as actinides, with important applications in safeguards and nuclear waste disposal. Finally, AMS microprobes are being developed for the in-situ analysis of stable isotopes in geological samples, semiconductors and other materials. Unfortunately, the use of AMS is limited by the expensive accelerator technology required, but there are several attempts to develop compact AMS spectrometers at low (advances in AMS

  12. International Atomic Energy Agency programme and activity on the utilization of low energy accelerators

    International Nuclear Information System (INIS)

    Shalnov, A.V.; Whetstone, S.L.

    1974-01-01

    One of the chief missions of the Agency is as intermediary between the more highly developed of its member states and the less developed. This involves transmittal of needs of the latter to the former and, where possible, in response to the needs, an appropriate transfer of information and technical assistance. The physics section of the IAEA has recently encouraged and supported requests for technical assistance for programs based on neutron activation studies or pedagogic neutron physics experiments for institutes entering the nuclear field. Neutron generator laboratories have been set up with IAEA-assistance most recently in Burma, Hong Kong, Lebanon. Other recent technical assistance projects involving low-energy accelerators include: (1) consultation on the future program for the accelerator laboratory in Algeria; (2) equipment and experts to assist the nuclear physics program at the Van de Graaff in Bangladesh; (3) expert assistance and equipment in support of the installation of an electron linear accelerator in Egypt; and (4) expert assistance for nuclear physics studies at the cyclotron in Chile. A large number of young scientists, particularly from S.E. Europe, but also from the Middle East and South America, have received training in nuclear physics experimentation by advanced countries at low energy accelerator laboratories under the IAEA fellowship program

  13. Determination of 36Cl/Cl ratio in ground water using the accelerator mass spectrometry technique

    International Nuclear Information System (INIS)

    Sharma, Suman; Deodhar, A.S.; Saravana Kumar, U.; Surendran, P.; Shrivastava, A.; Gupta, A.K.; Nair, J.P.; Yadav, M.L.; Hemalatha, M.; Sparrow, H.; Mahata, K.; Thomas, R.G.; Bhagwat, P.V.; Kailas, S.; Kale, R.M.

    2009-01-01

    The Accelerator Mass Spectrometry (AMS) programme using the 14 MV Pelletron Accelerator at Mumbai has been initiated with major emphasis on the determination of 36 Cl in water samples, of interest to hydrology and environment. In order to carry out the AMS measurement, a beam chopper to cut down beam intensity by a factor of 20 has been developed and commissioned. A multi-anode gas -si detector has been built to separate 36 Cl from the interfering 36 S. A new TPS system has been procured to operate the machine in the GVM mode. Standard and blank samples from Prime lab, Purdue have been employed in these measurements to standardise the technique for 36 Cl/Cl ratio determination. The detector was calibrated using the stable 35,37 Cl ions. The background 36 Cl in the system has been measured using the blank sample from Purdue and it was estimated that the ratio of 36 Cl/Cl was of the order of 10 -13 in the present setup. Ground water samples collected from South India were converted to AgCl and put in the SNICS ion source for the AMS measurements. These ground water samples, with 14 C content estimated to be in the range of 1 to 4 pMC indicate that the samples may be more than 35,000 years old. Using the AMS technique we have determined the 36 Cl/Cl ratio values for these ground water samples. They are found to range between 2 to 5 x 10 -12 . Additional measurements are planned to determine the age of the water samples and to understand the reasons for the observed high values of 36 Cl in these samples. (author)

  14. Improved 36Cl performance at the ASTER HVE 5 MV accelerator mass spectrometer national facility

    International Nuclear Information System (INIS)

    Finkel, R.; Arnold, M.; Aumaître, G.; Benedetti, L.; Bourlès, D.; Keddadouche, K.; Merchel, S.

    2013-01-01

    The HVE 5 MV ASTER AMS national facility at CEREGE was accepted in 2007. Since then we have continued to optimize performance for 36 Cl. Cl-36 analyses use AgCl, a Cs negative ion sputter source, Ar stripping to +5 in the terminal of the Tandetron™ accelerator at 5 MV and a silicon nitride post-acceleration stripper foil to enhance suppression of 36 S relative to 36 Cl. The major challenges to obtaining the desired performance for Earth science applications are ion source memory, mass fractionation effects, 36 S isobar suppression and sensitivity. Redesign of the SO110 ion source by HVE to change the size of the aperture and the shape of cathode significantly reduced ion source memory to less than ∼0.1%, a level that can be compensated for by matching standards to samples. We observe small systematic drifts in 35 Cl/ 37 Cl ratios over time, the source of which is not yet determined. Measurement of standards indicates that this effect limits the precision of 35 Cl/ 37 Cl ratio determination to about 2%. 36 S is suppressed in several ways. First, the sample chemistry has been designed to reduce S to low levels. Second, cathodes are constructed of low-S nickel, enabling direct target loading without the use of AgBr pre-packing. Third, a post-acceleration Si 3 N 4 stripper foil differentially absorbs energy from 36 Cl and 36 S. A subsequent electrostatic deflector is then able to suppress 36 S by a factor of ∼240 relative to 36 Cl. Differential energy loss in the detector further suppresses 36 S by about 10 −4 , for an overall suppression factor of 4 × 10 −7 . 36 S count rates are typically equivalent to a background 36 Cl/Cl of ∼10 −15 . At typical 35 Cl currents of ∼20 μA Cl 5+ samples with 36 Cl/ 35 Cl of 6 × 10 −14 can be measured to ±5% statistical uncertainty with 1 h of analysis time. Typical machine blanks have 36 Cl/Cl ∼2 × 10 −15 .

  15. Accelerating experience : utility sector case studies in training and knowledge management

    Energy Technology Data Exchange (ETDEWEB)

    Trudel-Ferrari, C.C. [Kinectrics Inc., Toronto, ON (Canada)

    2010-07-01

    This paper discussed the development of effective training and knowledge management systems for recently hired personnel in electric utilities. Case studies of best practices from electric utilities in Ontario, consultants, and universities were used to develop an overview of current training practices. Methods of identifying, attracting, and recruiting personnel were presented and knowledge management and mentoring programs were discussed. The use of training programs in developing knowledge databases was also evaluated. Knowledge management formats included qualification training; simulation training; knowledge transfer; and curriculum development. Human resources, revenue, and management issues currently challenging electric utilities were discussed along with various new training practices. 2 refs., 3 tabs., 2 figs.

  16. Prospective utilization of accelerated heavy ions in basic and applied research

    International Nuclear Information System (INIS)

    Flerov, G.; Oganesyan, Yu.

    1982-01-01

    Some important and interesting trends of heavy ion physics are briefly presented, such as giant processes which are characterized by fundamental restructuring of nuclear systems containing hundreds of nucleons, the mechanism of heavy nuclei interaction, the study of nuclear matter compression, the study of the specificity of heating and thermal conductivity of nuclear matter, the study of heavy ion/nucleus interactions at energies of 200 to 300 MeV/nucleon when the meson degree of freedom becomes manifest, the possibility of the production of ions with a large excess or deficiency of neutrons, new possibilities for determining the fission barrier, the critical verification of fundamental physical concepts of quantum electrodynamics and other possibilities of using accelerated heavy ions. The significance of heavy ion physics for the development of acceleration technologies is also described. (B.S.)

  17. Joint Bratislava–Prague studies of radiocarbon and uranium in the environment using accelerator mass spectrometry and radiometric methods

    Czech Academy of Sciences Publication Activity Database

    Povinec, P. P.; Světlík, Ivo; Ješkovský, M.; Sivo, A.; John, J.; Špendlíková, I.; Němec, M.; Kučera, Jan; Richtáriková, M.; Breier, R.; Fejgl, Michal; Černý, Radek

    2015-01-01

    Roč. 304, č. 1 (2015), s. 67-73 ISSN 0236-5731 Institutional support: RVO:61389005 Keywords : Accelerator mass spectrometry * Atmosphere * Environmental radioactivity * Radiocarbon * Tree rings * Uranium Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.983, year: 2015

  18. Observational infant exploratory [14C]-paracetamol pharmacokinetic microdose/therapeutic dose study with accelerator mass spectrometry bioanalysis

    NARCIS (Netherlands)

    Garner, C.R.; Park, K.B.; French, N.S.; Earnshaw, C.; Schipani, A.; Selby, A.M.; Byrne, L.; Siner, S.; Crawley, F.P.; Vaes, W.H.J.; Duijn, E. van; ligt, R. de; Varendi, H.; Lass, J.; Grynkiewicz, G.; Maruszak, W.; Turner, M.A.

    2015-01-01

    Aims The aims of the study were to compare [14C]-paracetamol ([14C]-PARA) paediatric pharmacokinetics (PK) after administration mixed in a therapeutic dose or an isolated microdose and to develop further and validate accelerator mass spectrometry (AMS) bioanalysis in the 0-2 year old age group.

  19. Application of accelerator mass spectrometry on Environmental studies concerning ages of holocene fires in Central amazon forest

    International Nuclear Information System (INIS)

    Santos, G.M.; Gomes, P. R. S.; Anjos, R. M.; Lubian, J.; Cordeiro, R.C.; Turcq, B.; Sifeddine, A.; Di Tada, M.; Cresswell, R. G.; Fifield, L. K.

    1999-01-01

    The Accelerator Mass Spectrometry (AMS) technique was used to determine the radiocarbon age of Holocene fires in forests of the Amazon Region. Most of the ages were found to be within the 1000-1500 years range. These disturbances were probably caused by climatic anomalies, and they have modified the structure and dynamics of the region vegetation

  20. Assessing the Impact of Peer Educator Outreach on the Likelihood and Acceleration of Clinic Utilization among Sex Workers.

    Science.gov (United States)

    Krishnamurthy, Parthasarathy; Hui, Sam K; Shivkumar, Narayanan; Gowda, Chandrasekhar; Pushpalatha, R

    2016-01-01

    Peer-led outreach is a critical element of HIV and STI-reduction interventions aimed at sex workers. We study the association between peer-led outreach to sex workers and the time to utilize health facilities for timely STI syndromic-detection and treatment. Using data on the timing of peer-outreach interventions and clinic visits, we utilize an Extended Cox model to assess whether peer educator outreach intensity is associated with accelerated clinic utilization among sex workers. Our data comes from 2705 female sex workers registered into Pragati, a women-in-sex-work outreach program, and followed from 2008 through 2012. We analyze this data using an Extended Cox model with the density of peer educator visits in a 30-day rolling window as the key predictor, while controlling for the sex workers' age, client volume, location of sex work, and education level. The principal outcome of interest is the timing of the first voluntary clinic utilization. More frequent peer visit is associated with earlier first clinic visit (HR: 1.83, 95% CI, 1.75-1.91, p educator outreach. Peer outreach density is associated with increased likelihood of-and shortened duration to-clinic utilization among female sex workers, suggesting potential staff resourcing implications. Given the observational nature of our study, however, these findings should be interpreted as an association rather than as a causal relationship.

  1. Analysis of a Fossil Bone from Malu Rosu - Giurgiu by Accelerator Mass Spectroscopy

    International Nuclear Information System (INIS)

    Olariu, Agata; Popescu, I.V.; Hellborg, Ragnar; Stenstroem, Kristina; Skog, Goeran; Alexandrescu, E.

    2000-01-01

    In the present work we studied a fossil bone found in the archaeological site at Malu Rosu, near Giurgiu. Other specimens of fossil bones from Malu Rosu had been earlier dated by a chemical method, considering the content of the fluorine by neutron activation analysis. In this paper we have determined the age of a bone from Malu Rosu by the method of radiocarbon using the AMS (accelerator mass spectroscopy) technique. The measurement has been performed at 3 MeV Pelletron accelerator of the Lund University. The preparation of the bone sample was done in 2 steps: extraction of collagen from the structure of the bone by a chemical pretreatment, and then the transformation of collagen to pure carbon. The conversion to the elemental carbon is done also in two steps: formation of CO 2 by collagen combustion, and then the reduction of CO 2 to pure carbon. The sample of bone, as pure carbon is put in a copper holder and is arranged in a wheel in the following sequence: 5 carbon samples and 3 standards (1 standard of anthracite and 2 standards of oxalic acid). The anthracite being a very old coal is considered to have no 14 C traces and by its measurement one gets the background for 14 C both of the accelerator and of preparation installation of samples. Oxalic acid is a standard SRM prepared by USA National Bureau of Standards, with a well known activity of 14 C, measured in the Radiocarbon Dating Laboratory, Lund University, used to normalize the value of the 14 C counting rate, for the sample measured in the same conditions of beam current and time as the standard. The wheel with samples and standards are put in the ion source of the accelerator. The central part of the Lund AMS system is a Pelletron tandem accelerator (model 3UDH, produced by NEC, Wisconsin USA). The accelerator is run at 2.4 MV during AMS experiments, which is optimal for the C 3+ charge state. On the experimental beam line a magnetic quadrupole triplet, a velocity selector and a second analyzing

  2. Use of Accelerator Mass Spectrometry in Human Health and Molecular Toxicology.

    Science.gov (United States)

    Enright, Heather A; Malfatti, Michael A; Zimmermann, Maike; Ognibene, Ted; Henderson, Paul; Turteltaub, Kenneth W

    2016-12-19

    Accelerator mass spectrometry (AMS) has been adopted as a powerful bioanalytical method for human studies in the areas of pharmacology and toxicology. The exquisite sensitivity (10 -18 mol) of AMS has facilitated studies of toxins and drugs at environmentally and physiologically relevant concentrations in humans. Such studies include risk assessment of environmental toxicants, drug candidate selection, absolute bioavailability determination, and more recently, assessment of drug-target binding as a biomarker of response to chemotherapy. Combining AMS with complementary capabilities such as high performance liquid chromatography (HPLC) can maximize data within a single experiment and provide additional insight when assessing drugs and toxins, such as metabolic profiling. Recent advances in the AMS technology at Lawrence Livermore National Laboratory have allowed for direct coupling of AMS with complementary capabilities such as HPLC via a liquid sample moving wire interface, offering greater sensitivity compared to that of graphite-based analysis, therefore enabling the use of lower 14 C and chemical doses, which are imperative for clinical testing. The aim of this review is to highlight the recent efforts in human studies using AMS, including technological advancements and discussion of the continued promise of AMS for innovative clinical based research.

  3. Accelerator mass spectrometry (AMS) dating from the modern age to the past million age

    International Nuclear Information System (INIS)

    Sasa, K.; Nagashima, Y.; Seki, R.; Takahashi, T.; Tosaki, Y.; Sueki, K.; Bessyo, K.; Matsumura, H.; Miura, T.

    2006-01-01

    A multi-nuclide Accelerator Mass Spectrometry system at the University of Tsukuba (Tsukuba AMS system) is able to measure the long-lived radioisotopes of 14 C, 26 Al, 36 Cl and 129 I. The Tsukuba AMS system is able to perform AMS measurements with the terminal voltage of more than 10 MV. It is difficult to estimate the modern age dating (timescale of the past ten years) by the AMS dating method because the low attenuation of long-lived radioisotopes. The atomic bomb-produced radioisotopes are proposed as the environmental traces for the modern age dating. There is the advantage that the long half life of radioisotopes makes the attenuation negligilbe compared with the short half life of radioisotopes. We applied the 36 Cl bomb pulse as a dating tool for modern groundwater (∼50 years) instead of the 3 H bomb pulse. In addition, we have developed 32 Si-AMS system. The half life of 32 Si is about 140 years, therefore 32 Si-AMS is a useful tool for the modern age dating. On the other hand, we have started a new project to measure the cosmogenic nuclide of 36 Cl in an ice core retrieved from Dome Fuji station at Antarctic in order to investigate the past solar activity and the past earth environment as the timescale of the past million age. (author)

  4. Sample distillation/graphitization system for carbon pool analysis by accelerator mass spectrometry (AMS)

    International Nuclear Information System (INIS)

    Pohlman, J.W.; Knies, D.L.; Grabowski, K.S.; DeTurck, T.M.; Treacy, D.J.; Coffin, R.B.

    2000-01-01

    A facility at the Naval Research Laboratory (NRL), Washington, DC, has been developed to extract, trap, cryogenically distill and graphitize carbon from a suite of organic and inorganic carbon pools for analysis by accelerator mass spectrometry (AMS). The system was developed to investigate carbon pools associated with the formation and stability of methane hydrates. However, since the carbon compounds found in hydrate fields are ubiquitous in aquatic ecosystems, this apparatus is applicable to a number of oceanographic and environmental sample types. Targeted pools are dissolved methane, dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), solid organic matrices (e.g., seston, tissue and sediments), biomarkers and short chained (C 1 -C 5 ) hydrocarbons from methane hydrates. In most instances, the extraction, distillation and graphitization events are continuous within the system, thus, minimizing the possibility of fractionation or contamination during sample processing. A variety of methods are employed to extract carbon compounds and convert them to CO 2 for graphitization. Dissolved methane and DIC from the same sample are sparged and cryogenically separated before the methane is oxidized in a high temperature oxygen stream. DOC is oxidized to CO 2 by 1200 W ultraviolet photo-oxidation lamp, and solids oxidized in sealed, evacuated tubes. Hydrocarbons liberated from the disassociation of gas hydrates are cryogenically separated with a cryogenic temperature control unit, and biomarkers separated and concentrated by preparative capillary gas chromatography (PCGC). With this system, up to 20 samples, standards or blanks can be processed per day

  5. Associations between accelerated glacier mass wastage and increased summer temperature in coastal regions

    Science.gov (United States)

    Dyurgerov, M.; McCabe, G.J.

    2006-01-01

    Low-elevation glaciers in coastal regions of Alaska, the Canadian Arctic, individual ice caps around the Greenland ice sheet, and the Patagonia Ice Fields have an aggregate glacier area of about 332 ?? 103 km 2 and account for approximately 42% of all the glacier area outside the Greenland and Antarctic ice sheets. They have shown volume loss, especially since the end of the 1980s, increasing from about 45% in the 1960s to nearly 67% in 2003 of the total wastage from all glaciers on Earth outside those two largest ice sheets. Thus, a disproportionally large contribution of coastal glacier ablation to sea level rise is evident. We examine cumulative standardized departures (1961-2000 reference period) of glacier mass balances and air temperature data in these four coastal regions. Analyses indicate a strong association between increases in glacier volume losses and summer air temperature at regional and global scales. Increases in glacier volume losses in the coastal regions also coincide with an accelerated rate of ice discharge from outlet glaciers draining the Greenland and West Antarctic ice sheets. These processes imply further increases in sea level rise. ?? 2006 Regents of the University of Colorado.

  6. Adduction of DNA with MTBE and TBA in mice studied by accelerator mass spectrometry.

    Science.gov (United States)

    Yuan, Y; Wang, H F; Sun, H F; Du, H F; Xu, L H; Liu, Y F; Ding, X F; Fu, D P; Liu, K X

    2007-12-01

    Methyl tert-butyl ether (MTBE) is a currently worldwide used octane enhancer substituting for lead alkyls and gasoline oxygenate. Our previous study using doubly (14)C-labeled MTBE [(CH(3))(3) (14)CO(14)CH(3)] has shown that MTBE binds DNA to form DNA adducts at low dose levels in mice. To elucidate the mechanism of the binding reaction, in this study, the DNA adducts with singly (14)C-labeled MTBE, which was synthesized from (14)C-methanol and tert-butyl alcohol (TBA), or (14)C-labeled TBA in mice have been measured by ultra sensitive accelerator mass spectrometry. The results show that the methyl group of MTBE and tert-butyl alcohol definitely form adducts with DNA in mouse liver, lung, and kidney. The methyl group of MTBE is the predominant binding part in liver, while the methyl group and the tert-butyl group give comparable contributions to the adduct formation in lung and kidney.

  7. Kinetics of Beta-14[14C] Carotene in a Human Subject Using Accelerator Mass Spectrometry

    International Nuclear Information System (INIS)

    Dueker, S.R.; Lin, Y.; Follett, J.R.; Clifford, A.J.; Buchholz, B.A.

    2000-01-01

    β-Carotene is a tetraterpenoid distributed widely throughout the plant kingdom. It is a member of a group of pigments referred to as carotenoids that have the distinction of serving as metabolic precursors to vitamin A in humans and many animals [1,2]. We used Accelerator Mass Spectrometry (AMS) [3] to determine the metabolic behavior of a physiologic oral dose of β-[ 14 C]carotene (200 nanoCuries; 0.57 (micro)mol) in a healthy human subject. Serial blood specimens were collected for 210-d and complete urine and feces were collected for 17 and 10-d, respectively. Balance data indicated that the dose was 42% bioavailable. The absorbed β-carotene was lost slowly via urine in accord with the slow body turnover of β-carotene and vitamin A [4]. HPLC fractionation of plasma taken at early time points (0-24-h) showed the label was distributed between β-carotene and retinyl esters (vitamin A) derived from intestinal metabolism

  8. Quantitation of 14C-oxaliplatin concentrations in human serum samples by using accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Kobayashi, Takeshi; Toyoguchi, Teiko; Kato, Kazuhiro; Tokanai, Fuyuki; Shiraishi, Tadashi

    2013-01-01

    The understanding of human pharmacokinetics is important for development of new drugs. Microdosing studies have been proposed as means of obtaining human pharmacokinetics information at early stages of drug development. Accelerator mass spectrometry (AMS) has high detection sensitivity and is expected to play an important role in microdose trials. In this study, we used the AMS microdosing facility at Yamagata University to measure the concentration of 14 C in 14 C-oxaliplatin-spiked serum samples. The calibration curve of 14 C concentration in serum was linear, and the correlation coefficient was 0.9994. The precision, accuracy, and stability values obtained (freeze and thaw cycles, and short- and long-term stability) satisfied the criteria. The mean background 14 C concentrations in samples of 6 healthy Japanese volunteers were 1.635dpm/mL in blood and 0.56dpm/mL in plasma. These results suggest the suitability of AMS-based quantitation for analyzing samples from microdosing studies. (author)

  9. Radiocarbon dating by accelerator mass spectrometry: some recent results and applications

    International Nuclear Information System (INIS)

    Hedges, R.E.M.

    1987-01-01

    14 C differs from other nuclides measured by accelerator mass spectrometry (AMS) in that an extensive database of dates already exists. AMS dates should therefore have comparable accuracy, and the measurement of isotopic ratios to better than 1%, which was an important technical goal, has been reached. The main advantage of being able to date samples 1000 times smaller than previously lies in the extra selectivity that can be employed. This is reflected in the results and applications. Selection can apply at several levels; from objects that formerly contained too little carbon, to the choice of archaeological material, to the extraction of specific chemical compounds from a complex environmental sample. This is particularly useful in removing uncertainty regarding the validity of a date, since a given sample may comprise carbon atoms from different sources each with their own 14 C 'age'. Examples from archaeological and environmental research illustrating these points are given. 14 C dating by AMS differs from conventional radiocarbon dating by having the potential to measure much lower levels of 14 C, and therefore should double the time span of the method. This potential has not yet been realized because of sample contamination effects, and work in progress to reduce these is described. (author)

  10. Detection of Adriamycin-DNA adducts by accelerator mass spectrometry at clinically relevant Adriamycin concentrations.

    Science.gov (United States)

    Coldwell, Kate E; Cutts, Suzanne M; Ognibene, Ted J; Henderson, Paul T; Phillips, Don R

    2008-09-01

    Limited sensitivity of existing assays has prevented investigation of whether Adriamycin-DNA adducts are involved in the anti-tumour potential of Adriamycin. Previous detection has achieved a sensitivity of a few Adriamycin-DNA adducts/10(4) bp DNA, but has required the use of supra-clinical drug concentrations. This work sought to measure Adriamycin-DNA adducts at sub-micromolar doses using accelerator mass spectrometry (AMS), a technique with origins in geochemistry for radiocarbon dating. We have used conditions previously validated (by less sensitive decay counting) to extract [(14)C]Adriamycin-DNA adducts from cells and adapted the methodology to AMS detection. Here we show the first direct evidence of Adriamycin-DNA adducts at clinically-relevant Adriamycin concentrations. [(14)C]Adriamycin treatment (25 nM) resulted in 4.4 +/- 1.0 adducts/10(7) bp ( approximately 1300 adducts/cell) in MCF-7 breast cancer cells, representing the best sensitivity and precision reported to date for the covalent binding of Adriamycin to DNA. The exceedingly sensitive nature of AMS has enabled over three orders of magnitude increased sensitivity of Adriamycin-DNA adduct detection and revealed adduct formation within an hour of drug treatment. This method has been shown to be highly reproducible for the measurement of Adriamycin-DNA adducts in tumour cells in culture and can now be applied to the detection of these adducts in human tissues.

  11. Accelerator mass spectrometry 14C determination in CO2 produced from laser decomposition of aragonite.

    Science.gov (United States)

    Rosenheim, Brad E; Thorrold, Simon R; Roberts, Mark L

    2008-11-01

    The determination of (14)C in aragonite (CaCO(3)) decomposed thermally to CO(2) using an yttrium-aluminum-garnet doped neodymium laser is reported. Laser decomposition accelerator mass spectrometry (LD-AMS) measurements reproduce AMS determinations of (14)C from the conventional reaction of aragonite with concentrated phosphoric acid. The lack of significant differences between these sets of measurements indicates that LD-AMS radiocarbon dating can overcome the significant fractionation that has been observed during stable isotope (C and O) laser decomposition analysis of different carbonate minerals. The laser regularly converted nearly 30% of material removed into CO(2) despite it being optimized for ablation, where laser energy breaks material apart rather than chemically altering it. These results illustrate promise for using laser decomposition on the front-end of AMS systems that directly measure CO(2) gas. The feasibility of such measurements depends on (1) the improvement of material removal and/or CO(2) generation efficiency of the laser decomposition system and (2) the ionization efficiency of AMS systems measuring continuously flowing CO(2).

  12. Genotoxicity study on nicotine and nicotine-derived nitrosamine by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Li, X.S.; Wang, H.F.; Shi, J.Y.; Wang, X.Y.; Liu, Y.F.; Li, K.; Lu, X.Y.; Wang, J.J.; Liu, K.X.; Guo, Z.Y.

    1997-01-01

    The authors have studied DNA adduction with 14 C-labelled nicotine and nicotine-derived nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), by accelerator mass spectrometry (AMS) in mouse liver at doses equivalent to low-level exposure of humans. The dose ranges of nicotine and NNK administered were from 0.4 μg to 4.0 x 10 2 μg·kg -1 , and from 0.1 μg to 2.0 x 10 4 μg·kg -1 , respectively. In the exposure of mice to either nicotine or NNK, the number of DNA adducts increased linearly with increasing dose. The detection limit of DNA adducts was 1 adduct per 10 11 nucleotide molecules. This limit is 1-4 orders of magnitude lower than that of other techniques used for quantification of DNA adducts. The results of the animal experiments enabled us to speculate that nicotine is a potential carcinogen. According to the procedure for 14 C-labelled-NNK synthesis, the authors discuss the ultimate chemical speciation of NNK bound to DNA. From the animal tests the authors derived a directly perceivable relation between tobacco consumption and DNA adduction as the carcinogenic risk assessment

  13. Evaluation of 14C abundance in soil respiration using accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Koarashi, Jun; Iida, Takao; Moriizumi, Jun; Asano, Tomohiro

    2004-01-01

    To clarify the behavior of 14 C in terrestrial ecosystems, 14 C abundance in soil respiration was evaluated in an urban forest with a new method involving a closed chamber technique and 14 C measurement by accelerator mass spectrometry (AMS). Soil respiration had a higher Δ 14 C than the contemporary atmosphere. This indicates that a significant portion of soil respiration is derived from the decomposition of soil organic matter enriched in 14 C by atmospheric nuclear weapons tests, with a notable time lag between atmospheric 14 C addition and re-emission from soil. On the other hand, δ 14 C in soil respiration demonstrated that 14 C abundance ratio itself in soil-respired CO 2 is not always high compared with that in atmospheric CO 2 because of the isotope fractionation during plant photosynthesis and microbial decomposition of soil organic matter. The Δ 14 C in soil respiration was slightly lower in August than in March, suggesting a relatively high contribution of plant root respiration and decomposition of newly accumulated and/or 14 C-depleted soil organic matter to the total soil respiration in August

  14. Detection of long-lived plutonium isotopes in environmental samples by Accelerator Mass Spectrometry (AMS)

    Energy Technology Data Exchange (ETDEWEB)

    Hain, Karin; Faestermann, Thomas; Fimiani, Leticia; Gomez Guzman, Jose Manuel; Korschinek, Gunther; Ludwig, Peter [Technische Universitaet Muenchen (Germany); Shinonaga, Taeko [Helmholtz Zentrum Muenchen (Germany)

    2013-07-01

    The Plutonium isotopes {sup 239}Pu (T{sub 1/2}=2.4.10{sup 4}a), {sup 240}Pu (T{sub 1/2}=6.5.10{sup 3}a) and {sup 242}Pu (T{sub 1/2}=3.7.10{sup 5}a) are anthropogenic radionuclides emitted into the environment by nuclear activities. Pu is accumulated in the human body and hence, poses a considerable hazard to human health. Due to the long half-lives, these isotopes are present in the biosphere on large time scales and a build-up can be expected. Therefore it is important to study the contamination pathway of Pu into the drinking water. At the Maier-Leibnitz-Laboratory in Munich a method to detect long-lived Pu isotopes by Accelerator Mass Spectrometry (AMS) is being developed. AMS requires only few milligrams of sample material, which is a substantial advantage over decay counting techniques. Consequently, more samples from different locations can be taken which is essential when searching for locally increased Pu concentrations as in the Pacific Ocean after the Fukushima accident in March 2011. Samples from different locations in the Pacific Ocean and from the snow-hydrosphere are planned to be investigated by AMS. The principle detection method using AMS and an overview of the status of the project is presented.

  15. Accelerator mass spectrometry for analysis of 10Be. Applications in marine geology

    International Nuclear Information System (INIS)

    Segl, M.

    1985-01-01

    Using the Accelerator Mass Spectrometry the behaviour of long-lived (half time 1.5 Million years) cosmogenic isotopes 10 Be in a marine environment was examined. The geochemical behaviour of 10 Be in oceans was examined in a water profile of the eastern Atlantic and on sediment cores from the eastern Atlantic and the Antarctica. The retention period in oceans was calculated from the water profile to be 700-1000 years. The examination of sedimentary cores showed, that the 10 Be flow into the sediment in areas of high bioproductivity surpasses the production rate. Comparison of 10 Be flow with 230 Th flow into the examined sedimentary cores showed a period of retention of 10 Be in the ocean of only about 400 years. Changes in the sedimentation rate and changes in the mineralogical composition correlate with paleooceanographic events, the start of the Antarctica icing 14 million years ago, changes in the deep water circulation 6.5 million years ago and the icing over of the northern hemisphere 3 million years ago. The same paleooceanographic events find correlation with the inside structure of a total of 16 manganese nodes and crusts from diverse parts of the ocean which were also dated with 10 Be. (orig./DG) [de

  16. Test facility of proton beam utilization of the PEFP at the SNU-AMS tandem accelerator

    International Nuclear Information System (INIS)

    Kim, K. R.; Park, B. S.; Lee, H. R.

    2004-01-01

    The PEFP (Proton Engineering Frontier Project) will supply users with a 20-MeV proton beam by the middle of 2007. A survey on users' demand was performed to draw the concept for the 20-MeV user facilities and to investigate users' requirements. In the mean time, a 6-MeV test facility has been developed to give users opportunities to experiment with proton beams. That facility will be attached to the 3-MV tandem accelerator at Seoul National University.

  17. Study of mechanism of cancer caused by carcinogenic substances with accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Jiang Shan; He Ming; Wu Shaoyong; You Qubo; Xu Guoji; Wang Qien; Liu Shijie

    2001-01-01

    Full text: It is reported that most of the cancerous patients were caused by cancerogenic substances. The research in recent years shows that carcinogenesis is related with Ca in the cells. In normal cells, the level of free Ca 2+ is very stable, the Ca 2+ as messenger plays an important role to keep normal function of cells. However, the level of free Ca 2+ in cells increases when the cells are exposed to cancerogenic substances such as cigarette smoking solution and chrysotile. But where do the increased Ca 2+ come from? There are three possibilities: 1) from outside of cell membrane; 2) from inside of nucleus; or 3) from both outside and inside of cells. By using external cultivation of cells 41 Ca as tracer and accelerator mass spectrometry (AMS) as measurement method, we investigate the origin of the increased Ca 2+ when the cells are exposed to cigarette smoking solution or chrysoltile is being undertaken. Several results as below have been gotten. 1. 41 Ca synthesis. A high purification of isotope of 40 Ca (99.95%) in form of CaO was irradiated by thermal neutron with a heavy water reactor at the China Institute of Atomic Energy (CIAE). The irradiation time and neutron flux were 988h and 4.9x10 13 , respectively. A 41 Ca/ 40 Ca ratio of 7x10 -5 was obtained. The conversion efficiency of Ca metal to CaH 2 was 80% to 90%. 2. CaH 2 sample preparation. There are two steps for CaH 2 sample preparation in AMS measurement. In the first step, CaO is reduced to metallic calcium via vacuum distillation and in the second, the CaO is converted into a hybrid. 3. 41 Ca AMS measurement. The first 41 Ca AMS measurement was performed with Hl-13 tandem AMS system in the CIAE. By using a 41 Ca blank sample, 30 nA of CaH 3 - ions from ion source can be obtained. Ions were accelerated with a terminal voltage of 7.8 and Ca 8+ (E=69.7 MeV) ions were selected. From the measurement, a 41 Ca/ 40 Ca ratio of about 10 -14 was deduced. (author)

  18. Application of accelerator mass spectrometry to environmental research, Trial of GC-AMS

    International Nuclear Information System (INIS)

    Shibata, Yasuyuki

    2003-01-01

    The accelerator analysis facility of the National Institute for Environmental Studies, which aims to develop a new device capable of measuring "1"4C age for each compound, is promoting the study to establish the GC-AMS that combines two-dimensional gas chromatograph (GC) and accelerator mass spectrometry (AMS). The on-line GC-AMS system for the metabolic measurement of "1"4C-labeled compounds for medicinal biochemical research is a system, in which a GC-separated sample is continuously converted into CO_2 in a combustion tube and introduced directly to a gas ion source to continuously measure "1"4C. In the "1"4C detection experiment, the concentration of CO_2 gas was changed using a helium introduction line and a sample injection valve, and CO_2 gas plus helium gas were introduced into the gas ion source. As a result, it was found that the online GC-AMS has feasibility and high potential capability. For off-line GC-AMS for environmental samples, after purification with preparative gas chromatography, the sample is converted to graphite in a vacuum line and applied to common AMS measurement. The authors collected Northwest Pacific Ocean bottom sediment cores, and performed the extraction and purification of fatty acids of specific stratigraphy and the "1"4C measurement of each compound. The age of the compound derived from the surface layer planktons was the result capable of indicating the sedimentary age of the stratigraphy. In addition, as an application study to explore the source of pollutants in the environment using "1"4C as a tracer representing the characteristics of each source, the authors started to conduct the research choosing atmospheric dust samples. As a starting point, the authors attempted to measure the "1"4C concentration of vehicle exhaust particles and incinerator fly ash particles respectively. There was hardly any "1"4C in vehicle exhaust particles. (A.O.)

  19. The Effect of Accelerated Aging on Germination Characteristics, Seed Reserve Utilization and Malondialdehyde Content of Two Wheat Cultivars

    Directory of Open Access Journals (Sweden)

    Maryam Goodarzian Ghahfarokhi

    2014-05-01

    Full Text Available In this study experiment was conducted to evaluated the effect of accelerated aging on germination characteristics, seed reserve utilization and malondialdehyde of two wheat cultivars. The experiment was conducted in factorial with a randomized complete block design with 3 replications. Results of variance analysis showed that, seed aging had significant effects on germination percentage, germination index, normal seedling percentage, mean time to germination, malondialdehyde content, seedling dry weight, weight of utilized (mobilized seed reserve and electrical conductivity. The highest germination percentage, germination index, normal seedling percentage, seedling dry weight and weight of utilized (mobilized seed reserve and the minimum mean time to germination, electrical conductivity and malondialdehyde content were attained from Verinak cultivar under control conditions (0 day aging. Results indicates that germination percentage, germination index, normal seedling percentage, seedling dry weight, and weight of utilized (mobilized seed reserve decreased significantly as seed aging progressed. But, mean time to germination, electrical conductivity and malondialdehyde content increased significantly as seed aging progressed. Also, the decrease in seed reserve mobilization rate was the cause of decreased other traits.

  20. Annual report of Department of Research Reactor and Tandem Accelerator, JFY2014. Operation, Utilization and Technical Development of JRR-3, JRR-4, NSRR, Tandem Accelerator and RI Production Facility

    International Nuclear Information System (INIS)

    Osa, Akihiko; Imahashi, Masaki; Hirane, Nobuhiko; Motome, Yuiko; Tayama, Hidekazu; Tamura, Itaru; Harada, Yuko; Sakata, Mami; Kadokura, Masakazu; Takita, Chiharu

    2017-02-01

    The Department of Research Reactor and Tandem Accelerator is in charge of the operation, utilization and technical development of JRR-3 (Japan Research Reactor No.3), JRR-4 (Japan Research Reactor No.4), NSRR (Nuclear Safety Research Reactor), Tandem Accelerator and RI Production Facility. This annual report describes the activities of our department in fiscal year of 2014. We carried out the operation and maintenance, utilization, upgrading of utilization techniques, safety administration, and international cooperation. Also contained are lists of publications, meetings, granted permissions on laws and regulations concerning atomic energy, outcomes in service and technical developments and so on. (author)

  1. Annual report of Department of Research Reactor and Tandem Accelerator, JFY2013. Operation, Utilization and Technical Development of JRR-3, JRR-4, NSRR, Tandem Accelerator and RI Production Facility

    International Nuclear Information System (INIS)

    Kashima, Yoichi; Murayama, Yoji; Nakamura, Kiyoshi; Uno, Yuki; Hirane, Nobuhiko; Ohuchi, Hitoshi; Ishizaki, Nobuhiro; Matsumura, Taichi; Nagahori, Kazuhisa; Harada, Yuko; Kadokura, Masakazu; Machi, Sumire; Takita, Chiharu

    2015-02-01

    The Department of Research Reactor and Tandem Accelerator is in charge of the operation, utilization and technical development of JRR-3(Japan Research Reactor No.3), JRR-4(Japan Research Reactor No.4), NSRR(Nuclear Safety Research Reactor), Tandem Accelerator and RI Production Facility. This annual report describes the activities of our department in fiscal year of 2013. We carried out the operation and maintenance, utilization, upgrading of utilization techniques, safety administration and international cooperation. Also contained are lists of publications, meetings, granted permissions on laws and regulations concerning atomic energy, outcomes in service and technical developments and so on. (author)

  2. Automated combustion accelerator mass spectrometry for the analysis of biomedical samples in the low attomole range.

    Science.gov (United States)

    van Duijn, Esther; Sandman, Hugo; Grossouw, Dimitri; Mocking, Johannes A J; Coulier, Leon; Vaes, Wouter H J

    2014-08-05

    The increasing role of accelerator mass spectrometry (AMS) in biomedical research necessitates modernization of the traditional sample handling process. AMS was originally developed and used for carbon dating, therefore focusing on a very high precision but with a comparably low sample throughput. Here, we describe the combination of automated sample combustion with an elemental analyzer (EA) online coupled to an AMS via a dedicated interface. This setup allows direct radiocarbon measurements for over 70 samples daily by AMS. No sample processing is required apart from the pipetting of the sample into a tin foil cup, which is placed in the carousel of the EA. In our system, up to 200 AMS analyses are performed automatically without the need for manual interventions. We present results on the direct total (14)C count measurements in <2 μL human plasma samples. The method shows linearity over a range of 0.65-821 mBq/mL, with a lower limit of quantification of 0.65 mBq/mL (corresponding to 0.67 amol for acetaminophen). At these extremely low levels of activity, it becomes important to quantify plasma specific carbon percentages. This carbon percentage is automatically generated upon combustion of a sample on the EA. Apparent advantages of the present approach include complete omission of sample preparation (reduced hands-on time) and fully automated sample analysis. These improvements clearly stimulate the standard incorporation of microtracer research in the drug development process. In combination with the particularly low sample volumes required and extreme sensitivity, AMS strongly improves its position as a bioanalysis method.

  3. Modeling the impact and costs of semiannual mass drug administration for accelerated elimination of lymphatic filariasis.

    Directory of Open Access Journals (Sweden)

    Wilma A Stolk

    Full Text Available The Global Program to Eliminate Lymphatic Filariasis (LF has a target date of 2020. This program is progressing well in many countries. However, progress has been slow in some countries, and others have not yet started their mass drug administration (MDA programs. Acceleration is needed. We studied how increasing MDA frequency from once to twice per year would affect program duration and costs by using computer simulation modeling and cost projections. We used the LYMFASIM simulation model to estimate how many annual or semiannual MDA rounds would be required to eliminate LF for Indian and West African scenarios with varied pre-control endemicity and coverage levels. Results were used to estimate total program costs assuming a target population of 100,000 eligibles, a 3% discount rate, and not counting the costs of donated drugs. A sensitivity analysis was done to investigate the robustness of these results with varied assumptions for key parameters. Model predictions suggested that semiannual MDA will require the same number of MDA rounds to achieve LF elimination as annual MDA in most scenarios. Thus semiannual MDA programs should achieve this goal in half of the time required for annual programs. Due to efficiency gains, total program costs for semiannual MDA programs are projected to be lower than those for annual MDA programs in most scenarios. A sensitivity analysis showed that this conclusion is robust. Semiannual MDA is likely to shorten the time and lower the cost required for LF elimination in countries where it can be implemented. This strategy may improve prospects for global elimination of LF by the target year 2020.

  4. Emergence of the mass discrepancy-acceleration relation from dark matter-baryon interactions

    Science.gov (United States)

    Famaey, Benoit; Khoury, Justin; Penco, Riccardo

    2018-03-01

    The observed tightness of the mass discrepancy-acceleration relation (MDAR) poses a fine-tuning challenge to current models of galaxy formation. We propose that this relation could arise from collisional interactions between baryons and dark matter (DM) particles, without the need for modification of gravity or ad hoc feedback processes. We assume that these interactions satisfy the following three conditions: (i) the relaxation time of DM particles is comparable to the dynamical time in disk galaxies; (ii) DM exchanges energy with baryons due to elastic collisions; (iii) the product between the baryon-DM cross section and the typical energy exchanged in a collision is inversely proportional to the DM number density. As a proof of principle, we present an example of a particle physics model that gives a DM-baryon cross section with the desired density and velocity dependence. For consistency with direct detection constraints, our DM particles must be either very light (m ll mb) or very heavy (mgg mb), corresponding respectively to heating and cooling of DM by baryons. In both cases, our mechanism applies and an equilibrium configuration can in principle be reached. In this exploratory paper, we focus on the heavy DM/cooling case because it is technically simpler, since the average energy exchanged turns out to be approximately constant throughout galaxies. Under these assumptions, we find that rotationally-supported disk galaxies could naturally settle to equilibrium configurations satisfying a MDAR at all radii without invoking finely tuned feedback processes. We also discuss issues related to the small scale clumpiness of baryons, as well as predictions for pressure-supported systems. We argue in particular that galaxy clusters do not follow the MDAR despite being DM-dominated because they have not reached their equilibrium configuration. Finally, we revisit existing phenomenological, astrophysical and cosmological constraints on baryon-DM interactions in light

  5. Detection of sputtered molecular doubly charged anions: a comparison of secondary-ion mass spectrometry (SIMS) and accelerator mass spectrometry (AMS)

    International Nuclear Information System (INIS)

    Gnaser, Hubert; Golser, Robin; Kutschera, Walter; Priller, Alfred; Steier, Peter; Vockenhuber, Christof

    2004-01-01

    The detection of small molecular dianions by secondary-ion mass spectrometry (SIMS) and by accelerator mass spectrometry (AMS) is compared. In SIMS, the existence of these dianions can be identified safely if the total mass number of the molecule is odd and the dianion is hence detected at a half-integral mass number. The occurrence of fragmentation processes which may interfere with this scheme, is illustrated by means of the energy spectra of singly and doubly charged negative cluster ions. As compared to SIMS, AMS can rely, in addition, on the break-up of molecular species in the stripping process: this allows to monitor the simultaneous arrival of several atomic constituents with a clear energetic pattern in coincidence at the detector. This feature is exemplified for the C 10 2- dianion

  6. Electron beam accelerator at BARC-BRIT complex - electron beam processing of materials and industrial utilization

    International Nuclear Information System (INIS)

    Khader, S.A.; Patkari, R.K.; Sharma, K.S.S.

    2013-01-01

    During the last decade, the 2MeV/20kW electron beam (EB) accelerator located at BARC-BRIT complex, Vashi has been successfully utilised for non-thermal applications to develop speciality products useful for the industry. Polymer materials are exposed to high energy electrons to induce crosslinking and degradation reactions in a number of industrial products without the use of external chemicals and additives. Various EB crosslinked products viz. PE O-rings, automotive components, automobile tyres, electrical insulations, etc have been found to be much superior in quality compared to those produced conventionally. A process has been developed to enhance colours in the polished diamonds and gem stones using EB irradiation at the facility which has attracted much attention in the Indian diamond industry as a value-addition process. Recycling of polymer waste processed under EB to produce microfine PTFE powder, to reuse in automobile industry etc. has shown good potential for the industrial use. The process feasibility both in terms of economics and technology have been amply demonstrated on a technological scale by installing special conveyors at our facility for irradiating various industrial products. Around 100 km cable insulations, 1.5 million PE O-rings and more than 40000 carats of polished diamonds have been processed in our facility over a period of time on commercial scale. Encouraged with the results, Indian private entrepreneurs have set up dedicated EB machines in some of the most significant industries producing wire and cables, electrical gadgets based on polymer composites, automobile tyres and diamonds. The products are unique in properties and are in some cases, became import substitutes. The industry is now fully geared up to adapt the technology by realising the advantages viz ease in adaptability, convenient, safe and environmental-friendly nature. Encouraged by the process demonstrations, while five EB accelerators were setup and are in operation

  7. Assessing the Impact of Peer Educator Outreach on the Likelihood and Acceleration of Clinic Utilization among Sex Workers.

    Directory of Open Access Journals (Sweden)

    Parthasarathy Krishnamurthy

    Full Text Available Peer-led outreach is a critical element of HIV and STI-reduction interventions aimed at sex workers. We study the association between peer-led outreach to sex workers and the time to utilize health facilities for timely STI syndromic-detection and treatment. Using data on the timing of peer-outreach interventions and clinic visits, we utilize an Extended Cox model to assess whether peer educator outreach intensity is associated with accelerated clinic utilization among sex workers.Our data comes from 2705 female sex workers registered into Pragati, a women-in-sex-work outreach program, and followed from 2008 through 2012. We analyze this data using an Extended Cox model with the density of peer educator visits in a 30-day rolling window as the key predictor, while controlling for the sex workers' age, client volume, location of sex work, and education level. The principal outcome of interest is the timing of the first voluntary clinic utilization.More frequent peer visit is associated with earlier first clinic visit (HR: 1.83, 95% CI, 1.75-1.91, p < .001. In addition, 18% of all syndrome-based STI detected come from clinic visits in which the sex worker reports no symptoms, underscoring the importance of inducing clinic visits in the detection of STI. Additional models to test the robustness of these findings indicate consistent beneficial effect of peer educator outreach.Peer outreach density is associated with increased likelihood of-and shortened duration to-clinic utilization among female sex workers, suggesting potential staff resourcing implications. Given the observational nature of our study, however, these findings should be interpreted as an association rather than as a causal relationship.

  8. Verification of the sputter-generated 32SFn- (n = 1-6) anions by accelerator mass spectrometry

    Science.gov (United States)

    Mane, R. G.; Surendran, P.; Kumar, Sanjay; Nair, J. P.; Yadav, M. L.; Hemalatha, M.; Thomas, R. G.; Mahata, K.; Kailas, S.; Gupta, A. K.

    2016-01-01

    Recently, we have performed systematic Secondary Ion Mass Spectrometry (SIMS) measurements at our ion source test set up and have demonstrated that gas phase 32SFn- (n = 1-6) anions for all size 'n' can be readily generated from a variety of surfaces undergoing Cs+ ion sputtering in the presence of high purity SF6 gas by employing the gas spray-cesium sputter technique. In our SIMS measurements, the isotopic yield ratio 34SFn-/32SFn- (n = 1-6) was found to be close to its natural abundance but not for all size 'n'. In order to gain further insight into the constituents of these molecular anions, ultra sensitive Accelerator Mass Spectrometry (AMS) measurements were conducted with the most abundant 32SFn- (n = 1-6) anions, at BARC-TIFR 14 UD Pelletron accelerator. The results from these measurements are discussed in this paper.

  9. Comparison of accelerator mass spectrometric measurement with liquid scintillation counting measurement for the determination of 14C in environmental samples

    International Nuclear Information System (INIS)

    Yasuike, Kaeko; Yamada, Yoshimune; Amano, Hikaru

    2010-01-01

    The concentrations of organically-bound 14 C in tree-ring cellulose of a Japanese Black Pine grown in Shika-machi (37.0 deg. N, 136.8 deg. E) and those of a Japanese Cedar grown in Kanazawa (36.5 deg. N, 136.7 deg. E), Japan, were analyzed for the ring-years from 1989 to 1998 by the accelerator mass spectrometric measurement. The results were compared with those of the same samples analyzed by the liquid scintillation counting measurement to determine the reliability of liquid scintillation counting measurement. An important result of this study is that the sensitivity and reproducibility of accelerator mass spectrometric measurement was almost equal to that of liquid scintillation counting measurement.

  10. Comparing joint kinematics and center of mass acceleration as feedback for control of standing balance by functional neuromuscular stimulation.

    Science.gov (United States)

    Nataraj, Raviraj; Audu, Musa L; Triolo, Ronald J

    2012-05-06

    The purpose of this study was to determine the comparative effectiveness of feedback control systems for maintaining standing balance based on joint kinematics or total body center of mass (COM) acceleration, and assess their clinical practicality for standing neuroprostheses after spinal cord injury (SCI). In simulation, controller performance was measured according to the upper extremity effort required to stabilize a three-dimensional model of bipedal standing against a variety of postural disturbances. Three cases were investigated: proportional-derivative control based on joint kinematics alone, COM acceleration feedback alone, and combined joint kinematics and COM acceleration feedback. Additionally, pilot data was collected during external perturbations of an individual with SCI standing with functional neuromuscular stimulation (FNS), and the resulting joint kinematics and COM acceleration data was analyzed. Compared to the baseline case of maximal constant muscle excitations, the three control systems reduced the mean upper extremity loading by 51%, 43% and 56%, respectively against external force-pulse perturbations. Controller robustness was defined as the degradation in performance with increasing levels of input errors expected with clinical deployment of sensor-based feedback. At error levels typical for body-mounted inertial sensors, performance degradation due to sensor noise and placement were negligible. However, at typical tracking error levels, performance could degrade as much as 86% for joint kinematics feedback and 35% for COM acceleration feedback. Pilot data indicated that COM acceleration could be estimated with a few well-placed sensors and efficiently captures information related to movement synergies observed during perturbed bipedal standing following SCI. Overall, COM acceleration feedback may be a more feasible solution for control of standing with FNS given its superior robustness and small number of inputs required.

  11. Comparing joint kinematics and center of mass acceleration as feedback for control of standing balance by functional neuromuscular stimulation

    Directory of Open Access Journals (Sweden)

    Nataraj Raviraj

    2012-05-01

    Full Text Available Abstract Background The purpose of this study was to determine the comparative effectiveness of feedback control systems for maintaining standing balance based on joint kinematics or total body center of mass (COM acceleration, and assess their clinical practicality for standing neuroprostheses after spinal cord injury (SCI. Methods In simulation, controller performance was measured according to the upper extremity effort required to stabilize a three-dimensional model of bipedal standing against a variety of postural disturbances. Three cases were investigated: proportional-derivative control based on joint kinematics alone, COM acceleration feedback alone, and combined joint kinematics and COM acceleration feedback. Additionally, pilot data was collected during external perturbations of an individual with SCI standing with functional neuromuscular stimulation (FNS, and the resulting joint kinematics and COM acceleration data was analyzed. Results Compared to the baseline case of maximal constant muscle excitations, the three control systems reduced the mean upper extremity loading by 51%, 43% and 56%, respectively against external force-pulse perturbations. Controller robustness was defined as the degradation in performance with increasing levels of input errors expected with clinical deployment of sensor-based feedback. At error levels typical for body-mounted inertial sensors, performance degradation due to sensor noise and placement were negligible. However, at typical tracking error levels, performance could degrade as much as 86% for joint kinematics feedback and 35% for COM acceleration feedback. Pilot data indicated that COM acceleration could be estimated with a few well-placed sensors and efficiently captures information related to movement synergies observed during perturbed bipedal standing following SCI. Conclusions Overall, COM acceleration feedback may be a more feasible solution for control of standing with FNS given its

  12. Sequential injection approach for simultaneous determination of ultratrace plutonium and neptunium in urine with accelerator mass spectrometry

    DEFF Research Database (Denmark)

    Qiao, Jixin; Hou, Xiaolin; Roos, Per

    2013-01-01

    An analytical method was developed for simultaneous determination of ultratrace level plutonium (Pu) and neptunium (Np) using iron hydroxide coprecipitation in combination with automated sequential injection extraction chromatography separation and accelerator mass spectrometry (AMS) measurement...... show that preboiling and aging are important for obtaining high chemical yields for both Pu and Np, which is possibly related to the aggregation and adsorption behavior of organic substances contained in urine. Although the optimal condition for Np and Pu simultaneous determination requires 5-day aging...

  13. New accelerator mass spectrometry radiocarbon ages for the Mazama tephra layer from Kootenay National Park, British Columbia, Canada

    International Nuclear Information System (INIS)

    Hallett, D.J.; Hills, L.V.; Clague, J.J.

    1997-01-01

    Charcoal fragments recovered from the Mazama air-fall tephra layer in cores from Dog and Cobb lakes, Kootenay National Park, British Columbia, yielded accelerator mass spectrometry ages of 6720 ± 70 and 6760 ± 70 14 C years BP, respectively. These two new ages, together with other previously published radiocarbon ages on charcoal and twig fragments from Mazama air-fall deposits, indicate that the climatic eruption of Mount Mazama occurred 6730 ± 40 14 C years BP. (author)

  14. 14C accelerator mass spectrometry - applications in archaeology, biomedicine and in the atmospheric sciences

    International Nuclear Information System (INIS)

    Rom, W.

    1990-03-01

    Accelerator mass spectrometry (AMS) is superior to all other analytical techniques in its detection sensitivity of radiocarbon ( 14 C). It has therefore influenced or even laid down the foundations for applications in many fields of science. In the current work, various applications of 14 C AMS are presented through published articles for which the measurements were performed at the Vienna Environmental Research Accelerator (VERA). These articles are embedded into an in-depth discussion about characteristic features of the respective fields, emphasizing the broad range of issues which need to be considered in interdisciplinary research. In archaeology new 14 C dates on equipment of the Iceman ('Oetzi'), the world's oldest intact mummy, show reasonable agreement with dates previously obtained on the Iceman himself (3360-3100 BC). However, several botanical remains from the finding place clearly belong to other time periods, indicating that the discovery site of Oetzi has been used as a mountain pass 1500 yr earlier and also 2000 yr later. Dating on spruce logs from the world's oldest salt mines at Hallstatt, Austria provide evidence that salt mining started 1-2 centuries earlier than previously supposed, i.e. in the 14th to the 13th century BC. Recently, Bayesian mathematics is a frequently used tool in calibrating radiocarbon data. So-called vague or non-informative priors employed in this method may cause severe problems as shown by extensive computer simulations. In biomedicine problems in toxicology and in forensic medicine were investigated. Heterocyclic amines (HAs) are probably the epidemiologically most relevant class of mutagenic and carcinogenic substances since they are produced naturally in cooking protein-rich food. A study of 14 C labeled HAs (MeIQx and PhIP) in rodents and humans, one of the first studies using 14 C-labeled mutagens also in healthy human volunteers, severely calls in question the validity of animal models for assessing heterocyclic

  15. Accurate determination of 41Ca concentrations in spent resins from the nuclear industry by Accelerator Mass Spectrometry

    International Nuclear Information System (INIS)

    Nottoli, Emmanuelle; Bourlès, Didier; Bienvenu, Philippe; Labet, Alexandre; Arnold, Maurice; Bertaux, Maité

    2013-01-01

    The radiological characterisation of nuclear waste is essential for managing storage sites. Determining the concentration of Long‐Lived RadioNuclides (LLRN) is fundamental for their long-term management. This paper focuses on the measurement of low 41 Ca concentrations in ions exchange resins used for primary fluid purification in Pressurised Water Reactors (PWR). 41 Ca concentrations were successfully measured by Accelerator Mass Spectrometry (AMS) after the acid digestion of resin samples, followed by radioactive decontamination and isobaric suppression through successive hydroxide, carbonate, nitrate and final CaF 2 precipitations. Measured 41 Ca concentrations ranged from 0.02 to 0.03 ng/g, i.e. from 0.06 to 0.09 Bq/g. The 41 Ca/ 60 Co activity ratios obtained were remarkably reproducible and in good agreement with the current ratio used for resins management. - Highlights: • In the context of radioactive waste management, this study aimed at measuring 41 Ca in spent resins using Accelerator Mass Spectrometry. • A chemical treatment procedure was developed to quantitatively recover calcium in solution and selectively extract it. • Developed firstly on synthetic matrices, the chemical treatment procedure was then successfully applied to real resin samples. • Accelerator mass spectrometry allowed measuring concentrations of 41 Ca in spent resins as low as 0.02 ng/g of dry resin. • Final results are in agreement with current data used for spent resins management

  16. Integrated Vibration and Acceleration Testing to Reduce Payload Mass, Cost and Mission Risk, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a capability to provide integrated acceleration, vibration, and shock testing using a state-of-the-art centrifuge, allowing for the test of...

  17. Mass Producing Innovation: A Case Investigation on Why Accelerators Might Not Be a Paradox

    Directory of Open Access Journals (Sweden)

    Andrew Barnes

    2016-12-01

    Full Text Available There are a growing number of accelerator programmes designed to start and support innovative startup businesses. Many accelerators are increasing the size of their intakes, with some programmes now launching over 200 new companies per year. On first inspection the large numbers and consistent approach taken to accelerating the participating companies appears to be in conflict with producing innovative and disruptive companies. This paper uses Y Combinator as a single case study to investigate whether increasing the number of companies within a batch has resulted in longer or shorter timeframes for companies to achieve an exit (through acquisition or initial public offering. The paper finds that the timeframe for achieving an exit for Y Combinator companies is reducing, even while batch size has sharply increased. There is no statistically significant correlation between the cohort size and the initial money raised during the programme.    Keyword : Accelerators, Startups, Innovation

  18. Performance optimisation of a new-generation orthogonal-acceleration quadrupole-time-of-flight mass spectrometer.

    Science.gov (United States)

    Bristow, Tony; Constantine, Jill; Harrison, Mark; Cavoit, Fabien

    2008-04-01

    Orthogonal-acceleration quadrupole time-of-flight (oa-QTOF) mass spectrometers, employed for accurate mass measurement, have been commercially available for well over a decade. A limitation of the early instruments of this type was the narrow ion abundance range over which accurate mass measurements could be made with a high degree of certainty. Recently, a new generation of oa-QTOF mass spectrometers has been developed and these allow accurate mass measurements to be recorded over a much greater range of ion abundances. This development has resulted from new ion detection technology and improved electronic stability or by accurate control of the number of ions reaching the detector. In this report we describe the results from experiments performed to evaluate the mass measurement performance of the Bruker micrOTOF-Q, a member of the new-generation oa-QTOFs. The relationship between mass accuracy and ion abundance has been extensively evaluated and mass measurement accuracy remained stable (+/-1.5 m m/z units) over approximately 3-4 orders of magnitude of ion abundance. The second feature of the Bruker micrOTOF-Q that was evaluated was the SigmaFit function of the software. This isotope pattern-matching algorithm provides an exact numerical comparison of the theoretical and measured isotope patterns as an additional identification tool to accurate mass measurement. The smaller the value, the closer the match between theoretical and measured isotope patterns. This information is then employed to reduce the number of potential elemental formulae produced from the mass measurements. A relationship between the SigmaFit value and ion abundance has been established. The results from the study for both mass accuracy and SigmaFit were employed to define the performance criteria for the micrOTOF-Q. This provided increased confidence in the selection of elemental formulae resulting from accurate mass measurements.

  19. The mass-damped Riemann problem and the aerodynamic surface force calculation for an accelerating body

    International Nuclear Information System (INIS)

    Tan, Zhiqiang; Wilson, D.; Varghese, P.L.

    1997-01-01

    We consider an extension of the ordinary Riemann problem and present an efficient approximate solution that can be used to improve the calculations of aerodynamic forces on an accelerating body. The method is demonstrated with one-dimensional examples where the Euler equations and the body motion are solved in the non-inertial co-ordinate frame fixed to the accelerating body. 8 refs., 6 figs

  20. Isotopic Tracing of Fuel Components in Particulate Emissions from Diesel Engines using Accelerator Mass Spectrometry (AMS)

    International Nuclear Information System (INIS)

    Buchholz, B A; Mueller, C J; Garbak, J.

    2001-01-01

    Accelerator mass spectrometry (AMS) is an isotope-ratio measurement technique developed in the late 1970s for tracing long-lived radioisotopes (e.g., 14 C half life = 5760 y). The technique counts individual nuclei rather than waiting for their radioactive decay, allowing measurement of more than 100 low-level 14 C samples per day (Vogel et al, 1995). The LLNL AMS system is shown in Fig.1. The contemporary quantity of 14 C in living things ( 14 C/C = 1.2 x 10 -12 or 110 fmol 14 C/ g C) is highly elevated compared to the quantity of 14 C in petroleum-derived products. This isotopic elevation is sufficient to trace the fate of bio-derived fuel components in the emissions of an engine without the use of radioactive materials. If synthesis of a fuel component from biologically-derived source material is not feasible, another approach is to purchase 14 C-labeled material (e.g., dibutyl maleate (DBM)) and dilute it with petroleum-derived material to yield a contemporary level of 14 C. In each case, the virtual absence of 14 C in petroleum based fuels gives a very low 14 C background that makes this approach to tracing fuel components practical. Regulatory pressure to significantly reduce the particulate emissions from diesel engines is driving research into understanding mechanisms of soot formation. If mechanisms are understood, then combustion modeling can be used to evaluate possible changes in fuel formulation and suggest possible fuel components that can improve combustion and reduce PM emissions. The combustion paradigm assumes that large molecules break down into small components and then build up again during soot formation. AMS allows us to label specific fuel components, including oxygenates, trace the carbon atoms, and test this combustion modeling paradigm. Volatile and non-volatile organic fractions (VOF, NVOF) in the PM can be further separated. The VOF of the PM can be oxidized with catalysts in the exhaust stream to further decrease PM. The effectiveness

  1. Prospects for utilization of Electron Beam Accelerators (EBAs) for processing of food products

    International Nuclear Information System (INIS)

    Sarma, K.S.

    2014-01-01

    Radiation processing using gamma radiation and high energy electron beams has been in practice for more than three decades in the industry. Since gamma radiation has the ability of higher penetration in the material, large scale irradiators (mainly based on mega curies of 60 Co radioactive source) are successfully employed for treating bulk products in sterilization and food preservation applications. Electron beam, due to its low penetration, has been exploited exclusively for applications involving polymer modifications to irradiate thin finished end products like electrical cable insulations, heat shrinkable sheets, tubes, automobile tyres etc using high power EBAs (energies 0.5 MeV-4 MeV and powers around ∼100 kW). Out of around 2500 industrial EB units currently employed worldwide (with total installed power above 150 MWL 90% are in the low to medium energy range (0.5 MeV to 4 MeV) being used for polymer modifications. However, recent technological advances in the manufacturing sector of industrial high energy EBAs and product handling systems resulted in widening utilization of EB technology for applications involving bulk product irradiation

  2. Utilizing the Double-Precision Floating-Point Computing Power of GPUs for RSA Acceleration

    Directory of Open Access Journals (Sweden)

    Jiankuo Dong

    2017-01-01

    Full Text Available Asymmetric cryptographic algorithm (e.g., RSA and Elliptic Curve Cryptography implementations on Graphics Processing Units (GPUs have been researched for over a decade. The basic idea of most previous contributions is exploiting the highly parallel GPU architecture and porting the integer-based algorithms from general-purpose CPUs to GPUs, to offer high performance. However, the great potential cryptographic computing power of GPUs, especially by the more powerful floating-point instructions, has not been comprehensively investigated in fact. In this paper, we fully exploit the floating-point computing power of GPUs, by various designs, including the floating-point-based Montgomery multiplication/exponentiation algorithm and Chinese Remainder Theorem (CRT implementation in GPU. And for practical usage of the proposed algorithm, a new method is performed to convert the input/output between octet strings and floating-point numbers, fully utilizing GPUs and further promoting the overall performance by about 5%. The performance of RSA-2048/3072/4096 decryption on NVIDIA GeForce GTX TITAN reaches 42,211/12,151/5,790 operations per second, respectively, which achieves 13 times the performance of the previous fastest floating-point-based implementation (published in Eurocrypt 2009. The RSA-4096 decryption precedes the existing fastest integer-based result by 23%.

  3. Negative masses, even if isolated, imply self-acceleration, hence a catastrophic world

    International Nuclear Information System (INIS)

    Cavalleri, G.; Tonni, E.

    1997-01-01

    The conjecture of the existence of negative masses together with ordinary positive masses leads to runaway motions even if no self-reaction is considered. Pollard and Dunning-Davies have shown other constraints as a modification of the principle of least action and that negative masses can only exist at negative temperature, and must be adiabatically separate from positive masses. They show here that the self-reaction on a single isolated negative mass implies a runaway motion. Consequently, the consideration of self-fields and relevant self-reaction excludes negative masses even if isolated

  4. Development of aluminium-26 accelerator mass spectrometry for biological and toxicological applications

    Science.gov (United States)

    Barker, James

    Aluminium is now recognised as a toxic element. Its accumulation in the body leads to serious conditions in renal failure patients on haemodialysis, and there is suspected involvement in the aetiology of Alzheimer's Disease. Although uptake from food and water are important exposure pathways, there is so far little quantitative knowledge about gastrointestinal absorption of aluminium, its general speciation in the blood or its metabolism. This is partly because seven of aluminium's eight radioisotopes have half-lives too short to conduct accurate biochemical studies. The use of [67]Ga as a tracer for aluminium begs the question of its biochemical similarity. Radiotracer studies on aluminium are possible with [26]Al (T[2] = 716,000 years), but a comparatively large amount of this scarce and expensive radioisotope (price ca. 50 pence per Bq) would be needed to measure by normal counting techniques. Use of conventional mass spectrometry is impracticable due to [26]Mg interference (comprises 11 % of total stable Mg and inherent in all biological or environmental samples), but high energy Accelerator Mass Spectrometry (A.M.S.), resulting in some fully-stripped ions (Al[13+], Mg[12+]) , potentially overcomes this problem. [26]Al is particularly attractive in human toxicology because of its negligible natural abundance and low radiological hazard. We have used the 20 MV tandem Van De Graaff accelerator (S.E.R.C. Daresbury) to conduct 1A1 A.M.S. measurements in biological media. Stable currents of ALQ[-](100 nA for > 5 hours) were obtained from a modified Middleton ion source, using alumina/silver ion source preparations of 50 mug Al. [26]Al is unambiguously identified from and [26]Mg [27]AlO[-] is repeatedly measured on a Faray Cup placed in the beamline after adjusting the ion source magnet. Linear calibration (C.V. range tested ([26]Al/[27]Al ratios from 10[-6] to 10[-11]) and a detection limit (2?) of ca. 7 x 10[-18]g (5 nBq) [26]Al ratio [26]Al/[27]Al limit of 1.4 x

  5. Gene Amplification on Demand Accelerates Cellobiose Utilization in Engineered Saccharomyces cerevisiae.

    Science.gov (United States)

    Oh, Eun Joong; Skerker, Jeffrey M; Kim, Soo Rin; Wei, Na; Turner, Timothy L; Maurer, Matthew J; Arkin, Adam P; Jin, Yong-Su

    2016-06-15

    Efficient microbial utilization of cellulosic sugars is essential for the economic production of biofuels and chemicals. Although the yeast Saccharomyces cerevisiae is a robust microbial platform widely used in ethanol plants using sugar cane and corn starch in large-scale operations, glucose repression is one of the significant barriers to the efficient fermentation of cellulosic sugar mixtures. A recent study demonstrated that intracellular utilization of cellobiose by engineered yeast expressing a cellobiose transporter (encoded by cdt-1) and an intracellular β-glucosidase (encoded by gh1-1) can alleviate glucose repression, resulting in the simultaneous cofermentation of cellobiose and nonglucose sugars. Here we report enhanced cellobiose fermentation by engineered yeast expressing cdt-1 and gh1-1 through laboratory evolution. When cdt-1 and gh1-1 were integrated into the genome of yeast, the single copy integrant showed a low cellobiose consumption rate. However, cellobiose fermentation rates by engineered yeast increased gradually during serial subcultures on cellobiose. Finally, an evolved strain exhibited a 15-fold-higher cellobiose fermentation rate. To identify the responsible mutations in the evolved strain, genome sequencing was performed. Interestingly, no mutations affecting cellobiose fermentation were identified, but the evolved strain contained 9 copies of cdt-1 and 23 copies of gh1-1 We also traced the copy numbers of cdt-1 and gh1-1 of mixed populations during the serial subcultures. The copy numbers of cdt-1 and gh1-1 in the cultures increased gradually with similar ratios as cellobiose fermentation rates of the cultures increased. These results suggest that the cellobiose assimilation pathway (transport and hydrolysis) might be a rate-limiting step in engineered yeast and copies of genes coding for metabolic enzymes might be amplified in yeast if there is a growth advantage. This study indicates that on-demand gene amplification might be an

  6. What can we learn from the self-attraction and loading fingerprints about pre-GRACE mass-loss acceleration from Greenland and Antarctica?

    Science.gov (United States)

    Davis, J. L.; Vinogradova, N. T.

    2017-12-01

    Tide-gauge records from the North Atlantic reveal significant acceleration in sea level starting in the late 20th century. We have analyzed the tide-gauge data using a model in which the accelerations are assumed to be zero prior to 1990. The estimated accelerations range from -1 to +3 m cy-2 and exhibit a systematic spatial variability. Davis and Vinogradova [2017] demonstrated that to model this variability in sea-level acceleration requires contributions from several distinct physical processes: accelerated mass loss from the Greenland and Antarctic Ice Sheets and acceleration associated with ocean circulation and heat uptake. Atmospheric pressure also contributes to the observed changes in sea level, at a much smaller amplitude. Because we are focusing on sea-level accelerations (i.e., sea-level rate changes), the contribution from Glacial Isostatic Adjustment (GIA) is negligible. Modeling of observed sea-level acceleration is achieved using external constraints for the important physical processes. Using GRACE results, we can calculate the sea-level "fingerprints" for Greenland and Antarctica associated with mass loading and gravitational perturbations. For the North Atlantic, Greenland induces a significant spatial variation in sea-level change—dominated by the solid-Earth response to the mass loss—whereas Antarctica contributes a spatially constant acceleration. The observations prefer a scaling of the solid-Earth/gravitational response, and we present the implications of this result for ice-mass changes prior to the onset of GRACE observations (2002-3).

  7. Outcomes and Resource Utilization of Endoscopic Mass-Closure Technique for Laryngeal Clefts.

    Science.gov (United States)

    Balakrishnan, Karthik; Cheng, Esther; de Alarcon, Alessandro; Sidell, Douglas R; Hart, Catherine K; Rutter, Michael J

    2015-07-01

    To compare resource utilization and clinical outcomes between endoscopic mass-closure and open techniques for laryngeal cleft repair. Case series with chart review. Tertiary academic children's hospital. Pediatric patients undergoing repair for Benjamin-Inglis type 1-3 laryngeal clefts over a 15-year period. All 20 patients undergoing endoscopic repair were included. Eight control patients undergoing open repair were selected using matching by age and cleft type. Demographic, clinical, and resource utilization data were collected. Twenty-eight patients were included (20 endoscopic, 8 open). Mean age, rates of tracheostomy and vocal fold immobility, and distribution of cleft types were not different between the 2 groups (all P > .2). Mean operative time (P = .004) and duration of hospital stay (P group. All repairs were intact in both groups at final postoperative endoscopy. Rates of persistent laryngeal penetration or aspiration on swallow study were not different between groups (P = 1.000), although results were available for only 11 patients. Endoscopic laryngeal cleft repair using a mass-closure technique provides a durable result while requiring significantly shorter operative times and hospital stays than open repair and avoiding the potential morbidity of laryngofissure. However, open repair may allow the simultaneous performance of other airway reconstructive procedures and may be a useful salvage technique when endoscopic repair fails. Postoperative swallowing results require further study. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

  8. Acceleration of Gas Flow Simulations in Dual-Continuum Porous Media Based on the Mass-Conservation POD Method

    KAUST Repository

    Wang, Yi

    2017-09-12

    Reduced-order modeling approaches for gas flow in dual-porosity dual-permeability porous media are studied based on the proper orthogonal decomposition (POD) method combined with Galerkin projection. The typical modeling approach for non-porous-medium liquid flow problems is not appropriate for this compressible gas flow in a dual-continuum porous media. The reason is that non-zero mass transfer for the dual-continuum system can be generated artificially via the typical POD projection, violating the mass-conservation nature and causing the failure of the POD modeling. A new POD modeling approach is proposed considering the mass conservation of the whole matrix fracture system. Computation can be accelerated as much as 720 times with high precision (reconstruction errors as slow as 7.69 × 10−4%~3.87% for the matrix and 8.27 × 10−4%~2.84% for the fracture).

  9. Acceleration of Gas Flow Simulations in Dual-Continuum Porous Media Based on the Mass-Conservation POD Method

    KAUST Repository

    Wang, Yi; Sun, Shuyu; Yu, Bo

    2017-01-01

    Reduced-order modeling approaches for gas flow in dual-porosity dual-permeability porous media are studied based on the proper orthogonal decomposition (POD) method combined with Galerkin projection. The typical modeling approach for non-porous-medium liquid flow problems is not appropriate for this compressible gas flow in a dual-continuum porous media. The reason is that non-zero mass transfer for the dual-continuum system can be generated artificially via the typical POD projection, violating the mass-conservation nature and causing the failure of the POD modeling. A new POD modeling approach is proposed considering the mass conservation of the whole matrix fracture system. Computation can be accelerated as much as 720 times with high precision (reconstruction errors as slow as 7.69 × 10−4%~3.87% for the matrix and 8.27 × 10−4%~2.84% for the fracture).

  10. Center of Mass Acceleration Feedback Control of Standing Balance by Functional Neuromuscular Stimulation against External Postural Perturbations

    Science.gov (United States)

    Nataraj, Raviraj; Audu, Musa L.; Triolo, Ronald J.

    2013-01-01

    This study investigated the use of center of mass (COM) acceleration feedback for improving performance of a functional neuromuscular stimulation (FNS) control system to restore standing function to a subject with complete, thoracic-level spinal cord injury (SCI). The approach for linearly relating changes in muscle stimulation to changes in COM acceleration was verified experimentally and subsequently produced data to create an input-output map driven by sensor feedback. The feedback gains were systematically tuned to reduce upper extremity (UE) loads applied to an instrumented support device while resisting external postural disturbances. Total body COM acceleration was accurately estimated (> 89% variance explained) using three-dimensional (3-D) outputs of two accelerometers mounted on the pelvis and torso. Compared to constant muscle stimulation employed clinically, feedback control of stimulation reduced UE loading by 33%. COM acceleration feedback is advantageous in constructing a standing neuroprosthesis since it provides the basis for a comprehensive control synergy about a global, dynamic variable and requires minimal instrumentation. Future work should include tuning and testing the feedback control system during functional reaching activity that is more indicative of activities of daily living. PMID:22987499

  11. Determination of Aspartame and Caffeine in Carbonated Beverages Utilizing Electrospray Ionization-Mass Spectrometry

    Science.gov (United States)

    Bergen, H. Robert, III; Benson, Linda M.; Naylor, Stephen

    2000-10-01

    Mass spectrometry has undergone considerable changes in the past decade. The advent of "soft ionization" techniques such as electrospray ionization (ESI) affords the direct analysis of very polar molecules without need for the complex inefficient derivatization procedures often required in GC-MS. These ionization techniques make possible the direct mass spectral analysis of polar nonvolatile molecules such as DNA and proteins, which previously were difficult or impossible to analyze by MS. Compounds that readily take on a charge (acids and bases) lend themselves to ESI-MS analysis, whereas compounds that do not readily accept a charge (e.g. sugars) are often not seen or are seen only as inefficient adducts (e.g., M+Na+). To gain exposure to this state-of-the-art analytical procedure, high school students utilize ESI-MS in an analysis of aspartame and caffeine. They dilute a beverage sample and inject the diluted sample into the ESI-MS. The lab is procedurally simple and the results clearly demonstrate the potential and limitations of ESI-coupled mass spectrometry. Depending upon the instructional goals, the outlined procedures can be used to quantify the content of caffeine and aspartame in beverages or to understand the capabilities of electrospray ionization.

  12. Accelerated modern human?induced species losses: Entering the sixth mass extinction

    OpenAIRE

    Ceballos, Gerardo; Ehrlich, Paul R.; Barnosky, Anthony D.; Garc?a, Andr?s; Pringle, Robert M.; Palmer, Todd M.

    2015-01-01

    The oft-repeated claim that Earth?s biota is entering a sixth ?mass extinction? depends on clearly demonstrating that current extinction rates are far above the ?background? rates prevailing between the five previous mass extinctions. Earlier estimates of extinction rates have been criticized for using assumptions that might overestimate the severity of the extinction crisis. We assess, using extremely conservative assumptions, whether human activities are causing a mass extinction. First, we...

  13. Optimizing Mass Spectrometry Analyses: A Tailored Review on the Utility of Design of Experiments.

    Science.gov (United States)

    Hecht, Elizabeth S; Oberg, Ann L; Muddiman, David C

    2016-05-01

    Mass spectrometry (MS) has emerged as a tool that can analyze nearly all classes of molecules, with its scope rapidly expanding in the areas of post-translational modifications, MS instrumentation, and many others. Yet integration of novel analyte preparatory and purification methods with existing or novel mass spectrometers can introduce new challenges for MS sensitivity. The mechanisms that govern detection by MS are particularly complex and interdependent, including ionization efficiency, ion suppression, and transmission. Performance of both off-line and MS methods can be optimized separately or, when appropriate, simultaneously through statistical designs, broadly referred to as "design of experiments" (DOE). The following review provides a tutorial-like guide into the selection of DOE for MS experiments, the practices for modeling and optimization of response variables, and the available software tools that support DOE implementation in any laboratory. This review comes 3 years after the latest DOE review (Hibbert DB, 2012), which provided a comprehensive overview on the types of designs available and their statistical construction. Since that time, new classes of DOE, such as the definitive screening design, have emerged and new calls have been made for mass spectrometrists to adopt the practice. Rather than exhaustively cover all possible designs, we have highlighted the three most practical DOE classes available to mass spectrometrists. This review further differentiates itself by providing expert recommendations for experimental setup and defining DOE entirely in the context of three case-studies that highlight the utility of different designs to achieve different goals. A step-by-step tutorial is also provided.

  14. Similar muscles contribute to horizontal and vertical acceleration of center of mass in forward and backward walking: implications for neural control

    Science.gov (United States)

    Jansen, Karen; De Groote, Friedl; Massaad, Firas; Meyns, Pieter; Jonkers, Ilse

    2012-01-01

    Leg kinematics during backward walking (BW) are very similar to the time-reversed kinematics during forward walking (FW). This suggests that the underlying muscle activation pattern could originate from a simple time reversal, as well. Experimental electromyography studies have confirmed that this is the case for some muscles. Furthermore, it has been hypothesized that muscles showing a time reversal should also exhibit a reversal in function [from accelerating the body center of mass (COM) to decelerating]. However, this has not yet been verified in simulation studies. In the present study, forward simulations were used to study the effects of muscles on the acceleration of COM in FW and BW. We found that a reversal in function was indeed present in the muscle control of the horizontal movement of COM (e.g., tibialis anterior and gastrocnemius). In contrast, muscles' antigravity contributions maintained their function for both directions of movement. An important outcome of the present study is therefore that similar muscles can be used to achieve opposite functional demands at the level of control of the COM when walking direction is reversed. However, some muscles showed direction-specific contributions (i.e., dorsiflexors). We concluded that the changes in muscle contributions imply that a simple time reversal would be insufficient to produce BW from FW. We therefore propose that BW utilizes extra elements, presumably supraspinal, in addition to a common spinal drive. These additions are needed for propulsion and require a partial reconfiguration of lower level common networks. PMID:22423005

  15. A dietary supplementation with leucine and antioxidants is capable to accelerate muscle mass recovery after immobilization in adult rats.

    Directory of Open Access Journals (Sweden)

    Isabelle Savary-Auzeloux

    Full Text Available Prolonged inactivity induces muscle loss due to an activation of proteolysis and decreased protein synthesis; the latter is also involved in the recovery of muscle mass. The aim of the present work was to explore the evolution of muscle mass and protein metabolism during immobilization and recovery and assess the effect of a nutritional strategy for counteracting muscle loss and facilitating recovery. Adult rats (6-8 months were subjected to unilateral hindlimb casting for 8 days (I0-I8 and then permitted to recover for 10 to 40 days (R10-R40. They were fed a Control or Experimental diet supplemented with antioxidants/polyphenols (AOX (I0 to I8, AOX and leucine (AOX + LEU (I8 to R15 and LEU alone (R15 to R40. Muscle mass, absolute protein synthesis rate and proteasome activities were measured in gastrocnemius muscle in casted and non-casted legs in post prandial (PP and post absorptive (PA states at each time point. Immobilized gastrocnemius protein content was similarly reduced (-37% in both diets compared to the non-casted leg. Muscle mass recovery was accelerated by the AOX and LEU supplementation (+6% AOX+LEU vs. Control, P<0.05 at R40 due to a higher protein synthesis both in PA and PP states (+23% and 31% respectively, Experimental vs. Control diets, P<0.05, R40 without difference in trypsin- and chymotrypsin-like activities between diets. Thus, this nutritional supplementation accelerated the recovery of muscle mass via a stimulation of protein synthesis throughout the entire day (in the PP and PA states and could be a promising strategy to be tested during recovery from bed rest in humans.

  16. On the identification of carbonaceous aerosols via 14C accelerator mass spectrometry, and laser microprobe mass spectrometry

    International Nuclear Information System (INIS)

    Currie, L.A.; Fletcher, R.A.; Klouda, G.A.

    1987-01-01

    Carbon isotopic measurements ( 12 C, 14 C), derived from chemical measurements of total carbon plus AMS measurements of 14 C/ 12 C have become an accepted means for estimating fossil and contemporary carbon source contributions to atmospheric carbon. Because of the limited sensitivity of these techniques, however, such measurements are restricted to 'bulk' samples comprising at least 10-100 μg of carbon. Laser microprobe mass spectrometry (LMMS) offers an important complementary opportunity to investigate the chemical nature of individual particles as small as 0.1 μm in diameter. Although there is little hope to measure 14 C/ 12 C in such small samples, the compositional and structural information available with the laser microprobe is of interest for possible source discrimination. Also, the analysis of individual particles, which may reflect individual sources, yields significant potential increases in spatial, temporal and source resolution, in comparison to bulk sample analysis. Results of our exploratory investigation of known sources of carbonaceous particles, using LMMS, are presented. By applying multivariate techniques to laser mass spectra of soot from the combustion of heptane and wood, we found striking differences in the alkali metals (notably potassium) in the positive ion mass spectra. For ambient particles, 14 C has proved to be a crucial adjunct for the development and validation of the LMMS approach to single particle source assignment via carbon cluster pattern recognition. The combined techniques offer great promise for objective modeling (number and types of carbon sources) and for extension of the dichotomous carbon apportionment (fossil, contemporary) to subclasses such as soot from wood and agricultural burning, and that from coal and petroleum combustion. (orig.)

  17. First-year progress on research and development of a mass accelerator (MAID) as a driver for impact fusion, May 6, 1981-May 5, 1982

    International Nuclear Information System (INIS)

    1982-01-01

    The objective of this program is to construct a small scale mass accelerator consisting of 10 plasma discharge modules, and perform experiments and analysis with the system so that reliable scaling laws can be obtained for the device. The effort is directed to determining whether a large scale version of such a plasma driven mass accelerator could be used as a driver for inertial fusion, or other energy-related applications

  18. Measurements of natural levels of 14C in human's and rat's tissues by accelerator mass spectrometry in Korea

    International Nuclear Information System (INIS)

    Cho, S.Y.; Khu, H.J.; Kang, J.H.; Yoon, M.Y.; Kim, J.C.

    2005-01-01

    Accelerator mass spectrometry (AMS) is the most sensitive, safe and precise analytical method for quantifying long-lived isotope in biomedical research with animals as well as human beings. In Korea, AMS Laboratory has been operating successfully for years measuring especially archaeological samples for 14 C dating. In this year, a biological sample pretreatment facility was setup to work on biomedical applications. As a preliminary study, we have measured the natural background levels of 14 C in tissues and blood of humans and rats have been measured. The results were agreed with the other reported levels and gave stable and reproducible results within 1-2%. (author)

  19. Advantages of utilizing DMD based rapid manufacturing systems in mass customization applications

    Science.gov (United States)

    El-Siblani, A.

    2010-02-01

    The Use of DMD based Rapid Manufacturing Systems has proven to be very advantageous in the production of highly accurate plastic based components for use in mass customization market such as hearing aids, and dental markets. The voxelization process currently afforded with the DLP technology eliminates any layering effect associated with all existing additive Rapid Manufacturing technologies. The smooth accurate surfaces produced in an additive process utilizing DLP technology, through the voxelization approach, allow for the production of custom finished products. The implementation of DLP technology in rapid prototyping and rapid manufacturing systems allow for the usage of highly viscous photopolymer based liquid and paste composites for rapid manufacturing that could not be used in any other additive process prior to implementation of DLP technology in RP and RM systems. It also allowed for the greater throughput in production without sacrificing quality and accuracy.

  20. Biological Effects of Particles with Very High Energy Deposition on Mammalian Cells Utilizing the Brookhaven Tandem Van de Graaff Accelerator

    Science.gov (United States)

    Saha, Janapriya; Cucinotta, Francis A.; Wang, Minli

    2013-01-01

    High LET radiation from GCR (Galactic Cosmic Rays) consisting mainly of high charge and energy (HZE) nuclei and secondary protons and neutrons, and secondaries from protons in SPE (Solar Particle Event) pose a major health risk to astronauts due to induction of DNA damage and oxidative stress. Experiments with high energy particles mimicking the space environment for estimation of radiation risk are being performed at NASA Space Radiation Laboratory at BNL. Experiments with low energy particles comparing to high energy particles of similar LET are of interest for investigation of the role of track structure on biological effects. For this purpose, we report results utilizing the Tandem Van de Graaff accelerator at BNL. The primary objective of our studies is to elucidate the influence of high vs low energy deposition on track structure, delta ray contribution and resulting biological responses. These low energy ions are of special relevance as these energies may occur following absorption through the spacecraft and shielding materials in human tissues and nuclear fragments produced in tissues by high energy protons and neutrons. This study will help to verify the efficiency of these low energy particles and better understand how various cell types respond to them.

  1. phpMs: A PHP-Based Mass Spectrometry Utilities Library.

    Science.gov (United States)

    Collins, Andrew; Jones, Andrew R

    2018-03-02

    The recent establishment of cloud computing, high-throughput networking, and more versatile web standards and browsers has led to a renewed interest in web-based applications. While traditionally big data has been the domain of optimized desktop and server applications, it is now possible to store vast amounts of data and perform the necessary calculations offsite in cloud storage and computing providers, with the results visualized in a high-quality cross-platform interface via a web browser. There are number of emerging platforms for cloud-based mass spectrometry data analysis; however, there is limited pre-existing code accessible to web developers, especially for those that are constrained to a shared hosting environment where Java and C applications are often forbidden from use by the hosting provider. To remedy this, we provide an open-source mass spectrometry library for one of the most commonly used web development languages, PHP. Our new library, phpMs, provides objects for storing and manipulating spectra and identification data as well as utilities for file reading, file writing, calculations, peptide fragmentation, and protein digestion as well as a software interface for controlling search engines. We provide a working demonstration of some of the capabilities at http://pgb.liv.ac.uk/phpMs .

  2. Effects of rotation on MHD flow past an accelerated isothermal vertical plate with heat and mass diffusion

    Directory of Open Access Journals (Sweden)

    Muthucumaraswamy R.

    2010-01-01

    Full Text Available An exact analysis of rotation effects on unsteady flow of an incompressible and electrically conducting fluid past a uniformly accelerated infinite isothermal vertical plate, under the action of transversely applied magnetic field has been presented. The plate temperature is raised to Tw and the concentration level near the plate is also raised to C′w . The dimensionless governing equations are solved using Laplace-transform technique. The velocity profiles, temperature and concentration are studied for different physical parameters like thermal Grashof number, mass Grashof number, Schmidt number, Prandtl number and time. It is observed that the velocity increases with increasing values of thermal Grashof number or mass Grashof number. It is also observed that the velocity increases with decreasing magnetic field parameter.

  3. Accurate determination of 129I concentrations and 129I/137Cs ratios in spent nuclear resins by Accelerator Mass Spectrometry

    International Nuclear Information System (INIS)

    Nottoli, Emmanuelle; Bienvenu, Philippe; Labet, Alexandre; Bourlès, Didier; Arnold, Maurice; Bertaux, Maité

    2014-01-01

    Determining long-lived radionuclide concentrations in radioactive waste has fundamental implications for the long-term management of storage sites. This paper focuses on the measurement of low 129 I contents in ion exchange resins used for primary fluid purification in Pressurised Water Reactors (PWR). Iodine-129 concentrations were successfully determined using Accelerator Mass Spectrometry (AMS) following a chemical procedure which included (1) acid digestion of resin samples in HNO 3 /HClO 4 , (2) radioactive decontamination by selective iodine extraction using a new chromatographic resin (CL Resin), and (3) AgI precipitation. Measured 129 I concentrations ranged from 4 to 12 ng/g, i.e. from 0.03 to 0.08 Bq/g. The calculation of 129 I/ 137 Cs activity ratios used for routine waste management produced values in agreement with the few available data for PWR resin samples. - Highlights: • In the context of radioactive waste management, this study aimed at measuring 129 I in spent resins using accelerator mass spectrometry. • The treatment procedure included microwave acid digestion of samples, iodine extraction by CL resins and AgI precipitation. • Developed first on synthetic matrices, the chemical treatment procedure was then successfully applied to real resin samples. • 129 I concentrations ranged from 4 to 12 ng/g of dry resin. • Results are in agreement with previous measurements and support reference values currently used for nuclear resin management

  4. A study for the fabulously of introducing an acceleration mass spectrometer facility (ABMs) for carbon-14 applications

    International Nuclear Information System (INIS)

    Aly, A.I.M.; Comsan, N.; Sadek, M.

    2004-01-01

    In this work a study was conducted to show the importance and feasibility of introducing an accelerating mass spectrometer facility for carbon-14 analysis in the environmental levels. The different applications of Carbon-14 (e.g. dating and identification of food additives of synthetic origin) are discussed. There are two methods for C- 14 measurements, beta decay counting and accelerator mass spectrometry (AMS). The beta decay method requires gram quantities of the sample carbon, compared to few milligram quantities in case of AMS method. The Central Lab. for Environmental Isotope Hydrology of the National Center for Nuclear Safety and Radiation Control has a Carbon-14 analysis facility based on beta decay counting using a liquid scintillation counter after sample preparation in the form of benzene through rather complicated chemical conversion steps. This strongly limits the capacity of the laboratory to about 100-150 samples per year. Also, the amount of sample required limits our expansion for some very important applications like dating of archaeological small samples and especially old bone samples which normally have a low concentration of organic compounds. These applications are only possible by using the AMS method. For some applications only AMS could be used e.g measuring C-14 in atmospheric gases such as methane and carbon dioxide is virtually impossible using decay counting but quite feasible with AMS. The importance of purchasing an AMS facility or upgrading the existing accelerator is discussed in view of the shortage of such a facility in Africa and the Middle East. Acquiring an AMS in Egypt will make it possible to accurately date the Egyptian antiquities and to act as a regional laboratory and to enter into new applications where the amount of sample is limiting

  5. Instruments for radiation measurement in life sciences (4). 7. Application of accelerator mass spectrometry for drug development. Human mass balance studies at discovery stage

    International Nuclear Information System (INIS)

    Miyaoka, Teiji

    2005-01-01

    Following the recent trend of Position Paper issued from European Agency for the Evaluation of Medicinal Products on the non-clinical safety studies to support clinical trials with a single micro dose, human mass balance studies at discovery stages were made with special interest in using AMS (accelerator mass spectrometry) with a small amount of hot (radioisotope-labeled) drug. This method was found to be effective for the purpose of screening in the clinical study for pharmaceutical development. To show an example of the test, 5, 50, 500μg/body of C14-ARA (α1A adrenoreceptor antagonist, 50 nCi or 1.85 kBq/body/dose) were given (cross over) to several persons to be inspected and C14-quantity in the blood plasma or urine was determined with AMS until after 168 hours or so. The results of the present experiment demonstrate that human mass balance study at discovery stages is possible with ultra high sensitive measuring systems such as AMS and PET (positron emission tomography). (S. Ohno)

  6. Turnaround radius in an accelerated universe with quasi-local mass

    Energy Technology Data Exchange (ETDEWEB)

    Faraoni, Valerio; Lapierre-Léonard, Marianne; Prain, Angus, E-mail: vfaraoni@ubishops.ca, E-mail: mlapierre12@ubishops.ca, E-mail: angusprain@gmail.com [Physics Department, Bishop' s University, 2600 College Street, Sherbrooke, Québec, J1M 1Z7 Canada (Canada)

    2015-10-01

    We apply the Hawking-Hayward quasi-local energy construct to obtain in a rigorous way the turnaround radius of cosmic structures in General Relativity. A splitting of this quasi-local mass into local and cosmological parts describes the interplay between local attraction and cosmological expansion.

  7. Turnaround radius in an accelerated universe with quasi-local mass

    International Nuclear Information System (INIS)

    Faraoni, Valerio; Lapierre-Léonard, Marianne; Prain, Angus

    2015-01-01

    We apply the Hawking-Hayward quasi-local energy construct to obtain in a rigorous way the turnaround radius of cosmic structures in General Relativity. A splitting of this quasi-local mass into local and cosmological parts describes the interplay between local attraction and cosmological expansion

  8. Speciation analysis of 129I in seawater using coprecipitation and accelerator mass spectrometry and its applications

    DEFF Research Database (Denmark)

    Xing, Shan; Hou, Xiaolin; Aldahan, Ala

    2017-01-01

    Speciation analysis of long-lived 129I in seawater can provide useful information on the source of water masses. This paper presents an improved method for speciation analysis of 129I based on coprecipitation of iodide as AgI with Ag2SO3 and AgCl. By adding a small amount of 127I carrier...

  9. Accelerated modern human–induced species losses: Entering the sixth mass extinction

    Science.gov (United States)

    Ceballos, Gerardo; Ehrlich, Paul R.; Barnosky, Anthony D.; García, Andrés; Pringle, Robert M.; Palmer, Todd M.

    2015-01-01

    The oft-repeated claim that Earth’s biota is entering a sixth “mass extinction” depends on clearly demonstrating that current extinction rates are far above the “background” rates prevailing between the five previous mass extinctions. Earlier estimates of extinction rates have been criticized for using assumptions that might overestimate the severity of the extinction crisis. We assess, using extremely conservative assumptions, whether human activities are causing a mass extinction. First, we use a recent estimate of a background rate of 2 mammal extinctions per 10,000 species per 100 years (that is, 2 E/MSY), which is twice as high as widely used previous estimates. We then compare this rate with the current rate of mammal and vertebrate extinctions. The latter is conservatively low because listing a species as extinct requires meeting stringent criteria. Even under our assumptions, which would tend to minimize evidence of an incipient mass extinction, the average rate of vertebrate species loss over the last century is up to 100 times higher than the background rate. Under the 2 E/MSY background rate, the number of species that have gone extinct in the last century would have taken, depending on the vertebrate taxon, between 800 and 10,000 years to disappear. These estimates reveal an exceptionally rapid loss of biodiversity over the last few centuries, indicating that a sixth mass extinction is already under way. Averting a dramatic decay of biodiversity and the subsequent loss of ecosystem services is still possible through intensified conservation efforts, but that window of opportunity is rapidly closing. PMID:26601195

  10. Accelerated modern human-induced species losses: Entering the sixth mass extinction.

    Science.gov (United States)

    Ceballos, Gerardo; Ehrlich, Paul R; Barnosky, Anthony D; García, Andrés; Pringle, Robert M; Palmer, Todd M

    2015-06-01

    The oft-repeated claim that Earth's biota is entering a sixth "mass extinction" depends on clearly demonstrating that current extinction rates are far above the "background" rates prevailing between the five previous mass extinctions. Earlier estimates of extinction rates have been criticized for using assumptions that might overestimate the severity of the extinction crisis. We assess, using extremely conservative assumptions, whether human activities are causing a mass extinction. First, we use a recent estimate of a background rate of 2 mammal extinctions per 10,000 species per 100 years (that is, 2 E/MSY), which is twice as high as widely used previous estimates. We then compare this rate with the current rate of mammal and vertebrate extinctions. The latter is conservatively low because listing a species as extinct requires meeting stringent criteria. Even under our assumptions, which would tend to minimize evidence of an incipient mass extinction, the average rate of vertebrate species loss over the last century is up to 100 times higher than the background rate. Under the 2 E/MSY background rate, the number of species that have gone extinct in the last century would have taken, depending on the vertebrate taxon, between 800 and 10,000 years to disappear. These estimates reveal an exceptionally rapid loss of biodiversity over the last few centuries, indicating that a sixth mass extinction is already under way. Averting a dramatic decay of biodiversity and the subsequent loss of ecosystem services is still possible through intensified conservation efforts, but that window of opportunity is rapidly closing.

  11. Body Mass Index Trajectories and Healthcare Utilization in Young and Middle-aged Adults.

    Science.gov (United States)

    Elrashidi, Muhamad Y; Jacobson, Debra J; St Sauver, Jennifer; Fan, Chun; Lynch, Brian A; Rutten, Lila J Finney; Ebbert, Jon O

    2016-01-01

    The obesity epidemic is a significant public health issue with adverse impact on health and costs. Applying a life-course perspective to obesity may advance our understanding of the influence of obesity over time on patterns of healthcare utilization in young and middle-aged United States (US) adults.We identified baseline body mass index (BMI) and BMI trajectories, and assessed their association with outpatient visits, emergency department (ED) visits, and hospitalizations in a well-defined population of young and middle-aged US adults.Using the Rochester Epidemiology Project resources, we conducted a retrospective cohort study of adults (N = 23,254) aged 18 to 44 years, with at least 3 BMI measurements, residing in Olmsted County, MN from January 1, 2005 through December 31, 2012.We observed that 27.5% of the population was obese. Four BMI trajectories were identified. Compared to under/normal weight, obese class III adults had higher risk of outpatient visits (adjusted rate ratio [RR], 1.86; 95% confidence intervals [CIs], 1.67-2,08), ED visits (adjusted RR, 3.02; 95% CI, 2.74-3.34), and hospitalizations (adjusted RR, 1.67; 95% CI, 1.59-1.75). BMI trajectory was positively associated with ED visits after adjustment for age, sex, race, and Charlson Comorbidity Index (P young and middle-aged US adults, baseline BMI is positively associated with outpatient visits, ED visits, and hospitalizations, while BMI trajectory is positively associated with ED visits. These findings extend our understanding of the longitudinal influence of obesity on healthcare utilization in early to mid-adulthood.

  12. Utilization of marble from Bejui mine - Currais Novos/RN in ceramic mass

    International Nuclear Information System (INIS)

    Farias, D.S.U. de; Souza, M.M. de; Almeida, A.B.D. de; Lima, T.C. de; Nobrega, L.F.P. de M.; Mendes, L.B.

    2016-01-01

    Mining in Mine Brejui, in Currais Novos - RN, is related to the extraction of scheelite, however the marble of the region is not fully tapped. Aiming to provide a utility to this carbonate rock very abundant in the Serido region, this work is to evaluate, from its chemical and other tests, the addition of marble in the ceramic mass. For the analysis, the samples were collected, then comminuted and sieved to #200 and, right after, characterized by fluorescence X-ray method (FRX). The results indicate a high concentration of CaO (95%), a flux element, and very low content of Fe_2O_3 and SO_3 (less than 0.6%). After produced the samples, there were performed the water absorption tests and linear shrinkage, which has indicate satisfactory results and classifying them as porcelain. Therefore, with the significant potential of the marble, other laboratory tests may be performed to analyze its incorporation in the formulation of ceramic bodies, being economically viable and adding proper use and commercial value to the rock. (author)

  13. Postmortem interval estimation: a novel approach utilizing gas chromatography/mass spectrometry-based biochemical profiling.

    Science.gov (United States)

    Kaszynski, Richard H; Nishiumi, Shin; Azuma, Takeshi; Yoshida, Masaru; Kondo, Takeshi; Takahashi, Motonori; Asano, Migiwa; Ueno, Yasuhiro

    2016-05-01

    While the molecular mechanisms underlying postmortem change have been exhaustively investigated, the establishment of an objective and reliable means for estimating postmortem interval (PMI) remains an elusive feat. In the present study, we exploit low molecular weight metabolites to estimate postmortem interval in mice. After sacrifice, serum and muscle samples were procured from C57BL/6J mice (n = 52) at seven predetermined postmortem intervals (0, 1, 3, 6, 12, 24, and 48 h). After extraction and isolation, low molecular weight metabolites were measured via gas chromatography/mass spectrometry (GC/MS) and examined via semi-quantification studies. Then, PMI prediction models were generated for each of the 175 and 163 metabolites identified in muscle and serum, respectively, using a non-linear least squares curve fitting program. A PMI estimation panel for muscle and serum was then erected which consisted of 17 (9.7%) and 14 (8.5%) of the best PMI biomarkers identified in muscle and serum profiles demonstrating statistically significant correlations between metabolite quantity and PMI. Using a single-blinded assessment, we carried out validation studies on the PMI estimation panels. Mean ± standard deviation for accuracy of muscle and serum PMI prediction panels was -0.27 ± 2.88 and -0.89 ± 2.31 h, respectively. Ultimately, these studies elucidate the utility of metabolomic profiling in PMI estimation and pave the path toward biochemical profiling studies involving human samples.

  14. Mass transfer coefficient in disturbed flow due to orifice for flow accelerated corrosion in nuclear power plant

    International Nuclear Information System (INIS)

    Prasad, Mahendra; Gaikwad, Avinash J.; Sridharan, Arunkumar; Parida, Smrutiranjan

    2015-01-01

    The flow of fluid in pipes cause corrosion wherein the inner surface of pipe becomes progressively thinner and susceptible to failure. This form of corrosion dependent on flow dynamics is called Flow Accelerated Corrosion (FAC) and has been observed in Nuclear Power Plants (NPPs). Mass transfer coefficient (MTC) is related to extent of wall thinning and it changes from its value in a straight pipe (with same fluid parameters) for flow in orifices, bends, junctions etc. due to gross disturbance of the velocity profile. This paper presents two-dimensional computational fluid dynamics (CFD) simulations for an orifice configuration in a straight pipe. Turbulent model K- ω with shear stress transport and transition flow was the model used for simulation studies. The mass transfer boundary layer (MTBL) thickness δ mtbl is related to the Schmidt number (Sc) and hydrodynamic boundary layer thickness δ h , as δ mtbl ~ δh/(Sc 1/3 ). MTBL is significantly smaller than δ h and hence boundary layer meshing was carried out deep into δ mtbl . Uniform velocity profile was applied at the inlet. Post orifice fluid shows large recirculating flows on the upper and lower wall. At various locations after orifice, mass transfer coefficient is calculated and compared with the value in straight pipe with fully developed turbulent flow. The MTC due to the orifice increases and it is correlated with enhanced FAC in region after orifice. (author)

  15. Measurements of δ11B in water by use of a mass spectrometer with accelerator

    Science.gov (United States)

    Di Fusco, Egidio; Rubino, Mauro; Marzaioli, Fabio; Di Rienzo, Brunella; Stellato, Luisa; Ricci, Andreina; Porzio, Giuseppe; D'onofrio, Antonio; Terrasi, Filippo

    2017-12-01

    This study describes the tests carried out to measure the isotopic composition of Boron (B) in water samples by use of the magnetic spectrometer and accelerator of the Center for Isotopic Research on Cultural and Environmental heritage (CIRCE) of Italy. B was extracted from water samples to obtain Boric acid (B(OH)3), which was then analyzed. We quantified the precision of our experimental system and the variability introduced by the chemical extraction measuring chemically untreated and treated pure B(OH)3 samples. We found an instrumental precision around 10‰ (1σ), but, by increasing the number of replicates (>30), we obtained a standard deviation of the mean (σerr) around 3‰ or lower. We also tested whether the chemical extraction caused isotopic fractionation and found a small fractionation (ε = 5 ± 4‰) of treated samples normalized against untreated ones, compatible with zero at 2σ. In order to avoid δ11B biases, we decided to normalize unknown treated samples with treated standards. Finally, we measured δ11B of seawater and groundwater samples to test the analytical method, and obtained values of 30 ± 6‰ and -4 ± 4‰ respectively. We conclude that our experimental system is only suitable when remarkable (>10‰) δ11B differences exist among water samples, but cannot be used to measure natural differences (<10‰) unless the total uncertainty is significantly decreased.

  16. Laparoscopic Removal of a Large Ovarian Mass Utilizing Planned Trocar Puncture

    OpenAIRE

    Stitely, Michael L.

    2012-01-01

    Background: Large cystic ovarian masses pose technical challenges to the laparoscopic surgeon. Removing large, potentially malignant specimens must be done with care to avoid the leakage of cyst fluid into the abdominal cavity. Case: We present the case of a large ovarian cystic mass treated laparoscopically with intentional trocar puncture of the mass to drain and remove the mass. Discussion: Large cystic ovarian masses can be removed laparoscopically with intentional trocar puncture of the ...

  17. Does reproduction accelerate the growth of eye lens mass in female voles?

    Czech Academy of Sciences Publication Activity Database

    Jánová, Eva; Havelková, Dana; Tkadlec, Emil

    2007-01-01

    Roč. 137, č. 1 (2007), s. 85-88 ISSN 0777-6276 R&D Projects: GA ČR GA206/04/2003; GA ČR(CZ) GD524/05/H536 Institutional research plan: CEZ:AV0Z60930519 Keywords : age estimation * eye lens mass * reproduction Subject RIV: EH - Ecology, Behaviour Impact factor: 0.433, year: 2007 http://www.naturalsciences.be/institute/associations/rbzs_website/bjz/back/pdf/BJZ%20137(1)/Volume%20137(1),%20pp.%2085-88.pdf

  18. XCAMS: The compact 14C accelerator mass spectrometer extended for 10Be and 26Al at GNS Science, New Zealand

    Science.gov (United States)

    Zondervan, A.; Hauser, T. M.; Kaiser, J.; Kitchen, R. L.; Turnbull, J. C.; West, J. G.

    2015-10-01

    A detailed description is given of the 0.5 MV tandem accelerator mass spectrometry (AMS) system for 10Be, 14C, 26Al, installed in early 2010 at GNS Science, New Zealand. Its design follows that of previously commissioned Compact 14C-only AMS (CAMS) systems based on the Pelletron tandem accelerator. The only basic departure from that design is an extension of the rare-isotope achromat with a 45° magnet and a two-anode gas-ionisation detector, to provide additional filtering for 10Be. Realised performance of the three AMS modes is discussed in terms of acceptance-test scores, 14C Poisson and non-Poisson errors, and 10Be detection limit and sensitivity. Operational details and hardware improvements, such as 10Be beam transport and particle detector setup, are highlighted. Statistics of repeat measurements of all graphitised 14C calibration cathodes since start-up show that 91% of their total uncertainty values are less than 0.3%, indicating that the rare-isotope beamline extension has not affected precision of 14C measurement. For 10Be, the limit of detection in terms of the isotopic abundance ratio 10Be/9Be is 6 × 10-15 at at-1 and the total efficiency of counting atoms in the sample cathode is 1/8500 (0.012%).

  19. Development of an extraction method for the determination of dissolved organic radiocarbon in seawater by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Tanaka, Takayuki; Otosaka, Shigeyoshi; Togawa, Orihiko; Amano, Hikaru

    2009-01-01

    We developed an extraction method for accurately and reproducibly determining dissolved organic radiocarbon in seawater by ultraviolet oxidation of dissolved organic carbon and subsequent accelerator mass spectrometry. We determined the irradiation time required for oxidation of the dissolved organic carbon. By modifying the experimental apparatus, we decreased contamination by dead carbon, which came mainly from petrochemical products in the apparatus and from the incursion of carbon dioxide from the atmosphere. The modifications decreased the analytical blank level to less than 1% of sample size, a percentage that had not previously been achieved. The recovery efficiency was high, 95±1%. To confirm both the accuracy and reproducibility of the method, we tested it by analyzing an oxalic acid radiocarbon reference material and by determining the dissolved organic carbon in surface seawater samples. (author)

  20. First accelerator mass spectrometry {sup 14}C dates documenting contemporaneity of nonanalog species in late Pleistocene mammal communities

    Energy Technology Data Exchange (ETDEWEB)

    Stafford, T.W. Jr.; Semken, H.A. Jr.; Graham, R.W.; Klippel, W.F.; Markova, A.; Smirnov, N.G.; Southon, J.

    1999-10-01

    Worldwide late Pleistocene terrestrial mammal faunas are characterized by stratigraphic associations of species that now have exclusive geographic ranges. These have been interpreted as either taphonomically mixed or representative of communities that no longer exist. Accelerator mass spectrometry {sup 14}C dates (n = 60) on single bones of stratigraphically associated fossil micromammals from two American and two Russian sites document for the first time that currently allopatric mammals occurred together between 12,000 and 22,000 yr B.P. on two continents. The existence of mammal communities without modern analogs demonstrates that Northern Hemisphere biological communities are ephemeral and that many modern biomes are younger than 12 ka. Future climate change may result in new nonanalog communities.

  1. Ultra-trace determination of neptunium-237 and plutonium isotopes in urine samples by compact accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Dai, X.; Christl, M.; Kramer-Tremblay, S., E-mail: sheila.kramer-tremblay@cnl.ca [Canadian Nuclear Laboratories, Chalk River, Ontario (Canada); Synal, H-A. [ETH Zurich, Lab. of Ion Beam Physics, Zurich (Switzerland)

    2015-12-15

    Ultra-trace analysis of actinides, such as Pu isotopes and {sup 237}Np, in bioassay samples is often needed for radiation protection programs at nuclear facilities. Accelerator mass spectrometry (AMS), particularly the compact ETH Zurich system “Tandy”, has evolved over the years as one of the most sensitive, selective, and robust techniques for actinide analysis. Employment of the AMS technique can reduce the demands on sample preparation chemistry and increase sample analysis throughput, due to very low instrumental detection limit, high rejection of interferences, and low susceptibility to adverse sample matrices. Initial research and development tests were performed to explore and demonstrate the analytical capability of AMS for Pu and Np urine bioassay. In this study, urine samples spiked with femtogram levels of Np and Pu isotopes were prepared and measured using compact ETH AMS system and the results showed excellent analytical capability for measuring Np and Pu isotopes at femtogram/litre levels in urine. (author)

  2. Possibility of content change in bioethanol gasoline during pre-treatment process for using accelerator mass spectroscopy

    International Nuclear Information System (INIS)

    Saito, Masaaki; Yunoki, Shunji; Suzuki, Takashi

    2010-01-01

    We attempted to determine the bioethanol content of E3 gasoline by applying ASTM D6866 method B. In the pre-treatment process using accelerator mass spectroscopy(AMS), the graphite samples were prepared from E3 gasoline. Three portions of the same graphite sample were measured, and the contents agreed within the measurement error of AMS. The graphite samples prepared from eight portions of the same E3 gasoline sample were measured, but the accuracy was insufficient. There are many kinds of hydrocarbon compounds in the gasoline and their boiling points are different. The content of bioethanol was found to decrease with vaporization when E3 gasoline was placed in open air. A very small amount of E3 gasoline is pre-treated for AMS and the volatile loss cannot be ignored. It seems that the content change of bioethanol was caused by vaporization of E3 gasoline during the pre-treatment process. (author)

  3. Determination of long-lived radionuclide (10Be, 41Ca, 129I) concentrations in nuclear waste by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Nottoli, Emmanuelle; Bienvenu, Philippe; Labet, Alexandre; Bertaux, Maite; Bourles, Didier; Arnold, Maurice

    2013-01-01

    Radiological characterization of nuclear waste is essential for storage sites management. However, most of Long-Lived Radionuclides (LLRN), important for long-term management, are difficult to measure since concentration levels are very low and waste matrices generally complex. In an industrial approach, LLRN concentrations are not directly measured in waste samples but assessed from scaling factors with respect to easily measured gamma emitters. Ideally, the key nuclide chosen ( 60 Co, 137 Cs) should be produced by a similar mechanism (fission or activation) as the LLRN of interest and should have similar physicochemical properties. However, the uncertainty on the scaling factors, determined from experimental and/or calculation data, can be quite important. Consequently, studies are performed to develop analytical procedures which would lead to determine precisely the concentration of LLRN in nuclear waste. In this context, the aim of this study was to determine the concentrations of three LLRN: 129 I (T 1/2 = 15.7*10 6 a), 41 Ca (T 1/2 = 9.94*10 4 a) and 10 Be (T 1/2 = 1.387*10 6 a) in spent resins used for primary fluid purification in Pressurized Water Reactors using Accelerator Mass Spectrometry (AMS) for measurement. The AMS technique combined mass spectrometry and nuclear physics to achieve highly efficient molecular and elemental isobars separation. Energies of several Million Electron-Volt transferred to the ions in the first accelerating part of specifically developed tandem accelerators lead to molecular isobars destruction through interaction with the argon gas used to strip the injected negative ions to positive ones. At the exit of the tandem accelerator, the energy acquired in both accelerating parts allows an elemental isobars separation based on their significantly different energy loss (dE) while passing through a thickness of matter dx that is proportional to their atomic number (Z) and inversely proportional to ions velocity (v) according to the

  4. Metabolic profiling of yeast culture using gas chromatography coupled with orthogonal acceleration accurate mass time-of-flight mass spectrometry: application to biomarker discovery.

    Science.gov (United States)

    Kondo, Elsuida; Marriott, Philip J; Parker, Rhiannon M; Kouremenos, Konstantinos A; Morrison, Paul; Adams, Mike

    2014-01-07

    Yeast and yeast cultures are frequently used as additives in diets of dairy cows. Beneficial effects from the inclusion of yeast culture in diets for dairy mammals have been reported, and the aim of this study was to develop a comprehensive analytical method for the accurate mass identification of the 'global' metabolites in order to differentiate a variety of yeasts at varying growth stages (Diamond V XP, Yea-Sacc and Levucell). Microwave-assisted derivatization for metabolic profiling is demonstrated through the analysis of differing yeast samples developed for cattle feed, which include a wide range of metabolites of interest covering a large range of compound classes. Accurate identification of the components was undertaken using GC-oa-ToFMS (gas chromatography-orthogonal acceleration-time-of-flight mass spectrometry), followed by principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) for data reduction and biomarker discovery. Semi-quantification (fold changes in relative peak areas) was reported for metabolites identified as possible discriminative biomarkers (p-value 2), including D-ribose (four fold decrease), myo-inositol (five fold increase), L-phenylalanine (three fold increase), glucopyranoside (two fold increase), fructose (three fold increase) and threitol (three fold increase) respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Mass-spectrometer for on-line operation with an accelerator

    International Nuclear Information System (INIS)

    Belyaev, B.N.; Gall', L.N.; Domkin, V.D.

    1974-01-01

    The paper describes the most essential elements and parameters of a mass-spectrometer designed for the on-line operation with the Leningrad Institute for Nuclear Physics synchrocyclotron with an extracted 1 GeV proton beam. The mass-spectrometer consists of two sections: analytical and measuring. A thermal ionization ion source is used for measuring isotope composition of nuclear reaction alkaline products produced in a target under the effect of 19 ev protons. While the selection and development of an ion-optical system for the source a provision had to be made for a high efficiency of the device as well as a stobility of parameters of the ion-optical system. To meet these requirements a massive electrode principle formed the basis of the system. Electrodes were a slit-type system consisted of three cylindrical lenses. Anion-optical system scheme is given in the paper. The employment of the ion-optical system with a small angle divergence in the horizontal plane provided for a high resolution of the spectrometer, approximately 400 at the relative aperture of 14-16%. The target consisted of a stack of MPG-6 graphite plates (20-30 pcs), 0.1 mm thick, 9x18 mm; the plates were fixed (1x10 0.1 mm apart by means of narrow in terlayers (1x10 mm) of the same material. For ensuring optimal diffusion and ionization depending upon the chemical element under study the target was heated up to 1.500-1.900 deg C. Results were obtained on the production cross-sections of lithium (6, 7, 8, 9 Li) isotope in the carbon target. While measuring sup(7, 8, 9)Li isotope yields the target irradiation period was 15 min and for 6 Li 3 min. The background was measured for each line of a mass-spectrum with proton beam off. The results obtained for the lithium isotope production cross section are of interests for discussions on problems of the light element production in cosmic rays

  6. Accelerated bridge construction utilizing precast pier caps on state highway 69 over Turkey Creek, Huerfano County, CO.

    Science.gov (United States)

    2014-07-01

    The purpose of this report is to document Accelerated Bridge Construction (ABC) techniques on IBRD : (Innovative Bridge Research and Development) project 102470 for the construction of Bridge N-16-Q : on State Highway 69 over Turkey Creek. The constr...

  7. Laparoscopic Removal of a Large Ovarian Mass Utilizing Planned Trocar Puncture

    Science.gov (United States)

    2012-01-01

    Background: Large cystic ovarian masses pose technical challenges to the laparoscopic surgeon. Removing large, potentially malignant specimens must be done with care to avoid the leakage of cyst fluid into the abdominal cavity. Case: We present the case of a large ovarian cystic mass treated laparoscopically with intentional trocar puncture of the mass to drain and remove the mass. Discussion: Large cystic ovarian masses can be removed laparoscopically with intentional trocar puncture of the mass to facilitate removal without leakage of cyst fluid. PMID:22906344

  8. Mass acceleration in a multi-module plasma jet for impact fusion. Final report, 21 May 1984-21 May 1985

    International Nuclear Information System (INIS)

    Burton, R.L.; Goldstein, S.A.; Tidman, D.A.; Massey, D.W.; Winsor, N.K.; Witherspoon, F.D.

    1985-07-01

    GT-Devices began work on multi-module mass accelerators for impact fusion in 1981. The technique employs sequentially switched high pressure plasma jets to accelerate a lightweight projectile in a circular barrel. The purpose of the work of the past 12 months was to improve the understanding of the plasma jet acceleration process, and to translate that understanding into verifiable results. Both goals have been accomplished. During the past year we conceived, designed, built and fired 325 shots on the Module Test Facility (MTF). This facility provided sufficient diagnostics to investigate a wide variety of geometries, plasmas and current pulses, so that rapid progress was made

  9. Utilizing mass spectrometry imaging to map the thyroid hormones triiodothyronine and thyroxine in Xenopus tropicalis tadpoles.

    Science.gov (United States)

    Goto-Inoue, Naoko; Sato, Tomohiko; Morisasa, Mizuki; Kashiwagi, Akihiko; Kashiwagi, Keiko; Sugiura, Yuki; Sugiyama, Eiji; Suematsu, Makoto; Mori, Tsukasa

    2018-02-01

    Thyroid hormones are not only responsible for thermogenesis and energy metabolism in animals, but also have an important role in cell differentiation and development. Amphibian metamorphosis provides an excellent model for studying the remodeling of the body. This metamorphic organ remodeling is induced by thyroid hormones, and a larval body is thus converted into an adult one. The matrix-assisted laser desorption/ionization (MALDI)-mass spectrometry (MS) imaging technology is expected to be a suitable tool for investigating small bioreactive molecules. The present study describes the distribution of the thyroid hormones, i.e., triiodothyronine (T3) and thyroxine (T4) and their inactive form reverse T3 (rT3) in Xenopus tropicalis tadpoles using two different types of imaging techniques, MS/MS and Fourier transform (FT)-MS imaging. As a result of MS/MS imaging, we demonstrated that T3 was mainly distributed in the gills. T4 was faintly localized in the eyes, inner gills, and intestine during metamorphosis. The intensity of T3 in the gills and the intensity of T4 in the body fluids were increased during metamorphosis. Moreover, the localization of the inactive form rT3 was demonstrated to be separate from T3, namely in the intestine and muscles. In addition, FT-MS imaging could utilize simultaneous imaging including thyroid hormone. This is the first report to demonstrate the molecular distribution of thyroid hormones themselves and to discriminate T3, T4, and rT3 in animal tissues.

  10. Coevaporation of Y, BaF2, and Cu utilizing a quadrupole mass spectrometer as a rate measuring probe

    International Nuclear Information System (INIS)

    Hudner, J.; Oestling, M.; Ohlsen, H.; Stolt, L.

    1991-01-01

    An ultrahigh vacuum coevaporator equipped with three sources for preparation of Y--BaF 2 --Cu--O thin films is described. Evaporation rates of Y, BaF 2 , and Cu were controlled using a quadrupole mass spectrometer operating in a multiplexed mode. To evaluate the method depositions have been performed using different source configurations and evaporation rates. Utilizing Rutherford backscattering spectrometry absolute values of the actual evaporation rates were determined. It was observed that the mass-spectrometer sensitivity is highest for Y, followed by BaF 2 (BaF + is the measured ion) and Cu. A partial pressure of oxygen during evaporation of Y, BaF 2 , and Cu affected mainly the rate of Y. It is shown that the mass spectrometer can be utilized to precisely control the film composition

  11. Using Dark Matter Haloes to Learn about Cosmic Acceleration: A New Proposal for a Universal Mass Function

    Science.gov (United States)

    Prescod-Weinstein, Chanda; Afshordi, Niayesh

    2011-01-01

    Structure formation provides a strong test of any cosmic acceleration model because a successful dark energy model must not inhibit or overpredict the development of observed large-scale structures. Traditional approaches to studies of structure formation in the presence of dark energy or a modified gravity implement a modified Press-Schechter formalism, which relates the linear overdensities to the abundance of dark matter haloes at the same time. We critically examine the universality of the Press-Schechter formalism for different cosmologies, and show that the halo abundance is best correlated with spherical linear overdensity at 94% of collapse (or observation) time. We then extend this argument to ellipsoidal collapse (which decreases the fractional time of best correlation for small haloes), and show that our results agree with deviations from modified Press-Schechter formalism seen in simulated mass functions. This provides a novel universal prescription to measure linear density evolution, based on current and future observations of cluster (or dark matter) halo mass function. In particular, even observations of cluster abundance in a single epoch will constrain the entire history of linear growth of cosmological of perturbations.

  12. Measurement of Young’s modulus and volumetric mass density/thickness of ultrathin films utilizing resonant based mass sensors

    Czech Academy of Sciences Publication Activity Database

    Stachiv, Ivo; Vokoun, David; Jeng, Y.-R.

    2014-01-01

    Roč. 104, č. 8 (2014), "083102-1"-"083102-4" ISSN 0003-6951 R&D Projects: GA ČR GAP107/12/0800 Institutional support: RVO:68378271 Keywords : functional films * mass sensor * resonant frequency Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 3.302, year: 2014 http://scitation.aip.org/content/aip/journal/apl/104/8/10.1063/1.4866417

  13. Potential of gas chromatography-orthogonal acceleration time-of-flight mass spectrometry (GC-oaTOFMS) in flavor research.

    Science.gov (United States)

    Fay, Laurent B; Newton, Anthony; Simian, Hervé; Robert, Fabien; Douce, David; Hancock, Peter; Green, Martin; Blank, Imre

    2003-04-23

    Gas chromatography-orthogonal acceleration time-of-flight mass spectrometry (GC-oaTOFMS) is an emerging technique offering a straightforward access to a resolving power up to 7000. This paper deals with the use of GC-oaTOFMS to identify the flavor components of a complex seafood flavor extract and to quantify furanones formed in model Maillard reactions. A seafood extract was selected as a representative example for complex food flavors and was previously analyzed using GC-quadrupole MS, leaving several molecules unidentified. GC-oaTOFMS analysis was focused on these unknowns to evaluate its potential in flavor research, particularly for determining exact masses. N-Methyldithiodimethylamine, 6-methyl-5-hepten-2-one, and tetrahydro-2,4-dimethyl-4H-pyrrolo[2,1-d]-1,3,5-dithiazine were successfully identified on the basis of the precise mass determination of their molecular ions and their major fragments. A second set of experiments was performed to test the capabilities of the GC-oaTOFMS for quantification. Calibration curves were found to be linear over a dynamic range of 10(3) for the quantification of furanones. The quantitative data obtained using GC-oaTOFMS confirmed earlier results that the formation of 4-hydroxy-2,5-dimethyl-3(2H)-furanone was favored in the xylose/glycine model reaction and 2(or 5)-ethyl-4-hydroxy-5(or 2)-methyl-3(2H)-furanone in the xylose/alanine model reaction. It was concluded that GC-oaTOFMS may become a powerful analytical tool for the flavor chemist for both identification and quantification purposes, the latter in particular when combined with stable isotope dilution assay.

  14. The use of aluminum nitride to improve Aluminum-26 Accelerator Mass Spectrometry measurements and production of Radioactive Ion Beams

    Science.gov (United States)

    Janzen, Meghan S.; Galindo-Uribarri, Alfredo; Liu, Yuan; Mills, Gerald D.; Romero-Romero, Elisa; Stracener, Daniel W.

    2015-10-01

    We present results and discuss the use of aluminum nitride as a promising source material for Accelerator Mass Spectrometry (AMS) and Radioactive Ion Beams (RIBs) science applications of 26Al isotopes. The measurement of 26Al in geological samples by AMS is typically conducted on Al2O3 targets. However, Al2O3 is not an ideal source material because it does not form a prolific beam of Al- required for measuring low-levels of 26Al. Multiple samples of aluminum oxide (Al2O3), aluminum nitride (AlN), mixed Al2O3-AlN as well as aluminum fluoride (AlF3) were tested and compared using the ion source test facility and the stable ion beam (SIB) injector platform at the 25-MV tandem electrostatic accelerator at Oak Ridge National Laboratory. Negative ion currents of atomic and molecular aluminum were examined for each source material. It was found that pure AlN targets produced substantially higher beam currents than the other materials and that there was some dependence on the exposure of AlN to air. The applicability of using AlN as a source material for geological samples was explored by preparing quartz samples as Al2O3 and converting them to AlN using a carbothermal reduction technique, which involved reducing the Al2O3 with graphite powder at 1600 °C within a nitrogen atmosphere. The quartz material was successfully converted to AlN. Thus far, AlN proves to be a promising source material and could lead towards increasing the sensitivity of low-level 26Al AMS measurements. The potential of using AlN as a source material for nuclear physics is also very promising by placing 26AlN directly into a source to produce more intense radioactive beams of 26Al.

  15. Secular trends of body mass index in North Indian children with Type 1 diabetes do not support the Accelerator Hypothesis.

    Science.gov (United States)

    Dayal, Devi; Samprathi, Madhusudan; Jayaraman, Dhaarani; Kohat, Dilesh; Bhalla, Anil Kumar

    2016-03-01

    The accelerator hypothesis, which proposes a link between Type 1 diabetes (T1D) and Type 2 diabetes (T2D) through weight-related insulin resistance, remains untested in developing countries with increasing rates of childhood obesity and T1D, and different ethnicities. We aimed to test the accelerator hypothesis in the context of a significant increase in T1D at our centre. Medical records of children diagnosed with T1D between January 2005 and December 2014 were retrospectively reviewed. The body mass index (BMI) standard deviation scores (SDSs) were calculated using height and weight measurements recorded 1-2 months after diagnosis of T1D and compared with age-matched anthropometric data. The rate of change in BMI SDSs over time was calculated. Analysis of BMI data was undertaken for the three age categories: 10 and >10 years. The mean age at diagnosis of 467 children with T1D was 7·27 ± 0·32 years and showed no change over the study period. There was a yearly increase of 14·11% in patient numbers; this increase was similar in the three age categories (22·7%, 17·0%, 16·3%, respectively, P = 1·0). Comparison of patient numbers between the two time periods of 5 years each showed a marked increase during 2010-2014 (148 vs 319, % increase 115·5%). The mean BMI SDSs at diagnosis in the three age categories were similar (P = 1·0) and showed a yearly change of -0·36; the mean change in the three age categories was also similar (-0·35, -0·27, -0·46, respectively, P = 1·0). No correlation was found between age at diagnosis and BMI SDSs (correlation coefficient 0·010, P = 0·82). The mean BMI SDS in patients was significantly lower compared to controls (-0·54 vs -0·02, P = 0·001). There was no association between BMI SDS and age at diagnosis in children with new onset T1D. Further studies are needed to test whether the accelerator hypothesis is relevant in developing countries. © 2015 John Wiley & Sons Ltd.

  16. On the utility of vacancies and tensile strain-induced quality factor enhancement for mass sensing using graphene monolayers

    International Nuclear Information System (INIS)

    Kim, Sung Youb; Park, Harold S

    2010-01-01

    We have utilized classical molecular dynamics to investigate the mass sensing potential of graphene monolayers, using gold as the model adsorbed atom. In doing so, we report two key findings. First, we find that while perfect graphene monolayers are effective mass sensors at very low (T < 10 K) temperatures, their mass sensing capability is lost at higher temperatures due to diffusion of the adsorbed atom at elevated temperatures. We demonstrate that even if the quality (Q) factors are significantly elevated through the application of tensile mechanical strain, the mass sensing resolution is still lost at elevated temperatures, which demonstrates that high Q-factors alone are insufficient to ensure the mass sensing capability of graphene. Second, we find that while the introduction of single vacancies into the graphene monolayer prevents the diffusion of the adsorbed atom, the mass sensing resolution is still lost at higher temperatures, again due to Q-factor degradation. We finally demonstrate that if the Q-factors of the graphene monolayers with single vacancies are kept acceptably high through the application of tensile strain, then the high Q-factors, in conjunction with the single atom vacancies to stop the diffusion of the adsorbed atom, enable graphene to maintain its mass sensing capability across a range of technologically relevant operating temperatures.

  17. The transmission theory of electrostatic analyzer in six dimensional phase space and the concept design of a supersensitive mass spectrometer beam line for HI-13 tandem accelerator

    International Nuclear Information System (INIS)

    Guan Xialing; Cao Qingxi; Zhang Jie; Ye Jingping

    1986-01-01

    It follows from the motion equations of charged particle in curvilinear coordinates system that the transfer matrix of electrostatic analyzer was derived in six dimensional phase space. In accordance with these matrixes, the concept design of the supersensitive mass spectrometer beam line for HI-13 tandem accelerator was calculated

  18. {sup 14} C dating by using mass spectrometry with particle accelerator; Datacao por {sup 14} C utilizando espectrometria de massa com acelerador de particulas

    Energy Technology Data Exchange (ETDEWEB)

    Santos, G.M.; Gomes, P.R.S. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Fisica]. E-mail: paulogom@if.uff.br; Yokoyama, Y. [Australian National Univ., Canberra (Australia). Research School of Earth Science; Tada, M.L. di; Cresswell, R.G.; Fifield, L.K. [Australian National Univ., Canberra (Australia). Dept. of Nuclear Physics

    1999-03-01

    The different aspects concerning the {sup 14} C dating are described, including the cosmogenic origin of {sup 14} C, its production and absorption by matter, the procedures to be followed for the age determination and the associated errors, particularly by the Accelerator Mass Spectrometry (AMS) technique, and the different steps of the sample preparation process. (author)

  19. Miniature Gas Chromatograph Mass Spectrometer for In-Situ Resource Utilization, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In situ resource utilization (ISRU) is essential for several of NASA's future flagship missions. Currently envisioned ISRU plants include production of oxygen from...

  20. Utility of Higher Harmonics in Electrospray Ionization Fourier Transform Electrostatic Linear Ion Trap Mass Spectrometry.

    Science.gov (United States)

    Dziekonski, Eric T; Johnson, Joshua T; McLuckey, Scott A

    2017-04-18

    Mass resolution (M/ΔM fwhm) is observed to linearly increase with harmonic order in a Fourier transform electrostatic linear ion trap (ELIT) mass spectrometer. This behavior was predicted by Grosshans and Marshall for frequency-multiple detection in a Fourier transform ion cyclotron resonance mass spectrometer only for situations when the prominent mechanism for signal decay is ion ejection from the trap. As the analyzer pressure in our ELIT chamber is relatively high, such that collisional scattering and collision-induced dissociation are expected to underlie much of the ion loss, we sought to explore the relationship between harmonic order and mass resolution. Mass resolutions of 36 900 (fundamental), 75 850 (2nd harmonic), and 108 200 (3rd harmonic) were obtained for GdO + (avg. m/z 173.919) with a transient length of 300 ms. To demonstrate that the mass resolution was truly increasing with harmonic order, the unresolved isotopes at the fundamental distribution of cytochrome c +8 (m/z ∼ 1549) were nearly baseline, resolved at the third harmonic (mass resolution ≈ 23 000) with a transient length of only 200 ms. This experiment demonstrates that, when the ion density is sufficiently low, ions with frequency differences of less than 4 Hz remain uncoalesced. Higher harmonics can be used to increase the effective mass resolution for a fixed transient length and thereby may enable the resolution of closely spaced masses, determination of a protein ion's charge state, and study of the onset of peak coalescence when the resolution at the fundamental frequency is insufficient.

  1. Quality of Graphite Target for Biological/Biomedical/Environmental Applications of 14C-Accelerator Mass Spectrometry

    Science.gov (United States)

    2010-01-01

    Catalytic graphitization for 14C-accelerator mass spectrometry (14C-AMS) produced various forms of elemental carbon. Our high-throughput Zn reduction method (C/Fe = 1:5, 500 °C, 3 h) produced the AMS target of graphite-coated iron powder (GCIP), a mix of nongraphitic carbon and Fe3C. Crystallinity of the AMS targets of GCIP (nongraphitic carbon) was increased to turbostratic carbon by raising the C/Fe ratio from 1:5 to 1:1 and the graphitization temperature from 500 to 585 °C. The AMS target of GCIP containing turbostratic carbon had a large isotopic fractionation and a low AMS ion current. The AMS target of GCIP containing turbostratic carbon also yielded less accurate/precise 14C-AMS measurements because of the lower graphitization yield and lower thermal conductivity that were caused by the higher C/Fe ratio of 1:1. On the other hand, the AMS target of GCIP containing nongraphitic carbon had higher graphitization yield and better thermal conductivity over the AMS target of GCIP containing turbostratic carbon due to optimal surface area provided by the iron powder. Finally, graphitization yield and thermal conductivity were stronger determinants (over graphite crystallinity) for accurate/precise/high-throughput biological, biomedical, and environmental14C-AMS applications such as absorption, distribution, metabolism, elimination (ADME), and physiologically based pharmacokinetics (PBPK) of nutrients, drugs, phytochemicals, and environmental chemicals. PMID:20163100

  2. Geomagnetic reversals, polar ice and cosmic spherules: some recent measurements with a small dedicated accelerator mass-spectrometry facility

    International Nuclear Information System (INIS)

    Raisbeck, G.M.; Yiou, F.

    1987-01-01

    We have developed techniques for measuring the cosmogenic isotopes 10 Be (half-life 1.5 Ma) and 26 Al (716 ka) by using a small (ca. 2.2 MV) dedicated accelerator mass spectrometer facility. Three recent applications of such measurements are as follows. 1. 10 Be has been measured in marine-sediment cores at levels corresponding to three recent geomagnetic reversals. We observe an increase in 10 Be production at each of these times. The results give information on the form and length of the geomagnetic intensity changes during a reversal, and the level at which magnetic remanence is acquired in the sediments. 2. 10 Be has been measured over a 2083 m ice core, corresponding to the last climatic cycle, recovered from Vostok, Antarctica. The results suggest that the precipitation rate during the last Ice Age was about half of its present rate. There are also some indications of fairly rapid 10 Be production changes. 3. 10 Be and 26 Al have been measured in 'cosmic spherules' (small round objects, ca. 500 μm diameter) recovered in deep-sea sediments and in melt lakes on Greenland ice. The results confirm an extraterrestrial origin for such objects, as well as indicating that the parent bodies of most of them were irradiated in space as small (less than 1 cm) objects. These spherules thus very probably represent cometary debris. (author)

  3. Determination of 240Pu/239Pu isotope ratios in Kara Sea and Novaya Zemlya sediments using accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Oughton, D.H.; Skipperud, L.; Salbu, B.; Fifield, L.K.; Cresswell, R.C.; Day, J.P.

    1999-01-01

    Accelerator mass spectrometry (AMS) has been used to determine Pu activity concentrations and 240 Pu/ 239 Pu isotope ratios in sediments from the Kara Sea and radioactive waste dumping sites at Novaya Zemlya. Measured 239,240 Pu activities ranged from 0.06 - 9.8 Bq/kg dry weight, 240 Pu/ 239 Pu atom ratios ranged from 0.13 to 0.28, and 238 Pu/ 239,240 Pu activity ratios from 0.02 to 0.6. Perturbations from global fallout isotope ratios were evident at three sites: the Yenisey Estuary and Abrosimov Fjords where 240 Pu/ 239 Pu ratios were lower (0.13-0.14); and Stepovogo Fjord sediments where ratios were higher (up to 0.28) than fallout ratios. Based on procedural blanks, detection limits for AMS were below 1 fg Pu and the method showed good precision for isotope ratio measurements, minimal matrix, interference and memory effects. For high level samples, comparison between alpha spectrometry and AMS gave good agreement for measurement of 239,240 Pu activity concentrations. (author)

  4. Human Vitamin B12 Absorption and Metabolism are Measured by Accelerator Mass Spectrometry Using Specifically Labeled 14C-Cobalamin

    International Nuclear Information System (INIS)

    Carkeet, C; Dueker, S R; Lango, J; Buchholz, B A; Miller, J W; Green, R; Hammock, B D; Roth, J R; Anderson, P J

    2006-01-01

    There is need for an improved test of human ability to assimilate dietary vitamin B 12 . Assaying and understanding absorption and uptake of B 12 is important because defects can lead to hematological and neurological complications. Accelerator mass spectrometry (AMS) is uniquely suited for assessing absorption and kinetics of 14 C-labeled substances after oral ingestion because it is more sensitive than decay counting and can measure levels of carbon-14 ( 14 C) in microliter volumes of biological samples, with negligible exposure of subjects to radioactivity. The test we describe employs amounts of B 12 in the range of normal dietary intake. The B 12 used was quantitatively labeled with 14 C at one particular atom of the DMB moiety by exploiting idiosyncrasies of Salmonellametabolism. In order to grow aerobically on ethanolamine, S. entericamust be provided with either pre-formed B 12 or two of its precursors: cobinamide and dimethylbenzimidazole (DMB). When provided with 14 C-DMB specifically labeled in the C2 position, cells produced 14 C-B 12 of high specific activity (2.1 GBq/mmol, 58 mCi/mmol) and no detectable dilution of label from endogenous DMB synthesis. In a human kinetic study, a physiological dose (1.5 mg, 2.2 KBq/59 nCi) of purified 14 C-B 12 was administered and showed plasma appearance and clearance curves consistent with the predicted behavior of the pure vitamin. This method opens new avenues for study of B 12 assimilation

  5. Biomedical Accelerator Mass Spectrometry

    Data.gov (United States)

    Federal Laboratory Consortium — Industrial partner projects focus on big, complex challenges and opportunities like smart grid, weather forecasting for renewable energy sources, alternative energy...

  6. Expanding the linear dynamic range for quantitative liquid chromatography-high resolution mass spectrometry utilizing natural isotopologue signals

    International Nuclear Information System (INIS)

    Liu, Hanghui; Lam, Lily; Yan, Lin; Chi, Bert; Dasgupta, Purnendu K.

    2014-01-01

    Highlights: • Less abundant isotopologue ions were utilized to decrease detector saturation. • A 25–50 fold increase in the upper limit of dynamic range was demonstrated. • Linear dynamic range was expanded without compromising mass resolution. - Abstract: The linear dynamic range (LDR) for quantitative liquid chromatography–mass spectrometry can be extended until ionization saturation is reached by using a number of target isotopologue ions in addition to the normally used target ion that provides the highest sensitivity. Less abundant isotopologue ions extend the LDR: the lower ion abundance decreases the probability of ion detector saturation. Effectively the sensitivity decreases and the upper limit of the LDR increases. We show in this paper that the technique is particularly powerful with a high resolution time of flight mass spectrometer because the data for all ions are automatically acquired, and we demonstrated this for four small organic molecules; the upper limits of LDRs increased by 25–50 times

  7. Mass acceleration in a multi-module plasma jet for impact fusion. Final report, 31 July 1985-30 July 1986

    International Nuclear Information System (INIS)

    Burton, R.L.; Goldstein, S.A.; Tidman, D.A.; Wang, S.Y.; Winsor, N.K.; Witherspoon, F.D.

    1986-08-01

    Successful development of a mass accelerator for impact fusion requires successful development of its components. The Advanced Impluse Module (AIM) is now operational, and is presently being used to povide a structured armature for electromagnetic gun experiments. Metals materials have been identified for the accelerator bore, and their limits identified and tested. A side-mounted, removable projectile detector and its circuitry has been developed. The next step is to use these components to achieve significantly higher velocities than have been achieved by our previous technology

  8. Evaluation of mixing and mass transfer in a stirred pilot scale bioreactor utilizing CFD

    DEFF Research Database (Denmark)

    Bach, Christian; Yang, Jifeng; Larsson, Hilde Kristina

    2017-01-01

    Knowledge and prediction of mixing and mass transfer in agitated bioreactors is fundamental for process development and scale up. In particular key process parameters such as mixing time and volumetric mass transfer coefficient are essential for bioprocess development. In this work the mixing...... and mass transfer performance of a high power agitated pilot scale bioreactor has been characterized using a novel combination of computational fluid dynamics (CFD) and experimental investigations. The effect of turbulence inside the vessel was predicted using a standard RANS k-ε model. Mixing time...... transfer coefficients were in accordance with the experimental data. This work illustrates the possibility of predicting the two phase fluid dynamic performance of an agitated pilot scale bioreactor using validated CFD models. These models can be applied to illustrate the effect of changing the physical...

  9. Accelerator development

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    Because the use of accelerated heavy ions would provide many opportunities for new and important studies in nuclear physics and nuclear chemistry, as well as other disciplines, both the Chemistry and Physics Divisions are supporting the development of a heavy-ion accelerator. The design of greatest current interest includes a tandem accelerator with a terminal voltage of approximately 25 MV injecting into a linear accelerator with rf superconducting resonators. This combined accelerator facility would be capable of accelerating ions of masses ranging over the entire periodic table to an energy corresponding to approximately 10 MeV/nucleon. This approach, as compared to other concepts, has the advantages of lower construction costs, lower operating power, 100 percent duty factor, and high beam quality (good energy resolution, good timing resolution, small beam size, and small beam divergence). The included sections describe the concept of the proposed heavy-ion accelerator, and the development program aiming at: (1) investigation of the individual questions concerning the superconducting accelerating resonators; (2) construction and testing of prototype accelerator systems; and (3) search for economical solutions to engineering problems. (U.S.)

  10. A study on excavation of rock mass by lasers. Researching the possibility of utilizing low-power lasers

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Fumio [Taisei Corporation, Technology Research Center, Yokohama, Kanagawa (Japan)

    2000-03-01

    The object of this research is to develop the techniques of rock-mass excavation by laser irradiation. This rock-mass excavation technique by lasers has a characteristic of extremely little effect to the surroundings of an excavation site no matter how the target rock mass is with regard to geological aspects and given physical property. Moreover, it could be utilized in excavation of waste dump facilities, which need to be re-buried, and applied to excavation of long piles and tunnels, which are drilled through different kinds of strata, and to improvement of rock mass and ground. Lasers have a characteristic of concentrating the energy into a limited point and not only discontinue or cut a large area with a small output like sharp scissors but also block up the cracks deep inside the rock mass by fusing vitrification for its improvement. It leads to restrain the loss of energy, minimization of the effected environment, effective utilization of resources and energy, environmental restoration, and improvement of the working environment. In the field of nuclear fuel, which includes excavating dump pits, dismantling a furnace, and taking appropriate steps of mine remains, excavating, cutting, and fusing could be required to do within a limited space of rock mass or concrete. Up to the present, those things have been done mainly by large machines, but it is too scarce in possibility for them to improve their large size, heavy weight, difficulty in unmanned operation, limited shapes of cutting, and stabilization of waste. In this research the concrete system images have been examined, doing the fundamental researches about higher-power lasers, smaller sizing, transmitting by fibers to find our the breakthrough to realization of laser excavation, This year, as the summary of examining the laser excavation techniques, utilizing a low-power laser, which is thought to be highly effective in rock-mass improvement, will be examined, considering application of the technique

  11. Quantification of absorption, retention and elimination of two different oral doses of vitamin A in Zambian boys using accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Aklamati, E.K.; Mulenga, M.; Dueker, S.R.; Buchholz, B.A.; Peerson, J.M.; Kafwembe, E.; Brown, K.H.; Haskell, M.J.

    2009-01-01

    A recent survey indicated that high-dose vitamin A supplements (HD-VAS) had no apparent effect on vitamin A (VA) status of Zambian children 14 C 2 )-labeled VA was co-administered with the HD-VAS or SI-labeled VA, and 24-hr stool and urine samples were collected for 3 and 7 consecutive days, respectively, and 24-hr urine samples at 4 later time points. Accelerator Mass Spectrometry (AMS) was used to measure the cumulative excretion of 14 C in stool and urine 3d after dosing to estimate, respectively, absorption and retention of the VAS and SI-labeled VA. The urinary elimination rate (UER) was estimated by plotting 14 C in urine vs. time, and fitting an exponential equation to the data. Estimates of mean absorption, retention and the UER were 83.8 ± 7.1%, 76.3 ± 6.7%, and 1.9 ± 0.6%/d, respectively, for the HD-VAS and 76.5 ± 9.5%, 71.1 ± 9.4%, and 1.8 ± 1.2%/d, respectively for the smaller dose of SI-labeled VA. Estimates of absorption, retention and the UER did not differ by size of the VA dose administered (P=0.26, 0.40, 0.88, respectively). Estimated absorption and retention were negatively associated with reported fever (P=0.011) and malaria (P =0.010). HD-VAS and SI-labeled VA were adequately absorbed, retained and utilized in apparently healthy Zambian preschool-age boys, although absorption and retention may be affected by recent infections.

  12. Risk-benefit analysis for mass screening of breast cancer utilizing mammography as a screening test

    International Nuclear Information System (INIS)

    Iinuma, T.A.; Tateno, Yukio

    1989-01-01

    Incidence of breast cancers in Japanese women is increasing steadily. Mass screening of breast cancer was started in Japan under auspices of Adult Health Promotion Act of the Japanese Government from 1987. As the first screening method, the palpation of breasts is employed at present, but it is expected to be replaced by the mammography. In this report, the risk-benefit analysis is presented between risk of breast carcinogenesis due to radiation and benefit of mass screening of breast cancer. The benefit of mass screening is taken as the net elongation of average life expectancy of women due to survival from breast cancers. The risk of mammography is taken as the net loss of average life expectancy of women due to breast carcinogenesis. In the latter, the latency time and plateau period of radiation carcinogenesis were taken into consideration in the calculation. The results show that the ages at which the benefit and risk become equal are between 30 and 35 years old when dose equivalent of mammography is between 10 and 20 mSv, that are conventionally used. However, the critical age will be reduced to 20 years old if the dose equivalent becomes 1 mSv. Therefore, it is strongly recommended that a low dose mammographic system should be developed in order to achieve 1 mSv for the mass screening of breast cancer of Japanese women. In author's opinion, this is quite feasible by employing a new digital radiography with imaging plate. (author)

  13. Tracing discharges of plutonium and technetium from nuclear processing plants by ultra-sensitive accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Fifield, L.K.; Hausladen, P.A.; Cresswell, R.G.; Di Tada, M.L.; Day, J.P.; Carling, R.S.; Oughton, D.H.

    1999-01-01

    Historical discharges of plutonium from the Russian nuclear processing plant at Mayak in the Urals have been traced in sediments, soils and river water using ultra-sensitive detection of plutonium isotopes by accelerator mass spectrometry (AMS). Significant advantages of AMS over other techniques are its very high sensitivity. which is presently ∼10 6 atoms (1 μBq), and its ability to determine the 240 Pu/ 239 Pu ratio. The latter is a sensitive indicator of the source of the plutonium, being very low (1-2%) for weapons grade plutonium, and higher (∼ 20%) for plutonium from civil reactors or fallout from nuclear weapons testing. Since this ratio has changed significantly over the years of discharges from Mayak, a measurement can provide important information about the source of plutonium at a particular location. Similar measurements have been performed on samples from the Kara Sea which contains a graveyard of nuclear submarines from the former Soviet Union. AMS techniques have also been developed for detection of 99 Tc down to levels of a few femtograms. This isotope is one of the most prolific fission products and has a very long half-life of 220 ka. Hundreds of kg have been discharged from the nuclear reprocessing plant at Sellafield in the UK. While there may be public health issues associated with these discharges which can be addressed with AMS, these discharges may also constitute a valuable oceanographic tracer experiment in this climatically-important region of the world's oceans. Applications to date have included a human uptake study to assess long-term retention of 99 Tc in the body, and a survey of seaweeds from northern Europe to establish a baseline for a future oceanographic study

  14. Long-lived radionuclides as chronometers and tracers of environmental processes at the Xi'an Accelerator Mass Spectrometry center

    Science.gov (United States)

    Zhou, W.; Hou, X.; Du, Y.; Kong, X.; Cheng, P.; Zhang, L.; Fan, Y.; Zhang, L.; Niu, Z.; Dong, G.; Chen, N.; Li, M.; Zhu, Y.

    2017-12-01

    Long-lived radionuclides with half-lives ranging from 103 to 108 years have wide applications in geochronology and environmental tracer studies. A wide range of climatic, geologic, and environmental records preserved in diverse natural archives can be characterized by measuring their concentrations, using accelerator mass spectrometry (AMS). Relying on the operation of the Xi'an 3 MV multi-element AMS since 2006, multi-radionuclides such as 14C, 10Be, 26Al, and 129I have been widely used for the above studies. Here some representative works on the four radionuclides can be briefly summarized as (1) we have successfully obtained temporal and spatial distribution of fossil fuel CO2 in certain cities in China by analyzing Δ14C from atmospheric CO2 and one year growth plants respectively, providing direct scientific data for government's emission cutting policy; (2) we have mathematically disentangled geomagnetic field and precipitation signals in Chinese loess 10Be, and firstly confirmed that the timing of Brunhes-Matuyama (B/M) reversal in loess was synchronous with that of marine sediments; (3) we have explored the paired in situ 10Be and 26Al double dating methodology for exposure dating, which has been successfully applied in fluvial terraces investigations in Tibet and glacial evolution tracing in East Antarctica; and (4) we have evaluated the radiation risk after Fukushima nuclear accident based on the 129I observation. All the above mentioned progress has opened up the new directions in AMS applications and we hope to show more new results in the near future.

  15. Kinetics of carboplatin-DNA binding in genomic DNA and bladder cancer cells as determined by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Hah, S S; Stivers, K M; Vere White, R; Henderson, P T

    2005-01-01

    Cisplatin and carboplatin are platinum-based drugs that are widely used in cancer chemotherapy. The cytotoxicity of these drugs is mediated by platinum-DNA monoadducts and intra- and interstrand diadducts, which are formed following uptake of the drug into the nucleus of cells. The pharmacodynamics of carboplatin display fewer side effects than for cisplatin, albeit with less potency, which may be due to differences in rates of DNA adduct formation. We report the use of accelerator mass spectrometry (AMS), a sensitive detection method often used for radiocarbon quantitation, to measure both the kinetics of [ 14 C]carboplatin-DNA adduct formation with genomic DNA and drug uptake and DNA binding in T24 human bladder cancer cells. Only carboplatin-DNA monoadducts contain radiocarbon in the platinated DNA, which allowed for calculation of kinetic rates and concentrations within the system. The percent of radiocarbon bound to salmon sperm DNA in the form of monoadducts was measured by AMS over 24 h. Knowledge of both the starting concentration of the parent carboplatin and the concentration of radiocarbon in the DNA at a variety of time points allowed calculation of the rates of Pt-DNA monoadduct formation and conversion to toxic cross-links. Importantly, the rate of carboplatin-DNA monoadduct formation was approximately 100-fold slower than that reported for the more potent cisplatin analogue, which may explain the lower toxicity of carboplatin. T24 human bladder cancer cells were incubated with a subpharmacological dose of [ 14 C]carboplatin, and the rate of accumulation of radiocarbon in the cells and nuclear DNA was measured by AMS. The lowest concentration of radiocarbon measured was approximately 1 amol/10 (micro)g of DNA. This sensitivity may allow the method to be used for clinical applications

  16. Kinetics of carboplatin-DNA binding in genomic DNA and bladder cancer cells as determined by accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Hah, S S; Stivers, K M; Vere White, R; Henderson, P T

    2005-12-29

    Cisplatin and carboplatin are platinum-based drugs that are widely used in cancer chemotherapy. The cytotoxicity of these drugs is mediated by platinum-DNA monoadducts and intra- and interstrand diadducts, which are formed following uptake of the drug into the nucleus of cells. The pharmacodynamics of carboplatin display fewer side effects than for cisplatin, albeit with less potency, which may be due to differences in rates of DNA adduct formation. We report the use of accelerator mass spectrometry (AMS), a sensitive detection method often used for radiocarbon quantitation, to measure both the kinetics of [{sup 14}C]carboplatin-DNA adduct formation with genomic DNA and drug uptake and DNA binding in T24 human bladder cancer cells. Only carboplatin-DNA monoadducts contain radiocarbon in the platinated DNA, which allowed for calculation of kinetic rates and concentrations within the system. The percent of radiocarbon bound to salmon sperm DNA in the form of monoadducts was measured by AMS over 24 h. Knowledge of both the starting concentration of the parent carboplatin and the concentration of radiocarbon in the DNA at a variety of time points allowed calculation of the rates of Pt-DNA monoadduct formation and conversion to toxic cross-links. Importantly, the rate of carboplatin-DNA monoadduct formation was approximately 100-fold slower than that reported for the more potent cisplatin analogue, which may explain the lower toxicity of carboplatin. T24 human bladder cancer cells were incubated with a subpharmacological dose of [{sup 14}C]carboplatin, and the rate of accumulation of radiocarbon in the cells and nuclear DNA was measured by AMS. The lowest concentration of radiocarbon measured was approximately 1 amol/10 {micro}g of DNA. This sensitivity may allow the method to be used for clinical applications.

  17. Pediatric microdose study of [(14)C]paracetamol to study drug metabolism using accelerated mass spectrometry: proof of concept.

    Science.gov (United States)

    Mooij, Miriam G; van Duijn, Esther; Knibbe, Catherijne A J; Windhorst, Albert D; Hendrikse, N Harry; Vaes, Wouter H J; Spaans, Edwin; Fabriek, Babs O; Sandman, Hugo; Grossouw, Dimitri; Hanff, Lidwien M; Janssen, Paul J J M; Koch, Birgit C P; Tibboel, Dick; de Wildt, Saskia N

    2014-11-01

    Pediatric drug development is hampered by practical, ethical, and scientific challenges. Microdosing is a promising new method to obtain pharmacokinetic data in children with minimal burden and minimal risk. The use of a labeled oral microdose offers the added benefit to study intestinal and hepatic drug disposition in children already receiving an intravenous therapeutic drug dose for clinical reasons. The objective of this study was to present pilot data of an oral [(14)C]paracetamol [acetaminophen (AAP)] microdosing study as proof of concept to study developmental pharmacokinetics in children. In an open-label microdose pharmacokinetic pilot study, infants (0-6 years of age) received a single oral [(14)C]AAP microdose (3.3 ng/kg, 60 Bq/kg) in addition to intravenous therapeutic doses of AAP (15 mg/kg intravenous every 6 h). Blood samples were taken from an indwelling catheter. AAP blood concentrations were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and [(14)C]AAP and metabolites ([(14)C]AAP-Glu and [(14)C]AAP-4Sul) were measured by accelerator mass spectrometry. Ten infants (aged 0.1-83.1 months) were included; one was excluded as he vomited shortly after administration. In nine patients, [(14)C]AAP and metabolites in blood samples were detectable at expected concentrations: median (range) maximum concentration (C max) [(14)C]AAP 1.68 (0.75-4.76) ng/L, [(14)C]AAP-Glu 0.88 (0.34-1.55) ng/L, and [(14)C]AAP-4Sul 0.81 (0.29-2.10) ng/L. Dose-normalized oral [(14)C]AAP C max approached median intravenous average concentrations (C av): 8.41 mg/L (3.75-23.78 mg/L) and 8.87 mg/L (3.45-12.9 mg/L), respectively. We demonstrate the feasibility of using a [(14)C]labeled microdose to study AAP pharmacokinetics, including metabolite disposition, in young children.

  18. Methods of direct (non-chromatographic) quantification of body metabolites utilizing chemical ionization mass spectrometry

    International Nuclear Information System (INIS)

    Mee, J.M.L.

    1978-01-01

    For quantitative determination of known metabolites from the biological sample by direct chemical ionization mass spectrometry (CI-MS), the method of internal standard using stable isotopically labelled analogs appears to be the method of choice. In the case where stable isotope ratio determinations could not be applied, and alternative quantification can be achieved using non-labelled external or internal standards and a calibration curve (sum of peak height per a given number of scans versus concentration). The technique of computer monitoring permits display and plotting of ion current profiles (TIC and SIC) or spectra per a given number of scans or a given range of mass per charge. Examples are given in areas of clinical application and the quantitative data show very good agreement with the conventional chromatographic measurements. (Auth.)

  19. Determination of total uranium by mass spectrometry utilizing the isotopic dilution technique

    International Nuclear Information System (INIS)

    Cretella, R.F.; Noutary, C.J.; Servant, R.E.

    1981-01-01

    The isotopic dilution associated to mass spectrometry is a high-sensitivity technique that allows to work with microquantities of the sample, making it possible to analize the content in highly radioactive solutions with excellent accuracy and minimum risk. The proposed technique is described and its results are discussed through the analysis of: 1) A synthetic sample that simulates dissolved spent fuel elements; 2) Uranium dioxide of nuclear purity and 3) Uranium concentrate. 233 U(ORNL) was employed as a tracer and a Nuclide 12-90-SU mass spectrometer of simple magnetic focus as measurement instrument. The accuracy reached in the analyses is better than 0.5% with a reliability of 95%. The analysis of the errors shows that their main contributing source are the errors in the measurement of the isotopic ratios. (M.E.L.) [es

  20. MRI imaging of fetal neck masses with airway compromise: utility in delivery planning

    Energy Technology Data Exchange (ETDEWEB)

    Kathary, N.; Bulas, D.I. [Dept. of Radiology, Children' s National Medical Center, Washington, DC (United States); Newman, K.D. [Dept. of Surgery, Children' s National Medical Center, Washington, DC (United States); Schonberg, R.L. [Dept. of Medical Genetics, Children' s National Medical Center, Washington, DC (United States)

    2001-10-01

    We present two cases of fetal neck masses that were initially diagnosed by ultrasound and further evaluated with prenatal MRI. MRI findings aided in further delineating the neck masses, increasing confidence in the final diagnosis (cervical teratoma and cystic hygroma). With the fetal airway typically filled with fluid that is of high signal on T2-weighted sequences, MRI images in three planes could identify whether the fetal larynx and trachea were partially or completely compressed by the neck tumor. This information was particularly useful in determining if a controlled delivery such as ex utero intrapartum treatment (EXIT) was necessary and aided the surgeons in planning their approach to establishing airway control in the delivery room. (orig.)

  1. MRI imaging of fetal neck masses with airway compromise: utility in delivery planning

    International Nuclear Information System (INIS)

    Kathary, N.; Bulas, D.I.; Newman, K.D.; Schonberg, R.L.

    2001-01-01

    We present two cases of fetal neck masses that were initially diagnosed by ultrasound and further evaluated with prenatal MRI. MRI findings aided in further delineating the neck masses, increasing confidence in the final diagnosis (cervical teratoma and cystic hygroma). With the fetal airway typically filled with fluid that is of high signal on T2-weighted sequences, MRI images in three planes could identify whether the fetal larynx and trachea were partially or completely compressed by the neck tumor. This information was particularly useful in determining if a controlled delivery such as ex utero intrapartum treatment (EXIT) was necessary and aided the surgeons in planning their approach to establishing airway control in the delivery room. (orig.)

  2. Increasing Student’s Character Values by Utilizing Combination of Team Accelerated Instruction (TAI and Numbered Heads Together (NHT

    Directory of Open Access Journals (Sweden)

    Ita Nuryana

    2016-06-01

    Full Text Available This research aims to obtain empirical evidence of the effectiveness of combining Team Accelerated Instruction (TAI and Numbered Heads Together (NHT learning strategies in teaching Investments to improve students’ discipline, creativity, diligence, and participation. Population was students who enrolled in Intermediate Financial Accounting 2 course in Economics Education Department; Economics Faculty of Universitas Negeri Semarang The sample of the research consists of 48 students. Data were collected by using observations, interviews, and documentation. The stages of the research include planning, implementation, monitoring and evaluation, analysis, and reflection. Findings show that the combination of TAI and NHT does not improve students’ learning outcomes even thought it manages to increase students’ pre-test score in learning Investments as well as their participation in classroom.

  3. Solid-state Marx based two-switch voltage modulator for the On-Line Isotope Mass Separator accelerator at the European Organization for Nuclear Research.

    Science.gov (United States)

    Redondo, L M; Silva, J Fernando; Canacsinh, H; Ferrão, N; Mendes, C; Soares, R; Schipper, J; Fowler, A

    2010-07-01

    A new circuit topology is proposed to replace the actual pulse transformer and thyratron based resonant modulator that supplies the 60 kV target potential for the ion acceleration of the On-Line Isotope Mass Separator accelerator, the stability of which is critical for the mass resolution downstream separator, at the European Organization for Nuclear Research. The improved modulator uses two solid-state switches working together, each one based on the Marx generator concept, operating as series and parallel switches, reducing the stress on the series stacked semiconductors, and also as auxiliary pulse generator in order to fulfill the target requirements. Preliminary results of a 10 kV prototype, using 1200 V insulated gate bipolar transistors and capacitors in the solid-state Marx circuits, ten stages each, with an electrical equivalent circuit of the target, are presented, demonstrating both the improved voltage stability and pulse flexibility potential wanted for this new modulator.

  4. Acceptability and perceived utility of drone technology among emergency medical service responders and incident commanders for mass casualty incident management.

    Science.gov (United States)

    Hart, Alexander; Chai, Peter R; Griswold, Matthew K; Lai, Jeffrey T; Boyer, Edward W; Broach, John

    2017-01-01

    This study seeks to understand the acceptability and perceived utility of unmanned aerial vehicle (UAV) technology to Mass Casualty Incidents (MCI) scene management. Qualitative questionnaires regarding the ease of operation, perceived usefulness, and training time to operate UAVs were administered to Emergency Medical Technicians (n = 15). A Single Urban New England Academic Tertiary Care Medical Center. Front-line emergency medical service (EMS) providers and senior EMS personnel in Incident Commander roles. Data from this pilot study indicate that EMS responders are accepting to deploying and operating UAV technology in a disaster scenario. Additionally, they perceived UAV technology as easy to adopt yet impactful in improving MCI scene management.

  5. 26Al tracer experiment by accelerator mass spectrometry and its application to the studies for amyotrophic lateral sclerosis and Alzheimer's disease, 1

    International Nuclear Information System (INIS)

    Kobayashi, Koichi; Yumoto, Sakae; Nagai, Hisao; Hosoyama, Yoshiyuki; Imamura, Mineo; Masuzawa, Shin-ichirou; Koizumi, Yoshinobu; Yamashita, Hiroshi.

    1990-01-01

    Accelerator mass spectrometry (AMS) was applied for 26 Al tracer experiment to study the aluminum toxicity and metabolism in rats. To investigate the cause of amyotrophic lateral sclerosis (ALS) and Alzheimer's disease, the aluminum incorporation into the brain (cerebrum) was studied by AMS using 26 Al as a tracer. When 26 Al was intraperitoneally injected into rats, a considerable amount of 26 Al was incorporated into the cerebrum after 5-35 days of the injection. (author)

  6. THE UTILIZATION OF ACHATINA FULICA MUCUS IN ALGINATE MEMBRANE AS WOUND HEALING ACCELERATOR AND ANTI- INFECTION MATERIAL

    Directory of Open Access Journals (Sweden)

    Fatkhunisa Rahmawati

    2014-01-01

    Full Text Available Wound should be covered with bandage that is called wound dressing. Most people use synthetic materials such as gauze dressing. Gauze has high absorption of NaCl, which is often used to cleanse the wound. However, discomfort and pain arise since the gauze becomes sticky on the wound. Therefore, we need other alternatives instead of gauze to cover wound. One such alternative is the alginate membrane. This study used alginate membrane with mixture of mucous of the snail Achatina fulica, which contain proteins such as proline, serine asparagine, glycosaminoglycan, hydroxylysine, trionin and so forth, to activate the growth factor. Alginate powder and carboxymethl cellulose (CMC was dissolved in distilled water mixed with mucus of the snail Achatina fulica in four variations (4:0; 4:1, 4:2, 4:3 through a magnetic stirrer, and casted on a baking sheet covered with sterile gauze. High Performance Liquid Chromatography (HPLC test showed that the glycosaminoglycan content was found on the mucous of Achatina fulica. This was indicated by the appearance of peak at 325–350 second. The most optimum alginate and mucus composition was in ratio of 4:2. This ratio resulted in a wound dressing that was still able to absorb the exudate and optimally accelerated wound healing.

  7. Observational infant exploratory [14C]-paracetamol pharmacokinetic microdose/therapeutic dose study with accelerator mass spectrometry bioanalysis

    Science.gov (United States)

    Garner, Colin R; Park, Kevin B; French, Neil S; Earnshaw, Caroline; Schipani, Alessandro; Selby, Andrew M; Byrne, Lindsay; Siner, Sarah; Crawley, Francis P; Vaes, Wouter H J; van Duijn, Esther; deLigt, Rianne; Varendi, Heili; Lass, Jane; Grynkiewicz, Grzegorz; Maruszak, Wioletta; Turner, Mark A

    2015-01-01

    Aims The aims of the study were to compare [14C]-paracetamol ([14C]-PARA) paediatric pharmacokinetics (PK) after administration mixed in a therapeutic dose or an isolated microdose and to develop further and validate accelerator mass spectrometry (AMS) bioanalysis in the 0–2 year old age group. Methods [14C]-PARA concentrations in 10–15 µl plasma samples were measured after enteral or i.v. administration of a single [14C]-PARA microdose or mixed in with therapeutic dose in infants receiving PARA as part of their therapeutic regimen. Results Thirty-four infants were included in the PARA PK analysis for this study: oral microdose (n = 4), i.v. microdose (n = 6), oral therapeutic (n = 6) and i.v. therapeutic (n = 18). The respective mean clearance (CL) values (SDs in parentheses) for these dosed groups were 1.46 (1.00) l h–1, 1.76 (1.07) l h–1, 2.93 (2.08) l h–1 and 2.72 (3.10) l h–1, t1/2 values 2.65 h, 2.55 h, 8.36 h and 7.16 h and dose normalized AUC(0-t) (mg l–1 h) values were 0.90 (0.43), 0.84 (0.57), 0.7 (0.79) and 0.54 (0.26). Conclusions All necessary ethical, scientific, clinical and regulatory procedures were put in place to conduct PK studies using enteral and systemic microdosing in two European centres. The pharmacokinetics of a therapeutic dose (mg kg–1) and a microdose (ng kg–1) in babies between 35 to 127 weeks post-menstrual age. [14C]-PARA pharmacokinetic parameters were within a two-fold range after a therapeutic dose or a microdose. Exploratory studies using doses significantly less than therapeutic doses may offer ethical and safety advantages with increased bionalytical sensitivity in selected exploratory paediatric pharmacokinetic studies. PMID:25619398

  8. Observational infant exploratory [(14)C]-paracetamol pharmacokinetic microdose/therapeutic dose study with accelerator mass spectrometry bioanalysis.

    Science.gov (United States)

    Garner, Colin R; Park, Kevin B; French, Neil S; Earnshaw, Caroline; Schipani, Alessandro; Selby, Andrew M; Byrne, Lindsay; Siner, Sarah; Crawley, Francis P; Vaes, Wouter H J; van Duijn, Esther; deLigt, Rianne; Varendi, Heili; Lass, Jane; Grynkiewicz, Grzegorz; Maruszak, Wioletta; Turner, Mark A

    2015-07-01

    The aims of the study were to compare [(14)C]-paracetamol ([(14)C]-PARA) paediatric pharmacokinetics (PK) after administration mixed in a therapeutic dose or an isolated microdose and to develop further and validate accelerator mass spectrometry (AMS) bioanalysis in the 0-2 year old age group. [(14)C]-PARA concentrations in 10-15 µl plasma samples were measured after enteral or i.v. administration of a single [(14)C]-PARA microdose or mixed in with therapeutic dose in infants receiving PARA as part of their therapeutic regimen. Thirty-four infants were included in the PARA PK analysis for this study: oral microdose (n = 4), i.v. microdose (n = 6), oral therapeutic (n = 6) and i.v. therapeutic (n = 18). The respective mean clearance (CL) values (SDs in parentheses) for these dosed groups were 1.46 (1.00) l h(-1), 1.76 (1.07) l h(-1), 2.93 (2.08) l h(-1) and 2.72 (3.10) l h(-1), t(1/2) values 2.65 h, 2.55 h, 8.36 h and 7.16 h and dose normalized AUC(0-t) (mg l(-1) h) values were 0.90 (0.43), 0.84 (0.57), 0.7 (0.79) and 0.54 (0.26). All necessary ethical, scientific, clinical and regulatory procedures were put in place to conduct PK studies using enteral and systemic microdosing in two European centres. The pharmacokinetics of a therapeutic dose (mg kg(-1)) and a microdose (ng kg(-1)) in babies between 35 to 127 weeks post-menstrual age. [(14)C]-PARA pharmacokinetic parameters were within a two-fold range after a therapeutic dose or a microdose. Exploratory studies using doses significantly less than therapeutic doses may offer ethical and safety advantages with increased bionalytical sensitivity in selected exploratory paediatric pharmacokinetic studies. © 2015 The British Pharmacological Society.

  9. Analysis of 14C-bearing compounds released by the corrosion of irradiated steel using accelerator mass spectrometry.

    Science.gov (United States)

    Cvetković, B Z; Salazar, G; Kunz, D; Szidat, S; Wieland, E

    2018-06-25

    The combination of ion chromatography (IC) with accelerator mass spectrometry (AMS) was developed to determine the speciation of 14C-(radiocarbon) bearing organic compounds in the femto to pico molar concentration range. The development of this compound-specific radiocarbon analysis (CSRA) of carboxylic acids is reported and the application of the method on a leaching solution from neutron-irradiated steel is demonstrated. The background and the dynamic range of the AMS-based method were quantified. On using 14C-labelled standards, the measurements demonstrate the repeatability of the analytical method and the reproducible recovery of the main target carboxylic acids (i.e., acetate, formate, malonate, and oxalate). The detection limit was determined to be in the mid fmol 14C per L level while the dynamic range of the analytical method covers three orders of magnitude from the low fmol to the mid pmol 14C per L level. Cross contamination was found to be negligible during IC fractionation and was accounted for during eluate processing and 14C detection by AMS. The 14C-bearing carboxylates released from an irradiated steel nut into an alkaline leaching solution were analysed using the CSRA-based analytical method with the aim to check the applicability of the approach and develop appropriate sample preparation. The concentrations of 14C-bearing formate and acetate, the main organic corrosion products, were at a low pmol 14C per L level for convenient dimensions of the alkaline leaching experiment which demonstrates that compound-specific 14C AMS is an extremely sensitive analytical method for analysing 14C-bearing compounds. The content of total organic 14C in solution (TO14C) determined by the direct measurement of an aliquot of the leaching solution agrees well with the sum of the 14C concentrations of the individual carboxylates within the uncertainty of the data. Furthermore, the TO14C content is in good agreement with the calculated value using the corrosion rate

  10. Gas Chromatographic Mass Spectrometric Determination of Myo-inositol in Humans Utilizing a Deuterated Internal Standard

    DEFF Research Database (Denmark)

    Andersen, Jan Rud; Larsen, Elfinn; Harbo, Helge

    1982-01-01

    The isotopic dilution technique was used for determining the content of myo-inositol in human urine, plasma and haemolysed erythrocyte samples. A deuterated myo-inositol, synthesized from inosose-2 by base-catalysed exchange of hydrogens by deuterium, followed by reduction of the inosose with 2H2......, was added as internal standard to the samples at an early stage in the analytical procedure. After separation and derivatization to the hexa-acetate, the gas chromatographic mass spectrometric analysis was carried out. A 25 m fused silica capillary column coated with methyl silicone was used, and the ions...... selected for monitoring were m/z 210 and m/z 214, which are characteristic and abundant fragment ions from unlabelled and hexadeuterated myo-inositolhexa-acetate, respectively. Calibration curves from water, urine, plasma and haemolysed erythrocytes show parallel, linear responses in the ratio between...

  11. Development of low thermal mass cement-sand block utilizing peat soil and effective microorganism

    Directory of Open Access Journals (Sweden)

    Irham Hameeda Mohamad Idris

    2018-06-01

    Full Text Available The development of low thermal mass cement-sand block by incorporating peat soil and Effective Microorganism (EM was studied systematically. In total, seven mixtures of cement-sand block targeted at a 28-days compressive strength of 7 MPa are designed. One control sample is made with a water/cement ratio (w/c of 0.5, three mixes using 3%, 6% and 10% peat soil replacing sand and three mixes using 10%, 20% and 30% EM replacing water. Modified blocks with 6% of peat soil and 30% of EM are the most optimum blocks to be used in the construction of masonry as they successfully reduced the thermal conductivity of the blocks with the value of 1.275 W/mK and 1.792 W/mK respectively when being compared to the thermal conductivity of the control sample which is 2.400 W/mK. Besides, they are also able to achieve higher strength than the desired compressive strength which is 7 MPa. The compressive strength of the samples with 6% of peat soil is 16.48 MPa at 28-days while 30.39 MPa for samples with 30% of EM. On the other hand, the water absorption rate of samples with 6% of peat soil is 7.6% while 6.1% for samples with 30% EM and both are okay since their rate of water absorption is lower than 20%. In conclusion, the addition of peat soil and EM in the cement-sand mix show promising performance as a low cost material to produce low thermal mass cement-sand block. Keywords: Effective microorganism, Peat soil, Thermal conductivity, Cement brick

  12. Variable Acceleration Force Calibration System (VACS)

    Science.gov (United States)

    Rhew, Ray D.; Parker, Peter A.; Johnson, Thomas H.; Landman, Drew

    2014-01-01

    Conventionally, force balances have been calibrated manually, using a complex system of free hanging precision weights, bell cranks, and/or other mechanical components. Conventional methods may provide sufficient accuracy in some instances, but are often quite complex and labor-intensive, requiring three to four man-weeks to complete each full calibration. To ensure accuracy, gravity-based loading is typically utilized. However, this often causes difficulty when applying loads in three simultaneous, orthogonal axes. A complex system of levers, cranks, and cables must be used, introducing increased sources of systematic error, and significantly increasing the time and labor intensity required to complete the calibration. One aspect of the VACS is a method wherein the mass utilized for calibration is held constant, and the acceleration is changed to thereby generate relatively large forces with relatively small test masses. Multiple forces can be applied to a force balance without changing the test mass, and dynamic forces can be applied by rotation or oscillating acceleration. If rotational motion is utilized, a mass is rigidly attached to a force balance, and the mass is exposed to a rotational field. A large force can be applied by utilizing a large rotational velocity. A centrifuge or rotating table can be used to create the rotational field, and fixtures can be utilized to position the force balance. The acceleration may also be linear. For example, a table that moves linearly and accelerates in a sinusoidal manner may also be utilized. The test mass does not have to move in a path that is parallel to the ground, and no re-leveling is therefore required. Balance deflection corrections may be applied passively by monitoring the orientation of the force balance with a three-axis accelerometer package. Deflections are measured during each test run, and adjustments with respect to the true applied load can be made during the post-processing stage. This paper will

  13. Acceleration of peat drying by intensifying the heat and mass transfer; Turpeen kuivumisen nopeuttaminen laemmoen- ja aineensiirtoa tehostamalla

    Energy Technology Data Exchange (ETDEWEB)

    Hillebrand, K.

    1996-12-31

    The efficiency of peat production can be increased by intensifying peat drying. To intensify drying one has to know the effects of the different factors affecting the heat and mass transfer in the drying layer and in the soil. The objective of the study is to increase the degree of utilization of solar energy in drying of peat from the present level of 30% to 40% of the total incoming solar energy. In this way it is possible to reduce the peat production costs about 10%. A numerical drying model has been developed which describes the transfer of liquid water, water vapor and heat in the drying layer and in the soil. In addition, the interaction between the atmosphere and the drying layer, as well as the rainfall interception by the layer, infiltration, evaporation, and drainage have been taking into account. Daily input requirements include global solar radiation, air temperature and relative humidity, wind speed and precipitation. In addition to the weather data one has to know the characteristics of the drying layer and the soil. The numerical drying model was also used to study the effect of soil frost on peat drying and the possibilities to hinder the frost formation. Producing peat on the field which is still partly frozen, the drying of peat takes 10 - 25% longer time than under normal conditions, which means 5 - 25 hours longer drying period. By forming a porous, insulating layer on the top of the soil surface, one can hinder the frost formation significantly. Raising the groundwater level prevents, however, only a little the frost formation in peat soil

  14. Utilization of Mass Media and Effects for Developing Women’s Health

    Directory of Open Access Journals (Sweden)

    Sema Ozbas

    2010-10-01

    Full Text Available Women's health, family and society resulting from psycho-social factors, women's individual health status, fertility behavior, such as the quality of health services are affected by many factors. Factors that affect health because they are many and various, to develop health strategies and actions are also many and varied. Therefore, the development of health issue, not only the health sector, many sectors of the business. One of the most important of these sectors is the media. Women how to mass media can reach, when they choose what is, and these preferences in women's health in developing discuss how the effective use of women in this study visual media to reach out difficulties they were experiencing. Especially in rural areas, it is observed more pronounced. Women in the use of the media gather useful information, they apply this knowledge in the development of their health and it was concluded that the media would be effective. [TAF Prev Med Bull 2010; 9(5.000: 541-546

  15. Utility of Body Mass Index in Identifying Excess Adiposity in Youth Across the Obesity Spectrum.

    Science.gov (United States)

    Ryder, Justin R; Kaizer, Alexander M; Rudser, Kyle D; Daniels, Stephen R; Kelly, Aaron S

    2016-10-01

    To determine the proportion of youth within a given body mass index (BMI) obesity category with excess adiposity using dual energy x-ray absorptiometry (DXA). Furthermore, to examine whether mean differences in cardiometabolic risk factors based upon various excess adiposity cutpoints were present. DXA data from the National Health and Nutrition Examination Survey 1999-2006 (n = 10 465; 8-20 years of age) were used for this analysis. Obesity categories were defined using Centers for Disease Control and prevention definitions for age and sex. Excess adiposity was defined using cohort-specific cutpoints at 75th, 85th, and 90th percentiles of DXA body fat (%) by age and sex using quantile regression models. Additionally, we examined differences in cardiometabolic risk factors among youth (BMI percentile >85th) above and below various excess adiposity cutpoints. Nearly all youth with class 3 obesity (100% male, 100% female; 97% male, 99% female; and 95% male, 96% female; using the 75th, 85th, and 90th DXA percentiles, respectively) and a high proportion of those with class 2 obesity (98% male, 99% female; 92% male, 91% female; and 76% male, 76% female) had excess adiposity. Significant discordance was observed between BMI categorization and DXA-derived excess adiposity among youth with class 1 obesity or overweight. Elevated cardiometabolic risk factors were present in youth with excess adiposity, regardless of the cutpoint used. BMI correctly identifies excess adiposity in most youth with class 2 and 3 obesity but a relatively high degree of discordance was observed in youth with obesity and overweight. Cardiometabolic risk factors are increased in the presence of excess adiposity, regardless of the cutpoint used. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. The effect of different acid-treatments on the age spectrum of organic matter in sediments determined by Ramped PyrOx/accelerator mass spectrometry

    Science.gov (United States)

    McNichol, A. P.; Bao, R.

    2016-02-01

    Studies of the radiocarbon and stable carbon isotopes of organic matter (OM) in sediments have become common and are an effective way to understand the fate of sedimentary OM burial in the aquatic environment. In practice, obtaining the radiocarbon and stable carbon isotopic composition in sediments requires first removing inorganic carbon by acid treatment. Two common treatments are acid rinsing and fumigation. The radiocarbon ages and stable carbon isotopic values obtained using the different acid-treatments can differ significantly, but the details of the change of organic components have received much less attention. A new approach was recently developed for radiocarbon dating of carbonate -poor and/or rich sediments using a so-called ramped pyrolysis/oxidation ("Ramped PyrOx") method in combination with accelerator mass spectrometry. Radiocarbon and stable carbon isotopic analysis of the CO2 that evolves under a linear temperature program allows separation of OC components in sediments based on their thermochemical stability (Rosenheim et al., 2008). In this preliminary study, we explore the utility of the Ramped PyrOx method for determining the effect of different acid-treatments on radiocarbon ages and carbon isotopic compositions of OM in sediments. The observations indicate that the HCl rinsing method alters OM more than fumigation in lower carbonate samples while the opposite occurs in the high carbonate samples. This result has implications for studies of the transfer of carbon from the terrestrial to the marine environment because these are samples that contain low amounts of carbonate material. Recommendations for the most appropriate way to treat these samples will be made. The loss of organic matter during the HCl rinsing in the marine carbonate poor sediments could be one of the reasons that radiocarbon ages in the labile thermal fractions were older than that processed by fumigation, whereas younger in the resistant thermal fractions. The distinct

  17. Quantification of absorption, retention and elimination of two different oral doses of vitamin A in Zambian boys using accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Aklamati, E K; Mulenga, M; Dueker, S R; Buchholz, B A; Peerson, J M; Kafwembe, E; Brown, K H; Haskell, M J

    2009-10-12

    A recent survey indicated that high-dose vitamin A supplements (HD-VAS) had no apparent effect on vitamin A (VA) status of Zambian children <5 y of age. To explore possible reasons for the lack of response to HD-VAS among Zambian children, we quantified the absorption, retention, and urinary elimination of either a single HDVAS (60 mg) or a smaller dose of stable isotope (SI)-labeled VA (5 mg), which was used to estimate VA pool size, in 3-4 y old Zambian boys (n = 4 for each VA dose). A 25 nCi tracer dose of [{sup 14}C{sub 2}]-labeled VA was co-administered with the HD-VAS or SI-labeled VA, and 24-hr stool and urine samples were collected for 3 and 7 consecutive days, respectively, and 24-hr urine samples at 4 later time points. Accelerator Mass Spectrometry (AMS) was used to measure the cumulative excretion of {sup 14}C in stool and urine 3d after dosing to estimate, respectively, absorption and retention of the VAS and SI-labeled VA. The urinary elimination rate (UER) was estimated by plotting {sup 14}C in urine vs. time, and fitting an exponential equation to the data. Estimates of mean absorption, retention and the UER were 83.8 {+-} 7.1%, 76.3 {+-} 6.7%, and 1.9 {+-} 0.6%/d, respectively, for the HD-VAS and 76.5 {+-} 9.5%, 71.1 {+-} 9.4%, and 1.8 {+-} 1.2%/d, respectively for the smaller dose of SI-labeled VA. Estimates of absorption, retention and the UER did not differ by size of the VA dose administered (P=0.26, 0.40, 0.88, respectively). Estimated absorption and retention were negatively associated with reported fever (P=0.011) and malaria (P =0.010). HD-VAS and SI-labeled VA were adequately absorbed, retained and utilized in apparently healthy Zambian preschool-age boys, although absorption and retention may be affected by recent infections.

  18. Predictive utility of blood pressure, waist circumference and body mass index for metabolic syndrome in patients with schizophrenia in Singapore.

    Science.gov (United States)

    Nurjono, Milawaty; Lee, Jimmy

    2013-05-01

    This study aims to examine and compare the predictive utility of blood pressure (BP), waist circumference (WC) and body mass index (BMI), and to determine optimal cut-off values in prediction of metabolic syndrome (MetS) in patients with chronic schizophrenia. About 100 patients with chronic schizophrenia were recruited. BMI and BP were measured and laboratory tests to evaluate patients' high-density lipoprotein cholesterol, triglycerides and glucose levels were performed. Presence of MetS was examined according to AHA/NHLBI guidelines. Predictive utility of BP, WC and BMI was examined using receiver operating curve and discriminant indices were determined accordingly. Forty-six (46%) patients were identified to have MetS. BMI of ≥23 kg m(-2) was most accurate (AUC = 0.83, P < 0.001), with sensitivity of 93.5%, specificity of 48.1%, positive predictive value of 60.6% and negative predictive value of 92.9% in identifying MetS. This finding has immediate and significant clinical implications in the local population with schizophrenia. © 2012 Wiley Publishing Asia Pty Ltd.

  19. LEPTON ACCELERATION IN THE VICINITY OF THE EVENT HORIZON: HIGH-ENERGY AND VERY-HIGH-ENERGY EMISSIONS FROM ROTATING BLACK HOLES WITH VARIOUS MASSES

    Energy Technology Data Exchange (ETDEWEB)

    Hirotani, Kouichi; Pu, Hung-Yi; Lin, Lupin Chun-Che; Inoue, Makoto; Matsushita, Satoki [Academia Sinica, Institute of Astronomy and Astrophysics (ASIAA), P.O. Box 23-141, Taipei, Taiwan 10617, R.O.C. (China); Chang, Hsiang-Kuang; Kong, Albert K. H. [Department of Physics, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu, Taiwan 30013, R.O.C. (China); Tam, Pak-Hin T., E-mail: hirotani@tiara.sinica.edu.tw [School of Physics and Astronomy, Sun Yat-Sen University, Zhuhai 519082 (China)

    2016-12-20

    We investigate the electrostatic acceleration of electrons and positrons in the vicinity of the event horizon, applying the pulsar outer-gap model to black hole (BH) magnetospheres. During a low accretion phase, the radiatively inefficient accretion flow (RIAF) cannot emit enough MeV photons that are needed to sustain the force-free magnetosphere via two-photon collisions. In such a charge-starved region (or a gap), an electric field arises along the magnetic field lines to accelerate electrons and positrons into ultra-relativistic energies. These relativistic leptons emit copious gamma rays via curvature and inverse-Compton (IC) processes. Some of such gamma rays collide with the submillimeter-IR photons emitted from the RIAF to materialize as pairs, which polarize to partially screen the original acceleration electric field. It is found that the gap gamma-ray luminosity increases with decreasing accretion rate. However, if the accretion rate decreases too much, the diminished RIAF soft photon field can no longer sustain a stationary pair production within the gap. As long as a stationary gap is formed, the magnetosphere becomes force-free outside the gap by the cascaded pairs, irrespective of the BH mass. If a nearby stellar-mass BH is in quiescence, or if a galactic intermediate-mass BH is in a very low accretion state, its curvature and IC emissions are found to be detectable with Fermi /LAT and imaging atmospheric Cherenkov telescopes (IACT). If a low-luminosity active galactic nucleus is located within about 30 Mpc, the IC emission from its supermassive BH is marginally detectable with IACT.

  20. Advanced accelerator research and development

    International Nuclear Information System (INIS)

    Anon.

    1974-01-01

    Research and development on the Positron-Electron Project (PEP), the electron rings, the superconducting accelerator (ESCAR), and the superconductivity program are reported. Efforts relating to the proposed PEP include work on: (1) the injection system; (2) the rf system; (3) the main-ring bend magnets; (4) the magnet power supplies and controls; (5) alignment; (6) radiation and shielding; (7) the vacuum system; and (8) conventional facilities (utilities, etc.). Experimental and theoretical work continued on the development of suitably intense electron rings as vehicles for the collective acceleration of ions. The most difficult problem was found to be the longitudinal (negative mass) instability. Design work was begun for ESCAR (Experimental Superconducting Accelerating Ring), a small proton synchrotron and storage ring using superconducting magnets, which should aid in the design of future large superconducting facilities. Magnet development was largely directed toward the detailed design of the dipole units. A superconducting beam transport line was installed at the Bevatron. (PMA)

  1. Analysis of vitamin K-1 in fruits and vegetables using accelerated solvent extraction and liquid chromatography tandem mass spectrometry with atmospheric pressure chemical ionization

    DEFF Research Database (Denmark)

    Jäpelt, Rie Bak; Jakobsen, Jette

    2016-01-01

    The objective of this study was to develop a rapid, sensitive, and specific analytical method to study vitamin K-1 in fruits and vegetables. Accelerated solvent extraction and solid phase extraction was used for sample preparation. Quantification was done by liquid chromatography tandem mass...... spectrometry with atmospheric pressure chemical ionization in selected reaction monitoring mode with deuterium-labeled vitamin K1 as an internal standard. The precision was estimated as the pooled estimate of three replicates performed on three different days for spinach, peas, apples, banana, and beetroot...

  2. Preliminary design report of a relativistic-Klystron two-beam-accelerator based power source for a 1 TeV center-of-mass next linear collider

    International Nuclear Information System (INIS)

    Yu, S.; Goffeney, N.; Henestroza, E.

    1995-01-01

    A preliminary point design for an 11.4 GHz power source for a 1 TeV center-of-mass Next Linear Collider (NLC) based on the Relativistic-Klystron Two-Beam-Accelerator (RK-TBA) concept is presented. The present report is the result of a joint LBL-LLNL systems study. consisting of three major thrust areas: physics, engineering, and costing. The new RK-TBA point design, together with our findings in each of these areas, are reported

  3. sup 26 Al tracer experiment by accelerator mass spectrometry and its application to the studies for amyotrophic lateral sclerosis and Alzheimer's disease, 1

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Koichi (Tokyo Univ. (Japan). Research Center for Nuclear Science and Technology); Yumoto, Sakae; Nagai, Hisao; Hosoyama, Yoshiyuki; Imamura, Mineo; Masuzawa, Shin-ichirou; Koizumi, Yoshinobu; Yamashita, Hiroshi

    1990-12-01

    Accelerator mass spectrometry (AMS) was applied for {sup 26}Al tracer experiment to study the aluminum toxicity and metabolism in rats. To investigate the cause of amyotrophic lateral sclerosis (ALS) and Alzheimer's disease, the aluminum incorporation into the brain (cerebrum) was studied by AMS using {sup 26}Al as a tracer. When {sup 26}Al was intraperitoneally injected into rats, a considerable amount of {sup 26}Al was incorporated into the cerebrum after 5-35 days of the injection. (author).

  4. Accelerators and Dinosaurs

    CERN Multimedia

    Turner, Michael Stanley

    2003-01-01

    Using naturally occuring particles on which to research might have made accelerators become extinct. But in fact, results from astrophysics have made accelerator physics even more important. Not only are accelerators used in hospitals but they are also being used to understand nature's inner workings by searching for Higgs bosons, CP violation, neutrino mass and dark matter (2 pages)

  5. An Energy Upgrade of REX-ISOLDE to 3.1 MeV/u and Acceleration of Heavier Masses up to $A$=150.

    CERN Multimedia

    Wenander, F J C

    2002-01-01

    With an additional 9-gap resonator, operated at 202.56 MHz, the maximum beam energy of REX-ISOLDE will be increased from 2.2 MeV/u to 3.1 MeV/u. This enlarges considerably the range of mass numbers of projectiles reaching the Coulomb barrier for nuclear reactions. Acceleration of heavier projectiles, however, requires longer charge breeding times leading to smaller pulse repetition rates. Thus EBIS developments aiming at shorter breeding times by using higher electron beam current densities are foreseen. Moreover, longer breeding times require longer accumulation times and larger ion storage capacities in REXTRAP to maintain the beam intensities, which will be reached by using new cooling techniques. Although various optimization steps can be performed with ion sources local to REX-ISOLDE, a commissioning of the modified REX-ISOLDE with ISOLDE beams of heavier masses with 15 shifts is requested.

  6. Accelerated identification of proteins by mass spectrometry by employing covalent pre-gel staining with Uniblue A.

    Directory of Open Access Journals (Sweden)

    Marco A Mata-Gómez

    Full Text Available BACKGROUND: The identification of proteins by mass spectrometry is a standard method in biopharmaceutical quality control and biochemical research. Prior to identification by mass spectrometry, proteins are usually pre-separated by electrophoresis. However, current protein staining and de-staining protocols are tedious and time consuming, and therefore prolong the sample preparation time for mass spectrometry. METHODOLOGY AND PRINCIPAL FINDINGS: We developed a 1-minute covalent pre-gel staining protocol for proteins, which does not require de-staining before the mass spectrometry analysis. We investigated the electrophoretic properties of derivatized proteins and peptides and studied their behavior in mass spectrometry. Further, we elucidated the preferred reaction of proteins with Uniblue A and demonstrate the integration of the peptide derivatization into typical informatics tools. CONCLUSIONS AND SIGNIFICANCE: The Uniblue A staining method drastically speeds up the sample preparation for the mass spectrometry based identification of proteins. The application of this chemo-proteomic strategy will be advantageous for routine quality control of proteins and for time-critical tasks in protein analysis.

  7. Verification of the sputter-generated {sup 32}SF{sub n}{sup −} (n = 1–6) anions by accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Mane, R.G.; Surendran, P. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kumar, Sanjay [Physics Department, Agra College Agra, Agra 282002 (India); Nair, J.P.; Yadav, M.L. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Hemalatha, M. [UM-DAE Centre for Excellence in Basic Sciences, Mumbai 400098 (India); Thomas, R.G.; Mahata, K. [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kailas, S. [UM-DAE Centre for Excellence in Basic Sciences, Mumbai 400098 (India); Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Gupta, A.K., E-mail: anit@tifr.res.in [Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2016-01-01

    Recently, we have performed systematic Secondary Ion Mass Spectrometry (SIMS) measurements at our ion source test set up and have demonstrated that gas phase {sup 32}SF{sub n}{sup −} (n = 1–6) anions for all size ‘n’ can be readily generated from a variety of surfaces undergoing Cs{sup +} ion sputtering in the presence of high purity SF{sub 6} gas by employing the gas spray-cesium sputter technique. In our SIMS measurements, the isotopic yield ratio {sup 34}SF{sub n}{sup −}/{sup 32}SF{sub n}{sup −} (n = 1–6) was found to be close to its natural abundance but not for all size ‘n’. In order to gain further insight into the constituents of these molecular anions, ultra sensitive Accelerator Mass Spectrometry (AMS) measurements were conducted with the most abundant {sup 32}SF{sub n}{sup −} (n = 1–6) anions, at BARC-TIFR 14 UD Pelletron accelerator. The results from these measurements are discussed in this paper.

  8. Reconciling ocean mass content change based on direct and inverse approaches by utilizing data from GRACE, altimetry and Swarm

    Science.gov (United States)

    Rietbroek, R.; Uebbing, B.; Lück, C.; Kusche, J.

    2017-12-01

    Ocean mass content (OMC) change due to the melting of the ice-sheets in Greenland and Antarctica, melting of glaciers and changes in terrestrial hydrology is a major contributor to present-day sea level rise. Since 2002, the GRACE satellite mission serves as a valuable tool for directly measuring the variations in OMC. As GRACE has almost reached the end of its lifetime, efforts are being made to utilize the Swarm mission for the recovery of low degree time-variable gravity fields to bridge a possible gap until the GRACE-FO mission and to fill up periods where GRACE data was not existent. To this end we compute Swarm monthly normal equations and spherical harmonics that are found competitive to other solutions. In addition to directly measuring the OMC, combination of GRACE gravity data with altimetry data in a global inversion approach allows to separate the total sea level change into individual mass-driven and steric contributions. However, published estimates of OMC from the direct and inverse methods differ not only depending on the time window, but also are influenced by numerous post-processing choices. Here, we will look into sources of such differences between direct and inverse approaches and evaluate the capabilities of Swarm to derive OMC. Deriving time series of OMC requires several processing steps; choosing a GRACE (and altimetry) product, data coverage, masks and filters to be applied in either spatial or spectral domain, corrections related to spatial leakage, GIA and geocenter motion. In this study, we compare and quantify the effects of the different processing choices of the direct and inverse methods. Our preliminary results point to the GIA correction as the major source of difference between the two approaches.

  9. A High Molecular-Mass Anoxybacillus sp. SK3-4 Amylopullulanase: Characterization and Its Relationship in Carbohydrate Utilization

    Directory of Open Access Journals (Sweden)

    Kian Mau Goh

    2013-05-01

    Full Text Available An amylopullulanase of the thermophilic Anoxybacillus sp. SK3-4 (ApuASK was purified to homogeneity and characterized. Though amylopullulanases larger than 200 kDa are rare, the molecular mass of purified ApuASK appears to be approximately 225 kDa, on both SDS-PAGE analyses and native-PAGE analyses. ApuASK was stable between pH 6.0 and pH 8.0 and exhibited optimal activity at pH 7.5. The optimal temperature for ApuASK enzyme activity was 60 °C, and it retained 54% of its total activity for 240 min at 65 °C. ApuASK reacts with pullulan, starch, glycogen, and dextrin, yielding glucose, maltose, and maltotriose. Interestingly, most of the previously described amylopullulanases are unable to produce glucose and maltose from these substrates. Thus, ApuASK is a novel, high molecular-mass amylopullulanase able to produce glucose, maltose, and maltotriose from pullulan and starch. Based on whole genome sequencing data, ApuASK appeared to be the largest protein present in Anoxybacillus sp. SK3-4. The α-amylase catalytic domain present in all of the amylase superfamily members is present in ApuASK, located between the cyclodextrin (CD-pullulan-degrading N-terminus and the α-amylase catalytic C-terminus (amyC domains. In addition, the existence of a S-layer homology (SLH domain indicates that ApuASK might function as a cell-anchoring enzyme and be important for carbohydrate utilization in a streaming hot spring.

  10. Present status of the Tandetron Accelerator at Mutsu Establishment, JAEA

    International Nuclear Information System (INIS)

    Amano, Hikaru; Kabuto, Shoji; Kinoshita, Naoki; Suzuki, Takashi; Otosaka, Shigeyoshi; Kuwabara, Jun; Kitamura, Toshikatsu; Tanaka, Takayuki; Kitada, Yoshinobu; Watanabe, Yukiya

    2007-01-01

    The accelerator mass analyzer system at Mutsu Establishment, JAEA consists of a 3 MV tandem electrostatic accelerator and two beamlines for measuring isotope ratios of carbon and iodine. The present paper reports on (1) the operation and maintenance works in fiscal 2005, (2) the measurements of 14 C and 129 I and the related technology development, and (3) the public utilization of the system, which was started from 2006. (K.Y.)

  11. Accelerator microanalysis

    International Nuclear Information System (INIS)

    Tuniz, C.

    1997-01-01

    Particle accelerators have been developed more than sixty years ago to investigate nuclear and atomic phenomena. A major shift toward applications of accelerators in the study of materials structure and composition in inter-disciplinary projects has been witnessed in the last two decades. The Australian Nuclear Science and Technology Organisation (ANSTO) has developed advanced research programs based on the use of particle and photon beams. Atmospheric pollution problems are investigated at the 3 MV Van de Graff accelerator using ion beam analysis techniques to detect toxic elements in aerosol particles. High temperature superconductor and semiconductor materials are characterised using the recoil of iodine and other heavy ions produced at ANTARES, the 10-MV Tandem accelerator. A heavy-ion microprobe is presently being developed at ANTARES to map elemental concentrations of specific elements with micro-size resolution. An Accelerator mass Spectrometry (AMS) system has been developed at ANSTO for the ultra-sensitive detection of Carbon-14, Iodine-129 and other long-lived radioisotopes. This AMS spectrometer is a key instrument for climate change studies and international safeguards. ANSTO is also managing the Australian Synchrotron Research program based on facilities developed at the Photon Factory (Japan) and at the Advanced Photon Source (USA). Advanced projects in biology, materials chemistry, structural condensed matter and other disciplines are being promoted by a consortium involving Australian universities and research institutions. This paper will review recent advances in the use of particle accelerators, with a particular emphasis on applications developed at ANSTO and related to problems of international concern, such as global environmental change, public health and nuclear proliferation

  12. On the utility of GPU accelerated high-order methods for unsteady flow simulations: A comparison with industry-standard tools

    Science.gov (United States)

    Vermeire, B. C.; Witherden, F. D.; Vincent, P. E.

    2017-04-01

    First- and second-order accurate numerical methods, implemented for CPUs, underpin the majority of industrial CFD solvers. Whilst this technology has proven very successful at solving steady-state problems via a Reynolds Averaged Navier-Stokes approach, its utility for undertaking scale-resolving simulations of unsteady flows is less clear. High-order methods for unstructured grids and GPU accelerators have been proposed as an enabling technology for unsteady scale-resolving simulations of flow over complex geometries. In this study we systematically compare accuracy and cost of the high-order Flux Reconstruction solver PyFR running on GPUs and the industry-standard solver STAR-CCM+ running on CPUs when applied to a range of unsteady flow problems. Specifically, we perform comparisons of accuracy and cost for isentropic vortex advection (EV), decay of the Taylor-Green vortex (TGV), turbulent flow over a circular cylinder, and turbulent flow over an SD7003 aerofoil. We consider two configurations of STAR-CCM+: a second-order configuration, and a third-order configuration, where the latter was recommended by CD-adapco for more effective computation of unsteady flow problems. Results from both PyFR and STAR-CCM+ demonstrate that third-order schemes can be more accurate than second-order schemes for a given cost e.g. going from second- to third-order, the PyFR simulations of the EV and TGV achieve 75× and 3× error reduction respectively for the same or reduced cost, and STAR-CCM+ simulations of the cylinder recovered wake statistics significantly more accurately for only twice the cost. Moreover, advancing to higher-order schemes on GPUs with PyFR was found to offer even further accuracy vs. cost benefits relative to industry-standard tools.

  13. On the utility of GPU accelerated high-order methods for unsteady flow simulations: A comparison with industry-standard tools

    Energy Technology Data Exchange (ETDEWEB)

    Vermeire, B.C., E-mail: brian.vermeire@concordia.ca; Witherden, F.D.; Vincent, P.E.

    2017-04-01

    First- and second-order accurate numerical methods, implemented for CPUs, underpin the majority of industrial CFD solvers. Whilst this technology has proven very successful at solving steady-state problems via a Reynolds Averaged Navier–Stokes approach, its utility for undertaking scale-resolving simulations of unsteady flows is less clear. High-order methods for unstructured grids and GPU accelerators have been proposed as an enabling technology for unsteady scale-resolving simulations of flow over complex geometries. In this study we systematically compare accuracy and cost of the high-order Flux Reconstruction solver PyFR running on GPUs and the industry-standard solver STAR-CCM+ running on CPUs when applied to a range of unsteady flow problems. Specifically, we perform comparisons of accuracy and cost for isentropic vortex advection (EV), decay of the Taylor–Green vortex (TGV), turbulent flow over a circular cylinder, and turbulent flow over an SD7003 aerofoil. We consider two configurations of STAR-CCM+: a second-order configuration, and a third-order configuration, where the latter was recommended by CD-adapco for more effective computation of unsteady flow problems. Results from both PyFR and STAR-CCM+ demonstrate that third-order schemes can be more accurate than second-order schemes for a given cost e.g. going from second- to third-order, the PyFR simulations of the EV and TGV achieve 75× and 3× error reduction respectively for the same or reduced cost, and STAR-CCM+ simulations of the cylinder recovered wake statistics significantly more accurately for only twice the cost. Moreover, advancing to higher-order schemes on GPUs with PyFR was found to offer even further accuracy vs. cost benefits relative to industry-standard tools.

  14. On the utility of GPU accelerated high-order methods for unsteady flow simulations: A comparison with industry-standard tools

    International Nuclear Information System (INIS)

    Vermeire, B.C.; Witherden, F.D.; Vincent, P.E.

    2017-01-01

    First- and second-order accurate numerical methods, implemented for CPUs, underpin the majority of industrial CFD solvers. Whilst this technology has proven very successful at solving steady-state problems via a Reynolds Averaged Navier–Stokes approach, its utility for undertaking scale-resolving simulations of unsteady flows is less clear. High-order methods for unstructured grids and GPU accelerators have been proposed as an enabling technology for unsteady scale-resolving simulations of flow over complex geometries. In this study we systematically compare accuracy and cost of the high-order Flux Reconstruction solver PyFR running on GPUs and the industry-standard solver STAR-CCM+ running on CPUs when applied to a range of unsteady flow problems. Specifically, we perform comparisons of accuracy and cost for isentropic vortex advection (EV), decay of the Taylor–Green vortex (TGV), turbulent flow over a circular cylinder, and turbulent flow over an SD7003 aerofoil. We consider two configurations of STAR-CCM+: a second-order configuration, and a third-order configuration, where the latter was recommended by CD-adapco for more effective computation of unsteady flow problems. Results from both PyFR and STAR-CCM+ demonstrate that third-order schemes can be more accurate than second-order schemes for a given cost e.g. going from second- to third-order, the PyFR simulations of the EV and TGV achieve 75× and 3× error reduction respectively for the same or reduced cost, and STAR-CCM+ simulations of the cylinder recovered wake statistics significantly more accurately for only twice the cost. Moreover, advancing to higher-order schemes on GPUs with PyFR was found to offer even further accuracy vs. cost benefits relative to industry-standard tools.

  15. Insecticide-treated nets ownership and utilization among under-five children following the 2010 mass distribution in Burkina Faso.

    Science.gov (United States)

    Diabaté, Souleymane; Druetz, Thomas; Bonnet, Emmanuel; Kouanda, Seni; Ridde, Valéry; Haddad, Slim

    2014-09-04

    Periodic mass distributions contribute significantly to universal access to insecticide-treated nets (ITNs). However, due to the limited number of nets distributed, needs remain unsatisfied, particularly in large households. This study was conducted in Kaya health district following the 2010 mass distribution of ITNs in Burkina Faso. Data were collected on the socio-economic and geo-spatial characteristics and ITN possession and utilization levels of 2,004 households. The study explored: 1) ITN access, in terms of intra-household saturation with ITNs (households with at least one ITN for every two members) correctly installed and in very good physical condition; and 2) factors influencing the decision to place under-five children under a net. Particular attention was given to vector control activities undertaken by mothers. Of the 2,004 households, 90% possessed at least one ITN. However, intra-household saturation with ITNs was below 60% in small households and below 20% in large ones (>6 members). Crude proportion ratios comparing possession and levels of intra-household saturation with ITNs varied between 1.5 (small households) and 7.8 (large households). The proportions of households with ITNs for every two members that were correctly hung or in very good physical condition ranged from 0% to 6.5% in large households and 27.8% to 40.7% in small ones. ITN use to protect under-five children was lower in large households; it was significantly higher when there was at least one ITN for every two members. In large households, it was significantly higher when a child had experienced an episode of any illness in the previous two weeks and when the mother had taken actions to control vector proliferation. In small households, ITN use was significantly higher in families with agricultural land and children aged 12-23 months. Ownership rates were high, but real access to bed nets remained limited. The allocation process disadvantages large families. Real access to bed

  16. Clinical utility of dual-energy contrast-enhanced spectral mammography for breast microcalcifications without associated mass: a preliminary analysis.

    Science.gov (United States)

    Cheung, Yun-Chung; Tsai, Hsiu-Pei; Lo, Yung-Feng; Ueng, Shir-Hwa; Huang, Pei-Chin; Chen, Shin-Chih

    2016-04-01

    To assess the utility of dual-energy contrast-enhanced spectral mammography (DE-CESM) for evaluation of suspicious malignant microcalcifications. Two hundred and fifty-six DE-CESMs were reviewed from 2012-2013, 59 cases fulfilled the following criteria and were enrolled for analysis: (1) suspicious malignant microcalcifications (BI-RADS 4) on mammogram, (2) no related mass, (3) with pathological diagnoses. The microcalcification morphology and associated enhancement were reviewed to analyse the accuracy of the diagnosis and cancer size measurements versus the results of pathology. Of the 59 microcalcifications, 22 were diagnosed as cancers, 19 were atypical lesions and 18 were benign lesions. Twenty (76.9 %) cancers, three (11.55 %) atypia and three (11.55 %) benign lesions revealed enhancement. The true-positive rate of intermediate- and high-concern microcalcifications was significantly higher than that of low-concern lesions (93.75 % vs. 50 %). Overall, the diagnostic sensitivity of enhancement was 90.9 %, with 83.78 % specificity, 76.92 % positive predictive value, 93.94 % negative predictive value and 86.4 % accuracy. Performance was good (AUC = 0.87) according to a ROC curve and cancer size correlation with a mean difference of 0.05 cm on a Bland-Altman plot. DE-CESM provides additional enhancement information for diagnosing breast microcalcifications and measuring cancer sizes with high correlation to surgicohistology. • DE-CESM provides additional enhancement information for diagnosing suspicious breast microcalcifications. • The enhanced cancer size closely correlates to microscopy by Bland-Altman plot. • DE-CESM could be considered for evaluation of suspicious malignant microcalcifications.

  17. Development of a method to measure the concentration of 14C in the stack air of nuclear power plants by accelerator mass spectrometry (AMS)

    International Nuclear Information System (INIS)

    Stenstroem, K.; Erlandsson, B.; Hellborg, R.; Haakansson, K.; Wiebert, A.; Skog, G.

    1993-04-01

    C-14, a pure low-energetic beta-emitter, is produced through various nuclear reactions in nuclear power plants. Some of this C-14 is air-borne and is transported via the ventilation system through the stack of the power station and is integrated in living matter in the surroundings of the plant. The long half-life of the isotope (T1/2=5730 years) and the biological importance of carbon may lead to a not negligible contribution of the radiation dose for those living in the neighbourhood of nuclear power plants. C-14 has earlier been measured radiometrically with mainly two different methods, using proportional counters or liquid scintillators. In this report a new method is described, using an accelerator based technique. accelerator mass spectrometry (AMS). This technique has at least three advantages over the radiometrical methods. It requires only a few litres of gas per sample, which is 100-1000 times less compared to the radiometrical methods. It is insensitive to the beta and gamma rays from other radioactive isotopes in the stack air. The measuring time with AMS, about 20 minutes per sample, is considerably shorter compared to the radiometrical methods, which demand several hours per sample. The integrity of the AMS method is high and it might be convenient for regulatory supervision. (22 refs.)

  18. Determination of Ultralow Level 129I/127I in Natural Samples by Separation of Microgram Carrier Free Iodine and Accelerator Mass Spectrometry Detection

    DEFF Research Database (Denmark)

    Hou, Xiaolin; Zhou, Weijian; Chen, Ning

    2010-01-01

    of 129I/127I, and a detection limit of this method for 129I is calculated to be 105 atoms. This will allow us to accurately determine 129I in prenuclear geological samples of low iodine concentration with 129I/127I of 10−12, such as loess, soil, coral, rock, sediment, and groundwater. Some samples......Separation of carrier free iodine from low iodine level samples and accurate measurement of ultralow level 129I in micrograms of iodine target are essential but a bottleneck in geological dating of terrestrial system and tracer research using naturally produced 129I. In this work, we present...... a carrier free method using coprecipitation of AgI with AgCl for preparing micrograms of iodine target, associated with combustion using a tube furnace for separating iodine from solid samples and anion exchange chromatography for preconcentrating iodine from a large volume of water. An accelerator mass...

  19. Accurate determination of 129I, 41Ca and 10Be long-lived radionuclides concentrations in spent resins from the nuclear industry by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Nottoli-Lepage, E.

    2013-01-01

    Radiological characterization of nuclear waste is essential for the management of storage sites. More particularly, determining the concentration of Long-Lived Radionuclides (LLRN) is fundamental for their long term management. This study focuses on the determination of three LLRN concentrations, i.e. 129 I (T 1/2 = 15.7*10 6 a), 41 Ca (T 1/2 = 9.94*10 4 a) and 10 Be (T 1/2 = 1.387*10 6 a), in ion exchange resins used for primary fluid purification in Pressurized Water Reactors (PWR). To benefit from the Accelerator Mass Spectrometry (AMS) technique allowing to measure extremely low levels of nuclide concentrations, analytical procedures including: 1) sample dissolution; 2) selective and quantitative extraction of the analyte; and, 3) analyte conditioning for AMS measurements, were developed. Applied on spent resin samples collected at a 900 MW PWR, the procedures developed for each studied LLRN allowed their quantitative recovery and their selective extraction from β-γ emitters and isobars. The concentration measurements of the LLRN of interest were then performed on the Accelerator Mass Spectrometry national facility ASTER housed by the Centre Europeen de Recherche et d'Enseignement des Geosciences de l'Environnement (CEREGE, Aix-en-Provence). 129 I, 41 Ca and 10 Be concentrations in spent resins were measured to be about 10 ng/g, 20 pg/g and 4 ng/g of dry resin, respectively. Considering 129 I and 41 Ca, the measured concentrations agree with those assessed from scaling factors established relatively to easily measured gamma emitters ( 137 Cs and 60 Co). For 10 Be, the presented results are significantly different from expected values but are in agreement with previous ICP-MS results. (author) [fr

  20. Notes on Laser Acceleration

    International Nuclear Information System (INIS)

    Tajima, T.

    2008-01-01

    This note intends to motivate our effort toward the advent of new methods of particle acceleration, utilizing the fast rising laser technology. By illustrating the underlying principles in an intuitive manner and thus less jargon-clad fashion, we seek a direction in which we shall be able to properly control and harness the promise of laser acceleration. First we review the idea behind the laser wakefield. We then go on to examine ion acceleration by laser. We examine the sheath acceleration in particular and look for the future direction that allows orderly acceleration of ions in high energies

  1. Construction of cold mass assembly for full-length dipoles for the SSC [Superconducting Super Collider] accelerator

    International Nuclear Information System (INIS)

    Dahl, P.; Cottingham, J.; Garber, M.

    1986-10-01

    Four of the initial six 17m long demonstration dipole magnets for the proposed Superconducting Super Collider have been constructed, and the first one is now being tested. This paper describes the magnet design and construction of the cold mass assembly. The magnets are cold iron (and cold bore) 1-in-1 dipoles, wound with partially keystoned current density-graded high homogeneity NbTi cable in a two-layer cos θ coil of 40 mm inner diameter. The magnetic length is 16.6 m. The coil is prestressed by 15 mm wide stainless steel collars, and mounted in a circular, split iron yoke of 267 mm outer diameter, supported by a cylindrical yoke (and helium) containment vessel of stainless steel. The magnet bore tube assembly incorporates superconducting sextupole trim coils produced by an industrial, automatic process akin to printed circuit fabrication

  2. A comparative study of 129I content in environmental standard materials IAEA-375, NIST SRM 4354 and NIST SRM 4357 by Thermal Ionization Mass Spectrometry and Accelerator Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Olson, John; Adamic, Mary; Snyder, Darin; Brookhart, Jacob; Hahn, Paula; Watrous, Matthew

    2016-11-01

    Iodine environmental measurements have consistently been backed up in the literature by standard materials like IAEA-375, Chernobyl Soil. There are not many other sources of a certified reference material for 129I content for mass spectrometry measurements. Some that have been found in the literature include NIST-4354 and NIST-4357. They are still available at the time of this writing. They don’t have certified content or isotopic values. There has been some work in the literature to show that iodine is present, but there hasn’t been enough to establish a consensus value. These materials have been analyzed at INL through two separate mass spectrometry techniques. They involve a combustion method of the starting material in oxygen, followed by TIMS analysis and a leaching preparation analyzed by accelerator mass spectrometry. Combustion/TIMS preparation of NIST SRM-4354 resulted in a 129I/127I ratio of 1.92 x 10-6 which agrees with AMS measurements which measured the 129I/127I ratio to be 1.93 x 10-6.

  3. Instruments for radiation measurement in life sciences (4). VI. Use of Accelerator mass spectrometry in studies on drug metabolism and pharmacokinetics

    International Nuclear Information System (INIS)

    Ikeda, Toshihiko

    2005-01-01

    Non-clinical and clinical uses of accelerator mass spectrometry (AMS) are described mainly on studies of drug metabolism and pharmacokinetics from a view of new drug development. AMS is applicable as a highly sensitive method to measure plasma drug concentrations. Measurement of 14 C-labeled compounds less than 1 dpm/sample or of parathyroid hormone-related protein (PTHrP), in combination of AMS and radioimmunoassay without radioactive waste release is described as an example. Cases of measuring DNA-adduct are also described involving human studies using 14 C-mutagen (a quinoxaline derivative derived from burned amino acid, given in a microdose of 304 ng/kg, 4.3 μCi/body). Plasma concentration measurement, mass balance study and metabolite identification of 14 C-GI1817771 (a drug candidate) are a typical AMS application for a pharmacokinetic study in human in a microdose (121 Bq/body). Metabolites of 14 C-compound A in rat platelet are identified by the author. As above, AMS makes it possible to conduct the pharmacokinetic study in human at a microdose with no significant radiation exposure, which will promote the efficient new drug development. (N.I.)

  4. Evaluation of flow accelerated corrosion by coupled analysis of corrosion and flow dynamics (2), flow dynamics calculations for determining mixing factors and mass transfer coefficients

    International Nuclear Information System (INIS)

    Uehara, Yasushi; Uchida, Shunsuke; Naitoh, Masanori; Okada, Hidetoshi; Koshizuka, Seiichi

    2009-01-01

    In order to predict and mitigate flow accelerated corrosion (FAC) of carbon steel piping in PWR and BWR secondary systems, computer program packages for evaluating FAC have been developed by coupling one through three dimensional (1-3D) computational flow dynamics (CFD) models and corrosion models. To evaluate corrosive conditions, e.g., oxygen concentration and electrochemical corrosion potential (ECP) along the flow path, flow pattern and temperature in each elemental volume were obtained with 1D computational flow dynamics (CFD) codes. Precise flow turbulence and mass transfer coefficients at the structure surface were calculated with 3D CFD codes to determine wall thinning rates. One of the engineering options is application of k-ε calculation as a 3D CFD code, which has limitation of detail evaluation of flow distribution at very surface of large scale piping. A combination of k-ε calculation and wall function was proposed to evaluate precise distribution of mass transfer coefficients with reasonable CPU volume and computing time and, at the same time, reasonable accuracy. (author)

  5. Accelerating the three dimensions of E and P clockspeed - A novel strategy for optimizing utility in the Oil and Gas industry

    International Nuclear Information System (INIS)

    Weijermars, Ruud

    2009-01-01

    As the global Oil and Gas Industry enters its third, late lifecycle stage (outlined in the introduction of this study), new strategies and conceptual tools are needed to postpone - or reverse - the decline of the E and P industry. The problem is this: the late lifecycle is principally heralded by limited supply due to finite hydrocarbon reserves, while energy demand soars as world population and the global economy continue to grow. This study therefore proposes a framework through which an E and P company can critically assess its capability in accelerating lag-time between exploration and production. In the first part of this paper (Sections 1-3), the need for a phase-shift toward faster clockspeeds for the Oil and Gas industry is argued to be an important step to close the energy supply gap. In the second part of this paper (Sections 4-6), the strategy concept of clockspeed acceleration is further elaborated and optimization methods for the three principal dimensions of E and P clockspeed acceleration are discussed. The three Clockspeed Accelerators TM are: workflow speed, improvement rate of Uncertainty Mitigation and accrual speed of portfolio value. The third part of this paper (Sections 7-11) presents the empirical analysis of E and P clockspeed performance for two peer groups (IOC supermajors and public private partnership NOCs) comprising six companies each. The acceleration of E and P clockspeed can help to optimize production levels of conventional and unconventional oil, and includes diversification strategies that replace non-renewables with renewables. In summary, E and P Clockspeed Accelerators provide the gearshift instruments that enable the energy industry to better meet the required demand/supply ratios. The results of this study translate into the following deliverables for practical use by Oil and Gas professionals: -insight into the concept of clockspeed in E and P industry setting, -use of Clockspeed Accelerators TM as gearshift lever tools

  6. AixMICADAS, the accelerator mass spectrometer dedicated to 14C recently installed in Aix-en-Provence, France

    Science.gov (United States)

    Bard, Edouard; Tuna, Thibaut; Fagault, Yoann; Bonvalot, Lise; Wacker, Lukas; Fahrni, Simon; Synal, Hans-Arno

    2015-10-01

    A compact AMS system dedicated to measuring 14C in ultra-small samples was installed at the CEREGE in Aix-en-Provence at the end of March 2014, together with an automated graphitization system. AixMICADAS operates at around 200 kV with carbon ion stripping in helium leading to a transmission of about 47%. The hybrid ion source works with graphite targets and CO2 gas. It is coupled to a versatile gas interface system that ensures stable gas measurements from different sources: a cracker for CO2 in glass ampoules, an elemental analyzer for combusting organic matter and an automated system to handle carbonate by wet chemistry. The analyses performed during the first half-year of operation show that a precision of about 2‰ is reached on modern samples of about 1 mg of carbon. Measurements of IAEA reference materials of various 14C ages show a good agreement with consensus values. Direct measurements of geological graphites indicate a machine background equivalent to an age of 68,000 years BP. AixMICADAS is thus limited solely by the 14C contamination of samples in the field and in the laboratory. The performances of the gas ion source and its gas interface system were tested with two CO2 production units: the elemental analyzer and the automated carbonate hydrolysis unit. These tests show that samples ranging between 10 and 100 μg C can produce a 12C- ion beam of the order of 10-15 μA during time spans ranging from 3 to 30 min depending on the sample mass. Coupling the automated hydrolysis system to the gas ion source of AixMICADAS, enables us to develop a method involving sequential leaching of carbonate samples with direct 14C measurements of the leached fractions and the residual sample. The main advantage is that all of steps leaching and hydrolysis are performed in the same vial for a particular sample. A sequential leaching was applied to a young carbonate sample (ca. 6600 years BP) whose 14C age agrees with previous determination and which shows no sign of

  7. XCAMS: The compact "1"4C accelerator mass spectrometer extended for "1"0Be and "2"6Al at GNS Science, New Zealand

    International Nuclear Information System (INIS)

    Zondervan, A.; Hauser, T.M.; Kaiser, J.; Kitchen, R.L.; Turnbull, J.C.; West, J.G.

    2015-01-01

    Highlights: • We review the performance of a 0.5 MV AMS system for "1"0Be, "1"4C, and "2"6Al. • We identify the limiting factors to "1"0Be machine blank and detection efficiency. • We discuss an AMS data reduction method that accounts for non-Poisson uncertainty. - Abstract: A detailed description is given of the 0.5 MV tandem accelerator mass spectrometry (AMS) system for "1"0Be, "1"4C, "2"6Al, installed in early 2010 at GNS Science, New Zealand. Its design follows that of previously commissioned Compact "1"4C-only AMS (CAMS) systems based on the Pelletron tandem accelerator. The only basic departure from that design is an extension of the rare-isotope achromat with a 45° magnet and a two-anode gas-ionisation detector, to provide additional filtering for "1"0Be. Realised performance of the three AMS modes is discussed in terms of acceptance-test scores, "1"4C Poisson and non-Poisson errors, and "1"0Be detection limit and sensitivity. Operational details and hardware improvements, such as "1"0Be beam transport and particle detector setup, are highlighted. Statistics of repeat measurements of all graphitised "1"4C calibration cathodes since start-up show that 91% of their total uncertainty values are less than 0.3%, indicating that the rare-isotope beamline extension has not affected precision of "1"4C measurement. For "1"0Be, the limit of detection in terms of the isotopic abundance ratio "1"0Be/"9Be is 6 × 10"−"1"5 at at"−"1 and the total efficiency of counting atoms in the sample cathode is 1/8500 (0.012%).

  8. XCAMS: The compact {sup 14}C accelerator mass spectrometer extended for {sup 10}Be and {sup 26}Al at GNS Science, New Zealand

    Energy Technology Data Exchange (ETDEWEB)

    Zondervan, A., E-mail: a.zondervan@gns.cri.nz [GNS Science, Lower Hutt (New Zealand); Hauser, T.M. [National Electrostatics Corporation, Middleton, WI (United States); Kaiser, J. [GNS Science, Lower Hutt (New Zealand); Kitchen, R.L. [National Electrostatics Corporation, Middleton, WI (United States); Turnbull, J.C.; West, J.G. [GNS Science, Lower Hutt (New Zealand)

    2015-10-15

    Highlights: • We review the performance of a 0.5 MV AMS system for {sup 10}Be, {sup 14}C, and {sup 26}Al. • We identify the limiting factors to {sup 10}Be machine blank and detection efficiency. • We discuss an AMS data reduction method that accounts for non-Poisson uncertainty. - Abstract: A detailed description is given of the 0.5 MV tandem accelerator mass spectrometry (AMS) system for {sup 10}Be, {sup 14}C, {sup 26}Al, installed in early 2010 at GNS Science, New Zealand. Its design follows that of previously commissioned Compact {sup 14}C-only AMS (CAMS) systems based on the Pelletron tandem accelerator. The only basic departure from that design is an extension of the rare-isotope achromat with a 45° magnet and a two-anode gas-ionisation detector, to provide additional filtering for {sup 10}Be. Realised performance of the three AMS modes is discussed in terms of acceptance-test scores, {sup 14}C Poisson and non-Poisson errors, and {sup 10}Be detection limit and sensitivity. Operational details and hardware improvements, such as {sup 10}Be beam transport and particle detector setup, are highlighted. Statistics of repeat measurements of all graphitised {sup 14}C calibration cathodes since start-up show that 91% of their total uncertainty values are less than 0.3%, indicating that the rare-isotope beamline extension has not affected precision of {sup 14}C measurement. For {sup 10}Be, the limit of detection in terms of the isotopic abundance ratio {sup 10}Be/{sup 9}Be is 6 × 10{sup −15} at at{sup −1} and the total efficiency of counting atoms in the sample cathode is 1/8500 (0.012%).

  9. Calculation of Transactinide Homolog Isotope Production Reactions Possible with the Center for Accelerator Mass Spectrometry (CAMS) at Lawrence Livermore National Laboratory

    International Nuclear Information System (INIS)

    Moody, K.J.; Shaughnessy, D.A.; Gostic, J.M.

    2011-01-01

    The LLNL heavy element group has been investigating the chemical properties of the heaviest elements over the past several years. The properties of the transactinides (elements with Z > 103) are often unknown due to their low production rates and short half-lives, which require lengthy cyclotron irradiations in order to make enough atoms for statistically significant evaluations of their chemistry. In addition, automated chemical methods are often required to perform consistent and rapid chemical separations on the order of minutes for the duration of the experiment, which can last from weeks to months. Separation methods can include extraction chromatography, liquid-liquid extraction, or gas-phase chromatography. Before a lengthy transactinide experiment can be performed at an accelerator, a large amount of preparatory work must be done both to ensure the successful application of the chosen chemical system to the transactinide chemistry problem being addressed, and to evaluate the behavior of the lighter elemental homologs in the same chemical system. Since transactinide chemistry is literally performed on one single atom, its chemical properties cannot be determined from bulk chemical matrices, but instead must be inferred from the behavior of the lighter elements that occur in its chemical group and in those of its neighboring elements. By first studying the lighter group homologs in a particular chemical system, when the same system is applied to the transactinide element under investigation, its decay properties can be directly compared to those of the homologues, thereby allowing an inference of its own chemistry. The Center for Accelerator Mass Spectrometry (CAMS) at Lawrence Livermore National Laboratory (LLNL) includes a 1 MV Tandem accelerator, capable of accelerating light ions such as protons to energies of roughly 15 MeV. By using the CAMS beamline, tracers of transactinide homolog elements can be produced both for development of chemical systems and

  10. Calculation of Transactinide Homolog Isotope Production Reactions Possible with the Center for Accelerator Mass Spectrometry (CAMS) at Lawrence Livermore National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Moody, K J; Shaughnessy, D A; Gostic, J M

    2011-11-29

    The LLNL heavy element group has been investigating the chemical properties of the heaviest elements over the past several years. The properties of the transactinides (elements with Z > 103) are often unknown due to their low production rates and short half-lives, which require lengthy cyclotron irradiations in order to make enough atoms for statistically significant evaluations of their chemistry. In addition, automated chemical methods are often required to perform consistent and rapid chemical separations on the order of minutes for the duration of the experiment, which can last from weeks to months. Separation methods can include extraction chromatography, liquid-liquid extraction, or gas-phase chromatography. Before a lengthy transactinide experiment can be performed at an accelerator, a large amount of preparatory work must be done both to ensure the successful application of the chosen chemical system to the transactinide chemistry problem being addressed, and to evaluate the behavior of the lighter elemental homologs in the same chemical system. Since transactinide chemistry is literally performed on one single atom, its chemical properties cannot be determined from bulk chemical matrices, but instead must be inferred from the behavior of the lighter elements that occur in its chemical group and in those of its neighboring elements. By first studying the lighter group homologs in a particular chemical system, when the same system is applied to the transactinide element under investigation, its decay properties can be directly compared to those of the homologues, thereby allowing an inference of its own chemistry. The Center for Accelerator Mass Spectrometry (CAMS) at Lawrence Livermore National Laboratory (LLNL) includes a 1 MV Tandem accelerator, capable of accelerating light ions such as protons to energies of roughly 15 MeV. By using the CAMS beamline, tracers of transactinide homolog elements can be produced both for development of chemical systems and

  11. Measurements of local mass transfer coefficient of Flow Accelerated Corrosion at feeder outlet pipes in CANDU using Plaster of Paris method

    International Nuclear Information System (INIS)

    Hyuk Kwon; Dong Un Seo; Goon-Cherl Park

    2005-01-01

    Full text of publication follows: Flow Accelerated Corrosion (FAC) is a corrosion mechanism that results in wall thinning in piping systems and components. FAC on carbon steels in pure water has occurred in a number of industry and power plant. A pipe wall thinning due to the FAC at nuclear power plant is just reported in confined to carbon steel pipe on the secondary system which does not equip a radioactive component. Recently, at Canadian Deuterium Uranium type reactor, it is reported that the feeder lines suffer the wall thinning on the primary system to equip 380 feeder pipes. Differently from the fast FAC rate of the secondary system on PWR, FAC rate of feeder pipes on CANDU is not more than the 0.2 mm/year. Although the FAC rate of feeder pipe is relatively slow, the narrow thickness margin of 2.6089 mm is endangered sufficiently by only the slow FAC rate. The FAC is governed by the mass transfer coefficient which is determined by the flow field. To well predict the FAC rate, mass transfer coefficient should be well measured or calculated. New measurement method of mass transfer coefficient is developed to obtain the coefficient for the complex shape like feeder pipe. The method evaluated the naphthalene sublimation method to apply it under the water flow. The naphthalene sublimation method can be used to study mass and heat transfer with confidence for a variety of applications, but with certain restrictions. At present, Plaster of paris method can modified the sublimation method to overcome the restrictions. This method is particularly useful in complex flows on geometries and for flows with large gradients in wall transport rate. The test specimen can be easily prepared by several methods, including dipping, machining, spraying, and casting. The local transfer coefficients can be determined with high accuracy and in detail by automated measurement systems that eliminate most human errors during the measurement process. To evaluate the method, the

  12. Impact of mass media on the utilization of antenatal care services among women of rural community in Nepal.

    Science.gov (United States)

    Acharya, Dilaram; Khanal, Vishnu; Singh, Jitendra Kumar; Adhikari, Mandira; Gautam, Salila

    2015-08-12

    Antenatal care has several benefits for expecting mothers and birth outcomes; yet many mothers do not utilise this service in Nepal. Mass media may play an important role in increasing the use of antenatal care and other maternal health services. However, the effect of mass media on increasing health service utilisation has remained an under studied area in Nepal. The aim of this study was to investigate the impact of mass media on the utilisation of antenatal care services in rural Nepal. A community-based cross-sectional study was conducted in Sinurjoda Village Development Committee of Dhanusha District, Nepal. A total of 205 mothers of children aged under 1 year were selected using systematic random sampling. Logistic regression was employed to examine the association between selected antenatal care services and mass media exposure after adjusting for other independent variables. A majority of mothers were exposed to mass media. Radio was accessible to most (60.0%) of the participants followed by television (43.41%). Mothers exposed to mass media were more likely to attending antenatal visits [Odds ratio (OR) 6.28; 95% CI (1.01-38.99)], taking rest and sleep during pregnancy [OR 2.65; 95% CI (1.13-6.26)], and receiving TT immunization [OR 5.12; 95% CI (1.23-21.24)] than their non-exposed counterparts. The study reported a positive influence of mass media on the utilisation of antenatal care services in Nepal. Therefore, further emphasis should be given to increase awareness of women of rural Nepal through mass media to improve utilisation of antenatal care services in Nepal.

  13. Can Accelerators Accelerate Learning?

    International Nuclear Information System (INIS)

    Santos, A. C. F.; Fonseca, P.; Coelho, L. F. S.

    2009-01-01

    The 'Young Talented' education program developed by the Brazilian State Funding Agency (FAPERJ)[1] makes it possible for high-schools students from public high schools to perform activities in scientific laboratories. In the Atomic and Molecular Physics Laboratory at Federal University of Rio de Janeiro (UFRJ), the students are confronted with modern research tools like the 1.7 MV ion accelerator. Being a user-friendly machine, the accelerator is easily manageable by the students, who can perform simple hands-on activities, stimulating interest in physics, and getting the students close to modern laboratory techniques.

  14. Can Accelerators Accelerate Learning?

    Science.gov (United States)

    Santos, A. C. F.; Fonseca, P.; Coelho, L. F. S.

    2009-03-01

    The 'Young Talented' education program developed by the Brazilian State Funding Agency (FAPERJ) [1] makes it possible for high-schools students from public high schools to perform activities in scientific laboratories. In the Atomic and Molecular Physics Laboratory at Federal University of Rio de Janeiro (UFRJ), the students are confronted with modern research tools like the 1.7 MV ion accelerator. Being a user-friendly machine, the accelerator is easily manageable by the students, who can perform simple hands-on activities, stimulating interest in physics, and getting the students close to modern laboratory techniques.

  15. An effective method of UV-oxidation of dissolved organic carbon in natural waters for radiocarbon analysis by accelerator mass spectrometry

    Science.gov (United States)

    Xue, Yuejun; Ge, Tiantian; Wang, Xuchen

    2015-12-01

    Radiocarbon (14C) measurement of dissolved organic carbon (DOC) is a very powerful tool to study the sources, transformation and cycling of carbon in the ocean. The technique, however, remains great challenges for complete and successful oxidation of sufficient DOC with low blanks for high precision carbon isotopic ratio analysis, largely due to the overwhelming proportion of salts and low DOC concentrations in the ocean. In this paper, we report an effective UV-Oxidation method for oxidizing DOC in natural waters for radiocarbon analysis by accelerator mass spectrometry (AMS). The UV-oxidation system and method show 95%±4% oxidation efficiency and high reproducibility for DOC in both river and seawater samples. The blanks associated with the method was also low (about 3 µg C) that is critical for 14C analysis. As a great advantage of the method, multiple water samples can be oxidized at the same time so it reduces the sample processing time substantially compared with other UV-oxidation method currently being used in other laboratories. We have used the system and method for 14C studies of DOC in rivers, estuaries, and oceanic environments and have received promise results.

  16. Accelerator mass spectrometry analysis of 14C-oxaliplatin concentrations in biological samples and 14C contents in biological samples and antineoplastic agents

    Science.gov (United States)

    Toyoguchi, Teiko; Kobayashi, Takeshi; Konno, Noboru; Shiraishi, Tadashi; Kato, Kazuhiro; Tokanai, Fuyuki

    2015-10-01

    Accelerator mass spectrometry (AMS) is expected to play an important role in microdose trials. In this study, we measured the 14C concentration in 14C-oxaliplatin-spiked serum, urine and supernatant of fecal homogenate samples in our Yamagata University (YU) - AMS system. The calibration curves of 14C concentration in serum, urine and supernatant of fecal homogenate were linear (the correlation coefficients were ⩾0.9893), and the precision and accuracy was within the acceptance criteria. To examine a 14C content of water in three vacuum blood collection tubes and a syringe were measured. 14C was not detected from water in these devices. The mean 14C content in urine samples of 6 healthy Japanese volunteers was 0.144 dpm/mL, and the intra-day fluctuation of 14C content in urine from a volunteer was little. The antineoplastic agents are administered to the patients in combination. Then, 14C contents of the antineoplastic agents were quantitated. 14C contents were different among 10 antineoplastic agents; 14C contents of paclitaxel injection and docetaxel hydrate injection were higher than those of the other injections. These results indicate that our quantitation method using YU-AMS system is suited for microdosing studies and that measurement of baseline and co-administered drugs might be necessary for the studies in low concentrations.

  17. Accelerator mass spectrometry analysis of "1"4C-oxaliplatin concentrations in biological samples and "1"4C contents in biological samples and antineoplastic agents

    International Nuclear Information System (INIS)

    Toyoguchi, Teiko; Kobayashi, Takeshi; Konno, Noboru; Shiraishi, Tadashi; Kato, Kazuhiro; Tokanai, Fuyuki

    2015-01-01

    Accelerator mass spectrometry (AMS) is expected to play an important role in microdose trials. In this study, we measured the "1"4C concentration in "1"4C-oxaliplatin-spiked serum, urine and supernatant of fecal homogenate samples in our Yamagata University (YU) – AMS system. The calibration curves of "1"4C concentration in serum, urine and supernatant of fecal homogenate were linear (the correlation coefficients were ⩾0.9893), and the precision and accuracy was within the acceptance criteria. To examine a "1"4C content of water in three vacuum blood collection tubes and a syringe were measured. "1"4C was not detected from water in these devices. The mean "1"4C content in urine samples of 6 healthy Japanese volunteers was 0.144 dpm/mL, and the intra-day fluctuation of "1"4C content in urine from a volunteer was little. The antineoplastic agents are administered to the patients in combination. Then, "1"4C contents of the antineoplastic agents were quantitated. "1"4C contents were different among 10 antineoplastic agents; "1"4C contents of paclitaxel injection and docetaxel hydrate injection were higher than those of the other injections. These results indicate that our quantitation method using YU-AMS system is suited for microdosing studies and that measurement of baseline and co-administered drugs might be necessary for the studies in low concentrations.

  18. Accelerator mass spectrometry analysis of {sup 14}C-oxaliplatin concentrations in biological samples and {sup 14}C contents in biological samples and antineoplastic agents

    Energy Technology Data Exchange (ETDEWEB)

    Toyoguchi, Teiko, E-mail: tteiko@med.id.yamagata-u.ac.jp [Department of Pharmacy, Yamagata University Hospital, 2-2-2 Iida-Nishi, Yamagata-shi, Yamagata 990-9585 (Japan); Kobayashi, Takeshi; Konno, Noboru; Shiraishi, Tadashi [Department of Pharmacy, Yamagata University Hospital, 2-2-2 Iida-Nishi, Yamagata-shi, Yamagata 990-9585 (Japan); Kato, Kazuhiro; Tokanai, Fuyuki [Department of Physics, Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata-shi, Yamagata 990-8560 (Japan)

    2015-10-15

    Accelerator mass spectrometry (AMS) is expected to play an important role in microdose trials. In this study, we measured the {sup 14}C concentration in {sup 14}C-oxaliplatin-spiked serum, urine and supernatant of fecal homogenate samples in our Yamagata University (YU) – AMS system. The calibration curves of {sup 14}C concentration in serum, urine and supernatant of fecal homogenate were linear (the correlation coefficients were ⩾0.9893), and the precision and accuracy was within the acceptance criteria. To examine a {sup 14}C content of water in three vacuum blood collection tubes and a syringe were measured. {sup 14}C was not detected from water in these devices. The mean {sup 14}C content in urine samples of 6 healthy Japanese volunteers was 0.144 dpm/mL, and the intra-day fluctuation of {sup 14}C content in urine from a volunteer was little. The antineoplastic agents are administered to the patients in combination. Then, {sup 14}C contents of the antineoplastic agents were quantitated. {sup 14}C contents were different among 10 antineoplastic agents; {sup 14}C contents of paclitaxel injection and docetaxel hydrate injection were higher than those of the other injections. These results indicate that our quantitation method using YU-AMS system is suited for microdosing studies and that measurement of baseline and co-administered drugs might be necessary for the studies in low concentrations.

  19. Early Upper Paleolithic chronology in the Levant: new ABOx-SC accelerator mass spectrometry results from the Mughr el-Hamamah Site, Jordan.

    Science.gov (United States)

    Stutz, Aaron Jonas; Shea, John J; Rech, Jason A; Pigati, Jeffrey S; Wilson, Jim; Belmaker, Miriam; Albert, Rosa Maria; Arpin, Trina; Cabanes, Dan; Clark, Jamie L; Hartman, Gideon; Hourani, Fuad; White, Chantel E; Nilsson Stutz, Liv

    2015-08-01

    Methodological developments and new paleoanthropological data remain jointly central to clarifying the timing and systemic interrelationships between the Middle-Upper Paleolithic (MP-UP) archaeological transition and the broadly contemporaneous anatomically modern human-archaic biological turnover. In the recently discovered cave site of Mughr el-Hamamah, Jordan, in situ flint artifacts comprise a diagnostic early Upper Paleolithic (EUP) assemblage. Unusually well-preserved charcoal from hearths and other anthropogenic features associated with the lithic material were subjected to acid-base-wet oxidation-stepped combustion (ABOx-SC) pretreatment. This article presents the ABOx-SC accelerator mass spectrometry (AMS) radiocarbon dates on nine charcoal specimens from a single palimpsest occupation layer. Date calibration was carried out using the INTCAL13 radiocarbon calibration dataset. With the bulk of the material dating to 45-39 ka cal BP (thousands of years calibrated before present), the Mughr el-Hamamah lithic artifacts reveal important differences from penecontemporaneous sites in the region, documenting greater technological variability than previously known for this time frame in the Levant. The radiocarbon data from this EUP archaeological context highlight remaining challenges for increasing chronological precision in documenting the MP-UP transition. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Hydrologic and geochemical controls on the transport of radionuclides in natural undisturbed arid environments as determined by accelerator mass spectrometry measurements. 1997 annual progress report

    International Nuclear Information System (INIS)

    Caffee, M.W.; Finkel, R.C.; McAninch, J.E.; Nimz, G.J.

    1997-01-01

    'During FY97 this study has developed unique accelerator mass spectrometry (AMS) analytical techniques for measurement of 99 Tc and 129 I, which compliments an improved capability for measurement of 36 Cl. The ability to measure these nuclides in natural soil samples has been demonstrated through analytical results obtained during FY97. Methods to determine the distribution of these nuclides in their natural setting, which will vary depending on site-specific chemical conditions, have also been developed. Spatially well-characterized soil samples have been collected from the vadose zone to a depth of -5 meters at the Nevada Test Site. To do this, a deep trench has been excavated and the geological setting for the soils has been well documented. Physical, chemical, and isotopic analysis of these soil samples during the course of this research project will result in a numerical computer model for moisture and radionuclide migration in arid soils that is valuable to nuclear waste storage, site remediation, and groundwater recharge concerns.'

  1. Hints of supernova debris deposition on the lunar surface: {sup 60}Fe and {sup 53}Mn measurements by means of accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Fimiani, Leticia; Faestermann, Thomas; Gomez Guzman, Jose Manuel; Hain, Karin; Korschinek, Gunther; Ludwig, Peter [Physik Department, Technische Universitaet Muenchen, Garching (Germany); Herzog, Gregory; Ligon, Bret; Park, Jisun [Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, NJ (United States); Rugel, Georg [Forschungszentrum Dresden Rossendorf, Dresden (Germany)

    2013-07-01

    The enhanced concentration of {sup 60}Fe in a deep ocean ferro-manganese crust about (2.1±0.4) Myr old (Fitoussi et al., PRL 101, 121101 (2008)), suggests that one or more supernova (SN) explosions occurred in the vicinity of the Solar System. That observation was only possible with the ultra sensitive Accelerator Mass Spectrometry (AMS) technique at the Maier-Leibnitz-Laboratorium in Munich, where we are able to measure concentrations of {sup 60}Fe/Fe down to a level of 10{sup -16}. Because of its lacking atmosphere and negligible sedimentation rate, the Lunar surface is an excellent quantitative reservoir for SN debris. We searched for live {sup 60}Fe and {sup 53}Mn in samples from 3 Apollo missions. {sup 53}Mn is, similar as {sup 26}Al and {sup 60}Fe, a tool to trace nucleosynthesis activities. It is formed primarily during the explosive silicon-burning of the inner shells of SNe via {sup 53}Fe which β-decays to {sup 53}Mn with an 8.51 min half-life. Samples where we found an enhanced {sup 60}Fe concentration showed also an enhancement of {sup 53}Mn. If confirmed, this could be the first detection of live {sup 53}Mn originating from nucleosynthesis.

  2. Light-induced alterations of pineapple (Ananas comosus [L.] Merr.) juice volatiles during accelerated ageing and mass spectrometric studies into their precursors.

    Science.gov (United States)

    Steingass, Christof Björn; Glock, Mona Pia; Lieb, Veronika Maria; Carle, Reinhold

    2017-10-01

    Alterations of volatiles during accelerated light-induced ageing of pineapple juice were assessed by HS-SPME-GC-MS in a non-targeted profiling analysis over a 16-week period. Multivariate statistics permitted to reveal substantial chemical markers generally describing the effect of light storage. Volatiles generated comprised phenylpropenes, carbonyls, 2-methylthiophene, toluene, and furfural, while concentrations of methyl and ethyl esters, terpenes, and furanones decreased. In addition, the qualitative composition of phenolic compounds and glycoside-bound volatiles in selected samples was characterized by HPLC-DAD-ESI-MS n as well as HR-ESI-MS. The fresh juice contained unique pineapple metabolites such as S-p-coumaryl, S-coniferyl, S-sinapylglutathione, and structurally related derivatives. Among others, the presence of p-coumaroyl, feruloyl, and caffeoylisocitrate as well as three 4-hydroxy-2,5-dimethyl-3(2H)-furanone glycosides in pineapples could be substantiated by the HR-ESI-MS experiment. Mass spectrometric assignments of selected metabolites are presented, and putative linkages between volatiles and their precursors are established. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Speciation analysis of 129I in seawater by carrier-free AgI-AgCl coprecipitation and accelerator mass spectrometric measurement

    DEFF Research Database (Denmark)

    Luo, Maoyi; Hou, Xiaolin; He, Chaohui

    2013-01-01

    A rapid and simple method was developed for speciation analysis of 129I in seawater by selective coprecipitation of carrier-free iodide and accelerator mass spectrometry (AMS) measurement of 129I. Iodide was separated from seawater and other species of iodine by coprecipitation of AgI with Ag2SO3......, AgCl, and AgBr by addition of only 100 mg/L Ag+ and 0.3 mmol/L NaHSO3 at pH 4.2-5.5. The separation efficiency of iodide was more than 95%, and crossover between 129IO3- and 129I- fractions is less than 3%. Iodate and total inorganic iodine were converted to iodide by use of NaHSO3 at pH 1......-2 and then separated by the same method as for iodide. Ag2SO3 in the coprecipitate was removed by washing with 3 mol/L HNO3 and the excess AgCl and AgBr was removed by use of diluted NH3, and finally a 1-3 mg precipitate was obtained for AMS measurement of 129I. The recovery of iodine species in the entire procedure...

  4. Applying the accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Barbalat, Oscar

    1989-12-15

    Originally developed as tools for frontier physics, particle accelerators provide valuable spinoff benefits in applied research and technology. These accelerator applications are the subject of a biennial meeting in Denton, Texas, but the increasing activity in this field resulted this year (5-9 September) in the first European Conference on Accelerators in Applied Research and Technology, organized by K. Bethge of Frankfurt's Goethe University. The meeting reflected a wide range of applications - ion beam analysis, exploitation of nuclear microbeams, accelerator mass spectrometry, applications of photonuclear reactions, ion beam processing, synchrotron radiation for semiconductor technology, specialized technology.

  5. Applying the accelerator

    International Nuclear Information System (INIS)

    Barbalat, Oscar

    1989-01-01

    Originally developed as tools for frontier physics, particle accelerators provide valuable spinoff benefits in applied research and technology. These accelerator applications are the subject of a biennial meeting in Denton, Texas, but the increasing activity in this field resulted this year (5-9 September) in the first European Conference on Accelerators in Applied Research and Technology, organized by K. Bethge of Frankfurt's Goethe University. The meeting reflected a wide range of applications - ion beam analysis, exploitation of nuclear microbeams, accelerator mass spectrometry, applications of photonuclear reactions, ion beam processing, synchrotron radiation for semiconductor technology, specialized technology

  6. Plasma accelerators

    International Nuclear Information System (INIS)

    Bingham, R.; Angelis, U. de; Johnston, T.W.

    1991-01-01

    Recently attention has focused on charged particle acceleration in a plasma by a fast, large amplitude, longitudinal electron plasma wave. The plasma beat wave and plasma wakefield accelerators are two efficient ways of producing ultra-high accelerating gradients. Starting with the plasma beat wave accelerator (PBWA) and laser wakefield accelerator (LWFA) schemes and the plasma wakefield accelerator (PWFA) steady progress has been made in theory, simulations and experiments. Computations are presented for the study of LWFA. (author)

  7. Linear Accelerators

    International Nuclear Information System (INIS)

    Vretenar, M

    2014-01-01

    The main features of radio-frequency linear accelerators are introduced, reviewing the different types of accelerating structures and presenting the main characteristics aspects of linac beam dynamics

  8. Utilizing thermal building mass for storage in district heating systems: Combined building level simulations and system level optimization

    DEFF Research Database (Denmark)

    Dominkovic, D. F.; Gianniou, P.; Münster, M.

    2018-01-01

    on the energy supply of district heating. Results showed that longer preheating time increased the possible duration of cut-off events. System optimization showed that the thermal mass for storage was used as intra-day storage. Flexible load accounted for 5.5%–7.7% of the total district heating demand...

  9. Hepatoblastoma Biology Using Isotope Ratio Mass Spectrometry: Utility of a Unique Technique for the Analysis of Oncological Specimens.

    Science.gov (United States)

    Taran, Katarzyna; Frączek, Tomasz; Sitkiewicz, Anna; Sikora-Szubert, Anita; Kobos, Józef; Paneth, Piotr

    2016-07-07

    Hepatoblastoma is the most common primary liver tumor in children. However, it occurs rarely, with an incidence of 0.5-1.5 cases per million children. There is no clear explanation of the relationship between clinicopathologic features, therapy, and outcome in hepatoblastoma cases, so far. One of the most widely accepted prognostic factors in hepatoblastoma is histology of the tumor. The aim of the study was to determine the potential differences in biology of hepatoblastoma histological subtypes at the atomic level using the unique method of isotope ratio mass spectrometry, which is especially valuable in examination of small groups of biological samples. Twenty-four measurements of nitrogen stable isotope ratio, carbon stable isotope ratio and total carbon to nitrogen mass ratio in fetal and embryonal hepatoblastoma tissue were performed using a Sercon 20-22 Continuous Flow Isotope Ratio Mass Spectrometer (CF-IRMS) coupled with a Sercon SL elemental analyzer for simultaneous carbon-nitrogen-sulfur (NCS) analysis. A difference of about 1.781‰ in stable nitrogen isotope 15N/14N ratio was found between examined hepatoblastoma histological subtypes. The prognosis in liver tumors cases in children may be challenging particularly because of the lack of versatile methods of its evaluation. Isotope ratio mass spectrometry allows one to determine the difference between hepatoblastoma histological subtypes and clearly indicates the cases with the best outcome.

  10. Hepatoblastoma Biology Using Isotope Ratio Mass Spectrometry: Utility of a Unique Technique for the Analysis of Oncological Specimens

    Directory of Open Access Journals (Sweden)

    Katarzyna Taran

    2016-07-01

    Full Text Available Introduction: Hepatoblastoma is the most common primary liver tumor in children. However, it occurs rarely, with an incidence of 0.5-1.5 cases per million children. There is no clear explanation of the relationship between clinicopathologic features, therapy, and outcome in hepatoblastoma cases, so far. One of the most widely accepted prognostic factors in hepatoblastoma is histology of the tumor. The aim of the study was to determine the potential differences in biology of hepatoblastoma histological subtypes at the atomic level using the unique method of isotope ratio mass spectrometry, which is especially valuable in examination of small groups of biological samples.Material/Methods: Twenty-four measurements of nitrogen stable isotope ratio, carbon stable isotope ratio and total carbon to nitrogen mass ratio in fetal and embryonal hepatoblastoma tissue were performed using a Sercon 20-22 Continuous Flow Isotope Ratio Mass Spectrometer (CF-IRMS coupled with a Sercon SL elemental analyzer for simultaneous carbon-nitrogen-sulfur (NCS analysis.Results: A difference of about 1.781‰ in stable nitrogen isotope 15N/14N ratio was found between examined hepatoblastoma histological subtypes.Conclusions: The prognosis in liver tumors cases in children may be challenging particularly because of the lack of versatile methods of its evaluation. Isotope ratio mass spectrometry allows one to determine the difference between hepatoblastoma histological subtypes and clearly indicates the cases with the best outcome.

  11. Effect of particulate aggregation in aquatic environments on the beam attenuation and its utility as a proxy for particulate mass.

    Science.gov (United States)

    Boss, Emmanuel; Slade, Wayne; Hill, Paul

    2009-05-25

    Marine aggregates, agglomerations of particles and dissolved materials, are an important particulate pool in aquatic environments, but their optical properties are not well understood. To improve understanding of the optical properties of aggregates, two related studies are presented. In the first, an in situ manipulation experiment is described, in which beam attenuation of undisturbed and sheared suspensions are compared. Results show that in the sheared treatment bulk particle size decreases and beam attenuation increases, consistent with the hypothesis that a significant fraction of mass in suspension is contained in fragile aggregates. Interestingly, the magnitude of increase in beam attenuation is less than expected if the aggregates are modeled as solid spheres. Motivated by this result, a second study is presented, in which marine aggregates are modeled to assess how the beam attenuation of aggregates differs from that of their constituent particles and from solid particles of the same mass. The model used is based on that of Latimer [Appl. Opt. 24, 3231 (1985)] and mass specific attenuation is compared with that based on homogeneous and solid particles, the standard model for aquatic particles. In the modeling we use recent research relating size and solid fraction of aquatic aggregates. In contrast with Mie theory, this model provides a rather size-insensitive mass specific attenuation for most relevant sizes. This insensitivity is consistent with the observations that mass specific beam-attenuation of marine particles is in the range 0.2-0.6m(2)/gr despite large variability in size distribution and composition across varied aquatic environments.

  12. Microelectromechanical acceleration-sensing apparatus

    Science.gov (United States)

    Lee, Robb M [Albuquerque, NM; Shul, Randy J [Albuquerque, NM; Polosky, Marc A [Albuquerque, NM; Hoke, Darren A [Albuquerque, NM; Vernon, George E [Rio Rancho, NM

    2006-12-12

    An acceleration-sensing apparatus is disclosed which includes a moveable shuttle (i.e. a suspended mass) and a latch for capturing and holding the shuttle when an acceleration event is sensed above a predetermined threshold level. The acceleration-sensing apparatus provides a switch closure upon sensing the acceleration event and remains latched in place thereafter. Examples of the acceleration-sensing apparatus are provided which are responsive to an acceleration component in a single direction (i.e. a single-sided device) or to two oppositely-directed acceleration components (i.e. a dual-sided device). A two-stage acceleration-sensing apparatus is also disclosed which can sense two acceleration events separated in time. The acceleration-sensing apparatus of the present invention has applications, for example, in an automotive airbag deployment system.

  13. Influenza outbreak during Sydney World Youth Day 2008: the utility of laboratory testing and case definitions on mass gathering outbreak containment.

    Directory of Open Access Journals (Sweden)

    Sebastiaan J van Hal

    Full Text Available BACKGROUND: Influenza causes annual epidemics and often results in extensive outbreaks in closed communities. To minimize transmission, a range of interventions have been suggested. For these to be effective, an accurate and timely diagnosis of influenza is required. This is confirmed by a positive laboratory test result in an individual whose symptoms are consistent with a predefined clinical case definition. However, the utility of these clinical case definitions and laboratory testing in mass gathering outbreaks remains unknown. METHODS AND RESULTS: An influenza outbreak was identified during World Youth Day 2008 in Sydney. From the data collected on pilgrims presenting to a single clinic, a Markov model was developed and validated against the actual epidemic curve. Simulations were performed to examine the utility of different clinical case definitions and laboratory testing strategies for containment of influenza outbreaks. Clinical case definitions were found to have the greatest impact on averting further cases with no added benefit when combined with any laboratory test. Although nucleic acid testing (NAT demonstrated higher utility than indirect immunofluorescence antigen or on-site point-of-care testing, this effect was lost when laboratory NAT turnaround times was included. The main benefit of laboratory confirmation was limited to identification of true influenza cases amenable to interventions such as antiviral therapy. CONCLUSIONS: Continuous re-evaluation of case definitions and laboratory testing strategies are essential for effective management of influenza outbreaks during mass gatherings.

  14. Determination of four major saponins in the seeds of Aesculus chinensis Bunge using accelerated solvent extraction followed by high-performance liquid chromatography and electrospray-time of flight mass spectrometry.

    Science.gov (United States)

    Chen, Junhui; Li, Wenlong; Yang, Baijuan; Guo, Xiuchun; Lee, Frank Sen-Chun; Wang, Xiaoru

    2007-07-23

    A new method based on accelerated solvent extraction (ASE) followed by a reliable high-performance liquid chromatography-diode array detector (HPLC-DAD) and positive ion electrospray-time of flight mass spectrometry (ESI-TOF/MS) analysis has been developed for the characterization and quantification of four major saponins in extracts of the seeds of Aesculus chinensis Bunge (semen aesculi). The saponins escin Ia, escin Ib, isoescin Ia and isoescin Ib were extracted from seeds of A. chinesis Bunge via ASE, and the operational parameters of ASE were optimized, such as extraction solvent, extraction temperature, static extraction time and extraction cycles. The optimized procedure employed 70% MeOH as extraction solvent, 120 degrees C of extraction temperature, 7 min of static extraction time, 60% flush volume and the extraction recoveries of the four compounds were nearly to 100% for two cycles. The HPLC conditions are as follows: SinoChrom ODS BP C18 (4.6 mm x 200 mm, 5 microm) column, acetonitrile and 0.10% phosphoric acid solution as mobile phase, flow rate is 1.0 mL min(-1), detection length of UV is 203 nm, injection volume is 10 microL. The results indicated that the developed HPLC method is simple, sensitive and reliable for the determination of four major saponins in seeds of A. chinesis Bunge with a good linearity (r2 > 0.9994), precision (relative standard deviation (R.S.D.) < 1.5%) and the recovery ranges of 95.2-97.3%. The limits of detection (LOD) of the four compounds were in the range of 0.40-0.75 microg mL(-1). This assay can be readily utilized as a quality control method for semen aesculi and other related medicinal plants.

  15. Distinguishing benign from malignant pelvic mass utilizing an algorithm with HE4, menopausal status, and ultrasound findings

    Science.gov (United States)

    Chan, Karen KL; Chen, Chi-An; Nam, Joo-Hyun; Ochiai, Kazunori; Aw, Tar-Choon; Sabaratnam, Subathra; Hebbar, Sudarshan; Sickan, Jaganathan; Schodin, Beth A; Charakorn, Chuenkamon; Sumpaico, Walfrido W

    2015-01-01

    Objective The purpose of this study was to develop a risk prediction score for distinguishing benign ovarian mass from malignant tumors using CA-125, human epididymis protein 4 (HE4), ultrasound findings, and menopausal status. The risk prediction score was compared to the risk of malignancy index and risk of ovarian malignancy algorithm (ROMA). Methods This was a prospective, multicenter (n=6) study with patients from six Asian countries. Patients had a pelvic mass upon imaging and were scheduled to undergo surgery. Serum CA-125 and HE4 were measured on preoperative samples, and ultrasound findings were recorded. Regression analysis was performed and a risk prediction model was developed based on the significant factors. A bootstrap technique was applied to assess the validity of the HE4 model. Results A total of 414 women with a pelvic mass were enrolled in the study, of which 328 had documented ultrasound findings. The risk prediction model that contained HE4, menopausal status, and ultrasound findings exhibited the best performance compared to models with CA-125 alone, or a combination of CA-125 and HE4. This model classified 77.2% of women with ovarian cancer as medium or high risk, and 86% of women with benign disease as very-low, low, or medium-low risk. This model exhibited better sensitivity than ROMA, but ROMA exhibited better specificity. Both models performed better than CA-125 alone. Conclusion Combining ultrasound with HE4 can improve the sensitivity for detecting ovarian cancer compared to other algorithms. PMID:25310857

  16. Complete Analysis of a Biologically Active Tetrapeptide: A Project Utilizing Thin-Layer Chromatography and Tandem Quadrupole Mass Spectrometry

    Science.gov (United States)

    Lefevre, Joseph W.; Dodsworth, David W.

    2000-04-01

    The biologically active tetrapeptide d-Ala-Gly-l-Phe-d-Leu ([des-Tyr1-d-Ala2-d-Leu5]enkephalin) was analyzed for its amino acid content and stereochemistry by normal and reversed-phase thin-layer chromatography (TLC), and its sequence was determined by tandem quadrupole mass spectrometry. The project involved sequential N-dansylation of a portion of the tetrapeptide, hydrolysis, isolation, and identification of the N-terminal amino acid as dansyl-alanine by comparison with standards using normal-phase TLC. A second portion of the tetrapeptide was hydrolyzed and the resulting four free amino acids were converted to their corresponding dansyl derivatives and purified by preparative normal-phase TLC. The three dansyl amino acids not identified previously were identified by TLC. The stereochemistry of each was determined by comparison with dansyl-dl-amino acid standards using reversed-phase TLC in the presence of ß-cyclodextrin, a chiral mobile phase additive. Finally, the correct amino acid sequence was determined by tandem quadrupole mass spectrometry. This project gives students valuable experience in microscale synthesis, both normal and reversed-phase TLC, stereochemical analysis, and mass spectrometry.

  17. Binomial probability distribution model-based protein identification algorithm for tandem mass spectrometry utilizing peak intensity information.

    Science.gov (United States)

    Xiao, Chuan-Le; Chen, Xiao-Zhou; Du, Yang-Li; Sun, Xuesong; Zhang, Gong; He, Qing-Yu

    2013-01-04

    Mass spectrometry has become one of the most important technologies in proteomic analysis. Tandem mass spectrometry (LC-MS/MS) is a major tool for the analysis of peptide mixtures from protein samples. The key step of MS data processing is the identification of peptides from experimental spectra by searching public sequence databases. Although a number of algorithms to identify peptides from MS/MS data have been already proposed, e.g. Sequest, OMSSA, X!Tandem, Mascot, etc., they are mainly based on statistical models considering only peak-matches between experimental and theoretical spectra, but not peak intensity information. Moreover, different algorithms gave different results from the same MS data, implying their probable incompleteness and questionable reproducibility. We developed a novel peptide identification algorithm, ProVerB, based on a binomial probability distribution model of protein tandem mass spectrometry combined with a new scoring function, making full use of peak intensity information and, thus, enhancing the ability of identification. Compared with Mascot, Sequest, and SQID, ProVerB identified significantly more peptides from LC-MS/MS data sets than the current algorithms at 1% False Discovery Rate (FDR) and provided more confident peptide identifications. ProVerB is also compatible with various platforms and experimental data sets, showing its robustness and versatility. The open-source program ProVerB is available at http://bioinformatics.jnu.edu.cn/software/proverb/ .

  18. Biokinetics and radiation dosimetry of 14C-labelled triolein, urea, glycocholic acid and xylose in man. Studies related to nuclear medicine 'breath tests' using accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Gunnarsson, Mikael

    2002-08-01

    14 C-labelled substances have been used in biomedical research and clinical medicine for over 50 years. Physicians and scientists however, often hesitate to use these substances in patients and volunteers because the radiation dosimetry is unclear. In this work detailed long-term biokinetic and dosimetric estimation have been carried out for four clinically used 14 C-breath tests: 14 C-triolein (examination of fat malabsorption), urea (detection of Helicobacter pylori infection in the stomach), glycocholic acid and xylose (examination of bacterial overgrowth in the small intestine) by using the highly sensitive accelerator mass-spectrometry (AMS) technique. The AMS technique has been used to measure low 14 C concentrations in small samples of exhaled air, urine, faeces and tissue samples and has improved the base for the estimation of the absorbed dose to various organs and tissues and the effective dose to man. The high sensitivity of the AMS system has also made it possible to perform 14 C breath tests on patient groups which were earlier subject for restriction (e.g. small children). In summary, our results show that for adult patients - and in the case of 14 C-urea breath test also for children down to 3 years of age - the dose contributions are comparatively low, both described as organ doses and as effective doses. For adults, the latter is: 14 C-glycocholic acid - 0.4 mSv/MBq, 14 C-triolein - 0.3 mSv/MBq, 14 C-xylose - 0.1 mSv/MBq and 14 C-urea - 0.04 mSv/MBq. Thus, from a radiation protection point of view there is no reason for restrictions in using any of the 14 C-labelled radiopharmaceutical included in this work in the activities normally used (0.07-0.2 MBq for a 70 kg patient)

  19. Measuring transfer of 14C-PCB from maternal diet to milk in a goat model using an accelerator mass spectrometer (AMS)

    International Nuclear Information System (INIS)

    Janle, E.; Sojka, J.; Jackson, G.S.; Lachcik, P.; Einstien, J.A.; Santerre, C.R.

    2007-01-01

    Environmental pollutants pose a substantial risk to nursing infants. Many of these toxicants (i.e. PCBs, PBDEs, mercury) are passed from the maternal diet to the nursing infant in breast milk. Determining the toxicokinetics has been difficult to measure due to ethical limitations. Since extremely small amounts of 14 C can be measured using Accelerator Mass Spectrometry (AMS), a goat model was used to establish a minimum oral dose of 14 C-labeled PCB (2,2',4,4',5,5'-hexachlorobiphenyl-UL- 14 C) that could be given to a lactating animal and traced into the milk. An oral dose of 66 nCi/kg body weight (1.84 μg PCB/kg bw) was administered. Plasma and milk samples were collected for 2 months after dosing. The concentration of 14 C label reached a peak value of 1.71 ng/ml PCB equivalents in the milk on day 2 and then declined to about 135 pg/ml PCB equivalents in the milk at 3 weeks. A second goat was administered a smaller dose (22 nCi/kg bw; 616 ng PCB/kg bw). A peak concentration of 485 pg PCB equivalents/ml milk occurred at 3 days and declined to 77.6 pg PCB equivalents/ml milk by 3 weeks. Our results indicated that an even lower dosage of labeled-PCB could be used due to the extreme sensitivity of AMS measurement. Extrapolating from current data it is estimated that the dose could be reduced by a factor of 20 (31 ng PCB/kg bw; 1.1 nCi/kg bw) and still be detectable after 2 months. Thus, the potential exists for developing protocols for studying toxicokinetics in humans using radiologically- and toxicologically-benign doses of labeled environmental toxicants

  20. Validation of an accelerated solvent extraction liquid chromatography-tandem mass spectrometry method for Pacific ciguatoxin-1 in fish flesh and comparison with the mouse neuroblastoma assay.

    Science.gov (United States)

    Wu, Jia Jun; Mak, Yim Ling; Murphy, Margaret B; Lam, James C W; Chan, Wing Hei; Wang, Mingfu; Chan, Leo L; Lam, Paul K S

    2011-07-01

    Ciguatera fish poisoning (CFP) is a global foodborne illness caused by consumption of seafood containing ciguatoxins (CTXs) originating from dinoflagellates such as Gambierdiscus toxicus. P-CTX-1 has been suggested to be the most toxic CTX, causing ciguatera at 0.1 μg/kg in the flesh of carnivorous fish. CTXs are structurally complex and difficult to quantify, but there is a need for analytical methods for CFP toxins in coral reef fishes to protect human health. In this paper, we describe a sensitive and rapid extraction method using accelerated solvent extraction combined with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) for the detection and quantification of P-CTX-1 in fish flesh. By the use of a more sensitive MS system (5500 QTRAP), the validated method has a limit of quantification (LOQ) of 0.01 μg/kg, linearity correlation coefficients above 0.99 for both solvent- and matrix-based standard solutions as well as matrix spike recoveries ranging from 49% to 85% in 17 coral reef fish species. Compared with previous methods, this method has better overall recovery, extraction efficiency and LOQ. Fish flesh from 12 blue-spotted groupers (Cephalopholis argus) was assessed for the presence of CTXs using HPLC-MS/MS analysis and the commonly used mouse neuroblastoma assay, and the results of the two methods were strongly correlated. This method is capable of detecting low concentrations of P-CTX-1 in fish at levels that are relevant to human health, making it suitable for monitoring of suspected ciguateric fish both in the environment and in the marketplace.

  1. Accelerated benzene polycarboxylic acid analysis by liquid chromatography-time-of-flight-mass spectrometry for the determination of petrogenic and pyrogenic carbon.

    Science.gov (United States)

    Hindersmann, Benjamin; Achten, Christine

    2017-08-11

    Pyrogenic carbon species are of particular interest due to their ubiquitous occurrence in the environment and their high sorption capacities for nonpolar organic compounds. It has recently been shown that the analysis of the molecular markers for complex aromatic carbon structures, benzene polycarboxylic acids (BPCA), has a high potential for aid in the identification of different carbon sources. In this study, the first LC method using mass spectrometry (MS) for reliable and accelerated (carbon by BPCA analysis has been developed. The main advantage of LC-MS compared to previous methods is the higher sensitivity, which is important if only small sample amounts are available. Sample pre-treatment could be reduced to a minimum. Deuterated phthalic acid was introduced as internal standard due to its structural similarity to BPCA and its lack of occurrence in the environment. Linear quantification with r 2 ≥0997 was accomplished for all BPCA. Method validation showed an excellent quantification reproducibility (mean CVcarbon, large amounts of petrogenic carbon species can also be present in urban soils and river sediments, especially in mining regions. They also to a large degree consist of aromatic carbon structures and therefore have an impact on source identification by BPCA analysis. Comparison of petrogenic and pyrogenic carbon samples shows similarities in the BPCA concentrations and patterns, in their aromaticity and degree of aromatic condensation. Thus, a differentiation between petrogenic and pyrogenic carbon only by BPCA analysis of samples with unknown carbon sources is not possible. For reliable source identification of the carbon species, the combination with other methods, such as e. g. analysis of polycyclic aromatic hydrocarbons may be successful. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Accelerator Service

    International Nuclear Information System (INIS)

    Champelovier, Y.; Ferrari, M.; Gardon, A.; Hadinger, G.; Martin, J.; Plantier, A.

    1998-01-01

    Since the cessation of the operation of hydrogen cluster accelerator in July 1996, four electrostatic accelerators were in operation and used by the peri-nuclear teams working in multidisciplinary collaborations. These are the 4 MV Van de Graaff accelerator, 2,5 MV Van de Graaff accelerator, 400 kV ion implanter as well as the 120 kV isotope separator

  3. Discovery of undefined protein cross-linking chemistry: a comprehensive methodology utilizing 18O-labeling and mass spectrometry.

    Science.gov (United States)

    Liu, Min; Zhang, Zhongqi; Zang, Tianzhu; Spahr, Chris; Cheetham, Janet; Ren, Da; Zhou, Zhaohui Sunny

    2013-06-18

    Characterization of protein cross-linking, particularly without prior knowledge of the chemical nature and site of cross-linking, poses a significant challenge, because of their intrinsic structural complexity and the lack of a comprehensive analytical approach. Toward this end, we have developed a generally applicable workflow-XChem-Finder-that involves four stages: (1) detection of cross-linked peptides via (18)O-labeling at C-termini; (2) determination of the putative partial sequences of each cross-linked peptide pair using a fragment ion mass database search against known protein sequences coupled with a de novo sequence tag search; (3) extension to full sequences based on protease specificity, the unique combination of mass, and other constraints; and (4) deduction of cross-linking chemistry and site. The mass difference between the sum of two putative full-length peptides and the cross-linked peptide provides the formulas (elemental composition analysis) for the functional groups involved in each cross-linking. Combined with sequence restraint from MS/MS data, plausible cross-linking chemistry and site were inferred, and ultimately confirmed, by matching with all data. Applying our approach to a stressed IgG2 antibody, 10 cross-linked peptides were discovered and found to be connected via thioethers originating from disulfides at locations that had not been previously recognized. Furthermore, once the cross-link chemistry was revealed, a targeted cross-link search yielded 4 additional cross-linked peptides that all contain the C-terminus of the light chain.

  4. The French accelerator mass spectrometry facility ASTER after 4 years: Status and recent developments on {sup 36}Cl and {sup 129}I

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, Maurice; Aumaitre, Georges; Bourles, Didier L.; Keddadouche, Karim [ASTER-Team, CNRS-IRD Aix-Marseille Universite, F-13545 Aix-en-Provence (France); CEREGE, CNRS-IRD Aix-Marseille,Universite, F-13545 Aix-en-Provence (France); Braucher, Regis [CEREGE, CNRS-IRD Aix-Marseille,Universite, F-13545 Aix-en-Provence (France); Finkel, Robert C. [CEREGE, CNRS-IRD Aix-Marseille,Universite, F-13545 Aix-en-Provence (France); Earth and Planetary Science Dept., UC Berkeley, Berkeley, CA 94720-4767 (United States); Nottoli, Emmanuelle; Benedetti, Lucilla [CEREGE, CNRS-IRD Aix-Marseille,Universite, F-13545 Aix-en-Provence (France); Merchel, Silke, E-mail: s.merchel@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, D-01314 Dresden (Germany)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer Yearly sample throughput as high as over 3300 unknowns for {sup 10}Be in 2010. Black-Right-Pointing-Pointer {sup 35}Cl/{sup 37}Cl samples proved time dependent mass fractionation and/or source memory. Black-Right-Pointing-Pointer Need for improvement in measurement strategies, data evaluation and ion sources. Black-Right-Pointing-Pointer Cross-calibration of secondary in-house {sup 129}I standards vs. NIST 3231. Black-Right-Pointing-Pointer Cross-contamination for iodine {approx}0.5% within first 20 h of source running. - Abstract: Since the acceptance tests of the French 5 MV accelerator mass spectrometry facility ASTER in 2007, routine measurement conditions for the long-lived radionuclides {sup 10}Be and {sup 26}Al have been established. Yearly sample throughput as high as over 3300 unknowns has been reached for {sup 10}Be in 2010. Cross-contamination for volatile elements has been largely solved by an ion source upgrade allowing {sup 36}Cl measurements at ASTER. However, recent long-term tests using {sup 35}Cl/{sup 37}Cl samples with strongly varying ratios have shown that identical targets lead to different {sup 35}Cl/{sup 37}Cl results at the 2-4% level when being measured after a time gap of 24 h while the source is running other samples. Besides time dependent mass fractionation, another likely reason for this effect might be source memory, thus, asking for sophisticated measurement strategies and improved data evaluation and eventually further ion source improvement. Finally, after establishing quality assurance by cross-calibration of secondary in-house {sup 26}Al and {sup 41}Ca standards and taking part in round-robin exercises of {sup 10}Be and {sup 36}Cl, a two-step cross-calibration of secondary in-house {sup 129}I standards has been performed. The NIST 3231 standard containing {sup 129}I/{sup 127}I at (0.981 {+-} 0.012) Multiplication-Sign 10{sup -6} has been used for step-wise dilution with NaI to produce

  5. Collective field accelerator

    International Nuclear Information System (INIS)

    Luce, J.S.

    1978-01-01

    A collective field accelerator which operates with a vacuum diode and utilizes a grooved cathode and a dielectric anode that operates with a relativistic electron beam with a ν/γ of approx. 1, and a plurality of dielectric lenses having an axial magnetic field thereabout to focus the collectively accelerated electrons and ions which are ejected from the anode. The anode and lenses operate as unoptimized r-f cavities which modulate and focus the beam

  6. HEAVY ION LINEAR ACCELERATOR

    Science.gov (United States)

    Van Atta, C.M.; Beringer, R.; Smith, L.

    1959-01-01

    A linear accelerator of heavy ions is described. The basic contributions of the invention consist of a method and apparatus for obtaining high energy particles of an element with an increased charge-to-mass ratio. The method comprises the steps of ionizing the atoms of an element, accelerating the resultant ions to an energy substantially equal to one Mev per nucleon, stripping orbital electrons from the accelerated ions by passing the ions through a curtain of elemental vapor disposed transversely of the path of the ions to provide a second charge-to-mass ratio, and finally accelerating the resultant stripped ions to a final energy of at least ten Mev per nucleon.

  7. Utilizing a Robotic Sprayer for High Lateral and Mass Resolution MALDI FT-ICR MSI of Microbial Cultures

    Energy Technology Data Exchange (ETDEWEB)

    Anderton, Christopher R.; Chu, Rosalie K.; Tolic, Nikola; Creissen, Alain V.; Pasa-Tolic, Ljiljana

    2016-01-07

    The ability to visualize biochemical interactions between microbial communities using MALDI MSI has provided tremendous insights into a variety of biological fields. Matrix application using a sieve proved to be incredibly useful, but it had many limitations that include uneven matrix coverage and limitation in the types of matrices one could employ in their studies. Recently, there has been a concerted effort to improve matrix application for studying agar plated microbial cultures, many of which utilized automated matrix sprayers. Here, we describe the usefulness of using a robotic sprayer for matrix application. The robotic sprayer has two-dimensional control over where matrix is applied and a heated capillary that allows for rapid drying of the applied matrix. This method provided a significant increase in MALDI sensitivity over the sieve method, as demonstrated by FT-ICR MS analysis, facilitating the ability to gain higher lateral resolution MS images of Bacillus Subtilis than previously reported. This method also allowed for the use of different matrices to be applied to the culture surfaces.

  8. Analysis of intracellular and extracellular microcystin variants in sediments and pore waters by accelerated solvent extraction and high performance liquid chromatography-tandem mass spectrometry

    International Nuclear Information System (INIS)

    Zastepa, Arthur; Pick, Frances R.; Blais, Jules M.; Saleem, Ammar

    2015-01-01

    Highlights: • First analytical method for intracellular microcystins (MCs) in sediment. • Includes a suite of variants (LR, 7dm LR, RR, YR, WR, LA, LF, LY, LW) and nodularin. • Reports the first measurements of MCs in sediment pore waters. • MCs detected in >100 year old lake sediments suggesting long-term preservation. • Sediment-pore water distribution (K d ) differed between variants suggesting differences in environmental fate. - Abstract: The fate and persistence of microcystin cyanotoxins in aquatic ecosystems remains poorly understood in part due to the lack of analytical methods for microcystins in sediments. Existing methods have been limited to the extraction of a few extracellular microcystins of similar chemistry. We developed a single analytical method, consisting of accelerated solvent extraction, hydrophilic–lipophilic balance solid phase extraction, and reversed phase high performance liquid chromatography-tandem mass spectrometry, suitable for the extraction and quantitation of both intracellular and extracellular cyanotoxins in sediments as well as pore waters. Recoveries of nine microcystins, representing the chemical diversity of microcystins, and nodularin (a marine analogue) ranged between 75 and 98% with one, microcystin-RR (MC-RR), at 50%. Chromatographic separation of these analytes was achieved within 7.5 min and the method detection limits were between 1.1 and 2.5 ng g −1 dry weight (dw). The robustness of the method was demonstrated on sediment cores collected from seven Canadian lakes of diverse geography and trophic states. Individual microcystin variants reached a maximum concentration of 829 ng g −1 dw on sediment particles and 132 ng mL −1 in pore waters and could be detected in sediments as deep as 41 cm (>100 years in age). MC-LR, -RR, and -LA were more often detected while MC-YR, -LY, -LF, and -LW were less common. The analytical method enabled us to estimate sediment-pore water distribution coefficients (K d

  9. Analysis of intracellular and extracellular microcystin variants in sediments and pore waters by accelerated solvent extraction and high performance liquid chromatography-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zastepa, Arthur, E-mail: arthur.zastepa@gmail.com; Pick, Frances R.; Blais, Jules M.; Saleem, Ammar

    2015-05-04

    Highlights: • First analytical method for intracellular microcystins (MCs) in sediment. • Includes a suite of variants (LR, {sup 7dm}LR, RR, YR, WR, LA, LF, LY, LW) and nodularin. • Reports the first measurements of MCs in sediment pore waters. • MCs detected in >100 year old lake sediments suggesting long-term preservation. • Sediment-pore water distribution (K{sub d}) differed between variants suggesting differences in environmental fate. - Abstract: The fate and persistence of microcystin cyanotoxins in aquatic ecosystems remains poorly understood in part due to the lack of analytical methods for microcystins in sediments. Existing methods have been limited to the extraction of a few extracellular microcystins of similar chemistry. We developed a single analytical method, consisting of accelerated solvent extraction, hydrophilic–lipophilic balance solid phase extraction, and reversed phase high performance liquid chromatography-tandem mass spectrometry, suitable for the extraction and quantitation of both intracellular and extracellular cyanotoxins in sediments as well as pore waters. Recoveries of nine microcystins, representing the chemical diversity of microcystins, and nodularin (a marine analogue) ranged between 75 and 98% with one, microcystin-RR (MC-RR), at 50%. Chromatographic separation of these analytes was achieved within 7.5 min and the method detection limits were between 1.1 and 2.5 ng g{sup −1} dry weight (dw). The robustness of the method was demonstrated on sediment cores collected from seven Canadian lakes of diverse geography and trophic states. Individual microcystin variants reached a maximum concentration of 829 ng g{sup −1} dw on sediment particles and 132 ng mL{sup −1} in pore waters and could be detected in sediments as deep as 41 cm (>100 years in age). MC-LR, -RR, and -LA were more often detected while MC-YR, -LY, -LF, and -LW were less common. The analytical method enabled us to estimate sediment-pore water

  10. Determination of the Tissue Distribution and Excretion by Accelerator Mass Spectrometry of the Nonadecapeptide 14C-Moli1901 in Beagle dogs after Intratracheal Instillation

    Energy Technology Data Exchange (ETDEWEB)

    Rickert, D E; Dingley, K H; Ubick, E; Dix, K J; Molina, L

    2004-07-02

    Administration of {sup 14}C-Moli1901 (duramycin, 2622U90), a 19 amino acid polycyclic peptide by intratracheal instillation (approximately 100 {micro}g) into the left cranial lobe of the lung of beagle dogs resulted in retention of 64% of the dose in the left cranial lobe for up to 28 days. In this study, we used accelerator mass spectrometry (AMS) to quantify Moli901 following administration of only 0.045 {micro}Ci of {sup 14}C-Moli901 per dog. Limits of quantitation of AMS were 0.03 (urine) to 0.3 (feces) ng equiv. Moli1901/g. Whole blood and plasma concentrations of {sup 14}C were <5ng/ml at all times after the dose. Concentrations of {sup 14}C in whole blood and plasma declined over the first day after the dose and rose thereafter, with the rise in plasma concentrations lagging behind those in whole blood. During the first 3 days after the dose, plasma accounted for the majority of {sup 14}C in whole blood, but after that time, plasma accounted for only 25-30% of the {sup 14}C in whole blood. Tissue (left and right caudal lung lobe, liver, kidney, spleen, brain) and bile concentrations were low, always less than 0.25% the concentrations found in the left cranial lung lobe. Approximately 13% of the dose was eliminated in urine and feces in 28 days, with fecal elimination accounting for about 10% of the dose. The data presented here are consistent with that obtained in other species. Moli1901 is slowly absorbed and excreted from the lung, and it does not accumulate in other tissues. Moli1901 is currently in the clinic and has proven to be safe in single dose studies in human volunteers and cystic fibrosis patients by the inhalation route. No information on the disposition of the compound in humans is available. This study in dogs demonstrates the feasibility of obtaining that information using {sup 14}C-Moli1901 and AMS.

  11. Analysis of intracellular and extracellular microcystin variants in sediments and pore waters by accelerated solvent extraction and high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Zastepa, Arthur; Pick, Frances R; Blais, Jules M; Saleem, Ammar

    2015-05-04

    The fate and persistence of microcystin cyanotoxins in aquatic ecosystems remains poorly understood in part due to the lack of analytical methods for microcystins in sediments. Existing methods have been limited to the extraction of a few extracellular microcystins of similar chemistry. We developed a single analytical method, consisting of accelerated solvent extraction, hydrophilic-lipophilic balance solid phase extraction, and reversed phase high performance liquid chromatography-tandem mass spectrometry, suitable for the extraction and quantitation of both intracellular and extracellular cyanotoxins in sediments as well as pore waters. Recoveries of nine microcystins, representing the chemical diversity of microcystins, and nodularin (a marine analogue) ranged between 75 and 98% with one, microcystin-RR (MC-RR), at 50%. Chromatographic separation of these analytes was achieved within 7.5 min and the method detection limits were between 1.1 and 2.5 ng g(-1) dry weight (dw). The robustness of the method was demonstrated on sediment cores collected from seven Canadian lakes of diverse geography and trophic states. Individual microcystin variants reached a maximum concentration of 829 ng g(-1) dw on sediment particles and 132 ng mL(-1) in pore waters and could be detected in sediments as deep as 41 cm (>100 years in age). MC-LR, -RR, and -LA were more often detected while MC-YR, -LY, -LF, and -LW were less common. The analytical method enabled us to estimate sediment-pore water distribution coefficients (K(d)), MC-RR had the highest affinity for sediment particles (log K(d)=1.3) while MC-LA had the lowest affinity (log K(d)=-0.4), partitioning mainly into pore waters. Our findings confirm that sediments serve as a reservoir for microcystins but suggest that some variants may diffuse into overlying water thereby constituting a new route of exposure following the dissipation of toxic blooms. The method is well suited to determine the fate and persistence of different

  12. Detection, concentrations and distribution of paxilline, an animal neurotoxin, in mouse brain: an application of ultra-high sensitivity detection of 14C by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Roberts, P.B.; Kim, K.

    1999-01-01

    Full text: Paxilline is an intermediate in the biosynthesis of lolitrem neurotoxins that cause the disorder rye grass staggers in livestock grazing on pastures infected with certain fungi. Paxilline itself produces similar symptoms and the 14 C-labelled compound has been produced bio-synthetically at low specific activity. Using conventional liquid scintillation counting it was not possible to detect the labelled compound in the brain of mice sacrificed at the time they displayed physiological symptoms. Accelerator mass spectrometry (AMS) counts 14 C atoms, not decays, and provides sensitivity 10,000-100,000 times greater than conventional scintillation counting of radioactive decays. Measurements are easily obtained at the level of the natural abundance of 14 C in living tissue of 6fCi or 10 -16 moles 14 C per mg total carbon. Extraction of the labelled compound from the tissue is unnecessary and sample size can be 0.01-10mg. Paxilline (8mg/kg ip) was given to 25g mice. The total activity injected was 11,000 dpm though the results showed that 1,000dpm would have been sufficient. The concentration of paxilline in homogenised whole brain was determined to be 985 pg or 0.0075 dpm mg dry tissue. The concentration in the major brain segments ranged from 893-1137 pgmg dry tissue. The spinal cord contained 719 pg/mg dry tissue. Our results suggest that toxicologists and pharmacologists should consider what new information may be obtained by combining tracer studies with the power of AMS detection. The AMS method makes possible great reductions in the amount of label and sample sizes, plus wider ranges in concentration/time course studies. In particular, it opens up new possibilities such as: studies at true dietary or environmental levels; tracer studies in large animal or plant systems; field trials; human studies where radiation dose must be considered; and studies with compounds that can only be synthesised with low specific activity. Copyright (1999) Australasian

  13. Some new features of Direct Analysis in Real Time mass spectrometry utilizing the desorption at an angle option.

    Science.gov (United States)

    Chernetsova, Elena S; Revelsky, Alexander I; Morlock, Gertrud E

    2011-08-30

    The present study is a first step towards the unexplored capabilities of Direct Analysis in Real Time (DART) mass spectrometry (MS) arising from the possibility of the desorption at an angle: scanning analysis of surfaces, including the coupling of thin-layer chromatography (TLC) with DART-MS, and a more sensitive analysis due to the preliminary concentration of analytes dissolved in large volumes of liquids on glass surfaces. In order to select the most favorable conditions for DART-MS analysis, proper positioning of samples is important. Therefore, a simple and cheap technique for the visualization of the impact region of the DART gas stream onto a substrate was developed. A filter paper or TLC plate, previously loaded with the analyte, was immersed in a derivatization solution. On this substrate, owing to the impact of the hot DART gas, reaction of the analyte to a colored product occurred. An improved capability of detection of DART-MS for the analysis of liquids was demonstrated by applying large volumes of model solutions of coumaphos into small glass vessels and drying these solutions prior to DART-MS analysis under ambient conditions. This allowed the introduction of, by up to more than two orders of magnitude, increased quantities of analyte compared with the conventional DART-MS analysis of liquids. Through this improved detectability, the capabilities of DART-MS in trace analysis could be strengthened. Copyright © 2011 John Wiley & Sons, Ltd.

  14. Future accelerators (?)

    Energy Technology Data Exchange (ETDEWEB)

    John Womersley

    2003-08-21

    I describe the future accelerator facilities that are currently foreseen for electroweak scale physics, neutrino physics, and nuclear structure. I will explore the physics justification for these machines, and suggest how the case for future accelerators can be made.

  15. Utility of the RENAL index -Radius; Exophytic/endophytic; Nearness to sinus; Anterior/posterior; Location relative to polar lines- in the management of renal masses.

    Science.gov (United States)

    Konstantinidis, C; Trilla, E; Lorente, D; Morote, J

    2016-12-01

    The growing incidence of renal masses and the wide range of available treatments require predictive tools that support the decision making process. The RENAL index -Radius; Exophytic/endophytic; Nearness to sinus; Anterior/posterior; Location relative to polar lines- helps standardise the anatomy of a renal mass by differentiating 3 groups of complexity. Since the introduction of the index, there have been a growing number of studies, some of which have been conflicting, that have evaluated the clinical utility of its implementation. To analyse the scientific evidence on the relationship between the RENAL index and the main strategies for managing renal masses. A search was conducted in the Medline database, which found 576 references on the RENAL index. In keeping with the PRISM Declaration, we selected 100 abstracts and ultimately reviewed 96 articles. The RENAL index has a high degree of interobserver correlation and has been validated as a predictive nomogram of histological results. In active surveillance, the index has been related to the tumour growth rate and probability of nephrectomy. In ablative therapy, the index has been associated with therapeutic efficacy, complications and tumour recurrence. In partial nephrectomy, the index has been related to the rate of complications, conversion to radical surgery, ischaemia time, function preservation and tumour recurrence, a finding also observed in radical nephrectomy. The RENAL index is an objective, reproducible and useful system as a predictive tool of highly relevant clinical parameters such as the rate of complications, ischaemia time, renal function and oncological results in the various currently accepted treatments for the management of renal masses. Copyright © 2016 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

  16. Evaluation of non-volatile metabolites in beer stored at high temperature and utility as an accelerated method to predict flavour stability.

    Science.gov (United States)

    Heuberger, Adam L; Broeckling, Corey D; Sedin, Dana; Holbrook, Christian; Barr, Lindsay; Kirkpatrick, Kaylyn; Prenni, Jessica E

    2016-06-01

    Flavour stability is vital to the brewing industry as beer is often stored for an extended time under variable conditions. Developing an accelerated model to evaluate brewing techniques that affect flavour stability is an important area of research. Here, we performed metabolomics on non-volatile compounds in beer stored at 37 °C between 1 and 14 days for two beer types: an amber ale and an India pale ale. The experiment determined high temperature to influence non-volatile metabolites, including the purine 5-methylthioadenosine (5-MTA). In a second experiment, three brewing techniques were evaluated for improved flavour stability: use of antioxidant crowns, chelation of pro-oxidants, and varying plant content in hops. Sensory analysis determined the hop method was associated with improved flavour stability, and this was consistent with reduced 5-MTA at both regular and high temperature storage. Future studies are warranted to understand the influence of 5-MTA on flavour and aging within different beer types. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Utility of imaging mass spectrometry (IMS) by matrix-assisted laser desorption ionization (MALDI) on an ion trap mass spectrometer in the analysis of drugs and metabolites in biological tissues.

    Science.gov (United States)

    Drexler, Dieter M; Garrett, Timothy J; Cantone, Joseph L; Diters, Richard W; Mitroka, James G; Prieto Conaway, Maria C; Adams, Stephen P; Yost, Richard A; Sanders, Mark

    2007-01-01

    The properties and potential liabilities of drug candidate are investigated in detailed ADME assays and in toxicity studies, where findings are placed in context of exposure to dosed drug and metabolites. The complex nature of biological samples may necessitate work-up procedures prior to high performance liquid chromatography-mass spectrometric (HPLC-MS) analysis of endogenous or xenobiotic compounds. This concept can readily be applied to biological fluids such as blood or urine, but in localized samples such as organs and tissues potentially important spatial, thus anatomical, information is lost during sample preparation as the result of homogenization and extraction procedures. However, the localization of test article or spatial identification of metabolites may be critical to the understanding of the mechanism of target-organ toxicity and its relevance to clinical safety. Tissue imaging mass spectrometry (IMS) by matrix-assisted laser desorption ionization (MALDI) and ion trap mass spectrometry (MS) with higher order mass spectrometric scanning functions was utilized for localization of dosed drug or metabolite in tissue. Laser capture microscopy (LCM) was used to obtain related samples from tissue for analyses by standard MALDI-MS and HPLC-MS. In a toxicology study, rats were administered with a high dosage of a prodrug for 2 weeks. Birefringent microcrystalline material (10-25 microm) was observed in histopathologic formalin-fixed tissue samples. Direct analysis by IMS provided the identity of material in the microcrystals as circulating active drug while maintaining spatial orientation. Complementary data from visual cross-polarized light microscopy as well as standard MALDI-MS and HPLC-MS experiments on LCM samples validated the qualitative results obtained by IMS. Furthermore, the HPLC-MS analysis on the LCM samples afforded a semi-quantitative assessment of the crystalline material in the tissue samples. IMS by MALDI ion trap MS proved sensitive

  18. Thorium molecular negative ion production in a cesium sputter source at BARC-TIFR pelletron accelerator ion source test set up

    International Nuclear Information System (INIS)

    Gupta, A.K.; Mehrotra, N.; Kale, R.M.; Alamelu, D.; Aggarwal, S.K.

    2005-01-01

    Ion source test set up at Pelletron Accelerator facility has been utilized extensively for the production and characterization of negative ions, with particular emphasis being place at the species of experimental users interest. The attention have been focussed towards the formation of rare earth negative ions, due to their importance in the ongoing accelerator mass spectroscopy program and isotopic abundance measurements using secondary negative ion mass spectrometry

  19. Recent progress in particle accelerators

    International Nuclear Information System (INIS)

    Cole, F.T.; Mills, F.E.

    1988-01-01

    Many accelerators have also been built for medical radiography and therapy. Electron accelerators for this application are available commercially, using the electrons directly or bremsstrahlung photons. Neutrons produced by accelerator beams have also been used for therapy with considerable success, and several proton accelerators built for physics research have been adapted for direct therapy with protons. The first proton accelerator specifically for therapy is now being built. Separate from what might be called conventional accelerator technology, an entirely new field utilizing very highly pulsed power has been developed, and beams of short pulses of thousands or millions of amperes peak current in the MeV energy range are now available. These beams have important applications in high-energy particle acceleration, controlled fusion, industrial treatment of materials, and possibly in food preservation. All of these accelerators make use of external fields of acceleration. There is also vigorous research into new methods of acceleration, in many schemes making use of the intense accelerating fields, generated by laser beams or by plasma states of matter. This research has not as yet made traditional kinds of accelerators outmoded, but many workers hope that early in the next century there will be practical new acceleration methods making use of these very high fields. These developments are discussed in detail

  20. Human Microdosing with Carcinogenic Polycyclic Aromatic Hydrocarbons: In Vivo Pharmacokinetics of Dibenzo[ def,p ]chrysene and Metabolites by UPLC Accelerator Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Madeen, Erin P.; Ognibene, Ted J.; Corley, Richard A.; McQuistan, Tammie J.; Henderson, Marilyn C.; Baird, William M.; Bench, Graham; Turteltaub, Ken W.; Williams, David E.

    2016-10-17

    Metabolism is a key health risk factor following exposures to pro-carcinogenic polycyclic aromatic hydrocarbons (PAHs) such as dibenzo[def,p]chrysene (DBC), an IARC classified 2A probable human carcinogen. Human exposure to PAHs occurs primarily from the diet in non-smokers. However, little data is available on the metabolism and pharmacokinetics in humans of high molecular weight PAHs (≥4 aromatic rings), including DBC. We previously determined the pharmacokinetics of DBC in human volunteers orally administered a micro-dose (29 ng; 5 nCi) of [14C]-DBC by accelerator mass spectrometry (AMS) analysis of total [14C] in plasma and urine. In the current study, we utilized a novel “moving wire” interface between ultra-performance liquid chromatography (UPLC) and AMS to detect and quantify parent DBC and its major metabolites. The major [14C] product identified in plasma was unmetabolized [14C]-DBC itself, (Cmax= 18.5 ± 15.9 fg/mL, Tmax= 2.1 ± 1.0 h), whereas the major metabolite was identified as [14C]-(+/-)-DBC-11,12-diol (Cmax= 2.5 ± 1.3 fg/mL, Tmax= 1.8 h). Several minor species of [14C]-DBC metabolites were also detected for which no reference standards were available. Free and conjugated metabolites were detected in urine with [14C]-(+/-)-DBC-11,12,13,14-tetraol isomers identified as the major metabolites, 56.3% of which were conjugated (Cmax= 35.8 ± 23.0 pg/pool, Tmax= 6-12 h pool). [14C]-DBC-11,12-diol, of which 97.5% was conjugated, was also identified in urine (Cmax= 29.4 ± 11.6 pg/pool, Tmax= 6-12 h pool). Parent [14C]-DBC was not detected in urine. This is the first dataset to assess metabolite profiles and associated pharmacokinetics of a carcinogenic PAH in human volunteers at an environmentally relevant dose, providing the data necessary for translation of high dose animal models to humans for translation of environmental health risk assessment.

  1. A combined accelerator mass spectrometry-positron emission tomography human microdose study with 14C- and 11C-labelled verapamil.

    Science.gov (United States)

    Wagner, Claudia C; Simpson, Marie; Zeitlinger, Markus; Bauer, Martin; Karch, Rudolf; Abrahim, Aiman; Feurstein, Thomas; Schütz, Matthias; Kletter, Kurt; Müller, Markus; Lappin, Graham; Langer, Oliver

    2011-02-01

    In microdose studies, the pharmacokinetic profile of a drug in blood after administration of a dose up to 100 μg is measured with sensitive analytical techniques, such as accelerator mass spectrometry (AMS). As most drugs exert their effect in tissue rather than blood, methodology is needed for extending pharmacokinetic analysis to different tissue compartments. In the present study, we combined, for the first time, AMS analysis with positron emission tomography (PET) in order to determine the pharmacokinetic profile of the model drug verapamil in plasma and brain of humans. In order to assess pharmacokinetic dose linearity of verapamil, data were acquired and compared after administration of an intravenous microdose and after an intravenous microdose administered concomitantly with an oral therapeutic dose. Six healthy male subjects received an intravenous microdose [0.05 mg] (period 1) and an intravenous microdose administered concomitantly with an oral therapeutic dose [80 mg] of verapamil (period 2) in a randomized, crossover, two-period study design. The intravenous dose was a mixture of (R/S)-[14C]verapamil and (R)-[11C]verapamil and the oral dose was unlabelled racaemic verapamil. Brain distribution of radioactivity was measured with PET whereas plasma pharmacokinetics of (R)- and (S)-verapamil were determined with AMS. PET data were analysed by pharmacokinetic modelling to estimate the rate constants for transfer (k) of radioactivity across the blood-brain barrier. Most pharmacokinetic parameters of (R)- and (S)-verapamil as well as parameters describing exchange of radioactivity between plasma and brain (influx rate constant [K(1)] = 0.030 ± 0.003 and 0.031 ± 0.005 mL/mL/min and efflux rate constant [k(2)] = 0.099 ± 0.006 and 0.095 ± 0.008 min-1 for period 1 and 2, respectively) were not statistically different between the two periods although there was a trend for nonlinear pharmacokinetics for the (R)-enantiomer. On the other hand, all

  2. The accelerator breeder

    International Nuclear Information System (INIS)

    Johansson, E.

    1986-01-01

    Interactions of high-energy particles with atomic nuclei, in particular heavy ones, leads to a strong emission of neutrons. Preferably these high-energy particles are protons or deuterons obtained from a linear accelerator. The neutrons emitted are utilized in the conversion of U238 to Pu239 or of Th232 to U233. The above is the basis of the accelerator breeder, a concept studied abroad in many variants. No such breeder has, however, so far been built, but there exists vast practical experience on the neutron production and on the linear accelerator. Some of the variants mentioned are described in the report, after a presentation of general characteristics for the particle-nucleus interaction and for the linear accelerator. (author)

  3. Electron accelerators for waste processing

    International Nuclear Information System (INIS)

    Kon'kov, N.G.

    1976-01-01

    The documents of the International symposium on radiation vaste processing are presented. Questions on waste utilization with the help of electron accelerators are considered. The electron accelerators are shown to have an advantage over some other ionizing radiation sources. A conclusion is made that radiation methods of waste processing are extensively elaborated in many developed countries. It has been pointed out that an electron accelerator is a most cheap and safe ionizing radiation source primarily for processing of gaseous and liquid wastes

  4. The Brookhaven National Laboratory Accelerator Test Facility

    International Nuclear Information System (INIS)

    Batchelor, K.

    1992-01-01

    The Brookhaven National Laboratory Accelerator Test Facility comprises a 50 MeV traveling wave electron linear accelerator utilizing a high gradient, photo-excited, raidofrequency electron gun as an injector and an experimental area for study of new acceleration methods or advanced radiation sources using free electron lasers. Early operation of the linear accelerator system including calculated and measured beam parameters are presented together with the experimental program for accelerator physics and free electron laser studies

  5. Electrostatic accelerators

    OpenAIRE

    Hinterberger, F

    2006-01-01

    The principle of electrostatic accelerators is presented. We consider Cockcroft– Walton, Van de Graaff and Tandem Van de Graaff accelerators. We resume high voltage generators such as cascade generators, Van de Graaff band generators, Pelletron generators, Laddertron generators and Dynamitron generators. The speci c features of accelerating tubes, ion optics and methods of voltage stabilization are described. We discuss the characteristic beam properties and the variety of possible beams. We ...

  6. Electrostatic accelerators

    CERN Document Server

    Hinterberger, F

    2006-01-01

    The principle of electrostatic accelerators is presented. We consider Cockcroft– Walton, Van de Graaff and Tandem Van de Graaff accelerators. We resume high voltage generators such as cascade generators, Van de Graaff band generators, Pelletron generators, Laddertron generators and Dynamitron generators. The speci c features of accelerating tubes, ion optics and methods of voltage stabilization are described. We discuss the characteristic beam properties and the variety of possible beams. We sketch possible applications and the progress in the development of electrostatic accelerators.

  7. The Utility of Mass Violence

    Science.gov (United States)

    2009-09-01

    antibiotic treatment, the C-dif bacteria will overpopulate and overrun the intestines and colon. This infestation causes weakness, dehydration, fever...intervened on several fronts. They curbed the Ottoman’s trade monopoly and established their own naval routes to Asia . Vast imports of Spanish silver

  8. A national quitline service and its promotion in the mass media: modelling the health gain, health equity and cost-utility.

    Science.gov (United States)

    Nghiem, Nhung; Cleghorn, Christine L; Leung, William; Nair, Nisha; Deen, Frederieke S van der; Blakely, Tony; Wilson, Nick

    2017-07-24

    Mass media campaigns and quitlines are both important distinct components of tobacco control programmes around the world. But when used as an integrated package, the effectiveness and cost-effectiveness are not well described. We therefore aimed to estimate the health gain, health equity impacts and cost-utility of the package of a national quitline service and its promotion in the mass media. We adapted an established Markov and multistate life-table macro-simulation model. The population was all New Zealand adults in 2011. Effect sizes and intervention costs were based on past New Zealand quitline data. Health system costs were from a national data set linking individual health events to costs. The 1-year operation of the existing intervention package of mass media promotion and quitline service was found to be net cost saving to the health sector for all age groups, sexes and ethnic groups (saving $NZ84 million; 95%uncertainty interval 60-115 million in the base-case model). It also produced greater per capita health gains for Māori (indigenous) than non-Māori (2.2 vs 0.73 quality-adjusted life-years (QALYs) per 1000 population, respectively). The net cost saving of the intervention was maintained in all sensitivity and scenario analyses for example at a discount rate of 6% and when the intervention effect size was quartered (given the possibility of residual confounding in our estimates of smoking cessation). Running the intervention for 20 years would generate an estimated 54 000 QALYs and $NZ1.10 billion (US$0.74 billion) in cost savings. The package of a quitline service and its promotion in the mass media appears to be an effective means to generate health gain, address health inequalities and save health system costs. Nevertheless, the role of this intervention needs to be compared with other tobacco control and health sector interventions, some of which may be even more cost saving. © Article author(s) (or their employer(s) unless otherwise

  9. Current trends in non-accelerator particle physics: 1, Neutrino mass and oscillation. 2, High energy neutrino astrophysics. 3, Detection of dark matter. 4, Search for strange quark matter. 5, Magnetic monopole searches

    International Nuclear Information System (INIS)

    He, Yudong

    1995-07-01

    This report is a compilation of papers reflecting current trends in non-accelerator particle physics, corresponding to talks that its author was invited to present at the Workshop on Tibet Cosmic Ray Experiment and Related Physics Topics held in Beijing, China, April 4--13, 1995. The papers are entitled 'Neutrino Mass and Oscillation', 'High Energy Neutrino Astrophysics', 'Detection of Dark Matter', 'Search for Strange Quark Matter', and 'Magnetic Monopole Searches'. The report is introduced by a survey of the field and a brief description of each of the author's papers

  10. Microdroplets Accelerate Ring Opening of Epoxides

    Science.gov (United States)

    Lai, Yin-Hung; Sathyamoorthi, Shyam; Bain, Ryan M.; Zare, Richard N.

    2018-03-01

    The nucleophilic opening of an epoxide is a classic organic reaction that has widespread utility in both academic and industrial applications. We have studied the reaction of limonene oxide with morpholine to form 1-methyl-2-morpholino-4-(prop-1-en-2-yl) cyclohexan-1-ol in bulk solution and in electrosprayed microdroplets with a 1:1 v/v water/methanol solvent system. We find that even after 90 min at room temperature, there is no product detected by nuclear magnetic resonance spectroscopy in bulk solution whereas in room-temperature microdroplets (2-3 μm in diameter), the yield is already 0.5% in a flight time of 1 ms as observed by mass spectrometry. This constitutes a rate acceleration of 105 in the microdroplet environment, if we assume that as much as 5% of product is formed in bulk after 90 min of reaction time. We examine how the reaction rate depends on droplet size, solvent composition, sheath gas pressure, and applied voltage. These factors profoundly influence the extent of reaction. This dramatic acceleration is not limited to just one system. We have also found that the nucleophilic opening of cis-stilbene oxide by morpholine is similarly accelerated. Such large acceleration factors in reaction rates suggest the use of microdroplets for ring opening of epoxides in other systems, which may have practical significance if such a procedure could be scaled. [Figure not available: see fulltext.

  11. Microdroplets Accelerate Ring Opening of Epoxides

    Science.gov (United States)

    Lai, Yin-Hung; Sathyamoorthi, Shyam; Bain, Ryan M.; Zare, Richard N.

    2018-05-01

    The nucleophilic opening of an epoxide is a classic organic reaction that has widespread utility in both academic and industrial applications. We have studied the reaction of limonene oxide with morpholine to form 1-methyl-2-morpholino-4-(prop-1-en-2-yl) cyclohexan-1-ol in bulk solution and in electrosprayed microdroplets with a 1:1 v/ v water/methanol solvent system. We find that even after 90 min at room temperature, there is no product detected by nuclear magnetic resonance spectroscopy in bulk solution whereas in room-temperature microdroplets (2-3 μm in diameter), the yield is already 0.5% in a flight time of 1 ms as observed by mass spectrometry. This constitutes a rate acceleration of 105 in the microdroplet environment, if we assume that as much as 5% of product is formed in bulk after 90 min of reaction time. We examine how the reaction rate depends on droplet size, solvent composition, sheath gas pressure, and applied voltage. These factors profoundly influence the extent of reaction. This dramatic acceleration is not limited to just one system. We have also found that the nucleophilic opening of cis-stilbene oxide by morpholine is similarly accelerated. Such large acceleration factors in reaction rates suggest the use of microdroplets for ring opening of epoxides in other systems, which may have practical significance if such a procedure could be scaled. [Figure not available: see fulltext.

  12. RECIRCULATING ACCELERATION

    International Nuclear Information System (INIS)

    BERG, J.S.; GARREN, A.A.; JOHNSTONE, C.

    2000-01-01

    This paper compares various types of recirculating accelerators, outlining the advantages and disadvantages of various approaches. The accelerators are characterized according to the types of arcs they use: whether there is a single arc for the entire recirculator or there are multiple arcs, and whether the arc(s) are isochronous or non-isochronous

  13. LIBO accelerates

    CERN Multimedia

    2002-01-01

    The prototype module of LIBO, a linear accelerator project designed for cancer therapy, has passed its first proton-beam acceleration test. In parallel a new version - LIBO-30 - is being developed, which promises to open up even more interesting avenues.

  14. Accelerating Inspire

    CERN Document Server

    AUTHOR|(CDS)2266999

    2017-01-01

    CERN has been involved in the dissemination of scientific results since its early days and has continuously updated the distribution channels. Currently, Inspire hosts catalogues of articles, authors, institutions, conferences, jobs, experiments, journals and more. Successful orientation among this amount of data requires comprehensive linking between the content. Inspire has lacked a system for linking experiments and articles together based on which accelerator they were conducted at. The purpose of this project has been to create such a system. Records for 156 accelerators were created and all 2913 experiments on Inspire were given corresponding MARC tags. Records of 18404 accelerator physics related bibliographic entries were also tagged with corresponding accelerator tags. Finally, as a part of the endeavour to broaden CERN's presence on Wikipedia, existing Wikipedia articles of accelerators were updated with short descriptions and links to Inspire. In total, 86 Wikipedia articles were updated. This repo...

  15. Hydrologic and geochemical controls on the transport of radionuclides in natural undisturbed arid environments as determined by accelerator mass spectrometry measurements

    International Nuclear Information System (INIS)

    Nimz, G; Caffee, M W; McAninch, J

    2000-01-01

    This project developed techniques for measuring globally distributed radionuclides that occur today in extremely low abundances (''fallout'' from the era of atmospheric nuclear testing), and then applied these techniques to better understand the mechanisms by which radionuclides migrate. The techniques employ accelerator mass spectrometry (AMS), a relatively new analytical tool that permits this work to be conducted for the first time. The goal in this project was to develop AMS analytical techniques for 129 I (fallout concentration: ∼ 10 6 atoms/g) 99 Tc (∼ 10 9 atoms/g), 90 Sr (∼10 7 atoms/gram soil), and 93 Zr (∼ 10 9 atoms/g), and improved methods for 36 Cl (∼ 10 9 atoms/g). As a demonstration of the analytical techniques, and as an investigation of identified problems associated with characterizing moisture and radionuclide movement in unsaturated desert soils, we developed a vadose zone research site at the Nevada Test Site. Our findings can be summarized as follows: (1) The distribution of chloride and 36 Cl at the research site indicates that the widely-used ''chloride accumulation'' method for estimating moisture flux is erroneous; some mechanism for attenuation of chloride exists, violating an assumption of the accumulation method; (2) 129 I is fractionated into several soil compartments that have varying migration abilities; the two most mobile can be tentatively identified as Fe/Mn oxyhydroxides and organic acids based on our sequential leaching techniques; (3) These most mobile constituents are capable of migrating at a rate greater than that of 36 Cl, usually considered the most mobile solute in hydrologic systems; these constituents may be colloidal in character, of neutral surface charge, and therefore conservative in aqueous migration; (4) 99 Tc is readily measurable by AMS, as we demonstrate by the first AMS 99 Tc measurements of contaminated waters; extraction of 99 Tc from silicate soils is difficult, but can be done using the extended

  16. Development of heavy ion linear accelerators

    International Nuclear Information System (INIS)

    Bomko, V.A.; Khizhnyak, N.A.

    1981-01-01

    A review of the known heavy ion accelerators is given. It is stated that cyclic and linear accelerators are the most perspective ones in the energy range up to 10 MeV/nucleon according to universality in respect with the possibility of ion acceleration of the wide mass range. However, according to the accelerated beam intensity of the heavier ions the linear accelerators have considerable advantages over any other types of accelerators. The review of the known heavy ion linac structures permits to make the conclusion that a new modification of an accelerating structure of opposite pins excited on a H-wave is the most perspective one [ru

  17. Calorimetric low-temperature detectors for low-energy (E≤1 MeV/amu) heavy ions and their first application in the accelerator mass spectroscopy for trace analysis of 236U

    International Nuclear Information System (INIS)

    Kraft-Bermuth, S.

    2004-01-01

    In the thesis presented here, calorimetric low temperature detectors were for the first time applied in accelerator mass spectrometry (AMS) to determine the isotope ratio of 236 U to 238 U in several samples of natural uranium. The detectors consist of a superconducting aluminium film deposited onto a sapphire absorber which is used as thermistor. An energetic heavy ion deposits its kinetic energy as heat in the absorber. The temperature rise is detected by the resistance change of the superconductor. The AMS experiments were performed at the tandem accelerator VERA of the ''Institut fuer Isotopenforschung und Kernphysik'' of the University of Vienna. In an energy range of 10-60 MeV, a relative energy resolution of ΔE/E=7.10 -3 could be achieved, one order of magnitude better than with conventional ionization detectors. Improving thermal and electronic noise yielded in a second experiment for uranium ions with E=17 MeV a relative energy resolution of ΔE/E=4.6.10 -3 . The energy response of the detectors was linear over the whole energy range and independent of the ion mass. Down to a level of 0.1%, no pulse height defect was observed. With the energy resolution obtained it is possible to determine the isotope ratio of 236 U/ 238 U for several samples of natural uranium. With the resolution achieved it is possible furthermore to apply the detectors in several test experiments for direct mass identification of heavy ions using a combined energy/time of flight measurement. In these first tests, a mass resolution of ΔM/M=(8.5-11.0).10 -3 was achieved. In a first test to apply the detectors for detection of so called ''super heavy elements (Z>=112)'', the large dynamic range allowed to identify the reaction products and their alpha decays simultaneously and time dependent. (orig.)

  18. Laser wakefield acceleration

    International Nuclear Information System (INIS)

    Esarey, E.; Ting, A.; Sprangle, P.

    1989-01-01

    The laser wakefield accelerator (LWFA) is a novel plasma based electron acceleration scheme which utilizes a relativistic optical guiding mechanism for laser pulse propagation. In the LWFA, a short, high power, single frequency laser pulse is propagated through a plasma. As the laser pulse propagates, its radial and axial ponderomotive forces nonresonantly generate large amplitude plasma waves (wakefields) with a phase velocity equal to the group velocity of the pulse. A properly phased electron bunch may then be accelerated by the axial wakefield and focused by the transverse wakefield. Optical guiding of the laser pulse in the plasma is necessary in order to achieve high energies in a single stage of acceleration. At sufficiently high laser powers, optical guiding may be achieved through relativistic effects associated with the plasma electrons. Preliminary analysis indicates that this scheme may overcome some of the difficulties present in the plasma beat wave accelerator and in the plasma wakefield accelerator. Analytical and numerical calculations are presented which study both laser pulse propagation within a plasma as well as the subsequent generation of large amplitude plasma waves. In addition, the generation of large amplitude plasma waves in regimes where the plasma waves become highly nonlinear is examined

  19. Accuracy and Utility of Estimating Lean Body Mass and Nutritional Status in Patients with Chronic Kidney Disease on Long-Term Hemodialysis Using Anthropometric Skinfold Thickness Measurements.

    Science.gov (United States)

    Leong, Khai Gene; Chee, Jia Lian; Karahalios, Amalia; Skelley, Annabelle; Wong, Kim

    2018-01-01

    Malnutrition is common in patients on hemodialysis (prevalence of 30% to 50%) and is associated with higher mortality. Lean body mass (LBM) assessment is an accurate way of assessing nutritional status. The dual-energy X-ray absorptiometry (DEXA) scan is a reliable method in assessing body compositions and LBM; however, it is expensive and largely inaccessible. Anthropometric skinfold thickness measurement (ASFM) is useful in assessing LBM. It is cheaper and accessible, but underutilized clinically. The subjective global score (SGA) is a well-established method of assessing nutritional status. All three methods of assessing nutritional status were compared. In this pilot observational study, there was a significant correlation between LBM% estimated by DEXA and ASFM (mean difference -1.46% [95% CI -4.09 to 1.18]; LOA -14.0 to 11.1). Nutritional status by SGA could only detect those severely malnourished when using LBM% by ASFM as comparison. Our study demonstrated that ASFM is a useful method of assessing LBM and nutritional status, which can be easily utilized clinically. Copyright© by the American Nephrology Nurses Association.

  20. Utilization of marble from Bejui mine - Currais Novos/RN in ceramic mass; Analise da incorporacao de marmore da mina Brejui - Currais Novos/RN na massa ceramica

    Energy Technology Data Exchange (ETDEWEB)

    Farias, D.S.U. de; Souza, M.M. de; Almeida, A.B.D. de; Lima, T.C. de; Nobrega, L.F.P. de M. [Instituto Federal de Ciencia e Tecnologia do Rio Grande do Norte (IFRN), Natal, RN (Brazil); Mendes, L.B., E-mail: debora_suf_00@hotmail.com [Fundacao de Apoio a Pesquisa do Rio Grande do Norte (FAPERN), Natal RN (Brazil)

    2016-07-01

    Mining in Mine Brejui, in Currais Novos - RN, is related to the extraction of scheelite, however the marble of the region is not fully tapped. Aiming to provide a utility to this carbonate rock very abundant in the Serido region, this work is to evaluate, from its chemical and other tests, the addition of marble in the ceramic mass. For the analysis, the samples were collected, then comminuted and sieved to #200 and, right after, characterized by fluorescence X-ray method (FRX). The results indicate a high concentration of CaO (95%), a flux element, and very low content of Fe{sub 2}O{sub 3} and SO{sub 3} (less than 0.6%). After produced the samples, there were performed the water absorption tests and linear shrinkage, which has indicate satisfactory results and classifying them as porcelain. Therefore, with the significant potential of the marble, other laboratory tests may be performed to analyze its incorporation in the formulation of ceramic bodies, being economically viable and adding proper use and commercial value to the rock. (author)

  1. FMIT accelerator

    International Nuclear Information System (INIS)

    Armstrong, D.D.

    1983-01-01

    A 35-MeV 100-mA cw linear accelerator is being designed by Los Alamos for use in the Fusion Materials Irradiation Test (FMIT) Facility. Essential to this program is the design, construction, and evaluation of performance of the accelerator's injector, low-energy beam transport, and radio-frequency quadrupole sections before they are shipped to the facility site. The installation and testing of some of these sections have begun as well as the testing of the rf, noninterceptive beam diagnostics, computer control, dc power, and vacuum systems. An overview of the accelerator systems and the performance to date is given

  2. Electron accelerator

    International Nuclear Information System (INIS)

    Abramyan.

    1981-01-01

    The USSR produces an electron accelerator family of a simple design powered straight from the mains. The specifications are given of accelerators ELITA-400, ELITA-3, ELT-2, TEUS-3 and RIUS-5 with maximum electron energies of 0.3 to 5 MeV, a mean power of 10 to 70 kW operating in both the pulsed and the continuous (TEUS-3) modes. Pulsed accelerators ELITA-400 and ELITA-3 and RIUS-5 in which TESLA resonance transformers are used are characterized by their compact size. (Ha)

  3. Horizontal Accelerator

    Data.gov (United States)

    Federal Laboratory Consortium — The Horizontal Accelerator (HA) Facility is a versatile research tool available for use on projects requiring simulation of the crash environment. The HA Facility is...

  4. Acceleration theorems

    International Nuclear Information System (INIS)

    Palmer, R.

    1994-06-01

    Electromagnetic fields can be separated into near and far components. Near fields are extensions of static fields. They do not radiate, and they fall off more rapidly from a source than far fields. Near fields can accelerate particles, but the ratio of acceleration to source fields at a distance R, is always less than R/λ or 1, whichever is smaller. Far fields can be represented as sums of plane parallel, transversely polarized waves that travel at the velocity of light. A single such wave in a vacuum cannot give continuous acceleration, and it is shown that no sums of such waves can give net first order acceleration. This theorem is proven in three different ways; each method showing a different aspect of the situation

  5. LINEAR ACCELERATOR

    Science.gov (United States)

    Christofilos, N.C.; Polk, I.J.

    1959-02-17

    Improvements in linear particle accelerators are described. A drift tube system for a linear ion accelerator reduces gap capacity between adjacent drift tube ends. This is accomplished by reducing the ratio of the diameter of the drift tube to the diameter of the resonant cavity. Concentration of magnetic field intensity at the longitudinal midpoint of the external sunface of each drift tube is reduced by increasing the external drift tube diameter at the longitudinal center region.

  6. Economy in utilizing electron beam accelerators

    International Nuclear Information System (INIS)

    Takahashi, Masao

    1980-01-01

    As the typical industrialized processes using electron beam irradiation, the following items may be given: the manufacture of cables covered with cross-linking polyethylene or PVC, heat-contracting material, cross-linking polyethylene foam, etc., and the curing of coatings or surface finishes. The results of investigating economy in these processes are described. First, the running cost of electron beam irradiation equipments is calculated. The result shows that, in general, the unit cost of the equipments becomes small with increasing output, therefore the selection of large power equipments may be advantageous for economy. Other important factors concerning the equipments are the reliability and lifetime which are being improved every year and the improvement of the operational efficiency of the equipments. Next, the comparison of cost was made for each industrialized process of the cables covered with cross-linking polyethylene, polyethylene foam, and the curing of coatings. In general, the processing cost is smaller and the depreciation cost is larger in electron beam irradiation process as compared with conventional processes. In addition, since the productive capacity is larger in electron beam process it is preponderant when the amount of production is large. In the industrialized examples, unique processes or features which are not obtainable by other methods are attained. (Wakatsuki, Y.)

  7. Matrix-assisted laser desorption/ionization coupled with quadrupole/orthogonal acceleration time-of-flight mass spectrometry for protein discovery, identification, and structural analysis.

    Science.gov (United States)

    Baldwin, M A; Medzihradszky, K F; Lock, C M; Fisher, B; Settineri, T A; Burlingame, A L

    2001-04-15

    The design and operation of a novel UV-MALDI ionization source on a commercial QqoaTOF mass spectrometer (Applied Biosystem/MDS Sciex QSTAR Pulsar) is described. Samples are loaded on a 96-well target plate, the movement of which is under software control and can be readily automated. Unlike conventional high-energy MALDI-TOF, the ions are produced with low energies (5-10 eV) in a region of relatively low vacuum (8 mTorr). Thus, they are cooled by extensive low-energy collisions before selection in the quadrupole mass analyzer (Q1), potentially giving a quasi-continuous ion beam ideally suited to the oaTOF used for mass analysis of the fragment ions, although ion yields from individual laser shots may vary widely. Ion dissociation is induced by collisions with argon in an rf-only quadrupole cell, giving typical low-energy CID spectra for protonated peptide ions. Ions separated in the oaTOF are registered by a four-anode detector and time-to-digital converter and accumulated in "bins" that are 625 ps wide. Peak shapes depend upon the number of ion counts in adjacent bins. As expected, the accuracy of mass measurement is shown to be dependent upon the number of ions recorded for a particular peak. With internal calibration, mass accuracy better than 10 ppm is attainable for peaks that contain sufficient ions to give well-defined Gaussian profiles. By virtue of its high resolution, capability for accurate mass measurements, and sensitivity in the low-femotomole range, this instrument is ideally suited to protein identification for proteomic applications by generation of peptide tags, manual sequence interpretation, identification of modifications such as phosphorylation, and protein structural elucidation. Unlike the multiply charged ions typical of electrospray ionization, the singly charged MALDI-generated peptide ions show a linear dependence of optimal collision energy upon molecular mass, which is advantageous for automated operation. It is shown that the novel

  8. Electrostatic accelerators fundamentals and applications

    CERN Document Server

    2005-01-01

    Electrostatic accelerators are an important and widespread subgroup within the broad spectrum of modern, large particle acceleration devices. They are specifically designed for applications that require high-quality ion beams in terms of energy stability and emittance at comparatively low energies (a few MeV). Their ability to accelerate virtually any kind of ion over a continuously tunable range of energies make them a highly versatile tool for investigations in many research fields including, but not limited to, atomic and nuclear spectroscopy, heavy ion reactions, accelerator mass spectroscopy as well as ion-beam analysis and modification. The book is divided into three parts. The first part concisely introduces the field of accelerator technology and techniques that emphasize their major modern applications. The second part treats the electrostatic accelerator per se: its construction and operational principles as well as its maintenance. The third part covers all relevant applications in which electrosta...

  9. Improved sample utilization in thermal ionization mass spectrometry isotope ratio measurements: refined development of porous ion emitters for nuclear forensic applications

    Energy Technology Data Exchange (ETDEWEB)

    Baruzzini, Matthew Louis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-08

    The precise and accurate determination of isotopic composition in nuclear forensic samples is vital for assessing origin, intended use and process history. Thermal ionization mass spectrometry (TIMS) is widely accepted as the gold standard for high performance isotopic measurements and has long served as the workhorse in the isotopic ratio determination of nuclear materials. Nuclear forensic and safeguard specialists have relied heavily on such methods for both routine and atypical e orts. Despite widespread use, TIMS methods for the assay of actinide systems continue to be hindered by poor ionization e ciency, often less than tenths of a percent; the majority of a sample is not measured. This represents a growing challenge in addressing nextgeneration nuclear detection needs by limiting the ability to analyze ultratrace quantities of high priority elements that could potentially provide critical nuclear forensic signatures. Porous ion emitter (PIE) thermal ion sources were developed in response to the growing need for new TIMS ion source strategies for improved ionization e ciency, PIEs have proven to be simple to implement, straightforward approach to boosting ion yield. This work serves to expand the use of PIE techniques for the analysis of trace quantities of plutonium and americium. PIEs exhibited superior plutonium and americium ion yields when compared to direct lament loading and the resin bead technique, one of the most e cient methods for actinide analysis, at similar mass loading levels. Initial attempts at altering PIE composition for the analysis of plutonium proved to enhance sample utilization even further. Preliminary investigations of the instrumental fractionation behavior of plutonium and uranium analyzed via PIE methods were conducted. Data collected during these initial trial indicate that PIEs fractionate in a consistent, reproducible manner; a necessity for high precision isotope ratio measurements. Ultimately, PIEs methods were applied for

  10. Activation Measurements for Thermal Neutrons, U.S. Measurements of 36Cl in Mineral Samples from Hiroshima and Nagasaki; and Measurement of 63 Ni in Copper Samples From Hiroshima by Accelerator Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tore Straume; Alfredo A. Marchetti; Stephen D. Egbert; James A. Roberts; Ping Men; Shoichiro Fujita; Kiyoshi Shizuma; Masaharu Hoshi; G. Rugel; W. Ruhm; G. Korschinek; J. E. McAninch; K. L. Carroll; T. Faestermann; K. Knie; R. E. Martinelli; A. Wallner; C. Wallner

    2005-01-14

    The present paper presents the {sup 36}Cl measurement effort in the US. A large number of {sup 36}Cl measurements have been made in both granite and concrete samples obtained from various locations and distances in Hiroshima and Nagasaki. These measurements employed accelerator mass spectrometry (AMS) to quantify the number of atoms of {sup 36}Cl per atom of total Cl in the sample. Results from these measurements are presented here and discussed in the context of the DS02 dosimetry reevaluation effort for Hiroshima and Nagasaki atomic-bomb survivors. The production of {sup 36}Cl by bomb neutrons in mineral samples from Hiroshima and Nagasaki was primarily via the reaction {sup 35}Cl(n,{gamma}){sup 36}Cl. This reaction has a substantial thermal neutron cross-section (43.6 b at 0.025 eV) and the product has a long half-life (301,000 y). hence, it is well suited for neutron-activation detection in Hiroshima and Nagasaki using AMS more than 50 years after the bombings. A less important reaction for bomb neutrons, {sup 39}K(n,{alpha}){sup 36}Cl, typically produces less than 10% of the {sup 36}Cl in mineral samples such as granite and concrete, which contain {approx} 2% potassium. In 1988, only a year after the publication of the DS86 final report (Roesch 1987), it was demonstrated experimentally that {sup 36}Cl measured using AMS should be able to detect the thermal neutron fluences at the large distances most relevant to the A-bomb survivor dosimetry. Subsequent measurements in mineral samples from both Hiroshima and Nagasaki validated the experimental findings. The potential utility of {sup 36}Cl as a thermal neutron detector in Hiroshima was first presented by Haberstock et al. who employed the Munich AMS facility to measure {sup 36}Cl/Cl ratios in a gravestone from near the hypocenter. That work subsequently resulted in an expanded {sup 36}Cl effort in Germany that paralleled the US work. More recently, there have also been {sup 36}Cl measurements made by a Japanese

  11. Description of analytical method and clinical utility of measuring serum 7-alpha-hydroxy-4-cholesten-3-one (7aC4) by mass spectrometry.

    Science.gov (United States)

    Donato, Leslie J; Lueke, Alan; Kenyon, Stacy M; Meeusen, Jeffrey W; Camilleri, Michael

    2018-02-01

    Imbalance of bile acids (BA) homeostasis in the gastrointestinal tract can lead to chronic diarrhea or constipation when BA in the colon are in excess or low, respectively. Since both disturbances of bowel function can result from other etiologies, identifying BA imbalance is important to tailor treatment strategies. Serum concentrations of 7-alpha-hydroxy-4-cholesten-3-one (7aC4), a precursor in bile acid synthesis, reflect BA homeostasis. Here we describe a method to accurately measure serum 7aC4 and evaluate the clinical utility in patients with diarrhea or constipation phenotypes. Serum 7aC4 is measured after acetonitrile protein precipitation using C18 liquid chromatography, tandem mass spectrometry, and deuterium-labeled 7aC4 internal standard. Assay performance including linearity, precision, and accuracy was assessed using waste serum samples. The reference interval was established in healthy individuals without BA-altering conditions or medications. Clinical performance was assessed in patients with irritable bowel syndrome. The method precisely and accurately measured 7aC4 in human serum from 1.4-338ng/mL with no ion suppression or interference from related 7-keto-cholesterol. Central 95th percentile reference interval was 2.5-63.2ng/mL. Lower serum 7aC4 was found in patients with constipation with sensitivity/specificity of 79%/55% compared to healthy controls. Higher 7aC4 was found in patients with bile acid diarrhea (BAD) compared to those without BAD with sensitivity/specificity of 82%/53%. We have developed a sensitive and precise assay for measuring the concentration of 7aC4 in serum. The assay can be used to screen for diarrhea caused by bile acid malabsorption. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  12. Acceleration of microparticle

    CERN Document Server

    Shibata, H

    2002-01-01

    A microparticle (dust) ion source has been installed at the high voltage terminal of the 3.75 MV single ended Van de Graaff electrostatic accelerator and a beam line for microparticle experiments has been build at High Fluence Irradiation Facility (HIT) of Research Center for Nuclear Science and Technology, the University of Tokyo. Microparticle acceleration has been successful in obtaining expected velocities of 1-20 km/s or more for micron or submicron sized particles. Development of in situ dust detectors and analyzers on board satellites and spacecraft in the expected mass and velocity range of micrometeoroids and investigation of hypervelocity impact phenomena by using time of flight mass spectrometry, impact flash or luminescence measurement and scanning electron or laser microscope observation for metals, ceramics, polymers and semiconductors bombarded by micron-sized particles were started three years ago. (author)

  13. Workshop on Accelerator Operation (WAO 2001)

    International Nuclear Information System (INIS)

    Bailey, R.

    2001-01-01

    The 3rd Workshop on Accelerator Operation (WAO 2001) followed earlier workshops in 1996 and 1998. Most topics relevant for the efficient and effective operation of accelerators were covered. These included the tools and utilities necessary in the control rooms; the organization of accelerator operation (process monitoring, shift work, stress); the monitoring of beam quality; safety issues and standards; and questions particularly relevant for superconducting accelerators, in particular cryogenics. (author)

  14. Pelletron accelerator at Panjab University Chandigarh

    International Nuclear Information System (INIS)

    Singh, Nirmal; Mehta, Devinder

    2006-01-01

    The purpose of pelletron accelerator at Panjab University is to develop a low-energy accelerator laboratory within the university infrastructure. It will be housing a tandem electrostatic accelerator. The facility will bring together the available scientific expertise from a wide range of applications, viz. medical, biological and physical sciences and engineering that utilize accelerator-based technologies and techniques. It will play an important role in promoting integrated research and education across scientific disciplines available in the campus. (author)

  15. Expected utility without utility

    OpenAIRE

    Castagnoli, E.; Licalzi, M.

    1996-01-01

    This paper advances an interpretation of Von Neumann–Morgenstern’s expected utility model for preferences over lotteries which does not require the notion of a cardinal utility over prizes and can be phrased entirely in the language of probability. According to it, the expected utility of a lottery can be read as the probability that this lottery outperforms another given independent lottery. The implications of this interpretation for some topics and models in decision theory are considered....

  16. 14. conference on accelerators of charged particles. Annotations of reports

    International Nuclear Information System (INIS)

    1994-01-01

    Annotations of reports made at the 14 Conference on accelerators of charged particles are presented. The Conference took place 25 - 27 October, 1994 in IHEP, Protvino. Modern trends of development of cyclic and linear accelerators, as well as heavy ion accelerators and colliders have been discussed. Problems of developing accelerators on superhigh energy have been considered. Considerable attention has been paid to accelerating structures, power SHF equipment, beam monitoring systems as well as magnetic and vacuum systems of accelerators. Beam dynamics in accelerators and storage has been considered and new acceleration technique have been proposed. Utilization of accelerators for medicine and other applied purposes has been discussed

  17. Accelerator operations

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    This section is concerned with the operation of both the tandem-linac system and the Dynamitron, two accelerators that are used for entirely different research. Developmental activities associated with the tandem and the Dynamitron are also treated here, but developmental activities associated with the superconducting linac are covered separately because this work is a program of technology development in its own right

  18. CNSTN Accelerator

    International Nuclear Information System (INIS)

    Habbassi, Afifa; Trabelsi, Adel

    2010-01-01

    This project give a big idea about the measurement of the linear accelerator in the CNSTN. During this work we control dose distribution for different product. For this characterisation we have to make an installation qualification ,operational qualification,performance qualification and of course for every step we have to control temperature and the dose ,even the distribution of the last one.

  19. Accelerators course

    CERN Multimedia

    CERN. Geneva HR-RFA; Métral, E

    2006-01-01

    1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges

  20. Accelerator operations

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    Operations of the SuperHILAC, the Bevatron/Bevalac, and the 184-inch Synchrocyclotron during the period from October 1977 to September 1978 are discussed. These include ion source development, accelerator facilities, the Heavy Ion Spectrometer System, and Bevelac biomedical operations