Science.gov

Sample records for accelerator-mass spectrometer tams

  1. Development of an Accelerator Mass Spectrometer based on a Cyclotron

    SciTech Connect

    Kim, Dogyun; Bhang, Hyeongchan; Kim, Jongwon

    2011-12-13

    An accelerator mass spectrometer based on a cyclotron has been developed, and a prototype of the injection beam line has been constructed. Mass resolution of the cyclotron is designed to be over 4000. A sawtooth RF buncher in the beam line and a flat-topping RF system for the cyclotron were utilized to enhance beam transmission efficiency, which is a primary factor for improvement compared to previous cyclotron mass spectrometers. The injection beam line comprises an ion source, Einzel lens, RF buncher, 90 deg. dipole magnet and a slit box containing beam diagnostic devices. A carbon beam was measured at the location of the slit box, and beam phase spaces will be measured. The design of a cyclotron magnet was done, and orbit tracking was carried out using cyclotron optics codes. A scheme of radial injection was chosen to place a beam on the equilibrium orbit of the cyclotron. The injection scheme will be optimized after the beam measurements are completed.

  2. Development of accelerator mass spectrometer based on a compact cyclotron

    NASA Astrophysics Data System (ADS)

    Kim, J.-W.; Kim, D.-G.

    2011-07-01

    A small cyclotron has been designed for accelerator mass spectrometry, and the injection beam line is constructed as part of prototyping. Mass resolution of the cyclotron is estimated to be around 4000. The design of the cyclotron was performed with orbit-tracking computations using 3D magnetic and electric fields, and beam optics of the injection line was calculated using the codes such as IGUN and TRANSPORT. The radial injection scheme is chosen to place a beam on equilibrium orbit of the cyclotron. The injection line includes an ion source, Einzel lens, rf buncher, 90° dipole magnet, and quadrupole triplet magnet. A carbon beam was extracted from the front part of the injection line. An rf cavity system for the cyclotron was built and tested. A multi channel plates (MCP) detector to measure low-current ion beams was also tested. Design considerations are given to analyzing a few different radioisotopes in form of positive ions as well as negative ions.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Astrophysics Data System (ADS)

    Wilcken, K. M.; Freeman, S. P. H. T.; Xu, S.; Dougans, A.

    2013-01-01

    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 14C AMS of either polarity ions is limited by an interference. In the case of anion acceleration we have newly determined this to be summed 13C and 16O by improvising an additional Wien filter on our SSAMS deck. Also, 14C 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 14N 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.

  5. Accelerator-mass spectrometer (AMS) radiocarbon dating of Pleistocene lake sediments in the Great Basin

    USGS Publications Warehouse

    Thompson, R.S.; Toolin, L.J.; Forester, R.M.; Spencer, R.J.

    1990-01-01

    Pleistocene lake sediments in the Great Basin typically contain little organic carbon, and thus are difficult to date reliably by conventional radioccarbon methods. Paleoenvironmental data are abundant in these sediments, but are of limited value without adequate age controls. With the advent of accelerator-mass spectrometer (AMS) radiocarbon dating, it is now possible to date these paleolacustrine sediments. AMS dates were obtained on sediment cores from the Bonneville, Franklin, and Lahontan Basins. In the Bonneville Basin, the AMS-based chronology compares well with other chronologies constructed from dated shore-zone features. In the Bonneville and Franklin basins, AMS dates delimit unconformities not apparent by other means. We found that dispersed organic carbon from sediments deposited during relatively freshwater intervals provided apparently reliable AMS radiocarbon dates. Carbonate microfossils from the Lahontan Basin also produced results that appear reasonable, while bulk carbonate yielded erroneous results. ?? 1990.

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

    NASA Astrophysics Data System (ADS)

    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.

  7. A new LabVIEW-based control system for the Naval Research Laboratory Trace Element Accelerator Mass Spectrometer

    SciTech Connect

    DeTurck, T. M.; Treacy, D. J. Jr.; Knies, D. L.; Grabowski, K. S.; Knoll, C.; Kennedy, C. A.; Hubler, G. K.

    1999-06-10

    A new LabVIEW-based control system for the existing tandem accelerator and new AMS components has been implemented at the Trace Element Accelerator Mass Spectrometry (TEAMS) facility at the Naval Research Laboratory. Through the use of Device Interfaces (DIs) distributed along a fiber optic network, virtually every component of the accelerator system can be controlled from any networked computer terminal as well as remotely via modem or the internet. This paper discusses the LabVIEW-based control software, including remote operation, automatic calculation of ion optical component parameters, beam optimization, and data logging and retrieval.

  8. Biomedical accelerator mass spectrometry

    NASA Astrophysics Data System (ADS)

    Freeman, Stewart P. H. T.; Vogel, John S.

    1995-05-01

    Ultrasensitive SIMS with accelerator based spectrometers has recently begun to be applied to biomedical problems. Certain very long-lived radioisotopes of very low natural abundances can be used to trace metabolism at environmental dose levels ( [greater-or-equal, slanted] z mol in mg samples). 14C in particular can be employed to label a myriad of compounds. Competing technologies typically require super environmental doses that can perturb the system under investigation, followed by uncertain extrapolation to the low dose regime. 41Ca and 26Al are also used as elemental tracers. Given the sensitivity of the accelerator method, care must be taken to avoid contamination of the mass spectrometer and the apparatus employed in prior sample handling including chemical separation. This infant field comprises the efforts of a dozen accelerator laboratories. The Center for Accelerator Mass Spectrometry has been particularly active. In addition to collaborating with groups further afield, we are researching the kinematics and binding of genotoxins in-house, and we support innovative uses of our capability in the disciplines of chemistry, pharmacology, nutrition and physiology within the University of California. The field can be expected to grow further given the numerous potential applications and the efforts of several groups and companies to integrate more the accelerator technology into biomedical research programs; the development of miniaturized accelerator systems and ion sources capable of interfacing to conventional HPLC and GMC, etc. apparatus for complementary chemical analysis is anticipated for biomedical laboratories.

  9. Measuring transfer of 14C-PCB from maternal diet to milk in a goat model using an accelerator mass spectrometer (AMS)

    NASA Astrophysics Data System (ADS)

    Janle, E.; Sojka, J.; Jackson, G. S.; Lachcik, P.; Einstien, J. A.; Santerre, C. R.

    2007-06-01

    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 14C can be measured using Accelerator Mass Spectrometry (AMS), a goat model was used to establish a minimum oral dose of 14C-labeled PCB (2,2‧,4,4‧,5,5‧-hexachlorobiphenyl-UL-14C) 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 14C 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.

  10. Accelerator Mass Spectrometry (AMS) 1977-1987

    NASA Astrophysics Data System (ADS)

    Gove, H. E.; Purser, K. H.; Litherland, A. E.

    2010-04-01

    The eleventh Accelerator Mass Spectrometry (AMS 11) Conference took place in September 2008, the Thirtieth Anniversary of the first Conference. That occurred in 1978 after discoveries with nuclear physics accelerators in 1977. Since the first Conference there have now been ten further conferences on the development and applications of what has become known as AMS. This is the accepted acronym for the use of accelerators, together with nuclear and atomic physics techniques, to enhance the performance of mass spectrometers for the detection and measurement of rare long-lived radioactive elements such as radiocarbon. This paper gives an outline of the events that led to the first conference together with a brief account of the first four conferences before the introduction of the second generation of accelerator mass spectrometers at AMS 5.

  11. Accelerator mass spectrometry

    SciTech Connect

    Vogel, J.S.; Turteltaub, K.W.; Finkel, R.; Nelson, D.E.

    1995-06-01

    Accelerator mass spectroscopy (AMS) can be used for efficient detection of long-lived isotopes at part-per-quadrillion sensitivities with good precision. In this article we present an overview of AMS and its recent use in archaeology, geochemistry and biomolecular tracing. All AMS systems use cesium sputter ion sources to produce negative ions from a small button of a solid sample containing the element of interest, such as graphite, metal halide, or metal oxide, often mixed with a metal powder as binder and thermal conductor. Experience shows that both natural and biomedical samples are compatible in a single AMS system, but few other AMS sites make routine {sup 14}C measurements for both dating and tracing. AMS is, in one sense, just `a very sensitive decay counter`, but if AMS sensitivity is creatively coupled to analytical chemistry of certain isotopes, whole new areas of geosciences, archaeology, and life sciences can be explored. 29 refs., 2 figs., 1 tab.

  12. Accelerator mass spectrometry.

    PubMed

    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.

  13. Symposium on accelerator mass spectrometry

    SciTech Connect

    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.

  14. High-acceleration mass drivers

    NASA Technical Reports Server (NTRS)

    Oneill, G. K.; Kolm, H. H.

    1979-01-01

    High-acceleration mass drivers are discussed including the MD2 model of axial geometry, with individually powered drive coils of 13.1 cm diameter. Timing is derived through the interruption of light beams by the moving armature (bucket). Electric power is provided by the resonant discharge of sector capacitor banks through silicon-controlled rectifiers in a two-phase, quadrature circuit. The bucket flies in vacuum, guided by passive dynamic eddy-current magnetic forces, those currents flowing in strip conductors lining the inside of a nonconducting vacuum pipe. Quantitative measurements are obtained with a solid bucket carrying two superconducting coils with a current density of 25 kA/sq cm. A cryogenic station for cooling the bucket to liquid helium temperature is connected to the vacuum pipe.

  15. Neuroscience and Accelerator Mass Spectrometry

    SciTech Connect

    Palmblad, M N; Buchholz, B A; Hillegonds, D J; Vogel, J S

    2004-08-02

    Accelerator mass spectrometry (AMS) is a mass spectrometric method for quantifying rare isotopes. It has had great impact in geochronology and archaeology and is now being applied in biomedicine. AMS measures radioisotopes such as {sup 3}H, {sup 14}C, {sup 26}Al, {sup 36}Cl and {sup 41}Ca, with zepto- or attomole sensitivity and high precision and throughput, enabling safe human pharmacokinetic studies involving: microgram doses, agents having low bioavailability, or toxicology studies where administered doses must be kept low (<1 {micro}g/kg). It is used to study long-term pharmacokinetics, to identify biomolecular interactions, to determine chronic and low-dose effects or molecular targets of neurotoxic substances, to quantify transport across the blood-brain barrier and to resolve molecular turnover rates in the human brain on the timescale of decades. We will here review how AMS is applied in neurotoxicology and neuroscience.

  16. Registration of TAM401 wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    'TAM 401', a hard red winter wheat (Triticum aestivum L) cultivar (PI658500) with experimental designation TX03M1096, was developed and released by Texas AgriLife Research in 2008. TAM 401 is an F4 derived line from the cross 'Mason' (PI 594044)/'Jagger' (PI593688). TAM 401 is an early maturing apic...

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

    SciTech Connect

    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.

  18. Registration of 'TAM 113' wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    TAM 113’ (Reg. No. CV-1081, PI 666125), a hard red winter wheat (Triticum aestivum L.) cultivar with experimental designation TX02A0252, was developed and released by Texas AgriLife Research in 2010. TAM 113 is an F5–derived line from the cross TX90V6313/TX94V3724 made at Vernon, TX in 1995. Both T...

  19. Radionuclide measurements by accelerator mass spectrometry at Arizona

    NASA Technical Reports Server (NTRS)

    Jull, A. J. T.; Donahue, D. J.; Zabel, T. H.

    1986-01-01

    Over the past years, Tandem Accelerator Mass Spectrometry (TAMS) has become established as an important method for radionuclide analysis. In the Arizona system the accelerator is operated at a thermal voltage of 1.8MV for C-14 analysis, and 1.6 to 2MV for Be-10. Samples are inserted into a cesium sputter ion source in solid form. Negative ions sputtered from the target are accelerated to about 25kV, and the injection magnet selects ions of a particular mass. Ions of the 3+ charge state, having an energy of about 9MeV are selected by an electrostatic deflector, surviving ions pass through two magnets, where only ions of the desired mass-energy product are selected. The final detector is a combination ionization chamber to measure energy loss (and hence, Z), and a silicon surface-barrier detector which measures residual energy. After counting the trace iosotope for a fixed time, the injected ions are switched to the major isotope used for normalization. These ions are deflected into a Faraday cup after the first high-energy magnet. Repeated measurements of the isotope ratio of both sample and standards results in a measurement of the concentration of the radionuclide. Recent improvements in sample preparation for C-14 make preparation of high-beam current graphite targets directly from CO2 feasible. Except for some measurements of standards and backgrounds for Be-10 measurements to date have been on C-14. Although most results have been in archaeology and quaternary geology, studies have been expanded to include cosmogenic C-14 in meteorites. The data obtained so far tend to confirm the antiquity of Antarctic meteorites from the Allan Hills site. Data on three samples of Yamato meteorites gave terrestrial ages of between about 3 and 22 thousand years.

  20. Plutonium measurements by accelerator mass spectrometry at LLNL

    SciTech Connect

    McAninch, J E; Hamilton, T F; Broan, T A; Jokela, T A; Knezovich, T J; Ognibene, T J; Proctor, I D; Roberts, M L; Southon, J R; Vogel, J S; Sideras-Haddad, E

    1999-10-26

    Mass spectrometric methods provide sensitive, routine, and cost-effective analyses of long-lived radionuclides. Here the authors report on the status of work at Lawrence Livermore National Laboratory (LLNL) to develop a capability for actinide measurements by accelerator mass spectrometry (AMS) to take advantage of the high potential of AMS for rejection of interferences. This work demonstrates that the LLNL AMS spectrometer is well-suited for providing high sensitivity, robust, high throughput measurements of plutonium concentrations and isotope ratios. Present backgrounds are {approximately}2 x 10{sup 7}atoms per sample for environmental samples prepared using standard alpha spectrometry protocols. Recent measurements of {sup 239+240}Pu and {sup 241}Pu activities and {sup 240}Pu/{sup 239}Pu isotope ratios in IAEA reference materials agree well with IAEA reference values and with alpha spectrometry and recently published ICP-MS results. Ongoing upgrades of the AMS spectrometer are expected to reduce backgrounds below 1 x 10{sup 6} atoms per sample while allowing simplifications of the sample preparation chemistry. These simplifications will lead to lower per-sample costs, higher throughput, faster turn around and, ultimately, to larger and more robust data sets.

  1. Accelerator mass spectrometry: Proceedings of the fourth international symposium on accelerator mass spectrometry

    SciTech Connect

    Gove, H.E.; Litherland, A.E.; Elmore, D.

    1987-01-01

    This report is a volume of the journal Nuclear Instruments and Methods in Physics Research B: Beam Interactions with Materials and Atoms. This particular volume is concerned with accelerator mass spectrometry. The sections of this issue are: Advances in AMS techniques; Archaeology and ecology; Glaciology and climatology; Cosmochemistry and in situ production; Ocean and atmospheric sciences; Hydrology and geology; Astrophysics, nuclear physics and lasers.

  2. Accelerator Mass Spectroscopy and the Ice Man

    NASA Astrophysics Data System (ADS)

    Kutschera, Walter

    2003-10-01

    The main use of Accelerator Mass Spectrometry (AMS) is for 14C dating, which is arguably the most important application of any radionuclide. AMS has revolutionized the field by measuring 14C through isotope ratios rather than the classical method of beta counting. This increased the sensitivity of 14C detection almost one million times, allowing one to reduce sample sizes from several grams required for beta counting to milligram amounts and below for AMS. In addition, measuring times are reduced from several days to about one hour or less. This then allows one to perform 14C measurements which were impossible with the beta counting technique. A good example is the famous Iceman Oetzi, a well-preserved 5200-year old body which emerged from a thawing icefield in the central European Alps in 1991. In this talk, a summary of the current understanding of this unique archaeological find will be presented, with particular emphasis on 14C measurements.

  3. Diversification of TAM receptor function

    PubMed Central

    Zagórska, Anna; Través, Paqui G.; Lew, Erin D.; Dransfield, Ian; Lemke, Greg

    2014-01-01

    Apoptotic cell clearance is critical for both tissue homeostasis and the resolution of inflammation. We found that the TAM receptor tyrosine kinases Axl and Mer played distinct roles as phagocytic receptors in these two settings, where they exhibited divergent expression, regulation, and activity. Mer acted as a tolerogenic receptor in resting macrophages and in settings of immune suppression. Conversely, Axl was an inflammatory response receptor whose expression was induced by pro-inflammatory stimuli. Axl and Mer displayed distinct ligand specificities, ligand-receptor complex formation in tissues, and receptor shedding upon activation. These differences notwithstanding, phagocytosis by either protein was strictly dependent on receptor activation that was triggered by bridging TAM receptor–ligand complexes to the ‘eat-me’ signal phosphatidylserine on apoptotic cell surfaces. PMID:25194421

  4. Accelerator Mass Spectrometry in Laboratory Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Nusair, O.; Bauder, W.; Gyürky, G.; Paul, M.; Collon, P.; Fülöp, Zs; Greene, J.; Kinoshita, N.; Palchan, T.; Pardo, R.; Rehm, K. E.; Scott, R.; Vondrasek, R.

    2016-01-01

    The extreme sensitivity and discrimination power of accelerator mass spectrometry (AMS) allows for the search and the detection of rare nuclides either in natural samples or produced in the laboratory. At Argonne National Laboratory, we are developing an AMS setup aimed in particular at the detection of medium and heavy nuclides, relying on the high ion energy achievable with the ATLAS superconducting linear accelerator and on gas-filled magnet isobaric separation. The setup was recently used for the detection of the 146Sm p-process nuclide and for a new determination of the 146Sm half-life (68.7 My). AMS plays an important role in the measurement of stellar nuclear reaction cross sections by the activation method, extending thus the technique to the study of production of long-lived radionuclides. Preliminary measurements of the 147Sm(γ,n)146Sm are described. A measurement of the 142Nd(α,γ)146Sm and 142Nd(α,n)145Sm reactions is in preparation. A new laser-ablation method for the feeding of the Electron Cyclotron Resonance (ECR) ion source is described.

  5. Accelerator mass spectrometry of molecular ions

    NASA Astrophysics Data System (ADS)

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

    2005-10-01

    The use of tandem accelerators for accelerator mass spectrometry (AMS) allows to literally "analyze" molecules. When a molecular ion with mass M and charge Q is injected at the low-energy side, it is efficiently broken up into its atomic constituents during the stripping process in the terminal. At the high-energy side the positively charged atomic ions are again analyzed by their mass-to-charge ratio and by their energy in the detector (and eventually by their nuclear charge, too). We show the usefulness of the AMS method by identifying unambiguously the doubly-charged negative molecule (43Ca19F4)2- for the first time. It considerably eases the task that the total mass M = 119 is odd, so the di-anion is injected at the half-integer mass-to-charge ratio M/Q = 59.5, where no singly charged ions can interfere. The full power of AMS is needed when we try to proof the existence of di-anions with an integer M/Q, e.g. (23Na35Cl3)2-, whose stability is of interest for atomic physics theory.

  6. Small system for tritium accelerator mass spectrometry

    DOEpatents

    Roberts, M.L.; Davis, J.C.

    1993-02-23

    Apparatus for ionizing and accelerating a sample containing isotopes of hydrogen and detecting the ratios of hydrogen isotopes contained in the sample is disclosed. An ion source generates a substantially linear ion beam including ions of tritium from the sample. A radio-frequency quadrupole accelerator is directly coupled to and axially aligned with the source at an angle of substantially zero degrees. The accelerator accelerates species of the sample having different mass to different energy levels along the same axis as the ion beam. A spectrometer is used to detect the concentration of tritium ions in the sample. In one form of the invention, an energy loss spectrometer is used which includes a foil to block the passage of hydrogen, deuterium and [sup 3]He ions, and a surface barrier or scintillation detector to detect the concentration of tritium ions. In another form of the invention, a combined momentum/energy loss spectrometer is used which includes a magnet to separate the ion beams, with Faraday cups to measure the hydrogen and deuterium and a surface barrier or scintillation detector for the tritium ions.

  7. Small system for tritium accelerator mass spectrometry

    DOEpatents

    Roberts, Mark L.; Davis, Jay C.

    1993-01-01

    Apparatus for ionizing and accelerating a sample containing isotopes of hydrogen and detecting the ratios of hydrogen isotopes contained in the sample is disclosed. An ion source generates a substantially linear ion beam including ions of tritium from the sample. A radio-frequency quadrupole accelerator is directly coupled to and axially aligned with the source at an angle of substantially zero degrees. The accelerator accelerates species of the sample having different mass to different energy levels along the same axis as the ion beam. A spectrometer is used to detect the concentration of tritium ions in the sample. In one form of the invention, an energy loss spectrometer is used which includes a foil to block the passage of hydrogen, deuterium and .sup.3 He ions, and a surface barrier or scintillation detector to detect the concentration of tritium ions. In another form of the invention, a combined momentum/energy loss spectrometer is used which includes a magnet to separate the ion beams, with Faraday cups to measure the hydrogen and deuterium and a surface barrier or scintillation detector for the tritium ions.

  8. TAM Receptor Signaling in Immune Homeostasis

    PubMed Central

    Rothlin, Carla V.; Carrera-Silva, Eugenio A.; Bosurgi, Lidia; Ghosh, Sourav

    2015-01-01

    The TAM receptor tyrosine kinases (RTKs)—TYRO3, AXL, and MERTK—together with their cognate agonists GAS6 and PROS1 play an essential role in the resolution of inflammation. Deficiencies in TAM signaling have been associated with chronic inflammatory and autoimmune diseases. Three processes regulated by TAM signaling may contribute, either independently or collectively, to immune homeostasis: the negative regulation of the innate immune response, the phagocytosis of apoptotic cells, and the restoration of vascular integrity. Recent studies have also revealed the function of TAMs in infectious diseases and cancer. Here, we review the important milestones in the discovery of these RTKs and their ligands and the studies that underscore the functional importance of this signaling pathway in physiological immune settings and disease. PMID:25594431

  9. Determination of cosmogenic Ca-41 in a meteorite with tandem accelerator mass spectrometry

    NASA Technical Reports Server (NTRS)

    Kubik, P. W.; Elmore, D.; Conard, N. J.; Nishiizumi, K.; Arnold, J. R.

    1986-01-01

    The first use of tandem accelerator mass spectrometry (TAMS) to measure the content of Ca-41 in a natural sample, the iron Bogou meteorite, is reported. Ca in the samples was extracted by hydroxide precipitation and purified by means of a caution exchange resin (AG 50W-X8). After adding 4 percent ammonium oxide, the precipitate was ignited to CaO in a quartz vial at about 1100 C. The Ca-41/Ca ratios were determined following acceleration by alternate measurements of the Ca-40 beam current in an image Faraday cup. Ca-41 particles were also measured using a gas counter. The measured Ca-41/Ca ratio was 3.8 + or -0.6 x 10 to the 12th, which corresponds to a Ca-41 activity of 6.9 + or -1.1 d.p.m. per kg. Calculation of the half-life of Ca-41 in the Bogou meteorite yielded an age of 103,000 years.

  10. Differential TAM receptor–ligand–phospholipid interactions delimit differential TAM bioactivities

    PubMed Central

    Lew, Erin D; Oh, Jennifer; Burrola, Patrick G; Lax, Irit; Zagórska, Anna; Través, Paqui G; Schlessinger, Joseph; Lemke, Greg

    2014-01-01

    The TAM receptor tyrosine kinases Tyro3, Axl, and Mer regulate key features of cellular physiology, yet the differential activities of the TAM ligands Gas6 and Protein S are poorly understood. We have used biochemical and genetic analyses to delineate the rules for TAM receptor–ligand engagement and find that the TAMs segregate into two groups based on ligand specificity, regulation by phosphatidylserine, and function. Tyro3 and Mer are activated by both ligands but only Gas6 activates Axl. Optimal TAM signaling requires coincident TAM ligand engagement of both its receptor and the phospholipid phosphatidylserine (PtdSer): Gas6 lacking its PtdSer-binding ‘Gla domain’ is significantly weakened as a Tyro3/Mer agonist and is inert as an Axl agonist, even though it binds to Axl with wild-type affinity. In two settings of TAM-dependent homeostatic phagocytosis, Mer plays a predominant role while Axl is dispensable, and activation of Mer by Protein S is sufficient to drive phagocytosis. DOI: http://dx.doi.org/10.7554/eLife.03385.001 PMID:25265470

  11. Determination of 135Cs by accelerator mass spectrometry

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

    The ratio of anthropogenic 135Cs and 137Cs isotopes is characteristic of a uranium fission source. This research evaluates the technique of isotope dilution (yield tracing) for the purpose of quantifying 135Cs by accelerator mass spectrometry with on-line isobar separation. Interferences from Ba, Zn2, 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 135Cs 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.

  12. Detection of 36Cl with accelerator mass spectrometry

    NASA Astrophysics Data System (ADS)

    Jiang, Songsheng; Ma, Tiejung; Jiang, Shan; Yang, Bingfan; Wang, Xun; Huang, Qi

    1989-12-01

    An accelerator mass spectrometry (AMS) system based on the HI-13 tandem accelerator at the Institute of Atomic Energy (IAE) is described, and the first detection of 36Cl with our AMS system is reported. The electrostatic deflector completely rejects isotopic background, 35Cl and 37Cl. The ioinzation chamber distinguishs 36Cl from isobaric background, 36S. The measurement of 36Cl with two samples is presented.

  13. Accelerator mass spectrometry for quantitative in vivo tracing

    SciTech Connect

    Vogel, J S

    2005-04-19

    Accelerator mass spectrometry (AMS) counts individual rare, usually radio-, isotopes such as radiocarbon at high efficiency and specificity in milligram-sized samples. AMS traces very low chemical doses ({micro}g) and radiative doses (100 Bq) of isotope labeled compounds in animal models and directly in humans for pharmaceutical, nutritional, or toxicological research. Absorption, metabolism, distribution, binding, and elimination are all quantifiable with high precision after appropriate sample definition.

  14. Accelerator mass spectrometry as a bioanalytical tool for nutritional research

    SciTech Connect

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

    1997-09-01

    Accelerator Mass Spectrometry is a mass spectrometric method of detecting long-lived radioisotopes without regard to their decay products or half-life. The technique is normally applied to geochronology, but recently has been developed for bioanalytical tracing. AMS detects isotope concentrations to parts per quadrillion, quantifying labeled biochemicals to attomole levels in milligram- sized samples. Its advantages over non-isotopeic and stable isotope labeling methods are reviewed and examples of analytical integrity, sensitivity, specificity, and applicability are provided.

  15. The LLNL Accelerator Mass Spectrometry System for Biochemical 14C-Measurements

    SciTech Connect

    Ognibene, T J; Bench, G; Brown, T A; Vogel, J S

    2002-10-31

    We report on recent improvements made to our 1 MV accelerator mass spectrometry system that is dedicated to {sup 14}C quantification of biochemical samples. Increased vacuum pumping capacity near the high voltage terminal has resulted in a 2-fold reduction of system backgrounds to 0.04 amol {sup 14}C/mg carbon. Carbon ion transmission through the accelerator has also improved a few percent. We have also developed tritium measurement capability on this spectrometer. The {sup 3}H/{sup 1}H isotopic ratio of a milligram-sized processed tap water sample has been measured at 4 {+-} 1 x 10{sup -16} (430 {+-} 110 {micro}Bq/mg H). Measurement throughput for a typical biochemical {sup 3}H sample is estimated to be {approx}10 minutes/sample.

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

    PubMed

    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.

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

    PubMed Central

    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

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

    PubMed

    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. PMID:17740475

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

    PubMed

    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.

  20. Technetium measurements by accelerator mass spectrometry at LLNL

    NASA Astrophysics Data System (ADS)

    Bergquist, B. A.; Marchetti, A. A.; Martinelli, R. E.; McAninch, J. E.; Nimz, G. J.; Proctor, I. D.; Southon, J. R.; Vogel, J. S.

    2000-10-01

    Technetium-99 is a long-lived, high-abundance fission product which has been widely distributed in the environment through atmospheric testing, the nuclear fuel cycle, and nuclear medicine. It has a high potential for migration in the environment as the pertechnetate anion. At the Center for Accelerator Mass Spectrometry, methods are being developed for the detection of this radionuclide by accelerator mass spectrometry (AMS), including extraction from environmental samples, concentration and purification of the 99Tc, conversion to a form appropriate for AMS analysis, and quantification by AMS. Besides interference from the stable (though relatively rare) atomic isobar 99Ru, the detection of 99Tc by AMS presents some technical challenges which are not present for the other radionuclides typically measured by AMS. These challenges are related to the lack of a stable Tc isotope. Here we present the status of our 99Tc methods including discussion of interferences and sensitivity, and recent results for environmental samples and the IAEA reference material IAEA-381, Irish Sea Water. Sensitivity is presently ˜10 μBq (˜1×10 8 atoms) per sample, limited primarily by 99Ru introduced from process chemicals, and precision/reproducibility is ˜15-25%.

  1. Physiology and transcriptomics of water-deficit stress responses in wheat cultivars TAM 111 and TAM 112.

    PubMed

    Reddy, Srirama Krishna; Liu, Shuyu; Rudd, Jackie C; Xue, Qingwu; Payton, Paxton; Finlayson, Scott A; Mahan, James; Akhunova, Alina; Holalu, Srinidhi V; Lu, Nanyan

    2014-09-01

    Hard red winter wheat crops on the U.S. Southern Great Plains often experience moderate to severe drought stress, especially during the grain filling stage, resulting in significant yield losses. Cultivars TAM 111 and TAM 112 are widely cultivated in the region, share parentage and showed superior but distinct adaption mechanisms under water-deficit (WD) conditions. Nevertheless, the physiological and molecular basis of their adaptation remains unknown. A greenhouse study was conducted to understand the differences in the physiological and transcriptomic responses of TAM 111 and TAM 112 to WD stress. Whole-plant data indicated that TAM 112 used more water, produced more biomass and grain yield under WD compared to TAM 111. Leaf-level data at the grain filling stage indicated that TAM 112 had elevated abscisic acid (ABA) content and reduced stomatal conductance and photosynthesis as compared to TAM 111. Sustained WD during the grain filling stage also resulted in greater flag leaf transcriptome changes in TAM 112 than TAM 111. Transcripts associated with photosynthesis, carbohydrate metabolism, phytohormone metabolism, and other dehydration responses were uniquely regulated between cultivars. These results suggested a differential role for ABA in regulating physiological and transcriptomic changes associated with WD stress and potential involvement in the superior adaptation and yield of TAM 112. PMID:25014264

  2. Physiology and transcriptomics of water-deficit stress responses in wheat cultivars TAM 111 and TAM 112.

    PubMed

    Reddy, Srirama Krishna; Liu, Shuyu; Rudd, Jackie C; Xue, Qingwu; Payton, Paxton; Finlayson, Scott A; Mahan, James; Akhunova, Alina; Holalu, Srinidhi V; Lu, Nanyan

    2014-09-01

    Hard red winter wheat crops on the U.S. Southern Great Plains often experience moderate to severe drought stress, especially during the grain filling stage, resulting in significant yield losses. Cultivars TAM 111 and TAM 112 are widely cultivated in the region, share parentage and showed superior but distinct adaption mechanisms under water-deficit (WD) conditions. Nevertheless, the physiological and molecular basis of their adaptation remains unknown. A greenhouse study was conducted to understand the differences in the physiological and transcriptomic responses of TAM 111 and TAM 112 to WD stress. Whole-plant data indicated that TAM 112 used more water, produced more biomass and grain yield under WD compared to TAM 111. Leaf-level data at the grain filling stage indicated that TAM 112 had elevated abscisic acid (ABA) content and reduced stomatal conductance and photosynthesis as compared to TAM 111. Sustained WD during the grain filling stage also resulted in greater flag leaf transcriptome changes in TAM 112 than TAM 111. Transcripts associated with photosynthesis, carbohydrate metabolism, phytohormone metabolism, and other dehydration responses were uniquely regulated between cultivars. These results suggested a differential role for ABA in regulating physiological and transcriptomic changes associated with WD stress and potential involvement in the superior adaptation and yield of TAM 112.

  3. Attomole quantitation of protein separations with accelerator mass spectrometry

    SciTech Connect

    Vogel, J S; Grant, P G; Buccholz, B A; Dingley, K; Turteltaub, K W

    2000-12-15

    Quantification of specific proteins depends on separation by chromatography or electrophoresis followed by chemical detection schemes such as staining and fluorophore adhesion. Chemical exchange of short-lived isotopes, particularly sulfur, is also prevalent despite the inconveniences of counting radioactivity. Physical methods based on isotopic and elemental analyses offer highly sensitive protein quantitation that has linear response over wide dynamic ranges and is independent of protein conformation. Accelerator mass spectrometry quantifies long-lived isotopes such as 14C to sub-attomole sensitivity. We quantified protein interactions with small molecules such as toxins, vitamins, and natural biochemicals at precisions of 1-5% . Micro-proton-induced-xray-emission quantifies elemental abundances in separated metalloprotein samples to nanogram amounts and is capable of quantifying phosphorylated loci in gels. Accelerator-based quantitation is a possible tool for quantifying the genome translation into proteome.

  4. Low-level 14C measurements and Accelerator Mass Spectrometry

    SciTech Connect

    Litherland, A.E.; Beukens, R.P.; Zhao, X.-L.; Kieser, W.E.; Gove, H.E.

    2005-09-08

    Accelerator Mass Spectrometry (AMS) and isotope enrichment were used in 1991 to estimate that the 14C content of methane in natural gas was {<=}1.6x10-18 of the total carbon. The low content of 14C in underground hydrocarbons was verified later in the remarkable results from the Borexino test scintillation counter for solar neutrino studies. Since then studies of the 14C background problem have demonstrated that much of the background originally observed in the AMS measurements can, in principle, be eliminated. However, many difficulties and other backgrounds are to be faced as the limit for AMS is pushed still further towards possibly a ratio of < 10-21. These will be discussed.

  5. Dating Studies of Elephant Tusks Using Accelerator Mass Spectrometry

    SciTech Connect

    Sideras-Haddad, E; Brown, T A

    2002-10-03

    A new method for determining the year of birth, the year of death, and hence, the age at death, of post-bomb and recently deceased elephants has been developed. The technique is based on Accelerator Mass Spectrometry radiocarbon analyses of small-sized samples extracted from along the length of a ge-line of an elephant tusk. The measured radiocarbon concentrations in the samples from a tusk can be compared to the {sup 14}C atmospheric bomb-pulse curve to derive the growth years of the initial and final samples from the tusk. Initial data from the application of this method to two tusks will be presented. Potentially, the method may play a significant role in wildlife management practices of African national parks. Additionally, the method may contribute to the underpinnings of efforts to define new international trade regulations, which could, in effect, decrease poaching and the killing of very young animals.

  6. Improved Actinide Neutron Capture Cross Sections Using Accelerator Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Bauder, W.; Pardo, R. C.; Kondev, F. G.; Kondrashev, S.; Nair, C.; Nusair, O.; Palchan, T.; Scott, R.; Seweryniak, D.; Vondrasek, R.; Collon, P.; Paul, M.; Youinou, G.; Salvatores, M.; Palmotti, G.; Berg, J.; Maddock, T.; Imel, G.

    2014-09-01

    The MANTRA (Measurement of Actinide Neutron TRAnsmutations) project will improve energy-integrated neutron capture cross section data across the actinide region. These data are incorporated into nuclear reactor models and are an important piece in understanding Generation IV reactor designs. We will infer the capture cross sections by measuring isotopic ratios from actinide samples, irradiated in the Advanced Test Reactor at INL, with Accelerator Mass Spectrometry (AMS) at ATLAS (ANL). The superior sensitivity of AMS allows us to extract multiple cross sections from a single sample. In order to analyze the large number of samples needed for MANTRA and to meet the goal of extracting multiple cross sections per sample, we have made a number of modifications to the AMS setup at ATLAS. In particular, we are developing a technique to inject solid material into the ECR with laser ablation. With laser ablation, we can better control material injection and potentially increase efficiency in the ECR, thus creating less contamination in the source and reducing cross talk. I will present work on the laser ablation system and preliminary results from our AMS measurements. The MANTRA (Measurement of Actinide Neutron TRAnsmutations) project will improve energy-integrated neutron capture cross section data across the actinide region. These data are incorporated into nuclear reactor models and are an important piece in understanding Generation IV reactor designs. We will infer the capture cross sections by measuring isotopic ratios from actinide samples, irradiated in the Advanced Test Reactor at INL, with Accelerator Mass Spectrometry (AMS) at ATLAS (ANL). The superior sensitivity of AMS allows us to extract multiple cross sections from a single sample. In order to analyze the large number of samples needed for MANTRA and to meet the goal of extracting multiple cross sections per sample, we have made a number of modifications to the AMS setup at ATLAS. In particular, we are

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

    PubMed

    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.

  8. Recent advances in biomedical applications of accelerator mass spectrometry

    PubMed Central

    Hah, Sang Soo

    2009-01-01

    The use of radioisotopes has a long history in biomedical science, and the technique of accelerator mass spectrometry (AMS), an extremely sensitive nuclear physics technique for detection of very low-abundant, stable and long-lived isotopes, has now revolutionized high-sensitivity isotope detection in biomedical research, because it allows the direct determination of the amount of isotope in a sample rather than measuring its decay, and thus the quantitative analysis of the fate of the radiolabeled probes under the given conditions. Since AMS was first used in the early 90's for the analysis of biological samples containing enriched 14C for toxicology and cancer research, the biomedical applications of AMS to date range from in vitro to in vivo studies, including the studies of 1) toxicant and drug metabolism, 2) neuroscience, 3) pharmacokinetics, and 4) nutrition and metabolism of endogenous molecules such as vitamins. In addition, a new drug development concept that relies on the ultrasensitivity of AMS, known as human microdosing, is being used to obtain early human metabolism information of candidate drugs. These various aspects of AMS are reviewed and a perspective on future applications of AMS to biomedical research is provided. PMID:19534792

  9. Improving tritium exposure reconstructions using accelerator mass spectrometry

    PubMed Central

    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

  10. Improving Tritium Exposure Reconstructions Using Accelerator Mass Spectrometry

    SciTech Connect

    Love, A; Hunt, J; Knezovich, J

    2003-06-01

    Exposure reconstructions for radionuclides are inherently difficult. As a result, most reconstructions are based primarily on mathematical models of environmental fate and transport. These models can have large uncertainties, as important site-specific information is unknown, missing, or crudely estimated. Alternatively, surrogate environmental measurements of exposure can be used for site-specific reconstructions. In cases where environmental transport processes are complex, well-chosen environmental surrogates can have smaller exposure uncertainty than mathematical models. Because existing methodologies have significant limitations, the development or improvement of methodologies for reconstructing exposure from environmental measurements would provide important additional tools in assessing the health effects of chronic exposure. As an example, the direct measurement of tritium atoms by accelerator mass spectrometry (AMS) enables rapid low-activity tritium measurements from milligram-sized samples, which permit greater ease of sample collection, faster throughput, and increased spatial and/or temporal resolution. Tritium AMS was 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.

  11. FemtoMolar measurements using accelerator mass spectrometry.

    PubMed

    Salehpour, Mehran; Forsgard, Niklas; Possnert, Göran

    2009-03-01

    Accelerator mass spectrometry (AMS) is an ultra-sensitive analytical method suitable for the detection of sub-nM concentrations of labeled biological substances such as pharmaceutical drugs in body fluids. A limiting factor in extending the concentration measurements to the sub-pM range is the natural (14)C content in living tissues. This was circumvented by separating the labeled drug from the tissue matrix, using standard high-performance liquid chromatography (HPLC) procedures. As the separated total drug amount is in the few fg range, it is not possible to use a standard AMS sample preparation method, where mg sizes are required. We have utilized a sensitive carbon carrier method where a (14)C-deficient compound is added to the HPLC fractions and the composite sample is prepared and analyzed by AMS. Using 50 microL human blood plasma aliquots, we have demonstrated concentration measurements below 20 fM, containing sub-amol amounts of the labeled drug. The method has the immediate potential of operating in the sub-fM region. PMID:19177507

  12. Aluminum-26 as a biological tracer using accelerator mass spectrometry

    NASA Astrophysics Data System (ADS)

    Flarend, Richard Edward

    1997-06-01

    The development of accelerator mass spectrometry (AMS) has provided a practical method of detection for the only isotope of aluminum suitable as a tracer, 26Al. The use of 26Al as a tracer for aluminum has made possible the study of aluminum metabolism and the pharmacokinetics of aluminum-containing drugs at physiological levels. An overview of the various advantages of using 26Al as a tracer for aluminum and a general description of the AMS technique as applied to bio-medical applications is given. To illustrate the versatility of 26Al as a tracer for aluminum, 26Al studies of the past several years are discussed briefly. In addition, Two novel investigations dealing with 26Al-labeled drugs will be presented in more detail. In one of these studies, it was found that 26Al from aluminum hydroxide and aluminum phosphate vaccine adjuvants appeared in the blood just one hour after intramuscular injection. This is a surprising result since the currently held theory of how adjuvants work assumes that adjuvants remain insoluble and hold the antigen at the injection site for a long period of time. In another project, 26Al-labeled antiperspirants are being characterized by combining AMS with traditional analytical and chromatographic techniques. Future directions for this and other possible studies are discussed.

  13. Present and future prospects of accelerator mass spectrometry

    SciTech Connect

    Kutschera, W.

    1987-04-01

    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 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.

  14. Proof-of-concept development of PXAMS (projectile x-ray accelerator mass spectrometry)

    SciTech Connect

    Proctor, I.D.; Roberts, M.L.; McAninch, J.E.; Bench, G.S.

    1996-03-01

    Prior to the current work, accelerator mass spectrometry (AMS) was limited to a set of {approximately}8--10 isotopes. This limitation is caused primarily by the inability to discriminate against stable atomic isobars. An analysis scheme that combines the isotopic sensitivity of AMS with similar isobar selectivity would open a large new class of isotope applications. This project was undertaken to explore the use of characteristic x rays as a method for the detection and identification of ions,and to allow the post-spectrometer rejection of isobaric interferences for isotopes previously inaccessible to AMS. During the second half of FY94 (with Advanced Concepts funding from the Office of Non-Proliferation and National Security), we examined the feasability of this technique, which we are referring to as PXAMS (Projectile X ray AMS), to the detection of several isotopes at Lawrence Livermore National Laboratory (LLNL). In our first exploratory work, we measured the x ray yield vs energy for {sup 80}Se ions stopped in a thick Y target. These results, demonstrated that useful detection efficiencies could be obtained for Se ions at energies accessible with our accelerator, and that the count rate from target x rays is small compared to the Se K{alpha} rate. We followed these measurements with a survey of x ray yields for Z = 14-46.

  15. Sample preparation for quantitation of tritium by accelerator mass spectrometry.

    PubMed

    Chiarappa-Zucca, Marina L; Dingley, Karen H; Roberts, Mark L; Velsko, Carol A; Love, Adam H

    2002-12-15

    The capability to prepare samples accurately and reproducibly for analysis of tritium (3H) content by accelerator mass spectrometry (AMS) greatly facilitates isotopic tracer studies in which attomole levels of 3H can be measured in milligram-sized samples. A method has been developed to convert the hydrogen of organic samples to a solid, titanium hydride, which can be analyzed by AMS. Using a two-step process, the sample is first oxidized to carbon dioxide and water. In the second step, the water is transferred within a heated manifold into a quartz tube, reduced to hydrogen gas using zinc, and reacted with titanium powder. The 3H/1H ratio of the titanium hydride is measured by AMS and normalized to standards whose ratios were determined by decay counting to calculate the amount of 3H in the original sample. Water, organic compounds, and biological samples with 3H activities measured by liquid scintillation counting were utilized to develop and validate the method. The 3H/1H ratios were quantified in samples that spanned 5 orders of magnitude, from 10(-10) to 10(-15), with a detection limit of 3.0 x 10(-15), which is equivalent to 0.02 dpm tritium/mg of material. Samples smaller than 2 mg were analyzed following addition of 2 mg of a tritium-free-hydrogen carrier. Preparation of organic standards containing both 14C and 3H in 2-mg organic samples demonstrated that this sample preparation methodology can also be applied to quantify both of these isotopes from a single sample. PMID:12510750

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

    SciTech Connect

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

    1999-03-25

    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 Hodgkin's 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. Using accelerator mass spectrometry for radiocarbon dating of textiles

    SciTech Connect

    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.

  18. Design of a ram accelerator mass launch system

    NASA Technical Reports Server (NTRS)

    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.

  19. Physiology and transcriptomics of water-deficit stress responses in wheat cultivars TAM 111 and TAM 112

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hard red winter wheat crops on the U.S. Southern Great Plains often experience moderate to severe drought stress, especially during the grain filling stage, resulting in significant yield losses. Among popular commercial varieties, TAM 111 and TAM 112 showed a superior adaptation to water-deficit c...

  20. Physiology and transcriptomics of water-deficit stress responses in wheat cultivars TAM 111 and TAM 112

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hard red winter wheat crops on the U.S. Southern Great Plains often experience moderate to severe drought stress, especially during the grain filling stage, resulting in significant yield losses. Cultivars TAM 111 and TAM 112 are widely cultivated in the region, share parentage and showed superior b...

  1. Transition of Iodine Analysis to Accelerator Mass Spectrometry

    SciTech Connect

    J. E. Delmore

    2010-09-01

    Funding was received from NA-22 to investigate transitioning iodine isotopic analyses to an accelerator mass spectrometry (AMS) system. The present method uses gas-phase chemistry followed by thermal ionization mass spectrometry (TIMS). It was anticipated that the AMS approach could provide comparable data, with improved background levels and superior sample throughput. An aqueous extraction method was developed for removal of iodine species from high-volume air filters. Ethanol and sodium hydroxide, plus heating and ultrasonic treatment, were used to successfully extract iodine from loaded high-volume air filters. Portions of the same filters were also processed in the traditional method and analyzed by TIMS for comparison. Aliquot parts of the aqueous extracts were analyzed by AMS at the Swiss Federal Institute of Technology. Idaho National Laboratory (INL) personnel visited several AMS laboratories in the US, Spain, and Switzerland. Experience with AMS systems from several manufacturers was gained, and relationships were developed with key personnel at the laboratories. Three batches of samples were analyzed in Switzerland, and one in Spain. Results show that the INL extraction method successfully extracted enough iodine from high-volume air filters to allow AMS analysis. Comparison of the AMS and TIMS data is very encouraging; while the TIMS showed about forty percent more atoms of 129I, the 129/127 ratios tracked each other very well between the two methods. The time required for analysis is greatly reduced for the aqueous extraction/AMS approach. For a hypothetical batch of thirty samples, the AMS methodology is about five times faster than the traditional gas-phase chemistry and TIMS analysis. As an additional benefit, background levels for the AMS method are about 1000 times lower than for TIMS. This results from the fundamental mechanisms of ionization in the AMS system and cleanup of molecular interferences. We showed that an aqueous extraction of high

  2. Transition of Iodine Analysis to Accelerator Mass Spectrometry

    SciTech Connect

    M. L. Adamic; J. E. Olson; D. D. Jenson; J. G. Eisenmenger; M. G. Watrous

    2012-09-01

    This NA 22 funded research project investigated the transition of iodine isotopic analyses from thermal ionization mass spectrometry (TIMS) to an accelerator mass spectrometry (AMS) system. Previous work (Fiscal Year 2010) had demonstrated comparable data from TIMS and AMS. With AMS providing comparable data with improved background levels and vastly superior sample throughput, improvement in the sample extraction from environmental sample matrices was needed to bring sample preparation throughput closer to the operation level of the instrument. Previous research used an extraction chemistry that was not optimized for yield or refined for reduced labor to prove the principle. This research was done to find an extraction with better yield using less labor per sample to produce a sample ready for the AMS instrument. An extraction method using tetramethyl ammonium hydroxide (TMAH) was developed for removal of iodine species from high volume air filters. The TMAH with gentle heating was superior to the following three extraction methods: ammonium hydroxide aided by sonication, acidic and basic extraction aided by microwave, and ethanol mixed with sodium hydroxide. Taking the iodine from the extraction solvent to being ready for AMS analysis was accomplished by a direct precipitation, as well as, using silver wool to harvest the iodine from the TMAH. Portions of the same filters processed in FY 2010 were processed again with the improved extraction scheme followed by successful analysis by AMS at the Swiss Federal Institute of Technology. The data favorably matched the data obtained in 2010. The time required for analysis has been reduced over the aqueous extraction/AMS approach developed in FY 2010. For a hypothetical batch of 30 samples, the AMS methodology is about 10 times faster than the traditional gas phase chemistry and TIMS analysis. As an additional benefit, background levels for the AMS method are about 1000 times lower than TIMS. This results from the

  3. Transition of Iodine Analysis to Accelerator Mass Spectrometry

    SciTech Connect

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

    2015-09-01

    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

  4. Center for accelerator mass spectrometry Lawrence Livermore National Laboratory

    SciTech Connect

    Roberts, M.L.; Southon, J.R.; Proctor, I.D.

    1997-09-01

    The Center for Accelerator Mass Spectrometry (CAMS) at Lawrence Livermore National Laboratory (LLNL) is a multi-disciplinary research organization that conducts both technological and applications research. CAMS operates both an HVEC FN tandem and a NEC Model 5SDH-2 tandem accelerator. Using highly sensitive accelerator-based element and isotope detection methods, staff at CAMS collaborate with a broad scope of external and internal researchers to solve problems for LLNL, the University of California, the U.S. Department of Energy, and other academic, government, and industrial laboratories. The HVEC FN tandem is used by the LLNL Accelerator Mass Spectrometry (AMS) group. AMS is a technique that uses isotope ratio mass spectrometry at MeV energies to quantify long lived radioisotopes. For AMS, the FN tandem is operated under a distributed computer control system that makes possible rapid and precise switching between experimental configurations on a daily basis. The accelerator and beam lines are unshielded with radiation protection provided by a computer supervised radiation monitoring system and proximity shielding. With AMS, we routinely measure the isotopes {sup 3} H, {sup 7} Be, {sup 10} Be, {sup 14} C, {sup 26} Al, {sup 36} Cl, {sup 41} Ca, {sup 59} Ni, and {sup 129} I at abundances as low as 1 part in 10{sup 15} . Research programs are as diverse as archaeology, dosimetry of carcinogens and mutagens, oceanic and atmospheric chemistry, paleoclimatology, and detection of signatures of nuclear fuel reprocessing for non-proliferation purposes. During the past year our AMS group has run approximately 20,000 research samples. The NEC Model 5SDH-2 tandem accelerator is used by the Ion Micro Analysis Group (IMAG), a joint collaboration between LLNL and Sandia National Laboratories/California in biological and materials science research. The 1.7 MV accelerator and an Oxford Microbeams Quadrupole Triplet Lens System are used to create a 3 MeV micron scale focused ion

  5. The Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory

    SciTech Connect

    Roberts, M.L.; Heikkinen, D.W.; Southon, J.R.; Proctor, I.D.

    1996-10-01

    CAMS operates an HVEC FN tandem accelerator for use in both basic research and technology development. The accelerator is operated under a distributed computer control system with sophisticated auto-scaling, beam flat-topping, archiving, and recall capabilities, which makes possible rapid and precise switching between experimental configurations daily. Using the spectrometer, the AMS group can routinely measure the isotopes {sup 3}H, {sup 9}Be, {sup 10}Be, {sup 14}C, {sup 26}Al, {sup 36}Cl, {sup 41}Ca, and {sup 129}I at abundances as low as 1 part in 10{sup 16}.

  6. Investigations of paleoclimate variations using accelerator mass spectrometry

    SciTech Connect

    Southon, J R; Kashgarian, M; Brown, T A

    2000-08-24

    This project has used Accelerator Mass Spectrometry (AMS) {sup 14}C measurements to study climate and carbon cycle variations on time scales from decades to millennia over the past 30,000 years, primarily in the western US and the North Pacific. {sup 14}C dates provide a temporal framework for records of climate change, and natural radiocarbon acts as a carbon cycle tracer in independently dated records. The overall basis for the study is the observation that attempts to model future climate and carbon cycle changes cannot be taken seriously if the models have not been adequately tested. Paleoclimate studies are unique because they provide realistic test data under climate conditions significantly different from those of the present, whereas instrumental results can only sample the system as it is today. The aim of this project has been to better establish the extent, timing, and causes of past climate perturbations, and the carbon cycle changes with which they are linked. This provides real-world data for model testing, both for the development of individual models and also for inter-model diagnosis and comparison activities such as those of LLNL's PCMDI program; it helps us achieve a better basic understanding of how the climate system works so that models can be improved; and it gives an indication of the natural variability in the climate system underlying any anthropogenically-driven changes. The research has involved four projects which test hypotheses concerning the overall behavior of the North Pacific climate system. All are aspects of an overall theme that climate linkages are strong and direct, so that regional climate records are correlated, details of fine structure are important, and accurate and precise dating is critical for establishing correlations and even causality. An important requirement for such studies is the requirement for an accurate and precise radiocarbon calibration, to allow better correlation of radiocarbon-dated records with

  7. Holocene age of the Yuha burial: Direct radiocarbon determinations by accelerator mass spectrometry

    USGS Publications Warehouse

    Stafford, Thomas W.; Jull, A.J.T.; Zabel, T.H.; Donahue, D.J.; Duhamel, R.C.; Brendel, K.; Haynes, C.V.; Bischoff, J.L.; Payen, L.A.; Taylor, R.E.

    1984-01-01

    The view that human populations may not have arrived in the Western Hemisphere before about 12,000 radiocarbon yr BP1,2 has been challenged by claims of much greater antiquity for a small number of archaeological sites and human skeleton samples. One such site is the Homo sapiens sapiens cairn burial excavated in 1971 from the Yuha desert, Imperial County, California3-5. Radiocarbon analysis of caliche coating one of the bones of the skeleton yielded a radiocarbon age of 21,500??1,000 yr BP4, while radiocarbon and uranium series analyses of caliche coating a cairn boulder yielded ages of 22,125??400 and 19,000??3,000 yr BP, respectively5. The late Pleistocene age assignment to the Yuha burial has been challenged by comparing the cultural context of the burial with other cairn burials in the same region6, on the basis of the site's geomorphological context and from radiocarbon analyses of soil caliches. 7,8 In rebuttal, arguments in defence of the original age assignment have been presented9,10 as well as an amino acid racemization analysis on the Yuha skeleton indicating an age of 23,600??2,600 yr BP11. The tandem accelerator mass spectrometer at the University of Arizona has now been used to measure the ratio of 14C/13C in several organic and inorganic fractions of post-cranial bone from the Yuha H. sapiens sapiens skeleton. Isotope ratios from six chemical fractions all yielded radiocarbon ages for the skeleton of less than 4,000 yr BP. These results indicate that the Yuha skeleton is of Holocene age, in agreement with the cultural context of the burial, and in disagreement with the previously assigned Pleistocene age of 19,000-23,000 yr. ?? 1984 Nature Publishing Group.

  8. Full-scale results for TAM limestone injection

    SciTech Connect

    Baer, S.

    1996-12-31

    Information is outlined on the use of thermally active marble (TAM) sorbents in boilers. Data are presented on: the comparison of TAM to limestone; NOVACON process development history; CFB test history; CFB pilot scale test; full-scale CFB trial; August, 1996 CFB demonstration; Foster Wheeler Mount Carmel sorbent feed rate comparison and Ca:S comparison; unburned carbon is ash; and advantages and savings in CFB boilers.

  9. A compact permanent magnet cyclotrino for accelerator mass spectrometry

    SciTech Connect

    Young, A.T.; Clark, D.J.; Kunkel, W.B.; Leung, K.N.; Li, C.Y.

    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}.

  10. TAM receptors regulate multiple features of microglial physiology.

    PubMed

    Fourgeaud, Lawrence; Través, Paqui G; Tufail, Yusuf; Leal-Bailey, Humberto; Lew, Erin D; Burrola, Patrick G; Callaway, Perri; Zagórska, Anna; Rothlin, Carla V; Nimmerjahn, Axel; Lemke, Greg

    2016-04-14

    Microglia are damage sensors for the central nervous system (CNS), and the phagocytes responsible for routine non-inflammatory clearance of dead brain cells. Here we show that the TAM receptor tyrosine kinases Mer and Axl regulate these microglial functions. We find that adult mice deficient in microglial Mer and Axl exhibit a marked accumulation of apoptotic cells specifically in neurogenic regions of the CNS, and that microglial phagocytosis of the apoptotic cells generated during adult neurogenesis is normally driven by both TAM receptor ligands Gas6 and protein S. Using live two-photon imaging, we demonstrate that the microglial response to brain damage is also TAM-regulated, as TAM-deficient microglia display reduced process motility and delayed convergence to sites of injury. Finally, we show that microglial expression of Axl is prominently upregulated in the inflammatory environment that develops in a mouse model of Parkinson's disease. Together, these results establish TAM receptors as both controllers of microglial physiology and potential targets for therapeutic intervention in CNS disease. PMID:27049947

  11. 75 FR 70966 - Transit Asset Management (TAM) Pilot Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-19

    ... that a significant portion of the nation's public transportation assets are in need of capital... in place for managing the condition of their capital assets in a holistic manner. Effective TAM systems use quality data ] and well-defined objectives as part of a systematic process to...

  12. Accelerator mass spectrometry at the 4 MV Dynamitron Tandem in Bochum

    NASA Astrophysics Data System (ADS)

    Lubritto, C.; Rogalla, D.; Rubino, M.; Marzaioli, F.; Passariello, I.; Romano, M.; Spadaccini, G.; Casa, G.; Di Leva, A.; De Cesare, N.; D'Onofrio, A.; Gialanella, L.; Imbriani, G.; Palmieri, A.; Roca, V.; Rolfs, C.; Sabbarese, C.; Strieder, F.; Schüermann, D.; Terrasi, F.

    2004-07-01

    A feasibility test for Accelerator Mass Spectrometry has been carried out successfully at the 4 MV Dynamitron Tandem Laboratory in Bochum in conjunction with a new recoil separator. We describe the facility as well as results concerning the reproducibility and accuracy of 14C content measurements of several standard samples.

  13. DOE Project 353: TAMS Prototype and production coupling alignment units

    SciTech Connect

    Field, K.V.

    1996-02-01

    TAMS is an electronic measurement system used to determine the alignment of turbine-generator shafts at the coupling interface. The displacement transducer is a strain gage based sensor mounted in a portable probe. The measurement system was experiencing zero input drift and temperature induced drift. This project endeavored to determine the source of these problems and to revise a unit to be returned to a customer, Baltimore Gas and Electric (BGE), within a period of five weeks.

  14. The regulatory role of Streptomyces coelicolor TamR in central metabolism.

    PubMed

    Huang, Hao; Sivapragasam, Smitha; Grove, Anne

    2015-03-01

    Trans-aconitate methyltransferase regulator (TamR) is a member of the ligand-responsive multiple antibiotic resistance regulator (MarR) family of transcription factors. In Streptomyces coelicolor, TamR regulates transcription of tamR (encoding TamR), tam (encoding trans-aconitate methyltransferase) and sacA (encoding aconitase); up-regulation of these genes promotes metabolic flux through the citric acid cycle. DNA binding by TamR is attenuated and transcriptional derepression is achieved on binding of ligands such as citrate and trans-aconitate to TamR. In the present study, we show that three additional genes are regulated by S. coelicolor TamR. Genes encoding malate synthase (aceB1; SCO6243), malate dehydrogenase (mdh; SCO4827) and isocitrate dehydrogenase (idh; SCO7000) are up-regulated in vivo when citrate and trans-aconitate accumulate, and TamR binds the corresponding gene promoters in vitro, a DNA binding that is attenuated by cognate ligands. Mutations to the TamR binding site attenuate DNA binding in vitro and result in constitutive promoter activity in vivo. The predicted TamR binding sites are highly conserved in the promoters of these genes in Streptomyces species that encode divergent tam-tamR gene pairs, suggesting evolutionary conservation. Like aconitase and trans-aconitate methyltransferase, malate dehydrogenase, isocitrate dehydrogenase and malate synthase are closely related to the citric acid cycle, either catalysing individual reaction steps or, in the case of malate synthase, participating in the glyoxylate cycle to produce malate that enters the citric acid cycle to replenish the intermediate pool. Taken together, our data suggest that TamR plays an important and conserved role in promoting metabolic flux through the citric acid cycle.

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

    PubMed

    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.

  16. AixMICADAS, the accelerator mass spectrometer dedicated to 14C recently installed in Aix-en-Provence, France

    NASA Astrophysics Data System (ADS)

    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 significant surface contamination. By contrast, the tests also show that the leached CO2 from very old carbonates is significantly "younger" than the residual sample. This study, though preliminary, already confirms that pretreatment by acid leaching of old carbonates is essential if we are to accurately measure the true age of such samples.

  17. Cytoplasmic PELP1 and ERRgamma protect human mammary epithelial cells from Tam-induced cell death.

    PubMed

    Girard, Brian J; Regan Anderson, Tarah M; Welch, Siya Lem; Nicely, Julie; Seewaldt, Victoria L; Ostrander, Julie H

    2015-01-01

    Tamoxifen (Tam) is the only FDA-approved chemoprevention agent for pre-menopausal women at high risk for developing breast cancer. While Tam reduces a woman's risk of developing estrogen receptor positive (ER+) breast cancer, the molecular mechanisms associated with risk reduction are poorly understood. Prior studies have shown that cytoplasmic proline, glutamic acid and leucine rich protein 1 (PELP1) promotes Tam resistance in breast cancer cell lines. Herein, we tested for PELP1 localization in breast epithelial cells from women at high risk for developing breast cancer and found that PELP1 was localized to the cytoplasm in 36% of samples. In vitro, immortalized HMECs expressing a nuclear localization signal (NLS) mutant of PELP1 (PELP1-cyto) were resistant to Tam-induced death. Furthermore, PELP1-cyto signaling through estrogen-related receptor gamma (ERRγ) promoted cell survival in the presence of Tam. Overexpression of ERRγ in immortalized HMECs protected cells from Tam-induced death, while knockdown of ERRγ sensitized PELP1-cyto expressing HMECs to Tam. Moreover, Tam-induced HMEC cell death was independent of apoptosis and involved accumulation of the autophagy marker LC3-II. Expression of PELP1-cyto and ERRγ reduced Tam-induced LC3-II accumulation, and knockdown of ERRγ increased LC3-II levels in response to Tam. Additionally, PELP1-cyto expression led to the upregulation of MMP-3 and MAOB, known PELP1 and ERRγ target genes, respectively. Our data indicate that cytoplasmic PELP1 induces signaling pathways that converge on ERRγ to promote cell survival in the presence of Tam. These data suggest that PELP1 localization and/or ERRγ activation could be developed as tissue biomarkers for Tam responsiveness.

  18. Cytoplasmic PELP1 and ERRgamma Protect Human Mammary Epithelial Cells from Tam-Induced Cell Death

    PubMed Central

    Girard, Brian J.; Regan Anderson, Tarah M.; Welch, Siya Lem; Nicely, Julie; Seewaldt, Victoria L.; Ostrander, Julie H.

    2015-01-01

    Tamoxifen (Tam) is the only FDA-approved chemoprevention agent for pre-menopausal women at high risk for developing breast cancer. While Tam reduces a woman's risk of developing estrogen receptor positive (ER+) breast cancer, the molecular mechanisms associated with risk reduction are poorly understood. Prior studies have shown that cytoplasmic proline, glutamic acid and leucine rich protein 1 (PELP1) promotes Tam resistance in breast cancer cell lines. Herein, we tested for PELP1 localization in breast epithelial cells from women at high risk for developing breast cancer and found that PELP1 was localized to the cytoplasm in 36% of samples. In vitro, immortalized HMECs expressing a nuclear localization signal (NLS) mutant of PELP1 (PELP1-cyto) were resistant to Tam-induced death. Furthermore, PELP1-cyto signaling through estrogen-related receptor gamma (ERRγ) promoted cell survival in the presence of Tam. Overexpression of ERRγ in immortalized HMECs protected cells from Tam-induced death, while knockdown of ERRγ sensitized PELP1-cyto expressing HMECs to Tam. Moreover, Tam-induced HMEC cell death was independent of apoptosis and involved accumulation of the autophagy marker LC3-II. Expression of PELP1-cyto and ERRγ reduced Tam-induced LC3-II accumulation, and knockdown of ERRγ increased LC3-II levels in response to Tam. Additionally, PELP1-cyto expression led to the upregulation of MMP-3 and MAOB, known PELP1 and ERRγ target genes, respectively. Our data indicate that cytoplasmic PELP1 induces signaling pathways that converge on ERRγ to promote cell survival in the presence of Tam. These data suggest that PELP1 localization and/or ERRγ activation could be developed as tissue biomarkers for Tam responsiveness. PMID:25789479

  19. Searching For A Suitable Gas Ion Source For 14C Accelerator Mass Spectrometry

    SciTech Connect

    Reden, Karl von; Roberts, Mark; Han, Baoxi; Schneider, Robert; Wills, John

    2007-08-10

    This paper describes the challenges facing 14C Accelerator Mass Spectrometry (AMS) in the effort to directly analyze the combusted effluent of a chromatograph (or any other continuous source of sample material). An efficient, low-memory negative gas ion source would greatly simplify the task to make this a reality. We discuss our tests of a microwave ion source charge exchange canal combination, present an improved design, and hope to generate more interest in the negative ion source community to develop a direct-extraction negative carbon gas ion source for AMS.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

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

    1999-06-10

    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 {sup 14}C-labeled pharmaceuticals used in clinical nuclear medicine and biomedical research.

  2. Determination of protein-ligand interactions using accelerator mass spectrometry: modified crosslinking assay.

    PubMed

    Hah, Sang Soo

    2009-05-01

    A highly sensitive detection method for the determination of protein-ligand interactions has been developed. Radiocarbon-labeled 17beta-estradiol was incubated with estrogen receptor-alpha; as a selective binding partner, and covalently attached using crosslinking agents, to form covalently linked protein-ligand complexes. After separation using a denaturing gel, the (14)C content in the sliced gels was identified by accelerator mass spectrometry. The obtained data demonstrated specific binding of the small molecule to its binding partner. In theory, this method can be applied to most protein-ligand interaction studies.

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

    NASA Astrophysics Data System (ADS)

    Tumey, Scott J.; Brown, Thomas A.; Hamilton, Terry E.; Hillegonds, Darren J.

    2008-05-01

    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 90Sr by accelerator mass spectrometry. Despite a pervasive interference from 90Zr, our initial development has yielded an instrumental background of ∼108 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 106 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.

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

    SciTech Connect

    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.

  5. Measurement of Uranium Isotopes in Particles of U3O8 by Secondary Ion Mass Spectrometry-Single-Stage Accelerator Mass Spectrometry (SIMS-SSAMS).

    PubMed

    Fahey, Albert J; Groopman, Evan E; Grabowski, Kenneth S; Fazel, Kamron C

    2016-07-19

    A commercial secondary ion mass spectrometer (SIMS) was coupled to a ± 300 kV single-stage accelerator mass spectrometer (SSAMS). Positive secondary ions generated with the SIMS were injected into the SSAMS for analysis. This combined instrument was used to measure the uranium isotopic ratios in particles of three certified reference materials (CRM) of uranium, CRM U030a, CRM U500, and CRM U850. The ability to inject positive ions into the SSAMS is unique for AMS systems and allows for simple analysis of nearly the entire periodic table because most elements will readily produce positive ions. Isotopic ratios were measured on samples of a few picograms to nanograms of total U. Destruction of UH(+) ions in the stripper tube of the SSAMS reduced hydride levels by a factor of ∼3 × 10(4) giving the UH(+)/U(+) ratio at the SSAMS detector of ∼1.4 × 10(-8). These hydride ion levels would allow the measurement of (239)Pu at the 10 ppb level in the presence of U and the equivalent of ∼10(-10 236)U concentration in natural uranium. SIMS-SSAMS analysis of solid nuclear materials, such as these, with signals nearly free of molecular interferences, could have a significant future impact on the way some measurements are made for nuclear nonproliferation. PMID:27321905

  6. Measurement of Uranium Isotopes in Particles of U3O8 by Secondary Ion Mass Spectrometry-Single-Stage Accelerator Mass Spectrometry (SIMS-SSAMS).

    PubMed

    Fahey, Albert J; Groopman, Evan E; Grabowski, Kenneth S; Fazel, Kamron C

    2016-07-19

    A commercial secondary ion mass spectrometer (SIMS) was coupled to a ± 300 kV single-stage accelerator mass spectrometer (SSAMS). Positive secondary ions generated with the SIMS were injected into the SSAMS for analysis. This combined instrument was used to measure the uranium isotopic ratios in particles of three certified reference materials (CRM) of uranium, CRM U030a, CRM U500, and CRM U850. The ability to inject positive ions into the SSAMS is unique for AMS systems and allows for simple analysis of nearly the entire periodic table because most elements will readily produce positive ions. Isotopic ratios were measured on samples of a few picograms to nanograms of total U. Destruction of UH(+) ions in the stripper tube of the SSAMS reduced hydride levels by a factor of ∼3 × 10(4) giving the UH(+)/U(+) ratio at the SSAMS detector of ∼1.4 × 10(-8). These hydride ion levels would allow the measurement of (239)Pu at the 10 ppb level in the presence of U and the equivalent of ∼10(-10 236)U concentration in natural uranium. SIMS-SSAMS analysis of solid nuclear materials, such as these, with signals nearly free of molecular interferences, could have a significant future impact on the way some measurements are made for nuclear nonproliferation.

  7. Monolithic spectrometer

    DOEpatents

    Rajic, S.; Egert, C.M.; Kahl, W.K.; Snyder, W.B. Jr.; Evans, B.M. III; Marlar, T.A.; Cunningham, J.P.

    1998-05-19

    A monolithic spectrometer is disclosed for use in spectroscopy. The spectrometer is a single body of translucent material with positioned surfaces for the transmission, reflection and spectral analysis of light rays. 6 figs.

  8. Monolithic spectrometer

    DOEpatents

    Rajic, Slobodan; Egert, Charles M.; Kahl, William K.; Snyder, Jr., William B.; Evans, III, Boyd M.; Marlar, Troy A.; Cunningham, Joseph P.

    1998-01-01

    A monolithic spectrometer is disclosed for use in spectroscopy. The spectrometer is a single body of translucent material with positioned surfaces for the transmission, reflection and spectral analysis of light rays.

  9. Questions First: Introducing Critical Thinking Using the Text Analysis Matrix (TAM)

    ERIC Educational Resources Information Center

    Keller, J. Gregory

    2008-01-01

    Critical thinking skills are crucial for both academic and everyday life. This paper presents the author's Text Analysis Matrix (TAM), a model for developing skills for the critical examination of texts. The TAM guidelines involve finding and clarifying the main claims of a text, discovering and assessing arguments, uncovering the implications for…

  10. Understanding Student Teachers' Behavioural Intention to Use Technology: Technology Acceptance Model (TAM) Validation and Testing

    ERIC Educational Resources Information Center

    Wong, Kung-Teck; Osman, Rosma bt; Goh, Pauline Swee Choo; Rahmat, Mohd Khairezan

    2013-01-01

    This study sets out to validate and test the Technology Acceptance Model (TAM) in the context of Malaysian student teachers' integration of their technology in teaching and learning. To establish factorial validity, data collected from 302 respondents were tested against the TAM using confirmatory factor analysis (CFA), and structural equation…

  11. Technology acceptance among physicians: a new take on TAM.

    PubMed

    Yarbrough, Amy K; Smith, Todd B

    2007-12-01

    The proliferation of information technology has been a revolutionary force that has increased efficiency and effectiveness in many industries. However, health care organizations, particularly physician practices, are noticeably lagging in the adoption of such technologies. This article provides a systematic review of the literature on physician acceptance of information technology. An overview of the technology acceptance model (TAM) is discussed, and a modified version of this model is proposed. Finally, ideas for testing this new model in a physician setting are presented. By providing a better understanding of physician technology acceptance, this model will inform health care managers about barriers that make physicians hesitant to embrace new technologies designed to increase efficiency and improve quality in a health care setting.

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

    NASA Astrophysics Data System (ADS)

    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).

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

    SciTech Connect

    Taylor, R E

    1991-08-20

    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 ({sup 14}C) and radiocalcium ({sup 41}Ca) involving applications to archaeologically -- and paleoanthropologically- related samples. With regard to AMS {sup 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{sub 2} to graphitic carbon which will consistently yield relatively high {sup 13}C{sup {minus}} ion currents and blanks which will yield, on a consistent basis, {sup 14}C count rates at or below 0.20% modern, giving an 2 sigma age limit of >50,000 yr BP.

  14. A new world of biomedical research - the Center for Accelerator Mass Spectrometry

    SciTech Connect

    Holloway, C.

    1997-11-01

    Lawrence Livermore`s Center for Accelerator Mass Spectrometry (AMS) is one of the leading AMS facilities in the world, performing about 25% of all AMS analyses. It is also at the forefront of the emerging field of AMS as applied to biomedical research. AMS is so sensitive that it can identify just a few molecules of a substance among trillions of molecules. This sensitivity makes possible for the first time the study of toxins, dietary nutrients, drugs, and other substances in dosages that are relevant to humans. Work with volunteer subjects indicates that a chemical that is produced when meat is cooked adversely affects human DNA more than it does the DNA of laboratory animals. This research supports the need to pursue additional human biological risk assessment using AMS. Livermore is also performing studies of the human metabolism of calcium, which are difficult without AMS.

  15. High temperature pyrolysis to extract 36Cl for Accelerator Mass Spectrometry measurements

    NASA Astrophysics Data System (ADS)

    Cornett, R. J.; Andrews, H. R.; Chant, L.; Chaput, T.; Imahori, Y.; Jirovec, J.; Kramer, S.; Koslowsky, V. T.; Milton, G. M.; Milton, J. C. D.

    1996-10-01

    36Cl and stable Cl were extracted from solids by high temperature pyrolysis and then analyzed by Accelerator Mass Spectrometry (AMS). Cl was quantitatively extracted from rock, ore, vegetation and freshwater sediments in samples weighing from 100 mg to 2 g. 36Cl:Cl activity ratios measured following Cl extraction by pyrolysis agreed with those measured following Cl extraction by acid leaching. The simple pyrolysis extraction has the additional advantages that stable Cl - can be measured on the same sample along with other anions, the 36Cl:Cl ratio can be adjusted by diluting the known Cl - concentration in the collection solution to control the activity of 36Cl in the target and the potential interference of 36S can also be assessed prior to the AMS measurements.

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

    PubMed

    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

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

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

    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 35Cl/37Cl-ratio and samples highly-enriched in 35Cl (35Cl/37Cl ∼ 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 61 and 1390 s, where the modified DREAMS ion source with values between 156 and 262 s showed the fastest recovery in 80% of the measurements.

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

    SciTech Connect

    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

  19. Challenging developments in three decades of accelerator mass spectrometry at ETH: from large particle accelerators to table size instruments.

    PubMed

    Suter, Martin

    2010-01-01

    Accelerator mass spectrometry (AMS) was invented for the detection of radiocarbon at natural isotopic concentrations (10(-12) to 10(-15)) more than 30 years ago. Meanwhile this method has also been applied for the analysis of many other long-lived radioisotopes, which are found at very low concentrations. The first investigations were made at large tandem accelerators originally built for nuclear physics research and operating at voltages of 6-12 MV. Today dedicated instruments are mostly used for AMS, which are optimized for associated applications. In the past 15 years, a new generation of much smaller instruments has been developed. For many years it was believed that accelerators with voltages of 2 MV or higher are needed to eliminate the molecular interferences. At these energies the ions are predominantly stripped to charge state 3+, thereby removing the binding electrons of the molecules. In contrast, the new compact facilities use 1+ or 2+ ions. In this case the molecular destruction process is based on molecule-atom collisions in the gas cell. The cross sections for this destruction are sufficiently large that the intensity of molecular components such as (12)CH(2) and (13)CH can be reduced by 10 orders of magnitude. These new facilities can be built much smaller due to the lower energies. Universal instruments providing analysis for many isotopes over the whole range of periodic table have a space requirement of about 4 x 6 m(2); dedicated radiocarbon facilities based on a 200 kV accelerator have a footprint of about 2.5 x 3 m(2). This smallest category of instruments use special technologies: The high voltage terminal with the gas stripper canal is vacuum insulated and the gas is pumped to ground potential through a ceramic pipe. A conventional 200 kV power supply provides the terminal voltage from outside. A review of this new generation of compact AMS facilities is given. Design considerations and performance of these new instruments will be presented

  20. Correlation spectrometer

    DOEpatents

    Sinclair, Michael B.; Pfeifer, Kent B.; Flemming, Jeb H.; Jones, Gary D.; Tigges, Chris P.

    2010-04-13

    A correlation spectrometer can detect a large number of gaseous compounds, or chemical species, with a species-specific mask wheel. In this mode, the spectrometer is optimized for the direct measurement of individual target compounds. Additionally, the spectrometer can measure the transmission spectrum from a given sample of gas. In this mode, infrared light is passed through a gas sample and the infrared transmission signature of the gasses present is recorded and measured using Hadamard encoding techniques. The spectrometer can detect the transmission or emission spectra in any system where multiple species are present in a generally known volume.

  1. Subcellular compartmentalization of Cd and Zn in two bivalves. II. Significance of trophically available metal (TAM)

    USGS Publications Warehouse

    Wallace, W.G.; Luoma, S.N.

    2003-01-01

    This paper examines how the subcellular partitioning of Cd and Zn in the bivalves Macoma balthica and Potamocorbula amurensis may affect the trophic transfer of metal to predators. Results show that the partitioning of metals to organelles, 'enzymes' and metallothioneins (MT) comprise a subcellular compartment containing trophically available metal (TAM; i.e. metal trophically available to predators), and that because this partitioning varies with species, animal size and metal, TAM is similarly influenced. Clams from San Francisco Bay, California, were exposed for 14 d to 3.5 ??g 1-1 Cd and 20.5 ??g 1-1 Zn, including 109Cd and 65Zn as radiotracers, and were used in feeding experiments with grass shrimp Palaemon macrodatylus, or used to investigate the subcellular partitioning of metal. Grass shrimp fed Cd-contaminated P. amurensis absorbed ???60% of ingested Cd, which was in accordance with the partitioning of Cd to the bivalve's TAM compartment (i.e. Cd associated with organelles, 'enzymes' and MT); a similar relationship was found in previous studies with grass shrimp fed Cd-contaminated oligochaetes. Thus, TAM may be used as a tool to predict the trophic transfer of at least Cd. Subcellular fractionation revealed that ???34% of both the Cd and Zn accumulated by M. balthica was associated with TAM, while partitioning to TAM in P. amurensis was metal-dependent (???60% for TAM-Cd%, ???73% for TAM-Zn%). The greater TAM-Cd% of P. amurensis than M. balthica is due to preferential binding of Cd to MT and 'enzymes', while enhanced TAM-Zn% of P. amurensis results from a greater binding of Zn to organelles. TAM for most species-metal combinations was size-dependent, decreasing with increased clam size. Based on field data, it is estimated that of the 2 bivalves, P. amurensis poses the greater threat of Cd exposure to predators because of higher tissue concentrations and greater partitioning as TAM; exposure of Zn to predators would be similar between these species.

  2. Accelerator Mass Spectrometry Measurements of Plutonium in Sediment and Seawater from the Marshall Islands

    SciTech Connect

    Leisvik, M; Hamilton, T

    2001-08-01

    During the summer 2000, I was given the opportunity to work for about three months as a technical trainee at Lawrence Livermore National Laboratory, or LLNL as I will refer to it hereafter. University of California runs this Department of Energy laboratory, which is located 70 km east of San Francisco, in the small city of Livermore. This master thesis in Radioecology is based on the work I did here. LLNL, as a second U.S.-facility for development of nuclear weapons, was built in Livermore in the beginning of the 1950's (Los Alamos in New Mexico was the other one). It has since then also become a 'science center' for a number of areas like magnetic and laser fusion energy, non-nuclear energy, biomedicine, and environmental science. The Laboratory's mission has changed over the years to meet new national needs. The following two statements were found on the homepage of LLNL (http://www.llnl.gov), at 2001-03-05, where also information about the laboratory and the scientific projects that takes place there, can be found. 'Our primary mission is to ensure that the nation's nuclear weapons remain safe, secure, and reliable and to prevent the spread and use of nuclear weapons worldwide'. 'Our goal is to apply the best science and technology to enhance the security and well-being of the nation and to make the world a safer place.' The Marshall Islands Dose Assessment and Radioecology group at the Health and Ecological Assessments division employed me, and I also worked to some extent with the Centre for Accelerator Mass Spectrometry (CAMS) group. The work I did at LLNL can be divided into two parts. In the first part Plutonium (Pu) measurements in sediments from the Rongelap atoll in Marshall Islands, using Accelerator Mass Spectrometry (AMS) were done. The method for measuring these kinds of samples is well understood at LLNL since soil samples have been measured with AMS for Pu in the past. Therefore it was the results that were of main interest and not the technique

  3. Measurement of Actinides in Environmental Samples at Micro-Becquerel Levels by Accelerator Mass Spectrometry

    SciTech Connect

    Brown, T A; Knezovich, J P; Marchetti, A A; Hamilton, T F

    2002-09-03

    The need for ultra-sensitive actinide measurements continues to expand in the fields of environmental stewardship, nuclear isotope forensics, radiobioassay and environmental research. We have developed a heavy isotope accelerator mass spectrometry (AMS) system at Lawrence Livermore National Laboratory's Center for Accelerator Mass Spectrometry (CAMS). The system was designed particularly for the measurement of actinide concentrations and isotopic ratios. A fast isotope switching capability has been incorporated in the system, allowing flexibility in isotope selection and for the quasi-continuous normalization to a reference isotope spike. Initially, our utilization of the system has concentrated on the measurement of Pu isotopes. Under current operating conditions, background levels equivalent to <10{sup 6} atoms are observed during routine {sup 239}Pu and {sup 240}Pu measurements. Measurements of samples containing 10{sup 13} {sup 238}U atoms demonstrate that the system provides a {sup 238}U rejection factor of >10{sup 7}. Recently, we have utilized the high dynamic range of the AMS system in measuring samples whose Pu contents ranged from <10{sup 6} (background) to >10{sup 11} Pu atoms. Measurements of known materials, combined with results from an externally organized intercomparison program, indicate that our {sup 239}Pu measurements are accurate and precise down to the {mu}Bq level ({approx}10{sup 6} atoms). The development of the heavy isotope system was undertaken with particular interest in the measurement of environmental samples, including soils, sediments, waters, air filters, tissue samples, and human urine. The high rejection of interferences, including molecular interferences, and low susceptibility to matrix components, provided by the AMS technique are of particular relevance for such complex samples. These two factors significantly reduce demands on sample preparation chemistry for Pu analyses, allowing relatively simple, cost-effective procedures

  4. Multidimensional spectrometer

    DOEpatents

    Zanni, Martin Thomas; Damrauer, Niels H.

    2010-07-20

    A multidimensional spectrometer for the infrared, visible, and ultraviolet regions of the electromagnetic spectrum, and a method for making multidimensional spectroscopic measurements in the infrared, visible, and ultraviolet regions of the electromagnetic spectrum. The multidimensional spectrometer facilitates measurements of inter- and intra-molecular interactions.

  5. Method for (236)U Determination in Seawater Using Flow Injection Extraction Chromatography and Accelerator Mass Spectrometry.

    PubMed

    Qiao, Jixin; Hou, Xiaolin; Steier, Peter; Nielsen, Sven; Golser, Robin

    2015-07-21

    An automated analytical method implemented in a flow injection (FI) system was developed for rapid determination of (236)U in 10 L seawater samples. (238)U was used as a chemical yield tracer for the whole procedure, in which extraction chromatography (UTEVA) was exploited to purify uranium, after an effective iron hydroxide coprecipitation. Accelerator mass spectrometry (AMS) was applied for quantifying the (236)U/(238)U ratio, and inductively coupled plasma mass spectrometry (ICPMS) was used to determine the absolute concentration of (238)U; thus, the concentration of (236)U can be calculated. The key experimental parameters affecting the analytical effectiveness were investigated and optimized in order to achieve high chemical yields and simple and rapid analysis as well as low procedure background. Besides, the operational conditions for the target preparation prior to the AMS measurement were optimized, on the basis of studying the coprecipitation behavior of uranium with iron hydroxide. The analytical results indicate that the developed method is simple and robust, providing satisfactory chemical yields (80-100%) and high analysis speed (4 h/sample), which could be an appealing alternative to conventional manual methods for (236)U determination in its tracer application. PMID:26105019

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

    PubMed

    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.

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

    PubMed

    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).

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

    PubMed

    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.

  9. DNA isolation and sample preparation for quantification of adduct levels by accelerator mass spectrometry.

    PubMed

    Dingley, Karen H; Ubick, Esther A; Vogel, John S; Ognibene, Ted J; Malfatti, Michael A; Kulp, Kristen; Haack, Kurt W

    2014-01-01

    Accelerator mass spectrometry (AMS) is a highly sensitive technique used for the quantification of adducts following exposure to carbon-14- or tritium-labeled chemicals, with detection limits in the range of one adduct per 10(11)-10(12) nucleotides. The protocol described in this chapter provides an optimal method for isolating and preparing DNA samples to measure isotope-labeled DNA adducts by AMS. When preparing samples, special precautions must be taken to avoid cross-contamination of isotope among samples and produce a sample that is compatible with AMS. The DNA isolation method described is based upon digestion of tissue with proteinase K, followed by extraction of DNA using Qiagen isolation columns. The extracted DNA is precipitated with isopropanol, washed repeatedly with 70 % ethanol to remove salt, and then dissolved in water. DNA samples are then converted to graphite or titanium hydride and the isotope content measured by AMS to quantify adduct levels. This method has been used to reliably generate good yields of uncontaminated, pure DNA from animal and human tissues for analysis of adduct levels.

  10. DNA isolation and sample preparation for quantification of adduct levels by accelerator mass spectrometry.

    PubMed

    Dingley, Karen H; Ubick, Esther A; Vogel, John S; Ognibene, Ted J; Malfatti, Michael A; Kulp, Kristen; Haack, Kurt W

    2014-01-01

    Accelerator mass spectrometry (AMS) is a highly sensitive technique used for the quantification of adducts following exposure to carbon-14- or tritium-labeled chemicals, with detection limits in the range of one adduct per 10(11)-10(12) nucleotides. The protocol described in this chapter provides an optimal method for isolating and preparing DNA samples to measure isotope-labeled DNA adducts by AMS. When preparing samples, special precautions must be taken to avoid cross-contamination of isotope among samples and produce a sample that is compatible with AMS. The DNA isolation method described is based upon digestion of tissue with proteinase K, followed by extraction of DNA using Qiagen isolation columns. The extracted DNA is precipitated with isopropanol, washed repeatedly with 70 % ethanol to remove salt, and then dissolved in water. DNA samples are then converted to graphite or titanium hydride and the isotope content measured by AMS to quantify adduct levels. This method has been used to reliably generate good yields of uncontaminated, pure DNA from animal and human tissues for analysis of adduct levels. PMID:24623226

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

    SciTech Connect

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

    2000-01-31

    {beta}-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 {beta}-[{sup 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 {beta}-carotene was lost slowly via urine in accord with the slow body turnover of {beta}-carotene and vitamin A [4]. HPLC fractionation of plasma taken at early time points (0-24-h) showed the label was distributed between {beta}-carotene and retinyl esters (vitamin A) derived from intestinal metabolism.

  12. Ultrasensitive detection of inhaled organic aerosol particles by accelerator mass spectrometry.

    PubMed

    Parkhomchuk, E V; Gulevich, D G; Taratayko, A I; Baklanov, A M; Selivanova, A V; Trubitsyna, T A; Voronova, I V; Kalinkin, P N; Okunev, A G; Rastigeev, S A; Reznikov, V A; Semeykina, V S; Sashkina, K A; Parkhomchuk, V V

    2016-09-01

    Accelerator mass spectrometry (AMS) was shown to be applicable for studying the penetration of organic aerosols, inhaled by laboratory mice at ultra-low concentration ca. 10(3) cm(-3). We synthesized polystyrene (PS) beads, composed of radiocarbon-labeled styrene, for testing them as model organic aerosols. As a source of radiocarbon we used methyl alcohol with radioactivity. Radiolabeled polystyrene beads were obtained by emulsifier-free emulsion polymerization of synthesized (14)C-styrene initiated by K2S2O8 in aqueous media. Aerosol particles were produced by pneumatic spraying of diluted (14)C-PS latex. Mice inhaled (14)C-PS aerosol consisting of the mix of 10(3) 225-nm particles per 1 cm(3) and 5·10(3) 25-nm particles per 1 cm(3) for 30 min every day during five days. Several millions of 225-nm particles deposited in the lungs and slowly excreted from them during two weeks of postexposure. Penetration of particles matter was also observed for liver, kidneys and brain, but not for a heart. PMID:27281540

  13. Ultrasensitive detection method for primordial nuclides in copper with Accelerator Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Famulok, N.; Faestermann, T.; Fimiani, L.; Gómez-Guzmán, J. M.; Hain, K.; Korschinek, G.; Ludwig, P.; Schönert, S.

    2015-10-01

    The sensitivity of rare event physics experiments like neutrino or direct dark matter detection crucially depends on the background level. A significant background contribution originates from the primordial actinides thorium (Th) and uranium (U) and the progenies of their decay chains. The applicability of ultra-sensitive Accelerator Mass Spectrometry (AMS) for the direct detection of Th and U impurities in three copper samples is evaluated. Although AMS has been proven to reach outstanding sensitivities for long-lived isotopes, this technique has only very rarely been used to detect ultra low concentrations of primordial actinides. Here it is utilized for the first time to detect primordial Th and U in ultra pure copper serving as shielding material in low level detectors. The lowest concentrations achieved were (1.5 ± 0.6) ·10-11 g/g for Th and (8 ± 4) ·10-14 g/g for U which corresponds to (59 ± 24) and (1.0 ± 0.5) μBq/kg, respectively.

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

    NASA Astrophysics Data System (ADS)

    Kieser, W. E.; Zhao, X.-L.; Eliades, J.; Litherland, A. E.

    2012-04-01

    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.

  15. Can-AMS: The New Accelerator Mass Spectrometry Facility At The University Of Ottawa

    SciTech Connect

    Kieser, W. E.; Zhao, X.-L.; Clark, I. D.; Kotzer, T.; Litherland, A. E.

    2011-06-01

    The Canadian Centre for Accelerator Mass Spectrometry (AMS) at the University of Ottawa will be equipped with a new, 3 MV tandem accelerator with peripheral equipment for the analysis of elements ranging from tritium to the actinides. This facility, along with a wide array of support instrumentation recently funded by the Canada Foundation for Innovation, will be located in a new science building on the downtown campus of the University of Ottawa. In addition to providing the standard AMS measurements on {sup 14}C, {sup 10}Be, {sup 26}Al, {sup 36}Cl and {sup 129}I for earth, environmental, cultural and biomedical sciences, this facility will incorporate the new technologies of anion isobar separation at low energies using RFQ chemical reaction cells for {sup 36}Cl and new heavy element applications, integrated sample combustion and gas ion source for biomedical and environmental {sup 14}C analysis and the use of novel target matrices for expanding the range of applicable elements and simplifying sample preparation, all currently being developed at IsoTrace. This paper will outline the design goals for the new facility, present some details of the new AMS technologies, in particular the Isobar Separator for Anions and discuss the design of the AMS system resulting from these requirements.

  16. Applying accelerator mass spectrometry for low-level detection of complex engineered nanoparticles in biological media.

    PubMed

    Wang, Binghui; Jackson, George S; Yokel, Robert A; Grulke, Eric A

    2014-08-01

    Complex engineered nanoparticles (CENPs), which have different core and surface components, are being developed for medicinal, pharmaceutical and industrial applications. One of the key challenges for environmental health and safety assessments of CENPs is to identify and quantity their transformations in biological environments. This study reports the effects of in vivo exposure of citrate-coated nanoalumina with different rare isotope labels on each component. This CENP was dosed to the rat and accelerator mass spectrometry (AMS) was used to quantify (26)Al, (14)C, and their ratio in the dosing material and tissue samples. For CENPs detected in the liver, the rare isotope ratio, (14)C/(26)Al, was 87% of the dosing material's ratio. The citrate coating on the nanoalumina in the liver was stable or, if it degraded, its metabolites were incorporated with nearby tissues. However, in brain and bone where little alumina was detected, the rare isotope ratio greatly exceeded that of the dosing material. Therefore, in the animal, citrate dissociated from CENPs and redistributed to brain and bone. Tracking both the core and surface components by AMS presents a new approach for characterizing transformations of CENPs components in biological milieu or environments.

  17. Determination of the stellar (n,γ) cross section of Ca40 with accelerator mass spectrometry

    NASA Astrophysics Data System (ADS)

    Dillmann, I.; Domingo-Pardo, C.; Heil, M.; Käppeler, F.; Wallner, A.; Forstner, O.; Golser, R.; Kutschera, W.; Priller, A.; Steier, P.; Mengoni, A.; Gallino, R.; Paul, M.; Vockenhuber, C.

    2009-06-01

    The stellar (n,γ) cross section of Ca40 at kT=25 keV has been measured with a combination of the activation technique and accelerator mass spectrometry (AMS). This combination is required when direct off-line counting of the produced activity is compromised by the long half-life and/or missing γ-ray transitions. The neutron activations were performed at the Karlsruhe Van de Graaff accelerator using the quasistellar neutron spectrum of kT=25 keV produced by the Li7(p,n)Be7 reaction. The subsequent AMS measurements were carried out at the Vienna Environmental Research Accelerator (VERA) with a 3 MV tandem accelerator. The doubly magic Ca40 is a bottle-neck isotope in incomplete silicon burning, and its neutron capture cross section determines the amount of leakage, thus impacting on the eventual production of iron group elements. Because of its high abundance, Ca40 can also play a secondary role as “neutron poison” for the s-process. Previous determinations of this value at stellar energies were based on time-of-flight measurements. Our method uses an independent approach, and yields for the Maxwellian-averaged cross section at kT=30 keV a value of <σ>30keV=5.73±0.34 mb.

  18. Thermal Hazard Evaluation of Cumene Hydroperoxide-Metal Ion Mixture Using DSC, TAM III, and GC/MS.

    PubMed

    You, Mei-Li

    2016-01-01

    Cumene hydroperoxide (CHP) is widely used in chemical processes, mainly as an initiator for the polymerization of acrylonitrile-butadiene-styrene. It is a typical organic peroxide and an explosive substance. It is susceptible to thermal decomposition and is readily affected by contamination; moreover, it has high thermal sensitivity. The reactor tank, transit storage vessel, and pipeline used for manufacturing and transporting this substance are made of metal. Metal containers used in chemical processes can be damaged through aging, wear, erosion, and corrosion; furthermore, the containers might release metal ions. In a metal pipeline, CHP may cause incompatibility reactions because of catalyzed exothermic reactions. This paper discusses and elucidates the potential thermal hazard of a mixture of CHP and an incompatible material's metal ions. Differential scanning calorimetry (DSC) and thermal activity monitor III (TAM III) were employed to preliminarily explore and narrate the thermal hazard at the constant temperature environment. The substance was diluted and analyzed by using a gas chromatography spectrometer (GC) and gas chromatography/mass spectrometer (GC/MS) to determine the effect of thermal cracking and metal ions of CHP. The thermokinetic parameter values obtained from the experiments are discussed; the results can be used for designing an inherently safer process. As a result, the paper finds that the most hazards are in the reaction of CHP with Fe(2+). When the metal release is exothermic in advance, the system temperature increases, even leading to uncontrollable levels, and the process may slip out of control. PMID:27136518

  19. Thermal Hazard Evaluation of Cumene Hydroperoxide-Metal Ion Mixture Using DSC, TAM III, and GC/MS.

    PubMed

    You, Mei-Li

    2016-04-28

    Cumene hydroperoxide (CHP) is widely used in chemical processes, mainly as an initiator for the polymerization of acrylonitrile-butadiene-styrene. It is a typical organic peroxide and an explosive substance. It is susceptible to thermal decomposition and is readily affected by contamination; moreover, it has high thermal sensitivity. The reactor tank, transit storage vessel, and pipeline used for manufacturing and transporting this substance are made of metal. Metal containers used in chemical processes can be damaged through aging, wear, erosion, and corrosion; furthermore, the containers might release metal ions. In a metal pipeline, CHP may cause incompatibility reactions because of catalyzed exothermic reactions. This paper discusses and elucidates the potential thermal hazard of a mixture of CHP and an incompatible material's metal ions. Differential scanning calorimetry (DSC) and thermal activity monitor III (TAM III) were employed to preliminarily explore and narrate the thermal hazard at the constant temperature environment. The substance was diluted and analyzed by using a gas chromatography spectrometer (GC) and gas chromatography/mass spectrometer (GC/MS) to determine the effect of thermal cracking and metal ions of CHP. The thermokinetic parameter values obtained from the experiments are discussed; the results can be used for designing an inherently safer process. As a result, the paper finds that the most hazards are in the reaction of CHP with Fe(2+). When the metal release is exothermic in advance, the system temperature increases, even leading to uncontrollable levels, and the process may slip out of control.

  20. The Role of TAM Family Receptors in Immune Cell Function: Implications for Cancer Therapy

    PubMed Central

    Paolino, Magdalena; Penninger, Josef M.

    2016-01-01

    The TAM receptor protein tyrosine kinases—Tyro3, Axl, and Mer—are essential regulators of immune homeostasis. Guided by their cognate ligands Growth arrest-specific gene 6 (Gas6) and Protein S (Pros1), these receptors ensure the resolution of inflammation by dampening the activation of innate cells as well as by restoring tissue function through promotion of tissue repair and clearance of apoptotic cells. Their central role as negative immune regulators is highlighted by the fact that deregulation of TAM signaling has been linked to the pathogenesis of autoimmune, inflammatory, and infectious diseases. Importantly, TAM receptors have also been associated with cancer development and progression. In a cancer setting, TAM receptors have a dual regulatory role, controlling the initiation and progression of tumor development and, at the same time, the associated anti-tumor responses of diverse immune cells. Thus, modulation of TAM receptors has emerged as a potential novel strategy for cancer treatment. In this review, we discuss our current understanding of how TAM receptors control immunity, with a particular focus on the regulation of anti-tumor responses and its implications for cancer immunotherapy. PMID:27775650

  1. Modeling the acceptance of clinical information systems among hospital medical staff: an extended TAM model.

    PubMed

    Melas, Christos D; Zampetakis, Leonidas A; Dimopoulou, Anastasia; Moustakis, Vassilis

    2011-08-01

    Recent empirical research has utilized the Technology Acceptance Model (TAM) to advance the understanding of doctors' and nurses' technology acceptance in the workplace. However, the majority of the reported studies are either qualitative in nature or use small convenience samples of medical staff. Additionally, in very few studies moderators are either used or assessed despite their importance in TAM based research. The present study focuses on the application of TAM in order to explain the intention to use clinical information systems, in a random sample of 604 medical staff (534 physicians) working in 14 hospitals in Greece. We introduce physicians' specialty as a moderator in TAM and test medical staff's information and communication technology (ICT) knowledge and ICT feature demands, as external variables. The results show that TAM predicts a substantial proportion of the intention to use clinical information systems. Findings make a contribution to the literature by replicating, explaining and advancing the TAM, whereas theory is benefited by the addition of external variables and medical specialty as a moderator. Recommendations for further research are discussed.

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

    PubMed

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

    2014-08-01

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

    PubMed

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

    2014-08-01

    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. PMID:25033319

  4. Accelerator Mass Spectrometry Allows for Cellular Quantification of Doxorubicin at Femtomolar Concentrations

    SciTech Connect

    DeGregorio, M W; Dingley, K H; Wurz, G T; Ubick, E; Turteltaub, K W

    2005-04-12

    Accelerator mass spectrometry (AMS) is a highly sensitive analytical methodology used to quantify the content of radioisotopes, such as {sup 14}C, in a sample. The primary goals of this work were to demonstrate the utility of AMS in determining cellular [{sup 14}C]doxorubicin (DOX) concentrations and to develop a sensitive assay that is superior to high performance liquid chromatography (HPLC) for the quantification of DOX at the tumor level. In order to validate the superior sensitivity of AMS versus HPLC with fluorescence detection, we performed three studies comparing the cellular accumulation of DOX: one in vitro cell line study, and two in vivo xenograft mouse studies. Using AMS, we quantified cellular DOX content up to 4 hours following in vitro exposure at concentrations ranging from 0.2 pg/ml (345 fM) to 2 {micro}g/ml (3.45 {micro}M) [{sup 14}C]DOX. The results of this study show that, compared to standard fluorescence-based HPLC, the AMS method was over five orders of magnitude more sensitive. Two in vivo studies compared the sensitivity of AMS to HPLC using a nude mouse xenograft model in which breast cancer cells were implanted subcutaneously. After sufficiently large tumors formed, DOX was administered intravenously at two dose levels. Additionally, we tested the AMS method in a nude mouse xenograft model of multidrug resistance (MDR) in which each mouse was implanted with both wild type and MDR+ cells on opposite flanks. The results of the second and third studies showed that DOX concentrations were significantly higher in the wild type tumors compared to the MDR+ tumors, consistent with the MDR model. The extreme sensitivity of AMS should facilitate similar studies in humans to establish target site drug delivery and to potentially determine the optimal treatment dose and regimen.

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

    NASA Astrophysics Data System (ADS)

    Garner, R. C.; 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 14C is of most interest to biomedical researchers but few studies have been reported using AMS in drug discovery and development. For biomedical use, 14C 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 14C 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 14C-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 14C-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).

  6. Accelerator mass spectrometry of iodine-129 and its applications in natural water systems

    NASA Astrophysics Data System (ADS)

    Buraglio, Nadia

    During recent decades, huge amount of radioactive waste has been dumped into the earth's surface environments. 129I (T1/2 = 15.6 My) is one of the radioactive products that has been produced through a variety of processes, including atomic weapon testing, reprocessing of nuclear fact and nuclear accidents. This thesis describes development of the Accelerator Mass Spectrometry (AMS) ultra-sensitive atom counting technique at Uppsala Tandem Laboratory to measure 129I and discusses investigations of its distribution in the hydrosphere (marine and fresh water) and precipitation. The AMS technique provides a method for measuring long-lived radioactive isotopes in small samples, relative to other conventional techniques, and thus opens a now line of research. The optimization of the AMS system at Uppsala included testing a time of flight detector, evaluation of the most appropriate charge-state, reduction of molecular interference and improvement of the detection limit. Furthermore, development of a chemical procedure for separation of iodine from natural water samples has been accomplished. The second part of the thesis reports investigations of 129I in natural waters and indicates that high concentrations of 129I (3-4 orders of magnitude higher than in the prenuclear era) are found in most of the considered natural waters. Inventory calculations and results of measurements suggest that the major sources of radioactive iodine are the two main European nuclear reprocessing facilities at Sellafield (U.K.) and La Hague (France). This information provides estimates of the transit time and vertical mixing of water masses in the central Arctic Ocean. Results from precipitation, lakes and runoff are used to elucidate mechanisms of transport of 129I from the point sources and its pathways in the hydrological environment. This study also shows the need for continuous monitoring of the 129I level in the hydrosphere and of its future variability.

  7. Measurement of Beryllium in Biological Samples by Accelerator Mass Spectrometry: Applications for Studying Chronic Beryllium Disease

    SciTech Connect

    Chiarappa-Zucca, M L; Finkel, R C; Martinelli, R E; McAninch, J E; Nelson, D O; Turtletaub, K W

    2004-04-15

    A method using accelerator mass spectrometry (AMS) has been developed for quantifying attomoles of beryllium (Be) in biological samples. This method provides the sensitivity to trace Be in biological samples at very low doses with the purpose of identifying the molecular targets involved in chronic beryllium disease. Proof of the method was tested by administering 0.001, 0.05, 0.5 and 5.0 {micro}g {sup 9}Be and {sup 10}Be by intraperitoneal injection to male mice and removing spleen, liver, femurs, blood, lung, and kidneys after 24 h exposure. These samples were prepared for AMS analysis by tissue digestion in nitric acid, followed by further organic oxidation with hydrogen peroxide and ammonium persulfate and lastly, precipitation of Be with ammonium hydroxide, and conversion to beryllium oxide at 800 C. The {sup 10}Be/{sup 9}Be ratio of the extracted beryllium oxide was measured by AMS and Be in the original sample was calculated. Results indicate that Be levels were dose-dependent in all tissues and the highest levels were measured in the spleen and liver. The measured {sup 10}Be/{sup 9}Be ratios spanned 4 orders of magnitude, from 10{sup -10} to 10{sup -14}, with a detection limit of 3.0 x 10{sup -14}, which is equivalent to 0.8 attomoles of {sup 10}Be. These results show that routine quantification of nanogram levels of Be in tissues is possible and that AMS is a sensitive method that can be used in biological studies to understand the molecular dosimetry of Be and mechanisms of toxicity.

  8. Actinide Measurements by Accelerator Mass Spectrometry at Lawrence Livermore National Laboratory

    SciTech Connect

    Brown, T A; Marchetti, A A; Martinelli, R E; Cox, C C; Knezovich, J P; Hamilton, T F

    2003-09-25

    We report on the development of an accelerator mass spectrometry (AMS) system for the measurement of actinides at Lawrence Livermore National Laboratory. This AMS system is centered on a recently completed heavy isotope beam line that was designed particularly for high sensitivity, robust, high-throughput measurements of actinide concentrations and isotopic ratios. A fast isotope switching capability has been incorporated in the system, allowing flexibility in isotope selection and for the quasi-continuous normalization to a reference isotope spike. Initially, our utilization of the heavy isotope system has concentrated on the measurement of Pu isotopes. Under current operating conditions, background levels equivalent to {approx}1 x 10{sup 5} atoms are observed during routine {sup 239}Pu and {sup 240}Pu measurements. Measurements of samples containing {approx}10{sup 13} {sup 238}U atoms demonstrate that the system provides a {sup 238}U rejection factor during {sup 239}Pu measurements of {approx}10{sup 7}. Measurements of known materials, combined with results from an externally organized inter-comparison program, indicate that our {sup 239}Pu measurements are accurate and precise down to the {micro}Bq level ({approx}10{sup 6} atoms). Recently, we have investigated the performance of our heavy isotope AMS system in measurements of {sup 237}Np and {sup 236}U. Results of these investigations are discussed. The sensitivity shown by our Pu measurements, combined with the high throughput and interference rejection capabilities of our AMS system, demonstrate that AMS can provide a rapid and cost-effective measurement technique for actinides in a wide variety of studies.

  9. SCINTILLATION SPECTROMETER

    DOEpatents

    Bell, P.R.; Francis, J.E.

    1960-06-21

    A portable scintillation spectrometer is described which is especially useful in radio-biological studies for determining the uptake and distribution of gamma -emitting substances in tissue. The spectrometer includes a collimator having a plurality of apertures that are hexagonal in cross section. Two crystals are provided: one is activated to respond to incident rays from the collimator; the other is not activated and shields the first from external radiation.

  10. Calcium Isolation from Large-Volume Human Urine Samples for 41Ca Analysis by Accelerator Mass Spectrometry

    PubMed Central

    Miller, James J; Hui, Susanta K; Jackson, George S; Clark, Sara P; Einstein, Jane; Weaver, Connie M; Bhattacharyya, Maryka H

    2013-01-01

    Calcium oxalate precipitation is the first step in preparation of biological samples for 41Ca analysis by accelerator mass spectrometry. A simplified protocol for large-volume human urine samples was characterized, with statistically significant increases in ion current and decreases in interference. This large-volume assay minimizes cost and effort and maximizes time after 41Ca administration during which human samples, collected over a lifetime, provide 41Ca:Ca ratios that are significantly above background. PMID:23672965

  11. Accelerator mass spectrometry detection of beryllium ions in the antigen processing and presentation pathway.

    PubMed

    Tooker, Brian C; Brindley, Stephen M; Chiarappa-Zucca, Marina L; Turteltaub, Kenneth W; Newman, Lee S

    2015-01-01

    Exposure to small amounts of beryllium (Be) can result in beryllium sensitization and progression to Chronic Beryllium Disease (CBD). In CBD, beryllium is presented to Be-responsive T-cells by professional antigen-presenting cells (APC). This presentation drives T-cell proliferation and pro-inflammatory cytokine (IL-2, TNFα, and IFNγ) production and leads to granuloma formation. The mechanism by which beryllium enters an APC and is processed to become part of the beryllium antigen complex has not yet been elucidated. Developing techniques for beryllium detection with enough sensitivity has presented a barrier to further investigation. The objective of this study was to demonstrate that Accelerator Mass Spectrometry (AMS) is sensitive enough to quantify the amount of beryllium presented by APC to stimulate Be-responsive T-cells. To achieve this goal, APC - which may or may not stimulate Be-responsive T-cells - were cultured with Be-ferritin. Then, by utilizing AMS, the amount of beryllium processed for presentation was determined. Further, IFNγ intracellular cytokine assays were performed to demonstrate that Be-ferritin (at levels used in the experiments) could stimulate Be-responsive T-cells when presented by an APC of the correct HLA type (HLA-DP0201). The results indicated that Be-responsive T-cells expressed IFNγ only when APC with the correct HLA type were able to process Be for presentation. Utilizing AMS, it was determined that APC with HLA-DP0201 had membrane fractions containing 0.17-0.59 ng Be and APC with HLA-DP0401 had membrane fractions bearing 0.40-0.45 ng Be. However, HLA-DP0401 APC had 20-times more Be associated with the whole cells (57.68-61.12 ng) than HLA-DP0201 APC (0.90-3.49 ng). As these findings demonstrate, AMS detection of picogram levels of Be processed by APC is possible. Further, regardless of form, Be requires processing by APC to successfully stimulate Be-responsive T-cells to generate IFNγ.

  12. Accelerator mass spectrometry detection of beryllium ions in the antigen processing and presentation pathway

    SciTech Connect

    Tooker, Brian C.; Brindley, Stephen M.; Chiarappa-Zucca, Marina L.; Turteltaub, Kenneth W.; Newman, Lee S.

    2014-06-16

    We report that exposure to small amounts of beryllium (Be) can result in beryllium sensitization and progression to Chronic Beryllium Disease (CBD). In CBD, beryllium is presented to Be-responsive T-cells by professional antigen-presenting cells (APC). This presentation drives T-cell proliferation and pro-inflammatory cytokine (IL-2, TNFα, and IFNγ) production and leads to granuloma formation. The mechanism by which beryllium enters an APC and is processed to become part of the beryllium antigen complex has not yet been elucidated. Developing techniques for beryllium detection with enough sensitivity has presented a barrier to further investigation. The objective of this study was to demonstrate that Accelerator Mass Spectrometry (AMS) is sensitive enough to quantify the amount of beryllium presented by APC to stimulate Be-responsive T-cells. To achieve this goal, APC - which may or may not stimulate Be-responsive T-cells - were cultured with Be-ferritin. Then, by utilizing AMS, the amount of beryllium processed for presentation was determined. Further, IFNγ intracellular cytokine assays were performed to demonstrate that Be-ferritin (at levels used in the experiments) could stimulate Be-responsive T-cells when presented by an APC of the correct HLA type (HLA-DP0201). The results indicated that Be-responsive T-cells expressed IFNγ only when APC with the correct HLA type were able to process Be for presentation. Utilizing AMS, we determined that APC with HLA-DP0201 had membrane fractions containing 0.17-0.59 ng Be and APC with HLA-DP0401 had membrane fractions bearing 0.40-0.45 ng Be. However, HLA-DP0401 APC had 20-times more Be associated with the whole cells (57.68-61.12 ng) then HLA-DP0201 APC (0.90-3.49 ng). As these findings demonstrate, AMS detection of picogram levels of Be processed by APC is possible. Further, regardless of form, Be requires processing by APC to successfully stimulate Be-responsive T-cells to generate IFNγ.

  13. Accelerator mass spectrometry detection of beryllium ions in the antigen processing and presentation pathway

    DOE PAGES

    Tooker, Brian C.; Brindley, Stephen M.; Chiarappa-Zucca, Marina L.; Turteltaub, Kenneth W.; Newman, Lee S.

    2014-06-16

    We report that exposure to small amounts of beryllium (Be) can result in beryllium sensitization and progression to Chronic Beryllium Disease (CBD). In CBD, beryllium is presented to Be-responsive T-cells by professional antigen-presenting cells (APC). This presentation drives T-cell proliferation and pro-inflammatory cytokine (IL-2, TNFα, and IFNγ) production and leads to granuloma formation. The mechanism by which beryllium enters an APC and is processed to become part of the beryllium antigen complex has not yet been elucidated. Developing techniques for beryllium detection with enough sensitivity has presented a barrier to further investigation. The objective of this study was to demonstratemore » that Accelerator Mass Spectrometry (AMS) is sensitive enough to quantify the amount of beryllium presented by APC to stimulate Be-responsive T-cells. To achieve this goal, APC - which may or may not stimulate Be-responsive T-cells - were cultured with Be-ferritin. Then, by utilizing AMS, the amount of beryllium processed for presentation was determined. Further, IFNγ intracellular cytokine assays were performed to demonstrate that Be-ferritin (at levels used in the experiments) could stimulate Be-responsive T-cells when presented by an APC of the correct HLA type (HLA-DP0201). The results indicated that Be-responsive T-cells expressed IFNγ only when APC with the correct HLA type were able to process Be for presentation. Utilizing AMS, we determined that APC with HLA-DP0201 had membrane fractions containing 0.17-0.59 ng Be and APC with HLA-DP0401 had membrane fractions bearing 0.40-0.45 ng Be. However, HLA-DP0401 APC had 20-times more Be associated with the whole cells (57.68-61.12 ng) then HLA-DP0201 APC (0.90-3.49 ng). As these findings demonstrate, AMS detection of picogram levels of Be processed by APC is possible. Further, regardless of form, Be requires processing by APC to successfully stimulate Be-responsive T-cells to generate IFNγ.« less

  14. The TAM receptor Mertk protects against neuroinvasive viral infection by maintaining blood-brain barrier integrity.

    PubMed

    Miner, Jonathan J; Daniels, Brian P; Shrestha, Bimmi; Proenca-Modena, Jose L; Lew, Erin D; Lazear, Helen M; Gorman, Matthew J; Lemke, Greg; Klein, Robyn S; Diamond, Michael S

    2015-12-01

    The TAM receptors Tyro3, Axl and Mertk are receptor tyrosine kinases that dampen host innate immune responses following engagement with their ligands Gas6 and Protein S, which recognize phosphatidylserine on apoptotic cells. In a form of apoptotic mimicry, many enveloped viruses display phosphatidylserine on the outer leaflet of their membranes, enabling TAM receptor activation and downregulation of antiviral responses. Accordingly, we hypothesized that a deficiency of TAM receptors would enhance antiviral responses and protect against viral infection. Unexpectedly, mice lacking Mertk and/or Axl, but not Tyro3, exhibited greater vulnerability to infection with neuroinvasive West Nile and La Crosse encephalitis viruses. This phenotype was associated with increased blood-brain barrier permeability, which enhanced virus entry into and infection of the brain. Activation of Mertk synergized with interferon-β to tighten cell junctions and prevent virus transit across brain microvascular endothelial cells. Because TAM receptors restrict pathogenesis of neuroinvasive viruses, these findings have implications for TAM antagonists that are currently in clinical development. PMID:26523970

  15. The TAM receptor Mertk protects against neuroinvasive viral infection by maintaining blood-brain barrier integrity.

    PubMed

    Miner, Jonathan J; Daniels, Brian P; Shrestha, Bimmi; Proenca-Modena, Jose L; Lew, Erin D; Lazear, Helen M; Gorman, Matthew J; Lemke, Greg; Klein, Robyn S; Diamond, Michael S

    2015-12-01

    The TAM receptors Tyro3, Axl and Mertk are receptor tyrosine kinases that dampen host innate immune responses following engagement with their ligands Gas6 and Protein S, which recognize phosphatidylserine on apoptotic cells. In a form of apoptotic mimicry, many enveloped viruses display phosphatidylserine on the outer leaflet of their membranes, enabling TAM receptor activation and downregulation of antiviral responses. Accordingly, we hypothesized that a deficiency of TAM receptors would enhance antiviral responses and protect against viral infection. Unexpectedly, mice lacking Mertk and/or Axl, but not Tyro3, exhibited greater vulnerability to infection with neuroinvasive West Nile and La Crosse encephalitis viruses. This phenotype was associated with increased blood-brain barrier permeability, which enhanced virus entry into and infection of the brain. Activation of Mertk synergized with interferon-β to tighten cell junctions and prevent virus transit across brain microvascular endothelial cells. Because TAM receptors restrict pathogenesis of neuroinvasive viruses, these findings have implications for TAM antagonists that are currently in clinical development.

  16. Development of Test-Analysis Models (TAM) for correlation of dynamic test and analysis results

    NASA Technical Reports Server (NTRS)

    Angelucci, Filippo; Javeed, Mehzad; Mcgowan, Paul

    1992-01-01

    The primary objective of structural analysis of aerospace applications is to obtain a verified finite element model (FEM). The verified FEM can be used for loads analysis, evaluate structural modifications, or design control systems. Verification of the FEM is generally obtained as the result of correlating test and FEM models. A test analysis model (TAM) is very useful in the correlation process. A TAM is essentially a FEM reduced to the size of the test model, which attempts to preserve the dynamic characteristics of the original FEM in the analysis range of interest. Numerous methods for generating TAMs have been developed in the literature. The major emphasis of this paper is a description of the procedures necessary for creation of the TAM and the correlation of the reduced models with the FEM or the test results. Herein, three methods are discussed, namely Guyan, Improved Reduced System (IRS), and Hybrid. Also included are the procedures for performing these analyses using MSC/NASTRAN. Finally, application of the TAM process is demonstrated with an experimental test configuration of a ten bay cantilevered truss structure.

  17. TAM receptors affect adult brain neurogenesis by negative regulation of microglial cell activation.

    PubMed

    Ji, Rui; Tian, Shifu; Lu, Helen J; Lu, Qingjun; Zheng, Yan; Wang, Xiaomin; Ding, Jixiang; Li, Qiutang; Lu, Qingxian

    2013-12-15

    TAM tyrosine kinases play multiple functional roles, including regulation of the target genes important in homeostatic regulation of cytokine receptors or TLR-mediated signal transduction pathways. In this study, we show that TAM receptors affect adult hippocampal neurogenesis and loss of TAM receptors impairs hippocampal neurogenesis, largely attributed to exaggerated inflammatory responses by microglia characterized by increased MAPK and NF-κB activation and elevated production of proinflammatory cytokines that are detrimental to neuron stem cell proliferation and neuronal differentiation. Injection of LPS causes even more severe inhibition of BrdU incorporation in the Tyro3(-/-)Axl(-/-)Mertk(-/-) triple-knockout (TKO) brains, consistent with the LPS-elicited enhanced expression of proinflammatory mediators, for example, IL-1β, IL-6, TNF-α, and inducible NO synthase, and this effect is antagonized by coinjection of the anti-inflammatory drug indomethacin in wild-type but not TKO brains. Conditioned medium from TKO microglia cultures inhibits neuron stem cell proliferation and neuronal differentiation. IL-6 knockout in Axl(-/-)Mertk(-/-) double-knockout mice overcomes the inflammatory inhibition of neurogenesis, suggesting that IL-6 is a major downstream neurotoxic mediator under homeostatic regulation by TAM receptors in microglia. Additionally, autonomous trophic function of the TAM receptors on the proliferating neuronal progenitors may also promote progenitor differentiation into immature neurons.

  18. Spectrometer gun

    DOEpatents

    Waechter, D.A.; Wolf, M.A.; Umbarger, C.J.

    1981-11-03

    A hand-holdable, battery-operated, microprocessor-based spectrometer gun is described that includes a low-power matrix display and sufficient memory to permit both real-time observation and extended analysis of detected radiation pulses. Universality of the incorporated signal processing circuitry permits operation with various detectors having differing pulse detection and sensitivity parameters.

  19. Spectrometer gun

    DOEpatents

    Waechter, David A.; Wolf, Michael A.; Umbarger, C. John

    1985-01-01

    A hand-holdable, battery-operated, microprocessor-based spectrometer gun includes a low-power matrix display and sufficient memory to permit both real-time observation and extended analysis of detected radiation pulses. Universality of the incorporated signal processing circuitry permits operation with various detectors having differing pulse detection and sensitivity parameters.

  20. HISS spectrometer

    SciTech Connect

    Greiner, D.E.

    1984-11-01

    This talk describes the Heavy Ion Spectrometer System (HISS) facility at the Lawrence Berkeley Laboratory's Bevalac. Three completed experiments and their results are illustrated. The second half of the talk is a detailed discussion of the response of drift chambers to heavy ions. The limitations of trajectory measurement over a large range in incident particle charge are presented.

  1. Resistance to gap repair of the transposon Tam3 in Antirrhinum majus: a role of the end regions.

    PubMed Central

    Yamashita, S; Takano-Shimizu, T; Kitamura, K; Mikami, T; Kishima, Y

    1999-01-01

    The extremely homogeneous organization of the transposon family Tam3 in Antirrhinum majus is in sharp contrast to the heterogeneity of the copies constituting many other transposon families. To address the issue of the Tam3 structural uniformity, we examined two possibilities: (1) recent invasion of Tam3 and (2) failure of gap repair, which is involved in conversion from autonomous forms to defective forms. The phylogenetic analysis of 17 Tam3 copies suggested that the invasion of Tam3 into the Antirrhinum genome occurred at least 5 mya, which is sufficiently long ago to have produced many aberrant copies by gap repair. Thus, we investigated gap repair events at the nivea(recurrens:Tam3) (niv(rec)::Tam3) allele, where Tam3 is actively excised. We show here that the gap repair of de novo somatic Tam3 excision was arrested immediately after initiation of the process. All of the identified gap repair products were short stretches, no longer than 150 bp from the ends. The Tam3 ends have hairpin structures with low free energies. We observed that the gap repair halted within the hairpin structure regions. Such small gap repair products appear to be distributed in the Antirrhinum genome, but are unlikely to be active. Our data strongly suggest that the structural homogeneity of Tam3 was caused by immunity to gap repair at the hairpins in both of the end regions. The frequency of extensive gap repair of de novo excision products in eukaryotic transposons was found to be correlated with the free energies of the secondary structures in the end regions. This fact suggests that the fates of transposon families might depend on the structures of their ends. PMID:10581294

  2. Investigating Students' Acceptance and Self-Efficacy of E-Learning at Al-Aqsa University Based on TAM Model

    ERIC Educational Resources Information Center

    Mahdi, Hasan Rebhi

    2014-01-01

    The study aimed at investigating the influence of E-learning Self-Efficacy (ELSE) on the acceptance of e-learning by using the Technology Acceptance Model (TAM). According to the TAM which used as the theoretical basis, both of the Perceived Usefulness (PU) and the Perceived Ease of Use (PEOU) influence directly the end user's Behavioral Intention…

  3. DETERMINING THE PHARMACOKINETICS AND LONG-TERM BIODISTRIBUTION OF SiO2 NANOPARTICLES IN VIVO USING ACCELERATOR MASS SPECTROMETRY

    PubMed Central

    Malfatti, Michael A.; Palko, Heather A.; Kuhn, Edward A.; Turteltaub, Kenneth W.

    2012-01-01

    Biodistribution is an important factor in better understanding silica dioxide nanoparticle (SiNP) safety. Currently, comprehensive studies on biodistribution are lacking, most likely due to the lack of suitable analytical methods. Accelerator mass spectrometry (AMS) was used to investigate the relationship between administered dose, PK, and long-term biodistribution of 14C-SiNPs in vivo. PK analysis showed that SiNPs were rapidly cleared from the central compartment, were distributed to tissues of the reticuloendothelial system, and persisted in the tissue over the 8-week time course, raising questions about the potential for bioaccumulation and associated long-term effects. PMID:23075393

  4. The Spectrometer

    NASA Astrophysics Data System (ADS)

    Greenslade, Thomas B.

    2012-03-01

    In the fall of 1999 I was shown an Ocean Optics spectrometer-in-the-computer at St. Patricks College at Maynooth, Ireland, and thought that I had seen heaven. Of course, it could not resolve the sodium D-lines (I had done that many years before with a homemade wire diffraction grating ), and I began to realize that inside was some familiar old technology. In this paper I would like to discuss its ancestors.

  5. The Spectrometer

    ERIC Educational Resources Information Center

    Greenslade, Thomas B., Jr.

    2012-01-01

    In the fall of 1999 I was shown an Ocean Optics spectrometer-in-the-computer at St. Patricks College at Maynooth, Ireland, and thought that I had seen heaven. Of course, it could not resolve the sodium D-lines (I had done that many years before with a homemade wire diffraction grating), and I began to realize that inside was some familiar old…

  6. Extended TAM Model: Impacts of Convenience on Acceptance and Use of Moodle

    ERIC Educational Resources Information Center

    Hsu, Hsiao-hui; Chang, Yu-ying

    2013-01-01

    The increasing online access to courses, programs, and information has shifted the control and responsibility of learning process from instructors to learners. Learners' perceptions of and attitudes toward e-learning constitute a critical factor to the success of such system. The purpose of this study is to take TAM (technology acceptance model)…

  7. Photophoretic spectrometer

    SciTech Connect

    Arnold, S.; Amani, Y.; Orenstein, A.

    1980-09-01

    An instrument is described which measures the spectral dependence of the radiometric (photophoretic) force on a micron-sized particle in a static configuration. This spectrometer consists of a servo-stabilized Millikan chamber which can be used as a photophoretic balance over the spectral range from 200 nm to 1000 nm. Spectra may be taken in a vacuum as small as 10/sup -4/ torr. The action spectrum of the photophoretic force on a crystallite of CdS is used as an example. The pressure dependence of the force at 500 nm is consistant with a radiometric mechanism.

  8. MASS SPECTROMETER

    DOEpatents

    White, F.A.

    1960-08-23

    A mass spectrometer is designed with a first adjustable magnetic field for resolving an ion beam into beams of selected masses, a second adjustable magnetic field for further resolving the ion beam from the first field into beams of selected masses, a thin foil disposed in the path of the beam between the first and second magnets to dissociate molecular ions incident thereon, an electrostatic field for further resolving the ion beam from the second field into beams of selected masses, and a detector disposed adjacent to the electrostatic field to receive the ion beam.

  9. TAM 304 wheat – Adapted to the adequate rainfall or high-input irrigation production system in the Southern Great Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    TAM 304 wheat is a medium-early hard red winter wheat. It is a great dryland or semi-irrigated wheat. TAM 304 performs best under adequate rainfall, limited irrigation, or irrigation, but does not perform as well under extended drought. TAM 304 performs exceptionally well under foliar disease pressu...

  10. Genetic diversity and phylogenetic analysis of Tams1 of Theileria annulata isolates from three continents between 2000 and 2012.

    PubMed

    Wang, Jiay; Yang, Xianyong; Wang, Yuge; Jing, Zhihong; Meng, Kai; Liu, Jianzhu; Guo, Huijun; Xu, Ruixue; Cheng, Ziqiang

    2014-01-01

    Theileria annulata, which is part of the Theileria sergenti/Theileria buffeli/Theileria orientalis group, preferentially infects cattle and results in high mortality and morbidity in the Mediterranean, Middle East, and Central Asia. The polypeptide Tams1 is an immunodominant major merozoite piroplasm surface antigen of T. annulata that could be used as a marker for epidemiological studies and phylogenetic analysis. In the present study, a total of 155 Tams1 sequences were investigated for genetic diversity and phylogenetic relationships through phylogenetic analysis. Results showed that the Tams1 sequences were divided into two major groups and that distribution for some isolates also exhibited geographic specificity. As targeting polymorphic genes for parasite detection may result in underestimation of infection, polymerase chain reaction (PCR) assay using two different probes targeting tams-1 genes of these two groups can be more credible. In addition, the direction of the spread of the disease was discovered to be from the Mediterranean or the tropical zone to the Eurasian peninsula, Middle East, Southern Asia, and Africa, particularly for Group 2. A similar occurrence was also found between the Ms1 gene of Theileria lestoquardi and the Tams1 gene of T. annulata, which explains cross-immunogenicity to a certain extent. However, no potential glycosylation site in the Tams1 of T. annulata was found in this study, which illustrated that instead of N-glycosylation, other modifications have more significant effects on the immunogenicity of the Tams1 protein.

  11. Measurement of the half-life of /sup 60/Fe using the Argonne FN tandem-superconducting Linac system as an accelerator mass spectrometer

    SciTech Connect

    Kutschera, W.; Billquist, P.J.; Frekers, D.

    1983-01-01

    An experiment to improve the accuracy in the half-life value of /sup 60/Fe by measuring both the amount of /sup 60/Fe nuclei and the decay-rate of a spallation produced sample using the relation dN/dt = -lambda N is briefly discussed. (WHK)

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

    SciTech Connect

    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.

  13. Accurate determination of ⁴¹Ca concentrations in spent resins from the nuclear industry by accelerator mass spectrometry.

    PubMed

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

    2013-12-01

    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 CaF2 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. PMID:24144617

  14. AN INTEGRAL REACTOR PHYSICS EXPERIMENT TO INFER ACTINIDE CAPTURE CROSS-SECTIONS FROM THORIUM TO CALIFORNIUM WITH ACCELERATOR MASS SPECTROMETRY

    SciTech Connect

    G. Youinou; M. Salvatores; M. Paul; R. Pardo; G. Palmiotti; F. Kondev; G. Imel

    2010-04-01

    The principle of the proposed experiment is to irradiate very pure actinide samples in the Advanced Test Reactor (ATR) at INL and, after a given time, determine the amount of the different transmutation products. The determination of the nuclide densities before and after neutron irradiation will allow inference of effective neutron capture cross-sections. This approach has been used in the past and the novelty of this experiment is that the atom densities of the different transmutation products will be determined using the Accelerator Mass Spectroscopy (AMS) technique at the ATLAS facility located at ANL. It is currently planned to irradiate the following isotopes: 232Th, 235U, 236U, 238U, 237Np, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, 241Am, 243Am and 248Cm.

  15. Understanding intention to use electronic information resources: A theoretical extension of the technology acceptance model (TAM).

    PubMed

    Tao, Donghua

    2008-11-06

    This study extended the Technology Acceptance Model (TAM) by examining the roles of two aspects of e-resource characteristics, namely, information quality and system quality, in predicting public health students' intention to use e-resources for completing research paper assignments. Both focus groups and a questionnaire were used to collect data. Descriptive analysis, data screening, and Structural Equation Modeling (SEM) techniques were used for data analysis. The study found that perceived usefulness played a major role in determining students' intention to use e-resources. Perceived usefulness and perceived ease of use fully mediated the impact that information quality and system quality had on behavior intention. The research model enriches the existing technology acceptance literature by extending TAM. Representing two aspects of e-resource characteristics provides greater explanatory information for diagnosing problems of system design, development, and implementation.

  16. The TAM family: phosphatidylserine sensing receptor tyrosine kinases gone awry in cancer.

    PubMed

    Graham, Douglas K; DeRyckere, Deborah; Davies, Kurtis D; Earp, H Shelton

    2014-12-01

    The TYRO3, AXL (also known as UFO) and MERTK (TAM) family of receptor tyrosine kinases (RTKs) are aberrantly expressed in multiple haematological and epithelial malignancies. Rather than functioning as oncogenic drivers, their induction in tumour cells predominately promotes survival, chemoresistance and motility. The unique mode of maximal activation of this RTK family requires an extracellular lipid–protein complex. For example, the protein ligand, growth arrest-specific protein 6 (GAS6), binds to phosphatidylserine (PtdSer) that is externalized on apoptotic cell membranes, which activates MERTK on macrophages. This triggers engulfment of apoptotic material and subsequent anti-inflammatory macrophage polarization. In tumours, autocrine and paracrine ligands and apoptotic cells are abundant, which provide a survival signal to the tumour cell and favour an anti-inflammatory, immunosuppressive microenvironment. Thus, TAM kinase inhibition could stimulate antitumour immunity, reduce tumour cell survival, enhance chemosensitivity and diminish metastatic potential. PMID:25568918

  17. TAM receptor tyrosine kinases: Expression, disease and oncogenesis in the central nervous system

    PubMed Central

    Pierce, Angela M.; Keating, Amy K.

    2014-01-01

    Receptor tyrosine kinases (RTKs) are cell surface proteins that tightly regulate a variety of downstream intra-cellular processes; ligand-receptor interactions result in cascades of signaling events leading to growth, proliferation, differentiation and migration. There are 58 described RTKs, which are further categorized into 20 different RTK families. When dysregulated or overexpressed, these RTKs are implicated in disordered growth, development, and oncogenesis. The TAM family of RTKs, consisting of Tyro3, Axl, and MerTK, is prominently expressed during the development and function of the central nervous system (CNS). Aberrant expression and dysregulated activation of TAM family members has been demonstrated in a variety of CNS-related disorders and diseases, including the most common but least treatable brain cancer in children and adults: glioblastoma multiforme. PMID:24184575

  18. The TAM family: phosphatidylserine sensing receptor tyrosine kinases gone awry in cancer.

    PubMed

    Graham, Douglas K; DeRyckere, Deborah; Davies, Kurtis D; Earp, H Shelton

    2014-12-01

    The TYRO3, AXL (also known as UFO) and MERTK (TAM) family of receptor tyrosine kinases (RTKs) are aberrantly expressed in multiple haematological and epithelial malignancies. Rather than functioning as oncogenic drivers, their induction in tumour cells predominately promotes survival, chemoresistance and motility. The unique mode of maximal activation of this RTK family requires an extracellular lipid–protein complex. For example, the protein ligand, growth arrest-specific protein 6 (GAS6), binds to phosphatidylserine (PtdSer) that is externalized on apoptotic cell membranes, which activates MERTK on macrophages. This triggers engulfment of apoptotic material and subsequent anti-inflammatory macrophage polarization. In tumours, autocrine and paracrine ligands and apoptotic cells are abundant, which provide a survival signal to the tumour cell and favour an anti-inflammatory, immunosuppressive microenvironment. Thus, TAM kinase inhibition could stimulate antitumour immunity, reduce tumour cell survival, enhance chemosensitivity and diminish metastatic potential.

  19. Dynamic Simulation of 1D Cellular Automata in the Active aTAM

    PubMed Central

    Jonoska, Nataša; Karpenko, Daria; Seki, Shinnosuke

    2016-01-01

    The Active aTAM is a tile based model for self-assembly where tiles are able to transfer signals and change identities according to the signals received. We extend Active aTAM to include deactivation signals and thereby allow detachment of tiles. We show that the model allows a dynamic simulation of cellular automata with assemblies that do not record the entire computational history but only the current updates of the states, and thus provide a way for (a) algorithmic dynamical structural changes in the assembly and (b) reusable space in self-assembly. The simulation is such that at a given location the sequence of tiles that attach and detach corresponds precisely to the sequence of states the synchronous cellular automaton generates at that location.

  20. The Tyrosine Aminomutase TAM1 Is Required for β-Tyrosine Biosynthesis in Rice

    PubMed Central

    Yan, Jian; Aboshi, Takako; Teraishi, Masayoshi; Strickler, Susan R.; Spindel, Jennifer E.; Tung, Chih-Wei; Takata, Ryo; Matsumoto, Fuka; Maesaka, Yoshihiro; McCouch, Susan R.; Okumoto, Yutaka; Mori, Naoki; Jander, Georg

    2015-01-01

    Non-protein amino acids, often isomers of the standard 20 protein amino acids, have defense-related functions in many plant species. A targeted search for jasmonate-induced metabolites in cultivated rice (Oryza sativa) identified (R)-β-tyrosine, an isomer of the common amino acid (S)-α-tyrosine in the seeds, leaves, roots, and root exudates of the Nipponbare cultivar. Assays with 119 diverse cultivars showed a distinct presence/absence polymorphism, with β-tyrosine being most prevalent in temperate japonica cultivars. Genetic mapping identified a candidate gene on chromosome 12, which was confirmed to encode a tyrosine aminomutase (TAM1) by transient expression in Nicotiana benthamiana and in vitro enzyme assays. A point mutation in TAM1 eliminated β-tyrosine production in Nipponbare. Rice cultivars that do not produce β-tyrosine have a chromosome 12 deletion that encompasses TAM1. Although β-tyrosine accumulation was induced by the plant defense signaling molecule jasmonic acid, bioassays with hemipteran and lepidopteran herbivores showed no negative effects at physiologically relevant β-tyrosine concentrations. In contrast, root growth of Arabidopsis thaliana and other tested dicot plants was inhibited by concentrations as low as 1 μM. As β-tyrosine is exuded into hydroponic medium at higher concentrations, it may contribute to the allelopathic potential of rice. PMID:25901084

  1. Growth Arrest-Specific 6 (Gas6) and TAM Receptors in Mouse Platelets

    PubMed Central

    Uras, Fikriye; Küçük, Burhanettin; Bingöl Özakpınar, Özlem; Demir, Ahmet Muzaffer

    2015-01-01

    Objective: Growth arrest-specific 6 (Gas6) is a newly discovered vitamin K-dependent protein, which is a ligand for TAM receptors [Tyro3 (Sky), Axl, and Mer] from the tyrosine kinase family. Gas6 knockout mice were resistant to venous and arterial thrombosis. There are contradictory reports on the presence of Gas6 and its receptors in mouse platelets. The objective of this study was to investigate whether Gas6 and its receptors were present in mouse platelets or not. Materials and Methods: Specific pathogen-free BALB/c male and female mice of 8-10 weeks old and 25-30 g in weight were anesthetized under light ether anesthesia and blood samples were taken from their hearts. RNAs were isolated from isolated platelets, and then mRNAs encoding Gas6 and TAM receptors were detected by reverse transcription-polymerase chain reaction (RT-PCR). Protein concentrations of Gas6 and TAM receptors in platelets were measured by ELISA, but not those of Mer, because of the absence of any commercial ELISA kit for mouse specimens. Results: RT-PCR results indicated the presence of mRNAs encoding Gas6 and Mer in mouse platelets. However, although RT-PCR reactions were performed at various temperatures and cycles, we could not detect the presence of mRNAs encoding Axl and Tyro3 (Sky). Receptor protein levels of Axl and Tyro3 were below the detection limits of the ELISA method. Conclusion: We found the presence of mRNAs encoding Gas6 and the receptor Mer in mouse platelets, but not Axl and Tyro3. Gas6, Axl, and Tyro3 protein levels were below the detection limits of the ELISA. The presence of mRNA is not obvious evidence of protein expression in platelets that have no nucleus or DNA. Further studies are required to clarify the presence of Gas6/TAM receptors in platelets using real-time PCR and more sensitive immunological methods, and future studies on mechanisms will indicate whether the Gas6/TAM pathway is a strategy for treatment of disorders. PMID:25805676

  2. The André E. Lalonde AMS Laboratory - The new accelerator mass spectrometry facility at the University of Ottawa

    NASA Astrophysics Data System (ADS)

    Kieser, W. E.; Zhao, X.-L.; Clark, I. D.; Cornett, R. J.; Litherland, A. E.; Klein, M.; Mous, D. J. W.; Alary, J.-F.

    2015-10-01

    The University of Ottawa, Canada, has installed a multi-element, 3 MV tandem AMS system as the cornerstone of their new Advanced Research Complex and the principal analytical instrument of the André E. Lalonde Accelerator Mass Spectrometry Laboratory. Manufactured by High Voltage Engineering Europa B.V., the Netherlands, it is equipped with a 200 sample ion source, a high resolution, 120° injection magnet, a 90° high energy analysis magnet (mass-energy product 350 MeV-AMU), a 65°, 1.7 m radius electric analyzer and a 2 channel gas ionization detector. It is designed to analyze isotopes ranging from tritium to the actinides and to accommodate the use of fluoride target materials. This system is being extended with a second injection line, consisting of selected components from the IsoTrace Laboratory, University of Toronto. This line will contain a pre-commercial version of the Isobar Separator for Anions, manufactured by Isobarex Corp., Bolton, Ontario, Canada. This instrument uses selective ion-gas reactions in a radio-frequency quadrupole cell to attenuate both atomic and molecular isobars. This paper discusses the specifications of the new AMS equipment, reports on the acceptance test results for 10Be, 14C, 26Al and 127I and presents typical spectra for 10Be and actinide analyses.

  3. Isolation of Pu-isotopes from environmental samples using ion chromatography for accelerator mass spectrometry and alpha spectrometry.

    PubMed

    Chamizo, E; Jiménez-Ramos, M C; Wacker, L; Vioque, I; Calleja, A; García-León, M; García-Tenorio, R

    2008-01-14

    A radiochemical method for the isolation of plutonium-isotopes from environmental samples, based on the use of specific extraction chromatography resins for actinides (TEVA), Eichrom Industries, Inc.), has been set up in our laboratory and optimised for their posterior determination by alpha spectrometry (AS) or accelerator mass spectrometry (AMS). The proposed radiochemical method has replaced in our lab a well-established one based on the use of a relatively un-specific anion-exchange resin (AG) 1X8, Bio-rad Laboratories, Inc.), because it is clearly less time consuming, reduces the amounts and molarities of acid wastes produced, and reproducibly gives high radiochemical yields. In order to check the reliability of the proposed radiochemical method for the determination of plutonium-isotopes in different environmental matrixes, twin aliquots of a set of samples were prepared with TEVA and with AG 1X8 resins and measured by AS. Some samples prepared with TEVA resins were measured as well by AMS. As it is shown in the text, there is a comfortable agreement between AS and AMS, which adequately validates the method. PMID:18082656

  4. Calorimetric low temperature detectors for low-energetic heavy ions and their application in accelerator mass spectrometry

    NASA Astrophysics Data System (ADS)

    Kraft-Bermuth, S.; Andrianov, V. A.; Bleile, A.; Echler, A.; Egelhof, P.; Kiseleva, A.; Kiselev, O.; Meier, H. J.; Meier, J. P.; Shrivastava, A.; Weber, M.; Golser, R.; Kutschera, W.; Priller, A.; Steier, P.; Vockenhuber, C.

    2009-10-01

    The energy-sensitive detection of heavy ions with calorimetric low temperature detectors was investigated in the energy range of E =0.1-1 MeV/amu, commonly used for accelerator mass spectrometry (AMS). The detectors used consist of sapphire absorbers and superconducting aluminum transition edge thermometers operated at T ˜1.5 K. They were irradiated with various ion beams (C13,A197u,U238) provided by the VERA tandem accelerator in Vienna, Austria. The relative energy resolution obtained was ΔE /E=(5-9)×10-3, even for the heaviest ions such as U238. In addition, no evidence for a pulse height defect was observed. This performance allowed for the first time to apply a calorimetric low temperature detector in an AMS experiment. The aim was to precisely determine the isotope ratio of U236/U238 for several samples of natural uranium, U236 being known as a sensitive monitor for neutron fluxes. Replacing a conventionally used detection system at VERA by the calorimetric detector enabled to substantially reduce background from neighboring isotopes and to increase the detection efficiency. Due to the high sensitivity achieved, a value of U236/U238=6.1×10-12 could be obtained, representing the smallest U236/U238 ratio measured at the time. In addition, we contributed to establishing an improved material standard of U236/U238, which can be used as a reference for future AMS measurements.

  5. A Novel 14C-Postlabeling Assay Using Accelerator Mass Spectrometry For the Detection of O6-Methyldeoxyguanosine Adducts

    SciTech Connect

    Thompkins, E M; Farmer, P B; Lamb, J H; Jukes, R; Dingley, K; Ubick, E A; Turteltaub, K W; Martin, E A; Brown, K

    2005-11-17

    Accelerator mass spectrometry (AMS) is currently one of the most sensitive methods available for the trace detection of DNA adducts and is particularly valuable for measuring adducts in humans or animal models. However, the standard approach requires administration of a radiolabeled compound. As an alternative, we have developed a preliminary {sup 14}C-postlabeling assay for detection of the highly mutagenic O{sup 6}-MedG, by AMS. Procedures were developed for derivatizing O{sup 6}-MedG using unlabeled acetic anhydride. Using conventional LC-MS analysis, the limit of detection for the major product, triacetylated O{sup 6}-MedG, was 10 fmoles. On reaction with {sup 14}C-acetic anhydride, using a specially designed enclosed system, the predominant product was {sup 14}C-di-acetyl O{sup 6}-MedG. This change in reaction profile was due to a modification of the reaction procedure, introduced as a necessary safety precaution. The limit of detection for {sup 14}C-diacetyl O{sup 6}-MedG by AMS was determined as 79 attomoles, {approx}18,000 fold lower than that achievable by LSC. Although the assay has so far only been carried out with labeled standards, the degree of sensitivity obtained illustrates the potential of this assay for measuring O{sup 6}-MedG levels in humans.

  6. Isolation of Pu-isotopes from environmental samples using ion chromatography for accelerator mass spectrometry and alpha spectrometry.

    PubMed

    Chamizo, E; Jiménez-Ramos, M C; Wacker, L; Vioque, I; Calleja, A; García-León, M; García-Tenorio, R

    2008-01-14

    A radiochemical method for the isolation of plutonium-isotopes from environmental samples, based on the use of specific extraction chromatography resins for actinides (TEVA), Eichrom Industries, Inc.), has been set up in our laboratory and optimised for their posterior determination by alpha spectrometry (AS) or accelerator mass spectrometry (AMS). The proposed radiochemical method has replaced in our lab a well-established one based on the use of a relatively un-specific anion-exchange resin (AG) 1X8, Bio-rad Laboratories, Inc.), because it is clearly less time consuming, reduces the amounts and molarities of acid wastes produced, and reproducibly gives high radiochemical yields. In order to check the reliability of the proposed radiochemical method for the determination of plutonium-isotopes in different environmental matrixes, twin aliquots of a set of samples were prepared with TEVA and with AG 1X8 resins and measured by AS. Some samples prepared with TEVA resins were measured as well by AMS. As it is shown in the text, there is a comfortable agreement between AS and AMS, which adequately validates the method.

  7. Analyzing Nuclear Fuel Cycles from Isotopic Ratios of Waste Products Applicable to Measurement by Accelerator Mass Spectrometry

    SciTech Connect

    Biegalski, S R; Whitney, S M; Buchholz, B

    2005-08-24

    An extensive study was conducted to determine isotopic ratios of nuclides in spent fuel that may be utilized to reveal historical characteristics of a nuclear reactor cycle. This forensic information is important to determine the origin of unknown nuclear waste. The distribution of isotopes in waste products provides information about a nuclear fuel cycle, even when the isotopes of uranium and plutonium are removed through chemical processing. Several different reactor cycles of the PWR, BWR, CANDU, and LMFBR were simulated for this work with the ORIGEN-ARP and ORIGEN 2.2 codes. The spent fuel nuclide concentrations of these reactors were analyzed to find the most informative isotopic ratios indicative of irradiation cycle length and reactor design. Special focus was given to long-lived and stable fission products that would be present many years after their creation. For such nuclides, mass spectrometry analysis methods often have better detection limits than classic gamma-ray spectroscopy. The isotopic ratios {sup 151}Sm/{sup 146}Sm, {sup 149}Sm/{sup 146}Sm, and {sup 244}Cm/{sup 246}Cm were found to be good indicators of fuel cycle length and are well suited for analysis by accelerator mass spectroscopy.

  8. Laser Ablation - Accelerator Mass Spectrometry: An Approach for Rapid Radiocarbon Analyses of Carbonate Archives at High Spatial Resolution.

    PubMed

    Welte, Caroline; Wacker, Lukas; Hattendorf, Bodo; Christl, Marcus; Fohlmeister, Jens; Breitenbach, Sebastian F M; Robinson, Laura F; Andrews, Allen H; Freiwald, André; Farmer, Jesse R; Yeman, Christiane; Synal, Hans-Arno; Günther, Detlef

    2016-09-01

    A new instrumental setup, combining laser ablation (LA) with accelerator mass spectrometry (AMS), has been investigated for the online radiocarbon ((14)C) analysis of carbonate records. Samples were placed in an in-house designed LA-cell, and CO2 gas was produced by ablation using a 193 nm ArF excimer laser. The (14)C/(12)C abundance ratio of the gas was then analyzed by gas ion source AMS. This configuration allows flexible and time-resolved acquisition of (14)C profiles in contrast to conventional measurements, where only the bulk composition of discrete samples can be obtained. Three different measurement modes, i.e. discrete layer analysis, survey scans, and precision scans, were investigated and compared using a stalagmite sample and, subsequently, applied to terrestrial and marine carbonates. Depending on the measurement mode, a precision of typically 1-5% combined with a spatial resolution of 100 μm can be obtained. Prominent (14)C features, such as the atomic bomb (14)C peak, can be resolved by scanning several cm of a sample within 1 h. Stalagmite, deep-sea coral, and mollusk shell samples yielded comparable signal intensities, which again were comparable to those of conventional gas measurements. The novel LA-AMS setup allowed rapid scans on a variety of sample materials with high spatial resolution. PMID:27396439

  9. Laser Ablation - Accelerator Mass Spectrometry: An Approach for Rapid Radiocarbon Analyses of Carbonate Archives at High Spatial Resolution.

    PubMed

    Welte, Caroline; Wacker, Lukas; Hattendorf, Bodo; Christl, Marcus; Fohlmeister, Jens; Breitenbach, Sebastian F M; Robinson, Laura F; Andrews, Allen H; Freiwald, André; Farmer, Jesse R; Yeman, Christiane; Synal, Hans-Arno; Günther, Detlef

    2016-09-01

    A new instrumental setup, combining laser ablation (LA) with accelerator mass spectrometry (AMS), has been investigated for the online radiocarbon ((14)C) analysis of carbonate records. Samples were placed in an in-house designed LA-cell, and CO2 gas was produced by ablation using a 193 nm ArF excimer laser. The (14)C/(12)C abundance ratio of the gas was then analyzed by gas ion source AMS. This configuration allows flexible and time-resolved acquisition of (14)C profiles in contrast to conventional measurements, where only the bulk composition of discrete samples can be obtained. Three different measurement modes, i.e. discrete layer analysis, survey scans, and precision scans, were investigated and compared using a stalagmite sample and, subsequently, applied to terrestrial and marine carbonates. Depending on the measurement mode, a precision of typically 1-5% combined with a spatial resolution of 100 μm can be obtained. Prominent (14)C features, such as the atomic bomb (14)C peak, can be resolved by scanning several cm of a sample within 1 h. Stalagmite, deep-sea coral, and mollusk shell samples yielded comparable signal intensities, which again were comparable to those of conventional gas measurements. The novel LA-AMS setup allowed rapid scans on a variety of sample materials with high spatial resolution.

  10. Exploring the Intrinsic Motivation of Hedonic Information Systems Acceptance: Integrating Hedonic Theory and Flow with TAM

    NASA Astrophysics Data System (ADS)

    Wang, Zhihuan

    Research on Information Systems (IS) acceptance is substantially focused on extrinsic motivation in workplaces, little is known about the underlying intrinsic motivations of Hedonic IS (HIS) acceptance. This paper proposes a hybrid HIS acceptance model which takes the unique characteristics of HIS and multiple identities of a HIS user into consideration by interacting Hedonic theory, Flow theory with Technology Acceptance Model (TAM). The model was empirically tested by a field survey. The result indicates that emotional responses, imaginal responses, and flow experience are three main contributions of HIS acceptance.

  11. Use of an intravenous microdose of 14C-labeled drug and accelerator mass spectrometry to measure absolute oral bioavailability in dogs; cross-comparison of assay methods by accelerator mass spectrometry and liquid chromatography-tandem mass spectrometry.

    PubMed

    Miyaji, Yoshihiro; Ishizuka, Tomoko; Kawai, Kenji; Hamabe, Yoshimi; Miyaoka, Teiji; Oh-hara, Toshinari; Ikeda, Toshihiko; Kurihara, Atsushi

    2009-01-01

    A technique utilizing simultaneous intravenous microdosing of (14)C-labeled drug with oral dosing of non-labeled drug for measurement of absolute bioavailability was evaluated using R-142086 in male dogs. Plasma concentrations of R-142086 were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and those of (14)C-R-142086 were measured by accelerator mass spectrometry (AMS). The absence of metabolites in the plasma and urine was confirmed by a single radioactive peak of the parent compound in the chromatogram after intravenous microdosing of (14)C-R-142086 (1.5 microg/kg). Although plasma concentrations of R-142086 determined by LC-MS/MS were approximately 20% higher than those of (14)C-R-142086 as determined by AMS, there was excellent correlation (r=0.994) between both concentrations after intravenous dosing of (14)C-R-142086 (0.3 mg/kg). The oral bioavailability of R-142086 at 1 mg/kg obtained by simultaneous intravenous microdosing of (14)C-R-142086 was 16.1%, this being slightly higher than the value (12.5%) obtained by separate intravenous dosing of R-142086 (0.3 mg/kg). In conclusion, on utilizing simultaneous intravenous microdosing of (14)C-labeled drug in conjunction with AMS analysis, absolute bioavailability could be approximately measured in dogs, but without total accuracy. Bioavailability in humans may possibly be approximately measured at an earlier stage and at a lower cost. PMID:19430168

  12. Preparation and characterization of TAM-loaded HPMC/PAN composite fibers for improving drug-release profiles.

    PubMed

    Shen, Xiaxia; Yu, Dengguang; Zhang, Xiaofei; Branford-White, Christopher; Zhu, Limin

    2011-01-01

    The present paper reports the preparation and characterization of composite hydroxypropyl methylcellulose/polyacrylonitrile (HPMC/PAN)-medicated fibers via a wet spinning technique. Tamoxifen (TAM) was selected as a model drug. Numerous analyses were conducted to characterize the mechanical, structure and morphology properties of the composite fibers. The drug content and in vitro dissolution behavior were also investigated. SEM images showed that the TAM-loaded HPMC/PAN composite fibers had a finger-like outer skin and a porous structure. FT-IR spectra demonstrated that there was a good compatibility between polymer and drug. Results from X-ray diffraction and DSC suggested that most of the incorporated TAM was evenly distributed in the fiber matrix in an amorphous state, except for a minority that aggregated on the surface of fibers. The drug content in the fibers was lower than that in the spinning solution and about 10% of TAM was lost during spinning process. In vitro dissolution results indicated that, compared to TAM-PAN fibers, HPMC/PAN composite systems had weaker initial burst release effects and more drug-loading. The combination of hydrophilic polymer HPMC with PAN could improve the performance of polymer matrix composite fibers in regulating the drug-release profiles.

  13. Measurement of plutonium and other actinide elements at the center for accelerator mass spectrometry: a comparative assessments of competing techniques

    SciTech Connect

    Hamilton, T H; McAninch, J

    1999-02-01

    initiatives. One potential measurement technique for meeting these requirements is accelerator mass spectrometry (AMS). AMS is a widely accepted analytical technique for measurement of isotopes such as 14 C, 26 Al, 36 Cl (Vogel et al., 1995) but has only recently been demonstrated for the quantitative detection of actinides (Fifield et al., 1996). The Center for Accelerator Mass Spectrometry (CAMS) at the Lawrence Livermore National Laboratory (LLNL) operates the most versatile and most productive AMS instrument in the world (Roberts et al., 1996). The addition of a Heavy Ion Beamline and associated hardware for actinide detection are in an advanced stage of development. Detection limits for actinide elements are expected to be on the order of 1 ´ 10 6 atoms (~0.5 fg) or lower with an initial measurement capacity of a few hundred samples per year. The ultimate detection sensitivity is expected to be ~1 ´ 10 5 atoms. Here we provide a review of non-conventional measurement techniquesÑincluding AMSÑfor the determination of low-levels of 239 Pu and other actinide elements in environmental samples. We include a discussion of potential measurement interferences and sample preparation requirements for the different techniques, and outline our proposed AMS system design and strategic approach for the development of low-level actinide detection capability at CAMS.

  14. Kinetics of carboplatin-DNA binding in genomic DNA and bladder cancer cells as determined by accelerator mass spectrometry

    SciTech Connect

    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.

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

    PubMed

    Qiao, Jixin; Hou, Xiaolin; Roos, Per; Lachner, Johannes; Christl, Marcus; Xu, Yihong

    2013-09-17

    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. Several experimental parameters affecting the analytical performance were investigated and compared including sample preboiling operation, aging time, amount of coprecipitating reagent, reagent for pH adjustment, sedimentation time, and organic matter decomposition approach. The overall analytical results 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 time, an immediate coprecipitation without preboiling and aging could also provide fairly satisfactory chemical yields for both Np and Pu (50-60%) with high sample throughput (4 h/sample). Within the developed method, (242)Pu was exploited as chemical yield tracer for both Pu and Np isotopes. (242)Pu was also used as a spike in the AMS measurement for quantification of (239)Pu and (237)Np concentrations. The results show that, under the optimal experimental condition, the chemical yields of (237)Np and (242)Pu are nearly identical, indicating the high feasibility of (242)Pu as a nonisotopic tracer for (237)Np determination in real urine samples. The analytical method was validated by analysis of a number of urine samples spiked with different levels of (237)Np and (239)Pu. The measured values of (237)Np and (239)Pu by AMS exhibit good agreement (R(2) ≥ 0.955) with the spiked ones confirming the reliability of the proposed method.

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

    NASA Astrophysics Data System (ADS)

    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.

  17. Human Vitamin B12 Absorption and Metabolism are Measured by Accelerator Mass Spectrometry Using Specifically Labeled 14C-Cobalamin

    SciTech Connect

    Carkeet, C; Dueker, S R; Lango, J; Buchholz, B A; Miller, J W; Green, R; Hammock, B D; Roth, J R; Anderson, P J

    2006-01-26

    There is need for an improved test of human ability to assimilate dietary vitamin B{sub 12}. Assaying and understanding absorption and uptake of B{sub 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 {sup 14}C-labeled substances after oral ingestion because it is more sensitive than decay counting and can measure levels of carbon-14 ({sup 14}C) in microliter volumes of biological samples, with negligible exposure of subjects to radioactivity. The test we describe employs amounts of B{sub 12} in the range of normal dietary intake. The B{sub 12} used was quantitatively labeled with {sup 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{sub 12} or two of its precursors: cobinamide and dimethylbenzimidazole (DMB). When provided with {sup 14}C-DMB specifically labeled in the C2 position, cells produced {sup 14}C-B{sub 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 {sup 14}C-B{sub 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{sub 12} assimilation.

  18. Tropospheric Emission Spectrometer and Airborne Emission Spectrometer

    NASA Technical Reports Server (NTRS)

    Glavich, T.; Beer, R.

    1996-01-01

    The Tropospheric Emission Spectrometer (TES) is an instrument being developed for the NASA Earth Observing System Chemistry Platform. TES will measure the distribution of ozone and its precursors in the lower atmosphere. The Airborne Emission Spectrometer (AES) is an aircraft precursor to TES. Applicable descriptions are given of instrument design, technology challenges, implementation and operations for both.

  19. Evaluation of Brāhmī ghṛtam in children suffering from Attention Deficit Hyperactivity Disorder

    PubMed Central

    Bhalerao, Supriya; Munshi, Renuka; Nesari, Tanuja; Shah, Heenal

    2013-01-01

    Introduction: Attention Deficit Hyperactivity Disorder (ADHD) is characterized by a persistent pattern of inattention and/or hyperactivity-impulsivity. In view of the adverse effects associated with psycho-stimulants used for the treatment of this disorder, efficacy of Brāhmī ghṛtam was evaluated in this condition. Materials and Methods: After following due ethical considerations, children of either sex between the age group of 6 and 12 years diagnosed to be suffering from mixed variety of ADHD as per The Diagnostic and Statistical Manual of Mental Disorders (DSM) IV criteria irrespective of other co-morbid psychiatric illnesses were recruited in the study. Initially a pilot study (n = 10) was carried out to confirm the efficacy of the identified dose of Brāhmī ghṛtam. Using this dose, further therapeutic confirmatory study (n = 27) was carried out, wherein Brāhmī ghṛtam was compared with methylphenidate. Effect on ADHD symptoms was assessed using the Dupaul ADHD rating scale and this was the main efficacy parameter. Results: In the pilot exploratory study, Brāhmī ghṛtam showed 66% decrease in total ADHD score. In the therapeutic confirmatory study, only 16% improvement was seen with Brāhmī ghṛtam, which was similar to methylphenidate, standard treatment for ADHD that was used as a comparator in the present study. No side-effects were reported in both studies. Conclusion: Our study thus has adequately demonstrated efficacy and safety of Brāhmī ghṛtam in ADHD. PMID:25284947

  20. Compact Infrared Spectrometers

    NASA Technical Reports Server (NTRS)

    Mouroulis, Pantazis

    2009-01-01

    Concentric spectrometer forms are advantageous for constructing a variety of systems spanning the entire visible to infrared range. Spectrometer examples are given, including broadband or high resolution forms. Some issues associated with the Dyson catadioptric type are also discussed.

  1. Mars Airborne Prospecting Spectrometer

    NASA Astrophysics Data System (ADS)

    Steinkraus, J. M.; Wright, M. W.; Rheingans, B. E.; Steinkraus, D. E.; George, W. P.; Aljabri, A.; Hall, J. L.; Scott, D. C.

    2012-06-01

    One novel approach towards addressing the need for innovative instrumentation and investigation approaches is the integration of a suite of four spectrometer systems to form the Mars Airborne Prospecting Spectrometers (MAPS) for prospecting on Mars.

  2. Determination of Atto- to Femtogram Levels of Americium and Curium Isotopes in Large-Volume Urine Samples by Compact Accelerator Mass Spectrometry.

    PubMed

    Dai, Xiongxin; Christl, Marcus; Kramer-Tremblay, Sheila; Synal, Hans-Arno

    2016-03-01

    Ultralow level analysis of actinides in urine samples may be required for dose assessment in the event of internal exposures to these radionuclides at nuclear facilities and nuclear power plants. A new bioassay method for analysis of sub-femtogram levels of Am and Cm in large-volume urine samples was developed. Americium and curium were co-precipitated with hydrous titanium oxide from the urine matrix and purified by column chromatography separation. After target preparation using mixed titanium/iron oxides, the final sample was measured by compact accelerator mass spectrometry. Urine samples spiked with known quantities of Am and Cm isotopes in the range of attogram to femtogram levels were measured for method evaluation. The results are in good agreement with the expected values, demonstrating the feasibility of compact accelerator mass spectrometry (AMS) for the determination of minor actinides at the levels of attogram/liter in urine samples to meet stringent sensitivity requirements for internal dosimetry assessment. PMID:26822907

  3. Human in Vivo Pharmacokinetics of [(14)C]Dibenzo[def,p]chrysene by Accelerator Mass Spectrometry Following Oral Microdosing.

    PubMed

    Madeen, Erin; Corley, Richard A; Crowell, Susan; Turteltaub, Kenneth; Ognibene, Ted; Malfatti, Mike; McQuistan, Tammie J; Garrard, Mary; Sudakin, Dan; Williams, David E

    2015-01-20

    Dibenzo(def,p)chrysene (DBC), (also known as dibenzo[a,l]pyrene), is a high molecular weight polycyclic aromatic hydrocarbon (PAH) found in the environment, including food, produced by the incomplete combustion of hydrocarbons. DBC, classified by IARC as a 2A probable human carcinogen, has a relative potency factor (RPF) in animal cancer models 30-fold higher than benzo[a]pyrene. No data are available describing the disposition of high molecular weight (>4 rings) PAHs in humans to compare to animal studies. Pharmacokinetics of DBC was determined in 3 female and 6 male human volunteers following oral microdosing (29 ng, 5 nCi) of [(14)C]-DBC. This study was made possible with highly sensitive accelerator mass spectrometry (AMS), capable of detecting [(14)C]-DBC equivalents in plasma and urine following a dose considered of de minimus risk to human health. Plasma and urine were collected over 72 h. The plasma Cmax was 68.8 ± 44.3 fg·mL(-1) with a Tmax of 2.25 ± 1.04 h. Elimination occurred in two distinct phases: a rapid (α)-phase, with a T1/2 of 5.8 ± 3.4 h and an apparent elimination rate constant (Kel) of 0.17 ± 0.12 fg·h(-1), followed by a slower (β)-phase, with a T1/2 of 41.3 ± 29.8 h and an apparent Kel of 0.03 ± 0.02 fg·h(-1). In spite of the high degree of hydrophobicity (log Kow of 7.4), DBC was eliminated rapidly in humans, as are most PAHs in animals, compared to other hydrophobic persistent organic pollutants such as, DDT, PCBs and TCDD. Preliminary examination utilizing a new UHPLC-AMS interface, suggests the presence of polar metabolites in plasma as early as 45 min following dosing. This is the first in vivo data set describing pharmacokinetics in humans of a high molecular weight PAH and should be a valuable addition to risk assessment paradigms.

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

    PubMed Central

    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

  5. Precision and accuracy in the quantitative analysis of biological samples by accelerator mass spectrometry: application in microdose absolute bioavailability studies.

    PubMed

    Gao, Lan; Li, Jing; Kasserra, Claudia; Song, Qi; Arjomand, Ali; Hesk, David; Chowdhury, Swapan K

    2011-07-15

    Determination of the pharmacokinetics and absolute bioavailability of an experimental compound, SCH 900518, following a 89.7 nCi (100 μg) intravenous (iv) dose of (14)C-SCH 900518 2 h post 200 mg oral administration of nonradiolabeled SCH 900518 to six healthy male subjects has been described. The plasma concentration of SCH 900518 was measured using a validated LC-MS/MS system, and accelerator mass spectrometry (AMS) was used for quantitative plasma (14)C-SCH 900518 concentration determination. Calibration standards and quality controls were included for every batch of sample analysis by AMS to ensure acceptable quality of the assay. Plasma (14)C-SCH 900518 concentrations were derived from the regression function established from the calibration standards, rather than directly from isotopic ratios from AMS measurement. The precision and accuracy of quality controls and calibration standards met the requirements of bioanalytical guidance (U.S. Department of Health and Human Services, Food and Drug Administration, Center for Drug Evaluation and Research, Center for Veterinary Medicine. Guidance for Industry: Bioanalytical Method Validation (ucm070107), May 2001. http://www.fda.gov/downloads/Drugs/GuidanceCompilanceRegulatoryInformation/Guidances/ucm070107.pdf ). The AMS measurement had a linear response range from 0.0159 to 9.07 dpm/mL for plasma (14)C-SCH 900158 concentrations. The CV and accuracy were 3.4-8.5% and 94-108% (82-119% for the lower limit of quantitation (LLOQ)), respectively, with a correlation coefficient of 0.9998. The absolute bioavailability was calculated from the dose-normalized area under the curve of iv and oral doses after the plasma concentrations were plotted vs the sampling time post oral dose. The mean absolute bioavailability of SCH 900518 was 40.8% (range 16.8-60.6%). The typical accuracy and standard deviation in AMS quantitative analysis of drugs from human plasma samples have been reported for the first time, and the impact of these

  6. The French accelerator mass spectrometry facility ASTER after 4 years: Status and recent developments on 36Cl and 129I

    NASA Astrophysics Data System (ADS)

    Arnold, Maurice; Aumaître, Georges; Bourlès, Didier L.; Keddadouche, Karim; Braucher, Régis; Finkel, Robert C.; Nottoli, Emmanuelle; Benedetti, Lucilla; Merchel, Silke

    2013-01-01

    Since the acceptance tests of the French 5 MV accelerator mass spectrometry facility ASTER in 2007, routine measurement conditions for the long-lived radionuclides 10Be and 26Al have been established. Yearly sample throughput as high as over 3300 unknowns has been reached for 10Be in 2010. Cross-contamination for volatile elements has been largely solved by an ion source upgrade allowing 36Cl measurements at ASTER. However, recent long-term tests using 35Cl/37Cl samples with strongly varying ratios have shown that identical targets lead to different 35Cl/37Cl 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 26Al and 41Ca standards and taking part in round-robin exercises of 10Be and 36Cl, a two-step cross-calibration of secondary in-house 129I standards has been performed. The NIST 3231 standard containing 129I/127I at (0.981 ± 0.012) × 10-6 has been used for step-wise dilution with NaI to produce gram-quantities of lower-level standards for every-day use. The resulting material SM-I-9 (129I/127I: ∼1 × 10-9) has been measured vs. AgI produced using minimum chemistry from the two NIST ampoules containing a solution with a nominal ratio 129I/127I of (0.982 ± 0.012) × 10-8. In a second stage, SM-I-10 and SM-I-11 with ratios of ∼1 × 10-10 and ∼1 × 10-11, respectively, have been cross-calibrated against SM-I-9. Individual uncertainties of the traceable secondary standards are 1.3-1.4% (2σ), mainly originating from the given uncertainty of the primary NIST 3231 at the 10-8 level. The cross-contamination for iodine is in the range of 0.4-0.6% within the first 20 h of running

  7. Morphine brain pharmacokinetics at very low concentrations studied with accelerator mass spectrometry and liquid chromatography-tandem mass spectrometry.

    PubMed

    Sadiq, Muhammad Waqas; Salehpour, Mehran; Forsgard, Niklas; Possnert, Göran; Hammarlund-Udenaes, Margareta

    2011-02-01

    Morphine has been predicted to show nonlinear blood-brain barrier transport at lower concentrations. In this study, we investigated the possibility of separating active influx of morphine from its efflux by using very low morphine concentrations and compared accelerator mass spectrometry (AMS) with liquid chromatography-tandem mass spectrometry (LC-MS/MS) as a method for analyzing microdialysis samples. A 10-min bolus infusion of morphine, followed by a constant-rate infusion, was given to male rats (n = 6) to achieve high (250 ng/ml), medium (50 ng/ml), and low (10 ng/ml) steady-state plasma concentrations. An additional rat received infusions to achieve low (10 ng/ml), very low (2 ng/ml), and ultralow (0.4 ng/ml) concentrations. Unbound morphine concentrations from brain extracellular fluid and blood were sampled by microdialysis and analyzed by LC-MS/MS and AMS. The average partition coefficient for unbound drug (K(p,uu)) values for the low and medium steady-state levels were 0.22 ± 0.08 and 0.21 ± 0.05, respectively, when measured by AMS [not significant (NS); p = 0.5]. For the medium and high steady-state levels, K(p,uu) values were 0.24 ± 0.05 and 0.26 ± 0.05, respectively, when measured by LC-MS/MS (NS; p = 0.2). For the low, very low, and ultralow steady-state levels, K(p,uu) values were 0.16 ± 0.01, 0.16 ± 0.02, and 0.18 ± 0.03, respectively, when measured by AMS. The medium-concentration K(p,uu) values were, on average, 16% lower when measured by AMS than by LC-MS/MS. There were no significant changes in K(p,uu) over a 625-fold concentration range (0.4-250 ng/ml). It was not possible to separate active uptake transport from active efflux using these low concentrations. The two analytical methods provided indistinguishable results for plasma concentrations but differed by up to 38% for microdialysis samples; however, this difference did not affect our conclusions.

  8. Systemic autoimmunity in TAM triple knockout mice causes inflammatory brain damage and cell death.

    PubMed

    Li, Qiutang; Lu, Qingjun; Lu, Huayi; Tian, Shifu; Lu, Qingxian

    2013-01-01

    The Tyro3, Axl and Mertk (TAM) triply knockout (TKO) mice exhibit systemic autoimmune diseases, with characteristics of increased proinflammatory cytokine production, autoantibody deposition and autoreactive lymphocyte infiltration into a variety of tissues. Here we show that TKO mice produce high level of serum TNF-α and specific autoantibodies deposited onto brain blood vessels. The brain-blood barrier (BBB) in mutant brains exhibited increased permeability for Evans blue and fluorescent-dextran, suggesting a breakdown of the BBB in the mutant brains. Impaired BBB integrity facilitated autoreactive T cells infiltrating into all regions of the mutant brains. Brain autoimmune disorder caused accumulation of the ubiquitin-reactive aggregates in the mutant hippocampus, and early formation of autofluorescent lipofuscins in the neurons throughout the entire brains. Chronic neuroinflammation caused damage of the hippocampal mossy fibers and neuronal apoptotic death. This study shows that chronic systemic inflammation and autoimmune disorders in the TKO mice cause neuronal damage and death.

  9. Bladder cancer cells re-educate TAMs through lactate shuttling in the microfluidic cancer microenvironment

    PubMed Central

    Liu, Pengfei; Cao, Yanwei; Wang, Yonghua; Yang, Xuecheng; Xu, Xiaodong; Wang, Xinsheng; Niu, Haitao

    2015-01-01

    Background In the present study, we aimed to investigate the influence of lactate shuttling on the functional polarization and spatial distribution of transitional cell carcinoma of the bladder (TCCB) cells and macrophages. Methods We designed a microfluidic coculture chip for real-time integrative assays. The effect of lactate shuttling on the re-education of macrophages by TCCB cells was explored by measuring the levels of NO using a total NO assay kit and by evaluating the protein expression of iNOS, p-NFkB-p65, Arg-1 and HIF-1α via cell immunofluorescence and western blotting. Additionally, we examined TCCB cell viability using acridine orange/ethidium bromide (AO/EB) and MitoTracker staining. Moreover, the concentration distributions of lactate and large signaling proteins in the culture chambers were measured using 4′,6-diamidino-2-phenylindole (DAPI) and fluorescein isothiocyanate-dextran (FITC-dextran). Furthermore, the recruitment of macrophages and the influence of macrophages on BC metastasis were observed via light microscopy. Results We confirmed that TCCB cells reprogrammed macrophages into an M2 phenotype. Moreover, lactate inhibited M1 polarization and induced M2 polarization of macrophages, but blockade of cancer cell-macrophage lactate flux significantly inhibited the re-education of macrophages by TCCB cells. In addition, lactate diffused faster and deeper than large signaling proteins in the microfluidic tumor microenvironment. Furthermore, lactate alone induced the migration of macrophages, and M1, but not M2, macrophages reduced the motility of TCCB cells. Conclusions TCCB cells reprogrammed macrophages into an M2 phenotype in a manner that depended on cancer cell-TAM lactate flux. Furthermore, the lactate shuttle may be a determinant of the density of TAMs in tumor tissue. PMID:26474279

  10. Validating the Satisfaction and Continuance Intention of E-Learning Systems: Combining TAM and IS Success Models

    ERIC Educational Resources Information Center

    Lin, Tung-Cheng; Chen, Ching-Jen

    2012-01-01

    Many e-learning studies have evaluated learning attitudes and behaviors, based on TAM. However, a successful e-learning system (ELS) should take both system and information quality into account by applying ISM developed by Delone and McLean. In addition, the acceptance for information system depends on the perceived usefulness and ease of use…

  11. LLNL/UC (Lawrence Livermore National Laboratory)/(University of California) AMS (accelerator mass spectrometry) facility and research program

    SciTech Connect

    Davis, J.C.; Proctor, I.D.; Southon, J.R.; Caffee, M.W.; Heikkinen, D.W.; Roberts, M.L.; Moore, T.L.; Turteltaub, K.W.; Nelson, D.E.; Loyd, D.H.; Vogel, J.S.

    1990-04-18

    The Lawrence Livermore National Laboratory (LLNL) and the University of California (UC) now have in operation a large AMS spectrometer built as part of a new multiuser laboratory centered on an FN tandem. AMS measurements are expected to use half of the beam time of the accelerator. LLNL use of AMS is in research on consequences of energy usage. Examples include global warming, geophysical site characterization, radiation biology and dosimetry, and study of mutagenic and carcinogenic processes. UC research activities are in clinical applications, archaeology and anthropology, oceanography, and geophysical and geochemical research. Access is also possible for researchers outside the UC system. The technological focus of the laboratory is on achieving high rates of sample through-put, unattended operation, and advances in sample preparation methods. Because of the expected growth in the research programs and the other obligations of the present accelerator, we are designing a follow-on dedicated facility for only AMS and microprobe analysis that will contain at least two accelerators with multiple spectrometers. 10 refs., 1 fig.

  12. Spherical grating spectrometers

    NASA Astrophysics Data System (ADS)

    O'Donoghue, Darragh; Clemens, J. Christopher

    2014-07-01

    We describe designs for spectrometers employing convex dispersers. The Offner spectrometer was the first such instrument; it has almost exclusively been employed on satellite platforms, and has had little impact on ground-based instruments. We have learned how to fabricate curved Volume Phase Holographic (VPH) gratings and, in contrast to the planar gratings of traditional spectrometers, describe how such devices can be used in optical/infrared spectrometers designed specifically for curved diffraction gratings. Volume Phase Holographic gratings are highly efficient compared to conventional surface relief gratings; they have become the disperser of choice in optical / NIR spectrometers. The advantage of spectrometers with curved VPH dispersers is the very small number of optical elements used (the simplest comprising a grating and a spherical mirror), as well as illumination of mirrors off axis, resulting in greater efficiency and reduction in size. We describe a "Half Offner" spectrometer, an even simpler version of the Offner spectrometer. We present an entirely novel design, the Spherical Transmission Grating Spectrometer (STGS), and discuss exemplary applications, including a design for a double-beam spectrometer without any requirement for a dichroic. This paradigm change in spectrometer design offers an alternative to all-refractive astronomical spectrometer designs, using expensive, fragile lens elements fabricated from CaF2 or even more exotic materials. The unobscured mirror layout avoids a major drawback of the previous generation of catadioptric spectrometer designs. We describe laboratory measurements of the efficiency and image quality of a curved VPH grating in a STGS design, demonstrating, simultaneously, efficiency comparable to planar VPH gratings along with good image quality. The stage is now set for construction of a prototype instrument with impressive performance.

  13. Possible incorporation of petroleum-based carbons in biochemicals produced by bioprocess--biomass carbon ratio measured by accelerator mass spectrometry.

    PubMed

    Kunioka, Masao

    2010-06-01

    The biomass carbon ratios of biochemicals related to biomass have been reviewed. Commercial products from biomass were explained. The biomass carbon ratios of biochemical compounds were measured by accelerator mass spectrometry (AMS) based on the (14)C concentration of carbons in the compounds. This measuring method uses the mechanism that biomass carbons include a very low level of (14)C and petroleum carbons do not include (14)C similar to the carbon dating measuring method. It was confirmed that there were some biochemicals synthesized from petroleum-based carbons. This AMS method has a high accuracy with a small standard deviation and can be applied to plastic products.

  14. TAM receptor-dependent regulation of SOCS3 and MAPKs contributes to pro-inflammatory cytokine downregulation following chronic NOD2 stimulation of human macrophages1

    PubMed Central

    Zheng, Shasha; Hedl, Matija; Abraham, Clara

    2014-01-01

    Microbial-induced cytokine regulation is critical to intestinal immune homeostasis. Acute stimulation of NOD2, the Crohn’s disease-associated sensor of bacterial peptidoglycan, induces cytokines. However, cytokines are attenuated after chronic NOD2 and pattern recognition receptor (PRR) stimulation of macrophages; similar attenuation is observed in intestinal macrophages. The role of Tyro3, Axl and Mer (TAM) receptors in regulating chronic PRR stimulation and NOD2-induced outcomes has not been examined. Moreover, TAM receptors have been relatively less investigated in human macrophages. Whereas TAM receptors did not downregulate acute NOD2-induced cytokines in primary human macrophages, they were essential for downregulating signaling and pro-inflammatory cytokine secretion after chronic NOD2 and TLR4 stimulation. Axl and Mer were similarly required in mice for cytokine downregulation after chronic NOD2 stimulation in vivo and in intestinal tissues. Consistently, TAM expression was increased in human intestinal myeloid-derived cells. Chronic NOD2 stimulation led to IL-10- and TGFβ-dependent TAM upregulation in human macrophages, which in turn, upregulated SOCS3 expression. Restoring SOCS3 expression under TAM knockdown conditions restored chronic NOD2-mediated pro-inflammatory cytokine downregulation. In contrast to the upregulated pro-inflammatory cytokines, attenuated IL-10 secretion was maintained in TAM-deficient macrophages upon chronic NOD2 stimulation. The level of MAPK activation in TAM-deficient macrophages after chronic NOD2 stimulation was insufficient to upregulate IL-10 secretion; however, full restoration of MAPK activation under these conditions restored c-Fos, c-Jun, MAFK and PU.1 binding to the IL-10 promoter and IL-10 secretion. Therefore, TAM receptors are critical for downregulating pro-inflammatory cytokines under the chronic NOD2 stimulation conditions observed in the intestinal environment. PMID:25567680

  15. The Quadrupole Mass Spectrometer

    ERIC Educational Resources Information Center

    Matheson, E.; Harris, T. J.

    1969-01-01

    Describes the construction and operation of a quadrupole mass spectrometer for experiments in an advanced-teaching laboratory. Discusses the theory of operation of the spectrometer and the factors affecting the resolution. Some examples of mass spectra obtained with this instrument are presented and discussed. (LC)

  16. Early Modern Humans and Morphological Variation in Southeast Asia: Fossil Evidence from Tam Pa Ling, Laos

    PubMed Central

    Demeter, Fabrice; Shackelford, Laura; Westaway, Kira; Duringer, Philippe; Bacon, Anne-Marie; Ponche, Jean-Luc; Wu, Xiujie; Sayavongkhamdy, Thongsa; Zhao, Jian-Xin; Barnes, Lani; Boyon, Marc; Sichanthongtip, Phonephanh; Sénégas, Frank; Karpoff, Anne-Marie; Patole-Edoumba, Elise; Coppens, Yves; Braga, José

    2015-01-01

    Little is known about the timing of modern human emergence and occupation in Eastern Eurasia. However a rapid migration out of Africa into Southeast Asia by at least 60 ka is supported by archaeological, paleogenetic and paleoanthropological data. Recent discoveries in Laos, a modern human cranium (TPL1) from Tam Pa Ling‘s cave, provided the first evidence for the presence of early modern humans in mainland Southeast Asia by 63-46 ka. In the current study, a complete human mandible representing a second individual, TPL 2, is described using discrete traits and geometric morphometrics with an emphasis on determining its population affinity. The TPL2 mandible has a chin and other discrete traits consistent with early modern humans, but it retains a robust lateral corpus and internal corporal morphology typical of archaic humans across the Old World. The mosaic morphology of TPL2 and the fully modern human morphology of TPL1 suggest that a large range of morphological variation was present in early modern human populations residing in the eastern Eurasia by MIS 3. PMID:25849125

  17. Purification and Bicelle Crystallization for Structure Determination of the E. coli Outer Membrane Protein TamA.

    PubMed

    Gruss, Fabian; Hiller, Sebastian; Maier, Timm

    2015-01-01

    TamA is an Omp85 protein involved in autotransporter assembly in the outer membrane of Escherichia coli. It comprises a C-terminal 16-stranded transmembrane β-barrel as well as three periplasmic POTRA domains, and is a challenging target for structure determination. Here, we present a method for crystal structure determination of TamA, including recombinant expression in E. coli, detergent extraction, chromatographic purification, and bicelle crystallization in combination with seeding. As a result, crystals in space group P21212 are obtained, which diffract to 2.3 Å resolution. This protocol also serves as a template for structure determination of other outer membrane proteins, in particular of the Omp85 family.

  18. Structural elucidation of the DFG-Asp in and DFG-Asp out states of TAM kinases and insight into the selectivity of their inhibitors.

    PubMed

    Messoussi, Abdellah; Peyronnet, Lucile; Feneyrolles, Clémence; Chevé, Gwénaël; Bougrin, Khalid; Yasri, Aziz

    2014-10-10

    Structural elucidation of the active (DFG-Asp in) and inactive (DFG-Asp out) states of the TAM family of receptor tyrosine kinases is required for future development of TAM inhibitors as drugs. Herein we report a computational study on each of the three TAM members Tyro-3, Axl and Mer. DFG-Asp in and DFG-Asp out homology models of each one were built based on the X-ray structure of c-Met kinase, an enzyme with a closely related sequence. Structural validation and in silico screening enabled identification of critical amino acids for ligand binding within the active site of each DFG-Asp in and DFG-Asp out model. The position and nature of amino acids that differ among Tyro-3, Axl and Mer, and the potential role of these residues in the design of selective TAM ligands, are discussed.

  19. The SAGE spectrometer

    NASA Astrophysics Data System (ADS)

    Pakarinen, J.; Papadakis, P.; Sorri, J.; Herzberg, R.-D.; Greenlees, P. T.; Butler, P. A.; Coleman-Smith, P. J.; Cox, D. M.; Cresswell, J. R.; Jones, P.; Julin, R.; Konki, J.; Lazarus, I. H.; Letts, S. C.; Mistry, A.; Page, R. D.; Parr, E.; Pucknell, V. F. E.; Rahkila, P.; Sampson, J.; Sandzelius, M.; Seddon, D. A.; Simpson, J.; Thornhill, J.; Wells, D.

    2014-03-01

    The SAGE spectrometer has been constructed for in-beam nuclear structure studies. SAGE combines a Ge-detector array and an electron spectrometer for detection of -rays and internal conversion electrons, respectively, and allows simultaneous observation of both electrons and -rays emitted from excited nuclei. SAGE is set up in the Accelerator Laboratory of the University of Jyväskylä and works in conjunction with the RITU gas-filled recoil separator and the GREAT focal-plane spectrometer allowing the use of the recoil-decay tagging method.

  20. TAM 112’ Wheat, resistant to greenbug and wheat curl mite and adapted to the dryland production system in the Southern High Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    TAM 112’ (PI 643143), a hard red winter wheat (Triticum aestivum L.) is an F4 derived line from the cross U1254-7-9-2-1/TXGH10440. U1254-7-9-2 is a USDA-ARS germplasm line from the Plant Science and Entomology Research unit, Manhattan, Kansas. It was developed from the cross TAM 200/TA2460. TA24...

  1. Nanoparticle formulation enhanced protective immunity provoked by PYGPI8p-transamidase related protein (PyTAM) DNA vaccine in Plasmodium yoelii malaria model.

    PubMed

    Cherif, Mahamoud Sama; Shuaibu, Mohammed Nasir; Kodama, Yukinobu; Kurosaki, Tomoaki; Helegbe, Gideon Kofi; Kikuchi, Mihoko; Ichinose, Akitoyo; Yanagi, Tetsuo; Sasaki, Hitoshi; Yui, Katsuyuki; Tien, Nguyen Huy; Karbwang, Juntra; Hirayama, Kenji

    2014-04-01

    We have previously reported the new formulation of polyethylimine (PEI) with gamma polyglutamic acid (γ-PGA) nanoparticle (NP) to have provided Plasmodium yoelii merozoite surface protein-1 (PyMSP-1) plasmid DNA vaccine with enhanced protective cellular and humoral immunity in the lethal mouse malaria model. PyGPI8p-transamidase-related protein (PyTAM) was selected as a possible candidate vaccine antigen by using DNA vaccination screening from 29 GPI anchor and signal sequence motif positive genes picked up using web-based bioinformatics tools; though the observed protection was not complete. Here, we observed augmented protective effect of PyTAM DNA vaccine by using PEI and γ-PGA complex as delivery system. NP-coated PyTAM plasmid DNA immunized mice showed a significant survival rate from lethal P. yoelii challenge infection compared with naked PyTAM plasmid or with NP-coated empty plasmid DNA group. Antigen-specific IgG1 and IgG2b subclass antibody levels, proportion of CD4 and CD8T cells producing IFN-γ in the splenocytes and IL-4, IFN-γ, IL-12 and TNF-α levels in the sera and in the supernatants from ex vivo splenocytes culture were all enhanced by the NP-coated PyTAM DNA vaccine. These data indicates that NP augments PyTAM protective immune response, and this enhancement was associated with increased DC activation and concomitant IL-12 production.

  2. Measurement of {sup 63}Ni and {sup 59}Ni by accelerator mass spectrometry using characteristic projectile x-rays

    SciTech Connect

    McAninch, J.E.; Hainsworth, L.J.; Marchetti, A.A.

    1996-05-01

    The long-lived isotopes of nickel ({sup 59}Ni, {sup 63}Ni) have current and potential use in a number of applications including cosmic radiation studies, biomedical tracing, characterization of low-level radioactive wastes, and neutron dosimetry. Methods are being developed at LLNL for the routine detection of these isotopes by AMS. One intended application is in Hiroshima dosimetry. The reaction {sup 63}Cu(n,p){sup 63}Ni has been identified as one of a small number of reactions which might be used for the direct determination of the fast neutron fluence emitted by the Hiroshima bomb. AMS measurement of {sup 63}Ni(t{sub 1/2} = 100 y) requires the chemical removal of {sup 63}Cu, which is a stable isobar of {sup 63}Ni. Following the electrochemical separation of Ni from gram-sized copper samples, the Cu concentration is further lowered to < 2 x 10{sup -8} (Cu/Ni) using the reaction of Ni with carbon monoxide to form the gas Ni(CO){sub 4}. The Ni(CO){sub 4} is thermally decomposed directly in sample holders for measurement by AMS. After analysis in the AMS spectrometer, the ions are identified using characteristic projectile x-rays, allowing further rejection of remaining {sup 63}Cu. In a demonstration experiment, {sup 63}Ni was measured in Cu wires (2-20 g) which had been exposed to neutrons from a {sup 252}Cf source. We successfully measured {sup 63}Ni at levels necessary for the measurement of Cu samples exposed near the Hiroshima hypocenter. For the demonstration samples, the Cu content was chemically reduced by a factor of 10{sup 12} with quantitative retention of {sup 63}Ni. Detection sensitivity (3{sigma}) was {approximately}20 fg {sup 63}Ni in 1 mg Ni carrier ({sup 63}Ni/Ni {approx} 2 x 10{sup -11}). Significant improvements in sensitivity are expected with planned incremental changes in the methods. Preliminary results indicate that a similar sensitivity is achievable for {sup 59}Ni (t{sub 1/2} = 10{sup 5} y).

  3. Imaging Fourier transform spectrometer

    SciTech Connect

    Bennett, C.L.

    1993-09-13

    This invention is comprised of an imaging Fourier transform spectrometer having a Fourier transform infrared spectrometer providing a series of images to a focal plane array camera. The focal plane array camera is clocked to a multiple of zero crossing occurrences as caused by a moving mirror of the Fourier transform infrared spectrometer and as detected by a laser detector such that the frame capture rate of the focal plane array camera corresponds to a multiple of the zero crossing rate of the Fourier transform infrared spectrometer. The images are transmitted to a computer for processing such that representations of the images as viewed in the light of an arbitrary spectral ``fingerprint`` pattern can be displayed on a monitor or otherwise stored and manipulated by the computer.

  4. Composite Spectrometer Prisms

    NASA Technical Reports Server (NTRS)

    Breckinridge, J. B.; Page, N. A.; Rodgers, J. M.

    1985-01-01

    Efficient linear dispersive element for spectrometer instruments achieved using several different glasses in multiple-element prism. Good results obtained in both two-and three-element prisms using variety of different glass materials.

  5. AUTOMATIC MASS SPECTROMETER

    DOEpatents

    Hanson, M.L.; Tabor, C.D. Jr.

    1961-12-01

    A mass spectrometer for analyzing the components of a gas is designed which is capable of continuous automatic operation such as analysis of samples of process gas from a continuous production system where the gas content may be changing. (AEC)

  6. A Simple Raman Spectrometer.

    ERIC Educational Resources Information Center

    Blond, J. P.; Boggett, D. M.

    1980-01-01

    Discusses some basic physical ideas about light scattering and describes a simple Raman spectrometer, a single prism monochromator and a multiplier detector. This discussion is intended for British undergraduate physics students. (HM)

  7. Fourier Transform Spectrometer System

    NASA Technical Reports Server (NTRS)

    Campbell, Joel F. (Inventor)

    2014-01-01

    A Fourier transform spectrometer (FTS) data acquisition system includes an FTS spectrometer that receives a spectral signal and a laser signal. The system further includes a wideband detector, which is in communication with the FTS spectrometer and receives the spectral signal and laser signal from the FTS spectrometer. The wideband detector produces a composite signal comprising the laser signal and the spectral signal. The system further comprises a converter in communication with the wideband detector to receive and digitize the composite signal. The system further includes a signal processing unit that receives the composite signal from the converter. The signal processing unit further filters the laser signal and the spectral signal from the composite signal and demodulates the laser signal, to produce velocity corrected spectral data.

  8. Production and isolation of homologs of flerovium and element 115 at the Lawrence Livermore National Laboratory Center for Accelerator Mass Spectrometry

    SciTech Connect

    Despotopulos, John D.; Kmak, Kelly N.; Gharibyan, Narek; Brown, Thomas A.; Grant, Patrick M.; Henderson, Roger A.; Moody, Kent J.; Tumey, Scott J.; Shaughnessy, Dawn A.; Sudowe, Ralf

    2015-10-01

    Here, new procedures have been developed to isolate no-carrier-added (NCA) radionuclides of the homologs and pseudo-homologs of flerovium (Hg, Sn) and element 115 (Sb), produced by 12–15 MeV proton irradiation of foil stacks with the tandem Van-de-Graaff accelerator at the Lawrence Livermore National Laboratory Center for Accelerator Mass Spectrometry (CAMS) facility. The separation of 113Sn from natIn foil was performed with anion-exchange chromatography from hydrochloric and nitric acid matrices. A cation-exchange chromatography method based on hydrochloric and mixed hydrochloric/hydroiodic acids was used to separate 124Sb from natSn foil. A procedure using Eichrom TEVA resin was developed to separate 197Hg from Au foil. These results demonstrate the suitability of using the CAMS facility to produce NCA radioisotopes for studies of transactinide homologs.

  9. Production and isolation of homologs of flerovium and element 115 at the Lawrence Livermore National Laboratory Center for Accelerator Mass Spectrometry

    DOE PAGES

    Despotopulos, John D.; Kmak, Kelly N.; Gharibyan, Narek; Brown, Thomas A.; Grant, Patrick M.; Henderson, Roger A.; Moody, Kent J.; Tumey, Scott J.; Shaughnessy, Dawn A.; Sudowe, Ralf

    2015-10-01

    Here, new procedures have been developed to isolate no-carrier-added (NCA) radionuclides of the homologs and pseudo-homologs of flerovium (Hg, Sn) and element 115 (Sb), produced by 12–15 MeV proton irradiation of foil stacks with the tandem Van-de-Graaff accelerator at the Lawrence Livermore National Laboratory Center for Accelerator Mass Spectrometry (CAMS) facility. The separation of 113Sn from natIn foil was performed with anion-exchange chromatography from hydrochloric and nitric acid matrices. A cation-exchange chromatography method based on hydrochloric and mixed hydrochloric/hydroiodic acids was used to separate 124Sb from natSn foil. A procedure using Eichrom TEVA resin was developed to separate 197Hg frommore » Au foil. These results demonstrate the suitability of using the CAMS facility to produce NCA radioisotopes for studies of transactinide homologs.« less

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

    PubMed

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

    2014-04-01

    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 HNO3/HClO4, (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. PMID:24525301

  11. MANTRA: An Integral Reactor Physics Experiment to Infer Actinide Capture Cross-sections from Thorium to Californium with Accelerator Mass Spectrometry

    SciTech Connect

    G. Youinou; C. McGrath; G. Imel; M. Paul; R. Pardo; F. Kondev; M. Salvatores; G. Palmiotti

    2011-08-01

    The principle of the proposed experiment is to irradiate very pure actinide samples in the Advanced Test Reactor at INL and, after a given time, determine the amount of the different transmutation products. The determination of the nuclide densities before and after neutron irradiation will allow inference of effective neutron capture cross-sections. This approach has been used in the past and the novelty of this experiment is that the atom densities of the different transmutation products will be determined using the Accelerator Mass Spectrometry technique at the ATLAS facility located at ANL. It is currently planned to irradiate the following isotopes: 232Th, 235U, 236U, 238U, 237Np, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, 241Am, 243Am, 244Cm and 248Cm.

  12. An off Axis Cavity Enhanced Absorption Spectrometer and a Rapid Scan Spectrometer with a Room-Temperature External Cavity Quantum Cascade Laser

    NASA Astrophysics Data System (ADS)

    Liu, Xunchen; Kang, Cheolhwa; Xu, Yunjie

    2009-06-01

    Quantum cascade laser (QCL) is a new type of mid-infrared tunable diode lasers with superior output power and mode quality. Recent developments, such as room temperature operation, wide frequency tunability, and narrow line width, make QCLs an ideal light source for high resolution spectroscopy. Two slit jet infrared spectrometers, namely an off-axis cavity enhanced absorption (CEA) spectrometer and a rapid scan spectrometer with an astigmatic multi-pass cell assembly, have been coupled with a newly purchased room temperature tunable mod-hop-free QCL with a frequency coverage from 1592 cm^{-1} to 1698 cm^{-1} and a scan rate of 0.1 cm^{-1}/ms. Our aim is to utilize these two sensitive spectrometers, that are equipped with a molecular jet expansion, to investigate the chiral molecules-(water)_n clusters. To demonstrate the resolution and sensitivity achieved, the rovibrational transitions of the static N_2O gas and the bending rovibrational transitions of the Ar-water complex, a test system, at 1634 cm^{-1} have been measured. D. Hofstetter and J. Faist in High performance quantum cascade lasers and their applications, Vol.89 Springer-Verlag Berlin & Heidelberg, 2003, pp. 61-98. Y. Xu, X. Liu, Z. Su, R. M. Kulkarni, W. S. Tam, C. Kang, I. Leonov and L. D'Agostino, Proc. Spie, 2009, 722208 (1-11). M. J. Weida and D. J. Nesbitt, J. Chem. Phys. 1997, 106, 3078-3089.

  13. Electron-proton spectrometer

    NASA Technical Reports Server (NTRS)

    Winckler, J. R.

    1973-01-01

    An electron-proton spectrometer was designed to measure the geomagnetically trapped radiation in a geostationary orbit at 6.6 earth radii in the outer radiation belt. This instrument is to be flown on the Applications Technology Satellite-F (ATS-F). The electron-proton spectrometer consists of two permanent magnet surface barrier detector arrays and associated electronics capable of selecting and detecting electrons in three energy ranges: (1) 30-50 keV, (2) 150-200 keV, and (3) 500 keV and protons in three energy ranges. The electron-proton spectrometer has the capability of measuring the fluxes of electrons and protons in various directions with respect to the magnetic field lines running through the satellite. One magnet detector array system is implemented to scan between EME north and south through west, sampling the directional flux in 15 steps. The other magnet-detector array system is fixed looking toward EME east.

  14. Application of TAM III to study sensitivity of soil organic matter degradation to temperature

    NASA Astrophysics Data System (ADS)

    Vikegard, Peter; Barros, Nieves; Piñeiro, Verónica

    2014-05-01

    Traditionally, studies of soil biodegradation are based on CO2 dissipation rates. CO2 is a product of aerobic degradation of labile organic substrates like carbohydrates. That limits the biodegradation concept to just one of the soil organic matter fractions. This feature is responsible for some problems to settle the concept of soil organic matter (SOM) recalcitrance and for controversial results defining sensitivity of SOM to temperature. SOM consists of highly complex macromolecules constituted by fractions with different chemical nature and redox state affecting the chemical nature of biodegradation processes. Biodegradation of fractions more reduced than carbohydrates take place through metabolic pathways that dissipate less CO2 than carbohydrate respiration, that may not dissipate CO2, or that even may uptake CO2. These compounds can be considered more recalcitrant and with lower turnover times than labile SOM just because they are degraded at lower CO2 rates that may be just a consequence of the metabolic path. Nevertheless, decomposition of every kind of organic substrate always releases heat. For this reason, the measurement of the heat rate by calorimetry yields a more realistic measurement of the biodegradation of the SOM continuum. TAM III is one of the most recent calorimeters designed for directly measuring in real time the heat rate associated with any degradation process. It is designed as a multichannel system allowing the concomitant measurement of to up 24 samples at isothermal conditions or through a temperature scanning mode from 18 to 100ºC, allowing the continous measure of any sample at controlled non-isothermal conditions. The temperature scanning mode was tested in several soil samples collected at different depths to study their sensitivity to temperature changes from 18 to 35 ºC calculating the Q10 and the activation energy (EA) by the Arrhenius equation. It was attempted to associate the obtained EA values with the soil thermal

  15. Compact Grism Spectrometer

    NASA Astrophysics Data System (ADS)

    Teare, S. W.

    2003-05-01

    Many observatories and instrument builders are retrofitting visible and near-infrared spectrometers into their existing imaging cameras. Camera designs that reimage the focal plane and have the optical filters located in a pseudo collimated beam are ideal candidates for the addition of a spectrometer. One device commonly used as the dispersing element for such spectrometers is a grism. The traditional grism is constructed from a prism that has had a diffraction grating applied on one surface. The objective of such a design is to use the prism wedge angle to select the desired "in-line" or "zero-deviation" wavelength that passes through on axis. The grating on the surface of the prism provides much of the dispersion for the spectrometer. A grism can also be used in a "constant-dispersion" design which provides an almost linear spatial scale across the spectrum. In this paper we provide an overview of the development of a grism spectrometer for use in a near infrared camera and demonstrate that a compact grism spectrometer can be developed on a very modest budget that can be afforded at almost any facility. The grism design was prototyped using visible light and then a final device was constructed which provides partial coverage in the near infrared I, J, H and K astronomical bands using the appropriate band pass filter for order sorting. The near infrared grism presented here provides a spectral resolution of about 650 and velocity resolution of about 450 km/s. The design of this grism relied on a computer code called Xspect, developed by the author, to determine the various critical parameters of the grism. This work was supported by a small equipment grant from NASA and administered by the AAS.

  16. The Apollo Alpha Spectrometer.

    NASA Technical Reports Server (NTRS)

    Jagoda, N.; Kubierschky, K.; Frank, R.; Carroll, J.

    1973-01-01

    Located in the Science Instrument Module of Apollo 15 and 16, the Alpha Particle Spectrometer was designed to detect and measure the energy of alpha particles emitted by the radon isotopes and their daughter products. The spectrometer sensor consisted of an array of totally depleted silicon surface barrier detectors. Biased amplifier and linear gate techniques were utilized to reduce resolution degradation, thereby permitting the use of a single 512 channel PHA. Sensor identification and in-flight radioactive calibration were incorporated to enhance data reduction.

  17. Comparison of imaging spectrometers

    SciTech Connect

    Bennett, C

    2000-01-09

    Realistic signal to noise performance estimates for the various types of instruments being considered for NGST are compared, based on the point source detection values quoted in the available ISIM final reports. The corresponding sensitivity of the various types of spectrometers operating in a full field imaging mode, for both emission line objects and broad spectral distribution objects, is computed and displayed. For the purpose of seeing the earliest galaxies, or the faintest possible emission line sources, the imaging Fourier transform spectrometer emerges superior to all others, by orders of magnitude in speed.

  18. Broad band waveguide spectrometer

    DOEpatents

    Goldman, Don S.

    1995-01-01

    A spectrometer for analyzing a sample of material utilizing a broad band source of electromagnetic radiation and a detector. The spectrometer employs a waveguide possessing an entry and an exit for the electromagnetic radiation emanating from the source. The waveguide further includes a surface between the entry and exit portions which permits interaction between the electromagnetic radiation passing through the wave guide and a sample material. A tapered portion forms a part of the entry of the wave guide and couples the electromagnetic radiation emanating from the source to the waveguide. The electromagnetic radiation passing from the exit of the waveguide is captured and directed to a detector for analysis.

  19. Mass Spectrometers in Space!

    NASA Technical Reports Server (NTRS)

    Brinckerhoff, William B.

    2012-01-01

    Exploration of our solar system over several decades has benefitted greatly from the sensitive chemical analyses offered by spaceflight mass spectrometers. When dealing with an unknown environment, the broadband detection capabilities of mass analyzers have proven extremely valuable in determining the composition and thereby the basic nature of space environments, including the outer reaches of Earth s atmosphere, interplanetary space, the Moon, and the planets and their satellites. Numerous mass analyzer types, including quadrupole, monopole, sector, ion trap, and time-of-flight have been incorporated in flight instruments and delivered robotically to a variety of planetary environments. All such instruments went through a rigorous process of application-specific development, often including significant miniaturization, testing, and qualification for the space environment. Upcoming missions to Mars and opportunities for missions to Venus, Europa, Saturn, Titan, asteroids, and comets provide new challenges for flight mass spectrometers that push to state of the art in fundamental analytical technique. The Sample Analysis at Mars (SAM) investigation on the recently-launch Mars Science Laboratory (MSL) rover mission incorporates a quadrupole analyzer to support direct evolved gas as well as gas chromatograph-based analysis of martian rocks and atmosphere, seeking signs of a past or present habitable environment. A next-generation linear ion trap mass spectrometer, using both electron impact and laser ionization, is being incorporated into the Mars Organic Molecule Analyzer (MOMA) instrument, which will be flown to Mars in 2018. These and other mass spectrometers and mission concepts at various stages of development will be described.

  20. Fourier Transform Spectrometer

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Understanding the global atmospheric changes is difficult with today's current technology. However, with high resolution and nearly continuous observations from a satellite, it's possible to transform our understanding of the atmosphere. To enable the next generation of atmospheric science, a new class of orbiting atmospheric sensors is being developed. The foundation of this advanced concept is the Fourier Transform Spectrometer, or FTS.

  1. Recombinant expression, purification, crystallization and preliminary X-ray diffraction analysis of the C-terminal DUF490963–1138 domain of TamB from Escherichia coli

    PubMed Central

    Josts, Inokentijs; Grinter, Rhys; Kelly, Sharon M.; Mosbahi, Khedidja; Roszak, Aleksander; Cogdell, Richard; Smith, Brian O.; Byron, Olwyn; Walker, Daniel

    2014-01-01

    TamB is a recently described inner membrane protein that, together with its partner protein TamA, is required for the efficient secretion of a subset of autotransporter proteins in Gram-negative bacteria. In this study, the C-terminal DUF490963–1138 domain of TamB was overexpressed in Escherichia coli K-12, purified and crystallized using the sitting-drop vapour-diffusion method. The crystals belonged to the primitive trigonal space group P3121, with unit-cell parameters a = b = 57.34, c = 220.74 Å, and diffracted to 2.1 Å resolution. Preliminary secondary-structure and X-ray diffraction analyses are reported. Two molecules are predicted to be present in the asymmetric unit. Experimental phasing using selenomethionine-labelled protein will be undertaken in the future. PMID:25195908

  2. Tropospheric and Airborne Emission Spectrometers

    NASA Technical Reports Server (NTRS)

    Glavich, Thomas; Beer, Reinhard

    1996-01-01

    X This paper describes the development of two related instruments, the Tropospheric Emission Spectrometer (TES) and the Airborne Emission Spectrometer (AES). Both instruments are infrared imaging Fourier Transform Spectrometers, used for measuring the state of the lower atmosphere, and in particular the measurement of ozone and ozone sources and sinks.

  3. Accelerator Mass Spectrometry Analysis of Ultra-Low-Level 129I in Carrier-Free AgI-AgCl Sputter Targets

    NASA Astrophysics Data System (ADS)

    Liu, Qi; Hou, Xiaolin; Zhou, Weijian; Fu, Yunchong

    2015-05-01

    Separation of carrier-free iodine from low-level iodine samples and accurate measurement of ultra-low-level 129I in microgram iodine target are essential but a bottleneck in geology and environment research using naturally produced 129I. This article presents a detection technique of accelerator mass spectrometry (AMS) for accurate determination of ultra-low-level 129I in carrier-free AgI-AgCl sputter targets. Copper instead of aluminum was selected as the suitable sample holder material to avoid the reaction of AgI-AgCl powder with aluminum. Niobium powder was selected as thermally and electrically conductive matrix to be mixed with AgI-AgCl powder, in order to obtain and maintain a stable and high iodine ion current intensity, as well as less memory effect and low background level of 129I. The most optimal ratio of the Nb matrix to the AgI-AgCl powder was found to be 5:1 by mass. The typical current of 127I5+ using AgI-AgCl targets with iodine content from 5 to 80 μg was measured to be 5 to 100 nA. Four-year AMS measurements of the 129I/127I ratios in standards of low iodine content and the machine blanks showed a good repeatability and stability.

  4. Accelerator mass spectrometry analysis of ultra-low-level (129)I in carrier-free AgI-AgCl sputter targets.

    PubMed

    Liu, Qi; Hou, Xiaolin; Zhou, Weijian; Fu, Yunchong

    2015-05-01

    Separation of carrier-free iodine from low-level iodine samples and accurate measurement of ultra-low-level (129)I in microgram iodine target are essential but a bottleneck in geology and environment research using naturally produced (129)I. This article presents a detection technique of accelerator mass spectrometry (AMS) for accurate determination of ultra-low-level (129)I in carrier-free AgI-AgCl sputter targets. Copper instead of aluminum was selected as the suitable sample holder material to avoid the reaction of AgI-AgCl powder with aluminum. Niobium powder was selected as thermally and electrically conductive matrix to be mixed with AgI-AgCl powder, in order to obtain and maintain a stable and high iodine ion current intensity, as well as less memory effect and low background level of (129)I. The most optimal ratio of the Nb matrix to the AgI-AgCl powder was found to be 5:1 by mass. The typical current of (127)I(5+) using AgI-AgCl targets with iodine content from 5 to 80 μg was measured to be 5 to 100 nA. Four-year AMS measurements of the (129)I/(127)I ratios in standards of low iodine content and the machine blanks showed a good repeatability and stability. PMID:25743113

  5. Accelerator mass spectrometry analysis of 14C-oxaliplatin concentrations in biological samples and 14C contents in biological samples and antineoplastic agents

    NASA Astrophysics Data System (ADS)

    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.

  6. Towards biomarker-dependent individualized chemotherapy: exploring cell-specific differences in oxaliplatin-DNA adduct distribution using accelerator mass spectrometry.

    PubMed

    Hah, Sang Soo; Henderson, Paul T; Turteltaub, Kenneth W

    2010-04-15

    Oxaliplatin is a third-generation platinum-based anticancer drug that is currently used in the treatment of metastatic colorectal cancer. Oxaliplatin, like other platinum-based anticancer drugs such as cisplatin and carboplatin, is known to induce apoptosis in tumor cells by binding to nuclear DNA, forming monoadducts, and intra- and interstrand diadducts. Previously, we reported an accelerator mass spectrometry (AMS) assay to measure the kinetics of oxaliplatin-induced DNA damage and repair [Hah, S. S.; Sumbad, R. A.; de Vere White, R. W.; Turteltaub, K. W.; Henderson, P. T. Chem. Res. Toxicol.2007, 20, 1745]. Here, we describe another application of AMS to the measurement of oxaliplatin-DNA adduct distribution in cultured platinum-sensitive testicular (833K) and platinum-resistant breast (MDA-MB-231) cancer cells, which resulted in elucidation of cell-dependent differentiation of oxaliplatin-DNA adduct formation, implying that differential adduction and/or accumulation of the drug in cellular DNA may be responsible for the sensitivity of cancer cells to platinum treatment. Ultimately, we hope to use this method to measure the intrinsic platinated DNA adduct repair capacity in cancer patients for use as a biomarker for diagnostics or a predictor of patient outcome.

  7. Effective determination of the long-lived nuclide 41Ca in nuclear reactor bioshield concretes: comparison of liquid scintillation counting and accelerator mass spectrometry.

    PubMed

    Warwick, P E; Croudace, I W; Hillegonds, D J

    2009-03-01

    The routine application of liquid scintillation counting to (41)Ca determination has been hindered by the absence of traceable calibration standards of known (41)Ca activity concentrations. The introduction of the new IRMM (41)Ca mass-spectrometric standards with sufficiently high (41)Ca activities for radiometric detection has partly overcome this although accurate measurement of stable Ca concentrations coupled with precise half-life data are still required to correct the certified (41)Ca:(40)Ca ratios to (41)Ca activity concentrations. In this study, (41)Ca efficiency versus quench curves have been produced using the IRMM standard, and their accuracy validated by comparison with theoretical calculations of (41)Ca efficiencies. Further verification of the technique was achieved through the analysis of (41)Ca in a reactor bioshield core that had been previously investigated for other radionuclide variations. Calcium-41 activity concentrations of up to 25 Bq/g were detected. Accelerator mass spectrometry (AMS) measurements of the same suite of samples showed a very good agreement, providing validation of the procedure. Calcium-41 activity concentrations declined exponentially with distance from the core of the nuclear reactor and correlated well with the predicted neutron flux.

  8. Accelerator mass spectrometry measurements of the 13C (n ,γ )14C and 14N(n ,p )14C cross sections

    NASA Astrophysics Data System (ADS)

    Wallner, A.; Bichler, M.; Buczak, K.; Dillmann, I.; Käppeler, F.; Karakas, A.; Lederer, C.; Lugaro, M.; Mair, K.; Mengoni, A.; Schätzel, G.; Steier, P.; Trautvetter, H. P.

    2016-04-01

    The technique of accelerator mass spectrometry (AMS), offering a complementary tool for sensitive studies of key reactions in nuclear astrophysics, was applied for measurements of the 13C (n ,γ )14C and the 14N(n ,p )14C cross sections, which act as a neutron poison in s -process nucleosynthesis. Solid samples were irradiated at Karlsruhe Institute of Technology with neutrons closely resembling a Maxwell-Boltzmann distribution for k T =25 keV, and also at higher energies between En=123 and 182 keV. After neutron irradiation the produced amount of 14C in the samples was measured by AMS at the Vienna Environmental Research Accelerator (VERA) facility. For both reactions the present results provide important improvements compared to previous experimental data, which were strongly discordant in the astrophysically relevant energy range and missing for the comparably strong resonances above 100 keV. For 13C (n ,γ ) we find a four times smaller cross section around k T =25 keV than a previous measurement. For 14N(n ,p ), the present data suggest two times lower cross sections between 100 and 200 keV than had been obtained in previous experiments and data evaluations. The effect of the new stellar cross sections on the s process in low-mass asymptotic giant branch stars was studied for stellar models of 2 M⊙ initial mass, and solar and 1 /10th solar metallicity.

  9. Accelerator Mass Spectrometry of Actinides in Ground- and Seawater: An Innovative Method Allowing for the Simultaneous Analysis of U, Np, Pu, Am, and Cm Isotopes below ppq Levels.

    PubMed

    Quinto, Francesca; Golser, Robin; Lagos, Markus; Plaschke, Markus; Schäfer, Thorsten; Steier, Peter; Geckeis, Horst

    2015-06-01

    (236)U, (237)Np, and Pu isotopes and (243)Am were determined in ground- and seawater samples at levels below ppq (fg/g) with a maximum sample size of 250 g. Such high sensitivity was possible by using accelerator mass spectrometry (AMS) at the Vienna Environmental Research Accelerator (VERA) with extreme selectivity and recently improved efficiency and a significantly simplified separation chemistry. The use of nonisotopic tracers was investigated in order to allow for the determination of (237)Np and (243)Am, for which isotopic tracers either are rarely available or suffer from various isobaric mass interferences. In the present study, actinides were concentrated from the sample matrix via iron hydroxide coprecipitation and measured sequentially without previous chemical separation from each other. The analytical method was validated by the analysis of the Reference Material IAEA 443 and was applied to groundwater samples from the Colloid Formation and Migration (CFM) project at the deep underground rock laboratory of the Grimsel Test Site (GTS) and to natural water samples affected solely by global fallout. While the precision of the presented analytical method is somewhat limited by the use of nonisotopic spikes, the sensitivity allows for the determination of ∼10(5) atoms in a sample. This provides, e.g., the capability to study the long-term release and retention of actinide tracers in field experiments as well as the transport of actinides in a variety of environmental systems by tracing contamination from global fallout.

  10. Early Upper Paleolithic chronology in the Levant: new ABOx-SC accelerator mass spectrometry results from the Mughr el-Hamamah Site, Jordan.

    PubMed

    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.

  11. Pharmacokinetics, absorption, and excretion of radiolabeled revexepride: a Phase I clinical trial using a microtracer and accelerator mass spectrometry-based approach

    PubMed Central

    Flach, Stephen; Croft, Marie; Ding, Jie; Budhram, Ron; Pankratz, Todd; Pennick, Mike; Scarfe, Graeme; Troy, Steven; Getsy, Jay

    2016-01-01

    Purpose Gastroesophageal reflux disease involves the reflux of gastric and/or duodenal content into the esophagus. Prokinetic therapies, such as the selective 5-hydroxytryptamine receptor 4 agonist revexepride, may aid gastric emptying. This Phase I study evaluated the pharmacokinetics and excretion pathways of [14C]revexepride in healthy individuals using a microtracer approach with accelerator mass spectrometry. Participants and methods Six healthy men received a single oral dose of 2 mg [14C]revexepride containing ~200 nCi of radioactivity; blood, urine, and fecal samples were collected over a 10-day period. Results Almost 100% of 14C was recovered: 38.2%±10.3% (mean ± standard deviation) was recovered in urine, and 57.3%±0.4% was recovered in feces. Blood cell uptake was low, based on the blood plasma total radioactivity ratio of 0.8. The mean revexepride renal clearance was 8.6 L/h, which was slightly higher than the typical glomerular filtration rate in healthy individuals. Time to reach maximal concentration was 1.75±1.17 hours (mean ± standard deviation). No safety signals were identified. Conclusion This study demonstrated that revexepride had rapid and moderate-to-good oral absorption. Excretion of radioactivity was completed with significant amounts in feces and urine. Renal clearance slightly exceeded the typical glomerular filtration rate, suggesting the involvement of active transportation in the renal tubules. PMID:27729771

  12. Alpha Magnetic Spectrometer

    NASA Astrophysics Data System (ADS)

    Ting, Samuel

    2012-07-01

    The Alpha Magnetic Spectrometer (AMS) is a precision particle physics magnetic spectrometer designed to measure electrons, positrons, gamma rays and various nuclei and anti-nuclei from the cosmos up to TeV energy ranges. AMS weighs 7.5 tons and measures 5 meters by 4 meters by 3 meters. It contains 300,000 channels of electronics and 650 onboard microprocessors. It was delivered to the International Space Station onboard space shuttle Endeavour and installed on May 19, 2011. Since that time, more than 14 billion cosmic ray events have been collected. All the detectors function properly. At this moment, we are actively engaged in data analysis. AMS is an international collaboration involving 16 countries and 60 institutes. It took 16 years to construct and test. AMS is the only major physical science experiment on the International Space Station and will continue to collect data over the entire lifetime of the Space Station (10-20 years).

  13. Imaging Fourier Transform Spectrometer

    SciTech Connect

    Bennett, C.L.; Carter, M.R.; Fields, D.J.; Hernandez, J.

    1993-04-14

    The operating principles of an Imaging Fourier Transform Spectrometer (IFTS) are discussed. The advantages and disadvantages of such instruments with respect to alternative imaging spectrometers are discussed. The primary advantages of the IFTS are the capacity to acquire more than an order of magnitude more spectral channels than alternative systems with more than an order of magnitude greater etendue than for alternative systems. The primary disadvantage of IFTS, or FTS in general, is the sensitivity to temporal fluctuations, either random or periodic. Data from the IRIFTS (ir IFTS) prototype instrument, sensitive in the infrared, are presented having a spectral sensitivity of 0.01 absorbance units, a spectral resolution of 6 cm{sup {minus}1} over the range 0 to 7899 cm{sup {minus}1}, and a spatial resolution of 2.5 mr.

  14. FAST NEUTRON SPECTROMETER

    DOEpatents

    Davis, F.J.; Hurst, G.S.; Reinhardt, P.W.

    1959-08-18

    An improved proton recoil spectrometer for determining the energy spectrum of a fast neutron beam is described. Instead of discriminating against and thereby"throwing away" the many recoil protons other than those traveling parallel to the neutron beam axis as do conventional spectrometers, this device utilizes protons scattered over a very wide solid angle. An ovoidal gas-filled recoil chamber is coated on the inside with a scintillator. The ovoidal shape of the sensitive portion of the wall defining the chamber conforms to the envelope of the range of the proton recoils from the radiator disposed within the chamber. A photomultiplier monitors the output of the scintillator, and a counter counts the pulses caused by protons of energy just sufficient to reach the scintillator.

  15. Surface Plasmon Based Spectrometer

    NASA Astrophysics Data System (ADS)

    Wig, Andrew; Passian, Ali; Boudreaux, Philip; Ferrell, Tom

    2008-03-01

    A spectrometer that uses surface plasmon excitation in thin metal films to separate light into its component wavelengths is described. The use of surface plasmons as a dispersive medium sets this spectrometer apart from prism, grating, and interference based variants and allows for the miniaturization of this device. Theoretical and experimental results are presented for two different operation models. In the first case surface plasmon tunneling in the near field is used to provide transmission spectra of different broad band-pass, glass filters across the visible wavelength range with high stray-light rejection at low resolution as well as absorption spectra of chlorophyll extracted from a spinach leaf. The second model looks at the far field components of surface plasmon scattering.

  16. Miniaturized Ion Mobility Spectrometer

    NASA Technical Reports Server (NTRS)

    Kaye, William J. (Inventor); Stimac, Robert M. (Inventor)

    2015-01-01

    By utilizing the combination of a unique electronic ion injection control circuit in conjunction with a particularly designed drift cell construction, the instantly disclosed ion mobility spectrometer achieves increased levels of sensitivity, while achieving significant reductions in size and weight. The instant IMS is of a much simpler and easy to manufacture design, rugged and hermetically sealed, capable of operation at high temperatures to at least 250.degree. C., and is uniquely sensitive, particularly to explosive chemicals.

  17. Rapid scanning mass spectrometer

    SciTech Connect

    Leckey, J.H.; Boeckmann, M.D.

    1996-11-25

    Mass spectrometers and residual gas analyzers (RGA) are used in a variety of applications for analysis of volatile and semi-volatile materials. Analysis is performed by detecting fragments of gas molecules, based on their mass to charge ratio, which are generated in the mass spectrometer. When used as a detector for a gas chromatograph, they function as a means to quantitatively identify isolated volatile species which have been separated from other species via the gas chromatograph. Vacuum Technology, Inc., (VTI) produces a magnetic sector mass spectrometer/RGA which is used in many industrial and laboratory environments. In order to increase the utility of this instrument, it is desirable to increase the mass scanning speed, thereby increasing the number of applications for which it is suited. This project performed the following three upgrades on the computer interface. (1) A new electrometer was designed and built to process the signal from the detector. This new electrometer is more sensitive, over 10 times faster, and over 100 times more stable than the electrometer it will replace. (2) The controller EPROM was reprogrammed with new firmware. This firmware acts as an operating system for the interface and is used to shuttle communications between the PC and the AEROVAC mass spectrometer. (3) The voltage regulator which causes the ion selector voltage to ramp to allow ions of selected mass to be sequentially detected was redesigned and prototyped. The redesigned voltage regulator can be ramped up or down more than 100 times faster than the existing regulator. These changes were incorporated into a prototype unit and preliminary performance testing conducted. Results indicated that scanning speed was significantly increased over the unmodified version.

  18. X-ray Spectrometer

    NASA Technical Reports Server (NTRS)

    Porter, F. Scott

    2004-01-01

    The X-ray Spectrometer (XRS) instrument is a revolutionary non-dispersive spectrometer that will form the basis for the Astro-E2 observatory to be launched in 2005. We have recently installed a flight spare X R S microcalorimeter spectrometer at the EBIT-I facility at LLNL replacing the XRS from the earlier Astro-E mission and providing twice the resolution. The X R S microcalorimeter is an x-ray detector that senses the heat deposited by the incident photon. It achieves a high energy resolution by operating at 0.06K and by carefully controlling the heat capacity and thermal conductance. The XRS/EBIT instrument has 32 pixels in a square geometry and achieves an energy resolution of 6 eV at 6 keV, with a bandpass from 0.1 to 12 keV (or more at higher operating temperature). The instrument allows detailed studies of the x-ray line emission of laboratory plasmas. The XRS/EBIT also provides an extensive calibration "library" for the Astro-E2 observatory.

  19. Mass spectrometers: instrumentation

    NASA Astrophysics Data System (ADS)

    Cooks, R. G.; Hoke, S. H., II; Morand, K. L.; Lammert, S. A.

    1992-09-01

    Developments in mass spectrometry instrumentation over the past three years are reviewed. The subject is characterized by an enormous diversity of designs, a high degree of competition between different laboratories working with either different or similar techniques and by extremely rapid progress in improving analytical performance. Instruments can be grouped into genealogical charts based on their physical and conceptual interrelationships. This is illustrated using mass analyzers of different types. The time course of development of particular instrumental concepts is illustrated in terms of the s-curves typical of cell growth. Examples are given of instruments which are at the exponential, linear and mature growth stages. The prime examples used are respectively: (i) hybrid instruments designed to study reactive collisions of ions with surfaces: (ii) the Paul ion trap; and (iii) the triple quadrupole mass spectrometer. In the area of ion/surface collisions, reactive collisions such as hydrogen radical abstraction from the surface by the impinging ion are studied. They are shown to depend upon the chemical nature of the surface through the use of experiments which utilize self-assembled monolayers as surfaces. The internal energy deposited during surface-induced dissociation upon collision with different surfaces in a BEEQ instrument is also discussed. Attention is also given to a second area of emerging instrumentation, namely technology which allows mass spectrometers to be used for on-line monitoring of fluid streams. A summary of recent improvements in the performance of the rapidly developing quadrupole ion trap instrument illustrates this stage of instrument development. Improvements in resolution and mass range and their application to the characterization of biomolecules are described. The interaction of theory with experiment is illustrated through the role of simulations of ion motion in the ion trap. It is emphasized that mature instruments play a

  20. Determination of ultralow level 129I/127I in natural samples by separation of microgram carrier free iodine and accelerator mass spectrometry detection.

    PubMed

    Hou, Xiaolin; Zhou, Weijian; Chen, Ning; Zhang, Luyuan; Liu, Qi; Luo, Maoyi; Fan, Yukun; Liang, Wangguo; Fu, Yunchong

    2010-09-15

    Separation of carrier free iodine from low iodine level samples and accurate measurement of ultralow level (129)I in micrograms of iodine target are essential but a bottleneck in geological dating of terrestrial system and tracer research using naturally produced (129)I. 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 spectrometry was used to measure ultralow level (129)I in micrograms of iodine target. The recovery of iodine in the entire separation procedure is higher than 80% and 65% for solid and water samples, respectively. One microgram iodine in the target (AgI-AgCl) can produce a stable (127)I signal for AMS measurement of (129)I/(127)I, and a detection limit of this method for (129)I is calculated to be 10(5) atoms. This will allow us to accurately determine (129)I in prenuclear geological samples of low iodine concentration with (129)I/(127)I of 10(-12), such as loess, soil, coral, rock, sediment, and groundwater. Some samples with low iodine content have been successfully analyzed, and the lowest value of the (129)I/(127)I ratio of 2 × 10(-11) was observed in 23.5 and 63.5 m loess samples collected in the Loess Plateau, China. The developed method sheds light on a wide application in earth science. PMID:20735008

  1. Assessing the Intention to Use Technology among Pre-Service Teachers in Singapore and Malaysia: A Multigroup Invariance Analysis of the Technology Acceptance Model (TAM)

    ERIC Educational Resources Information Center

    Teo, Timothy; Lee, Chwee Beng; Chai, Ching Sing; Wong, Su Luan

    2009-01-01

    This study assesses the pre-service teachers' self-reported future intentions to use technology in Singapore and Malaysia. A survey was employed to validate items from past research. Using the Technology Acceptance Model (TAM) as a research framework, 495 pre-service teachers from Singapore and Malaysia responded to an 11-item questionnaires…

  2. Exploring Attitudes towards Computer Use among Pre-Service Teachers from Singapore and the UK: A Multi-Group Invariance Test of the Technology Acceptance Model (TAM)

    ERIC Educational Resources Information Center

    Teo, Timothy; Noyes, Jan

    2010-01-01

    Purpose: This paper aims to compare the pre-service teachers from Singapore and the UK on their self-reported attitude towards computer use (ATCU) by employing the technology acceptance model (TAM) as the research framework. Design/methodology/approach: In total, 395 pre-service teachers completed a survey questionnaire measuring their responses…

  3. MASS SPECTROMETER LEAK

    DOEpatents

    Shields, W.R.

    1960-10-18

    An improved valve is described for precisely regulating the flow of a sample fluid to be analyzed, such as in a mass spectrometer, where a gas sample is allowed to "leak" into an evacuated region at a very low, controlled rate. The flow regulating valve controls minute flow of gases by allowing the gas to diffuse between two mating surfaces. The structure of the valve is such as to prevent the corrosive feed gas from contacting the bellows which is employed in the operation of the valve, thus preventing deterioration of the bellows.

  4. Modular total absorption spectrometer

    NASA Astrophysics Data System (ADS)

    Karny, M.; Rykaczewski, K. P.; Fijałkowska, A.; Rasco, B. C.; Wolińska-Cichocka, M.; Grzywacz, R. K.; Goetz, K. C.; Miller, D.; Zganjar, E. F.

    2016-11-01

    The design and performance of the Modular Total Absorption Spectrometer built and commissioned at the Oak Ridge National Laboratory is presented. The active volume of the detector is approximately one ton of NaI(Tl), which results in very high full γ energy peak efficiency of 71% at 6 MeV and nearly flat efficiency of around 81.5% for low energy γ-rays between 300 keV and 1 MeV. In addition to the high peak efficiency, the modular construction of the detector permits the use of a γ-coincidence technique in data analysis as well as β-delayed neutron observation.

  5. Automated transportable mass spectrometer

    NASA Astrophysics Data System (ADS)

    Echo, M. W.

    1981-09-01

    The need was identified for a mass spectrometer (MS) which can be conveniently transported among several facilities for rapid verification of the isotopic composition of special nuclear material. This requirement for a light weight, transportable MS for U and Pu mass analysis was met by deleting the gas chromograph (GC) portions of a Hewlett-Packard Model 5992 Quadrupole GCMS and substituting a vacuum lock sample entry system. A programmable power supply and vacuum gauge were added and circuitry modifications were made to enable use of the supplied software.

  6. Gas Chromatic Mass Spectrometer

    NASA Technical Reports Server (NTRS)

    Wey, Chowen

    1995-01-01

    Gas chromatograph/mass spectrometer (GC/MS) used to measure and identify combustion species present in trace concentration. Advanced extractive diagnostic method measures to parts per billion (PPB), as well as differentiates between different types of hydrocarbons. Applicable for petrochemical, waste incinerator, diesel transporation, and electric utility companies in accurately monitoring types of hydrocarbon emissions generated by fuel combustion, in order to meet stricter environmental requirements. Other potential applications include manufacturing processes requiring precise detection of toxic gaseous chemicals, biomedical applications requiring precise identification of accumulative gaseous species, and gas utility operations requiring high-sensitivity leak detection.

  7. Vitamin K-dependent proteins GAS6 and Protein S and TAM receptors in patients of systemic lupus erythematosus: correlation with common genetic variants and disease activity

    PubMed Central

    2013-01-01

    Introduction Growth arrest-specific gene 6 protein (GAS6) and protein S (ProS) are vitamin K-dependent proteins present in plasma with important regulatory functions in systems of response and repair to damage. They interact with receptor tyrosine kinases of the Tyro3, Axl and MerTK receptor tyrosine kinase (TAM) family, involved in apoptotic cell clearance (efferocytosis) and regulation of the innate immunity. TAM-deficient mice show spontaneous lupus-like symptoms. Here we tested the genetic profile and plasma levels of components of the system in patients with systemic lupus erythematosus (SLE), and compare them with a control healthy population. Methods Fifty SLE patients and 50 healthy controls with matched age, gender and from the same geographic area were compared. Genetic analysis was performed in GAS6 and the TAM receptor genes on SNPs previously identified. The concentrations of GAS6, total and free ProS, and the soluble forms of the three TAM receptors (sAxl, sMerTK and sTyro3) were measured in plasma from these samples. Results Plasma concentrations of GAS6 were higher and, total and free ProS were lower in the SLE patients compared to controls, even when patients on oral anticoagulant treatment were discarded. Those parameters correlated with SLE disease activity index (SLEDAI) score, GAS6 being higher in the most severe cases, while free and total ProS were lower. All 3 soluble receptors increased its concentration in plasma of lupus patients. Conclusions The present study highlights that the GAS6/ProS-TAM system correlates in several ways with disease activity in SLE. We show here that this correlation is affected by common polymorphisms in the genes of the system. These findings underscore the importance of mechanism of regulatory control of innate immunity in the pathology of SLE. PMID:23497733

  8. Qualitative and quantitative trait loci conditioning resistance to Puccinia coronata pathotypes NQMG and LGCG in the oat (Avena sativa L.) cultivars Ogle and TAM O-301.

    PubMed

    Jackson, E W; Obert, D E; Menz, M; Hu, G; Bonman, J M

    2008-02-01

    Mapping disease resistance loci relies on the type and precision of phenotypic measurements. For crown rust of oat, disease severity is commonly assessed based on visual ratings of infection types (IT) and/or diseased leaf area (DLA) of infected plants in the greenhouse or field. These data can be affected by several variables including; (i) non-uniform disease development in the field; (ii) atypical symptom development in the greenhouse; (iii) the presence of multiple pathogenic races or pathotypes in the field, and (iv) rating bias. To overcome these limitations, we mapped crown rust resistance to single isolates in the Ogle/TAM O-301 (OT) recombinant inbred line (RIL) population using detailed measurements of IT, uredinia length (UL) and relative fungal DNA (FDNA) estimates determined by q-PCR. Measurements were taken on OT parents and recombinant inbred lines (RIL) inoculated with Puccinia coronata pathotypes NQMG and LGCG in separate greenhouse and field tests. Qualitative mapping identified an allele conferred by TAM O-301 on linkage group (LG) OT-11, which produced a bleached fleck phenotype to both NQMG and LGCG. Quantitative mapping identified two major quantitative trait loci (QTL) originating from TAM O-301 on LGs OT-11 and OT-32 which reduced UL and FDNA of both isolates in all experiments. Additionally, minor QTLs that reduced UL and FDNA were detected on LGs OT-15 and OT-8, originating from TAM O-301, and on LG OT-27, originating from Ogle. Detailed assessments of the OT population using two pathotypes in both the greenhouse and field provided comprehensive information to effectively map the genes responsible for crown rust resistance in Ogle and TAM O-301 to NQMG and LGCG.

  9. Optical fiber interferometric spectrometer

    NASA Astrophysics Data System (ADS)

    Liu, Yong; Li, Baosheng; Liu, Yan; Zhai, Yufeng; Wang, An

    2006-02-01

    We design an optical fiber spectrometer based on optical fiber Mach-Zehnder interferometer. In optical fiber Fourier transform spectrometer spectra information is obtained by Fourier transform of interferogram, which recording intensity change vs. optical path difference. Optical path difference is generated by stretching one fiber arm which wound around fiber stretch drive by high power supply. Information from detector is linear with time rather than with optical path difference. In order to obtain high accuracy wavenumber, reference beam is used to control the optical path difference. Optical path difference is measured by reference laser interference fringe. Interferogram vs. optical path difference is resampled by Brault algorithm with information from reference beam and test beam. In the same condition, one-sided interferogram has higher resolution than that of two-sided interferogram. For one-sided interferogram, zero path difference position must be determined as accurately as possible, small shift will result in phase error. For practical experiment in laboratory, position shift is inevitable, so phase error correction must be considered. Zero order fringe is determined by curve fitting. Spectrum of light source is obtained from one-sided interferogram by Fourier cosine transform. A spectral resolution of about ~3.1 cm -1 is achieved. In practice, higher resolution is needed. This compact equipment will be used in emission spectra and absorption spectra, especially in infrared region.

  10. Resonant ultrasound spectrometer

    DOEpatents

    Migliori, Albert; Visscher, William M.; Fisk, Zachary

    1990-01-01

    An ultrasound resonant spectrometer determines the resonant frequency spectrum of a rectangular parallelepiped sample of a high dissipation material over an expected resonant response frequency range. A sample holder structure grips corners of the sample between piezoelectric drive and receive transducers. Each transducer is mounted on a membrane for only weakly coupling the transducer to the holder structure and operatively contacts a material effective to remove system resonant responses at the transducer from the expected response range. i.e., either a material such as diamond to move the response frequencies above the range or a damping powder to preclude response within the range. A square-law detector amplifier receives the response signal and retransmits the signal on an isolated shield of connecting cabling to remove cabling capacitive effects. The amplifier also provides a substantially frequency independently voltage divider with the receive transducer. The spectrometer is extremely sensitive to enable low amplitude resonance to be detected for use in calculating the elastic constants of the high dissipation sample.

  11. ISS Update: Alpha Magnetic Spectrometer

    NASA Video Gallery

    NASA Public Affairs Officer Kelly Humphries interviews Trent Martin, Johnson Space Center project manager for the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station. Questions...

  12. Quantification of absorption, retention and elimination of two different oral doses of vitamin A in Zambian boys using accelerator mass spectrometry

    SciTech Connect

    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.

  13. Determination of the Tissue Distribution and Excretion by Accelerator Mass Spectrometry of the Nonadecapeptide 14C-Moli1901 in Beagle dogs after Intratracheal Instillation

    SciTech Connect

    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.

  14. Photo ion spectrometer

    DOEpatents

    Gruen, D.M.; Young, C.E.; Pellin, M.J.

    1989-12-26

    A charged particle spectrometer is described for performing ultrasensitive quantitative analysis of selected atomic components removed from a sample. Significant improvements in performing energy and angular refocusing spectroscopy are accomplished by means of a two dimensional structure for generating predetermined electromagnetic field boundary conditions. Both resonance and non-resonance ionization of selected neutral atomic components allow accumulation of increased chemical information. A multiplexed operation between a SIMS mode and a neutral atomic component ionization mode with EARTOF analysis enables comparison of chemical information from secondary ions and neutral atomic components removed from the sample. An electronic system is described for switching high level signals, such as SIMS signals, directly to a transient recorder and through a charge amplifier to the transient recorder for a low level signal pulse counting mode, such as for a neutral atomic component ionization mode. 12 figs.

  15. Optical fiber smartphone spectrometer.

    PubMed

    Hossain, Md Arafat; Canning, John; Cook, Kevin; Jamalipour, Abbas

    2016-05-15

    An optical fiber-based smartphone spectrometer incorporating an endoscopic fiber bundle is demonstrated. The endoscope allows transmission of the smartphone camera LED light to a sample, removing complications from varying background illumination. The reflected spectra collected from a surface or interface is dispersed onto the camera CMOS using a reflecting diffraction grating. A spectral resolution as low as δλ∼2.0  nm over a bandwidth of Δλ∼250  nm is obtained using a slit width, ωslit=0.7  mm. The instrument has vast potential in a number of industrial applications including agricultural produce analysis. Spectral analysis of apples shows straightforward measurement of the pigments anthocyanins, carotenoid, and chlorophyll, all of which decrease with increasing storage time. PMID:27176971

  16. Photo ion spectrometer

    DOEpatents

    Gruen, Dieter M.; Young, Charles E.; Pellin, Michael J.

    1989-01-01

    A charged particle spectrometer for performing ultrasensitive quantitative analysis of selected atomic components removed from a sample. Significant improvements in performing energy and angular refocusing spectroscopy are accomplished by means of a two dimensional structure for generating predetermined electromagnetic field boundary conditions. Both resonance and non-resonance ionization of selected neutral atomic components allow accumulation of increased chemical information. A multiplexed operation between a SIMS mode and a neutral atomic component ionization mode with EARTOF analysis enables comparison of chemical information from secondary ions and neutral atomic components removed from the sample. An electronic system is described for switching high level signals, such as SIMS signals, directly to a transient recorder and through a charge amplifier to the transient recorder for a low level signal pulse counting mode, such as for a neutral atomic component ionization mode.

  17. Coastal Research Imaging Spectrometer

    NASA Technical Reports Server (NTRS)

    Lucey, Paul G.; Williams, Timothy; Horton, Keith A.

    2002-01-01

    The Coastal Research Imaging Spectrometer (CRIS) is an airborne remote-sensing system designed specifically for research on the physical, chemical, and biological characteristics of coastal waters. The CRIS includes a visible-light hyperspectral imaging subsystem for measuring the color of water, which contains information on the biota, sediment, and nutrient contents of the water. The CRIS also includes an infrared imaging subsystem, which provides information on the temperature of the water. The combination of measurements enables investigation of biological effects of both natural and artificial flows of water from land into the ocean, including diffuse and point-source flows that may contain biological and/or chemical pollutants. Temperature is an important element of such measurements because temperature contrasts can often be used to distinguish among flows from different sources: for example, a sewage outflow could manifest itself in spectral images as a local high-temperature anomaly.

  18. Lunar orbital mass spectrometer experiment

    NASA Technical Reports Server (NTRS)

    Lord, W. P.

    1971-01-01

    The design, development, manufacture, test and calibration of five lunar orbital mass spectrometers with the four associated ground support equipment test sets are discussed. A mass spectrometer was installed in the Apollo 15 and one in the Apollo 16 Scientific Instrument Module within the Service Module. The Apollo 15 mass spectrometer was operated with collection of 38 hours of mass spectra data during lunar orbit and 50 hours of data were collected during transearth coast. The Apollo 16 mass spectrometer was operated with collection of 76 hours of mass spectra data during lunar orbit. However, the Apollo 16 mass spectrometer was ejected into lunar orbit upon malfunction of spacecraft boom system just prior to transearth insection and no transearth coast data was possible.

  19. Photo-induced depopulation of the 180Tam isomer via low-lying intermediate states: Structure and astrophysical implications

    NASA Astrophysics Data System (ADS)

    Belic, D.; Arlandini, C.; Besserer, J.; de Boer, J.; Carroll, J. J.; Enders, J.; Hartmann, T.; Käppeler, F.; Kaiser, H.; Kneissl, U.; Kolbe, E.; Langanke, K.; Loewe, M.; Maier, H. J.; Maser, H.; Mohr, P.; von Neumann-Cosel, P.; Nord, A.; Pitz, H. H.; Richter, A.; Schumann, M.; Thielemann, F.-K.; Volz, S.; Zilges, A.

    2002-03-01

    The photo-induced depopulation of the quasistable isomer (t1/2>=1.2×1015 yr) in 180Ta with angular momentum and parity Jπ=9- at an excitation energy Ex=75 keV was studied at the new bremsstrahlung irradiation facility installed at the Stuttgart 4.3 MV DYNAMITRON accelerator in the energy range of bremsstrahlung end point energies between E0=0.8-3.1 MeV. The onset of the isomer depopulation could be observed starting at an end point energy of E0~1 MeV, i.e., at an intermediate state of 180Ta at or below that energy. Higher-lying intermediate states were found at 1.22, 1.43, 1.55, 1.85, 2.16, 2.40, 2.64, and 2.80 MeV. The extracted integrated cross sections show a remarkably strong depopulation of the 180Tam isomer by photoexcitation. The results are compared with previous experiments and recent quasiparticle-phonon model calculations. Implications of the results for a possible nucleosynthesis of 180Ta in the s process and the neutrino process are discussed.

  20. VEGAS: VErsatile GBT Astronomical Spectrometer

    NASA Astrophysics Data System (ADS)

    Bussa, Srikanth; VEGAS Development Team

    2012-01-01

    The National Science Foundation Advanced Technologies and Instrumentation (NSF-ATI) program is funding a new spectrometer backend for the Green Bank Telescope (GBT). This spectrometer is being built by the CICADA collaboration - collaboration between the National Radio Astronomy Observatory (NRAO) and the Center for Astronomy Signal Processing and Electronics Research (CASPER) at the University of California Berkeley.The backend is named as VErsatile GBT Astronomical Spectrometer (VEGAS) and will replace the capabilities of the existing spectrometers. This backend supports data processing from focal plane array systems. The spectrometer will be capable of processing up to 1.25 GHz bandwidth from 8 dual polarized beams or a bandwidth up to 10 GHz from a dual polarized beam.The spectrometer will be using 8-bit analog to digital converters (ADC), which gives a better dynamic range than existing GBT spectrometers. There will be 8 tunable digital sub-bands within the 1.25 GHz bandwidth, which will enhance the capability of simultaneous observation of multiple spectral transitions. The maximum spectral dump rate to disk will be about 0.5 msec. The vastly enhanced backend capabilities will support several science projects with the GBT. The projects include mapping temperature and density structure of molecular clouds; searches for organic molecules in the interstellar medium; determination of the fundamental constants of our evolving Universe; red-shifted spectral features from galaxies across cosmic time and survey for pulsars in the extreme gravitational environment of the Galactic Center.

  1. Photo ion spectrometer

    DOEpatents

    Gruen, D.M.; Young, C.E.; Pellin, M.J.

    1989-08-08

    A method and apparatus are described for extracting for quantitative analysis ions of selected atomic components of a sample. A lens system is configured to provide a slowly diminishing field region for a volume containing the selected atomic components, enabling accurate energy analysis of ions generated in the slowly diminishing field region. The lens system also enables focusing on a sample of a charged particle beam, such as an ion beam, along a path length perpendicular to the sample and extraction of the charged particles along a path length also perpendicular to the sample. Improvement of signal to noise ratio is achieved by laser excitation of ions to selected auto-ionization states before carrying out quantitative analysis. Accurate energy analysis of energetic charged particles is assured by using a preselected resistive thick film configuration disposed on an insulator substrate for generating predetermined electric field boundary conditions to achieve for analysis the required electric field potential. The spectrometer also is applicable in the fields of SIMS, ISS and electron spectroscopy. 8 figs.

  2. The OPERA muon spectrometers

    NASA Astrophysics Data System (ADS)

    Garfagnini, A.; Bergnoli, A.; Brugnera, R.; Carrara, E.; Ciesielski, R.; Dal Corso, F.; Dusini, S.; Fanin, C.; Longhin, A.; Stanco, L.; Cazes, A.; Cecchetti, A.; Di Troia, C.; Dulach, B.; Felici, G.; Mengucci, A.; Orecchini, D.; Paoloni, A.; Spinetti, M.; Terranova, F.; Ventura, M.; Votano, L.; Candela, A.; D'Incecco, M.; Gustavino, C.; Lindozzi, M.

    2007-03-01

    The OPERA experiment will study νμ to ντ oscillations through τ appearance on the 732 km long CERN to Gran Sasso baseline. The magnet yokes of the two muon spectrometers are instrumented with 48 planes of high resistivity bakelite Resistive Plate Chambers (RPC) operated in streamer mode. Each plane covers about 70 m2. A general introduction to the system installation and commissioning will be given. Four RPC planes were instrumented and the first tests were performed confirming a good behavior of the installed RPCs in terms of intrinsic noise and operating currents. The measured noise maps agree with those obtained in the extensive quality test performed at surface. Counting rates are below 20 Hz/m2. Single and multiple cosmic muon tracks were also reconstructed. The estimated efficiency is close to the geometrical limit and the very first measurements of the absolute and differential muon flux are in agreement with the expectations. Finally, a description of the readout electronics and of the slow control system is given.

  3. Mesospheric aerosol sampling spectrometer

    NASA Astrophysics Data System (ADS)

    Knappmiller, Scott; Robertson, Scott; Sternovsky, Zoltan; Horanyi, Mihaly; Kohnert, Rick

    . The Mesospheric Aerosol Sampling Spectrometer (MASS) instrument has been launched on two sounding rockets in August, 2007 from Andoya, Norway to detect charged sub-visible aerosol particles in the polar mesosphere. The MASS instrument is designed to collect charged aerosols, cluster ions, and electrons on four pairs of graphite electrodes, three of which are biased with increasing voltage. The design of the MASS instrument was complicated by the short mean free path in the mesosphere. The opening to MASS was deliberately built to increase the mean free path and to reduce the shock wave within the instrument. The design procedure began with aerodynamics simulations of the flow through the instrument using Direct Simulation Monte Carlo (DSMC) in 3-D. The electric fields within the instrument were calculated using a Laplace solver in 3-D. With the aerodynamic and electric field simulations completed, an algorithm was created to find the trajectories of charged aerosols including collisions within MASS. Using this algorithm the collection efficiencies for each electrode was calculated as a function of the charge to mass ratio of the incoming particle. The simulation results have been confirmed experimentally using an Argon RF ion beam. The data from the August launches have been analyzed and the initial results show the MASS instrument operated as expected. Additional studies are underway to determine if there were effects from payload charging or spurious charge generation within the instrument. This project is supported by NASA.

  4. Neutron range spectrometer

    DOEpatents

    Manglos, Stephen H.

    1989-06-06

    A neutron range spectrometer and method for determining the neutron energy spectrum of a neutron emitting source are disclosed. Neutrons from the source are collimnated along a collimation axis and a position sensitive neutron counter is disposed in the path of the collimated neutron beam. The counter determines positions along the collimation axis of interactions between the neutrons in the neutron beam and a neutron-absorbing material in the counter. From the interaction positions, a computer analyzes the data and determines the neutron energy spectrum of the neutron beam. The counter is preferably shielded and a suitable neutron-absorbing material is He-3. The computer solves the following equation in the analysis: ##EQU1## where: N(x).DELTA.x=the number of neutron interactions measured between a position x and x+.DELTA.x, A.sub.i (E.sub.i).DELTA.E.sub.i =the number of incident neutrons with energy between E.sub.i and E.sub.i +.DELTA.E.sub.i, and C=C(E.sub.i)=N .sigma.(E.sub.i) where N=the number density of absorbing atoms in the position sensitive counter means and .sigma. (E.sub.i)=the average cross section of the absorbing interaction between E.sub.i and E.sub.i +.DELTA.E.sub.i.

  5. Photo ion spectrometer

    DOEpatents

    Gruen, Dieter M.; Young, Charles E.; Pellin, Michael J.

    1989-01-01

    A method and apparatus for extracting for quantitative analysis ions of selected atomic components of a sample. A lens system is configured to provide a slowly diminishing field region for a volume containing the selected atomic components, enabling accurate energy analysis of ions generated in the slowly diminishing field region. The lens system also enables focusing on a sample of a charged particle beam, such as an ion beam, along a path length perpendicular to the sample and extraction of the charged particles along a path length also perpendicular to the sample. Improvement of signal to noise ratio is achieved by laser excitation of ions to selected autoionization states before carrying out quantitative analysis. Accurate energy analysis of energetic charged particles is assured by using a preselected resistive thick film configuration disposed on an insulator substrate for generating predetermined electric field boundary conditions to achieve for analysis the required electric field potential. The spectrometer also is applicable in the fields of SIMS, ISS and electron spectroscopy.

  6. Aerosol mobility size spectrometer

    DOEpatents

    Wang, Jian; Kulkarni, Pramod

    2007-11-20

    A device for measuring aerosol size distribution within a sample containing aerosol particles. The device generally includes a spectrometer housing defining an interior chamber and a camera for recording aerosol size streams exiting the chamber. The housing includes an inlet for introducing a flow medium into the chamber in a flow direction, an aerosol injection port adjacent the inlet for introducing a charged aerosol sample into the chamber, a separation section for applying an electric field to the aerosol sample across the flow direction and an outlet opposite the inlet. In the separation section, the aerosol sample becomes entrained in the flow medium and the aerosol particles within the aerosol sample are separated by size into a plurality of aerosol flow streams under the influence of the electric field. The camera is disposed adjacent the housing outlet for optically detecting a relative position of at least one aerosol flow stream exiting the outlet and for optically detecting the number of aerosol particles within the at least one aerosol flow stream.

  7. Understanding the Mechanisms Enabling an Ultra-high Efficiency Moving Wire Interface for Real-time Carbon 14 Accelerator Mass Spectrometry Quantitation of Samples Suspended in Solvent

    NASA Astrophysics Data System (ADS)

    Thomas, Avraham Thaler

    Carbon 14 (14C) quantitation by accelerator mass spectrometry (AMS) is a powerfully sensitive and uniquely quantitative tool for tracking labeled carbonaceous molecules in biological systems. This is due to 14C's low natural abundance of 1 ppt, the nominal difference in biological activity between an unlabeled and a 14C-labeled molecule, and the ability of AMS to measure isotopic ratios independently of a sample's other characteristics. To make AMS more broadly accessible, a moving wire interface for real-time coupling of high pressure liquid chromatography (HPLC) to AMS and high throughput AMS quantitation of minute single samples has been developed. Prior to this work, samples needed to be converted to solid carbon before measurement. This conversion process has many steps and requires that the sample size be large enough to allow precise handling of the resulting graphite. These factors make the process susceptible to error and time consuming, as well as requiring 0.5 ug of carbon. Samples which do not contain enough carbon, such as HPLC fractions, must be bulked up. This adds background and increases effort. The moving wire interface overcomes these limitations by automating sample processing. Samples placed on the wire are transported through a solvent removal stage followed by a combustion stage after which the combustion products are directed to a gas accepting ion source. The ion source converts the carbon from the CO2 combustion product into C ions, from which an isotopic ratio can be determined by AMS. Although moving wire interfaces have been implemented for various tasks since 1964, the efficiency of these systems at transferring fluid from an HPLC to the wire was only 3%, the efficiency of transferring combustion products from the combustion oven to ion source was only 30%, the flow and composition of the carrier gas from the combustion oven to the ion source needed to be optimized for coupling to an AMS gas accepting ion source and the drying ovens

  8. Calculation of Transactinide Homolog Isotope Production Reactions Possible with the Center for Accelerator Mass Spectrometry (CAMS) at Lawrence Livermore National Laboratory

    SciTech Connect

    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

  9. Activation of TrkB with TAM-163 results in opposite effects on body weight in rodents and non-human primates.

    PubMed

    Perreault, Mylène; Feng, Guo; Will, Sarah; Gareski, Tiffany; Kubasiak, David; Marquette, Kimberly; Vugmeyster, Yulia; Unger, Thaddeus J; Jones, Juli; Qadri, Ariful; Hahm, Seung; Sun, Ying; Rohde, Cynthia M; Zwijnenberg, Raphael; Paulsen, Janet; Gimeno, Ruth E

    2013-01-01

    Strong genetic data link the Tyrosine kinase receptor B (TrkB) and its major endogenous ligand brain-derived neurotrophic factor (BDNF) to the regulation of energy homeostasis, with loss-of-function mutations in either gene causing severe obesity in both mice and humans. It has previously been reported that peripheral administration of the endogenous TrkB agonist ligand neurotrophin-4 (NT-4) profoundly decreases food intake and body weight in rodents, while paradoxically increasing these same parameters in monkeys. We generated a humanized TrkB agonist antibody, TAM-163, and characterized its therapeutic potential in several models of type 2 diabetes and obesity. In vitro, TAM-163 bound to human and rodent TrkB with high affinity, activated all aspects of the TrkB signaling cascade and induced TrkB internalization and degradation in a manner similar to BDNF. In vivo, peripheral administration of TAM-163 decreased food intake and/or body weight in mice, rats, hamsters, and dogs, but increased food intake and body weight in monkeys. The magnitude of weight change was similar in rodents and non-human primates, occurred at doses where there was no appreciable penetration into deep structures of the brain, and could not be explained by differences in exposures between species. Rather, peripherally administered TAM-163 localized to areas in the hypothalamus and the brain stem located outside the blood-brain barrier in a similar manner between rodents and non-human primates, suggesting differences in neuroanatomy across species. Our data demonstrate that a TrkB agonist antibody, administered peripherally, causes species-dependent effects on body weight similar to the endogenous TrkB ligand NT-4. The possible clinical utility of TrkB agonism in treating weight regulatory disorder, such as obesity or cachexia, will require evaluation in man. PMID:23700410

  10. Method for calibrating mass spectrometers

    DOEpatents

    Anderson, Gordon A [Benton City, WA; Brands, Michael D [Richland, WA; Bruce, James E [Schwenksville, PA; Pasa-Tolic, Ljiljana [Richland, WA; Smith, Richard D [Richland, WA

    2002-12-24

    A method whereby a mass spectra generated by a mass spectrometer is calibrated by shifting the parameters used by the spectrometer to assign masses to the spectra in a manner which reconciles the signal of ions within the spectra having equal mass but differing charge states, or by reconciling ions having known differences in mass to relative values consistent with those known differences. In this manner, the mass spectrometer is calibrated without the need for standards while allowing the generation of a highly accurate mass spectra by the instrument.

  11. Multiple order common path spectrometer

    NASA Technical Reports Server (NTRS)

    Newbury, Amy B. (Inventor)

    2010-01-01

    The present invention relates to a dispersive spectrometer. The spectrometer allows detection of multiple orders of light on a single focal plane array by splitting the orders spatially using a dichroic assembly. A conventional dispersion mechanism such as a defraction grating disperses the light spectrally. As a result, multiple wavelength orders can be imaged on a single focal plane array of limited spectral extent, doubling (or more) the number of spectral channels as compared to a conventional spectrometer. In addition, this is achieved in a common path device.

  12. Gamma ray spectrometer for ITER

    SciTech Connect

    Gin, D.; Chugunov, I.; Shevelev, A.; Khilkevitch, E.; Doinikov, D.; Naidenov, V.; Pasternak, A.; Polunovsky, I.; Kiptily, V.

    2014-08-21

    Gamma diagnostics is considered to be primary for the confined α-particles and runaway electrons measurements on ITER. The gamma spectrometer will be embedded into a neutron dump of the ITER Neutral Particle Analyzer diagnostic complex. It will supplement NPA measurements on the fuel isotope ratio and confined alphas/fast ions. In this paper an update on ITER gamma spectrometer developments is given. A new geometry of the system is described and detailed analysis of expected signals for the spectrometer is presented.

  13. Somatostatin Derivate (smsDX) Attenuates the TAM-Stimulated Proliferation, Migration and Invasion of Prostate Cancer via NF-κB Regulation

    PubMed Central

    Guo, Zhaoxin; Xing, Zhaoquan; Cheng, Xiangyu; Fang, Zhiqing; Jiang, Chao; Su, Jing; Zhou, Zunlin; Xu, Zhonghua; Holmberg, Anders; Nilsson, Sten; Liu, Zhaoxu

    2015-01-01

    Tumor development and progression are influenced by macrophages of the surrounding microenvironment. To investigate the influences of an inflammatory tumor microenvironment on the growth and metastasis of prostate cancer, the present study used a co-culture model of prostate cancer (PCa) cells with tumor-associated macrophage (TAM)-conditioned medium (MCM). MCM promoted PCa cell (LNCaP, DU145 and PC-3) growth, and a xenograft model in nude mice consistently demonstrated that MCM could promote tumor growth. MCM also stimulated migration and invasion in vitro. Somatostatin derivate (smsDX) significantly attenuated the TAM-stimulated proliferation, migration and invasion of prostate cancer. Immunohistochemistry revealed that NF-κB was over-expressed in PCa and BPH with chronic inflammatory tissue specimens and was positively correlated with macrophage infiltration. Further investigation into the underlying mechanism revealed that NF-κB played an important role in macrophage infiltration. SmsDX inhibited the paracrine loop between TAM and PCa cells and may represent a potential therapeutic agent for PCa. PMID:26010447

  14. Coastal Research Imaging Spectrometer

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Coastal Research Imaging Spectrometer (CRIS) is an airborne remote-sensing system designed specifically for research on the physical, chemical, and biological characteristics of coastal waters. The CRIS includes a visible-light hyperspectral imaging subsystem for measuring the color of water, which contains information on the biota, sediment, and nutrient contents of the water. The CRIS also includes an infrared imaging subsystem, which provides information on the temperature of the water. The combination of measurements enables investigation of biological effects of both natural and artificial flows of water from land into the ocean, including diffuse and point-source flows that may contain biological and/or chemical pollutants. Temperature is an important element of such measurements because temperature contrasts can often be used to distinguish among flows from different sources: for example, a sewage outflow could manifest itself in spectral images as a local high-temperature anomaly.anomaly. Both the visible and infrared subsystems scan in "pushbroom" mode: that is, an aircraft carrying the system moves along a ground track, the system is aimed downward, and image data are acquired in acrosstrack linear arrays of pixels. Both subsystems operate at a frame rate of 30 Hz. The infrared and visible-light optics are adjusted so that both subsystems are aimed at the same moving swath, which has across-track angular width of 15. Data from the infrared and visible imaging subsystems are stored in the same file along with aircraft-position data acquired by a Global Positioning System receiver. The combination of the three sets of data is used to construct infrared and hyperspectral maps of scanned areas shown.

  15. Alpha Magnetic Spectrometer (AMS) Overview

    NASA Video Gallery

    The Alpha Magnetic Spectrometer (AMS) is flying to the station on STS-134. The AMS experiment is a state-of-the-art particle physics detector being operated by an international team composed of 60 ...

  16. The GRAVITY spectrometers: optical qualification

    NASA Astrophysics Data System (ADS)

    Yazici, Senol; Straubmeier, Christian; Wiest, Michael; Wank, Imke; Fischer, Sebastian; Horrobin, Matthew; Eisenhauer, Frank; Perrin, Guy; Perraut, Karine; Brandner, Wolfgang; Amorim, Antonio; Schöller, Markus; Eckart, Andreas

    2014-07-01

    GRAVITY1 is a 2nd generation Very Large Telescope Interferometer (VLTI) operated in the astronomical K-band. In the Beam Combiner Instrument2 (BCI) four Fiber Couplers3 (FC) will feed the light coming from each telescope into two fibers, a reference channel for the fringe tracking spectrometer4 (FT) and a science channel for the science spectrometer4 (SC). The differential Optical Path Difference (dOPD) between the two channels will be corrected using a novel metrology concept.5 The metrology laser will keep control of the dOPD of the two channels. It is injected into the spectrometers and detected at the telescope level. Piezo-actuated fiber stretchers correct the dOPD accordingly. Fiber-fed Integrated Optics6 (IO) combine coherently the light of all six baselines and feed both spectrometers. Assisted by Infrared Wavefront Sensors7 (IWS) at each Unit Telescope (UT) and correcting the path difference between the channels with an accuracy of up to 5 nm, GRAVITY will push the limits of astrometrical accuracy to the order of 10 μas and provide phase-referenced interferometric imaging with a resolution of 4 mas. The University of Cologne developed, constructed and tested both spectrometers of the camera system. Both units are designed for the near infrared (1.95 - 2.45 μm) and are operated in a cryogenic environment. The Fringe Tracker is optimized for highest transmission with fixed spectral resolution (R = 22) realized by a double-prism.8 The Science spectrometer is more diverse and allows to choose from three different spectral resolutions8 (R = [22, 500, 4000]), where the lowest resolution is achieved with a prism and the higher resolutions are realized with grisms. A Wollaston prism in each spectrometer allows for polarimetric splitting of the light. The goal for the spectrometers is to concentrate at least 90% of the ux in 2 × 2 pixel (36 × 36 μm2) for the Science channel and in 1 pixel (24 × 24 μm) in the Fringe Tracking channel. In Section 1, we present

  17. Coastal Research Imaging Spectrometer

    NASA Technical Reports Server (NTRS)

    Lucey, Paul G.; Williams, Timothy; Horton, Keith A.

    2004-01-01

    The Coastal Research Imaging Spectrometer (CRIS) is an airborne remote sensing system designed specifically for research on the physical, chemical, and biological characteristics of coastal waters. The CRIS includes a visible-light hyperspectral imaging subsystem for measuring the color of water, which contains information on the biota, sediment, and nutrient contents of the water. The CRIS also includes an infrared imaging subsystem, which provides information on the temperature of the water. The combination of measurements enables investigation of biological effects of both natural and artificial flows of water from land into the ocean, including diffuse and point-source flows that may contain biological and/or chemical pollutants. Temperature is an important element of such measurements because temperature contrasts can often be used to distinguish among flows from different sources: for example, a sewage outflow could manifest itself in spectral images as a local high-temperature anomaly. Both the visible and infrared subsystems scan in pushbroom mode: that is, an aircraft carrying the system moves along a ground track, the system is aimed downward, and image data are acquired in across-track linear arrays of pixels. Both subsystems operate at a frame rate of 30 Hz. The infrared and visible-light optics are adjusted so that both subsystems are aimed at the same moving swath, which has across-track angular width of 15 . Data from the infrared and visible imaging subsystems are stored in the same file along with aircraft- position data acquired by a Global Positioning System receiver. The combination of the three sets of data is used to construct infrared and hyperspectral maps of scanned areas (see figure). The visible subsystem is based on a grating spectrograph and a rapid-readout charge-coupled-device camera. Images of the swatch are acquired in 256 spectral bands at wavelengths from 400 to 800 nm. The infrared subsystem, which is sensitive in a single

  18. Hydrologic and geochemical controls on the transport of radionuclides in natural undisturbed arid environments as determined by accelerator mass spectrometry measurements

    SciTech Connect

    Nimz, G; Caffee, M W; McAninch, J

    2000-04-01

    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 {sup 129}I (fallout concentration: {approx} 10{sup 6} atoms/g) {sup 99}Tc ({approx} 10{sup 9} atoms/g), {sup 90}Sr ({approx}10{sup 7} atoms/gram soil), and {sup 93}Zr ({approx} 10{sup 9} atoms/g), and improved methods for {sup 36}Cl ({approx} 10{sup 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 {sup 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) {sup 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 {sup 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) {sup 99}Tc is readily measurable by AMS, as we demonstrate by the first AMS {sup 99}Tc measurements of

  19. Resolution-enhanced Mapping Spectrometer

    NASA Technical Reports Server (NTRS)

    Kumer, J. B.; Aubrun, J. N.; Rosenberg, W. J.; Roche, A. E.

    1993-01-01

    A familiar mapping spectrometer implementation utilizes two dimensional detector arrays with spectral dispersion along one direction and spatial along the other. Spectral images are formed by spatially scanning across the scene (i.e., push-broom scanning). For imaging grating and prism spectrometers, the slit is perpendicular to the spatial scan direction. For spectrometers utilizing linearly variable focal-plane-mounted filters the spatial scan direction is perpendicular to the direction of spectral variation. These spectrometers share the common limitation that the number of spectral resolution elements is given by the number of pixels along the spectral (or dispersive) direction. Resolution enhancement by first passing the light input to the spectrometer through a scanned etalon or Michelson is discussed. Thus, while a detector element is scanned through a spatial resolution element of the scene, it is also temporally sampled. The analysis for all the pixels in the dispersive direction is addressed. Several specific examples are discussed. The alternate use of a Michelson for the same enhancement purpose is also discussed. Suitable for weight constrained deep space missions, hardware systems were developed including actuators, sensor, and electronics such that low-resolution etalons with performance required for implementation would weigh less than one pound.

  20. Ultra Compact Imaging Spectrometer (UCIS)

    NASA Astrophysics Data System (ADS)

    Blaney, Diana L.; Green, Robert; Mouroulis, Pantazis; Cable, Morgan; Ehlmann, Bethany; Haag, Justin; Lamborn, Andrew; McKinley, Ian; Rodriguez, Jose; van Gorp, Byron

    2016-10-01

    The Ultra Compact Imaging Spectrometer (UCIS) is a modular visible to short wavelength infrared imaging spectrometer architecture which could be adapted to a variety of mission concepts requiring low mass and low power. Imaging spectroscopy is an established technique to address complex questions of geologic evolution by mapping diagnostic absorption features due to minerals, organics, and volatiles throughout our solar system. At the core of UCIS is an Offner imaging spectrometer using M3 heritage and a miniature pulse tube cryo-cooler developed under the NASA Maturation of Instruments for Solar System Exploration (MatISSE) program to cool the focal plane array. The TRL 6 integrated spectrometer and cryo-cooler provide a basic imaging spectrometer capability that is used with a variety of fore optics to address lunar, mars, and small body science goals. Potential configurations include: remote sensing from small orbiters and flyby spacecraft; in situ panoramic imaging spectroscopy; and in situ micro-spectroscopy. A micro-spectroscopy front end is being developed using MatISSE funding with integration and testing planned this summer.

  1. Mini ion trap mass spectrometer

    DOEpatents

    Dietrich, D.D.; Keville, R.F.

    1995-09-19

    An ion trap is described which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10{sup 9} and commercial mass spectrometers requiring 10{sup 4} ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products. 10 figs.

  2. Mini ion trap mass spectrometer

    DOEpatents

    Dietrich, Daniel D.; Keville, Robert F.

    1995-01-01

    An ion trap which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10.sup.9 and commercial mass spectrometers requiring 10.sup.4 ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products.

  3. Multichannel Spectrometer of Time Distribution

    NASA Astrophysics Data System (ADS)

    Akindinova, E. V.; Babenko, A. G.; Vakhtel, V. M.; Evseev, N. A.; Rabotkin, V. A.; Kharitonova, D. D.

    2015-06-01

    For research and control of characteristics of radiation fluxes, radioactive sources in particular, for example, in paper [1], a spectrometer and methods of data measurement and processing based on the multichannel counter of time intervals of accident events appearance (impulses of particle detector) MC-2A (SPC "ASPECT") were created. The spectrometer has four independent channels of registration of time intervals of impulses appearance and correspondent amplitude and spectrometric channels for control along the energy spectra of the operation stationarity of paths of each of the channels from the detector to the amplifier. The registration of alpha-radiation is carried out by the semiconductor detectors with energy resolution of 16-30 keV. Using a spectrometer there have been taken measurements of oscillations of alpha-radiation 239-Pu flux intensity with a subsequent autocorrelative statistical analysis of the time series of readings.

  4. A cometary ion mass spectrometer

    NASA Technical Reports Server (NTRS)

    Shelley, E. G.; Simpson, D. A.

    1984-01-01

    The development of flight suitable analyzer units for that part of the GIOTTO Ion Mass Spectrometer (IMS) experiment designated the High Energy Range Spectrometer (HERS) is discussed. Topics covered include: design of the total ion-optical system for the HERS analyzer; the preparation of the design of analyzing magnet; the evaluation of microchannel plate detectors and associated two-dimensional anode arrays; and the fabrication and evaluation of two flight-suitable units of the complete ion-optical analyzer system including two-dimensional imaging detectors and associated image encoding electronics.

  5. Towed seabed gamma ray spectrometer

    SciTech Connect

    Jones, D.G. )

    1994-08-01

    For more than 50 years, the measurement of radioactivity has been used for onshore geological surveys and in laboratories. The British Geological Survey (BGS) has extended the use of this type of equipment to the marine environment with the development of seabed gamma ray spectrometer systems. The present seabed gamma ray spectrometer, known as the Eel, has been successfully used for sediment and solid rock mapping, mineral exploration, and radioactive pollution studies. The range of applications for the system continues to expand. This paper examines the technological aspects of the Eel and some of the applications for which it has been used.

  6. JPL Fourier transform ultraviolet spectrometer

    NASA Technical Reports Server (NTRS)

    Cageao, R. P.; Friedl, R. R.; Sander, Stanley P.; Yung, Y. L.

    1994-01-01

    The Fourier Transform Ultraviolet Spectrometer (FTUVS) is a new high resolution interferometric spectrometer for multiple-species detection in the UV, visible and near-IR. As an OH sensor, measurements can be carried out by remote sensing (limb emission and column absorption), or in-situ sensing (long-path absorption or laser-induced fluorescence). As a high resolution detector in a high repetition rate (greater than 10 kHz) LIF system, OH fluorescence can be discriminated against non-resonant background emission and laser scatter, permitting (0, 0) excitation.

  7. Portable smartphone optical fibre spectrometer

    NASA Astrophysics Data System (ADS)

    Hossain, Md. Arafat; Canning, John; Cook, Kevin; Jamalipour, Abbas

    2015-09-01

    A low cost, optical fibre based spectrometer has been developed on a smartphone platform for field-portable spectral analysis. Light of visible wavelength is collected using a multimode optical fibre and diffracted by a low cost nanoimprinted diffraction grating. A measurement range over 300 nm span (λ = 400 to 700 nm) is obtained using the smartphone CMOS chip. The spectral resolution is Δλ ~ 0.42 nm/screen pixel. A customized Android application processed the spectra on the same platform and shares with other devices. The results compare well with commercially available spectrometer.

  8. A high-throughput neutron spectrometer

    NASA Astrophysics Data System (ADS)

    Stampfl, Anton; Noakes, Terry; Bartsch, Friedl; Bertinshaw, Joel; Veliscek-Carolan, Jessica; Nateghi, Ebrahim; Raeside, Tyler; Yethiraj, Mohana; Danilkin, Sergey; Kearley, Gordon

    2010-03-01

    A cross-disciplinary high-throughput neutron spectrometer is currently under construction at OPAL, ANSTO's open pool light-water research reactor. The spectrometer is based on the design of a Be-filter spectrometer (FANS) that is operating at the National Institute of Standards research reactor in the USA. The ANSTO filter-spectrometer will be switched in and out with another neutron spectrometer, the triple-axis spectrometer, Taipan. Thus two distinct types of neutron spectrometers will be accessible: one specialised to perform phonon dispersion analysis and the other, the filter-spectrometer, designed specifically to measure vibrational density of states. A summary of the design will be given along with a detailed ray-tracing analysis. Some preliminary results will be presented from the spectrometer.

  9. MICE Spectrometer Magnet System Progress

    SciTech Connect

    Green, Michael A.; Virostek, Steve P.

    2007-08-27

    The first magnets for the muon ionization cooling experimentwill be the tracker solenoids that form the ends of the MICE coolingchannel. The primary purpose of the tracker solenoids is to provide auniform 4 T field (to better than +-0.3 percent over a volume that is 1meter long and 0.3 meters in diameter) spectrometer magnet field for thescintillating fiber detectors that are used to analyze the muons in thechannel before and after ionization cooling. A secondary purpose for thetracker magnet is the matching of the muon beam between the rest of theMICE cooling channel and the uniform field spectrometer magnet. Thetracker solenoid is powered by three 300 amp power supplies. Additionaltuning of the spectrometer is provided by a pair of 50 amp power suppliesacross the spectrometer magnet end coils. The tracker magnet will becooled using a pair of 4 K pulse tube coolers that each provide 1.5 W ofcooling at 4.2 K. Final design and construction of the tracker solenoidsbegan during the summer of 2006. This report describes the progress madeon the construction of the tracker solenoids.

  10. Convex Diffraction Grating Imaging Spectrometer

    NASA Technical Reports Server (NTRS)

    Chrisp, Michael P. (Inventor)

    1999-01-01

    A 1:1 Offner mirror system for imaging off-axis objects is modified by replacing a concave spherical primary mirror that is concentric with a convex secondary mirror with two concave spherical mirrors M1 and M2 of the same or different radii positioned with their respective distances d1 and d2 from a concentric convex spherical diffraction grating having its grooves parallel to the entrance slit of the spectrometer which replaces the convex secondary mirror. By adjusting their distances d1 and d2 and their respective angles of reflection alpha and beta, defined as the respective angles between their incident and reflected rays, all aberrations are corrected without the need to increase the spectrometer size for a given entrance slit size to reduce astigmatism, thus allowing the imaging spectrometer volume to be less for a given application than would be possible with conventional imaging spectrometers and still give excellent spatial and spectral imaging of the slit image spectra over the focal plane.

  11. Acoustically-tuned optical spectrometer

    NASA Technical Reports Server (NTRS)

    Sklar, E.

    1981-01-01

    Lens arrangement corrects for aberrations and gives resolution of 0.7 seconds of arc. In spectrometer, light from telescope is relayed by doublet lens to acoustically tuned optical filter. Selected wavelengths are relayed by triplet lens to charge coupled device camera. Intervening cylindrical lens, tilted at 12 degree angle, corrects for astigmatism and coma introduced by two element birefringent crystal in filter.

  12. IPNS-I chopper spectrometers

    SciTech Connect

    Price, D.L.; Carpenter, J.M.; Pelizzari, C.A.; Sinha, S.K.; Bresof, I.; Ostrowski, G.E.

    1982-01-01

    We briefly describe the layout and operation of the two chopper experiments at IPNS-I. The recent measurement on solid /sup 4/He by Hilleke et al. provides examples of time-of-flight data from the Low Resolution Chopper Spectrometer.

  13. Time of flight mass spectrometer

    DOEpatents

    Ulbricht, Jr., William H.

    1984-01-01

    A time-of-flight mass spectrometer is described in which ions are desorbed from a sample by nuclear fission fragments, such that desorption occurs at the surface of the sample impinged upon by the fission fragments. This configuration allows for the sample to be of any thickness, and eliminates the need for complicated sample preparation.

  14. Mid infrared MEMS FTIR spectrometer

    NASA Astrophysics Data System (ADS)

    Erfan, Mazen; Sabry, Yasser M.; Mortada, Bassem; Sharaf, Khaled; Khalil, Diaa

    2016-03-01

    In this work we report, for the first time to the best of our knowledge, a bulk-micromachined wideband MEMS-based spectrometer covering both the NIR and the MIR ranges and working from 1200 nm to 4800 nm. The core engine of the spectrometer is a scanning Michelson interferometer micro-fabricated using deep reactive ion etching (DRIE) technology. The spectrum is obtained using the Fourier Transform techniques that allows covering a very wide spectral range limited by the detector responsivity. The moving mirror of the interferometer is driven by a relatively large stroke electrostatic comb-drive actuator. Zirconium fluoride (ZrF4) multimode optical fibers are used to connect light between the white light source and the interferometer input, as well as the interferometer output to a PbSe photoconductive detector. The recorded signal-to-noise ratio is 25 dB at the wavelength of 3350 nm. The spectrometer is successfully used in measuring the absorption spectra of methylene chloride, quartz glass and polystyrene film. The presented solution provides a low cost method for producing miniaturized spectrometers in the near-/mid-infrared.

  15. Alpha proton x ray spectrometer

    NASA Technical Reports Server (NTRS)

    Rieder, Rudi; Waeke, H.; Economou, T.

    1994-01-01

    Mars Pathfinder will carry an alpha-proton x ray spectrometer (APX) for the determination of the elemental chemical composition of Martian rocks and soils. The instrument will measure the concentration of all major and some minor elements, including C, N, and O at levels above typically 1 percent.

  16. Berberine enhances the anti‑tumor activity of tamoxifen in drug‑sensitive MCF‑7 and drug‑resistant MCF‑7/TAM cells.

    PubMed

    Wen, Chunjie; Wu, Lanxiang; Fu, Lijuan; Zhang, Xue; Zhou, Honghao

    2016-09-01

    Berberine, an isoquinoline alkaloid, has been previously demonstrated to possess anti‑breast cancer properties. Tamoxifen is widely used in the prevention and treatment of estrogen receptor-positive breast cancer. Thus, the aim of the present study was to assess whether berberine enhanced the anticancer effect of tamoxifen, and the underlying mechanism involved in this combined effect in tamoxifen-sensitive (MCF-7) and tamoxifen-resistant (MCF-7/TAM) cells using MTS, flow cytometry and western blot assays. The results indicated that berberine demonstrated dose‑ and time‑dependent anti‑proliferative activity in MCF‑7 and MCF‑7/TAM cells. Furthermore, the combination of berberine and tamoxifen induced cell growth inhibition more effectively than tamoxifen alone. The present study also demonstrated that combinational treatment is more effective in inducing G1 phase arrest and activating apoptosis compared tamoxifen alone, which may be due to upregulation of P21 expression and downregulation of the B‑cell CLL/lymphoma 2(Bcl‑2)/Bcl‑2 associated X protein ratio. The results of the present study suggested that berberine may potentially be useful as an adjuvant agent in cancer chemotherapy to enhance the effect of tamoxifen, which will be useful for anti‑tumor therapy and further research.

  17. Berberine enhances the anti‑tumor activity of tamoxifen in drug‑sensitive MCF‑7 and drug‑resistant MCF‑7/TAM cells.

    PubMed

    Wen, Chunjie; Wu, Lanxiang; Fu, Lijuan; Zhang, Xue; Zhou, Honghao

    2016-09-01

    Berberine, an isoquinoline alkaloid, has been previously demonstrated to possess anti‑breast cancer properties. Tamoxifen is widely used in the prevention and treatment of estrogen receptor-positive breast cancer. Thus, the aim of the present study was to assess whether berberine enhanced the anticancer effect of tamoxifen, and the underlying mechanism involved in this combined effect in tamoxifen-sensitive (MCF-7) and tamoxifen-resistant (MCF-7/TAM) cells using MTS, flow cytometry and western blot assays. The results indicated that berberine demonstrated dose‑ and time‑dependent anti‑proliferative activity in MCF‑7 and MCF‑7/TAM cells. Furthermore, the combination of berberine and tamoxifen induced cell growth inhibition more effectively than tamoxifen alone. The present study also demonstrated that combinational treatment is more effective in inducing G1 phase arrest and activating apoptosis compared tamoxifen alone, which may be due to upregulation of P21 expression and downregulation of the B‑cell CLL/lymphoma 2(Bcl‑2)/Bcl‑2 associated X protein ratio. The results of the present study suggested that berberine may potentially be useful as an adjuvant agent in cancer chemotherapy to enhance the effect of tamoxifen, which will be useful for anti‑tumor therapy and further research. PMID:27432642

  18. Electron/proton spectrometer certification documentation analyses

    NASA Technical Reports Server (NTRS)

    Gleeson, P.

    1972-01-01

    A compilation of analyses generated during the development of the electron-proton spectrometer for the Skylab program is presented. The data documents the analyses required by the electron-proton spectrometer verification plan. The verification plan was generated to satisfy the ancillary hardware requirements of the Apollo Applications program. The certification of the spectrometer requires that various tests, inspections, and analyses be documented, approved, and accepted by reliability and quality control personnel of the spectrometer development program.

  19. Sample rotating turntable kit for infrared spectrometers

    DOEpatents

    Eckels, Joel Del; Klunder, Gregory L.

    2008-03-04

    An infrared spectrometer sample rotating turntable kit has a rotatable sample cup containing the sample. The infrared spectrometer has an infrared spectrometer probe for analyzing the sample and the rotatable sample cup is adapted to receive the infrared spectrometer probe. A reflectance standard is located in the rotatable sample cup. A sleeve is positioned proximate the sample cup and adapted to receive the probe. A rotator rotates the rotatable sample cup. A battery is connected to the rotator.

  20. Aerosol propellant interference with clinical mass spectrometers.

    PubMed

    Kharasch, E D; Sivarajan, M

    1991-04-01

    Metered dose inhalers containing halogenated propellants may interfere with mass spectrometer quantitation of halogenated inhalation anesthetics. We identify the propellant(s) in a commercially available metered dose inhaler that caused erroneous mass spectrometer readings. In addition, we identify the causes of different types of interference in different mass spectrometers. PMID:2072131

  1. Electron spectrometer for gas-phase spectroscopy

    SciTech Connect

    Bozek, J.D.; Schlachter, A.S.

    1997-04-01

    An electron spectrometer for high-resolution spectroscopy of gaseous samples using synchrotron radiation has been designed and constructed. The spectrometer consists of a gas cell, cylindrical electrostatic lens, spherical-sector electron energy analyzer, position-sensitive detector and associated power supplies, electronics and vacuum pumps. Details of the spectrometer design are presented together with some representative spectra.

  2. Recombinant expression, purification, crystallization and preliminary X-ray diffraction analysis of the C-terminal DUF490(963-1138) domain of TamB from Escherichia coli.

    PubMed

    Josts, Inokentijs; Grinter, Rhys; Kelly, Sharon M; Mosbahi, Khedidja; Roszak, Aleksander; Cogdell, Richard; Smith, Brian O; Byron, Olwyn; Walker, Daniel

    2014-09-01

    TamB is a recently described inner membrane protein that, together with its partner protein TamA, is required for the efficient secretion of a subset of autotransporter proteins in Gram-negative bacteria. In this study, the C-terminal DUF490963-1138 domain of TamB was overexpressed in Escherichia coli K-12, purified and crystallized using the sitting-drop vapour-diffusion method. The crystals belonged to the primitive trigonal space group P3121, with unit-cell parameters a = b = 57.34, c = 220.74 Å, and diffracted to 2.1 Å resolution. Preliminary secondary-structure and X-ray diffraction analyses are reported. Two molecules are predicted to be present in the asymmetric unit. Experimental phasing using selenomethionine-labelled protein will be undertaken in the future.

  3. Imaging X-ray spectrometer

    NASA Technical Reports Server (NTRS)

    Grant, P. A.; Jackson, J. W., Jr.; Alcorn, G. E.; Marshall, F. E. (Inventor)

    1984-01-01

    An X-ray spectrometer for providing imaging and energy resolution of an X-ray source is described. This spectrometer is comprised of a thick silicon wafer having an embedded matrix or grid of aluminum completely through the wafer fabricated, for example, by thermal migration. The aluminum matrix defines the walls of a rectangular array of silicon X-ray detector cells or pixels. A thermally diffused aluminum electrode is also formed centrally through each of the silicon cells with biasing means being connected to the aluminum cell walls and causes lateral charge carrier depletion between the cell walls so that incident X-ray energy causes a photoelectric reaction within the silicon producing collectible charge carriers in the form of electrons which are collected and used for imaging.

  4. Exploiting a Transmission Grating Spectrometer

    SciTech Connect

    Ronald E. Bell

    2004-12-08

    The availability of compact transmission grating spectrometers now allows an attractive and economical alternative to the more familiar Czerny-Turner configuration for many high-temperature plasma applications. Higher throughput is obtained with short focal length refractive optics and stigmatic imaging. Many more spectra can be obtained with a single spectrometer since smaller, more densely packed optical input fibers can be used. Multiple input slits, along with a bandpass filter, can be used to maximize the number of spectra per detector, providing further economy. Curved slits can correct for the strong image curvature of the short focal length optics. Presented here are the governing grating equations for both standard and high-dispersion transmission gratings, defining dispersion, image curvature, and desired slit curvature, that can be used in the design of improved plasma diagnostics.

  5. Concerning the Spatial Heterodyne Spectrometer

    DOE PAGES

    Lenzner, Matthias; Diels, Jean -Claude

    2016-01-22

    A modified Spatial Heterodyne Spectrometer (SHS) is used for measuring atomic emission spectra with high resolution. This device is basically a Fourier Transform Spectrometer, but the Fourier transform is taken in the directions perpendicular to the optical propagation and heterodyned around one preset wavelength. In recent descriptions of this device, one specific phenomenon - the tilt of the energy front of wave packets when diffracted from a grating - was neglected. This led to an overestimate of the resolving power of this spectrograph, especially in situations when the coherence length of the radiation under test is in the order ofmore » the effective aperture of the device. In conclusion, the limits of usability are shown here together with some measurements of known spectral lines.« less

  6. A simple ice nucleation spectrometer.

    PubMed

    Wharton, David A; Mutch, Jodi S; Wilson, Peter W; Marshall, Craig J; Lim, Miang

    2004-01-01

    The construction of a simple ice nucleation spectrometer is described. It uses 10 microliter droplets loaded into glass capillary tubes which are then inserted into an aluminium holder. Each holder takes six capillary tubes surrounding a central thermocouple. Four holders are placed into a cooling block, cooled by fluid from a programmable refrigerated circulator, and the thermocouples interfaced to a computer to record temperatures. Freezing of each sample is detected by an exotherm on the temperature recording, with 24 samples recorded per run. The spectrometer was tested using deionized water, an extract from a New Zealand alpine cockroach and an extract of lawn grass. The cockroach extract is estimated to contain about 10(3) more nucleators, active at -5 degrees C, than the grass extract. PMID:15618985

  7. Holographic Fabry-Perot spectrometer.

    PubMed

    Martínez-Matos, O; Rodrigo, José A; Vaveliuk, P; Calvo, M L

    2011-02-15

    We propose a spectrum analyzer based on the properties of a hologram recorded with the field transmitted by a Fabry-Perot etalon. The spectral response of this holographic Fabry-Perot spectrometer (HFPS) is analytically investigated in the paraxial approximation and compared with a conventional Fabry-Perot etalon of similar characteristics. We demonstrate that the resolving power is twice increased and the free spectral range (FSR) is reduced to one-half. The proposed spectrometer could improve the operational performance of the etalon because it can exhibit high efficiency and it would be insensible to environmental conditions such as temperature and vibrations. Our analysis also extends to another variant of the HFPS based on holographic multiplexing of the transmitted field of a Fabry-Perot etalon. This device increases the FSR, keeping the same HFPS performance.

  8. On-chip plasmonic spectrometer.

    PubMed

    Tsur, Yuval; Arie, Ady

    2016-08-01

    We report a numerical and experimental study of an on-chip optical spectrometer, utilizing propagating surface plasmon polaritons in the telecom spectral range. The device is based on two holographic gratings, one for coupling, and the other for decoupling free-space radiation with the surface plasmons. This 800 μm×100 μm on-chip spectrometer resolves 17 channels spectrally separated by 3.1 nm, spanning a freely tunable spectral window, and is based on standard lithography fabrication technology. We propose two potential applications for this new device; the first employs the holographic control over the amplitude and phase of the input spectrum, for intrinsically filtering unwanted frequencies, like pump radiation in Raman spectroscopy. The second prospect utilizes the unique plasmonic field enhancement at the metal-dielectric boundary for the spectral analysis of very small samples (e.g., Mie scatterers) placed between the two gratings.

  9. On-chip plasmonic spectrometer.

    PubMed

    Tsur, Yuval; Arie, Ady

    2016-08-01

    We report a numerical and experimental study of an on-chip optical spectrometer, utilizing propagating surface plasmon polaritons in the telecom spectral range. The device is based on two holographic gratings, one for coupling, and the other for decoupling free-space radiation with the surface plasmons. This 800 μm×100 μm on-chip spectrometer resolves 17 channels spectrally separated by 3.1 nm, spanning a freely tunable spectral window, and is based on standard lithography fabrication technology. We propose two potential applications for this new device; the first employs the holographic control over the amplitude and phase of the input spectrum, for intrinsically filtering unwanted frequencies, like pump radiation in Raman spectroscopy. The second prospect utilizes the unique plasmonic field enhancement at the metal-dielectric boundary for the spectral analysis of very small samples (e.g., Mie scatterers) placed between the two gratings. PMID:27472609

  10. Concerning the Spatial Heterodyne Spectrometer.

    PubMed

    Lenzner, Matthias; Diels, Jean-Claude

    2016-01-25

    A modified Spatial Heterodyne Spectrometer (SHS) is used for measuring atomic emission spectra with high resolution. This device is basically a Fourier Transform Spectrometer, but the Fourier transform is taken in the directions perpendicular to the optical propagation and heterodyned around one preset wavelength. In recent descriptions of this device, one specific phenomenon - the tilt of the energy front of wave packets when diffracted from a grating - was neglected. This led to an overestimate of the resolving power of this spectrograph, especially in situations when the coherence length of the radiation under test is in the order of the effective aperture of the device. The limits of usability are shown here together with some measurements of known spectral lines. PMID:26832561

  11. High Resolution Imaging Spectrometer (HIRIS)

    NASA Technical Reports Server (NTRS)

    Conley, Joseph M.; Herring, Mark; Norris, David D.

    1988-01-01

    The High Resolution Imaging Spectrometer (HIRIS), related data system, orbit, and mission operations are described. The pushbroom instrument simultaneously images the terrestrial surface in 192 spectral bands from 0.4 to 2.5 microns. The swath width is 30 km and spatial resolution is 30 m. It is planned to be launched with the Earth Observing System aboard the Space Station Polar Platform in 1995. Array detectors allow concurrent integration of the signals at 192,000 detector elements.

  12. GreenHouse Observations of the Stratosphere and Troposphere (GHOST): a novel shortwave infrared spectrometer developed for the Global Hawk unmanned aerial vehicle

    NASA Astrophysics Data System (ADS)

    Humpage, Neil; Bösch, Hartmut; Palmer, Paul I.; Parr-Burman, Phil M.; Vick, Andrew J. A.; Bezawada, Naidu N.; Black, Martin; Born, Andrew J.; Pearson, David; Strachan, Jonathan; Wells, Martyn

    2014-10-01

    The tropospheric distribution of greenhouse gases (GHGs) depends on surface flux variations, atmospheric chemistry and transport processes over a range of spatial and temporal scales. Accurate and precise atmospheric concentration observations of GHGs can be used to infer surface flux estimates, though their interpretation relies on unbiased atmospheric transport models. GHOST is a novel, compact shortwave infrared spectrometer which will observe tropospheric columns of CO2, CO, CH4 and H2O (along with the HDO/H2O ratio) during deployment on board the NASA Global Hawk unmanned aerial vehicle. The primary science objectives of GHOST are to: 1) test atmospheric transport models; 2) evaluate satellite observations of GHG column observations over oceans; and 3) complement in-situ tropopause transition layer observations from other Global Hawk instruments. GHOST comprises a target acquisition module (TAM), a fibre slicer and feed system, and a multiple order spectrograph. The TAM is programmed to direct solar radiation reflected by the ocean surface into a fibre optic bundle. Incoming light is then split into four spectral bands, selected to optimise remote observations of GHGs. The design uses a single grating and detector for all four spectral bands. We summarise the GHOST concept and its objectives, and describe the instrument design and proposed deployment aboard the Global Hawk platform.

  13. Ion mobility spectrometer / mass spectrometer (IMS-MS).

    SciTech Connect

    Hunka Deborah Elaine; Austin, Daniel E.

    2005-07-01

    The use of Ion Mobility Spectrometry (IMS) in the Detection of Contraband Sandia researchers use ion mobility spectrometers for trace chemical detection and analysis in a variety of projects and applications. Products developed in recent years based on IMS-technology include explosives detection personnel portals, the Material Area Access (MAA) checkpoint of the future, an explosives detection vehicle portal, hand-held detection systems such as the Hound and Hound II (all 6400), micro-IMS sensors (1700), ordnance detection (2500), and Fourier Transform IMS technology (8700). The emphasis to date has been on explosives detection, but the detection of chemical agents has also been pursued (8100 and 6400). Combining Ion Mobility Spectrometry (IMS) with Mass Spectrometry (MS) is described. The IMS-MS combination overcomes several limitations present in simple IMS systems. Ion mobility alone is insufficient to identify an unknown chemical agent. Collision cross section, upon which mobility is based, is not sufficiently unique or predictable a priori to be able to make a confident peak assignment unless the compounds present are already identified. Molecular mass, on the other hand, is much more readily interpreted and related to compounds. For a given compound, the molecular mass can be determined using a pocket calculator (or in one's head) while a reasonable value of the cross-section might require hours of computation time. Thus a mass spectrum provides chemical specificity and identity not accessible in the mobility spectrum alone. In addition, several advanced mass spectrometric methods, such as tandem MS, have been extensively developed for the purpose of molecular identification. With an appropriate mass spectrometer connected to an ion mobility spectrometer, these advanced identification methods become available, providing greater characterization capability.

  14. Ion Mobility Spectrometer / Mass Spectrometer (IMS-MS).

    SciTech Connect

    Hunka, Deborah E; Austin, Daniel

    2005-10-01

    The use of Ion Mobility Spectrometry (IMS)in the Detection of Contraband Sandia researchers use ion mobility spectrometers for trace chemical detection and analysis in a variety of projects and applications. Products developed in recent years based on IMS-technology include explosives detection personnel portals, the Material Area Access (MAA) checkpoint of the future, an explosives detection vehicle portal, hand-held detection systems such as the Hound and Hound II (all 6400), micro-IMS sensors (1700), ordnance detection (2500), and Fourier Transform IMS technology (8700). The emphasis to date has been on explosives detection, but the detection of chemical agents has also been pursued (8100 and 6400).Combining Ion Mobility Spectrometry (IMS) with Mass Spectrometry (MS)The IMS-MS combination overcomes several limitations present in simple IMS systems. Ion mobility alone is insufficient to identify an unknown chemical agent. Collision cross section, upon which mobility is based, is not sufficiently unique or predictable a priori to be able to make a confident peak assignment unless the compounds present are already identified. Molecular mass, on the other hand, is much more readily interpreted and related to compounds. For a given compound, the molecular mass can be determined using a pocket calculator (or in one's head) while a reasonable value of the cross-section might require hours of computation time. Thus a mass spectrum provides chemical specificity and identity not accessible in the mobility spectrum alone. In addition, several advanced mass spectrometric methods, such as tandem MS, have been extensively developed for the purpose of molecular identification. With an appropriate mass spectrometer connected to an ion mobility spectrometer, these advanced identification methods become available, providing greater characterization capability.3 AcronymsIMSion mobility spectrometryMAAMaterial Access AreaMSmass spectrometryoaTOForthogonal acceleration time

  15. The Pickup Ion Composition Spectrometer

    NASA Astrophysics Data System (ADS)

    Gilbert, Jason A.; Zurbuchen, Thomas H.; Battel, Steven

    2016-06-01

    Observations of newly ionized atoms that are picked up by the magnetic field in the expanding solar wind contain crucial information about the gas or dust compositions of their origins. The pickup ions (PUIs) are collected by plasma mass spectrometers and analyzed for their density, composition, and velocity distribution. In addition to measurements of PUIs from planetary sources, in situ measurements of interstellar gas have been made possible by spectrometers capable of differentiating between heavy ions of solar and interstellar origin. While important research has been done on these often singly charged ions, the instruments that have detected many of them were designed for the energy range and ionic charge states of the solar wind and energized particle populations, and not for pickup ions. An instrument optimized for the complete energy and time-of-flight characterization of pickup ions will unlock a wealth of data on these hitherto unobserved or unresolved PUI species. The Pickup Ion Composition Spectrometer (PICSpec) is one such instrument and can enable the next generation of pickup ion and isotopic mass composition measurements. By combining a large-gap time-of-flight-energy sensor with a -100 kV high-voltage power supply for ion acceleration, PUIs will not only be above the detection threshold of traditional solid-state energy detectors but also be resolved sufficiently in time of flight that isotopic composition can be determined. This technology will lead to a new generation of space composition instruments, optimized for measurements of both heliospheric and planetary pickup ions.

  16. Alpha-particle spectrometer experiment

    NASA Technical Reports Server (NTRS)

    Gorenstein, P.; Bjorkholm, P.

    1972-01-01

    Mapping the radon emanation of the moon was studied to find potential areas of high activity by detection of radon isotopes and their daughter products. It was felt that based on observation of regions overflown by Apollo spacecraft and within the field of view of the alpha-particle spectrometer, a radon map could be constructed, identifying and locating lunar areas of outgassing. The basic theory of radon migration from natural concentrations of uranium and thorium is discussed in terms of radon decay and the production of alpha particles. The preliminary analysis of the results indicates no significant alpha emission.

  17. Portable neutron spectrometer and dosimeter

    DOEpatents

    Waechter, David A.; Erkkila, Bruce H.; Vasilik, Dennis G.

    1985-01-01

    The disclosure relates to a battery operated neutron spectrometer/dosimeter utilizing a microprocessor, a built-in tissue equivalent LET neutron detector, and a 128-channel pulse height analyzer with integral liquid crystal display. The apparatus calculates doses and dose rates from neutrons incident on the detector and displays a spectrum of rad or rem as a function of keV per micron of equivalent tissue and also calculates and displays accumulated dose in millirads and millirem as well as neutron dose rates in millirads per hour and millirem per hour.

  18. Portable neutron spectrometer and dosimeter

    DOEpatents

    Waechter, D.A.; Erkkila, B.H.; Vasilik, D.G.

    The disclosure relates to a battery operated neutron spectrometer/dosimeter utilizing a microprocessor, a built-in tissue equivalent LET neutron detector, and a 128-channel pulse height analyzer with integral liquid crystal display. The apparatus calculates doses and dose rates from neutrons incident on the detector and displays a spectrum of rad or rem as a function of keV per micron of equivalent tissue and also calculates and displays accumulated dose in millirads and millirem as well as neutron dose rates in millirads per hour and millirem per hour.

  19. Automated mass spectrometer grows up

    SciTech Connect

    McInteer, B.B.; Montoya, J.G.; Stark, E.E.

    1984-01-01

    In 1980 we reported the development of an automated mass spectrometer for large scale batches of samples enriched in nitrogen-15 as ammonium salts. Since that time significant technical progress has been made in the instrument. Perhaps more significantly, administrative and institutional changes have permitted the entire effort to be transferred to the private sector from its original base at the Los Alamos National Laboratory. This has ensured the continuance of a needed service to the international scientific community as revealed by a development project at a national laboratory, and is an excellent example of beneficial technology transfer to private industry.

  20. High-Resolution Imaging Spectrometer

    NASA Technical Reports Server (NTRS)

    Dozier, Jeff; Goetz, Alexander F. H.

    1990-01-01

    Earth resources observed in greater detail. High-Resolution Imaging Spectrometer, undergoing development for use in NASA's Earth Observing System, measures reflectance of Earth's surface in visible and near-infrared wavelengths. From an orbit around Earth, instrument scans surface of Earth in 200 wavelength bands simultaneously. Produces images enabling identification of minerals in rocks and soils, important algal pigments in oceans and inland waters, changes in spectra associated with biochemistry of plant canopies, compositions of atmospheric aerosols, sizes of grains in snow, and contamination of snow by impurities that absorb visible light.

  1. Wide-range CCD spectrometer

    NASA Astrophysics Data System (ADS)

    Sokolova, Elena A.; Reyes Cortes, Santiago D.

    1996-08-01

    The utilization of wide range spectrometers is a very important feature for the design of optical diagnostics. This paper describes an innovative approach, based on charged coupled device, which allows to analyze different spectral intervals with the same diffraction grating. The spectral interval is varied by changing the position of the entrance slit when the grating is stationary. The optical system can also include a spherical mirror. In this case the geometric position of the mirror is calculated aiming at compensating the first order astigmatism and the meridional coma of the grating. This device is planned to be used in Thomson scattering diagnostic of the TOKAMAK of Instituto Superior Tecnico, Lisbon (ISTTOK).

  2. Fourier-Transform Infrared Spectrometer

    NASA Technical Reports Server (NTRS)

    Schindler, R. A.

    1986-01-01

    Fourier-transform spectrometer provides approximately hundredfold increase in luminosity at detector plane over that achievable with older instruments of this type. Used to analyze such weak sources as pollutants and other low-concentration substances in atmosphere. Interferometer creates fringe patterns on two distinct arrays of light detectors, which observe different wavelength bands. Objective lens focuses scene on image plane, which contains optical chopper. To make instrument less susceptible to variations in scene under observation, field and detector lenses focus entrance aperture, rather that image, onto detector array.

  3. Static Fourier transform infrared spectrometer.

    PubMed

    Schardt, Michael; Murr, Patrik J; Rauscher, Markus S; Tremmel, Anton J; Wiesent, Benjamin R; Koch, Alexander W

    2016-04-01

    Fourier transform spectroscopy has established itself as the standard method for spectral analysis of infrared light. Here we present a robust and compact novel static Fourier transform spectrometer design without any moving parts. The design is well suited for measurements in the infrared as it works with extended light sources independent of their size. The design is experimentally evaluated in the mid-infrared wavelength region between 7.2 μm and 16 μm. Due to its large etendue, its low internal light loss, and its static design it enables high speed spectral analysis in the mid-infrared.

  4. Engine spectrometer probe and method of use

    NASA Technical Reports Server (NTRS)

    Barkhoudarian, Sarkis (Inventor); Kittinger, Scott A. (Inventor)

    2006-01-01

    The engine spectrometer probe and method of using the same of the present invention provides a simple engine spectrometer probe which is both lightweight and rugged, allowing an exhaust plume monitoring system to be attached to a vehicle, such as the space shuttle. The engine spectrometer probe can be mounted to limit exposure to the heat and debris of the exhaust plume. The spectrometer probe 50 comprises a housing 52 having an aperture 55 and a fiber optic cable 60 having a fiber optic tip 65. The fiber optic tip 65 has an acceptance angle 87 and is coupled to the aperture 55 so that the acceptance angle 87 intersects the exhaust plume 30. The spectrometer probe can generate a spectrum signal from light in the acceptance angle 506 and the spectrum signal can be provided to a spectrometer 508.

  5. Imaging spectrometer/camera having convex grating

    NASA Technical Reports Server (NTRS)

    Reininger, Francis M. (Inventor)

    2000-01-01

    An imaging spectrometer has fore-optics coupled to a spectral resolving system with an entrance slit extending in a first direction at an imaging location of the fore-optics for receiving the image, a convex diffraction grating for separating the image into a plurality of spectra of predetermined wavelength ranges; a spectrometer array for detecting the spectra; and at least one concave sperical mirror concentric with the diffraction grating for relaying the image from the entrance slit to the diffraction grating and from the diffraction grating to the spectrometer array. In one embodiment, the spectrometer is configured in a lateral mode in which the entrance slit and the spectrometer array are displaced laterally on opposite sides of the diffraction grating in a second direction substantially perpendicular to the first direction. In another embodiment, the spectrometer is combined with a polychromatic imaging camera array disposed adjacent said entrance slit for recording said image.

  6. Lunar mass spectrometer test program

    NASA Technical Reports Server (NTRS)

    Torney, F. L.; Dobrott, J. R.

    1972-01-01

    The procedures are described along with results obtained in a test program conducted to demonstrate the performance of a candidate lunar mass spectrometer. The instrument was designed to sample and measure gases believed to exist in the lunar atmosphere at the surface. The subject instrument consists of a cold cathode ion source, a small quadrupole mass analyzer and an off axis electron multiplier ion counting detector. The major program emphasis was placed on demonstrating instrument resolution, sensitivity and S/N ratio over the mass range 0-150 amu and over a partial pressure range from 10 to the minus 9th power to 10 to the minus 13th power torr. Ultrahigh vacuum tests were conducted and the minimum detectable partial pressure for neon, argon, krypton and xenon was successfully determined for the spectrometer using isotopes of these gases. With the exception of neon, the minimum detectable partial pressure is approximately 4 x 10 to the minus 14th power torr for the above gases.

  7. Miniature Ion-Array Spectrometer

    NASA Technical Reports Server (NTRS)

    Hartley, Frank T.

    2006-01-01

    A figure is shown that depicts a proposed miniature ion-mobility spectrometer that would share many features of design and operation of the instrument described in another article. The main differences between that instrument and this one would lie in the configuration and mode of operation of the filter and detector electrodes. A filter electrode and detector electrodes would be located along the sides of a drift tube downstream from the accelerator electrode. These electrodes would apply a combination of (1) a transverse AC electric field that would effect differential transverse dispersal of ions and (2) a transverse DC electric field that would drive the dispersed ions toward the detector electrodes at different distances along the drift tube. The electric current collected by each detector electrode would be a measure of the current, and thus of the abundance of the species of ions impinging on that electrode. The currents collected by all the detector electrodes could be measured simultaneously to obtain continuous readings of abundances of species. The downstream momentum of accelerated ions would be maintained through neutralization on the electrodes; the momentum of the resulting neutral atoms would serve to expel gases from spectrometer, without need for a pump.

  8. [Hadamard transform spectrometer mixed pixels' unmixing method].

    PubMed

    Yan, Peng; Hu, Bing-Liang; Liu, Xue-Bin; Sun, Wei; Li, Li-Bo; Feng, Yu-Tao; Liu, Yong-Zheng

    2011-10-01

    Hadamard transform imaging spectrometer is a multi-channel digital transform spectrometer detection technology, this paper based on digital micromirror array device (DMD) of the Hadamard transform spectrometer working principle and instrument structure, obtained by the imaging sensor mixed pixel were analyzed, theory derived the solution of pixel aliasing hybrid method, simulation results show that the method is simple and effective to improve the accuracy of mixed pixel spectrum more than 10% recovery. PMID:22250574

  9. Compact reflective imaging spectrometer utilizing immersed gratings

    DOEpatents

    Chrisp, Michael P.

    2006-05-09

    A compact imaging spectrometer comprising an entrance slit for directing light, a first mirror that receives said light and reflects said light, an immersive diffraction grating that diffracts said light, a second mirror that focuses said light, and a detector array that receives said focused light. The compact imaging spectrometer can be utilized for remote sensing imaging spectrometers where size and weight are of primary importance.

  10. Accelerator mass spectrometry in biomedical research

    SciTech Connect

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

    1993-10-20

    Biological effects occur in natural systems at chemical concentrations of parts per billion (1:10{sup 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{sup 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. {sup 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. {sup 3} H, {sup 41}Ca and {sup 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.

  11. A compact versatile femtosecond spectrometer

    NASA Astrophysics Data System (ADS)

    Nagarajan, V.; Johnson, E.; Schellenberg, P.; Parson, W.; Windeler, R.

    2002-12-01

    A compact apparatus for femtosecond pump-probe experiments is described. The apparatus is based on a cavity-dumped titanium:sapphire laser. Probe pulses are generated by focusing weak (˜1 nJ) pulses into a microstructure fiber that produces broadband continuum pulses with high efficiency. With the pump pulses compressed and probe pulses uncompressed, the rise time of the pump-probe signals is <100 fs. The 830 nm pump pulses are also frequency doubled to generate light for excitation at 415 nm. The versatility of the spectrometer is demonstrated by exciting molecules at either 830 or 415 nm, and probing at wavelengths ranging from 500 to 950 nm. Some results on the green fluorescent protein are presented.

  12. Clementine RRELAX SRAM Particle Spectrometer

    NASA Technical Reports Server (NTRS)

    Buehler, M.; Soli, G.; Blaes, B.; Ratliff, J.; Garrett, H.

    1994-01-01

    The Clementine RRELAX radiation monitor chip consists of a p-FET total dose monitor and a 4-kbit SRAM particle spectrometer. Eight of these chips were included in the RRELAX and used to detect the passage of the Clementine (S/C) and the innerstage adapter (ISA) through the earth's radiation belts and the 21-Feb 1994 solar flare. This is the first space flight for this 1.2 micron rad-soft custom CMOS radiation monitor. This paper emphasizes results from the SRAM particle detector which showed that it a) has a detection range of five orders of magnitude relative to the 21-Feb solar flare, b) is not affected by electrons, and c) detected microflares occurring with a 26.5 day period.

  13. Fluorescence imaging spectrometer optical design

    NASA Astrophysics Data System (ADS)

    Taiti, A.; Coppo, P.; Battistelli, E.

    2015-09-01

    The optical design of the FLuORescence Imaging Spectrometer (FLORIS) studied for the Fluorescence Explorer (FLEX) mission is discussed. FLEX is a candidate for the ESA's 8th Earth Explorer opportunity mission. FLORIS is a pushbroom hyperspectral imager foreseen to be embarked on board of a medium size satellite, flying in tandem with Sentinel-3 in a Sun synchronous orbit at a height of about 815 km. FLORIS will observe the vegetation fluorescence and reflectance within a spectral range between 500 and 780 nm. Multi-frames acquisitions on matrix detectors during the satellite movement will allow the production of 2D Earth scene images in two different spectral channels, called HR and LR with spectral resolution of 0.3 and 2 nm respectively. A common fore optics is foreseen to enhance by design the spatial co-registration between the two spectral channels, which have the same ground spatial sampling (300 m) and swath (150 km). An overlapped spectral range between the two channels is also introduced to simplify the spectral coregistration. A compact opto-mechanical solution with all spherical and plane optical elements is proposed, and the most significant design rationales are described. The instrument optical architecture foresees a dual Babinet scrambler, a dioptric telescope and two grating spectrometers (HR and LR), each consisting of a modified Offner configuration. The developed design is robust, stable vs temperature, easy to align, showing very high optical quality along the whole field of view. The system gives also excellent correction for transverse chromatic aberration and distortions (keystone and smile).

  14. The Geostationary Fourier Transform Spectrometer

    NASA Technical Reports Server (NTRS)

    Key, Richard; Sander, Stanley; Eldering, Annmarie; Miller, Charles; Frankenberg, Christian; Natra, Vijay; Rider, David; Blavier, Jean-Francois; Bekker, Dmitriy; Wu, Yen-Hung

    2012-01-01

    The Geostationary Fourier Transform Spectrometer (GeoFTS) is an imaging spectrometer designed for an earth science mission to measure key atmospheric trace gases and process tracers related to climate change and human activity. The GeoFTS instrument is a half meter cube size instrument designed to operate in geostationary orbit as a secondary "hosted" payload on a commercial geostationary satellite mission. The advantage of GEO is the ability to continuously stare at a region of the earth, enabling frequent sampling to capture the diurnal variability of biogenic fluxes and anthropogenic emissions from city to continental scales. The science goal is to obtain a process-based understanding of the carbon cycle from simultaneous high spatial resolution measurements of carbon dioxide (CO2), methane (CH4), carbon monoxide (CO), and chlorophyll fluorescence (CF) many times per day in the near infrared spectral region to capture their spatial and temporal variations on diurnal, synoptic, seasonal and interannual time scales. The GeoFTS instrument is based on a Michelson interferometer design with a number of advanced features incorporated. Two of the most important advanced features are the focal plane arrays and the optical path difference mechanism. A breadboard GeoFTS instrument has demonstrated functionality for simultaneous measurements in the visible and IR in the laboratory and subsequently in the field at the California Laboratory for Atmospheric Remote Sensing (CLARS) observatory on Mt. Wilson overlooking the Los Angeles basin. A GeoFTS engineering model instrument is being developed which will make simultaneous visible and IR measurements under space flight like environmental conditions (thermal-vacuum at 180 K). This will demonstrate critical instrument capabilities such as optical alignment stability, interferometer modulation efficiency, and high throughput FPA signal processing. This will reduce flight instrument development risk and show that the Geo

  15. The Geostationary Fourier Transform Spectrometer

    NASA Technical Reports Server (NTRS)

    Key, Richard; Sander, Stanley; Eldering, Annmarie; Blavier, Jean-Francois; Bekker, Dmitriy; Manatt, Ken; Rider, David; Wu, Yen-Hung

    2012-01-01

    The Geostationary Fourier Transform Spectrometer (GeoFTS) is an imaging spectrometer designed for a geostationary orbit (GEO) earth science mission to measure key atmospheric trace gases and process tracers related to climate change and human activity. GEO allows GeoFTS to continuously stare at a region of the earth for frequent sampling to capture the variability of biogenic fluxes and anthropogenic emissions from city to continental spatial scales and temporal scales from diurnal, synoptic, seasonal to interannual. The measurement strategy provides a process based understanding of the carbon cycle from contiguous maps of carbon dioxide (CO2), methane (CH4), carbon monoxide (CO), and chlorophyll fluorescence (CF) collected many times per day at high spatial resolution (2.7kmx2.7km at nadir). The CO2/CH4/CO/CF measurement suite in the near infrared spectral region provides the information needed to disentangle natural and anthropogenic contributions to atmospheric carbon concentrations and to minimize uncertainties in the flow of carbon between the atmosphere and surface. The half meter cube size GeoFTS instrument is based on a Michelson interferometer design that uses all high TRL components in a modular configuration to reduce complexity and cost. It is self-contained and as independent of the spacecraft as possible with simple spacecraft interfaces, making it ideal to be a "hosted" payload on a commercial communications satellite mission. The hosted payload approach for measuring the major carbon-containing gases in the atmosphere from the geostationary vantage point will affordably advance the scientific understating of carbon cycle processes and climate change.

  16. High resolution magnetic spectrometer SHARAQ in RIBF

    SciTech Connect

    Shimoura, S.

    2007-05-22

    For a new spectroscopy of nuclei using intense RI beams at RIBF, we started the SHARAQ project where a high-resolution SHARAQ spectrometer is being constructed together with a high-resolution secondary beam line. Physics motivation and the specification of the spectrometer are presented.

  17. Spin Spectrometer at the ALS and APS

    SciTech Connect

    Lawrence Livermore National Laboratory; University of Missouri-Rolla; Boyd Technologies; Morton, Simon A; Morton, Simon A; Tobin, James G; Yu, Sung Woo; Komesu, Takashi; Waddill, George D; Boyd, Peter

    2007-04-20

    A spin-resolving photoelectron spectrometer, the"Spin Spectrometer," has been designed and built. It has been utilized at both the Advanced Light Source in Berkeley, CA, and the Advanced Photon Source in Argonne, IL. Technical details and an example of experimental results are presented here.

  18. An improved nuclear magnetic resonance spectrometer

    NASA Technical Reports Server (NTRS)

    Elleman, D. D.; Manatt, S. L.

    1967-01-01

    Cylindrical sample container provides a high degree of nuclear stabilization to a nuclear magnetic resonance /nmr/ spectrometer. It is placed coaxially about the nmr insert and contains reference sample that gives a signal suitable for locking the field and frequency of an nmr spectrometer with a simple audio modulation system.

  19. A Mass Spectrometer Simulator in Your Computer

    ERIC Educational Resources Information Center

    Gagnon, Michel

    2012-01-01

    Introduced to study components of ionized gas, the mass spectrometer has evolved into a highly accurate device now used in many undergraduate and research laboratories. Unfortunately, despite their importance in the formation of future scientists, mass spectrometers remain beyond the financial reach of many high schools and colleges. As a result,…

  20. Compact time-of-flight mass spectrometer

    SciTech Connect

    Belov, A.S.; Kubalov, S.A.; Kuzik, V.F.; Yakushev, V.P.

    1986-02-01

    This paper describes a time-of-flight mass spectrometer developed for measuring the parameters of a pulsed hydrogen beam. The duration of an electron-beam current pulse in the ionizer of the mass spectrometer can be varied within 2-20 usec, the pulse electron current is 0.6 mA, and the electron energy is 250 eV. The time resolution of the mass spectrometer is determined by the repetition period of the electron-beam current pulses and is 40 usec. The mass spectrometer has 100% transmission in the direction of motion of molecular-beam particles. The dimension of the mass spectrometer is 7 cm in this direction. The mass resolution is sufficient for determination of the composition of the hydrogen beam.

  1. Miniature Ion-Mobility Spectrometer

    NASA Technical Reports Server (NTRS)

    Hartley, Frank T.

    2006-01-01

    The figure depicts a proposed miniature ion-mobility spectrometer that would be fabricated by micromachining. Unlike prior ion-mobility spectrometers, the proposed instrument would not be based on a time-of-flight principle and, consequently, would not have some of the disadvantageous characteristics of prior time-of-flight ion-mobility spectrometers. For example, one of these characteristics is the need for a bulky carrier-gas-feeding subsystem that includes a shutter gate to provide short pulses of gas in order to generate short pulses of ions. For another example, there is need for a complex device to generate pulses of ions from the pulses of gas and the device is capable of ionizing only a fraction of the incoming gas molecules; these characteristics preclude miniaturization. In contrast, the proposed instrument would not require a carrier-gas-feeding subsystem and would include a simple, highly compact device that would ionize all the molecules passing through it. The ionization device in the proposed instrument would be a 0.1-micron-thick dielectric membrane with metal electrodes on both sides. Small conical holes would be micromachined through the membrane and electrodes. An electric potential of the order of a volt applied between the membrane electrodes would give rise to an electric field of the order of several megavolts per meter in the submicron gap between the electrodes. An electric field of this magnitude would be sufficient to ionize all the molecules that enter the holes. Ionization (but not avalanche arcing) would occur because the distance between the ionizing electrodes would be less than the mean free path of gas molecules at the operating pressure of instrument. An accelerating grid would be located inside the instrument, downstream from the ionizing membrane. The electric potential applied to this grid would be negative relative to the potential on the inside electrode of the ionizing membrane and would be of a magnitude sufficient to

  2. [The coding correction of slit diffraction in Hadamard transform spectrometer].

    PubMed

    Li, Bo; Wang, Shu-Rong; Huang, Yu; Wang, Jun-Bo

    2013-08-01

    According to the principles of Hadamard transform spectrometer and the slit diffraction characteristics, the influence of spectrometer entrance slit diffraction of Hadamard transform spectrometer on the measurement result was analyzed, for the diffraction case, the Hadamard transform spectrometer instrument structure matrix was studied, and the Hadamard transform spectrometer encoding/decoding method was established. The analysis of incident spectral verified the correctness of the coding/ decoding. This method is very important for the high precision measurement of Hadamard transform spectrometer.

  3. The hot plasma spectrometers on Freja

    NASA Astrophysics Data System (ADS)

    Norberg, O.; Eliasson, L.

    1991-11-01

    The hot plasma instrumentation F3H on the Swedish-German Freja satellite due for launch in 1992 will consist of electron and ion spectrometers. The spectrometer Magnetic imaging Two dimensional Electron (MATE) will measure the two dimensional electron distribution in the spin plane in the energy range 0.1 to 120 keV. The ion mass spectrometer Three dimensional Ion Composition Spectrometer (TICS) measures a full three dimensional distribution in the energy range 0.5 to 15000 eV/q with high mass resolution. The instruments use a particle 'imaging' detector technique based on a large diameter microchannel plate with position sensitive anode. The topics to be studied with the Freja hot plasma spectrometers include auroral particle acceleration, heating and acceleration of ionospheric ions, and the dynamics of auroral arc systems. Of special importance to the scientific objectives is the high data rate from the Freja instrumentation, the MATE and TICS spectrometers will be sampled every 10 ms, corresponding to a spatial resolution better than 70 m at ionospheric heights. The design, simulation, and calibration of the spectrometers are discussed.

  4. Handheld spectrometers: the state of the art

    NASA Astrophysics Data System (ADS)

    Crocombe, Richard A.

    2013-05-01

    "Small" spectrometers fall into three broad classes: small versions of laboratory instruments, providing data, subsequently processed on a PC; dedicated analyzers, providing actionable information to an individual operator; and process analyzers, providing quantitative or semi-quantitative information to a process controller. The emphasis of this paper is on handheld dedicated analyzers. Many spectrometers have historically been large, possible fragile, expensive and complicated to use. The challenge over the last dozen years, as instruments have moved into the field, has been to make spectrometers smaller, affordable, rugged, easy-to-use, but most of all capable of delivering actionable results. Actionable results can dramatically improve the efficiency of a testing process and transform the way business is done. There are several keys to this handheld spectrometer revolution. Consumer electronics has given us powerful mobile platforms, compact batteries, clearly visible displays, new user interfaces, etc., while telecomm has revolutionized miniature optics, sources and detectors. While these technologies enable miniature spectrometers themselves, actionable information has demanded the development of rugged algorithms for material confirmation, unknown identification, mixture analysis and detection of suspicious materials in unknown matrices. These algorithms are far more sophisticated than the `correlation' or `dot-product' methods commonly used in benchtop instruments. Finally, continuing consumer electronics advances now enable many more technologies to be incorporated into handheld spectrometers, including Bluetooth, wireless, WiFi, GPS, cameras and bar code readers, and the continued size shrinkage of spectrometer `engines' leads to the prospect of dual technology or `hyphenated' handheld instruments.

  5. Miniature quadrupole mass spectrometer array

    NASA Technical Reports Server (NTRS)

    Chutjian, Ara (Inventor); Hecht, Michael H. (Inventor); Orient, Otto J. (Inventor)

    1997-01-01

    The present invention provides a minature quadrupole mass spectrometer array for the separation of ions, comprising a first pair of parallel, planar, nonmagnetic conducting rods each having an axis of symmetry, a second pair of planar, nonmagnetic conducting rods each having an axis of symmetry parallel to said first pair of rods and disposed such that a line perpendicular to each of said first axes of symmetry and a line perpendicular to each of said second axes of symmetry bisect each other and form a generally 90 degree angle. A nonconductive top positioning plate is positioned generally perpendicular to the first and second pairs of rods and has an aperture for ion entrance along an axis equidistant from each axis of symmetry of each of the parallel rods, a nonconductive bottom positioning plate is generally parallel to the top positioning plate and has an aperture for ion exit centered on an axis equidistant from each axis of symmetry of each of the parallel rods, means for maintaining a direct current voltage between the first and second pairs of rods, and means for applying a radio frequency voltage to the first and second pairs of rods.

  6. Miniature quadrupole mass spectrometer array

    NASA Technical Reports Server (NTRS)

    Chutjian, Ara (Inventor); Hecht, Michael H. (Inventor); Orient, Otto J. (Inventor)

    1998-01-01

    The present invention provides a minature quadrupole mass spectrometer array for the separation of ions, comprising a first pair of parallel, planar, nonmagnetic conducting rods each having an axis of symmetry, a second pair of planar, nonmagnetic conducting rods each having an axis of symmetry parallel to said first pair of rods and disposed such that a line perpendicular to each of said first axes of symmetry and a line perpendicular to each of said second axes of symmetry bisect each other and form a generally 90 degree angle. A nonconductive top positioning plate is positioned generally perpendicular to the first and second pairs of rods and has an aperture for ion entrance along an axis equidistant from each axis of symmetry of each of the parallel rods, a nonconductive bottom positioning plate is generally parallel to the top positioning plate and has an aperture for ion exit centered on an axis equidistant from each axis of symmetry of each of the parallel rods, means for maintaining a direct current voltage between the first and second pairs of rods, and means for applying a radio frequency voltage to the first and second pairs of rods.

  7. Large Isotope Spectrometer for Astromag

    NASA Technical Reports Server (NTRS)

    Binns, W. R.; Klarmann, J.; Israel, M. H.; Garrard, T. L.; Mewaldt, R. A.; Stone, E. C.; Ormes, J. F.; Streitmatter, R. E.; Rasmussen, I. L.; Wiedenbeck, M. E.

    1990-01-01

    The Large Isotope Spectrometer for Astromag (LISA) is an experiment designed to measure the isotopic composition and energy spectra of cosmic rays for elements extending from beryllium through zinc. The overall objectives of this investigation are to study the origin and evolution of galactic matter; the acceleration, transport, and time scales of cosmic rays in the galaxy; and search for heavy antinuclei in the cosmic radiation. To achieve these objectives, the LISA experiment will make the first identifications of individual heavy cosmic ray isotopes in the energy range from about 2.5 to 4 GeV/n where relativistic time dilation effects enhance the abundances of radioactive clocks and where the effects of solar modulation and cross-section variations are minimized. It will extend high resolution measurements of individual element abundances and their energy spectra to energies of nearly 1 TeV/n, and has the potential for discovering heavy anti-nuclei which could not have been formed except in extragalactic sources.

  8. Spectrometer design approaching the limit

    NASA Astrophysics Data System (ADS)

    Riesenberg, Rainer; Wuttig, Andreas; Peschel, Thomas; Damm, Christoph; Dobschal, Hans-Jürgen

    2008-09-01

    The design limits of grating array spectral sensors are discussed. The limit of a grating spectrometer with respect to the resolution is given by the diffraction limit of the grating. To approach the limit for the visible spectral region the entrance slits should reach a width of 2 μm and larger depending on wavelength and numerical aperture. The detector pixel sizes should be in the same range, which is achieved virtually by the discussed double array arrangement with a transmissive, static slit array and detector array. A number of techniques are applied for optimizing the performance as well as for miniaturization. A sub-pixel imaging including a sub-pixel analysis based on the double array arrangement virtually reduces the detector pixel sizes down to about 20%. To avoid the imaging aberrations the spectra is imaged from different entrance positions by the entrance slit array. The throughput can be increased by using a two dimensional entrance slit array, which includes a multiplex pattern or a fixed adaptive pattern. The design example of a UV-Raman spectral sensor is presented including spectral measurements.

  9. Mini-orange spectrometer at CIAE

    NASA Astrophysics Data System (ADS)

    Zheng, Yun; Wu, Xiao-Guang; Li, Guang-Sheng; Li, Cong-Bo; He, Chuang-Ye; Chen, Qi-Ming; Zhong, Jian; Zhou, Wen-Kui; Deng, Li-Tao; Zhu, Bao-Ji

    2016-08-01

    A mini-orange spectrometer used for in-beam measurements of internal conversion electrons, consisting of a Si(Li) detector and different sets of SmO5 permanent magnets for filtering and transporting the conversion electrons to the Si(Li) detector, has been developed at the China Institute of Atomic Energy. The working principles and configuration of the mini-orange spectrometer are described. The performance of the setup is illustrated by measured singles conversion electron spectra using the mini-orange spectrometer. Supported by National Natural Science Foundation of China (11305269, 11375267, 11475072, 11405274, 11205068, 11175259)

  10. Gas sampling system for a mass spectrometer

    DOEpatents

    Taylor, Charles E; Ladner, Edward P

    2003-12-30

    The present invention relates generally to a gas sampling system, and specifically to a gas sampling system for transporting a hazardous process gas to a remotely located mass spectrometer. The gas sampling system includes a capillary tube having a predetermined capillary length and capillary diameter in communication with the supply of process gas and the mass spectrometer, a flexible tube surrounding and coaxial with the capillary tube intermediate the supply of process gas and the mass spectrometer, a heat transfer tube surrounding and coaxial with the capillary tube, and a heating device in communication the heat transfer tube for substantially preventing condensation of the process gas within the capillary tube.

  11. Spectrometer for cluster ion beam induced luminescence

    SciTech Connect

    Ryuto, H. Sakata, A.; Takeuchi, M.; Takaoka, G. H.; Musumeci, F.

    2015-02-15

    A spectrometer to detect the ultra-weak luminescence originated by the collision of cluster ions on the surfaces of solid materials was constructed. This spectrometer consists of 11 photomultipliers with band-pass interference filters that can detect the luminescence within the wavelength ranging from 300 to 700 nm and of a photomultiplier without filter. The calibration of the detection system was performed using the photons emitted from a strontium aluminate fluorescent tape and from a high temperature tungsten filament. Preliminary measurements show the ability of this spectrometer to detect the cluster ion beam induced luminescence.

  12. Acousto-optic tunable filter imaging spectrometers

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin; Yu, Jeffrey; Reyes, George; Rider, David; Cheng, Li-Jen

    1991-01-01

    A remote sensing multispectral imaging instrument is being developed that uses a high resolution, fast programmable acoustooptic tunable filter (AOTF) as the spectral bandpass filter. A compact and fully computer controllable AOTF-based imaging spectrometer that operates in the visible wavelength range (0.5-0.8 microns) has been built and tested with success. A second imaging spectrometer operating in the near-infrared wavelength range (1.2-2.4 microns) is also under experimental investigation. The design criteria meeting various system issues, such as imaging quality, spectral response, and field of view (FOV), are discussed. An experiment using this AOTF imaging spectrometer breadboard is described.

  13. Spectrometer Observations Near Mawrth Vallis

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This targeted image from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) shows a region of heavily altered rock in Mars' ancient cratered highlands. The featured region is just south of Mawrth Vallis, a channel cut by floodwaters deep into the highlands.

    CRISM acquired the image at 1216 UTC (8:16 a.m. EDT) on Oct. 2, 2006, near 25.4 degrees north latitude, 340.7 degrees east longitude. It covers an area about 13 kilometers (8 miles) long and, at the narrowest point, about 9 kilometers (5.6 miles) wide. At the center of the image, the spatial resolution is as good as 35 meters (115 feet) per pixel. The image was taken in 544 colors covering 0.36-3.92 micrometers.

    This image includes four renderings of the data, all map-projected. At top left is an approximately true-color representation. At top right is false color showing brightness of the surface at selected infrared wavelengths. In the two bottom views, brightness of the surface at different infrared wavelengths has been compared to laboratory measurements of minerals, and regions that match different minerals have been colored. The bottom left image shows areas high in iron-rich clay, and the bottom right image shows areas high in aluminum-rich clay.

    Clay minerals are important to understanding the history of water on Mars because their formation requires that rocks were exposed to liquid water for a long time. Environments where they form include soils, cold springs, and hot springs. There are many clay minerals, and which ones form depends on the composition of the rock, and the temperature, acidity, and salt content of the water. CRISM's sister instrument on the Mars Express spacecraft, OMEGA, has spectrally mapped Mars at lower spatial resolution and found several regions rich in clay minerals. The Mawrth Vallis region, in particular, was found to contain iron-rich clay. CRISM is observing these regions at several tens of times higher spatial resolution, to correlate the

  14. Imaging Spectrometer on a Chip

    NASA Technical Reports Server (NTRS)

    Wang, Yu; Pain, Bedabrata; Cunningham, Thomas; Zheng, Xinyu

    2007-01-01

    A proposed visible-light imaging spectrometer on a chip would be based on the concept of a heterostructure comprising multiple layers of silicon-based photodetectors interspersed with long-wavelength-pass optical filters. In a typical application, this heterostructure would be replicated in each pixel of an image-detecting integrated circuit of the active-pixel-sensor type (see figure). The design of the heterostructure would exploit the fact that within the visible portion of the spectrum, the characteristic depth of penetration of photons increases with wavelength. Proceeding from the front toward the back, each successive long-wavelength-pass filter would have a longer cutoff wavelength, and each successive photodetector would be made thicker to enable it to absorb a greater proportion of incident longer-wavelength photons. Incident light would pass through the first photodetector and encounter the first filter, which would reflect light having wavelengths shorter than its cutoff wavelength and pass light of longer wavelengths. A large portion of the incident and reflected shorter-wavelength light would be absorbed in the first photodetector. The light that had passed through the first photodetector/filter pair of layers would pass through the second photodetector and encounter the second filter, which would reflect light having wavelengths shorter than its cutoff wavelength while passing light of longer wavelengths. Thus, most of the light reflected by the second filter would lie in the wavelength band between the cutoff wavelengths of the first and second filters. Thus, further, most of the light absorbed in the second photodetector would lie in this wavelength band. In a similar manner, each successive photodetector would detect, predominantly, light in a successively longer wavelength band bounded by the shorter cutoff wavelength of the preceding filter and the longer cutoff wavelength of the following filter.

  15. Calibration of a photomultiplier array spectrometer

    NASA Technical Reports Server (NTRS)

    Bailey, Steven A.; Wright, C. Wayne; Piazza, Charles R.

    1989-01-01

    A systematic approach to the calibration of a photomultiplier array spectrometer is presented. Through this approach, incident light radiance derivation is made by recognizing and tracing gain characteristics for each photomultiplier tube.

  16. Ultra High Mass Range Mass Spectrometer System

    DOEpatents

    Reilly, Peter T. A. [Knoxville, TN

    2005-12-06

    Applicant's present invention comprises mass spectrometer systems that operate in a mass range from 1 to 10.sup.16 DA. The mass spectrometer system comprising an inlet system comprising an aerodynamic lens system, a reverse jet being a gas flux generated in an annulus moving in a reverse direction and a multipole ion guide; a digital ion trap; and a thermal vaporization/ionization detector system. Applicant's present invention further comprises a quadrupole mass spectrometer system comprising an inlet system having a quadrupole mass filter and a thermal vaporization/ionization detector system. Applicant's present invention further comprises an inlet system for use with a mass spectrometer system, a method for slowing energetic particles using an inlet system. Applicant's present invention also comprises a detector device and a method for detecting high mass charged particles.

  17. Electro-optic Imaging Fourier Transform Spectrometer

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin

    2005-01-01

    JPL is developing an innovative compact, low mass, Electro-Optic Imaging Fourier Transform Spectrometer (E-O IFTS) for hyperspectral imaging applications. The spectral region of this spectrometer will be 1 - 2.5 micron (1000-4000/cm) to allow high-resolution, high-speed hyperspectral imaging applications. One application will be the remote sensing of the measurement of a large number of different atmospheric gases simultaneously in the same airmass. Due to the use of a combination of birefringent phase retarders and multiple achromatic phase switches to achieve phase delay, this spectrometer is capable of hyperspectral measurements similar to that of the conventional Fourier transform spectrometer but without any moving parts. In this paper, the principle of operations, system architecture and recent experimental progress will be presented.

  18. Electro-optic Imaging Fourier Transform Spectrometer

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin

    2005-01-01

    JPL is developing an innovative compact, low mass, Electro-Optic Imaging Fourier Transform Spectrometer (E-0IFTS) for hyperspectral imaging applications. The spectral region of this spectrometer will be 1 - 2.5 pm (1000 -4000 cm-') to allow high-resolution, high-speed hyperspectral imaging applications [l-51. One application will be theremote sensing of the measurement of a large number of different atmospheric gases simultaneously in the sameairmass. Due to the use of a combination of birefiingent phase retarders and multiple achromatic phase switches toachieve phase delay, this spectrometer is capable of hyperspectral measurements similar to that of the conventionalFourier transform spectrometer but without any moving parts. In this paper, the principle of operations, systemarchitecture and recent experimental progress will be presen.

  19. Electronically-Scanned Fourier-Transform Spectrometer

    NASA Technical Reports Server (NTRS)

    Breckinridge, J. B.; Ocallaghan, F. G.

    1984-01-01

    Instrument efficient, lightweight, and stable. Fourier-transform spectrometer configuration uses electronic, instead of mechanical, scanning. Configuration insensitive to vibration-induced sampling errors introduced into mechanically scanned systems.

  20. A novel digital magnetic resonance imaging spectrometer.

    PubMed

    Liu, Zhengmin; Zhao, Cong; Zhou, Heqin; Feng, Huanqing

    2006-01-01

    Spectrometer is the essential part of magnetic resonance imaging (MRI) system. It controls the transmitting and receiving of signals. Many commercial spectrometers are now available. However, they are usually costly and complex. In this paper, a new digital spectrometer based on PCI extensions for instrumentation (PXI) architecture is presented. Radio frequency (RF) pulse is generated with the method of digital synthesis and its frequency and phase are continuously tunable. MR signal acquired by receiver coils is processed by digital quadrature detection and filtered to get the k-space data, which avoid the spectral distortion due to amplitude and phase errors between two channels of traditional detection. Compared to the conventional design, the presented spectrometer is built with general PXI platform and boards. This design works in a digital manner with features of low cost, high performance and accuracy. The experiments demonstrate its efficiency.

  1. Long-Wave Infrared Dyson Spectrometer

    NASA Technical Reports Server (NTRS)

    Johnson, William R.; Hook, Simon J.; Mouroulis, Pantazis Z.; Wilson, Daniel W.; Gunapala, Sarath D.; Hill, Cory J.; Mumolo, Jason M.; Eng, Bjorn T.

    2008-01-01

    Preliminary results are presented for an ultra compact long-wave infrared slit spectrometer based on the dyson concentric design. The dyson spectrometer has been integrated in a dewar environment with a quantum well infrared photodetecor (QWIP), concave electron beam fabricated diffraction grating and ultra precision slit. The entire system is cooled to cryogenic temperatures to maximize signal to noise ratio performance, hence eliminating thermal signal from transmissive elements and internal stray light. All of this is done while maintaining QWIP thermal control. A general description is given of the spectrometer, alignment technique and predicated performance. The spectrometer has been designed for optimal performance with respect to smile and keystone distortion. A spectral calibration is performed with NIST traceable targets. A 2-point non-uniformity correction is performed with a precision blackbody source to provide radiometric accuracy. Preliminary laboratory results show excellent agreement with modeled noise equivalent delta temperature and detector linearity over a broad temperature range.

  2. Mass Spectrometer for Airborne Micro-Organisms

    NASA Technical Reports Server (NTRS)

    Sinha, M. P.; Friedlander, S. K.

    1986-01-01

    Bacteria and other micro-organisms identified continously with aid of new technique for producing samples for mass spectrometer. Technique generates aerosol of organisms and feeds to spectrometer. Given species of organism produces characteristic set of peaks in mass spectrum and thereby identified. Technique useful for monitoring bacterial makeup in environmental studies and in places where cleanliness is essential, such as hospital operating rooms, breweries, and pharmaceutical plants.

  3. Superconducting magnetic spectrometer for cosmic ray nuclei.

    NASA Technical Reports Server (NTRS)

    Smith, L. H.; Buffington, A.; Wahlig, M. A.; Dauber, P.

    1972-01-01

    This paper describes the design, calibration, and operation of a magnetic spectrometer for particle astronomy. The spectrometer consists of a superconducting magnet, optical spark chambers, scintillation detectors, and associated electronics. The instrument has been flown in a balloon gondola to 4.8 g/sq cm residual atmosphere, where it was used to analyze the charge and differential rigidity spectra of primary nuclei from 5 to 100 GeV/c.

  4. Ruggedized Spectrometers Are Built for Tough Jobs

    NASA Technical Reports Server (NTRS)

    2015-01-01

    The Mars Curiosity Chemistry and Camera instrument, or ChemCam, analyzes the elemental composition of materials on the Red Planet by using a spectrometer to measure the wavelengths of light they emit. Principal investigator Roger Wiens worked with Ocean Optics, out of Dunedin, Florida, to rework the company's spectrometer to operate in cold and rowdy conditions and also during the stresses of liftoff. Those improvements have been incorporated into the firm's commercial product line.

  5. 1987 calibration of the TFTR neutron spectrometers

    SciTech Connect

    Barnes, C.W.; Strachan, J.D.; Princeton Univ., NJ . Plasma Physics Lab.)

    1989-12-01

    The {sup 3}He neutron spectrometer used for measuring ion temperatures and the NE213 proton recoil spectrometer used for triton burnup measurements were absolutely calibrated with DT and DD neutron generators placed inside the TFTR vacuum vessel. The details of the detector response and calibration are presented. Comparisons are made to the neutron source strengths measured from other calibrated systems. 23 refs., 19 figs., 6 tabs.

  6. SUB 1-Millimeter Size Fresnel Micro Spectrometer

    NASA Technical Reports Server (NTRS)

    Park, Yeonjoon; Koch, Laura; Song, Kyo D.; Park, Sangloon; King, Glen; Choi, Sang

    2010-01-01

    An ultra-small micro spectrometer with less than 1mm diameter was constructed using Fresnel diffraction. The fabricated spectrometer has a diameter of 750 nmicrometers and a focal length of 2.4 mm at 533nm wavelength. The micro spectrometer was built with a simple negative zone plate that has an opaque center with an ecliptic shadow to remove the zero-order direct beam to the aperture slit. Unlike conventional approaches, the detailed optical calculation indicates that the ideal spectral resolution and resolving power do not depend on the miniaturized size but only on the total number of rings. We calculated 2D and 3D photon distribution around the aperture slit and confirmed that improved micro-spectrometers below 1mm size can be built with Fresnel diffraction. The comparison between mathematical simulation and measured data demonstrates the theoretical resolution, measured performance, misalignment effect, and improvement for the sub-1mm Fresnel micro-spectrometer. We suggest the utilization of an array of micro spectrometers for tunable multi-spectral imaging in the ultra violet range.

  7. NIST Calibration of a Neutron Spectrometer ROSPEC.

    PubMed

    Heimbach, Craig

    2006-01-01

    A neutron spectrometer was acquired for use in the measurement of National Institute of Standards and Technology neutron fields. The spectrometer included options for the measurement of low and high energy neutrons, for a total measurement range from 0.01 eV up to 17 MeV. The spectrometer was evaluated in calibration fields and was used to determine the neutron spectrum of an Americium-Beryllium neutron source. The calibration fields used included bare and moderated (252)Cf, monoenergetic neutron fields of 2.5 MeV and 14 MeV, and a thermal-neutron beam. Using the calibration values determined in this exercise, the spectrometer gives a good approximation of the neutron spectrum, and excellent values for neutron fluence, for all NIST calibration fields. The spectrometer also measured an Americium-Beryllium neutron field in a NIST exposure facility and determined the field quite well. The spectrometer measured scattering effects in neutron spectra which previously could be determined only by calculation or integral measurements.

  8. NIST Calibration of a Neutron Spectrometer ROSPEC

    PubMed Central

    Heimbach, Craig

    2006-01-01

    A neutron spectrometer was acquired for use in the measurement of National Institute of Standards and Technology neutron fields. The spectrometer included options for the measurement of low and high energy neutrons, for a total measurement range from 0.01 eV up to 17 MeV. The spectrometer was evaluated in calibration fields and was used to determine the neutron spectrum of an Americium-Beryllium neutron source. The calibration fields used included bare and moderated 252Cf, monoenergetic neutron fields of 2.5 MeV and 14 MeV, and a thermal-neutron beam. Using the calibration values determined in this exercise, the spectrometer gives a good approximation of the neutron spectrum, and excellent values for neutron fluence, for all NIST calibration fields. The spectrometer also measured an Americium-Beryllium neutron field in a NIST exposure facility and determined the field quite well. The spectrometer measured scattering effects in neutron spectra which previously could be determined only by calculation or integral measurements. PMID:27274944

  9. The JPL Field Emission Spectrometer

    NASA Technical Reports Server (NTRS)

    Hook, Simon J.; Kahle, Anne B.

    1995-01-01

    The Jet Propulsion Laboratory (JPL) Field Emission Spectrometer (FES) was built by Designs and Prototypes based on a set of functional requirements supplied by JPL. The instrument has a spectral resolution of 6 wavenumbers (wn) and can acquire spectra from either the Mid Infrared (3-5 mu m) or the Thermal Infrared (8-12 pm) depending on whether the InSb or HgCdTe detector is installed respectively. The instrument consists of an optical head system unit and battery. The optical head which is tripod mounted includes the interferometer and detector dewar assembly. Wavelength calibration of the interferometer is achieved using a Helium-Neon laser diode. The dewar needs replenishing with liquid Nitrogen approximately every four hours. The system unit includes the controls for operation and the computer used for acquiring viewing and processing spectra. Radiometric calibration is achieved with an external temperature-controlled blackbody that mounts on the fore-optics of the instrument. The blackbody can be set at 5 C increments between 10 and 55 C. The instrument is compact and weighs about 33 kg. Both the wavelength calibration and radiometric calibration of the instrument have been evaluated. The wavelength calibration was checked by comparison of the position of water features in a spectrum of the sky with their position in the output from a high resolution atmospheric model. The results indicatethat the features in the sky spectrum are within 6-8 wn of their position ill the model spectrum. The radiometric calibration was checked by first calibrating the instrument using the external blackbody supplied with the instrument and then measuring the radiance from another external blackbody at a series of temperatures. The temperatures of these radiance spectra were then recovered by inventing Planck's law and the recovered temperatures compared lo the measured blackbody temperature. These results indicate that radiometric calibration is good to 0.5 C over the range of

  10. Improved Cloud Condensation Nucleus Spectrometer

    NASA Technical Reports Server (NTRS)

    Leu, Ming-Taun

    2010-01-01

    An improved thermal-gradient cloud condensation nucleus spectrometer (CCNS) has been designed to provide several enhancements over prior thermal- gradient counters, including fast response and high-sensitivity detection covering a wide range of supersaturations. CCNSs are used in laboratory research on the relationships among aerosols, supersaturation of air, and the formation of clouds. The operational characteristics of prior counters are such that it takes long times to determine aerosol critical supersaturations. Hence, there is a need for a CCNS capable of rapid scanning through a wide range of supersaturations. The present improved CCNS satisfies this need. The improved thermal-gradient CCNS (see Figure 1) incorporates the following notable features: a) The main chamber is bounded on the top and bottom by parallel thick copper plates, which are joined by a thermally conductive vertical wall on one side and a thermally nonconductive wall on the opposite side. b) To establish a temperature gradient needed to establish a supersaturation gradient, water at two different regulated temperatures is pumped through tubes along the edges of the copper plates at the thermally-nonconductive-wall side. Figure 2 presents an example of temperature and supersaturation gradients for one combination of regulated temperatures at the thermally-nonconductive-wall edges of the copper plates. c) To enable measurement of the temperature gradient, ten thermocouples are cemented to the external surfaces of the copper plates (five on the top plate and five on the bottom plate), spaced at equal intervals along the width axis of the main chamber near the outlet end. d) Pieces of filter paper or cotton felt are cemented onto the interior surfaces of the copper plates and, prior to each experimental run, are saturated with water to establish a supersaturation field inside the main chamber. e) A flow of monodisperse aerosol and a dilution flow of humid air are introduced into the main

  11. The LASS (Larger Aperture Superconducting Solenoid) spectrometer

    SciTech Connect

    Aston, D.; Awaji, N.; Barnett, B.; Bienz, T.; Bierce, R.; Bird, F.; Bird, L.; Blockus, D.; Carnegie, R.K.; Chien, C.Y.

    1986-04-01

    LASS is the acronym for the Large Aperture Superconducting Solenoid spectrometer which is located in an rf-separated hadron beam at the Stanford Linear Accelerator Center. This spectrometer was constructed in order to perform high statistics studies of multiparticle final states produced in hadron reactions. Such reactions are frequently characterized by events having complicated topologies and/or relatively high particle multiplicity. Their detailed study requires a spectrometer which can provide good resolution in momentum and position over almost the entire solid angle subtended by the production point. In addition, good final state particle identification must be available so that separation of the many kinematically-overlapping final states can be achieved. Precise analyses of the individual reaction channels require high statistics, so that the spectrometer must be capable of high data-taking rates in order that such samples can be acquired in a reasonable running time. Finally, the spectrometer must be complemented by a sophisticated off-line analysis package which efficiently finds tracks, recognizes and fits event topologies and correctly associates the available particle identification information. This, together with complicated programs which perform specific analysis tasks such as partial wave analysis, requires a great deal of software effort allied to a very large computing capacity. This paper describes the construction and performance of the LASS spectrometer, which is an attempt to realize the features just discussed. The configuration of the spectrometer corresponds to the data-taking on K and K interactions in hydrogen at 11 GeV/c which took place in 1981 and 1982. This constitutes a major upgrade of the configuration used to acquire lower statistics data on 11 GeV/c K p interactions during 1977 and 1978, which is also described briefly.

  12. Microprocessor-Based Airborne Spectrometer System

    NASA Astrophysics Data System (ADS)

    Kates, John C.

    1980-08-01

    A system for airborne infrared spectral signature measurements has been developed using a Fourier transform spectrometer interfaced to a microprocessor data acquisition, control and display system. The microprocessor is a DEC LSI-ll with 20KW RAM, 4KW EPROM, DMA spectrometer interface, digital magnetic tape, and dot-matrix video graphic display. A real-time executive tailored to the requirements and resources available allows concurrent data acquisition, recording, reduction and display. Using multiple buffers, acquisition of spectrometer data via DMA is overlapped with magnetic tape output. A background task selects the most recent spectrometer data and processes it using an FFT into a raw spectrum. A reference background spectrum is subtracted to isolate the data component, then a reference instrument response function is applied to obtain a calibrated absolute irradiance spectrum. The irradiance spectrum is displayed on the video graphic display and mixed with boresight camera video to show the target spectrum superimposed on the target image. Extensive selftest facilities are incorporated for testing all system components and compatibility with data reduction systems. System calibration is supported by selection of reference blackbody temperatures, apertures, and distances. The instrument response curve obtained during calibration is displayed for verification of correct spectrometer operation or diagnosis of faults.

  13. Imaging Spectrometers Using Concave Holographic Gratings

    NASA Technical Reports Server (NTRS)

    Gradie, J.; Wang, S.

    1993-01-01

    Imaging spectroscopy combines the spatial attributes of imaging with the compositionally diagnostic attributes of spectroscopy. For spacebased remote sensing applications, mass, size, power, data rate, and application constrain the scanning approach. For the first three approaches, substantial savings in mass and size of the spectrometer can be achieved in some cases with a concave holographic grating and careful placement of an order-sorting filter. A hologram etched on the single concave surface contains the equivalent of the collimating, dispersing, and camera optics of a conventional grating spectrometer and provides substantial wavelength dependent corrections for spherical aberrations and a flat focal field. These gratings can be blazed to improve efficiency when used over a small wavelength range or left unblazed for broadband uniform efficiency when used over a wavelength range of up to 2 orders. More than 1 order can be imaged along the dispersion axis by placing an appropriately designed step order-sorting filter in front of the one- or two-dimensional detector. This filter can be shaped for additional aberration corrections. The VIRIS imaging spectrometer based on the broadband design provides simultaneous imaging of the entrance slit from lambda = 0.9 to 2.6 microns (1.5 orders) onto a 128 x 128 HgCdTe detector (at 77 K). The VIRIS spectrometer was used for lunar mapping with the UH 24.in telescope at Mauna Kea Observatory. The design is adaptable for small, low mass, space based imaging spectrometers.

  14. Spectral calibration of programmable imaging spectrometer

    NASA Astrophysics Data System (ADS)

    Du, Guojun; Liao, Zhibo; Jiao, Wenchun; Zong, Xiaoying; He, Xuhua; Wang, Haichao

    2015-10-01

    Programmable imager spectrometer can provide flexible data by changing the spectrum section number, central wavelength, spectral width and spatial resolution in orbit. Spectral calibration of imaging spectrometer plays an important role for acquiring accurate spectrum, two spectral calibration types are in essence: wavelength calibration and Full-width-half-maximum (FWHM). Base on the character of programmable imager spectrometer, designed a set of spectral calibration system. Wavelength calibration realized by utilizing the Monochromatic light of high precision monochromator, during the test, changed output parameters of monochromator according to the spectral bandwidth of imager spectrometer. The FWHM is constructed by a set of variable narrow spectrum lines that is output by tunable laser. Gaussian fitting algorithm is used to determine center wavelength and the FWHM of the characteristic spectrum line, Spectral pixels are calibrated by quadratic polynomial, standard spectroscopic lamp is used to verify wavelength calibration result accuracy. The calibration result indicates that FWHM is better than 2nm, the wavelength uncertainty is less than 0.6nm, meet the calibration requirements of programmable imaging spectrometer.

  15. Nuclear structure analysis using the Orange Spectrometer

    SciTech Connect

    Regis, J.-M.; Pascovici, Gh.; Christen, S.; Meersschout, T.; Bernards, C.; Fransen, Ch.; Dewald, A.; Braun, N.; Heinze, S.; Thiel, S.; Jolie, J.; Materna, Th.

    2009-01-28

    Recently, an Orange spectrometer, a focusing iron-free magnetic spectrometer, has been installed at a beam line of the 10 MV Tandem accelerator of the IKP of the University of Cologne. The high efficiency of 15% of 4{pi} for the detection of conversion electrons and the energy resolution of 1% makes the Orange spectrometer a powerful instrument. From the conversion electron spectrum, transition multipolarities can be determined using the so called K to L ratio. In combination with an array of germanium and lanthanum bromide detectors, e{sup -}-{gamma}-coincidences can be performed to investigate the level scheme. Moreover, the very fast lanthanum bromide scintillator with an energy resolution of 3% allows e{sup -}-{gamma} lifetime measurements down to 0.3 ns. A second Orange spectrometer can be added to build the Double Orange Spectrometer for e{sup -}-e{sup -}-coincidences. It is indispensable for lifetime measurements of low intensity or nearby lying transitions as often occur in odd-A and odd-odd nuclei. The capabilities are illustrated with several examples.

  16. Bulk and integrated acousto-optic spectrometers for molecular astronomy with heterodyne spectrometers

    NASA Technical Reports Server (NTRS)

    Chin, G.; Buhl, D.; Florez, J. M.

    1981-01-01

    A survey of acousto-optic spectrometers for molecular astronomy is presented, noting a technique of combining the acoustic bending of a collimated coherent light beam with a Bragg cell followed by an array of sensitive photodetectors. This acousto-optic spectrometer has a large bandwidth, a large number of channels, high resolution, and is energy efficient. Receiver development has concentrated on high-frequency heterodyne systems for the study of the chemical composition of the interstellar medium. RF spectrometers employing acousto-optic diffraction cells are described. Acousto-optic techniques have been suggested for applications to electronic warfare, electronic countermeasures and electronic support systems. Plans to use integrated optics for the further miniaturization of acousto-optic spectrometers are described. Bulk acousto-optic spectrometers with 300 MHz and 1 GHz bandwidths are being developed for use in the back-end of high-frequency heterodyne receivers for astronomical research.

  17. Miniature Neutron-Alpha Activation Spectrometer

    NASA Astrophysics Data System (ADS)

    Rhodes, Edgar; Holloway, James Paul; He, Zhong; Goldsten, John

    2002-10-01

    We are developing a miniature neutron-alpha activation spectrometer for in-situ analysis of chem-bio samples, including rocks, fines, ices, and drill cores, suitable for a lander or Rover platform for Mars or outer-planet missions. In the neutron-activation mode, penetrating analysis will be performed of the whole sample using a γ spectrometer and in the α-activation mode, the sample surface will be analyzed using Rutherford-backscatter and x-ray spectrometers. Novel in our approach is the development of a switchable radioactive neutron source and a small high-resolution γ detector. The detectors and electronics will benefit from remote unattended operation capabilities resulting from our NEAR XGRS heritage and recent development of a Ge γ detector for MESSENGER. Much of the technology used in this instrument can be adapted to portable or unattended terrestrial applications for detection of explosives, chemical toxins, nuclear weapons, and contraband.

  18. Compact hydrogen/helium isotope mass spectrometer

    DOEpatents

    Funsten, Herbert O.; McComas, David J.; Scime, Earl E.

    1996-01-01

    The compact hydrogen and helium isotope mass spectrometer of the present invention combines low mass-resolution ion mass spectrometry and beam-foil interaction technology to unambiguously detect and quantify deuterium (D), tritium (T), hydrogen molecule (H.sub.2, HD, D.sub.2, HT, DT, and T.sub.2), .sup.3 He, and .sup.4 He concentrations and concentration variations. The spectrometer provides real-time, high sensitivity, and high accuracy measurements. Currently, no fieldable D or molecular speciation detectors exist. Furthermore, the present spectrometer has a significant advantage over traditional T detectors: no confusion of the measurements by other beta-emitters, and complete separation of atomic and molecular species of equivalent atomic mass (e.g., HD and .sup.3 He).

  19. Partial pressure measurements with an active spectrometer

    SciTech Connect

    Brooks, N.H.; Jensen, T.H.; Colchin, R.J.; Maingi, R.; Wade, M.R.; Finkenthal, D.F.; Naumenko, N.; Tugarinov, S.

    1998-07-01

    Partial pressure neutral ga measurements have been made using a commercial Penning gauge in conjunction with an active spectrometer. In prior work utilizing bandpass filters and conventional spectrometers, trace concentrations of the hydrogen isotopes H, D, T and of the noble gases He, Ne and Ar were determined from characteristic spectral lines in the light emitted by the neutral species of these elements. For all the elements mentioned, the sensitivity was limited by spectral contamination from a pervasive background of molecular hydrogen radiation. The active spectrometer overcomes this limitations by means of a digital lock-in method and correlation with reference spectra. Preliminary measurements of an admixture containing a trace amount of neon in deuterium show better than a factor of 20 improvement in sensitivity over conventional techniques. This can be further improved by correlating the relative intensities of multiple lines to sets of reference spectra.

  20. A compact multichannel spectrometer for Thomson scattering.

    PubMed

    Schoenbeck, N L; Schlossberg, D J; Dowd, A S; Fonck, R J; Winz, G R

    2012-10-01

    The availability of high-efficiency volume phase holographic (VPH) gratings and intensified CCD (ICCD) cameras have motivated a simplified, compact spectrometer for Thomson scattering detection. Measurements of T(e) < 100 eV are achieved by a 2971 l∕mm VPH grating and measurements T(e) > 100 eV by a 2072 l∕mm VPH grating. The spectrometer uses a fast-gated (~2 ns) ICCD camera for detection. A Gen III image intensifier provides ~45% quantum efficiency in the visible region. The total read noise of the image is reduced by on-chip binning of the CCD to match the 8 spatial channels and the 10 spectral bins on the camera. Three spectrometers provide a minimum of 12 spatial channels and 12 channels for background subtraction. PMID:23126988

  1. A compact multichannel spectrometer for Thomson scattering

    SciTech Connect

    Schoenbeck, N. L.; Schlossberg, D. J.; Dowd, A. S.; Fonck, R. J.; Winz, G. R.

    2012-10-15

    The availability of high-efficiency volume phase holographic (VPH) gratings and intensified CCD (ICCD) cameras have motivated a simplified, compact spectrometer for Thomson scattering detection. Measurements of T{sub e} < 100 eV are achieved by a 2971 l/mm VPH grating and measurements T{sub e} > 100 eV by a 2072 l/mm VPH grating. The spectrometer uses a fast-gated ({approx}2 ns) ICCD camera for detection. A Gen III image intensifier provides {approx}45% quantum efficiency in the visible region. The total read noise of the image is reduced by on-chip binning of the CCD to match the 8 spatial channels and the 10 spectral bins on the camera. Three spectrometers provide a minimum of 12 spatial channels and 12 channels for background subtraction.

  2. A compact multichannel spectrometer for Thomson scatteringa)

    NASA Astrophysics Data System (ADS)

    Schoenbeck, N. L.; Schlossberg, D. J.; Dowd, A. S.; Fonck, R. J.; Winz, G. R.

    2012-10-01

    The availability of high-efficiency volume phase holographic (VPH) gratings and intensified CCD (ICCD) cameras have motivated a simplified, compact spectrometer for Thomson scattering detection. Measurements of Te < 100 eV are achieved by a 2971 l/mm VPH grating and measurements Te > 100 eV by a 2072 l/mm VPH grating. The spectrometer uses a fast-gated (˜2 ns) ICCD camera for detection. A Gen III image intensifier provides ˜45% quantum efficiency in the visible region. The total read noise of the image is reduced by on-chip binning of the CCD to match the 8 spatial channels and the 10 spectral bins on the camera. Three spectrometers provide a minimum of 12 spatial channels and 12 channels for background subtraction.

  3. Miniature, sub-nanometer resolution Talbot spectrometer.

    PubMed

    Ye, Erika; Atabaki, Amir H; Han, Ningren; Ram, Rajeev J

    2016-06-01

    Miniaturization of optical spectrometers has a significant practical value as it can enable compact, affordable spectroscopic systems for chemical and biological sensing applications. For many applications, the spectrometer must gather light from sources that span a wide range of emission angles and wavelengths. Here, we report a lens-free spectrometer that is simultaneously compact (<0.6  cm3), of high resolution (<1  nm), and has a clear aperture (of 10×10  mm). The wavelength-scale pattern in the dispersive element strongly diffracts the input light to produce non-paraxial mid-field diffraction patterns that are then recorded using an optimally matched image sensor and processed to reconstruct the spectrum.

  4. Automated calibration of a flight particle spectrometer

    NASA Technical Reports Server (NTRS)

    Torbert, Roy B.

    1986-01-01

    An automatic calibration system was designed for use in the vacuum facility at the Space Science Laboratory of the Marshall Space Flight Center. That system was developed and used in the intervening winter to calibrate the ion spectrometer that eventually flew in May 1986 aboard the NASA project, CRIT 1. During this summer, it is planned to implement the calibration of both an ion and electron spectrometer of a new design whose basic elements were conceived during the winter of 1985 to 1986. This spectrometer was completed in the summer and successfully mounted in the vacuum tank for calibration. However, the source gate valve malfunctioned, and, at the end of the summer, it still needed a replacement. During the inevitable delays in the experimental research, the numerical model of the Critical Velocity effect was completed and these results were presented.

  5. Broadband microwave absorption spectrometer for liquid media

    SciTech Connect

    Mukherjee, P.; Gosnell, T.R.; Bigio, I.J.

    1988-12-01

    A broadband, continuous-sweep microwave spectrometer has been constructed for measurements of the absorption coefficient of aqueous solutions and other liquid media. The spectrometer makes use of the phase fluctuation optical heterodyne technique, which provides a direct measure of the microwave power deposited in the sample. Consequently, in contrast to the standard dielectrometric techniques that indirectly determine the absorption coefficient via separate measurements of the real and imaginary parts of the dielectric constant, this spectrometer directly measures the microwave absorption coefficient. Broadband spectra are obtained using a transmission line to couple microwave power into the liquid sample. The absorption spectrum for deionized water in the range 3--20 GHz is presented as an example and shows excellent agreement with calculated values of the absorption coefficient based on previously published dielectric data.

  6. A neutron spectrometer using nested moderators.

    PubMed

    Dubeau, J; Hakmana Witharana, S S; Atanackovic, J; Yonkeu, A; Archambault, J P

    2012-06-01

    The design, simulation results and measurements of a new neutron energy spectrometer are presented. The device, which may be called NNS, for Nested Neutron Spectrometer, works under the same principles as a Bonner Sphere Spectrometer (BSS) System, i.e. whereby a thermal neutron detector is surrounded by a polyethylene moderator. However, the moderator is cylindrical in shape. The different thicknesses of moderator are created by inserting one cylinder into another, much like nested Russian dolls. This design results in a much lighter instrument that is also easier to use in the field. Simulations and measurements show that, despite its shape, the device can be made to offer a near angular isotropic response to neutrons and that unfolded neutron spectra are in agreement with those obtained with a more traditional BSS.

  7. Performance of an INTEGRAL spectrometer model

    NASA Technical Reports Server (NTRS)

    Jean, P.; Naya, J. E.; vonBallmoos, P.; Vedrenne, G.; Teegarden, B.

    1997-01-01

    Model calculations for the INTEGRAL spectrometer (SPI) onboard the future INTErnational Gamma Ray Astrophysics Laboratory (INTEGAL) are presented, where the sensitivity for narrow lines is based on estimates of the background level and the detection efficiency. The instrumental background rates are explained as the sum of various components that depend on the cosmic ray intensity and the spectrometer characteristics, such as the mass distribution around the Ge detectors, the passive material, the characteristics of the detector system and the background reduction techniques. Extended background calculations were performed with Monte Carlo simulations and using semi-empirical and calculated neutron and proton cross sections. In order to improve the INTEGRAL spectrometer sensitivity, several designs and background reduction techniques were compared for an instrument with a fixed detector volume.

  8. 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

    SciTech Connect

    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

  9. Degradation Free Spectrometers for Solar EUV Measurements

    NASA Astrophysics Data System (ADS)

    Wieman, S. R.; Didkovsky, L. V.; Judge, D. L.; McMullin, D. R.

    2011-12-01

    Solar EUV observations will be made using two new degradation-free EUV spectrometers on a sounding rocket flight scheduled for summer 2012. The two instruments, a rare gas photoionization-based Optics-Free Spectrometer (OFS) and a Dual Grating Spectrometer (DGS), are filter-free and optics-free. OFS can measure the solar EUV spectrum with a spectral resolution comparable to that of grating-based EUV spectrometers. The DGS selectable spectral bandwidth is designed to provide solar irradiance in a 10 nm band centered on the Lyman-alpha 121.6 nm line and a 4 nm band centered on the He-II 30.4 nm line to overlap EUV observations from the SDO/EUV Variability Experiment (EVE) and the SOHO/Solar EUV Monitor (SEM). A clone of the SOHO/SEM flight instrument and a Rare Gas Ionization Cell (RGIC) absolute EUV detector will also be flown to provide additional measurements for inter-comparison. Program delays related to the sounding rocket flight termination system, which was no longer approved by the White Sands Missile Range prevented the previously scheduled summer 2011 launch of these instruments. During this delay several enhancements have been made to the sounding rocket versions of the DFS instruments, including a lighter, simplified vacuum housing and gas system for the OFS and an improved mounting for the DGS, which allows more accurate co-alignment of the optical axes of the DGS, OFS, and the SOHO/SEM clone. Details of these enhancements and results from additional lab testing of the instruments are reported here. The spectrometers are being developed and demonstrated as part of the Degradation Free Spectrometers (DFS) project under NASA's Low Cost Access to Space (LCAS) program and are supported by NASA Grant NNX08BA12G.

  10. Vacuum system for the SAMURAI spectrometer

    NASA Astrophysics Data System (ADS)

    Shimizu, Y.; Otsu, H.; Kobayashi, T.; Kubo, T.; Motobayashi, T.; Sato, H.; Yoneda, K.

    2013-12-01

    The first commissioning experiment of the SAMURAI spectrometer and its beam line was performed in March, 2012. The vacuum system for the SAMURAI spectrometer includes its beam line and the SAMURAI vacuum chamber with the windows for detecting neutrons and charged particles. The window for neutrons was made of stainless steel with a thickness of 3 mm and was designed with a shape of partial cylinder to support itself against the atmospheric pressure. The window for charged particles was of the combination of Kevlar and Mylar with the thickness of 280 and 75 μm, respectively. The pressure in the vacuum system was at a few Pa throughout the commissioning experiment.

  11. NEAR Gamma Ray Spectrometer Characterization and Repair

    NASA Technical Reports Server (NTRS)

    Groves, Joel Lee; Vajda, Stefan

    1998-01-01

    This report covers the work completed in the third year of the contract. The principle activities during this period were (1) the characterization of the NEAR 2 Gamma Ray Spectrometer using a neutron generator to generate complex gamma ray spectra and a large Ge Detecter to identify all the major peaks in the spectra; (2) the evaluation and repair of the Engineering Model Unit of the Gamma Ray Spectrometer for the NEAR mission; (3) the investigation of polycapillary x-ray optics for x-ray detection; and (4) technology transfer from NASA to forensic science.

  12. Improved real-time imaging spectrometer

    NASA Technical Reports Server (NTRS)

    Lambert, James L. (Inventor); Chao, Tien-Hsin (Inventor); Yu, Jeffrey W. (Inventor); Cheng, Li-Jen (Inventor)

    1993-01-01

    An improved AOTF-based imaging spectrometer that offers several advantages over prior art AOTF imaging spectrometers is presented. The ability to electronically set the bandpass wavelength provides observational flexibility. Various improvements in optical architecture provide simplified magnification variability, improved image resolution and light throughput efficiency and reduced sensitivity to ambient light. Two embodiments of the invention are: (1) operation in the visible/near-infrared domain of wavelength range 0.48 to 0.76 microns; and (2) infrared configuration which operates in the wavelength range of 1.2 to 2.5 microns.

  13. The Constellation-X Reflection Grating Spectrometer

    NASA Technical Reports Server (NTRS)

    Allen, Jean C.

    2006-01-01

    The Reflection Grating Spectrometer on the Constellation-X mission will provide high sensitivity, high-resolution spectra in the soft x-ray band. The RGS performance requirements are specified as a resolving power of greater than 300 and an effective area of greater than 1000 sq cm across most of the 0.25 to 2.0 keV band. These requirements are driven by the science goals of the mission. We will describe the performance requirements and goals, the reference design of the spectrometer, and examples of science cases where we expect data from the RGS to significantly advance our current understanding of the universe.

  14. Acousto-optic spectrometer for radio astronomy

    NASA Technical Reports Server (NTRS)

    Chin, G.; Buhl, D.; Florez, J. M.

    1980-01-01

    A prototype acousto-optic spectrometer which uses a discrete bulk acoustic wave Itek Bragg cell, 5 mW Helium Neon laser, and a 1024 element Reticon charge coupled photodiode array is described. The analog signals from the photodiode array are digitized, added, and stored in a very high speed custom built multiplexer board which allows synchronous detection of weak signals to be performed. The experiment is controlled and the data are displayed and stored with an LSI-2 microcomputer system with dual floppy discs. The performance of the prototype acousto-optic spectrometer obtained from initial tests is reported.

  15. [Superhigh spectral resolution measurement of spectrometer].

    PubMed

    Liu, Sheng-Gang; Weng, Ji-Dong; Tao, Tian-Jiong

    2013-04-01

    The spectral resolution is one of the most important indexes of spectrometer. A new method is put forward for measuring the superhigh spectral resolution based on the Rayleigh criterion and the optical heterodyne, and the uncertainty of this method is analyzed. The spectral resolution of some spectrometer was measured using this method, and the experimental results show that the spectral resolution is higher than 18.9 pm, and the standard uncertainty is 2.3 pm. When showed using wave number, the spectral resolution is higher than 0.078 8 cm(-1), and the standard uncertainty is 0.009 6 cm(-1).

  16. Beam Shape Effects on Grating Spectrometer Resolution

    NASA Technical Reports Server (NTRS)

    Erickson, Edwin F.; Rabanus, David; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    The collimated optical beam in a grating spectrometer may be circular or elliptical in cross section, so that different parts of the beam illuminate different numbers of grooves on the grating. Here we estimate the consequent loss in spectral resolution relative to that obtained with a beam which illuminates a fixed number of grooves. For representative diffraction resolution functions, the effect is to reduce the intrinsic resolving power of the spectrometer by about 13%, exclusive of other contributions such as finite entrance slit width.

  17. MICE Spectrometer Solenoid Magnetic Field Measurements

    SciTech Connect

    Leonova, M.

    2013-09-01

    The Muon Ionization Cooling Experiment (MICE) is designed to demonstrate ionization cooling in a muon beam. Its goal is to measure a 10% change in transverse emittance of a muon beam going through a prototype Neutrino Factory cooling channel section with an absolute measurement accuracy of 0.1%. To measure emittances, MICE uses two solenoidal spectrometers, with Solenoid magnets designed to have 4 T fields, uniform at 3 per mil level in the tracking volumes. Magnetic field measurements of the Spectrometer Solenoid magnet SS2, and analysis of coil parameters for input into magnet models will be discussed.

  18. Wide size range fast integrated mobility spectrometer

    DOEpatents

    Wang, Jian

    2013-10-29

    A mobility spectrometer to measure a nanometer particle size distribution is disclosed. The mobility spectrometer includes a conduit and a detector. The conduit is configured to receive and provide fluid communication of a fluid stream having a charged nanometer particle mixture. The conduit includes a separator section configured to generate an electrical field of two dimensions transverse to a dimension associated with the flow of the charged nanometer particle mixture through the separator section to spatially separate charged nanometer particles of the charged nanometer particle mixture in said two dimensions. The detector is disposed downstream of the conduit to detect concentration and position of the spatially-separated nanometer particles.

  19. Compact Imaging Spectrometer Utilizing Immersed Gratings

    DOEpatents

    Chrisp, Michael P.; Lerner, Scott A.; Kuzmenko, Paul J.; Bennett, Charles L.

    2006-03-21

    A compact imaging spectrometer with an immersive diffraction grating that compensates optical distortions. The imaging spectrometer comprises an entrance slit for transmitting light, a system for receiving the light and directing the light, an immersion grating, and a detector array. The entrance slit, the system for receiving the light, the immersion grating, and the detector array are positioned wherein the entrance slit transmits light to the system for receiving the light and the system for receiving the light directs the light to the immersion grating and the immersion grating receives the light and directs the light through an optical element to the detector array.

  20. Time-of-flight Fourier UCN spectrometer

    NASA Astrophysics Data System (ADS)

    Kulin, G. V.; Frank, A. I.; Goryunov, S. V.; Kustov, D. V.; Geltenbort, P.; Jentschel, M.; Lauss, B.; Schmidt-Wellenburg, P.

    2016-05-01

    We describe a new time-of-flight Fourier spectrometer for investigation of UCN diffraction by a moving grating. The device operates in the regime of a discrete set of modulation frequencies. The results of the first experiments show that the spectrometer may be used for obtaining UCN energy spectra in the energy range of 60 - 200 neV with a resolution of about 5 neV. The accuracy of determination of the line position was estimated to be several units of 10-10 eV.

  1. Automated calibration of a flight particle spectrometer

    NASA Technical Reports Server (NTRS)

    Torbert, R. B.

    1986-01-01

    A system for calibrating both electron and ion imaging particle spectrometers was devised to calibrate flight instruments in a large vacuum facility in the Space Science Laboratory at the Marshall Space Flight Center. An IBM-compatible computer was used to control, via an IEEE 488 buss protocol, a two-axis gimbled table, constructed to fit inside the tank. Test settings of various diagnostic voltages were also acquired via the buss. These spectrometers constructed by the author at UCSD were calibrated in an automatic procedure programmed on the small computer. Data was up-loaded to the SSL VAX where a program was developed to plot the results.

  2. NASA applications for acousto-optic spectrometers

    NASA Technical Reports Server (NTRS)

    Chin, G.

    1984-01-01

    Small, compact, and rugged IF spectrometers are needed in high resolution heterodyne receivers designed for a new generation of space-borne telescopes planned for the next decade. Acousto-optic Spectrometers (AOS) promise to provide the necessary bandwidth and resolution in a package which is compact, power efficient, and ruggedized for space applications. Sensitivity, linearity, and stability are the primary goals of an astronomical receiver and these features must be demonstrated in order for an AOS to be accepted in place of more conventional RF or digital technology.

  3. Electron-ion-x-ray spectrometer system

    SciTech Connect

    Southworth, S.H.; Deslattes, R.D.; MacDonald, M.A.; LeBrun, T.

    1993-10-01

    The authors describe a spectrometer system developed for electron, ion, and x-ray spectroscopy of gas-phase atoms and molecules following inner-shell excitation by tunable synchrotron radiation. The spectrometer has been used on beamline X-24A at the National Synchrotron Light Source for excitation-dependent studies of Ar L-shell and K-shell photoexcitation and vacancy decay processes. The instrumentation and experimental methods are discussed, and examples are given of electron spectra and coincidence spectra between electrons and fluorescent x-rays.

  4. Noiseless coding for the Gamma Ray spectrometer

    NASA Technical Reports Server (NTRS)

    Rice, R.; Lee, J. J.

    1985-01-01

    The payload of several future unmanned space missions will include a sophisticated gamma ray spectrometer. Severely constrained data rates during certain portions of these missions could limit the possible science return from this instrument. This report investigates the application of universal noiseless coding techniques to represent gamma ray spectrometer data more efficiently without any loss in data integrity. Performance results demonstrate compression factors from 2.5:1 to 20:1 in comparison to a standard representation. Feasibility was also demonstrated by implementing a microprocessor breadboard coder/decoder using an Intel 8086 processor.

  5. Multimedia. TAM Topical Guide #1.

    ERIC Educational Resources Information Center

    Boone, Randall, Ed.; Higgins, Kyle, Ed.

    Educational multimedia and hypermedia systems, which integrate computer-generated text and graphics with full-motion video and stereo sound, dominate much discussion about the future of computer use in education. This guide brings together the thoughts, ideas, and experience of elementary school students, classroom teachers, administrators,…

  6. An object-based image analysis approach for aquaculture ponds precise mapping and monitoring: a case study of Tam Giang-Cau Hai Lagoon, Vietnam.

    PubMed

    Virdis, Salvatore Gonario Pasquale

    2014-01-01

    Monitoring and mapping shrimp farms, including their impact on land cover and land use, is critical to the sustainable management and planning of coastal zones. In this work, a methodology was proposed to set up a cost-effective and reproducible procedure that made use of satellite remote sensing, object-based classification approach, and open-source software for mapping aquaculture areas with high planimetric and thematic accuracy between 2005 and 2008. The analysis focused on two characteristic areas of interest of the Tam Giang-Cau Hai Lagoon (in central Vietnam), which have similar farming systems to other coastal aquaculture worldwide: the first was primarily characterised by locally referred "low tide" shrimp ponds, which are partially submerged areas; the second by earthed shrimp ponds, locally referred to as "high tide" ponds, which are non-submerged areas on the lagoon coast. The approach was based on the region-growing segmentation of high- and very high-resolution panchromatic images, SPOT5 and Worldview-1, and the unsupervised clustering classifier ISOSEG embedded on SPRING non-commercial software. The results, the accuracy of which was tested with a field-based aquaculture inventory, showed that in favourable situations (high tide shrimp ponds), the classification results provided high rates of accuracy (>95 %) through a fully automatic object-based classification. In unfavourable situations (low tide shrimp ponds), the performance degraded due to the low contrast between the water and the pond embankments. In these situations, the automatic results were improved by manual delineation of the embankments. Worldview-1 necessarily showed better thematic accuracy, and precise maps have been realised at a scale of up to 1:2,000. However, SPOT5 provided comparable results in terms of number of correctly classified ponds, but less accurate results in terms of the precision of mapped features. The procedure also demonstrated high degrees of reproducibility

  7. Hybrid plasmon photonic crystal resonance grating for integrated spectrometer biosensor.

    PubMed

    Guo, Hong; Guo, Junpeng

    2015-01-15

    Using nanofabricated hybrid metal-dielectric nanohole array photonic crystal gratings, a hybrid plasmonic optical resonance spectrometer biosensor is demonstrated. The new spectrometer sensor technique measures plasmonic optical resonance from the first-order diffraction rather than via the traditional method of measuring optical resonance from transmission. The resonance spectra measured with the new spectrometer technique are compared with the spectra measured using a commercial optical spectrometer. It is shown that the new optical resonance spectrometer can be used to measure plasmonic optical resonance that otherwise cannot be measured with a regular optical spectrometer. PMID:25679856

  8. Hybrid plasmon photonic crystal resonance grating for integrated spectrometer biosensor.

    PubMed

    Guo, Hong; Guo, Junpeng

    2015-01-15

    Using nanofabricated hybrid metal-dielectric nanohole array photonic crystal gratings, a hybrid plasmonic optical resonance spectrometer biosensor is demonstrated. The new spectrometer sensor technique measures plasmonic optical resonance from the first-order diffraction rather than via the traditional method of measuring optical resonance from transmission. The resonance spectra measured with the new spectrometer technique are compared with the spectra measured using a commercial optical spectrometer. It is shown that the new optical resonance spectrometer can be used to measure plasmonic optical resonance that otherwise cannot be measured with a regular optical spectrometer.

  9. Extinction of Harrington's mountain goat.

    PubMed

    Mead, J I; Martin, P S; Euler, R C; Long, A; Jull, A J; Toolin, L J; Donahue, D J; Linick, T W

    1986-02-01

    Keratinous horn sheaths of the extinct Harrington's mountain goat, Oreamnos harringtoni, were recovered at or near the surface of dry caves of the Grand Canyon, Arizona. Twenty-three separate specimens from two caves were dated nondestructively by the tandem accelerator mass spectrometer (TAMS). Both the TAMS and the conventional dates indicate that Harrington's mountain goat occupied the Grand Canyon for at least 19,000 years prior to becoming extinct by 11,160 +/- 125 radiocarbon years before present. The youngest average radiocarbon dates on Shasta ground sloths, Nothrotheriops shastensis, from the region are not significantly younger than those on extinct mountain goats. Rather than sequential extinction with Harrington's mountain goat disappearing from the Grand Canyon before the ground sloths, as one might predict in view of evidence of climatic warming at the time, the losses were concurrent. Both extinctions coincide with the regional arrival of Clovis hunters.

  10. Extinction of Harrington's mountain goat

    SciTech Connect

    Mead, J.I.; Martin, P.S.; Euler, R.C.; Long, A.; Jull, A.J.T.; Toolin, L.J.; Donahue, D.J.; Linick, T.W.

    1986-02-01

    Keratinous horn sheaths of the extinct Harrington's mountain goat, Oreamnos harringtoni, were recovered at or near the surface of dry caves of the Grand Canyon, Arizona. Twenty-three separate specimens from two caves were dated nondestructively by the tandem accelerator mass spectrometer (TAMS). Both the TAMS and the conventional dates indicate that Harrington's mountain goat occupied the Grand Canyon for at least 19,000 years prior to becoming extinct by 11,160 +/- 125 radiocarbon years before present. The youngest average radiocarbon dates on Shasta ground sloths, Nothrotheriops shastensis, from the region are not significantly younger than those on extinct mountain goats. Rather than sequential extinction with Harrington's mountain goat disappearing from the Grand Canyon before the ground sloths, as one might predict in view of evidence of climatic warming at the time, the losses were concurrent. Both extinctions coincide with the regional arrival of Clovis hunters.

  11. Extinction of Harrington's Mountain Goat

    NASA Astrophysics Data System (ADS)

    Mead, Jim I.; Martin, Paul S.; Euler, Robert C.; Long, Austin; Jull, A. J. T.; Toolin, Laurence J.; Donahue, Douglas J.; Linick, T. W.

    1986-02-01

    Keratinous horn sheaths of the extinct Harrington's mountain goat, Oreamnos harringtoni, were recovered at or near the surface of dry caves of the Grand Canyon, Arizona. Twenty-three separate specimens from two caves were dated nondestructively by the tandem accelerator mass spectrometer (TAMS). Both the TAMS and the conventional dates indicate that Harrington's mountain goat occupied the Grand Canyon for at least 19,000 years prior to becoming extinct by 11,160 ± 125 radiocarbon years before present. The youngest average radiocarbon dates on Shasta ground sloths, Nothrotheriops shastensis, from the region are not significantly younger than those on extinct mountain goats. Rather than sequential extinction with Harrington's mountain goat disappearing from the Grand Canyon before the ground sloths, as one might predict in view of evidence of climatic warming at the time, the losses were concurrent. Both extinctions coincide with the regional arrival of Clovis hunters.

  12. Determination of CA-41, I-129 and OS-187 in the Rochester tandem accelerator and some applications of these isotopes

    NASA Technical Reports Server (NTRS)

    Fehn, U.; Elmore, D.; Gove, H. E.; Kubik, P.; Teng, R.; Tubbs, L.

    1986-01-01

    The measurement of Ca-41 and I-129 utilizing the Rochester Tanden Accelerator Mass Spectrometer (TAMS) is discussed. Ca-41, having a half-life of 100,000 yrs., is of potential use for the dating of ground water as well as of bones in the age range between 50,000 and 1 million yrs. A major problem for the measurement of Ca-41 with TAMS is the fact that calcium does not readily form negative atomic ions. It does, however, form negative molecular ions. The production of CaO ions from compounds such as CaO and CaCO3 and from free Ca molecules sprayed with oxygen gas was studied. A project to utilize I-129 as a tracer for hydrothermal convection in sediment-covered oceanic crust is also briefly described. Finally, plans to use the Os-187/Os-186 ratio for the determination of extraterrestrial material in the Ries crater in Germany are summarized.

  13. Pump Effects in Planetary Mass Spectrometers

    NASA Technical Reports Server (NTRS)

    Mahaffy, Paul; Harpold, Dan

    1999-01-01

    Mass spectrometers provide a useful tool in solar system exploration since fundamental questions of Solar System formation and evolution may be constrained by models based on the chemical and isotopic data provided by these instruments. For example, comparison of such data between the atmospheres of the terrestrial planets enables an understanding of mechanisms of atmospheric loss to space and production sources such as from planetary outgassing and from infall from objects such as comets. Over the past 25 years, mass spectrometers have been sent to Mars, Venus, Comet Halley, and Jupiter and are presently in transit to the Saturnian system to sample the atmosphere of Saturn's moon Titan. The quality of data derived from a very small, lightweight, and rugged instrument is constrained not only by the mass analyzer itself, but also by the performance of its gas sampling and pumping systems. A comparison of several planetary mass spectrometer experiments is provided with a focus on the demands placed on the gas processing and pumping systems. For example, the figure below is a mass spectrum from deep in the atmosphere of Jupiter obtained from a quadrupole mass spectrometer developed in the early 1980's for the Galileo Probe (Niemann et al., Space Sci. Rev., 60, 111-142 (1992)). Measurements of Jovian noble gases and other species with this system is described.

  14. Digital Signal Processing in the GRETINA Spectrometer

    NASA Astrophysics Data System (ADS)

    Cromaz, Mario

    2015-10-01

    Developments in the segmentation of large-volume HPGe crystals has enabled the development of high-efficiency gamma-ray spectrometers which have the ability to track the path of gamma-rays scattering through the detector volume. This technology has been successfully implemented in the GRETINA spectrometer whose high efficiency and ability to perform precise event-by-event Doppler correction has made it an important tool in nuclear spectroscopy. Tracking has required the spectrometer to employ a fully digital signal processing chain. Each of the systems 1120 channels are digitized by 100 Mhz, 14-bit flash ADCs. Filters that provide timing and high-resolution energies are implemented on local FPGAs acting on the ADC data streams while interaction point locations and tracks, derived from the trace on each detector segment, are calculated in real time on a computing cluster. In this presentation we will give a description of GRETINA's digital signal processing system, the impact of design decisions on system performance, and a discussion of possible future directions as we look towards soon developing larger spectrometers such as GRETA with full 4 π solid angle coverage. This work was supported by the Office of Science in the Department of Energy under grant DE-AC02-05CH11231.

  15. Advanced Laboratory NMR Spectrometer with Applications.

    ERIC Educational Resources Information Center

    Biscegli, Clovis; And Others

    1982-01-01

    A description is given of an inexpensive nuclear magnetic resonance (NMR) spectrometer suitable for use in advanced laboratory courses. Applications to the nondestructive analysis of the oil content in corn seeds and in monitoring the crystallization of polymers are presented. (SK)

  16. Neutron spectrometer for fast nuclear reactors

    NASA Astrophysics Data System (ADS)

    Osipenko, M.; Ripani, M.; Ricco, G.; Caiffi, B.; Pompili, F.; Pillon, M.; Angelone, M.; Verona-Rinati, G.; Cardarelli, R.; Mila, G.; Argiro, S.

    2015-11-01

    In this paper we describe the development and first tests of a neutron spectrometer designed for high flux environments, such as the ones found in fast nuclear reactors. The spectrometer is based on the conversion of neutrons impinging on 6Li into α and t whose total energy comprises the initial neutron energy and the reaction Q-value. The 6LiF layer is sandwiched between two CVD diamond detectors, which measure the two reaction products in coincidence. The spectrometer was calibrated at two neutron energies in well known thermal and 3 MeV neutron fluxes. The measured neutron detection efficiency varies from 4.2 ×10-4 to 3.5 ×10-8 for thermal and 3 MeV neutrons, respectively. These values are in agreement with Geant4 simulations and close to simple estimates based on the knowledge of the 6Li(n,α)t cross-section. The energy resolution of the spectrometer was found to be better than 100 keV when using 2.5 or 5 m cables between the detector and the preamplifiers.

  17. Reflecting Schmidt/Littrow Prism Imaging Spectrometer

    NASA Technical Reports Server (NTRS)

    Breckinridge, J. B.; Page, N. A.; Shack, R. V.; Shannon, R. R.

    1985-01-01

    High resolution achieved with wide field of view. Imaging Spectrometer features off-axis reflecting optics, including reflecting "slit" that also serves as field flattener. Only refracting element is prism. By scanning slit across object or scene and timing out signal, both spectral and spatial information in scene are obtained.

  18. HyTES: Thermal Imaging Spectrometer Development

    NASA Technical Reports Server (NTRS)

    Johnson, William R.; Hook, Simon J.; Mouroulis, Pantazis; Wilson, Daniel W.; Gunapala, Sarath D.; Realmuto, Vincent; Lamborn, Andy; Paine, Chris; Mumolo, Jason M.; Eng, Bjorn T.

    2011-01-01

    The Jet Propulsion Laboratory has developed the Hyperspectral Thermal Emission Spectrometer (HyTES). It is an airborne pushbroom imaging spectrometer based on the Dyson optical configuration. First low altitude test flights are scheduled for later this year. HyTES uses a compact 7.5-12 micrometer m hyperspectral grating spectrometer in combination with a Quantum Well Infrared Photodetector (QWIP) and grating based spectrometer. The Dyson design allows for a very compact and optically fast system (F/1.6). Cooling requirements are minimized due to the single monolithic prism-like grating design. The configuration has the potential to be the optimal science-grade imaging spectroscopy solution for high altitude, lighter-than-air (HAA, LTA) vehicles and unmanned aerial vehicles (UAV) due to its small form factor and relatively low power requirements. The QWIP sensor allows for optimum spatial and spectral uniformity and provides adequate responsivity which allows for near 100mK noise equivalent temperature difference (NEDT) operation across the LWIR passband. The QWIP's repeatability and uniformity will be helpful for data integrity since currently an onboard calibrator is not planned. A calibration will be done before and after eight hour flights to gage any inconsistencies. This has been demonstrated with lab testing. Further test results show adequate NEDT, linearity as well as applicable earth science emissivity target results (Silicates, water) measured in direct sunlight.

  19. Matching the Spectrometers on board ISO

    NASA Astrophysics Data System (ADS)

    Burgdorf, M.; Feuchtgruber, H.; Salama, A.; García-Lario, P.; Müller, T.; Lord, S.

    We report on the findings of the Spectral Matching Working Group, the main aim of which was to investigate discontinuities between SWS and LWS in complete ISO spectra from 2 - 200 μm. In order to check in a quantitative way the agreement between the two spectrometers, a software tool was developed which automatically selected observations made with SWS and LWS on the same coordinates and which calculated the ratio of the fluxes in the overlap region from the browser products. In this way all observations suitable for this cross-calibration exercise could be selected, provided that they were performed with standard Astronomical Observing Templates and covered the wavelength range that SWS and LWS have in common. 95% of those targets which were neither extended nor variable showed an agreement better than 20% between the two spectrometers. Several problems with the data from the instruments, like saturation effects, detector transients and discontinuities between the sub-spectra from different detectors, affect both spectrometers in a similar way and require special processing steps. We show, for some solar system objects, to which extent the spectra taken with ISO from the mid- to the far-infrared agree with theoretical models. Furthermore, we discuss for the example of Neptune how the combined information from both spectrometers can be used to put new constraints on models of objects that are possible calibration standards for future missions.

  20. Evaluation of Small Mass Spectrometer Systems

    NASA Technical Reports Server (NTRS)

    Arkin, C. Richard; Griffin, Timothy P.; Ottens, Andrew K.; Diaz, Jorge A.; Follistein, Duke W.; Adams, Fredrick W.; Helms, William R.; Voska, N. (Technical Monitor)

    2002-01-01

    Various mass analyzer systems were evaluated. Several systems show promise, including the Stanford Research Systems RGA-100, Inficon XPR-2, the University of Florida's Ion Trap, and the Compact Double Focus Mass Spectrometer. Areas that need improvement are the response time, recovery time, system volume, and system weight. Future work will investigate techniques to improve systems and will evaluate engineering challenges.

  1. Machined electrostatic sector for mass spectrometer

    NASA Technical Reports Server (NTRS)

    Sinha, Mahadeva P. (Inventor)

    2001-01-01

    An electrostatic sector device for a mass spectrometer is formed from a single piece of machinable ceramic. The machined ceramic is coated with a nickel coating, and a notch is etched in the nickel coating to form two separated portions. The sector can be covered by a cover formed from a separate piece of machined ceramic.

  2. Livermore Imaging Fourier Transform Infrared Spectrometer (LIFTIRS)

    SciTech Connect

    Carter, M.R.; Bennett, C.L.; Fields, D.J.; Lee, F.D.

    1995-05-10

    Lawrence Livermore National Laboratory is currently operating a hyperspectral imager, the Livermore Imaging Fourier Transform Infrared Spectrometer (LIFTIRS). This instrument is capable of operating throughout the infrared spectrum from 3 to 12.5 {mu}m with controllable spectral resolution. In this presentation we report on it`s operating characteristics, current capabilities, data throughput and calibration issues.

  3. Lens system for a photo ion spectrometer

    DOEpatents

    Gruen, Dieter M.; Young, Charles E.; Pellin, Michael J.

    1990-01-01

    A lens system in a photo ion spectrometer for manipulating a primary ion beam and ionized atomic component. The atomic components are removed from a sample by a primary ion beam using the lens system, and the ions are extracted for analysis. The lens system further includes ionization resistant coatings for protecting the lens system.

  4. Imaging mass spectrometer with mass tags

    DOEpatents

    Felton, James S.; Wu, Kuang Jen J.; Knize, Mark G.; Kulp, Kristen S.; Gray, Joe W.

    2013-01-29

    A method of analyzing biological material by exposing the biological material to a recognition element, that is coupled to a mass tag element, directing an ion beam of a mass spectrometer to the biological material, interrogating at least one region of interest area from the biological material and producing data, and distributing the data in plots.

  5. Imaging mass spectrometer with mass tags

    DOEpatents

    Felton, James S.; Wu, Kuang Jen; Knize, Mark G.; Kulp, Kristen S.; Gray, Joe W.

    2010-06-01

    A method of analyzing biological material by exposing the biological material to a recognition element, that is coupled to a mass tag element, directing an ion beam of a mass spectrometer to the biological material, interrogating at least one region of interest area from the biological material and producing data, and distributing the data in plots.

  6. Compact imaging spectrometer utilizing immersed gratings

    DOEpatents

    Lerner, Scott A.

    2005-12-20

    A compact imaging spectrometer comprising an entrance slit for directing light, lens means for receiving the light, refracting the light, and focusing the light; an immersed diffraction grating that receives the light from the lens means and defracts the light, the immersed diffraction grating directing the detracted light back to the lens means; and a detector that receives the light from the lens means.

  7. Lens system for a photo ion spectrometer

    DOEpatents

    Gruen, D.M.; Young, C.E.; Pellin, M.J.

    1990-11-27

    A lens system in a photo ion spectrometer for manipulating a primary ion beam and ionized atomic component is disclosed. The atomic components are removed from a sample by a primary ion beam using the lens system, and the ions are extracted for analysis. The lens system further includes ionization resistant coatings for protecting the lens system. 8 figs.

  8. Multi-channel electric aerosol spectrometer

    NASA Astrophysics Data System (ADS)

    Mirme, A.; Noppel, M.; Peil, I.; Salm, J.; Tamm, E.; Tammet, H.

    Multi-channel electric mobility spectrometry is a most efficient technique for the rapid measurement of an unstable aerosol particle size spectrum. The measuring range of the spectrometer from 10 microns to 10 microns is achieved by applying diffusional and field charging mechanisms simultaneously. On-line data processing is carried out with a microcomputer. Experimental calibration ensures correctness of measurement.

  9. Broadband Infrared Heterodyne Spectrometer: Final Report

    SciTech Connect

    Stevens, C G; Cunningham, C T; Tringe, J W

    2010-12-16

    This report summarizes the most important results of our effort to develop a new class of infrared spectrometers based on a novel broadband heterodyne design. Our results indicate that this approach could lead to a near-room temperature operation with performance limited only by quantum noise carried by the incoming signal. Using a model quantum-well infrared photodetector (QWIP), we demonstrated key performance features of our approach. For example, we directly measured the beat frequency signal generated by superimposing local oscillator (LO) light of one frequency and signal light of another through a spectrograph, by injecting the LO light at a laterally displaced input location. In parallel with the development of this novel spectrometer, we modeled a new approach to reducing detector volume though plasmonic resonance effects. Since dark current scales directly with detector volume, this ''photon compression'' can directly lead to lower currents. Our calculations indicate that dark current can be reduced by up to two orders of magnitude in an optimized ''superlens'' structure. Taken together, our spectrometer and dark current reduction strategies provide a promising path toward room temperature operation of a mid-wave and possibly long-wave infrared spectrometer.

  10. Sample spinner for nuclear magnetic resonance spectrometer

    SciTech Connect

    Stejskal, E.O.

    1984-05-01

    A sample spinner for a nuclear magnetic resonance spectrometer having improved operating characteristics is described comprising a rotor supported at both ends by support gas bearings and positioned by a thrust gas bearing. Improved support gas bearings are also described which result in a spinner exhibiting long-term stable operation characteristics.

  11. Exploring the role of ethnic media and the community readiness to combat stigma attached to mental illness among Vietnamese immigrants: the pilot project Tam An (Inner Peace in Vietnamese).

    PubMed

    Han, Meekyung; Cao, Lien; Anton, Karen

    2015-01-01

    Vietnamese Americans are at high risk for developing mental health disorders due to multiple risk factors such as trauma and acculturative stress. However, the utilization of mental health services has been low. The pilot project Tam An was implemented to raise mental health awareness by engaging community resources in the Vietnamese population. Informed by the Community Readiness Model and through local ethnic media sources, messages to destigmatize mental health and promote the willingness to initiate mental health treatment were presented. Using an exploratory perspective, findings from focus group data suggest that the project improved the community's stage of readiness. PMID:24989961

  12. Portable spectrometer monitors inert gas shield in welding process

    NASA Technical Reports Server (NTRS)

    Grove, E. L.

    1967-01-01

    Portable spectrometer using photosensitive readouts, monitors the amount of oxygen and hydrogen in the inert gas shield of a tungsten-inert gas welding process. A fiber optic bundle transmits the light from the welding arc to the spectrometer.

  13. Greenhouse Observations of the Stratosphere and Troposphere (GHOST): a novel shortwave infrared spectrometer developed for the Global Hawk unmanned aerial vehicle

    NASA Astrophysics Data System (ADS)

    Humpage, Neil; Boesch, Hartmut; Palmer, Paul; Parr-Burman, Phil; Vick, Andy; Bezawada, Naidu; Black, Martin; Born, Andy; Pearson, David; Strachan, Jonathan; Wells, Martyn

    2014-05-01

    The tropospheric distribution of greenhouse gases (GHGs) is dependent on surface flux variations, atmospheric chemistry and transport processes over a wide range of spatial and temporal scales. Errors in assumed atmospheric transport can adversely affect surface flux estimates inferred from surface, aircraft or satellite observations of greenhouse gas concentrations using inverse models. We present a novel, compact shortwave infrared spectrometer (GHOST) for installation on the NASA Global Hawk unmanned aerial vehicle to provide tropospheric column observations of CO2, CO, CH4, H2O and HDO over the ocean to address the need for large-scale, simultaneous, finely resolved measurements of key GHGs. These species cover a range of lifetimes and source processes, and measurements of their tropospheric columns will reflect the vertically integrated signal of their vertical and horizontal transport within the troposphere. The primary science objectives of GHOST are to: 1) provide observations which can be used to test atmospheric transport models; 2) validate satellite observations of GHG column observations over oceans, thus filling a critical gap in current validation capabilities; and 3) complement in-situ tropopause transition layer tracer observations from other instrumentation on board the Global Hawk to provide a link between upper and lower troposphere concentration measurements. The GHOST spectrometer system comprises a target acquisition module (TAM), a fibre slicer and feed system, and a multiple order spectrograph. The TAM design utilises a gimbal behind an optical dome, which is programmed to direct solar radiation reflected by the ocean surface into a fibre optic bundle. The fibre slicer and feed system then splits the light into the four spectral bands using order sorting filters. The fibres corresponding to each band are arranged with a small sideways offset to correctly centre each spectrum on the detector array. The spectrograph design is unique in that a

  14. Adapting Raman Spectra from Laboratory Spectrometers to Portable Detection Libraries

    SciTech Connect

    Weatherall, James; Barber, Jeffrey B.; Brauer, Carolyn S.; Johnson, Timothy J.; Su, Yin-Fong; Ball, Christopher D.; Smith, Barry; Cox, Rick; Steinke, Robert; McDaniel, Patricia; Wasserzug, Louis

    2013-02-01

    Raman spectral data collected with high-resolution laboratory spectrometers are processed into a for- mat suitable for importing as a user library on a 1064nm DeltaNu rst generation, eld-deployable spectrometer prototype. The two laboratory systems used are a 1064nm Bruker spectrometer and a 785nm Kaiser spectrometer. The steps taken to compensate for device-dependent spectral resolution, wavenumber shifts between instruments, and wavenumber sensitivity variation are described.

  15. Miniature anastigmatic spectrometer design with a concave toroidal mirror.

    PubMed

    Dong, Jianing; Chen, He; Zhang, Yinchao; Chen, Siying; Guo, Pan

    2016-03-01

    An advanced optical design for a low-cost and astigmatism-corrected spectrometer with a high resolution is presented. The theory and method of astigmatism correction are determined with the use of a concave toroidal mirror. The performances of a modified spectrometer and a traditional spectrometer are compared, and the analysis is verified. Experimentally, the limiting resolution of our spectrometer is 0.1 nm full width at half-maximum, as measured for 579.1 nm.

  16. IR spectrometers for Venus and Mars measurements

    NASA Astrophysics Data System (ADS)

    Drummond, Rachel; Neefs, Eddy; Vandaele, Ann C.

    2012-07-01

    The SOIR spectrometer [1] is an infra-red spectrometer that has performed over 500 solar occultation measurements of the Venus atmosphere, profiling major and minor constituents and studying aerosol absorption, temperature and pressure effects. NOMAD is a 3-channel spectrometer for Mars occultation, limb and nadir measurements. 2 channels are infra-red, the other UV-visible. We will present the technology that enables SOIR and NOMAD to get to parts per billion mixing ratio sensitivities for trace atmospheric components and highlight the improvements made to the SOIR design to enable nadir viewing with NOMAD. Key components include the Acousto-Optical Tunable Filter with radio frequency driver that allows these spectrometers to select the wavelength domain under observation with no need for mechanical moving parts. It also allows background measurements because it is opaque when no RF is applied. The grating with 4 grooves/mm is a very hard to manufacture optical component, and suppliers were very difficult to find. The detector-cooler combination (working at 90K) is from Sofradir/Ricor and the model on board Venus Express is still working after 6 years in space (more on/off cycles that ON hour lifetime problem). The detector MCT mix is slightly altered for nadir observation, in order to reduce thermal background noise and the nadir channel spectrometer is cooled down to 173K by a large V-groove radiator. All the optical components have been enlarged to maximise signal throughput and the slit (that determines spatial and spectral resolution) has also been increased. The spacecraft attitude control system switches from yaw steering for nadir to inertial pointing for solar occultations. 1. Nevejans, D., E. Neefs, E. Van Ransbeeck, S. Berkenbosch, R. Clairquin, L. De Vos, W. Moelans, S. Glorieux, A. Baeke, O. Korablev, I. Vinogradov, Y. Kalinnikov, B. Bach, J.P. Dubois, and E. Villard, Compact high-resolution space-borne echelle grating spectrometer with AOTF based on

  17. Differentially pumped dual linear quadrupole ion trap mass spectrometer

    SciTech Connect

    Owen, Benjamin C.; Kenttamaa, Hilkka I.

    2015-10-20

    The present disclosure provides a new tandem mass spectrometer and methods of using the same for analyzing charged particles. The differentially pumped dual linear quadrupole ion trap mass spectrometer of the present disclose includes a combination of two linear quadrupole (LQIT) mass spectrometers with differentially pumped vacuum chambers.

  18. Nuclear astrophysics studies by SAMURAI spectrometer in RIKEN RIBF

    SciTech Connect

    Yoneda, K.

    2012-11-12

    SAMURAI is a spectrometer which is now being constructed at RIKEN RI Beam Factory. This spectrometer is characterized by a large angular-and momentum-acceptance enabling, for example, multi-particle coincidence measurements. Here brief descriptions of SAMURAI spectrometer and physics topics relevant to nuclear astrophysics are presented.

  19. Fourier and Hadamard transform spectrometers - A limited comparison. II

    NASA Technical Reports Server (NTRS)

    Harwit, M.; Tai, M. H.

    1977-01-01

    A mathematical approach was used to compare interferometric spectrometers and Hadamard transform spectrometers. The principle results are reported, noting that the simple Hadamard spectrometer encodes more efficiently than a Michelson interferometer which, in turn, encodes less efficiently than is usually acknowledged. Hirschfeld's (1977) major objections to these findings are discussed, although it is noted that none of his objections is supported by evidence.

  20. Assembly of the secretion pores GspD, Wza and CsgG into bacterial outer membranes does not require the Omp85 proteins BamA or TamA.

    PubMed

    Dunstan, Rhys A; Hay, Iain D; Wilksch, Jonathan J; Schittenhelm, Ralf B; Purcell, Anthony W; Clark, Joan; Costin, Adam; Ramm, Georg; Strugnell, Richard A; Lithgow, Trevor

    2015-08-01

    In Gram-negative bacteria, β-barrel proteins are integrated into the outer membrane by the β-barrel assembly machinery, with key components of the machinery being the Omp85 family members BamA and TamA. Recent crystal structures and cryo-electron microscopy show a diverse set of secretion pores in Gram-negative bacteria, with α-helix (Wza and GspD) or β-strand (CsgG) transmembrane segments in the outer membrane. We developed assays to measure the assembly of three distinct secretion pores that mediate protein (GspD), curli fibre (CsgG) and capsular polysaccharide (Wza) secretion by bacteria and show that depletion of BamA and TamA does not diminish the assembly of Wza, GspD or CsgG. Like the well characterised pilotins for GspD and other secretins, small periplasmic proteins enhance the assembly of the CsgG β-barrel. We discuss a model for integral protein assembly into the bacterial outer membrane, focusing on the commonalities and differences in the assembly of Wza, GspD and CsgG.

  1. Mass Spectrometers in Deep Space Missions

    NASA Technical Reports Server (NTRS)

    Mahaffy, Paul; Niemann, Hasso; Harpold, Dan

    2002-01-01

    Mass spectrometers have been included in the payloads of several deep space missions over the past three decades. Our laboratory has designed and developed mass spectrometers for the Galileo Probe into the atmosphere of Jupiter, the Pioneer Venus Orbiter, the Cassini Orbiter Mission to Saturn, the Cassini/Huygens Probe Mission to Saturn's moon Titan, the Nozomi Mission to Mars, and most recently the CONTOUR comet nucleus flyby mission. Each mission has required attention to miniaturization, autonomous sampling, and consideration of the special hazards and measurement requirements of the target environment. Development ongoing in our laboratory includes further miniaturization, improved performance in the areas of sensitivity and precision for the important isotope measurements, and adaptation for the unusual environments to be encountered in locations such as the surface or subsurface of Europa or Mars. Various aspects of both the technical implementation of these delivered and planned experiments and the science drivers will be described.

  2. A Mass Spectrometer Simulator in Your Computer

    NASA Astrophysics Data System (ADS)

    Gagnon, Michel

    2012-12-01

    Introduced to study components of ionized gas, the mass spectrometer has evolved into a highly accurate device now used in many undergraduate and research laboratories. Unfortunately, despite their importance in the formation of future scientists, mass spectrometers remain beyond the financial reach of many high schools and colleges. As a result, it is not possible for instructors to take full advantage of this equipment. Therefore, to facilitate accessibility to this tool, we have developed a realistic computer-based simulator. Using this software, students are able to practice their ability to identify the components of the original gas, thereby gaining a better understanding of the underlying physical laws. The software is available as a free download.

  3. A wideband spectrometer for the SRT

    NASA Astrophysics Data System (ADS)

    Comoretto, G.; Natale, V.

    A radiotelescope operating at millimeter wavelengths must be able to analyze an instantaneous bandwidth of at least a few GHz in spectroscopic mode, with a number of spectral points of the order of thousands. Two solutions are examined. In the first, it is assumed that a multi-channel digital spectrometer, with a bandwidth of the order of 100 MHz for each channel, will be available. In this case, a digital filterbank derived from the experience with the ALMA correlator could be used to synthesize a total bandwidth of 1-2 GHz. For wider bandwidths, an acousto-optical spectrometer is proposed. The experience at IRA, Sez. di Firenze with these instruments is presented, and possible solutions are outlined.

  4. A 4 π dilepton spectrometer: PEPSI

    NASA Astrophysics Data System (ADS)

    Buda, A.; Bacelar, J. C. S.; Bałanda, A.; van Klinken, J.; Sujkowski, Z.; van der Woude, A.

    1993-11-01

    A novel positron-electron pair spectroscopy instrument (PEPSI) was designed to measure transitions in the energy region 10-40 MeV. It consists of Nd 2Fe 14B permanent magnets forming a compact 4 π magnetic filter consisting of 12 positron and 20 electron mini-orange-like spectrometers. The response function of PEPSI has been measured with mono-energetic beams of electrons from 5 to 20 MeV. The PEPSI spectrometer was used for measuring the internal pair conversion coefficient ( απ) of the 15.1 MeV M1 transition from a Jπ = 1 + state to the ground state in 12C. Our experimental value of απ = (3.3 ± 0.5) × 10 -3 is in good agreement with theoretical estimates.

  5. Quench anaylsis of MICE spectrometer superconducting solenoid

    SciTech Connect

    Kashikhin, Vladimir; Bross, Alan; Prestemon, Soren; / /LBL, Berkeley

    2011-09-01

    MICE superconducting spectrometer solenoids fabrication and tests are in progress now. First tests of the Spectrometer Solenoid discovered some issues which could be related to the chosen passive quench protection system. Both solenoids do not have heaters and quench propagation relied on the 'quench back' effect, cold diodes, and shunt resistors. The solenoids have very large inductances and stored energy which is 100% dissipated in the cold mass during a quench. This makes their protection a challenging task. The paper presents the quench analysis of these solenoids based on 3D FEA solution of coupled transient electromagnetic and thermal problems. The simulations used the Vector Fields QUENCH code. It is shown that in some quench scenarios, the quench propagation is relatively slow and some areas can be overheated. They describe ways of improving the solenoids quench protection in order to reduce the risk of possible failure.

  6. High-resolving mass spectrographs and spectrometers

    NASA Astrophysics Data System (ADS)

    Wollnik, Hermann

    2015-11-01

    Discussed are different types of high resolving mass spectrographs and spectrometers. In detail outlined are (1) magnetic and electric sector field mass spectrographs, which are the oldest systems, (2) Penning Trap mass spectrographs and spectrometers, which have achieved very high mass-resolving powers, but are technically demanding (3) time-of-flight mass spectrographs using high energy ions passing through accelerator rings, which have also achieved very high mass-resolving powers and are equally technically demanding, (4) linear time-of-flight mass spectrographs, which have become the most versatile mass analyzers for low energy ions, while the even higher performing multi-pass systems have only started to be used, (5) orbitraps, which also have achieved remarkably high mass-resolving powers for low energy ions.

  7. A photoacoustic spectrometer for trace gas detection

    NASA Astrophysics Data System (ADS)

    Telles, E. M.; Bezerra, E.; Scalabrin, A.

    2005-06-01

    A high-resolution external laser photoacoustic spectrometer has been developed for trace gas detection with absorption transitions in coincidence with CO2 laser emission lines (9,2-10,9 μm: 920-1086 cm-1). The CO2 laser operates in 90 CW lines with power of up to 15 W. A PC-controlled step motor can tune the laser lines. The resonance frequency of first longitudinal mode of the photoacoustic cell is at 1600 Hz. The cell Q-factor and cell constant are measured close to 50 and 28 mVcmW-1, respectively. The spectrometer has been tested in preliminary studies to analyze the absorption transitions of ozone (O_3). The ethylene (C_2H_4) from papaya fruit is also investigated using N2 as carrier gas at a constant flow rate.

  8. Improved cold-neutron prompt gamma spectrometer

    SciTech Connect

    Lindstrom, R.M.; Paul, R.L.; Heald, A.E.; Langland, J.K.

    1996-12-31

    The cold-neutron prompt-gamma activation analysis (PGAA) spectrometer at the National Institute of Standard and Technology (NIST) has been rebuilt to take advantage of the newly installed LH{sub 2} cold neutron source at the NIST reactor. The new source, a 32-cm-o.d., 2-cm-thick spherical shell of liquid hydrogen, produces a higher neutron density at longer wave-length than did the D{sub 2}O ice source that has been in use since 1987. At the PGAA spectrometer, located 41 m from the cold source on neutron guide NG7, the effective neutron fluence rate (using s, = 98.6 b for gold) was measured to be 8 x 10{sup 8} cm{sup -2}{center_dot}s{sup -1}, a factor of 3 higher at the same reactor power (20 MW) than before.

  9. Neutron spectrometer for improved SNM search.

    SciTech Connect

    Vance, Andrew L.; Aigeldinger, Georg

    2007-03-01

    With the exception of large laboratory devices with very low sensitivities, a neutron spectrometer have not been built for fission neutrons such as those emitted by special nuclear materials (SNM). The goal of this work was to use a technique known as Capture Gated Neutron Spectrometry to develop a solid-state device with this functionality. This required modifications to trans-stilbene, a known solid-state scintillator. To provide a neutron capture signal we added lithium to this material. This unique triggering signal allowed identification of neutrons that lose all of their energy in the detector, eliminating uncertainties that arise due to partial energy depositions. We successfully implemented a capture gated neutron spectrometer and were able to distinguish an SNM like fission spectrum from a spectrum stemming from a benign neutron source.

  10. The transition-edge EBIT microcalorimeter spectrometer

    NASA Astrophysics Data System (ADS)

    Betancourt-Martinez, Gabriele L.; Adams, Joseph; Bandler, Simon; Beiersdorfer, Peter; Brown, Gregory; Chervenak, James; Doriese, Randy; Eckart, Megan; Irwin, Kent; Kelley, Richard; Kilbourne, Caroline; Leutenegger, Maurice; Porter, F. S.; Reintsema, Carl; Smith, Stephen; Ullom, Joel

    2014-07-01

    The Transition-edge EBIT Microcalorimeter Spectrometer (TEMS) is a 1000-pixel array instrument to be delivered to the Electron Beam Ion Trap (EBIT) facility at the Lawrence Livermore National Laboratory (LLNL) in 2015. It will be the first fully operational array of its kind. The TEMS will utilize the unique capabilities of the EBIT to verify and benchmark atomic theory that is critical for the analysis of high-resolution data from microcalorimeter spectrometers aboard the next generation of x-ray observatories. We present spectra from the present instrumentation at EBIT, as well as our latest results with time-division multiplexing using the current iteration of the TEMS focal plane assembly in our test platform at NASA/GSFC.

  11. O using QCL spectrometer for combustion applications

    NASA Astrophysics Data System (ADS)

    Hieta, T.; Merimaa, M.

    2014-12-01

    We demonstrate a high-sensitivity laser-based spectrometer for simultaneous detection of sulphur dioxide (SO2) sulphur trioxide (SO3) and water for coal-fired combustion applications. The spectrometer is based on a quantum-cascade laser (QCL) operating at 7.16 μm, capable of measuring all three components simultaneously in a single frequency sweep. An optical multipass cell having a total path length of 9.1 m is used at increased temperature and at low pressure to ensure reliable measurement of highly reactive SO3 and adequate separation of overlapping spectral features, respectively. Detection limits for SO2 and SO3 are 0.134 and 0.0073 ppm, respectively, when employing a 20-s sampling time.

  12. Data analysis for Skylab proton spectrometer

    NASA Technical Reports Server (NTRS)

    Hill, C. W.

    1976-01-01

    The data from a proton spectrometer flown aboard Skylab is examined. The instrument is sensitive to protons in the energy range 18 to 400 MeV. A partial failure of the spectrometer restricted spectral analysis to two energy bands, 18 to 27 MeV and 27 to 400 MeV. The directional data showed that a Gaussian angular distribution parameter of at least 70 degrees is required for the low energy band and at least 40 degrees for the high energy band. The data, integrated over angle, indicate that the AP3 model extrapolated down to 18-27 MeV is high by factors of 2 to 5 over most of the B-L space mapped. In the 27 to 400 MeV range, the AP3 model is 20 to 100 percent low at low and high values of L, and is high at medium L values in the B-L space mapped.

  13. Associated Particle Tagging (APT) in Magnetic Spectrometers

    SciTech Connect

    Jordan, David V.; Baciak, James E.; Stave, Sean C.; Chichester, David; Dale, Daniel; Kim, Yujong; Harmon, Frank

    2012-10-16

    Summary In Brief The Associated Particle Tagging (APT) project, a collaboration of Pacific Northwest National Laboratory (PNNL), Idaho National Laboratory (INL) and the Idaho State University (ISU)/Idaho Accelerator Center (IAC), has completed an exploratory study to assess the role of magnetic spectrometers as the linchpin technology in next-generation tagged-neutron and tagged-photon active interrogation (AI). The computational study considered two principle concepts: (1) the application of a solenoidal alpha-particle spectrometer to a next-generation, large-emittance neutron generator for use in the associated particle imaging technique, and (2) the application of tagged photon beams to the detection of fissile material via active interrogation. In both cases, a magnetic spectrometer momentum-analyzes charged particles (in the neutron case, alpha particles accompanying neutron generation in the D-T reaction; in the tagged photon case, post-bremsstrahlung electrons) to define kinematic properties of the relevant neutral interrogation probe particle (i.e. neutron or photon). The main conclusions of the study can be briefly summarized as follows: Neutron generator: • For the solenoidal spectrometer concept, magnetic field strengths of order 1 Tesla or greater are required to keep the transverse size of the spectrometer smaller than 1 meter. The notional magnetic spectrometer design evaluated in this feasibility study uses a 5-T magnetic field and a borehole radius of 18 cm. • The design shows a potential for 4.5 Sr tagged neutron solid angle, a factor of 4.5 larger than achievable with current API neutron-generator designs. • The potential angular resolution for such a tagged neutron beam can be less than 0.5o for modest Si-detector position resolution (3 mm). Further improvement in angular resolution can be made by using Si-detectors with better position resolution. • The report documents several features of a notional generator design incorporating the

  14. Portable gas chromatograph-mass spectrometer

    DOEpatents

    Andresen, Brian D.; Eckels, Joel D.; Kimmons, James F.; Myers, David W.

    1996-01-01

    A gas chromatograph-mass spectrometer (GC-MS) for use as a field portable organic chemical analysis instrument. The GC-MS is designed to be contained in a standard size suitcase, weighs less than 70 pounds, and requires less than 600 watts of electrical power at peak power (all systems on). The GC-MS includes: a conduction heated, forced air cooled small bore capillary gas chromatograph, a small injector assembly, a self-contained ion/sorption pump vacuum system, a hydrogen supply, a dual computer system used to control the hardware and acquire spectrum data, and operational software used to control the pumping system and the gas chromatograph. This instrument incorporates a modified commercial quadrupole mass spectrometer to achieve the instrument sensitivity and mass resolution characteristic of laboratory bench top units.

  15. Imaging spectrometer wide field catadioptric design

    DOEpatents

    Chrisp; Michael P.

    2008-08-19

    A wide field catadioptric imaging spectrometer with an immersive diffraction grating that compensates optical distortions. The catadioptric design has zero Petzval field curvature. The imaging spectrometer comprises an entrance slit for transmitting light, a system with a catadioptric lens and a dioptric lens for receiving the light and directing the light, an immersion grating, and a detector array. The entrance slit, the system for receiving the light, the immersion grating, and the detector array are positioned wherein the entrance slit transmits light to the system for receiving the light and the system for receiving the light directs the light to the immersion grating and the immersion grating receives the light and directs the light through the system for receiving the light to the detector array.

  16. Portable gas chromatograph-mass spectrometer

    DOEpatents

    Andresen, B.D.; Eckels, J.D.; Kimmons, J.F.; Myers, D.W.

    1996-06-11

    A gas chromatograph-mass spectrometer (GC-MS) is described for use as a field portable organic chemical analysis instrument. The GC-MS is designed to be contained in a standard size suitcase, weighs less than 70 pounds, and requires less than 600 watts of electrical power at peak power (all systems on). The GC-MS includes: a conduction heated, forced air cooled small bore capillary gas chromatograph, a small injector assembly, a self-contained ion/sorption pump vacuum system, a hydrogen supply, a dual computer system used to control the hardware and acquire spectrum data, and operational software used to control the pumping system and the gas chromatograph. This instrument incorporates a modified commercial quadrupole mass spectrometer to achieve the instrument sensitivity and mass resolution characteristic of laboratory bench top units. 4 figs.

  17. Compact imaging spectrometer utilizing immersed gratings

    DOEpatents

    Chrisp, Michael P.; Lerner, Scott A.; Kuzmenko, Paul J.; Bennett, Charles L.

    2007-07-03

    A compact imaging spectrometer with an immersive diffraction grating that compensates optical distortions. The imaging spectrometer comprises an entrance slit for transmitting light, means for receiving the light and directing the light, an immersion grating, and a detector array. The entrance slit, the means for receiving the light, the immersion grating, and the detector array are positioned wherein the entrance slit transmits light to the means for receiving the light and the means for receiving the light directs the light to the immersion grating and the immersion grating receives the light and directs the light to the means for receiving the light, and the means for receiving the light directs the light to the detector array.

  18. Interface for liquid chromatograph-mass spectrometer

    DOEpatents

    Andresen, B.D.; Fought, E.R.

    1989-09-19

    A moving belt interface is described for real-time, high-performance liquid chromatograph (HPLC)/mass spectrometer (MS) analysis which strips away the HPLC solvent as it emerges from the end of the HPLC column and leaves a residue suitable for mass-spectral analysis. The interface includes a portable, stand-alone apparatus having a plural stage vacuum station, a continuous ribbon or belt, a drive train magnetically coupled to an external drive motor, a calibrated HPLC delivery system, a heated probe tip and means located adjacent the probe tip for direct ionization of the residue on the belt. The interface is also capable of being readily adapted to fit any mass spectrometer. 8 figs.

  19. Interface for liquid chromatograph-mass spectrometer

    DOEpatents

    Andresen, Brian D.; Fought, Eric R.

    1989-01-01

    A moving belt interface for real-time, high-performance liquid chromatograph (HPLC)/mass spectrometer (MS) analysis which strips away the HPLC solvent as it emerges from the end of the HPLC column and leaves a residue suitable for mass-spectral analysis. The interface includes a portable, stand-alone apparatus having a plural stage vacuum station, a continuous ribbon or belt, a drive train magnetically coupled to an external drive motor, a calibrated HPLC delivery system, a heated probe tip and means located adjacent the probe tip for direct ionization of the residue on the belt. The interface is also capable of being readily adapted to fit any mass spectrometer.

  20. Portable gas chromatograph-mass spectrometer

    SciTech Connect

    Andresen, B.D.; Eckels, J.D.; Kimmins, J.F.; Myers, D.W.

    1994-12-31

    A gas chromatograph-mass spectrometer (GC-MS) for use as a field portable organic chemical analysis instrument. The GC-MS is designed to be contained in a standard size suitcase, weighs less than 70 pounds, and requires less than 600 watts of electrical power at peak power (all systems on). The GC-MS includes: a conduction heated, forced air cooled small bore capillary gas chromatograph, a small injector assembly, a self-contained ion/sorption pump vacuum system, a hydrogen supply, a dual computer system used to control the hardware and acquire spectrum data, and operational software used to control the pumping system and the gas chromatograph. This instrument incorporates a modified commercial quadrupole mass spectrometer to achieve the instrument sensitivity and mass resolution characteristic of laboratory bench top units.

  1. Solar maximum ultraviolet spectrometer and polarimeter

    NASA Technical Reports Server (NTRS)

    Tandberg-Hanssen, E.; Woodgate, B. E.; Brandt, J. C.; Chapman, R. D.; Hyder, C. L.; Michalitsianos, A. G.; Shine, R. A.; Athay, R. G.; Beckers, J. M.; Bruner, E. C.

    1979-01-01

    The objectives of the UVSP experiment are to study solar ultraviolet radiations, particularly from flares and active regions, and to measure constituents in the terrestrial atmosphere by the extinction of sunlight at satellite dawn and dusk. The instrument is designed to observe the Sun at a variety of spectral and spatial resolutions in the range from 1150 to 3600 A. A Gregorian telescope with effective focal length of 1.8 m is used to feed a 1 m Ebert-Fastie spectrometer. A polarimeter containing rotatable magnesium fluoride waveplates is included behind the spectrometer entrance slit and will allow all four Stokes parameters to be determined. Velocities on the Sun can also be measured. The instrument is controlled by a computer which can interact with the data stream to modify the observing program. The observing modes, including rasters, spectral scans, velocity measurements, and polarimetry, are also described along with plans for mission operations, data handling, and analysis of the observations.

  2. Mapping Imaging Spectrometer for Europa (MISE)

    NASA Astrophysics Data System (ADS)

    Blaney, D. L.; Clark, R. N.; Dalton, J. B.; Davies, A. G.; Green, R. O.; Hedman, M. M.; Hibbits, C. A.; Langevin, Y. J.; Lunine, J. I.; McCord, T. B.; Soderblom, J. M.; Cable, M. L.; Mouroulis, P.; Kim, W.; Dorsky, L. I.; Strohbehn, K.

    2015-10-01

    The Mapping Imaging Spectrometer for Europa(MISE) instrument is designed to be able to unravel the composition of Europa, and to provide new insight into the processes that have in the past and continue to shape Europa, and on the habitability of Europa's ocean. The MISE design is the result of collaboration between NASA's Jet Propulsion Laboratory (California Institute of Technology) and the Applied Physics Laboratory (John Hopkins' University). JPL's Discovery Moon Mineralogy Mapper (M3) on Chandrayan-1 and APL's Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) comprise the technical basis for MISE. Internal JPL and APL investments in conjunction with NASA support under the ICEE program has allowed for instrument technology development and testing to achieve a design which would perform in Europa's radiation environment and meet potential sterilization requirements due to planetary protection.

  3. Pioneer Venus large probe neutral mass spectrometer

    NASA Technical Reports Server (NTRS)

    Hoffman, J.

    1982-01-01

    The deuterium hydrogen abundance ratio in the Venus atmosphere was measured while the inlets to the Pioneer Venus large probe mass spectrometer were coated with sulfuric acid from Venus' clouds. The ratio is (1.6 + or - 0.2) x 10 to the minus two power. It was found that the 100 fold enrichment of deuterium means that Venus outgassed at least 0.3% of a terrestrial ocean and possibly more.

  4. Water Mass Map from Neutron Spectrometer

    NASA Technical Reports Server (NTRS)

    2003-01-01

    December 8, 2003

    This map shows the estimated lower limit of the water content of the upper meter of Martian soil. The estimates are derived from the hydrogen abundance measured by the neutron spectrometer component of the gamma ray spectrometer suite on NASA's Mars Odyssey spacecraft.

    The highest water-mass fractions, exceeding 30 percent to well over 60 percent, are in the polar regions, beyond about 60 degrees latitude north or south. Farther from the poles, significant concentrations are in the area bound in longitude by minus 10 degrees to 50 degrees and in latitude by 30 degrees south to 40 degrees north, and in an area to the south and west of Olympus Mons (30 degrees to 0 degrees south latitude and minus 135 degrees to 110 degrees longitude).

    NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the 2001 Mars Odyssey mission for the NASA Office of Space Science in Washington. Investigators at Arizona State University in Tempe, the University of Arizona in Tucson and NASA's Johnson Space Center, Houston, operate the science instruments. The gamma-ray spectrometer was provided by the University of Arizona in collaboration with the Russian Aviation and Space Agency, which provided the high-energy neutron detector, and the Los Alamos National Laboratories, New Mexico, which provided the neutron spectrometer. Lockheed Martin Space Systems, Denver, is the prime contractor for the project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL.

  5. Scanning imaging absorption spectrometer for atmospheric chartography

    NASA Technical Reports Server (NTRS)

    Burrows, John P.; Chance, Kelly V.

    1991-01-01

    The SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY is an instrument which measures backscattered, reflected, and transmitted light from the earth's atmosphere and surface. SCIAMACHY has eight spectral channels which observe simultaneously the spectral region between 240 and 1700 nm and selected windows between 1940 and 2400 nm. Each spectral channel contains a grating and linear diode array detector. SCIAMACHY observes the atmosphere in nadir, limb, and solar and lunar occultation viewing geometries.

  6. Capillary zone electrophoresis-mass spectrometer interface

    DOEpatents

    D'Silva, Arthur

    1996-08-06

    A device for providing equal electrical potential between two loci unconnected by solid or liquid electrical conducts is provided. The device comprises a first electrical conducting terminal, a second electrical conducting terminal connected to the first terminal by a rigid dielectric structure, and an electrically conducting gas contacting the first and second terminals. This device is particularly suitable for application in the electrospray ionization interface between a capillary zone electrophoresis apparatus and a mass spectrometer.

  7. Capillary zone electrophoresis-mass spectrometer interface

    DOEpatents

    D`Silva, A.

    1996-08-06

    A device for providing equal electrical potential between two loci unconnected by solid or liquid electrical conductors is provided. The device comprises a first electrical conducting terminal, a second electrical conducting terminal connected to the first terminal by a rigid dielectric structure, and an electrically conducting gas contacting the first and second terminals. This device is particularly suitable for application in the electrospray ionization interface between a capillary zone electrophoresis apparatus and a mass spectrometer. 1 fig.

  8. Midrapidity measurements with the BRAHMS spectrometer

    SciTech Connect

    Beavis, D.

    1995-07-15

    The forward- and midrapidity-arms of the BRAHMS experiment are designed to measure charged particle production over a wide range of transverse momentum for rapidities, 0{le}y{le}4. Details of the midrapidity spectrometer, which provides coverage for 0{le}{eta}{le}1.3, are presented here. The capabilities for inclusive {pi}{sup +-}, K{sup +-}, and p{sup +-} measurements and boson pair correlations are discussed.

  9. Spectrometer of high energy gamma quantums

    NASA Technical Reports Server (NTRS)

    Blokhintsev, I. D.; Melioranskiy, A. S.; Kalinkin, L. F.; Nagornykh, Y. I.; Pryakhin, Y. A.

    1979-01-01

    A detailed description of the apparatus GG-2M is given. The spectrometer contains a Cerenkov and scintillation (including anticoincidence) counter. The energies of the gamma quantums are measured by a shower calorimeter, in which scintillation counters are used in the capacity of detectors. Results are given for tuning the device on mu-mesons of cosmic rays. The data of physical tuning allow more reliable interpretation of the results of measurements which are received on the satellites.

  10. A diffuse soft X-ray spectrometer

    NASA Technical Reports Server (NTRS)

    Mccammon, D.

    1981-01-01

    A design for a diffuse X-ray spectrometer utilizing Bragg reflection is described. The geometry has a very high throughput for a given physical size and allows simultaneous observation at all wavelengths within its range. Spectral resolving power is about 35 to 50. A similar unit equipped with thallium acid pthallate crystals will cover the 11 - 24 A-range with about half this throughput and twice the resolving power.

  11. STS-54 Diffuse X-Ray Spectrometer

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Louis Kaluzienski, Program Scientist, Wilton T. Sanders, Principal Investigator, and Chris Dunker, Diffuse X-Ray Spectrometer (DXS) Mission Manager, each give an overview of the DXS, including the purpose of the DXS, a brief description of x-ray astronomy, the scientific objectives of the DXS, and information on the STS-54 Endeavour mission, in which the DXS is part of the payload. The men then answer questions from the press.

  12. Time Dispersive Spectrometer Using Digital Switching Means

    DOEpatents

    Tarver, III, Edward E.; Siems, William F.

    2004-09-07

    Methods and apparatus are described for time dispersive spectroscopy. In particular, a modulated flow of ionized molecules of a sample are introduced into a drift region of an ion spectrometer. The ions are subsequently detected by an ion detector to produce an ion detection signal. The ion detection signal can be modulated to obtain a signal useful in assaying the chemical constituents of the sample.

  13. Frequency-feedback cavity enhanced spectrometer

    SciTech Connect

    Hovde, David Christian; Gomez, Anthony

    2015-08-18

    A spectrometer comprising an optical cavity, a light source capable of producing light at one or more wavelengths transmitted by the cavity and with the light directed at the cavity, a detector and optics positioned to collect light transmitted by the cavity, feedback electronics causing oscillation of amplitude of the optical signal on the detector at a frequency that depends on cavity losses, and a sensor measuring the oscillation frequency to determine the cavity losses.

  14. Design of a portable microfiber optic spectrometer

    NASA Astrophysics Data System (ADS)

    Tong, Jian-ping; Yang, Yang; Sui, Cheng-hua; Xu, Dang-yang; Wang, fei

    2010-10-01

    Spectrum examination is widely used in scientific research and production. With the development of scientific research and production, the trend of spectrum examination is from indoor to outdoor in situ examination and on-line monitor. So the spectrometer is required to be more minimal. A new type of portable micro fiber spectrometer, using CCD, blaze grating, and two spherical mirror, a small dispersing system based on crossing Czerny-Turner structure, is designed based on this kind of requirement. By analyzing optical system structure, the relation among parameters of these components has been found out in order to fix basic parameters for miniaturized spectrometer; its working wavelength is 200-910nm. The entire spectrum is detected by a CCD for one time, the selection of CCD is product of Toshiba Corporation, linear charge coupled device (L.CCD) TCD1304AP, then received light signal is converted to an electrical signal. The system's hardware circuit includes CPLD, MCU, the CCD driving timing circuit, signal conditioning circuits, high-speed A/D sampling and transform timing circuit. A new kind of driving and sampling system which is high integrated for multi-channel has been designed by using CPLD (complex programmable logical device) and MCU. In this system, many function modules can be generated by logic cells inside of the CPLD chip, such as the driving pulse of CCD, the driving timing of high-speed A/D sampling converter and storage system and so on. In the end, the A/D results can be transmitted to computer by MCU for storage, processing and analysis. The CPLD is programmed in VHDL and compiled, synthesized, simulated and burned with the helping of the environment of Quartus II. The design of portable micro fiber spectrometer has the feature of wide spectrum range and high resolving power, so the system is especially suitable in the application of portable filed examination.

  15. Miniature transmissive DLP-based infrared spectrometer

    NASA Astrophysics Data System (ADS)

    Koudsi, Badia; Refai, Hakki

    2016-02-01

    Spectroscopic measurements have the potential to positively impact a wide range of research, development, monitoring and control applications. In many cases, this potential is not realized because the spectrometer cannot be brought out of the laboratory to the measurement site due to sensitivities to environmental factors, highly accurate data cannot be obtained in a timely manner, or customizing the spectrometer to a specific application is costly and precludes re-use of the device for other application once its original purpose is served. We present the development of a DLP-based spectroscopic system in the near-infrared that is low-cost, compact and rugged, provides high resolution and is highly adaptable through straightforward software control. The key elements of the design include an efficient and compact optical pathway, a high-resolution DMD controlled by a fast DLP board, and a user-friendly, feature-rich software package that facilitates system configuration and data analysis. The DMD replaces the detector array in traditional spectrometers, and is shown to provide greater functionality while eliminating the need for mechanical scanning. We demonstrate how the long, thin columns of mirrors in the DMD provide high wavelength selectivity and capture more light at each wavelength, increasing measurement SNR. Selectively activating columns of mirrors is shown to adaptively tailor the resolution and the wavelengths collected and analyzed by the system allow one device to meet the needs of many different applications and to reduce measurement times. The software interface developed for accessing the many features of the spectrometer is discussed.

  16. Silicon Microleaks for Inlets of Mass Spectrometers

    NASA Technical Reports Server (NTRS)

    Harpold, Dan; Hasso, Niemann; Jamieson, Brian G.; Lynch, Bernard A.

    2009-01-01

    Microleaks for inlets of mass spectrometers used to analyze atmospheric gases can be fabricated in silicon wafers by means of photolithography, etching, and other techniques that are commonly used in the manufacture of integrated circuits and microelectromechanical systems. The microleaks serve to limit the flows of the gases into the mass-spectrometer vacuums to specified very small flow rates consistent with the capacities of the spectrometer vacuum pumps. There is a need to be able to precisely tailor the dimensions of each microleak so as to tailor its conductance to a precise low value. (As used here, "conductance" signifies the ratio between the rate of flow in the leak and the pressure drop from the upstream to the downstream end of the leak.) To date, microleaks have been made, variously, of crimped metal tubes, pulled glass tubes, or frits. Crimped-metal and pulled-glass-tube microleaks cannot readily be fabricated repeatably to precise dimensions and are susceptible to clogging with droplets or particles. Frits tend to be differentially chemically reactive with various gas constituents and, hence, to distort the gas mixtures to be analyzed. The present approach involving microfabrication in silicon largely overcomes the disadvantages of the prior approaches.

  17. MERTIS: a highly integrated IR imaging spectrometer

    NASA Astrophysics Data System (ADS)

    Walter, I.; Hirsch, H.; Jahn, H.; Knollenberg, J.; Venus, H.

    2006-08-01

    With a background of several instrument developments in the past the German Aerospace Center in Berlin proposed for ESA's deep space mission BepiColombo an imaging spectrometer which meets the challenges of limited technical resources and a very special operational environment. An 80-channel push broom-type spectrometer has been drafted and it s development has been started under the name MERTIS (MErcury Radiometer and Thermal Infrared Spectrometer). The instrument is dedicated to the mineralogy surface science and thermal characteristics studies of the innermost planet. It is based on modern un-cooled micro-bolometer technology and all-reflective optics design. The operation concept principle is characterised by intermediate scanning of the planet, deep space and black bodies as calibration targets. A miniaturised radiometer is included for low level temperature measurements. Altogether the system shall fit into a CD-package sized cube and weigh less than 3 kg. The paper will present the instrument architecture of MERTIS, its design status and will show the results of first components being built.

  18. Expert overseer for mass spectrometer system

    DOEpatents

    Filby, Evan E.; Rankin, Richard A.

    1991-01-01

    An expert overseer for the operation and real-time management of a mass spectrometer and associated laboratory equipment. The overseer is a computer-based expert diagnostic system implemented on a computer separate from the dedicated computer used to control the mass spectrometer and produce the analysis results. An interface links the overseer to components of the mass spectrometer, components of the laboratory support system, and the dedicated control computer. Periodically, the overseer polls these devices and as well as itself. These data are fed into an expert portion of the system for real-time evaluation. A knowledge base used for the evaluation includes both heuristic rules and precise operation parameters. The overseer also compares current readings to a long-term database to detect any developing trends using a combination of statistical and heuristic rules to evaluate the results. The overseer has the capability to alert lab personnel whenever questionable readings or trends are observed and provide a background review of the problem and suggest root causes and potential solutions, or appropriate additional tests that could be performed. The overseer can change the sequence or frequency of the polling to respond to an observation in the current data.

  19. The compact neutron spectrometer at ASDEX Upgrade

    SciTech Connect

    Giacomelli, L.; Zimbal, A.; Tittelmeier, K.; Schuhmacher, H.; Tardini, G.; Neu, R.; Collaboration: ASDEX Upgrade Team

    2011-12-15

    The first neutron spectrometer of ASDEX Upgrade (AUG) was installed in November 2008. It is a compact neutron spectrometer (CNS) based on a BC501A liquid scintillating detector, which can simultaneously measure 2.45-MeV and 14-MeV neutrons emitted from deuterium (D) plasmas and {gamma} radiation. The scintillating detector is coupled to a digital pulse shape discrimination data acquisition (DPSD) system capable of count rates up to 10{sup 6} s{sup -1}. The DPSD system can operate in acquisition and processing mode. With the latter n-{gamma} discrimination is performed off-line based on the two-gate method. The paper describes the tests of the CNS and its installation at AUG. The neutron emission from the D plasma measured during a discharge with high auxiliary heating power was used to validate the CNS performance. The study of the optimal settings for the DPSD data processing to maximize the n-{gamma} discrimination capability of the CNS is reported. The CNS measured both 2.45-MeV and 14-MeV neutrons emitted in AUG D plasmas with a maximum count rate of 5.4 x10{sup 5} s{sup -1} (>10 times higher than similar spectrometers previously achieved) with an efficiency of 9.3 x 10{sup -10} events per AUG neutron.

  20. Modular reconfigurable matched spectral filter spectrometer

    NASA Astrophysics Data System (ADS)

    Schundler, Elizabeth; Engel, James R.; Gruber, Thomas; Vaillancourt, Robert; Benedict-Gill, Ryan; Mansur, David J.; Dixon, John; Potter, Kevin; Newbry, Scott

    2015-06-01

    OPTRA is currently developing a modular, reconfigurable matched spectral filter (RMSF) spectrometer for the monitoring of greenhouse gases. The heart of this spectrometer will be the RMSF core, which is a dispersive spectrometer that images the sample spectrum from 2000 - 3333 cm-1 onto a digital micro-mirror device (DMD) such that different columns correspond to different wavebands. By applying masks to this DMD, a matched spectral filter can be applied in hardware. The core can then be paired with different fore-optics or detector modules to achieve active in situ or passive remote detection of the chemicals of interest. This results in a highly flexible system that can address a wide variety of chemicals by updating the DMD masks and a wide variety of applications by swapping out fore-optic and detector modules. In either configuration, the signal on the detector is effectively a dot-product between the applied mask and the sample spectrum that can be used to make detection and quantification determinations. Using this approach significantly reduces the required data bandwidth of the sensor without reducing the information content, therefore making it ideal for remote, unattended systems. This paper will focus on the design of the RMSF core.

  1. Prismatic analyser concept for neutron spectrometers

    SciTech Connect

    Birk, Jonas O.; Jacobsen, Johan; Hansen, Rasmus L.; Lefmann, Kim; Markó, Márton; Niedermayer, Christof; Freeman, Paul G.; Christensen, Niels B.; Månsson, Martin; Rønnow, Henrik M.

    2014-11-15

    Developments in modern neutron spectroscopy have led to typical sample sizes decreasing from few cm to several mm in diameter samples. We demonstrate how small samples together with the right choice of analyser and detector components makes distance collimation an important concept in crystal analyser spectrometers. We further show that this opens new possibilities where neutrons with different energies are reflected by the same analyser but counted in different detectors, thus improving both energy resolution and total count rate compared to conventional spectrometers. The technique can readily be combined with advanced focussing geometries and with multiplexing instrument designs. We present a combination of simulations and data showing three different energies simultaneously reflected from one analyser. Experiments were performed on a cold triple axis instrument and on a prototype inverse geometry Time-of-flight spectrometer installed at PSI, Switzerland, and shows excellent agreement with the predictions. Typical improvements will be 2.0 times finer resolution and a factor of 1.9 in flux gain compared to a focussing Rowland geometry, or of 3.3 times finer resolution and a factor of 2.4 in flux gain compared to a single flat analyser slab.

  2. ScanSpec: an imaging FTIR spectrometer

    NASA Astrophysics Data System (ADS)

    Nelsson, Claes; Lundberg, Frans; Nilsson, Paer; Berglund, Mattias

    2000-07-01

    The demand for hyperspectral imagers for research has increased in order to match the performance of new sensors for military applications. These work in several spectral bands and targets and backgrounds need to be characterized both spatially and spectrally to enable efficient signature analysis. Another task for a hyperspectral research imager is to acquire hyperspectral data to be able to study new hyperspectral signal processing techniques to detect, classify, and identify targets. This paper describes how a hyperspectral IR imager was developed based on an FTIR spectrometer at the Defence Research Establishment (FOA) in Linkoping, Sweden. The system, called ScanSpec, consists of a fast FTIR spectrometer from Bomem (MR254), an image-scanning mirror device with controlling electronics, and software for data collection and image forming. The spectrometer itself has not been modified. The paper also contains a performance evaluation with NESR NEDT, and MRTD analysis. Finally, some examples of hyperspectral results from field trials are presented: maritime background and remote gas detection.

  3. Imaging spectrometer for fugitive gas leak detection

    NASA Astrophysics Data System (ADS)

    Hinnrichs, Michele

    1999-12-01

    Under contract to the U.S. Air Force and Navy, Pacific Advanced Technology has developed a very sensitive infrared imaging spectrometer that can perform remote imaging and spectro-radiometry. One of the most exciting applications for this technology is in the remote monitoring of smoke stack emissions and fugitive leaks. To date remote continuous emission monitoring (CEM) systems have not been approved by the EPA, however, they are under consideration. If the remote sensing technology is available with the sensitivity to monitor emission at the required levels and man portable it can reduce the cost and improve the reliability of performing such measurements. Pacific Advanced Technology (PAT) believes that it currently has this technology available to industry. This paper will present results from a field test where gas vapors during a refueling process were imaged and identified. In addition images of propane from a leaking stove will be presented. We at PAT have developed a real time image processing board that enhances the signal to noise ratio of low contrast gases and makes them easily viewable using the Image Multispectral Sensing (IMSS) imaging spectrometer. The IMSS imaging spectrometer is the size of a camcorder. Currently the data is stored in a Notebook computer thus allowing the system to be easily carried into power plants to look for fugitive leaks. In the future the IMSS will have an embedded processor and DSP and will be able to transfer data over an Ethernet link.

  4. Compact high performance spectrometers using computational imaging

    NASA Astrophysics Data System (ADS)

    Morton, Kenneth; Weisberg, Arel

    2016-05-01

    Compressive sensing technology can theoretically be used to develop low cost compact spectrometers with the performance of larger and more expensive systems. Indeed, compressive sensing for spectroscopic systems has been previously demonstrated using coded aperture techniques, wherein a mask is placed between the grating and a charge coupled device (CCD) and multiple measurements are collected with different masks. Although proven effective for some spectroscopic sensing paradigms (e.g. Raman), this approach requires that the signal being measured is static between shots (low noise and minimal signal fluctuation). Many spectroscopic techniques applicable to remote sensing are inherently noisy and thus coded aperture compressed sensing will likely not be effective. This work explores an alternative approach to compressed sensing that allows for reconstruction of a high resolution spectrum in sensing paradigms featuring significant signal fluctuations between measurements. This is accomplished through relatively minor changes to the spectrometer hardware together with custom super-resolution algorithms. Current results indicate that a potential overall reduction in CCD size of up to a factor of 4 can be attained without a loss of resolution. This reduction can result in significant improvements in cost, size, and weight of spectrometers incorporating the technology.

  5. Multislit optimized spectrometer: fabrication and assembly update

    NASA Astrophysics Data System (ADS)

    Valle, Tim; Hardesty, Chuck; Good, William; Seckar, Chris; Shea, Don; Spuhler, Peter; Davis, Curtiss O.; Tufillaro, Nicholas

    2013-09-01

    The NASA ESTO funded Multi-slit Optimized Spectrometer (MOS) Instrument Incubator Program will advance a spatial multiplexing spectrometer for coastal ocean remote sensing from lab demonstration to flight like environment testing. Vibration testing to meet the GEVS requirements for a geostationary orbit launch will be performed. The multiple slit design reduces the required telescope aperture leading to mass and volume reductions over conventional spectrometers when applied to the GEO-CAPE oceans mission. The MOS program is entering year 3 of the 3-year program where assembly and test activities will demonstrate the performance of the MOS concept. This paper discusses the instrument design, fabrication and assembly. It outlines the test plan to realize a technology readiness level of 6. Testing focuses on characterizing radiometric impacts of the multiple slit images multiplexed onto a common focal plane, and assesses the resulting uncertainties imparted to the ocean color data products. The MOS instrument implementation for GEO-CAPE provides system benefits that can lead to cost savings and risk reduction while meeting the science objectives of understanding the dynamic coastal ocean environment.

  6. Advances in miniature spectrometer and sensor development

    NASA Astrophysics Data System (ADS)

    Malinen, Jouko; Rissanen, Anna; Saari, Heikki; Karioja, Pentti; Karppinen, Mikko; Aalto, Timo; Tukkiniemi, Kari

    2014-05-01

    Miniaturization and cost reduction of spectrometer and sensor technologies has great potential to open up new applications areas and business opportunities for analytical technology in hand held, mobile and on-line applications. Advances in microfabrication have resulted in high-performance MEMS and MOEMS devices for spectrometer applications. Many other enabling technologies are useful for miniature analytical solutions, such as silicon photonics, nanoimprint lithography (NIL), system-on-chip, system-on-package techniques for integration of electronics and photonics, 3D printing, powerful embedded computing platforms, networked solutions as well as advances in chemometrics modeling. This paper will summarize recent work on spectrometer and sensor miniaturization at VTT Technical Research Centre of Finland. Fabry-Perot interferometer (FPI) tunable filter technology has been developed in two technical versions: Piezoactuated FPIs have been applied in miniature hyperspectral imaging needs in light weight UAV and nanosatellite applications, chemical imaging as well as medical applications. Microfabricated MOEMS FPIs have been developed as cost-effective sensor platforms for visible, NIR and IR applications. Further examples of sensor miniaturization will be discussed, including system-on-package sensor head for mid-IR gas analyzer, roll-to-roll printed Surface Enhanced Raman Scattering (SERS) technology as well as UV imprinted waveguide sensor for formaldehyde detection.

  7. What Happened with Spectrometer Magnet 2B

    SciTech Connect

    Green, Michael A

    2010-05-27

    The spectrometer solenoid is supposed to be the first magnets installed in MICE [1]-[4]. This report described what happened during the test of the MICE spectrometer solenoid 2B. First, the report describes the temperatures in the magnet, the cooler top plate and the shield during the run where the magnet quenched at 258 A. During this quench, a lead between the bottom of the HTS leads and the diode bank burned out causing the magnet to quench. Second, three methods for measuring the net heat flow into the cold mass are described. Third, there is a discussion of possible resistive heating in the HTS leads between liquid helium temperature and the copper plate, which is at about 50 K. Fourth, there is a discussion of the measured first stage heat loads in the magnet, when there is no current in the magnet. The first stage heat load calculations are based on knowing the first stage temperatures of the three two-stage pulse tube coolers and the single stage GM cooler. Fifth, the estimated heat load to the first stage when the magnet has current in it is discussed. Sixth, there is a comparison of the stage 1 heat loads in magnet 1A [5], magnet 2A [6], and magnet 2B [7]. Finally there is a discussion of recommended changes for improving the spectrometer solenoids so that the coolers can keep them cold.

  8. Sensing systems using chip-based spectrometers

    NASA Astrophysics Data System (ADS)

    Nitkowski, Arthur; Preston, Kyle J.; Sherwood-Droz, Nicolás.; Behr, Bradford B.; Bismilla, Yusuf; Cenko, Andrew T.; DesRoches, Brandon; Meade, Jeffrey T.; Munro, Elizabeth A.; Slaa, Jared; Schmidt, Bradley S.; Hajian, Arsen R.

    2014-06-01

    Tornado Spectral Systems has developed a new chip-based spectrometer called OCTANE, the Optical Coherence Tomography Advanced Nanophotonic Engine, built using a planar lightwave circuit with integrated waveguides fabricated on a silicon wafer. While designed for spectral domain optical coherence tomography (SD-OCT) systems, the same miniaturized technology can be applied to many other spectroscopic applications. The field of integrated optics enables the design of complex optical systems which are monolithically integrated on silicon chips. The form factors of these systems can be significantly smaller, more robust and less expensive than their equivalent free-space counterparts. Fabrication techniques and material systems developed for microelectronics have previously been adapted for integrated optics in the telecom industry, where millions of chip-based components are used to power the optical backbone of the internet. We have further adapted the photonic technology platform for spectroscopy applications, allowing unheard-of economies of scale for these types of optical devices. Instead of changing lenses and aligning systems, these devices are accurately designed programmatically and are easily customized for specific applications. Spectrometers using integrated optics have large advantages in systems where size, robustness and cost matter: field-deployable devices, UAVs, UUVs, satellites, handheld scanning and more. We will discuss the performance characteristics of our chip-based spectrometers and the type of spectral sensing applications enabled by this technology.

  9. Autonomously Calibrating a Quadrupole Mass Spectrometer

    NASA Technical Reports Server (NTRS)

    Lee, Seungwon; Bornstein, Benjamin J.

    2009-01-01

    A computer program autonomously manages the calibration of a quadrupole ion mass spectrometer intended for use in monitoring concentrations and changes in concentrations of organic chemicals in the cabin air of the International Space Station. The instrument parameters calibrated include the voltage on a channel electron multiplier, a discriminator threshold, and an ionizer current. Calibration is achieved by analyzing the mass spectrum obtained while sweeping the parameter ranges in a heuristic procedure, developed by mass spectrometer experts, that involves detection of changes in signal trends that humans can easily recognize but cannot necessarily be straightforwardly codified in an algorithm. The procedure includes calculation of signal-to-noise ratios, signal-increase rates, and background-noise-increase rates; finding signal peaks; and identifying peak patterns. The software provides for several recovery-from-error scenarios and error-handling schemes. The software detects trace amounts of contaminant gases in the mass spectrometer and notifies associated command- and-data-handling software to schedule a cleaning. Furthermore, the software autonomously analyzes the mass spectrum to determine whether the parameters of a radio-frequency ramp waveform are set properly so that the peaks of the mass spectrum are at expected locations.

  10. The wide-angle neutron spin echo spectrometer project WASP

    SciTech Connect

    Ehlers, Georg

    2007-01-01

    This paper describes design and optimization for the wide angle spin-echo spectrometer (WASP) presently being planned at the ILL. The spectrometer will be a replacement for the high intensity spectrometer IN11 and will enhance its signal by more than one order of magnitude while maintaining the resolution of the present spectrometer. The paper outlines the magnetic field calculations and the considerations about possible limitations. The projected performance has been verified carefully by Monte Carlo raytracing and Biot-Savart magnetic field calculations. The maximum momentum transfer of the new spectrometer is to be extended to 4 angstroms {sup -1}.

  11. Method of multiplexed analysis using ion mobility spectrometer

    DOEpatents

    Belov, Mikhail E.; Smith, Richard D.

    2009-06-02

    A method for analyzing analytes from a sample introduced into a Spectrometer by generating a pseudo random sequence of a modulation bins, organizing each modulation bin as a series of submodulation bins, thereby forming an extended pseudo random sequence of submodulation bins, releasing the analytes in a series of analyte packets into a Spectrometer, thereby generating an unknown original ion signal vector, detecting the analytes at a detector, and characterizing the sample using the plurality of analyte signal subvectors. The method is advantageously applied to an Ion Mobility Spectrometer, and an Ion Mobility Spectrometer interfaced with a Time of Flight Mass Spectrometer.

  12. [Design of Dual-Beam Spectrometer in Spectrophotometer for Colorimetry].

    PubMed

    Liu, Yi-xuan; Yan, Chang-xiang

    2015-07-01

    Spectrophotometers for colorimetry are usually composed of two independent and identical spectrometers. In order to reduce the volume of spectrophotometer for colorimetry, a design method of double-beam spectrometer is put forward. A traditional spectrometer is modified so that a new spectrometer can realize the function of double spectrometers, which is especially suitable for portable instruments. One slit is replaced by the double-slit, than two beams of spectrum can be detected. The working principle and design requirement of double-beam spectrometer are described. A spectrometer of portable spectrophotometer is designed by this method. A toroidal imaging mirror is used for the Czerny-Turner double-beam spectrometer in this paper, which can better correct astigmatism, and prevent the dual-beam spectral crosstalk. The results demonstrate that the double-beam spectrometer designed by this method meets the design specifications, with the spectral resolution less than 10 nm, the spectral length of 9.12 mm, and the volume of 57 mm x 54 mm x 23 mm, and without the dual-beam spectral overlap in the detector either. Comparing with a traditional spectrophotometer, the modified spectrophotometer uses a set of double-beam spectrometer instead of two sets of spectrometers, which can greatly reduce the volume. This design method can be specially applied in portable spectrophotometers, also can be widely applied in other double-beam spectrophotometers, which offers a new idea for the design of dual-beam spectrophotometers.

  13. [Development of a high resolution simultaneous microwave plasma torch spectrometer].

    PubMed

    Jiang, Jie; Huan, Yan-Fu; Jin, Wei; Feng, Guo-Dong; Fei, Qiang; Cao, Yan-Bo; Jin, Qin-Han

    2007-11-01

    A unique high resolution simultaneous microwave plasma torch (MPT) atomic emission spectrometer was developed and studied preliminarily. Some advanced technologies were applied to the spectrometer, such as echelle grating, UV-intensified CCD array detector, adjustable microwave generator, and water cooling system for the generator, etc. The detection limits of the spectrometer for some elements were determined, the spectral resolution and pixel resolution of the spectrometer were calculated, and an analysis of a practical sample was carried out. The preliminary results demonstrate that such simultaneous spectrometer has advantages of saving sample and time, possessing high sensitivity and resolution, and low-cost for the purchase and maintenance. Taking analytical figures of merit into consideration, the high resolution simultaneous MPT spectrometer will have extended application areas and greater competition potential as compared with sequential MPT spectrometers.

  14. Mathematical Simulation for Integrated Linear Fresnel Spectrometer Chip

    NASA Technical Reports Server (NTRS)

    Park, Yeonjoon; Yoon, Hargoon; Lee, Uhn; King, Glen C.; Choi, Sang H.

    2012-01-01

    A miniaturized solid-state optical spectrometer chip was designed with a linear gradient-gap Fresnel grating which was mounted perpendicularly to a sensor array surface and simulated for its performance and functionality. Unlike common spectrometers which are based on Fraunhoffer diffraction with a regular periodic line grating, the new linear gradient grating Fresnel spectrometer chip can be miniaturized to a much smaller form-factor into the Fresnel regime exceeding the limit of conventional spectrometers. This mathematical calculation shows that building a tiny motionless multi-pixel microspectrometer chip which is smaller than 1 cubic millimter of optical path volume is possible. The new Fresnel spectrometer chip is proportional to the energy scale (hc/lambda), while the conventional spectrometers are proportional to the wavelength scale (lambda). We report the theoretical optical working principle and new data collection algorithm of the new Fresnel spectrometer to build a compact integrated optical chip.

  15. Development of a Gas Filled Magnet spectrometer coupled with the Lohengrin spectrometer for fission study

    NASA Astrophysics Data System (ADS)

    Kessedjian, G.; Chebboubi, A.; Faust, H.; Köster, U.; Materna, T.; Sage, C.; Serot, O.

    2013-03-01

    The accurate knowledge of the fission of actinides is necessary for studies of innovative nuclear reactor concepts. The fission yields have a direct influence on the evaluation of the fuel inventory or the reactor residual power after shutdown. A collaboration between the ILL, LPSC and CEA has developed a measurement program on fission fragment distributions at ILL in order to measure the isotopic and isomeric yields. The method is illustrated using the 233U(n,f)98Y reaction. However, the extracted beam from the Lohengrin spectrometer is not isobaric ions which limits the low yield measurements. Presently, the coupling of the Lohengrin spectrometer with a Gas Filled Magnet (GFM) is studied at the ILL in order to define and validate the enhanced purification of the extracted beam. This work will present the results of the spectrometer characterisation, along with a comparison with a dedicated Monte Carlo simulation especially developed for this purpose.

  16. Spectrometers for RF breakdown studies for CLIC

    NASA Astrophysics Data System (ADS)

    Jacewicz, M.; Ziemann, V.; Ekelöf, T.; Dubrovskiy, A.; Ruber, R.

    2016-08-01

    An e+e- collider of several TeV energy will be needed for the precision studies of any new physics discovered at the LHC collider at CERN. One promising candidate is CLIC, a linear collider which is based on a two-beam acceleration scheme that efficiently solves the problem of power distribution to the acceleration structures. The phenomenon that currently prevents achieving high accelerating gradients in high energy accelerators such as the CLIC is the electrical breakdown at very high electrical field. The ongoing experimental work within the CLIC collaboration is trying to benchmark the theoretical models focusing on the physics of vacuum breakdown which is responsible for the discharges. In order to validate the feasibility of accelerating structures and observe the characteristics of the vacuum discharges and their eroding effects on the structure two dedicated spectrometers are now commissioned at the high-power test-stands at CERN. First, the so called Flashbox has opened up a possibility for non-invasive studies of the emitted breakdown currents during two-beam acceleration experiments. It gives a unique possibility to measure the energy of electrons and ions in combination with the arrival time spectra and to put that in context with accelerated beam, which is not possible at any of the other existing test-stands. The second instrument, a spectrometer for detection of the dark and breakdown currents, is operated at one of the 12 GHz stand-alone test-stands at CERN. Built for high repetition rate operation it can measure the spatial and energy distributions of the electrons emitted from the acceleration structure during a single RF pulse. Two new analysis tools: discharge impedance tracking and tomographic image reconstruction, applied to the data from the spectrometer make possible for the first time to obtain the location of the breakdown inside the structure both in the transversal and longitudinal direction thus giving a more complete picture of the

  17. Metrology for terahertz time-domain spectrometers

    NASA Astrophysics Data System (ADS)

    Molloy, John F.; Naftaly, Mira

    2015-12-01

    In recent years the terahertz time-domain spectrometer (THz TDS) [1] has emerged as a key measurement device for spectroscopic investigations in the frequency range of 0.1-5 THz. To date, almost every type of material has been studied using THz TDS, including semiconductors, ceramics, polymers, metal films, liquid crystals, glasses, pharmaceuticals, DNA molecules, proteins, gases, composites, foams, oils, and many others. Measurements with a TDS are made in the time domain; conversion from the time domain data to a frequency spectrum is achieved by applying the Fourier Transform, calculated numerically using the Fast Fourier Transform (FFT) algorithm. As in many other types of spectrometer, THz TDS requires that the sample data be referenced to similarly acquired data with no sample present. Unlike frequency-domain spectrometers which detect light intensity and measure absorption spectra, a TDS records both amplitude and phase information, and therefore yields both the absorption coefficient and the refractive index of the sample material. The analysis of the data from THz TDS relies on the assumptions that: a) the frequency scale is accurate; b) the measurement of THz field amplitude is linear; and c) that the presence of the sample does not affect the performance characteristics of the instrument. The frequency scale of a THz TDS is derived from the displacement of the delay line; via FFT, positioning errors may give rise to frequency errors that are difficult to quantify. The measurement of the field amplitude in a THz TDS is required to be linear with a dynamic range of the order of 10 000. And attention must be given to the sample positioning and handling in order to avoid sample-related errors.

  18. A Micro-Opto-Mechanical Photoacoustic Spectrometer

    SciTech Connect

    Kotovsky, J

    2008-10-17

    This report describes progress achieved in a one-year LDRD feasibility study of a Photo Acoustic Spectrometer (PAS). Specifically, this team sought to create an all-optical and very small PhotoAcoustic Spectrometer Sensing system (PASS system). The PASS system includes all the hardware needed within a gas environment to analyze the presence of a large variety of molecules. The all-optical PASS system requires only two optical-fibers to communicate with the opto-electronic power and readout systems that exist outside of the gas environment. These systems can be at any distance from the PASS system as signal loss through the optical fibers is very small. The PASS system is intended to be placed in a small space where gases need to be measured and thus must be very small. The size and all-optical constraints placed on the PASS system demand a new design. The PASS system design includes a novel acoustic chamber, optical sensor, power fiber coupling and sensing fiber coupling. Our collaborators at the Atomic Weapons Establishment (AWE) have proven the capabilities of a complete photoacoustic spectrometer that uses a macro-scale PASS system (first 2 references). It was our goal to miniaturize the PASS system and turn it into an all-optical system to allow for its use in confined spaces that prohibit electrical devices. This goal demanded the study of all the system components, selection of an appropriate optical readout system and the design and integration of the optical sensor to the PASS system. A stretch goal was to fabricate a completed PASS system prototype.

  19. The 8-18 GHz radar spectrometer

    NASA Technical Reports Server (NTRS)

    Bush, T. F.; Ulaby, F. T.

    1973-01-01

    The design, construction, testing, and accuracy of an 8-18 GHz radar spectrometer, an FM-CW system which employs a dual antenna system, is described. The antennas, transmitter, and a portion of the receiver are mounted at the top of a 26 meter hydraulic boom which is in turn mounted on a truck for system mobility. HH and VV polarized measurements are possible at incidence angles ranging from 0 deg. to 80 deg. Calibration is accomplished by referencing the measurements against a Luneberg lens of known radar cross section.

  20. The Apollo 17 far ultraviolet spectrometer experiment

    NASA Technical Reports Server (NTRS)

    Fastie, W. G.

    1972-01-01

    The Apollo 17 command service module in lunar orbit will carry a far ultraviolet scanning spectrometer whose prime mission will be to measure the composition of the lunar atmosphere. Additional observations will include the spectral lunar albedo, the temporary atmosphere injected by the engines of the lunar exploration module, the solar system atmosphere, the galactic atmosphere and the spectra of astronomical sources, including the earth. A detailed description of the experimental equipment which observes the spectral range 1180 to 1680 A, the observing program and broad speculation about the possible results of the experiment, are presented.