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Sample records for absolute source activity

  1. Active radiometric calorimeter for absolute calibration of radioactive sources

    SciTech Connect

    Stump, K.E.; DeWerd, L.A.; Rudman, D.A.; Schima, S.A.

    2005-03-01

    This report describes the design and initial noise floor measurements of a radiometric calorimeter designed to measure therapeutic medical radioactive sources. The instrument demonstrates a noise floor of approximately 2 nW. This low noise floor is achieved by using high temperature superconducting (HTS) transition edge sensor (TES) thermometers in a temperature-control feedback loop. This feedback loop will be used to provide absolute source calibrations based upon the electrical substitution method. Other unique features of the calorimeter are (a) its ability to change sources for calibration without disrupting the vacuum of the instrument, and (b) the ability to measure the emitted power of a source in addition to the total contained source power.

  2. Amaryllidaceae alkaloids: Absolute configuration and biological activity.

    PubMed

    Cimmino, Alessio; Masi, Marco; Evidente, Marco; Superchi, Stefano; Evidente, Antonio

    2017-09-01

    Plants belonging to the Amaryllidaceae family are well known for their ornamental and medicinal use. Plant members of this group are distributed through both tropical and subtropical regions of the world and are dominant in Andean South America, the Mediterranean basin, and southern Africa. Amaryllidaceae plants have been demonstrated to be a good source of alkaloids with a large spectrum of biological activities, the latter being strictly related to the absolute stereochemistry of the alkaloid scaffold. Among them, great importance for practical applications in medicine has galanthamine, which has already spawned an Alzheimer's prescription drug as a potent and selective inhibitor of the enzyme acetylcholinesterase. Furthermore, lycorine as well as its related isocarbostyryl analogs narciclasine and pancratistatine have shown a strong anticancer activity in vitro against different solid tumors with malignant prognosis. This review addresses the assignment of the absolute configuration of several Amaryllidaceae alkaloids and its relationship with their biological activities. © 2017 Wiley Periodicals, Inc.

  3. Absolute calorimetric calibration of low energy brachytherapy sources

    NASA Astrophysics Data System (ADS)

    Stump, Kurt E.

    In the past decade there has been a dramatic increase in the use of permanent radioactive source implants in the treatment of prostate cancer. A small radioactive source encapsulated in a titanium shell is used in this type of treatment. The radioisotopes used are generally 125I or 103Pd. Both of these isotopes have relatively short half-lives, 59.4 days and 16.99 days, respectively, and have low-energy emissions and a low dose rate. These factors make these sources well suited for this application, but the calibration of these sources poses significant metrological challenges. The current standard calibration technique involves the measurement of ionization in air to determine the source air-kerma strength. While this has proved to be an improvement over previous techniques, the method has been shown to be metrologically impure and may not be the ideal means of calbrating these sources. Calorimetric methods have long been viewed to be the most fundamental means of determining source strength for a radiation source. This is because calorimetry provides a direct measurement of source energy. However, due to the low energy and low power of the sources described above, current calorimetric methods are inadequate. This thesis presents work oriented toward developing novel methods to provide direct and absolute measurements of source power for low-energy low dose rate brachytherapy sources. The method is the first use of an actively temperature-controlled radiation absorber using the electrical substitution method to determine total contained source power of these sources. The instrument described operates at cryogenic temperatures. The method employed provides a direct measurement of source power. The work presented here is focused upon building a metrological foundation upon which to establish power-based calibrations of clinical-strength sources. To that end instrument performance has been assessed for these source strengths. The intent is to establish the limits of

  4. Absolute beam intensity measurements at the Intense Pulsed Neutron Source

    SciTech Connect

    Iverson, Erik B.; Carpenter, J. M.; Hill, E. J.

    1997-01-01

    The three moderators at the Intense Pulsed Neutron Source are of cryogenic methane (CH4): one of liquid methane at 100 K, and two of solid methane at 30 K. These moderators produce intense beams of both cold and thermal neutrons. The moderators are each of a different physical configuration in order to tailor their performance for the fourteen instruments and test facilities that operate on the twelve neutron beams. IPNS has started a program to enhance the effectiveness of its target/moderator/reflector system. This program involves both Monte Carlo computer modeling of the system and measuring the characteristics of the neutron beams. The measurements reported here provide absolute spectra using foil activation techniques joined with time-of-flight measurements performed with thin beam monitor detectors installed at the neutron scattering instruments. We also outline a codified procedure which we believe will be useful at other pulsed neutron sources to perform equivalent measurements. (auth)

  5. Development of NANA: A Fast-Scintillator, Coincidence Gamma-ray Array for Radioactive Source Characterisation and Absolute Activity Measurements at the UK National Physical Laboratory

    NASA Astrophysics Data System (ADS)

    Regan, P. H.; Shearman, R.; Judge, S. M.; Lorusso, G.; Main, P.; Bell, S.; Collins, S. M.; Ivanov, P.; Jerome, S. M.; Keightley, J. D.; Larijani, C.; Lotay, G.; Pearce, A. K.

    2015-06-01

    A multi-detector modular coincidence gamma-ray spectrometer is being designed and constructed for use at the UK's National Physical Laboratory (NPL) for use in direct measurement and metrological standardisation of nuclear decay activities. In its first generation, the NPL National Nuclear Array (NANA) will consist of twelve individual halide scintillation detectors placed in a high-efficiency geometry around a well-defined central point source position. This brief conference paper provides details of the measured detector module and coincidence energy and timing responses for the LaBr3(Ce) detectors which will be used in the NANA array. Preliminary GEANT4 simulations of the array's full energy peak efficiency and expected gamma-ray coincidence response are also presented.

  6. Issues in Absolute Spectral Radiometric Calibration: Intercomparison of Eight Sources

    NASA Technical Reports Server (NTRS)

    Goetz, Alexander F. H.; Kindel, Bruce; Pilewskie, Peter

    1998-01-01

    The application of atmospheric models to AVIRIS and other spectral imaging data to derive surface reflectance requires that the sensor output be calibrated to absolute radiance. Uncertainties in absolute calibration are to be expected, and claims of 92% accuracy have been published. Measurements of accurate surface albedos and cloud absorption to be used in radiative balance calculations depend critically on knowing the absolute spectral-radiometric response of the sensor. The Earth Observing System project is implementing a rigorous program of absolute radiometric calibration for all optical sensors. Since a number of imaging instruments that provide output in terms of absolute radiance are calibrated at different sites, it is important to determine the errors that can be expected among calibration sites. Another question exists about the errors in the absolute knowledge of the exoatmospheric spectral solar irradiance.

  7. Metrological activity determination of 133Ba by sum-peak absolute method

    NASA Astrophysics Data System (ADS)

    da Silva, R. L.; de Almeida, M. C. M.; Delgado, J. U.; Poledna, R.; Santos, A.; de Veras, E. V.; Rangel, J.; Trindade, O. L.

    2016-07-01

    The National Laboratory for Metrology of Ionizing Radiation provides gamma sources of radionuclide and standardized in activity with reduced uncertainties. Relative methods require standards to determine the sample activity while the absolute methods, as sum-peak, not. The activity is obtained directly with good accuracy and low uncertainties. 133Ba is used in research laboratories and on calibration of detectors for analysis in different work areas. Classical absolute methods don't calibrate 133Ba due to its complex decay scheme. The sum-peak method using gamma spectrometry with germanium detector standardizes 133Ba samples. Uncertainties lower than 1% to activity results were obtained.

  8. Progress Report of CNES Activities Regarding the Absolute Calibration Method

    DTIC Science & Technology

    2010-11-01

    several receivers (Ashtech Z12-T, Septentrio PolaRx2, and Dicom GTR50) and a GNSS signal simulator (Spirent 4760) according to the temperature and...laboratories, Ashtech Z12- T, Septentrio PolaRx2, and Dicom GTR50, can be calibrated with the absolute method [6,8]. The last works concerned the...Ashtech, Septentrio, and Dicom receiver calibrations. Table 2. Uncertainty of the different receiver calibrations. Uncertainty Source

  9. Neutron activation analysis of certified samples by the absolute method

    NASA Astrophysics Data System (ADS)

    Kadem, F.; Belouadah, N.; Idiri, Z.

    2015-07-01

    The nuclear reactions analysis technique is mainly based on the relative method or the use of activation cross sections. In order to validate nuclear data for the calculated cross section evaluated from systematic studies, we used the neutron activation analysis technique (NAA) to determine the various constituent concentrations of certified samples for animal blood, milk and hay. In this analysis, the absolute method is used. The neutron activation technique involves irradiating the sample and subsequently performing a measurement of the activity of the sample. The fundamental equation of the activation connects several physical parameters including the cross section that is essential for the quantitative determination of the different elements composing the sample without resorting to the use of standard sample. Called the absolute method, it allows a measurement as accurate as the relative method. The results obtained by the absolute method showed that the values are as precise as the relative method requiring the use of standard sample for each element to be quantified.

  10. An absolute calibration source for laboratory and satellite infrared spectrometers.

    PubMed

    Karoli, A R; Hickey, J R; Nelson, R E

    1967-07-01

    A compact blackbody source with an operating range of -40 degrees C to + 60 degrees C, utilizing thermoelectric heat pumping for uniform and stable temperature control, has been developed. The blackbody radiator (target) consists of a blackened honeycomb cavity array coupled to four matched, two-stage (cascade type) thermoelectric modules. This array, located within a temperature-regulated baffle system, produces a blackbody of high emissivity (>0.995) with small thermal gradients over the source area (65 cm(2)). Heat pumping of the target and baffles is controlled, independently, by two interference-free, proportional regulators which provide linear thermal control in both the heating and cooling modes of operation. Additional features of this blackbody source include excellent stability and rapid response to input temperature changes. Provisions are made for temperature monitoring at five locations on the target and at the center of each of the four baffle units. Performance characteristics and test results obtained in nonabsorbing atmospheres and under vacuum conditions are presented, as are the details of construction and operation.

  11. Diagnostic Application of Absolute Neutron Activation Analysis in Hematology

    SciTech Connect

    Zamboni, C.B.; Oliveira, L.C.; Dalaqua, L. Jr.

    2004-10-03

    The Absolute Neutron Activation Analysis (ANAA) technique was used to determine element concentrations of Cl and Na in blood of healthy group (male and female blood donators), select from Blood Banks at Sao Paulo city, to provide information which can help in diagnosis of patients. This study permitted to perform a discussion about the advantages and limitations of using this nuclear methodology in hematological examinations.

  12. Absolute flux density calibrations of radio sources: 2.3 GHz

    NASA Technical Reports Server (NTRS)

    Freiley, A. J.; Batelaan, P. D.; Bathker, D. A.

    1977-01-01

    A detailed description of a NASA/JPL Deep Space Network program to improve S-band gain calibrations of large aperture antennas is reported. The program is considered unique in at least three ways; first, absolute gain calibrations of high quality suppressed-sidelobe dual mode horns first provide a high accuracy foundation to the foundation to the program. Second, a very careful transfer calibration technique using an artificial far-field coherent-wave source was used to accurately obtain the gain of one large (26 m) aperture. Third, using the calibrated large aperture directly, the absolute flux density of five selected galactic and extragalactic natural radio sources was determined with an absolute accuracy better than 2 percent, now quoted at the familiar 1 sigma confidence level. The follow-on considerations to apply these results to an operational network of ground antennas are discussed. It is concluded that absolute gain accuracies within + or - 0.30 to 0.40 db are possible, depending primarily on the repeatability (scatter) in the field data from Deep Space Network user stations.

  13. Absolute activity measurement of radon gas at IRA-METAS

    NASA Astrophysics Data System (ADS)

    Spring, Philippe; Nedjadi, Youcef; Bailat, Claude; Triscone, Gilles; Bochud, François

    2006-12-01

    This paper describes the system of the Swiss national metrological institute (IRA-METAS) for the absolute standardisation of radon gas. This method relies on condensing radon under vacuum conditions within a specified cold area using a cryogenerator, and detecting its alpha particles with an ion-implanted silicon detector, through a very accurately defined solid angle. The accuracy of this defined solid angle standardisation technique was corroborated by another primary measurement method involving 4 πγ NaI(Tl) integral counting and Monte Carlo efficiency calculations. The 222Rn standard submitted by IRA-METAS to the Système International de Référence (SIR) at the Bureau International des Poids et Mesures (BIPM) has also been found to be consistent with an analogous standard submitted by the German national metrological institute (PTB). IRA-METAS is able to deliver radon standards, with activities ranging from a few kBq to 350 kBq, in NIST-Type ampoules, and glass or steel containers usable for calibrating radon-measuring instruments.

  14. Absolute Power Spectral Density Changes in the Magnetoencephalographic Activity During the Transition from Childhood to Adulthood.

    PubMed

    Gómez, Carlos M; Rodríguez-Martínez, Elena I; Fernández, Alberto; Maestú, Fernando; Poza, Jesús; Gómez, Carlos

    2017-01-01

    The aim of this study was to define the pattern of reduction in absolute power spectral density (PSD) of magnetoencephalography (MEG) signals throughout development. Specifically, we wanted to explore whether the human skull's high permeability for electromagnetic fields would allow us to question whether the pattern of absolute PSD reduction observed in the human electroencephalogram is due to an increase in the skull's resistive properties with age. Furthermore, the topography of the MEG signals during maturation was explored, providing additional insights about the areas and brain rhythms related to late maturation in the human brain. To attain these goals, spontaneous MEG activity was recorded from 148 sensors in a sample of 59 subjects divided into three age groups: children/adolescents (7-14 years), young adults (17-20 years) and adults (21-26 years). Statistical testing was carried out by means of an analysis of variance (ANOVA), with "age group" as between-subject factor and "sensor group" as within-subject factor. Additionally, correlations of absolute PSD with age were computed to assess the influence of age on the spectral content of MEG signals. Results showed a broadband PSD decrease in frontal areas, which suggests the late maturation of this region, but also a mild increase in high frequency PSD with age in posterior areas. These findings suggest that the intensity of the neural sources during spontaneous brain activity decreases with age, which may be related to synaptic pruning.

  15. Absolute pulse energy measurements of soft x-rays at the Linac Coherent Light Source.

    PubMed

    Tiedtke, K; Sorokin, A A; Jastrow, U; Juranić, P; Kreis, S; Gerken, N; Richter, M; Arp, U; Feng, Y; Nordlund, D; Soufli, R; Fernández-Perea, M; Juha, L; Heimann, P; Nagler, B; Lee, H J; Mack, S; Cammarata, M; Krupin, O; Messerschmidt, M; Holmes, M; Rowen, M; Schlotter, W; Moeller, S; Turner, J J

    2014-09-08

    This paper reports novel measurements of x-ray optical radiation on an absolute scale from the intense and ultra-short radiation generated in the soft x-ray regime of a free electron laser. We give a brief description of the detection principle for radiation measurements which was specifically adapted for this photon energy range. We present data characterizing the soft x-ray instrument at the Linac Coherent Light Source (LCLS) with respect to the radiant power output and transmission by using an absolute detector temporarily placed at the downstream end of the instrument. This provides an estimation of the reflectivity of all x-ray optical elements in the beamline and provides the absolute photon number per bandwidth per pulse. This parameter is important for many experiments that need to understand the trade-offs between high energy resolution and high flux, such as experiments focused on studying materials via resonant processes. Furthermore, the results are compared with the LCLS diagnostic gas detectors to test the limits of linearity, and observations are reported on radiation contamination from spontaneous undulator radiation and higher harmonic content.

  16. Performance of Different Light Sources for the Absolute Calibration of Radiation Thermometers

    NASA Astrophysics Data System (ADS)

    Martín, M. J.; Mantilla, J. M.; del Campo, D.; Hernanz, M. L.; Pons, A.; Campos, J.

    2017-09-01

    The evolving mise en pratique for the definition of the kelvin (MeP-K) [1, 2] will, in its forthcoming edition, encourage the realization and dissemination of the thermodynamic temperature either directly (primary thermometry) or indirectly (relative primary thermometry) via fixed points with assigned reference thermodynamic temperatures. In the last years, the Centro Español de Metrología (CEM), in collaboration with the Instituto de Óptica of Consejo Superior de Investigaciones Científicas (IO-CSIC), has developed several setups for absolute calibration of standard radiation thermometers using the radiance method to allow CEM the direct dissemination of the thermodynamic temperature and the assignment of the thermodynamic temperatures to several fixed points. Different calibration facilities based on a monochromator and/or a laser and an integrating sphere have been developed to calibrate CEM's standard radiation thermometers (KE-LP2 and KE-LP4) and filter radiometer (FIRA2). This system is based on the one described in [3] placed in IO-CSIC. Different light sources have been tried and tested for measuring absolute spectral radiance responsivity: a Xe-Hg 500 W lamp, a supercontinuum laser NKT SuperK-EXR20 and a diode laser emitting at 6473 nm with a typical maximum power of 120 mW. Their advantages and disadvantages have been studied such as sensitivity to interferences generated by the laser inside the filter, flux stability generated by the radiant sources and so forth. This paper describes the setups used, the uncertainty budgets and the results obtained for the absolute temperatures of Cu, Co-C, Pt-C and Re-C fixed points, measured with the three thermometers with central wavelengths around 650 nm.

  17. Determination of the absolute stereochemistry of limonene and alpha-santalol by Raman optical activity spectroscopy.

    PubMed

    Sakamoto, Akira; Ohya, Nao; Hasegawa, Toshio; Izumi, Hiroaki; Tokita, Nakako; Hamada, Yoshiaki

    2012-04-01

    Determining the absolute stereochemistry of organic compounds in solution remains a challenge. We investigated the use of Raman optical activity (ROA) spectroscopy to address this problem. The absolute configurations of (+)-(R)- and (-)-(S)-limonene were determined by ROA spectroscopy, which can be applied to smaller amounts of sample as compared with vibrational circular dichroism (VCD) spectroscopy. This ROA method was also applied to (+)-(E)-alpha-santalol and shown to be successful in the determination of the absolute configuration of this compound. ROA spectroscopy shows promise as a useful tool for determining the absolute stereochemistry of many natural compounds.

  18. The Centaur 10199 Chariklo: investigation into rotational period, absolute magnitude, and cometary activity

    NASA Astrophysics Data System (ADS)

    Fornasier, S.; Lazzaro, D.; Alvarez-Candal, A.; Snodgrass, C.; Tozzi, G. P.; Carvano, J. M.; Jiménez-Teja, Y.; Silva, J. S.; Bramich, D. M.

    2014-08-01

    Context. Rings have recently been discovered around the Centaur 10199 Chariklo. Aims: In this paper we present new photometric data, obtained at the 4.2 m SOAR Telescope, aiming to investigate Chariklo's absolute magnitude and rotational period, which is still unknown, and to look for potential cometary activity. Methods: The field background of the images was very crowded so several approaches were used for the extraction of Chariklo fluxes. The background sources were subtracted using difference image analysis and then aperture photometry was applied. A Fourier polynomial fit was used to determine the period. Results: We find a synodic rotation period of 7.004±0.036 h. The visual absolute magnitude derived from the SOAR data is Hv = 7.03 ± 0.10. We model the rings' contribution to the flux, and find that the derived Hv is consistent with the predicted ring system aspect angle. We also revised the Chariklo system albedo (4.2%) and effective radius (119 ± 5 km) from a re-analysis of Herschel and WISE thermal data obtained during 2010 with the correct Hv value. No coma is detected from the SOAR data, nor in previous VLT images acquired in 2007-2008, where the rings' aspect angle was close to zero. The upper limit to the dust production rate is 2.5 kg/s. Figure 3 is available in electronic form at http://www.aanda.org

  19. Potential Skin Regeneration Activity and Chemical Composition of Absolute from Pueraria thunbergiana Flower.

    PubMed

    Kim, Do-Yoon; Won, Kyung-Jong; Hwang, Dae-Il; Yoon, Seok Won; Lee, Su Jin; Park, Joo-Hoon; Yoon, Myeong Sik; Kim, Bokyung; Lee, Hwan Myung

    2015-11-01

    The flower of Pueraria thunbergiana BENTH (PTBF) contains isoflavonoids and essential oil components. It has many biological and pharmacological activities, including anti-diabetes, anti-oxidant, and weight loss. However, its effect on skin regeneration remains unknown. In the present study, we isolated the absolute from PTBF through solvent extraction and determined the role of the absolute on skin regeneration-associated responses in human epidermal-keratinocytes (HaCats). The PTBF absolute, which contained 10 compounds, stimulated migration and proliferation and increased the phosphorylation of serine/threonine-specific protein kinase and extracellular signal-regulated kinasel/2 in HaCats. It induced type I and IV collagen synthesis in HaCats. In addition, treatment with PTBF absolute resulted in increased sprout outgrowth in HaCats. These findings suggest that PTBF absolute may participate in skin regeneration, probably through promotion of migration, proliferation, and collagen synthesis.

  20. Responses of absolute and specific enzyme activity to consecutive application of composted sewage sludge in a Fluventic Ustochrept.

    PubMed

    Liu, Xiao; Guo, Kangli; Huang, Lin; Ji, Zhengyu; Jiang, Huimin; Li, Hu; Zhang, Jianfeng

    2017-01-01

    Composted sewage sludge (CS) is considered a rich source of soil nutrients and significantly affects the physical, chemical, and biological characteristics of soil, but its effect on specific enzyme activity in soil is disregarded. The present experiment examined the absolute and specific enzyme activity of the enzymes involved in carbon, nitrogen, and phosphorus cycles, the diversity of soil microbial functions, and soil community composition in a Fluventic Ustochrept under a maize-wheat rotation system in North China during 2012-2015. Application of CS led to increase in MBC and in its ratio to both total organic carbon (TOC) and microbial biomass nitrogen (MBN). Absolute enzyme activity, except that of phosphatase, increased in CS-treated soils, whereas specific activity of all the enzymes declined, especially at the highest dose of CS (45 t ha-1). The diversity of soil microbial community also increased in CS-treated soils, whereas its functional diversity declined at higher doses of CS owing to the lowered specific enzyme activity. These changes indicate that CS application induced the domination of microorganisms that are not metabolically active and those that use resources more efficiently, namely fungi. Redundancy analysis showed that fundamental alterations in soil enzyme activity depend on soil pH. Soil specific enzyme activity is affected more than absolute enzyme activity by changes in soil properties, especially soil microbial activity and composition of soil microflora (as judged by the following ratios: MBC/TOC, MBC/MBN, and TOC/LOC, that is labile organic carbon) through the Pearson Correlation Coefficient. Specific enzyme activity is thus a more accurate parameter than absolute enzyme activity for monitoring the effect of adding CS on the activities and structure of soil microbial community.

  1. Absolute exponential stability of recurrent neural networks with Lipschitz-continuous activation functions and time delays.

    PubMed

    Cao, Jinde; Wang, Jun

    2004-04-01

    This paper investigates the absolute exponential stability of a general class of delayed neural networks, which require the activation functions to be partially Lipschitz continuous and monotone nondecreasing only, but not necessarily differentiable or bounded. Three new sufficient conditions are derived to ascertain whether or not the equilibrium points of the delayed neural networks with additively diagonally stable interconnection matrices are absolutely exponentially stable by using delay Halanay-type inequality and Lyapunov function. The stability criteria are also suitable for delayed optimization neural networks and delayed cellular neural networks whose activation functions are often nondifferentiable or unbounded. The results herein answer a question: if a neural network without any delay is absolutely exponentially stable, then under what additional conditions, the neural networks with delay is also absolutely exponentially stable.

  2. Antiausterity activity of arctigenin enantiomers: importance of (2R,3R)-absolute configuration.

    PubMed

    Awale, Suresh; Kato, Mamoru; Dibwe, Dya Fita; Li, Feng; Miyoshi, Chika; Esumi, Hiroyasu; Kadota, Shigetoshi; Tezuka, Yasuhiro

    2014-01-01

    From a MeOH extract of powdered roots of Wikstroemia indica, six dibenzyl-gamma-butyrolactone-type lignans with (2S,3S)-absolute configuration [(+)-arctigenin (1), (+)-matairesinol (2), (+)-trachelogenin (3), (+)-nortrachelogenin (4), (+)-hinokinin (5), and (+)-kusunokinin (6)] were isolated, whereas three dibenzyl-gamma-butyrolactone-type lignans with (2R,3R)-absolute configuration [(-)-arctigenin (1*), (-)-matairesinol (2*), (-)-trachelogenin (3*)] were isolated from Trachelospermum asiaticum. The in vitro preferential cytotoxic activity of the nine compounds was evaluated against human pancreatic PANC-1 cancer cells in nutrient-deprived medium (NDM), but none of the six lignans (1-6) with (2S,3S)-absolute configuration showed preferential cytotoxicity. On the other hand, three lignans (1*-3*) with (2R,3R)-absolute configuration exhibited preferential cytotoxicity in a concentration-dependent manner with PC50 values of 0.54, 6.82, and 5.85 microM, respectively. Furthermore, the effect of (-)- and (+)-arctigenin was evaluated against the activation of Akt, which is a key process in the tolerance to nutrition starvation. Interestingly, only (-)-arctigenin (1*) strongly suppressed the activation of Akt. These results indicate that the (2R,3R)-absolute configuration of (-)-enantiomers should be required for the preferential cytotoxicity through the inhibition of Akt activation.

  3. Young asteroidal fluid activity revealed by absolute age from apatite in carbonaceous chondrite

    NASA Astrophysics Data System (ADS)

    Zhang, Ai-Cheng; Li, Qiu-Li; Yurimoto, Hisayoshi; Sakamoto, Naoya; Li, Xian-Hua; Hu, Sen; Lin, Yang-Ting; Wang, Ru-Cheng

    2016-09-01

    Chondritic meteorites, consisting of the materials that have formed in the early solar system (ESS), have been affected by late thermal events and fluid activity to various degrees. Determining the timing of fluid activity in ESS is of fundamental importance for understanding the nature, formation, evolution and significance of fluid activity in ESS. Previous investigations have determined the relative ages of fluid activity with short-lived isotope systematics. Here we report an absolute 207Pb/206Pb isochron age (4,450+/-50 Ma) of apatite from Dar al Gani (DaG) 978, a type ~3.5, ungrouped carbonaceous chondrite. The petrographic, mineralogical and geochemical features suggest that the apatite in DaG 978 should have formed during metamorphism in the presence of a fluid. Therefore, the apatite age represents an absolute age for fluid activity in an asteroidal setting. An impact event could have provided the heat to activate this young fluid activity in ESS.

  4. Young asteroidal fluid activity revealed by absolute age from apatite in carbonaceous chondrite.

    PubMed

    Zhang, Ai-Cheng; Li, Qiu-Li; Yurimoto, Hisayoshi; Sakamoto, Naoya; Li, Xian-Hua; Hu, Sen; Lin, Yang-Ting; Wang, Ru-Cheng

    2016-09-29

    Chondritic meteorites, consisting of the materials that have formed in the early solar system (ESS), have been affected by late thermal events and fluid activity to various degrees. Determining the timing of fluid activity in ESS is of fundamental importance for understanding the nature, formation, evolution and significance of fluid activity in ESS. Previous investigations have determined the relative ages of fluid activity with short-lived isotope systematics. Here we report an absolute (207)Pb/(206)Pb isochron age (4,450±50 Ma) of apatite from Dar al Gani (DaG) 978, a type ∼3.5, ungrouped carbonaceous chondrite. The petrographic, mineralogical and geochemical features suggest that the apatite in DaG 978 should have formed during metamorphism in the presence of a fluid. Therefore, the apatite age represents an absolute age for fluid activity in an asteroidal setting. An impact event could have provided the heat to activate this young fluid activity in ESS.

  5. Mosher Amides: Determining the Absolute Stereochemistry of Optically-Active Amines

    ERIC Educational Resources Information Center

    Allen, Damian A.; Tomaso, Anthony E., Jr.; Priest, Owen P.; Hindson, David F.; Hurlburt, Jamie L.

    2008-01-01

    The use of chiral reagents for the derivatization of optically-active amines and alcohols for the purpose of determining their enantiomeric purity or absolute configuration is a tool used by many chemists. Among the techniques used, Mosher's amide and Mosher's ester analyses are among the most reliable and one of the most often used. Despite this,…

  6. Mosher Amides: Determining the Absolute Stereochemistry of Optically-Active Amines

    ERIC Educational Resources Information Center

    Allen, Damian A.; Tomaso, Anthony E., Jr.; Priest, Owen P.; Hindson, David F.; Hurlburt, Jamie L.

    2008-01-01

    The use of chiral reagents for the derivatization of optically-active amines and alcohols for the purpose of determining their enantiomeric purity or absolute configuration is a tool used by many chemists. Among the techniques used, Mosher's amide and Mosher's ester analyses are among the most reliable and one of the most often used. Despite this,…

  7. SOLAR/SOLSPEC: Scientific Objectives, Instrument Performance and Its Absolute Calibration Using a Blackbody as Primary Standard Source

    NASA Astrophysics Data System (ADS)

    Thuillier, G.; Foujols, T.; Bolsée, D.; Gillotay, D.; Hersé, M.; Peetermans, W.; Decuyper, W.; Mandel, H.; Sperfeld, P.; Pape, S.; Taubert, D. R.; Hartmann, J.

    2009-06-01

    SOLAR is a set of three solar instruments measuring the total and spectral absolute irradiance from 16 nm to 3080 nm for solar, atmospheric and climatology physics. It is an external payload for the COLUMBUS laboratory launched on 7 February 2008. The mission’s primary objective is the measurement of the solar irradiance with the highest possible accuracy, and its variability using the following instruments: SOL-ACES (SOLar Auto-Calibrating EUV/UV Spectrophotometers) consists of four grazing incidence planar gratings measuring from 16 nm to 220 nm; SOLSPEC (SOLar SPECtrum) consists of three double gratings spectrometers, covering the range 165 nm to 3080 nm; and SOVIM (SOlar Variability Irradiance Monitor) is combining two types of absolute radiometers and three-channel filter - radiometers. SOLSPEC and SOL-ACES have been calibrated by primary standard radiation sources of the Physikalisch-Technische Bundesanstalt (PTB). Below we describe SOLSPEC, and its performance.

  8. New enantiomeric fluorine-containing derivatives of sulforaphane: synthesis, absolute configurations and biological activity.

    PubMed

    Kiełbasiński, Piotr; Łuczak, Jerzy; Cierpiał, Tomasz; Błaszczyk, Jarosław; Sieroń, Lesław; Wiktorska, Katarzyna; Lubelska, Katarzyna; Milczarek, Małgorzata; Chilmończyk, Zdzisław

    2014-04-09

    Three pairs of enantiomers of the unknown sulforaphane analogs bearing organofluorine substituents bonded to the sulfinyl sulfur atom and having different number of methylene groups in the central carbon chain were synthesized and fully characterized, including determination of their absolute configurations. All the new compounds were tested in vitro for their cytotoxicity against melanoma cells to show increased activity in comparison with the natural sulforaphane. The influence of the particular structural changes in the molecule on the cytotoxicity is discussed.

  9. Inversion of Multi-Station Schumann Resonance Background Records for Global Lightning Activity in Absolute Units

    NASA Astrophysics Data System (ADS)

    Williams, E. R.; Mushtak, V. C.; Guha, A.; Boldi, R. A.; Bor, J.; Nagy, T.; Satori, G.; Sinha, A. K.; Rawat, R.; Hobara, Y.; Sato, M.; Takahashi, Y.; Price, C. G.; Neska, M.; Alexander, K.; Yampolski, Y.; Moore, R. C.; Mitchell, M. F.; Fraser-Smith, A. C.

    2014-12-01

    Every lightning flash contributes energy to the TEM mode of the natural global waveguide that contains the Earth's Schumann resonances. The modest attenuation at ELF (0.1 dB/Mm) allows for the continuous monitoring of the global lightning with a small number of receiving stations worldwide. In this study, nine ELF receiving sites (in Antarctica (3 sites), Hungary, India, Japan, Poland, Spitsbergen and USA) are used to provide power spectra at 12-minute intervals in two absolutely calibrated magnetic fields and occasionally, one electric field, with up to five resonance modes each. The observables are the extracted modal parameters (peak intensity, peak frequency and Q-factor) for each spectrum. The unknown quantities are the geographical locations of three continental lightning 'chimneys' and their lightning source strengths in absolute units (C2 km2/sec). The unknowns are calculated from the observables by the iterative inversion of an evolving 'sensitivity matrix' whose elements are the partial derivatives of each observable for all receiving sites with respect to each unknown quantity. The propagation model includes the important day-night asymmetry of the natural waveguide. To overcome the problem of multiple minima (common in inversion problems of this kind), location information from the World Wide Lightning Location Network has been used to make initial guess solutions based on centroids of stroke locations in each chimney. Results for five consecutive days in 2009 (Jan 7-11) show UT variations with the African chimney dominating on four of five days, and America dominating on the fifth day. The amplitude variations in absolute source strength exceed that of the 'Carnegie curve' of the DC global circuit by roughly twofold. Day-to-day variations in chimney source strength are of the order of tens of percent. Examination of forward calculations performed with the global inversion solution often show good agreement with the observed diurnal variations at

  10. Easy Absolute Values? Absolutely

    ERIC Educational Resources Information Center

    Taylor, Sharon E.; Mittag, Kathleen Cage

    2015-01-01

    The authors teach a problem-solving course for preservice middle-grades education majors that includes concepts dealing with absolute-value computations, equations, and inequalities. Many of these students like mathematics and plan to teach it, so they are adept at symbolic manipulations. Getting them to think differently about a concept that they…

  11. Easy Absolute Values? Absolutely

    ERIC Educational Resources Information Center

    Taylor, Sharon E.; Mittag, Kathleen Cage

    2015-01-01

    The authors teach a problem-solving course for preservice middle-grades education majors that includes concepts dealing with absolute-value computations, equations, and inequalities. Many of these students like mathematics and plan to teach it, so they are adept at symbolic manipulations. Getting them to think differently about a concept that they…

  12. Young asteroidal fluid activity revealed by absolute age from apatite in carbonaceous chondrite

    PubMed Central

    Zhang, Ai-Cheng; Li, Qiu-Li; Yurimoto, Hisayoshi; Sakamoto, Naoya; Li, Xian-Hua; Hu, Sen; Lin, Yang-Ting; Wang, Ru-Cheng

    2016-01-01

    Chondritic meteorites, consisting of the materials that have formed in the early solar system (ESS), have been affected by late thermal events and fluid activity to various degrees. Determining the timing of fluid activity in ESS is of fundamental importance for understanding the nature, formation, evolution and significance of fluid activity in ESS. Previous investigations have determined the relative ages of fluid activity with short-lived isotope systematics. Here we report an absolute 207Pb/206Pb isochron age (4,450±50 Ma) of apatite from Dar al Gani (DaG) 978, a type ∼3.5, ungrouped carbonaceous chondrite. The petrographic, mineralogical and geochemical features suggest that the apatite in DaG 978 should have formed during metamorphism in the presence of a fluid. Therefore, the apatite age represents an absolute age for fluid activity in an asteroidal setting. An impact event could have provided the heat to activate this young fluid activity in ESS. PMID:27682449

  13. A comparison of absolute calibrations of a radiation thermometer based on a monochromator and a tunable source

    SciTech Connect

    Keawprasert, T.; Anhalt, K.; Taubert, D. R.; Sperling, A.; Schuster, M.; Nevas, S.

    2013-09-11

    An LP3 radiation thermometer was absolutely calibrated at a newly developed monochromator-based set-up and the TUneable Lasers in Photometry (TULIP) facility of PTB in the wavelength range from 400 nm to 1100 nm. At both facilities, the spectral radiation of the respective sources irradiates an integrating sphere, thus generating uniform radiance across its precision aperture. The spectral irradiance of the integrating sphere is determined via an effective area of a precision aperture and a Si trap detector, traceable to the primary cryogenic radiometer of PTB. Due to the limited output power from the monochromator, the absolute calibration was performed with the measurement uncertainty of 0.17 % (k= 1), while the respective uncertainty at the TULIP facility is 0.14 %. Calibration results obtained by the two facilities were compared in terms of spectral radiance responsivity, effective wavelength and integral responsivity. It was found that the measurement results in integral responsivity at the both facilities are in agreement within the expanded uncertainty (k= 2). To verify the calibration accuracy, the absolutely calibrated radiation thermometer was used to measure the thermodynamic freezing temperatures of the PTB gold fixed-point blackbody.

  14. A comparison of absolute calibrations of a radiation thermometer based on a monochromator and a tunable source

    NASA Astrophysics Data System (ADS)

    Keawprasert, T.; Anhalt, K.; Taubert, D. R.; Sperling, A.; Schuster, M.; Nevas, S.

    2013-09-01

    An LP3 radiation thermometer was absolutely calibrated at a newly developed monochromator-based set-up and the TUneable Lasers in Photometry (TULIP) facility of PTB in the wavelength range from 400 nm to 1100 nm. At both facilities, the spectral radiation of the respective sources irradiates an integrating sphere, thus generating uniform radiance across its precision aperture. The spectral irradiance of the integrating sphere is determined via an effective area of a precision aperture and a Si trap detector, traceable to the primary cryogenic radiometer of PTB. Due to the limited output power from the monochromator, the absolute calibration was performed with the measurement uncertainty of 0.17 % (k = 1), while the respective uncertainty at the TULIP facility is 0.14 %. Calibration results obtained by the two facilities were compared in terms of spectral radiance responsivity, effective wavelength and integral responsivity. It was found that the measurement results in integral responsivity at the both facilities are in agreement within the expanded uncertainty (k = 2). To verify the calibration accuracy, the absolutely calibrated radiation thermometer was used to measure the thermodynamic freezing temperatures of the PTB gold fixed-point blackbody.

  15. Correction to Method of Establishing the Absolute Radiometric Accuracy of Remote Sensing Systems While On-orbit Using Characterized Stellar Sources

    NASA Technical Reports Server (NTRS)

    Bowen, Howard S.; Cunningham, Douglas M.

    2007-01-01

    The contents include: 1) Brief history of related events; 2) Overview of original method used to establish absolute radiometric accuracy of remote sensing instruments using stellar sources; and 3) Considerations to improve the stellar calibration approach.

  16. Absolute depth-dose-rate measurements for an 192Ir HDR brachytherapy source in water using MOSFET detectors.

    PubMed

    Zilio, Valéry Olivier; Joneja, Om Parkash; Popowski, Youri; Rosenfeld, Anatoly; Chawla, Rakesh

    2006-06-01

    Reported MOSFET measurements concern mostly external radiotherapy and in vivo dosimetry. In this paper, we apply the technique for absolute dosimetry in the context of HDR brachytherapy using an 192Ir source. Measured radial dose rate distributions in water for different planes perpendicular to the source axis are presented and special attention is paid to the calibration of the R and K type detectors, and to the determination of appropriate correction factors for the sensitivity variation with the increase of the threshold voltage and the energy dependence. The experimental results are compared with Monte Carlo simulated dose rate distributions. The experimental results show a good agreement with the Monte Carlo simulations: the discrepancy between experimental and Monte Carlo results being within 5% for 82% of the points and within 10% for 95% of the points. Moreover, all points except two are found to lie within the experimental uncertainties, confirming thereby the quality of the results obtained.

  17. Plasmodium falciparum: role of absolute stereochemistry in the antimalarial activity of synthetic amino alcohol antimalarial agents.

    PubMed

    Karle, J M; Olmeda, R; Gerena, L; Milhous, W K

    1993-06-01

    The (+)-isomers of mefloquine and its threo analog are 1.69 to 1.95 times more active than the (-)-isomers against chloroquine-sensitive and chloroquine-resistant Plasmodium falciparum in vitro. This large a differential between the activity of (+)- and (-)-isomers was not observed for other synthetic amino alcohol antimalarial agents containing a piperidine ring. The enantiomers of amino alcohol antimalarial agents in which the amine is part of an acyclic group, such as in halofantrine, displayed little, if any, differential antimalarial activity. Thus, the effect of absolute stereochemistry of the amino alcohol antimalarial agents on antimalarial activity appears to depend upon both the flexibility of the amine portion of the molecule and the structure of the aromatic portion of the molecule.

  18. Physical Activity: Absolute Intensity versus Relative-to-Fitness-Level Volumes.

    PubMed

    Kujala, Urho M; Pietilä, Julia; Myllymäki, Tero; Mutikainen, Sara; Föhr, Tiina; Korhonen, Ilkka; Helander, Elina

    2017-03-01

    This study aimed to investigate in a real-life setting how moderate- and vigorous-intensity physical activity (PA) volumes differ according to absolute intensity recommendation and relative to individual fitness level by sex, age, and body mass index. A total of 23,224 Finnish employees (10,201 men and 13,023 women; ages 18-65 yr; body mass index = 18.5-40.0 kg·m) participated in heart rate recording for 2+ d. We used heart rate and its variability, respiration rate, and on/off response information from R-R interval data calibrated by participant characteristics to objectively determine daily PA volume, as follows: daily minutes of absolute moderate (3-<6 METs) and vigorous (≥6 METs) PA and minutes relative to individual aerobic fitness for moderate (40%-<60% of oxygen uptake reserve) and vigorous (≥60%) PA. According to absolute intensity categorization, the volume of both moderate- and vigorous-intensity PA was higher in men compared with women (P < 0.001), in younger compared with older participants (P < 0.001), and in normal weight compared with overweight or obese participants (P < 0.001). When the volume of PA intensity was estimated relative to individual fitness level, the differences were much smaller. Mean daily minutes of absolute vigorous-intensity PA were higher than those of relative intensity minutes in normal weight men ages 18-40 yr (17.7, 95% confidence interval [CI] = 16.9-18.6, vs 8.6, 95% CI = 8.0-9.1; P < 0.001), but the reverse was the case for obese women ages 41-65 yr (0.3, 95% CI = 0.2-0.4, vs 7.8, 95% CI = 7.2-8.4; P < 0.001). Compared with low-fit persons, high-fit persons more frequently reach an absolute target PA intensity, but reaching the target is more similar for relative intensity.

  19. Determination of absolute configuration of chiral molecules using vibrational optical activity: a review.

    PubMed

    He, Yanan; Wang, Bo; Dukor, Rina K; Nafie, Laurence A

    2011-07-01

    Determination of the absolute handedness, known as absolute configuration (AC), of chiral molecules is an important step in any field related to chirality, especially in the pharmaceutical industry. Vibrational optical activity (VOA) has become a powerful tool for the determination of the AC of chiral molecules in the solution state after nearly forty years of evolution. VOA offers a novel alternative, or supplement, to X-ray crystallography, permitting AC determinations on neat liquid, oil, and solution samples without the need to grow single crystals of the pure chiral sample molecules as required for X-ray analysis. By comparing the sign and intensity of the measured VOA spectrum with the corresponding ab initio density functional theory (DFT) calculated VOA spectrum of a chosen configuration, one can unambiguously assign the AC of a chiral molecule. Comparing measured VOA spectra with calculated VOA spectra of all the conformers can also provide solution-state conformational populations. VOA consists of infrared vibrational circular dichroism (VCD) and vibrational Raman optical activity (ROA). Currently, VCD is used routinely by researchers in a variety of backgrounds, including molecular chirality, asymmetric synthesis, chiral catalysis, drug screening, pharmacology, and natural products. Although the application of ROA in AC determination lags behind that of VCD, with the recent implementation of ROA subroutines in commercial quantum chemistry software, ROA will in the future complement VCD for AC determination. In this review, the basic principles of the application of VCD to the determination of absolute configuration in chiral molecules are described. The steps required for VCD spectral measurement and calculation are outlined, followed by brief descriptions of recently published papers reporting the determination of AC in small organic, pharmaceutical, and natural product molecules.

  20. A source for measurement of the absolute intensities of 226Ra gamma-radiation in equilibrium with decay products.

    PubMed

    Kharitonov, I A; Rasko, M A; Sepman, S V; Terechtchenko, E E; Hejdelman, A M

    2002-01-01

    The design and production techniques of a gamma-ray spectrometric source of 226Ra in equilibrium with its daughter decay products have been developed. The radon emanation coefficient of the source did not exceed 0.1%. The 226Ra activity in the gamma-ray spectrometric source was measured relative to that in an alpha-particle spectrometric source by comparison of the intensities of the main gamma rays using a semiconductor gamma-ray spectrometer. The total uncertainty of the activity measurement results was 0.5% for a coverage factor of k = 2.

  1. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K [Pleasanton, CA; Snyderman, Neal J [Berkeley, CA; Rowland, Mark S [Alamo, CA

    2012-05-15

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  2. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2010-07-13

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  3. Absolute exponential stability of recurrent neural networks with generalized activation function.

    PubMed

    Xu, Jun; Cao, Yong-Yan; Sun, Youxian; Tang, Jinshan

    2008-06-01

    In this paper, the recurrent neural networks (RNNs) with a generalized activation function class is proposed. In this proposed model, every component of the neuron's activation function belongs to a convex hull which is bounded by two odd symmetric piecewise linear functions that are convex or concave over the real space. All of the convex hulls are composed of generalized activation function classes. The novel activation function class is not only with a more flexible and more specific description of the activation functions than other function classes but it also generalizes some traditional activation function classes. The absolute exponential stability (AEST) of the RNN with a generalized activation function class is studied through three steps. The first step is to demonstrate the global exponential stability (GES) of the equilibrium point of original RNN with a generalized activation function being equivalent to that of RNN under all vertex functions of convex hull. The second step transforms the RNN under every vertex activation function into neural networks under an array of saturated linear activation functions. Because the GES of the equilibrium point of three systems are equivalent, the next stability analysis focuses on the GES of the equilibrium point of RNN system under an array of saturated linear activation functions. The last step is to study both the existence of equilibrium point and the GES of the RNN under saturated linear activation functions using the theory of M-matrix. In the end, a two-neuron RNN with a generalized activation function is constructed to show the effectiveness of our results.

  4. Responses of absolute and specific soil enzyme activities to long term additions of organic and mineral fertilizer.

    PubMed

    Zhang, Xinyu; Dong, Wenyi; Dai, Xiaoqin; Schaeffer, Sean; Yang, Fengting; Radosevich, Mark; Xu, Lili; Liu, Xiyu; Sun, Xiaomin

    2015-12-01

    Long-term phosphorus (P) and nitrogen (N) applications may seriously affect soil microbial activity. A long-term field fertilizer application trial was established on reddish paddy soils in the subtropical region of southern China in 1998. We assessed the effects of swine manure and seven different rates or ratios of NPK fertilizer treatments on (1) the absolute and specific enzyme activities per unit of soil organic carbon (SOC) or microbial biomass carbon (MBC) involved in C, N, and P transformations and (2) their relationships with soil environmental factors and soil microbial community structures. The results showed that manure applications led to increases in the absolute and specific activities of soil β-1,4-glucosidase(βG), β-1,4-N-acetylglucosaminidase (NAG), and leucine aminopeptidase (LAP). The absolute and specific acid phosphatase (AP) activities decreased as mineral P fertilizer application rates and ratios increased. Redundancy analysis (RDA) showed that there were negative correlations between absolute and specific AP activities, pH, and total P contents, while there were positive correlations between soil absolute and specific βG, NAG, and LAP enzyme activities, and SOC and total N contents. RDA showed that the contents of actinomycete and Gram-positive bacterium PLFA biomarkers are more closely related to the absolute and specific enzyme activities than the other PLFA biomarkers (P<0.01). Our results suggest that both the absolute and specific enzyme activities could be used as sensitive soil quality indicators that provide useful linkages with the microbial community structures and environmental factors. To maintain microbial activity and to minimize environmental impacts, P should be applied as a combination of inorganic and organic forms, and total P fertilizer application rates to subtropical paddy soils should not exceed 44 kg P ha(-1) year(-1).

  5. New ursane triterpenoids from Salvia urmiensis Bunge: Absolute configuration and anti-proliferative activity.

    PubMed

    Farimani, Mahdi Moridi; Bahadori, Mir Babak; Koulaei, Sheyda Ahmadi; Salehi, Peyman; Ebrahimi, Samad Nejad; Khavasi, Hamid Reza; Hamburger, Matthias

    2015-10-01

    Two new triterpenoids, urmiensolide B (1) and urmiensic acid (2), with rare carbon skeletons together with three known compounds were isolated from the aerial parts of Salvia urmiensis Bunge, an endemic species of Iran. The structures were established by a combination of 1D and 2D NMR, and HRESIMS, and in the case of 2 and 3, their structures were confirmed by single-crystal X-ray analysis. The absolute configuration of 2 was established by electronic circular dichroism (ECD) spectra. The new compounds were evaluated for their anti-proliferative activities against A549 and MCF-7 human cancer cell lines. Compounds 1 and 2 showed IC50 values of 2.8 and 1.6 μM against MCF-7 cells, respectively.

  6. Determination of the Absolute Number Concentration of Nanoparticles and the Active Affinity Sites on Their Surfaces.

    PubMed

    Wen, Cong-Ying; Tang, Man; Hu, Jiao; Wu, Ling-Ling; Pang, Dai-Wen; Zeng, Jing-Bin; Li, Xi-You

    2016-10-18

    Number concentration of nanoparticles is a critical and challenging parameter to be identified. Recently, gravimetric strategy is a fundamental method for absolute quantification, which is widely accepted and used by researchers, yet limited by the inaccuracy in measuring related parameters (e.g, density). Hence, we introduced isopycnic gradient centrifugation to determine the nanopartices' density and improved the current gravimetric method for more accuracy. In this work, polymer nanospheres were used as a model to validate this method. Through isopycnic gradient centrifugation, nanospheres finally reached the zone of equal density as them. By measuring the density of the medium solution in this zone, the nanospheres' density was identified. Then, the density was multiplied by the volume of a single nanosphere characterized by transmission electron microscopy (TEM), and the average weight of a single nanosphere was obtained. Using total weight of the nanospheres divided by the unit weight, their number concentration was quantified. Directly using the real density of the nanoparticles achieved more accurate quantification than the current gravimetric method which used the density of the bulk material counterparts for calculation. Besides, compared with the viscosity/light scattering method and the high-sensitivity flow cytometry (HSFCM) method (another two kinds of typical methods respectively based on light measurements and single particle counting), the improved gravimetric method showed better reproducibility and more convenience. Further, we modified the nanospheres with streptavidin (SA) and antibody, and through biorecognition interaction, we determined the amount of the active affinity sites on each biofunctional nanosphere. Moreover, their bioactivity in different storage conditions was monitored, which showed good stability even in PBS at 4 °C over one year. Our work provided a promising method for more accurately determining the absolute number

  7. Development of an Absolute Gas-Counting Capability for Low to Medium Activities

    SciTech Connect

    Williams, Richard M.; Aalseth, Craig E.; Ely, James H.; Day, Anthony R.; Hayes, James C.; Hoppe, Eric W.; LaFerriere, Brian D.; Mace, Emily K.; Merriman, Jason H.; Overman, Cory T.; Seifert, Allen

    2013-11-01

    ABSTRACT Pacific Northwest National Laboratory (PNNL) is developing a capability to measure the absolute activity concentration of various gaseous radionuclides using length-compensated proportional-counting methods. This capability will enable the validation and use of low-level, gaseous radionuclide calibration standards for use in PNNL’s shallow underground laboratory. Two sets of unequal length proportional counters have been fabricated. These detector assemblies operate on a static gas-fill principle, in contrast to continuous, flow-through configurations. One set of three counters has been fabricated using ultra-low background (ULB) electroformed copper and low-background fabrication methods. Once fully operational, these ULB counters will be used in PNNL’s shallow underground counting laboratory for analysis of gases with low activity concentrations < 1 Bq/cc. A second set of four unequal length counters has been fabricated from Oxygen-Free High-Conductivity Copper (OFHC) using similar low-background cleaning and assembly methods. These OFHC counters will be operated above ground in the analysis of gases with activity concentrations in the range of 1-10 Bq/cc. A gas delivery system is being developed to actively mix the analyte gas with an appropriate amount of count-gas and uniformly deliver it to the counters with high accuracy and repeatability. A description of both detector assemblies and gas delivery system will be given along with a preliminary uncertainty analysis of a simulated 0.05 Bq/cm3 gas measurement.

  8. Absolute Side-chain Structure at Position 13 Is Required for the Inhibitory Activity of Bromein*

    PubMed Central

    Sawano, Yoriko; Hatano, Ken-ichi; Miyakawa, Takuya; Tanokura, Masaru

    2008-01-01

    Bromelain isoinhibitor (bromein), a cysteine proteinase inhibitor from pineapple stem, has a unique double-chain structure. The bromein precursor protein includes three homologous inhibitor domains, each containing an interchain peptide between the light and heavy chains. The interchain peptide in the single-chain precursor is immediately processed by bromelain, a target proteinase. In the present study, to clarify the essential inhibitory site of bromein, we constructed 44 kinds of site-directed and deletion mutants and investigated the inhibitory activity of each toward bromelain. As a result, the complete chemical structure of Leu13 in the light chain was revealed to be essential for inhibition. Pro12 prior to the leucine residue was also involved in the inhibitory activity and would control the location of the leucine side chain by the fixed φ dihedral angle of proline. Furthermore, the five-residue length of the interchain peptide was strictly required for the inhibitory activity. On the other hand, no inhibitory activity against bromelain was observed by the substitution of proline for the N terminus residue Thr15 of the interchain peptide. In summary, these mutational analyses of bromein demonstrated that the appropriate position and conformation of Leu13 are absolutely crucial for bromelain inhibition. PMID:18948264

  9. Absolute side-chain structure at position 13 is required for the inhibitory activity of bromein.

    PubMed

    Sawano, Yoriko; Hatano, Ken-ichi; Miyakawa, Takuya; Tanokura, Masaru

    2008-12-26

    Bromelain isoinhibitor (bromein), a cysteine proteinase inhibitor from pineapple stem, has a unique double-chain structure. The bromein precursor protein includes three homologous inhibitor domains, each containing an interchain peptide between the light and heavy chains. The interchain peptide in the single-chain precursor is immediately processed by bromelain, a target proteinase. In the present study, to clarify the essential inhibitory site of bromein, we constructed 44 kinds of site-directed and deletion mutants and investigated the inhibitory activity of each toward bromelain. As a result, the complete chemical structure of Leu13 in the light chain was revealed to be essential for inhibition. Pro12 prior to the leucine residue was also involved in the inhibitory activity and would control the location of the leucine side chain by the fixed dihedral angle of proline. Furthermore, the five-residue length of the interchain peptide was strictly required for the inhibitory activity. On the other hand, no inhibitory activity against bromelain was observed by the substitution of proline for the N terminus residue Thr15 of the interchain peptide. In summary, these mutational analyses of bromein demonstrated that the appropriate position and conformation of Leu13 are absolutely crucial for bromelain inhibition.

  10. Behavioral studies on the enantiomers of butaclamol demonstrating absolute optical specificity for neuroleptic activity.

    PubMed

    Voith, K; Cummings, J R

    1976-08-01

    Butaclamol is a member of a new chemical class for which antipsychotic activity in humans has been demonstrated. Butaclamol, a racemate, has been resolved into its optical isomers and a separation of activities was found to occur between the (+) and (-) enantiomers. The present experiments show that at doses ranging from 0.1 to 0.3 mg/kg the (+) enantiomer abolished amphetamine-induced (a) stereotyped behavior and (b) rotational behavior in rats with unilateral lesions in the substantia nigra. It also inhibited the lever-pressing response in the continuous (Sidman) avoidance procedure, blocked discriminated avoidance behavior, and decreased ambulation and rearing in the open field. In contrast, the (-) enantiomer was devoid of behavioral activity at 100-500 times larger doses. At considerably higher doses (+)-butaclamol antagonized epinephrine-induced mortality. Again, the (-)-butaclamol was devoid of this activity as well. The significance of absolute optical specifity manifested by a neuroleptic drug is discussed in the light of dopaminergic and adrenergic mechanisms.

  11. Evaluation of activity through dynamic laser speckle using the absolute value of the differences

    NASA Astrophysics Data System (ADS)

    Braga, R. A.; Nobre, C. M. B.; Costa, A. G.; Sáfadi, T.; da Costa, F. M.

    2011-01-01

    When a material is illuminated with a laser beam, it is possible to verify a phenomenon known as dynamic speckle or biospeckle. It exhibits an interference image that contains lots of information about the process being analyzed, and one of its most important applications is determining the activity quantity from the materials under study. The numerical analysis of the dynamic speckle images can be carried out by means of a co-occurrence matrix (COM) that assembles the intensity distributions of a speckle pattern with regard to time. An operational method that is widely used on the biospeckle COMs is the inertia moment (IM). Some studies demonstrate that IM is more sensitive on analyzing processes that involve high activities or high frequencies if considering the spectral analysis of the phenomena. However, when this variation is not so intense, this method is less efficient. For low variations on the activity or low frequencies, qualitative methods such as wavelet based entropy and cross-spectrum analysis have presented better results; however, processes that are in the intermediate range of activity are not well covered for any of these techniques mentioned earlier. The contribution of this research is to present an alternative approach, based on the absolute value of the differences (AVD) when handling the biospeckle COM. By using AVD on the seed-drying process, was found that it is efficient on verifying the behavior of the intermediate frequencies. Accumulated sum test (Coates and Diggle) showed that AVD and IM are generated from the same stochastic process. Thus, AVD is useful as an alternative method in some cases or even as a complementary tool for analyzing the dynamic speckle, mainly when the information of the activity is not present on high frequencies.

  12. Absolute Configurations and NO Inhibitory Activities of Terpenoids from Curcuma longa.

    PubMed

    Xu, Jing; Ji, Feifei; Kang, Jing; Wang, Hao; Li, Shen; Jin, Da-Qing; Zhang, Qiang; Sun, Hongwei; Guo, Yuanqiang

    2015-06-24

    Curcuma longa L., belonging to the Zingiberaceae family, is a perennial herb and has been used as a spice and a pigment in the food industry. In the ongoing search for inhibitory reagents of NO production and survey of the chemical composition of natural vegetable foods, the chemical constituents of C. longa used as spice were investigated. This investigation resulted in the isolation of 2 new terpenoids and 14 known analogues. Their structures were established on the basis of the extensive analyses of 1D and 2D NMR spectroscopic data, and the absolute configurations of 1-4 were elucidated by comparison of the calculated and experimental ECD spectra. Among them, compound 1 is a rare norditerpene with an ent-labdane skeleton, and 2 is a skeletally novel sesquiterpene having an eight-membered ring. All of the compounds were found to possess NO inhibitory activities in murine microglial BV-2 cells. The discovery of two new compounds in this chemical investigation further disclosed the chemical composition of C. longa used a food spice, and the bioassay implied that the natural food spice C. longa, containing terpenoids with NO inhibitory activities, may be potentially promotive to human health.

  13. Labdane Diterpenoids from Salvia leriifolia: Absolute Configuration, Antimicrobial and Cytotoxic Activities.

    PubMed

    Farimani, Mahdi Moridi; Taleghani, Akram; Aliabadi, Abbas; Aliahmadi, Atousa; Esmaeili, Mohammad Ali; Namazi Sarvestani, Nazanin; Khavasi, Hamid Reza; Smieško, Martin; Hamburger, Matthias; Nejad Ebrahimi, Samad

    2016-09-01

    Fractionation of an n-hexane extract of the aerial parts of Salvia leriifolia led to the isolation of two new (1, 2) and two known (3, 4) labdane diterpenoids, together with three other known compounds. The structures were established by a combination of 1D and 2D NMR, and HRESIMS. The structures of 1 and 3 were confirmed by single-crystal X-ray analysis. The absolute configuration of 1-4 was established by electronic circular dichroism spectroscopy. Compounds 1-4 were evaluated for their cytotoxic activities against MCF-7 human breast cancer cells. Labdanes 3 and 4 were additionally tested against MDA-MB231 human breast cancer and DU-145 human prostate cancer cell lines. Compound 4 showed IC50 values of 25, 50, and 50 µM against MCF-7, MDA-MB231, and DU-145 cells, respectively. Compounds 1-4 were tested for activity against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria. Compound 3 showed an MIC of 213 µM against methicillin-resistant S. aureus.

  14. Cadinane-Type Sesquiterpenoids from Heterotheca inuloides: Absolute Configuration and Anti-inflammatory Activity.

    PubMed

    Egas, Verónica; Toscano, Rubén A; Linares, Edelmira; Bye, Robert; Espinosa-García, Francisco J; Delgado, Guillermo

    2015-11-25

    Eight cadinane-type sesquiterpenoids (1-8) together with some triterpenoids, flavonoids, and sterols were isolated from the aerial parts of Heterotheca inuloides. The structures of the new compounds (1-4) were elucidated on the basis of extensive 1D and 2D NMR spectroscopic data analysis. The structures of the new (1-3) and the known (5-7) sesquiterpenoids were confirmed by X-ray crystallography. The absolute configurations of metabolites 2-5 were determined by comparing their experimental and calculated electronic circular dichroism spectra and confirmed via refinement of the Flack parameter using anomalous X-ray scattering from the oxygen atoms and chemical correlation methods. The sesquiterpenoids were evaluated for their anti-inflammatory potential by applying the TPA-induced mouse ear edema model. The results revealed that some of these metabolites exhibit moderate anti-inflammatory activity. At a dose of 228 μg/ear compound 1 showed 43.14 ± 8.09% inhibition on ear edema, indicating an IC50 > 228 μg/ear.

  15. Absolute height measurement of specular surfaces with modified active fringe reflection photogrammetry

    NASA Astrophysics Data System (ADS)

    Ren, Hongyu; Jiang, Xiangqian; Gao, Feng; Zhang, Zonghua

    2014-07-01

    Deflectometric methods have been studied for more than a decade for slope measurement of specular freeform surfaces through utilization of the deformation of a sample pattern after reflection from a tested sample surface. Usually, these approaches require two-directional fringe patterns to be projected on a LCD screen or ground glass and require slope integration, which leads to some complexity for the whole measuring process. This paper proposes a new mathematical measurement model for measuring topography information of freeform specular surfaces, which integrates a virtual reference specular surface into the method of active fringe reflection photogrammetry and presents a straight-forward relation between height of the tested surface and phase signals. This method only requires one direction of horizontal or vertical sinusoidal fringe patterns to be projected from a LCD screen, resulting in a significant reduction in capture time over established methods. Assuming the whole system has been precalibrated during the measurement process, the fringe patterns are captured separately via the virtual reference and detected freeform surfaces by a CCD camera. The reference phase can be solved according to the spatial geometric relation between the LCD screen and the CCD camera. The captured phases can be unwrapped with a heterodyne technique and optimum frequency selection method. Based on this calculated unwrapped-phase and that proposed mathematical model, absolute height of the inspected surface can be computed. Simulated and experimental results show that this methodology can conveniently calculate topography information for freeform and structured specular surfaces without integration and reconstruction processes.

  16. Anti-hepatitis B virus activities and absolute configurations of sesquiterpenoid glycosides from Phyllanthus emblica.

    PubMed

    Lv, Jun-Jiang; Wang, Ya-Feng; Zhang, Jing-Min; Yu, Shan; Wang, Dong; Zhu, Hong-Tao; Cheng, Rong-Rong; Yang, Chong-Ren; Xu, Min; Zhang, Ying-Jun

    2014-11-21

    During the process exploring anti-viral compounds from Phyllanthus species, eight new highly oxygenated bisabolane sesquiterpenoid glycoside phyllaemblicins G1–G8 (1–8) were isolated from Phyllanthus emblica, along with three known compounds, phyllaemblicin F (9), phyllaemblic acid (10) and glochicoccin D (11). Phyllaemblicin G2 (2), bearing a tricyclo [3.1.1.1] oxygen bridge ring system, is an unusual sesquiterpenoid glycoside, while phyllaemblicins G6–G8 (6–8) are dimeric sesquiterpenoid glycosides with two norbisabolane units connecting through a disaccharide. All the structures were elucidated by the extensive analysis of HRMS and NMR data. The relative configuration of phyllaemblicin G2 was constructed based on heteronuclear coupling constants measurement, and the absolute configurations for all new compounds were established by calculated electronic circular dichroism (ECD) using time dependent density functional theory. The sesquiterpenoid glycoside dimers 6–9 displayed potential anti-hepatitis B virus (HBV) activities, especially for the new compound 6 with IC50 of 8.53 ± 0.97 and 5.68 ± 1.75 μM towards the HBV surface antigen (HBsAg) and HBV excreted antigen (HBeAg) secretion, respectively.

  17. Absolute density measurements of ammonia produced via plasma-activated catalysis

    NASA Astrophysics Data System (ADS)

    Vankan, P.; Rutten, T.; Mazouffre, S.; Schram, D. C.; Engeln, R.

    2002-07-01

    The generation of ammonia from atomic hydrogen and nitrogen has been demonstrated by means of cavity enhanced absorption spectroscopy. The atomic species are produced in a thermal plasma source in which plasma is created from mixtures of hydrogen and nitrogen. It is shown that for large atomic flux conditions, 2% of the hydrogen and nitrogen can be converted to ammonia. The process in which the ammonia molecules are formed from atomic radicals at the fully covered surface is called plasma-activated catalysis.

  18. Exploring a Black Body Source as an Absolute Radiometric Calibration Standard and Comparison with a NIST Traced Lamp Standard

    NASA Technical Reports Server (NTRS)

    Green, Robert O.; Chrien, Thomas; Sarture, Chuck

    2001-01-01

    Radiometric calibration of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) is required for the scientific research and application objectives pursued with the spectroscopic measurements. Specifically calibration is required for: inter-comparison of AVIRIS data measured at different locations and at different times; analysis of AVIRIS data with data measured by other instruments; and analysis of AVIRIS data in conjunction with computer models. The primary effect of radiometric calibration is conversion of AVIRIS instrument response values (digitized numbers, or DN) to units of absolute radiance. For example, a figure shows the instrument response spectrum measured by AVIRIS over a portion of Rogers Dry Lake, California, and another figure shows the same spectrum calibrated to radiance. Only the calibrated spectrum may be quantitatively analyzed for science research and application objectives. Since the initial development of the AVIRIS instrument-radiometric calibration has been based upon a 1000-W irradiance lamp with a calibration traced to the National Institute of Standards and Technology (NIST). There are several advantages to this irradiance-lamp calibration approach. First, the considerable effort of NIST backs up the calibration. Second, by changing the distance to the lamp, the output can closely span the radiance levels measured by AVIRIS. Third, this type of standard is widely used. Fourth, these calibrated lamps are comparatively inexpensive. Conversely, there are several disadvantages to this approach as well. First, the lamp is not a primary standard. Second, the lamp output characteristics may change in an unknown manner through time. Third, it is difficult to assess, constrain, or improve the calibration uncertainty delivered with the lamp. In an attempt to explore the effect and potentially address some of these disadvantages a set of analyses and measurements comparing an irradiance lamp with a black-body source have been completed

  19. Absolute and relative emission spectroscopy study of 3 cm wide planar radio frequency atmospheric pressure bio-plasma source

    SciTech Connect

    Deng, Xiaolong; Nikiforov, Anton Yu Leys, Christophe; Ionita, Eusebiu-Rosini; Dinescu, Gheorghe

    2015-08-03

    The dynamics of low power atmospheric pressure radio frequency discharge generated in Ar gas in long gap of 3 cm is investigated. This plasma source is characterized and analyzed for possible large scale biomedical applications where low gas temperature and potential-less effluent are required. The discharge forms a homogenous glow-like afterglow in ambient air at input power of 30 W with low gas temperature of 330 K, which is desirable in biomedical applications. With absolute calibrated spectroscopy of the discharge, electron density of 0.4 × 10{sup 18} m{sup −3} and electron temperature of 1.5 eV are obtained from continuum Bremsstrahlung radiation of the source. Time and spatial resolved emission spectroscopy is used to analyze discharge generation mechanism and active species formation. It is found that discharge dynamics strongly correlates with the discharge current waveform. Strong Ar(2p) excited states emission is observed nearby the electrodes surface on a distance up to 200 μm in the plasma sheath region at 10 ns after the current peak, whereas OH(A) emission is uniform along of the interelectrode gap.

  20. Muscle Activation During Exercise in Severe Acute Hypoxia: Role of Absolute and Relative Intensity

    PubMed Central

    Torres-Peralta, Rafael; Losa-Reyna, José; González-Izal, Miriam; Perez-Suarez, Ismael; Calle-Herrero, Jaime; Izquierdo, Mikel

    2014-01-01

    Abstract Torres-Peralta, Rafael, José Losa-Reyna, Miriam González-Izal, Ismael Perez-Suarez, Jaime Calle-Herrero, Mikel Izquierdo, and José A.L. Calbet. Muscle activation during exercise in severe acute hypoxia: Role of absolute and relative intensity. High Alt Med Biol 15:472–482, 2014.—The aim of this study was to determine the influence of severe acute hypoxia on muscle activation during whole body dynamic exercise. Eleven young men performed four incremental cycle ergometer tests to exhaustion breathing normoxic (FIo2=0.21, two tests) or hypoxic gas (FIo2=0.108, two tests). Surface electromyography (EMG) activities of rectus femoris (RF), vastus medialis (VL), vastus lateralis (VL), and biceps femoris (BF) were recorded. The two normoxic and the two hypoxic tests were averaged to reduce EMG variability. Peak Vo2 was 34% lower in hypoxia than in normoxia (p<0.05). The EMG root mean square (RMS) increased with exercise intensity in all muscles (p<0.05), with greater effect in hypoxia than in normoxia in the RF and VM (p<0.05), and a similar trend in VL (p=0.10). At the same relative intensity, the RMS was greater in normoxia than in hypoxia in RF, VL, and BF (p<0.05), with a similar trend in VM (p=0.08). Median frequency increased with exercise intensity (p<0.05), and was higher in hypoxia than in normoxia in VL (p<0.05). Muscle contraction burst duration increased with exercise intensity in VM and VL (p<0.05), without clear effects of FIo2. No significant FIo2 effects on frequency domain indices were observed when compared at the same relative intensity. In conclusion, muscle activation during whole body exercise increases almost linearly with exercise intensity, following a muscle-specific pattern, which is adjusted depending on the FIo2 and the relative intensity of exercise. Both VL and VM are increasingly involved in power output generation with the increase of intensity and the reduction in FIo2. PMID:25225839

  1. Yeast AMP-activated protein kinase monitors glucose concentration changes and absolute glucose levels.

    PubMed

    Bendrioua, Loubna; Smedh, Maria; Almquist, Joachim; Cvijovic, Marija; Jirstrand, Mats; Goksör, Mattias; Adiels, Caroline B; Hohmann, Stefan

    2014-05-02

    Analysis of the time-dependent behavior of a signaling system can provide insight into its dynamic properties. We employed the nucleocytoplasmic shuttling of the transcriptional repressor Mig1 as readout to characterize Snf1-Mig1 dynamics in single yeast cells. Mig1 binds to promoters of target genes and mediates glucose repression. Mig1 is predominantly located in the nucleus when glucose is abundant. Upon glucose depletion, Mig1 is phosphorylated by the yeast AMP-activated kinase Snf1 and exported into the cytoplasm. We used a three-channel microfluidic device to establish a high degree of control over the glucose concentration exposed to cells. Following regimes of glucose up- and downshifts, we observed a very rapid response reaching a new steady state within less than 1 min, different glucose threshold concentrations depending on glucose up- or downshifts, a graded profile with increased cell-to-cell variation at threshold glucose concentrations, and biphasic behavior with a transient translocation of Mig1 upon the shift from high to intermediate glucose concentrations. Fluorescence loss in photobleaching and fluorescence recovery after photobleaching data demonstrate that Mig1 shuttles constantly between the nucleus and cytoplasm, although with different rates, depending on the presence of glucose. Taken together, our data suggest that the Snf1-Mig1 system has the ability to monitor glucose concentration changes as well as absolute glucose levels. The sensitivity over a wide range of glucose levels and different glucose concentration-dependent response profiles are likely determined by the close integration of signaling with the metabolism and may provide for a highly flexible and fast adaptation to an altered nutritional status.

  2. Yeast AMP-activated Protein Kinase Monitors Glucose Concentration Changes and Absolute Glucose Levels*

    PubMed Central

    Bendrioua, Loubna; Smedh, Maria; Almquist, Joachim; Cvijovic, Marija; Jirstrand, Mats; Goksör, Mattias; Adiels, Caroline B.; Hohmann, Stefan

    2014-01-01

    Analysis of the time-dependent behavior of a signaling system can provide insight into its dynamic properties. We employed the nucleocytoplasmic shuttling of the transcriptional repressor Mig1 as readout to characterize Snf1-Mig1 dynamics in single yeast cells. Mig1 binds to promoters of target genes and mediates glucose repression. Mig1 is predominantly located in the nucleus when glucose is abundant. Upon glucose depletion, Mig1 is phosphorylated by the yeast AMP-activated kinase Snf1 and exported into the cytoplasm. We used a three-channel microfluidic device to establish a high degree of control over the glucose concentration exposed to cells. Following regimes of glucose up- and downshifts, we observed a very rapid response reaching a new steady state within less than 1 min, different glucose threshold concentrations depending on glucose up- or downshifts, a graded profile with increased cell-to-cell variation at threshold glucose concentrations, and biphasic behavior with a transient translocation of Mig1 upon the shift from high to intermediate glucose concentrations. Fluorescence loss in photobleaching and fluorescence recovery after photobleaching data demonstrate that Mig1 shuttles constantly between the nucleus and cytoplasm, although with different rates, depending on the presence of glucose. Taken together, our data suggest that the Snf1-Mig1 system has the ability to monitor glucose concentration changes as well as absolute glucose levels. The sensitivity over a wide range of glucose levels and different glucose concentration-dependent response profiles are likely determined by the close integration of signaling with the metabolism and may provide for a highly flexible and fast adaptation to an altered nutritional status. PMID:24627493

  3. Determination of the Absolute Number of Cytokine mRNA Molecules within Individual Activated Human T Cells

    NASA Technical Reports Server (NTRS)

    Karr, Laurel J.; Marshall, Gwen; Hockett, Richard D.; Bucy, R. Pat; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    A primary function of activated T cells is the expression and subsequent secretion of cytokines, which orchestrate the differentiation of other lymphocytes, modulate antigen presenting cell activity, and alter vascular endothelium to mediate an immune response. Since many features of immune regulation probably result from modest alterations of endogenous rates of multiple interacting processes, quantitative analysis of the frequency and specific activity of individual T cells is critically important. Using a coordinated set of quantitative methods, the absolute number of molecules of several key cytokine mRNA species in individual T cells has been determined. The frequency of human blood T cells activated in vitro by mitogens and recall protein antigens was determined by intracellular cytokine protein staining, in situ hybridization for cytokine mRNA, and by limiting dilution analysis for cytokine mRNA+ cells. The absolute number of mRNA molecules was simultaneously determined in both homogenates of the entire population of cells and in individual cells obtained by limiting dilution, using a quantitative, competitive RT-PCR assay. The absolute numbers of mRNA molecules in a population of cells divided by the frequency of individual positive cells, yielded essentially the same number of mRNA molecules per cell as direct analysis of individual cells by limiting dilution analysis. Mean numbers of mRNA per positive cell from both mitogen and antigen activated T cells, using these stimulation conditions, were 6000 for IL-2, 6300 for IFN-gamma, and 1600 for IL-4.

  4. Determination of the Absolute Number of Cytokine mRNA Molecules within Individual Activated Human T Cells

    NASA Technical Reports Server (NTRS)

    Karr, Laurel J.; Marshall, Gwen; Hockett, Richard D.; Bucy, R. Pat; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    A primary function of activated T cells is the expression and subsequent secretion of cytokines, which orchestrate the differentiation of other lymphocytes, modulate antigen presenting cell activity, and alter vascular endothelium to mediate an immune response. Since many features of immune regulation probably result from modest alterations of endogenous rates of multiple interacting processes, quantitative analysis of the frequency and specific activity of individual T cells is critically important. Using a coordinated set of quantitative methods, the absolute number of molecules of several key cytokine mRNA species in individual T cells has been determined. The frequency of human blood T cells activated in vitro by mitogens and recall protein antigens was determined by intracellular cytokine protein staining, in situ hybridization for cytokine mRNA, and by limiting dilution analysis for cytokine mRNA+ cells. The absolute number of mRNA molecules was simultaneously determined in both homogenates of the entire population of cells and in individual cells obtained by limiting dilution, using a quantitative, competitive RT-PCR assay. The absolute numbers of mRNA molecules in a population of cells divided by the frequency of individual positive cells, yielded essentially the same number of mRNA molecules per cell as direct analysis of individual cells by limiting dilution analysis. Mean numbers of mRNA per positive cell from both mitogen and antigen activated T cells, using these stimulation conditions, were 6000 for IL-2, 6300 for IFN-gamma, and 1600 for IL-4.

  5. Absolute measurements of short-pulse, long-pulse, and capsule-implosion backlighter sources at x-ray energies greater than 10 keV

    NASA Astrophysics Data System (ADS)

    Maddox, Brian

    2010-11-01

    Laser-generated x-ray backlighters with x-ray energies > 10 keV are becoming essential diagnostic tools for many high energy density experiments. Examples include studies of high areal density cores for ignition designs, mid- to high-Z capsule implosion experiments, absolute equation of state experiments, dynamic diffraction under extreme pressures, and the study of material strength. Significant progress has been made recently using short pulse lasers, coupled to metal foil targets [1], and imploding capsules for producing high energy backlighters. Measuring the absolute x-ray flux and spectra from these sources is required for quantitative analysis of experimental data and for the design and planning of future experiments. We have performed an extensive series of experiments to measure the absolute x-ray flux and spectra on the Titan, Omega, Omega-EP, and NIF laser systems, employing single-photon-counting detectors, crystal spectrometers, and multichannel differential filtering (Ross-pair) and filter stack bremsstrahlung spectrometers. Calibrations were performed on these instruments [2] enabling absolute measurements of backlighter spectra to be made from 10 keV to 1 MeV. Various backlighter techniques that generate either quasi-monochromatic sources or broadband continuum sources will be presented and compared. For Molybdenum Kα backlighters at x-ray energy of ˜17 keV we measure conversion efficiencies of 1.3x10-4 using 1 μm wavelength short-pulse lasers at an intensity of ˜1x10^17 W/cm^2. This is a factor of ˜2 high than using 0.3 μm wavelength long-pulse lasers at an intensity of ˜1x10^16 W/cm^2. Other types of backlighter targets include capsule implosion backlighters that can generate a very bright ``white-light'' continuum x-ray source and high-Z gas filled capsules that generate a quasi-line-source of x rays. We will present and compare the absolute laser energy to x-ray conversion efficiencies for these different backlighter techniques and give

  6. CMBACT: CMB from ACTive sources

    NASA Astrophysics Data System (ADS)

    Pogosian, Levon; Vachaspati, Tanmay

    2011-06-01

    This code is based on the cosmic string model described in this paper by Pogosian and Vachaspati, as well as on the CMBFAST code created by Uros Seljak and Matias Zaldarriaga. It contains an integrator for the vector contribution to the CMB temperature and polarization. The code is reconfigured to make it easier to use with or without active sources. To produce inflationary CMB spectra one simply sets the string tension to zero (gmu=0.0d0). For a non-zero value of tension only the string contribution is calculated. An option is added to randomize the directions of velocities of consolidated segments as they evolve in time. In the original segment model, which is still the default version (irandomv=0), each segment is given a random velocity initially, but then continues to move in a straight line for the rest of its life. The new option (irandomv=1) allows to additionally randomize velocities of each segment at roughly each Hubble time. However, the merits of this new option are still under investigation. The default version (irandomv=0) is strongly recommended, since it actually gives reasonable unequal time correlators. For each Fourier mode, k, the string stress-energy components are now evaluated on a time grid sufficiently fine for that k.

  7. Non-invasive quantification of absolute cerebral blood volume during functional activation applicable to the whole human brain.

    PubMed

    Ciris, Pelin Aksit; Qiu, Maolin; Constable, Robert Todd

    2014-02-01

    Cerebral blood volume (CBV) changes in many diverse pathologic conditions, and in response to functional challenges along with changes in blood flow, blood oxygenation, and the cerebral metabolic rate of oxygen. The feasibility of a new method for non-invasive quantification of absolute cerebral blood volume that can be applicable to the whole human brain was investigated. Multi-slice data were acquired at 3 T using a novel inversion recovery echo planar imaging (IR-EPI) pulse sequence with varying contrast weightings and an efficient rotating slice acquisition order, at rest and during visual activation. A biophysical model was used to estimate absolute cerebral blood volume at rest and during activation, and oxygenation during activation, on data from 13 normal human subjects. Cerebral blood volume increased by 21.7% from 6.6 ± 0.8 mL/100 mL of brain parenchyma at rest to 8.0 ± 1.3 mL/100 mL of brain parenchyma in the occipital cortex during visual activation, with average blood oxygenation of 84 ± 2.1% during activation, comparing well with literature. The method is feasible, and could foster improved understanding of the fundamental physiological relationship between neuronal activity, hemodynamic changes, and metabolism underlying brain activation; complement existing methods for estimating compartmental changes; and potentially find utility in evaluating vascular health. Copyright © 2013 Wiley Periodicals, Inc.

  8. Angle-resolved absolute out-of-band radiation studies of a tin-based laser-produced plasma source

    SciTech Connect

    Morris, O.; Hayden, P.; O'Reilly, F.; Murphy, N.; Dunne, P.; Bakshi, V.

    2007-08-20

    Out-of-band radiation emitted from an extreme ultraviolet laser-produced plasma, formed on a solid tin target, was measured over several angles between 25 deg. and 85 deg. with respect to the target normal for six energy bands between 200 and 1000 nm. The optical and target system was rotated with respect to the detector and the intensity of the radiation was measured using an absolutely calibrated filter/photodiode combination. The emission was dominated by radiation in the 214 nm band. A cosine function fitted to the angular distribution of the total radiation yielded an exponent of 0.23{+-}0.02.

  9. Absolute measurement of activity of ¹⁹⁸Au foils using the 4πβ-γ coincidence counting method and corrections by the Monte Carlo simulation.

    PubMed

    Nishiyama, Jun; Harano, Hideki; Matsumoto, Tetsuro; Sato, Yasushi; Uritani, Akira; Kudo, Katsuhisa

    2012-01-01

    The thermal neutron fluence rate is determined by the gold activation method. The absolute activity of the irradiated gold foil is measured by a 4πβ-γ coincidence counter. Using this method, corrections for the detection of conversion electrons and gamma rays by a 4πβ counter are very important to obtain accurate absolute activity. In this work, Monte Carlo simulations were performed to derive the correction factor K. The absolute measurement of (198)Au activity for 20-100 μm thickness Au foils were performed to verify the calculating model of the 4πβ-γ coincidence counting system.

  10. Absolute Zero

    NASA Astrophysics Data System (ADS)

    Donnelly, Russell J.; Sheibley, D.; Belloni, M.; Stamper-Kurn, D.; Vinen, W. F.

    2006-12-01

    Absolute Zero is a two hour PBS special attempting to bring to the general public some of the advances made in 400 years of thermodynamics. It is based on the book “Absolute Zero and the Conquest of Cold” by Tom Shachtman. Absolute Zero will call long-overdue attention to the remarkable strides that have been made in low-temperature physics, a field that has produced 27 Nobel Prizes. It will explore the ongoing interplay between science and technology through historical examples including refrigerators, ice machines, frozen foods, liquid oxygen and nitrogen as well as much colder fluids such as liquid hydrogen and liquid helium. A website has been established to promote the series: www.absolutezerocampaign.org. It contains information on the series, aimed primarily at students at the middle school level. There is a wealth of material here and we hope interested teachers will draw their student’s attention to this website and its substantial contents, which have been carefully vetted for accuracy.

  11. Determination of the absolute photoionization cross sections of CH3 and I produced from a pyrolysis source, by combined synchrotron and vacuum ultraviolet laser studies.

    PubMed

    Gans, Bérenger; Vieira Mendes, Luiz A; Boyé-Péronne, Séverine; Douin, Stéphane; Garcia, Gustavo; Soldi-Lose, Héloïse; Cunha de Miranda, Barbara K; Alcaraz, Christian; Carrasco, Nathalie; Pernot, Pascal; Gauyacq, Dolores

    2010-03-11

    A pyrolysis source coupled to a supersonic expansion has been used to produce the CH3 radical from two precursors, iodomethane CH3I and nitromethane CH3NO2. The relative ionization yield of CH3 has been recorded at the SOLEIL Synchrotron Radiation source in the range 9.0-11.6 eV, and its ionization threshold has been modeled by taking into account the vibrational and rotational temperature of the radical in the molecular beam. The relative photoionization yield has been normalized to an absolute cross section scale at a fixed wavelength (118.2 nm, sigma(i)(CH3) = 6.7(-1.8)(+2.4) Mb, 95% confidence interval) in an independent laboratory experiment using the same pyrolysis source, a vacuum ultraviolet (VUV) laser, and a carefully calibrated detection chain. The resulting absolute cross section curve is in good agreement with the recently published measurements by Taatjes et al., although with an improved signal-to-noise ratio. The absolute photoionization cross section of CH3I at 118.2 nm has also been measured to be sigma(i)(CH3I) = (48.2 +/- 7.9) Mb, in good agreement with previous electron impact measurements. Finally, the photoionization yield of the iodine atom in its ground state 2P(3/2) has been recorded using the synchrotron source and calibrated for the first time on an absolute cross section scale from our fixed 118.2 nm laser measurement, sigma(i)(I2P(3/2)) = 74(-23)(+33) Mb (95% confidence interval). The ionization curve of atomic iodine is in good agreement, although with slight variations, with the earlier relative ionization yield measured by Berkowitz et al. and is also compared to an earlier calculation of the iodine cross section by Robicheaux and Greene. It is demonstrated that, in the range of pyrolysis temperature used in this work, all the ionization cross sections are temperature-independent. Systematic care has been taken to include all uncertainty sources contributing to the final confidence intervals for the reported results.

  12. Method of excess fractions with application to absolute distance metrology: wavelength selection and the effects of common error sources.

    PubMed

    Falaggis, Konstantinos; Towers, David P; Towers, Catherine E

    2012-09-20

    Multiwavelength interferometry (MWI) is a well established technique in the field of optical metrology. Previously, we have reported a theoretical analysis of the method of excess fractions that describes the mutual dependence of unambiguous measurement range, reliability, and the measurement wavelengths. In this paper wavelength, selection strategies are introduced that are built on the theoretical description and maximize the reliability in the calculated fringe order for a given measurement range, number of wavelengths, and level of phase noise. Practical implementation issues for an MWI interferometer are analyzed theoretically. It is shown that dispersion compensation is best implemented by use of reference measurements around absolute zero in the interferometer. Furthermore, the effects of wavelength uncertainty allow the ultimate performance of an MWI interferometer to be estimated.

  13. QSAR of molecular structure and cytotoxic activity of vitamin K2 derivatives with concept of absolute hardness.

    PubMed

    Ishihara, Mariko; Sakagami, Hiroshi

    2007-01-01

    The correlation between the cytotoxicity of seven vitamin K2 (menaquinone) derivatives and thirteen chemical descriptors determined by CONFLEX5/CAChe Worksystem 4.9 (PM3) was investigated. After determination of the conformation of the seven vitamin K2 derivatives and approximation to the molecular form present in vivo (biomimetic) by CONFLEX5, the most stable structure was then determined by CAChe Worksystem 4.9 MOPAC (PM3). The vitamin K2 derivatives with one to three isoprenyl units [1-3] showed an extended form, whereas those with four to seven isoprenyl units [4-7] displayed a spherical form. The human hepatocellular carcinoma HepG2 cells displayed a good correlation between cytotoxicity and all the descriptors except for the electron affinity and lowest unoccupied molecular orbital energy (E(LUMO)). The absolute hardness (eta)--absolute electron negativity (chi) activity diagram determined by this calculation method may be useful for estimating the cytotoxic activity of vitamin K2 derivatives against HepG2 cells. The human squamous cell carcinoma HSC-2 and HSC-3 cells showed similar correlation. The human promyleocytic leukemia HL-60 cells showed the good correlation between cytotoxicity and molecular length. The present study demonstrates for the first time the best correlation between cytotoxic activity and molecular shape or molecular weight of vitamin K2 derivatives, regardless of the type of target cells.

  14. An absolute radon 222 activity measurement system at LNE-LNHB.

    PubMed

    Sabot, B; Pierre, S; Cassette, P

    2016-12-01

    A good metrological traceability of radon and progenies is necessary to accurately measure the radon concentration. In 1995, at the LNE-LNHB, J.L. Picolo developed a reference method using a defined-solid-angle (DSA) alpha spectrometer to measure a frozen radon source. With this method it was possible to measure radon standards with a relative standard uncertainty of 0.5%. This paper presents the design and the characterization of a new upgraded measurement system; all parameters and their uncertainties are discussed. This new system allows the measurement of radon sources from 100Bq to 4MBq with a relative standard uncertainty of 0.3%.

  15. Synthesis, absolute configuration and conformation of optically active 1,2-homoheptafulvalene.

    PubMed

    Ito, Shunji; Kurita, Mitsuhiro; Kikuchi, Sigeru; Asao, Toyonobu; Ito, Yoshitora; Oda, Masaji; Sotokawa, Hideo; Tajiri, Akio; Morita, Noboru

    2003-02-07

    An optically active 1,2-homoheptafulvalene was successfully synthesized and subjected to spectroscopic investigation. The cycloaddition of the optically active hydrocarbon with tetracyanoethylene (TCNE) and 4-phenyl-1,2,4-triazoline-3,5-dione(PTAD) gave a [4 + 2] cycloadduct and a mixture of [8 + 2] cycloadducts, respectively, which are both optically active.

  16. Absolute Summ

    NASA Astrophysics Data System (ADS)

    Phillips, Alfred, Jr.

    Summ means the entirety of the multiverse. It seems clear, from the inflation theories of A. Guth and others, that the creation of many universes is plausible. We argue that Absolute cosmological ideas, not unlike those of I. Newton, may be consistent with dynamic multiverse creations. As suggested in W. Heisenberg's uncertainty principle, and with the Anthropic Principle defended by S. Hawking, et al., human consciousness, buttressed by findings of neuroscience, may have to be considered in our models. Predictability, as A. Einstein realized with Invariants and General Relativity, may be required for new ideas to be part of physics. We present here a two postulate model geared to an Absolute Summ. The seedbed of this work is part of Akhnaton's philosophy (see S. Freud, Moses and Monotheism). Most important, however, is that the structure of human consciousness, manifest in Kenya's Rift Valley 200,000 years ago as Homo sapiens, who were the culmination of the six million year co-creation process of Hominins and Nature in Africa, allows us to do the physics that we do. .

  17. Impact of Absolute Stereochemistry on the Antiangiogenic and Antifungal Activities of Itraconazole

    PubMed Central

    2010-01-01

    Itraconazole is used clinically as an antifungal agent and has recently been shown to possess antiangiogenic acitivity. Itraconazole has three chiral centers that give rise to eight stereoisomers. The complete role of stereochemistry in the two activities of itraconazole, however, has not been addressed adequately. For the first time, all eight stereoisomers of itraconazole (1a−h) have been synthesized and evaluated for activity against human endothelial cell proliferation and for antifungal activity against five fungal strains. Distinct antiangiogenic and antifungal activity profiles of the trans stereoisomers, especially 1e and 1f, suggest different molecular mechanisms underlying the antiangiogenic and antifungal activities of itraconazole. PMID:21892383

  18. Measuring the activity of a 51Cr neutrino source based on the gamma-radiation spectrum

    NASA Astrophysics Data System (ADS)

    Gorbachev, V. V.; Gavrin, V. N.; Ibragimova, T. V.; Kalikhov, A. V.; Malyshkin, Yu. M.; Shikhin, A. A.

    2015-12-01

    A technique for the measurement of activities of intense β sources by measuring the continuous gamma-radiation (internal bremsstrahlung) spectra is developed. A method for reconstructing the spectrum recorded by a germanium semiconductor detector is described. A method for the absolute measurement of the internal bremsstrahlung spectrum of 51Cr is presented.

  19. Gamma source for active interrogation

    DOEpatents

    Leung, Ka-Ngo; Lou, Tak Pui; Barletta, William A.

    2009-09-29

    A cylindrical gamma generator includes a coaxial RF-driven plasma ion source and target. A hydrogen plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical gamma generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which has many openings. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired.

  20. Gamma source for active interrogation

    SciTech Connect

    Leung, Ka-Ngo; Lou, Tak Pui; Barletta, William A.

    2012-10-02

    A cylindrical gamma generator includes a coaxial RF-driven plasma ion source and target. A hydrogen plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical gamma generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which has many openings. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired.

  1. Absolute radiation detector

    NASA Astrophysics Data System (ADS)

    Martin, John E.

    1996-11-01

    An absolute radiation detector (a cryogenic radiometer) is being developed to replace the existing UK primary national standard cryogenic radiometer with an improved uncertainty. The cryogenic radiometer will be capable of measuring black body radiation and laser radiation with an uncertainty approaching 10 ppm. From these measurements it will be possible to determine the fundamental constant, the Stefan Boltzmann constant, confirming the radiometer as an absolute detector, and link this determination to the SI unit of luminous intensity, the candela. Thus detector and source based scales/standards will be tied to an invariant physical quantity ensuring their long-term stability.

  2. Absolute Photometry

    NASA Astrophysics Data System (ADS)

    Hartig, George

    1990-12-01

    The absolute sensitivity of the FOS will be determined in SV by observing 2 stars at 3 epochs, first in 3 apertures (1.0", 0.5", and 0.3" circular) and then in 1 aperture (1.0" circular). In cycle 1, one star, BD+28D4211 will be observed in the 1.0" aperture to establish the stability of the sensitivity and flat field characteristics and improve the accuracy obtained in SV. This star will also be observed through the paired apertures since these are not calibrated in SV. The stars will be observed in most detector/grating combinations. The data will be averaged to form the inverse sensitivity functions required by RSDP.

  3. North-south asymmetry of solar activity as a superposition of two realizations - the sign and absolute value

    NASA Astrophysics Data System (ADS)

    Badalyan, O. G.; Obridko, V. N.

    2017-07-01

    Context. Since the occurrence of north-south asymmetry (NSA) of alternating sign may be determined by different mechanisms, the frequency and amplitude characteristics of this phenomenon should be considered separately. Aims: We propose a new approach to the description of the NSA of solar activity. Methods: The asymmetry defined as A = (N-S)/(N + S) (where N and S are, respectively, the indices of activity of the northern and southern hemispheres) is treated as a superposition of two functions: the sign of asymmetry (signature) and its absolute value (modulus). This approach is applied to the analysis of the NSA of sunspot group areas for the period 1874-2013. Results: We show that the sign of asymmetry provides information on the behavior of the asymmetry. In particular, it displays quasi-periodic variation with a period of 12 yr and quasi-biennial oscillations as the asymmetry itself. The statistics of the so-called monochrome intervals (long periods of positive or negative asymmetry) are considered and it is shown that the distribution of these intervals is described by the random distribution law. This means that the dynamo mechanisms governing the cyclic variation of solar activity must involve random processes. At the same time, the asymmetry modulus has completely different statistical properties and is probably associated with processes that determine the amplitude of the cycle. One can reliably isolate an 11-yr cycle in the behavior of the asymmetry absolute value shifted by half a period with respect to the Wolf numbers. It is shown that the asymmetry modulus has a significant prognostic value: the higher the maximum of the asymmetry modulus, the lower the following Wolf number maximum. Conclusions: A fundamental nature of this concept of NSA is discussed in the context of the general methodology of cognizing the world. It is supposed that the proposed description of the NSA will help clarify the nature of this phenomenon.

  4. Absolute stereochemistry of fungal beauveriolide III and ACAT inhibitory activity of four stereoisomers.

    PubMed

    Ohshiro, Taichi; Namatame, Ichiji; Nagai, Kenichiro; Sekiguchi, Takafumi; Doi, Takayuki; Takahashi, Takashi; Akasaka, Kazuaki; Rudel, Lawrence L; Tomoda, Hiroshi; Omura, Satoshi

    2006-09-29

    Fungal beauveriolide III (BeauIII, 1b), a cyclodepsipeptide inhibiting acyl-CoA:cholesterol acyltransferase (ACAT) and showing antiatherogenic activity in mouse models, consists of L-Phe, L-Ala, D-allo-Ile, and 3-hydroxy-4-methyloctanoic acid (HMA) moieties, but the stereochemistry of the HMA part has not until now been fully defined. To determine it, four HMA stereoisomers were synthesized and labeled with (S)-(+)-2-(anthracene-2,3-dicarboximido)-1-propyl trifluoromethane sulfonate (AP-OTf), a chiral fluorescent reagent. The derivatives were separated by HPLC and compared with the natural HMA derivative, which was thereby identified as (3S,4S)HMA in BeauIII. Furthermore, the four beauveriolide III isomers ((3S,4S)BeauIII (23a), (3R,4R)BeauIII (23b), (3R,4S)BeauIII (23c), and (3S,4R)BeauIII (23d)) were synthesized, and it was shown that all the spectral data for 23a were identical with those for natural 1b. Isomers 23a and 23d showed potent inhibitory activity of lipid droplet accumulation in macrophages, while the other two isomers caused weak inhibition. Thus, the 3S configuration of BeauIII is important for this activity. Furthermore, 23a and 23d showed rather specific inhibition against the ACAT1 isozyme.

  5. Advanced Light Source Activity Report 2000

    SciTech Connect

    Greiner, A.; Moxon, L.; Robinson, A.; Tamura, L.

    2001-04-01

    This is an annual report, detailing activities at the Advanced Light Source for the year 2000. It includes highlights of scientific research by users of the facility as well as information about the development of the facility itself.

  6. Transient conduction-radiation analysis of an absolute active cavity radiometer using finite elements

    NASA Technical Reports Server (NTRS)

    Mahan, J. R.; Kowsary, F.; Tira, N.; Gardiner, B. D.

    1987-01-01

    A NASA-developed finite element-based model of a generic active cavity radiometer (ACR) has been developed in order to study the dependence on operating temperature of the closed-loop and open-loop transient response of the instrument. Transient conduction within the sensing element is explored, and the transient temperature distribution resulting from the application of a time-varying radiative boundary condition is calculated. The results verify the prediction that operation of an ACR at cryogenic temperatures results in large gains in frequency response.

  7. The fading of Cassiopeia A, and improved models for the absolute spectrum of primary radio calibration sources

    NASA Astrophysics Data System (ADS)

    Trotter, A. S.; Reichart, D. E.; Egger, R. E.; Stýblová, J.; Paggen, M. L.; Martin, J. R.; Dutton, D. A.; Reichart, J. E.; Kumar, N. D.; Maples, M. P.; Barlow, B. N.; Berger, T. A.; Foster, A. C.; Frank, N. R.; Ghigo, F. D.; Haislip, J. B.; Heatherly, S. A.; Kouprianov, V. V.; LaCluyzé, A. P.; Moffett, D. A.; Moore, J. P.; Stanley, J. L.; White, S.

    2017-08-01

    Based on 5 yr of observations with the 40-foot telescope at Green Bank Observatory (GBO), Reichart & Stephens found that the radio source Cassiopeia A had either faded more slowly between the mid-1970s and late 1990s than Baars et al. had found it to be fading between the late 1940s and mid-1970s, or that it had rebrightened and then resumed fading sometime between the mid-1970s and mid-1990s, in the L band (1.4 GHz). Here, we present 15 additional years of observations of Cas A and Cyg A with the 40-foot in the L band, and three and a half additional years of observations of Cas A, Cyg A, Tau A and Vir A with GBO's recently refurbished 20-m telescope in the L and X (9 GHz) bands. We also present a more sophisticated analysis of the 40-foot data, and a reanalysis of the Baars et al. data, which reveals small, but non-negligible differences. We find that overall, between the late 1950s and late 2010s, Cas A faded at an average rate of 0.670 ± 0.019 per cent yr-1 in the L band, consistent with Reichart & Stephens. However, we also find, at the 6.3σ credible level, that it did not fade at a constant rate. Rather, Cas A faded at a faster rate through at least the late 1960s, rebrightened (or at least faded at a much slower rate), and then resumed fading at a similarly fast rate by, at most, the late 1990s. Given these differences from the original Baars et al. analysis, and given the importance of their fitted spectral and temporal models for flux-density calibration in radio astronomy, we update and improve on these models for all four of these radio sources. In doing so, we additionally find that Tau A is fading at a rate of 0.102^{+0.042}_{-0.043} per cent yr-1 in the L band.

  8. Volatile compounds of Viola odorata absolutes: identification of odorant active markers to distinguish plants originating from France and Egypt.

    PubMed

    Saint-Lary, Laure; Roy, Céline; Paris, Jean-Philippe; Tournayre, Pascal; Berdagué, Jean-Louis; Thomas, Olivier P; Fernandez, Xavier

    2014-06-01

    Absolutes isolated from Viola odorata leaves, valuable materials for the flavor and fragrance industry, were studied. Violets are mainly cultivated in France and Egypt and extracted locally. The absolutes of the two origins showed different olfactory profiles both in top and heart notes, as evidenced by sensory analysis. The aims of this study were i) to characterize the volatile compounds, ii) to determine the odorant-active ones, and iii) to identify some markers of the plant origin. Two complementary analytical methods were used for these purposes, i.e., headspace solid-phase microextraction (HS-SPME) using different fiber coatings followed by GC/MS analysis and gas chromatography - olfactometry/mass spectrometry (GC-O/MS) applied to violet leaf extracts. From a total of 70 identified compounds, 61 have never been reported so far for this species, 17 compounds were characterized by both techniques (with seven among them known from the literature), 23 compounds were solely identified by HS-SPME GC/MS (among them only two being already mentioned as components of violet absolutes in the literature), and, finally, 30 compounds were only identified by GC-O/MS. According to the HS-SPME GC/MS analyses, ethyl hexanoate and (2E,6Z)-nona-2,6-dienol were specific volatile compounds of the sample with French origin, while (E,E)-hepta-2,4-dienal, hexanoic acid, limonene, tridecane, and eugenol were specific of the samples with Egyptian origin. Additional compounds that were not detected by HS-SPME GC/MS analysis were revealed by GC-O analyses, some of them being markers of origin. Pent-1-en-3-ol, 3-methylbut-2-enal, 2-methoxy-3-(1-methylethyl)pyrazine, 4-ethylbenzaldehyde, β-phenethyl formate, and 2-methoxy-3-(2-methylpropyl)pyrazine revealed to be odorant markers of the French sample, whereas cis-rose oxide, trans-rose oxide, and 3,5,5-trimethylcyclohex-2-enone were odorant markers of the Egyptian samples. Copyright © 2014 Verlag Helvetica Chimica Acta AG, Zürich.

  9. Absolute neutrino mass scale

    NASA Astrophysics Data System (ADS)

    Capelli, Silvia; Di Bari, Pasquale

    2013-04-01

    Neutrino oscillation experiments firmly established non-vanishing neutrino masses, a result that can be regarded as a strong motivation to extend the Standard Model. In spite of being the lightest massive particles, neutrinos likely represent an important bridge to new physics at very high energies and offer new opportunities to address some of the current cosmological puzzles, such as the matter-antimatter asymmetry of the Universe and Dark Matter. In this context, the determination of the absolute neutrino mass scale is a key issue within modern High Energy Physics. The talks in this parallel session well describe the current exciting experimental activity aiming to determining the absolute neutrino mass scale and offer an overview of a few models beyond the Standard Model that have been proposed in order to explain the neutrino masses giving a prediction for the absolute neutrino mass scale and solving the cosmological puzzles.

  10. Effects of musical training and absolute pitch ability on event-related activity in response to sine tones.

    PubMed

    Wayman, J W; Frisina, R D; Walton, J P; Hantz, E C; Crummer, G C

    1992-06-01

    The neural correlates of music perception have received relatively little scientific attention. The neural activity of listeners without musical training (N = 11), highly trained musicians (N = 14), and musicians possessing "absolute pitch" (AP) ability (N = 10) have been measured. Major differences were observed in the P3, an endogenous event-related potential (ERP), which is thought to be a neurophysiological manifestation of working memory processing. The P3 was elicited using the classical "oddball" paradigm with a sine-tone series. Subjects' musical backgrounds were evaluated with a survey questionnaire. AP ability was verified with an objective pitch identification test. The P3 amplitude, latency and wave shape were evaluated along with each subjects' performance score and musical background. The AP subjects showed a significantly smaller P3 amplitude than either the musicians or nonmusicians, which were nearly identical. The P3 latency was shortest for the AP subjects, and was longer for the nonmusicians. Performance scores were uniformly high in all three groups. It is concluded that AP subjects do indeed exhibit P3 ERPs, albeit with smaller amplitudes and shorter latencies. The differences in neural activity between the musicians and AP subjects were not due to musical training, as the AP subjects had similar musical backgrounds to the musician group. It is also concluded that persons with the AP ability may have superior auditory sensitivity at cortical levels and/or use unique neuropsychological strategies when processing tones.

  11. Heterotrophic Cultivation of Cyanobacteria: Study of Effect of Exogenous Sources of Organic Carbon, Absolute Amount of Nutrients, and Stirring Speed on Biomass and Lipid Productivity

    PubMed Central

    Meireles dos Santos, Aline; Vieira, Karem Rodrigues; Basso Sartori, Rafaela; Meireles dos Santos, Alberto; Queiroz, Maria Isabel; Queiroz Zepka, Leila; Jacob-Lopes, Eduardo

    2017-01-01

    The production of bioproducts from cyanobacteria with techno-economic feasibility is a challenge to these biotechnological processes. The choice of low-cost raw materials is of great importance for the overall economy of bioprocesses, as they represent a significant percentage in the final cost of the product. The objective of this work was to study the operational parameters of cultivation (exogenous sources of organic carbon and absolute amount of nutrients) to optimize productivity in bioproducts by Aphanothece microscopica Nägeli, for further evaluation of stirring speed. The experiments were performed in a bubble column bioreactor, operating at 30°C, pH of 7.6, C/N ratio of 20, 100 mg/L of inoculum, continuous aeration of 1 volume of air per volume of culture per minute (VVM), and absence of light. The results indicate that absolute amounts of 5,000/250 using cassava starch resulted in improved system performance, reaching biomass productivity of 36.66 mg/L/h in parallel with lipid productivity of 6.65 mg/L/h. Finally, experiments with variation in stirring speed indicate that 200 rpm resulted in better average rate of substrate consumption (44.01 mg/L/h), in parallel to biomass productivity of 39.27 mg/L/h. However, the increase of stirring speed had a negative effect on lipid productivity of the process. The technological route developed indicates potential to production of biomass and bulk oil, as a result of the capacity of cyanobacteria to adapt their metabolism in varying culture conditions, which provides opportunities to modify, control, and thereby maximize the formation of targeted compounds. PMID:28265559

  12. CMOS temperature sensor using a resistively degenerated common-source amplifier biased by an adjustable proportional-to-absolute-temperature voltage

    NASA Astrophysics Data System (ADS)

    Wang, Ruey-Lue; Fu, Chien-Cheng; Yu, Chi; Hao, Yi-Fan; Shi, Jian-Liang; Lin, Chen-Fu; Liao, Hsin-Hao; Tsai, Hann-Huei; Juang, Ying-Zong

    2014-01-01

    A high-linearity CMOS temperature sensor with pulse output is presented. The temperature core is a resistively degenerated common-source amplifier which gate is biased by a proportional-to-absolute-temperature (PTAT) voltage generator. The source resistor is made of polysilicon which resistance has a PTAT characteristic. The current flowing through the resistor exhibits a PTAT characteristic with high linearity of 99.99% at least for a temperature range from 0 to 125 °C. The PTAT voltage generator can be adjusted by a bias voltage Vb and hence the PTAT current can also be adjusted by the Vb. The PTAT current is mirrored to an added current controlled oscillator which output pulse frequencies also exhibit a PTAT characteristic. For the chip using the 0.35 µm process, the plots of measured pulse frequencies against temperature exhibit the sensitivity of 2.30 to 2.24 kHz/°C with linearity of more than 99.99% at the Vb of 1 to 1.2 V.

  13. How calibration and reference spectra affect the accuracy of absolute soft X-ray solar irradiance measured by the SDO/EVE/ESP during high solar activity

    NASA Astrophysics Data System (ADS)

    Didkovsky, Leonid

    2016-10-01

    The Extreme ultraviolet Spectrophotometer (ESP), one of the channels of SDO’s Extreme ultraviolet Variability Experiment (EVE), measures solar irradiance in several EUV and soft x-ray (SXR) bands isolated using thin-film filters and a transmission diffraction grating, and includes a quad-diode detector positioned at the grating zeroth-order to observe in a wavelength band from about 0.1 to 7.0 nm. The quad diode signal also includes some contribution from shorter wavelength in the grating’s first-order and the ratio of zeroth-order to first-order signal depends on both source geometry, and spectral distribution. For example, radiometric calibration of the ESP zeroth-order at the NIST SURF BL-2 with a near-parallel beam provides a different zeroth-to-first-order ratio than modeled for solar observations. The relative influence of “uncalibrated” first-order irradiance during solar observations is a function of the solar spectral irradiance and the locations of large Active Regions or solar flares. We discuss how the “uncalibrated” first-order “solar” component and the use of variable solar reference spectra affect determination of absolute SXR irradiance which currently may be significantly overestimated during high solar activity.

  14. Left-hemisphere activation is associated with enhanced vocal pitch error detection in musicians with absolute pitch.

    PubMed

    Behroozmand, Roozbeh; Ibrahim, Nadine; Korzyukov, Oleg; Robin, Donald A; Larson, Charles R

    2014-02-01

    The ability to process auditory feedback for vocal pitch control is crucial during speaking and singing. Previous studies have suggested that musicians with absolute pitch (AP) develop specialized left-hemisphere mechanisms for pitch processing. The present study adopted an auditory feedback pitch perturbation paradigm combined with ERP recordings to test the hypothesis whether the neural mechanisms of the left-hemisphere enhance vocal pitch error detection and control in AP musicians compared with relative pitch (RP) musicians and non-musicians (NM). Results showed a stronger N1 response to pitch-shifted voice feedback in the right-hemisphere for both AP and RP musicians compared with the NM group. However, the left-hemisphere P2 component activation was greater in AP and RP musicians compared with NMs and also for the AP compared with RP musicians. The NM group was slower in generating compensatory vocal reactions to feedback pitch perturbation compared with musicians, and they failed to re-adjust their vocal pitch after the feedback perturbation was removed. These findings suggest that in the earlier stages of cortical neural processing, the right hemisphere is more active in musicians for detecting pitch changes in voice feedback. In the later stages, the left-hemisphere is more active during the processing of auditory feedback for vocal motor control and seems to involve specialized mechanisms that facilitate pitch processing in the AP compared with RP musicians. These findings indicate that the left hemisphere mechanisms of AP ability are associated with improved auditory feedback pitch processing during vocal pitch control in tasks such as speaking or singing. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Left-hemisphere activation is associated with enhanced vocal pitch error detection in musicians with absolute pitch

    PubMed Central

    Behroozmand, Roozbeh; Ibrahim, Nadine; Korzyukov, Oleg; Robin, Donald A.; Larson, Charles R.

    2014-01-01

    The ability to process auditory feedback for vocal pitch control is crucial during speaking and singing. Previous studies have suggested that musicians with absolute pitch (AP) develop specialized left-hemisphere mechanisms for pitch processing. The present study adopted an auditory feedback pitch perturbation paradigm combined with ERP recordings to test the hypothesis whether the neural mechanisms of the left-hemisphere enhance vocal pitch error detection and control in AP musicians compared with relative pitch (RP) musicians and non-musicians (NM). Results showed a stronger N1 response to pitch-shifted voice feedback in the right-hemisphere for both AP and RP musicians compared with the NM group. However, the left-hemisphere P2 component activation was greater in AP and RP musicians compared with NMs and also for the AP compared with RP musicians. The NM group was slower in generating compensatory vocal reactions to feedback pitch perturbation compared with musicians, and they failed to re-adjust their vocal pitch after the feedback perturbation was removed. These findings suggest that in the earlier stages of cortical neural processing, the right hemisphere is more active in musicians for detecting pitch changes in voice feedback. In the later stages, the left-hemisphere is more active during the processing of auditory feedback for vocal motor control and seems to involve specialized mechanisms that facilitate pitch processing in the AP compared with RP musicians. These findings indicate that the left hemisphere mechanisms of AP ability are associated with improved auditory feedback pitch processing during vocal pitch control in tasks such as speaking or singing. PMID:24355545

  16. EMG and MMG activities of agonist and antagonist muscles in Parkinson's disease patients during absolute submaximal load holding.

    PubMed

    Marusiak, Jaroslaw; Jaskólska, Anna; Kisiel-Sajewicz, Katarzyna; Yue, Guang H; Jaskólski, Artur

    2009-10-01

    The purpose of the study was (1) to assess changes in electromyographical (EMG) and mechanomyographical (MMG) signals of the biceps and triceps brachii muscles during absolute submaximal load holding in Parkinson's disease patients tested during their medication "ON-phase" and in age-matched controls, and (2) to check whether mechanomyography can be useful in evaluation of neuromuscular system activity in Parkinson's disease patients. The data analysis was performed on nine females with Parkinson's disease and six healthy, age-matched females. The EMG and MMG signals were recorded from the short head of the biceps brachii (BB) and the lateral head of the triceps brachii (TB) muscles. It was concluded that compared to the controls, the Parkinson's disease patients exhibited higher amplitude in the biceps brachii muscle and lower median frequency of the MMG signal in the both tested muscles. However, no differences in the EMG amplitude and an increase of the EMG median frequency in the triceps brachii muscle of the Parkinson's disease group were observed. The MMG was not affected by physiological postural tremor and can depict differences between parkinsonians and controls, which may suggest that it is valuable tool for neuromuscular assessment for this condition.

  17. Progress in obtaining an absolute calibration of a total deuterium-tritium neutron yield diagnostic based on copper activation.

    PubMed

    Ruiz, C L; Chandler, G A; Cooper, G W; Fehl, D L; Hahn, K D; Leeper, R J; McWatters, B R; Nelson, A J; Smelser, R M; Snow, C S; Torres, J A

    2012-10-01

    The 350-keV Cockroft-Walton accelerator at Sandia National laboratory's Ion Beam facility is being used to calibrate absolutely a total DT neutron yield diagnostic based on the (63)Cu(n,2n)(62)Cu(β+) reaction. These investigations have led to first-order uncertainties approaching 5% or better. The experiments employ the associated-particle technique. Deuterons at 175 keV impinge a 2.6 μm thick erbium tritide target producing 14.1 MeV neutrons from the T(d,n)(4)He reaction. The alpha particles emitted are measured at two angles relative to the beam direction and used to infer the neutron flux on a copper sample. The induced (62)Cu activity is then measured and related to the neutron flux. This method is known as the F-factor technique. Description of the associated-particle method, copper sample geometries employed, and the present estimates of the uncertainties to the F-factor obtained are given.

  18. Absolute number densities of helium metastable atoms determined by atomic absorption spectroscopy in helium plasma-based discharges used as ambient desorption/ionization sources for mass spectrometry

    NASA Astrophysics Data System (ADS)

    Reininger, Charlotte; Woodfield, Kellie; Keelor, Joel D.; Kaylor, Adam; Fernández, Facundo M.; Farnsworth, Paul B.

    2014-10-01

    The absolute number densities of helium atoms in the 2s 3S1 metastable state were determined in four plasma-based ambient desorption/ionization sources by atomic absorption spectroscopy. The plasmas included a high-frequency dielectric barrier discharge (HF-DBD), a low temperature plasma (LTP), and two atmospheric-pressure glow discharges, one with AC excitation and the other with DC excitation. Peak densities in the luminous plumes downstream from the discharge capillaries of the HF-DBD and the LTP were 1.39 × 1012 cm- 3 and 0.011 × 1012 cm- 3, respectively. Neither glow discharge produced a visible afterglow, and no metastable atoms were detected downstream from the capillary exits. However, densities of 0.58 × 1012 cm- 3 and 0.97 × 1012 cm- 3 were measured in the interelectrode regions of the AC and DC glow discharges, respectively. Time-resolved measurements of metastable atom densities revealed significant random variations in the timing of pulsed absorption signals with respect to the voltage waveforms applied to the discharges.

  19. Cyclic Diarylheptanoids from Corylus avellana Green Leafy Covers: Determination of Their Absolute Configurations and Evaluation of Their Antioxidant and Antimicrobial Activities.

    PubMed

    Cerulli, Antonietta; Lauro, Gianluigi; Masullo, Milena; Cantone, Vincenza; Olas, Beata; Kontek, Bogdan; Nazzaro, Filomena; Bifulco, Giuseppe; Piacente, Sonia

    2017-06-23

    The methanol extract of the leafy covers of Corylus avellana, source of the Italian PGI (protected geographical indication) product "Nocciola di Giffoni", afforded two new cyclic diarylheptanoids, giffonins T and U (2 and 3), along with two known cyclic diarylheptanoids, a quinic acid, flavonoid-, and citric acid derivatives. The structures of giffonins T and U were determined as highly hydroxylated cyclic diarylheptanoids by 1D and 2D NMR experiments. Their relative configurations were assigned by a combined quantum mechanical/NMR approach, comparing the experimental (13)C/(1)H NMR chemical shift data and the related predicted values. The absolute configurations of carpinontriol B (1) and giffonins T and U (2 and 3) were assigned by comparison of their experimental electronic circular dichroism curves with the TDDFT-predicted curves. The ability of the compounds to inhibit the lipid peroxidation induced by H2O2 and H2O2/Fe(2+) was determined by measuring the concentration of thiobarbituric acid reactive substances. Furthermore, the antimicrobial activity of the methanol extract of leafy covers of C. avellana and of the isolated compounds against the Gram-positive strains Bacillus cereus and Staphylococcus aureus and the Gram-negative strains Escherichia coli and Pseudomonas aeruginosa was evaluated. Carpinontriol B (1) and giffonin U (3) at 40 μg/disk caused the formation of zones of inhibition.

  20. Fine structure of the age-chromospheric activity relation in solar-type stars. I. The Ca II infrared triplet: Absolute flux calibration

    NASA Astrophysics Data System (ADS)

    Lorenzo-Oliveira, D.; Porto de Mello, G. F.; Dutra-Ferreira, L.; Ribas, I.

    2016-10-01

    Context. Strong spectral lines are useful indicators of stellar chromospheric activity. They are physically linked to the convection efficiency, differential rotation, and angular momentum evolution and are a potential indicator of age. However, for ages > 2 Gyr, the age-activity relationship remains poorly constrained thus hampering its full application. Aims: The Ca II infrared triplet (IRT lines, λλ 8498, 8542, and 8662) has been poorly studied compared to classical chromospheric indicators. We report in this paper absolute chromospheric fluxes in the three Ca II IRT lines, based on a new calibration tied to up-to-date model atmospheres. Methods: We obtain the Ca II IRT absolute fluxes for 113 FGK stars from high signal-to-noise ratio (S/N) and high-resolution spectra covering an extensive domain of chromospheric activity levels. We perform an absolute continuum flux calibration for the Ca II IRT lines anchored in atmospheric models calculated as an explicit function of effective temperatures (Teff), metallicity ([Fe/H]), and gravities (log g) avoiding the degeneracy usually present in photometric continuum calibrations based solely on color indices. Results: The internal uncertainties achieved for continuum absolute flux calculations are ≈2% of the solar chromospheric flux, one order of magnitude lower than for photometric calibrations. Using Monte Carlo simulations, we gauge the impact of observational errors on the final chromospheric fluxes due to the absolute continuum flux calibration and find that Teffuncertainties are properly mitigated by the photospheric correction leaving [Fe/H] as the dominating factor in the chromospheric flux uncertainty. Conclusions: Across the FGK spectral types, the Ca II IRT lines are sensitive to chromospheric activity. The reduced internal uncertainties reported here enable us to build a new chromospheric absolute flux scale and explore the age-activity relation from the active regime down to very low activity levels and

  1. Measuring the activity of a {sup 51}Cr neutrino source based on the gamma-radiation spectrum

    SciTech Connect

    Gorbachev, V. V. Gavrin, V. N.; Ibragimova, T. V.; Kalikhov, A. V.; Malyshkin, Yu. M.; Shikhin, A. A.

    2015-12-15

    A technique for the measurement of activities of intense β sources by measuring the continuous gamma-radiation (internal bremsstrahlung) spectra is developed. A method for reconstructing the spectrum recorded by a germanium semiconductor detector is described. A method for the absolute measurement of the internal bremsstrahlung spectrum of {sup 51}Cr is presented.

  2. Teaching Absolute Value Meaningfully

    ERIC Educational Resources Information Center

    Wade, Angela

    2012-01-01

    What is the meaning of absolute value? And why do teachers teach students how to solve absolute value equations? Absolute value is a concept introduced in first-year algebra and then reinforced in later courses. Various authors have suggested instructional methods for teaching absolute value to high school students (Wei 2005; Stallings-Roberts…

  3. Absolute kinematics of radio-source components in the complete S5 polar cap sample. IV. Proper motions of the radio cores over a decade and spectral properties

    NASA Astrophysics Data System (ADS)

    Martí-Vidal, I.; Abellán, F. J.; Marcaide, J. M.; Guirado, J. C.; Pérez-Torres, M. A.; Ros, E.

    2016-11-01

    We have carried out a high-precision astrometric analysis of two very-long-baseline-interferometry (VLBI) epochs of observation of the 13 extragalactic radio sources in the complete S5 polar cap sample. The VLBI epochs span a time baseline of ten years and enable us to achieve precisions in the proper motions of the source cores up to a few micro-arcseconds per year. The observations were performed at 14.4 GHz and 43.1 GHz, and enable us to estimate the frequency core-shifts in a subset of sources, for which the spectral-index distributions can be computed. We study the source-position stability by analysing the changes in the relative positions of fiducial source points (the jet cores) over a decade. We find motions of 0.1-0.9 mas among close-by sources between the two epochs, which imply drifts in the jet cores of approximately a few tens of μas per year. These results have implications for the standard Active Galactic Nucleus (AGN) jet model (where the core locations are supposed to be stable in time). For one of our sources, 0615+820, the morphological and spectral properties in year 2010, as well as the relative astrometry between years 2000 and 2010, suggest the possibility of either a strong parsec-scale interaction of the AGN jet with the ISM, a gravitational lens with 1 mas diameter, or a resolved massive binary black hole. Reduced images as FITS files are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/596/A27

  4. Quantyfing the global lightning activity in absolute unints using Schumann resonance spectral decomposition method and the data from the World ELF Radiolocation Array

    NASA Astrophysics Data System (ADS)

    Dyrda, M.; Kulak, A.; Mlynarczyk, J.; Ostrowski, M.

    2015-12-01

    The extremely low frequency (ELF) electromagnetic waves in the Earth-ionosphere cavity are generated mainly by lightning discharges, originating from the tropical thunderstorm centers. The Earth-ionosphere spherical cavity forms a global resonator for the ELF waves. In a spherical damped resonator, like the Earth-ionosphere cavity, the electromagnetic field is the superposition of the standing wave (resonance) field with the traveling waves field, which transfers the energy from lightning flashes to the global resonator. This component is quite strong close to the source and weakens with source-observer separation and is a major reason for an asymmetric shape of the observational Schumann resonance (SR) power spectra. In physics the process, where the resonant field interference with the background is very well known and in such a case the resonant lines are always asymmetric. However, it is possible to separate the resonance field component from the signal using the spectrum decomposition method proposed by Kułak et al. [2006]. Here, we examine the activity of African thunderstorm center using Schumann resonance data collected by the two ELF stations built under the World ELF Radiolocation Array (WERA) project. The first ELF station in located in Poland and it has been recording data continuously since the end of 2004. In May 2015, another ELF station was installed in the Hugo Wildlife Area in Colorado as part of our project WERA. We binned the ELF data in 10-minute files and we derived the SR power spectra. In the next step the decomposition curve, which describes 7 asymmetric SR modes was fitted to the observational data. Using the algorithm, described in Dyrda et al. [2014], we calculated the distances to the tropical thunderstorm center located in Africa with the spatial resolution of 0.1 Mm. This is done independently for each of the ELF stations from WERA array. Then using the information about the distances and about the size of our magnetic antennas beam

  5. Antibiotic activity and absolute configuation of 8S-heptadeca-2(Z),9(Z)-diene-4,6-diyne-1,8-diol from Bupleurum salicifolium.

    PubMed

    Estevez-Braun, A; Estevez-Reyes, R; Moujir, L M; Ravelo, A G; Gonzalez, A G

    1994-08-01

    A polyacetylene has been isolated from Bupleurum salicifolium. Its structure and absolute configuration were determined to be 8S-heptadeca-2(Z),9(Z)-diene-4,6-diyne-1,8-diol [1] by means of 1H- and 13C-nmr spectroscopic studies, including 1H-13C heteronuclear correlation (HMQC) and long-range correlation spectra with inverse detection (HMBC). Its absolute configuration was determined by application of the Horeau method. This compound exhibited significant antibiotic activity against the Gram-positive bacteria Staphylococcus aureus and Bacillus subtilis. Also isolated during this investigation were the known compounds; betulin, herniarin, 6,7,8-trimethoxycoumarin, p-hydroxyphenethyl alcohol, pluviatolide, guamaroline, bursehernin, guayadequiol, kaerophyllin, and matairesinol dimethyl ether.

  6. Estimating Absolute Site Effects

    SciTech Connect

    Malagnini, L; Mayeda, K M; Akinci, A; Bragato, P L

    2004-07-15

    The authors use previously determined direct-wave attenuation functions as well as stable, coda-derived source excitation spectra to isolate the absolute S-wave site effect for the horizontal and vertical components of weak ground motion. They used selected stations in the seismic network of the eastern Alps, and find the following: (1) all ''hard rock'' sites exhibited deamplification phenomena due to absorption at frequencies ranging between 0.5 and 12 Hz (the available bandwidth), on both the horizontal and vertical components; (2) ''hard rock'' site transfer functions showed large variability at high-frequency; (3) vertical-motion site transfer functions show strong frequency-dependence, and (4) H/V spectral ratios do not reproduce the characteristics of the true horizontal site transfer functions; (5) traditional, relative site terms obtained by using reference ''rock sites'' can be misleading in inferring the behaviors of true site transfer functions, since most rock sites have non-flat responses due to shallow heterogeneities resulting from varying degrees of weathering. They also use their stable source spectra to estimate total radiated seismic energy and compare against previous results. they find that the earthquakes in this region exhibit non-constant dynamic stress drop scaling which gives further support for a fundamental difference in rupture dynamics between small and large earthquakes. To correct the vertical and horizontal S-wave spectra for attenuation, they used detailed regional attenuation functions derived by Malagnini et al. (2002) who determined frequency-dependent geometrical spreading and Q for the region. These corrections account for the gross path effects (i.e., all distance-dependent effects), although the source and site effects are still present in the distance-corrected spectra. The main goal of this study is to isolate the absolute site effect (as a function of frequency) by removing the source spectrum (moment-rate spectrum) from

  7. System for absolute measurements by interferometric sensors

    NASA Astrophysics Data System (ADS)

    Norton, Douglas A.

    1993-03-01

    The most common problem of interferometric sensors is their inability to measure absolute path imbalance. Presented in this paper is a signal processing system that gives absolute, unambiguous reading of optical path difference for almost any style of interferometric sensor. Key components are a wide band (incoherent) optical source, a polychromator, and FFT electronics. Advantages include no moving parts in the signal processor, no active components at the sensor location, and the use of standard single mode fiber for sensor illumination and signal transmission. Actual absolute path imbalance of the interferometer is determined without using fringe counting or other inferential techniques. The polychromator extracts the interference information that occurs at each discrete wavelength within the spectral band of the optical source. The signal processing consists of analog and digital filtering, Fast Fourier analysis, and a peak detection and interpolation algorithm. This system was originally designed for use in a remote pressure sensing application that employed a totally passive fiber optic interferometer. A performance qualification was made using a Fabry-Perot interferometer and a commercially available laser interferometer to measure the reference displacement.

  8. WFSD fault monitoring using active seismic source

    NASA Astrophysics Data System (ADS)

    Yang, W.; Ge, H.; Wang, B.; Yuan, S.; Song, L.

    2010-12-01

    The Wenchuan Fault Scientific Drilling(WFSD)is a rapid response drilling project to the great Wenchuan earthquake. It focuses on the fault structure, earthquake physical mechanism, fluid and in-situ stress, energy budget and so on. Temporal variation of stress and physical property in the fault zone is important information for understanding earthquake physics, especially when the fault is still under the post-seismic recovery or stress modification. Seismic velocity is a good indicator of the medium mechanics, stress state within the fault zone. After the great Wenchuan Ms 8.0 earthquake, May 12, 2008, we built up a fault dynamic monitoring system using active seismic source cross the WFSD fault. It consists of a 10 ton accurately controlled eccentric mass source and eight receivers to continuously monitor the seismic velocity cross the fault zone. Combining the aftershock data, we try to monitor the fault recovery and some aftershock physical process. The observatory is located at the middle of the Longmenshan range-front fault, Mianzhu, Sichuan Province. The No.3 hole of WFSD is on the survey line near the No.4 receiver. The source and receiver site were carefully treated. All instruments were well installed to ensure the system's repeatability. Seismic velocity across the fault zone was monitored with continuous observation. The recording system consists of Guralp-40T short period seismometer and RefTek-130B recorder which was continuously GPS timed up to 20us. The active source ran since June 20, 2009. It was operated routinely at night and working continuously from 21:00 to 02:00 of the next day. So far, we have gotten almost one year recording. The seismic velocity variation may be caused by changes of the fault zone medium mechanical property, fault stress, fluid, and earth tide, barometric pressure and rainfall. Deconvolution, stacking and cross-correlation analysis were used for the velocity analysis. Results show that the relationship between seismic

  9. Synthesis and anti-HIV activity of lupane and olean-18-ene derivatives. Absolute configuration of 19,20-epoxylupanes by VCD.

    PubMed

    Gutiérrez-Nicolás, Fátima; Gordillo-Román, Bárbara; Oberti, Juan C; Estévez-Braun, Ana; Ravelo, Angel G; Joseph-Nathan, Pedro

    2012-04-27

    Lupane triterpenoids 2 and 5-12 and oleanene derivatives 13 and 14 were prepared from lupeol (1), betulin (3), and germanicol (4). They were tested for anti-HIV activity, and some structure-activity relationships were outlined. The 20-(S) absolute configuration of epoxylupenone (8) was assessed by comparison of the observed and DFT-calculated vibrational circular dichroism spectra. The CompareVOA algorithm was employed to support the C-20 configuration assignment. The 20,29 double bond in lupenone (2) and 3-epilupeol (15) was stereoselectively epoxidized to produce 20-(S)-8 and 20-(S)-16, respectively, an assignment in agreement with their X-ray diffraction structures.

  10. Absolutely classical spin states

    NASA Astrophysics Data System (ADS)

    Bohnet-Waldraff, F.; Giraud, O.; Braun, D.

    2017-01-01

    We introduce the concept of "absolutely classical" spin states, in analogy to absolutely separable states of bipartite quantum systems. Absolutely classical states are states that remain classical (i.e., a convex sum of projectors on coherent states of a spin j ) under any unitary transformation applied to them. We investigate the maximal size of the ball of absolutely classical states centered on the maximally mixed state and derive a lower bound for its radius as a function of the total spin quantum number. We also obtain a numerical estimate of this maximal radius and compare it to the case of absolutely separable states.

  11. Advanced Light Source Activity Report 2002

    SciTech Connect

    Duque, Theresa; Greiner, Annette; Moxon, Elizabeth; Robinson, Arthur; Tamura, Lori

    2003-06-12

    This annual report of the Advanced Light Source details science highlights and facility improvements during the year. It also offers information on events sponsored by the facility, technical specifications, and staff and publication information.

  12. Source apportionment of ambient non-methane hydrocarbons in Hong Kong: application of a principal component analysis/absolute principal component scores (PCA/APCS) receptor model.

    PubMed

    Guo, H; Wang, T; Louie, P K K

    2004-06-01

    Receptor-oriented source apportionment models are often used to identify sources of ambient air pollutants and to estimate source contributions to air pollutant concentrations. In this study, a PCA/APCS model was applied to the data on non-methane hydrocarbons (NMHCs) measured from January to December 2001 at two sampling sites: Tsuen Wan (TW) and Central & Western (CW) Toxic Air Pollutants Monitoring Stations in Hong Kong. This multivariate method enables the identification of major air pollution sources along with the quantitative apportionment of each source to pollutant species. The PCA analysis identified four major pollution sources at TW site and five major sources at CW site. The extracted pollution sources included vehicular internal engine combustion with unburned fuel emissions, use of solvent particularly paints, liquefied petroleum gas (LPG) or natural gas leakage, and industrial, commercial and domestic sources such as solvents, decoration, fuel combustion, chemical factories and power plants. The results of APCS receptor model indicated that 39% and 48% of the total NMHCs mass concentrations measured at CW and TW were originated from vehicle emissions, respectively. 32% and 36.4% of the total NMHCs were emitted from the use of solvent and 11% and 19.4% were apportioned to the LPG or natural gas leakage, respectively. 5.2% and 9% of the total NMHCs mass concentrations were attributed to other industrial, commercial and domestic sources, respectively. It was also found that vehicle emissions and LPG or natural gas leakage were the main sources of C(3)-C(5) alkanes and C(3)-C(5) alkenes while aromatics were predominantly released from paints. Comparison of source contributions to ambient NMHCs at the two sites indicated that the contribution of LPG or natural gas at CW site was almost twice that at TW site. High correlation coefficients (R(2) > 0.8) between the measured and predicted values suggested that the PCA/APCS model was applicable for estimation

  13. Calorimetric method for determination of 51Cr neutrino source activity

    NASA Astrophysics Data System (ADS)

    Veretenkin, E. P.; Gavrin, V. N.; Danshin, S. N.; Ibragimova, T. V.; Kozlova, Yu. P.; Mirmov, I. N.

    2015-12-01

    Experimental study of nonstandard neutrino properties using high-intensity artificial neutrino sources requires the activity of the sources to be determined with high accuracy. In the BEST project, a calorimetric system for measurement of the activity of high-intensity (a few MCi) neutrino sources based on 51Cr with an accuracy of 0.5-1% is created. In the paper, the main factors affecting the accuracy of determining the neutrino source activity are discussed. The calorimetric system design and the calibration results using a thermal simulator of the source are presented.

  14. National Synchrotron Light Source 2010 Activity Report

    SciTech Connect

    Rowe, M.; Snyder, K. J.

    2010-12-29

    This is a very exciting period for photon sciences at Brookhaven National Laboratory. It is also a time of unprecedented growth for the Photon Sciences Directorate, which operates the National Synchrotron Light Source (NSLS) and is constructing NSLS-II, both funded by the Department of Energy's Office of Science. Reflecting the quick pace of our activities, we chose the theme 'Discovery at Light Speed' for the directorate's 2010 annual report, a fiscal year bookended by October 2009 and September 2010. The year began with the news that NSLS users Venki Ramakrishnan of Cambridge University (also a former employee in Brookhaven's biology department) and Thomas A. Steitz of Yale University were sharing the 2009 Nobel Prize in Chemistry with Ada E. Yonath of the Weizmann Institute of Science. Every research project has the potential for accolades. In 2010, NSLS users and staff published close to 900 papers, with about 170 appearing in premiere journals. Those are impressive stats for a facility nearly three decades old, testament to the highly dedicated team keeping NSLS at peak performance and the high quality of its user community. Our NSLS users come from a worldwide community of scientists using photons, or light, to carry out research in energy and environmental sciences, physics, materials science, chemistry, biology and medicine. All are looking forward to the new capabilities enabled by NSLS-II, which will offer unprecedented resolution at the nanoscale. The new facility will produce x-rays more than 10,000 times brighter than the current NSLS and host a suite of sophisticated instruments for cutting-edge science. Some of the scientific discoveries we anticipate at NSLS-II will lead to major advances in alternative energy technologies, such as hydrogen and solar. These discoveries could pave the way to: (1) catalysts that split water with sunlight for hydrogen production; (2) materials that can reversibly store large quantities of electricity or hydrogen; (3

  15. Recent negative ion source activity at JYFL

    NASA Astrophysics Data System (ADS)

    Kalvas, T.; Tarvainen, O.; Komppula, J.; Laitinen, M.; Sajavaara, T.; Koivisto, H.; Jokinen, A.; Dehnel, M. P.

    2013-02-01

    A filament-powered multicusp ion source for production of H- has been developed for the Jyväskylä Pelletron accelerator for use in ion beam lithography and particle induced X-ray emission applications. The source can be considered conventional with the exception of the filter field being created with an electric magnet for continuous adjustability. A permanent magnet dipoleantidipole electron dump is integrated in the puller electrode. The source provides 50 μA H- beam at 10 keV energy with 0.019 mm mrad 95 % normalized rms emittance through a 2 mm aperture. Lower emittance is achievable by changing the plasma electrode insert to a smaller aperture one if application requires. A new commercial MCC30/15 cyclotron has been installed at the Jyväskylä accelerator laboratory providing 30MeV H+ and 15Mev D+ for use in nuclear physics experiments and applications. The ion source delivered with the cyclotron is a a filament-powered multicusp source capable of about 130 h continuous operation at 1 mA H- output between filament changes. The ion source is located in the cyclotron vault and therefore a significant waiting time for the vault cooldown is required before filament change is possible. This kind of operation is not acceptable as 350 h and longer experiments are expected. Therefore a project for developing a CW 13.56 MHz RF ion source has been initiated. A planar RF antenna replacing the filament back plate of the existing TRIUMF-type ion source has been used in the first tests with 240 μA of H- and 21 mA of electrons measured at 1.5 kW of RF power. Tests with higher RF power levels were prevented by electron beam induced sparking. A new plasma chamber has been built and a new extraction is being designed for the RF ion source. The extraction code IBSimu has recently gone through a major update on how smooth electrode surfaces are implemented in the Poisson solvers. This has made it possible to implement a fast multigrid solver with low memory consumption. Also

  16. NATIONAL SYNCHROTRON LIGHT SOURCE ACTIVITY REPORT 1998.

    SciTech Connect

    ROTHMAN,E.

    1999-05-01

    In FY 1998, following the 50th Anniversary Year of Brookhaven National Laboratory, Brookhaven Science Associates became the new Managers of BNL. The new start is an appropriate time to take stock of past achievements and to renew or confirm future goals. During the 1998 NSLS Annual Users Meeting (described in Part 3 of this Activity Report), the DOE Laboratory Operations Board, Chaired by the Under Secretary for Energy, Ernest Moniz met at BNL. By chance all the NSLS Chairmen except Martin Blume (acting NSLS Chair 84-85) were present as recorded in the picture. Under their leadership the NSLS has improved dramatically: (1) The VUV Ring current has increased from 100 mA in October 1982 to nearly 1 A today. For the following few years 10 Ahrs of current were delivered most weeks - NSLS now exceeds that every day. (2) When the first experiments were performed on the X-ray ring during FY1985 the electron energy was 2 GeV and the current up to 100 mA - the X-Ray Ring now runs routinely at 2.5 GeV and at 2.8 GeV with up to 350 mA of current, with a very much longer beam half-life and improved reliability. (3) Starting in FY 1984 the proposal for the Phase II upgrade, mainly for a building extension and a suite of insertion devices and their associated beamlines, was pursued - the promises were delivered in full so that for some years now the NSLS has been running with two undulators in the VUV Ring and three wigglers and an undulator in the X-Ray Ring. In addition two novel insertion devices have been commissioned in the X13 straight. (4) At the start of FY 1998 the NSLS welcomed its 7000th user - attracted by the opportunity for pursuing research with high quality beams, guaranteed not to be interrupted by 'delivery failures', and welcomed by an efficient and caring user office and first class teams of PRT and NSLS staff. R & D have lead to the possibility of running the X-Ray Ring at the higher energy of 2.8 GeV. Figure 1 shows the first user beam, which was provided

  17. NATIONAL SYNCHROTRON LIGHT SOURCE ACTIVITY REPORT 2004

    SciTech Connect

    MILLER,L.

    2005-05-01

    for the environmental science community, is also very important, as it will help to satisfy the large over subscription rate for this technique at the NSLS. Two other important upgrades that were initiated this past year are the replacement of the X25 wiggler with an undulator and the construction of the X9 undulator beamline for small-angle scattering, with an emphasis on nanoscience research. Another key activity that will benefit all users was the restoration of the x-ray ring lattice symmetry, which reduced the horizontal emittance and made the operational lattice more robust. Similarly, all users will benefit from the introduction of the PASS (Proposal Allocation Safety Scheduling) system this past year, which has greatly improved the process of proposal submission, review, allocation, and scheduling. This coming year we will work to add Rapid Access to the capabilities of PASS. Overall, the success of these and the many other projects that space does not permit listing is a testament to the dedication, hard work, and skill of the NSLS staff. Safety has always been an important issue at a large, complex scientific facility like the NSLS and in 2004 it received renewed attention. Safety is our highest priority and we spent a great deal of time reviewing and refining our safety practices and procedures. A new 'Safety Highlights' web page was created for safety news, and a large number of safety meetings and discussions were held. These reviews and meetings generated many ideas on how the NSLS might improve its safety practices, and we are committed to putting these in place and improving our already very good safety program. We had no lost-time accidents in 2004, which is a notable accomplishment. Our goal is to be best in class and I'm confident that by working together we can achieve that status. Several activities took place this past year to advance our proposal to replace the NSLS with a new National Synchrotron Light Source-II facility. These included a major

  18. Absolute measurement of (198)Au activity in gold foil using plastic scintillators and a well-type NaI(Tl) detector.

    PubMed

    Kim, Yun Ho; Kim, Jungho; Lee, Jong-Man; Park, Hyeonseo

    2016-03-01

    A beta-gamma coincidence system has been developed for measuring (198)Au activity in gold foils. The system was validated by Monte Carlo simulations and by measuring the activity of a (60)Co point-source. To study effects such as self-shielding of beta particles in gold foils, (198)Au activity measurements and simulations were performed for various scintillators and foil sizes. The measured (198)Au activities were ~1% above the reference activity, which might be due to self-shielding of beta particles. The measured and simulated (198)Au activities agreed, suggesting feasibility of precise activity measurement.

  19. Deletion mutants of Harvey ras p21 protein reveal the absolute requirement of at least two distant regions for GTP-binding and transforming activities.

    PubMed Central

    Lacal, J C; Anderson, P S; Aaronson, S A

    1986-01-01

    Deletions of small sequences from the viral Harvey ras gene have been generated, and resulting ras p21 mutants have been expressed in Escherichia coli. Purification of each deleted protein allowed the in vitro characterization of GTP-binding, GTPase and autokinase activity of the proteins. Microinjection of the highly purified proteins into quiescent NIH/3T3 cells, as well as transfection experiments utilizing a long terminal repeat (LTR)-containing vector, were utilized to analyze the biological activity of the deleted proteins. Two small regions located at 6-23 and 152-165 residues are shown to be absolutely required for in vitro and in vivo activities of the ras product. By contrast, the variable region comprising amino acids 165-184 was shown not to be necessary for either in vitro or in vivo activities. Thus, we demonstrate that: (i) amino acid sequences at positions 5-23 and 152-165 of ras p21 protein are probably directly involved in the GTP-binding activity; (ii) GTP-binding is required for the transforming activity of ras p21 and by extension for the normal function of the proto-oncogene product; and (iii) the variable region at the C-terminal end of the ras p21 molecule from amino acids 165 to 184 is not required for transformation. Images Fig.2. Fig.4. PMID:3011420

  20. Ambient air quality measurements from a continuously moving mobile platform: Estimation of area-wide, fuel-based, mobile source emission factors using absolute principal component scores

    NASA Astrophysics Data System (ADS)

    Larson, Timothy; Gould, Timothy; Riley, Erin A.; Austin, Elena; Fintzi, Jonathan; Sheppard, Lianne; Yost, Michael; Simpson, Christopher

    2017-03-01

    We have applied the absolute principal component scores (APCS) receptor model to on-road, background-adjusted measurements of NOx, CO, CO2, black carbon (BC), and particle number (PN) obtained from a continuously moving platform deployed over nine afternoon sampling periods in Seattle, WA. Two Varimax-rotated principal component features described 75% of the overall variance of the observations. A heavy-duty vehicle feature was correlated with black carbon and particle number, whereas a light-duty feature was correlated with CO and CO2. NOx had moderate correlation with both features. The bootstrapped APCS model predictions were used to estimate area-wide, average fuel-based emission factors and their respective 95% confidence limits. The average emission factors for NOx, CO, BC and PN (14.8, 18.9, 0.40 g/kg, and 4.3 × 1015 particles/kg for heavy duty vehicles, and 3.2, 22.4, 0.016 g/kg, and 0.19 × 1015 particles/kg for light-duty vehicles, respectively) are consistent with previous estimates based on remote sensing, vehicle chase studies, and recent dynamometer tests. Information on the spatial distribution of the concentrations contributed by these two vehicle categories relative to background during the sampling period was also obtained.

  1. Strategy for the absolute neutron emission measurement on ITER.

    PubMed

    Sasao, M; Bertalot, L; Ishikawa, M; Popovichev, S

    2010-10-01

    Accuracy of 10% is demanded to the absolute fusion measurement on ITER. To achieve this accuracy, a functional combination of several types of neutron measurement subsystem, cross calibration among them, and in situ calibration are needed. Neutron transport calculation shows the suitable calibration source is a DT/DD neutron generator of source strength higher than 10(10) n/s (neutron/second) for DT and 10(8) n/s for DD. It will take eight weeks at the minimum with this source to calibrate flux monitors, profile monitors, and the activation system.

  2. Background and Source Term Identification in Active Neutron Interrogation Methods

    DTIC Science & Technology

    2011-03-24

    theory section, ring detector tallies (f5 – MCNP) provided both neutron and photon fluences [particles/cm2] as functions of their energies. Figure 19...BACKGROUND AND SOURCE TERM IDENTIFICATION IN ACTIVE NEUTRON INTERROGATION METHODS THESIS...M01 BACKGROUND AND SOURCE TERM IDENTIFICATION IN ACTIVE NEUTRON INTERROGATION METHODS THESIS Presented to the Faculty Department of

  3. Active Control of Aerodynamic Noise Sources

    NASA Technical Reports Server (NTRS)

    Reynolds, Gregory A.

    2001-01-01

    Aerodynamic noise sources become important when propulsion noise is relatively low, as during aircraft landing. Under these conditions, aerodynamic noise from high-lift systems can be significant. The research program and accomplishments described here are directed toward reduction of this aerodynamic noise. Progress toward this objective include correction of flow quality in the Low Turbulence Water Channel flow facility, development of a test model and traversing mechanism, and improvement of the data acquisition and flow visualization capabilities in the Aero. & Fluid Dynamics Laboratory. These developments are described in this report.

  4. Sources of optically active aerosol particles over the Amazon forest

    NASA Astrophysics Data System (ADS)

    Guyon, Pascal; Graham, Bim; Roberts, Gregory C.; Mayol-Bracero, Olga L.; Maenhaut, Willy; Artaxo, Paulo; Andreae, Meinrat O.

    Size-fractionated ambient aerosol samples were collected at a pasture site and a primary rainforest site in the Brazilian Amazon Basin during two field campaigns (April-May and September-October 1999), as part of the European contribution to the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA-EUSTACH). The samples were analyzed for up to 19 trace elements by particle-induced X-ray emission analysis (PIXE), for equivalent black carbon (BC e) by a light reflectance technique and for mass concentration by gravimetric analysis. Additionally, we made continuous measurements of absorption and light scattering by aerosol particles. The vertical chemical composition gradients at the forest site have been discussed in a companion article (Journal of Geophysical Research-Atmospheres 108 (D18), 4591 (doi:4510.1029/2003JD003465)). In this article, we present the results of a source identification and quantitative apportionment study of the wet and dry season aerosols, including an apportionment of the measured scattering and absorption properties of the total aerosol in terms of the identified aerosol sources. Source apportionments (obtained from absolute principal component analysis) revealed that the wet and dry season aerosols contained the same three main components, but in different (absolute and relative) amounts: the wet season aerosol consisted mainly of a natural biogenic component, whereas pyrogenic aerosols dominated the dry season aerosol mass. The third component identified was soil dust, which was often internally mixed with the biomass-burning aerosol. All three components contributed significantly to light extinction during both seasons. At the pasture site, up to 47% of the light absorption was attributed to biogenic particles during the wet season, and up to 35% at the tower site during the wet-to-dry transition period. The results from the present study suggest that, in addition to pyrogenic particles, biogenic and soil dust aerosols must be

  5. Advanced Light Source: Activity report 1993

    SciTech Connect

    Not Available

    1994-11-01

    The Advanced Light Source (ALS) produces the world`s brightest light in the ultraviolet and soft x-ray regions of the spectrum. The first low-energy third-generation synchrotron source in the world, the ALS provides unprecedented opportunities for research in science and technology not possible anywhere else. This year marked the beginning of operations and the start of the user research program at the ALS, which has already produced numerous high quality results. A national user facility located at Lawrence Berkeley Laboratory of the University of California, the ALS is available to researchers from academia, industry, and government laboratories. This report contains the following: (1) director`s message; (2) operations overview; (3) user program; (4) users` executive committee; (5) industrial outreach; (6) accelerator operations; (7) beamline control system; (8) insertion devices; (9) experimental systems; (10) beamline engineering; (11) first results from user beamlines; (12) beamlines for 1994--1995; (13) special events; (14) publications; (15) advisory panels; and (16) ALS staff.

  6. H - ion source activities at DESY

    NASA Astrophysics Data System (ADS)

    Peters, J.

    1994-04-01

    The H- source for HERA is based on the design of that at FNAL. It was modified according to the Deutsches Elektronen-Synchrotron requirements. There is only one H- source connected to the H- LINAC. It must run for long uninterrupted periods with a low duty factor and a high reliability. The measured cesium distribution showed that it is necessary to keep the cold box as a barrier. The operation of the cold box was improved with a new type of high voltage insulator and a special protection against condensation at the feedthrough for high voltage and -30 °C freon. The bending magnet of the cold box will be further improved by using a permanent magnet instead of the electromagnet. A unit was designed that includes all the essential elements which are under vacuum. It can be replaced in minutes and contains a newly designed H2 piezovalve and a remodeled magnetron. The cathode of the magnetron can be heated. It is now possible to run at a low repetition rate of 1/4 Hz and thus reduce Cs and H2 consumption.

  7. The central power source in active galaxies

    NASA Technical Reports Server (NTRS)

    Ptak, Roger; Stoner, Ronald

    1987-01-01

    Potential sources for the central power in AGN are examined. The continuum, emission line profiles, and time variability and broad emission line region for AGN are analyzed. The supermassive black hole hypothesis, the supermassive magnetized core model of Kundt (1978), and the model of Stoner and Ptak (1984) in which the supermassive stars maintain a kind of long-term quasi-stability, but accretion is balanced by mass loss and spherical bursts rather than in jets are considered. It is argued that the hypothesis that the supermassive blackholes are the central engines for AGN is based on theoretical principles; however, AGN emission line profiles and variability suggest a spherical geometry for the observed components of these engines. Also the supermassive black hole models do not account for all the AGN observations.

  8. The Enlightenment Revisited: Sources & Interpretations. Learning Activities.

    ERIC Educational Resources Information Center

    Donato, Clorinda; And Others

    This resource book provides 26 learning activities with background materials for teaching about the Enlightenment. Topics include: (1) "What Was the Enlightenment?"; (2) "An Introduction to the Philosophes"; (3) "Was the Enlightenment a Revolt Against Rationalism?"; (4) "Were the Philosophes Democrats? A…

  9. New and highly active microbial phosphotriesterase sources.

    PubMed

    Santillan, Julia Y; Dettorre, Lucas A; Lewkowicz, Elizabeth S; Iribarren, Adolfo M

    2016-12-01

    Many toxic insecticides used worldwide as well as some chemical warfare agents are phosphotriester derivatives. Therefore, detoxification of organophosphorus compounds has become the subject of many studies and in particular bioremediation, based on the phosphotriesterase catalysed hydrolysis of these compounds, has shown to be an effective and ecological methodology. In order to identify new bacterial phosphotriesterases, a simple and sensitive fluorimetric screening method on solid media was employed that allowed the selection of six strains with phosphotriesterase activity. Since pH and temperature are important parameters for bioremediation of contaminated soils and waters, the influence of these variables on the rate of the enzymatic hydrolysis was assessed. This study afforded notable results, being the most remarkable one the increased activity exhibited by Nocardia asteroides and Streptomyces setonii strains at 50°C, 7 and 30 times higher than at 30°C, respectively. Compared with the results obtained with Brevundimonas diminuta, whose activity is usually considered as reference, an increase of 26 and 75 times is observed, respectively.

  10. Absolute and relative blindsight.

    PubMed

    Balsdon, Tarryn; Azzopardi, Paul

    2015-03-01

    The concept of relative blindsight, referring to a difference in conscious awareness between conditions otherwise matched for performance, was introduced by Lau and Passingham (2006) as a way of identifying the neural correlates of consciousness (NCC) in fMRI experiments. By analogy, absolute blindsight refers to a difference between performance and awareness regardless of whether it is possible to match performance across conditions. Here, we address the question of whether relative and absolute blindsight in normal observers can be accounted for by response bias. In our replication of Lau and Passingham's experiment, the relative blindsight effect was abolished when performance was assessed by means of a bias-free 2AFC task or when the criterion for awareness was varied. Furthermore, there was no evidence of either relative or absolute blindsight when both performance and awareness were assessed with bias-free measures derived from confidence ratings using signal detection theory. This suggests that both relative and absolute blindsight in normal observers amount to no more than variations in response bias in the assessment of performance and awareness. Consideration of the properties of psychometric functions reveals a number of ways in which relative and absolute blindsight could arise trivially and elucidates a basis for the distinction between Type 1 and Type 2 blindsight.

  11. Absolute stereochemistry and dopaminergic activity of enantiomers of 2,3,4,5-tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine.

    PubMed

    Kaiser, C; Dandridge, P A; Garvey, E; Hahn, R A; Sarau, H M; Setler, P E; Bass, L S; Clardy, J

    1982-06-01

    Resolution of the unique dopamine receptor agonist 2,3,4,5-tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine (1) was achieved by a stereospecific multistep conversion of the readily separated enantiomers of its O,O,N-trimethylated precursor 2. The absolute stereochemistry of the antipodes of 2-MeI was determined by single-crystal X-ray diffractometric analysis, thus permitting assignment of the configuration of stereospecifically related 1, as well as that of the synthetic intermediates. High-performance liquid chromatography of diastereoisomeric derivatives was utilized to determine the enantiomeric excess of the R (greater than 97%) and S (greater than 89%) isomers of 1. Examination of the isomers in several in vitro and in vivo tests for both central and peripheral dopaminergic activity revealed that activity resided almost exclusively in the R isomer. The results suggest that the properly oriented 1-phenyl substituent of 1 is important for dopamine-like activity; it may contribute to receptor binding by interaction with a chirally defined accessory site. Configurational and conformational requirements for receptor binding of 1 are considered in relationship to previously described dopaminergic agents. These studies, in accord with previous suggestions, indicate that (R)-1 interacts with dopamine receptors in a conformation in which the catecholic hydroxyls and basic nitrogen are at least nearly maximally separated.

  12. [Obsessive-compulsive symptoms, tics, stereotypic movements or need for absolute consistency? The occurrence of repetitive activities in patients with pervasive developmental disorders--case studies].

    PubMed

    Bryńska, Anita; Lipińska, Elzbieta; Matelska, Monika

    2011-01-01

    Repetitive and stereotyped behaviours in the form of stereotyped interests or specific routine activities are one ofthe diagnostic criteria in pervasive developmental disorders. The occurrence of repetitive behaviours in patients with pervasive developmental disorders is a starting point for questions about the type and classification criteria of such behaviours. The aim of the article is to present case studies of patients with pervasive developmental disorders and co-morbid symptoms in the form of routine activities, tics, obsessive-compulsive symptoms or stereotyped behaviours. The first case study describes a patient with Asperger's syndrome and obsessive compulsive symptoms. The diagnostic problems regarding complex motor tics are discussed in the second case study which describes a patient with Asperger's syndrome and Gilles de la Tourette syndrome. The third and fourth case study describes mono-zygotic twins with so called High Functioning Autism whose repetitive activities point to either obsessive compulsive symptoms, stereotypic movements, need for absolute consistency or echopraxia. The possible comorbidity of pervasive developmental disorders and symptoms in the form of repetitive behaviours, possible interactions as well as diagnostic challenges is discussed in the article.

  13. Absolute bioavailability of cis-mirincamycin and trans-mirincamycin in healthy rhesus monkeys and ex vivo antimalarial activity against Plasmodium falciparum.

    PubMed

    Khemawoot, Phisit; Saunders, David; Rasameesoraj, Maneerat; Melendez, Victor; Imerbsin, Rawiwan; Ohrt, Colin; Fracisco, Susan; Teja-Isavadharm, Paktiya

    2011-12-01

    The pharmacokinetics, oral bioavailability, and ex vivo antimalarial activity of mirincamycin isomers in a healthy rhesus monkey model were assessed to support lead optimization of novel nonhemolytic drugs for radical cure and causal prophylaxis of malaria. Fourteen male rhesus monkeys were randomized to four groups, which included cis and trans isomers by the oral and intravenous routes, with vehicle-only controls for each dosing route. Concentration-time data were collected for 7 days and were analyzed by noncompartmental analysis. cis-Mirincamycin had an absolute oral bioavailability of 13.6%, which was slightly higher than that of trans-mirincamycin (11.7%), but this difference was not statistically significant. There was a statistically significant difference between the area under the concentration-time curve from zero to 48 h (AUC(0-48)) of cis-mirincamycin and that of trans-mirincamycin after oral dosing. When cultured in vitro with the W2 clone of Plasmodium falciparum, the 50% inhibitory concentrations for cis-mirincamycin, trans-mirincamycin, and dihydroartemisinin were 11,300, 12,300, and 2.30 nM, respectively. However, when dosed primate plasma was cultured ex vivo against the W2 clone, both isomers had much greater relative potencies than their in vitro activities relative to results for dihydroartemisinin, an increase of approximately 100-fold for the cis isomer and 150-fold for the trans isomer. Further, oral ex vivo activity was significantly higher than intravenous activity for both isomers, particularly during the first 90 min following dosing, suggesting the first-pass formation of one or more metabolites with blood-stage antimalarial activity. Identification of the metabolic pathways and metabolites may help to further delineate the properties of this class of drugs with previously demonstrated liver-stage antimalarial activity.

  14. Advanced light source. Activity report 1995

    SciTech Connect

    1996-07-01

    The ALS Activity Report is designed to share the breadth, variety, and interest of the scientific program and ongoing R&D efforts in a form that is accessible to a broad audience. Recent research results are presented in six sections, each representing an important theme in ALS science. These results are designed to demonstrate the capabilities of the ALS, rather than to give a comprehensive review of 1995 experiments. Although the scientific program and facilities report are separate sections, in practice the achievements and accomplishments of users and ALS staff are interdependent. This user-staff collaboration is essential to help us direct our efforts toward meeting the needs of the user community, and to ensure the continued success of the ALS as a premier facility.

  15. National Synchrotron Light Source 2008 Activity Report

    SciTech Connect

    Nasta,K.

    2009-05-01

    Funded by the U.S. Department of Energy's Office of Basic Energy Sciences, the National Synchrotron Light Source (NSLS) is a national user facility that operates two electron storage rings: X-Ray (2.8 GeV, 300 mA) and Vacuum Ultraviolet (VUV) (800 mev, 1.0A). These two rings provide intense light spanning the electromagnetic spectrum -- from very long infrared rays to ultraviolet light and super-short x-rays -- to analyze very small or highly dilute samples. The properties of this light, and the specially designed experimental stations, called beamlines, allow scientists in many diverse disciplines of research to perform experiments not possible at their own laboratories. Each year, about 2,200 scientists from more than 400 universities and companies use the NSLS for research in such diverse fields as biology, physics, chemistry, geology, medicine, and environmental and materials sciences. For example, researchers have used the NSLS to examine the minute details of computer chips, decipher the structures of viruses, probe the density of bone, determine the chemical composition of moon rocks, and reveal countless other mysteries of science. The facility has 65 operating beamlines, with 51 beamlines on the X-Ray Ring and 14 beamlines on the VUV-Infrared Ring. It runs seven days a week, 24 hours a day throughout the year, except during periods of maintenance and studies. Researchers are not charged for beam time, provided that the research results are published in open literature. Proprietary research is conducted on a full-cost-recovery basis. With close to 1,000 publications per year, the NSLS is one of the most prolific scientific facilities in the world. Among the many accolades given to its users and staff, the NSLS has won nine R&D 100 Awards for innovations ranging from a closed orbit feedback system to the first device able to focus a large spread of high-energy x-rays. In addition, a visiting NSLS researcher shared the 2003 Nobel Prize in Chemistry for work

  16. The absolute path command

    SciTech Connect

    Moody, A.

    2012-05-11

    The ap command traveres all symlinks in a given file, directory, or executable name to identify the final absolute path. It can print just the final path, each intermediate link along with the symlink chan, and the permissions and ownership of each directory component in the final path. It has functionality similar to "which", except that it shows the final path instead of the first path. It is also similar to "pwd", but it can provide the absolute path to a relative directory from the current working directory.

  17. Electromagnetic source imaging for sparse cortical activation patterns.

    PubMed

    von Ellenrieder, Nicolás; Hurtado, Martín; Muravchik, Carlos H

    2010-01-01

    We propose modifications to the Automatic Relevance Determination (ARD) algorithm for solving the EEG/MEG inverse problem when the activation map of the cortex is known to be sparse. We propose to include a term to account for the background noise activity, i.e. electric activity of sources not in the cortex. Also, we prune the results of the ARD algorithm using a Model Selection criterion to get sparser results. Simulations with a realistic head model show a very important reduction of the number of sources incorrectly detected as active.

  18. Absolute nuclear material assay using count distribution (LAMBDA) space

    DOEpatents

    Prasad, Mano K.; Snyderman, Neal J.; Rowland, Mark S.

    2015-12-01

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  19. Absolute nuclear material assay using count distribution (LAMBDA) space

    DOEpatents

    Prasad, Manoj K [Pleasanton, CA; Snyderman, Neal J [Berkeley, CA; Rowland, Mark S [Alamo, CA

    2012-06-05

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  20. What Carbon Sources Support Groundwater Microbial Activity in Riparian Forests?

    NASA Astrophysics Data System (ADS)

    Gurwick, N. P.; Groffman, P. M.; McCorkle, D. C.; Stolt, M. H.; Kellogg, D. Q.; Gold, A. J.

    2004-05-01

    A major question in riparian research is the source of energy to support subsurface microbial denitrification activity. The supply of microbially-available carbon frequently limits microbial activity in the subsurface. Therefore, identifying the relative importance of carbon sources in the riparian subsurface helps explain the sustainability and spatial heterogeneity of denitrification rates. We have investigated the importance of buried, carbon-rich soil horizons, deep roots and dissolved organic carbon as potential carbon sources to support groundwater denitrification in riparian forests in Rhode Island. We used field observations, laboratory incubations and in-situ experiments to evaluate these sources at four sites in different geomorphic settings. In particular, we measured the 14C-DIC signature and DIC concentration of ambient groundwater and groundwater that had been degassed, re-introduced into the well, and incubated in-situ. Buried horizons appear to be an important source of carbon in the subsurface, as shown by active respiration in laboratory incubations; greater microbial biomass in buried carbon-rich soils compared to surrounding carbon-poor soils; and the presence of very old carbon (>1,000 ybp) in DIC 225 cm beneath the surface. DIC collected from shallower wells showed no clear evidence of ancient carbon. Roots also appear to be important, creating hotspots of carbon availability and denitrification in the generally carbon poor subsurface matrix. Dissolved organic carbon did not stimulate denitrification in aquifer microcosms in the laboratory, suggesting that this was not an important carbon source for denitrification in our sites. Determining which carbon source is fueling denitrification has practical implications. Where buried horizons are the key source, surface management of the riparian zone will likely have little direct influence on groundwater denitrification. Where roots are the key source, changes in the plant community are likely to

  1. PoroTomo: Nodal Seismometer Active Source Data Sample

    SciTech Connect

    Kurt Feigl

    2016-03-25

    This data is in sac format and includes recordings of two active source events from 238 three-component nodal seismometers deployed at Bradys Hot Springs geothermal field as part of the PoroTomo project. The source was a viberoseis truck operating in P-wave vibrational mode and generating a swept-frequency signal. The files are 33 seconds long starting 4 seconds before each sweep was initiated. There is some overlap in the file times.

  2. Absolute quantitation of protein posttranslational modification isoform.

    PubMed

    Yang, Zhu; Li, Ning

    2015-01-01

    Mass spectrometry has been widely applied in characterization and quantification of proteins from complex biological samples. Because the numbers of absolute amounts of proteins are needed in construction of mathematical models for molecular systems of various biological phenotypes and phenomena, a number of quantitative proteomic methods have been adopted to measure absolute quantities of proteins using mass spectrometry. The liquid chromatography-tandem mass spectrometry (LC-MS/MS) coupled with internal peptide standards, i.e., the stable isotope-coded peptide dilution series, which was originated from the field of analytical chemistry, becomes a widely applied method in absolute quantitative proteomics research. This approach provides more and more absolute protein quantitation results of high confidence. As quantitative study of posttranslational modification (PTM) that modulates the biological activity of proteins is crucial for biological science and each isoform may contribute a unique biological function, degradation, and/or subcellular location, the absolute quantitation of protein PTM isoforms has become more relevant to its biological significance. In order to obtain the absolute cellular amount of a PTM isoform of a protein accurately, impacts of protein fractionation, protein enrichment, and proteolytic digestion yield should be taken into consideration and those effects before differentially stable isotope-coded PTM peptide standards are spiked into sample peptides have to be corrected. Assisted with stable isotope-labeled peptide standards, the absolute quantitation of isoforms of posttranslationally modified protein (AQUIP) method takes all these factors into account and determines the absolute amount of a protein PTM isoform from the absolute amount of the protein of interest and the PTM occupancy at the site of the protein. The absolute amount of the protein of interest is inferred by quantifying both the absolute amounts of a few PTM

  3. Mass variation in outcome to high production activity in Kamojang Geothermal Field, Indonesia: A reservoir monitoring with relative and absolute gravimetry

    NASA Astrophysics Data System (ADS)

    Sofyan, Y.; Kamah, Y.; Nishijima, J.; Fujimitsu, Y.; Ehara, S.; Fukuda, Y.; Taniguchi, M.

    2011-11-01

    The Kamojang Geothermal Field (KGF) is a typical vapor dominated hydrothermal system in west Java, Indonesia. This geothermal field is the oldest exploited geothermal field in Indonesia. From 1983 to 2005, more than 160 million tons of steam has been exploited from the KGF and more than 30 million tons of condensed water and river water were injected to the reservoir system. Regarding to the electricity demand, installed capacity of KGF increased from 30 MWe to 140 MWe in 1987 and 200 MWe in 2007. Mass variation in the geothermal reservoir can be measured by using the map of the gravity changes. Gravity changes observed in the KGF between 1999 and 2005 at 51 benchmarks are interpreted in terms of a change of mass. Concerning to the production mass increase, gravity changes also observed between 1999 and 2008 at 30 benchmarks. The recent gravity measurement was conducted using absolute gravimeter in 2009 and 2010 at 12 gravity benchmarks. Mass variation in the reservoir was caused by production and injection activities. Mass variation in KGF from 1999 to 2005 is about -3.34 Mt/year while is about -3.78 Mt/year from 1999 to 2008. Another period between 2009 and 2010, mass variation decreased about -8.24 Mt. According to the history of production and injection, natural recharge to the KGF's reservoir is estimated at about 2.77 Mt/year from 1999 to 2005 and 2.75 Mt/year from 1999 to 2008. Between 2009 and 2010, KGF has a bigger mass deficiency rate throughout 200 MWe maintain production.

  4. Absolute intensities of the γ-ray emissions originating from the electron capture decay of 153Gd

    NASA Astrophysics Data System (ADS)

    Shearman, R.; Collins, S. M.; Keightley, J. D.; Pearce, A. K.; Garnier, J.

    2017-09-01

    153Gd has widespread use, in non-destructive testing, as a line source in SPECT imaging and has been recently proposed as an in-vitro interstitial rotating shield brachytherapy (I-RSBT) source. In this work, the six most intense emissions in the de-excitation of the daughter nucleus 153Eu have been measured, with an improved accuracy and precision to γ-ray emission intensities reported previously, via two characterised HPGe spectrometers. A specific absolute activity of 512.5 (25) kBq g-1 was determined using the 4π (LS)-γ digital coincidence counting technique. This absolute activity was used to determine an absolute intensity for the 97.4 keV γ-ray emission of 30.15 (20) per 100 decays. The reported absolute emission intensity of this transition in this work has a relative difference of 4% from the currently recommended value.

  5. Absolute airborne gravimetry

    NASA Astrophysics Data System (ADS)

    Baumann, Henri

    This work consists of a feasibility study of a first stage prototype airborne absolute gravimeter system. In contrast to relative systems, which are using spring gravimeters, the measurements acquired by absolute systems are uncorrelated and the instrument is not suffering from problems like instrumental drift, frequency response of the spring and possible variation of the calibration factor. The major problem we had to resolve were to reduce the influence of the non-gravitational accelerations included in the measurements. We studied two different approaches to resolve it: direct mechanical filtering, and post-processing digital compensation. The first part of the work describes in detail the different mechanical passive filters of vibrations, which were studied and tested in the laboratory and later in a small truck in movement. For these tests as well as for the airborne measurements an absolute gravimeter FG5-L from Micro-G Ltd was used together with an Inertial navigation system Litton-200, a vertical accelerometer EpiSensor, and GPS receivers for positioning. These tests showed that only the use of an optical table gives acceptable results. However, it is unable to compensate for the effects of the accelerations of the drag free chamber. The second part describes the strategy of the data processing. It is based on modeling the perturbing accelerations by means of GPS, EpiSensor and INS data. In the third part the airborne experiment is described in detail, from the mounting in the aircraft and data processing to the different problems encountered during the evaluation of the quality and accuracy of the results. In the part of data processing the different steps conducted from the raw apparent gravity data and the trajectories to the estimation of the true gravity are explained. A comparison between the estimated airborne data and those obtained by ground upward continuation at flight altitude allows to state that airborne absolute gravimetry is feasible and

  6. Electronic Absolute Cartesian Autocollimator

    NASA Technical Reports Server (NTRS)

    Leviton, Douglas B.

    2006-01-01

    An electronic absolute Cartesian autocollimator performs the same basic optical function as does a conventional all-optical or a conventional electronic autocollimator but differs in the nature of its optical target and the manner in which the position of the image of the target is measured. The term absolute in the name of this apparatus reflects the nature of the position measurement, which, unlike in a conventional electronic autocollimator, is based absolutely on the position of the image rather than on an assumed proportionality between the position and the levels of processed analog electronic signals. The term Cartesian in the name of this apparatus reflects the nature of its optical target. Figure 1 depicts the electronic functional blocks of an electronic absolute Cartesian autocollimator along with its basic optical layout, which is the same as that of a conventional autocollimator. Referring first to the optical layout and functions only, this or any autocollimator is used to measure the compound angular deviation of a flat datum mirror with respect to the optical axis of the autocollimator itself. The optical components include an illuminated target, a beam splitter, an objective or collimating lens, and a viewer or detector (described in more detail below) at a viewing plane. The target and the viewing planes are focal planes of the lens. Target light reflected by the datum mirror is imaged on the viewing plane at unit magnification by the collimating lens. If the normal to the datum mirror is parallel to the optical axis of the autocollimator, then the target image is centered on the viewing plane. Any angular deviation of the normal from the optical axis manifests itself as a lateral displacement of the target image from the center. The magnitude of the displacement is proportional to the focal length and to the magnitude (assumed to be small) of the angular deviation. The direction of the displacement is perpendicular to the axis about which the

  7. The Role of Active-Source Seismology in Earthscope

    NASA Astrophysics Data System (ADS)

    Fuis, G. S.

    2006-12-01

    Through USArray, Earthscope will obtain an unprecedented image of chiefly the mantle beneath the USA. To maximize the usefulness of this image to earth scientists and to the public, features imaged in the mantle must be related to surface features that are dated. For example, observed bodies and discontinuities in the mantle must be related to orogens and sutures observable at the surface. Thus, the crust must be imaged in enough detail make the mantle-surface connections. Unfortunately, there are no plans and currently no funds to image the crust systematically at the required resolution. Active-source seismology is the chief investigative tool for imaging the crust. Active-source recorders are being purchased under the Earthscope MREFC (Major Research Equipment Facility Construction), but sources for active-source seismology must come from the Earthscope research program funding. Sources large enough and dense enough to investigate the crust at a desirable resolution are expensive, and the Earthscope research program funding may not be able to support systematic crustal imaging. Thus, we face the possibility that high-resolution images of the crust will be spatially very limited. Consequently, geologists and crustal geophysicists would have limited roles in Earthscope. In an attempt to change this situation, geologists and crustal geophysicists have proposed an initiative to study the crust (and upper mantle) of the USA in a systematic way to complement the ongoing passive-source imaging. This initiative will focus on megaswaths across the USA, which focus not only on major geologic provinces but also on the boundaries between provinces. The chief contribution of this initiative to Earthscope will be multidisciplinary studies, including active-source seismology, to provide a connection between features imaged in the mantle and outcrops at the surface. LITHOPROBE, a major achievement by Canadian earth scientists, provides a useful model for the active- source

  8. Absolute-structure reports.

    PubMed

    Flack, Howard D

    2013-08-01

    All the 139 noncentrosymmetric crystal structures published in Acta Crystallographica Section C between January 2011 and November 2012 inclusive have been used as the basis of a detailed study of the reporting of absolute structure. These structure determinations cover a wide range of space groups, chemical composition and resonant-scattering contribution. Defining A and D as the average and difference of the intensities of Friedel opposites, their level of fit has been examined using 2AD and selected-D plots. It was found, regardless of the expected resonant-scattering contribution to Friedel opposites, that the Friedel-difference intensities are often dominated by random uncertainty and systematic error. An analysis of data collection strategy is provided. It is found that crystal-structure determinations resulting in a Flack parameter close to 0.5 may not necessarily be from crystals twinned by inversion. Friedifstat is shown to be a robust estimator of the resonant-scattering contribution to Friedel opposites, very little affected by the particular space group of a structure nor by the occupation of special positions. There is considerable confusion in the text of papers presenting achiral noncentrosymmetric crystal structures. Recommendations are provided for the optimal way of treating noncentrosymmetric crystal structures for which the experimenter has no interest in determining the absolute structure.

  9. Activating and Sedating Adverse Effects of Second-Generation Antipsychotics in the Treatment of Schizophrenia and Major Depressive Disorder: Absolute Risk Increase and Number Needed to Harm.

    PubMed

    Citrome, Leslie

    2017-04-01

    Activating and sedating adverse effects of antipsychotics can be obstacles to their use. This study quantified the activating and sedating properties of first-line oral second-generation antipsychotics by examining the rates of adverse reactions as reported in product labeling for the indications of schizophrenia and adjunctive treatment of major depressive disorder. Additional data sources included regulatory documents, study synopses, and published study reports. Attributable risk increase and number needed to harm (NNH) were calculated for each agent versus placebo. Heterogeneity among the different antipsychotics regarding activating or sedating adverse events was observed, with some agents displaying the potential for both activating and sedating properties. For agents indicated for the treatment of schizophrenia, predominantly activating medications include lurasidone (NNH, 11 for akathisia vs 20 for somnolence) and cariprazine (NNH, 15 for akathisia vs 65 for somnolence-combined terms). Similarly activating and sedating are risperidone (NNH, 15 for akathisia vs 13 for sedation) and aripiprazole (NNH, 31 for akathisia vs 34 for somnolence). Predominantly sedating are olanzapine, quetiapine immediate and extended release, ziprasidone, asenapine, and iloperidone. Agents that are neither activating nor sedating are paliperidone and brexpiprazole. For major depressive disorder, the overall findings regarding activation and sedation appear similar to those seen with schizophrenia. Data extracted were limited to those available from registrational studies that contributed to the adverse event tables contained in the product labels. Postregistrational comparative studies may yield different outcomes. Differences in tolerability profiles regarding activation and sedation have implications in terms of selecting the optimal antipsychotic for a given individual.

  10. Advanced Light Source Activity Report 1997/1998

    SciTech Connect

    Greiner, Annette

    1999-03-01

    This Lawrence Berkeley National Laboratory, Advanced Light Source (ALS) activity report for 1997/98 discusses the following topics: Introduction and Overview; Science Highlights; Facility Report; Special Events; ALS Advisory Panels 1997/98; ALS Staff 1997/98 and Facts and Figures for the year.

  11. Source analysis of MEG activities during sleep (abstract)

    NASA Astrophysics Data System (ADS)

    Ueno, S.; Iramina, K.

    1991-04-01

    The present study focuses on magnetic fields of the brain activities during sleep, in particular on K-complexes, vertex waves, and sleep spindles in human subjects. We analyzed these waveforms based on both topographic EEG (electroencephalographic) maps and magnetic fields measurements, called MEGs (magnetoencephalograms). The components of magnetic fields perpendicular to the surface of the head were measured using a dc SQUID magnetometer with a second derivative gradiometer. In our computer simulation, the head is assumed to be a homogeneous spherical volume conductor, with electric sources of brain activity modeled as current dipoles. Comparison of computer simulations with the measured data, particularly the MEG, suggests that the source of K-complexes can be modeled by two current dipoles. A source for the vertex wave is modeled by a single current dipole which orients along the body axis out of the head. By again measuring the simultaneous MEG and EEG signals, it is possible to uniquely determine the orientation of this dipole, particularly when it is tilted slightly off-axis. In sleep stage 2, fast waves of magnetic fields consistently appeared, but EEG spindles appeared intermittently. The results suggest that there exist sources which are undetectable by electrical measurement but are detectable by magnetic-field measurement. Such source can be described by a pair of opposing dipoles of which directions are oppositely oriented.

  12. Absolute Distance Measurement with the MSTAR Sensor

    NASA Technical Reports Server (NTRS)

    Lay, Oliver P.; Dubovitsky, Serge; Peters, Robert; Burger, Johan; Ahn, Seh-Won; Steier, William H.; Fetterman, Harrold R.; Chang, Yian

    2003-01-01

    The MSTAR sensor (Modulation Sideband Technology for Absolute Ranging) is a new system for measuring absolute distance, capable of resolving the integer cycle ambiguity of standard interferometers, and making it possible to measure distance with sub-nanometer accuracy. The sensor uses a single laser in conjunction with fast phase modulators and low frequency detectors. We describe the design of the system - the principle of operation, the metrology source, beamlaunching optics, and signal processing - and show results for target distances up to 1 meter. We then demonstrate how the system can be scaled to kilometer-scale distances.

  13. Absolute measurement of hyperspectral and angular reflection.

    PubMed

    Hwang, Jisoo

    2014-09-20

    A new instrument for absolute measurement of hyperspectral and angular reflection is presented. The instrument determines absolute values of angular reflection quantities in a wavelength range from 380 to 780 nm with a 3 nm spectral resolution by using a white source and a CCD-based spectroradiometer. Through uncertainty evaluation, the measurement uncertainty is determined as 1.4%-2.9% (k=2) for white diffuse material of Spectralon. The gonioreflectometric determination and an integrating-sphere-based reflection measurement traceable to KRISS spectral reflectance scale are compared by determining hemispherical reflectance, which results in agreement in their uncertainties.

  14. Public health genetic counselors: activities, skills, and sources of learning.

    PubMed

    McWalter, Kirsty M; Sdano, Mallory R; Dave, Gaurav; Powell, Karen P; Callanan, Nancy

    2015-06-01

    Specialization within genetic counseling is apparent, with 29 primary specialties listed in the National Society of Genetic Counselors' 2012 Professional Status Survey (PSS). PSS results show a steady proportion of genetic counselors primarily involved in public health, yet do not identify all those performing public health activities. Little is known about the skills needed to perform activities outside of "traditional" genetic counselor roles and the expertise needed to execute those skills. This study aimed to identify genetic counselors engaging in public health activities, the skills used, and the most influential sources of learning for those skills. Participants (N = 155) reported involvement in several public health categories: (a) Education of Public and/or Health Care Providers (n = 80, 52 %), (b) Population-Based Screening Programs (n = 70, 45 %), (c) Lobbying/Public Policy (n = 62, 40 %), (d) Public Health Related Research (n = 47, 30 %), and (e) State Chronic Disease Programs (n = 12, 8 %). Regardless of category, "on the job" was the most common primary source of learning. Genetic counseling training program was the most common secondary source of learning. Results indicate that the number of genetic counselors performing public health activities is likely higher than PSS reports, and that those who may not consider themselves "public health genetic counselors" do participate in public health activities. Genetic counselors learn a diverse skill set in their training programs; some skills are directly applicable to public health genetics, while other public health skills require additional training and/or knowledge.

  15. Absolute Equilibrium Entropy

    NASA Technical Reports Server (NTRS)

    Shebalin, John V.

    1997-01-01

    The entropy associated with absolute equilibrium ensemble theories of ideal, homogeneous, fluid and magneto-fluid turbulence is discussed and the three-dimensional fluid case is examined in detail. A sigma-function is defined, whose minimum value with respect to global parameters is the entropy. A comparison is made between the use of global functions sigma and phase functions H (associated with the development of various H-theorems of ideal turbulence). It is shown that the two approaches are complimentary though conceptually different: H-theorems show that an isolated system tends to equilibrium while sigma-functions allow the demonstration that entropy never decreases when two previously isolated systems are combined. This provides a more complete picture of entropy in the statistical mechanics of ideal fluids.

  16. Absolute Bioavailability of Tasimelteon.

    PubMed

    Torres, Rosarelis; Dressman, Marlene A; Kramer, William G; Baroldi, Paolo

    2015-01-01

    Tasimelteon is a novel dual melatonin receptor agonist and is the first treatment approved by the US Food and Drug Administration for Non-24-Hour Sleep-Wake Disorder. This study was conducted to assess the absolute bioavailability of tasimelteon and to further assess the single-dose pharmacokinetics, safety, and tolerability of oral and intravenous (IV) routes of administration of the drug. This study was an open-label, single-dose, randomized, 2-period, 2-treatment, 2-sequence, crossover study in which 14 healthy volunteers were randomly administered tasimelteon as either a 20-mg capsule or IV administration of 2 mg infused over 30 minutes. Each subject received both treatments in a random order, separated by a washout period of 5 ± 2 days. The total clearance and volume of distribution of tasimelteon, from the IV treatment, were 505 mL per minute and 42.7 L, respectively. Based on the statistical comparison of dose-corrected area under the curve to infinity, the absolute bioavailability was 38%, with a 90% confidence interval of 27%-54%. The mean elimination half-life was the same for the oral and IV routes. The exposure ratios, oral-to-IV, for metabolites M9, M11, M12, and M13, were 133.27%, 118.28%, 138.76%, and 112.36%, respectively, suggesting presystemic or first-pass metabolism. Three (21.4%) subjects experienced a treatment-emergent adverse event (TEAE) during the study. All TEAEs were mild, considered related to study medication, and consistent with what has been seen in other studies. There were no deaths, serious adverse events, or discontinuations due to TEAEs. Both tasimelteon treatments were well tolerated during the study.

  17. Absolute multilateration between spheres

    NASA Astrophysics Data System (ADS)

    Muelaner, Jody; Wadsworth, William; Azini, Maria; Mullineux, Glen; Hughes, Ben; Reichold, Armin

    2017-04-01

    Environmental effects typically limit the accuracy of large scale coordinate measurements in applications such as aircraft production and particle accelerator alignment. This paper presents an initial design for a novel measurement technique with analysis and simulation showing that that it could overcome the environmental limitations to provide a step change in large scale coordinate measurement accuracy. Referred to as absolute multilateration between spheres (AMS), it involves using absolute distance interferometry to directly measure the distances between pairs of plain steel spheres. A large portion of each sphere remains accessible as a reference datum, while the laser path can be shielded from environmental disturbances. As a single scale bar this can provide accurate scale information to be used for instrument verification or network measurement scaling. Since spheres can be simultaneously measured from multiple directions, it also allows highly accurate multilateration-based coordinate measurements to act as a large scale datum structure for localized measurements, or to be integrated within assembly tooling, coordinate measurement machines or robotic machinery. Analysis and simulation show that AMS can be self-aligned to achieve a theoretical combined standard uncertainty for the independent uncertainties of an individual 1 m scale bar of approximately 0.49 µm. It is also shown that combined with a 1 µm m-1 standard uncertainty in the central reference system this could result in coordinate standard uncertainty magnitudes of 42 µm over a slender 1 m by 20 m network. This would be a sufficient step change in accuracy to enable next generation aerospace structures with natural laminar flow and part-to-part interchangeability.

  18. Experiment in New Madrid Zone to employ active source

    NASA Astrophysics Data System (ADS)

    Langston, Charles A.; Mooney, Walter; Bodin, Paul; Powell, Christine; Withers, Mitch

    An active source seismic experiment is scheduled for the end of October in the central United States' New Madrid Seismic Zone (NMSZ). Researchers from the center for Earthquake Research and Information (CERI) of the University of Memphis and the U.S. Geological Survey are planning 2600-lb and 5000-lb explosions at the southern and northern ends of the NMSZ, respectively. Broadband seismic instruments, other temporary broadband seismic stations, and an array of accelerographs near each source will record the large surface waves generated by the explosions in the unconsolidated sediments of the Mississippi embayment.

  19. Absolutely relative or relatively absolute: violations of value invariance in human decision making.

    PubMed

    Teodorescu, Andrei R; Moran, Rani; Usher, Marius

    2016-02-01

    Making decisions based on relative rather than absolute information processing is tied to choice optimality via the accumulation of evidence differences and to canonical neural processing via accumulation of evidence ratios. These theoretical frameworks predict invariance of decision latencies to absolute intensities that maintain differences and ratios, respectively. While information about the absolute values of the choice alternatives is not necessary for choosing the best alternative, it may nevertheless hold valuable information about the context of the decision. To test the sensitivity of human decision making to absolute values, we manipulated the intensities of brightness stimuli pairs while preserving either their differences or their ratios. Although asked to choose the brighter alternative relative to the other, participants responded faster to higher absolute values. Thus, our results provide empirical evidence for human sensitivity to task irrelevant absolute values indicating a hard-wired mechanism that precedes executive control. Computational investigations of several modelling architectures reveal two alternative accounts for this phenomenon, which combine absolute and relative processing. One account involves accumulation of differences with activation dependent processing noise and the other emerges from accumulation of absolute values subject to the temporal dynamics of lateral inhibition. The potential adaptive role of such choice mechanisms is discussed.

  20. The Activation Detector Activity Calculations Using the Effective Source Method and Measurement

    NASA Astrophysics Data System (ADS)

    Smutný, Vladimir; Konečná, Alena; Sprinzl, Daniel; Klupák, Vít; Vinš, Miroslav

    2017-09-01

    In the paper the application of effective source to the solution of activation detector activities in the reactor pressure vessel cavity of the VVER-1000 reactor is presented. The effective source method applies the Boltzmann transport operator to time integrated source data to obtain detector activities. Weighting the source data by time dependent depletion of the detector activity, the result of the calculation is the detector activity. The approach works because of the inherent linearity of radiation transport in non-multiplying time-invariant media. Integrated in this way, the source data are referred to as the `effective source'. The effective source method thereby enables the analyst to replace numerous intensive transport calculations with a single transport calculation in which the time dependence and magnitude of the source are correctly represented. Detailed description of the effective source method is presented in previous works. First, there were performed neutron-physical calculations of few real VVER-1000 cycles using MOBY-DICK macrocode. Second, there follows 3-D transport calculation using the deterministic code TORT and the cross section library BUGLE-B7 and obtained results are presented. These calculation results of activation detector activities in the reactor cavity are compared with relevant activation detectors results of the ex-vessel measurement. The comparison between calculation and measurement of activation detectors activity in the reactor cavity is necessary to the calculation quality verifying for further fast neutron fluence onto the reactor pressure vessel credible calculation. The activation detectors positions are evident from Figs 1, 2, 3.

  1. Positioning, alignment and absolute pointing of the ANTARES neutrino telescope

    NASA Astrophysics Data System (ADS)

    Fehr, F.; Distefano, C.; Antares Collaboration

    2010-01-01

    A precise detector alignment and absolute pointing is crucial for point-source searches. The ANTARES neutrino telescope utilises an array of hydrophones, tiltmeters and compasses for the relative positioning of the optical sensors. The absolute calibration is accomplished by long-baseline low-frequency triangulation of the acoustic reference devices in the deep-sea with a differential GPS system at the sea surface. The absolute pointing can be independently verified by detecting the shadow of the Moon in cosmic rays.

  2. Sources of solar wind over the solar activity cycle

    PubMed Central

    Poletto, Giannina

    2012-01-01

    Fast solar wind has been recognized, about 40 years ago, to originate in polar coronal holes (CHs), that, since then, have been identified with sources of recurrent high speed wind streams. As of today, however, there is no general consensus about whether there are, within CHs, preferential locations where the solar wind is accelerated. Knowledge of slow wind sources is far from complete as well. Slow wind observed in situ can be traced back to its solar source by backward extrapolation of magnetic fields whose field lines are streamlines of the outflowing plasma. However, this technique often has not the necessary precision for an indisputable identification of the region where wind originates. As the Sun progresses through its activity cycle, different wind sources prevail and contribute to filling the heliosphere. Our present knowledge of different wind sources is here summarized. Also, a Section addresses the problem of wind acceleration in the low corona, as inferred from an analysis of UV data, and illustrates changes between fast and slow wind profiles and possible signatures of changes along the solar cycle. A brief reference to recent work about the deep roots of solar wind and their changes over different solar cycles concludes the review. PMID:25685421

  3. Sources of solar wind over the solar activity cycle.

    PubMed

    Poletto, Giannina

    2013-05-01

    Fast solar wind has been recognized, about 40 years ago, to originate in polar coronal holes (CHs), that, since then, have been identified with sources of recurrent high speed wind streams. As of today, however, there is no general consensus about whether there are, within CHs, preferential locations where the solar wind is accelerated. Knowledge of slow wind sources is far from complete as well. Slow wind observed in situ can be traced back to its solar source by backward extrapolation of magnetic fields whose field lines are streamlines of the outflowing plasma. However, this technique often has not the necessary precision for an indisputable identification of the region where wind originates. As the Sun progresses through its activity cycle, different wind sources prevail and contribute to filling the heliosphere. Our present knowledge of different wind sources is here summarized. Also, a Section addresses the problem of wind acceleration in the low corona, as inferred from an analysis of UV data, and illustrates changes between fast and slow wind profiles and possible signatures of changes along the solar cycle. A brief reference to recent work about the deep roots of solar wind and their changes over different solar cycles concludes the review.

  4. Active elements of film sources of sound-thermophones

    NASA Astrophysics Data System (ADS)

    Vasiliev, B. P.; Legusha, F. F.; Rezrezova, K. V.; Chizhov, G. V.

    2017-05-01

    The report examines the device and factors affecting the acoustic efficiency of thermoacoustic sound sources - thermophones. Film thermophones are studied, the structure of which is made in the form of a system of layers. Thermophones can be considered as an example of the practical application of films and coatings to ensure the operation of physical instruments. A great importance for the work of thermophones is the quality of the production of thin films, which are their active elements.

  5. Obsidian sources characterized by neutron-activation analysis.

    PubMed

    Gordus, A A; Wright, G A; Griffin, J B

    1968-07-26

    Concentrations of elements such as manganese, scandium, lanthanum, rubidium, samarium, barium, and zirconium in obsidian samples from different flows show ranges of 1000 percent or more, whereas the variation in element content in obsidian samples from a single flow appears to be less than 40 percent. Neutron-activation analysis of these elements, as well as of sodium and iron, provides a means of identifying the geologic source of an archeological artifact of obsidian.

  6. A computerized system for localizing sources of cardiac activation.

    PubMed

    Salu, Y; Mehrotra, P

    1984-06-01

    A noninvasive method for locating a source of cardiac electrical activity is described. The data acquisition and its preliminary processing is done with the aid of a microcomputer, while lengthier calculations are done on a large computer. The method was tested on 18 patients, and the results indicate that it is reliable, and with further technical refinements it could be used in research and clinical settings.

  7. Enantioseparation, absolute configuration determination, and anticonvulsant activity of (+/-)-1-(4-aminophenyl)-7,8-methylenedioxy-1,2,3,5-tetrahydro-4H-2,3-benzodiazepin-4-one.

    PubMed

    Calabrò, Maria Luisa; Raneri, Daniela; Ficarra, Paola; Ferreri, Guido; De Sarro, Giovambattista; Bruno, Giuseppe; Zappalà, Maria; Micale, Nicola; Grasso, Silvana

    2007-01-01

    The resolution of 1-(4-aminophenyl)-7,8-methylenedioxy-1,2,3,5-tetrahydro-4H-benzodiazepin-4-one (+/-)-(R,S)-2 was accomplished by chiral HPLC. The absolute configuration of (+)-2, determined by X-ray crystallographic analysis, was R. The in vivo anticonvulsant activity of the enantiomers (+)-(R)-2 and (-)-(S)-2 is reported. It has been also demonstrated that compound (+/-)-(R,S)-2 in vivo undergoes oxidative metabolism to derivative 1.

  8. New sources and antifungal activity of sesquiterpene lactones.

    PubMed

    Barrero, A F; Oltra, J E; Alvarez, M; Raslan, D S; Saúde, D A; Akssira, M

    2000-02-01

    In the search for new sources of sesquiterpene lactones, six Centaurea species have been analyzed. The activity against the fungus Cunninghamella echinulata of (+)-cnicin (1) and (+)-salonitenolide (2), isolated from the Centaurea plants, as well as that of (+)-costunolide (3), (-)-dehydrocostuslactone (4), (-)-lychnopholide (5) and (-)-eremantholide C (6), has been evaluated. Compounds 3 and 4 showed noticeable EC50 values, whilst more polar lactones were inactive. These results suggest that a relatively low polarity is one of the molecular requirements for the antifungal activity of sesquiterpene lactones.

  9. The effect of light-activation sources on tooth bleaching

    PubMed Central

    Baroudi, Kusai; Hassan, Nadia Aly

    2014-01-01

    Vital bleaching is one of the most requested cosmetic dental procedures asked by patients who seek a more pleasing smile. This procedure consists of carbamide or hydrogen peroxide gel applications that can be applied in-office or by the patient (at-home/overnight bleaching system). Some in-office treatments utilise whitening light with the objective of speeding up the whitening process. The objective of this article is to review and summarise the current literature with regard to the effect of light-activation sources on in-office tooth bleaching. A literature search was conducted using Medline, accessed via the National Library of Medicine Pub Med from 2003 to 2013 searching for articles relating to effectiveness of light activation sources on in-office tooth bleaching. This study found conflicting evidence on whether light truly improve tooth whitening. Other factors such as, type of stain, initial tooth colour and subject age which can influence tooth bleaching outcome were discussed. Conclusions: The use of light activator sources with in-office bleaching treatment of vital teeth did not increase the efficacy of bleaching or accelerate the bleaching. PMID:25298598

  10. The effect of light-activation sources on tooth bleaching.

    PubMed

    Baroudi, Kusai; Hassan, Nadia Aly

    2014-09-01

    Vital bleaching is one of the most requested cosmetic dental procedures asked by patients who seek a more pleasing smile. This procedure consists of carbamide or hydrogen peroxide gel applications that can be applied in-office or by the patient (at-home/overnight bleaching system). Some in-office treatments utilise whitening light with the objective of speeding up the whitening process. The objective of this article is to review and summarise the current literature with regard to the effect of light-activation sources on in-office tooth bleaching. A literature search was conducted using Medline, accessed via the National Library of Medicine Pub Med from 2003 to 2013 searching for articles relating to effectiveness of light activation sources on in-office tooth bleaching. This study found conflicting evidence on whether light truly improve tooth whitening. Other factors such as, type of stain, initial tooth colour and subject age which can influence tooth bleaching outcome were discussed. The use of light activator sources with in-office bleaching treatment of vital teeth did not increase the efficacy of bleaching or accelerate the bleaching.

  11. Prevalent glucocorticoid and androgen activity in US water sources.

    PubMed

    Stavreva, Diana A; George, Anuja A; Klausmeyer, Paul; Varticovski, Lyuba; Sack, Daniel; Voss, Ty C; Schiltz, R Louis; Blazer, Vicki S; Iwanowicz, Luke R; Hager, Gordon L

    2012-01-01

    Contamination of the environment with endocrine disrupting chemicals (EDCs) is a major health concern. The presence of estrogenic compounds in water and their deleterious effect are well documented. However, detection and monitoring of other classes of EDCs is limited. Here we utilize a high-throughput live cell assay based on sub-cellular relocalization of GFP-tagged glucocorticoid and androgen receptors (GFP-GR and GFP-AR), in combination with gene transcription analysis, to screen for glucocorticoid and androgen activity in water samples. We report previously unrecognized glucocorticoid activity in 27%, and androgen activity in 35% of tested water sources from 14 states in the US. Steroids of both classes impact body development, metabolism, and interfere with reproductive, endocrine, and immune systems. This prevalent contamination could negatively affect wildlife and human populations.

  12. Prevalent flucocorticoid and androgen activity in US water sources

    USGS Publications Warehouse

    Stavreva, Diana A.; George, Anuja A.; Klausmeyer, Paul; Varticovski, Lyuba; Sack, Daniel; Voss, Ty C.; Schiltz, R. Louis; Blazer, Vicki; Iwanowiczl, Luke R.; Hager, Gordon L.

    2012-01-01

    Contamination of the environment with endocrine disrupting chemicals (EDCs) is a major health concern. The presence of estrogenic compounds in water and their deleterious effect are well documented. However, detection and monitoring of other classes of EDCs is limited. Here we utilize a high-throughput live cell assay based on sub-cellular relocalization of GFP-tagged glucocorticoid and androgen receptors (GFP-GR and GFP-AR), in combination with gene transcription analysis, to screen for glucocorticoid and androgen activity in water samples. We report previously unrecognized glucocorticoid activity in 27%, and androgen activity in 35% of tested water sources from 14 states in the US. Steroids of both classes impact body development, metabolism, and interfere with reproductive, endocrine, and immune systems. This prevalent contamination could negatively affect wildlife and human populations.

  13. Methodology for a bounding estimate of activation source-term.

    PubMed

    Culp, Todd

    2013-02-01

    Sandia National Laboratories' Z-Machine is the world's most powerful electrical device, and experiments have been conducted that make it the world's most powerful radiation source. Because Z-Machine is used for research, an assortment of materials can be placed into the machine; these materials can be subjected to a range of nuclear reactions, producing an assortment of activation products. A methodology was developed to provide a systematic approach to evaluate different materials to be introduced into the machine as wire arrays. This methodology is based on experiment specific characteristics, physical characteristics of specific radionuclides, and experience with Z-Machine. This provides a starting point for bounding calculations of radionuclide source-term that can be used for work planning, development of work controls, and evaluating materials for introduction into the machine.

  14. Two rare-class tricyclic diterpenes with antitubercular activity from the Caribbean sponge Svenzea flava. Application of vibrational circular dichroism spectroscopy for determining absolute configuration.

    PubMed

    Avilés, Edward; Rodríguez, Abimael D; Vicente, Jan

    2013-11-15

    Two new natural products, 3 and 4, and their predecessor 7-isocyanoisoneoamphilecta-1(14),15-diene (2), of the rare isoneoamphilectane class of marine diterpenes, along with the known amphilectane diterpenes 6-8, were isolated from the n-hexane extract of the marine sponge Svenzea flava collected at Great Inagua Island, Bahamas. The molecular structures of compounds 3 and 4 were established by spectroscopic (1D/2D NMR, IR, UV, HRMS) methods and confirmed by a series of chemical correlation studies. In a first ever case study of the assignment of the absolute configuration of a molecule based on the isoneoamphilectane carbon skeleton, the absolute configuration of compound 5 was established as 3S,4R,7S,8S,11R,12S,13R by application of vibrational circular dichroism (VCD). In vitro anti-TB screenings revealed that metabolites 2-4 and, in particular, semisynthetic analogue 5, are strong growth inhibitors of Mycobacterium tuberculosis H37Rv.

  15. 5.0. Depletion, activation, and spent fuel source terms

    SciTech Connect

    Wieselquist, William A.

    2016-04-01

    SCALE’s general depletion, activation, and spent fuel source terms analysis capabilities are enabled through a family of modules related to the main ORIGEN depletion/irradiation/decay solver. The nuclide tracking in ORIGEN is based on the principle of explicitly modeling all available nuclides and transitions in the current fundamental nuclear data for decay and neutron-induced transmutation and relies on fundamental cross section and decay data in ENDF/B VII. Cross section data for materials and reaction processes not available in ENDF/B-VII are obtained from the JEFF-3.0/A special purpose European activation library containing 774 materials and 23 reaction channels with 12,617 neutron-induced reactions below 20 MeV. Resonance cross section corrections in the resolved and unresolved range are performed using a continuous-energy treatment by data modules in SCALE. All nuclear decay data, fission product yields, and gamma-ray emission data are developed from ENDF/B-VII.1 evaluations. Decay data include all ground and metastable state nuclides with half-lives greater than 1 millisecond. Using these data sources, ORIGEN currently tracks 174 actinides, 1149 fission products, and 974 activation products. The purpose of this chapter is to describe the stand-alone capabilities and underlying methodology of ORIGEN—as opposed to the integrated depletion capability it provides in all coupled neutron transport/depletion sequences in SCALE, as described in other chapters.

  16. Absolute Identification by Relative Judgment

    ERIC Educational Resources Information Center

    Stewart, Neil; Brown, Gordon D. A.; Chater, Nick

    2005-01-01

    In unidimensional absolute identification tasks, participants identify stimuli that vary along a single dimension. Performance is surprisingly poor compared with discrimination of the same stimuli. Existing models assume that identification is achieved using long-term representations of absolute magnitudes. The authors propose an alternative…

  17. Active and retired public employees' health insurance: potential data sources.

    PubMed

    Morrill, Melinda Sandler

    2014-12-01

    Employer-provided health insurance for public sector workers is a significant public policy issue. Underfunding and the growing costs of benefits may hinder the fiscal solvency of state and local governments. Findings from the private sector may not be applicable because many public sector workers are covered by union contracts or salary schedules and often benefit modifications require changes in legislation. Research has been limited by the difficulty in obtaining sufficiently large and representative data on public sector employees. This article highlights data sources researchers might utilize to investigate topics concerning health insurance for active and retired public sector employees.

  18. Verification of Minimum Detectable Activity for Radiological Threat Source Search

    NASA Astrophysics Data System (ADS)

    Gardiner, Hannah; Myjak, Mitchell; Baciak, James; Detwiler, Rebecca; Seifert, Carolyn

    2015-10-01

    The Department of Homeland Security's Domestic Nuclear Detection Office is working to develop advanced technologies that will improve the ability to detect, localize, and identify radiological and nuclear sources from airborne platforms. The Airborne Radiological Enhanced-sensor System (ARES) program is developing advanced data fusion algorithms for analyzing data from a helicopter-mounted radiation detector. This detector platform provides a rapid, wide-area assessment of radiological conditions at ground level. The NSCRAD (Nuisance-rejection Spectral Comparison Ratios for Anomaly Detection) algorithm was developed to distinguish low-count sources of interest from benign naturally occurring radiation and irrelevant nuisance sources. It uses a number of broad, overlapping regions of interest to statistically compare each newly measured spectrum with the current estimate for the background to identify anomalies. We recently developed a method to estimate the minimum detectable activity (MDA) of NSCRAD in real time. We present this method here and report on the MDA verification using both laboratory measurements and simulated injects on measured backgrounds at or near the detection limits. This work is supported by the US Department of Homeland Security, Domestic Nuclear Detection Office, under competitively awarded contract/IAA HSHQDC-12-X-00376. This support does not constitute an express or implied endorsement on the part of the Gov't.

  19. Monitoring seismic wave speed by an active seismic source

    NASA Astrophysics Data System (ADS)

    Yokoyama, K.; Kawakata, H.; Doi, I.; Okubo, M.; Saiga, A.

    2012-12-01

    Decreases in elastic wave speed around cracked zones prior to faulting in rock fracture experiments have been reported (e.g., Yukutake, 1989; Yoshimitsu et al., 2009). These decreases in wave speed have been considered to be associated with crack and fault growth based on non-destructive observation using X-ray CT scan (Kawakata et al., 1999). Meanwhile, there were some reports on the decreases in seismic wave speed along paths that cross the hypocentral area in periods including some large earthquakes. Uchida et al. (2002) analyzed seismic waveform with explosive sources before and after the 1998 northern Iwate prefecture earthquake, and they showed that the decrease in seismic wave speed approximately 0.1-0.9 % by the earthquake occurrence. Justin et al. (2007) reported the reduction in seismic wave speed accompanied with the 2003 Tokachi oki earthquake around the rupture area by using the four repeating earthquakes that occurred before and after the 2003 Tokachi oki earthquake. However, seismograms of explosive sources or repeating earthquakes are hard to be frequently recorded, which makes the time intervals of estimated seismic wave speed be too long to distinguish preseismic changes from coseismic and post seismic changes. In order to monitor crustal structures and detecting the variation of rock properties in the crust, a kind of active seismic source systems ACROSS (Accurately Controlled Routinely Operated Signal System) has been developed(e.g., Kunitomo and Kumazawa, 2004). We used the controlled seismic source ACROSS, which installed at the Tono mine, Gifu prefecture, central Japan and has been routinely operated by Tono Geoscience center of JAEA (Japan Atomic Energy Agency), automatically. Frequency modulated seismic waves are continuously radiated from approximately 10-20 Hz by eccentric rotation of the source. In order to investigate the stability of ACROSS signals, we used seismograms recorded at the 110m depth of Shobasama observing site, which is

  20. Active plasma source formation in the MAP diode

    SciTech Connect

    Lamppa, K.P.; Stinnett, R.W.; Renk, T.J.

    1995-07-01

    The Ion Beam Surface Treatment (IBEST) program is exploring using ion beams to treat the surface of a wide variety of materials. These experiments have shown that improved corrosion resistance, surface hardening, grain size modification, polishing and surface cleaning can all be achieved using a pulsed 0.4-0.8 MeV ion beam delivering 1-10 J/cm{sup 2}. The Magnetically-confined Anode Plasma (MAP) diode, developed at Cornell University, produces an active plasma which can be used to treat the surfaces of materials. The diode consists of a fast puff valve as the source of gas to produce the desired ions and two capacitively driven B-fields. A slow magnetic field is used for electron insulation and a fast field is used to both ionize the puffed gas and to position the plasma in the proper spatial location in the anode prior to the accelerator pulse. The relative timing between subsystems is an important factor in the effective production of the active plasma source for the MAP diode system. The MAP diode has been characterized using a Langmuir probe to measure plasma arrival times at the anode annulus for hydrogen gas. This data was then used to determine the optimum operating point for the MAP diode on RHEPP-1 accelerator shots. Operation of the MAP diode system to produce an ion beam of 500 kV, 12 kA with 40% efficiency (measured at the diode) has been demonstrated.

  1. The Absolute Solar Irradiance Spectrum at Solar Minimum Activity Measured by the SOLSPEC and SOL-ACES Spectrometers from 17 to 3000 nm Placed on Board the International Space Station

    NASA Astrophysics Data System (ADS)

    Thuillier, Gerard; Bolsee, David; Schmidtke, Gerhard; Schmutz, Werner; Shapiro, Alexander; Nikutowski, Bernd

    Two instruments placed on the COLOMBUS laboratory on the International Space Station constitute a payload named SOLAR measuring the spectral solar irradiance from 17 to 3000 nm for solar, atmospheric and climatology physics for which the sun-climate connection also re-quires the precise and absolute knowledge of the solar spectral irradiance. Given the significant improvements in atmosphere, climate and solar modelling, accurate data are needed. SOL-SPEC primary objectives are the measurement of the Sun absolute spectral irradiance and its variability from 165 to 3080 nm. SOLSPEC has been developed by LATMOS (France), Institut d'Aéronomie Spatiale (Belgique), and Landessternwarte (Germany). It has been calibrated in the absolute scale by using the blackbody of the Physikalisch-Technische Bundesanstalt (PTB), Braunschweig. SOL-ACES primary objectives are the measurements of the Sun absolute spec-tral irradiance from 17 to 140 nm. This instrument as developed by the Fraunhofer Institute (Freiburg, Germany) uses three-current ionisation chambers repeatedly filled with different gases to re-calibrate the three spectrometers, which are changing their efficiencies e.g. by the interaction with solar radiation. We present a composite solar spectrum for the July 2008 period, at a very low solar as occurred at the end of solar cycle 23. It has been built using SOLSPEC, SOL-ACES and TIMED SEE data. Comparison with data obtained during the ATLAS 3 period (November 1994), SORCE measurements and theoretical modelling using the COSI code will be presented. Differences will be commented (difference of the two activity levels, accuracy).

  2. Fundamentals of absolute pyroheliometry and objective characterization. [using a narrow field of view radiometer

    NASA Technical Reports Server (NTRS)

    Crommelynck, D. A.

    1982-01-01

    The radiometric methodology in use with a narrow field of view radiometer for observation of the solar constant is described. The radiation output of the Sun is assumed to be constant, enabling the monitoring of the solar source by an accurately pointed radiometer, and the Sun's output is measured as a function of time. The instrument is described, its angular response considered, and principles for absolute radiometric measurement presented. Active modes of operation are analyzed, taking into consideration instrumental perturbations and sensor efficiency, heating wire effect, cavity sensor efficiency, thermal effects on the surface of the sensitive area, the effect of the field of view limiting system, and the frequency response of the heat flux detector and absolute radiometric system. Performance of absolute measurements with relatively high accuracy is demonstrated.

  3. Absolute cavity pyrgeometer

    DOEpatents

    Reda, Ibrahim

    2013-10-29

    Implementations of the present disclosure involve an apparatus and method to measure the long-wave irradiance of the atmosphere or long-wave source. The apparatus may involve a thermopile, a concentrator and temperature controller. The incoming long-wave irradiance may be reflected from the concentrator to a thermopile receiver located at the bottom of the concentrator to receive the reflected long-wave irradiance. In addition, the thermopile may be thermally connected to a temperature controller to control the device temperature. Through use of the apparatus, the long-wave irradiance of the atmosphere may be calculated from several measurements provided by the apparatus. In addition, the apparatus may provide an international standard of pyrgeometers' calibration that is traceable back to the International System of Units (SI) rather than to a blackbody atmospheric simulator.

  4. Absolute Radiation Thermometry in the NIR

    NASA Astrophysics Data System (ADS)

    Bünger, L.; Taubert, R. D.; Gutschwager, B.; Anhalt, K.; Briaudeau, S.; Sadli, M.

    2017-04-01

    A near infrared (NIR) radiation thermometer (RT) for temperature measurements in the range from 773 K up to 1235 K was characterized and calibrated in terms of the "Mise en Pratique for the definition of the Kelvin" (MeP-K) by measuring its absolute spectral radiance responsivity. Using Planck's law of thermal radiation allows the direct measurement of the thermodynamic temperature independently of any ITS-90 fixed-point. To determine the absolute spectral radiance responsivity of the radiation thermometer in the NIR spectral region, an existing PTB monochromator-based calibration setup was upgraded with a supercontinuum laser system (0.45 μm to 2.4 μm) resulting in a significantly improved signal-to-noise ratio. The RT was characterized with respect to its nonlinearity, size-of-source effect, distance effect, and the consistency of its individual temperature measuring ranges. To further improve the calibration setup, a new tool for the aperture alignment and distance measurement was developed. Furthermore, the diffraction correction as well as the impedance correction of the current-to-voltage converter is considered. The calibration scheme and the corresponding uncertainty budget of the absolute spectral responsivity are presented. A relative standard uncertainty of 0.1 % (k=1) for the absolute spectral radiance responsivity was achieved. The absolute radiometric calibration was validated at four temperature values with respect to the ITS-90 via a variable temperature heatpipe blackbody (773 K ...1235 K) and at a gold fixed-point blackbody radiator (1337.33 K).

  5. Connecting Coronal Mass Ejections to their Solar Active Region Sources

    NASA Astrophysics Data System (ADS)

    Murray, Sophie; Gallagher, Peter; Carley, Eoin; Zucca, Pietro

    2017-04-01

    Severe space weather events have the potential to significantly impact a range of vital technologies on Earth and in near-Earth space. Understanding the processes involved in the solar eruptions that cause these events is imperative to provide accurate space weather forecasts. Coronal mass ejections (CMEs) and other solar eruptive phenomena can be physically linked by combining data from a multitude of ground-based and space-based instruments as well as models, however this can be challenging for automated operational systems. The EU FP7 HELCATS project provides data from heliospheric imaging onboard the two NASA/STEREO spacecraft in order to track the evolution of CMEs in the inner heliosphere. From a catalogue of nearly 2,000 CME events, an automated algorithm has been developed to connect the CMEs observed by STEREO to any corresponding solar flares and active region sources on the solar surface. CME kinematic properties, such as speed and angular width, are compared with active region magnetic field properties, such as magnetic flux, area, and polarity line characteristics. This large database provides insight into the link between CME and flare events, as well as characteristics of eruptive active regions. The automated method may prove useful for future operational CME forecasting efforts.

  6. Chemoenzymatic approach to optically active 4-hydroxy-5-alkylcyclopent-2-en-1-one derivatives: an application of a combined circular dichroism spectroscopy and DFT calculations to assignment of absolute configuration.

    PubMed

    Frelek, Jadwiga; Karchier, Michał; Madej, Daria; Michalak, Karol; Różański, Paweł; Wicha, Jerzy

    2014-06-01

    A series of representative optically active derivatives of 4-hydroxy-5-alkylcyclopent-2-en-1-one were prepared from the respective 2-furyl methyl carbinols via the Piancatelli rearrangement followed by the enzymatic kinetic resolution of racemates. Applicability of chiroptical methods (experimental and calculated electronic circular dichroism [ECD] and vibrational circular dichroism [VCD] spectra) to determine the absolute configuration of both stereogenic centers in 4-hydroxy-5-methylcyclopent-2-en-1-one was demonstrated. It was also demonstrated that the concurrent application of ECD and VCD spectroscopy can be used for the determination of the configuration of two stereogenic centers. © 2014 Wiley Periodicals, Inc.

  7. Antiglycation Activity of Iridoids and Their Food Sources.

    PubMed

    West, Brett J; Uwaya, Akemi; Isami, Fumiyuki; Deng, Shixin; Nakajima, Sanae; Jensen, C Jarakae

    2014-01-01

    Iridoids are dietary phytochemicals that may have the ability to inhibit the formation of advanced glycation end products (AGEs). Three studies were conducted to investigate this anti-AGE potential. First, the inhibition of fluorescence intensity by food-derived iridoids, after 4 days of incubation with bovine serum albumin, glucose, and fructose, was used to evaluate in vitro antiglycation activity. Next, an 8-week open-label pilot study used the AGE Reader to measure changes in the skin autofluorescence of 34 overweight adults who consumed daily a beverage containing food sources of iridoids. Finally, a cross-sectional population study with 3913 people analyzed the relationship between daily iridoid intake and AGE accumulation, as measured by skin autofluorescence with the TruAge scanner. In the in vitro test, deacetylasperulosidic acid and loganic acid both inhibited glycation in a concentration-dependent manner, with respective IC50 values of 3.55 and 2.69 mM. In the pilot study, average skin autofluorescence measurements decreased by 0.12 units (P < 0.05). The cross-sectional population survey revealed that, for every mg of iridoids consumed, there is a corresponding decline in AGE associated age of 0.017 years (P < 0.0001). These results suggest that consumption of dietary sources of iridoids may be a useful antiaging strategy.

  8. Source localization of brain activity using helium-free interferometer

    NASA Astrophysics Data System (ADS)

    Dammers, Jürgen; Chocholacs, Harald; Eich, Eberhard; Boers, Frank; Faley, Michael; Dunin-Borkowski, Rafal E.; Jon Shah, N.

    2014-05-01

    To detect extremely small magnetic fields generated by the human brain, currently all commercial magnetoencephalography (MEG) systems are equipped with low-temperature (low-Tc) superconducting quantum interference device (SQUID) sensors that use liquid helium for cooling. The limited and increasingly expensive supply of helium, which has seen dramatic price increases recently, has become a real problem for such systems and the situation shows no signs of abating. MEG research in the long run is now endangered. In this study, we report a MEG source localization utilizing a single, highly sensitive SQUID cooled with liquid nitrogen only. Our findings confirm that localization of neuromagnetic activity is indeed possible using high-Tc SQUIDs. We believe that our findings secure the future of this exquisitely sensitive technique and have major implications for brain research and the developments of cost-effective multi-channel, high-Tc SQUID-based MEG systems.

  9. Source localization of brain activity using helium-free interferometer

    SciTech Connect

    Dammers, Jürgen Chocholacs, Harald; Eich, Eberhard; Boers, Frank; Faley, Michael; Dunin-Borkowski, Rafal E.; Jon Shah, N.

    2014-05-26

    To detect extremely small magnetic fields generated by the human brain, currently all commercial magnetoencephalography (MEG) systems are equipped with low-temperature (low-T{sub c}) superconducting quantum interference device (SQUID) sensors that use liquid helium for cooling. The limited and increasingly expensive supply of helium, which has seen dramatic price increases recently, has become a real problem for such systems and the situation shows no signs of abating. MEG research in the long run is now endangered. In this study, we report a MEG source localization utilizing a single, highly sensitive SQUID cooled with liquid nitrogen only. Our findings confirm that localization of neuromagnetic activity is indeed possible using high-T{sub c} SQUIDs. We believe that our findings secure the future of this exquisitely sensitive technique and have major implications for brain research and the developments of cost-effective multi-channel, high-T{sub c} SQUID-based MEG systems.

  10. Cryogenic, Absolute, High Pressure Sensor

    NASA Technical Reports Server (NTRS)

    Chapman, John J. (Inventor); Shams. Qamar A. (Inventor); Powers, William T. (Inventor)

    2001-01-01

    A pressure sensor is provided for cryogenic, high pressure applications. A highly doped silicon piezoresistive pressure sensor is bonded to a silicon substrate in an absolute pressure sensing configuration. The absolute pressure sensor is bonded to an aluminum nitride substrate. Aluminum nitride has appropriate coefficient of thermal expansion for use with highly doped silicon at cryogenic temperatures. A group of sensors, either two sensors on two substrates or four sensors on a single substrate are packaged in a pressure vessel.

  11. Absolute measurement of optical attenuation

    NASA Astrophysics Data System (ADS)

    Wetsel, Grover C., Jr.; Stotts, Steven A.

    1983-06-01

    We have discovered that laser beam deflection spectroscopy can be used for the absolute measurement of wave or particle beam attenuation in condensed matter. The concept has been experimentally evaluated by successfully measuring the absolute optical attenuation in a crystal of U3+:CaF2 at 514 nm. A theoretical model that explains the experiment and characterizes the range of applicability of the method has been developed.

  12. Neutron activation analysis detection limits using {sup 252}Cf sources

    SciTech Connect

    DiPrete, D.P.; Sigg, R.A.

    2000-07-01

    The Savannah River Technology Center (SRTC) developed a neutron activation analysis (NAA) facility several decades ago using low-flux {sup 252}Cf neutron sources. Through this time, the facility has addressed areas of applied interest in managing the Savannah River Site (SRS). Some applications are unique because of the site's operating history and its chemical-processing facilities. Because sensitivity needs for many applications are not severe, they can be accomplished using an {approximately}6-mg {sup 252}Cf NAA facility. The SRTC {sup 252}Cf facility continues to support applied research programs at SRTC as well as other SRS programs for environmental and waste management customers. Samples analyzed by NAA include organic compounds, metal alloys, sediments, site process solutions, and many other materials. Numerous radiochemical analyses also rely on the facility for production of short-lived tracers, yielding by activation of carriers and small-scale isotope production for separation methods testing. These applications are more fully reviewed in Ref. 1. Although the flux [{approximately}2 x 10{sup 7} n/cm{sup 2}{center_dot}s] is low relative to reactor facilities, more than 40 elements can be detected at low and sub-part-per-million levels. Detection limits provided by the facility are adequate for many analytical projects. Other multielement analysis methods, particularly inductively coupled plasma atomic emission and inductively coupled plasma mass spectrometry, can now provide sensitivities on dissolved samples that are often better than those available by NAA using low-flux isotopic sources. Because NAA allows analysis of bulk samples, (a) it is a more cost-effective choice when its sensitivity is adequate than methods that require digestion and (b) it eliminates uncertainties that can be introduced by digestion processes.

  13. Absolute Radiometric Calibration of EUNIS-06

    NASA Technical Reports Server (NTRS)

    Thomas, R. J.; Rabin, D. M.; Kent, B. J.; Paustian, W.

    2007-01-01

    The Extreme-Ultraviolet Normal-Incidence Spectrometer (EUNIS) is a soundingrocket payload that obtains imaged high-resolution spectra of individual solar features, providing information about the Sun's corona and upper transition region. Shortly after its successful initial flight last year, a complete end-to-end calibration was carried out to determine the instrument's absolute radiometric response over its Longwave bandpass of 300 - 370A. The measurements were done at the Rutherford-Appleton Laboratory (RAL) in England, using the same vacuum facility and EUV radiation source used in the pre-flight calibrations of both SOHO/CDS and Hinode/EIS, as well as in three post-flight calibrations of our SERTS sounding rocket payload, the precursor to EUNIS. The unique radiation source provided by the Physikalisch-Technische Bundesanstalt (PTB) had been calibrated to an absolute accuracy of 7% (l-sigma) at 12 wavelengths covering our bandpass directly against the Berlin electron storage ring BESSY, which is itself a primary radiometric source standard. Scans of the EUNIS aperture were made to determine the instrument's absolute spectral sensitivity to +- 25%, considering all sources of error, and demonstrate that EUNIS-06 was the most sensitive solar E W spectrometer yet flown. The results will be matched against prior calibrations which relied on combining measurements of individual optical components, and on comparisons with theoretically predicted 'insensitive' line ratios. Coordinated observations were made during the EUNIS-06 flight by SOHO/CDS and EIT that will allow re-calibrations of those instruments as well. In addition, future EUNIS flights will provide similar calibration updates for TRACE, Hinode/EIS, and STEREO/SECCHI/EUVI.

  14. Tanshinones: Sources, Pharmacokinetics and Anti-Cancer Activities

    PubMed Central

    Zhang, Yong; Jiang, Peixin; Ye, Min; Kim, Sung-Hoon; Jiang, Cheng; Lü, Junxuan

    2012-01-01

    Tanshinones are a class of abietane diterpene compound isolated from Salvia miltiorrhiza (Danshen or Tanshen in Chinese), a well-known herb in Traditional Chinese Medicine (TCM). Since they were first identified in the 1930s, more than 40 lipophilic tanshinones and structurally related compounds have been isolated from Danshen. In recent decades, numerous studies have been conducted to investigate the isolation, identification, synthesis and pharmacology of tanshinones. In addition to the well-studied cardiovascular activities, tanshinones have been investigated more recently for their anti-cancer activities in vitro and in vivo. In this review, we update the herbal and alternative sources of tanshinones, and the pharmacokinetics of selected tanshinones. We discuss anti-cancer properties and identify critical issues for future research. Whereas previous studies have suggested anti-cancer potential of tanshinones affecting multiple cellular processes and molecular targets in cell culture models, data from in vivo potency assessment experiments in preclinical models vary greatly due to lack of uniformity of solvent vehicles and routes of administration. Chemical modifications and novel formulations had been made to address the poor oral bioavailability of tanshinones. So far, human clinical trials have been far from ideal in their design and execution for the purpose of supporting an anti-cancer indication of tanshinones. PMID:23202971

  15. Fruit cuticular waxes as a source of biologically active triterpenoids.

    PubMed

    Szakiel, Anna; Pączkowski, Cezary; Pensec, Flora; Bertsch, Christophe

    2012-06-01

    The health benefits associated with a diet rich in fruit and vegetables include reduction of the risk of chronic diseases such as cardiovascular disease, diabetes and cancer, that are becoming prevalent in the aging human population. Triterpenoids, polycyclic compounds derived from the linear hydrocarbon squalene, are widely distributed in edible and medicinal plants and are an integral part of the human diet. As an important group of phytochemicals that exert numerous biological effects and display various pharmacological activities, triterpenoids are being evaluated for use in new functional foods, drugs, cosmetics and healthcare products. Screening plant material in the search for triterpenoid-rich plant tissues has identified fruit peel and especially fruit cuticular waxes as promising and highly available sources. The chemical composition, abundance and biological activities of triterpenoids occurring in cuticular waxes of some economically important fruits, like apple, grape berry, olive, tomato and others, are described in this review. The need for environmentally valuable and potentially profitable technologies for the recovery, recycling and upgrading of residues from fruit processing is also discussed.

  16. A novel method for the activity measurement of large-area beta reference sources.

    PubMed

    Stanga, D; De Felice, P; Keightley, J; Capogni, M; Ioan, M R

    2016-03-01

    A novel method has been developed for the activity measurement of large-area beta reference sources. It makes use of two emission rate measurements and is based on the weak dependence between the source activity and the activity distribution for a given value of transmission coefficient. The method was checked experimentally by measuring the activity of two ((60)Co and (137)Cs) large-area reference sources constructed from anodized aluminum foils. Measurement results were compared with the activity values measured by gamma spectrometry. For each source, they agree within one standard uncertainty and also agree within the same limits with the certified values of the source activity.

  17. Database applicaton for absolute spectrophotometry

    NASA Astrophysics Data System (ADS)

    Bochkov, Valery V.; Shumko, Sergiy

    2002-12-01

    32-bit database application with multidocument interface for Windows has been developed to calculate absolute energy distributions of observed spectra. The original database contains wavelength calibrated observed spectra which had been already passed through apparatus reductions such as flatfielding, background and apparatus noise subtracting. Absolute energy distributions of observed spectra are defined in unique scale by means of registering them simultaneously with artificial intensity standard. Observations of sequence of spectrophotometric standards are used to define absolute energy of the artificial standard. Observations of spectrophotometric standards are used to define optical extinction in selected moments. FFT algorithm implemented in the application allows performing convolution (deconvolution) spectra with user-defined PSF. The object-oriented interface has been created using facilities of C++ libraries. Client/server model with Windows Socket functionality based on TCP/IP protocol is used to develop the application. It supports Dynamic Data Exchange conversation in server mode and uses Microsoft Exchange communication facilities.

  18. Advanced Light Source activity report 1996/97

    SciTech Connect

    1997-09-01

    Ten years ago, the Advanced Light Source (ALS) existed as a set of drawings, calculations, and ideas. Four years ago, it stored an electron beam for the first time. Today, the ALS has moved from those ideas and beginnings to a robust, third-generation synchrotron user facility, with eighteen beam lines in use, many more in planning or construction phases, and hundreds of users from around the world. Progress from concepts to realities is continuous as the scientific program, already strong in many diverse areas, moves in new directions to meet the needs of researchers into the next century. ALS staff members who develop and maintain the infrastructure for this research are similarly unwilling to rest on their laurels. As a result, the quality of the photon beams the authors deliver, as well as the support they provide to users, continues to improve. The ALS Activity Report is designed to share the results of these efforts in an accessible form for a broad audience. The Scientific Program section, while not comprehensive, shares the breadth, variety, and interest of recent research at the ALS. (The Compendium of User Abstracts and Technical Reports provides a more comprehensive and more technical view.) The Facility Report highlights progress in operations, ongoing accelerator research and development, and beamline instrumentation efforts. Although these Activity Report sections are separate, in practice the achievements of staff and users at the ALS are inseparable. User-staff collaboration is essential as they strive to meet the needs of the user community and to continue the ALS's success as a premier research facility.

  19. Active commuting to school: an overlooked source of childrens' physical activity?

    PubMed

    Tudor-Locke, C; Ainsworth, B E; Popkin, B M

    2001-01-01

    The assessment and promotion of childrens' healthful physical activity is important: (i) to combat the international obesity epidemic that extends to childhood; and (ii) to establish an early habit of lifestyle physical activity that can be sustained into adolescence and adulthood. The primary focus of both assessment and promotion efforts has been on in-school physical education classes and, to a lesser extent, out-of-school structured exercise, sport and play. A potential source of continuous moderate activity, active commuting to school by means of walking or by bicycle, has been largely ignored in surveys of physical activity. Suggestive evidence of steep declines in the amount of childrens' destination walking can be gleaned from national transportation surveys. At the same time, there has been a dramatic increase in the reported use of motorised vehicles, including the use for chauffeuring children. There is very little evidence to support or refute active commuting to school as an important source of childrens' physical activity; however, this is largely because it has been overlooked in the stampede to assess time in more vigorous activities. The promotion of active commuting to school must be considered in the context of parents' real and perceived concerns for their children's personal and pedestrian safety. We certainly do not have a full understanding at this time of all the factors related to decisions about transportation mode, whether by child, parent, community, or school. Such information is necessary if successful and sustainable interventions can be implemented, important transport policy decisions can be made, and community and school designs can be modified. Practice rarely waits for research, however, and there are numerous examples of innovative programming, policies and environmental designs occurring internationally that can serve as natural experiments for enterprising researchers willing to push the envelope of our understanding of active

  20. Absolute classification with unsupervised clustering

    NASA Technical Reports Server (NTRS)

    Jeon, Byeungwoo; Landgrebe, D. A.

    1992-01-01

    An absolute classification algorithm is proposed in which the class definition through training samples or otherwise is required only for a particular class of interest. The absolute classification is considered as a problem of unsupervised clustering when one cluster is known initially. The definitions and statistics of the other classes are automatically developed through the weighted unsupervised clustering procedure, which is developed to keep the cluster corresponding to the class of interest from losing its identity as the class of interest. Once all the classes are developed, a conventional relative classifier such as the maximum-likelihood classifier is used in the classification.

  1. Absolute brightness of fluorescent microspheres.

    PubMed

    Finger, Isaac; Phillips, Scott; Mobley, Elizabeth; Tucker, Robert; Hess, Henry

    2009-02-07

    The absolute brightness of fluorescent particles, such as dye-containing nano- and microspheres or quantum dots, is a critical design parameter for many applications relying on fluorescence detection. The absolute brightness, defined as the ratio of radiant intensity of emission to illumination intensity of excitation, of nile-red fluorescent microspheres with a 1 micrometre diameter is measured to be 4.2 +/- 1 x 10(-16) m(2)/sr, and the implications for the design of kinesin motor protein-powered "smart dust" devices and the remote detection of fluorescence are discussed.

  2. Absolute classification with unsupervised clustering

    NASA Technical Reports Server (NTRS)

    Jeon, Byeungwoo; Landgrebe, D. A.

    1992-01-01

    An absolute classification algorithm is proposed in which the class definition through training samples or otherwise is required only for a particular class of interest. The absolute classification is considered as a problem of unsupervised clustering when one cluster is known initially. The definitions and statistics of the other classes are automatically developed through the weighted unsupervised clustering procedure, which is developed to keep the cluster corresponding to the class of interest from losing its identity as the class of interest. Once all the classes are developed, a conventional relative classifier such as the maximum-likelihood classifier is used in the classification.

  3. Neutron intensity monitor with activation foil for p-Li neutron source for BNCT--Feasibility test of the concept.

    PubMed

    Murata, Isao; Otani, Yuki; Sato, Fuminobu

    2015-12-01

    Proton-lithium (p-Li) reaction is being examined worldwide as a candidate nuclear production reaction for accelerator based neutron source (ABNS) for BNCT. In this reaction, the emitted neutron energy is not so high, below 1 MeV, and especially in backward angles the energy is as low as about 100 keV. The intensity measurement was thus known to be difficult so far. In the present study, a simple method was investigated to monitor the absolute neutron intensity of the p-Li neutron source by employing the foil activation method based on isomer production reactions in order to cover around several hundreds keV. As a result of numerical examination, it was found that (107)Ag, (115)In and (189)Os would be feasible. Their features found out are summarized as follows: (107)Ag: The most convenient foil, since the half life is short. (115)In: The accuracy is the best at 0°, though it cannot be used for backward angles. And (189)Os: Suitable nuclide which can be used in backward angles, though the gamma-ray energy is a little too low. These would be used for p-Li source monitoring depending on measuring purposes in real BNCT scenes.

  4. Absolute transition probabilities of phosphorus.

    NASA Technical Reports Server (NTRS)

    Miller, M. H.; Roig, R. A.; Bengtson, R. D.

    1971-01-01

    Use of a gas-driven shock tube to measure the absolute strengths of 21 P I lines and 126 P II lines (from 3300 to 6900 A). Accuracy for prominent, isolated neutral and ionic lines is estimated to be 28 to 40% and 18 to 30%, respectively. The data and the corresponding theoretical predictions are examined for conformity with the sum rules.-

  5. Absolute transition probabilities of phosphorus.

    NASA Technical Reports Server (NTRS)

    Miller, M. H.; Roig, R. A.; Bengtson, R. D.

    1971-01-01

    Use of a gas-driven shock tube to measure the absolute strengths of 21 P I lines and 126 P II lines (from 3300 to 6900 A). Accuracy for prominent, isolated neutral and ionic lines is estimated to be 28 to 40% and 18 to 30%, respectively. The data and the corresponding theoretical predictions are examined for conformity with the sum rules.-

  6. Absolute Standards for Climate Measurements

    NASA Astrophysics Data System (ADS)

    Leckey, J.

    2016-10-01

    In a world of changing climate, political uncertainty, and ever-changing budgets, the benefit of measurements traceable to SI standards increases by the day. To truly resolve climate change trends on a decadal time scale, on-orbit measurements need to be referenced to something that is both absolute and unchanging. One such mission is the Climate Absolute Radiance and Refractivity Observatory (CLARREO) that will measure a variety of climate variables with an unprecedented accuracy to definitively quantify climate change. In the CLARREO mission, we will utilize phase change cells in which a material is melted to calibrate the temperature of a blackbody that can then be observed by a spectrometer. A material's melting point is an unchanging physical constant that, through a series of transfers, can ultimately calibrate a spectrometer on an absolute scale. CLARREO consists of two primary instruments: an infrared (IR) spectrometer and a reflected solar (RS) spectrometer. The mission will contain orbiting radiometers with sufficient accuracy to calibrate other space-based instrumentation and thus transferring the absolute traceability. The status of various mission options will be presented.

  7. Relativistic Absolutism in Moral Education.

    ERIC Educational Resources Information Center

    Vogt, W. Paul

    1982-01-01

    Discusses Emile Durkheim's "Moral Education: A Study in the Theory and Application of the Sociology of Education," which holds that morally healthy societies may vary in culture and organization but must possess absolute rules of moral behavior. Compares this moral theory with current theory and practice of American educators. (MJL)

  8. Relativistic Absolutism in Moral Education.

    ERIC Educational Resources Information Center

    Vogt, W. Paul

    1982-01-01

    Discusses Emile Durkheim's "Moral Education: A Study in the Theory and Application of the Sociology of Education," which holds that morally healthy societies may vary in culture and organization but must possess absolute rules of moral behavior. Compares this moral theory with current theory and practice of American educators. (MJL)

  9. Specification of High Activity Gamma-Ray Sources.

    ERIC Educational Resources Information Center

    International Commission on Radiation Units and Measurements, Washington, DC.

    The report is concerned with making recommendations for the specifications of gamma ray sources, which relate to the quantity of radioactive material and the radiation emitted. Primary consideration is given to sources in teletherapy and to a lesser extent those used in industrial radiography and in irradiation units used in industry and research.…

  10. Specification of High Activity Gamma-Ray Sources.

    ERIC Educational Resources Information Center

    International Commission on Radiation Units and Measurements, Washington, DC.

    The report is concerned with making recommendations for the specifications of gamma ray sources, which relate to the quantity of radioactive material and the radiation emitted. Primary consideration is given to sources in teletherapy and to a lesser extent those used in industrial radiography and in irradiation units used in industry and research.…

  11. Blind source separation of neural activities from magnetoencephalogram in periodical median nerve stimuli.

    PubMed

    Kishida, Kuinharu

    2013-01-01

    Neural activities of cortices in periodical median nerve stimuli are studied from magnetoencephalogram. The fractional type of the decorrelation method is used for the blind source separation with temporal structure. The blind source separation method is proposed for selecting neural activities related to somatosensory stimulus from magnetoencephalogram by comparing cross-correlation functions between components of blind source separation.

  12. Source-based neurofeedback methods using EEG recordings: training altered brain activity in a functional brain source derived from blind source separation

    PubMed Central

    White, David J.; Congedo, Marco; Ciorciari, Joseph

    2014-01-01

    A developing literature explores the use of neurofeedback in the treatment of a range of clinical conditions, particularly ADHD and epilepsy, whilst neurofeedback also provides an experimental tool for studying the functional significance of endogenous brain activity. A critical component of any neurofeedback method is the underlying physiological signal which forms the basis for the feedback. While the past decade has seen the emergence of fMRI-based protocols training spatially confined BOLD activity, traditional neurofeedback has utilized a small number of electrode sites on the scalp. As scalp EEG at a given electrode site reflects a linear mixture of activity from multiple brain sources and artifacts, efforts to successfully acquire some level of control over the signal may be confounded by these extraneous sources. Further, in the event of successful training, these traditional neurofeedback methods are likely influencing multiple brain regions and processes. The present work describes the use of source-based signal processing methods in EEG neurofeedback. The feasibility and potential utility of such methods were explored in an experiment training increased theta oscillatory activity in a source derived from Blind Source Separation (BSS) of EEG data obtained during completion of a complex cognitive task (spatial navigation). Learned increases in theta activity were observed in two of the four participants to complete 20 sessions of neurofeedback targeting this individually defined functional brain source. Source-based EEG neurofeedback methods using BSS may offer important advantages over traditional neurofeedback, by targeting the desired physiological signal in a more functionally and spatially specific manner. Having provided preliminary evidence of the feasibility of these methods, future work may study a range of clinically and experimentally relevant brain processes where individual brain sources may be targeted by source-based EEG neurofeedback. PMID

  13. Amino acids responsible for the absolute sialidase activity of the influenza A virus neuraminidase: relationship to growth in the duck intestine.

    PubMed

    Kobasa, D; Wells, K; Kawaoka, Y

    2001-12-01

    The 1957 human pandemic strain of influenza A virus contained an avian virus hemagglutinin (HA) and neuraminidase (NA), both of which acquired specificity for the human receptor, N-acetylneuraminic acid linked to galactose of cellular glycoconjugates via an alpha2-6 bond (NeuAcalpha2-6Gal). Although the NA retained considerable specificity for NeuAcalpha2-3Gal, its original substrate in ducks, it lost the ability to support viral growth in the duck intestine, suggesting a growth-restrictive change other than a shift in substrate specificity. To test this possibility, we generated a panel of reassortant viruses that expressed the NA genes of human H2N2 viruses isolated from 1957 to 1968 with all other genes from the avian virus A/duck/Hong Kong/278/78 (H9N2). Only the NA of A/Singapore/1/57 supported efficient viral growth in the intestines of orally inoculated ducks. The growth-supporting capacity of the NA correlated with a high level of enzymatic activity, comparable to that found to be associated with avian virus NAs. The specific activities of the A/Ann Arbor/6/60 and A/England/12/62 NAs, which showed greatly restricted abilities to support viral growth in ducks, were only 8 and 5%, respectively, of the NA specific activity for A/Singapore/1/57. Using chimeric constructs based on A/Singapore/1/57 and A/England/12/62 NAs, we localized the determinants of high specific NA activity to a region containing six amino acid substitutions in A/England/12/62: Ser331-->Arg, Asp339-->Asn, Asn367-->Ser, Ser370-->Leu, Asn400-->Ser, and Pro431-->Glu. Five of these six residues (excluding Asn400) were required and sufficient for the full specific activity of the A/Singapore/1/57 NA. Thus, in addition to a change in substrate specificity, a reduction in high specific activity may be required for the adaptation of avian virus NAs to growth in humans. This change is likely needed to maintain an optimal balance between NA activity and the lower affinity shown by human virus HAs

  14. Proposed neutron activation analysis facilities in the Advanced Neutron Source

    SciTech Connect

    Robinson, L.; Dyer, F.F.; Emery, J.F.

    1990-01-01

    A number of analytical chemistry experimental facilities are being proposed for the Advanced Neutron Source. Experimental capabilities will include gamma-ray analysis and neutron depth profiling. This paper describes the various systems proposed and some of their important characteristics.

  15. Volcanic eruption source parameters from active and passive microwave sensors

    NASA Astrophysics Data System (ADS)

    Montopoli, Mario; Marzano, Frank S.; Cimini, Domenico; Mereu, Luigi

    2016-04-01

    It is well known, in the volcanology community, that precise information of the source parameters characterising an eruption are of predominant interest for the initialization of the Volcanic Transport and Dispersion Models (VTDM). Source parameters of main interest would be the top altitude of the volcanic plume, the flux of the mass ejected at the emission source, which is strictly related to the cloud top altitude, the distribution of volcanic mass concentration along the vertical column as well as the duration of the eruption and the erupted volume. Usually, the combination of a-posteriori field and numerical studies allow constraining the eruption source parameters for a given volcanic event thus making possible the forecast of ash dispersion and deposition from future volcanic eruptions. So far, remote sensors working at visible and infrared channels (cameras and radiometers) have been mainly used to detect, track and provide estimates of the concentration content and the prevailing size of the particles propagating within the ash clouds up to several thousand of kilometres far from the source as well as track back, a-posteriori, the accuracy of the VATDM outputs thus testing the initial choice made for the source parameters. Acoustic wave (infrasound) and microwave fixed scan radar (voldorad) were also used to infer source parameters. In this work we want to put our attention on the role of sensors operating at microwave wavelengths as complementary tools for the real time estimations of source parameters. Microwaves can benefit of the operability during night and day and a relatively negligible sensitivity to the presence of clouds (non precipitating weather clouds) at the cost of a limited coverage and larger spatial resolution when compared with infrared sensors. Thanks to the aforementioned advantages, the products from microwaves sensors are expected to be sensible mostly to the whole path traversed along the tephra cloud making microwaves particularly

  16. Inducing in situ, nonlinear soil response applying an active source

    USGS Publications Warehouse

    Johnson, P.A.; Bodin, P.; Gomberg, J.; Pearce, F.; Lawrence, Z.; Menq, F.-Y.

    2009-01-01

    [1] It is well known that soil sites have a profound effect on ground motion during large earthquakes. The complex structure of soil deposits and the highly nonlinear constitutive behavior of soils largely control nonlinear site response at soil sites. Measurements of nonlinear soil response under natural conditions are critical to advancing our understanding of soil behavior during earthquakes. Many factors limit the use of earthquake observations to estimate nonlinear site response such that quantitative characterization of nonlinear behavior relies almost exclusively on laboratory experiments and modeling of wave propagation. Here we introduce a new method for in situ characterization of the nonlinear behavior of a natural soil formation using measurements obtained immediately adjacent to a large vibrator source. To our knowledge, we are the first group to propose and test such an approach. Employing a large, surface vibrator as a source, we measure the nonlinear behavior of the soil by incrementally increasing the source amplitude over a range of frequencies and monitoring changes in the output spectra. We apply a homodyne algorithm for measuring spectral amplitudes, which provides robust signal-to-noise ratios at the frequencies of interest. Spectral ratios are computed between the receivers and the source as well as receiver pairs located in an array adjacent to the source, providing the means to separate source and near-source nonlinearity from pervasive nonlinearity in the soil column. We find clear evidence of nonlinearity in significant decreases in the frequency of peak spectral ratios, corresponding to material softening with amplitude, observed across the array as the source amplitude is increased. The observed peak shifts are consistent with laboratory measurements of soil nonlinearity. Our results provide constraints for future numerical modeling studies of strong ground motion during earthquakes.

  17. Absolute calibration of sniffer probes on Wendelstein 7-X

    SciTech Connect

    Moseev, D. Laqua, H. P.; Marsen, S.; Stange, T.; Braune, H.; Erckmann, V.; Gellert, F.; Oosterbeek, J. W.

    2016-08-15

    Here we report the first measurements of the power levels of stray radiation in the vacuum vessel of Wendelstein 7-X using absolutely calibrated sniffer probes. The absolute calibration is achieved by using calibrated sources of stray radiation and the implicit measurement of the quality factor of the Wendelstein 7-X empty vacuum vessel. Normalized absolute calibration coefficients agree with the cross-calibration coefficients that are obtained by the direct measurements, indicating that the measured absolute calibration coefficients and stray radiation levels in the vessel are valid. Close to the launcher, the stray radiation in the empty vessel reaches power levels up to 340 kW/m{sup 2} per MW injected beam power. Furthest away from the launcher, i.e., half a toroidal turn, still 90 kW/m{sup 2} per MW injected beam power is measured.

  18. Calorimetric method for determination of {sup 51}Cr neutrino source activity

    SciTech Connect

    Veretenkin, E. P. Gavrin, V. N.; Danshin, S. N.; Ibragimova, T. V.; Kozlova, Yu. P.; Mirmov, I. N.

    2015-12-15

    Experimental study of nonstandard neutrino properties using high-intensity artificial neutrino sources requires the activity of the sources to be determined with high accuracy. In the BEST project, a calorimetric system for measurement of the activity of high-intensity (a few MCi) neutrino sources based on {sup 51}Cr with an accuracy of 0.5–1% is created. In the paper, the main factors affecting the accuracy of determining the neutrino source activity are discussed. The calorimetric system design and the calibration results using a thermal simulator of the source are presented.

  19. Visible Light-Driven Photocatalytic Activity of Oleic Acid-Coated TiO2 Nanoparticles Synthesized from Absolute Ethanol Solution.

    PubMed

    Li, Huihui; Liu, Bin; Yin, Shu; Sato, Tsugio; Wang, Yuhua

    2015-12-01

    The one-step synthesis of oleic acid-coated TiO2 nanoparticles with visible light-driven photocatalytic activity was reported by this manuscript, using oleic acid-ethanol as crucial starting materials. The photocatalytic degradation of nitrogen monoxide (deNOx) in the gas phase was investigated in a continuous reactor using a series of TiO2 semiconductors, prepared from oleic acid- or acetic acid-ethanol solution. The surface modification on TiO2 by organic fatty acid, oleic acid, could reinvest TiO2 photocatalyst with the excellent visible light response. The deNOx ability is almost as high as 30 % destruction in the visible light region (λ > 510 nm) which is similar to the nitrogen-doped TiO2. Meanwhile, acetic acid, a monobasic acid, has a weaker ability on visible light modification of TiO2.

  20. Visible Light-Driven Photocatalytic Activity of Oleic Acid-Coated TiO2 Nanoparticles Synthesized from Absolute Ethanol Solution

    NASA Astrophysics Data System (ADS)

    Li, Huihui; Liu, Bin; Yin, Shu; Sato, Tsugio; Wang, Yuhua

    2015-10-01

    The one-step synthesis of oleic acid-coated TiO2 nanoparticles with visible light-driven photocatalytic activity was reported by this manuscript, using oleic acid-ethanol as crucial starting materials. The photocatalytic degradation of nitrogen monoxide (deNOx) in the gas phase was investigated in a continuous reactor using a series of TiO2 semiconductors, prepared from oleic acid- or acetic acid-ethanol solution. The surface modification on TiO2 by organic fatty acid, oleic acid, could reinvest TiO2 photocatalyst with the excellent visible light response. The deNOx ability is almost as high as 30 % destruction in the visible light region ( λ > 510 nm) which is similar to the nitrogen-doped TiO2. Meanwhile, acetic acid, a monobasic acid, has a weaker ability on visible light modification of TiO2.

  1. Absolute calibration of optical flats

    SciTech Connect

    Sommargren, Gary E.

    2005-04-05

    The invention uses the phase shifting diffraction interferometer (PSDI) to provide a true point-by-point measurement of absolute flatness over the surface of optical flats. Beams exiting the fiber optics in a PSDI have perfect spherical wavefronts. The measurement beam is reflected from the optical flat and passed through an auxiliary optic to then be combined with the reference beam on a CCD. The combined beams include phase errors due to both the optic under test and the auxiliary optic. Standard phase extraction algorithms are used to calculate this combined phase error. The optical flat is then removed from the system and the measurement fiber is moved to recombine the two beams. The newly combined beams include only the phase errors due to the auxiliary optic. When the second phase measurement is subtracted from the first phase measurement, the absolute phase error of the optical flat is obtained.

  2. The Absolute Spectrum Polarimeter (ASP)

    NASA Technical Reports Server (NTRS)

    Kogut, A. J.

    2010-01-01

    The Absolute Spectrum Polarimeter (ASP) is an Explorer-class mission to map the absolute intensity and linear polarization of the cosmic microwave background and diffuse astrophysical foregrounds over the full sky from 30 GHz to 5 THz. The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r much greater than 1O(raised to the power of { -3}) and Compton distortion y < 10 (raised to the power of{-6}). We describe the ASP instrument and mission architecture needed to detect the signature of an inflationary epoch in the early universe using only 4 semiconductor bolometers.

  3. Physics of negative absolute temperatures

    NASA Astrophysics Data System (ADS)

    Abraham, Eitan; Penrose, Oliver

    2017-01-01

    Negative absolute temperatures were introduced into experimental physics by Purcell and Pound, who successfully applied this concept to nuclear spins; nevertheless, the concept has proved controversial: a recent article aroused considerable interest by its claim, based on a classical entropy formula (the "volume entropy") due to Gibbs, that negative temperatures violated basic principles of statistical thermodynamics. Here we give a thermodynamic analysis that confirms the negative-temperature interpretation of the Purcell-Pound experiments. We also examine the principal arguments that have been advanced against the negative temperature concept; we find that these arguments are not logically compelling, and moreover that the underlying "volume" entropy formula leads to predictions inconsistent with existing experimental results on nuclear spins. We conclude that, despite the counterarguments, negative absolute temperatures make good theoretical sense and did occur in the experiments designed to produce them.

  4. Optomechanics for absolute rotation detection

    NASA Astrophysics Data System (ADS)

    Davuluri, Sankar

    2016-07-01

    In this article, we present an application of optomechanical cavity for the absolute rotation detection. The optomechanical cavity is arranged in a Michelson interferometer in such a way that the classical centrifugal force due to rotation changes the length of the optomechanical cavity. The change in the cavity length induces a shift in the frequency of the cavity mode. The phase shift corresponding to the frequency shift in the cavity mode is measured at the interferometer output to estimate the angular velocity of absolute rotation. We derived an analytic expression to estimate the minimum detectable rotation rate in our scheme for a given optomechanical cavity. Temperature dependence of the rotation detection sensitivity is studied.

  5. Information-Driven Active Audio-Visual Source Localization.

    PubMed

    Schult, Niclas; Reineking, Thomas; Kluss, Thorsten; Zetzsche, Christoph

    2015-01-01

    We present a system for sensorimotor audio-visual source localization on a mobile robot. We utilize a particle filter for the combination of audio-visual information and for the temporal integration of consecutive measurements. Although the system only measures the current direction of the source, the position of the source can be estimated because the robot is able to move and can therefore obtain measurements from different directions. These actions by the robot successively reduce uncertainty about the source's position. An information gain mechanism is used for selecting the most informative actions in order to minimize the number of actions required to achieve accurate and precise position estimates in azimuth and distance. We show that this mechanism is an efficient solution to the action selection problem for source localization, and that it is able to produce precise position estimates despite simplified unisensory preprocessing. Because of the robot's mobility, this approach is suitable for use in complex and cluttered environments. We present qualitative and quantitative results of the system's performance and discuss possible areas of application.

  6. Least Absolute Relative Error Estimation.

    PubMed

    Chen, Kani; Guo, Shaojun; Lin, Yuanyuan; Ying, Zhiliang

    2010-01-01

    Multiplicative regression model or accelerated failure time model, which becomes linear regression model after logarithmic transformation, is useful in analyzing data with positive responses, such as stock prices or life times, that are particularly common in economic/financial or biomedical studies. Least squares or least absolute deviation are among the most widely used criterions in statistical estimation for linear regression model. However, in many practical applications, especially in treating, for example, stock price data, the size of relative error, rather than that of error itself, is the central concern of the practitioners. This paper offers an alternative to the traditional estimation methods by considering minimizing the least absolute relative errors for multiplicative regression models. We prove consistency and asymptotic normality and provide an inference approach via random weighting. We also specify the error distribution, with which the proposed least absolute relative errors estimation is efficient. Supportive evidence is shown in simulation studies. Application is illustrated in an analysis of stock returns in Hong Kong Stock Exchange.

  7. Kinetic studies on the oxidation of aryl methyl sulfides and sulfoxides by dimethyldioxirane; absolute rate constants and activation parameters for 4-nitrophenyl methyl sulfide and sulfoxide.

    PubMed

    Hanson, Peter; Hendrickx, Ramon A A J; Lindsay Smith, John R

    2008-02-21

    The oxidations of methyl 4-nitrophenyl sulfide and sulfoxide by dimethyldioxirane, in acetone and mixtures of acetone with water, methanol, acetonitrile and hexane, have been followed by UV-Vis spectroscopy to monitor the decay of the substrates. The data show that, under all the conditions studied, both oxidations obey second-order kinetics. Grunwald-Winstein and Kamlet-Taft analyses of the influence of solvents on the second-order rate constants have been used to obtain mechanistic information on the two reactions. Activation parameters for the two oxidations in acetone and aqueous acetone have been calculated from rate constants for reactions in the temperature range 283-313 K and compared with those from sulfide and sulfoxide oxidations with other oxidants. For sulfoxide oxidations in acetone and 1-20% v/v water in acetone, the results support a concerted nucleophilic displacement by sulfur of oxygen from dimethyldioxirane with the rate being dependent on the solvent's polarity. Sulfide oxidations in acetone and 1-5% v/v water in acetone also proceed by a concerted mechanism. However, in the most polar solvent system studied, 20% v/v water in acetone, the mechanism changes in favour of a two-step reaction involving a betaine intermediate. Importantly, the sulfide oxidation shows a different solvent dependence to that of the sulfoxide, with the rate of oxidation being determined by the hydrogen bond donor capacity and electron-pair donicity of the solvent.

  8. Development of defined microbial population standards using fluorescence activated cell sorting for the absolute quantification of S. aureus using real-time PCR.

    PubMed

    Martinon, Alice; Cronin, Ultan P; Wilkinson, Martin G

    2012-01-01

    In this article, four types of standards were assessed in a SYBR Green-based real-time PCR procedure for the quantification of Staphylococcus aureus (S. aureus) in DNA samples. The standards were purified S. aureus genomic DNA (type A), circular plasmid DNA containing a thermonuclease (nuc) gene fragment (type B), DNA extracted from defined populations of S. aureus cells generated by Fluorescence Activated Cell Sorting (FACS) technology with (type C) or without purification of DNA by boiling (type D). The optimal efficiency of 2.016 was obtained on Roche LightCycler(®) 4.1. software for type C standards, whereas the lowest efficiency (1.682) corresponded to type D standards. Type C standards appeared to be more suitable for quantitative real-time PCR because of the use of defined populations for construction of standard curves. Overall, Fieller Confidence Interval algorithm may be improved for replicates having a low standard deviation in Cycle Threshold values such as found for type B and C standards. Stabilities of diluted PCR standards stored at -20°C were compared after 0, 7, 14 and 30 days and were lower for type A or C standards compared with type B standards. However, FACS generated standards may be useful for bacterial quantification in real-time PCR assays once optimal storage and temperature conditions are defined.

  9. The Canonical DHHC Motif Is Not Absolutely Required for the Activity of the Yeast S-acyltransferases Swf1 and Pfa4*

    PubMed Central

    González Montoro, Ayelén; Chumpen Ramirez, Sabrina; Valdez Taubas, Javier

    2015-01-01

    Protein S-acyltransferases, also known as palmitoyltransferases (PATs), are characterized by the presence of a 50-amino acid domain called the DHHC domain. Within this domain, these four amino acids constitute a highly conserved motif. It has been proposed that the palmitoylation reaction occurs through a palmitoyl-PAT covalent intermediate that involves the conserved cysteine in the DHHC motif. Mutation of this cysteine results in lack of function for several PATs, and DHHA or DHHS mutants are used regularly as catalytically inactive controls. In a genetic screen to isolate loss-of-function mutations in the yeast PAT Swf1, we isolated an allele encoding a Swf1 DHHR mutant. Overexpression of this mutant is able to partially complement a swf1Δ strain and to acylate the Swf1 substrates Tlg1, Syn8, and Snc1. Overexpression of the palmitoyltransferase Pfa4 DHHA or DHHR mutants also results in palmitoylation of its substrate Chs3. We also investigated the role of the first histidine of the DHHC motif. A Swf1 DQHC mutant is also partially active but a DQHR is not. Finally, we show that Swf1 substrates are differentially modified by both DHHR and DQHC Swf1 mutants. We propose that, in the absence of the canonical mechanism, alternative suboptimal mechanisms take place that are more dependent on the reactivity of the acceptor protein. These results also imply that caution must be exercised when proposing non-canonical roles for PATs on the basis of considering DHHC mutants as catalytically inactive and, more generally, contribute to an understanding of the mechanism of protein palmitoylation PMID:26224664

  10. Absolute rate constants for the quenching of reactive excited states by melanin and related 5,6-dihydroxyindole metabolites: implications for their antioxidant activity.

    PubMed

    Zhang, X; Erb, C; Flammer, J; Nau, W M

    2000-05-01

    The triplet-excited state of benzophenone and the singlet-excited state of 2,3-diazabicyclo[2.2.2]oct-2-ene (Fluorazophore-P) have been employed as kinetic probes to obtain information on the antioxidant activity of the skin and eye pigment melanin and its biogenetic precursors 5,6-dihydroxyindole (DHI) and 5,6-dihydroxyindole-2-carboxylic acid (DHICA). The excited states were generated by the laser-flash photolysis technique and their reaction kinetics was examined by time-resolved transient absorption or fluorescence spectroscopy, respectively. The reaction between triplet benzophenone and DHI produced with unit efficiency the corresponding 6O-centered semiquinone radical, which was characterized by its characteristic transient absorption. The quenching rate constants for DHI (3.1-8.4 x 10(9) M-1 s-1) and DHICA (3.3-5.5 x 10(9) M-1 s-1) were near the diffusion-controlled limit, indicating excellent antioxidant properties. Kinetic solvent effects were observed. The reactivity of synthetic melanin, assessed through the quenching rate constant of Fluorazophore-P and normalized to the number of monomer units, was more than one order of magnitude lower (2.7 x 10(8) M-1 s-1) than that of its precursors. The trend of the quenching rate constants, i.e. DHI > DHICA approximately alpha-tocopherol > melanin, along with the preferential solubility of DHICA in aqueous environments, serves to account for several experimental results from biochemical studies on the inhibition of lipid peroxidation by these natural antioxidants.

  11. First Absolutely Calibrated Localized Measurements of Ion Velocity in the MST in Locked and Rotating Plasmas

    NASA Astrophysics Data System (ADS)

    Baltzer, M.; Craig, D.; den Hartog, D. J.; Nornberg, M. D.; Munaretto, S.

    2015-11-01

    An Ion Doppler Spectrometer (IDS) is used on MST for high time-resolution passive and active measurements of impurity ion emission. Absolutely calibrated measurements of flow are difficult because the spectrometer records data within 0.3 nm of the C+5 line of interest, and commercial calibration lamps do not produce lines in this narrow range . A novel optical system was designed to absolutely calibrate the IDS. The device uses an UV LED to produce a broad emission curve in the desired region. A Fabry-Perot etalon filters this light, cutting transmittance peaks into the pattern of the LED emission. An optical train of fused silica lenses focuses the light into the IDS with f/4. A holographic diffuser blurs the light cone to increase homogeneity. Using this light source, the absolute Doppler shift of ion emissions can be measured in MST plasmas. In combination with charge exchange recombination spectroscopy, localized ion velocities can now be measured. Previously, a time-averaged measurement along the chord bisecting the poloidal plane was used to calibrate the IDS; the quality of these central chord calibrations can be characterized with our absolute calibration. Calibration errors may also be quantified and minimized by optimizing the curve-fitting process. Preliminary measurements of toroidal velocity in locked and rotating plasmas will be shown. This work has been supported by the US DOE.

  12. New activity in the Dorado gamma-ray burst source

    SciTech Connect

    Golenetskii, S.V.; Mazets, E.P.; Aptekar, R.L.

    1982-11-01

    On 1981 December 1 and 1982 January 2 the Cone detectors aboard the Venera 13 and Venera 14 probes recorded ..gamma..-ray transients generated by the same source in Dorado as the notable sequence of events observed 1979 March 5, 6 and April 4, 24.

  13. Achieving Climate Change Absolute Accuracy in Orbit

    NASA Technical Reports Server (NTRS)

    Wielicki, Bruce A.; Young, D. F.; Mlynczak, M. G.; Thome, K. J; Leroy, S.; Corliss, J.; Anderson, J. G.; Ao, C. O.; Bantges, R.; Best, F.; hide

    2013-01-01

    The Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission will provide a calibration laboratory in orbit for the purpose of accurately measuring and attributing climate change. CLARREO measurements establish new climate change benchmarks with high absolute radiometric accuracy and high statistical confidence across a wide range of essential climate variables. CLARREO's inherently high absolute accuracy will be verified and traceable on orbit to Système Internationale (SI) units. The benchmarks established by CLARREO will be critical for assessing changes in the Earth system and climate model predictive capabilities for decades into the future as society works to meet the challenge of optimizing strategies for mitigating and adapting to climate change. The CLARREO benchmarks are derived from measurements of the Earth's thermal infrared spectrum (5-50 micron), the spectrum of solar radiation reflected by the Earth and its atmosphere (320-2300 nm), and radio occultation refractivity from which accurate temperature profiles are derived. The mission has the ability to provide new spectral fingerprints of climate change, as well as to provide the first orbiting radiometer with accuracy sufficient to serve as the reference transfer standard for other space sensors, in essence serving as a "NIST [National Institute of Standards and Technology] in orbit." CLARREO will greatly improve the accuracy and relevance of a wide range of space-borne instruments for decadal climate change. Finally, CLARREO has developed new metrics and methods for determining the accuracy requirements of climate observations for a wide range of climate variables and uncertainty sources. These methods should be useful for improving our understanding of observing requirements for most climate change observations.

  14. Achieving Climate Change Absolute Accuracy in Orbit

    NASA Technical Reports Server (NTRS)

    Wielicki, Bruce A.; Young, D. F.; Mlynczak, M. G.; Thome, K. J; Leroy, S.; Corliss, J.; Anderson, J. G.; Ao, C. O.; Bantges, R.; Best, F.; Bowman, K.; Brindley, H.; Butler, J. J.; Collins, W.; Dykema, J. A.; Doelling, D. R.; Feldman, D. R.; Fox, N.; Huang, X.; Holz, R.; Huang, Y.; Jennings, D.; Jin, Z.; Johnson, D. G.; Jucks, K.; Kato, S.; Kratz, D. P.; Liu, X.; Lukashin, C.; Mannucci, A. J.; Phojanamongkolkij, N.; Roithmayr, C. M.; Sandford, S.; Taylor, P. C.; Xiong, X.

    2013-01-01

    The Climate Absolute Radiance and Refractivity Observatory (CLARREO) mission will provide a calibration laboratory in orbit for the purpose of accurately measuring and attributing climate change. CLARREO measurements establish new climate change benchmarks with high absolute radiometric accuracy and high statistical confidence across a wide range of essential climate variables. CLARREO's inherently high absolute accuracy will be verified and traceable on orbit to Système Internationale (SI) units. The benchmarks established by CLARREO will be critical for assessing changes in the Earth system and climate model predictive capabilities for decades into the future as society works to meet the challenge of optimizing strategies for mitigating and adapting to climate change. The CLARREO benchmarks are derived from measurements of the Earth's thermal infrared spectrum (5-50 micron), the spectrum of solar radiation reflected by the Earth and its atmosphere (320-2300 nm), and radio occultation refractivity from which accurate temperature profiles are derived. The mission has the ability to provide new spectral fingerprints of climate change, as well as to provide the first orbiting radiometer with accuracy sufficient to serve as the reference transfer standard for other space sensors, in essence serving as a "NIST [National Institute of Standards and Technology] in orbit." CLARREO will greatly improve the accuracy and relevance of a wide range of space-borne instruments for decadal climate change. Finally, CLARREO has developed new metrics and methods for determining the accuracy requirements of climate observations for a wide range of climate variables and uncertainty sources. These methods should be useful for improving our understanding of observing requirements for most climate change observations.

  15. Issues in Humanoid Audition and Sound Source Localization by Active Audition

    NASA Astrophysics Data System (ADS)

    Nakadai, Kazuhiro; Okuno, Hiroshi G.; Kitano, Hiroaki

    In this paper, we present an active audition system which is implemented on the humanoid robot "SIG the humanoid". The audition system for highly intelligent humanoids localizes sound sources and recognizes auditory events in the auditory scene. Active audition reported in this paper enables SIG to track sources by integrating audition, vision, and motor movements. Given the multiple sound sources in the auditory scene, SIG actively moves its head to improve localization by aligning microphones orthogonal to the sound source and by capturing the possible sound sources by vision. However, such an active head movement inevitably creates motor noises.The system adaptively cancels motor noises using motor control signals and the cover acoustics. The experimental result demonstrates that active audition by integration of audition, vision, and motor control attains sound source tracking in variety of conditions.onditions.

  16. Measurement of Phenotype and Absolute Number of Circulating Heparin-Binding Hemagglutinin, ESAT-6 and CFP-10, and Purified Protein Derivative Antigen-Specific CD4 T Cells Can Discriminate Active from Latent Tuberculosis Infection

    PubMed Central

    Barkham, Timothy M. S.; Tang, Wenying; Kemeny, David M.; Chee, Cynthia Bin-Eng; Wang, Yee T.

    2014-01-01

    The tuberculin skin test (TST) and interferon gamma (IFN-γ) release assays (IGRAs) are used as adjunctive tests for the evaluation of suspected cases of active tuberculosis (TB). However, a positive test does not differentiate latent from active TB. We investigated whether flow cytometric measurement of novel combinations of intracellular cytokines and surface makers on CD4 T cells could differentiate between active and latent TB after stimulation with Mycobacterium tuberculosis-specific proteins. Blood samples from 60 patients referred to the Singapore Tuberculosis Control Unit for evaluation for active TB or as TB contacts were stimulated with purified protein derivative (PPD), ESAT-6 and CFP-10, or heparin-binding hemagglutinin (HBHA). The CD4 T cell cytokine response (IFN-γ, interleukin-2 [IL-2], interleukin-17A [IL-17A], interleukin-22 [IL-22], granulocyte-macrophage colony-stimulating factor [GM-CSF], and tumor necrosis factor alpha [TNF-α]) and surface marker expression (CD27, CXCR3, and CD154) were then measured. We found that the proportion of PPD-specific CD4 T cells, defined as CD154+ TNF-α+ cells that were negative for CD27 and positive for GM-CSF, gave the strongest discrimination between subjects with latent and those with active TB (area under the receiver operator characteristic [ROC] curve of 0.9277; P < 0.0001). Also, the proportions and absolute numbers of HBHA-specific CD4 T cells were significantly higher in those with latent TB infection, particularly CD154+ TNF-α+ IFN-γ+ IL-2+ and CD154+ TNF-α+ CXCR3+. Finally, we found that the ratio of ESAT-6- and CFP-10-responding to HBHA-responding CD4 T cells was significantly different between the two study populations. In conclusion, we found novel markers of M. tuberculosis-specific CD4 cells which differentiate between active and latent TB. PMID:25520147

  17. Caffeine as an indicator of estrogenic activity in source water.

    PubMed

    Montagner, C C; Umbuzeiro, G A; Pasquini, C; Jardim, W F

    2014-08-01

    Caffeine has already been used as an indicator of anthropogenic impacts, especially the ones related to the disposal of sewage in water bodies. In this work, the presence of caffeine has been correlated with the estrogenic activity of water samples measured using the BLYES assay. After testing 96 surface water samples, it was concluded that caffeine can be used to prioritize samples to be tested for estrogenic activity in water quality programs evaluating emerging contaminants with endocrine disruptor activity.

  18. Modulated spectral activity (MSA) - Implications for planetary radio sources

    NASA Technical Reports Server (NTRS)

    Thieman, James R.; Alexander, Joseph K.; Staelin, David H.

    1988-01-01

    The properties of the Jovian and Saturnian MSA, modulation patterns within the normally diffuse nonthermal radio emission that are characterized by distinctive banded structures of enhanced intensity fluctuations in frequency over time scales of minutes to tens of minutes, are discussed. Although Jovian and Saturnian MSA are both normally observed in the 0.2-1.3-MHz frequency range, similar pattern have been noted in Jovian decametric emission above 30 MHz. The MSA properties are used to constrain the possible source mechanism.

  19. Modulated spectral activity (MSA) - Implications for planetary radio sources

    NASA Astrophysics Data System (ADS)

    Thieman, James R.; Alexander, Joseph K.; Staelin, David H.

    The properties of the Jovian and Saturnian MSA, modulation patterns within the normally diffuse nonthermal radio emission that are characterized by distinctive banded structures of enhanced intensity fluctuations in frequency over time scales of minutes to tens of minutes, are discussed. Although Jovian and Saturnian MSA are both normally observed in the 0.2-1.3-MHz frequency range, similar pattern have been noted in Jovian decametric emission above 30 MHz. The MSA properties are used to constrain the possible source mechanism.

  20. Modulated spectral activity (MSA) - Implications for planetary radio sources

    NASA Technical Reports Server (NTRS)

    Thieman, James R.; Alexander, Joseph K.; Staelin, David H.

    1988-01-01

    The properties of the Jovian and Saturnian MSA, modulation patterns within the normally diffuse nonthermal radio emission that are characterized by distinctive banded structures of enhanced intensity fluctuations in frequency over time scales of minutes to tens of minutes, are discussed. Although Jovian and Saturnian MSA are both normally observed in the 0.2-1.3-MHz frequency range, similar pattern have been noted in Jovian decametric emission above 30 MHz. The MSA properties are used to constrain the possible source mechanism.

  1. EPA (Environmental Protection Agency) activities related to sources of ground-water contamination

    SciTech Connect

    Black-Coleman, W.

    1987-02-01

    The report contains a listing of EPA programs and activities, as of October 1986, that address 33 sources of potential ground-water contamination. The information on each activity is presented in a matrix format that is organized by type of contamination source. The following information is presented for each program and activity listed: title, lead office, contact person, type of activity (study, regulation, guidance, strategy, etc.) status, and a summary of the activity. The 33 sources of ground-water contamination are discussed in the 1984 EPA Office of Technology report: Protecting the Nations Ground Water from Contamination.

  2. Artifacts as Sources for Problem-Posing Activities

    ERIC Educational Resources Information Center

    Bonotto, Cinzia

    2013-01-01

    The problem-posing process represents one of the forms of authentic mathematical inquiry which, if suitably implemented in classroom activities, could move well beyond the limitations of word problems, at least as they are typically utilized. The two exploratory studies presented sought to investigate the impact of "problem-posing" activities when…

  3. Simulations as Active Assessment?: Typologizing by Purpose and Source

    ERIC Educational Resources Information Center

    Kollars, Nina A.; Rosen, Amanda M.

    2013-01-01

    Assessment through simulation is something that political science pedagogy has yet to explore in a robust manner. This article advances analysis of social science simulation and assessment by laying out a typology of active-learning activities that isolates and examines their potential for assessment. In short, we argue that there are essentially…

  4. Simulations as Active Assessment?: Typologizing by Purpose and Source

    ERIC Educational Resources Information Center

    Kollars, Nina A.; Rosen, Amanda M.

    2013-01-01

    Assessment through simulation is something that political science pedagogy has yet to explore in a robust manner. This article advances analysis of social science simulation and assessment by laying out a typology of active-learning activities that isolates and examines their potential for assessment. In short, we argue that there are essentially…

  5. Biochemical assays on plasminogen activators and hormones from kidney sources

    NASA Technical Reports Server (NTRS)

    Barlow, Grant H.; Lewis, Marian L.; Morrison, Dennis R.

    1988-01-01

    Investigations were established for the purpose of analyzing the conditioned media from human embryonic kidney cell subpopulations separated in space by electrophoresis. This data is based on the experiments performed on STS-8 on the continuous flow electrophoresis system. The primary biological activity that was analyzed was plasminogen activator activity, but some assays for erythropoeitin and human granulocyte colony stimulating activity were also performed. It is concluded that a battery of assays are required to completely define the plasminogen activator profile of a conditioned media from cell culture. Each type of assay measures different parts of the mixture and are influenced by different parameters. The functional role of each assay is given along with an indication of which combination of assays are required to answer specific questions. With this type of information it is possible by combinations of assays with mathematical analysis to pinpoint a specific component of the system.

  6. Absolute calibration of optical tweezers

    SciTech Connect

    Viana, N.B.; Mazolli, A.; Maia Neto, P.A.; Nussenzveig, H.M.; Rocha, M.S.; Mesquita, O.N.

    2006-03-27

    As a step toward absolute calibration of optical tweezers, a first-principles theory of trapping forces with no adjustable parameters, corrected for spherical aberration, is experimentally tested. Employing two very different setups, we find generally very good agreement for the transverse trap stiffness as a function of microsphere radius for a broad range of radii, including the values employed in practice, and at different sample chamber depths. The domain of validity of the WKB ('geometrical optics') approximation to the theory is verified. Theoretical predictions for the trapping threshold, peak position, depth variation, multiple equilibria, and 'jump' effects are also confirmed.

  7. Linking Aerosol Source Activities to Present and Future Climate Effects

    NASA Astrophysics Data System (ADS)

    Koch, D.; Bond, T. C.; Streets, D.; Menon, S.; Unger, N.

    2007-05-01

    Aerosol source sectors (transport, power, industry, residential, biomass burning) generate distinct mixtures of aerosol species. These mixtures in turn have different effects on climate. As sectoral emissions change in coming decades, whether by regulation or not, it is helpful to link pollution from source types to climate consequences. We do so, using our global (GISS GCM) aerosol model for present and future IPCC SRES scenarios. According to our model, residential and transport sectors have net positive 1995 aerosol forcings (0.04 and 0.03 W m-2) due to their large black carbon contents. However, the sulfate-dominated power and industry sectors have net negative 1995 forcings (-0.10 and -0.09 W m-2). Due to the near-balance of absorbing and scattering components, biomass burning forcing is small. For the 2050 SRES A1B scenario, the net (negative) aerosol forcing is double 1995 due primarily to increased sulfur emissions in the industry and power sectors. For 2050 B1 the net (negative) forcing decreases relative to 1995, as sulfur emissions are reduced. Both future scenarios project decreasing residential emissions. Yet transport emissions are expected to remain significant and thus become the dominant source of warming aerosols in the future. Aerosol pollution is projected to shift southward relative to the present, as the current industrialized regions generally reduce emissions and tropical and southern hemispheric regions continue to develop. Similar to these SRES scenarios, IIASA scenarios project a decline in residential emissions; however IIASA is more optimistic about transport sector emissions reductions. We will conduct present-day climate experiments, including aerosol direct and indirect effects, to study impacts of power and transport sectors on climate features such as air temperature and hydrologic cycle.

  8. How to Detect Amygdala Activity with Magnetoencephalography using Source Imaging

    PubMed Central

    Balderston, Nicholas L.; Schultz, Douglas H.; Baillet, Sylvain; Helmstetter, Fred J.

    2013-01-01

    In trace fear conditioning a conditional stimulus (CS) predicts the occurrence of the unconditional stimulus (UCS), which is presented after a brief stimulus free period (trace interval)1. Because the CS and UCS do not co-occur temporally, the subject must maintain a representation of that CS during the trace interval. In humans, this type of learning requires awareness of the stimulus contingencies in order to bridge the trace interval2-4. However when a face is used as a CS, subjects can implicitly learn to fear the face even in the absence of explicit awareness*. This suggests that there may be additional neural mechanisms capable of maintaining certain types of "biologically-relevant" stimuli during a brief trace interval. Given that the amygdala is involved in trace conditioning, and is sensitive to faces, it is possible that this structure can maintain a representation of a face CS during a brief trace interval. It is challenging to understand how the brain can associate an unperceived face with an aversive outcome, even though the two stimuli are separated in time. Furthermore investigations of this phenomenon are made difficult by two specific challenges. First, it is difficult to manipulate the subject's awareness of the visual stimuli. One common way to manipulate visual awareness is to use backward masking. In backward masking, a target stimulus is briefly presented (< 30 msec) and immediately followed by a presentation of an overlapping masking stimulus5. The presentation of the mask renders the target invisible6-8. Second, masking requires very rapid and precise timing making it difficult to investigate neural responses evoked by masked stimuli using many common approaches. Blood-oxygenation level dependent (BOLD) responses resolve at a timescale too slow for this type of methodology, and real time recording techniques like electroencephalography (EEG) and magnetoencephalography (MEG) have difficulties recovering signal from deep sources. However

  9. How to detect amygdala activity with magnetoencephalography using source imaging.

    PubMed

    Balderston, Nicholas L; Schultz, Douglas H; Baillet, Sylvain; Helmstetter, Fred J

    2013-06-03

    In trace fear conditioning a conditional stimulus (CS) predicts the occurrence of the unconditional stimulus (UCS), which is presented after a brief stimulus free period (trace interval)(1). Because the CS and UCS do not co-occur temporally, the subject must maintain a representation of that CS during the trace interval. In humans, this type of learning requires awareness of the stimulus contingencies in order to bridge the trace interval(2-4). However when a face is used as a CS, subjects can implicitly learn to fear the face even in the absence of explicit awareness*. This suggests that there may be additional neural mechanisms capable of maintaining certain types of "biologically-relevant" stimuli during a brief trace interval. Given that the amygdala is involved in trace conditioning, and is sensitive to faces, it is possible that this structure can maintain a representation of a face CS during a brief trace interval. It is challenging to understand how the brain can associate an unperceived face with an aversive outcome, even though the two stimuli are separated in time. Furthermore investigations of this phenomenon are made difficult by two specific challenges. First, it is difficult to manipulate the subject's awareness of the visual stimuli. One common way to manipulate visual awareness is to use backward masking. In backward masking, a target stimulus is briefly presented (< 30 msec) and immediately followed by a presentation of an overlapping masking stimulus(5). The presentation of the mask renders the target invisible(6-8). Second, masking requires very rapid and precise timing making it difficult to investigate neural responses evoked by masked stimuli using many common approaches. Blood-oxygenation level dependent (BOLD) responses resolve at a timescale too slow for this type of methodology, and real time recording techniques like electroencephalography (EEG) and magnetoencephalography (MEG) have difficulties recovering signal from deep sources

  10. Absolute measurements of fast neutrons using yttrium.

    PubMed

    Roshan, M V; Springham, S V; Rawat, R S; Lee, P; Krishnan, M

    2010-08-01

    Yttrium is presented as an absolute neutron detector for pulsed neutron sources. It has high sensitivity for detecting fast neutrons. Yttrium has the property of generating a monoenergetic secondary radiation in the form of a 909 keV gamma-ray caused by inelastic neutron interaction. It was calibrated numerically using MCNPX and does not need periodic recalibration. The total yttrium efficiency for detecting 2.45 MeV neutrons was determined to be f(n) approximately 4.1x10(-4) with an uncertainty of about 0.27%. The yttrium detector was employed in the NX2 plasma focus experiments and showed the neutron yield of the order of 10(8) neutrons per discharge.

  11. Absolute irradiance of the Moon for on-orbit calibration

    USGS Publications Warehouse

    Stone, T.C.; Kieffer, H.H.; ,

    2002-01-01

    The recognized need for on-orbit calibration of remote sensing imaging instruments drives the ROLO project effort to characterize the Moon for use as an absolute radiance source. For over 5 years the ground-based ROLO telescopes have acquired spatially-resolved lunar images in 23 VNIR (Moon diameter ???500 pixels) and 9 SWIR (???250 pixels) passbands at phase angles within ??90 degrees. A numerical model for lunar irradiance has been developed which fits hundreds of ROLO images in each band, corrected for atmospheric extinction and calibrated to absolute radiance, then integrated to irradiance. The band-coupled extinction algorithm uses absorption spectra of several gases and aerosols derived from MODTRAN to fit time-dependent component abundances to nightly observations of standard stars. The absolute radiance scale is based upon independent telescopic measurements of the star Vega. The fitting process yields uncertainties in lunar relative irradiance over small ranges of phase angle and the full range of lunar libration well under 0.5%. A larger source of uncertainty enters in the absolute solar spectral irradiance, especially in the SWIR, where solar models disagree by up to 6%. Results of ROLO model direct comparisons to spacecraft observations demonstrate the ability of the technique to track sensor responsivity drifts to sub-percent precision. Intercomparisons among instruments provide key insights into both calibration issues and the absolute scale for lunar irradiance.

  12. Why to compare absolute numbers of mitochondria.

    PubMed

    Schmitt, Sabine; Schulz, Sabine; Schropp, Eva-Maria; Eberhagen, Carola; Simmons, Alisha; Beisker, Wolfgang; Aichler, Michaela; Zischka, Hans

    2014-11-01

    Prompted by pronounced structural differences between rat liver and rat hepatocellular carcinoma mitochondria, we suspected these mitochondrial populations to differ massively in their molecular composition. Aiming to reveal these mitochondrial differences, we came across the issue on how to normalize such comparisons and decided to focus on the absolute number of mitochondria. To this end, fluorescently stained mitochondria were quantified by flow cytometry. For rat liver mitochondria, this approach resulted in mitochondrial protein contents comparable to earlier reports using alternative methods. We determined similar protein contents for rat liver, heart and kidney mitochondria. In contrast, however, lower protein contents were determined for rat brain mitochondria and for mitochondria from the rat hepatocellular carcinoma cell line McA 7777. This result challenges mitochondrial comparisons that rely on equal protein amounts as a typical normalization method. Exemplarily, we therefore compared the activity and susceptibility toward inhibition of complex II of rat liver and hepatocellular carcinoma mitochondria and obtained significant discrepancies by either normalizing to protein amount or to absolute mitochondrial number. Importantly, the latter normalization, in contrast to the former, demonstrated a lower complex II activity and higher susceptibility toward inhibition in hepatocellular carcinoma mitochondria compared to liver mitochondria. These findings demonstrate that solely normalizing to protein amount may obscure essential molecular differences between mitochondrial populations. Copyright © 2014 Elsevier B.V. and Mitochondria Research Society. All rights reserved.

  13. Papaya seed represents a rich source of biologically active isothiocyanate.

    PubMed

    Nakamura, Yoshimasa; Yoshimoto, Motoko; Murata, Yoshiyuki; Shimoishi, Yasuaki; Asai, Yumi; Park, Eun Young; Sato, Kenji; Nakamura, Yasushi

    2007-05-30

    In the present study, papaya (Carica papaya) seed and edible pulp were carefully separated and then the contents of benzyl isothiocyanate and the corresponding glucosinolate (benzyl glucosinolate, glucotropaeolin) quantified in each part. The papaya seed with myrosinase inactivation contained >1 mmol of benzyl glucosinolate in 100 g of fresh seed. This content is equivalent to that of Karami daikon (the hottest Japanese white radish) or that of cress. The papaya seed extract also showed a very high activity of myrosinase and, without myrosinase inactivation, produced 460 micromol of benzyl isothiocyanate in 100 g of seed. In contrast, papaya pulp contained an undetectable amount of benzyl glucosinolate and showed no significant myrosinase activity. The n-hexane extract of the papaya seed homogenate was highly effective in inhibiting superoxide generation and apoptosis induction in HL-60 cells, the activities of which are comparable to those of authentic benzyl isothiocyanate.

  14. Geology of the Tremor Source: What are the Active Processes?

    NASA Astrophysics Data System (ADS)

    Fagereng, A.; Hartnady, M. I. H.; Diener, J. F. A.

    2015-12-01

    Tectonic tremor is a low frequency seismic signal lacking impulsive body wave arrivals, but including low and very-low frequency earthquakes. The seismic signal is interpreted to be associated with shear failure at the tremor source, and has been detected on well-instrumented subduction and transform plate boundary interfaces. Tectonic tremor has now been detected at a wide range of depths, but appears to predominantly occur in regions of transitional frictional behavior. To create the low and very-low frequency earthquakes within the tremor signal, frictional failure with a low stress drop is required at the tremor source. A common inference is therefore that tremor involves shear failure at low effective normal stress. Incrementally formed slickenfibre veins are commonly observed in exhumed fault zones. Based on the angle between shear surfaces and tensile veins, slickenfibres can in some locations be shown to have formed incrementally at low effective stress, comparable to tectonic tremor. The veins show slip increments of 10 - 100 micrometers, and along-strike lengths of tens to hundreds of meters, in agreement with values predicted from low frequency earthquake signals. Although slickenfibre veins are a candidate for the geological fingerprint of tectonic tremor, the tremor source occurs over a depth and temperature range that involves several grain scale deformation mechanisms, and both pro- and retrograde metamorphic conditions. The mechanism may therefore be more fundamental, and relate to shear failure in a mixed rheology rock assemblage where ambient stress levels are low. This includes shear failure on weak, frictional discontinuities within bulk viscous rheologies, as can be expected within the frictional transition zones where tremor is observed, independently of metamorphic grade. Slickenfibre veins represent one type of preserved shear discontinuity, on which it is easy to determine past slip increments. We show a number of other examples of

  15. Calibration Of An Active Mammosite Using A Low Activity Sr-90 Radioactive Source

    NASA Astrophysics Data System (ADS)

    Winston, Jacquelyn

    2006-03-01

    The latest involvement of the Brachytherapy research group of the medical physics program at Hampton University is in the development of a scintillator fiber based detector for the breast cancer specific Mammosite (balloon device) from Cytyc Inc. Recent data were acquired at a local hospital to evaluate the possibility of measuring the dose distribution during breast Brachytherapy cancer treatments with this device. Since sub-millimeter accuracy in position is required, precision of the device relies on the accurate calibration of the scintillating fiber element. As part of a collaboration work, data were acquired for that purpose at Hampton University and subsequently analyzed at Morgan State University. An 8 mm diameter strontium-90 radioactive field source with a low activity of 25 μCi was used along with a dedicated LabView data acquisition system. We will discuss the data collected and address some of the features of this novel system.

  16. Calibration Of An Active Mammosite Using A Low Activity Sr-90 Radioactive Source

    NASA Astrophysics Data System (ADS)

    Winston, Jacquelyn

    2007-03-01

    The latest involvement of the Brachytherapy research group of the medical physics program at Hampton University is in the development of a scintillating fiber based detector for the breast cancer specific Mammosite (balloon device) from Cytyc Inc. Recent data were acquired at a local hospital to evaluate the possibility of measuring the dose distribution during breast Brachytherapy cancer treatments with this device. Since sub-millimeter accuracy in position is required, precision of the device relies on the accurate calibration of the scintillating fiber element. As part of a collaboration work, data were acquired for that purpose at Hampton University and subsequently analyzed at Morgan State University. An 8 mm diameter strontium-90 radioactive field source with a low activity of 25 μCi was used along with a dedicated LabView data acquisition system. We will discuss the data collected and address some of the features of this novel system.

  17. Laser ion source activities at Brookhaven National Laboratory

    DOE PAGES

    Kanesue, Takeshi; Okamura, Masahiro

    2015-07-31

    In Brookhaven National Laboratory (BNL), we have been developing laser ion sources for diverse accelerators. Tabletop Nd:YAG lasers with up to several Joules of energy are mainly used to create ablation plasmas for stable operations. The obtained charge states depend on laser power density and target species. Two types of ion extraction schemes, Direct Plasma Injection Scheme (DPIS) and conventional static extraction, are used depending on application. We optimized and select a suitable laser irradiation condition and a beam extraction scheme to meet the requirement of the following accelerator system. We have demonstrated to accelerate more than 5 x 1010more » of C6+ ions using the DPIS. We successfully commissioned low charge ion beam provider to the user facilities in BNL. As a result, to achieve higher current, higher charge state and lower emittance, further studies will continue.« less

  18. Laser ion source activities at Brookhaven National Laboratory

    SciTech Connect

    Kanesue, Takeshi; Okamura, Masahiro

    2015-07-31

    In Brookhaven National Laboratory (BNL), we have been developing laser ion sources for diverse accelerators. Tabletop Nd:YAG lasers with up to several Joules of energy are mainly used to create ablation plasmas for stable operations. The obtained charge states depend on laser power density and target species. Two types of ion extraction schemes, Direct Plasma Injection Scheme (DPIS) and conventional static extraction, are used depending on application. We optimized and select a suitable laser irradiation condition and a beam extraction scheme to meet the requirement of the following accelerator system. We have demonstrated to accelerate more than 5 x 1010 of C6+ ions using the DPIS. We successfully commissioned low charge ion beam provider to the user facilities in BNL. As a result, to achieve higher current, higher charge state and lower emittance, further studies will continue.

  19. Waste tires: A future source of activated carbon?

    SciTech Connect

    1996-01-01

    Millions of used tires are disposed in the United States each year, causing major environmental problems and representing a loss of valuable resources. Currently, over 80% of discarded tires are landfilled (approximately 200 million per year). Because tires disposed in municipal landfills rarely stay buried, regulators, landfill operators, and even the general public are constantly reminded of this problem. These ever-surfacing tires can serve as a breeding ground for disease-causing mosquitoes; in addition, large mounds of tires often catch fire, causing significant air pollution. Recent research indicates that used tires may soon represent a source of carbon-based adsorbents and energy-rich liquid and gaseous hydrocarbons. Details of this research are discussed briefly in this paper. 3 refs., 2 figs.

  20. Absolute, Extreme-Ultraviolet, Solar Spectral Irradiance Monitor (AESSIM)

    NASA Technical Reports Server (NTRS)

    Huber, Martin C. E.; Smith, Peter L.; Parkinson, W. H.; Kuehne, M.; Kock, M.

    1988-01-01

    AESSIM, the Absolute, Extreme-Ultraviolet, Solar Spectral Irradiance Monitor, is designed to measure the absolute solar spectral irradiance at extreme-ultraviolet (EUV) wavelengths. The data are required for studies of the processes that occur in the earth's upper atmosphere and for predictions of atmospheric drag on space vehicles. AESSIM is comprised of sun-pointed spectrometers and newly-developed, secondary standards of spectral irradiance for the EUV. Use of the in-orbit standard sources will eliminate the uncertainties caused by changes in spectrometer efficiency that have plagued all previous measurements of the solar spectral EUV flux.

  1. Quantifying the sources of error in measurements of urine activity

    SciTech Connect

    Mozley, P.D.; Kim, H.J.; McElgin, W.

    1994-05-01

    Accurate scintigraphic measurements of radioactivity in the bladder and voided urine specimens can be limited by scatter, attenuation, and variations in the volume of urine that a given dose is distributed in. The purpose of this study was to quantify some of the errors that these problems can introduce. Transmission scans and 41 conjugate images of the bladder were sequentially acquired on a dual headed camera over 24 hours in 6 subjects after the intravenous administration of 100-150 MBq (2.7-3.6 mCi) of a novel I-123 labeled benzamide. Renal excretion fractions were calculated by measuring the counts in conjugate images of 41 sequentially voided urine samples. A correction for scatter was estimated by comparing the count rates in images that were acquired with the photopeak centered an 159 keV and images that were made simultaneously with the photopeak centered on 126 keV. The decay and attenuation corrected, geometric mean activities were compared to images of the net dose injected. Checks of the results were performed by measuring the total volume of each voided urine specimen and determining the activity in a 20 ml aliquot of it with a dose calibrator. Modeling verified the experimental results which showed that 34% of the counts were attenuated when the bladder had been expanded to a volume of 300 ml. Corrections for attenuation that were based solely on the transmission scans were limited by the volume of non-radioactive urine in the bladder before the activity was administered. The attenuation of activity in images of the voided wine samples was dependent on the geometry of the specimen container. The images of urine in standard, 300 ml laboratory specimen cups had 39{plus_minus}5% fewer counts than images of the same samples laid out in 3 liter bedpans. Scatter through the carbon fiber table substantially increased the number of counts in the images by an average of 14%.

  2. Vertical deformation and absolute gravity

    NASA Astrophysics Data System (ADS)

    Fang, Ming; Hager, Bradford H.

    2001-08-01

    Crustal deformation in the Greenland and Antarctic areas is strongly influenced by both postglacial rebound and contemporary mass redistribution. We explore the relationship between the displacement field and the gravitational disturbance for a viscoelastic Maxwell Earth with an arbitrary radial viscosity profile. We seek to determine whether the effects of viscous relaxation in the memory of surface mass change can be separated from the effects of present day mass variation by combined measurements of vertical displacement and absolute gravity when the viscosity profile in the Earth's interior is unknown. Our conclusion is positive. Specifically, the non-elastic effects can be reduced substantially by combined measurements of displacement and gravity change for a Maxwell viscoelastic Earth regardless of its radial viscosity profile. The underlying physics has nothing to do with the mathematical structure of viscous relaxation modes. Rather, it is due to the fact that the non-elastic response of a Maxwell Earth is nearly incompressible.

  3. Cosmology with negative absolute temperatures

    NASA Astrophysics Data System (ADS)

    Vieira, J. P. P.; Byrnes, Christian T.; Lewis, Antony

    2016-08-01

    Negative absolute temperatures (NAT) are an exotic thermodynamical consequence of quantum physics which has been known since the 1950's (having been achieved in the lab on a number of occasions). Recently, the work of Braun et al. [1] has rekindled interest in negative temperatures and hinted at a possibility of using NAT systems in the lab as dark energy analogues. This paper goes one step further, looking into the cosmological consequences of the existence of a NAT component in the Universe. NAT-dominated expanding Universes experience a borderline phantom expansion (w < -1) with no Big Rip, and their contracting counterparts are forced to bounce after the energy density becomes sufficiently large. Both scenarios might be used to solve horizon and flatness problems analogously to standard inflation and bouncing cosmologies. We discuss the difficulties in obtaining and ending a NAT-dominated epoch, and possible ways of obtaining density perturbations with an acceptable spectrum.

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

    PubMed

    Buch, J L; Ramløv, H

    2016-06-01

    The aim of this study is to provide the reader with a simple setup that can detect antifreeze proteins (AFP) by inhibition of ice recrystallisation in very small sample sizes. This includes an open source cryostage, a method for preparing and loading samples as well as a software analysis method. The entire setup was tested using hyperactive AFP from the cerambycid beetle, Rhagium mordax. Samples containing AFP were compared to buffer samples, and the results are visualised as crystal radius evolution over time and in absolute change over 30 min. Statistical analysis showed that samples containing AFP could reliably be told apart from controls after only two minutes of recrystallisation. The goal of providing a fast, cheap and easy method for detecting antifreeze proteins in solution was met, and further development of the system can be followed at https://github.com/pechano/cryostage. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Neural Sensitivity to Absolute and Relative Anticipated Reward in Adolescents

    PubMed Central

    Vaidya, Jatin G.; Knutson, Brian; O'Leary, Daniel S.; Block, Robert I.; Magnotta, Vincent

    2013-01-01

    Adolescence is associated with a dramatic increase in risky and impulsive behaviors that have been attributed to developmental differences in neural processing of rewards. In the present study, we sought to identify age differences in anticipation of absolute and relative rewards. To do so, we modified a commonly used monetary incentive delay (MID) task in order to examine brain activity to relative anticipated reward value (neural sensitivity to the value of a reward as a function of other available rewards). This design also made it possible to examine developmental differences in brain activation to absolute anticipated reward magnitude (the degree to which neural activity increases with increasing reward magnitude). While undergoing fMRI, 18 adolescents and 18 adult participants were presented with cues associated with different reward magnitudes. After the cue, participants responded to a target to win money on that trial. Presentation of cues was blocked such that two reward cues associated with $.20, $1.00, or $5.00 were in play on a given block. Thus, the relative value of the $1.00 reward varied depending on whether it was paired with a smaller or larger reward. Reflecting age differences in neural responses to relative anticipated reward (i.e., reference dependent processing), adults, but not adolescents, demonstrated greater activity to a $1 reward when it was the larger of the two available rewards. Adults also demonstrated a more linear increase in ventral striatal activity as a function of increasing absolute reward magnitude compared to adolescents. Additionally, reduced ventral striatal sensitivity to absolute anticipated reward (i.e., the difference in activity to medium versus small rewards) correlated with higher levels of trait Impulsivity. Thus, ventral striatal activity in anticipation of absolute and relative rewards develops with age. Absolute reward processing is also linked to individual differences in Impulsivity. PMID:23544046

  6. Absolute calibration of fusion gamma ray detector on TFTR

    NASA Astrophysics Data System (ADS)

    Medley, S. S.; Roquemore, A. L.; Cecil, F. E.

    1992-10-01

    An in situ measurement of the absolute detection efficiency of the fusion gamma ray detector on TFTR has been completed. The efficiency was determined by measuring the yield of the 4.44 MeV gamma ray from a plutonium-berrylium source situated within the vacuum vessel. The absolute detection efficiency at 4.44 MeV is extended to higher energies using the known energy dependence of the gamma ray attenuation coefficients in the vessel port cover, the detector neutron moderator, and the scintillator. The absolute detection efficiency (full energy peak detected gamma rays per source gamma ray) varies from 8.6E-9 at 4.44 MeV to 1.1E-8 at 17 MeV and is insensitive at the few percent level to relatively large variations in the radial profile of the gamma ray source distribution in the plasma. The absolute detection efficiency is used to determine the total d-3He reaction rate during recent deuterium neutral beam heated 3He plasmas on TFTR.

  7. Energy cost and energy sources during a simulated firefighting activity.

    PubMed

    Perroni, Fabrizio; Tessitore, Antonio; Cortis, Cristina; Lupo, Corrado; D'artibale, Emanuele; Cignitti, Lamberto; Capranica, Laura

    2010-12-01

    This study aimed to 1) analyze the energy requirement (VO2eq) and the contribution of the aerobic (VO2ex), anaerobic alactic (VO2al), and anaerobic lactic (VO2la-) energy sources of a simulated intervention; 2) ascertain differences in mean VO2 and heart rate (HR) during firefighting tasks; and 3) verify the relationship between time of job completion and the fitness level of firefighters. Twenty Italian firefighters (age = 32 ± 6 yr, VO2peak = 43.1 ± 4.9 mL·kg·min) performed 4 consecutive tasks (i.e., child rescue; 250-m run; find an exit; 250-m run) that required a VO2eq of 406.26 ± 73.91 mL·kg (VO2ex = 86 ± 5%; VO2al = 9 ± 3%; VO2la- = 5 ± 3%). After 30 minutes, the recovery HR (108 ± 15 beats·min) and VO2 (8.86±2.67mL·kg·min) were higher (p < 0.0001) than basal values (HR = 66 ± 8 beats·min; VO2 = 4.57 ± 1.07 mL·kg·min), indicating that passive recovery is insufficient in reducing the cardiovascular and thermoregulatory strain of the previous workload. Differences (p < 0.001) between tasks emerged for mean VO2 and HR, with a lack of significant correlation between the time of job completion and the firefighters' aerobic fitness. These findings indicate that unpredictable working conditions highly challenge expert firefighters who need adequate fitness levels to meet the requirements of their work. Practically, to enhance the fitness level of firefighters, specific interval training programs should include a wide variety of tasks requiring different intensities and decision-making strategies.

  8. Fundamental principles of absolute radiometry and the philosophy of this NBS program (1968 to 1971)

    NASA Technical Reports Server (NTRS)

    Geist, J.

    1972-01-01

    A description is given work performed on a program to develop an electrically calibrated detector (also called absolute radiometer, absolute detector, and electrically calibrated radiometer) that could be used to realize, maintain, and transfer a scale of total irradiance. The program includes a comprehensive investigation of the theoretical basis of absolute detector radiometry, as well as the design and construction of a number of detectors. A theoretical analysis of the sources of error is also included.

  9. Determination of the absolute photon emission intensities of some gamma rays of (166m)Ho.

    PubMed

    Peyres, Virginia; García-Toraño, Eduardo

    2017-06-24

    This paper presents the results of the absolute measurement of some photon emission intensities in the decay of (166m)Ho. Point sources from a reference solution standardized in the frame of the EURAMET.RI (II)-K2. Ho-166m activity comparison were measured by gamma spectrometry. The detection efficiency was obtained by Monte Carlo calculations including the complete decay scheme. Results obtained for 27 gamma and X-ray emissions are compared to reference values. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Vibration activity and mobility of structure-borne sound sources by a reception plate method.

    PubMed

    Gibbs, B M; Cookson, R; Qi, N

    2008-06-01

    This paper considers a practical structure-borne sound source characterization for mechanical installations, which are connected to plate-like structures. It describes a laboratory-based measurement procedure, which will yield single values of source strength in a form transferable to a prediction of the structure-borne sound power generated in the installed condition. It is confirmed that two source quantities are required, corresponding to the source activity and mobility. For the source activity, a high-mobility reception plate method is proposed which yields a single value in the form of the sum of the squared free velocities, over the contact points. A low-mobility reception plate method also is proposed which, in conjunction with the above, yields the source mobility in the form of the average magnitude of the effective mobility, again over the contact points. Experimental case studies are described and the applicability of the laboratory data for prediction and limitations of the approach are discussed.

  11. Absolute GPS Positioning Using Genetic Algorithms

    NASA Astrophysics Data System (ADS)

    Ramillien, G.

    A new inverse approach for restoring the absolute coordinates of a ground -based station from three or four observed GPS pseudo-ranges is proposed. This stochastic method is based on simulations of natural evolution named genetic algorithms (GA). These iterative procedures provide fairly good and robust estimates of the absolute positions in the Earth's geocentric reference system. For comparison/validation, GA results are compared to the ones obtained using the classical linearized least-square scheme for the determination of the XYZ location proposed by Bancroft (1985) which is strongly limited by the number of available observations (i.e. here, the number of input pseudo-ranges must be four). The r.m.s. accuracy of the non -linear cost function reached by this latter method is typically ~10-4 m2 corresponding to ~300-500-m accuracies for each geocentric coordinate. However, GA can provide more acceptable solutions (r.m.s. errors < 10-5 m2), even when only three instantaneous pseudo-ranges are used, such as a lost of lock during a GPS survey. Tuned GA parameters used in different simulations are N=1000 starting individuals, as well as Pc=60-70% and Pm=30-40% for the crossover probability and mutation rate, respectively. Statistical tests on the ability of GA to recover acceptable coordinates in presence of important levels of noise are made simulating nearly 3000 random samples of erroneous pseudo-ranges. Here, two main sources of measurement errors are considered in the inversion: (1) typical satellite-clock errors and/or 300-metre variance atmospheric delays, and (2) Geometrical Dilution of Precision (GDOP) due to the particular GPS satellite configuration at the time of acquisition. Extracting valuable information and even from low-quality starting range observations, GA offer an interesting alternative for high -precision GPS positioning.

  12. Angular dependence of source-target-detector in active mode standoff infrared detection

    NASA Astrophysics Data System (ADS)

    Pacheco-Londoño, Leonardo C.; Castro-Suarez, John R.; Aparicio-Bolaños, Joaquín. A.; Hernández-Rivera, Samuel P.

    2013-06-01

    Active mode standoff measurement using infrared spectroscopy were carried out in which the angle between target and the source was varied from 0-70° with respect to the surface normal of substrates containing traces of highly energetic materials (explosives). The experiments were made using three infrared sources: a modulated source (Mod-FTIR), an unmodulated source (UnMod-FTIR) and a scanning quantum cascade laser (QCL), part of a dispersive mid infrared (MIR) spectrometer. The targets consisted of PENT 200 μg/cm2 deposited on aluminum plates placed at 1 m from the sources. The evaluation of the three modalities was aimed at verifying the influence of the highly collimated laser beam in the detection in comparison with the other sources. The Mod-FTIR performed better than QCL source in terms of the MIR signal intensity decrease with increasing angle.

  13. Mapping Epileptic Activity: Sources or Networks for the Clinicians?

    PubMed Central

    Pittau, Francesca; Mégevand, Pierre; Sheybani, Laurent; Abela, Eugenio; Grouiller, Frédéric; Spinelli, Laurent; Michel, Christoph M.; Seeck, Margitta; Vulliemoz, Serge

    2014-01-01

    Epileptic seizures of focal origin are classically considered to arise from a focal epileptogenic zone and then spread to other brain regions. This is a key concept for semiological electro-clinical correlations, localization of relevant structural lesions, and selection of patients for epilepsy surgery. Recent development in neuro-imaging and electro-physiology and combinations, thereof, have been validated as contributory tools for focus localization. In parallel, these techniques have revealed that widespread networks of brain regions, rather than a single epileptogenic region, are implicated in focal epileptic activity. Sophisticated multimodal imaging and analysis strategies of brain connectivity patterns have been developed to characterize the spatio-temporal relationships within these networks by combining the strength of both techniques to optimize spatial and temporal resolution with whole-brain coverage and directional connectivity. In this paper, we review the potential clinical contribution of these functional mapping techniques as well as invasive electrophysiology in human beings and animal models for characterizing network connectivity. PMID:25414692

  14. Absolutely separating quantum maps and channels

    NASA Astrophysics Data System (ADS)

    Filippov, S. N.; Magadov, K. Yu; Jivulescu, M. A.

    2017-08-01

    Absolutely separable states ϱ remain separable under arbitrary unitary transformations U\\varrho {U}\\dagger . By example of a three qubit system we show that in a multipartite scenario neither full separability implies bipartite absolute separability nor the reverse statement holds. The main goal of the paper is to analyze quantum maps resulting in absolutely separable output states. Such absolutely separating maps affect the states in a way, when no Hamiltonian dynamics can make them entangled afterwards. We study the general properties of absolutely separating maps and channels with respect to bipartitions and multipartitions and show that absolutely separating maps are not necessarily entanglement breaking. We examine the stability of absolutely separating maps under a tensor product and show that {{{Φ }}}\\otimes N is absolutely separating for any N if and only if Φ is the tracing map. Particular results are obtained for families of local unital multiqubit channels, global generalized Pauli channels, and combination of identity, transposition, and tracing maps acting on states of arbitrary dimension. We also study the interplay between local and global noise components in absolutely separating bipartite depolarizing maps and discuss the input states with high resistance to absolute separability.

  15. A study of outflow activity around EGO sources

    NASA Astrophysics Data System (ADS)

    Farina, C.; Paron, S.; Ortega, M.; Astort, A.; Rubio, M.

    2013-06-01

    Extended green objects (EGOs) were identified in Spitzer-IRAC images as they present a particular extended "green" emission at 4.5 μm, hence their name. An EGO is probably a massive young stellar object driving outflows, with the extended emission at 4.5 μm likely due to H2 lines and CO band-heads excited by the shock of the outflow propagating in the interstellar medium. Therefore, the dedicated observation and study of EGOs and their close environments can provide additional insight into our understanding of massive-star formation processes. In this context, based on previous studies we have selected a set of particularly interesting EGOs with the aim of analysing and characterising their outflow activity and its impact on the interstellar medium around them. This is a work in progress in which new observations at molecular and near-infrared wavelengths have recently been carried out towards some of the selected EGOs and more observations will be done in the following semesters. Here we report the results obtained so far from the data analysis of the images towards EGO, G45.47+0.05 and EGO, G35.04-0.47. For these two targets the molecular line observations were acquired using the Atacama Submillimiter Telescope Experiment (ASTE) and the near-infrared images for EGO, G45.47+0.05 were taken with Gemini-NIRI. The near future plans of this project include new images from WHT-LIRIS for EGO, G035.20-0.74 and EGO, G035.03+0.35.

  16. Activation processes on GaAs photocathode by different currents of oxygen source

    NASA Astrophysics Data System (ADS)

    Miao, Zhuang; Shi, Feng; Cheng, Hongchang; Wang, Shufei; Zhang, Xiaohui; Yuan, Yuan; Chen, Chang

    2015-04-01

    In order to know the influence of activation processes on GaAs photocathodes, three GaAs samples were activated by a fixed current of cesium source and different currents of oxygen source. The current of caesium source is same during activation to ensure initial adsorption of caesium quantum is similar, which is the base to show the difference during alternation activation of caesium and oxygen. Analysed with the activation data, it is indicated that Cs-to-O current ratio of 1.07 is the optimum ratio to obtain higher sensitivity and better stability. According to double dipole model, stable and uniform double dipole layers of GaAs-O-Cs:Cs-O-Cs are formed and negative electron affinity is achieved on GaAs surface by activation with cesium and oxygen. The analytical result is just coincident with the model. Thus there is an efficient technological method to improve sensitivity and stability of GaAs photocathode.

  17. Measurement of Absolute Magnetic Moment

    NASA Astrophysics Data System (ADS)

    Shull, R. D.; Swartzendruber, L. J.

    1998-03-01

    In the past NIST has issued a number of magnetic moment and magnetic susceptibility standards. One of the most popular has been the Ni magnetic moment standard in the form a 2.38 mm diameter sphere of annealed, high-purity nickel, issued in 1978. However, the supply of all the magnetic standards has been exhausted for several years now and the equipment used for their certification no longer exists. Currently, NIST is assembling a precision absolute magnetometer closely resembling the force-based system used earlier by Candela and Mundy (G.A. Candela and R.E. Mundy, Rev. Sci. Instr. 32, 1056 (1959).), but which will have improved accuracy. This magnetometer will be used to certify a new series of magnetic standards, the first of which will be a replacement nickel sphere. A sphere has the advantage that it has uniform magnetization and a known demagnetizing factor, and approximates a point dipole. Nickel has the advantage of saturation at low field, a small temperature dependence at room temperature, and a relatively small field dependence. Other standards with smaller moments and other geometries are also being considered. These, and the current state of the equipment development will be described.

  18. Acceleration of absolute negative mobility.

    PubMed

    Regtmeier, Jan; Grauwin, Sebastian; Eichhorn, Ralf; Reimann, Peter; Anselmetti, Dario; Ros, Alexandra

    2007-07-01

    Recently, the counter intuitive migration phenomenon of absolute negative mobility (ANM) has been demonstrated to occur for colloidal particles in a suitably arranged post array within a microfluidic device [1]. This effect is based on the interplay of Brownian motion, nonlinear dynamics induced through microstructuring, and nonequilibrium driving, and results in a particle movement opposite to an applied static force. Simultaneously, the migration of a different particle species along the direction of the static force is possible [19], thus providing a new tool for particle sorting in microfluidic device format. The so far demonstrated maximum velocities for micrometer-sized spheres are slow, i. e., in the order of 10 nm per second. Here, we investigate numerically, how maximum ANM velocities can be significantly accelerated by a careful adjustment of the post size and shape. Based on this numerical analysis, a post design is developed and tested in a microfluidic device made of PDMS. The experiment reveals an order of magnitude increase in velocity.

  19. Active source cancellation of the blade tone fundamental and harmonics in centrifugal fans

    NASA Astrophysics Data System (ADS)

    Koopmann, G. H.; Fox, D. J.; Neise, W.

    1988-10-01

    An active source method is shown to effectively cancel the blade tone fundamental and harmonics in centrifugal fans for a variety of fan loading conditions and duct terminations. The special case is considered where the frequency of the blade tone harmonics lies just above the cut-on frequency of the first higher order mode of the fan ducting. The results suggest that the present active control mechanism involves a local alteration of the aerodynamic source pressures.

  20. Use of active source geophones for passive source imaging: Examples from Bighorn Arch Seismic Experiment (BASE), USA

    NASA Astrophysics Data System (ADS)

    Sheehan, A.; O'rourke, C. T.; Haines, S. S.; Yang, Z.; Worthington, L. L.; Miller, K. C.

    2013-05-01

    In this paper we explore the variety of active and passive source deep seismic imaging that can be performed using continous wavefield recordings from a dense array of industry-style geophones. The data in this study were acquired during the 2009-10 EarthScope FlexArray Bighorn Arch Seismic Experiment(BASE) in central Wyoming, USA. In addition to traditional active and passive source seismic data acquisition, BASE included a deployment of 850 Reftek RT125 " Texan" dataloggers that produced continuous recording over 14 days. Ground motion was recorded via Geospace GS-11 4.5 Hz single channel vertical component geophones. The geophones were deployed in a grid of three E-W lines and two N-S lines across the Bighorn Mountains. We find that the high frequency geophones effectively record the P waves of teleseismic earthquakes. During the 15 days of continuous recording we observed 57 teleseismic events with pickable P-wave arrivals across the array, providing over 10,000 travel times (P, PKiKP, Pdiff, Pn) suitable for teleseismic tomography. The full waveforms can be used to extract additional information about the subsurface. We have successfully utilized teleseismic receiver-side crustal reverberation phases as virtual sources to mimic crustal reflection profiles (Yang et al., 2012). After depth conversion, we find a coherent phase that correlates well with the top of the Madison Formation under the Powder River and Bighorn Basins that flank the Bighorn Mountains. In addition, we combine the phases PpPdp from single-channel geophone recordings and Ps from three-component recordings to constrain the average Vp /Vs ratio for the sedimentary strata. Following Haines (2011), we are exploring the use of interferometric processing of active source blasts. In principle, virtual source and receiver gathers can be created through cross-correlation of full wavefields. The seismic interferometry provides a means of simulating alternative acquisition geometries, and has the

  1. First absolutely calibrated on-axis ion flow measurements in MST

    NASA Astrophysics Data System (ADS)

    Schott, B.; Baltzer, M.; Craig, D.; den Hartog, D. J.; Nishizawa, T.; Nornberg, M. D.

    2016-10-01

    Improvements in absolute calibration techniques allow for the first direct measurements of the flow profile in the core of MST. We use both active charge exchange recombination spectroscopy and passive emission near 343 nm to measure ion temperature and flow. It is generally assumed that O VI is the brightest passive emission source. However, we show that there are cases, such as high temperature, pulsed poloidal current drive (PPCD) plasmas where the passive emission is dominated by C VI. Differences in the fine structure for O VI and C VI result in a systematic velocity error of about 12 km/s if the wrong model is assumed. Active measurements, however, are relatively insensitive to background model choice. The dominant source of error in active velocity measurements remains the systematic errors in calibration. The first absolutely calibrated, localized toroidal velocity measurements were obtained using an updated calibration technique. During PPCD, the on-axis ion flow is up to 40 km/s larger than both the n = 6 mode velocity and the line-averaged ion velocity. These measurements provide the first direct look at the flow profile in the core of MST. This work has been supported by the US DOE and the Wheaton College summer research program.

  2. HerMES: disentangling active galactic nuclei and star formation in the radio source population

    NASA Astrophysics Data System (ADS)

    Rawlings, J. I.; Page, M. J.; Symeonidis, M.; Bock, J.; Cooray, A.; Farrah, D.; Guo, K.; Hatziminaoglou, E.; Ibar, E.; Oliver, S. J.; Roseboom, I. G.; Scott, Douglas; Seymour, N.; Vaccari, M.; Wardlow, J. L.

    2015-10-01

    We separate the extragalactic radio source population above ˜50 μJy into active galactic nuclei (AGN) and star-forming sources. The primary method of our approach is to fit the infrared spectral energy distributions (SEDs), constructed using Spitzer/IRAC (Infrared Array Camera) and Multiband Imaging Photometer for Spitzer (MIPS) and Herschel/SPIRE photometry, of 380 radio sources in the Extended Chandra Deep Field-South. From the fitted SEDs, we determine the relative AGN and star-forming contributions to their infrared emission. With the inclusion of other AGN diagnostics such as X-ray luminosity, Spitzer/IRAC colours, radio spectral index and the ratio of star-forming total infrared flux to k-corrected 1.4 GHz flux density, qIR, we determine whether the radio emission in these sources is powered by star formation or by an AGN. The majority of these radio sources (60 per cent) show the signature of an AGN at some wavelength. Of the sources with AGN signatures, 58 per cent are hybrid systems for which the radio emission is being powered by star formation. This implies that radio sources which have likely been selected on their star formation have a high AGN fraction. Below a 1.4 GHz flux density of 1 mJy, along with finding a strong contribution to the source counts from pure star-forming sources, we find that hybrid sources constitute 20-65 per cent of the sources. This result suggests that hybrid sources have a significant contribution, along with sources that do not host a detectable AGN, to the observed flattening of the source counts at ˜1 mJy for the extragalactic radio source population.

  3. The fast neutron fluence and the activation detector activity calculations using the effective source method and the adjoint function

    SciTech Connect

    Hep, J.; Konecna, A.; Krysl, V.; Smutny, V.

    2011-07-01

    This paper describes the application of effective source in forward calculations and the adjoint method to the solution of fast neutron fluence and activation detector activities in the reactor pressure vessel (RPV) and RPV cavity of a VVER-440 reactor. Its objective is the demonstration of both methods on a practical task. The effective source method applies the Boltzmann transport operator to time integrated source data in order to obtain neutron fluence and detector activities. By weighting the source data by time dependent decay of the detector activity, the result of the calculation is the detector activity. Alternatively, if the weighting is uniform with respect to time, the result is the fluence. The approach works because of the inherent linearity of radiation transport in non-multiplying time-invariant media. Integrated in this way, the source data are referred to as the effective source. The effective source in the forward calculations method thereby enables the analyst to replace numerous intensive transport calculations with a single transport calculation in which the time dependence and magnitude of the source are correctly represented. In this work, the effective source method has been expanded slightly in the following way: neutron source data were performed with few group method calculation using the active core calculation code MOBY-DICK. The follow-up neutron transport calculation was performed using the neutron transport code TORT to perform multigroup calculations. For comparison, an alternative method of calculation has been used based upon adjoint functions of the Boltzmann transport equation. Calculation of the three-dimensional (3-D) adjoint function for each required computational outcome has been obtained using the deterministic code TORT and the cross section library BGL440. Adjoint functions appropriate to the required fast neutron flux density and neutron reaction rates have been calculated for several significant points within the RPV

  4. Active extragalactic sources - Nearly simultaneous observations from 20 centimeters to 1400 A

    NASA Technical Reports Server (NTRS)

    Landau, R.; Golisch, B.; Jones, T. J.; Jones, T. W.; Pedelty, J.; Rudnick, L.; Sitko, M. L.; Kenney, J.; Roellig, T.; Salonen, E.

    1986-01-01

    IRAS, IUE, and ground-based optical, NIR, mm and submm, and radio observations obtained mainly on Apr. 9-23, 1983, are reported for 19 active extragalactic sources and eight control sources. The overall spectra of the compact active sources are shown to be well represented by continuous-curvature functions such as parabolas. The spectra are found to be consistent with models involving continuous particle injection (with synchrotron losses) or first-order Fermi acceleration (with escape and synchrotron losses), but not with models using relativistic Maxwellian electron distributions.

  5. An Active Global Attack Model for Sensor Source Location Privacy: Analysis and Countermeasures

    NASA Astrophysics Data System (ADS)

    Yang, Yi; Zhu, Sencun; Cao, Guohong; Laporta, Thomas

    Source locations of events are sensitive contextual information that needs to be protected in sensor networks. Previous work focuses on either an active local attacker that traces back to a real source in a hop-by-hop fashion, or a passive global attacker that eavesdrops/analyzes all network traffic to discover real sources. An active global attack model, which is more realistic and powerful than current ones, has not been studied yet. In this paper, we not only formalize this strong attack model, but also propose countermeasures against it.

  6. Active sand dunes are largest dust source in the Sahara Desert

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Atreyee

    2012-09-01

    Dried up lakebeds and playas in the Sahara Desert of North Africa are large sources of dust in the atmosphere. The Bodélé Depression at the southern edge of the Sahara Desert, for example, is the single largest source of dust in the world; on average, 100 dust storms a year originate from the Bodélé Depression. A new study by Crouvi et al., however, finds that active sand dunes could be even bigger sources of desert dust in the atmosphere. Atmospheric dust plays active roles in climate and biological processes in the ocean: It regulates heating at the surface of the Earth; modifies cloud properties that affect rainfall; and acts as the only source of iron, a critical nutrient for microorganisms in the ocean. Little is known about types of dust sources in the Sahara Desert, which alone accounts for more than 50% of the dust in the atmosphere.

  7. EEG and MEG: sensitivity to epileptic spike activity as function of source orientation and depth.

    PubMed

    Hunold, A; Funke, M E; Eichardt, R; Stenroos, M; Haueisen, J

    2016-07-01

    Simultaneous electroencephalography (EEG) and magnetoencephalography (MEG) recordings of neuronal activity from epileptic patients reveal situations in which either EEG or MEG or both modalities show visible interictal spikes. While different signal-to-noise ratios (SNRs) of the spikes in EEG and MEG have been reported, a quantitative relation of spike source orientation and depth as well as the background brain activity to the SNR has not been established. We investigated this quantitative relationship for both dipole and patch sources in an anatomically realistic cortex model. Altogether, 5600 dipole and 3300 patch sources were distributed on the segmented cortical surfaces of two volunteers. The sources were classified according to their quantified depths and orientations, ranging from 20 mm to 60 mm below the skin surface and radial and tangential, respectively. The source time-courses mimicked an interictal spike, and the simulated background activity emulated resting activity. Simulations were conducted with individual three-compartment boundary element models. The SNR was evaluated for 128 EEG, 102 MEG magnetometer, and 204 MEG gradiometer channels. For superficial dipole and superficial patch sources, EEG showed higher SNRs for dominantly radial orientations, and MEG showed higher values for dominantly tangential orientations. Gradiometers provided higher SNR than magnetometers for superficial sources, particularly for those with dominantly tangential orientations. The orientation dependent difference in SNR in EEG and MEG gradually changed as the sources were located deeper, where the interictal spikes generated higher SNRs in EEG compared to those in MEG for all source orientations. With deep sources, the SNRs in gradiometers and magnetometers were of the same order. To better detect spikes, both EEG and MEG should be used.

  8. Agent-based power sharing scheme for active hybrid power sources

    NASA Astrophysics Data System (ADS)

    Jiang, Zhenhua

    The active hybridization technique provides an effective approach to combining the best properties of a heterogeneous set of power sources to achieve higher energy density, power density and fuel efficiency. Active hybrid power sources can be used to power hybrid electric vehicles with selected combinations of internal combustion engines, fuel cells, batteries, and/or supercapacitors. They can be deployed in all-electric ships to build a distributed electric power system. They can also be used in a bulk power system to construct an autonomous distributed energy system. An important aspect in designing an active hybrid power source is to find a suitable control strategy that can manage the active power sharing and take advantage of the inherent scalability and robustness benefits of the hybrid system. This paper presents an agent-based power sharing scheme for active hybrid power sources. To demonstrate the effectiveness of the proposed agent-based power sharing scheme, simulation studies are performed for a hybrid power source that can be used in a solar car as the main propulsion power module. Simulation results clearly indicate that the agent-based control framework is effective to coordinate the various energy sources and manage the power/voltage profiles.

  9. NSLS 2003 ACTIVITY REPORT (NATIONAL SYNCHROTRON LIGHT SOURCE ACTIVITY REPORT 2003)

    SciTech Connect

    MILLER,L.

    2004-05-01

    The scientific productivity of the NSLS continues to be outstanding and the research conducted here has high impact. 2003 was no exception and some of the many highlights from this year's research activity are included in this Activity Report. We are especially pleased that one of our users, Professor Roderick MacKinnon (Rockefeller University), was the co-recipient of the 2003 Nobel Prize in Chemistry for work, much of which was done at the NSLS, explaining how proteins known as ion channels help to generate nerve impulses. It is also a particular pleasure to note that NSLS accelerator physicist Li Hua Yu was awarded the 2003 International Free Electron Laser Prize in recognition of his outstanding achievements, especially demonstrating High Gain Harmonic Generation (HGHG) at the DUV-FEL. Our vision for the NSLS in the next five to 10 years is for it to continue to serve as a vital resource for the nation and especially for the strong Northeast research community. To accomplish this, we are working to preserve and enhance its outstanding scientific productivity by providing increased user support and upgrading beamline and endstation instrumentation. For example, this past year we collaborated with scientists from the Albert Einstein College of Medicine and the BNL Biology Department to develop a new undulator beamline, X29, to meet the needs of macromolecular crystallography for high brightness x-rays. A new endstation on the undulator beamline X13B is being equipped with optics and instrumentation for microdiffraction and microprobe experiments. The wiggler beamline, X21, is being upgraded to provide high intensity and increased capacity for small angle x-ray scattering experiments on nanotemplated soft matter, biomaterials, and other systems. We are collaborating with the BNL Center for Functional Nanomaterials to develop a beamline for LEEM/PEEM studies, which will add important new capabilities for nanoscience and catalysis research. A new high-speed, high

  10. Auditory Selective Attention Reveals Preparatory Activity in Different Cortical Regions for Selection Based on Source Location and Source Pitch

    PubMed Central

    Lee, Adrian K. C.; Rajaram, Siddharth; Xia, Jing; Bharadwaj, Hari; Larson, Eric; Hämäläinen, Matti S.; Shinn-Cunningham, Barbara G.

    2012-01-01

    In order to extract information in a rich environment, we focus on different features that allow us to direct attention to whatever source is of interest. The cortical network deployed during spatial attention, especially in vision, is well characterized. For example, visuospatial attention engages a frontoparietal network including the frontal eye fields (FEFs), which modulate activity in visual sensory areas to enhance the representation of an attended visual object. However, relatively little is known about the neural circuitry controlling attention directed to non-spatial features, or to auditory objects or features (either spatial or non-spatial). Here, using combined magnetoencephalography (MEG) and anatomical information obtained from MRI, we contrasted cortical activity when observers attended to different auditory features given the same acoustic mixture of two simultaneous spoken digits. Leveraging the fine temporal resolution of MEG, we establish that activity in left FEF is enhanced both prior to and throughout the auditory stimulus when listeners direct auditory attention to target location compared to when they focus on target pitch. In contrast, activity in the left posterior superior temporal sulcus (STS), a region previously associated with auditory pitch categorization, is greater when listeners direct attention to target pitch rather than target location. This differential enhancement is only significant after observers are instructed which cue to attend, but before the acoustic stimuli begin. We therefore argue that left FEF participates more strongly in directing auditory spatial attention, while the left STS aids auditory object selection based on the non-spatial acoustic feature of pitch. PMID:23335874

  11. Mixed carbon sources for nitrate reduction in activated sludge-identification of bacteria and process activity studies.

    PubMed

    Hagman, M; Nielsen, J L; Nielsen, P H; Jansen, J la C

    2008-03-01

    Mixtures of methanol and acetate as carbon source were investigated in order to determine their capacity to enhance denitrification and for analysis of the microbial composition and carbon degradation activity in activated sludge from wastewater treatment plants. Laboratory batch reactors at 20 degrees C were used for nitrate uptake rate (NUR) measurements in order to investigate the anoxic activity, while single and mixed carbon substrates were added to activated sludge. Microautoradiography (MAR) in combination with fluorescence in situ hybridisation (FISH) were applied for microbial analysis during exposure to different carbon sources. The NUR increased with additions of a mixture of acetate and methanol compared with additions of a single carbon source. MAR-FISH measurements demonstrated that the probe-defined group of Azoarcus was the main group of bacteria utilising acetate and the only active group utilising methanol under anoxic conditions. The present study indicated an improved denitrification potential by additions of a mixed carbon source compared with commonly used single-carbon additions. It is also established that Azoarcus bacteria are involved in the degradation of both acetate and methanol in the anoxic activated sludge.

  12. Exterior optical cloaking and illusions by using active sources: A boundary element perspective

    NASA Astrophysics Data System (ADS)

    Zheng, H. H.; Xiao, J. J.; Lai, Y.; Chan, C. T.

    2010-05-01

    Recently, it was demonstrated that active sources can be used to cloak any objects that lie outside the cloaking devices [F. Guevara Vasquez, G. W. Milton, and D. Onofrei, Phys. Rev. Lett. 103, 073901 (2009)]. Here, we propose that active sources can create illusion effects so that an object outside the cloaking device can be made to look like another object. Invisibility is a special case in which the concealed object is transformed to a volume of air. From a boundary element perspective, we show that active sources can create a nearly “silent” domain which can conceal any objects inside and at the same time make the whole system look like an illusion of our choice outside a virtual boundary. The boundary element method gives the fields and field gradients, which can be related to monopoles and dipoles, on continuous curves which define the boundary of the active devices. Both the cloaking and illusion effects are confirmed by numerical simulations.

  13. Imaging the magmatic system of Newberry Volcano using Joint active source and teleseismic tomography

    NASA Astrophysics Data System (ADS)

    Heath, Benjamin A.; Hooft, Emilie E. E.; Toomey, Douglas R.; Bezada, Maximiliano J.

    2015-12-01

    In this paper, we combine active and passive source P wave seismic data to tomographically image the magmatic system beneath Newberry Volcano, located east of the Cascade arc. By using both travel times from local active sources and delay times from teleseismic earthquakes recorded on closely spaced seismometers (300-800 m), we significantly improve recovery of upper crustal velocity structure (<10 km depth). The tomographic model reveals a low-velocity feature between 3 and 5 km depth that lies beneath the caldera, consistent with a magma body. In contrast to earlier tomographic studies, where elevated temperatures were sufficient to explain the recovered low velocities, the larger amplitude low-velocity anomalies in our joint tomography model require low degrees of partial melt (˜10%), and a minimum melt volume of ˜2.5 km3. Furthermore, synthetic tests suggest that even greater magnitude low-velocity anomalies, and by inference larger volumes of magma (up to 8 km3), are needed to explain the observed waveform variability. The lateral extent and shape of the inferred magma body indicates that the extensional tectonic regime at Newberry influences the emplacement of magmatic intrusions. Our study shows that jointly inverting active source and passive source seismic data improves tomographic imaging of the shallow crustal seismic structure of volcanic systems and that active source experiments would benefit from longer deployment times to also record teleseismic sources.

  14. Absolute Bunch Length Measurements by Incoherent Radiation Fluctuation Analysis

    SciTech Connect

    Sannibale, F.; Stupakov, G.V.; Zolotorev, M.S.; Filippetto, D.; Jagerhofer, L.; /Vienna, Tech. U.

    2009-12-09

    By analyzing the pulse to pulse intensity fluctuations of the radiation emitted by a charge particle in the incoherent part of the spectrum, it is possible to extract information about the spatial distribution of the beam. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory, we have developed and successfully tested a simple scheme based on this principle that allows for the absolute measurement of the rms bunch length. A description of the method and the experimental results are presented.

  15. Absolute bunch length measurements by incoherent radiation fluctuation analysis

    SciTech Connect

    Sannibale, Fernando; Stupakov, Gennady; Zolotorev, Max; Filippetto, Daniele; Jagerhofer, Lukas

    2008-09-29

    By analyzing the pulse to pulse intensity fluctuations of the radiation emitted by a charge particle in the incoherent part of the spectrum, it is possible to extract information about the spatial distribution of the beam. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory, we have developed and successfully tested a simple scheme based on this principle that allows for the absolute measurement of the rms bunch length. A description of the method and the experimental results are presented.

  16. NSLS 2007 Activity Report (National Synchrotron Light Source Activity Report 2007)

    SciTech Connect

    Miller ,L.; Nasta, K.

    2008-05-01

    The National Synchrotron Light Source is one of the world's most productive and cost-effective user facilities. With 2,219 individual users, about 100 more than last year, and a record-high 985 publications, 2007 was no exception. In addition to producing an impressive array of science highlights, which are included in this Activity Report, many NSLS users were honored this year for their scientific accomplishments. Throughout the year, there were major strides in the development of the scientific programs by strengthening strategic partnerships with major research resources and with the Center for Functional Nanomaterials (CFN). Of particular note, the Consortium for Materials Properties Research in Earth Sciences (COMPRES) received renewed funding for the next five years through the National Science Foundation. COMPRES operates four high-pressure NSLS beamlines--X17B2, X17B3, X17C, and U2A--and serves the earth science community as well as the rapidly expanding segment of researchers using high-pressure techniques in materials, chemical, and energy-related sciences. A joint appointment was made between the NSLS and Stony Brook University to further enhance interactions with COMPRES. There was major progress on two key beamline projects outlined in the Five-Year Strategic Plan: the X25 beamline upgrade and the construction of the X9 small angle scattering (SAXS) beamline. The X25 overhaul, which began with the installation of the in-vacuum mini-gap undulator (MGU) in January 2006, is now complete. X25 is once again the brightest beamline for macromolecular crystallography at the NSLS, and in tandem with the X29 undulator beamline, it will keep the NSLS at the cutting edge in this important area of research. Upgrade work associated with the new MGU and the front end for the X9 SAXS beamline--jointly developed by the NSLS and the CFN--also was completed. Beamline X9 will host the SAXS program that currently exists at beamline X21 and will provide new microbeam SAXS

  17. The PMA Catalogue: 420 million positions and absolute proper motions

    NASA Astrophysics Data System (ADS)

    Akhmetov, V. S.; Fedorov, P. N.; Velichko, A. B.; Shulga, V. M.

    2017-07-01

    We present a catalogue that contains about 420 million absolute proper motions of stars. It was derived from the combination of positions from Gaia DR1 and 2MASS, with a mean difference of epochs of about 15 yr. Most of the systematic zonal errors inherent in the 2MASS Catalogue were eliminated before deriving the absolute proper motions. The absolute calibration procedure (zero-pointing of the proper motions) was carried out using about 1.6 million positions of extragalactic sources. The mean formal error of the absolute calibration is less than 0.35 mas yr-1. The derived proper motions cover the whole celestial sphere without gaps for a range of stellar magnitudes from 8 to 21 mag. In the sky areas where the extragalactic sources are invisible (the avoidance zone), a dedicated procedure was used that transforms the relative proper motions into absolute ones. The rms error of proper motions depends on stellar magnitude and ranges from 2-5 mas yr-1 for stars with 10 mag < G < 17 mag to 5-10 mas yr-1 for faint ones. The present catalogue contains the Gaia DR1 positions of stars for the J2015 epoch. The system of the PMA proper motions does not depend on the systematic errors of the 2MASS positions, and in the range from 14 to 21 mag represents an independent realization of a quasi-inertial reference frame in the optical and near-infrared wavelength range. The Catalogue also contains stellar magnitudes taken from the Gaia DR1 and 2MASS catalogues. A comparison of the PMA proper motions of stars with similar data from certain recent catalogues has been undertaken.

  18. Monolithically integrated absolute frequency comb laser system

    SciTech Connect

    Wanke, Michael C.

    2016-07-12

    Rather than down-convert optical frequencies, a QCL laser system directly generates a THz frequency comb in a compact monolithically integrated chip that can be locked to an absolute frequency without the need of a frequency-comb synthesizer. The monolithic, absolute frequency comb can provide a THz frequency reference and tool for high-resolution broad band spectroscopy.

  19. Estimating the absolute wealth of households.

    PubMed

    Hruschka, Daniel J; Gerkey, Drew; Hadley, Craig

    2015-07-01

    To estimate the absolute wealth of households using data from demographic and health surveys. We developed a new metric, the absolute wealth estimate, based on the rank of each surveyed household according to its material assets and the assumed shape of the distribution of wealth among surveyed households. Using data from 156 demographic and health surveys in 66 countries, we calculated absolute wealth estimates for households. We validated the method by comparing the proportion of households defined as poor using our estimates with published World Bank poverty headcounts. We also compared the accuracy of absolute versus relative wealth estimates for the prediction of anthropometric measures. The median absolute wealth estimates of 1,403,186 households were 2056 international dollars per capita (interquartile range: 723-6103). The proportion of poor households based on absolute wealth estimates were strongly correlated with World Bank estimates of populations living on less than 2.00 United States dollars per capita per day (R(2)  = 0.84). Absolute wealth estimates were better predictors of anthropometric measures than relative wealth indexes. Absolute wealth estimates provide new opportunities for comparative research to assess the effects of economic resources on health and human capital, as well as the long-term health consequences of economic change and inequality.

  20. Estimating the absolute wealth of households

    PubMed Central

    Gerkey, Drew; Hadley, Craig

    2015-01-01

    Abstract Objective To estimate the absolute wealth of households using data from demographic and health surveys. Methods We developed a new metric, the absolute wealth estimate, based on the rank of each surveyed household according to its material assets and the assumed shape of the distribution of wealth among surveyed households. Using data from 156 demographic and health surveys in 66 countries, we calculated absolute wealth estimates for households. We validated the method by comparing the proportion of households defined as poor using our estimates with published World Bank poverty headcounts. We also compared the accuracy of absolute versus relative wealth estimates for the prediction of anthropometric measures. Findings The median absolute wealth estimates of 1 403 186 households were 2056 international dollars per capita (interquartile range: 723–6103). The proportion of poor households based on absolute wealth estimates were strongly correlated with World Bank estimates of populations living on less than 2.00 United States dollars per capita per day (R2 = 0.84). Absolute wealth estimates were better predictors of anthropometric measures than relative wealth indexes. Conclusion Absolute wealth estimates provide new opportunities for comparative research to assess the effects of economic resources on health and human capital, as well as the long-term health consequences of economic change and inequality. PMID:26170506

  1. Absolute optical metrology : nanometers to kilometers

    NASA Technical Reports Server (NTRS)

    Dubovitsky, Serge; Lay, O. P.; Peters, R. D.; Liebe, C. C.

    2005-01-01

    We provide and overview of the developments in the field of high-accuracy absolute optical metrology with emphasis on space-based applications. Specific work on the Modulation Sideband Technology for Absolute Ranging (MSTAR) sensor is described along with novel applications of the sensor.

  2. Introducing the Mean Absolute Deviation "Effect" Size

    ERIC Educational Resources Information Center

    Gorard, Stephen

    2015-01-01

    This paper revisits the use of effect sizes in the analysis of experimental and similar results, and reminds readers of the relative advantages of the mean absolute deviation as a measure of variation, as opposed to the more complex standard deviation. The mean absolute deviation is easier to use and understand, and more tolerant of extreme…

  3. Introducing the Mean Absolute Deviation "Effect" Size

    ERIC Educational Resources Information Center

    Gorard, Stephen

    2015-01-01

    This paper revisits the use of effect sizes in the analysis of experimental and similar results, and reminds readers of the relative advantages of the mean absolute deviation as a measure of variation, as opposed to the more complex standard deviation. The mean absolute deviation is easier to use and understand, and more tolerant of extreme…

  4. Investigating Absolute Value: A Real World Application

    ERIC Educational Resources Information Center

    Kidd, Margaret; Pagni, David

    2009-01-01

    Making connections between various representations is important in mathematics. In this article, the authors discuss the numeric, algebraic, and graphical representations of sums of absolute values of linear functions. The initial explanations are accessible to all students who have experience graphing and who understand that absolute value simply…

  5. ON A SUFFICIENT CONDITION FOR ABSOLUTE CONTINUITY.

    DTIC Science & Technology

    The formulation of a condition which yields absolute continuity when combined with continuity and bounded variation is the problem considered in the...Briefly, the formulation is achieved through a discussion which develops a proof by contradiction of a sufficiently theorem for absolute continuity which uses in its hypothesis the condition of continuity and bounded variation .

  6. Absolute instability of the Gaussian wake profile

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.; Aggarwal, Arun K.

    1987-01-01

    Linear parallel-flow stability theory has been used to investigate the effect of viscosity on the local absolute instability of a family of wake profiles with a Gaussian velocity distribution. The type of local instability, i.e., convective or absolute, is determined by the location of a branch-point singularity with zero group velocity of the complex dispersion relation for the instability waves. The effects of viscosity were found to be weak for values of the wake Reynolds number, based on the center-line velocity defect and the wake half-width, larger than about 400. Absolute instability occurs only for sufficiently large values of the center-line wake defect. The critical value of this parameter increases with decreasing wake Reynolds number, thereby indicating a shrinking region of absolute instability with decreasing wake Reynolds number. If backflow is not allowed, absolute instability does not occur for wake Reynolds numbers smaller than about 38.

  7. Absolute determination of local tropospheric OH concentrations

    NASA Technical Reports Server (NTRS)

    Armerding, Wolfgang; Comes, Franz-Josef

    1994-01-01

    Long path absorption (LPA) according to Lambert Beer's law is a method to determine absolute concentrations of trace gases such as tropospheric OH. We have developed a LPA instrument which is based on a rapid tuning of the light source which is a frequency doubled dye laser. The laser is tuned across two or three OH absorption features around 308 nm with a scanning speed of 0.07 cm(exp -1)/microsecond and a repetition rate of 1.3 kHz. This high scanning speed greatly reduces the fluctuation of the light intensity caused by the atmosphere. To obtain the required high sensitivity the laser output power is additionally made constant and stabilized by an electro-optical modulator. The present sensitivity is of the order of a few times 10(exp 5) OH per cm(exp 3) for an acquisition time of a minute and an absorption path length of only 1200 meters so that a folding of the optical path in a multireflection cell was possible leading to a lateral dimension of the cell of a few meters. This allows local measurements to be made. Tropospheric measurements have been carried out in 1991 resulting in the determination of OH diurnal variation at specific days in late summer. Comparison with model calculations have been made. Interferences are mainly due to SO2 absorption. The problem of OH self generation in the multireflection cell is of minor extent. This could be shown by using different experimental methods. The minimum-maximum signal to noise ratio is about 8 x 10(exp -4) for a single scan. Due to the small size of the absorption cell the realization of an open air laboratory is possible in which by use of an additional UV light source or by additional fluxes of trace gases the chemistry can be changed under controlled conditions allowing kinetic studies of tropospheric photochemistry to be made in open air.

  8. Absolute determination of local tropospheric OH concentrations

    NASA Technical Reports Server (NTRS)

    Armerding, Wolfgang; Comes, Franz-Josef

    1994-01-01

    Long path absorption (LPA) according to Lambert Beer's law is a method to determine absolute concentrations of trace gases such as tropospheric OH. We have developed a LPA instrument which is based on a rapid tuning of the light source which is a frequency doubled dye laser. The laser is tuned across two or three OH absorption features around 308 nm with a scanning speed of 0.07 cm(exp -1)/microsecond and a repetition rate of 1.3 kHz. This high scanning speed greatly reduces the fluctuation of the light intensity caused by the atmosphere. To obtain the required high sensitivity the laser output power is additionally made constant and stabilized by an electro-optical modulator. The present sensitivity is of the order of a few times 10(exp 5) OH per cm(exp 3) for an acquisition time of a minute and an absorption path length of only 1200 meters so that a folding of the optical path in a multireflection cell was possible leading to a lateral dimension of the cell of a few meters. This allows local measurements to be made. Tropospheric measurements have been carried out in 1991 resulting in the determination of OH diurnal variation at specific days in late summer. Comparison with model calculations have been made. Interferences are mainly due to SO2 absorption. The problem of OH self generation in the multireflection cell is of minor extent. This could be shown by using different experimental methods. The minimum-maximum signal to noise ratio is about 8 x 10(exp -4) for a single scan. Due to the small size of the absorption cell the realization of an open air laboratory is possible in which by use of an additional UV light source or by additional fluxes of trace gases the chemistry can be changed under controlled conditions allowing kinetic studies of tropospheric photochemistry to be made in open air.

  9. The VSOP 5 GHz Active Galactic Nucleus Survey. V. Imaging Results for the Remaining 140 Sources

    NASA Astrophysics Data System (ADS)

    Dodson, R.; Fomalont, E. B.; Wiik, K.; Horiuchi, S.; Hirabayashi, H.; Edwards, P. G.; Murata, Y.; Asaki, Y.; Moellenbrock, G. A.; Scott, W. K.; Taylor, A. R.; Gurvits, L. I.; Paragi, Z.; Frey, S.; Shen, Z.-Q.; Lovell, J. E. J.; Tingay, S. J.; Rioja, M. J.; Fodor, S.; Lister, M. L.; Mosoni, L.; Coldwell, G.; Piner, B. G.; Yang, J.

    2008-04-01

    In 1997 February, the Japanese radio astronomy satellite HALCA was launched to provide the space-bourne element for the VLBI Space Observatory Program (VSOP) mission. Approximately 25% of the mission time was dedicated to the VSOP survey of bright compact active galactic nuclei (AGNs) at 5 GHz. This paper, the fifth in the series, presents images and models for the remaining 140 sources not included in the third paper in the series, which contained 102 sources. For most sources, the plots of the (u,v) coverage, the visibility amplitude versus (u,v) distance, and the high-resolution image are presented. Model fit parameters to the major radio components are determined, and the brightness temperature of the core component for each source is calculated. The brightness temperature distributions for all of the sources in the VSOP AGN survey are discussed.

  10. Difficulties in Estimating the Physical Parameters of Compact Radio Sources in Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Artyukh, V. S.

    2016-12-01

    The various factors influencing estimates of the physical parameters of compact radio sources in active galactic nuclei (AGN) using a methods based on uniform models of synchrotron radiation sources are analyzed. It is found that the form of the relativistic electron energy density distribution as a function of magnetic energy density (Ee-EH) in the radio sources is determined by the shape of the electron energy spectrum. It is shown that the very large observed deviations of the estimated energies of the field and relativistic particles from equipartition are mainly caused by nonuniformity of the radio sources. In order to obtain correct estimates of the physical parameters of nonuniform radio sources, it is necessary to know their angular sizes at low frequencies (in the opaque region) and their Doppler factors.

  11. NSLS 2005 ACTIVITY REPORT (NATIONAL SYNCHROTRON LIGHT SOURCE ACTIVITY REPORT 2005).

    SciTech Connect

    MILLER, L.

    2006-05-01

    In 2005, the NSLS proved itself, once again, to be a center of scientific excellence. This remarkable facility, commissioned in the early 1980s, is still attracting some of the world's best researchers in almost every scientific field, who produce more than seven hundred scientific papers every year using the NSLS. The 'Science Highlights' and 'Feature Highlights' sections of this report are just a small sampling of the many, many impressive research projects conducted at the NSLS in 2005. For example, a user group synthesized and studied zinc-oxide nanowires, which have applications in many optical and electrical devices. Another user group studied how strontium and uranium are removed from high-level radioactive waste. And in another interesting study, users deciphered the basis for antibiotic resistance. However, as always, the success of these projects depends on the performance of the facility. Again this year, the rings were in top form--reliability was 96 percent for the x-ray ring and 99 percent for the VUV-IR ring. Additionally, to keep the NSLS as productive as possible and to continue to attract users, many beamline upgrade projects were completed this year. One of the highlights of these upgrades is the new mini-gap undulator installed at beamline X25. This insertion device is providing a much brighter x-ray source for the program at X25. In the always important area of safety, several noteworthy activities took place this year. In particular, NSLS staff made a major commitment to labeling and inspecting electrical equipment. And perhaps the best news is what didn't happen--there were no reportable occurrences related to environmental, safety, or health issues in 2005, and no injuries that resulted in restricted or lost time. We all owe thanks to the dedicated NSLS staff and users who have ensured that the NSLS remains a reliable, safe, up-to-date research facility. As 2005 came to an end, I stepped down as NSLS Chairman in order to focus my primary

  12. Alpha-band activity reflects reduction of mental effort in a comparison task: a source space analysis.

    PubMed

    Keil, Andreas; Mussweiler, Thomas; Epstude, Kai

    2006-11-22

    Comparison processes contribute to many core phenomena of social cognition research. Whenever humans judge a given target, they rely on comparisons with a pertinent standard. We propose that comparison processes may be so ubiquitous because they reduce mental effort. To investigate this possibility, we used dense-array Electroencephalogram (EEG) recordings together with a minimum norm source projection approach. As the dependent variable, we examined changes in parietal alpha (8-12 Hz) amplitude during a judgment task. Spectral changes in the alpha frequency range have been reliably related to attentional load, cognitive arousal, or mental effort. Two groups of participants (n=22) were procedurally primed to solve a series of target judgments in a more comparative (experimental group) versus more absolute (control group) manner. While the participants performed the critical judgment tasks, we recorded changes in alpha amplitude. Continuous EEG was transformed into a spherical source space using the minimum norm (L2) estimate and spectral changes were subsequently calculated in the source domain. Statistical parametric mapping in combination with permutation statistics was employed to map regions showing significant group differences. Results demonstrate that comparative processing was associated with smaller changes in alpha amplitude than absolute processing. This difference was most pronounced at parietal source locations, where alpha reduction was at a maximum. Temporal analysis suggested that this effect was present particularly during task preparation and execution. We conclude that comparative information processing may reduce mental effort in judgment tasks.

  13. Evidence for Infrared-faint Radio Sources as z > 1 Radio-loud Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Huynh, Minh T.; Norris, Ray P.; Siana, Brian; Middelberg, Enno

    2010-02-01

    Infrared-Faint Radio Sources (IFRSs) are a class of radio objects found in the Australia Telescope Large Area Survey which have no observable mid-infrared counterpart in the Spitzer Wide-area Infrared Extragalactic (SWIRE) survey. The extended Chandra Deep Field South now has even deeper Spitzer imaging (3.6-70 μm) from a number of Legacy surveys. We report the detections of two IFRS sources in IRAC images. The non-detection of two other IFRSs allows us to constrain the source type. Detailed modeling of the spectral energy distribution of these objects shows that they are consistent with high-redshift (z >~ 1) active galactic nuclei.

  14. A laser-induced repetitive fast neutron source applied for gold activation analysis

    SciTech Connect

    Lee, Sungman; Park, Sangsoon; Lee, Kitae; Cha, Hyungki

    2012-12-15

    A laser-induced repetitively operated fast neutron source was developed for applications in laser-driven nuclear physics research. The developed neutron source, which has a neutron yield of approximately 4 Multiplication-Sign 10{sup 5} n/pulse and can be operated up to a pulse repetition rate of 10 Hz, was applied for a gold activation analysis. Relatively strong delayed gamma spectra of the activated gold were measured at 333 keV and 355 keV, and proved the possibility of the neutron source for activation analyses. In addition, the nuclear reactions responsible for the measured gamma spectra of gold were elucidated by the 14 MeV fast neutrons resulting from the D(t,n)He{sup 4} nuclear reaction, for which the required tritium originated from the primary fusion reaction, D(d,p)T{sup 3}.

  15. Three-dimensional localization of low activity gamma-ray sources in real-time scenarios

    NASA Astrophysics Data System (ADS)

    Sharma, Manish K.; Alajo, Ayodeji B.; Lee, Hyoung K.

    2016-03-01

    Radioactive source localization plays an important role in tracking radiation threats in homeland security tasks. Its real-time application requires computationally efficient and reasonably accurate algorithms even with limited data to support detection with minimum uncertainty. This paper describes a statistic-based grid-refinement method for backtracing the position of a gamma-ray source in a three-dimensional domain in real-time. The developed algorithm used measurements from various known detector positions to localize the source. This algorithm is based on an inverse-square relationship between source intensity at a detector and the distance from the source to the detector. The domain discretization was developed and implemented in MATLAB. The algorithm was tested and verified from simulation results of an ideal case of a point source in non-attenuating medium. Subsequently, an experimental validation of the algorithm was performed to determine the suitability of deploying this scheme in real-time scenarios. Using the measurements from five known detector positions and for a measurement time of 3 min, the source position was estimated with an accuracy of approximately 53 cm. The accuracy improved and stabilized to approximately 25 cm for higher measurement times. It was concluded that the error in source localization was primarily due to detection uncertainties. In verification and experimental validation of the algorithm, the distance between 137Cs source and any detector position was between 0.84 m and 1.77 m. The results were also compared with the least squares method. Since the discretization algorithm was validated with a weak source, it is expected that it can localize the source of higher activity in real-time. It is believed that for the same physical placement of source and detectors, a source of approximate activity 0.61-0.92 mCi can be localized in real-time with 1 s of measurement time and same accuracy. The accuracy and computational efficiency

  16. Absolute realization of low BRDF value

    NASA Astrophysics Data System (ADS)

    Liu, Zilong; Liao, Ningfang; Li, Ping; Wang, Yu

    2010-10-01

    Low BRDF value is widespread used in many critical domains such as space and military fairs. These values below 0.1 Sr-1 . So the Absolute realization of these value is the most critical issue in the absolute measurement of BRDF. To develop the Absolute value realization theory of BRDF , defining an arithmetic operators of BRDF , achieving an absolute measurement Eq. of BRDF based on radiance. This is a new theory method to solve the realization problem of low BRDF value. This theory method is realized on a self-designed common double orientation structure in space. By designing an adding structure to extend the range of the measurement system and a control and processing software, Absolute realization of low BRDF value is achieved. A material of low BRDF value is measured in this measurement system and the spectral BRDF value are showed within different angles allover the space. All these values are below 0.4 Sr-1 . This process is a representative procedure about the measurement of low BRDF value. A corresponding uncertainty analysis of this measurement data is given depend on the new theory of absolute realization and the performance of the measurement system. The relative expand uncertainty of the measurement data is 0.078. This uncertainty analysis is suitable for all measurements using the new theory of absolute realization and the corresponding measurement system.

  17. Compact sources of suprathermal microwave emission detected in quiescent active regions during lunar occultations

    NASA Astrophysics Data System (ADS)

    Correia, E.; Kaufmann, P.; Strauss, F. M.

    1992-04-01

    Solar quiescent active regions are known to exhibit radio emission from discrete structures. The knowledge of their dimensions and brightness temperatures is essential for understanding the physics of quiescent, confined plasma regions. Solar eclipses of 10 August, 1980 and 26 January, 1990, observed with high sensitivity and high time resolution at 22 GHz, allowed an unprecedented opportunity to identify Fresnel diffraction effects during lunar occultations of active regions. The results indicate the presence of quiescent discrete sources smaller than one arcsec in one dimension. Assuming symmetrical sources, their brightness temperatures were larger than 2 x 10 exp 7 K and 8 x 10 exp 7 K, for the 1980 and 1990 observations, respectively.

  18. Active Control of a Moving Noise SOURCE—EFFECT of Off-Axis Source Position

    NASA Astrophysics Data System (ADS)

    GUO, J.; PAN, J.; HODGSON, M.

    2002-03-01

    An optimally arranged multiple-channel active-control system is known to be able to create a large quiet zone in free space for a stationary primary noise source. When the primary noise source moves, the active control of the noise becomes much more difficult, as the primary noise field changes with time in space. In this case, the controller of the control system must respond fast enough to compensate for the change; much research has been focused on this issue. In this paper, it is shown that a moving source also causes difficulties from an acoustical perspective. A moving source not only changes continuously the strengths and phases of the sound field in the space, but also changes the wavefront of the primary sound field continuously. It is known that the efficiency of active noise control is determined mainly by the wavefront matching between the primary and control fields. To keep the control system effective in the case of a moving source, the wavefront of the control field needs to change, in order to continuously match the primary-wavefront change. This paper shows that there are limitations to the control-wavefront change. An optimally pre-arranged, multiple-channel control system is not able to construct a matching wavefront when the primary source moves outside a certain range. In other words, the control system is still able to create a large quiet zone only when the primary source moves within a range around the central axis of the control system. Both the location and the size of the quiet zone change with the location of the primary source.

  19. Brain activation profiles in dyslexic children during non-word reading: a magnetic source imaging study.

    PubMed

    Simos, P G; Breier, J I; Fletcher, J M; Foorman, B R; Bergman, E; Fishbeck, K; Papanicolaou, A C

    2000-08-18

    The purpose of the study was to identify spatiotemporal brain activation profiles associated with phonological decoding in dyslexic children using magnetic source imaging. For this purpose maps of regional cerebral activation were obtained from eleven children diagnosed with dyslexia and ten children without reading problems during engagement in a pseudoword rhyme-matching task. All dyslexic children showed aberrant activation maps consisting of reduced activity in temporoparietal areas in the left hemisphere (including the posterior part of the superior temporal, angular and supramarginal gyri) and increased activity in the right homotopic region. In contrast, the two groups of children did not differ in the degree of activity in basal temporal areas that typically precedes temporoparietal activation. This is the first study to demonstrate the existence of distinct activation profiles associated with phonological decoding in individual dyslexic children.

  20. Comparison of the trapping effect and antioxidant enzymatic activities using three different light sources in cockchafers.

    PubMed

    Gao, Yan; Li, Ganghua; Li, Kebin; Lei, Chaoliang; Huang, Qiuying

    2017-10-07

    Light traps have been widely used for controlling underground pests. However, very little is known regarding the relationship between trapping effect and antioxidant enzymatic activities using light irradiation in underground pests. Thus, we determined the trapping effect of three light sources of the frequoscillation pest-killing lamp on two species of cockchafers, Serica orientalis Motschulsky (Coleoptera: Melolonthidae) and Anomala corpulenta Motschulsky (Coleoptera: Rutelidae), and evaluated the effect of the same three light sources on the activities of their antioxidant enzymes. The catches of S. orientalis were significantly higher compared to A. corpulenta using light source A in peanut fields in China. After irradiation by light source A, the malondialdehyde (MDA) contents and activities of superoxide dismutase (SOD) and glutathione S-transferases (GST) in S. orientalis were significantly and marginally significantly lower compared to A. corpulenta. Taken together, these results indicated a weaker antioxidant enzyme activity response to light stress and a larger quantity of trapping catches using light irradiation in cockchafers. Thus, we proposed a potential negative relationship between trapping effect and antioxidant enzymatic activities in response to light irradiation in cockchafers.

  1. MEG source localization of spatially extended generators of epileptic activity: comparing entropic and hierarchical bayesian approaches.

    PubMed

    Chowdhury, Rasheda Arman; Lina, Jean Marc; Kobayashi, Eliane; Grova, Christophe

    2013-01-01

    Localizing the generators of epileptic activity in the brain using Electro-EncephaloGraphy (EEG) or Magneto-EncephaloGraphy (MEG) signals is of particular interest during the pre-surgical investigation of epilepsy. Epileptic discharges can be detectable from background brain activity, provided they are associated with spatially extended generators. Using realistic simulations of epileptic activity, this study evaluates the ability of distributed source localization methods to accurately estimate the location of the generators and their sensitivity to the spatial extent of such generators when using MEG data. Source localization methods based on two types of realistic models have been investigated: (i) brain activity may be modeled using cortical parcels and (ii) brain activity is assumed to be locally smooth within each parcel. A Data Driven Parcellization (DDP) method was used to segment the cortical surface into non-overlapping parcels and diffusion-based spatial priors were used to model local spatial smoothness within parcels. These models were implemented within the Maximum Entropy on the Mean (MEM) and the Hierarchical Bayesian (HB) source localization frameworks. We proposed new methods in this context and compared them with other standard ones using Monte Carlo simulations of realistic MEG data involving sources of several spatial extents and depths. Detection accuracy of each method was quantified using Receiver Operating Characteristic (ROC) analysis and localization error metrics. Our results showed that methods implemented within the MEM framework were sensitive to all spatial extents of the sources ranging from 3 cm(2) to 30 cm(2), whatever were the number and size of the parcels defining the model. To reach a similar level of accuracy within the HB framework, a model using parcels larger than the size of the sources should be considered.

  2. MEG Source Localization of Spatially Extended Generators of Epileptic Activity: Comparing Entropic and Hierarchical Bayesian Approaches

    PubMed Central

    Chowdhury, Rasheda Arman; Lina, Jean Marc; Kobayashi, Eliane; Grova, Christophe

    2013-01-01

    Localizing the generators of epileptic activity in the brain using Electro-EncephaloGraphy (EEG) or Magneto-EncephaloGraphy (MEG) signals is of particular interest during the pre-surgical investigation of epilepsy. Epileptic discharges can be detectable from background brain activity, provided they are associated with spatially extended generators. Using realistic simulations of epileptic activity, this study evaluates the ability of distributed source localization methods to accurately estimate the location of the generators and their sensitivity to the spatial extent of such generators when using MEG data. Source localization methods based on two types of realistic models have been investigated: (i) brain activity may be modeled using cortical parcels and (ii) brain activity is assumed to be locally smooth within each parcel. A Data Driven Parcellization (DDP) method was used to segment the cortical surface into non-overlapping parcels and diffusion-based spatial priors were used to model local spatial smoothness within parcels. These models were implemented within the Maximum Entropy on the Mean (MEM) and the Hierarchical Bayesian (HB) source localization frameworks. We proposed new methods in this context and compared them with other standard ones using Monte Carlo simulations of realistic MEG data involving sources of several spatial extents and depths. Detection accuracy of each method was quantified using Receiver Operating Characteristic (ROC) analysis and localization error metrics. Our results showed that methods implemented within the MEM framework were sensitive to all spatial extents of the sources ranging from 3 cm2 to 30 cm2, whatever were the number and size of the parcels defining the model. To reach a similar level of accuracy within the HB framework, a model using parcels larger than the size of the sources should be considered. PMID:23418485

  3. Complex active regions as the main source of extreme and large solar proton events

    NASA Astrophysics Data System (ADS)

    Ishkov, V. N.

    2013-12-01

    A study of solar proton sources indicated that solar flare events responsible for ≥2000 pfu proton fluxes mostly occur in complex active regions (CARs), i.e., in transition structures between active regions and activity complexes. Different classes of similar structures and their relation to solar proton events (SPEs) and evolution, depending on the origination conditions, are considered. Arguments in favor of the fact that sunspot groups with extreme dimensions are CARs are presented. An analysis of the flare activity in a CAR resulted in the detection of "physical" boundaries, which separate magnetic structures of the same polarity and are responsible for the independent development of each structure.

  4. Efficient localization of synchronous EEG source activities using a modified RAP-MUSIC algorithm.

    PubMed

    Liu, Hesheng; Schimpf, Paul H

    2006-04-01

    Synchronization across different brain regions is suggested to be a possible mechanism for functional integration. Noninvasive analysis of the synchronization among cortical areas is possible if the electrical sources can be estimated by solving the electroencephalography inverse problem. Among various inverse algorithms, spatio-temporal dipole fitting methods such as RAP-MUSIC and R-MUSIC have demonstrated superior ability in the localization of a restricted number of independent sources, and also have the ability to reliably reproduce temporal waveforms. However, these algorithms experience difficulty in reconstructing multiple correlated sources. Accurate reconstruction of correlated brain activities is critical in synchronization analysis. In this study, we modified the well-known inverse algorithm RAP-MUSIC to a multistage process which analyzes the correlation of candidate sources and searches for independent topographies (ITs) among precorrelated groups. Comparative studies were carried out on both simulated data and clinical seizure data. The results demonstrated superior performance with the modified algorithm compared to the original RAP-MUSIC in recovering synchronous sources and localizing the epileptiform activity. The modified RAP-MUSIC algorithm, thus, has potential in neurological applications involving significant synchronous brain activities.

  5. Occurrence and potential causes of androgenic activities in source and drinking water in China.

    PubMed

    Hu, Xinxin; Shi, Wei; Wei, Si; Zhang, Xiaowei; Feng, Jianfang; Hu, Guanjiu; Chen, Sulan; Giesy, John P; Yu, Hongxia

    2013-09-17

    The increased incidences of disorders of male reproductive tract as well as testicular and prostate cancers have been attributed to androgenic pollutants in the environment. Drinking water is one pathway of exposure through which humans can be exposed. In this study, both potencies of androgen receptor (AR) agonists and antagonists were determined in organic extracts of raw source water as well as finished water from waterworks, tap water, boiled water, and poured boiled water in eastern China. Ten of 13 samples of source water exhibited detectable AR antagonistic potencies with AR antagonist equivalents (Ant-AR-EQs) ranging from <15.3 (detection limit) to 140 μg flutamide/L. However, no AR agonistic activity was detected in any source water. All finished water from waterworks, tap water, boiled water, and poured boiled water exhibited neither AR agonistic nor antagonistic activity. Although potential risks are posed by source water, water treatment processes effectively removed AR antagonists. Boiling and pouring of water further removed these pollutants. Phthalate esters (PAEs) including diisobutyl phthalate (DIBP) and dibutyl phthalate (DBP) were identified as major contributors to AR antagonistic potencies in source waters. Metabolites of PAEs exhibited no AR antagonistic activity and did not increase potencies of PAEs when they coexist.

  6. Sources and magnitude of variability in pedometer-determined physical activity levels of youth

    PubMed Central

    Kim, So-Yeun; Park, Hye-Sang

    2015-01-01

    This study examined sources of variability in habitual physical activity of children, and the minimum number of days required for estimating children’s habitual physical activity levels using pedometers. A total of 31 children wore two pedometers during five weekdays and four weekend days. A two random facet completely crossed design was conducted with two-way analysis of variances across weekdays, weekends, and weekdays and weekend days combined. Moderate/high generalizability coefficients were estimated across all days. Primary sources of variability were variance components of the person and person by day interaction. Minimum numbers of days required for estimating habitual physical activity levels using a pedometer were five during weekdays. However, estimating habitual physical activity levels during weekends, and weekdays and weekend days combined was impractical. PMID:26730388

  7. Activation process in excitable systems with multiple noise sources: One and two interacting units.

    PubMed

    Franović, Igor; Todorović, Kristina; Perc, Matjaž; Vasović, Nebojša; Burić, Nikola

    2015-12-01

    We consider the coaction of two distinct noise sources on the activation process of a single excitable unit and two interacting excitable units, which are mathematically described by the Fitzhugh-Nagumo equations. We determine the most probable activation paths around which the corresponding stochastic trajectories are clustered. The key point lies in introducing appropriate boundary conditions that are relevant for a class II excitable unit, which can be immediately generalized also to scenarios involving two coupled units. We analyze the effects of the two noise sources on the statistical features of the activation process, in particular demonstrating how these are modified due to the linear or nonlinear form of interactions. Universal properties of the activation process are qualitatively discussed in the light of a stochastic bifurcation that underlies the transition from a stochastically stable fixed point to continuous oscillations.

  8. Towards absolute laser spectroscopic CO2 isotope ratio measurements

    NASA Astrophysics Data System (ADS)

    Anyangwe Nwaboh, Javis; Werhahn, Olav; Ebert, Volker

    2017-04-01

    Knowledge of isotope composition of carbon dioxide (CO2) in the atmosphere is necessary to identify sources and sinks of this key greenhouse gas. In the last years, laser spectroscopic techniques such as cavity ring-down spectroscopy (CRDS) and tunable diode laser absorption spectroscopy (TDLAS) have been shown to perform accurate isotope ratio measurements for CO2 and other gases like water vapour (H2O) [1,2]. Typically, isotope ratios are reported in literature referring to reference materials provided by e.g. the International Atomic Energy Agency (IAEA). However, there could be some benefit if field deployable absolute isotope ratio measurement methods were developed to address issues such as exhausted reference material like the Pee Dee Belemnite (PDB) standard. Absolute isotope ratio measurements would be particularly important for situations where reference materials do not even exist. Here, we present CRDS and TDLAS-based absolute isotope ratios (13C/12C ) in atmospheric CO2. We demonstrate the capabilities of the used methods by measuring CO2 isotope ratios in gas standards. We compare our results to values reported for the isotope certified gas standards. Guide to the expression of uncertainty in measurement (GUM) compliant uncertainty budgets on the CRDS and TDLAS absolute isotope ratio measurements are presented, and traceability is addressed. We outline the current impediments in realizing high accuracy absolute isotope ratio measurements using laser spectroscopic methods, propose solutions and the way forward. Acknowledgement Parts of this work have been carried out within the European Metrology Research Programme (EMRP) ENV52 project-HIGHGAS. The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union. References [1] B. Kühnreich, S. Wagner, J. C. Habig,·O. Möhler, H. Saathoff, V. Ebert, Appl. Phys. B 119:177-187 (2015). [2] E. Kerstel, L. Gianfrani, Appl. Phys. B 92, 439-449 (2008).

  9. Development of high-activity {sup 252}Cf sources for neutron brachytherapy

    SciTech Connect

    Martin, R.C.; Laxson, R.R.; Miller, J.H.; Wierzbicki, J.G.; Rivard, M.J.; Marsh, D.L.

    1996-10-01

    The Gershenson Radiation Oncology Center of Wayne State University (WSU), Detroit, Michigan, is using {sup 252}Cf medical sources for neutron brachytherapy. These sources are based on a 20-year-old design containing {le} 30 {micro}g {sup 252}Cf in the form of a cermet wire of Cf{sub 2}O{sub 3} in a palladium matrix. The Radiochemical Engineering Development Center (REDC) of Oak Ridge National Laboratory has been asked to develop tiny high-activity {sup 252}Cf neutron sources for use with remote afterloading equipment to reduce treatment times and dose to clinical personnel and to expedite treatment of brain and other tumors. To date, the REDC has demonstrated that {sup 252}Cf loadings can be greatly increased in cermet wires much smaller than before. Equipment designed for hot cell fabrication of these wires is being tested. A parallel program is under way to relicense the existing source design for fabrication at the REDC.

  10. Magnifying absolute instruments for optically homogeneous regions

    SciTech Connect

    Tyc, Tomas

    2011-09-15

    We propose a class of magnifying absolute optical instruments with a positive isotropic refractive index. They create magnified stigmatic images, either virtual or real, of optically homogeneous three-dimensional spatial regions within geometrical optics.

  11. A New Gimmick for Assigning Absolute Configuration.

    ERIC Educational Resources Information Center

    Ayorinde, F. O.

    1983-01-01

    A five-step procedure is provided to help students in making the assignment absolute configuration less bothersome. Examples for both single (2-butanol) and multi-chiral carbon (3-chloro-2-butanol) molecules are included. (JN)

  12. The Simplicity Argument and Absolute Morality

    ERIC Educational Resources Information Center

    Mijuskovic, Ben

    1975-01-01

    In this paper the author has maintained that there is a similarity of thought to be found in the writings of Cudworth, Emerson, and Husserl in his investigation of an absolute system of morality. (Author/RK)

  13. The Simplicity Argument and Absolute Morality

    ERIC Educational Resources Information Center

    Mijuskovic, Ben

    1975-01-01

    In this paper the author has maintained that there is a similarity of thought to be found in the writings of Cudworth, Emerson, and Husserl in his investigation of an absolute system of morality. (Author/RK)

  14. The cold adaptability of microorganisms with different carbon source in activated sludge treating synthetical wastewater.

    PubMed

    Niu, Chuan; Geng, Jinju; Ren, Hongqiang; Ding, Lili; Xu, Ke

    2012-11-01

    The cold adaptability of microorganisms with different carbon source under 5°C was studied in activated sludge for treating synthetical wastewater. Phospholipid fatty acid (PLFA) analysis indicated contents of unsaturated fatty acids in cell membrane at 5°C were 13.66% and 24.96% higher for glucose and sodium acetate source than that at 25°C. PLFA biomarkers showed more Gram-negative bacteria enriched than Gram-positive bacteria in low-temperature activated sludge. The Shannon-Wiener diversity analysis demonstrated glucose fed reactor in low temperature had lower PLFA diversity index (1.21-1.30) than that at 25°C and sodium acetate source was reverse (1.08-0.69). The 16S rRNA analysis manifested certain microbes were considerably suitable for existence under cold environment, most of which belong to Gram-negative bacteria.

  15. Coronal Hole Sources of Solar Wind Over ~Three Solar Activity Cycles

    NASA Astrophysics Data System (ADS)

    Luhmann, J. G.; Li, Y.; Arge, C. N.; Gazis, P. R.; Ulrich, R.

    2001-05-01

    Levine (Solar Physics v.79, 1982) was one of the first to use potential field source surface models of the coronal magnetic field, based on photospheric field observations, to infer the origins of the solar wind outflows reaching the ecliptic. Here we adopt and extend that approach to the last \\sim three solar cycles using the long archive of Mt. Wilson Observatory full-disk magnetograms. By tracing coronal field lines from within 20 degrees north and south of the source surface equator (at 2.5 Rs) to the Sun, we allow for variations due to the solar rotation axis tilt with respect to ecliptic north, and the still uncertain effects of the coronal/heliospheric currents on the divergence of coronal hole field lines. The results illustrate the modification of the polar hole source of near-ecliptic solar wind by the appearance of mid-latitude active regions in the rising phase of the solar cycle. As additional active regions emerge, midlatitude coronal holes associated with them rather abruptly take over as the dominant source through the solar maximum. While this result is not surprising, the long MWO record and continuous model display provide illuminating visualizations of coronal hole sources of the solar wind experienced by the planets through the solar cycle. Credence is lent to the results by favorable comparisons between average low heliolatitude magnetic field and solar wind velocity inferred from the source surface model and the Wang and Sheeley (Ap.J. v.355, 1990) approach, respectively, and observations near the earth. The alternate dominance of polar hole and active region sources, giving rise to differently phased interplanetary field and velocity cycles, explains how some trends in space weather are related to the solar magnetic cycle.

  16. Accumulated source imaging of brain activity with both low and high-frequency neuromagnetic signals

    PubMed Central

    Xiang, Jing; Luo, Qian; Kotecha, Rupesh; Korman, Abraham; Zhang, Fawen; Luo, Huan; Fujiwara, Hisako; Hemasilpin, Nat; Rose, Douglas F.

    2014-01-01

    Recent studies have revealed the importance of high-frequency brain signals (>70 Hz). One challenge of high-frequency signal analysis is that the size of time-frequency representation of high-frequency brain signals could be larger than 1 terabytes (TB), which is beyond the upper limits of a typical computer workstation's memory (<196 GB). The aim of the present study is to develop a new method to provide greater sensitivity in detecting high-frequency magnetoencephalography (MEG) signals in a single automated and versatile interface, rather than the more traditional, time-intensive visual inspection methods, which may take up to several days. To address the aim, we developed a new method, accumulated source imaging, defined as the volumetric summation of source activity over a period of time. This method analyzes signals in both low- (1~70 Hz) and high-frequency (70~200 Hz) ranges at source levels. To extract meaningful information from MEG signals at sensor space, the signals were decomposed to channel-cross-channel matrix (CxC) representing the spatiotemporal patterns of every possible sensor-pair. A new algorithm was developed and tested by calculating the optimal CxC and source location-orientation weights for volumetric source imaging, thereby minimizing multi-source interference and reducing computational cost. The new method was implemented in C/C++ and tested with MEG data recorded from clinical epilepsy patients. The results of experimental data demonstrated that accumulated source imaging could effectively summarize and visualize MEG recordings within 12.7 h by using approximately 10 GB of computer memory. In contrast to the conventional method of visually identifying multi-frequency epileptic activities that traditionally took 2–3 days and used 1–2 TB storage, the new approach can quantify epileptic abnormalities in both low- and high-frequency ranges at source levels, using much less time and computer memory. PMID:24904402

  17. Orion Absolute Navigation System Progress and Challenge

    NASA Technical Reports Server (NTRS)

    Holt, Greg N.; D'Souza, Christopher

    2012-01-01

    The absolute navigation design of NASA's Orion vehicle is described. It has undergone several iterations and modifications since its inception, and continues as a work-in-progress. This paper seeks to benchmark the current state of the design and some of the rationale and analysis behind it. There are specific challenges to address when preparing a timely and effective design for the Exploration Flight Test (EFT-1), while still looking ahead and providing software extensibility for future exploration missions. The primary onboard measurements in a Near-Earth or Mid-Earth environment consist of GPS pseudo-range and delta-range, but for future explorations missions the use of star-tracker and optical navigation sources need to be considered. Discussions are presented for state size and composition, processing techniques, and consider states. A presentation is given for the processing technique using the computationally stable and robust UDU formulation with an Agee-Turner Rank-One update. This allows for computational savings when dealing with many parameters which are modeled as slowly varying Gauss-Markov processes. Preliminary analysis shows up to a 50% reduction in computation versus a more traditional formulation. Several state elements are discussed and evaluated, including position, velocity, attitude, clock bias/drift, and GPS measurement biases in addition to bias, scale factor, misalignment, and non-orthogonalities of the accelerometers and gyroscopes. Another consideration is the initialization of the EKF in various scenarios. Scenarios such as single-event upset, ground command, and cold start are discussed as are strategies for whole and partial state updates as well as covariance considerations. Strategies are given for dealing with latent measurements and high-rate propagation using multi-rate architecture. The details of the rate groups and the data ow between the elements is discussed and evaluated.

  18. Kelvin and the absolute temperature scale

    NASA Astrophysics Data System (ADS)

    Erlichson, Herman

    2001-07-01

    This paper describes the absolute temperature scale of Kelvin (William Thomson). Kelvin found that Carnot's axiom about heat being a conserved quantity had to be abandoned. Nevertheless, he found that Carnot's fundamental work on heat engines was correct. Using the concept of a Carnot engine Kelvin found that Q1/Q2 = T1/T2. Thermometers are not used to obtain absolute temperatures since they are calculated temperatures.

  19. Absolute cross sections of compound nucleus reactions

    NASA Astrophysics Data System (ADS)

    Capurro, O. A.

    1993-11-01

    The program SEEF is a Fortran IV computer code for the extraction of absolute cross sections of compound nucleus reactions. When the evaporation residue is fed by its parents, only cumulative cross sections will be obtained from off-line gamma ray measurements. But, if one has the parent excitation function (experimental or calculated), this code will make it possible to determine absolute cross sections of any exit channel.

  20. The risks of absolute medical confidentiality.

    PubMed

    Crook, M A

    2013-03-01

    Some ethicists argue that patient confidentiality is absolute and thus should never be broken. I examine these arguments that when critically scrutinised, become porous. I will explore the concept of patient confidentiality and argue that although, this is a very important medical and bioethical issue, this needs to be wisely delivered to reduce third party harm or even detriment to the patient. The argument for absolute confidentiality is particularly weak when it comes to genetic information and inherited disease.

  1. Sources of Sex Education as a Function of Sex, Coital Activity, and Type of Information.

    ERIC Educational Resources Information Center

    Andre, Thomas; And Others

    The perceived importance of sources of sex education and the effects of gender, coital activity, and type of information were studied, and previous studies were assessed. Attention was directed to the relative contribution of parents, institutions, reading, and peers to the information about each of 35 different sexual topics of 116 male and 116…

  2. Promoting Conceptual Change through Active Learning Using Open Source Software for Physics Simulations

    ERIC Educational Resources Information Center

    Baser, Mustafa

    2006-01-01

    This paper reports upon an active learning approach that promotes conceptual change when studying direct current electricity circuits, using free open source software, "Qucs". The study involved a total of 102 prospective mathematics teacher students. Prior to instruction, students' understanding of direct current electricity was…

  3. The Main Sources of Intersubject Variability in Neuronal Activation for Reading Aloud

    ERIC Educational Resources Information Center

    Kherif, Ferath; Josse, Goulven; Seghier, Mohamed L.; Price, Cathy J.

    2009-01-01

    The aim of this study was to find the most prominent source of intersubject variability in neuronal activation for reading familiar words aloud. To this end, we collected functional imaging data from a large sample of subjects (n = 76) with different demographic characteristics such as handedness, sex, and age, while reading. The…

  4. The Main Sources of Intersubject Variability in Neuronal Activation for Reading Aloud

    ERIC Educational Resources Information Center

    Kherif, Ferath; Josse, Goulven; Seghier, Mohamed L.; Price, Cathy J.

    2009-01-01

    The aim of this study was to find the most prominent source of intersubject variability in neuronal activation for reading familiar words aloud. To this end, we collected functional imaging data from a large sample of subjects (n = 76) with different demographic characteristics such as handedness, sex, and age, while reading. The…

  5. 1994 Activity Report, National Synchrotron Light Source. Annual report, October 1, 1993-September 30, 1994

    SciTech Connect

    Rothman, E.Z.

    1995-05-01

    This report is a summary of activities carried out at the National Synchrotron Light Source during 1994. It consists of sections which summarize the work carried out in differing scientific disciplines, meetings and workshops, operations experience of the facility, projects undertaken for upgrades, administrative reports, and collections of abstracts and publications generated from work done at the facility.

  6. Self consistent, absolute calibration technique for photon number resolving detectors.

    PubMed

    Avella, A; Brida, G; Degiovanni, I P; Genovese, M; Gramegna, M; Lolli, L; Monticone, E; Portesi, C; Rajteri, M; Rastello, M L; Taralli, E; Traina, P; White, M

    2011-11-07

    Well characterized photon number resolving detectors are a requirement for many applications ranging from quantum information and quantum metrology to the foundations of quantum mechanics. This prompts the necessity for reliable calibration techniques at the single photon level. In this paper we propose an innovative absolute calibration technique for photon number resolving detectors, using a pulsed heralded photon source based on parametric down conversion. The technique, being absolute, does not require reference standards and is independent upon the performances of the heralding detector. The method provides the results of quantum efficiency for the heralded detector as a function of detected photon numbers. Furthermore, we prove its validity by performing the calibration of a Transition Edge Sensor based detector, a real photon number resolving detector that has recently demonstrated its effectiveness in various quantum information protocols.

  7. Risk Factor Modification and Projections of Absolute Breast Cancer Risk

    PubMed Central

    Decarli, Adriano; Schairer, Catherine; Pfeiffer, Ruth M.; Pee, David; Masala, Giovanna; Palli, Domenico

    2011-01-01

    Background Although modifiable risk factors have been included in previous models that estimate or project breast cancer risk, there remains a need to estimate the effects of changes in modifiable risk factors on the absolute risk of breast cancer. Methods Using data from a case–control study of women in Italy (2569 case patients and 2588 control subjects studied from June 1, 1991, to April 1, 1994) and incidence and mortality data from the Florence Registries, we developed a model to predict the absolute risk of breast cancer that included five non-modifiable risk factors (reproductive characteristics, education, occupational activity, family history, and biopsy history) and three modifiable risk factors (alcohol consumption, leisure physical activity, and body mass index). The model was validated using independent data, and the percent risk reduction was calculated in high-risk subgroups identified by use of the Lorenz curve. Results The model was reasonably well calibrated (ratio of expected to observed cancers = 1.10, 95% confidence interval [CI] = 0.96 to 1.26), but the discriminatory accuracy was modest. The absolute risk reduction from exposure modifications was nearly proportional to the risk before modifying the risk factors and increased with age and risk projection time span. Mean 20-year reductions in absolute risk among women aged 65 years were 1.6% (95% CI = 0.9% to 2.3%) in the entire population, 3.2% (95% CI = 1.8% to 4.8%) among women with a positive family history of breast cancer, and 4.1% (95% CI = 2.5% to 6.8%) among women who accounted for the highest 10% of the total population risk, as determined from the Lorenz curve. Conclusions These data give perspective on the potential reductions in absolute breast cancer risk from preventative strategies based on lifestyle changes. Our methods are also useful for calculating sample sizes required for trials to test lifestyle interventions. PMID:21705679

  8. Risk factor modification and projections of absolute breast cancer risk.

    PubMed

    Petracci, Elisabetta; Decarli, Adriano; Schairer, Catherine; Pfeiffer, Ruth M; Pee, David; Masala, Giovanna; Palli, Domenico; Gail, Mitchell H

    2011-07-06

    Although modifiable risk factors have been included in previous models that estimate or project breast cancer risk, there remains a need to estimate the effects of changes in modifiable risk factors on the absolute risk of breast cancer. Using data from a case-control study of women in Italy (2569 case patients and 2588 control subjects studied from June 1, 1991, to April 1, 1994) and incidence and mortality data from the Florence Registries, we developed a model to predict the absolute risk of breast cancer that included five non-modifiable risk factors (reproductive characteristics, education, occupational activity, family history, and biopsy history) and three modifiable risk factors (alcohol consumption, leisure physical activity, and body mass index). The model was validated using independent data, and the percent risk reduction was calculated in high-risk subgroups identified by use of the Lorenz curve. The model was reasonably well calibrated (ratio of expected to observed cancers = 1.10, 95% confidence interval [CI] = 0.96 to 1.26), but the discriminatory accuracy was modest. The absolute risk reduction from exposure modifications was nearly proportional to the risk before modifying the risk factors and increased with age and risk projection time span. Mean 20-year reductions in absolute risk among women aged 65 years were 1.6% (95% CI = 0.9% to 2.3%) in the entire population, 3.2% (95% CI = 1.8% to 4.8%) among women with a positive family history of breast cancer, and 4.1% (95% CI = 2.5% to 6.8%) among women who accounted for the highest 10% of the total population risk, as determined from the Lorenz curve. These data give perspective on the potential reductions in absolute breast cancer risk from preventative strategies based on lifestyle changes. Our methods are also useful for calculating sample sizes required for trials to test lifestyle interventions.

  9. Model of municipal solid waste source separation activity: a case study of Beijing.

    PubMed

    Yang, Lei; Li, Zhen-Shan; Fu, Hui-Zhen

    2011-02-01

    One major challenge faced by Beijing is dealing with the enormous amount of municipal solid waste (MSW) generated, which contains a high percentage of food waste. Source separation is considered an effective means of reducing waste and enhancing recycling. However, few studies have focused on quantification of the mechanism of source separation activity. Therefore, this study was conducted to establish a mathematical model of source separation activity (MSSA) that correlates the source separation ratio with the following parameters: separation facilities, awareness, separation transportation, participation atmosphere, environmental profit, sense of honor, and economic profit. The MSSA consisted of two equations, one related to the behavior generation stage and one related to the behavior stability stage. The source separation ratios of the residential community, office building, and primary and middle school were calculated using the MSSA. Data for analysis were obtained from a 1-yr investigation and a questionnaire conducted at 128 MSW clusters around Beijing. The results revealed that office buildings had an initial separation ratio of 80% and a stable separation ratio of 65.86%, whereas residential communities and primary and middle schools did not have a stable separation ratio. The MSSA curve took on two shapes. In addition, internal motivations and the separation transportation ratio were found to be key parameters of the MSSA. This model can be utilized for other cities and countries.

  10. Actively cooled plasma electrode for long pulse operations in a cesium-seeded negative ion source

    NASA Astrophysics Data System (ADS)

    Fujiwara, Yukio; Watanabe, Kazuhiro; Okumura, Yoshikazu; Trainham, Rusty; Jacquot, Claude

    2005-01-01

    An actively cooled plasma electrode has been developed for long pulse operation in a cesium-seeded negative ion source. To keep the electrode temperature at about 300°C, which is the optimum range of temperature to enhance cesium effects, the electrode cooling structure has been designed using three-dimensional numerical simulation assuming that the heat flux from the source plasma was 15W/cm2. Water cooling tubes were brazed to the plasma electrode substrate with spacers made of stainless steel, which acts as a thermal resistance. The fabricated plasma electrode has been tested in a cesium-seeded volume negative ion source called Kamaboko source. The temperature of the electrode reached 280°C for the arc power of 41kW, which is the operating condition required for producing D- beams with current densities exceeding 20mA/cm2. It was demonstrated that the actively cooled plasma electrode is applicable to long pulse operations, meeting the temperature requirement for optimizing the surface-production process of negative ions in the cesium-seeded ion source.

  11. Antimicrobial activity of bacterial isolates from different floral sources of honey.

    PubMed

    Lee, Hyungjae; Churey, John J; Worobo, Randy W

    2008-08-15

    More than two thousand bacterial strains isolated from six US domestic honeys and two manuka honeys from New Zealand were screened for production of antimicrobial compounds. A high incidence of antimicrobial inhibition determined by deferred inhibition assays was observed with the bacterial isolates from all eight honey samples. In total, 2217 isolates out of 2398 strains (92.5% of total isolates) exhibited antimicrobial activity against at least one of the tested microorganisms. Antifungal activity by bacterial isolates originating from the eight honeys ranged from 44.4% to 98.0%. Bacterial isolates from manuka honey (MH1) exhibited antimicrobial activity against Bacillus subtilis ATCC 6633 and Bacillus cereus F4552, at 51.5% and 53.3% of the isolates, respectively. However, less than 30% of the bacterial isolates from the other manuka honey (MH2) and six domestic honey sources exhibited anti-Bacillus activity. Listeria monocytogenes F2-586 1053 showed higher overall rates of sensitivity to between 11 and 66% of the bacterial isolates. The high rate of antimicrobial activity exhibited by the bacterial strains isolated from different honey sources could provide potential sources of novel antimicrobial compounds.

  12. Bioanalytical and instrumental analysis of estrogenic activities in drinking water sources from Yangtze River Delta.

    PubMed

    Hu, Xinxin; Shi, Wei; Cao, Fu; Hu, Guanjiu; Hao, Yingqun; Wei, Si; Wang, Xinru; Yu, Hongxia

    2013-02-01

    The estrogenic activities of source water from Yangtze River, Huaihe River, Taihu Lake and groundwater in Yangtze River Delta in the dry and wet season were determined by use of reporter gene assays based on African green monkey kidney (CV-1) cell lines. Higher estrogenic activities were observed in the dry season, and the estrogenic potentials in water samples from Taihu Lake were greater than other river basins. None of the samples from groundwater showed estrogen receptor (ER) agonist activity. The 17β-Estradiol (E2) equivalents (EEQs) of water samples in the dry season ranged from 9.41×10(-1) to 1.20×10(1) ng E2 L(-1). In the wet season, EEQs of all the water samples were below the detection limit as 9.00×10(-1) ng E2 L(-1) except for one sample from Huaihe River. The highest contribution of E2 was detected in Yangtze River as 99% of estrogenic activity. Nonylphenol (NP, 100% detection rate) and octylphenol (OP, 100% detection rate) might also be responsible for the estrogenic activities in water sources. Potential health risk induced by the estrogenic chemicals in source water may be posed to the residents through water drinking.

  13. A review on biological sources, chemistry and pharmacological activities of pinostrobin.

    PubMed

    Patel, Neeraj K; Jaiswal, Gaurav; Bhutani, Kamlesh K

    2016-09-01

    Pinostrobin, a dietary bioflavonoid discovered more than 6 decades ago in the heart-wood of pine (Pinus strobus), has depicted many pharmacological activities including anti-viral, anti-oxidant, anti-leukaemic, anti-inflammatory and anti-aromatase activities. It is an inhibitor of sodium channel and Ca(2+) signalling pathways and also inhibits intestinal smooth muscle contractions. In spite of the fact that pinostrobin has an application as functional foods, till-to-date no comprehensive review on pinostrobin has been carried out. Hence, the present review deals with the biological sources, chemistry and pharmacological activities of pinostrobin.

  14. The effects of negative emotion on encoding-related neural activity predicting item and source recognition.

    PubMed

    Yick, Yee Ying; Buratto, Luciano Grüdtner; Schaefer, Alexandre

    2015-07-01

    We report here a study that obtained reliable effects of emotional modulation of a well-known index of memory encoding--the electrophysiological "Dm" effect--using a recognition memory paradigm followed by a source memory task. In this study, participants performed an old-new recognition test of emotionally negative and neutral pictures encoded 1 day before the test, and a source memory task involving the retrieval of the temporal context in which pictures had been encoded. Our results showed that Dm activity was enhanced for all emotional items on a late positivity starting at ~400 ms post-stimulus onset, although Dm activity for high arousal items was also enhanced at an earlier stage (200-400 ms). Our results also showed that emotion enhanced Dm activity for items that were both recognised with or without correct source information. Further, when only high arousal items were considered, larger Dm amplitudes were observed if source memory was accurate. Three main conclusions are drawn from these findings. First, negative emotion can enhance encoding processes predicting the subsequent recognition of central item information. Second, if emotion reaches high levels of arousal, the encoding of contextual details can also be enhanced over and above the effects of emotion on central item encoding. Third, the morphology of our ERPs is consistent with a hybrid model of the role of attention in emotion-enhanced memory (Pottage and Schaefer, 2012). Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. 26 CFR 1.863-9 - Source of income derived from communications activity under section 863(a), (d), and (e).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... sections 861, 862, 863, and 865. Notwithstanding that a communications activity would qualify as space or... from foreign communications activity is from sources without the United States. (e) Source of space... space/ocean communications activity is determined under section 863(d) and the regulations thereunder...

  16. Nitrogen Source Activates TOR (Target of Rapamycin) Complex 1 via Glutamine and Independently of Gtr/Rag Proteins*

    PubMed Central

    Stracka, Daniele; Jozefczuk, Szymon; Rudroff, Florian; Sauer, Uwe; Hall, Michael N.

    2014-01-01

    The evolutionary conserved TOR complex 1 (TORC1) activates cell growth in response to nutrients. In yeast, TORC1 responds to the nitrogen source via a poorly understood mechanism. Leucine, and perhaps other amino acids, activates TORC1 via the small GTPases Gtr1 and Gtr2, orthologs of the mammalian Rag GTPases. Here we investigate the activation of TORC1 by the nitrogen source and how this might be related to TORC1 activation by Gtr/Rag. The quality of the nitrogen source, as defined by its ability to promote growth and glutamine accumulation, directly correlates with its ability to activate TORC1 as measured by Sch9 phosphorylation. Preferred nitrogen sources stimulate rapid, sustained Sch9 phosphorylation and glutamine accumulation. Inhibition of glutamine synthesis reduces TORC1 activity and growth. Poor nitrogen sources stimulate rapid but transient Sch9 phosphorylation. A Gtr1 deficiency prevents the transient stimulation of TORC1 but does not affect the sustained TORC1 activity in response to good nitrogen sources. These findings suggest that the nitrogen source must be converted to glutamine, the preferred nitrogen source in yeast, to sustain TORC1 activity. Furthermore, sustained TORC1 activity is independent of Gtr/Rag. Thus, the nitrogen source and Gtr/Rag activate TORC1 via different mechanisms. PMID:25063813

  17. Crosswell CASSM(Continuous Active-Source Seismic Monitoring): Recent Developments (Invited)

    NASA Astrophysics Data System (ADS)

    Daley, T. M.; Niu, F.; Ajo Franklin, J. B.; Solbau, R.; Silver, P. G.

    2009-12-01

    Continuous active-source monitoring using borehole sources and sensors in a crosswell configuration has proven to be a useful tool for monitoring subsurface processes (Silver, et al, 2007; Daley, et al, 2007; Niu, et al, 2008). This recent work has focused on two applications: monitoring stress changes related to seismicity and monitoring changes in fluid distribution related to geologic storage of CO2. Field tests have demonstrated precision in travel time measurement of up to 1.1 x 10-7 s, and in velocity perturbation measurement of up to 1.1 x 10-5 (Niu, et al 2008). In this talk I will summarize our preceding work and discuss current developments. Current efforts address both hardware and design challenges to improving the methodology. Hardware issues include deployment of multiple piezoelectric sources in shallow and deep boreholes, source and sensor deployment on tubing inside casing, and deployment with other monitoring instrumentation. Design issues are focused on use of multiple sources and/or sensors to obtain optimal spatial resolution for monitoring processes in the interwell region. This design issue can be investigated with optimal experiment design theory. New field experiments for monitoring seismicity (at SAFOD) and CO2 injection (at a US Dept of Energy pilot) are in the design/deployment stage. Current status of these projects will be discussed. References: Silver, P.G., Daley, T.M., Niu, F., Majer, E.L., 2007, Active source monitoring of crosswell seismic travel time for stress induced changes, Bulletin of Seismological Society of America, v97, n1B, p281-293. Daley, T.M., R.D. Solbau, J.B. Ajo-Franklin, S.M. Benson, 2007, Continuous active-source monitoring of CO2 injection in a brine aquifer, Geophysics, v72, n5, pA57-A61, DOI:10.1190/1.2754716. Niu, F., Silver, P.G., Daley, T.M., Cheng, X., Majer, E.L., 2008, Preseismic velocity changes observed from active source monitoring at the Parkfield SAFOD drill site, Nature, 454, 204-208, DOI:10

  18. Shear bond strength to enamel after power bleaching activated by different sources.

    PubMed

    Can-Karabulut, Deniz C; Karabulut, Baris

    2010-01-01

    The purpose of the present study was to evaluate enamel bond strength of a composite resin material after hydrogen peroxide bleaching, activated by a diode laser (LaserSmile), an ozone device (HealOzone), a light-emitting diode (BT Cool whitening system), and a quartz-Plus. Fifty extracted caries-free permanent incisors were used in this study. Thirty-eight percent hydrogen peroxidegel was applied to sound, flattened labial enamel surfaces and activated by different sources. Enamel surfaces that had received no treatment were used as control samples. Bonding agent was applied according to the manufacturer's instructions and the adhesion test was performed according to ISO/TS 11405. Statistical analysis showed significant influence of the different activation technique of hydrogen peroxide on shear bond strength to enamel (ANOVA, LSD, P < 0.05). The data in this vitro explorative study suggest the activation of hydrogen peroxide by different sources may further affect the shear bond strength of subsequent composite resin restoration to enamel. Within the limitations of this in vitro study, further studies examining the structural changes of activated hydrogen peroxide-treated enamel are needed. Due to the different activation methods; duration of light irradiation effects, longer time periods may be needed before application of adhesive restorations to enamel, compared with non-activated bleaching.

  19. Enzyme activities and arylsulfatase protein content of dust and the soil source: biochemical fingerprints?

    PubMed

    Acosta-Martínez, V; Zobeck, T M

    2004-01-01

    Little is known about the potential of enzyme activities, which are sensitive to soil properties and management, for the characterization of dust properties. Enzyme activities may be among the dust properties key to identifying the soil source of dust. We generated dust (27 and 7 microm) under controlled laboratory conditions from agricultural soils (0-5 cm) with history of continuous cotton (Gossypium hirsutum L.) or cotton rotated with peanut (Arachis hypogaea L.), sorghum [Sorghum bicolor (L.) Moench], rye (Secale cereale L.), or wheat (Triticum aestivum L.) under different water management (irrigated or dryland) and tillage (conservation or conventional) systems. The 27- and 7-microm dust samples showed activities of beta-glucosidase, alkaline phosphatase, and arylsulfatase, which are related to cellulose degradation and phosphorus and sulfur mineralization in soil, respectively. Dust samples generated from a loam and sandy clay loam showed higher enzyme activities compared with dust samples from a fine sandy loam. Enzyme activities of dust samples were significantly correlated to the activities of the soil source with r > 0.74 (P < 0.01). The arylsulfatase proteins contents of the soils (0.04-0.65 mg protein kg(-1) soil) were lower than values reported for soils from other regions, but still dust contained arylsulfatase protein. The three enzyme activities studied, as a group, separated the dust samples due to the crop rotation or tillage practice history of the soil source. The results indicated that the enzyme activities of dust will aid in providing better characterization of dust properties and expanding our understanding of soil and air quality impacts related to wind erosion.

  20. Active source requirements for assay of sludge drums on the BIR WIT system

    SciTech Connect

    Roberson, G.P.; Camp, D.C.

    1998-04-27

    The design of the active source for active and passive computed tomography (A&PCT) is critical with respect to accuracy and throughput. The A&PCT active source requirements are highly dependent upon the attenuation properties of the waste matrix within the drum. On of the most highly attenuating waste matrices is sludge. This waste stream will consist of solidified aqueous waste consisting of IDC 001 first stage sludge and IDC 007 wet sludge. Also, the stream consists of solidified organic waste known as code IDC 003 organic setups. We have evaluated the sludge drum data that was previously acquired on the WIT system and have determined that the active source activity must be increased to provide reasonable throughput. The sludge drum that is evaluated here is drum CEPRF11. CEPRF11 is a test drum that was part of the Nondestructive Assay system Capability Evaluation Project (CEP) and contained an actual Rocky Flats waste that is categorized as code 003 solidified organic waste. The full drum was evaluated and found to be somewhat homogenous; therefore, a single slice is arbitrarily chosen to represent the entire drum. Slice number 8 is used and is located approximately at the center of the drum. Figure 1 shows the averaged projections for different energies derived from the active sinogram of slice number 8 from the CEPRF11 drum. This is the average of all the projections of slice 8 taken over 180 degrees with an active integration time of 6 seconds. Figure 2 is also a graph showing the average of all the projections for slice 8; however, the active integration time is 30 seconds.

  1. Jasminum flexile flower absolute from India--a detailed comparison with three other jasmine absolutes.

    PubMed

    Braun, Norbert A; Kohlenberg, Birgit; Sim, Sherina; Meier, Manfred; Hammerschmidt, Franz-Josef

    2009-09-01

    Jasminum flexile flower absolute from the south of India and the corresponding vacuum headspace (VHS) sample of the absolute were analyzed using GC and GC-MS. Three other commercially available Indian jasmine absolutes from the species: J. sambac, J. officinale subsp. grandiflorum, and J. auriculatum and the respective VHS samples were used for comparison purposes. One hundred and twenty-one compounds were characterized in J. flexile flower absolute, with methyl linolate, benzyl salicylate, benzyl benzoate, (2E,6E)-farnesol, and benzyl acetate as the main constituents. A detailed olfactory evaluation was also performed.

  2. Perceiving pitch absolutely: comparing absolute and relative pitch possessors in a pitch memory task.

    PubMed

    Schulze, Katrin; Gaab, Nadine; Schlaug, Gottfried

    2009-08-27

    The perceptual-cognitive mechanisms and neural correlates of Absolute Pitch (AP) are not fully understood. The aim of this fMRI study was to examine the neural network underlying AP using a pitch memory experiment and contrasting two groups of musicians with each other, those that have AP and those that do not. We found a common activation pattern for both groups that included the superior temporal gyrus (STG) extending into the adjacent superior temporal sulcus (STS), the inferior parietal lobule (IPL) extending into the adjacent intraparietal sulcus (IPS), the posterior part of the inferior frontal gyrus (IFG), the pre-supplementary motor area (pre-SMA), and superior lateral cerebellar regions. Significant between-group differences were seen in the left STS during the early encoding phase of the pitch memory task (more activation in AP musicians) and in the right superior parietal lobule (SPL)/intraparietal sulcus (IPS) during the early perceptual phase (ITP 0-3) and later working memory/multimodal encoding phase of the pitch memory task (more activation in non-AP musicians). Non-significant between-group trends were seen in the posterior IFG (more in AP musicians) and the IPL (more anterior activations in the non-AP group and more posterior activations in the AP group). Since the increased activation of the left STS in AP musicians was observed during the early perceptual encoding phase and since the STS has been shown to be involved in categorization tasks, its activation might suggest that AP musicians involve categorization regions in tonal tasks. The increased activation of the right SPL/IPS in non-AP musicians indicates either an increased use of regions that are part of a tonal working memory (WM) network, or the use of a multimodal encoding strategy such as the utilization of a visual-spatial mapping scheme (i.e., imagining notes on a staff or using a spatial coding for their relative pitch height) for pitch information.

  3. Carbon and Nitrogen Sources Influence Tricalcium Phosphate Solubilization and Extracellular Phosphatase Activity by Talaromyces flavus.

    PubMed

    Stefanoni Rubio, P J; Godoy, M S; Della Mónica, I F; Pettinari, M J; Godeas, A M; Scervino, J M

    2016-01-01

    The aim of this work was to study phosphate (P) solubilization (and the processes involved in this event) by Talaromyces flavus (BAFC 3125) as a function of carbon and/or nitrogen sources. P solubilization was evaluated in NBRIP media supplemented with different carbon (glucose, sorbitol, sucrose, and fructose) and nitrogen (L-asparagine, urea, ammonium sulfate (AS), and ammonium nitrate (AN) combinations. The highest P solubilization was related to the highest organic acid production (especially gluconic acid) and pH drop for those treatments where glucose was present. Also P solubilization was higher when an inorganic nitrogen source was supplemented to the media when compared to an organic one. Although not being present an organic P source, phosphatase activity was observed. This shows that P mineralization and P solubilization can occur simultaneously, and that P mineralization is not induced by the enzyme substrate. The combination that showed highest P solubilization was for AN-glucose. The highest acid phosphatase activity was for AS-fructose, while for alkaline phosphatase were for AS-fructose and AN-fructose. Acid phosphatase activity was higher than alkaline. P solubilization and phosphatase activity (acid and alkaline) were influenced by the different carbon-nitrogen combinations. A better understanding of phosphate-solubilizing fungi could bring a better use of soil P.

  4. fMRI activation patterns in an analytic reasoning task: consistency with EEG source localization

    NASA Astrophysics Data System (ADS)

    Li, Bian; Vasanta, Kalyana C.; O'Boyle, Michael; Baker, Mary C.; Nutter, Brian; Mitra, Sunanda

    2010-03-01

    Functional magnetic resonance imaging (fMRI) is used to model brain activation patterns associated with various perceptual and cognitive processes as reflected by the hemodynamic (BOLD) response. While many sensory and motor tasks are associated with relatively simple activation patterns in localized regions, higher-order cognitive tasks may produce activity in many different brain areas involving complex neural circuitry. We applied a recently proposed probabilistic independent component analysis technique (PICA) to determine the true dimensionality of the fMRI data and used EEG localization to identify the common activated patterns (mapped as Brodmann areas) associated with a complex cognitive task like analytic reasoning. Our preliminary study suggests that a hybrid GLM/PICA analysis may reveal additional regions of activation (beyond simple GLM) that are consistent with electroencephalography (EEG) source localization patterns.

  5. Jets and sources of activity on comet 67P/Churyumov-Gerasimenko

    NASA Astrophysics Data System (ADS)

    Vincent, Jean-Baptiste; Sierks, Holger; Lara, Luisa; Gutierez, Pedro; Rodrigo, Rafael; Pajola, Maurizio; Oklay, Nilda; Knollenberg, Jörg; Bertini, Ivano; Lin, Zhong-Yi; Ip, Wing-Huen; Thomas, Nicolas; Davidsson, Björn; Mottola, Stefano; Lowry, Stephen; Fornasier, Sonia; Bodewits, Dennis; Massironi, Matteo; A'Hearn, Mike; Keller, Uwe

    2015-04-01

    A major goal of the Rosetta mission is to study the evolution of a comet through activity. Understanding the physical processes reshaping the nucleus will help us to look back in time and reconstruct what pristine comet surface looked like at the time of its formation. A key question is how and why cometary activity is spatially distributed over the nucleus. We trace the manifestation of this activity in the coma, in the form of narrow dust features, hereafter called "jets", expanding straight for at least some distance from the source on the nucleus. We follow these jets down to the surface to constrain the location of active areas and better understand the physical processes underlying activity. Jets are a type of highly localized activity. They appear as fuzzy streams of bright material arising from specific areas on the nucleus surface. They are typically detected against a dark background, which can be either empty space or casted shadows. Jets are seen at all scales, down to the resolution of the OSIRIS images. The smallest features detected so far are a few pixels across, which translates into a couple of meters at most. They have a typical column density a few percent higher than the ambient medium [1]. At the highest spatial resolution these jets appear as a combination of thinner features which can be traced directly to specific morphologic features on the surface. By monitoring the activity and observing these jets from different angles we can reconstruct their three-dimensional structure and identify their source regions. We present here the first results of this inversion, covering the epoch from August to December 2014. We show how the spatial distribution of jet sources expands with time. While active areas were found mainly in the transition region between the two lobes in August 2014 (3.6 AU), they could be observed all over the Northern hemisphere in December 2014 (2.8 AU). Jet sources are associated to different types of terrains: smooth areas

  6. Intracerebral propagation of interictal activity in partial epilepsy: implications for source localisation.

    PubMed Central

    Alarcon, G; Guy, C N; Binnie, C D; Walker, S R; Elwes, R D; Polkey, C E

    1994-01-01

    than the ictal onset zone and their interictal propagation to the surface is independent of their capacity to trigger seizures. It is concluded that: (1) the deep-to-surface ratios of electromagnetic fields from deep sources are extremely low on the scalp; (2) single dipoles or a limited number of dipoles are not adequate for surgical assessment; (3) the correct localisation of the onset of interictal activity does not necessarily imply the onset of seizures in the region or in the same hemisphere. It is suggested that, until volume conduction and neurophysiological propagation can be distinguished, semiempirical correlations between symptomatology, surgical outcome, and detailed presurgical modeling of the neocortical projection patterns by combined MEG, EEG, and MRI could be more fruitful than source localization with unrealistic source models. PMID:8163992

  7. Universal Cosmic Absolute and Modern Science

    NASA Astrophysics Data System (ADS)

    Kostro, Ludwik

    The official Sciences, especially all natural sciences, respect in their researches the principle of methodic naturalism i.e. they consider all phenomena as entirely natural and therefore in their scientific explanations they do never adduce or cite supernatural entities and forces. The purpose of this paper is to show that Modern Science has its own self-existent, self-acting, and self-sufficient Natural All-in Being or Omni-Being i.e. the entire Nature as a Whole that justifies the scientific methodic naturalism. Since this Natural All-in Being is one and only It should be considered as the own scientifically justified Natural Absolute of Science and should be called, in my opinion, the Universal Cosmic Absolute of Modern Science. It will be also shown that the Universal Cosmic Absolute is ontologically enormously stratified and is in its ultimate i.e. in its most fundamental stratum trans-reistic and trans-personal. It means that in its basic stratum. It is neither a Thing or a Person although It contains in Itself all things and persons with all other sentient and conscious individuals as well, On the turn of the 20th century the Science has begun to look for a theory of everything, for a final theory, for a master theory. In my opinion the natural Universal Cosmic Absolute will constitute in such a theory the radical all penetrating Ultimate Basic Reality and will substitute step by step the traditional supernatural personal Absolute.

  8. Absolute Humidity and Pandemic Versus Epidemic Influenza

    PubMed Central

    Shaman, Jeffrey; Goldstein, Edward; Lipsitch, Marc

    2011-01-01

    Experimental and epidemiologic evidence indicates that variations of absolute humidity account for the onset and seasonal cycle of epidemic influenza in temperate regions. A role for absolute humidity in the transmission of pandemic influenza, such as 2009 A/H1N1, has yet to be demonstrated and, indeed, outbreaks of pandemic influenza during more humid spring, summer, and autumn months might appear to constitute evidence against an effect of humidity. However, here the authors show that variations of the basic and effective reproductive numbers for influenza, caused by seasonal changes in absolute humidity, are consistent with the general timing of pandemic influenza outbreaks observed for 2009 A/H1N1 in temperate regions, as well as wintertime transmission of epidemic influenza. Indeed, absolute humidity conditions correctly identify the region of the United States vulnerable to a third, wintertime wave of pandemic influenza. These findings suggest that the timing of pandemic influenza outbreaks is controlled by a combination of absolute humidity conditions, levels of susceptibility, and changes in population-mixing and contact rates. PMID:21081646

  9. EVIDENCE FOR INFRARED-FAINT RADIO SOURCES AS z > 1 RADIO-LOUD ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Huynh, Minh T.; Norris, Ray P.; Siana, Brian; Middelberg, Enno

    2010-02-10

    Infrared-Faint Radio Sources (IFRSs) are a class of radio objects found in the Australia Telescope Large Area Survey which have no observable mid-infrared counterpart in the Spitzer Wide-area Infrared Extragalactic (SWIRE) survey. The extended Chandra Deep Field South now has even deeper Spitzer imaging (3.6-70 {mu}m) from a number of Legacy surveys. We report the detections of two IFRS sources in IRAC images. The non-detection of two other IFRSs allows us to constrain the source type. Detailed modeling of the spectral energy distribution of these objects shows that they are consistent with high-redshift (z {approx}> 1) active galactic nuclei.

  10. A new activated primary tank developed for recovering carbon source and its application.

    PubMed

    Jin, Pengkang; Wang, Xianbao; Zhang, Qionghua; Wang, Xiaochang; Ngo, Huu Hao; Yang, Lei

    2016-01-01

    A novel activated primary tank process (APT) was developed for recovering carbon source by fermentation and elutriation of primary sludge. The effects of solids retention time (SRT), elutriation intensity (G) and return sludge ratio (RSR) on this recovery were evaluated in a pilot scale reactor. Results indicated that SRT significantly influenced carbon source recovery, and mechanical elutriation could promote soluble COD (SCOD) and VFA yields. The optimal conditions of APT were SRT=5d, G=152s(-1) and RSR=10%, SCOD and VFA production were 57.0mg/L and 21.7mg/L. Particulate organic matter in sludge was converted into SCOD and VFAs as fermentative bacteria were significantly enriched in APT. Moreover, the APT process was applied in a wastewater treatment plant to solve the problem of insufficient carbon source. The outcomes demonstrated that influent SCOD of biological tank increased by 31.1%, which improved the efficiency of removing nitrogen and phosphorus.

  11. Four Years of Absolute Gravity in the Taiwan Orogen (AGTO)

    NASA Astrophysics Data System (ADS)

    Mouyen, M.; Masson, F.; Hwang, C.; Cheng, C.; Le Moigne, N.; Lee, C.; Kao, R.; Hsieh, N.

    2009-12-01

    AGTO is a scientific project between Taiwanese and French institutes which aim is to improve tectonic knowledge of Taiwan primarily using absolute gravity measurements and permanent GPS stations. Both tools are indeed useful to study vertical movements and mass transfers involved in mountain building, a major process in Taiwan located at the convergent margin between Philippine Sea plate and Eurasian plate. This convergence results in two subductions north and south of Taiwan (Ryukyu and Manilla trenches, respectively), while the center is experiencing collision. These processes make Taiwan very active tectonically, as illustrated by numerous large earthquakes and rapid uplift of the Central Range. High slopes of Taiwan mountains and heavy rains brought by typhoons together lead to high landslides and mudflows risks. Practically, absolute gravity measurements have been yearly repeated since 2006 along a transect across south Taiwan, from Penghu to Lutao island, using FG5 absolute gravimeters. This transect contains ten sites for absolute measurements and has been densified in 2008 by incorporating 45 sites for relative gravity measurements with CG5 gravimeters. At the end of 2009, the relative gravity network will be densified again in its eastern part, i.e. in the Longitudinal Valley and the Central Range. A fourth set of absolute gravity measurements will also be performed at the same period. Most of the absolute sites have been measured with a good accuracy, about 1 or 2 μGal. Only the site located in Tainan University has higher standard deviation, due to the city noise. The stronger change in gravity reaches -7 μGal a -1 west of the Longitudinal Valley and might be explained by tectonic movement along a fault. A large decrease of -5 μGal a-1 is also measured in Tainan city and could be correlated with uplift of this region, also denoted by InSAR, leveling and GPS. Changes occurring in the Central Range are more difficult to interpret due to the small

  12. Four Years of Absolute Gravity in the Taiwan Orogen (AGTO)

    NASA Astrophysics Data System (ADS)

    Mouyen, Maxime; Masson, Frédéric; Hwang, Cheinway; Cheng, Ching-Chung; Le Moigne, Nicolas; Lee, Chiung-Wu; Kao, Ricky; Hsieh, Nicky

    2010-05-01

    AGTO is a scientific project between Taiwanese and French institutes, which aim is to improve tectonic knowledge of Taiwan primarily using absolute gravity measurements and permanent GPS stations. Both tools are indeed useful to study vertical movements and mass transfers involved in mountain building, a major process in Taiwan located at the convergent margin between Philippine Sea plate and Eurasian plate. This convergence results in two subductions north and south of Taiwan (Ryukyu and Manilla trenches, respectively), while the center is experiencing collision. These processes make Taiwan very active tectonically, as illustrated by numerous large earthquakes and rapid uplift of the Central Range. High slopes of Taiwan mountains and heavy rains brought by typhoons together lead to high landslides and mudflows risks. Practically, absolute gravity measurements have been yearly repeated since 2006 along a transect across south Taiwan, from Penghu to Lutao islands, using FG5 absolute gravimeters. This transect contains ten sites for absolute measurements and has been densified in 2008 by incorporating 45 sites for relative gravity measurements with CG5 gravimeters. The last relative and absolute measurements have been performed in November 2009. Most of the absolute sites have been measured with a good accuracy, about 1 or 2 ?Gal. Only the site located in Tainan University has higher standard deviation, due to the city noise. We note that absolute gravity changes seem to follow a trend in every site. However, straightforward tectonic interpretation of these trends is not valuable as many non-tectonic effects are supposed to change g with time, like groundwater or erosion. Estimating and removing these effects leads to a tectonic gravity signal, which has theoretically two origins : deep mass transfers around the site and vertical movements of the station. The latter can be well constrained by permanent GPS stations located close to the measurement pillar. Deep mass

  13. Influences of influent carbon source on extracellular polymeric substances (EPS) and physicochemical properties of activated sludge.

    PubMed

    Ye, Fenxia; Peng, Ge; Li, Ying

    2011-08-01

    It is necessary to understand the bioflocculation, settling and dewatering characteristics in the activated sludge process in order to establish more efficient operational strategies. The influences of carbon source on the extracellular polymeric substances (EPS) and flocculation, settling and dewatering properties of the activated sludge were investigated. Laboratory-scale completely mixed activated sludge processes were used to grow the activated sludge with different carbon sources of starch, glucose and sodium acetate. The sludge fed with acetate had highest loosely bound EPS (LB-EPS) and that fed with starch lowest. The amount of tightly bound EPS (TB-EPS), protein content in LB-EPS, polysaccharide content and protein contents in TB-EPS, were independent of the influent carbon source. The polysaccharide content in LB-EPS of the activated sludge fed with sodium acetate was lower slightly than those of starch and glucose. The sludge also had a nearly consistent flocs size and the sludge volume index (SVI) value. ESS content of the sludge fed with sodium acetate was higher initially, although it was similar to those fed with glucose and starch finally. However, the specific resistance to filtration and normalized capillary suction time fluctuated first, but finally were stable at around 5.0×10(8)mkg(-1) and 3.5 s Lg(-1) SS, respectively. Only the protein content in LB-EPS weakly correlated with the flocs size and SVI of the activated sludge. But there was no correlation between any other EPS contents or components and the physicochemical properties of the activated sludge.

  14. Methods to calibrate the absolute receive sensitivity of single-element, focused transducers.

    PubMed

    Rich, Kyle T; Mast, T Douglas

    2015-09-01

    Absolute pressure measurements of acoustic emissions by single-element, focused passive cavitation detectors would be facilitated by improved wideband receive calibration techniques. Here, calibration methods were developed to characterize the absolute, frequency-dependent receive sensitivity of a spherically focused, single-element transducer using pulse-echo and pitch-catch techniques. Validation of these calibration methods on a focused receiver were made by generating a pulse from a small diameter source at the focus of the transducer and comparing the absolute pressure measured by a calibrated hydrophone to that of the focused transducer using the receive sensitivities determined here.

  15. Effect of source-separated urine storage on estrogenic activity detected using bioluminescent yeast Saccharomyces cerevisiae.

    PubMed

    Jaatinen, Sanna; Kivistö, Anniina; Palmroth, Marja R T; Karp, Matti

    2016-09-01

    The objective was to demonstrate that a microbial whole cell biosensor, bioluminescent yeast, Saccharomyces cerevisiae (BMAEREluc/ERα) can be applied to detect overall estrogenic activity from fresh and stored human urine. The use of source-separated urine in agriculture removes a human originated estrogen source from wastewater influents, subsequently enabling nutrient recycling. Estrogenic activity in urine should be diminished prior to urine usage in agriculture in order to prevent its migration to soil. A storage period of 6 months is required for hygienic reasons; therefore, estrogenic activity monitoring is of interest. The method measured cumulative female hormone-like activity. Calibration curves were prepared for estrone, 17β-estradiol, 17α- ethinylestradiol and estriol. Estrogen concentrations of 0.29-29,640 μg L(-1) were detectable while limit of detection corresponded to 0.28-35 μg L(-1) of estrogens. The yeast sensor responded well to fresh and stored urine and gave high signals corresponding to 0.38-3,804 μg L(-1) of estrogens in different urine samples. Estrogenic activity decreased during storage, but was still higher than in fresh urine implying insufficient storage length. The biosensor was suitable for monitoring hormonal activity in urine and can be used in screening anthropogenic estrogen-like compounds interacting with the receptor.

  16. Investigating effectiveness of activated carbons of natural sources on various supercapacitors

    NASA Astrophysics Data System (ADS)

    Faisal, Md. Shahnewaz Sabit; Rahman, Muhammad M.; Asmatulu, Ramazan

    2016-04-01

    Activated carbon can be produced from natural sources, such as pistachio and acorn shells, which can be an inexpensive and sustainable sources of natural wastes for the energy storage devices, such as supercapacitors. The carbonaceous materials used in this study were carbonized at the temperatures of 700°C and 900°C after the stabilization process at 240°C for two hours. These shells showed approximately 60% carbon yield. Carbonized nutshells were chemically activated using1wt% potassium hydroxide (KOH). Activated carbon powders with polyvinylidene fluoride (PVdF) were used to construct carbon electrodes. A 1M of tetraethylammonium tetrafluoroborate (TEABF4) and propylene carbonate (PC) were used as electrolytes. Electrochemical techniques, such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used for the characterization of the supercapacitors. Scanning electron microscopy (SEM) was used to inspect the surface texture of the activated carbons. Activated pistachio shells carbonized at 700°C showed more porous surface texture than those carbonized at 900°C. Effects of the carbonization temperatures were studied for their electrochemical characteristics. The shells carbonized at 700°C showed better electrochemical characteristics compared to those carbonized at 900°C. The test results provided about 27,083 μF/g specific capacitance at a scan rate of 10mV/s. This study showed promising results for using these activated carbons produced from the natural wastes for supercapacitor applications.

  17. An absolute sensitivity calibration of the JET VUV SPRED spectrometer

    NASA Astrophysics Data System (ADS)

    Lawson, K. D.; Coffey, I. H.; Zacks, J.; Stamp, M. F.; contributors, JET-EFDA

    2009-04-01

    The determination of a good relative and absolute sensitivity calibration for wideband VUV spectrometers is challenging. On JET, the possible T and Be contamination of the VUV spectrometer precludes its removal to a synchrotron source and, consequently, a range of alternative in situ techniques have been investigated in depth. This has resulted in a reliable calibration for the complete spectral range, the relative calibration at short wavelengths being particularly accurate. At these wavelengths, a novel approach is used, in which the calibration is extended using a number of Na- and Li-like metal doublets. At longer wavelengths, the Li-like doublets of Ar and Ne have been used in conjunction with CII, CIII and CIV line intensity ratios. Unexplained discrepancies between the measured and modelled C results have meant that the exceptional short wavelength accuracy has not be repeated at these longer wavelengths. The absolute sensitivity has been determined from branching ratios to an absolutely calibrated visible spectrometer. The long term stability of the calibration is discussed.

  18. Measurement of the absolute gas gain and gain variations study in straw-tube detectors

    NASA Astrophysics Data System (ADS)

    Gianotti, P.; Kashchuk, A.; Levitskaya, O.; Passamonti, L.; Pierluigi, D.; Russo, A.; Savriè, M.

    2013-08-01

    We present the results of the absolute gas gain measurement of a straw drift-tube filled with a binary gaseous mixture Ar-CO2(90-10) at 2 bar absolute pressure. The measurement has been performed using an intense 1.3 GBq 137Cs-source producing the primary ionization current. The results, as a function of the high voltage and gas parameters, were fitted and parameterized with a Diethorn's formula.

  19. The effect of alternating influent carbon source composition on activated sludge bioflocculation.

    PubMed

    Van Dierdonck, J; Van den Broeck, R; Vervoort, E; Van Impe, J; Smets, I

    2013-09-10

    The impact of alternating influent carbon sources, i.e., glucose and starch, on activated sludge bioflocculation was investigated. To this end, four lab-scale reactors were operated during a long-term experiment. During this period the influent carbon source ratio (glucose/starch) was alternated every 7 or 35 days (i.e., a fast and slow switching frequency). Bioflocculation was monitored throughout the entire experiment using an extensive set of parameters, including macroscopic and microscopic activated sludge characteristics. Sludge hydrophobicity remained high (>80%) throughout the experiment indicating good bioflocculation. However, sludge settleability decreased for all four reactors after a 60 day adaptation period to the applied alternation in influent carbon source. During this adaptation period, floc size decreased due to the release of microcolonies. The subsequent period was characterized by a decrease in settleability, coinciding with a release of primary particles and an increase in floc size. The observed phenomena could be linked with the protein concentration near the floc surface. This fraction mainly consists of hydrolytic enzymes necessary for the degradation of starch and is responsible for a progressive deterioration of the EPS matrix. The results of this specific study indicate to be independent of the influent carbon source ratio or switching frequency.

  20. Applicability of light-emitting diodes as light sources for active differential optical absorption spectroscopy measurements

    NASA Astrophysics Data System (ADS)

    Kern, Christoph; Trick, Sebastian; Rippel, Bernhard; Platt, Ulrich

    2006-03-01

    We present what is to our knowledge the first use of light-emitting diodes (LEDs) as light sources for long-path differential optical absorption spectroscopy (LP-DOAS) measurements of trace gases in the open atmosphere. Modern LEDs represent a potentially advantageous alternative to thermal light sources, in particular to xenon arc lamps, which are the most common active DOAS light sources. The radiative properties of a variety of LEDs were characterized, and parameters such as spectral shape, spectral range, spectral stability, and ways in which they can be influenced by environmental factors were analyzed. The spectra of several LEDs were found to contain Fabry-Perot etalon-induced spectral structures that interfered with the DOAS evaluation, in particular when a constant temperature was not maintained. It was shown that LEDs can be used successfully as light sources in active DOAS experiments that measure NO2 and NO3 near 450 and 630 nm, respectively. Average detection limits of 0.3 parts in 109 and 16 parts in 1012 respectively, were obtained by use of a 6 km light path in the open atmosphere.

  1. Optical and Radio Properties of QSOS as a Function of Absolute Luminosity.

    NASA Astrophysics Data System (ADS)

    Pica, Andrew Joseph

    1982-03-01

    Photometric data for nearly 250 quasars, BL Lacertids, and active galaxies have been obtained at the Rosemary Hill Observatory during a continuous 13-year monitoring program. Long-term optical records for 130 of these sources are employed in an effort to assess the physical and cosmological properties of quasi-stellar objects. Photographic P and B magnitudes were obtained with the 76- and 46-cm telescopes at Rosemary Hill. Corrections for galactic absorption, emission lines, and the K-term are applied to the raw data yielding monochromatic flux densities at a standard emitted wavelength of 2500 (ANGSTROM). Long -term light curves are compiled for all objects and 3 levels of activity are determined for each individual source. The MEAN, BASE, and MAX brightness levels are then used to study QSOs in their average, quiescent, and active phases, respectively. Absolute intrinsic luminosities of all sources in the sample are computed from the monochromatic flux densities based on relativistic cosmological models. Radio -emitting quasars, radio-quiet QSOs, and active galaxies fall into 3 distinct groups and are examined separately. The cosmological properties of QSOs are studied by plotting apparent magnitude vs. redshift, the so-called Hubble diagram. Scatter in the diagram due to variability is substantially reduced by plotting log z vs. the MEAN, BASE, and MAX flux densities. The brightest QSOs at each redshift are then chosen as "standard candles" in an effort to determine if quasars obey Hubble's law for expanding universe. It is found that they fit the Hubble relation quite well if certain selection effects are accounted for. Other evidence for the cosmological origin of QSOs is briefly discussed. Variability provides a test as to whether individual quasars are essentially multiple in nature (the "Christmas Tree" model), or are single coherent sources (such as a massive black hole). The amplitude of variability vs. absolute luminosity relation is used to discriminate

  2. Modeling and analysis of secondary sources coupling for active sound field reduction in confined spaces

    NASA Astrophysics Data System (ADS)

    Montazeri, Allahyar; Taylor, C. James

    2017-10-01

    This article addresses the coupling of acoustic secondary sources in a confined space in a sound field reduction framework. By considering the coupling of sources in a rectangular enclosure, the set of coupled equations governing its acoustical behavior are solved. The model obtained in this way is used to analyze the behavior of multi-input multi-output (MIMO) active sound field control (ASC) systems, where the coupling of sources cannot be neglected. In particular, the article develops the analytical results to analyze the effect of coupling of an array of secondary sources on the sound pressure levels inside an enclosure, when an array of microphones is used to capture the acoustic characteristics of the enclosure. The results are supported by extensive numerical simulations showing how coupling of loudspeakers through acoustic modes of the enclosure will change the strength and hence the driving voltage signal applied to the secondary loudspeakers. The practical significance of this model is to provide a better insight on the performance of the sound reproduction/reduction systems in confined spaces when an array of loudspeakers and microphones are placed in a fraction of wavelength of the excitation signal to reduce/reproduce the sound field. This is of particular importance because the interaction of different sources affects their radiation impedance depending on the electromechanical properties of the loudspeakers.

  3. Renal arterial embolization with absolute ethanol.

    PubMed Central

    Park, J. H.; Kim, W. S.; Han, M. C.; Lee, C. W.

    1987-01-01

    Twenty separate infarction procedures with absolute ethanol were performed on eighteen renal tumors in seventeen patients at Department of Radiology, Seoul National University Hospital since 1982. Fifteen were hypernephroma cases and two were angiomyolipoma cases. The indications for renal infarction were the preoperative interruption of renal arterial flow in eight cases of hypernephroma, and primary therapy or palliation of symptoms in seven cases of hypernephroma and two cases of angiomyolipoma. Average 15ml of absolute ethanol was injected for renal arterial embolization at a rate of 1-2 ml/sec via balloon occlusion catheter or superselective administration technique. Though the long-term beneficial effect on survival was not confirmed, transcatheter embolization with absolute ethanol was suggested to be used as indispensible treatment in preoperative and inoperable or symptomatic cases of renal tumor. PMID:3269241

  4. Quantitative standards for absolute linguistic universals.

    PubMed

    Piantadosi, Steven T; Gibson, Edward

    2014-01-01

    Absolute linguistic universals are often justified by cross-linguistic analysis: If all observed languages exhibit a property, the property is taken to be a likely universal, perhaps specified in the cognitive or linguistic systems of language learners and users. In many cases, these patterns are then taken to motivate linguistic theory. Here, we show that cross-linguistic analysis will very rarely be able to statistically justify absolute, inviolable patterns in language. We formalize two statistical methods--frequentist and Bayesian--and show that in both it is possible to find strict linguistic universals, but that the numbers of independent languages necessary to do so is generally unachievable. This suggests that methods other than typological statistics are necessary to establish absolute properties of human language, and thus that many of the purported universals in linguistics have not received sufficient empirical justification.

  5. Radioactive preparations with high specific activity and gamma-sources on their base

    SciTech Connect

    Chesanov, V.V.; Demchenko, N.F.; Karasev, V.T.

    1993-12-31

    According to expert`s estimations, the following radionuclides and specific activities will be in great demand in the future: cobalt 60 (400-500Ci/g), iridium 192 (500-800 Ci/g), ytterbium 169 (800-1000 Ci/g), thullium 170 (700-800 Ci/g), selenium 75 (500-800 Ci/g), antimony 124 (30-40 Ci/g), and gadolinium 153 (not less than 50 Ci/g). In addition, the Phosphorus 33 radionuclide preparations with specific activity more than 100,000 Ci/g applied in biochemical investigations are in considerable demand. This paper discusses the investigations and developmental results performed with the preparation and sources of the mentioned radionuclides. Applications are also discussed. All medical and industrial sources are safe and reliable and do not contaminate the environment. Due to ISO 2919-80 classification they are assigned to special form substances.

  6. Methodology of selecting the reference source for an active noise control system in a car.

    PubMed

    Dąbrowski, Zbigniew; Stankiewicz, Bartosz

    2013-01-01

    At the end of the 20th century, a significant development in digital technologies of signal processing made it possible to apply active noise control methods in new domains. A proper selection of the reference signal source is a main problem in implementing such systems. This paper presents an estimation method based on an indicator of the coherent power level. It also presents a simple system of active noise control in a car, operating according to the proposed method of optimising the positioning of reference sources. This system makes it possible to considerably increase the comfort of work of drivers in various kinds of road transport without a great increase in cost. This is especially significant in the case of trucks and vans. Passive barriers are considerably more expensive in them, which results in a higher level of noise than in passenger cars.

  7. Transit Use by Children and Adolescents: An Overlooked Source of and Opportunity for Physical Activity?

    PubMed Central

    Durand, Casey P.; Pettee Gabriel, Kelley K.; Hoelscher, Deanna M.; Kohl, Harold W.

    2017-01-01

    Background The potential for adults to accrue significant physical activity through public transit use is a topic of interest. However, there are no data on analogous questions among children. The goal of this analysis was to quantify patterns of transit use and correlates of transit-related physical activity among children aged 5 to 17 years. Methods Data for this cross-sectional study came from the 2012 California Household Travel Survey. Probit regressions modeled the probability of transit use; negative binomial regressions modeled minutes/day in transit-related active travel. Results Public transit use accounted for 3% of trips in California in 2012. Older Hispanic youth and those residing in areas with greater housing density and county size had a higher probability of transit use. Driver licensure, home ownership, household income, and vehicles in household were negatively correlated with public transit use. Race/ethnicity, income, and transit type were correlated with time spent in active travel to/from transit. Conclusions Given its importance as a source of physical activity for some children, researchers should consider assessment of public transit-related activity in physical activity measurement instruments. Efforts to encourage active travel should consider how to incorporate transit-related activity, both from a measurement perspective and as an intervention strategy. PMID:26999722

  8. Transit Use by Children and Adolescents: An Overlooked Source of and Opportunity for Physical Activity?

    PubMed

    Durand, Casey P; Pettee Gabriel, Kelley K; Hoelscher, Deanna M; Kohl, Harold W

    2016-08-01

    The potential for adults to accrue significant physical activity through public transit use is a topic of interest. However, there are no data on analogous questions among children. The goal of this analysis was to quantify patterns of transit use and correlates of transit-related physical activity among children aged 5 to 17 years. Data for this cross-sectional study came from the 2012 California Household Travel Survey. Probit regressions modeled the probability of transit use; negative binomial regressions modeled minutes/day in transit-related active travel. Public transit use accounted for 3% of trips in California in 2012. Older Hispanic youth and those residing in areas with greater housing density and county size had a higher probability of transit use. Driver licensure, home ownership, household income, and vehicles in household were negatively correlated with public transit use. Race/ethnicity, income, and transit type were correlated with time spent in active travel to/ from transit. Given its importance as a source of physical activity for some children, researchers should consider assessment of public transit-related activity in physical activity measurement instruments. Efforts to encourage active travel should consider how to incorporate transit-related activity, both from a measurement perspective and as an intervention strategy.

  9. The SPARX Project: R & D Activity Towards X-Rays FEL Sources

    SciTech Connect

    Alesini, D.; Bellaveglia, M.; Bertolucci, S.; Biagini, M.E.; Boni, R.; Boscolo, M.; Castellano, M.; Clozza, A.; Di Pirro, G.; Drago, A.; Esposito, A.; Ferrario, M.; Filippetto, D.; Fusco, V.; Gallo, A.; Ghigo, A.; Guiducci, S.; Incurvati, M.; Ligi, C.; Marcellini, F.; Migliorati, M.; /Frascati /ENEA, Frascati /INFN, Milan /INFN, Rome /INFN, Rome2 /Milan Polytechnic /UCLA /SLAC

    2005-08-05

    SPARX is an evolutionary project proposed by a collaboration among ENEA-INFN-CNR-Universita di Roma Tor Vergata aiming at the construction of a FELSASE X-ray source in the Tor Vergata Campus. The first phase of the SPARX project, funded by Government Agencies, will be focused on R&D activity on critical components and techniques for future X-ray facilities as described in this paper.

  10. Lens transmission measurement for an absolute radiation thermometer

    SciTech Connect

    Hao, X.; Yuan, Z.; Lu, X.

    2013-09-11

    The lens transmission for the National Institute of Metrology of China absolute radiation thermometer is measured by a hybrid method. The results of the lens transmission measurements are 99.002% and 86.792% for filter radiometers with center wavelengths 633 nm and 900 nm, respectively. These results, after correcting for diffraction factors and the size-of-source effect when the lens is incorporated within the radiometer, can be used for measurement of thermodynamic temperature. The expanded uncertainty of the lens transmission measurement system has been evaluated. It is 1.3×10{sup −3} at 633 nm and 900 nm, respectively.

  11. Absolute Photoionization Cross Sections of Two Cyclic Ketones: Cyclopentanone & Cyclohexanone.

    PubMed

    Price, Chelsea; Fathi, Yasmin; Meloni, Giovanni

    2017-02-23

    Absolute photoionization cross sections for cyclopentanone and cyclohexanone, as well as partial ionization cross sections for the dissociative ionized fragments, are presented in this investigation. Experiments are performed via a multiplexed photoionization mass spectrometer utilizing VUV synchrotron radiation supplied by the Advanced Light Source of Lawrence Berkeley National Laboratory. These results allow the quantification of these species that is relevant to investigate the kinetics and combustion reactions of potential biofuels. The CBS-QB3 calculated values for the adiabatic ionization energies agree well with the experimental values and the identification of possible dissociative fragments is discussed for both systems.

  12. Absolute linearity measurement of photodetectors using sinusoidal modulated radiation.

    PubMed

    Refaat, Tamer F; Johnson, David G

    2012-07-01

    A method is presented for characterizing the linearity of photodetectors based on time-domain analysis of response to sinusoidal excitation. Nonlinearity is quantified solely from the output distortion. Relative response is converted to absolute response by including two calibration points. For low signal level, one calibration point is required, while using dark current as the second point. The response is mapped over a wider range using a series of overlapping sinusoids for calibration transfer. The method is demonstrated with a relatively linear photodiode and a nonlinear phototransistor. A Michelson interferometer is used to generate sinusoidal modulation of a laser source. Results demonstrate the potential of the proposed technique.

  13. 26 CFR 1.863-8 - Source of income derived from space and ocean activity under section 863(d).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 9 2014-04-01 2014-04-01 false Source of income derived from space and ocean... to Taxable Years Prior to December 30, 1996 § 1.863-8 Source of income derived from space and ocean... space and ocean activity (space and ocean income) is sourced under the rules of this section...

  14. 26 CFR 1.863-8 - Source of income derived from space and ocean activity under section 863(d).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 9 2012-04-01 2012-04-01 false Source of income derived from space and ocean... to Taxable Years Prior to December 30, 1996 § 1.863-8 Source of income derived from space and ocean... space and ocean activity (space and ocean income) is sourced under the rules of this section...

  15. 26 CFR 1.863-8 - Source of income derived from space and ocean activity under section 863(d).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 9 2011-04-01 2011-04-01 false Source of income derived from space and ocean... to Taxable Years Prior to December 30, 1996 § 1.863-8 Source of income derived from space and ocean... space and ocean activity (space and ocean income) is sourced under the rules of this section...

  16. 26 CFR 1.863-8 - Source of income derived from space and ocean activity under section 863(d).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 9 2013-04-01 2013-04-01 false Source of income derived from space and ocean... to Taxable Years Prior to December 30, 1996 § 1.863-8 Source of income derived from space and ocean... space and ocean activity (space and ocean income) is sourced under the rules of this section...

  17. Absolute proper motions of distant Galactic satellites

    NASA Technical Reports Server (NTRS)

    Majewski, S. R.; Cudworth, K. M.

    1993-01-01

    We describe the motivation for a new program to determine the absolute proper motions (transverse velocities) for distant Galactic globular clusters and satellite dwarf spheroidal galaxies. The topic of globular-cluster proper motions is reviewed with emphasis on the correction from relative to absolute proper motions. Our project relies on astrometry from deep 2-5 m prime focus plates which contain images of numerous faint galaxies which are used to set a precise extragalactic reference frame. We discuss first results from the survey, determinations of the space motions for the clusters Palomar 5 and Palomar 3, at distances of 21 and 88 kpc, respectively.

  18. Sensitivity optimization of active filters containing current conveyors and controlled sources

    NASA Astrophysics Data System (ADS)

    Dunning-Davies, J.; Stephenson, F. W.

    1980-03-01

    Employing a technique associated with optimization problems, a minimum sensitivity solution is obtained for a third-order active filter containing a current conveyor. This solution is given in terms of the time constants for the circuit. Further investigation yields a solution in terms of the resistors and capacitors which, as well as being one of minimum sensitivity, is such that the resistor sum and spread and capacitor sum and spread are all small. Similar results are presented for a third-order active filter containing a controlled source.

  19. Cellular mechanisms of high frequency oscillations in epilepsy: on the diverse sources of pathological activities.

    PubMed

    Menendez de la Prida, Liset; Trevelyan, Andrew J

    2011-12-01

    A major goal in epilepsy research is to understand the cellular basis of pathological forms of network oscillations, particularly those classified as high-frequency activity. What are the underlying mechanisms, and how do they arise? The topic of this review is the pattern of high-frequency oscillations that have been recorded in epileptic tissue, and how they might differ from physiological activity. We discuss recent experimental and clinical data with a major focus on the diverse sources of extracellular signals and the contribution of different neuronal populations, including GABAergic interneurons and glutamatergic principal cells. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Activity patterns of Californians: Use of and proximity to indoor pollutant sources

    NASA Astrophysics Data System (ADS)

    Jenkins, Peggy L.; Phillips, Thomas J.; Mulberg, Elliot J.; Hui, Steve P.

    The California Air Resources Board funded a statewide survey of activity patterns of Californians over 11 years of age in order to improve the accuracy of exposure assessments for air pollutants. Telephone interviews were conducted with 1762 respondents over the four seasons from fall 1987 through summer 1988. In addition to completing a 24-h recall diary of activities and locations, participants also responded to questions about their use of and proximity to potential pollutant sources. Results are presented regarding time spent by Californians in different activities and locations relevant to pollutant exposure, and their frequency of use of or proximity to pollutant sources including cigarettes, consumer products such as paints and deodorizers, combustion appliances and motor vehicles. The results show that Californians spend, on average, 87% of their time indoors, 7% in enclosed transit and 6% outdoors. At least 62% of the population over 11 years of age and 46% of nonsmokers are near others' tobacco smoke at some time during the day. Potential exposure to different pollutant sources appears to vary among different gender and age groups. For example, women are more likely to use or be near personal care products and household cleaning agents, while men are more likely to be exposed to environmental tobacco smoke, solvents and paints. Data from this study can be used to reduce significantly the uncertainty associated with risk assessments for many pollutants.

  1. [Amphibian skin secretions as a new source of antibiotics and biologically active substances].

    PubMed

    Całkosiński, Ireneusz; Zasadowski, Arkadiusz; Bronowicka-Szydełko, Agnieszka; Dzierzba, Katarzyna; Seweryn, Ewa; Dobrzyński, Maciej; Gamian, Andrzej

    2009-11-12

    So far, the main sources of biologically active substances used in medicine have been plants, molds, and propolis. The obtained compounds have either therapeutic features or require additional modification. They are sometimes combined with other pharmacological substances to intensify their therapeutic effect. However, the effectiveness of many drugs has been rapidly decreasing.The overuse of antibiotics in the treatment and prophylaxis of human infections (especially in hospitals) as well as their widespread and often unjustified use in the treatment and prophylaxis of farm animal illnesses contribute to the development of a variety of resistance mechanisms by microorganisms. Because of the increasing ineffectiveness of antibiotics used so far and difficulties in obtaining new drugs, it is necessary to find new sources of these compounds, for example in animal organisms. Research has demonstrated that amphibian skin secretions are rich in a variety of active substances which have strong pharmacological properties. In these compounds we can distinguish, for example, toxins, antimicrobial peptides, opioid peptides, steroids, and alkaloids.These compounds show cytotoxic, antimicrobial, analgesic, anti-inflammatory, and even antiviral activities (including anti-HIV). These substances can be used in cell receptor studies and in transmembrane ion transport analysis. Because these compounds are secreted by skin glands,they can be easy obtained without injuring these animals. It is probable that amphibian skin constitutes a potential source of modern drugs.

  2. Pattern reactivation co-varies with activity in the core recollection network during source memory.

    PubMed

    Leiker, Emily K; Johnson, Jeffrey D

    2015-08-01

    Neuroimaging studies of episodic memory have consistently demonstrated that memory retrieval involves reactivating patterns of neural activity that were present during encoding, and these effects are thought to reflect the qualitative retrieval (recollection) of information that is specific to the content of an episode. By contrast, recollection is also accompanied by other neural correlates that generalize across episodic content and are consequently referred to as the "core recollection network". The neural mechanism by which these specific and core effects interact to give rise to episodic memory retrieval is largely unknown. The current study addressed this issue by testing for correlations (connectivity) between pattern reactivation and activity in the core recollection network. Subjects encoded a series of words with different tasks and then completed a two-step source memory test, whereby they identified the task (source) previously associated with the word and the confidence of that judgment. Multivariate pattern analysis (MVPA) was used in combination with fMRI to first identify encoding-related neural patterns and then test for their reactivation during retrieval. Consistent with prior findings, the magnitude of reactivation increased with source-memory confidence. Moreover, individual-trial measures of reactivation exhibited positive correlations with activity in multiple regions of the core recollection network. Importantly, evidence of functional connectivity between pattern reactivation and a region of left posterior parietal cortex supports the role of this region in tracking the retrieval of episodic information in service of making subjective memory decisions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Bayesian Inference for Neural Electromagnetic Source Localization: Analysis of MEG Visual Evoked Activity

    SciTech Connect

    George, J.S.; Schmidt, D.M.; Wood, C.C.

    1999-02-01

    We have developed a Bayesian approach to the analysis of neural electromagnetic (MEG/EEG) data that can incorporate or fuse information from other imaging modalities and addresses the ill-posed inverse problem by sarnpliig the many different solutions which could have produced the given data. From these samples one can draw probabilistic inferences about regions of activation. Our source model assumes a variable number of variable size cortical regions of stimulus-correlated activity. An active region consists of locations on the cortical surf ace, within a sphere centered on some location in cortex. The number and radi of active regions can vary to defined maximum values. The goal of the analysis is to determine the posterior probability distribution for the set of parameters that govern the number, location, and extent of active regions. Markov Chain Monte Carlo is used to generate a large sample of sets of parameters distributed according to the posterior distribution. This sample is representative of the many different source distributions that could account for given data, and allows identification of probable (i.e. consistent) features across solutions. Examples of the use of this analysis technique with both simulated and empirical MEG data are presented.

  4. Prefrontal cortex activity associated with source monitoring in a working memory task.

    PubMed

    Mitchell, Karen J; Johnson, Marcia K; Raye, Carol L; Greene, Erich J

    2004-01-01

    Using functional magnetic resonance imaging (fMRI), we investigated prefrontal cortex (PFC) activity during remembering specific source information (format, location judgments) versus remembering that could be based on undifferentiated information, such as familiarity (old/new recognition [ON], recency judgments). A working memory (WM) paradigm with an immediate test yielded greater activation in the lateral PFC for format and location source memory (SM) tasks than ON recognition; this SM-related activity was left lateralized. The same regions of PFC were recruited in Experiment 2 when information was tested immediately and after a filled delay. Substituting recency for location judgments (Experiment 3) resulted in an overall shift in task context that produced greater right PFC activity associated with ON and recency tasks compared to the format task, in addition to left SM-related activity. These data extend to WM previous findings from long-term memory (LTM) indicating that the left and right PFC may be differentially involved in memory attributions depending on the specificity of information evaluated. The findings also provide evidence for the continuity of evaluative processes recruited in WM and LTM.

  5. Bayesian inference for neural electromagnetic source localization: analysis of MEG visual evoked activity

    NASA Astrophysics Data System (ADS)

    Schmidt, David M.; George, John S.; Wood, C. C.

    1999-05-01

    We have developed a Bayesian approach to the analysis of neural electromagnetic (MEG/EEG) data that can incorporate or fuse information from other imaging modalities and addresses the ill-posed inverse problem by sampling the many different solutions which could have produced the given data. From these samples one can draw probabilistic inferences about regions of activation. Our source model assumes a variable number of variable size cortical regions of stimulus-correlated activity. An active region consists of locations on the cortical surface, within a sphere centered on some location in cortex. The number and radii of active regions can vary to defined maximum values. The goal of the analysis is to determine the posterior probability distribution for the set of parameters that govern the number, location, and extent of active regions. Markov Chain Monte Carlo is used to generate a large sample of sets of parameters distributed according to the posterior distribution. This sample is representative of the many different source distributions that could account for given data, and allows identification of probable (i.e. consistent) features across solutions. Examples of the use of this analysis technique with both simulated and empirical MEG data are presented.

  6. Development of the activation analysis calculational methodology for the Spallation Neutron Source (SNS)

    SciTech Connect

    Odano, N.; Johnson, J.O.; Charton, L.A.; Barnes, J.M.

    1998-03-01

    For the design of the proposed Spallation Neutron Source (SNS), activation analyses are required to determine the radioactive waste streams, on-line material processing requirements remote handling/maintenance requirements, potential site contamination and background radiation levels. For the conceptual design of the SNS, the activation analyses were carried out using the high-energy transport code HETC96 coupled with MCNP to generate the required nuclide production rates for the ORIHET95 isotope generation code. ORIHET95 utilizes a matrix-exponential method to study the buildup and decay of activities for any system for which the nuclide production rates are known. In this paper, details of the developed methodology adopted for the activation analyses in the conceptual design of the SNS are presented along with some typical results of the analyses.

  7. Effects of light sources and visible light-activated titanium dioxide photocatalyst on bleaching.

    PubMed

    Suyama, Yuji; Otsuki, Masayuki; Ogisu, Shinichiro; Kishikawa, Ryuzo; Tagami, Junji; Ikeda, Masaomi; Kurata, Hiroshi; Cho, Takahiro

    2009-11-01

    The objective of this study was to evaluate, using methylene blue (MB), the effects of various light sources on the bleaching action of hydrogen peroxide (H(2)O(2)) with two titanium dioxide (TiO(2)) photocatalysts - an ultraviolet light-activated TiO(2) photocatalyst (UVTiO(2)) versus a visible light-activated TiO(2) photocatalyst (VL-TiO(2)). Five experimental solutions (VL-TiO(2)+H(2)O(2), UV-TiO(2)+H(2)O(2), H(2)O(2), VL-TiO(2), UV-TiO(2)) were prepared by mixing varying concentrations of H(2)O(2 )and/or TiO(2 )photocatalyst with MB solution. For H(2)O(2)-containing solutions (VL-TiO(2)+H(2)O(2), UV-TiO(2)+H(2)O(2), and H(2)O(2)), the concentration of H(2)O(2) was adjusted to 3.5%. For the four different light sources, low- and high-intensity halogen lamps and blue LED LCUs were used. All the experimental solutions were irradiated by each of the light sources for 7 minutes, and the absorbance at 660 nm was measured every 30 seconds to determine the concentration of MB as an indicator of the bleaching effect. On the interaction between the effects of light source and bleaching treatment, the high-intensity halogen with VL-TiO(2)+H(2)O(2) caused the most significant reduction in MB concentration. On the effect of light sources, the halogen lamps resulted in a greater bleaching effect than the blue LED LCUs.

  8. Physical activity and social support in adolescents: analysis of different types and sources of social support.

    PubMed

    Mendonça, Gerfeson; Júnior, José Cazuza de Farias

    2015-01-01

    Little is known about the influence of different types and sources of social support on physical activity in adolescents. The aim of this study was to analyse the association between physical activity and different types and sources of social support in adolescents. The sample consisted of 2,859 adolescents between 14-19 years of age in the city of João Pessoa, in Northeastern Brazil. Physical activity was measured with a questionnaire and social support from parents and friends using a 10-item scale five for each group (type of support: encouragement, joint participation, watching, inviting, positive comments and transportation). Multivariable analysis showed that the types of support provided by parents associated with physical activity in adolescents were encouragement for females (P < 0.001) and adolescents between 14-16 years of age (P = 0.003), and transportation (P = 0.014) and comments (P = 0.037) for males. The types of social support provided by friends were: joint participation in male adolescents (P < 0.001) and in these 17-19-year-olds (P < 0.001), and comments in both genders (males: P = 0.009; females: P < 0.001) and 14-16-year-olds (P < 0.001). We conclude that the type of social support associated with physical activity varies according to its source, as well as the gender and age of the adolescents.

  9. Consistent set of nuclear parameters values for absolute INAA

    SciTech Connect

    Heft, R.E.

    1980-01-01

    Gamma spectral analysis of irradiated material can be used to determine absolute disintegration rates for specific radionuclides. These data, together with measured values for the thermal and epithermal neutron fluxes, and irradiation, cooling and counting time values, are all the experimental information required to do absolute Instrumental Neutron Activation Analysis. The calculations required to go from product photon emission rate to target nuclide amount depend upon values used for the thermal neutron capture cross-section, the resonance absorption integral, the half-life and photon branching ratios. Values for these parameters were determined by irradiating and analyzing a series of elemental standards. The results of these measurements were combined with values reported by other workers to arrive at a set of recommended values for the constants. Values for 114 nuclides are listed.

  10. Absolute configuration assignment of (+)-fluralaner using vibrational circular dichroism.

    PubMed

    Kong, John; Joyce, Leo A; Liu, Jinchu; Jarrell, Tiffany M; Culberson, J Chris; Sherer, Edward C

    2017-10-05

    The absolute configurations of the separated enantiomers of fluralaner, a racemic animal health product used to prevent fleas and ticks, have been assigned using vibrational circular dichroism (VCD). The crystallographic structure of the active enantiomer (+)-fluralaner has previously been shown to have the (S) configuration using small molecule crystallography. We sought a faster analytical method to determine the absolute configuration of the separated enantiomers. When comparing the measured IR (infrared) and VCD spectra, it is apparent that the amide carbonyl groups appear in the IR but are nearly absent in the VCD. Computational work to calculate the VCD and IR using in vacuo models, implicit solvation, and explicitly solvated complexes has implicated conformational averaging of the carbonyl VCD intensities. © 2017 Wiley Periodicals, Inc.

  11. Absolute configuration of labdane diterpenoids from Physalis nicandroides.

    PubMed

    Maldonado, Emma; Pérez-Castorena, Ana L; Romero, Yunuen; Martínez, Mahinda

    2015-02-27

    A mixture of the new epimeric labdenetriols 1 and 2 was isolated from the aerial parts of Physalis nicandroides. The structures of 1 and 2, including their absolute configurations, were established by analyses of their spectroscopic data, together with the X-ray diffraction analysis of acetonide 3 and chemical correlation with (-)-(13E)-labd-13-ene-8α,15-diol (6), whose absolute configuration was also confirmed by X-ray analysis of its dibromo derivative 7. The epimeric labdenediols 8 and 9, the known labdanes 6 and 11, and the acylsucroses 12 and 13 were also isolated. Labdanes 6 and 11 showed moderate anti-inflammatory activities in the induced ear edema model.

  12. Sources and evolution of cloud-active aerosol in California's Sierra Nevada Mountains

    NASA Astrophysics Data System (ADS)

    Roberts, G. C.; Corrigan, C.; Noblitt, S.; Creamean, J.; Collins, D. B.; Cahill, J. F.; Prather, K. A.; Collett, J. L.; Henry, C.

    2011-12-01

    To assess the sources of cloud-active aerosol and their influence on the hydrological cycle in California, the CalWater Experiment took place in winter 2011 in the foothills of the Sierra Nevada Mountains. During this experiment, we coupled the capabilities of demonstrated miniaturized instrumentation - cloud condensation nuclei (CCN), water condensation nuclei (WCN) and microchip capillary electrophoresis (MCE) - to provide direct chemical measurements of cloud active aerosols. Ion concentrations of CCN droplets attribute the anthropogenic, marine and secondary organic contributions to cloud-active aerosols. Detailed spectra from an Aerosol-Time-of-Flight Mass Spectrometer provide additional information on the sources of aerosol. Storm fronts and changes in atmospheric boundary layer brought aerosol and anions associated with Central Valley pollution to the field site with CCN concentrations reaching several thousand cm-3. Hygroscopicity parameters indicate aging of the organic fraction during aerosol transport from the Central Valley to the mountains. Otherwise, CCN concentrations were low when high pressure systems prevented boundary layer development and intrusion of the Central Valley pollution to the site. MCE results show that nitrates and sulfates comprise most of the fraction of the aerosol anion mass (PM1). During the passage of storm fronts, which transported pollution from the Central Valley upslope, nitrate concentrations peaked at several μ g m-3. Low supersaturation CCN concentrations coincide with increases in aerosol nitrate, which suggests that nitrate has a role in cloud formation of giant CCN and, furthermore, in precipitation processes in the Sierra Nevada. CCN spectra show large variations depending on the aerosol sources and sometimes exhibit bi-modal distributions with minima at 0.3% Sc -- similar to the so-called 'Hoppel minima' associated to number size distributions. During these bi-modal events, sulfate also increases supporting the

  13. 40 CFR Table 3 to Part 455 - Organic Pesticide Active Ingredient New Source Performance Standards (NSPS) and Pretreatment...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Organic Pesticide Active Ingredient... STANDARDS PESTICIDE CHEMICALS Pt. 455, Table 3 Table 3 to Part 455—Organic Pesticide Active Ingredient New Source Performance Standards (NSPS) and Pretreatment Standards for New Sources (PSNS) Pesticide kg/kkg...

  14. 40 CFR Table 3 to Part 455 - Organic Pesticide Active Ingredient New Source Performance Standards (NSPS) and Pretreatment...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Organic Pesticide Active Ingredient... STANDARDS PESTICIDE CHEMICALS Pt. 455, Table 3 Table 3 to Part 455—Organic Pesticide Active Ingredient New Source Performance Standards (NSPS) and Pretreatment Standards for New Sources (PSNS) Pesticide kg/kkg...

  15. An Absolute Electrometer for the Physics Laboratory

    ERIC Educational Resources Information Center

    Straulino, S.; Cartacci, A.

    2009-01-01

    A low-cost, easy-to-use absolute electrometer is presented: two thin metallic plates and an electronic balance, usually available in a laboratory, are used. We report on the very good performance of the device that allows precise measurements of the force acting between two charged plates. (Contains 5 footnotes, 2 tables, and 6 figures.)

  16. Stimulus Probability Effects in Absolute Identification

    ERIC Educational Resources Information Center

    Kent, Christopher; Lamberts, Koen

    2016-01-01

    This study investigated the effect of stimulus presentation probability on accuracy and response times in an absolute identification task. Three schedules of presentation were used to investigate the interaction between presentation probability and stimulus position within the set. Data from individual participants indicated strong effects of…

  17. An Absolute Electrometer for the Physics Laboratory

    ERIC Educational Resources Information Center

    Straulino, S.; Cartacci, A.

    2009-01-01

    A low-cost, easy-to-use absolute electrometer is presented: two thin metallic plates and an electronic balance, usually available in a laboratory, are used. We report on the very good performance of the device that allows precise measurements of the force acting between two charged plates. (Contains 5 footnotes, 2 tables, and 6 figures.)

  18. Unified Absolute Spectrophotometry for Star Clusters

    NASA Astrophysics Data System (ADS)

    Dodd, R. J.

    2007-04-01

    Uniform, dereddened, absolute, flux density versus frequency, low-resolution spectra were constructed for stars in star clusters. Photometric and spectrophotometric observations were extracted from printed papers, catalogues, and on-line databases, for ten stars selected, on the basis of their positions, proper motion components and photometry, as members of the young open cluster IC2391. The units of measurement used in the original publication were converted, where necessary, to apparent flux densities in Janskys and frequencies in Hertz. Given measured values for interstellar extinction and distances to the stars, absolute flux densities at the standard 10pc distance were readily computed from the apparent values. Plots were prepared for each of the member stars showing the mean frequency, the bandwidth, the absolute monochromatic flux density and a total error estimation, where possible, for each observed passband. Absolute spectrophotometry for Vega from Hubble Space Telescope observations is also shown on each plot to serve as a reference. The difficulties experienced in producing the plots are discussed and ways in which these may be ameliorated are suggested.

  19. Comparative vs. Absolute Judgments of Trait Desirability

    ERIC Educational Resources Information Center

    Hofstee, Willem K. B.

    1970-01-01

    Reversals of trait desirability are studied. Terms indicating conservativw behavior appeared to be judged relatively desirable in comparative judgement, while traits indicating dynamic and expansive behavior benefited from absolute judgement. The reversal effect was shown to be a general one, i.e. reversals were not dependent upon the specific…

  20. New Techniques for Absolute Gravity Measurements.

    DTIC Science & Technology

    1983-01-07

    Hammond, J.A. (1978) Bollettino Di Geofisica Teorica ed Applicata Vol. XX. 8. Hammond, J. A., and Iliff, R. L. (1979) The AFGL absolute gravity system...International Gravimetric Bureau, No. L:I-43. 7. Hammond. J.A. (1978) Bollettino Di Geofisica Teorica ed Applicata Vol. XX. 8. Hammond, J.A., and

  1. Absolute distance interferometry using diode lasers

    NASA Astrophysics Data System (ADS)

    Meiners-Hagen, K.; Abou-Zeid, A.; Hartmann, L.

    2008-10-01

    An approach to a homodyne absolute distance interferometer (ADI) was previously presented which makes use of two extended cavity diode lasers (ECDL). The length measurement is performed by combining variable synthetic wavelength interferometry and two wavelength interferometry in one setup. In this contribution the ADI was compared to a counting HeNe laser interferometer up to a length of 10 m.

  2. Absolute partial photoionization cross sections of ozone.

    SciTech Connect

    Berkowitz, J.; Chemistry

    2008-04-01

    Despite the current concerns about ozone, absolute partial photoionization cross sections for this molecule in the vacuum ultraviolet (valence) region have been unavailable. By eclectic re-evaluation of old/new data and plausible assumptions, such cross sections have been assembled to fill this void.

  3. Stimulus Probability Effects in Absolute Identification

    ERIC Educational Resources Information Center

    Kent, Christopher; Lamberts, Koen

    2016-01-01

    This study investigated the effect of stimulus presentation probability on accuracy and response times in an absolute identification task. Three schedules of presentation were used to investigate the interaction between presentation probability and stimulus position within the set. Data from individual participants indicated strong effects of…

  4. Absolute Positioning Using the Global Positioning System

    DTIC Science & Technology

    1994-04-01

    Global Positioning System ( GPS ) has becom a useful tool In providing relativ survey...Includes the development of a low cost navigator for wheeled vehicles. ABSTRACT The Global Positioning System ( GPS ) has become a useful tool In providing...technique of absolute or point positioning involves the use of a single Global Positioning System ( GPS ) receiver to determine the three-dimenslonal

  5. Redox activity of urban quasi-ultrafine particles from primary and secondary sources

    NASA Astrophysics Data System (ADS)

    Verma, Vishal; Ning, Zhi; Cho, Arthur K.; Schauer, James J.; Shafer, Martin M.; Sioutas, Constantinos

    2009-12-01

    To characterize the redox activity profiles of atmospheric aerosols from primary (traffic) and secondary photochemical sources, ambient quasi-ultrafine particles were collected near downtown Los Angeles in two different time periods - morning (6:00-9:00 PDT) and afternoon (11:00-14:00 PDT) in the summer of 2008. Detailed chemical analysis of the collected samples, including water-soluble elements, inorganic ions, organic species and water soluble organic carbon (WSOC) was conducted and redox activity of the samples was measured by two different assays: the dithiothreitol (DTT) and the macrophage reactive oxygen species (ROS) assays. Tracers of secondary photochemical reactions, such as sulfate and organic acids were higher (2.1 ± 0.6 times for sulfate, and up to 3 times for the organic acids) in the afternoon period. WSOC was also elevated by 2.5 ± 0.9 times in the afternoon period due to photo-oxidation of primary particles during atmospheric aging. Redox activity measured by the DTT assay was considerably higher for the samples collected during the afternoon; on the other hand, diurnal trends in the ROS-based activity were not consistent between the morning and afternoon periods. A linear regression between redox activity and various PM chemical constituents showed that the DTT assay was highly correlated with WSOC ( R2 = 0.80), while ROS activity was associated mostly with water soluble transition metals (Vanadium, Nickel and Cadmium; R2 > 0.70). The DTT and ROS assays, which are based on the generation of different oxidizing species by chemical PM constituents, provide important information for elucidating the health risks related to PM exposure from different sources. Thus, both primary and secondary particles possess high redox activity; however, photochemical transformations of primary emissions with atmospheric aging enhance the toxicological potency of primary particles in terms of generating oxidative stress and leading to subsequent damage in cells.

  6. An Accurate, All-Sky, Absolute, Low-Frequency Flux Density Scale

    NASA Astrophysics Data System (ADS)

    Perley, Richard A.; Callingham, Joseph; Butler, Bryan J.

    2016-01-01

    The spectral flux density scale between 10 and 1000 MHz has never been accurately established. Early works from the 1960s and 1970s differ typically by 5 to 10% or more. The flux density scale proposed by Scaife and Heald (2012) is a reconciliation of these existing scales, applicable to six compact northern sources, but does not include new data, nor does it extend to any southern sources. The situation for southern sources is considerably poorer, as most of the early work was limited to northern sources. The major causes of the discrepancies between proposed scales is in the limited resolution and imaging fidelity of the telescopes utilized. The Jansky Very Large Array has been designed for high linearity, resolution, and imaging fidelity, and is thus ideally suited for making accurate measurements of the flux density ratios between proposed calibrator sources. These ratios can then be placed on an absolute scale through knowedge of the spectrum of one of more of the sources. We report here on the results of two recent programs using the Jansky Very Large Array:1) Establishment of the absolute flux densities of eighteen sources (including seven southern sources) from 75 MHz to 48 GHz (limits vary for each source) using the absolutely-calibrated spectrum of Cygnus A (Baars et al., 1977) for frequencies lower than 1 GHz, and the proposed, absolutely-calibrated scale of Perley and Butler (2013) for frequencies above 1 GHz. 2) Extension of this scale to 30 compact southern sources proposed as calibrators, utilizing 3C48 (whose absolute spectrum is calibrated above) as the standard. Polynomial expressions for the spectra, and images for all objects have been generated and will be available.

  7. Astaxanthin: Sources, Extraction, Stability, Biological Activities and Its Commercial Applications—A Review

    PubMed Central

    Ambati, Ranga Rao; Siew Moi, Phang; Ravi, Sarada; Aswathanarayana, Ravishankar Gokare

    2014-01-01

    There is currently much interest in biological active compounds derived from natural resources, especially compounds that can efficiently act on molecular targets, which are involved in various diseases. Astaxanthin (3,3′-dihydroxy-β, β′-carotene-4,4′-dione) is a xanthophyll carotenoid, contained in Haematococcus pluvialis, Chlorella zofingiensis, Chlorococcum, and Phaffia rhodozyma. It accumulates up to 3.8% on the dry weight basis in H. pluvialis. Our recent published data on astaxanthin extraction, analysis, stability studies, and its biological activities results were added to this review paper. Based on our results and current literature, astaxanthin showed potential biological activity in in vitro and in vivo models. These studies emphasize the influence of astaxanthin and its beneficial effects on the metabolism in animals and humans. Bioavailability of astaxanthin in animals was enhanced after feeding Haematococcus biomass as a source of astaxanthin. Astaxanthin, used as a nutritional supplement, antioxidant and anticancer agent, prevents diabetes, cardiovascular diseases, and neurodegenerative disorders, and also stimulates immunization. Astaxanthin products are used for commercial applications in the dosage forms as tablets, capsules, syrups, oils, soft gels, creams, biomass and granulated powders. Astaxanthin patent applications are available in food, feed and nutraceutical applications. The current review provides up-to-date information on astaxanthin sources, extraction, analysis, stability, biological activities, health benefits and special attention paid to its commercial applications. PMID:24402174

  8. Astaxanthin: sources, extraction, stability, biological activities and its commercial applications--a review.

    PubMed

    Ambati, Ranga Rao; Phang, Siew Moi; Ravi, Sarada; Aswathanarayana, Ravishankar Gokare

    2014-01-07

    There is currently much interest in biological active compounds derived from natural resources, especially compounds that can efficiently act on molecular targets, which are involved in various diseases. Astaxanthin (3,3'-dihydroxy-β, β'-carotene-4,4'-dione) is a xanthophyll carotenoid, contained in Haematococcus pluvialis, Chlorella zofingiensis, Chlorococcum, and Phaffia rhodozyma. It accumulates up to 3.8% on the dry weight basis in H. pluvialis. Our recent published data on astaxanthin extraction, analysis, stability studies, and its biological activities results were added to this review paper. Based on our results and current literature, astaxanthin showed potential biological activity in in vitro and in vivo models. These studies emphasize the influence of astaxanthin and its beneficial effects on the metabolism in animals and humans. Bioavailability of astaxanthin in animals was enhanced after feeding Haematococcus biomass as a source of astaxanthin. Astaxanthin, used as a nutritional supplement, antioxidant and anticancer agent, prevents diabetes, cardiovascular diseases, and neurodegenerative disorders, and also stimulates immunization. Astaxanthin products are used for commercial applications in the dosage forms as tablets, capsules, syrups, oils, soft gels, creams, biomass and granulated powders. Astaxanthin patent applications are available in food, feed and nutraceutical applications. The current review provides up-to-date information on astaxanthin sources, extraction, analysis, stability, biological activities, health benefits and special attention paid to its commercial applications.

  9. In vitro evaluation of Portuguese propolis and floral sources for antiprotozoal, antibacterial and antifungal activity.

    PubMed

    Falcão, Soraia I; Vale, Nuno; Cos, Paul; Gomes, Paula; Freire, Cristina; Maes, Louis; Vilas-Boas, Miguel

    2014-03-01

    Propolis is a beehive product with a very complex chemical composition, used since ancient times in several therapeutic treatments. As a contribution to the improvement of drugs against several tropical diseases caused by protozoa, we screened Portuguese propolis and its potential floral sources Populus x Canadensis and Cistus ladanifer against Plasmodium falciparum, Leishmania infantum, Trypanosoma brucei and Trypanosoma cruzi. The toxicity against MRC-5 fibroblast cells was evaluated to assess selectivity. The in vitro assays were performed following the recommendations of WHO Special Programme for Research and Training in Tropical Diseases (TDR) and revealed moderate activity, with the propolis extracts presenting the relatively highest inhibitory effect against T. brucei. Additionally, the antimicrobial activity against Staphylococcus aureus, Candida albicans, Trichophyton rubrum and Aspergillus fumigatus was also verified with the better results observed against T. rubrum. The quality of the extracts was controlled by evaluating the phenolic content and antioxidant activity. The observed biological activity variations are associated with the variable chemical composition of the propolis and the potential floral sources under study.

  10. Activated sludge is a potential source for production of biodegradable plastics from wastewater.

    PubMed

    Khardenavis, A; Guha, P K; Kumar, M S; Mudliar, S N; Chakrabarti, T

    2005-05-01

    Increased utilization of synthetic plastics caused severe environmental pollution due to their non-biodegradable nature. In the search for environmentally friendly materials to substitute for conventional plastics, different biodegradable plastics have been developed by microbial fermentations. However, limitations of these materials still exist due to high cost. This study aims at minimization of cost for the production of biodegradable plastics P(3HB) and minimization of environmental pollution. The waste biological sludge generated at wastewater treatment plants is used for the production of P(3HB) and wastewater is used as carbon source. Activated sludge was induced by controlling the carbon: nitrogen ratio to accumulate storage polymer. Initially polymer accumulation was studied by using different carbon and nitrogen sources. Maximum accumulation of polymer was observed with carbon source acetic acid and diammonium hydrogen phosphate (DAHP) as nitrogen source. Further studies were carried out to optimize the carbon: nitrogen ratios using acetic acid and DAHP. A maximum of 65.84% (w/w) P(3HB) production was obtained at C/N ratio of 50 within 96 hours of incubation.

  11. A Multi-Objective Optimization for Performance Improvement of the Z-Source Active Power Filter

    NASA Astrophysics Data System (ADS)

    Hosseini, Seyed Mohsen; Beromi, Yousef Alinejad

    2016-09-01

    The high power dissipation is one of the most important problems of the z-source inverter (ZSI). By using an appropriate optimization scheme, the losses can be significantly reduced without any negative impact on the other characteristics of the inverter. In this paper, a multi-objective optimization is implemented in order to reduce the ZSI total losses as well as to improve the z-source active power filter (APF) performance. The optimization is focused on the four important objectives including power losses of the Z-source APF, the initial cost of the system components, the voltage and current ripples, and the boost factor of the z-source network. For these purposes, the multi-objective genetic algorithm (MOGA) is employed. The numerical and simulation results are presented to evaluate the optimization performance. The results show that a good balance can be achieved between the switching power losses, the voltage-current ripple levels, the component costs and the boost factor using the optimized parameters.

  12. Determining minimum alarm activities of orphan sources in scrap loads; Monte Carlo simulations, validated with measurements

    NASA Astrophysics Data System (ADS)

    Takoudis, G.; Xanthos, S.; Clouvas, A.; Potiriadis, C.

    2010-02-01

    Portal monitoring radiation detectors are commonly used by steel industries in the probing and detection of radioactivity contamination in scrap metal. These portal monitors typically consist of polystyrene or polyvinyltoluene (PVT) plastic scintillating detectors, one or more photomultiplier tubes (PMT), an electronic circuit, a controller that handles data output and manipulation linking the system to a display or a computer with appropriate software and usually, a light guide. Such a portal used by the steel industry was opened and all principal materials were simulated using a Monte Carlo simulation tool (MCNP4C2). Various source-detector configurations were simulated and validated by comparison with corresponding measurements. Subsequently an experiment with a uniform cargo along with two sets of experiments with different scrap loads and radioactive sources ( 137Cs, 152Eu) were performed and simulated. Simulated and measured results suggested that the nature of scrap is crucial when simulating scrap load-detector experiments. Using the same simulating configuration, a series of runs were performed in order to estimate minimum alarm activities for 137Cs, 60Co and 192Ir sources for various simulated scrap densities. The minimum alarm activities as well as the positions in which they were recorded are presented and discussed.

  13. Active control of aircraft engine inlet noise using compact sound sources and distributed error sensors

    NASA Technical Reports Server (NTRS)

    Burdisso, Ricardo (Inventor); Fuller, Chris R. (Inventor); O'Brien, Walter F. (Inventor); Thomas, Russell H. (Inventor); Dungan, Mary E. (Inventor)

    1996-01-01

    An active noise control system using a compact sound source is effective to reduce aircraft engine duct noise. The fan noise from a turbofan engine is controlled using an adaptive filtered-x LMS algorithm. Single multi channel control systems are used to control the fan blade passage frequency (BPF) tone and the BPF tone and the first harmonic of the BPF tone for a plane wave excitation. A multi channel control system is used to control any spinning mode. The multi channel control system to control both fan tones and a high pressure compressor BPF tone simultaneously. In order to make active control of turbofan inlet noise a viable technology, a compact sound source is employed to generate the control field. This control field sound source consists of an array of identical thin, cylindrically curved panels with an inner radius of curvature corresponding to that of the engine inlet. These panels are flush mounted inside the inlet duct and sealed on all edges to prevent leakage around the panel and to minimize the aerodynamic losses created by the addition of the panels. Each panel is driven by one or more piezoelectric force transducers mounted on the surface of the panel. The response of the panel to excitation is maximized when it is driven at its resonance; therefore, the panel is designed such that its fundamental frequency is near the tone to be canceled, typically 2000-4000 Hz.

  14. Active control of aircraft engine inlet noise using compact sound sources and distributed error sensors

    NASA Technical Reports Server (NTRS)

    Burdisso, Ricardo (Inventor); Fuller, Chris R. (Inventor); O'Brien, Walter F. (Inventor); Thomas, Russell H. (Inventor); Dungan, Mary E. (Inventor)

    1994-01-01

    An active noise control system using a compact sound source is effective to reduce aircraft engine duct noise. The fan noise from a turbofan engine is controlled using an adaptive filtered-x LMS algorithm. Single multi channel control systems are used to control the fan blade passage frequency (BPF) tone and the BPF tone and the first harmonic of the BPF tone for a plane wave excitation. A multi channel control system is used to control any spinning mode. The multi channel control system to control both fan tones and a high pressure compressor BPF tone simultaneously. In order to make active control of turbofan inlet noise a viable technology, a compact sound source is employed to generate the control field. This control field sound source consists of an array of identical thin, cylindrically curved panels with an inner radius of curvature corresponding to that of the engine inlet. These panels are flush mounted inside the inlet duct and sealed on all edges to prevent leakage around the panel and to minimize the aerodynamic losses created by the addition of the panels. Each panel is driven by one or more piezoelectric force transducers mounted on the surface of the panel. The response of the panel to excitation is maximized when it is driven at its resonance; therefore, the panel is designed such that its fundamental frequency is near the tone to be canceled, typically 2000-4000 Hz.

  15. Different categories of living and non-living sound-sources activate distinct cortical networks

    PubMed Central

    Engel, Lauren R.; Frum, Chris; Puce, Aina; Walker, Nathan A.; Lewis, James W.

    2009-01-01

    With regard to hearing perception, it remains unclear as to whether, or the extent to which, different conceptual categories of real-world sounds and related categorical knowledge are differentially represented in the brain. Semantic knowledge representations are reported to include the major divisions of living versus non-living things, plus more specific categories including animals, tools, biological motion, faces, and places—categories typically defined by their characteristic visual features. Here, we used functional magnetic resonance imaging (fMRI) to identify brain regions showing preferential activity to four categories of action sounds, which included non-vocal human and animal actions (living), plus mechanical and environmental sound-producing actions (non-living). The results showed a striking antero-posterior division in cortical representations for sounds produced by living versus non-living sources. Additionally, there were several significant differences by category, depending on whether the task was category-specific (e.g. human or not) versus non-specific (detect end-of-sound). In general, (1) human-produced sounds yielded robust activation in the bilateral posterior superior temporal sulci independent of task. Task demands modulated activation of left-lateralized fronto-parietal regions, bilateral insular cortices, and subcortical regions previously implicated in observation-execution matching, consistent with “embodied” and mirror-neuron network representations subserving recognition. (2) Animal action sounds preferentially activated the bilateral posterior insulae. (3) Mechanical sounds activated the anterior superior temporal gyri and parahippocampal cortices. (4) Environmental sounds preferentially activated dorsal occipital and medial parietal cortices. Overall, this multi-level dissociation of networks for preferentially representing distinct sound-source categories provides novel support for grounded cognition models that may

  16. Different categories of living and non-living sound-sources activate distinct cortical networks.

    PubMed

    Engel, Lauren R; Frum, Chris; Puce, Aina; Walker, Nathan A; Lewis, James W

    2009-10-01

    With regard to hearing perception, it remains unclear as to whether, or the extent to which, different conceptual categories of real-world sounds and related categorical knowledge are differentially represented in the brain. Semantic knowledge representations are reported to include the major divisions of living versus non-living things, plus more specific categories including animals, tools, biological motion, faces, and places-categories typically defined by their characteristic visual features. Here, we used functional magnetic resonance imaging (fMRI) to identify brain regions showing preferential activity to four categories of action sounds, which included non-vocal human and animal actions (living), plus mechanical and environmental sound-producing actions (non-living). The results showed a striking antero-posterior division in cortical representations for sounds produced by living versus non-living sources. Additionally, there were several significant differences by category, depending on whether the task was category-specific (e.g. human or not) versus non-specific (detect end-of-sound). In general, (1) human-produced sounds yielded robust activation in the bilateral posterior superior temporal sulci independent of task. Task demands modulated activation of left lateralized fronto-parietal regions, bilateral insular cortices, and sub-cortical regions previously implicated in observation-execution matching, consistent with "embodied" and mirror-neuron network representations subserving recognition. (2) Animal action sounds preferentially activated the bilateral posterior insulae. (3) Mechanical sounds activated the anterior superior temporal gyri and parahippocampal cortices. (4) Environmental sounds preferentially activated dorsal occipital and medial parietal cortices. Overall, this multi-level dissociation of networks for preferentially representing distinct sound-source categories provides novel support for grounded cognition models that may underlie

  17. Correlations between 21-cm radiation and the cosmic microwave background from active sources

    NASA Astrophysics Data System (ADS)

    Berndsen, Aaron; Pogosian, Levon; Wyman, Mark

    2010-09-01

    Neutral hydrogen is ubiquitous, absorbing and emitting 21-cm radiation throughout much of the Universe's history. Active sources of perturbations, such as cosmic strings, would generate simultaneous perturbations in the distribution of neutral hydrogen and in the cosmic microwave background (CMB) radiation from recombination. Moving strings would create wakes leading to 21-cm brightness fluctuations, while also perturbing CMB light via the Gott-Kaiser-Stebbins effect. This would lead to spatial correlations between the 21-cm and CMB anisotropies. Passive sources, like inflationary perturbations, predict no cross-correlations prior to the onset of reionization. Thus, observation of any cross-correlation between CMB and 21-cm radiation from dark ages would constitute evidence for new physics. We calculate the cosmic string-induced correlations between CMB and 21-cm radiation and evaluate their observability.

  18. A high intensity acoustic source for active attenuation of exhaust noise

    NASA Astrophysics Data System (ADS)

    Glendinning, A. G.; Elliott, S. J.; Nelson, P. A.

    1988-04-01

    An electropneumatic sound source was developed for active noise control systems applied in hostile environments such as the exhaust systems of gas turbines and internal combustion engines. It employs a gas bearing to support the friction free motion of a sliding plate which is used to modulate the supply of compressed air. The sliding plate is driven by an electrodynamic vibrator. Experimental results demonstrate that this arrangement reduces harmonic distortion to at least 20 dB below the fundamental driving frequency for most operating conditions. A theoretical analysis of the transducer enables predictions to be made of the acoustic volume velocity (source strength) produced by the transducer as a function of the upstream pressure and displacement of the sliding valve. Applicability of the transducer to gas turbine and internal combustion engine exhaust systems was tested, and net power consumption resulting from the operation of the device was estimated.

  19. Free nitrous acid pretreatment of wasted activated sludge to exploit internal carbon source for enhanced denitrification.

    PubMed

    Ma, Bin; Peng, Yongzhen; Wei, Yan; Li, Baikun; Bao, Peng; Wang, Yayi

    2015-03-01

    Using internal carbon source contained in waste activated sludge (WAS) is beneficial for nitrogen removal from wastewater with low carbon/nitrogen ratio, but it is usually limited by sludge disintegration. This study presented a novel strategy based on free nitrous acid (FNA) pretreatment to intensify the release of organic matters from WAS for enhanced denitrification. During FNA pretreatment, soluble chemical oxygen demand (SCOD) production kept increasing when FNA increased from 0 to 2.04 mg HNO2-N/L. Compared with untreated WAS, the internal carbon source production increased by 50% in a simultaneous fermentation and denitrification reactor fed with WAS pretreated by FNA for 24 h at 2.04 mg HNO2-N/L. This also increased denitrification efficiency by 76% and sludge reduction by 87.5%. More importantly, greenhouse gas nitrous oxide production in denitrification was alleviated since more electrons could be provided by FNA pretreated WAS.

  20. Discrimination of Nuclear Explosions against Civilian Sources Based on Atmospheric Xenon Isotopic Activity Ratios

    NASA Astrophysics Data System (ADS)

    Kalinowski, Martin B.; Axelsson, Anders; Bean, Marc; Blanchard, Xavier; Bowyer, Theodore W.; Brachet, Guy; Hebel, Simon; McIntyre, Justin I.; Peters, Jana; Pistner, Christoph; Raith, Maria; Ringbom, Anders; Saey, Paul R. J.; Schlosser, Clemens; Stocki, Trevor J.; Taffary, Thomas; Kurt Ungar, R.

    2010-05-01

    A global monitoring system for atmospheric xenon radioactivity is being established as part of the International Monitoring System that will verify compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT) once the treaty has entered into force. This paper studies isotopic activity ratios to support the interpretation of observed atmospheric concentrations of 135Xe, 133mXe, 133Xe and 131mXe. The goal is to distinguish nuclear explosion sources from civilian releases. Simulations of nuclear explosions and reactors, empirical data for both test and reactor releases as well as observations by measurement stations of the International Noble Gas Experiment (INGE) are used to provide a proof of concept for the isotopic ratio based method for source discrimination.

  1. Comparison of Plasma Activation of Thin Water Layers by Direct and Remote Plasma Sources

    NASA Astrophysics Data System (ADS)

    Kushner, Mark

    2014-10-01

    Plasma activation of liquids is now being investigated for a variety of biomedical applications. The plasma sources used for this activation can be generally classified as direct (the plasma is in contact with the surface of the liquid) or remote (the plasma does not directly touch the liquid). The direct plasma source may be a dielectric barrier discharge (DBD) where the surface of the liquid is a floating electrode or a plasma jet in which the ionization wave forming the plasma plume reaches the liquid. The remote plasma source may be a DBD with electrodes electrically isolated from the liquid or a plasma jet in which the ionization wave in the plume does not reach the liquid. In this paper, a comparison of activation of thin water layers on top of tissue, as might be encountered in wound healing, will be discussed using results from numerical investigations. We used the modeling platform nonPDPSIM to simulate direct plasma activation of thin water layers using DBDs and remote activation using plasma jets using up to hundreds of pulses. The DBDs are sustained in humid air while the plasma jets consist of He/O2 mixtures flowed into humid air. For similar number of pulses and energy deposition, the direct DBD plasma sources produce more acidification and higher production of nitrates/nitrites in the liquid. This is due to the accumulation of NxOy plasma jets, the convective flow removes many of these species prior to their diffusing into the water or reacting to form higher nitrogen oxides. This latter effect is sensitive to the repetition rate which determines whether reactive species formed during prior pulses overlap with newly produced reactive species. in the gas phase. In the plasma jets, the convective flow removes many of these species prior to their diffusing into the water or reacting to form higher nitrogen oxides. This latter effect is sensitive to the repetition rate which determines whether reactive species formed during prior pulses overlap with

  2. Impact of floral sources and processing on the antimicrobial activities of different unifloral honeys

    PubMed Central

    Elbanna, Khaled; Attalla, Khaled; Elbadry, Medhat; Abdeltawab, Awad; Gamal-Eldin, Hosny; Ramadan, Mohamed Fawzy

    2014-01-01

    Objective To study in vitro antibacterial activity and physicochemical properties of three unifloral honeys (citrus, clover and cotton honeys), and to study the impacts of storage, dilution with water (33%, w/v) and autoclaving (121 °C for 15 min) on honeys characteristics. Methods Honey samples from monofloral sources including citrus (Citrus spp.), Egyptian clover (Trifolium alexandrium) and cotton (Gossypium vitifolium) were obtained during three successive seasons (2010-2012). Physicochemical properties and antimicrobial activities of different honey samples were studies. Results In honey samples stored for 12 or 24 month, colour, hydroxymethyl furfural and acidity increased, while refractive index, water activity, total soluble solids, electrical conductivity and pH remained relatively unaffected, but H2O2 values decreased. Types of honey exhibited various degrees of antibacterial activity against different indicator bacteria, wherein the highest antibacterial activity was recorded for clover honey followed by citrus and cotton honeys, respectively. Different species of bacteria were differed in their sensitivity to honey, wherein Salmonella enteritidis was the most sensitive followed by Staphylococcus aureus, Listeria monocytogenes and Escherichia coli, respectively. Storage up to 24 months at room temperature slightly reduced the antibacterial activity. The reduction levels were about 2.6% and 4.6% after 12 and 24 months, respectively. Diluting honeys with water increased the antibacterial activity by ca. 8.3%, while autoclaving decreased the antibacterial activity by ca. 13.5%. The relative contribution of the peroxide and non-peroxide components in the total antibacterial activity of fresh honeys was investigated. The antibacterial activity of honeys was mainly attributed to non-peroxide antibacterial agents, wherein their contribution was ca. 88%, while the contribution of H2O2 was only 12%. The contribution of the thermostable antibacterial components

  3. Omani propolis: chemical profiling, antibacterial activity and new propolis plant sources

    PubMed Central

    2013-01-01

    Background Propolis (bee glue) is a resinous honeybee product having a long history of application in many countries as a traditional remedy for treating wounds, burns, soar throat, stomach disorders, etc. It has been proved to possess beneficial biological effects, including antimicrobial, antioxidant, anti-inflammatory, cytotoxic, antiulcer, and many others. Bees gather propolis from diverse resinous plant parts and in different phytogeographic regions its chemical composition might vary significantly. In this article we report the results of the first study on the chemical profiles of propolis from Oman, its plant origin and antibacterial activity. Results The chemical profiles of Omani propolis extracts were obtained by GC-MS analysis after silylation. Over 50 individual compounds were identified in the samples, belonging to different compound types: sugars, polyols, hydroxy acids, fatty acids, cardanols and cardols, anacardic acids, flavan derivatives, triterpenes, prenylated flavanones and chalcones. The profiles were dissimilar from other known propolis types. They demonstrate that although Oman is not a large country, the plant sources of propolis vary significantly, even in the same apiary and the same season. Based on chemical profiles, and isolation and identification of major marker compounds (new propolis constituents), new plant sources of propolis were found: Azadiracta indica (neem tree) and Acacia spp. (most probably A. nilotica). The ethanol extracts of the studied propolis samples demonstrated activity against S. aureus (MIC < 100 μg. mL-1) and E. coli (MIC < 380 μg. mL-1). Conclusion Omani propolis is different form the known propolis types and demonstrates significant chemical diversity. Its most important plant source is the resin of Azadirachta indica, and as a result its typical components are С5-prenyl flavanones. Other plant sources have been identified, too, playing some role in resin collection by bees in Oman: Acacia spp

  4. Absolute Calibration of the AXAF Telescope Effective Area

    NASA Technical Reports Server (NTRS)

    Kellogg, E.; Cohen, L.; Edgar, R.; Evans, I.; Freeman, M.; Gaetz, T.; Jerius, D.; McDermott, W. C.; McKinnon, P.; Murray, S.; Podgorski, W.; Schwartz, D.; VanSpeybroeck, L.; Wargelin, B.; Zombeck, M.; Weisskopf, M.; Elsner, R.; ODell, S.; Tennant, A.; Kolodziejczak, J.

    1997-01-01

    The prelaunch calibration of AXAF encompasses many aspects of the telescope. In principle, all that is needed is the complete point response function. This is, however, a function of energy, off-axis angle of the source, and operating mode of the facility. No single measurement would yield the entire result. Also, any calibration made prior to launch will be affected by changes in conditions after launch, such as the change from one g to zero g. The reflectivity of the mirror and perhaps even the detectors can change as well, for example by addition or removal of small amounts of material deposited on their surfaces. In this paper, we give a broad view of the issues in performing such a calibration, and discuss how they are being addressed in prelaunch preparation of AXAF. As our title indicates, we concentrate here on the total throughput of the observatory. This can be thought of as the integral of the point response function, i.e. the encircled energy, out ot the largest practical solid angle for an observation. Since there is no standard x-ray source in the sky whose flux is known to the -1% accuracy we are trying to achieve, we must do this calibration on the ground. we also must provide a means for monitoring any possible changes in this calibration from pre-launch until on-orbit operation can transfer the calibration to a celestial x-ray source whose emission is stable. In this paper, we analyze the elements of the absolute throughput calibration, which we call Effective Area. We review the requirements for calibrations of components or subsystems of the AXAF facility, including mirror, detectors, and gratings. We show how it is necessary to calibrate this ground-based detection system at standard man-made x-ray sources, such as electron storage rings. We present the status of all these calibrations, with indications of the measurements remaining to be done, even though the measurements on the AXAF flight optics and detectors will have been completed by the

  5. Black holes in GRBs, Binary X-ray sources and Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Ruffini, Remo; Patricelli, Barbara; Grazia Bernardini, Maria; Bianco, Carlo Luciano; Caito, Letizia; de Barros, Gustavo; Izzo, Luca

    Gamma Ray Bursts are possibly the most important tools to study the Physics of Black Holes (BHs), evidencing instantaneous BH formation occurring at the highest redshifts. Such pro-cesses of BH formation with distinctive processes of electron-positron pair creation by vacuum polarization are expected to be different from the ones observed in nearby binary X-ray sources (Cygnus X-1, GX 339-4, 4U 1543-47, XTE J1550-564, XTE J1650-500, H 1743-322 and XTE J1859-226). These last ones should in fact originate from precursors activity acting on much longer time scales, due to accretion mechanisms. We have studied high redshift GRB sources within the fireshell model to infer some of the properties of the BHs from which they originate. Here we present, as an example, the analysis of GRB 050904, characterized by a redshift z=6.3 and an isotropic energy release of Eiso = 1.04x1054 ergs, and of GRB090423, characterized by z = 8.1 and Eiso = 3.4x1053 ergs.We have searched for low redshift GRB sources having similar properties: same energetics, similar light curve structure, intense optical emission. The "twin sources" of these two bursts 0.937) and GRB090618 (z = 0.54) respectively. For both pairs of GRBs the numerical simulations that best repr positron plasma originating the GRB, as well as the same comoving spectral energy distribution. However, we h ncbm > .This could indicate that the two sources of each pair have a similar baryon ic progenitor, but occurred in d 109 sola rmasses. A viable approach based on the Dark Matter component versus the baryon ic component are being

  6. Microbial activity and distribution during enhanced contaminant dissolution from a NAPL source zone.

    PubMed

    Amos, Benjamin K; Suchomel, Eric J; Pennell, Kurt D; Löffler, Frank E

    2008-06-01

    Laboratory experiments were conducted to assess microbial reductive dechlorination in one-dimensional sand columns containing a 10 cm long source zone of uniformly distributed residual tetrachloroethene (PCE) nonaqueous phase liquid (NAPL), a 10 cm long transition zone directly down-gradient of the source zone containing some nonuniformly distributed NAPL ganglia, and a 40 cm long plume region down-gradient of the transition zone. The activity and distribution of Sulfurospirillum multivorans, a PCE-to-1,2-cis-dichloroethene (cis-DCE) dechlorinating bacterium, was evaluated in columns containing either a mixed-NAPL (0.25 mol/mol PCE in hexadecane) or pure PCE-NAPL. Significant dechlorination of PCE to cis-DCE was observed in the mixed-NAPL column, resulting in 53% PCE-NAPL mass recovery in the effluent with PCE-NAPL dissolution enhanced by up to 13.6-fold (maximum) and 4.6-fold (cumulative) relative to abiotic dissolution. Quantitative real-time PCR targeting pceA, the PCE reductive dehalogenase gene of S. multivorans, revealed that S. multivorans cells were present in the NAPL source zone, and increased in numbers (i.e., grew) throughout the source and transition zones. In contrast, minimal reductive dechlorination and microbial growth were observed in the column containing pure PCE-NAPL, where aqueous-phase PCE concentrations reached saturation. These results demonstrate that microbial growth within NAPL source zones is possible, provided that contaminant concentrations remain below levels toxic to the dechlorinating organisms, and that microbial growth can result in significant bioenhanced NAPL dissolution.

  7. Luminopsins integrate opto- and chemogenetics by using physical and biological light sources for opsin activation.

    PubMed

    Berglund, Ken; Clissold, Kara; Li, Haofang E; Wen, Lei; Park, Sung Young; Gleixner, Jan; Klein, Marguerita E; Lu, Dongye; Barter, Joseph W; Rossi, Mark A; Augustine, George J; Yin, Henry H; Hochgeschwender, Ute

    2016-01-19

    Luminopsins are fusion proteins of luciferase and opsin that allow interrogation of neuronal circuits at different temporal and spatial resolutions by choosing either extrinsic physical or intrinsic biological light for its activation. Building on previous development of fusions of wild-type Gaussia luciferase with channelrhodopsin, here we expanded the utility of luminopsins by fusing bright Gaussia luciferase variants with either channelrhodopsin to excite neurons (luminescent opsin, LMO) or a proton pump to inhibit neurons (inhibitory LMO, iLMO). These improved LMOs could reliably activate or silence neurons in vitro and in vivo. Expression of the improved LMO in hippocampal circuits not only enabled mapping of synaptic activation of CA1 neurons with fine spatiotemporal resolution but also could drive rhythmic circuit excitation over a large spatiotemporal scale. Furthermore, virus-mediated expression of either LMO or iLMO in the substantia nigra in vivo produced not only the expected bidirectional control of single unit activity but also opposing effects on circling behavior in response to systemic injection of a luciferase substrate. Thus, although preserving the ability to be activated by external light sources, LMOs expand the use of optogenetics by making the same opsins accessible to noninvasive, chemogenetic control, thereby allowing the same probe to manipulate neuronal activity over a range of spatial and temporal scales.

  8. Laterality of brain activity during motor imagery is modulated by the provision of source level neurofeedback.

    PubMed

    Boe, Shaun; Gionfriddo, Alicia; Kraeutner, Sarah; Tremblay, Antoine; Little, Graham; Bardouille, Timothy

    2014-11-01

    Motor imagery (MI) may be effective as an adjunct to physical practice for motor skill acquisition. For example, MI is emerging as an effective treatment in stroke neurorehabilitation. As in physical practice, the repetitive activation of neural pathways during MI can drive short- and long-term brain changes that underlie functional recovery. However, the lack of feedback about MI performance may be a factor limiting its effectiveness. The provision of feedback about MI-related brain activity may overcome this limitation by providing the opportunity for individuals to monitor their own performance of this endogenous process. We completed a controlled study to isolate neurofeedback as the factor driving changes in MI-related brain activity across repeated sessions. Eighteen healthy participants took part in 3 sessions comprised of both actual and imagined performance of a button press task. During MI, participants in the neurofeedback group received source level feedback based on activity from the left and right sensorimotor cortex obtained using magnetoencephalography. Participants in the control group received no neurofeedback. MI-related brain activity increased in the sensorimotor cortex contralateral to the imagined movement across sessions in the neurofeedback group, but not in controls. Task performance improved across sessions but did not differ between groups. Our results indicate that the provision of neurofeedback during MI allows healthy individuals to modulate regional brain activity. This finding has the potential to improve the effectiveness of MI as a tool in neurorehabilitation.

  9. Luminopsins integrate opto- and chemogenetics by using physical and biological light sources for opsin activation

    PubMed Central

    Berglund, Ken; Clissold, Kara; Li, Haofang E.; Wen, Lei; Park, Sung Young; Gleixner, Jan; Klein, Marguerita E.; Lu, Dongye; Barter, Joseph W.; Rossi, Mark A.; Augustine, George J.; Yin, Henry H.; Hochgeschwender, Ute

    2016-01-01

    Luminopsins are fusion proteins of luciferase and opsin that allow interrogation of neuronal circuits at different temporal and spatial resolutions by choosing either extrinsic physical or intrinsic biological light for its activation. Building on previous development of fusions of wild-type Gaussia luciferase with channelrhodopsin, here we expanded the utility of luminopsins by fusing bright Gaussia luciferase variants with either channelrhodopsin to excite neurons (luminescent opsin, LMO) or a proton pump to inhibit neurons (inhibitory LMO, iLMO). These improved LMOs could reliably activate or silence neurons in vitro and in vivo. Expression of the improved LMO in hippocampal circuits not only enabled mapping of synaptic activation of CA1 neurons with fine spatiotemporal resolution but also could drive rhythmic circuit excitation over a large spatiotemporal scale. Furthermore, virus-mediated expression of either LMO or iLMO in the substantia nigra in vivo produced not only the expected bidirectional control of single unit activity but also opposing effects on circling behavior in response to systemic injection of a luciferase substrate. Thus, although preserving the ability to be activated by external light sources, LMOs expand the use of optogenetics by making the same opsins accessible to noninvasive, chemogenetic control, thereby allowing the same probe to manipulate neuronal activity over a range of spatial and temporal scales. PMID:26733686

  10. Method and apparatus for making absolute range measurements

    DOEpatents

    Earl, Dennis D [Knoxville, TN; Allison, Stephen W [Knoxville, TN; Cates, Michael R [Oak Ridge, TN; Sanders, Alvin J [Knoxville, TN

    2002-09-24

    This invention relates to a method and apparatus for making absolute distance or ranging measurements using Fresnel diffraction. The invention employs a source of electromagnetic radiation having a known wavelength or wavelength distribution, which sends a beam of electromagnetic radiation through a screen at least partially opaque at the wavelength. The screen has an aperture sized so as to produce a Fresnel diffraction pattern. A portion of the beam travels through the aperture to a detector spaced some distance from the screen. The detector detects the central intensity of the beam as well as a set of intensities displaced from a center of the aperture. The distance from the source to the target can then be calculated based upon the known wavelength, aperture radius, and beam intensity.

  11. An investigation into active vibration isolation based on predictive control: Part I: Energy source control

    NASA Astrophysics Data System (ADS)

    Fei, H. Z.; Zheng, G. T.; Liu, Z. G.

    2006-09-01

    We report the results of a recent study for the active vibration isolation with whole-spacecraft vibration isolation as an application background into which three parts are divided: (i) energy source control, (ii) nonlinearity and time delay, (iii) implementation and experiment. This paper is the first in this three-part series report, which presents theoretical and experimental investigations into pressure tracking system for energy source control of the isolator. Considering the special environment of the rocket and expected characteristics of actuators, where the isolator will be arranged between the rocket and the spacecraft, pneumatic actuator is proposed to realize the active isolation control. In order to improve the dynamic characteristics of the pneumatic isolator, a cascade control algorithm with double loop structure and predictive control algorithm for pressure tracking control of the inner loop are proposed. In the current paper, a pressure tracking control system using model predictive control (MPC) is studied first. A pneumatic model around pressure work point is built firstly by simplifying the flow equation of valve's orifices and pressure differential equation of the chambers. With this model, an MPC algorithm in the state space is developed, and problems including control parameter choice and command horizon generator are discussed in detail. In addition, by adding model error correction loop and velocity compensation feedback, effects of model uncertainty and volume variation of chambers are reduced greatly. Thus with this design, the real-time pressure tracking can be guaranteed, and so that the active control system can work at higher frequency range.

  12. Estimated source intensity and active space of the American alligator (Alligator Mississippiensis) vocal display.

    PubMed

    Todd, Neil P McAngus

    2007-11-01

    In this article the results are reported of a study to measure the intensity of the vocal displays of a population of American alligators (Alligator mississippiensis). It was found that the dominant frequencies in air range between 20 and 250 Hz with a source sound pressure level (SPL) of 91-94 dB at 1 m. The active space for the air-borne component is defined by the background and was estimated to be in a range up to 159 m in the 125-200 Hz band. For the water-borne component the dominant frequency range was 20-100 Hz with a source SPL of 121-125 dB at 1 m. The active space in water is defined by hearing thresholds and was estimated to range up to 1.5 km in the 63-100 Hz band. In the lowest frequency bands, i.e., 16-50 Hz, the estimated active space for otolith detection of near-field particle motion in water ranged to 80 m, which compared significantly with far-field detection for these frequencies. It is suggested that alligator vocal communication may involve two distinct sensory mechanisms which may subserve the functions of scene analysis and reproduction, respectively.

  13. Brain activity during source memory retrieval in young, middle-aged and old adults.

    PubMed

    Cansino, Selene; Trejo-Morales, Patricia; Estrada-Manilla, Cinthya; Pasaye-Alcaraz, Erick Humberto; Aguilar-Castañeda, Erika; Salgado-Lujambio, Perla; Sosa-Ortiz, Ana Luisa

    2015-08-27

    We investigated neurofunctional changes associated with source memory decline across the adult life span using functional magnetic resonance imaging (fMRI). Young, middle-aged and old adults carried out a natural/artificial judgment of images of common objects that were randomly presented in one of the quadrants of the screen. At retrieval, the images were displayed at the center of the screen and the participants judged whether each image was new or old and, if old, they indicated in which quadrant of the screen the image had originally been presented. Comparing the items associated with correct versus incorrect source judgments revealed that no regions showed greater activity in young adults than in middle-aged adults; however, in young and middle-aged adults the activity in the left hippocampus and left anterior temporal cortex was of greater magnitude than in the older adults. Several regions also exhibited greater activity in young adults than in old adults. These results suggest that in middle age the recollection neural network, assessable by fMRI, is still preserved.

  14. 242Pu absolute neutron-capture cross section measurement

    NASA Astrophysics Data System (ADS)

    Buckner, M. Q.; Wu, C. Y.; Henderson, R. A.; Bucher, B.; Chyzh, A.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Jandel, M.; Mosby, S.; O'Donnell, J. M.; Ullmann, J. L.

    2017-09-01

    The absolute neutron-capture cross section of 242Pu was measured at the Los Alamos Neutron Science Center using the Detector for Advanced Neutron-Capture Experiments array along with a compact parallel-plate avalanche counter for fission-fragment detection. During target fabrication, a small amount of 239Pu was added to the active target so that the absolute scale of the 242Pu(n,γ) cross section could be set according to the known 239Pu(n,f) resonance at En,R = 7.83 eV. The relative scale of the 242Pu(n,γ) cross section covers four orders of magnitude for incident neutron energies from thermal to ≈ 40 keV. The cross section reported in ENDF/B-VII.1 for the 242Pu(n,γ) En,R = 2.68 eV resonance was found to be 2.4% lower than the new absolute 242Pu(n,γ) cross section.

  15. Investigating the absolute phase information in acoustic wave resonance scattering

    PubMed Central

    Mitri, F.G.; Greenleaf, J.F.; Fellah, Z.E.A.; Fatemi, M.

    2014-01-01

    The aim if this work is to investigate the absolute phase information in resonance acoustic scattering by spheres and cylinders and place this work in the broader context of scattering in which the properties of the magnitude and (processed) phase have been examined in a more general way than in the classical Resonance Scattering Theory (RST). Here, comparisons are made between the classical and modified RST formalisms of acoustic resonance scattering. Experimental and theoretical backscattering form functions are obtained and discussed. It is shown that the magnitude and processed (unwrapped) phase can be correctly obtained through the classical RST, suggesting that the modified RST formalism offers little new practical advantage. Furthermore, the absolute phase is shown to be very sensitive to object's resonances, suggesting that the unwrapped phase may be considered as an efficient tool, along with the magnitude information, to carry out remote (active) classification of targets in underwater acoustics applications. The combination of absolute phase information with the magnitude data offers a complementary advantage in the identification of resonances from cylinders and spheres. PMID:18294670

  16. Multi-level continuous active source seismic monitoring (ML-CASSM): Application to shallow hydrofracture monitoring

    NASA Astrophysics Data System (ADS)

    Ajo Franklin, J. B.; Daley, T. M.; Butler-Veytia, B.; Peterson, J.; Gasperikova, E.; Hubbard, S. S.

    2010-12-01

    Induced subsurface processes occur over a wide variety of time scales ranging from seconds (e.g. fracture initiation) to days (e.g. unsteady multiphase flow) and weeks (e.g. induced mineral precipitation). Active source seismic monitoring has the potential to dynamically characterize such alterations and allow estimation of spatially localized rates. However, even optimal timelapse seismic surveys have limited temporal resolution due to both the time required to acquire a survey and the cost of continuous field deployment of instruments and personnel. Traditional timelapse surveys are also limited by experimental repeatability due to a variety of factors including geometry replication and near-surface conditions. Recent research has demonstrated the value of semi-permanently deployed seismic systems with fixed sources and receivers for use in monitoring a variety of processes including near-surface stress changes (Silver et.al. 2007), subsurface movement of supercritical CO2 (Daley et.al. 2007), and preseismic velocity changes in fault regions (Niu et. al. 2008). This strategy, referred to as continuous active source seismic monitoring (CASSM), allows both precise quantification of traveltime changes on the order of 1.1 x 10-7 s and temporal sampling on the order of minutes. However, as previously deployed, CASSM often sacrifices spatial resolution for temporal resolution with previous experiments including only a single source level. We present results from the first deployment of CASSM with a large number of source levels under automated control. Our system is capable of autonomously acquiring full tomographic datasets (10 sources, 72 receivers) in 3 minutes without human intervention, thus allowing active source seismic imaging (rather than monitoring) of processes with short durations. Because no sources or receivers are moved in the acquisition process, signal repeatability is excellent and subtle waveform changes can be interpreted with increased confidence

  17. Long distance active hyperspectral sensing using high-power near-infrared supercontinuum light source.

    PubMed

    Manninen, Albert; Kääriäinen, Teemu; Parviainen, Tomi; Buchter, Scott; Heiliö, Miika; Laurila, Toni

    2014-03-24

    A hyperspectral remote sensing instrument employing a novel near-infrared supercontinuum light source has been developed for active illumination and identification of targets. The supercontinuum is generated in a standard normal dispersion multi-mode fiber and has 16 W total optical output power covering 1000 nm to 2300 nm spectral range. A commercial 256-channel infrared spectrometer was used for broadband infrared detection. The feasibility of the presented hyperspectral measurement approach was investigated both indoors and in the field. Reflection spectra from several diffusive targets were successfully measured and a measurement range of 1.5 km was demonstrated.

  18. Exploration of amphoteric and negative refraction imaging of acoustic sources via active metamaterials

    NASA Astrophysics Data System (ADS)

    Wen, Jihong; Shen, Huijie; Yu, Dianlong; Wen, Xisen

    2013-11-01

    The present work describes the design of three flat superlens structures for acoustic source imaging and explores an active acoustic metamaterial (AAM) to realise such a design. The first two lenses are constructed via the coordinate transform method (CTM), and their constituent materials are anisotropic. The third lens consists of a material that has both a negative density and a negative bulk modulus. In these lenses, the quality of the images is “clear” and sharp; thus, the diffraction limit of classical lenses is overcome. Finally, a multi-control strategy is developed to achieve the desired parameters and to eliminate coupling effects in the AAM.

  19. Source mechanism of very-long-period signals accompanying dome growth activity at Merapi volcano, Indonesia

    USGS Publications Warehouse

    Hidayat, D.; Chouet, B.; Voight, B.; Dawson, P.; Ratdomopurbo, A.

    2002-01-01

    Very-long-period (VLP) pulses with period of 6-7s, displaying similar waveforms, were identified in 1998 from broadband seismographs around the summit crater. These pulses accompanied most of multiphase (MP) earthquakes, a type of long-period event locally defined at Merapi Volcano. Source mechanisms for several VLP pulses were examined by applying moment tensor inversion to the waveform data. Solutions were consistent with a crack striking ???70?? and dipping ???50?? SW, 100m under the active dome, suggest pressurized gas transport involving accumulation and sudden release of 10-60 m3 of gas in the crack over a 6s interval.

  20. Packaged Fault Model for Geometric Segmentation of Active Faults Into Earthquake Source Faults

    NASA Astrophysics Data System (ADS)

    Nakata, T.; Kumamoto, T.

    2004-12-01

    successfully on the active faults generated the 1943 Tottori earthquake, the Chojagahara-Yoshii fault zone in Chugoku district in southwest Japan, as well as the active fault system in northern Luzon, the Philippines. Thus, we name this conceptual model as _gPackaged Fault Model_h and call the active faults grouped by the model as _gPackaged Faults_h for individual earthquake source faults. Moreover, we come to know that active fault mapping with _gPackaged Fault Model_h in mind enables us to find many new active fault traces (e.g., the Shigenobu fault along the MTL in Japan).

  1. Immortelle (Xeranthemum annuum L.) as a natural source of biologically active substances.

    PubMed

    Stankovic, Milan S; Radojevic, Ivana D; Stefanovic, Olgica D; Topuzovic, Marina D; Comic, Ljiljana R; Brankovic, Snežana R

    2011-01-01

    Antioxidant and antimicrobial effects, total phenolic content and flavonoid concentrations of methanolic, acetone and ethyl acetate extracts from Xeranthemum annuum L. were investigated in this study. The total phenolic content was determined using Folin-Ciocalteu reagent and ranged between 101.33 to 159.48 mg GA/g. The concentration of flavonoids in various X.annuum extracts was determined using spectrophotometric method with aluminum chloride and the results varied from 22.25 to 62.42 mg RU/g. Antioxidant activity was monitored spectrophotometrically using DPPH reagent and expressed in terms of IC50 (µg/ml), and it ranged from 59.25 to 956.81 µg/ml. The highest phenolic content and capacity to neutralize DPPH radicals were found in the acetone extract. In vitro antimicrobial activity was determined by microdilution method. Minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) have been determined. Testing was conducted against 24 microorganisms, including 15 strains of bacteria (standard and clinical strains) and 9 species of fungi. Statistically significant difference in activity between the extracts of X. annuum L. was observed and the acetone extract was found most active. The activity of acetone extract was in accordance with total phenol content and flavonoid concentration measured in this extract. The tested extracts showed significant antibacterial activity against G+ bacteria and weak to moderate activity against other microorganisms. Based on the obtained results, X. annuum can be considered as a rich natural source of polyphenolic compounds with very good antioxidant and antimicrobial activity.

  2. Immortelle (Xeranthemum annuum L.) as a natural source of biologically active substances

    PubMed Central

    Stankovic, Milan S.; Radojevic, Ivana D.; Stefanovic, Olgica D.; Topuzovic, Marina D.; Comic, Ljiljana R.; Brankovic, Snežana R.

    2011-01-01

    Antioxidant and antimicrobial effects, total phenolic content and flavonoid concentrations of methanolic, acetone and ethyl acetate extracts from Xeranthemum annuum L. were investigated in this study. The total phenolic content was determined using Folin-Ciocalteu reagent and ranged between 101.33 to 159.48 mg GA/g. The concentration of flavonoids in various X. annuum extracts was determined using spectrophotometric method with aluminum chloride and the results varied from 22.25 to 62.42 mg RU/g. Antioxidant activity was monitored spectrophotometrically using DPPH reagent and expressed in terms of IC50 (µg/ml), and it ranged from 59.25 to 956.81 µg/ml. The highest phenolic content and capacity to neutralize DPPH radicals were found in the acetone extract. In vitro antimicrobial activity was determined by microdilution method. Minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) have been determined. Testing was conducted against 24 microorganisms, including 15 strains of bacteria (standard and clinical strains) and 9 species of fungi. Statistically significant difference in activity between the extracts of X. annuum L. was observed and the acetone extract was found most active. The activity of acetone extract was in accordance with total phenol content and flavonoid concentration measured in this extract. The tested extracts showed significant antibacterial activity against G+ bacteria and weak to moderate activity against other microorganisms. Based on the obtained results, X. annuum can be considered as a rich natural source of polyphenolic compounds with very good antioxidant and antimicrobial activity. PMID:27857677

  3. Absolute-magnitude distributions of supernovae

    SciTech Connect

    Richardson, Dean; Wright, John; Jenkins III, Robert L.; Maddox, Larry

    2014-05-01

    The absolute-magnitude distributions of seven supernova (SN) types are presented. The data used here were primarily taken from the Asiago Supernova Catalogue, but were supplemented with additional data. We accounted for both foreground and host-galaxy extinction. A bootstrap method is used to correct the samples for Malmquist bias. Separately, we generate volume-limited samples, restricted to events within 100 Mpc. We find that the superluminous events (M{sub B} < –21) make up only about 0.1% of all SNe in the bias-corrected sample. The subluminous events (M{sub B} > –15) make up about 3%. The normal Ia distribution was the brightest with a mean absolute blue magnitude of –19.25. The IIP distribution was the dimmest at –16.75.

  4. From Hubble's NGSL to Absolute Fluxes

    NASA Technical Reports Server (NTRS)

    Heap, Sara R.; Lindler, Don

    2012-01-01

    Hubble's Next Generation Spectral Library (NGSL) consists of R-l000 spectra of 374 stars of assorted temperature, gravity, and metallicity. Each spectrum covers the wavelength range, 0.18-1.00 microns. The library can be viewed and/or downloaded from the website, http://archive.stsci.edu/prepds/stisngsll. Stars in the NGSL are now being used as absolute flux standards at ground-based observatories. However, the uncertainty in the absolute flux is about 2%, which does not meet the requirements of dark-energy surveys. We are therefore developing an observing procedure that should yield fluxes with uncertainties less than 1 % and will take part in an HST proposal to observe up to 15 stars using this new procedure.

  5. Computer processing of spectrograms for absolute intensities.

    PubMed

    Guttman, A; Golden, J; Galbraith, H J

    1967-09-01

    A computer program was developed to process photographically recorded spectra for absolute intensity. Test and calibration films are subjected to densitometric scans that provide digitally recorded densities on magnetic tapes. The nonlinear calibration data are fitted by least-squares cubic polynomials to yield a good approximation to the monochromatic H&D curves for commonly used emulsions (2475 recording film, Royal-X, Tri-X, 4-X). Several test cases were made. Results of these cases show that the machine processed absolute intensities are accurate to within 15%o. Arbitrarily raising the sensitivity threshold by 0.1 density units above gross fog yields cubic polynomial fits to the H&D curves that are radiometrically accurate within 10%. In addition, curves of gamma vs wavelength for 2475, Tri-X, and 4-X emulsions were made. These data show slight evidence of the photographic Purkinje effect in the 2475 emulsion.

  6. Absolute magnitudes and kinematic properties of Cepheids.

    NASA Astrophysics Data System (ADS)

    Wilson, T. D.; Jefferys, W. H.; Barnes, T. G., III; Hawley, S. L.

    A maximum-likelihood statistical parallax analysis of classical Cepheids has been performed to determine the relative solar motion, Oort constants, velocity ellipsoid parameters, and zero points of the PL and PLC relations. The analysis is based upon 90 proper motions drawn from the list of Karimova and Pavlovskaya 1981 and upon the analytical approach of Hawley et al. 1986. The authors' results give a best estimate for the mean absolute magnitude of Cepheids at log P = 0.8 of = -3.46±0.33 mag. This estimate for the Cepheid absolute magnitude zero point is highly stable against refinements in the mathematical technique and against additional Cepheid proper motion data of quality similar to the existing proper motions. Improvement in this value will likely come only from a marked improvement in the quality of the Cepheid proper motions.

  7. [Absolute bioavailability of chlorpromazine, promazine and promethazine].

    PubMed

    Koytchev, R; Alken, R G; Kirkov, V; Neshev, G; Vagaday, M; Kunter, U

    1994-02-01

    The absolute bioavailability of the three phenothiazine neuroleptics, promazine (Sinophenin, CAS 58-40-2), chlorpromazine (Propaphenin, CAS 50-53-3) and promethazine (Prothazin, CAS 60-87-7) was tested in three single-dose cross-over studies. In each trial 12 to 14 healthy volunteers were enrolled. The single doses for promazine, promethazine and chlorpromazine were 100, 75 and 150 mg (orally) and 20, 50 and 50 mg (intravenously), resp. The serum concentrations of the three neuroleptics were measured by means of a selective HPLC-method. the distribution-free confidence intervals for the absolute bioavailability of the three phenothiazines were within 10.5 to 24.7% for chlorpromazine, 7.8 to 24.9% for promazine and 12.3 to 40% for promethazine. Promazine and chlorpromazine are pharmacokinetically very similar and differ substantially from promethazine.

  8. 237Np absolute delayed neutron yield measurements

    NASA Astrophysics Data System (ADS)

    Doré, D.; Ledoux, X.; Nolte, R.; Gagnon-Moisan, F.; Thulliez, L.; Litaize, O.; Roettger, S.; Serot, O.

    2017-09-01

    237Np absolute delayed neutron yields have been measured at different incident neutron energies from 1.5 to 16 MeV. The experiment was performed at the Physikalisch-Technische Bundesanstalt (PTB) facility where the Van de Graaff accelerator and the cyclotron CV28 delivered 9 different neutron energy beams using p+T, d+D and d+T reactions. The detection system is made up of twelve 3He tubes inserted into a polyethylene cylinder. In this paper, the experimental setup and the data analysis method are described. The evolution of the absolute DN yields as a function of the neutron incident beam energies are presented and compared to experimental data found in the literature and data from the libraries.

  9. Asteroid absolute magnitudes and slope parameters

    NASA Technical Reports Server (NTRS)

    Tedesco, Edward F.

    1991-01-01

    A new listing of absolute magnitudes (H) and slope parameters (G) has been created and published in the Minor Planet Circulars; this same listing will appear in the 1992 Ephemerides of Minor Planets. Unlike previous listings, the values of the current list were derived from fits of data at the V band. All observations were reduced in the same fashion using, where appropriate, a single basis default value of 0.15 for the slope parameter. Distances and phase angles were computed for each observation. The data for 113 asteroids was of sufficiently high quality to permit derivation of their H and G. These improved absolute magnitudes and slope parameters will be used to deduce the most reliable bias-corrected asteroid size-frequency distribution yet made.

  10. Probing absolute spin polarization at the nanoscale.

    PubMed

    Eltschka, Matthias; Jäck, Berthold; Assig, Maximilian; Kondrashov, Oleg V; Skvortsov, Mikhail A; Etzkorn, Markus; Ast, Christian R; Kern, Klaus

    2014-12-10

    Probing absolute values of spin polarization at the nanoscale offers insight into the fundamental mechanisms of spin-dependent transport. Employing the Zeeman splitting in superconducting tips (Meservey-Tedrow-Fulde effect), we introduce a novel spin-polarized scanning tunneling microscopy that combines the probing capability of the absolute values of spin polarization with precise control at the atomic scale. We utilize our novel approach to measure the locally resolved spin polarization of magnetic Co nanoislands on Cu(111). We find that the spin polarization is enhanced by 65% when increasing the width of the tunnel barrier by only 2.3 Å due to the different decay of the electron orbitals into vacuum.

  11. An absolute measure for a key currency

    NASA Astrophysics Data System (ADS)

    Oya, Shunsuke; Aihara, Kazuyuki; Hirata, Yoshito

    It is generally considered that the US dollar and the euro are the key currencies in the world and in Europe, respectively. However, there is no absolute general measure for a key currency. Here, we investigate the 24-hour periodicity of foreign exchange markets using a recurrence plot, and define an absolute measure for a key currency based on the strength of the periodicity. Moreover, we analyze the time evolution of this measure. The results show that the credibility of the US dollar has not decreased significantly since the Lehman shock, when the Lehman Brothers bankrupted and influenced the economic markets, and has increased even relatively better than that of the euro and that of the Japanese yen.

  12. Consistent thermostatistics forbids negative absolute temperatures

    NASA Astrophysics Data System (ADS)

    Dunkel, Jörn; Hilbert, Stefan

    2014-01-01

    Over the past 60 years, a considerable number of theories and experiments have claimed the existence of negative absolute temperature in spin systems and ultracold quantum gases. This has led to speculation that ultracold gases may be dark-energy analogues and also suggests the feasibility of heat engines with efficiencies larger than one. Here, we prove that all previous negative temperature claims and their implications are invalid as they arise from the use of an entropy definition that is inconsistent both mathematically and thermodynamically. We show that the underlying conceptual deficiencies can be overcome if one adopts a microcanonical entropy functional originally derived by Gibbs. The resulting thermodynamic framework is self-consistent and implies that absolute temperature remains positive even for systems with a bounded spectrum. In addition, we propose a minimal quantum thermometer that can be implemented with available experimental techniques.

  13. Absolute and relative dosimetry for ELIMED

    NASA Astrophysics Data System (ADS)

    Cirrone, G. A. P.; Cuttone, G.; Candiano, G.; Carpinelli, M.; Leonora, E.; Lo Presti, D.; Musumarra, A.; Pisciotta, P.; Raffaele, L.; Randazzo, N.; Romano, F.; Schillaci, F.; Scuderi, V.; Tramontana, A.; Cirio, R.; Marchetto, F.; Sacchi, R.; Giordanengo, S.; Monaco, V.

    2013-07-01

    The definition of detectors, methods and procedures for the absolute and relative dosimetry of laser-driven proton beams is a crucial step toward the clinical use of this new kind of beams. Hence, one of the ELIMED task, will be the definition of procedures aiming to obtain an absolute dose measure at the end of the transport beamline with an accuracy as close as possible to the one required for clinical applications (i.e. of the order of 5% or less). Relative dosimetry procedures must be established, as well: they are necessary in order to determine and verify the beam dose distributions and to monitor the beam fluence and the energetic spectra during irradiations. Radiochromic films, CR39, Faraday Cup, Secondary Emission Monitor (SEM) and transmission ionization chamber will be considered, designed and studied in order to perform a fully dosimetric characterization of the ELIMED proton beam.

  14. Radioactive sealed sources: Reasonable accountability, exemption, and licensing activity thresholds -- A technical basis

    SciTech Connect

    Lee, D.W.; Shingleton, K.L.

    1996-07-01

    Perhaps owing to their small size and portability, some radiation accidents/incidents have involved radioactive sealed sources (RSSs). As a result, programs for the control and accountability of RSSs have come to be recommended and emplaced that essentially require RSSs to be controlled in a manner different from bulk, unsealed radioactive material. Crucially determining the total number of RSSs for which manpower-intensive radiation protection surveillance is provided is the individual RSS activity above which such surveillance is required and below which such effort is not considered cost effective. Individual RSS activity thresholds are typically determined through scenarios which impart a chosen internal or external limiting dose to Reference Man under specified exposure conditions. The resultant RSS threshold activity levels have meaning commensurate with the assumed scenario exposure parameters, i.e., if they are realistic and technically based. A review of how the Department of Energy (DOE), the International Atomic Energy Agency (IAEA), and the Nuclear Regulatory Commission (NRC) have determined their respective accountability, exemption, and licensing threshold activity values is provided. Finally, a fully explained method using references readily available to practicing health physicists is developed using realistic, technically-based calculation parameters by which RSS threshold activities may be locally generated.

  15. Antioxidant Activity of Individual Steryl Ferulates from Various Cereal Grain Sources.

    PubMed

    Zhu, Dan; Sánchez-Ferrer, Antoni; Nyström, Laura

    2016-02-26

    Steryl ferulates (SFs) are a subclass of bioactive lipids contributing to the health-promoting effects of whole grains. Most related studies focus on γ-oryzanol, a SF mixture from rice, since individual steryl ferulates are not commercially available. There is little evidence that individual SFs may vary in their bioactivity. The aim of this study was to evaluate the antioxidant activity of eight individual SFs by determining their radical scavenging capacity. Additional molecular properties of the individual SFs were determined by molecular simulation in order to identify correlations with their antioxidant activities. Our study demonstrates that individual SFs exhibit 1,1-diphenyl-2-picrylhydrazyl radical, hydroxyl radical, and superoxide anion radical scavenging abilities with subtle differences that were highly dependent on the kind of reaction taking place. The grouping of SFs by principle component analysis was mainly attributed to molecular properties, not antioxidant activities. Solvation energy was significantly correlated with some experimental observations. To our knowledge, this is the first study to evaluate the antioxidant activity of eight individual steryl ferulates from different sources. Results of this work will provide better insight into the antioxidant activity of SFs and the health benefits of whole grains.

  16. Activity Variation of Phanerochaete chrysosporium under Nanosilver Exposure by Controlling of Different Sulfide Sources

    PubMed Central

    Guo, Zhi; Chen, Guiqiu; Liu, Lingzhi; Zeng, Guangming; Huang, Zhenzhen; Chen, Anwei; Hu, Liang

    2016-01-01

    Due to the particular activation and inhibition behavior of silver nanoparticles (AgNPs) on microbes at various concentrations, it’s crucial to exploit the special concentration effect in environment. Here, we studied the viability variation of Phanerochaete chrysosporium (P. chrysosporium) under exposure to citrate-coated AgNPs (Citrate-AgNPs) in the presence of different sulfide sources (an inorganic sulfide, NaHS and an organic sulfide, thioacetamide (TAA)). The results indicated that both NaHS and TAA can promote activation of P. chrysosporium by Citrate-AgNPs at a higher concentration, which was initial at toxic level. Treatment with various concentrations of Citrate-AgNPs (0–9 mg/L) demonstrated a maximum activation concentration (MAC) at 3 mg/L. With the increase in sulfide concentration, MAC transferred to higher concentration significantly, indicating the obvious “toxicity to activation” transformation at a higher concentration. Ag+ testing exhibited that variations in sulfide-induced Ag+ concentration (3−7 μg/L Ag+) accounted for the “toxicity to activation” transformation. In addition, the similar results were observed on antibacterial application using Escherichia coli as the model species. Based on the research results, the application of this transformation in improving antibacterial activity was proposed. Therefore, the antibacterial activity of AgNPs can be controlled, even at concentration, via adjusting for the sulfide concentration. PMID:26864597

  17. Activity Variation of Phanerochaete chrysosporium under Nanosilver Exposure by Controlling of Different Sulfide Sources

    NASA Astrophysics Data System (ADS)

    Guo, Zhi; Chen, Guiqiu; Liu, Lingzhi; Zeng, Guangming; Huang, Zhenzhen; Chen, Anwei; Hu, Liang

    2016-02-01

    Due to the particular activation and inhibition behavior of silver nanoparticles (AgNPs) on microbes at various concentrations, it’s crucial to exploit the special concentration effect in environment. Here, we studied the viability variation of Phanerochaete chrysosporium (P. chrysosporium) under exposure to citrate-coated AgNPs (Citrate-AgNPs) in the presence of different sulfide sources (an inorganic sulfide, NaHS and an organic sulfide, thioacetamide (TAA)). The results indicated that both NaHS and TAA can promote activation of P. chrysosporium by Citrate-AgNPs at a higher concentration, which was initial at toxic level. Treatment with various concentrations of Citrate-AgNPs (0–9 mg/L) demonstrated a maximum activation concentration (MAC) at 3 mg/L. With the increase in sulfide concentration, MAC transferred to higher concentration significantly, indicating the obvious “toxicity to activation” transformation at a higher concentration. Ag+ testing exhibited that variations in sulfide-induced Ag+ concentration (3‑7 μg/L Ag+) accounted for the “toxicity to activation” transformation. In addition, the similar results were observed on antibacterial application using Escherichia coli as the model species. Based on the research results, the application of this transformation in improving antibacterial activity was proposed. Therefore, the antibacterial activity of AgNPs can be controlled, even at concentration, via adjusting for the sulfide concentration.

  18. Particle Filter with Integrated Voice Activity Detection for Acoustic Source Tracking

    NASA Astrophysics Data System (ADS)

    Lehmann, Eric A.; Johansson, Anders M.

    2006-12-01

    In noisy and reverberant environments, the problem of acoustic source localisation and tracking (ASLT) using an array of microphones presents a number of challenging difficulties. One of the main issues when considering real-world situations involving human speakers is the temporally discontinuous nature of speech signals: the presence of silence gaps in the speech can easily misguide the tracking algorithm, even in practical environments with low to moderate noise and reverberation levels. A natural extension of currently available sound source tracking algorithms is the integration of a voice activity detection (VAD) scheme. We describe a new ASLT algorithm based on a particle filtering (PF) approach, where VAD measurements are fused within the statistical framework of the PF implementation. Tracking accuracy results for the proposed method is presented on the basis of synthetic audio samples generated with the image method, whereas performance results obtained with a real-time implementation of the algorithm, and using real audio data recorded in a reverberant room, are published elsewhere. Compared to a previously proposed PF algorithm, the experimental results demonstrate the improved robustness of the method described in this work when tracking sources emitting real-world speech signals, which typically involve significant silence gaps between utterances.

  19. Multiple sequential light and laser sources to activate aminolevulinic acid for rosacea.

    PubMed

    Friedmann, Daniel P; Goldman, Mitchel P; Fabi, Sabrina G; Guiha, Isabella

    2016-12-01

    The use of multiple, sequential light and laser sources for topical ALA activation in photodynamic therapy (PDT) of rosacea has been largely absent from the literature. The aim of this study was to evaluate ALA-PDT for rosacea using blue light sequentially with red light, pulsed-dye laser (PDL), and/or intense pulsed light (IPL). Thirty patients (39 treatments) were enrolled in this retrospective, single-center study. Treatment groups included blue light + PDL, blue light + IPL, blue light + PDL + IPL, or blue light + red light + PDL + IPL. Patient-reported outcome measures (incidence of adverse events, improvement in rosacea, and improvement in overall skin quality) were obtained via a telephone questionnaire and graded on a 4-point scale. There was no statistically significant difference in patient-reported rosacea or overall skin quality improvement. Apart from decreased peeling following blue light + IPL compared to blue light + PDL (P = 0.041) and blue light + IPL + PDL (P = 0.005), there were no other statistically significant differences in postprocedure adverse events. The use of multiple, sequential light and laser sources with ALA-PDT for rosacea, while well tolerated, did not lead to statistically significant improvements in patient-reported efficacy. Although this retrospective study is limited by a small sample size with disparate patient numbers between groups and no physician-evaluated outcome criteria, it does demonstrate that multiple light sources with PDT can be safely used in a single session. © 2016 Wiley Periodicals, Inc.

  20. Silicon Absolute X-Ray Detectors

    SciTech Connect

    Seely, John F.; Korde, Raj; Sprunck, Jacob; Medjoubi, Kadda; Hustache, Stephanie

    2010-06-23

    The responsivity of silicon photodiodes having no loss in the entrance window, measured using synchrotron radiation in the 1.75 to 60 keV range, was compared to the responsivity calculated using the silicon thickness measured using near-infrared light. The measured and calculated responsivities agree with an average difference of 1.3%. This enables their use as absolute x-ray detectors.

  1. Seismic Source Mechanism of Gas-Piston Activity at Kilauea Inferred from Inversion of Broadband Waveforms

    NASA Astrophysics Data System (ADS)

    Chouet, B. A.; Dawson, P. B.

    2015-12-01

    Among the broad range of magmatic processes observed in the Overlook pit crater in Kilauea Caldera are recurring episodes of gas-piston activity. This activity is accompanied by repetitive seismic signals recorded by a broadband network deployed in the summit caldera. We use the seismic data to model the source mechanism of representative gas-piston events in a sequence that occurred on 20-25 August 2011 during a gentle inflation of the Kilauea summit. We apply a new waveform inversion method that accounts for the contributions from both translation and tilt in horizontal seismograms through the use of Green's functions representing the seismometer response to translation and tilt ground motions. This method enables a robust description of the source mechanism over the period range of 1 - 10,000 s. Most of the seismic wave field produced by gas-pistoning originates in a source region ~1 km below the eastern perimeter of Halema'uma'u pit crater. The observed waveforms are well explained by a simple volumetric source with geometry composed of two intersecting cracks featuring an east-striking crack (dike) dipping 80° to the north, intersecting a north-striking crack (inclined sheet) dipping 65° to the east. Each gas-piston event is characterized by a rapid inflation lasting a few minutes trailed by a slower deflation ramp extending up to 15 minutes, attributed to the efficient coupling at the source centroid location of the pressure and momentum changes accompanying the growth and collapse of a layer of foam at the top of the magma column. Assuming a simple lumped parameter representation of the shallow magmatic system, the observed pressure and volume variations can be modeled with the following attributes: foam thickness (10 - 50 m), foam cell diameter (0.04 - 0.10 m), and gas-injection velocity (0.01 - 0.06 m s-1). Based on the change in the period of very-long-period oscillations accompanying the onset of the gas-piston signal and tilt evidence, the height of

  2. Aspidosperma species as sources of antimalarials. Part III. A review of traditional use and antimalarial activity.

    PubMed

    de Paula, Renata Cristina; Dolabela, Maria Fâni; de Oliveira, Alaíde Braga

    2014-03-01

    Several plant species belonging to the genus Aspidosperma are traditionally used in Brazil and other Meso- and South American countries for the treatment of malaria and fevers. These traditional uses were motivation for this review. A literature survey completed for this review has identified scientific bibliographical references to the use of 24 Aspidosperma species to treat malaria/fevers and to 19 species that have had their extracts and/or alkaloids evaluated, with good results, for in vitro and/or in vivo antimalarial activity. Indole alkaloids are typical constituents of Aspidosperma species. However, only 20 out of more than 200 known indole alkaloids isolated from this genus have been assayed for antimalarial activity. These data support the potential of Aspidosperma species as sources of antimalarials and the importance of research aimed at validating their use in the treatment of human malaria. Georg Thieme Verlag KG Stuttgart · New York.

  3. Radionuclide preparations with high specific activity and gamma-sources on their basis

    SciTech Connect

    Chesanov, V.V.; Demchenko, N.F.; Karasev, V.I.

    1993-12-31

    According to expert`s estimations, the following radionuclides and specific activities will be in great demand in the future: cobalt 60 (400-500Ci/g), iridium 192 (500-800 Ci/g), ytterbium 169 (800-1000 Ci/g), thulium 170 (700-800 Ci/g), selenium 75 (500-800 Ci/g), antimony 124 (30-40 Ci/g), and gadolinium 153 (not less than 50 Ci/g). In addition, the Phosphorus 33 radionuclide preparations with specific activity more than 100,000 Ci/g applied in biochemical investigations are in considerable demand. This paper discusses the investigations and developmental results performed with the preparation and sources of the mentioned radionuclides. The research reactors utilized are also described.

  4. Preseismic Velocity Changes Observed from Active Source Monitoringat the Parkfield SAFOD Drill Site

    SciTech Connect

    Daley, Thomas; Niu, Fenglin; Silver, Paul G.; Daley, Thomas M.; Cheng, Xin; Majer, Ernest L.

    2008-06-10

    Measuring stress changes within seismically active fault zones has been a long-sought goal of seismology. Here we show that such stress changes are measurable by exploiting the stress dependence of seismic wave speed from an active source cross-well experiment conducted at the SAFOD drill site. Over a two-month period we observed an excellent anti-correlation between changes in the time required for an S wave to travel through the rock along a fixed pathway--a few microseconds--and variations in barometric pressure. We also observed two large excursions in the traveltime data that are coincident with two earthquakes that are among those predicted to produce the largest coseismic stress changes at SAFOD. Interestingly, the two excursions started approximately 10 and 2 hours before the events, respectively, suggesting that they may be related to pre-rupture stress induced changes in crack properties, as observed in early laboratory studies.

  5. The absolute dynamic ocean topography (ADOT)

    NASA Astrophysics Data System (ADS)

    Bosch, Wolfgang; Savcenko, Roman

    The sea surface slopes relative to the geoid (an equipotential surface) basically carry the in-formation on the absolute velocity field of the surface circulation. Pure oceanographic models may remain unspecific with respect to the absolute level of the ocean topography. In contrast, the geodetic approach to estimate the ocean topography as difference between sea level and the geoid gives by definition an absolute dynamic ocean topography (ADOT). This approach requires, however, a consistent treatment of geoid and sea surface heights, the first being usually derived from a band limited spherical harmonic series of the Earth gravity field and the second observed with much higher spectral resolution by satellite altimetry. The present contribution shows a procedure for estimating the ADOT along the altimeter profiles, preserving as much sea surface height details as the consistency w.r.t. the geoid heights will allow. The consistent treatment at data gaps and the coast is particular demanding and solved by a filter correction. The ADOT profiles are inspected for their innocent properties towards the coast and compared to external estimates of the ocean topography or the velocity field of the surface circulation as derived, for example, by ARGO floats.

  6. Measurement of absolute gravity acceleration in Firenze

    NASA Astrophysics Data System (ADS)

    de Angelis, M.; Greco, F.; Pistorio, A.; Poli, N.; Prevedelli, M.; Saccorotti, G.; Sorrentino, F.; Tino, G. M.

    2011-01-01

    This paper reports the results from the accurate measurement of the acceleration of gravity g taken at two separate premises in the Polo Scientifico of the University of Firenze (Italy). In these laboratories, two separate experiments aiming at measuring the Newtonian constant and testing the Newtonian law at short distances are in progress. Both experiments require an independent knowledge on the local value of g. The only available datum, pertaining to the italian zero-order gravity network, was taken more than 20 years ago at a distance of more than 60 km from the study site. Gravity measurements were conducted using an FG5 absolute gravimeter, and accompanied by seismic recordings for evaluating the noise condition at the site. The absolute accelerations of gravity at the two laboratories are (980 492 160.6 ± 4.0) μGal and (980 492 048.3 ± 3.0) μGal for the European Laboratory for Non-Linear Spectroscopy (LENS) and Dipartimento di Fisica e Astronomia, respectively. Other than for the two referenced experiments, the data here presented will serve as a benchmark for any future study requiring an accurate knowledge of the absolute value of the acceleration of gravity in the study region.

  7. Chemical composition of French mimosa absolute oil.

    PubMed

    Perriot, Rodolphe; Breme, Katharina; Meierhenrich, Uwe J; Carenini, Elise; Ferrando, Georges; Baldovini, Nicolas

    2010-02-10

    Since decades mimosa (Acacia dealbata) absolute oil has been used in the flavor and perfume industry. Today, it finds an application in over 80 perfumes, and its worldwide industrial production is estimated five tons per year. Here we report on the chemical composition of French mimosa absolute oil. Straight-chain analogues from C6 to C26 with different functional groups (hydrocarbons, esters, aldehydes, diethyl acetals, alcohols, and ketones) were identified in the volatile fraction. Most of them are long-chain molecules: (Z)-heptadec-8-ene, heptadecane, nonadecane, and palmitic acid are the most abundant, and constituents such as 2-phenethyl alcohol, methyl anisate, and ethyl palmitate are present in smaller amounts. The heavier constituents were mainly triterpenoids such as lupenone and lupeol, which were identified as two of the main components. (Z)-Heptadec-8-ene, lupenone, and lupeol were quantified by GC-MS in SIM mode using external standards and represents 6%, 20%, and 7.8% (w/w) of the absolute oil. Moreover, odorant compounds were extracted by SPME and analyzed by GC-sniffing leading to the perception of 57 odorant zones, of which 37 compounds were identified by their odorant description, mass spectrum, retention index, and injection of the reference compound.

  8. Negative absolute temperature for mobile particles

    NASA Astrophysics Data System (ADS)

    Braun, Simon; Ronzheimer, Philipp; Schreiber, Michael; Hodgman, Sean; Bloch, Immanuel; Schneider, Ulrich

    2013-05-01

    Absolute temperature is usually bound to be strictly positive. However, negative absolute temperature states, where the occupation probability of states increases with their energy, are possible in systems with an upper energy bound. So far, such states have only been demonstrated in localized spin systems with finite, discrete spectra. We realized a negative absolute temperature state for motional degrees of freedom with ultracold bosonic 39K atoms in an optical lattice, by implementing the attractive Bose-Hubbard Hamiltonian. This new state strikingly revealed itself by a quasimomentum distribution that is peaked at maximum kinetic energy. The measured kinetic energy distribution and the extracted negative temperature indicate that the ensemble is close to degeneracy, with coherence over several lattice sites. The state is as stable as a corresponding positive temperature state: The negative temperature stabilizes the system against mean-field collapse driven by negative pressure. Negative temperatures open up new parameter regimes for cold atoms, enabling fundamentally new many-body states. Additionally, they give rise to several counterintuitive effects such as heat engines with above unity efficiency.

  9. Activity ratios in soil contaminated by the source of different reactor condition in the FDNPP accident

    NASA Astrophysics Data System (ADS)

    Satou, Yukihiko; Sueki, Keisuke; Sasa, Kimikazu; Matsunaka, Tetsuya; Shibayama, Nao; Takahashi, Tsutomu; Kinoshita, Norikazu

    2014-05-01

    The Fukushima Dai-ichi Nuclear power plant (FDNPP) accident caused radioactive contamination on the surface soil at Fukushima and its adjacent prefectures. Substantial contamination has been found in the northwestern area from the FDNPP, according to the airborne monitoring and ground base survey by the Japanese government. Activity ratios would have characteristic information on emission sources because each relevant reactor had different amount of radionuclide and different activity ratio. The ratios can be used to clarify more detailed source and process in the contamination. We have addressed to consider them in Namie town, northwestern region from the FDNPP. This study focused on the gamma-ray emitting radionuclides of 134Cs, 137Cs, and 110mAg. The activities were decay-corrected as of 11th March, 2011 when all nuclear reactors scrammed. Data of activity ratios by our results and the Japanese official report classified the investigated northwestern region into 3 groups. Ratios of 0.02 for 110mAg/137Cs and 0.90 for 134Cs/137Cs were observed in the northern region of 15 km inside from the FDNPP. On the other hand, two kinds of 110mAg/137Cs ratios of 0.005 and 0.002 were distributed broadly in the region 60 km away from the plant. The 134Cs/137Cs ratio was 0.98 there. The activity ratios of 110mAg/137Cs and 134Cs/137Cs in the northern region from the FDNPP correspond to those of nuclear fuel in Unit 1 according to estimation using the ORIGEN code. The 134Cs/137Cs in the northwestern area from FDNPP agrees with that of Unit 2 and 3. The 110mAg/137Cs ratios of 0.005 and0.002 are 1/5 - 1/10 of the Unit 2 and 3. Official report has announced that discharges of the radionuclides from Unit 2 and 3 occurred on 14th March, 2011. It is known that contamination in the northwestern region from the FDNPP took place on 15th March, 2011. Plausible species for silver in reactor core, metal, and halide etc. have higher boiling point than those species for cesium. The core would

  10. Multi-Source Autonomous Response for Targeting and Monitoring of Volcanic Activity

    NASA Technical Reports Server (NTRS)

    Davies, Ashley G.; Doubleday, Joshua R.; Tran, Daniel Q.

    2014-01-01

    The study of volcanoes is important for both purely scientific and human survival reasons. From a scientific standpoint, volcanic gas and ash emissions contribute significantly to the terrestrial atmosphere. Ash depositions and lava flows can also greatly affect local environments. From a human survival standpoint, many people live within the reach of active volcanoes, and therefore can be endangered by both atmospheric (ash, debris) toxicity and lava flow. There are many potential information sources that can be used to determine how to best monitor volcanic activity worldwide. These are of varying temporal frequency, spatial regard, method of access, and reliability. The problem is how to incorporate all of these inputs in a general framework to assign/task/reconfigure assets to monitor events in a timely fashion. In situ sensing can provide a valuable range of complementary information such as seismographic, discharge, acoustic, and other data. However, many volcanoes are not instrumented with in situ sensors, and those that have sensor networks are restricted to a relatively small numbers of point sensors. Consequently, ideal volcanic study synergistically combines space and in situ measurements. This work demonstrates an effort to integrate spaceborne sensing from MODIS (Terra and Aqua), ALI (EO-1), Worldview-2, and in situ sensing in an automated scheme to improve global volcano monitoring. Specifically, it is a "sensor web" concept in which a number of volcano monitoring systems are linked together to monitor volcanic activity more accurately, and this activity measurement automatically tasks space assets to acquire further satellite imagery of ongoing volcanic activity. A general framework was developed for evidence combination that accounts for multiple information sources in a scientist-directed fashion to weigh inputs and allocate observations based on the confidence of an events occurrence, rarity of the event at that location, and other scientists

  11. Gross-beta activity in ground water: natural sources and artifacts of sampling and laboratory analysis

    USGS Publications Warehouse

    Welch, Alan H.

    1995-01-01

    Gross-beta activity has been used as an indicator of beta-emitting isotopes in water since at least the early 1950s. Originally designed for detection of radioactive releases from nuclear facilities and weapons tests, analysis of gross-beta activity is widely used in studies of naturally occurring radioactivity in ground water. Analyses of about 800 samples from 5 ground-water regions of the United States provide a basis for evaluating the utility of this measurement. The data suggest that measured gross-beta activities are due to (1) long-lived radionuclides in ground water, and (2) ingrowth of beta-emitting radionuclides during holding times between collection of samples and laboratory measurements.Although40K and228Ra appear to be the primary sources of beta activity in ground water, the sum of40K plus228Ra appears to be less than the measured gross-beta activity in most ground-water samples. The difference between the contribution from these radionuclides and gross-beta activity is most pronounced in ground water with gross-beta activities > 10 pCi/L, where these 2 radionuclides account for less than one-half the measured ross-beta activity. One exception is groundwater from the Coastal Plain of New Jersey, where40K plus228Ra generally contribute most of the gross-beta activity. In contrast,40K and228Ra generally contribute most of beta activity in ground water with gross-beta activities < 1 pCi/L.The gross-beta technique does not measure all beta activity in ground water. Although3H contributes beta activity to some ground water, it is driven from the sample before counting and therefore is not detected by gross-beta measurements. Beta-emitting radionuclides with half-lives shorter than a few days can decay to low values between sampling and counting. Although little is known about concentrations of most short-lived beta-emitting radionuclides in environmental ground water (water unaffected by direct releases from nuclear facilities and weapons tests), their

  12. Vocalisations of the bigeye Pempheris adspersa: characteristics, source level and active space.

    PubMed

    Radford, Craig A; Ghazali, Shahriman; Jeffs, Andrew G; Montgomery, John C

    2015-03-01

    Fish sounds are an important biological component of the underwater soundscape. Understanding species-specific sounds and their associated behaviour is critical for determining how animals use the biological component of the soundscape. Using both field and laboratory experiments, we describe the sound production of a nocturnal planktivore, Pempheris adspersa (New Zealand bigeye), and provide calculations for the potential effective distance of the sound for intraspecific communication. Bigeye vocalisations recorded in the field were confirmed as such by tank recordings. They can be described as popping sounds, with individual pops of short duration (7.9±0.3 ms) and a peak frequency of 405±12 Hz. Sound production varied during a 24 h period, with peak vocalisation activity occurring during the night, when the fish are most active. The source level of the bigeye vocalisation was 115.8±0.2 dB re. 1 µPa at 1 m, which is relatively quiet compared with other soniferous fish. Effective calling range, or active space, depended on both season and lunar phase, with a maximum calling distance of 31.6 m and a minimum of 0.6 m. The bigeyes' nocturnal behaviour, characteristics of their vocalisation, source level and the spatial scale of its active space reported in the current study demonstrate the potential for fish vocalisations to function effectively as contact calls for maintaining school cohesion in darkness. © 2015. Published by The Company of Biologists Ltd.

  13. Special Form Testing of Sealed Source Encapsulation for High-Alpha-Activity Actinide Materials

    SciTech Connect

    Martinez, Oscar A

    2016-01-01

    In the United States all transportation of radioactive material is regulated by the U.S. Department of Transportation (DOT). Beginning in 2008 a new type of sealed-source encapsulation package was developed and tested by Oak Ridge National Laboratory (ORNL). These packages contain high-alpha-activity actinides and are regulated and transported in accordance with the requirements for DOT Class 7 hazardous material. The DOT provides specific regulations pertaining to special form encapsulation designs. The special form designation indicates that the encapsulated radioactive contents have a very low probability of dispersion even when subjected to significant structural events. The special form designs have been shown to simplify the delivery, transport, acceptance, and receipt processes. It is intended for these sealed-source encapsulations to be shipped to various facilities making it very advantageous for them to be certified as special form. To this end, DOT Certificates of Competent Authority (CoCAs) have been sought for the design suitable for containing high-alpha-activity actinide materials. This design consists of the high-alpha-activity material encapsulated within a triangular zirconia canister, referred to as a ZipCan, tile that is then enclosed by a spherical shell. The spherical shell design, with ZipCan tile inside, was tested for compliance with the special form regulations found in 49 CFR 173.469. The spherical enclosure was subjected to 9-m impact, 1 m percussion, and 10-minute thermal tests at the Packaging Evaluation Facility located at the National Transportation Research Center in Knoxville, TN USA and operated by ORNL. Before and after each test, the test units were subjected to a helium leak check and a bubble test. The ZipCan tiles and core were also subjected to the tests required for ISO 2919:2012(E), including a Class IV impact test and heat test and subsequently subjected to helium leakage rate tests [49 CFR 173.469(a)(4)(i)]. The impact

  14. EEG source analysis of epileptiform activity using a 1mm anisotropic hexahedra finite element head model

    PubMed Central

    Rullmann, M.; Anwander, A.; Dannhauer, M.; Warfield, S.K.; Duffy, F.H.; Wolters, C.H.

    2009-01-01

    The major goal of the evaluation in presurgical epilepsy diagnosis for medically intractable patients is the precise reconstruction of the epileptogenic foci, preferably with non-invasive methods. This paper evaluates whether surface electroencephalography (EEG) source analysis based on a 1mm anisotropic finite element (FE) head model can provide additional guidance for presurgical epilepsy diagnosis and whether it is practically feasible in daily routine. A 1mm hexahedra FE volume conductor model of the patient’s head with special focus on accurately modeling the compartments skull, cerebrospinal fluid (CSF) and the anisotropic conducting brain tissues was constructed using non-linearly co-registered T1-, T2- and diffusion-tensor- magnetic resonance imaging data. The electrodes of intra-cranial EEG (iEEG) measurements were extracted from a co-registered computed tomography image. Goal function scan (GFS), minimum norm least squares (MNLS), standardized low resolution electromagnetic tomography (sLORETA) and spatio-temporal current dipole modeling inverse methods were then applied to the peak of the averaged ictal discharges EEG data. MNLS and sLORETA pointed to a single center of activity. Moving and rotating single dipole fits resulted in an explained variance of more than 97%. The non-invasive EEG source analysis methods localized at the border of the lesion and at the border of the iEEG electrodes which mainly received ictal discharges. Source orientation was towards the epileptogenic tissue. For the reconstructed superficial source, brain conductivity anisotropy and the lesion conductivity had only a minor influence, whereas a correct modeling of the highly conducting CSF compartment and the anisotropic skull was found to be important. The proposed FE forward modeling approach strongly simplifies meshing and reduces run-time (37 Milliseconds for one forward computation in the model with 3.1 Million unknowns), corroborating the practical feasibility of the

  15. Alternative disposal for Investigation Derived Wastes (IDW) containing low activity source material

    SciTech Connect

    Downey, H.T.; Majer, T.

    2007-07-01

    As part of a Remedial Investigation (RI) at a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Site, approximately 77,111 kg (85 tons) I would use the actual tons of investigation derived wastes (IDW) were generated from exploratory soil borings and as part of removal activities at a former drum burial area. Characterization of these materials indicated elevated concentrations of metals including uranium and thorium (source material). Concentrations of uranium and thorium were at levels less than 0.05% by mass, which is the threshold for exempt source material under Nuclear Regulatory Commission (NRC) regulations. Disposal of this material was evaluated as low-level radioactive waste and as exempt radioactive waste. The NRC has established a process for evaluation and review of exempt source material transfer and direct disposal in a Resource Conservation and Recovery Act (RCRA) landfill. These requests are normally approved if the dose to a member of the general public is unlikely to exceed 0.25 mSv per year (25 milli-rem per year). The soil was evaluated for disposal as exempt radioactive waste at a RCRA landfill, which included dose modeling to workers during transportation and disposal as well as potential dose to members of the public after closure of the disposal facility. These evaluations determined that the potential dose was very small, and review by the agreement state regulatory agency indicated that this disposal process should not result in any undue hazard to public health and safety or property. The advantage of this approach is that disposal of 77,111 kg (85 tons) of IDW at a RCRA landfill is estimated to result in a savings of $80,000 as compared to disposal as low-level radioactive waste. Alternative waste disposal of exempt source material provides more disposal options and can lead to significant cost savings. (authors)

  16. Comparison between high and low source activity seeds for I-125 permanent seed prostate brachytherapy.

    PubMed

    Masucci, Giuseppina Laura; Donath, David; Tétreault-Laflamme, Audrey; Carrier, Jean-François; Hervieux, Yannick; Larouche, Renée Xavière; Bahary, Jean-Paul; Taussky, Daniel

    2010-11-01

    To compare low (mean 0.44, SD ± 0.0163 mCi) with high source activity (0.61 ± 0.0178 mCi) in I(125) permanent seed brachytherapy regarding seed loss, dosimetric outcome, and toxicity. The study included 199 patients with prostate cancer treated by permanent seed brachytherapy alone: the first 105 with seeds of lower activity (first cohort), the following 94 with higher seed activity (second cohort). The V100, V150, V200, and D90 were analyzed on the CT scan 30 days after implantation (CTD30). The V100, V150, and D2 of the rectum were also calculated on CTD30. Seed loss was determined 30 days after implantation. Urinary toxicity was measured with the International Prostate Symptom Score (IPSS) questionnaire. Lower seed activity was associated with lower V150 and V200 (p = 0.01 and p ≤ 0.001, respectively) on CTD30. More patients had a V100 <90% and D90 <140 Gy in the lower activity cohort (p = 0.098 for D90 and p = 0.029 for V100) on CTD30. There was no difference between cohorts in dose to the rectum (p = 0.325-0.516) or difference in patients' IPSS score from baseline (p = 0.0.117-0.618), although there was a trend toward more urinary toxicity at 4 and 8 months for high activity seeds. Seed loss as a percentage of implanted seeds was not different (p = 0.324). Higher seed activity (I(125) ≥ 0.6 mCi) results in at least equal V100 and D90 on CTD30. However, dose inhomogeneity and a trend toward more urinary toxicity at 4 and 8 months after treatment may lead to a higher long-term urinary complications. Copyright © 2010 Elsevier Inc. All rights reserved.

  17. [Conjugated linolenic acids (CLnA, super CLA)--natural sources and biological activity].

    PubMed

    Białek, Agnieszka; Teryks, Marta; Tokarz, Andrzej

    2014-11-06

    Polyunsaturated fatty acids (PUFA) have a wide range of biological activity. Among them conjugated fatty acids are of great interest. Conjugated linoleic acids (CLA), which exert a multidirectional health-benefiting influence, and conjugated linolenic acids (CLnA, super CLA) are examples of this group of fatty acids. CLnA are a group of positional and geometric isomers of octadecatrienoic acid (C18:3), which possess double bonds at positions 9, 11, 13 or 8, 10, 12 of their chain. Some vegetable oils are rich sources of CLnA, e.g. bitter melon oil (from Momordica charantia seeds) and pomegranate oil (from Punica granatum seeds). The aim of this paper was to present information concerning natural sources and health-promoting activities of conjugated linolenic acids. The presented data reveal that conjugated linolenic acids may be very useful in prevention and treatment of many diseases, especially diabetes, arteriosclerosis , obesity and cancers (mammary, prostate and colon cancer). Among many potential mechanisms of their action, the fact that some CLnA are converted by oxidoreductases into CLA is very important. It seems to be very reasonable to conduct research concerning the possibility of CLnA use in prevention of many diseases.

  18. Time-frequency intracranial source localization of feedback-related EEG activity in hypothesis testing.

    PubMed

    Papo, David; Douiri, Abdel; Bouchet, Florence; Bourzeix, Jean-Claude; Caverni, Jean-Paul; Baudonnière, Pierre-Marie

    2007-06-01

    The neural correlates of the response to performance feedback have been the object of numerous neuroimaging studies. However, the precise timing and functional meaning of the resulting activations are poorly understood. We studied the electroencephalographic response time locked to positive and negative performance feedback in a hypothesis testing paradigm. The signal was convoluted with a family of complex wavelets. Intracranial sources of activity at various narrow-band frequencies were estimated in the 100- to 400-ms time window following feedback onset. Positive and negative feedback were associated to 1) early parahippocampo-cingular sources of alpha oscillations, more posteriorly located and long lasting for negative feedback and to 2) late partially overlapping neural circuits comprising regions in prefrontal, cingular, and temporal cortices but operating at feedback-specific latencies and frequencies. The results were interpreted in the light of neurophysiological models of feedback and were used to discuss methodological issues in the study of high-level cognitive functions, including reasoning and decision making.

  19. Medial temporal lobe activity during source retrieval reflects information type, not memory strength.

    PubMed

    Diana, Rachel A; Yonelinas, Andrew P; Ranganath, Charan

    2010-08-01

    The medial temporal lobes (MTLs) are critical for episodic memory but the functions of MTL subregions are controversial. According to memory strength theory, MTL subregions collectively support declarative memory in a graded manner. In contrast, other theories assert that MTL subregions support functionally distinct processes. For instance, one view is that perirhinal cortex (PRc) processes item information, parahippocampal cortex (PHc) processes context information, and the hippocampus binds item and context. Here, we report two experiments that tested competing predictions from these models. In these studies, subjects encoded color-word associations by imagining color either as a contextual association (context detail condition) or as a feature of the item to be encoded (item detail condition). Results showed that encoding color information as an item detail improved source recognition in amnesic patients with recollection deficits. Furthermore, event-related fMRI data from healthy subjects revealed PRc activation associated with successful retrieval of item details, whereas activation in the hippocampus and PHc was associated with recollection-based source retrieval. The qualitatively different patterns of results observed in PRc and hippocampus/PHc are inconsistent with a memory strength account and are consistent with the idea that different MTL regions process different types of episodic information.

  20. Personality-dependent dissociation of absolute and relative loss processing in orbitofrontal cortex.

    PubMed

    Fujiwara, Juri; Tobler, Philippe N; Taira, Masato; Iijima, Toshio; Tsutsui, Ken-ichiro

    2008-03-01

    A negative outcome can have motivational and emotional consequences on its own (absolute loss) or in comparison to alternative, better, outcomes (relative loss). The consequences of incurring a loss are moderated by personality factors such as neuroticism and introversion. However, the neuronal basis of this moderation is unknown. Here we investigated the neuronal basis of loss processing and personality with functional magnetic resonance imaging in a choice task. We separated absolute and relative financial loss by sequentially revealing the chosen and unchosen outcomes. With increasing neuroticism, activity in the left lateral orbitofrontal cortex (OFC) preferentially reflected relative rather than absolute losses. Conversely, with increasing introversion, activity in the right lateral OFC preferentially reflected absolute rather than relative losses. These results suggest that personality affects loss-related processing through the lateral OFC, and propose a dissociation of personality dimension and loss type on the neuronal level.