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Sample records for room irradiance spectra

  1. An artificial solar spectrum substantially alters plant development compared with usual climate room irradiance spectra.

    PubMed

    Hogewoning, Sander W; Douwstra, Peter; Trouwborst, Govert; van Ieperen, Wim; Harbinson, Jeremy

    2010-03-01

    Plant responses to the light spectrum under which plants are grown affect their developmental characteristics in a complicated manner. Lamps widely used to provide growth irradiance emit spectra which are very different from natural daylight spectra. Whereas specific responses of plants to a spectrum differing from natural daylight may sometimes be predictable, the overall plant response is generally difficult to predict due to the complicated interaction of the many different responses. So far studies on plant responses to spectra either use no daylight control or, if a natural daylight control is used, it will fluctuate in intensity and spectrum. An artificial solar (AS) spectrum which closely resembles a sunlight spectrum has been engineered, and growth, morphogenesis, and photosynthetic characteristics of cucumber plants grown for 13 d under this spectrum have been compared with their performance under fluorescent tubes (FTs) and a high pressure sodium lamp (HPS). The total dry weight of the AS-grown plants was 2.3 and 1.6 times greater than that of the FT and HPS plants, respectively, and the height of the AS plants was 4-5 times greater. This striking difference appeared to be related to a more efficient light interception by the AS plants, characterized by longer petioles, a greater leaf unfolding rate, and a lower investment in leaf mass relative to leaf area. Photosynthesis per leaf area was not greater for the AS plants. The extreme differences in plant response to the AS spectrum compared with the widely used protected cultivation light sources tested highlights the importance of a more natural spectrum, such as the AS spectrum, if the aim is to produce plants representative of field conditions.

  2. Measured Neutron Spectra and Dose Equivalents From a Mevion Single-Room, Passively Scattered Proton System Used for Craniospinal Irradiation.

    PubMed

    Howell, Rebecca M; Burgett, Eric A; Isaacs, Daniel; Price Hedrick, Samantha G; Reilly, Michael P; Rankine, Leith J; Grantham, Kevin K; Perkins, Stephanie; Klein, Eric E

    2016-05-01

    To measure, in the setting of typical passively scattered proton craniospinal irradiation (CSI) treatment, the secondary neutron spectra, and use these spectra to calculate dose equivalents for both internal and external neutrons delivered via a Mevion single-room compact proton system. Secondary neutron spectra were measured using extended-range Bonner spheres for whole brain, upper spine, and lower spine proton fields. The detector used can discriminate neutrons over the entire range of the energy spectrum encountered in proton therapy. To separately assess internally and externally generated neutrons, each of the fields was delivered with and without a phantom. Average neutron energy, total neutron fluence, and ambient dose equivalent [H* (10)] were calculated for each spectrum. Neutron dose equivalents as a function of depth were estimated by applying published neutron depth-dose data to in-air H* (10) values. For CSI fields, neutron spectra were similar, with a high-energy direct neutron peak, an evaporation peak, a thermal peak, and an intermediate continuum between the evaporation and thermal peaks. Neutrons in the evaporation peak made the largest contribution to dose equivalent. Internal neutrons had a very low to negligible contribution to dose equivalent compared with external neutrons, largely attributed to the measurement location being far outside the primary proton beam. Average energies ranged from 8.6 to 14.5 MeV, whereas fluences ranged from 6.91 × 10(6) to 1.04 × 10(7) n/cm(2)/Gy, and H* (10) ranged from 2.27 to 3.92 mSv/Gy. For CSI treatments delivered with a Mevion single-gantry proton therapy system, we found measured neutron dose was consistent with dose equivalents reported for CSI with other proton beamlines. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Spectra and Neutron Dosimetry Inside a PET Cyclotron Vault Room

    SciTech Connect

    Vega-Carrillo, Hector Rene; Mendez, Roberto; Iniguez, Maria Pilar; Marti-Climent, Joseph; Penuelas, Ivan; Barquero, Raquel

    2006-09-08

    The neutron field around a PET cyclotron was investigated during 18F radioisotope production with an 18 MeV proton beam. Pairs of thermoluminescent dosemeters, TLD600 and TLD700, were used as thermal neutron detector inside a Bonner Spheres Spectrometer to measure the neutron spectra at three different positions inside the cyclotron's vault room. Neutron spectra were also determined by Monte Carlo calculations. The hardest spectrum was observed in front of cyclotron target and the softest was noticed at the antipode of target. Neutron doses derived from the measured spectra vary between 11 and 377 mSv/{mu}A-h of proton integrated current, Doses were also measured with a single-moderator remmeter, with an active thermal neutron detector, whose response in affected by the radiation field in the vault room.

  4. Ultrafast excitonic room temperature nonlinearity in neutron irradiated quantum wells

    SciTech Connect

    Ten, S.; Williams, J.G.; Guerreiro, P.T.; Khitrova, G.; Peyghambarian, N.

    1997-01-01

    Sharp room temperature exciton features and complete recovery of the excitonic absorption with 21 ps time constant are demonstrated in neutron irradiated (Ga,Al)As/GaAs multiple quantum wells. Carrier lifetime reduction is consistent with the EL2 midgap defect which is efficiently generated by fast neutrons. Influence of gamma rays accompanying neutron irradiation is discussed. Neutron irradiation provides a straightforward way to control carrier lifetime in semiconductor heterostructures with minor deterioration of their excitonic properties. {copyright} {ital 1997 American Institute of Physics.}

  5. Fluorescence Spectra Of Corneal Tissue Under Excimer Laser Irradiation

    NASA Astrophysics Data System (ADS)

    Loree, Thomas R.; Johnson, Tamara M.; Birmingham, Brian S.; McCord, Roy C.

    1988-06-01

    The corneas of pigs' eyes were irradiated with ablative levels of 193, 248, and 308 nm and the spectra of the produced light recorded. In all cases there was an appreciable amount of uv light produced in the 300-400 nm band. The 193 nm irradiation exhibited a threshold at 0.5 J/cm2; markedly different spectra were produced below and above that threshold.

  6. Guide to solar reference spectra and irradiance models

    NASA Astrophysics Data System (ADS)

    Tobiska, W. Kent

    The international standard for determining solar irradiances was published by the International Standards Organization (ISO) in May 2007. The document, ISO 21348 Space Environment (natural and artificial) - Process for determining solar irradiances, describes the process for representing solar irradiances. We report on the next progression of standards work, i.e., the development of a guide that identifies solar reference spectra and irradiance models for use in engineering design or scientific research. This document will be produced as an AIAA Guideline and ISO Technical Report. It will describe the content of the reference spectra and models, uncertainties and limitations, technical basis, data bases from which the reference spectra and models are formed, publication references, and sources of computer code for reference spectra and solar irradiance models, including those which provide spectrally-resolved lines as well as solar indices and proxies and which are generally recognized in the solar sciences. The document is intended to assist aircraft and space vehicle designers and developers, heliophysicists, geophysicists, aeronomers, meteorologists, and climatologists in understanding available models, comparing sources of data, and interpreting engineering and scientific results based on different solar reference spectra and irradiance models.

  7. Principal Component Analysis of Arctic Solar Irradiance Spectra

    NASA Technical Reports Server (NTRS)

    Rabbette, Maura; Pilewskie, Peter; Gore, Warren J. (Technical Monitor)

    2000-01-01

    During the FIRE (First ISCPP Regional Experiment) Arctic Cloud Experiment and coincident SHEBA (Surface Heat Budget of the Arctic Ocean) campaign, detailed moderate resolution solar spectral measurements were made to study the radiative energy budget of the coupled Arctic Ocean - Atmosphere system. The NASA Ames Solar Spectral Flux Radiometers (SSFRs) were deployed on the NASA ER-2 and at the SHEBA ice camp. Using the SSFRs we acquired continuous solar spectral irradiance (380-2200 nm) throughout the atmospheric column. Principal Component Analysis (PCA) was used to characterize the several tens of thousands of retrieved SSFR spectra and to determine the number of independent pieces of information that exist in the visible to near-infrared solar irradiance spectra. It was found in both the upwelling and downwelling cases that almost 100% of the spectral information (irradiance retrieved from 1820 wavelength channels) was contained in the first six extracted principal components. The majority of the variability in the Arctic downwelling solar irradiance spectra was explained by a few fundamental components including infrared absorption, scattering, water vapor and ozone. PCA analysis of the SSFR upwelling Arctic irradiance spectra successfully separated surface ice and snow reflection from overlying cloud into distinct components.

  8. Principal Component Analysis of Arctic Solar Irradiance Spectra

    NASA Technical Reports Server (NTRS)

    Rabbette, Maura; Pilewskie, Peter; Gore, Warren J. (Technical Monitor)

    2000-01-01

    During the FIRE (First ISCPP Regional Experiment) Arctic Cloud Experiment and coincident SHEBA (Surface Heat Budget of the Arctic Ocean) campaign, detailed moderate resolution solar spectral measurements were made to study the radiative energy budget of the coupled Arctic Ocean - Atmosphere system. The NASA Ames Solar Spectral Flux Radiometers (SSFRs) were deployed on the NASA ER-2 and at the SHEBA ice camp. Using the SSFRs we acquired continuous solar spectral irradiance (380-2200 nm) throughout the atmospheric column. Principal Component Analysis (PCA) was used to characterize the several tens of thousands of retrieved SSFR spectra and to determine the number of independent pieces of information that exist in the visible to near-infrared solar irradiance spectra. It was found in both the upwelling and downwelling cases that almost 100% of the spectral information (irradiance retrieved from 1820 wavelength channels) was contained in the first six extracted principal components. The majority of the variability in the Arctic downwelling solar irradiance spectra was explained by a few fundamental components including infrared absorption, scattering, water vapor and ozone. PCA analysis of the SSFR upwelling Arctic irradiance spectra successfully separated surface ice and snow reflection from overlying cloud into distinct components.

  9. Blue photoluminescence enhancement in laser-irradiated 6H-SiC at room temperature

    SciTech Connect

    Wu, Yan; Ji, Lingfei Lin, Zhenyuan; Jiang, Yijian; Zhai, Tianrui

    2014-01-27

    Blue photoluminescence (PL) of 6H-SiC irradiated by an ultraviolet laser can be observed at room temperature in dark condition. PL spectra with Gaussian fitting curve of the irradiated SiC show that blue luminescence band (∼440 nm) is more pronounced than other bands. The blue PL enhancement is the combined result of the improved shallow N-donor energy level and the unique surface state with Si nanocrystals and graphene/Si composite due to the effect of photon energy input by the short-wavelength laser irradiation. The study can provide a promising route towards the preparation of well-controlled blue photoluminescence material for light-emitting devices.

  10. On designing room sheilding for total-body irradiation

    SciTech Connect

    Barish, R.J.

    1996-05-01

    When designing shielding for total-body irradiation as an additional modality of treatment in an ordinary radiation therapy room, the extended treatment distance used for these patients greatly increases the workload because of the inverse-square factor. In a seeming contradiction to logic, for a facility with an exterior wall in the path of one lateral primary beam, and a restricted area behind the other primary wall, the overall shielding requirements are lower if the TBI patients are treated with the machine oriented toward the occupied interior. 4 refs.

  11. Valence photoelectron spectra of an electron-beam-irradiated C60 film

    NASA Astrophysics Data System (ADS)

    Onoe, Jun; Nakao, Aiko; Hida, Akira

    2004-10-01

    Valence photoelectron spectra of an electron-beam (EB) irradiated C60 film, which exhibited metallic electron-transport properties in air at room temperature, are presented. The electronic structure of the C60 film became closer to that of graphite as the EB-irradiation time increased, and its density of states around the Fermi level was eventually greater than for the graphite. This suggests that the electronic structure of the C60 film changed from a semiconductor to a semimetal and/or metal by EB irradiation. Interestingly, the electronic structure remained metallic even after five days of air exposure, which is the reason for the metallic electron-transport property in our previous report [Appl. Phys. Lett. 82, 595 (2003)].

  12. Cross-linking of polytetrafluoroethylene during room-temperature irradiation

    SciTech Connect

    Pugmire, David L; Wetteland, Chris J; Duncan, Wanda S; Lakis, Rollin E; Schwartz, Daniel S

    2008-01-01

    Exposure of polytetrafluoroethylene (PTFE) to {alpha}-radiation was investigated to detennine the physical and chemical effects, as well as to compare and contrast the damage mechanisms with other radiation types ({beta}, {gamma}, or thermal neutron). A number of techniques were used to investigate the chemical and physical changes in PTFE after exposure to {alpha}-radiation. These techniques include: Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and fluorescence spectroscopy. Similar to other radiation types at low doses, the primary damage mechanism for the exposure of PTFE to {alpha}-radiation appears to be chain scission. Increased doses result in a change-over of the damage mechanism to cross-linking. This result is not observed for any radiation type other than {alpha} when irradiation is performed at room temperature. Finally, at high doses, PTFE undergoes mass-loss (via smallfluorocarbon species evolution) and defluorination. The amount and type of damage versus sample depth was also investigated. Other types of radiation yield damage at depths on the order of mm to cm into PTFE due to low linear energy transfer (LET) and the correspondingly large penetration depths. By contrast, the {alpha}-radiation employed in this study was shown to only induce damage to a depth of approximately 26 {mu}m, except at very high doses.

  13. Using room temperature current noise to characterize single molecular spectra.

    PubMed

    Vasudevan, Smitha; Ghosh, Avik W

    2014-03-25

    We propose a way to use room temperature random telegraph noise to characterize single molecules adsorbed on a backgated silicon field-effect transistor. The overlap of molecule and silicon electronic wave functions generates a set of trap levels that impose their unique scattering signatures on the voltage-dependent current noise spectrum. Our results are based on numerical modeling of the current noise, obtained by coupling a density functional treatment of the trap placement within the silicon band gap, a quantum kinetic treatment of the output current, and a Monte Carlo evaluation of the trap occupancy under resonance. As an illustrative example, we show how we can extract molecule-specific "fingerprints" of four benzene-based molecules directly from a frequency-voltage colormap of the noise statistics. We argue that such a colormap carries detailed information about the trap dynamics at the Fermi energy, including the presence of correlated interactions, observed experimentally in backgated carbon nanotubes.

  14. Particle LET spectra from microelectronics packaging materials subjected to neutron and proton irradiation

    NASA Astrophysics Data System (ADS)

    Browning, J. S.; Holtkamp, D. B.

    1988-12-01

    Cumulative fractions for LET spectra were measured for particles ejected from microelectronics packaging materials subjected to neutron and proton irradiation. The measurements for the neutron irradiation compare well with Monte Carlo theoretical calculations. The spectra can be used to access microelectronics vulnerabilities in strategic-nuclear- weapon, space-trapped, and neutral-beam directed-energy particle environments.

  15. Formation of rutile fasciculate zone induced by sunlight irradiation at room temperature and its hemocompatibility.

    PubMed

    Zhang, Xuan-Hui; Zheng, Xiang; Cheng, Yuan; Li, Guo-Hua; Chen, Xiao-Ping; Zheng, Jian-Hui

    2013-08-01

    The fasciculate zone of phase pure rutile was fabricated under sunlight irradiation at room temperature, using titanium tetrachloride as a sole precursor. The crystal phase, morphology and microstructure, and optical absorption behavior of the samples were characterized by X-ray Diffraction, High-Resolution Transmission Electron Microscope (HRTEM) and UV-vis Diffuse Reflectance Spectra (DRS), respectively. XRD results show that the crystal phase of the sample is composed of rutile only, and a lattice distortion displays in the crystallite of the sample. HRTEM results show that the morphology of rutile particle is fasciculate zone constituted of nanoparticles with a diameter of 4-7 nm, and these particles grow one by one and step by step. The pattern of the selected area electron diffraction of the sample is Kikuchi type, which can be attributed to the predominant orientation growth of rutile nanoparticles along [001] induced by sunlight irradiation. DRS results show that the absorption threshold of the sample is 415 nm, corresponding to the band gap energy of 2.99 eV, which is lower than the band gap energy of rutile, 3.03 eV. Blood compatibility measurement shows that the sample has no remarkable effect on hemolytic and coagulation activity. The percent hemolysis of red blood cells is less than 5% even treated with a big dosage of the fasciculate rutile and under UV irradiation, and there are no obvious changes of plasma recalcification time after the rutile treatment. Thus, the novel structure of rutile fasciculate has low potential toxicity for blood and is hemocompatibility safe. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Determination of neutron energy spectra inside a water phantom irradiated by 64 MeV neutrons.

    PubMed

    Herbert, M S; Brooks, F D; Allie, M S; Buffler, A; Nchodu, M R; Makupula, S A; Jones, D T L; Langen, K M

    2007-01-01

    A NE230 deuterated liquid scintillator detector (25 mm diameter x 25 mm) has been used to investigate neutron energy spectra as a function of position in a water phantom under irradiation by a quasi-monoenergetic 64 MeV neutron beam. Neutron energy spectra are obtained from measurements of pulse height spectra by the NE230 detector using the Bayesian unfolding code MAXED. The experimentally measured energy spectra are compared with spectra calculated by Monte Carlo simulation using the code MCNPX.

  17. Eggcrate UV: a whole ceiling upper-room ultraviolet germicidal irradiation system for air disinfection in occupied rooms.

    PubMed

    Linnes, J C; Rudnick, S N; Hunt, G M; McDevitt, J J; Nardell, E A

    2014-04-01

    A novel whole ceiling upper-room ultraviolet germicidal irradiation (UVGI) system [eggcrate ultraviolet (UV)] has been developed that incorporates open-cell 'eggcrate'-suspended ceiling panels and bare UV lamps with a ceiling fan. Upper-room UVGI is more effective for air disinfection than mechanical ventilation at much lower installation and operating costs. Conventional upper-room UVGI fixtures employ multiple tightly spaced horizontal louvers to confine UV to the upper-room. These louvered fixtures protect occupants in the lower-room from UV-induced eye and skin irritation, but at a major cost to fixture efficiency. Using a lamp and ballast from a conventional upper-room UVGI fixture in the eggcrate UV system, the germicidal efficacy was markedly improved even though the UV radiation emitted by the lamp was unchanged. This fundamental change in the application of upper-room UVGI air disinfection should permit wider, more effective application of UVGI globally to reduce the spread of airborne infection.

  18. Semiconducting Properties of Swift Au Ion-Irradiated ZnO Thin Films at Room Temperature

    NASA Astrophysics Data System (ADS)

    Kwon, Sera; Park, Hyun-Woo; Chung, Kwun-Bum

    2017-02-01

    The semiconducting properties of Au ion-irradiated ZnO thin films were investigated as a function of ion irradiation dose at room temperature. The Au ion irradiation was conducted with acceleration energy of 130 MeV in the ion dose range from 1 × 1011 to 5 × 1012 ions/cm2. The physical properties showed no change regardless of the Au ion irradiation dose; however, the electrical properties of Au ion-irradiated ZnO thin films changed, depending on the Au ion irradiation dose. The electronic structure drastically changed with the evolution of hybridized molecular orbital structure for the conduction band and band edge states below the conduction band. These remarkable changes in electronic structure correlate with changes in electrical properties, such as carrier concentration and mobility.

  19. Influence of the physical structure of irradiated starches on their electron spin resonance spectra kinetics

    SciTech Connect

    Raffi, J.J.; Agnel, J.P.L.

    1983-06-23

    This study deals with the shape and kinetic changes of the ESR spectra of eight irradiated starchs, from several hours to several months after ..gamma..-irradiation. Whatever the origin and water content of the starches two major radicals or groups of radicals are observed. The kinetic law depends on the water content; two main zones are pointed out which are relative to the amorphous and crystalline parts of starches.

  20. Permanent optical doping of amorphous metal oxide semiconductors by deep ultraviolet irradiation at room temperature

    SciTech Connect

    Seo, Hyungtak; Cho, Young-Je; Bobade, Santosh M.; Park, Kyoung-Youn; Choi, Duck-Kyun; Kim, Jinwoo; Lee, Jaegab

    2010-05-31

    We report an investigation of two photon ultraviolet (UV) irradiation induced permanent n-type doping of amorphous InGaZnO (a-IGZO) at room temperature. The photoinduced excess electrons were donated to change the Fermi-level to a conduction band edge under the UV irradiation, owing to the hole scavenging process at the oxide interface. The use of optically n-doped a-IGZO channel increased the carrier density to approx10{sup 18} cm{sup -3} from the background level of 10{sup 16} cm{sup -3}, as well as the comprehensive enhancement upon UV irradiation of a-IGZO thin film transistor parameters, such as an on-off current ratio at approx10{sup 8} and field-effect mobility at 22.7 cm{sup 2}/V s.

  1. Health physics aspects in treatment rooms after 18-MV X-ray irradiations.

    PubMed

    Kalef-Ezra, John A

    2011-09-01

    Delayed activation products contribute to the exposure of the staff operating high-energy accelerators. Induced activity was studied in a treatment room following 18-MV X-ray irradiations using a hand-held system that allows both dose rate measurements and spectroscopic analysis. The major activation products and the corresponding nuclear reactions were identified. At the majority of the studied locations, β(+) emitters were the main short-term dose contributors. The time variation of the absorbed dose rate in a treatment room during the first 20-min post-irradiation was represented by the sum of two exponential components with half-lives of 1-2 min and either 4 or 10 min, depending on the location in the room. Components with a half-life of hours or days contribute <1 % to the initial dose rate. The activation of some accessories, such as iron filters and portal imagers, deserve special attention. The collection of such data with the proposed method allows the development of optimised working protocols at each treatment room.

  2. Fourier transform infrared spectra of drying oils treated by irradiation.

    PubMed

    Wang, Yi; Wang, Qin; Artz, William E; Padua, Graciela W

    2008-05-14

    Drying oils, such as linseed oil and tung oil, have the potential as coating materials to improve barrier properties of biobased packaging films. Oil drying is a chemical reaction in which polyunsaturated fatty acids undergo autoxidation. During drying, oils polymerize and form water-resistant films. However, drying rates tend to be too slow for practical applications. Metal driers are used in the paint industry to accelerate drying, but often driers are not safe for food contact. The objective of this work was to investigate the effect of ionizing radiation on the oxidation or drying rate of drying oils. The effect of irradiation dose on the drying rate of linseed and tung oils was monitored by FTIR spectroscopy. The peak at 3010 cm (-1) was found to be a useful index of oxidation rate. The decrease in peak intensity with time was fitted with exponential functions of the form Abs = Abs 0 exp (- t/ k), where Abs 0 is the initial absorbance and 1/ k is the rate constant for the oxidation process. Values for k were 9.91 ( R (2) = 0.98), 6.59 ( R (2) = 0.95)n and 6.44 ( R (2) = 0.97) for radiation levels of 0, 50, and 100 kGy, respectively. The k values suggested that the oxidation rate increased as the radiation dose increased from 0 to 50 kGy. A further increase to 100 kGy had only a limited effect.

  3. Irradiation effect on infrared spectra of LiF:OH crystals: Theoretical modeling

    NASA Astrophysics Data System (ADS)

    Inerbaev, Talgat; Dauletbekova, Alma; Abdrakhmetova, Ainash

    2017-09-01

    First-principles simulations of LiF:OH crystal infrared absorption spectra were performed using density functional calculations with periodic boundary conditions to explain the yet unclear nature of experimentally observed irradiation-induced absorption bands in infrared spectra in frequency range 1900-2200 and 1000-1300 cm-1. To model the irradiation effect, various defect structures were explored. Simulations demonstrated that a new type of defect should be taken into consideration to explain the infrared spectra features. Specific new defect is formed by one fluorine atom displaced from the lattice site into the interstitial position due to irradiation. At the same time, hydrogen atom, produced by of hydroxyl group radiolysis decay, occupies position between fluorine atoms in anionic (Fa) and interstitial (Fi) positions forming covalently bonded negatively charged defect, referred to as F-H-F complex. Asymmetrical stretching oscillation of this defect complex is responsible for infrared absorption band near 2200 cm-1. Features in the infrared spectra observed near 1000 cm-1 originate from two types of vibrations: bending vibrations of proposed new defect complex and oscillations of hydrogen ions in the anionic positions. Defect formed by negatively charged hydrogen ion in interstitial position results infrared absorption band at 1288 cm-1. The experimentally observed decrease of the oscillation frequency near 2200 cm-1 under further irradiation is associated with increase of negative charge value on the proposed defect complex caused by F-centers creation.

  4. EPR spectra induced by gamma-irradiation of some dry medical herbs

    NASA Astrophysics Data System (ADS)

    Yordanov, N. D.; Lagunov, O.; Dimov, K.

    2009-04-01

    The radiation-induced EPR spectra in some medical herbs are reported. The samples studied are: (i) leaves of nettle, common balm, peppermint and thyme; (ii) stalks of common balm, thyme, milfoil, yarrow and marigold; (iii) blossoms of yarrow and marigold; (iv) blossoms and leaves of hawthorn and tutsan; and (v) roots of common valerian, nettle, elecampane (black and white), restharrows and carlina. Before irradiation all samples exhibit one weak anisotropic singlet EPR line with effective g-value of 2.0050±0.0002. The radiation-induced spectra fall into three groups. EPR spectra of irradiated blossoms of yarrow and marigold, stalks of common balm, thyme, tutsan and yarrow as well as roots of common valerian, nettle and elecampane (black and white) show "cellulose-like" EPR spectrum typical for irradiated plants. It is characterized by one intense central line with g=2.0050±0.0005 and two weak satellite lines situated ca. 30 G left and right to it. EPR spectra of gamma-irradiated restharrows and carlina are complex. They may be represented by one triplet corresponding to the "cellulose-like" EPR spectrum, one relatively intense singlet, situated in the center of the spectrum, and five weak additional satellite lines left and right to the center. The last spectrum was assigned as "carbohydrate-like" type. Only one intense EPR singlet with g=2.0048±0.0005 was recorded after irradiation of leaves of nettle and common balm. The lifetime of the radiation-induced EPR spectra was followed for a period of 3 months.

  5. Simulation of Ginger EPR Spectra Obtained by X-Irradiation:Quantum Approach

    NASA Astrophysics Data System (ADS)

    Laachir, S.; Moussetad, M.; Adhiri, R.; Fahli, A.; Aboulfatah, M.; Mikou, M.

    2005-08-01

    The ginger sample has been exposed to X-rays at cumulative doses. The foodstuffs irradiation is used in particular to improve their hygienic qualities and increase their shelf lives. This process has been approved by various international organizations: FAO -- AIEA -- WHO. In the present work, we propose to reproduce by simulation, based on a quantum approach, of the ESR (Electron Spin Resonance) spectra. The semi-classical approach is valid for a simple system, but not for a complex system such as an atom with hyperfine structure. In this case a quantum approach, based on spin Hamiltonian, is essential to interpret the ESR spectra. The main result is that the simulated spectra are in good agreement with the experimental ones obtained before and after irradiation.

  6. Measurement and calculation of characteristic prompt gamma ray spectra emitted during proton irradiation.

    PubMed

    Polf, J C; Peterson, S; McCleskey, M; Roeder, B T; Spiridon, A; Beddar, S; Trache, L

    2009-11-21

    In this paper, we present results of initial measurements and calculations of prompt gamma ray spectra (produced by proton-nucleus interactions) emitted from tissue equivalent phantoms during irradiations with proton beams. Measurements of prompt gamma ray spectra were made using a high-purity germanium detector shielded either with lead (passive shielding), or a Compton suppression system (active shielding). Calculations of the spectra were performed using a model of both the passive and active shielding experimental setups developed using the Geant4 Monte Carlo toolkit. From the measured spectra it was shown that it is possible to distinguish the characteristic emission lines from the major elemental constituent atoms (C, O, Ca) in the irradiated phantoms during delivery of proton doses similar to those delivered during patient treatment. Also, the Monte Carlo spectra were found to be in very good agreement with the measured spectra providing an initial validation of our model for use in further studies of prompt gamma ray emission during proton therapy.

  7. Trapping of hydrogen atoms in X-irradiated salts at room temperature and the decay kinetics

    NASA Technical Reports Server (NTRS)

    May, C. E.; Philipp, W. H.; Marsik, S. J.

    1974-01-01

    The salts (hypophosphites, formates, a phosphite, a phosphate, and an oxalate) were X-irradiated, whereby hydrogen formed chemically by a radiolytic process becomes trapped in the solid. By room temperature vacuum extraction, the kinetics for the evolution of this trapped hydrogen was studied mass spectrometrically. All salts except two exhibited second-order kinetics. The two exceptions (NaH2PO2(H2O) and K2HPO4) showed first-order kinetics. Based on experimental results, the escape of hydrogen involves three steps: the diffusion of hydrogen atoms from the bulk to the surface, association of these atoms on the surface (rate controlling step for second-order hydrogen evolution), and the desorption of molecular hydrogen from the surface. The hydrogen does not escape if the irradiated salt is stored in air, apparently because adsorbed air molecules occupy surface sites required in the escape mechanism.

  8. Characterization of microstructure in hydrogen ion irradiated vanadium at room temperature and the microstructural evolution during post-irradiation annealing

    SciTech Connect

    Gao, Jin; Cui, Lijuan; Wan, Farong

    2016-01-15

    The microstructure of pure vanadium after hydrogen ion irradiation at room temperature to a fluence of 1 × 10{sup 17} ions/cm{sup 2} (and 5 × 10{sup 16} ions/cm{sup 2}) was investigated by transmission electron microscopy (TEM). Small dislocation loops (black spots) and cavities are formed after the irradiation. The nature and Burgers vector of dislocation loops formed in vanadium was characterized using g·b technique and inside–outside method. Interstitial dislocation loops with Burgers vector of 1/2 < 111 > predominantly formed with less than 10% of 1/2 < 110 > type. No < 100 > type or vacancy type dislocation loop formed. The microstructural evolution during the annealing process was also studied. Density and size of dislocation loops changed sharply when the annealing temperature was lifted up to 450 °C. When the annealing temperature was higher than 500 °C, bubble coalescence occurred with some large hydrogen bubbles formed. - Highlights: • Interstitial dislocation loops with Burgers vector of 1/2<111> were predominant. • Less than 10% of 1/2<110> dislocation loops were present in pure vanadium. • No <100> or vacancy type loops were present in pure vanadium. • Density and size of dislocation loops changed sharply at temperature above 450 °C. • Bubble coalescence occurred when annealing temperature was higher than 500 °C.

  9. Fluorescence spectra of blood plasma treated with ultraviolet irradiation in vivo

    NASA Astrophysics Data System (ADS)

    Zalesskaya, G. A.; Maslova, T. O.

    2010-09-01

    We have studied the fluorescence spectra of blood plasma from patients with acute coronary syndrome, and also the effect of therapeutic doses of in vivo ultraviolet blood irradiation (UBI) on the spectra. We have established that the maxima in the fluorescence spectra of the original plasma samples, obtained from unirradiated blood, are located in the wavelength interval 330-340 nm, characteristic for the fluorescence of tryptophan residues. In extracorporeal UBI ( λ = 254 nm), we observed changes in the shape and also both a blue and a red shift in the maxima of the fluorescence spectra, differing in magnitude for blood plasma samples from different patients in the test group. We show that UBI-initiated changes in the fluorescence spectra of the plasma depend on the original pathological disturbances of metabolite levels, and also on the change in the oxygen-transport function of the blood and the acid-base balance, affecting the oxidative stability of the plasma. We have concluded that UV irradiation, activating buffer systems in the blood, has an effect on the universal and specific interactions of the tryptophan residue with the amino acid residues and water surrounding it.

  10. Infrared Spectra of Acetylene Diluted in Solid Nitrogen upon Irradiation with Vacuum Ultraviolet Light and Electrons

    NASA Astrophysics Data System (ADS)

    Wu, Yu-Jong; Chuang, Shiang-Jiun; Chen, Sian-Cong; Huang, Tzu-Ping

    2014-05-01

    Infrared spectra and chemical reactions of acetylene diluted in solid nitrogen at 10 K upon irradiation with vacuum ultraviolet (VUV) light and energetic electrons were investigated in separate experiments. Irradiation of the matrix sample with VUV light peaking at 160 and 121.6 nm yielded simple products, including C2H, CN, and isomers of C2N2. In contrast, electron irradiation of a similar sample generated N3, C2H, and various nitriles. The reaction mechanisms for photolysis and radiolysis of the matrix samples are discussed. Our results may help explain the distribution of trace species detected in the atmosphere of Titan. In addition, the UV absorption spectrum of the electron-bombarded icy sample was obtained and might be useful for future spectral investigations of Pluto by New Horizons.

  11. Methods Development for Spectral Simplification of Room-Temperature Rotational Spectra

    NASA Astrophysics Data System (ADS)

    Kent, Erin B.; Shipman, Steven

    2014-06-01

    Room-temperature rotational spectra are dense and difficult to assign, and so we have been working to develop methods to accelerate this process. We have tested two different methods with our waveguide-based spectrometer, which operates from 8.7 to 26.5 GHz. The first method, based on previous work by Medvedev and De Lucia, was used to estimate lower state energies of transitions by performing relative intensity measurements at a range of temperatures between -20 and +50 °C. The second method employed hundreds of microwave-microwave double resonance measurements to determine level connectivity between rotational transitions. The relative intensity measurements were not particularly successful in this frequency range (the reasons for this will be discussed), but the information gleaned from the double-resonance measurements can be incorporated into other spectral search algorithms (such as autofit or genetic algorithm approaches) via scoring or penalty functions to help with the spectral assignment process. I.R. Medvedev, F.C. De Lucia, Astrophys. J. 656, 621-628 (2007).

  12. Ultraviolet spectral reflectance of ceiling tiles, and implications for the safe use of upper-room ultraviolet germicidal irradiation.

    PubMed

    Wengraitis, Stephen; Reed, Nicholas G

    2012-01-01

    Ultraviolet germicidal irradiation can be used to prevent airborne transmission of infectious diseases. A common application is to irradiate upper-room areas, by passing air from the lower room into the irradiated zone. Well-designed systems do not expose people directly; however, some UV radiation may be reflected off ceiling tiles and wall paints into the lower room. Lower room exposure should be limited to the American Conference of Governmental Industrial Hygienists threshold limit value of 6 mJ·cm(-2) of 254 nm radiation per day. To limit the lower room exposure, the reflectance of upper-room surfaces must not be high. The reflective properties of wall paints have been studied, but less is known about the UV reflectance of ceiling tiles. Using a double monochromator spectroradiometer and an integrating sphere reflectance attachment, the UV spectral reflectance of 37 ceiling tiles was measured from 200 to 400 nm. The reflectances varied from 0.020 to 0.822 in this range, and from 0.035 to 0.459 at 254 nm, the main wavelength emitted by upper room low-pressure mercury germicidal lamps. These data were then used to estimate an 8 h exposure based on several simplified workplace scenarios. The implications for workplace safety are then discussed. © 2012 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2012 The American Society of Photobiology.

  13. Radiation effects on microstructure and hardness of a titanium aluminide alloy irradiated by helium ions at room and elevated temperatures

    NASA Astrophysics Data System (ADS)

    Wei, Tao; Zhu, Hanliang; Ionescu, Mihail; Dayal, Pranesh; Davis, Joel; Carr, David; Harrison, Robert; Edwards, Lyndon

    2015-04-01

    A 45XD TiAl alloy possessing a lamellar microstructure was irradiated using 5 MeV helium ions to a fluence of 5 × 1021 ion m-2 (5000 appm) with a dose of about 1 dpa (displacements per atom). A uniform helium ion stopping damage region about 17 μm deep from the target surface was achieved by applying an energy degrading wheel. Radiation damage defects including helium-vacancy clusters and small helium bubbles were found in the microstructure of the samples irradiated at room temperature. With increasing irradiation temperature to 300 °C and 500 °C helium bubbles were clearly observed in both the α2 and γ phases of the irradiated microstructure. By means of nanoindentation significant irradiation hardening was measured. For the samples irradiated at room temperature the hardness increased from 5.6 GPa to 8.5 GPa and the irradiation-hardening effect reduced to approximately 8.0 GPa for the samples irradiated at 300 °C and 500 °C.

  14. Charge transfer efficiency in a p-channel CCD irradiated cryogenically and the impact of room temperature annealing

    NASA Astrophysics Data System (ADS)

    Gow, J. P. D.; Murray, N. J.; Wood, D.; Burt, D.; Hall, D. J.; Dryer, B.; Holland, A. D.

    2016-08-01

    It is important to understand the impact of the space radiation environment on detector performance, thereby ensuring that the optimal operating conditions are selected for use in flight. The best way to achieve this is by irradiating the device using appropriate mission operating conditions, i.e. holding the device at mission operating temperature with the device powered and clocking. This paper describes the Charge Transfer Efficiency (CTE) measurements made using an e2v technologies p-channel CCD204 irradiated using protons to the 10 MeV equivalent fluence of 1.24×109 protons.cm-2 at 153 K. The device was held at 153 K for a period of 7 days after the irradiation before being allowed up to room temperature where it was held at rest, i.e. unbiased, for twenty six hours to anneal before being cooled back to 153 K for further testing, this was followed by a further one week and three weeks of room temperature annealing each separated by further testing. A comparison to results from a previous room temperature irradiation of an n-channel CCD204 is made using assumptions of a factor of two worse CTE when irradiated under cryogenic conditions which indicate that p-channel CCDs offer improved tolerance to radiation damage when irradiated under cryogenic conditions.

  15. Irradiation tests of ITER candidate Hall sensors using two types of neutron spectra.

    PubMed

    Ďuran, I; Bolshakova, I; Viererbl, L; Sentkerestiová, J; Holyaka, R; Lahodová, Z; Bém, P

    2010-10-01

    We report on irradiation tests of InSb based Hall sensors at two irradiation facilities with two distinct types of neutron spectra. One was a fission reactor neutron spectrum with a significant presence of thermal neutrons, while another one was purely fast neutron field. Total neutron fluence of the order of 10(16) cm(-2) was accumulated in both cases, leading to significant drop of Hall sensor sensitivity in case of fission reactor spectrum, while stable performance was observed at purely fast neutron spectrum. This finding suggests that performance of this particular type of Hall sensors is governed dominantly by transmutation. Additionally, it further stresses the need to test ITER candidate Hall sensors under neutron flux with ITER relevant spectrum.

  16. Irradiation tests of ITER candidate Hall sensors using two types of neutron spectra

    SciTech Connect

    Duran, I.; Viererbl, L.; Lahodova, Z.; Sentkerestiova, J.; Bem, P.

    2010-10-15

    We report on irradiation tests of InSb based Hall sensors at two irradiation facilities with two distinct types of neutron spectra. One was a fission reactor neutron spectrum with a significant presence of thermal neutrons, while another one was purely fast neutron field. Total neutron fluence of the order of 10{sup 16} cm{sup -2} was accumulated in both cases, leading to significant drop of Hall sensor sensitivity in case of fission reactor spectrum, while stable performance was observed at purely fast neutron spectrum. This finding suggests that performance of this particular type of Hall sensors is governed dominantly by transmutation. Additionally, it further stresses the need to test ITER candidate Hall sensors under neutron flux with ITER relevant spectrum.

  17. Photoluminescence emission spectra of Makrofol® DE 1-1 upon irradiation with ultraviolet radiation

    NASA Astrophysics Data System (ADS)

    El Ghazaly, M.; Aydarous, Abdulkadir

    Photoluminescence (PL) emission spectra of Makrofol® DE 1-1 (bisphenol-A based polycarbonate) upon irradiation with ultraviolet radiation of different wavelengths were investigated. The absorption-and attenuation coefficient measurements revealed that the Makrofol® DE 1-1 is characterized by high absorbance in the energy range 6.53-4.43 eV but for a lower energy than 4.43 eV, it is approximately transparent. Makrofol® DE 1-1 samples were irradiated with ultraviolet radiation of wavelength in the range from 250 (4.28 eV) to 400 (3.10 eV) nm in step of 10 nm and the corresponding photoluminescence (PL) emission spectra were measured with a spectrofluorometer. It is found that the integrated counts and the peak height of the photoluminescence emission (PL) bands are strongly correlated with the ultraviolet radiation wavelength. They are increased at the ultraviolet radiation wavelength 280 nm and have maximum at 290 nm, thereafter they decrease and diminish at 360 nm of ultraviolet wavelength. The position of the PL emission band peak was red shifted starting from 300 nm, which increased with the increase the ultraviolet radiation wavelength. The PL bandwidth increases linearly with the increase of the ultraviolet radiation wavelength. When Makrofol® DE 1-1 is irradiated with ultraviolet radiation of short wavelength (UVC), the photoluminescence emission spectra peaks also occur in the UVC but of a relatively longer wavelength. The current new findings should be considered carefully when using Makrofol® DE 1-1 in medical applications related to ultraviolet radiation.

  18. Observation of changes in ion beam induced luminescence spectra from organics during focused microbeam irradiation

    NASA Astrophysics Data System (ADS)

    Kada, Wataru; Kawabata, Shunsuke; Satoh, Takahiro; Sakai, Makoto; Parajuli, Raj Kumar; Yamada, Naoto; Koka, Masashi; Miura, Kenta; Hanaizumi, Osamu; Kamiya, Tomihiro

    2017-08-01

    Continuous measurement of ion beam induced luminescence (IBIL) spectra was demonstrated with organic targets of nicotinamide adenine dinucleotide (NADH), tryptophan, riboflavin, and a polycyclic aromatic hydrocarbon (PAH), which are typically used as markers of biological contaminants in airborne particles. A 3 MeV external proton microbeam from a single-ended accelerator at QST/Takasaki was used to probe for changes in the IBIL spectrum using micro-optics sharing a focal point with the microprobe. We find that the decay of IBIL spectra from NADH and riboflavin varied by target organic species. Moreover, new peaks in the IBIL spectrum were recorded by continuous IBIL spectroscopy from the PAH target after destruction of a peak originally obtained in the initial measurement. These results suggest that IBIL monitoring can detect changes in the chemical composition of organics under focused beam irradiation.

  19. Minimizing the exposure of airborne pathogens by upper-room ultraviolet germicidal irradiation: an experimental and numerical study

    PubMed Central

    Yang, Y.; Chan, W. Y.; Wu, C. L.; Kong, R. Y. C.; Lai, A. C. K.

    2012-01-01

    There has been increasing interest in the use of upper-room ultraviolet germicidal irradiation (UVGI) because of its proven effectiveness in disinfecting airborne pathogens. An improved drift flux mathematical model is developed for optimizing the design of indoor upper-room UVGI systems by predicting the distribution and inactivation of bioaerosols in a ventilation room equipped with a UVGI system. The model takes into account several bacteria removal mechanisms such as convection, turbulent diffusion, deposition and UV inactivation. Before applying the model, the natural die-off rate and susceptibility constants of bioaerosols were measured experimentally. Two bacteria aerosols, Escherichia coli and Serratia marcescens, were tested for this purpose. It was found out that the general decay trend of the bioaerosol concentration predicted by the numerical model agrees well with the experimental measurements. The modelling results agree better with experimental observations for the case when the UVGI inactivation mechanism dominates at the upper-room region than for the case without UVGI. The numerical results also illustrate that the spatial distribution of airborne bacteria was influenced by both air-flow pattern and irradiance distribution. In addition to predicting the local variation of concentration, the model assesses the overall performance of an upper-room UVGI system. This model has great potential for optimizing the design of indoor an upper-room UVGI systems. PMID:22809847

  20. Room temperature preparation of Pt-decorated MWCNTs by using proton beam irradiation

    NASA Astrophysics Data System (ADS)

    Kim, Yeong-Joon; Lee, Yoon Ji; Song, Jae Hee

    2016-09-01

    We present a facile one-pot preparation route for the production of multiwalled carbon nanotube (MWCNT)-Pt nanoparticle composites in an aqueous solution at room temperature by using proton beam irradiation process without the addition of any reducing reagents. We utilized hexade-cyltrimethylammonium bromide (CTAB)-stabilized pristine and thiol-functionalized MWCNTs for the synthesis of MWCNT-Pt nanoparticle composites and compared the deposition trends of the platinum nanoparticles onto the surfaces of pristine MWCNTs and surface-modified MWCNTs, respectively. Thiolated MWCNTs were densely and uniformly decorated with Pt nanoparticles while pristine MWCNTs were not. The Pt nanostructures on the surfaces of MWCNTs were spherical, and the average diameter was in the range of ~2 nm. Also, two different metal precursors, H2PtCl6 and Na2PtCl6, were used to find any distinguishable decoration patterns on the surface-modified MWCNTs; however, the deposition patterns were observed to be not very different.

  1. Polymerization of room-temperature ionic liquid monomers by electron beam irradiation with the aim of fabricating three-dimensional micropolymer/nanopolymer structures.

    PubMed

    Minamimoto, H; Irie, H; Uematsu, T; Tsuda, T; Imanishi, A; Seki, S; Kuwabata, S

    2015-04-14

    A novel method for fabricating microsized and nanosized polymer structures from a room-temperature ionic liquid (RTIL) on a Si substrate was developed by the patterned irradiation of an electron beam (EB). An extremely low vapor pressure of the RTIL, 1-allyl-3-ethylimidazolium bis((trifluoromethane)sulfonyl)amide, allows it to be introduced into the high-vacuum chamber of an electron beam apparatus to conduct a radiation-induced polymerization in the nanoregion. We prepared various three-dimensional (3D) micro/nanopolymer structures having high aspect ratios of up to 5 with a resolution of sub-100 nm. In addition, the effects of the irradiation dose and beam current on the physicochemical properties of the deposited polymers were investigated by recording the FT-IR spectra and Young's modulus. Interestingly, the overall shapes of the obtained structures were different from those prepared in our recent study using a focused ion beam (FIB) even if the samples were irradiated in a similar manner. This may be due to the different transmission between the two types of beams as discussed on the basis of the theoretical calculations of the quantum beam trajectories. Perceptions obtained in this study provide facile preparation procedures for the micro/nanostructures.

  2. Fluorescence and Raman spectra on surface of K9 glass by high fluence ultraviolet laser irradiation at 355 nm

    NASA Astrophysics Data System (ADS)

    Zhang, Zhen; Huang, Jin; Geng, Feng; Zhou, Xiaoyan; Feng, Shiquan; Ren, Dahua; Cheng, Xinlu; Jiang, Xiaodong; Wu, Weidong; Zheng, Wanguo; Tang, Yongjian

    2013-11-01

    In order to explore the damage mechanisms of K9 glass irradiated by high energy density ultraviolet laser, laser-induced fluorescence and Raman spectra were investigated. Compared the fluorescence spectra of damaged area, undamaged area and sub-damaged area, it can be conclude that the fluorescence spectrum of sub-damaged area is different from the structure of the other two areas. Especially, the main peak of the spectra at 415 nm reveals the unique characteristics of K9 glass. The structure at the sub-damaged area enhances intensity of the Raman scattering spectra. Three peaks of the spectra at about 500 nm and two characteristic peaks at about 550 nm exhibit the characterization of damaged area. A peak of the Raman scattering spectra at 350 nm which related to water can be observed. The relationship between intensity of Raman scattering and laser intensity at 355 nm is investigated by confocal Raman microscopy. At sub-damage area, signal of Raman scattering is rather high and decreased dramatically with respect to energy density. The major band at about 1470 cm-1 sharpened and moved to higher frequency with densification. These phenomena demonstrate that the structure of sub-damaged area has some characterization compared with the damaged area. The investigation of defect induced fluorescence and Raman spectra on surface of K9 glass is important to explore the damage mechanisms of optical materials irradiated by ultraviolet laser irradiation at 355 nm.

  3. A novel Ce(IO3)4 catalyst: Facile preparation and high activity in degradation of organic dyes without light irradiation at room temperature

    NASA Astrophysics Data System (ADS)

    Li, Jiayin; Ma, Xinping; Zhao, Caixian; Lan, Fujun; Chen, Feng; Liu, Xuan; Tang, Jianting

    2017-01-01

    Developing efficient catalysts capable of degrading organic dye free of light irradiation is highly interesting from the energy-saving point of view. In this work, we prepared a new Ce(IO3)4 catalyst by a facile precipitation method. The obtained Ce(IO3)4 sample showed remarkably superior performance to the reported CeGeO4 analog in degradation of rhodamine B (RhB), methyl orange (MO) or methylene blue (MB) dyes in the dark at room temperature. The ultraviolet-visible (UV-vis) absorption spectra of dye solution during degradation, the XPS results of Ce(IO3)4 and the control experiments confirmed that the dye degradation is a catalytic process. The reusability of it was also investigated in the degradation experiments.

  4. IR spectra of ion-irradiated ices containing SO2 and H2S

    NASA Astrophysics Data System (ADS)

    Moore, M. H.; Hudson, R. L.; Carlson, R. W.

    2002-09-01

    Spectra of Europa reveal a surface dominated by water-ice (1) along with hydrated materials (2,3) and minor amounts of SO2 (4,5), CO2(6), and H2O2 (7). The surface is under intense bombardment by the Jovian magnetospheric radiation (protons, electrons, sulfur and oxygen ions), which can alter the surface composition through radiolysis and ion implantation. In order understand the radiation induced changes in Europa-like ices, we have measured the mid-IR spectrum of proton irradiated H2O ice containing SO2 or H2S. Ices with H2O/SO2 or H2O/H2S ratios of 3 and 30 have been irradiated at 86 K, 110 K and 132 K. Several new products are identified, e.g. sulfate is formed in H2O + SO2 irradiated ices. The radiation half-life of SO2 and H2S in H2O is calculated. Applications of these results to Europa are included. This research is supported through NASA/ Planetary Geology and Geophysics (1) Calvin, W.M. et al. 1995, J. G R 100; (2) McCord, T.B. et al. 1998, Science 280; (3) Carlson, R.W. et al, 1999, Science 97; (4) Lane, A.L. et al. 1981, Nature 292; (5) Noll, K.S. et al. 1995 JGR 102; (6) Smythe, W.D. et al. 1998 LPSC; (7) Carlson, R.W. et al. 1999, Science 283

  5. Microstructure chemistry and mechanical properties of Ni-based superalloy Rene N4 under irradiation at room temperature

    SciTech Connect

    Sun, C.; Kirk, M.; Li, M.; Hattar, Khalid Mikhiel; Wang, Y.; Anderoglu, O.; Valdez, J.; Uberuaga, B. P.; Dickerson, R.; Maloy, S. A.

    2015-06-14

    Nickel superalloys with cubic L12 structured γ' (Ni3(Al, Ti)) precipitates exhibit high strength at high temperatures and excellent corrosion resistance when exposed to water. Unlike prior studies on irradiation damage of other Ni-based superalloys, our study on Rene N4 involves much larger γ' precipitates, ~450 nm in size, a size regime where the irradiation-induced disordering and dissolution kinetics and the corresponding mechanical property evolution are unknown. Under heavy ion irradiation at room temperature, the submicron-sized γ' precipitates were fully disordered at ~0.3 dpa and only later partially dissolved after 75 dpa irradiation. Nanoindentation experiments indicate that the mechanical properties of the alloy change significantly, with a dramatic decrease in hardness, with irradiation dose. Three contributions to the change in hardness were examined: defect clusters, disordering and dissolution. Moreover, the generation of defect clusters in the matrix and precipitates slightly increased the indentation hardness, while disordering of the submicron-sized γ' precipitates resulted in a dramatic decrease in the total hardness, which decreased further during the early stages of the intermixing between γ' precipitates and matrix (<18 dpa). As a result, controlling the long-range-ordering and chemical intermixing can be used to tailor the mechanical properties of Ni-based superalloys under irradiation.

  6. Microstructure chemistry and mechanical properties of Ni-based superalloy Rene N4 under irradiation at room temperature

    DOE PAGES

    Sun, C.; Kirk, M.; Li, M.; ...

    2015-06-14

    Nickel superalloys with cubic L12 structured γ' (Ni3(Al, Ti)) precipitates exhibit high strength at high temperatures and excellent corrosion resistance when exposed to water. Unlike prior studies on irradiation damage of other Ni-based superalloys, our study on Rene N4 involves much larger γ' precipitates, ~450 nm in size, a size regime where the irradiation-induced disordering and dissolution kinetics and the corresponding mechanical property evolution are unknown. Under heavy ion irradiation at room temperature, the submicron-sized γ' precipitates were fully disordered at ~0.3 dpa and only later partially dissolved after 75 dpa irradiation. Nanoindentation experiments indicate that the mechanical properties ofmore » the alloy change significantly, with a dramatic decrease in hardness, with irradiation dose. Three contributions to the change in hardness were examined: defect clusters, disordering and dissolution. Moreover, the generation of defect clusters in the matrix and precipitates slightly increased the indentation hardness, while disordering of the submicron-sized γ' precipitates resulted in a dramatic decrease in the total hardness, which decreased further during the early stages of the intermixing between γ' precipitates and matrix (<18 dpa). As a result, controlling the long-range-ordering and chemical intermixing can be used to tailor the mechanical properties of Ni-based superalloys under irradiation.« less

  7. Determination of the neutron fluence spectra in the neutron therapy room of KIRAMS.

    PubMed

    Kim, B H; Kim, J S; Kim, J L; Kim, Y S; Yang, T G; Lee, M Y

    2007-01-01

    High energy proton induced neutron fluence spectra were determined at the Korea Institute of Radiological and Medical Sciences (KIRAMS) using an extended Bonner Sphere (BS) set from the Korea Atomic Energy Research Institute (KAERI) in a series of measurements to quantify the neutron field. At the facility of the MC50 cyclotron of KIRAMS, two Be targets of different thicknesses, 1.0 and 10.5 mm, were bombarded by 35 and 45-MeV protons to produce six kinds of neutron fields, which were classified according to the measurement position and the use or no use of a beam collimator such as the gantry of the neutron therapy unit. In order to obtain a priori information to unfold the measured BS data the MCNPX code was used to calculate the neutron spectrum, and the influence of the surrounding materials for cooling the target assembly were also reviewed through this calculation. Some dosimetric quantities were determined by using the spectra determined in this measurement. Dose equivalent rates of these neutron fields ranged from 0.21 to 5.66 mSv h(-1)nA(-1) and the neutron yields for a thick Be target were 3.05 and 4.77% in the case of using a 35 and a 45-MeV proton, respectively.

  8. Measurements of X-ray doses and spectra produced by picosecond laser-irradiated solid targets.

    PubMed

    Yang, Bo; Qiu, Rui; Yu, Minghai; Jiao, Jinlong; Lu, Wei; Yan, Yonghong; Zhang, Bo; Zhang, Zhimeng; Zhou, Weimin; Li, Junli; Zhang, Hui

    2017-05-01

    Experiments have shown that high-intensity laser interaction with a solid target can generate significant X-ray doses. This study was conducted to determine the X-ray doses and spectra produced for picosecond laser-irradiated solid targets. The photon doses and X-ray spectra in the laser forward and side directions were measured using an XG III ps 300 TW laser system. For laser intensities of 7×10(18)-4×10(19)W/cm(2), the maximum photon dose was 16.8 mSv at 50cm with a laser energy of ~153J on a 1-mm Ta target. The photon dose in the forward direction increased more significantly with increasing laser intensity than that in the side direction. For photon energies >300keV, the X-ray spectrum can be fit with an effective temperature distribution of the exponential form, dN/dE = k× exp(-E/Tx). The X-ray temperature Tx increased with the laser intensity in the forward direction with values of 0.46-0.75MeV. Tx was less strongly correlated with the laser intensity in the side direction with values of 0.29-0.32MeV. The escaping electron spectrum was also measured. The measured electron temperature was correlated with the electron temperature predicted by the ponderomotive law. The observations in this experiment were also investigated numerically. A good agreement was observed between the experimental and simulation results.

  9. Spreading resistance and C-DLTS spectra of proton-irradiated mesa diodes made on thick epitaxial Si layers

    NASA Astrophysics Data System (ADS)

    Nossarzewska-Orłowska, E.; Kozłowski, R.; Brzozowski, A.

    1999-04-01

    High-resistivity, thick silicon epitaxial layers, deposited on Czochralski silicon (CZ Si) substrate were used as a material for test diodes. Resistivity profile as a function of depth and deep-level spectra were measured by spreading resistance method and deep-level transient spectroscopy (C-DLTS) on non-irradiated and proton irradiated mesa diodes. A deep level with activation energy E c-0.52 eV, attributed to V 2O defect, dominates in the non-irradiated diodes. After irradiation two levels, Ec-0.38 and Ec-0.45 eV, related to divacancies and the level Ec-0.17 eV corresponding to VO complex are distinguished.

  10. Effect of annealing on Raman spectra of monolayer graphene samples gradually disordered by ion irradiation

    NASA Astrophysics Data System (ADS)

    Zion, E.; Butenko, A.; Kaganovskii, Yu.; Richter, V.; Wolfson, L.; Sharoni, A.; Kogan, E.; Kaveh, M.; Shlimak, I.

    2017-03-01

    Raman scattering spectra (RS) of two series of monolayer graphene samples irradiated with various doses of C + and Xe + ions were measured after annealing in a high vacuum and in forming gas (95%Ar + 5%H2). It is shown that annealing below 500 °C leads to a significant decrease in both the D-line, associated with defects, and the 2D-line, associated with the intact lattice structure. This can be explained by annealing-induced enhanced doping. Further annealing in a vacuum up to 1000 °C leads to a significant increase in the 2D-line together with a continuous decrease in the D-line. This gives evidence for the partial removal of the defects and restoration of the damaged lattice. Annealing in forming gas is less effective in this sense. A blue shift of all lines is observed after annealing. It is shown that below 500 °C, unintentional doping is the main origin of the shift. At higher annealing temperatures, the blue shift is mainly due to lattice strain arising because of mismatch between the thermal expansion coefficients of graphene and the substrate. Inhomogeneous distribution of stress and doping across the samples lead to the correlated variation of the height and peak position of RS lines.

  11. Ultrafast dynamics and excited state spectra of open-chain carotenoids at room and low temperatures.

    PubMed

    Niedzwiedzki, Dariusz; Koscielecki, Jeremy F; Cong, Hong; Sullivan, James O; Gibson, George N; Birge, Robert R; Frank, Harry A

    2007-05-31

    Many of the spectroscopic features and photophysical properties of carotenoids are explained using a three-state model in which the strong visible absorption of the molecules is associated with an S0 (1(1)Ag-) --> S2 (1(1)Bu+) transition, and the lowest lying singlet state, S1 (2(1)Ag-), is a state into which absorption from the ground state is forbidden by symmetry. However, semiempirical and ab initio quantum calculations have suggested additional excited singlet states may lie either between or in the vicinity of S1 (2(1)Ag-) and S2 (1(1)Bu+), and some ultrafast spectroscopic studies have reported evidence for these states. One such state, denoted S*, has been implicated as an intermediate in the depopulation of S2 (1(1)Bu+) and as a pathway for the formation of carotenoid triplet states in light-harvesting complexes. In this work, we present the results of an ultrafast, time-resolved spectroscopic investigation of a series of open-chain carotenoids derived from photosynthetic bacteria and systematically increasing in their number of pi-electron carbon-carbon double bonds (n). The molecules are neurosporene (n = 9), spheroidene (n = 10), rhodopin glucoside (n = 11), rhodovibrin (n = 12), and spirilloxanthin (n = 13). The molecules were studied in acetone and CS2 solvents at room temperature. These experiments explore the effect of solvent polarity and polarizability on the spectroscopic and kinetic behavior of the molecules. The molecules were also studied in ether/isopentane/ethanol (EPA) glasses at 77 K, in which the spectral resolution is greatly enhanced. Analysis of the data using global fitting techniques has revealed the ultrafast dynamics of the excited states and spectral changes associated with their decay, including spectroscopic features not previously reported. The data are consistent with S* being identified with a twisted conformational structure, the yield of which is increased in molecules having longer pi-electron conjugations. In particular

  12. Reconstitution and Upgrade of the Thermal Neutron Irradiation Facility in the Basement Medical Room of the MIT Research Reactor

    SciTech Connect

    Harling, Otto, K.; Riley, Kent, J.; Binns, Peter J.

    2004-12-31

    The M-011 thermal neutron beam has been reconstituted and upgraded to provide a high intensity and high quality facility for preclinical and certain clinical studies. Intensities of thermal neutrons in the beam range from 5.0-8.5 x 109 n cm-2 s-1. Beam contamination is at a low level where it has no practical influence on beam performance. New computer controlled dose and beam monitoring systems have been implemented which assure precise dose delivery and redundant safety interlocks. An additional beam shutter and massive shielding in the back of the medical room have been added which significantly reduce room background and now permit staff entry without the necessity for lowering the reactor power. This system is needed for BNCT research by the MIT group as well as other US groups. This need became acute with the closure of the BMRR which previously had the only high quality thermal neutron irradiation facility for BNCT in the USA.

  13. NO gas sensing kinetics at room temperature under UV light irradiation of In2O3 nanostructures

    NASA Astrophysics Data System (ADS)

    Chinh, Nguyen Duc; Quang, Nguyen Duc; Lee, Hyundong; Thi Hien, Truong; Hieu, Nguyen Minh; Kim, Dahye; Kim, Chunjoong; Kim, Dojin

    2016-10-01

    In2O3 nanostructure sensors were fabricated by arc-discharging a source composed of a graphite tube containing indium. The NO gas sensing properties, as well as the morphology, structure, and electrical properties, were examined at room temperature under UV light illumination. In particular, the response and recovery kinetics of the sensor at room temperature under various UV light intensities were studied. The maximum response signal was observed at an intermediate UV light intensity, which could be corroborated by a nano-size effect based on the conduction model of a resistive chemical nano sensor. The mechanism for the enhanced adsorption/desorption kinetics for NO in an air environment under UV light irradiation is discussed in detail. Furthermore, the general requirements of the sensor, including the stability, repeatability, and selectivity, are discussed.

  14. NO gas sensing kinetics at room temperature under UV light irradiation of In2O3 nanostructures

    PubMed Central

    Chinh, Nguyen Duc; Quang, Nguyen Duc; Lee, Hyundong; Thi Hien, Truong; Hieu, Nguyen Minh; Kim, Dahye; Kim, Chunjoong; Kim, Dojin

    2016-01-01

    In2O3 nanostructure sensors were fabricated by arc-discharging a source composed of a graphite tube containing indium. The NO gas sensing properties, as well as the morphology, structure, and electrical properties, were examined at room temperature under UV light illumination. In particular, the response and recovery kinetics of the sensor at room temperature under various UV light intensities were studied. The maximum response signal was observed at an intermediate UV light intensity, which could be corroborated by a nano-size effect based on the conduction model of a resistive chemical nano sensor. The mechanism for the enhanced adsorption/desorption kinetics for NO in an air environment under UV light irradiation is discussed in detail. Furthermore, the general requirements of the sensor, including the stability, repeatability, and selectivity, are discussed. PMID:27713526

  15. Influence of ageing on Raman spectra and the conductivity of monolayer graphene samples irradiated by heavy and light ions

    NASA Astrophysics Data System (ADS)

    Butenko, A.; Zion, E.; Kaganovskii, Yu.; Wolfson, L.; Richter, V.; Sharoni, A.; Kogan, E.; Kaveh, M.; Shlimak, I.

    2016-07-01

    The influence of long-term ageing (about one year) on the Raman scattering (RS) spectra and the temperature dependence of conductivity has been studied in two series of monolayer graphene samples irradiated by different doses of C+ and Xe+ ions. It is shown that the main result of ageing consists of changes in the intensity and position of D- and G- and 2D-lines in RS spectra and in an increase of the conductivity. The observed effects are explained in terms of an increase of the radius of the "activated" area around structural defects.

  16. Influence of ageing on Raman spectra and the conductivity of monolayer graphene samples irradiated by heavy and light ions

    SciTech Connect

    Butenko, A.; Zion, E.; Richter, V.; Sharoni, A.; Kaganovskii, Yu.; Wolfson, L.; Kogan, E.; Kaveh, M.; Shlimak, I.

    2016-07-28

    The influence of long-term ageing (about one year) on the Raman scattering (RS) spectra and the temperature dependence of conductivity has been studied in two series of monolayer graphene samples irradiated by different doses of C{sup +} and Xe{sup +} ions. It is shown that the main result of ageing consists of changes in the intensity and position of D- and G- and 2D-lines in RS spectra and in an increase of the conductivity. The observed effects are explained in terms of an increase of the radius of the “activated” area around structural defects.

  17. Exciton polariton spectra and limiting factors for the room-temperature photoluminescence efficiency in ZnO

    NASA Astrophysics Data System (ADS)

    Chichibu, S. F.; Uedono, A.; Tsukazaki, A.; Onuma, T.; Zamfirescu, M.; Ohtomo, A.; Kavokin, A.; Cantwell, G.; Litton, C. W.; Sota, T.; Kawasaki, M.

    2005-04-01

    Static and dynamic responses of excitons in state-of-the-art bulk and epitaxial ZnO are reviewed to support the possible realization of polariton lasers, which are coherent and monochromatic light sources due to Bose condensation of exciton-polaritons in semiconductor microcavities (MCs). To grasp the current problems and to pave the way for obtaining ZnO epilayers of improved quality, the following four principal subjects are treated: (i) polarized optical reflectance (OR), photoreflectance (PR) and photoluminescence (PL) spectra of the bulk and epitaxial ZnO were recorded at 8 K. Energies of PR resonances corresponded to those of upper and lower exciton-polariton branches, where A-, B- and C-excitons couple simultaneously to an electromagnetic wave. PL peaks due to the corresponding polariton branches were observed. Longitudinal-transverse splittings (ωLT) of the corresponding excitons were 1.5, 11.1 and 13.1 meV, respectively. The latter two values are more than two orders of magnitude greater than that of GaAs being 0.08 meV. (ii) Using these values and material parameters, corresponding vacuum-field Rabi splitting of exciton-polaritons coupled to a model MC mode was calculated to be 191 meV, which is the highest value ever reported for semiconductor MCs and satisfies the requirements to observe the strong exciton-light coupling regime necessary for polariton lasing above room temperature. (iii) Polarized OR and PR spectra of an out-plane nonpolar (1\\,1\\,\\bar{2}\\,0) ZnO epilayer grown by laser-assisted molecular beam epitaxy (L-MBE) were measured, since ZnO quantum wells (QWs) grown in nonpolar orientations are expected to show higher emission efficiencies due to the elimination of spontaneous and piezoelectric polarization fields normal to the QW plane. They exhibited in-plane anisotropic exciton resonances according to the polarization selection rules for anisotropically-strained wurzite material. (iv) Impacts of point defects on the nonradiative

  18. [Low level laser irradiation in the visible spectra induces HeLa cells proliferation].

    PubMed

    Yang, Hong-qin; Wang, Yu-hua; Chen, Jiang-xu; Zheng, Li-qin; Xie, Shu-sen

    2012-04-01

    The aim of this in vitro study was to evaluate the effects of low level laser irradiation on the proliferation of HeLa cells using 405 nm diode laser, 514 nm argon laser, 633 nm He-Ne laser, or 785 nm diode laser, The cells were seeded on 96-well microplates for 24 h in 5% fetal bovine serum containing medium, then irradiated with the laser at dose of 100 and 1 000 J x m(-2), respectively. At the time point of 24, 48, 72 h after irradiation, cell viability was assessed by MTT assay. The results show that 405, 633 and 785 nm laser irradiation induces wavelength-dependent and time-dependent proliferation. 633 nm laser irradiation results in a stimulatory proliferation effect that is most significant, whereas 514 nm laser irradiation produces little increase in cell proliferation. Low level laser irradiation increases cell proliferation in a dose-dependent manner. 1 000 J x m(-2) laser irradiation is more effective in increasing cell proliferation than 100 J x m(-2) laser irradiation using 405 nm diode laser, 633 nm He-Ne laser, or 785 nm diode laser, but not as effective as using 514 nm argon laser.

  19. gamma-Irradiation effects on the thermal decomposition behaviour and IR absorption spectra of piperacillin

    NASA Astrophysics Data System (ADS)

    Mahfouz, R. M.; Gaffar, M. A.; Abu El-Fadl, A.; Hamad, Ar. G. K.

    2003-11-01

    The thermal decomposition behaviour of unirradiated and pre-gamma-irradiated piperacillin (pipril) as a semi-synthetic penicillin antibiotic has been studied in the temperature range of (273-1072 K). The decomposition was found to proceed through three major steps both for unirradiated and gamma-irradiated samples. Neither appearance nor disappearance of new bands in the IR spectrum of piperacillin was recorded as a result of gamma-irradiation but only a decrease in the intensity of most bands was observed. A degradation mechanism was suggested to explain the bond rupture and the decrease in the intensities of IR bands of gamma-irradiated piperacillin.

  20. Electron spectra of xenon clusters irradiated with a laser-driven plasma soft-x-ray laser pulse

    SciTech Connect

    Namba, S.; Takiyama, K.; Hasegawa, N.; Kishimoto, M.; Nishikino, M.; Kawachi, T.

    2011-11-15

    Xenon clusters were irradiated with plasma soft-x-ray laser pulses (having a wavelength of 13.9 nm, time duration of 7 ps, and intensities of up to 10 GW/cm{sup 2}). The laser photon energy was high enough to photoionize 4d core electrons. The cross section is large due to a giant resonance. The interaction was investigated by measuring the electron energy spectra. The photoelectron spectra for small clusters indicate that the spectral width due to the 4d hole significantly broadens with increasing cluster size. For larger clusters, the electron energy spectra evolve into a Maxwell-Boltzmann distribution, as a strongly coupled cluster nanoplasma is generated.

  1. Inverse Analysis of Irradiated NuclearMaterial Gamma Spectra via Nonlinear Optimization

    NASA Astrophysics Data System (ADS)

    Dean, Garrett James

    Nuclear forensics is the collection of technical methods used to identify the provenance of nuclear material interdicted outside of regulatory control. Techniques employed in nuclear forensics include optical microscopy, gas chromatography, mass spectrometry, and alpha, beta, and gamma spectrometry. This dissertation focuses on the application of inverse analysis to gamma spectroscopy to estimate the history of pulse irradiated nuclear material. Previous work in this area has (1) utilized destructive analysis techniques to supplement the nondestructive gamma measurements, and (2) been applied to samples composed of spent nuclear fuel with long irradiation and cooling times. Previous analyses have employed local nonlinear solvers, simple empirical models of gamma spectral features, and simple detector models of gamma spectral features. The algorithm described in this dissertation uses a forward model of the irradiation and measurement process within a global nonlinear optimizer to estimate the unknown irradiation history of pulse irradiated nuclear material. The forward model includes a detector response function for photopeaks only. The algorithm uses a novel hybrid global and local search algorithm to quickly estimate the irradiation parameters, including neutron fluence, cooling time and original composition. Sequential, time correlated series of measurements are used to reduce the uncertainty in the estimated irradiation parameters. This algorithm allows for in situ measurements of interdicted irradiated material. The increase in analysis speed comes with a decrease in information that can be determined, but the sample fluence, cooling time, and composition can be determined within minutes of a measurement. Furthermore, pulse irradiated nuclear material has a characteristic feature that irradiation time and flux cannot be independently estimated. The algorithm has been tested against pulse irradiated samples of pure special nuclear material with cooling times of

  2. Shielding design of a treatment room for an accelerator-based epithermal neutron irradiation facility for BNCT.

    PubMed

    Evans, J F; Blue, T E

    1996-11-01

    Protecting the facility personnel and the general public from radiation exposure is a primary safety concern of an accelerator-based epithermal neutron irradiation facility. This work makes an attempt at answering the questions "How much?" and "What kind?" of shielding will meet the occupational limits of such a facility. Shielding effectiveness is compared for ordinary and barytes concretes in combination with and without borated polyethylene. A calculational model was developed of a treatment room , patient "scatterer," and the epithermal neutron beam. The Monte Carlo code, MCNP, was used to compute the total effective dose equivalent rates at specific points of interest outside of the treatment room. A conservative occupational effective dose rate limit of 0.01 mSv h-1 was the guideline for this study. Conservative Monte Carlo calculations show that constructing the treatment room walls with 1.5 m of ordinary concrete, 1.2 m of barytes concrete, 1.0 m of ordinary concrete preceded by 10 cm of 5% boron-polyethylene, or 0.8 m of barytes concrete preceded by 10 cm of 5% boron-polyethylene will adequately protect facility personnel.

  3. Shielding design of a treatment room for an accelerator-based epithermal neutron irradiation facility for BNCT

    SciTech Connect

    Evans, J.F.; Blue, T.E.

    1996-11-01

    Protecting the facility personnel and the general public from radiation exposure is a primary safety concern of an accelerator-based epithermal neutron irradiation facility. This work makes an attempt at answering the questions {open_quotes}How much?{close_quotes} and {open_quotes}What kind?{close_quotes} of shielding will meet the occupational limits of such a facility. Shielding effectiveness is compared for ordinary and barytes concretes in combination with and without borated polyethylene. A calculational model was developed of a treatment room, patient {open_quotes}scatterer,{close_quotes} and the epithermal neutron beam. The Monte Carlo code, MCNP, was used to compute the total effective dose equivalent rates at specific points of interest outside of the treatment room. A conservative occupational effective dose rate limit of 0.01 mSv h{sup {minus}1} was the guideline for this study. Conservative Monte Carlo calculations show that constructing the treatment room walls with 1.5 m of ordinary concrete, 1.2 m of barytes concrete, 1.0 m of ordinary concrete preceded by 10 cm of 5% boron-polyethylene, or 0.8 m of barytes concrete preceded by 10 cm of 5% boron-polyethylene will adequately protect facility personnel. 20 refs., 8 figs., 2 tabs.

  4. Gamma-irradiated dry fruits. An example of a wide variety of long-time dependent EPR spectra

    NASA Astrophysics Data System (ADS)

    Yordanov, Nicola D.; Pachova, Zdravka

    2006-03-01

    EPR spectra of dry, sugar containing fruits—raisins, sultanas, figs, dates, peaches, blue plums and chokeberry recorded before and after irradiation with gamma-rays, are reported. It is shown that weak singlet EPR line with 2.0031 ± 0.0005 can be recorded before irradiation of seeds, stones or skin of chokeberry, figs and raisins as well as flesh of blue plum, raisins and peaches. EPR signals of various shape are distinguished after irradiation in different parts of the fruits, as well as in randomly cut pieces of them: Seeds of raisins, chokeberry and figs give a singlet line. Stones from blue plums and peaches exhibit typical "cellulose-like" EPR signal consisting of an intense singlet line with g = 2.0033 ± 0.0005 and 2 week satellite lines situated ca. 30 G left and right to it. Stones of dates are the only sample in which "sugar-like" spectrum is recorded. Skin of raisins and figs exhibits "sugar-like" EPR spectrum whereas that of dates and chokeberry—a singlet line. Under the same experimental conditions skin of sultanas, peaches and blue plums are EPR silent. Flesh of raisins, sultanas, figs, dates and peaches exhibits "sugar-like" EPR spectrum, flesh of blue plums gives a singlet EPR line and that of chokeberry is EPR silent. As a result, randomly cut pieces of dry fruits suitable for EPR studies, containing various constituents, exhibit different in shape and intensity EPR spectra. Kinetic studies followed for 1 year on the time stability of all reported EPR signals indicate that intensity ratio between the simultaneously appearing EPR signals in particular fruit varies from 1:20 immediately after irradiation to 1:0.5 at the end of the period. These observations open a new possibility for identification of irradiated fruits - using the magnitude of the intensity ratio to find the approximate date of radiation processing in the first ca. 30-100 days.

  5. Far infrared spectra of amorphous and crystalline water ice and changes in these phases as the result of proton irradiation

    NASA Technical Reports Server (NTRS)

    Hudson, Reggie L.; Moore, Marla H.

    1992-01-01

    Far infrared spectra from 20 microns (500 cm(sup -1)) to 100 microns (100 cm(sup -1)) of water ice were measured. Amorphous ice deposited at 13 K has one absorption band at 45 microns (220 cm(sup -1)). Amorphous ice evolves into a crystalline form with absorptions at 44 microns (229 cm(sup -1)) and 62 microns (162 cm(sup -1)) as the temperature is increased to 155 K. Spectra documenting this phase change are presented as well as spectra of crystalline ice at temperatures between 13 K and 155 K. Far infrared spectra of amorphous and crystalline water ice before and after proton irradiation are also presented. Changes in these two forms are discussed in relation to ices in comets, grains, and planetary satellites in various radiation environments. Observations of non-terrestrial clathrate hydrates are still lacking despite the fact that clathrates first were suggested to exist in cometary and interstellar ices over forty years ago. Spectroscopy, the most direct method of astronomical detection, has been hampered by the similarity of clathrate hydrate spectra to those of unenclathrated guest molecules and solid H2O. A methanol (CH3OH) clathrate hydrate, using a recently published procedure, was prepared and its far-IR spectrum investigated. The spectrum is quite differenct from that of either unenclathrated CH3OH or solid H2O and so should be of value in astronomical searches for this clathrate.

  6. Simultaneous measurement of irradiance and reflected radiance in field determination of spectra reflectance

    SciTech Connect

    Duggin, M.J.

    1981-11-15

    The effects of irradiation fluctuations on measured reflectance values have been determined to evaluate whether data collected in sunny or partly cloudy conditions are sufficiently in agreement that they may be used for remote or satellite sensing data collection (e.g. op discuss quantification). Simultaneous measurements were obtained of irradiance and reflected radiance using two Exotech GTR 100 mode Landsat ground-truth radiometers. (AIP)

  7. Io's surface composition based on reflectance spectra of sulfur/salt mixtures and proton-irradiation experiments

    NASA Technical Reports Server (NTRS)

    Nash, D. B.; Fanale, F. P.

    1977-01-01

    Available full-disk reflectance spectra of Io in the range 0.3 to 2.5 microns have been used to determine a surface compositional model for Io that is consistent with Io's other known chemical and physical properties. Results indicate that the surface of Io contains abundant dehydrated salts of high Na, Mg, and Fe(3+) content such as bloedite and ferrous iron sulfate. Experiments were performed studying the irradiation damage effects from low-energy proton bombardment, since Io is immersed in Jupiter's magnetosphere.

  8. On the assignment of the room temperature ESR spectrum of gamma irradiated poly(ethylene glycol dimethacrylate)

    NASA Astrophysics Data System (ADS)

    Brown, L.; Carswell-Pomerantz, T. G.; Hill, D. J. T.; Pomery, P. J.

    1996-11-01

    The ESR spectrum of poly(ethylene glycol dimethacrylate) observed at room temperature following gamma radiolysis is characterized by an eleven-line spectrum. Some authors have assigned the outer lines in this spectrum to the presence of formyl radicals which have been stabilized at the prevailing temperature by the cross linked network. In this paper we re-evaluate this assignment and show that a more likely explanation of the spectrum is that there is that there are three conformations of the propagating radicals present, corresponding to the three possible rotational conformers which can be formed about the β-methylene group. It is suggested that the third conformer, which is not found for poly(methyl methacrylate) and most other methacrylate polymers, is stabilized by the cross linked structure of this polymer. A similar explanation is suggested as an explanation for the eleven-line ESR spectrum observed for poly(methacrylic acid) following irradiation at room temperature, where the stabilization is suggested to occur due to hydrogen bond through the carboxyl groups.

  9. Transient absorption and luminescence spectra of K9 glass at sub-damage site by ultraviolet laser irradiation

    NASA Astrophysics Data System (ADS)

    Zhang, Z.; Huang, J.; Geng, F.; Zhou, X. Y.; Feng, S. Q.; Cheng, X. L.; Jiang, X. D.; Wu, W. D.; Zheng, W. G.; Tang, Y. J.

    2014-01-01

    Transient absorption and luminescence spectra at sub-damage site of K9 glass by laser irradiation at 355 nm are presented. The dependence of transient absorption on laser energy and number of pulses was investigated. As the energy density increases to 2.54 and 3.18 J/cm2, the transient absorption intensity reaches to about 0.20 range from 400 to 480 nm. With the increase of number of pulses the process of residual absorption appears, which can be used to explain the fatigue effect of K9 glass. The defects in K9 glass were investigated by fluorescence and Raman spectra. The fluorescence band centered at about 410 nm is attributed to oxygen deficiency centers. The mechanism of two-photon ionization plays a critical role at sub-damage site. Compared to the Raman spectra of pristine site, intensity of Raman spectra is very high at a lower energy density, while it decreased at a higher energy density.

  10. Comparison of Pre-and Post-Irradiation Low-Frequency Noise Spectra of Midwave Infrared nBn Detectors With Superlattice Absorbers

    NASA Astrophysics Data System (ADS)

    Garduño, Eli A.; Cowan, Vincent M.; Jenkins, Geoffrey D.; Morath, Christian P.; Steenbergen, Elizabeth H.

    2017-04-01

    Noise spectra of type-II strained layer superlattice midwave infrared photodetectors were compared preand postirradiation by a proton fluence of 7.5 × 1011 cm-2 [total ionizing dose equivalent of 100 krad (Si)] and related to the shot noise limit at biases ranging from +200 to -800 mV and temperatures of 130 and 160 K. Pre-irradiation dark current at 130 K was 7.5X Rule '07 and increased to 59X Rule '07 after irradiation. The pre-irradiation noise spectra were within one order of magnitude of the shot noise prediction, while post-irradiation noise spectra were close to two orders higher, indicating the introduction of nonshot-like noise sources.

  11. Implementation and workflow for PET monitoring of therapeutic ion irradiation: a comparison of in-beam, in-room, and off-line techniques

    NASA Astrophysics Data System (ADS)

    Shakirin, Georgy; Braess, Henning; Fiedler, Fine; Kunath, Daniela; Laube, Kristin; Parodi, Katia; Priegnitz, Marlen; Enghardt, Wolfgang

    2011-03-01

    An independent assessment of the dose delivery in ion therapy can be performed using positron emission tomography (PET). For that a distribution of positron emitters which appear as the result of interaction between ions of the therapeutic beam and the irradiated tissue is measured during or after the irradiation. Three concepts for PET monitoring implemented in various therapy facilities are considered in this paper. The in-beam PET concept relies on the PET measurement performed simultaneously to the irradiation by means of a PET scanner which is completely integrated into the irradiation site. The in-room PET concept allows measurement immediately after irradiation by a standalone PET scanner which is installed very close to the irradiation site. In the off-line PET scenario the measurement is performed by means of a standalone PET/CT scanner 10-30 min after the irradiation. These three concepts were evaluated according to image quality criteria, integration costs, and their influence onto the workflow of radiotherapy. In-beam PET showed the best performance. However, the integration costs were estimated as very high for this modality. Moreover, the performance of in-beam PET depends heavily on type and duty cycle of the accelerator. The in-room PET is proposed for planned therapy facilities as a good compromise between the quality of measured data and integration efforts. For facilities which are close to the nuclear medicine departments off-line PET can be suggested under several circumstances.

  12. Implementation and workflow for PET monitoring of therapeutic ion irradiation: a comparison of in-beam, in-room, and off-line techniques.

    PubMed

    Shakirin, Georgy; Braess, Henning; Fiedler, Fine; Kunath, Daniela; Laube, Kristin; Parodi, Katia; Priegnitz, Marlen; Enghardt, Wolfgang

    2011-03-07

    An independent assessment of the dose delivery in ion therapy can be performed using positron emission tomography (PET). For that a distribution of positron emitters which appear as the result of interaction between ions of the therapeutic beam and the irradiated tissue is measured during or after the irradiation. Three concepts for PET monitoring implemented in various therapy facilities are considered in this paper. The in-beam PET concept relies on the PET measurement performed simultaneously to the irradiation by means of a PET scanner which is completely integrated into the irradiation site. The in-room PET concept allows measurement immediately after irradiation by a standalone PET scanner which is installed very close to the irradiation site. In the off-line PET scenario the measurement is performed by means of a standalone PET/CT scanner 10-30 min after the irradiation. These three concepts were evaluated according to image quality criteria, integration costs, and their influence onto the workflow of radiotherapy. In-beam PET showed the best performance. However, the integration costs were estimated as very high for this modality. Moreover, the performance of in-beam PET depends heavily on type and duty cycle of the accelerator. The in-room PET is proposed for planned therapy facilities as a good compromise between the quality of measured data and integration efforts. For facilities which are close to the nuclear medicine departments off-line PET can be suggested under several circumstances.

  13. Effect of combination of chitosan coating and irradiation on physicochemical and functional properties of chicken egg during room-temperature storage

    NASA Astrophysics Data System (ADS)

    Liu, Xian De; Jang, Aera; Kim, Dong Hun; Lee, Bong Duk; Lee, Mooha; Jo, Cheorun

    2009-07-01

    The effect of combination of chitosan coating and irradiation on quality and storage stability of shell egg was investigated. Salmonella typhimurium inoculated on eggshell was not detected by irradiation of 2.0 kGy at day 0 and/or chitosan coating (1%, pH 5.0) after 3 days of storage. One-day-old fresh chicken egg was chitosan coated and irradiated at 0, 0.5, 1.0, 1.5 and 2.0 kGy by gamma ray. The egg samples were stored at room temperature for 14 days and the effects of the combination treatment on internal physicochemical and functional properties were investigated. The Haugh unit of egg was decreased by irradiation even at 0.5 kGy. Irradiation increased the lipid oxidation in egg yolk at 2 kGy but the egg with chitosan coating reduced the level of lipid oxidation. Irradiation increased the foaming ability of egg white and decreased viscosity of egg yolk and white. Results suggested that combination of irradiation and chitosan coating can improve safety of shell egg but irradiation treatment may reduce the egg quality for direct consumption. However, an improved functional property for further processing and efficient separation of egg white and yolk can be expected for egg processing industry using irradiation.

  14. Reflectance and transmittance spectra (2.2 2.4 μm) of ion irradiated frozen methanol

    NASA Astrophysics Data System (ADS)

    Brunetto, R.; Baratta, G. A.; Domingo, M.; Strazzulla, G.

    2005-05-01

    We present near-IR (2.2-2.4 μm) reflectance and transmittance spectra of frozen (16 and 77 K) methanol (CH 3OH) and water-methanol (1:1) mixtures before and after irradiation with 30 keV He + and 200 keV H + ions. Spectra of other simple hydrocarbons (CH 4, C 2H 2, C 2H 4, C 2H 6) and CO have also been obtained both to help in the identification of the new molecules formed after ion irradiation of methanol-rich ices, and to get insight into the question of the presence of simple frozen hydrocarbons on the surface of some objects in the outer Solar System. The results confirm what obtained by studies performed in different spectral ranges, namely the ion-induced formation of CO and CH 4, and, for the first time, evidence a strong decrease of the intensity of the methanol band at about 2.34 μm in comparison with that at 2.27 μm. The results are discussed in view of their relevance for icy objects in the Solar System (namely comets, Centaurs, and Kuiper belt objects) where CH 3OH has been observed or suggested to be present.

  15. Heavy ion irradiation-induced microstructural evolution in pyrochlore Lu{sub 2}Ti{sub 2}O{sub 7} at room temperature and 723 K

    SciTech Connect

    Xie, Q.R.; Zhang, J. Dong, X.N.; Guo, Q.X.; Li, N.

    2015-11-15

    Polycrystalline pyrochlore Lu{sub 2}Ti{sub 2}O{sub 7} pellets were irradiated with 600 keV Kr{sup 3+} at room temperature and 723 K to a fluence of 4×10{sup 15} ions/cm{sup 2}, corresponding to an average ballistic damage dose of 10 displacements per atom in the peak damage region. Irradiation-induced microstructural evolution was examined by grazing incidence X-ray diffraction, and cross-sectional transmission electron microscopy. Incomplete amorphization was observed in the sample irradiated at room temperature due to the formation of nano-crystal which has the identical structure of pyrochlore, and the formation of nano-crystal is attributed to the mechanism of epitaxial recrystallization. However, an ordered pyrochlore phase to a swelling disordered fluorite phase transformation is occurred for the Lu{sub 2}Ti{sub 2}O{sub 7} sample irradiated at 723 K, which is due to the disordering of metal cations and anion vacancies. - Graphical Abstract: Polycrystalline pyrochlore Lu{sub 2}Ti{sub 2}O{sub 7} pellets were irradiated with 600 keV Kr{sup 3+} to a fluence of 4×10{sup 15} ions/cm{sup 2} at room temperature and 723 K, Incomplete amorphization was observed in the sample irradiated at room temperature due to the formation of nano-crystal. However, an ordered pyrochlore phase to a swelling disordered fluorite phase transformation is occurred for the Lu{sub 2}Ti{sub 2}O{sub 7} sample irradiated at 723 K, which is due to the disordering of metal cations and anion vacancies. - Highlights: Pyrochlore Lu{sub 2}Ti{sub 2}O{sub 7} pellets were irradiated by heavy ions at RT and 723 K. At RT irradiation, ~75% of amorphization was achieved. The nano-crystals were formed in the damage layer at RT irradiation. The formed nano-crystals enhanced the radiation tolerance of Lu{sub 2}Ti{sub 2}O{sub 7}. A pyrochlore to fluorite phase transformation was observed at 723 K irradiation.

  16. Effect of irradiance spectra on the photoinduced toxicity of three polycyclic aromatic hydrocarbons

    SciTech Connect

    Diamond, S.A.; Mount, D.R.; Burkhard, L.P.; Ankley, G.T.; Makynen, E.A.; Leonard, E.N.

    2000-05-01

    Photoinduced toxicity of polycyclic aromatic hydrocarbons (PAHs) is dependent on the concentration of compounds present and the dose of light received. Of the light present, only those wavelengths absorbed by the compound have the potential to initiate the photochemical events underlying phototoxicity. This suggests that variation in light spectra present in natural waters, arising from variation in dissolved organic carbon composition, is an important determinant of phototoxicity risk in specific, PAH-contaminated waterbodies. To quantify the effect of environmentally realistic variation in light spectra on toxicity, brine shrimp (Artemia salina) assays were conducted under various light spectra and with three PAHs (pyrene, fluoranthene, and anthracene) of known phototoxicity potential. In these spectral assays, the total ultraviolet light present was equivalent; only the spectral characteristics varied. Based on the absorbance spectra of these PAHs, it was predicted that toxicity, quantified using immobilization as the endpoint, would vary significantly among light spectra in pyrene assays, but not in anthracene assays, and that variation in toxicity in fluoranthene assays would be intermediate. The results supported these assumptions. In the pyrene exposures, the glass filter time to 50% population immobilization (IT50) (39.5 min) was 117% longer than the KCr filter IT50 (18.2 min). In the fluoranthene exposures, the glass filter IT50 (49.5 min) was 27% longer than the KCr filter IT50 (39.1 min). In the anthracene exposures, the glass filter IT50 (62.2 min) was not statistically different from the KCr filter IT50 (63.8 min). Comparison of these results with the results of assays conducted under neutral-density filters (that change intensity but not spectral distribution) demonstrate that multiplying spectral intensity by wavelength-specific absorbance accurately predicts relative photoinduced toxicity among the experimental treatments. These results indicate

  17. Study of neutron spectra in a water bath from a Pb target irradiated by 250 MeV protons

    NASA Astrophysics Data System (ADS)

    Li, Yan-Yan; Zhang, Xue-Ying; Ju, Yong-Qin; Ma, Fei; Zhang, Hong-Bin; Chen, Liang; Ge, Hong-Lin; Wan, Bo; Luo, Peng; Zhou, Bin; Zhang, Yan-Bin; Li, Jian-Yang; Xu, Jun-Kui; Wang, Song-Lin; Yang, Yong-Wei; Yang, Lei

    2015-04-01

    Spallation neutrons were produced by the irradiation of Pb with 250 MeV protons. The Pb target was surrounded by water which was used to slow down the emitted neutrons. The moderated neutrons in the water bath were measured by using the resonance detectors of Au, Mn and In with a cadmium (Cd) cover. According to the measured activities of the foils, the neutron flux at different resonance energies were deduced and the epithermal neutron spectra were proposed. Corresponding results calculated with the Monte Carlo code MCNPX were compared with the experimental data to check the validity of the code. The comparison showed that the simulation could give a good prediction for the neutron spectra above 50 eV, while the finite thickness of the foils greatly effected the experimental data in low energy. It was also found that the resonance detectors themselves had great impact on the simulated energy spectra. Supported by National Natural Science Foundation and Strategic Priority Research Program of the Chinese Academy of Sciences (11305229, 11105186, 91226107, 91026009, XDA03030300)

  18. Characterization of the fluorescence spectra produced by excimer laser irradiation of the cornea

    SciTech Connect

    Tuft, S.; al-Dhahir, R.; Dyer, P.; Zhu, Z.H. )

    1990-08-01

    The epithelium and stroma of bovine and human corneas were exposed to both ablative and subablative levels of 193-nm excimer laser radiation and the spectra of the induced fluorescence recorded. Two broad peaks in the emission spectra were observed, at 310 nm and 460 nm, with a difference in the relative height of these peaks between epithelium and stroma. The lower cut-off for fluorescence (260 nm) was similar for both tissues. Time-resolved measurements showed that fluorescence occurs on the nanosecond time scale, and an estimate gives the quantum yield for photons emitted in the 260-350-nm range as approximately 1 X 10(-5). The significance of these results in the evaluation of the safety of surgery with an argon fluoride excimer laser is discussed.

  19. Production of proton beams with narrow-band energy spectra from laser-irradiated ultrathin foils

    SciTech Connect

    Robinson, A. P. L; Gibbon, P.

    2007-01-15

    Three-dimensional gridless particle simulations of proton acceleration via irradiation of a very thin foil by a short-pulse, high-intensity laser have been performed to evaluate recently proposed microstructured target configurations. It is found that a pure proton microdot target does not by itself result in a quasimonoenergetic proton beam. Such a beam can only be produced with a very lightly doped target, in qualitative agreement with one-dimensional theory. The simulations suggest that beam quality in current experiments could be dramatically improved by choosing microdot compositions with a 5-10 times lower proton fraction.

  20. Production of proton beams with narrow-band energy spectra from laser-irradiated ultrathin foils.

    PubMed

    Robinson, A P L; Gibbon, P

    2007-01-01

    Three-dimensional gridless particle simulations of proton acceleration via irradiation of a very thin foil by a short-pulse, high-intensity laser have been performed to evaluate recently proposed microstructured target configurations. It is found that a pure proton microdot target does not by itself result in a quasimonoenergetic proton beam. Such a beam can only be produced with a very lightly doped target, in qualitative agreement with one-dimensional theory. The simulations suggest that beam quality in current experiments could be dramatically improved by choosing microdot compositions with a 5-10 times lower proton fraction.

  1. Impact of Room Location on UV-C Irradiance and UV-C Dosage and Antimicrobial Effect Delivered by a Mobile UV-C Light Device.

    PubMed

    Boyce, John M; Farrel, Patricia A; Towle, Dana; Fekieta, Renee; Aniskiewicz, Michael

    2016-06-01

    OBJECTIVE To evaluate ultraviolet C (UV-C) irradiance, UV-C dosage, and antimicrobial effect achieved by a mobile continuous UV-C device. DESIGN Prospective observational study. METHODS We used 6 UV light sensors to determine UV-C irradiance (W/cm2) and UV-C dosage (µWsec/cm2) at various distances from and orientations relative to the UV-C device during 5-minute and 15-minute cycles in an ICU room and a surgical ward room. In both rooms, stainless-steel disks inoculated with methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), and Clostridium difficile spores were placed next to sensors, and UV-C dosages and log10 reductions of target organisms achieved during 5-minute and 15-minute cycles were determined. Mean irradiance and dosage readings were compared using ANOVA. RESULTS Mean UV-C irradiance was nearly 1.0E-03 W/cm2 in direct sight at a distance of 1.3 m (4 ft) from the device but was 1.12E-05 W/cm2 on a horizontal surface in a shaded area 3.3 m (10 ft) from the device (P4 to 1-3 for MRSA, >4 to 1-2 for VRE and >4 to 0 log10 for C. difficile spores, depending on the distance from, and orientation relative to, the device with 5-minute and 15-minute cycles. CONCLUSION UV-C irradiance, dosage, and antimicrobial effect received from a mobile UV-C device varied substantially based on location in a room relative to the UV-C device. Infect Control Hosp Epidemiol 2016;37:667-672.

  2. Characterization of neutron flux spectra in the irradiation sites of a 37 GBq 241Am-Be isotopic source

    NASA Astrophysics Data System (ADS)

    Yücel, Haluk; Budak, Mustafa Guray; Karadag, Mustafa; Yüksel, Alptuğ Özer

    2014-11-01

    For the applicability of instrumental neutron activation analysis (NAA) technique, an irradiation unit with a 37 GBq 241Am-Be neutron source was installed at Institute of Nuclear Sciences of Ankara University. Design and configuration properties of the irradiation unit are described. It has two different sample irradiation positions, one is called site #1 having a pneumatic sample transfer system and the other is site #2 having a location for manual use. In order to characterize neutron flux spectra in the irradiation sites, the measurement results were obtained for thermal (Фth) and epithermal neutron fluxes (Фepi), thermal to epithermal flux ratio (f) and epithermal spectrum shaping factors (α) by employing cadmium ratios of gold (Au) and molybdenum (Mo) monitors. The activities produced in these foils were measured by using a p-type, 44.8% relative efficiency HPGe well detector. For the measured γ-rays, self-absorption and true coincidence summing effects were taken into account. Additionally, thermal neutron self-shielding and resonance neutron self-shielding effects were taken into account in the measured results. For characterization of site #1, the required parameters were found to be Фth = (2.11 ± 0.05) × 103 n cm-2 s-1, Фepi = (3.32 ± 0.17) × 101 n cm-2 s-1, f = 63.6 ± 1.5, α = 0.045 ± 0.009, respectively. Similarly, those parameters were measured in site #2 as Фth = (1.49 ± 0.04) × 103 n cm-2 s-1, Фepi = (2.93 ± 0.15) × 101 n cm-2 s-1, f = 50.9 ± 1.3 and α = 0.038 ± 0.008. The results for f-values indicate that good thermalization of fast neutrons on the order of 98% was achieved in both sample irradiation sites. This is because an optimum combination of water and paraffin moderator is used in the present configuration. In addition, the shielding requirements are met by using natural boron oxide powder (5.5 cm) and boron loaded paraffin layers against neutrons, and a 15 cm thick lead bricks against gamma-rays from source and its

  3. Plasma scale-length effects on electron energy spectra in high-irradiance laser plasmas

    NASA Astrophysics Data System (ADS)

    Culfa, O.; Tallents, G. J.; Rossall, A. K.; Wagenaars, E.; Ridgers, C. P.; Murphy, C. D.; Dance, R. J.; Gray, R. J.; McKenna, P.; Brown, C. D. R.; James, S. F.; Hoarty, D. J.; Booth, N.; Robinson, A. P. L.; Lancaster, K. L.; Pikuz, S. A.; Faenov, A. Ya.; Kampfer, T.; Schulze, K. S.; Uschmann, I.; Woolsey, N. C.

    2016-04-01

    An analysis of an electron spectrometer used to characterize fast electrons generated by ultraintense (1020W cm-2 ) laser interaction with a preformed plasma of scale length measured by shadowgraphy is presented. The effects of fringing magnetic fields on the electron spectral measurements and the accuracy of density scale-length measurements are evaluated. 2D EPOCH PIC code simulations are found to be in agreement with measurements of the electron energy spectra showing that laser filamentation in plasma preformed by a prepulse is important with longer plasma scale lengths (>8 μ m ).

  4. Computer-simulation analysis of the ESR spectra of V-type centers in irradiated heavy-metal fluoride glasses

    NASA Astrophysics Data System (ADS)

    Griscom, D. L.; Friebele, E. J.

    1991-04-01

    Computer line-shape simulations were carried out on the electron-spin-resonance spectra of several heavy-metal fluoride glasses following exposure to ioniziong radiation at cryogenic temperatures. The primary objects of this study were certain spectra circumstantially attributable to holes trapped on a cluster of two or more inequivalent fluoride or foreign halide ions. The earlier attribution of certain spectral features to FCl- and FBr- species was confirmed in Cl- and Br-doped glasses, respectively, although the simulations show that FCl- in the glasses has a structure quite different from the same species in mixed alkali halide crystals. Two other spectra-universally observed in irradiated glasses composed of ZrF4 (or HfF4), BaF2, and virtually any number of other fluoride constituents-were also examined in detail. The previous assignment of one of these spectral components to F-2 molecular ions is sustained, although the specific nature of these defects is now argued to be interstitial fluorine atoms in configurations analogous to VKA and VH centers (rather than VK centers) in the alkaline-earth fluorides. The second ubiquitous component, which was previously ascribed to ``interstitial F0,'' is demonstrated to arise from an F2-3 species similar to the Vt center in LiF. The F-2 and F2-3 can be thought of as ``on-center'' and ``off-center'' configurations of the interstitial fluorine atom, and it appears that the former may undergo a thermal transmutation into the latter.

  5. Multiplasmon excitations in electron spectra of small systems irradiated by swift charged projectiles

    NASA Astrophysics Data System (ADS)

    Dinh, Phuong Mai; Reinhard, Paul-Gerhard; Suraud, Eric; Wopperer, Philipp

    2015-02-01

    We investigate the kinetic-energy spectrum of electrons emitted from an excited many-electron system, often called photo-electron spectrum (PES). We are particularly interested on the impact of resonant modes of the system on PES. To this end, we consider three systems with strong resonances, a Mg atom, the small alkaline cluster K9+, and the small carbon chain C3. To avoid dominant frequencies in the excitation process, we consider a collision with a fast ion which is realized by an instantaneous boost of the valence electrons, a process which excites all frequencies with equal weight. The electron dynamics is investigated from a theoretical perspective using time-dependent density-functional theory augmented by an average-density self-interaction correction. We observe patterns which are similar to PES usually obtained after irradiation by a laser pulse, in particular the appearance of clear peaks. We show that these patterns are driven by strong resonance modes of the system. Resonances are thus found to be another source of peaks in the PES, besides photons (when present) with definite frequencies.

  6. Multiplasmon excitations in electron spectra of small systems irradiated by swift charged projectiles

    NASA Astrophysics Data System (ADS)

    Dinh, Phuong Mai; Reinhard, Paul-Gerhard; Suraud, Eric; Wopperer, Philipp

    2015-02-01

    We investigate the kinetic-energy spectrum of electrons emitted from an excited many-electron system, often called photo-electron spectrum (PES). We are particularly interested on the impact of resonant modes of the system on PES. To this end, we consider three systems with strong resonances, a Mg atom, the small alkaline cluster K9 +, and the small carbon chain C3. To avoid dominant frequencies in the excitation process, we consider a collision with a fast ion which is realized by an instantaneous boost of the valence electrons, a process which excites all frequencies with equal weight. The electron dynamics is investigated from a theoretical perspective using time-dependent density-functional theory augmented by an average-density self-interaction correction. We observe patterns which are similar to PES usually obtained after irradiation by a laser pulse, in particular the appearance of clear peaks. We show that these patterns are driven by strong resonance modes of the system. Resonances are thus found to be another source of peaks in the PES, besides photons (when present) with definite frequencies.

  7. Numerical Modeling of Indoor Environment with a Ceiling Fan and an Upper-Room Ultraviolet Germicidal Irradiation System

    PubMed Central

    ZHU, SHENGWEI; SREBRIC, JELENA; RUDNICK, STEPHEN N.; VINCENT, RICHARD L.; NARDELL, EDWARD A.

    2013-01-01

    This study proposes a numerical modeling method for the indoor environment with ceiling fans and upper-room ultraviolet germicidal irradiation (UR-UVGI) fixtures. The numerical modeling deployed steady-state Computational Fluid Dynamics (CFD) with a rotating reference frame to simulate the rotation of fan blades. CFD was validated with experimental data of velocity field and fraction of microorganism remaining at the exhaust diffuser. The fraction of microorganism remaining represented the ratio of the concentration of airborne microorganisms measured with UVGI turned on to the one measured with UVGI turned off. According to the validation results, the CFD model correctly reproduced the air movement induced by the rotation of ceiling fan. When the ambient ventilation rate was 2 ACH (air changes per hour) or 6 ACH, the CFD model accurately predicted the average vertical speeds in the section 2.44 m above the floor with the errors less than 10%, regardless of the ceiling fan's rotational direction or speed. In addition, the simulation results showed that the fraction of microorganism remaining increased with the ambient air exchange rate when the fan blew air downward with a rotational speed as high as 235 rpm, which corresponded with the experimental results. Furthermore, the simulation results accurately predicted the fraction of microorganism remaining when the ambient air exchange rate was 2 ACH. We conclude that this novel numerical model can reproduce the effects of ceiling fans and UR-UVGI fixtures on indoor environment, and should aid in the investigation of the impact of ceiling fans on UR-UVGI disinfection efficacy. PMID:24426180

  8. Effect of high-dose irradiation on quality characteristics of ready-to-eat broiler breast fillets stored at room temperature.

    PubMed

    Baptista, R F; Teixeira, C E; Lemos, M; Monteiro, M L G; Vital, H C; Mársico, E T; Júnior, C A Conte; Mano, S B

    2014-10-01

    The effect of high-dose irradiation on the physical, chemical, and bacteriological parameters of ready-to-eat vacuum-packed broiler breast meat after 430 d of storage at room temperature was investigated. Ready-to-eat broiler breast fillets were immersed in brine with garlic powder and then drained, grilled, and vacuum-packed (primary packaging). The high-dose irradiation used was approximately 48 kGy. The treatments were designated as A (irradiated samples stored at room temperature), B (irradiated samples stored at -25°C), and C (nonirradiated samples stored at -25°C). All samples were packaged in polyethylene bags containing aluminum to exclude light (secondary packaging). Proximate composition, pH, 2-thiobarbituric acid reactive substance (TBARS), and heterotrophic aerobic mesophilic bacteria were analyzed during 430 d of storage. Results were analyzed using 1-way ANOVA and the Tukey test. Linear regression was used to analyze the correlation between the results for each parameter and storage time of the different treatments. The gamma radiation caused slight changes (P < 0.05) in the moisture and fat content, regardless of storage temperature. After storage d 110, TBARS values remained stable (P > 0.05) in all the treatments. The preservation methods used were effective in maintaining the mesophilic counts below the detection level during the entire storage period. We concluded that, among the treatments studied, high-dose irradiation with storage at room temperature showed potential for the preservation of ready-to-eat products made from poultry meat, to provide foods safe for consumption.

  9. Monomeric C-phycocyanin at room temperature and 77 K. Resolution of the absorption and fluorescence spectra of the individual chromophores and the energy-transfer rate constants

    SciTech Connect

    Debreczeny, M.P.; Sauer, K. Univ. of California, Berkeley, CA ); Zhou, J.; Bryant, D.A. )

    1993-09-23

    At both room temperature (RT) and 77 K, the absorption and fluorescence spectra of the three individual chromophore types ([alpha][sub 84], [beta][sub 84], and [beta][sub 155]) found in monomeric C-phycocyanin ([alpha][sup PC][beta][sup PC]), isolated from the cyanobacterium Synechococcus sp. PCC 7002, were resolved along with the rates of energy transfer between the chromophores. The cpcB/C155S mutant, whose PC is missing the [beta][sub 155] chromophore, was useful in effecting this resolution. At RT, the single broad peak in the visible region of the absorption spectrum of ([alpha][sup PC][beta][sup PC]) was resolved into its three-component spectra by comparing the steady-state absorption spectra of the isolated wild-type [alpha] subunit of PC ([alpha][sup PC]) (containing only the [alpha][sub 84] chromophore) with those of the monomeric PCs isolated from the mutant strain ([alpha][sup PC][beta]*) and the wild-type strain ([alpha][sup PC][beta][sup PC]). At 77 K, the visible region of the absorption spectrum of ([alpha][sup PC][beta][sup PC]) splits into two peaks. This partial resolution at 77 K of the chromophore spectra of ([alpha][sup PC][beta][sup PC]) when compared with the 77 K absorption spectra of [alpha][sup PC], [beta][sup PC], and ([alpha][sup PC][beta]*) provided a confirmation of our RT assignments of the chromophore absorption spectra. 38 refs., 9 figs., 6 tabs.

  10. Triton Emission Spectra in Some Target Nuclei Irradiated by Ultra-Fast Neutrons

    NASA Astrophysics Data System (ADS)

    Tel, E.; Kaplan, A.; Aydın, A.; Büyükuslu, H.; Demirkol, İ.; Arasoğlu, A.

    2010-08-01

    High-current proton accelerator technologies make use of spallation neutrons produced in ( p,xn) and ( n,xn) nuclear reactions on high-Z targets. The produced neutrons are moderated by heavy water. These moderated neutrons are subsequently captured on 3He to produce tritium via the ( n,p) reaction. Tritium self-sufficiency must be maintained for a commercial power plant. So, working out the systematics of ( n,t) reaction cross sections and triton emission differential data are important for the given reaction taking place on various nuclei at different energies. In this study, triton emission spectra by using ultra-fast neutrons (incident neutron energy >50 MeV), the ( n,xt) reactions for some target nuclei as 16O, 27Al, 56Fe, 59Co, 208Pb and 209Bi have been investigated. In the calculations, the pre-equilibrium and equilibrium effects have been used. The calculated results have been compared with the experimental data taken from the literature.

  11. Ultraviolet (UV)-reflective paint with ultraviolet germicidal irradiation (UVGI) improves decontamination of nosocomial bacteria on hospital room surfaces.

    PubMed

    Jelden, Katelyn C; Gibbs, Shawn G; Smith, Philip W; Hewlett, Angela L; Iwen, Peter C; Schmid, Kendra K; Lowe, John J

    2017-06-01

    An ultraviolet germicidal irradiation (UVGI) generator (the TORCH, ClorDiSys Solutions, Inc.) was used to compare the disinfection of surface coupons (plastic from a bedrail, stainless steel, and chrome-plated light switch cover) in a hospital room with walls coated with ultraviolet (UV)-reflective paint (Lumacept) or standard paint. Each surface coupon was inoculated with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus faecalis (VRE), placed at 6 different sites within a hospital room coated with UV-reflective paint or standard paint, and treated by 10 min UVC exposure (UVC dose of 0-688 mJ/cm(2) between sites with standard paint and 0-553 mJ/cm(2) with UV-reflective paint) in 8 total trials. Aggregated MRSA concentrations on plastic bedrail surface coupons were reduced on average by 3.0 log10 (1.8 log10 Geometric Standard Deviation [GSD]) with standard paint and 4.3 log10 (1.3 log10 GSD) with UV-reflective paint (p = 0.0005) with no significant reduction differences between paints on stainless steel and chrome. Average VRE concentrations were reduced by ≥4.9 log10 (<1.2 log10 GSD) on all surface types with UV-reflective paint and ≤4.1 log10 (<1.7 log10 GSD) with standard paint (p < 0.05). At 5 aggregated sites directly exposed to UVC light, MRSA concentrations on average were reduced by 5.2 log10 (1.4 log10 GSD) with standard paint and 5.1 log10 (1.2 log10 GSD) with UV-reflective paint (p = 0.017) and VRE by 4.4 log10 (1.4 log10 GSD) with standard paint and 5.3 log10 (1.1 log10 GSD) with UV-reflective paint (p < 0.0001). At one indirectly exposed site on the opposite side of the hospital bed from the UVGI generator, MRSA concentrations on average were reduced by 1.3 log10 (1.7 log10 GSD) with standard paint and 4.7 log10 (1.3 log10 GSD) with UV-reflective paint (p < 0.0001) and VRE by 1.2 log10 (1.5 log10 GSD) with standard paint and 4.6 log10 (1.1 log10 GSD) with UV-reflective paint (p < 0.0001). Coating hospital

  12. Line coupling effects in the isotropic Raman spectra of N{sub 2}: A quantum calculation at room temperature

    SciTech Connect

    Thibault, Franck; Boulet, Christian; Ma, Qiancheng

    2014-01-28

    We present quantum calculations of the relaxation matrix for the Q branch of N{sub 2} at room temperature using a recently proposed N{sub 2}-N{sub 2} rigid rotor potential. Close coupling calculations were complemented by coupled states studies at high energies and provide about 10 200 two-body state-to state cross sections from which the needed one-body cross-sections may be obtained. For such temperatures, convergence has to be thoroughly analyzed since such conditions are close to the limit of current computational feasibility. This has been done using complementary calculations based on the energy corrected sudden formalism. Agreement of these quantum predictions with experimental data is good, but the main goal of this work is to provide a benchmark relaxation matrix for testing more approximate methods which remain of a great utility for complex molecular systems at room (and higher) temperatures.

  13. Line Coupling Effects in the Isotropic Raman Spectra of N2: A Quantum Calculation at Room Temperature

    NASA Technical Reports Server (NTRS)

    Thibault, Franck; Boulet, Christian; Ma, Qiancheng

    2014-01-01

    We present quantum calculations of the relaxation matrix for the Q branch of N2 at room temperature using a recently proposed N2-N2 rigid rotor potential. Close coupling calculations were complemented by coupled states studies at high energies and provide about 10200 two-body state-to state cross sections from which the needed one-body cross-sections may be obtained. For such temperatures, convergence has to be thoroughly analyzed since such conditions are close to the limit of current computational feasibility. This has been done using complementary calculations based on the energy corrected sudden formalism. Agreement of these quantum predictions with experimental data is good, but the main goal of this work is to provide a benchmark relaxation matrix for testing more approximate methods which remain of a great utility for complex molecular systems at room (and higher) temperatures.

  14. Facile fabrication of high-performance InGaZnO thin film transistor using hydrogen ion irradiation at room temperature

    SciTech Connect

    Ahn, Byung Du; Park, Jin-Seong; Chung, K. B.

    2014-10-20

    Device performance of InGaZnO (IGZO) thin film transistors (TFTs) are investigated as a function of hydrogen ion irradiation dose at room temperature. Field effect mobility is enhanced, and subthreshold gate swing is improved with the increase of hydrogen ion irradiation dose, and there is no thermal annealing. The electrical device performance is correlated with the electronic structure of IGZO films, such as chemical bonding states, features of the conduction band, and band edge states below the conduction band. The decrease of oxygen deficient bonding and the changes in electronic structure of the conduction band leads to the improvement of device performance in IGZO TFT with an increase of the hydrogen ion irradiation dose.

  15. Study of pulsed signals in UV spectra lines of free atmosphere above Novolazarevskaya station (Antarctica): effect of the solar irradiance?

    NASA Astrophysics Data System (ADS)

    Troshichev, Oleg; Shapovalov, Sergey; Lozovsky, Vladimir

    Study of pulsed signals in UV spectra lines of free atmosphere above Registration of the pulsed signals in zenith of free atmosphere (in range 300-400 nm) was carried out by spectrometer AvaSpec-2048 under the technogenically clear conditions at the Antarctic station Novolazarevskaya. The pulsed signals, with jumps in frequency exceeding by order or more the standard deviation, have been found in five lines, lied in the UV range: 332 nm, 333.5 nm, 342.5 nm, 351.5 nm and 395.2nm. The pulsed signals at the indicated frequencies can be of opposed polarity (the power increases and decreases) with value adequate to the energetic jumps from 0.01 ¨ˆ 0.04 eV/photons. These pulsed signals were compared aı with variations at the appropriate frequencies 331.9 nm, 333.4 nm, 342.5 nm, 351.4 nm and 395.4 nm observed by spectrometer on board the SORCE spacecraft. The certain consistency in the time behavior of values of the mean daily energy standard deviations taking place at Novolazarevskaya (SDE A ) and in SORCE experiment (SDSSI ) has been revealed when passing from the (local) winter to summer conditions (September 01, 2005 to December 17, 2005). The best correlation between pulsed signals detected in the atmospheric and extra-atmospheric conditions is for frequency 333,5 nm. On the other hand, the temporal changes of SDE A for frequency interval 329.5 - 334 nm are consistent with variations in ozone content, measured simultaneously at Novolazarevskya station. Conclusion is made that occurrence of the pulsed signals in UV spectra is of regular character and seems to be related to processes in the Sun. Nevertheless the run of the pulses number turned out to be imperfectly correlated with behavior of the different characteristic of the solar activity. That is why it was suggested that pulsed signals are related to some unknown irradiation, which either takes origin within the Sun or guided by the solar activity. It is suggested that the Earth is constantly exposed to action

  16. Small-Scale Mechanical Testing on Proton Beam-Irradiated 304 SS from Room Temperature to Reactor Operation Temperature

    NASA Astrophysics Data System (ADS)

    Vo, H.; Reichardt, A.; Howard, C.; Abad, M. D.; Kaoumi, D.; Chou, P.; Hosemann, P.

    2015-12-01

    Austenitic stainless steels are common structural components in light water reactors. Because reactor components are subjected to harsh conditions such as high operating temperatures and neutron radiation, they can undergo irradiation-induced embrittlement and related failure, which compromises reliable operation. Small-scale mechanical testing has seen widespread use as a testing method for both ion- and reactor-irradiated materials because it allows access to the mechanical properties of the ion beam-irradiated region, and for safe handling of a small amount of activated material. In this study, nanoindentation and microcompression testing were performed on unirradiated and 10 dpa proton-irradiated 304 SS, from 25°C to 300°C. Increases in yield stress (YS), critical resolved shear stress (CRSS) and hardness ( H) were seen in the irradiated region relative to the unirradiated region. Relationships between H, YS, and CRSS of irradiated and unirradiated materials are discussed over this temperature range.

  17. Room-temperature spin photocurrent spectra at interband excitation and comparison with reflectance-difference spectroscopy in InGaAs/AlGaAs quantum wells

    NASA Astrophysics Data System (ADS)

    Yu, J. L.; Chen, Y. H.; Jiang, C. Y.; Liu, Y.; Ma, H.

    2011-03-01

    Spectra of the interband spin photocurrent due to Rashba and Dresselhaus spin splittings have been experimentally investigated in InGaAs/AlGaAs quantum wells at room temperature. The Rashba- and Dresselhaus-induced circular photogalvanic effect (CPGE) spectra are found to be quite similar in the spectral regions corresponding to the transitions 1e1hh (the first conduction to the first valence sub-band of heavy hole) and 1e2hh. The ratio of Rashba- and Dresselhaus-induced CPGE currents for the transition 1e1hh is estimated to be 4.95. The magnitude of the Rashba-induced CPGE current is up to several tens of nA/W for the transition 1e1hh, which is 1 order of magnitude larger than that obtained in GaN/AlGaN superlattices. Comparing the CPGE spectrum with reflectance-difference and photoreflectance spectra, we find that the large Rashba spin splitting is mainly induced by a large indium atom segregation effect and by the internal field in the quantum wells.

  18. Room temperature and low-temperature absorption and emission spectra of some polypyridylruthenium(II) 3.2.1 complexes

    NASA Astrophysics Data System (ADS)

    Silva, M. I.; Burrows, H. D.; Formosinho, S. J.; Miguel, M. da G.

    2001-05-01

    Electronic absorption and luminescence spectra are reported for a series of complexes of type [Ru(tpy)(L-L)(py)] 2+, where tpy and py are 2,2',2″-terpyridine and pyridine, and L-L represents the bidentate ligands bipyridyl, 4,4'-dimethylbipyridyl, 4-nitrobipyridyl, oxalate and acetylacetonate. The effect of solvent polarity and temperature on their spectral and light emission properties is studied. Energies are reported for the lowest-energy 3MLCT ∗ excited state, and on the basis of these it is suggested that the complexes may make good triplet energy acceptors for use in organic and polymeric light emitting devices.

  19. Measurement of leakage neutron spectra from graphite cylinders irradiated with D-T neutrons for validation of evaluated nuclear data.

    PubMed

    Luo, F; Han, R; Chen, Z; Nie, Y; Shi, F; Zhang, S; Lin, W; Ren, P; Tian, G; Sun, Q; Gou, B; Ruan, X; Ren, J; Ye, M

    2016-10-01

    A benchmark experiment for validation of graphite data evaluated from nuclear data libraries was conducted for 14MeV neutrons irradiated on graphite cylinder samples. The experiments were performed using the benchmark experimental facility at the China Institute of Atomic Energy (CIAE). The leakage neutron spectra from the surface of graphite (Φ13cm×20cm) at 60° and 120° and graphite (Φ13cm×2cm) at 60° were measured by the time-of-flight (TOF) method. The obtained results were compared with the measurements made by the Monte Carlo neutron transport code MCNP-4C with the ENDF/B-VII.1, CENDL-3.1 and JENDL-4.0 libraries. The results obtained from a 20cm-thick sample revealed that the calculation results with CENDL-3.1 and JENDL-4.0 libraries showed good agreements with the experiments conducted in the whole energy region. However, a large discrepancy of approximately 40% was observed below the 3MeV energy region with the ENDF/B-VII.1 library. For the 2cm-thick sample, the calculated results obtained from the abovementioned three libraries could not reproduce the experimental data in the energy range of 5-7MeV. The graphite data in CENDL-3.1 were verified for the first time and were proved to be reliable.

  20. Correlations Between Variations in Solar EUV and Soft X-Ray Irradiance and Photoelectron Energy Spectra Observed on Mars and Earth

    NASA Technical Reports Server (NTRS)

    Peterson, W. K.; Brain, D. A.; Mitchell, D. L.; Bailey, S. M.; Chamberlin, P. C.

    2013-01-01

    Solar extreme ultraviolet (EUV; 10-120 nm) and soft X-ray (XUV; 0-10 nm) radiation are major heat sources for the Mars thermosphere as well as the primary source of ionization that creates the ionosphere. In investigations of Mars thermospheric chemistry and dynamics, solar irradiance models are used to account for variations in this radiation. Because of limited proxies, irradiance models do a poor job of tracking the significant variations in irradiance intensity in the EUV and XUV ranges over solar rotation time scales when the Mars-Sun-Earth angle is large. Recent results from Earth observations show that variations in photoelectron energy spectra are useful monitors of EUV and XUV irradiance variability. Here we investigate photoelectron energy spectra observed by the Mars Global Surveyor (MGS) Electron Reflectometer (ER) and the FAST satellite during the interval in 2005 when Earth, Mars, and the Sun were aligned. The Earth photoelectron data in selected bands correlate well with calculations based on 1 nm resolution observations above 27 nm supplemented by broadband observations and a solar model in the 0-27 nm range. At Mars, we find that instrumental and orbital limitations to the identifications of photoelectron energy spectra in MGS/ER data preclude their use as a monitor of solar EUV and XUV variability. However, observations with higher temporal and energy resolution obtained at lower altitudes on Mars might allow the separation of the solar wind and ionospheric components of electron energy spectra so that they could be used as reliable monitors of variations in solar EUV and XUV irradiance than the time shifted, Earth-based, F(10.7) index currently used.

  1. Ultraviolet and infrared absorption spectra of Cr2O3 doped-sodium metaphosphate, lead metaphosphate and zinc metaphosphate glasses and effects of gamma irradiation: a comparative study.

    PubMed

    Marzouk, M A; ElBatal, F H; Abdelghany, A M

    2013-10-01

    The effects of gamma irradiation on spectral properties of Cr2O3-doped phosphate glasses of three varieties, namely sodium metaphosphate, lead metaphosphate and zinc metaphosphate have been investigated. Optical spectra of the undoped samples reveal strong UV absorption bands which are attributed to the presence of trace iron impurities in both the sodium and zinc phosphate glasses while the lead phosphate glass exhibits broad UV near visible bands due to combined absorption of both trace iron impurities and divalent lead ions. The effect of chromium oxide content has been investigated. The three different Cr2O3-doped phosphate glasses reveal spectral visible bands varying in their position and intensity and splitting due to the different field strengths of the Na(+), Pb(2+), Zn(2+) cations, together with the way they are housed in the network and their effects on the polarisability of neighboring oxygens ligands. The effects of gamma irradiation on the optical spectral properties of the various glasses have been compared. The different effects for lead and zinc phosphate are related to the ability of Pb(2+), and Zn(2+) to form additional structural units causing stability of the network towards gamma irradiation. Also, the introduction of the transition metal chromium ions reveals some shielding behavior towards irradiation. Infrared absorption spectra of the three different base phosphate glasses show characteristic vibrations due to various phosphate groups depending on the type of glass and Cr2O3 is observed to slightly affect the IR spectra. Gamma irradiation causes minor variations in some of the intensities of the IR spectra but the main characteristic bands due to phosphate groups remain in their number and position.

  2. Correlations between variations in solar EUV and soft X-ray irradiance and photoelectron energy spectra observed on Mars and Earth

    NASA Astrophysics Data System (ADS)

    Peterson, W. K.; Brain, D. A.; Mitchell, D. L.; Bailey, S. M.; Chamberlin, P. C.

    2013-11-01

    extreme ultraviolet (EUV; 10-120 nm) and soft X-ray (XUV; 0-10 nm) radiation are major heat sources for the Mars thermosphere as well as the primary source of ionization that creates the ionosphere. In investigations of Mars thermospheric chemistry and dynamics, solar irradiance models are used to account for variations in this radiation. Because of limited proxies, irradiance models do a poor job of tracking the significant variations in irradiance intensity in the EUV and XUV ranges over solar rotation time scales when the Mars-Sun-Earth angle is large. Recent results from Earth observations show that variations in photoelectron energy spectra are useful monitors of EUV and XUV irradiance variability. Here we investigate photoelectron energy spectra observed by the Mars Global Surveyor (MGS) Electron Reflectometer (ER) and the FAST satellite during the interval in 2005 when Earth, Mars, and the Sun were aligned. The Earth photoelectron data in selected bands correlate well with calculations based on 1 nm resolution observations above 27 nm supplemented by broadband observations and a solar model in the 0-27 nm range. At Mars, we find that instrumental and orbital limitations to the identifications of photoelectron energy spectra in MGS/ER data preclude their use as a monitor of solar EUV and XUV variability. However, observations with higher temporal and energy resolution obtained at lower altitudes on Mars might allow the separation of the solar wind and ionospheric components of electron energy spectra so that they could be used as reliable monitors of variations in solar EUV and XUV irradiance than the time shifted, Earth-based, F10.7 index currently used.

  3. EPR Investigation of Irradiated Curry Powder

    SciTech Connect

    Duliu, O. G.; Ali, S. I.; Georgescu, R.

    2007-04-23

    Gamma-ray irradiated curry powder, a well priced oriental spice was investigated in order to establish the ability of EPR to detect the presence and time stability of free irradiation free-radicals. Accordingly, curry powder aliquots were irradiated with gradually increasing absorbed doses up to 11.3 kGy. The EPR spectra of all irradiated samples show the presence of al last two different species of free radicals, whose concentration increased monotonously with the absorbed doses. A 100 deg. C isothermal annealing of irradiated samples has shown a differential reduction of amplitude of various components of the initial spectra, but even after 3.6 h of thermal treatment, the remaining amplitude represents no less then 30% of the initial ones. The same peculiarities have been noticed after more than one year storage at room temperature, all of them being very useful in establishing the existence of any previous irradiation treatment.

  4. EPR Investigation of Irradiated Curry Powder

    NASA Astrophysics Data System (ADS)

    Duliu, O. G.; Ali, S. I.; Georgescu, R.

    2007-04-01

    Gamma-ray irradiated curry powder, a well priced oriental spice was investigated in order to establish the ability of EPR to detect the presence and time stability of free irradiation free-radicals. Accordingly, curry powder aliquots were irradiated with gradually increasing absorbed doses up to 11.3 kGy. The EPR spectra of all irradiated samples show the presence of al last two different species of free radicals, whose concentration increased monotonously with the absorbed doses. A 100° C isothermal annealing of irradiated samples has shown a differential reduction of amplitude of various components of the initial spectra, but even after 3.6 h of thermal treatment, the remaining amplitude represents no less then 30% of the initial ones. The same peculiarities have been noticed after more than one year storage at room temperature, all of them being very useful in establishing the existence of any previous irradiation treatment.

  5. Enhancement of Electrical Properties of TiO2- x Oxide Semiconductor by d-Orbital Ordering Using Swift Heavy Ni-Ion Irradiation at Room Temperature

    NASA Astrophysics Data System (ADS)

    Cho, S. H.; Jun, B. H.; Chung, K. B.

    2017-02-01

    The electrical properties of radiofrequency (RF)-sputtered TiO2- x films have been investigated as a function of Ni-ion irradiation dose at room temperature. The prepared TiO2- x films were irradiated with 130-MeV swift heavy Ni ions in the range from 5 × 1011 ions/cm2 to 1 × 1013 ions/cm2. Increasing the Ni-ion irradiation dose dramatically enhanced the mobility in the TiO2- x films from 2.2 cm2/V s to 1.24 × 102 cm2/V s, while the carrier concentration did not vary. To explain this change in the electrical properties of the TiO2- x films, we investigated various physical properties, namely the physical structure, molecular orbital ordering in the conduction band, and shallow/deep trap states in the band-edge area below the conduction band. We suggest that the improvement in mobility originates from the ordering of the Ti 3 d orbital in the conduction band. In addition, increase of the Ni-ion irradiation dose changed two distinct band-edge states below the conduction band.

  6. Upper critical field and Raman spectra of MgB2 thin films irradiated with low energy oxygen ion

    NASA Astrophysics Data System (ADS)

    Wang, J.; Zhuang, C. G.; Li, J.; Wang, Y. Z.; Feng, Q. R.; Zheng, D. N.

    2009-11-01

    The structure, upper critical field, and Raman spectrum of epitaxial MgB2 thin films irradiated by 300 keV O2+ ions have been investigated. Lattice parameter c expands after irradiation. There is a significant increase in upper critical field in the moderately irradiated films, while the critical temperature is reduced slightly. The values of critical field at zero temperature exhibit a maximum for samples with a moderate irradiation level for the applied magnetic field both perpendicular and parallel to the film surface. The temperature dependence of the anisotropy parameter, which is defined as the ratio of the upper critical field with the field parallel to the film surface and perpendicular to the film surface, reveals that oxygen ion irradiation mainly affects the σ band at a low irradiation level. With increasing irradiation level, π band scattering is strongly enhanced, and finally both bands are in the dirty limit. A broad peak centered around 570 cm-1 is observed in the Raman spectrum of the unirradiated films, and the peak position has a visible redshift in the irradiated samples. In particular, high-frequency spectral structures appear and become dominant, while the E2g broad band diminishes gradually with increasing irradiation fluence. The results are discussed by considering the disorder-induced change in carrier scattering within and between the σ and π bands and a violation of the Raman selection rules due to oxygen ion irradiation.

  7. Effect of Ar ion irradiation on the room temperature ferromagnetism of undoped and Cu-doped rutile TiO2 single crystals

    NASA Astrophysics Data System (ADS)

    Xu, Nan-Nan; Li, Gong-Ping; Lin, Qiao-Lu; Liu, Huan; Bao, Liang-Man

    2016-11-01

    Remarkable room-temperature ferromagnetism was observed both in undoped and Cu-doped rutile TiO2 single crystals (SCs). To tune their magnetism, Ar ion irradiation was quantitatively performed on the two crystals in which the saturation magnetizations for the samples were enhanced distinctively. The post-irradiation led to a spongelike layer in the near surface of the Cu-doped TiO2. Meanwhile, a new CuO-like species present in the sample was found to be dissolved after the post-irradiation. Analyzing the magnetization data unambiguously reveals that the experimentally observed ferromagnetism is related to the intrinsic defects rather than the exotic Cu ions, while these ions are directly involved in boosting the absorption in the visible region. Project supported by the National Natural Science Foundation of China (Grant No. 11575074), the Open Project of State Key laboratory of Crystal Material, Shandong University, China (Grant No. KF1311), the Open Project of Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, China (Grant No. LZUMMM2012003), the Open Project of Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Normal University, China (Grant No. 201204), and the Fundamental Research Funds for the Central Universities, China (Grant No. lzujbky-2015-240).

  8. Comparative study of Monte Carlo particle transport code PHITS and nuclear data processing code NJOY for recoil cross section spectra under neutron irradiation

    NASA Astrophysics Data System (ADS)

    Iwamoto, Yosuke; Ogawa, Tatsuhiko

    2017-04-01

    Because primary knock-on atoms (PKAs) create point defects and clusters in materials that are irradiated with neutrons, it is important to validate the calculations of recoil cross section spectra that are used to estimate radiation damage in materials. Here, the recoil cross section spectra of fission- and fusion-relevant materials were calculated using the Event Generator Mode (EGM) of the Particle and Heavy Ion Transport code System (PHITS) and also using the data processing code NJOY2012 with the nuclear data libraries TENDL2015, ENDF/BVII.1, and JEFF3.2. The heating number, which is the integral of the recoil cross section spectra, was also calculated using PHITS-EGM and compared with data extracted from the ACE files of TENDL2015, ENDF/BVII.1, and JENDL4.0. In general, only a small difference was found between the PKA spectra of PHITS + TENDL2015 and NJOY + TENDL2015. From analyzing the recoil cross section spectra extracted from the nuclear data libraries using NJOY2012, we found that the recoil cross section spectra were incorrect for 72Ge, 75As, 89Y, and 109Ag in the ENDF/B-VII.1 library, and for 90Zr and 55Mn in the JEFF3.2 library. From analyzing the heating number, we found that the data extracted from the ACE file of TENDL2015 for all nuclides were problematic in the neutron capture region because of incorrect data regarding the emitted gamma energy. However, PHITS + TENDL2015 can calculate PKA spectra and heating numbers correctly.

  9. 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.

  10. Light irradiation induces fragmentation of the plasmodium, a novel photomorphogenesis in the true slime mold Physarum polycephalum: action spectra and evidence for involvement of the phytochrome.

    PubMed

    Kakiuchi, Y; Takahashi, T; Murakami, A; Ueda, T

    2001-03-01

    A new photomorphogenesis was found in the plasmodium of the true slime mold Physarum polycephalum: the plasmodium broke temporarily into equal-sized spherical pieces, each containing about eight nuclei, about 5 h after irradiation with light. Action spectroscopic study showed that UVA, blue and far-red lights were effective, while red light inhibited the far-red-induced fragmentation. Difference absorption spectra of both the living plasmodium and the plasmodial homogenate after alternate irradiation with far-red and red light gave two extremes at 750 and 680 nm, which agreed with those for the induction and inhibition of the fragmentation, respectively. A kinetic model similar to that of phytochrome action explained quantitatively the fluence rate-response curves of the fragmentation. Our results indicate that one of the photoreceptors for the plasmodial fragmentation is a phytochrome.

  11. Spectral Irradiance Calibration in the Infrared. Part 4; 1.2-35 micrometer Spectra of Six Standard Stars

    NASA Technical Reports Server (NTRS)

    Cohen, Martin; Witteborn, Fred C.; Walker, Russell, G.; Bregman, Jesse D.; Wooden, Diane H.

    1995-01-01

    Five new absolutely calibrated continuous stellar spectra from 1.2 to 35 microns are presented. The spectra were constructed as far as possible from actual observed spectral fragments taken from the ground, the Kuiper Airborne Observatory (KAO), and the IRAS Low Resolution Spectrometer (LRS). These stars (beta Peg, alpha Boo, beta And, beta Gem, and alpha Hya) augment the author's already created complete absolutely calibrated spectrum for alpha Tau. All these spectra have a common calibration pedigree. The wavelength coverage is ideal for calibration of many existing and proposed ground-based, airborne, and satellite sensors.

  12. Spectral Irradiance Calibration in the Infrared. Part 7; New Composite Spectra, Comparison with Model Atmospheres, and Far-Infrared Extrapolations

    NASA Technical Reports Server (NTRS)

    Cohen, Martin; Witteborn, Fred C.; Carbon, Duane F.; Davies, John K.; Wooden, Diane H.; Bregman, Jesse D.

    1996-01-01

    We present five new absolutely calibrated continuous stellar spectra constructed as far as possible from spectral fragments observed from the ground, the Kuiper Airborne Observatory (KAO), and the IRAS Low Resolution Spectrometer. These stars-alpha Boo, gamma Dra, alpha Cet, gamma Cru, and mu UMa-augment our six, published, absolutely calibrated spectra of K and early-M giants. All spectra have a common calibration pedigree. A revised composite for alpha Boo has been constructed from higher quality spectral fragments than our previously published one. The spectrum of gamma Dra was created in direct response to the needs of instruments aboard the Infrared Space Observatory (ISO); this star's location near the north ecliptic pole renders it highly visible throughout the mission. We compare all our low-resolution composite spectra with Kurucz model atmospheres and find good agreement in shape, with the obvious exception of the SiO fundamental, still lacking in current grids of model atmospheres. The CO fundamental seems slightly too deep in these models, but this could reflect our use of generic models with solar metal abundances rather than models specific to the metallicities of the individual stars. Angular diameters derived from these spectra and models are in excellent agreement with the best observed diameters. The ratio of our adopted Sirius and Vega models is vindicated by spectral observations. We compare IRAS fluxes predicted from our cool stellar spectra with those observed and conclude that, at 12 and 25 microns, flux densities measured by IRAS should be revised downwards by about 4.1% and 5.7%, respectively, for consistency with our absolute calibration. We have provided extrapolated continuum versions of these spectra to 300 microns, in direct support of ISO (PHT and LWS instruments). These spectra are consistent with IRAS flux densities at 60 and 100 microns.

  13. SiC-based neutron detector in quasi-realistic working conditions: efficiency and stability at room and high temperature under fast neutron irradiations

    SciTech Connect

    Ferone, Raffaello; Issa, Fatima; Ottaviani, Laurent; Biondo, Stephane; Vervisch, Vanessa; Szalkai, Dora; Klix, Axel; Vermeeren, Ludo; Saenger, Richard; Lyoussi, Abadallah

    2015-07-01

    In the framework of the European I SMART project, we have designed and made new SiC-based nuclear radiation detectors able to operate in harsh environments and to detect both fast and thermal neutrons. In this paper, we report experimental results of fast neutron irradiation campaign at high temperature (106 deg. C) in quasi-realistic working conditions. Our device does not suffer from high temperature, and spectra do show strong stability, preserving features. These experiments, as well as others in progress, show the I SMART SiC-based device skills to operate in harsh environments, whereas other materials would strongly suffer from degradation. Work is still demanded to test our device at higher temperatures and to enhance efficiency in order to make our device fully exploitable from an industrial point of view. (authors)

  14. Enhanced room temperature oxidation in silicon and porous silicon under 10 keV x-ray irradiation

    SciTech Connect

    Ryckman, Judson D.; Reed, Robert A.; Weller, Robert A.; Fleetwood, D. M.; Weiss, S. M.

    2010-12-01

    We report the observation of enhanced oxidation on silicon and porous silicon samples exposed in air ambient to high-dose-rate 10 keV x-ray radiation at room temperature. The evolution of the radiation-induced oxide growth is monitored by ellipsometry and interferometric reflectance spectroscopy. Fourier transform infrared (FTIR) spectroscopy shows the emergence of Si-O-Si stretching modes and corresponding suppression of SiH{sub x} and Si-Si modes in the porous silicon samples. The radiation response depends strongly on initial native oxide thickness and Si-H surface species. The enhanced oxidation mechanism is attributed to photoinduced oxidation processes wherein energetic photons are used to dissociate molecular oxygen and promote the formation of more reactive oxygen species.

  15. Enhanced room temperature oxidation in silicon and porous silicon under 10 keV x-ray irradiation

    NASA Astrophysics Data System (ADS)

    Ryckman, Judson D.; Reed, Robert A.; Weller, Robert A.; Fleetwood, D. M.; Weiss, S. M.

    2010-12-01

    We report the observation of enhanced oxidation on silicon and porous silicon samples exposed in air ambient to high-dose-rate 10 keV x-ray radiation at room temperature. The evolution of the radiation-induced oxide growth is monitored by ellipsometry and interferometric reflectance spectroscopy. Fourier transform infrared (FTIR) spectroscopy shows the emergence of Si-O-Si stretching modes and corresponding suppression of SiHx and Si-Si modes in the porous silicon samples. The radiation response depends strongly on initial native oxide thickness and Si-H surface species. The enhanced oxidation mechanism is attributed to photoinduced oxidation processes wherein energetic photons are used to dissociate molecular oxygen and promote the formation of more reactive oxygen species.

  16. Thymic serum activity and laser-correlation spectra of patients with lower jaw fracture before and after intravenous laser irradiation

    NASA Astrophysics Data System (ADS)

    Starodub, Nickolaj F.; Selesneva, Tatjana N.; Kovalenko, Vitalij; Pirohova, Ljudmila V.; Ternovoj, Konstantin S.

    1997-12-01

    The problem of jaw-face traumatism is actual in surgical stomatology and fracture of lower jaw make up about 90% from all types of traumas. Number of approaches that include non- specific stimulation of immune system by intravenous laser irradiation were used to raise efficacy of treatment of above indicated fractures. But the application of laser beam irradiation must be controlled by independent biochemical and immunological methods. In particular it is considered the necessity of preliminary analysis of immune system state to determine dose loading of this factor. In dependence on immune system activity the laser beams can promote treatment or reduction of its efficiency. In this report the experimental data about necessity of such control in case of usage of laser beam irradiation are demonstrated. The levels of thymic serum activity (TSA), inhibitors TSA (ITSA) and sub-fractional distribution of substances in blood serum were analyzed in two groups of patients with the fracture of lower jaw: (1) with ordinary treatment and (2) with additional inclusion of number of procedures of laser irradiation. The total quantity of investigated patients was 16. It was shown that: (1) at the irradiation of patients with the normal original TSA level in blood plasma: (a) TSA decreased; (b) ITSA appeared; (c) laser-correlation spectrums changed that indicated about increase of level of substance with less translation mobility and (d) the overall term of recovery increased for 1 day; (2) when the original TSA was lower, above mentioned parameters changed into opposite direction as it is indicated in point 1. So, low intensive laser radiation can have both positive and negative effect in dependent on original organism state.

  17. Spectral Irradiance Calibration in the Infrared. Part 6; 3-35 microns Spectra of Three Southern Standard Stars

    NASA Technical Reports Server (NTRS)

    Cohen, Martin; Witteborn, Fred C.; Bregman, Jesse D.; Wooden, Diane H.; Salama, Alberto; Metcalfe, Leo

    1996-01-01

    We present three new absolutely calibrated continuous stellar spectra from 3 to 35 microns, constructed as far as possible from actual observed spectral fragments taken from the Kuiper Airborne Observatory (KAO), and the IRAS Low Resolution Spectrometer (LRS). These stars- alpha(sup 1) Cen, alpha TrA, and epsilon Car-augment our previous archive of complete absolutely calibrated spectra for northern K and M giants. All these spectra have a common calibration pedigree. The wavelength coverage is ideal for calibration of many existing and proposed ground-based, airborne, and satellite sensors. KAO and IRAS data in the 15-30 micron range suggest that the spectra of cool giants are close to Rayleigh-Jeans slopes. Our observations of alpha(sup 1) Cen, absolutely calibrated via our adopted Sirius model, indicate an angular diameter in very good agreement with values in the literature, demonstrating 'closure' of the set of spectra within our absolute framework. We compare our observed alpha(sup 1) Cen spectrum with a published grid of theoretical models from Kurucz, and adopt a plausible theoretical shape, that fits our spectrum, as a secondary reference spectrum in the southern sky.

  18. Analysis of Electron and Antineutrino Energy Spectra from Fissile Samples under Irradiation based on Gross Theory of Beta-decay

    NASA Astrophysics Data System (ADS)

    Yoshida, T.; Tachibana, T.; Chiba, S.

    2016-06-01

    We applied the gross theory of β-decay to calculate the reactor electron and antineutrino ({{{bar ν }}{e}}) spectra emitted from 235,238U and 239,241Pu by summing up all the contributions from a large number of decaying fission-products (FPs). We make it clear what kinds of transition types and FP nuclides are important to shape the lepton spectra. After taking the ambiguity in the current data for fission yields and Qβ-values into account, we suggested a possibility that the high-energy part of the widely referred electron-spectra by Schreckenbach et al., almost only one experimental data set available now, might possibly be too low. Arguments on a special role of the odd(Z)-odd(N) nuclides and on the consistency between U-238 and other fissiles in the experimental data lead to the importance of a new and independent measurement of electron energy spectra which could be converted into the reactor {{{bar ν }}{e}} spectra.

  19. Characterization by combined optical and FT infrared spectra of 3d-transition metal ions doped-bismuth silicate glasses and effects of gamma irradiation.

    PubMed

    ElBatal, F H; Abdelghany, A M; ElBatal, H A

    2014-03-25

    Optical and infrared absorption spectral measurements were carried out for binary bismuth silicate glass and other derived prepared samples with the same composition and containing additional 0.2% of one of 3d transition metal oxides. The same combined spectroscopic properties were also measured after subjecting the prepared glasses to a gamma dose of 8 Mrad. The experimental optical spectra reveal strong UV-near visible absorption bands from the base and extended to all TMs-doped samples and these specific extended and strong UV-near visible absorption bands are related to the contributions of absorption from both trace iron (Fe(3+)) ions present as contaminated impurities within the raw materials and from absorption of main constituent trivalent bismuth (Bi(3+)) ions. The strong UV-near visible absorption bands are observed to suppress any further UV bands from TM ions. The studied glasses show obvious resistant to gamma irradiation and only small changes are observed upon gamma irradiation. This observed shielding behavior is related to the presence of high Bi(3+) ions with heavy mass causing the observed stability of the optical absorption. Infrared absorption spectra of the studied glasses reveal characteristic vibrational bands due to both modes from silicate network and the sharing of Bi-O linkages and the presence of TMs in the doping level (0.2%) causes no distinct changes within the number or position of the vibrational modes. The presence of high Bi2O3 content (70 mol%) appears to cause stability of the structural building units towards gamma irradiation as revealed by FTIR measurements.

  20. Spectral Irradiance Calibration in the Infrared. 4; 1.2-35um Spectra of Six Standard Stars

    NASA Technical Reports Server (NTRS)

    Cohen, Martin; Witteborn, Fred C.; Walker, Russell G.; Bregman, Jesse D.; Wooden, Diane H.

    1995-01-01

    We present five new absolutely calibrated continuous stellar spectra from 1.2 to 35 microns, constructed as far as possible from actual observed spectral fragments taken from the ground, the Kuiper Airborne Observatory (KAO), and the IRAS Low Resolution Spectrometer (LRS). These stars, Beta Peg, Delta Boo, Beta And, Beta Gem, and Delta Hya, augment our already created complete absolutely calibrated spectrum for a Tau. All these spectra have a common calibration pedigree. The wavelength coverage is ideal for calibration of many existing and proposed ground-based, airborne, and satellite sensors.

  1. Spectral Irradiance Calibration in the Infrared. Part 4; 1.2 - 35 microns Spectra of Six Standard Stars

    NASA Technical Reports Server (NTRS)

    Cohen, Martin; Witteborn, Fred C.; Walker, Russell G.; Bregman, Jesse D.; Wooden, Diane H.

    1995-01-01

    We present five new absolutely calibrated continuous stellar spectra from 1.2 to 35 microns, constructed as far as possible from actual observed spectral fragments taken from the ground, the Kuiper Airborne Observatory (KAO), and the IRAS Low Resolution Spectrometer (LRS). These stars- beta Peg, alpha Boo, beta And, beta Gem, and alpha Hya-augment our already created complete absolutely calibrated spectrum for alpha Tau. All these spectra have a common calibration pedigree. The wavelength coverage is ideal for calibration of many existing and proposed ground-based, airborne, and satellite sensors.

  2. Facile room-temperature synthesis of carboxylated graphene oxide-copper sulfide nanocomposite with high photodegradation and disinfection activities under solar light irradiation

    NASA Astrophysics Data System (ADS)

    Yu, Shuyan; Liu, Jincheng; Zhu, Wenyu; Hu, Zhong-Ting; Lim, Teik-Thye; Yan, Xiaoli

    2015-11-01

    Carboxylic acid functionalized graphene oxide-copper (II) sulfide nanoparticle composite (GO-COOH-CuS) was prepared from carboxylated graphene oxide and copper precursor in dimethyl sulfoxide (DMSO) by a facile synthesis process at room temperature. The high-effective combination, the interaction between GO-COOH sheets and CuS nanoparticles, and the enhanced visible light absorption were confirmed by transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectra (DRS) and Photoluminescence (PL) spectra. The as-synthesized GO-COOH-CuS nanocomposite exhibited excellent photocatalytic degradation performance of phenol and rhodamine B, high antibacterial activity toward E. coli and B. subtilis, and good recovery and reusability. The influence of CuS content, the synergistic reaction between CuS and GO-COOH, and the charge-transfer mechanism were systematically investigated. The facile and low-energy synthesis process combined with the excellent degradation and antibacterial performance signify that the GO-COOH-CuS has a great potential for water treatment application.

  3. Facile room-temperature synthesis of carboxylated graphene oxide-copper sulfide nanocomposite with high photodegradation and disinfection activities under solar light irradiation

    PubMed Central

    Yu, Shuyan; Liu, Jincheng; Zhu, Wenyu; Hu, Zhong-Ting; Lim, Teik-Thye; Yan, Xiaoli

    2015-01-01

    Carboxylic acid functionalized graphene oxide-copper (II) sulfide nanoparticle composite (GO-COOH-CuS) was prepared from carboxylated graphene oxide and copper precursor in dimethyl sulfoxide (DMSO) by a facile synthesis process at room temperature. The high-effective combination, the interaction between GO-COOH sheets and CuS nanoparticles, and the enhanced visible light absorption were confirmed by transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectra (DRS) and Photoluminescence (PL) spectra. The as-synthesized GO-COOH-CuS nanocomposite exhibited excellent photocatalytic degradation performance of phenol and rhodamine B, high antibacterial activity toward E. coli and B. subtilis, and good recovery and reusability. The influence of CuS content, the synergistic reaction between CuS and GO-COOH, and the charge-transfer mechanism were systematically investigated. The facile and low-energy synthesis process combined with the excellent degradation and antibacterial performance signify that the GO-COOH-CuS has a great potential for water treatment application. PMID:26553709

  4. A comparison of the doppler-broadened positron annihilation spectra of neutron irradiated Al 2O 3 and MgAl 2O 3

    NASA Astrophysics Data System (ADS)

    Jones, P. L.; Schaffer, J. P.; Cocks, F. H.; Clinard, F. W.; Hurley, G. F.

    1985-01-01

    Radiation damage studies of oxides and ceramics have become of increasing importance due to the projected use of these materials in thermonuclear fusion reactors as electronic insulators and first wall materials. In addition these materials are important in RAD waste disposal. As part of a study of the defect structure in radiation damaged ceramics Doppler-broadened positron annihilation spectra have been obtained for a series of single crystal sapphire (α-Al 2O 3) and polycrystal (1:1) and (1:2) magnesium aluminate spinel (MgO·Al 2O 3 and MgO-2Al 2O 3) samples. These samples were irradiated in EBR-II to a fluence of 3 × 10 25 n/m 2 (E > 0.1 MeV) at 740°C, and 2 × 10 26 n/m 2 (E > 0.1 MeV) at ~ 550°C respectively. Positron annihilation spectra lineshapes for the irradiated, annealed, and as-received samples of both materials were compared using S parameter analysis. These calculations were made on deconvoluted gamma ray spectra that were free of any instrumental broadening effects. In this way, absolute S parameter changes could be calculated. The observed changes in the S parameter are consistent with independent volume swelling measurements for both the α-A1 2O 3 and the (1:2) MgAl 2O 4 samples. However, the change in S parameter measured for the (1:1) spinel is contrary to the measured volume change. This apparent anomaly indicates a predominence of interstitial as opposed to vacancy type defects in this material.

  5. Comparison of high-resolution solar irradiance spectra and the solar luminosity in the period 1980-1989

    NASA Technical Reports Server (NTRS)

    Mitchell, Walter E., Jr.

    1992-01-01

    In this research, we aim to determine to what extent the solar irradiance changes measured through the 1980's from orbiting vehicles are accompanied by spectroscopic irradiance changes observable from the ground. We describe fractional changes in line absorption as 'blanketing'. In section 2, we briefly review results obtained in an earlier project and which have been published. Section 3 describes the data of this investigation; section 4 describes the data reduction; section 5 describes the observational results in terms of blanketing; and section 6 describes the interpretation of the measured changes. Section 7 contains an outline of possible uses for Doppler-shift data that emerges with the measurements of the blanketing variations. Section 8 is an outline for future research suggested by our results in this project.

  6. Annealing behavior between room temperature and 2000 deg. C of deep level defects in electron-irradiated n-type 4H silicon carbide

    SciTech Connect

    Alfieri, G.; Monakhov, E.V.; Svensson, B.G.; Linnarsson, M.K.

    2005-08-15

    The annealing behavior of irradiation-induced defects in 4H-SiC epitaxial layers grown by chemical-vapor deposition has been systematically studied by means of deep level transient spectroscopy (DLTS). The nitrogen-doped epitaxial layers have been irradiated with 15-MeV electrons at room temperature and an isochronal annealing series from 100 to 2000 deg. C has been performed. The DLTS measurements, which have been carried out in the temperature range from 120 to 630 K after each annealing step, revealed the presence of six electron traps located in the energy range of 0.45-1.6 eV below the conduction-band edge (E{sub c}). The most prominent and stable ones occur at E{sub c}-0.70 eV (labeled Z{sub 1/2}) and E{sub c}-1.60 eV(EH{sub 6/7}). After exhibiting a multistage annealing process over a wide temperature range, presumably caused by reactions with migrating defects, a significant fraction of both Z{sub 1/2} and EH{sub 6/7} (25%) still persists at 2000 deg. C and activation energies for dissociation in excess of 8 and {approx}7.5 eV are estimated for Z{sub 1/2} and EH{sub 6/7}, respectively. On the basis of these results, the identity of Z{sub 1/2} and EH{sub 6/7} is discussed and related to previous assignments in the literature.

  7. Optical vibronic emission spectra for irradiation induced F aggregate centers in single crystal α-Al2O3

    NASA Astrophysics Data System (ADS)

    Mohammad Saliqur, Rahman Abu Zayed; Awata, T.; Yamashita, N.; Xu, Qiu; Atobe, K.

    The optical vibronic emission spectra of the single crystal α-Al2O3 caused by neutron bombardment have been studied. New sharp line features near the 470 nm emission band were found. The phonon side band of the previously found zero-phonon line near the 380 nm emission band is also observed in the present study. Vibronic structures associated with the 470 nm emission band are predominantly featured. The Huang-Rhys factor and the Debye temperature are estimated by a curve fitting method to be 3.2 and 710 K, respectively. It can be seen that the origin of the 470 nm vibronic emission spectra is derived from the F./GRAD_A_398864_O_XML_IMAGES/GRAD_A_398864_O_ILM0001.gif type center.

  8. Action Spectra for the Inhibition of Hypocotyl Growth by Continuous Irradiation in Light and Dark-Grown Sinapis alba L. Seedlings 1

    PubMed Central

    Beggs, Christopher J.; Holmes, M. Geoffrey; Jabben, Merten; Schäfer, Eberhard

    1980-01-01

    Action spectra for the inhibition by continuous (24-hour) irradiation of hypocotyl growth in 54-hour-old Sinapis alba L. seedlings were measured using seedlings which had had four different pretreatments. These seedlings were either (a) dark-grown with a high total phytochrome level, (b) dark-grown with a low total phytochrome level, (c) light-grown with chlorophyll, or (d) light-grown with no chlorophyll [treated with 4-chloro-5-(methylamino)-2-(α,α,α-trifluoro-m-tolyl)-3(2H) -pyridazinone (San 9789)]. The resulting action spectra show that the blue, red, and far-red (716 nm) wavebands are most inhibitory for dark-grown plants with high phytochrome content, whereas hypocotyl growth in dark-grown plants with a low phytochrome content are only slightly inhibited by blue and far-red radiation. In light-grown plants, the effectiveness of blue and far-red light almost disappears. The position of red light effectiveness in chlorophyll-containing plants is shifted to lower wavelengths compared with those containing no chlorophyll. PMID:16661489

  9. Temperature coefficients of monolithic III-V triple-junction solar cells under different spectra and irradiance levels

    NASA Astrophysics Data System (ADS)

    Fernández, E. F.; Siefer, G.; Schachtner, M.; García Loureiro, A. J.; Pérez-Higueras, P.

    2012-10-01

    A complete set of temperature coefficients determined under controlled laboratory conditions is reported for a lattice-matched Ga0.50In0.50P/Ga0.99In0.01As/Ge and metamorphic (MM) Ga0.35In0.65P/Ga0.83In0.17As/Ge triple-junction solar cell. The cells have been investigated at one sun condition at different temperatures and spectra in order to identify a possible influence of the spectrum on the temperature coefficients. At the same time, the cells have been investigated at different temperatures and concentration levels to study the behaviour of the temperature coefficients under concentration.

  10. Creation of nanosize defects in LiF crystals under 5- and 10-MeV Au ion irradiation at room temperature

    SciTech Connect

    Lushchik, A.; Lushchik, Ch.; Vasil'chenko, E.; Schwartz, K.; Neumann, R.; Trautmann, C.; Papaleo, R.; Sorokin, M.; Volkov, A. E.

    2007-08-01

    Investigation of radiation defects induced by the irradiation of LiF crystals with 5- or 10-MeV Au ions (fluences of 10{sup 11}-2x10{sup 14} ions/cm{sup 2}; flux varies by 2 orders of magnitude) at room temperature has been performed using the methods of optical absorption and high-temperature (400-750 K) thermoactivation spectroscopy. The creation efficiency of color centers (F,F{sub 2},F{sub 3},...) and colloids drastically depends on both the fluence and ion flux (beam current). Besides impurity (magnesium) colloids with the absorption band peaked at 4.4-4.6 eV, the broad absorption band at 2.3-3.3 eV related to intrinsic Li colloids is reliably distinguished. The creation efficiency of Li colloids by 5-MeV Au ions is lower than that by 10-MeV ions, which form {delta} electrons with higher energies sufficient for the creation of cation excitons ({approx}62 eV). The cation exciton decays, in turn, with the formation of a group of spatially close F centers. At a high ion flux, the next bombarding ions hit the same crystal region with a small time delay (10-100 s) and also form, after similar intermediate processes, the groups of F centers that participate in the formation of stable agglomerates of several F{sub 3} or even more complex centers, which serve as stable (up to 620 K) seeds for nanosize Li colloids. The peculiarities of the formation, enlargement, and annealing of intrinsic colloids in LiF crystals are considered, invoking a formal analog with the processes in photographic materials based on silver halides.

  11. Electron irradiation effects on optical properties of semiorganic antimony thiourea tetra chloride single crystals.

    PubMed

    Mahesha Upadhya, K; Udayashankar, N K; Ganesh, S

    2012-11-01

    Antimony thiourea tetra chloride single crystals were grown by solution growth technique at room temperature. The UV-visible, fourier transform infrared and fluorescence spectra were recorded and electron irradiation effects on these properties were studied. The optical absorption edge of the UV-visible spectrum slightly shifts towards longer wavelength with the increase of irradiation dose. The fluorescence quantum yield is decreased for electron irradiated antimony thiourea tetra chloride crystals. The presence of functional group of the as-grown and electron irradiated complex was confirmed by fourier transform infrared spectral study. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Electron irradiation effects on optical properties of semiorganic antimony thiourea tetra chloride single crystals

    NASA Astrophysics Data System (ADS)

    Mahesha Upadhya, K.; Udayashankar, N. K.; Ganesh, S.

    2012-11-01

    Antimony thiourea tetra chloride single crystals were grown by solution growth technique at room temperature. The UV-visible, fourier transform infrared and fluorescence spectra were recorded and electron irradiation effects on these properties were studied. The optical absorption edge of the UV-visible spectrum slightly shifts towards longer wavelength with the increase of irradiation dose. The fluorescence quantum yield is decreased for electron irradiated antimony thiourea tetra chloride crystals. The presence of functional group of the as-grown and electron irradiated complex was confirmed by fourier transform infrared spectral study.

  13. Temperature and dose dependency of free radicals in irradiated poly(ethylene terephthalate)

    NASA Astrophysics Data System (ADS)

    Rao, B. S.; Sridhar, V.; Indira, S.; Punnaiah, G.; Venkatapparao, T.

    2006-01-01

    The nature of free radicals produced in gamma-irradiated poly(ethylene terephthalate) (PET) has been studied by the electron spin resonance (ESR) and Fourier transform infrared (FTIR) techniques. ESR and FTIR spectra of irradiated PET are recorded at different temperatures and radiation doses, to observe the behaviour of free radicals. The ESR spectrum of PET irradiated to a radiation dose of 3.0 Mrad at room temperature consists of more than four hyperfine lines. The spectrum is simulated to be a superposition of component spectra arising from macroradicals similar to CH2-CH similar to and radicals of the type similar to CH- and/or similar to CO-C6H3-CO similar to together with a difference singlet due to O-CH2 similar to radicals. ESR spectra of irradiated PET were also recorded from RT to 430 K. The hyperfine structure gradually goes down with temperature and around 430 K the signal completely vanishes. The spectra were also simulated at different temperatures. The macroradical intensity gradually decreases, whereas the intensity of the doublet is stable up to 350 K. The dose dependency of free radicals produced in gamma-irradiated PET has also been investigated by recording the ESR spectra at various radiation doses. FTIR spectra of pure and irradiated PET have been recorded to identify chemical changes occurring on irradiation of the polymer.

  14. Infrared and Raman spectroscopies of refractory residues left over after ion irradiation of nitrogen-bearing icy mixtures

    NASA Astrophysics Data System (ADS)

    Palumbo, M. E.; Ferini, G.; Baratta, G. A.

    Using infrared and Raman spectroscopies, we have studied the effects induced by ion irradiation on icy mixtures at low temperature (T=12 K) and after warm up to room temperature. In particular, we have considered mixtures made of H2O, CO, CH4, and N2. These mixtures have been irradiated with 30 keV He+ and 60 keV Ar2+ ions. After ion irradiation at low temperature, several new absorption features appear in the infrared spectra, some of which may be due to N-bearing molecular species. A refractory organic residue is left over after warm-up to room temperature. After further irradiation of the residue at room temperature, the intensity of all infrared absorption features decreases. Raman spectroscopy of similar mixtures has shown that ion irradiation causes a modification of the structure of the samples which evolve towards an amorphous carbon.

  15. TU-F-CAMPUS-T-01: Dose and Energy Spectra From Neutron Induced Radioactivity in Medical Linear Accelerators Following High Energy Total Body Irradiation

    SciTech Connect

    Keehan, S; Taylor, M; Franich, R; Smith, R; Dunn, L; Kron, T

    2015-06-15

    Purpose: To assess the risk posed by neutron induced activation of components in medical linear accelerators (linacs) following the delivery of high monitor unit 18 MV photon beams such as used in TBI. Methods: Gamma spectroscopy was used to identify radioisotopes produced in components of a Varian 21EX and an Elekta Synergy following delivery of photon beams. Dose and risk estimates for TBI were assessed using dose deliveries from an actual patient treatment. A 1 litre spherical ion chamber (PTW, Germany) has been used to measure the dose at the beam exit window and at the total body irradiation (TBI) treatment couch following large and small field beams with long beam-on times. Measurements were also made outside of the closed jaws to quantify the benefit of the attenuation provided by the jaws. Results: The radioisotopes produced in the linac head have been identified as {sup 187}W, {sup 56}Mn, {sup 24}Na and {sup 28}Al, which have half-lives from between 2.3 min to 24 hours. The dose at the beam exit window following an 18 MV 2197 MU TBI beam delivery was 12.6 µSv in ten minutes. The dose rate at the TBI treatment couch 4.8 m away is a factor of ten lower. For a typical TBI delivered in six fractions each consisting of four beams and an annual patient load of 24, the annual dose estimate for a staff member at the treatment couch for ten minutes is 750 µSv. This can be further reduced by a factor of about twelve if the jaws are closed before entering the room, resulting in a dose estimate of 65 µSv. Conclusion: The dose resulting from the activation products for a representative TBI workload at our clinic of 24 patients per year is 750 µSv, which can be further reduced to 65 µSv by closing the jaws.

  16. EPR investigation of some traditional oriental irradiated spices

    NASA Astrophysics Data System (ADS)

    Duliu, Octavian G.; Georgescu, Rodica; Ali, Shaban Ibrahim

    2007-06-01

    The 9.50 GHz electron paramagnetic resonance (EPR) spectra of unirradiated and 60Co γ-ray irradiated cardamom ( Elettaria cardamomum L. Maton, Zingiberaceae), ginger (( Zingiber officinale Rosc., Zingiberaceae), and saffron ( Crocus sativus L., Iridaceae) have been investigated at room temperature. All unirradiated spices presented a weak resonance line with g-factors around free-electron ones. After γ-ray irradiation at an absorbed dose of up to 11.3 kGy, the presence of EPR spectra whose amplitude increase monotonously with the absorbed dose has been noticed with all spices. A 100 °C isothermal annealing of 11.3 kGy irradiated samples has shown a differential reduction of amplitude of various components that compose initial spectra, but even after 3.6 h of thermal treatment, the remaining amplitude represents no less then 30% of the initial ones. The same peculiarities have been noticed after 83 days storage at room temperature but after 340 days storage at ambient conditions only irradiated ginger displays a weak signal that differs from those of unirradiated sample. All these factors could be taken into account in establishing at which extent the EPR is suitable to evidence any irradiation treatment applied to these spices.

  17. Point defects and magnetic properties of neutron irradiated MgO single crystal

    NASA Astrophysics Data System (ADS)

    Cao, Mengxiong; Ma, Yaru; Wang, Xingyu; Ma, Chunlin; Zhou, Weiping; Wang, Xiaoxiong; Tan, Weishi; Du, Jun

    2017-05-01

    (100)-oriented MgO single crystals were irradiated to introduce point defects with different neutron doses ranging from 1.0×1016 to 1.0×1020 cm-2. The point defect configurations were studied with X-ray diffuse scattering and UV-Vis absorption spectra. The isointensity profiles of X-ray diffuse scattering caused by the cubic and double-force point defects in MgO were theoretically calculated based on the Huang scattering theory. The magnetic properties at different temperature were measured with superconducting quantum interference device (SQUID). The reciprocal space mappings (RSMs) of irradiated MgO revealed notable diffuse scattering. The UV-Vis spectra indicated the presence of O Frenkel defects in irradiated MgO. Neutron-irradiated MgO was diamagnetic at room temperature and became ferromagnetic at low temperature due to O Frenkel defects induced by neutron-irradiation.

  18. Impact of neutron irradiation on thermal helium desorption from iron

    NASA Astrophysics Data System (ADS)

    Hu, Xunxiang; Field, Kevin G.; Taller, Stephen; Katoh, Yutai; Wirth, Brian D.

    2017-06-01

    The synergistic effect of neutron irradiation and transmutant helium production is an important concern for the application of iron-based alloys as structural materials in fission and fusion reactors. In this study, we investigated the impact of neutron irradiation on thermal helium desorption behavior in high purity iron. Single crystalline and polycrystalline iron samples were neutron irradiated in HFIR to 5 dpa at 300 °C and in BOR-60 to 16.6 dpa at 386 °C, respectively. Following neutron irradiation, 10 keV He ion implantation was performed at room temperature on both samples to a fluence of 7 × 1018 He/m2. Thermal desorption spectrometry (TDS) was conducted to assess the helium diffusion and clustering kinetics by analyzing the desorption spectra. The comparison of He desorption spectra between unirradiated and neutron irradiated samples showed that the major He desorption peaks shift to higher temperatures for the neutron-irradiated iron samples, implying that strong trapping sites for He were produced during neutron irradiation, which appeared to be nm-sized cavities through TEM examination. The underlying mechanisms controlling the helium trapping and desorption behavior were deduced by assessing changes in the microstructure, as characterized by TEM, of the neutron irradiated samples before and after TDS measurements.

  19. Irradiation detection of coffee mate by electron spin resonance (ESR)

    NASA Astrophysics Data System (ADS)

    Özsayin, Fulya; Polat, Mustafa

    2011-06-01

    Un-irradiated coffee mate samples do not exhibit any ESR signal. However, the samples exposed to UV and gamma radiation exhibit an ESR singlet and a large unresolved ESR signal, respectively. The dose-response curves of the samples exposed to UV and gamma radiations were found to be described well by an exponential and linear functions, respectively. Variable temperature and fading studies at room temperature showed that the radiation-induced radicals in coffee mate sample are very sensitive to temperature. The discrimination between un-irradiated and irradiated coffee mate samples can be done just comparing their ESR spectra. However, determination of the radiation dose received by the sample cannot be possible because of the fast decay of signal intensity at room temperature.

  20. Effect of temperature and recoil-energy spectra on irradiation-induced amorphization in Ca{sub 2}La{sub 8}(SiO{sub 4}){sub 6}O{sub 2}

    SciTech Connect

    Weber, W.J.; Wang, L.M.

    1993-09-01

    Single crystals of Ca{sub 2}La{sub 8}(SiO{sub 4}){sub 6}O{sub 2} have been irradiated with different ions/energies in an in situ study of the effects of temperature and recoil-energy spectra on irradiation-induced amorphization. The dose for complete amorphization increases with temperature in two stages. The low-temperature stage (below 250 K) has an activation energy of 0.01 {plus_minus} 0.003 eV and is believed to be associated with simultaneous close-pair recombination. The high-temperature stage (above 250 K) has an activation energy of 0.13 {plus_minus} 0.02 eV and may be associated with irradiation-enhanced defect mobility. The critical temperature for amorphization increases from {approximately}360 K for 0.8 MeV Ne{sup +} to {approximately}710 K for 1.5 MeV Kr{sup +}. At 15 K, the amorphization dose is {approximately}0.36 dpa and is independent of recoil-energy spectra. The amorphization dose increases more rapidly with temperature for Ne{sup +} due to the larger fraction of mobile defects produced by the low energy recoils. The temperature dependence is similar for 1.0 MeV Ar{sup +}, 1.5 MeV Kr{sup +}, and 1.5 MeV Xe{sup +}.

  1. ESR of gamma irradiated single crystals of cholesteryl acetate and cholesteryl chloroformate

    NASA Astrophysics Data System (ADS)

    Yigit, B. T.; Ozmen, A.; Ercan, I.; Eken, M.; Birey, M.

    2003-11-01

    Cholesteryl acetate and cholesteryl chloroformate compounds have been irradiated with Co-60-gamma rays at room temperatures. The irradiated samples have been examined for paramagnetic resonance, and the observed spectra in several cases have been identified with specific radicals. The results in each case have been considered in relation to the present knowledge of the radiation chemistry of the compound. The single crystals have been investigated between 120 and 300 K. The spectra are found to be temperature independent and radiation damage centers are attributed to CHCH2 radical for cholesteryl acetate and CH3 and CHCH2CH2CH2 radicals for cholesteryl chloroformate.

  2. EPR of gamma irradiated single crystals of cholesteryl benzoate

    NASA Astrophysics Data System (ADS)

    Caliskan, B.; Aras, E.; Asik, B.; Buyum, M.; Birey, M.

    2004-01-01

    The cholesteryl benzoate compound has been irradiated with Co-60-gamma rays at room temperature. The irradiated samples have been examined for paramagnetic resonance, and in several cases the observed spectra could be identified with specific radicals. In each case the results have been considered in relation to the present knowledge of the radiation chemistry of the compound. The single crystals have been investigated between 123 and 300 K. The spectrum parameters are found to be temperature independent. Radiation damage centers are attributed to CHCH2 and CHCH2CH2 radicals. The g values and the hyperfine coupling constants of the unpaired electron with the protons were determined.

  3. Study of dose-response and radical decay curves of gamma irradiated norfloxacin using EPR spectroscopy

    NASA Astrophysics Data System (ADS)

    Sütçü, Kerem; Osmanoǧlu, Yunus Emre

    2017-02-01

    In this study, Electron Paramagnetic Resonance (EPR) spectra of unirradiated and γ-irradiated at doses of 1, 5, 10, 12 and 15 kGy norfloxacin (NOF) were investigated. Before irradiation no EPR signal were observed. After irradiation a weak singlet signal at g = 2.0039 were obtained at room temperature. In order to describe the variation of EPR signal intensity with absorbed radiation dose, several mathematical equations were tried. Increasing irradiation dose up to 15 kGy has increased the signal intensity of the central signal however, no significant changes were observed in g spectroscopic splitting factor. The stability of signal intensity of irradiated NOF was studied over a storage period of 200 days. According to analyses conducted, EPR spectroscopy can be used to distinguish irradiated and unirradiated samples from each other.

  4. Room-temperature spin-oriented photocurrent under near-infrared irradiation and comparison of optical means with Shubnikov de-Haas measurements in AlxGa1-xN/GaN heterostructures

    NASA Astrophysics Data System (ADS)

    Tang, Y. Q.; Shen, B.; He, X. W.; Han, K.; Tang, N.; Chen, W. H.; Yang, Z. J.; Zhang, G. Y.; Chen, Y. H.; Tang, C. G.; Wang, Z. G.; Cho, K. S.; Chen, Y. F.

    2007-08-01

    The admixture of linear and circular photogalvanic effects and (CPGEs) in AlxGa1-xN/GaN heterostructures has been investigated quantitatively by near-infrared irradiation at room temperature. The spin-based photocurrent that the authors have observed solidly indicates the sizable spin-orbital interaction of the two-dimensional electron gas in the heterostructures. Further analysis shows consistency between studies by optical and magnetic (Shubnikov de-Haas) measurements on the spin-orbital coupling effects among different AlxGa1-xN/GaN heterostructures, indicating that the CPGE measurement is a good way to investigate the spin splitting and the spin polarization in semiconductors.

  5. Room-temperature fracture in V-(4-5)Cr-(4-5)Ti tensile specimens irradiated in Fusion-1 BOR-60 experiment

    SciTech Connect

    Gazda, J.; Meshii, M.; Tsai, H.

    1998-09-01

    Specimens of V-(4-5)Cr-(4-5)Ti alloys were irradiated to {approx}18 dpa at 320 C in the Fusion-1 capsule inserted into the BOR-60 reactor. Tensile tests at 23 C indicated dramatic yield strength increase (>300%), lack of work hardening, and minimal (<1%) total elongations. SEM analysis of fracture and side surfaces were conducted to determine reduction in are and the mode of fracture. The reduction of area was negligible. All but one specimen failed by a combination of ductile shear deformation and cleavage crack growth. Transgranular cleavage cracks were initiated by stress concentrations at the tips of the shear bands. In side-view observations, evidence was found of slip bands typically associated with dislocation channeling. No differences due to pre-irradiation heat treatment and heat-to-heat composition variations were detected. The only deviation from this behavior was found in V-4Cr-4Ti-B alloy, which failed in the grip portion by complete cleavage cracking.

  6. Improved x-ray spectroscopy with room temperature CZT detectors.

    PubMed

    Fritz, Shannon G; Shikhaliev, Polad M; Matthews, Kenneth L

    2011-09-07

    Compact, room temperature x-ray spectroscopy detectors are of interest in many areas including diagnostic x-ray imaging, radiation protection and dosimetry. Room temperature cadmium zinc telluride (CZT) semiconductor detectors are promising candidates for these applications. One of the major problems for CZT detectors is low-energy tailing of the energy spectrum due to hole trapping. Spectral post-correction methods to correct the tailing effect do not work well for a number of reasons; thus it is advisable to eliminate the hole trapping effect in CZT using physical methods rather than correcting an already deteriorated energy spectrum. One method is using a CZT detector with an electrode configuration which modifies the electric field in the CZT volume to decrease low-energy tailing. Another method is to irradiate the CZT surface at a tilted angle, which modifies depth of interaction to decrease low-energy tailing. Neither method alone, however, eliminates the tailing effect. In this work, we have investigated the combination of modified electric field and tilted angle irradiation in a single detector to further decrease spectral tailing. A planar CZT detector with 10 × 10 × 3 mm³ size and CZT detector with 5 × 5 × 5 mm³ size and cap-shaped electrode were used in this study. The cap-shaped electrode (referred to as CAPture technology) modifies the electric field distribution in the CZT volume and decreases the spectral tailing effect. The detectors were investigated at 90° (normal) and 30° (tilted angle) irradiation modes. Two isotope sources with 59.6 and 122 keV photon energies were used for gamma-ray spectroscopy experiments. X-ray spectroscopy was performed using collimated beams at 60, 80 and 120 kVp tube voltages, in both normal and tilted angle irradiation. Measured x-ray spectra were corrected for K x-ray escape fractions that were calculated using Monte Carlo methods. The x-ray spectra measured with tilted angle CAPture detector at 60, 80 and 120

  7. Room Acoustics

    NASA Astrophysics Data System (ADS)

    Kuttruff, Heinrich; Mommertz, Eckard

    The traditional task of room acoustics is to create or formulate conditions which ensure the best possible propagation of sound in a room from a sound source to a listener. Thus, objects of room acoustics are in particular assembly halls of all kinds, such as auditoria and lecture halls, conference rooms, theaters, concert halls or churches. Already at this point, it has to be pointed out that these conditions essentially depend on the question if speech or music should be transmitted; in the first case, the criterion for transmission quality is good speech intelligibility, in the other case, however, the success of room-acoustical efforts depends on other factors that cannot be quantified that easily, not least it also depends on the hearing habits of the listeners. In any case, absolutely "good acoustics" of a room do not exist.

  8. The use of commercial glass as a potential gamma accidental dosimeter through the absorption spectra

    NASA Astrophysics Data System (ADS)

    Kharita, M. H.; Yousef, S.; Bakr, S.

    2012-05-01

    Various types of commercial glass (ordinary windows, cathode ray tubes, glass kitchenware) have been studied as potential accidental radiation dosimeters. The proposed method utilizes the changes in the glasses' absorption spectra as a result of irradiation. A 60Co gamma irradiation cell has been used to irradiate samples with doses ranging from 5 to 200 Gy. The transmittance was measured using a photospectrometer (UV-visible spectrometry). The results demonstrate that the transmittance spectra of most of the glass samples change in linear proportion to the exposure dose. Moreover, the study considers the fading effect on the absorption spectra of the irradiated samples for fading times up to 100 days at room temperature. The results of this work demonstrate that several widely used types of glass can be used as high-dose accidental dosimeters for doses ranging between 8 and 200 Gy. A reasonable calibration line can be established for any irradiated glass sample by heating, re-irradiating with standard doses and measuring the related absorption coefficient. Further investigations are needed to decrease the minimum detectable dose of the proposed method and to study the effect of glass composition on radiation response.

  9. Identification of gamma-irradiated fruit juices by EPR spectroscopy

    NASA Astrophysics Data System (ADS)

    Aleksieva, K. I.; Dimov, K. G.; Yordanov, N. D.

    2014-10-01

    The results of electron paramagnetic resonance (EPR) study on commercially available juices from various fruits and different fruit contents: 25%, 40%, 50%, and 100%, homemade juices, nectars and concentrated fruit syrups, before and after gamma-irradiation are reported. In order to remove water from non- and irradiated samples all juices and nectars were filtered; the solid residue was washed with alcohol and dried at room temperature. Only concentrated fruit syrups were dried for 60 min at 40 °C in a standard laboratory oven. All samples under study show a singlet EPR line with g=2.0025 before irradiation with exception of concentrated fruit syrups, which are EPR silent. Irradiation of juice samples gives rise to complex EPR spectra which gradually transferred to "cellulose-like" EPR spectrum from 25% to 100% fruit content. Concentrated fruit syrups show typical "sugar-like" spectra due to added saccharides. All EPR spectra are characteristic and can prove radiation treatment. The fading kinetics of radiation-induced EPR signals were studied for a period of 60 days after irradiation.

  10. BIOLOGICAL IRRADIATION FACILITY

    DOEpatents

    McCorkle, W.H.; Cern, H.S.

    1962-04-24

    A facility for irradiating biological specimens with neutrons is described. It includes a reactor wherein the core is off center in a reflector. A high-exposure room is located outside the reactor on the side nearest the core while a low-exposure room is located on the opposite side. Means for converting thermal neutrons to fast neutrons are movably disposed between the reactor core and the high and low-exposure rooms. (AEC)

  11. Spectral Irradiance Calibration in the Infrared. XVI. Improved Accuracy in the Infrared Spectra of the Secondary and Tertiary Standard Calibration Stars

    DTIC Science & Technology

    2006-10-01

    Paper XIII) E created template spectra for faint standards to calibrate the Infra- .9 red Array Camera ( IRAC ) on Spitzer. In their calibration of... IRAC , a . Reach et al. (2005) noted a systematic 5%-7% difference between ’a the camera calibration against the A stars compared to that from - the K

  12. Characterization of neutron flux spectra in irradiation sites of MNSR reactor using the Westcott-formalism for the k0 neutron activation analysis method.

    PubMed

    Akaho, E H K; Nyarko, B J B

    2002-08-01

    For the general applicability of the k0-NAA method to deal with "non-l/v" (n,gamma) reaction nuclides, the modified spectral index r(alpha) square root (Tn/T0) and g(Tn) factor for monitoring neutron temperature Tn for the inner and outer irradiation sites of the Ghana MNSR reactor (GHARR-1) were measured using the Cd-ratio method. Using the measured Cd ratio for lutetium and the modified spectral index, the reduced resonance integral of lutetium s0,Lu was also calculated. The computed result of 1.64 was in good agreement with the reported value of 1.67. Based on the assumption that the definitions of reaction rates in the Westcott-formalism and in Nisle's unified formulation are equal, a theoretical verification of the accuracy of the measured modified spectral indices for our data and those reported in the literature for other research reactors was carried out. Employing 197Au, 96Zr and 94Zr as "1/v" monitors, the theoretical values which depend on the choice of the monitor, followed the trend for measured values of the sub- to epi-cadmium flux ratio f for nine irradiation sites of four different research reactors. The computed and experimental modified spectral indices for the different flux ratios associated with irradiation sites within the range 18.8-152 fitted well to a simple exponential relationship. Calculated and measured data are in good agreement when appropriate correction factors are used.

  13. Guidelines for the application of upper-room ultraviolet germicidal irradiation for preventing transmission of airborne contagion -- Part 2: Design and operation guidance

    SciTech Connect

    First, M.W.; Nardell, E.A.; Chaisson, W.; Riley, R.

    1999-07-01

    Installations of ultraviolet germicidal irradiation (UVGI) have been stimulated recently by a sudden rise in the incidence of tuberculosis. Hospitals, jails, and homeless shelters have been the most frequently equipped facilities because they are places where many tuberculosis cases are found, the buildings housing them tend to be old and not suited for economical increases in air exchange rates, and the work staffs have been apprehensive about transmission to themselves and their families. The diversity in structures currently being equipped with UVGI installations, plus the introduction of new designs of lamps and fixtures, have made it clear that an updated review of equipment performance factors and practical installation guidelines will be useful to interested parties. Illustrative examples are given of installations that have been made in a diverse set of facilities. In addition, representative figures are given to compare the cost of HVAC installations and UVGI installations that give an equivalent number of air changes based on equal levels of reduction in airborne microorganisms.

  14. Theoretical and experimental studies of CH3X-Y2 rotational line shapes for atmospheric spectra modelling: application to room-temperature CH3Cl-O2.

    PubMed

    Buldyreva, Jeanna; Guinet, Mickaël; Eliet, Sophie; Hindle, Francis; Mouret, Gaël; Bocquet, Robin; Cuisset, Arnaud

    2011-12-07

    The case of symmetric tops CH(3)X (X = Br, Cl, F, …) perturbed by non-polar diatoms Y(2) (Y = N(2), O(2), …) is analysed from the viewpoint of theoretical collisional broadening of their rotational lines observed in atmospheric spectra. A semi-classical approach involving an exponential representation of the scattering operator and exact trajectories governed by the isotropic potential is presented. For the first time the active molecule is strictly treated as a symmetric top and the atom-atom interactions are included in the intermolecular potential model. It is shown for the CH(3)Cl-O(2) system that these interactions contribute significantly to the line width for all values of the rotational quantum numbers J and K. Additional testing of modifications required in the semi-classical formalism for a correct application of the cumulant expansion is performed and it is shown that the use of the cumulant average on the rotational states of the perturbing molecule leads to entirely negligible effects for the not very strongly interacting CH(3)Cl-O(2) system. In order to check the theoretical predictions and to extend the scarce experimental data available in the literature to higher values of the rotational quantum numbers, new measurements of room-temperature O(2)-broadened CH(3)Cl rotational lines are carried out by a photomixing continuous-wave terahertz spectrometer. The experimental line widths extracted with a Voigt profile model demonstrate an excellent agreement with theoretical results up to very high J-values (J = 31, 37, 40, 45, 50).

  15. The effect of gamma irradiation on curcumin component of Curcuma domestica

    NASA Astrophysics Data System (ADS)

    Chosdu, R.; Erizal; Iriawan, T.; Hilmy, N.

    1995-02-01

    The effect of gamma irradiation on curcumin component of Curcuma domestica rhizome were investigated. Pure curcumin, sliced and powdered rhizome with 10% of moisture content were irradiated at 0, 10, 30 and 50 kGy (dose rate of 6 kGy/h). Curcumin content was analysed using HPLC method and ESR spectra. Results show that free radicals are already present in unirradiated rhizome. Gamma irradiation at the doses of 10, 30 and 50 kGy induced the free radicals formation of pure curcumin and Curcuma domestica rhizome. The ESR spectra of irradiated rhizome gave a very similar spectra to the signal of irradiated pure curcumin. The percentage of free radicals intensity from pure curcumin was very stable at room temperature up to 670 hours of storage. However, the percentage intensity of free radicals in the irradiated rhizome were decay during storage. Irradiation treatment and storage time did not give a significant change on curcumin content, water activity, pH and moisture content of rhizome investigated.

  16. Thermal annealing and UV irradiation effects on structure, morphology, photoluminescence and optical absorption spectra of EDTA-capped ZnS nanoparticles

    NASA Astrophysics Data System (ADS)

    Osman, M. A.; Othman, A. A.; El-Said, Waleed A.; Abd-Elrahim, A. G.; Abu-sehly, A. A.

    2016-02-01

    Monodispersed ZnS nanoparticles (NPs) were prepared by the chemical precipitation method. Thermally induced structural, morphological and optical changes have been investigated using x-ray diffraction, high-resolution transmission electron microscopy, optical absorption, photoluminescence (PL), and Fourier transform infrared and Raman spectroscopy. It was found that D increases with increasing annealing temperature (T a). The onset of the ZnS phase transition from cubic to hexagonal structure takes place at 400 °C, while cubic ZnS transforms into hexagonal ZnO via thermal oxidation in air at 600 °C. It is also noted that increasing T a results in the red shift of the optical band gap (E\\text{g}\\text{opt} ) and the thermal bleaching of exciton absorption. The PL spectrum of as-prepared ZnS nanopowder shows UV emission bands at 363 and 395 nm and blue and green emission at 438 and 515 nm, respectively. With increasing T a up to 500 °C, these bands were quenched and red-shifted. In addition, the UV irradiation effects on colloidal ZnS NPs were investigated. UV irradiation at a dose  <13 J cm-2 leads to a decrease in D, the blue shift of E\\text{g}\\text{opt} and the enhancement of PL intensity. This behavior was explained in terms of surface modification by photopolymerization, the formation of a ZnSO4 passivation layer, as well as the reduction of D by photocorrosion. At a UV irradiation dose  <13 J cm-2 both E\\text{g}\\text{opt} and D did not change and PL intensity was quenched, which were caused by the creation of nonradiative surface states by the photodegradation of the capping agent and photopassivated layer. The mechanism of the PL emission process in ZnS NPs was discussed and an energy band diagram was proposed.

  17. Measurement and calculation of neutron leakage spectra from slab samples of beryllium, gallium and tungsten irradiated with 14.8 MeV neutrons

    NASA Astrophysics Data System (ADS)

    Nie, Y. B.; Ruan, X. C.; Ren, J.; Zhang, S.; Han, R.; Bao, J.; Huang, H. X.; Ding, Y. Y.; Wu, H. C.; Liu, P.; Zhou, Z. Y.

    2017-09-01

    In order to make benchmark validation of the nuclear data for gallium (Ga), tungsten (W) and beryllium (Be) in existing modern evaluated nuclear data files, neutron leakage spectra in the range from 0.8 to 15 MeV from slab samples were measured by time-of-flight technique with a BC501 scintillation detector. The measurements were performed at China Institute of Atomic Energy (CIAE) using a D-T neutron source. The thicknesses of the slabs were 0.5 to 2.5 mean free path for 14.8 MeV neutrons, and the measured angles were chosen to be 60∘ and 120∘. The measured spectra were compared with those calculated by the continuous energy Monte-Carlo transport code MCNP, using the data from the CENDL-3.1, ENDF/B-VII.1 and JENDL-4.0 nuclear data files, the comparison between the experimental and calculated results show that: The results from all three libraries significantly underestimate the cross section in energy range of 10-13 MeV for Ga; For W, the calculated spectra using data from CENDL-3.1 and JENDL-4.0 libraries show larger discrepancies with the measured ones, especially around 8.5-13.5 MeV; and for Be, all the libraries led to underestimation below 3 MeV at 120∘.

  18. Influence of gamma irradiation on hydrophobic room-temperature ionic liquids [BuMeIm]PF6 and [BuMeIm](CF3SO2)2N.

    PubMed

    Berthon, L; Nikitenko, S I; Bisel, I; Berthon, C; Faucon, M; Saucerotte, B; Zorz, N; Moisy, Ph

    2006-06-07

    Stability of neat hydrophobic Room-Temperature Ionic Liquids (RTIL) [BuMeIm]X, where [BuMeIm]+ is 1-butyl-3-methylimidazolium and X- is PF6-, and (CF3SO2)2N-, was studied under gamma radiolysis (137Cs) in an argon atmosphere and in air. It was found that the density, surface tension, and refraction index of RTILs are unchanged even by an absorbed dose of approximately 600 kGy. Studied RTILs exhibit considerable darkening when subjected to gamma irradiation. The light absorbance of ionic liquids increases linearly with the irradiation dose. Water has no influence on radiolytic darkening. A comparative study of [BuMeIm]X and [Bu4N][Tf2N] leads to the conclusion that the formation of colored products is related to gamma radiolysis of the [BuMeIm]+ cation. The radiolytic darkening kinetics of RTILs is influenced by the anions as follows: Cl- < (CF3SO2)2N- < PF6-. Electrospray ionization mass spectrometry and NMR analysis reveal the presence of nonvolatile radiolysis products at concentrations below 1 mol% for an absorbed dose exceeding 1200 kGy. Initial step of BuMeIm+ cation radiolysis is the loss of the Bu* group, the H* atom from the 2 position on the imidazolium ring, and the H* atom from the butyl chain. Radiolysis of ionic liquid anions yields F* and CF3* from PF6- and [Tf2N]-, respectively. Recombinations of these primary products of radiolysis lead to various polymeric and acidic species.

  19. Space weathering of asteroidal surfaces. Influence on the UV-Vis spectra

    NASA Astrophysics Data System (ADS)

    Kaňuchová, Z.; Baratta, G. A.; Garozzo, M.; Strazzulla, G.

    2010-07-01

    Context. The surfaces of airless bodies in the Solar System are continuously altered by the bombardment of micrometeoroids and irradiation by solar wind, flares, and cosmic particles. Major effects of this process - space weathering - are darkening and “reddening” of the spectra of surface materials, as well as a “degrading” of absorption features. Aims: We studied the changes induced by energetic ion irradiation in the ultraviolet-visual-near-infrared (UV-Vis-NIR) (0.2-0.98 μm) reflectance spectra of targets selected to mimic the surfaces of airless bodies in the inner Solar System. Our chosen targets are olivine pellets, pure or covered by an organic polymer (polystyrene), which is transparent before irradiation. Polystyrene is used as a template for organic matter of low volatility that can be present on asteroidal surfaces. Moreover we measured the changes induced by ion irradiation in the absorption coefficient of the polymer. The purpose was to have a tool to better compare laboratory with observed spectra and distinguish between planetary objects with pure silicate surfaces and those whose surface is covered by organic matter exposed to cosmic ion bombardment. Methods: The samples were irradiated in vacuum, at room temperature, with 200 keV protons or 200-400 keV argon ions. Before, during, and after irradiation diffuse reflectance spectra were acquired. Polystyrene films were also deposited on quartz substrates and irradiated while transmittance spectra were recorded. Results: We measured the variations of the absorption coefficient of polystyrene as a function of ion fluence. We showed that after ion irradiation the diffuse reflectance spectra of the samples covered by organics exhibit a much more significant variation than those of pure silicates. The spectra of targets made of olivine plus polystyrene can be fitted by using the measured absorption coefficient of polystyrene. Conclusions: The results obtained for pure olivine extend to the UV the

  20. DOSE AND GAMMA-RAY SPECTRA FROM NEUTRON-INDUCED RADIOACTIVITY IN MEDICAL LINEAR ACCELERATORS FOLLOWING HIGH-ENERGY TOTAL BODY IRRADIATION.

    PubMed

    Keehan, S; Taylor, M L; Smith, R L; Dunn, L; Kron, T; Franich, R D

    2016-12-01

    Production of radioisotopes in medical linear accelerators (linacs) is of concern when the beam energy exceeds the threshold for the photonuclear interaction. Staff and patients may receive a radiation dose as a result of the induced radioactivity in the linac. Gamma-ray spectroscopy was used to identify the isotopes produced following the delivery of 18 MV photon beams from a Varian 21EX and an Elekta Synergy. The prominent radioisotopes produced include (187)W, (63)Zn, (56)Mn, (24)Na and (28)Al in both linac models. The dose rate was measured at the beam exit window (12.6 µSv in the first 10 min) following 18 MV total body irradiation (TBI) beams. For a throughput of 24 TBI patients per year, staff members are estimated to receive an annual dose of up to 750 μSv at the patient location. This can be further reduced to 65 μSv by closing the jaws before re-entering the treatment bunker. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Memory's Room.

    ERIC Educational Resources Information Center

    Carruthers, Mary

    1999-01-01

    Describes the Liberal Arts Studiolo from the Ducal Palace at Guibbio, Italy. Discusses how the room's design and decoration mirrors its educational uses. Notes that the object of education was to provide the young person with a kind of mental library of materials that could be drawn upon quickly. (RS)

  2. Memory's Room.

    ERIC Educational Resources Information Center

    Carruthers, Mary

    1999-01-01

    Describes the Liberal Arts Studiolo from the Ducal Palace at Guibbio, Italy. Discusses how the room's design and decoration mirrors its educational uses. Notes that the object of education was to provide the young person with a kind of mental library of materials that could be drawn upon quickly. (RS)

  3. Positron annihilation Doppler broadening spectroscopy study on Fe-ion irradiated NHS steel

    NASA Astrophysics Data System (ADS)

    Zhu, Huiping; Wang, Zhiguang; Gao, Xing; Cui, Minghuan; Li, Bingsheng; Sun, Jianrong; Yao, Cunfeng; Wei, Kongfang; Shen, Tielong; Pang, Lilong; Zhu, Yabin; Li, Yuanfei; Wang, Ji; Song, Peng; Zhang, Peng; Cao, Xingzhong

    2015-02-01

    In order to study the evolution of irradiation-induced vacancy-type defects at different irradiation fluences and temperatures, a new type of ferritic/martensitic (F/M) steel named NHS (Novel High Silicon) was irradiated by 3.25 MeV Fe-ion at room temperature and 723 K to fluences of 4.3 × 1015 and 1.7 × 1016 ions/cm2. After irradiation, vacancy-type defects were investigated with variable-energy positron beam Doppler broadening spectra. Energetic Fe-ions produced a large number of vacancy-type defects in the NHS steel, but one single main type of vacancy-type defect was observed in both unirradiated and irradiated samples. The concentration of vacancy-type defects decreased with increasing temperature. With the increase of irradiation fluence, the concentration of vacancy-type defects increased in the sample irradiated at RT, whereas for the sample irradiated at 723 K, it decreased. The enhanced recombination between vacancies and excess interstitial Fe atoms from deeper layers, and high diffusion rate of self-interstitial atoms further improved by diffusion via grain boundary and dislocations at high temperature, are thought to be the main reasons for the reversed trend of vacancy-type defects between the samples irradiated at RT and 723 K.

  4. Electron irradiation of transparent and ceramics window materials

    NASA Astrophysics Data System (ADS)

    Regan, Thomas M.; Gilde, Gary A.; Goodrich, Steven M.

    2001-09-01

    The use of energetic electrons to modify the optical and mechanical properties of several window materials was examined. The materials were exposed to fields of high-energy electrons (5 MeV at a dose of 1,000 MRad). In this paper, we will report on the electron irradiation effects on the following materials: alumina, ALON, ZnSe and ZnS. Alumina irradiated under these conditions revealed little if any changes in flexure strength at room temperature. Irradiation changes in ALON hardness were measured. The hardness fracture toughness of electron beam irradiated ZnS and ZnSe was examined by both indentation and known flaw methods. Toughness measured by both methods were then compared and contrasted to ascertain the effects induced by the irradiation. The electron irradiation produced changes in the fracture toughness of both the ZnS and the ZnSe. The optical properties of the ZnSe and ZnS were measured by FTIR indicated minor changes in the absorption spectra.

  5. EPR studies of gamma-irradiated taurine single crystals

    NASA Astrophysics Data System (ADS)

    Bulut, A.; Karabulut, B.; Tapramaz, R.; Köksal, F.

    2000-04-01

    An EPR study of gamma-irradiated taurine [C 2H 7NO 3S] single crystal was carried out at room temperature. The EPR spectra were recorded in the three at mutually perpendicular planes. There are two magnetically distinct sites in monoclinic lattice. The principle values of g and hyperfine constants for both sites were calculated. The results have indicated the presence of 32ṠO -2 and 33ṠO -2 radicals. The hyperfine values of 33ṠO -2 radical were used to obtain O-S-O bond angle for both sites.

  6. Investigation of irradiated 1H-Benzo[b]pyrrole by ESR, thermal methods and learning algorithm

    NASA Astrophysics Data System (ADS)

    Algul, Gulay; Ceylan, Yusuf; Usta, Keziban; Yumurtaci Aydogmus, Hacer; Usta, Ayhan; Asik, Biray

    2016-05-01

    1H-Benzo[b]pyrrole samples were irradiated in the air with gamma source at 0.969 kGy per hour at room temperature for 24, 48 and 72 h. After irradiation, electron spin resonance, thermogravimetry analysis (TGA) and differential thermal analysis (DTA) measurements were immediately carried out on the irradiated and unirradiated samples. The ESR measurements were performed between 320 and 400 K. ESR spectra were recorded from the samples irradiated for 48 and 72 h. The obtained spectra were observed to be dependent on temperature. Two radical-type centres were detected on the sample. Detected radiation-induced radicals were attributed to R-+•NH and R=•CC2H2. The g-values and hyperfine constants were calculated by means of the experimental spectra. It was also determined from TGA spectrum that both the unirradiated and irradiated samples were decomposed at one step with the rising temperature. Moreover, a theoretical study was presented. Success of the machine learning methods was tested. It was found that bagging techniques, which are widely used in the machine learning literature, could optimise prediction accuracy noticeably.

  7. Basement utility room (room 24; air handling room), near the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Basement utility room (room 24; air handling room), near the west end of the combat operations center, looking southwest towards fan system one, air ducts, and walk-in filter rooms. The exterior equipment well is visible at the left - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  8. Synthesis and magnetic characterization of magnetite obtained by monowavelength visible light irradiation

    SciTech Connect

    Lin, Yulong; Wei, Yu; Sun, Yuhan; Wang, Jing

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Magnetite was synthesized under monowavelength LED irradiation at room temperature. Black-Right-Pointing-Pointer Different wavelength irradiations led to distinctive characteristics of magnetite. Black-Right-Pointing-Pointer Particle sizes of magnetite were controlled by different irradiation wavelengths. Black-Right-Pointing-Pointer Wavelength affects the magnetic characteristics of magnetite. -- Abstract: Magnetite (Fe{sub 3}O{sub 4}) nanoparticles were controllably synthesized by aerial oxidation Fe{sup II}EDTA solution under different monowavelength light-emitting diode (LED) lamps irradiation at room temperature. The results of the X-ray diffraction (XRD) spectra show the formation of magnetite nanoparticle further confirmed by Fourier transform infrared spectroscope (FTIR) and the difference in crystallinity of as-prepared samples. Fe{sub 3}O{sub 4} particles are nearly spherical in shape based on transmission electron microscopy (TEM). Average crystallite sizes of magnetite can be controlled by different irradiation light wavelengths from XRD and TEM: 50.1, 41.2, and 20.3 nm for red, green, and blue light irradiation, respectively. The magnetic properties of Fe{sub 3}O{sub 4} samples were investigated. Saturation magnetization values of magnetic nanoparticles were 70.1 (sample M-625), 65.3 (sample M-525), and 58.2 (sample M-460) emu/g, respectively.

  9. High temperature effects on irradiation damage of Ti2AlC

    NASA Astrophysics Data System (ADS)

    Liu, Shaoshuai; Wang, Chenxu; Yang, Tengfei; Fang, Yuan; Huang, Qing; Wang, Yugang

    2017-09-01

    As one of the MAX phases, Ti2AlC combines attractive properties of both ceramics and metals, and has been suggested for potential nuclear reactor applications due to its excellent resistance to irradiation. This work is aimed at investigating the high temperature effects on evolution of irradiation damage in the MAX phase Ti2AlC. Ti2AlC was irradiated with 1.1 MeV C4+ ions at 298 K and 873 K with fluences ranging from 2 × 1015 cm-2 to 6 × 1016 cm-2. Scanning electron microscopy (SEM), Raman spectra, grazing incidence X-ray diffraction (GIXRD), transmission electron microscopy (TEM), and nanoindentation were used to characterize the evolution of microstructures and mechanical properties at both temperatures. Significant crackings along grain boundaries were observed in 298 K, which were not observed in the samples irradiated at 837 K. No amorphization was found in the GIXRD analyses and TEM characterization, and some fcc phases were formed during high dose irradiation at 298 K. Raman spectra show that all the vibration modes of Ti2AlC decreased severely in room temperature irradiation, but they nearly remained unchanged in high temperature irradiation at the dose of 2 × 1015 cm-2. Nanoindentation shows significant hardening for Ti2AlC irradiated at high temperature, suggesting the presence of irradiation-induced defects. The current study reveals that the irradiation tolerance of Ti2AlC is significantly improved with increasing temperature, demonstrating the great potential of Ti2AlC for using in advanced nuclear reactors.

  10. Models of Solar Irradiance Variability

    NASA Astrophysics Data System (ADS)

    Solanki, Sami K.

    2015-08-01

    Models of solar irradiance variability have an important role to play due to the relatively short (although steadily increasing) length of measured irradiance time series. Advanced models also allow identifying the source of solar irradiance variations and give insight into the variation of irradiance as a function of wavelength. The first generation of models of solar irradiance were proxy-based, i.e. purely empirical. These were followed by models that combine spectra computed from semi-empirical model atmospheres, with a measure of solar activity variations. In future, models will build increasingly on 3D MHD simulations instead of 1D model atmospheres to compute the spectra. On longer timescales models are generally simpler, although there too considerable progress has been made, with irradiance reconstructions now available for multiple millennia, albeit with lower resolution and accuracy than at shorter timescales.

  11. Optical alteration of complex organics induced by ion irradiation:. 1. Laboratory experiments suggest unusual space weathering trend

    NASA Astrophysics Data System (ADS)

    Moroz, Lyuba; Baratta, Giuseppe; Strazzulla, Giovanni; Starukhina, Larissa; Dotto, Elisabetta; Barucci, Maria Antonietta; Arnold, Gabriele; Distefano, Elisa

    2004-07-01

    Most ion irradiation experiments relevant to primitive outer Solar System objects have been performed on ice and silicate targets. Here we present the first ion irradiation experiments performed on natural complex hydrocarbons (asphaltite and kerite). These materials are very dark in the visible and have red-sloped spectra in the visible and near-infrared. They may be comparable in composition and structure to refractory organic solids on the surfaces of primitive outer Solar System objects. We irradiated the samples with 15-400 keV H +, N +, Ar ++, and He + ions and measured their reflectance spectra in the range of 0.3-2.5 μm before ion implantation and after each irradiation step. The results show that irradiation-induced carbonization gradually neutralizes the spectral slopes of these red organic solids. This implies a similar space weathering trend for the surfaces of airless bodies optically dominated by spectrally red organic components. The reduction of spectral slope was observed in all experiments. Irradiation with 30 keV protons, which transfers energy to the target mostly via electronic (inelastic) collisions, showed lower efficiency than the heavier ions. We found that spectral alteration in our experiments increased with increasing contribution of nuclear versus electronic energy loss. This implies that nuclear (elastic) energy deposition plays an important role in changing the optical properties of irradiated refractory complex hydrocarbon materials. Finally, our results indicated that temperature variations from 40 K to room temperature did not influence the spectral properties of these complex hydrocarbon solids.

  12. Tolerability and toxicity of prophylactic cranial irradiation in patients with non-small cell lung cancer – Results of a phase II study (with estimation of hematological toxicity, pituitary function and magnetic resonance spectra changes)

    PubMed Central

    Marzena, Gawkowska-Suwińska; Sławomir, Blamek; Alicja, Heyda; Łukasz, Boguszewicz; Anna, Cichoń; Łukasz, Zarudzki; Elżbieta, Nowicka; Katarzyna, Behrendt; Beata, Smolska-Ciszewska; Grzegorz, Plewicki; Aleksander, Zajusz; Rafał, Tarnawski

    2014-01-01

    Aim To evaluate the tolerability and toxicity of PCI in patients with NSCLC. Background Prophylactic cranial irradiation (PCI) is a standard treatment for patients with small cell lung cancer. There are data showing a decreasing ratio of brain metastases after PCI for non-small cell lung cancer (NSCLC-non small cell lung cancer) patients but, so far, there is no evidence for increasing overall survival. The main concern in this setting is the tolerance and toxicity of the treatment. Materials and methods From 1999 to 2007, 50 patients with NSCLC treated with radical intent underwent PCI (30 Gy in 15 fractions). Mean follow-up was 2.8 years. The tolerability and hematological toxicity were evaluated in all patients, a part of participants had done neuropsychological tests, magnetic resonance imaging with 1H nuclear magnetic resonance spectra, and estimation of pituitary function. Results During follow-up, 20 patients developed distant metastases, 4-brain metastases. Fourteen (30%) patients had acute side effects: (headache, nausea, erythema of the skin). The symptoms did not require treatment breaks. Six patients complained of late side effects (vertigo, nausea, anxiety, lower extremity weakness, deterioration of hearing and olfactory hyperesthesia). Hematological complications were not observed. Testosterone levels tended to decrease (p = 0.062). Visual-motor function deteriorated after treatment (p < 0.059). Performance IQ decreased (p < 0.025) and the difference between performance IQ and verbal IQ increased (p < 0.011). Degenerative periventricular vascular changes were observed in two patients. Analysis of the spectroscopic data showed metabolic but reversible alterations after PCI. Conclusion PCI in the current series was well tolerated and associated with a relatively low toxicity. PMID:25337408

  13. ESR study of some gamma irradiated amino acids and condensed 1,4-dihydropyridines

    NASA Astrophysics Data System (ADS)

    Aydın, Murat; Şimşek, Rahime; Gündüz, Miyase Gözde; Şafak, Cihat; Osmanoğlu, Y. Emre

    2013-03-01

    L-alanine methyl ester hydrochloride, 2-aminoisobutyric acid and some condensed 1,4-dihydropyridine derivatives (Compounds R1-R4) were gamma irradiated, the induced free radicals was investigated at room temperature by electron spin resonance techniques. The observed paramagnetic species of amino acids compounds were attributed to the CH3ĊHCOOCH3 and (CH3)2ĊCOOH radicals, respectively. The observed spectra of the 1,4-dihydropyridine derivatives interpreted in terms of some type of amine radical fragments. The spectra were computer simulated and the g values of the radicals and the hyperfine structure constants of the unpaired electron with nearby protons and 14N nucleus were determined. In this study, the observed paramagnetic species were found to be stable at room temperature more than 2 months.

  14. Inequality spectra

    NASA Astrophysics Data System (ADS)

    Eliazar, Iddo

    2017-03-01

    Inequality indices are widely applied in economics and in the social sciences as quantitative measures of the socioeconomic inequality of human societies. The application of inequality indices extends to size-distributions at large, where these indices can be used as general gauges of statistical heterogeneity. Moreover, as inequality indices are plentiful, arrays of such indices facilitate high-detail quantification of statistical heterogeneity. In this paper we elevate from arrays of inequality indices to inequality spectra: continuums of inequality indices that are parameterized by a single control parameter. We present a general methodology of constructing Lorenz-based inequality spectra, apply the general methodology to establish four sets of inequality spectra, investigate the properties of these sets, and show how these sets generalize known inequality gauges such as: the Gini index, the extended Gini index, the Rényi index, and hill curves.

  15. Identification of irradiated sage tea ( Salvia officinalis L.) by ESR spectroscopy

    NASA Astrophysics Data System (ADS)

    Tepe Çam, Semra; Engin, Birol

    2010-04-01

    The use of electron spin resonance (ESR) spectroscopy to accurately distinguish irradiated from unirradiated sage tea was examined. Before irradiation, sage tea samples exhibit one asymmetric singlet ESR signal centered at g=2.0037. Besides this central signal, two weak satellite signals situated about 3 mT left and right to it in radiation-induced spectra. Irradiation with increasing doses caused a significant increase in radiation-induced ESR signal intensity at g=2.0265 (the left satellite signal) and this increase was found to be explained by a polynomial varying function. The stability of that radiation-induced ESR signal at room temperature was studied over a storage period of 9 months. Also, the kinetic of signal at g=2.0265 was studied in detail over a temperature range 313-353 K by annealing samples at different temperatures for various times.

  16. An infrared study of pure and ion irradiated frozen formamide

    NASA Astrophysics Data System (ADS)

    Brucato, J. R.; Baratta, G. A.; Strazzulla, G.

    2006-08-01

    Context.The chemical evolution of formamide (HCONH2), a molecule of astrobiological interest that has been tentatively identified in interstellar ices and in cometary coma, has been studied in laboratory under simulated astrophysical conditions such as ion irradiation at low temperature.Aims.To evaluate the abundances of formamide observed in space or in laboratory, the integrated absorbances for all the principal IR features of frozen amorphous pure formamide deposited at 20 K were measured. Further evidence that energetic processing of ices occurring in space is extremely relevant both to astrochemistry and to astrobiology has been found, showing that new molecular species are synthesized by ion irradiation at a low temperature.Methods.Pure formamide were deposited at 20 K and IR transmission spectra measured for different ice thicknesses. The ice thickness was derived by looking at the interference pattern (intensity versus time) of a He-Ne laser beam reflected at an angle of 45 deg by the vacuum-film and film-substrate interfaces. Samples of formamide ice were irradiated with 200 keV H+ ions and IR spectra recorded at different ion fluences.Results.New molecules were synthesized among which are CO, CO2, N2O, isocyanic acid (HNCO), and ammonium cyanate (NH4^+OCN^-). Some of these species remain stable after warming up to room temperature.

  17. Noise control considerations for patient rooms

    NASA Astrophysics Data System (ADS)

    Davenny, Benjamin

    2005-09-01

    The patient room envelope is a path between outside noise sources and the patient receiver. Within the patient room there are several sources including televisions, clinical monitor alarms, medical pumps, etc. Noise control in patient rooms relies on a combination of the sound transmission loss of the patient room envelope and the level of background sound at the patient's head. Guidelines published by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE), American Institute of Architects (AIA), and the U.S. Department of Defense for background noise and sound transmission loss in patient rooms will be discussed. Appropriate levels, spectra, and temporal characteristics of background sound at the patient head location may be helpful in raising the threshold of annoying sounds. Various means of personal hearing protection for patients will be discussed. Sound-pressure levels in patient rooms reported in previous literature will also be discussed.

  18. ESR and TL investigations on gamma irradiated linden (Tilia vulgaris).

    PubMed

    Paksu, Ufuk; Aydaş, Canan; Yüce, Ülkü Rabia; Aydın, Talat; Polat, Mustafa; Engin, Birol

    2013-05-01

    Electron spin resonance (ESR) and thermoluminescence (TL) signals induced by gamma irradiation in linden (Tilia vulgaris) were studied for detection and dosimetric purposes. Before irradiation, linden leaf samples exhibit one singlet ESR signal centred at g = 2.0088. Besides this central signal, in spectra of irradiated linden samples, two weak satellite signals situated about 3 mT left (g = 2.0267) and right (g = 1.9883) were observed. Dose-response curves for the left satellite signal and the central single signal were constructed, and it was found that both of these curves can be described best by the combination of two exponential saturation functions. Variable temperature and fading studies at room temperature showed that the radiation-induced radicals in linden leaf samples are very sensitive to temperature. The stabilities of the left satellite (g = 2.0267) and the central single (g = 2.0088) signal at room temperature over a storage period of 126 days turned out to be best described by a sum of two first-order decay functions. The kinetic features of the left satellite signal were studied over the temperature range of 313-373 K. The results indicate that the isothermal decay curves of the left satellite ESR signal also proved to be best fitted by the combination of two first-order decay functions. Fading and annealing studies suggested the existence of two different radiation-induced free radical species. At the same time, Arrhenius plots evidenced two different kinetic regimes with two different activation energies. TL investigation of polyminerals from the linden samples allowed to discriminate clearly between irradiated and unirradiated samples even 75 days after irradiation.

  19. Comparison of luminescence property of gamma-ray irradiated Tb(3+) -doped and Ce(3)(+) co-doped potassium halide single crystals.

    PubMed

    Bangaru, S; Ravi, D; Saradha, K

    2017-05-01

    Single crystals of KCl and KBr singly and doubly doped with Tb(3)(+) and Ce(3)(+) , respectively, were successfully grown using the Bridgeman technique. This work reports the comparative luminescence behavior and optical absorption characterization of non-irradiated and γ-ray-irradiated single crystals of these materials. The existing defect and the defect created by γ-ray irradiation were monitored by optical absorption spectra. The excitation and emission spectra of these materials were measured at room temperature with a spectrofluorometer and the pertaining results were compared. The F-band comparison was made when bleached with F-light for 2 mins. The trap-level changes in KCl and KBr when it is singly and doubly doped enabled us to draw conclusions on the nature of the defect and on the recombination processes involved. Copyright © 2016 John Wiley & Sons, Ltd.

  20. FTIR study of silicon carbide amorphization by heavy ion irradiations

    NASA Astrophysics Data System (ADS)

    Costantini, Jean-Marc; Miro, Sandrine; Pluchery, Olivier

    2017-03-01

    We have measured at room temperature (RT) the Fourier-transform infra-red (FTIR) absorption spectra of ion-irradiated thin epitaxial films of cubic silicon carbide (3C-SiC) with 1.1 µm thickness on a 500 µm thick (1 0 0) silicon wafer substrate. Irradiations were carried out at RT with 2.3 MeV 28Si+ ions and 3.0 MeV 84Kr+ ions for various fluences in order to induce amorphization of the SiC film. Ion projected ranges were adjusted to be slightly larger than the film thickness so that the whole SiC layers were homogeneously damaged. FTIR spectra of virgin and irradiated samples were recorded for various incidence angles from normal incidence to Brewster’s angle. We show that the amorphization process in ion-irradiated 3C-SiC films can be monitored non-destructively by FTIR absorption spectroscopy without any major interference of the substrate. The compared evolutions of TO and LO peaks upon ion irradiation yield valuable information on the damage process. Complementary test experiments were also performed on virgin silicon nitride (Si3N4) self-standing films for similar conditions. Asymmetrical shapes were found for TO peaks of SiC, whereas Gaussian profiles are found for LO peaks. Skewed Gaussian profiles, with a standard deviation depending on wave number, were used to fit asymmetrical peaks for both materials. A new methodology for following the amorphization process is proposed on the basis of the evolution of fitted IR absorption peak parameters with ion fluence. Results are discussed with respect to Rutherford backscattering spectrometry channeling and Raman spectroscopy analysis.

  1. Nitrogen oxides and carbon chain oxides formed after ion irradiation of CO:N2 ice mixtures

    NASA Astrophysics Data System (ADS)

    Sicilia, D.; Ioppolo, S.; Vindigni, T.; Baratta, G. A.; Palumbo, M. E.

    2012-07-01

    Context. High CO depletion as well as depletion of N-bearing species is observed in dense pre-stellar cores. It is generally accepted that depleted species freeze out onto dust grains to form icy mantles and that these ices suffer energetic processing due to cosmic ion irradiation and ion-induced UV photons. Aims: The aim of this work is to study the chemical and structural effects induced by ion irradiation on different CO:N2 mixtures at low temperature (16 K) to simulate the effects of cosmic ion irradiation of icy mantles. Methods: Different CO:N2 mixtures and pure CO and pure N2 were irradiated with 200 keV H+ at 16 K. Infrared transmittance spectra of the samples were obtained in situ before and after irradiation. The samples were warmed up and spectra were taken at different temperatures. The residues left over on the substrate at room temperature were analysed ex situ by micro Raman spectroscopy. Results: Several new absorption features are present in the infrared spectra after irradiation, indicating that new species are formed. The most abundant are nitrogen oxides (such as NO, NO2 and N2O), carbon chain oxides (such as C2O, C3O and C3O2), carbon chains (such as C3 and C6), O3 and N3. A refractory residue is also formed after ion irradiation and is clearly detected by Raman spectroscopy. Conclusions: We suggest that carbon chains and nitrogen oxides observed in the gas phase towards star-forming regions are formed in the solid phase after cosmic ion irradiation of icy grain mantles and are released into the gas phase after desorption of grain mantles. We expect that the Atacama Large Millimeter/submillimeter Array (ALMA), thanks to its high sensitivity and resolution, will increase the number of nitrogen oxides and carbon chain oxides detected towards star-forming regions.

  2. KENNEDY SPACE CENTER, FLA. - Workers in NASA Spacecraft Hangar AE begin the next phase of processing of the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

    NASA Image and Video Library

    2003-05-02

    KENNEDY SPACE CENTER, FLA. - Workers in NASA Spacecraft Hangar AE begin the next phase of processing of the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

  3. KENNEDY SPACE CENTER, FLA. - Workers in NASA Spacecraft Hangar AE position the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad, for further processing. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

    NASA Image and Video Library

    2003-05-02

    KENNEDY SPACE CENTER, FLA. - Workers in NASA Spacecraft Hangar AE position the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad, for further processing. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

  4. KENNEDY SPACE CENTER, FLA. - In the NASA Spacecraft Hangar AE, the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad, is uncovered by workers following its arrival. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

    NASA Image and Video Library

    2003-05-02

    KENNEDY SPACE CENTER, FLA. - In the NASA Spacecraft Hangar AE, the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad, is uncovered by workers following its arrival. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

  5. KENNEDY SPACE CENTER, FLA. - Workers in NASA Spacecraft Hangar AE remove the protective cover from around the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

    NASA Image and Video Library

    2003-05-02

    KENNEDY SPACE CENTER, FLA. - Workers in NASA Spacecraft Hangar AE remove the protective cover from around the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

  6. KENNEDY SPACE CENTER, FLA. - Workers in NASA Spacecraft Hangar AE check the placement of the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad for further processing. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

    NASA Image and Video Library

    2003-05-02

    KENNEDY SPACE CENTER, FLA. - Workers in NASA Spacecraft Hangar AE check the placement of the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad for further processing. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

  7. KENNEDY SPACE CENTER, FLA. - Workers in NASA Spacecraft Hangar AE prepare to remove the canister from around the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

    NASA Image and Video Library

    2003-05-02

    KENNEDY SPACE CENTER, FLA. - Workers in NASA Spacecraft Hangar AE prepare to remove the canister from around the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

  8. KENNEDY SPACE CENTER, FLA. - Workers in NASA Spacecraft Hangar AE lift the protective cover from around the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

    NASA Image and Video Library

    2003-05-02

    KENNEDY SPACE CENTER, FLA. - Workers in NASA Spacecraft Hangar AE lift the protective cover from around the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

  9. KENNEDY SPACE CENTER, FLA. - Workers in NASA Spacecraft Hangar AE remove sections of the transportation canister from around the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

    NASA Image and Video Library

    2003-05-02

    KENNEDY SPACE CENTER, FLA. - Workers in NASA Spacecraft Hangar AE remove sections of the transportation canister from around the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

  10. KENNEDY SPACE CENTER, FLA. - Workers in NASA Spacecraft Hangar AE remove a portion of a transportation canister from around the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

    NASA Image and Video Library

    2003-05-02

    KENNEDY SPACE CENTER, FLA. - Workers in NASA Spacecraft Hangar AE remove a portion of a transportation canister from around the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

  11. KENNEDY SPACE CENTER, FLA. - The Space Infrared Telescope Facility (SIRTF) has been returned to NASA Spacecraft Hangar AE from the launch pad. It will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

    NASA Image and Video Library

    2003-05-02

    KENNEDY SPACE CENTER, FLA. - The Space Infrared Telescope Facility (SIRTF) has been returned to NASA Spacecraft Hangar AE from the launch pad. It will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

  12. KENNEDY SPACE CENTER, FLA. - Workers in NASA Spacecraft Hangar AE erect a ladder to reach the top of the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

    NASA Image and Video Library

    2003-05-02

    KENNEDY SPACE CENTER, FLA. - Workers in NASA Spacecraft Hangar AE erect a ladder to reach the top of the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

  13. Solid organic residues produced by irradiation of hydrocarbon-containing H2O and H2O/NH3 ices - Infrared spectroscopy and astronomical implications

    NASA Technical Reports Server (NTRS)

    Khare, B. N.; Thompson, W. R.; Murray, B. G. J. P. T.; Chyba, C. F.; Sagan, C.

    1989-01-01

    Plasma-discharge irradiations were conducted for the methane clathrate expected in outer solar system satellites and cometary nuclei; also irradiated were ices prepared from other combinations of H2O with CH4, C2H6, or C2H2. Upon evaporation of the yellowish-to-tan irradiated ices, it is found that a colored solid film adheres to the walls of the reaction vessel at room temperature. These organic films are found to exhibit IR band identifiable with alkane, aldehide, alcohol, and perhaps alkene, as well as substituted aromatic functional groups. These spectra are compared with previous studies of UV- or photon-irradiated nonclathrated hydrocarbon-containing ices.

  14. Solid organic residues produced by irradiation of hydrocarbon-containing H2O and H2O/NH3 ices - Infrared spectroscopy and astronomical implications

    NASA Astrophysics Data System (ADS)

    Khare, B. N.; Thompson, W. R.; Murray, B. G. J. P. T.; Chyba, C. F.; Sagan, C.; Arakawa, E. T.

    1989-06-01

    Plasma-discharge irradiations were conducted for the methane clathrate expected in outer solar system satellites and cometary nuclei; also irradiated were ices prepared from other combinations of H2O with CH4, C2H6, or C2H2. Upon evaporation of the yellowish-to-tan irradiated ices, it is found that a colored solid film adheres to the walls of the reaction vessel at room temperature. These organic films are found to exhibit IR band identifiable with alkane, aldehide, alcohol, and perhaps alkene, as well as substituted aromatic functional groups. These spectra are compared with previous studies of UV- or photon-irradiated nonclathrated hydrocarbon-containing ices.

  15. Locker Room Talk.

    ERIC Educational Resources Information Center

    Fickes, Michael

    1999-01-01

    Examines the trends in college and university sports and recreation center locker rooms as envisioned by a specialist. Features of the modern locker room and the different levels of locker room design are explained. Final comments discuss whether college and university facility managers are inclined to move to high-end locker rooms. (GR)

  16. Identification and dosimetric features of γ-irradiated cefadroxil by electron spin resonance

    NASA Astrophysics Data System (ADS)

    Aydaş, Canan; Polat, Mustafa; Korkmaz, Mustafa

    2008-01-01

    In the present work, electron spin resonance (ESR) identification of γ-irradiated cefadroxil monohydrate (CM), duricef capsule (DC) and duricef suspension (DS) and their potential use as normal and/or accidental dosimetric materials were investigated in the dose range of 1-25 kGy. Although unirradiated samples did not exhibit any ESR signals, irradiated samples were observed to present ESR spectra with many resonance lines originating from radiation induced radical or radicals. Dose-response curves associated with the resonance peak heights of CM ( I1, I2) and DS ( I3, I4, I5, I6) were found to follow linear and power functions of applied radiation dose, respectively. Simulation calculations were performed to determine the structure and spectral parameters of the radiation-induced radicalic species involved in the formation of experimental ESR spectrum of CM using, as input, the room temperature signal intensity data obtained for a sample irradiated at dose of 10 kGy. Kinetic behaviors and activation energies of the radicalic species were also calculated using the data obtained from annealing studies performed at five different temperatures. The presence of detectable signal intensities even after a storage period of 100 days was considered as providing an opportunity in the discrimination of irradiated CM and DS from unirradiated ones. Basing on room temperature signal intensity decay and dose-response data, it was concluded that CM and DS present the features of a good dosimetric material.

  17. Influence of highly-charged 209Bi33+ irradiation on structure and optoelectric characteristics of GaN epilayer

    NASA Astrophysics Data System (ADS)

    Zhang, L. Q.; Zhang, C. H.; Xu, C. L.; Li, J. J.; Yang, Y. T.; Ma, Y. Z.; Li, J. Y.; Liu, H. P.; Ding, Z. N.; Yan, T. X.; Song, Y.

    2017-09-01

    The microstructure and optoelectric properties of GaN epilayer irradiated by highly-charged 209Bi33+ to different fluences are investigated by means of atomic force microscopy, X-ray photoelectron spectroscopy, Raman scattering spectroscopy and photoluminescence spectroscopy. After Bi33+ irradiation, AFM observation shows the irradiated GaN surface is a swelling and swelling rate nonlinearly increases with increasing ions fluence. XPS analysis reveals the relative content of Ga-N bond reduces and Ga-O, Ga-Ga bonds have been produced as the fluence increases. Raman scattering spectra display the thickness of surface depletion layer increases, free carrier concentration and its mobility decrease generally with an increase in ions fluence. Furthermore, the length of Ga-N bond shortens and lattices experience compressive stress with increasing ions fluence are observed from Raman spectra. Room temperature PL spectra reflect the intensity of yellow luminescence (YL) emission increases and its peak has a blueshift after 1.061 × 1012 Bi33+/cm2 irradiation. Moreover, as the temperature rises, the thermal quenching of YL occurs and its peak position first exhibits a blueshift and then a redshift. Results may be served as a useful reference for HCI to be used in semiconductor fields.

  18. Plasma deposition of amorphous silicon carbide thin films irradiated with neutrons

    NASA Astrophysics Data System (ADS)

    Huran, J.; Bohacek, P.; Kucera, M.; Kleinova, A.; Sasinkova, V.; IEE SAS, Bratislava, Slovakia Team; Polymer Institute, SAS, Bratislava, Slovakia Team; Institute of Chemistry, SAS, Bratislava, Slovakia Team

    2015-09-01

    Amorphous silicon carbide and N-doped silicon carbide thin films were deposited on P-type Si(100) wafer by plasma enhanced chemical vapor deposition (PECVD) technology using silane, methane, ammonium and argon gases. The concentration of elements in the films was determined by RBS and ERDA method. Chemical compositions were analyzed by FTIR spectroscopy. Photoluminescence properties were studied by photoluminescence spectroscopy (PL). Irradiation of samples with various neutron fluencies was performed at room temperature. The films contain silicon, carbon, hydrogen, nitrogen and small amount of oxygen. From the IR spectra, the films contained Si-C, Si-H, C-H, Si-N, N-H and Si-O bonds. No significance effect on the IR spectra after neutron irradiation was observed. PL spectroscopy results of films showed decreasing PL intensity after neutron irradiation and PL intensity decreased with increased neutron fluencies. The measured current of the prepared structures increased after irradiation with neutrons and rise up with neutron fluencies.

  19. 10 CFR 36.67 - Entering and leaving the radiation room.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Entering and leaving the radiation room. 36.67 Section 36.67 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR IRRADIATORS Operation of Irradiators § 36.67 Entering and leaving the radiation room. (a) Upon first entering the...

  20. 10 CFR 36.67 - Entering and leaving the radiation room.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Entering and leaving the radiation room. 36.67 Section 36.67 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR IRRADIATORS Operation of Irradiators § 36.67 Entering and leaving the radiation room. (a) Upon first entering the...

  1. 10 CFR 36.67 - Entering and leaving the radiation room.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Entering and leaving the radiation room. 36.67 Section 36.67 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR IRRADIATORS Operation of Irradiators § 36.67 Entering and leaving the radiation room. (a) Upon first entering the...

  2. 10 CFR 36.67 - Entering and leaving the radiation room.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Entering and leaving the radiation room. 36.67 Section 36.67 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR IRRADIATORS Operation of Irradiators § 36.67 Entering and leaving the radiation room. (a) Upon first entering the...

  3. 10 CFR 36.67 - Entering and leaving the radiation room.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Entering and leaving the radiation room. 36.67 Section 36.67 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR IRRADIATORS Operation of Irradiators § 36.67 Entering and leaving the radiation room. (a) Upon first entering the...

  4. Improving operating room safety

    PubMed Central

    2009-01-01

    Despite the introduction of the Universal Protocol, patient safety in surgery remains a daily challenge in the operating room. This present study describes one community health system's efforts to improve operating room safety through human factors training and ultimately the development of a surgical checklist. Using a combination of formal training, local studies documenting operating room safety issues and peer to peer mentoring we were able to substantially change the culture of our operating room. Our efforts have prepared us for successfully implementing a standardized checklist to improve operating room safety throughout our entire system. Based on these findings we recommend a multimodal approach to improving operating room safety. PMID:19930577

  5. Vibrational spectroscopy study of Ar+-ion irradiated Si-rich oxide films grown by plasma-enhanced chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Mariotto, G.; Das, G.; Quaranta, A.; Della Mea, G.; Corni, F.; Tonini, R.

    2005-06-01

    SiOx thin films with different stoichiometry degree were obtained by plasma-enhanced chemical vapor deposition on crystalline silicon substrates from SiH4 and N2O gas mixtures. Two twin sets of samples were irradiated by 380 keV Ar+ ions at a fluence of 5×1016ions/cm2 at room temperature and at 500 °C, respectively, and then annealed in vacuum at different temperatures, between 500 and 1100 °C. A set of unirradiated samples has been annealed in the same conditions in order to discriminate the contribution of ion irradiation and of thermal treatments to the changes of the film microstructure. The structural modification of the oxide network and the growth of Si nanoclusters have been studied by vibrational spectroscopy techniques. Fourier transform infrared absorption spectra evidenced that ion irradiation induces a hydrogen loss of about 50%, and that postirradiation thermal treatments lead to the recovery of the irradiation defects and to the out diffusion of the residual hydrogen. After heating at 800 °C, irradiated and unirradiated samples exhibit substantially the same structure from the point of view of infrared-absorption spectra. In the meanwhile, the Si-O-Si stretching peak blue shifts, but never reaches the wavenumber value of pure silica owing to the presence of nitrogen into the network. Raman spectra of as-irradiated films reveal the presence of an amorphous silicon phase within the damaged layer of the oxide matrix. Raman spectra of irradiated samples undergoing thermal treatments at high temperature indicate a rearrangement of the film microstructure with the progressive clustering of the amorphous silicon phase. However, no clear spectroscopic evidence is gained about the crystallization of silicon nanoclusters, even after annealing at the highest temperature. In fact, the Raman scattering from silicon nanocrystals is partially hidden by the Raman peak of the c-Si substrate.

  6. Design of YCF-1 mobile γ irradiator

    NASA Astrophysics Data System (ADS)

    Hehu, Zhang; Chuanzhen, Wang

    1993-07-01

    YCF-1 Mobile irradiator is designed by BINE of China. It has been put into running in YanJi city of Jilin province. It is able to be moved to border and distance places and area lumped and spreading out of agricultural products to service. It can play a important role in demonstration and extending irradiation technology in food irradiation, disinfestation, sterilization and quarantine, etc. This paper describes the features and design considerations of mobile irradiator. This irradiator adopted Cesium-137 source. The design capacity of loading source is 9.25PBq (250kCi), A half-time of Cs- 137 is 30.2 years long, exchanging source is not needed utilization rate of energy is higher, and the shielding is thinner, The Weight is lighter, The dose rate on the surface of it is 0.0025mSv/h in accordance with national standard. The internal size of irradiation room is 1800×1800×900mm (L×W×H), The sheilding of irradiation room is a steel shell filled with lead. The thickness of lead is 18cm. The irradiator is installed on a special flat truck. The size of the truck is 7000×3400×4200mm (L×W×H). The weight of irradiator is more than 80 150kw. The main components and parts of irradiator are: source, source racks and hoist, irradiation chamber, storage source chamber, the product's transport system, dose monitoring system, ventilation system and safety interlock system, etc.

  7. Self-Irradiation Effects on 99Mo Reagents and Products

    SciTech Connect

    Carson, S.D.; Garcia, M.J.; McDonald, M.J.; Simpson, R.L.; Tallant, D.R.

    1998-10-07

    produced in 1996 and shipped to pharmaceutical houses for evaluation of compatibility with oxime solution used to precipitate `?vfo as the oxime complex is both air and light-sensitive, and containing a black precipitate that forms during shipment, presumably as a result of self- irradiation. Addition of sodium hypochlorite to the product solution prior to shipment prevents precipitate formation, indicating the precipitate is a reduced form of `%lo. to remove any precipitate. Duplicate aliquots of the filtered samples were titrated to a phenolphthalein irradiation and afler standing at room temperature for 86.4 hours. Precipitates were washed to a FTIR analysis of the white precipitate showed it to be alpha benzoin oxime. Since the basic After 86.4 hours, no precipitate had formed in bottles containing sodium hypochlorite. Black precipitate had formed in all bottles that did not contain sodium hypochlorite after 14.4 hours. The precipitate appeared to initially form on the surface of the HDPE sample bottles and Black precipitate was first noticed in sample set 1 after 28.8 hrs' irradiation. No visible sample containing precipitate was kept at room temperature in the original bottle. Precipitate in sample sets 2 and 3. Since no precipitate formed in these bottles, this was equivalent to duplicate samples. Once the precipitate in the 20-mL aliquots that had been set aside had returned to sample sets 1 through 3 and the samples with redissolved precipitate all experienced an average decrease in base strength of 0.013 meq mL-l. Sample 1-C had a decrease of 0.004 meq mL-l and sample 1-D had returned to the initial value of 0.198 meq mL-l. Raman spectra for the black precipitate from samples l-C, 1-D and supplemental sample set 1 Fig. 2. Raman spectra of the black precipitate formed in 9%40 product solutions after 28.8,43.2, 72 and 86.4 hours of `oCo irradiation in Sandia's Gamma Irradiation Facility. increase with time, as seen in the titration of 1-C and 1-D samples

  8. Damage nucleation in Si during ion irradiation

    SciTech Connect

    Holland, O.W.; Fathy, D.; Narayan, J.

    1984-01-01

    Damage nucleation in single crystals of silicon during ion irradiation is investigated. Experimental results and mechanisms for damage nucleation during both room and liquid nitrogen temperature irradiation with different mass ions are discussed. It is shown that the accumulation of damage during room temperature irradiation depends on the rate of implantation. These dose rate effects are found to decrease in magnitude as the mass of the ions is increased. The significance of dose rate effects and their mass dependence on nucleation mechanisms is discussed.

  9. Irradiation of nitrogen-rich ices by swift heavy ions. Clues for the formation of ultracarbonaceous micrometeorites

    NASA Astrophysics Data System (ADS)

    Augé, B.; Dartois, E.; Engrand, C.; Duprat, J.; Godard, M.; Delauche, L.; Bardin, N.; Mejía, C.; Martinez, R.; Muniz, G.; Domaracka, A.; Boduch, P.; Rothard, H.

    2016-08-01

    Context. Extraterrestrial materials, such as meteorites and interplanetary dust particles, provide constraints on the formation and evolution of organic matter in the young solar system. Micrometeorites represent the dominant source of extraterrestrial matter at the Earth's surface, some of them originating from large heliocentric distances. Recent analyses of ultracarbonaceous micrometeorites recovered from Antarctica (UCAMMs) reveal an unusually nitrogen-rich organic matter. Such nitrogen-rich carbonaceous material could be formed in a N2-rich environment, at very low temperature, triggered by energetic processes. Aims: Several formation scenarios have been proposed for the formation of the N-rich organic matter observed in UCAMMs. We experimentally evaluate the scenario involving high energy irradiation of icy bodies subsurface orbiting at large heliocentric distances. Methods: The effect of Galactic cosmic ray (GCR) irradiation of ices containing N2 and CH4 was studied in the laboratory. The N2-CH4 (90:10 and 98:2) ice mixtures were irradiated at 14 K by 44 MeV Ni11+ and 160 MeV Ar15+ swift heavy ion beams. The evolution of the samples was monitored using in-situ Fourier transform infrared spectroscopy. The evolution of the initial ice molecules and new species formed were followed as a function of projectile fluence. After irradiation, the target was annealed to room temperature. The solid residue of the whole process left after ice sublimation was characterized in-situ by infrared spectroscopy, and the elemental composition was measured ex-situ. Results: The infrared bands that appear during irradiation allow us to identify molecules and radicals (HCN, CN-, NH3, ...). The infrared spectra of the solid residues measured at room temperature show similarities with that of UCAMMs. The results point towards the efficient production of a poly-HCN-like residue from the irradiation of N2-CH4 rich surfaces of icy bodies. The room temperature residue provides a viable

  10. Visible to deep ultraviolet range optical absorption of electron irradiated borosilicate glass

    NASA Astrophysics Data System (ADS)

    Wang, Tie-Shan; Duan, Bing-Huang; Tian, Feng; Peng, Hai-Bo; Chen, Liang; Zhang, Li-Min; Yuan, Wei

    2015-07-01

    To study the room-temperature stable defects induced by electron irradiation, commercial borosilicate glasses were irradiated by 1.2 MeV electrons and then ultraviolet (UV) optical absorption (OA) spectra were measured. Two characteristic bands were revealed before irradiation, and they were attributed to silicon dangling bond (E’-center) and Fe3+ species, respectively. The existence of Fe3+ was confirmed by electron paramagnetic resonance (EPR) measurements. After irradiation, the absorption spectra revealed irradiation-induced changes, while the content of E’-center did not change in the deep ultraviolet (DUV) region. The slightly reduced OA spectra at 4.9 eV was supposed to transform Fe3+ species to Fe2+ species and this transformation leads to the appearance of 4.3 eV OA band. By calculating intensity variation, the transformation of Fe was estimated to be about 5% and the optical absorption cross section of Fe2+ species is calculated to be 2.2 times larger than that of Fe3+ species. Peroxy linkage (POL, ≡Si-O-O-Si≡), which results in a 3.7 eV OA band, is speculated not to be from Si-O bond break but from Si-O-B bond, Si-O-Al bond, or Si-O-Na bond break. The co-presence defect with POL is probably responsible for 2.9-eV OA band. Project supported by the Fundamental Research Funds for the Central Universities of China (Grant No. lzujbky-2014-16).

  11. Locker Room Design Trends.

    ERIC Educational Resources Information Center

    Wiens, Janet

    2001-01-01

    Examines how today's college and university athletic locker rooms have become sophisticated recruiting tools that rival many professional facilities. Locker room design and location and their level of furniture, finishes, and equipment are discussed as is the trend for more environmentally friendly locker rooms. (GR)

  12. Locker Room Design Trends.

    ERIC Educational Resources Information Center

    Wiens, Janet

    2001-01-01

    Examines how today's college and university athletic locker rooms have become sophisticated recruiting tools that rival many professional facilities. Locker room design and location and their level of furniture, finishes, and equipment are discussed as is the trend for more environmentally friendly locker rooms. (GR)

  13. SHMUTZ & PROTON-DIAMANT H + Irradiated/Written-Hyper/Super-conductivity(HC/SC) Precognizance/Early Experiments Connections: Wet-Graphite Room-Tc & Actualized MgB2 High-Tc: Connection to Mechanical Bulk-Moduli/Hardness: Diamond Hydrocarbon-Filaments, Disorder, Nano-Powders:C,Bi,TiB2,TiC

    NASA Astrophysics Data System (ADS)

    Wunderman, Irwin; Siegel, Edward Carl-Ludwig; Lewis, Thomas; Young, Frederic; Smith, Adolph; Dresschhoff-Zeller, Gieselle

    2013-03-01

    SHMUTZ: ``wet-graphite''Scheike-....[Adv.Mtls.(7/16/12)]hyper/super-SCHMUTZ-conductor(S!!!) = ``wet''(?)-``graphite''(?) = ``graphene''(?) = water(?) = hydrogen(?) =ultra-heavy proton-bands(???) = ...(???) claimed room/high-Tc/high-Jc superconductOR ``p''-``wave''/ BAND(!!!) superconductIVITY and actualized/ instantiated MgB2 high-Tc superconductors and their BCS- superconductivity: Tc Siegel[ICMAO(77);JMMM 7,190(78)] connection to SiegelJ.Nonxline-Sol.40,453(80)] disorder/amorphous-superconductivity in nano-powders mechanical bulk/shear(?)-moduli/hardness: proton-irradiated diamond, powders TiB2, TiC,{Siegel[Semis. & Insuls.5:39,47, 62 (79)])-...``VS''/concommitance with Siegel[Phys.Stat.Sol.(a)11,45(72)]-Dempsey [Phil.Mag. 8,86,285(63)]-Overhauser-(Little!!!)-Seitz-Smith-Zeller-Dreschoff-Antonoff-Young-...proton-``irradiated''/ implanted/ thermalized-in-(optimal: BOTH heat-capacity/heat-sink & insulator/maximal dielectric-constant) diamond: ``VS'' ``hambergite-borate-mineral transformable to Overhauser optimal-high-Tc-LiBD2 in Overhauser-(NW-periodic-table)-Land: CO2/CH4-ETERNAL-sequestration by-product: WATER!!!: physics lessons from

  14. Effect of positron source irradiation on positronium annihilation in fine powdered alumina

    NASA Astrophysics Data System (ADS)

    Liu, Z. W.; Chen, Z. Q.

    2016-09-01

    Positron lifetime and Doppler broadening of positron annihilation radiation were measured as a function of time to study the irradiation effect by 22Na positron source in fine powdered alumina. The γ-Al2O3 samples were put in a vacuum chamber with a pressure of about 10-6 Torr and were cooled down to 10 K by a closed-cycle helium gas refrigerator. The irradiation of γ-Al2O3 samples by positron source was taken for a duration of about two days immediately after the sample was cooled down. After that, the sample was subjected to a warm up process from 10 K to 300 K with a step of 10 K. Positron lifetime and Doppler broadening spectra were measured simultaneously during these processes. Two long lifetime components corresponding to ortho-positronium annihilation were observed. A significant shortening of these long lifetime components and a large increase in S parameter is observed during irradiation. It is supposed that positron source irradiation creates a large number of paramagnetic centers on the surface of the γ-Al2O3 grains, which induce spin conversion quenching of positronium. The irradiation induced paramagnetic centers are unstable above 70 K and are nearly annealed out when the temperature rises to 190 K. After warming up of the sample to room temperature, the positron lifetime spectrum is identical to that before irradiation. It was also found that after irradiation, a medium long lifetime component of about 5 ns appears, of which the intensity increases with increasing irradiation time. This may be originated from the formation of the surface o-Ps state. This surface o-Ps state is also inhibited at elevated temperatures. Our results indicate that positronium is a very sensitive probe for the surface defects in porous materials.

  15. Characterization and antioxidant properties of alcoholic extracts from gamma irradiated κ-carrageenan

    NASA Astrophysics Data System (ADS)

    Relleve, Lorna; Abad, Lucille

    2015-07-01

    Different extracts from unirradiated and gamma irradiated κ-carrageenan (solid and 1% w/v aqueous solution) were obtained with isopropyl alcohol (IPA) at concentrations of 40%, 60% and 80% v/v at room temperature. Physical and chemical properties of the different IPA extracts were analyzed by GPC, UV, and FT-IR. The extracts consisted of low molecular weight fragments with an average molecular weight (Mw) ranging from 2300 Da to 5000 Da. UV analyses of extracts from irradiated carrageenan showed varying maximum absorptions in the range of 265-280 nm. FT-IR spectra of all extracts from irradiated carrageenan showed all the important functional groups of carrageenan in the fingerprint region (4000-600 cm-1) and additional carbonyl C=O and C=C double bond peaks. Antioxidant properties of the different extracts were investigated using reducing power assay. The reducing power of extracts from the irradiated solution follows the order of 80%>60%>40% while no trend was observed for all extracts from irradiated solid κ-carrageenan.

  16. Room-temperature near-infrared electroluminescence from boron-diffused silicon pn junction diodes

    NASA Astrophysics Data System (ADS)

    Li, Si; Gao, Yuhan; Fan, Ruixin; Li, Dongsheng; Yang, Deren

    2015-02-01

    Silicon pn junction diodes with different doping concentrations were prepared by boron diffusion into Czochralski (CZ) n-type silicon substrate. Their room-temperature near-infrared electroluminescence (EL) was measured. In the EL spectra of the heavily boron doped diode, a luminescence peak at ~1.6 μm (0.78 eV ) was observed besides the band-to-band line (~1.1eV) under the condition of high current injection, while in that of the lightly boron doped diode only the band-to-band line was observed. The intensity of peak at 0.78 eV increases exponentially with current injection with no observable saturation at room temperature. Furthermore, no dislocations were found in the cross-sectional transmission electron microscopy image, and no dislocation-related luminescence was observed in the low-temperature photoluminescence spectra. We deduce the 0.78 eV emission originates from the irradiative recombination in the strain region of diodes caused by the diffusion of large number of boron atoms into silicon crystal lattice.

  17. EPR study of gamma irradiated DL-methionine sulfone single crystals

    NASA Astrophysics Data System (ADS)

    Karabulut, Bünyamin; Yıldırım, İlkay

    2015-12-01

    Electron paramagnetic resonance (EPR) study of gamma irradiated dl-2-amino-4-(Methylsulfonyl) butyric acid (dl-methionine sulfone, hereafter dl-ABA) single crystals and powder was performed at room temperature. It has been found that this compound indicates the existence of C. O2- and N. H2 radicals after γ-irradiation. While g and hyperfine splitting values for the N. H2 radical were observed, for the C. O2- radical, only the g factor was measured. The EPR spectra have shown that N. H2 radical has two groups each having two distinct sites and C. O2- radical has one site. The principal g and hyperfine values for all sites were analyzed.

  18. Temperature, stress, and annealing effects on the luminescence from electron-irradiated silicon

    NASA Technical Reports Server (NTRS)

    Jones, C. E.; Johnson, E. S.; Compton, W. D.; Noonan, J. R.; Streetman, B. G.

    1973-01-01

    Low-temperature photoluminescence spectra are presented for Si crystals which have been irradiated with high-energy electrons. Studies of isochronal annealing, stress effects, and the temperature dependences of the luminescence are used to discuss the nature of the luminescent transitions and the properties of defects. Two dominant bands present after room-temperature anneal of irradiated material are discussed, and correlations of the properties of these bands are made with known Si defects. A band between 0.8 and 1.0 eV has properties which are related to those of the divacancy, and a band between 0.6 and 0.8 eV has properties related to those of the Si-G15(K) center. Additional peaks appear in the luminescence after high-temperature anneal; the influence of impurities and the effects of annealing of these lines are discussed.

  19. Temperature, stress, and annealing effects on the luminescence from electron-irradiated silicon

    NASA Technical Reports Server (NTRS)

    Jones, C. E.; Johnson, E. S.; Compton, W. D.; Noonan, J. R.; Streetman, B. G.

    1973-01-01

    Low-temperature photoluminescence spectra are presented for Si crystals which have been irradiated with high-energy electrons. Studies of isochronal annealing, stress effects, and the temperature dependences of the luminescence are used to discuss the nature of the luminescent transitions and the properties of defects. Two dominant bands present after room-temperature anneal of irradiated material are discussed, and correlations of the properties of these bands are made with known Si defects. A band between 0.8 and 1.0 eV has properties which are related to those of the divacancy, and a band between 0.6 and 0.8 eV has properties related to those of the Si-G15(K) center. Additional peaks appear in the luminescence after high-temperature anneal; the influence of impurities and the effects of annealing of these lines are discussed.

  20. Video-based ocean wave spectra

    NASA Astrophysics Data System (ADS)

    Harbitz, Alf

    1994-07-01

    A particular video spot detector provides an irradiance time series from an arbitrarily chosen pixel in the video frame. The detector is applied to video records of the ocean surface, and the correspondence between the 1D irradiance frequency spectrum and the corresponding ocean surface elevation spectrum is studied. A major experimental results is that the frequency peak in the irradiance spectrum for a typical wind-driven sea is significantly enhanced compared to the surface slope spectrum. Video experiments from the oil rig Gullfaks A in the North Sea show an excellent agreement between the enhanced peak frequency in the irradiance spectrum and the peak frequency in the surface elevation spectrum measured by a microwave remote ocean surveillance wave radar. The enhancement of the peak in the irradiance spectrum is explained by a strong nonlinear geometrical projection effect. This is due to the rather small look angle with the horizontal, which is chosen so as to neglect irradiance contributions from beneath the sea surface. Based on a simple stochastic model that takes the geometric effect into account, irradiance spectra are simulated and are in good agreement with the experimental spectra.

  1. In-growth of an electrically active defect in high-purity silicon after proton irradiation

    SciTech Connect

    Nylandsted Larsen, A.; Juul Pedersen, H.; Christian Petersen, M.; Privitera, V.; Gurimskaya, Y.; Mesli, A.

    2013-12-14

    Defect-related energy levels in the lower half of the band gap of silicon have been studied with transient-capacitance techniques in high-purity, carbon and oxygen lean, plasma-enhanced chemical-vapor deposition grown, n-and p-type silicon layers after 2-MeV proton irradiations at temperatures at or just below room temperature. The in-growth of a distinct line in deep-level transient spectroscopy spectra, corresponding to a level in the band gap at E{sub V} + 0.357 eV where E{sub V} is the energy of the valence band edge, takes place for anneal temperatures at around room temperature with an activation energy of 0.95 ± 0.08 eV. The line disappears at an anneal temperature of around 450 K. The corresponding defect is demonstrated not to contain boron, carbon, oxygen, or phosphorus. Possible defect candidates are discussed.

  2. Proton irradiation of simple gas mixtures: Influence of irradiation parameters

    NASA Technical Reports Server (NTRS)

    Sack, Norbert J.; Schuster, R.; Hofmann, A.

    1990-01-01

    In order to get information about the influence of irradiation parameters on radiolysis processes of astrophysical interest, methane gas targets were irradiated with 6.5 MeV protons at a pressure of 1 bar and room temperature. Yields of higher hydrocarbons like ethane or propane were found by analysis of irradiated gas samples using gas chromatography. The handling of the proton beam was of great experimental importance for determining the irradiation parameters. In a series of experiments current density of the proton beam and total absorbed energy were shown to have a large influence on the yields of produced hydrocarbons. Mechanistic interpretations of the results are given and conclusions are drawn with regard to the chemistry and the simulation of various astrophysical systems.

  3. Investigation of 60Co γ-irradiated L-(-) malic acid, N-methyl- DL-valine and L-glutamic acid γ-ethyl ester by electron paramagnetic resonance technique

    NASA Astrophysics Data System (ADS)

    Başkan, M. Halim; Aydın, Murat; Osmanoğlu, Şemsettin

    The electron paramagnetic resonance spectra of γ-irradiated L-(-) malic acid, N-methyl- DL-valine and L-glutamic acid γ-ethyl ester powders have been investigation at room temperature. Radiation damage centres are attributed to HOOCCH 2ĊHCOOH, (CH 3) 2ĊCH(NHCH 3)COOH and C 2H 5OCOCH 2CH 2Ċ(NH 2)COOH radicals, respectively. The spectra have been computer simulated. The EPR parameters of the observed radicals have been determined and discussed.

  4. Ultraviolet emission spectra of sunbeds.

    PubMed

    Gerber, Beat; Mathys, Patrick; Moser, Mirjana; Bressoud, Dominique; Braun-Fahrländer, Charlotte

    2002-12-01

    It is well known that UV radiation contributes to the development of skin cancer. Exposure to solar radiation is predominantly responsible for the high incidence rate of skin cancer, but there are also indications that sunbeds are involved. The aim of the present investigation was to determine the UV emission spectra of sunbeds. It included the most common sunbed models, which cover more than 50% of the Swiss market. The UV emission spectra of sunbeds have special characteristics and are different from the sun spectrum, which can be seen in high-resolution spectral measurements. Sunbed emission spectra are similar to the sun spectrum in the UVB (280-320 nm) range but reach values 10 to 15 times higher in the UVA (320-400 nm) range. An average erythema-effective irradiance of 0.33 W/m2 was determined for sunbeds. This corresponds to a UV index of 13, which is significantly higher than the UV index of 8.5 of the high summer sun at noon at intermediate latitudes. The measurements were spread over the whole effective area of the sunbeds, and an inhomogeneous distribution of the irradiances with variations of up to 30% from the average value was found.

  5. EPR study on gamma-irradiated fruits dehydrated via osmosis

    NASA Astrophysics Data System (ADS)

    Yordanov, N. D.; Aleksieva, K.

    2007-06-01

    The shape and time stability of the electron paramagnetic resonance (EPR) spectra of non- and γ-irradiated papaya, melon, cherry and fig samples dehydrated via osmosis are reported. It is shown that non-irradiated samples are generally EPR silent whereas γ-irradiated exhibit "sugar-like" EPR spectra. The recorded EPR spectra are monitored for a period of 7 months after irradiation (stored at low humidity and in the dark). The results suggest longer period of unambiguous identification of the radiation processing of osmose dehydrated fruits. Therefore, the Protocol EN 13708,2001 issued by CEN is fully applicable for the studied fruit samples.

  6. Thermoluminescence study of X-ray and UV irradiated natural calcite and analysis of its trap and recombination level.

    PubMed

    Kalita, J M; Wary, G

    2014-05-05

    Thermoluminescence (TL) of natural light-orange color calcite (CaCO3) mineral in micro-grain powder form was studied at room temperature X-ray and UV irradiation under various irradiation times. TL was recorded in linear heating rate (2 K/s) from room temperature (300 K) to 523 K. Trapping parameters such as activation energy, order of kinetics, frequency factor have been evaluated by Computerized Glow Curve Deconvolution technique. Three electron trap centers had been estimated at depth 0.70, 1.30 and 1.49 eV from the conduction band. Investigation of emission spectra recorded at various temperatures showed single recombination center at depth 2.74 eV from the conduction band. Due to thermally assisted tunneling of electron and subsequent center-to-center recombination, a distinct peak of lower activation energy (0.60 eV) was observed at relatively higher temperature (~360 K) for X-ray irradiated sample. In UV excitation, there was an indication of photo-transfer phenomenon, where low TL intensity might have been observed; but due to simultaneous excitation of electrons from valence band to the trap level, TL intensity was found to increase with UV irradiation time. The results obtained within temperature range 300-523 K were explained by considering a band diagram. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Status of Post Irradiation Examination of FCAB and FCAT Irradiation Capsules

    SciTech Connect

    Field, Kevin G.; Yamamoto, Yukinori; Howard, Richard H.

    2016-09-29

    A series of irradiation programs are ongoing to address the need for determining the radiation tolerance of FeCrAl alloys. These irradiation programs, deemed the FCAT and FCAB irradiation programs, use the High Flux Isotope Reactor (HFIR) to irradiate second generation wrought FeCrAl alloys and early-generation powder-metallurgy (PM) oxide dispersion-strengthened (ODS) FeCrAl alloys. Irradiations have been or are being performed at temperatures of 200°C, 330°C, and 550°C from doses of 1.8 dpa up to 16 dpa. Preliminary post-irradiation examination (PIE) on low dose (<2 dpa) irradiation capsules of tensile specimens has been performed. Analysis of co-irradiated SiC thermometry have shown reasonable matching between the nominal irradiation temperatures and the target irradiation temperatures. Room temperature tensile tests have shown typical radiation-induced hardening and embrittlement at irradiations of 200°C and 330°C, but a propensity for softening when irradiated to 550°C for the wrought alloys. The PM-ODS FeCrAl specimens showed less hardening compared to the wrought alloys. Future PIE includes high temperature tensile tests on the low dose irradiation capsules as well as the determination of reference fracture toughness transition temperature, To, in alloys irradiated to 7 dpa and higher.

  8. Photoinduced changes in the Raman spectra of germanosilicate optical fibres

    SciTech Connect

    Vasil'ev, Sergei A; Dianov, Evgenii M; Koltashev, V V; Mashinsky, V M; Medvedkov, O I; Plotnichenko, V G; Pyrkov, Yu N; Sazhin, O D; Frolov, A A; Marchenko, V M

    1998-04-30

    An investigation was made of changes in the Raman spectra of germanosilicate optical fibres as a result of UV irradiation. The photoinduced changes in the spectra were of the same nature for all types of irradiation used. These changes increased with increase in the radiation dose and in the GeO{sub 2} concentration in the fibre core and were evidence of a structural modification of glass. (nonlinear optical phenomena and devices)

  9. ESR study of free radicals in UHMW-PE fiber irradiated by gamma rays

    NASA Astrophysics Data System (ADS)

    Zhao, Yanning; Wang, Mouhua; Tang, Zhongfeng; Wu, Guozhong

    2010-04-01

    ESR spectra of the trapped radicals in an ultra-high molecular weight polyethylene (UHMW-PE) fiber irradiated by gamma rays showed well-resolved hyperfine splitting at room temperature since the c-axis of the crystallites is aligned with the fiber direction and the radicals are trapped in crystallites. The alkyl radical (-CH 2- •CH-CH 2-) was the major product after irradiation in vacuum and in air at room temperature. Some of the alkyl radicals converted to allyl radicals (-CH 2- •CH-CH=CH-) and polyenyl radicals (-CH 2- •CH-(CH=CH) n-CH 2-) during storage in vacuum. Upon storage in air atmosphere, the alkyl radicals decayed by reaction with oxygen. Of particular interest is the very slow decay rate of the alkyl radical trapped in UHMW-PE fiber, the half-life is 26 days in vacuum, and 13 days in air at room temperature, which is about 1/30 and 1/100 of that reported for high density polyethylene (HDPE), respectively. The extremely long lifetime of the alkyl radical is supposed to be caused by the large size of crystallites in UHMW-PE fiber. The rate of radical decay was accelerated by annealing at elevated temperature.

  10. The Upstairs Room - Room for Controversy?

    ERIC Educational Resources Information Center

    Poole, Mary F.

    1973-01-01

    Doubtless everyone is tired of the subject of censorship; but I do have to give vent to my feelings when they are as intense as they are over the selection of a book as full of profanity as a Newbery honor book ( The Upstairs Room''). (Author/SM)

  11. Further characterization of oxygen vacancies and zinc vacancies in electron-irradiated ZnO

    SciTech Connect

    Evans, S. M.; Giles, N. C.; Halliburton, L. E.; Kappers, L. A.

    2008-02-15

    Electron paramagnetic resonance (EPR) has been used to monitor oxygen vacancies and zinc vacancies in a ZnO crystal irradiated near room temperature with 1.5 MeV electrons. Out-of-phase detection at 30 K greatly enhances the EPR signals from these vacancies. Following the electron irradiation, but before illumination, Fe{sup 3+} ions and nonaxial singly ionized zinc vacancies are observed. Illumination with 325 nm laser light at low temperature eliminates the Fe{sup 3+} signal while producing spectra from singly ionized oxygen vacancies, neutral zinc vacancies, and axial singly ionized zinc vacancies. This light also produces EPR spectra from zinc vacancies having a OH{sup -} ion at an adjacent oxygen site. The low-temperature response of the irradiated crystal to illumination wavelengths between 350 and 750 nm is described. Wavelengths shorter than 600 nm convert Fe{sup 3+} ions to Fe{sup 2+} ions and convert neutral oxygen vacancies to singly ionized oxygen vacancies. Neutral zinc vacancies are formed by wavelengths shorter than 500 nm as electrons are removed from isolated singly ionized zinc vacancies. Warming above 120 K in the dark reverses the effect of the illuminations. These wavelength-dependence results suggest that the ground state of the neutral oxygen vacancy is deep, approximately 1.3 eV above the valence band, and that the ground state of the singly ionized zinc vacancy is also deep, about 0.9 eV above the valence band.

  12. An electron spin double resonance study of x-ray irradiated phenacyl chloride single crystals

    NASA Astrophysics Data System (ADS)

    Hwang, J. S.; Wang, H. C.; Andersson, B.; Kispert, L. D.; Geoffroy, M.

    1981-10-01

    Single crystals of phenacyl chloride irradiated at room temperature give rise to an EPR spectrum that has been shown by ENDOR and ELDOR studies to be due to the radical The EPR spectra are complicated by the appearance of a large number of forbidden lines due to the presence of a chlorine quadrupole interaction similar in magnitude to the proton hyperfine coupling. Spectral assignment is not possible by considering the EPR spectra alone. Although ENDOR spectra are difficult to obtain, it is possible to obtain an ENDOR spectrum along one of the crystal axis that identifies the spectra as due to radical I. Furthermore, rather intense and highly resolved ELDOR spectra are obtained at -60 °C as a function of angle enabling the chlorine and proton magnetic hyperfine tensor components of the -ĊHCl fragment to be determined as -15.4, -8.3, +45.6 MHz and -26.5, -52.5, -80.0 MHz, respectively. The Qzz components of the chlorine quadrupole tensor is -11.2 MHz.

  13. Strengthening Weight Rooms.

    ERIC Educational Resources Information Center

    Sherman, Rachel M.

    1997-01-01

    Examines ways of giving an existing weight-training room new life without spending a lot of time and money. Tips include adding rubber floor coverings; using indirect lighting; adding windows, art work, or mirrors to open up the room; using more aesthetically pleasing ceiling tiles; upgrading ventilation; repadding or painting the equipment; and…

  14. Computer Room Water Protection.

    ERIC Educational Resources Information Center

    Price, Bennett J.

    1990-01-01

    Addresses the protection of computer rooms from water. Sources of water and potentially vulnerable areas in computer rooms are described. Water detection is then discussed, and several detection systems are detailed. Prices and manufacturers' telephone numbers for some of the systems are included. Water cleanup is also briefly considered. (MES)

  15. Strengthening Weight Rooms.

    ERIC Educational Resources Information Center

    Sherman, Rachel M.

    1997-01-01

    Examines ways of giving an existing weight-training room new life without spending a lot of time and money. Tips include adding rubber floor coverings; using indirect lighting; adding windows, art work, or mirrors to open up the room; using more aesthetically pleasing ceiling tiles; upgrading ventilation; repadding or painting the equipment; and…

  16. Unlocking the Locker Room.

    ERIC Educational Resources Information Center

    St. Clair, Dean

    1996-01-01

    Discusses locker-room design standards and common challenges when complying with the Americans with Disabilities Act. Accessibility and safety considerations for shower, toilet, and locker areas are addressed, as are entrance vestibules, drying and grooming areas, and private dressing rooms. (GR)

  17. Clean room wiping liquids

    SciTech Connect

    Harding, W.B.

    1991-12-01

    A water-based liquid containing isopropyl alcohol, ammonium hydroxide, and surfactants was developed to replace 1,1,2-trichlorotrifluoroethane for the dampening of clean room wiping cloths used to wipe clean benches, clean room equipment, and latex finger cots and gloves.

  18. Tissue irradiator

    DOEpatents

    Hungate, F.P.; Riemath, W.F.; Bunnell, L.R.

    1975-12-16

    A tissue irradiator is provided for the in-vivo irradiation of body tissue. The irradiator comprises a radiation source material contained and completely encapsulated within vitreous carbon. An embodiment for use as an in- vivo blood irradiator comprises a cylindrical body having an axial bore therethrough. A radioisotope is contained within a first portion of vitreous carbon cylindrically surrounding the axial bore, and a containment portion of vitreous carbon surrounds the radioisotope containing portion, the two portions of vitreous carbon being integrally formed as a single unit. Connecting means are provided at each end of the cylindrical body to permit connections to blood- carrying vessels and to provide for passage of blood through the bore. In a preferred embodiment, the radioisotope is thulium-170 which is present in the irradiator in the form of thulium oxide. A method of producing the preferred blood irradiator is also provided, whereby nonradioactive thulium-169 is dispersed within a polyfurfuryl alcohol resin which is carbonized and fired to form the integral vitreous carbon body and the device is activated by neutron bombardment of the thulium-169 to produce the beta-emitting thulium-170.

  19. [Food irradiation].

    PubMed

    Migdał, W

    1995-01-01

    A worldwide standard on food irradiation was adopted in 1983 by Codex Alimentarius Commission of the Joint Food Standard Programme of the Food and Agriculture Organization (FAO) of the United Nations and the World Health Organization (WHO). As a result, 41 countries have approved the use of irradiation for treating one or more food items and the number is increasing. Generally, irradiation is used to: food loses, food spoilage, disinfestation, safety and hygiene. The number of countries which use irradiation for processing food for commercial purposes has been increasing steadily from 19 in 1987 to 33 today. In the frames of the national programme on the application of irradiation for food preservation and hygienization an experimental plant for electron beam processing has been established in Institute of Nuclear Chemistry and Technology. The plant is equipped with a small research accelerator Pilot (19MeV, 1 kW) and an industrial unit Elektronika (10MeV, 10 kW). On the basis of the research there were performed at different scientific institutions in Poland, health authorities have issued permission for irradiation for: spices, garlic, onions, mushrooms, potatoes, dry mushrooms and vegetables.

  20. Free radical kinetics on irradiated fennel

    NASA Astrophysics Data System (ADS)

    Yamaoki, Rumi; Kimura, Shojiro; Ohta, Masatoshi

    2008-09-01

    Herein, an electron spin resonance study on the behavior of organic radicals in fennel before and after irradiation is reported. The spectrum of irradiated fennel composed of the spectrum component derived from the un-irradiated sample (near g=2.005) and the spectra components derived from carbohydrates. The time decay of intensity spectral components was well explained by first-order kinetics with a variety of rate constants. Especially, the signal at near g=2.02 ascribed to stable cellulose-derivative components is expected to be a good indicator in the identification of irradiated plant samples.

  1. A study on the effect of gamma irradiation on Poly [-Ethylene Oxide]: structural modification and variation in the kinetics of isoconversional phenomena

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, M.; Saha, M.; Ray, R.; Tarafdar, S.

    2016-10-01

    Interactions of Poly [-Ethylene Oxide] [PEO of molecular weight 105] and gamma irradiation with variable doses (1-30 kGy) are studied for the thermal, crystalline and structural properties using differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) technique. Two states of PEO, viz. powder (P-S-series) and methanol solution (P-L-series) are subjected to irradiation and then cast into uniform films at room temperature. DSC results have revealed steady increment of crystallinity up to 20 kGy for P-S-series which starts reducing till 30 kGy. Conversely, P-L-series shows much enhanced crystallinity retained within low irradiation regime of 7 kGy, followed by sharp declining trend till 30 kGy. DSC is employed to study the influence of gamma radiation on multiple kinetic processes in an isoconversional melting of PEO using Friedman differential analysis. This study illustrates the variation of activation with degree of conversion of melting for different doses on irradiated PEO powder and methanol solution. Gamma irradiation is found to generate newer functional groups which are also established from FTIR study. Presence of -C=O and -C=C- groups in FTIR spectra reveals the predominance of scission during air assisted irradiation. FTIR spectra also prove higher degree of cross-linking in irradiation of methanol solution. The observations of DSC and FTIR are correlated with polymer microstructures. Therefore, selective irradiation dose can effectively be utilized to tailor the properties of PEO depending upon the exposed powder or methanol solution of polymer.

  2. Operating Room Fire Safety

    PubMed Central

    Hart, Stuart R.; Yajnik, Amit; Ashford, Jeffrey; Springer, Randy; Harvey, Sherry

    2011-01-01

    Operating room fires are a rare but preventable danger in modern healthcare operating rooms. Optimal outcomes depend on all operating room personnel being familiar with their roles in fire prevention and fire management. Despite the recommendations of major safety institutes, this familiarity is not the current practice in many healthcare facilities. Members of the anesthesiology and the surgery departments are commonly not actively involved in fire safety programs, fire drills, and fire simulations that could lead to potential delays in prevention and management of intraoperative fires. PMID:21603334

  3. [Single-patient rooms].

    PubMed

    Jensen, Elisabeth Brøgger

    2009-05-18

    The Danish government has allocated funding to achieve the goal of replacing 50% of all existing hospital buildings by new facilities. Facing such a building boom, the debate for and against single-patient rooms is in progress. A review of the literature shows that single-patient rooms have a direct impact on patient safety. Patient Safety Leadership Walkrounds and failure modes and effects analysis can be used for identifying risks before designing single rooms in future hospitals. The acuity adaptability model needs to be revised.

  4. Transformer room fire tests

    NASA Astrophysics Data System (ADS)

    Fustich, C. D.

    1980-03-01

    A series of transformer room fire tests are reported to demonstate the shock hazard present when automatic sprinklers operate over energized electrical equipment. Fire protection was provided by standard 0.5 inch pendent automatic sprinklers temperature rated at 135 F and installed to give approximately 150 sq ft per head coverage. A 480 v dry transformer was used in the room to provide a three phase, four wire distribution system. It is shown that the induced currents in the test room during the various tests are relatively small and pose no appreciable personnel shock hazard.

  5. The effect of irradiation temperature on the non-enzymatic browning reaction in cooked rice

    NASA Astrophysics Data System (ADS)

    Lee, Ju-Woon; Oh, Sang-Hee; Kim, Jae-Hun; Byun, Eui-Hong; Ree Kim, Mee; Baek, Min; Byun, Myung-Woo

    2007-05-01

    The effect of irradiation temperature on the non-enzymatic browning reaction in a sugar-glycine solution and cooked rice generated by gamma irradiation was evaluated in the present study. When the sugar-glycine solution and cooked rice were irradiated at room temperature, the browning reaction was dramatically increased during the post-irradiation period. In the case of irradiation at below the freezing point, the browning by irradiation was retarded during not only irradiation but also a post-irradiation period. The changes of the sugar profile, such as a sugar loss or reducing power of the irradiated sugar-glycine solution and the electron spin resonance signal intensity of the irradiated cooked rice were also decreased with lower irradiation temperature. The present results may suggest that the production of free radicals and a radiolysis product is inhibited during gamma irradiation in the frozen state and it may prevent the browning reaction generated by gamma irradiation from occurring.

  6. Central room (delivery room on plan) between the east and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Central room (delivery room on plan) between the east and west reading rooms, showing built-in card catalog drawers. View to south. - Sacramento Junior College, Library, 3835 Freeport Boulevard, Sacramento, Sacramento County, CA

  7. Men's toilet (room 207, representing rooms 306, 406, and 506; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Men's toilet (room 207, representing rooms 306, 406, and 506; also women's toilets, rooms 102, 104, 204, 204A, 303, 403, and 503), looking north. - California State Office Building No. 1, 915 Capitol Mall, Sacramento, Sacramento County, CA

  8. Interior. Balance room for chemistry laboratory. Storage room for glassware ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior. Balance room for chemistry laboratory. Storage room for glassware and reference room with frequently used chemistry and chemical engineering texts. - Thomas A. Edison Laboratories, Building No. 2, Main Street & Lakeside Avenue, West Orange, Essex County, NJ

  9. QUARTERS B, DINING ROOM. LIVING ROOM ON LEFT AND KITCHEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    QUARTERS B, DINING ROOM. LIVING ROOM ON LEFT AND KITCHEN TO RIGHT SHOWING DOORS TO LIVING ROOM. - Naval Magazine Lualualei, West Loch Branch, Warrant Officers & Civilian Quarters, B Avenue, Pearl City, Honolulu County, HI

  10. Interior. Balance room for chemistry laboratory. Storage room for glassware ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior. Balance room for chemistry laboratory. Storage room for glassware and reference room with frequently used chemistry and chemical engineering texts. - Thomas A. Edison Laboratories, Building No. 2, Main Street & Lakeside Avenue, West Orange, Essex County, NJ

  11. Irradiation subassembly

    DOEpatents

    Seim, O.S.; Filewicz, E.C.; Hutter, E.

    1973-10-23

    An irradiation subassembly for use in a nuclear reactor is described which includes a bundle of slender elongated irradiation -capsules or fuel elements enclosed by a coolant tube and having yieldable retaining liner between the irradiation capsules and the coolant tube. For a hexagonal bundle surrounded by a hexagonal tube the yieldable retaining liner may consist either of six segments corresponding to the six sides of the tube or three angular segments each corresponding in two adjacent sides of the tube. The sides of adjacent segments abut and are so cut that metal-tometal contact is retained when the volume enclosed by the retaining liner is varied and Springs are provided for urging the segments toward the center of the tube to hold the capsules in a closely packed configuration. (Official Gazette)

  12. Carpenter in White Room

    NASA Technical Reports Server (NTRS)

    1962-01-01

    Inside Hangar S at the White Room Facility at Cape Canaveral, Florida, Mercury astronaut M. Scott Carpenter examines the honeycomb protective material on the main pressure bulkhead (heat shield) of his Mercury capsule nicknamed 'Aurora 7.'

  13. Fracture surfaces of irradiated composites

    NASA Technical Reports Server (NTRS)

    Milkovich, Scott M.; Sykes, George F., Jr.; Herakovich, Carl T.

    1987-01-01

    Electron microscopy was used to analyze the fracture surfaces of T300/934 graphite/epoxy unidirectional off-axis tensile coupons which were subjected to 1.0-MeV electron radiation at a rate of 50 Mrad/h for a total dose of 10 Grad. Fracture surfaces from irradiated and nonirradiated specimens tested at 116 K, room temperature, and 394 K were analyzed to assess the influence of radiation and temperature on the mode of failure and variations in constituent material as a function of environmental exposure. Micrographs of fracture surfaces indicate that irradiated specimens are more brittle than nonirradiated specimens at low temperatures. However, at elevated temperatures the irradiated specimens exhibit significantly more plasticity than nonirradiated specimens.

  14. Novel room temperature ferromagnetic semiconductors

    SciTech Connect

    Gupta, Amita

    2004-06-01

    Today's information world, bits of data are processed by semiconductor chips, and stored in the magnetic disk drives. But tomorrow's information technology may see magnetism (spin) and semiconductivity (charge) combined in one 'spintronic' device that exploits both charge and 'spin' to carry data (the best of two worlds). Spintronic devices such as spin valve transistors, spin light emitting diodes, non-volatile memory, logic devices, optical isolators and ultra-fast optical switches are some of the areas of interest for introducing the ferromagnetic properties at room temperature in a semiconductor to make it multifunctional. The potential advantages of such spintronic devices will be higher speed, greater efficiency, and better stability at a reduced power consumption. This Thesis contains two main topics: In-depth understanding of magnetism in Mn doped ZnO, and our search and identification of at least six new above room temperature ferromagnetic semiconductors. Both complex doped ZnO based new materials, as well as a number of nonoxides like phosphides, and sulfides suitably doped with Mn or Cu are shown to give rise to ferromagnetism above room temperature. Some of the highlights of this work are discovery of room temperature ferromagnetism in: (1) ZnO:Mn (paper in Nature Materials, Oct issue, 2003); (2) ZnO doped with Cu (containing no magnetic elements in it); (3) GaP doped with Cu (again containing no magnetic elements in it); (4) Enhancement of Magnetization by Cu co-doping in ZnO:Mn; (5) CdS doped with Mn, and a few others not reported in this thesis. We discuss in detail the first observation of ferromagnetism above room temperature in the form of powder, bulk pellets, in 2-3 mu-m thick transparent pulsed laser deposited films of the Mn (<4 at. percent) doped ZnO. High-resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS) spectra recorded from 2 to 200nm areas showed homogeneous distribution of Mn substituting

  15. [Effect of spectra on growth of chlorella and isochrysis].

    PubMed

    Mao, An-Jun; Wang, Jing; Lin, Xue-Zheng; Meng, Ji-Wu

    2008-05-01

    Focusing on the speed and efficiency, the effects of different spectra on the growth of chlorella vulgaris and isochrysis galbana Parke 8701 were investigated by using monochromatic LED (light-emitting diode) and fluorescent lamp as light sources. It was concluded that continuous spectra accelerate the top-growth-rate, blue light has the best efficiency, and the combination of them can obtain a good balance of speed and efficiency. For the purpose of measuring spectra as a parameter of irradiation quantitatively, spectra-absorbability-coefficient defined as the quanta-absorbability- efficiency of spectra for algae was calculated by means of absorption spectra of algae and emission spectra of light sources. Compared with the experimental results the coefficients of different light sources have a positive correlation to their efficiency for growth, so the coefficient can be used to elementarily quantify the relation between the spectra and the efficiency for growth.

  16. Preparation of vinyl acetate grafted natural rubber by irradiation method

    SciTech Connect

    Porntrairat, A.; Pattamaprom, C.

    2016-03-09

    Improvement in properties of natural rubber could be done by several methods. In this research, gamma radiation technique, which is simple, accurate, easy to control and clean, was applied to enhance the properties of natural rubber (NR) in latex state. The purpose of this research is to study the appropriate condition for preparing grafted natural rubber latex by using irradiation method. Vinyl acetate monomers (VAc) were grafted onto natural rubber latex (NR-g-PVAc) at 0-10 kGys by gamma radiation from Cobalt-60 source at room temperature. Physical properties of grafted natural rubber such as chloroform number, swelling ratio and gel content were measured. The VAc content of NR-g-PVAc was investigated by titration and visualized by FTIR spectroscopy. The FTIR spectra of NR-g-PVAc prepared at 0-10 kGys showed characteristic peaks of the vinyl acetate confirming that VAc could be grafted onto natural rubber molecular chains effectively under appropriate irradiation conditions. From the result, radiation grafting was found to be a useful technique for grafting of vinyl acetate onto natural rubber.

  17. Irradiated foods

    MedlinePlus

    ... it reduces the risk for food poisoning . Food irradiation is used in many countries. It was first approved in the U.S. to prevent sprouts on white potatoes, and to control insects on wheat and in certain spices and seasonings.

  18. High energy oxygen irradiation-induced defects in Fe-doped semi-insulating indium phosphide by positron annihilation technique

    NASA Astrophysics Data System (ADS)

    Pan, S.; Mandal, A.; Sohel, Md. A.; Saha, A. K.; Das, D.; Sen Gupta, A.

    2017-02-01

    Positron annihilation technique is applied to study the recovery of radiation-induced defects in 140 MeV oxygen (O6+) irradiated Fe-doped semi-insulating indium phosphide during annealing over a temperature region of 25∘C-650∘C. Lifetime spectra of the irradiated sample are fitted with three lifetime components. Trapping model analysis is used to characterize defect states corresponding to the de-convoluted lifetime values. After irradiation, the observed average lifetime of positron τavg = 263 ps at room temperature is higher than the bulk lifetime by 21 ps which reveals the presence of radiation-induced defects in the material. A decrease in τavg occurs during room temperature 25∘C to 200∘C indicating the dissociation of higher order defects, might be due to positron trapping in acceptor-type of defects (VIn). A reverse annealing stage is found at temperature range of 250∘C-425∘C for S-parameter probably due to the migration of vacancies and the formation of vacancy clusters. Increase in R-parameter from 325∘C to 425∘C indicates the change in the nature of predominant positron trapping sites. Beyond 425∘C, τavg, S-parameter and R-parameter starts decreasing and around 650∘C, τavg and S-parameter approached almost the bulk value showing the annealing out of radiation-induced defects.

  19. Wash room, bunkhouse, first floor interior. This room is a ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Wash room, bunkhouse, first floor interior. This room is a screened porch with the original sinks extant. Light and ventilation was borrowed from the wash room into the toilets and bathing rooms. - Sespe Ranch, Bunkhouse, 2896 Telegraph Road, Fillmore, Ventura County, CA

  20. Staff corridor (room 206, representing rooms 301, 305, 401, 405, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Staff corridor (room 206, representing rooms 301, 305, 401, 405, 501, and 505), looking south towards the staff corridor vestibule (room 206A, representing rooms 305A, 405A, and 505A). - California State Office Building No. 1, 915 Capitol Mall, Sacramento, Sacramento County, CA

  1. Li + grafting of ion irradiated polyethylene

    NASA Astrophysics Data System (ADS)

    Švorčík, V.; Rybka, V.; Vacík, J.; Hnatowicz, V.; Öchsner, R.; Ryssel, H.

    1999-02-01

    Foils of oriented polyethylene (PE) were irradiated with 63 keV Ar + and 155 keV Xe + ions to different fluences at room temperature and then doped from water solution of LiCl. The as irradiated and irradiated plus doped samples were examined by IR, EPR and neutron depth profiling (NDP) technique. The sheet resistance was also measured by the standard two points method. After Li salt doping of ion modified layer of PE, a reaction between degraded macromolecules and Li occur and thus a new chemical structure C-Li + is formed. Owing to the presence of these cations on the polymer chain, the irradiated plus doped layer exhibits higher electric conductivity compared to as-irradiated ones.

  2. Reactor Neutrino Spectra

    NASA Astrophysics Data System (ADS)

    Hayes, Anna C.; Vogel, Petr

    2016-10-01

    We present a review of the antineutrino spectra emitted from reactors. Knowledge of these spectra and their associated uncertainties is crucial for neutrino oscillation studies. The spectra used to date have been determined either by converting measured electron spectra to antineutrino spectra or by summing over all of the thousands of transitions that make up the spectra, using modern databases as input. The uncertainties in the subdominant corrections to β-decay plague both methods, and we provide estimates of these uncertainties. Improving on current knowledge of the antineutrino spectra from reactors will require new experiments. Such experiments would also address the so-called reactor neutrino anomaly and the possible origin of the shoulder observed in the antineutrino spectra measured in recent high-statistics reactor neutrino experiments.

  3. Stochastic annealing simulation of copper under neutron irradiation

    SciTech Connect

    Heinisch, H.L.; Singh, B.N.

    1998-03-01

    This report is a summary of a presentation made at ICFRM-8 on computer simulations of defect accumulation during irradiation of copper to low doses at room temperature. The simulation results are in good agreement with experimental data on defect cluster densities in copper irradiated in RTNS-II.

  4. Effects of irradiation at low temperature on V-4Cr-4Ti

    SciTech Connect

    Alexander, D.J.; Snead, L.L.; Zinkle, S.J.

    1996-10-01

    Irradiation at low temperatures (100 to 275{degrees}C) to 0.5 dpa causes significant embrittlement and changes in the subsequent room temperature tensile properties of V-4Cr-4Ti. The yield strength and microhardness at room temperature increase with increasing irradiation temperature. The tensile flow properties at room temperature show large increases in strength and a complete loss of work hardening capacity with no uniform ductility. Embrittlement, as measured by an increase in the ductile-to-brittle transition temperature, increases with increasing irradiation temperature, at least up to 275{degrees}C. This embrittlement is not due to pickup of O or other interstitial solutes during the irradiation.

  5. SPECTRA. September 2011

    DTIC Science & Technology

    2011-09-01

    CME. 1982 The first of five Space Shuttle flights of NRL’s Solar Ultraviolet Spectral Irradiance Monitor (SUSIM) which measured absolute...solar UV irradiance and examined the impact of solar vari- ability on the Earth’s ionosphere and climate. SUSIM also flew on the Upper Atmosphere...Research Satellite (UARS) (1991–2005) and produced the longest continuous absolute measurement of solar UV irradiance to date. 1983 Launch of Living

  6. Electron spin resonance study of γ-irradiated Anatolian chickpea (Cicer arietinum L.)

    NASA Astrophysics Data System (ADS)

    Ayda, Canan; Engin, B. I. R. O. L.; Polat, Mustafa; Aydin, Talat

    In this study, an electron spin resonance (ESR) investigation on γ-irradiated chickpea cultivated in Turkey is reported in detail. ESR spectra of unirradiated (control) chickpea were composed of an equally spaced sextet originating from the presence of Mn2+ ions and a single weak resonance signal both centered at gD2.0054±0.0006. Although irradiation was found to have no effect on the Mn2+ signals, it caused a noteworthy increase in free radical signal intensity of chickpea in the studied dose range of (0.1-4.5 kGy). In addition, the ESR spectrum of irradiated chickpea recorded at low scan range (10 mT) showed that there were more than one radical species, having different spectral features, contributing to the central resonance signal. From this point of view, we focussed on the free radical signal in the present study. The area under the ESR absorption curve which is related to the free radical concentration was determined from the experimental spectra recorded throughout the study, and its variation with microwave power, radiation dose, storage time and temperature was investigated in detail. Free radical concentration was observed to decay very fast within the first 15 days after the irradiation cessation and little thereafter. At the end of the storage period (60 days), the free radical concentration is still higher than that of the control (unirradiated) sample. The decay of free radical concentration at room and high temperatures were described well by the sum of three second-order decay functions representing three different radical species (A, B and C). The activation energies of these radicals, evaluated by Arrhenius analysis, are in the order EC>EB>EA. Simulation calculations have shown that three radical species (A, B and C) of different spectral parameters were found to best explain the experimental values.

  7. ESR detection procedure of irradiated papaya containing high water content

    NASA Astrophysics Data System (ADS)

    Kikuchi, Masahiro; Shimoyama, Yuhei; Ukai, Mitsuko; Kobayashi, Yasuhiko

    2011-05-01

    ESR signals were recorded from irradiated papaya at liquid nitrogen temperature (77 K), and freeze-dried irradiated papaya at room temperature (295 K). Two side peaks from the flesh at the liquid nitrogen temperature indicated a linear dose response for 3-14 days after the γ-irradiation. The line shapes recorded from the freeze-dried specimens were sharper than those at liquid nitrogen temperature.

  8. Thermal effects in IR-laser-irradiated living cells

    NASA Astrophysics Data System (ADS)

    Meier, Thomas H.; Rueck, Angelika C.; Scalfi-Happ, Claudia; Hug, Hubert; Schneider, Marion E.

    2003-10-01

    Irradiation of cell-layers with focussed 2.8 μm ir-laser allows to control the cell temperature from room temperature up to 100°C. Temperatures were calculated for a cell culture model and verified experimentally by thermal mapping of the cell-surrounding medium by means of thermochromic liquid crystals (TLC). Irradiation power and time were varied and associated biological effects like necrosis and apoptosis were observed with respect to the irradiation dosis.

  9. Neutron Spectrum Measurements from Irradiations at NCERC

    SciTech Connect

    Jackman, Kevin Richard; Mosby, Michelle A.; Bredeweg, Todd Allen; Hutchens, Gregory Joe; White, Morgan Curtis

    2015-04-15

    Several irradiations have been conducted on assemblies (COMET/ZEUS and Flattop) at the National Criticality Experiments Research Center (NCERC) located at the Nevada National Security Site (NNSS). Configurations of the assemblies and irradiated materials changed between experiments. Different metallic foils were analyzed using the radioactivation method by gamma-ray spectrometry to understand/characterize the neutron spectra. Results of MCNP calculations are shown. It was concluded that MCNP simulated spectra agree with experimental measurements, with the caveats that some data are limited by statistics at low-energies and some activation foils have low activities.

  10. An electron spin resonance study of gamma-irradiated citrus fruits

    NASA Astrophysics Data System (ADS)

    Tabner, Brian J.; Tabner, Vivienne A.

    1993-03-01

    The ESR spectra of the stalks and skins of a selection of unirradiated and γ-irradiated citrus fruits have been obtained. The spectra from the stalks and skins of unirradiated fruits exhibit only a single line, the intensity of which varies markedly from fruit to fruit. The spectra from irradiated stalks exhibit extra features which can be used to detect irradiation, particularly at higher doses. The spectra obtained from the skins of the irradiated fruits also exhibit radiation-induced features which can easily be used to detect irradiation even at the lowest dose examined (2 kGy). The spectra from the irradiated skins show a high degree of reproducibility from fruit to fruit. These observations suggest that ESR spectroscopy could form the basis of a viable test to determine the radiation history of these fruits.

  11. Calculation of conversion coefficients for air kerma to ambient dose equivalent using transmitted spectra of megavoltage X-rays through concrete.

    PubMed

    Cordeiro, T P V; Silva, A X

    2012-12-01

    With the fast advancement of technology, (60)Co teletherapy units are largely being replaced with medical linear accelerators. In most cases, the linear accelerator tends to be installed in the same room in which the (60)Co teletherapy unit was previously placed. If in-depth structural remodelling is out of the question, high-density concrete is usually used to improve shielding against primary, scatter and leakage radiation originating in the new equipment. This work presents a study based on Monte Carlo simulations of the transmission of some clinical photon spectra (from 6, 10, 15, 18 and 25 MV accelerators) through concrete, considering two different densities. Concrete walls with thickness ranging from 0.70 to 2.0 m were irradiated with 30 cm×30 cm primary beam spectra. The results show that the thickness of the barrier decreases up to ∼65 % when barite (high-density concrete) is used instead of ordinary concrete. The average energies of primary and transmitted beam spectra were also calculated. In addition, conversion coefficients from air kerma to ambient dose equivalent, H*(d)/K(air), and air kerma to effective dose, E/K(air), for photon spectra from the transmitted spectra were calculated and compared. The results suggest that the 10-mm depth is not the best choice to represent the effective dose.

  12. Computer Room Fire Protection.

    ERIC Educational Resources Information Center

    Price, Bennett J.

    1990-01-01

    Notes that economic and service factors may dictate that special fire protection measures be given to computer rooms. The discussion covers emergency planning, various types of fire detection and suppression systems, and future options, with particular attention to halon and possible halon replacements. A list of suggested readings is provided.…

  13. Romper Room: An Analysis.

    ERIC Educational Resources Information Center

    Barcus, F. Earle

    Video-tape recordings of the Romper Room program carried by TV station WEMT, Bangor, Maine were examined in an attempt to classify and describe various program elements. Tapes were monitored to obtain descriptions of program activities and to focus on some of the commercial announcements. For the total week studied, more than one-third (36%) of…

  14. Visiting Room 501

    ERIC Educational Resources Information Center

    Curwen, Margaret Sauceda

    2009-01-01

    Students in Room 501 were exploring and negotiating their lives as transnational citizens. In a globalized world of instantaneous information and communication, Latino students are shaping, morphing, and evolving into a new generation. This study highlights one group of students who were aspiring toward middle class, which is not the typical…

  15. Locker-Room Talk.

    ERIC Educational Resources Information Center

    Lowe, Jason; Noyes, Brad

    1999-01-01

    Explains how proper athletic facility locker-room design can save time and money. Design factors that address who will be using the facility are discussed as are user requirements, such as preparation areas, total storage area per user, grooming area, and security areas. Final comments address maintenance and operations issues. (GR)

  16. Technology Equipment Rooms.

    ERIC Educational Resources Information Center

    Day, C. William

    2001-01-01

    Examines telecommunications equipment room design features that allow for growth and can accommodate numerous equipment replacements and upgrades with minimal service disruption and with minimal cost. Considerations involving the central hub, power and lighting needs, air conditioning, and fire protection are discussed. (GR)

  17. Rooms with a View

    ERIC Educational Resources Information Center

    Hourihan, Peter; Berry, Millard, III

    2006-01-01

    When well-designed and integrated into a campus living or learning space, an atrium can function as the heart and spirit of a building, connecting interior rooms and public spaces with the outside environment. However, schools and universities should seek technological and HVAC solutions that maximize energy efficiency. This article discusses how…

  18. Rooms with a View

    ERIC Educational Resources Information Center

    Hourihan, Peter; Berry, Millard, III

    2006-01-01

    When well-designed and integrated into a campus living or learning space, an atrium can function as the heart and spirit of a building, connecting interior rooms and public spaces with the outside environment. However, schools and universities should seek technological and HVAC solutions that maximize energy efficiency. This article discusses how…

  19. Technology Equipment Rooms.

    ERIC Educational Resources Information Center

    Day, C. William

    2001-01-01

    Examines telecommunications equipment room design features that allow for growth and can accommodate numerous equipment replacements and upgrades with minimal service disruption and with minimal cost. Considerations involving the central hub, power and lighting needs, air conditioning, and fire protection are discussed. (GR)

  20. Infrared spectroscopy study of irradiated PVDF

    SciTech Connect

    Chappa, Veronica; Grosso, Mariela del; Garcia Bermudez, Gerardo; Behar, Moni

    2007-10-26

    The effects induced by 1 MeV/amu ion irradiations were compared to those induced by 4-12 MeV/amu irradiations. Structural analysis with infrared spectroscopy (FTIR) was carried out on PVDF irradiated using C and He beams with different fluences. From these spectra it was observed, as a function of fluence, an overall destruction of the polymer, amorphization of the crystalline regions and the creation of in-chain unsaturations. The track dimensions were determined using a previously developed Monte Carlo simulation code and these results were compared to a semiempirical model.

  1. Effect of irradiation on crystallinity and mechanical properties of ultrahigh molecular weight polyethylene

    SciTech Connect

    Zhao, Yong; Luo, Yunxia; Jiang, Bingzheng . Changchun Inst. of Applied Chemistry)

    1993-12-10

    Ultrahigh molecular weight polyethylene (UHMWPE) has been irradiated (0--40 Mrad) with a Co[sup 60] source at room temperature under vacuum. The crystallinity has been investigated by differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS). The mechanical properties have been determined at room temperature. A significant increase of heat of fusion can be seen at low irradiation doses, which is attributed to crystallization, caused by chain scission during the process of irradiation. It is also observed that the thickness of the lamellae changes with irradiation dose. The Young's modulus has been improved significantly after irradiation at low doses.

  2. Microstructure evolution during helium irradiation and post-irradiation annealing in a nanostructured reduced activation steel

    NASA Astrophysics Data System (ADS)

    Liu, W. B.; Ji, Y. Z.; Tan, P. K.; Zhang, C.; He, C. H.; Yang, Z. G.

    2016-10-01

    Severe plastic deformation, intense single-beam He-ion irradiation and post-irradiation annealing were performed on a nanostructured reduced activation ferritic/martensitic (RAFM) steel to investigate the effect of grain boundaries (GBs) on its microstructure evolution during these processes. A surface layer with a depth-dependent nanocrystalline (NC) microstructure was prepared in the RAFM steel using surface mechanical attrition treatment (SMAT). Microstructure evolution after helium (He) irradiation (24.8 dpa) at room temperature and after post-irradiation annealing was investigated using Transmission Electron Microscopy (TEM). Experimental observation shows that GBs play an important role during both the irradiation and the post-irradiation annealing process. He bubbles are preferentially trapped at GBs/interfaces during irradiation and cavities with large sizes are also preferentially trapped at GBs/interfaces during post-irradiation annealing, but void denuded zones (VDZs) near GBs could not be unambiguously observed. Compared with cavities at GBs and within larger grains, cavities with smaller size and higher density are found in smaller grains. The average size of cavities increases rapidly with the increase of time during post-irradiation annealing at 823 K. Cavities with a large size are observed just after annealing for 5 min, although many of the cavities with small sizes also exist after annealing for 240 min. The potential mechanism of cavity growth behavior during post-irradiation annealing is also discussed.

  3. Effect of electron beam irradiation on the microstructure, optical and electrical properties of glass resistive plate chamber detector material

    NASA Astrophysics Data System (ADS)

    Aneeshkumar, K. V.; Krishnaveni, S.; Ranganathaiah, C.; Ravikumar, H. B.

    2017-08-01

    The glass resistive plate chamber (RPC) detector materials were exposed to 8 MeV electron beam from 20 to 100 kGy in steps of 20 kGy. In order to study the electron beam irradiation-induced effects in glass RPC detector material, positron annihilation lifetime spectroscopy (PALS), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopic investigations were carried out. PALS analysis at lower electron doses indicates the increased void size with the creation of additional sites in the glass network. This is attributed to the breakage of Si-O bonds at the regular tetrahedral sites of Si-O-Si up to 40 kGy. The reduced void size at higher irradiation doses indicates the increased chemical bonding between the tetrahedral sites of Si-O-Si and hence increases the short-range order in the silica glass. These changes are complement with the XRD, FTIR results and the measured electrical conductivity. The variation of AC conductivity with frequency obeys Jonscher power law in all the electron irradiation doses at room temperature. The variation in optical band gap energy from the ultraviolet-visible (UV-Vis) spectra inferred the elimination of defects accumulation at higher irradiation doses due to the glass network close packing.

  4. ESR and TL studies of irradiated Anatolian laurel leaf (Laurus nobilis L.)

    NASA Astrophysics Data System (ADS)

    Tepe Çam, Semra; Aydaş, Canan; Engin, Birol; Rabia Yüce, Ülkü; Aydın, Talat; Polat, Mustafa

    2012-06-01

    Laurel leaf (Laurus nobilis L.) samples that originated from Turkey were analyzed by electron spin resonance (ESR) and thermoluminescence (TL) techniques before and after γ-irradiation. Unirradiated (control) laurel leaf samples exhibit a weak ESR singlet centered at g=2.0020. Besides this central signal were two weak satellite signals situated about 3 mT left and right to it in radiation-induced spectra. The dose-response curve of the radiation-induced ESR signal at g=2.0187 (the left satellite signal) was found to be described well by a power function. Variation of the left satellite ESR signal intensity of irradiated samples at room temperature with time in a long term showed that cellulosic free radicals responsible for the ESR spectrum of laurel leaves were not stable but detectable even after 100 days. Annealing studies at four different temperatures were used to determine the kinetic behavior and activation energy of the radiation-induced cellulosic free radicals responsible from the left satellite signal (g=2.0187) in laurel leaves. TL measurements of the polymineral dust isolated from the laurel leaf samples allowed distinguishing between irradiated and unirradiated samples.

  5. Room-temperature effects of UV radiation in KBr:? crystals

    NASA Astrophysics Data System (ADS)

    Pérez-Salas, R.; Meléndrez, R.; Aceves, R.; Rodriguez, R.; Barboza-Flores, M.

    1996-07-01

    Thermoluminescence and optical absorption measurements have been carried out in KBr:0953-8984/8/27/009/img9 crystals irradiated with monochromatic UV light (200 - 300 nm) and x-rays at room temperature. For UV- and x-irradiated crystals strong similarities between the thermoluminescence glow curves have been found, suggesting that the low-energy UV radiation produces the same defects as produced by x-irradiation in this material. The thermoluminescence glow curves are composed of six glow peaks located at 337, 383, 403, 435, 475 and 509 K. Thermal annealing experiments in previously irradiated crystals show clearly a correlation between the glow peak located at 383 K and the F-centre thermal bleaching process. Also, the excitation spectrum for each thermoluminescence glow peak has been investigated, showing that the low-energy radiation induces the formation of F centres.

  6. Optical waveguide properties of Ca0.4Ba0.6Nb2O6 crystal formed by oxygen ion irradiation

    NASA Astrophysics Data System (ADS)

    Wang, Tie-Jun; Zhou, Yu-Fan; Yu, Xiao-Fei; Liu, Tao; Zhang, Lian; Song, Hong-Lian; Qiao, Mei; Wang, Xue-Lin

    2015-07-01

    We report the fabrication of a planar optical waveguide in a Ca0.4Ba0.6Nb2O6 crystal by irradiation with 6.0 MeV oxygen ions. We measured the guiding mode by the prism-coupling method at 633 nm and 1539 nm. The near-field intensity distributions were measured by the end-face coupling setup at a wavelength of 633 nm. The reflectivity calculation method (RCM) was used for reconstructing refractive index profiles. SRIM was used to simulate the electronic and nuclear stopping power caused by oxygen ion irradiation, and the finite-difference beam propagation method (FD-BPM) was used to simulate the near-field intensity distributions. Micro-Raman spectra were measured at room temperature in air to study the differences between the substrate and waveguide region.

  7. The local environment of Cr3+ impurities in normal and x-rays irradiated carbon doped ruby: An electron paramagnetic resonance (EPR) study

    NASA Astrophysics Data System (ADS)

    Kazan, S.; Açıkgöz, M.; Yalçın, O.

    2015-01-01

    Local environment of substitutional paramagnetic point defect (impurity) in normal and x-ray irradiated commercially available α-Al2O3:C samples (commercial product of Landauer, Inc.) has been studied by using the electron paramagnetic resonance (EPR) technique at room temperature. In both samples the EPR spectra showed strongly angular dependent behavior. The zero-field splitting (ZFS) parameters (ZFSPs) have been determined for substitutional Cr3+ centers. The observed additional EPR signals for x-ray irradiated sample were attributed to another center with different spin Hamiltonian (SH) parameters. In addition to the experimental findings, the ZFSPs and the local structure of the Cr3+ ions were theoretically determined using superposition model (SPM) calculations.

  8. Metallic Li colloids studied by Li-7 MAS NMR in electron-irradiated LiF

    NASA Astrophysics Data System (ADS)

    Zogal, O. J.; Beuneu, F.; Vajda, P.; Florian, P.; Massiot, D.

    Li-7 MAS NMR spectra of 2.5 MeV electron-irradiated LiF crystals have been measured in a field of 9.4 T. Besides the resonance line of the ionic compound, a second well-separated spectrum is observed in the region of the Knight shift value for metallic lithium. At room temperature, the latter can be decomposed into two components with different Knight shift and linewidth values. When the temperature is increased, line narrowing takes place at first, indicating shortening of correlation times for self-diffusion, independently in both components. Above 370 K, both lines broaden and approach each other before collapsing into a single line. The high ppm component disappears after crossing the melting temperature of metallic lithium (454 K). The two lines are attributed to different types of metallic Li: one to bulk-like metal, the other to Li present initially under pressure and relaxing to the former under thermal treatment.

  9. ENDOR and ESR studies of a stable radical in irradiated cytidine

    NASA Technical Reports Server (NTRS)

    Allison, D. L.; Alexander, C., Jr.

    1974-01-01

    A model is proposed for a stable radical species formed by X-irradiation in a single crystal of cytidine and studied by electron nuclear double resonance (ENDOR) and electron spin resonance (ESR) techniques at room temperature. ENDOR and ESR spectra are analyzed to obtain the principal values of the spectroscopic splitting factor and the spectroscopic and hyperfine splitting tensors. The results show hyperfine coupling of an unpaired electron to one hydrogen nucleus and two slightly different geometric forms of the radical with small differences in hyperfine couplings. It is proposed that this radical is formed in the ribose sugar group with a hydrogen atom in a beta position coupling with respect to a carbon-centered unpaired electron and a spin density of approximately 0.2 on a carbon atom.

  10. STS-127 Firing Room

    NASA Image and Video Library

    2009-07-11

    NASA mission managers watch the latest weather radar on a monitor in Firing Room Four of the Launch Control Center at NASA's Kennedy Space Center in Cape Canaveral, Florida, Sunday, July 12, 2009. Endeavour is set to launch at 7:13p.m. EDT with the crew of STS-127 and start a 16-day mission that will feature five spacewalks and complete construction of the Japan Aerospace Exploration Agency's Kibo laboratory. Photo Credit: (NASA/Bill Ingalls)

  11. STS-127 Firing Room

    NASA Image and Video Library

    2009-07-11

    NASA Associate Administrator for Space Operations William Gerstenmaier watches the latest weather radar from Firing Room Four of the Launch Control Center at NASA's Kennedy Space Center in Cape Canaveral, Florida, Sunday, July 12, 2009. Endeavour is set to launch at 7:13p.m. EDT with the crew of STS-127 and start a 16-day mission that will feature five spacewalks and complete construction of the Japan Aerospace Exploration Agency's Kibo laboratory. Photo Credit: (NASA/Bill Ingalls)

  12. STS-127 Firing Room

    NASA Image and Video Library

    2009-07-11

    John P. Shannon, Manager, NASA Space Shuttle Program Office watches the latest weather radar in Firing Room Four of the Launch Control Center at NASA's Kennedy Space Center in Cape Canaveral, Florida, Sunday, July 12, 2009. Endeavour is set to launch at 7:13p.m. EDT with the crew of STS-127 and start a 16-day mission that will feature five spacewalks and complete construction of the Japan Aerospace Exploration Agency's Kibo laboratory. Photo Credit: (NASA/Bill Ingalls)

  13. STS-127 Firing Room

    NASA Image and Video Library

    2009-07-11

    NASA Shuttle Launch Director Michael Leinbach talks on the phone from Firing Room Four of the Launch Control Center at NASA's Kennedy Space Center in Cape Canaveral, Florida, Sunday, July 12, 2009. THe space shuttle Endeavour is set to launch at 7:13p.m. EDT with the crew of STS-127 and start a 16-day mission that will feature five spacewalks and complete construction of the Japan Aerospace Exploration Agency's Kibo laboratory. Photo Credit: (NASA/Bill Ingalls)

  14. Clean room wiping cloths

    SciTech Connect

    Harding, W.B.

    1981-01-01

    The suitability of various fabrics for use as clean room wiping cloths was investigated. These fabrics included knit polyester, knit nylon, urethane foam, woven cotton, nonwoven polyester, nonwoven rayon, nonwoven polyethylene and polypropylene, and woven nylon. These materials were tested for detachable lint and fibers, deterioration, and oil content which could leave contaminating films on wiped surfaces. Well-laundered nylon and polyester cloths knitted from filamentary yarn, with hems, were found to be suitable. (LCL)

  15. MACHINE ROOM FROM DOORWAY TO COMMUNICATIONS ROOM, VIEW FACING SOUTHWEST. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    MACHINE ROOM FROM DOORWAY TO COMMUNICATIONS ROOM, VIEW FACING SOUTHWEST. - Naval Air Station Barbers Point, World War II Command Center, Midway Street east of Lexington Avenue, Ewa, Honolulu County, HI

  16. DETAIL VIEW OF OPERATIONS MANAGEMENT ROOM, FIRING ROOM NO. 4, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL VIEW OF OPERATIONS MANAGEMENT ROOM, FIRING ROOM NO. 4, FACING WEST - Cape Canaveral Air Force Station, Launch Complex 39, Launch Control Center, LCC Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  17. DETAIL VIEW OF OPERATIONS MANAGEMENT ROOM, FIRING ROOM NO. 3, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL VIEW OF OPERATIONS MANAGEMENT ROOM, FIRING ROOM NO. 3, FACING EAST - Cape Canaveral Air Force Station, Launch Complex 39, Launch Control Center, LCC Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  18. DETAIL VIEW OF OPERATIONS MANAGEMENT ROOM, FIRING ROOM NO. 3, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL VIEW OF OPERATIONS MANAGEMENT ROOM, FIRING ROOM NO. 3, FACING SOUTHEAST - Cape Canaveral Air Force Station, Launch Complex 39, Launch Control Center, LCC Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  19. DETAIL VIEW OF OPERATIONS MANAGEMENT ROOM, FIRING ROOM NO. 3, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL VIEW OF OPERATIONS MANAGEMENT ROOM, FIRING ROOM NO. 3, FACING NORTH - Cape Canaveral Air Force Station, Launch Complex 39, Launch Control Center, LCC Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  20. INTERIOR VIEW OF A TYPICAL ROOM (ROOM NO. 209), FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW OF A TYPICAL ROOM (ROOM NO. 209), FACING NORTH. THE SINK AND MIRROR MAY HAVE BEEN FROM THE ORIGINAL CONSTRUCTION. - U.S. Naval Base, Pearl Harbor, Bachelor Officer Quarters, Dealy Circle, Pearl City, Honolulu County, HI

  1. Interior of Room 163, looking northwest in Generator Room ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior of Room 163, looking northwest in Generator Room - Over-the-Horizon Backscatter Radar Network, Bangor Air National Guard Base Operations Building, At the end of Maine Road, Bangor, Penobscot County, ME

  2. Interior of Room 127, looking southsoutheast in Display Controller's Room ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior of Room 127, looking south-southeast in Display Controller's Room - Over-the-Horizon Backscatter Radar Network, Bangor Air National Guard Base Operations Building, At the end of Maine Road, Bangor, Penobscot County, ME

  3. Interior of Room T120, looking northnortheast at pump room ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior of Room T120, looking north-northeast at pump room - Over-the-Horizon Backscatter Radar Network, Moscow Radar Site Transmit Sector One Transmitter Building, At the end of Steam Road, Moscow, Somerset County, ME

  4. Interior of Room 126, looking southsoutheast in Tactical Operations Room ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior of Room 126, looking south-southeast in Tactical Operations Room - Over-the-Horizon Backscatter Radar Network, Bangor Air National Guard Base Operations Building, At the end of Maine Road, Bangor, Penobscot County, ME

  5. View from window of southeast room (bed room no. 1), ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View from window of southeast room (bed room no. 1), second floor, commandant's house, looking east across parade ground. - Fort Simcoe, Commandant's House & Blockhouse, Fort Simcoe Road, White Swan, Yakima County, WA

  6. 8. GROUND FLOOR, NORTH ROOM, NORTH WALL, VIEW OF ROOM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. GROUND FLOOR, NORTH ROOM, NORTH WALL, VIEW OF ROOM LOOKING TOWARDS FIREPLACE, SHOWING PROJECTING CHIMNEY, WINDOW EMBRASURES ON EITHER SIDE AND PANELING - Ocean Hall, Bushwood, St. Mary's County, MD

  7. 21. Perimeter acquisition radar building room #200, electrical equipment room ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. Perimeter acquisition radar building room #200, electrical equipment room - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

  8. 24. Perimeter acquisition radar building room #203, communications room ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. Perimeter acquisition radar building room #203, communications room - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

  9. 34. Perimeter acquisition radar building room #325, tape handler room ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    34. Perimeter acquisition radar building room #325, tape handler room - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

  10. 23. Perimeter acquisition radar building room #202, mechanical equipment room ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. Perimeter acquisition radar building room #202, mechanical equipment room no. 2 - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

  11. Supreme Court Room (room 573), looking westsouthwest (bearing 250). Not ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Supreme Court Room (room 573), looking west-southwest (bearing 250). Not that missing scones are to be returned and presently obscured ceiling is proposed for restoration. - California State Library & Courts Building, 914 Capitol Mall, Sacramento, Sacramento County, CA

  12. 7. October 1969 SOUTHWEST ROOM, FIRST FLOOR, 'CAPTAINS' ROOM' (Note: ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. October 1969 SOUTHWEST ROOM, FIRST FLOOR, 'CAPTAINS' ROOM' (Note: Furnace has replaced pot-bellied stove, cribbage board on table) - William Rotch Warehouse, Main & South Water Streets, Nantucket, Nantucket County, MA

  13. FACILITY 713, DINING ROOM WITH LIVING ROOM IN LEFT BACKGROUND, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FACILITY 713, DINING ROOM WITH LIVING ROOM IN LEFT BACKGROUND, VIEW FACING EAST. - Schofield Barracks Military Reservation, Central-Entry Single-Family Housing Type, Between Bragg & Grime Streets near Ayres Avenue, Wahiawa, Honolulu County, HI

  14. FACILITY 728, LIVING ROOM FROM DINING ROOM, OBLIQUE VIEW FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FACILITY 728, LIVING ROOM FROM DINING ROOM, OBLIQUE VIEW FACING SOUTH. - Schofield Barracks Military Reservation, Corner-Entry Single-Family Housing Type, Between Bragg & Grime Streets near Williston Avenue, Wahiawa, Honolulu County, HI

  15. FACILITY 809, DINING ROOM WITH LIVING ROOM ON RIGHT, VIEW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FACILITY 809, DINING ROOM WITH LIVING ROOM ON RIGHT, VIEW FACING NORTH-NORTHWEST. - Schofield Barracks Military Reservation, Corner-Entry Single-Family Housing Type, Between Hamilton & Tidball Streets, & between Williston & Ayres Avenues, Wahiawa, Honolulu County, HI

  16. 8. VIEW OF ROOM 101 (ASSEMBLY ROOM) FROM NORTHEAST CORNER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. VIEW OF ROOM 101 (ASSEMBLY ROOM) FROM NORTHEAST CORNER SHOWING FLEXIBLE AIR-CONDITIONING DUCT - Vandenberg Air Force Base, Space Launch Complex 3, Vehicle Support Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  17. Interior view, representative groundfloor resident room, looking west. The room ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior view, representative ground-floor resident room, looking west. The room is located on the west side of the south wing. - U. S. Naval Asylum, Biddle Hall, Gray's Ferry Avenue, Philadelphia, Philadelphia County, PA

  18. 175. STORAGE ROOM, SOUTH WALL OF STORAGE ROOM, ADDED WITH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    175. STORAGE ROOM, SOUTH WALL OF STORAGE ROOM, ADDED WITH ELEVATOR ADDITION OF 1905. WALL IS EXTERIOR OF ORIGINAL WAGON WORKS OF 1883. - Gruber Wagon Works, Pennsylvania Route 183 & State Hill Road at Red Bridge Park, Bernville, Berks County, PA

  19. 44. Launch Control Equipment Room, taken from rear of room. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    44. Launch Control Equipment Room, taken from rear of room. Lyon - Whiteman Air Force Base, Oscar O-1 Minuteman Missile Alert Facility, Southeast corner of Twelfth & Vendenberg Avenues, Knob Noster, Johnson County, MO

  20. 42. Launch Control Equipment Room, rear of room. Lyon ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    42. Launch Control Equipment Room, rear of room. Lyon - Whiteman Air Force Base, Oscar O-1 Minuteman Missile Alert Facility, Southeast corner of Twelfth & Vendenberg Avenues, Knob Noster, Johnson County, MO

  1. 8. CONTROL AND EQUIPMENT ROOM INTERIOR. MECHANICAL EQUIPMENT ROOM AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. CONTROL AND EQUIPMENT ROOM INTERIOR. MECHANICAL EQUIPMENT ROOM AT RIGHT AND ENTRANCE AT LEFT. Looking east. - Edwards Air Force Base, South Base Sled Track, Firing Control Blockhouse, South of Sled Track at east end, Lancaster, Los Angeles County, CA

  2. Interior. Storage room for glassware and reference room with frequentlyused ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior. Storage room for glassware and reference room with frequently-used chemistry and chemical engineering texts. - Thomas A. Edison Laboratories, Building No. 2, Main Street & Lakeside Avenue, West Orange, Essex County, NJ

  3. 12. "TAPE ROOM" LOCATED AT SOUTHEAST CORNER OF MAIN ROOM. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. "TAPE ROOM" LOCATED AT SOUTHEAST CORNER OF MAIN ROOM. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Instrumentation & Control Building, Test Area 1-115, northwest end of Saturn Boulevard, Boron, Kern County, CA

  4. Console Room, looking southwesterly into Highbay Generator Room Beale ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Console Room, looking southwesterly into Highbay Generator Room - Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Power Plant, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  5. [Virtual room of gastroenterology].

    PubMed

    Spinelli, Osvaldo Mateo; Fittipaldi, Mónica Elsa; Henderson, Eduardo; Krabshuis, Justus Hendrik

    2010-12-01

    The amount of published information and its continuing growth can no longer be managed by an individual searcher. One of today's great challenges for the academic researcher and clinician is to find a relevant scientific article using bibliographic search strategies. We aimed to design and build a Virtual Room of Gastroenterology (VRG) generating real-time automated search strategies and producing bibliographic and full text search results. These results update and complement with the latest evidence the Clinical Guideline Program of the World Gastroenterology Organisation. The HTML driven interface provides a series of pre-formulated MeSH based search strategies for each Aula. For each topic between 10 and 20 specific terms, qualifiers and subheadings are identified. The functionality of the VRG is based on the PubMed's characteristic that allows a search strategy to be captured as a web address. The VRG is available in Spanish and English, and the access is free. There are 28 rooms currently available. All together these rooms provide an advanced bibliographic access using more than 900 pre-programmed MeSH driven strategies. In a further very recent development some of the topics of VRG now allow cascade based searches. These searches look at resource sensitive options and possible ethnic difference per topic. The VRG allows significant reductions in time required to design and carry out complex bibliographic searches in the areas of gastroenterology, hepatology and endoscopy. The system updates automatically in real-time thus ensuring the currency of the results.

  6. Photographic spectra of fireballs

    NASA Astrophysics Data System (ADS)

    Borovička, J.

    2016-01-01

    Two methods of spectroscopy of meteors using image intensified video cameras and classical photographic film cameras are compared. Video cameras provide large number of low resolution spectra of meteors of normal brightness, which can be used for statistical studies. Large format film cameras have been used through the history and provide high resolution spectra, which can be used to derive temperature, density and absolute abundances of various elements in the radiating plasma. The sensitivity of films is, however, low and only spectra of bright meteors (fireballs) can be studied. Examples of photographic fireball spectra are provided.

  7. Crack spectra analysis

    SciTech Connect

    Tiernan, M.

    1980-09-01

    Crack spectra derived from velocity data have been shown to exhibit systematics which reflect microstructural and textural differences between samples (Warren and Tiernan, 1980). Further research into both properties and information content of crack spectra have yielded the following: Spectral features are reproducible even at low pressures; certain observed spectral features may correspond to non-in-situ crack populations created during sample retrieval; the functional form of a crack spectra may be diagnostic of the sample's grain texture; hysteresis is observed in crack spectra between up and down pressure runs - it may be due to friction between the faces of closed crack populations.

  8. Red photoluminescence of living systems at the room temperature : measurements and results

    NASA Astrophysics Data System (ADS)

    Kudryashova, I. S.; Rud, V. Yu; Shpunt, V. Ch; Rud, Yu V.; Glinushkin, A. P.

    2016-08-01

    Presents results of a study of the red luminescence of living plants at room temperature. The analysis of obtained results allows to conclude that the photoluminescence spectra for green leaves in all cases represent the two closely spaced bands.

  9. Post-irradiation stability of polyvinyl chloride at sterilizing doses

    NASA Astrophysics Data System (ADS)

    Naimian, F.; Katbab, A. A.; Nazokdast, H.

    1994-12-01

    Post-irradiation stability of plasticized PVC irradiated by 60Co gamma ray at sterilizing doses has been studied. Effects of irradiation upon chemical structure, mechanical properties and rheological behaviour of samples contained different amounts of Di(2-ethylhexyl)phthalate as plasticizer have been investigated. Formation of conjugated double bonds, carbonyl and hydroxyl groups have been followed by UV and FTIR spectrometers up to 6 months after irradiation. FTIR spectra of irradiated samples showed no significant changes in carbonyl and hydroxyl groups even 6 months after irradiation. However, changes in UV-visible spectra was observed for the irradiated samples up to 6 months post-irradiation. This has been attributed to the formation of polyenes which leads to the discoloration of this polymer. Despite a certain degree of discoloration, it appears that the mechanical properties of PVC are not affected by irradiation at sterilizing doses. No change in the melt viscosity of the irradiated PVC samples with post-irradiation was observed, which is in consistent with the IR results.

  10. Raman spectroscopy of ion-irradiated astrophysically relevant materials

    NASA Astrophysics Data System (ADS)

    Baratta, G. A.; Brunetto, R.; Leto, G.; Palumbo, M. E.; Spinella, F.; Strazzulla, G.

    Solid objects in space (interstellar grains, comets, interplanetary dust particles, etc.) are continuously exposed to energetic processes, such as cosmic ion irradiation, that influence their evolution. In this paper we present an experimental study, carried out by Raman spectroscopy, of the effects induced by ion irradiation on frozen ices and refractory materials. If the irradiated ice mixture contains a relevant amount of carbon atoms, the ice is converted into an organic residue (stable at room temperature), which at high irradiation dose evolves toward a hydrogenated amorphous carbon. Here we show that material similar to that produced in the laboratory by ion irradiation of frozen ice mixtures and refractory materials can be formed in space by cosmic ion irradiation. This finding has been recently confirmed by the Stardust mission, which revealed in some of the cometary particles collected in space and returned to earth carbonaceous materials that have been processed by cosmic ion irradiation.

  11. Mechanical properties of acellular mouse lungs after sterilization by gamma irradiation.

    PubMed

    Uriarte, Juan J; Nonaka, Paula N; Campillo, Noelia; Palma, Renata K; Melo, Esther; de Oliveira, Luis V F; Navajas, Daniel; Farré, Ramon

    2014-12-01

    Lung bioengineering using decellularized organ scaffolds is a potential alternative for lung transplantation. Clinical application will require donor scaffold sterilization. As gamma-irradiation is a conventional method for sterilizing tissue preparations for clinical application, the aim of this study was to evaluate the effects of lung scaffold sterilization by gamma irradiation on the mechanical properties of the acellular lung when subjected to the artificial ventilation maneuvers typical within bioreactors. Twenty-six mouse lungs were decellularized by a sodium dodecyl sulfate detergent protocol. Eight lungs were used as controls and 18 of them were submitted to a 31kGy gamma irradiation sterilization process (9 kept frozen in dry ice and 9 at room temperature). Mechanical properties of acellular lungs were measured before and after irradiation. Lung resistance (RL) and elastance (EL) were computed by linear regression fitting of recorded signals during mechanical ventilation (tracheal pressure, flow and volume). Static (Est) and dynamic (Edyn) elastances were obtained by the end-inspiratory occlusion method. After irradiation lungs presented higher values of resistance and elastance than before irradiation: RL increased by 41.1% (room temperature irradiation) and 32.8% (frozen irradiation) and EL increased by 41.8% (room temperature irradiation) and 31.8% (frozen irradiation). Similar increases were induced by irradiation in Est and Edyn. Scanning electron microscopy showed slight structural changes after irradiation, particularly those kept frozen. Sterilization by gamma irradiation at a conventional dose to ensure sterilization modifies acellular lung mechanics, with potential implications for lung bioengineering.

  12. Commander's conference room (room 202), closet and hallway to bathroom ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Commander's conference room (room 202), closet and hallway to bathroom and bedroom, leading to conference room 211. Viewing windows look down on the display area. View to north - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  13. 45. 1915 CLOTH ROOM ADJACENT TO PICKER ROOM, SECOND FLOOR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. 1915 CLOTH ROOM ADJACENT TO PICKER ROOM, SECOND FLOOR, NORTH END OF MILL NO. 2, WALL ON LEFT DIVIDING CLOTH ROOM ADDED LATER (PROBABLY C. 1970s). - Prattville Manufacturing Company, Number One, 242 South Court Street, Prattville, Autauga County, AL

  14. Room with a View: Ethical Encounters in Room 13

    ERIC Educational Resources Information Center

    Grube, Vicky

    2012-01-01

    In this article, the author describes ethical encounters in Room 13, a schoolroom where children made what they wanted, posed their own questions, and ran an art room like a small business. In Room 13 children had the responsibility to maintain all aspects of the art studio. Specific decisions fell to an annually elected management team, a small…

  15. INTERIOR, FROM DINIG ROOM TO LIVING ROOM AND FRONT LANAI, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR, FROM DINIG ROOM TO LIVING ROOM AND FRONT LANAI, SHOWING POCKET DOORS BETWEEN LIVING AND DINING ROOMS. VIEW FACING NORTH-NORTHWEST. - U.S. Naval Base, Pearl Harbor, Naval Housing Area Makalapa, Senior Officers' Quarters Type E, 37 Halawa Drive, Pearl City, Honolulu County, HI

  16. Irradiation response on mechanical properties of neutron irradiated F82H

    NASA Astrophysics Data System (ADS)

    Shiba, K.; Suzuki, M.; Hishinuma, A.

    1996-10-01

    Tensile and Charpy impact properties of neutron irradiated F82H (Fe8Cr2WVTa) with and without boron have been investigated to obtain the basic irradiation response on mechanical properties in low damage regime less than 1 dpa at the temperature ranging from 300° to 590°C. Boron-doped steel was used for the helium effect due to (n, α) reaction. Typical irradiation hardening was observed at 300°C. The irradiation above 520°C did not reveal increase in yield stress, but the specimen irradiated at 590°C showed some reduction in elongation in room temperature tensile testing. Slight difference in the tensile properties between boron-doped and boron-free were observed at 590°C. No changes in ductile brittle transition temperature (DBTT) occurred at a temperature between 335° and 460°C by Charpy impact testing.

  17. Analysis of primary damage in silicon carbide under fusion and fission neutron spectra

    NASA Astrophysics Data System (ADS)

    Guo, Daxi; Zang, Hang; Zhang, Peng; Xi, Jianqi; Li, Tao; Ma, Li; He, Chaohui

    2014-12-01

    Irradiation parameters on primary damage states of SiC are evaluated and compared for the first wall of ITER under deuterium-deuterium (DD) and deuterium-tritium (DT) operation, the high temperature gas-cooled reactor (HTGR) and high flux isotope reactor (HFIR). With the same neutron fluence, the studied fusion spectra produce more damage and much higher gas production than the fission spectra. Due to comparable gas production and similar weighted primary recoil spectra, HFIR is considered suitable to simulate the neutron irradiation in an HTGR. In contrast to the significant differences between the weighted primary recoil spectra of the fission and the fusion spectra, the weighted secondary recoil spectra of HFIR and HTGR match those of DD and DT, indicating that displacement cascades by the fission and the fusion irradiation are similar when the damage distribution among damaged regions by secondary recoils is taken into account.

  18. ESR spectroscopic properties of irradiated gum Arabic.

    PubMed

    Leonor, S J; Gómez, J A; Kinoshita, A; Calandreli, I; Tfouni, E; Baffa, O

    2013-12-01

    Electron spin resonance (ESR) spectra of irradiated gum Arabic with doses between 0.5 and 5 kGy were studied. A linear relationship between the absorbed dose and the intensities of the ESR spectra was observed. ESR spectra of irradiated gum Arabic showed a decay of relative concentrations of free radicals originated by radiation and the production of at least two species of free radicals with half-times: 3.3 and 125.4 h. The results of spectral simulations for these radical groups were giso=2.0046; A=1.2 mT and gx=gy=2.0062, gz=2.0025. Hydration and dehydration of irradiated gum Arabic returns the ESR spectrum to its initial state before irradiation. The results show that ESR can be used as simple and reliable method to detect irradiated gum Arabic up to 60 days after initial radiation with doses on the order of 5 kGy. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Thermoluminescence properties of irradiated chickpea and corn

    NASA Astrophysics Data System (ADS)

    Necmeddin Yazici, A.; Bedir, Metin; Bozkurt, Halil; Bozkurt, Hüseyin

    2008-02-01

    A study was carried out to establish a detection method for irradiated chickpea and corn by thermoluminescence (TL) method. The leguminous were packed in polyethylene bags and then the packets were irradiated at room temperature at different doses by 60Co gamma source at 1, 4, 8 and 10 kGy. Minerals extracted from the leguminous were deposited onto a clean aluminum disc and TL intensities of the minerals were measured by TL. It was observed that the extracted samples from both leguminous exhibit good TL Intensity and the TL intensity of glow curves of them increased proportionally to irradiation doses. The TL glow curve of both irradiated leguminous presents a single broad peak below 400 °C. The TL trapping parameters glow peaks were estimated by the additive dose (AD), Tm(Ea)-Tstop and computerized glow curve deconvolution (CGCD) methods. The fading characteristics of glow curves were also recorded up to 6 months.

  20. a Study of Stress Relaxation Rate in Un-Irradiated and Neutron-Irradiated Stainless Steel

    NASA Astrophysics Data System (ADS)

    Ghauri, I. M.; Afzal, Naveed; Zyrek, N. A.

    Stress relaxation rate in un-irradiated and neutron-irradiated 303 stainless steel was investigated at room temperature. The specimens were exposed to 100 mC, Ra-Be neutron source of continuous energy 2-12 MeV for a period ranging from 4 to 16 days. The tensile deformation of the specimens was carried out using a Universal Testing Machine at 300 K. During the deformation, straining was frequently interrupted by arresting the cross head to observe stress relaxation at fixed load. Stress relaxation rate, s, was found to be stress dependent i.e. it increased with increasing stress levels σ0 both in un-irradiated and irradiated specimens, however the rate was lower in irradiated specimens than those of un-irradiated ones. A further decrease in s was observed with increase in exposure time. The experiential decrease in the relaxation rate in irradiated specimens is ascribed to strong interaction of glide dislocations with radiation induced defects. The activation energy for the movement of dislocations was found to be higher in irradiated specimens as compared with the un-irradiated ones.

  1. Amorphization and dynamic annealing of hexagonal SiC upon heavy-ion irradiation: Effects on swelling and mechanical properties

    SciTech Connect

    Kerbiriou, Xavier; Costantini, Jean-Marc; Sauzay, Maxime; Sorieul, Stephanie; Thome, Lionel

    2009-04-01

    Structural, mechanical, and dimensional evolutions of silicon carbide (SiC) induced by heavy-ion irradiations are studied by means of Rutherford backscattering spectrometry and channeling (RBS/C), nanoindentation, and surface profilometry measurements. 4H- and 6H-SiC single crystals were irradiated with 4 MeV Au{sup 2+} and 4 MeV Xe{sup +} ions at room temperature (RT) or 400 deg. C. Using a Monte Carlo program to simulate the RBS/C spectra (MCCHASY code), we find that Au ion irradiation at RT induces a total silicon sublattice disorder related to full amorphization at a dose of about 0.4 displacement per atom (dpa). A two-step damage process is found on the basis of the disordered fractions deduced from RBS/C data. Complete amorphization cannot be reached upon both Au and Xe ion irradiations at 400 deg. C up to about 26 dpa because of the dynamic annealing of defects. When complete amorphization is reached at RT, the Young's modulus and Berkovich hardness of irradiated 6H-SiC samples are lower by, respectively, 40% and 45% than those of the virgin crystals. The out-of-plane expansion measured by surface profilometry increases versus irradiation dose and the saturation value measured in the completely amorphous layer (normalized to the ion projected range) is close to 25%. We show that the modifications of the macroscopic properties are mainly due to the amorphization of the material. The macroscopic elasticity constants and dimensional properties are predicted for a composite material made of crystalline matrix containing dispersed amorphous inclusions using simple analytical homogenization models. Voigt's model seems to give the best approximation for disordered fractions larger than 20% in the second step of the damage process.

  2. Phytosanitary Irradiation

    PubMed Central

    Hallman, Guy J.; Blackburn, Carl M.

    2016-01-01

    Phytosanitary treatments disinfest traded commodities of potential quarantine pests. Phytosanitary irradiation (PI) treatments use ionizing radiation to accomplish this, and, since their international commercial debut in 2004, the use of this technology has increased by ~10% annually. Generic PI treatments (one dose is used for a group of pests and/or commodities, although not all have been tested for efficacy) are used in virtually all commercial PI treatments, and new generic PI doses are proposed, such as 300 Gy, for all insects except pupae and adult Lepidoptera (moths). Fresh fruits and vegetables tolerate PI better than any other broadly used treatment. Advances that would help facilitate the use of PI include streamlining the approval process, making the technology more accessible to potential users, lowering doses and broadening their coverage, and solving potential issues related to factors that might affect efficacy. PMID:28231103

  3. Comparison of Deuterium Retention for Ion-irradiated and Neutron-irradiated Tungsten

    SciTech Connect

    Yasuhisa Oya; Masashi Shimada; Makoto Kobayashi; Takuji Oda; Masanori Hara; Hideo Watanabe; Yuji Hatano; Pattrick Calderoni; Kenji Okuno

    2011-12-01

    The behavior of D retention for Fe{sup 2+}-irradiated tungsten with a damage of 0.025-3 dpa was compared with that for neutron-irradiated tungsten with 0.025 dpa. The D{sub 2} thermal desorption spectroscopy (TDS) spectra for Fe{sup 2+}-irradiated tungsten consisted of two desorption stages at 450 and 550 K, while that for neutron-irradiated tungsten was composed of three stages and an addition desorption stage was found at 750 K. The desorption rate of the major desorption stage at 550K increased as the displacement damage increased due to Fe{sup 2+} irradiation increasing. In addition, the first desorption stage at 450K was found only for damaged samples. Therefore, the second stage would be based on intrinsic defects or vacancy produced by Fe{sup 2+} irradiation, and the first stage should be the accumulation of D in mono-vacancy and the activation energy would be relatively reduced, where the dislocation loop and vacancy is produced. The third one was found only for neutron irradiation, showing the D trapping by a void or vacancy cluster, and the diffusion effect is also contributed to by the high full-width at half-maximum of the TDS spectrum. Therefore, it can be said that the D{sub 2} TDS spectra for Fe{sup 2+}-irradiated tungsten cannot represent that for the neutron-irradiated one, indicating that the deuterium trapping and desorption mechanism for neutron-irradiated tungsten is different from that for the ion-irradiated one.

  4. One Room Schools in Iowa.

    ERIC Educational Resources Information Center

    Ruth, Amy, Ed.

    1994-01-01

    This issue focuses on one-room school houses in Iowa. At one time, almost 14,000 one-room schools dotted Iowa's rural landscape. Articles explore Native American schools of the past and present, segregation of black students, and Amish schools. An article remembering one-room schools describes the early schools from 1830 to 1858, township schools…

  5. An electron spin resonance study of some gamma-irradiated fruits

    NASA Astrophysics Data System (ADS)

    Maloney, Darren R.; Tabner, Brian J.; Tabner, Vivienne A.

    The ESR spectra of the seeds, skins and stalks of unirradiated and γ-irradiated Chilean white grapes have been obtained and the results compared to those previously reported for Cape black grapes. The high degree of reproducibility of the spectra obtained from the stalks of different varieties of grapes suggest that ESR spectroscopy could form the basis of a viable test to determine their irradiation history. The condition of the stalk prior to irradiation has been found to have little effect on the resulting spectra. The spectra from the stalks, skins and seeds of unirradiated and γ-irradiated apples, peers and cherries have also been examined. Although most of the spectra from irradiated components exhibit extra features, they are sometimes short-lived and restrict the development of ESR as a viable test.

  6. STS-127 Firing Room

    NASA Image and Video Library

    2009-07-11

    NASA Johnson Space Center Director Michael Coats monitors the launch team discussions on his headset from Firing Room Four of the Launch Control Center at NASA's Kennedy Space Center in Cape Canaveral, Florida, Sunday, July 12, 2009. The space shuttle Endeavour is set to launch at 7:13p.m. EDT with the crew of STS-127 and start a 16-day mission that will feature five spacewalks and complete construction of the Japan Aerospace Exploration Agency's Kibo laboratory. Photo Credit: (NASA/Bill Ingalls)

  7. Early Damage Mechanisms in Nuclear Grade Graphite under Irradiation

    SciTech Connect

    Eapen, Dr. Jacob; Krishna, Dr Ram; Burchell, Timothy D; Murty, Prof K.L.

    2014-01-01

    Using Raman and X-ray photoelectron spectroscopy,we delineate the bond and defect structures in nuclear block graphite (NBG-18) under neutron and ion irradiation. The strengthening of the defect (D) peak in the Raman spectra under irradiation is attributed to an increase in the topological, sp2-hybridized defects. Using transmission electron microscopy, we provide evidence for prismatic dislocations as well as a number of basal dislocations dissociating into Shockley partials. The non-vanishing D peak in the Raman spectra, together with a generous number of dislocations, even at low irradiation doses, indicates a dislocation-mediated amorphization process in graphite.

  8. Action spectra again?

    PubMed

    Coohill, T P

    1991-11-01

    Action spectroscopy has a long history and is of central importance to photobiological studies. Action spectra were among the first assays to point to chlorophyll as the molecule most responsible for plant growth and to DNA as the genetic material. It is useful to construct action spectra early in the investigation of new areas of photobiological research in an attempt to determine the wavelength limits of the radiation region causing the studied response. But due to the severe absorption of ultraviolet (UV) radiation by biological samples, UV action spectra were first limited to small cells (bacteria and fungi). Advances in techniques (e.g. single cell culture) and analysis allowed accurate action spectra to be reported even for mammalian cells. But precise analytical action spectra are often difficult to obtain when large, pigmented, or groups of cells are investigated. Here some action spectra are limited in interpretation and merely supply a wavelength vs effect curve. When polychromatic sources are employed, the interpretation of action spectra is even more complex and formidable. But such polychromatic action spectra can be more directly related to ambient responses. Since precise action spectra usually require the completion of a relatively large number of careful experiments using somewhat sophisticated equipment over a range of at least six wavelengths, they are often not pursued. But they remain central to the elucidation of the effect being studied. The worldwide community has agreed that stratospheric ozone is depleting, with the possibility of a consequent rise in the amount of UV-B (290-320 nm) reaching the earth's surface. It is therefore essential that new action spectra be completed for UV-B effects on a large variety of responses of human, animal, and aquatic plant systems. Combining these action spectra with the known amounts of UV-B reaching the biosphere can give rise to solar UV effectiveness spectra that, in turn, can give rise to estimates

  9. KENNEDY SPACE CENTER, FLA. - Workers in NASA Spacecraft Hangar AE (background) remove sections of the transportation canister from around the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad. Additional workers (foreground) prepare the Delta payload attach fitting, from which SIRTF was demated, for further use. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

    NASA Image and Video Library

    2003-05-02

    KENNEDY SPACE CENTER, FLA. - Workers in NASA Spacecraft Hangar AE (background) remove sections of the transportation canister from around the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad. Additional workers (foreground) prepare the Delta payload attach fitting, from which SIRTF was demated, for further use. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

  10. KENNEDY SPACE CENTER, FLA. - Workers in NASA Spacecraft Hangar AE prepare to begin further processing of the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad. Sections of the transportation canister used in the move are in the foreground. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

    NASA Image and Video Library

    2003-05-02

    KENNEDY SPACE CENTER, FLA. - Workers in NASA Spacecraft Hangar AE prepare to begin further processing of the Space Infrared Telescope Facility (SIRTF), which has been returned to the hangar from the launch pad. Sections of the transportation canister used in the move are in the foreground. SIRTF will remain in the clean room until it returns to the pad in early August. One of NASA's largest infrared telescopes to be launched, SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space.

  11. Spectral measurements of asymmetrically irradiated capsule backlighters

    DOE PAGES

    Keiter, P. A.; Drake, R. P.

    2016-09-09

    Capsule backlighters provide a quasi-continuum x-ray spectrum over a wide range of photon energies. Ideally one irradiates the capsule backlighter symmetrically, however, in complex experimental geometries, this is not always possible. In recent experiments we irradiated capsule backlighters asymmetrically and measured the x-ray spectrum from multiple directions. We will present time-integrated spectra over the photon energy range of ~2-13 keV and time-resolved spectra over the photon energy range of ~2-3 keV. Lastly, we will compare the spectra from different lines of sight to determine if the laser asymmetry results in an angular dependence in the x-ray emission.

  12. Spectral measurements of asymmetrically irradiated capsule backlighters

    NASA Astrophysics Data System (ADS)

    Keiter, P. A.; Drake, R. P.

    2016-11-01

    Capsule backlighters provide a quasi-continuum x-ray spectrum over a wide range of photon energies [J. F. Hansen et al., Rev. Sci. Instrum. 79, 013504 (2008)]. Ideally one irradiates the capsule backlighter symmetrically, however, in complex experimental geometries, this is not always possible. In recent experiments we irradiated capsule backlighters asymmetrically and measured the x-ray spectrum from multiple directions. We will present time-integrated spectra over the photon energy range of 2-13 keV and time-resolved spectra over the photon energy range of 2-3 keV. We will compare the spectra from different lines of sight to determine if the laser asymmetry results in an angular dependence in the x-ray emission.

  13. Spectral measurements of asymmetrically irradiated capsule backlighters

    SciTech Connect

    Keiter, P. A.; Drake, R. P.

    2016-09-09

    Capsule backlighters provide a quasi-continuum x-ray spectrum over a wide range of photon energies. Ideally one irradiates the capsule backlighter symmetrically, however, in complex experimental geometries, this is not always possible. In recent experiments we irradiated capsule backlighters asymmetrically and measured the x-ray spectrum from multiple directions. We will present time-integrated spectra over the photon energy range of ~2-13 keV and time-resolved spectra over the photon energy range of ~2-3 keV. Lastly, we will compare the spectra from different lines of sight to determine if the laser asymmetry results in an angular dependence in the x-ray emission.

  14. Effect of an electron beam irradiation on optical and luminescence properties of LiBaAlF6 single crystals

    NASA Astrophysics Data System (ADS)

    Ogorodnikov, I. N.; Pustovarov, V. A.; Omelkov, S. I.; Kirm, M.

    2017-07-01

    Paper reports the effect of a 10 keV, 110 keV and 10 MeV electron beam irradiation on optical and luminescence properties of LiBaAlF6 (LBAF) single crystals at 10, 90, and 293 K. Five absorption bands at 2.0, 3.2, 4.3, 4.9 and 5.5 eV were revealed in irradiated crystals in the energy range of 1.2-9.5 eV. Several PL emission bands (1.7-1.8, 2.2 and 2.5-3.5 eV) related to defects were found in the luminescence spectra at room temperature, while only one luminescence band at E = 2.2 eV appears at T = 90 K in LBAF crystals after a 10 MeV electron bombardment. The PL excitation spectra and time-response for these emission bands were studied at 10, 90, and 293 K. Thermoluminescence (TL) of irradiated crystals was studied in the temperature range of 90-740 K. New TL glow peaks at 166, 530 and 670 K were revealed and their parameters were determined. Temperature dependence of relative photoluminescence yield recorded monitoring emission at the 1.87 and 2.23 eV in the temperature range from 130 to 450 K, were fitted using five quenching processes related to TL glow peaks revealed in our research. Significant similarity in the manifestation of radiation-induced defects for LBAF and previously studied LiBaF3 single crystals is noted. The effect of an electron beam irradiation on optical and luminescence properties of LBAF single crystals and possible origin of the radiation defects were discussed.

  15. Polymer Morphological Change Induced by Terahertz Irradiation.

    PubMed

    Hoshina, Hiromichi; Suzuki, Hal; Otani, Chiko; Nagai, Masaya; Kawase, Keigo; Irizawa, Akinori; Isoyama, Goro

    2016-06-07

    As terahertz (THz) frequencies correspond to those of the intermolecular vibrational modes in a polymer, intense THz wave irradiation affects the macromolecular polymorph, which determines the polymer properties and functions. THz photon energy is quite low compared to the covalent bond energy; therefore, conformational changes can be induced "softly," without damaging the chemical structures. Here, we irradiate a poly(3-hydroxybutylate) (PHB) / chloroform solution during solvent casting crystallization using a THz wave generated by a free electron laser (FEL). Morphological observation shows the formation of micrometer-sized crystals in response to the THz wave irradiation. Further, a 10-20% increase in crystallinity is observed through analysis of the infrared (IR) absorption spectra. The peak power density of the irradiating THz wave is 40 MW/cm(2), which is significantly lower than the typical laser intensities used for material manipulation. We demonstrate for the first time that the THz wave effectively induces the intermolecular rearrangement of polymer macromolecules.

  16. In Situ Irradiation and Measurement of Triple Junction Solar Cells at Low Intensity, Low Temperature (LILT) Conditions

    NASA Technical Reports Server (NTRS)

    Harris, R.D.; Imaizumi, M.; Walters, R.J.; Lorentzen, J.R.; Messenger, S.R.; Tischler, J.G.; Ohshima, T.; Sato, S.; Sharps, P.R.; Fatemi, N.S.

    2008-01-01

    The performance of triple junction InGaP/(In)GaAs/Ge space solar cells was studied following high energy electron irradiation at low temperature. Cell characterization was carried out in situ at the irradiation temperature while using low intensity illumination, and, as such, these conditions reflect those found for deep space, solar powered missions that are far from the sun. Cell characterization consisted of I-V measurements and quantum efficiency measurements. The low temperature irradiations caused substantial degradation that differs in some ways from that seen after room temperature irradiations. The short circuit current degrades more at low temperature while the open circuit voltage degrades more at room temperature. A room temperature anneal after the low temperature irradiation produced a substantial recovery in the degradation. Following irradiation at both temperatures and an extended room temperature anneal, quantum efficiency measurement suggests that the bulk of the remaining damage is in the (In)GaAs sub-cell

  17. In Situ Irradiation and Measurement of Triple Junction Solar Cells at Low Intensity, Low Temperature (LILT) Conditions

    NASA Technical Reports Server (NTRS)

    Harris, R.D.; Imaizumi, M.; Walters, R.J.; Lorentzen, J.R.; Messenger, S.R.; Tischler, J.G.; Ohshima, T.; Sato, S.; Sharps, P.R.; Fatemi, N.S.

    2008-01-01

    The performance of triple junction InGaP/(In)GaAs/Ge space solar cells was studied following high energy electron irradiation at low temperature. Cell characterization was carried out in situ at the irradiation temperature while using low intensity illumination, and, as such, these conditions reflect those found for deep space, solar powered missions that are far from the sun. Cell characterization consisted of I-V measurements and quantum efficiency measurements. The low temperature irradiations caused substantial degradation that differs in some ways from that seen after room temperature irradiations. The short circuit current degrades more at low temperature while the open circuit voltage degrades more at room temperature. A room temperature anneal after the low temperature irradiation produced a substantial recovery in the degradation. Following irradiation at both temperatures and an extended room temperature anneal, quantum efficiency measurement suggests that the bulk of the remaining damage is in the (In)GaAs sub-cell

  18. Interactive spectra demonstration

    NASA Astrophysics Data System (ADS)

    Palmquist, Bruce C.

    2002-03-01

    This report describes an interactive demonstration to help students qualitatively understand emission, continuous, and absorption spectra. Students throw colored balls at a person representing an electron that can move between discrete energy levels.

  19. He ion irradiation effects on multiwalled carbon nanotubes structure

    NASA Astrophysics Data System (ADS)

    Elsehly, Emad M.; Chechenin, Nikolay G.; Makunin, Alexey V.; Shemukhin, Andrey A.; Motaweh, Hussien A.

    2017-03-01

    Samples of multi-walled carbon nanotubes (MWNTs) were irradiated with 80 keV He ions. Scanning electron microscopy (SEM) inspection showed that the average outer diameters of the tube decreased as a result of ion irradiation. The samples were also characterized using Raman spectrometry by analysis of the intensity of main bands in the spectra of virgin and irradiated MWNT samples. Modifications of the disorder mode (D-band) and the tangential mode (G-band) were studied as a function of irradiation fluences. Raman spectra showed that as the fluence increases, the MWNTs first show disorder due to the produced defects, and then amorphization under still higher fluence of ion irradiation. Thermal and athermal mechanisms of the radiation induced MWNTs modifications are discussed. Contribution to the Topical Issue "Many Particle Spectroscopy of Atoms, Molecules, Clusters and Surfaces", edited by A.N. Grum-Grzhimailo, E.V. Gryzlova, Yu V. Popov, and A.V. Solov'yov.

  20. EPR investigation of some gamma-irradiated excipients

    NASA Astrophysics Data System (ADS)

    Aleksieva, Katerina; Yordanov, Nicola D.

    2012-09-01

    The results of electron paramagnetic resonance (EPR) studies on some excipients: lactose, microcrystalline cellulose (avicel), starch, dioxosilane (aerosil), talc and magnesium stearate before and after gamma-irradiation are reported. Before irradiation, all samples are EPR silent except talc. After gamma-irradiation, they show complex spectra except magnesium stearate, which is EPR silent. Studies show the influence of gamma-irradiation on EPR spectra and stability of gamma-induced radicals. Analysis of the EPR spectrum of gamma-irradiated talc shows that this material is radiation insensitive. Only lactose forms stable-free radicals upon gamma sterilization and can be used for identification of radiation processing for a long time period thereafter.

  1. Multivariate classification of infrared spectra of cell and tissue samples

    DOEpatents

    Haaland, David M.; Jones, Howland D. T.; Thomas, Edward V.

    1997-01-01

    Multivariate classification techniques are applied to spectra from cell and tissue samples irradiated with infrared radiation to determine if the samples are normal or abnormal (cancerous). Mid and near infrared radiation can be used for in vivo and in vitro classifications using at least different wavelengths.

  2. Low-temperature EPR spectra of synthetic diamond and type Ib nanodiamond

    NASA Astrophysics Data System (ADS)

    Vaisnoras, R.; Kulbickas, A.; Kobets, M.; Dergachev, K.; Khatsko, E.

    2013-11-01

    Low-frequency resonance studies of single crystal diamond and type Ib nanodiamond (powder) unirradiated and irradiated by protons at temperatures of 300 and 500 K are reported. EPR spectra typical of paramagnetic nitrogen centers are observed. It is shown that when synthetic diamond crystals are irradiated by protons, additional lines appear in the EPR spectra which can be attributed to radiation induced nitrogen-vacancy centers (NV defects).

  3. Ferromagnetic resonance spectra of H2-reduced minerals and glasses

    NASA Technical Reports Server (NTRS)

    Morris, Richard V.; Allen, Carlton C.

    1994-01-01

    In an earlier paper, we reported that H2 reduction of basaltic glass, olivine, pyroxene, and plagioclase resulted in the formation of metallic iron, in the darkening and reddening of the reflectance spectra, and the masking of individual spectral features in the visible and near-IR. In this work, we report FMR spectra for H2-reduced minerals and glasses that include the samples studied in the earlier paper. The FMR spectra were reduced at room temperature at a nominal frequency of 9.5 GHz. Sample saturation magnetization reported as F3(0) was measured with a vibrating sample magnetometer.

  4. CEBAF Control Room Renovation

    SciTech Connect

    Michael Spata; Thomas Oren

    2005-05-01

    The Machine Control Center (MCC) at Jefferson Lab's Continuous Electron Beam Accelerator Facility (CEBAF) was initially constructed in the early 1990s and based on proven technology of that era. Through our experience over the last 15 years and in our planning for the facility's 12 GeV upgrade we reevaluated the control room environment to capitalize on emerging visualization and display technologies and improve workflow processes and ergonomic attributes. This effort also sets the foundation for the redevelopment of the accelerator's control system to deliver high reliability performance with improvements in beam specifications management and information flow. The complete renovation was performed over a three-week maintenance period with no interruption to beam operations. We present the results of this effort.

  5. CEBAF Control Room Renovation

    SciTech Connect

    Michael Spata; Thomas Oren

    2005-05-01

    The Machine Control Center at Jefferson Lab's Continuous Electron Beam Accelerator Facility was initially constructed in the early 1990s and based on proven technology of that era. Through our experience over the last 15 years and in our planning for the facilities 12 GeV upgrade we reevaluated the control room environment to capitalize on emerging visualization and display technologies and improve on workflow processes and ergonomic attributes. This effort also sets the foundation for the redevelopment of the accelerator's control system to deliver high reliability performance with improvements in beam specifications management and information flow. The complete renovation was performed over a three-week period with no interruption to beam operations. We present the results of this effort.

  6. CEBAF Control Room Renovation

    SciTech Connect

    Michael Spata; Anthony Cuffe; Thomas Oren

    2005-03-22

    The Machine Control Center (MCC) at Jefferson Lab's Continuous Electron Beam Accelerator Facility (CEBAF) was constructed in the early 1990s and based on proven technology of that era. Through our experience over the last 15 years and in our planning for the facilities 12 GeV upgrade we reevaluated the control room environment to capitalize on emerging visualization and display technologies and improve on work-flow processes and ergonomic attributes. The renovation was performed in two phases during the summer of 2004, with one phase occurring during machine operations and the latter, more extensive phase, occurring during our semi-annual shutdown period. The new facility takes advantage of advances in display technology, analog and video signal management, server technology, ergonomic workspace design, lighting engineering, acoustic ceilings and raised flooring solutions to provide a marked improvement in the overall environment of machine operations.

  7. Binaural room simulation

    NASA Technical Reports Server (NTRS)

    Lehnert, H.; Blauert, Jens; Pompetzki, W.

    1991-01-01

    In every-day listening the auditory event perceived by a listener is determined not only by the sound signal that a sound emits but also by a variety of environmental parameters. These parameters are the position, orientation and directional characteristics of the sound source, the listener's position and orientation, the geometrical and acoustical properties of surfaces which affect the sound field and the sound propagation properties of the surrounding fluid. A complete set of these parameters can be called an Acoustic Environment. If the auditory event perceived by a listener is manipulated in such a way that the listener is shifted acoustically into a different acoustic environment without moving himself physically, a Virtual Acoustic Environment has been created. Here, we deal with a special technique to set up nearly arbitrary Virtual Acoustic Environments, the Binaural Room Simulation. The purpose of the Binaural Room Simulation is to compute the binaural impulse response related to a virtual acoustic environment taking into account all parameters mentioned above. One possible way to describe a Virtual Acoustic Environment is the concept of the virtual sound sources. Each of the virtual sources emits a certain signal which is correlated but not necessarily identical with the signal emitted by the direct sound source. If source and receiver are non moving, the acoustic environment becomes a linear time-invariant system. Then, the Binaural Impulse Response from the source to a listener' s eardrums contains all relevant auditory information related to the Virtual Acoustic Environment. Listening into the simulated environment can easily be achieved by convolving the Binaural Impulse Response with dry signals and representing the results via headphones.

  8. Use of Irradiated Foods

    NASA Technical Reports Server (NTRS)

    Brynjolfsson, A.

    1985-01-01

    The safety of irradiated foods is reviewed. Guidelines and regulations for processing irradiated foods are considered. The radiolytic products formed in food when it is irradiated and its wholesomeness is discussed. It is concluded that food irradiation processing is not a panacea for all problems in food processing but when properly used will serve the space station well.

  9. Use of Irradiated Foods

    NASA Technical Reports Server (NTRS)

    Brynjolfsson, A.

    1985-01-01

    The safety of irradiated foods is reviewed. Guidelines and regulations for processing irradiated foods are considered. The radiolytic products formed in food when it is irradiated and its wholesomeness is discussed. It is concluded that food irradiation processing is not a panacea for all problems in food processing but when properly used will serve the space station well.

  10. Formation and trapping of free radicals in irradiated purines: EPR and ENDOR of hypoxanthine derivatives studied as single crystals

    NASA Astrophysics Data System (ADS)

    Tokdemir, Sibel

    Four different derivatives of hypoxanthine (hypoxanthine-HCl·H 2O, Na+·Inosine-·2.5H 2O, sodium inosine monophosphate, and calcium inosine monophosphate) were irradiated in the form of single crystals with the objective of identifying the radical products. To do so, magnetic resonance methods (EPR, ENDOR experiments and EPR spectrum simulations) were used to study radical products in crystals following x-irradiation at ˜10 K without warming, and under conditions of controlled warming. Also, computational chemistry methods were used in combination with the experimental methods to assist in identifying the radical products. Immediately following irradiation at 10 K, at least three different radicals were observed for hypoxanthine·HCl·H2O. R5.1 was identified at the product of electron addition followed by protonation of the parent at N3. R5.2 was identified as the product of electron loss followed by deprotonation at N7, and R5.3 was tentatively identified as the product of electron gain followed by protonation at 06. On warming to room temperature, three new radicals were observed: R6.1 and R6.3 were the products of net H addition to C8 and C2 respectively, while R6.2 was the product of OH addition to C8. At least four different radical products of Na+·Inosine - were detected immediately after irradiation at 10 K. R7.1 was identified as the electron-loss product of the parent hypoxanthine base, and R7.2 was identified as the product of net H-abstraction from C5 ' of the sugar. R7.3 and R7.4 were tentatively identified as the products of net H-addition to 06 (probably via electron addition followed by protonation), and the (doubly-negative) product of electron-gain, respectively. R7.5, the C8-H addition radical, was the only product detected on warming sodium inosine crystals to room temperature. Because the ENDOR spectra from sodium IMP irradiated at 10K were complex, it was possible to identify only two radicals. R8.1 was identified as the purine base

  11. A EPR Investigation of Atomic Silver and Divalent Silver in Irradiated Single Crystal of Potassium Fluoride Doped with Silver Fluoride

    NASA Astrophysics Data System (ADS)

    Yu, Cheng

    The electron paramagnetic resonance absorption spectra of a singly ionized diatomic fluoride molecule -ion F_2^-, atomic silver Ag^0 and divalent silver Ag ^{2+} contained in single crystals of potassium fluoride have been re-examined at X-band wavelengths. The F_2^- and Ag^0 centers are produced simultaneously by gamma-irradiation at liquid nitrogen temperature. The divalent silver Ag^{2+} centers are formed by subsequently warming the irradiated samples to room temperature for a few hours and then cooling to 77 K. All field strength positions of resonance absorption lines observed at low temperatures have been satisfactorily predicted by computer simulation. The high degree of resolution exhibited by the spectra is due in part to the large nuclear magnetic moment of fluorine and in part to the fact that spectral lines in KF are narrow compared to those of similar systems in other alkali halide crystals. For an atomic silver, the hexafluoride cluster is cubic. By contrast, the divalent silver center is tetragonally distorted along a crystal cube edge as a consequence of the Jahn-Teller effect. Unexpected splittings of the central lines in the resonance absorption spectrum of divalent silver are observed and interpreted as being due to second order perturbation effects.

  12. Detection of irradiated liquor

    NASA Astrophysics Data System (ADS)

    Shengchu, Qi; Jilan, Wu; Rongyao, Yuan

    D-2,3-butanediol is formed by irradiation processes in irradiated liquors. This radiolytic product is not formed in unirradiated liquors and its presence can therefore be used to identify whether a liquor has been irradiated or not. The relation meso/dl≈1 for 2,3-butanediol and the amount present in irradiated liquors may therefore be used as an indication of the dose used in the irradiation.

  13. The room acoustic rendering equation.

    PubMed

    Siltanen, Samuel; Lokki, Tapio; Kiminki, Sami; Savioja, Lauri

    2007-09-01

    An integral equation generalizing a variety of known geometrical room acoustics modeling algorithms is presented. The formulation of the room acoustic rendering equation is adopted from computer graphics. Based on the room acoustic rendering equation, an acoustic radiance transfer method, which can handle both diffuse and nondiffuse reflections, is derived. In a case study, the method is used to predict several acoustic parameters of a room model. The results are compared to measured data of the actual room and to the results given by other acoustics prediction software. It is concluded that the method can predict most acoustic parameters reliably and provides results as accurate as current commercial room acoustic prediction software. Although the presented acoustic radiance transfer method relies on geometrical acoustics, it can be extended to model diffraction and transmission through materials in future.

  14. Neutron Spectra in a 15 MV LINAC

    SciTech Connect

    Vega-Carrillo, H. R.; Chu, Wei-Han; Tung, Chuan-Jong; Lan, Jen-Hong

    2010-12-07

    Neutron spectra were calculated inside the treatment hall of a 15 MV LINAC, calculations were carried out using Monte Carlo methods. With a Bonner sphere spectrometer with pairs of thermoluminiscent dosimeters the neutron spectrum at 100 cm from the isocenter was measured and compared with the calculated spectrum. All the spectra in the treatment hall show the presence of evaporation and knock-on neutrons; also the room-return due to the hall features is shown. In the maze the large contribution are due to epithermal and thermal neutrons. A good agreement between the calculated and measured spectrum at 100 cm was noticed, from this comparison the differences are attributed to the water content in the concrete of the hall.

  15. Neutron Spectra in a 15 MV LINAC

    NASA Astrophysics Data System (ADS)

    Vega-Carrillo, H. R.; Chu, Wei-Han; Tung, Chuan-Jong; Lan, Jen-Hong

    2010-12-01

    Neutron spectra were calculated inside the treatment hall of a 15 MV LINAC, calculations were carried out using Monte Carlo methods. With a Bonner sphere spectrometer with pairs of thermoluminiscent dosimeters the neutron spectrum at 100 cm from the isocenter was measured and compared with the calculated spectrum. All the spectra in the treatment hall show the presence of evaporation and knock-on neutrons; also the room-return due to the hall features is shown. In the maze the large contribution are due to epithermal and thermal neutrons. A good agreement between the calculated and measured spectrum at 100 cm was noticed, from this comparison the differences are attributed to the water content in the concrete of the hall.

  16. The LASP Interactive Solar IRradiance Datacenter (LISIRD)

    NASA Astrophysics Data System (ADS)

    Snow, M.; Woods, T. N.; Eparvier, F. G.; Fontenla, J.; Harder, J.; McClintock, W. E.; Pankratz, C.; Richard, E.; Windnagel, A.; Woodraska, D.

    2005-12-01

    LASP has created an online resource for combined solar irradiance datasets from the SORCE, TIMED, UARS, and SME missions. The LASP Interactive Solar IRradiance Datacenter (LISIRD) not only provides unified access to the individual datasets, but also combines them for ease of use by scientists, educators, and the general public. In particular, LISIRD makes available composite spectra and time series. The TIMED SEE, SORCE SOLSTICE, and SORCE SIM instruments produce spectra that together cover the solar spectrum from 1 to 2700 nm. Through the LISIRD interface, the user can get data that bridges the various missions in both wavelength and time. LISIRD also hosts data products of interest to the space weather community. They have slightly different needs than the atmospheric modelers that are the typical users of irradiance data. For space weather applications, high time cadence and near real-time data delivery are key. For these users, we make our observations available shortly after spacecraft contact, and append the observations to a single data file which they can retrieve using anonymous ftp every few hours. The third component of LISIRD is the Solar Physical Radiation Model (SPRM) results of Fontenla et al. It provides a model of current solar activity, the synthetic spectral irradiance, and tools that permit one to model the solar activity source of the spectral irradiance variations.

  17. PARAFAC analysis of IBIL spectra from silver ion exchanged glasses

    NASA Astrophysics Data System (ADS)

    Valotto, G.; Cattaruzza, E.; Mardegan, M.; Quaranta, A.

    2017-01-01

    In this work we present for the first time an application of PARAllel FACtor (PARAFAC) analysis to the investigation of Ion Beam Induced Luminescence (IBIL) spectra of Ag+ ↔ Na+ ion exchanged silicate glasses, in order to check the possibility to obtain additional information on the formation of silver aggregates under ion irradiation by a proper statistical rearrangement of experimental spectra. We decomposed the data by PARAFAC taking into account both IBIL emission features and their evolution as a function of the time. Shape and trend under irradiation of the extracted components were correlated to silver concentration and aggregates in the investigated systems. Strength and weakness of this statistical approach applied to IBIL spectra recorded as a function of time were evidenced and discussed.

  18. 16. Perimeter acquisition radar building room #102, electrical equipment room; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. Perimeter acquisition radar building room #102, electrical equipment room; the prime power distribution system. Excellent example of endulum-types shock isolation. The grey cabinet and barrel assemble is part of the polychlorinated biphenyl (PCB) retrofill project - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

  19. 37. DINING ROOM FROM BALCONY. THE DINING ROOM ROOF IS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    37. DINING ROOM FROM BALCONY. THE DINING ROOM ROOF IS SUPPORTED BY A SCISSOR TRUSS SYSTEM REINFORCED WITH TURNBUCKLE IRON RODS AND GUSSET PLATES (NOTE: THIS SYSTEM DIFFERS FROM THE LOBBY). - Old Faithful Inn, 900' northeast of Snowlodge & 1050' west of Old Faithful Lodge, Lake, Teton County, WY

  20. LIVING ROOM WITH THE SLIDING DOORS TO DINING ROOM ON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LIVING ROOM WITH THE SLIDING DOORS TO DINING ROOM ON THE LEFT. SHOWING THE WOOD GRILLE TO THE FOYER. VIEW FACING SOUTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, U-Shaped Two-Bedroom Duplex Type 1, Acacia Road, Birch Circle, and Cedar Drive, Pearl City, Honolulu County, HI

  1. 10. CONTROL ROOM INTERIOR. Looking into southwest corner. CONTROL ROOM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. CONTROL ROOM INTERIOR. Looking into southwest corner. CONTROL ROOM INTERIOR, SHOWING ESCAPE HATCH. Looking north along east wall. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Instrumentation & Control Building, Test Area 1-115, northwest end of Saturn Boulevard, Boron, Kern County, CA

  2. 12. INTERIOR OF LIVING ROOM FROM DINING ROOM SHOWING OPEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. INTERIOR OF LIVING ROOM FROM DINING ROOM SHOWING OPEN FRONT DOOR AT PHOTO CENTER AND OPEN DOOR TO BEDROOM NO. 1 AT PHOTO LEFT. VIEW TO NORTH. - Bishop Creek Hydroelectric System, Plant 4, Worker Cottage, Bishop Creek, Bishop, Inyo County, CA

  3. 2. ENGINE ROOM AND CHIPPY ENGINE ROOM OF THE DIAMOND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. ENGINE ROOM AND CHIPPY ENGINE ROOM OF THE DIAMOND MINE, LOOKING NORTH. THE MAIN HOIST USED A FLAT CABLE, WHICH WAS SCRAPPED IN THE 1950s. THE ORIGINAL DIXON CABLE STILL EXISTS IN THE CHIPPY HOIST HOUSE. - Butte Mineyards, Diamond Mine, Butte, Silver Bow County, MT

  4. 49. Machinery rooms on north tower. Facing north. Machinery rooms ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    49. Machinery rooms on north tower. Facing north. Machinery rooms contain all motors, motor controllers, and gears for operating one span, in this case, the north span. Note bell with continuous operating clapper for use as fog signals. - Henry Ford Bridge, Spanning Cerritos Channel, Los Angeles-Long Beach Harbor, Los Angeles, Los Angeles County, CA

  5. 35. VIEW OF TELEMETRY ROOM (ROOM 106) FROM ITS NORTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    35. VIEW OF TELEMETRY ROOM (ROOM 106) FROM ITS NORTHWEST CORNER SHOWING TM-ISE-3 TELEMETRY CHECKOUT SYSTEM AND HONEYWELL TAPE RECORDER - Vandenberg Air Force Base, Space Launch Complex 3, Launch Operations Building, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  6. Looking west in the basement utility room, room 24, overview ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Looking west in the basement utility room, room 24, overview of air handling system, large walk-in filter, large ducts, pipes, and gauges - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  7. From living room through french doors toward room in southeast ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    From living room through french doors toward room in southeast corner of south unit - Fitzsimons General Hospital, Civilian Employees' Quarters, North Hickey Street, West side, 150 feet North of intersection of North Hickey Street & West Loosley Avenue, Aurora, Adams County, CO

  8. 17. Perimeter acquisition radar building room #105, mechanical equipment room ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. Perimeter acquisition radar building room #105, mechanical equipment room no. 1; sign reads: Heat exchangers (shell and tube type). Provide precise temperature control of water for cooling critical electronic equipment - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

  9. 16. Bus Room (also known as Switch Gear Room), view ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. Bus Room (also known as Switch Gear Room), view to the southeast. An air circuit breaker compressor (visible in photograph number 2) was once attached to the main bus relay visible in the background of the photograph. - Washington Water Power Clark Fork River Cabinet Gorge Hydroelectric Development, Powerhouse, North Bank of Clark Fork River at Cabinet Gorge, Cabinet, Bonner County, ID

  10. Raman spectroscopic analysis of iron chromium oxide microspheres generated by nanosecond pulsed laser irradiation on stainless steel.

    PubMed

    Ortiz-Morales, M; Soto-Bernal, J J; Frausto-Reyes, C; Acosta-Ortiz, S E; Gonzalez-Mota, R; Rosales-Candelas, I

    2015-06-15

    Iron chromium oxide microspheres were generated by pulsed laser irradiation on the surface of two commercial samples of stainless steel at room temperature. An Ytterbium pulsed fiber laser was used for this purpose. Raman spectroscopy was used for the characterization of the microspheres, whose size was found to be about 0.2-1.7 μm, as revealed by SEM analysis. The laser irradiation on the surface of the stainless steel modified the composition of the microspheres generated, affecting the concentration of the main elemental components when laser power was increased. Furthermore, the peak ratio of the main bands in the Raman spectra has been associated to the concentration percentage of the main components of the samples, as revealed by Energy-Dispersive X-ray Spectroscopy (EDS) analysis. These experiments showed that it is possible to generate iron chromium oxide microspheres on stainless steel by laser irradiation and that the concentration percentage of their main components is associated with the laser power applied.

  11. Defects responsible for lifetime degradation in electron irradiated n-GaN grown by hydride vapor phase epitaxy

    NASA Astrophysics Data System (ADS)

    Lee, In-Hwan; Polyakov, A. Y.; Yakimov, E. B.; Smirnov, N. B.; Shchemerov, I. V.; Tarelkin, S. A.; Didenko, S. I.; Tapero, K. I.; Zinovyev, R. A.; Pearton, S. J.

    2017-03-01

    The effects of room temperature 6 MeV electron irradiation on the donor concentration, deep trap spectra, and diffusion lengths of nonequilibrium charge carriers were studied for undoped n-GaN grown by hydride vapor phase epitaxy. Changes in these parameters begin at a threshold electron fluence of 5 × 1015 cm-2. The diffusion lengths after this fluence decrease by a factor of 3, accompanied by a drastic increase in the density of deep electron traps with the level near Ec - 1 eV. There is a strong correlation between the changes in the density of these traps and the diffusion length of irradiated n-GaN, indicating that these centers control the lifetime in radiation damaged n-GaN. This is in sharp contrast to the starting material, where the lifetimes are controlled by other deep electron traps at Ec - 0.56 eV. The concentration of the latter is not strongly affected by high energy electron irradiation.

  12. Direct Observation of Defect Range and Evolution in Ion-Irradiated Single Crystalline Ni and Ni Binary Alloys

    DOE PAGES

    Lu, Chenyang; Jin, Ke; Béland, Laurent K.; ...

    2016-02-01

    We report that energetic ions have been widely used to evaluate the irradiation tolerance of structural materials for nuclear power applications and to modify material properties. It is important to understand the defect production, annihilation and migration mechanisms during and after collision cascades. In this study, single crystalline pure nickel metal and single-phase concentrated solid solution alloys of 50%Ni50%Co (NiCo) and 50%Ni50%Fe (NiFe) without apparent preexisting defect sinks were employed to study defect dynamics under ion irradiation. Both cross-sectional transmission electron microscopy characterization (TEM) and Rutherford backscattering spectrometry channeling (RBS-C) spectra show that the range of radiation-induced defect clusters farmore » exceed the theoretically predicted depth in all materials after high-dose irradiation. Defects in nickel migrate faster than in NiCo and NiFe. Both vacancy-type stacking fault tetrahedra (SFT) and interstitial loops coexist in the same region, which is consistent with molecular dynamics simulations. Kinetic activation relaxation technique (k-ART) simulations for nickel showed that small vacancy clusters, such as di-vacancies and tri-vacancies, created by collision cascades are highly mobile, even at room temperature. The slower migration of defects in the alloy along with more localized energy dissipation of the displacement cascade may lead to enhanced radiation tolerance.« less

  13. Direct Observation of Defect Range and Evolution in Ion-Irradiated Single Crystalline Ni and Ni Binary Alloys

    SciTech Connect

    Lu, Chenyang; Jin, Ke; Béland, Laurent K.; Zhang, Feifei; Yang, Taini; Qiao, Liang; Zhang, Yanwen; Bei, Hongbin; Christen, Hans M.; Stoller, Roger E.; Wang, Lumin

    2016-02-01

    We report that energetic ions have been widely used to evaluate the irradiation tolerance of structural materials for nuclear power applications and to modify material properties. It is important to understand the defect production, annihilation and migration mechanisms during and after collision cascades. In this study, single crystalline pure nickel metal and single-phase concentrated solid solution alloys of 50%Ni50%Co (NiCo) and 50%Ni50%Fe (NiFe) without apparent preexisting defect sinks were employed to study defect dynamics under ion irradiation. Both cross-sectional transmission electron microscopy characterization (TEM) and Rutherford backscattering spectrometry channeling (RBS-C) spectra show that the range of radiation-induced defect clusters far exceed the theoretically predicted depth in all materials after high-dose irradiation. Defects in nickel migrate faster than in NiCo and NiFe. Both vacancy-type stacking fault tetrahedra (SFT) and interstitial loops coexist in the same region, which is consistent with molecular dynamics simulations. Kinetic activation relaxation technique (k-ART) simulations for nickel showed that small vacancy clusters, such as di-vacancies and tri-vacancies, created by collision cascades are highly mobile, even at room temperature. The slower migration of defects in the alloy along with more localized energy dissipation of the displacement cascade may lead to enhanced radiation tolerance.

  14. Direct Observation of Defect Range and Evolution in Ion-Irradiated Single Crystalline Ni and Ni Binary Alloys

    PubMed Central

    Lu, Chenyang; Jin, Ke; Béland, Laurent K.; Zhang, Feifei; Yang, Taini; Qiao, Liang; Zhang, Yanwen; Bei, Hongbin; Christen, Hans M.; Stoller, Roger E.; Wang, Lumin

    2016-01-01

    Energetic ions have been widely used to evaluate the irradiation tolerance of structural materials for nuclear power applications and to modify material properties. It is important to understand the defect production, annihilation and migration mechanisms during and after collision cascades. In this study, single crystalline pure nickel metal and single-phase concentrated solid solution alloys of 50%Ni50%Co (NiCo) and 50%Ni50%Fe (NiFe) without apparent preexisting defect sinks were employed to study defect dynamics under ion irradiation. Both cross-sectional transmission electron microscopy characterization (TEM) and Rutherford backscattering spectrometry channeling (RBS-C) spectra show that the range of radiation-induced defect clusters far exceed the theoretically predicted depth in all materials after high-dose irradiation. Defects in nickel migrate faster than in NiCo and NiFe. Both vacancy-type stacking fault tetrahedra (SFT) and interstitial loops coexist in the same region, which is consistent with molecular dynamics simulations. Kinetic activation relaxation technique (k-ART) simulations for nickel showed that small vacancy clusters, such as di-vacancies and tri-vacancies, created by collision cascades are highly mobile, even at room temperature. The slower migration of defects in the alloy along with more localized energy dissipation of the displacement cascade may lead to enhanced radiation tolerance. PMID:26829570

  15. Direct Observation of Defect Range and Evolution in Ion-Irradiated Single Crystalline Ni and Ni Binary Alloys

    NASA Astrophysics Data System (ADS)

    Lu, Chenyang; Jin, Ke; Béland, Laurent K.; Zhang, Feifei; Yang, Taini; Qiao, Liang; Zhang, Yanwen; Bei, Hongbin; Christen, Hans M.; Stoller, Roger E.; Wang, Lumin

    2016-02-01

    Energetic ions have been widely used to evaluate the irradiation tolerance of structural materials for nuclear power applications and to modify material properties. It is important to understand the defect production, annihilation and migration mechanisms during and after collision cascades. In this study, single crystalline pure nickel metal and single-phase concentrated solid solution alloys of 50%Ni50%Co (NiCo) and 50%Ni50%Fe (NiFe) without apparent preexisting defect sinks were employed to study defect dynamics under ion irradiation. Both cross-sectional transmission electron microscopy characterization (TEM) and Rutherford backscattering spectrometry channeling (RBS-C) spectra show that the range of radiation-induced defect clusters far exceed the theoretically predicted depth in all materials after high-dose irradiation. Defects in nickel migrate faster than in NiCo and NiFe. Both vacancy-type stacking fault tetrahedra (SFT) and interstitial loops coexist in the same region, which is consistent with molecular dynamics simulations. Kinetic activation relaxation technique (k-ART) simulations for nickel showed that small vacancy clusters, such as di-vacancies and tri-vacancies, created by collision cascades are highly mobile, even at room temperature. The slower migration of defects in the alloy along with more localized energy dissipation of the displacement cascade may lead to enhanced radiation tolerance.

  16. Effect of gamma irradiation on microbiological, chemical and sensory characteristics of licorice root product

    NASA Astrophysics Data System (ADS)

    Al-Bachir, M.; Al-Adawi, M. A.; Al-Kaid, A.

    2004-03-01

    Licorice root products were irradiated at doses of 0, 5, 10, 15 and 20 kGy in a 60Co package irradiator. Irradiated and unirradiated samples were stored at room temperatures. Microbial population on product, chemical changes and sensory properties of produced solution of licorice root products were evaluated after 0 and 12 months of storage. The results indicated that gamma irradiation reduced the counts of microorganisms on licorice root products. D10 of total count and klebsiella spp. were about 1.4 and 0.7 kGy, respectively. The mineral ions (Na, Ca and K) concentration in solution produced from irradiated products were lower than non-irradiated ones. Glycyrrhezinic acid and maltose concentration in solution produced from irradiated products were higher than non-irradiated ones. Sensory evaluation indicated that no significant differences ( P<0.05) were found between solution produced from irradiated and unirradiated products in color, flavor, texture, or taste.

  17. Investigations of Cadmium Manganese Telluride Crystals for Room-Temperature Radiation Detection

    SciTech Connect

    Yang, G.; Bolotnikov, A.; Camarda, G.; Cui, Y.; Hossain, A.; Kim, K.; Carcelen, V.; Gul, R.; James, R.

    2009-10-06

    Cadmium manganese telluride (CMT) has high potential as a material for room-temperature nuclear-radiation detectors. We investigated indium-doped CMT crystals taken from the stable growth region of the ingot, and compared its characteristics with that from the last-to-freeze region. We employed different techniques, including synchrotron white-beam X-ray topography (SWBXT), current-voltage (I-V) measurements, and low-temperature photoluminescence spectra, and we also assessed their responses as detectors to irradiation exposure. The crystal from the stable growth region proved superior to that from the last-to-freeze region; it is a single-grain crystal, free of twins, and displayed a resistivity higher by two orders-of-magnitude. The segregation of indium dopant in the ingot might be responsible for its better resistivity. Furthermore, we recorded a good response in the detector fabricated from the crystal taken from the stable growth region; its ({mu}{tau}){sub e} value was 2.6 x 10{sup -3} cm{sup 2}/V, which is acceptable for thin detectors, including for applications in medicine.

  18. Room temperature radiation products in trehalose single crystals: EMR and DFT analysis.

    PubMed

    De Cooman, Hendrik; Tarpan, Mihaela Adeluta; Vrielinck, Henk; Waroquier, Michel; Callens, Freddy

    2013-03-01

    Radicals generated in trehalose single crystals by X radiation at room temperature were investigated by electron paramagnetic resonance (EPR), electron nuclear double resonance (ENDOR) and ENDOR-induced EPR measurements, together with periodic density functional theory calculations. In the first days after irradiation, three radical species (I1, I2 and I3) were detected, two of which (I1 and I2) dominate the EPR spectrum and could be identified as H-abstracted species centered at C3' (I1) and C2 (I2), the latter with additional formation of a carbonyl group at C3. Annealing the sample at 40 °C for 3 days or storing it in ambient conditions for three months resulted in another, more stable EPR spectrum. Two major species could be characterized in this stage (S1 and S2), only one of which was tentatively identified as an H-abstracted, C2-centered species (S1). Our findings disagree with a previous EPR study [Gräslund and Löfroth (23)] on several accounts. This work stresses the need for caution when interpreting composite EPR spectra and thermally induced spectral changes of radiation-induced species, even in these relatively simple carbohydrates. It also provides further evidence that the pathways for radiation damage critically depend on the specific conformation of a molecule and its environment, but also that carbonyl group formation is a common process in the radiation chemistry of sugars and related compounds.

  19. Infrared spectra of cesium chloride aqueous solutions

    NASA Astrophysics Data System (ADS)

    Max, Jean-Joseph; Chapados, Camille

    2000-10-01

    The aqueous solutions of CsCl were studied at room temperature by infrared (IR) spectroscopy in the entire solubility range, 0-1200 g/L, using attenuated total reflection (ATR) sampling. The influence of anomalous dispersion on the IR-ATR spectra was evaluated by calculating the imaginary refractive index, k(ν), of each sample. Factor analysis (FA) was used to determine the number and abundance of species in the solutions. FA applied to both k(ν) spectra and IR-ATR spectra produced two principal spectra with a similar abundance of species. This result indicates that, even at high salt concentration, the optical effects do not influence the chemical analysis of IR-ATR spectra. The spectral modifications related to the salt concentrations are mainly first order. Second order effects were observed, but being weak, were not investigated. The two principal spectra are related to the two species present in the solution: pure water and CsCl-solvated water. From the latter, 2.8±0.4 water molecules were calculated to be associated with each close-bound Cs+/Cl- ion pair. In the case of KCl and NaCl aqueous solutions, both of which showed the same number of species, the number of water molecules associated to an ion pair was 5.0±0.4. That the latter number is different from that of CsCl indicates that the interaction between water molecules and ion pairs is different when cation Na or K in the chloride salt is replaced by Cs.

  20. Room temperature polyesterification

    SciTech Connect

    Moore, J.S.; Stupp, S.I. . Dept. of Materials Science and Engineering)

    1990-01-01

    A new room temperature polymerization method has been developed for the synthesis of high molecular weight polyesters directly from carboxylic acids and phenols. The solution polymerization reaction proceeds under mild conditions, near neutral pH, and also avoids the use of preactivated acid derivatives for esterification. The reaction is useful in the preparation of isoregic ordered chains with translational polar symmetry and also in the polymerization of functionalized or chiral monomers. The conditions required for polymerization in the carbodiimide-based reaction included catalysis by the 1:1 molecular complex formed by 4-(dimethylamino)pyridine and p-toluenesulfonic acid. These conditions were established through studies on a model system involving esterification of p-toluic acid and p-cresol. Self-condensation of several hydroxy acid monomers by this reaction has produced routinely good yields of polyesters with molecular weights greater than 15,000. It is believed that the high extents of reaction required for significant degrees of polymerization result from suppression of the side reaction leading to N-acylurea. The utility of this reaction in the formation of polar chains from sensitive monomers is demonstrated hereby the polycondensation of a chiral hydroxy acid.

  1. system at room temperature

    NASA Astrophysics Data System (ADS)

    Li, Shaoyuan; Ma, Wenhui; Zhou, Yang; Chen, Xiuhua; Xiao, Yongyin; Ma, Mingyu; Zhu, Wenjie; Wei, Feng

    2014-04-01

    In this paper, the moderately and lightly doped porous silicon nanowires (PSiNWs) were fabricated by the `one-pot procedure' metal-assisted chemical etching (MACE) method in the HF/H2O2/AgNO3 system at room temperature. The effects of H2O2 concentration on the nanostructure of silicon nanowires (SiNWs) were investigated. The experimental results indicate that porous structure can be introduced by the addition of H2O2 and the pore structure could be controlled by adjusting the concentration of H2O2. The H2O2 species replaces Ag+ as the oxidant and the Ag nanoparticles work as catalyst during the etching. And the concentration of H2O2 influences the nucleation and motility of Ag particles, which leads to formation of different porous structure within the nanowires. A mechanism based on the lateral etching which is catalyzed by Ag particles under the motivation by H2O2 reduction is proposed to explain the PSiNWs formation.

  2. Surface modification by electron irradiation for improved immunoassay

    NASA Astrophysics Data System (ADS)

    Safrany, Agnes; Deelder, André

    1999-08-01

    Polystyrene microtitration (ELISA) plates modified by electron beam irradiation were used for a monoclonal antibody based sandwich immunoassay for quantitation of circulating anodic antigen levels in Schistosoma-infected individuals. The plates irradiated with 15 kGy showed 2-4-fold lower detection level compared to untreated plates, and a 10-fold lower antibody coating concentration than usually used was still detectable. These results were reproducible and the modified surfaces were stable even after 2 years when kept at room temperature.

  3. Radiation resistant composite scintillators based on Al2O3:Ti grains and their properties after irradiation

    NASA Astrophysics Data System (ADS)

    Galunov, N. Z.; Gorbacheva, T. E.; Grinyov, B. V.; Karavaeva, N. L.; Khabuseva, S. U.; Krech, A. V.; Levchuk, L. G.; Litvinov, L. A.; Popov, V. F.; Sorokin, P. V.

    2017-09-01

    The effect of irradiation on the scintillation light output, optical transmittance, and luminescent spectra of composite scintillators based on single crystal grains of Al2O3:Ti, is studied. The dielectric gel Sylgard-184 is the base and the binder for the grains inside the composite scintillator. The paper presents and analyses the results obtained for the scintillators exposed by 10 MeV electrons from the linear electron accelerator at room temperature. For exposure doses at least up to D ∼ 550 Mrad when dose rate is 1500 Mrad/h and D ∼ 125 Mrad when dose rate is 0.2 Mrad/h the composite scintillators are radiation-resistant.

  4. Spectra of Surface Waves

    DTIC Science & Technology

    1989-03-22

    with a wave follower during Marsen. J. Gophysical Res. 88, 9844-9849. 11. Hughes, B.A., 1978. The effects on internal waves on surface waves : 2...Spectra of Surface Waves K. Watson March 1989 JSR-88-130 Approved for public release; distribution unlimited. DTIC SELECTE JUN0 11989 0 JASONE The...Arlington, VA 22209 8503Z 11. TITLE (hlde Secvfty Cof.kaftn) SPECTRA OF SURFACE WAVES (U) 12. PERSONAL AUTHOfRS) K. Watson 13a. TYPE OF REPORT 13b. TIME

  5. Recurarization in the recovery room.

    PubMed

    Albaladejo, P; Kinirons, B; Brocas, E; Benhamou, D; Samii, K

    1999-07-01

    A case of recurarization in the recovery room is reported. Accumulation of atracurium in the intravenous line led to recurarization after flushing the line in the recovery room. A respiratory arrest with severe desaturation and bradycardia occurred. Circumstances leading to this event and the mechanisms enabling a neuromuscular blockade to occur, following the administration of a small dose of relaxant, are discussed.

  6. Children and the Emergency Room

    ERIC Educational Resources Information Center

    Resnick, Rene; Hergenroeder, Elizabeth

    1975-01-01

    Describes a pilot study on emergency room treatment for children 3-13 years of age. The study focuses on children, parents, and their interactions under stress. Results indicate several areas of emergency room care which should be investigated and improved. (ED)

  7. XANES Analysis of Organic Residues Produced from the UV Irradiation of Astrophysical Ice Analogs

    NASA Technical Reports Server (NTRS)

    Nuevo, M.; Milam, S N.; Sandford, S A.; De Gregorio, B T.; Cody, G D.; Kilcoyne, A L.

    2011-01-01

    Organic residues formed in the laboratory from the ultraviolet (UV) photo-irradiation or ion bombardment of astrophysical ice analogs have been extensively studied for the last 15 years with a broad suite of techniques, including infrared (IR) and UV spectroscopies, as well as mass spectrometry. Analyses of these materials show that they consist of complex mixtures of organic compounds stable at room temperature, mostly soluble, that have not been fully characterized. However, the hydrolysis products of these residues have been partly identified using chromatography techniques, which indicate that they contain molecular precursors of prebiotic interest such as amino acids, nitrile-bearing compounds, and amphiphilic compounds. In this study, we present the first X-ray absorption near-edge structure (XANES) spectroscopy measurements of three organic residues made from the UV irradiation of ices having different starting compositions. XANES spectra confirm the presence of different chemical functions in these residues, and indicate that they are rich in nitrogenand oxygen-bearing species. These data can be compared with XANES measurements of extraterrestrial materials. Finally, this study also shows how soft X rays can alter the chemical composition of samples.

  8. XANES Analysis of Organic Residues Produced from the UV Irradiation of Astrophysical Ice Analogs

    NASA Technical Reports Server (NTRS)

    Nuevo, M.; Milam, S N.; Sandford, S A.; De Gregorio, B T.; Cody, G D.; Kilcoyne, A L.

    2011-01-01

    Organic residues formed in the laboratory from the ultraviolet (UV) photo-irradiation or ion bombardment of astrophysical ice analogs have been extensively studied for the last 15 years with a broad suite of techniques, including infrared (IR) and UV spectroscopies, as well as mass spectrometry. Analyses of these materials show that they consist of complex mixtures of organic compounds stable at room temperature, mostly soluble, that have not been fully characterized. However, the hydrolysis products of these residues have been partly identified using chromatography techniques, which indicate that they contain molecular precursors of prebiotic interest such as amino acids, nitrile-bearing compounds, and amphiphilic compounds. In this study, we present the first X-ray absorption near-edge structure (XANES) spectroscopy measurements of three organic residues made from the UV irradiation of ices having different starting compositions. XANES spectra confirm the presence of different chemical functions in these residues, and indicate that they are rich in nitrogenand oxygen-bearing species. These data can be compared with XANES measurements of extraterrestrial materials. Finally, this study also shows how soft X rays can alter the chemical composition of samples.

  9. Tuning of Schottky barrier height of Al/n-Si by electron beam irradiation

    NASA Astrophysics Data System (ADS)

    Vali, Indudhar Panduranga; Shetty, Pramoda Kumara; Mahesha, M. G.; Petwal, V. C.; Dwivedi, Jishnu; Choudhary, R. J.

    2017-06-01

    The effect of electron beam irradiation (EBI) on Al/n-Si Schottky diode has been studied by I-V characterization at room temperature. The behavior of the metal-semiconductor (MS) interface is analyzed by means of variations in the MS contact parameters such as, Schottky barrier height (ΦB), ideality factor (n) and series resistance (Rs). These parameters were found to depend on the EBI dose having a fixed incident beam of energy 7.5 MeV. At different doses (500, 1000, 1500 kGy) of EBI, the Schottky contacts were prepared and extracted their contact parameters by applying thermionic emission and Cheung models. Remarkably, the tuning of ΦB was observed as a function of EBI dose. The improved n with increased ΦB is seen for all the EBI doses. As a consequence of which the thermionic emission is more favored. However, the competing transport mechanisms such as space charge limited emission, tunneling and tunneling through the trap states were ascribed due to n > 1. The analysis of XPS spectra have shown the presence of native oxide and increased radiation induced defect states. The thickness variation in the MS interface contributing to Schottky contact behavior is discussed. This study explains a new technique to tune Schottky contact parameters by metal deposition on the electron beam irradiated n-Si wafers.

  10. Atomic Spectra Database (ASD)

    National Institute of Standards and Technology Data Gateway

    SRD 78 NIST Atomic Spectra Database (ASD) (Web, free access)   This database provides access and search capability for NIST critically evaluated data on atomic energy levels, wavelengths, and transition probabilities that are reasonably up-to-date. The NIST Atomic Spectroscopy Data Center has carried out these critical compilations.

  11. Quantum spectra and dynamics

    NASA Astrophysics Data System (ADS)

    Arce, Julio Cesar

    This work focuses on time-dependent quantum theory and methods for the study of the spectra and dynamics of atomic and molecular systems. Specifically, we have addressed the following two problems: (1) Development of a time-dependent spectral method for the construction of spectra of simple quantum systems. This includes the calculation of eigenenergies, the construction of bound and continuum eigenfunctions, and the calculation of photo cross-sections. Computational applications include the quadrupole photoabsorption spectra and dissociation cross-sections of molecular hydrogen from various vibrational states in its ground electronic potential-energy curve. This method is seen to provide an advantageous alternative, both from the computational and conceptual point of view, to existing standard methods. (2) Explicit time-dependent formulation of photoabsorption processes -- Analytical solutions of the time-dependent Schrodinger equation are constructed and employed for the calculation of probability densities, momentum distributions, fluxes, transition rates, expectation values and correlation functions. These quantities are seen to establish the link between the dynamics and the calculated, or measured, spectra and cross-sections, and to clarify the dynamical nature of the excitation, transition and ejection processes. Numerical calculations on atomic and molecular hydrogen corroborate and complement the previous results, allowing the identification of different regimes during the photoabsorption process.

  12. Quantum Spectra and Dynamics

    NASA Astrophysics Data System (ADS)

    Arce, Julio Cesar

    1992-01-01

    This work focuses on time-dependent quantum theory and methods for the study of the spectra and dynamics of atomic and molecular systems. Specifically, we have addressed the following two problems: (i) Development of a time-dependent spectral method for the construction of spectra of simple quantum systems--This includes the calculation of eigenenergies, the construction of bound and continuum eigenfunctions, and the calculation of photo cross-sections. Computational applications include the quadrupole photoabsorption spectra and dissociation cross-sections of molecular hydrogen from various vibrational states in its ground electronic potential -energy curve. This method is seen to provide an advantageous alternative, both from the computational and conceptual point of view, to existing standard methods. (ii) Explicit time-dependent formulation of photoabsorption processes --Analytical solutions of the time-dependent Schrodinger equation are constructed and employed for the calculation of probability densities, momentum distributions, fluxes, transition rates, expectation values and correlation functions. These quantities are seen to establish the link between the dynamics and the calculated, or measured, spectra and cross-sections, and to clarify the dynamical nature of the excitation, transition and ejection processes. Numerical calculations on atomic and molecular hydrogen corroborate and complement the previous results, allowing the identification of different regimes during the photoabsorption process.

  13. Observation of anharmonicity for copper thin film near room temperatures.

    PubMed

    Yang, D S

    2001-03-01

    The fluorescence EXAFS spectra for a copper thin film with a thickness of 3000A measured at 300K, 350K and 400K were analyzed by the regularization method to directly obtain the radial distribution. The pair distribution was almost symmetric for 300K but asymmetric for 350K and 400K. This indicates that the atoms in copper vibrate anharmonically near room temperatures. The anharmonicity and the skewness of the asymmetric distribu-tion increases as temperature increases.

  14. Magnetic Resonance Studies of Irradiated 1,3-DIMETHYLXANTHINE.

    NASA Astrophysics Data System (ADS)

    Majid, Ekramul

    ESR and ENDOR techniques were used to study the x-ray induced damage in single crystals of the organic molecule theophylline (1,3 dimethylxanthine). A K-band spectrometer operating at 25GHz was used for ESR and ENDOR measurements. X-irradiation was carried out at 25K, 80K, and at room temperature, and spectra were observed as the temperature was varied. The low temperature experiments were achieved by using a closed cycle helium refrigeration system. A detailed analysis was made of the spectra, and four different radicals (R1, R2, R3, and R4) were identified after irradiation. Radical R1 was identified as a hydrogen atom radical, stable from 20 to 60K; radical R2 was identified as an anion radical stable from 20 to 80K; radical R3 was formed by hydrogen abstraction from the methyl group at C(10); and radical R4 was found to be a hydrogen-adduct species. Radical R3 was characterized by the following parameters: (1) Methylene hydrogen hyperfine tensor values of 28.8, 17.8, 13.2 G, and 27.7, 18.9, 8.8 G; (2) g-tensor values of 2.0012, 2.0019, and 2.0036; (3) Isotropic methyl group coupling of 4 G; (4) A spin density of 0.68 on C(10). Radical R4 was characterized by (1) an isotropic methelene hydrogen coupling of 37.1 G; (2) a maximum nitrogen coupling at N(9) of 21 G; (3) hydrogen coupling tensor values, due to protonation at N(9), of 12.0, 8.5, and 3.0 G; (4) rotating methyl group tensor values, at N(1), of 2.38, 2.71, and 5.19 MHz; (5) g-tensor values of 2.0012, 2.0033, and 2.0049; (6) spin density of 0.38 on N(9). A kinetics study indicated that radical R3 converts to radical R4 at about 160 K.

  15. Magnetic resonance studies of irradiated 1,3-dimethylxanthine

    SciTech Connect

    Majid, E.

    1989-01-01

    ESR and ENDOR techniques were used to study the x-ray induced damage in single crystals of the organic molecule theophylline (1,3 dimethylxanthine). A K-band spectrometer operating at 25GHz was used for ESR and ENDOR measurements. X-irradiation was carried out at 25K, 80K, and at room temperature, and spectra were observed as the temperature was varied. The low temperature experiments were achieved by using a closed cycle helium refrigeration system. A detailed analysis was made of the spectra, and four different radicals (R1, R2, R3, and R4) were identified after irradiation. Radical R1 was identified as a hydrogen atom radical, stable from 20 to 6OK; radical R2 was identified as an anion radical stable from 20 to 8OK; radical R3 was formed by hydrogen abstraction from the methyl group at C(10); and radical R4 was found to be a hydrogen-adduct species. Radical R3 was characterized by the following parameters: (1) Methylene hydrogen hyperfine tensor values of 28.8, 17.8, 13.2 G, and 27.7, 18.9, 8.8 G; (2) g-tensor values of 2.0012, 2.0019, and 2.0036; (3) Isotropic methyl group coupling of 4 G; (4) A spin density of 0.68 on C(10). Radical R4 was characterized by (1) an isotropic methelene hydrogen coupling of 37.1 G; (2) a maximum nitrogen coupling at N(9) of 21 G; (3) hydrogen coupling tensor values, due to protonation at N(g), of 12.0, 8.5, and 3.0 G; (4) rotating methyl group tensor values, at N(l), of 2.38, 2.71, and 5.19 MHz; (5) g-tensor values of 2.0012, 2.0033, and 2.0049; (6) spin density of 0.38 on N(9). A kinetics study indicated that radical R3 converts to radical R4 at about 160 K.

  16. Graphitic carbon nanospheres: A Raman spectroscopic investigation of thermal conductivity and morphological evolution by pulsed laser irradiation

    SciTech Connect

    Agarwal, Radhe; Sahoo, Satyaprakash E-mail: rkatiyar@hpcf.upr.edu; Chitturi, Venkateswara Rao; Katiyar, Ram S. E-mail: rkatiyar@hpcf.upr.edu

    2015-12-07

    Graphitic carbon nanospheres (GCNSs) were prepared by a unique acidic treatment of multi-walled nanotubes. Spherical morphology with a narrow size distribution was confirmed by transmission electron microscopy studies. The room temperature Raman spectra showed a clear signature of D- and G-peaks at around 1350 and 1591 cm{sup −1}, respectively. Temperature dependent Raman scattering measurements were performed to understand the phonon dynamics and first order temperature coefficients related to the D- and G-peaks. The temperature dependent Raman spectra in a range of 83–473 K were analysed, where the D-peak was observed to show a red-shift with increasing temperature. The relative intensity ratio of D- to G-peaks also showed a significant rise with increasing temperature. Such a temperature dependent behaviour can be attributed to lengthening of the C-C bond due to thermal expansion in material. The estimated value of the thermal conductivity of GCNSs ∼0.97 W m{sup −1} K{sup −1} was calculated using Raman spectroscopy. In addition, the effect of pulsed laser treatment on the GCNSs was demonstrated by analyzing the Raman spectra of post irradiated samples.

  17. Graphitic carbon nanospheres: A Raman spectroscopic investigation of thermal conductivity and morphological evolution by pulsed laser irradiation

    NASA Astrophysics Data System (ADS)

    Agarwal, Radhe; Sahoo, Satyaprakash; Chitturi, Venkateswara Rao; Katiyar, Ram S.

    2015-12-01

    Graphitic carbon nanospheres (GCNSs) were prepared by a unique acidic treatment of multi-walled nanotubes. Spherical morphology with a narrow size distribution was confirmed by transmission electron microscopy studies. The room temperature Raman spectra showed a clear signature of D- and G-peaks at around 1350 and 1591 cm-1, respectively. Temperature dependent Raman scattering measurements were performed to understand the phonon dynamics and first order temperature coefficients related to the D- and G-peaks. The temperature dependent Raman spectra in a range of 83-473 K were analysed, where the D-peak was observed to show a red-shift with increasing temperature. The relative intensity ratio of D- to G-peaks also showed a significant rise with increasing temperature. Such a temperature dependent behaviour can be attributed to lengthening of the C-C bond due to thermal expansion in material. The estimated value of the thermal conductivity of GCNSs ˜0.97 W m-1 K-1 was calculated using Raman spectroscopy. In addition, the effect of pulsed laser treatment on the GCNSs was demonstrated by analyzing the Raman spectra of post irradiated samples.

  18. Commercial food irradiation

    SciTech Connect

    Black, E.F.; Libby, L.M.

    1983-06-01

    Food irradiation is discussed. Irradiation exposes food to gamma rays from a cobalt-60 or a cesium-137 source, or to high-energy electrons emitted by an electron accelerator. A major advantage is that food can be packaged either before or after treatment. FDA regulations with regard to irradiation are discussed. Comments on an 'Advance Notice' on irradiation, published by the FDA in 1981 are summarized.

  19. Bayesian inference approach to room-acoustic modal analysis

    NASA Astrophysics Data System (ADS)

    Henderson, Wesley; Goggans, Paul; Xiang, Ning; Botts, Jonathan

    2013-08-01

    Spectrum estimation is a problem common to many fields of physics, science, and engineering, and it has thus received a great deal of attention from the Bayesian data analysis community. In room acoustics, the modal or frequency response of a room is important for diagnosing and remedying acoustical defects. The physics of a sound field in a room dictates a model comprised of exponentially decaying sinusoids. Continuing in the tradition of the seminal work of Bretthorst and Jaynes, this work contributes an approach to analyzing the modal responses of rooms with a time-domain model. Room acoustic spectra are constructed of damped sinusoids, and the modelbased approach allows estimation of the number of sinusoids in the signal as well as their frequencies, amplitudes, damping constants, and phase delays. The frequency-amplitude spectrum may be most useful for characterizing a room, but in some settings the damping constants are of primary interest. This is the case for measuring the absorptive properties of materials, for example. A further challenge of the room acoustic spectrum problem is that modal density increases quadratically with frequency. At a point called the Schroeder frequency, adjacent modes overlap enough that the spectrum - particularly when estimated with the discrete Fourier transform - can be treated as a continuum. The time-domain, model-based approach can resolve overlapping modes and in some cases be used to estimate the Schroeder frequency. The proposed approach addresses the issue of filtering and preprocessing in order for the sampling to accurately identify all present room modes with their quadratically increasing density.

  20. 33. ROOM A (WEST ROOM) LOOKING SOUTHWEST. The windows above ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    33. ROOM A (WEST ROOM) LOOKING SOUTHWEST. The windows above the original Ministers' Gallery were raised in 1888 when inside toilet facilities were added on the other side of the west wall. Note the sloped window sills which provided more light. Also at the rear of the Meeting House a caretaker's apartment was added in 1908. - Twelfth Street Meeting House, 20 South Twelfth Street, Philadelphia, Philadelphia County, PA

  1. Optical Properties of Irradiated Topaz Crystals

    NASA Astrophysics Data System (ADS)

    Skvortsova, V.; Mironova-Ulmane, N.; Trinkler, L.

    2015-04-01

    The results of an investigation of UV-Visible absorption and photoluminescence spectra of colorless topaz before and after neutron irradiation, natural blue topaz from Ukraine, and yellow topaz are presented. We assume that the absorption band ∼ 620 nm and broad emission band 300-700 nm in topaz crystals are associated with exchange interaction between a radiation defect (anion vacancies, which capture one or two electrons) and impurity ions Cr3+, Fe3+ and Mn2+.

  2. Ionoluminescence of fused silica under swift ion irradiation

    NASA Astrophysics Data System (ADS)

    Saavedra, R.; Jiménez-Rey, D.; Martin, P.; Vila, R.

    2016-09-01

    Ion beam induced luminescence spectra have been in-situ recorded during He+ (2.5 MeV), O4+ (13.5 MeV) and Si4+ (24.4 MeV) irradiations for three vitreous silica grades with different OH content (KU1, KS-4V and Infrasil 301). Remarkable changes in the ionoluminescence spectra of the three silica grades were observed for low ion fluences. He+ irradiated samples exhibited higher luminescence than equivalent ones irradiated with heavier O4+ and Si4+ ions. KU1 samples with the highest OH content showed the lowest blue luminescence. Blue luminescence maximum during ion irradiations with O4+ and Si4+ ions is correlated with structural changes.

  3. Operating room design and its impact on operating room economics.

    PubMed

    Krupka, Dan C; Sandberg, Warren S

    2006-04-01

    Operating rooms are high-cost/high-revenue environments. In an era of rising costs and declining reimbursement, it is essential to optimize the effectiveness of the operating room suite, maximizing throughput of profitable cases while minimizing the costs of necessary, but unprofitable, procedures. Operating room management focuses on reducing wasted time in order to perform more cases in regular business hours, reduce overtime, or provide a better experience for staff and patients. It has been difficult to improve perioperative efficiency enough to reliably add cases during regular hours because the required time savings are so large, while most interventions can save only a few minutes per case. Recent work, however, has changed the basic paradigms for turning over operating rooms, dramatically reducing nonproductive time and increasing operating room throughput. In some situations, the additional expense required to achieve throughput improvements is more than offset by financial gains. Redesigning perioperative systems can increase operating room throughput, but not all case mixes benefit from the required additional resources. Thus hospitals should choose judiciously if, and to what degree, high throughput environments are implemented. Once implemented, access to these environments can be used as an incentive for improved surgical performance.

  4. Toward understanding dynamic annealing processes in irradiated ceramics

    NASA Astrophysics Data System (ADS)

    Myers, Michael Thomas

    High energy particle irradiation inevitably generates defects in solids in the form of collision cascades. The ballistic formation and thermalization of cascades occur rapidly and are believed to be reasonably well understood. However, knowledge of the evolution of defects after damage cascade thermalization, referred to as dynamic annealing, is quite limited. Unraveling the mechanisms associated with dynamic an- nealing is crucial since such processes play an important role in the formation of stable post-irradiation disorder in ion-beam-processed semiconductors and determines the "radiation tolerance" of many nuclear materials. The purpose of this dissertation is to further our understanding of the processes involved in dynamic annealing. In order to achieve this, two main tasks are undertaken. First, the effects of dynamic annealing are investigated in ZnO, a technologically relevant material that exhibits very high dynamic defect annealing at room temper- ature. Such high dynamic annealing leads to unusual defect accumulation in heavy ion bombarded ZnO. Through this work, the puzzling features that were observed more than a decade ago in ion-channeling spectra have finally been explained. We show that the presence of a polar surface substantially alters damage accumulation. Non-polar surface terminations of ZnO are shown to exhibit enhanced dynamic an- nealing compared to polar surface terminated ZnO. Additionally, we demonstrate one method to reduce radiation damage in polar surface terminated ZnO by means of a surface modification. These results advance our efforts in the long-sought-after goal of understanding complex radiation damage processes in ceramics. Second, a pulsed-ion-beam method is developed and demonstrated in the case of Si as a prototypical non-metallic target. Such a method is shown to be a novel experimental technique for direct extraction of dynamic annealing parameters. The relaxation times and effective diffusion lengths of mobile defects

  5. Parmeterization of spectra

    NASA Technical Reports Server (NTRS)

    Cornish, C. R.

    1983-01-01

    Following reception and analog to digital conversion (A/D) conversion, atmospheric radar backscatter echoes need to be processed so as to obtain desired information about atmospheric processes and to eliminate or minimize contaminating contributions from other sources. Various signal processing techniques have been implemented at mesosphere-stratosphere-troposphere (MST) radar facilities to estimate parameters of interest from received spectra. Such estimation techniques need to be both accurate and sufficiently efficient to be within the capabilities of the particular data-processing system. The various techniques used to parameterize the spectra of received signals are reviewed herein. Noise estimation, electromagnetic interference, data smoothing, correlation, and the Doppler effect are among the specific points addressed.

  6. Thermal conductivity degradation of graphites irradiated at low temperature

    SciTech Connect

    Snead, L.L.; Burchell, T.D.

    1995-04-01

    The objective of this work is to study the thermal conductivity degradation of new, high thermal conductivity graphites and to compare these results to more standard graphites irradiated at low temperatures. Several graphites and graphite composites (C/C`s) have been irradiated near 150{degree}C and at fluences up to a displacement level of 0.24 dpa. The materials ranged in unirradiated room temperature thermal conductivity of these materials varied from 114 W/m-K for H-451 isotropic graphite, to 670 W/m-K for unidirectional FMI-1D C/C composite. At the irradiation temperature a saturation reduction in thermal conductivity was seen to occur at displacement levels of approximately 0.1 dpa. All materials were seen to degrade to approximately 10 to 14 % of their original thermal conductivity after irradiation. The effect of post irradiation annealing on the thermal conductivity was also studied.

  7. Features of the uniaxial elastic deformation of X-ray-irradiated p-Si crystals

    SciTech Connect

    Pavlyk, B. V.; Lys, R. M. Didyk, R. I.; Shykorjak, J. A.

    2015-05-15

    Changes in the conductivity of p-Si single-crystals irradiated at room temperature during their mechanical compression and stress relief are studied. It is shown that irradiation is accompanied by the generation of point defects in silicon, which play the role of stoppers for dislocation motion. The effect of “radiation memory” in “electronic” silicon crystals is detected.

  8. Directional Ocean Wave Spectra

    DTIC Science & Technology

    1991-01-01

    of Ocean Waves: Some Observations from R. K. Raney and LIMEX/LEWEX 󈨛 P. W, Vachon 104 Directional Spectra from the CCRS C-Band SAR during LEWEX P...11. Vachon , A. S. Bhogal, and i%’. G. Freeman I10 SAR Scattering Mechanisms as Inferred from LEWEX D. G, Tiller Spectral Intercomparisons 117...Duiring her stay. Michelle Champagne- on time scales usually recommended to define the mean. Philippe explored some of the aspects ofthe ’sind %aniahilits

  9. Barnacle Bill Spectra

    NASA Technical Reports Server (NTRS)

    1997-01-01

    These IMP spectra show the characteristics of the rock surface measured by the Alpha Proton X-Ray Spectrometer (blue), the soil trapped in pits on the rock surface (red), and the deposit of bright drift on the top of the rock. The area measured by the APXS has the properties expected for nearly unweathered igneous rock, and the soil trapped in the pits is intermediate to the unweathered rock and the highly weathered drift material.

  10. 32 CFR 518.9 - Reading room.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 3 2013-07-01 2013-07-01 false Reading room. 518.9 Section 518.9 National... RELATIONS THE FREEDOM OF INFORMATION ACT PROGRAM FOIA Reading Rooms § 518.9 Reading room. (a) Reading room... the records described, DA may elect to place other records in their reading room, and also make...

  11. 32 CFR 518.9 - Reading room.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 3 2011-07-01 2009-07-01 true Reading room. 518.9 Section 518.9 National... RELATIONS THE FREEDOM OF INFORMATION ACT PROGRAM FOIA Reading Rooms § 518.9 Reading room. (a) Reading room... the records described, DA may elect to place other records in their reading room, and also make...

  12. Infrared transmission spectra of Sea of Fertility regolith

    NASA Technical Reports Server (NTRS)

    Akhmanova, M. V.; Karyakin, A. V.; Tartasov, L. S.

    1974-01-01

    Transmission spectra in the 2-25 micrometer region were obtained for samples of lunar regolith returned by the Luna 16 automatic station. A comparison of the Luna 16, Apollo 11, and Apollo 12 samples showed that the infrared transmission spectra of regolith samples from the mare regions are similar and characteristic of basic basaltic rocks. The absorption bands show up in the vibration region of the SiO4 groups. No water and OH groups were found in the samples based on the spectrum. Spectra of regolith samples calcined at 1000C showed changes that can be interpreted as changes in the spectra of irradiated crystals (especially distinctly for the Luna 16 samples).

  13. Pattern recognition in spectra

    NASA Astrophysics Data System (ADS)

    Gebran, M.; Paletou, F.

    2017-06-01

    We present a new automated procedure that simultaneously derives the effective temperature Teff, surface gravity log g, metallicity [Fe/H], and equatorial projected rotational velocity ve sin i for stars. The procedure is inspired by the well-known PCA-based inversion of spectropolarimetric full-Stokes solar data, which was used both for Zeeman and Hanle effects. The efficiency and accuracy of this procedure have been proven for FGK, A, and late type dwarf stars of K and M spectral types. Learning databases are generated from the Elodie stellar spectra library using observed spectra for which fundamental parameters were already evaluated or with synthetic data. The synthetic spectra are calculated using ATLAS9 model atmospheres. This technique helped us to detect many peculiar stars such as Am, Ap, HgMn, SiEuCr and binaries. This fast and efficient technique could be used every time a pattern recognition is needed. One important application is the understanding of the physical properties of planetary surfaces by comparing aboard instrument data to synthetic ones.

  14. Spectra of Hot Cores

    NASA Astrophysics Data System (ADS)

    Chakrabarti, S.; McKee, C. F.

    2003-12-01

    The turbulent core model for massive star formation (McKee & Tan 2002) generalizes the standard isothermal collapse model for low-mass stars to include turbulent pressure support. This model predicts reasonable massive star formation times of order 105 years, which is short enough to overcome the radiation pressure of the newly formed star. We calculate the millimeter and infrared spectrum predicted by the turbulent core model and compare with observations of several hot molecular cores. We consider spherically symmetric dust envelopes and use DUSTY, a 1-D radiative transfer code (Ivezic, Nenkova, Elitzur 1997), to numerically calculate the SEDs of these hot cores. We also analytically calculate the spectra in the asymptotic regions of low and high frequency and join these asymptotic forms smoothly by a fitting function that minimizes the relative error between the analytic and numerical spectra. Thus, we are able to express the functional dependence of the spectra of hot cores in terms of the dynamical variables of any given collapse model. This approach allows us to use observed SEDs as a diagnostic tool in inferring physical conditions in these cores.

  15. Welding irradiated stainless steel

    SciTech Connect

    Kanne, W.R. Jr.; Chandler, G.T.; Nelson, D.Z.; Franco-Ferreira, E.A.

    1993-12-31

    Conventional welding processes produced severe underbead cracking in irradiated stainless steel containing 1 to 33 appm helium from n,a reactions. A shallow penetration overlay technique was successfully demonstrated for welding irradiated stainless steel. The technique was applied to irradiated 304 stainless steel that contained 10 appm helium. Surface cracking, present in conventional welds made on the same steel at the same and lower helium concentrations, was eliminated. Underbead cracking was minimal compared to conventional welding methods. However, cracking in the irradiated material was greater than in tritium charged and aged material at the same helium concentrations. The overlay technique provides a potential method for repair or modification of irradiated reactor materials.

  16. [Study on THz spectra of nicotinic acid, nicotinamide and nicotine].

    PubMed

    Yu, Bin; Huang, Zhen; Wang, Xiao-yan; Zhao, Guo-zhong

    2009-09-01

    The terahertz (THz) spectra of nicotinic acid, nicotinamide and nicotine were studied at room temperature. The time-domain THz spectra were measured. The frequency-domain spectra were obtained by fast Fourier transform (FFT). The spectral response and the dispersive relationship of refractive index in THz spectral range were obtained. The results show that the samples have obvious spectral response in THz spectral range except nicotine. The corresponding stimulated spectra were given by using density functional theory (DFT) method for both nicotinamide and nicotinic acid. The origin of the absorption peaks of nicotinic acid and nicotinamide was explored. It is thought that the absorption peak of nicotinic acid is caused by the torsion and wagging of the molecule, but the absorption peaks of nicotinamide (except 1.93 THz) are caused by intermolecular or phonon mode. It was shown that the molecule structure and vibrational modes of nicotinic acid and nicotinamide can be analyzed by the combination of simulation and experimental results.

  17. What's New in Locker Rooms?

    ERIC Educational Resources Information Center

    Rittner-Heir, Robbin M.

    2001-01-01

    Discusses athletic facility design and renovation issues that exist because of increasing numbers of female athletes. Outlines renovation issues such as locker room facilities, space for sports equipment, and additional athletic fields. (GR)

  18. Low temperature intrinsic defects in x-irradiated hydroxyapatite synthetic single crystals

    SciTech Connect

    Close, D.M.; Mengeot, M.; Gilliam, O.R.

    1981-05-15

    ESR studies of radiation-induced defects have been conducted on synthetic calcium hydroxyapatite single crystals. For a room temperature x-irradiation a major defect (labeled A) was reported to be an O/sup -/ ion. X irradiation at 6 K shows defect A, trapped atomic hydrogen, and a nonaxial holelike center (labeled I). These new centers are stable at 6 K but anneal near 77 K. Observations at 9 and 35 GHz indicate that the I center is a spin-1/2 defect located in six inequivalent sites. In the ab plane, spectra exhibit an isotropic hyperfine doublet (approx.13 G splitting) and an anisotropic doublet (17--27 G splitting) in three symmetry-related sites. For other orientations additional site splitting and ''forbidden transitions'' make the spectra very complex. The hyperfine coupling tensor for the anisotropic doublet has diagonal elements -29.5, -19.2, and +3.11 G. The g tensor for this defect has diagonal elements 2.0068, 2.0032, and 2.0148. The sets of directional cosines associated with the minimum g value and the intermediate A value each indicate a direction corresponding approximately to that of the vector from an OH oxygen to a neighboring PO/sub 4//sup 3 -/ oxygen. The model proposed for the I center is a hole trapped by both an OH/sup -/ and a neighboring PO/sub 4//sup 3 -/. The anisotropic doublet is accounted for with 65% of the spin density on OH/sup -/. The remaining spin density is on a phosphate oxygen. This creates a PO/sup 2 -//sub 4/ defect with the isotropic coupling arising from hyperfine interaction with the /sup 31/P nucleus.

  19. Ion irradiation-induced swelling and hardening effect of Hastelloy N alloy

    NASA Astrophysics Data System (ADS)

    Zhang, S. J.; Li, D. H.; Chen, H. C.; Lei, G. H.; Huang, H. F.; Zhang, W.; Wang, C. B.; Yan, L.; Fu, D. J.; Tang, M.

    2017-06-01

    The volumetric swelling and hardening effect of irradiated Hastelloy N alloy were investigated in this paper. 7 MeV and 1 MeV Xe ions irradiations were performed at room temperature (RT) with irradiation dose ranging from 0.5 to 27 dpa. The volumetric swelling increases with increasing irradiation dose, and reaches up to 3.2% at 27 dpa. And the irradiation induced lattice expansion is also observed. The irradiation induced hardening initiates at low ion dose (≤1dpa) then saturates with higher ion dose. The irradiation induced volumetric swelling may be ascribed to excess atomic volume of defects. The irradiation induced hardening may be explained by the pinning effect where the defects can act as obstacles for the free movement of dislocation lines. And the evolution of the defects' size and number density could be responsible for the saturation of hardness.

  20. Tensile properties of CLAM steel irradiated up to 20.1 dpa in STIP-V

    NASA Astrophysics Data System (ADS)

    Ge, Hongen; Peng, Lei; Dai, Yong; Huang, Qunying; Ye, Minyou

    2016-01-01

    Specimens of China low activation martensitic steel (CLAM) were irradiated in the fifth experiment of SINQ Target Irradiation Program (STIP-V) up to 20.1 dpa/1499 appm He/440 °C. Tensile tests were performed at room temperature (R.T) and irradiation temperatures (Tirr) in the range of 25-450 °C. The tensile results demonstrated strong effect of irradiation dose and irradiation temperature on hardening and embrittlement. With Tirr below ˜314 °C, CLAM steel specimens tested at R.T and Tirr showed similar evolution trend with irradiation dose, compared to other reduced activation ferritic/martensitic (RAFM) steels in similar irradiation conditions. At higher Tirr above ˜314 °C, it is interesting that the hardening effect decreases and the ductility seems to recover, probably due to a strong effect of high irradiation temperature.

  1. Nuclear reactor control room construction

    DOEpatents

    Lamuro, Robert C.; Orr, Richard

    1993-01-01

    A control room 10 for a nuclear plant is disclosed. In the control room, objects 12, 20, 22, 26, 30 are no less than four inches from walls 10.2. A ceiling 32 contains cooling fins 35 that extend downwards toward the floor from metal plates 34. A concrete slab 33 is poured over the plates. Studs 36 are welded to the plates and are encased in the concrete.

  2. Nuclear reactor control room construction

    DOEpatents

    Lamuro, R.C.; Orr, R.

    1993-11-16

    A control room for a nuclear plant is disclosed. In the control room, objects labelled 12, 20, 22, 26, 30 in the drawing are no less than four inches from walls labelled 10.2. A ceiling contains cooling fins that extend downwards toward the floor from metal plates. A concrete slab is poured over the plates. Studs are welded to the plates and are encased in the concrete. 6 figures.

  3. Ferromagnetism in proton irradiated 4H-SiC single crystal

    SciTech Connect

    Zhou, Ren-Wei; Wang, Hua-Jie; Chen, Wei-Bin; Li, Fei; Liu, Xue-Chao Zhuo, Shi-Yi; Shi, Er-Wei

    2015-04-15

    Room-temperature ferromagnetism is observed in proton irradiated 4H-SiC single crystal. An initial increase in proton dose leads to pronounced ferromagnetism, accompanying with obvious increase in vacancy concentration. Further increase in irradiation dose lowers the saturation magnetization with the decrease in total vacancy defects due to the defects recombination. It is found that divacancies are the mainly defects in proton irradiated 4H-SiC and responsible for the observed ferromagnetism.

  4. The 'Room within a Room' Concept for Monitored Warhead Dismantlement

    SciTech Connect

    Tanner, Jennifer E.; Benz, Jacob M.; White, Helen; McOmish, Sarah; Allen, Keir; Tolk, Keith; Weeks, George E.

    2014-12-01

    Over the past 10 years, US and UK experts have engaged in a technical collaboration with the aim of improving scientific and technological abilities in support of potential future nuclear arms control and non-proliferation agreements. In 2011 a monitored dismantlement exercise provided an opportunity to develop and test potential monitoring technologies and approaches. The exercise followed a simulated nuclear object through a dismantlement process and looked to explore, with a level of realism, issues surrounding device and material monitoring, chain of custody, authentication and certification of equipment, data management and managed access. This paper focuses on the development and deployment of the ‘room-within-a-room’ system, which was designed to maintain chain of custody during disassembly operations. A key challenge for any verification regime operating within a nuclear weapon complex is to provide the monitoring party with the opportunity to gather sufficient evidence, whilst protecting sensitive or proliferative information held by the host. The requirement to address both monitoring and host party concerns led to a dual function design which: • Created a controlled boundary around the disassembly process area which could provide evidence of unauthorised diversion activities. • Shielded sensitive disassembly operations from monitoring party observation. The deployed room-within-a-room was an integrated system which combined a number of chain of custody technologies (i.e. cameras, tamper indicating panels and enclosures, seals, unique identifiers and radiation portals) and supporting deployment procedures. This paper discusses the bounding aims and constraints identified by the monitoring and host parties with respect to the disassembly phase, the design of the room-within-a-room system, lessons learned during deployment, conclusions and potential areas of future work. Overall it was agreed that the room-within-a-room approach was effective but

  5. Low Temperature Reflectance Spectra of Titan Tholins

    NASA Technical Reports Server (NTRS)

    Roush, T. L.; Dalton, J. B.; Fonda, Mark (Technical Monitor)

    2001-01-01

    Compositional interpretation of remotely obtained reflectance spectra of outer solar system surfaces is achieved by a variety of methods. These include matching spectral curves, matching spectral features, quantitative spectral interpretation, and theoretical modeling of spectra. All of these approaches rely upon laboratory measurements of one kind or another. The bulk of these laboratory measurements are obtained with the sample of interest at ambient temperatures and pressures. However, surface temperatures of planets, satellites, and asteroids in the outer solar system are significantly cooler than ambient laboratory conditions on Earth. The infrared spectra of many materials change as a function of temperature. As has been recently demonstrated it is important to assess what effects colder temperatures have on spectral properties and hence, compositional interpretations. Titan tholin is a solid residue created by energetic processing of H-, C-, and N-bearing gases. Such residues can also be created by energetic processing if the gases are condensed into ices. Titan tholin has been suggested as a coloring agent for several surfaces in the outer solar system. Here we report laboratory measurements of Titan tholin at a temperature of 100 K and compare these to measurements of the same sample near room temperature. At low temperature the absorption features beyond 1 micrometer narrow slightly. At wavelengths greater than approx. 0.8 micrometer the overall reflectance of the sample decreases slightly making the sample less red at low temperatures. We will discuss the implications of the laboratory measurements for interpretation of cold outer solar system surfaces.

  6. Decomposition of beta-ray induced ESR spectra of fossil tooth enamel

    NASA Astrophysics Data System (ADS)

    Joannes-Boyau, Renaud; Grün, Rainer

    2011-03-01

    Two fossil tooth enamel fragments were irradiated with beta rays, one through the outer surface, the other through the dentine-enamel junction. The angular ESR spectra of the two fragments were decomposed using an automated simulated annealing (SA) procedure, which is particularly well suited to separate overlapping signals. Beta irradiation generated different qualitative and quantitative responses to previous gamma irradiation experiments. Similar to gamma rays, the beta irradiation created both non-oriented and oriented CO2- radicals. In contrast to gamma irradiation, which only created orthorhombic oriented CO2- radicals, both axial and orthorhombic CO2- radicals were extracted after beta irradiation. Furthermore, gamma irradiation created significantly more non-oriented radicals than beta irradiation. Altogether, the radical distribution created by beta irradiation resembled that of the natural sample, which had been exposed to environmental irradiation over several hundreds of thousands of years. The natural sample contained 9% non-orientated CO2- radicals and a mix of orthorhombic to axial CO2- radicals in the ratio of 35:65. The beta induced spectra of the fragment irradiated through the outer surface contained 9% non-orientated CO2- radicals and a mix of orthorhombic to axial CO2- radicals in the ratio of 45:55, while for the other sample these values were 19% and 59:41, respectively. The angle between the axial and orthorhombic CO2- radicals is around 23° in both natural and beta irradiation components. This indicates that the radicals produced by the different irradiation modes are located in the same positions in the hydroxyapatite crystals. The higher percentage of non-oriented CO2- radicals closer to the dentine-enamel junction points to interprismatic zones for their possible location.

  7. Raman spectra of solid benzene under high pressure

    NASA Technical Reports Server (NTRS)

    Thiery, M.-M.; Kobashi, K.; Spain, I. L.

    1985-01-01

    Raman spectra of solid benzene have been measured at room temperature up to about 140 kbar, using the diamond anvil cell. Effort has been focused upon the lattice vibration spectra at pressures above that of phase II. It is found that a change in slopes occurs in the frequency-pressure curves at about 40 kbar. Furthermore, a new band appears above 90 kbar. These features probably correspond respectively to the II-III phase transition, which has been reported previously, and a III-IV phase transition, reported here for the first time.

  8. Effect of pressure on infrared spectra of ice 7

    NASA Technical Reports Server (NTRS)

    Holzapfel, W. B.; Seiler, B.; Nicol, M.

    1983-01-01

    The effect of pressure on the infrared spectra of H2O and D2O ice VII was studied at room temperature and pressures between 2 and 15 GPa with a Fourier transform infrared spectrometer and a diamond anvil high pressure cell. Two librational modes, one bending mode, and various overtone bands are well resolved. The stretching modes, nu sub 1 and nu sub 3 are poorly resolved due to overlap with diamond window absorption. Differences between the spectra of H2O and D2O are discussed.

  9. Effect of pressure on infrared-spectra of ice VII

    NASA Technical Reports Server (NTRS)

    Holzapfel, W. B.; Seiler, B.; Nicol, M.

    1984-01-01

    The effect of pressure on the infrared spectra of H20 and D20 ice VII was studied at room temperature and at pressures between 2 and 15 GPa with a Fourier transform infrared spectrometer and a diamond anvil high pressure cell. Two librational modes, one bending mode, and various overtone bands are well resolved. The stretching modes, nu sub 1 and nu sub 3, are poorly resolved due to overlap with diamond window absorption. Differences between the spectra of H20 and D20 are discussed. Previously announced in STAR as N83-23671

  10. Determinations of Photon Spectra

    DTIC Science & Technology

    1989-01-01

    COVERED O14. DATE OF REPORT (Year, Month, Day) 115. PAGE COUNT THESIS/ftFROW*W FROM TO 1989 1 54 16. SUPPLEMENTARY NOTATION A ?RQVk;U kOR 3UB LIC RELEASE...IAW AFR 190- 1 ERNEST A. HAYGOOD, 1st Lt, USAF Executive Officer, Civilian Institution ProQrams 17. COSATI CODES 18. SUBJECT TERMS (Continue on...spectra from measurements obtained with a sodium iodide counting system. A response matrix is computed by combining photon cross sections with

  11. A code to simulate nuclear reactor inventories and associated gamma-ray spectra.

    PubMed

    Cresswell, A J; Allyson, J D; Sanderson, D C

    2001-01-01

    A computer code has been developed to simulate the gamma-ray spectra that would be measured by airborne gamma spectrometry (AGS) systems from sources containing short-lived fission products. The code uses simple numerical methods to simulate the production and decay of fission products and generates spectra for sodium iodide (NaI) detectors using Monte Carlo codes. A new Monte Carlo code using a virtual array of detectors to reduce simulation times for airborne geometries is described. Spectra generated for a short irradiation and laboratory geometry have been compared with an experimental data set. The agreement is good. Spectra have also been generated for airborne geometries and longer irradiation periods. The application of this code to generate AGS spectra for accident scenarios and their uses in the development and evaluation of spectral analysis methods for such situations are discussed.

  12. ESR identification of gamma-irradiated albendazole

    NASA Astrophysics Data System (ADS)

    Çolak, Seyda

    2010-01-01

    The use of ionizing radiation for sterilization of pharmaceuticals is a well-established technology. In the present work, the spectroscopic and kinetic features of the radicals induced in gamma-irradiated solid albendazole samples is investigated at different temperatures in the dose range of 3-34 kGy by electron spin resonance (ESR) spectroscopy. Irradiation with gamma radiation produced two different radical species in albendazole. They were fairly stable at room temperature but relatively unstable above room temperature, giving rise to an unresolved ESR spectrum consisting of three resonance peaks centered at g=2.0057. Decay activation energies of the contributing radical species were calculated to be 47.8 (±13.5) and 50.5 (±9.7) kJ/mol using the signal intensity decay data derived from annealing studies performed at high temperatures. A linear function of the applied dose was found to best describe the experimental dose-response data. Albendazole does not present the characteristics of good dosimetric materials. However, the discrimination of irradiated albendazole from its unirradiated form was possible even 6 months after storage in normal conditions. Based on these findings, it is concluded that albendazole and albendazole-containing drugs can be safely sterilized by gamma radiation and that ESR spectroscopy could be successfully used as a potential technique for monitoring their radiosterilization.

  13. X-ray-induced Cu deposition and patterning on insulators at room temperature.

    PubMed

    Hsu, Pei-Cheng; Chen, Yu-Sheng; Hwu, Yeukuang; Je, J H; Margaritondo, G; Tok, Eng Soon

    2015-11-01

    X-ray irradiation is shown to trigger the deposition of Cu from solution, at room temperature, on a wide variety of insulating substrates: glass, passivated Si, TiN/Ti/SiO2/Si and photoresists like PMMA and SU-8. The process is suitable for patterning and the products can be used as seeds for electroplating of thicker overlayers.

  14. Room-temperature synthesis of soluble, fluorescent carbon nanoparticles from organogel precursors.

    PubMed

    Néabo, Jules Roméo; Vigier-Carrière, Cécile; Rondeau-Gagné, Simon; Morin, Jean-François

    2012-10-18

    Carbon nanoparticles were obtained at room temperature by irradiating an organogel made from a 1,8-diaryloctatetrayne derivative in chloroform. During the topochemical polymerization, the morphology of the gel changes from fibers to soluble, yellow fluorescent nanoparticles in high yield. Analyses suggest that the resulting nanoparticles are made of amorphous graphitic carbon.

  15. [Identification of irradiated abalone by ESR spectroscopy].

    PubMed

    Song, Yeping; Wang, Chuanxian; Yang, Zhenyu; Zhong, Weike; Geng, Jinpei; Lu, Di; Ding, Zhuoping

    2012-05-01

    To establish an analytical method for the detection and identification of irradiated abalone by electron spin resonance spectroscopy. Electron spin resonance (ESR) was used to study the spectral characteristics of abalone and the characteristic peak for quantitation. There were obvious different ESR spectra between unirradiated and irradiated abalone. The g factor for unirradiated abalone was 2.0055-2.0060, the g1 and g2 factor for irradiated abalone were (2.0027 +/- 0.0001) and (1.9994 +/- 0.0001), respectively. The ESR signal intensity of characteristic peak was positively correlated with absorbed dose in the range of 0.5 - 10 kGy, left peak was the characteristic peak for quantitation and the detection limit was < or = 0.5 kGy. It was difficult to quantitate when the absorbed dose was over 10 kGy. ESR characteristic peak and g factor were able to qualitatively determine the irradiation of abalone. ESR spectroscopy is an effective method to determine whether the abalone being irradiated or not.

  16. Theoretical Studies of Molecular Spectra

    NASA Technical Reports Server (NTRS)

    McKay, Christopher (Technical Monitor); Freedman, Richard S.

    2002-01-01

    This summary describes the research activities of the principal investigator during the reporting period. The research includes spectroscopy, management of molecular databases, and generation of spectral line profiles and opacity data. The spectroscopy research includes oxygen broadening of nitric oxide (NO), analysis of CO2 spectra, analysis of HNO3 spectra, and analysis of CO spectra.

  17. 26. A typical outer rod room, or rack room, showing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    26. A typical outer rod room, or rack room, showing the racks for the nine horizontal control rods (HCRs) that would be inserted or withdrawn from the pile to control the rate of reaction. In this case, it is the 105-F Reactor in February 1945. The view is looking away from the pile, which is out of the picture on the left. Several of the cooling water hose reels for the rods can be seen at the end of the racks near the wall. D-8323 - B Reactor, Richland, Benton County, WA

  18. Control spectra for Quito

    NASA Astrophysics Data System (ADS)

    Aguiar, Roberto; Rivas-Medina, Alicia; Caiza, Pablo; Quizanga, Diego

    2017-03-01

    The Metropolitan District of Quito is located on or very close to segments of reverse blind faults, Puengasí, Ilumbisí-La Bota, Carcelen-El Inca, Bellavista-Catequilla and Tangahuilla, making it one of the most seismically dangerous cities in the world. The city is divided into five areas: south, south-central, central, north-central and north. For each of the urban areas, elastic response spectra are presented in this paper, which are determined by utilizing some of the new models of the Pacific Earthquake Engineering Research Center (PEER) NGA-West2 program. These spectra are calculated considering the maximum magnitude that could be generated by the rupture of each fault segment, and taking into account the soil type that exists at different points of the city according to the Norma Ecuatoriana de la Construcción (2015). Subsequently, the recurrence period of earthquakes of high magnitude in each fault segment is determined from the physical parameters of the fault segments (size of the fault plane and slip rate) and the pattern of recurrence of type Gutenberg-Richter earthquakes with double truncation magnitude (Mmin and Mmax) is used.

  19. Radiation stability of some room temperature ionic liquids

    NASA Astrophysics Data System (ADS)

    Jagadeeswara Rao, Ch.; Venkatesan, K. A.; Tata, B. V. R.; Nagarajan, K.; Srinivasan, T. G.; Vasudeva Rao, P. R.

    2011-05-01

    Radiation stability of some room temperature ionic liquids (RTILs) that find useful electrochemical applications in nuclear fuel cycle has been evaluated. The ionic liquids such as protonated betaine bis(trifluoromethylsulfonyl)imide (HbetNTf 2), aliquat 336 (tri-n-octlymethylammonium chloride), 1-butyl-3-methylimidazolium chloride (bmimCl), 1-hexyl-3-methylimidazolium chloride (hmimCl), N-butyl-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (BMPyNTf 2) and N-methyl-N-propylpiperidinium bis(trifluoromethylsulfonyl)imide (MPPiNTf 2) have been irradiated to various absorbed dose levels, up to 700 kGy. The effect of gamma radiation on these ionic liquids has been evaluated by determining the variations in the physical properties such as color, density, viscosity, refractive index and electrochemical window. The changes in density, viscosity and refractive index of these ionic liquids upon irradiation were insignificant; however, the color and electrochemical window varied significantly with increase of absorbed dose.

  20. The Effect of Temperature on Reflectance of Materials Space Weathered by Laser Irradiation: Implications for Increased Albedo Measured by LOLA

    NASA Astrophysics Data System (ADS)

    Corley, L. M.; Gillis-Davis, J.; Lucey, P. G.; Trang, D.

    2016-12-01

    Space weathering significantly changes the optical properties of airless planetary bodies, resulting in decreased albedo, spectral reddening, and subdued absorption bands. These optical changes are caused by the presence of submicroscopic iron (SMFe) in agglutinates and patina glass, which is observed in lunar soils returned by the Apollo and Luna missions. Micrometeorite impacts and solar wind irradiation are key processes that produce SMFe. The Lunar Orbiter Laser Altimeter (LOLA) onboard the Lunar Reconnaissance Orbiter measured a trend of increased albedo at 1064 nm with decreasing temperature and a spike in 1064-nm albedo in permanently shadowed regions (PSRs). Although the LOLA albedo increase could be due to the presence of ice, increased reflectance is also consistent with reduced space weathering. It is currently unknown how temperature influences the production of SMFe and the resulting spectral effects. Low temperatures of polar regions and PSRs (as low as 50K) may affect the volume of impact melt/vaporization produced and the subsequent development of SMFe. To test this hypothesis we compare visible to near-infrared (VNIR) reflectance spectra of materials laser space weathered at low temperature and room temperature. Olivine irradiated at 88K is brighter at 1064 nm and exhibits less reddening than olivine irradiated at 295K. Radiative transfer modeling provided abundance estimates for SMFe. Based on these estimates, olivine irradiated at 88K contains 65-70% the abundance of SMFe of olivine irradiated at 295K. Laser weathering of a highlands analog at 85K results in reduced reddening but does not yield a statistically significant increased brightness at 1064 nm with lower temperature. Hence, our results show that laser weathering at low temperatures produces a measurable effect in VNIR spectra for olivine and less so for a plagioclase dominated soil. We attribute this mineral dependent observation to a decrease in the production of SMFe, and we will

  1. Pyrolytic carbon free-radical evolution and irradiation damage of polyimide under low-energy proton irradiation

    SciTech Connect

    Sun Chengyue; Wu Yiyong; Xiao Jingdong; Li Ruifeng; Yang Dezhuang; He Shiyu

    2011-12-15

    Ionization and displacement effects are basic phenomena in damage processes of materials under space-particle irradiation. In this paper, the damage behaviors were investigated on the polyimide under proton irradiation using electron paramagnetic resonance (EPR) spectra analysis and optical absorbance valuation. The results indicate that the proton irradiation induces the formation of pyrolytic carbon free-radical with a g value of 2.0025, and the population of free radicals increases with the irradiation fluence. The most important finding is that the irradiation-induced free-radical population increases linearly with the displacement damage dose, as does the optical degradation, whereas the ionization effect alone, during the irradiation, cannot induce the formation of pyrolytic carbon free radical. Furthermore, during the post storage, after irradiation, the free-radical population decreases following a sum of an exponential and a linear mode with the storage time. It is interesting that, during the post storage, the recovery of the degraded optical absorbance of the polyimide follows a similar mode to that of free radicals, and the characteristic time constant changes with the wavelength of the optical spectra.

  2. Thermoluminescence and photoluminescence studies on γ-ray-irradiated Ce³⁺,Tb³⁺-doped potassium chloride single crystals.

    PubMed

    Bangaru, S; Saradha, K; Muralidharan, G

    2016-05-01

    Single crystals of KCl doped with Ce(3+),Tb(3+) were grown using the Bridgeman-Stockbarger technique. Thermoluminescence (TL), optical absorption, photoluminescence (PL), photo-stimulated luminescence (PSL), and thermal-stimulated luminescence (TSL) properties were studied after γ-ray irradiation at room temperature. The glow curve of the γ-ray-irradiated crystal exhibits three peaks at 420, 470 and 525 K. F-Light bleaching (560 nm) leads to a drastic change in the TL glow curve. The optical absorption measurements indicate that F- and V-centres are formed in the crystal during γ-ray irradiation. It was attempted to incorporate a broad band of cerium activator into the narrow band of terbium in the KCl host without a reduction in the emission intensity. Cerium co-doped KCl:Tb crystals showed broad band emission due to the d-f transition of cerium and a reduction in the intensity of the emission peak due to (5)D3 -(7)F(j) (j = 3, 4) transition of terbium, when excited at 330 nm. These results support that energy transfer occurs from cerium to terbium in the KCl host. Co-doping Ce(3+) ions greatly intensified the excitation peak at 339 nm for the emission at 400 nm of Tb(3+). The emission due to Tb(3+) ions was confirmed by PSL and TSL spectra.

  3. Influence of Ar-irradiation on structural and nanomechanical properties of pure zirconium measured by means of GIXRD and nanoindentation techniques

    NASA Astrophysics Data System (ADS)

    Kurpaska, L.; Gapinska, M.; Jasinski, J.; Lesniak, M.; Sitarz, M.; Nowakowska-Langier, K.; Jagielski, J.; Wozniak, K.

    2016-12-01

    An effect of Ar-irradiation on structural and nanomechanical properties of pure zirconium at room temperature was investigated. In order to simulate the radiation damage, the argon ions were implanted into the pure zirconium coupons with fluences ranging from 1 × 1015 to 1 × 1017 cm-2. Prior to irradiation, zirconium samples were chemically polished with a solution of HF/HNO3/H2O. Structural properties of the implanted layer were studied using Grazing Incidence X-Ray Diffraction (GIXRD) technique. The nanomechanical properties of the material were measured by means of nanoindentation technique. The obtained results revealed correlation between Ar-implantation fluence, hardness and structural properties (as confirmed by the modification of the diffraction peaks). Material hardening and peak shift & broadening in GIXD spectra were associated with the local increase of micro-strains, which is related to the increased density of type - dislocation loops. Presented study confirms that the structural changes induced by ion irradiation are directly linked to the mechanical response of the sample.

  4. Thermoluminescence of irradiated foodstuffs

    NASA Astrophysics Data System (ADS)

    Oduko, J. M.; Spyrou, N. M.

    Measurements have been made of the thermoluminescent response of a number of foodstuffs, namely spices, chicken bone, eggshell and strawberries. From the results, irradiated samples can be clearly distinguished from unirradiated ones for several weeks after irradiation of 5-10 kGy, or in the case of some spices for up to 20 months. It is concluded that measurement of thermoluminescence is a promising technique for detecting the irradiation of foodstuffs.

  5. Ozone decontamination of bioclean rooms.

    PubMed Central

    Masaoka, T; Kubota, Y; Namiuchi, S; Takubo, T; Ueda, T; Shibata, H; Nakamura, H; Yoshitake, J; Yamayoshi, T; Doi, H; Kamiki, T

    1982-01-01

    To establish a convenient method for decontaminating bioclean rooms, the effect of ozone at 80 mg/m3 for 72 h was compared with formaldehyde vaporization at an initial concentration of 150 mg/m3 with a gradual decrease to 20 mg/m3 during 72 h. Ozone was found to be inferior to formaldehyde in activity. When the bioclean room was decontaminated twice with ozone, the mean colony count per 10 cm2 was decreased to about the same level as when formaldehyde was used. Ozone had a strong caustic effect upon rubber materials. Despite these disadvantages, ozone decontamination was demonstrated to be superior to formaldehyde vaporization because of convenience, insignificant inhalation of the disinfectant by the hospital staff, and very rapid expulsion of the gas after ventilation. Because the disadvantages of ozone can be easily controlled, this study suggests that ozone decontamination is a promising method for maintaining bioclean rooms. PMID:6803668

  6. Spectra of Particulate Backscattering in Natural Waters

    NASA Technical Reports Server (NTRS)

    Gordon, Howard, R.; Lewis, Marlon R.; McLean, Scott D.; Twardowski, Michael S.; Freeman, Scott A.; Voss, Kenneth J.; Boynton, Chris G.

    2009-01-01

    Hyperspectral profiles of downwelling irradiance and upwelling radiance in natural waters (oligotrophic and mesotrophic) are combined with inverse radiative transfer to obtain high resolution spectra of the absorption coefficient (a) and the backscattering coefficient (bb) of the water and its constituents. The absorption coefficient at the mesotrophic station clearly shows spectral absorption features attributable to several phytoplankton pigments (Chlorophyll a, b, c, and Carotenoids). The backscattering shows only weak spectral features and can be well represented by a power-law variation with wavelength (lambda): b(sub b) approx. Lambda(sup -n), where n is a constant between 0.4 and 1.0. However, the weak spectral features in b(sub b), suggest that it is depressed in spectral regions of strong particle absorption. The applicability of the present inverse radiative transfer algorithm, which omits the influence of Raman scattering, is limited to lambda < 490 nm in oligotrophic waters and lambda < 575 nm in mesotrophic waters.

  7. Spectra as windows into exoplanet atmospheres.

    PubMed

    Burrows, Adam S

    2014-09-02

    Understanding a planet's atmosphere is a necessary condition for understanding not only the planet itself, but also its formation, structure, evolution, and habitability. This requirement puts a premium on obtaining spectra and developing credible interpretative tools with which to retrieve vital planetary information. However, for exoplanets, these twin goals are far from being realized. In this paper, I provide a personal perspective on exoplanet theory and remote sensing via photometry and low-resolution spectroscopy. Although not a review in any sense, this paper highlights the limitations in our knowledge of compositions, thermal profiles, and the effects of stellar irradiation, focusing on, but not restricted to, transiting giant planets. I suggest that the true function of the recent past of exoplanet atmospheric research has been not to constrain planet properties for all time, but to train a new generation of scientists who, by rapid trial and error, are fast establishing a solid future foundation for a robust science of exoplanets.

  8. Spectra of Particulate Backscattering in Natural Waters

    NASA Technical Reports Server (NTRS)

    Gordon, Howard, R.; Lewis, Marlon R.; McLean, Scott D.; Twardowski, Michael S.; Freeman, Scott A.; Voss, Kenneth J.; Boynton, Chris G.

    2009-01-01

    Hyperspectral profiles of downwelling irradiance and upwelling radiance in natural waters (oligotrophic and mesotrophic) are combined with inverse radiative transfer to obtain high resolution spectra of the absorption coefficient (a) and the backscattering coefficient (bb) of the water and its constituents. The absorption coefficient at the mesotrophic station clearly shows spectral absorption features attributable to several phytoplankton pigments (Chlorophyll a, b, c, and Carotenoids). The backscattering shows only weak spectral features and can be well represented by a power-law variation with wavelength (lambda): b(sub b) approx. Lambda(sup -n), where n is a constant between 0.4 and 1.0. However, the weak spectral features in b(sub b), suggest that it is depressed in spectral regions of strong particle absorption. The applicability of the present inverse radiative transfer algorithm, which omits the influence of Raman scattering, is limited to lambda < 490 nm in oligotrophic waters and lambda < 575 nm in mesotrophic waters.

  9. Complex soundproofing of industrial rooms

    NASA Technical Reports Server (NTRS)

    Pocsa, V.; Veres, A.; Biborosch, L.

    1974-01-01

    Some structures treated for sound absorption are described that are used to soundproof industrial rooms with a very high noise level. Soundproofing treatments for the walls and coilings or only for the ceilings are considered. In the case of relatively small rooms having a noise source with a high level, complex treatments involve, in addition to soundproofing of the walls and ceiling, suspended panels specially oriented with respect to the noise source. The efficiency of the adopted solutions is compared with calculated damping values.

  10. Complex soundproofing of industrial rooms

    NASA Technical Reports Server (NTRS)

    Pocsa, V.; Veres, A.; Biborosch, L.

    1974-01-01

    Some structures treated for sound absorption are described that are used to soundproof industrial rooms with a very high noise level. Soundproofing treatments for the walls and coilings or only for the ceilings are considered. In the case of relatively small rooms having a noise source with a high level, complex treatments involve, in addition to soundproofing of the walls and ceiling, suspended panels specially oriented with respect to the noise source. The efficiency of the adopted solutions is compared with calculated damping values.

  11. Room temperature terahertz polariton emitter

    SciTech Connect

    Geiser, Markus; Scalari, Giacomo; Castellano, Fabrizio; Beck, Mattias; Faist, Jerome

    2012-10-01

    Terahertz (THz) range electroluminescence from intersubband polariton states is observed in the ultra strong coupling regime, where the interaction energy between the collective excitation of a dense electron gas and a photonic mode is a significant portion of the uncoupled excitation energy. The polariton's increased emission efficiency along with a parabolic electron confinement potential allows operation up to room temperature in a nonresonant pumping scheme. This observation of room temperature electroluminescence of an intersubband device in the THz range is a promising proof of concept for more powerful THz sources.

  12. Continuum Fitting HST QSO Spectra

    NASA Technical Reports Server (NTRS)

    Tytler, David; Oliversen, Ronald J. (Technical Monitor)

    2002-01-01

    The Principal Component Analysis (PCA) method which we are using to fit and describe QSO spectra relies upon the fact that QSO continuum are generally very smooth and simple except for emission and absorption lines. To see this we need high signal-to-noise (S/N) spectra of QSOs at low redshift which have relatively few absorption lines in the Lyman-a forest. We need a large number of such spectra to use as the basis set for the PCA analysis which will find the set of principal component spectra which describe the QSO family as a whole. We have found that too few HST spectra have the required S/N and hence we need to supplement them with ground based spectra of QSOs at higher redshift. We have many such spectra and we have been working to make them suitable for this analysis. We have concentrated on this topic since 12/15/01.

  13. Red phosphorescence from benzo[2,1,3]thiadiazoles at room temperature

    SciTech Connect

    Gutierrez, Gregory D.; Sazama, Graham T.; Wu, Tony; Baldo, Marc A.; Swager, Timothy M.

    2016-05-23

    In this paper, we describe the red phosphorescence exhibited by a class of structurally simple benzo[2,1,3]thiadiazoles at room temperature. The photophysical properties of these molecules in deoxygenated cyclohexane, including their absorption spectra, steady-state photoluminescence and excitation spectra, and phosphorescence lifetimes, are presented. Finally, time-dependent density functional theory calculations were carried out to better understand the electronic excited states of these benzo[2,1,3]thiadiazoles and why they are capable of phosphorescence.

  14. Red phosphorescence from benzo[2,1,3]thiadiazoles at room temperature

    DOE PAGES

    Gutierrez, Gregory D.; Sazama, Graham T.; Wu, Tony; ...

    2016-05-23

    In this paper, we describe the red phosphorescence exhibited by a class of structurally simple benzo[2,1,3]thiadiazoles at room temperature. The photophysical properties of these molecules in deoxygenated cyclohexane, including their absorption spectra, steady-state photoluminescence and excitation spectra, and phosphorescence lifetimes, are presented. Finally, time-dependent density functional theory calculations were carried out to better understand the electronic excited states of these benzo[2,1,3]thiadiazoles and why they are capable of phosphorescence.

  15. Red Phosphorescence from Benzo[2,1,3]thiadiazoles at Room Temperature.

    PubMed

    Gutierrez, Gregory D; Sazama, Graham T; Wu, Tony; Baldo, Marc A; Swager, Timothy M

    2016-06-03

    We describe the red phosphorescence exhibited by a class of structurally simple benzo[2,1,3]thiadiazoles at room temperature. The photophysical properties of these molecules in deoxygenated cyclohexane, including their absorption spectra, steady-state photoluminescence and excitation spectra, and phosphorescence lifetimes, are presented. Time-dependent density functional theory calculations were carried out to better understand the electronic excited states of these benzo[2,1,3]thiadiazoles and why they are capable of phosphorescence.

  16. AGNs with composite spectra.

    NASA Astrophysics Data System (ADS)

    Veron, P.; Goncalves, A. C.; Veron-Cetty, M.-P.

    1997-03-01

    The use of the Baldwin et al. (1981PASP...93....5B) or Veilleux & Osterbrock (1987ApJS...63..295V) diagnostic diagrams allows the unambiguous classification of the nuclear emission line regions of most galaxies into one of three categories: nuclear HII regions or starbursts, Seyfert 2 galaxies and Liners. However, a small fraction of them have a "transition" spectrum. We present spectral observations of 15 "transition" objects at high-dispersion (66Å/mm) around the Hα, [NII]λλ6548,6584 and/or Hβ, [OIII]λλ4959,5007 emission lines. We show that most of these spectra are composite, due to the simultaneous presence on the slit of a Seyfert nucleus and a HII region. Seyfert 2s and Liners seem to occupy relatively small and distinct volumes in the three-dimensional space λ5007/Hβ, λ6584/Hα, λ6300/Hα.

  17. Hygiene and room climate in the operating room.

    PubMed

    Scherrer

    2003-11-01

    The ventilation system is not the most important source to cause surgical site infections via the air. More important is the skin of both staff and patients. The literature did not reveal any reduction of the risk of surgical site infections resulting from the employment of ultra-clean air-systems during surgical procedures, the one exception being high risk operations such as orthopaedic implant surgery. Both ultra-clean air and antimicrobial prophylaxis can reduce the incidence of surgical site infections. If HEPA filters are used, they are only necessary directly in the operating rooms. Other rooms such as the washroom, the anaesthesia preparation room or corridors which are connected to the OR do not have to be treated with HEPA filters. If a laminar air-flow system is installed, there are some factors which have to be considered. The number of operating lamps and the heads of the operating team affect the function of the air ceiling as they form thermic and air-flow resistance and create turbulences. Also, forced air-warming systems, which are used to maintain normal body temperatures for patients during surgery, disturb the ultra-clean field through the air emitted from the blankets used. Moreover, any medical equipment which is cooled by integrated cooling blowers can influence an ultra-clean air system. Existing ventilation systems are not able to create good room conditions for all persons inside the OR. Therefore new ways have to be found to create a room climate taking into account the level of activity.

  18. Large modification in insulator-metal transition of VO{sub 2} films grown on Al{sub 2}O{sub 3} (001) by high energy ion irradiation in biased reactive sputtering

    SciTech Connect

    Azhan, Nurul Hanis; Okimura, Kunio; Ohtsubo, Yoshiyuki; Kimura, Shin-ichi; Zaghrioui, Mustapha; Sakai, Joe

    2016-02-07

    High energy ion irradiation in biased reactive sputtering enabled significant modification of insulator-metal transition (IMT) properties of VO{sub 2} films grown on Al{sub 2}O{sub 3} (001). Even at a high biasing voltage with mean ion energy of around 325 eV induced by the rf substrate biasing power of 40 W, VO{sub 2} film revealed low IMT temperature (T{sub IMT}) at 309 K (36 °C) together with nearly two orders magnitude of resistance change. Raman measurements from −193 °C evidenced that the monoclinic VO{sub 2} lattice begins to transform to rutile-tetragonal lattice near room temperature. Raman spectra showed the in-plane compressive stress in biased VO{sub 2} films, which results in shortening of V–V distance along a-axis of monoclinic structure, a{sub M}-axis (c{sub R}-axis) and thus lowering the T{sub IMT}. In respect to that matter, significant effects in shortening the in-plane axis were observed through transmission electron microscopy observations. V2p{sub 3/2} spectra from XPS measurements suggested that high energy ion irradiation also induced oxygen vacancies and resulted for an early transition onset and rather broader transition properties. Earlier band gap closing against the temperature in VO{sub 2} film with higher biasing power was also probed by ultraviolet photoelectron spectroscopy. Present results with significant modification of IMT behavior of films deposited at high-energy ion irradiation with T{sub IMT} near the room temperature could be a newly and effective approach to both exploring mechanisms of IMT and further applications of this material, due to the fixed deposition conditions and rather thicker VO{sub 2} films.

  19. 39 CFR 3004.12 - Reading room.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Reading room. 3004.12 Section 3004.12 Postal... Reading room. (a) The Commission maintains a public reading room at its offices (901 New York Avenue, NW., Suite 200, Washington, DC 20268-0001) and an electronic reading room at http://www.prc.gov. The...

  20. 39 CFR 3004.12 - Reading room.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 39 Postal Service 1 2012-07-01 2012-07-01 false Reading room. 3004.12 Section 3004.12 Postal... Reading room. (a) The Commission maintains a public reading room at its offices (901 New York Avenue, NW., Suite 200, Washington, DC 20268-0001) and an electronic reading room at http://www.prc.gov. The...

  1. 39 CFR 3004.12 - Reading room.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 39 Postal Service 1 2011-07-01 2011-07-01 false Reading room. 3004.12 Section 3004.12 Postal... Reading room. (a) The Commission maintains a public reading room at its offices (901 New York Avenue, NW., Suite 200, Washington, DC 20268-0001) and an electronic reading room at http://www.prc.gov. The...

  2. 39 CFR 3004.12 - Reading room.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 39 Postal Service 1 2014-07-01 2014-07-01 false Reading room. 3004.12 Section 3004.12 Postal... Reading room. (a) The Commission maintains a public reading room at its offices (901 New York Avenue, NW., Suite 200, Washington, DC 20268-0001) and an electronic reading room at http://www.prc.gov. The...

  3. 32 CFR 296.6 - Reading room.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 2 2012-07-01 2012-07-01 false Reading room. 296.6 Section 296.6 National... Reading room. (a) The NRO shall provide a reading room equipped with hard copy and electronic records as required in the “Electronic Freedom of Information Act Amendments of 1996”. The NRO Reading Room is...

  4. 32 CFR 296.6 - Reading room.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 2 2014-07-01 2014-07-01 false Reading room. 296.6 Section 296.6 National... Reading room. (a) The NRO shall provide a reading room equipped with hard copy and electronic records as required in the “Electronic Freedom of Information Act Amendments of 1996”. The NRO Reading Room is...

  5. 32 CFR 296.6 - Reading room.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 2 2013-07-01 2013-07-01 false Reading room. 296.6 Section 296.6 National... Reading room. (a) The NRO shall provide a reading room equipped with hard copy and electronic records as required in the “Electronic Freedom of Information Act Amendments of 1996”. The NRO Reading Room is...

  6. 39 CFR 3004.12 - Reading room.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 39 Postal Service 1 2013-07-01 2013-07-01 false Reading room. 3004.12 Section 3004.12 Postal... Reading room. (a) The Commission maintains a public reading room at its offices (901 New York Avenue, NW., Suite 200, Washington, DC 20268-0001) and an electronic reading room at http://www.prc.gov. The...

  7. Spectral characteristics of blood irradiated in vivo by therapeutic doses of ultraviolet radiation

    NASA Astrophysics Data System (ADS)

    Zalesskaya, G. A.; Ulashchik, V. S.; Kalosha, I. I.

    2009-10-01

    The influence of therapeutic doses of UV radiation (λ = 254 nm) on spectral characteristics of blood irradiated in vivo has been studied. A comparative analysis of the electronic and IR absorption spectra of blood and its components before and after irradiation, as well as of the gas composition and concentration of blood hemoglobins, revealed that phototransformations of hemoglobins are primary mechanisms of photoreactions in blood UV irradiated in vivo.

  8. Effect of yttrium phosphate on irradiation of methyl vinyl silicone rubber

    NASA Astrophysics Data System (ADS)

    Ma, Depeng; Wu, Lianfeng; Feng, Shengyu; Lu, Haifeng; Zhao, Shigui

    2017-07-01

    Nanoscale Yttrium phosphate (YPO4) particles was prepared by hydrothermal method, and was used as anti-radiation additive for methyl vinyl silicone rubber (MVQ rubber). The mechanical properties and crosslink density of YPO4/MVQ rubber nanocomposites before and after irradiated by γ-rays were determined. The irradiation protection mechanism of YPO4 was discussed using the fluorescence spectra. The results showed that YPO4 could improve the irradiation-resistant properties of silicone rubber.

  9. BPX insulation irradiation program test results

    SciTech Connect

    McManamy, T.J. ); Kanemoto, G. ); Snook, P.G. . Plasma Physics Lab.)

    1991-01-01

    The toroidal field coil insulation for the Burning Plasma Experiment (BPX) is expected to receive a radiation dose of nearly 10{sup 10} rad and to withstand significant mechanical stresses. An irradiation test program was performed at the Idaho National Engineering Laboratory (INEL) using the Advanced Technology Reactor (ATR) for irradiations to doses on the order of 3 {times} 10{sup 10} rad. The flexure and shear strength with compression of commercially procured sheet material were reported earlier. A second series of tests has been performed to slightly higher dose levels with vacuum impregnated materials, glass strand material, and Spaulrad-S sheet samples. Vacuum impregnation with a Shell 9405 resin and 9470 hardener was used to produce bonded copper squares and flexure samples of both pure resin and resin with S-glass. A new test fixture was developed to test the bonded samples in shear without applied compression. The Spaulrad-S flexure samples demonstrated a loss of strength with irradiation, similar to previous results. The pure resin lost nearly all flexibility, while the S-glass-reinforced samples retained between 30% and 40% of the initial flexure strength. The S-glass strands showed a 30% loss of strength at the higher dose level when tested in tension. The bonded copper squares had a low room-temperature shear strength of approximately 17 MPa before irradiation, which was unchanged in the irradiated samples. Shear testing of unirradiated bonded copper squares with ten different types of surface treatment revealed that the low shear strength resulted from the polyurethane primer used. In the later series of test, the epoxy-based primers and DZ-80 from Ciba-Geigy did much better, with shear strengths on the order of 40 MPa. These samples also demonstrated a resistance to cryogenic shock. One irradiated bonded sample was tested up 10 210 MPa in compression, the limit of the test fixture, without failure.

  10. Nanohardness and brittleness of irradiated spinel ceramics

    NASA Astrophysics Data System (ADS)

    Jagielski, J.; Aubert, P.; Maciejak, O.; Piatkowska, A.; Labdi, S.; Jozwik-Biala, I.; Jozwik, P.; Wajler, A.

    2012-09-01

    The influence of the size of crystalline regions on mechanical properties of irradiated oxides has been studied using magnesium aluminate spinel MgAl2O4. The samples characterized by different dimensions of crystalline domains, from sintered ceramics with grains of few micrometers in size up to single crystals, were used in the experiments. The samples were irradiated at room temperature with 320 keV Ar2+ ions up to fluences reaching 5 × 1016 cm-2. Nanomechanical properties were measured by using a nanoindentation technique and the resistance to crack formation by measurement of the total crack lengths made by Vickers indenter. The results revealed: correlation of nanohardness with accumulated damage, radiation-induced hardness increase in grain-boundary region and significant improvement of material resistance to crack formation.

  11. Enantiomeric separation of complex organic molecules from irradiation of interstellar/circumstellar ice analogs

    NASA Astrophysics Data System (ADS)

    Nuevo, M.; Muñoz Caro, G.; Dartois, E.; D'Hendecourt, L.; Deboffle, D.; Meierhenrich, U.; Thiemann, W.; Bredehöft, J. H.; Nahon, L.

    Our laboratory group aims at studying the photo- and thermochemical evolution of dirty ice mixtures (containing H2O, CO, CH4, CH3OH, NH3, etc.) known to be present on the surface of interstellar grains observed in molecular clouds around protostars and also found in comets. The first step was to determine the chemical composition of these ices by comparison of interstellar ice infrared spectra from the European Infrared Space Observatory (ISO) with the spectra obtained in laboratory experiments. That work allowed us to identify and quantify the abundance of simple molecules such as H2O, CO, CO2 and CH4, as well as to understand the shapes of some infrared features (shifts, band widths, splittings) resulting from interactions within the ice structure due to molecular complexes. The irradiation of these ices with UV light at low temperatures down to 10 K leads to the formation of species such as H2CO, NH4+ and OCN-, which have been already identified in astrophysical sources. If the irradiation is continued, more complex molecules, stable at room temperature, are formed. The refractory residue obtained by warming up the sample to room temperature can be analyzed by chemical techniques such as gas chromatography coupled with mass spectrometry (GC-MS). A lot of complex molecules such as glycine, alanine or glycerol are detected, among them amino acids, known to play an important role in prebiotic chemistry. The extension of this experiment, called Chiral MICMOC (for Matière Interstellaire et Cométaire, Molécules Organiques Complexes, i.e. Interstellar and Cometary Matter, Complex Organic Molecules, repeating the same experiment using circularly polarized UV light has been performed with the synchrotron light of the SU5 beam in LURE. The purpose is to reveal and study the possible apparition of an enantiomeric excess on amino acids formed in such experiments. Our preliminary analyses results show that a possible enantiomeric excess would be small. A careful data

  12. Diminished cage effect in solid p-H{sub 2}: Infrared spectra of ClSCS, ClCS, and ClSC in an irradiated p-H{sub 2} matrix containing Cl{sub 2} and CS{sub 2}

    SciTech Connect

    Huang, Chiung-Wei; Lee, Yaw-Chang; Lee, Yuan-Pern

    2010-04-28

    Irradiation of a p-H{sub 2} matrix containing Cl{sub 2} and CS{sub 2} at 3.3 K with laser emission at 340 nm followed by annealing of the matrix produced main features at 1479.5 and 1480.8 cm{sup -1}. These lines are attributed to {nu}{sub 1} (SCS antisymmetric stretching) mode of ClSCS. Irradiation of the matrix at 355 nm decomposes ClSCS. Products CS (1272.2 and 1271.1 cm{sup -1}), ClCS (1193.9/1191.9 and 637.5 cm{sup -1}), and ClSC (1137.0 cm{sup -1}) were observed upon annealing. The assignments were based on comparison of observed vibrational wavenumbers and {sup 13}C- and {sup 34}S-isotopic ratios with those predicted with density-functional theories (B3LYP and BPW91/aug-cc-pVTZ). These results demonstrate that the cage effect of solid p-H{sub 2} is diminished so that isolated Cl was produced via photodissociation of Cl{sub 2} in situ and subsequently reacted with CS{sub 2} to form ClSCS, but not ClC(=S)SCl, upon annealing; typically ClC(=S)SCl was produced as the major product on irradiation of noble-gas matrices containing Cl{sub 2} and CS{sub 2}. Observation of ClSCS but not ClCS{sub 2} is consistent with the theoretical prediction that only formation of the former proceeds via a barrierless path. Similarly, upon irradiation of ClSCS at 355 nm, Cl, CS, and CS{sub 2} were produced; subsequent annealing of the irradiated matrix produced ClSC and ClCS via barrierless paths.

  13. WebSpectra: Online NMR and IR Spectra for Students

    NASA Astrophysics Data System (ADS)

    Merlic, Craig A.; Fam, Barry C.; Miller, Michael M.

    2001-01-01

    WebSpectra is a World Wide Web site at UCLA through which organic chemistry students have convenient access to a library of problems in NMR and IR spectroscopy, ranging in difficulty from introductory to advanced. Students are presented with high-resolution spectra of unknown compounds in addition to the molecular formula. Expandable one-dimensional 1H and 13C NMR spectra are available for all problems and many also include IR, DEPT NMR, and/or COSY NMR spectra. In addition to the spectral problems, WebSpectra provides instructional documents on basic NMR and IR spectroscopy concepts. There is also an IR comparison tool that allows overlays of spectra and a search engine that allows students to locate specific types of compounds based upon name, formula, or functional group. The design and capabilities of this Web-based educational tool are described in this paper.

  14. Locker Room Maintenance Made Easy.

    ERIC Educational Resources Information Center

    Theel, James

    1998-01-01

    Provides examples on ways to make locker room maintenance easier and their use more student-friendly. Improvements include use of indoor-outdoor carpeting with numerous floor drains to cut mildew buildup, adequate ventilation to reduce musty smells, better hot water management, ceramic tiles to reduce water-damage repair and painting needs, and…

  15. Locker Rooms: The Durable Design.

    ERIC Educational Resources Information Center

    Viklund, Roy; Coons, John

    1997-01-01

    Offers advice on heavy-use locker-room design that provides easier maintenance and vandal resistance. Design features and materials used for flooring, ceilings, and walls are addressed as are built-in systems and equipment, toilet and shower fixtures and partitions, lockers, and mechanical and electrical systems. (GR)

  16. Hotels Make Room for Fitness.

    ERIC Educational Resources Information Center

    Koszuta, Laurie Einstein

    1986-01-01

    Hotels, in hopes of gaining a competitive edge, are offering workout rooms, exercise equipment, fitness trails, and jogging tracks, but no standards have been set for safety of the facilities or staff preparedness in exercise screening, equipment use, injury prevention, or first aid. (MT)

  17. Rapid synthesis of single-crystalline TbF{sub 3} with novel nanostructure via ultrasound irradiation

    SciTech Connect

    Zhu, Ling; Liu, Yangjia; Fan, Xizhi; Yang, Daowu; Cao, Xueqiang

    2011-02-15

    Graphical abstract: Terbium fluoride (TbF{sub 3}) nanopeanut has been successfully synthesized via a mild sonochemical route from an aqueous solution of terbium nitrate and fluoroborate without any template or organic additive. Research highlights: {yields} Research highlights {yields} TbF3 nanopeanut was prepared via sonochemical method. {yields} The morphologies of TbF3 can be tuned by ultrasound irradiation and fluoride source. {yields} The TbF3 nanopeanut shows high photoluminescence intensity. -- Abstract: Terbium fluoride (TbF{sub 3}) nanopeanut has been successfully synthesized via a mild sonochemical route from an aqueous solution of terbium nitrate and fluoroborate without any template or organic additive. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and photoluminescence (PL) spectra were utilized to characterize the synthesized samples. The morphologies and optical properties of the obtained TbF{sub 3} nanopeanut can be tuned by ultrasound irradiation as well as the fluoride source. The prepared TbF{sub 3} nanopeanut shows extraordinarily high room temperature photoluminescence intensity comparing to the products prepared by stirring. The possible formation mechanism is proposed in this paper.

  18. Raman measurements in silica glasses irradiated with energetic ions

    SciTech Connect

    Saavedra, R. Martin, P.; Vila, R.; León, M.; Jiménez-Rey, D.; Girard, S.; Boukenter, A.; Ouerdane, Y.

    2014-10-21

    Ion irradiation with energetic He{sup +} (2.5 MeV), O{sup 4+} (13.5 MeV), Si{sup 4+} (24.4 MeV) and Cu{sup 7+} (32.6 MeV) species at several fluences (from 5 × 10{sup 12} to 1.65 × 10{sup 15} ion/cm{sup 2}) were performed in three types of SiO{sub 2} glasses with different OH content (KU1, KS-4V and Infrasil 301). After ion implantation the Raman spectra were measured and compared with the spectra of unirradiated samples. Irradiated samples of the three fused silica grades exhibit changes in the broad and asymmetric R-band (ω{sub 1} around 445 cm{sup −1}), in D{sub 1} (490 cm−1) and D{sub 2} (605 cm{sup −1}) bands associated to small-membered rings. The D{sub 2} band shows an increase with increasing fluences for different ions, indicating structural changes. Raman spectra of ion-irradiated samples were compared with the spectra of neutron irradiated samples at fluences 10{sup 17} n/cm{sup 2} and 1018 n/cm{sup 2}. Macroscopic surface cracking was detected, mainly at fluences corresponding to deposited energies between 10{sup 23} eV/cm{sup 3} and 10{sup 24} eV/cm{sup 3} (after ion beam shutdown)

  19. Highly efficient degradation of dye pollutants by Ce-doped MoO₃ catalyst at room temperature.

    PubMed

    Jin, Yujian; Li, Na; Liu, Haiqiu; Hua, Xia; Zhang, Qiuying; Chen, Mindong; Teng, Fei

    2014-09-14

    In order to efficiently degrade organic pollutants via an easily operated method, Ce-doped MoO3 (Ce(x)/MoO3) samples are synthesized by a simple impregnation method. The samples are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), nitrogen sorption isotherms and UV-vis diffused reflectance spectra (UV-DRS), total organic carbon (TOC), infrared spectroscopy (IR) and mass spectrometry (MS) analyses. Furthermore, we have mainly investigated the degradation of different dye pollutants by the Ce(x)/MoO3 samples, including cationic methylene blue (MB), anionic methyl orange (MO), neutral phenol, and a MB-MO mixture dye. For the single-component MB and MO dyes, the highest degradation efficiencies are achieved by Ce(5)/MoO3 and Ce(10)/MoO3 samples. For the MB-MO mixture dyes, the highest degradation efficiency for MB is achieved by a Ce(10)/MoO3 sample. It is surprising that the degradation efficiency of MB in the MB-MO mixture dye solution is higher than that in the single-component MB dye solution, which has been mainly ascribed to the promoting effect of MO. Moreover, a plausible degradation mechanism of the dyes has been proposed and discussed. It should be noted that the degradation reaction is carried out at room temperature and normal atmospheric pressure, and without light irradiation. As a result, this degradation reaction is obviously different from the conventional thermally activated heterogeneous catalysis (or photocatalysis), in which thermal energy (or light irradiation) is indispensable; also different from a sorption technology, in which the pollutants cannot be degraded, but only transformed from one phase to another one. Thus, the reported degradation reaction is a quite promising environmental cleaning technology, which could be widely practically applied.

  20. Irradiation dose detection of irradiated milk powder using visible and near-infrared spectroscopy and chemometrics.

    PubMed

    Kong, W W; Zhang, C; Liu, F; Gong, A P; He, Y

    2013-08-01

    The objective of this study was to examine the possibility of applying visible and near-infrared spectroscopy to the quantitative detection of irradiation dose of irradiated milk powder. A total of 150 samples were used: 100 for the calibration set and 50 for the validation set. The samples were irradiated at 5 different dose levels in the dose range 0 to 6.0 kGy. Six different pretreatment methods were compared. The prediction results of full spectra given by linear and nonlinear calibration methods suggested that Savitzky-Golay smoothing and first derivative were suitable pretreatment methods in this study. Regression coefficient analysis was applied to select effective wavelengths (EW). Less than 10 EW were selected and they were useful for portable detection instrument or sensor development. Partial least squares, extreme learning machine, and least squares support vector machine were used. The best prediction performance was achieved by the EW-extreme learning machine model with first-derivative spectra, and correlation coefficients=0.97 and root mean square error of prediction=0.844. This study provided a new approach for the fast detection of irradiation dose of milk powder. The results could be helpful for quality detection and safety monitoring of milk powder.