WorldWideScience

Sample records for dosimetry the absorption properties

  1. Particulate absorption properties in the Red Sea from hyperspectral particulate absorption spectra

    KAUST Repository

    Tiwari, Surya Prakash; Zarokanellos, Nikolaos; Kheireddine, Malika; Shanmugam, Palanisamy; Jones, Burton

    2018-01-01

    This paper aims to describe the variability of particulate absorption properties using a unique hyperspectral dataset collected in the Red Sea as part of the TARA Oceans expedition. The absorption contributions by phytoplankton (aph) and non

  2. On the uncertainties of photon mass energy-absorption coefficients and their ratios for radiation dosimetry

    Science.gov (United States)

    Andreo, Pedro; Burns, David T.; Salvat, Francesc

    2012-04-01

    A systematic analysis of the available data has been carried out for mass energy-absorption coefficients and their ratios for air, graphite and water for photon energies between 1 keV and 2 MeV, using representative kilovoltage x-ray spectra for mammography and diagnostic radiology below 100 kV, and for 192Ir and 60Co gamma-ray spectra. The aim of this work was to establish ‘an envelope of uncertainty’ based on the spread of the available data. Type A uncertainties were determined from the results of Monte Carlo (MC) calculations with the PENELOPE and EGSnrc systems, yielding mean values for µen/ρ with a given statistical standard uncertainty. Type B estimates were based on two groupings. The first grouping consisted of MC calculations based on a similar implementation but using different data and/or approximations. The second grouping was formed by various datasets, obtained by different authors or methods using the same or different basic data, and with different implementations (analytical, MC-based, or a combination of the two); these datasets were the compilations of NIST, Hubbell, Johns-Cunningham, Attix and Higgins, plus MC calculations with PENELOPE and EGSnrc. The combined standard uncertainty, uc, for the µen/ρ values for the mammography x-ray spectra is 2.5%, decreasing gradually to 1.6% for kilovoltage x-ray spectra up to 100 kV. For 60Co and 192Ir, uc is approximately 0.1%. The Type B uncertainty analysis for the ratios of µen/ρ values includes four methods of analysis and concludes that for the present data the assumption that the data interval represents 95% confidence limits is a good compromise. For the mammography x-ray spectra, the combined standard uncertainties of (µen/ρ)graphite,air and (µen/ρ)graphite,water are 1.5%, and 0.5% for (µen/ρ)water,air, decreasing gradually down to uc = 0.1% for the three µen/ρ ratios for the gamma-ray spectra. The present estimates are shown to coincide well with those of Hubbell (1977 Rad. Res

  3. Restricted mass energy absorption coefficients for use in dosimetry

    International Nuclear Information System (INIS)

    Brahme, A.

    1977-02-01

    When matter is irradiated by a photon beam the fraction of energy absorbed locally in some region Rsub(Δ) (where the size of the region Rsub(Δ) is related to the range of secondary electrons of some restriction energy Δ) is expressed by the restricted mass energy absorption coefficient. In this paper an example is given of how restricted mass energy absorption coefficients can be calculated from existing differential photon interaction cross sections. Some applications of restricted mass absorption coefficients in dosimetry are also given. (B.D.)

  4. Use of appropriate absorption coefficients in gamma-ray dosimetry

    International Nuclear Information System (INIS)

    Gopinath, D.V.; Natarajan, A.; Subbaiah, K.V.

    1985-01-01

    The current use of the different types of absorption coefficients in the computation of γ-ray energy deposition rates and air dose is critically analyzed. Transport calculations are presented to bring out the errors associated with the use of different absorption coefficients. It is observed that except for source energies in the range of 0.3 to 3.0 MeV the consistent use of the absorption coefficient, μ/sub a/ results in an underestimate of the air dose everywhere and of energy deposition at regions away from source. The underestimate becomes more significant with increased atomic number (Z) of the medium. Based on the computations and analysis it is concluded that the absorption coefficients μ/sub a/ and μ/sub k/ are of very limited use in practical γ-ray dosimetry

  5. Studies of the properties of some saccharides for lyoluminescence dosimetry

    International Nuclear Information System (INIS)

    Hazin, C.A.

    1983-03-01

    Alternative dosimetric methods for high doses are under investigation in a number of research centres. Dosemeters based on the phenomenon of lyoluminescence, i.e., emission of light following dissolution of irradiated organic and inorganic compounds were proposed in the 70's. In the present work, the response of several saccharides submitted to the radiation from a 60 Co source was studied. In order to carry out the study, a measuring system consisting of a light detection chamber and an electrometric unit was designed and built. Thereafter, studies concerning the change in light yield as a function of dose were carried out. Other investigated factors were the change in light yield with solvent pH and temperature and the stability of the response for long term storage. The results showed that maltose, lactose and glucose behaved properly as dosimetric materials for high dose measurements. Besides, no significant changes in the lyoluminescent response ocurred when the solvent pH and temperature varied around the usual values. These results show that the control of these parameters is not critica for the utilization of the saccharides under study for dosimetry. (Author) [pt

  6. Particulate absorption properties in the Red Sea from hyperspectral particulate absorption spectra

    KAUST Repository

    Tiwari, Surya Prakash

    2018-03-16

    This paper aims to describe the variability of particulate absorption properties using a unique hyperspectral dataset collected in the Red Sea as part of the TARA Oceans expedition. The absorption contributions by phytoplankton (aph) and non-algal particles (aNAP) to the total particulate absorption coefficients are determined using a numerical decomposition method (NDM). The NDM is validated by comparing the NDM derived values of aph and aNAP with simulated values of aph and aNAP are found to be in excellent agreement for the selected wavelengths (i.e., 443, 490, 555, and 676nm) with high correlation coefficient (R2), low root mean square error (RMSE), mean relative error (MRE), and with a slope close to unity. Further analyses showed that the total particulate absorption coefficients (i.e., ap(443)average = 0.01995m−1) were dominated by phytoplankton absorption (i.e., aph(443)average = 0.01743m−1) with a smaller contribution by non-algal particles absorption (i.e., aNAP(443)average = 0.002524m−1). The chlorophyll a is computed using the absorption based Line Height Method (LHM). The derived chlorophyll-specific absorption ((a⁎ph = aph(λ)/ChlLH)) showed more variability in the blue part of spectrum as compared to the red part of spectrum representative of the package effect and changes in pigment composition. A new parametrization proposed also enabled the reconstruction of a⁎ph(λ) for the Red Sea. Comparison of derived spectral constants with the spectral constants of existing models showed that our study A(λ) values are consistent with the existing values, despite there is a divergence with the B(λ) values. This study provides valuable information derived from the particulate absorption properties and its spectral variability and this would help us to determine the relationship between the phytoplankton absorption coefficients and chlorophyll a and its host of variables for the Red Sea.

  7. A model for absorption determination of radioactive materials: application in the radio dosimetry and nutrition study

    International Nuclear Information System (INIS)

    Mesquita, C.H. de.

    1991-01-01

    A three-parameter model of the sigmoidal relationship is proposed to explain the food passage by intestinal tube. These parameters are: U = intestinal non-absorbed radioactivity; d parameter related to intestinal food dispersion; and t 50 = time to maximal appearance of material from the intestinal lumen. In order to illustrate the applications of this model and its validity, the absorption of 65 Zn from casein semi-purified diet was evaluated in rats. There was a good agreement between the predicted values and the experimental data when the sigmoidal component was added to the conventional multicompartimental equations. With this kind of model the time to maximal appearance (hours), the true absorption level, the fecal concentration and the intestinal dispersion of the ingested radioactivity material may be determined. (author)

  8. Dosimetry

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    The purpose of ionizing radiation dosimetry is the measurement of the physical and biological consequences of exposure to radiation. As these consequences are proportional to the local absorption of energy, the dosimetry of ionizing radiation is based on the measurement of this quantity. Owing to the size of the effects of ionizing radiation on materials in all of these area, dosimetry plays an essential role in the prevention and the control of radiation exposure. Its use is of great importance in two areas in particular where the employment of ionizing radiation relates to human health: radiation protection, and medical applications. Dosimetry is different for various reasons: owing to the diversity of the physical characteristics produced by different kinds of radiation according to their nature (X- and γ-photons, electrons, neutrons,...), their energy (from several keV to several MeV), the orders of magnitude of the doses being estimated (a factor of about 10 5 between diagnostic and therapeutic applications); and the temporal and spatial variation of the biological parameters entering into the calculations. On the practical level, dosimetry poses two distinct yet closely related problems: the determination of the absorbed dose received by a subject exposed to radiation from a source external to his body (external dosimetry); and the determination of the absorbed dose received by a subject owing to the presence within his body of some radioactive substance (internal dosimetry)

  9. Microwave dielectric absorption spectroscopy aiming at novel dosimetry using DNAs

    Energy Technology Data Exchange (ETDEWEB)

    Izumi, Yoshinobu; Hirayama, Makoto; Matuo, Youichirou [Research Institute of Nuclear Engineering, University of Fukui, Fukui (Japan); Sunagawa, Takeyoshi [Fukui University of Technology, Fukui (Japan)

    2017-03-15

    We are developing L-band and S-band microwave dielectric absorption systems aiming novel dosimetry using DNAs, such as plasmid DNA and genomic DNA, and microwave technology. Each system is composed of a cavity resonator, analog signal generator, circulator, power meter, and oscilloscope. Since the cavity resonator is sensitive to temperature change, we have made great efforts to prevent the fluctuation of temperature. We have developed software for controlling and measurement. By using this system, we can measure the resonance frequency, f, and ΔQ (Q is a dimensionless parameter that describes how under-damped an oscillator or resonator is, and characterizes a resonator’s bandwidth relative to its center frequency) within about 3 minutes with high accuracy. This system will be expected to be applicable to DNAs evaluations and to novel dosimetric system.

  10. Investigating the variability in brown carbon light-absorption properties

    Science.gov (United States)

    Saleh, R.; Cheng, Z.; Atwi, K.

    2017-12-01

    Combustion of biomass fuels contributes a significant portion of brown carbon (BrC), the light-absorbing fraction of organic aerosols. BrC exhibits highly variable light-absorption properties, with imaginary part of the refractive indices (k) reported in the literature varying over two orders of magnitude. This high variability in k is attributed to the chaotic nature of combustion; however, there is a major gap in the fundamental understanding of this variability. To address this gap, we hypothesize that BrC is comprised of black carbon (BC) precursors whose transformation to BC has not seen fruition. Depending on the combustion conditions, these BC precursors exhibit different maturity levels which dictate their light-absorption properties (k). The more mature are the precursors, the more absorptive (or BC-like) they are. Therefore, k of BrC obtained from a certain measurement depends on the specific combustion conditions associated with the measurement, leading to the aforementioned variability in the literature. To test this hypothesis, we performed controlled combustion experiments in which the combustion conditions (temperature and air/fuel ratio) were varied and k was retrieved from real-time multi-wavelength light-absorption measurements at each condition. We used benzene, the inception of which during combustion is the initial critical step leading to BC formation, as a model fuel. By varying the combustion conditions from relatively inefficient (low temperature and/or air/fuel ratio) to relatively efficient (high temperature and/or air/fuel ratio), we isolated BrC components with progressively increasing k, spanning the wide range reported in the literature. We also performed thermodenuder measurements to constrain the volatility of the BrC, as well as laser desorption ionization mass spectrometry analysis to constrain its molecular mass. We found that as the combustion conditions approached the BC-formation threshold, the increase in k was associated

  11. Thermoluminescence dosimetry materials: properties and uses

    International Nuclear Information System (INIS)

    McKeever, S.W.S.; Moscovitch, M.; Townsend, P.D.

    1995-01-01

    This book selects a range of the most popular thermoluminescence dosemeter (TLD) materials in use today and provides a critical account of their thermoluminescence (TL) and dosimetric properties. The information provided includes in-depth discussions of TL mechanisms, including an account of luminescence properties, and relevant information regarding dosimetric characteristics. The book is intended for those involved in TLD materials research, and for technicians and workers involved in the practical application of these materials in TL dosimetry. The advent of modern spectroscopic methods for measuring TL emission spectra (the so-called ''3-D'' presentation) seemed to the authors to be an invitation to compile such spectra for all the major TLD materials. Further consideration led to an expansion of the initial idea to include a compilation of dosimetric properties. One intention is to provide a synopsis of the TL and dosimetric properties of the most widely used TLD materials currently available and to form a link between the solid state defect properties of these materials and their actual dosimetric properties. A second intention is to provide a solid framework from which future studies of TLD materials could be launched. Too often in the past research into TLD materials has been haphazard, to say the least. By illustrating the links between solid state physics and the radiation dosimetry properties of these materials the book points to the future and to the pressing need for enhanced research on TLD materials. (Author)

  12. Measurements of the Absorptive Properties of the Ionosphere

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Absorption of radio waves occurs when electrons responding to the wave fields collide with and transfer energy to the neutral particles. A study of ionospheric...

  13. Absorption properties of identical atoms

    International Nuclear Information System (INIS)

    Sancho, Pedro

    2013-01-01

    Emission rates and other optical properties of multi-particle systems in collective and entangled states differ from those in product ones. We show the existence of similar effects in the absorption probabilities for (anti)symmetrized states of two identical atoms. The effects strongly depend on the overlapping between the atoms and differ for bosons and fermions. We propose a viable experimental verification of these ideas. -- Highlights: •The absorption rates of a pair of identical atoms in product and (anti)symmetrized states are different. •The modifications of the optical properties are essentially determined by the overlapping between the atoms. •The absorption properties differ, in some cases, for bosons and fermions

  14. The selection of stopping power and mass energy absorption coefficient data for the HPA Code of Practice for dosimetry

    International Nuclear Information System (INIS)

    Williams, P.C.

    1985-01-01

    The author draws attention to a discussion by Cunningham and Schultz (1984) which states that, 'with the exception of the NACP and AAPM protocols, the selection of stopping power and energy absorption coefficient ratios has been based upon only the stated accelerating potential of the accelerator', and points out that the HPA Revised Code of Practice should be added to these exceptions. In calculating the HPA's new Csub(lambda) values, a similar, but not identical, approach was taken in order to determine the stopping power and absorption coefficient ratios at each radiation quality. It was recognised that the approximation of a spectrum to a monoenergetic spectrum of between 0.4 and 0.45 of the maximum energy, as had been done in calculating the values, given in ICRU Report 14, was incorrect. (U.K.)

  15. Dosimetric properties of bio minerals applied to high-dose dosimetry using the TSEE technique

    International Nuclear Information System (INIS)

    Vila, G. B.; Caldas, L. V. E.

    2014-08-01

    The study of the dosimetric properties such as reproducibility, the residual signal, lower detection dose, dose-response curve and fading of the thermally stimulated emission exo electronic (TSEE) signal of Brazilian bio minerals has shown that these materials present a potential use as radiation dosimeters. The reproducibility within ± 10% for oyster shell, mother-of-pearl and coral reef samples showed that the signal dispersion is small when compared with the mean value of the measurements. The study showed that the residual signal can be eliminated with a thermal treatment at 300 grades C/1 h. The lower detection dose of 9.8 Gy determined for the oyster shell samples when exposed to beta radiation and 1.6 Gy for oyster shell and mother-of-pearl samples when exposed to gamma radiation can be considered good, taking into account the high doses of this study. The materials presented linearity at the dose response curves in some ranges, but the lack of linearity in other cases presents no problem since a good mathematical description is possible. The fading study showed that the loss of TSEE signal can be minimized if the samples are protected from interferences such as light, heat and humidity. Taking into account the useful linearity range as the main dosimetric characteristic, the tiger shell and oyster shell samples are the most suitable for high-dose dosimetry using the TSEE technique. (Author)

  16. Dosimetric properties of bio minerals applied to high-dose dosimetry using the TSEE technique

    Energy Technology Data Exchange (ETDEWEB)

    Vila, G. B.; Caldas, L. V. E., E-mail: gbvila@ipen.br [Instituto de Pesquisas Energeticas e Nucleares / CNEN, Av. Lineu Prestes 2242, Cidade Universitaria, 05508-000 Sao Paulo (Brazil)

    2014-08-15

    The study of the dosimetric properties such as reproducibility, the residual signal, lower detection dose, dose-response curve and fading of the thermally stimulated emission exo electronic (TSEE) signal of Brazilian bio minerals has shown that these materials present a potential use as radiation dosimeters. The reproducibility within ± 10% for oyster shell, mother-of-pearl and coral reef samples showed that the signal dispersion is small when compared with the mean value of the measurements. The study showed that the residual signal can be eliminated with a thermal treatment at 300 grades C/1 h. The lower detection dose of 9.8 Gy determined for the oyster shell samples when exposed to beta radiation and 1.6 Gy for oyster shell and mother-of-pearl samples when exposed to gamma radiation can be considered good, taking into account the high doses of this study. The materials presented linearity at the dose response curves in some ranges, but the lack of linearity in other cases presents no problem since a good mathematical description is possible. The fading study showed that the loss of TSEE signal can be minimized if the samples are protected from interferences such as light, heat and humidity. Taking into account the useful linearity range as the main dosimetric characteristic, the tiger shell and oyster shell samples are the most suitable for high-dose dosimetry using the TSEE technique. (Author)

  17. [Spectral absorption properties of the water constituents in the estuary of Zhujiang River].

    Science.gov (United States)

    Wang, Shan-shan; Wang, Yong-bo; Fu, Qing-hua; Yin, Bin; Li, Yun-mei

    2014-12-01

    Spectral absorption properties of the water constituents is the main factor affecting the light field under the surface of the water and the spectrum above the surface of the water. Thus, the study is useful for understanding of the water spectral property and the remote reversing of water quality parameters. Absorption properties of total suspended particles, non-algal particles, phytoplankton and CDOM were analyzed using the 30 samples collected in July 2013 in the estuary of Zhujiang River. The results indicated that: (1) the non-algal particles absorption dominated the absorption of the total suspended particles; (2) the absorption coefficient of the non-algal particles, which mainly came from the terrigenous deposits, decreased exponentially from short to long wavelength. In addition, the average value and spatial variation of the slope S(d) were higher than those in inland case- II waters; (3) the absorption coefficient of phytoplankton in 440 nm showed a better polynomial relationship with chlorophyll a concentration, while the absorption coefficient of phytoplankton in 675 nm linearly related with the chlorophyll a concentration. Moreover, the influence of accessory pigments on phytoplankton absorption coefficient mainly existed in the range of short wavelength, and Chlorophyll a was the main influencing factor for phytoplankton absorption in long wavelength. The specific absorption coefficient of phytoplankton decreased the power exponentially with the increase of the chlorophyll a concentration; (4) CDOM mainly came from the terrigenous sources and its spectral curve had an absorption shoulder between 250-290 nm. Thus, a piecewise S(g) fitting function could effectively express CDOM absorption properties, i.e., M value and S(g) value in period A (240-260 nm) showed a strong positive correlation. The M value was low, and the humic acid had a high proportion in CDOM; (5) the non-algal particles absorption dominated the total absorption in the estuary of

  18. Absorption properties of water-in-oil emulsions in the low THz frequency range

    DEFF Research Database (Denmark)

    Møller, Uffe; Folkenberg, Jacob Riis; Jepsen, Peter Uhd

    We use transmission THz spectroscopy to investigate the absorption properties of water-in-oil emulsions with water content varying in the 0-20% range, relevant for a range of food products. We find that at low frequencies the effective absorption coefficient of the emulsion is suppressed compared...... to bulk water....

  19. Influence of moisture absorption on the flexural properties of ...

    Indian Academy of Sciences (India)

    2017-07-27

    Jul 27, 2017 ... However, this type of composite can be used in various applications that do not ... given that the results of an experimental research work carried out with .... method on the basis of irreversible thermodynamics theory. Moreover ...... table 4, which shows a qualitative behaviour of the composite properties ...

  20. Effect of water absorption on the mechanical properties of poly(3-hydroxybutyrate)/vegetable fiber composites

    Science.gov (United States)

    Marinho, Vithória A. D.; Carvalho, Laura H.; Canedo, Eduardo L.

    2015-05-01

    The present work studies the effect of water absorption on the performance of composites of poly(3-hydroxybutyrate) (PHB) - a fully biodegradable semi-crystalline thermoplastic obtained from renewable resources through low-impact biotechnological process, biocompatible and non-toxic - and vegetable fiber from the fruit (coconut) of babassu palm tree.Water resistance is an important characteristic of structural composites, that may exposed to rain and humid environments. Both water absorption capacity (water solubility in the material) and the rate of water absorption (controlled by the diffusivity of water in the material) are important parameters. However, water absorption per se may not be the most important characteristic, insofar as the performance and applications of the compounds. It is the effect of the water content on the ultimate properties that determine the suitability of the material for applications that involve prolonged exposure to water.PHB/babassu composites with 0-20% load were prepared in an internal mixer. Two different types of babassu fibers having two different article size ranges were compounded with PHB and test specimens molded by compression. The water absorption capacity and the kinetic constant of water absorption were measured in triplicate. Mechanical properties under tension were measured for dry and moist specimens with different amounts of absorbed water.Results indicate that the performance of the composites is comparable to that of the pure matrix. Water absorption capacity increases from 0.7% (pure PHB) to 4% (PHB/20% babassu), but the water diffusivity (4.10□8 cm2/s) was found to be virtually independent of the water absorption level. Water absorption results in moderate drop in elastic modulus (10-30% at saturation, according to fiber content) but has little effect on tensile strength and elongation at break. Fiber type and initial particle size do not have a significant effect on water absorption or mechanical properties.

  1. Absorption and scattering properties of arbitrarily shaped particles in the Rayleigh domain

    International Nuclear Information System (INIS)

    Min, M.; Hovenier, J.W.; Dominik, C.; Koter, A. de; Yurkin, M.A.

    2006-01-01

    We provide a theoretical foundation for the statistical approach for computing the absorption properties of particles in the Rayleigh domain. We present a general method based on the discrete dipole approximation to compute the absorption and scattering properties of particles in the Rayleigh domain. The method allows to separate the geometrical aspects of a particle from its material properties. Doing the computation of the optical properties of a particle once, provides them for any set of refractive indices, wavelengths and orientations. This allows for fast computations of e.g. absorption spectra of arbitrarily shaped particles. Other practical applications of the method are in the interpretation of atmospheric and radar measurements as well as computations of the scattering matrix of small particles as a function of the scattering angle. In the statistical approach, the optical properties of irregularly shaped particles are represented by the average properties of an ensemble of particles with simple shapes. We show that the absorption cross section of an ensemble of arbitrarily shaped particles with arbitrary orientations can always be uniquely represented by the average absorption cross section of an ensemble of spheroidal particles with the same composition and fixed orientation. This proves for the first time that the statistical approach is generally viable in the Rayleigh domain

  2. Dosimetry

    International Nuclear Information System (INIS)

    Rezende, D.A.O. de

    1976-01-01

    The fundamental units of dosimetry are defined, such as exposure rate, absorbed dose and equivalent dose. A table is given of relative biological effectiveness values for the different types of radiation. The relation between the roentgen and rad units is calculated and the concepts of physical half-life, biological half-life and effective half-life are discussed. Referring to internal dosimetry, a mathematical treatment is given to β particle-and γ radiation dosimetry. The absorbed dose is calculated and a practical example is given of the calculation of the exposure and of the dose rate for a gama source [pt

  3. The dosimetry of ionizing radiation

    CERN Document Server

    1990-01-01

    A continuation of the treatise The Dosimetry of Ionizing Radiation, Volume III builds upon the foundations of Volumes I and II and the tradition of the preceeding treatise Radiation Dosimetry. Volume III contains three comprehensive chapters on the applications of radiation dosimetry in particular research and medical settings, a chapter on unique and useful detectors, and two chapters on Monte Carlo techniques and their applications.

  4. Water Absorption Behaviour and Its Effect on the Mechanical Properties of Flax Fibre Reinforced Bioepoxy Composites

    Directory of Open Access Journals (Sweden)

    E. Muñoz

    2015-01-01

    Full Text Available In the context of sustainable development, considerable interest is being shown in the use of natural fibres like as reinforcement in polymer composites and in the development of resins from renewable resources. This paper focuses on eco-friendly and sustainable green composites manufacturing using resin transfer moulding (RTM process. Flax fibre reinforced bioepoxy composites at different weight fractions (40 and 55 wt% were prepared in order to study the effect of water absorption on their mechanical properties. Water absorption test was carried out by immersion specimens in water bath at room temperature for a time duration. The process of water absorption of these composites was found to approach Fickian diffusion behavior. Diffusion coefficients and maximum water uptake values were evaluated; the results showed that both increased with an increase in fibre content. Tensile and flexural properties of water immersed specimens were evaluated and compared to dry composite specimens. The results suggest that swelling of flax fibres due to water absorption can have positive effects on mechanical properties of the composite material. The results of this study showed that RTM process could be used to manufacture natural fibre reinforced composites with good mechanical properties even for potential applications in a humid environment.

  5. Nature and statistical properties of quasar associated absorption systems in the XQ-100 Legacy Survey

    DEFF Research Database (Denmark)

    Perrotta, Serena; D'Odorico, Valentina; Prochaska, J. Xavier

    2016-01-01

    We statistically study the physical properties of a sample of narrow absorption line (NAL) systems looking for empirical evidences to distinguish between intrinsic and intervening NALs without taking into account any a priori definition or velocity cut-off. We analyze the spectra of 100 quasars...

  6. Effect of the carbonyl iron particles on acoustic absorption properties of magnetic polyurethane foam

    Science.gov (United States)

    Geng, Jialu; Wang, Caiping; Zhu, Honglang; Wang, Xiaojie

    2018-03-01

    Elastomeric matrix embedded with magnetic micro-sized particles has magnetically controllable properties, which has been investigated extensively in the last decades. In this study we develop a new magnetically controllable elastomeric material for acoustic applications at lower frequencies. The soft polyurethane foam is used as matrix material due to its extraordinary elastic and acoustic absorption properties. One-step method is used to synthesize polyurethane foam, in which all components including polyether polyols 330N, MDI, deionized water, silicone oil, carbonyl iron particle (CIP) and catalyst are put into one container for curing. Changing any component can induce the change of polyurethane foam's properties, such as physical and acoustic properties. The effect of the content of MDI on acoustic absorption is studied. The CIPs are aligned under extra magnetic field during the foaming process. And the property of polyurethane foam with aligned CIPs is also investigated. Scanning electron microscope (SEM) is used to observe the structure of pore and particle-chain. The two-microphone impedance tube and the transfer function method are used to test acoustic absorption property of the magnetic foams.

  7. Connecting the Interstellar Gas and Dust Properties in Distant Galaxies Using Quasar Absorption Systems

    Science.gov (United States)

    Aller, Monique C.; Dwek, Eliahu; Kulkarni, Varsha P.; York, Donald G.; Welty, Daniel E.; Vladilo, Giovanni; Som, Debopam; Lackey, Kyle; Dwek, Eli; Beiranvand, Nassim; hide

    2016-01-01

    Gas and dust grains are fundamental components of the interstellar medium and significantly impact many of the physical processes driving galaxy evolution, such as star-formation, and the heating, cooling, and ionization of the interstellar material. Quasar absorption systems (QASs), which trace intervening galaxies along the sightlines to luminous quasars, provide a valuable tool to directly study the properties of the interstellar gas and dust in distant, normal galaxies. We have established the presence of silicate dust grains in at least some gas-rich QASs, and find that they exist at higher optical depths than expected for diffuse gas in the Milky Way. Differences in the absorption feature shapes additionally suggest variations in the silicate dust grain properties, such as in the level of grain crystallinity, from system-to-system. We present results from a study of the gas and dust properties of QASs with adequate archival IR data to probe the silicate dust grain properties. We discuss our measurements of the strengths of the 10 and 18 micron silicate dust absorption features in the QASs, and constraints on the grain properties (e.g., composition, shape, crystallinity) based on fitted silicate profile templates. We investigate correlations between silicate dust abundance, reddening, and gas metallicity, which will yield valuable insights into the history of star formation and chemical enrichment in galaxies.

  8. Effect of water absorption by the aggregate on properties of high-strength lightweight concrete

    Energy Technology Data Exchange (ETDEWEB)

    Punkki, J

    1996-12-31

    Recently, high-strength lightweight concrete has become an interesting building material for the offshore oil industry. This doctoral thesis presents an experimental investigation of the effect of water absorption by three different types of lightweight aggregates. One type did not show any water absorption ability at all and so represented no problem to the concrete production. For the two other high-strength aggregates, which were of more conventional types, the water absorption depended not only on the properties of the aggregates, but also on the concrete mixing procedure and the properties of the fresh cement paste. When water absorbing lightweight aggregate was used in a dry condition, the workability of the concrete was significantly reduced by the water absorption of the aggregate. This effect was not present when prewetted aggregate was used. The water absorption by the lightweight aggregate also affected the early compressive strength of concrete. After one day, dry aggregate gave on the average 10 MPa higher compressive strength than did prewetted aggregate. The strength-density ratio was affected by the moisture condition of the aggregate. Dry lightweight aggregate gave 9 MPa higher compressive strength at a density of 2000 kg/m{sup 3} compared to that of prewetted aggregate. The water absorption by the lightweight also affected the microstructure of the hardened concrete. Dry lightweight aggregate gave a slightly better microstructure than normal weight aggregate. The results indicate that the use of prewetted aggregate adversely affected the transition zone between the aggregate and the cement paste. 69 refs., 58 figs., 42 tabs.

  9. Effect of water absorption by the aggregate on properties of high-strength lightweight concrete

    Energy Technology Data Exchange (ETDEWEB)

    Punkki, J.

    1995-12-31

    Recently, high-strength lightweight concrete has become an interesting building material for the offshore oil industry. This doctoral thesis presents an experimental investigation of the effect of water absorption by three different types of lightweight aggregates. One type did not show any water absorption ability at all and so represented no problem to the concrete production. For the two other high-strength aggregates, which were of more conventional types, the water absorption depended not only on the properties of the aggregates, but also on the concrete mixing procedure and the properties of the fresh cement paste. When water absorbing lightweight aggregate was used in a dry condition, the workability of the concrete was significantly reduced by the water absorption of the aggregate. This effect was not present when prewetted aggregate was used. The water absorption by the lightweight aggregate also affected the early compressive strength of concrete. After one day, dry aggregate gave on the average 10 MPa higher compressive strength than did prewetted aggregate. The strength-density ratio was affected by the moisture condition of the aggregate. Dry lightweight aggregate gave 9 MPa higher compressive strength at a density of 2000 kg/m{sup 3} compared to that of prewetted aggregate. The water absorption by the lightweight also affected the microstructure of the hardened concrete. Dry lightweight aggregate gave a slightly better microstructure than normal weight aggregate. The results indicate that the use of prewetted aggregate adversely affected the transition zone between the aggregate and the cement paste. 69 refs., 58 figs., 42 tabs.

  10. A new form of the calibration curve in radiochromic dosimetry. Properties and results

    Energy Technology Data Exchange (ETDEWEB)

    Tamponi, Matteo, E-mail: mtamponi@aslsassari.it; Bona, Rossana; Poggiu, Angela; Marini, Piergiorgio [Medical Physics Unit, ASL Sassari, Via Enrico de Nicola, Sassari 07100 (Italy)

    2016-07-15

    Purpose: This work describes a new form of the calibration curve for radiochromic dosimetry that depends on one fit parameter. Some results are reported to show that the new curve performs as well as those previously used and, more importantly, significantly reduces the dependence on the lot of films, the film orientation on the scanner, and the time after exposure. Methods: The form of the response curve makes use of the net optical densities ratio against the dose and has been studied by means of the Beer–Lambert law and a simple modeling of the film. The new calibration curve has been applied to EBT3 films exposed at 6 and 15 MV energy beams of linear accelerators and read-out in transmission mode by means of a flatbed color scanner. Its performance has been compared to that of two established forms of the calibration curve, which use the optical density and the net optical density against the dose. Four series of measurements with four lots of EBT3 films were used to evaluate the precision, accuracy, and dependence on the time after exposure, orientation on the scanner and lot of films. Results: The new calibration curve is roughly subject to the same dose uncertainty, about 2% (1 standard deviation), and has the same accuracy, about 1.5% (dose values between 50 and 450 cGy), as the other calibration curves when films of the same lot are used. Moreover, the new calibration curve, albeit obtained from only one lot of film, shows a good agreement with experimental data from all other lots of EBT3 films used, with an accuracy of about 2% and a relative dose precision of 2.4% (1 standard deviation). The agreement also holds for changes of the film orientation and of the time after exposure. Conclusions: The dose accuracy of this new form of the calibration curve is always equal to or better than those obtained from the two types of curves previously used. The use of the net optical densities ratio considerably reduces the dependence on the lot of films, the

  11. A new form of the calibration curve in radiochromic dosimetry. Properties and results

    International Nuclear Information System (INIS)

    Tamponi, Matteo; Bona, Rossana; Poggiu, Angela; Marini, Piergiorgio

    2016-01-01

    Purpose: This work describes a new form of the calibration curve for radiochromic dosimetry that depends on one fit parameter. Some results are reported to show that the new curve performs as well as those previously used and, more importantly, significantly reduces the dependence on the lot of films, the film orientation on the scanner, and the time after exposure. Methods: The form of the response curve makes use of the net optical densities ratio against the dose and has been studied by means of the Beer–Lambert law and a simple modeling of the film. The new calibration curve has been applied to EBT3 films exposed at 6 and 15 MV energy beams of linear accelerators and read-out in transmission mode by means of a flatbed color scanner. Its performance has been compared to that of two established forms of the calibration curve, which use the optical density and the net optical density against the dose. Four series of measurements with four lots of EBT3 films were used to evaluate the precision, accuracy, and dependence on the time after exposure, orientation on the scanner and lot of films. Results: The new calibration curve is roughly subject to the same dose uncertainty, about 2% (1 standard deviation), and has the same accuracy, about 1.5% (dose values between 50 and 450 cGy), as the other calibration curves when films of the same lot are used. Moreover, the new calibration curve, albeit obtained from only one lot of film, shows a good agreement with experimental data from all other lots of EBT3 films used, with an accuracy of about 2% and a relative dose precision of 2.4% (1 standard deviation). The agreement also holds for changes of the film orientation and of the time after exposure. Conclusions: The dose accuracy of this new form of the calibration curve is always equal to or better than those obtained from the two types of curves previously used. The use of the net optical densities ratio considerably reduces the dependence on the lot of films, the

  12. Effect of resin system on the mechanical properties and water absorption of kenaf fibre reinforced laminates

    International Nuclear Information System (INIS)

    Rassmann, S.; Paskaramoorthy, R.; Reid, R.G.

    2011-01-01

    The objective of this study is to compare the mechanical and water absorption properties of kenaf (Hibiscus cannabinus L.) fibre reinforced laminates made of three different resin systems. The use of different resin systems is considered so that potentially complex and expensive fibre treatments are avoided. The resin systems used include a polyester, a vinyl ester and an epoxy. Laminates of 15%, 22.5% and 30% fibre volume fraction were manufactured by resin transfer moulding. The laminates were tested for strength and modulus under tensile and flexural loading. Additionally, tests were carried out on laminates to determine the impact energy, impact strength and water absorption. The results revealed that properties were affected in markedly different ways by the resin system and the fibre volume fraction. Polyester laminates showed good modulus and impact properties, epoxy laminates displayed good strength values and vinyl ester laminates exhibited good water absorption characteristics. Scanning electron microscope studies show that epoxy laminates fail by fibre fracture, polyester laminates by fibre pull-out and vinyl ester laminates by a combination of the two. A comparison between kenaf and glass laminates revealed that the specific tensile and flexural moduli of both laminates are comparable at the volume fraction of 15%. However, glass laminates have much better specific properties than the kenaf laminates at high fibre volume fractions for all three resins used.

  13. Water absorption and its effect on the tensile properties of tapioca starch/polyvinyl alcohol bioplastics

    Science.gov (United States)

    Judawisastra, H.; Sitohang, R. D. R.; Marta, L.; Mardiyati

    2017-07-01

    Tapioca is one of the largest sources of starch and makes it suitable to be used for bioplastic material. Addition of polyvinyl alcohol (PVA) has been shown to successfully reduce the brittleness of starch bioplastic. This study aims to investigate the influence of PVA addition to water absorption behavior and its effect on the tensile properties of tapioca starch/PVA bioplastics, which are still not yet fully understood until now. The bioplastics were prepared by solution casting method at gelatinization temperature, with PVA addition from 0 to 29 wt%. Examinations were carried out by means of water absorption test, tensile test and Fourier Transform Infrared (FTIR) Spectroscopy. Increasing content of PVA, up to 29 wt%, was found to decrease the water absorption of the bioplastics, with the lowest water saturation point of 251%. This is due to the interaction between starch and PVA which reduces the free OH groups in the resulting bioplastics. Consequently, this led to a decrease in water absorption-related deterioration, i.e. tensile properties degradation of the bioplastics. The addition of 29 wt% resulted into the lowest degradation in tensile strength (6%) and stiffness (30%), while accompanied with the highest elongation increase (39%) after water immersion.

  14. The effect of moisture absorption on the physical properties of polyurethane shape memory polymer foams

    International Nuclear Information System (INIS)

    Yu, Ya-Jen; Hearon, Keith; Maitland, Duncan J; Wilson, Thomas S

    2011-01-01

    The effect of moisture absorption on the glass transition temperature (T g ) and the stress/strain behavior of network polyurethane shape memory polymer (SMP) foams has been investigated. With our ultimate goal of engineering polyurethane SMP foams for use in blood-contacting environments, we have investigated the effects of moisture exposure on the physical properties of polyurethane foams. To the best of our knowledge, this study is the first to investigate the effects of moisture absorption at varying humidity levels (non-immersion and immersion) on the physical properties of polyurethane SMP foams. The SMP foams were exposed to differing humidity levels for varying lengths of time, and they exhibited a maximum water uptake of 8.0% (by mass) after exposure to 100% relative humidity for 96 h. Differential scanning calorimetry results demonstrated that water absorption significantly decreased the T g of the foam, with a maximum water uptake shifting the T g from 67 to 5 °C. Samples that were immersed in water for 96 h and immediately subjected to tensile testing exhibited 100% increases in failure strains and 500% decreases in failure stresses; however, in all cases of time and humidity exposure, the plasticization effect was reversible upon placing moisture-saturated samples in 40% humidity environments for 24 h

  15. Information from the Dosimetry Service

    CERN Multimedia

    2006-01-01

    Please note the following opening hours of the Service: From 31st July onwards: Every morning from 8:30 to 12:00 The Service is closed in the afternoons. We should like to remind you that dosimeters cannot be sent to customers by internal mail. Short-term dosimeters (VCTs) must always be returned to the Service after use and must not be left on the racks in the experimental areas or in the secretariats. Dosimetry Service Tel 72155 Bldg. 24 E 011 Dosimetry.service@cern.ch http://cern.ch/rp-dosimetry

  16. The Vinca dosimetry experiment

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1962-03-15

    On 15 October 1958 there occurred a very brief uncontrolled run of the zero-power reactor at the Boris Kidric Institute of Nuclear Science, Vinca, near Belgrade, Yugoslavia. During this run six persons received various doses of radiation. They were subsequently given medical treatment of a novel kind at the Curie Hospital, Paris. In atomic energy operations to date, very few accidents involving excessive radiation exposure to human beings have occurred. In fact, the cases of acute radiation injury are limited to about 30 known high exposures, few of which were in the lethal or near-lethal range. Since direct experiment to determine the effects of ionizing radiation on man is unacceptable, information on these effects has to be based on a consideration of data relating to accidental exposures, viewed in the light of the much more extensive data obtained from experiments on animals. Therefore, any direct information on the effects of radiation on humans is very valuable. The international dosimetry project described in this report was carried out at Vinca, Yugoslavia, under the auspices of the International Atomic Energy Agency to determine the precise amount of radiation to which the persons had been exposed during the accident. These dosimetry data, together with the record of the carefully observed clinical effects, are of importance both for the scientific study of radiation effects on man and for the development of methods of therapy. The experiment and measurements were carried out at the end of April 1960. The project formed part of the Agency's research programme in the field of health and safety. The results of the experiment are made available through this report to all Member States.

  17. The Vinca dosimetry experiment

    International Nuclear Information System (INIS)

    1962-03-01

    On 15 October 1958 there occurred a very brief uncontrolled run of the zero-power reactor at the Boris Kidric Institute of Nuclear Science, Vinca, near Belgrade, Yugoslavia. During this run six persons received various doses of radiation. They were subsequently given medical treatment of a novel kind at the Curie Hospital, Paris. In atomic energy operations to date, very few accidents involving excessive radiation exposure to human beings have occurred. In fact, the cases of acute radiation injury are limited to about 30 known high exposures, few of which were in the lethal or near-lethal range. Since direct experiment to determine the effects of ionizing radiation on man is unacceptable, information on these effects has to be based on a consideration of data relating to accidental exposures, viewed in the light of the much more extensive data obtained from experiments on animals. Therefore, any direct information on the effects of radiation on humans is very valuable. The international dosimetry project described in this report was carried out at Vinca, Yugoslavia, under the auspices of the International Atomic Energy Agency to determine the precise amount of radiation to which the persons had been exposed during the accident. These dosimetry data, together with the record of the carefully observed clinical effects, are of importance both for the scientific study of radiation effects on man and for the development of methods of therapy. The experiment and measurements were carried out at the end of April 1960. The project formed part of the Agency's research programme in the field of health and safety. The results of the experiment are made available through this report to all Member States

  18. OSL properties of three commonly available salt brands in India for its use in accident dosimetry

    Science.gov (United States)

    Singh, A. K.; Menon, S. N.; Kadam, S. Y.; Koul, D. K.; Datta, D.

    2018-03-01

    Thermally stimulated luminescence (TL) and Optically Stimulated Luminescence (OSL) characterization of three commonly available salt brands in India were undertaken for their application in accident dosimetry. The investigations showed that the luminescence properties differed to some extent with that reported in literature. Dosimetric properties of these salt samples showed that these can be useful in accident dosimetry. Based on the sensitization and fading behaviour of the samples a Single Aliquot Regenerative (SAR) protocol has been proposed for dose estimation.

  19. Results of the dosimetry intercomparison

    International Nuclear Information System (INIS)

    Dure, Elsa S.

    2000-07-01

    The appropriate way to verify the accuracy of the results of dose reported by the laboratories that offer lend personal dosimetry service is in the periodic participation of round of intercomparison dosimetry, undertaken by laboratories whose standards are trace (Secondary Laboratory). The Laboratory of External Personal Dosimetry of the CNEA-PY has participated in three rounds of intercomparison. The first two were organized in the framework of the Model Project RLA/9/030 RADIOLOGICAL WASTE SECURITY, and the irradiations were carried out in the Laboratory of Regional Calibration of the Center of Nuclear Technology Development, Belo Horizonte-Brazil (1998) and in the National Laboratory of Metrology of the ionizing radiations of the Institute of Radioprotection and Dosimetry, Rio de Janeiro-Brazil (1999). The third was organized by the IAEA and the irradiations were made in the Physikalisch-Technische Bundesanstalt PTB, Braunschweig - Federal Republic of Germany (1999-2000) [es

  20. Light absorption properties of brown carbon over the southeastern Tibetan Plateau.

    Science.gov (United States)

    Zhu, Chong-Shu; Cao, Jun-Ji; Huang, Ru-Jin; Shen, Zhen-Xing; Wang, Qi-Yuan; Zhang, Ning-Ning

    2018-06-01

    We present a study of the light-absorbing properties of water-soluble brown carbon (WS-BrC) and methanol-soluble brown carbon (MeS-BrC) at a remote site (Lulang, 3326m above sea level) in the southeastern Tibetan Plateau during the period 2015-2016. The light absorption coefficients at 365nm (b abs365 ) of WS-BrC and MeS-BrC were the highest during winter and the lowest during monsoon season. MeS-BrC absorbs about 1.5 times higher at 365nm compared to WS-BrC. The absorption at 550nm appears lower compared to that of 365nm for WS-BrC and MeS-BrC, respectively. Higher average value of the absorption Ångström exponent (AAE, 365-550nm) was obtained for MeS-BrC (8.2) than that for WS-BrC (6.9). The values of the mass absorption cross section at 365nm (MAC 365 ) indicated that BrC in winter absorbs UV-visible light more efficiently than in monsoon. The results confirm the importance of BrC in contributing to light-absorbing aerosols in this region. The understanding of the light absorption properties of BrC is of great importance, especially in modeling studies for the climate effects and transport of BrC in the Tibetan Plateau. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Using the Properties of Broad Absorption Line Quasars to Illuminate Quasar Structure

    Science.gov (United States)

    Yong, Suk Yee; King, Anthea L.; Webster, Rachel L.; Bate, Nicholas F.; O'Dowd, Matthew J.; Labrie, Kathleen

    2018-06-01

    A key to understanding quasar unification paradigms is the emission properties of broad absorption line quasars (BALQs). The fact that only a small fraction of quasar spectra exhibit deep absorption troughs blueward of the broad permitted emission lines provides a crucial clue to the structure of quasar emitting regions. To learn whether it is possible to discriminate between the BALQ and non-BALQ populations given the observed spectral properties of a quasar, we employ two approaches: one based on statistical methods and the other supervised machine learning classification, applied to quasar samples from the Sloan Digital Sky Survey. The features explored include continuum and emission line properties, in particular the absolute magnitude, redshift, spectral index, line width, asymmetry, strength, and relative velocity offsets of high-ionisation C IV λ1549 and low-ionisation Mg II λ2798 lines. We consider a complete population of quasars, and assume that the statistical distributions of properties represent all angles where the quasar is viewed without obscuration. The distributions of the BALQ and non-BALQ sample properties show few significant differences. None of the observed continuum and emission line features are capable of differentiating between the two samples. Most published narrow disk-wind models are inconsistent with these observations, and an alternative disk-wind model is proposed. The key feature of the proposed model is a disk-wind filling a wide opening angle with multiple radial streams of dense clumps.

  2. Study of the luminescence properties of dental materials for their use in accidental dosimetry

    International Nuclear Information System (INIS)

    Veronese, Ivan; Cantone, Marie C.; Guzzi, Gianpaolo

    2008-01-01

    Full text: The current social and political situation in many world areas and the increasing hostilities between countries and cultures have accentuated the risk of a malicious use of ionising radiations. Terrorist attacks with the intentional disseminations of radioactive materials in urban settlements may involve a large number of persons, and a rapid estimation of the severity of the exposure is required for undertaking suitable protective actions and supporting decision making. Promising methodologies for a prompt dose evaluation, are those exploiting the luminescence and dosimetric properties of objects and materials which can be easily found in the contaminated area. Among these objects, dental materials have the advantage to be on contact with human body and they could therefore represent individual dosimeters in case of accidental exposure to ionising radiation. The interest in the use of dental ceramics for dosimetric purposes dates back to late 1970, however, it is only through the use of high-sensitive experimental techniques and instrumentation today available, that the potentiality of such materials as accidental dosimeters can be exploited. Moreover, innovative materials are being continuously introduced into the market, containing new additives and pigments with peculiar optical properties. In this study, Thermally Stimulated Luminescence (TSL) and Optically Stimulated Luminescence (OSL) techniques are applied to investigate the luminescence and dosimetric properties of several dental materials, including resins, glass and feldspatic ceramics, and also zirconia and alumina based ceramics, being their use widely increased in the recent years in substitution of metal cores. (author)

  3. Alpha alumina exoemissive and thermoluminescent properties. Application to the dosimetry of ionizing radiations in case of accident

    International Nuclear Information System (INIS)

    Alessandri, M.F.

    1989-06-01

    This work consists of two parts. In the first part, a phenomenon of phototransfer in Thermostimulated Exoelectronic Emission (T.S.E.E.) is pointed out. Study of intrinsic T.S.E.E. of alpha alumina exposed to ultraviolet (U.V.) excitation of energy superior to 4 eV shows three T.S.E.E. peaks situated at 240, 325, 535 0 C (heating rate of 2 0 C.s -1 ). The phototransfer phenomenon is then characterized notably by the lowering of the U.V. excitation threshold to 3.5 eV and the increasing of T.S.E.E. response for U.V. energies between 3.5 and 6 eV. Discussion and interpretation of the results obtained are based on the perfect analogy with the phototransfer of Thermoluminescence (T.L.) observed on a similar type of alpha alumina. The second part describes the application of alpha alumina dosimetric properties to accidental irradiation dosimetry and cartography. The material is bound to a textile support to be used for clothes manufacturing for irradiation risking workers. T.S.E.E. and T.L. properties of the selected fabric have been studied. - T.S.E.E. response to a beta irradiation of strontium 90 covers the region [0.01 - 10 Gy], with a dispersion of ± 20%, a non significant thermic fading beyond 72 hours after irradiation and a very important optical fading; - the region in T.L. extends from 0.25 to 10 Gy with X irradiation (45 kV) and from 0.5 to 10 Gy with gamma irradiation of cobalt 60 and caesium 137; the dispersion is ± 20%, the thermic fading is weak and the optical fading is negligible in artificial light or does not vary any more after 5 days of sunlight exposition [fr

  4. Proposal for an experiment at the SIN: contribution on πE3-beam dosimetry. Measurement of particle spectra after pion absorption in biologically interesting nuclei

    International Nuclear Information System (INIS)

    Appel, H.; Boehmer, V.; Bueche, G.; Kluge, W.; Matthay, H.

    It is proposed to measure the energy spectra of light charged particles (protons, deuterons, tritons, 3 He- and 4 He-nuclei) and of neutrons, after the absorption of stopped pions in the biologically interesting hydrogen, oxygen, carbon, and nitrogen nuclei. In addition, the relative particle yield will be examined in tissue-like targets such as polyethylene, plexiglas, and water. Furthermore, it is proposed to measure the coincidence spectra of two particles emitted after absorption, as a function of the angle between their impulses. In the case of a pure three-body decay, these examinations may open the possibility of drawing conclusions about the heavy recoil nuclei arising during pion absorption. Particle energy and type will be determined by a combined time-of-flight/energy measurement with totally absorbent NaI or plastic detectors. The HF signal will serve as a start signal for time-of-flight measurements

  5. Effect of Interfacial Polarization and Water Absorption on the Dielectric Properties of Epoxy-Nanocomposites

    Directory of Open Access Journals (Sweden)

    Philipp Marx

    2017-05-01

    Full Text Available Five types of nanofillers, namely, silica, surface-silylated silica, alumina, surface-silylated alumina, and boron nitride, were tested in this study. Nanocomposites composed of an epoxy/amine resin and one of the five types of nanoparticles were tested as dielectrics with a focus on (i the surface functionalization of the nanoparticles and (ii the water absorption by the materials. The dispersability of the nanoparticles in the resin correlated with the composition (OH content of their surfaces. The interfacial polarization of the thoroughly dried samples was found to increase at lowered frequencies and increased temperatures. The β relaxation, unlike the interfacial polarization, was not significantly increased at elevated temperatures (below the glass-transition temperature. Upon the absorption of water under ambient conditions, the interfacial polarization increased significantly, and the insulating properties decreased or even deteriorated. This effect was most pronounced in the nanocomposite containing silica, and occurred as well in the nanocomposites containing silylated silica or non-functionalized alumina. The alternating current (AC breakdown strength of all specimens was in the range of 30 to 35 kV·mm−1. In direct current (DC breakdown tests, the epoxy resin exhibited the lowest strength of 110 kV·mm−1; the nanocomposite containing surface-silylated alumina had a strength of 170 kV·mm−1. In summary, water absorption had the most relevant impact on the dielectric properties of nanocomposites containing nanoparticles, the surfaces of which interacted with the water molecules. Nanocomposites containing silylated alumina particles or boron nitride showed the best dielectric properties in this study.

  6. Effect of water absorption on the mechanical properties of nanoclay filled recycled cellulose fibre reinforced epoxy hybrid nanocomposites

    KAUST Repository

    Alamri, H.; Low, I.M.

    2013-01-01

    . The addition of nanoclay slightly minimized the effect of moisture on the mechanical properties. SEM images showed that water absorption severely damaged the cellulose fibres and the bonding at fibres-matrix interfaces in wet composites. © 2012 Elsevier Ltd

  7. Information from the Dosimetry Service

    CERN Multimedia

    2006-01-01

    Please note the following opening hours of the Service: In June: Every morning from 8:30 to 12:00 In July: Mondays, Wednesdays and Fridays from 8:30 to 11:30 Closed all day on Tuesdays and Thursdays From 31st July onwards: Every morning from 8:30 to 12:00 The Service is closed in the afternoons. We should like to remind you that dosimeters cannot be sent to customers by internal mail. Short-term dosimeters (VCTs) must always be returned to the Service after use and must not be left on the racks in the experimental areas or in the secretariats. Dosimetry Service Tel 72155 Bldg. 24 E 011 Dosimetry.service@cern.ch http://cern.ch/rp-dosimetry

  8. Investigation of PBAT dosimetric properties for high gamma dose dosimetry

    International Nuclear Information System (INIS)

    Cunha, Elisete L.; Schimitberger, Thiago

    2017-01-01

    Poly(butylene adipate-co-terephthalate) (PBAT) is an aliphatic-aromatic copolyester which is biodegradable. It is a non-photoluminescent copolyester that becomes photoluminescent after previous exposure to gamma doses higher than 100 kGy. After the previous high energy irradiation, the material shows the highest photo-stimulated luminescence emission when excited with a LED source at wavelengths ranging from 370 to 405 nm. In this work we investigated the enhancement of the photoluminescence (PL) and dosimetric properties of PBAT, after exposure to high doses of gamma radiation ranging from 50 to 4,000 kGy. In this investigation we demonstrate that increasing the PBAT film thickness by 100 μm enhances the PL output by 3.5 times, when irradiated with 500 kGy. Also, besides the already known color green brightness, the PL intensity can also be used for high dose dosimetry purposes for doses ranging from 50 to 750 kGy. The FTIR analysis has demonstrated that the there is a linear relationship between peak intensity and dose for doses ranging from 100 and 2,000 kGy for the absorbance peaks at 3,241 cm -1 and 3271 cm -1 , with linear correlation coefficients of 0.9981 and 0.9992, respectively. The results indicate that PBAT has great potential for applications in bio-imaging devices and high gamma dose dosimetry. (author)

  9. Investigation of PBAT dosimetric properties for high gamma dose dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, Elisete L.; Schimitberger, Thiago, E-mail: elisete.cunha@cdtn.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Oliveira, Cristiana M.; Faria, Luiz O., E-mail: farialo@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    Poly(butylene adipate-co-terephthalate) (PBAT) is an aliphatic-aromatic copolyester which is biodegradable. It is a non-photoluminescent copolyester that becomes photoluminescent after previous exposure to gamma doses higher than 100 kGy. After the previous high energy irradiation, the material shows the highest photo-stimulated luminescence emission when excited with a LED source at wavelengths ranging from 370 to 405 nm. In this work we investigated the enhancement of the photoluminescence (PL) and dosimetric properties of PBAT, after exposure to high doses of gamma radiation ranging from 50 to 4,000 kGy. In this investigation we demonstrate that increasing the PBAT film thickness by 100 μm enhances the PL output by 3.5 times, when irradiated with 500 kGy. Also, besides the already known color green brightness, the PL intensity can also be used for high dose dosimetry purposes for doses ranging from 50 to 750 kGy. The FTIR analysis has demonstrated that the there is a linear relationship between peak intensity and dose for doses ranging from 100 and 2,000 kGy for the absorbance peaks at 3,241 cm{sup -1} and 3271 cm{sup -1}, with linear correlation coefficients of 0.9981 and 0.9992, respectively. The results indicate that PBAT has great potential for applications in bio-imaging devices and high gamma dose dosimetry. (author)

  10. Effect of water absorption on the mechanical properties of nanoclay filled recycled cellulose fibre reinforced epoxy hybrid nanocomposites

    KAUST Repository

    Alamri, H.

    2013-01-01

    Recycled cellulose fibre (RCF) reinforced epoxy/clay nanocomposites were successfully synthesized with different weight percentages (0%, 1%, 3% and 5%) of organoclay platelets (30B). The objective of this study was to investigate the effect of water absorption on the physical and mechanical properties of the RCF reinforced epoxy/clay nanocomposites. TEM images indicated a well-intercalated structure of nanoclay/epoxy matrix with some exfoliated regions. Water absorption was found to decrease as the clay content increased. The flexural strength, flexural modulus and fracture toughness significantly decreased as a result of water absorption. However, the properties of impact strength and impact toughness were found to increase after exposing to water. The addition of nanoclay slightly minimized the effect of moisture on the mechanical properties. SEM images showed that water absorption severely damaged the cellulose fibres and the bonding at fibres-matrix interfaces in wet composites. © 2012 Elsevier Ltd. All rights reserved.

  11. Information from the Dosimetry Service

    CERN Multimedia

    2006-01-01

    CERN Staff and Users can now consult their dose records for an individual or an organizational unit with HRT. Please see more information on our web page: http://cern.ch/rp-dosimetry. The Dosimetry Service is open every morning from 8.30 to 12.00 and is closed in the afternoons. We would like to remind you that dosimeters cannot be sent to customers by internal mail. Short-term dosimeters (VCT's) must always be returned to the Service after use and must not be left on the racks in the experimental areas or in the secretariats.

  12. Information from the Dosimetry Service

    CERN Multimedia

    2006-01-01

    CERN Staff and Users can now consult their dose records for an individual or an organizational unit with HRT. Please see more information on our web page http://cern.ch/rp-dosimetry. The Dosimetry Service is open every morning from 8.30 - 12.00, and closed in the afternoons. We would like to remind you that dosimeters cannot be sent to customers by internal mail. Short-term dosimeters (VCT's) must always be returned to the Service after use and must not be left on the racks in the experimental areas or in the secretariats.

  13. Optimization of the preparation method of LiF: Mg, Cu, P and study of its thermoluminescent properties to be used in ionizing radiation dosimetry

    International Nuclear Information System (INIS)

    Gonzalez M, P.R.

    1995-01-01

    In this thesis the preparation and dosimetric properties of the thermoluminescence phosphor LiF doped with magnesium, copper and phosphorus are studied. In chapter 1 luminescence phenomenon in solids is described, emphasizing the importance of thermally stimulated luminescence known as thermoluminescence (TL) as well as its application in ionizing radiation dosimetry. The models used to determine the kinetics parameters in the TL phenomenon are described in chapter 2. In chapter 3, the dosimetric characteristics of a TL materials and its requirements for dosimetry are analyzed. The preparation method of LiF: Mg, Cu, P is presented in chapter 4 studying its general characteristics for dosimetry. The concentrations of dopants, glow curve structure, TL response to gamma, beta and alpha exposures are studied along with those of LiF: Mg, Cu, P prepared for other authors and with those of LiF: Mg, Ti (TLD-100). The kinetic parameters of the phosphor were determined by the deconvolution method. Pellets of this new phosphor powder were made by pressing it at room temperature and sintering in inert atmosphere at 700 Centigrade degrees. Dosimetric characteristics of these pellets were also studied. Chapter 5 presents the results and conclusions of this study. The new dosimeter exhibited three peaks in its glow curve at 140, 180 and 220 Centigrade degrees respectively. Its TL response to gamma radiation was linear from 43.5 μ Gy to 100 Gy. This dosimeter is reusable and stable without significant loss of sensitivity. Its sensitivity was about 30 times higher than that of TLD-100. Fading of this dosimeter was negligible at room temperature as well as at body temperature (37 Centigrade degrees), and 65% at 60 Centigrade degrees. In conclusion, this dosimeter meets all the requirements of the ANSI standard. These and other characteristics render this dosimeter useful in diverse applications of radiation dosimetry. (Author)

  14. Microwave absorption property of the diatomite coated by Fe-CoNiP films

    Science.gov (United States)

    Yan, Zhenqiang; Cai, Jun; Xu, Yonggang; Zhang, Deyuan

    2015-08-01

    A bio-absorbent of Fe-CoNiP coated on the diatomite was fabricated by way of electroless plating of CoNiP and subsequent chemical vapor deposition of Fe. The surface morphology and composition of the above-mentioned diatomite particles at different stage were characterized with the scanning electron microscopy and the energy spectrum analysis respectively, and the results showed that the diatomite was successfully coated with CoNoP and Fe (carbony iron). The complex permittivity and permeability of composites filled with the bio-absorbent and paraffin was measured in frequency range of 2-18 GHz, and then the microwave reflection loss (RL) and the shielding effectiveness (SE) were calculated. The results showed that the permittivity and the permeability were both enlarged as Fe films were coated onto the CoNiP-coated diatomite, which was attributed to the excellent electromagnetic property of carbonyl irons. The composites made with the Fe-CoNiP diatomite had a better absorbing property (minimum RL -11.0 dB) as well as the shielding property (maximum SE 5.6 dB) at thickness 2 mm. It indicated the absorption property was mainly due to the attenuation on the microwave, and the Fe-CoNiP diatomite could be an effective absorbent with low-density.

  15. Properties of an extrapolation chamber for beta radiation dosimetry

    International Nuclear Information System (INIS)

    Caldas, L.V.E.

    The properties of a commercial extrapolation chamber were studied, and the possibility is shown of its use in beta radiation dosimetry. The chamber calibration factors were determined for several sources ( 90 Sr, 90 Y- 204 Tl and 147 Pm) making known the dependence of its response on the energy of the incident radiation. Extrapolation curves allow to obtain independence on energy for each source. One of such curves, shown for the 90 Sr- 90 Y source at 50 cm from the detector, is obtained through the variation of the chamber window thickness and the extrapolation to the null distance (determined graphically). Different curves shown also: 1) the dependence of the calibration factor on the average energy of beta radiation; 2) the variation of ionization current with the distance between the chamber and the sources; 3) the effect of the collecting electrode area on the value of calibration factors for the different sources. (I.C.R.) [pt

  16. Measurement of properties of a lithium bromide aqueous solution for the determination of the concentration for a prototype absorption machine

    International Nuclear Information System (INIS)

    Labra, L.; Juárez-Romero, D.; Siqueiros, J.; Coronas, A.; Salavera, D.

    2017-01-01

    Highlights: • Determination of concentration of absorption mixture for absorption heat transformers. • Measurement of physical properties for heat transformer assessment. • Comparative behavior of Electric conductivity, Refractive index, and density of LiBr-H_2O. - Abstract: An electrolyte solution of Lithium Bromide (LiBr) water was chosen for study because of its wide use in prototype absorption machines. The LiBr must be operated close to the temperature and mass fraction at which lithium bromide achieves the highest efficiency. For the purpose of establishing the concentration in a prototype absorption machines, measurements were made of the properties that vary with temperature and concentration. The selected properties are electrical conductivity, density, refractive indexes and sound velocity. The resulting measured properties values were compared with some values found in previous works. The properties of aqueous lithium bromide solutions were measured at the concentration range of 45–65% of LiBr and temperatures range of 20–80 °C. Semi-empirical correlations that determine the properties of lithium bromide are also proposed. The methods for measuring the properties of aqueous solutions were considered taking into account their reliability, simplicity and sampling time.

  17. Dosimetry of the respiratory tract

    International Nuclear Information System (INIS)

    Roy, M.

    1996-01-01

    A new dosimetric model of the human respiratory tract has been recently recommended by the International Commission on Radiological Protection, in ICRP Publication 66. This model was intended to update the previous lung model of the Task Group on Lung Dynamics that was adopted by ICRP in Publication 30. With this aim, extensive reviews of the available knowledge were made for anatomy and physiology of the respiratory tract and for deposition, clearance and biological effects of inhaled radionuclides. Finally, expanded dosimetry requirements resulted in a widely different approach from the former model. The main features of the new model are the followings: instead of calculating the average dose to the total mass of blood filled lung, the model takes account of differences in radiosensitivity of the venous respiratory tract tissues. It applies not only to adult workers but also to all members of the population, and provides reference values for children aged 3 months, 1, 5, 10, and 15 years, and adults. Deposition modelling of airborne gases and aerosols associates age dependent breathing rates, airway dimensions and physical activity, to particle size, density and chemical form of inhaled material. Clearance results of competition between mechanical transport clearance and absorption to blood. At each step of the calculation, adjustment guidance is provided to account for use of exact values of particle sizes and specific dissolution rates of inhaled material in order to calculate their own parameter of retention in the airways, and to assess accurately doses to the respiratory tract. Possible influence of smoking, of respiratory tract diseases and of eventual exposure to airborne toxicants is also addressed. (author)

  18. Seasonal variability in CDOM absorption and fluorescence properties in the Barataria Basin, Louisiana, USA.

    Science.gov (United States)

    Singh, Shatrughan; D'Sa, Eurico; Swenson, Erick

    2010-01-01

    Absorption and fluorescence properties of chromophoric dissolved organic matter (CDOM) along a 124 km transect in the Barataria Basin, a large estuary located in Louisiana, USA, were investigated during high and low flow periods of the Mississippi River in the spring and winter of 2008-2009. Mean CDOM absorption at 355 nm from the marine to the freshwater end member stations ranged from (3.25 +/- 0.56) to (20.76 +/- 2.43) m(-1) for the three month high flow period whereas it varied from (1.48 +/- 1.08) to (25.45 +/- 7.03) m(-1) for the same stations during low flow period. Corresponding salinity values at these stations indicated the influence of river and shelf exchanges in the lower basin and precipitation and runoff in the upper basin. An inverse relationship of CDOM absorbance and fluorescence with salinity observed in the basin could be a useful indicator of salinity. CDOM fluorescence also varied over a large range showing an approximately 8 to 12-fold increase between the marine and freshwater end members for the two flow seasons. Excitation-emission matrix spectral plots indicated the presence of various fluorescence components with highest being the A-peak, lowest the T-peak, and the C and M-peaks showing similar trends along the transect. During low flow season the A/C ratio were well correlated with station locations indicating increased terrestrial influence towards the upper basin. CDOM absorption and fluorescence at 355 nm were highly correlated and independent of CDOM sources suggesting that fluorescence could be used to characterize CDOM in the basin.

  19. The personal dosimetry in Mexico

    International Nuclear Information System (INIS)

    Salazar, M.A.

    2006-01-01

    The Personal Dosimetry in Mexico, has an approximately 30 year-old history; and it had been and it is at the moment, one of the more important resources with which the personnel that works with ionizing radiation sources counts for its protection. The Personal Dosimetry begins with the film dosimetry, technique that even continues being used at the present time by some users, and the main reason of its use is for economic reasons. At the moment this technique, it has been surpassed, by the Thermoluminescent dosimetry, which has taken a lot of peak, mainly by the technological development with which it is counted at the present time; what has given as a result that this technique becomes tip technology; that supported in the characteristic of the used materials, as the handling and processing of the information associated with the new PC, digitizer cards, software etc, what has allowed increases it potential. In this work the current necessities of the market are presented as well as an analysis of the future real necessities in Mexico, at national level, the companies that provide this service and that they spread to satisfy this necessity of the market, including the different used technologies are also mentioned. The application ranges, at the same time, of the advantages and disadvantages of the different systems of Personal Dosimetry in the market. The companies that at the moment provide the service of Personal Dosimetry, its use materials and equipment in indistinct form, for the monitoring of gamma radiation, beta particles, different qualities of x-ray radiation, and sometimes neutrons. The monitoring of the exposed personnel at the diverse sources of ionizing radiation mentioned is carried out in many occasions without having with the materials (detectors), neither the appropriate infrastructure and therefore without the quality control that guarantees a correct evaluation of the dose equivalent, as a result of the exposure to the ionizing radiations; it

  20. Gamma Dosimetry Based on the Polymerization Of Methacrylonitrile and Subsequent Determination of the Ketenimine Absorption at 4.96 {mu}m

    Energy Technology Data Exchange (ETDEWEB)

    Talat-Erben, M.; Uenseren, Envare; Seber, Nurten [Cekmece Nuclear Research And Training Centre, P.K.l. Hava Alani, Istanbul (Turkey)

    1967-03-15

    The gamma-ray - initiated polymerization of methacrylonitrile produces ketenimine linkages ( >C = C = N-) , which have a characteristic absorption band at 4.95 {mu}m. The optical density at this wave-length of the irradiated monomer increases almost linearly with the gamma dose up to 30% conversion. The ketenimine group is surprisingly stable under gamma irradiation, and post-effects are absent. Exposure to radiation and subsequent measurement of the optical density (or transmittance) at this specific wave-length makes it possible to determine doses of up to about 20 Mrad, without dilution of the sample. Still higher doses can be determined if the sample is diluted with unirradiated monomer before spectrophotometry. Methacrylonitrile seems superior to other polymerization dosimeters on the grounds that separation and quantitative determination of the polymer formed are unnecessary, and that errors and difficulties usually associated with such operations do not arise. The same system can be used for determining several doses cumulatively. (author)

  1. Impact of absorptivity and wavelength on the optical properties of aggregates with sintering necks

    Science.gov (United States)

    Bao, Yujia; Huang, Yong; He, Beichen

    2018-04-01

    In this paper, we constructed sintered aggregates based on the particle superposition model and apply the ball-necking factor η to characterize the sintering degree. The impact of the absorptivity characterized by the complex refractive index m and the wavelength of the incident light λ on the optical properties of aggregates with different η were compared and investigated. The results indicate that for different m and λ, the light scattering characteristics exhibit regular changes in the values, the peak locations and the size trends. Further, the deviation of 1 - S22/S11 caused by various η is noteworthy and considerable so that it can be used as a probe sensor parameter in the detection of the sintered aggregates configuration.

  2. Investigation of absorption spectra of Gafchromic EBT2 film's components and their impact on UVR dosimetry

    Science.gov (United States)

    Aydarous, Abdulkadir

    2016-05-01

    The absorption spectra of the EBT2 film's components were investigated in conjunction with its use for UVA dosimetry. The polyester (topside) and adhesive layers of the EBT2 film have been gently removed. Gafchromic™ EBT2 films with and without the protected layers (polyester and adhesive) were exposed to UVR of 365 nm for different durations. Thereafter, the UV-visible spectra were measured using a UV-visible spectrophotometer (Model Spectro Dual Split Beam, UVS-2700). Films were digitized using a Nikon CanoScan 9000F Mark II flatbed scanner. The dosimetric characteristics including film's uniformity, reproducibility and post-irradiation development were investigated. The color development of EBT2 and new modified EBT2 (EBT2-M) films irradiated with UVA was relatively stable (less than 1%) immediately after exposure. Based on this study, the sensitivity of EBT2 to UVR with wavelength between ~350 nm and ~390 nm can significantly be enhanced if the adhesive layer (~25 μm) is removed. The polyester layer plays almost no part on absorbing UVR with wavelength between ~320 nm and ~390 nm. Furthermore, various sensitivities for the EBT2-M film has been established depending on the wavelength of analysis.

  3. Microwave absorption property of the diatomite coated by Fe-CoNiP films

    International Nuclear Information System (INIS)

    Yan, Zhenqiang; Cai, Jun; Xu, Yonggang; Zhang, Deyuan

    2015-01-01

    Highlights: • The bio-absorbent coated Fe-CoNiP was fabricated by electroless and CVD. • The EM parameters were enlarged as Fe coated on the diatomite. • The coating CIPs play a key role in the enhancement mechanism. • The Fe-CoNiP diatomite had a better absorbing and shielding properties. - Abstract: A bio-absorbent of Fe-CoNiP coated on the diatomite was fabricated by way of electroless plating of CoNiP and subsequent chemical vapor deposition of Fe. The surface morphology and composition of the above-mentioned diatomite particles at different stage were characterized with the scanning electron microscopy and the energy spectrum analysis respectively, and the results showed that the diatomite was successfully coated with CoNoP and Fe (carbony iron). The complex permittivity and permeability of composites filled with the bio-absorbent and paraffin was measured in frequency range of 2–18 GHz, and then the microwave reflection loss (RL) and the shielding effectiveness (SE) were calculated. The results showed that the permittivity and the permeability were both enlarged as Fe films were coated onto the CoNiP-coated diatomite, which was attributed to the excellent electromagnetic property of carbonyl irons. The composites made with the Fe-CoNiP diatomite had a better absorbing property (minimum RL −11.0 dB) as well as the shielding property (maximum SE 5.6 dB) at thickness 2 mm. It indicated the absorption property was mainly due to the attenuation on the microwave, and the Fe-CoNiP diatomite could be an effective absorbent with low-density

  4. Microwave absorption property of the diatomite coated by Fe-CoNiP films

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Zhenqiang; Cai, Jun; Xu, Yonggang, E-mail: xuyonggang221@163.com; Zhang, Deyuan

    2015-08-15

    Highlights: • The bio-absorbent coated Fe-CoNiP was fabricated by electroless and CVD. • The EM parameters were enlarged as Fe coated on the diatomite. • The coating CIPs play a key role in the enhancement mechanism. • The Fe-CoNiP diatomite had a better absorbing and shielding properties. - Abstract: A bio-absorbent of Fe-CoNiP coated on the diatomite was fabricated by way of electroless plating of CoNiP and subsequent chemical vapor deposition of Fe. The surface morphology and composition of the above-mentioned diatomite particles at different stage were characterized with the scanning electron microscopy and the energy spectrum analysis respectively, and the results showed that the diatomite was successfully coated with CoNoP and Fe (carbony iron). The complex permittivity and permeability of composites filled with the bio-absorbent and paraffin was measured in frequency range of 2–18 GHz, and then the microwave reflection loss (RL) and the shielding effectiveness (SE) were calculated. The results showed that the permittivity and the permeability were both enlarged as Fe films were coated onto the CoNiP-coated diatomite, which was attributed to the excellent electromagnetic property of carbonyl irons. The composites made with the Fe-CoNiP diatomite had a better absorbing property (minimum RL −11.0 dB) as well as the shielding property (maximum SE 5.6 dB) at thickness 2 mm. It indicated the absorption property was mainly due to the attenuation on the microwave, and the Fe-CoNiP diatomite could be an effective absorbent with low-density.

  5. Luminescence properties of KCl:Ag{sup -} crystals excited near the fundamental absorption edge

    Energy Technology Data Exchange (ETDEWEB)

    Kawai, Taketoshi, E-mail: buri@p.s.osakafu-u.ac.jp [Department of Physical Science, Graduate School of Science, Osaka Prefecture University, Gakuen-cho 1-1, Naka-ku, Sakai, Osaka 599-8531 (Japan); Hirai, Takeshi [Department of Physical Science, Faculty of Science and Engineering, Ritsumeikan University, Noji Higashi 1-1-1, Kusatsu, Shiga 525-8577 (Japan)

    2012-02-15

    Luminescence properties of KCl single crystals doped with Ag{sup -} centers have been investigated under various excitation energies around the fundamental absorption edge at low temperatures. Under the excitation at 6.89 eV, which is lower than the intrinsic exciton energy by 0.87 eV, the A Prime luminescence band due to the intraionic transition in the Ag{sup -} ion is dominantly observed at 2.91 eV. On the other hand, the excitation at 6.66 eV induces a broad luminescence band at 2.60 eV in addition to the A Prime luminescence band. From the comparison with the localized excitons in KCl:I crystals, the 2.60 eV luminescence band is attributed to the two-center type localized exciton related with the Ag{sup -} ion. The adiabatic potential energy surfaces of the excited states in the Ag{sup -} center and the localized exciton in KCl:Ag{sup -} are discussed. - Highlights: Black-Right-Pointing-Pointer We study the luminescence properties of KCl single crystals doped with Ag{sup -} ions. Black-Right-Pointing-Pointer The excitation around the absorption edge induces a broad luminescence at 2.60 eV. Black-Right-Pointing-Pointer The 2.60 eV luminescence is attributed to the exciton localized at the Ag{sup -} ion. Black-Right-Pointing-Pointer The localized exciton has the two-center type configuration of the relaxed exciton.

  6. ESR Dosimetry

    International Nuclear Information System (INIS)

    Baffa, Oswaldo; Rossi, Bruno; Graeff, Carlos; Kinoshita, Angela; Chen Abrego, Felipe; Santos, Adevailton Bernardo dos

    2004-01-01

    ESR dosimetry is widely used for several applications such as dose assessment in accidents, medical applications and sterilization of food and other materials. In this work the dosimetric properties of natural and synthetic Hydroxyapatite, Alanine, and 2-Methylalanine are presented. Recent results on the use of a K-Band (24 GHz) ESR spectrometer in dosimetry are also presented

  7. Influence of Water Absorption on Volume Resistivity and the Dielectric Properties of Neat Epoxy Material

    KAUST Repository

    Sulaimani, Anwar Ali

    2014-07-15

    Influence of Water Absorption on the Dielectric Properties and Volume Resistivity of Neat Epoxy Material Anwar Ali Sulaimani Epoxy resins are widely used materials in the industry as electrical insulators, adhesives and in aircrafts structural components because of their high mechanical sti ness, strength and high temperature and chemical resistance properties. But still, the in uence of water uptake due to moisture adsorption is not fully understood as it detrimentally modi es the electrical and chemical properties of the material. Here, we investigate the in uence of water moisture uptake on the neat epoxy material by monitoring the change in the volume resistivity and dielectric properties of epoxy material at three di erent thickness con gurations: 0.250 mm, 0.50 mm and 1 mm thicknesses. Gravimetric analysis was done to monitor the mass uptake behaviour, Volume Resistivity was measured to monitor the change in conductivity of the material, and the dielectric properties were mapped to characterise the type of water mechanism available within the material during two ageing processes of sorption and desorption. Two-stage behaviours of di usion and reaction have been identi ed by the mass uptake analysis. Moreover, the plot of volume resistivity versus mass uptake has indi- cated a non-uniform relationship between the two quantities. However, the analysis of the dielectric spectrum at medium range of frequency and time has showed a change 5 in the dipolar activities and also showed the extent to which the water molecules can be segregated between bounding to the resin or existing as free water.

  8. The dosimetry programme of the IAEA

    International Nuclear Information System (INIS)

    1987-01-01

    Describes the activities of the IAEA's Dosimetry Laboratory which provides calibration and comparison services for secondary standard dosimetry laboratories (SSDLs) of Member States. In addition, a joint IAEA/WHO postal dosimetry service has been established for radiotherapy centers. The International Measurement System and the calibration ''chain'' from measurement standard instruments of the International Bureau of Weights and Measurements (BIPM) through the primary and secondary standards to the dosimeters of the users are presented as well

  9. Large specific absorption rates in the magnetic hyperthermia properties of metallic iron nanocubes

    Energy Technology Data Exchange (ETDEWEB)

    Mehdaoui, B.; Meffre, A.; Lacroix, L.-M. [Universite de Toulouse, INSA, UPS, LPCNO (Laboratoire de Physique et Chimie des Nano-Objets), 135 avenue de Rangueil, F-31077 Toulouse (France); CNRS, UMR 5215, LPCNO, F-31077 Toulouse (France); Carrey, J., E-mail: julian.carrey@insa-toulouse.f [Universite de Toulouse, INSA, UPS, LPCNO (Laboratoire de Physique et Chimie des Nano-Objets), 135 avenue de Rangueil, F-31077 Toulouse (France); CNRS, UMR 5215, LPCNO, F-31077 Toulouse (France); Lachaize, S. [Universite de Toulouse, INSA, UPS, LPCNO (Laboratoire de Physique et Chimie des Nano-Objets), 135 avenue de Rangueil, F-31077 Toulouse (France); CNRS, UMR 5215, LPCNO, F-31077 Toulouse (France); Gougeon, M. [Institut CARNOT-CIRIMAT-UMR 5085, Batiment 2R1, 118 route de Narbonne, F-31062 Toulouse (France); Respaud, M. [Universite de Toulouse, INSA, UPS, LPCNO (Laboratoire de Physique et Chimie des Nano-Objets), 135 avenue de Rangueil, F-31077 Toulouse (France); CNRS, UMR 5215, LPCNO, F-31077 Toulouse (France); Chaudret, B. [Laboratoire de Chimie de Coordination-CNRS, 205 rte de Narbonne, 31077 Toulouse cedex 4 (France)

    2010-10-15

    We report on the magnetic hyperthermia properties of chemically synthesized ferromagnetic 11 and 16 nm Fe(0) nanoparticles of cubic shape displaying the saturation magnetization of bulk iron. The specific absorption rate measured on 16 nm nanocubes is 1690{+-}160 W/g at 300 kHz and 66 mT. This corresponds to specific losses-per-cycle of 5.6 mJ/g, largely exceeding the ones reported in other systems. A way to quantify the degree of optimization of any system with respect to hyperthermia applications is proposed. Applied here, this method shows that our nanoparticles are not fully optimized, probably due to the strong influence of magnetic interactions on their magnetic response. Once protected from oxidation and further optimized, such nano-objects could constitute efficient magnetic cores for biomedical applications requiring very large heating power.

  10. Investigation and measurement of radio thermoluminescence properties of some calci tic mollusc shells of the Persian Gulf and the Oman Sea (for γ radiation dosimetry)

    International Nuclear Information System (INIS)

    Ghafourian, H.; Rabbani, M.; Rouhi, U.

    2000-01-01

    Biogenic Calcium Carbonate, particularly as naturally thermoluminescent calci tic mollusc shells may serve as excellent radio thermoluminescent dosimeters. In this study the radio thermoluminescence properties of 8 different bivalves of the Persian Gulf, the Oman Sea and the internal calcite shell of Sepia sp. are investigated. The results of this investigation have shown that the shells of Sepia sp., Pinctata radiata and Card ita bicolor as appropriate dosimeters for both personal and industrial dosimetry purposes, among which Sepia sp. is the most sensitive one. Callista umbonella and Mactra sp. are relatively less thermoluminescent while Saccostrea Cucullata and Chlamys ruschenbergerii are completely inert with respect to γ - thermoluminescence. Thermoluminescence properties of Anadara refescens and Anadara secticostata decrease surprisingly by an increase in the absorbed dose of γ radiation, which can mainly be interpreted as the result of crystal lattice destruction caused by ionizing radiation

  11. A contribution to the study and development of radiothermoluminescent dosimetry

    International Nuclear Information System (INIS)

    Portal, Guy.

    1975-10-01

    The applications of radiothermoluminescence to radiation dosimetry were investigated. The fundamental processes are first reviewed and the main properties of radiothermoluminescence dosemeters are stated. The investigations carried out in order to have materials presenting particular dosimetric characteristics are then described: a lithium fluoride stabilized by sodium that can be reused without regeneration an alumina suitable for dosimetry in case of accident. Finally, the measurement of electromagnetic radiation in presence of neutrons of various energies are considered [fr

  12. Phosphorus absorption (32P) by apple trees under drip irrigation as influenced by the physical properties of the soil

    International Nuclear Information System (INIS)

    Habib, R.

    1983-01-01

    P absorption by apple tree roots (Golden delicious/M2) is studied using carrier-free 32 P. A qualitative model of the influence of some physical properties of the soil is proposed combining individual tree responses to 32 P injection. (orig.)

  13. The effect of texture unit shape on silicon surface on the absorption properties

    Energy Technology Data Exchange (ETDEWEB)

    Hua, Xiao-She; Zhang, Yi-Jie; Wang, Hao-Wei [Institute of Ecological and Environmental Materials, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2010-02-15

    Improving the utilization ratio of sunlight is a key factor for the development of solar cell. In this work, different structures including triangular pyramid, rectangular pyramid, hexangular pyramid and cone structure are established to investigate the influences of many factors, like geometrical shape, density and the top angle of the texture unit on silicon front surface to sunlight absorption. Ray-tracing technology is used for simulation. The simulation results indicate that the triangular pyramid texture on silicon front surface performs the best, and its total absorption rate is more than 90% for the light with wavelength between 640 and 1080 nm when the top angle of pyramid is less than 100 . (author)

  14. NOTE FROM THE DOSIMETRY SERVICE

    CERN Multimedia

    2002-01-01

    During March, the Dosimetry Service will be opened from 8h30 to 12h in the morning and closed every afternoon.   We have established that many people, who are provided regularly with a personal dosimeter (film badge), have changed their activity and do not need it anymore, because they do not, or only exceptionally, enter controlled areas. If you are one of these persons, please contact the Personal Dosimeter Service (tel: 72155). There is a simplified procedure for obtaining a dosimeter if you have an immediate need for short-term visits in controlled areas. A reduction of the number of persons on the regular distribution list of dosimeters would decrease our and the distributors workload. It would also contribute to significant savings in the dosimetry, and thus CERN, budget. We thank you in advance for your understanding and for your collaboration.

  15. The Latin American Biological Dosimetry Network (LBDNet).

    Science.gov (United States)

    García, O; Di Giorgio, M; Radl, A; Taja, M R; Sapienza, C E; Deminge, M M; Fernández Rearte, J; Stuck Oliveira, M; Valdivia, P; Lamadrid, A I; González, J E; Romero, I; Mandina, T; Guerrero-Carbajal, C; ArceoMaldonado, C; Cortina Ramírez, G E; Espinoza, M; Martínez-López, W; Di Tomasso, M

    2016-09-01

    Biological Dosimetry is a necessary support for national radiation protection programmes and emergency response schemes. The Latin American Biological Dosimetry Network (LBDNet) was formally founded in 2007 to provide early biological dosimetry assistance in case of radiation emergencies in the Latin American Region. Here are presented the main topics considered in the foundational document of the network, which comprise: mission, partners, concept of operation, including the mechanism to request support for biological dosimetry assistance in the region, and the network capabilities. The process for network activation and the role of the coordinating laboratory during biological dosimetry emergency response is also presented. This information is preceded by historical remarks on biological dosimetry cooperation in Latin America. A summary of the main experimental and practical results already obtained by the LBDNet is also included. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. In Vitro Characterization of the Biomimetic Properties of Poly(dimethylsiloxane) To Simulate Oral Drug Absorption.

    Science.gov (United States)

    Sinko, Patrick D; Gidley, David; Vallery, Richard; Lamoureux, Aaron; Amidon, Gordon L; Amidon, Gregory E

    2017-12-04

    The potential use of poly(dimethylsiloxane) (PDMS) as an in vitro biomimetic analogue of the passive drug absorption process in the human gastrointestinal tract (GI) is assessed. PDMS is biomimetic because of similarities in small molecule transport, such as mechanism, ionization selectivity, lipophilicity. Nine molecular probes are used to evaluate the transport pathways and properties used to predict human oral absorption rates. The transport pathways through PDMS (bulk/pore) are analogous to transcellular (TCDT) and paracellular (PCDT) drug transport pathways. PDMS PCDT is assessed using positronium annihilation lifetime spectroscopy (PALS) and partition experiments; TCDT using diffusion and partition experiments. PALS determined that PDMS pores were uniform (D ∼ 0.85 nm), isolated, and void volume was unaffected by drug accumulation after equilibrium partitioning. Therefore, there is no PCDT or convective flow through PDMS. A strong linear correlation exists between predicted octanol-water partition coefficients and PDMS partition coefficients (LogK PDMS = 0.736 × LogP O-W - 0.971, R 2 = 0.981). The pH-partition hypothesis is confirmed in PDMS using ibuprofen over pH 2-12. Diffusivity through PDMS is a function of lipophilicity and polar surface area K × D PDMS = 4.46 × 10 -8 × e 2.91×LogK PDMS (R 2 = 0.963) and [Formula: see text] (R 2 = 0.973). Varying the mass% of curing agent changed the lipophilicity and diffusivity (p < 0.02), but not practically (K × D = 2.23 × 10 -5 cm 2 s -1 vs 2.60 × 10 -5 cm 2 s -1 ), and does affect elastic modulus (3.2% = 0.3 MPa to 25% = 3.2 MPa).

  17. The Latin American Biological Dosimetry Network (LBDNet)

    International Nuclear Information System (INIS)

    Garcia, O.; Lamadrid, A.I.; Gonzalez, J.E.; Romero, I.; Mandina, T.; Di Giorgio, M.; Radl, A.; Taja, M.R.; Sapienza, C.E.; Deminge, M.M.; Fernandez Rearte, J.; Stuck Oliveira, M.; Valdivia, P.; Guerrero-Carbajal, C.; Arceo Maldonado, C.; Cortina Ramirez, G.E.; Espinoza, M.; Martinez-Lopez, W.; Di Tomasso, M.

    2016-01-01

    Biological Dosimetry is a necessary support for national radiation protection programmes and emergency response schemes. The Latin American Biological Dosimetry Network (LBDNet) was formally founded in 2007 to provide early biological dosimetry assistance in case of radiation emergencies in the Latin American Region. Here are presented the main topics considered in the foundational document of the network, which comprise: mission, partners, concept of operation, including the mechanism to request support for biological dosimetry assistance in the region, and the network capabilities. The process for network activation and the role of the coordinating laboratory during biological dosimetry emergency response is also presented. This information is preceded by historical remarks on biological dosimetry cooperation in Latin America. A summary of the main experimental and practical results already obtained by the LBDNet is also included. (authors)

  18. Improving the Electromagnetic Wave Absorption Properties of the Layered MoS2 by Cladding with Ni Nanoparticles

    Science.gov (United States)

    Zhang, Zilong; Wang, Zilin; Heng, Liuyang; Wang, Shuai; Chen, Xiqiao; Fu, Xiquan; Zou, Yanhong; Tang, Zhixiang

    2018-05-01

    MoS2 is a promising material with microwave absorption performance due to its high dielectric properties and low density. However, pure MoS2 is non-magnetic and has a bad impedance matching characteristic. In this study we prepared the Ni/MoS2 nanocomposites by cladding the MoS2 micrometer slices with magnetic Ni nanoparticles. Our results show that the microwave absorption properties of Ni/MoS2 nanocomposites have been improved obviously compared with the pure MoS2. Because of the introduction of Ni particles, the permeability of the nanocomposites has been turned from one to a complex, indicating a newly added magnetic loss. Meanwhile, the big gap between the permittivity and permeability of the Ni/MoS2 nanocomposites has been properly narrowed, which suggests an improved impedance matching. Moreover, the dielectric Cole-Cole semicircle shows that there are more Debye relaxation processes for the Ni/MoS2 nanocomposites, which further enhances the dielectric loss. Due to its improved electromagnetic properties, the minimum reflection loss (RL) value of the Ni/MoS2 nanocomposites with 60 wt % loading reaches -55 dB and the absorption bandwidth (<-10 dB) is up to 4.0 GHz (10.8-14.8 GHz) with a matching thickness of 1.5 mm. The results provide an excellent candidate for microwave absorbing materials with a broad effective absorption bandwidth at thin thicknesses.

  19. Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Hurst, G S; Ritchie, R H; Sanders, F W; Reinhardt, P W; Auxier, J A; Wagner, E B; Callihan, A D; Morgan, K Z [Health Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1962-03-15

    The methods of dosimetry used for investigation of the doses received by the individuals exposed in the Yugoslav accident were essentially those used in connection with the Oak Ridge Y-12 accident. An outline of the general scheme is as follows: When fast neutrons enter the human body, most of these are moderated to thermal energy and a small fraction of these are captured by a (n, gamma) process in Na sup 2 sup 3 , giving rise to Na sup 2 sup 4 , which by virtue of its emission of high-energy gamma rays with a half life of 14.8 h, is easily detected. It has been shown that the probability of capture, making Na sup 2 sup 4 , is not a strong function of the energy of the fast neutrons and that the probability of capture for neutrons is higher in the fast region than in the thermal region. Thus, the uniform distribution of Na sup 2 sup 3 in the human body provides an excellent means of normalizing the neutron exposure of an individual. in particular, for a given neutron energy spectrum the fast neutron dose is proportional to the ratio Na sup 2 sup 4 /Na sup 2 sup 3 in the body or in the blood system. This method of normalization is quite important in the dosimetry of radiation accidents since no assumptions need be made about the exact location of an individual at the time of the energy release. The importance of this fact can be made clear by reference to the Y-12 accident where it was shown by calculation of the neutron dose based on the known number of fissions and the stated location of the individual that one of the surviving individuals would have received a dose several times the lethal value. To accomplish the measurements described, the zero power R sub B reactor was operated in two ranges of power level, 'low' power and 'high 'power. Neutron leakage spectrum was obtained by multigroup approximation of the Boltzmann transport equation. Prompt gamma rays from fission products, from capture in the moderator and fuel cladding as well as in tank walls are given

  20. Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Hurst, G S; Ritchie, R H; Sanders, F W; Reinhardt, P W; Auxier, J A; Wagner, E B; Callihan, A D; Morgan, K Z [Health Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1962-03-01

    The methods of dosimetry used for investigation of the doses received by the individuals exposed in the Yugoslav accident were essentially those used in connection with the Oak Ridge Y-12 accident. An outline of the general scheme is as follows: When fast neutrons enter the human body, most of these are moderated to thermal energy and a small fraction of these are captured by a (n, {gamma}) process in Na{sup 23}, giving rise to Na{sup 24}, which by virtue of its emission of high-energy gamma rays with a half life of 14.8 h, is easily detected. It has been shown that the probability of capture, making Na{sup 24}, is not a strong function of the energy of the fast neutrons and that the probability of capture for neutrons is higher in the fast region than in the thermal region. Thus, the uniform distribution of Na{sup 23} in the human body provides an excellent means of normalizing the neutron exposure of an individual. in particular, for a given neutron energy spectrum the fast neutron dose is proportional to the ratio Na{sup 24}/Na{sup 23} in the body or in the blood system. This method of normalization is quite important in the dosimetry of radiation accidents since no assumptions need be made about the exact location of an individual at the time of the energy release. The importance of this fact can be made clear by reference to the Y-12 accident where it was shown by calculation of the neutron dose based on the known number of fissions and the stated location of the individual that one of the surviving individuals would have received a dose several times the lethal value. To accomplish the measurements described, the zero power R{sub B} reactor was operated in two ranges of power level, 'low' power and 'high 'power. Neutron leakage spectrum was obtained by multigroup approximation of the Boltzman transport equation. Prompt gamma rays from fission products, from capture in the moderator and fuel cladding as well as in tank walls are given. A summary of the 4{pi

  1. Proceedings of the 5. symposium on neutron dosimetry. Beam dosimetry

    International Nuclear Information System (INIS)

    Schraube, H.; Burger, G.; Booz, J.

    1985-01-01

    Proceedings of the fifth symposium on neutron dosimetry, organized at Neuherberg, 17-21 September 1984, by the Commission of the European Communities and the GSF Neuherberg, with the co-sponsorship of the US Department of Energy, Office of Health and Environmental Research. The proceedings deal with research on concepts, instruments and methods in radiological protection for neutrons and mixed neutron-gamma fields, including the generation, collection and evaluation of new dosimetric data, the derivation of relevant radiation protection quantitites, and the harmonization of experimental methods and instrumentation by intercomparison programmes. Besides radiation protection monitoring, the proceedings also report on the improvement of neutron beam dosimetry in the fields of radiobiology and radiation therapy

  2. Proportion-corrected scaled voxel models for Japanese children and their application to the numerical dosimetry of specific absorption rate for frequencies from 30 MHz to 3 GHz

    International Nuclear Information System (INIS)

    Nagaoka, Tomoaki; Watanabe, Soichi; Kunieda, Etsuo

    2008-01-01

    The development of high-resolution anatomical voxel models of children is difficult given, inter alia, the ethical limitations on subjecting children to medical imaging. We instead used an existing voxel model of a Japanese adult and three-dimensional deformation to develop three voxel models that match the average body proportions of Japanese children at 3, 5 and 7 years old. The adult model was deformed to match the proportions of a child by using the measured dimensions of various body parts of children at 3, 5 and 7 years old and a free-form deformation technique. The three developed models represent average-size Japanese children of the respective ages. They consist of cubic voxels (2 mm on each side) and are segmented into 51 tissues and organs. We calculated the whole-body-averaged specific absorption rates (WBA-SARs) and tissue-averaged SARs for the child models for exposures to plane waves from 30 MHz to 3 GHz; these results were then compared with those for scaled down adult models. We also determined the incident electric-field strength required to produce the exposure equivalent to the ICNIRP basic restriction for general public exposure, i.e., a WBA-SAR of 0.08 W kg -1 .

  3. Easily Dispersible NiFe2O4/RGO Composite for Microwave Absorption Properties in the X-Band

    Science.gov (United States)

    Bateer, Buhe; Zhang, Jianjao; Zhang, Hongchen; Zhang, Xiaochen; Wang, Chunyan; Qi, Haiqun

    2018-01-01

    Composites with good dispersion and excellent microwave absorption properties have important applications. Therefore, an easily dispersible NiFe2O4/reduced graphene oxide (RGO) composite has been prepared conveniently through a simple hydrothermal method. Highly crystalline, small size (about 7 nm) monodispersed NiFe2O4 nanoparticles (NPs) are evenly distributed on the surface of RGO. The microwave absorbability revealed that the NiFe2O4/RGO composite exhibits excellent microwave absorption properties in the X-band (8-12 GHz), and the minimum reflection loss of the NiFe2O4/RGO composite is -27.7 dB at 9.2 GHz. The NiFe2O4/RGO composite has good dispersibility in nonpolar solvent, which facilitates the preparation of stable commercial microwave absorbing coatings. It can be a promising candidate for lightweight microwave absorption materials in many application fields.

  4. Thermoluminescent properties of CVD diamond: applications to ionising radiation dosimetry

    International Nuclear Information System (INIS)

    Petitfils, A.

    2007-09-01

    Remarkable properties of synthetic diamond (human soft tissue equivalence, chemical stability, non-toxicity) make this material suitable for medical application as thermoluminescent dosimeter (TLD). This work highlights the interest of this material as radiotherapy TLD. In the first stage of this work, we looked after thermoluminescent (TL) and dosimetric properties of polycrystalline diamond made by Chemically Vapor Deposited (CVD) synthesis. Dosimetric characteristics are satisfactory as TLD for medical application. Luminescence thermal quenching on diamond has been investigated. This phenomenon leads to a decrease of dosimetric TL peak sensitivity when the heating rate increases. The second part of this work analyses the use of synthetic diamond as TLD in radiotherapy. Dose profiles, depth dose distributions and the cartography of an electron beam obtained with our samples are in very good agreement with results from an ionisation chamber. It is clearly shown that CVD) diamond is of interest to check beams of treatment accelerators. The use of these samples in a control of treatment with Intensity Modulated Radiation Therapy underlines good response of synthetic diamond in high dose gradient areas. These results indicate that CVD diamond is a promising material for radiotherapy dosimetry. (author)

  5. Microwave absorption properties of the core/shell-type iron and nickel nanoparticles

    International Nuclear Information System (INIS)

    Lu, B.; Dong, X.L.; Huang, H.; Zhang, X.F.; Zhu, X.G.; Lei, J.P.; Sun, J.P.

    2008-01-01

    Iron (Fe) and nickel (Ni) nanoparticles were prepared by the DC arc-discharge method in a mixture of hydrogen and argon gases, using bulk metals as the raw materials. The microstructure of core/shell (metal/metal oxide) in nanoparticle formed after in situ passivation process. The complex electromagnetic parameters (permittivity ε r =ε r ' +iε r '' and permeability μ r =μ r ' +iμ r '' ) of the paraffin-mixed nanocomposite samples (paraffin:nanoparticles=1:1 in mass ratio) were measured in the frequency range of 2-18 GHz. The polarization mechanisms of the space charge and dipole coexist in both the Fe and Ni nanoparticles. The orientational polarization is a particular polarization for Fe nanoparticles and brings a relatively higher dielectric loss. Natural resonance is the main reason for magnetic loss and the corresponding frequencies are 11.6 and 5.2 GHz for the Fe and Ni nanoparticles, respectively. The paraffin composite with Fe nanoparticles provided excellent microwave absorption properties (reflection loss <-20 dB) in the range 6.8-16.6 GHz over the absorber thickness of 1.1-2.3 mm

  6. Microwave absorption properties of the core/shell-type iron and nickel nanoparticles

    Science.gov (United States)

    Lu, B.; Dong, X. L.; Huang, H.; Zhang, X. F.; Zhu, X. G.; Lei, J. P.; Sun, J. P.

    Iron (Fe) and nickel (Ni) nanoparticles were prepared by the DC arc-discharge method in a mixture of hydrogen and argon gases, using bulk metals as the raw materials. The microstructure of core/shell (metal/metal oxide) in nanoparticle formed after in situ passivation process. The complex electromagnetic parameters (permittivity ɛ=ɛr'+iɛr″ and permeability μ=μr'+iμr″) of the paraffin-mixed nanocomposite samples (paraffin:nanoparticles=1:1 in mass ratio) were measured in the frequency range of 2-18 GHz. The polarization mechanisms of the space charge and dipole coexist in both the Fe and Ni nanoparticles. The orientational polarization is a particular polarization for Fe nanoparticles and brings a relatively higher dielectric loss. Natural resonance is the main reason for magnetic loss and the corresponding frequencies are 11.6 and 5.2 GHz for the Fe and Ni nanoparticles, respectively. The paraffin composite with Fe nanoparticles provided excellent microwave absorption properties (reflection loss <-20 dB) in the range 6.8-16.6 GHz over the absorber thickness of 1.1-2.3 mm.

  7. Impact of chemical treatments on the mechanical and water absorption properties of coconut fibre (Cocos nucifera reinforced polypropylene composites

    Directory of Open Access Journals (Sweden)

    Isiaka O. OLADELE

    2016-07-01

    Full Text Available In this work, chemically treated coconut fibres were used to reinforce Homopolymer Polypropylene in order to ascertain the effect of the treatments on the mechanical and water absorption properties of the composites produced. Coconut fibre was first extracted from its husk by soaking it in water and was dried before it was cut into 10 mm lengths. It was then chemically treated in alkali solution of sodium hydroxide (NaOH and potassium hydroxide (KOH in a shaker water bath. The treated coconut fibres were used as reinforcements in polypropylene matrix to produce composites of varied fibre weight contents; 2, 4, 6, 8 and 10 wt.%. Tensile and flexural properties were investigated using universal testing machine while water absorption test was carried out on the samples for 7 days. It was observed from the results that, NaOH treated samples gave the best tensile properties while KOH treated samples gave the best flexural and water repellent properties.

  8. Effect of Guar Gum with Sorbitol Coating on the Properties and Oil Absorption of French Fries.

    Science.gov (United States)

    Jia, Bo; Fan, Daming; Li, Jinwei; Duan, Zhenhua; Fan, Liuping

    2017-12-13

    This paper investigated the effects of guar gum with sorbitol coating on the oil absorption of French fries by combined dye oil methods, confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). The results showed that pretreatment of blanching with calcium ions and coating with guar gum and sorbitol could significantly reduce the structural oil (STO) and penetrated surface oil (PSO) of French fries and have no negative effects on its texture and also effectively control the final moisture content ( p French fries with guar gum and sorbitol reduced by 50.8%, 33.1% and 30.6%, respectively. CLSM photographs confirmed that STO significantly reduced after coating with guar gum and sorbitol, followed by PSO. In the process of frying, the coatings of guar gum or guar gum with sorbitol could effectively prevent oil from infiltrating the potato tissue, which can be seen in the SEM photographs. The barrier properties of French fries were enhanced by coating guar gum, and sorbitol was added to avoid pores and cracks. Blanching with calcium ion can significantly reduce the final moisture content of coating French fries.

  9. [Near ultraviolet absorption spectral properties of chromophoric dissolved organic matter in the north area of Yellow Sea].

    Science.gov (United States)

    Wang, Lin; Zhao, Dong-Zhi; Yang, Jian-Hong; Chen, Yan-Long

    2010-12-01

    Chromophoric dissolved organic matter (CDOM) near ultraviolet absorption spectra contains CDOM molecular structure, composition and other important physical and chemical information. Based on the measured data of CDOM absorption coefficient in March 2009 in the north area of Yellow Sea, the present paper analyzed near ultraviolet absorption spectral properties of CDOM. The results showed that due to the impact of near-shore terrigenous input, the composition of CDOM is quite different in the north area of Yellow Sea, and this area is a typical case II water; fitted slope with specific range of spectral band and absorption coefficient at specific band can indicate the relative size of CDOM molecular weight, correlation between spectral slope of the Sg,275-300), Sg,300-350, Sg,350-400 and Sg,250-275 and the relative size of CDOM molecular weight indicative parameter M increases in turn and the highest is up to 0.95. Correlation between a(g)(lambda) and M value increases gradually with the increase in wavelength, and the highest is up to 0.92 at 400 nm; being correlated or not between spectral slope and absorption coefficient is decided by the fitting-band wavelength range for the spectra slope and the wavelength for absorption coefficient. Correlation between Sg,275-300 and a(g)(400) is the largest, up to 0.87.

  10. Theoretical modeling of the spectroscopic absorption properties of luciferin and oxyluciferin: A critical comparison with recent experimental studies

    Energy Technology Data Exchange (ETDEWEB)

    Anselmi, Massimiliano, E-mail: m.anselmi@caspur.it [Department of Chemistry, University of Rome ' La Sapienza' , P.le Aldo Moro 5, 00185 Rome (Italy); Marocchi, Simone [Department of Chemistry, University of Rome ' La Sapienza' , P.le Aldo Moro 5, 00185 Rome (Italy); Aschi, Massimiliano [Department of Chemistry, Chemical Engineering and Materials, University of L' Aquila, Via Vetoio (Coppito 1), 67100 Coppito, L' Aquila (Italy); Amadei, Andrea [Department of Chemistry, University of Rome ' Tor Vergata' , Via della Ricerca Scientifica 1, 00133 Rome (Italy)

    2012-01-02

    Highlights: Black-Right-Pointing-Pointer The calculated absorption spectra were compared with experimental data. Black-Right-Pointing-Pointer Shapes and absorption maxima were reproduced for luciferin and oxyluciferin spectra. Black-Right-Pointing-Pointer The effect of the solvent largely changes the electronic transition probabilities. Black-Right-Pointing-Pointer Higher excitations provide an important contribution to the main absorption peak. - Abstract: Firefly luciferin and its oxidated form, oxyluciferin, are two heterocyclic compounds involved in the enzymatic reaction, catalyzed by redox proteins called luciferases, which provides the bioluminescence in a wide group of arthropods. Whereas the electronic absorption spectra of D-luciferin in water at different pHs are known since 1960s, only recently reliable experimental electronic spectra of oxyluciferin have become available. In addition oxyluciferin is involved in a triple chemical equilibria (deprotonation of the two hydroxyl groups and keto-enol tautomerism of the 4-hydroxythiazole ring), that obligates to select during an experiment a predominant species, tuning pH or solvent polarity besides introducing chemical modifications. In this study we report the absorption spectra of luciferin and oxyluciferin in each principal chemical form, calculated by means of perturbed matrix method (PMM), which allowed us to successfully introduce the effect of the solvent on the spectroscopic absorption properties, and compare the result with available experimental data.

  11. Dosimetry Control: Technic and methods. Proceedings of the international workshop 'Actual problems of dosimetry'

    International Nuclear Information System (INIS)

    Lyutsko, A.M.; Nesterenko, V.B.; Chudakov, V.A.; Konoplya, E.F.; Milyutin, A.A.

    1997-10-01

    There is a number of unsolved problems of both dosimetric and radiometric control, questions of the biological dosimetry, reconstruction of dozes of irradiation of the population at radiation incidents, which require coordination of efforts of scientists in various areas of a science. The submitted materials are grouped on five units: dosimetry engineering, biological dosimetry and markers of radiation impact, dosimetry of a medical irradiation, normative and measurement assurance of the dosimetric control, monitoring and reconstruction of dozes at radiation incidents

  12. The internal dosimetry code PLEIADES.

    Science.gov (United States)

    Fell, T P; Phipps, A W; Smith, T J

    2007-01-01

    The International Commission on Radiological Protection (ICRP) has published dose coefficients for the ingestion or inhalation of radionuclides in a series of reports covering intakes by workers and members of the public, including children and pregnant or lactating women. The calculation of these coefficients divides naturally into two distinct parts-the biokinetic and dosimetric. This paper describes in detail the methods used to solve the biokinetic problem in the generation of dose coefficients on behalf of the ICRP, as implemented in the Health Protection Agency's internal dosimetry code PLEIADES. A summary of the dosimetric treatment is included.

  13. The internal dosimetry code PLEIADES

    International Nuclear Information System (INIS)

    Fell, T. P.; Phipps, A. W.; Smith, T. J.

    2007-01-01

    The International Commission on Radiological Protection (ICRP) has published dose coefficients for the ingestion or inhalation of radionuclides in a series of reports covering intakes by workers and members of the public, including children and pregnant or lactating women. The calculation of these coefficients divides naturally into two distinct parts - the biokinetic and dosimetric. This paper describes in detail the methods used to solve the biokinetic problem in the generation of dose coefficients on behalf of the ICRP, as implemented in the Health Protection Agency's internal dosimetry code PLEIADES. A summary of the dosimetric treatment is included. (authors)

  14. Effect of the bio-absorbent on the microwave absorption property of the flaky CIPs/rubber absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Yang; Xu, Yonggang, E-mail: xuyonggang221@163.com; Cai, Jun; Yuan, Liming; Zhang, Deyuan

    2015-09-01

    Microwave absorbing composites filled with flaky carbonyl iron particles (CIPs) and the bio-absorbent were prepared by using a two-roll mixer and a vulcanizing machine. The electromagnetic (EM) parameters were measured by a vector network analyzer and the reflection loss (RL) was measured by the arch method in the frequency range of 1–4 GHz. The uniform dispersion of the absorbents was verified by comparing the calculated RL with the measured one. The results confirm that as the bio-absorbent was added, the permittivity was increased due to the volume content of absorbents, and the permeability was enlarged owing to the volume content of CIPs and interactions between the two absorbents. The composite filled with bio-absorbents achieved an excellent absorption property at a thickness of 1 mm (minimum RL reaches −7.8 dB), and as the RL was less than −10 dB the absorption band was widest (2.1–3.8 GHz) at a thickness of 2 mm. Therefore, the bio-absorbent is a promising additive candidate on fabricating microwave absorbing composites with a thinner thickness and wider absorption band. - Graphical abstract: Morphology of composites filled with flaky CIPs and the bio-absorbent. The enhancement of bio-absorbent on the electromagnetic absorption property of composites filled with flaky carbonyl iron particles (CIPs) is attributed to the interaction of the two absorbents. The volume content of the FCMPs with the larger shape CIPs play an important role in this effects, the composites filled with irons and bio-absorbents can achieve wider-band and thinner-thickness absorbing materials. - Highlights: • Absorbers filled with bio-absorbents and CIPs was fabricated. • Bio-absorbents enhanced the permittivity and permeability of the composites. • The absorbent interactions play a key role in the enhancement mechanism. • Bio-absorbents enhanced the composite RL in 1–4 GHz.

  15. The RERF dosimetry measurements database

    International Nuclear Information System (INIS)

    Cullings, Harry M.; Fujita, Shoichiro; Preston, Dale L.; Grant, Eric J.; Shizuma, Kiyoshi; Hoshi, Masaharu; Maruyama, Takashi; Lowder, Wayne M.

    2005-01-01

    The Radiation Effects Research Foundation maintains a database containing detailed information on every known measurement of environmental materials in the cities of Hiroshima and Nagasaki for gamma-ray thermoluminescence or neutron activation produced by incident radiation from the atomic bomb detonations. The intent was to create a single information resource that would consistently document, as completely as possible in each case, a standard array of data for every known measurement. This database provides a uniquely comprehensive and carefully designed reference for the dosimetry reassessment. (J.P.N.)

  16. The Future of Medical Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Robert D., E-mail: robert_adams@med.unc.edu

    2015-07-01

    The world of health care delivery is becoming increasingly complex. The purpose of this manuscript is to analyze current metrics and analytically predict future practices and principles of medical dosimetry. The results indicate five potential areas precipitating change factors: a) evolutionary and revolutionary thinking processes, b) social factors, c) economic factors, d) political factors, and e) technological factors. Outcomes indicate that significant changes will occur in the job structure and content of being a practicing medical dosimetrist. Discussion indicates potential variables that can occur within each process and change factor and how the predicted outcomes can deviate from normative values. Finally, based on predicted outcomes, future opportunities for medical dosimetrists are given.

  17. Radiation accident dosimetry: TL properties of mobile phone screen glass

    International Nuclear Information System (INIS)

    Bassinet, C.; Pirault, N.; Baumann, M.; Clairand, I.

    2014-01-01

    Mobile phones are carried by a large part of the population and previous studies have shown that they may be able to function as individual fortuitous dosimeters in case of radiological accident. This study deals with thermoluminescence (TL) properties of mobile phone screen glass. The presence of a significant background signal which partially overlaps with the radiation-induced signal is a serious issue for dose reconstruction. A mechanical method to reduce this signal using a diamond grinding bit is presented. An over-response at low energy (∼50 keV) is observed for two investigated glasses. The results of a dose recovery test using a single-aliquot regenerative-dose (SAR) procedure are discussed. - Highlights: • Mobile phone screen glass is a promising material for retrospective dosimetry. • The TL non-radiation induced background signal can be significantly reduced by a mechanical method. • A dose recovery test using an SAR procedure was successfully carried out for the investigated glass

  18. Investigating the influence of alkalization on the mechanical and water absorption properties of coconut and sponge fibers reinforced polypropylene composites

    Directory of Open Access Journals (Sweden)

    Okikiola Ganiu AGBABIAKA

    2014-11-01

    Full Text Available Natural fibers are products made from renewable agricultural and forestry feedstock, which can include wood, grasses, and crops, as well as wastes and residues. There are two primary ways these fibers are used: to create polymers or as reinforcement and filler. Thermoplastic polymer may be reinforced or filled using natural fibers such as coir, sponge, hemp, flax, or sisal. This paper focused on the influence of alkalization (NaOH treatment on the mechanical and water absorption properties of selected natural fibers (coconut and sponge fibers reinforced polypropylene composites. In this study, coconut and sponge fiber were extracted from its husk by soaking them in water and was dried before it was cut into 10mm length. Those fibers were chemically treated with sodium hydroxide (NaOH in a shaking water bath before it was used as reinforcement in polypropylene composite. The reinforced polypropylene composite was produced by dispersing the coconut fibers randomly in the polypropylene before it was fabricated in a compression molding machine where the composite was produced. The fiber content used were; 2%wt, 4%wt, 6%wt, 8%wt and 10%wt. Tensile and flexural properties was observed from universal testing machine while water absorption test was carried out on the samples for seven (7 days. It was observed that the influence of NaOH treatment highly enhanced the Flexural and water absorption properties of sponge fiber reinforced polypropylene composites than coconut fiber reinforced composite samples.

  19. Investigating the influence of alkalization on the mechanical and water absorption properties of coconut and sponge fibers reinforced polypropylene composites

    OpenAIRE

    Okikiola Ganiu AGBABIAKA; Isiaka Oluwole OLADELE; Paul Toluwalagbara OLORUNLEYE

    2014-01-01

    Natural fibers are products made from renewable agricultural and forestry feedstock, which can include wood, grasses, and crops, as well as wastes and residues. There are two primary ways these fibers are used: to create polymers or as reinforcement and filler. Thermoplastic polymer may be reinforced or filled using natural fibers such as coir, sponge, hemp, flax, or sisal. This paper focused on the influence of alkalization (NaOH treatment) on the mechanical and water absorption properties o...

  20. Water absorption and its effect on the tensile properties of tapioca starch/polyvinyl alcohol bioplastics

    NARCIS (Netherlands)

    Judawisastra, H.; Sitohang, Ramona; Marta, L.; Mardiyati,

    2017-01-01

    Tapioca is one of the largest sources of starch and makes it suitable to be used for bioplastic material. Addition of polyvinyl alcohol (PVA) has been shown to successfully reduce the brittleness of starch bioplastic. This study aims to investigate the influence of PVA addition to water absorption

  1. Dosimetry system of the RB reactor

    International Nuclear Information System (INIS)

    Lolic, B.; Vukadin, D.

    1962-01-01

    Although RB reactor is operated at very low power levels, safety and dosimetry systems have high importance. This paper shows detailed dosimetry system with fundamental typical components. Estimated radiation doses dependent on reactor power are given at some characteristic points in the rooms nearby reactor

  2. Evolution of Multispectral Aerosol Absorption Properties in a Biogenically-Influenced Urban Environment during the CARES Campaign

    Energy Technology Data Exchange (ETDEWEB)

    Gyawali, Madhu; Arnott, W.; Zaveri, Rahul; Song, Chen; Flowers, Bradley; Dubey, Manvendra; Setyan, Ari; Zhang, Qi; China, Swarup; Mazzoleni, Claudio; Gorkowski, Kyle; Subramanian, R.; Moosmüller, Hans

    2017-11-01

    We present the evolution of multispectral optical properties as urban aerosols aged and interacted with biogenic emissions resulting in stronger short wavelength absorption and formation of moderately brown secondary organic aerosols. Ground-based aerosol measurements were made during June 2010 within the Sacramento urban area (site T0) and at a 40-km downwind location (site T1) in the forested Sierra Nevada foothills area. Data on black carbon and non-refractory aerosol mass and composition were collected at both sites. In addition, photoacoustic (PA) instruments with integrating nephelometers were used to measure spectral absorption and scattering coefficients for wavelengths ranging from 355 to 870 nm. The daytime absorption Ångström exponent (AAE) indicated a modest wavelength-dependent enhancement of absorption at both sites throughout the study. From the 22nd to the 28th of June, secondary organic aerosol mass increased significantly at both sites due to increased biogenic emissions coupled with intense photochemical activity and air mass recirculation in the area. During this period, the median BC mass-normalized absorption cross-section (MAC) values for 405 nm and 532 nm at T1 increased by ~23% and ~35%, respectively, compared to the relatively less aged urban emissions at the T0 site. In contrast, the average MAC values for the 870 nm wavelength were similar for both sites. These results suggest formation of moderately brown secondary organic aerosols in biogenically-influenced urban air.

  3. Sensitivity of light interaction computer model to the absorption properties of skin

    Science.gov (United States)

    Karsten, A. E.; Singh, A.

    2011-06-01

    Light based treatments offer major benefits to patients. Many of the light based treatments or diagnostic techniques need to penetrate the skin to reach the site of interest. Human skin is a highly scattering medium and the melanin in the epidermal layer of the skin is a major absorber of light in the visible and near infrared wavelength bands. The effect of increasing absorption in the epidermis is tested on skin simulating phantoms as well as on a computer model. Changing the absorption coefficient between 0.1 mm-1 and 1.0 mm-1 resulted in a decrease of light reaching 1 mm into the sample. Transmission through a 1 mm thick sample decreased from 48% to 13% and from 31% to 2% for the different scattering coefficients.

  4. Radiation dosimetry and standards at the austrian dosimetry laboratory

    International Nuclear Information System (INIS)

    Leitner, A.

    1984-10-01

    The Austrian Dosimetry Laboratory, established and operated in cooperation between the Austrian Research Center Seibersdorf and the Federal Office of Metrology and Surveying (Bundesamt and Eich- und Vermessungswesen) maintains the national primary standards for radiation dosimetry. Furthermore its tasks include routine calibration of dosemeters and dosimetric research. The irradiation facilities of the laboratory comprise three X-ray machines covering the voltage range from 5 kV to 420 kV constant potential, a 60 Co teletherapy unit, a circular exposure system for routine batch calibration of personnel dosemeters with four gamma ray sources ( 60 Co and 137 Cs) and a reference source system with six gamma ray sources ( 60 Co and 137 Cs). In addition a set of calibrated beta ray sources are provided ( 147 Pm, 204 Tl and 90 Sr). The dosimetric equipment consists of three free-air parallelplate ionization chambers serving as primary standards of exposure for the X-ray energy region, graphite cavity chambers with measured volume as primary standards for the gamma radiation of 137 Cs and 60 Co as well as different secondary standard ionization chambers covering the dose rate range from the natural background level up to the level of modern therapy accelerators. In addition for high energy photon and electron radiation a graphite calorimeter is provided as primary standard of absorbed dose. The principle experimental set-ups for the practical use of the standards are presented and the procedures for the calibration of the different types of dosemeters are described. (Author)

  5. The French dosimetry protocol

    International Nuclear Information System (INIS)

    Dutreix, A.

    1985-01-01

    After a general introduction the protocol is divided in five sections dealing with: determination of the quality of X-ray, γ-ray and electron beams; the measuring instrument; calibration of the reference instrument; determination of the reference absorbed dose in the user's beams; determination of the absorbed dose in water at other points, in other conditions. The French protocol is not essentially different from the Nordic protocol and it is based on the experience gained in using both the American and the Nordic protocols. Therefore, only the main difference with the published protocols are discussed. (Auth.)

  6. Hydrogen absorption/desorption properties in the TiCrV based alloys

    Directory of Open Access Journals (Sweden)

    A. Martínez

    2012-10-01

    Full Text Available Three different Ti-based alloys with bcc structure and Laves phase were studied. The TiCr1.1V0.9, TiCr1.1V0.45Nb0.45 and TiCr1.1V0.9 + 4%Zr7Ni10 alloys were melted in arc furnace under argon atmosphere. The hydrogen absorption capacity was measured by using aparatus type Sievert's. Crystal structures, and the lattice parameters were determined by using X-ray diffraction, XRD. Microestructural analysis was performed by scanning electron microscope, SEM and electron dispersive X-ray, EDS. The hydrogen storage capacity attained a value of 3.6 wt. (% for TiCr1.1V0.9 alloy in a time of 9 minutes, 3.3 wt. (% for TiCr1.1V0.45Nb0.45 alloy in a time of 7 minutes and 3.6 wt. (% TiCr1.1V0.9 + 4%Zr7Ni10 with an increase of the hydrogen absorption kinetics attained in 2 minutes. This indicates that the addition of Nb and 4%Zr7Ni10 to the TiCrV alloy acts as catalysts to accelerate the hydrogen absorption kinetics.

  7. The influence of multiscale fillers reinforcement into impact resistance and energy absorption properties of polyamide 6 and polypropylene nanocomposite structures

    International Nuclear Information System (INIS)

    Silva, Francesco; Njuguna, James; Sachse, Sophia; Pielichowski, Krzysztof; Leszczynska, Agnieszka; Giacomelli, Marco

    2013-01-01

    Highlights: ► Significant improvement in PA composites impact resistance performance. ► Decrease in energy absorption capabilities of PP, this phenomenon is explained. ► Positive effects on mechanical and interphase properties of the matrix material. ► Transition from brittle to ductile fracture mode established. ► Two different toughening mechanisms were observed and explained. - Abstract: Three-phase composites (thermoplastic polymer, glass-fibres and nano-particles) were investigated as an alternative to two-phase (polymer and glass-fibres) composites. The effect of matrix and reinforcement material on the energy absorption capabilities of composite structures was studied in details in this paper. Dynamic and quasi-static axial collapse of conical structures was conducted using a high energy drop tower, as well as Instron universal testing machine. The impact event was recorded using a high-speed camera and the fracture surface was investigated with scanning electron microscopy (SEM). Attention was directed towards the relation between micro and macro fracture process with crack propagation mechanism and energy absorbed by the structure. The obtained results indicated an important influence of filler and matrix material on the energy absorption capabilities of the polymer composites. A significant increase in specific energy absorption (SEA) was observed in polyamide 6 (PA6) reinforced with nano-silica particles and glass-spheres, whereas addition of montmorillonite (MMT) caused a decrease in that property. On the other hand, very little influence of the secondary reinforcement on the energy absorption capabilities of polypropylene (PP) composites was found

  8. The mechanism and properties of bio-photon emission and absorption in protein molecules in living systems

    Science.gov (United States)

    Pang, Xiao-feng

    2012-05-01

    The mechanism and properties of bio-photon emission and absorption in bio-tissues were studied using Pang's theory of bio-energy transport, in which the energy spectra of protein molecules are obtained from the discrete dynamic equation. From the energy spectra, it was determined that the protein molecules could both radiate and absorb bio-photons with wavelengths of energy level transitions of the excitons. These results were consistent with the experimental data; this consisted of infrared absorption data from collagen, bovine serum albumin, the protein-like molecule acetanilide, plasma, and a person's finger, and the laser-Raman spectra of acidity I-type collagen in the lungs of a mouse, and metabolically active Escherichia coli. We further elucidated the mechanism responsible for the non-thermal biological effects produced by the infrared light absorbed by the bio-tissues, using the above results. No temperature rise was observed; instead, the absorbed infrared light promoted the vibrations of amides as well the transport of the bio-energy from one place to other in the protein molecules, which changed their conformations. These experimental results, therefore, not only confirmed the validity of the mechanism of bio-photon emission, and the newly developed theory of bio-energy transport mentioned above, but also explained the mechanism and properties of the non-thermal biological effects produced by the absorption of infrared light by the living systems.

  9. Effect of co-doping of sodium on the thermoluminescence dosimetry properties of copper-doped zinc lithium borate glass system

    International Nuclear Information System (INIS)

    Saidu, A.; Wagiran, H.; Saeed, M.A.; Alajerami, Y.S.M.; Kadir, A.B.A.

    2016-01-01

    The effect of sodium as a co-dopant on the thermoluminescence (TL) properties of copper-doped zinc lithium borate (ZLB: Cu) subjected to Co-60 gamma radiation is reported in this study. TL intensity is enhanced with the introduction of sodium in ZLB: Cu. The obtained glow curve is simple with a single peak. The annealing procedure and the best heating rate for the proposed thermoluminescent dosimeter (TLD) are established, and the phosphor is reusable. The TL response within the dose range of 0.5–1000 Gy is investigated. The results show that the thermal fading behaviour is improved significantly. - Highlights: • Dosimetry properties of an improved TL dosimeter. • The dosimeter is made of lithium borate, modified with ZnO, doped with CuO and co-doped with Na 2 O. • With addition of Na to Cu in the ZLB host, TL yield and sensitivity has significantly enhanced. • The fading behaviour has also been minimized significantly. • The new material is also characterized with the linear dose response, and good reproducibility behaviour.

  10. The International Reactor Dosimetry File (IRDF-85)

    International Nuclear Information System (INIS)

    Cullen, D.E.; McLaughlin, P.K.

    1985-04-01

    This document describes the contents of the second version of the International Reactor Dosimetry File (IRDF-85), distributed by the Nuclear Data Section of the International Atomic Energy Agency. This library superseded IRDF-82. (author)

  11. Light absorption properties of CDOM in the Changjiang (Yangtze) estuarine and coastal waters: An alternative approach for DOC estimation

    Science.gov (United States)

    Yu, Xiaolong; Shen, Fang; Liu, Yangyang

    2016-11-01

    Field measurements of CDOM absorption properties and DOC concentrations were collected in the Changjiang estuarine and coastal waters from 2011 to 2013. CDOM absorption coefficient at 355 nm (ag (355)) was found to be inversely correlated with salinity, with Pearson's coefficients r of -0.901 and -0.826 for summer and winter observations, respectively. Analysis results of the relationships between salinity and CDOM optical properties (i.e., absorption coefficient and spectral slope) suggested that terrigenous inputs dominated CDOM sources in the Changjiang estuary, but the proportion of terrigenous CDOM declined with increasing salinity. The level of CDOM in the Changjiang estuary was lower compared to some of the major estuaries in the world, which could be attributed to several controlling factors such as vegetation cover in the drainage basin, the origin of recharged streams and high sediment load in the Changjiang estuary. We further evaluated the relationships between CDOM and DOC and their mixing behavior among world's major estuaries. An empirical model was finally developed to estimate DOC concentration from ag (355) and spectral slope S275-295 using a non-linear regression. This empirical relationship was calibrated using the Cal dataset, and was validated with the Val dataset, resulting in an acceptable error with the R2 of 0.746, the RMSE of 20.99 μmol/L and the rMAD of 14.46%.

  12. Dosimetry; La dosimetrie

    Energy Technology Data Exchange (ETDEWEB)

    Le Couteulx, I.; Apretna, D.; Beaugerie, M.F. [Electricite de France (EDF), 75 - Paris (France)] [and others

    2003-07-01

    Eight articles treat the dosimetry. Two articles evaluate the radiation doses in specific cases, dosimetry of patients in radiodiagnosis, three articles are devoted to detectors (neutrons and x and gamma radiations) and a computer code to build up the dosimetry of an accident due to an external exposure. (N.C.)

  13. Analysis of aerosol absorption properties and transport over North Africa and the Middle East using AERONET data

    Directory of Open Access Journals (Sweden)

    A. Farahat

    2016-11-01

    Full Text Available In this paper particle categorization and absorption properties were discussed to understand transport mechanisms at different geographic locations and possible radiative impacts on climate. The long-term Aerosol Robotic Network (AERONET data set (1999–2015 is used to estimate aerosol optical depth (AOD, single scattering albedo (SSA, and the absorption Ångström exponent (αabs at eight locations in North Africa and the Middle East. Average variation in SSA is calculated at four wavelengths (440, 675, 870, and 1020 nm, and the relationship between aerosol absorption and physical properties is used to infer dominant aerosol types at different locations. It was found that seasonality and geographic location play a major role in identifying dominant aerosol types at each location. Analyzing aerosol characteristics among different sites using AERONET Version 2, Level 2.0 data retrievals and the Hybrid Single Particle Lagrangian Integrated Trajectory model (HYSPLIT backward trajectories shows possible aerosol particle transport among different locations indicating the importance of understanding transport mechanisms in identifying aerosol sources.

  14. Properties of the 4.45 eV optical absorption band in LiF:Mg, Ti

    International Nuclear Information System (INIS)

    Nail, I.; Oster, L.; Horowitz, Y. S.; Biderman, S.; Belaish, Y.

    2006-01-01

    The optical absorption (OA) and thermoluminescence (TL) of dosimetric LiF:Mg,Ti (TLD-100) as well as nominally pure LiF single crystal have been studied as a function of irradiation dose, thermal and optical bleaching in order to investigate the role of the 4.45 eV OA band in low temperature TL. Computerised deconvolution was used to resolve the absorption spectrum into individual gaussian bands and the TL glow curve into glow peaks. Although the 4.45 eV OA band shows thermal decay characteristics similar to the 4.0 eV band its dose filling constant and optical bleaching properties suggest that it cannot be associated with the TL of composite peaks 4 or 5. Its presence in optical grade single crystal LiF further suggests that it is an intrinsic defect or possibly associated with chance impurities other than Mg, Ti. (authors)

  15. Matching the laser wavelength to the absorption properties of matrices increases the ion yield in UV-MALDI mass spectrometry.

    Science.gov (United States)

    Wiegelmann, Marcel; Soltwisch, Jens; Jaskolla, Thorsten W; Dreisewerd, Klaus

    2013-09-01

    A high analytical sensitivity in ultraviolet matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) is only achieved if the laser wavelength corresponds to a high optical absorption of the matrix. Laser fluence and the physicochemical properties of the compounds, e.g., the proton affinity, also influence analytical sensitivity significantly. In combination, these parameters determine the amount of material ejected per laser pulse and the ion yield, i.e., the fraction of ionized biomolecules. Here, we recorded peptide ion signal intensities as a function of these parameters. Three cinnamic acid matrices were investigated: α-cyano-4-hydroxycinnamic acid, α-cyano-4-chlorocinnamic acid, and α-cyano-2,4-difluorocinnamic acid. In addition, 2,5-dihydroxybenzoic acid was used in comparison experiments. Ion signal intensities "per laser shot" and integrated ion signal intensities were acquired over 900 consecutive laser pulses applied on distinct positions on the dried-droplet sample preparations. With respect to laser wavelength, the two standard MALDI wavelengths of 337/355 nm were investigated. Also, 305 or 320 nm was selected to account for the blue-shifted absorption profiles of the halogenated derivatives. Maximal peptide ion intensities were obtained if the laser wavelength fell within the peak of the absorption profile of the compound and for fluences two to three times the corresponding ion detection threshold. The results indicate ways for improving the analytical sensitivity in MALDI-MS, and in particular for MALDI-MS imaging applications where a limited amount of material is available per irradiated pixel.

  16. [The photoluminescence and absorption properties of Co/AAO nano-array composites].

    Science.gov (United States)

    Li, Shou-Yi; Wang, Cheng-Wei; Li, Yan; Wang, Jian; Ma, Bao-Hong

    2008-03-01

    Ordered Co/AAO nano-array structures were fabricated by alternating current (AC) electrodeposition method within the cylindrical pores of anodic aluminum oxide (AAO) template prepared in oxalic acid electrolyte. The photoluminescence (PL) emission and photoabsorption of AAO templates and Co/AAO nano-array structures were investigated respectively. The results show that a marked photoluminescence band of AAO membranes occurs in the wavelength range of 350-550 nm and their PL peak position is at 395 nm. And with the increase in the deposition amount of Co nanoparticles, the PL intensity of Co/AAO nano-array structures decreases gradually, and their peak positions of the PL are invariable (395 nm). Meanwhile the absorption edges of Co/AAO show a larger redshift, and the largest shift from the near ultraviolet to the infrared exceeds 380 nm. The above phenomena caused by Co nano-particles in Co/AAO composite were analyzed.

  17. THE INTRINSIC FRACTIONS AND RADIO PROPERTIES OF LOW-IONIZATION BROAD ABSORPTION LINE QUASARS

    International Nuclear Information System (INIS)

    Dai Xinyu; Shankar, Francesco; Sivakoff, Gregory R.

    2012-01-01

    Low-ionization (Mg II, Fe II, and Fe III) broad absorption line quasars (LoBALs) probe a relatively obscured quasar population and could be at an early evolutionary stage for quasars. We study the intrinsic fractions of LoBALs using the Sloan Digital Sky Survey (SDSS), Two Micron All Sky Survey, and Faint Images of the Radio Sky at Twenty cm survey. We find that the LoBAL fractions of the near-infrared (NIR) and radio samples are approximately 5-7 times higher than those measured in the optical sample. This suggests that the fractions measured in the NIR and radio bands are closer to the intrinsic fractions of the populations, and that the optical fractions are significantly biased due to obscuration effects, similar to high-ionization broad absorption line quasars (HiBALs). Considering a population of obscured quasars that do not enter the SDSS, which could have a much higher LoBAL fraction, we expect that the intrinsic fraction of LoBALs could be even higher. We also find that the LoBAL fractions decrease with increasing radio luminosities, again, similarly to HiBALs. In addition, we find evidence for increasing fractions of LoBALs toward higher NIR luminosities, especially for FeLoBALs with a fraction of ∼18% at M K s < -31 mag. This population of NIR-luminous LoBALs may be at an early evolutionary stage of quasar evolution. To interpret the data, we use a luminosity-dependent model for LoBALs that yields significantly better fits than those from a pure geometric model.

  18. Thermal properties of carbon black aqueous nanofluids for solar absorption

    Directory of Open Access Journals (Sweden)

    Han Dongxiao

    2011-01-01

    Full Text Available Abstract In this article, carbon black nanofluids were prepared by dispersing the pretreated carbon black powder into distilled water. The size and morphology of the nanoparticles were explored. The photothermal properties, optical properties, rheological behaviors, and thermal conductivities of the nanofluids were also investigated. The results showed that the nanofluids of high-volume fraction had better photothermal properties. Both carbon black powder and nanofluids had good absorption in the whole wavelength ranging from 200 to 2,500 nm. The nanofluids exhibited a shear thinning behavior. The shear viscosity increased with the increasing volume fraction and decreased with the increasing temperature at the same shear rate. The thermal conductivity of carbon black nanofluids increased with the increase of volume fraction and temperature. Carbon black nanofluids had good absorption ability of solar energy and can effectively enhance the solar absorption efficiency.

  19. The dependence of C IV broad absorption line properties on accompanying Si IV and Al III absorption: relating quasar-wind ionization levels, kinematics, and column densities

    Energy Technology Data Exchange (ETDEWEB)

    Filiz Ak, N.; Brandt, W. N.; Schneider, D. P.; Trump, J. R. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Hall, P. B. [Department of Physics and Astronomy, York University, 4700 Keele Street, Toronto, Ontario M3J 1P3 (Canada); Anderson, S. F. [Astronomy Department, University of Washington, Seattle, WA 98195 (United States); Hamann, F. [Department of Astronomy, University of Florida, Gainesville, FL 32611-2055 (United States); Myers, Adam D. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Pâris, I. [Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago (Chile); Petitjean, P. [Institut d' Astrophysique de Paris, Universite Paris 6, F-75014 Paris (France); Ross, Nicholas P. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Shen, Yue [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); York, Don, E-mail: nfilizak@astro.psu.edu [Department of Astronomy and Astrophysics, The University of Chicago, Chicago, IL 60637 (United States)

    2014-08-20

    We consider how the profile and multi-year variability properties of a large sample of C IV Broad Absorption Line (BAL) troughs change when BALs from Si IV and/or Al III are present at corresponding velocities, indicating that the line of sight intercepts at least some lower ionization gas. We derive a number of observational results for C IV BALs separated according to the presence or absence of accompanying lower ionization transitions, including measurements of composite profile shapes, equivalent width (EW), characteristic velocities, composite variation profiles, and EW variability. We also measure the correlations between EW and fractional-EW variability for C IV, Si IV, and Al III. Our measurements reveal the basic correlated changes between ionization level, kinematics, and column density expected in accretion-disk wind models; e.g., lines of sight including lower ionization material generally show deeper and broader C IV troughs that have smaller minimum velocities and that are less variable. Many C IV BALs with no accompanying Si IV or Al III BALs may have only mild or no saturation.

  20. What's in the Wind? Determining the Properties of Outflowing Gas in Powerful Broad Absorption Line Quasars

    Science.gov (United States)

    Leighly, Karen

    2017-08-01

    A significant fraction of quasars exhibits blueshifted broadabsorption lines (BALs) in their rest-UV spectra, indicating powerfuloutflows emerging from the central engine. These outflows may removeangular momentum to enable black hole growth, enrich the intergalacticmedium with metals, and trigger quenching of star formation ingalaxies. Despite years of study, the physical conditions of theoutflowing gas are poorly understood. The handful of objects that havebeen subjected to detailed analysis are atypical and characterized byrelatively narrow lines where blending is unimportant. However,investigating more powerful BAL quasars will give us better insightinto the types of outflows much more likely to impact galaxyevolution.SimBAL is a novel spectral synthesis fitting method for BAL quasarsthat uses Bayesian model calibration to compare synthetic to observedspectra. With the model inputs of ionization parameter, columndensity, and covering fraction specified, the gas properties givingrise to the BAL features can be determined. We propose to applySimBAL to archival spectra of a sample of 14 luminous BAL quasars to characterize their bulk outflow properties as a function of velocityfor the first time. Our results will show the range of parameterstypical of powerful outflows, an essential step towards constrainingthe physics behind quasar winds and thus their impact on theirenvironments.

  1. Determination of the dosimetric properties of ZrO2: Cu and it use in the ultraviolet radiation dosimetry

    International Nuclear Information System (INIS)

    Molina P, D.; Olvera T, L.; Azorin N, J.; Barrera S, M.; Soto E, A.M.; Rivera M, T.

    2006-01-01

    In this work the experimental results of studying the thermoluminescent characteristics (TL) of the zirconium oxide doped with copper (ZrO 2 : Cu) exposed to ultraviolet light of wavelength in the interval of 200-400 nm are presented. The material in powder form was prepared using the sol-gel method. The dosimetric characteristics studied includes the emission curve TL (curved TL), the thermoluminescent response in function of the wavelength, the minimum dose detectable and the lineality of the response. The TL response of the ZrO 2 : Cu in function of the wavelength presents two maxima, in 260 and 290 nm, respectively. The TL curve of the ZrO 2 : Cu showed two peaks, in 120 and 170 C, respectively, being its similar form for all the studied wavelengths. The response in function of the spectral irradiance results to be lineal in the interval from 160 to 2300 mJ/cm 2 . The obtained results when studying the TL properties of ZrO 2 : Cu exposed to the ultraviolet radiation show that it gathers dosimetric characteristics prominent to be used as an ultraviolet radiation dosemeter. (Author)

  2. Absorption and emission properties of photonic crystals and metamaterials

    International Nuclear Information System (INIS)

    Peng, Lili

    2007-01-01

    We study the emission and absorption properties of photonic crystals and metamaterials using Comsol Multiphysics and Ansoft HFSS as simulation tools. We calculate the emission properties of metallic designs using drude model and the results illustrate that an appropriate termination of the surface of the metallic structure can significantly increase the absorption and therefore the thermal emissivity. We investigate the spontaneous emission rate modifications that occur for emitters inside two-dimensional photonic crystals and find the isotropic and directional emissions with respect to different frequencies as we have expected.

  3. Study on preparation and microwave absorption property of the core-nanoshell composite materials doped with La.

    Science.gov (United States)

    Wei, Liqiu; Che, Ruxin; Jiang, Yijun; Yu, Bing

    2013-12-01

    Microwave absorbing material plays a great role in electromagnetic pollution controlling, electromagnetic interference shielding and stealth technology, etc. The core-nanoshell composite materials doped with La were prepared by a solid-state reaction method, which is applied to the electromagnetic wave absorption. The core is magnetic fly-ash hollow cenosphere, and the shell is the nanosized ferrite doped with La. The thermal decomposition process of the sample was investigated by thermogravimetry and differential thermal analysis. The morphology and components of the composite materials were investigated by the X-ray diffraction analysis, the microstructure was observed by scanning electron microscope and transmission electron microscope. The results of vibrating sample magnetometer analysis indicated that the exchange-coupling interaction happens between ferrite of magnetic fly-ash hollow cenosphere and nanosized ferrite coating, which caused outstanding magnetic properties. The microwave absorbing property of the sample was measured by reflectivity far field radar cross section of radar microwave absorbing material with vector network analyzer. The results indicated that the exchange-coupling interaction enhanced magnetic loss of composite materials. Therefore, in the frequency of 5 GHz, the reflection coefficient can achieve -24 dB. It is better than single material and is consistent with requirements of the microwave absorbing material at the low-frequency absorption. Copyright © 2013 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  4. Thin film tritium dosimetry

    Science.gov (United States)

    Moran, Paul R.

    1976-01-01

    The present invention provides a method for tritium dosimetry. A dosimeter comprising a thin film of a material having relatively sensitive RITAC-RITAP dosimetry properties is exposed to radiation from tritium, and after the dosimeter has been removed from the source of the radiation, the low energy electron dose deposited in the thin film is determined by radiation-induced, thermally-activated polarization dosimetry techniques.

  5. Absorption properties of chromophoric dissolved organic matter (CDOM) in the East China Sea and the waters off eastern Taiwan

    Science.gov (United States)

    Zhou, Fengxia; Gao, Xuelu; Song, Jinming; Chen, Chen-Tung Arthur; Yuan, Huamao; Xing, Qianguo

    2018-05-01

    The absorption properties of chromophoric dissolved organic matter (CDOM) in the East China Sea (ECS) and the waters off eastern Taiwan (WET) were studied during May 2014. CDOM absorption coefficient (a280) and spectral slope (S275-295) revealed considerable spatial variations. In the ECS, the values of a280 and S275-295 presented a reverse distribution pattern. In the WET, a280 values were generally low while S275-295 values were generally high. Vertical distributions of a280 and S275-295 also varied in different regions. Terrestrial input, phytoplankton production, sediment release or photobleaching may be responsible for the dynamics of CDOM. Relationships among CDOM related parameters could partly support this conclusion. a280 were also used to trace different water masses and the result showed that the influence of Changjiang Diluted Water could reach the outer shelf of the northern ECS, and that the Kuroshio Current had a strong influence on the middle shelf of the southern ECS.

  6. A Comprehensive Review on the Properties of Coal Bottom Ash in Concrete as Sound Absorption Material

    Directory of Open Access Journals (Sweden)

    Ramzi Hannan Nurul Izzati Raihan

    2017-01-01

    Full Text Available The government is currently implementing policies to increase the usage of coal as fuel for electricity generation. At the same time, the dependency on gas will be reduced. In addition, coal power plants in Malaysia produce large amounts of industrial waste such as bottom ash which is collected in impoundment ponds (ash pond. However, millions of tons of coal ash (bottom ash waste are collected in ponds near power plant stations. Since bottom ash has been classified as hazardous material that threatens the health and safety of human life, an innovative and sustainable solution has been introduced to reuse or recycle industrial waste such as coal bottom ash in concrete mixtures to create a greener and more sustainable world. Bottom ash has the potential to be used as concrete material to replace fine aggregates, coarse aggregates or both. Hence, this paper provides an overview of previous research which used bottom ash as fine aggregate replacement in conventional concrete. The workability, compressive strength, flexural strength, and sound absorption of bottom ash in concrete are reviewed.

  7. Investigation of absorption spectra of Gafchromic EBT2 film's components and their impact on UVR dosimetry

    International Nuclear Information System (INIS)

    Aydarous, Abdulkadir

    2016-01-01

    The absorption spectra of the EBT2 film's components were investigated in conjunction with its use for UVA dosimetry. The polyester (topside) and adhesive layers of the EBT2 film have been gently removed. Gafchromic™ EBT2 films with and without the protected layers (polyester and adhesive) were exposed to UVR of 365 nm for different durations. Thereafter, the UV–visible spectra were measured using a UV–visible spectrophotometer (Model Spectro Dual Split Beam, UVS-2700). Films were digitized using a Nikon CanoScan 9000F Mark II flatbed scanner. The dosimetric characteristics including film's uniformity, reproducibility and post-irradiation development were investigated. The color development of EBT2 and new modified EBT2 (EBT2-M) films irradiated with UVA was relatively stable (less than 1%) immediately after exposure. Based on this study, the sensitivity of EBT2 to UVR with wavelength between ~350 nm and ~390 nm can significantly be enhanced if the adhesive layer (~25 µm) is removed. The polyester layer plays almost no part on absorbing UVR with wavelength between ~320 nm and ~390 nm. Furthermore, various sensitivities for the EBT2-M film has been established depending on the wavelength of analysis. - Highlights: • The absorption spectra of the EBT2 film's components were investigated. • The EBT2 sensitivity to UVR can be enhanced if the adhesive layer is removed. • The polyester layer plays almost no part on absorbing UVA radiation. • The color development of EBT2-M films was almost stable immediately after exposure.

  8. Radiation dosimetry activities in the Netherlands

    International Nuclear Information System (INIS)

    Broerse, J.J.; Mijnheer, B.J.

    1986-07-01

    The Netherlands Commission for Radiation Dosimetry (NCS) was officially established on 3 September 1982 with the aim of promoting the appropriate use of dosimetry of ionizing radiation both for scientific research and practical applications. The present report provides a compilation of the dosimetry acitivities and expertise available in the Netherlands, based on the replies to a questionnaire mailed under the auspices of the NCS and might suffer from some incompleteness in specific details. The addresses of the Dutch groups with the names of the scientists are given. Individual scientists, not connected with a scientific group, hospital or organization have not been included in this list. Also the names of commercial firms producing dosimetric systems have been omitted. (Auth.)

  9. Thermoluminescence properties of home-made CaSO4:Dy For Dosimetry Purposes

    International Nuclear Information System (INIS)

    Kamal, S.M.; Gerges, A.S.; Al-Said, M.A.

    2004-01-01

    Dysprosium doped Calcium Sulfate (CaSO 4 :Dy) had been first prepared by Yamashita in 1968 with method based on acid evaporation in an open system, which pose human health risks, corrosion and pollution to the environment due to sulfuric acid vapor. It has found increasing use in various applications in the field of radiation dosimetry due to their ease of preparation as compared to many other sensitive TL materials. Many researchers emphasized that the grain size and impurities influence the relative intensities of the broad glow peaks as well as overall sensitivities. In this paper, we introduce a new method of preparation for avoiding all of these disadvantages and improving the main TL materials properties, which required for dosimetric use. The main TL characteristics of home-made CaSO 4 :Dy .crystals with different concentrations are investigated alter the preparation and heat treatment conditions. The results indicated a linear response from 5μ .Gy up to 10 Gy with the highest sensitivity obtained at 0.25 mol % and optimum sensitivity at less than 75 jam grain sizes. Three peaks at 137 degree C, 222 degree C and 311 degree C were obtained. We conclude to use our home-made prepared CaSO 4 :Dy with 0.25 mol % concentration for gamma-ray dosimetry as more sensitive and cheaper than commercial phosphor (TLD-900). This will increase the routine and research work in the area of TL dosimetry

  10. Accurately Measuring the Color of the Ocean on Earth and from Space: Uncertainties Revisited and A Report from the Community-Led Spectral Absorption Workshop to Update and Revise the NASA Inherent Optical Properties Protocol

    Science.gov (United States)

    Neeley, Aimee Renee

    2014-01-01

    The color of the ocean (apparent optical properties or AOPs) is determined by the spectral scattering and absorption of light by its dissolved and particulate constituents.The absorption and scattering properties of the water column are the so-called inherent optical properties.

  11. SU-C-12A-04: Diagnostic Imaging Research Using Decedents as a Proxy for the Living: Are Radiation Dosimetry and Tissue Property Measurements Affected by Post-Mortem Changes?

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval, D; Heintz, P [Department of Radiology University of New Mexico School of Medicine, Albuquerque, NM (United States); Weber, W; Melo, D [Lovelace Respiratory Research Institute, Albuquerque, New Mexico (United States); Adolphi, N; Hatch, P [Radiology-Pathology Center for Forensic Imaging, University of New Mexico School of Medicine, Albuquerque, New Mexico (United States)

    2014-06-01

    Purpose: Radiation dose (RD) from diagnostic imaging is a growing public health concern. Implanting dosimeters is a more accurate way to assess organ dose, relative to commonly used mathematical estimations. However, performing accurate dosimetry using live subjects is hindered by patient motion and safety considerations, which limit the RD and placement of implanted dosimeters. Performing multiple scans on the same subject would be the ideal way to assess the impact of dose reduction on image quality; however, performing multiple non-standard-of-care scans on live subjects for dosimetry and image quality measurements is generally prohibited by IRB committees. Our objective is to assess whether RD and tissue property (TP) measurements in post-mortem (PM) subjects are sufficiently similar to those in live subjects to justify the use of deceased subjects in future dosimetry and image quality studies. Methods: 4 MOSFET radiation dosimeters were placed enterically in each subject (2 sedated Rhesus Macaques) to measure the RD at 4 levels (carina, lung, heart, and liver) during CT scanning. The CT protocol was performed ante-mortem (AM) and 2 and 3 hours PM. For TP analysis, additional scans were taken at 24 hours PM. To compare AM and PM TP, regions-of-interest were drawn on selected organs and the average CT density with standard deviation (in units of HU) were taken; additionally, visual comparisons of images were made at each PM interval. Results: No significant difference was observed in 8 of 9 measurements comparing AM and PM RD. Only one measurement (liver of the first subject) showed a significant difference (7% lower on PM measurement), possibly due to subject re-positioning. Initial TP visual and quantitative analyses show little to no change PM. Conclusion: Our results suggest that realistic radiation dosimetry and image quality measurements based on tissue properties can be performed reliably on recently deceased subjects.

  12. Updating the INDAC computer application of internal dosimetry

    International Nuclear Information System (INIS)

    Bravo Perez-Tinao, B.; Marchena Gonzalez, P.; Sollet Sanudo, E.; Serrano Calvo, E.

    2013-01-01

    The initial objective of this project is to expand the application INDAC currently used in internal dosimetry services of the Spanish nuclear power plants and Tecnatom for estimating the effective doses of internal dosimetry of workers in direct action. or in-vivo dosimetry. (Author)

  13. On the radiation dosimetry in space

    International Nuclear Information System (INIS)

    Doke, Tadayoshi

    2005-01-01

    The radiation dosimetry in space is considerably different from that on the earth surface, because, on the earth surface, the quality factor for radiation is roughly given for its energy but, in space, it is defined as a continuous function of LET. Thus, the contribution to the dose equivalent from heavy charged particles included in galactic cosmic rays is more than 50%, because of their high LET values. To evaluate such dose equivalent within an uncertainty of 30%, we must determine the true LET distribution. This paper describes the essence of such a new radiation dosimetry in space. (author)

  14. Reactor Dosimetry State of the Art 2008

    Science.gov (United States)

    Voorbraak, Wim; Debarberis, Luigi; D'Hondt, Pierre; Wagemans, Jan

    2009-08-01

    Oral session 1: Retrospective dosimetry. Retrospective dosimetry of VVER 440 reactor pressure vessel at the 3rd unit of Dukovany NPP / M. Marek ... [et al.]. Retrospective dosimetry study at the RPV of NPP Greifswald unit 1 / J. Konheiser ... [et al.]. Test of prototype detector for retrospective neutron dosimetry of reactor internals and vessel / K. Hayashi ... [et al.]. Neutron doses to the concrete vessel and tendons of a magnox reactor using retrospective dosimetry / D. A. Allen ... [et al.]. A retrospective dosimetry feasibility study for Atucha I / J. Wagemans ... [et al.]. Retrospective reactor dosimetry with zirconium alloy samples in a PWR / L. R. Greenwood and J. P. Foster -- Oral session 2: Experimental techniques. Characterizing the Time-dependent components of reactor n/y environments / P. J. Griffin, S. M. Luker and A. J. Suo-Anttila. Measurements of the recoil-ion response of silicon carbide detectors to fast neutrons / F. H. Ruddy, J. G. Seidel and F. Franceschini. Measurement of the neutron spectrum of the HB-4 cold source at the high flux isotope reactor at Oak Ridge National Laboratory / J. L. Robertson and E. B. Iverson. Feasibility of cavity ring-down laser spectroscopy for dose rate monitoring on nuclear reactor / H. Tomita ... [et al.]. Measuring transistor damage factors in a non-stable defect environment / D. B. King ... [et al.]. Neutron-detection based monitoring of void effects in boiling water reactors / J. Loberg ... [et al.] -- Poster session 1: Power reactor surveillance, retrospective dosimetry, benchmarks and inter-comparisons, adjustment methods, experimental techniques, transport calculations. Improved diagnostics for analysis of a reactor pulse radiation environment / S. M. Luker ... [et al.]. Simulation of the response of silicon carbide fast neutron detectors / F. Franceschini, F. H. Ruddy and B. Petrović. NSV A-3: a computer code for least-squares adjustment of neutron spectra and measured dosimeter responses / J. G

  15. Fundamentals of x-ray dosimetry

    International Nuclear Information System (INIS)

    Roesch, W.C.

    1976-01-01

    Fundamental information about x-ray dosimetry is presented. Definitions are given and expanded on for dose, absorbed dose including microdosimetry, radiation physics (properties of the radiation that are important to dosimetry), and dosimetry (how the properties are dealt with in determining dose). 5 figs, 12 refs

  16. and Three-Photon Absorption Properties of PRODAN based chemo ...

    Indian Academy of Sciences (India)

    Mehboob

    Solvent dependent One-, Two- and Three-Photon Absorption. Properties of PRODAN based chemo-sensors. Md. Mehboob Alam, Mausumi Chattopadhyaya. Department of Chemistry, University of Calcutta, 92 A.P.C. Road, Kolkata - 700009,. India. CONTENTS. 1) Optimized coordinates of all the systems in Gas phase and ...

  17. Deuterium absorption property of Al/Zr-V/Mo multifilms

    International Nuclear Information System (INIS)

    Wang Haifeng; Peng Shuming; Zhang Xiaohong; Long Xinggui; Yang Benfu

    2005-01-01

    Deuterium absorption property of Al/Zr-V/Mo multifilms was studied experimentally to explore the effect of Al film. There is only one desorption peak at 320 degree C for Al film, two desorption peaks at 220 degree C and 350 degree C for Zr-V film. When the average thickness of Al film is less than 0.6 μm, the desorption property of Al/Zr-V multifilms is just as Zr-V film, when it is more than 0.6 μm, just as Al film. Deuterium absorption by Al/Zr-V multifilms decreases as the thickness of Al film increases until 0.7 μm, then the deuterium absorption no longer changes significantly. The Al film of multifilms cracks on desorbing, so the absorption rate varies as Zr-V film when the thickness of Al film is less than 0.6 μ. When the thickness of Al film is more than 0.6 μm, the deuterium absorption rate of multifilm does not change with the thickness of Al film. (author)

  18. The United Kingdom's radiotherapy dosimetry audit network

    International Nuclear Information System (INIS)

    Thwaites, D.I.; Allahverdi, M.; Powley, S.K.; Nisbet, A.

    2003-01-01

    The first comprehensive national dosimetry intercomparison in the United Kingdom involving all UK radiotherapy centres was carried out in the late 1980s. Out of this a regular radiotherapy dosimetry audit network evolved in the early 1990s. The network is co-ordinated by the Institute of Physics and Engineering in Medicine and comprises eight co-operative regional groups. Audits are based on site visits using ionization chambers and epoxy resin water substitute phantoms. The basic audit methodology and phantom design follows that of the original national intercomparison exercise. However, most of the groups have evolved more complex methods, to extend the audit scope to include other parameters, other parts of the radiotherapy process and other treatment modalities. A number of the groups have developed phantoms to simulate various clinical treatment situations, enabling the sharing of phantoms and expertise between groups, but retaining a common base. Besides megavoltage external beam photon dosimetry, a number of the groups have also included the audit of kilovoltage X ray beams, electron beams and brachytherapy dosimetry. The National Physical Laboratory is involved in the network and carries out basic beam calibration audits to link the groups. The network is described and the methods and results are illustrated using the Scottish+ group as an example. (author)

  19. The work programme of EURADOS on internal and external dosimetry.

    Science.gov (United States)

    Rühm, W; Bottollier-Depois, J F; Gilvin, P; Harrison, R; Knežević, Ž; Lopez, M A; Tanner, R; Vargas, A; Woda, C

    2018-01-01

    Since the early 1980s, the European Radiation Dosimetry Group (EURADOS) has been maintaining a network of institutions interested in the dosimetry of ionising radiation. As of 2017, this network includes more than 70 institutions (research centres, dosimetry services, university institutes, etc.), and the EURADOS database lists more than 500 scientists who contribute to the EURADOS mission, which is to promote research and technical development in dosimetry and its implementation into practice, and to contribute to harmonisation of dosimetry in Europe and its conformance with international practices. The EURADOS working programme is organised into eight working groups dealing with environmental, computational, internal, and retrospective dosimetry; dosimetry in medical imaging; dosimetry in radiotherapy; dosimetry in high-energy radiation fields; and harmonisation of individual monitoring. Results are published as freely available EURADOS reports and in the peer-reviewed scientific literature. Moreover, EURADOS organises winter schools and training courses on various aspects relevant for radiation dosimetry, and formulates the strategic research needs in dosimetry important for Europe. This paper gives an overview on the most important EURADOS activities. More details can be found at www.eurados.org .

  20. Excellent improvement in the static and dynamic magnetic properties of carbon coated iron nanoparticles for microwave absorption

    Energy Technology Data Exchange (ETDEWEB)

    Khani, Omid, E-mail: omidkhani@mut-es.ac.ir; Shoushtari, Morteza Zargar; Farbod, Mansoor

    2015-11-15

    Carbon coated iron nanoparticles were synthesized, using a simple arc-discharge method. The morphology and the internal structure of the core/shell nanoparticles were studied, using field emission scanning electron microscopy and transmission electron microscopy. X-ray diffraction analysis showed that both magnetic α-Fe and nonmagnetic γ-Fe phases existed in the as-prepared particles. In order to improve the static and dynamic magnetic properties of the core/shell nanoparticles, the produced nanocapsules were annealed in argon atmosphere at two different temperatures. Hysteresis loops revealed that the value of the saturation magnetization (M{sub S}) increased more than 4.1 times of its original value by annealing and this led to 70% increase in the imaginary part of the permeability. Phase analysis showed that heat treatment eliminated the nonmagnetic γ-Fe phase completely. The reflection loss plots were studied for composite layers containing 20 vol% of the annealed and not annealed nanocapsules. One of the absorber layers which contained annealed nanocapsules showed at least −10 dB loss in the whole G, C, X and Ku frequency bands and the optimal absorption exceeded −37 dB at 5.8 GHz for the as-prepared sample with a thickness of 3.2 mm. The results revealed that the magnetic properties of the arc-made Fe/C core/shell nanoparticle can be improved significantly by annealing in argon.

  1. The dust, nebular emission, and dependence on QSO radio properties of the associated Mg II absorption line systems

    International Nuclear Information System (INIS)

    Khare, Pushpa; Daniel, Vanden Berk; Rahmani, Hadi; York, Donald G.

    2014-01-01

    We studied dust reddening and [O II] emission in 1730 Mg II associated absorption systems (AAS; relative velocity with respect to QSOs, ≤3000 km s –1 ; in units of velocity of light, β, ≤0.01) with 0.4 ≤z abs ≤ 2 in the Sloan Digital Sky Survey DR7, focusing on their dependence on the radio and other QSO properties. We used control samples, several with matching radio properties, to show that (1) AAS in radio-detected (RD) QSOs cause 2.6 ± 0.2 times higher dust extinction than those in radio-undetected (RUD) ones, which in turn cause 2.9 ± 0.7 times the dust extinction in the intervening systems; (2) AAS in core-dominated QSOs cause 2.0 ± 0.1 times higher dust extinction than those in lobe-dominated QSOs; (3) the occurrence of AAS is 2.1 ± 0.2 times more likely in RD QSOs than in RUD QSOs and 1.8 ± 0.1 time more likely in QSOs having black holes with masses larger than 1.23 × 10 9 M ☉ than in those with lower-mass black holes; and (4) there is excess flux in [O II]λ3727 emission in the composite spectra of the AAS samples compared with those of the control samples, which is at the emission redshift. The presence of AAS enhances the O II emission from the active galactic nucleus and/or the host galaxy. This excess is similar for both RD and RUD samples and is 2.5 ± 0.4 times higher in lobe-dominated samples than in core-dominated samples. The excess depends on the black hole mass and Eddington ratio. All these point to the intrinsic nature of the AAS except for the systems with z abs > z em , which could be infalling galaxies.

  2. Photophysiological and light absorption properties of phytoplankton communities in the river-dominated margin of the northern Gulf of Mexico

    Science.gov (United States)

    Chakraborty, Sumit; Lohrenz, Steven E.; Gundersen, Kjell

    2017-06-01

    Spatial and temporal variability in photophysiological properties of phytoplankton were examined in relationship to phytoplankton community composition in the river-dominated continental margin of the northern Gulf of Mexico (NGOM). Observations made during five research cruises in the NGOM included phytoplankton photosynthetic and optical properties and associated environmental conditions and phytoplankton community structure. Distinct patterns of spatial and temporal variability in photophysiological parameters were found for waters dominated by different phytoplankton groups. Photophysiological properties for locations associated with dominance by a particular group of phytoplankton showed evidence of photoacclimation as reflected by differences in light absorption and pigment characteristics in relationship to different light environments. The maximum rate of photosynthesis normalized to chlorophyll (PmaxB) was significantly higher for communities dominated (>60% biomass) by cyanobacteria + prochlorophyte (cyano + prochl). The initial slope of the photosynthesis-irradiance (P-E) curve normalized to chlorophyll (αB) was not clearly related to phytoplankton community structure and no significant differences were found in PmaxB and αB between different geographic regions. In contrast, maximum quantum yield of carbon fixation in photosynthesis (Φcmax) differed significantly between regions and was higher for diatom-dominated communities. Multiple linear regression models, specific for the different phytoplankton communities, using a combination of environmental and bio-optical proxies as predictor variables showed considerable promise for estimation of the photophysiological parameters on a regional scale. Such an approach may be utilized to develop size class-specific or phytoplankton group-specific primary productivity models for the NGOM.Plain Language SummaryThis study examined the relationships between phytoplankton community composition and associated

  3. A synthesis of light absorption properties of the Arctic Ocean: application to semianalytical estimates of dissolved organic carbon concentrations from space

    Science.gov (United States)

    Matsuoka, A.; Babin, M.; Doxaran, D.; Hooker, S. B.; Mitchell, B. G.; Bélanger, S.; Bricaud, A.

    2014-06-01

    In addition to scattering coefficients, the light absorption coefficients of particulate and dissolved materials are the main factors determining the light propagation of the visible part of the spectrum and are, thus, important for developing ocean color algorithms. While these absorption properties have recently been documented by a few studies for the Arctic Ocean (e.g., Matsuoka et al., 2007, 2011; Ben Mustapha et al., 2012), the data sets used in the literature were sparse and individually insufficient to draw a general view of the basin-wide spatial and temporal variations in absorption. To achieve such a task, we built a large absorption database of the Arctic Ocean by pooling the majority of published data sets and merging new data sets. Our results show that the total nonwater absorption coefficients measured in the eastern Arctic Ocean (EAO; Siberian side) are significantly higher than in the western Arctic Ocean (WAO; North American side). This higher absorption is explained by higher concentration of colored dissolved organic matter (CDOM) in watersheds on the Siberian side, which contains a large amount of dissolved organic carbon (DOC) compared to waters off North America. In contrast, the relationship between the phytoplankton absorption (aϕ(λ)) and chlorophyll a (chl a) concentration in the EAO was not significantly different from that in the WAO. Because our semianalytical CDOM absorption algorithm is based on chl a-specific aϕ(λ) values (Matsuoka et al., 2013), this result indirectly suggests that CDOM absorption can be appropriately derived not only for the WAO but also for the EAO using ocean color data. Based on statistics, derived CDOM absorption values were reasonable compared to in situ measurements. By combining this algorithm with empirical DOC versus CDOM relationships, a semianalytical algorithm for estimating DOC concentrations for river-influenced coastal waters of the Arctic Ocean is presented and applied to satellite

  4. A synthesis of light absorption properties of the Pan-Arctic Ocean: application to semi-analytical estimates of dissolved organic carbon concentrations from space

    Science.gov (United States)

    Matsuoka, A.; Babin, M.; Doxaran, D.; Hooker, S. B.; Mitchell, B. G.; Bélanger, S.; Bricaud, A.

    2013-11-01

    The light absorption coefficients of particulate and dissolved materials are the main factors determining the light propagation of the visible part of the spectrum and are, thus, important for developing ocean color algorithms. While these absorption properties have recently been documented by a few studies for the Arctic Ocean (e.g., Matsuoka et al., 2007, 2011; Ben Mustapha et al., 2012), the datasets used in the literature were sparse and individually insufficient to draw a general view of the basin-wide spatial and temporal variations in absorption. To achieve such a task, we built a large absorption database at the pan-Arctic scale by pooling the majority of published datasets and merging new datasets. Our results showed that the total non-water absorption coefficients measured in the Eastern Arctic Ocean (EAO; Siberian side) are significantly higher than in the Western Arctic Ocean (WAO; North American side). This higher absorption is explained by higher concentration of colored dissolved organic matter (CDOM) in watersheds on the Siberian side, which contains a large amount of dissolved organic carbon (DOC) compared to waters off North America. In contrast, the relationship between the phytoplankton absorption (aφ(λ)) and chlorophyll a (chl a) concentration in the EAO was not significantly different from that in the WAO. Because our semi-analytical CDOM absorption algorithm is based on chl a-specific aφ(λ) values (Matsuoka et al., 2013), this result indirectly suggests that CDOM absorption can be appropriately derived not only for the WAO but also for the EAO using ocean color data. Derived CDOM absorption values were reasonable compared to in situ measurements. By combining this algorithm with empirical DOC vs. CDOM relationships, a semi-analytical algorithm for estimating DOC concentrations for coastal waters at the Pan-Arctic scale is presented and applied to satellite ocean color data.

  5. A Synthesis of Light Absorption Properties of the Arctic Ocean: Application to Semi-analytical Estimates of Dissolved Organic Carbon Concentrations from Space

    Science.gov (United States)

    Matsuoka, A.; Babin, M.; Doxaran, D.; Hooker, S. B.; Mitchell, B. G.; Belanger, S.; Bricaud, A.

    2014-01-01

    The light absorption coefficients of particulate and dissolved materials are the main factors determining the light propagation of the visible part of the spectrum and are, thus, important for developing ocean color algorithms. While these absorption properties have recently been documented by a few studies for the Arctic Ocean [e.g., Matsuoka et al., 2007, 2011; Ben Mustapha et al., 2012], the datasets used in the literature were sparse and individually insufficient to draw a general view of the basin-wide spatial and temporal variations in absorption. To achieve such a task, we built a large absorption database at the pan-Arctic scale by pooling the majority of published datasets and merging new datasets. Our results showed that the total non-water absorption coefficients measured in the Eastern Arctic Ocean (EAO; Siberian side) are significantly higher 74 than in the Western Arctic Ocean (WAO; North American side). This higher absorption is explained 75 by higher concentration of colored dissolved organic matter (CDOM) in watersheds on the Siberian 76 side, which contains a large amount of dissolved organic carbon (DOC) compared to waters off 77 North America. In contrast, the relationship between the phytoplankton absorption (a()) and chlorophyll a (chl a) concentration in the EAO was not significantly different from that in the WAO. Because our semi-analytical CDOM absorption algorithm is based on chl a-specific a() values [Matsuoka et al., 2013], this result indirectly suggests that CDOM absorption can be appropriately erived not only for the WAO but also for the EAO using ocean color data. Derived CDOM absorption values were reasonable compared to in situ measurements. By combining this algorithm with empirical DOC versus CDOM relationships, a semi-analytical algorithm for estimating DOC concentrations for coastal waters at the Pan-Arctic scale is presented and applied to satellite ocean color data.

  6. The synergistic effects of carbon coating and micropore structure on the microwave absorption properties of Co/CoO nanoparticles.

    Science.gov (United States)

    Xie, Xiubo; Pang, Yu; Kikuchi, Hiroaki; Liu, Tong

    2016-11-09

    25 nm carbon-coated microporous Co/CoO nanoparticles (NPs) were synthesized by integrating chemical de-alloying and chemical vapor deposition (CVD) methods. The NPs possess micropores of 0.8-1.5 nm and display a homogeneous carbon shell of about 4 nm in thickness with a low graphitization degree. The saturation magnetization (M S ) and coercivity (H C ) of the NPs were 70.3 emu g -1 and 398.4 Oe, respectively. The microporous Co/CoO/C NPs exhibited enhanced microwave absorption performance with a minimum reflection coefficient (RC) of -78.4 dB and a wide absorption bandwidth of 8.1 GHz (RC ≤ -10 dB), larger than those of the nonporous counterparts of -68.3 dB and 5.8 GHz. The minimum RC values of the microporous Co/CoO/C NPs at different thicknesses were much smaller than the nonporous counterparts. The high microwave absorption mechanism of the microporous Co/CoO/C nanocomposite can be interpreted in terms of the interfacial polarization relaxation of the core/shell and micropore structures, the effective permittivity modification of the air in the micropores and the polarization relaxation of the defects in the low-graphitization carbon shell and the porous Co NPs. Our study demonstrates that the microporous Co/CoO/C nanocomposite is an efficient microwave absorber with high absorption intensity and wide absorption bandwidth.

  7. Application of spectroscopic techniques in the radiation dosimetry of glasses: An update

    International Nuclear Information System (INIS)

    Natarajan, V

    2009-01-01

    The colorimetry and thermoluminescence properties of gamma irradiated glass were reported in as early as 1920. The utility of radio-photoluminescence (RPL) of silver activated metaphosphate glass for monitoring high doses of accidental and routine gamma radiation was reported in the 1960s. Since then considerable amount of research work has been carried out to study the thermoluminescence (TL), optical absorption (OA), electron paramagnetic resonance (EPR) and optically stimulated luminescence (OSL) of different commercially available glasses for high as well as low dose applications. A brief review of the progress made in the spectroscopic studies of glasses during the past few decades and the application of glasses for radiation dosimetry has been given in this paper.

  8. Application of spectroscopic techniques in the radiation dosimetry of glasses: An update

    Energy Technology Data Exchange (ETDEWEB)

    Natarajan, V, E-mail: vnatra@yahoo.co.in [Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 40085 (India)

    2009-07-15

    The colorimetry and thermoluminescence properties of gamma irradiated glass were reported in as early as 1920. The utility of radio-photoluminescence (RPL) of silver activated metaphosphate glass for monitoring high doses of accidental and routine gamma radiation was reported in the 1960s. Since then considerable amount of research work has been carried out to study the thermoluminescence (TL), optical absorption (OA), electron paramagnetic resonance (EPR) and optically stimulated luminescence (OSL) of different commercially available glasses for high as well as low dose applications. A brief review of the progress made in the spectroscopic studies of glasses during the past few decades and the application of glasses for radiation dosimetry has been given in this paper.

  9. A study on the retrospective dosimetry using electron paramagnetic resonance spectroscopy of tooth enamel

    International Nuclear Information System (INIS)

    Hong, Dae Seok

    2004-02-01

    Retrospective dosimetry is a process that is a part of dose reconstruction for estimation of exposed dose occurred years before the estimation. Dose reconstruction may be required in a variety of situations such as acute accidental exposure, suspected chronic overexposure and reassessment of occupational exposure. The techniques for retrospective can be classified as biological method and physical method. As a distinct physical technique for dose reconstruction, EPR (Electron Paramagnetic Resonance) or ESR (Electron Spin Resonance) dosimetry has been widely used. In EPR dosimetry, electrons generated by the interaction of material with radiation and trapped in lattice are measured by microwave absorption spectroscopy. Among the materials used for EPR dosimetry, tooth enamel has a high sensitivity for ionising radiation and since the tooth follows the carrier in all situations, it can act as a lifetime-dosimeter. And it is considered as one of the important biological samples. In many countries, there have been a lot of studies and practical applications on EPR dosimetry with tooth enamel. This technique has been applied for A-bomb survivors, Techa riverside population, Chernobyl cleanup workers and so on. Also there were two times of international comparison of the results of EPR dosimetry with tooth enamel in 1996 and 2000 respectively. But the experts have yet to reach a consensus on the best method. So, a lot of methods have been used for the separation of enamel from teeth and this may influence the dose evaluation. With the factors affecting EPR spectrum, this can effect on the results of dose reconstructed. In this study, factors affecting the EPR spectrum of tooth are experimented first. Anisotropy of radiation induced CO 2 - radical is negligible at low doses, but it become important at high doses. It can induce errors in dose estimation up to 40% at dose range of 5Gy. So, crushing process is essential in dose estimation. But, since sample grinding can

  10. Microwave absorption properties of gold nanoparticle doped polymers

    DEFF Research Database (Denmark)

    Jiang, Chenhui; Ouattara, Lassana; Ingrosso, Chiara

    2011-01-01

    This paper presents a method for characterizing microwave absorption properties of gold nanoparticle doped polymers. The method is based on on-wafer measurements at the frequencies from 0.5GHz to 20GHz. The on-wafer measurement method makes it possible to characterize electromagnetic (EM) property...... of small volume samples. The epoxy based SU8 polymer and SU8 doped with gold nanoparticles are chosen as the samples under test. Two types of microwave test devices are designed for exciting the samples through electrical coupling and magnetic coupling, respectively. Measurement results demonstrate...... that the nanocomposites absorb a certain amount of microwave energy due to gold nanoparticles. Higher nanoparticle concentration results in more significant absorption effect....

  11. Microwave absorption properties of gold nanoparticle doped polymers

    Science.gov (United States)

    Jiang, C.; Ouattara, L.; Ingrosso, C.; Curri, M. L.; Krozer, V.; Boisen, A.; Jakobsen, M. H.; Johansen, T. K.

    2011-03-01

    This paper presents a method for characterizing microwave absorption properties of gold nanoparticle doped polymers. The method is based on on-wafer measurements at the frequencies from 0.5 GHz to 20 GHz. The on-wafer measurement method makes it possible to characterize electromagnetic (EM) property of small volume samples. The epoxy based SU8 polymer and SU8 doped with gold nanoparticles are chosen as the samples under test. Two types of microwave test devices are designed for exciting the samples through electrical coupling and magnetic coupling, respectively. Measurement results demonstrate that the nanocomposites absorb a certain amount of microwave energy due to gold nanoparticles. Higher nanoparticle concentration results in more significant absorption effect.

  12. Synthesis and microwave absorption properties of PPy/Co nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Juhua, E-mail: luojuhua@163.com [School of Materials Engineering, Yancheng Institute of Technology, Yancheng 224051 (China); Gao, Duoduo [School of Material Science and Engineering, Changzhou University, Changzhou 213164 (China)

    2014-11-15

    Polypyrrole (PPy)/cobalt (Co) nanocomposites were successfully prepared by an in-situ polymerization of pyrrole in the presence of synthesized Co nanoparticles. Characterization of the product was accomplished by XRD, TEM, FT-IR, VSM, and vector network analyzer techniques. XRD analysis revealed that characteristic diffraction peaks of polypyrrole and Co appeared at the same time in nanocomposites. FT-IR analysis indicated a successful conjugation of Co particles with polypyrrole. TEM confirmed the formation of a core-shell structure with a wide particle size distribution. Magnetization measurements showed that polypyrrole coating decreased the saturation magnetization of Co significantly. With the increase of the matching thickness, the absorption peak varied towards low frequency direction. When the matching thickness was 3.0 mm, the value of the maximum reflection loss (RL) was −20.0 dB at 13.8 GHz with the 7.2 GHz bandwidth. - Highlights: • The influence of PPy on the structure of Co is discussed. • The influence of PPy on the magnetic properties of Co is discussed. • The influence of PPy on the absorption property of Co is discussed. • PPy/Co possessed the excellent absorption property.

  13. Light absorption properties of colored dissolved organic matter (CDOM) in adjacent waters of the Changjiang Estuary during a flood season: implication for DOC estimation

    Science.gov (United States)

    Liu, Yangyang; Shen, Fang; Li, Xiuzhen

    2014-11-01

    Light absorption properties of colored dissolved organic matter (CDOM) in adjacent waters of the Changjiang Estuary were investigated during the summer of 2013. CDOM absorption showed a substantial portion of the total absorption and clearly dominant among most investigation stations. It generally decreased from the northwest to the southeast, which controlled by physical mixing of fresh water and seawater as was indicated by a conservative behaviour of CDOM. CDOM absorption sharply increased during phytoplankton blooms. Similarly, dissolved organic carbon (DOC) also peaked during blooms period. However, DOC exhibited a more complex behavior relative to a simple conservative mixing, possibly attributed to multiple origins of DOC. CDOM absorption and DOC co-varied to some degree, implying a potential way of DOC estimation from CDOM absorption. However, more detailed information such as CDOM and DOC composition and more validation data were required to obtain a stable CDOM - DOC pattern. Lastly, empirical algorithms with limited data were developed to retrieve CDOM absorption. Further validation of the algorithms were needed when they were to be commonly applied.

  14. The Effect of wheat straw particle size on the mechanical and water absorption properties of wheat straw/low density polyethylene biocomposites for packaging applications

    Directory of Open Access Journals (Sweden)

    Behjat Tajeddin

    2017-08-01

    Full Text Available Natural composites with biodegradability properties can be used as a renewable alternative to replacing conventional plastics. Thus, to reduce the plastics applications in the packaging industry, biocomposites content of wheat straw (with 40, 100, 140 mesh as a natural biodegradable composite and low density polyethylene (LDPE as a common synthetic polymer in the packaging industry were prepared and characterized by the mechanical and water absorption properties. Polyethylene-graft-maleic anhydride was used as a compatibilizer material. Morphology of wheat straw flour was studied by optical microscope to obtain the aspect ratio (L/D. The tensile and flexural tests were applied for determining mechanical properties and scanning electron microscope (SEM was used for particles distribution and sample structures. The water absorption of the samples was calculated by weight difference. The results indicated that the particle size of wheat straw four and the L/D amount are Significantly affected on the tensile strength and water absorption of the samples. However, the effect of wheat sraw particle size on the flexural strength was not significant. Overall conclusions show that by increasing the particle size of the filler (wheat straw, can prepare the biocomposite with better tensile strength and less water absorption compared with smaller particle size.

  15. A CHANDRA SURVEY OF THE X-RAY PROPERTIES OF BROAD ABSORPTION LINE RADIO-LOUD QUASARS

    International Nuclear Information System (INIS)

    Miller, B. P.; Brandt, W. N.; Garmire, G. P.; Gibson, R. R.; Shemmer, O.

    2009-01-01

    This work presents the results of a Chandra study of 21 broad absorption line (BAL) radio-loud quasars (RLQs). We conducted a Chandra snapshot survey of 12 bright BAL RLQs selected from Sloan Digital Sky Survey Data/Faint Images of the Radio Sky data and possessing a wide range of radio and C IV absorption properties. Optical spectra were obtained nearly contemporaneously with the Hobby-Eberly Telescope; no strong flux or BAL variability was seen between epochs. In addition to the snapshot targets, we include in our sample nine additional BAL RLQs possessing archival Chandra coverage. We compare the properties of (predominantly high-ionization) BAL RLQs to those of non-BAL RLQs as well as to BAL radio-quiet quasars (RQQs) and non-BAL RQQs for context. All 12 snapshots and 8/9 archival BAL RLQs are detected, with observed X-ray luminosities less than those of non-BAL RLQs having comparable optical/UV luminosities by typical factors of 4.1-8.5. (BAL RLQs are also X-ray weak by typical factors of 2.0-4.5 relative to non-BAL RLQs having both comparable optical/UV and radio luminosities.) However, BAL RLQs are not as X-ray weak relative to non-BAL RLQs as are BAL RQQs relative to non-BAL RQQs. While some BAL RLQs have harder X-ray spectra than typical non-BAL RLQs, some have hardness ratios consistent with those of non-BAL RLQs, and there does not appear to be a correlation between X-ray weakness and spectral hardness, in contrast to the situation for BAL RQQs. RLQs are expected to have X-ray continuum contributions from both accretion-disk corona and small-scale jet emission. While the entire X-ray continuum in BAL RLQs cannot be obscured to the same degree as in BAL RQQs, we calculate that the jet is likely partially covered in many BAL RLQs. We comment briefly on implications for geometries and source ages in BAL RLQs.

  16. Study on hydrogen absorption/desorption properties of uranium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hiroshi; Yamaguchi, Kenji; Yamawaki, Michio [Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.

    1996-10-01

    Hydrogen absorption/desorption properties of two U-Mn intermetallic compounds, U{sub 6}Mn and UMn{sub 2}, were investigated. U{sub 6}Mn absorbed hydrogen and the hydrogen desorption pressure of U{sub 6}Mn obtained from this experiment was higher than that of U, which was considered to be the effect of alloying, whereas UMn{sub 2} was not observed to absorb hydrogen up to 50 atm at room temperature. (author)

  17. Individual neutron dosimetry

    International Nuclear Information System (INIS)

    Mauricio, C.L.P.

    1987-01-01

    The most important concepts and development in individual neutron dosimetry are presented, especially the dosimetric properties of the albedo technique. The main problem in albedo dosimetry is to calibrate the dosemeter in the environs of each neutron source. Some of the most used calibration techniques are discussed. The IRD albedo dosemeter used in the routine neutron individual monitoring is described in detail. Its dosimetric properties and calibration methods are discussed. (Author) [pt

  18. Dosimetry requirements derived from the sterilization standards

    DEFF Research Database (Denmark)

    Miller, A.

    1998-01-01

    The main standards for radiation sterilization, ISO 11137 and EN 552, rest the documentation for the properly executed sterilization process on dosimetry. Both standards describe general requirements to the dosimetry system: The dose measurements must be traceable to national standards...... and documented uncertainty limits of the dose measurements can be used to specify process control limits. This is also useful, for example, when dose setting experiments are carried out according to the methods described in ISO 11137, where product samples shall be irradiated within narrow limits......., the uncertainty of the dose measurement and the environmental influences must be known. This paper discusses how to obtain and maintain traceability and how to document measurement uncertainty. The implications of these requirements in the process control of radiation sterilization are further discussed. Known...

  19. Temperature dependence of the electromagnetic properties and microwave absorption of carbonyl iron particles/silicone resin composites

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yingying; Zhou, Wancheng; Qing, Yuchang; Luo, Fa; Zhu, Dongmei

    2015-01-15

    Microwave absorbing composites with thin thickness and wideband absorption were successfully prepared by a spraying method using carbonyl iron particles (CIPs) as absorbers and silicone resin as the matrix. The value of reflection loss (RL) below −5 dB can be obtained in the frequency range of 5.76–18 GHz for the composite with 0.8 mm thickness. The temperature dependence of electromagnetic properties and RL of the composites were investigated. The RL of the composite showed a slight variation when the temperature reached up to 200 °C while decreased at 300 °C. The room temperature RL of the composite did not display significant difference before and after the heat treatment at 300 °C for 10 h; the mechanism was also discussed. - Highlights: • Carbonyl iron particles/silicone resin composites are prepared by a spraying method. • Reflection loss values exceed −5 dB at 5.76–18 GHz for an absorber of 0.8 mm thickness. • The variation of reflection loss was studied from room temperature to 300 °C.

  20. The dust, nebular emission, and dependence on QSO radio properties of the associated Mg II absorption line systems

    Energy Technology Data Exchange (ETDEWEB)

    Khare, Pushpa [CSIR Emeritus Scientist, IUCAA, Ganeshkhind, Pune 411007 (India); Daniel, Vanden Berk [Physics Department, St. Vincent College, Latrobe, PA 15650 (United States); Rahmani, Hadi [School of Astronomy, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); York, Donald G., E-mail: pushpakhare@gmail.com [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States)

    2014-10-10

    We studied dust reddening and [O II] emission in 1730 Mg II associated absorption systems (AAS; relative velocity with respect to QSOs, ≤3000 km s{sup –1}; in units of velocity of light, β, ≤0.01) with 0.4 ≤z {sub abs} ≤ 2 in the Sloan Digital Sky Survey DR7, focusing on their dependence on the radio and other QSO properties. We used control samples, several with matching radio properties, to show that (1) AAS in radio-detected (RD) QSOs cause 2.6 ± 0.2 times higher dust extinction than those in radio-undetected (RUD) ones, which in turn cause 2.9 ± 0.7 times the dust extinction in the intervening systems; (2) AAS in core-dominated QSOs cause 2.0 ± 0.1 times higher dust extinction than those in lobe-dominated QSOs; (3) the occurrence of AAS is 2.1 ± 0.2 times more likely in RD QSOs than in RUD QSOs and 1.8 ± 0.1 time more likely in QSOs having black holes with masses larger than 1.23 × 10{sup 9} M {sub ☉} than in those with lower-mass black holes; and (4) there is excess flux in [O II]λ3727 emission in the composite spectra of the AAS samples compared with those of the control samples, which is at the emission redshift. The presence of AAS enhances the O II emission from the active galactic nucleus and/or the host galaxy. This excess is similar for both RD and RUD samples and is 2.5 ± 0.4 times higher in lobe-dominated samples than in core-dominated samples. The excess depends on the black hole mass and Eddington ratio. All these point to the intrinsic nature of the AAS except for the systems with z {sub abs} > z {sub em}, which could be infalling galaxies.

  1. Investigation of structural and hydrogen absorption properties in the LaNi5-xPtx-H2 system

    International Nuclear Information System (INIS)

    Joubert, J.-M.; Charton, J.; Percheron-Guegan, A.

    2003-01-01

    The substitution of nickel by platinum in the binary LaNi 5 compound (CaCu 5 structure type, a=5.019(1) A, c=3.981(1) A, space group P6/mmm) and its effect on the hydrogenation properties was studied. The phase LaNi 5-x Pt x has a homogeneity domain ranging from x=0 to 5. For x 3. Contrary to what is observed in other systems, the hydrogen absorption plateau pressure was found to increase as a function of the cell volume. Powder neutron diffraction experiments were conducted for two deuterated compounds with x=0.25 and 0.75. Deuterium partial ordering occurs in the case of x=0.25 leading to a symmetry decrease to the space group P6mm (LaNi 4.75 Pt 0.25 D 5.23 , a=4.225(1) A, c=5.357(1) A, Z=1, R Bragg =3.3%). For x=0.75, an orthorhombic superstructure based on the CaCu 5 -type lattice was found (LaNi 4.25 Pt 0.75 D 2.61 , a orth =√3a hex =9.089(1) A, b orth =b hex =5.272(1) A, c orth =2c hex =8.145(1) A, Z=4, SG Ibam, R Bragg =6.1%)

  2. Radiation, cancer risk, and the new dosimetry

    International Nuclear Information System (INIS)

    Mole, R.H.

    1987-01-01

    This letter discusses revision of risk estimates in the light of the new dosimetry (DS86) and concludes that direct observation is more to be relied on than the extrapolation from A-bomb survivors' experience. X-ray treatment for ankylosing spondylitis, cervical cancer data, and figures observed from 50,000 workers occupationally exposed to radiation are used as examples. (U.K.)

  3. Scattering and Absorption Properties of Biomaterials for Dental Restorative Applications

    Science.gov (United States)

    Fernandez-Oliveras, A.; Rubiño, M.; Pérez, M. M.

    2013-08-01

    The physical understanding of the optical properties of dental biomaterials is mandatory for their final success in restorative applications.Light propagation in biological media is characterized by the absorption coefficient, the scattering coefficient, the scattering phase function,the refractive index, and the surface conditions (roughness). We have employed the inverse adding-doubling (IAD) method to combine transmittance and reflectance measurements performed using an integrating-sphere setup with the results of the previous scattering-anisotropygoniometric measurements. This has led to the determination of the absorption and the scattering coefficients. The aim was to optically characterize two different dental-resin composites (nanocomposite and hybrid) and one type of zirconia ceramic, and comparatively study them. The experimental procedure was conducted under repeatability conditions of measurement in order to determine the uncertainty associated to the optical properties of the biomaterials. Spectral variations of the refraction index and the scattering anisotropy factor were also considered. The whole experimental procedure fulfilled all the necessary requirements to provide optical-property values with lower associated uncertainties. The effective transport coefficient presented a similar spectral behavior for the two composites but completely different for the zirconia ceramic. The results demonstrated that the scattering anisotropy exerted a clearly distinct impact on the optical properties of the zirconia ceramic compared with those of the dental-resin composites.

  4. Recombination properties of diode structures by study of thermal emission beyond the fundamental absorption band

    International Nuclear Information System (INIS)

    Piotrowski, T; Wȩgrzecki, M; Czerwinski, A; Teslenko, G I; Malyutenko, O Y; Malyutenko, V K

    2014-01-01

    The study presents the possibilities of applying the measurement of spatial and temporal distribution of thermal radiation of a p-n junction structure located in a homogeneous temperature field higher than the ambient temperature, modulated by the presence of excess carriers injected through the junction, to determine surface recombination velocity at the injecting contact of the diode emitter and to measure the diffusion length in the base. Good agreement was obtained between the experimental results and calculations based on solutions of the transport equations.

  5. Ionizing radiations dosimetry: new results in the megagray range

    International Nuclear Information System (INIS)

    Balian, P.

    1989-01-01

    Industrial irradiation for food preservation, medical sterilization and plastic processing is in great expansion and an accurate dosimetry in the megagray range is required. It is also required for safety purposes around nuclear reactors or waste storage sites. The study of photon-matter interaction leads us to consider high-dose dosimeters among the solids in which radiolysis occurs. Organic conductors are indeed good candidates for high-dose dosimetry. These materials show original properties due to the great anisotropy of their electronic system. Radiation effects, especially on the resistivity and on the (E.S.R.) Electron Spin Resonance linewidth, are very important. We show that a simple resistance measurement allows an accurate monitoring of the absorbed dose, in the range 0.01 - 50 MGy, for X-rays, gamma-rays and electron irradiations. The E.S.R. linewidth measurements permits the use of small dosimeters between 1 and 100 MGy. Finally, some organic conductors are proposed as high-temperature dosimeters for irradiation performed up to 120 0 C. The irradiated pure silica contains a large variety of defects. Only the E' center seems helpful for dosimetry purposes, and its electron spin resonance (E.S.R.) signal is simply related to the absorbed dose in the range 0.1 - 3 MGy or even, 0.5 kGy - 5 MGy [fr

  6. A Comprehensive Review on the Properties of Coal Bottom Ash in Concrete as Sound Absorption Material

    OpenAIRE

    Ramzi Hannan Nurul Izzati Raihan; Shahidan Shahiron; Ali Noorwirdawati; Maarof Mohamad Zulkhairi

    2017-01-01

    The government is currently implementing policies to increase the usage of coal as fuel for electricity generation. At the same time, the dependency on gas will be reduced. In addition, coal power plants in Malaysia produce large amounts of industrial waste such as bottom ash which is collected in impoundment ponds (ash pond). However, millions of tons of coal ash (bottom ash) waste are collected in ponds near power plant stations. Since bottom ash has been classified as hazardous material th...

  7. Characterizing the absorption properties for remote sensing of three small optically-diverse South African reservoirs

    CSIR Research Space (South Africa)

    Matthews, MW

    2013-09-01

    Full Text Available grinding with a glass rod, the filter paper was incubated in the dark for 2 h at 37 °C and, then, stored in the cold for at least 20 h to allow for extraction. The samples were then diluted with Milli-Q water and centrifuged at 3,600 g for 15 min. to reduce... be performed more rapidly in the field [45]. However, there is some evidence Remote Sens. 2013, 5 4376 to suggest that NaClO treatment of samples with high dissolved organic matter may cause bleaching of colloidal/particle-bound organic matter, leading...

  8. The IAEA/WHO thermoluminescent dosimetry intercomparison used for the improvement of clinical dosimetry

    International Nuclear Information System (INIS)

    Racoveanu, N.T.

    1981-01-01

    Results of thermoluminescent dosimetry collected over 5 years in the Eastern Mediterranean region of WHO were analyzed in an attempt to improve clinical dosimetry. Data for 16 radiotherapy departments showed considerable inconsistencies. It was found that the clinical dosemeters used by 3 of the departments were not working properly. The remainder of the departments had one or more dosemeters in perfect working order but the procedure for measuring machine output was inadequate or the correction factors (pressure, temperature) were wrongly applied due to lack of reliable instruments for such measurements. Problems encountered in the sending and returning of TLD dosemeters for assessment are discussed

  9. Modern methods of personnel dosimetry

    International Nuclear Information System (INIS)

    Kraus, W.; Herrmann, D.; Kiesewetter, W.

    The physical properties of radiation detectors for personnel dosimetry are described and compared. The suitability of different types of dosimeters for operational and central monitoring of normal occupational exposure, for accident and catastrophe dosimetry and for background and space-flight dosimetry is discussed. The difficulties in interpreting the dosimeter reading with respect to the dose in individual body organs are discussed briefly. 430 literature citations (up to Spring 1966) are given

  10. Dosimetry for Crystals Irradiation

    CERN Document Server

    Lecomte, Pierre

    2005-01-01

    Before shipment to CMS, all PbWO4 crystals produced in China are irradiated there with 60 Co , in order to insure that the induced absorption coefficient is within specifications. Acceptance tests at CERNand at ENEA also include irradiation with gamma rays from 60 Co sources. There were initially discrepancies in quoted doses and doserates as well as in induced absorption coefficients. The present work resolves the discrepancies in irradiation measurements and defines common dosimetry methods for consistency checks between irradiation facilities.

  11. Absorption and Clearance of Pharmaceutical Aerosols in the Human Nose: Effects of Nasal Spray Suspension Particle Size and Properties.

    Science.gov (United States)

    Rygg, Alex; Hindle, Michael; Longest, P Worth

    2016-04-01

    The objective of this study was to use a recently developed nasal dissolution, absorption, and clearance (DAC) model to evaluate the extent to which suspended drug particle size influences nasal epithelial drug absorption for a spray product. Computational fluid dynamics (CFD) simulations of mucociliary clearance and drug dissolution were used to calculate total and microscale epithelial absorption of drug delivered with a nasal spray pump. Ranges of suspended particle sizes, drug solubilities, and partition coefficients were evaluated. Considering mometasone furoate as an example, suspended drug particle sizes in the range of 1-5 μm did not affect the total nasal epithelial uptake. However, the microscale absorption of suspended drug particles with low solubilities was affected by particle size and this controlled the extent to which the drug penetrated into the distal nasal regions. The nasal-DAC model was demonstrated to be a useful tool in determining the nasal exposure of spray formulations with different drug particle sizes and solubilities. Furthermore, the model illustrated a new strategy for topical nasal drug delivery in which drug particle size is selected to increase the region of epithelial surface exposure using mucociliary clearance while minimizing the drug dose exiting the nasopharynx.

  12. Dosimetry Service

    CERN Multimedia

    2006-01-01

    Cern Staff and Users can now consult their dose records for an individual or an organizational unit with HRT. Please see more information on our web page: http://cern.ch/rp-dosimetry Dosimetry Service is open every morning from 8.30 - 12.00. Closed in the afternoons. We would like to remind you that dosimeters cannot be sent to customers by internal mail. Short-term dosimeters (VCT's) must always be returned to the Service after the use and must not be left on the racks in the experimental areas or in the secretariats. Dosimetry Service Tel. 7 2155 Dosimetry.service@cern.ch http://cern.ch/rp-dosimetry

  13. Investigation of thermoluminescence properties of mobile phone screen displays as dosimeters for accidental dosimetry

    Science.gov (United States)

    Mrozik, Anna; Marczewska, B.; Bilski, P.; Kłosowski, M.

    2014-11-01

    The rapid assessment of the radiation dose after unexpected exposure is a task of accidental dosimetry. In case of a radiological accident glasses originating from mobile phone screens, placed usually near the human body, could be used as emergency thermoluminescent (TL) personal dosimeters. The time between irradiation and TL readout is crucial and therefore preparation of the mobile phone screens and their readout conditions should be optimized. The influence of the samples etching, bleaching and selection of the optical filters based on measurement of the emission spectrum of irradiated glass samples during heating for different types of mobile phones were the subjects of our investigation. Obtained results showed that glasses extracted from different brands of mobile phones have different dosimetric properties but all of them give a luminescent signal which can be used to calculate the dose.

  14. DRDC Ottawa Participation in the SILENE Accident Dosimetry Intercomparison Exercise. June 10-21, 2002

    National Research Council Canada - National Science Library

    Prud'homme-Lalonde, L

    2002-01-01

    .... The SILENE International Accident Dosimetry Intercomparison Exercise at Valduc, France in June 2002 coincided with DRDC Ottawa work designed to refine its proposed criticality dosimetry system...

  15. Personal dosimetry at the radiation accidents

    International Nuclear Information System (INIS)

    Perevoznikov, O.N.; Klyuchnikov, A.A.; Kanchenko, V.A.

    2007-01-01

    The radiation accidents of different types and the methods of the dosimetry used at the consequences liquidation are considered. The long-term experience of the population personal instrumental dosimetric control carrying out at the ChNPP accident consequences liquidation is widely covered in details. The concepts are stated out and the results are presented on the functioning of the created system for personal dose monitoring of the population of Ukraine irradiation. The use of the person radiation counters at the internal irradiation population and personal dose assessment is considered in details

  16. Study of nonlinear optical absorption properties of V{sub 2}O{sub 5} nanoparticles in the femtosecond excitation regime

    Energy Technology Data Exchange (ETDEWEB)

    Molli, Muralikrishna; Bhat Kademane, Abhijit; Pradhan, Prabin; Sai Muthukumar, V. [Sri Sathya Sai Institute of Higher Learning, Department of Physics, Puttaparthi, Andhra Pradesh (India)

    2016-08-15

    In this work, we report for the first time, the nonlinear optical absorption properties of vanadium pentoxide (V{sub 2}O{sub 5}) nanoparticles in the femtosecond excitation regime. V{sub 2}O{sub 5} nanoparticles were synthesized through solution combustion technique. The as-synthesized samples were further characterized using XRD, FESEM, EDAX, TEM and UV-visible spectroscopy. X-ray diffraction results revealed the crystalline nature of the nanoparticles. Electron microscopy studies showed the size of the nanoparticles to be ∝200 nm. Open-aperture z-scan technique was employed to study the nonlinear optical absorption behavior of the synthesized samples using a 100-fs laser pulses at 800 nm from a regeneratively amplified Ti: sapphire laser. The mechanism of nonlinear absorption was found to be a three-photon absorption process which was explained using the density of states of V{sub 2}O{sub 5} obtained using density functional theory. These nanoparticles exhibit strong intensity-dependent nonlinear optical absorption and hence could be considered for optical-power-limiting applications. (orig.)

  17. Dosimetry computer module of the gamma irradiator of ININ

    International Nuclear Information System (INIS)

    Ledezma F, L. E.; Baldomero J, R.; Agis E, K. A.

    2012-10-01

    This work present the technical specifications for the upgrade of the dosimetry module of the computer system of the gamma irradiator of the Instituto Nacional de Investigaciones Nucleares (ININ) whose result allows the integration and consultation of information in industrial dosimetry subject under an outline client-server. (Author)

  18. The next decade in external dosimetry

    International Nuclear Information System (INIS)

    Griffith, R.V.

    1986-10-01

    As the radiation protection community moves through the last half of the '80s and into the next decade, we can expect the requirements for external dosimetry to become increasingly more restrictive and demanding. As in other health protection fields, growing regulatory and legal pressures, together with a natural evolution in philosophy, require the health physicist to display an increasing degree of accountability, rigor, and professionalism. The good news is that, for the most part, the technology necessary to solve many of the problems will be available or not far behind. This paper describes anticipated technology. 66 refs., 10 figs

  19. Neutron dosimetry of the Little Boy device

    International Nuclear Information System (INIS)

    Pederson, R.A.; Plassmann, E.A.

    1984-01-01

    Neutron dose rates at several angular locations and at distances out to 0.5 mile have been measured during critical operation of the Little Boy replica. We used modified remmetes and thermoluminescent dosimetry techniques for the measurements. The present status of our analysis is presented including estimates of the neutron-dose-relaxation length in air and the variation of the neutron-to-gamma-ray dose ratio with distance from the replica. These results are preliminary and are subject to detector calibration measurements

  20. The Seibersdorf TL Personnel Dosimetry Service

    International Nuclear Information System (INIS)

    Duftschmid, K.E.

    1994-11-01

    Since 1976 the Department for Radiation Protection of the Austrian Research Centre Seibersdorf has been operating a TLD Personnel Monitoring Service, which presently covers about 18,000 radiation workers in Austria, with monthly monitoring periods. We have been the first accredited monitoring service in Europe, which fully converted from film dosimetry to TLD. From the beginning up to 1991 the service was based on three automated TLD systems Model 2271 from HARSHAW, USA. After extensive testing and comparisons, since almost four years now, the monitoring service has been operating on two HARSHAW 8800 systems, which are described in more detail below. (author)

  1. The Seibersdorf TL Personnel Dosimetry Service

    Energy Technology Data Exchange (ETDEWEB)

    Duftschmid, K E [Oesterreichisches Forschungszentrum Seibersdorf GmbH (Austria)

    1994-11-01

    Since 1976 the Department for Radiation Protection of the Austrian Research Centre Seibersdorf has been operating a TLD Personnel Monitoring Service, which presently covers about 18,000 radiation workers in Austria, with monthly monitoring periods. We have been the first accredited monitoring service in Europe, which fully converted from film dosimetry to TLD. From the beginning up to 1991 the service was based on three automated TLD systems Model 2271 from HARSHAW, USA. After extensive testing and comparisons, since almost four years now, the monitoring service has been operating on two HARSHAW 8800 systems, which are described in more detail below. (author).

  2. The JENDL-3 Sublibrary for Dosimetry. Summary of contents

    International Nuclear Information System (INIS)

    Nakazawa, M.; Kobayashi, K.; Iwasaki, S.; Iguchi, T.; Sakurai, K.; Ikeda, Y.; Nakagawa, T.

    1992-01-01

    This document summarizes the contents of the JENDL-3 Sublibrary for Dosimetry. This nuclear data library contains neutron activation cross-sections for selected materials that are used for reactor neutron dosimetry by foil activation. The library or retrievals of selected materials are available on magnetic tape from the IAEA Nuclear Data Section upon request. (author)

  3. Radiation dosimetry for the space shuttle program

    International Nuclear Information System (INIS)

    Jones, K.L.; Richmond, R.G.; Cash, B.L.

    1985-01-01

    Radiation measurements aboard the Space Shuttle are made to record crew doses for medical records, to verify analytical shielding calculations used in dose predictions and to provide dosimetry support for radiation sensitive payloads and experiments. Low cost systems utilizing thermoluminescent dosimeters, nuclear track detectors and activation foils have been developed to fulfill these requirements. Emphasis has been placed on mission planning and dose prediction. As a result, crew doses both inside the orbiter and during extra-vehicular activities have been reasonable low. Brief descriptions of the space radiation environment, dose prediction models, and radiation measurement systems are provided, along with a summary of the results for the first fourteen Shuttle flights

  4. The UK radiotherapy dosimetry audit network

    International Nuclear Information System (INIS)

    Thwaites, D.I.

    2002-01-01

    Full text: Radiotherapy dosimetry intercomparison in the UK has been carried out in limited studies since the 1960s. However the first national dosimetry intercomparison involving all radiotherapy centres was conducted in the late 1980s. This was based on visits to each centre, using ionisation chamber dosimetry. It audited megavoltage photon beam calibration and other single field parameters. It also measured doses in a three-field 'treatment' in a trapezoidal phantom constructed from epoxy-resin water-equivalent material and compared these to locally planned doses. This included off-axis points, oblique incidence, inhomogeneities, etc. The study found mean measured beam calibration doses close to stated values (ratio 1.003), with a standard deviation (sd) of the distribution of 1.5% and 97% of doses within the pro-set 3% tolerance. For the planned multi-field irradiations, mean dose ratios (measured/stated) were 1.01 (sd 3%, 90% of results within 5%). A number of discrepancies were identified, leading to improved practice. A follow up study (mid-1990s) for electron beam audit also repeated the megavoltage photon calibration audit. For photons, an improvement was noted (mean ratio 1.003, sd 1.0%, 100% within 3%), whilst for electron beams, the mean ratio of measured/stated dose was 0.994 (sd 1.8%, 94% within 3%, 99% within 5%). In parallel with - and growing out of - this, a national audit network began to develop in 1991/2. It utilised similar methodology to the intercomparison and a network approach to allow parallel developments of the scope of the system. The network has eight regional groups, each with up to 10 radiotherapy centres, serving average populations of 7-8 million. Each group organises audits of its own centres and has developed at its own pace. Most have piloted methodology, phantoms, etc. for new audits which can then be used by other groups. All 65 UK centres are included. The network is co-ordinated by an IPEM Steering Committee (current chair

  5. Dosimetry on the radiological risks prevention in radiotherapy

    International Nuclear Information System (INIS)

    Fornet R, O. M.; Perez G, F.

    2014-08-01

    Dosimetry in its various forms plays a determining role on the radiological risks prevention in radiotherapy. To prove this in this paper is shown an analysis based on the risk matrix method, how the dosimetry can influence in each stages of a radiotherapy service; installation and acceptance, operation, maintenance and calibration. For each one of these stages the role that can play is analyzed as either the initiating event of a radiological accident or limiting barrier of these events of the dosimetric processes used for the individual dosimetry, the area monitoring, fixed or portable, for radiation beam dosimetry and of the patients for a radiotherapy service with cobalt-therapy equipment. The result of the study shows that the application of a prospective approach in the role evaluation of dosimetry in the prevention and mitigation of the consequences of a radiological accident in radiotherapy is crucial and should be subject to permanent evaluation at each development stage of these services. (author)

  6. Use of the GATE Monte Carlo package for dosimetry applications

    Energy Technology Data Exchange (ETDEWEB)

    Visvikis, D. [INSERM U650, LaTIM, University Hospital Medical School, F 29609 Brest (France)]. E-mail: Visvikis.Dimitris@univ-brest.fr; Bardies, M. [INSERM U601, CHU Nantes, F 44093 Nantes (France); Chiavassa, S. [INSERM U601, CHU Nantes, F 44093 Nantes (France); Danford, C. [Department of Medical Physics, MSKCC, New York (United States); Kirov, A. [Department of Medical Physics, MSKCC, New York (United States); Lamare, F. [INSERM U650, LaTIM, University Hospital Medical School, F 29609 Brest (France); Maigne, L. [Departement de Curietherapie-Radiotherapie, Centre Jean Perrin, F 63000 Clemont-Ferrand (France); Staelens, S. [UGent-ELIS, St-Pietersnieuwstraat, 41, B 9000 Gent (Belgium); Taschereau, R. [CRUMP Institute for Molecular Imaging, UCLA, Los Angeles (United States)

    2006-12-20

    One of the roles for Monte Carlo (MC) simulation studies is in the area of dosimetry. A number of different codes dedicated to dosimetry applications are available and widely used today, such as MCNP, EGSnrc and PTRAN. However, such codes do not easily facilitate the description of complicated 3D sources or emission tomography systems and associated data flow, which may be useful in different dosimetry application domains. Such problems can be overcome by the use of specific MC codes such as GATE (GEANT4 Application to Tomographic Emission), which is based on Geant4 libraries, providing a scripting interface with a number of advantages for the simulation of SPECT and PET systems. Despite this potential, its major disadvantage is in terms of efficiency involving long execution times for applications such as dosimetry. The strong points and disadvantages of GATE in comparison to other dosimetry specific codes are discussed and illustrated in terms of accuracy, efficiency and flexibility. A number of features, such as the use of voxelised and moving sources, as well as developments such as advanced visualization tools and the development of dose estimation maps allowing GATE to be used for dosimetry applications are presented. In addition, different examples from dosimetry applications with GATE are given. Finally, future directions with respect to the use of GATE for dosimetry applications are outlined.

  7. Physical properties and thermoluminescence of glasses designed for radiation dosimetry measurements

    International Nuclear Information System (INIS)

    Laopaiboon, R.; Bootjomchai, C.

    2015-01-01

    Highlights: • TL stability of soda-lime glass was corrected by dopants. • D LDL values indicated that the glass samples have good radiation sensitivity. • Bond compression model theory was used to confirm the results from experimental. • High elastic moduli of glass samples indicated that high stability of structure. - Abstract: Soda lime glasses doped with CeO 2 , Nd 2 O 3 and MnO 2 were prepared. Thermoluminescence (TL) properties, such as glow curves and linearity of TL response on irradiation dose were investigated. Results showed that the TL properties depended on the type and concentration of the dopants. Samples were selected to calculate energy trap depth parameters. To design materials for radiation dosimetry, physical properties, ion concentration, elastic properties and effective atomic numbers are important. Theoretical bond compression models were used to determine the elastic moduli for comparison with experimental values. Results show fair agreement between theoretical and experimental measurements. The high elastic moduli of the glass samples indicated high rigidity and stability of the glass matrix structure

  8. Swelling pressure and water absorption property of compacted granular bentonite during water absorption

    International Nuclear Information System (INIS)

    Oyamada, T.; Komine, H.; Murakami, S.; Sekiguchi, T.; Sekine, I.

    2012-01-01

    Document available in extended abstract form only. Bentonite is currently planned to be used as buffer materials in engineered barrier of radioactive waste disposal. Granular bentonites are expected as the materials used in constructions as buffer materials by in-situ compaction methods. After applying these buffer materials, it is expected that the condition of the buffer area changes in long-term by the seepage of groundwater into buffer area. Therefore, it is important to understand water movement and swelling behavior of the buffer materials for evaluating the performance of engineered barrier. In this study, we investigated water absorption property and swelling pressure of compacted granular bentonite. Specifically, the process of swelling pressure and amount of water absorption of granular bentonite-GX (Kunigel-GX, produced at the Tsukinuno mine in Japan) were observed by laboratory tests. To discuss the influence of maximum grain size of bentonite particle on swelling pressure and water absorption property, two types of samples were used. One is granular sample which is Bentonite-GX controlled under 2 mm the maximum grain size, the other is milled sample which is Bentonite-GX with the maximum grain size under 0.18 mm by milling with the agate mortar. In addition, the mechanism on the swelling pressure of compacted granular bentonite was considered and discussed. In the cases of granular sample, swelling pressure increases rapidly, then gradually continues to increase up to maximum value. In the cases of milled sample, swelling pressure also increases rapidly at first. However, then its value decreases before progressing of gradual increase continues. Especially, this trend was clearly observed at a relatively low dry density. At the peaks of these curves, the swelling pressure of granular samples is lower than that of milled samples. In addition, the increasing of swelling pressure by the time the peak observed during the process of swelling pressure from

  9. Properties of Commercial PVC Films with Respect to Electron Dosimetry

    DEFF Research Database (Denmark)

    Miller, Arne; Liqing, Xie

    The properties of three commercially available polyvinyl chloride (PVC) film supplies and one made without additives were tested with respect to their application as routine dose monitors at electron accelerators. Dose fractionation was found to increase the response and the post-irradiation heat...

  10. Practical applications of the new ICRP recommendation to external dosimetry

    International Nuclear Information System (INIS)

    Kraus, W.

    1992-01-01

    Focussing on external dosimetry for occupational exposure the consequences of the new quantities equivalent dose (radiation weighting factor), effective dose (tissue weighting factor) and the ICRU operational quantities for individual and area dosimetry are discussed. Despite some arguments against the new quantities they should be introduced as rapidly as possible to keep international uniformity in radiation protection monitoring. It is shown that they provide a conservative estimate of the effective dose for photons and neutrons. In photon dosimetry only minor changes of the conversion factors relating operational quantities to effective dose is observed. In neutron dosimetry the conversion factors change by a factor of up to 2. It is pointed out that there is a urgent need to calculate standardized conversion factors for field quantities -operational quantities- organ and effective dose in a joint effort of ICRP and ICRU. This includes standardization of calibration methods for individual dosimetry using suitable phantoms instead of the sphere. (author)

  11. Dosimetry system of the RB reactor; Dozimetarski sistem reaktora RB

    Energy Technology Data Exchange (ETDEWEB)

    Lolic, B; Vukadin, D [Boris Kidric Institute of nuclear sciences, Vinca, Belgrade (Yugoslavia)

    1962-07-01

    Although RB reactor is operated at very low power levels, safety and dosimetry systems have high importance. This paper shows detailed dosimetry system with fundamental typical components. Estimated radiation doses dependent on reactor power are given at some characteristic points in the rooms nearby reactor.

  12. Effect of Maleated Compatibiliser (PBS-g-MA) Addition on the Flexural Properties and Water Absorption of Poly(butylene succinate)/ kenaf Bast Fibre Composites

    International Nuclear Information System (INIS)

    Ahmad, M.Z.T.; Mohd, Z.A.M.; Mat, R.T.; Ahmad, M.Z.T.; Mohd, Z.A.I.; Mat, R.T.; Rahim, S.

    2013-01-01

    Poly(butylene succinate) (PBS) composites with 30 wt.% loading of kenaf bast fibre (KBF) were compatibilised with 5 wt. % maleated PBS (PBS-g-MA). The maleic anhydride (MA) concentration in the compatibiliser was either 3, 5, 7 or 10 phr. In general, the compatibilised composites showed better flexural properties than the un-compatibilised composite. The highest increment in the flexural strength and modulus of 12.7 and 8.9 %, respectively, were obtained with the addition of PBS-g-MA with MA concentration of 5 phr. Compatibilised and un-compatibilised PBS/ KBF composites were immersed in distilled water for 90 days. The absorption of water by all the composites was observed to follow Ficks law. The equilibrium moisture content, M m , of the composites with PBS-g-MA at 3, 5 and 7 phr of MA concentrations was lower than that of the un-compatibilised composite due to improved fiber-matrix interfacial adhesion and reduction of voids content. Both un-compatibilised and compatibilised composites showed dimensional instability after the water absorption. This was probably due to the degradation of the fibre-matrix interfacial adhesion and fibre integrity. The flexural properties of these composites decreased after the water absorption. After re-drying only some of the flexural properties were recovered from plasticizing effect of water. (author)

  13. Investigation of the dosimetry of chest tomosynthesis

    Science.gov (United States)

    Svalkvist, Angelica; Zachrisson, Sara; Månsson, Lars Gunnar; Båth, Magnus

    2009-02-01

    Chest tomosynthesis has recently been introduced to healthcare as a low-dose alternative to CT or as a tool for improved diagnostics in chest radiography with only a modest increase in radiation dose to the patient. However, no detailed description of the dosimetry for this type of examination has been presented. The aim of this work was therefore to investigate the dosimetry of chest tomosynthesis. The chest tomosynthesis examination was assumed to be performed using a stationary detector and a vertically moving x-ray tube, exposing the patient from different angles. The Monte Carlo based computer software PCXMC was used to determine the effective dose delivered to a standard-sized patient from various angles using different assumptions of the distribution of the effective dose over the different projections. The obtained conversion factors between input dose measures and effective dose for chest tomosynthesis for different angular intervals were then compared with the horizontal projection. The results indicate that the error introduced by using conversion factors for the PA projection in chest radiography for estimating the effective dose of chest tomosynthesis is small for normally sized patients, especially if a conversion factor between KAP and effective dose is used.

  14. The importance of 3D dosimetry

    International Nuclear Information System (INIS)

    Low, Daniel

    2015-01-01

    Radiation therapy has been getting progressively more complex for the past 20 years. Early radiation therapy techniques needed only basic dosimetry equipment; motorized water phantoms, ionization chambers, and basic radiographic film techniques. As intensity modulated radiation therapy and image guided therapy came into widespread practice, medical physicists were challenged with developing effective and efficient dose measurement techniques. The complex 3-dimensional (3D) nature of the dose distributions that were being delivered demanded the development of more quantitative and more thorough methods for dose measurement. The quality assurance vendors developed a wide array of multidetector arrays that have been enormously useful for measuring and characterizing dose distributions, and these have been made especially useful with the advent of 3D dose calculation systems based on the array measurements, as well as measurements made using film and portal imagers. Other vendors have been providing 3D calculations based on data from the linear accelerator or the record and verify system, providing thorough evaluation of the dose but lacking quality assurance (QA) of the dose delivery process, including machine calibration. The current state of 3D dosimetry is one of a state of flux. The vendors and professional associations are trying to determine the optimal balance between thorough QA, labor efficiency, and quantitation. This balance will take some time to reach, but a necessary component will be the 3D measurement and independent calculation of delivered radiation therapy dose distributions

  15. The importance of 3D dosimetry

    Science.gov (United States)

    Low, Daniel

    2015-01-01

    Radiation therapy has been getting progressively more complex for the past 20 years. Early radiation therapy techniques needed only basic dosimetry equipment; motorized water phantoms, ionization chambers, and basic radiographic film techniques. As intensity modulated radiation therapy and image guided therapy came into widespread practice, medical physicists were challenged with developing effective and efficient dose measurement techniques. The complex 3-dimensional (3D) nature of the dose distributions that were being delivered demanded the development of more quantitative and more thorough methods for dose measurement. The quality assurance vendors developed a wide array of multidetector arrays that have been enormously useful for measuring and characterizing dose distributions, and these have been made especially useful with the advent of 3D dose calculation systems based on the array measurements, as well as measurements made using film and portal imagers. Other vendors have been providing 3D calculations based on data from the linear accelerator or the record and verify system, providing thorough evaluation of the dose but lacking quality assurance (QA) of the dose delivery process, including machine calibration. The current state of 3D dosimetry is one of a state of flux. The vendors and professional associations are trying to determine the optimal balance between thorough QA, labor efficiency, and quantitation. This balance will take some time to reach, but a necessary component will be the 3D measurement and independent calculation of delivered radiation therapy dose distributions.

  16. Fluorescence and absorption properties of chromophoric dissolved organic matter (CDOM) in coastal surface waters of the Northwestern Mediterranean Sea (Bay of Marseilles, France)

    OpenAIRE

    J. Para; P. G. Coble; B. Charrière; M. Tedetti; C. Fontana; R. Sempéré

    2010-01-01

    Seawater samples were collected in surface waters (2 and 5 m depths) of the Bay of Marseilles (Northwestern Mediterranean Sea; 5°17′30′′ E, 43°14′30′′ N) during one year from November 2007 to December 2008 and studied for total organic carbon (TOC) as well as chromophoric dissolved organic matter (CDOM) optical properties (absorbance and fluorescence). The annual mean value of surface CDOM absorption coefficient ...

  17. About the factors distorting biological dosimetry results

    International Nuclear Information System (INIS)

    Mosseh, I.B.

    1999-01-01

    The row of chemical substances that have not mutagenic effect can strengthen ionising radiation induced cytogenetic effects. For example nitrite sodium and nitrate sodium reinforce mutagenic action of radiation and cause sensitized effect although they aren't mutagens. Presence of residual amount of herbicides in food products can have influence at level of aberration in human cells. It was investigated the influence of herbicide zencor at mutagenic action of radiation. This substance has weak mutagenic activity. In the case of combined action of zencor with irradiation antagonistic effect was observed. Mutation rate turns out to be lower than expected summary value. At the same time many foods products (tea, coffee, cacao, chocolate etc., which contain melanin) are antimutagens and can also change the frequency of radiation induced mutations. Taking of medicine distort the results of dose estimation. The frequency of chromosomal aberrations in blood lymphocytes after acute irradiation is considered to be adequate method of biological dosimetry. In the case of chronic irradiation this analysis becomes complicated with such processes as adaptation (selection and proliferation of cells with more radioresistant genotype) and the origin of genetic un stability which leads to higher radiosensitivity. The estimation of the level of point mutations is the most precise method of biological dosimetry because their existence is less exposed to modifications

  18. On the influence of the condensed particles on the absorption properties of plasma created by ablation controlled arc in a capillary

    Science.gov (United States)

    Pashchina, A. S.; Valyano, G. E.

    2017-11-01

    The results of experimental studies of the absorption properties of plasma created by ablation controlled arc in a capillary are presented. It is shown that the dominant influence on the plasma absorption properties is exerted by condensed particles formed in relatively low-temperature zones in the vicinity of the capillary wall and on the periphery of the plasma jet, whereas the plasma bremsstrahlung is optically thin. The nonmonotonic behavior of the plasma optical thickness in the spectral range Δλ=400-700 nm, as well as amplification of the probing radiation in a relatively narrow wavelength interval Δλ=628±5 nm, caused, probably, by resonant excitation of condensed particles by electromagnetic radiation, are detected. The estimations of the condensed particles parameters (the average size dD≈2-4 nm, the concentration ND=(1-5)·1013 cm-3, the volume fraction fV≈(0.1-3)·10-6), which quantitatively consistent with the results of studies of the microstructure of the condensed phase on scanning electron microscope, have been obtained.

  19. Polymer gel dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Baldock, C [Institute of Medical Physics, School of Physics, University of Sydney (Australia); De Deene, Y [Radiotherapy and Nuclear Medicine, Ghent University Hospital (Belgium); Doran, S [CRUK Clinical Magnetic Resonance Research Group, Institute of Cancer Research, Surrey (United Kingdom); Ibbott, G [Radiation Physics, UT M D Anderson Cancer Center, Houston, TX (United States); Jirasek, A [Department of Physics and Astronomy, University of Victoria, Victoria, BC (Canada); Lepage, M [Centre d' imagerie moleculaire de Sherbrooke, Departement de medecine nucleaire et de radiobiologie, Universite de Sherbrooke, Sherbrooke, QC (Canada); McAuley, K B [Department of Chemical Engineering, Queen' s University, Kingston, ON (Canada); Oldham, M [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Schreiner, L J [Cancer Centre of South Eastern Ontario, Kingston, ON (Canada)], E-mail: c.baldock@physics.usyd.edu.au, E-mail: yves.dedeene@ugent.be

    2010-03-07

    Polymer gel dosimeters are fabricated from radiation sensitive chemicals which, upon irradiation, polymerize as a function of the absorbed radiation dose. These gel dosimeters, with the capacity to uniquely record the radiation dose distribution in three-dimensions (3D), have specific advantages when compared to one-dimensional dosimeters, such as ion chambers, and two-dimensional dosimeters, such as film. These advantages are particularly significant in dosimetry situations where steep dose gradients exist such as in intensity-modulated radiation therapy (IMRT) and stereotactic radiosurgery. Polymer gel dosimeters also have specific advantages for brachytherapy dosimetry. Potential dosimetry applications include those for low-energy x-rays, high-linear energy transfer (LET) and proton therapy, radionuclide and boron capture neutron therapy dosimetries. These 3D dosimeters are radiologically soft-tissue equivalent with properties that may be modified depending on the application. The 3D radiation dose distribution in polymer gel dosimeters may be imaged using magnetic resonance imaging (MRI), optical-computerized tomography (optical-CT), x-ray CT or ultrasound. The fundamental science underpinning polymer gel dosimetry is reviewed along with the various evaluation techniques. Clinical dosimetry applications of polymer gel dosimetry are also presented. (topical review)

  20. Absorption properties of metal-semiconductor hybrid nanoparticles.

    Science.gov (United States)

    Shaviv, Ehud; Schubert, Olaf; Alves-Santos, Marcelo; Goldoni, Guido; Di Felice, Rosa; Vallée, Fabrice; Del Fatti, Natalia; Banin, Uri; Sönnichsen, Carsten

    2011-06-28

    The optical response of hybrid metal-semiconductor nanoparticles exhibits different behaviors due to the proximity between the disparate materials. For some hybrid systems, such as CdS-Au matchstick-shaped hybrids, the particles essentially retain the optical properties of their original components, with minor changes. Other systems, such as CdSe-Au dumbbell-shaped nanoparticles, exhibit significant change in the optical properties due to strong coupling between the two materials. Here, we study the absorption of these hybrids by comparing experimental results with simulations using the discrete dipole approximation method (DDA) employing dielectric functions of the bare components as inputs. For CdS-Au nanoparticles, the DDA simulation provides insights on the gold tip shape and its interface with the semiconductor, information that is difficult to acquire by experimental means alone. Furthermore, the qualitative agreement between DDA simulations and experimental data for CdS-Au implies that most effects influencing the absorption of this hybrid system are well described by local dielectric functions obtained separately for bare gold and CdS nanoparticles. For dumbbell shaped CdSe-Au, we find a shortcoming of the electrodynamic model, as it does not predict the "washing out" of the optical features of the semiconductor and the metal observed experimentally. The difference between experiment and theory is ascribed to strong interaction of the metal and semiconductor excitations, which spectrally overlap in the CdSe case. The present study exemplifies the employment of theoretical approaches used to describe the optical properties of semiconductors and metal nanoparticles, to achieve better understanding of the behavior of metal-semiconductor hybrid nanoparticles.

  1. Magnetic properties and microwave absorption properties of short ...

    Indian Academy of Sciences (India)

    als in the high-frequency range owing to their fascinating properties.2,3 However, .... Ni deposition.24 Owing to the low solubility of carbon in iron and nickel, Ni–Fe ... real (μ ) and imaginary (μ ) of complex permeability of the. Fe0.21Ni0.69/CF ...

  2. Sound Absorption Properties Of Single-Hole Hollow Polyester Fiber Reinforced Hydrogenated Carboxyl Nitrile Rubber Composites

    Directory of Open Access Journals (Sweden)

    Jie Hong

    2017-09-01

    Full Text Available A series of single-hole hollow polyester fiber (SHHPF reinforced hydrogenated carboxyl nitrile rubber (HXNBR composites were fabricated. In this study, the sound absorption property of the HXNBR/SHHPF composite was tested in an impedance tube, the composite morphology was characterized by scanning electron microscope (SEM, and the tensile mechanical property was measured by strength tester. The results demonstrated that a remarkable change in sound absorption can be observed by increasing the SHHPF content from 0% to 40%. In the composite with 40% SHHPF in 1 mm thickness, the sound absorption coefficient reached 0.671 at 2,500 Hz; the effective bandwidth was 1,800-2,500 Hz for sound absorption coefficient larger than 0.2. But the sound absorption property of the composite deteriorated when the SHHPF content increased to 50% in 1 mm thickness. While with 20% SHHPF proportion, the sound absorption property was improved by increasing the thickness of composites from 1 to 5 mm. Compared with the pure HXNBR of the same thickness, the tensile mechanical property of the composite improved significantly by increasing the SHHPF proportion. As a lightweight composite with excellent sound absorption property, the HXNBR/SHHPF composite has potential practical application value in the fields of engineering.

  3. Reassessment of the RERF dosimetry system - overview of the new dosimetry system DS02

    International Nuclear Information System (INIS)

    Young, R.W.

    2003-01-01

    This paper describes a major reassessment of the system used at the Radiation Effects Research Foundation (RERF) to determine radiation doses for atomic-bomb survivors. This effort has resolved the neutron discrepancy in RERF dosimetry, and has defined the parameters for a replacement system for survivor dose calculation. A Joint US-Japan Working Group undertook a comprehensive evaluation of the calculations that comprise the RERF dosimetry system and the measurements used to verify those calculations. During the course of this reassessment, the working groups, with members from American, German and Japanese universities and national laboratories, have recomputed all of the Hiroshima and Nagasaki radiation calculations, made fast-neutron and low-background thermal-neutron measurements, upgraded the calculation of the radiation shielding provided by terrain and large buildings, and conducted a comprehensive reassessment of all radiation measurements. The new calculations produced during this reassessment agree with both gamma and neutron measurements out to distances from the detonations at which in-situ measurements become indistinguishable from background, effectively resolving the long-standing neutron dose discrepancy. The calculations that produce this agreement are the basis for the new DS02 dosimetry system. New calculations and measurements confirmed the yield and epicenter for the Nagasaki detonation while refining both these values for Hiroshima. Current measurements and calculations confirm a 21-kiloton-yield for the Nagasaki bomb and a burst point to within two meters of previous assessments. In Hiroshima, the estimated yield has been increased from 15 kt to 16 kt and the epicenter has been repositioned 20 meters higher and 15 meters to the west. While these refined parameters make the dosimetry system more accurate and users of the system more confident in the results, the calculated dose to survivors will change only about ten percent

  4. Neutron personnel dosimetry

    International Nuclear Information System (INIS)

    Griffith, R.V.

    1981-01-01

    The current state-of-the-art in neutron personnel dosimetry is reviewed. Topics covered include dosimetry needs and alternatives, current dosimetry approaches, personnel monitoring devices, calibration strategies, and future developments

  5. Dosimetry of the gastrointestinal tract

    International Nuclear Information System (INIS)

    Sullivan, M.F.; Cross, F.T.; Dagle, G.E.

    1987-01-01

    In order to obtain information on radiation doses to the intestine, doses were determined in dogs for beta-emitters ( 106 Ru- 106 Rh, 147 Pm and 91 Y) that might be delivered to critical cells in the bowel in the event of an accident. Thermoluminescent dosimeters were implanted beneath the large-bowel mucose of dogs. Results were related to toxicity in the dogs and extrapolated to toxicity observed in other experiments with suckling, weanling and adult rats similarly treated. With that information the depth of the critical cells in both dogs and rats could be calculated. Studies with isotopes of thorium, uranium, protactinium, neptunium, plutonium, americium, curium and einsteinium showed that substantial amounts of these alpha-emitting actinides were retained in the intestines of neonatal rats, guinea pigs, dogs and swine after gavage. Despite high doses retained by mucosal cells on the villous tips, (some epithelial cells in the ileum received 100 Gy/day) gross injury was seldom observed at necropsy. 26 refs.; 4 figs.; 3 tabs

  6. A study of the cool gas in the Large Magellanic Cloud. I. Properties of the cool atomic phase - a third H i absorption survey

    Science.gov (United States)

    Marx-Zimmer, M.; Herbstmeier, U.; Dickey, J. M.; Zimmer, F.; Staveley-Smith, L.; Mebold, U.

    2000-02-01

    The cool atomic interstellar medium of the Large Magellanic Cloud (LMC) seems to be quite different from that in the Milky Way. In a series of three papers we study the properties of the cool atomic hydrogen in the LMC (Paper I), its relation to molecular clouds using SEST-CO-observations (Paper II) and the cooling mechanism of the atomic gas based on ISO-[\\CII]-investigations (Paper III). In this paper we present the results of a third 21 cm absorption line survey toward the LMC carried out with the Australia Telescope Compact Array (ATCA). 20 compact continuum sources, which are mainly in the direction of the supergiant shell LMC 4, toward the surroundings of 30 Doradus and toward the eastern steep \\HI\\ boundary, have been chosen from the 1.4 GHz snapshot continuum survey of Marx et al. We have identified 20 absorption features toward nine of the 20 sources. The properties of the cool \\HI\\ clouds are investigated and are compared for the different regions of the LMC taking the results of Dickey et al. (survey 2) into account. We find that the cool \\HI\\ gas in the LMC is either unusually abundant compared to the cool atomic phase of the Milky Way or the gas is clearly colder (\\Tc\\ ~ 30 K) than that in our Galaxy (\\Tc\\ ~ 60 K). The properties of atomic clouds toward 30 Doradus and LMC 4 suggest a higher cooling rate in these regions compared to other parts of the LMC, probably due to an enhanced pressure near the shock fronts of LMC 4 and 30 Doradus. The detected cool atomic gas toward the eastern steep \\HI\\ boundary might be the result of a high compression of gas at the leading edge. The Australia Telescope is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO.

  7. HSE statement on the approval of dosimetry services

    International Nuclear Information System (INIS)

    1992-09-01

    This statement is intended to assist dosimetry services who may wish to be approved by the U.K. Health and Safety Executive under Regulation 15 of the Ionising Radiations Regulations 1985. It also serves to inform approved dosimetry services of changes in the arrangements which HSE makes for approval and reassessment of dosimetry services. A general description of the administrative arrangements for making application is given and the subsequent processing of such applications by the HSE is outlined. Background notes on the requirements of the Regulations are given in Appendix I. The fees which are chargeable from 20/8/92 are given in Appendix II. (Author)

  8. Physical properties of the interstellar medium using high-resolution Chandra spectra: O K-edge absorption

    Energy Technology Data Exchange (ETDEWEB)

    Gatuzz, E.; Mendoza, C. [Centro de Física, Instituto Venezolano de Investigaciones Científicas (IVIC), P.O. Box 20632, Caracas 1020A (Venezuela, Bolivarian Republic of); García, J. [Harvard-Smithsonian Center for Astrophysics, MS-6, 60 Garden Street, Cambridge, MA 02138 (United States); Kallman, T. R. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Bautista, M. A.; Gorczyca, T. W., E-mail: egatuzz@ivic.gob.ve, E-mail: claudio@ivic.gob.ve, E-mail: javier@head.cfa.harvard.edu, E-mail: manuel.bautista@wmich.edu, E-mail: thomas.gorczyca@wmich.edu, E-mail: timothy.r.kallman@nasa.gov [Department of Physics, Western Michigan University, Kalamazoo, MI 49008 (United States)

    2014-08-01

    Chandra high-resolution spectra toward eight low-mass Galactic binaries have been analyzed with a photoionization model that is capable of determining the physical state of the interstellar medium. Particular attention is given to the accuracy of the atomic data. Hydrogen column densities are derived with a broadband fit that takes into account pileup effects, and in general are in good agreement with previous results. The dominant features in the oxygen-edge region are O I and O II Kα absorption lines whose simultaneous fits lead to average values of the ionization parameter of log ξ = –2.90 and oxygen abundance of A{sub O} = 0.70. The latter is given relative to the standard by Grevesse and Sauval, but rescaling with the revision by Asplund et al. would lead to an average abundance value fairly close to solar. The low average oxygen column density (N{sub O} = 9.2 × 10{sup 17} cm{sup –2}) suggests a correlation with the low ionization parameters, the latter also being in evidence in the column density ratios N(O II)/N(O I) and N(O III)/N(O I) that are estimated to be less than 0.1. We do not find conclusive evidence for absorption by any other compound but atomic oxygen in our oxygen-edge region analysis.

  9. Fluorescence and absorption properties of chromophoric dissolved organic matter (CDOM) in coastal surface waters of the northwestern Mediterranean Sea, influence of the Rhône River

    OpenAIRE

    J. Para; P. G. Coble; B. Charrière; M. Tedetti; C. Fontana; R. Sempéré

    2010-01-01

    Seawater samples were collected monthly in surface waters (2 and 5 m depths) of the Bay of Marseilles (northwestern Mediterranean Sea; 5°17'30" E, 43°14'30" N) during one year from November 2007 to December 2008 and studied for total organic carbon (TOC) as well as chromophoric dissolved organic matter (CDOM) optical properties (absorbance and fluorescence). The annual mean value of surface CDOM absorption coefficient at 350 nm [aCDOM(350)] was very l...

  10. Dosimetry, measurement and properties of radon daughters and thoron daughters

    International Nuclear Information System (INIS)

    Phillips, C.R.

    1982-03-01

    Various properties of radon and thoron daughter products are examined. Dosimeter methods and instrumentation (TLD and personal alpha dosimeters) are investigated as to performance under varying conditions such as humidity and pure or mixed atmospheric conditions. Optimized counting schemes are determined for the daughters of radon and thoron. An optimized counting scheme was experimentally examined under mine conditions. The optimization procedure takes into account the uncertainties associated with concentration, flow rate and radioactive decay. Measurements were made in two uranium mines at Elliot Lake, Ontario of the charged and unattached fractions of radon daughters in the mines. The physicochemical state of 218 Po in air was determined by measurement of rate of neutralization, diffusion coefficient and fraction born charge. Careful control of experimental conditions made it possible to obtain more precise and detailed quantitative data than previously possible

  11. Radiation protection and environmental dosimetry: Role of the dosimetry laboratory

    International Nuclear Information System (INIS)

    Trotta, M V; Gonzalez Sintas, M F; Cerchietti, M L; Arguelles, M G

    2012-01-01

    This paper presents the different methods used routinely, the calculation of dose in an analytical result and the radiochemical new developments, as well as the strategies employed in the implementation of various tools of the quality system (author)

  12. Study of TSL and OSL properties of dental ceramics for accidental dosimetry applications

    International Nuclear Information System (INIS)

    Veronese, Ivan; Galli, Anna; Cantone, Marie Claire; Martini, Marco; Vernizzi, Fabrizio; Guzzi, Gianpaolo

    2010-01-01

    Interest is increasing in the development of new methodologies for accidental dose assessment, exploiting the luminescence and dosimetric properties of objects and materials which can be usually found directly on exposed subjects and/or in the contaminated area. In this work, several types of ceramics employed for dental prosthetics restoration, including both innovative materials used as sub-frames for the construction of the inner part of dental crowns (core), and conventional porcelains used for the fabrication of the external layer (veneer), were investigated with regard to their thermally and optically stimulated luminescence (TSL and OSL respectively) properties, in view of their potential application in accidental dosimetry. The sensitivity to ionizing radiation proved to strongly depend on the type and brand of ceramic, with minimum detectable dose ranging from few mGy up to several tens of mGy. A linear dose-response was observed for most of the samples. However, the luminescence signals were characterised by a significant fading, which has to be taken into account for a reliable accidental dose assessment after a radiation exposure event.

  13. Nanofluid optical property characterization: towards efficient direct absorption solar collectors

    Directory of Open Access Journals (Sweden)

    Otanicar Todd

    2011-01-01

    Full Text Available Abstract Suspensions of nanoparticles (i.e., particles with diameters < 100 nm in liquids, termed nanofluids, show remarkable thermal and optical property changes from the base liquid at low particle loadings. Recent studies also indicate that selected nanofluids may improve the efficiency of direct absorption solar thermal collectors. To determine the effectiveness of nanofluids in solar applications, their ability to convert light energy to thermal energy must be known. That is, their absorption of the solar spectrum must be established. Accordingly, this study compares model predictions to spectroscopic measurements of extinction coefficients over wavelengths that are important for solar energy (0.25 to 2.5 μm. A simple addition of the base fluid and nanoparticle extinction coefficients is applied as an approximation of the effective nanofluid extinction coefficient. Comparisons with measured extinction coefficients reveal that the approximation works well with water-based nanofluids containing graphite nanoparticles but less well with metallic nanoparticles and/or oil-based fluids. For the materials used in this study, over 95% of incoming sunlight can be absorbed (in a nanofluid thickness ≥10 cm with extremely low nanoparticle volume fractions - less than 1 × 10-5, or 10 parts per million. Thus, nanofluids could be used to absorb sunlight with a negligible amount of viscosity and/or density (read: pumping power increase.

  14. Parity-Forbidden Transitions and Their Impact on the Optical Absorption Properties of Lead-Free Metal Halide Perovskites and Double Perovskites.

    Science.gov (United States)

    Meng, Weiwei; Wang, Xiaoming; Xiao, Zewen; Wang, Jianbo; Mitzi, David B; Yan, Yanfa

    2017-07-06

    Using density functional theory calculations, we analyze the optical absorption properties of lead (Pb)-free metal halide perovskites (AB 2+ X 3 ) and double perovskites (A 2 B + B 3+ X 6 ) (A = Cs or monovalent organic ion, B 2+ = non-Pb divalent metal, B + = monovalent metal, B 3+ = trivalent metal, X = halogen). We show that if B 2+ is not Sn or Ge, Pb-free metal halide perovskites exhibit poor optical absorptions because of their indirect band gap nature. Among the nine possible types of Pb-free metal halide double perovskites, six have direct band gaps. Of these six types, four show inversion symmetry-induced parity-forbidden or weak transitions between band edges, making them not ideal for thin-film solar cell applications. Only one type of Pb-free double perovskite shows optical absorption and electronic properties suitable for solar cell applications, namely, those with B + = In, Tl and B 3+ = Sb, Bi. Our results provide important insights for designing new metal halide perovskites and double perovskites for optoelectronic applications.

  15. The Bristol University neutron dosimetry system

    International Nuclear Information System (INIS)

    Worley, A.; Fews, A.P.; Henshaw, D.L.

    1987-01-01

    The neutron dosimetry system developed at Bristol is based on recording recoil proton tracks in conventionally etched PADC plastic using a fully automated image analysis system. Two features contribute to the achievement of a low dose threshold: high quality plastic is manufactured and undergoes extensive quality control tests prior to acceptance for use in dosimetry, and a readout system with high efficiency for rejecting background events is used. The principal dosemeter that has been developed consists of three orthogonal elements, each containing two 3 cm x 1 cm plastics on either side of a polyethylene radiator. On each plastic an area of 0.15 cm 2 is scanned giving a total active area of 0.90 cm 2 . Each plastic is coded for manual identification and for computer recognition. The track counts from the six plastics are added with different weightings to achieve a measure of dose which is independent of irradiation direction when worn on the body. The device has been calibrated using monoenergetic neutrons in the range 100 keV to 14.7 MeV at NPL, and using the recent CENDOS exposure. If the track counts are added without weighting, the device has a nominal response of 120 tracks cm -2 .mSv -1 and an energy threshold at 200 keV. Taken together with a background of 20 track cm -2 , a dose threshold of around 80μSv is implied. A simpler dosemeter, using a single plastic/radiator combination, may also be considered. If a 1 cm 2 device is used for normal incidence exposure, the dose threshold is calculated to be 25 μSv. (author)

  16. Hydrogen absorption-desorption properties of U2Ti

    International Nuclear Information System (INIS)

    Yamamoto, Takuya; Tanaka, Satoru; Yamawaki, Michio

    1990-01-01

    Hydrogen absorption-desorption properties of U 2 Ti intermetallic compound was examined over the temperature range of 298 to 973 K and at hydrogen pressures below 10 5 Pa. It absorbs hydrogen up to 7.6 atoms per F.U. (formula unit) by two step reactions and hence each desorption isotherm is separated into two plateau regions. In the first plateau, a newly-found ternary hydride is formed, where the hydrogen concentration, c H , reaches 2.4 H atoms/F.U. In the second plateau, UH 3 is formed and c H reaches 7.6 H atoms/F.U. The specimen is disintegrated into fine powder in the second plateau, while in the first plateau the ternary hydride which was identified to be UTi 2 H x (x=4.8 to 6.2) showed high durability against powdering. It is predicted that UTi 2 can be suitable material for tritium storage. (orig.)

  17. Coupled light transport-heat diffusion model for laser dosimetry with dynamic optical properties

    International Nuclear Information System (INIS)

    London, R.A.; Glinsky, M.E.; Zimmerman, G.B.; Eder, D.C.; Jacques, S.L.

    1995-01-01

    The effect of dynamic optical properties on the spatial distribution of light in laser therapy is studied via numerical simulations. A two-dimensional, time dependent computer program called LATIS is used. Laser light transport is simulated with a Monte Carlo technique including anisotropic scattering and absorption. Thermal heat transport is calculated with a finite difference algorithm. Material properties are specified on a 2-D mesh and can be arbitrary functions of space and time. Arrhenius rate equations are solved for tissue damage caused by elevated temperatures. Optical properties are functions of tissue damage, as determined by previous measurements. Results are presented for the time variation of the light distribution and damage within the tissue as the optical properties of the tissue are altered

  18. Gamma-ray dosimetry measurements of the Little Boy replica

    International Nuclear Information System (INIS)

    Plassmann, E.A.; Pederson, R.A.

    1984-01-01

    We present the current status of our gamma-ray dosimetry results for the Little Boy replica. Both Geiger-Mueller and thermoluminescent detectors were used in the measurements. Future work is needed to test assumptions made in data analysis

  19. The physics of small megavoltage photon beam dosimetry.

    Science.gov (United States)

    Andreo, Pedro

    2018-02-01

    The increased interest during recent years in the use of small megavoltage photon beams in advanced radiotherapy techniques has led to the development of dosimetry recommendations by different national and international organizations. Their requirement of data suitable for the different clinical options available, regarding treatment units and dosimetry equipment, has generated a considerable amount of research by the scientific community during the last decade. The multiple publications in the field have led not only to the availability of new invaluable data, but have also contributed substantially to an improved understanding of the physics of their dosimetry. This work provides an overview of the most important aspects that govern the physics of small megavoltage photon beam dosimetry. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Quality audit service of the IAEA for radiation processing dosimetry

    International Nuclear Information System (INIS)

    Mehta, K.; Girzikowsky, R.

    1996-01-01

    The mandate of the International Atomic Energy Agency includes assistance to Member States to establish nuclear technologies safely and effectively. In pursuit of this, a quality audit service for dosimetry relevant to radiation processing was initiated as a key element of the High-Dose Standardization Programme of the IAEA. The standardization of dosimetry for radiation processing provides a justification for the regulatory approval of irradiated products and their unrestricted international trade. In recent times, the Agency's Dosimetry Laboratory has placed concentrated effort towards establishing a quality assurance programme based on the ISO 9000 series documents. The need for reliable and accurate dosimetry for radiation processing is increasing in Member States and we can envisage a definite role for the SSDLs in such a programme. (author). 10 refs, 3 figs

  1. Experimental investigation of sound absorption properties of perforated date palm fibers panel

    International Nuclear Information System (INIS)

    Elwaleed, A K; Nikabdullah, N; Nor, M J M; Tahir, M F M; Zulkifli, R

    2013-01-01

    This paper presents the sound absorption properties of a natural waste of date palm fiber perforated panel. A single layer of the date palm fibers was tested in this study for its sound absorption properties. The experimental measurements were carried out using impedance tube at the acoustic lab, Faculty of Engineering, Universiti Kebangsaan Malaysia. The experiment was conducted for the panel without air gap, with air gap and with perforated plate facing. Three air gap thicknesses of 10 mm, 20 mm and 30 mm were used between the date palm fiber sample and the rigid backing of the impedance tube. The results showed that when facing the palm date fiber sample with perforated plate the sound absorption coefficient improved at the higher and lower frequency ranges. This increase in sound absorption coincided with reduction in medium frequency absorption. However, this could be improved by using different densities or perforated plate with the date palm fiber panel.

  2. The personnel dosimetry record keeping system at AEE Winfrith

    International Nuclear Information System (INIS)

    Gill, D.W.

    1979-09-01

    Since May 1978 the exposure of personnel to external radiation has been assessed by Thermoluminescent Dosimetry, (TLD). The dosemeter consists of a TLD card similar to that used by the National Radiological Protection Board, held in a plastic badge designed at AEE Winfrith, and used in conjunction with a D A Pitman Ltd Type 605 Automatic Reader. The report describes the dosemeter, the operation of the dosimetry service and the system for maintaining a computerised record keeping system. (author)

  3. Patient skin dosimetry in interventional cardiology in the Czech Republic

    International Nuclear Information System (INIS)

    Sukupova, L.; Novak, L.; Kala, P.; Cervinka, P.; Stasek, J.

    2011-01-01

    In this study, skin dosimetry of patients undergoing interventional cardiology procedures is presented. Three hospitals were included. Two methods were used for skin dosimetry-radiochromic dosimetry films and reconstruction of skin dose distribution based on examination protocol. Maximum skin doses (MSD) obtained from both methods were compared for 175 patients. For patients for whom the film MSD was >1 Gy, the reconstruction MSD differed from the film MSD in the range of ± 50 % for 83 % of patients. For remaining patients, the difference was higher and it was caused by longer fluoroscopy time. For 59 patients for whom the cumulative dose was known, the cumulative dose was compared with the film MSD. Skin dosimetry with radiochromic films is more accurate than the reconstruction method, but films do not include X-ray fields from lateral projections whilst reconstructions do. (authors)

  4. Lyoluminescence dosimetry of the radiation in industrial doses

    International Nuclear Information System (INIS)

    Vigna Filho, E. del.

    1984-01-01

    The γ-rays lyoluminescence (LL) dosimetry study is presented. The basic principles involved, both in the method and radiation dosimetry, the equivalence between water and lyoluminescent materials, apparatus, irradiation technique and calibration method are discussed. The LL response dependence with environmental conditions are presented. These were temperature, humidity, storage time and the dependence on dissolved mass. A pre-reading thermal treatment was developed to overcome previous difficulties. The developed technique was applied to dose intercomparisons. (M.A.C.) [pt

  5. Absorption properties of waste matrix materials

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, J.B. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1997-06-01

    This paper very briefly discusses the need for studies of the limiting critical concentration of radioactive waste matrix materials. Calculated limiting critical concentration values for some common waste materials are listed. However, for systems containing large quantities of waste materials, differences up to 10% in calculated k{sub eff} values are obtained by changing cross section data sets. Therefore, experimental results are needed to compare with calculation results for resolving these differences and establishing realistic biases.

  6. Proceedings of the third conference on radiation protection and dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Swaja, R.E.; Sims, C.S.; Casson, W.H. [eds.

    1991-10-01

    The Third Conference on Radiation Protection and Dosimetry was held during October 21--24, 1991, at the Sheraton Plaza Hotel in Orlando, Florida. This meeting was designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection, and providing them with sufficient information to evaluate their programs. To meet these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection was prepared. General topics considered in the technical session included external dosimetry, internal dosimetry, instruments, accident dosimetry, regulations and standards, research advances, and applied program experience. In addition, special sessions were held to afford attendees the opportunity to make short presentations of recent work or to discuss topics of general interest. Individual reports are processed separately on the database.

  7. Proceedings of the third conference on radiation protection and dosimetry

    International Nuclear Information System (INIS)

    Swaja, R.E.; Sims, C.S.; Casson, W.H.

    1991-10-01

    The Third Conference on Radiation Protection and Dosimetry was held during October 21--24, 1991, at the Sheraton Plaza Hotel in Orlando, Florida. This meeting was designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection, and providing them with sufficient information to evaluate their programs. To meet these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection was prepared. General topics considered in the technical session included external dosimetry, internal dosimetry, instruments, accident dosimetry, regulations and standards, research advances, and applied program experience. In addition, special sessions were held to afford attendees the opportunity to make short presentations of recent work or to discuss topics of general interest. Individual reports are processed separately on the database

  8. Dosimetry program for characterization of the FMIT facility

    International Nuclear Information System (INIS)

    Gold, R.; McElroy, W.N.; Fuller, J.L.; Sheen, E.M.; Dierckx, R.

    1979-01-01

    The environmental characterization program for the Fusion Materials Irradiaton Test (FMIT) facility is presented. Requirements for the development and testing of Magnetic Fusion Energy (MFE) materials together with the complexity of the FMIT (d,Li) generated radiation field warrant a multifaceted dosimetric approach. Specific passive, active and calculational dosimetry efforts comprising this multifaceted approach are described. Special emphasis is given to those dosimetry capabilities uniquely required to characterize FMIT

  9. Characterization of the thermoluminescent detectors LiF:Mg,Cu,P. Environmental dosimetry applications

    International Nuclear Information System (INIS)

    Ciocci Brazzano, Ligia; Gregori, Beatriz N.; Papadopulos, Susana B.; Carelli, Jorge L.

    2005-01-01

    Studies on thermal-luminescent properties of the LiF:Mg detectors, Cu, P enrichment with Li-7 (99.93% of Li-7 and 0.07% of Li-6): optimization of the heating profile, loss of information, detection limit and doses and energy responses are presented in this work. Their performance is compared with LiF:Mg detectors, Mg, Ti enriched with Li-7 (99.93% of Li-7 and 0.07% Li-6), which are at present used for environmental dosimetry at the Physics Dosimetry Laboratory of the Nuclear Regulatory Authority [es

  10. Electronic properties and optical absorption of a phosphorene quantum dot

    Science.gov (United States)

    Liang, F. X.; Ren, Y. H.; Zhang, X. D.; Jiang, Z. T.

    2018-03-01

    Using the tight-binding Hamiltonian approach, we theoretically study the electronic and optical properties of a triangular phosphorene quantum dot (PQD) including one normal zigzag edge and two skewed armchair edges (ZAA-PQD). It is shown that the energy spectrum can be classified into the filled band (FB), the zero-energy band (ZB), and the unfilled band (UB). Numerical calculations of the FB, ZB, and UB probability distributions show that the FB and the UB correspond to the bulk states, while the ZB corresponds to the edge states, which appear on all of the three edges of the ZAA-PQD sharply different from the other PQDs. We also find that the strains and the electric fields can affect the energy levels inhomogeneously. Then the optical properties of the ZAA-PQD are investigated. There appear some strong low-energy optical absorption peaks indicating its sensitive low-energy optical response that is absent in other PQDs. Moreover, the strains and the electric fields can make inhomogeneous influences on the optical spectrum of the ZAA-PQD. This work may provide a useful reference for designing the electrical, mechanical, and optical PQD devices.

  11. Determining the lower limit of detection for personnel dosimetry systems

    International Nuclear Information System (INIS)

    Roberson, P.L.; Carlson, R.D.

    1992-01-01

    A simple method for determining the lower limit of detection (LLD) for personnel dosimetry systems is described. The method relies on the definition of a critical level and a detection level. The critical level is the signal level above which a result has a small probability of being due to a fluctuation of the background. All results below the critical level should not be reported as an indication of a positive result. The detection level is the net signal level (i.e., dose received) above which there is a high confidence that a true reading will be detected and reported as a qualitatively positive result. The detection level may be identified as the LLD. A simple formula is derived to allow the calculation of the LLD under various conditions. This type of formula is being used by the Department of Energy Laboratory Accreditation Program (DOELAP) for personnel dosimetry. Participants in either the National Voluntary Laboratory Accreditation Program (NVLAP) for personnel dosimetry or DOELAP can use performance test results along with a measurement of background levels to estimate the LLDs for their dosimetry system. As long as they maintain their dosimetry system such that the LLDs are less than half the lower limit of the NVLAP or DOELAP test exposure ranges, dosimetry laboratories can avoid testing failures due to poor performance at very low exposures

  12. Nonlinear absorption and transmission properties of Ge, Te and InAs using tuneable IR FEL

    Energy Technology Data Exchange (ETDEWEB)

    Amirmadhi, F.; Becker, K.; Brau, C.A. [Vanderbilt Univ., Nashville, TN (United States)

    1995-12-31

    Nonlinear absorption properties of Ge, Te and InAs are being investigated using the transmission of FEL optical pulses through these semiconductors (z-scan method). Wavelength, intensity and macropulse dependence are used to differentiate between two-photon and free-carrier absorption properties of these materials. Macropulse dependence is resolved by using a Pockles Cell to chop the 4-{mu}s macropulse down to 100 ns. Results of these experiments will be presented and discussed.

  13. Absorption and fluorescence properties of chromophoric dissolved organic matter of the eastern Bering Sea in the summer with special reference to the influence of a cold pool

    Science.gov (United States)

    D'Sa, E. J.; Goes, J. I.; Gomes, H.; Mouw, C.

    2014-06-01

    The absorption and fluorescence properties of chromophoric dissolved organic matter (CDOM) are reported for the inner shelf, slope waters and outer shelf regions of the eastern Bering Sea during the summer of 2008, when a warm, thermally stratified surface mixed layer lay over a cold pool (CDOM absorption at 355 nm (ag355) and its spectral slope (S) in conjunction with excitation-emission matrix (EEM) fluorescence and parallel factor analysis (PARAFAC) revealed large variability in the characteristics of CDOM in different regions of the Bering Sea. PARAFAC analysis aided in the identification of three humic-like (components one, two and five) and two protein-like (a tyrosine-like component three, and a tryptophan-like component four) components. In the extensive shelf region, average absorption coefficients at 355 nm (ag355, m-1) and DOC concentrations (μM) were highest in the inner shelf (0.342 ± 0.11 m-1, 92.67 ± 14.60 μM) and lower in the middle (0.226 ± 0.05 m-1, 78.38 ± 10.64 μM) and outer (0.185 ± 0.05 m-1, 79.24 ± 18.01 μM) shelves, respectively. DOC concentrations, however were not significantly different, suggesting CDOM sources and sinks to be uncoupled from DOC. Mean spectral slopes S were elevated in the middle shelf (24.38 ± 2.25 μm-1) especially in the surface waters (26.87 ± 2.39 μm-1) indicating high rates of photodegradation in the highly stratified surface mixed layer, which intensified northwards in the northern middle shelf likely contributing to greater light penetration and to phytoplankton blooms at deeper depths. The fluorescent humic-like components one, two, and five were most elevated in the inner shelf most likely from riverine inputs. Along the productive "green belt" in the outer shelf/slope region, absorption and fluorescence properties indicated the presence of fresh and degraded autochthonous DOM. Near the Unimak Pass region of the Aleutian Islands, low DOC and ag355 (mean 66.99 ± 7.94 μM; 0.182 ± 0.05 m-1) and a

  14. Pharmacokinetics and dosimetry of the anti-androgen vinclozolin after oral administration inthe rat

    Science.gov (United States)

    Vinclozolin (V) is a fungicide with antiandrogenic properties. To determine the pharmacokinetics and dosimetry of V, adult male rats were administered an oral dose of V (100 mg/kg) in corn oil and sacrificed over time after dosing. V and its metabolites were analyzed in serum and...

  15. Proceedings of the recent developments in radiation dosimetry

    International Nuclear Information System (INIS)

    Bhat, Nagesh; Palani Selvan, T.

    2016-01-01

    Whilst 'Dosimetry' in its original sense deals with methods for a quantitative determination of energy deposited in a given medium by directly or indirectly ionizing radiations, the term is better known as a scientific sub-specialty in the fields of health physics and medical physics, where it is the calculation and assessment of the radiation dose received by the human body. Dosimetry is used extensively for radiation protection and is routinely applied to ensure radiological safety of occupational radiation workers. Internal dosimetry due to the ingestion or inhalation of radioactive materials relies on a variety of physiological or imaging techniques. External dosimetry, due to irradiation from an external source is based on measurements with a dosimeter, or inferred from other radiological protection instruments. Radiation dosimetry is one of the important research areas of Department of Atomic Energy (DAE). This research work is centered on the facilities such as nuclear reactors, reprocessing plants, high energy accelerators (research/industry/medical), radiation standards, food processing, radiation technology development, etc. In each of these facilities, radiation field environment is different and the associated dosimetry concepts are different. Papers relevant to INIS are indexed separately

  16. Dynamical Evolution of Properties for Atom and Field in the Process of Two-Photon Absorption and Emission Between Atomic Levels

    Science.gov (United States)

    Wang, Jian-ming; Xu, Xue-xiang

    2018-04-01

    Using dressed state method, we cleverly solve the dynamics of atom-field interaction in the process of two-photon absorption and emission between atomic levels. Here we suppose that the atom is initially in the ground state and the optical field is initially in Fock state, coherent state or thermal state, respectively. The properties of the atom, including the population in excited state and ground state, the atom inversion, and the properties for optical field, including the photon number distribution, the mean photon number, the second-order correlation function and the Wigner function, are discussed in detail. We derive their analytical expressions and then make numerical analysis for them. In contrast with Jaynes-Cummings model, some similar results, such as quantum Rabi oscillation, revival and collapse, are also exhibit in our considered model. Besides, some novel nonclassical states are generated.

  17. TL/OSL properties of natural schist for archaeological dating and retrospective dosimetry

    International Nuclear Information System (INIS)

    Afouxenidis, D.; Stefanaki, E.C.; Polymeris, G.S.; Sakalis, A.; Tsirliganis, N.C.; Kitis, G.

    2007-01-01

    Schist, a metamorphic rock composed largely of quartz and muscovite, has been used as a building stone through the centuries in many parts of the world. In ancient Greece, it was used in buildings and monuments (Knossos, Karthaia, etc). Basic TL and OSL properties of schist are studied in the present work to evaluate its potential use in archaeological dating and retrospective dosimetry. In particular, the optical stability, as well as the linearity of the TL and OSL signal were investigated for samples of natural schist obtained from a roofing slate. The results indicate that both signals are rapidly bleached when the sample is exposed to sunlight. An exposure of 1 min reduces the TL signal by 93%, the IRSL signal by 99% and the post-IR BSL signal by 90%. The dose response was found to be linear for a radiation dose at least up to 75 Gy for the TL and the IR OSL signal and at least up to 25 Gy for the post-IR BSL signal

  18. An experimental study of the electronic absorption and fluorescence spectral properties of new p-substituted-N-phenylpyrroles and their electrosynthesized polymers.

    Science.gov (United States)

    Diaw, A K D; Gningue-Sall, D; Yassar, A; Brochon, J-C; Henry, E; Aaron, J-J

    2015-01-25

    Electronic absorption and fluorescence spectral properties of new p-substituted-N-phenylpyrroles (N-PhPys), including HOPhPy, MeOPhPy, ThPhPy, PhDPy, DPhDPy, PyPhThThPhPy, and their available, electrosynthesized polymers were investigated. Electronic absorption spectra, fluorescence excitation and emission spectra, fluorescence quantum yields (ΦF) and lifetimes (τF), and other photophysical parameters of these N-PhPy derivatives and their polymers were measured in DMF, DMSO diluted solutions and/or solid state at room temperature. The electronic absorption spectra of N-PhPy derivatives and their polymers included one to several bands, located in the 270-395 nm region, according to the p-phenyl substituent electron-donating effect and conjugated heteroaromatic system length. The fluorescence excitation spectra were characterized by one broad main peak, with, in most cases, one (or more) poorly resolved shoulder (s), appearing in the 270-405 nm region, and their emission spectra were generally constituted of several bands located in the 330-480 nm region. No significant shift of the absorption, fluorescence excitation and emission spectra wavelengths was found upon going from the monomers to the corresponding polymers. ΦF values were high, varying between 0.11 and 0.63, according to the nature of substituents(s) and to the conjugated system extension. Fluorescence decays were mono-exponential for the monomers and poly-exponential for PyPhThThPhPy and for polymers. τF values were relatively short (0.35-5.17 ns), and markedly decreased with the electron-donor character of the phenyl group p-substituent and the conjugated system extension. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Influence of Glycidyl Methacrylate Grafting on the Mechanical, Water Absorption, and Thermal Properties of Recycled High-Density Polyethylene/Rubber Seed Shell Particle Composites

    Directory of Open Access Journals (Sweden)

    Kaimeng Xu

    2016-01-01

    Full Text Available Rubber seed shell (RSS was modified by grafting treatment using glycidyl methacrylate (GMA at various concentrations. The RSS was then used to reinforce high-density polyethylene (HDPE. The effects of modification on the mechanical, water absorption, and thermal properties of the RSS/HDPE composites were studied using a mechanical testing instrument, weighing method, Vicat softening temperature (VST testing, thermogravimetry, and dynamic mechanical analysis. The results showed that the GMA grafting produced an improvement in the flexural and tensile properties of the composites. The water absorption rate of the composites also had an obvious decrease. While a slight increase in VST was found, the various concentrations of GMA showed no improvement in VST. GMA modification also could elevate the thermal stability of the composites at the initial decomposition stage. The optimum grafting concentration of GMA (2.5% led to the lowest thermal weight loss (37.07% and 26.56% during the first and second decomposition stages. The E’ values of the composites had a significant increase with the addition of GMA. There were two peaks of tan δ for the untreated samples, but the modified samples exhibited a shift in the transition peak at higher temperatures; moreover, the second peak disappeared.

  20. Investigation of thermoluminescence properties of mobile phone screen displays as dosimeters for accidental dosimetry

    International Nuclear Information System (INIS)

    Mrozik, Anna; Marczewska, B.; Bilski, P.; Kłosowski, M.

    2014-01-01

    The rapid assessment of the radiation dose after unexpected exposure is a task of accidental dosimetry. In case of a radiological accident glasses originating from mobile phone screens, placed usually near the human body, could be used as emergency thermoluminescent (TL) personal dosimeters. The time between irradiation and TL readout is crucial and therefore preparation of the mobile phone screens and their readout conditions should be optimized. The influence of the samples etching, bleaching and selection of the optical filters based on measurement of the emission spectrum of irradiated glass samples during heating for different types of mobile phones were the subjects of our investigation. Obtained results showed that glasses extracted from different brands of mobile phones have different dosimetric properties but all of them give a luminescent signal which can be used to calculate the dose. - Highlights: • Application of acids mixture for more effective glass samples etching. • Bleaching can be performed not only by blue but also by UV light. • The readout with BG39 optical filter improves the TL signal intensity. • The glass samples from touch mobile phones are worse emergency TL dosimeters

  1. ESR/tooth enamel dosimetry application to Chernobyl case: individual retrospective dosimetry of the liquidators and wild animals

    International Nuclear Information System (INIS)

    Bugai, A.; Baryakchtar, V.G.; Baran, N.

    1996-01-01

    ESR/tooth enamel dosimetry technique was used for individual retrospective dosimetry of the servicemen who had worked in 1986-1987 at the liquidation of consequences of the Chernobyl accident. For 18 investigated cases, the values varied from 0,10 (sensitivity limit) to 1,75 Gy. The same technique was used for individual dosimetry of wild animals boars, red deers, elks) hunted at contaminated 30-km area around the Chernobyl Power Plant. Measured values varied from 0,20 to 5,0 Gy/year and were compared with calculated for external and internal irradiation

  2. Characterization of chemical compounds for dosimetry of the radiation in industrial processes

    International Nuclear Information System (INIS)

    Galante, Ana Maria Sisti

    1999-01-01

    Different chemical compounds have been studied to optimize dosimetric systems in irradiation processes. In this study 2,3,5 Triphenyl -2H- Tetrazolium Chloride, Brilliant Cresyl Blue, Bromocresol Green and Potassium Nitrate were investigated for their merits or faults, for 60 Co gamma field, in order to verify if can be considered as dosimeters. Fricke solution was used as reference dosimeter to determine absorption dose rates at the gamma facilities.Only Bromocresol Green and Potassium Nitrate are recommended for dosimetry purposes since the main characteristics were achieved. The other two compounds could be used in dosimetry with changes in their formulation. Bromocresol Green and potassium Nitrate are reproducible and radiation sensitive for absorbed doses from 300 Gy to 150 kGy Bromocresol Green was used in liquid form and Potassium Nitrate was prepared in solid pellets form. Spectrophotometry in the visible region was used as the main detection technique, which allows relating optical absorption, before and after irradiation, with the absorbed dose. The maximum absorption wavelength for each compound was observed at 450-460nm for bromocresol Green and 546nm for Potassium Nitrate. Dose calibration curves are linear for both compounds in all dose intervals. When irradiated with accelerated electrons, with energies between o,9 MeV and 1,5MeV, optical absorption intensification, of about 2,6 times, was observed when comparing results for Potassium Nitrate, with those for gamma rays. All the evaluations are presented in this work. (author)

  3. Multi-Spectral Remote Sensing of Phytoplankton Pigment Absorption Properties in Cyanobacteria Bloom Waters: A Regional Example in the Western Basin of Lake Erie

    Directory of Open Access Journals (Sweden)

    Guoqing Wang

    2017-12-01

    Full Text Available Phytoplankton pigments absorb sunlight for photosynthesis, protect the chloroplast from damage caused by excess light energy, and influence the color of the water. Some pigments act as bio-markers and are important for separation of phytoplankton functional types. Among many efforts that have been made to obtain information on phytoplankton pigments from bio-optical properties, Gaussian curves decomposed from phytoplankton absorption spectrum have been used to represent the light absorption of different pigments. We incorporated the Gaussian scheme into a semi-analytical model and obtained the Gaussian curves from remote sensing reflectance. In this study, a series of sensitivity tests were conducted to explore the potential of obtaining the Gaussian curves from multi-spectral satellite remote sensing. Results showed that the Gaussian curves can be retrieved with 35% or less mean unbiased absolute percentage differences from MEdium Resolution Imaging Spectrometer (MERIS and Moderate Resolution Imaging Spectroradiometer (MODIS-like sensors. Further, using Lake Erie as an example, the spatial distribution of chlorophyll a and phycocyanin concentrations were obtained from the Gaussian curves and used as metrics for the spatial extent of an intense cyanobacterial bloom occurred in Lake Erie in 2014. The seasonal variations of Gaussian absorption properties in 2011 were further obtained from MERIS imagery. This study shows that it is feasible to obtain Gaussian curves from multi-spectral satellite remote sensing data, and the obtained chlorophyll a and phycocyanin concentrations from these Gaussian peak heights demonstrated potential application to monitor harmful algal blooms (HABs and identification of phytoplankton groups from satellite ocean color remote sensing semi-analytically.

  4. Use of the calorimeter in the dosimetry for electron accelerators

    International Nuclear Information System (INIS)

    Chavez B, A.

    1991-02-01

    The measure of different radiation types, with specific dosemeters, requires that the absorbed dose should be measured with accuracy by some common standard. The existent problem around the dosimetry of accelerated electrons has forced to the development of diverse detector types that after having analyzed the characteristics; dependability and reproducibility are used as dosemeters. Recently the calorimeters have been developed, with the purpose of carrying out dosimetry for electron accelerators. The RISO laboratory in Denmark, in it 10 MeV accelerator had been used for the dosimetry those water calorimeters, later on, using the principle of the water calorimeter, it was designing one similar, for the accelerator of 400 keV. Recently manufactured simple calorimeters of graphite have been used, which can be used in both accelerators of 10 MeV and 400 keV. (Author)

  5. Dosimetry Service

    CERN Multimedia

    2005-01-01

    Please remember to read your dosimeter at least once a month. Regular read-outs are vital to ensure that your personal dose is periodically monitored. Dosimeters should be read even if you have not visited the controlled areas. Dosimetry Service - Tel. 7 2155 http://cern.ch/rp-dosimetry

  6. Dosimetry Service

    CERN Multimedia

    Dosimetry Service

    2005-01-01

    Please remember to read your dosimeter at least once a month. Regular read-outs are vital to ensure that your personal dose is periodically monitored. Dosimeters should be read even if you have not visited the controlled areas. Dosimetry Service Tel. 7 2155 http://cern.ch/rp-dosimetry

  7. Dosimetry Service

    CERN Multimedia

    2005-01-01

    Please remember to read your dosimeter at least once a month. Regular read-outs are vital to ensure that your personal dose is periodically monitored. Dosimeters should be read even if you have not visited the controlled areas. Dosimetry Service - Tel. 72155 http://cern.ch/rp-dosimetry

  8. The thermoluminscent dosimetry service of the radiation protection bureau

    International Nuclear Information System (INIS)

    1978-12-01

    Thermoluminescent materials have been used in radiation dosimetry for many years, but their application to nationwide personnel dosimetry has been scarce. An undertaking of this nature requires that methods be established for identification of dosimeters and for fast interpretation and communication of dose to the users across the country. It is also necessary that records of cumulative dose of individual radiation workers be continuously updated, and such records be maintained for a prolonged period. To do this many problems pertinent to associated equpment, vis. the computer, TL reader, their interfacing, and to the operational procedures of the service had to be resolved. Since April 1977, the Radiation Protection Bureau has been providing a Thermoluminescent Dosimetry Service to Canadian radiation workers. This document describes the RPB dosimeter, its characteristics, various aspects of the service, objectives of the service, and how the objective goals of the service are achieved. (auth)

  9. Seasonal variation and light absorption property of carbonaceous aerosol in a typical glacier region of the southeastern Tibetan Plateau

    Science.gov (United States)

    Niu, Hewen; Kang, Shichang; Wang, Hailong; Zhang, Rudong; Lu, Xixi; Qian, Yun; Paudyal, Rukumesh; Wang, Shijin; Shi, Xiaofei; Yan, Xingguo

    2018-05-01

    Deposition and accumulation of light-absorbing carbonaceous aerosol on glacier surfaces can alter the energy balance of glaciers. In this study, 2 years (December 2014 to December 2016) of continuous observations of carbonaceous aerosols in the glacierized region of the Mt. Yulong and Ganhaizi (GHZ) basin are analyzed. The average elemental carbon (EC) and organic carbon (OC) concentrations were 1.51±0.93 and 2.57±1.32 µg m-3, respectively. Although the annual mean OC / EC ratio was 2.45±1.96, monthly mean EC concentrations during the post-monsoon season were even higher than OC in the high altitudes (approximately 5000 m a. s. l. ) of Mt. Yulong. Strong photochemical reactions and local tourism activities were likely the main factors inducing high OC / EC ratios in the Mt. Yulong region during the monsoon season. The mean mass absorption efficiency (MAE) of EC, measured for the first time in Mt. Yulong, at 632 nm with a thermal-optical carbon analyzer using the filter-based method, was 6.82±0.73 m2 g-1, comparable with the results from other studies. Strong seasonal and spatial variations of EC MAE were largely related to the OC abundance. Source attribution analysis using a global aerosol-climate model, equipped with a black carbon (BC) source tagging technique, suggests that East Asia emissions, including local sources, have the dominant contribution (over 50 %) to annual mean near-surface BC in the Mt. Yulong area. There is also a strong seasonal variation in the regional source apportionment. South Asia has the largest contribution to near-surface BC during the pre-monsoon season, while East Asia dominates the monsoon season and post-monsoon season. Results in this study have great implications for accurately evaluating the influences of carbonaceous matter on glacial melting and water resource supply in glacierization areas.

  10. Reference dosimetry for CT in the UK

    International Nuclear Information System (INIS)

    Shrimpton, P.C.; Wall, B.F.

    2001-01-01

    Computed tomography is firmly established as a major source of population exposure from diagnostic x-ray examinations and thus a particular focus for radiological protection initiatives. The concept of reference doses is widely recognised as a useful and practical tool for promoting improvements in the optimisation of protection for patients undergoing radiological examinations. National diagnostic reference levels (DRLs) have already been successfully applied in the UK for some conventional x-ray examinations within a framework for advice on patient protection. This approach is being extended to include CT, utilising the robust methodology for reference dosimetry that has been developed by the European Commission (EC) for the particular conditions of exposure in CT. This is based on the dosimetric concepts of weighted computed tomography dose index (CTDI w ) per slice in serial scanning or per rotation in helical scanning, and dose-length product (DLP) per complete examination. Notwithstanding some initial values proposed by the EC, specific national DRLs for CT practice in the UK will be established on the basis of widescale national survey data. (author)

  11. The Hiroshima neutron dosimetry enigma: Missing puzzle piece No. 6

    International Nuclear Information System (INIS)

    Gold, Raymond

    1999-01-01

    More than a decade has elapsed since the serious nature of the discrepancy between neutron dosimetry experiments (E) and neutron transport calculations (C) for the Hiroshima site was identified. Since that time extensive efforts to resolve this Hiroshima neutron dosimetry enigma have not only failed, but now demonstrate that the magnitude of this discrepancy is much greater than initially estimated. The currently evaluated E/C ratio for thermal neutron fluence at the Hiroshima site increases rapidly with increasing slant range from the epicenter. In the slant range region beyond 1000 m, E/C exceeds unity by one to two orders of magnitude depending on the specific dosimetry data that are utilized. Principal features that characterize the Hiroshima neutron dosimetry enigma are summarized. Puzzle Piece No. 6: In-situ production and Prompt fallout of radionuclides from Little Boy is advanced as a possible contributory phenomenon to this enigma. (The atom bomb detonated over Hiroshima was called Little Boy.) Measurements of 60 Co and 152 Eu specific activity at the Hiroshima site are used to obtain order of magnitude numerical estimates that show this conjecture is plausible. Comparison of different 60 Co measurements at the Hiroshima site reveals that the variation of E/C with slant range depends on the method used to quantify 60 Co specific activity as well as the type of dosimetry samples that are employed. These 60 Co comparisons lend additional qualitative credence to this conjecture. Within the limits of presently available data, these assessments show that Puzzle Piece No. 6 qualitatively satisfies the principal features that characterize the Hiroshima neutron dosimetry enigma. Nevertheless, current lack of data prevent this conjecture from being conclusively confirmed or refuted. Consequently, specific recommendations are advanced to resolve the Hiroshima neutron dosimetry enigma with emphasis on experimental tests that can quantitatively evaluate Puzzle Piece

  12. Thermoluminescent properties of CVD diamond: applications to ionising radiation dosimetry; Proprietes thermoluminescentes du diamant CVD: applications a la dosimetrie des rayonnements ionisants

    Energy Technology Data Exchange (ETDEWEB)

    Petitfils, A

    2007-09-15

    Remarkable properties of synthetic diamond (human soft tissue equivalence, chemical stability, non-toxicity) make this material suitable for medical application as thermoluminescent dosimeter (TLD). This work highlights the interest of this material as radiotherapy TLD. In the first stage of this work, we looked after thermoluminescent (TL) and dosimetric properties of polycrystalline diamond made by Chemically Vapor Deposited (CVD) synthesis. Dosimetric characteristics are satisfactory as TLD for medical application. Luminescence thermal quenching on diamond has been investigated. This phenomenon leads to a decrease of dosimetric TL peak sensitivity when the heating rate increases. The second part of this work analyses the use of synthetic diamond as TLD in radiotherapy. Dose profiles, depth dose distributions and the cartography of an electron beam obtained with our samples are in very good agreement with results from an ionisation chamber. It is clearly shown that CVD) diamond is of interest to check beams of treatment accelerators. The use of these samples in a control of treatment with Intensity Modulated Radiation Therapy underlines good response of synthetic diamond in high dose gradient areas. These results indicate that CVD diamond is a promising material for radiotherapy dosimetry. (author)

  13. The effect of Ni pre-implantation on surface morphology and optical absorption properties of Ag nanoparticles embedded in SiO2

    International Nuclear Information System (INIS)

    Shen, Yanyan; Qi, Ting; Qiao, Yu; Yu, Shengwang; Hei, Hongjun; He, Zhiyong

    2016-01-01

    Graphical abstract: - Highlights: • Ag concentration increased significantly due to the Ni pre-implantation. • Deposition and accumulation process of Ag atoms depends on Ni fluences. • The incorporation of Ni elements in Ag NPs can damp SPR absorption intensity. • AgNi alloy NPs embedded in SiO 2 have been created by sequentially implantation. • Unique SPR absorption with dual peaks centered at 406 nm and 563 nm was observed. - Abstract: The effect of Ni ion fluence on Ag nucleation and particle growth was investigated by sequentially implantation of 60 keV Ni ions at fluences of 1 × 10 16 , 5 × 10 16 , 1 × 10 17 ions/cm 2 and 70 keV Ag ions at a fluence of 5 × 10 16 ions/cm 2 . Due to the modification of the deposition and accumulation process of Ag implants caused by Ni pre-implantation, the surface morphology, structures, and optical absorption properties of the Ag nanoparticles (NPs) depends strongly on the Ni fluences. UV–vis absorption spectroscopy study showed that the introducing of Ni atoms lead to intensity decrease in the Ag SPR band. Remarkable local concentration increase of Ag profiles appeared for the sample pre-implanted by Ni ions of 5.0 × 10 16 ions/cm 2 . In particular, the AgNi alloy NPs with dual absorption peaks centered at 406 nm and 563 nm have been formed after 600 °C annealing in Ar atmosphere. However, at a low fluence of 1.0 × 10 16 ions/cm 2 , only small increase of the local Ag concentration than the Ag ions singly implanted sample can be observed. At a high fluence of 1.0 × 10 17 ions/cm 2 , lots Ag atoms are trapped close to the surface, which result in heavy sputtering loss of Ag atoms and the sublimation of Ag atoms after 600 °C annealing.

  14. The Health and Safety Executive's approval scheme for dosimetry services under the Ionising Radiations Regulations 1985

    International Nuclear Information System (INIS)

    Barrett, J.A.; Gill, J.R.; Gray, R.C.; Turton, D.; Young, T.O.

    1989-01-01

    The legal background to dosimetry for workers is described with a structured approach to ensuring that this dosimetry meets certain minimum standards in Great Britain. Some of the advantages and disadvantages of obtaining uniformity whilst maintaining flexibility are summarised. The approval process described places emphasis on the quality assurance controls to be put into practice by dosimetry services. (author)

  15. Study on the thermoluminescent properties of K2YF5 and K2GdF5 crystals doped with optically active trivalent ions for gamma and neutrons dosimetry

    International Nuclear Information System (INIS)

    Silva, Edna Carla da

    2008-01-01

    In this work, the thermoluminescent (TL) properties of both double potassium yttrium fluoride (K 2 YF 5 ) and double potassium gadolinium fluoride (K 2 GdF 5 ) crystals doped with optically active rare earth ions were investigated from the point of view of gamma and neutron dosimetry. Crystalline platelets with thickness of about 1 mm, synthesized under hydrothermal conditions, were irradiated in order to study TL sensitivity, as well as dose and energy response, reproducibility and fading, in terms of Ce 3+ , Tb 3+ , Dy 3+ , e Pr 3+ concentrations. The K 2 YF 5 crystals doped with 1.0 at por cent Dy 3+ have been found to have an excellent linear TL response to X and gamma photons, in the range of 0.01 to 10 mGy. The TL output is comparable to that of CaS0 4 :Mn dosemeters. The main peak at 130 deg C has been found to have a TL response for 41.1 keV X-ray energy 32 times higher than that for 662 keV gamma rays. This fact points out that the K 2 Y 0.99 Dy 0.01 F 5 crystals have great potential for X-rays diagnostic and/or industrial radiography. On the other hand, the K 2 GdF 5 crystals doped with 5.0 at por cent Dy 3+ have been found to have the better TL response for gamma and fast neutron radiation, among the dopants studied. For gamma fields the TL response was linear for doses ranging from 0.1 to 200 mGy. The TL peak around 200 deg C can be deconvoluted into four individual peaks, all of them with linear behavior. For fast neutron radiation produced by an 241 Am B e source, the TL responses for doses ranging from 0.6 to 12 mSv were also linear and comparable to that of commercial TLD-600, irradiated at same conditions. The TL emission due to neutrons was in the high temperature range, above 200 deg C. These results points out that K 2 Gd 0.95 Dy 0.05 F 5 crystals are good candidates for use in neutron dosimetry applications. (author)

  16. Thermoluminescent properties of ZrO2:Mn for UV light dosimetry

    International Nuclear Information System (INIS)

    Rivera M, T.; Azorin N, J.; Falcony G, C.; Martinez, E.; Garcia, M.

    1999-01-01

    The main source of ultraviolet light (UV) to whom is exposed the population is the one coming from the Sun, although exist some artificial sources too. The UV light can be classified in UV A (315-400)nm, in UV B (180-315) nm and UV C (100-180) nm. In this work are presented the results studying in the thermoluminescent characteristics of ZrO 2 : Mn for the UV dosimetry. The studied dosimetric characteristics were: concentration effect of the doping material, erased thermal treatment, posterior thermal treatment to the irradiation, Tl curve, response in function to the wavelength, response in function to the dose and reproducibility. Finally, presenting results highly promisers for the UV light dosimetry. (Author)

  17. Absorption and fluorescence properties of chromophoric dissolved organic matter: implications for the monitoring of water quality in a large subtropical reservoir.

    Science.gov (United States)

    Liu, Xiaohan; Zhang, Yunlin; Shi, Kun; Zhu, Guangwei; Xu, Hai; Zhu, Mengyuan

    2014-12-01

    The development of techniques for real-time monitoring of water quality is of great importance for effectively managing inland water resources. In this study, we first analyzed the absorption and fluorescence properties in a large subtropical reservoir and then used a chromophoric dissolved organic matter (CDOM) fluorescence monitoring sensor to predict several water quality parameters including the total nitrogen (TN), total phosphorus (TP), chemical oxygen demand (COD), dissolved organic carbon (DOC), and CDOM fluorescence parallel factor analysis (PARAFAC) components in the reservoir. The CDOM absorption coefficient at 254 nm (a(254)), the humic-like component (C1), and the tryptophan-like component (C3) decreased significantly along a gradient from the northwest to the lake center, northeast, southwest, and southeast region in the reservoir. However, no significant spatial difference was found for the tyrosine-like component (C2), which contributed only four marked peaks. A highly significant linear correlation was found between the a(254) and CDOM concentration measured using the CDOM fluorescence sensor (r(2) = 0.865, n = 76, p CDOM concentrations could act as a proxy for the CDOM absorption coefficient measured in the laboratory. Significant correlations were also found between the CDOM concentration and TN, TP, COD, DOC, and the maximum fluorescence intensity of C1, suggesting that the real-time monitoring of CDOM concentrations could be used to predict these water quality parameters and trace the humic-like fluorescence substance in clear aquatic ecosystems with DOC CDOM fluorescence sensor is a useful tool for on-line water quality monitoring if the empirical relationship between the CDOM concentration measured using the CDOM fluorescence sensor and the water quality parameters is calibrated and validated.

  18. Seasonal variation and light absorption property of carbonaceous aerosol in a typical glacier region of the southeastern Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    H. Niu

    2018-05-01

    Full Text Available Deposition and accumulation of light-absorbing carbonaceous aerosol on glacier surfaces can alter the energy balance of glaciers. In this study, 2 years (December 2014 to December 2016 of continuous observations of carbonaceous aerosols in the glacierized region of the Mt. Yulong and Ganhaizi (GHZ basin are analyzed. The average elemental carbon (EC and organic carbon (OC concentrations were 1.51±0.93 and 2.57±1.32 µg m−3, respectively. Although the annual mean OC ∕ EC ratio was 2.45±1.96, monthly mean EC concentrations during the post-monsoon season were even higher than OC in the high altitudes (approximately 5000 m a. s. l.  of Mt. Yulong. Strong photochemical reactions and local tourism activities were likely the main factors inducing high OC ∕ EC ratios in the Mt. Yulong region during the monsoon season. The mean mass absorption efficiency (MAE of EC, measured for the first time in Mt. Yulong, at 632 nm with a thermal-optical carbon analyzer using the filter-based method, was 6.82±0.73 m2 g−1, comparable with the results from other studies. Strong seasonal and spatial variations of EC MAE were largely related to the OC abundance. Source attribution analysis using a global aerosol–climate model, equipped with a black carbon (BC source tagging technique, suggests that East Asia emissions, including local sources, have the dominant contribution (over 50 % to annual mean near-surface BC in the Mt. Yulong area. There is also a strong seasonal variation in the regional source apportionment. South Asia has the largest contribution to near-surface BC during the pre-monsoon season, while East Asia dominates the monsoon season and post-monsoon season. Results in this study have great implications for accurately evaluating the influences of carbonaceous matter on glacial melting and water resource supply in glacierization areas.

  19. Seasonal variation and light absorption property of carbonaceous aerosol in a typical glacieri region of the southeastern Tibetan Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Hewen; Kang, Shichang; Wang, Hailong; Zhang, Rudong; Lu, Xixi; Qian, Yun; Paudyal, Rukumesh; Wang, Shijin; Shi, Xiaofei; Yan, Xingguo

    2018-05-07

    Deposition and accumulation of light-absorbing carbonaceous aerosol on glacier surfaces can alter the energy balance of glaciers. In this study, 2 years (December 2014 to December 2016) of continuous observations of carbonaceous aerosols in the glacierized region of the Mt. Yulong and Ganhaizi (GHZ) basin are analyzed. The average elemental carbon (EC) and organic carbon (OC) concentrations were 1.51±0.93 and 2.57±1.32 µg m−3, respectively. Although the annual mean OC ∕ EC ratio was 2.45±1.96, monthly mean EC concentrations during the post-monsoon season were even higher than OC in the high altitudes (approximately 5000 m a. s. l. ) of Mt. Yulong. Strong photochemical reactions and local tourism activities were likely the main factors inducing high OC ∕ EC ratios in the Mt. Yulong region during the monsoon season. The mean mass absorption efficiency (MAE) of EC, measured for the first time in Mt. Yulong, at 632 nm with a thermal-optical carbon analyzer using the filter-based method, was 6.82±0.73 m2 g−1, comparable with the results from other studies. Strong seasonal and spatial variations of EC MAE were largely related to the OC abundance. Source attribution analysis using a global aerosol–climate model, equipped with a black carbon (BC) source tagging technique, suggests that East Asia emissions, including local sources, have the dominant contribution (over 50 %) to annual mean near-surface BC in the Mt. Yulong area. There is also a strong seasonal variation in the regional source apportionment. South Asia has the largest contribution to near-surface BC during the pre-monsoon season, while East Asia dominates the monsoon season and post-monsoon season. Results in this study have great implications for accurately evaluating the influences of carbonaceous matter on glacial melting and water resource supply in glacierization areas.

  20. Improvements in the Tl dosimetry for Radiotherapy

    International Nuclear Information System (INIS)

    Bustos, S.; Velez, G.; Rubio, M.

    1998-01-01

    The thermoluminescent dosimetry (TLD) in vivo has been demonstrated to be one of the most reliable for the control of radiotherapeutic treatments, but the delay in the response is the main disadvantage in its applicability. In this work are presented important improvements and it is demonstrated that maintaining the accuracy and reliability of the technique, it is possible to accelerate the response times at a few hours. To realize this work is utilized a lecturer Harshaw 4000, dosemeters LiF-TLD-100 chips (3.1 x 3.1 x 0.89 mm 3 ) and rods (1 x 1 x 6 mm 3 ). With the implementation of a glow curve analysis program developed in CIEMAT, its obtained a Tl peaks separation in such manner rapid and accurate, by that the thermal treatment of dosemeters may be reduced at one unique annealing pre-irradiation for 1 hr at 400 Centigrade. It is realized a periodical and individual calibration of the TLD and a study of the factors which influencing the ratio Tl signal-dose as linearity, correction by energy, directional response and pride of Tl signal. the results of this study are introducing in a calculation list specially designed and which allows to obtain absorbed dose by TLD starting of the dates (dosimetric peaks area) which appear of the glow curves analysis. The dose is obtained with an accuracy less than 5 %. The dosemeters already irradiated (in vivo) are analysed and informed in only four hours, allowing a greater control of the treatment and a correction of the possible errors for the next session, still in bi fractional treatments. The method implemented results thus accurate, rapid and reliable. (Author)

  1. Electromagnetic wave absorption properties of composites with micro-sized magnetic particles dispersed in amorphous carbon

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bin Peng [Research Center of Carbon Fiber, Key Laboratory for Liquid–Solid Structural Evolution and Processing of Materials of Ministry of Education, Shandong University, Jinan 250061 (China); Tianjin Binhai New Area Finance Bureau, Tianjin 300450 (China); Wang, Cheng Guo, E-mail: sduwangchg@gmail.com [Research Center of Carbon Fiber, Key Laboratory for Liquid–Solid Structural Evolution and Processing of Materials of Ministry of Education, Shandong University, Jinan 250061 (China); Wang, Wen [Norinco Group China North Material Science and Engineering Technology Group Corporation, Jinan 250031 (China); Yu, Mei Jie; Gao, Rui; Chen, Yang; Xiang Wang, Yan [Research Center of Carbon Fiber, Key Laboratory for Liquid–Solid Structural Evolution and Processing of Materials of Ministry of Education, Shandong University, Jinan 250061 (China)

    2014-09-01

    Composites with micro-sized magnetic particles dispersed in amorphous carbon were fabricated conveniently and economically by carbonizing polyacrylonitrile (PAN) fibers mixed with micro-sized iron particles under different temperatures. The composites were characterized by X-ray diffraction (XRD) and scanning electric microscope (SEM). The electromagnetic (EM) properties were measured by a vector network analyzer in the frequency range of 2–18 GHz based on which analog computations of EM wave absorption properties were carried out. The influences of temperature on phase composition and EM wave absorption properties were also investigated, indicating that the composites had good electromagnetic absorption properties with both electrical loss and magnetic loss. Effective reflection loss (RL<−10 dB) was observed in a large frequency range of 7.5–18 GHz with the absorber thickness of 2.0–3.0 mm for the paraffin samples with composite powders heated up to 750 °C and the minimum absorption peak around −40 dB appeared at approximately 10 GHz with matching thickness of 2.0 mm for the paraffin sample with composite powders heated up to 800 °C. - Highlights: • High-performance electromagnetic wave absorption materials were fabricated conveniently and economically. • The materials are composites with micro-sized magnetic particles dispersed in porous amorphous carbon. • The influences of temperature on phase composition and electromagnetic wave absorption properties were investigated. • The composites heated up to 750 °C and 800 °C had good electromagnetic wave absorption property.

  2. Microwave absorption properties of carbon nanocoils coated with highly controlled magnetic materials by atomic layer deposition.

    Science.gov (United States)

    Wang, Guizhen; Gao, Zhe; Tang, Shiwei; Chen, Chaoqiu; Duan, Feifei; Zhao, Shichao; Lin, Shiwei; Feng, Yuhong; Zhou, Lei; Qin, Yong

    2012-12-21

    In this work, atomic layer deposition is applied to coat carbon nanocoils with magnetic Fe(3)O(4) or Ni. The coatings have a uniform and highly controlled thickness. The coated nanocoils with coaxial multilayer nanostructures exhibit remarkably improved microwave absorption properties compared to the pristine carbon nanocoils. The enhanced absorption ability arises from the efficient complementarity between complex permittivity and permeability, chiral morphology, and multilayer structure of the products. This method can be extended to exploit other composite materials benefiting from its convenient control of the impedance matching and combination of dielectric-magnetic multiple loss mechanisms for microwave absorption applications.

  3. Review of radiation dosimetry research at the University of Wisconsin during 1961-1982

    International Nuclear Information System (INIS)

    Cameron, J.R.; Moran, P.R.; Attix, F.H.

    1982-01-01

    The report provides a comprehensive review of the overall activities in this program since 1961. Research areas have included the development and use of lithium fluoride for thermoluminescent dosimetry, solid state neutron dosimetry, and ionization chamber research

  4. Radiation dosimetry properties of smart-phone CMOS sensors

    International Nuclear Information System (INIS)

    Van Hoey, Olivier; Salavrakos, Alexia; Marques, Antonio; Nagao, Alexandre; Vanhavere, Filip; Cauwels, Vanessa; Nascimento, Luana F.; Willems, Ruben

    2016-01-01

    During the past years, several smart-phone applications have been developed for radiation detection. These applications measure radiation using the smart-phone camera complementary metal-oxide-semiconductor sensor. They are potentially useful for data collection and personal dose assessment in case of a radiological incident. However, it is important to assess these applications. Six applications were tested by means of irradiations with calibrated X-ray and gamma sources. It was shown that the measurement stabilises only after at least 10-25 min. All applications exhibited a flat dose rate response in the studied ambient dose equivalent range from 2 to 1000 μSv h -1 . Most applications significantly over- or underestimate the dose rate or are not calibrated in terms of dose rate. A considerable energy dependence was observed below 100 keV but not for the higher energy range more relevant for incident scenarios. Photon impact angle variation gave a measured signal variation of only about 10 %. (authors)

  5. The reliability of the systems of personal dosimetry

    International Nuclear Information System (INIS)

    Gullberg, O.; Lindborg, L.

    1982-01-01

    The dosimeters of companies and institutions have been irradiated at various energy and dose equivalent levels. Systematic and coincident errors in measurement are presented. The results show that relatively large systematic errors can be made by both the thermoluminescent and film systems. Various techniques to judging the quality of the dosimetry are discussed. (G.B.)

  6. Synthesis and luminescence properties of KSrPO{sub 4}:Eu{sup 2+} phosphor for radiation dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Palan, C. B., E-mail: chetanpalan27@yahoo.in [Department of Physics, Sant Gadge Baba Amravati University, Amravati-444602 (India); Bajaj, N. S. [Toshniwal ACS College, Sengaon, Hingoli-431542 (India); Omanwar, S. K.

    2016-05-06

    The KSrPO{sub 4}:Eu phosphor was synthesized via solid state method. The structural and morphological characterizations were done through XRD (X-ray diffraction) and SEM (Scanning Electronic Microscope). Additionally, the photoluminescence (PL), thermoluminescence (TL) and optically Stimulated luminescence (OSL) properties of powder KSrPO{sub 4}:Eu were studied. The PL spectra show blue emission under near UV excitation. It was advocated that KSrPO{sub 4}:Eu phosphor not only show OSL sensitivity (0.47 times) but also gives faster decay in OSL signals than that of Al{sub 2}O{sub 3}:C (BARC) phosphor. The TL glow curve consist of two shoulder peaks and the kinetics parameters such as activation energy and frequency factors were determined by using peak shape method and also photoionization cross-sections of prepared phosphor was calculated. The radiation dosimetry properties such as minimum detectable dose (MDD), dose response and reusability were reported.

  7. Accidental and retrospective dosimetry using TL method

    International Nuclear Information System (INIS)

    Mesterházy, D.; Osvay, M.; Kovács, A.; Kelemen, A.

    2012-01-01

    Retrospective dosimetry is one of the most important tools of accidental dosimetry for dose estimation when dose measurement was not planned. In the affected area many objects can be applied as natural dosimeters. The paper discusses our recent investigations on various electronic components and common salt (NaCl) having useful thermoluminescence (TL) properties. Among materials investigated the electronic components of cell phones seem promising for retrospective dosimetry purposes, having high TL responses, proper glow curve peaks and the intensity of TL peaks vs. gamma dose received provided nearly linear response in the dose range of 10 mGy–1.5 Gy. - Highlights: ► Electronic components and common salt were investigated for accidental and retrospective dosimetry. ► SMD resistors seem promising for retrospective dosimetry purposes. ► Table salt can be used effectively for accidental dosimetry purposes, as well.

  8. Profiling biopharmaceutical deciding properties of absorption of lansoprazole enteric-coated tablets using gastrointestinal simulation technology.

    Science.gov (United States)

    Wu, Chunnuan; Sun, Le; Sun, Jin; Yang, Yajun; Ren, Congcong; Ai, Xiaoyu; Lian, He; He, Zhonggui

    2013-09-10

    The aim of the present study was to correlate in vitro properties of drug formulation to its in vivo performance, and to elucidate the deciding properties of oral absorption. Gastrointestinal simulation technology (GST) was used to simulate the in vivo plasma concentration-time curve and was implemented by GastroPlus™ software. Lansoprazole, a typical BCS class II drug, was chosen as a model drug. Firstly, physicochemical and pharmacokinetic parameters of lansoprazole were determined or collected from literature to construct the model. Validation of the developed model was performed by comparison of the predicted and the experimental plasma concentration data. We found that the predicted curve was in a good agreement with the experimental data. Then, parameter sensitivity analysis (PSA) was performed to find the key parameters of oral absorption. The absorption was particularly sensitive to dose, solubility and particle size for lansoprazole enteric-coated tablets. With a single dose of 30 mg and the solubility of 0.04 mg/ml, the absorption was complete. A good absorption could be achieved with lansoprazole particle radius down to about 25 μm. In summary, GST is a useful tool for profiling biopharmaceutical deciding properties of absorption of lansoprazole enteric-coated tablets and guiding the formulation optimization. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  9. The dielectric properties of human pineal gland tissue and RF absorption due to wireless communication devices in the frequency range 400-1850 MHz

    International Nuclear Information System (INIS)

    Schmid, Gernot; Ueberbacher, Richard; Samaras, Theodoros; Tschabitscher, Manfred; Mazal, Peter R

    2007-01-01

    In order to enable a detailed analysis of radio frequency (RF) absorption in the human pineal gland, the dielectric properties of a sample of 20 freshly removed pineal glands were measured less than 20 h after death. Furthermore, a corresponding high resolution numerical model of the brain region surrounding the pineal gland was developed, based on a real human tissue sample. After inserting this model into a commercially available numerical head model, FDTD-based computations for exposure scenarios with generic models of handheld devices operated close to the head in the frequency range 400-1850 MHz were carried out. For typical output power values of real handheld mobile communication devices, the obtained results showed only very small amounts of absorbed RF power in the pineal gland when compared to SAR limits according to international safety standards. The highest absorption was found for the 400 MHz irradiation. In this case the RF power absorbed inside the pineal gland (organ mass 96 mg) was as low as 11 μW, when considering a device of 500 mW output power operated close to the ear. For typical mobile phone frequencies (900 MHz and 1850 MHz) and output power values (250 mW and 125 mW) the corresponding values of absorbed RF power in the pineal gland were found to be lower by a factor of 4.2 and 36, respectively. These results indicate that temperature-related biologically relevant effects on the pineal gland induced by the RF emissions of typical handheld mobile communication devices are unlikely

  10. Dosimetry practices at the Radiation Technology Centre (Ghana)

    International Nuclear Information System (INIS)

    Emi-Reynolds, G.; Banini, G.K.; Ennison, I.

    1997-01-01

    Dosimetry practices undertaken to support research and pilot scale gamma irradiation activities at the Radiation Technology Centre of the Ghana Atomic Energy Commission are presented. The Fricke dosemeter was used for calibrating the gamma field of the gammacell-220. The Fricke system and the gammacell-220 were then used to calibrate the ethanol chlorobenzene (ECB) dosemeter. The Fricke and ECB dosemeter systems have become routine dosemeters at the centre. Dosimetry work has covered a wide range of research specimens and pilot scale products to establish the relevant irradiation protocol and parameters for routine treatment. These include yams, pineapple explants, blood for feeding tsetseflies, cocoa bud wood and cassava sticks. Pilot scale dosimetry studies on maize, medical devices like intravenous infusion sets and surgical gauze have also been completed. The results and observations made on some of these products are reported. (author). 4 refs., 5 figs

  11. The work of the 'Irradiation Damage' sub-group of the EURATOM Working Group on Research Reactor Dosimetry

    International Nuclear Information System (INIS)

    Genthon, J.P.

    1975-01-01

    The EURATOM Working Group on Reactor Dosimetry is investigating the problems of the dosimetry of radiation damage experiments. Papers have been published on the dosimetry of graphite and irradiation of metals: the model chosen, the quantities employed to express the fluences, numerical values, measurements, and measurement techniques. The ensuing work of the EURATOM Working Group of Reactor Dosimetry in these areas will deal with the measurement methods required for the dosimetry of radiation damage. (Auth.)

  12. Dosimetry-based treatment planning for molecular radiotherapy: a summary of the 2017 report from the Internal Dosimetry Task Force

    Directory of Open Access Journals (Sweden)

    Caroline Stokke

    2017-11-01

    Full Text Available Abstract Background The European directive on basic safety standards (Council directive 2013/59 Euratom mandates dosimetry-based treatment planning for radiopharmaceutical therapies. The directive comes into operation February 2018, and the aim of a report produced by the Internal Dosimetry Task Force of the European Association of Nuclear Medicine is to address this aspect of the directive. A summary of the report is presented. Results A brief review of five of the most common therapy procedures is included in the current text, focused on the potential to perform patient-specific dosimetry. In the full report, 11 different therapeutic procedures are included, allowing additional considerations of effectiveness, references to specific literature on quantitative imaging and dosimetry, and existing evidence for absorbed dose-effect correlations for each treatment. Individualized treatment planning with tracer diagnostics and verification of the absorbed doses delivered following therapy is found to be scientifically feasible for almost all procedures investigated, using quantitative imaging and/or external monitoring. Translation of this directive into clinical practice will have significant implications for resource requirements. Conclusions Molecular radiotherapy is undergoing a significant expansion, and the groundwork for dosimetry-based treatment planning is already in place. The mandated individualization is likely to improve the effectiveness of the treatments, although must be adequately resourced.

  13. Realising the European network of bio-dosimetry (RENEB)

    International Nuclear Information System (INIS)

    Kulka, U.; Ainsbury, L.; Atkinson, M.; Barquinero, J. F.; Barrios, L.; Beinke, C.; Bognar, G.; Cucu, A.; Darroudi, F.; Fattibene, P.; Gil, O.; Gregoire, E.; Hadjidekova, V.; Haghdoost, S.; Herranz, R.; Jaworska, A.; Lindholm, C.; Mkacher, R.; Moertl, S.; Montoro, A.; Moquet, J.; Moreno, M.; Ogbazghi, A.; Oestreicher, U.; Palitti, F.; Pantelias, G.; Popescu, I.; Prieto, M. J.; Romm, H.; Rothkamm, K.; Sabatier, L.; Sommer, S.; Terzoudi, G.; Testa, A.; Thierens, H.; Trompier, F.; Turai, I.; Vandersickel, V.; Vaz, P.; Voisin, P.; Vral, A.; Ugletveit, F.; Woda, C.; Wojcik, A.

    2012-01-01

    In Europe, a network for biological dosimetry has been created to strengthen the emergency preparedness and response capabilities in case of a large-scale nuclear accident or radiological emergency. Through the RENEB (Realising the European Network of bio-dosimetry) project, 23 experienced laboratories from 16 European countries will establish a sustainable network for rapid, comprehensive and standardised bio-dosimetry provision that would be urgently required in an emergency situation on European ground. The foundation of the network is formed by five main pillars: (1) the ad hoc operational basis, (2) a basis of future developments, (3) an effective quality-management system, (4) arrangements to guarantee long-term sustainability and (5) awareness of the existence of RENEB. RENEB will thus provide a mechanism for quick, efficient and reliable support within the European radiation emergency management. The scientific basis of RENEB will concurrently contribute to increased safety in the field of radiation protection. (authors)

  14. Mixed field dosimetry with the twin chamber technique

    International Nuclear Information System (INIS)

    Burger, G.; Maier, E.

    1974-04-01

    For the separate dosimetry of the neutron- and gamma-component in a mixed beam it is principally possible to use two ionization chambers with different ratios of neutron- to gamma sensitivity. Several authors proposed for this purpose the use of a homogenious TE-chamber filled with the TE-gas and of a carbon-chamber filled with CO 2 -gas. This chamber combination is also commercially available in several countries. The chambers are normally equipped with a continuous gas-flow provision and with a waterproof-housing for the use within liquid phantoms. The application of such chambers for mixed field dosimetry in the intercomparison project of the ICRU at the RARAF-facility in Brookhaven (International Neutron Dosimetry Intercomparison - INDI) is described. (orig./HP) [de

  15. Status report of the ESR/alanine project of the IAEA Dosimetry Laboratory

    International Nuclear Information System (INIS)

    Girzikowsky, R.

    1990-01-01

    The main tasks of the Dosimetry Laboratory of the IAEA are in the field of therapy-level dosimetry. Other dose ranges, i.e. protection-level standardization and calibration, are partly covered, too. On high-dose level the laboratory has been offering a Fricke-dosimetry service to Member States on request since 1965. In 1985 the Dosimetry Section has initiated an International Dose Assurance Service (IDAS). This service is an important part of the Agency's high-dose standardization programme and is based on Electron-Spin-Resonance (ESR) analysis of radiation-induced free radicals in alanine. This ESR/alanine dosimetry system was initially developed for high-dose application by GSF/Munich as the Agency's outside contractor. Although efforts were undertaken to equip the Agency Laboratory with an ESR analyzer since 1984, the purchase of an adequate unit was postponed until the end of 1988. From the date of establishment of the IDAS programme until today, the handling of all technical aspects, i.e. dosimeter production and evaluation was and is carried out by GSP/Munich under IAEA contract. As mentioned above, the IAEA Dosimetry Laboratory is in possession of its own ESR analyzer since December 1988. It was then installed in May 1989. Only one staff member of the laboratory was assigned to this project. He made himself acquainted with the analyzer, the measuring technique, and the application of alanine as dosimeter material. The ESR spectrometric analyzer is a CW ESR type ESP 300 manufactured by Bruker GmbH/FRG. It consists of a 9''/2,7 kW magnet, an X-band microwave bridge, a field regulator unit, a signal channel unit and a data system ESP 1620 based on the 68020 CPU. The probe material selected for measurement of concentration of radiation-induced free radicals is L-Alanine. This amino acid is a suitable material for transfer dosimeters due to its properties, i.e. wide sensitivity range (10 Gy to 100 kGy), energy independence for high-energy photons and electron

  16. Cheminformatics Modeling of Amine Solutions for Assessing their CO2 Absorption Properties.

    Science.gov (United States)

    Kuenemann, Melaine A; Fourches, Denis

    2017-07-01

    As stricter regulations on CO 2 emissions are adopted worldwide, identifying efficient chemical processes to capture and recycle CO 2 is of critical importance for industry. The most common process known as amine scrubbing suffers from the lack of available amine solutions capable of capturing CO 2 efficiently. Tertiary amines characterized by low heats of reaction are considered good candidates but their absorption properties can significantly differ from one analogue to another despite high structural similarity. Herein, after collecting and curating experimental data from the literature, we have built a modeling set of 41 amine structures with their absorption properties. Then we analyzed their chemical composition using molecular descriptors and non-supervised clustering. Furthermore, we developed a series of quantitative structure-property relationships (QSPR) to assess amines' CO 2 absorption properties from their structural characteristics. These models afforded reasonable prediction performances (e. g., Q 2 LOO =0.63 for CO 2 absorption amount) even though they are solely based on 2D chemical descriptors and individual machine learning techniques (random forest and neural network). Overall, we believe the chemical analysis and the series of QSPR models presented in this proof-of-concept study represent new knowledge and innovative tools that could be very useful for screening and prioritizing hypothetical amines to be synthesized and tested experimentally for their CO 2 absorption properties. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Advantages and disadvantages of luminescence dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Olko, Pawel, E-mail: Pawel.Olko@ifj.edu.p [Institute of Nuclear Physics Polish Academy of Science (IFJ PAN), Krakow (Poland)

    2010-03-15

    Owing to their excellent dosimetric properties, luminescence detectors of ionizing radiation are now extensively applied in individual dosimetry services. The most frequently used personal dosemeters are based on Optically Stimulated Luminescence (OSL), radiophotoluminescence (RPL) or thermoluminescence (TL). Luminescence detectors have also found several applications in clinical dosimetry, especially around new radiation modalities in radiotherapy, such as Intensity Modulated Radiotherapy (IMRT) or ion beam radiotherapy. Requirements of luminescence detectors applied in individual and clinical dosimetry and some recent developments in luminescence of detectors and techniques leading to significant improvements of the functionality and accuracy of dosimetry systems are reviewed and discussed.

  18. A transferability study of the EPR-tooth-dosimetry technique

    International Nuclear Information System (INIS)

    Sholom, S.; Chumak, V.; Desrosiers, M.; Bouville, A.

    2006-01-01

    The transferability of a measurement protocol from one laboratory to another is an important feature of any mature, standardised protocol. The electron paramagnetic resonance (EPR)-tooth dosimetry technique that was developed in Scientific Center for Radiation Medicine, AMS (Ukraine) (SCRM) for routine dosimetry of Chernobyl liquidators has demonstrated consistent results in several inter-laboratory measurement comparisons. Transferability to the EPR dosimetry laboratory at the National Inst. of Standards and Technology (NIST) was examined. Several approaches were used to test the technique, including dose reconstruction of SCRM-NIST inter-comparison samples. The study has demonstrated full transferability of the technique and the possibility to reproduce results in a different laboratory environment. (authors)

  19. Personnel dosimetry methods introduced in the Czechoslovak national laboratories

    International Nuclear Information System (INIS)

    Trousil, J.; Singer, J.; Kokta, L.; Prouza, Z.

    1979-01-01

    Personnel dosimetry methods are described that were developed in the Institute for Research, Production and Application of Radioisotopes and that have been or will be introduced in the national personnel dosimetry service. In Czechoslovakia, workers exposed to a radiation risk are divided into two groups, according to the level of the risk. The criterion is the possibility of exceeding one tenth of the MPD. For the higher risk group, a complex dose meter is usually used for dosimetry of photon and beta radiation; it contains a film dose meter and a radiothermoluminescent (RTL) glass dose meter. The RTL glass dose meter also serves as an accident dose meter. For neutron dosimetry, a dose meter comprising a solid-state track detector in combination with fissionable foils has been introduced. For accident dosimetry, a silicon diode of Czechoslovak production is used. For the lower risk group, only the introduction of an RTL dose meter is foreseen. There will be a three month control period; for neutron dosimetry, the track detector in combination with fissionable foils is retained. For measurements of hand doses, a themoluminescent ring dose meter has been introduced. The dose meters are described, giving information on the types of detectors employed, measurement techniques and descriptions of the basic characteristics of the instruments, their basic dosimetric parameters and the dose and energy ranges which can be measured. The results of international comparisons are presented; these have served to confirm the measurement precision. In conclusion, some questions of dose-meter calibration are summarized, and the problems of dose measurement in mixed fields of neutrons and gamma rays are discussed. (author)

  20. Fe3O4 nanoparticles decorated MWCNTs @ C ferrite nanocomposites and their enhanced microwave absorption properties

    Science.gov (United States)

    Zhang, Kaichuang; Gao, Xinbao; Zhang, Qian; Chen, Hao; Chen, Xuefang

    2018-04-01

    Fe3O4 nanoparticles decorated MWCNTs @ C ferrite nanocomposites were synthesized using a co-precipitation method and a calcination process. As one kind absorbing material, we researched the electromagnetic absorption properties of the composites that were mixed with a filler loading of 80 wt% paraffin. In addition, we studied the influence of the magnetic nanoparticle content on the absorbing properties. The results showed that the frequency corresponding to the maximum absorptions shifted to lower frequency when the magnetic nanoparticles content increased. The Fe3O4 nanoparticles decorated MWCNTs @ C ferrite nanocomposites with approximately 60% Fe3O4 nanoparticles showed the best electromagnetic absorption properties. The maximum reflection loss was -52.47 dB with a thickness of 2.0 mm at 10.4 GHz.

  1. Radiation protection dosimetry in medicine - Report of the working group n.9 of the European radiation dosimetry group (EURADOS) - coordinated network for radiation dosimetry (CONRAD - contract EC N) fp6-12684; Dosimetrie pour la radioprotection en milieu medical - rapport du groupe de travail n. 9 du European radiation dosimetry group (EURADOS) - coordinated netword for radiation dosimetry (CONRAD - contrat CE fp6-12684)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    This report present the results achieved within the frame of the work the WP 7 (Radiation Protection Dosimetry of Medical Staff) of the coordination action CONRAD (Coordinated Network for Radiation Dosimetry) funded through the 6. EU Framework Program. This action was coordinated by EURADOS (European Radiation Dosimetry Group). EURADOS is an organization founded in 1981 to advance the scientific understanding and the technical development of the dosimetry of ionising radiation in the fields of radiation protection, radiobiology, radiation therapy and medical diagnosis by promoting collaboration between European laboratories. WP7 coordinates and promotes European research for the assessment of occupational exposures to staff in therapeutic and diagnostic radiology workplaces. Research is coordinated through sub-groups covering three specific areas: 1. Extremity dosimetry in nuclear medicine and interventional radiology: this sub-group coordinates investigations in the specific fields of the hospitals and studies of doses to different parts of the hands, arms, legs and feet; 2. Practice of double dosimetry: this sub-group reviews and evaluates the different methods and algorithms for the use of dosemeters placed above and below lead aprons in large exposure during interventional radiology procedures, especially to determine effective doses to cardiologists during cardiac catheterization; and 3. Use of electronic personal dosemeters in interventional radiology: this sub-group coordinates investigations in laboratories and hospitals, and intercomparisons with passive dosemeters with the aim to enable the formulation of standards. (authors)

  2. Neutron dosimetry: problems, solutions, prospects and the role of trace detectors

    International Nuclear Information System (INIS)

    Fernandez, F.

    2009-10-01

    It is present in schematic way, the origin of the neutrons; their interaction with matter, until its application in the field of dosimetry. It describes some measuring instruments based on thermoluminescence dosimetry, some activation detectors and trace detectors. Finally, it summarizes the work in neutron dosimetry have been carried out at the Autonomous University of Barcelona. (Author)

  3. Status of the dosimetry file for ENDF/B-V

    International Nuclear Information System (INIS)

    Magurno, B.A.

    1979-01-01

    Since the new Dosimetry File will not be ready for distrubution until February-March, 1979, this presentation is submitted as a progress report where the schedule for release and dissemination of the library was reported. The dates of release and distribution were predicated on the use of pre-determined standards for use with the new Dosimetry File. Subsequently, one of the most important standards, i.e. 235 U (n,f) has been re-evaluated, causing the delay that is responsible for the above mentioned release date

  4. Thermoluminescence and radioluminescence properties of tissue equivalent Cu-doped Li2B4O7 for radiation dosimetry

    International Nuclear Information System (INIS)

    Cruz Z, E.; Furetta, C.; Marcazzo, J.; Santiago, M.; Guarneros, C.; Pacio, M.; Palomino, R.

    2015-10-01

    Thermoluminescence (Tl) and radioluminescence (Rl) properties of lithium tetraborate (Li 2 B 4 O 7 ) doped with different concentration of copper (0.25, 0.5, 1 wt %) under gamma and beta irradiation has been investigated. The feasibility of using this borate in radiation dosimetry at low doses has been evaluated. Tissue equivalent Li 2 B 4 O 7 was prepared by solid state reaction using mixing stoichiometric compositions of lithium carbonate (Li 2 CO 3 ) and boric acid (H 3 BO 3 ) and a solution of CuCl 2 as dopant. The glow curve, of the most efficient copper doped borate (Li 2 B 4 O 7 :Cu 0.5 wt %), shows a main stable peak centered at 225 degrees C and a second low temperature peak centered at 80 degrees C. The low temperature peak disappears completely after 24 hours of storage in darkness and at room temperature or after an annealing at 120 degrees C for 10 seconds. The main peak of the Li 2 B 4 O 7 :Cu remains constant. The Tl response of Li 2 B 4 O 7 :Cu shows good linearity in the analyzed dose range. The stability and repeatability of Rl signals of the borate have been studied and the Li 2 B 4 O 7 :Cu (0.5 wt %) shown the higher Rl emission and a stable and repetitive response. Results show that Li 2 B 4 O 7 :Cu has prospects to be used in gamma and beta radiation dosimetry. (Author)

  5. Dosimetry through the Secondary Laboratory of Dosimetric Calibration of Mexico

    International Nuclear Information System (INIS)

    Tovar M, V.M.; Alvarez R, J.T.; Medina O, V.P.; Vergara M, F.; Anaya M, R.; Cejudo A, J.; Salinas L, B.

    2004-01-01

    In the beginnings of the sixty years an urgent necessity is presented mainly in the developing countries, of improving in important form the accuracy in the dosimetry of external faces in therapy of radiations (radiotherapy centers), mainly in the calibration of c linical dosemeters . In 1976 the International Atomic Energy Agency, (IAEA), and the World Health Organization, (WHO), they carried out a mutual agreement with regard to the establishment and operation of a net of Secondary Patron Laboratories of Dosimetry, (LSCD). The necessity to establish measure patterns in the field of the dosimetry of the ionizing radiations, is necessary, to have an accuracy but high in the dosimetry of the radiation beams in therapy which is highly dependent of the dose given to the tumor of those patient with cancer. Similar levels of accuracy are required in protection measures to the radiation with an acceptable smaller accuracy, however, when the personal dosemeters are used to determine the doses received by the individuals under work conditions, such mensurations in therapy of radiations and radiological protection will have traceability through a chain of comparisons to primary or national patterns. The traceability is necessary to assure the accuracy and acceptability of the dosimetric measures, as well as, the legal and economic implications. The traceability is also necessary in the dosimetry of high dose like in the sterilization of different products. The main function of the LSCD is to provide a service in metrology of ionizing radiations, maintaining the secondary or national patterns, which have a traceability to the International System of measures, which is based for if same in the comparison of patterns in the Primary Laboratories of Dosimetry (LPD) under the auspice of the International Office of Weights and Measure (BIPM). The secondary and national patterns in the LSCD constitute in Mexico, the national patterns of the magnitudes in the dosimetry of the

  6. The spatial resolution in dosimetry with normoxic polymer-gels investigated with the dose modulation transfer approach

    International Nuclear Information System (INIS)

    Bayreder, Christian; Schoen, Robert; Wieland, M.; Georg, Dietmar; Moser, Ewald; Berg, Andreas

    2008-01-01

    The verification of dose distributions with high dose gradients as appearing in brachytherapy or stereotactic radiotherapy for example, calls for dosimetric methods with sufficiently high spatial resolution. Polymer gels in combination with a MR or optical scanner as a readout device have the potential of performing the verification of a three-dimensional dose distribution within a single measurement. The purpose of this work is to investigate the spatial resolution achievable in MR-based polymer gel dosimetry. The authors show that dosimetry on a very small spatial scale (voxel size: 94x94x1000 μm 3 ) can be performed with normoxic polymer gels using parameter selective T2 imaging. In order to prove the spatial resolution obtained we are relying on the dose-modulation transfer function (DMTF) concept based on very fine dose modulations at half periods of 200 μm. Very fine periodic dose modulations of a 60 Co photon field were achieved by means of an absorption grid made of tungsten-carbide, specifically designed for quality control. The dose modulation in the polymer gel is compared with that of film dosimetry in one plane via the DMTF concept for general access to the spatial resolution of a dose imaging system. Additionally Monte Carlo simulations were performed and used for the calculation of the DMTF of both, the polymer gel and film dosimetry. The results obtained by film dosimetry agree well with those of Monte Carlo simulations, whereas polymer gel dosimetry overestimates the amplitude value of the fine dose modulations. The authors discuss possible reasons. The in-plane resolution achieved in this work competes with the spatial resolution of standard clinical film-scanner systems

  7. Fluorescence and absorption properties of chromophoric dissolved organic matter (CDOM in coastal surface waters of the northwestern Mediterranean Sea, influence of the Rhône River

    Directory of Open Access Journals (Sweden)

    J. Para

    2010-12-01

    Full Text Available Seawater samples were collected monthly in surface waters (2 and 5 m depths of the Bay of Marseilles (northwestern Mediterranean Sea; 5°17'30" E, 43°14'30" N during one year from November 2007 to December 2008 and studied for total organic carbon (TOC as well as chromophoric dissolved organic matter (CDOM optical properties (absorbance and fluorescence. The annual mean value of surface CDOM absorption coefficient at 350 nm [aCDOM(350] was very low (0.10 ± 0.02 m−1 in comparison to values usually found in coastal waters, and no significant seasonal trend in aCDOM(350 could be determined. By contrast, the spectral slope of CDOM absorption (SCDOM was significantly higher (0.023 ± 0.003 nm−1 in summer than in fall and winter periods (0.017 ± 0.002 nm−1, reflecting either CDOM photobleaching or production in surface waters during stratified sunny periods. The CDOM fluorescence, assessed through excitation emission matrices (EEMs, was dominated by protein-like component (peak T; 1.30–21.94 QSU and marine humic-like component (peak M; 0.55–5.82 QSU, while terrestrial humic-like fluorescence (peak C; 0.34–2.99 QSU remained very low. This reflected a dominance of relatively fresh material from biological origin within the CDOM fluorescent pool. At the end of summer, surface CDOM fluorescence was very low and strongly blue shifted, reinforcing the hypothesis of CDOM photobleaching. Our results suggested that unusual Rhône River plume eastward intrusion events might reach Marseilles Bay within 2–3 days and induce local phytoplankton blooms and subsequent fluorescent CDOM production (peaks M and T without adding terrestrial fluorescence signatures (peaks C and A. Besides Rhône River plumes, mixing events of the entire water column injected relative aged (peaks C and M CDOM from the bottom into the surface and thus appeared also as an important source

  8. Fluorescence and absorption properties of chromophoric dissolved organic matter (CDOM) in coastal surface waters of the northwestern Mediterranean Sea, influence of the Rhône River

    Science.gov (United States)

    Para, J.; Coble, P. G.; Charrière, B.; Tedetti, M.; Fontana, C.; Sempéré, R.

    2010-12-01

    Seawater samples were collected monthly in surface waters (2 and 5 m depths) of the Bay of Marseilles (northwestern Mediterranean Sea; 5°17'30" E, 43°14'30" N) during one year from November 2007 to December 2008 and studied for total organic carbon (TOC) as well as chromophoric dissolved organic matter (CDOM) optical properties (absorbance and fluorescence). The annual mean value of surface CDOM absorption coefficient at 350 nm [aCDOM(350)] was very low (0.10 ± 0.02 m-1) in comparison to values usually found in coastal waters, and no significant seasonal trend in aCDOM(350) could be determined. By contrast, the spectral slope of CDOM absorption (SCDOM) was significantly higher (0.023 ± 0.003 nm-1) in summer than in fall and winter periods (0.017 ± 0.002 nm-1), reflecting either CDOM photobleaching or production in surface waters during stratified sunny periods. The CDOM fluorescence, assessed through excitation emission matrices (EEMs), was dominated by protein-like component (peak T; 1.30-21.94 QSU) and marine humic-like component (peak M; 0.55-5.82 QSU), while terrestrial humic-like fluorescence (peak C; 0.34-2.99 QSU) remained very low. This reflected a dominance of relatively fresh material from biological origin within the CDOM fluorescent pool. At the end of summer, surface CDOM fluorescence was very low and strongly blue shifted, reinforcing the hypothesis of CDOM photobleaching. Our results suggested that unusual Rhône River plume eastward intrusion events might reach Marseilles Bay within 2-3 days and induce local phytoplankton blooms and subsequent fluorescent CDOM production (peaks M and T) without adding terrestrial fluorescence signatures (peaks C and A). Besides Rhône River plumes, mixing events of the entire water column injected relative aged (peaks C and M) CDOM from the bottom into the surface and thus appeared also as an important source of CDOM in surface waters of the Marseilles Bay. Therefore, the assessment of CDOM optical properties

  9. Reassessment of the atomic bomb radiation dosimetry for Hiroshima and Nagasaki. Dosimetry system 2002. DS02. Volume 1

    International Nuclear Information System (INIS)

    Young, Robert W.; Kerr, George D.

    2005-01-01

    The extensive efforts to review the dosimetry of the atomic-bomb survivors and formulate the new dosimetry system DS02 have been greatly welcomed by the Radiation Effects Research Foundation (RERF). This accomplishment is a fine tribute to the importance of the epidemiological studies being conducted at RERF. No other study is so informative of the effects of radiation on human health. The gracious participation in the RERF program by the atomic-bomb survivors allows us to contribute to the well being of these individuals, and the high quality of the data obtained allows the RERF results to feature so prominently in the formulation of international guidelines for radiation protection. Such a great effort to improve and substantiate the dosimetry would not otherwise have been justified. RERF greatly appreciates the independent work of the U.S. and Japanese Working Groups on the atomic-bomb dosimetry and the review by the Joint Senior Review Group of this overall effort. We are assured that unbiased development of the new dosimetry system will reflect well in its application in the RERF epidemiology study. The documentation included in this report will serve as reference for the many deliberations concluded. The title publications are divided into 2 volumes. This is the first volume. The 8 of the reports in each chapter are indexed individually. (J.P.N.)

  10. Reassessment of the atomic bomb radiation dosimetry for Hiroshima and Nagasaki. Dosimetry system 2002. DS02. Volume 2

    International Nuclear Information System (INIS)

    Young, Robert W.; Kerr, George D.

    2005-01-01

    The extensive efforts to review the dosimetry of the atomic-bomb survivors and formulate the new dosimetry system DS02 have been greatly welcomed by the Radiation Effects Research Foundation (RERF). This accomplishment is a fine tribute to the importance of the epidemiological studies being conducted at RERF. No other study is so informative of the effects of radiation on human health. The gracious participation in the RERF program by the atomic-bomb survivors allows us to contribute to the well being of these individuals, and the high quality of the data obtained allows the RERF results to feature so prominently in the formulation of international guidelines for radiation protection. Such a great effort to improve and substantiate the dosimetry would not otherwise have been justified. RERF greatly appreciates the independent work of the U.S. and Japanese Working Groups on the atomic-bomb dosimetry and the review by the Joint Senior Review Group of this overall effort. We are assured that unbiased development of the new dosimetry system will reflect well in its application in the RERF epidemiology study. The documentation included in this report will serve as reference for the many deliberations concluded. The title publications are divided into 2 volumes. This is the second volume. The 29 of the reports in each chapter are indexed individually. (J.P.N.)

  11. Optical absorption and photoluminescence properties of chromium in different host glasses

    Energy Technology Data Exchange (ETDEWEB)

    Lachheb, R., E-mail: raouialach66@gmail.com [LaboratoireGéoressources, Matériaux, Environnement et Changements Globaux, Faculty of Sciences of Sfax, Sfax University, 3018 Sfax (Tunisia); Herrmann, A. [Otto-Schott-Institut, Jena University, Fraunhoferstraße 6, 07743 Jena (Germany); Damak, K. [LaboratoireGéoressources, Matériaux, Environnement et Changements Globaux, Faculty of Sciences of Sfax, Sfax University, 3018 Sfax (Tunisia); Rüssel, C. [Otto-Schott-Institut, Jena University, Fraunhoferstraße 6, 07743 Jena (Germany); Maâlej, R. [LaboratoireGéoressources, Matériaux, Environnement et Changements Globaux, Faculty of Sciences of Sfax, Sfax University, 3018 Sfax (Tunisia)

    2017-06-15

    The optical absorption, excitation and fluorescence spectra, and emission lifetimes of chromium (III) were investigated in a wide variety of oxide glasses (aluminosilicate, aluminate and phosphate). For all glasses, weak crystal field strengths were deduced from the absorption spectra. The effect of the glass matrix and the Cr{sup 3+} concentration on the fluorescence properties of Cr{sup 3+} ions were investigated. An increased fluorescence intensity of Cr{sup 3+}was found for glasses of low optical basicity, the spectral position of the Cr{sup 3+} absorption and emission, however, was hardly influenced by the glass composition. The optical absorption spectra of the chromium doped aluminosilicate and aluminate glasses showed the presence of Cr{sup VI}, while in phosphate glasses most chromium occurred as Cr{sup 3+} ions. Furthermore, for the glass with the lowest basicity, the Cr{sup 3+}concentration was optimized in order to achieve maximum fluorescence emission intensity.

  12. Dosimetry methods

    DEFF Research Database (Denmark)

    McLaughlin, W.L.; Miller, A.; Kovacs, A.

    2003-01-01

    Chemical and physical radiation dosimetry methods, used for the measurement of absorbed dose mainly during the practical use of ionizing radiation, are discussed with respect to their characteristics and fields of application....

  13. Examination of the Measurement of Absorption Using the Reverberant Room Method for Highly Absorptive Acoustic Foam

    Science.gov (United States)

    Hughes, William O.; McNelis, Anne M.; Chris Nottoli; Eric Wolfram

    2015-01-01

    The absorption coefficient for material specimens are needed to quantify the expected acoustic performance of that material in its actual usage and environment. The ASTM C423-09a standard, "Standard Test Method for Sound Absorption and Sound Absorption Coefficients by the Reverberant Room Method" is often used to measure the absorption coefficient of material test specimens. This method has its basics in the Sabine formula. Although widely used, the interpretation of these measurements are a topic of interest. For example, in certain cases the measured Sabine absorption coefficients are greater than 1.0 for highly absorptive materials. This is often attributed to the diffraction edge effect phenomenon. An investigative test program to measure the absorption properties of highly absorbent melamine foam has been performed at the Riverbank Acoustical Laboratories. This paper will present and discuss the test results relating to the effect of the test materials' surface area, thickness and edge sealing conditions. A follow-on paper is envisioned that will present and discuss the results relating to the spacing between multiple piece specimens, and the mounting condition of the test specimen.

  14. Microwave Absorption Properties of Co@C Nanofiber Composite for Normal and Oblique Incidence

    Science.gov (United States)

    Zhang, Junming; Wang, Peng; Chen, Yuanwei; Wang, Guowu; Wang, Dian; Qiao, Liang; Wang, Tao; Li, Fashen

    2018-05-01

    Co@C nanofibers have been prepared by an electrospinning technique. Uniform morphology of the nanofibers and good dispersion of the magnetic cobalt nanoparticles in the carbon fiber frame were confirmed by field-emission scanning electron microscopy and high-resolution transmission electron microscopy. The electromagnetic parameters of a composite absorber composed of Co@C nanofibers/paraffin were measured from 2 GHz to 15 GHz. The electromagnetic wave absorption properties were simulated and investigated in the case of normal and oblique incidence. In the normal case, the absorber achieved absorption performance of - 40 dB at 7.1 GHz. When the angle of incidence was increased to 60°, the absorption effect with reflection loss (RL) exceeding - 10 dB could still be obtained. These results demonstrate that the reported Co@C nanofiber absorber exhibits excellent absorption performance over a wide range of angle of incidence.

  15. Research on the experimental verification of dosimetry calculations. Progress report

    International Nuclear Information System (INIS)

    Poston, J.W.

    1984-06-01

    Research has been focused on the development of a technique to section PATE organ dosimeters and the application of the technique to dosimetry of the extremities. In addition, a realistic model for the head and neck region has been designed and a model for the circulating blood has been proposed

  16. Study of the personal dosimetry service by thermoluminiscence

    International Nuclear Information System (INIS)

    Penaherrera, Patricio; Buitron, Susana; Prado, Elizabeth; Ceron Fabiola

    1992-01-01

    This paper is concerned with the personal dosimetry service given by the Ecuadorian Atomic Energy Commission to radiation exposed workers in Ecuador. The study has taken in consideration the number of professionals working in Ecuador by province and by area of work, and also the radiation doses received by them during the period 1987-1990

  17. State of the art of solid state dosimetry

    International Nuclear Information System (INIS)

    Souza, Susana O.; Yamamoto, Takayoshi; D'Errico, Francesco

    2014-01-01

    Passive solid-state detectors still dominate the personal dosimetry field. This article provides state of the art in this field and summarizes the most recent works presented on TL, OSL and RPL during the 17th International Conference on Solid State Dosimetry held in Recife in September 2013. The Article contains in particular the techniques Thermoluminescence (TL), Optically Stimulated Luminescence (OSL), radio photoluminescence (RPL). Thermoluminescence has the biggest advantage of the wide availability of commercial materials for dosimetry, and the nature tissue-equivalent of several of these materials. The limitation of the TL dosimetry presents fading luminance signal and the need for high temperatures to obtain the signal. The Optically Stimulated Luminescence has the advantages of high sensitivity, the possibility of multiple reading, while its limit is the need to use response compensating filters in addition to the high cost of equipment and dosimeters still restricted very few options trading . The radio photoluminescence has a reading that is completely non-destructive, but their dosimeters present lack of tissue-equivalent and a high cost. Presents the details of the techniques and the advantages and limitations of each of these will be discussed

  18. Plastic film materials for dosimetry of very large absorbed doses

    DEFF Research Database (Denmark)

    McLaughlin, W.L.; Miller, Arne; Abdel-Rahim, F.

    1985-01-01

    Most plastic films have limited response ranges for dosimetry because of radiation-induced brittleness, degradation, or saturation of the signal used for analysis (e.g. spectrophotometry) at high doses. There are, however, a few types of thin plastic films showing linearity of response even up...... to doses as high as 2 × 106 Gy (200 Mrad) without severe loss of mechanical properties. Among many candidate film types tested, those showing such resistance to radiation damage and continued response at such high doses are polyethylene terephthalate, high-density polyethylene, dyed polyvinylchloride......, the dyed polychlorostyrenes show essentially the same response to radiation-processing gamma-ray fields and to very high-intensity electron beams, and a relatively stable absorption spectrum at wavelengths for dosimetry analysis in the visible spectral region of ≈430 nm....

  19. Thermoluminescence albedo-neutron dosimetry

    International Nuclear Information System (INIS)

    Strand, T.; Storruste, A.

    1986-10-01

    The report discusses neutron detection with respect to dosimetry and compares different thermoluminescent dosimetry materials for neutron dosimetry. Construction and calibration of a thermoluminescence albedo neutron dosemeter, developed by the authors, is described

  20. The personal dosimetry in Mexico; La dosimetria personal en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, M.A. [Proxtronics/ Asesoria Integral en Dosimetria Termoluminiscente S.A. de C.V., Canal de Miramontes 2030-14, Col. Educacion, 04400 Mexico D.F. (Mexico)]. e-mail: aidtsa@avantel.net

    2006-07-01

    The Personal Dosimetry in Mexico, has an approximately 30 year-old history; and it had been and it is at the moment, one of the more important resources with which the personnel that works with ionizing radiation sources counts for its protection. The Personal Dosimetry begins with the film dosimetry, technique that even continues being used at the present time by some users, and the main reason of its use is for economic reasons. At the moment this technique, it has been surpassed, by the Thermoluminescent dosimetry, which has taken a lot of peak, mainly by the technological development with which it is counted at the present time; what has given as a result that this technique becomes tip technology; that supported in the characteristic of the used materials, as the handling and processing of the information associated with the new PC, digitizer cards, software etc, what has allowed increases it potential. In this work the current necessities of the market are presented as well as an analysis of the future real necessities in Mexico, at national level, the companies that provide this service and that they spread to satisfy this necessity of the market, including the different used technologies are also mentioned. The application ranges, at the same time, of the advantages and disadvantages of the different systems of Personal Dosimetry in the market. The companies that at the moment provide the service of Personal Dosimetry, its use materials and equipment in indistinct form, for the monitoring of gamma radiation, beta particles, different qualities of x-ray radiation, and sometimes neutrons. The monitoring of the exposed personnel at the diverse sources of ionizing radiation mentioned is carried out in many occasions without having with the materials (detectors), neither the appropriate infrastructure and therefore without the quality control that guarantees a correct evaluation of the dose equivalent, as a result of the exposure to the ionizing radiations; it

  1. Secondary standard dosimetry laboratory at the Boris Kidric Institute

    International Nuclear Information System (INIS)

    Kovacevic, M.; Velickovic, D.; Vukcevic, M.

    1989-01-01

    Essential data about Secondary Standard Dosimetry Laboratory at the Boris Kidric Institute are stated in this paper. The description of the laboratory is given and the possibilities of X, gamma and neutron dose measurements, as well as the basic equipment (author)

  2. Report of the Intercomparison program by thermoluminescent dosimetry for Secondary Standard Dosimetry Laboratories

    International Nuclear Information System (INIS)

    Papadopulos, Susana

    2000-01-01

    In this report the results of an intercomparison program within a research coordinated program are presented. This is a third phase of the study that consisted in to evaluate the implementation of the new ICRU quantities for individual monitoring by the SSDLs, their capabilities to perform irradiations in different angles and the interpretation of the standard ISO 4370-3. This phase as well the first one was coordinated by Argentina through the Autoridad Regulatoria Nuclear that verified the performance of the participant laboratories. The SSDL of Argentina calibrated the dosimetric system to be used, and sent a set of tld dosimeters for irradiation at the SSDL or dosimetry laboratories of nine countries of latin america

  3. Enhanced microwave absorption properties of Ni-doped ordered mesoporous carbon/polyaniline nanocomposites

    International Nuclear Information System (INIS)

    Wang, Liuding; Wu, Hongjing; Shen, Zhongyuan; Guo, Shaoli; Wang, Yiming

    2012-01-01

    Highlights: ► OMC-Ni/PANI nanocomposites were prepared by in situ polymerization method. ► The effective absorption bandwidth was 4.7 GHz for OMC-Ni0.15/PANI. ► OMC-Ni/PANI showed excellent microwave absorption with respect to OMC-Ni. ► This effect could be mainly attributed to the improvement of impendence matching. - Abstract: We propose and demonstrate a new scheme to improve microwave absorption property through polyaniline (PANI)-functionalized Ni-doped ordered mesoporous carbon (OMC) by in situ polymerization method. The polymer-functionalized nanocomposites, embedding polyaniline within ordered mesoporous carbon, exhibit strong and broadband microwave absorption due to its better dielectric loss characteristic. OMC-Ni0.15/PANI exhibits an effective absorption bandwidth (i.e., reflection loss (RL) ≤ −10 dB) of 4.7 GHz and an absorption peak of −51 dB at 9.0 GHz. The absorption peak intensity and position can be tuned by controlling the thickness of the coating.

  4. Electromagnetic and Microwave Absorption Properties of Carbonyl Tetrapod-Shaped Zno Nanostructures Composite Coatings

    Science.gov (United States)

    Yu, Haibo; Qin, Hui; Huang, Yunhua

    2012-08-01

    CIP/T-ZnO/EP composite coatings with carbonyl iron powders (CIP) and tetrapodshaped ZnO (T-ZnO) nanostructures as absorbers, and epoxy resin (EP) as matrix were prepared. The complex permittivity, permeability and microwave absorption properties of the coatings were investigated in the frequency range of 2-18 GHz. The effects of the weight ratio (CIP/T-ZnO/EP), the thickness and the solidification temperature on microwave absorption properties were discussed. When the weight ratio (CIP/TZnO/ EP), the thickness and the solidification temperature is 28:2:22, 1.8 mm, and 10°C, respectively, the optimal wave absorption with the minimum reflection loss (RL) value of -22.38 dB at 15.67 GHz and the bandwidth (RLcoatings may have a promising application in Ku-band (12-18 GHz).

  5. Research needs in metabolism and dosimetry of the actinides

    International Nuclear Information System (INIS)

    Richmond, C.R.

    1978-01-01

    The following topics are discussed: uranium mine and mill tailings; environmental standards; recommendations of NCRP and ICRP; metabolic models and health effects; life-time exposures to actinides and other alpha emitters; high-specific-activity actinide isotopes versus naturally occurring isotopic mixtures of uranium isotopes; adequacy of the n factor; and metabolism and dosimetry;

  6. The application of an automated thermoluminescence dosimetry system to environmental γ-dosimetry

    International Nuclear Information System (INIS)

    Jones, A.R.

    1977-07-01

    A personnel monitoring system comprising thermoluminescent dosimeters (TLDs) and an automatic TLD reader has been applied to environmental gamma dosimetry. For this purpose the accuracy of measurement at low exposures (10 to 100 mR) acquired over long periods (3 or 12 months) is important. To improve the accuracy and reliability of the system for this application the following steps were taken: the dosimeters were sensitized by irradiation with γ-rays and annealed while being irradiated with UV light; the sensitivity of each, identified dosimeter was measured and used to correct exposure measurements; the gasketted holders were modified to contain TLDs mounted on two identified plaques. Measurements of linearity, variability (with and without individual calibration) fading and energy dependence are presented. (author)

  7. Dosimetry of the patient and occupational in interventional procedures

    International Nuclear Information System (INIS)

    Andisco, D.; Bourel, V.; Schmidt, L.; Fernandez, N.

    2014-08-01

    The big necessity to estimate the entrance doses in skin that the patients receive when are exposed to interventional procedures and the personal dosimetry of the professionals that work in these procedures in operating room, has taken to the analysis of different possibilities that allow to carry out these estimates. The objective of this work was to analyze the possibility of using Optically Stimulated Luminescence dosimeters; comparing the results with ionizing cameras and electronic personal dosimeters. To carry out these estimates, we work with a X-ray equipment Phillips Allure, acrylic phantoms, a dosimetry system formed by ionization camera and dosimeter UNIDOS E, OSL (Nano dots) dosimeters and electronic lavalieres Aloka brand, PDM 117 models. To estimate the doses that the patients receive, entrance dose was measured in skin and in personal dosimetry inside places where the medical professionals are habitually located in different situations among 5 and 60 irradiation min. In the case of direct radiation, the OSL (Nano dots) present reliable readings and only were dispersed values for the measurements of secondary radiation. The measured values and the linking among them were also analyzed. The OSL (Nano dot) dosimetry behaves reliable way when is located in the ranges of more dose to 0,1 mGy, according to the maker indications and fundamentally for direct beams of the hemodynamics equipment being ideal for the measurement of entrance dose in skin. For the Nano dots use in personal dosimetry the results should be read carefully for values major to 0,1 mGy and being completely inappropriate for minor values. (Author)

  8. High-dosage dosimetry programme of the IAEA

    International Nuclear Information System (INIS)

    Mehta, K.

    1999-01-01

    The high-dose dosimetry programme was initiated by the International Atomic Energy Agency in 1977. Like any other Agency programme, this one has various activities. These cover: research contracts and research agreements, co-ordinated research projects (CRP), training courses, and laboratory-based activities. The Agency's dose quality audit service (International Dose Assurance Service, IDAS), initiated in 1985, is one of the key elements of the programme. At earlier times, the technical part was operated through a laboratory in Germany. However, after purchasing the Bruker ESR spectrometer, the entire service has been operated from the Agency since 1992. This audit service has served well the needs of various institutes around the world involved with radiation processing. We have had two Co-ordinated Research Projects (the second one is in its last year) over the last several years. Both were/are aimed at standardization of dosimetry for radiation processing. Nine or ten participants of each CRP were about evenly distributed between the developed and developing Member States. In collaboration with the Food and Environmental Protection Section and the Industrial Applications and Chemistry Section, the Dosimetry and Medical Radiation Physics Section has participated in several training courses; these have been mainly regional courses. This collaboration has worked well since such courses combine specific radiation processing applications with the needs of good dosimetry and process control. Also, the Agency has organised several dose intercomparisons in recent time. The activities of the high-dose dosimetry programme since the last symposium (November 1990) are reviewed here. (author)

  9. Alanine dosimetry at NPL - the development of a mailed reference dosimetry service at radiotherapy dose levels

    International Nuclear Information System (INIS)

    Sharpe, P.H.G.; Sephton, J.P.

    1999-01-01

    In this paper we describe the work that has been carried out at National Physical Laboratory (NPL) to develop a mailed alanine reference dosimetry service for radiotherapy dose levels. The service is based on alanine/paraffin wax dosimeters produced at NPL. Using a data analysis technique based on spectrum fitting, it has been possible to achieve a precision of dose measurement better than ±0.05 Gy (1σ). A phantom set has been developed for use in high energy photon beams, which enables simultaneous irradiation of alanine dosimeters and ionisation chambers in a well defined geometry. Studies in photon beams of energies between 60 Co and 20 MeV have shown no significant energy dependence (<1%) for alanine relative to dose determination using a graphite calorimeter. Work is underway to extend the service to electron beams, and preliminary results are presented on the direct calibration of alanine in electron beams using a graphite calorimeter. (author)

  10. Topics in radiation dosimetry radiation dosimetry

    CERN Document Server

    1972-01-01

    Radiation Dosimetry, Supplement 1: Topics in Radiation Dosimetry covers instruments and techniques in dealing with special dosimetry problems. The book discusses thermoluminescence dosimetry in archeological dating; dosimetric applications of track etching; vacuum chambers of radiation measurement. The text also describes wall-less detectors in microdosimetry; dosimetry of low-energy X-rays; and the theory and general applicability of the gamma-ray theory of track effects to various systems. Dose equivalent determinations in neutron fields by means of moderator techniques; as well as developm

  11. Fluorescence and absorption properties of chromophoric dissolved organic matter (CDOM) in coastal surface waters of the Northwestern Mediterranean Sea (Bay of Marseilles, France)

    Science.gov (United States)

    Para, J.; Coble, P. G.; Charrière, B.; Tedetti, M.; Fontana, C.; Sempéré, R.

    2010-07-01

    Seawater samples were collected in surface waters (2 and 5 m depths) of the Bay of Marseilles (Northwestern Mediterranean Sea; 5°17'30'' E, 43°14'30'' N) during one year from November 2007 to December 2008 and studied for total organic carbon (TOC) as well as chromophoric dissolved organic matter (CDOM) optical properties (absorbance and fluorescence). The annual mean value of surface CDOM absorption coefficient at 350 nm [aCDOM(350)] was very low (0.10 ± 0.02 m-1) with in comparison to values usually found in coastal waters, and no significant seasonal trend in aCDOM(350) could be determined. By contrast, the spectral slope of CDOM absorption (SCDOM) was significantly higher (0.023 ± 0.003 nm-1) in summer than in fall and winter periods (0.017 ± 0.002 nm-1), reflecting either CDOM photobleaching or production in surface waters during stratified sunny periods. The CDOM fluorescence, assessed through excitation emission matrices (EEMs), was dominated by protein-like component (peak T; 1.30-21.94 QSU) and marine humic-like component (peak M; 0.55-5.82 QSU), while terrestrial humic-like fluorescence (peak C; 0.34-2.99 QSU) remained very low. This reflected a dominance of relatively fresh material from biological origin within the CDOM fluorescent pool. At the end of summer, surface CDOM fluorescence was very low and strongly blue shifted, reinforcing the hypothesis of CDOM photobleaching. Our results suggested that unusual Rhône River plume eastward intrusion events may reach Marseilles Bay within 2-3 days and induce local phytoplankton blooms and subsequent fluorescent CDOM production (peaks M and T) without adding terrestrial fluorescence signatures (peak C). Besides Rhône River plumes, mixing events of the entire water column injected humic (peaks C and M) CDOM from the bottom into the surface and thus appeared also as an important source of CDOM in surface waters of the Marseilles Bay. Therefore, the assessment of CDOM optical properties, within the

  12. The impact of the reassessment of A-bomb dosimetry

    International Nuclear Information System (INIS)

    Kopecky, K.J.; Preston, D.L.

    1988-07-01

    This report examines the anticipated impact of the adoption by RERF of a new atomic bomb radiation dosimetry system to replace the revised tentative 1965 dosimetry system (T65DR). The current binational effort to reassess A-bomb dosimetry will eventually produce information about air doses and attenuation due to shielding by structures and body tissue. A method for computing individual survivors' total body surface exposure doses and organ doses from such data was developed, and a set of interim 1985 dosimetry (I85D) estimates was computed by this method using the data available to RERF in late 1984. Estimates of I85D total body surface exposure doses could be computed for 64,804 of 91,231 exposed survivors with T65DR dose estimates; following present plans, revised dose estimates may become available for an additional group of 10,000 to 12,000 exposed survivors. Mortality from leukemia and from all cancers except leukemia was examined in relation to I85D total body surface exposure doses (gamma plus neutron); parallel analyses using T65DR exposure doses were also conducted for the same set of survivors. Overall estimates of radiogenic excess risk based on I85D total body surface doses were about 50 % greater than those based on T65DR doses. Nonsignificant differences of only 3 % or less between the radiogenic excess risks for Hiroshima and Nagasaki survivors were observed in relation to I85D doses. Modification of the radiation dose response by sex, age at the time of the bombing, or time since exposure was qualitatively similar for I85D and T65DR. For both leukemia and nonleukemic cancer mortality, the radiogenic excess risk was found to increase as a linear function of I85D total body surface dose; significantly poorer fits were obtained with pure quadratic dose-response functions, while linear-quadratic dose responses did not provide significantly better fits. (J.P.N.)

  13. Development of Prediction Tool for Sound Absorption and Sound Insulation for Sound Proof Properties

    OpenAIRE

    Yoshio Kurosawa; Takao Yamaguchi

    2015-01-01

    High frequency automotive interior noise above 500 Hz considerably affects automotive passenger comfort. To reduce this noise, sound insulation material is often laminated on body panels or interior trim panels. For a more effective noise reduction, the sound reduction properties of this laminated structure need to be estimated. We have developed a new calculate tool that can roughly calculate the sound absorption and insulation properties of laminate structure and handy ...

  14. The Effects of CaCO3 Coated Wood Free Paper Usage as Filler on Water Absorption, Mechanical and Thermal Properties of Cellulose-High Density Polyethylene Composites

    Directory of Open Access Journals (Sweden)

    Emrah PEŞMAN

    2016-11-01

    Full Text Available In this study some physical, mechanical and thermal characteristics of high density polyethylene (HDPE and CaCO3 coated/pigmented wood free paper fiber composites were investigated. The fillers used in this study were uncoated cellulose, 5.8 %, 11.5 %, 16.5 % and 23.1 % CaCO3 coated wood free paper fibers. Each filler type was mixed with HDPE at 40% by weight fiber loading. In this case, the ratio of CaCO3 in plastic composites were calculated as 0 %, 2.3 %, 4.6 %, 6.6 % and 9.2 % respectively. Increased CaCO3 ratio improved the moisture resistant, flexural and tensile strength of cellulose-HDPE composites. However, the density of the cellulose-HDPE composites increased with CaCO3 addition. Energy Dispersive Spectroscopy on Scanning Electron Microscope analysis demonstrated the uniform distribution of CaCO3 and cellulose fiber in plastic matrix. In addition, the thermal properties of fiber plastic composites were investigated. The results of Differential scanning calorimetry analysis revealed that the crystallinity of the samples decreased with increasing CaCO3 content. Consequently, this work showed that CaCO3 coated waste paper fibers could be used as reinforcing filler against water absorption in thermoplastic matrix.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.14222

  15. The Need for New Dosimetric Approach in CT Dosimetry

    International Nuclear Information System (INIS)

    Ben-Shlomo, A.; Iacobovici, E.

    2004-01-01

    Three decades after the invention of the first CT in 1972, it became a major tool in diagnostic radiology. The use of CT for various applications is getting wider every year. The quantity of CT procedures performed in Israel every year is estimated as 500,000. About 10% of those are pediatric procedures, for children under age 10. CT procedures increase is estimated at 5-10 % per annum. In spite the fact that CT contributes to about 1/8 of the total number of diagnostic X-ray procedures in Israel, the CT collective dosage is about 40% of the total collective dosage in the said procedures (about 3,500 Man*Sv per year). Medical radiation dosage is the first contributor to population dosage, resulting from artificial radiation sources. Diagnostic X-ray radiation dosage is the first contributor to medical radiation dose (including radiation dose from diagnostic X-ray, nuclear medicine and radiotherapy with exclusion of the target organ dose). Among medical X-ray different applications, CT procedure is the first cause to radiation dose of the population according to X-ray diagnostic procedures. The above facts emphasize the need to focus on CT in order to reduce the medical collective dose of the public. Several dosimetric units have appeared in recent years in order to comply with the need for CT Dosimetry. The CTDI Unit that served so well during the first CT years is no longer sufficient, as is, for modern instruments. This basic unit has become a complex concept that covers new units: CTDI W , CTDI VOL , CTDI 100 , MSAD and DLP. The search for a simple way to apply these units in order to calculate effective dosage during CT examinations is not straightforward. Modern equipment is simultaneously using 4 and 16 slices. Manufacturers are endeavoring to develop the next generation equipment with 256 slices used simultaneously (expected on the market in the next 1-2 years). This situation sets technology one step forward regarding the dosimetry methods used for organ

  16. Water absorption and mechanical properties of water-swellable natural rubber

    Directory of Open Access Journals (Sweden)

    Diew Saijun

    2009-11-01

    Full Text Available Water-swellable rubber (WSR was prepared by blending superabsorbent polymer (SAP of crosslinked poly(acrylamide-co-sodium acrylate with natural rubber in latex condition. The crosslinked poly(acrylamide-co-sodium acrylate was first prepared by inverse suspension polymerization from acrylamide and sodium acrylate monomers with potassiumpersulfate initiator and N,N-methylenebisacrylamide crosslinker. The reaction was carried out at 60oC for 40 mins. Water absorption properties, such as the degree of water absorption, water absorption rate, degree of weight loss, and mechanicalproperties of WSR were then investigated. It was found that the degree of water absorption, water absorption rate, and thedegree of weight loss increased, while tensile strength and elongation at break decreased with increasing quantity of SAP inthe blends. However, the degree of water absorption, degree of weight loss, and elongation at break decreased, but tensilestrength increased with increasing quantity of the N-tert-butyl-2-benzothiazyl sulphenamide (TBBS accelerator used in thecompounds formulation.

  17. Electrical transport properties of individual WS2 nanotubes and their dependence on water and oxygen absorption

    Science.gov (United States)

    Zhang, Chaoying; Ning, Zhiyuan; Liu, Yang; Xu, Tingting; Guo, Yao; Zak, Alla; Zhang, Zhiyong; Wang, Sheng; Tenne, Reshef; Chen, Qing

    2012-09-01

    The electrical properties of WS2 nanotubes (NTs) were studied through measuring 59 devices. Important electrical parameters, such as the carrier concentration, mobility, and effective barrier height at the contacts, were obtained through fitting experimental non-linear I-V curves using a metal-semiconductor-metal model. The carrier mobility was found to be several orders of magnitude higher than that have been reported previously for WS2 NTs. Water absorption was found to decrease the conductivity and carrier mobility of the NTs, and could be removed when the sample was dried. Oxygen absorption also slightly decreased the conductivity of WS2 NTs.

  18. Transient Infrared Measurement of Laser Absorption Properties of Porous Materials

    Directory of Open Access Journals (Sweden)

    Marynowicz Andrzej

    2016-06-01

    Full Text Available The infrared thermography measurements of porous building materials have become more frequent in recent years. Many accompanying techniques for the thermal field generation have been developed, including one based on laser radiation. This work presents a simple optimization technique for estimation of the laser beam absorption for selected porous building materials, namely clinker brick and cement mortar. The transient temperature measurements were performed with the use of infrared camera during laser-induced heating-up of the samples’ surfaces. As the results, the absorbed fractions of the incident laser beam together with its shape parameter are reported.

  19. Transient Infrared Measurement of Laser Absorption Properties of Porous Materials

    Science.gov (United States)

    Marynowicz, Andrzej

    2016-06-01

    The infrared thermography measurements of porous building materials have become more frequent in recent years. Many accompanying techniques for the thermal field generation have been developed, including one based on laser radiation. This work presents a simple optimization technique for estimation of the laser beam absorption for selected porous building materials, namely clinker brick and cement mortar. The transient temperature measurements were performed with the use of infrared camera during laser-induced heating-up of the samples' surfaces. As the results, the absorbed fractions of the incident laser beam together with its shape parameter are reported.

  20. On the use of new generation mobile phone (smart phone) for retrospective accident dosimetry

    International Nuclear Information System (INIS)

    Lee, J.I.; Chang, I.; Pradhan, A.S.; Kim, J.L.; Kim, B.H.; Chung, K.S.

    2015-01-01

    Optically stimulated luminescence (OSL) characteristics of resistors, inductors and integrated-circuit (IC) chips, extracted from new generation smart phones, were investigated for the purpose of retrospective accident dosimetry. Inductor samples were found to exhibit OSL sensitivity about 5 times and 40 times higher than that of the resistors and the IC chips, respectively. On post-irradiation storage, the resistors exhibited a much higher OSL fading (about 80 % in 36 h as compared to the value 3 min after irradiation) than IC chips (about 20 % after 36 h) and inductors (about 50 % in 36 h). Higher OSL sensitivity, linear dose response (from 8.7 mGy up to 8.9 Gy) and acceptable fading make inductors more attractive for accident dosimetry than widely studied resistors. - Highlights: • OSL properties of electronic components from a smart phone were investigated. • OSL Sensitivity of inductor was estimated to 5 times higher than that of resistor. • Inductor exhibits most attractive properties for retrospective accident dosimetry.

  1. Personnel neutron dosimetry

    International Nuclear Information System (INIS)

    Hankins, D.

    1982-04-01

    This edited transcript of a presentation on personnel neutron discusses the accuracy of present dosimetry practices, requirements, calibration, dosemeter types, quality factors, operational problems, and dosimetry for a criticality accident. 32 figs

  2. Modeled Aerosol Optical Properties From Measurement-Based Mixtures of Chemical Species: Assessing the Impacts of Particle Morphology and Absorption

    Science.gov (United States)

    Kreidenweis, Sonia

    2002-01-01

    This report serves as the final report for the Colorado State University portion of this grant. The original grant was awarded to CSU under the direction of co-Principal Investigators Kirk Fuller and Sonia Kreidenweis. Upon Dr. Fuller's relocation to the University of Alabama - Huntsville, the major portion of the award was also relocated. The following summarizes only that work completed by Prof. Kreidenweis under her remaining award.

  3. Comparative Evaluation of Effect of Water Absorption on the Surface Properties of Heat Cure Acrylic: An in vitro Study

    OpenAIRE

    Chandu, G S; Asnani, Pooja; Gupta, Siddarth; Faisal Khan, Mohd.

    2015-01-01

    Background: Use of alkaline peroxide denture cleanser with different temperature of water could cause a change in surface hardness of the acrylic denture and also has a bleaching effect. The purpose of the study was to determine the effect of increased water content during thermal cycling of hot water-treated acrylic on the surface hardness of acrylic denture base when compared to warm water treated acrylic. And to compare the bleaching effect of alkaline peroxide solution on the acrylic dent...

  4. Dosimetry for radiation processing

    DEFF Research Database (Denmark)

    Miller, Arne

    1986-01-01

    During the past few years significant advances have taken place in the different areas of dosimetry for radiation processing, mainly stimulated by the increased interest in radiation for food preservation, plastic processing and sterilization of medical products. Reference services both...... and sterilization dosimetry, optichromic dosimeters in the shape of small tubes for food processing, and ESR spectroscopy of alanine for reference dosimetry. In this paper the special features of radiation processing dosimetry are discussed, several commonly used dosimeters are reviewed, and factors leading...

  5. Facile preparation and enhanced microwave absorption properties of flake carbonyl iron/Fe3O4 composite

    International Nuclear Information System (INIS)

    Min, Dandan; Zhou, Wancheng; Luo, Fa; Zhu, Dongmei

    2017-01-01

    Highlights: • Flake carbonyl iron/Fe 3 O 4 composites were prepared by surface oxidation technique. • Lower permittivity and modest permeability was obtained by the FCI/Fe 3 O 4 composites. • Enhanced absorption efficiency and broader absorption band were obtained. - Abstract: Flake carbonyl iron/Fe 3 O 4 (FCI/Fe 3 O 4 ) composites with enhanced microwave absorption properties were prepared by a direct and flexible surface oxidation technique. The phase structures, morphology, magnetic properties, frequency-dependent electromagnetic and microwave absorption properties of the composites were investigated. The measurement results showed that lower permittivity as well as modest permeability was obtained by the FCI/Fe 3 O 4 composites. The calculated microwave absorption properties indicated that enhanced absorption efficiency and broader absorption band were obtained by the FCI/Fe 3 O 4 composite comparing with the FCI composite. The absorption frequency range with reflection loss (RL) below −5 dB of FCI/Fe 3 O 4 composites at reaction time of 90 min at thickness of 1.5 mm is 13.3 GHz from 4.7 to 18 GHz, while the bandwidth of the FCI composite is only 5.9 GHz from 2.6 to 8.5 GHz at the same thickness. Thus, such absorbers could act as effective and wide broadband microwave absorbers in the GHz range.

  6. Near-infrared radiation absorption properties of covellite (CuS using first-principles calculations

    Directory of Open Access Journals (Sweden)

    Lihua Xiao

    2016-08-01

    Full Text Available First-principles density functional theory was used to investigate the electronic structure, optical properties and the origin of the near-infrared (NIR absorption of covellite (CuS. The calculated lattice constant and optical properties are found to be in reasonable agreement with experimental and theoretical findings. The electronic structure reveals that the valence and conduction bands of covellite are determined by the Cu 3d and S 3p states. By analyzing its optical properties, we can fully understand the potential of covellite (CuS as a NIR absorbing material. Our results show that covellite (CuS exhibits NIR absorption due to its metal-like plasma oscillation in the NIR range.

  7. Comparative Evaluation of Effect of Water Absorption on the Surface Properties of Heat Cure Acrylic: An in vitro Study

    Science.gov (United States)

    Chandu, G S; Asnani, Pooja; Gupta, Siddarth; Faisal Khan, Mohd.

    2015-01-01

    Background: Use of alkaline peroxide denture cleanser with different temperature of water could cause a change in surface hardness of the acrylic denture and also has a bleaching effect. The purpose of the study was to determine the effect of increased water content during thermal cycling of hot water-treated acrylic on the surface hardness of acrylic denture base when compared to warm water treated acrylic. And to compare the bleaching effect of alkaline peroxide solution on the acrylic denture base on hot water and warm water treated acrylic. Materials and Methods: Forty samples (10 mm × 10 mm × 2.5 mm) were prepared. After the calculation of the initial hardness 40 samples, each was randomly assigned to two groups. Group A: 20 samples were immersed in 250 ml of warm distilled water at 40°C with alkaline peroxide tablet. Group B: 20 samples were immersed in 250 ml of hot distilled water at 100°C with alkaline peroxide tablet. The surface hardness of each test sample was obtained using the digital hardness testing machine recording the Rockwell hardness number before the beginning of the soaking cycles and after completion of 30 soak cycles and compared. Values were analyzed using paired t-test. Five samples from the Group A and five samples from Group B were put side by side and photographed using a Nikon D 40 digital SLR Camera and the photographs were examined visually to assess the change in color. Results: Acrylic samples immersed in hot water showed a statistically significant decrease of 5.8% in surface hardness. And those immersed in warm water showed a statistically insignificant increase of 0.67% in surface hardness. Samples from the two groups showed clinically insignificant difference in color when compared to each other on examination of the photographs. Conclusion: Thermocycling of the acrylic resin at different water bath temperature at 40°C and 100°C showed significant changes in the surface hardness. PMID:25954074

  8. GENII (Generation II): The Hanford Environmental Radiation Dosimetry Software System: Volume 3, Code maintenance manual: Hanford Environmental Dosimetry Upgrade Project

    Energy Technology Data Exchange (ETDEWEB)

    Napier, B.A.; Peloquin, R.A.; Strenge, D.L.; Ramsdell, J.V.

    1988-09-01

    The Hanford Environmental Dosimetry Upgrade Project was undertaken to incorporate the internal dosimetry models recommended by the International Commission on Radiological Protection (ICRP) in updated versions of the environmental pathway analysis models used at Hanford. The resulting second generation of Hanford environmental dosimetry computer codes is compiled in the Hanford Environmental Dosimetry System (Generation II, or GENII). This coupled system of computer codes is intended for analysis of environmental contamination resulting from acute or chronic releases to, or initial contamination of, air, water, or soil, on through the calculation of radiation doses to individuals or populations. GENII is described in three volumes of documentation. This volume is a Code Maintenance Manual for the serious user, including code logic diagrams, global dictionary, worksheets to assist with hand calculations, and listings of the code and its associated data libraries. The first volume describes the theoretical considerations of the system. The second volume is a Users' Manual, providing code structure, users' instructions, required system configurations, and QA-related topics. 7 figs., 5 tabs.

  9. GENII [Generation II]: The Hanford Environmental Radiation Dosimetry Software System: Volume 3, Code maintenance manual: Hanford Environmental Dosimetry Upgrade Project

    International Nuclear Information System (INIS)

    Napier, B.A.; Peloquin, R.A.; Strenge, D.L.; Ramsdell, J.V.

    1988-09-01

    The Hanford Environmental Dosimetry Upgrade Project was undertaken to incorporate the internal dosimetry models recommended by the International Commission on Radiological Protection (ICRP) in updated versions of the environmental pathway analysis models used at Hanford. The resulting second generation of Hanford environmental dosimetry computer codes is compiled in the Hanford Environmental Dosimetry System (Generation II, or GENII). This coupled system of computer codes is intended for analysis of environmental contamination resulting from acute or chronic releases to, or initial contamination of, air, water, or soil, on through the calculation of radiation doses to individuals or populations. GENII is described in three volumes of documentation. This volume is a Code Maintenance Manual for the serious user, including code logic diagrams, global dictionary, worksheets to assist with hand calculations, and listings of the code and its associated data libraries. The first volume describes the theoretical considerations of the system. The second volume is a Users' Manual, providing code structure, users' instructions, required system configurations, and QA-related topics. 7 figs., 5 tabs

  10. GENII: The Hanford Environmental Radiation Dosimetry Software System: Volume 2, Users' manual: Hanford Environmental Dosimetry Upgrade Project

    International Nuclear Information System (INIS)

    Napier, B.A.; Peloquin, R.A.; Strenge, D.L.; Ramsdell, J.V.

    1988-11-01

    The Hanford Environmental Dosimetry Upgrade Project was undertaken to incorporate the internal dosimetry models recommended by the International Commission on Radiological Protection (ICRP) in updated versions of the environmental pathway analysis models used at Hanford. The resulting second generation of Hanford environmental dosimetry computer codes is compiled in the Hanford Environmental Dosimetry System (Generation II, or GENII). The purpose of this coupled system of computer codes is to analyze environmental contamination of, air, water, or soil. This is accomplished by calculating radiation doses to individuals or populations. GENII is described in three volumes of documentation. This second volume is a Users' Manual, providing code structure, users' instructions, required system configurations, and QA-related topics. The first volume describes the theoretical considerations of the system. The third volume is a Code Maintenance Manual for the user who requires knowledge of code detail. It includes logic diagrams, global dictionary, worksheets, example hand calculations, and listings of the code and its associated data libraries. 27 refs., 17 figs., 23 tabs

  11. Benefits of carbon addition on the hydrogen absorption properties of Mg-based thin films grown by Pulsed Laser Deposition

    International Nuclear Information System (INIS)

    Darok, X.; Rougier, A.; Bhat, V.; Aymard, L.; Dupont, L.; Laffont, L.; Tarascon, J.-M.

    2006-01-01

    Mg-Ni thin films were grown using Pulsed Laser Deposition. In situ optical changes from shiny metallic to transparent states were observed for films deposited in vacuum and under an Ar/H 2 gas mixture (93/7%), respectively. Optical changes were also achieved by ex situ hydrogenation under hydrogen gas pressure of 15 bars at 200 deg. C. However, after ex situ hydrogenation, the optical transmittance of the Mg-based hydrogenated thin films did not exceed 25%. Such limitation was attributed to oxygen contamination, as deduced by High Resolution Transmission Electron Microscopy observations, showing the co-existence of both Mg-based and MgO phases for as-deposited films. A significant decrease in oxygen contamination was successfully achieved with the addition of carbon, leading to the preparation of (Mg-based)-C x (x < 20%) thin films showing a faster and easier hydrogenation

  12. Tetrazole amphiphile inducing growth of conducting polymers hierarchical nanostructures and their electromagnetic absorption properties

    Science.gov (United States)

    Xie, Aming; Sun, Mengxiao; Zhang, Kun; Xia, Yilu; Wu, Fan

    2018-05-01

    Conducting polymers (CPs) at nano scales endow materials with special optical, electrical, and magnetic properties. The crucial factor to construct and regulate the micro-structures of CPs is the inducing reagent, particular in its chemical structure, such active sites, self-assembling properties. In this paper, we design and synthesize an amphiphile bearing tetrazole moiety on its skeleton, and use this amphiphile as an inducing reagent to prepare and regulate the micro-structures of a series of CPs including polypyrrole, polyaniline, poly(3,4-ethylenedioxythiophene) and poly(p-phenylenediamine). Because of the unique electric properties of CPs and size effect, we next explored the electromagnetic absorption performances of these CPs nanostructures. A synergetic combination of electric loss and magnetic loss is used to explain the absorption mechanism of these CPs nano-structures.

  13. Photoacoustic-fluorescence in vitro flow cytometry for quantification of absorption, scattering and fluorescence properties of the cells

    Science.gov (United States)

    Nedosekin, D. A.; Sarimollaoglu, M.; Foster, S.; Galanzha, E. I.; Zharov, V. P.

    2013-03-01

    Fluorescence flow cytometry is a well-established analytical tool that provides quantification of multiple biological parameters of cells at molecular levels, including their functional states, morphology, composition, proliferation, and protein expression. However, only the fluorescence and scattering parameters of the cells or labels are available for detection. Cell pigmentation, presence of non-fluorescent dyes or nanoparticles cannot be reliably quantified. Herewith, we present a novel photoacoustic (PA) flow cytometry design for simple integration of absorbance measurements into schematics of conventional in vitro flow cytometers. The integrated system allow simultaneous measurements of light absorbance, scattering and of multicolor fluorescence from single cells in the flow at rates up to 2 m/s. We compared various combinations of excitation laser sources for multicolor detection, including simultaneous excitation of PA and fluorescence using a single 500 kHz pulsed nanosecond laser. Multichannel detection scheme allows simultaneous detection of up to 8 labels, including 4 fluorescent tags and 4 PA colors. In vitro PA-fluorescence flow cytometer was used for studies of nanoparticles uptake and for the analysis of cell line pigmentation, including genetically encoded melanin expression in breast cancer cell line. We demonstrate that this system can be used for direct nanotoxicity studies with simultaneous quantification of nanoparticles content and assessment of cell viability using a conventional fluorescent apoptosis assays.

  14. Preparation and investigation of structural, magnetic and microwave absorption properties of cerium doped barium hexaferrite

    Directory of Open Access Journals (Sweden)

    P Kameli

    2015-01-01

    Full Text Available In this study the structure, magnetic and microwave absorption properties of cerium (Ce doped barium hexaferrite with general formulae BaCexFe12-xO19 (x=0.0, 0.05, 0.1, 0.15, 0.2 have been investigated. These samples have been prepared by sol- gel method. Influence of replacing Fe+3 ion by rare- earth Ce+3 ion on the structural, magnetic and microwave absorption properties have been investigated by X- ray diffraction (XRD, Fourier transform infrared (FT-IR, Vibrating sample magnetometer (VSM and vector network analyzer (VNA. X-ray diffraction analysis indicated that the samples are of single phase with space group p63/mmc. The magnetic properties of samples indicated that with the Ce doping the saturation magnetization show no regular behavior. Moreover, coercivity (Hc first decreased and reached to the minimum value for x=0.1 sample and then increased with Ce content increasing. Also, measurement of electromagnetic wave absorption in X and Ku frequency bands indicated that the maximum of reflection loss obtained for x=0.15 sample. Moreover, result indicated that absorption peak shifted toward a lower frequency when thickness was increased.

  15. Analysis of the intermediate-band absorption properties of type-II GaSb/GaAs quantum-dot photovoltaics

    Science.gov (United States)

    Ramiro, I.; Villa, J.; Tablero, C.; Antolín, E.; Luque, A.; Martí, A.; Hwang, J.; Phillips, J.; Martin, A. J.; Millunchick, J.

    2017-09-01

    Quantum-dot (QD) intermediate-band (IB) materials are regarded as promising candidates for high-efficiency photovoltaics. The sequential two-step two-photon absorption processes that take place in these materials have been proposed to develop high-efficiency solar cells and infrared (IR) photodetectors. In this work, we experimentally and theoretically study the interrelation of the absorptivity with transitions of carriers to and from the IB in type-II GaSb/GaAs QD devices. Our devices exhibit three optical band gaps with: EL=0.49 eV ,EH=1.02 eV , and EG=1.52 eV , with the IB located 0.49 eV above the valence band. These values are well supported by semiempirical calculations of the QDs electronic structure. Through intensity-dependent two-photon photocurrent experiments, we are able to vary the filling state of the IB, thus modifying the absorptivity of the transitions to and from this band. By filling the IB with holes via E =1.32 eV or E =1.93 eV monochromatic illumination, we demonstrate an increase in the EL-related absorptivity of more than two orders of magnitude and a decrease in the EH-related absorptivity of one order of magnitude. The antisymmetrical evolution of those absorptivities is quantitatively explained by a photoinduced shift of the quasi-Fermi level of the IB. Furthermore, we report the observation of a two-photon photovoltage, i.e., the contribution of subband gap two-photon absorption to increase the open-circuit voltage of solar cells. We find that the generation of the two-photon photovoltage is related, in general, to the production of a two-photon photocurrent. However, while photons with energy close to EL participate in the production of the two-photon photocurrent, they are not effective in the production of a two-photon photovoltage. We also report the responsivity of GaSb/GaAs QD devices performing as optically triggered photodetectors. These devices exhibit an amplification factor of almost 400 in the IR spectral region. This high

  16. Overview of the EMRAS biota dosimetry working group

    International Nuclear Information System (INIS)

    Kawaguchi, Isao; Doi, Masahiro

    2008-01-01

    Current principle of radiation protection systems is protection of human, because the human is assumed as the most sensitive organism. Protection framework of human is also believed to be effective for protection of non-human species. On the other hand, it is recently attracting the international interests how sustainability of the ecological services is influenced by environmental disturbances such as chemicals and radiation. Therefore, international concern about protection framework of nonhuman biota has arisen. By the international concern, European and American countries were respectively developed models to evaluate effects of radiation to biota. However, the models are based on their own assumptions, so that the international validity has not been confirmed. Therefore, in IAEA, biota dosimetry working group (BWG) was established in Environmental Modeling for Radiation Safety (EMRAS) program, which aimed to intercompare the models to validate their assumptions and estimations. This paper reports summary of the activity in EMRAS biota dosimetry working group. (author)

  17. Dosimetry characteristics of the Leksell gamma knife for stereotactic radiosurgery

    International Nuclear Information System (INIS)

    Wu, A.; Lindner, G.; Maitz, A.; Smarra, N.; Turco, R.F.; Kalend, A.M.; Lunsford, L.D.; Flickinger, J.C.; Bloomer, W.D.

    1988-01-01

    Gamma knife radiosurgery refers to the treatment procedure that delivers very high dose to a small brain lesion with 201 highly focused beams of Co-60. The hemispheric array of these multiple sources with the sizes of beams ranging from 4, 8, 14, to 18 mm makes the determination of dosimetry characteristics of the radiation field very complex. This paper describes the structures, operations, and dose characteristics of gamma knife. Dosimetry measurements were made using ion chamber, TLD, diode, and films to calibrate the dose outputs of the combination of 201 beams of 4, 8, 14, or 18 mm in diameter irradiating from various directions. Results of measured isodose distribution and dose profiles for the various diameter beams are also presented

  18. Standards in radiation protection at the IAEA Dosimetry Laboratory

    International Nuclear Information System (INIS)

    Czap, L.; Pernicka, F.; Matscheko, G.; Andreo, P.

    1999-01-01

    Approximately 90% of the Secondary Standard Dosimetry Laboratories (SSDLs) provide users with calibrations of radiation protection instruments, and the Agency is making every necessary effort to insure that SSDLs measurements in radiation protection are traceable to Primary Standards. The IAEA provides traceable calibrations of ionization chambers in terms of air kerma at radiation protection levels and ambient dose equivalent calibrations. SSDLs are encouraged to use the calibrations available from the Agency to provide traceability for their radiation protection measurements. Measurements on diagnostic X ray generators have become increasingly important in radiation protection and some SSDLs are involved in such measurements. The IAEA has proper radiation sources available to provide traceable calibrations to the SSDLs in this field, including an X ray unit specifically for mammography dedicated to standardization procedures. The different photon beam qualities and calibration procedures available in the Agency's Dosimetry Laboratory will be described. (author)

  19. Transient thermal effect, nonlinear refraction and nonlinear absorption properties of graphene oxide sheets in dispersion.

    Science.gov (United States)

    Zhang, Xiao-Liang; Liu, Zhi-Bo; Li, Xiao-Chun; Ma, Qiang; Chen, Xu-Dong; Tian, Jian-Guo; Xu, Yan-Fei; Chen, Yong-Sheng

    2013-03-25

    The nonlinear refraction (NLR) properties of graphene oxide (GO) in N, N-Dimethylformamide (DMF) was studied in nanosecond, picosecond and femtosecond time regimes by Z-scan technique. Results show that the dispersion of GO in DMF exhibits negative NLR properties in nanosecond time regime, which is mainly attributed to transient thermal effect in the dispersion. The dispersion also exhibits negative NLR in picosecond and femtosecond time regimes, which are arising from sp(2)- hybridized carbon domains and sp(3)- hybridized matrix in GO sheets. To illustrate the relations between NLR and nonlinear absorption (NLA), NLA properties of the dispersion were also studied in nanosecond, picosecond and femtosecond time regimes.

  20. Microwave absorption properties and mechanism of cagelike ZnO /SiO2 nanocomposites

    Science.gov (United States)

    Cao, Mao-Sheng; Shi, Xiao-Ling; Fang, Xiao-Yong; Jin, Hai-Bo; Hou, Zhi-Ling; Zhou, Wei; Chen, Yu-Jin

    2007-11-01

    In this paper, cagelike ZnO /SiO2 nanocomposites were prepared and their microwave absorption properties were investigated in detail. Dielectric constants and losses of the pure cagelike ZnO nanostructures were measured in a frequency range of 8.2-12.4GHz. The measured results indicate that the cagelike ZnO nanostructures are low-loss material for microwave absorption in X band. However, the cagelike ZnO /SiO2 nanocomposites exhibit a relatively strong attenuation to microwave in X band. Such strong absorption is related to the unique geometrical morphology of the cagelike ZnO nanostructures in the composites. The microcurrent network can be produced in the cagelike ZnO nanostructures, which contributes to the conductive loss.

  1. Introduction to the special issue of Radiation Protection Dosimetry

    International Nuclear Information System (INIS)

    Anon.

    2016-01-01

    This special issue is a collection of peer-reviewed articles derived from presentations at the fourth EPR BioDose Meeting, held in Hanover, NH, USA in 4-8 October 2015. Organised by The International Association of Biological and EPR Radiation Dosimetry (IABERD), this meeting was held in combination with two international conferences (The International Symposium on EPR Dosimetry and Dating and The International Conference on Biodosimetry) and a symposium (The International EPR Society). The primary focus of this conference was on medical response to events in which large numbers of individuals may be exposed to significant levels of ionising radiation; topics included biodosimetry techniques, radiation mitigators, model systems to develop countermeasures, new data from different exposure events and the implication of these methods in a radiological emergency or in terrorist attack scenarios. (authors)

  2. Decomposition of spectra in EPR dosimetry using the matrix method

    International Nuclear Information System (INIS)

    Sholom, S.V.; Chumak, V.V.

    2003-01-01

    The matrix method of EPR spectra decomposition is developed and adapted for routine application in retrospective EPR dosimetry with teeth. According to this method, the initial EPR spectra are decomposed (using methods of matrix algebra) into several reference components (reference matrices) that are specific for each material. Proposed procedure has been tested on the example of tooth enamel. Reference spectra were a spectrum of an empty sample tube and three standard signals of enamel (two at g=2.0045, both for the native signal and one at g perpendicular =2.0018, g parallel =1.9973 for the dosimetric signal). Values of dosimetric signals obtained using the given method have been compared with data obtained by manual manipulation of spectra, and good coincidence was observed. This allows considering the proposed method as potent for application in routine EPR dosimetry

  3. Radiation dosimetry onboard the International Space Station ISS

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Thomas [German Aerospace Center - DLR, Inst. of Aerospace Medicine, Radiation Biology, Cologne (Germany)

    2008-07-01

    Besides the effects of the microgravity environment, and the psychological and psychosocial problems encountered in confined spaces, radiation is the main health detriment for long duration human space missions. The radiation environment encountered in space differs in nature front that on earth, consisting mostly of high energetic ions from protons up to iron, resulting in radiation levels far exceeding the ones encountered on earth for occupational radiation workers. Therefore the determination and the control of the radiation load on astronauts is a moral obligation of the space faring nations. The requirements for radiation detectors in space are very different to that on earth. Limitations in mass, power consumption and the complex nature of the space radiation environment define and limit the overall construction of radiation detectors. Radiation dosimetry onboard the International Space Station (ISS) is accomplished to one part as 'operational' dosimetry aiming for area monitoring of the radiation environment as well as astronaut surveillance. Another part focuses on 'scientific' dosimetry aiming for a better understanding of the radiation environment and its constitutes. Various research activities for a more detailed quantification of the radiation environment as well as its distribution in and outside the space station have been accomplished in the last years onboard the ISS. The paper will focus on the current radiation detectors onboard the ISS, their results, as well as on future planned activities. (orig.)

  4. Radiation dosimetry onboard the International Space Station ISS

    International Nuclear Information System (INIS)

    Berger, Thomas

    2008-01-01

    Besides the effects of the microgravity environment, and the psychological and psychosocial problems encountered in confined spaces, radiation is the main health detriment for long duration human space missions. The radiation environment encountered in space differs in nature front that on earth, consisting mostly of high energetic ions from protons up to iron, resulting in radiation levels far exceeding the ones encountered on earth for occupational radiation workers. Therefore the determination and the control of the radiation load on astronauts is a moral obligation of the space faring nations. The requirements for radiation detectors in space are very different to that on earth. Limitations in mass, power consumption and the complex nature of the space radiation environment define and limit the overall construction of radiation detectors. Radiation dosimetry onboard the International Space Station (ISS) is accomplished to one part as ''operational'' dosimetry aiming for area monitoring of the radiation environment as well as astronaut surveillance. Another part focuses on ''scientific'' dosimetry aiming for a better understanding of the radiation environment and its constitutes. Various research activities for a more detailed quantification of the radiation environment as well as its distribution in and outside the space station have been accomplished in the last years onboard the ISS. The paper will focus on the current radiation detectors onboard the ISS, their results, as well as on future planned activities. (orig.)

  5. Tuning optical and three photon absorption properties in graphene oxide-polyvinyl alcohol free standing films

    Energy Technology Data Exchange (ETDEWEB)

    Karthikeyan, B., E-mail: bkarthik@nitt.edu; Hariharan, S. [Department of Physics, National Institute of Technology, Tiruchirappalli 620 015 (India); Udayabhaskar, R. [Department of Physics, National Institute of Technology, Tiruchirappalli 620 015 (India); Advanced Ceramics and Nanotechnology Laboratory, Department of Materials Engineering, University of Concepcion, Concepcion 4070386 (Chile)

    2016-07-11

    We report the optical and nonlinear optical properties of graphene oxide (GO)-polyvinyl alcohol (PVA) free standing films. The composite polymer films were prepared in ex-situ method. The variation in optical absorption spectra and optical constants with the amount of GO loading was noteworthy from the optical absorption spectroscopic studies. Nonlinear optical studies done at 532 nm using 5 ns laser pulses show three photon absorption like behaviour. Both steady state and time resolved fluorescence studies reveal that the GO was functioning as a pathway for the decay of fluorescence from PVA. This is attributed to the energy level modifications of GO through hydroxyl groups with PVA. Raman spectroscopy also supports the interaction between GO and PVA ions through OH radicals.

  6. Tuning optical and three photon absorption properties in graphene oxide-polyvinyl alcohol free standing films

    International Nuclear Information System (INIS)

    Karthikeyan, B.; Hariharan, S.; Udayabhaskar, R.

    2016-01-01

    We report the optical and nonlinear optical properties of graphene oxide (GO)-polyvinyl alcohol (PVA) free standing films. The composite polymer films were prepared in ex-situ method. The variation in optical absorption spectra and optical constants with the amount of GO loading was noteworthy from the optical absorption spectroscopic studies. Nonlinear optical studies done at 532 nm using 5 ns laser pulses show three photon absorption like behaviour. Both steady state and time resolved fluorescence studies reveal that the GO was functioning as a pathway for the decay of fluorescence from PVA. This is attributed to the energy level modifications of GO through hydroxyl groups with PVA. Raman spectroscopy also supports the interaction between GO and PVA ions through OH radicals.

  7. Report on the Personnel Dosimetry at AB Atomenergi during 1965

    International Nuclear Information System (INIS)

    Edvardsson, K.A.

    1966-10-01

    This report presents the results of the personnel dosimetry at AB Atomenergi during 1965. No doses exceeding the recommendations of ICRP were reported. For AB Atomenergi the average external total body dose during the year was 60 mrem which corresponds to 89.4 manrem. 31200 gamma films and 5850 neutron films were evaluated. 2067 urine analyses and 692 measurements of body activity were made

  8. Report on the Personnel Dosimetry at AB Atomenergi during 1965

    Energy Technology Data Exchange (ETDEWEB)

    Edvardsson, K A

    1966-10-15

    This report presents the results of the personnel dosimetry at AB Atomenergi during 1965. No doses exceeding the recommendations of ICRP were reported. For AB Atomenergi the average external total body dose during the year was 60 mrem which corresponds to 89.4 manrem. 31200 gamma films and 5850 neutron films were evaluated. 2067 urine analyses and 692 measurements of body activity were made.

  9. Transient Analysis and Dosimetry of the Tokaimura Criticality Incident

    International Nuclear Information System (INIS)

    Pain, Christopher C.; Oliveira, Cassiano R.E. de; Goddard, Antony J. H.; Eaton, Matthew D.; Gundry, Sarah; Umpleby, Adrian P.

    2003-01-01

    This paper describes research on the application of the finite element transient criticality (FETCH) code to modeling and neutron dosimetry of the Tokaimura criticality incident. FETCH has been developed to model criticality transients in single and multiphase media and is applied here to fissile solution transient criticality. Since the initial transient behavior has different time scales and physics to the longer transient behavior, the transient modeling is divided into two parts: modeling the initial transient over a time scale of seconds in which radiolytic gases and free-surface sloshing play an important role in the transient - this provides information about the dose to workers; and modeling the long-term transient behavior following the initial transient that has a time scale over hours.The neutron dosimetry of worker A who received the largest dose during the Tokaimura criticality incident is also investigated here. This dose was received mainly in the first few seconds of the ensuing nuclear criticality transient. In addition to the multiorgan dosimetry of worker A, this work provides a method of helping to evaluate the yield in the initial phase of the criticality incident; it also shows how kinetic simulations can be calibrated so that they can be applied to investigate the physics behind the incident

  10. Calculations in cytogenetic dosimetry by means of the dosgen program

    International Nuclear Information System (INIS)

    Garcia Lima, O.; Zerquera, J.T.

    1996-01-01

    The DOSGEN program sums up the different calculations routing that are more often used in cytogenetic dosimetry. It can be implemented in a compatible IBM PC by cytogenetic experts having a basic knowledge of computing. The programs has been successfully applied using experimental data and its advantages have been acknowledge by Latin American and Asian Laboratories dealing with this medical branch. The program is written in Pascal Language and requires 42 K bytes

  11. The zero-power basis of fast reactor dosimetry

    International Nuclear Information System (INIS)

    Sanders, J.E.

    1978-06-01

    Predictions of reaction rates, atomic displacements, and gamma-ray energy deposition in the Prototype Fast Reactor are based on cross-section data and calculation methods validated against the results of zero-power experiments. The paper reviews work in Zebra relevant to this dosimetry, including neutron spectrometry, power mapping, foil activations within core heterogeneities, and measurements with thermoluminescent detectors. Comparisons of experiment and calculation are discussed in relation to the accuracies required to meet materials testing objectives. (author)

  12. The zero-power basis of fast reactor dosimetry

    International Nuclear Information System (INIS)

    Sanders, J.E.

    1978-06-01

    Predictions of reaction rates, atomic displacements, and gamma-ray energy deposition in the Prototype Fast Reactor are based on cross-section data and calculation methods validated against the results of zero-power experiments. The paper reviews work in Zebra relevant to this dosimetry, including neutron spectrometry, power mapping, foil activations within core heterogeneities, and measurements with thermoluminescent detectors. Comparisons of experiment and calculation are discussed in relation to the accuracies required to meet material testing objectives. (author)

  13. Personal dosimetry performance testing in the United States

    International Nuclear Information System (INIS)

    Soares, Christopher G.

    2008-01-01

    The basis for personal dosimetry performance testing in the United States is ANSI/HPS N13.11. Now in it's fourth edition, this standard has been in place since 1983. Testing under this standard is administered by the National Voluntary Laboratory Accreditation Program (NVLAP), and accreditation of dosimetry processors under this program is required by U.S. Nuclear Regulatory Commission (NRC) regulations. The U.S. Department of Energy (DOE) also maintains a testing program for its laboratories and contractors, administered by the Department of Energy Laboratory Accreditation Program (DOELAP). One of the goals of this current revision was the modification of ANSI/HPS N13.11 to allow acceptance by both testing programs in order to bring harmonization to U.S. personal dosemeter performance testing. The testing philosophy of ANSI/HPS N13.11 has always combined elements of type testing and routine performance testing and is thus different from the testing philosophy used in the rest of the world. In this paper, the history of performance testing in the U.S. is briefly reviewed. Also described is the revision that produced the fourth edition of this standard, which has taken place over the last three years (2005-2008) by a working group representing national standards laboratories, government laboratories, the military, dosimetry vendors, universities and the nuclear power industry. (author)

  14. Preparation and oil absorption properties of magnetic melamine sponge

    Science.gov (United States)

    Lei, LUO; Jia-qi, HU; Na, LV

    2017-12-01

    The magnetic melamine sponge (MS-Fe3O4) with magnetic response and high hydrophobicity was fabricated by two-step method. First, the magnetic nano-particles were fixed on the skeleton of melamine sponge (MS) using 3-hydroxytyramine hydrochloride and 1-dodecanethiol, then hydrophobicity modified with octadecyltrichlorosilane (OTS). The structures and chemical compositions of MS and MS-Fe3O4 were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The wettability of the sample was obtained by using contact angle analysis system. MS-Fe3O4 endowed with outstanding selectivity and excellent oil absorption capacities, which can be widely used in absorbing various sorts of oil. The oil absorption capacities for crude oil, diesel oil, lubricating oil, soybean oil and peanut oil were 71g/g, 51g/g, 62g/g, 54g/g, 57g/g. In addition, MS-Fe3O4 showed excellent recyclability which can be forecasted as an ideal candidate for oil-water separation.

  15. Neutron dosimetry in containment of a pressurized water reactor utilizing the Panasonic UD-802 dosimetry system

    International Nuclear Information System (INIS)

    Kralick, S.C.

    1984-01-01

    The Panasonic UD-802 dosimeter was evaluated as a potential neutron dosimeter for use in containment of a PWR. The Panasonic UD-802 dosimeter, although designed as a beta and gamma dosimeter, is also sensitive to neutrons. UD-802 dosimeters were mounted on polyethylene phantoms and irradiated to known doses at selected locations in containment. The known neutron dose equivalents were determined based on remmeter dose rate measurements and stay times. The thermoluminescent response of the dosimeters and the known neutron dose equivalents were used to obtain a calibration factor at each location. The average calibration factor was 3.7 (unit of dosimeter response per mrem) and all calibration factors were within +-30% of this mean value. The dosimeter distance from the phantom was found to have minimal effect on the response but the system was directionally dependent, necessitating a correction in the calibration factor. The minimum significant dosimeter response was determined independent of any calibration factor. The minimum significant response of the UD-802 to neutrons is a function of the corresponding gamma exposure rate. It is concluded that the Panasonic UD-802 dosimeter can be used for neutron dosimetry in PWR containment

  16. Neutron dosimetry - A review

    Energy Technology Data Exchange (ETDEWEB)

    Baum, J W

    1955-03-29

    This review summarizes information on the following subjects: (1) physical processes of importance in neutron dosimetry; (2) biological effects of neutrons; (3) neutron sources; and (4) instruments and methods used in neutron dosimetry. Also, possible improvements in dosimetry instrumentation are outlined and discussed. (author)

  17. [The percutaneous absorption of diclofenac].

    Science.gov (United States)

    Riess, W; Schmid, K; Botta, L; Kobayashi, K; Moppert, J; Schneider, W; Sioufi, A; Strusberg, A; Tomasi, M

    1986-07-01

    The percutaneous absorption of diclofenac diethylammonium 1.16% (w/w) in a combination of emulsion cream and gel (Voltaren Emulgel) and of diclofenac sodium 1% (w/w) in a cream formulation (Voltaren cream) was investigated in guinea-pig, rabbit and man. The percutaneous absorption of diclofenac sodium in guinea-pig was 3 to 6% of the dose when the cream formulation in doses of 320, 100 or 40 mg was applied on 10 cm2 of occluded skin and left in place for 6 h. The transdermal delivery of 14C-labelled diclofenac yielded plateau plasma concentrations of radiotracer from 1.5 h after application until removal of the residual cream. Subsequently the steady state drug depots in the skin and muscle tissue were depleted promptly. During daily administration the steady state levels in the muscle tissue in proximity to the application site were about 3 times higher than in distant muscle tissue. By topical application on knee joints of rabbits diclofenac penetrated into the patellar ligament, the adipose corpus and the synovial fluid. In man the percutaneous absorption was 6% of the dose when the Emulgel formulation was spread by 5 mg/cm2 and left for 12 h on non-occluded skin. The pattern of metabolites of diclofenac in human urine was the same after topical and oral administration. In man, upon daily topical administration of 3 times 2.5 g cream formulation (10 mg/cm2) the diclofenac steady state plasma levels were 20 to 40 nmol/l.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Report on the Personnel Dosimetry at AB Atomenergi during 1969

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, J; Wahlberg, T

    1971-05-15

    This report presents the results of personnel dosimetry at AB Atomenergi during 1969. 24,200 gamma films and 3,300 neutron films were evaluated. 770 urine analyses and 1,150 measurements of body activity were made. The external total body gamma dose for all employees (quarterly doses < 100 mrem are not reported) corresponds to 136 manrem. The highest external total body gamma dose during 1969 to one person was 4,800 mrem

  19. Report on the Personnel Dosimetry at AB Atomenergi during 1968

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, J; Wahlberg, T

    1969-08-15

    This report presents the results of personnel dosimetry at AB Atomenergi during 1968. 25600 gamma films and 3900 neutron films were evaluated. 1737 urine analyses and 1066 measurements of body activity were made. The external total body gamma dose for all employees (quarterly doses {<=} 100 mrem are not reported) corresponds to 136 manrem. The highest external total body gamma dose during 1968 to one person was 4,500 mrem.

  20. Report on the Personnel Dosimetry at AB Atomenergi during 1967

    International Nuclear Information System (INIS)

    Carlsson, J.; Wahlberg, T.

    1968-12-01

    This report presents the results of personnel dosimetry at AB Atomenergi during 1967. The external total body gamma dose for all employees (quarterly doses ≤ 100 mrem are not reported) corresponds to 140 manrem. The highest external total body gamma dose during 1967 to one person was 5700 mrem. 24700 gamma films and 3900 neutron films were evaluated. 1988 urine analyses and 989 measurements of body activity were made

  1. Report on the Personnel Dosimetry at AB Atomenergi during 1967

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, J; Wahlberg, T

    1968-12-15

    This report presents the results of personnel dosimetry at AB Atomenergi during 1967. The external total body gamma dose for all employees (quarterly doses {<=} 100 mrem are not reported) corresponds to 140 manrem. The highest external total body gamma dose during 1967 to one person was 5700 mrem. 24700 gamma films and 3900 neutron films were evaluated. 1988 urine analyses and 989 measurements of body activity were made.

  2. Intercomparison on the usage of computational codes in radiation dosimetry

    International Nuclear Information System (INIS)

    Ilic, R.; Pesic, M.; Pavlovic, R.

    2003-01-01

    SRNA-2KG software package was modified for this work to include necessary input and output data and for predicted voxelized geometry and dosimetry. SRNA is a Monte Carlo code developed for applications in proton transport, radiotherapy and dosimetry. Protons within energy range from 100 keV to 250 MeV with predefined spectra are transported in 3D geometry through material zones confined by planes and second order surfaces or in 3D voxelized geometry. The code can treat proton transport in a few hundred different materials including elements from Z=1 to Z=98. Simulation of proton transport is based on the multiple scattering theory of charged particles and on the model for compound nucleus decay

  3. Preparation and Sound Absorption Properties of a Barium Titanate/Nitrile Butadiene Rubber–Polyurethane Foam Composite with Multilayered Structure

    Science.gov (United States)

    Jiang, Xueliang; Yang, Zhen; Wang, Zhijie; Zhang, Fuqing; You, Feng

    2018-01-01

    Barium titanate/nitrile butadiene rubber (BT/NBR) and polyurethane (PU) foam were combined to prepare a sound-absorbing material with an alternating multilayered structure. The effects of the cell size of PU foam and the alternating unit number on the sound absorption property of the material were investigated. The results show that the sound absorption efficiency at a low frequency increased when decreasing the cell size of PU foam layer. With the increasing of the alternating unit number, the material shows the sound absorption effect in a wider bandwidth of frequency. The BT/NBR-PU foam composites with alternating multilayered structure have an excellent sound absorption property at low frequency due to the organic combination of airflow resistivity, resonance absorption, and interface dissipation. PMID:29565321

  4. Preparation and Sound Absorption Properties of a Barium Titanate/Nitrile Butadiene Rubber–Polyurethane Foam Composite with Multilayered Structure

    Directory of Open Access Journals (Sweden)

    Xueliang Jiang

    2018-03-01

    Full Text Available Barium titanate/nitrile butadiene rubber (BT/NBR and polyurethane (PU foam were combined to prepare a sound-absorbing material with an alternating multilayered structure. The effects of the cell size of PU foam and the alternating unit number on the sound absorption property of the material were investigated. The results show that the sound absorption efficiency at a low frequency increased when decreasing the cell size of PU foam layer. With the increasing of the alternating unit number, the material shows the sound absorption effect in a wider bandwidth of frequency. The BT/NBR-PU foam composites with alternating multilayered structure have an excellent sound absorption property at low frequency due to the organic combination of airflow resistivity, resonance absorption, and interface dissipation.

  5. Preparation and Sound Absorption Properties of a Barium Titanate/Nitrile Butadiene Rubber-Polyurethane Foam Composite with Multilayered Structure.

    Science.gov (United States)

    Jiang, Xueliang; Yang, Zhen; Wang, Zhijie; Zhang, Fuqing; You, Feng; Yao, Chu

    2018-03-22

    Barium titanate/nitrile butadiene rubber (BT/NBR) and polyurethane (PU) foam were combined to prepare a sound-absorbing material with an alternating multilayered structure. The effects of the cell size of PU foam and the alternating unit number on the sound absorption property of the material were investigated. The results show that the sound absorption efficiency at a low frequency increased when decreasing the cell size of PU foam layer. With the increasing of the alternating unit number, the material shows the sound absorption effect in a wider bandwidth of frequency. The BT/NBR-PU foam composites with alternating multilayered structure have an excellent sound absorption property at low frequency due to the organic combination of airflow resistivity, resonance absorption, and interface dissipation.

  6. The Martin Marietta Energy Systems personnel neutron dosimetry program

    International Nuclear Information System (INIS)

    McMahan, K.L.

    1991-01-01

    Martin Marietta Energy Systems, Inc. (Energy Systems), manages five sites for the US Department of Energy. Personnel dosimetry for four of the five sites is coordinated through a Centralized External Dosimetry System (CEDS). These four sites are the Oak Ridge National Laboratory (ORNL), the Oak Ridge Y-12 Plant (Y-12), the Oak Ridge K-25 Site (K-25), and the Paducah Gaseous Diffusion Plant (PGDP). The fifth Energy Systems site, Portsmouth Gaseous Diffusion Plant, has an independent personnel dosimetry program. The current CEDS personnel neutron dosimeter was first issued in January 1989, after an evaluation and characterization of the dosimeters' response in the workplaces was performed. For the workplace characterization, Energy Systems contracted with Pacific Northwest Laboratory (PNL) to perform neutron measurements at selected locations at ORNL and Y-12. K-25 and PGDP were not included because their neutron radiation fields were similar to others already planned for characterization at ORNL and Y-12. Since the initial characterization, PNL has returned to Oak Ridge twice to perform follow up measurements, and another visit is planned in the near future

  7. Dosimetry for photo-coagulation by the use of autofluorescence

    Science.gov (United States)

    Brodzinski, T.

    1989-01-01

    A basic problem when using lasers in medicine is that of dosimetry. The definition of the terms dose, effective value etc. will be dealt with in Chapter 2. This chapter is intended to give an insight into the problems of basic dosimetry and its technical realization within the field of photocoagulation, an established method used to treat the retina, or some skin diseases. Until now the coagulation process was assessed to be completed when the irradiated area became blanched. However in terms of dosimetry, it must be possible to predict or at least to monitor the biological effect using well-defined parameters for the laser or in achieving an objective measure for a feedback loop. In the case of coagulation, a prediction in this form is not possible. There are two ways of pro- ceeding further see Fig. 1. One can either determine the physical effect, i.e. temperature, by some kind of sensors, or even better, use some biological effect as a direct measure of the effective dose applied.

  8. Dosimetry with the scanned proton beam on the PSI gantry

    International Nuclear Information System (INIS)

    Coray, A.; Pedroni, E.; Boehringer, T.; Lin, S.; Lomax, T.; Goitein, G.

    2002-01-01

    Full text: The irradiation facility at PSI is designed for the treatment of deep seated tumours with a proton beam energy of up to 270 MeV. The spot scanning technique, which uses a proton pencil beam applied to the patient, is performed on a compact isocentric gantry. An optimal three-dimensional conformation of the dose distribution to the target volume can be realized. A fast steering system and a redundant interlock system are in operation. The dose delivery is controlled by a parallel plate transmission chamber, which is calibrated in terms of number of protons per monitor unit. The therapy planning is based on an empirical model, which takes into account attenuation of primary protons and losses outside the primary beam through secondary products. The therapy plan predicts an absolute dose. The calibration of the primary monitor is done using a reference thimble ionization chamber inside a homogeneous geometrical dose volume. The reference system is calibrated in a cobalt field at the national office of metrology in terms of absorbed dose to water. The dosimetry protocol used up to last year was based on the ICRU Report Nr. 59, we have switched to the IAEA Code of Practice starting this beam period. Data on the monitor calibration for various energies and using two different reference systems will be shown. The calibration of the beam monitor using a Faraday Cup in the static pencil beam results in a good agreement with the ionization chamber measurements, with a deviation of less than 1%. Following the daily setup of the machine, an extensive quality control and safety check of the whole system is performed. The daily dosimetry quality assurance program includes: measurement of dose rate and monitor ratios; check of the beam position monitors; measurement of a depth dose curve; dose measurement in a regular dose field. The doses measured daily in a regular scanned field show a standard deviation of about 1 %. Further daily checks results, which illustrate

  9. Organization of the internal dosimetry in the Spanish nuclear facilities

    International Nuclear Information System (INIS)

    Manchena, P.; Soliet, E.

    1998-01-01

    From the beginning of the exploitation of the nuclear energy of Espanna, the nuclear facilities have had Services of Personal Dosimetry with the appropriate means to determine the dose. so much internal as external, of the personnel that mentioned facilities works. All the nuclear power stations use advanced systems of teams with object of detecting the radionuclides incorporation in the organism and calculation programs based on the recent recommendations of the International Commission of Radiological Protection (ICRP) for the determination of the derived doses

  10. The Schwarzschild effect of the dosimetry film Kodak EDR 2.

    Science.gov (United States)

    Djouguela, A; Kollhoff, R; Rubach, A; Harder, D; Poppe, B

    2005-11-07

    The magnitude of the Schwarzschild effect or failure of the reciprocity law has been experimentally investigated for the dosimetry film EDR 2 from Kodak. When the dose rate applied to achieve a given dose was reduced by a factor of 12, the net optical density was reduced by up to 5%. The clinical importance of this effect is negligible as long as the films are calibrated at a value of the dose rate approximately representative of the dose rates occurring in the target volume, but in target regions of strongly reduced dose rate the Schwarzschild effect should be allowed for by a correction of the net optical density.

  11. 100 years of solid state dosimetry and radiation protection dosimetry

    International Nuclear Information System (INIS)

    Bartlett, David T.

    2008-01-01

    The use of solid state detectors in radiation dosimetry has passed its 100th anniversary. The major applications of these detectors in radiation dosimetry have been in personal dosimetry, retrospective dosimetry, dating, medical dosimetry, the characterization of radiation fields, and also in microdosimetry and radiobiology research. In this introductory paper for the 15th International Conference, I shall speak of the history of solid state dosimetry and of the radiation measurement quantities that developed at the same time, mention some landmark developments in detectors and applications, speak a bit more about dosimetry and measurement quantities, and briefly look at the past and future

  12. Course of training in Specific internal dosimetry for the patient

    International Nuclear Information System (INIS)

    Rojo, A.M.; Michelin, S.C.; Gomez P, I.M.

    2006-01-01

    In this work the experience obtained in a course organized in Argentina to qualify professionals in the radiopharmaceutical dosimetry using the methodology MIRD and the patient's images is presented. The motivation to carry out it was based on the continuous development of new radiopharmaceuticals with therapeutic purposes that makes necessary the knowledge of the distribution of the absorbed dose to be able to establish the dose-response relationship. The main objective was the study of the biokinetic model and those techniques available that starting from images can contribute information of specific parameters of the patient to calculate with more accuracy the doses in the tumor and in different organs. In the design of the program of this course it was considered to approach the different focuses for the calculation of specific dose of the patient and includes the following topics: the patient's radiological protection, new concepts in damages by radiations (bystander effect), methodology for the internal dosimetry by radiopharmaceuticals, dosimetric systems (MIRD/ICRP), revision of the physical phantoms, design of kinetic studies, compartmental models, calculation tools and the demonstration of the programs SAAM and OLINDA; calculation of activity starting from the patient's images (planar and SPECT). Principles of the gamma camera: the dispersed radiation, calculation of the activity with planar images, the attenuation, correction of the dispersed radiation, collimation problems. SPECT: the common method of reconstruction, basic principles, method of filtered over head projection and iterative methods (MLEM/OSEM), measurement of the attenuation maps, problems of the penetration in the collimator (I-131, I-123), effects of partial volume, incorporation of corrections in an iterative reconstruction. Dosimetry in bone marrow, discussion of study cases of new radiopharmaceuticals. Internal dosimetry in small scale for electrons and photons. Perspectives of the

  13. Effects of dose fractionation on the response of alanine dosimetry

    International Nuclear Information System (INIS)

    Lundahl, Brad; Logar, John; Desrosiers, Marc; Puhl, James

    2014-01-01

    Alanine dosimetry is well established as a transfer standard and is becoming more prevalently used in routine dosimetry systems for radiation processing. Many routine measurement applications in radiation processing involve absorbed dose measurements resulting from fractioned exposures to ionizing radiation. Fractioning of absorbed dose is identified as an influence quantity (ISO/ASTM, 2013). This paper reports on study results of absorbed dose fractioning characteristics of alanine for gamma and high energy electron beam radiation sources. The results of this study indicate a radiation response difference due to absorbed dose fractioning in response can be observed after four fractionations for high-energy electron beams and no difference up to seven fractions for gamma rays using an ANOVA evaluation method. - Highlights: • Fractioning effects signaled in electron beam using an ANOVA at 6 equal increments. • Fractioning effects not signaled in gamma using an ANOVA up to 7 equal increments. • Insensitivity of alanine to dose fractioning indicates nominal impact on calibration

  14. Proceedings of the second conference on radiation protection and dosimetry

    International Nuclear Information System (INIS)

    Swaja, R.E.; Sims, C.S.

    1988-11-01

    The Second Conference on Radiation Protection and Dosimetry was held during October 31--November 3, 1988, at the Holiday Inn, Crowne Plaza Hotel in Orlando, Florida. This meeting was designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection and providing them with sufficient information to evaluate their programs. To facilitate meeting these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection was prepared. General topics considered in the technical sessions included external dosimetry, internal dosimetry, calibration, standards and regulations, instrumentation, accreditation and test programs, research advances, and applied program experience. In addition, special sessions were held to afford attendees the opportunity to make short presentations of recent work or to discuss topics of general interest. This document provides a summary of the conference technical program and a partial collection of full papers for the oral presentations in order of delivery. Individual papers were processed separately for the data base

  15. Proceedings of the second conference on radiation protection and dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Swaja, R. E.; Sims, C. S. [eds.

    1988-11-01

    The Second Conference on Radiation Protection and Dosimetry was held during October 31--November 3, 1988, at the Holiday Inn, Crowne Plaza Hotel in Orlando, Florida. This meeting was designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection and providing them with sufficient information to evaluate their programs. To facilitate meeting these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection was prepared. General topics considered in the technical sessions included external dosimetry, internal dosimetry, calibration, standards and regulations, instrumentation, accreditation and test programs, research advances, and applied program experience. In addition, special sessions were held to afford attendees the opportunity to make short presentations of recent work or to discuss topics of general interest. This document provides a summary of the conference technical program and a partial collection of full papers for the oral presentations in order of delivery. Individual papers were processed separately for the data base.

  16. RENEB - Running the European Network of biological dosimetry and physical retrospective dosimetry.

    Science.gov (United States)

    Kulka, Ulrike; Abend, Michael; Ainsbury, Elizabeth; Badie, Christophe; Barquinero, Joan Francesc; Barrios, Lleonard; Beinke, Christina; Bortolin, Emanuela; Cucu, Alexandra; De Amicis, Andrea; Domínguez, Inmaculada; Fattibene, Paola; Frøvig, Anne Marie; Gregoire, Eric; Guogyte, Kamile; Hadjidekova, Valeria; Jaworska, Alicja; Kriehuber, Ralf; Lindholm, Carita; Lloyd, David; Lumniczky, Katalin; Lyng, Fiona; Meschini, Roberta; Mörtl, Simone; Della Monaca, Sara; Monteiro Gil, Octávia; Montoro, Alegria; Moquet, Jayne; Moreno, Mercedes; Oestreicher, Ursula; Palitti, Fabrizio; Pantelias, Gabriel; Patrono, Clarice; Piqueret-Stephan, Laure; Port, Matthias; Prieto, María Jesus; Quintens, Roel; Ricoul, Michelle; Romm, Horst; Roy, Laurence; Sáfrány, Géza; Sabatier, Laure; Sebastià, Natividad; Sommer, Sylwester; Terzoudi, Georgia; Testa, Antonella; Thierens, Hubert; Turai, Istvan; Trompier, François; Valente, Marco; Vaz, Pedro; Voisin, Philippe; Vral, Anne; Woda, Clemens; Zafiropoulos, Demetre; Wojcik, Andrzej

    2017-01-01

    A European network was initiated in 2012 by 23 partners from 16 European countries with the aim to significantly increase individualized dose reconstruction in case of large-scale radiological emergency scenarios. The network was built on three complementary pillars: (1) an operational basis with seven biological and physical dosimetric assays in ready-to-use mode, (2) a basis for education, training and quality assurance, and (3) a basis for further network development regarding new techniques and members. Techniques for individual dose estimation based on biological samples and/or inert personalized devices as mobile phones or smart phones were optimized to support rapid categorization of many potential victims according to the received dose to the blood or personal devices. Communication and cross-border collaboration were also standardized. To assure long-term sustainability of the network, cooperation with national and international emergency preparedness organizations was initiated and links to radiation protection and research platforms have been developed. A legal framework, based on a Memorandum of Understanding, was established and signed by 27 organizations by the end of 2015. RENEB is a European Network of biological and physical-retrospective dosimetry, with the capacity and capability to perform large-scale rapid individualized dose estimation. Specialized to handle large numbers of samples, RENEB is able to contribute to radiological emergency preparedness and wider large-scale research projects.

  17. Clinical dosimetry

    International Nuclear Information System (INIS)

    Rassow, J.

    1973-01-01

    The main point of this paper on clinical dosimetry which is to be understood here as application of physical dosimetry on accelerators in medical practice, is based on dosimetric methodics. Following an explanation of the dose parameters and description of the dose distribution important for clinical practice as well as geometric irradiation parameters, the significance of a series of physical parameters such as accelerator energy, surface energy of average stopping power etc. is dealt with in detail. Following a section on field homogenization with bremsstrahlung and electron radiation, details on dosimetry in clinical practice are given. Finally, a few problems of dosemeter or monitor calibration on accelerators are described. The explanations are supplemented by a series of diagrams and tables. (ORU/LH) [de

  18. Intrinsic dosimetry. Properties and mechanisms of thermoluminescence in commercial borosilicate glass

    Energy Technology Data Exchange (ETDEWEB)

    Clark, Richard A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2012-10-01

    Intrinsic dosimetry is the method of measuring total absorbed dose received by the walls of a container holding radioactive material. By considering the total absorbed dose received by a container in tandem with the physical characteristics of the radioactive material housed within that container, this method has the potential to provide enhanced pathway information regarding the history of the container and its radioactive contents. The latest in a series of experiments designed to validate and demonstrate this newly developed tool are reported. Thermoluminescence (TL) dosimetry was used to measure dose effects on raw stock borosilicate container glass up to 70 days after gamma ray, x-ray, beta particle or ultraviolet irradiations at doses from 0.15 to 20 Gy. The TL glow curve when irradiated with 60Co was separated into five peaks: two relatively unstable peaks centered near 120 and 165°C, and three relatively stable peaks centered near 225, 285, and 360°C. Depending on the borosilicate glass source, the minimum measurable dose using this technique is 0.15-0.5 Gy, which is roughly equivalent to a 24 hr irradiation at 1 cm from a 50-165 ng source of 60Co. Differences in TL glow curve shape and intensity were observed for the glasses from different geographical origins. These differences can be explained by changes in the intensities of the five peaks. Electron paramagnetic resonance (EPR) and multivariate statistical methods were used to relate the TL intensity and peaks to electron/hole traps and compositional variations.

  19. Phantom positioning variation in the Gamma Knife® Perfexion dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Nathalia Almeida; Potiens, Maria da Penha Albuquerque [Instituto de Pesquisas Energeticas e Nucleres (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Saraiva, Crystian [Hospital do Coracao, Sao Paulo, SP (Brazil)

    2015-07-01

    The use of small volume ionization chamber has become required for the dosimetry of equipment that use small radiation fields. A pinpoint ionization chamber is ideal for the dosimetry of a Gamma Knife® Perfexion (GKP) unit. In this work, this chamber was inserted into the phantom, and measurements were performed with the phantom in different positions, in order to verify if the change in the phantom positioning affects the dosimetry of the GKP. Three different phantom positions were performed. The variation in the result is within the range allowed for the dosimetry of a GKP equipment. (author)

  20. Synthesis, multi-nonlinear dielectric resonance and electromagnetic absorption properties of hcp-cobalt particles

    International Nuclear Information System (INIS)

    Wen, Shulai; Liu, Ying; Zhao, Xiuchen; Cheng, Jingwei; Li, Hong

    2014-01-01

    Hcp-cobalt particles were successfully prepared by a liquid phase reduction method, and the microstructure, static magnetic properties, electromagnetic and microwave absorption properties of the cobalt particles with irregular shape were investigated in detail. The measured results indicate that the saturation magnetization was less than that of hcp-Co single crystals, and the coercivity was larger than that of bulk cobalt crystal. The permittivity presents multi-nonlinear dielectric resonance, which may result from the irregular shape containing parts of cutting angle of dodecahedron of cobalt particles. The real part of permeability decreases with the frequency, and the imaginary part has a wide resonant peak. The paraffin-based composite containing 70 wt% cobalt particles possessed strong absorption characteristics with a minimum RL of −38.97 dB at 10.81 GHz and an absorption band with RL under −10 dB from 8.72 to 13.26 GHz when the thickness is 1.8 mm, which exhibits excellent microwave absorption in middle and high frequency. The architectural design of material morphologies is important for improving microwave absorption properties toward future application. - Highlights: • Hcp-cobalt particles were prepared by a liquid phase reduction method. • The saturation magnetization was less than that of hcp-Co single crystals. • The permittivity presents multi-nonlinear dielectric resonance. • The real part of permeability decreases with frequency, and the imaginary part presents a wide resonant peak. • The paraffin-based composite possessed a minimum RL of −38.97 dB at 10.81 GHz

  1. Dosimetry system 1986

    International Nuclear Information System (INIS)

    Woolson, William A.; Egbert, Stephen D.; Gritzner, Michael L.

    1987-01-01

    In May 1983, the authors proposed a dosimetry system for use by the Radiation Effects Research Foundation (RERF) that would incorporate the new findings and calculations of the joint United States - Japan working groups on the reassessment of A-bomb dosimetry. The proposed dosimetry system evolved from extensive discussions with RERF personnel, numerous meetings of the scientists from Japan and the United States involved in the dosimetry reassessment research, and requirements expressed by epidemiologists and radiobiologists on the various review panels. The dosimetry system proposed was based on considerations of the dosimetry requirements for the normal work of RERF and for future research in radiobiology, the computerized input data on A-bomb survivors available in the RERF data base, the level of detail, precision, and accuracy of various components of the dosimetric estimates, and the computer resources available at RERF in Hiroshima. These discussions and our own experience indicated that, in light of the expansion of computer and radiation technologies and the desire for more detail in the dosimetry, an entirely new approach to the dosimetry system was appropriate. This resulted in a complete replacement of the T65D system as distinguished from a simpler approach involving a renormalization of T65D parameters to reflect the new dosimetry. The proposed dosimetry system for RERF and the plan for implementation was accepted by the Department of Energy (DOE) Working Group on A-bomb Dosimetry chaired by Dr. R.F. Christy. The dosimetry system plan was also presented to the binational A-bomb dosimetry review groups for critical comment and was discussed at joint US-Japan workshop. A prototype dosimetry system incorporating preliminary dosimetry estimates and applicable to only a limited set of A-bomb survivors was installed on the RERF computer system in the fall of 1984. This system was successfully operated at RERF and provided an initial look at the impact of

  2. The Radiotherapy Dosimetry Audit System In the UK

    International Nuclear Information System (INIS)

    Thwaites, D.I.

    1999-01-01

    Two national radiotherapy dosimetry intercomparisons have been earned out in the UK, involving all radiotherapy institutes. The first was concerned with megavoltage photon beams and looked at beam calibration and simple three-field planned distributions in a geometric phantom. The intercomparisons were carried out by an independent intercomparison physicist visiting each department in turn and making measurements with ion chambers, following a fixed protocol. The beam calibration intercomparison was earned out on every 60 C o beam and every MV x-ray beam, whilst the planned comparisons were carried out on one beam only. The plans included effects of wedges, oblique incidence and inhomogeneities. The study was unfunded and took a significant time (1988-1991) to cover the 65 or so centres. It was followed up by a national electron dosimetry intercomparison which was fended (Department of Health) and which ran from 1994-1996. This audited three electron beam energies in each centre (depth dose, beam energy, dose calibration) and also included a follow-up of the original photon beam intercomparison. In general these studies showed good consistency of dosimetry across the UK centres, with mean (measured/locally stated) doses being close to unity and standard deviations of the distributions of values being approx. 1.5 and 1% for photons, 1.8% for electrons for beam calibration and 2.5-3.5% for the planned multi-beam situations. 97-100% of measurements were within the pre-set 3% tolerance for beam calibration and around 90% of the measurements within a pre-set 5% tolerance for planned situations. The studies did highlight some areas where increased on Q A could provide benefits. In particular the photon intercomparison discovered one 60 C o unit mis calibration which led to national recommendations for the implementation of Quality Systems in radiotherapy departments

  3. Sound Absorption and Friction Properties of Nano-Lotus Leaf Coated Concrete for Rigid Pavement

    Directory of Open Access Journals (Sweden)

    Marcelo GONZALEZ

    2016-09-01

    Full Text Available This paper presents the feasibility of superhydrophobic films to create the nano-lotus leaf effect on concrete surface and their influence on sound absorption and friction properties of concrete for application in rigid pavements. The study involved an evaluation of nanomaterials at the laboratory scale to analyze the effects of microtexture modification on the friction and sound absorption of concrete pavement. A number of laboratory specimens were produced by applying different amounts of nano-lotus leaf coating on the top of the textured concrete surface. The British pendulum test was used to measure the friction number, and an impedance tube was used to determine the sound absorption coefficient. Laboratory results indicate that nano-lotus leaf coated concrete can maintain the required friction property for rigid pavement, but may not increase the noise absorption. Further research must be carried out to determine possible benefit of the lotus leaf effect for reducing hydroplaning, particularly during heavy rainfall.DOI: http://dx.doi.org/10.5755/j01.ms.22.3.7638

  4. Microwave absorption properties of barium titanate/epoxide resin composites

    International Nuclear Information System (INIS)

    Chen Xiaodong; Wang Guiqin; Duan Yuping; Liu Shunhua

    2007-01-01

    Nano-barium titanate (BT) was prepared by a sol-gel method. The prepared powders were characterized by x-ray powder diffraction and transmission electron microscopy. The complex relative dielectric permittivity (ε = ε' - jε-prime) and magnetic permeability (μ = μ' - jμ-prime) of the BT powders were measured in the frequency range 8 ∼ 18 GHz. The BT/epoxide resin (EP) composite with different volume contents was investigated. The effects of thickness on the BT/EP composite were studied. It was found that an optimum thickness and contents of the absorber can yield the maximum reflection loss which could be obtained over a broad frequency region in the X and Ku bands. Our results indicate that BT could be a promising microwave absorption material

  5. Applications of gel dosimetry

    International Nuclear Information System (INIS)

    Ibbott, Geoffrey S

    2004-01-01

    Gel dosimetry has been examined as a clinical dosimeter since the 1950s. During the last two decades, however, a rapid increase in the number of investigators has been seen, and the body of knowledge regarding gel dosimetry has expanded considerably. Gel dosimetry is still considered a research project, and the introduction of this tool into clinical use is proceeding slowly. This paper will review the characteristics of gel dosimetry that make it desirable for clinical use, the postulated and demonstrated applications of gel dosimetry, and some complications, set-backs, and failures that have contributed to the slow introduction into routine clinical use

  6. Techniques used in CAPRI for the dosimetry of γ radiations and electron beams

    International Nuclear Information System (INIS)

    Laizier, J.

    1980-01-01

    The radiation sources of CAPRI are: Pagure - 60 Co - 20Kcie, Poseidon - 60 Co - 1MCie (presently the activity is 200 Kcie), Vulcain - e - - 3MeV (variable from 0.5 MeV) - 1mA, Promethee - e - - 300 kV - 100 mA. The activities of CAPRI are research and development in industrial applications of irradiation, pilot and small scale production, irradiation (sterilization), nuclear qualification. Dosimetry techniques are: plastic dosimetry, chemical dosimetry, films [fr

  7. Variations in Spectral Absorption Properties of Phytoplankton, Non-algal Particles and Chromophoric Dissolved Organic Matter in Lake Qiandaohu

    Directory of Open Access Journals (Sweden)

    Liangliang Shi

    2017-05-01

    Full Text Available Light absorption by phytoplankton, non-algal particles (NAP and chromophoric dissolved organic matter (CDOM was investigated at 90 sites of a clear, deep artificial lake (Lake Qiandaohu to study natural variability of absorption coefficients. Our study shows that CDOM absorption is a major contributor to the total absorption signal in Lake Qiandaohu during all seasons, except autumn when it has an equivalent contribution as total particle absorption. The exponential slope of CDOM absorption varies within a narrow range around a mean value of 0.0164 nm−1 ( s d = 0.00176 nm−1. Our study finds some evidence for thIS autochthonous production of CDOM in winter and spring. Absorption by phytoplankton, and therefore its contribution to total absorption, is generally greatest in spring, suggesting that phytoplankton growth in Lake Qiandaohu occurs predominantly in the spring. Phytoplankton absorption in freshwater lakes generally has a direct relationship with chlorophyll-a concentration, similar to the one established for open ocean waters. The NAP absorption, whose relative contribution to total absorption is highest in summer, has a spectral shape that can be well fitted by an exponential function with an average slope of 0.0065 nm−1 ( s d = 0.00076 nm−1. There is significant spatial variability present in the summer of Lake Qiandaohu, especially in the northwestern and southwestern extremes where the optical properties of the water column are strongly affected by the presence of allochthonous matter. Variations in the properties of the particle absorption spectra with depths provides evidence that the water column was vertically inhomogeneous and can be monitored with an optical measurement program. Moreover, the optical inhomogeneity in winter is less obvious. Our study will support the parameterization of the Bio-optical model for Lake Qiandaohu from in situ or remotely sensing aquatic color signals.

  8. Participation of the regional reference center for dosimetry of Argentina in the personnel dosimetry intercomparison for Latin America

    International Nuclear Information System (INIS)

    Alvarez, P.; Lindner, C.; Montano, R.G.; Saravi, M.

    1998-01-01

    Full text: A Regional Personnel Dosimetry Intercomparison was organized in the Regional Reference Center for Dosimetry (CRRD), in agreement with the International Atomic Energy Agency (IAEA) and the Nuclear Regulatory Authority (ARN), with the participation of 9 countries of Latin America. For dosimeter irradiations, X-ray, 60 Co γ-ray and 137 Cs γ-ray beams were used during the intercomparison. The air kerma rate was measured with the Secondary Standard NE 2560 and NE 2561 ionisation chamber. In compliance with ISO 4037 guideline, the wide spectrum series W60, W110 and W200 for the X-ray irradiations were chosen, determining their quality by the HVL method. Prior to the intercomparison, these beams were checked by the Physikalish Technische Bundesanstalt (PTB) using thermoluminescence dosimeters 'pill box', which were irradiated in air and in ICRU phantom. As result of this check, only one 'X ray beam got a deviation of 7%, while the rest of them were less than 3%. Periodic checks of the beams by a Primary Standard Dosimetry Laboratory such as PTB give reliability to the irradiations performed by this CRRD. (author) [es

  9. Specific absorption rate variation in a brain phantom due to exposure by a 3G mobile phone: problems in dosimetry.

    Science.gov (United States)

    Behari, J; Nirala, Jay Prakash

    2013-12-01

    A specific absorption rate (SAR) measurements system has been developed for compliance testing of personal mobile phone in a brain phantom material contained in a Perspex box. The volume of the box has been chosen corresponding to the volume of a small rat and illuminated by a 3G mobile phone frequency (1718.5 MHz), and the emitted radiation directed toward brain phantom .The induced fields in the phantom material are measured. Set up to lift the plane carrying the mobile phone is run by a pulley whose motion is controlled by a stepper motor. The platform is made to move at a pre-determined rate of 2 degrees per min limited up to 20 degrees. The measured data for induced fields in various locations are used to compute corresponding SAR values and inter comparison obtained. These data are also compared with those when the mobile phone is placed horizontally with respect to the position of the animal. The SAR data is also experimentally obtained by measuring a rise in temperature due to this mobile exposures and data compared with those obtained in the previous set. To seek a comparison with the safety criteria same set of measurements are performed in 10 g phantom material contained in a cubical box. These results are higher than those obtained with the knowledge of induced field measurements. It is concluded that SAR values are sensitive to the angular position of the moving platform and are well below the safety criteria prescribed for human exposure. The data are suggestive of having a fresh look to understand the mode of electromagnetic field -bio interaction.

  10. Chernobyl Experience in the Field of Retrospective Dosimetry

    International Nuclear Information System (INIS)

    Chumak, V.; Bakhanova, E.

    2011-01-01

    Chernobyl accident, which occurred on April 26, 1986 at NPP located less than 150 km north of Kiev, is the largest nuclear accident ever. Unprecedented scale of the accident was determined not only by the amount of released activity, but also by a number of population and workers involved and, therefore, exposed to enhanced doses of ionizing radiation. Population of the 30-km exclusion zone numbering about 116,000 persons of all ages and both genders was evacuated within days and weeks after the accident, emergency workers called ''liquidators of the accident'' (males age 20-50) were involved into clean-up and recovery for 5 years and their number is estimated as 600,000, about 300,000 are Ukrainian citizens. Due to unexpected and excessively large scale accident, none of residents had personal dosimeters, personal dosimetry of liquidators was not total, dosimetry techniques and practices were far from the optimum. As a result, an acute need for retrospective dose assessment was dictated by radiation protection and research considerations. This need was responded by implementation of wide scale dose reconstruction efforts, which covered main exposed cohorts and encompassed broad variety of newly developed methods: analytical (time-and-motion), modeling, biological and physical (EPR spectroscopy of teeth, TL of quartz). The presentation summarizes vast experience accumulated by RCRM in the field of retrospective dosimetry of large cohorts of exposed population and professionals. These dose reconstruction projects were implemented, in particular, in the framework of epidemiological studies, designed to follow-up medical consequences of Chernobyl accident and study health effects of ionizing radiation, in particular, Ukrainian-American studies of cataracts and leukemia among liquidators. Over 25 years passed after Chernobyl accident a broad variety of retrospective dosimetry problems was addressed by the team of Research Center for Radiation Medicine AMS Ukraine. In

  11. The effect of hydrogen absorption on the structural, electronic and magnetic properties of the C15 Friauf-Laves phase compounds CeFe2, CeRu2 and LaRu2 : an x-ray absorption spectroscopy (XAS) study

    International Nuclear Information System (INIS)

    Chaboy, J.; Garcia, J.; Marcelli, A.

    1995-08-01

    An x-ray absorption spectroscopy (XAS) investigation of the structural changes occurred upon hydriding in the Friauf-Laves phase compounds CeFe 2 , CeRu 2 and LaRu 2 compounds is presented. The analysis of the extended x-ray absorption spectroscopy (EXAFS) spectra at the L-edges of the rare-earth and at the Fe K-edge indicates that the hydrogenation process leads to the suppression of the long-range crystalline order in all the hydride derivates investigated, as well as the different influence of H 2 in both the rare earth and transition metal sublattices. The correlation between the structural and magnetic changes induced by the hydrogen in the lost matrix is discussed in terms of the modification of the electronic properties, i.e., intermediate-valence of Ce, and of the hybridization between the transition metal and rare-earth

  12. The US Department of Energy Personnel Dosimetry Evaluation and Upgrade Program

    International Nuclear Information System (INIS)

    Faust, L.G.; Stroud, C.M.; Swinth, K.L.; Vallario, E.J.

    1987-11-01

    The US Department of Energy (DOE) Personnel Dosimetry Evaluation and Upgrade Program is designed to identify and evaluate dosimetry deficiencies and to conduct innovative research and development programs that will improve overall capabilities, thus ensuring that DOE can comply with applicable standards and regulations for dose measurement. To achieve these goals, two programs were initiated to evaluate and upgrade beta measurement and neutron dosimetry. 3 refs

  13. Electronic properties and optical absorption of graphene-polyvinylidene fluoride nanocomposites: A theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, Siddheshwar, E-mail: schopra1@amity.edu

    2017-01-15

    Graphene/polyvinylidene fluoride (graphene/PVDF) nanocomposites were studied using Density functional theory (DFT)/Time dependent density functional theory (TDDFT) calculations. Five nanocomposite configurations were constructed. Electronic properties like binding energy, electronic gap and work function were calculated. The most stable structure was determined. The electronic gap of graphene shifts from semiconducting to conducting, on nanocomposite formation. Workfunction of the most stable nanocomposite was 4.34eV ± 0.05eV, close to that of the pristine graphene (4.33eV ± 0.05eV). Thermochemical analysis showed that the adsorption is spontaneous above ∼870 K, and endothermic in nature. TDDFT calculations were performed for B3LYP, LSDA, BHHLYP and PBE0 functionals. B3LYP and PBE0 are suitable in describing optical absorption. Optical gap of graphene shrinks, and light absorption gets enhanced on nanocomposite formation. - Highlights: • Various properties of graphene-PVDF nanocomposites were studied theoretically. • Electronic gap of graphene shifts to conducting nature, on composite formation. • Adsorption is spontaneous above ∼870 K, and endothermic in nature. • B3LYP and PBE0 functionals are suitable in describing absorption. • Optical absorption gets enhanced on nanocomposite formation.

  14. Electronic properties and optical absorption of graphene-polyvinylidene fluoride nanocomposites: A theoretical study

    International Nuclear Information System (INIS)

    Chopra, Siddheshwar

    2017-01-01

    Graphene/polyvinylidene fluoride (graphene/PVDF) nanocomposites were studied using Density functional theory (DFT)/Time dependent density functional theory (TDDFT) calculations. Five nanocomposite configurations were constructed. Electronic properties like binding energy, electronic gap and work function were calculated. The most stable structure was determined. The electronic gap of graphene shifts from semiconducting to conducting, on nanocomposite formation. Workfunction of the most stable nanocomposite was 4.34eV ± 0.05eV, close to that of the pristine graphene (4.33eV ± 0.05eV). Thermochemical analysis showed that the adsorption is spontaneous above ∼870 K, and endothermic in nature. TDDFT calculations were performed for B3LYP, LSDA, BHHLYP and PBE0 functionals. B3LYP and PBE0 are suitable in describing optical absorption. Optical gap of graphene shrinks, and light absorption gets enhanced on nanocomposite formation. - Highlights: • Various properties of graphene-PVDF nanocomposites were studied theoretically. • Electronic gap of graphene shifts to conducting nature, on composite formation. • Adsorption is spontaneous above ∼870 K, and endothermic in nature. • B3LYP and PBE0 functionals are suitable in describing absorption. • Optical absorption gets enhanced on nanocomposite formation.

  15. Measurement of the internal organs' absorption and extracorporeal excretion of radioactive iodine fit to the characteristics of Koreans

    International Nuclear Information System (INIS)

    Kim, Jung Hoon; Kim, Tae Man; Whang, Joo Ho

    2005-01-01

    Radiation dosimetry will prove helpful to active approaches, such as limiting the amount of radiation exposure, which can be called the negative effect of radiation on the body, or using radiation to treat diseases. Defective nuclear fuel at a nuclear power plant or 131 I used for oral thyroid gland examination and treatment of cancer may cause internal exposure during the replacement of nuclear fuel, or maintenance. Also, it is reported that, clinically, 131 I has the negative function of increasing the radiation exposure of the other organs as well as the positive function related to thyroid gland diagnosis and cancer treatment. Estimation of internal exposure to 131 I must take the physical properties of 131 I and the physiological properties of individuals into account. The extracorporeal excretion rate of radionuclides and the proportion remaining in the body may vary depending on the physiological properties of the Oriental and Occidental people. The existing physiological properties are data originating from Westerners, so if the data are applied to Koreans, differences in dietary life and physiological properties may lead to underestimation or overestimation of internal exposure. Therefore, this study aims at measuring the radionuclide absorption and excretion rates in human organs to establish the physiological radionuclide metabolism fit to Koreans and the Oriental people whose physique is similar to that of Koreans

  16. Cellulose/inorganic-composite fibers for producing textile fabrics of high X-ray absorption properties

    International Nuclear Information System (INIS)

    Günther, Karoline; Giebing, Christina; Askani, Antonia; Leisegang, Tilmann; Krieg, Marcus; Kyosev, Yordan; Weide, Thomas; Mahltig, Boris

    2015-01-01

    Common textile materials as cotton or polyester do not possess reliable X-ray absorption properties. This is due to their morphology and chemical composition in particular. Common fibers are built up from organic polymers containing mainly the elements carbon, hydrogen, oxygen and nitrogen. These “light” elements only have low X-ray absorption coefficients. In contrast, inorganic materials composed of “heavy” elements with high atomic numbers, e.g. barium or bismuth, exhibit X-ray absorption coefficients higher by up to two orders of magnitude. To obtain a flexible yarn with high X-ray absorption properties both these materials, the organic polymer and the inorganic X-ray absorber, are combined to an inorganic/organic composite fiber material. Hence, as the organic component cellulose from modified Lyocell-process is used as carrier fiber and blended with inorganic absorber particles of low toxicity and high absorption coefficients, as bariumsulphate, bariumtitanate or bismuthoxide. A content of inorganic absorber particles equally distributed in the whole fiber of up to 20% is achieved. The composite fibers are produced as staple or filament fibers and processed to multifilament or staple fiber yarns. The staple fiber yarns are rotor-spinned to increase the comfort of the subsequent textile material. Several woven fabrics, considering multilayer structure and different warp/weft density, are developed. The energy dependent X-ray shielding properties are determined in dependence on the different yarn compositions, yarn types and structural parameters of the woven fabrics. As a result, a production process of textile materials with comfortable and dedicated X-ray absorption properties is established. It offers a promising opportunity for manufacturing of specialized textiles, working clothes or uniforms applicable for medicine, air craft and security personal, mining as well as for innovative composite materials. - Highlights: • Preparation of cellulosic

  17. Cellulose/inorganic-composite fibers for producing textile fabrics of high X-ray absorption properties

    Energy Technology Data Exchange (ETDEWEB)

    Günther, Karoline; Giebing, Christina; Askani, Antonia [FTB, Hochschule Niederrhein – University of Applied Science, Faculty of Textile and Clothing Technology, Webschulstr. 31, 41065 Mönchengladbach (Germany); Leisegang, Tilmann [Saxray GmbH, Maria-Reiche-Str. 1, 01109 Dresden (Germany); Krieg, Marcus [TITK, Thüringisches Institut für Textil- und Kunststoff-Forschung e.V., Breitscheidstraße 97, 07407 Rudolstadt (Germany); Kyosev, Yordan; Weide, Thomas [FTB, Hochschule Niederrhein – University of Applied Science, Faculty of Textile and Clothing Technology, Webschulstr. 31, 41065 Mönchengladbach (Germany); Mahltig, Boris, E-mail: Boris.Mahltig@hs-niederrhein.de [FTB, Hochschule Niederrhein – University of Applied Science, Faculty of Textile and Clothing Technology, Webschulstr. 31, 41065 Mönchengladbach (Germany)

    2015-11-01

    Common textile materials as cotton or polyester do not possess reliable X-ray absorption properties. This is due to their morphology and chemical composition in particular. Common fibers are built up from organic polymers containing mainly the elements carbon, hydrogen, oxygen and nitrogen. These “light” elements only have low X-ray absorption coefficients. In contrast, inorganic materials composed of “heavy” elements with high atomic numbers, e.g. barium or bismuth, exhibit X-ray absorption coefficients higher by up to two orders of magnitude. To obtain a flexible yarn with high X-ray absorption properties both these materials, the organic polymer and the inorganic X-ray absorber, are combined to an inorganic/organic composite fiber material. Hence, as the organic component cellulose from modified Lyocell-process is used as carrier fiber and blended with inorganic absorber particles of low toxicity and high absorption coefficients, as bariumsulphate, bariumtitanate or bismuthoxide. A content of inorganic absorber particles equally distributed in the whole fiber of up to 20% is achieved. The composite fibers are produced as staple or filament fibers and processed to multifilament or staple fiber yarns. The staple fiber yarns are rotor-spinned to increase the comfort of the subsequent textile material. Several woven fabrics, considering multilayer structure and different warp/weft density, are developed. The energy dependent X-ray shielding properties are determined in dependence on the different yarn compositions, yarn types and structural parameters of the woven fabrics. As a result, a production process of textile materials with comfortable and dedicated X-ray absorption properties is established. It offers a promising opportunity for manufacturing of specialized textiles, working clothes or uniforms applicable for medicine, air craft and security personal, mining as well as for innovative composite materials. - Highlights: • Preparation of cellulosic

  18. Radiotherapy gel dosimetry

    International Nuclear Information System (INIS)

    Baldock, C.

    2002-01-01

    be either through direct absorption of ionising radiation or via intermediate water free radicals. Fe 2+ ions are converted to Fe 3+ ions with a corresponding change in paramagnetic properties that may be quantified using NMR relaxation measurements or optical techniques. Due to predominantly diffusion-related limitations (and references therein), alternative polymer gel dosimeters were subsequently suggested. In polymer gels, monomers such as acrylamide and N,N'-methylene-bis-acrylamide are usually dispersed in a gelatin or agarose matrix. Monomers undergo a polymerisation reaction as a function of absorbed dose resulting in a 3D polymer gel matrix. The radiation-induced formation of polymer influences NMR relaxation properties and results in other physical changes that may be used to quantify absorbed radiation dose. As well as MRI, other quantitative techniques for measuring dose distributions include X-ray computer tomography, vibrational spectroscopy and ultrasound. Clinical applications of these radiologically tissue equivalent gel dosimeters have been reported in the literature. For further information of gel dosimetry and specifically clinical applications the proceedings of the 2nd International Conference on Radiotherapy Gel Dosimetry and references therein should be consulted

  19. Situation and development of solid state dosimetry from the PTB-point of view

    International Nuclear Information System (INIS)

    Hahn, D.; Nink, R.

    An outline is given of the legal situation concerning dosimetry in the field of radiation protection in the Federal Republic of Germany which is ruled by the German law of verification. The Physikalisch-Technische Bundesanstalt (PTB) therefore has worked out requirements for the type approval of TLD systems the main points of which are discussed briefly. A further progress of TLD - measuring methods and materials - seems desirable. Therefore, extended research with regard to preparation, TL mechanism and dosimetric properties is necessary. Examples of the activities in the solid state physics group of PTB - mainly concerning TLD an LiF - are given

  20. The sensitivity analysis of tooth enamel to the absorbed dose for the application to EPR dosimetry

    International Nuclear Information System (INIS)

    Hong, Dae Seok; Lee, Kun Jai; Cho, Young Hwan

    2002-01-01

    Electron Paramagnetic Resonance (EPR) spectroscopy is one of the methods applicable to retrospective dosimetry. The retrospective dosimetry is a process that is a part of dose reconstruction for estimation of exposed dose occurred years before the estimation. Many techniques can be used to the retrospective dosimetry. As a physical method, EPR analysis of biological material measures the quantity of free radicals generated in the material from the interaction of radiation and material. Since the later 80s, in many countries, EPR dosimetry with tooth enamel has been studied and applied for the retrospective dosimetry. In the consideration of the biological materials for EPR dosimetry, human fingernail, hair, bone and tooth are generally considered. The tooth can be separated as enamel, dentine and cementum. Among the three parts, enamel shows the best sensitivity to the absorbed dose and is most widely used. In this study, the characteristics of tooth enamel for EPR dosimetry is examined and experimented. At the experiment, for easy separation, tooth was cut into 4 parts and then each part is treated by ultrasonic vibration in NaOH liquid to reduce mechanically induced noise in the corresponding signal. After the separation of the enamel from dentine, background EPR signal is measured and then radiation-induced EPR spectrum is estimated

  1. The PADE dosimetry system at the Brokdorf nuclear power station

    International Nuclear Information System (INIS)

    Poetter, Karl-Friedrich; Eckelmann, Joerg; Kuegow, Mario; Spahn, Werner; Franz, Manfred

    2002-01-01

    The PADE program system is used in nuclear power plants for personnel and workplace dosimetry and for managing access to the controlled area. On-line interfaces with existing dose determination systems allow collection, surveillance and evaluation functions to be achieved for person-related and workplace-related dose data. This is managed by means of open, non-proprietary communication of PADE with the computer system coupled via interfaces. In systems communication, PADE is limited to main interventions into outside systems, thus ensuring flexible adaptation to existing systems. As a client-server solution, PADE has been developed on the basis of an ORACLE-8 database; the version presented here runs on a Windows NT server. The system described has been used at the Brokdorf Nuclear Power Station since early 2000 and has so far reliably managed more than one million individual access movements of more than 6 000 persons. It is currently being integrated into a comprehensive plant operations management system. Among other things, PADE offers a considerable development potential for a tentatively planned future standardization of parts of the dosimetry systems in German nuclear power plants and for the joint management of in-plant and official dose data. (orig.) [de

  2. DFT/TD-semiempirical study on the structural and electronic properties and absorption spectra of supramolecular fullerene-porphyrine-metalloporphyrine triads based dye-sensitized solar cells

    Science.gov (United States)

    Rezvani, M.; Darvish Ganji, M.; Jameh-Bozorghi, S.; Niazi, A.

    2018-04-01

    In the present work density functional theory (DFT) and time-dependent semiempirical ZNIDO/S (TD-ZNIDO/S) methods have been used to investigate the ground state geometries, electronic structures and excited state properties of triad systems. The influences of the type of metal in the porphyrin ring, change in bridge position and porphyrine-ZnP duplicate on the energies of frontier molecular orbital and UV-Vis spectra has been studied. Geometry optimization, the energy levels and electron density of the Highest Occupied Molecular Orbital (HOMO) and the Lowest Unoccupied Molecular Orbital (LUMO), chemical hardness (η), electrophilicity index (ω), electron accepting power (ω+) were calculated using ZINDO/S method to predict which molecule is the most efficient with a great capability to be used as a triad molecule in solar industry. Moreover the light harvesting efficiency (LHE) was calculated by means of the oscillator strengths which are obtained by TD-ZINDO/S calculation. Theoretical studies of the electronic spectra by ZINDO/S method were helpful in interpreting the observed electronic transitions. This aspect was systematically explored in a series of C60-Porphyrine-Metalloporphyrine (C60-P-Mp) triad system with M being Fe, Co, Ni, Ti, and Zn. Generally, transition metal coordination compounds are used as effective sensitizers, due to their intense charge-transfer absorption over the whole visible range and highly efficient metal-to-ligand charge transfer. We aim to optimize the performance of the title solar cells by altering the frontier orbital energy gaps. The results reveal that cell efficiency can be enhanced by metal functionalization of the free base porphyrin. Ti-porphyrin was found to be the most efficient dye sensitizer for dye sensitized solar cells (DSSCs) based on C60-P-Mptriad system due to C60-Por-TiP complex has lower chemical hardness, gap energy and chemical potential as well as higher electron accepting power among other complexes. In

  3. Dielectric and microwave absorption properties of TiO_2/Al_2O_3 coatings and improved microwave absorption by FSS incorporation

    International Nuclear Information System (INIS)

    Yang, Zhaoning; Luo, Fa; Hu, Yang; Duan, Shichang; Zhu, Dongmei; Zhou, Wancheng

    2016-01-01

    In this paper, TiO_2/Al_2O_3 ceramic coatings were prepared by atmospheric plasma spraying (APS) technique. The phase composition and morphological characterizations of the synthesized TiO_2/Al_2O_3 powders and coatings were performed by X-ray diffraction and scanning electron microscopy (SEM), respectively. The dielectric properties of these coatings were discussed in the frequency range from 8.2 to 12.4 GHz (X-band). By calculating the microwave-absorption as a single-layer absorber, their microwave absorption properties were investigated at different content and thickness in details. Furthermore, by combination of the Frequency selective surface (FSS) and ceramic coatings, a double absorption band of the reflection loss spectra had been observed. The microwave absorbing properties of coatings both in absorbing intensity and absorbing bandwidth were improved. The reflection loss values of TiO_2/Al_2O_3 coatings exceeding −10 dB (larger than 90% absorption) can be obtained in the whole frequency range of X-band with 17 wt% TiO_2 content when the coating thickness is 2.3 mm. - Highlights: • Dielectric properties of TiO_2/Al_2O_3 ceramics fabricated by APS technique are reported for the first time. • Microwave absorption properties of TiO_2/Al_2O_3 composites are improved by FSS. • Reflection loss values exceeding −10 dB can be obtained in the whole X-band when coating thickness is 2.3 mm.

  4. Environmental dosimetry

    International Nuclear Information System (INIS)

    Gold, R.

    1977-01-01

    For more than 60 years, natural radiation has offered broad opportunities for basic research as evidenced by many fundamental discoveries. Within the last decade, however, dramatic changes have occurred in the motivation and direction of this research. The urgent need for economical energy sources entailing acceptably low levels of environmental impact has compelled the applied aspects of our radiation environment to become overriding considerations. It is within this general framework that state-of-the-art environmental dosimetry techniques are reviewed. Although applied motivation and relevance underscores the current milieu for both reactor and environmental dosimetry, a perhaps even more unifying force is the broad similarity of reactor and environmental radiation fields. In this review, a comparison of these two mixed radiation fields is presented stressing the underlying similarities that exist. On this basis, the evolution of a strong inner bond between dosimetry methods for both reactor and environmental radiation fields is described. The existence of this bond will be illustrated using representative examples of observed spectra. Dosimetry methods of particularly high applicability for both of these fields are described. Special emphasis is placed on techniques of high sensitivity and absolute accuracy which are capable of resolving the components of these mixed radiation fields

  5. Dosimetry in air in the product 1 gamma irradiator

    International Nuclear Information System (INIS)

    Espinosa Echavarria, R.

    1990-01-01

    In this paper are presented the results of the dosimetry in air in the product-1 gamma irradiator of the Research Institute of the Food Industry. The dose was measured with the Fricke system. This dosemeter was used for the determination of the dose distribution in the irradiator container. It was obtained the minimum, maximum and overall average value of the dose. The calibration functions of the plant well time, evaluated using linear regression analysis, present very good adjustment for these parameters when it was chosen four different settings for the well time. The dose uniformity ratio is 1.3. 11 refs

  6. Fundamentals of Dosimetry. Chapter 3

    Energy Technology Data Exchange (ETDEWEB)

    Yoshimura, E. M. [Universidade de São Paulo, São Paulo (Brazil)

    2014-09-15

    Determination of the energy imparted to matter by radiation is the subject of dosimetry. The energy deposited as radiation interacts with atoms of the material, as seen in the previous chapter. The imparted energy is responsible for the effects that radiation causes in matter, for instance, a rise in temperature, or chemical or physical changes in the material properties. Several of the changes produced in matter by radiation are proportional to the absorbed dose, giving rise to the possibility of using the material as the sensitive part of a dosimeter. Also, the biological effects of radiation depend on the absorbed dose. A set of quantities related to the radiation field is also defined within the scope of dosimetry. It will be shown in this chapter that, under special conditions, there are simple relations between dosimetric and field description quantities. Thus, the framework of dosimetry is the set of physical and operational quantities that are studied in this chapter.

  7. Modification of fish skin collagen film and absorption property of tannic acid.

    Science.gov (United States)

    Liu, Haiying; Zhao, Lu; Guo, Shidong; Xia, Yu; Zhou, Peng

    2014-06-01

    Fish collagen is a biomacromolecule material and is usually used as a clarifying agent. However, fish collagen is not recyclable, and sedimentation usually occurs in the clarification process using fish collagen so that the filtration process is inevitable. This work aimed to provide a recyclable modified fish skin collagen film (MFCF) for adsorption of tannic acids. The collagen from channel catfish skin was extracted and used for preparation of the fish skin collagen film (FCF) and MFCF. The result indicated that the mechanical properties of MFCF were improved by addition of 2 ml/L glycerol, 6 ml/L polyvinyl alcohol (PVA) and 2 ml/L glutaraldehyde in 15 g/L collagen solution. As the most important property of adsorption material, the hydroscopicity of MFCF was only 54%, significantly lower than that of FCF (295%). Therefore, MFCF would not collapse in water. The infrared and thermal properties of MFCF were also investigated in this work. Results indicated that, in comparison to FCF, the physical and chemical properties of MFCF had been improved significantly. MFCF had higher shrink temperature (79.3 °C) and it did not collapse in distilled water at normal temperature. Furthermore, absorption and desorption properties of tannic acid were studied. MFCF showed good capability of absorption and desorption of tannic acid, which leaded to the suggestion that MFCF could have potential applications in adsorption material.

  8. Investigation of the Spatial Resolution of MR-Based Polymer Gel Dosimetry versus Film Densitometry using Dose Modulation Transfer Function

    Directory of Open Access Journals (Sweden)

    Reza Moghadam-Drodkhani

    2011-03-01

    Full Text Available Introduction: The conventional methods of dosimetry are not capable of dosimetry in such a small volume of less than one cubic millimeter. Although the polymer gel dosimetry method based on magnetic resonance imaging (MRI could achieve three dimensional dosimetry with high resolution, a spatial resolution evaluation based on gel dose modulation transfer function has not been investigated yet. Therefore, in this study, the spatial resolution of two systems of film densitometry and polymer gel dosimetry based on MRI has been evaluated by using the dose modulation transfer function (DMTF.   Material and Methods: Kodak therapy verification films and MAGICA polymer gel samples were positioned below a brass absorption grid with different periodic slices (a/2= 280, 525, 1125 μm, which was placed in a water bath container to avoid regions of dose build-up just below the absorption grid and then irradiated with Cobalt-60 photons on a Theratron external-beam treatment unit. Dose variation under the brass grid was determined using a calibration curve, while transverse relaxation time (T2 as the selective parameter in a dose image based on multiple echo MRI with 1.5 Tesla GE Signa Echo Speed system (FOV=10 cm, matrix size=512 ×512, pixel size =0.199×0.199 mm2, TE = 20, 40, 60, 80 ms, TR=4200 ms, NEX = 4, slice thickness=2 mm, gap=1 mm was calculated. DMTF from the modulation depths of T2 and variation in film optical density after calibration would be achieved. The results of polymer gel were compared with film. Results: After deriving the dose distribution profile under the absorption grid, minima and maxima at the smallest period of a = 560 μm could scarcely be resolved, but the modulations due to a=2250 μm and a = 1050 μm grids could be discerned. The modulation depth for a=2250 μm grid was set to 100% and the other modulations were subsequently referred to this maximum modulation. For film densitometry at a = 1050 μm, the modulation depth was

  9. Answer to request on the ININ internal dosimetry

    International Nuclear Information System (INIS)

    Alfaro L, M.M.

    1999-05-01

    In this report it is presented the reply to CNSNS asking for information about the methodology for the evaluation of the occupational dose due to internal contamination. The characteristics of the installation, type and dimensions of the shield room, construction materials, type of detecting, calibration geometries, type of used phantom, intervals of energy of the calibration, type of routine measurements, detection limit for Cs-137 and Co-60, code to carry out the analysis of the spectra, evaluation of the measurement data, whole body system type armchair with anthropomorphic phantom, whole body system of vertical scanning, distribution and location diagram of the internal dosimetry laboratory there are among the treated aspects. (Author

  10. Commissioning dosimetry for the laboratory irradiation facility type PX-γ-30

    International Nuclear Information System (INIS)

    Prieto Miranda, E.F.; Cuesta Fuente, G.I.; Chavez Ardanza, A.; Sainz Vidal, D.

    1997-01-01

    In the present paper at the laboratory irradiation type PX-y-30 was carried out the commissioning dosimetry, which belongs to Radiological Department of the CEADEN. It was determined the dose distribution as well as principal dosimetric parameters of the irradiation process. Besides, an irradiation position was found for the calibration or intercomparison of dosimetry systems

  11. TLD personnel dosimetry and its relationship with the radiodiagnostic training

    International Nuclear Information System (INIS)

    Gaona, E.; Franco E, J.G.; Gaona C, E.

    2002-01-01

    The personnel dosimetry and the training in radiological protection in radiodiagnostic in Mexico before 1997 were almost nonexistent except few services of public and private radiology, we can to say that the personnel dosimetry and the obligatory training was born in the year 1997, together with the present Mexican Official Standards in radiology. This study has the purpose to make an evaluation of the personnel dosimetry of 110 radiology services distributed in the Mexican Republic for the year 2001 and to estimate the annual and bimonthly mean doses, as well as its trust intervals and its relationships with the personnel training in radiological protection by means of a sampling that was realized in two stages (1997 and 2000) in the metropolitan area of Mexico City. The results show that the received doses by the medical and technical personnel in the participating radiology services are in the 0.03 mSv and 0.94 mSv interval and the mean is 0.25 mSv. The estimated annual personnel dose would be in the 0.18 mSv to 5.64 mSv interval, which are values very lower to the annual dose limit that is 50 mSv and its magnitude is similar to the effective annual dose by natural background radiation. In the first stage in training was found that there is not a significant difference in the response frequencies among the medical and technical personnel with a p < 0.05. The 52% of the occupational exposure personnel of radiology uses dosemeter, but only 17% of them know the dose reports. the 15.8% of personnel considers that dosemeter protects against radiation and only 16.5% knows the annual maximum permissible dose for stochastic effects. The second stage, the results shown that there is a significant difference in the response of frequencies among medical and technical personnel, the same results which are obtained for members and non members of a professional association with a p < 0.05. The 38% has personnel dosimetry, the 19% knows the principles of radiological

  12. Determination of the components of uncertainty for a dosimetry system in radiation protection

    International Nuclear Information System (INIS)

    Lopez, F.; Cabral, T.S.; Peixoto, J.G.

    2013-01-01

    This work is about the theoretical calculation of uncertainties associated to the dosimetry of photons of a 137 Cs source that will be used in a Dosimetry Laboratory. In this case recognition of the influence quantities that provide most uncertainty and the right choice of resolution of auxiliary equipment to obtain the smallest uncertainties according to the laboratory. (author)

  13. The effect of Se/Te ratio on transient absorption behavior and nonlinear absorption properties of CuIn0.7Ga0.3(Se1-xTex)2 (0 ≤ x ≤ 1) amorphous semiconductor thin films

    Science.gov (United States)

    Karatay, Ahmet; Küçüköz, Betül; Çankaya, Güven; Ates, Aytunc; Elmali, Ayhan

    2017-11-01

    The characterization of the CuInSe2 (CIS), CuInGaSe (CIGS) and CuGaSe2 (CGS) based semiconductor thin films are very important role for solar cell and various nonlinear optical applications. In this paper, the amorphous CuIn0.7Ga0.3(Se1-xTex)2 semiconductor thin films (0 ≤ x ≤ 1) were prepared with 60 nm thicknesses by using vacuum evaporation technique. The nonlinear absorption properties and ultrafast transient characteristics were investigated by using open aperture Z-scan and ultrafast pump-probe techniques. The energy bandgap values were calculated by using linear absorption spectra. The bandgap values are found to be varying from 0.67 eV to 1.25 eV for CuIn0.7Ga0.3Te2, CuIn0.7Ga0.3Se1.6Te0.4, CuIn0.7Ga0.3Se0.4Te1.6 and CuIn0.7Ga0.3Se2 thin films. The energy bandgap values decrease with increasing telluride (Te) doping ratio in mixed CuIn0.7Ga0.3(Se1-xTex)2 films. This affects nonlinear characteristics and ultrafast dynamics of amorphous thin films. Ultrafast pump-probe experiments indicated that decreasing of bandgap values with increasing the Te amount switches from the excited state absorption signals to ultrafast bleaching signals. Open aperture Z-scan experiments show that nonlinear absorption properties enhance with decreasing bandgaps values for 65 ps pulse duration at 1064 nm. Highest nonlinear absorption coefficient was found for CuIn0.7Ga0.3Te2 thin film due to having the smallest energy bandgap.

  14. Dosimetry Measurements around the Angiography Units Using Thermoluminescence Detectors (TLD)

    International Nuclear Information System (INIS)

    Salah El-den, T.; Shahein, A.Y.; Gomaa, M.A.

    2008-01-01

    The thermoluminescent dosimeters (TLDs) are widely used not only in the field of personnel monitoring (dosimetry) service for ionizing radiation to medical, and research communities, but also for measurements of X-rays emitted from different angiography's unit. Measurements ionizing radiation around the bed area during cardiac catheterization procedures using X-rays was measured. TLD Badges used to determine the annual effective doses, the safe distance for the staff to minimize radiation exposure and the effectiveness of shield and used leaded apron. The results indicated that annual effective dose for by angiography cardiac Catheterization room may exceed the limits

  15. Report on the Personnel Dosimetry at AB Atomenergi during 1962

    Energy Technology Data Exchange (ETDEWEB)

    Edvardsson, K A; Hagsgaard, S

    1964-07-15

    This report presents the results of the personnel dosimetry at AB Atomenergi during 1963. No doses exceeding the recommendations of ICRP have been reported. The sum of the reported external total body doses during the year is for AB Atomenergi 64.2 manrem which, distributed over the whole company personnel, corresponds to about 40 mrem per year and person or about 1 % of the maximum permissible dose. 37800 gamma films and 6700 neutron films have been evaluated. The total number of urine analyses is 3603 and of whole body measurements 211.

  16. High energy neutron dosimetry for the fusion program

    International Nuclear Information System (INIS)

    Barr, D.W.; Norris, A.E.

    1977-01-01

    Neutron dosimetry by the foil activation method offers a flexible technique for characterizing neutron spectra ranging from thermal energies to 30 MeV with the potential for extension to higher neutron energies as investigated by the Los Alamos Radiochemistry Group at the Los Alamos Meson Physics Facility and in the Apollo-Soyuz Test Project. The use of this method for the neutron flux description in thermal, resonance, and fission spectrum assemblies has been demonstrated. An extension of the method to environments involving thermonuclear processes was developed at Los Alamos in the early 1950's to characterize mixed fission-thermonuclear systems

  17. Nanofluid optical property characterization: towards efficient direct absorption solar collectors.

    Science.gov (United States)

    Taylor, Robert A; Phelan, Patrick E; Otanicar, Todd P; Adrian, Ronald; Prasher, Ravi

    2011-03-15

    Suspensions of nanoparticles (i.e., particles with diameters solar thermal collectors. To determine the effectiveness of nanofluids in solar applications, their ability to convert light energy to thermal energy must be known. That is, their absorption of the solar spectrum must be established. Accordingly, this study compares model predictions to spectroscopic measurements of extinction coefficients over wavelengths that are important for solar energy (0.25 to 2.5 μm). A simple addition of the base fluid and nanoparticle extinction coefficients is applied as an approximation of the effective nanofluid extinction coefficient. Comparisons with measured extinction coefficients reveal that the approximation works well with water-based nanofluids containing graphite nanoparticles but less well with metallic nanoparticles and/or oil-based fluids. For the materials used in this study, over 95% of incoming sunlight can be absorbed (in a nanofluid thickness ≥10 cm) with extremely low nanoparticle volume fractions - less than 1 × 10-5, or 10 parts per million. Thus, nanofluids could be used to absorb sunlight with a negligible amount of viscosity and/or density (read: pumping power) increase.

  18. Report on the Personnel Dosimetry at AB Atomenergi during 1962

    International Nuclear Information System (INIS)

    Edvardsson, K.A.; Hagsgaard, S.

    1963-12-01

    This report presents the results of the personnel dosimetry at AB Atomenergi during 1962. No doses exceeding the recommendations of ICRP have been reported. The sum of the reported external total body doses (≥ 100 mrem/quarter) is for the whole of AB Atomenergi during this year 74. 2 manrem corresponding to about 50 mrem/year and person or 1 % of the maximum permissible dose. 32500 gamma films and 6200 neutron films have been evaluated. The total number of urine analyses is 2700 and of whole body measurements 10

  19. Report on the Personnel Dosimetry at AB Atomenergi during 1962

    Energy Technology Data Exchange (ETDEWEB)

    Edvardsson, K A; Hagsgaard, S

    1963-12-15

    This report presents the results of the personnel dosimetry at AB Atomenergi during 1962. No doses exceeding the recommendations of ICRP have been reported. The sum of the reported external total body doses ({>=} 100 mrem/quarter) is for the whole of AB Atomenergi during this year 74. 2 manrem corresponding to about 50 mrem/year and person or 1 % of the maximum permissible dose. 32500 gamma films and 6200 neutron films have been evaluated. The total number of urine analyses is 2700 and of whole body measurements 10.

  20. In vivo thermoluminescent dosimetry on the radiotherapy of limphomas, esophageal and uterine tumour

    International Nuclear Information System (INIS)

    Morales, F.C.

    1982-01-01

    A comparative study between dose distribution in pre-selected tumoral plans was established through measurements with thermoluminescent dosimeters and calculations based on 'scatter-air-ratios' properties, isodose curves and collected data. Clinic dosimetry was performed 'in vivo' with LiF dosimeters (TLD-100) and LiF Teflon (1 mm theta, 6 mm lenght). Patients with Hodgkin's disease, carcinoma of the esophagus and of the uterine cervix were selected. Telecobaltherapy was used for these groups of neoplasic conditions. (M.A.C.) [pt

  1. Moisture absorption and retention properties, and activity in alleviating skin photodamage of collagen polypeptide from marine fish skin.

    Science.gov (United States)

    Hou, Hu; Li, Bafang; Zhang, Zhaohui; Xue, Changhu; Yu, Guangli; Wang, Jingfeng; Bao, Yuming; Bu, Lin; Sun, Jiang; Peng, Zhe; Su, Shiwei

    2012-12-01

    Collagen polypeptides were prepared from cod skin. Moisture absorption and retention properties of collagen polypeptides were determined at different relative humidities. In addition, the protective effects of collagen polypeptide against UV-induced damage to mouse skin were evaluated. Collagen polypeptides had good moisture absorption and retention properties and could alleviate the damage induced by UV radiation. The action mechanisms of collagen polypeptide mainly involved enhancing immunity, reducing the loss of moisture and lipid, promoting anti-oxidative properties, inhibiting the increase of glycosaminoglycans, repairing the endogenous collagen and elastin protein fibres, and maintaining the ratio of type III to type I collagen. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Quality management system in the CIEMAT Radiation Dosimetry Service.

    Science.gov (United States)

    Martín, R; Navarro, T; Romero, A M; López, M A

    2011-03-01

    This paper describes the activities realised by the CIEMAT Radiation Dosimetry Service (SDR) for the implementation of a quality management system (QMS) in order to achieve compliance with the requirements of ISO/IEC 17025 and to apply for the accreditation for testing measurements of radiation dose. SDR has decided the accreditation of the service as a whole and not for each of its component laboratories. This makes it necessary to design a QMS common to all, thus ensuring alignment and compliance with standard requirements, and simplifying routine works as possible.

  3. Acute ingestion dosimetry using the ICRP 30 gastrointestinal tract model

    International Nuclear Information System (INIS)

    Cassels, B.M.

    1987-01-01

    This paper examines the gastrointestinal (GI) tract model used for dosimetry as outlined in ICRP30, to allow quick calculations of effective dose equivalents for acute radionuclide ingestion. A computer program has been developed to emulate the GI tract model. The program and associated data files are structured so that the GI tract model parameters can be varied, while the file structure and algorithm for the GI tract model should require minimal modification to allow the same theories that apply in this model to be used for other dosimetric models

  4. Radiation protection dosimetry in medicine - Report of the working group n.9 of the European radiation dosimetry group (EURADOS) - coordinated network for radiation dosimetry (CONRAD - contract EC N) fp6-12684

    International Nuclear Information System (INIS)

    2009-01-01

    This report present the results achieved within the frame of the work the WP 7 (Radiation Protection Dosimetry of Medical Staff) of the coordination action CONRAD (Coordinated Network for Radiation Dosimetry) funded through the 6. EU Framework Program. This action was coordinated by EURADOS (European Radiation Dosimetry Group). EURADOS is an organization founded in 1981 to advance the scientific understanding and the technical development of the dosimetry of ionising radiation in the fields of radiation protection, radiobiology, radiation therapy and medical diagnosis by promoting collaboration between European laboratories. WP7 coordinates and promotes European research for the assessment of occupational exposures to staff in therapeutic and diagnostic radiology workplaces. Research is coordinated through sub-groups covering three specific areas: 1. Extremity dosimetry in nuclear medicine and interventional radiology: this sub-group coordinates investigations in the specific fields of the hospitals and studies of doses to different parts of the hands, arms, legs and feet; 2. Practice of double dosimetry: this sub-group reviews and evaluates the different methods and algorithms for the use of dosemeters placed above and below lead aprons in large exposure during interventional radiology procedures, especially to determine effective doses to cardiologists during cardiac catheterization; and 3. Use of electronic personal dosemeters in interventional radiology: this sub-group coordinates investigations in laboratories and hospitals, and intercomparisons with passive dosemeters with the aim to enable the formulation of standards. (authors)

  5. Dosimetry in dentistry.

    Science.gov (United States)

    Asha, M L; Chatterjee, Ingita; Patil, Preeti; Naveen, S

    2015-01-01

    The purpose of this paper was to review various dosimeters used in dentistry and the cumulative results of various studies done with various dosimeters. Several relevant PubMed indexed articles from 1999 to 2013 were electronically searched by typing "dosimeters", "dosimeters in dentistry", "properties of dosimeters", "thermoluminescent and optically stimulated dosimeters", "recent advancements in dosimetry in dentistry." The searches were limited to articles in English to prepare a concise review on dental dosimetry. Titles and abstracts were screened, and articles that fulfilled the criteria of use of dosimeters in dental applications were selected for a full-text reading. Article was divided into four groups: (1) Biological effects of radiation, (2) properties of dosimeters, (3) types of dosimeters and (4) results of various studies using different dosimeters. The present review on dosimetry based on various studies done with dosimeters revealed that, with the advent of radiographic technique the effective dose delivered is low. Therefore, selection of radiological technique plays an important role in dental dose delivery.

  6. EURADOS. A success story for European cooperation in the dosimetry of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Ruehm, Werner [Helmholtz Zentrum Muenchen, Neuherberg (Germany). German Research Center for Environmental Health (GMBH); Schuhmacher, Helmut [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany)

    2017-10-01

    EURADOS (European Radiation Dosimetry Group) is a European research platform aiming at the promotion of research and development and European cooperation in the field of the dosimetry of ionizing radiation (www.eurados.org). Initially founded in 1982, it was established in 2008 as a non-profit registered society under German law and is currently based in Neuherberg, Germany.

  7. Dosimetry for Electron Beam Applications

    DEFF Research Database (Denmark)

    Miller, Arne

    1983-01-01

    This report describes two aspects of electron bean dosimetry, on one hand developaent of thin fil« dosimeters and measurements of their properties, and on the other hand developaent of calorimeters for calibration of routine dosimeters, e.g. thin films. Two types of radiochromic thin film...

  8. Experimental investigation on photothermal properties of nanofluids for direct absorption solar thermal energy systems

    International Nuclear Information System (INIS)

    He, Qinbo; Wang, Shuangfeng; Zeng, Shequan; Zheng, Zhaozhi

    2013-01-01

    Highlights: • The factors affecting the transmittance of Cu–H 2 O nanofluids were studied with UV–Vis–NIR spectrophotometer. • The optical properties of Cu–H 2 O nanofluids were studied through the theoretical model. • The Cu–H 2 O nanofluids can enhance the absorption ability for solar energy. - Abstract: In this article, Cu–H 2 O nanofluids were prepared through two-step method. The transmittance of nanofluids over solar spectrum (250–2500 nm) was measured by the UV–Vis–NIR spectrophotometer based on integrating sphere principle. The factors influencing transmittance of nanofluids, such as particle size, mass fraction and optical path were investigated. The extinction coefficients measured experimentally were compared with the theoretical calculation value. Meanwhile, the photothermal properties of nanofluids were also investigated. The experimental results show that the transmittance of Cu–H 2 O nanofluids is much less than that of deionized water, and decreases with increasing nanoparticle size, mass fraction and optical depth. The highest temperature of Cu–H 2 O nanofluids (0.1 wt.%) can increased up to 25.3% compared with deionized water. The good absorption ability of Cu–H 2 O nanofluids for solar energy indicates that it is suitable for direct absorption solar thermal energy systems

  9. Polyethylene Naphthalate Scintillator: A Novel Detector for the Dosimetry of Radioactive Ophthalmic Applicators.

    Science.gov (United States)

    Flühs, Dirk; Flühs, Andrea; Ebenau, Melanie; Eichmann, Marion

    2015-09-01

    Dosimetric measurements in small radiation fields with large gradients, such as eye plaque dosimetry with β or low-energy photon emitters, require dosimetrically almost water-equivalent detectors with volumes of <1 mm(3) and linear responses over several orders of magnitude. Polyvinyltoluene-based scintillators fulfil these conditions. Hence, they are a standard for such applications. However, they show disadvantages with regard to certain material properties and their dosimetric behaviour towards low-energy photons. Polyethylene naphthalate, recently recognized as a scintillator, offers chemical, physical and basic dosimetric properties superior to polyvinyltoluene. Its general applicability as a clinical dosimeter, however, has not been shown yet. To prove this applicability, extensive measurements at several clinical photon and electron radiation sources, ranging from ophthalmic plaques to a linear accelerator, were performed. For all radiation qualities under investigation, covering a wide range of dose rates, a linearity of the detector response to the dose was shown. Polyethylene naphthalate proved to be a suitable detector material for the dosimetry of ophthalmic plaques, including low-energy photon emitters and other small radiation fields. Due to superior properties, it has the potential to replace polyvinyltoluene as the standard scintillator for such applications.

  10. Technical basis for external dosimetry at the Waste Isolation Pilot Plant (WIPP)

    International Nuclear Information System (INIS)

    Bradley, E.W.; Wu, C.F.; Goff, T.E.

    1993-01-01

    The WIPP External Dosimetry Program, administered by Westinghouse Electric Corporation, Waste Isolation Division, for the US Department of Energy (DOE), provides external dosimetry support services for operations at the Waste Isolation Pilot Plant (WIPP) Site. These operations include the receipt, experimentation with, storage, and disposal of transuranic (TRU) wastes. This document describes the technical basis for the WIPP External Radiation Dosimetry Program. The purposes of this document are to: (1) provide assurance that the WIPP External Radiation Dosimetry Program is in compliance with all regulatory requirements, (2) provide assurance that the WIPP External Radiation Dosimetry Program is derived from a sound technical base, (3) serve as a technical reference for radiation protection personnel, and (4) aid in identifying and planning for future needs. The external radiation exposure fields are those that are documented in the WIPP Final Safety Analysis Report

  11. Thermoluminescence properties of irradiated commercial color pencils for accidental retrospective dosimetry

    International Nuclear Information System (INIS)

    Meriç, Niyazi; Şahiner, Eren; Bariş, Aytaç; Polymeris, George S.

    2015-01-01

    Color pencils are widely used mostly in kindergartens, in schools and could be found in all houses with families having young children. Their wide spread use in modern times as well as their chemical composition, consisting mostly of Si and Al, constitute two strong motivations towards exploiting their use as accidental retrospective thermoluminescent dosimeters. The present manuscript reports on the study of colored pencils manufactured by a commercial brand in China which is very common throughout Turkey. The preliminary results discussed in the present work illustrated encouraging characteristics, such as the presence of a trapping level giving rise to natural TL in a temperature range that is sufficiently high. Specific thermoluminescence features of this peak, such as glow peak shape and analysis, anomalous fading, thermal quenching, reproducibility, linearity and recovery ability to low attributed doses were studied. The results suggest that the color pencils could be effectively used in the framework of retrospective thermoluminescent dosimetry with extreme caution, based on multiple aliquot protocols. - Highlights: • Thermoluminescence of the inner part of commercial colored pencils was studied. • The presence of a trapping level giving rise to natural TL at 260 °C was yielded. • Deco analysis, anomalous fading, thermal quenching, reproducibility, linearity and recovery ability of this peak were studied

  12. MO-B-BRB-02: 3D Dosimetry in the Clinic: IMRT Technique Validation in Sweden

    International Nuclear Information System (INIS)

    Ceberg, S.

    2016-01-01

    Full three-dimensional (3D) dosimetry using volumetric chemical dosimeters probed by 3D imaging systems has long been a promising technique for the radiation therapy clinic, since it provides a unique methodology for dose measurements in the volume irradiated using complex conformal delivery techniques such as IMRT and VMAT. To date true 3D dosimetry is still not widely practiced in the community; it has been confined to centres of specialized expertise especially for quality assurance or commissioning roles where other dosimetry techniques are difficult to implement. The potential for improved clinical applicability has been advanced considerably in the last decade by the development of improved 3D dosimeters (e.g., radiochromic plastics, radiochromic gel dosimeters and normoxic polymer gel systems) and by improved readout protocols using optical computed tomography or magnetic resonance imaging. In this session, established users of some current 3D chemical dosimeters will briefly review the current status of 3D dosimetry, describe several dosimeters and their appropriate imaging for dose readout, present workflow procedures required for good dosimetry, and analyze some limitations for applications in select settings. We will review the application of 3D dosimetry to various clinical situations describing how 3D approaches can complement other dose delivery validation approaches already available in the clinic. The applications presented will be selected to inform attendees of the unique features provided by full 3D techniques. Learning Objectives: L. John Schreiner: Background and Motivation Understand recent developments enabling clinically practical 3D dosimetry, Appreciate 3D dosimetry workflow and dosimetry procedures, and Observe select examples from the clinic. Sofie Ceberg: Application to dynamic radiotherapy Observe full dosimetry under dynamic radiotherapy during respiratory motion, and Understand how the measurement of high resolution dose data in an

  13. MO-B-BRB-01: 3D Dosimetry in the Clinic: Background and Motivation

    International Nuclear Information System (INIS)

    Schreiner, L.

    2016-01-01

    Full three-dimensional (3D) dosimetry using volumetric chemical dosimeters probed by 3D imaging systems has long been a promising technique for the radiation therapy clinic, since it provides a unique methodology for dose measurements in the volume irradiated using complex conformal delivery techniques such as IMRT and VMAT. To date true 3D dosimetry is still not widely practiced in the community; it has been confined to centres of specialized expertise especially for quality assurance or commissioning roles where other dosimetry techniques are difficult to implement. The potential for improved clinical applicability has been advanced considerably in the last decade by the development of improved 3D dosimeters (e.g., radiochromic plastics, radiochromic gel dosimeters and normoxic polymer gel systems) and by improved readout protocols using optical computed tomography or magnetic resonance imaging. In this session, established users of some current 3D chemical dosimeters will briefly review the current status of 3D dosimetry, describe several dosimeters and their appropriate imaging for dose readout, present workflow procedures required for good dosimetry, and analyze some limitations for applications in select settings. We will review the application of 3D dosimetry to various clinical situations describing how 3D approaches can complement other dose delivery validation approaches already available in the clinic. The applications presented will be selected to inform attendees of the unique features provided by full 3D techniques. Learning Objectives: L. John Schreiner: Background and Motivation Understand recent developments enabling clinically practical 3D dosimetry, Appreciate 3D dosimetry workflow and dosimetry procedures, and Observe select examples from the clinic. Sofie Ceberg: Application to dynamic radiotherapy Observe full dosimetry under dynamic radiotherapy during respiratory motion, and Understand how the measurement of high resolution dose data in an

  14. MO-B-BRB-03: 3D Dosimetry in the Clinic: Validating Special Techniques

    International Nuclear Information System (INIS)

    Juang, T.

    2016-01-01

    Full three-dimensional (3D) dosimetry using volumetric chemical dosimeters probed by 3D imaging systems has long been a promising technique for the radiation therapy clinic, since it provides a unique methodology for dose measurements in the volume irradiated using complex conformal delivery techniques such as IMRT and VMAT. To date true 3D dosimetry is still not widely practiced in the community; it has been confined to centres of specialized expertise especially for quality assurance or commissioning roles where other dosimetry techniques are difficult to implement. The potential for improved clinical applicability has been advanced considerably in the last decade by the development of improved 3D dosimeters (e.g., radiochromic plastics, radiochromic gel dosimeters and normoxic polymer gel systems) and by improved readout protocols using optical computed tomography or magnetic resonance imaging. In this session, established users of some current 3D chemical dosimeters will briefly review the current status of 3D dosimetry, describe several dosimeters and their appropriate imaging for dose readout, present workflow procedures required for good dosimetry, and analyze some limitations for applications in select settings. We will review the application of 3D dosimetry to various clinical situations describing how 3D approaches can complement other dose delivery validation approaches already available in the clinic. The applications presented will be selected to inform attendees of the unique features provided by full 3D techniques. Learning Objectives: L. John Schreiner: Background and Motivation Understand recent developments enabling clinically practical 3D dosimetry, Appreciate 3D dosimetry workflow and dosimetry procedures, and Observe select examples from the clinic. Sofie Ceberg: Application to dynamic radiotherapy Observe full dosimetry under dynamic radiotherapy during respiratory motion, and Understand how the measurement of high resolution dose data in an

  15. MO-B-BRB-03: 3D Dosimetry in the Clinic: Validating Special Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Juang, T. [Stanford Cancer Center (United States)

    2016-06-15

    Full three-dimensional (3D) dosimetry using volumetric chemical dosimeters probed by 3D imaging systems has long been a promising technique for the radiation therapy clinic, since it provides a unique methodology for dose measurements in the volume irradiated using complex conformal delivery techniques such as IMRT and VMAT. To date true 3D dosimetry is still not widely practiced in the community; it has been confined to centres of specialized expertise especially for quality assurance or commissioning roles where other dosimetry techniques are difficult to implement. The potential for improved clinical applicability has been advanced considerably in the last decade by the development of improved 3D dosimeters (e.g., radiochromic plastics, radiochromic gel dosimeters and normoxic polymer gel systems) and by improved readout protocols using optical computed tomography or magnetic resonance imaging. In this session, established users of some current 3D chemical dosimeters will briefly review the current status of 3D dosimetry, describe several dosimeters and their appropriate imaging for dose readout, present workflow procedures required for good dosimetry, and analyze some limitations for applications in select settings. We will review the application of 3D dosimetry to various clinical situations describing how 3D approaches can complement other dose delivery validation approaches already available in the clinic. The applications presented will be selected to inform attendees of the unique features provided by full 3D techniques. Learning Objectives: L. John Schreiner: Background and Motivation Understand recent developments enabling clinically practical 3D dosimetry, Appreciate 3D dosimetry workflow and dosimetry procedures, and Observe select examples from the clinic. Sofie Ceberg: Application to dynamic radiotherapy Observe full dosimetry under dynamic radiotherapy during respiratory motion, and Understand how the measurement of high resolution dose data in an

  16. MO-B-BRB-01: 3D Dosimetry in the Clinic: Background and Motivation

    Energy Technology Data Exchange (ETDEWEB)

    Schreiner, L. [Cancer Center of Southeastern Ontario (Canada)

    2016-06-15

    Full three-dimensional (3D) dosimetry using volumetric chemical dosimeters probed by 3D imaging systems has long been a promising technique for the radiation therapy clinic, since it provides a unique methodology for dose measurements in the volume irradiated using complex conformal delivery techniques such as IMRT and VMAT. To date true 3D dosimetry is still not widely practiced in the community; it has been confined to centres of specialized expertise especially for quality assurance or commissioning roles where other dosimetry techniques are difficult to implement. The potential for improved clinical applicability has been advanced considerably in the last decade by the development of improved 3D dosimeters (e.g., radiochromic plastics, radiochromic gel dosimeters and normoxic polymer gel systems) and by improved readout protocols using optical computed tomography or magnetic resonance imaging. In this session, established users of some current 3D chemical dosimeters will briefly review the current status of 3D dosimetry, describe several dosimeters and their appropriate imaging for dose readout, present workflow procedures required for good dosimetry, and analyze some limitations for applications in select settings. We will review the application of 3D dosimetry to various clinical situations describing how 3D approaches can complement other dose delivery validation approaches already available in the clinic. The applications presented will be selected to inform attendees of the unique features provided by full 3D techniques. Learning Objectives: L. John Schreiner: Background and Motivation Understand recent developments enabling clinically practical 3D dosimetry, Appreciate 3D dosimetry workflow and dosimetry procedures, and Observe select examples from the clinic. Sofie Ceberg: Application to dynamic radiotherapy Observe full dosimetry under dynamic radiotherapy during respiratory motion, and Understand how the measurement of high resolution dose data in an

  17. MO-B-BRB-02: 3D Dosimetry in the Clinic: IMRT Technique Validation in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Ceberg, S. [Lund University (Sweden)

    2016-06-15

    Full three-dimensional (3D) dosimetry using volumetric chemical dosimeters probed by 3D imaging systems has long been a promising technique for the radiation therapy clinic, since it provides a unique methodology for dose measurements in the volume irradiated using complex conformal delivery techniques such as IMRT and VMAT. To date true 3D dosimetry is still not widely practiced in the community; it has been confined to centres of specialized expertise especially for quality assurance or commissioning roles where other dosimetry techniques are difficult to implement. The potential for improved clinical applicability has been advanced considerably in the last decade by the development of improved 3D dosimeters (e.g., radiochromic plastics, radiochromic gel dosimeters and normoxic polymer gel systems) and by improved readout protocols using optical computed tomography or magnetic resonance imaging. In this session, established users of some current 3D chemical dosimeters will briefly review the current status of 3D dosimetry, describe several dosimeters and their appropriate imaging for dose readout, present workflow procedures required for good dosimetry, and analyze some limitations for applications in select settings. We will review the application of 3D dosimetry to various clinical situations describing how 3D approaches can complement other dose delivery validation approaches already available in the clinic. The applications presented will be selected to inform attendees of the unique features provided by full 3D techniques. Learning Objectives: L. John Schreiner: Background and Motivation Understand recent developments enabling clinically practical 3D dosimetry, Appreciate 3D dosimetry workflow and dosimetry procedures, and Observe select examples from the clinic. Sofie Ceberg: Application to dynamic radiotherapy Observe full dosimetry under dynamic radiotherapy during respiratory motion, and Understand how the measurement of high resolution dose data in an

  18. High sensitivity of Indian summer monsoon to Middle East dust absorptive properties.

    Science.gov (United States)

    Jin, Qinjian; Yang, Zong-Liang; Wei, Jiangfeng

    2016-07-28

    The absorptive properties of dust aerosols largely determine the magnitude of their radiative impacts on the climate system. Currently, climate models use globally constant values of dust imaginary refractive index (IRI), a parameter describing the dust absorption efficiency of solar radiation, although it is highly variable. Here we show with model experiments that the dust-induced Indian summer monsoon (ISM) rainfall differences (with dust minus without dust) change from -9% to 23% of long-term climatology as the dust IRI is changed from zero to the highest values used in the current literature. A comparison of the model results with surface observations, satellite retrievals, and reanalysis data sets indicates that the dust IRI values used in most current climate models are too low, tending to significantly underestimate dust radiative impacts on the ISM system. This study highlights the necessity for developing a parameterization of dust IRI for climate studies.

  19. PRODUCTION, DIELECTRIC PROPERTY AND MICROWAVE ABSORPTION PROPERTY OF SiC(Fe SOLID SOLUTION POWDER BY SOL-GEL METHOD

    Directory of Open Access Journals (Sweden)

    XIAOLEI SU

    2014-03-01

    Full Text Available SiC(Fe solid solution powders were synthesized by sol–gel method under different reaction time, using methyltriethoxysilane as the silicon and carbon source and analytic ferric chloride as the dopant, respectively. The synthesized powders have been characterized by XRD, SEM and Raman spectra. Results show that the lattice constant decreases with increasing reaction time. The electric permittivities of SiC samples were determined in the frequency range of 8.2 ~ 12.4 GHz. Results show that the permittivity of SiC decreases with increasing reaction time. The SiC(Fe solid solution powder with reaction time of 4 h with 2 mm thickness exhibit the best microwave absorption property in X-band range (8.2 - 12.4 GHz. The microwave absorption mechanism has been discussed.

  20. Nonlinear absorption properties of some 1,4,8,11,15,18,22,25-octaalkylphthalocyanines and their metallated derivatives

    OpenAIRE

    BLAU, WERNER

    2003-01-01

    PUBLISHED The third-order nonlinear optical properties of a series of 15 unmetallated and metallated 1,4,8,11,15,18,22,25-octaalkylphthalocyanines have been investigated. The palladium-metallated compound is the strongest nonlinear absorber of the series, but, due to its comparatively high linear absorption coefficient, it exhibits a relatively low ratio of excited- to ground-state absorption cross-sections (?) when compared to the other compounds. The highest values for ? were found for d...

  1. Properties of light absorption in a highly coloured estuarine system in south-east Australia which is prone to blooms of the toxic dinoflagellate Gymnodinium catenatum

    Science.gov (United States)

    Clementson, Lesley A.; Parslow, John S.; Turnbull, Alison R.; Bonham, Pru I.

    2004-05-01

    The Huon Estuary in south-east Tasmania is an important site in Australia's aquaculture and finfish industries. Atlantic salmon and shellfish are farmed in the Huon River Estuary, which drains a catchment that includes both areas of pristine wilderness and agriculture. The estuary experiences algal blooms, including blooms of the toxic dinoflagellate Gymnodinium catenatum, which can cause considerable problems for the aquaculture industry. The freshwater input is highly coloured due to high levels of humic material and this combined with intrusions of clearer oceanic water and the occurrence of algal blooms makes this estuary optically complex. Between November 1996 and September 1998 samples for pigment and optical analyses were collected weekly from five sites within the mid to lower regions of the estuary. In addition, every three months (beginning July 1996), samples were collected from 30 sites within the full river/estuary system. Early in December 1997 a bloom of Gymnodinium catenatum occurred throughout the estuary and persisted until June 1998. Chromophoric dissolved organic matter (CDOM) was found to dominate the total absorption of the water throughout the entire estuary and over the two-year duration of the study. The occurrence of algal blooms showed no correlation with the optical characteristics of the estuary, suggesting that optical parameters cannot be used to predict the occurrence of algal blooms in this estuary. Blooms of different algal species, such as diatoms and dinoflagellates, may be able to be distinguished by their absorption spectra in the UV region rather than the visible region. To date, this study is the most detailed spatial and temporal study of the characteristics of light absorption in an estuarine system within Australia.

  2. The low-ion QSO absorption-line systems

    International Nuclear Information System (INIS)

    Lanzetta, K.M.

    1988-01-01

    Various techniques are used to investigate the class of QSO absorption-line systems that exhibit low-ion absorption lines. Four separate investigations are conducted as follows: Spectroscopy of 32 QSOs at red wavelengths is presented and used to investigate intermediate-redshift MgII absorption. A total of 22 Mg II doublets are detected, from which properties of the Mg II absorbers are derived. Marginal evidence for intrinsic evolution of the number density of the Mg II absorbers with redshift is found. The data are combined with previous observations of C IV and C II seen in the same QSOs at blue wavelengths, and the properties of Mg II- and C IV-selected systems are compared. A sample is constructed of 129 QSOs for which are available published data suitable for detecting absorption-line systems that are optically thick to Lyman continuum radiation. A total of 53 such Lyman-limit systems are found, from which properties of the Lyman-limit systems are derived. It is found that the rate of incidence of the systems does not strongly evolved with redshift. This result is contrasted with the evolution found previously for systems selected on the basis of Mg II absorption. Spectroscopy at red wavelengths of eight QSOs with known damped Lyα absorption systems is presented. Spectroscopic and spectrophotometric observations aimed at detecting molecular hydrogen and dust in the z = 2.796 damped Lyα absorber toward Q1337 + 113 are presented

  3. CaSO4:Dy and/or Tm: study of its properties for dosimetry application

    International Nuclear Information System (INIS)

    Ferreira, M.M.

    1979-01-01

    In order obtain in practical and cheap solid state dosimeter with high sensitivity, a technique initially developed to cold press a mixture of suitable materials in their powder form sensitive to radiation. The material initially used was natural CaF 2 (fluorite) for this salt was extensively studied in radiation dosimetry since it shows a thermoluminescent (TL) effect after radiation. However, natural calcium fluorite shows two main disadvantages: its high senstivity to room light and the impossibility to control its impurity content due to its natural origin. Calcium sulphate was thus used as a good substitute of fluorite. Rare earths doped calcium sulphate shows a high TL sensitivity and is not disturbed by light. It is also easily obtained in the laboratory under controlled conditions so to get reproducible impurity content. The best dosimeters that can be produced with rare earth doped calcium sulphate are CaSO 4 :Dy and CaSO 4 :Tm. Calcium sulphate, simultaneously doped with Tm and Dy was produced and 100% increase was obtained in the TL sensitivity when compared with the individually are earth doped calcium sulphate. (Author) [pt

  4. Variation in light absorption properties of mentha aquatica L. as a function of leaf form: Implications for plant growth

    DEFF Research Database (Denmark)

    Enriquez, Susana; Jensen, Kaj Sand

    2008-01-01

    To understand the association between leaf form and leaf optical properties, we examined light absorption variations in the leaves of Mentha aquatica L., an amphibious freshwater macrophyte. Specific absorption of leaves of M. aquatica showed a 7.5-fold variation, decreasing as pigment per unit...... area increased. This relationship indicates that dispersive samples, such as leaves, although efficient light traps, can also be affected by the "package effect." Mentha aquatica leaves, by expanding their biomass (increased specific leaf area [SLA]), improve their light absorption efficiency per unit...... of both pigment and leaf biomass. Changes in leaf biomass expansion were mainly a result of changes in leaf density, and as a consequence, leaf density appears to be a better descriptor of light absorption efficiency in M. aquatica leaves than does leaf thickness. Light absorption efficiency per unit...

  5. The program of international intercomparison of accident dosimetry

    International Nuclear Information System (INIS)

    2002-06-01

    The French institute of radioprotection and nuclear safety (IRSN) has carried out in June 2002 an international intercomparison program for the testing of the physical and biological accident dosimetry techniques. The intercomparison is jointly organized by the IRSN and the OECD-NEA with