WorldWideScience

Sample records for fast osl component

  1. The fast ratio: A rapid measure for testing the dominance of the fast component in the initial OSL signal from quartz

    International Nuclear Information System (INIS)

    Durcan, Julie A.; Duller, Geoff A.T.

    2011-01-01

    The signal from the fast component is usually considered preferable for quartz optically stimulated luminescence (OSL) dating, however its presence in a continuous wave (CW) OSL signal is often assumed, rather than verified. This paper presents an objective measure (termed the fast ratio) for testing the dominance of the fast component in the initial part of a quartz OSL signal. The ratio is based upon the photo ionisation cross-sections of the fast and medium components and the power of the measurement equipment used to record the OSL signal, and it compares parts of the OSL signal selected to represent the fast and medium components. The ability of the fast ratio to distinguish between samples whose CW-OSL signal is dominated by the fast and non-fast components is demonstrated by comparing the fast ratio with the contribution of the fast component calculated from curve deconvolution of measured OSL signals and from simulated data. The ratio offers a rapid method for screening a large number of OSL signals obtained for individual equivalent dose estimates, it can be calculated and applied as easily as other routine screening methods, and is transferrable between different aliquots, samples and measurement equipment. - Highlights: → Fast ratio is a measure which tests dominance of fast component in quartz OSL signals. → A fast ratio above 20 implies a CW-OSL signal is dominated by fast component. → Fast ratio can be easily and rapidly applied to a large number of OSL signals. → Uses include signal comparison, data screening, identify need for further analysis.

  2. The correlation of fast OSL component with the TL peak at 3250C in quartz of various origins

    International Nuclear Information System (INIS)

    Kitis, G.; Kiyak, N.; Polymeris, G.S.; Tsirliganis, N.C.

    2010-01-01

    The fast component of the optically stimulated luminescence (OSL) signal in quartz is the basic tool for the optical dating. Its relation with the thermoluminescence (TL) glow-peak at about 325 deg. C is well established for naturally irradiated quartz. This relationship is also an important part of a general model for quartz on which many theoretical simulations of various OSL experimental results have been based. In the present work this relationship is systematically investigated in nine quartz samples of different origin. The linearly modulated OSL (LM-OSL) curves of all quartz samples for stimulation time less than 50 s consists of two components discriminated easily by a computerized curve deconvolution (CCD) analysis. By comparing the un-bleached to the respective bleached TL glow-curve, it is found that the system of these two fast OSL components is directly related with only a small portion of the electron traps responsible for the TL glow-peaks in the temperature region 200-400 0 C. By increasing the stimulation times, besides the two fast components, the medium and the slow components are also obtained. The medium and slow components are clearly related with the main body of the electron traps responsible for TL glow-peaks in the same temperature region 200-400 0 C. Despite their different origin all quartz samples show an appreciable homogeneity concerning the number and time position of the individual components, whereas, the relative TL/OSL intensities vary strongly from sample to sample with the integrated TL intensity being generally much less than the integrated OSL intensity.

  3. A single-aliquot regenerative-dose method based on IR (1.49 eV) bleaching of the fast OSL component in quartz

    DEFF Research Database (Denmark)

    Jain, M.; Murray, A.S.; Bøtter-Jensen, L.

    2005-01-01

    In the optically stimulated luminescence (OSL) dating of quartz, the presence of significant medium and slow components in the initial-OSL signal (first 0.8 s or so) can give rise to erroneous dose estimates. Thus it is desirable to develop a dose estimation method that is based on the OSL from t...

  4. The origin of the medium OSL component in West Australian quartz

    International Nuclear Information System (INIS)

    Wang, X.L.; Du, J.H.; Adamiec, G.; Wintle, A.G.

    2015-01-01

    Optically stimulated luminescence (OSL) of a coarse-grained sedimentary quartz from West Australia was investigated. Observations of OSL and TL (thermoluminescence) were made following a series of experiments using different heating and optical bleaching conditions, and with optical stimulation at several different temperatures. Analysis of the fast and medium OSL components suggests that the medium OSL component observed after heating at 260 °C is a by-product of the production of the fast component, and both of them have as their original source the 325 °C TL trap. During fast OSL production following irradiation and preheating, some of the electrons evicted into the conduction band are re-trapped in an intermediate trap corresponding to the 170 °C TL peak; from here they are instantaneously stimulated to give rise to the medium OSL signal when the blue light stimulation is switched on, and subsequently result in the residual recuperated TL after the blue light is switched off. The kinetic properties of the medium OSL component are determined by the properties of both the 170 °C and 325 °C TL traps in contrast to the conventional interpretation of the medium component being derived from an independent source trap. Therefore, the 170 °C TL trap also plays unexpected roles in quartz OSL production with elevated stimulation temperatures (e.g. 125 °C or 130 °C, currently used for OSL dating), while the 110 °C TL trap and its influences are being avoided. - Highlights: • Quartz medium OSL component is a by-product of fast OSL component production. • Medium component is mediated by the 170 C TL peak. • Phototransfer is responsible for the medium OSL

  5. Relative response of TL and component-resolved OSL to alpha and beta radiations in annealed sedimentary quartz

    International Nuclear Information System (INIS)

    Polymeris, George S.; Afouxenidis, Dimitrios; Raptis, Spyridoula; Liritzis, Ioannis; Tsirliganis, Nestor C.; Kitis, George

    2011-01-01

    Knowledge of the relative luminescence response to alpha and beta radiation is very important in TL and OSL dating. In the present study the relative alpha to beta response is studied in a sedimentary quartz sample, previously fired at 900 deg. C for 1 h, in the dose region between 1 and 128 Gy, for both thermoluminescence (TL) and linearly modulated optically stimulated luminescence (LM - OSL). The LM - OSL measurements were performed at room temperature and at 125 deg. C. All OSL signals were deconvolved into their individual components. Comparison of OSL curves after alpha and beta irradiation strongly supports that quartz OSL components follow first order kinetics in both cases. In the case of TL, the relative alpha to beta response is found to be very different for each TL glow-peak, but it does not depend strongly on irradiation dose. In the case of LM - OSL measurements, it is found that the relative behaviour of the alpha to beta response is different for three distinct regions, namely the fast OSL component, the region of medium OSL component originating from the TL glow-peak at 110 deg. C when stimulation takes place at room temperature and finally the region of slow OSL component. Following stimulation at ambient temperature, the relative alpha to beta response of all components was not observed to depend significantly on dose, with the value of ratio being 0.03 and a tendency to decrease with increasing dose. However, in the case of measurements performed at 125 deg. C, the relative response of the fast components is much enhanced, and for the remaining components it increases with increasing dose. Special care must be taken to examine the relative alpha to beta response of the fast component at 125 deg. C which contrasts the relative response of the TL peak at ca. 325 deg. C. The implications for the dating of annealed quartz are also briefly discussed. - Highlights: → Relative alpha to beta response for TL and LM-OSL is studied in annealed

  6. Retrospective dosimetry using Japanese brick quartz: A way forward despite an unstable fast decaying OSL signal

    DEFF Research Database (Denmark)

    Fujita, Hiroki; Jain, Mayank; Murray, A.S.

    2011-01-01

    signals has been carried out towards identification of common source traps. It is observed that OSL from Japanese brick quartz shows unusual luminescence characteristics; in particular, the initial fast decaying OSL signal contains a dominant (>90%) thermally unstable component related to the 85 °C TL...... peak, which necessitates a prior heat treatment. A single-aliquot regenerative-dose (SAR) protocol is developed and tested using thermal treatments intended to isolate a stable dosimetric signal. A minimum detection limit of 65 mGy is then estimated using this protocol. Following irradiation using 60Co...... of Japanese brick quartz examined here can be used to derive precise estimates of accident dose, and, possibly to distinguish between sources of gamma radiation in a nuclear accident. To our knowledge, this is the first report on the existence of an unstable fast decaying OSL signal in quartz derived from...

  7. Component resolved bleaching study in natural calcium fluoride using CW-OSL, LM-OSL and residual TL glow curves after bleaching

    International Nuclear Information System (INIS)

    Angeli, Vasiliki; Polymeris, George S.; Sfampa, Ioanna K.; Tsirliganis, Nestor C.; Kitis, George

    2017-01-01

    Natural calcium fluoride has been commonly used as thermoluminescence (TL) dosimeter due to its high luminescence intensity. The aim of this work includes attempting a correlation between specific TL glow curves after bleaching and components of linearly modulated optically stimulated luminescence (LM-OSL) as well as continuous wave OSL (CW-OSL). A component resolved analysis was applied to both integrated intensity of the RTL glow curves and all OSL decay curves, by using a Computerized Glow-Curve De-convolution (CGCD) procedure. All CW-OSL and LM-OSL components are correlated to the decay components of the integrated RTL signal, apart from two RTL components which cannot be directly correlated with either LM-OSL or CW-OSL component. The unique, stringent criterion for this correlation deals with the value of the decay constant λ of each bleaching component. There is only one, unique bleaching component present in all three luminescence entities which were the subject of the present study, indicating that each TL trap yields at least three different bleaching components; different TL traps can indicate bleaching components with similar values. According to the data of the present work each RTL bleaching component receives electrons from at least two peaks. The results of the present study strongly suggest that the traps that contribute to TL and OSL are the same. - Highlights: • A component resolved bleaching study was attempted to CaF_2:N in terms of CW-OSL, LM-OSL and RTL. • Bleaching decay constants originating from different TL peaks yield overlapping values. • Three to five individual components were used in order to describe the bleaching behavior in all luminescence entities. • There is only one, unique bleaching component present in all three luminescence entities.

  8. On the OSL curve shape and preheat treatment of electronic components from portable electronic devices

    DEFF Research Database (Denmark)

    Woda, Clemens; Greilich, Steffen; Beerten, Koen

    2010-01-01

    The shape of the OSL decay curve and the effect of longer time delays between accidental exposure and readout of alumina-rich electronic components from portable electronic devices are investigated. The OSL decay curve follows a hyperbolic decay function, which is interpreted as an approximation ...

  9. Quartz fast component opticallystimulated luminescence: Towards routine extraction for dating applications

    International Nuclear Information System (INIS)

    Shen, Zhixiong; Lang, Andreas

    2016-01-01

    Using an uncontaminated fast component is a key for improving the reliability of quartz OSL dating for many deposits. So far no approach to extract the fast component of quartz OSL has routinely been adopted for dating practice. Key challenges for extracting fast components are (1) the difficulty of finding a unique solution in curve-fitting deconvolution of OSL decay curves and (2) the relatively poor dating precision when using experimental fast component extraction. Here, a simple mathematic solution for fast component extraction is presented that is not relying on curve-fitting deconvolution and can easily be adopted into routine dating practices. By using specifically selected data points from smoothed OSL decay curves, the precision of equivalent doses calculated using the extracted fast component can be improved over equivalent doses calculated using bulk OSL. The fast component extraction is tested on a group of age-constrained samples containing both insufficiently bleached and sufficiently bleached deposits. Fast component OSL ages are as accurate as bulk OSL ages for the sufficiently bleached deposits, but more accurate for samples where bulk OSL is affected by insufficient bleaching. We also demonstrate how using a curve smoothing procedure can improve dating precision in case of both sufficiently and insufficiently bleached deposits. - Highlights: • A simple mathematical method to extract quartz OSL fast component is presented. • The method can be adopted in D_e calculation programs for routine extraction. • The method leads to an increase in accuracy and precision of D_e. • The method works for relatively dim samples with low signal-to-noise ratios.

  10. Retrospective radiation dosimetry using OSL of electronic components: Results of an inter-laboratory comparison

    International Nuclear Information System (INIS)

    Bassinet, C.; Woda, C.; Bortolin, E.; Della Monaca, S.; Fattibene, P.; Quattrini, M.C.; Bulanek, B.; Ekendahl, D.; Burbidge, C.I.; Cauwels, V.; Kouroukla, E.; Geber-Bergstrand, T.; Mrozik, A.; Marczewska, B.; Bilski, P.; Sholom, S.; McKeever, S.W.S.; Smith, R.W.; Veronese, I.

    2014-01-01

    In the framework of the EU-FP7 MULTIBIODOSE project, two protocols using OSL of resistors removed from the circuit board of mobile phones were developed with the aim to use the resistors as fortuitous dosimeters in the event of a large scale radiological accident. This paper presents the results of an inter-laboratory comparison carried out under the umbrella of EURADOS. The two aims of this exercise were the validation of the MULTIBIODOSE protocols by a large number of laboratories and the dissemination of the method with the objective of preparing the basis for a network that could increase Europe's response capacity in the case of a mass casualty radiological emergency. Twelve institutes from eleven European countries and one institute from the USA, with various degrees of expertise in OSL dosimetry, took part in the OSL inter-laboratory comparison. Generally, a good agreement within uncertainties was observed between estimated and nominal doses. - Highlights: • Resistors in mobile phones could function as reliable fortuitous dosimeters in case of a large scale radiological accident. • Two OSL protocols were validated by an inter-laboratory comparison. • It is feasible to set up a network of laboratories so as to increase the measurement capacity

  11. Luminescence characteristics of quartz from the Southern Kenyan Rift Valley: Dose estimation using LM-OSL SAR

    International Nuclear Information System (INIS)

    Choi, J.H.; Duller, G.A.T.; Wintle, A.G.; Cheong, C.-S.

    2006-01-01

    Linearly modulated (LM) optically stimulated luminescence (OSL) measurements have revealed that some sedimentary quartz samples from the Kenyan Rift Valley do not have a fast OSL component, but contain a medium component and several slow components. It was impossible to recover a known dose for these samples using the conventional single-aliquot regenerative-dose (SAR) procedure. The dose-response curves and continuous wave (CW) OSL decay curves for these samples showed several undesirable properties for dating. We have compared various luminescence characteristics of these samples with other quartz samples from elsewhere in the world for which the SAR procedure has been shown to be appropriate; the latter were dominated by a fast OSL component. The characteristics include photoionisation cross-sections for each component and the relative proportions of the different components in the initial and total OSL signals. It was found that those samples that had greater than 90% of the initial 0.8 s of their OSL signal from the fast component were suitable for dating using the conventional SAR protocol. A novel method of displaying the relative contributions of the different OSL components in a ternary diagram is proposed. The thermal stability of each component was investigated using pulse-annealing experiments. We then examined the possibility of applying an LM-OSL SAR protocol to samples that have a substantial medium component

  12. Application of pulsed OSL to the separation of the luminescence components from a mixed quartz/feldspar sample

    International Nuclear Information System (INIS)

    Denby, P.M.; Botter-Jensen, L.; Murray, A.S.; Thomsen, K.J.; Moska, P.

    2006-01-01

    It is known that the pulsed optically stimulated luminescence (OSL) characteristics of quartz and feldspars are very different. These differences can be used to preferentially discriminate against the feldspar signal in mixed quartz-bar feldspar mineral assemblages, or in separated quartz contaminated with a feldspar signal. We have developed instrumentation for the study of high-speed pulse stimulated OSL. Our system uses the standard blue/IR LED stimulation unit of a Riso reader (allowing stimulation pulses down to 1-2μs duration) and can thus be applied to the routine analysis of samples. Using this stimulation source, and high-speed photon timing, the OSL yield can be monitored throughout the pulsing cycle and subsequent OSL decay. It is found that the total photon yield per unit stimulation power in pulsed mode is, for quartz, twice and, for feldspar, nearly four times, that in continuous wave mode. Observation of this OSL signal, between stimulation pulses, is seen to be characteristic of the mineral being examined, and has been used to preferentially discriminate against feldspar contamination in a mixed quartz/feldspar sample. Simple implementation of this technique by gating the counting period, so that counts are only accumulated during a windowed period, reduces the feldspar signal to 1.6% of its original value relative to that of the quartz

  13. Inorganic component of saliva during fasting and after fast break

    OpenAIRE

    Samad, Rasmidar

    2016-01-01

    Oral health is closely related to salivary components. Saliva consists of water, inorganic and organic materials. Fasting changes one???s meal and drinking time that in turn can affect the environment in oral cavity, including inorganic componenet of saliva. The purpose of this study is to determine the inorganic component of saliva during fasting and after fast break.

  14. More on the TR-OSL signal from BeO ceramics

    International Nuclear Information System (INIS)

    Bulur, Enver

    2014-01-01

    Time Resolved Optically Stimulated Luminescence (TR-OSL) from BeO ceramics was investigated using blue (445 nm) and near-IR light (852 nm) for stimulation. Stimulation spectrum of the TR-OSL signal – as measured in the interval 700 to 420 nm- was observed to increase monotonically with the decreasing stimulation wavelength. In addition to the “fast” and “slow” components observed with blue light stimulation, IR stimulated TR-OSL spectra of irradiated BeO ceramics were observed to have two components with average lifetimes around ∼2.5 μs and ∼17 μs. Emission spectra of the both IR stimulated TR-OSL components were observed to have a broad emission band peaking around 330 nm. Thermal stability of the IR stimulated TR-OSL signal was studied by making preheating experiments in the range from 100 °C to 190 °C. It was observed that the IR stimulated OSL signal is stable up to ∼150 °C and decay afterwards. Radiation dose response of the IR stimulated luminescence signal was obtained in the range from 5 to 500 Gy. Both blue and IR stimulated TR-OSL signals grew up to 100 Gy and exhibited saturation for higher doses. Additionally, measurement temperature dependence of the components was also investigated and for the ∼2 μs component thermal assistance with activation energy around 0.16 eV was observed. It seems that the fast component of the blue stimulated TR-OSL component can be correlated to the ∼2 μs IR stimulated TR-OSL component. - Highlights: • IR Stimulated Time-Resolved OSL from BeO was studied. • Two components with lifetimes ∼2 and ∼17us were observed. • IR stimulated TR-OSL signal is found to be stable up to 150 °C. • Thermal quenching energy of the 2us component was found as 0.16 eV

  15. OSL Age Determination of the Hearths in a Bronze Age Dwelling Site by using Bayesian Statistics

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myung Jin [Neosiskorea Co. Ltd., Seoul (Korea, Republic of); Yang, Hye Jin [Baekje Cultural Properties Research Institute, Gongju (Korea, Republic of); Hong, Duk Geun [Kangwon National University, Chuncheon (Korea, Republic of)

    2011-06-15

    OSL dating for three hearths having the sequence of use and discard in No. 29 and 29-1 dwelling sites at Sogol cultural site was carried out. Resulting from the deconvolution of natural CW-OSL decay curve and thermal zeroing test, it was turned out that OSL signal was entirely composed of the heat- and light-sensitive fast component with high photoionization cross-section and all quartz OSL signals were thermally bleached under 300 .deg. C which is the minimum temperature related to heating and cooking in Bronze age. After dose recovery test and plateau test, paleodose of each hearth sample was evaluated by using SAR method, and OSL age was determined from the ratio of paleodose to annual dose rate. For the purpose of the precision improvement of OSL age, Bayesian statistics was applied to each hearth's age and the archaeological sequence information. Finally, it could be concluded to the accurate use period of each hearth from the resultant OSL ages.

  16. OSL Age Determination of the Hearths in a Bronze Age Dwelling Site by using Bayesian Statistics

    International Nuclear Information System (INIS)

    Kim, Myung Jin; Yang, Hye Jin; Hong, Duk Geun

    2011-01-01

    OSL dating for three hearths having the sequence of use and discard in No. 29 and 29-1 dwelling sites at Sogol cultural site was carried out. Resulting from the deconvolution of natural CW-OSL decay curve and thermal zeroing test, it was turned out that OSL signal was entirely composed of the heat- and light-sensitive fast component with high photoionization cross-section and all quartz OSL signals were thermally bleached under 300 .deg. C which is the minimum temperature related to heating and cooking in Bronze age. After dose recovery test and plateau test, paleodose of each hearth sample was evaluated by using SAR method, and OSL age was determined from the ratio of paleodose to annual dose rate. For the purpose of the precision improvement of OSL age, Bayesian statistics was applied to each hearth's age and the archaeological sequence information. Finally, it could be concluded to the accurate use period of each hearth from the resultant OSL ages

  17. Application of pulsed OSL to the separation of the luminescence components from a mixed quartz/feldspar sample

    DEFF Research Database (Denmark)

    Denby, Phil M.; Bøtter-Jensen, L.; Murray, A.S.

    2006-01-01

    with a feldspar signal. We have developed instrumentation for the study of high-speed pulse stimulated OSL. Our system uses the standard blue/IR LED stimulation unit of a Riso reader (allowing stimulation pulses down to 1-2 mu s duration) and can thus be applied to the routine analysis of samples. Using...... that counts are only accumulated during a windowed period, reduces the feldspar signal to 1.6% of its original value relative to that of the quartz. (c) 2006 Elsevier Ltd. All rights reserved....

  18. The TL and OSL study of hydroxyapatites for dosimetric applications

    International Nuclear Information System (INIS)

    Alencar, Marcus A. Vallim de

    2009-01-01

    The hydroxyapatite, the principal mineral component of the bone and tooth enamel, is one of the dosimetric materials that has distinguished itself in the high dose and accidents dosimetry, as well as in the dating, for the Electron Paramagnetic Resonance (EPR) technique. For this reason, the hydroxyapatite could also be used as Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) dosimeter in the dosimetry of high doses and accidents, and also in the archaeological and geological dating. This work presents a brief study of the TL and OSL behaviour of the B type synthetic carbonated hydroxyapatite, observing the possibility to use this material in TL and OSL dosimetry. The samples were irradiated to a dose of 100 Gy and 1000 Gy, and the TL and OSL measurements were obtained by the RISOE TL/OSL reader, model TL/OSL-DA-15B. The first results demonstrate the presence of three peaks in the TL glow curve in the temperatures of 100 deg C, 150 deg C and 280 deg C. The synthetic carbonated hydroxyapatite also presents an OSL signal when the sample is stimulated with blue light and a small OSL signal for stimulation with infrared light (IR). These results indicate the possibility of this synthetic carbonated hydroxyapatite to be used as dose indicator material using the TL and OSL techniques. (author)

  19. Creep buckling problems in fast reactor components

    International Nuclear Information System (INIS)

    Ramesh, R.; Damodaran, S.P.; Chellapandi, P.; Chetal, S.C.; Bhoje, S.B.

    1995-01-01

    Creep buckling analyses for two important components of 500 M We Prototype Fast Breeder Reactor (PFBR), viz. Intermediate Heat Exchanger (IHX) and Inner Vessel (IV), are reported. The INCA code of CASTEM system is used for the large displacement elasto-plastic-creep analysis of IHX shell. As a first step, INCA is validated for a typical benchmark problem dealing with the creep buckling of a tube under external pressure. Prediction of INCA is also compared with the results obtained using Hoff's theory. For IV, considering the prohibitively high computational cost for the actual analysis, a simplified analysis which involves only large displacement elastoplastic buckling analysis is performed using isochronous stress strain curve approach. From both of these analysis is performed using isochronous stress strain curve approach. From both of these analysis, it has been inferred that creep buckling failure mode is not of great concern in the design of PFBR components. It has also been concluded from the analysis that Creep Cross Over Curve given in RCC-MR is applicable for creep buckling failure mode also. (author). 8 refs., 9 figs., 1 tab

  20. Correlation between TL and OSL signals in KMgF3:Ce3+: Bleaching study of individual glow-peaks

    International Nuclear Information System (INIS)

    Dallas, G.I.; Polymeris, G.S.; Afouxenidis, D.; Tsirliganis, N.C.; Tsagas, N.F.; Kitis, G.

    2010-01-01

    KMgF 3 :Ce 3+ is an ultra sensitive Thermoluminescence (TL) material with a complex TL and OSL glow-curve structure. The aim of the present work is to attempt a one-to-one correspondence between specific TL glow-peaks and OSL components in KMgF 3 :Ce 3+ . The correlation study involves the deconvolution of the TL curves and the estimation of the bleaching decay constants for individual glow-peaks followed by the deconvolution of the LM-OSL curve using the estimated decay constants. It was found that the bleaching of each individual glow-peak takes place in three different rates; namely in a fast, medium and slow rate.

  1. The dependence of dose recovery experiments on the bleaching of natural quartz OSL using different light sources

    International Nuclear Information System (INIS)

    Choi, J.H.; Murray, A.S.; Cheong, C.-S.; Hong, S.C.

    2009-01-01

    In this paper, the dependence of dose recovery tests on the different bleaching light sources (blue-LEDs, solar simulator, natural sunlight) is investigated with a variety of sedimentary quartz samples, selected so that their OSL signals are dominated by the fast OSL component. We observed that when long solar simulator bleaching was applied, various known doses were underestimated in an SAR-based dose recovery test. However, when blue-LEDs and short solar simulator bleaching were used (10 s and 60 s) the known doses were accurately recovered. In repeated measurement of the OSL signals induced by the same regeneration and test dose, we observed a considerable increase in quartz OSL sensitivity during or after the first OSL measurement when long solar simulator bleaching was used; this seems to provide a possible explanation for the observed underestimation of the laboratory known doses. A series of experimental results using a sample from a modern aeolian dune surface shows that there are no subsequent sensitivity changes when the naturally zeroed samples are bleached with sunlight for long time. It seems that there is a dependence of the sensitivity change on the amount of dose administered before solar simulator bleaching and on the light intensity of solar simulator. When small doses were given to the naturally zeroed sample, the sensitivity change during or after the first OSL measurement was not significant. However, when a considerable amount of beta dose (∼4000 Gy) is administered to the sample, a clear sensitivity change during or after the first OSL measurement (∼20%) was observed. Such a sensitivity change was not observed when the bleaching light intensity of solar simulator was reduced by increasing the distance between samples and the UV lamp. Our results show that, at least for the samples described here, the outcomes of dose recovery experiments are dependent on the bleaching conditions.

  2. Utilisation of OSL from table salt in retrospective dosimetry

    International Nuclear Information System (INIS)

    Fujita, Hiroki; Jain, Mayank; Murray, Andrew S.

    2011-01-01

    Common salt (NaCl) has previously been suggested for use in dose estimation in accident dosimetry. In this study, we investigated the optically stimulated luminescence (OSL) and violet thermoluminescence (VTL) characteristics of 'Aji-Shio' (Ajinomoto), a Japanese commercial salt. A comparison of OSL and TL signals allowed identification of common source traps. The initial OSL signal contained a dominant thermally unstable component, which necessitated prior heat treatment. Based on these luminescence characteristics, a single-aliquot regenerative-dose (SAR) OSL protocol was modified and tested. The protocol worked very well for six types of salt, but not for four other types of salt. A minimum detection limit of ∼15 mGy was estimated using the OSL protocol; this is lower than the value obtained from other forms of OSL retrospective dosimetry and lower than that obtained using electron spin resonance (ESR) dosimetry. It was concluded that the OSL from Japanese commercial salt could be used successfully to derive precise estimates of accident dose. (author)

  3. Application of pulsed OSL to polymineral fine-grained samples

    International Nuclear Information System (INIS)

    Feathers, James K.; Casson, M. Aksel; Schmidt, Amanda Henck; Chithambo, Makaiko L.

    2012-01-01

    Pulsed OSL is applied to nine fine-grained sediment samples from Sichuan province, China, using stimulating pulses of 10 μs on and 240 μs off, with an infrared exposure prior to each OSL measurement. Comparison of fading rates between pulsed and non-pulsed signals, the latter also obtained with a preceding IR exposure, shows that fading is significant for mainly the non-pulsed signals. Presence of a pulsed IRSL and the magnitudes of b-value to correct for lower alpha efficiency suggest that pulsing does not fully remove a significant feldspar signal, only a fading component. Comparison with ages of quartz extracts shows that pulsed OSL ages are consistent, while CW-OSL ages are slightly older and CW-IRSL ages are much older. The older ages suggest a less well-bleached feldspar component.

  4. Coatings for fast breeder reactor components

    International Nuclear Information System (INIS)

    Johnson, R.N.

    1984-04-01

    Several types of metallurgical coatings are used in the unique environments of the fast breeder reactor. Most of the coatings have been developed for tribological applications, but some also serve as corrosion barriers, diffusion barriers, or radionuclide traps. The materials that have consistently given the best performance as tribological coatings in the breeder reactor environments have been coatings based on chromium carbide, nickel aluminide, or Tribaloy 700 (a nickel-base hard-facing alloy). Other coatings that have been qualified for limited applications include chromium plating for low temperature galling protection and nickel plating for radionuclide trapping

  5. OSL at elevated temperatures: Towards the simultaneous thermal and optical stimulation

    International Nuclear Information System (INIS)

    Polymeris, George S.

    2015-01-01

    In routine OSL dating measurements, a preheat procedure at high temperatures is used to empty the shallow traps. Thus no contribution from shallow traps was expected as each OSL measurement is subsequently performed at moderately high temperatures, around 110–125 °C. The present work attempts to consider the OSL measurements performed at elevated temperatures without any previous preheat as a case of simultaneous thermal and optical stimulation of the same trap. Towards this direction, a set of proposed equations is derived for all three different cases of optical stimulation modes, namely CW-OSL, LM-OSL as well as PS-LM-OSL. According to these equations, indicative features of thermally activated OSL processes are expected, such as the steepening of CW-OSL decay curves as either stimulation temperature or intensity increases, as well as the shifting of the stimulation time of the maximum intensity for both LM-OSL and PS-LM-OSL curves towards shorter times with increasing temperatures. Experimentally, specific measurement sequences after varying stimulation temperature and/or intensity were applied in order to estimate the values of associated trap parameters, such as activation energy and photo-ionization cross-section. Experimental OSL data from a milky natural quartz sample stand in good agreement of these theoretical considerations in the case of 110 °C TL peak and the intense OSL component C 2 monitored at RT. - Highlights: • OSL at elevated temperatures without preheat results from two simultaneous stimulation modes. • Equations were derived assuming of linear superposition of two stimulation modes. • Data for 110 °C TL peak and OSL C 2 at RT stand in agreement with these equations. • Results verify the linear superposition of the two stimulation modes

  6. Characterisation of blue-light stimulated luminescence components in different quartz samples: Implications for dose measurement

    DEFF Research Database (Denmark)

    Jain, M.; Murray, A.S.; Bøtter-Jensen, L.

    2003-01-01

    -aliquot dose-evaluation protocols seem to be relatively free of complications when applied to quartz dominated by the fast OSL component coming from 325degreesC TL region, but this may not be true for quartz in which other components are more significant. An adequate understanding of how different OSL...... results from measurement of (a) sensitisation, (b) thermal stability, (c) recuperation, and (d) infrared response as a function of stimulation temperature from 3 different samples of sedimentary quartz selected on the basis of relative OSL contribution from different blue light stimulated linearly...

  7. Assessing the completeness of optical resetting of quartz OSL in the natural environment

    International Nuclear Information System (INIS)

    Singarayer, J.S.; Bailey, R.M.; Ward, S.; Stokes, S.

    2005-01-01

    Resetting of previously accumulated optically stimulated luminescence (OSL) signals during transport of sediment is a fundamental requirement for reliable optical dating. The completeness of optical resetting of 46 modern-age quartz samples from a variety of depositional environments was examined. All equivalent dose (D e ) estimates were e from easy-to-bleach through to hard-to-bleach components. For all modern fluvial samples with non-zero D e values, SAR D e (t) analysis and component-resolved linearly modulated OSL (LM OSL) D e estimates showed this to be the case, implying incomplete resetting of previously accumulated charge. LM OSL measurements were also made to investigate the extent of bleaching of the slow components in the natural environment. In aeolian sediments examined, the natural LM OSL was effectively zero (i.e. all components were fully reset). The slow components of modern fluvial samples displayed measurable residual signals up to 15Gy

  8. Study of the OSL response of the CaF2:Dy (TLD-200) dosimeter

    International Nuclear Information System (INIS)

    Medeiros, Beatriz M.; Alencar, Marcus A.V. de

    2013-01-01

    The OSL dosimetry has become, in recent years, a successful technique in personal and environmental dosimetry due to high luminescence efficiency, excellent reproducibility, fast readout of signal and repeated and successive OSL measurements of the same dosimeter. Another factor that contributes to the increased use of OSL dosimetry is the use of the aluminum oxide doped with carbon (Al 2 O 3 :C) as dosimeter. Developed initially as thermoluminescent dosimeter, the Al 2 O 3 :C has an excellent OSL sensitivity, high efficiency, good linearity, low or no fading and excellent stability with respect to environmental conditions. However, the OSL dose response for aluminum oxide is linear only for low doses. For intermediate doses (doses in radiotherapy), the response is supralinear. For the values of high doses used in the processes of food irradiation and sterilization of surgical materials, the OSL signal of the aluminum oxide already saturated. Furthermore, the degree of supralinearity and the saturation value vary from sample to sample (∼ 30-300 Gy). Therefore, the use of aluminum oxide as OSL dosimeter is inappropriate in radiotherapy and in the irradiation industrial processes. The objective of this work is the study of the OSL properties of other dosimetric materials irradiated with values of intermediate and high dose to verify the applicability of the OSL dosimetry in radiotherapy and in the processes of food irradiation and sterilization of medical materials. The dosimetric material used in this work is the calcium fluoride doped with dysprosium (CaF 2 :Dy) produced by Harshaw and known commercially as TLD-200. The results demonstrate that the CaF 2 :Dy has OSL signal and the OSL dose response is linear in the range of 10 Gy to 300 Gy. Therefore, the dosimetry OSL with this dosimeter can be used in the evaluation of doses of the order of dozens to hundreds of grays. (author)

  9. Experimental Facilities for Performance Evaluation of Fast Reactor Components

    International Nuclear Information System (INIS)

    Chandramouli, S.; Kumar, V.A. Suresh; Shanmugavel, M.; Vijayakumar, G.; Vinod, V.; Noushad, I.B.; Babu, B.; Kumar, G. Padma; Nashine, B.K.; Rajan, K.K.

    2013-01-01

    Brief details about various experimental facilities catering to the testing and performance evaluation requirements of fast reactor components have been brought out. These facilities have been found to be immensely useful to continue research and development activities in the areas of component development and testing, sodium technology, thermal hydraulics and sodium instrumentation for the SFR’s. In addition new facilities which have been planned will be of great importance for the developmental activities related to future SFR’s

  10. Modelling the thermal bleaching of OSL signal in the case of a competition between recombination centres

    International Nuclear Information System (INIS)

    Chruscinska, A.

    2009-01-01

    The thermal bleaching of the optically stimulated luminescence (OSL) has been investigated by computer simulations for a model including three traps and two luminescence centres. The deepest trap is active only during the OSL process. Two other traps are active only during the thermal bleaching. The thermal bleaching effects on the OSL intensity as well as on the OSL curve shape are presented for the wide range of trap and luminescence centre parameters and for the different settings of optical detection window. The conventional OSL curve analysis consisting in decomposition of the OSL curve into first order components is applied to the simulation results and the optical cross section spectra obtained as a result of this analysis are compared with the model assumptions. The simulations show that OSL signal can decrease to undetectable level even when the traps related to this signal are not emptied during thermal bleaching. The residual level of the OSL signal after bleaching process, however, depends strongly on centre parameters and concentrations. The modifications of optical detection spectral window lead to significant changes of bleaching effects. The thermal bleaching influences also the optical cross section spectra obtained as a result of the OSL curve decomposition.

  11. UK fast reactor components - sodium removal decontamination and requalification

    International Nuclear Information System (INIS)

    Donaldson, D.M.; Bray, J.A.; Newson, I.H.

    1978-01-01

    Over the past two decades extensive experience on sodium removal techniques has been gained at the UKAEA's Dounreay Nuclear Establishment from both the Dounreay Fact Reactor (DFR) and the Prototype Fast Reactor (PFR). This experience has created confidence that complex components can be cleaned of sodium, maintenance or repair operations carried out, and the components successfully re-used. Part 2 of the paper, which describes recent operations associated with the PFR, demonstrates the background to these views. This past and continuing experience is being used in forming the basis of the plant to be provided for sodium removal, decontamination and requalification of components in the UK's future commercial fast reactors. Further improvements in techniques and in component designs can be expected in the course of the next few years. Consequently UK philosophy and approach with respect to maintenance and repair operations is sufficiently flexible to enable relevant improvements to be incorporated into the next scheduled fast reactor - the Commercial Demonstration Fast Reactor (CUR). This paper summarises the factors which are being taken into consideration in this continuously advancing field

  12. UK fast reactor components - sodium removal decontamination and requalification

    Energy Technology Data Exchange (ETDEWEB)

    Donaldson, D M [FRDD, UKAEA, Risley (United Kingdom); Bray, J A; Newson, I H [UKAEA, Dounreay Nuclear Power Establishment, Thurso (United Kingdom)

    1978-08-01

    Over the past two decades extensive experience on sodium removal techniques has been gained at the UKAEA's Dounreay Nuclear Establishment from both the Dounreay Fact Reactor (DFR) and the Prototype Fast Reactor (PFR). This experience has created confidence that complex components can be cleaned of sodium, maintenance or repair operations carried out, and the components successfully re-used. Part 2 of the paper, which describes recent operations associated with the PFR, demonstrates the background to these views. This past and continuing experience is being used in forming the basis of the plant to be provided for sodium removal, decontamination and requalification of components in the UK's future commercial fast reactors. Further improvements in techniques and in component designs can be expected in the course of the next few years. Consequently UK philosophy and approach with respect to maintenance and repair operations is sufficiently flexible to enable relevant improvements to be incorporated into the next scheduled fast reactor - the Commercial Demonstration Fast Reactor (CUR). This paper summarises the factors which are being taken into consideration in this continuously advancing field.

  13. Study of morphological and luminescent properties (TL and OSL) of ZnO nanocrystals synthetized by coprecipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Soares, A.F., E-mail: alvarodefarias@hotmail.com; Tatumi, S.H., E-mail: sonia.tatumi@gmail.com; Mazzo, T.M.; Rocca, R.R.; Courrol, L.C.

    2017-06-15

    In this work, ZnO nanocrystalline phosphorus were synthesized using the method of coprecipitation, subsequently different heat treatments at 900 and 1000 °C for 2 h and 1000 °C for 4 h were performed. Afterward, Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) emissions were verified after exposure to β-radiation. Photoluminescence results showed UV and VIS emissions. Morphological studies with X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) confirmed the crystallinity of the samples, with their well-shaped wurtzite hexagonal structures in nanoscale. ZnO calcinated at 900 °C – 2 h emitted a broad TL peak located between the 362–372 °C; for ZnO calcinated at 1000 °C – 2 h, two intense peaks were observed at 144 and 308 °C, this TL emission curve was investigated with more details using Computerized Glow Curve Deconvolution and six individual TL peaks were obtained, for sample irradiated with 40.6 Gy, corroborating with the T{sub m}-T{sub stop} results. A study of Minimum Detectable Dose (MDD) was made and a dose of (492±40) μGy was determined. CW-OSL and LM-OSL analysis were made for ZnO calcinated at 1000 °C – 2 h, allowed to verify the behaviour, and the curve existing components (fast and medium, depending on dose). As well as the calculation of the Minimum Detectable Dose for CW-OSL. - Highlights: •ZnO nanocrystals were successfully produced by the method of coprecipitation. •Grains sizes by Scherrer Equation were between 26.9–40.6 nm, corroborating with SEM. •Study of the TL emission: Computerized Glow Curve Deconvolution (CGCD) and Tm-Tstop. •TL emission of ZnO calcinated supplied the minimum detectable dose of (492±40) μGy. •Study of CW-OSL and LM-OSL with CGCD. MDD for CW-OSL evaluation of ZnO calcinated.

  14. BeOSL system for personal dosimetry : dosimetric characteristics and practical application; Sistema BeOSL para dosimetria personal : caracteristicas dosimetricas y la aplicacion practica

    Energy Technology Data Exchange (ETDEWEB)

    Mende, E. [Helmholtz Zentrum Munchen, German Research Center for Environmental Health, Working Group Engineering, D-85764 Neuherberg (Germany)

    2015-10-15

    Full text: BeOSL system of Dosimetric s is very easy to use, assimilate and maintain. Our dosimeter defines a milestone in the supervision of personal equivalent dose of Hp (10) and Hp (0.07) it covers the range of total energy of 16 KeV to 10 MeV. For this energy range is exceptional in its energy dependence for official personal dosimetry. The BeOSL system consists of two modules, one of them is the BeOSL reader that measures the radiation exposure using the latest technology, optically stimulated luminescence (OSL). The reading is extremely fast; it does not require consumables such as nitrogen or other. The detector material is beryllium oxide (Be O); this is an OSL material tissue equivalent and therefore is ideal for personal dosimetry. The BeOSL technology allows multiple readings of the dosimeter (re-read) to verify the dose or archive the dosimeter. One of the biggest advantages of BeOSL system is its modular concept allows the system to run as a manual solution or as a complete automated robotic system, which can be filled with up to 5,000 dosimeters as bulk cargo. (Author)

  15. Sodium components cleaning status in the Italian fast reactor program

    Energy Technology Data Exchange (ETDEWEB)

    De Luca, B [CNEN-RIT/MAT - Laboratorio Sviluppo Processi - C.S.N. Cassacia, Rome (Italy); Labanti, V [CNEN-DRV, Bologna (Italy); Mennucci, M [NIRA, Genoa (Italy)

    1978-08-01

    As a consequence of the Italian Fast Reactor Development, mainly aimed to the PEC project and to the participation in the French Superphenix project, it is of increasing importance to set up a reliable method for specific reactor components and related test loops. The first problem was the cleaning of the PEC fuelling machine. In order to perform the routine maintenance of the machine an alcohol cleaning method based on the use of 2-butoxyethanol-NN dimethylformamide mixture has been proposed.

  16. Characterization of Al{sub 2}O{sub 3}:C dosemeters for photon dosimetry using OSL technique; Caracterizacao de dosimetros de Al{sub 2}O{sub 3}:C para dosimetria de fotons utilizando a tecnica OSL

    Energy Technology Data Exchange (ETDEWEB)

    Villani, D.; Almeida, S.B.; Campos, L.L., E-mail: dvillani@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2016-07-01

    The optically stimulated dosimetry (OSL) has gained prominence in clinical and academic applications in Brazil. In this paper, we present results of the characterization OSL dosimeters Al{sub 2}O{sub 3}:C (TLD-500) manufactured by Rexon™ Components and TLD Systems in a RISØ reader, model TL/OSL-DA-20 for dosimetry of high-energy photon beams. All reader parameters, and its variations were evaluated. (author)

  17. Fast and accurate methods of independent component analysis: A survey

    Czech Academy of Sciences Publication Activity Database

    Tichavský, Petr; Koldovský, Zbyněk

    2011-01-01

    Roč. 47, č. 3 (2011), s. 426-438 ISSN 0023-5954 R&D Projects: GA MŠk 1M0572; GA ČR GA102/09/1278 Institutional research plan: CEZ:AV0Z10750506 Keywords : Blind source separation * artifact removal * electroencephalogram * audio signal processing Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.454, year: 2011 http://library.utia.cas.cz/separaty/2011/SI/tichavsky-fast and accurate methods of independent component analysis a survey.pdf

  18. Mortar and surface dating with Optically Stimulated Luminescence (OSL): Innovative techniques for the age determination of buildings

    International Nuclear Information System (INIS)

    Panzeri, L.

    2013-01-01

    In this work the results of a dating study on bricks and mortars using both Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) are shown. The samples came from the outside walls of the Certosa di Pavia, located in northern Italy and independently dated (XVII-XVIII century). TL dating, applied to bricks using the fine grain technique, allowed to determine the time of manufacture of the bricks (XII century), that resulted therefore re-used. To circumvent this problem the application of two innovative dating techniques, OSL surface dating and mortar dating, was attempted. The first was applied to the light-shielded surfaces of bricks and allowed to successfully determine the edification of the wall (XVII century). Mortar dating gave instead severe age overestimation: the results obtained on coarse grain quartz with the SAR technique both on multi-grains aliquots and with single-grain analyses were highly dispersed indicating an incomplete bleaching of the quartz grains. The shine-down curves were in fact characterized by the absence of the so-called fast component, as confirmed by Linear Modulated OSL technique.

  19. BeOSL system for personal dosimetry : dosimetric characteristics and practical application

    International Nuclear Information System (INIS)

    Mende, E.

    2015-10-01

    Full text: BeOSL system of Dosimetric s is very easy to use, assimilate and maintain. Our dosimeter defines a milestone in the supervision of personal equivalent dose of Hp (10) and Hp (0.07) it covers the range of total energy of 16 KeV to 10 MeV. For this energy range is exceptional in its energy dependence for official personal dosimetry. The BeOSL system consists of two modules, one of them is the BeOSL reader that measures the radiation exposure using the latest technology, optically stimulated luminescence (OSL). The reading is extremely fast; it does not require consumables such as nitrogen or other. The detector material is beryllium oxide (Be O); this is an OSL material tissue equivalent and therefore is ideal for personal dosimetry. The BeOSL technology allows multiple readings of the dosimeter (re-read) to verify the dose or archive the dosimeter. One of the biggest advantages of BeOSL system is its modular concept allows the system to run as a manual solution or as a complete automated robotic system, which can be filled with up to 5,000 dosimeters as bulk cargo. (Author)

  20. Firing temperature of pottery using TL and OSL techniques

    International Nuclear Information System (INIS)

    Polymeris, G.S.; Sakalis, A.; Papadopoulou, D.; Dallas, G.; Kitis, G.; Tsirliganis, N.C.

    2007-01-01

    Several methods of thermal analysis are used to determine in the laboratory the firing temperature of ancient ceramic sherds. These methods are based primarily on changes of physical characteristics occurring when clay minerals are heated. The luminescence properties of quartz grains in a ceramic matrix also undergo certain changes during firing. The possibility of measuring the sensitivity change (sensitization) of quartz in order to determine the firing temperature of archeological ceramic artifacts was investigated. The sensitivity change was studied for both the thermoluminescence (TL) and the optically stimulated luminescence (OSL) signal for a ceramic sample of known firing temperature. Various segments of the sample were annealed to a different temperature. Subsequently, the initial sensitivity, as well as the thermal and the pre-dose sensitization were measured for both TL and OSL at room temperature as a function of the annealing temperature. The obtained TL glow curves showed different shapes for annealing temperatures above the firing temperature. Thermal and pre-dose sensitizations also exhibited a similar, although less prominent, rise. The OSL signal was analyzed by integrating the raw signal over the initial second of stimulation. The initial sensitivity showed an abrupt change for annealing temperatures around the firing temperature. An alternative approach used for the analysis of the OSL signal involved a full-component resolved sensitization study. The same abrupt change for the initial sensitivity of both the first and second components was observed, as well as, a clear but not very prominent thermal sensitization trend for annealing temperatures above the firing temperature

  1. Fast grasping of unknown objects using principal component analysis

    Science.gov (United States)

    Lei, Qujiang; Chen, Guangming; Wisse, Martijn

    2017-09-01

    Fast grasping of unknown objects has crucial impact on the efficiency of robot manipulation especially subjected to unfamiliar environments. In order to accelerate grasping speed of unknown objects, principal component analysis is utilized to direct the grasping process. In particular, a single-view partial point cloud is constructed and grasp candidates are allocated along the principal axis. Force balance optimization is employed to analyze possible graspable areas. The obtained graspable area with the minimal resultant force is the best zone for the final grasping execution. It is shown that an unknown object can be more quickly grasped provided that the component analysis principle axis is determined using single-view partial point cloud. To cope with the grasp uncertainty, robot motion is assisted to obtain a new viewpoint. Virtual exploration and experimental tests are carried out to verify this fast gasping algorithm. Both simulation and experimental tests demonstrated excellent performances based on the results of grasping a series of unknown objects. To minimize the grasping uncertainty, the merits of the robot hardware with two 3D cameras can be utilized to suffice the partial point cloud. As a result of utilizing the robot hardware, the grasping reliance is highly enhanced. Therefore, this research demonstrates practical significance for increasing grasping speed and thus increasing robot efficiency under unpredictable environments.

  2. Development of an Equipment for Measuring OSL

    International Nuclear Information System (INIS)

    Chung, Ki Soo; Choe, Hong Soo

    2010-05-01

    A measurement system optically simulated luminescence (OSL) and thermoluminescence (TL) is developed. The system is composed by stimulation light part assembled by 3 ea of high brightness blue LEDs, temperature control system which can be controlled from room temperature to 300 .deg. C and filter package for separation of OSL and stimulation light with GG-420 and U-340 optical filters. The system was tested using Al 2 O 3 C OSL samples and a typical OSL curves were obtained. In addition, several OSL curves from LiAlO 2 C (a candidate of new OSLD material) were obtained and analyzed. A new algorithm for analysis of OSL curve and software (TOLAnal, Windows based) is developed and tested

  3. Integrated circuits from mobile phones as possible emergency OSL/TL dosimeters

    International Nuclear Information System (INIS)

    Sholom, S.; McKeever, S.W.S.

    2016-01-01

    In this article, optically stimulated luminescence (OSL) data are presented from integrated circuits (ICs) extracted from mobile phones. The purpose is to evaluate the potential of using OSL from components in personal electronic devices such as smart phones as a means of emergency dosimetry in the event of a large-scale radiological incident. ICs were extracted from five different makes and models of mobile phone. Sample preparation procedures are described, and OSL from the IC samples following irradiation using a 90 Sr/ 90 Y source is presented. Repeatability, sensitivity, dose responses, minimum measurable doses, stability and fading data were examined and are described. A protocol for measuring absorbed dose is presented, and it was concluded that OSL from these components is a viable method for assessing dose in the days following a radiological incident. (authors)

  4. INTEGRATED CIRCUITS FROM MOBILE PHONES AS POSSIBLE EMERGENCY OSL/TL DOSIMETERS.

    Science.gov (United States)

    Sholom, S; McKeever, S W S

    2016-09-01

    In this article, optically stimulated luminescence (OSL) data are presented from integrated circuits (ICs) extracted from mobile phones. The purpose is to evaluate the potential of using OSL from components in personal electronic devices such as smart phones as a means of emergency dosimetry in the event of a large-scale radiological incident. ICs were extracted from five different makes and models of mobile phone. Sample preparation procedures are described, and OSL from the IC samples following irradiation using a (90)Sr/(90)Y source is presented. Repeatability, sensitivity, dose responses, minimum measureable doses, stability and fading data were examined and are described. A protocol for measuring absorbed dose is presented, and it was concluded that OSL from these components is a viable method for assessing dose in the days following a radiological incident. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Sample dependent correlation between TL and LM-OSL in Al2O3:C

    International Nuclear Information System (INIS)

    Dallas, G.I.; Polymeris, G.S.; Stefanaki, E.C.; Afouxenidis, D.; Tsirliganis, N.C.; Kitis, G.

    2008-01-01

    Al 2 O 3 :C single crystals are known to exhibit different, sample dependent, glow-curve shapes. The relation between the Thermoluminescence (TL) traps and the linear modulated optically stimulation luminescence (LM-OSL) traps is of high importance. In the present work a correlation study is attempted using 23 single crystals with dimensions between 400 and 500μm. The correlation study involved two steps. In the first step, both TL glow curves and LM-OSL decay curves are deconvoluted and a one-to-one correlation between TL peaks and LM-OSL components is attempted. In the second step the TL glow-curves are corrected for thermal quenching, the corrected curves are deconvoluted and a new correlation between TL and LM-OSL individual components is performed

  6. UK fast reactor components. Sodium removal decontamination and requalification

    International Nuclear Information System (INIS)

    Donaldson, D.M.; Bray, J.A.; Newson, I.H.

    1978-01-01

    Extensive experience gained at the U.K.A.E.A. Dounreay Nuclear Power Development Establishment is being applied to form the basis of the plant to be provided for sodium removal, decontamination, and requalification of components in future commercial fast reactors. In the first part of a three part paper, the factors to be taken into account, showing the UK philosophy and approach to maintenance and repair operations are discussed. In the second part, PFR facilities for sodium removal and decontamination are described and some examples are given of cleaning components such as pumps, charge machine, cold trap baskets, and steam generator units. Similar facilities at DFR are briefly described. In the third part of the paper a short description is given of the Harwell mass transfer loop, currently used to study the deposition of activated stainless steel corrosion products. Decontamination method for pipework specimens cut from the loop are described and results of first screening tests of various chemical decontaminants are presented. (U.K.)

  7. Fast-wave heating of a two-component plasma

    International Nuclear Information System (INIS)

    Stix, T.H.

    1975-02-01

    The use of the compressional hydromagnetic mode (also called the magnetosonic or, simply, the fast wave) is examined in some detail with respect to the heating of a tritium plasma containing a few percent deuterium. Efficient absorption of wave energy by the deuteron component is found when ω = ω/sub c/ (deuterons), with Q/sub wave/ greater than or equal to 100. The dominant behavior of the high-energy deuteron distribution function is found to be f(v) approximately exp[3/2) ∫/sup v/ dv less than Δv greater than/less than(Δv/sub perpendicular to/) 2 greater than], where [Δv] is the Chandrasekhar-Spitzer drag coefficient, and [(Δv/sub perpendicular to/) 2 sigma] is the Kennel-Englemann quasilinear diffusion coefficient for wave--particle interaction at the deuteron cyclotron frequency. An analytic solution to the one-dimensional Fokker--Planck equation, with rf-induced diffusion, is developed, and using this solution together with Duane's fit to the D-T fusion cross-section, it is found that the nuclear fusion power output from an rf-produced two-component plasma can significantly exceed the incremental (radiofrequency) power input. (auth)

  8. Emergency OSL dosimetry with commonplace materials

    International Nuclear Information System (INIS)

    Sholom, S.; McKeever, S.W.S.

    2014-01-01

    Several commonplace materials were studied as possible emergency optically stimulated luminescence (OSL) dosimeters. The materials included: paper currency (banknotes) and coins of different denomination and from different countries; plastic cards of different types (credit and debit cards, driver's license cards, membership cards, etc.), parts and details of clothing and shoes as well as samples of different fabrics. The samples displayed significant variability in their OSL properties. They differed in the intensity of the initial ‘native’ signal; the bleaching time of the OSL signal; the sensitivity to light of different wavelengths; the fading rate of OSL signals, etc. Procedures of OSL analysis were proposed to account for this variety. Values of the minimum measurable dose (MMD) were below 2 Gy for most tested samples if OSL measurements were conducted within one week of exposure and the samples were kept in dark since exposure (except samples of shoes that were kept under environmental light). The OSL signals in banknotes appear to originate from compounds containing aluminum, silicon, calcium and titanium – these elements were detected using X-ray microanalysis. For coins, the source of the OSL signals is speculated to be small particles of quartz, which were detected on the coins' surfaces. The X-ray microanalysis spectra from fabrics and shoes revealed sodium, aluminum, titanium, iron and nickel as elements that appeared to be responsible for the radiation sensitivity of those samples. It was concluded that, under certain constrained circumstances, paper and metallic money, personal plastic cards, clothing and shoes could be used as emergency OSL dosimeters in triage applications. - Highlights: • Money, plastic cards, clothing and shoes were studied as emergency OSL dosimeters. • Values of the minimum measurable doses were below 2 Gy for most tested samples. • Tested materials could be used as emergency OSL dosimeters in triage applications

  9. Optical stimulated luminescence (OSL) dating

    International Nuclear Information System (INIS)

    Banerjee, D.

    1999-01-01

    Since the pioneering work by Huntley et al. (1985), optical dating is being increasingly recognised as an important technique for establishing a time frame of deposition of sediments (Aitken, 1998). Optical dating differs from thermoluminescence (TL) dating in that visible/infrared light from lasers or LEDs (light-emitting-diodes) is used as a means of stimulation, in contrast to thermal stimulation. It has several advantages over TL dating: (i) the resetting of the OSL (optically stimulated luminescence) clock is more effective than that of TL clock; for sediments transported under water or in other situations where the sediment grains have undergone inhomogeneous bleaching, this property ensures that ages based on optical dating are generally more reliable than TL ages, (ii) the optical dating technique is non-destructive, and multiple readouts of the optical signal is possible; this feature has resulted in the development of single-aliquot and single-grain protocols (Murray and Wintle, 1999; Banerjee et al. 1999), (iii) the sample is not heated as in TL; thus, spurious luminescence is avoided and there is a significant reduction in blackbody radiation. Dating of materials which change phase on heating is also practical, and finally, (iv) thermal quenching of luminescence is negligible, allowing accurate estimation of kinetic parameters using standard techniques and providing access to deep OSL traps. This characteristic may be helpful in extending the limits of optical dating beyond the last 150 ka from a global point of view

  10. Correlation of basic TL, OSL and IRSL properties of ten K-feldspar samples of various origins

    Energy Technology Data Exchange (ETDEWEB)

    Sfampa, I.K. [Aristotle University of Thessaloniki, Nuclear Physics Laboratory, 54124 Thessaloniki (Greece); Polymeris, G.S. [Institute of Nuclear Sciences, Ankara University, 06100 Besevler, Ankara (Turkey); Pagonis, V. [McDaniel College, Physics Department, Westminster, MD 21157 (United States); Theodosoglou, E. [Department of Mineralogy-Petrology-Economic Geology, School of Geology, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Tsirliganis, N.C. [Laboratory of Radiation Applications and Archaeological Dating, Department of Archaeometry and Physicochemical Measurements, ‘Athena’ R.& I.C., Kimmeria University Campus, GR67100 Xanthi (Greece); Kitis, G., E-mail: gkitis@auth.gr [Aristotle University of Thessaloniki, Nuclear Physics Laboratory, 54124 Thessaloniki (Greece)

    2015-09-15

    Highlights: • OSL and IRSL bleaching behavior of ten K-feldspar samples is presented. • OSL and IRSL decay curves were component resolved using tunneling model. • The growth of integrated OSL and IRSL signals versus time was described by new expression based on tunneling model. • Correlation between TL, OSL and IRSL signals and of all properties with K-feldspar structure was discussed. - Abstract: Feldspars stand among the most widely used minerals in dosimetric methods of dating using thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Having very good dosimetric properties, they can in principle contribute to the dating of every site of archaeological and geological interest. The present work studies basic properties of ten naturally occurring K-feldspar samples belonging to three feldspar species, namely sanidine, orthoclase and microcline. The basic properties studied are (a) the influence of blue light and infrared stimulation on the thermoluminescence glow-curves, (b) the growth of OSL, IRSL, residual TL and TL-loss as a function of OSL and IRSL bleaching time and (c) the correlation between the OSL and IRSL signals and the energy levels responsible for the TL glow-curve. All experimental data were fitted using analytical expressions derived from a recently developed tunneling recombination model. The results show that the analytical expressions provide excellent fits to all experimental results, thus verifying the tunneling recombination mechanism in these materials and providing valuable information about the concentrations of luminescence centers.

  11. Pure thermal sensitisation and pre-dose effect of OSL in both unfired and annealed quartz samples

    Energy Technology Data Exchange (ETDEWEB)

    Oniya, Ebenezer O., E-mail: ebenezer.oniya@aaua.edu.ng [Physics and Electronics Department, Adekunle Ajasin University, 342111 Akungba Akoko (Nigeria); Polymeris, George S. [Institute of Nuclear Sciences, Ankara University, Beşevler 06100, Ankara (Turkey); Jibiri, Nnamdi N. [Department of Physics, University of Ibadan, Ibadan (Nigeria); Tsirliganis, Nestor C. [Department of Archaeometry and Physicochemical Measurements, R.C. ‘Athena’, P.O. Box 159, Kimmeria University Campus, 67100 Xanthi (Greece); Babalola, Israel A. [Department of Physics, University of Ibadan, Ibadan (Nigeria); Kitis, George [Nuclear Physics Laboratory, Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

    2017-06-01

    The sensitisation of quartz has attracted much attention since its thorough understanding is important in luminescence studies and dating applications. The present investigation examines the influence of pure thermal activation and predose treatments on the sensitisation of different components of linearly modulated optically stimulated luminescence (LM-OSL) measured at room temperature (RT) thereby eliminating undesired thermal quenching effects. Annealed and unfired quartz samples from Nigeria were used. The OSL measurements were carried out using an automated RISØTL/OSL reader (model-TL/OSL–DA–15). A new approach was adopted to match each of the resolved components of the RT-LM-OSL to respective thermoluminescence (TL) peaks that share the same electron trap and recombination centers. Pure thermal activation and pre-dose treatments respectively affect the sensitisation of all the components of the RT-LM-OSL in a similar manner as the one reported for the 110 °C TL peak but without thermal quenching contributions. Component C4 in annealed samples that was identified to share the same electron trap and recombination centers with the 110 °C TL peak was also proved appropriate for RT-LM-OSL, instead of the initial part of the continuous wave (CW) OSL signal, thus the methods can serve as complementary dating methods.

  12. Pure thermal sensitisation and pre-dose effect of OSL in both unfired and annealed quartz samples

    International Nuclear Information System (INIS)

    Oniya, Ebenezer O.; Polymeris, George S.; Jibiri, Nnamdi N.; Tsirliganis, Nestor C.; Babalola, Israel A.; Kitis, George

    2017-01-01

    The sensitisation of quartz has attracted much attention since its thorough understanding is important in luminescence studies and dating applications. The present investigation examines the influence of pure thermal activation and predose treatments on the sensitisation of different components of linearly modulated optically stimulated luminescence (LM-OSL) measured at room temperature (RT) thereby eliminating undesired thermal quenching effects. Annealed and unfired quartz samples from Nigeria were used. The OSL measurements were carried out using an automated RISØTL/OSL reader (model-TL/OSL–DA–15). A new approach was adopted to match each of the resolved components of the RT-LM-OSL to respective thermoluminescence (TL) peaks that share the same electron trap and recombination centers. Pure thermal activation and pre-dose treatments respectively affect the sensitisation of all the components of the RT-LM-OSL in a similar manner as the one reported for the 110 °C TL peak but without thermal quenching contributions. Component C4 in annealed samples that was identified to share the same electron trap and recombination centers with the 110 °C TL peak was also proved appropriate for RT-LM-OSL, instead of the initial part of the continuous wave (CW) OSL signal, thus the methods can serve as complementary dating methods.

  13. Simulations of fast component and slow component of SMBI on HL-2A tokamak

    International Nuclear Information System (INIS)

    Shi Yong-Fu; Wang Zhan-Hui; Sun Ai-Ping; Yu De-Liang; Xu Min; Ren Qi-Long; Guo Wen-Feng

    2017-01-01

    It is very important to improve the penetration depth and fueling efficiency of supersonic molecular beam injection (SMBI) especially for the next generation fusion devices such as ITER. Two components, a fast component (FC) and a slow component (SC), have been observed in the HL-2A SMBI experiments for several years, and the FC can penetrate much more deeply than the common SMBIs which draws a great deal of attention for a better fueling method. It is the first time to the FC and SC of SMBI have been simulated and interpreted in theory and simulation in this paper with the trans-neut module of the BOUT++ code. The simulation results of the FC and SC are clear and distinguishable in the same way as the observation in experiment. For the major mechanism of the FC and SC, it is found that although the difference in the injection velocity has some effect on the penetration depth difference between the FC and SC, it is mainly caused by the self-blocking effect of the first ionized SMB. We also discuss the influence of the initial plasma density on the FC and SC, and the variation of the SC penetration depth with its injection velocity. (paper)

  14. LM-OSL from single grains of quartz: A preliminary study

    DEFF Research Database (Denmark)

    Bulur, E.; Duller, G.A.T.; Solongo, S.

    2002-01-01

    the easy-to-bleach component, those with only the hard-to-bleach component, and those exhibiting all components. The results of this preliminary study show that LM-OSL experiments carried out at the single grain level may give important insights into the luminescence properties observed when viewing...

  15. TL and OSL studies of carbon doped magnesium aluminate (MgAl2O4:C)

    Science.gov (United States)

    Raj, Sanu S.; Mishra, D. R.; Soni, Anuj; Grover, V.; Polymeris, G. S.; Muthe, K. P.; Jha, S. K.; Tyagi, A. K.

    2016-10-01

    The MgAl2O4:C has been synthesized by using two different methods by electron gun and vacuum assisted melting of MgAl2O4 in presence of graphite. The MgAl2O4:C phosphor thus developed by these two different methods have similar types of the TL/OSL defects with multiple overlapping TL glow peaks from 100 °C to 400 °C. The Computerized Curve De-convolution Analysis (CCDA) has been used to measure TL parameters such as thermal trap depth, frequency factor and order of kinetic associated with charge transfer process in TL phenomenon. The investigated TL/OSL results show that these two methods of incorporating carbon in MgAl2O4 have generated closely resemble the defects of similar types in MgAl2O4:C lattice. However, the MgAl2O4:C synthesized by electron gun shows relatively larger concentration of the TL/OSL defects as compared to MgAl2O4:C synthesized using vacuum assisted melting method. The photo-ionization cross-section (PIC) associated with fastest OSL component of MgAl2O4: C is found to be ∼ 0.5 times than that of fastest OSL component of commercially available dosimetric grade α-Al2O3:C. The MgAl2O4:C thus developed shows good dynamic OSL dose linearity from few mGy to 1 Gy. This work reveals that MgAl2O4:C could be developed as potential tissue equivalent OSL / TL material.

  16. Correlation between TL and OSL properties of CaF2:N

    International Nuclear Information System (INIS)

    Polymeris, George S.; Kitis, George; Tsirliganis, Nestor C.

    2006-01-01

    Natural CaF 2 is very well known thermoluminescent (TL) material, since it has been extensively used as a dosimeter. Its basic advantage is the exhibited high TL sensitivity. In the present work, the optically stimulated luminescence (OSL) sensitivity of this material was studied by exposing it to environmental radiation for time intervals of few hours up to a few days, and was found to be very high. By analyzing the TL glow curves and the OSL decay curves into their individual glow-peaks and components respectively, a relation between specific glow-peaks and OSL components was established. An intense thermal transfer effect occurring during optical stimulation at high temperature was observed and an explanation is offered according to existing models

  17. Fast principal component analysis for stacking seismic data

    Science.gov (United States)

    Wu, Juan; Bai, Min

    2018-04-01

    Stacking seismic data plays an indispensable role in many steps of the seismic data processing and imaging workflow. Optimal stacking of seismic data can help mitigate seismic noise and enhance the principal components to a great extent. Traditional average-based seismic stacking methods cannot obtain optimal performance when the ambient noise is extremely strong. We propose a principal component analysis (PCA) algorithm for stacking seismic data without being sensitive to noise level. Considering the computational bottleneck of the classic PCA algorithm in processing massive seismic data, we propose an efficient PCA algorithm to make the proposed method readily applicable for industrial applications. Two numerically designed examples and one real seismic data are used to demonstrate the performance of the presented method.

  18. Fast Component Pursuit for Large-Scale Inverse Covariance Estimation.

    Science.gov (United States)

    Han, Lei; Zhang, Yu; Zhang, Tong

    2016-08-01

    The maximum likelihood estimation (MLE) for the Gaussian graphical model, which is also known as the inverse covariance estimation problem, has gained increasing interest recently. Most existing works assume that inverse covariance estimators contain sparse structure and then construct models with the ℓ 1 regularization. In this paper, different from existing works, we study the inverse covariance estimation problem from another perspective by efficiently modeling the low-rank structure in the inverse covariance, which is assumed to be a combination of a low-rank part and a diagonal matrix. One motivation for this assumption is that the low-rank structure is common in many applications including the climate and financial analysis, and another one is that such assumption can reduce the computational complexity when computing its inverse. Specifically, we propose an efficient COmponent Pursuit (COP) method to obtain the low-rank part, where each component can be sparse. For optimization, the COP method greedily learns a rank-one component in each iteration by maximizing the log-likelihood. Moreover, the COP algorithm enjoys several appealing properties including the existence of an efficient solution in each iteration and the theoretical guarantee on the convergence of this greedy approach. Experiments on large-scale synthetic and real-world datasets including thousands of millions variables show that the COP method is faster than the state-of-the-art techniques for the inverse covariance estimation problem when achieving comparable log-likelihood on test data.

  19. SU-E-T-75: Commissioning Optically Stimulated Luminescence Dosimeters for Fast Neutron Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Young, L [UniversityWashington, Seattle, WA (United States); Yang, F; Sandison, G [University of Washington, Seattle, WA (United States); Woodworth, D [University of California, Santa Barbara, Santa Barbara, CA (United States); McCormick, Z [University of Nevada - Reno, Reno, Nevada (United States)

    2014-06-01

    Purpose: Fast neutrons therapy used at the University of Washington is clinically proven to be more effective than photon therapy in treating salivary gland and other cancers. A nanodot optically stimulated luminescence (OSL) system was chosen to be commissioned for patient in vivo dosimetry for neutron therapy. The OSL-based radiation detectors are not susceptible to radiation damage caused by neutrons compared to diodes or MOSFET systems. Methods: An In-Light microStar OSL system was commissioned for in vivo use by radiating Landauer nanodots with neutrons generated from 50.0 MeV protons accelerated onto a beryllium target. The OSLs were calibrated the depth of maximum dose in solid water localized to 150 cm SAD isocenter in a 10.3 cm square field. Linearity was tested over a typical clinical dose fractionation range i.e. 0 to 150 neutron-cGy. Correction factors for transient signal fading, trap depletion, gantry angle, field size, and wedge factor dependencies were also evaluated. The OSLs were photo-bleached between radiations using a tungsten-halogen lamp. Results: Landauer sensitivity factors published for each nanodot are valid for measuring photon and electron doses but do not apply for neutron irradiation. Individually calculated nanodot calibration factors exhibited a 2–5% improvement over calibration factors computed by the microStar InLight software. Transient fading effects had a significant impact on neutron dose reading accuracy compared to photon and electron in vivo dosimetry. Greater accuracy can be achieved by calibrating and reading each dosimeter within 1–2 hours after irradiation. No additional OSL correction factors were needed for field size, gantry angle, or wedge factors in solid water phantom measurements. Conclusion: OSL detectors are a useful for neutron beam in vivo dosimetry verification. Dosimetric accuracy comparable to conventional diode systems can be achieved. Accounting for transient fading effects during the neutron beam

  20. Proceedings of the international conference on irradiation behaviour of metallic materials for fast reactor core components

    International Nuclear Information System (INIS)

    Poirier, J.; Dupouy, J.M.

    Radiation effects on metals or alloys used in fast reactor core components are examined in the papers presented at this conference, the accent being put on swelling and irradiation creep of steels and nickel alloys

  1. A simple transformation for converting CW-OSL curves to LM-OSL curves

    DEFF Research Database (Denmark)

    Bulur, E.

    2000-01-01

    A simple mathematical transformation is introduced to convert from OSL decay curves obtained in the conventional way to those obtained using a linear modulation technique based on a linear increase of the stimulation light intensity during OSL measurement. The validity of the transformation...... was tested by the IR-stimulated luminescence curves from feldspars, recorded using both the conventional and the linear modulation techniques. The transformation was further applied to green-light-stimulated OSL from K and Na feldspars. (C) 2000 Elsevier Science Ltd. All rights reserved....

  2. Influence of thermal treatment on OSL regeneration in potassium chloride

    International Nuclear Information System (INIS)

    Majgier, Renata; Biernacka, Magdalena; Mandowski, Arkadiusz

    2016-01-01

    Optically stimulated luminescence (OSL) of pure analytical potassium chloride (KCl) prepared in two different forms (crystals and pellets) was studied. The occurrence of regeneration effect (self-renewal of the OSL signal) in the material was examined. The experiments using the variable delay OSL (VD-OSL) method were carried out. Performed measurements allowed to determine time scale of the phenomenon, as well as quantitative changes of regeneration depending on thermal treatment before and after irradiation. Significant increase of the OSL regeneration was noticeable for pellets after the application of the annealing before irradiation, while for crystals a substantial decrease of regeneration was observed. Preheating applied after irradiation caused that self-renewal of OSL signal was drastically reduced or completely suppressed depending on the form of KCl samples. - Highlights: • Optically stimulated luminescence (OSL) of potassium chloride (KCl) was studied. • The measurements were performed using the variable delay OSL method (VD-OSL). • It was found that regeneration of OSL intensity in KCl could be as high as 2000%. • Annealing caused reduction of OSL renewal for crystals and its increase for pellets. • Preheating after irradiation removed or significantly reduced the OSL regeneration.

  3. Fast Flux Test Facility (FFTF) feedback reactivity components

    International Nuclear Information System (INIS)

    Nguyen, D.H.

    1988-04-01

    The static tests conducted during Cycle 8A (1986) of the FFTF have allowed, for the first time, the experimental determination of each of the feedback reactivities caused by the following mechanisms: fuel axial expansion, control rod repositioning, core radial expansion, and subassembly bowing. A semiempirical equation was obtained to describe each of these feedback components that depended only on the relevant reactor temperature (bowing was presented in a tabular form). The Doppler and sodium density reactivities were calculated using existing mechanistic methods. Although they could also be fitted with closed-form equations depending only on temperatures, these equations are not needed in transient analyses using whole core safety computer codes, which use mechanistic methods. The static feedback reactivity model was extended to obtain a dynamic model via the concept of ''time constants.'' Besides being used for transient analyses in the FFTF, these feedback equations constitute a database for the validation and/or calibration of mechanistic feedback reactivity models. 2 refs., 6 tabs

  4. An environmental BeO-OSL dosimeter for emergency response

    International Nuclear Information System (INIS)

    Woda, Clemens; Kaiser, Jan Christian; Urso, Laura; Greiter, Matthias

    2012-01-01

    A conceptual design is presented to use measurements of localized absorbed dose in inner cities for production of high resolution maps of the radioactive contamination following a nuclear emergency or radiological attack. The doses are derived from luminescent detectors pre-fixed at places of high importance (e.g. public squares). For such an environmental dosimeter, BeO is used, which can be read out using optically stimulated luminescence (OSL). A suitable casing of black Perspex has been developed to give a sufficiently accurate estimate of the air kerma value at the detector position. The dosimeter is characterized according to light tightness, dose response and angular photon energy dependence. A short overview of the approach for map production is also given. - Highlights: ► An inexpensive, environmentally stable BeO based OSL dosimeter has been developed for emergency response. ► The detector enables fast readouts and shows highly favorable dosimetric properties. ► A conceptual design is described to produce maps of radioactive contamination from localized dose measurements in urban areas.

  5. OSL signal of IC chips from mobile phones for dose assessment in accidental dosimetry

    International Nuclear Information System (INIS)

    Mrozik, A.; Marczewska, B.; Bilski, P.; Książek, M.

    2017-01-01

    The rapid assessment of the radiation dose is very important for the prediction of biological effects after unintended exposition. The materials for use as dosimeters in accidental dosimetry should be everyday objects which are usually placed near the human body, for example mobile phones. IC (Integrated Circuit) chip is one of several electronic components of mobile phones which give a luminescent signal. The measurements of samples from different mobile phones and smartphones were conducted by optically stimulated luminescence (OSL) and thermoluminescence (TL) methods. The OSL measurement was performed in two ways: with readouts at room temperature and at 100 °C. This work is focused on determination of OSL dose response of IC chips, minimum detectable dose (MDD), OSL signal stability in the time after the exposition, its repeatability and sensitivity to light. Several tests of the assessment of unknown doses were also conducted. The readouts at 100 °C indicate the reducing of the fading of OSL signal in the first hours after irradiation in comparison with room temperature readouts. The obtained results showed relatively good dosimetric properties of IC chips: their high sensitivity to the ionizing radiation, linear dose response up to 10 Gy and a good reproducibility of OSL signal which can allow the dose recovery of doses less than 2 Gy in 14 days after an incident with the accuracy better than 25%. The fading is a drawback of IC chips and the fading factor should be considered when calculating the dose. - Highlights: • IC chips from smartphones demonstrated high potential for accidental dosimetry. • Minimum detectable dose was estimated as a value of 50 mGy. • Samples showed linear dose response for the dose range from 0.05 Gy up to 10 Gy.

  6. Natural and laboratory TT-OSL dose response curves: Testing the lifetime of the TT-OSL signal in nature

    International Nuclear Information System (INIS)

    Chapot, M.S.; Roberts, H.M.; Duller, G.A.T.; Lai, Z.P.

    2016-01-01

    This study compares natural and laboratory generated thermally transferred optically stimulated luminescence (TT-OSL) dose response curves (DRCs) for fine-grain quartz extracts from the Luochuan loess section in central China. Both DRCs saturate at high doses relative to the quartz OSL signal; the natural TT-OSL DRC saturates at about 2200 Gy and laboratory DRCs saturate at about 2700 Gy. However, the natural and laboratory TT-OSL DRCs deviate from one another at circa 150 Gy resulting in TT-OSL equivalent dose underestimation relative to palaeodoses expected from dose rates and independent age control. The lifetime of the TT-OSL signal at 10 °C, calculated from values of trap parameters E and s, is compared against the value for lifetime of the TT-OSL signal in nature at average burial temperature as determined from the age underestimation caused by deviation of the natural and laboratory generated DRCs. These two independent assessments of TT-OSL signal lifetime at Luochuan give similar values, suggesting that laboratory measurements of thermal stability reflect natural burial lifetimes and can potentially be used to correct TT-OSL ages for the difference between natural and laboratory dose response curves. - Highlights: • Natural and laboratory TT-OSL DRCs deviate at ∼150 Gy but saturate at higher doses. • TT-OSL signal lifetime at 10 °C calculated from measured E and s values is ∼180 ka. • TT-OSL signal lifetime at Luochuan estimated from the DRCs' deviation is ∼175 ka. • Natural and laboratory TT-OSL DRC deviation may be caused by low thermal stability. • Laboratory measurements of signal lifetime may be able to correct old TT-OSL ages.

  7. The TL and room temperature OSL properties of the glow peak at 110 deg. C in natural milky quartz: A case study

    International Nuclear Information System (INIS)

    Polymeris, George S.; Afouxenidis, Dimitrios; Tsirliganis, Nestor C.; Kitis, George

    2009-01-01

    The LM-OSL signal of quartz, while measured at room temperature, is dominated by an intermediate, broad and intense OSL component, so that its contribution and general characteristics are derived very accurately. Through a series of dose-response, bleaching and thermal decay at room temperature experiments, in conjunction with curve fitting studies, a component resolved analysis is carried out studying the correlation between this specific component, termed as LM-OSL component C 2 and the 110 deg. C TL glow peak in quartz. The dose-response of these two luminescence components behaves exactly similar being linear at low doses and saturating at almost 100 Gy. Both signals decay exponentially under illumination, providing identical optical detrapping cross-section values. Residual of both luminescence signals after thermal decay at room temperature follows an exponential law, yielding similar mean half-lives. All previous luminescence features provide strong evidence for the electron trap being the same for both the 110 deg. C TL trap and the LM-OSL component C 2 . The results of the present work are very promising and clearly support the possibility of extrapolating the TL pre-dose methodology to the OSL pre-dose effect using only the LM-OSL component C 2

  8. Tl and OSL on diopside crystal

    International Nuclear Information System (INIS)

    Cano, N.F.; Watanabe, S.; Mittani, J.C.R.; Yukihara, E.G.

    2006-01-01

    The diopside with chemical composition CaMgSi 2 O 6 is part of an important solid solution series of the pyroxene group. The mineral is commonly found in meteorites and it is an important rock forming mineral of medium and high grade metamorphic rocks which are rich in calcium. In the bibliography it is possible to found several studies on electron spin resonance (ESR), reflectance, etc. but not on thermoluminescence (TL) or optically stimulated luminescence (OSL). In the present work we studied diopside TL and OSL behaviour on natural and natural irradiated samples. The sample used in our study is a white coloured diopside provided by Mineracao Sao Judas located in Sao Paulo, Brazil. The X-Ray Fluorescence technique has shown high concentrations of SiO 2 (55.81 % mol), CaO (23.47 % mol), MgO (18.03 % mol), Al 2 O 3 (1.56 % mol), Fe 2 O 3 (0.53 % mol), K 2 O (0.44 % mol), TiO 2 (0.065 % mol), P 2 O 5 (0.026 % mol), and MnO (0.013 % mol). TL measurements on natural samples show four TL peaks at 160, 260, 360, and 450 C. After beta-irradiation an increment mainly in the low temperature peaks is observed. As for OSL measurements, low OSL signal was observed on natural samples using blue light stimulation and UV detection. The intensity of the signal was observed to increase with the irradiation dose. (Author)

  9. Blind Extraction of Chaotic Signals by Using the Fast Independent Component Analysis Algorithm

    International Nuclear Information System (INIS)

    Hong-Bin, Chen; Jiu-Chao, Feng; Yong, Fang

    2008-01-01

    We report the results of using the fast independent component analysis (FastICA) algorithm to realize blind extraction of chaotic signals. Two cases are taken into consideration: namely, the mixture is noiseless or contaminated by noise. Pre-whitening is employed to reduce the effect of noise before using the FastICA algorithm. The correlation coefficient criterion is adopted to evaluate the performance, and the success rate is defined as a new criterion to indicate the performance with respect to noise or different mixing matrices. Simulation results show that the FastICA algorithm can extract the chaotic signals effectively. The impact of noise, the length of a signal frame, the number of sources and the number of observed mixtures on the performance is investigated in detail. It is also shown that regarding a noise as an independent source is not always correct

  10. Arbitrary amplitude fast electron-acoustic solitons in three-electron component space plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Mbuli, L. N.; Maharaj, S. K. [South African National Space Agency (SANSA) Space Science, P.O. Box 32, Hermanus 7200, Republic of South Africa (South Africa); Department of Physics, University of the Western Cape (UWC), Robert Sobukwe Road, Bellville 7535, Republic of South Africa (South Africa); Bharuthram, R. [Department of Physics, University of the Western Cape (UWC), Robert Sobukwe Road, Bellville 7535, Republic of South Africa (South Africa); Singh, S. V.; Lakhina, G. S. [Indian Institute of Geomagnetism, New Panvel (West), Navi Mumbai 410218 (India); Department of Physics, University of the Western Cape (UWC), Robert Sobukwe Road, Bellville 7535, Republic of South Africa (South Africa)

    2016-06-15

    We examine the characteristics of fast electron-acoustic solitons in a four-component unmagnetised plasma model consisting of cool, warm, and hot electrons, and cool ions. We retain the inertia and pressure for all the plasma species by assuming adiabatic fluid behaviour for all the species. By using the Sagdeev pseudo-potential technique, the allowable Mach number ranges for fast electron-acoustic solitary waves are explored and discussed. It is found that the cool and warm electron number densities determine the polarity switch of the fast electron-acoustic solitons which are limited by either the occurrence of fast electron-acoustic double layers or warm and hot electron number density becoming unreal. For the first time in the study of solitons, we report on the coexistence of fast electron-acoustic solitons, in addition to the regular fast electron-acoustic solitons and double layers in our multi-species plasma model. Our results are applied to the generation of broadband electrostatic noise in the dayside auroral region.

  11. Development of guidelines for inelastic analysis in design of fast reactor components

    International Nuclear Information System (INIS)

    Nakamura, Kyotada; Kasahara, Naoto; Morishita, Masaki; Shibamoto, Hiroshi; Inoue, Kazuhiko; Nakayama, Yasunari

    2008-01-01

    The interim guidelines for the application of inelastic analysis to design of fast reactor components were developed. These guidelines are referred from 'Elevated Temperature Structural Design Guide for Commercialized Fast Reactor (FDS)'. The basic policies of the guidelines are more rational predictions compared with elastic analysis approach and a guarantee of conservative results for design conditions. The guidelines recommend two kinds of constitutive equations to estimate strains conservatively. They also provide the methods for modeling load histories and estimating fatigue and creep damage based on the results of inelastic analysis. The guidelines were applied to typical design examples and their results were summarized as exemplars to support users

  12. Dosimetry in the multi kilo-Gray range using optically-stimulated luminescence (OSL) and thermally-transferred OSL from quartz

    International Nuclear Information System (INIS)

    Burbidge, C.I.; Cabo Verde, S.I.; Fernandes, A.C.; Prudencio, M.I.; Botelho, M.L.; Dias, M.I.; Cardoso, G.

    2011-01-01

    This study explores the potential for using photon-stimulated luminescence of quartz grains to retrospectively evaluate multi-kGy gamma radiation doses. Subsamples from two ceramic tiles were given 60 Co gamma doses of 1, 3, 5, 15 and 30 kGy (nominal), accompanied by PMMA dosimeters and quartz grains from a geological sample known to exhibit thermally-transferred optically-stimulated luminescence (TTOSL). Following gamma irradiation, quartz grains were prepared from each subsample. OSL and TTOSL signals were measured for different preheat temperatures, and following re-irradiation with beta doses designed to equal the nominal gamma doses. OSL responses to 10 Gy beta test doses were measured following each cycle of high dose irradiation. Gamma doses were predicted from the beta responses, to evaluate the effectiveness of retrospective dose evaluation for different signal integrals, preheat combinations, and dose intervals. The use of linear modulation limited maximum OSL signal levels to 1.5 x 10 6 cps without reducing detector sensitivity, for the measurement of smaller TTOSL signals. The dosimetric behaviour of the three samples differed significantly: the best results were obtained from the pre-prepared geological quartz. OSL signals evident at short stimulation times, which are conventionally used for dosimetry and dating, did not in general appear appropriate for dosimetry in the range of doses examined. They exhibited dose response characteristics that were highly preheat dependant and variable in form between samples, which contained rapidly saturating and/or non-monotonic components. Higher preheats, up to 300 o C, preferentially removed OSL and TTOSL signals evident at longer stimulation times: those that remained yielded growth in signal with dose to approximately 10 kGy, but the accuracy of retrospective dose determinations was variable. TTOSL signals evident at short stimulation times increased proportionally with dose when 300 o C preheats were used, up

  13. Selection of hardfacing material for components of the Indian Prototype Fast Breeder Reactor

    International Nuclear Information System (INIS)

    Bhaduri, A.K.; Indira, R.; Albert, S.K.; Rao, B.P.S.; Jain, S.C.; Asokkumar, S.

    2004-01-01

    Nickel-base hardfacing alloys have been chosen to replace cobalt-base alloys as hardfacing material for components of the Indian Prototype Fast Breeder Reactor, for minimising the dose rate to personnel during maintenance and decommissioning, and to reduce the shielding thickness required for component handling. Induced activity, dose rate and shielding computations showed that replacing cobalt-base alloys with nickel-base alloys for hardfacing of components would result in a marked reduction in both the dose rate from the components and the thickness of lead handling flasks. Long-term ageing studies on the nickel-base hardface deposits on austenitic stainless steel showed that the hardface deposit would retain adequate hardness at the end of the components' design service-life of 40 years of exposure at 823 K

  14. TL and OSL studies on undoped diamond films grown by hot filament chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Soni, Anuj, E-mail: anujsoni.phy@gmail.com [Radiological Physics and Advisory Division, Bhabha Atomic Research Center, Mumbai 400 085 (India); Choudhary, R.K. [Materials Processing Division, Bhabha Atomic Research Center, Mumbai 400 085 (India); Polymeris, G.S. [Ankara University, Institute of Nuclear Sciences (Turkey); Mishra, D.R. [Radiological Physics and Advisory Division, Bhabha Atomic Research Center, Mumbai 400 085 (India); Mishra, P. [Materials Processing Division, Bhabha Atomic Research Center, Mumbai 400 085 (India); Kulkarni, M.S. [Radiation Safety Systems Division, Bhabha Atomic Research Center, Mumbai 400 085 (India)

    2016-09-15

    In this work, approximately 0.5 µm thick diamond films were grown on a silicon substrate by hot filament chemical vapour deposition (HFCVD) method in a gas mixture of hydrogen and methane. The batch to batch reproducibility of the sample using this technique was found to be very good. The obtained film was characterized by micro laser Raman spectroscopy (MLRS), grazing incidence X-ray diffractometry (GIXRD), scanning electron microscopy (SEM) and atomic force miscroscopy (AFM) techniques. MLRS and GIXRD results confirmed the formation of diamond whereas SEM and AFM analyses indicated uniform morphology of the film with an average grain size of 200 nm. The deposited film was studied for ionizing radiation dosimetry applications using the thermoluminescence (TL) and optically stimulated luminescence (OSL) techniques after irradiating the film by a calibrated 5 mCi, {sup 90}Sr/{sup 90}Y beta source. In the TL measurement, for a heating rate of 4 K/s, broad glow curve was obtained which was deconvoluted into seven TL peaks. The integrated TL counts were found to vary linearly with increasing the radiation dose up to 10 kGy. The characteristic TL output seen in the temperature range 200–300 °C, may be considered good for thermal stability of the film and it could also avoid TL fading during storage and non-interference of any black body radiation during the measurement. However, in comparison to TL output, the OSL response for 470 nm LED stimulation was found to be lesser. The CW–OSL decay curve has shown two components contributing to the OSL signal, having photoionization cross-section 1.5×10{sup −18} and 5.2×10{sup −19} cm{sup 2} respectively. The studies have revealed the possibility of using diamond film for high dose radiation dosimetry with TL/OSL method.

  15. Development of components for the gas-cooled fast breeder reactor program

    International Nuclear Information System (INIS)

    Dee, J.B.; Macken, T.

    1977-01-01

    The gas-cooled fast breeder reactor (GCFR) component development program is based on an extension of high temperature gas-cooled reactor (HTGR) component technology; therefore, the GCFR development program is addressed primarily to components which differ in design and requirements from HTGR components. The principal differences in primary system components are due to the increase in helium coolant pressure level, which benefits system size and efficiency in the GCFR, and differences in the reactor internals and fuel handling systems due to the use of the compact metal-clad core. The purpose of this paper is to present an overview of the principal component design differences between the GCFR and HTGR and the consequent influences of these differences on GCFR component development programs. Development program plans are discussed and include those for the prestressed concrete reactor vessel (PCRV), the main helium circulator and its supporting systems, the steam generators, the reactor thermal shielding, and the fuel handling system. Facility requirements to support these development programs are also discussed. Studies to date show that GCFR component development continues to appear to be incremental in nature, and the required tests are adaptations of related HTGR test programs. (Auth.)

  16. Dose evaluation using multiple-aliquot quartz OSL: Test of methods and a new protocol for improved accuracy and precision

    DEFF Research Database (Denmark)

    Jain, M.; Bøtter-Jensen, L.; Singhvi, A.K.

    2003-01-01

    -dose-dependent sensitivity changes during the pre-heat, and fundamental variability in the shapes of quartz OSL (blue-green or blue-light stimulated luminescence) decay forms. A new protocol using a combination of 'elevated temperature IR cleaning' (ETIR) and 'component-specific dose normalisation' (CSDN) has been developed....... CSDN accounts for variability in the OSL decay forms and absorbs such sensitivity changes. A combination of ETIR and CSDN protocol increased palaeodose precision from +/-100% to +/-4% in quartz separates from the fluvially transported sands in the Thar desert. A comparison with palaeodose estimates...

  17. Cross-tail velocity component in the plasma sheet fast flows

    Directory of Open Access Journals (Sweden)

    N. P. Dmitrieva

    2008-06-01

    Full Text Available The flux transfer in the magnetotail plasma sheet is mainly provided by the tail-aligned fast plasma flows (Bursty Bulk Flows – BBFs. In this paper we study the events with a large cross-tail velocity component, including their occurrence and relationship to the standard BBFs. We found out that a significant part of large Vy events are a subgroup connected with the BBFs propagation. The maximal deviation of the velocity vector from the X direction (about 40–50 degrees, on average is observed near the BBFs' leading front in the sheath, where the fast flow interacts with surrounding plasma. The average variation of the velocity direction in the vicinity of the BBF resembles a plasma vortex. Our results support the model, in which the BBF represents a polarized, bubble-like flux tube, propagating through the plasma sheet.

  18. Prosthetic component segmentation with blur compensation: a fast method for 3D fluoroscopy.

    Science.gov (United States)

    Tarroni, Giacomo; Tersi, Luca; Corsi, Cristiana; Stagni, Rita

    2012-06-01

    A new method for prosthetic component segmentation from fluoroscopic images is presented. The hybrid approach we propose combines diffusion filtering, region growing and level-set techniques without exploiting any a priori knowledge of the analyzed geometry. The method was evaluated on a synthetic dataset including 270 images of knee and hip prosthesis merged to real fluoroscopic data simulating different conditions of blurring and illumination gradient. The performance of the method was assessed by comparing estimated contours to references using different metrics. Results showed that the segmentation procedure is fast, accurate, independent on the operator as well as on the specific geometrical characteristics of the prosthetic component, and able to compensate for amount of blurring and illumination gradient. Importantly, the method allows a strong reduction of required user interaction time when compared to traditional segmentation techniques. Its effectiveness and robustness in different image conditions, together with simplicity and fast implementation, make this prosthetic component segmentation procedure promising and suitable for multiple clinical applications including assessment of in vivo joint kinematics in a variety of cases.

  19. [Research on fast classification based on LIBS technology and principle component analyses].

    Science.gov (United States)

    Yu, Qi; Ma, Xiao-Hong; Wang, Rui; Zhao, Hua-Feng

    2014-11-01

    Laser-induced breakdown spectroscopy (LIBS) and the principle component analysis (PCA) were combined to study aluminum alloy classification in the present article. Classification experiments were done on thirteen different kinds of standard samples of aluminum alloy which belong to 4 different types, and the results suggested that the LIBS-PCA method can be used to aluminum alloy fast classification. PCA was used to analyze the spectrum data from LIBS experiments, three principle components were figured out that contribute the most, the principle component scores of the spectrums were calculated, and the scores of the spectrums data in three-dimensional coordinates were plotted. It was found that the spectrum sample points show clear convergence phenomenon according to the type of aluminum alloy they belong to. This result ensured the three principle components and the preliminary aluminum alloy type zoning. In order to verify its accuracy, 20 different aluminum alloy samples were used to do the same experiments to verify the aluminum alloy type zoning. The experimental result showed that the spectrum sample points all located in their corresponding area of the aluminum alloy type, and this proved the correctness of the earlier aluminum alloy standard sample type zoning method. Based on this, the identification of unknown type of aluminum alloy can be done. All the experimental results showed that the accuracy of principle component analyses method based on laser-induced breakdown spectroscopy is more than 97.14%, and it can classify the different type effectively. Compared to commonly used chemical methods, laser-induced breakdown spectroscopy can do the detection of the sample in situ and fast with little sample preparation, therefore, using the method of the combination of LIBS and PCA in the areas such as quality testing and on-line industrial controlling can save a lot of time and cost, and improve the efficiency of detection greatly.

  20. Obesity, metabolic syndrome, impaired fasting glucose, and microvascular dysfunction: a principal component analysis approach.

    Science.gov (United States)

    Panazzolo, Diogo G; Sicuro, Fernando L; Clapauch, Ruth; Maranhão, Priscila A; Bouskela, Eliete; Kraemer-Aguiar, Luiz G

    2012-11-13

    We aimed to evaluate the multivariate association between functional microvascular variables and clinical-laboratorial-anthropometrical measurements. Data from 189 female subjects (34.0 ± 15.5 years, 30.5 ± 7.1 kg/m2), who were non-smokers, non-regular drug users, without a history of diabetes and/or hypertension, were analyzed by principal component analysis (PCA). PCA is a classical multivariate exploratory tool because it highlights common variation between variables allowing inferences about possible biological meaning of associations between them, without pre-establishing cause-effect relationships. In total, 15 variables were used for PCA: body mass index (BMI), waist circumference, systolic and diastolic blood pressure (BP), fasting plasma glucose, levels of total cholesterol, high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), triglycerides (TG), insulin, C-reactive protein (CRP), and functional microvascular variables measured by nailfold videocapillaroscopy. Nailfold videocapillaroscopy was used for direct visualization of nutritive capillaries, assessing functional capillary density, red blood cell velocity (RBCV) at rest and peak after 1 min of arterial occlusion (RBCV(max)), and the time taken to reach RBCV(max) (TRBCV(max)). A total of 35% of subjects had metabolic syndrome, 77% were overweight/obese, and 9.5% had impaired fasting glucose. PCA was able to recognize that functional microvascular variables and clinical-laboratorial-anthropometrical measurements had a similar variation. The first five principal components explained most of the intrinsic variation of the data. For example, principal component 1 was associated with BMI, waist circumference, systolic BP, diastolic BP, insulin, TG, CRP, and TRBCV(max) varying in the same way. Principal component 1 also showed a strong association among HDL-c, RBCV, and RBCV(max), but in the opposite way. Principal component 3 was associated only with microvascular

  1. Obesity, metabolic syndrome, impaired fasting glucose, and microvascular dysfunction: a principal component analysis approach

    Directory of Open Access Journals (Sweden)

    Panazzolo Diogo G

    2012-11-01

    Full Text Available Abstract Background We aimed to evaluate the multivariate association between functional microvascular variables and clinical-laboratorial-anthropometrical measurements. Methods Data from 189 female subjects (34.0±15.5 years, 30.5±7.1 kg/m2, who were non-smokers, non-regular drug users, without a history of diabetes and/or hypertension, were analyzed by principal component analysis (PCA. PCA is a classical multivariate exploratory tool because it highlights common variation between variables allowing inferences about possible biological meaning of associations between them, without pre-establishing cause-effect relationships. In total, 15 variables were used for PCA: body mass index (BMI, waist circumference, systolic and diastolic blood pressure (BP, fasting plasma glucose, levels of total cholesterol, high-density lipoprotein cholesterol (HDL-c, low-density lipoprotein cholesterol (LDL-c, triglycerides (TG, insulin, C-reactive protein (CRP, and functional microvascular variables measured by nailfold videocapillaroscopy. Nailfold videocapillaroscopy was used for direct visualization of nutritive capillaries, assessing functional capillary density, red blood cell velocity (RBCV at rest and peak after 1 min of arterial occlusion (RBCVmax, and the time taken to reach RBCVmax (TRBCVmax. Results A total of 35% of subjects had metabolic syndrome, 77% were overweight/obese, and 9.5% had impaired fasting glucose. PCA was able to recognize that functional microvascular variables and clinical-laboratorial-anthropometrical measurements had a similar variation. The first five principal components explained most of the intrinsic variation of the data. For example, principal component 1 was associated with BMI, waist circumference, systolic BP, diastolic BP, insulin, TG, CRP, and TRBCVmax varying in the same way. Principal component 1 also showed a strong association among HDL-c, RBCV, and RBCVmax, but in the opposite way. Principal component 3 was

  2. The role of materials in the analysis of fast breeder reactor components

    International Nuclear Information System (INIS)

    Aubert, Michel; Petrequin, Pierre.

    1982-09-01

    The analysis of fast breeder reactor components involves the knowledge of certain properties of the materials used. The latter consist of the following: - a body of data required for calculations, including allowable stresses and fatigue strength, as well as the rules applicable to these data, - a number of qualitative requirements serving to guarantee that the quality of the material fully justifies the use of the previously established elements. This duality of concerns is illustrated by some recent examples which occured during the construction of the Super Phenix reactor [fr

  3. Impact of calibration errors on CMB component separation using FastICA and ILC

    Science.gov (United States)

    Dick, Jason; Remazeilles, Mathieu; Delabrouille, Jacques

    2010-01-01

    The separation of emissions from different astrophysical processes is an important step towards the understanding of observational data. This topic of component separation is of particular importance in the observation of the relic cosmic microwave background (CMB) radiation, as performed by the Wilkinson Microwave Anisotropy Probe satellite and the more recent Planck mission, launched on 2009 May 14 from Kourou and currently taking data. When performing any sort of component separation, some assumptions about the components must be used. One assumption that many techniques typically use is knowledge of the frequency scaling of one or more components. This assumption may be broken in the presence of calibration errors. Here we compare, in the context of imperfect calibration, the recovery of a clean map of emission of the CMB from observational data with two methods: FastICA (which makes no assumption of the frequency scaling of the components) and an `Internal Linear Combination' (ILC), which explicitly extracts a component with a given frequency scaling. We find that even in the presence of small calibration errors (less than 1 per cent) with a Planck-style mission, the ILC method can lead to inaccurate CMB reconstruction in the high signal-to-noise ratio regime, because of partial cancellation of the CMB emission in the recovered map. While there is no indication that the failure of the ILC will translate to other foreground cleaning or component separation techniques, we propose that all methods which assume knowledge of the frequency scaling of one or more components be careful to estimate the effects of calibration errors.

  4. Study of combinations of TL/OSL single dosimeters for mixed high/low ionization density radiation fields

    International Nuclear Information System (INIS)

    Oster, L.; Druzhyna, S.; Orion, I.; Horowitz, Y.S.

    2013-01-01

    In this paper we discuss and compare the potential application of combined OSL/TL measurements using 6 LiF:Mg,Ti (TLD-600 is enriched of isotope 6 Li which has a high cross-section for the reaction with slow neutrons) or 7 LiF:Mg,Ti ( TLD-700 is enriched of 7 Li isotope) and TLD-100 (natural isotopic composition) detectors. The OSL/TL duel readout of LiF:Mg,Ti as an ionization density discriminator avoids some of the difficulties inherent to the various types of discrimination mixed-field passive dosimeters, and in addition has several advantages. The preferential excitation of OSL compared to TL following high ionization density (HID) alpha irradiation, naturally explained via the identification of OSL with the “two-hit” F 2 or F 3 center, whereas the major component of composite TL glow peak 5 is believed to arise from a ''one-hit'' complex defect. This evidence allows near-total discrimination between HID radiation and low-ionization density (LID) radiation. Beta and alpha particle irradiations were carried out with 90 Sr/ 90 Y (∼500 keV average energy) and 241 Am sources (4.7 MeV) respectively and neutron irradiations were carried out at the PTB (Germany) (E n = 5 MeV) and RARAF (Columbia University, USA) (E n = 6 MeV) accelerator facilities. The highest values of the FOM obtained was ∼30 for neutron/gamma discrimination and ∼110 for alpha/gamma discrimination using OSL/TL – peak 5 measurements in TLD-700. -- Highlights: ► The increased response of OSL compared to TL following HID irradiation is observed. ► This evidence is explained via the identification of OSL with the ''two-hit'' F2 centers. ► The potential application of combined OSL/TL in discrimination dosimetry is discussed. ► The values of FOM were 110 for alpha/gamma and 30 for neutron/gamma discrimination

  5. Study on fast luminescence component induced by gamma-rays in Ce doped LiCaAlF6 scintillators

    International Nuclear Information System (INIS)

    Watanabe, Kenichi; Kondo, Yoshiyuki; Yamazaki, Atsushi; Uritani, Akira; Iguchi, Tetsuo; Kawaguchi, Noriaki; Fukuda, Kentaro; Ishizu, Sumito; Yanagida, Takayuki; Fujimoto, Yutaka; Yoshikawa, Akira

    2014-01-01

    We discuss the origin of the fast luminescence component induced by fast electrons generated in gamma-ray interactions in Ce doped LiCaAlF 6 scintillators. Although the slow luminescence component induced by Ce 3+ emissions depends on the Ce concentration in the LiCaAlF 6 scintillator, the fast component is independent. The fast component is suggested to be generated in the host matrix of the LiCaAlF 6 crystal. From quantitative considerations based on Frank–Tamm equation, which shows the light yield of the Cherenkov radiation, the Cherenkov radiation was determined as the origin of the fast component. We, additionally, found that the slow rise time of main Ce 3+ emissions in the Ce:LiCaAlF 6 scintillator plays an important role to perform the pulse shape discrimination. - Highlights: • The fast luminescence in Ce:LiCaAlF 6 scintillator is generated in the host matrix. • The origin of the fast luminescence is determined as the Cherenkov radiation. • The slow rise time also plays an important role to perform PSD

  6. OSL-thermochronometry using bedrock quartz: a note of caution

    DEFF Research Database (Denmark)

    Guralnik, B.; Ankjærgaard, Christina; Jain, Mayank

    2015-01-01

    Optically stimulated luminescence (OSL) thermochronometry is an emerging application, whose capability to record sub-Million-year thermal histories is of increasing interest to a growing number of subdisciplines of Quaternary research. However, several recent studies have encountered difficulties......, and may hamper successful OSL dating. Furthermore, even when the desirable signal is present, its concentration might be indistinguishable from its environmental steady-state prediction, thus preventing its conversion to a cooling or heating history. We explore the saturation properties and the thermal...

  7. Alpha efficiency under TL and OSL - A subtraction technique using OSL and TL to detect artificial irradiation

    International Nuclear Information System (INIS)

    Zink, A.J.C.; Dabis, S.; Porto, E.; Castaing, J.

    2010-01-01

    With the development of thermoluminescence (TL) and optically stimulated luminescence (OSL) to determine the authenticity of old ceramics, forgers use artificial irradiation by gamma ray to age modern productions. Besides fraudulent action, objects can be exposed to various sources of X-rays (e.g. radiography, security control at airports). For all these reasons, the determination of artificial irradiation is an important topic for dating art objects. The main technique to identify artificial irradiations is the subtraction technique. It is based on the fact that alpha efficiency varies according to the luminescence technique (fine grain, coarse grains, predose, OSL). Having observed a rather significant difference of alpha efficiency for TL and OSL, we propose a new subtraction technique using OSL and TL of fine grains.

  8. Fast neutron radiography testing for components of launch vehicles by a baby-cyclotron

    International Nuclear Information System (INIS)

    Ikeda, Y.; Ohkubo, K.; Matsumoto, G.; Nakamura, T.; Nozaki, Y.; Wakasa, S.; Toda, Y.; Kato, T.

    1990-01-01

    Recently, neutron radiography (NR) has become an important means of nondestructive testing (NDT) in Japan. Especially thermal neutron radiography testing (NRT) has been used for the NDT of various explosive devices of launch vehicles, which are developed as a H-series program by the National Space Development Agency (NASDA) of Japan. The NRT for launch vehicles has been carried out at the NR facility of a baby-cyclotron. In the NRT a conventional film method based on silver-halide emulsion has been exclusively employed to inspect various testing objects including components, and many valuable results have been obtained so far successfully. However, recently, the launch vehicles to be shot up have become much larger. With larger launch vehicles, the parts used in them have also become larger and thicker. One main disadvantage of the NRT by thermal neutrons is somewhat weak penetrability through objects because the energy is small. With the conventional thermal neutron radiography (TNR), steel objects being thicker than 40 to 50 mm are difficult to test through them because scattered neutrons obstruct real image of the object. Consequently a new method of NRT should be developed instead of TNR and applied to the new components of H-2 launch vehicles. In order to cope with the requirement, fast neutron radiography (FNR) has been studied for testing the new components of H-2, such as large separation bolts

  9. Characterization of an optically stimulated luminescence (OSL) material for thermal neutron detection: SrS:Ce,Sm,B

    International Nuclear Information System (INIS)

    Ravotti, Federico; Garcia, Pierre; Prevost, Hildegarde; Dusseau, Laurent; Lapraz, Dominique; Vaille, Jean-Roch; Benoit, David

    2008-01-01

    SrS:Ce,Sm exhibits some interesting phosphorescent and charge storage properties that are used in OSL (optically stimulated luminescence) radiation dosimetry. To enhance the thermal neutron sensitivity of this phosphor, a new material obtained by boron doping has been developed. This OSL, B material was analysed with respect to its optical and structural characteristics in order to study possible modifications induced by doping procedure. Optical study highlights a decrease in the material luminescence of about 40% with TL and OSL experiments. The emission spectrum remains the same after boron addition. This result is in agreement with the structural characterization analysis since the lattice parameters were not modified. 11B MAS NMR results indicate that boron atoms are present in the host lattice in form of BO4 groups. Consequences on dosimetry applications are discussed. The neutron response of the OSL, B irradiated in a nuclear reactor is linear up to a fluence of 5 x 1011 cm -2 and it is possible to separate the thermal neutron and gamma components. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Predicting glucose intolerance with normal fasting plasma glucose by the components of the metabolic syndrome

    International Nuclear Information System (INIS)

    Pei, D.; Lin, J.; Kuo, S.; Wu, D.; Li, J.; Hsieh, C.; Wu, C.; Hung, Y.; Kuo, K.

    2007-01-01

    Surprisingly it is estimated that about half of type 2 diabetics remain undetected. The possible causes may be partly attributable to people with normal fasting plasma glucose (FPG) but abnormal postprandial hyperglycemia. We attempted to develop an effective predictive model by using the metabolic syndrome (MeS) components as parameters to identify such persons. All participants received a standard 75 gm oral glucose tolerance test which showed that 106 had normal glucose tolerance, 61 had impaired glucose tolerance and 6 had diabetes on isolated postchallenge hyperglycemia. We tested five models which included various MeS components. Model 0: FPG; Model 1 (Clinical history model): family history (FH), FPG, age and sex; Model 2 (MeS model): Model 1 plus triglycerides, high-density lipoprotein cholesterol, body mass index, systolic blood pressure and diastolic blood pressure; Model 3: Model 2 plus fasting plasma insulin (FPI); Model 4: Model 3 plus homeostasis model assessment of insulin resistance. A receiver-operating characteristic (ROC) curve was used to determine the predictive discrimination of these models. The area under the ROC curve of the Model 0 was significantly larger than the area under the diagonal reference line. All the other 4 models had a larger area under the ROC curve than Model 0. Considering the simplicity and lower cost of Model 2, it would be the best model to use. Nevertheless, Model 3 had the largest area under the ROC curve. We demonstrated that Model 2 and 3 have a significantly better predictive discrimination to identify persons with normal FPG at high risk for glucose intolerance. (author)

  11. Developing a SAR TT-OSL protocol for volcanically-heated aeolian quartz from Datong (China)

    DEFF Research Database (Denmark)

    Liu, Jinfeng; Murray, Andrew S.; Jain, Mayank

    2012-01-01

    The thermally-transferred optically stimulated luminescence (TT-OSL) responses of chemically-purified fine-grained quartz from a lava-baked aeolian sediment from Datong (China) are presented. Our main focus is to examine the suitability of the test dose TT-OSL and OSL response to monitor sensitiv......The thermally-transferred optically stimulated luminescence (TT-OSL) responses of chemically-purified fine-grained quartz from a lava-baked aeolian sediment from Datong (China) are presented. Our main focus is to examine the suitability of the test dose TT-OSL and OSL response to monitor...

  12. Plasma facing components: a conceptual design strategy for the first wall in FAST tokamak

    Science.gov (United States)

    Labate, C.; Di Gironimo, G.; Renno, F.

    2015-09-01

    Satellite tokamaks are conceived with the main purpose of developing new or alternative ITER- and DEMO-relevant technologies, able to contribute in resolving the pending issues about plasma operation. In particular, a high criticality needs to be associated to the design of plasma facing components, i.e. first wall (FW) and divertor, due to physical, topological and thermo-structural reasons. In such a context, the design of the FW in FAST fusion plant, whose operational range is close to ITER’s one, takes place. According to the mission of experimental satellites, the FW design strategy, which is presented in this paper relies on a series of innovative design choices and proposals with a particular attention to the typical key points of plasma facing components design. Such an approach, taking into account a series of involved physical constraints and functional requirements to be fulfilled, marks a clear borderline with the FW solution adopted in ITER, in terms of basic ideas, manufacturing aspects, remote maintenance procedure, manifolds management, cooling cycle and support system configuration.

  13. A reusable OSL-film for 2D radiotherapy dosimetry

    Science.gov (United States)

    Wouter, Crijns; Dirk, Vandenbroucke; Paul, Leblans; Tom, Depuydt

    2017-11-01

    Optical stimulated luminescence (OSL) combines reusability, sub-mm resolution, and a linear dose response in a single radiation detection technology. Such a combination is currently lacking in radiotherapy dosimetry. But OSL-films have a strong energy dependent response to keV photons due to a relative high effective atomic number (Z eff). The current work studied the applicability of a 2D OSL-film with a reduced Z eff as (IMRT/VMAT) dosimeter. Based on their commercial OSL-film experience, Agfa Healthcare N.V. produced a new experimental OSL-film for RT dosimetry. This film had a lower effective atomic number compared to the films used in radiology. Typical 2D dosimeter requirements such as uniformity, dose response, signal stability with time, and angular dependence were evaluated. Additionally, the impact of a possible residual energy dependence was assessed for the infield as well as the out-of-field region of both static beams and standard intensity modulated patterns (chair and pyramid). The OSL-film’s reusable nature allowed for a film specific absolute and linear calibration including a flood-field uniformity correction. The OSL-film was scanned with a CR-15X engine based reader using a strict timing (i.e. 4 min after ‘beam on’ or as soon as possible) to account for spontaneous recombination. The OSL-film had good basic response properties: non-uniformities  ⩽2.6%, a linear dose response (0-32 Gy), a linear signal decay (0.5% min-1) over the 20 min measured, and limited angular dependence  ⩽2.6%. Due to variations of the energy spectrum, larger dose differences were noted outside the central region of the homogenous phantom and outside both static and IMRT fields. However, the OSL-film’s measured dose differences of the IMRT patterns were lower than those of Gafchromic EBT measurements ([-1.6%, 2.1%] versus [-2.9%, 3.6%]). The current OSL-film could be used as a reusable high resolution dosimeter with read-out immediately after

  14. Emergency EPR and OSL dosimetry with table vitamins and minerals.

    Science.gov (United States)

    Sholom, S; McKeever, S W S

    2016-12-01

    Several table vitamins, minerals and L-lysine amino acid have been preliminarily tested as potential emergency dosemeters using electron paramagnetic resonance (EPR) and optically stimulated luminescence (OSL) techniques. Radiation-induced EPR signals were detected in samples of vitamin B2 and L-lysine while samples of multivitamins of different brands as well as mineral Mg demonstrated prominent OSL signals after exposure to ionizing radiation doses. Basic dosimetric properties of the radiation-sensitive substances were studied, namely dose response, fading of the EPR or OSL signals and values of minimum measurable doses (MMDs). For EPR-sensitive samples, the EPR signal is converted into units of dose using a linear dose response and correcting for fading using the measured fading dependence. For OSL-sensitive materials, a multi-aliquot, enhanced-temperature protocol was developed to avoid the problem of sample sensitization and to minimize the influence of signal fading. The sample dose in this case is also evaluated using the dose response and fading curves. MMDs of the EPR-sensitive samples were below 2 Gy while those of the OSL-sensitive materials were below 500 mGy as long as the samples are analyzed within 1 week after exposure. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Desiccants for retrospective dosimetry using optically stimulated luminescence (OSL)

    International Nuclear Information System (INIS)

    Geber-Bergstrand, Therése; Bernhardsson, Christian; Christiansson, Maria; Mattsson, Sören; Rääf, Christopher L.

    2015-01-01

    Optically stimulated luminescence (OSL) was used to test different kinds of desiccants for their potential use in retrospective dosimetry. Desiccants are used for the purpose of absorbing liquids and can be found in a number of items which may be found in the immediate environment of a person, including hand bags, drug packages, and the vehicles of rescue service teams. Any material exhibiting OSL properties suitable for retrospective dosimetry is a useful addition to the existing dosimetry system available in emergency preparedness. Eleven kinds of desiccants were investigated in order to obtain an overview of the fundamental OSL properties necessary for retrospective dosimetry. Measurements were made using a Risø TL/OSL reader and irradiations were achieved with the 90 Sr/ 90 Y source incorporated in the reader. Several of the desiccants exhibited promising properties as retrospective dosemeters. Some of the materials exhibited a strong as-received signal, i.e. without any laboratory irradiation, but the origin of this signal has not yet been established. The minimum detectable dose ranged from 8 to 450 mGy for ten of the materials and for one material (consisting of natural clay) the minimum detectable dose was 1.8 Gy. - Highlights: • Desiccants can be used as fortuitous dosemeters using OSL. • The minimum detectable dose for processed desiccants range from 8 to 450 mGy. • The minimum detectable dose for natural clay was 1.8 Gy

  16. Using OSL dating to quantify rates of Earth surface processes

    Science.gov (United States)

    Rhodes, E. J.; Rittenour, T. M.

    2010-12-01

    In Optically Stimulated Luminescence (OSL), the dating signal is reset when mineral grains are exposed to light or heat, and gradually rebuilds during subsequent burial by interaction with ionising radiation. Quartz and feldspar provide useful OSL signals demonstrating rapid signal reduction in only seconds of light exposure. Age estimates ranging from under 1 year to around 200,000 years can be determined for a wide range of sedimentary contexts, including dunes, marine deposits, fluvial and glacial environments, and recent developments provide the framework for low temperature thermochronometric applications on timescales comparable with rapid climate fluctuations. In this presentation, we explore the range of applications for determining rates of Earth surface processes using OSL. We examine technical limitations, and provide a framework for overcoming current difficulties experienced in several specific regions and contexts. We will focus on OSL dating applications to glacigenic and fluvial records, along with use of the technique in tectonic and paleoseismic contexts. In many ways, these represent the most challenging environments for OSL; rapid high energy deposition is associated with incomplete signal zeroing, and the characteristics of quartz in many of these environments make it difficult to derive precise age estimates using this mineral. We will introduce innovative methods to overcome these limitations, both existing and those under development.

  17. Remote TL and OSL for asteroid and meteorite study

    International Nuclear Information System (INIS)

    Takaki, Shunji; Ikeya, Motoji; Yamanaka, Chihiro

    1997-01-01

    Thermoluminescence (TL) and optically stimulated luminescence (OSL) of the Allende meteorite have been studied using infrared CO 2 laser light as a heat source and He-Ne laser light to excite the material, respectively from a long distance. New techniques of remote TL (R-TL) and remote OSL (R-OSL) have been developed for future remote dating from a long distance in a planetary survey. The upper limits of the distance for R-TL and R-OSL were estimated using the laboratory TL signal of the meteorite peaking at 320 o C: about 400 photons s -1 for the R-TL and 60 photons s -1 for R-OSL at a distance of 1 km using a laser beam with the divergence of 0.1 mrad at powers of 100 and 1 W, respectively. An age limit of 10 5 or 10 6 years due to the signal saturation and the objects heterogeneity, as expected from previous studies, may make the asteroid survey difficult but would still help to investigate the surface activities of icy planets and satellites in outer planet worlds. (author)

  18. Reasons why Plutonium 242 is the best fission chamber deposit to monitor the fast component of a high neutron flux

    International Nuclear Information System (INIS)

    Filliatre, P.; Oriol, L.; Jammes, C.; Vermeeren, L.

    2008-01-01

    The FNDS project aims at developing fission chambers to measure on-line the fast component of a high neutron flux (∼10 14 ncm -2 s -1 or more) with a significant thermal component. We identify with simulations the deposits of fission chambers that are best suited to this goal. We address the question of the evolution of the deposit by radiative capture and decay. A deposit of 242 Pu appears as the best choice, with a high initial sensitivity to fast neutrons only slowly degrading under irradiation. The effect of unavoidable impurities was assessed: small concentrations of 241 Pu and 239 Pu can be tolerated

  19. Properties of lithium aluminate for application as an OSL dosimeter

    International Nuclear Information System (INIS)

    Twardak, A.; Bilski, P.; Marczewska, B.; Lee, J.I.; Kim, J.L.; Gieszczyk, W.; Mrozik, A.; Sądel, M.; Wróbel, D.

    2014-01-01

    Several samples of undoped and carbon or copper doped lithium aluminate (LiAlO 2 ) were prepared in an attempt to achieve a material, which can be applicable in optically stimulated luminescence (OSL) dosimetry. All investigated samples are highly sensitive to ionizing radiation and show good reproducibility. The undoped and copper doped samples exhibit sensitivity several times higher than that of Al 2 O 3 :C, while sensitivity of the carbon doped samples is lower. The studied samples exhibit significant fading, but dynamics of signal loss is different for differently doped samples, what indicates a possibility of improving this characteristic by optimizing dopant composition. - Highlights: • OSL properties of lithium aluminate for personal dosimetry. • Doping influence on OSL fading of lithium aluminate. • Application of lithium aluminate in thermal neutron measurements

  20. Creep/fatigue damage prediction of fast reactor components using shakedown methods

    International Nuclear Information System (INIS)

    Buckthorpe, D.E.

    1997-01-01

    The present status of the shakedown method is reviewed, the application of the shakedown based principles to complex hardening and creep behaviour is described and justified and the prediction of damage against design criteria outlined. Comparisons are made with full inelastic analysis solutions where these are available and against damage assessments using elastic and inelastic design code methods. Current and future developments of the method are described including a summary of the advances made in the development of the post process ADAPT, which has enabled the method to be applied to complex geometry features and loading cases. The paper includes a review of applications of the method to typical Fast Reactor structural example cases within the primary and secondary circuits. For the primary circuit this includes structures such as the large diameter internal shells which are surrounded by hot sodium and subject to slow and rapid thermal transient loadings. One specific case is the damage assessment associated with thermal stratifications within sodium and the effects of moving sodium surfaces arising from reactor trip conditions. Other structures covered are geometric features within components such as the Above Core structure and Intermediate Heat Exchanger. For the secondary circuit the method has been applied to alternative and more complex forms of geometry namely thick section tubeplates of the Steam Generator and a typical secondary circuit piping run. Both of these applications are in an early stage of development but are expected to show significant advantages with respect to creep and fatigue damage estimation compared with existing code methods. The principle application of the method to design has so far been focused on Austenitic Stainless steel components however current work shows some significant benefits may be possible from the application of the method to structures made from Ferritic steels such as Modified 9Cr 1Mo. This aspect is briefly

  1. Fast plasma sintering delivers functional graded materials components with macroporous structures and osseointegration properties.

    Science.gov (United States)

    Godoy, R F; Coathup, M J; Blunn, G W; Alves, A L; Robotti, P; Goodship, A E

    2016-04-13

    We explored the osseointegration potential of two macroporous titanium surfaces obtained using fast plasma sintering (FPS): Ti macroporous structures with 400-600 µmØ pores (TiMac400) and 850-1000 µmØ pores (TiMac850). They were compared against two surfaces currently in clinical use: Ti-Growth® and air plasma spray (Ti-Y367). Each surface was tested, once placed over a Ti-alloy and once onto a CoCr bulk substrate. Implants were placed in medial femoral condyles in 24 sheep. Samples were explanted at four and eight weeks after surgery. Push-out loads were measured using a material-testing system. Bone contact and ingrowth were assessed by histomorphometry and SEM and EDX analyses. Histology showed early osseointegration for all the surfaces tested. At 8 weeks, TiMac400, TiMac850 and Ti-Growth® showed deep bone ingrowth and extended colonisation with newly formed bone. The mechanical push-out force was equal in all tested surfaces. Plasma spray surfaces showed greater bone-implant contact and higher level of pores colonisation with new bone than FPS produced surfaces. However, the void pore area in FPS specimens was significantly higher, yet the FPS porous surfaces allowed a deeper osseointegration of bone to implant. FPS manufactured specimens showed similar osseointegration potential to the plasma spray surfaces for orthopaedic implants. FPS is a useful technology for manufacturing macroporous titanium surfaces. Furthermore, its capability to combine two implantable materials, using bulk CoCr with macroporous titanium surfaces, could be of interest as it enables designers to conceive and manufacture innovative components. FPS delivers functional graded materials components with macroporous structures optimised for osseointegration.

  2. Production of configuration tables for the Input Mezzanine and Data Formatter components in the ATLAS Fast Tracker Trigger System

    CERN Document Server

    Poudroux, Jean-Michael

    2014-01-01

    The project revolve around developing configuration tables for two components in the Fast Tracker (FTK) trigger system used in the ATLAS trigger system. These components are Input Mezzanine cards and the Data Formatter. The tables give easy access to different ID's which identify which module the data is originating from and also which tower and what detector-region the data is being processed in.

  3. Temperature dependence of OSL decay curves: Experimental and theoretical aspects

    DEFF Research Database (Denmark)

    McKeever, S.W.S.; Bøtter-Jensen, L.; Agersnap Larsen, N.

    1997-01-01

    ; (2) thermally assisted optical stimulation; (3) thermal quenching; and (4) localized donor-acceptor type recombination. Experimental OSL data from natural quartz and feldspars, stimulated with both green and infra-red light, are examined in the light of the theoretical considerations. (C) 1997...

  4. Does deposition depth control the OSL bleaching of fluvial sediment?

    NARCIS (Netherlands)

    Cunningham, A. C.; Wallinga, J.; Hobo, N.; Versendaal, A. J.; Makaske, B.; Middelkoop, H.

    2014-01-01

    The Optically Stimulated Luminescence (OSL) signal from fluvial sediment often contains a remnant from the previous deposition cycle, leading to a partially bleached equivalent-dose distribution. Although identification of the burial dose is of primary concern, the degree of bleaching could

  5. FAST

    DEFF Research Database (Denmark)

    Zuidmeer-Jongejan, Laurian; Fernandez-Rivas, Montserrat; Poulsen, Lars K.

    2012-01-01

    ABSTRACT: The FAST project (Food Allergy Specific Immunotherapy) aims at the development of safe and effective treatment of food allergies, targeting prevalent, persistent and severe allergy to fish and peach. Classical allergen-specific immunotherapy (SIT), using subcutaneous injections with aqu...

  6. Performance of OSL dosimeters in clinical beams from mammography; Desempenho de dosimetros OSL em feixes clinicos empregados na mamografia

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Caio V.; Cabete, Henrique V.; Alves, Fatima F.R.; Pires, Silvio R.; Medeiros, Regina B.; Freitas, Marcelo B. [Universidade Federal de Sao Paulo (HSP/EPM/UNIFESP), SP (Brazil). Escola Paulista de Medicina; Malthez, Anna Luiza M.C. [Universidade Estadual de Campinas (CPG/FEEC/UNICAMP), Campinas, SP (Brazil). Faculdade de Engenharia Eletrica e de Computacao. Programa de Pos-Graduacao

    2015-08-15

    The search for the relationship between dose and mammography image is critical to the quality of clinical practice. In this sense, dosimetry using optically stimulated luminescent detectors (OSLD) is configured as alternative to traditional methods and allows on-site dose checks received by patients. This study aimed to verify the performance of OSL dosimeters in clinical beams typically used in mammography. For this, aluminum oxide detectors, especially designed to reduce interference on the image quality, were exposed to radiation beam combining targets and filters of a mammography equipment with digital imaging system. In addition were also employed lithium fluoride detectors irradiated under the same conditions, together with a ionization chamber for determination of dose values. A homogeneous acrylic phantom was designed and used for simulating different breast and also determine internal dose values under the irradiation conditions. The results allowed the determination of calibration factors (OSL signal x dose) of the exposed detectors to the radiation beams typically used in clinical practice. The phantom images and the comparison between TL and OSL responses suggest the possibility of routine use of the OSL dosimetry system in mammography. (author)

  7. Reasons why Plutonium 242 is the best fission chamber deposit to monitor the fast component of a high neutron flux

    Energy Technology Data Exchange (ETDEWEB)

    Filliatre, P. [CEA, DEN, SPEx/LDCI, F-13108 Saint-Paul-lez-Durance (France); Laboratoire Commun d' Instrumentation CEA-SCK-CEN (France)], E-mail: philippe.filliatre@cea.fr; Oriol, L.; Jammes, C. [CEA, DEN, SPEx/LDCI, F-13108 Saint-Paul-lez-Durance (France); Laboratoire Commun d' Instrumentation CEA-SCK-CEN (France); Vermeeren, L. [SCK-CEN, Boeretang 200, B-2400 Mol (Belgium); Laboratoire Commun d' Instrumentation CEA-SCK-CEN (France)

    2008-08-11

    The FNDS project aims at developing fission chambers to measure on-line the fast component of a high neutron flux ({approx}10{sup 14}ncm{sup -2}s{sup -1} or more) with a significant thermal component. We identify with simulations the deposits of fission chambers that are best suited to this goal. We address the question of the evolution of the deposit by radiative capture and decay. A deposit of {sup 242}Pu appears as the best choice, with a high initial sensitivity to fast neutrons only slowly degrading under irradiation. The effect of unavoidable impurities was assessed: small concentrations of {sup 241}Pu and {sup 239}Pu can be tolerated.

  8. The orexin component of fasting triggers memory processes underlying conditioned food selection in the rat.

    Science.gov (United States)

    Ferry, Barbara; Duchamp-Viret, Patricia

    2014-03-14

    To test the selectivity of the orexin A (OXA) system in olfactory sensitivity, the present study compared the effects of fasting and of central infusion of OXA on the memory processes underlying odor-malaise association during the conditioned odor aversion (COA) paradigm. Animals implanted with a cannula in the left ventricle received ICV infusion of OXA or artificial cerebrospinal fluid (ACSF) 1 h before COA acquisition. An additional group of intact rats were food-deprived for 24 h before acquisition. Results showed that the increased olfactory sensitivity induced by fasting and by OXA infusion was accompanied by enhanced COA performance. The present results suggest that fasting-induced central OXA release influenced COA learning by increasing not only olfactory sensitivity, but also the memory processes underlying the odor-malaise association.

  9. Influence of pre-measurement thermal treatment on OSL of synthetic quartz measured at room temperature

    International Nuclear Information System (INIS)

    Kale, Y.D.; Gandhi, Y.H.

    2008-01-01

    Much effort has been made to study the influence of pre-measurement thermal treatment and ionizing radiation on quartz specimens owing to its use in a large number of applications. Optically stimulated luminescence (OSL) being a structured and sensitive phenomenon promises to correlate the responsible color center and luminescence emission. OSL studies on quartz with such conditions can reveal many significant results. The aim of the present investigation is to understand the effect of annealing temperature on OSL characteristics of synthetic quartz recorded at room temperature. At identical annealing duration and β-dose, the shape of OSL decay curve remains non-exponential; when specimens annealed at lower temperature (∼400 deg. C). The shape of decay curve changes to exponential in nature along with rise in OSL intensity when the specimen was given higher temperature of annealing (>400 deg. C). The effects of such protocol on pattern of OSL sensitivity as well as area under the OSL decay curve are also presented here. The presence of shallow traps, when OSL decay curve was recorded at room temperature seems to be responsible for the changes in OSL pattern. The influence of shallow traps is attributed to non-exponential decay of OSL recorded at room temperature

  10. A One-Component, Fast-Cure, and Economical Epoxy Resin System Suitable for Liquid Molding of Automotive Composite Parts

    Directory of Open Access Journals (Sweden)

    Yiru Wang

    2018-04-01

    Full Text Available Imidazole cured epoxy resin systems were evaluated for one-component, fast-curing resins for liquid molding of automotive composite parts according to industry requirements. It was demonstrated that an epoxy resin-1-(cyanoethyl-2-ethyl-4-methylimidazol(EP-1C2E4MIM system would cure in a few minutes at 120 °C, while exhibiting acceptable pot life, viscosity profiles, and low water absorption. Moreover, this system yielded high Tg parts with mechanical properties similar to the amine-epoxy systems, which are the mainstream two-component epoxy resin systems for automobiles.

  11. The Orexin Component of Fasting Triggers Memory Processes Underlying Conditioned Food Selection in the Rat

    Science.gov (United States)

    Ferry, Barbara; Duchamp-Viret, Patricia

    2014-01-01

    To test the selectivity of the orexin A (OXA) system in olfactory sensitivity, the present study compared the effects of fasting and of central infusion of OXA on the memory processes underlying odor-malaise association during the conditioned odor aversion (COA) paradigm. Animals implanted with a cannula in the left ventricle received ICV infusion…

  12. OSL and TL of Resistors of Mobile Phones for Retrospective Accident Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. I.; Kim, J. L.; Pradhan, A. S.; Chang, I.; Kim, B. H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    work place and in the public rather than actual health hazard due to radiation exposure. Therefore, a quick demonstration of measurement of doses following the accident is needed to reassure those receiving insignificant or low level of exposures that they are quite safe and need no treatment. This confidence building also becomes an important aspect of dosimetry. As the ranges of doses which could be encountered in such situations may vary from the background level to significantly high doses depending on the type of accident / incident and the location of personnel, it becomes important that the techniques used in retrospective dosimetry should be very sensitive and should be able to measure doses in a wide range from background level to several Gy. More recently, with the increasing apprehensions of nuclear terrorism / dirty bomb, research and developments in retrospective dosimetry has gained a new momentum the world over. Among the TL and OSL sensitive materials, the extraction and the processing of the materials from bricks and roof tiles is a very time consuming process and gives indirect estimate of individual doses. On the other hand, TL and OSL properties of components of electronic devices mobile phones, i-pods, black-berries, mp3 players and USB sticks containing ceramics with luminescence properties (e.g resistors, capacitors, resonators, antenna switches, transistors etc.) and chip cards containing silica epoxy (e.g. credit cards, bank cards, social security card, telephone card, SIM cards, ID cards e.g) are being considered very attractive and being evaluated. In this study, the TL and OSL properties of the electronic components of mobile phones are investigated and dose recovery potential is evaluated with a presumption that a mobile phone has become a part of body belongings masses of almost ages

  13. OSL and TL of Resistors of Mobile Phones for Retrospective Accident Dosimetry

    International Nuclear Information System (INIS)

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

    2012-01-01

    and in the public rather than actual health hazard due to radiation exposure. Therefore, a quick demonstration of measurement of doses following the accident is needed to reassure those receiving insignificant or low level of exposures that they are quite safe and need no treatment. This confidence building also becomes an important aspect of dosimetry. As the ranges of doses which could be encountered in such situations may vary from the background level to significantly high doses depending on the type of accident / incident and the location of personnel, it becomes important that the techniques used in retrospective dosimetry should be very sensitive and should be able to measure doses in a wide range from background level to several Gy. More recently, with the increasing apprehensions of nuclear terrorism / dirty bomb, research and developments in retrospective dosimetry has gained a new momentum the world over. Among the TL and OSL sensitive materials, the extraction and the processing of the materials from bricks and roof tiles is a very time consuming process and gives indirect estimate of individual doses. On the other hand, TL and OSL properties of components of electronic devices mobile phones, i-pods, black-berries, mp3 players and USB sticks containing ceramics with luminescence properties (e.g resistors, capacitors, resonators, antenna switches, transistors etc.) and chip cards containing silica epoxy (e.g. credit cards, bank cards, social security card, telephone card, SIM cards, ID cards e.g) are being considered very attractive and being evaluated. In this study, the TL and OSL properties of the electronic components of mobile phones are investigated and dose recovery potential is evaluated with a presumption that a mobile phone has become a part of body belongings masses of almost ages

  14. Angular dependence of the nanoDot OSL dosimeter

    OpenAIRE

    Kerns, James R.; Kry, Stephen F.; Sahoo, Narayan; Followill, David S.; Ibbott, Geoffrey S.

    2011-01-01

    Purpose: Optically stimulated luminescent detectors (OSLDs) are quickly gaining popularity as passive dosimeters, with applications in medicine for linac output calibration verification, brachytherapy source verification, treatment plan quality assurance, and clinical dose measurements. With such wide applications, these dosimeters must be characterized for numerous factors affecting their response. The most abundant commercial OSLD is the InLight∕OSL system from Landauer, Inc. The purpose of...

  15. Design basis for creep of zirconium alloy components in a fast neutron flux

    International Nuclear Information System (INIS)

    Ross-Ross, P.A.; Fidleris, V.

    1975-01-01

    The chalk River Nuclear Laboratory's experience with the creep of zirconium alloys in a neutron flux is described. Fast neutron flux changes the creep behaviour of zirconium alloys and new design criteria for in-reactor applications are needed. From experimental results empirical relations describing the effects of neutron flux, stress, temperature, time and anisotropy on creep rate were established. The relations are applied to the design of pressure tubes. (author)

  16. Research and developments on nondestructive testing in fabrications of fast breeder reactor structural components in Japan

    International Nuclear Information System (INIS)

    Ebata, M.; Ooka, K.; Miyoshi, S.; Senda, T.

    1985-01-01

    Research and developments (R and D) have been conducted on the nondestructive testing techniques necessary for the construction of fast breeder reactor (FBR). Radiographic tests have been made on tube-tube plate welds and small-diameter tube welds, etc. Ultrasonic tests have been conducted on austenitic stainless steel welds. In the penetrant tests and magnetic particle tests, the investigations have been performed on the effects of various test factors on the test results

  17. Design basis for creep of zirconium alloy components in a fast neutron flux

    International Nuclear Information System (INIS)

    Ross-Ross, P.A.; Fidleris, V.

    1974-01-01

    The Chalk River Nuclear Laboratory's experience with the creep of zirconium alloys in a neutron flux is described. Fast neutron flux changes the creep behavior of zirconium alloys and new design criteria for in-reactor applications are needed. From experimental results empirical relations describing the effects of neutron flux, stress, temperature, time, and anisotropy on creep rate were established. The relations are applied to the design of pressure tubes. (author)

  18. Gamma response characterizations of optically stimulated luminescence (OSL) affects personal dosimetry

    Science.gov (United States)

    Monthonwattana, S.; Esor, J.; Rungseesumran, T.; Intang, A.

    2017-06-01

    Optically Stimulated Luminescence (OSL) is the current technique of personal dosimetry changed by Nuclear Technology Service Center instead of Thermoluminescence dosimetry (TLD) because OSL has more advantages, such as repeat reading and elimination of heating process. In this study, OSL was used to test the gamma response characterizations. Detailed OSL investigation on personal dosimetry was carried out in the dose range of 0.2 - 3.0 mSv. The batch homogeneity was 7.66%. R2 value of the linear regression was 0.9997. The difference ratio of angular dependence at ± 60° was 8.7%. Fading of the reading was about 3%.

  19. Fast monitoring of motor exhaust components by resonant multi-photon ionisation and time-of-flight mass spectrometry

    Science.gov (United States)

    Franzen, Jochen; Frey, Rüdiger; Nagel, Holger

    1995-03-01

    A new analytical procedure is provided by the combination of two types of spectroscopy. Resonant ionization of selected compounds by multiphoton ionization is based on results of absorption spectroscopy for the compound molecules of interest and time-of-flight mass spectrometry serves for the unambigious detection of these compounds. An interesting application of this method is the fast exhaust gas analysis. In the development of future combustion engines, the management of dynamic motor processes becomes predominant because by more than 90 % of all the dangerous exhaust pollutions are produced in instationary motor phases such as fast speed or load changes. The investigation of dynamic processes however, requires fast analytical procedures with millisecond time resolution together with the capability to measure individual components in a very complex gas mixture The objectives for a development project of such an instrument were set by the Research Association for Combustion Engines (Forschungsvereinigung Verbrennungskraftmaschinen, FVV, Germany): Up to ten substances should be monitored synchroneously with a time resolution of about 10 milliseconds, with concentration limits of 1 part per million and with a precision better than 10 % relative standard deviation. Such a laser mass spectrometer for fast multi-component automotive exhaust analyses has been developed in a joint research project by Bruker-Franzen Analytik GmbH, Dornier GmbH and the Technical University of Munich. The system has been applied at a motor test facility to investigate the emissions of the aromatic hydrocarbons benzene, toluene and xylene, of nitric oxide and acetaldehyde in stationary and dynamic engine operation. These measurements demonstrate that strong emission of these pollutants takes place at instationary engine operation and in particular that these compounds are emitted at different times, giving new information about the processes in the combustion chamber and in the exhaust pipe.

  20. How to measure distinct components of visual attention fast and reliably

    DEFF Research Database (Denmark)

    Vangkilde, Signe Allerup; Kyllingsbæk, Søren; Habekost, Thomas

    2009-01-01

    Measuring different attentional processes in a fast and reliable way is important in both clinical and experimental settings. However, most tests of visual attention are either lengthy or lack sensitivity, specificity, and reliability. To address this we developed a ten minute test procedure...... for the Swedish Betula-project, a longitudinal study investigating changes in cognitive functions over the adult life span (Nilsson et al., 2004). The test consists of a computer-based letter recognition task with stimulus displays of varied durations followed by pattern masks or a blank screen. The temporal...

  1. An empirical formula for scattered neutron components in fast neutron radiography

    International Nuclear Information System (INIS)

    Dou Haifeng; Tang Bin

    2011-01-01

    Scattering neutrons are one of the key factors that may affect the images of fast neutron radiography. In this paper, a mathematical model for scattered neutrons is developed on a cylinder sample, and an empirical formula for scattered neutrons is obtained. According to the results given by Monte Carlo methods, the parameters in the empirical formula are obtained with curve fitting, which confirms the logicality of the empirical formula. The curve-fitted parameters of common materials such as 6 LiD are given. (authors)

  2. Statistical properties of material strength for reliability evaluation of components of fast reactors. Austenitic stainless steels

    International Nuclear Information System (INIS)

    Takaya, Shigeru; Sasaki, Naoto; Tomobe, Masato

    2015-03-01

    Many efforts have been made to implement the System Based Code concept of which objective is to optimize margins dispersed in several codes and standards. Failure probability is expected to be a promising quantitative index for optimization of margins, and statistical information for random variables is needed to evaluate failure probability. Material strength like tensile strength is an important random variable, but the statistical information has not been provided enough yet. In this report, statistical properties of material strength such as creep rupture time, steady creep strain rate, yield stress, tensile stress, flow stress, fatigue life and cyclic stress-strain curve, were estimated for SUS304 and 316FR steel, which are typical structural materials for fast reactors. Other austenitic stainless steels like SUS316 were also used for statistical estimation of some material properties such as fatigue life. These materials are registered in the JSME code of design and construction of fast reactors, so test data used for developing the code were used as much as possible in this report. (author)

  3. The derivative assay--an analysis of two fast components of DNA rejoining kinetics

    International Nuclear Information System (INIS)

    Sandstroem, B.E.

    1989-01-01

    The DNA rejoining kinetics of human U-118 MG cells were studied after gamma-irradiation with 4 Gy. The analysis of the sealing rate of the induced DNA strand breaks was made with a modification of the DNA unwinding technique. The modification meant that rather than just monitoring the number of existing breaks at each time of analysis, the velocity, at which the rejoining process proceeded, was determined. Two apparent first-order components of single-strand break repair could be identified during the 25 min of analysis. The half-times for the two components were 1.9 and 16 min, respectively

  4. Classification of fault diagnosis in a gear wheel by used probabilistic neural network, fast Fourier transform and principal component analysis

    Directory of Open Access Journals (Sweden)

    Piotr CZECH

    2007-01-01

    Full Text Available This paper presents the results of an experimental application of artificial neural network as a classifier of the degree of cracking of a tooth root in a gear wheel. The neural classifier was based on the artificial neural network of Probabilistic Neural Network type (PNN. The input data for the classifier was in a form of matrix composedof statistical measures, obtained from fast Fourier transform (FFT and principal component analysis (PCA. The identified model of toothed gear transmission, operating in a circulating power system, served for generation of the teaching and testing set applied for the experiment.

  5. The chemistry of two-component fluoride crystalline optical media for heavy, fast, radiation hard scintillators

    International Nuclear Information System (INIS)

    Sobolev, B.P.; Krivandina, E.A.; Fedorov, P.P.; Vasilchenko, V.G.

    1994-01-01

    Prospects for preparation of two-component dense optical materials for scintillators are shown, using data on phase diagrams of about 300 MF m - RF n (m, n ≤ 4) type systems, formed by metal fluorides. Primary characteristics (decay time and light output of luminescence, radiation hardness, etc.) of some multicomponent crystals are reported

  6. High resolution OSL and post-IR IRSL dating of the last interglacialeglacial cycle at the Sanbahuo loess site (northeastern China)

    DEFF Research Database (Denmark)

    Yi, Shuangwen; Buylaert, Jan-Pieter; Murray, Andrew

    2015-01-01

    Northeastern China is located in the East Asian monsoon region; it is sensitive to both high and low latitude global climate systems. Loess deposits in the region have considerable potential as sensitive archives of past climate changes. However, research into loess deposition and climate change...... to have been a period of fast loess deposition at ~62 ka, perhaps indicative of winter monsoon intensification with a very cold and dry climate that lead to a serious desertification of dunefields in northeastern China. © 2015 Elsevier B.V. All rights reserved....... in this region is restricted by the lack of independent age control. In this study, coarse-grained quartz SAR OSL and K-feldspar post-IR infrared (IR) stimulated luminescence (post-IR IRSL; pIRIR290) methods have been used to date the Sanbahuo loess site in northeastern China. The quartz OSL characteristics...

  7. RF high voltage performance of RF transmission line components on the DIII-D Fast Wave Current Drive (FWCD) system

    International Nuclear Information System (INIS)

    Ferguson, S.W.; Callis, R.W.; Cary, W.P.; Phelps, D.A.; Ponce, D.; Baity, F.W.; Barber, G.

    1995-01-01

    The performance of the high voltage rf components of the DIII-D Fast Wave Current Drive System (FWCD) have been evaluated under various conditions of insulator configuration, insulator material, insulating gas and gas pressure. The insulator materials that have been investigated are alumina, steatite, pyrex, quartz, and teflon. The results of this evaluation are discussed in this paper. Additionally a rf high potter was developed to aid in the evaluation of rf high voltage components. The high potter consists of a 50 Ω, 1/4 wavelength cavity with a variable position short and a 50 ohm matched tap at one end of the cavity. With this configuration rf voltages were generated in excess of 100 kVp in the frequency range 30 to 60 MHz

  8. RF high voltage performance of RF transmission line components on the DIII-D Fast Wave Current Drive (FWCD) System

    International Nuclear Information System (INIS)

    Ferguson, S.W.; Callis, R.W.; Cary, W.P.; Phelps, D.A.; Ponce, D.; Baity, F.W.; Barber, G.

    1995-12-01

    The performance of the high voltage rf components of the DIII-D Fast Wave Current Drive System (FWCD) have been evaluated under various conditions of insulator configuration, insulator material, insulating gas and gas pressure. The insulator materials that have been investigated are alumina, steatite, pyrex, quartz, and teflon. The results of this evaluation are discussed in this paper. Additionally a rf high potter was developed to aid in the evaluation of rf high voltage components. The high potter consists of a 50 Ω, 1/4 wavelength cavity with a variable position short and a 50 ohm matched tap at one end of the cavity. With this configuration rf voltages were generated in excess of 100 kVp in the frequency range 30 to 60 MHz

  9. Extraction of fast neuronal changes from multichannel functional near-infrared spectroscopy signals using independent component analysis

    Science.gov (United States)

    Morren, Geert; Wolf, Martin; Lemmerling, Philippe; Wolf, Ursula; Choi, Jee H.; Gratton, Enrico; De Lathauwer, Lieven; Van Huffel, Sabine

    2002-06-01

    Fast changes in the range of milliseconds in the optical properties of cerebral tissue, which are associated with brain activity, can be detected using non-invasive near-infrared spectroscopy (NIRS). These changes in light scattering are due to an alteration in the refractive index at neuronal membranes. The aim of this study was to develop highly sensitive data analysis algorithms to detect this fast signal, which is small compared to other physiological signals. A frequency-domain tissue oximeter, whose laser diodes were modulated at 110MHz was used. The amplitude, mean intensity and phase of the modulated optical signal was measured at 96Hz sample rate. The probe consisting of 4 crossed source detector pairs was placed above the motor cortex, contralateral to the hand performing a tapping exercise consisting of alternating rest- and tapping periods of 20s each. The tapping frequency, which was set to 3.55Hz or 2.5 times the heart rate of the subject to avoid the influence of harmonics on the signal, could not be observed in any of the individual signals measured by the detectors. An adaptive filter was used to remove the arterial pulsatility from the optical signals. Independent Component Analysis allowed to separate signal components in which the tapping frequency was clearly visible.

  10. Very Fast Estimation of Epicentral Distance and Magnitude from a Single Three Component Seismic Station Using Machine Learning Techniques

    Science.gov (United States)

    Ochoa Gutierrez, L. H.; Niño Vasquez, L. F.; Vargas-Jimenez, C. A.

    2012-12-01

    To minimize adverse effects originated by high magnitude earthquakes, early warning has become a powerful tool to anticipate a seismic wave arrival to an specific location and lets to bring people and government agencies opportune information to initiate a fast response. To do this, a very fast and accurate characterization of the event must be done but this process is often made using seismograms recorded in at least 4 stations where processing time is usually greater than the wave travel time to the interest area, mainly in coarse networks. A faster process can be done if only one three component seismic station is used that is the closest unsaturated station respect to the epicenter. Here we present a Support Vector Regression algorithm which calculates Magnitude and Epicentral Distance using only 5 seconds of signal since P wave onset. This algorithm was trained with 36 records of historical earthquakes where the input were regression parameters of an exponential function estimated by least squares, corresponding to the waveform envelope and the maximum value of the observed waveform for each component in one single station. A 10 fold Cross Validation was applied for a Normalized Polynomial Kernel obtaining the mean absolute error for different exponents and complexity parameters. Magnitude could be estimated with 0.16 of mean absolute error and the distance with an error of 7.5 km for distances within 60 to 120 km. This kind of algorithm is easy to implement in hardware and can be used directly in the field station to make possible the broadcast of estimations of this values to generate fast decisions at seismological control centers, increasing the possibility to have an effective reactiontribute and Descriptors calculator for SVR model training and test

  11. Fast Estimation of Epicentral Distance and Magnitude from a Single Three Component Seismic Station Using Machine Learning Techniques

    Science.gov (United States)

    Ochoa Gutierrez, L. H.; Niño, L. F.; Vargas-Jimenez, C. A.

    2013-05-01

    To minimize adverse effects originated by high magnitude earthquakes, early warning has become a powerful tool to anticipate a seismic wave arrival to an specific location, bringing opportune information to people and government agencies to initiate a fast response. To do this, a very fast and accurate characterization of the event must be done but this process is often made using seismograms recorded in at least four stations where processing time is usually greater than the wave arrival time to the interest area, mainly in seismological coarse networks. A faster process can be done if only one three component seismic station, the closest unsaturated station with respect to the epicenter, is used. Here, we present a Support Vector Regression algorithm which calculates Magnitude and Epicentral Distance using only five seconds of signal since P wave onset. This algorithm was trained with 36 records of historical earthquakes, where the input included regression parameters of an exponential function estimated by least squares, of the waveform envelope and the maximum value of the observed waveform for each component in a single station. A ten-fold Cross Validation was applied for a Normalized Polynomial Kernel obtaining the mean absolute error for different exponents and complexity parameters. The Magnitude could be estimated with 0.16 units of mean absolute error and the distance with an error of 7.5 km for distances within 60 to 120 km. This kind of algorithm is easy to implement in hardware and can be used directly in the field seismological sensor to make the broadcast of estimations of these values possible to generate fast decisions at seismological control centers, increasing the possibility of having an effective reaction.

  12. Rated-voltage enhancement by fast-breaking of the fault current for a resistive superconducting fault current limiter component

    International Nuclear Information System (INIS)

    Park, C.-R.; Kim, M.-J.; Yu, S.-D.; Yim, S.-W.; Kim, H.-R.; Hyun, O.-B.

    2010-01-01

    Performance of a resistive superconducting fault current limiter (SFCL) component is usually limited by temperature rise associated with energy input by fault current application during a fault. Therefore, it is expected that short application of the fault current may enhance the power ratings of the component. This can be accomplished by a combination of a HTS component and a mechanical switch. The fast switch (FS) developed recently enables the fault duration to be as short as 1/2 cycle after a fault. Various second-generation (2G) high temperature superconductors (HTS) and YBCO thin films have been tested. The relation between the rated voltage V and the fault duration time t was found to be V 2 ∼ t -1 . Based upon the relation, we predict that when the FS break the fault current within 1/2 cycle after a fault, the amount of HTS components required to build an SFCL can be reduced by as much as about 60%, of that when breaking the fault current at three cycles.

  13. Optically stimulated luminescence (OSL) of dental enamel for retrospective assessment of radiation exposure

    International Nuclear Information System (INIS)

    Yukihara, E.G.; Mittani, J.; McKeever, S.W.S.; Simon, S.L.

    2007-01-01

    This paper briefly reviews the optically stimulated luminescence (OSL) properties of dental enamel and discusses the potential and challenges of OSL for filling the technology gap in biodosimetry required for medical triage following a radiological/nuclear accident or terrorist event. The OSL technique uses light to stimulate a radiation-induced luminescence signal from materials previously exposed to ionizing radiation. This luminescence originates from radiation-induced defects in insulating crystals and is proportional to the absorbed dose of ionizing radiation. In our research conducted to date, we focused on fundamental investigations of the OSL properties of dental enamel using extracted teeth and tabletop OSL readers. The objective was to obtain information to support the development of the necessary instrumentation for retrospective dosimetry using dental enamel in laboratory, or for in situ and non-invasive accident dosimetry using dental enamel in emergency triage. An OSL signal from human dental enamel was detected using blue, green, or IR stimulation. Blue/green stimulation associated with UV emission detection seems to be the most appropriate combination in the sense that there is no signal from un-irradiated samples and the shape of the OSL decay is clear. Improvements in the minimum detection level were achieved by incorporating an ellipsoidal mirror in the OSL system to maximize light collection. Other possibilities to improve the sensitivity and research steps necessary to establish the feasibility of the technique for retrospective assessment of radiation exposure are also discussed

  14. OSL sensitivity changes during single aliquot procedures: Computer simulations

    DEFF Research Database (Denmark)

    McKeever, S.W.S.; Agersnap Larsen, N.; Bøtter-Jensen, L.

    1997-01-01

    We present computer simulations of sensitivity changes obtained during single aliquot, regeneration procedures. The simulations indicate that the sensitivity changes are the combined result of shallow trap and deep trap effects. Four separate processes have been identified. Although procedures can...... be suggested to eliminate the shallow trap effects, it appears that the deep trap effects cannot be removed. The character of the sensitivity changes which result from these effects is seen to be dependent upon several external parameters, including the extent of bleaching of the OSL signal, the laboratory...

  15. Constraining the timing of palaeosol development in Iranian arid environments using OSL dating

    DEFF Research Database (Denmark)

    Rashidi, Zakieh; Sohbati, Reza; Karimi, Alireza

    2018-01-01

    are compared to investigate the degree of bleaching of quartz OSL in individual samples at the time of deposition. A comparison between the quartz OSL and K-feldspar IR50 ages shows that 12 out of 15 samples were probably well-bleached prior to deposition. The 17 OSL ages constrain at least four broad phases......The ages of palaeosols in arid environments in Iran are constrained using the optically stimulated luminescence (OSL) signal from quartz. The luminescence properties of quartz OSL and K-feldspar infrared stimulated luminescence (IRSL) at 50 °C (IR50) and post-IR IRSL at 290 °C (pIRIR290) signals...

  16. Fast noise level estimation algorithm based on principal component analysis transform and nonlinear rectification

    Science.gov (United States)

    Xu, Shaoping; Zeng, Xiaoxia; Jiang, Yinnan; Tang, Yiling

    2018-01-01

    We proposed a noniterative principal component analysis (PCA)-based noise level estimation (NLE) algorithm that addresses the problem of estimating the noise level with a two-step scheme. First, we randomly extracted a number of raw patches from a given noisy image and took the smallest eigenvalue of the covariance matrix of the raw patches as the preliminary estimation of the noise level. Next, the final estimation was directly obtained with a nonlinear mapping (rectification) function that was trained on some representative noisy images corrupted with different known noise levels. Compared with the state-of-art NLE algorithms, the experiment results show that the proposed NLE algorithm can reliably infer the noise level and has robust performance over a wide range of image contents and noise levels, showing a good compromise between speed and accuracy in general.

  17. Natural and laboratory OSL growth curve–Verification of the basic assumption of luminescence dating

    International Nuclear Information System (INIS)

    Kijek, N.; Chruścińska, A.

    2016-01-01

    The basic assumption of luminescence dating is the equality between the growth curve of OSL generated by the natural radiation and the OSL growth curve reconstructed in laboratory conditions. The dose rates that generate the OSL in nature and in laboratory experiments differ by about ten orders of magnitude. Recently some discrepancies between the natural and laboratory growth curves have been observed. It is important to establish their reasons in order to introduce appropriate correction into the OSL dating protocol or to find a test that allows to eliminate the samples which should not be used for dating. For this purpose, both growth curves, natural and laboratory, were reconstructed by means of computer simulations of the processes occurring in the sample during its deposition time in environment as well as those which occur in a laboratory during dating procedure. The simulations were carried out for three models including one shallow trap, two OSL traps, one disconnected deep and one luminescence center. The OSL model for quartz can be more complex than the one used in the presented simulations, but in spite of that the results show effects of growth curves discrepancies similar to those observed in experiments. It is clear that the consistency of growth curves is not a general feature of the OSL processes, but rather a result of an advantageous configuration of trap parameters. The deep disconnected traps play the key role and their complete filling before the zeroing of OSL signal is a necessary condition of the growth curves' consistency. - Highlights: • Process of OSL growth curve generation in nature and in laboratory was simulated. • Discrepancies between the natural and the laboratory growth curves are observed. • Deep disconnected traps play the key role in growth curve inequality. • Empty deep traps before zeroing of OSL cause the inequality of growth curves.

  18. Analysis of optical bleaching of OSL signal in sediment quartz

    International Nuclear Information System (INIS)

    Przegiętka, K.R.; Chruścińska, A.

    2013-01-01

    The aim of this work was to study the effect of the quality of optical bleaching on the results of OSL (Optically Stimulated Luminescence) dating method. The large aliquots of coarse quartz grains extracted from fluvial deposit were used in the study. The poor, medium and good bleaching were simulated in laboratory with help of Blue LED light source in series of experiments. Then the samples were irradiated with a common laboratory dose. The equivalent doses (DE) were measured by the help of standard Single Aliquot Regeneration (SAR) technique, but obtained DE distributions are analyzed in a new way. The method for recognizing and compensating for partial bleaching is proposed. The conclusions for dating sediment quartz samples are presented and discussed. -- Highlights: ► Bleaching experiments on sediment quartz are performed. ► Blue LED light source incorporated in luminescence reader is used. ► New analysis of data measured by standard SAR OSL technique is proposed. ► The results are promising for recognizing and compensating for partial bleaching

  19. Improvement of the M/S manipulator maintenance at OSL

    International Nuclear Information System (INIS)

    Kuwana, Koichi; Ouchi, Hiroshi; Ito, Yutaka; Sato, Yoshihiro; Midorikawa, Mituhiro; Hayakawa, Tuyoshi

    2010-01-01

    The safeguards inspection samples from the JNFL Rokkasho Reprocessing Plant (RRP) are received and analyzed at the On Site Laboratory (OSL). Since the samples from the input accountancy tank of the RRP contain a lot of fission products, they are treated in a hot-cell line with a M/S (Master /Slave) manipulator. Special equipment and tools were used for the maintenance of the M/S manipulator, especially for the exchange of the M/S manipulator. However, the manipulator exchange work was not easy due to the limitation of the space in the OSL. For solution to this problem, a monorail and monorail hoist equipment was installed onto wall surface of analytical room close to each M/S manipulator, and then it made the exchange of M/S manipulator easy without special equipment and tools. Additionally, operator was freed from the burden of working space arranging for the exchange of M/S manipulator such as removing of analytical equipments. This report represents the improvement of operation for the exchange of M/S manipulator with installation of monorail and hoist equipment. (author)

  20. Investigation of TL, OSL and PTTL properties of Mg2SiO4:Tb dosimeters

    International Nuclear Information System (INIS)

    Oguz, K. F.; Goekce, M.; Karali, T.; Harmansah, C.

    2010-01-01

    In this study thermoluminescence (TL) and optically stimulated luminescence (OSL) properties of Mg 2 SiO 4 :Tb in the form of sintered pellets were investigated. Mg 2 SiO 4 :Tb is a recently developed dosimetric material which offers high sensitivity for TL and OSL in dosimetric applications. Thermoluminescence glow curve of Tb doped Mg 2 SiO 4 samples show a glow peak at about 200 degree Celsius with two small peaks at about 275 and 330 degree Celsius, respectively. OSL experiments showed that blue light (470 nm) is six times more efficient than green light (532 nm) to stimulate the OSL emission. The aim of this study was to determine the TL and OSL fading properties of Mg 2 SiO 4 : Tb using OSL and TL methods. In addition, PTTL properties of the Mg 2 SiO 4 : Tb was investigated by using blue LEDs, UV lamp and blue laser. Investigations on the fading properties also showed that the TL signal fades % 10 in a period of 1 month and OSL signal fades % 10 in a period of 3 month, which then the signal remains relatively stable for longer periods.

  1. LM-OSL signals from some insulators: an analysis of the dependency of the detrapping probability on stimulation light intensity

    DEFF Research Database (Denmark)

    Bulur, E.; Bøtter-Jensen, L.; Murray, A.S.

    2001-01-01

    Optically stimulated luminescence (OSL) signals from various insulators including quartz, Al2O3 : C, BeO and NaCl have been studied using the linear modulation OSL (LM-OSL) technique. LM-OSL is based on the linear increase of the stimulation light power from zero to a maximum during the measurement...... is not always correct. The initial decay rates of the blue (similar to 470 nm) light stimulated constant power OSL decay curves were examined to test the relation between the detrapping rates and the stimulation light intensity. In SiO2, Al2O3 : C and BeO a linear relation between the detrapping rates....... The resultant OSL curve initially increases and then decays after reaching a maximum, The analysis of LM-OSL data usually assumes a linear relationship between the detrapping rate and the stimulation light intensity. However, experiments carried out using various insulators have shown that this assumption...

  2. Detection of oscillatory components in noise signals and its application to fast detection of sodium boiling in LMFBR's

    International Nuclear Information System (INIS)

    Ehrhardt, J.

    1975-09-01

    In general, the surveillance of technical plants is performed by observating the mean value of measured signals. In this method not all information included in these signals is used. On the other hand - for example in a reactor - disturbances are possible which generate small oscillatory components in the measured signals. In general, these oscillatory components do not influence the mean value of the signals and consequently do not activate the conventional control system; however they can be found by analysis of the signal's noise component. For the detection of these oscillatory signals the observation of the frequency spectra of the noise signals is particularly advantageous because they produce peaks at the oscillation frequencies. In this paper a new detection system for the fast detection of suddenly appearing peaks in the frequency spectra of noise signals is presented. The prototype of a compact detection unit was developed which continuously computes the power spectral density (PSD) of noise signals and simultaneously supervises the PSD for peaks in the relevant frequency range. The detection method is not affected by the frequency dependance of the PSD and is applicable to any noise signal. General criteria were developed to enable the determination of the optimal detection system and its sensitivity. The upper limits of false alarm rate and detection time were taken into account. The detection criteria are applicable to all noise signals with approximately normally distributed amplitudes. Theoretical results were confirmed in a number of experiments; special experimental and theoretical parameter studies were done for the optimal detection of sodium boiling in LMFBR's. Computations based on these results showed that local and integral sodium boiling can be detected in a wide core range of SNR 300 by observing fluctuations of the neutron flux. In this connection it is important to point out that no additional core instrumentation is necessary because the

  3. OSL response bleaching of BeO samples, using fluorescent light and blue LEDs

    International Nuclear Information System (INIS)

    Groppo, Daniela Piai; Caldas, Linda V.E.

    2015-01-01

    The optically stimulated luminescence (OSL) is widely used as a dosimetric technique for many applications. In this work, the OSL response bleaching of BeO samples was studied. The samples were irradiated using a beta radiation source ( 90 Sr+ 90 Y); the bleaching treatments (fluorescent light and blue LEDs) were performed, and the results were compared. Various optical treatment time intervals were tested until reaching the complete bleaching of the OSL response. The best combination of the time interval and bleaching type was analyzed. (author)

  4. Pilot study: relative dose of the TLD, OSL and Radiochromic film applied in CT exams dosimetry

    International Nuclear Information System (INIS)

    Kikuti, C.F.; Maia, R.S.I.; Romano, R.F.T.; Daros, K. A.C.

    2015-01-01

    At DDI/UNIFESP, the abdomen and chest CT exams correspond to 38% of the exams, becoming the focus of studies. The aim of this study is to assess the relative dose using TLDs, OSLs and RF for the evaluation of the dose distribution in the skin in abdomen CT exams. The simulation of the CT exam was performed in an anthropomorphic phantom, using a CT scanner Philips, Brilliance/64 and TLDs, OSLs and RF fixed along the sagittal axis of the phantom. The OSLs showed similar performance to the TLDs and RF shows low accuracy, resulting in an average value (0.927±0.022). (author)

  5. OSL response bleaching of BeO samples, using fluorescent light and blue LEDs

    International Nuclear Information System (INIS)

    Groppo, D P; Caldas, L V E

    2016-01-01

    The optically stimulated luminescence (OSL) is widely used as a dosimetric technique for many applications. In this work, the OSL response bleaching of BeO samples was studied. The samples were irradiated using a beta radiation source ("9"0Sr+"9"0Y); the bleaching treatments (fluorescent light and blue LEDs) were performed, and the results were compared. Various optical treatment time intervals were tested until reaching the complete bleaching of the OSL response. The best combination of the time interval and bleaching type was analyzed. (paper)

  6. Pilot study: relative dose of the TLD, OSL and Radiochromic film applied in CT exams dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Kikuti, C.F. [Universidade Federal do Mato Grosso do Sul (UFMS), Campo Grande, MS (Brazil). Hospital Universitario Maria Aparecida Pedrossian; Maia, R.S.I.; Romano, R.F.T.; Daros, K. A.C., E-mail: daros.kellen@unifesp.br [Universidade Federal de Sao Paulo (UNIFESP), Sao Paulo, SP (Brazil). Escola Paulista de Medicina. Departamento de Diagnostico por Imagem

    2015-07-01

    At DDI/UNIFESP, the abdomen and chest CT exams correspond to 38% of the exams, becoming the focus of studies. The aim of this study is to assess the relative dose using TLDs, OSLs and RF for the evaluation of the dose distribution in the skin in abdomen CT exams. The simulation of the CT exam was performed in an anthropomorphic phantom, using a CT scanner Philips, Brilliance/64 and TLDs, OSLs and RF fixed along the sagittal axis of the phantom. The OSLs showed similar performance to the TLDs and RF shows low accuracy, resulting in an average value (0.927±0.022). (author)

  7. OSL surface exposure dating of a lithic quarry in Tibet: Laboratory validation and application

    DEFF Research Database (Denmark)

    Gliganic, L.A.; Meyer, M.C.; Sohbati, R.

    2018-01-01

    developed OSL Surface exposure dating technique (OSL-Surf) to date flake scars at lithic quarry sites. We performed the first quantitative validation of the model describing the OSL-Surf dating technique using a controlled laboratory experiment. Our results show that longer laboratory bleaching durations......-depth profile that could be used to calibrate the model to estimate the exposure duration of a flake scar associated with human exploitation of the area. Finally, we observe that the μ parameter of the OSL-Surf model varies considerably between the laboratory-bleached and two naturally daylight-bleached...... datasets, despite having identical lithologies. We thus infer that, in addition to lithological controls, the μ parameter is primarily sensitive to the daylight irradiation geometry and only weakly dependent on spectrum of the incident light; this interpretation implies a narrow effective bleaching...

  8. Measurements of eye lens doses in interventional cardiology using OSL and electronic dosemeters

    International Nuclear Information System (INIS)

    Sanchez, R.M.; Vano, E.; Fernandez, J.M.; Ginjaume, M.; Duch, M.A.

    2014-01-01

    The purpose of this paper is to test the appropriateness of OSL and electronic dosemeters to estimate eye lens doses at interventional cardiology environment. Using TLD as reference detectors, personal dose equivalent was measured in phantoms and during clinical procedures. For phantom measurements, OSL dose values resulted in an average difference of 215 % vs. TLD. Tests carried out with other electronic dosemeters revealed differences up to ±20 % versus TLD. With dosemeters positioned outside the goggles and when TLD doses were >20 μSv, the average difference OSL vs. TLD was 29 %. Eye lens doses of almost 700 μSv per procedure were measured in two cases out of a sample of 33 measurements in individual clinical procedures, thus showing the risk of high exposure to the lenses of the eye when protection rules are not followed. The differences found between OSL and TLD are acceptable for the purpose and range of doses measured in the survey (authors)

  9. Passive dosimetry: introduction of a new dosimeter based on OSL technology

    International Nuclear Information System (INIS)

    Archambault, V.; Le Roy, G.; Prugnaud, B.

    2005-01-01

    A new passive dosimeter based on OSL technology has been introduced on the French market. In this article are described: the technology and the material on which this new detector relied, the dosimeter itself. (author)

  10. Implementation of a OSL dosimetry laboratory at IRD/CNEN-BR

    International Nuclear Information System (INIS)

    Moura, Jose; Alencar, Marcus A. Vallim de; Mauricio, Claudia L.P.; Hunt, John

    2005-01-01

    The optically stimulated luminescence (OSL) it is a phenomenon characterized by the luminous emission of an insulating material or semiconductor, during your exhibition to the light, after it being previously exposed to the ionizing radiation. This phenomenon has been used more and more in the dosimetry of the ionizing radiations, why the intensity OSL of some materials is proportional to the absorbed dose in these. The processes OSL and thermoluminescence (TL) they only differ in the stimulation form for light emission. One of the advantages of the OSL process in relation to the traditional technique of TL dosimetry is the no complete destruction of the information of the absorbed dose in the material during the reading. Following this world tendency, the External Individual Monitoring Service of the Institute of Radioprotection and Dosimetry (SEMEX/IRD) implemented the OSL dosimetry laboratory. The acquired reader was the reader model LAUGHTER TL/OSL-GIVE-15B/C. With that reader it is possible to do readings TL and OSL. After the installation of the equipment in a darkroom with temperature and humidity controlled, they were made the preliminary tests with the equipment and the laboratory became operational. After this first stage, they were initiate the studies with the Al 2 O 3 :C dosimeters by Harshaw under the denomination TLD 500. The reading parameters and thermal treatment were optimized to study the applicability of OSL technique with the TLD 500 dosimeter for the use in environmental monitoring. It was also verified the linearity of the system for high doses (10 mGy-1 Gy) seeking your use in radiotherapy, as well as the effect of the thermal treatment in the OSL signal of the Al 2 O 3 :C dosimeter. The results prove the possibility of use of this system in environmental monitoring. The reproductivity of the system for the air kerma value of 100 mGy, considering a degree of confidence of 95%, was to 4,8% for OSL readings and 5,6% for TL. In the two cases

  11. The preliminary application of OSL in comparison with TL for authentication of ancient Chinese bricks

    International Nuclear Information System (INIS)

    Leung, P.L.; Tang Qiang; Li, Mike; Zhang Chunxiang

    2005-01-01

    The single-aliquot regenerative-dose (SAR) protocol with optically stimulated luminenscence (OSL) was applied to measure the equivalent dose (ED) of ancient Chinese bricks ranging in age from 180 to 1600 years. In the protocol, sensitivity changes can be corrected by using OSL response to a fixed test dose during measurement. For comparative study between OSL and TL, thermoluminescence (TL) measurement procedures were also applied to determine the paleodose of the bricks. Both results of OSL and TL are in agreement with the known ages of the bricks, and the paleodose ratios(ED OSL / ED TL ) are between 0.96 and 1.21, mean value 1.08+/-0.02. The annual doses of the bricks, estimated by the paleodoses and the known ages, range from 5.07 to 6.79mGy/a, comparable with the measured annual dose values of the bricks. Therefore, it is concluded that the SAR protocol is a rapid and effective OSL technique to authenticate Chinese bricks

  12. A comparative study between OSL and TL techniques for the dating of ancient chinese bricks

    International Nuclear Information System (INIS)

    Leung, P.L.; Li, M.; Tang Qiang; Zhang Chunxiang

    2004-01-01

    The single-aliquot regenerative-dose (SAR) protocol to the optically stimulated luminescence (OSL) was applied to measure the paleodose of ancient Chinese bricks with an age range from 180 to 1600 years. In the protocol, sensitivity changes can be corrected by using OSL response to a fixed test dose during measurement. For comparative study between OSL and TL, thermoluminescence (TL) measurement procedures were also applied to determine the paleodose of the bricks. Both results of OSL and TL are in good agreement with, and the paleodose ratios (De OSL /De TL ) are between 0.96 and 1.21, with a mean value of 1.08 ± 0.07. The annual dose of the bricks, estimated by the paleodoses and the known ages, ranges from 5.07 to 6.85 mGy/a, comparable with the measured annual dose values. Therefore, it is concluded that the SAR protocol is a rapid and effective OSL technique to authenticate Chinese bricks. (authors)

  13. Joint estimation of the fast and thermal components of a high neutron flux with a two on-line detector system

    International Nuclear Information System (INIS)

    Filliatre, P.; Oriol, L.; Jammes, C.; Vermeeren, L.

    2009-01-01

    A fission chamber with a 242 Pu deposit is the best suited detector for on-line measurements of the fast component of a high neutron flux (∼10 14 ncm -2 s -1 or more) with a significant thermal component. To get the fast flux, it is, however, necessary to subtract the contribution of the thermal neutrons, which increases with fluence because of the evolution of the isotopic content of the deposit. This paper presents an algorithm that permits, thanks to measurements provided by a 242 Pu fission chamber and a detector for thermal neutrons, to estimate the thermal and the fast flux at any time. An implementation allows to test it with simulated data.

  14. Joint estimation of the fast and thermal components of a high neutron flux with a two on-line detector system

    Energy Technology Data Exchange (ETDEWEB)

    Filliatre, P. [CEA, DEN, SPEx/LDCI, F-13108 Saint-Paul-lez-Durance (France); Laboratoire Commun d' Instrumentation CEA-SCK-CEN (France)], E-mail: philippe.filliatre@cea.fr; Oriol, L.; Jammes, C. [CEA, DEN, SPEx/LDCI, F-13108 Saint-Paul-lez-Durance (France); Laboratoire Commun d' Instrumentation CEA-SCK-CEN (France); Vermeeren, L. [SCK-CEN, Boeretang 200, B-2400 Mol (Belgium); Laboratoire Commun d' Instrumentation CEA-SCK-CEN (France)

    2009-05-21

    A fission chamber with a {sup 242}Pu deposit is the best suited detector for on-line measurements of the fast component of a high neutron flux ({approx}10{sup 14}ncm{sup -2}s{sup -1} or more) with a significant thermal component. To get the fast flux, it is, however, necessary to subtract the contribution of the thermal neutrons, which increases with fluence because of the evolution of the isotopic content of the deposit. This paper presents an algorithm that permits, thanks to measurements provided by a {sup 242}Pu fission chamber and a detector for thermal neutrons, to estimate the thermal and the fast flux at any time. An implementation allows to test it with simulated data.

  15. Insight into the genetic components of community genetics: QTL mapping of insect association in a fast-growing forest tree.

    Directory of Open Access Journals (Sweden)

    Jennifer DeWoody

    Full Text Available Identifying genetic sequences underlying insect associations on forest trees will improve the understanding of community genetics on a broad scale. We tested for genomic regions associated with insects in hybrid poplar using quantitative trait loci (QTL analyses conducted on data from a common garden experiment. The F2 offspring of a hybrid poplar (Populus trichocarpa x P. deltoides cross were assessed for seven categories of insect leaf damage at two time points, June and August. Positive and negative correlations were detected among damage categories and between sampling times. For example, sap suckers on leaves in June were positively correlated with sap suckers on leaves (P<0.001 but negatively correlated with skeletonizer damage (P<0.01 in August. The seven forms of leaf damage were used as a proxy for seven functional groups of insect species. Significant variation in insect association occurred among the hybrid offspring, including transgressive segregation of susceptibility to damage. NMDS analyses revealed significant variation and modest broad-sense heritability in insect community structure among genets. QTL analyses identified 14 genomic regions across 9 linkage groups that correlated with insect association. We used three genomics tools to test for putative mechanisms underlying the QTL. First, shikimate-phenylpropanoid pathway genes co-located to 9 of the 13 QTL tested, consistent with the role of phenolic glycosides as defensive compounds. Second, two insect association QTL corresponded to genomic hotspots for leaf trait QTL as identified in previous studies, indicating that, in addition to biochemical attributes, leaf morphology may influence insect preference. Third, network analyses identified categories of gene models over-represented in QTL for certain damage types, providing direction for future functional studies. These results provide insight into the genetic components involved in insect community structure in a fast

  16. Radiocromic film, TLD, OSL and 'Paracas Phantom' by dosimetric intercomparation in stereotactic radiosurgery

    International Nuclear Information System (INIS)

    Paucar Jauregui, R.; Condori Marcos, P.; Vidarte Garcia, F.

    2008-01-01

    Full text: In Peru, one deals to patients with arteriovenous malformations or cerebral tumors by means of stereotactic radiosurgery, using fine photon beams of high energy of 6 MeV, generated by a linear accelerator Varian 2100 Clinac CD of the Complejo Hospitalario San Pablo in Lima, Peru. In this work we describes the 'Dosimetric Intercomparation System of the Quality Assurance Program in Stereotactic Radiosurgery of the Complejo Hospitalario San Pablo (DIS)'. The DIS allows to guarantee application of the doses with high accuracy. It shows the good performance of the Local DIS's components: dosimetry of radiocromics films, dosimetry termoluminiscent (TLD), dosimetry of optically stimulated luminescence (OSL) and an anthropomorphic phantom of head constructed locally, denominated 'Paracas Phantom'. Also, in the International DIS practiced with The University of Texas Md Anderson Cancer Center, stands out results within the ranges: a) Dose to the center of the target (RDS/Institution): 0,95-1,05; b) Treated volumen (Measured/Institution): 0,75 - 1,05; c) Ratio of measure treated volume to target volume: 1,00 - 2,00; and d) Minimum dose to target (Minimum dose/Prescription dose): >0,90. It concludes that the DIS is important for the good decision making on the radiological safety of the patients dealt with stereotactic radiosurgery. (author)

  17. TL and OSL dosimetric properties of Opal gemstone for gamma radiation dosimetry

    International Nuclear Information System (INIS)

    Antonio, Patrícia L.; Gronchi, Claudia C.; Oliveira, Raquel A.P.; Khoury, Helen J.; Caldas, Linda V.E.

    2016-01-01

    In this work, the response of the natural material Opal was studied in relation to its thermoluminescence (TL) and optically stimulated luminescence (OSL), after exposure to the gamma radiation of a "6"0Co source. The structure of the powdered Opal was verified using the X-ray diffraction, scanning electronic microscopy and energy-dispersive X-ray spectroscopy techniques. The material, in its stone form, was turned into powder and mixed to Teflon (also in powder) in three different concentrations, and then pellets were manufactured. The aim of this work was to evaluate the response of these pellets in high-doses of gamma radiation beams, and to observe their possible application as dosimeters, using the TL and OSL techniques. The dosimetric properties of the samples were analyzed by means of different tests, as: TL emission curves and OSL signal decay curves, reproducibility of TL and OSL response, minimum detectable dose, TL and OSL dose–response curves (5 Gy–10 kGy), and fading. The results obtained in this work, for the TL and OSL phenomena, demonstrated that the pellets of Opal + Teflon present an adequate performance e possibility of use as dosimeters in beams of high-dose gamma radiation. - Highlights: • The XRD, SEM and EDX techniques were used to investigate powdered Opal. • Pellets of three different concentrations of Opal and Teflon were studied. • The dosimetric properties of the Opal + Teflon pellets were verified. • TL and OSL techniques were used to analyze the characteristics of the pellets. • Pellets of concentration of 2:1 (Opal:Teflon) presented the most adequate results.

  18. Metabolic syndrome components and diabetes incidence according to the presence or absence of impaired fasting glucose: The Japan Epidemiology Collaboration on Occupational Health Study.

    Science.gov (United States)

    Kurotani, Kayo; Miyamoto, Toshiaki; Kochi, Takeshi; Eguchi, Masafumi; Imai, Teppei; Nishihara, Akiko; Tomita, Kentaro; Uehara, Akihiko; Yamamoto, Makoto; Murakami, Taizo; Shimizu, Chii; Shimizu, Makiko; Nagahama, Satsue; Nakagawa, Tohru; Honda, Toru; Yamamoto, Shuichiro; Okazaki, Hiroko; Sasaki, Naoko; Hori, Ai; Nishiura, Chihiro; Kuwahara, Keisuke; Kuroda, Reiko; Akter, Shamima; Kashino, Ikuko; Nanri, Akiko; Kabe, Isamu; Mizoue, Tetsuya; Kunugita, Naoki; Dohi, Seitaro

    2017-09-01

    We prospectively examined the association of diabetes risk with the number of metabolic abnormalities, as well as their combinations, according to the presence or absence of impaired fasting glucose (IFG) in a large-scale Japanese working population. Participants included 55,271 workers at 11 companies who received periodic health check-ups between 2008 and 2013. The metabolic syndrome (MetS) components were defined using the 2009 Joint Interim Statement. IFG was defined as fasting plasma glucose 5.6-6.9 mmol/L. Diabetes newly diagnosed after the baseline examination was defined according to the American Diabetes Association criteria. We calculated the hazard ratios (HRs) for diabetes incidence using the Cox proportional hazards model. During the follow-up period (median 4.95 years), 3183 subjects developed diabetes. In individuals with normal fasting glucose levels, the risk of diabetes increased steadily with the increasing number of MetS components; the multivariable-adjusted HRs for incident diabetes for the number of MetS components were 2.0, 4.3, 7.0, and 10.0 for one, two, three, or four MetS components, respectively, compared with the absence of components. A similar association was observed among individuals with IFG; the corresponding HRs were 17.6, 23.8, 33.9, and 40.7. The combinations that included central obesity appeared to be more strongly associated with diabetes risk than other combinations with the same number of MetS components within the same glucose status. Our findings indicate that risk stratification of individuals by the presence or absence of IFG and the number of MetS components can detect individuals with a high risk of diabetes. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  19. Thermal activation of OSL as a geothermometer for quartz grain heating during fault movements

    CERN Document Server

    Rink, W J; Rees-Jones, J; Schwarcz, H P

    1999-01-01

    In discussions of ESR dating of fault movements, there has been much debate whether zeroing of ESR signals is a mechanical shearing effect or caused by frictional heating. The OSL (optically stimulated luminescence) sensitivity of quartz is known to increase after heating. This thermal activation of dose response of the OSL in quartz should be useful as a geothermometer to test whether quartz particles in fault gouge had been heated. We tested the OSL sensitivities of quartz from fault gouge, and from a control (quartz grains from sandstone) and were able to show heat-induced enhancement of OSL sensitivity to a test dose. We observed that relative enhancement of OSL dose response (ratio of heated to unheated single aliquots) is significantly less for the finest grains (45-75 and 100-150 mu m) compared with coarser grains (150-250 mu m). These data are consistent with a model of zeroing of the quartz grains during faulting, by frictional heating localized to the grain boundaries, which would be expected to aff...

  20. OSL, TL and IRSL emission spectra of sedimentary quartz and feldspar samples

    International Nuclear Information System (INIS)

    Lomax, Johanna; Mittelstraß, Dirk; Kreutzer, Sebastian; Fuchs, Markus

    2015-01-01

    This contribution presents a variety of different luminescence emission spectra from sedimentary feldspar and quartz samples under various stimulation modes. These are green stimulated quartz (OSL-) spectra, quartz TL spectra, feldspar IRSL and post-IR IRSL spectra. A focus was set at recording OSL and IRSL spectra at elevated stimulation temperatures such as routinely applied in luminescence dating. This was to test whether optical stimulation at elevated temperatures results in a shift of emission peaks. For OSL emissions of quartz, this has so far not been tested. In case of feldspar emissions, post-IR IRSL conditions, hence IRSL emissions at a low temperature, directly followed by high temperature post-IRSL emissions, are explicitly investigated. All spectra were recorded using a new system incorporated into a Lexsyg luminescence reader. Thus, this study, besides presenting new spectral data, also serves as a feasibility study for this new device. It is shown that (a) the new device is capable of automatically measuring different sorts of spectra, also at elevated temperatures, (b) known thermally and optically stimulated peak emissions of quartz and feldspar are confirmed, (c) obtained IRSL and OSL spectra indicate that there is no significant relation between peak emission and stimulation temperature. - Highlights: • We have measured OSL, IRSL and TL emission spectra of sedimentary quartz and feldspar samples. • Spectral analyses were performed at elevated stimulation temperatures. • Emission spectra show very little variation with stimulation temperatures.

  1. Angular dependence of the nanoDot OSL dosimeter

    International Nuclear Information System (INIS)

    Kerns, James R.; Kry, Stephen F.; Sahoo, Narayan; Followill, David S.; Ibbott, Geoffrey S.

    2011-01-01

    Purpose: Optically stimulated luminescent detectors (OSLDs) are quickly gaining popularity as passive dosimeters, with applications in medicine for linac output calibration verification, brachytherapy source verification, treatment plan quality assurance, and clinical dose measurements. With such wide applications, these dosimeters must be characterized for numerous factors affecting their response. The most abundant commercial OSLD is the InLight/OSL system from Landauer, Inc. The purpose of this study was to examine the angular dependence of the nanoDot dosimeter, which is part of the InLight system. Methods: Relative dosimeter response data were taken at several angles in 6 and 18 MV photon beams, as well as a clinical proton beam. These measurements were done within a phantom at a depth beyond the build-up region. To verify the observed angular dependence, additional measurements were conducted as well as Monte Carlo simulations in MCNPX. Results: When irradiated with the incident photon beams parallel to the plane of the dosimeter, the nanoDot response was 4% lower at 6 MV and 3% lower at 18 MV than the response when irradiated with the incident beam normal to the plane of the dosimeter. Monte Carlo simulations at 6 MV showed similar results to the experimental values. Examination of the results in Monte Carlo suggests the cause as partial volume irradiation. In a clinical proton beam, no angular dependence was found. Conclusions: A nontrivial angular response of this OSLD was observed in photon beams. This factor may need to be accounted for when evaluating doses from photon beams incident from a variety of directions.

  2. Proposals for in-service inspection and monitoring of selected components located within or part of the primary containment of sodium cooled fast reactors

    International Nuclear Information System (INIS)

    Bolt, P.R.

    1976-01-01

    Design and operational experience of CEGB gas cooled reactors and certain overseas reactor plant is reviewed in relation to in-service inspection and monitoring capabilities. Design guidelines and preliminary proposals are given for in-service inspection and monitoring of selected components located within or part of the primary containment of sodium cooled fast reactors. Specific comments are made on the items of further design and development work believed to be necessary

  3. A new luminescence detection and stimulation head for the Risø TL/OSL reader

    International Nuclear Information System (INIS)

    Lapp, T.; Kook, M.; Murray, A.S.; Thomsen, K.J.; Buylaert, J.-P.; Jain, M.

    2015-01-01

    A new automated Detection And Stimulation Head (DASH) has been developed for the Risø TL/OSL luminescence reader to provide easy access to new technologies, new signals and new measurement methods. The automated DASH includes a filter changer and a detector changer that makes it possible to change stimulation filters (4 × 4 filter combinations possible) and detectors (3 detectors possible) as part of a measurements sequence. The new automated DASH with dedicated driver electronics does not affect the use of other attachments, and can be retrospectively fitted to existing Risø TL/OSL readers. - Highlights: • A new detection and stimulation head for the Risø TL/OSL reader is described. • An example of the use of the filter changer is presented. • The power and spatial uniformity of blue, green and IR stimulation are characterised. • The potential of an EMCCD camera detector is described.

  4. Optically stimulated luminescence (OSL) and some other luminescence images from granite slices exposed with radiations

    International Nuclear Information System (INIS)

    Hashimoto, T.; Notoya, S.; Ojima, T.; Hoteida, M.

    1995-01-01

    Optically stimulated luminescence (OSL) images of some X- and γ-irradiated granite slices were obtained using photon detection through a 570 nm bandpass filter with diode-laser excitation of 910 nm. Alternative photo-induced phosphorescence (PIP) images, which were colour photographed immediately after the sunlight exposure of slice samples, were also found to be helpful in the observation of the luminescence properties and to filter selection for OSL measurements. These OSL and PIP images were compared with some other colour luminescence images, including thermoluminescence images (TLCI) and after-glow images (AGCI). It was obvious that there exists a variety of coloured emissions derived mainly from feldspar constituents and these were found to be dependent on the geological history or metamorphism of the granites. (Author)

  5. Study of optically stimulated luminescence (OSL) for radiation detection. Application to an optical fibre {gamma}-radiation sensor; Etude de la luminescence stimulee optiquement (OSL) pour la detection de rayonnements: application a un capteur a fibre optique de rayonnement {gamma}

    Energy Technology Data Exchange (ETDEWEB)

    Roy, O. [CEA Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Electronique et d`Instrumentation Nucleaire]|[Paris-7 Univ., 75 (France)

    1998-12-31

    This work shows up the usefulness of the Optically Stimulated Luminescence (OSL) to resolve radioprotection problems. We study the use of OSL as a gamma dosimetric technique with respect to the ALARA`s concept (As Low As Reasonably Achievable). A new approach based on optical fibers and luminescent materials showing OSL properties (closely related to Thermoluminescence phenomena) is presented in order to improve the remote real time dosimetry monitoring. Like thermoluminescent materials (TLD), OSL materials can trap charges under an irradiation (UV, X, {gamma},...). Instead of heating, the charges trapped are released by light stimulation and produce a visible luminescence which amount is proportional to trap the `data stored` left by irradiation, enabling the dose measurement. The OSL phenomenon offers the same advantages as TLD plus the interesting possibility of a remote optical stimulation. The end-user objective deals with the development of a {gamma}-radiation Optical FIber Sensor (OFS) for dose measurement which can offer new functionalities based on OSL materials coupled with an optical fiber. Rare earth doped Alkaline Earth Sulphides (AES), BAFX:EU{sup 2+} (X = Cl, Br, I) and halogen alkaline have been studied (crystalline form, synthesis techniques, influence of dopants and color centers). Their characteristics are presented and extensively discussed. A specific experimental set-up to characterise various OSL phosphors has been developed. It allows the study of sensitivity, linearity, time decay behaviour of OSL signal and zeroing time. A joint study of OSL and TL has shown the technical limitations as well as the thermal fading and the origin of the long zeroing time. An Optical Fiber Sensor (OFS) based on OSL and using MgS:Sm has been developed for practical applications on nuclear fields. Its specifications are presented and discussed, moreover improvements are proposed. (author) 320 refs.

  6. OSL and TL retrospective dosimetry with a fluorapatite glass-ceramic used for dental restorations

    International Nuclear Information System (INIS)

    Ekendahl, Daniela; Judas, Libor; Sukupova, Lucie

    2013-01-01

    Optically Stimulated Luminescence (OSL) and Thermoluminescence (TL) properties of a fluorapatite glass-ceramic have been investigated, with a view to developing a dose assessment technique for medical triage following unplanned exposures of individuals to ionizing radiation. The ceramic is an innovative material used in dental prostheses and restorations. It is strongly sensitive to radiation and the intensity of both the OSL and TL signals are proportional to the absorbed radiation dose. We focused on the optimization of the measuring procedure and investigated characteristics such as reproducibility, fading, minimum detectable dose (MDD), dose response and photon energy response of TL and OSL signals. The dental ceramic exhibited very good reproducibility (<5% at 2σ level) when measured and a linear dose response for a wide range of doses (50 mGy–20 Gy). The MDD values for the samples investigated were ∼5 mGy. The material is not tissue equivalent and the OSL and TL signals are strongly dependent on incident photon energy. Both the luminescence signals exhibited significant fading during the first few hours after irradiation. Its rate was dependent on the parameters of measurement. The results indicate that the material can be used for the purposes of accident dosimetry, however, the fading and photon energy response have to be properly corrected for a reliable dose assessment. - Highlights: ► A dental ceramic was considered as a retrospective and accident dosimeter. ► Dosimetry application was investigated using OSL and TL. ► TL and OSL signals are proportional to absorbed radiation dose. ► Accuracy is dependent on correction of fading and photon energy response

  7. Optically stimulated luminescence (OSL) from Ag-doped Li2B4O7 crystals

    International Nuclear Information System (INIS)

    Kananen, B.E.; Maniego, E.S.; Golden, E.M.; Giles, N.C.; McClory, J.W.; Adamiv, V.T.; Burak, Ya.V.; Halliburton, L.E.

    2016-01-01

    Optically stimulated luminescence (CW-OSL) is observed from Ag-doped lithium tetraborate (Li 2 B 4 O 7 ) crystals. Photoluminescence, optical absorption, and electron paramagnetic resonance (EPR) are used to identify the defects participating in the OSL process. As-grown crystals have Ag + ions substituting for Li + ions. They also have Ag + ions occupying interstitial sites. During a room-temperature exposure to ionizing radiation, holes are trapped at the Ag + ions that replace Li + ions and electrons are trapped at the interstitial Ag + ions, i.e., the radiation forms Ag 2+ (4d 9 ) ions and Ag 0 (4d 10 5s 1 ) atoms. These Ag 2+ and Ag 0 centers have characteristic EPR spectra. The Ag 0 centers also have a broad optical absorption band peaking near 370 nm. An OSL response is observed when the stimulation wavelength overlaps this absorption band. Specifically, stimulation with 400 nm light produces an intense OSL response when emission is monitored near 270 nm. Electrons optically released from the Ag 0 centers recombine with holes trapped at Ag 2+ ions to produce the ultraviolet emission. The OSL response is progressively smaller as the stimulation light is moved to longer wavelengths (i.e., away from the 370 nm peak of the absorption band of the Ag 0 electron traps). Oxygen vacancies are also present in the Ag-doped Li 2 B 4 O 7 crystals, and their role in the OSL process as a secondary relatively short-lived electron trap is described.

  8. Thermal activation of OSL as a geothermometer for quartz grain heating during fault movements

    International Nuclear Information System (INIS)

    Rink, W.J.; Toyoda, S.; Rees-Jones, J.; Schwarcz, H.P.

    1999-01-01

    In discussions of ESR dating of fault movements, there has been much debate whether zeroing of ESR signals is a mechanical shearing effect or caused by frictional heating. The OSL (optically stimulated luminescence) sensitivity of quartz is known to increase after heating. This thermal activation of dose response of the OSL in quartz should be useful as a geothermometer to test whether quartz particles in fault gouge had been heated. We tested the OSL sensitivities of quartz from fault gouge, and from a control (quartz grains from sandstone) and were able to show heat-induced enhancement of OSL sensitivity to a test dose. We observed that relative enhancement of OSL dose response (ratio of heated to unheated single aliquots) is significantly less for the finest grains (45-75 and 100-150 μm) compared with coarser grains (150-250 μm). These data are consistent with a model of zeroing of the quartz grains during faulting, by frictional heating localized to the grain boundaries, which would be expected to affect smaller grains more than large ones. This argues against a zeroing model in which the entire fault gouge is heated by friction. Higher laboratory preheating of sandstone quartz reduces between-aliquot variability of OSL dose response in the unheated grains to nearly zero. Unheated coarsest fault gouge grains displayed virtually no among-aliquot variability, whereas fine grains showed much larger between-aliquot variability; as with the quartz sand, variability dropped to near zero after laboratory heating, suggesting that fine grains in fault gouge have experienced a wide range of natural thermal histories during faulting. This may present a problem for ESR dating of fault gouge using the plateau method

  9. OSL and IRSL characteristics of quartz and feldspar from southern California, USA

    International Nuclear Information System (INIS)

    Lawson, Michael J.; Roder, Belinda J.; Stang, Dallon M.; Rhodes, Edward J.

    2012-01-01

    Southern California comprises of a wide range of diverse landscapes and environments, from high mountains with glacial and periglacial sediments to deserts with large sand dunes, extensive alluvial fans and ephemeral playas. Highly active tectonic processes has exposed ancient (c. 2 Ga) plutonic and metamorphic basement from deep within the crust, while similar Palaeozoic, Mesozoic and Cenozoic rocks are also common. A rich array of volcanic lithologies extending into the late Quaternary complement many thick sedimentary sequences that formed in equally diverse ancient environments typical of an accreting active continental margin. In some locations, notably in the Coachella Valley close to Palm Springs and the Salton Sea, low OSL sensitivity and poor characteristics restrict the application of the quartz SAR protocol to date late Pleistocene and Holocene fluvial sediments. In other locations such as the Malibu coastline, high sensitivity of the quartz OSL signal is observed, despite local source rocks being dominated by volcanic lithologies. Problems of poor quartz characteristics, along with uncertainty in predicting quartz OSL behavior for future dating campaigns poses a significant problem for projects, in particular for neotectonic contexts. While K-feldspar has been used extensively to date eolian and fluvial sediments in southern California, little information regarding signal stability is available. We explore the characteristics of both quartz and feldspar sub-samples from eolian, fluvial, lacustrine environments, in order to help develop mineral selection criteria for optical dating applications and clarify these issues. The importance of radiation quenching in quartz grains recently eroded from bedrock and the role of fires in enhancing OSL sensitivity are considered. The relative bleachability of quartz and feldspar fractions, along with thermal stability considerations is discussed. A simple test for quartz OSL signal contamination based on thermal

  10. Study of optically stimulated luminescence (OSL) for radiation detection. Application to an optical fibre γ-radiation sensor

    International Nuclear Information System (INIS)

    Roy, O.

    1998-01-01

    This work shows up the usefulness of the Optically Stimulated Luminescence (OSL) to resolve radioprotection problems. We study the use of OSL as a gamma dosimetric technique with respect to the ALARA's concept (As Low As Reasonably Achievable). A new approach based on optical fibers and luminescent materials showing OSL properties (closely related to Thermoluminescence phenomena) is presented in order to improve the remote real time dosimetry monitoring. Like thermoluminescent materials (TLD), OSL materials can trap charges under an irradiation (UV, X, γ,...). Instead of heating, the charges trapped are released by light stimulation and produce a visible luminescence which amount is proportional to trap the 'data stored' left by irradiation, enabling the dose measurement. The OSL phenomenon offers the same advantages as TLD plus the interesting possibility of a remote optical stimulation. The end-user objective deals with the development of a γ-radiation Optical FIber Sensor (OFS) for dose measurement which can offer new functionalities based on OSL materials coupled with an optical fiber. Rare earth doped Alkaline Earth Sulphides (AES), BAFX:EU 2+ (X = Cl, Br, I) and halogen alkaline have been studied (crystalline form, synthesis techniques, influence of dopants and color centers). Their characteristics are presented and extensively discussed. A specific experimental set-up to characterise various OSL phosphors has been developed. It allows the study of sensitivity, linearity, time decay behaviour of OSL signal and zeroing time. A joint study of OSL and TL has shown the technical limitations as well as the thermal fading and the origin of the long zeroing time. An Optical Fiber Sensor (OFS) based on OSL and using MgS:Sm has been developed for practical applications on nuclear fields. Its specifications are presented and discussed, moreover improvements are proposed. (author)

  11. Role of Thickness Confinement on Relaxations of the Fast Component in a Miscible A/B Blend

    Energy Technology Data Exchange (ETDEWEB)

    Green, Peter [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sharma, Ravi P. [University of Michigan; Dong, Ban Xuan [University of Michigan

    2018-01-18

    Spatial compositional heterogeneity strongly influences the dynamics of the A and B components of bulk miscible blends. Its effects are especially apparent in mixtures, such as poly(vinyl methyl ether) (PVME)/polystyrene (PS), where there exist significant disparities between the component glass transition temperatures (Tgs) and relaxation times. The relaxation processes characterized by distinct temperature dependencies and relaxation rates manifest different local compositional environments for temperatures above and below the glass transition temperature of the miscible blend. This same behavior is shown to exist in miscible PS/PVME films as thin as 100 nm. Moreover, in thin films, the characteristic segmental relaxation times t of the PVME component of miscible PVME/PS blends confined between aluminum (Al) substrates decrease with increasing molecular weight M of the PS component. These relaxation rates are film thickness dependent, in films up to a few hundred nanometers in thickness. This is in remarkable contrast to homopolymer films, where thickness confinement effects are apparent only on length scales on the order of nanometers. These surprisingly large length scales and M dependence are associated with the preferential interfacial enrichment - wetting layer formation - of the PVME component at the external Al interfaces, which alters the local spatial blend composition within the interior of the film. The implications are that the dynamics of miscible thin film blends are dictated in part by component Tg differences, disparities in component relaxation rates, component-substrate interactions, and chain lengths (entropy of mixing).

  12. How to use the ENEA data bank for the classification and reliability processing of fast reactor component event data

    International Nuclear Information System (INIS)

    Righini, R.

    1987-01-01

    This report describes the input and inquiry procedures for the Data Bank set-up by ENEA for reliability studies on fast reactors. With reference to the structure and to the codes to be applied in the data entry and in the inquiry, see Report (2) in references. The data contained into the Bank are absolutely confidential. The input and inquiry procedures describes in this report may be applied only by the user who have previously specified the suitable password

  13. Bioactivity characterization of 45S5 bioglass using TL, OSL and EPR: Comparison with the case of 58S sol-gel bioactive glass

    Energy Technology Data Exchange (ETDEWEB)

    Polymeris, G.S., E-mail: gspolymeris@ankara.edu.tr [Ankara University, Institute of Nuclear Sciences, 06100 Beşevler, Ankara (Turkey); Giannoulatou, V. [Ankara University, Institute of Nuclear Sciences, 06100 Beşevler, Ankara (Turkey); Solid State Section, Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Kyriakidou, A. [Solid State Section, Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Sfampa, I.K. [Nuclear Physics Laboratory, Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Theodorou, G.S. [Solid State Section, Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Şahiner, E.; Meriç, N. [Ankara University, Institute of Nuclear Sciences, 06100 Beşevler, Ankara (Turkey); Kitis, G. [Nuclear Physics Laboratory, Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Paraskevopoulos, K.M. [Solid State Section, Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

    2017-01-01

    The current work exploits the effective application of thermoluminescence (TL), optically stimulated luminescence (OSL) and the possibility of applying Electron Paramagnetic Resonance (EPR) for the discrimination between different bioactive responses in the case of the 45S5 bioactive glass (SiO{sub 2} 45, Na{sub 2}O 24.5, CaO 24.5, P{sub 2}O{sub 5} 6 in wt%), which was synthesized through melting process. These techniques are suggested mainly due to their low spectroscopic detection thresholds. The original 45S5 in grain size range of 20–40 μm was immersed in the Simulated Body Fluid (SBF) for various different immersion times ranging over one week. In this work the 110 °C TL peak, a specific OSL component and the EPR signal at g = 2.013 ascribed to oxygen hole center (OHC) are used due to their sensitivity to the different bioactive responses. For all luminescence and EPR components, the intensity plot versus immersion time yields sharp discontinuities, resulting in effective probes regarding the timescale for both the beginning as well as the end of the procedure of the crystalline HCAp formation respectively. On the contrary to the smooth decreasing pattern of both luminescence entities, the peak to peak amplitude of the EPR signal indicates an initial increase for the initial 16 min of immersion, followed by a further decrease throughout the immersion time duration. The discontinuities monitored for both sensitivity of TL, OSL and EPR, in conjunction with the discontinuities monitored for the sensitization of TL and OSL, when plotted versus immersion time, provide an individual time scale for each one of the chemical reactions involved in the five steps of the aforementioned procedure. According to the authors' best knowledge, scarce characterization techniques could provide this time scale frame, while it is the first time that such an application of OSL and EPR is attempted. Finally, the bioactive response of the 45S5 bioglass was compared with that

  14. A luminescence imaging system for the routine measurement of single-grain OSL dose distributions

    DEFF Research Database (Denmark)

    Kook, Myung Ho; Lapp, Torben; Murray, Andrew

    2015-01-01

    the potential of an electron multiplying charge-coupled device (EMCCD), providing extremely low level light detection. We characterize the performance of the device by discussing reproducibility and evaluating uncertainties in OSL signals. Finally we derive a typical single grain natural dose distribution...

  15. Preliminary results on TL and OSL aluminium oxide dosimeters developed at IPEN

    Energy Technology Data Exchange (ETDEWEB)

    Fukumori, David T.; Yoshito, Walter K.; Ussui, Valter; Lazar, Dolores R.R.; Campos, Leticia L., E-mail: fukumori@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The aluminum oxide composes the modern TL and OSL radiation dosimeters. TL and OSL phenomena are related to chemical elements in the crystalline structure of {alpha}-Al{sub 2}O{sub 3}. The aim of this work was to develop materials based on aluminum oxide for use in TL and OSL dosimetry. The studies included the dosimetric properties of alumina samples obtained by electro fusion, adsorption and coprecipitation. Electro fused alumina commercially available as abrasive particles was used to produce the pellets by glass sintering. Adsorption and coprecipitation were the methods used to insert metal ions to alumina. The best results were achieved with electro fused alumina and Tm{sup 3+} doped Al{sub 2}O{sub 3} pellets. The electro fused alumina-glass pellets show TL and OSL signals and the TL curve has two peaks. Its minimum detectable radiation dose is 7.2 mGy and the linearity of TL response as function of dose is up to about 800 mGy. The {alpha}-Al{sub 2}O{sub 3}:Tm pellets produced by sintering at 1550 deg C presented a meaningful TL glow curve so that it is worth studying their properties and viability of use in dosimetry. (author)

  16. Mechanical properties of rubberwood oriented strand lumber (OSL: The effect of strand length

    Directory of Open Access Journals (Sweden)

    Buhnnum Kyokong

    2005-09-01

    Full Text Available Effect of strand length on mechanical properties (tension, compression and bending of oriented strand lumber (OSL made of rubberwood (Hevea brasiliensis Muell. Arg. was reported. Three strand lengths of 50 mm, 100 mm, and 150 mm with 1 mm thickness and 15 mm width were used. The strands were mixed with 5% pMDI glue (weight basis in a tumble mixer. The OSL specimens were formed by hot pressing process of unidirectionally aligned strands. Average specific gravity and moisture content were 0.76 and 8.34%, respectively. Tension and compression tests were carried out for directions both parallel and perpendicular to grain while bending test was performed only in parallel direction. Ultimate stresses and moduli of elasticity were examined from the stress-strain curves. It was found that for the parallel-to-grain direction, the longer strand OSL gave higher strength. The role of the strand length did not appear for the direction normal to the grain. The relationship between the mechanical properties of OSL and strand length was well described by the modified Hankinson formula.

  17. OSL dating of sediments from Negro and Solimões rivers – Amazon, Brazil

    International Nuclear Information System (INIS)

    Fiore, M.; Soares, E.A.A.; Mittani, J.C.R.; Yee, M.; Tatumi, S.H.

    2014-01-01

    In this work, the OSL dating results of Quaternary fluvial deposits from the confluence of Negro and Solimões rivers were studied. The equivalent doses (D e ) of sediments were obtained using a Single Aliquot Regeneration (SAR) protocol. Statistic studies were made using frequency histogram, weighted histogram and Radial plot in order to analyze the D e fluctuations. Ages from 74.5 to 205 thousand of years (Pleistocene) were recorded. The gamma-ray spectroscopy was used to evaluate the natural radioisotopes concentrations of the samples and low concentrations were found with values between 0.64 and 3.71 ppm for 235 U and 238 U; 2.01–9.77 ppm for 232 Th; already, for 40 K, the concentration was negligible. The OSL dating of sediments has contributed to a better understanding of the evolution of Negro and Solimões rivers, in Amazon, Brazil. - Highlights: ► OSL dating of fluvial terraces from Amazon. ► SAR protocols applied to Amazon sediments dating. ► OSL dating of Solimão and Negro rivers sediments

  18. TL/OSL ages from Salto Formation (Uruguay)tectonic, climatic and environmental considerations

    International Nuclear Information System (INIS)

    Ubilla, M.; Veroslavsky, G.

    2004-01-01

    TL/OSL ages from Salto Formation based on two sandy samples collected at Salto City and Route 3 (Boycua Creek) are provided: 986±100 ky (LVD-948) and 830±95 ky (LVD-949) respectively. Both support a Pleistocene age for Salto Formation, approximately late early/early middle Pleistocene. Neotectonic and climatic processes are also discussed [es

  19. Application of the OSL dosimetry technique in the identification of irradiated foods, such as condiments and spices

    International Nuclear Information System (INIS)

    Silva, Catherine C.O.; Alencar, Marcus A.V. de

    2013-01-01

    The use of ionizing radiation in food preservation is considered a well-established technique, so many countries, including Brazil, now allow the use of irradiated foods. Many methods have been tested for dosimetry and identification of irradiated foods including thermoluminescence, electron paramagnetic resonance, and others based on microbiological changes and in viscosity, and which requires a sample processing. The technique of optically stimulated luminescence (OSL) presents an advantage over other methods mentioned: The samples may be used without the need for a prior processing. This work aims to study the OSL properties of condiments and spices irradiated, in order to verify the possibility of the application of the OSL technique in identifying and dosimetry of irradiated foods. The samples used were of four kinds of spices: cumin, oregano, white pepper and black pepper. All samples were subjected to gamma irradiation from a Co-60 source with dose values of kerma in air of 100 Gy to 35 kGy. The samples of cumin presents the OSL signal, however, is only possible to identify whether the condiment was irradiated or not. The sample of oregano also presents the OSL signal, and for this condiment is possible to identify addition to its irradiation, the value of dose. The black pepper and white pepper samples don't presents the OSL signal. The results obtained in this study indicate the possibility of using the OSL technique for the identification and dosimetry of irradiated foods. (author)

  20. Pulse and integral optically stimulated luminescence (OSL). Similarities and dissimilarities to thermoluminescence (TL) dose dependence and dose-rate effects

    International Nuclear Information System (INIS)

    Chen, R.; Leung, P.L.

    2000-01-01

    Optically stimulated luminescence (OSL) and thermoluminescence (Tl) are two possible methods to monitor the absorbed radiation in solid samples, and therefore are utilized for dosimetry. For this application, two properties are desirable, namely, linear dose dependence of the measured quantity and dose-rate independence. For Tl, different kinds of super linear dose dependence have been reported in the literature in different materials, and in some cases, dose-rate dependence has also been found. These have been explained as being the result of competition. In OSL, some recent works reported on super linear dose dependence in annealed samples. In the present work, we explain the possible occurrence of these phenomena in OSL by solving numerically the relevant rate equations governing the process during irradiation, relaxation and read-out (heating or light stimulation). The results show that for short pulse OSL, quadratic dose dependence can be expected when only one trapping state and one kind of recombination center are involved and when the excitation starts with empty traps and centers. With the short pulse OSL, the calculation also reveals a possible dose-rate effect. Under the same circumstances, the area under the OSL curve depends linearly on the dose. The dependence of the whole area under the OSL curve on the dose is shown to be super linear when a disconnected trapping state or radiationless center take part in the process. Also, dose-rate effect can be expected in these cases, although no experimental effect of this sort has been reported so far. In pulse OSL, the analogy is made between the measured intensity and the initial rise range of non-first order Tl, whereas for the total area OSL, there is a nearly full analogy with the dose behavior of the Tl maximum. (Author)

  1. Tl and OSL dosimetry of diamond films CVD pure and unpurified with boron-carbon

    International Nuclear Information System (INIS)

    Melendrez, R.; Pedroza M, M.; Chernov, V.; Ochoa N, J.D.; Bernal, R.; Barboza F, M.; Castaneda, B.; Goncalves, J.A.N.; Sandonato, G.M.; Cruz Z, E.; Preciado F, S.; Cruz V, C.; Brown, F.; Schreck, M.

    2004-01-01

    The diamond is a material that possesses extreme physical properties, such as its hardness to the radiation, its low chemical reactivity besides its equivalence to the human tissue, which qualify him as an ideal material for radiation dosimetry. In this work, it was studied the thermal and optically stimulated response (Tl and OSL) of polycrystalline diamond films grown by the technique of CVD pure and contaminated with Boron-carbon (B/C) with the intention of characterizing their efficiency like a dosemeter for radiation in a range of 0 - 3000 Gy. For the case of the films without impurities, the Tl curve presents four main peaks, two of them in an interval of temperatures of 150-200 C and other two additional around of 250-400 C. The dependence of the response of integrated Tl and that of OSL always maintained a lineal relationship with the exhibition dose up to 100 Gy. The behavior of the films contaminated with B/C (2000 - 20000 ppm) was established through experiments that involved the signal of OSL and their relationship with the Tl response. It was found that this processes are correlated, since the electrons caught in the traps of low temperature (50 - 250 C) of the Tl they are the electrons that recombining with more probability to provide the signal of OSL. According to these results it is possible to propose the diamond films as a good candidate for dosimetry to, using the traditional technique of Tl so much as well as the but recent of OSL. (Author)

  2. Comparative analysis of quality assurance systems which effectively control, review and verify the quality of components manufactured for liquid metal cooled fast breeder reactors within the EEC

    International Nuclear Information System (INIS)

    Benn, L.A.

    1985-01-01

    Comparative analyses are made of Quality Assurance Systems, by techniques and the methodology used, for the manufacture of component parts for the Liquid Metal Cooled Fast Breeder Reactor (LMFBR) within the EEC. Two differing alternative systems are presented in the analysis. First, a tabulated analytical treatment which analyses 14 codes and standards relating to Quality Assurance which can be applied to LMFBR's. The comparison equates equivalent clauses between codes and standards followed by an analysis of individual clauses in tabular form, the International Standard ISO 6215. A statistical summary and recommendations conclude this analysis. The second alternative system used in the comparison is a descriptive analytical method applied to 9 selected codes and standards relating to Quality Assurance based on the 13 criteria of the International IAEA Code of Practice no. 50 C.QA entitled ''Quality Assurance for Safety in Nuclear Power Plants''. An investigation is then made of the state of the art on the subject of classification of component parts bearing generally on Quality Assurance. The method of classification is segregated into General, Safety and Inspection categories. A summary of destructive and non destructive controls that may be applied during the manufacture of LMFBR components is given, together with tests that may be applied to selected components, namely Primary Tank, Secondary Sodium Pump and the Primary Cold Trap allocated to Safety Classes, 1, 2 and 3 respectively. The report concludes with a summary of typical records produced at the delivery of a component

  3. Fast component placement with optimized long-stroke passive gravity compensation integrated in a cylindrical/tubular PM actuator

    NARCIS (Netherlands)

    Paulides, J.J.H.; Encica, L.; Meessen, K.J.; Lomonova, E.A.

    2013-01-01

    Applications such as vibration isolation, gravity compensation, pick-and-place machines, etc., would benefit from (long-stroke) cylindrical/tubular permanent magnet (PM) actuators with integrated passive gravity compensation to minimize the power consumption. As an example, in component placing

  4. Fiber optic based OSL set up for online and offline measurements of dose due to ionizing radiation

    International Nuclear Information System (INIS)

    Rawat, N.S.; Kulkarni, M.S.; Upadhyay, B.N.; Srikanth, G.; Bindra, K.S.; Oak, S.M.

    2016-01-01

    An optic-fiber dosimetry system based on optically stimulated luminescence (OSL) and radio-luminescence (RL) from Al_2O_3 : C single-crystal (detector) was designed and developed. The set up is intended to measure dose and dose rates at various radiological installations. The Al_2O_3:C single crystal (from Landaeur Inc. USA) was coupled to a fiber optic delivery system and OSL from the detector is stimulated via the optical fiber cable using light from a Nd:YAG laser. OSL and RL signals are later used to predict cumulative dose and dose rates using "6"0Co gamma source. (author)

  5. Ions and electrons thermal effects on the fast-slow mode conversion process in a three components plasma

    International Nuclear Information System (INIS)

    Fidone, I.; Gomberoff, L.

    1977-07-01

    Fast-slow mode conversion in a deuterium plasma with a small amount of hydrogen impurity, for frequencies close to the two-ion hybrid frequency, is investigated. It is shown that while electron thermal effects tend to inhibit the wave conversion process, ion thermal effects tend to restore, qualitatively, the cold plasma properties, favouring therefore, the energy exchange between the two modes. The aforementioned effects are competitive for zetasub(o)sup(e)=1/nsub(parall).vsub(e)>=1. For zetasub(o)sup(e)<=1, electron thermal effects, in particular Landau damping, dominate over ion Larmor radius effects, drastically diminishing the wave conversion efficacy. For zetasub(o)sup(e)<<1, the coupling between the modes disappears altogether

  6. Fabrication and quality assurance of some important components and sub-assemblies for Prototype Fast Breeder Reactor (PFBR) project

    International Nuclear Information System (INIS)

    Dutta, N.G.; More, S.S.

    2010-01-01

    Bharatiya Nabhikiya Vidyut Nigam (BHAVINI) is engaged in construction of 500 MWe prototype fast breeder reactor (PFBR) at Kalpakkam, Chennai. In this very important and prestigious national programmed M/s Kay Bouvet Engg. Pvt. Ltd. (M/s KBEPL) Satara is contributing in a major way by supplying many important sub-assemblies. M/s KBEPL is engaged in manufacturing, quality assurance and supply of many subassemblies of PFBR like under water trolley (UWT), shielding door, container and container storage rack (CSR), vessel in fuel transfer cell (FTC), personnel air lock (PAL), emergency air lock (EAL) and material air lock (MAL), absorber rod drive mechanism (ARDM) flask assembly and carriage in MAL etc. Two partition doors and four nos. of embedded parts (SS 304L) have already been supplied to Bhavini. The paper deals with manufacturing and Q.A. activities being carried out for supply of these important assemblies to PFBR projects. (author)

  7. Comparison of single-grain and small-aliquot OSL dose estimates in < 3000 years old river sediments from South India

    DEFF Research Database (Denmark)

    Thomas, P.J.; Jain, M.; Juyal, N.

    2005-01-01

    We report on OSL dose distributions derived from small-aliquot and single grains of quartz in young fluvial sediments sampled from the Penner River basin, South India. The single-grain dose distributions suggest that 13 out of 19 samples were well bleached. In many well-bleached samples, there wa......We report on OSL dose distributions derived from small-aliquot and single grains of quartz in young fluvial sediments sampled from the Penner River basin, South India. The single-grain dose distributions suggest that 13 out of 19 samples were well bleached. In many well-bleached samples......, there was an underestimation in the single-aliquot dose estimates as compared to those from the single grain-the difference between average dose estimates determined by the two methods ranged from similar to 1% to 31%. Such a dose underestimation was not detectable in poorly bleached samples. Various possible reasons...... perhaps be one of the reasons; this may occur because the stimulation wavelength affects the proportion of the medium and slow components in the initial signal. (c) 2004 Elsevier Ltd. All rights reserved....

  8. TL and OSL studies on lithium borate single crystals doped with Cu and Ag

    International Nuclear Information System (INIS)

    Rawat, N.S.; Kulkarni, M.S.; Tyagi, M.; Ratna, P.; Mishra, D.R.; Singh, S.G.; Tiwari, B.; Soni, A.; Gadkari, S.C.; Gupta, S.K.

    2012-01-01

    Lithium borate (LBO) single crystals doped with Cu and Ag (0.25 mol% each) (Li 2 B 4 O 7 :Cu,Ag) are grown by the Czochralski method. The thermoluminescence readout on Li 2 B 4 O 7 :Cu,Ag crystals showed three glow peaks at∼375, 441 and 516 K for the heating rate of 1 K/s. The thermoluminescence sensitivity of the grown Li 2 B 4 O 7 :Cu,Ag single crystals is found to be 5 times TLD-100 and a linear dose response in the range 1 mGy to 1 kGy. The glow curve deconvolution reveals nearly first order kinetics for all the three peaks with trap depths 0.77, 1.25 and 1.34 eV respectively and corresponding frequency factors 1.6×10 9 , 1.3×10 13 and 6.8×10 11 s −1 . The continuous wave optically stimulated luminescence (CW-OSL) measurements were performed on the LBO:Cu,Ag single crystals using blue light stimulation. The traps responsible for the three thermoluminescence peaks in Li 2 B 4 O 7 :Cu,Ag are found to be OSL sensitive. The qualitative correlation between TL peaks and CW-OSL response is established. The photoluminescence studies show that in case of co-doping of Ag in LBO:Cu the emission at 370 nm in Cu states dominates over the transitions in Ag states implying doping of Ag plays a role as sensitizer when co-doped with Cu and increases overall emission. - Highlights: ► Growth of crack free single crystals of Li2B4O7 :Cu and Ag. ► Study of TL and OSL parameters for Li2B4O7 :Cu and Ag. ► Correlation of OSL with TL peaks. ► Optimization of OSL readout time with respect to residual TL.

  9. A comparison of single and multiple aliquot TT-OSL data sets for sand-sized quartz from the Arabian Peninsula

    International Nuclear Information System (INIS)

    Rosenberg, T.M.; Preusser, F.; Wintle, A.G.

    2011-01-01

    The quartz OSL signal from dune sands from Saudi Arabia and Oman start to saturate at doses of about 100 Gy. In order to try to date dune sands with greater expected doses, a previously published, single-aliquot, regenerative-dose protocol (SAR) for thermally-transferred optically stimulated luminescence (TT-OSL) was tested. Dose recovery tests, recycling and recuperation ratios showed robust functioning and dose response curves demonstrated the potential to extend the dose range to beyond 600 Gy. Multiple aliquot additive dose (MAAD) TT-OSL protocols were used to test for sensitivity changes in the SAR TT-OSL protocol up to doses of 1200 Gy. A strong dose dependent deviation of the SAR TT-OSL relative to the MAAD TT-OSL dose response is observed. Comparison of the TT-OSL and OSL sensitivity data obtained from the MAAD and SAR data sets shows a lack of proportionality between TT-OSL and OSL for the SAR data which will result in a problem when SAR dose response curves are constructed using many regeneration points with doses above 300 Gy.

  10. Conversion of cresols and naphthalene in the hydroprocessing of three-component model mixtures simulating fast pyrolysis tars

    Energy Technology Data Exchange (ETDEWEB)

    Wandas, R.; Surygala, J.; Sliwka, E. [Technical University of Wroclaw, Wroclaw (Poland). Inst. of Chemistry and Technology of Petroleum and Coal

    1996-05-01

    The hydroconversion of o-, m- and p-cresols in three-component model mixtures with naphthalene and n-hexadecane was investigated over a CoMo/Al{sub 2}O{sub 3} catalyst at 360{degree}C, a hydrogen pressure of 7 MPa and a reaction time of 60 min. The results were compared with those obtained for cresols and naphthalene as single model compounds. A lower efficiency of cresol hydrodeoxygenation as well as naphthalene hydrogenation in the mixtures was found than in the conversion of the single compounds. Conversion mechanisms of cresols in the mixtures with naphthalene are considerably more complex than for individual components. Beside typical catalytic reactions, they include radical reactions in which tetralin, formed by naphthalene hydrogenation, participates as a labile-hydrogen source. The cresol reaction products in such systems include phenol, xylenols, xylenes and dimethycyclohexanes, i.e. compounds essentially absent in hydroconversion of cresols as single substances. Under the experimental conditions, the hydrodeoxygenation efficiency of the cresol isomers decreases in the sequence: para {gt} metal {gt} ortho. 22 refs., 3 figs., 3 tabs.

  11. Detection of sub micro Gray dose levels using OSL phosphor LiMgPO_4:Tb,B

    International Nuclear Information System (INIS)

    Rawat, N.S.; Dhabekar, Bhushan; Muthe, K.P.; Koul, D.K.; Datta, D.

    2017-01-01

    Highlights: • LiMgPO4:Tb,B has been studied and shown to possesses minimum measurable dose (MMD) in sub micro Gray region. • MMD as low as 0.49 µGy in readout time of less than 1 s at stimulation intensity of 32 mW/cm"2 has been achieved. • The OSL measurements for low doses has strengthened and validated this claim. • OSL spectrum shows several emission peaks and the prominent peak around 380 nm. - Abstract: Detection of sub micro Gray doses finds application in personnel and environmental monitoring, and nuclear forensics. Recently developed LiMgPO_4:Tb,B (LMP) is highly sensitive Optically Stimulated Luminescence (OSL) phosphor with excellent dosimetric properties. The OSL emission spectrum of LMP consists of several peaks attributed to characteristic Tb"3"+ emission. The OSL emission peak at 380 nm is favorable for bi-alkali PMT used in RISO reader system. It is demonstrated that significant improvement in dose detection threshold can be realized for LMP by optimization of continuous wave (CW–) OSL parameters like stimulation intensity and readout time. The minimum measurable dose (MMD) as low as 0.49 µGy in readout time of less than 1 s at stimulation intensity of 32 mW/cm"2 has been achieved using this phosphor. The recommendations for choice of parameters for personnel and environmental monitoring are also discussed.

  12. Detection of sub micro Gray dose levels using OSL phosphor LiMgPO{sub 4}:Tb,B

    Energy Technology Data Exchange (ETDEWEB)

    Rawat, N.S., E-mail: naru@barc.gov.in [Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Trombay, Mumbai (India); Dhabekar, Bhushan [Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Trombay, Mumbai (India); Muthe, K.P. [Technical Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai (India); Koul, D.K.; Datta, D. [Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Trombay, Mumbai (India)

    2017-04-15

    Highlights: • LiMgPO4:Tb,B has been studied and shown to possesses minimum measurable dose (MMD) in sub micro Gray region. • MMD as low as 0.49 µGy in readout time of less than 1 s at stimulation intensity of 32 mW/cm{sup 2} has been achieved. • The OSL measurements for low doses has strengthened and validated this claim. • OSL spectrum shows several emission peaks and the prominent peak around 380 nm. - Abstract: Detection of sub micro Gray doses finds application in personnel and environmental monitoring, and nuclear forensics. Recently developed LiMgPO{sub 4}:Tb,B (LMP) is highly sensitive Optically Stimulated Luminescence (OSL) phosphor with excellent dosimetric properties. The OSL emission spectrum of LMP consists of several peaks attributed to characteristic Tb{sup 3+} emission. The OSL emission peak at 380 nm is favorable for bi-alkali PMT used in RISO reader system. It is demonstrated that significant improvement in dose detection threshold can be realized for LMP by optimization of continuous wave (CW–) OSL parameters like stimulation intensity and readout time. The minimum measurable dose (MMD) as low as 0.49 µGy in readout time of less than 1 s at stimulation intensity of 32 mW/cm{sup 2} has been achieved using this phosphor. The recommendations for choice of parameters for personnel and environmental monitoring are also discussed.

  13. Quartz OSL dating of late Holocene beach ridges from the Magdalen Islands (Quebec, Canada)

    DEFF Research Database (Denmark)

    Remillard, A.M.; Buylaert, Jan-Pieter; Murray, Andrew

    2015-01-01

    Quartz optically stimulated luminescence (OSL) dating has been applied to sandy beach ridge systems from the Magdalen Islands in the center of the Gulf of St. Lawrence (Quebec, Canada) to provide the first chronological framework for these features. Nineteen beach ridges (22 samples) from four......). The OSL ages indicate that the ridges were built between 2.6 ± 0.2 ka and 0.40 ± 0.10 ka, i.e. during a period of sea level rise. This rise eroded adjacent sandstone cliffs, which contributed a significant sediment supply to the littoral drift and beaches. Some low-lying coasts in the archipelago...... great potential in this area, and is an appropriate method for establishing precise chronologies for coastal sediments in this region of the Gulf of St. Lawrence. © 2015 Elsevier B.V. All rights reserved....

  14. TL, OSL and C-14 dating results of the sediments and bricks from mummified nuns' grave

    International Nuclear Information System (INIS)

    Tudela, Diego R.G.; Tatumi, Sonia H.; Yee, Marcio; Brito, Silvio L.M.

    2012-01-01

    This paper presents the results of TL and OSL dating of soil and fragments of bricks from a grave, which was occupied by two mummified nuns, found at 'Luz' Monastery, located in the state of Sao Paulo, Brazil. The TL and OSL ages were compared to C-14 dating ones obtained from bone collagens of the mummies. The majority of the ages is related to the eighteenth century. The gamma-ray spectroscopy was used to evaluate natural radioisotope concentrations in the samples, and by using these concentrations the annual dose rates, from 3.0 to 5.3 Gy/kyr, were obtained. Neutron activation analysis was performed and the radioisotope contents results are in agreement with those obtained by gamma-ray spectroscopy. The contents of U, Th and Ce elements were higher than those found in usual sediments. (author)

  15. Thermally assisted OSL from deep traps in Al2O3:C

    International Nuclear Information System (INIS)

    Polymeris, G.S.; Raptis, S.; Afouxenidis, D.; Tsirliganis, N.C.; Kitis, G.

    2010-01-01

    The present work suggests an alternative experimental method in order to not only measure the signal of the deep traps in Al 2 O 3 :C without heating the sample to temperatures greater than 500 o C, but also use this signal for high dose level dosimetry purposes as well. This method consists of photo transfer OSL measurements performed at elevated temperatures using the blue LEDs (470 nm, FWHM 20 nm) housed at commercial Riso TL/OSL systems, after the sample was previously heated up to 500 o C in order to empty its main TL dosimetric trap. The influence of this procedure on specific features such as glow curve shape and sensitivity of the main TL glow peak was also studied.

  16. SSDL Preparation for Implementation of the Use of OSL Dosimeters in Malaysia

    International Nuclear Information System (INIS)

    Sangau, J.K.; Taiman Kadni; Ahmad Bazlie Abdul Kadir

    2013-01-01

    Since the early 1980's, film badge has been widely used as a device of personal dose monitoring in Malaysia. Secondary Standard Dosimetry Laboratory (SSDL), as a service center for film badge has obtained the supply of personal monitoring film from Agfa Gevaert, Belgium every year. As the uses of film badge have some weaknesses, it has prompted SSDL to find an alternative dosimeter to replace the film badge. Based on the studies that have been conducted, SSDL has selected OSL dosimeter (Optically Stimulated Luminescent Dosimeter) to replace the film badge and is expected to be fully operational by middle of 2015. This paper aims to explain the selection of OSL dosimeter and planning carried out to ensure the success of their application in Malaysia. (author)

  17. Optically stimulated luminescence (OSL) as a chronometer for surface exposure dating

    DEFF Research Database (Denmark)

    Sohbati, Reza; Murray, Andrew S.; Chapot, Melissa S.

    2012-01-01

    We pioneer a technique of surface-exposure dating based upon the characteristic form of an optically stimulated luminescence (OSL) bleaching profile beneath a rock surface; this evolves as a function of depth and time. As a field illustration of this new method, the maximum age of a premier example...... exposure histories; one of these samples was exposed at the time of sampling and one was buried and no longer light exposed. A third sample is known to have been first exposed 80 years ago and was still exposed at the time of sampling. First, the OSL-depth profile of the known-age sample is modeled...... to estimate material-dependent and environmental parameters. These parameters are then used to fit the model to the corresponding data for the samples of unknown exposure history. From these fits we calculate that the buried sample was light exposed for similar to 700 years before burial and that the unburied...

  18. Two-dimensional chronostratigraphic modelling of OSL ages from recent beach-ridge deposits, SE Australia

    DEFF Research Database (Denmark)

    Tamura, Toru; Cunningham, Alastair C.; Oliver, Thomas S.N.

    2018-01-01

    Optically-stimulated luminesecne (OSL) dating, in concert with two-dimensional ground-penetrating radar (GPR) profiling, has contributed to significant advances in our understanding of beach-ridge systems and other sedimentary landforms in various settings. For recent beach-ridges, the good OSL...... samples may be larger than the difference in sample ages. Age inversions can be avoided, however, if the stratigraphic constraints are included in the age estimation process. Here, we create a custom Bayesian chronological model for a recent (..., for direct comparison with a GPR profile. The model includes a full ‘burial-dose model’ for each sample and a dose rate term with the modelled ages constrained by the vertical and shore-normal sample order. The modelled ages are visualized by plotting isochrones on the beach-ridge cross section...

  19. BeO-OSL detectors for dose measurements in cell cultures

    International Nuclear Information System (INIS)

    Andreeff, M.; Freudenberg, R.; Kotzerke, J.; Sommer, D.; Reichelt, U.; Henniger, J.

    2009-01-01

    Aim: The absorbed dose is an important parameter in experiments involving irradiation of cells in vitro with unsealed radionuclides. Typically, this is estimated with a model calculation, although the results thus obtained cannot be verified. Generally used real-time measurement methods are not applicable in this setting. A new detector material with in vitro suitability is the subject of this work. Methods: Optically-stimulated luminescence (OSL) dosimeters based on beryllium oxide (BeO) were used for dose measurement in cell cultures exposed to unsealed radionuclides. Their qualitative properties (e. g. energy-dependent count rate sensitivity, fading, contamination by radioactive liquids) were determined and compared to the results of a Monte Carlo simulation (using AMOS software). OSL dosimeters were tested in common cell culture setups with a known geometry. Results: Dose reproducibility of the OSL dosimeters was ± 1.5%. Fading at room temperature was 0.07% per day. Dose loss (optically-stimulated deletion) under ambient lighting conditions was 0.5% per minute. The Monte Carlo simulation for the relative sensitivity at different beta energies provided corresponding results to those obtained with the OSL dosimeters. Dose profile measurements using a 6 well plate and 14 ml PP tube showed that the geometry of the cell culture vessel has a marked influence on dose distribution with 188 Re. Conclusion: A new dosimeter system was calibrated with β-emitters of different energy. It turned out as suitable for measuring dose in liquids. The dose profile measurements obtained are suitably precise to be used as a check against theoretical dose calculations. (orig.)

  20. 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.

  1. TL and OSL properties of Mn2+-doped MgGa2O4 phosphor

    Science.gov (United States)

    Luchechko, A.; Zhydachevskyy, Ya; Maraba, D.; Bulur, E.; Ubizskii, S.; Kravets, O.

    2018-04-01

    The oxide MgGa2O4 spinel ceramics doped with Mn2+ ions was synthesized by a solid-state reaction at 1200 °C in air. The activator concentration was equal 0.05 mol% of MnO. Phase purity of the synthesized samples was analyzed by X-ray diffraction technique. This spinel ceramics show efficient green emission in the range from 470 to 550 nm with a maximum at about 505 nm under UV or X-ray excitations, which is due to Mn2+ ions. MgGa2O4: Mn2+ exhibits intense thermoluminescence (TL) and optically stimulated luminescence (OSL) after influence of ionizing radiation. Are complex nature of the TL glow curves is associated with a significant number of structural defects that are responsible for the formation of shallow and deep electron traps. In this work, time-resolved OSL characteristics of the samples exposed to beta particles are reported for the first time. A light from green LED was used for optical stimulation. Obtained TL and OSL results suggest MgGa2O4:Mn2+ as perspective material for further research and possible application in radiation dosimetry.

  2. Dose rate dependence for different dosimeters and detectors: TLD, OSL, EBT films, and diamond detectors

    International Nuclear Information System (INIS)

    Karsch, L.; Beyreuther, E.; Burris-Mog, T.; Kraft, S.; Richter, C.; Zeil, K.; Pawelke, J.

    2012-01-01

    Purpose: The use of laser accelerators in radiation therapy can perhaps increase the low number of proton and ion therapy facilities in some years due to the low investment costs and small size. The laser-based acceleration technology leads to a very high peak dose rate of about 10 11 Gy/s. A first dosimetric task is the evaluation of dose rate dependence of clinical dosimeters and other detectors. Methods: The measurements were done at ELBE, a superconductive linear electron accelerator which generates electron pulses with 5 ps length at 20 MeV. The different dose rates are reached by adjusting the number of electrons in one beam pulse. Three clinical dosimeters (TLD, OSL, and EBT radiochromic films) were irradiated with four different dose rates and nearly the same dose. A faraday cup, an integrating current transformer, and an ionization chamber were used to control the particle flux on the dosimeters. Furthermore two diamond detectors were tested. Results: The dosimeters are dose rate independent up to 410 9 Gy/s within 2% (OSL and TLD) and up to 1510 9 Gy/s within 5% (EBT films). The diamond detectors show strong dose rate dependence. Conclusions: TLD, OSL dosimeters, and EBT films are suitable for pulsed beams with a very high pulse dose rate like laser accelerated particle beams.

  3. 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

  4. JSFR design progress related to development of safety design criteria for generation IV sodium-cooled fast reactors. (3) Progress of component design

    International Nuclear Information System (INIS)

    Enuma, Yasuhiro; Kawasaki, Nobuchika; Orita, Junichi; Eto, Masao; Miyagawa, Takayuki

    2015-01-01

    In the frame work of generation IV international forum (GIF), safety design criteria (SDC) and safety design guideline (SDG) for the generation IV sodium-cooled fast reactors have been developing in the circumstance of worldwide deployment of SFRs. JAEA, JAPC, MFBR have been investigating design study for JSFR to satisfy SDC in the feasibility study of SDG for Sodium-cooled Fast Reactor (SFR). In addition to the safety measures, maintainability, reparability and manufacturability are taken into account in the JSFR design study. This paper describes the design of main components. Enlargement of the access route for the inspection devices and addition of the access routes were carried out for the reactor structure. The pump-integrated IHX (pump/IHX) was modified for the primary heat exchanger (PHX), which was installed for the decay heat removal in the IHX at the upper plenum, to be removable for improved repair and maintenance. For the steam generator (SG), protective wall tube type design is under investigation as an option with less R and D risks. (author)

  5. A fast-fission component with small mass drift in the reaction 84Kr + 27Al at ELab = 5.9 MeV/u

    International Nuclear Information System (INIS)

    Heusch, B.; Freiesleben, H.; Schneider, W.F.W.; Kohlmeyer, B.; Stege, H.; Puehlhofer, F.

    1985-01-01

    All reaction products in the range from target- and projectile-like to fission-like fragments were measured for the system 84 Kr + 27 Al at 5.9 MeV/u beam energy. They are assigned to the various reaction mechanisms on the basis of experimental signatures (energy dissipation, mass and angular distribution). The sum of the measured partial cross sections, including the evaporation residue yield obtained previously, agrees with the total reaction cross section derived from elastic scattering. A small fast-fission component was found, discernible from deep-inelastic reactions by its 1/sinθ angular distribution, and distinguished from compound-nucleus fission by an incomplete mass asymmetry relaxation

  6. A method to acquire CT organ dose map using OSL dosimeters and ATOM anthropomorphic phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Da; Li, Xinhua; Liu, Bob [Division of Diagnostic Imaging Physics and Webster Center for Advanced Research and Education in Radiation, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts 02114 (United States); Gao, Yiming; Xu, X. George [Nuclear Engineering Program, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

    2013-08-15

    Purpose: To present the design and procedure of an experimental method for acquiring densely sampled organ dose map for CT applications, based on optically stimulated luminescence (OSL) dosimeters “nanoDots” and standard ATOM anthropomorphic phantoms; and to provide the results of applying the method—a dose data set with good statistics for the comparison with Monte Carlo simulation result in the future.Methods: A standard ATOM phantom has densely located holes (in 3 × 3 cm or 1.5 × 1.5 cm grids), which are too small (5 mm in diameter) to host many types of dosimeters, including the nanoDots. The authors modified the conventional way in which nanoDots are used, by removing the OSL disks from the holders before inserting them inside a standard ATOM phantom for dose measurements. The authors solved three technical difficulties introduced by this modification: (1) energy dependent dose calibration for raw OSL readings; (2) influence of the brief background exposure of OSL disks to dimmed room light; (3) correct pairing between the dose readings and measurement locations. The authors acquired 100 dose measurements at various positions in the phantom, which was scanned using a clinical chest protocol with both angular and z-axis tube current modulations.Results: Dose calibration was performed according to the beam qualities inside the phantom as determined from an established Monte Carlo model of the scanner. The influence of the brief exposure to dimmed room light was evaluated and deemed negligible. Pairing between the OSL readings and measurement locations was ensured by the experimental design. The organ doses measured for a routine adult chest scan protocol ranged from 9.4 to 18.8 mGy, depending on the composition, location, and surrounding anatomy of the organs. The dose distribution across different slices of the phantom strongly depended on the z-axis mA modulation. In the same slice, doses to the soft tissues other than the spinal cord demonstrated

  7. A method to acquire CT organ dose map using OSL dosimeters and ATOM anthropomorphic phantoms

    International Nuclear Information System (INIS)

    Zhang, Da; Li, Xinhua; Liu, Bob; Gao, Yiming; Xu, X. George

    2013-01-01

    Purpose: To present the design and procedure of an experimental method for acquiring densely sampled organ dose map for CT applications, based on optically stimulated luminescence (OSL) dosimeters “nanoDots” and standard ATOM anthropomorphic phantoms; and to provide the results of applying the method—a dose data set with good statistics for the comparison with Monte Carlo simulation result in the future.Methods: A standard ATOM phantom has densely located holes (in 3 × 3 cm or 1.5 × 1.5 cm grids), which are too small (5 mm in diameter) to host many types of dosimeters, including the nanoDots. The authors modified the conventional way in which nanoDots are used, by removing the OSL disks from the holders before inserting them inside a standard ATOM phantom for dose measurements. The authors solved three technical difficulties introduced by this modification: (1) energy dependent dose calibration for raw OSL readings; (2) influence of the brief background exposure of OSL disks to dimmed room light; (3) correct pairing between the dose readings and measurement locations. The authors acquired 100 dose measurements at various positions in the phantom, which was scanned using a clinical chest protocol with both angular and z-axis tube current modulations.Results: Dose calibration was performed according to the beam qualities inside the phantom as determined from an established Monte Carlo model of the scanner. The influence of the brief exposure to dimmed room light was evaluated and deemed negligible. Pairing between the OSL readings and measurement locations was ensured by the experimental design. The organ doses measured for a routine adult chest scan protocol ranged from 9.4 to 18.8 mGy, depending on the composition, location, and surrounding anatomy of the organs. The dose distribution across different slices of the phantom strongly depended on the z-axis mA modulation. In the same slice, doses to the soft tissues other than the spinal cord demonstrated

  8. A Fast and Sensitive New Satellite SO2 Retrieval Algorithm based on Principal Component Analysis: Application to the Ozone Monitoring Instrument

    Science.gov (United States)

    Li, Can; Joiner, Joanna; Krotkov, A.; Bhartia, Pawan K.

    2013-01-01

    We describe a new algorithm to retrieve SO2 from satellite-measured hyperspectral radiances. We employ the principal component analysis technique in regions with no significant SO2 to capture radiance variability caused by both physical processes (e.g., Rayleigh and Raman scattering and ozone absorption) and measurement artifacts. We use the resulting principal components and SO2 Jacobians calculated with a radiative transfer model to directly estimate SO2 vertical column density in one step. Application to the Ozone Monitoring Instrument (OMI) radiance spectra in 310.5-340 nm demonstrates that this approach can greatly reduce biases in the operational OMI product and decrease the noise by a factor of 2, providing greater sensitivity to anthropogenic emissions. The new algorithm is fast, eliminates the need for instrument-specific radiance correction schemes, and can be easily adapted to other sensors. These attributes make it a promising technique for producing longterm, consistent SO2 records for air quality and climate research.

  9. Quartz OSL Dating of the loess deposit in the eastern Tibetan Plateau and its environment implications since the Last Glaciation

    Science.gov (United States)

    Yang, S.; Cheng, T.; Liu, W.; Fang, X.

    2017-12-01

    Loess deposit is widespread in the Chuanxi Plateau, the eastern Tibetan Plateau, which is a critical archive for understanding the aeolian process, the evolution of the westerly and the environment changes on the Plateau. Previous studies have shown its aeolian origin, and mainly transported by wind from the western part of the Tibetan Plateau. However, the aeolian processes of the loess and its environment implications are not well understood mainly due to lack of detailed age controls. We carry out a combined quartz optically stimulated luminescence (OSL) dating and accelerator mass spectrometry radiocarbon dating (AMS 14-C) for the loess deposits in Garzê and Jinchuan. The results indicate that the quartz OSL dating can provide reliable age controls for the loess-paleosol sequences from the Chuanxi Plateau, showing the potential of OSL to date loess in the high altitude region. The results indicate that the OSL ages are in agreement with the observed stratigraphy in the field. The constructed OSL and AMS 14-C chronology of the Garzê loess reveals that the widespread loess in Ganzi Region deposited since the Last Glacial. The dust accumulation is rapid during marine isotope stage (MIS) 3 and 2, and a relative low accumulation rate in the Holocene, which may related with the desertification processes of the inner Tibetan Plateau.

  10. A fiber-dosimetry method based on OSL from Al2O3:C for radiotherapy applications

    International Nuclear Information System (INIS)

    Gaza, R.; McKeever, S.W.S.; Akselrod, M.S.; Akselrod, A.; Underwood, T.; Yoder, C.; Andersen, C.E.; Aznar, M.C.; Marckmann, C.J.; Boetter-Jensen, L.

    2004-01-01

    We describe a high-sensitivity, fiber-optic dosimetry system based on optically stimulated luminescence (OSL) and radioluminescence from Al 2 O 3 :C single-crystal fibers (detectors). The detectors are coupled to a fiber optic delivery system and OSL from the detector is stimulated via the optical fiber cable using light from a Nd:YAG laser. The OSL is guided back along the same fiber and is detected by a photomultiplier tube. The Al 2 O 3 :C detectors are small and demonstrate high sensitivity with a large signal-to-noise ratio. We describe two modes of operation of the system and discuss algorithms that provide accurate estimation of dose rate and integrated dose in near real time. The system is free from magnetic and electrical interference, and is designed for use in several forms of radiotherapy, including in vitro brachytherapy source calibration, and in vivo dosimetry during patient treatment

  11. TL-OSL study of Li{sub 3}PO{sub 4}: Mg, Cu phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Rahangdale, S. R., E-mail: sachin.rahangdale1@gmail.com; Wankhede, S. P. [Department of Physics, K.D.K.College of Engineering, Nagpur (India); Dhabekar, B. S. [RPAD, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Palikundwar, U. A.; Moharil, S. V. [Department of Physics, RTM Nagpur University, Nagpur, 440010 (India)

    2015-08-28

    In the present work, we report the thermoluminescence and optically stimulated luminescence properties of Mg and Cu doped Li{sub 3}PO{sub 4} phosphor. The phosphor was synthesized by precipitation method. The thermoluminescence dosimetric peak temperature for the phosphor varies with concentrations of Mg and Cu. Li{sub 3}PO{sub 4} shows good response to 470nm optical stimulation. The OSL sensitivity of the phosphor is approximately 12 times than that of standard Lithium magnesium phosphate. This study may help to develop this material for the application in real time dosimetry using optically stimulated luminescence.

  12. Constraining Middle Pleistocene Glaciations in Birmingham, England; Using Optical Stimulated Luminescence (OSL) Dating.

    Science.gov (United States)

    Gibson, S. M.; Gibbard, P. L.; Bateman, M. D.; Boreham, S.

    2014-12-01

    Birmingham is built on a complex sequence of Middle Pleistocene sediments, representing at least three lowland glaciations (MIS12, MIS6, and MIS2). British Geological Survey mapping accounts 75% of the land mass as Quaternary deposits; predominantly glacial-sandy tills, glacial-fluvial sands, clays and organic silts and peats. Understanding the age of fluvial-glacial outwash, related to specific glaciations, is critical in establishing a Geochronology of Birmingham. Shotton (1953) found a series of Middle Pleistocene glacial sediments, termed the Wolstonian, intermediate in age between MIS11 and MIS5e Interglacial's. Uncertainty surrounding the relation to East Anglian sequences developed by Rose (1987) implies Birmingham sequences should be referred to MIS12. Despite this, younger Middle Pleistocene glacial sequences occur in Birmingham, yet uncertainty has deepened over our understanding of the complex, inaccessible sediments, especially as deposits have similar extent with MIS2 sequences. Five Optical Stimulated Luminescence (OSL) dates from three sites around Birmingham have been sampled. East of Birmingham, ice advanced from the Irish Sea and later the North East. In Wolston, a sample of outwash sand, associated with the Thurssington Till, is dated. In Meriden, two samples of outwash sands, associated with a distal Oadby Till, are dated. West of Birmingham, ice advanced from the Welsh Ice Sheet. In Seisdon, two samples of an Esker and outwash sand, associated with a Ridgeacre Till, are dated. Correlation of OSL dates provide an important constraint on understanding the history of Birmingham. Using GSI3D modeling to correlate geochronology and sedimentology, the significance of OSL dating can be understood within the complex sequences (and regional stratigraphy), complimented by Cosmogenic and Palynology dates taken in South West and North East. OSL dating on Birmingham's outwash sands, deposited by extensive repeated Middle Pleistocene glaciations, asserts the

  13. TL, OSL and C-14 dating results of the sediments and bricks from mummified nuns' grave

    Directory of Open Access Journals (Sweden)

    Diego R.G. Tudela

    2012-06-01

    Full Text Available This paper presents the results of TL and OSL dating of soil and fragments of bricks from a grave, which was occupied by two mummified nuns, found at "Luz" Monastery, located in the state of São Paulo, Brazil. The TL and OSL ages were compared to C-14 dating ones obtained from bone collagens of the mummies. The majority of the ages is related to the eighteenth century. The gamma-ray spectroscopy was used to evaluate natural radioisotope concentrations in the samples, and by using these concentrations the annual dose rates, from 3.0 to 5.3 Gy/kyr, were obtained. Neutron activation analysis was performed and the radioisotope contents results are in agreement with those obtained by gamma-ray spectroscopy. The contents of U, Th and Ce elements were higher than those found in usual sediments.Este artigo apresenta os resultados de datação por TL e OSL de solos, e fragmentos de tijolos de um túmulo, que foi ocupado por duas freiras mumificadas encontradas no Mosteiro da "Luz", localizado no Estado de São Paulo, Brasil. As idades encontradas por TL e OSL foram comparadas às obtidas a partir de C-14 dos colágenos contidos em amostras de osso das múmias. A maioria das idades obtidas são do século XVIII. A espectroscopia de radiação-gama foi utilizada para avaliar concentrações de radioisótopos naturais nas amostras e para calcular as taxas de dose anual que resultaram em 3,0 a 5,3 Gy/kano. As concentrações radioativas são próximas daquelas obtidas através de Análise por Ativação de Nêutrons. Os conteúdos de elementos U, Th e Ce são superiores aos encontrados na maioria dos sedimentos.

  14. SU-E-T-592: OSL Response of Al2O3:C Detectors Exposed to Therapeutic Proton Beams

    Energy Technology Data Exchange (ETDEWEB)

    Granville, DA [Carleton Laboratory for Radiotherapy Physics, Carleton University, Ottawa, ON (Canada); Flint, DB; Sawakuchi, GO [The University of Texas MD Anderson Cancer Center, Houston, TX (United States)

    2015-06-15

    Purpose: To characterize the response of Al{sub 2}O{sub 3}:C optically stimulated luminescence (OSL) detectors (OSLDs) exposed to therapeutic proton beams of differing beam quality. Methods: We prepared Al{sub 2}O{sub 3}:C OSLDs from the same material as commercially available nanoDot dosimeters (Landauer, Inc). We irradiated the OSLDs in modulated proton beams of varying quality, as defined by the residual range. An absorbed dose to water of 0.2 Gy was delivered to all OSLDs with the residual range values varying from 0.5 to 23.5 cm (average LET in water from ∼0.5 to 2.5 keV/µm). To investigate the beam quality dependence of different emission bands within the OSL spectrum, we performed OSLD readouts using both continuous-wave stimulation (CW-OSL) and pulsed stimulation (P-OSL) with two sets of optical filters (Hoya U-340 and Kopp 5113). For all readout modes, the relative absorbed dose sensitivity (S{sub rel}) for each beam quality was calculated using OSLDs irradiated in a 6 MV photon beam as a reference. Results: We found that the relative absorbed dose sensitivity was highly dependent on both readout mode and integration time of the OSL signal. For CW-OSL signals containing only the blue emission band, S{sub rel} was between 0.85 and 0.94 for 1 s readouts and between 0.82 and 0.93 for 10 s readouts. Similarly, for P-OSL readouts containing only the blue emission band S{sub rel} ranged from 0.86 to 0.91, and 0.82 to 0.93 for 1 s and 10 s readouts, respectively. For OSLD signals containing only the UV emission band, S{sub rel} ranged from 1.00 to 1.46, and 0.97 to 1.30 for P-OSL readouts of 1 s and 10 s, respectively. Conclusion: For measurements of absorbed dose using Al{sub 2}O{sub 3}:C OSLDs in therapeutic proton beams, dependence on beam quality was smallest for readout protocols that selected the blue emission band with small integration times. DA Granville received financial support from the Natural Sciences and Engineering

  15. Single-grain quartz OSL dating of debris flow deposits from Men Tou Gou, south west Beijing, China

    DEFF Research Database (Denmark)

    Zhao, Qiuyue; Thomsen, Kristina Jørkov; Murray, A. S.

    2017-01-01

    of the return frequency of these debris flows, risk assessment and climate change research. In this project, we use quartz single-grain optically stimulated luminescence (OSL) methods to determine the burial ages of five debris flow samples from the Zhai Tang region -60 km west of Beijing. OSL characteristics...... poorly bleached prior to deposition; relative over-dispersions are larger than 60%. Minimum age modelling indicates that all five samples were deposited within the past few hundred years, indicating that catastrophic debris flows are occurring under the historically-recent land-use pattern....

  16. Quaternary alluvial fans of Ciudad Juárez, Chihuahua, northern México: OSL ages and implications for climatic history of the region

    Science.gov (United States)

    Zúñiga de León, David; Kershaw, Stephen; Mahan, Shannon

    2016-01-01

    Alluvial fans formed from sediments derived from erosion of the Juárez Mountains in northernmost México have a significant flood impact on the Ciudad Juárez, which is built on the fan system. The northern part of Ciudad Juárez is the most active; further south, older parts of the fan, upon which the rest of the city is built, were largely eroded by natural processes prior to human habitation and subsequently modified only recently by human construction. Three aeolian sand samples, collected from the uppermost (youngest) parts of the fan system in the city area, in places where human intervention has not disturbed the sediment, and constrain the latest dates of fan building. Depositional ages of the Quaternary alluvial fans were measured using Optically Stimulated Luminescence (OSL) on aeolian sands that have inter-fingered with alluvial fan material. These dates are: a) sample P1, 31 ka; b) sample P2, 41 ka; c) sample P3, 74 ka, between Oxygen Isotope Stages (OIS) 3 to 5. They demonstrate that fan development, in the area now occupied by the city, terminated in the Late Pleistocene, immediately after what we interpret to have been an extended period of erosion without further deposition, lasting from the Late Pleistocene to Holocene. The three dates broadly correspond to global glacial periods, implying that the cool, dry periods may reflect periods of aeolian transport in northern México in between phases that were wetter to form the alluvial fans. Alluvial fan margins inter-finger with fluvial terrace sediments derived from the Río Bravo, indicating an additional component of fan dissection by Río Bravo lateral erosion, presumed to be active during earlier times than our OSL ages, but these are not yet dated. Further dating is required to ascertain the controls on the fan and fluvial system.

  17. Investigation of OSL signal of resistors from mobile phones for accidental dosimetry

    International Nuclear Information System (INIS)

    Mrozik, A.; Marczewska, B.; Bilski, P.; Gieszczyk, W.

    2014-01-01

    Resistors from mobile phones, usually located near the human body, are considered as individual dosimeters of ionizing radiation in emergency situations. The resistors contain Al 2 O 3 , which is optically stimulated luminescence (OSL) material sensitive to ionizing radiation. This work is focused on determination of dose homogeneity within mobile phones which was carried out by OSL measurements of resistors placed in different parts inside the mobile phone. Separate, commercially available resistors, similar in the shape and size to the resistors from circuit board of the studied mobile phone, were situated in different locations inside it. The irradiations were performed in uniform 60 Co and 137 Cs radiation fields, with the mobile phones connected and not connected to the cellular network. The dose decrease of 9% was measured for original resistors situated between circuit board and battery, in comparison to the dose at the front of the phone. The resistors showed the lower signal when the mobile phone was connected to the cellular network, due to higher temperature inside the housing. The profile of fading was investigated within 3 month period for resistors irradiated with 1 Gy of gamma rays to estimate of the fading coefficient. - Highlights: • Impact of a mobile phone mode (switched on/off) on absorbed dose by resistors was showed. • The influence of the temperature during irradiation on absorbed dose was measured. • Dose distribution inside of a mobile phone was performed. • Fading factor of resistors was calculated

  18. Sources of uncertainty in individual monitoring for photographic,TL and OSL dosimetry techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Max S.; Silva, Everton R.; Mauricio, Claudia L.P., E-mail: max.das.ferreira@gmail.com, E-mail: everton@ird.gov.br, E-mail: claudia@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The identification of the uncertainty sources and their quantification is essential to the quality of any dosimetric results. If uncertainties are not stated for all dose measurements informed in the monthly dose report to the monitored radiation facilities, they need to be known. This study aims to analyze the influence of different sources of uncertainties associated with photographic, TL and OSL dosimetric techniques, considering the evaluation of occupational doses of whole-body exposure for photons. To identify the sources of uncertainty it was conducted a bibliographic review in specific documents that deal with operational aspects of each technique and the uncertainties associated to each of them. Withal, technical visits to individual monitoring services were conducted to assist in this identification. The sources of uncertainty were categorized and their contributions were expressed in a qualitative way. The process of calibration and traceability are the most important sources of uncertainties, regardless the technique used. For photographic dosimetry, the remaining important uncertainty sources are due to: energy and angular dependence; linearity of response; variations in the films processing. For TL and OSL, the key process for a good performance is respectively the reproducibility of the thermal and optical cycles. For the three techniques, all procedures of the measurement process must be standardized, controlled and reproducible. Further studies can be performed to quantify the contribution of the sources of uncertainty. (author)

  19. Tl and OSL dosimetry of diamond films CVD pure and unpurified with boron-carbon; Dosimetria Tl y OSL de peliculas de diamante CVD puras e impurificadas con boro-carbono

    Energy Technology Data Exchange (ETDEWEB)

    Melendrez, R.; Pedroza M, M.; Chernov, V.; Ochoa N, J.D.; Bernal, R.; Barboza F, M. [CIF, UNISON, A.P. 5-088, 83190 Hermosillo, Sonora (Mexico); Castaneda, B. [Departamento de Fisica, Universidad de Sonora, Apdo. Postal 1626, Hermosillo, Sonora (Mexico); Goncalves, J.A.N.; Sandonato, G.M. [Laboratorio Associado de Plasma, Instituto Nacional de Pesquisas Espaciais C.P. 515- 12201 -970, Sao Jose dos Campos, SP (Brazil); Cruz Z, E. [Instituto de Ciencias Nucleares, UNAM, Apdo. Postal 70-543, 04510 Mexico D.F. (Mexico); Preciado F, S.; Cruz V, C.; Brown, F. [Departamento de Investigacion en Polimeros y Materiales de la Universidad de Sonora, Apdo. Postal 130, 83000 Hermosillo, Sonora (Mexico); Schreck, M. [Universitaet Augsburg, Institut fuer Physik D-86135 Augsburg (Germany)

    2004-07-01

    The diamond is a material that possesses extreme physical properties, such as its hardness to the radiation, its low chemical reactivity besides its equivalence to the human tissue, which qualify him as an ideal material for radiation dosimetry. In this work, it was studied the thermal and optically stimulated response (Tl and OSL) of polycrystalline diamond films grown by the technique of CVD pure and contaminated with Boron-carbon (B/C) with the intention of characterizing their efficiency like a dosemeter for radiation in a range of 0 - 3000 Gy. For the case of the films without impurities, the Tl curve presents four main peaks, two of them in an interval of temperatures of 150-200 C and other two additional around of 250-400 C. The dependence of the response of integrated Tl and that of OSL always maintained a lineal relationship with the exhibition dose up to 100 Gy. The behavior of the films contaminated with B/C (2000 - 20000 ppm) was established through experiments that involved the signal of OSL and their relationship with the Tl response. It was found that this processes are correlated, since the electrons caught in the traps of low temperature (50 - 250 C) of the Tl they are the electrons that recombining with more probability to provide the signal of OSL. According to these results it is possible to propose the diamond films as a good candidate for dosimetry to, using the traditional technique of Tl so much as well as the but recent of OSL. (Author)

  20. Optimization of CW-OSL parameters for improved dose detection threshold in Al2O3:C

    International Nuclear Information System (INIS)

    Rawat, N.S.; Dhabekar, B.; Kulkarni, M.S.; Muthe, K.P.; Mishra, D.R.; Soni, A.; Gupta, S.K.; Babu, D.A.R.

    2014-01-01

    Continuous wave optically stimulated luminescence (CW-OSL) is relatively a simple technique that offers good signal to noise ratio (SNR) and involves simple instrumentation. This study reports the influence and optimization of CW-OSL parameters on minimum detectable dose (MDD) using α-Al 2 O 3 :C phosphor. It is found that at a given stimulation intensity MDD in CW-OSL mode depends on signal integration time. At lower integration times MDD is inferior. It exhibits an improvement for intermediate values, shows a plateau region and deteriorates as integration time increases further. MDD is found to be ∼127 μGy at 4 mW/cm 2 stimulation intensity for integration time of 0.1 s, which improves to ∼10.5 μGy for 60 s. At stimulation intensity of 72 mW/cm 2 , MDD is 37 μGy for integration time of 60 s and improves significantly to 7 μGy for 1 s. - Highlights: • CW-OSL parameters are optimized to obtain best SNR and MDD in Al 2 O 3 :C. • MDD is found to depend on signal integration time and stimulation intensity. • With time, MDD initially improves, stabilizes then deteriorates. • At a given intensity, MDD is optimum for a certain range of integration time

  1. Study of sensitivity change of OSL signals from quartz and feldspars as a function of preheat temperature

    DEFF Research Database (Denmark)

    Jungner, H.; Bøtter-Jensen, L.

    1994-01-01

    and as a result, the equivalent dose (ED) would be underestimated. A study of sensitivity changes in feldspars and quartz was carried out with emphasis on the effect of preheat and annealing on the OSL signal. Measurement results obtained are presented, and possible elimination of errors in dating caused...

  2. An application of artificial neural intelligence for personal dose assessment using a multi-area OSL dosimetry system

    International Nuclear Information System (INIS)

    Lee, S.-Y.Sang-Yoon.; Kim, B.-H.Bong-Hwan; Lee, K.J.Kun Jai

    2001-01-01

    Significant advances have been made in recent years to improve measurement technology and performance of phosphor materials in the fields of optically stimulated luminescence (OSL) dosimetry. Pulsed and continuous wave OSL studies recently carried out on α-Al 2 O 3 : C have shown that the material seems to be the most promising for routine application of OSL for dosimetric purposes. The main objective of the study is to propose a new personal dosimetry system using α-Al 2 O 3 : C by taking advantage of its optical properties and energy dependencies. In the process of the study, a new dose assessment algorithm was developed using artificial neural networks in hopes of achieving a higher degree of accuracy and precision in personal OSL dosimetry system. The original hypothesis of this work is that the spectral information of an X- and γ-ray fields may be obtained by the analysis of the response of a multi-element system. In this study, a feedforward neural network using the error back-propagation method with Bayesian optimization was applied for the response unfolding procedure. The validation of the proposed algorithm was investigated by unfolding the 10 measured responses of α-Al 2 O 3 : C for arbitrarily mixed photon fields which range from 20 to 662 keV

  3. Quartz OSL dating of late quaternary Chinese and Serbian loess: A cross Eurasian comparison of dust mass accumulation rates

    DEFF Research Database (Denmark)

    Peric, Zoran; Adolphi, Emma Lagerbäck; Stevens, Thomas

    2018-01-01

    on multi-millennial timescales, with no detailed examination of dust MAR at the two ends of the Eurasian loess belt on shorter, sub-orbital scales. Here we present a detailed quartz optically stimulated luminescence (OSL) chronology from the Serbian Titel Loess Plateau (Veliki Surduk loess core...

  4. On the use of OSL of wire-bond chip card modules for retrospective and accident dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Woda, Clemens [Helmholtz Zentrum Muenchen - German Research Centre for Environmental Health, Institute of Radiation Protection, Ingolstaedter Landstrasse 1, D-85764 Neuherberg (Germany)], E-mail: clemens.woda@helmholtz-muenchen.de; Spoettl, Thomas [Infineon Technologies AG, Wernerwerkstrasse 1, D-93049 Regensburg (Germany)

    2009-05-15

    The potential of optically stimulated luminescence of wire-bond chip card modules, used in health insurance, ID, cash and credit cards for retrospective and accident dosimetry is investigated. Chip card modules obtained directly from the producer, using a widely spread UV-cured epoxy product for encapsulation, are used as basis for the study. The radiation sensitivity is due to silica grains added to the epoxy for controlling the thixotropic properties. Luminescence properties are complex due to the presumed thermo-optical release of electrons from the epoxy and transfer into the silica. Best results and highest sensitivity are obtained by using no or only low preheat treatments. A high degree of fading of the OSL signal during storage at room temperature is observed, which is tentatively explained by the superposition of thermal decay of shallow OSL traps and athermal (anomalous) decay of deeper OSL traps. The dose response of the OSL signal shows exponentially saturating behaviour, with saturation doses of 77 Gy or 9.6 Gy, depending on pretreatment. Dose recovery tests show that given doses can be recovered within a deviation of {+-}14%, if measured signals are corrected for fading. The minimum detectable dose is estimated at {approx}3 mGy, {approx}10 mGy and {approx}20 mGy for readouts immediately, 1 day and 10 days after exposure, respectively.

  5. Development of pulsed stimulation and Photon Timer attachments to the Risø TL/OSL reader

    DEFF Research Database (Denmark)

    Lapp, Torben; Jain, Mayank; Ankjærgaard, Christina

    2009-01-01

    in the OSL/IRSL process, a Photon Timer attachment to the Risø reader has been developed which measures data at 100 ps resolution. Furthermore a post-processing program has been developed to present the data in a compressed 3D form that gives a useful overview of the data before further analysis of relevant...

  6. Single-grain and multi-grain OSL dating of river terrace sediments in the Tabernas Basin, SE Spain

    DEFF Research Database (Denmark)

    Geach, M.R.; Thomsen, Kristina Jørkov; Buylaert, Jan-Pieter

    2015-01-01

    River terraces represent important records of landscape response to e.g. base-level change and tectonicmovement. Both these driving forces are important in the southern Iberian Peninsula. In this study,Optically Stimulated Luminescence (OSL) dating was used to date two principal river terraces...

  7. Optically stimulated luminescence (OSL) dating of shallow marine sediments to develop an analysis method of late Quaternary geodynamics

    International Nuclear Information System (INIS)

    Hataya, Ryuta; Shirai, Masaaki

    2003-01-01

    To develop an analysis method of geodynamics, we have examined the applicability of the OSL dating of marine terrace deposits. We have done the OSL dating, using the multiple-aliquot additive-dose technique, of shallow marine sediments from the upper part the Kioroshi Formation in Ibaraki Prefecture, which are correlated to Marine Oxygen Isotope Stage (MIS) 5e-5c. Marine terrace deposit consists mainly of shallow marine sediment. OSL ages of foreshore and foreshore-shoreface beds are 88-112 Ka, and are in good agreement with the geological/geomorphological data. On the other hand, OSL ages of the backshore bed are younger, and ones of the shoreface bed are older than geologically estimated ages. These results show that OPSL dating method can date shallow marine sediment using samples from foreshore and foreshore-shoreface beds, and that this method can distinguish terrace deposits formed in MIS5 and that in MIS7 by taking geomorphologic information into account. These results contribute to the characterization of long-term geological movement in coastal areas. (author)

  8. Optically stimulated luminescence (OSL) dating of quartzite cobbles from the Tapada do Montinho archaeological site (east-central Portugal)

    DEFF Research Database (Denmark)

    Sohbati, Reza; Murray, Andrew S.; Buylaert, Jan-Pieter

    2012-01-01

    The burial age of an alluvially deposited cobble pavement at the Tapada do Montinho archaeological site (east-central Portugal) is investigated using optically stimulated luminescence (OSL) dating. Measurements on the cobbles (quartzite clasts) were carried out on intact slices and large aliquots...

  9. Reliability of equivalent-dose determination and age-models in the OSL dating of historical and modern palaeoflood sediments

    DEFF Research Database (Denmark)

    Medialdea, Alicia; Thomsen, Kristina Jørkov; Murray, Andrew Sean

    2014-01-01

    model to small aliquot (similar to 30 grains) dose distributions. From our study we conclude that these and similar young slack-water flood deposits can be accurately dated using quartz OSL, opening up the possibility of establishing time series of flood discharge in catchments for which no instrumental...

  10. On the use of OSL of wire-bond chip card modules for retrospective and accident dosimetry

    International Nuclear Information System (INIS)

    Woda, Clemens; Spoettl, Thomas

    2009-01-01

    The potential of optically stimulated luminescence of wire-bond chip card modules, used in health insurance, ID, cash and credit cards for retrospective and accident dosimetry is investigated. Chip card modules obtained directly from the producer, using a widely spread UV-cured epoxy product for encapsulation, are used as basis for the study. The radiation sensitivity is due to silica grains added to the epoxy for controlling the thixotropic properties. Luminescence properties are complex due to the presumed thermo-optical release of electrons from the epoxy and transfer into the silica. Best results and highest sensitivity are obtained by using no or only low preheat treatments. A high degree of fading of the OSL signal during storage at room temperature is observed, which is tentatively explained by the superposition of thermal decay of shallow OSL traps and athermal (anomalous) decay of deeper OSL traps. The dose response of the OSL signal shows exponentially saturating behaviour, with saturation doses of 77 Gy or 9.6 Gy, depending on pretreatment. Dose recovery tests show that given doses can be recovered within a deviation of ±14%, if measured signals are corrected for fading. The minimum detectable dose is estimated at ∼3 mGy, ∼10 mGy and ∼20 mGy for readouts immediately, 1 day and 10 days after exposure, respectively.

  11. Introduction of a new dosimetry system based on optically stimulated luminescence (OSL) in our personal monitoring service

    International Nuclear Information System (INIS)

    Hubner, S.

    2014-08-01

    The personal monitoring service named Auswertungsstelle is part of the Helmholtz Zentrum Munchen, a non-profit-making research center in Germany. As one of the four monitoring services in Germany, we have been a reliable partner in radiation protection for more than 60 years. With about 1.9 million dose assessments per year, we are the largest monitoring service in Europe. For dozens of years, our main dosimeter used in whole-body dosimetry has been a film dosimeter. Although its dosimetric properties are still up to date, film dosimetry won.t be a sustainable technique for the use in monitoring services. Therefore, a project with the objective of investigating alternative dosimetric materials and methods was launched in the late 1990 at the Helmholtz Zentrum Munchen. Based on this research work, the use of Be O as an OSL dosimeter was studied by the radiation physics group of the Tu Dresden, by order and on account of the Auswertungsstelle at the Helmholtz Zentrum Munchen. It was shown, that ceramic Be O features promising dosimetric properties, making Be O detectors particularly suitable for being used in all applications in whole-body dosimetry measuring photons. Ceramic Be O material has an excellent resistance to environmental influences. The Be O chips are almost tissue equivalent. Therefore, these detectors show low photon energy dependence. A new personal dosimetry system based on the OSL dosimetry of Be O was developed. Applying this system, the Auswertungsstelle offers OSL-dosimeters for official monitoring of the Personal Dose Equivalent Hp(10) since 2011. This OSL-System is accredited according to DIN IEC 62387 and we obtained the corresponding type approval by the Ptb, the national metrology institute in Germany. Sophisticated logistics was developed and installed. High degree of automation was achieved by robots for dosimeter assembly and machines for packing, labelling and unpacking of the dosimeters. To become a sustainable dosimetry system not only

  12. Introduction of a new dosimetry system based on optically stimulated luminescence (OSL) in our personal monitoring service

    Energy Technology Data Exchange (ETDEWEB)

    Hubner, S., E-mail: stephan.huebner@helmholtz-muenchen.de [Helmholtz Zentrum Munchen, German Research Center for Environmental Health, D-80219, Munich (Georgia)

    2014-08-15

    The personal monitoring service named Auswertungsstelle is part of the Helmholtz Zentrum Munchen, a non-profit-making research center in Germany. As one of the four monitoring services in Germany, we have been a reliable partner in radiation protection for more than 60 years. With about 1.9 million dose assessments per year, we are the largest monitoring service in Europe. For dozens of years, our main dosimeter used in whole-body dosimetry has been a film dosimeter. Although its dosimetric properties are still up to date, film dosimetry won.t be a sustainable technique for the use in monitoring services. Therefore, a project with the objective of investigating alternative dosimetric materials and methods was launched in the late 1990 at the Helmholtz Zentrum Munchen. Based on this research work, the use of Be O as an OSL dosimeter was studied by the radiation physics group of the Tu Dresden, by order and on account of the Auswertungsstelle at the Helmholtz Zentrum Munchen. It was shown, that ceramic Be O features promising dosimetric properties, making Be O detectors particularly suitable for being used in all applications in whole-body dosimetry measuring photons. Ceramic Be O material has an excellent resistance to environmental influences. The Be O chips are almost tissue equivalent. Therefore, these detectors show low photon energy dependence. A new personal dosimetry system based on the OSL dosimetry of Be O was developed. Applying this system, the Auswertungsstelle offers OSL-dosimeters for official monitoring of the Personal Dose Equivalent Hp(10) since 2011. This OSL-System is accredited according to DIN IEC 62387 and we obtained the corresponding type approval by the Ptb, the national metrology institute in Germany. Sophisticated logistics was developed and installed. High degree of automation was achieved by robots for dosimeter assembly and machines for packing, labelling and unpacking of the dosimeters. To become a sustainable dosimetry system not only

  13. Development and implementation of In-vivo dosimetry with OSL in special techniques (IMRT, TBI, TSE); Desarrollo e implementacion de dosimetria In-vivo con OSL en tecnicas especiales (IMRT, TBI, TSE)

    Energy Technology Data Exchange (ETDEWEB)

    Bourel, V., E-mail: vbourel@favaloro.edu.ar [Universidad Favaloro, Buenos Aires (Argentina)

    2015-10-15

    Full text: Special techniques of radiation treatments generally require a quality control very thorough because in general tend to be high-risk techniques of complications due to imparting high doses in a small volume or involve a very large volume of the patient are the techniques of total body irradiation either photons or electrons. In these techniques a moderate error in the given dose can mean a very significant variation in tumor control probability (Tcp) or the likelihood of complications in normal tissues has happened in known published accidents and can be deduced from the typical sigmoid curve of response vs. dose. The technique In-vivo dosimetry has proved useful a final tool to detect any possible error in the chain of procedures to which is subjected prior to radiation treatment. This chain of procedures includes initial imaging, treatment planning involving the calibration of the equipment s, location and immobilization of the patient. The In-vivo dosimetry involves a measurement of the dose delivered to the patient in the treatment conditions to detect a possible deviation between the prescribed and the delivered dose. The experience so far has been done mainly with semiconductor elements (diodes) or thermoluminescent dosimetry. The advent of the optically stimulated luminescence dosimeters (OSLD), particularly in the nano Dots form, is a very appropriate tool for its size, ease of handling, accurate and fast reading. With these dosimeters has been developed and implemented the In-vivo dosimetry in three techniques in which the accuracy of the dose delivered is extremely important. These techniques are the treatment of intensity modulated radiation therapy (IMRT) that seeks to impart a very high dose in the tumor tissues protecting organs in risk around the target and the techniques of total body irradiation with photons, whose function is to generate immune suppression in patients before being transplanted, or with electrons for the treatment of

  14. OSL and TL dosimeter characterization of boron doped CVD diamond films

    Science.gov (United States)

    Gonçalves, J. A. N.; Sandonato, G. M.; Meléndrez, R.; Chernov, V.; Pedroza-Montero, M.; De la Rosa, E.; Rodríguez, R. A.; Salas, P.; Barboza-Flores, M.

    2005-04-01

    Natural diamond is an exceptional prospect for clinical radiation dosimetry due to its tissue-equivalence properties and being chemically inert. The use of diamond in radiation dosimetry has been halted by the high market price; although recently the capability of growing high quality CVD diamond has renewed the interest in using diamond films as radiation dosimeters. In the present work we have characterized the dosimetric properties of diamond films synthesized by the HFCVD method. The thermoluminescence and the optically stimulated luminescence of beta exposed diamond sample containing a B/C 4000 ppm doping presents excellent properties suitable for dosimetric applications with β-ray doses up to 3.0 kGy. The observed OSL and TL performance is reasonable appropriate to justify further investigation of diamond films as dosimeters for ionizing radiation, specially in the radiotherapy field where very well localized and in vivo and real time radiation dose applications are essential.

  15. OSL dating of fine-grained quartz from Holocene Yangtze delta sediments

    DEFF Research Database (Denmark)

    Sugisaki, Saiko; Buylaert, Jan-Pieter; Murray, Andrew

    2015-01-01

    Holocene flood events in the Yangtze River are associated with variations in East Asian Summer Monsoon (EASM) precipitation, and so Yangtze delta sediments may preserve information about the frequency and magnitude of EASM precipitation. These flood/drought cycles of the EASM directly affect...... the living standards of East Asian population. However, despite its importance, little chronological control is available for the Yangtze Delta sediments; because biogenic carbonate only occurs sporadically, it has proved the difficulty to discuss sedimentation mechanisms and rates in any detail. In 2013 two...... sediment cores (YD13-G3 and H1) were taken from the Yangtze subaqueous delta to investigate precipitation history. In this study, we investigate the potential of quartz OSL dating of the fine silt fraction (fine-grained quartz; 4-11 μm) from these cores to estimate the depositional age of the sediments. We...

  16. The dose dependency of the over-dispersion of quartz OSL single grain dose distributions

    DEFF Research Database (Denmark)

    Thomsen, Kristina Jørkov; Murray, Andrew S.; Jain, Mayank

    2012-01-01

    The use of single grain quartz OSL dating has become widespread over the past decade, particularly with application to samples likely to have been incompletely bleached before burial. By reducing the aliquot size to a single grain the probability of identifying the grain population most likely...... to have been well-bleached at deposition is maximised and thus the accuracy with which the equivalent dose can be determined is – at least in principle – improved. However, analysis of single grain dose distributions requires knowledge of the dispersion of the well-bleached part of the dose distribution....... This can be estimated by measurement of a suitable analogue, e.g. a well-bleached aeolian sample, but this requires such an analogue to be available, and in addition the assumptions that the sample is in fact a) well-bleached, and b) has a similar dose rate heterogeneity to the fossil deposit. Finally...

  17. A compact design for monochromatic OSL measurements in the wavelength range 380-1020 NM

    DEFF Research Database (Denmark)

    Bøtter-Jensen, L.; Poolton, N.R.J.; Willumsen, F.

    1994-01-01

    automated Riso TL/OSL dating apparatus, thus allowing for either routine scanning or more detailed thermo-optical investigations. The high throughput efficiency of the unit means that the existing 75 W tungsten-halogen lamp can be directly used for such measurements on both quartz and feldspar samples......The development and performance of a compact module is described that allows for the monochromatic illumination of samples in the wavelength range 380-1020 nm, enabling the measurement of energy-resolved optically stimulated luminescence. The unit is designed to couple directly to the existing....... The design allows for rapid spectral scanning with a choice of resolution of anywhere between 10 and 80 nm: stray light levels are less than 0.01%. The unit can equally be used for recording wavelength-resolved emission spectra, whether photo-excited or thermally stimulated; the capabilities of the system...

  18. On the use of OSL of chip card modules with molding for retrospective and accident dosimetry

    International Nuclear Information System (INIS)

    Woda, Clemens; Fiedler, Irene; Spöttl, Thomas

    2012-01-01

    The potential of optically stimulated luminescence of wire-bond chip card modules with molded encapsulations for retrospective and accident dosimetry is investigated. Contact-based and contactless modules were studied, the latter finding potential use in electronic documents (e.g. electronic passports, electronic identity cards). Investigations were carried out on intact as well as chemically prepared modules, extracting the filler material. Contact-based modules are characterized according to zero dose signal, correlation between OSL and TL, dose response and long-term signal stability. For prepared modules, the minimum detectable dose immediately after irradiation is 3 mGy and between 20 and 200 mGy for contact-based and contactless modules, respectively. Dose recovery tests on contact-based modules indicate that the developed methodology yields results with sufficient accuracy for measurements promptly after irradiation, whereas a systematic underestimation is observed for longer delay times. The reasons for this behaviour are as yet not fully understood.

  19. New data on OSL dating of Early Khalynian deposits of Northern Caspian

    Science.gov (United States)

    Sychev, Nikita; Yanina, Tamara; Svitoch, Alexander; Kurbanov, Redzhep; Badyukova, Ekaterina

    2016-04-01

    Ponto-Caspian region is the key region the study of which can provide information about the paleogeographic history of the central Eurasia, particularly revealing the history of the East European Plain, the Caucasus and Central Asia. However, despite the long history of the study, today there is no accepted general stratigraphic scheme of the Caspian Sea. One of the most interesting and important stages of Late Pleistocene history of Caspian is Khalynian transgression which is divided into two major phases: early and ate. In the Caspian lowland Lower Khalynian stage are represented by a unique type of deposit - "chocolate clays". A distinctive feature of these sediments is widely distributed among Lower Khalynian deposits of Northern Caspian and the Volga region. All clay deposits are confined to the diverse origins of depression before-Khalynian relief. Chocolate clays formation consists of facies: mono-clay (typological), layered, sand- and silty-clay (Svitoch, Yanina, 1997). Determining the age of chocolate clays by optically stimulated luminescence (OSL) in our view will allow bettering the understanding of their genesis. Age of chocolate clays of Lower Volga was widely dated using the radiocarbon. However, the existing chronology is controversial, raises a number of issues, primarily due to the material of which are used for dating - thin shells of Caspian mollusks of the Didacna Eichw. genus, which are characterized by a significant isotopic exchange with the enclosing sediments (Arslanov, 2015). Lower Volga region is characterized by very complex geological structure of the Late Pleistocene deposits (alternating continental aeolian, alluvial and slope sediments with marine Caspian deposits of different age). There are many conflicting opinions, not only with respect to paleogeographic features of the area, but also to its precise chronology. The differences in opinion over the age of the individual stages of development of the Caspian Sea (transgressions and

  20. De determination for young samples using the standardised OSL response of coarse-grain quartz

    International Nuclear Information System (INIS)

    Burbidge, C.I.; Duller, G.A.T.; Roberts, H.M.

    2006-01-01

    It has recently been shown that it is possible to construct standardised curves of the sensitivity corrected growth in optically stimulated luminescence (OSL) with exposure to ionising radiation, and that they may be used in the dating of quartz and polymineral samples. Standardised growth curves are particularly advantageous where measurement time is limited, as once they have been defined, only the natural signal and the response to a subsequent test dose are required in order to determine the equivalent dose of a sub-sample. The present study is concerned with the application of the standardised growth curve approach to OSL dating of Holocene age samples. Systematic changes in the shape of the standardised growth curve of coarse-grain quartz are identified as the size of the test dose is varied, because of non-proportionality between the test dose and the luminescence test response. The effect is characterised by fitting the change in gradient of the standardised growth curve as test dose is varied. An equation is defined to describe standardised growth as a function of regenerative dose and test dose. Regenerative dose responses of other samples in this study are treated as unknowns and recovered through different growth curves to compare precision and accuracy of various methods of D e determination. The standardised growth curve is found to yield similar precision to conventional fits of single aliquot regenerative data, but slightly poorer accuracy. The standardised growth curve approach was refined by incorporating the measurement of one regenerative response for each aliquot as well as its natural signal. Measurements of this additional data point for aliquots of 22 samples were used to adjust the standardised growth equation, improving its accuracy. The incorporation of this additional data point also indicated a systematic uncertainty of 2.4% in the estimates of D e

  1. Resetting of Quartz OSL (optically stimulated luminescence) Signals by Frictional Heating in Experimentally Sheared Gouges at Seismic Slip Rates.

    Science.gov (United States)

    Kim, J. H.; Choi, J. H.; Chauhan, N.; Lee, S.; Hirose, T.; Ree, J. H.

    2014-12-01

    Recent studies on natural and experimental seismic faults have revealed that frictional heating plays an important role in earthquake dynamics as well as in producing mineralogical and microstructural signatures of seismic faulting. Here, we report changes in OSL signals in quartz by frictional heating in experimental fault gouges. The gouges (80% of quartz and 20% of bentonite by weight) with a thickness of 1 mm were sheared between sandstone cylinders (diameter: 25 mm) at a normal stress of 1 MPa and slip rate of 1.31 m/s. The quartz grains from a sand dune on the western coast of South Korea were sieved to select size fractions between 90 and 250 μm. The equivalent dose (De) of the undeformed quartz grains was 8.0 ± 0.3 Gy. Upon displacement, the friction abruptly increases to the 1st peak (with friction coefficient μ ≈ 0.75) followed by slip weakening. Then the fault zones show two more peak frictions (μ ≈ 0.53~0.75) and finally reach a steady-state friction (μ ≈ 0.2~0.35). The fault can be divided into three zones based grain size (thus slip rate); slip localization (SLZ), intermediate slip-rate (ISZ) and low slip-rate (LSZ) zones. SLZ develops adjacent to the moving side of the sandstone cylinder with P-foliation and shear band. The size of quartz (Dq) in ISZ and LSZ is 5-30 μm and 50-250 μm, respectively. SEM and TEM analyses indicate that the fault gouge of SLZ consists of subangular quartz clasts (Dq ≈ 3 μm) and matrix of nano-scale quartz, unidentified silicate minerals and amorphous material. The fault zones were sectioned into six layers (~160 µm thick for each layer) parallel to the fault zone boundary for OSL analyses. Quartz grains from all the layers except the one immediately adjacent to the stationary side of the sandstone cylinder show De of 'effectively' 0 Gy indicating a full resetting of OSL signals. The partial resetting of OSL signal in the layer adjacent to the stationary side of the cylinder indicates the temperature (T

  2. Dependence of the anomalous fading of the TL and blue-OSL of fluorapatite on the occupancy of the tunnelling recombination sites

    International Nuclear Information System (INIS)

    Tsirliganis, N.C.; Polymeris, G.S.; Kitis, G.; Pagonis, V.

    2007-01-01

    The anomalous fading (AF) of thermoluminescence (TL) and optically stimulated luminescence (OSL) signals in Durango apatite is attributed to tunnelling effects. Electrons from the TL and OSL traps in this material are transferred, via a tunnelling effect, to the recombination sites. The availability of recombination sites for tunnelled electrons is of major importance for the degree of AF rate observed in this material. It is expected that a variation of the number of the electron recombination sites will be reflected in the experimentally measured AF rate. In the present work an investigation of the recombination sites for the tunnelled electrons is attempted by studying the AF effect using a special technique, in which the anomalously faded TL (OSL) is replaced by an equal amount of TL (OSL) induced by a beta dose

  3. Potential and limits of OSL, TT-OSL, IRSL and pIRIR290 dating methods applied on a Middle Pleistocene sediment record of Lake El'gygytgyn, Russia

    Directory of Open Access Journals (Sweden)

    A. Zander

    2013-03-01

    Full Text Available This study tests the paleomagnetic and proxy-data based Mid- to Upper Pleistocene sediment deposition history of Lake El'gygytgyn by applying different approaches of luminescence dating techniques on sediment cores taken from the centre of the 175 m deep lake. For dating polymineral and quartz fine grains (4–11 μm grain size range were extracted from nine different levels from the upper 28 m of sediment cores 5011-1A and 5011-1B. According to the independent age model, the lowest sample from 27.8–27.9 m below lake bottom level correlates to the Brunhes-Matuyama (B/M reversal. Polymineral sub-samples were analysed by infra-red stimulated luminescence (IRSL and post-IR IRSL measured at 290 °C (pIRIR290 using single aliquot regenerative dose (SAR sequences. SAR protocols were further applied to measure the blue light optically stimulated luminescence (OSL and thermally-transferred OSL (TT-OSL of fine-grained quartz supplemented by a multiple aliquot approach. Neither low temperature IRSL measurements at 50 °C nor any OSL dating approach on quartz yielded reliable results. Deconvolution of their dose response curves revealed a pseudo-increase of the dose response curves and explains the observed underestimation. The pIRIR protocol applied to polymineral fine grains was the only luminescence technique able to provide dating results of acceptable accuracy up to ca. 700 ka when correlated to the existing proxy-data and paleomagnetic based age record. We present the potential and limits of the different dating techniques and a correlation of pIRIR290 results with the proxy-data based age model.

  4. Attaining provenance proxies from OSL and TL sensitivities: Coupling with grain size and heavy minerals data from southern Brazilian coastal sediments

    International Nuclear Information System (INIS)

    Zular, André; Sawakuchi, André O.; Guedes, Carlos C.F.; Giannini, Paulo C.F.

    2015-01-01

    In the São Francisco do Sul (SFS) barrier in southern Brazil, the optically stimulated luminescence (OSL) and thermoluminescence (TL) sensitivities of coastal sands vary according to geomorphological units. Sands from older beach ridges (ages older than 2000 years ago) show higher OSL and TL sensitivities than younger units (ages younger than 2000 years). Geomorphological units in the SFS attest to changes in provenance as a result of a coastal climate shift evidenced through grain size and heavy mineral analysis. We argue that in the SFS barrier sands, OSL and TL sensitivity signals provide an additional proxy to climate events and can be used as an alternative method to assess changes in provenance and tracking source-to-sink systems to monitor past and future environmental changes. - Highlights: • OSL and TL sensitivities are confronted with grain size and heavy minerals data. • We report OSL and 110 °C TL sensitivities as provenance proxies. • 110 °C TL sensitivity outlines environmental changes better than OSL sensitivity data.

  5. Intercomparison of dispersed radiation readings among film dosimetry, electronic and OSL with X-rays for low dose; Intercomparacion de lecturas de radiacion dispersa entre dosimetria film, electronica y OSL con rayos X para dosis bajas

    Energy Technology Data Exchange (ETDEWEB)

    Andisco, D. [Universidad de Buenos Aires, Facultad de Medicina, Paraguay 2155, C1121AAA Buenos Aires (Argentina); Blanco, S. [CONICET, Saavedra 15, C1083ACA Buenos Aires (Argentina); Bourel, V.; Schmidt, L. [Universidad Favaloro, Facultad de Ciencias e Ingenieria, Solis 453, C1078AAI, Buenos Aires (Argentina); Di Risio, C., E-mail: dandisco@fmed.uba.ar [Universidad de Belgrano, Facultad de Ingenieria, Zabala 1837, C1426DQG, Buenos Aires (Argentina)

    2014-08-15

    One of the personal dosimetry methods more used for several decades is the dosimetry type film, characterized to possess readings with certain margin of trust. Today other methods exist that many times are presupposed more reliable due to the nature of the detection like the electronic dosimeters or the OSL (Optically Stimulated Luminescence) dosimetry. With the purpose of comparing different methods and to can determining the existent differences among each method has been carried out an intercomparison assay. The different dosimeters have been exposed to dispersed radiation generated by a Hemodynamics equipment of the type -arch in C- and a dispersing system of the primary beam. Film dosimeters have been used; OSL (In Light), OSL (Nano Dots) and Electronic with the purpose of knowing and to valorize the existent differences among its readings. Always, the intercomparison exercises have demonstrated to be an useful tool when establishing the measurement capacity and the quality of the results emitted by the laboratories of personal dosimetry services. Also, this type of assays allows obtaining quality indicators of the laboratory performance and they are habitual part of the procedures for accreditation of the same ones. The Optically Stimulated Luminescence is a technology that has grown in Argentina so much in the area of personal dosimetry as in dosimetry in vivo (radiotherapy area). In this intercomparison study, the answers corresponding to each technology were looked for oneself irradiation of the disperse type, that is to say, of very low energy. (Author)

  6. TL, OSL and C-14 dating results of the sediments and bricks from mummified nuns' grave

    Energy Technology Data Exchange (ETDEWEB)

    Tudela, Diego R.G.; Tatumi, Sonia H.; Yee, Marcio; Brito, Silvio L.M., E-mail: tatumi@fatecsp.br [Faculdades de Tecnologia de Sao Paulo (FATECs/CEETEPS/UNESP), Sao Paulo, SP (Brazil). Centro Estadual de Educacao Tecnologica Paula Souza; Morais, Jose L.; Morais, Daisy de; Piedade, Silvia C. [Universidade de Sao Paulo (USP), SP (Brazil). Museu de Arqueologia e Etnologia; Munita, Casimiro S.P.; Hazenfratz, Roberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2012-06-15

    This paper presents the results of TL and OSL dating of soil and fragments of bricks from a grave, which was occupied by two mummified nuns, found at 'Luz' Monastery, located in the state of Sao Paulo, Brazil. The TL and OSL ages were compared to C-14 dating ones obtained from bone collagens of the mummies. The majority of the ages is related to the eighteenth century. The gamma-ray spectroscopy was used to evaluate natural radioisotope concentrations in the samples, and by using these concentrations the annual dose rates, from 3.0 to 5.3 Gy/kyr, were obtained. Neutron activation analysis was performed and the radioisotope contents results are in agreement with those obtained by gamma-ray spectroscopy. The contents of U, Th and Ce elements were higher than those found in usual sediments. (author)

  7. Real time dose rate measurements with fiber optic probes based on the RL and OSL of beryllium oxide

    International Nuclear Information System (INIS)

    Teichmann, T.; Sponner, J.; Jakobi, Ch.; Henniger, J.

    2016-01-01

    This work covers the examination of fiber optical probes based on the radioluminescence and real time optically stimulated luminescence of beryllium oxide. Experiments are carried out to determine the fundamental dosimetric and temporal properties of the system and evaluate its suitability for dose rate measurements in brachytherapy and other applications using non-pulsed radiation fields. For this purpose the responses of the radioluminescence and optically stimulated luminescence signal have been investigated in the dose rate range of 20 mGy/h to 3.6 Gy/h and for doses of 1 mGy up to 6 Gy. Furthermore, a new, efficient analysis procedure, the double phase reference summing, is introduced, leading to a real time optically stimulated luminescence signal. This method allows a complete compensation of the stem effect during the measurement. In contrast to previous works, the stimulation of the 1 mm cylindrical beryllium oxide detectors is performed with a symmetric function during irradiation. The investigated dose rates range from 0.3 to 3.6 Gy/h. The real time optically stimulated luminescence signal of beryllium oxide shows a dependency on both the dose rate and the applied dose. To overcome the problem of dose dependency, further experiments using higher stimulation intensities have to follow. - Highlights: • RL and OSL measurements with BeO extended to low dose (rate) range. • A new method to obtain the real time OSL: Dual Phase Reference Summing. • Real time OSL signal shows both dose and dose rate dependency. • Real time OSL enables a complete discrimination of the stem effect.

  8. Intercomparison of dispersed radiation readings among film dosimetry, electronic and OSL with X-rays for low dose

    International Nuclear Information System (INIS)

    Andisco, D.; Blanco, S.; Bourel, V.; Schmidt, L.; Di Risio, C.

    2014-08-01

    One of the personal dosimetry methods more used for several decades is the dosimetry type film, characterized to possess readings with certain margin of trust. Today other methods exist that many times are presupposed more reliable due to the nature of the detection like the electronic dosimeters or the OSL (Optically Stimulated Luminescence) dosimetry. With the purpose of comparing different methods and to can determining the existent differences among each method has been carried out an intercomparison assay. The different dosimeters have been exposed to dispersed radiation generated by a Hemodynamics equipment of the type -arch in C- and a dispersing system of the primary beam. Film dosimeters have been used; OSL (In Light), OSL (Nano Dots) and Electronic with the purpose of knowing and to valorize the existent differences among its readings. Always, the intercomparison exercises have demonstrated to be an useful tool when establishing the measurement capacity and the quality of the results emitted by the laboratories of personal dosimetry services. Also, this type of assays allows obtaining quality indicators of the laboratory performance and they are habitual part of the procedures for accreditation of the same ones. The Optically Stimulated Luminescence is a technology that has grown in Argentina so much in the area of personal dosimetry as in dosimetry in vivo (radiotherapy area). In this intercomparison study, the answers corresponding to each technology were looked for oneself irradiation of the disperse type, that is to say, of very low energy. (Author)

  9. Comparison of single-grain and small-aliquot OSL dose estimates in <3000 years old river sediments from South India

    International Nuclear Information System (INIS)

    Thomas, P.J.; Jain, M.; Juyal, N.; Singhvi, A.K.

    2005-01-01

    We report on OSL dose distributions derived from small-aliquot and single grains of quartz in young fluvial sediments sampled from the Penner River basin, South India. The single-grain dose distributions suggest that 13 out of 19 samples were well bleached. In many well-bleached samples, there was an underestimation in the single-aliquot dose estimates as compared to those from the single grain-the difference between average dose estimates determined by the two methods ranged from ∼1% to 31%. Such a dose underestimation was not detectable in poorly bleached samples. Various possible reasons for the discrepancy between single-grain and small-aliquot dose estimates are discussed. Although there is no satisfactory explanation for this discrepancy, we speculate that the difference in the stimulation wavelengths, 470+/-30nm in the case of single-aliquot and 532nm in the case of single grains, could perhaps be one of the reasons; this may occur because the stimulation wavelength affects the proportion of the medium and slow components in the initial signal

  10. Obese individuals with more components of the metabolic syndrome and/or prediabetes demonstrate decreased activation of reward-related brain centers in response to food cues in both the fed and fasting states: a preliminary fMRI study.

    Science.gov (United States)

    Farr, O M; Mantzoros, C S

    2017-03-01

    It remains unknown whether obese individuals with more components of the metabolic syndrome and/or prediabetes demonstrate altered activation of brain centers in response to food cues. We examined obese individuals with prediabetes (n=26) vs obese individuals without prediabetes (n=11) using fMRI. We also performed regression analyses on the basis of the number of MetS components per subject. Obese individuals with prediabetes have decreased activation of the reward-related putamen in the fasting state and decreased activation of the salience- and reward-related insula after eating. Obese individuals with more components of MetS demonstrate decreased activation of the putamen while fasting. All these activations remain significant when corrected for BMI, waist circumference (WC), HbA1c and gender. Decreased activation in the reward-related central nervous system areas among the obese is more pronounced in subjects with prediabetes and MetS. Prospective studies are needed to quantify their contributions to the development of prediabetes/MetS and to study whether they may predispose to the exacerbation of obesity and the development of comorbidities over time.

  11. 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.

  12. Fake age hiatus in a loess section revealed by OSL dating of calcrete nodules

    Science.gov (United States)

    Zhang, Junjie; Li, Sheng-Hua; Sun, Jimin; Hao, Qingzhen

    2018-04-01

    Optically stimulated luminescence (OSL) dating on potassium feldspar has been performed with high resolution in the Luochuan section in the Chinese Loess Plateau. An age hiatus of ∼ 15 ka is found at the top of L2 layer within the loess/paleosol sequences. The age of the potassium feldspar from the calcrete nodules along the S1/L2 boundary is significantly older than those of the paleosol and loess samples lying above and below the boundary. The age overestimation of the potassium feldspar from calcrete nodules is caused by the underestimation of the dose rate, because accretion of carbonates could dilute the radioactivity. The age hiatus at the top of L2 also resulted from the underestimation of the dose rates of four loess samples beneath this hiatus. These four loess samples have high CaO concentrations. Ages of these samples are overestimated in the similar way as the nodules, but with smaller degrees. All results suggest that the accretion of carbonates happened after the loess deposition. The carbonate accretion process of the calcrete nodules has been simulated with accumulation models. The accretion can be as young as 46 ka, assuming the calcrete nodules formed rapidly at a certain time point. For slow and gradual accretion models, the carbonate started to accumulate slowly since the dust deposition and the accumulation became faster afterwards. The transition of the accretion rate may relate to the climate change or a change in the carbonate leaching and re-precipitation system.

  13. Error variation in OSL palaeodose estimates from single aliquots of quartz: a factorial experiment

    International Nuclear Information System (INIS)

    Galbraith, R.F.; Roberts, R.G.; Yoshida, H.

    2005-01-01

    We use a factorial experiment to study systematic and random differences between measured OSL palaeodoses for a variety of quartz samples. These include samples that have absorbed either a large or small natural or laboratory-induced radiation dose, either with or without prior heating or bleaching. The systematic factors studied are the size of the test dose, the preheat temperature and the number of quartz grains in each multi-grain aliquot. Palaeodoses were estimated using a single-aliquot regenerative-dose protocol. The main parameter of interest is the amount of random variation, over and above that due to photon counting statistics, to be expected between estimates from aliquots that have received the same radiation dose. This over-dispersion is generally larger for natural samples than for artificially bleached ones, and it varies from about 1% in the most favourable cases to about 18% for small aliquots of a sample that had received a natural dose of about 46 Gy. The latter is comparable to the over-dispersion reported for single grains of natural quartz that are thought to have been well-bleached at the time of deposition. The factorial experiment also revealed a number of systematic effects. In particular, measured palaeodoses using a preheat temperature of 260 deg. C were systematically lower than those using 180 deg. C, by up to about 5% in some cases

  14. Characterization and management of radioactive sodium and other reactor components as input data for the decommissioning of liquid metal-cooled fast reactors. A compilation of data produced of data produced by members of the IAEA technical working group on fast reactors (TWG-FR) at two consultancies and one technical committee meeting. Working material

    International Nuclear Information System (INIS)

    2002-01-01

    A number of liquid metal cooled fast reactors (LMFRs) are in operation and, some have already been shut down; other reactors will reach the end of their design lifetime in a few years and become candidates for decommissioning. It is unfortunate that little consideration was devoted to decommissioning of reactors at the plant design and construction stage. It is with this focus that the Technical Working Group on Fast Reactors (TWGFR) recommended that the IAEA organize the exchange of information on LMFRs decommissioning technology. It was pointed out that the decommissioning of small sodium-cooled reactors has shown that there are two basic differences between thermal and fast reactors decommissioning: on the one side, the treatment and disposal of radioactive sodium coolant, and on the other side, the management of reactor components, for which the structural materials are activated in depth by fast neutrons. To this end, a Technical Committee Meeting on Sodium Removal and Disposal from LMFRs in Normal Operation and in the framework of Decommissioning (Aix-en-Provence, France, November 1997) and two Consultancies on Decommissioning of the Kazakh BN-350 LMFR (Vienna, Austria, October 1996; Obninsk, Russian Federation, February 1998) were convened by the IAEA. These Meetings brought together a group of experts from France, Russia, Kazakhstan, the UK, and the USA to exchange information on, and to review current technical knowledge and experience in the management of radioactive coolant and reactor components following closing of LMFRs, as well as their design features and operating experience relevant for decommissioning procedures. The report provides general and detailed information on activation characteristics of the primary coolant; treatment and disposal of the spent sodium; removal of the residual sodium deposits and decontamination; the activation characteristics of the reactor components and the management of the latter. The recurring theme is finding

  15. Assessment of influence of OSL dosimeters in the skin dose in radiotherapy: study for Monte Carlo simulation; Avaliacao da influencia de dosimetros OSL na dose na pele em radioterapia: estudo por simulacao Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Schuch, Franciely F.; Nicolucci, Patricia, E-mail: franschuch@yahoo.com.br [Universidade de Sao Paulo (USP), Ribeiraoo Preto, SP (Brazil)

    2017-11-01

    The interest in optically stimulated luminescence (OSL) dosimetry materials is growing due to its potential use in quality control in Radiotherapy. The use of these dosimeters for in vivo dosimetry, however, may influence the dose to the skin and deeper tissues in the patient. The goal of this study is to evaluate the influence of the OSL Al{sub 2}O{sub 3} material in dose deposited in the skin and deep in Radiotherapy. Monte Carlo simulation is used to evaluate this purpose when OSL dosimeters of Al{sub 2}O{sub 3} are positioned on the skin surface of the patient. Percentage depth dose curves for clinical beams of 6 and 10 MV were simulated with and without the presence of the dosimeter on the surface of a water phantom. The results showed a decrease of doses in regions close to the surface of the skin. In the build-up region, the maximum decreases of dose produced by the presence of the dosimeters were 52,5% and 47,5% for the 6 and 10 MV beams, respectively. After the build-up region, there are not significant changes in the doses for any of the used beams. The differences of doses found are due to the influence of the dosimetric material on the relative fluence of electrons near the end surface of the dosimeter. Thus, the results showed that the presence of the dosimetric material on the surface interferes on the skin dose. However, these dosimeters do not cause dose variations in depths of clinical interest, allowing its application in routine in vivo dosimetry in Radiotherapy. (author)

  16. The dose dependency of the over-dispersion of quartz OSL single grain dose distributions

    International Nuclear Information System (INIS)

    Thomsen, Kristina J.; Murray, Andrew; Jain, Mayank

    2012-01-01

    The use of single grain quartz OSL dating has become widespread over the past decade, particularly with application to samples likely to have been incompletely bleached before burial. By reducing the aliquot size to a single grain the probability of identifying the grain population most likely to have been well-bleached at deposition is maximised and thus the accuracy with which the equivalent dose can be determined is – at least in principle – improved. However, analysis of single grain dose distributions requires knowledge of the dispersion of the well-bleached part of the dose distribution. This can be estimated by measurement of a suitable analogue, e.g. a well-bleached aeolian sample, but this requires such an analogue to be available, and in addition the assumptions that the sample is in fact a) well-bleached, and b) has a similar dose rate heterogeneity to the fossil deposit. Finally, it is an implicit assumption in such analysis that any over-dispersion is not significantly dose dependent. In this study we have undertaken laboratory investigations of the dose dependency of over-dispersion using a well-bleached modern sample with an average measured dose of 36 ± 3 mGy. This sample was prepared as heated (750 °C for 1 h), bleached and untreated portions which were then given uniform gamma doses ranging from 100 mGy to 208 Gy. We show that for these samples the relative laboratory over-dispersion is not constant as a function of dose and that the over-dispersion is smaller in heated samples. We also show that the dim grains in the distributions have a greater over-dispersion than the bright grains, implying that insensitive samples will have greater values of over-dispersion than sensitive samples.

  17. Combination of a fast white-light interferometer with a phase shifting interferometric line sensor for form measurements of precision components

    Science.gov (United States)

    Laubach, Sören; Ehret, Gerd; Riebling, Jörg; Lehmann, Peter

    2017-06-01

    By means of an interferometric line sensor system, the form of a specimen can be measured by stitching several overlapping circular subapertures to form one 3D topography. This concept is very flexible and can be adapted to many different specimen geometries. The sensor is based on a Michelson interferometer configuration that consists of a rapidly oscillating reference mirror in combination with a high-speed line-scan camera. Due to the overlapping areas, movement errors of the scan axes can be corrected. In order to automatically adjust the line sensor in such a way that it is perpendicular to the measurement surface at a fixed working distance, a white-light interferometer was included in the line-based form-measuring system. By means of a fast white-light scan, the optimum angle of the sensor (with respect to the surface of the specimen) is determined in advance, before scanning the specimen using the line-based sinusoidal phase shifting interferometer. This produces accurate measurement results and makes it possible to also measure non-rotational specimens. In this paper, the setup of the line-based form-measuring system is introduced and the measurement strategy of the sensor adjustment using an additional white-light interferometer is presented. Furthermore, the traceability chain of the system and the main error influences are discussed. Examples of form measurement results are shown.

  18. Evaluation of aluminum oxide dosimeters using OSL technique in dosimetry of clinical photon beams on volumetric modulated arc treatment

    International Nuclear Information System (INIS)

    Villani, Daniel

    2017-01-01

    Treatment using Volumetric Modulated Arc Radiation Therapy is the most modern modality of conformational radiotherapy so that, with the overlapping of several fields, the dose distributions provide a perfect conformation to the tumor, reducing the probability of complications in adjacent normal tissues. In this sense, many efforts are being invested to improve dose distribution compliance as well as the integration of imaging techniques for tumor screening and correction of inter and intrafraction variations. To this end, an intensive monitoring of the quality of the processes and a quality assurance program are fundamental for patient safety and compliance with current legislation; besides the use of different dosimetry methodologies for intercomparison and validation of the results. The aim of this study is to evaluate and compare the performance of aluminum oxide (Al_2O_3:C) OSL dosimeters manufactured by Landauer Inc. with those produced by Rexon™ in the dosimetry of high energy photon clinical bundles used in Volumetric Modulated Arc Therapy - (VMAT) using different simulating objects. The dosimeters were characterized for gamma radiation of the "6"0Co and for clinical photon beams of 6 MV typical of treatments by VMAT under conditions of electronic equilibrium and maximum dose respectively. Performance tests of the TL and OSL readers used and repeatability of the samples were evaluated. After all tests, the dosimeters were irradiated in the simulation of different radiotherapy treatments by VMAT and their responses compared to the planning system. All types of dosimeters presented satisfactory results in verifying the doses of this type of planning simulation. The Al_2O_3:C dosimeters presented compatible results and validated by the other dosimeters and ionization chamber. Regarding the best technique, the OSL InLight commercial system presents greater practicality and versatility for use and application in the clinical routine. (author)

  19. Online fibre optic OSL in vivo dosimetry for quality assurance of external beam radiation therapy treatments: The ANR-TECSAN Codofer Project

    International Nuclear Information System (INIS)

    Magne, S.; Ferdinand, P.; De Carlan, L.; Bridier, A.; Isambert, A.; Hugon, R.; Guillon, J.

    2010-01-01

    The Codofer Project (2007-2009), led under the ANR-TECSAN Call, was coordinated by CEA LIST, in partnership with IGR and the Fimel company. The aim of the project was to design and test both metrologically and in clinical conditions OSL optical fiber sensors dedicated to in vivo dosimetry during external beam radiation therapy treatment with high-energy electrons. This study, combined with the results of clinical tests obtained within the European Project Maestro, has demonstrated the advantages of OSL/FO dosimetry for providing quality assurance of treatments. However, the French market for dosimetry has greatly changed as a result of the rules decreed by the French government in 2007. The OSL/FO product is now targeted for other treatment modalities lacking suitable dosimeters (ANR-INTRADOSE Project [2009-2011]). (authors)

  20. An investigation of coseismic OSL / TL time zeroing of quartz gouge based on low- to high-velocity friction experiments

    Science.gov (United States)

    Akasegawa, K.; Oohashi, K.; Hasebe, N.; Miura, K.

    2016-12-01

    To determine an age of coseismic event of an active fault, we generally examine crosscutting relationship between faults and overlying strata by trenching. However, we could not apply this method in case there are no overlying young strata in the vicinity of the fault zones. The alternative is a dating of fault zone materials whose age experienced resetting with seismic fault slip (for example, the ESR method;. Ikeya et al,1982; the OSL and TL methods). The idea behinds to the OSL (optically stimulated luminescence) and TL (thermoluminescence) dating methods for a determination of paleo-earthquake event is the accumulated natural radiation damage becomes to zero (time zeroing) by the frictional heating and grinding. However, physical and geological conditions required to induce time zeroing is not well understood because there is only few experimental investigations under the limited conditions (Hiraga et al,2004;. Kim et al, 2014) . In this study, we conduct low- to high-velocity friction experiments using quartz gouge under various experimental conditions (e.g., normal stress, displacement, moisture content) to establish an empirical relationship and physical and geological conditions of coseismic OSL time zeroing. In this experiment, we carry out the friction experiments using quartz in Tsushigawa granite taken from the east wall of the Nojima fault Ogura trench site, which was excavated in 2015. Samples were taken from the most distant position from the fault in the trench site. The samples were clashed using a mortar and sieved to a grain size of treatment. The residual is user for the friction experiments after having known radiation dose using an artificial gamma-ray source. In this presentation, we show results of the friction experiments and dating of the quartz gouge and discuss physical and geological conditions of OSL time zeroing. References Okumura, T., and Shitaoka, Y., 2011. Engineering Geology of Japan, No. 1, 5-17. Hiraga, S., Yoshimoto, A., and

  1. Dating recent floodplain sediments in the Hawkesbury-Nepean River system, eastern Australia using single-grain quartz OSL

    DEFF Research Database (Denmark)

    Sim, Anna K.; Thomsen, Kristina Jørkov; Murray, K.J.

    2014-01-01

    Two fluvial sediment cores taken from a floodplain of the Hawkesbury-Nepean River system in the Sydney region, eastern Australia are dated using Optically Stimulated Luminescence (OSL) to provide a reliable chronology essential for the management and planning of water resources. Nine charcoal 14C...... in an average apparent age overestimation of ~200 years, which is significant for these samples, but negligible for sediments older than a few thousand years. The intention is that the chronology obtained in this study will be used in conjunction with a proxy flood record, derived from floodplain sediments...

  2. Testing the accuracy of a Bayesian central-dose model for single-grain OSL, using known-age samples

    DEFF Research Database (Denmark)

    Guerin, Guillaume; Combès, Benoit; Lahaye, Christelle

    2015-01-01

    on multi-grain OSL age estimates, these samples are presumed to have been both well-bleached at burial, and unaffected by mixing after deposition. Two ways of estimating single-grain ages are then compared: the standard approach on the one hand, consisting of applying the Central Age Model to De values...... for well-bleached samples; (ii) dose recovery experiments do not seem to be a very reliable tool to estimate the accuracy of a SAR measurement protocol for age determination....

  3. Commissioning optically stimulated luminescence in vivo dosimeters for fast neutron therapy

    Energy Technology Data Exchange (ETDEWEB)

    Young, Lori A., E-mail: layoung@uw.edu; Sandison, George [Department of Radiation Oncology, University of Washington, Seattle, Washington 98115 (United States); Yang, Fei [Sylvester comprehensive Cancer Center, University of Miami, Miami, Florida 33124 (United States); Woodworth, Davis [Department of Physics, University of Reno, Reno, Nevada 89557 (United States); McCormick, Zephyr [Department of Physics, University of California, Santa Barbara, California 93106 (United States)

    2016-01-15

    Purpose: Clinical in vivo dosimeters intended for use with photon and electron therapies have not been utilized for fast neutron therapy because they are highly susceptible to neutron damage. The objective of this work was to determine if a commercial optically stimulated luminescence (OSL) in vivo dosimetry system could be adapted for use in fast neutron therapy. Methods: A 50.5 MeV fast neutron beam generated by a clinical neutron therapy cyclotron was used to irradiate carbon doped aluminum oxide (Al{sub 2}O{sub 3}:C) optically simulated luminescence dosimeters (OSLDs) in a solid water phantom under standard calibration conditions, 150 cm SAD, 1.7 cm depth, and 10.3 × 10.0 cm field size. OSLD fading and electron trap depletion studies were performed with the OSLDs irradiated with 20 and 50 cGy and monitored over a 24-h period to determine the optimal time for reading the dosimeters during calibration. Four OSLDs per group were calibrated over a clinical dose range of 0–150 cGy. Results: OSLD measurement uncertainties were lowered to within ±2%–3% of the expected dose by minimizing the effect of transient fading that occurs with neutron irradiation and maintaining individual calibration factors for each dosimeter. Dose dependent luminescence fading extended beyond the manufacturer’s recommended 10 min period for irradiation with photon or electron beams. To minimize OSL variances caused by inconsistent fading among dosimeters, the observed optimal time for reading the OSLDs postirradiation was between 30 and 90 min. No field size, wedge factor, or gantry angle dependencies were observed in the OSLDs irradiated by the studied fast neutron beam. Conclusions: Measurements demonstrated that uncertainties less than ±3% were attainable in OSLDs irradiated with fast neutrons under clinical conditions. Accuracy and precision comparable to clinical OSL measurements observed with photons can be achieved by maintaining individual OSLD calibration factors and

  4. Optically stimulated luminescence (OSL) from Ag-doped Li{sub 2}B{sub 4}O{sub 7} crystals

    Energy Technology Data Exchange (ETDEWEB)

    Kananen, B.E.; Maniego, E.S.; Golden, E.M.; Giles, N.C.; McClory, J.W. [Department of Engineering Physics, Air Force Institute of Technology, Wright-Patterson Air Force Base, OH 45433 (United States); Adamiv, V.T.; Burak, Ya.V. [Vlokh Institute of Physical Optics, Dragomanov 23, L’viv 79005 (Ukraine); Halliburton, L.E., E-mail: Larry.Halliburton@mail.wvu.edu [Department of Physics and Astronomy, West Virginia University, Morgantown, WV 26506 (United States)

    2016-09-15

    Optically stimulated luminescence (CW-OSL) is observed from Ag-doped lithium tetraborate (Li{sub 2}B{sub 4}O{sub 7}) crystals. Photoluminescence, optical absorption, and electron paramagnetic resonance (EPR) are used to identify the defects participating in the OSL process. As-grown crystals have Ag{sup +} ions substituting for Li{sup +} ions. They also have Ag{sup +} ions occupying interstitial sites. During a room-temperature exposure to ionizing radiation, holes are trapped at the Ag{sup +} ions that replace Li{sup +} ions and electrons are trapped at the interstitial Ag{sup +} ions, i.e., the radiation forms Ag{sup 2+} (4d{sup 9}) ions and Ag{sup 0} (4d{sup 10}5s{sup 1}) atoms. These Ag{sup 2+} and Ag{sup 0} centers have characteristic EPR spectra. The Ag{sup 0} centers also have a broad optical absorption band peaking near 370 nm. An OSL response is observed when the stimulation wavelength overlaps this absorption band. Specifically, stimulation with 400 nm light produces an intense OSL response when emission is monitored near 270 nm. Electrons optically released from the Ag{sup 0} centers recombine with holes trapped at Ag{sup 2+} ions to produce the ultraviolet emission. The OSL response is progressively smaller as the stimulation light is moved to longer wavelengths (i.e., away from the 370 nm peak of the absorption band of the Ag{sup 0} electron traps). Oxygen vacancies are also present in the Ag-doped Li{sub 2}B{sub 4}O{sub 7} crystals, and their role in the OSL process as a secondary relatively short-lived electron trap is described.

  5. OSL-SAR dating of sediments from Brazilian aeolian system: Dama Branca, Rio de Janeiro, morphodynamic study

    International Nuclear Information System (INIS)

    Carmo, Lucas S. do; Watanabe, Shigueo; DeWitt, Regina

    2017-01-01

    It has been reported that the formation and stabilization of coastal dune fields in Brazil have a dependence on the climate changes and Relative Sea Level (RSL) variations. A few topics regarding the morphodynamics of coastal aeolian systems in Brazil can be the RSL variations in the Holocene and weather conditions. In this work, a dune field known as 'Dama Branca', located in the town of Cabo Frio, Rio de Janeiro, has been studied to understand its formation and stabilization. Dating by trapped charge dating techniques as Optically Stimulated Luminescence (OSL) using the Single Aliquot Regenerative protocol (SAR), help to understand the formation and dynamics of aeolian systems in Brazil. Samples from a dune were collected from different heights and points for dating. The results obtained by OSL-SAR showed that ages decrease as the height from the dune base increase and older samples are found in deeper horizontal positions. The ages for the base of the studied dunes indicated that its stabilization occurred during the recess of the sea level. (author)

  6. OSL-SAR dating of sediments from Brazilian aeolian system: Dama Branca, Rio de Janeiro, morphodynamic study

    Energy Technology Data Exchange (ETDEWEB)

    Carmo, Lucas S. do; Watanabe, Shigueo, E-mail: lsatiro@usp.br, E-mail: lacifid@if.usp.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); DeWitt, Regina, E-mail: dewittr@ecu.edu [East Carolina University (ECU), Greenville, NC (United States)

    2017-07-01

    It has been reported that the formation and stabilization of coastal dune fields in Brazil have a dependence on the climate changes and Relative Sea Level (RSL) variations. A few topics regarding the morphodynamics of coastal aeolian systems in Brazil can be the RSL variations in the Holocene and weather conditions. In this work, a dune field known as 'Dama Branca', located in the town of Cabo Frio, Rio de Janeiro, has been studied to understand its formation and stabilization. Dating by trapped charge dating techniques as Optically Stimulated Luminescence (OSL) using the Single Aliquot Regenerative protocol (SAR), help to understand the formation and dynamics of aeolian systems in Brazil. Samples from a dune were collected from different heights and points for dating. The results obtained by OSL-SAR showed that ages decrease as the height from the dune base increase and older samples are found in deeper horizontal positions. The ages for the base of the studied dunes indicated that its stabilization occurred during the recess of the sea level. (author)

  7. A primary assessment of a daybreak 2200 OSL reader using fine grain quartz and CaSO4:Tm TLD

    International Nuclear Information System (INIS)

    Zhang Keqi; Chen Jie; Lu Yanchou; Wang Changsheng; Yang Chuancheng

    2007-01-01

    Daybreak 2200 OSL readers are widely used for luminescence dating applications. As the sample irradiation and illumination may affect discs in adjacent positions, it is critical to confirm that these factors do not introduce significant systematic errors. Effects of cross-irradiation and cross-bleaching were examined and quantified using fine-grain quartz and highly sensitive CaSO 4 :Tm dosimeters, and the irradiation offset time was measured. The cross-bleaching effect on adjacent aliquots is non-linear with no more than 15% OSL signal reduction following 10ks illumination with the power of blue LED being at 95% maximum. But at positions other than the nearest neighboring sample, almost no effect of cross-bleaching was found. The cross-talk dose, even to the nearest samples, was about 0.02% of the applied dose, and it decreased with increasing distance from the source. Offset time of the built-in Beta source shutter is 0.22 s, which can be neglected in regular dating, and leak dose of the source can be ignored as well. Finally, measurement consistency at Position 0.5, 10, ..... and 55 of the sample tray is better than 3% in relative standard deviation. (authors)

  8. Fast harmonic field mapper

    International Nuclear Information System (INIS)

    Au, R.; Fowler, M.; Hanawa, H.; Riedel, J.; Qua, Z.G.

    1984-01-01

    In early 1983 it was decided to mount coils on arms separated by 120 degrees and buck them out so that the third harmonic dphi/dt component would be cancelled and thus the first and second field harmonics could be very accurately measured. The original intention was to do as others had done, namely, use fast ADC's to read the voltages, and computer process the result to get the Fourier components. However, because of the 100 to 1 dynamic range of the fast ADC's and the likelihood that noise would be a problem, the authors decided to do things differently. Using a fast Fourier transform analyzer was considered, but this instrument is very expensive, so they decided to use a completely electronic analog approach: The authors decided to use active bandpass filters to render the harmonic components

  9. Luminescence dating of Pleistocene alluvial sediments affected by the Alhama de Murcia fault (eastern Betics, Spain) – a comparison between OSL, IRSL and post-IRIRSL ages

    DEFF Research Database (Denmark)

    Sohbati, Reza; Murray, Andrew S.; Buylaert, Jan-Pieter

    2012-01-01

    The ages of nine alluvial units, identified by the integration of data obtained from five trenches at the southern termination of the Alhama de Murcia Fault (AMF) (eastern Betics, Spain), are constrained using luminescence dating based on the Optically Stimulated Luminescence (OSL) from quartz...

  10. Persistent luminescence, TL and OSL characterization of beta irradiated SrAl2O4:Eu2+, Dy3+ combustion synthesized phosphor

    International Nuclear Information System (INIS)

    Zúñiga-Rivera, N.J.; García, R.; Rodríguez-Mijangos, R.; Chernov, V.; Meléndrez, R.; Pedroza-Montero, M.; Barboza-Flores, M.

    2014-01-01

    The persistent luminescence (PLUM), thermoluminescence (TL) and optically stimulated luminescence (OSL) properties of strontium aluminates co-doped with Eu +2 and Dy +3 exposed to beta radiation is reported. The phosphor was synthesized by the combustion synthesis method employing a highly exothermic redox reaction between the metal nitrates [Al(NO 3 ) 3 , Sr(NO 3 ) 2 , Eu(NO 3 ) 3 and Dy(NO 3 ) 3 ] and organic fuel carbohydrazide (CH 6 N 4 O). The long decay PLUM emission, TL and OSL were measured as a function of beta radiation dose. A wide emission band centered at 510 nm (green) related to Eu 2+ ions and lattice defects were observed for the synthesized samples. The presence of a variety of defects and aggregates were responsible for the observed broad 100 °C peaked TL glow curve of the irradiated sample which is composed of several overlapped TL peaks. The existence of multiple trapping levels, with different trapping/detrapping probabilities, is behind the particular features for the PLUM, TL and OSL emissions. We conclude that in the SrAl 2 O 4 :Eu 2+ , Dy 3+ phosphors, the low temperature TL peaked around 30–75 °C is responsible for the PLUM emission and those around 100 °C were related to very stable trapping states which provide suitable radiation storage properties to be used as a PLUM/TL/OSL radiation phosphor

  11. Characterization and implementation of OSL dosimeters for use in evaluating the efficacy of organ-based tube current modulation for CT scans of the face and orbits

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, R. M.; Silosky, M., E-mail: michael.silosky@ucdenver.edu [Department of Radiology, University of Colorado School of Medicine, Aurora, Colorado 80045 (United States)

    2015-04-15

    Purpose: The purpose of this work was to characterize commercially available optically stimulated luminescent (OSL) dosimeters for general clinical applications and apply the results to the development of a method to evaluate the efficacy of a vendor-specific organ-based tube current modulation application for both phantom and clinical computed tomography (CT) scans of the face and orbits. Methods: This study consisted of three components: (1) thorough characterization of the dosimeters for CT scans in phantom, including evaluations of depletion, fading, angular dependence, and conversion from counts to absorbed dose; (2) evaluation of the efficacy of using plastic glasses to position the dosimeters over the eyes in both phantom and clinical studies; and (3) preliminary dosimetry measurements made using organ-based tube current modulation in computed tomography dose index (CTDI) and anthropomorphic phantom studies. Results: (1) Depletion effects were found to have a linear relationship with the output of the OSL dosimeters (R{sup 2} = 0.96). Fading was found to affect dosimeter readings during the first two hours following exposure but had no effect during the remaining 60-h period observed. No significant angular dependence was observed for the exposure conditions used in this study (with p-values ranging from 0.9 to 0.26 for all t-tests). Dosimeter counts varied linearly with absorbed dose when measured in the center and 12 o’clock positions of the CTDI phantoms. These linear models of counts versus absorbed dose had overlapping 95% confidence intervals for the intercepts but not for the slopes. (2) When dosimeters were positioned using safety glasses, there was no adverse effect on image quality, and there was no statistically significant difference between this placement and placement of the dosimeters directly on the eyes of the phantom (p = 0.24). (3) When using organ-based tube current modulation, the dose to the lens of the eye was reduced between 19% and

  12. Characterization and implementation of OSL dosimeters for use in evaluating the efficacy of organ-based tube current modulation for CT scans of the face and orbits

    International Nuclear Information System (INIS)

    Marsh, R. M.; Silosky, M.

    2015-01-01

    Purpose: The purpose of this work was to characterize commercially available optically stimulated luminescent (OSL) dosimeters for general clinical applications and apply the results to the development of a method to evaluate the efficacy of a vendor-specific organ-based tube current modulation application for both phantom and clinical computed tomography (CT) scans of the face and orbits. Methods: This study consisted of three components: (1) thorough characterization of the dosimeters for CT scans in phantom, including evaluations of depletion, fading, angular dependence, and conversion from counts to absorbed dose; (2) evaluation of the efficacy of using plastic glasses to position the dosimeters over the eyes in both phantom and clinical studies; and (3) preliminary dosimetry measurements made using organ-based tube current modulation in computed tomography dose index (CTDI) and anthropomorphic phantom studies. Results: (1) Depletion effects were found to have a linear relationship with the output of the OSL dosimeters (R 2 = 0.96). Fading was found to affect dosimeter readings during the first two hours following exposure but had no effect during the remaining 60-h period observed. No significant angular dependence was observed for the exposure conditions used in this study (with p-values ranging from 0.9 to 0.26 for all t-tests). Dosimeter counts varied linearly with absorbed dose when measured in the center and 12 o’clock positions of the CTDI phantoms. These linear models of counts versus absorbed dose had overlapping 95% confidence intervals for the intercepts but not for the slopes. (2) When dosimeters were positioned using safety glasses, there was no adverse effect on image quality, and there was no statistically significant difference between this placement and placement of the dosimeters directly on the eyes of the phantom (p = 0.24). (3) When using organ-based tube current modulation, the dose to the lens of the eye was reduced between 19% and 43

  13. High-resolution OSL chronology of a sediment core from Lake Nam Co on the southern Tibetan Plateau: Comparison with radiocarbon dating

    Science.gov (United States)

    Long, Hao; Shen, Ji; Haberzettl, Torsten; Fuchs, Markus; Frechen, Manfred; Wang, Junbo

    2013-04-01

    Numerous studies on lake sediment cores from the Tibetan Plateau aimed to reconstruct spatial and temporal changes of the late Glacial and Holocene monsoon variations, which are characterized by fluctuations in precipitation and expansion of monsoonal air masses across the Plateau. Accurate and reliable dating of lacustrine deposits is of crucial importance in both the reconstruction of palaeolake and palaeoclimate evolution and the understanding of the mechanisms for climate changes, especially abrupt changes of regional-hemispheric hydrological circulation. Radiocarbon dating is the most commonly used method for establishing chronologies of lake sediments. However, 14C dating of such sediments could be problematic due to the lack of organic matter or a reservoir effect, which appears common in radiocarbon dating of lacustrine sediments from the Tibetan Plateau. In this study, ca. 10.5 m long core (NC core) was retrieved from the water depth of 93 m at Nam Co Lake, which is the second largest saline lake in China, located on the southern Tibetan Plateau. For this core, high-resolution samples (23 samples) were obtained for optically stimulated luminescence (OSL) dating. Quartz of fine-grain (4-11 μm) fraction were extracted from this samples for OSL dating, which is compared with the 14C chronology of NC core based on accelerator mass spectrometry (AMS) dating of bulk organic matter of 22 samples. The sample from the top of NC core was dated to approximate zero age, indicating the sediments bleached well before deposition. Luminescence behaviors of the study samples further confirmed the robustness of OSL ages. Comparison between OSL and 14C ages suggested that: (1) two kinds of ages are in agreement within error from top to 1.8 m, (2) from 1.8 m to the base of NC core, the 14C ages show a general trend to ca. 4 ka higher ages than the OSL ages. Although 14C dating overestimate the ages from 1.8 m to base, they still show the general trend in sedimentation rate

  14. Estimation of identification limit for a small-type OSL dosimeter on the medical images by measurement of X-ray spectra.

    Science.gov (United States)

    Takegami, Kazuki; Hayashi, Hiroaki; Okino, Hiroki; Kimoto, Natsumi; Maehata, Itsumi; Kanazawa, Yuki; Okazaki, Tohru; Hashizume, Takuya; Kobayashi, Ikuo

    2016-07-01

    Our aim in this study is to derive an identification limit on a dosimeter for not disturbing a medical image when patients wear a small-type optically stimulated luminescence (OSL) dosimeter on their bodies during X-ray diagnostic imaging. For evaluation of the detection limit based on an analysis of X-ray spectra, we propose a new quantitative identification method. We performed experiments for which we used diagnostic X-ray equipment, a soft-tissue-equivalent phantom (1-20 cm), and a CdTe X-ray spectrometer assuming one pixel of the X-ray imaging detector. Then, with the following two experimental settings, corresponding X-ray spectra were measured with 40-120 kVp and 0.5-1000 mAs at a source-to-detector distance of 100 cm: (1) X-rays penetrating a soft-tissue-equivalent phantom with the OSL dosimeter attached directly on the phantom, and (2) X-rays penetrating only the soft-tissue-equivalent phantom. Next, the energy fluence and errors in the fluence were calculated from the spectra. When the energy fluence with errors concerning these two experimental conditions was estimated to be indistinctive, we defined the condition as the OSL dosimeter not being identified on the X-ray image. Based on our analysis, we determined the identification limit of the dosimeter. We then compared our results with those for the general irradiation conditions used in clinics. We found that the OSL dosimeter could not be identified under the irradiation conditions of abdominal and chest radiography, namely, one can apply the OSL dosimeter to measurement of the exposure dose in the irradiation field of X-rays without disturbing medical images.

  15. Thermoluminescence dosimetry of electronic components from personal objects

    International Nuclear Information System (INIS)

    Beerten, Koen; Woda, Clemens; Vanhavere, Filip

    2009-01-01

    Owing to the existence of ceramic materials inside common personal objects such as cellular phones and USB flash drives, these objects may be very useful in emergency (accident) dosimetry. Here we will present initial results regarding the dosimetric properties as determined by thermoluminescence (TL) from two alumina-rich electronic components from a USB flash drive. The TL method was applied in order to investigate the potential of conventional TL equipment for such purposes. For comparison, the optically stimulated luminescence (OSL) of the components was investigated as well. The studied components are ceramic resonators and alumina-based substrates from electrical resistors. The results show that various TL-related properties such as fading, optical stability and zero-dose response are different for the two investigated components. On the basis of these properties, the ceramic resonator was selected for dose recovery tests using TL and OSL. The given dose could reliably be determined using both methods, assuming that prompt measurement and/or fading correction is possible.

  16. Stability of fine-grained TT-OSL and post-IR IRSL signals from a c. 1 Ma sequence of aeolian and lacustrine deposits from the Nihewan Basin (northern China)

    DEFF Research Database (Denmark)

    Liu, Jinfeng; Murray, Andrew Sean; Buylaert, Jan-Pieter

    2016-01-01

    We tested the suitability of the fine-grained quartz (4–11 μm) Optical Stimulated Luminescence (OSL) and thermally-transferred OSL (TT-OSL), and the fine-grained polymineral (4–11 μm) post-infrared IRSL (post-IR IRSL or pIRIR) signals for dating samples from aeolian-lacustrine deposits from...... accurate ones; nevertheless, these ages provide the first long series absolute chronology for study of local palaeolithic and geomorphic evolution history aside from the  magnetostratigraphical results available before this research....

  17. Component event data bank fast breeder reactors

    International Nuclear Information System (INIS)

    Cambi, G.; Righini, R.; Sola, P.G.; Zappellini, G.

    1986-01-01

    ENEA, the Italian Committee for Research and Development of Nuclear Energy, has created a data bank expressly concerning FBRs. The structure of the bank is similar to previous CEDB for LWR, but has been fitted to the new requirements typical of FBRs and to the different conditions of the industry. (DG)

  18. Single-grain OSL dating of Early Middle Palaeolithic deposits at Cuesta de la Bajada, Ebro Basin, Spain

    Science.gov (United States)

    Arnold, Lee; Demuro, Martina; Santonja, Manuel; Perez-Gonzalez, Alfredo; Pares, Josep

    2013-04-01

    The open-air site of Cuesta de la Bajada comprises a 2-2.5 m-thick sequence of fluvial-lacustrine sediments inset into the +50-60 m terrace deposits preserved along the south-eastern margins of the Alfambra river valley, Teruel, Spain. The main archaeological horizons lie ~20 m above the present-day river level and consists of an upward-fining sequence of massive fluvial silts and fine sands with dispersed gravels, detritic marls and shales that collectively overlie a series of planar bedded fluvial gravels. These units have yielded ~3000 lithic artefacts displaying reduction techniques characteristic of an early Middle Palaeolithic techno-complex, as well as a multitude of faunal remains indicative of a late Middle Pleistocene origin. The paucity of open-air Palaeolithic sites in the interior eastern sector of the Iberian Peninsula, and the relatively low number of documented early Middle Palaeolithic archives in this region, means that Cuesta de la Bajada is of key importance for understanding the coexistence/transition of Iberian Acheulean and Mousterian techno-complexes during the Middle Pleistocene period. Establishing reliable absolute chronologies at Cuesta de la Bajada remains essential for understanding the regional significance of this site. In an attempt to redress the existing chronological uncertainty we are undertaking an interdisciplinary dating study of the Middle Palaeolithic deposits using OSL dating, ESR/U-series dating of teeth and ESR dating of sedimentary quartz. Here we present results obtained using quartz single-grain OSL dating of 4 samples collected from a 7 m vertical profile bracketing the archaeological horizons. 2 samples were collected from the archaeology-bearing silt and fine sand horizons, while the remaining samples were obtained from well-bedded fine-sands and silts 3.5 m above and 3 m below the main excavation. The measured quartz grains are characterised by relatively bright OSL signals and typically display dose

  19. Existence of a common growth curve for silt-sized quartz OSL of loess from different continents

    International Nuclear Information System (INIS)

    Lai Zhongping; Brueckner, Helmut; Zoeller, Ludwig; Fuelling, Alexander

    2007-01-01

    Recent publications revealed different opinions regarding the existence of a common growth curve (CGC) for OSL of quartz. In the current study, 18 loess samples were collected from four continents (Asia, America, Africa, and Europe) in order to further examine this issue. Except the three samples from Chile in South America, 15 samples display similar dose-response curves up to a regeneration dose of 200 Gy using the SAR protocol, suggesting the existence of a global CGC for loess from different continents. For samples with equivalent doses (D e ) from ∼10 to ∼170Gy, the D e s determined by the CGC are in good agreement with the D e s by the SAR protocol. The Chilean samples posses a growth curve that differs from the CGC, showing much lower saturation doses. We suggest that it may be due to contamination with heavy minerals

  20. A low-cost personal dosemeter based on optically stimulated luminescence (OSL) of common household salt (NaCl)

    International Nuclear Information System (INIS)

    Ekendahl, Daniela; Bulánek, Boris; Judas, Libor

    2016-01-01

    Salt represents a radiation sensitive material that can be used for dosimetry. The objective of this experimental study was to test a low-cost salt dosemeter that was designed for personnel that are not radiation workers, but can operate in low probability events resulting in a serious external radiation exposure. The dosemeter is based on use of optically stimulated luminescence (OSL) of a common household salt. Attention was concentrated on its energy and angular responses. The dosemeter was fixed to the ICRU slab phantom and irradiated by photons of reference radiation qualities (ISO 4037-1) with mean energies between 33 and 1250 keV. Angular response was investigated for angles of incidence from 0° to 80° for radiation qualities of N-150 (∼118 keV) and S-Cs (∼662 keV). Single-Aliquot Regenerative-dose analytical protocol was employed for dose reconstruction. The results were evaluated with respect to H_p(10) measurement. The salt dosemeter can provide reliable or reasonably conservative H_p(10) estimates in radiation fields where photon energies > 100 keV predominate, radiation incidence angles are from 0° to 80° and also for rotational geometry. Furthermore, a personal dose reconstruction trial was demonstrated. Relative deviation between the measured and reference H_p(10) values was 5.5%. A practical disadvantage of the method is the more demanding analytical protocol. - Highlights: • Common salt has a considerable potential for dosimetry based on use of OSL. • A simple salt personal dosemeter was designed and tested. • Photon energy and angular responses were satisfactory for purposes of accidental dosimetry. • Dose reconstruction trial proved the potential for reliable estimate of personal doses.

  1. Comparative study on fast classification of brick samples by combination of principal component analysis and linear discriminant analysis using stand-off and table-top laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Vítková, Gabriela [Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5/A14, 625 00 Brno (Czech Republic); Prokeš, Lubomír [Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5/A14, 625 00 Brno (Czech Republic); Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno (Czech Republic); CEPLANT, R and D Center for Low-Cost Plasma and Nanotechnology Surface Modifications, Masaryk University, Kotlářská 2, 611 37 Brno (Czech Republic); Novotný, Karel [Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5/A14, 625 00 Brno (Czech Republic); CEITEC — Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno (Czech Republic); Pořízka, Pavel [Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technická 2896/2, 616 69 Brno (Czech Republic); Novotný, Jan [CEITEC — Central European Institute of Technology, Brno University of Technology, Technická 3058/10, 616 00 Brno (Czech Republic); Všianský, Dalibor [Department of Geological Sciences, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno (Czech Republic); Čelko, Ladislav [CEITEC — Central European Institute of Technology, Brno University of Technology, Technická 3058/10, 616 00 Brno (Czech Republic); and others

    2014-11-01

    Focusing on historical aspect, during archeological excavation or restoration works of buildings or different structures built from bricks it is important to determine, preferably in-situ and in real-time, the locality of bricks origin. Fast classification of bricks on the base of Laser-Induced Breakdown Spectroscopy (LIBS) spectra is possible using multivariate statistical methods. Combination of principal component analysis (PCA) and linear discriminant analysis (LDA) was applied in this case. LIBS was used to classify altogether the 29 brick samples from 7 different localities. Realizing comparative study using two different LIBS setups — stand-off and table-top it is shown that stand-off LIBS has a big potential for archeological in-field measurements. - Highlights: • Comparison of two potentially field-deployable LIBS setups is introduced. • The aim is classification of LIBS spectra of brick samples into several localities. • LDA filled with PCA scores is proposed as an effective classification method. • An influence of brick firing temperature on LIBS spectra is discovered and examined.

  2. SU-F-T-327: Total Body Irradiation In-Vivo Dose Measurements Using Optically Stimulated Luminescence (OSL) NanoDots and Farmer Type Ion Chamber

    International Nuclear Information System (INIS)

    Kaur, H; Kumar, S; Sarkar, B; Ganesh, T; Giri, U; Jassal, K; Rathinamuthu, S; Gulia, G; Gopal, V; Mohanti, B; Munshi, A

    2016-01-01

    Purpose: This study was performed to analyze the agreement between optically stimulated luminescence (OSL) nanoDots measured doses and 0.6 cc Farmer type ionization chamber measured doses during total body irradiation (TBI). Methods: In-vivo dose measurements using OSL nanoDots and Farmer chamber were done in a total of twelve patients who received TBI at our center by bilateral parallel-opposed beams technique. In this technique, the patient is kept inside the TBI box which is filled with rice bags and irradiated using two bilateral parallel opposed beams of 40×40 cm"2 size with 45° collimator rotation at an SSD of 333.5 cm in an Elekta Synergy linear accelerator. All patients received a dose of 2 Gy in single fraction as conditioning regimen. The beams were equally weighted at the midplane of the box. The nanoDots were placed over forehead, right and left neck, right and left lung, umbilicus, right and left abdomen, medial part of thigh, knee and toe. A 0.6 cc Farmer chamber was placed in between the thighs of the patient. Measured doses are reported along with the statistical comparisons using paired sample t-test. Results: For the above sites the mean doses were 212.2±21.1, 218.2±7.6, 218.7±9.3, 215.6±9.5, 217.5±11.5, 214.5±7.7, 218.3±6.8, 221.5±15, 229.1±11.0, 220.5±7.7 and 223.3±5.1 cGy respectively. For all OSL measurements the mean dose was 218.6±11.8 cGy. Farmer chamber measurements yielded a mean dose of 208.8±15.6 cGy. Statistical analysis revealed that there was no significant difference between OSL measured doses in forehead, right and left neck, right and left lung, umbilicus, right and left abdomen and toe and Farmer chamber measured doses (0.72≤p≤0.06). However the mean OSL doses at thigh and knee were statistically different (p<0.05) from the Farmer chamber measurements. Conclusion: OSL measurements were found to be in agreement with Farmer type ionization chamber measurements in in-vivo dosimetry of TBI.

  3. SU-F-T-327: Total Body Irradiation In-Vivo Dose Measurements Using Optically Stimulated Luminescence (OSL) NanoDots and Farmer Type Ion Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, H; Kumar, S; Sarkar, B; Ganesh, T; Giri, U; Jassal, K; Rathinamuthu, S; Gulia, G; Gopal, V; Mohanti, B; Munshi, A [Fortis Memorial Research Institute, Gurgaon, Haryana (India)

    2016-06-15

    Purpose: This study was performed to analyze the agreement between optically stimulated luminescence (OSL) nanoDots measured doses and 0.6 cc Farmer type ionization chamber measured doses during total body irradiation (TBI). Methods: In-vivo dose measurements using OSL nanoDots and Farmer chamber were done in a total of twelve patients who received TBI at our center by bilateral parallel-opposed beams technique. In this technique, the patient is kept inside the TBI box which is filled with rice bags and irradiated using two bilateral parallel opposed beams of 40×40 cm{sup 2} size with 45° collimator rotation at an SSD of 333.5 cm in an Elekta Synergy linear accelerator. All patients received a dose of 2 Gy in single fraction as conditioning regimen. The beams were equally weighted at the midplane of the box. The nanoDots were placed over forehead, right and left neck, right and left lung, umbilicus, right and left abdomen, medial part of thigh, knee and toe. A 0.6 cc Farmer chamber was placed in between the thighs of the patient. Measured doses are reported along with the statistical comparisons using paired sample t-test. Results: For the above sites the mean doses were 212.2±21.1, 218.2±7.6, 218.7±9.3, 215.6±9.5, 217.5±11.5, 214.5±7.7, 218.3±6.8, 221.5±15, 229.1±11.0, 220.5±7.7 and 223.3±5.1 cGy respectively. For all OSL measurements the mean dose was 218.6±11.8 cGy. Farmer chamber measurements yielded a mean dose of 208.8±15.6 cGy. Statistical analysis revealed that there was no significant difference between OSL measured doses in forehead, right and left neck, right and left lung, umbilicus, right and left abdomen and toe and Farmer chamber measured doses (0.72≤p≤0.06). However the mean OSL doses at thigh and knee were statistically different (p<0.05) from the Farmer chamber measurements. Conclusion: OSL measurements were found to be in agreement with Farmer type ionization chamber measurements in in-vivo dosimetry of TBI.

  4. New fast reactor installation concept

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    The large size and complexity of fast reactor installations are emphasised and these difficulties will be increased with the advent of fast reactors of higher power. In this connection a new concept of fast reactor installation is described with a view to reducing the size of the installation and enabling most components, including even the primary vessel, to be constructed within the confines of a workshop. Full constructional details are given. (U.K.)

  5. Comparative study of different Al_2O_3:C dosimeters using OSL technique for dosimetry on Volumetric Modulated Arc Radiotherapy Treatment (VMAT)

    International Nuclear Information System (INIS)

    Villani, Daniel; Campos, LetIcia L.; Mancini, Anselmo; Haddad, Cecilia M.K.

    2016-01-01

    In modern radiotherapy, the VMAT technique has become a successful treatment alternative. Due to its complexity, a quality assurance program must be established by evaluating, among other items, the dosimetric factors. This paper aims to compare the performance between the OSL aluminum oxide (Al_2O_3:C) nanoDot™ dosimeters (Inlight™ system) manufactured by Landauer Inc. and TLD-500 Al_2O_3:C dosimeters manufactured by Rexon™ for VMAT dosimetry using an anthropomorphic phantom. The results showed that both type of Al_2O_3:C dosimeters presented good repeatability and agreement between the doses measured and calculated by planning system. However, the need of sophisticated readers to OSL analysis of the TLD-500, turns it less practical for routine usage, comparing to Inlight™ system. (author)

  6. PIXE multivariate statistics and OSL investigation for the classification and dating of archaeological pottery excavated at Tell Al-Rawda site, Syria

    Energy Technology Data Exchange (ETDEWEB)

    Bakraji, E.H., E-mail: cscientificl@aec.org.sy [Archaeometry Laboratory, Chemistry Department, Atomic Energy Commission of Syria, P. O. Box 6091, Damascus (Syrian Arab Republic); Rihawy, M.S. [Archaeometry Laboratory, Chemistry Department, Atomic Energy Commission of Syria, P. O. Box 6091, Damascus (Syrian Arab Republic); Castel, C. [CNRS – Maison de l’Orient et de la Méditerranée, Laboratoire “Archéorient”, CNRS/Université Lumière-Lyon 2 (France); Abboud, R. [Archaeometry Laboratory, Chemistry Department, Atomic Energy Commission of Syria, P. O. Box 6091, Damascus (Syrian Arab Republic)

    2015-03-15

    Highlights: •PIXE and OSL methods were used to classify and date pottery from Tell Al-Rawda site. •Three groups were classified using PIXE, which suggest different sources of the clay. •OSL was used for dating the site and the date found was consistent with typology. -- Abstract: Particle Induced X-ray Emission (PIXE) technique has been utilised to study 48 Syrian ancient pottery fragments taken from excavations at Tell Al-Rawda site. Eighteen elements (Mg, Al, Si, P, S, K, Ca, Ti, Mn, Fe, Ni, Zn, As, Br, Rb, Sr, Y, and Pb) were determined. The elements concentrations have been processed using two multivariate statistical methods, to classify the pottery where one main group and other two small groups were defined. In addition, four samples from different places on the site were subjected to optically stimulated luminescence (OSL) dating. The average age obtained using a single aliquot regeneration (SAR) protocol was found to be 4350 ± 240 year.

  7. Establishing a luminescence chronology for a palaeosol-loess profile at Tokaj (Hungary): A comparison of quartz OSL and polymineral IRSL signals

    DEFF Research Database (Denmark)

    Schatz, Ann-Kathrin; Buylaert, Jan-Pieter; Murray, Andrew

    2012-01-01

    We present a comparative study of quartz OSL, polymineral IRSL at low temperature (50 °C, IR50) and post-IR elevated temperature (290 °C) IRSL (pIRIR290) feldspar dating on nine samples from the Tokaj loess section in NE Hungary (SE Europe). Preheat plateau tests show a drop in quartz OSL De...... between 160 and 240 °C but above 240 °C a clear De plateau is present. Quartz OSL SAR is shown to be generally appropriate to these samples (recycling, recuperation) but a satisfactory dose recovery result was only obtained when a dose was added to a sample without any prior optical or thermal pre...... of the Tokaj loess has been deposited during MIS 3 (60–24 ka), with periods of soil formation occurring during the onset of MIS 3 (≥58 ka) and between about 35 and 25 ka. Our results also indicate episodic deposition of loess and varying, non-linear sedimentation rates during MIS 3. Proxy analyses...

  8. PIXE multivariate statistics and OSL investigation for the classification and dating of archaeological pottery excavated at Tell Al-Rawda site, Syria

    International Nuclear Information System (INIS)

    Bakraji, E.H.; Rihawy, M.S.; Castel, C.; Abboud, R.

    2015-01-01

    Highlights: •PIXE and OSL methods were used to classify and date pottery from Tell Al-Rawda site. •Three groups were classified using PIXE, which suggest different sources of the clay. •OSL was used for dating the site and the date found was consistent with typology. -- Abstract: Particle Induced X-ray Emission (PIXE) technique has been utilised to study 48 Syrian ancient pottery fragments taken from excavations at Tell Al-Rawda site. Eighteen elements (Mg, Al, Si, P, S, K, Ca, Ti, Mn, Fe, Ni, Zn, As, Br, Rb, Sr, Y, and Pb) were determined. The elements concentrations have been processed using two multivariate statistical methods, to classify the pottery where one main group and other two small groups were defined. In addition, four samples from different places on the site were subjected to optically stimulated luminescence (OSL) dating. The average age obtained using a single aliquot regeneration (SAR) protocol was found to be 4350 ± 240 year

  9. Sources of uncertainties in OSL dating of archaeological mortars: The case study of the Roman amphitheatre “Palais-Gallien” in Bordeaux

    International Nuclear Information System (INIS)

    Urbanova, P.; Hourcade, D.; Ney, C.; Guibert, P.

    2015-01-01

    Archaeological mortars are more convenient and much more representative for the chronology of buildings than brick or wood constructions that can be re-used from older buildings. Before dating unknown samples of mortars, further investigation of OSL from mortars is required and the most efficient methodology needs to be established. In this study we compared the ages obtained by OSL dating of quartz extracted from mortars of the Roman amphitheatre Palais-Gallien in Bordeaux with independent age information. Resetting of the OSL signal occurred during the preparation of mortar when grains of sand (quartz) were extracted and mixed with lime and water. The mortar was subsequently hidden from light by embedding within the structure which is the event to be dated. Various factors contribute to uncertainties in the age determination. The frequency of measured equivalent doses reveals a large scattering. Optical bleaching of certain grains can be partial due to the short duration of the exposure to light. We worked with the single grain technique in order to find and select the grains that were sufficiently exposed to daylight. To determine the average equivalent dose, we tried three different approaches: a calculation of an arithmetic mean and one following either the central age model or the 3-parameter minimum age model, the latter turned out to be the only relevant way to evaluate the experimental data. The proportion of grains included in the calculation of the average equivalent dose represents 2.7–4.7 % of the overall analysed grains. The results obtained for the three out of four samples are approaching the expected age, however, the minimum doses and the corresponding ages are significantly over-estimated in case of two samples. The studied material is very coarse, which causes heterogeneity of irradiation at the single grain scale, and contributes to a dispersion of equivalent doses. Different analytical methods (scanning electron microscopy with energy

  10. Euler principal component analysis

    NARCIS (Netherlands)

    Liwicki, Stephan; Tzimiropoulos, Georgios; Zafeiriou, Stefanos; Pantic, Maja

    Principal Component Analysis (PCA) is perhaps the most prominent learning tool for dimensionality reduction in pattern recognition and computer vision. However, the ℓ 2-norm employed by standard PCA is not robust to outliers. In this paper, we propose a kernel PCA method for fast and robust PCA,

  11. Investigation of the response characteristics of OSL albedo neutron dosimeters in a 241AmBe reference neutron field

    Science.gov (United States)

    Liamsuwan, T.; Wonglee, S.; Channuie, J.; Esoa, J.; Monthonwattana, S.

    2017-06-01

    The objective of this work was to systematically investigate the response characteristics of optically stimulated luminescence Albedo neutron (OSLN) dosimeters to ensure reliable personal dosimetry service provided by Thailand Institute of Nuclear Technology (TINT). Several batches of InLight® OSLN dosimeters were irradiated in a reference neutron field generated by the in-house 241AmBe neutron irradiator. The OSL signals were typically measured 24 hours after irradiation using the InLight® Auto 200 Reader. Based on known values of delivered neutron dose equivalent, the reading correction factor to be used by the reader was evaluated. Subsequently, batch homogeneity, dose linearity, lower limit of detection and fading of the OSLN dosimeters were examined. Batch homogeneity was evaluated to be 0.12 ± 0.05. The neutron dose response exhibited a linear relationship (R2=0.9974) within the detectable neutron dose equivalent range under test (0.4-3 mSv). For this neutron field, the lower limit of detection was between 0.2 and 0.4 mSv. Over different post-irradiation storage times of up to 180 days, the readings fluctuated within ±5%. Personal dosimetry based on the investigated OSLN dosimeter is considered to be reliable under similar neutron exposure conditions, i.e. similar neutron energy spectra and dose equivalent values.

  12. Stepped-irradiation SAR: A viable approach to circumvent OSL equivalent dose underestimation in last glacial loess of northwestern China

    International Nuclear Information System (INIS)

    Qin, J.T.; Zhou, L.P.

    2009-01-01

    The equivalent dose (D e ) obtained with the continuous irradiation SAR (CI-SAR) protocol for fine-grained quartz from loess of northwestern China is found to be lower than the expected value for samples older than 70 ka based on the regional stratigraphy. This is attributed to the difference in the response of the quartz to natural radiation and laboratory beta irradiation whose rates vary by ∼10 8 times. A stepped irradiation SAR protocol was employed to evaluate the influence of such a 'dose rate effect' on the equivalent dose determination. After investigating the effects of thermal treatment and 'unit-dose' on OSL signal and D e , we refined the stepped irradiation strategy with a 'unit-dose' of ∼25 Gy and successive thermal treatments at 250 deg. C for 10 s, and applied it to the SAR protocol. This stepped irradiation SAR (SI-SAR) protocol led to a 20%-70% increase in D e value for loess deposited during the early last glacial period.

  13. Computerised curve deconvolution of TL/OSL curves using a popular spreadsheet program.

    Science.gov (United States)

    Afouxenidis, D; Polymeris, G S; Tsirliganis, N C; Kitis, G

    2012-05-01

    This paper exploits the possibility of using commercial software for thermoluminescence and optically stimulated luminescence curve deconvolution analysis. The widely used software package Microsoft Excel, with the Solver utility has been used to perform deconvolution analysis to both experimental and reference glow curves resulted from the GLOw Curve ANalysis INtercomparison project. The simple interface of this programme combined with the powerful Solver utility, allows the analysis of complex stimulated luminescence curves into their components and the evaluation of the associated luminescence parameters.

  14. Computerised curve deconvolution of TL/OSL curves using a popular spreadsheet program

    International Nuclear Information System (INIS)

    Afouxenidis, D.; Polymeris, G. S.; Tsirliganis, N. C.; Kitis, G.

    2012-01-01

    This paper exploits the possibility of using commercial software for thermoluminescence and optically stimulated luminescence curve deconvolution analysis. The widely used software package Microsoft Excel, with the Solver utility has been used to perform deconvolution analysis to both experimental and reference glow curves resulted from the Glow Curve Analysis Intercomparison project. The simple interface of this programme combined with the powerful Solver utility, allows the analysis of complex stimulated luminescence curves into their components and the evaluation of the associated luminescence parameters. (authors)

  15. Fast reactor programme

    International Nuclear Information System (INIS)

    Plakman, J.C.

    1982-01-01

    This progress report summarizes the fast reactor research carried out by ECN during the period covering the year 1980. This research is mainly concerned with the cores of sodium-cooled breeders, in particular the SNR-300, and its related safety aspects. It comprises six items: A programme to determine relevant nuclear data of fission- and corrosion-products; A fuel performance programme comprising in-pile cladding failure experiments and a study of the consequences of loss-of-cooling and overpower; Basic research on fuel; Investigation of the changes in the mechanical properties of austenitic stainless steel DIN 1.4948 due to fast neutron doses, this material has been used in the manufacture of the reactor vessel and its internal components; Study of aerosols which could be formed at the time of a fast reactor accident and their progressive behaviour on leaking through cracks in the concrete containment; Studies on heat transfer in a sodium-cooled fast reactor core. As fast breeders operate at high power densities, an accurate knowledge of the heat transfer phenomena under single-phase and two-phase conditions is sought. (Auth.)

  16. Fast reactors

    International Nuclear Information System (INIS)

    Vasile, A.

    2001-01-01

    Fast reactors have capacities to spare uranium natural resources by their breeding property and to propose solutions to the management of radioactive wastes by limiting the inventory of heavy nuclei. This article highlights the role that fast reactors could play for reducing the radiotoxicity of wastes. The conversion of 238 U into 239 Pu by neutron capture is more efficient in fast reactors than in light water reactors. In fast reactors multi-recycling of U + Pu leads to fissioning up to 95% of the initial fuel ( 238 U + 235 U). 2 strategies have been studied to burn actinides: - the multi-recycling of heavy nuclei is made inside the fuel element (homogeneous option); - the unique recycling is made in special irradiation targets placed inside the core or at its surroundings (heterogeneous option). Simulations have shown that, for the same amount of energy produced (400 TWhe), the mass of transuranium elements (Pu + Np + Am + Cm) sent to waste disposal is 60,9 Kg in the homogeneous option and 204.4 Kg in the heterogeneous option. Experimental programs are carried out in Phenix and BOR60 reactors in order to study the feasibility of such strategies. (A.C.)

  17. Fast ejendom

    DEFF Research Database (Denmark)

    Pagh, Peter

    Bogen omfatter en gennemgang af lovgivning, praksis og teori vedrørende køb af fast ejendom og offentligretlig og privatretlig regulering. Bogen belyser bl.a. de privatretlige emner: købers misligholdelsesbeføjelser, servitutter, naboret, hævd og erstatningsansvar for miljøskader samt den...

  18. Comparative study of different Al{sub 2}O{sub 3}:C dosimeters using OSL technique for dosimetry on Volumetric Modulated Arc Radiotherapy Treatment (VMAT); Estudo comparativo de diferentes dosimetros de Al{sub 2}O{sub 3}:C pela tecnica OSL na dosimetria de tratamentos Radioterapicos por Arco Modulado Volumetrico (VMAT)

    Energy Technology Data Exchange (ETDEWEB)

    Villani, Daniel; Campos, LetIcia L., E-mail: dvillani@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Mancini, Anselmo; Haddad, Cecilia M.K. [Hospital Sirio-Libanes, Sao Paulo, SP (Brazil). Centro de Radioterapia

    2016-07-01

    In modern radiotherapy, the VMAT technique has become a successful treatment alternative. Due to its complexity, a quality assurance program must be established by evaluating, among other items, the dosimetric factors. This paper aims to compare the performance between the OSL aluminum oxide (Al{sub 2}O{sub 3}:C) nanoDot™ dosimeters (Inlight™ system) manufactured by Landauer Inc. and TLD-500 Al{sub 2}O{sub 3}:C dosimeters manufactured by Rexon™ for VMAT dosimetry using an anthropomorphic phantom. The results showed that both type of Al{sub 2}O{sub 3}:C dosimeters presented good repeatability and agreement between the doses measured and calculated by planning system. However, the need of sophisticated readers to OSL analysis of the TLD-500, turns it less practical for routine usage, comparing to Inlight™ system. (author)

  19. Preliminary results of chronostratigraphic field work, OSL-dating and morphogenetic reconstruction of an alluvial apron at Alborz southern foothill, Damghan basin, Iran

    Science.gov (United States)

    Büdel, Christian; Fuchs, Markus; Majid Padashi, Seyed; Baumhauer, Roland

    2014-05-01

    Here we present preliminary results of a chronostratigraphic study of an alluvial fan in the Damghan Basin, northern Iran. The basin sediments date back to the Mio- and Pliocene and therefore represent the starting point of alluvial fan aggradation. Today, the still active alluvial fans prograde from the Albors Mountain ranges and sit on the older sediment bodies. In this study, our focus is on the late Pleistocene to Holocene alluvial fan sedimentation history. The upper stratigraphy of the alluvial fans and intercalated lake deposits is characterized by six individual layers of gravels and fines, representing six different stratigraphic units. These units are described and classified by detailed geomorphological and stratigraphic mapping. To establish an alluvial fan chronology, six profiles were sampled for OSL dating. As expected, due to the high-energy transport system of alluvial fan aggradation in semi-desert environments, OSL dating of these sediments is challenging due to the problem of insufficient bleaching. Consequently, most of the samples are interpreted as maximum ages. However, the measurements show a consistent internal age structure and the overall OSL-based chronology is in agreement with the age model derived from our geomorphological analysis. As a first interpretation, based on surveyed geomorphological features and chronological analysis, we could identify seven morphodynamic phases, leading to a genetic model of alluvial fan aggradation. The oldest Pleistocene age estimate is derived from a former lake terrace. The following ages represent ongoing lake sediment deposition and the development of a proximal and mid-fan gravel cover. After the youngest lake deposits were accumulated within the Holocene, the lake starts to retreat and small alluvial fans are filling up the former lake bottom. This last sedimentation phase can be divided in at least two sub-phases, probably coupled to a lateral shifting of the active depositional lobe and to the

  20. Energy dependence measurement of small-type optically stimulated luminescence (OSL) dosimeter by means of characteristic X-rays induced with general diagnostic X-ray equipment.

    Science.gov (United States)

    Takegami, Kazuki; Hayashi, Hiroaki; Okino, Hiroki; Kimoto, Natsumi; Maehata, Itsumi; Kanazawa, Yuki; Okazaki, Tohru; Hashizume, Takuya; Kobayashi, Ikuo

    2016-01-01

    For X-ray inspections by way of general X-ray equipment, it is important to measure an entrance-skin dose. Recently, a small optically stimulated luminescence (OSL) dosimeter was made commercially available by Landauer, Inc. The dosimeter does not interfere with the medical images; therefore, it is expected to be a convenient detector for measuring personal exposure doses. In an actual clinical situation, it is assumed that X-rays of different energies will be detected by a dosimeter. For evaluation of the exposure dose measured by a dosimeter, it is necessary to know the energy dependence of the dosimeter. Our aim in this study was to measure the energy dependence of the OSL dosimeter experimentally in the diagnostic X-ray region. Metal samples weighing several grams were irradiated and, in this way, characteristic X-rays having energies ranging from 8 to 85 keV were generated. Using these mono-energetic X-rays, the dosimeter was irradiated. Simultaneously, the fluence of the X-rays was determined with a CdTe detector. The energy-dependent efficiency of the dosimeter was derived from the measured value of the dosimeter and the fluence. Moreover, the energy-dependent efficiency was calculated by Monte-Carlo simulation. The efficiency obtained in the experiment was in good agreement with that of the simulation. In conclusion, our proposed method, in which characteristic X-rays are used, is valuable for measurement of the energy dependence of a small OSL dosimeter in the diagnostic X-ray region.

  1. Sources of variability in OSL dose measurements using single grains of quartz

    International Nuclear Information System (INIS)

    Thomsen, K.J.; Murray, A.S.; Boetter-Jensen, L.

    2005-01-01

    In luminescence-based measurements of dose distributions in unheated mineral samples, the observed spread in dose values is usually attributed to four main factors: fluctuations in the number of photons counted, incomplete zeroing of any prior trapped charge (including signals arising from thermal transfer), heterogeneity in dosimetry, and instrument reproducibility. For correct interpretation of measured dose distributions in retrospective dosimetry, it is important to understand the relative importance of these components, and to establish whether other factors also contribute to the observed spread. In this preliminary study, dose distributions have been studied using single grains of heated and laboratory irradiated quartz. By heating the sample, the contribution from incomplete zeroing was excluded and at the same time the sample was sensitised. The laboratory gamma irradiation was designed to deliver a uniform dose to the sample. Thus it was anticipated that statistical fluctuations in the number of photons counted and instrument reproducibility, both quantifiable entities, should be able to account for all the observed variance in the measured dose distributions. We examine this assumption in detail, and discuss the origins and importance of the residual variance in our data

  2. Estimation of identification limit for a small-type OSL dosimeter on the medical images by measurement of X-ray spectra

    OpenAIRE

    Takegami, Kazuki ; Hayashi, Hiroaki; Okino, Hiroki; Kimoto, Natsumi ; Maehata, Itsumi ; Kanazawa, Yuki ; Okazaki, Tohru ; Hashizume, Takuya ; Kobayashi, Ikuo 

    2016-01-01

    Our aim in this study is to derive an identification limit on a dosimeter for not disturbing a medical image when patients wear a small-type optically stimulated luminescence (OSL) dosimeter on their bodies during X-ray diagnostic imaging. For evaluation of the detection limit based on an analysis of X-ray spectra, we propose a new quantitative identification method. We performed experiments for which we used diagnostic X-ray equipment, a soft-tissue-equivalent phantom (1–20 cm), and a CdTe X...

  3. Fast tomosynthesis

    International Nuclear Information System (INIS)

    Klotz, E.; Linde, R.; Tiemens, U.; Weiss, H.

    1978-01-01

    A system has been constructed for fast tomosynthesis, whereby X-ray photographs are made of a single layer of an object. Twenty five X-ray tubes illuminate the object simultaneously at different angles. The resulting coded image is decoded by projecting it with a pattern of lenses that have the same form as the pattern of X-ray tubes. The coded image is optically correlated with the pattern of the sources. The scale of this can be adjusted so that the desired layer of the object is portrayed. Experimental results of its use in a hospital are presented. (C.F.)

  4. Fast Flux Test Facility

    International Nuclear Information System (INIS)

    Munn, W.I.

    1981-01-01

    The Fast Flux Test Facility (FFTF), located on the Hanford site a few miles north of Richland, Washington, is a major link in the chain of development required to sustain and advance Liquid Metal Fast Breeder Reactor (LMFBR) technology in the United States. This 400 MWt sodium cooled reactor is a three loop design, is operated by Westinghouse Hanford Company for the US Department of Energy, and is the largest research reactor of its kind in the world. The purpose of the facility is three-fold: (1) to provide a test bed for components, materials, and breeder reactor fuels which can significantly extend resource reserves; (2) to produce a complete body of base data for the use of liquid sodium in heat transfer systens; and (3) to demonstrate inherent safety characteristics of LMFBR designs

  5. Other components

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    This chapter includes descriptions of electronic and mechanical components which do not merit a chapter to themselves. Other hardware requires mention because of particularly high tolerance or intolerance of exposure to radiation. A more systematic analysis of radiation responses of structures which are definable by material was given in section 3.8. The components discussed here are field effect transistors, transducers, temperature sensors, magnetic components, superconductors, mechanical sensors, and miscellaneous electronic components

  6. Application of the optically stimulated luminescence (OSL) technique for mouse dosimetry in micro-CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Vrigneaud, Jean-Marc; Courteau, Alan; Oudot, Alexandra; Collin, Bertrand [Department of Nuclear Medicine, Centre Georges-François Leclerc, 1 rue Professeur Marion, Dijon 21079 Cedex (France); Ranouil, Julien [Landauer Europe, 33 avenue du Général Leclerc, Fontenay-aux-Roses 92266 Cedex (France); Morgand, Loïc; Raguin, Olivier [Oncodesign, 20 rue Jean Mazen, Dijon 21076 Cedex (France); Walker, Paul [LE2i CNRS UMR 5158, Faculty of Medicine, BP 87900, 21079 Dijon Cedex (France); Brunotte, François [Department of Nuclear Medicine, Centre Georges-François Leclerc, 1 rue Professeur Marion, Dijon 21079 Cedex, France and LE2i CNRS UMR 5158, Faculty of Medicine, BP 87900, 21079 Dijon Cedex (France)

    2013-12-15

    Purpose: Micro-CT is considered to be a powerful tool to investigate various models of disease on anesthetized animals. In longitudinal studies, the radiation dose delivered by the micro-CT to the same animal is a major concern as it could potentially induce spurious effects in experimental results. Optically stimulated luminescence dosimeters (OSLDs) are a relatively new kind of detector used in radiation dosimetry for medical applications. The aim of this work was to assess the dose delivered by the CT component of a micro-SPECT (single-photon emission computed tomography)/CT camera during a typical whole-body mouse study, using commercially available OSLDs based on Al{sub 2}O{sub 3}:C crystals.Methods: CTDI (computed tomography dose index) was measured in micro-CT with a properly calibrated pencil ionization chamber using a rat-like phantom (60 mm in diameter) and a mouse-like phantom (30 mm in diameter). OSLDs were checked for reproducibility and linearity in the range of doses delivered by the micro-CT. Dose measurements obtained with OSLDs were compared to those of the ionization chamber to correct for the radiation quality dependence of OSLDs in the low-kV range. Doses to tissue were then investigated in phantoms and cadavers. A 30 mm diameter phantom, specifically designed to insert OSLDs, was used to assess radiation dose over a typical whole-body mouse imaging study. Eighteen healthy female BALB/c mice weighing 27.1 ± 0.8 g (1 SD) were euthanized for small animal measurements. OLSDs were placed externally or implanted internally in nine different locations by an experienced animal technician. Five commonly used micro-CT protocols were investigated.Results: CTDI measurements were between 78.0 ± 2.1 and 110.7 ± 3.0 mGy for the rat-like phantom and between 169.3 ± 4.6 and 203.6 ± 5.5 mGy for the mouse-like phantom. On average, the displayed CTDI at the operator console was underestimated by 1.19 for the rat-like phantom and 2.36 for the mouse

  7. Replaceable LMFBR core components

    International Nuclear Information System (INIS)

    Evans, E.A.; Cunningham, G.W.

    1976-01-01

    Much progress has been made in understanding material and component performance in the high temperature, fast neutron environment of the LMFBR. Current data have provided strong assurance that the initial core component lifetime objectives of FFTF and CRBR can be met. At the same time, this knowledge translates directly into the need for improved core designs that utilize improved materials and advanced fuels required to meet objectives of low doubling times and extended core component lifetimes. An industrial base for the manufacture of quality core components has been developed in the US, and all procurements for the first two core equivalents for FFTF will be completed this year. However, the problem of fabricating recycled plutonium while dramatically reducing fabrication costs, minimizing personnel exposure, and protecting public health and safety must be addressed

  8. Assessing sedimentation rates at Usumacinta and Grijalva river basin (Southern Mexico) using OSL and suspended sediment load analysis: A study from the Maya Classic Period

    Science.gov (United States)

    Munoz-Salinas, E.; Castillo, M.; Sanderson, D.; Kinnaird, T.; Cruz-Zaragoza, E.

    2013-12-01

    Studying sedimentation rates on floodplains is key to understanding environmental changes occurred through time in river basins. The Usumacinta and Grijalva rivers flow most of their travel through the southern part of Mexico, forming a large river basin, crossing the states of Chiapas and Tabasco. The Usumacinta-Grijalva River Basin is within the 10 major rivers of North America, having a basin area of ~112 550 km2. We use the OSL technique for dating two sediment profiles and for obtaining luminescence signals in several sediment profiles located in the streambanks of the main trunk of the Usumacinta and Grijalva rivers. We also use mean annual values of suspended sediment load spanning ~50 years to calculate the sedimentation rates. Our OSL dating results start from the 4th Century, when the Maya Civilization was at its peak during the Classic Period. Sedimentation rates show a notable increase at the end of the 19th Century. The increase of the sedimentation rates seems to be related to changes in land uses in the Sierra Madre de Chiapas and Altos de Chiapas, based on deforestation and land clearing for developing new agrarian and pastoral activities. We conclude that the major environmental change in the basin of the Usumacinta and Grijalva Rivers since the Maya Classic Period was generated since the last Century as a result of an intense anthropogenic disturbance of mountain rain forest in Chiapas.

  9. Electronic components

    CERN Document Server

    Colwell, Morris A

    1976-01-01

    Electronic Components provides a basic grounding in the practical aspects of using and selecting electronics components. The book describes the basic requirements needed to start practical work on electronic equipment, resistors and potentiometers, capacitance, and inductors and transformers. The text discusses semiconductor devices such as diodes, thyristors and triacs, transistors and heat sinks, logic and linear integrated circuits (I.C.s) and electromechanical devices. Common abbreviations applied to components are provided. Constructors and electronics engineers will find the book useful

  10. 2-component heating systems

    Energy Technology Data Exchange (ETDEWEB)

    Radtke, W

    1987-03-01

    The knowledge accumulated only recently of the damage to buildings and the hazards of formaldehyde, radon and hydrocarbons has been inducing louder calls for ventilation, which, on their part, account for the fact that increasing importance is being attached to the controlled ventilation of buildings. Two-component heating systems provide for fresh air and thermal comfort in one. While the first component uses fresh air blown directly and controllably into the rooms, the second component is similar to the Roman hypocaustic heating systems, meaning that heated outer air is circulating under the floor, thus providing for hot surfaces and thermal comfort. Details concerning the two-component heating system are presented along with systems diagrams, diagrams of the heating system and tables identifying the respective costs. Descriptions are given of the two systems components, the fast heat-up, the two-component made, the change of air, heat recovery and control systems. Comparative evaluations determine the differences between two-component heating systems and other heating systems. Conclusive remarks are dedicated to energy conservation and comparative evaluations of costs. (HWJ).

  11. Radiation dose response correlation between thermoluminescence and optically stimulated luminescence in quartz

    International Nuclear Information System (INIS)

    Oniya, E.O.; Polymeris, G.S.; Tsirliganis, N.C.; Kitis, G.

    2012-01-01

    The fast, linearly modulated optically stimulated luminescence (LM-OSL) component in quartz is the main dosimetric signal used for the dating applications of this material. Since the blue light stimulation (470 nm, 40 mW cm −2 ) time needed to obtain the fast LM-OSL component is less than 50 s the electron trapping levels responsible for it are still highly populated. In this way an active radiation history is created which could play an important role in the dosimetric characteristics of the fast OSL signal. In the present work the dose response behavior of the fast OSL signal is investigated in quartz samples with an annealed radiation history and quartz samples possessing an artificial radiation history. A computerized curve de-convolution analysis of the LM-OSL curves for 50 s stimulation time showed that it consists of three individual OSL components. The faster component C 1 with peak maximum time around 5 s has a linear dose response in virgin samples, which turns to a slight superlinearity as a function of the artificial radiation history. On the other hand the component C 2 with peak maximum time at 12 s is slightly superlinear which turns into strong superlinearity as a function of artificial radiation history. Finally, component C 3 with peak maximum time at about 45 s is strongly superlinear for both virgin samples and as a function of artificial radiation history. The implications to practical application are discussed. - Highlights: ► The fast OSL component consists of three components. ► The linearity of first fast component does not depend on radiation history. ► The linearity of second and third components depend on radiation history. ► The TL between 180 and 300 °C is the major source of OSL.

  12. Synthesis and TL/OSL properties of a novel high-sensitive blue-emitting LiSrPO{sub 4}:Eu{sup 2+} phosphor for radiation dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Palan, C.B.; Koparkar, K.A.; Omanwar, S.K. [Sant Gadge Baba Amravati University, Department of Physics, Amravati (India); Bajaj, N.S. [Toshniwal Arts, Commerce and Science College, Sengoan, Hingoli District, MH (India); Soni, A. [Bhabha Atomic Research Centre, Radiological Physics and Advisory Division, Mumbai (India)

    2016-07-15

    In this study, a series of Eu{sup 2+}-doped LiSrPO{sub 4} phosphors were synthesized via solid-state method. The structural and morphological characterizations were done through X-ray diffraction and scanning electronic microscope. Additionally, the photoluminescence (PL), thermoluminescence (TL) and optically stimulated luminescence (OSL) behaviours of LiSrPO{sub 4}:Eu{sup 2+} phosphors were studied. The LiSrPO{sub 4}:Eu{sup 2+} phosphor shows OSL sensitivity about 8 times than that of α-Al{sub 2}O{sub 3}:C phosphor and 6 times than that of LiMgPO{sub 4}:Tb{sup 3+}, B phosphor. Moreover, TL sensitivity was about 15 times more as compared to α-Al{sub 2}O{sub 3}:C phosphor. The kinetic parameters of TL curve were calculated using peak shape method. In TL/OSL mode, dose-response was almost linear nature, in the range of measurement. The minimum detectable dose was found to be 25.18 μGy with 3σ of background. Also, reusability was also studies, which shows the phosphor can be reusable for 10 cycles with 0.1 % change in OSL output. (orig.)

  13. A silicon diode for fast neutron dosimetry

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    The effect of fast neutrons on both animate and inanimate objects, including human beings, can be extremely serious and cumulative. There is thus a need for a small, simple and cheap component which will provide a permanent or semi-permanent record of the accumulated fast neutron dose

  14. Design codes for fast reactor steam generators

    International Nuclear Information System (INIS)

    Townley, C.H.A.

    1978-01-01

    The paper reviews the design methods and design criteria which are available for fast reactor structures, and discusses the materials data which are required to demonstrate the integrity of the plant components. (author)

  15. New age estimations for the western outer city wall of ancient Tayma (NW Saudi Arabia) based on OSL and radiocarbon data and geomorphologic evidence

    Science.gov (United States)

    Engel, M.; Klasen, N.; Brückner, H.; Eichmann, R.; Hausleiter, A.; Al-Najem, M. H.; Al-Said, S. F.; Schneider, P. I.

    2009-04-01

    Since 2004 tremendous progress has been achieved in deciphering the cultural genesis of the Tayma oasis (NW Saudi Arabia), due to the joint investigations of the German Archaeological Institute Berlin (DAI), the General Commission for Tourism and Antiquities, Kingdom of Saudi Arabia, and the Department of Archaeology and Epigraphy, King Saud University Riyadh. Nevertheless, archaeological research is still suffering from a lacking locally-based absolute chronology of buildings. The pattern of ancient constructions at Tayma is dominated by a prominent city wall system surrounding the ancient town center (Qraya) and stretching 15 km around the oasis. Its internal structure indicates several building periods, i.e. phases of wall modification or extension of the entire system. So far, according to silex and carnelian fragments included in the mud bricks and a previous 14C age of charcoal remains from the central excavation district (wall section at Area A), an initial construction date of the wall between the late 3rd and the early 2nd millennium BC seemed likely. At the excavated western outer city wall a new systematic dating approach - combining the optically stimulated luminescence (OSL) and 14C methods - has been applied to generate a reliable age for the oldest branch of the wall system which nowadays is covered by aeolian sand. The dune deposit is genetically related to the existence of the wall and, therefore, dating its accumulation provides termini ante quem for the construction of the wall. Five OSL dates were generated from the dune deposit providing ages between 4,900 and 3,500 yrs. Two radiocarbon ages support the dating sequence and also contribute to its consistency. By combining the results with geomorphologic evidence we draw the following conclusions: Initial settlement activities at Qraya were accompanied by a regulation of wadi dynamics and the construction of the outer city wall, indicated by the abrupt boundary between the pre-settlement alluvial

  16. Evaluation of aluminum oxide dosimeters using OSL technique in dosimetry of clinical photon beams on volumetric modulated arc treatment; Avaliacao de dosimetros de oxido de aluminio pela tecnica OSL na dosimetria de campos de fotons clinicos utilizados no tratamento radioterapico em arco modulado volumetrico

    Energy Technology Data Exchange (ETDEWEB)

    Villani, Daniel

    2017-07-01

    Treatment using Volumetric Modulated Arc Radiation Therapy is the most modern modality of conformational radiotherapy so that, with the overlapping of several fields, the dose distributions provide a perfect conformation to the tumor, reducing the probability of complications in adjacent normal tissues. In this sense, many efforts are being invested to improve dose distribution compliance as well as the integration of imaging techniques for tumor screening and correction of inter and intrafraction variations. To this end, an intensive monitoring of the quality of the processes and a quality assurance program are fundamental for patient safety and compliance with current legislation; besides the use of different dosimetry methodologies for intercomparison and validation of the results. The aim of this study is to evaluate and compare the performance of aluminum oxide (Al{sub 2}O{sub 3}:C) OSL dosimeters manufactured by Landauer Inc. with those produced by Rexon™ in the dosimetry of high energy photon clinical bundles used in Volumetric Modulated Arc Therapy - (VMAT) using different simulating objects. The dosimeters were characterized for gamma radiation of the {sup 60}Co and for clinical photon beams of 6 MV typical of treatments by VMAT under conditions of electronic equilibrium and maximum dose respectively. Performance tests of the TL and OSL readers used and repeatability of the samples were evaluated. After all tests, the dosimeters were irradiated in the simulation of different radiotherapy treatments by VMAT and their responses compared to the planning system. All types of dosimeters presented satisfactory results in verifying the doses of this type of planning simulation. The Al{sub 2}O{sub 3}:C dosimeters presented compatible results and validated by the other dosimeters and ionization chamber. Regarding the best technique, the OSL InLight commercial system presents greater practicality and versatility for use and application in the clinical routine

  17. Fast Convolution Module (Fast Convolution Module)

    National Research Council Canada - National Science Library

    Bierens, L

    1997-01-01

    This report describes the design and realisation of a real-time range azimuth compression module, the so-called 'Fast Convolution Module', based on the fast convolution algorithm developed at TNO-FEL...

  18. Optically stimulated luminescence of electronic components for forensic, retrospective, and accident dosimetry

    International Nuclear Information System (INIS)

    Inrig, E.L.; Godfrey-Smith, D.I.; Khanna, S.

    2008-01-01

    This study investigated the optically stimulated luminescence (OSL) response of electronic components found within portable electronic devices such as cell phones and pagers, portable computers, music and video players, global positioning system receivers, cameras, and digital watches. The analysis of components extracted from these ubiquitous devices was proposed for applications ranging from rapid accident dose reconstruction to the tracking and attribution of gamma-emitting radiological materials. Surface-mount resistors with alumina porcelain substrates consistently produced OSL following irradiation, with minimum detectable doses on the order of 10 mGy for a typical sample. Since the resistor ceramics were found to exhibit anomalous fading, dose reconstruction procedures were developed to correct for this using laboratory measurements of fading rates carried out over approximately 3 months. Two trials were conducted in which cellular phones were affixed to an anthropomorphic phantom and irradiated using gamma-ray sources; ultimately, analysis of the devices used in these trials succeeded in reconstructing doses in the range of 0.1-0.6Gy

  19. An integrated OSL chronology, sedimentology and geochemical approach to loess deposits from Tuoji Island, Shandong Province: Implications for the late quaternary paleoenvironment in East China

    Science.gov (United States)

    Xu, Shujian; Kong, Fanbiao; Jia, Guangju; Miao, Xiaodong; Ding, Xinchao

    2018-04-01

    The Tuoji II (TJII) section on the Miaodao Islands in the Bohai Sea is a representative aeolian section off China's east coast. This study applied optically stimulated luminescence (OSL) dating, conducted grain size analysis, and examined major and trace element compositions, to investigate the loess-paleosol sequences. The OSL ages at depths of 0.6, 1.8, 2.8, 3.8, and 4.8 m were determined as 14.4 ± 0.4, 16.7 ± 1.3, 20.8 ± 1.0, 40.9 ± 1.5, and 47.9 ± 3.7 ka, respectively. It was projected that the loess started to accumulate at ca. 62.6 ka, according to presumed depositional rates. In this study, typical aeolian deposits elsewhere including the Luochuan (LC), Xiashu (XS), Wushan (WS), and Xifeng (XF) sections were compared with TJII section here. The results showed similarity in the geochemical characteristics of the deposits from the different areas of China and normalized upper continental crust, indicating aeolian origin of this island loess. In comparison with the LC, XS, WS, and XF samples, the aeolian deposits of the TJII section have higher concentrations of TiO2 and Zr and lower concentrations of Al2O3, Rb, and Ni, and they have higher SiO2/Al2O3 and TiO2/Al2O3 ratios and lower Al2O3/Na2O and Ba/Sr ratios. These features indicate the dust materials of the TJII section were derived from local sources of well-mixed sedimentary protoliths. Our results support the suggestion that paleoclimatic change and the evolution of aeolian sediments were controlled primarily by variation of the East Asian summer monsoon and sea level change.

  20. FAST: FAST Analysis of Sequences Toolbox

    Directory of Open Access Journals (Sweden)

    Travis J. Lawrence

    2015-05-01

    Full Text Available FAST (FAST Analysis of Sequences Toolbox provides simple, powerful open source command-line tools to filter, transform, annotate and analyze biological sequence data. Modeled after the GNU (GNU’s Not Unix Textutils such as grep, cut, and tr, FAST tools such as fasgrep, fascut, and fastr make it easy to rapidly prototype expressive bioinformatic workflows in a compact and generic command vocabulary. Compact combinatorial encoding of data workflows with FAST commands can simplify the documentation and reproducibility of bioinformatic protocols, supporting better transparency in biological data science. Interface self-consistency and conformity with conventions of GNU, Matlab, Perl, BioPerl, R and GenBank help make FAST easy and rewarding to learn. FAST automates numerical, taxonomic, and text-based sorting, selection and transformation of sequence records and alignment sites based on content, index ranges, descriptive tags, annotated features, and in-line calculated analytics, including composition and codon usage. Automated content- and feature-based extraction of sites and support for molecular population genetic statistics makes FAST useful for molecular evolutionary analysis. FAST is portable, easy to install and secure thanks to the relative maturity of its Perl and BioPerl foundations, with stable releases posted to CPAN. Development as well as a publicly accessible Cookbook and Wiki are available on the FAST GitHub repository at https://github.com/tlawrence3/FAST. The default data exchange format in FAST is Multi-FastA (specifically, a restriction of BioPerl FastA format. Sanger and Illumina 1.8+ FastQ formatted files are also supported. FAST makes it easier for non-programmer biologists to interactively investigate and control biological data at the speed of thought.

  1. The new ATLAS Fast Calorimeter Simulation

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00223142; The ATLAS collaboration

    2017-01-01

    Current and future need for large scale simulated samples motivate the development of reliable fast simulation techniques. The new Fast Calorimeter Simulation is an improved parameterized response of single particles in the ATLAS calorimeter that aims to accurately emulate the key features of the detailed calorimeter response as simulated with Geant4, yet approximately ten times faster. Principal component analysis and machine learning techniques are used to improve the performance and decrease the memory need compared to the current version of the ATLAS Fast Calorimeter Simulation. A prototype of this new Fast Calorimeter Simulation is in development and its integration into the ATLAS simulation infrastructure is ongoing.

  2. The new ATLAS Fast Calorimeter Simulation

    Science.gov (United States)

    Schaarschmidt, J.; ATLAS Collaboration

    2017-10-01

    Current and future need for large scale simulated samples motivate the development of reliable fast simulation techniques. The new Fast Calorimeter Simulation is an improved parameterized response of single particles in the ATLAS calorimeter that aims to accurately emulate the key features of the detailed calorimeter response as simulated with Geant4, yet approximately ten times faster. Principal component analysis and machine learning techniques are used to improve the performance and decrease the memory need compared to the current version of the ATLAS Fast Calorimeter Simulation. A prototype of this new Fast Calorimeter Simulation is in development and its integration into the ATLAS simulation infrastructure is ongoing.

  3. Principal components

    NARCIS (Netherlands)

    Hallin, M.; Hörmann, S.; Piegorsch, W.; El Shaarawi, A.

    2012-01-01

    Principal Components are probably the best known and most widely used of all multivariate analysis techniques. The essential idea consists in performing a linear transformation of the observed k-dimensional variables in such a way that the new variables are vectors of k mutually orthogonal

  4. Two component memory of Rotstein effect in nuclear emulsions

    International Nuclear Information System (INIS)

    Gushchin, E.M.; Lebedev, A.N.; Somov, S.V.; Timofeev, M.K.; Tipografshchik, G.I.

    1991-01-01

    Two sharply differing memory components - fast and slow -are simultaneously detected during investigation into the controlled mode of fast charged particle detection in simple nuclear emulsions, with the emulsion trace sensitivity, corresponding to these components, being about 5 time different. The value of memory time is T m ≅40 μs for fast memory and T m ≅3.5 ms for the slow one. The detection of two Rotstein effect memory components confirms the correctness of the trap model

  5. Material choices for the commercial fast reactor steam generators

    International Nuclear Information System (INIS)

    Willby, C.; Walters, J.

    1978-01-01

    Experience with fast reactor steam generators has shown them to be critical components in achieving a high availability. This paper presents the designers views on the use of ferritic materials for steam generators and describes the proposed design of the steam generators for the Commercial Fast Reactor (CFR), prototype of which are to be inserted in the Prototype Fast Reactor at Dounreay. (author)

  6. A review of the UK fast reactor programme

    International Nuclear Information System (INIS)

    Smith, R.D.

    1982-01-01

    A review of the United Kingdom Fast Reactor Programme is introduced. Operational experience with the Prototype Fast Reactor (PFR) is briefly summarized. The design concept of the Commercial Demonstration Fast Reactor (CDFR) is given in some detail. The emphasis is on materials development, chemical engineering/sodium technology, fuel reprocessing and fuel cycle, engineering component development and reactor safety

  7. Fasting and rheumatic diseases

    OpenAIRE

    Mohammad Hassan Jokar

    2015-01-01

    Fasting is one of the important religious practices of Muslims, in which the individuals abstain from eating and drinking from dawn to sunset. Fasting is not obligatory or even not allowed, in case it causes health problems to the fasting individual. Rheumatic diseases are a major group of chronic diseases which can bring about numerous problems while fasting. The aim of this article is to review the impact of Islamic fasting on rheumatic patients, based on the scientific evidences.

  8. Persistent luminescence, TL and OSL characterization of beta irradiated SrAl{sub 2}O{sub 4}:Eu{sup 2+}, Dy{sup 3+} combustion synthesized phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Zúñiga-Rivera, N.J. [Departamento de Física, Posgrado en Nanotecnología, Universidad de Sonora, Hermosillo, Sonora 83000 (Mexico); García, R.; Rodríguez-Mijangos, R.; Chernov, V.; Meléndrez, R.; Pedroza-Montero, M. [Departamento de Investigación en Física, Universidad de Sonora, Hermosillo, Sonora 83000 (Mexico); Barboza-Flores, M., E-mail: mbarboza@cifus.uson.mx [Departamento de Investigación en Física, Universidad de Sonora, Hermosillo, Sonora 83000 (Mexico)

    2014-05-01

    The persistent luminescence (PLUM), thermoluminescence (TL) and optically stimulated luminescence (OSL) properties of strontium aluminates co-doped with Eu{sup +2} and Dy{sup +3} exposed to beta radiation is reported. The phosphor was synthesized by the combustion synthesis method employing a highly exothermic redox reaction between the metal nitrates [Al(NO{sub 3}){sub 3}, Sr(NO{sub 3}){sub 2}, Eu(NO{sub 3}){sub 3} and Dy(NO{sub 3}){sub 3}] and organic fuel carbohydrazide (CH{sub 6}N{sub 4}O). The long decay PLUM emission, TL and OSL were measured as a function of beta radiation dose. A wide emission band centered at 510 nm (green) related to Eu{sup 2+} ions and lattice defects were observed for the synthesized samples. The presence of a variety of defects and aggregates were responsible for the observed broad 100 °C peaked TL glow curve of the irradiated sample which is composed of several overlapped TL peaks. The existence of multiple trapping levels, with different trapping/detrapping probabilities, is behind the particular features for the PLUM, TL and OSL emissions. We conclude that in the SrAl{sub 2}O{sub 4}:Eu{sup 2+}, Dy{sup 3+} phosphors, the low temperature TL peaked around 30–75 °C is responsible for the PLUM emission and those around 100 °C were related to very stable trapping states which provide suitable radiation storage properties to be used as a PLUM/TL/OSL radiation phosphor.

  9. Intracavitary in vivo dosimetry based on multichannel fiber-coupled optically stimulated luminescence (OSL) of Al2O3:C for Curietherapy

    International Nuclear Information System (INIS)

    Spasic, Estelle

    2012-01-01

    The brachytherapy is an old technique using sealed radioactive sources of low or average energy. This technique is still therapeutically and economically relevant today and always evolving (e.g. High Dose Rate (HDR) brachytherapy). This treatment enables to deliver a high dose of irradiation in a limited tumoral volume and enables to minimize the risk of radiation-induced cancer as preserving the Organs at Risks (OAR). However, this technique generates high dose gradients, which makes in vivo dosimetry difficult to implement. Hence, the deviations observed between doses delivered and prescribed are often up to the maximal deviation tolerated by the nuclear safety regulations (± 5%) in conformational radiotherapy. Those regulations have been made mandatory in France since 2011. This thesis has been done within the framework of the ANR-TECSAN INTRADOSE project and is based on the past technological benefits demonstrated during the MAESTRO European project and the ANR-TECSAN CODOFER project, in particular a RL/OSL multichannel instrumentation (Radioluminescence - Optically Stimulated Luminescence) made and validated in preclinical evaluation during the MAESTRO project. The purpose of the INTRADOSE project is to demonstrate the feasibility of the intracavitary In Vivo Dosimetry (IVD) by dosimetric catheter using optical fibers and alumina crystals Al 2 O 3 :C with the aim of improving the safety of patients treated by HDR brachytherapy. This new probe enables to measure a dose distribution (several points) close to the OAR, it offers a little diameter (≤ 3 mm) designed for an intracavitary use (e.g. to insert in the urethra), it is transparent, radiation stable and reusable after dose reading and sterilization. During this study, we have first developed this new dosimetric sensor based on the OSL using the properties of the alumina crystal. Several tests have been done in order to evaluate the feasibility and the compatibility with a medical application. Then

  10. Fast reactor database. 2006 update

    International Nuclear Information System (INIS)

    2006-12-01

    Liquid metal cooled fast reactors (LMFRs) have been under development for about 50 years. Ten experimental fast reactors and six prototype and commercial size fast reactor plants have been constructed and operated. In many cases, the overall experience with LMFRs has been rather good, with the reactors themselves and also the various components showing remarkable performances, well in accordance with the design expectations. The fast reactor system has also been shown to have very attractive safety characteristics, resulting to a large extent from the fact that the fast reactor is a low pressure system with large thermal inertia and negative power and temperature coefficients. In addition to the LMFRs that have been constructed and operated, more than ten advanced LMFR projects have been developed, and the latest designs are now close to achieving economic competitivity with other reactor types. In the current world economic climate, the introduction of a new nuclear energy system based on the LMFR may not be considered by utilities as a near future option when compared to other potential power plants. However, there is a strong agreement between experts in the nuclear energy field that, for sustainability reasons, long term development of nuclear power as a part of the world's future energy mix will require the fast reactor technology, and that, given the decline in fast reactor development projects, data retrieval and knowledge preservation efforts in this area are of particular importance. This publication contains detailed design data and main operational data on experimental, prototype, demonstration, and commercial size LMFRs. Each LMFR plant is characterized by about 500 parameters: physics, thermohydraulics, thermomechanics, by design and technical data, and by relevant sketches. The focus is on practical issues that are useful to engineers, scientists, managers, university students and professors with complete technical information of a total of 37 LMFR

  11. HCUP Fast Stats

    Data.gov (United States)

    U.S. Department of Health & Human Services — HCUP Fast Stats provides easy access to the latest HCUP-based statistics for health information topics. HCUP Fast Stats uses visual statistical displays in...

  12. Fast food (image)

    Science.gov (United States)

    Fast foods are quick, reasonably priced, and readily available alternatives to home cooking. While convenient and economical for a busy lifestyle, fast foods are typically high in calories, fat, saturated fat, ...

  13. Fast food tips (image)

    Science.gov (United States)

    ... challenge to eat healthy when going to a fast food place. In general, avoiding items that are deep ... challenge to eat healthy when going to a fast food place. In general, avoiding items that are deep ...

  14. Fast-track hip and knee arthroplasty

    DEFF Research Database (Denmark)

    Husted, Henrik

    2012-01-01

    Fast-track hip and knee arthroplasty aims at giving the patients the best available treatment at all times, being a dynamic entity. Fast-track combines evidence-based, clinical features with organizational optimization including a revision of traditions resulting in a streamlined pathway from...... on clinical and organizational aspects of fast-track hip and knee arthroplasty (I–IX). A detailed description of the fast-track set-up and its components is provided. Major results include identification of patient characteristics to predict length of stay and satisfaction with different aspects...... of the hospital stay (I); how to optimize analgesia by using a compression bandage in total knee arthroplasty (II); the clinical and organizational set-up facilitating or acting as barriers for early discharge (III); safety aspects following fast-track in the form of few readmissions in general (IV) and few...

  15. Fast Access Data Acquisition System (FADAS)

    International Nuclear Information System (INIS)

    Katsman, Vladimir

    1998-01-01

    Our goal in this program is to develop Fast Access Data Acquisition System (FADAS) by combining the flexibility of Multilink's GaAs and InP electronics and electro-optics with an extremely high data rate for the efficient handling and transfer of collider experimental data. This novel solution is based on Multilink's and Los Alamos National Laboratory's (LANL) unique components and technologies for extremely fast data transfer, storage, and processing

  16. The behaviour of materials in fast reactors

    International Nuclear Information System (INIS)

    Matthews, J.R.

    1977-01-01

    Fast neutron damage in fast reactors can limit the life of structural components through the growth voids. The main features of the current theory of point defect production and condensation are surveyed. The role of metallurgical structures and radiation produced extended defects is outlined and used to demonstrate the development of volume swelling and radiation hardening. Mechanisms of radiation creep are described in the context of the preceding treatment of point defect behaviour. Finally, future trends in the field are briefly explored. (author)

  17. General remarks on fast neutron reactor physics

    International Nuclear Information System (INIS)

    Barre, J.Y.

    1980-01-01

    The main aspects of fast reactor physics, presented in these lecture notes, are restricted to LMFBR's. The emphasis is placed on the core neutronic balance and the burn-up problems. After a brief description of the power reactor main components and of the fast reactor chronology, the fundamental parameters of the one-group neutronic balance are briefly reviewed. Then the neutronic burn-up problems related to the Pu production and to the doubling time are considered

  18. Physiology of Ramadan fasting

    OpenAIRE

    Shokoufeh Bonakdaran

    2016-01-01

    Considering the emphasis of Islam on the importance of fasting, Muslims attempt to fast from dawn until sunset during the holy month of Ramadan. Fasting is associated with several benefits for normal and healthy individuals. However, it could pose high risks to the health of diabetic patients due to certain physiological changes. This study aimed to compare the physiological changes associated with fasting in healthy individuals and diabetic patients during Ramadan. Furthermore, we reviewed t...

  19. The prototype fast reactor

    International Nuclear Information System (INIS)

    Broomfield, A.M.

    1985-01-01

    The paper concerns the Prototype Fast Reactor (PFR), which is a liquid metal cooled fast reactor power station, situated at Dounreay, Scotland. The principal design features of a Fast Reactor and the PFR are given, along with key points of operating history, and health and safety features. The role of the PFR in the development programme for commercial reactors is discussed. (U.K.)

  20. The fast reactor

    International Nuclear Information System (INIS)

    1980-02-01

    The subject is discussed as follows: brief description of fast reactors; advantage in conserving uranium resources; experience, in UK and elsewhere, in fast reactor design, construction and operation; safety; production of plutonium, security aspects; consideration of future UK fast reactor programme. (U.K.)

  1. Ramadan, fasting and pregnancy

    DEFF Research Database (Denmark)

    Ahmed, Urfan Zahoor; Lykke, Jacob Alexander

    2014-01-01

    In Islam, the month of Ramadan is a period of fasting lasting 29 or 30 days. Epidemiological studies among Muslims in Denmark have not been conducted, but studies show, that fasting among pregnant Muslim women is common. Fasting does not increase the risk of growth restriction or preterm delivery...

  2. Enhanced Model for Fast Ignition

    Energy Technology Data Exchange (ETDEWEB)

    Mason, Rodney J. [Research Applications Corporation, Los Alamos, NM (United States)

    2010-10-12

    Laser Fusion is a prime candidate for alternate energy production, capable of serving a major portion of the nation's energy needs, once fusion fuel can be readily ignited. Fast Ignition may well speed achievement of this goal, by reducing net demands on laser pulse energy and timing precision. However, Fast Ignition has presented a major challenge to modeling. This project has enhanced the computer code ePLAS for the simulation of the many specialized phenomena, which arise with Fast Ignition. The improved code has helped researchers to understand better the consequences of laser absorption, energy transport, and laser target hydrodynamics. ePLAS uses efficient implicit methods to acquire solutions for the electromagnetic fields that govern the accelerations of electrons and ions in targets. In many cases, the code implements fluid modeling for these components. These combined features, "implicitness and fluid modeling," can greatly facilitate calculations, permitting the rapid scoping and evaluation of experiments. ePLAS can be used on PCs, Macs and Linux machines, providing researchers and students with rapid results. This project has improved the treatment of electromagnetics, hydrodynamics, and atomic physics in the code. It has simplified output graphics, and provided new input that avoids the need for source code access by users. The improved code can now aid university, business and national laboratory users in pursuit of an early path to success with Fast Ignition.

  3. Rapid and cyclic dust accumulation during MIS 2 in Central Asia inferred from loess OSL dating and grain-size analysis.

    Science.gov (United States)

    Li, Yun; Song, Yougui; Lai, Zhongping; Han, Li; An, Zhisheng

    2016-09-02

    Due to lack of reliable proxies from the Westerlies-dominant region, the strength change of Northern Hemisphere Westerlies remains poorly understood. The aim of this study is to provide a reliable paleoclimatic proxy about the Northern Hemisphere Westerlies change. Here we report a 30.7 m thick loess section from the Ili basin directly controlled by the Westerlies. Based on optically stimulated luminescence (OSL) and high resolution grain-size records, we reconstruct the change history of the Westerlies strength during the last glacial period (mainly Marine Isotope Stages 2, MIS2), being similar with the Westerlies index recorded in the Qinghai Lake sediments. Within error limits, all ages are in stratigraphic order. We further compare the climatic records among the Ili loess, Qinghai Lake and the NGRIP, their similarity shows a good climatic coupling relationship among the Central Asia, East Asia and the North Atlantic, and the Westerlies plays a critical influence in transporting the North Atlantic signal to Central and East Asia.

  4. Ramadan, fasting and pregnancy

    DEFF Research Database (Denmark)

    Ahmed, Urfan Zahoor; Lykke, Jacob Alexander

    2014-01-01

    In Islam, the month of Ramadan is a period of fasting lasting 29 or 30 days. Epidemiological studies among Muslims in Denmark have not been conducted, but studies show, that fasting among pregnant Muslim women is common. Fasting does not increase the risk of growth restriction or preterm delivery......, but there are reports of decreased foetal movements. Furthermore, the fasting may have long-term health consequences for the offspring, especially when they reach their middle age. According to Islam and the interpretation, pregnant and breast-feeding women are allowed to postpone the fasting of the month of Ramadan...

  5. Ramadan, faste og graviditet

    DEFF Research Database (Denmark)

    Ahmed, Urfan Zahoor; Lykke, Jacob Alexander

    2014-01-01

    In Islam, the month of Ramadan is a period of fasting lasting 29 or 30 days. Epidemiological studies among Muslims in Denmark have not been conducted, but studies show, that fasting among pregnant Muslim women is common. Fasting does not increase the risk of growth restriction or preterm delivery......, but there are reports of decreased foetal movements. Furthermore, the fasting may have long-term health consequences for the offspring, especially when they reach their middle age. According to Islam and the interpretation, pregnant and breast-feeding women are allowed to postpone the fasting of the month of Ramadan...

  6. Passive Microwave Components and Antennas

    DEFF Research Database (Denmark)

    State-of-the-art microwave systems always require higher performance and lower cost microwave components. Constantly growing demands and performance requirements of industrial and scientific applications often make employing traditionally designed components impractical. For that reason, the design...... and development process remains a great challenge today. This problem motivated intensive research efforts in microwave design and technology, which is responsible for a great number of recently appeared alternative approaches to analysis and design of microwave components and antennas. This book highlights...... techniques. Modelling and computations in electromagnetics is a quite fast-growing research area. The recent interest in this field is caused by the increased demand for designing complex microwave components, modeling electromagnetic materials, and rapid increase in computational power for calculation...

  7. Emergency dose estimation using optically stimulated luminescence from human tooth enamel

    International Nuclear Information System (INIS)

    Sholom, S.; DeWitt, R.; Simon, S.L.; Bouville, A.; McKeever, S.W.S.

    2011-01-01

    Human teeth were studied for potential use as emergency Optically Stimulated Luminescence (OSL) dosimeters. By using multiple-teeth samples in combination with a custom-built sensitive OSL reader, 60 Co-equivalent doses below 0.64 Gy were measured immediately after exposure with the lowest value being 27 mGy for the most sensitive sample. The variability of OSL sensitivity, from individual to individual using multiple-teeth samples, was determined to be 53%. X-ray and beta exposure were found to produce OSL curves with the same shape that differed from those due to ultraviolet (UV) exposure; as a result, correlation was observed between OSL signals after X-ray and beta exposure and was absent if compared to OSL signals after UV exposure. Fading of the OSL signal was 'typical' for most teeth with just a few of incisors showing atypical behavior. Typical fading dependences were described by a bi-exponential decay function with 'fast' (decay time around of 12 min) and 'slow' (decay time about 14 h) components. OSL detection limits, based on the techniques developed to-date, were found to be satisfactory from the point of view of medical triage requirements if conducted within 24 h of the exposure.

  8. Emergency dose estimation using optically stimulated luminescence from human tooth enamel

    Energy Technology Data Exchange (ETDEWEB)

    Sholom, S., E-mail: sergey.sholom@okstate.edu [Oklahoma State University, Stillwater, OK (United States); DeWitt, R. [Oklahoma State University, Stillwater, OK (United States); Simon, S.L.; Bouville, A. [National Cancer Institute, National Institutes of Health, Bethesda, MD (United States); McKeever, S.W.S. [Oklahoma State University, Stillwater, OK (United States)

    2011-09-15

    Human teeth were studied for potential use as emergency Optically Stimulated Luminescence (OSL) dosimeters. By using multiple-teeth samples in combination with a custom-built sensitive OSL reader, {sup 60}Co-equivalent doses below 0.64 Gy were measured immediately after exposure with the lowest value being 27 mGy for the most sensitive sample. The variability of OSL sensitivity, from individual to individual using multiple-teeth samples, was determined to be 53%. X-ray and beta exposure were found to produce OSL curves with the same shape that differed from those due to ultraviolet (UV) exposure; as a result, correlation was observed between OSL signals after X-ray and beta exposure and was absent if compared to OSL signals after UV exposure. Fading of the OSL signal was 'typical' for most teeth with just a few of incisors showing atypical behavior. Typical fading dependences were described by a bi-exponential decay function with 'fast' (decay time around of 12 min) and 'slow' (decay time about 14 h) components. OSL detection limits, based on the techniques developed to-date, were found to be satisfactory from the point of view of medical triage requirements if conducted within 24 h of the exposure.

  9. Status of the DEBENE fast breeder reactor development, March 1979

    International Nuclear Information System (INIS)

    Daeunert, U.; Kessler, G.

    1979-01-01

    Status report of the Fast-breeder reactor development in Germany covers the following: description of the political situation in Federal republic of germany during 1978; international cooperation in the field of fast reactor technology development; operation description of the KNK-II fast core experimental power plant; status of construction of the SNR-300; results of the research and development programs concerned with fuel element, cladding, absorber rods and core structural materials development; sodium effects; neutron irradiation effects on SS properties; reactor physics related to experiments in fast critical assemblies; fast reactor safety issues; core disruption accidents; sodium boiling experiments, measuring methods developed; component tests

  10. Status of the DEBENE fast breeder reactor development, March 1979

    Energy Technology Data Exchange (ETDEWEB)

    Daeunert, U; Kessler, G

    1979-07-01

    Status report of the Fast-breeder reactor development in Germany covers the following: description of the political situation in Federal republic of germany during 1978; international cooperation in the field of fast reactor technology development; operation description of the KNK-II fast core experimental power plant; status of construction of the SNR-300; results of the research and development programs concerned with fuel element, cladding, absorber rods and core structural materials development; sodium effects; neutron irradiation effects on SS properties; reactor physics related to experiments in fast critical assemblies; fast reactor safety issues; core disruption accidents; sodium boiling experiments, measuring methods developed; component tests.

  11. The fast breeder reactor

    International Nuclear Information System (INIS)

    Collier, J.

    1990-01-01

    The arguments for and against the fast breeder reactor are debated. The case for the fast reactor is that the world energy demand will increase due to increasing population over the next forty years and that the damage to the global environment from burning fossil fuels which contribute to the greenhouse effect. Nuclear fission is the only large scale energy source which can achieve a cut in the use of carbon based fuels although energy conservation and renewable sources will also be important. Fast reactors produce more energy from uranium than other types of (thermal) reactors such as AGRs and PWRs. Fast reactors would be important from about 2020 onwards especially as by then many thermal reactors will need to be replaced. Fast reactors are also safer than normal reactors. The arguments against fast reactors are largely economic. The cost, especially the capital cost is very high. The viability of the technology is also questioned. (UK)

  12. The fast breeder reactor

    International Nuclear Information System (INIS)

    Davis, D.A.; Baker, M.A.W.; Hall, R.S.

    1990-01-01

    Following submission of written evidence, the Energy Committee members asked questions of three witnesses from the Central Electricity Generating Board and Nuclear Electric (which will be the government owned company running nuclear power stations after privatisation). Both questions and answers are reported verbatim. The points raised include where the responsibility for the future fast reactor programme should lie, with government only or with private enterprise or both and the viability of fast breeder reactors in the future. The case for the fast reactor was stated as essentially strategic not economic. This raised the issue of nuclear cost which has both a construction and a decommissioning element. There was considerable discussion as to the cost of building a European Fast reactor and the cost of the electricity it would generate compared with PWR type reactors. The likely demand for fast reactors will not arrive for 20-30 years and the need to build a fast reactor now is questioned. (UK)

  13. Fast reactors worldwide

    International Nuclear Information System (INIS)

    Hall, R.S.; Vignon, D.

    1985-01-01

    The paper concerns the evolution of fast reactors over the past 30 years, and their present status. Fast reactor development in different countries is described, and the present position, with emphasis on cost reduction and collaboration, is examined. The French development of the fast breeder type reactor is reviewed, and includes: the acquisition of technical skills, the search for competitive costs and the spx2 project, and more advanced designs. Future prospects are also discussed. (U.K.)

  14. Fast breeder reactors

    International Nuclear Information System (INIS)

    Heinzel, V.

    1975-01-01

    The author gives a survey of 'fast breeder reactors'. In detail the process of breeding, the reasons for the development of fast breeders, the possible breeder reactors, the design criteria, fuels, cladding, coolant, and safety aspects are reported on. Design data of some experimental reactors already in operation are summarized in stabular form. 300 MWe Prototype-Reactors SNR-300 and PFR are explained in detail and data of KWU helium-cooled fast breeder reactors are given. (HR) [de

  15. OSL and Tl response characterization of micro LiF:Mg, Ti dosimeters to be applied to VMAT quality assurance

    Energy Technology Data Exchange (ETDEWEB)

    Bravim, A.; Campos, L. L. [Instituto de Pesquisas Energeticas e Nucleares / CNEN, Av. Lineu Prestes 2242, Cidade Universitaria, 05508-000 Sao Paulo (Brazil); Sakuraba, R. K.; Da Cruz, J. C., E-mail: ambravim@hotmail.com [Sociedade Beneficente Israelita Brasileira - Hospital Albert Einstein, Av. Albert Einstein 627/701, Jardim Leonor, 05652-900 Sao Paulo (Brazil)

    2014-08-15

    VMAT Rapid Arc is a new method of treatment responsible for a change in the setting of radiotherapy, bringing benefits and allowing a lower toxicity in the treatment of patients. With this treatment is possible to minimize the radiation dose to the healthy tissues and escalate the dose to the target volume (tumor) (Hall, 1998; Mundt, 2005; Bortfeld, 2006). The quality assurance is essential to verify the operation of all components involved in the process of treatment planning and dose delivery. Several organizations recommended the verification of patient dose for quality improvement in radiotherapy and the recommended maximum values for the uncertainty in the dose range of ± 5% (ICRU, 1976, AAPM, 1983). This paper aims to evaluate the feasibility of applying LiF:Mg,Ti micro dosimeters as a new method of dosimetry to VMAT Rapid Arc. (Author)

  16. Fast wave current drive

    International Nuclear Information System (INIS)

    Goree, J.; Ono, M.; Colestock, P.; Horton, R.; McNeill, D.; Park, H.

    1985-07-01

    Fast wave current drive is demonstrated in the Princeton ACT-I toroidal device. The fast Alfven wave, in the range of high ion-cyclotron harmonics, produced 40 A of current from 1 kW of rf power coupled into the plasma by fast wave loop antenna. This wave excites a steady current by damping on the energetic tail of the electron distribution function in the same way as lower-hybrid current drive, except that fast wave current drive is appropriate for higher plasma densities

  17. Upgrading the Fast Calorimeter Simulation in ATLAS

    CERN Document Server

    Schaarschmidt, Jana; The ATLAS collaboration

    2017-01-01

    The tremendous need for simulated samples now and even more so in the future, encourage the development of fast simulation techniques. The Fast Calorimeter Simulation is a faster though less accurate alternative to the full calorimeter simulation with Geant4. It is based on parametrizing the longitudunal and lateral energy deposits of single particles in the ATLAS calorimeter. Principal component analysis and machine learning techniques are used to improve the performance and decrease the memory need compared to the current version of the ATLAS Fast Calorimeter Simulation. The parametrizations are expanded to cover very high energies and very forward detector regions, to increase the applicability of the tool. A prototype of this upgraded Fast Calorimeter Simulation has been developed and first validations with single particles show substantial improvements over the previous version.

  18. Decoherence recuperating fast environmental dynamics

    International Nuclear Information System (INIS)

    Cetinbas, Murat

    2010-01-01

    We examine the exact internal decoherence dynamics of a qubit in an isolated Josephson charge-qubit quantum computer in the presence of one- and two-body static internal imperfections. By help of open system dynamics quantifiers, i.e. purity, fidelity, covariance and Loschmidt echo, we distinguish between non-unitary and unitary components of internal decoherence dynamics and show that the non-unitary component consists of two processes: system-environment entanglement and incoherence. Our results indicate that the incoherence process is the major source of internal decoherence rather than system-environment entanglement. We find that strong one-body intra-environmental interactions, which generate fast environmental dynamics, result in a rapid suppression of decoherence induced by both system-environment entanglement and incoherence processes. We explain the mechanisms of suppression of decoherence for these two processes and discuss our results.

  19. Fast Physics Testbed for the FASTER Project

    Energy Technology Data Exchange (ETDEWEB)

    Lin, W.; Liu, Y.; Hogan, R.; Neggers, R.; Jensen, M.; Fridlind, A.; Lin, Y.; Wolf, A.

    2010-03-15

    This poster describes the Fast Physics Testbed for the new FAst-physics System Testbed and Research (FASTER) project. The overall objective is to provide a convenient and comprehensive platform for fast turn-around model evaluation against ARM observations and to facilitate development of parameterizations for cloud-related fast processes represented in global climate models. The testbed features three major components: a single column model (SCM) testbed, an NWP-Testbed, and high-resolution modeling (HRM). The web-based SCM-Testbed features multiple SCMs from major climate modeling centers and aims to maximize the potential of SCM approach to enhance and accelerate the evaluation and improvement of fast physics parameterizations through continuous evaluation of existing and evolving models against historical as well as new/improved ARM and other complementary measurements. The NWP-Testbed aims to capitalize on the large pool of operational numerical weather prediction products. Continuous evaluations of NWP forecasts against observations at ARM sites are carried out to systematically identify the biases and skills of physical parameterizations under all weather conditions. The highresolution modeling (HRM) activities aim to simulate the fast processes at high resolution to aid in the understanding of the fast processes and their parameterizations. A four-tier HRM framework is established to augment the SCM- and NWP-Testbeds towards eventual improvement of the parameterizations.

  20. FATRAS - the ATLAS Fast Track Simulation project

    NARCIS (Netherlands)

    Mechnich, J.

    2011-01-01

    The Monte Carlo simulation of the detector response is an integral component of any analysis performed with data from the LHC experiments. As these simulated data sets must be both large and precise, their production is a CPU-intensive task. ATLAS has developed full and fast detector simulation

  1. Fast Flux Test Facility (FFTF) maintenance provisions

    International Nuclear Information System (INIS)

    Marshall, J.L.

    1981-05-01

    The Fast Flux Test Facility (FFTF) was designed with maintainability as a primary parameter, and facilities and provisions were designed into the plant to accommodate the maintenance function. This paper describes the FFTF and its systems. Special maintenance equipment and facilities for performing maintenance on radioactive components are discussed. Maintenance provisions designed into the plant to enhance maintainability are also described

  2. Thermally assisted OSL application for equivalent dose estimation; comparison of multiple equivalent dose values as well as saturation levels determined by luminescence and ESR techniques for a sedimentary sample collected from a fault gouge

    Energy Technology Data Exchange (ETDEWEB)

    Şahiner, Eren, E-mail: sahiner@ankara.edu.tr; Meriç, Niyazi, E-mail: meric@ankara.edu.tr; Polymeris, George S., E-mail: gspolymeris@ankara.edu.tr

    2017-02-01

    Highlights: • Multiple equivalent dose estimations were carried out. • Additive ESR and regenerative luminescence were applied. • Preliminary SAR results employing TA-OSL signal were discussed. • Saturation levels of ESR and luminescence were investigated. • IRSL{sub 175} and SAR TA-OSL stand as very promising for large doses. - Abstract: Equivalent dose estimation (D{sub e}) constitutes the most important part of either trap-charge dating techniques or dosimetry applications. In the present work, multiple, independent equivalent dose estimation approaches were adopted, using both luminescence and ESR techniques; two different minerals were studied, namely quartz as well as feldspathic polymineral samples. The work is divided into three independent parts, depending on the type of signal employed. Firstly, different D{sub e} estimation approaches were carried out on both polymineral and contaminated quartz, using single aliquot regenerative dose protocols employing conventional OSL and IRSL signals, acquired at different temperatures. Secondly, ESR equivalent dose estimations using the additive dose procedure both at room temperature and at 90 K were discussed. Lastly, for the first time in the literature, a single aliquot regenerative protocol employing a thermally assisted OSL signal originating from Very Deep Traps was applied for natural minerals. Rejection criteria such as recycling and recovery ratios are also presented. The SAR protocol, whenever applied, provided with compatible D{sub e} estimations with great accuracy, independent on either the type of mineral or the stimulation temperature. Low temperature ESR signals resulting from Al and Ti centers indicate very large D{sub e} values due to bleaching in-ability, associated with large uncertainty values. Additionally, dose saturation of different approaches was investigated. For the signal arising from Very Deep Traps in quartz saturation is extended almost by one order of magnitude. It is

  3. Fast multichannel analyser

    Energy Technology Data Exchange (ETDEWEB)

    Berry, A; Przybylski, M M; Sumner, I [Science Research Council, Daresbury (UK). Daresbury Lab.

    1982-10-01

    A fast multichannel analyser (MCA) capable of sampling at a rate of 10/sup 7/ s/sup -1/ has been developed. The instrument is based on an 8 bit parallel encoding analogue to digital converter (ADC) reading into a fast histogramming random access memory (RAM) system, giving 256 channels of 64 k count capacity. The prototype unit is in CAMAC format.

  4. A fast multichannel analyser

    International Nuclear Information System (INIS)

    Berry, A.; Przybylski, M.M.; Sumner, I.

    1982-01-01

    A fast multichannel analyser (MCA) capable of sampling at a rate of 10 7 s -1 has been developed. The instrument is based on an 8 bit parallel encoding analogue to digital converter (ADC) reading into a fast histogramming random access memory (RAM) system, giving 256 channels of 64 k count capacity. The prototype unit is in CAMAC format. (orig.)

  5. Islamic Fasting and Diabetes

    Directory of Open Access Journals (Sweden)

    Fereidoun Azizi

    2013-07-01

    Full Text Available The aim of this article is to review health-related aspects of Ramadan fasting in normal individuals and diabetics. During fasting days of Ramadan, glucose homeostasis is maintained by meal taken bepore dawn and by liver glycogen stores. Changes in serum lipids are variable and defend on the quality and quantity of food consumption and changes in weight. Compliant, well controlled type 2 diabetics may observe Ramadan fasting; but fasting is not recommended for type 1, non complaint, poorly controlled and pregnant diabetics. Although Ramadan fasting is safe for all healthy individuals and well controlled diabetics, those with uncontrolled diabetics and diabetics with complications should consult physicians and follow scientific recommendations.

  6. Fast Spectrum Reactors

    CERN Document Server

    Todd, Donald; Tsvetkov, Pavel

    2012-01-01

    Fast Spectrum Reactors presents a detailed overview of world-wide technology contributing to the development of fast spectrum reactors. With a unique focus on the capabilities of fast spectrum reactors to address nuclear waste transmutation issues, in addition to the well-known capabilities of breeding new fuel, this volume describes how fast spectrum reactors contribute to the wide application of nuclear power systems to serve the global nuclear renaissance while minimizing nuclear proliferation concerns. Readers will find an introduction to the sustainable development of nuclear energy and the role of fast reactors, in addition to an economic analysis of nuclear reactors. A section devoted to neutronics offers the current trends in nuclear design, such as performance parameters and the optimization of advanced power systems. The latest findings on fuel management, partitioning and transmutation include the physics, efficiency and strategies of transmutation, homogeneous and heterogeneous recycling, in addit...

  7. Fast ejendom III

    DEFF Research Database (Denmark)

    Munk-Hansen, Carsten

    Bogen er det tredje bind af tre planlagte bind om fast ejendom: I Overdragelsen, II Bolighandlen og III Ejerbeføjelsen. Fremstillingens giver et grundigt overblik over centrale områder af en omfattende regulering af fast ejendom, med angivelse af litteratur, hvor læseren kan søge yderligere...... oplysning. En ejer af fast ejendom er på særdeles mange områder begrænset i sin råden sammenlignet med ejeren af et formuegode i almindelighed. Fremstillingen tager udgangspunkt i ejerens perspektiv (fremfor samfundets eller myndighedernes). Både den privatretlige og offentligretlige regulering behandles......, eksempelvis ejendomsdannelsen, servitutter, naboretten, hævd, zoneinddelingen, den fysiske planlægning, beskyttelse af natur, beskyttelse af kultur, forurening fra fast ejendom, erstatning for forurening, jordforurening, ekspropriation, byggeri og adgang til fast ejendom....

  8. Fast fission phenomena

    International Nuclear Information System (INIS)

    Gregoire, Christian.

    1982-03-01

    Experimental studies of fast fission phenomena are presented. The paper is divided into three parts. In the first part, problems associated with fast fission processes are examined in terms of interaction potentials and a dynamic model is presented in which highly elastic collisions, the formation of compound nuclei and fast fission appear naturally. In the second part, a description is given of the experimental methods employed, the observations made and the preliminary interpretation of measurements suggesting the occurence of fast fission processes. In the third part, our dynamic model is incorporated in a general theory of the dissipative processes studied. This theory enables fluctuations associated with collective variables to be calculated. It is applied to highly inelastic collisions, to fast fission and to the fission dynamics of compound nuclei (for which a schematic representation is given). It is with these calculations that the main results of the second part can be interpreted [fr

  9. A review of the U.K. fast reactor programme: March 1978

    International Nuclear Information System (INIS)

    Smith, R.D.

    1978-01-01

    The review of the UK fast reactor programme covers the description of Dounreay Fast Reactor shut down after seventeen years of successful operation; description of prototype fast reactor (PFR); core design parameters safety features and plant design for commercial demonstration fast reactor (CDFR). Engineering development is related to large sodium rigs, coolant circuit hydraulics and vibration, instrumentation and components. The subjects of interest are material development, sodium technology, fast reactor fuel, fuel cycle, reactor safety, reactor performance studies

  10. A review of the U.K. fast reactor programme: March 1978

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R D [United Kingdom Atomic Energy Authority, Risley (United Kingdom)

    1978-07-01

    The review of the UK fast reactor programme covers the description of Dounreay Fast Reactor shut down after seventeen years of successful operation; description of prototype fast reactor (PFR); core design parameters safety features and plant design for commercial demonstration fast reactor (CDFR). Engineering development is related to large sodium rigs, coolant circuit hydraulics and vibration, instrumentation and components. The subjects of interest are material development, sodium technology, fast reactor fuel, fuel cycle, reactor safety, reactor performance studies.

  11. Optically stimulated luminescence from quartz measured using the linear modulation technique

    International Nuclear Information System (INIS)

    Bulur, E.; Boetter-Jensen, L.; Murray, A.S.

    2000-01-01

    The optically stimulated luminescence (OSL) from heated natural quartz has been investigated using the linear modulation technique (LMT), in which the excitation light intensity is increased linearly during stimulation. In contrast to conventional stimulation, which usually produces a monotonically decreasing signal, linearly increasing the stimulation power gives peaks in the signal as a function of time. In cases where the OSL signal contains more than one component, the linear increase in power of the stimulation light may result in a curve containing overlapping peaks, where the most easily stimulated component occurs at a shorter time. This allows the separation of the overlapping OSL components, which are assumed to originate from different traps. The LM-OSL curve from quartz shows an initial peak followed by a broad one. Deconvolution using curve fitting has shown that the composite OSL curve from quartz can be approximated well by using a linear combination of first-order peaks. In addition to the three known components, i.e. fast, medium and slow components from continuous-wave-OSL studies, an additional slow component is also identified for the first time. The dose responses and thermal stabilities of the various components are also studied

  12. A review of the UK fast reactor programme

    International Nuclear Information System (INIS)

    Wheeler, R.C.; Bramman, J.I.

    1988-04-01

    The fast reactor programme in the United Kindom is reviewed under the following headings: Progress with PFR; Reprocessing: Commercial Design Studies; Structural Integrity; Engineering and Components; Materials; Sodium Chemistry; Core and Fuel; Safety; Plant Performance. (author)

  13. Overview of pool hydraulic design of Indian prototype fast breeder ...

    Indian Academy of Sciences (India)

    Flow sheet of prototype fast breeder reactor. ... over, the main vessel that houses radioactive primary sodium is free of any ..... with superficial velocity components in porous media. ..... The attenuation within thermal boundary layer was found.

  14. Liquid metal cooled experimental fast reactor simulator

    International Nuclear Information System (INIS)

    Guimaraes, Lamartine; Braz Filho, Francisco; Borges, Eduardo M.; Rosa, Mauricio A.P.; Rocamora, Francisco; Hirdes, Viviane R.

    1997-01-01

    This paper is a continuation of the work that has been done in the area of fast reactor component dynamic analysis, as part of the REARA project at the IEAv/CTA-Brazil. A couple of preceding papers, presented in other meetings, introduced major concept design components of the REARA reactor. The components are set together in order to represent a full model of the power plant. Full model transient results will be presented, together with several parameters to help us to better establish the REARA experimental plant concept. (author). 8 refs., 6 figs., 3 tabs

  15. Fast Breeder Reactor studies

    International Nuclear Information System (INIS)

    Till, C.E.; Chang, Y.I.; Kittel, J.H.; Fauske, H.K.; Lineberry, M.J.; Stevenson, M.G.; Amundson, P.I.; Dance, K.D.

    1980-07-01

    This report is a compilation of Fast Breeder Reactor (FBR) resource documents prepared to provide the technical basis for the US contribution to the International Nuclear Fuel Cycle Evaluation. The eight separate parts deal with the alternative fast breeder reactor fuel cycles in terms of energy demand, resource base, technical potential and current status, safety, proliferation resistance, deployment, and nuclear safeguards. An Annex compares the cost of decommissioning light-water and fast breeder reactors. Separate abstracts are included for each of the parts

  16. Fast track-hoftealloplastik

    DEFF Research Database (Denmark)

    Hansen, Torben Bæk; Gromov, Kirill; Kristensen, Billy B

    2017-01-01

    Fast-track surgery implies a coordinated perioperative approach aimed at reducing surgical stress and facilitating post-operative recovery. The fast-track programme has reduced post-operative length of stay and has led to shorter convalescence with more rapid functional recovery and decreased...... morbidity and mortality in total hip arthroplasty. It should now be a standard total hip arthroplasty patient pathway, but fine tuning of the multiple factors in the fast-track pathway is still needed in patients with special needs or high comorbidity burden....

  17. Fast Breeder Reactor studies

    Energy Technology Data Exchange (ETDEWEB)

    Till, C.E.; Chang, Y.I.; Kittel, J.H.; Fauske, H.K.; Lineberry, M.J.; Stevenson, M.G.; Amundson, P.I.; Dance, K.D.

    1980-07-01

    This report is a compilation of Fast Breeder Reactor (FBR) resource documents prepared to provide the technical basis for the US contribution to the International Nuclear Fuel Cycle Evaluation. The eight separate parts deal with the alternative fast breeder reactor fuel cycles in terms of energy demand, resource base, technical potential and current status, safety, proliferation resistance, deployment, and nuclear safeguards. An Annex compares the cost of decommissioning light-water and fast breeder reactors. Separate abstracts are included for each of the parts.

  18. Temporal limits to the archaeological record in arid western NSW, Australia : lessons from OSL and radiocarbon dating of hearths and sediments

    International Nuclear Information System (INIS)

    Fanning, P.; Holdaway, S.

    2001-01-01

    The Western NSW Archaeology Program (WNSWAP) has been investigating surface scatters of Aboriginal stone artefacts and associated heat-retainer hearths in arid northwestern NSW, Australia, since 1995. The research combines new methods for documenting and analysing stone artefact scatters with an understanding of geomorphic landscape dynamics to seek insights into spatial and temporal patterns of Aboriginal occupation of the arid margin of Australia during the Late Holocene. The temporal dimension is dealt with in two ways: by radiocarbon determinations on charcoal from the remains of heat-retainer hearths associated with the artefact scatters, and by using optically simulated luminescence (OSL) and radiocarbon determinations from valley fill sediments to develop a chronology of landscape evolution of the valleys in which the artefacts and hearths are found. The heat-retainer hearths produced a record of just less than 2000 years of activity within the valley of Stud Creek, a 30 square km catchment in Sturt National Park. However, the record is discontinuous, with a gap in heat-retainer hearth construction of 200-400 years occurring between about 800 and 1100 y BP. Examination of patterns of erosion and deposition at the places where the hearths were found, and Bayesian statistical analysis of the radiocarbon determinations, demonstrates that this gap is real and not an artefact of the survey protocol. A discontinuous record is also evident when the sediments that comprise the valley fill upon which the hearths and stone artefact scatters are currently lying are examined. Five major sedimentary units can be identified, providing a record of depositional episodes ranging from modern or post-European back to the Late Pleistocene (about 70,000 years). But, in contrast to the record from the remains of the heat-retainer hearths, erosion is the major determinant of the temporal pattern of landscape change that can be reconstructed from this record. Gaps of up to 10

  19. SU-F-P-50: Performance Evaluation of Optically Stimulated Luminescence (OSL) NanoDots in Therapy and Imaging In-Vivo Dose Measurement During Patient Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S; Sarkar, B; Kaur, H; Rathinamuthu, S; Giri, U; Jassal, K; Ganesh, T; Munshi, A; Mohanti, B; Krishnankutty, S; Sathiya, J [Fortis Memorial Research Institute, Gurgaon, Haryana (India)

    2016-06-15

    Purpose: This study was designed to evaluate the performance of optically stimulated Luminescence (OSL) nanoDots as in-vivo dosimeter. For the measurements of surface doses as well as scattered plus leakage doses, nanoDots were used during the setup verification as well as during the treatment delivery. Methods: For a total seven patients undergoing radiotherapy by volumetric modulated arc therapy, surface doses from image guidance and scattered plus leakage doses from treatment delivery were measured. Two sets of calibration curves were generated – one for therapy and another for imaging. Two different nanoDots were used for imaging and therapy doses. Imaging nanoDots were placed at the isocenter only at the time of CBCT and therapy nanoDots were placed at 25 cm away from the isocenter (either in cranial or in caudal direction) only at the time of treatment delivery. During the entire course, nanoDots were placed at the same measurement points. NanoDots were read after 15 minutes of their exposure. For the next fraction, nanoDots were corrected for the residual doses from the previous fractions. Results: Measured surface doses during imaging were 0.14±0.32 cGy, 0.11±0.04 cGy, 0.12±0.53 cGy, 0.04±0.02 cGy, 0.13±0.23 cGy, 0.11±0.43 cGy, 0.10±0.04 cGy with overall mean dose of 0.08±0.1 cGy. Measured doses during treatment delivery, indicative of scattered and leakage dose, were 0.84±0.43 cGy, 1.3±0.4 cGy, 1.4±0.4 cGy, 0.18±0.48 cGy, 0.78±0.29 cGy, 0.27±0.08 cGy, 0.78±0.07 cGy with overall mean dose of 0.61±1.3 cGy. Conclusion: This dosimeter can be used as supplementary unit to verify the doses. No change in the prescription is recommended based on nanoDots measurement. This study is on-going therefore we are presenting only mere number of patients. A large volume data will be presented after completion of the study with proper statistical analysis.

  20. The new ATLAS Fast Calorimeter Simulation

    CERN Document Server

    Hasib, Ahmed; The ATLAS collaboration

    2017-01-01

    Producing the very large samples of simulated events required by many physics and performance studies with the ATLAS detector using the full GEANT4 detector simulation is highly CPU intensive. Fast simulation tools are a useful way of reducing CPU requirements when detailed detector simulations are not needed. During the LHC Run-1, a fast calorimeter simulation (FastCaloSim) was successfully used in ATLAS. FastCaloSim provides a simulation of the particle energy response at the calorimeter read-out cell level, taking into account the detailed particle shower shapes and the correlations between the energy depositions in the various calorimeter layers. It is interfaced to the standard ATLAS digitization and reconstruction software, and it can be tuned to data more easily than GEANT4. Now an improved version of FastCaloSim is in development, incorporating the experience with the version used during Run-1. The new FastCaloSim makes use of statistical techniques such as principal component analysis, and a neural n...

  1. The dismantling of fast reactors: sodium processing

    International Nuclear Information System (INIS)

    Rodriguez, G.; Berte, M.; Serpante, J.P.

    1999-01-01

    Fast reactors require a coolant that does not slow down neutrons so water can not be used. Metallic sodium has been chosen because of its outstanding neutronic and thermal properties but sodium reacts easily with air and water and this implies that sodium-smeary components can not be considered as usual nuclear wastes. A stage of sodium neutralizing is necessary in the processing of wastes from fast reactors. Metallic sodium is turned into a chemically stable compound: soda, carbonates or sodium salts. This article presents several methods used by Framatome in an industrial way when dismantling sodium-cooled reactors. (A.C.)

  2. FastStats: Measles

    Science.gov (United States)

    ... Women’s Health State and Territorial Data Reproductive Health Contraceptive Use Infertility Reproductive Health Notice Regarding FastStats Mobile ... measles, mumps, rubella: 91.9% (2015) Percent of adolescents aged 13-17 years vaccinated against measles, mumps, ...

  3. Fast neutrons dosimetry

    International Nuclear Information System (INIS)

    Rzyski, B.M.

    1977-01-01

    A proton recoil technique has been developed for inducing thermoluminescence with incident fast neutrons. CaF 2 was used as the TL phosphor, and cane sugar and polyethylene were used as proton radiators. The phosphor and the hydrogeneous material powders were well mixed, encapsulated in glass tubes and exposed to Am-Be sources, resulting in recoils from incident fast neutrons of energy between 0,25 and 11,25 MeV. The intrinsic response of pure CaF 2 to fast neutrons without a hydrogeneous radiator was checked by using LiF (TLD-700). Glow curves were recorded from room temperature up to 350 0 C after different doses of neutrons and gamma rays of 60 Co. First collision dose due to fast neutrons in tissue like materials such as cane sugar and polyethylene was also calculated [pt

  4. Dounreay fast reactor

    International Nuclear Information System (INIS)

    Maclennan, R.; Eggar, T.; Skeet, T.

    1992-01-01

    The short debate which followed a private notice question asking for a statement on Government policy on the future of the European fast breeder nuclear research programme is reported verbatim. In response to the question, the Minister for Energy said that the Government had decided in 1988 that the Dounreay prototype fast reactor would close in 1994. That decision had been confirmed. Funding of fast breeder research and development beyond 1993 is not a priority as commercialization is not expected until well into the next century. Dounreay will be supported financially until 1994 and then for its subsequent decommissioning and reprocessing of spent fuel. The debate raised issues such as Britain losing its lead in fast breeder research, loss of jobs and the Government's nuclear policy in general. However, the Government's position was that the research had reached a stage where it could be left and returned to in the future. (UK)

  5. CMS Fast Facts

    Data.gov (United States)

    U.S. Department of Health & Human Services — CMS has developed a new quick reference statistical summary on annual CMS program and financial data. CMS Fast Facts includes summary information on total program...

  6. Brug af faste vendinger

    DEFF Research Database (Denmark)

    Bergenholtz, Henning; Bjærge, Esben

    Ordbogen indelholder tekstproduktionsangivelser til ca. 17.000 idiomer, ordsprog, bevingede ord og andre faste vendinger. Det drejer sig bl.a. om angivelser til betydningen, grammatik, kollokationer, eksempler, synonymer og antonymer....

  7. Fasting and Urinary Stones

    Directory of Open Access Journals (Sweden)

    Ali Shamsa

    2013-11-01

    Full Text Available Introduction: Fasting is considered as one of the most important practices of Islam, and according to Prophet Mohammad, fasting is obligatory upon Muslims. The aim of this study is to evaluate the effects of fasting on urinary stones. Materials and Methods: Very few studies have been carried out on urinary stones and the effect of Ramadan fasting. The sources of the present study are Medline and articles presented by local and Muslim researchers. Meanwhile, since we are acquainted with three well-known researchers in the field of urology, we contacted them via email and asked for their professional opinions. Results: The results of studies about the relationship of urinary stones and their incidence in Ramadan are not alike, and are even sometimes contradictory. Some believe that increased incidence of urinary stones in Ramadan is related not to fasting, but to the rise of weather temperature in hot months, and an increase in humidity. Conclusion: Numerous biological and behavioral changes occur in people who fast in Ramadan and some researchers believe that urinary stone increases during this month.

  8. Formation of fast exotic atoms by radiative Coulomb capture

    International Nuclear Information System (INIS)

    Chatterjee, L.; Das, G.; Chakravorty, A.; Goswami, R.; Mondal, S.K.

    1993-01-01

    Interesting surprises in some exotic atom kinetics have been reported recently. These involve muonic atom transfer cross sections, nuclear pion capture and the q 1s effect in μCF. These can be explained if the exotic atom population contains a contributing fast component. Such fast atoms can be formed by radiative continuum to bound transitions of fast (keV) muons or pions. Cross sections for formation of such fast pionic and muonic atoms and their velocity distributions are reported. The possibility of these processes competing with the thermalisation channels and contributing effectively to the exotic atom population discussed. (orig.)

  9. Decommissioning of fast reactors after sodium draining

    International Nuclear Information System (INIS)

    2009-11-01

    Acknowledging the importance of passing on knowledge and experience, as well mentoring the next generation of scientists and engineers, and in response to expressed needs by Member States, the IAEA has undertaken concrete steps towards the implementation of a fast reactor data retrieval and knowledge preservation initiative. Decommissioning of fast reactors and other sodium bearing facilities is a domain in which considerable experience has been accumulated. Within the framework and drawing on the wide expertise of the Technical Working Group on Fast Reactors (TWG-FR), the IAEA has initiated activities aiming at preserving the feedback (lessons learned) from this experience and condensing those to technical recommendations on fast reactor design features that would ease their decommissioning. Following a recommendation by the TWG-FR, the IAEA had convened a topical Technical Meeting (TM) on 'Operational and Decommissioning Experience with Fast Reactors', hosted by CEA, Centre d'Etudes de Cadarache, France, from 11 to 15 March 2002 (IAEA-TECDOC- 1405). The participants in that TM exchanged detailed technical information on fast reactor operation and decommissioning experience with various sodium cooled fast reactors, and, in particular, reviewed the status of the various decommissioning programmes. The TM concluded that the decommissioning of fast reactors to reach safe enclosure presented no major difficulties, and that this had been accomplished mainly through judicious adaptation of processes and procedures implemented during the reactor operation phase, and the development of safe sodium waste treatment processes. However, the TM also concluded that, on the path to achieving total dismantling, challenges remain with regard to the decommissioning of components after sodium draining, and suggested that a follow-on TM be convened, that would provide a forum for in-depth scientific and technical exchange on this topic. This publication constitutes the Proceedings of

  10. New fast switches for the Tore Supra ohmic heating circuit

    International Nuclear Information System (INIS)

    Zunino, K.; Bruneth, J.; Cara, P.; Louart, A.; Santagiustina, A.; Emelyanova, I.; Filippov, F.; Mikailov, N.

    2003-01-01

    The Tore-Supra ohmic heating circuit is equipped with four fast make switches and one fast opening switch. After many years of operation, it became necessary to substitute this equipment by modern components with similar ratings. An extensive research has been undertaken to find fast switches able to withstand more than 2500 operations per year without maintenance, at a make current of 54 kA, a voltage of 12 kV and with a closing time of less than 15 ms. At the end of the investigation, it was decided to replace the old components by fast mechanical switches proposed by the Efremov Institute and based on a prototype developed for ITER. This paper presents the technical requirements and the characteristics of the switches and describes the operational experience gained with these components during operating campaigns of 2002 and 2003. (authors)

  11. Holography for fast reactor inspection

    International Nuclear Information System (INIS)

    Tozer, B.A.

    1980-01-01

    Holography, an optical process whereby an image of the original subject can be reconstructed in three dimensions, is being developed for use as an optical inspection tool. With a potential information storage density of 10 16 bits/m 2 , the ability to reconstruct in 3 dimensions, a depth of field of up to 8 metres, extremely wide angle of view, and potentially diffraction limited resolution, holography should be invaluable for the optical recording of fast reactors during construction, and the inspection of optically accessible regions during operation, or maintenance down-times. The photographic emulsions used for high resolution holography are fine-grained and fog only very slowly when subjected to γ-radiation, so that inspection of highly radio-active regions and components can be effected satisfactorily. Some of the practical limitations affecting holography are described and ways of overcoming them discussed. Some preliminary results are presented. (author)

  12. Fast breeder reactors

    International Nuclear Information System (INIS)

    Waltar, A.E.; Reynolds, A.B.

    1981-01-01

    This book describes the major design features of fast breeder reactors and the methods used for their design and analysis. The foremost objective of this book is to fulfill the need for a textbook on Fast Breeder Reactor (FBR) technology at the graduate level or the advanced undergraduate level. It is assumed that the reader has an introductory understanding of reactor theory, heat transfer, and fluid mechanics. The book is expected to be used most widely for a one-semester general course on fast breeder reactors, with the extent of material covered to vary according to the interest of the instructor. The book could also be used effectively for a two-quarter or a two-semester course. In addition, the book could serve as a text for a course on fast reactor safety since many topics other than those appearing in the safety chapters relate to FBR safety. Methodology in fast reactor design and analysis, together with physical descriptions of systems, is emphasized in this text more than numerical results. Analytical and design results continue to change with the ongoing evolution of FBR design whereas many design methods have remained fundamentally unchanged for a considerable time

  13. The fast breeder reactor

    International Nuclear Information System (INIS)

    Patterson, W.

    1990-01-01

    The author criticises the United Kingdom Atomic Energy Authority's fast breeder reactor programme in his evidence to the House of Commons Select Committee on Energy in January 1990. He argues for power generation by renewable means and greater efficiency in the use rather than in the generation of electricity. He refutes the arguments for nuclear power on the basis of reduced global warming as he claims support technology produces significant amounts of carbon dioxide in any case. Serious doubts are raised about the costs of a fast breeder reactor programme compared to, say, generation by pressurised water reactors. The idea of a uranium scarcity in several decades is also refuted. The reliability of fast breeder reactor technology is called into question. He argues against reprocessing plutonium for economic, health and safety reasons. (UK)

  14. The fast code

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, L.N.; Wilson, R.E. [Oregon State Univ., Dept. of Mechanical Engineering, Corvallis, OR (United States)

    1996-09-01

    The FAST Code which is capable of determining structural loads on a flexible, teetering, horizontal axis wind turbine is described and comparisons of calculated loads with test data are given at two wind speeds for the ESI-80. The FAST Code models a two-bladed HAWT with degrees of freedom for blade bending, teeter, drive train flexibility, yaw, and windwise and crosswind tower motion. The code allows blade dimensions, stiffnesses, and weights to differ and models tower shadow, wind shear, and turbulence. Additionally, dynamic stall is included as are delta-3 and an underslung rotor. Load comparisons are made with ESI-80 test data in the form of power spectral density, rainflow counting, occurrence histograms, and azimuth averaged bin plots. It is concluded that agreement between the FAST Code and test results is good. (au)

  15. Fast beam radiofrequency spectroscopy

    International Nuclear Information System (INIS)

    Pipkin, F.M.

    1983-01-01

    The combination of a fast atom or ion beam derived from a small accelerator with radiofrequency spectroscopy methods provides a powerful method for measuring the fine structure of atomic and molecular systems. The fast beam makes possible measurements in which two separated oscillatory fields are used to obtain resonance lines whose widths are less than the natural line width due to the lifetimes of the states. The separated oscillatory field lines have, in addition, a number of features which make possible measurements with greater precision and less sensitivity to systematic errors. The fast beam also makes accessible multiple photon radiofrequency transitions whose line width is intrinsically narrower than that of the single photon transitions and which offer great potential for high precision measurements. This report focuses on the techniques and their promise. Recent measurements of the fine structure of H and He + are used as illustrations

  16. The fast breeder reactor

    International Nuclear Information System (INIS)

    Keck, O.

    1984-01-01

    Nowadays the fast-breeder reactor is a negative symbol of advanced technology which is getting out of control and, due to its complexity, is incomprehensible for politicians and therefore by-passes the established order. The author lists the most important decisions over state aid to the fast-breeder-reactors up until the mid-seventies and uses documents from the appropriate advisory bodies as reference. He was also aided by interviews with those directly involved with the project. The empirical facts forces us to discard our traditional view of the relationship between state and industry with regard to advanced technology. The author explains that it is impossible to find any economic value in the fast-breeder reactor. The insight gained through this project allows him to draw conclusions which apply to all aspects of state aid to advanced technology. (orig.) [de

  17. Adopting preoperative fasting guidelines.

    Science.gov (United States)

    Anderson, Megan; Comrie, Rhonda

    2009-07-01

    In 1999, the American Society of Anesthesiologists adopted preoperative fasting guidelines to enhance the quality and efficiency of patient care. Guidelines suggest that healthy, non-pregnant patients should fast six hours from solids and two hours from liquids. Although these guidelines are in place, studies suggest that providers are still using the blanket statement "NPO after midnight" without regard to patient characteristics, the procedure, or the time of the procedure. Using theory to help change provider's beliefs may help make change more successful. Rogers' Theory of Diffusion of Innovations can assist in changing long-time practice by laying the groundwork for an analysis of the benefits and disadvantages of proposed changes, such as changes to fasting orders, while helping initiate local protocols instead of additional national guidelines.

  18. Prototype fast breeder reactor main options

    International Nuclear Information System (INIS)

    Bhoje, S.B.; Chellapandi, P.

    1996-01-01

    Fast reactor programme gets importance in the Indian energy market because of continuous growing demand of electricity and resources limited to only coal and FBR. India started its fast reactor programme with the construction of 40 MWt Fast Breeder Test Reactor (FBTR). The reactor attained its first criticality in October 1985. The reactor power will be raised to 40 MWt in near future. As a logical follow-up of FBTR, it was decided to build a prototype fast breeder reactor, PFBR. Considering significant effects of capital cost and construction period on economy, systematic efforts are made to reduce the same. The number of primary and secondary sodium loops and components have been reduced. Sodium coolant, pool type concept, oxide fuel, 20% CW D9, SS 316 LN and modified 9Cr-1Mo steel (T91) materials have been selected for PFBR. Based on the operating experience, the integrity of the high temperature components including fuel and cost optimization aspects, the plant temperatures are recommended. Steam temperature of 763 K at 16.6 MPa and a single TG of 500 MWe gross output have been decided. PFBR will be located at Kalpakkam site on the coast of Bay of Bengal. The plant life is designed for 30 y and 75% load factor. In this paper the justifications for the main options chosen are given in brief. (author). 2 figs, 2 tabs

  19. Creep fatigue design of FBR components

    International Nuclear Information System (INIS)

    Bhoje, S.B.; Chellapandi, P.

    1997-01-01

    This paper deals with the characteristic features of Fast Breeder Reactor (FBR) with reference to creep fatigue, current creep fatigue design approach in compliance with RCCMR (1987) design code, material data, effects of weldments and neutron irradiation, material constitutive models employed, structural analysis and further R and D required for achieving maturity in creep fatigue design of FBR components. For the analysis reported in this paper, material constitutive models developed based on ORNIb (Oak Ridge National Laboratory) and Chaboche viscoplastic theories are employed to demonstrate the potential of FBR components for higher plant temperatures and/or longer life. The results are presented for the studies carried out towards life prediction of Prototype Fast Breeder Reactor (PFBR) components. (author). 24 refs, 8 figs, 5 tabs

  20. Proton Fast Ignition

    International Nuclear Information System (INIS)

    Key, M H; Freeman, R R; Hatchett, S P; MacKinnon, A J; Patel, P K; Snavely, R A; Stephens, R B

    2006-04-01

    Fast ignition (FI) by a laser generated ballistically focused proton beam is a more recently proposed alternative to the original concept of FI by a laser generated beam of relativistic electrons. It has potential advantages in less complex energy transport into dense plasma. Recent successful target heating experiments motivate further investigation of the feasibility of proton fast ignition. The concept, the physics and characteristics of the proton beams, the recent experimental work on focusing of the beams and heating of solid targets and the overall prospects for proton FI are discussed

  1. Fast breeder project (PSB)

    International Nuclear Information System (INIS)

    1976-07-01

    Activities performed during the 1st quarter of 1976 at or on behalf of the Gesellschaft fuer Kernforschung mbH, Karlsruhe, within the framework of the Fast Breeder Project are given a survey. The following project subdivisions are dealt with: Fuel rod development; materials testing and developments; corrosion studies and coolant analyses; physical experiments; reactor theory; safety of fast breeders; instrumentation and signal processing for core monitoring; effects on the environment; sodium technology tests; thermodynamic and fluid flow tests in gas. (HR) [de

  2. Magnetically Assisted Fast Ignition

    OpenAIRE

    Wang, W.-M.; Gibbon, P.; Sheng, Z.-M.; Li, Y.-T.

    2015-01-01

    Fast ignition (FI) is investigated via integrated particle-in-cell simulation including both generation andtransport of fast electrons, where petawatt ignition lasers of 2 ps and compressed targets of a peak density of300 g cm−3 and areal density of 0.49 g cm−2 at the core are taken. When a 20 MG static magnetic field isimposed across a conventional cone-free target, the energy coupling from the laser to the core is enhancedby sevenfold and reaches 14%. This value even exceeds that obtained u...

  3. Fast neutron dosimetry

    International Nuclear Information System (INIS)

    DeLuca, P.M. Jr.; Pearson, D.W.

    1993-01-01

    Research concentrated on three major areas during the last twelve months: (1) investigations of energy fluence and absorbed dose measurements using crystalline and hot pressed TLD materials exposes to ultrasoft beams of photons, (2) fast neutron kerma factor measurements for several important elements as well as NE-213 scintillation material response function determinations at the intense ''white'' source available at the WNR facility at LAMPF, and (3) kerma factor ratio determinations for carbon and oxygen to A-150 tissue equivalent plastic at the clinical fast neutron radiation facility at Harper Hospital, Detroit, MI. Progress summary reports of these efforts are given in this report

  4. Moms og fast ejendom

    DEFF Research Database (Denmark)

    Edlund, Hans Henrik

    1999-01-01

    I artiklen gives et overblik over, hvorledes fast ejendom behandles momsmæssigt. Derfor findes en kort skitsering af reglerne for moms på byggearbejder, afgrænsningen mellem momspligtig og momsfri udlejning, muligheden for frivillig registrering af udlejning samt opgørelse af reguleringsforpligte......I artiklen gives et overblik over, hvorledes fast ejendom behandles momsmæssigt. Derfor findes en kort skitsering af reglerne for moms på byggearbejder, afgrænsningen mellem momspligtig og momsfri udlejning, muligheden for frivillig registrering af udlejning samt opgørelse af...

  5. Fast ejendom II

    DEFF Research Database (Denmark)

    Munk-Hansen, Carsten

    Fremstillingen påviser, at lov om forbrugerbeskyttelse ved erhvervelse af fast ejendom mv. lider af en række svagheder og at ankenævnspraksis bevæger sig væk fra retspraksis på en række områder.......Fremstillingen påviser, at lov om forbrugerbeskyttelse ved erhvervelse af fast ejendom mv. lider af en række svagheder og at ankenævnspraksis bevæger sig væk fra retspraksis på en række områder....

  6. [Preoperative fasting. An update].

    Science.gov (United States)

    Spies, C D; Breuer, J P; Gust, R; Wichmann, M; Adolph, M; Senkal, M; Kampa, U; Weissauer, W; Schleppers, A; Soreide, E; Martin, E; Kaisers, U; Falke, K J; Haas, N; Kox, W J

    2003-11-01

    In Germany the predominant standard of preoperative care for elective surgery is fasting after midnight, with the aim of reducing the risk of pulmonary aspiration. However, for the past several years the scientific evidence supporting such a practice has been challenged. Experimental and clinical studies prove a reliable gastric emptying within 2 h suggesting that, particularly for limited intake of clear fluids up to 2 h preoperatively, there would be no increased risk for the patient. In addition, the general incidence of pulmonary aspiration during general anaesthesia (before induction, during surgery and during recovery) is extremely low, has a good prognosis and is more a consequence of insufficient airway protection and/or inadequate anaesthetic depth rather than due to the patient's fasting state. Therefore, primarily to decrease perioperative discomfort for patients, several national anaesthesia societies have changed their guidelines for preoperative fasting. They recommend a more liberal policy regarding per os intake of both liquid and solid food, with consideration of certain conditions and contraindications. The following article reviews the literature and gives an overview of the scientific background on which the national guidelines are based. The intention of this review is to propose recommendations for preoperative fasting regarding clear fluids for Germany as well.

  7. Integral Fast Reactor concept

    International Nuclear Information System (INIS)

    Till, C.E.; Chang, Y.I.

    1986-01-01

    The Integral Fast Reactor (IFR) is an innovative LMR concept, being developed at Argonne National Laboratory, that fully exploits the inherent properties of liquid metal cooling and metallic fuel to achieve breakthroughs in economics and inherent safety. This paper describes key features and potential advantages of the IFR concept, technology development status, fuel cycle economics potential, and future development path

  8. FastStats: Immunization

    Science.gov (United States)

    ... Women’s Health State and Territorial Data Reproductive Health Contraceptive Use Infertility Reproductive Health Notice Regarding FastStats Mobile ... 69 [PDF – 9.8 MB] Vaccination coverage among adolescents 13-17 years of age Health, United States, ...

  9. Integral Fast Reactor concept

    Energy Technology Data Exchange (ETDEWEB)

    Till, C.E.; Chang, Y.I.

    1986-01-01

    The Integral Fast Reactor (IFR) is an innovative LMR concept, being developed at Argonne National Laboratory, that fully exploits the inherent properties of liquid metal cooling and metallic fuel to achieve breakthroughs in economics and inherent safety. This paper describes key features and potential advantages of the IFR concept, technology development status, fuel cycle economics potential, and future development path.

  10. Parallel Fast Legendre Transform

    NARCIS (Netherlands)

    Alves de Inda, M.; Bisseling, R.H.; Maslen, D.K.

    1998-01-01

    We discuss a parallel implementation of a fast algorithm for the discrete polynomial Legendre transform We give an introduction to the DriscollHealy algorithm using polynomial arithmetic and present experimental results on the eciency and accuracy of our implementation The algorithms were

  11. The Integral Fast Reactor

    International Nuclear Information System (INIS)

    Till, C.E.; Chang, Y.I.; Lineberry, M.J.

    1990-01-01

    Argonne National Laboratory, since 1984, has been developing the Integral Fast Reactor (IFR). This paper will describe the way in which this new reactor concept came about; the technical, public acceptance, and environmental issues that are addressed by the IFR; the technical progress that has been made; and our expectations for this program in the near term. 5 refs., 3 figs

  12. Viden om faste vendinger

    DEFF Research Database (Denmark)

    Bergenholtz, Henning; Bjærge, Esben

    2012-01-01

    Ordbogen indeholder ca. 17.000 idiomer, ordsprog, bevingede ord og andre faste vendinger, som der oplyses mest muligt om. Hertil hører oplysninger om betydningen, grammatik, kollokationer, synonymer, stil, ordforbindelsestype, etymologiske angivelser og andre baggrundsoplysninger, links til...

  13. Integral Fast Reactor Program

    International Nuclear Information System (INIS)

    Chang, Y.I.; Walters, L.C.; Laidler, J.J.; Pedersen, D.R.; Wade, D.C.; Lineberry, M.J.

    1993-06-01

    This report summarizes highlights of the technical progress made in the Integral Fast Reactor (IFR) Program in FY 1992. Technical accomplishments are presented in the following areas of the IFR technology development activities: (1) metal fuel performance, (2) pyroprocess development, (3) safety experiments and analyses, (4) core design development, (5) fuel cycle demonstration, and (6) LMR technology R ampersand D

  14. FAST goes underground

    International Nuclear Information System (INIS)

    Fridlund, P.S.

    1985-01-01

    The FAST-M Cost Estimating Model is a parametric model designed to determine the costs associated with mining and subterranean operations. It is part of the FAST (Freiman Analysis of Systems Techniques) series of parametric models developed by Freiman Parametric Systems, Inc. The rising cost of fossil fuels has created a need for a method which could be used to determine and control costs in mining and subterranean operations. FAST-M fills this need and also provides scheduling information. The model works equally well for a variety of situations including underground vaults for hazardous waste storage, highway tunnels, and mass transit tunnels. In addition, costs for above ground structures and equipment can be calculated. The input for the model may be on a macro or a micro level. This allows the model to be used at various stages in a project. On the macro level, only general conditions and specifications need to be known. On the micro level, the smallest details may be included. As with other FAST models, reference cases are used to more accurately predict costs and scheduling. This paper will address how the model can be used for a variety of subterranean purposes

  15. Fast Air Temperature Sensors

    DEFF Research Database (Denmark)

    Hendricks, Elbert

    1998-01-01

    The note documents briefly work done on a newly developed sensor for making fast temperature measurements on the air flow in the intake ports of an SI engine and in the EGR input line. The work reviewed has been carried out in close cooperation with Civ. Ing. Michael Føns, the author (IAU...

  16. Project fast breeder (PSB)

    International Nuclear Information System (INIS)

    1978-01-01

    The annual report of the fast breeder project (PSB) contains contributions of the participating institutes on the four subjects: 1) Development of oxidic fuel rods and materials for the SNR line, 2) Physics and safety investigations for the SNR line, 3) Carbidic fuel elements, and 4) Back-up solution with gaseous coolant. (HK) [de

  17. Fast ejendom, I

    DEFF Research Database (Denmark)

    Munk-Hansen, Carsten

    , værdiforringende forhold, der ligger uden for ejendommen og andre særlige tilfælde. Bogen uddyber andre emner omtalt i 1. udgave, eksempelvis erhvervelsesbetingelser, købsoptioner, ansvarsfraskrivelse, licitationssalg mv. Bogen er det første af tre planlagte bind om fast ejendom: I Overdragelsen, II Bolighandlen...

  18. Handel med fast ejendom

    DEFF Research Database (Denmark)

    Edlund, Hans Henrik

    Bogen tilstræber at give et overblik over nogle af de vigtigste generelle problemområder på markedet for ejendomshandel, der jo bliver mere og mere kompliceret. Værket er opdelt i følgende hovedafsnit: Ejendomsbegrebet. Indgåelse af aftale om salg af fast ejendom. Begrænsninger i adgangen til...

  19. Fast Harmonic Chirp Summation

    DEFF Research Database (Denmark)

    Nielsen, Jesper Kjær; Jensen, Tobias Lindstrøm; Jensen, Jesper Rindom

    2017-01-01

    -robust to noise, or very computationally inten- sive. In this paper, we propose a fast algorithm for the harmonic chirp summation method which has been demonstrated in the liter- ature to be accurate and robust to noise. The proposed algorithm is orders of magnitudes faster than previous algorithms which is also...

  20. Nanolensed Fast Radio Bursts

    Science.gov (United States)

    Eichler, David

    2017-12-01

    It is suggested that fast radio bursts can probe gravitational lensing by clumpy dark matter objects that range in mass from 10-3 M ⊙-102 M ⊙. They may provide a more sensitive probe than observations of lensings of objects in the Magellanic Clouds, and could find or rule out clumpy dark matter with an extended mass spectrum.

  1. ATLAS fast physics monitoring

    Indian Academy of Sciences (India)

    The ATLAS Collaboration has set up a framework to automatically process the rapidly growing dataset and produce performance and physics plots for the most interesting analyses. The system is designed to give fast feedback. The histograms are produced within hours of data reconstruction (2–3 days after data taking).

  2. Calorie count - fast food

    Science.gov (United States)

    ... GO About MedlinePlus Site Map FAQs Customer Support Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Calorie count - fast food URL of this page: //medlineplus.gov/ency/patientinstructions/ ...

  3. Tl and OSL dose response of LiF:Mg, Ti and Al{sub 2}O{sub 3}:C dosimeters using a PMMA phantom for IMRT technique quality assurance

    Energy Technology Data Exchange (ETDEWEB)

    Matsushima, L. C.; Veneziani, G. R.; Campos, L. L. [Instituto de Pesquisas Energeticas e Nucleares, Gerencia de Metrologia das Radiacoes / CNEN, Av. Lineu Prestes 2242, Cidade Universitaria, 05508-000 Sao Paulo (Brazil); Sakuraba, R. K.; Cruz, J. C., E-mail: lmatsushima@usp.br [Sociedade Beneficente Israelita Brasileira - Hospital Albert Einstein, Av. Albert Einstein 627/701, Morumbi, 05652-000 Sao Paulo (Brazil)

    2014-08-15

    The principle of IMRT is to treat a patient from a number of different directions (or continuous arcs) with beams of nonuniform fluences, which have been optimized to deliver a high dose to the target volume and an acceptably low dose to the surrounding normal structures (Khan, 2010). This study intends to provide information to the physicist regarding the application of different dosimeters type, phantoms and analysis technique for Intensity Modulated Radiation Therapy (IMRT) dose distributions evaluation. The measures were performed using dosimeters of LiF:Mg,Ti and Al{sub 2}O{sub 3}:C evaluated by techniques of thermoluminescent (Tl) and Optically Stimulated Luminescence (OSL). A polymethylmethacrylate (PMMA) phantom with five cavities, two principal target volumes considered like tumours to be treated and other three cavities to measure the scattered radiation dose was developed to carried out the measures. (Author)

  4. Fast breeder reactor research

    International Nuclear Information System (INIS)

    1975-01-01

    Full text: The meeting was attended by 15 participants from seven countries and two international organizations. The Eighth Annual Meeting of the International Working Group on Fast Reactors (IWGFR) was attended by representatives from France, Fed. Rep. Germany, Italy, Japan, United Kingdom, Union of Soviet Socialist Republics and the United States of America - countries that have made significant progress in developing the technology and physics of sodium cooled fast reactors and have extensive national programmes in this field - as well as by representatives of the Commission of the European Communities and the IAEA. The design of fast-reactor power plants is a more difficult task than developing facilities with thermal reactors. Different reactor kinetics and dynamics, a hard neutron spectrum, larger integral doses of fuel and structural material irradiation, higher core temperatures, the use of an essentially novel coolant, and, as a result of all these factors, the additional reliability and safety requirements that are imposed on the planning and operation of sodium cooled fast reactors - all these factors pose problems that can be solved comprehensively only by countries with a high level of scientific and technical development. The exchange of experience between these countries and their combined efforts in solving the fundamental problems that arise in planning, constructing and operating fast reactors are promoting technical progress and reducing the relative expenditure required for various studies on developing and introducing commercial fast reactors. For this reason, the meeting concentrated on reviewing and discussing national fast reactor programmes. The situation with regard to planning, constructing and operating fast experimental and demonstration reactors in the countries concerned, the experience accumulated in operating them, the difficulties arising during operation and ways of over-coming them, the search for optimal designs for the power

  5. Application of the thermoluminescent (TL) and optically stimulated luminescence (OSL) dosimetry techniques to determinate the isodose curves in a cancer treatment planning simulation using Volumetric Modulated Arc Therapy - VMAT

    International Nuclear Information System (INIS)

    Bravim, Amanda

    2015-01-01

    The Volumetric Modulated Arc Therapy (VMAT) is an advance technique of Intensity Modulated Radiation Therapy (IMRT). This progress is due to the continuous gantry rotation with the radiation beam modulation providing lower time of the patient treatment. This research aimed the verification of the isodose curves in a simulation of a vertebra treatment with spinal cord protection using the thermoluminescent (TL) and optically stimulated luminescence (OSL) dosimetry techniques and the LiF:Mg,Ti (TLD-100), CaS0 4 :Dy and Al 2 0 3 :C dosimeters and LiF:Mg,Ti micro dosimeters (TLD-100). The dosimeters were characterized using PMMA plates of 30 x 30 x 30 cm 3 and different thickness. All irradiations were done using Truebeam STx linear accelerator of Hospital Israelita Albert Einstein, with 6 MV photons beam. After the dosimeter characterization, they were irradiated according the specific planning simulation and using a PMMA phantom developed to VMAT measurements. This irradiation aimed to verify the isodose curves of the treatment simulation using the two dosimetry techniques. All types of dosimeters showed satisfactory results to determine the dose distribution but analysing the complexity of the isodose curves and the proximity of them, the LiF:Mg,Ti micro dosimeter showed the most appropriate for use due to its small dimensions. Regarding the best technique, as both technique showed satisfactory results, the TL technique presents less complex to be used because the most of the radiotherapy departments already have a TL laboratory. The OSL technique requires more care and greater investment in the hospital. (author)

  6. Mitigating component performance variation

    Science.gov (United States)

    Gara, Alan G.; Sylvester, Steve S.; Eastep, Jonathan M.; Nagappan, Ramkumar; Cantalupo, Christopher M.

    2018-01-09

    Apparatus and methods may provide for characterizing a plurality of similar components of a distributed computing system based on a maximum safe operation level associated with each component and storing characterization data in a database and allocating non-uniform power to each similar component based at least in part on the characterization data in the database to substantially equalize performance of the components.

  7. Preoperative fasting times: Prescribed and actual fasting times at ...

    African Journals Online (AJOL)

    The current international guidelines for preoperative fasting for elective surgery are 6 ... to determine whether this policy was being followed and patients were being starved ..... recommended fasting time, so that autonomous patients take care.

  8. Fast radiographic systems

    International Nuclear Information System (INIS)

    Domanus, J.C.

    1984-08-01

    Industrial radiography can be performed with shorter exposure times, when instead of X-ray film with lead intensifying screens the radiographic paper with fluorescent screen is used. With paper radiography one can obtain lower material, equipment, and labor costs, shorter exposure and processing times, and easier radiation protection. The speed of the radiographic inspection can also be increased by the use of fluorometallic intensifying screens together with a special brand of X-ray film. Before accepting either of the two fast radiographic systems one must be sure that they can produce radiographs of adequate image quality. Therefore an investigation was performed on that subject using ISO wire IQI's and ASTM penetrameters. The radiographic image quality was tested for aluminium and steel up to 30 mm thick using various brands of radiographic paper and X-ray film with fluorometallic screens and comparing them with fast X-ray films with lead screens. Both systems give satisfactory results. (author)

  9. Fast geometric algorithms

    International Nuclear Information System (INIS)

    Noga, M.T.

    1984-01-01

    This thesis addresses a number of important problems that fall within the framework of the new discipline of Computational Geometry. The list of topics covered includes sorting and selection, convex hull algorithms, the L 1 hull, determination of the minimum encasing rectangle of a set of points, the Euclidean and L 1 diameter of a set of points, the metric traveling salesman problem, and finding the superrange of star-shaped and monotype polygons. The main theme of all the work was to develop a set of very fast state-of-the-art algorithms that supersede any rivals in terms of speed and ease of implementation. In some cases existing algorithms were refined; for others new techniques were developed that add to the present database of fast adaptive geometric algorithms. What emerges is a collection of techniques that is successful at merging modern tools developed in analysis of algorithms with those of classical geometry

  10. The ELETTRA fast magnets

    International Nuclear Information System (INIS)

    Tommasini, D.

    1992-01-01

    The design of the fast magnets to be used to inject the electron beam into the 2 GeV storage ring Elettra is presented and discussed. Injection makes use of two types of fast magnets: the septa and the kickers. There are two identical septa magnets of the so called 'eddy current' type, which will be housed in a vacuum tank. The orbit bump is generated by four identical kicker magnets symmetrically placed around the mid-point of a single straight section: they will be in air with an internal vacuum chamber. Extensive electric and magnetic tests have been performed on prototypes, and the relevant results are presented and discussed. (author) 6 refs.; 6 figs.; 2 tabs

  11. Fast timing discriminator

    International Nuclear Information System (INIS)

    Lo, C.C.

    1977-01-01

    The processing of pulses with very fast risetimes for timing purposes involves many problems because of the large equivalent bandwidths involved. For pulses with risetimes in the 150 ps range (and full widths at half maximum (FWHM) of 400 ps) bandwidths in excess of 1GHz are required. Furthermore, these very narrow pulses with current amplitudes as small as 1 mA carry very small charges ( -12 coulomb), therefore, requiring very sensitive trigger circuits. The difficulty increases when timing characteristics in the picosecond range are sought especially when a wide input signal amplitude range causes a time-walk problem. The fast timing discriminator described has a time-walk of approximately +-75 ps over the input signal range from 80 mV to 3V. A schematic of the discriminator is included, and operation and performance are discussed

  12. Fast reactor database

    International Nuclear Information System (INIS)

    1996-02-01

    This publication contains detailed data on liquid metal cooled fast reactors (LMFRs), specifically plant parameters and design details. Each LMFR power plant is characterized by about 400 parameters, by design data and by relevant materials. The report provides general and detailed design characteristics including structural materials, data on experimental, demonstration, prototype and commercial size LMFRs. The focus is on practical issues that are useful to engineers, scientists, managers and university students and professors. The report includes updated information contained in IAEA previous publications on LMFR plant parameters: IWGRF/51 (1985) and IWGFR/80 (1991) and reflects experience gained from two consultants meetings held in Vienna (1993,1994). This compilation of data was produced by members of the IAEA International Working Group on Fast Reactors (IWGFR)

  13. Fast electrochemical actuator

    International Nuclear Information System (INIS)

    Uvarov, I V; Postnikov, A V; Svetovoy, V B

    2016-01-01

    Lack of fast and strong microactuators is a well-recognized problem in MEMS community. Electrochemical actuators can develop high pressure but they are notoriously slow. Water electrolysis produced by short voltage pulses of alternating polarity can overcome the problem of slow gas termination. Here we demonstrate an actuation regime, for which the gas pressure is relaxed just for 10 μs or so. The actuator consists of a microchamber filled with the electrolyte and covered with a flexible membrane. The membrane bends outward when the pressure in the chamber increases. Fast termination of gas and high pressure developed in the chamber are related to a high density of nanobubbles in the chamber. The physical processes happening in the chamber are discussed so as problems that have to be resolved for practical applications of this actuation regime. The actuator can be used as a driving engine for microfluidics. (paper)

  14. PHENIX Fast TOF

    Energy Technology Data Exchange (ETDEWEB)

    Soha, Aria [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Chiu, Mickey [Brookhaven National Lab. (BNL), Upton, NY (United States); Mannel, Eric [Brookhaven National Lab. (BNL), Upton, NY (United States); Stoll, Sean [Brookhaven National Lab. (BNL), Upton, NY (United States); Lynch, Don [Brookhaven National Lab. (BNL), Upton, NY (United States); Boose, Steve [Brookhaven National Lab. (BNL), Upton, NY (United States); Northacker, Dave [Brookhaven National Lab. (BNL), Upton, NY (United States); Alfred, Marcus [Howard Univ., Washington, DC (United States); Lindesay, James [Howard Univ., Washington, DC (United States); Chujo, Tatsuya [Univ. of Tsukuba (Japan); Inaba, Motoi [Univ. of Tsukuba (Japan); Nonaka, Toshihiro [Univ. of Tsukuba (Japan); Sato, Wataru [Univ. of Tsukuba (Japan); Sakatani, Ikumi [Univ. of Tsukuba (Japan); Hirano, Masahiro [Univ. of Tsukuba (Japan); Choi, Ihnjea [Univ. of Illinois, Urbana-Champaign, IL (United States)

    2014-01-15

    This is a technical scope of work (TSW) between the Fermi National Accelerator Laboratory (Fermilab) and the experimenters of PHENIX Fast TOF group who have committed to participate in beam tests to be carried out during the FY2014 Fermilab Test Beam Facility program. The goals for this test beam experiment are to verify the timing performance of the two types of time-of-flight detector prototypes.

  15. Fast diamond photoconductors

    International Nuclear Information System (INIS)

    Pochet, T.

    1993-01-01

    Preliminary results on the response of type Ib and IIa diamond photodetectors to fast laser pulse exposures at 265 and 530 nm are presented. The influence of the applied bias, the laser wavelengths and the light intensity on the detector sensitivity is studied. Also, recent measurements with 1.25 MeV gamma ray pulses are reported. (authors). 13 refs., 7 figs., 1 tab

  16. Integral fast reactor

    International Nuclear Information System (INIS)

    Chang, Y.I.

    1989-01-01

    The Integral Fast Reactor (IFR) is an innovative liquid metal reactor concept being developed at Argonne National Laboratory. It seeks to specifically exploit the inherent properties of liquid metal cooling and metallic fuel in a way that leads to substantial improvements in the characteristics of the complete reactor system. This paper describes the key features and potential advantages of the IFR concept, with emphasis on its safety characteristics

  17. Fast antihydrogen beam spectroscopy

    International Nuclear Information System (INIS)

    Neumann, R.

    1989-01-01

    The motivation for production and precision spectroscopy of antihydrogen atoms is outlined. An experimental configuration is considered, concerning laser-microwave spectroscopy of a fast hydrogen beam with characteristics similar to those of an antihydrogen beam emanating from an antiproton-positron overlap region in an antiproton storage ring. In particular, a possible experiment for the measurement of the ground state hyperfine structure splitting is described. (orig.)

  18. The Integral Fast Reactor

    International Nuclear Information System (INIS)

    Chang, Y.I.

    1988-01-01

    The Integral Fast Reactor (IFR) is an innovative liquid metal reactor concept being developed at Argonne National Laboratory. It seeks to specifically exploit the inherent properties of liquid metal cooling and metallic fuel in a way that leads to substantial improvements in the characteristics of the complete reactor system. This paper describes the key features and potential advantages of the IFR concept, with emphasis on its safety characteristics. 3 refs., 4 figs., 1 tab

  19. Fasting - the ultimate diet?

    Science.gov (United States)

    Johnstone, A M

    2007-05-01

    Adult humans often undertake acute fasts for cosmetic, religious or medical reasons. For example, an estimated 14% of US adults have reported using fasting as a means to control body weight and this approach has long been advocated as an intermittent treatment for gross refractory obesity. There are unique historical data sets on extreme forms of food restriction that give insight into the consequences of starvation or semi-starvation in previously healthy, but usually non-obese subjects. These include documented medical reports on victims of hunger strike, famine and prisoners of war. Such data provide a detailed account on how the body adapts to prolonged starvation. It has previously been shown that fasting for the biblical period of 40 days and 40 nights is well within the overall physiological capabilities of a healthy adult. However, the specific effects on the human body and mind are less clearly documented, either in the short term (hours) or in the longer term (days). This review asks the following three questions, pertinent to any weight-loss therapy, (i) how effective is the regime in achieving weight loss, (ii) what impact does it have on psychology? and finally, (iii) does it work long-term?

  20. ADT fast losses MD

    CERN Document Server

    Priebe, A; Dehning, B; Redaelli, S; Salvachua Ferrando, BM; Sapinski, M; Solfaroli Camillocci, M; Valuch, D

    2013-01-01

    The fast beam losses in the order of 1 ms are expected to be a potential major luminosity limitation for higher beam energies after the LHC long shutdown (LS1). Therefore a Quench Test is planned in the winter 2013 to estimate the quench limit in this timescale and revise the current models. This experiment was devoted to determination the LHC Transverse Damper (ADT) as a system for fast losses induction. A non-standard operation of the ADT was used to develop the beam oscillation instead of suppressing them. The sign flip method had allowed us to create the fast losses within several LHC turns at 450 GeV during the previous test (26th March 2012). Thus, the ADT could be potentially used for the studies of the UFO ("Unidentied Falling Object") impact on the cold magnets. Verification of the system capability and investigations of the disturbed beam properties were the main objectives of this MD. During the experiment, the pilot bunches of proton beam were excited independently in the horizontal and vertical ...

  1. Fast Light Optical Gyroscopes

    Science.gov (United States)

    Smith, David D.

    2015-01-01

    Next-generation space missions are currently constrained by existing spacecraft navigation systems which are not fully autonomous. These systems suffer from accumulated dead-reckoning errors and must therefore rely on periodic corrections provided by supplementary technologies that depend on line-of-sight signals from Earth, satellites, or other celestial bodies for absolute attitude and position determination, which can be spoofed, incorrectly identified, occluded, obscured, attenuated, or insufficiently available. These dead-reckoning errors originate in the ring laser gyros themselves, which constitute inertial measurement units. Increasing the time for standalone spacecraft navigation therefore requires fundamental improvements in gyroscope technologies. One promising solution to enhance gyro sensitivity is to place an anomalous dispersion or fast light material inside the gyro cavity. The fast light essentially provides a positive feedback to the gyro response, resulting in a larger measured beat frequency for a given rotation rate as shown in figure 1. Game Changing Development has been investing in this idea through the Fast Light Optical Gyros (FLOG) project, a collaborative effort which began in FY 2013 between NASA Marshall Space Flight Center (MSFC), the U.S. Army Aviation and Missile Research, Development, and Engineering Center (AMRDEC), and Northwestern University. MSFC and AMRDEC are working on the development of a passive FLOG (PFLOG), while Northwestern is developing an active FLOG (AFLOG). The project has demonstrated new benchmarks in the state of the art for scale factor sensitivity enhancement. Recent results show cavity scale factor enhancements of approx.100 for passive cavities.

  2. Metabolic Effects of Intermittent Fasting.

    Science.gov (United States)

    Patterson, Ruth E; Sears, Dorothy D

    2017-08-21

    The objective of this review is to provide an overview of intermittent fasting regimens, summarize the evidence on the health benefits of intermittent fasting, and discuss physiological mechanisms by which intermittent fasting might lead to improved health outcomes. A MEDLINE search was performed using PubMed and the terms "intermittent fasting," "fasting," "time-restricted feeding," and "food timing." Modified fasting regimens appear to promote weight loss and may improve metabolic health. Several lines of evidence also support the hypothesis that eating patterns that reduce or eliminate nighttime eating and prolong nightly fasting intervals may result in sustained improvements in human health. Intermittent fasting regimens are hypothesized to influence metabolic regulation via effects on (a) circadian biology, (b) the gut microbiome, and (c) modifiable lifestyle behaviors, such as sleep. If proven to be efficacious, these eating regimens offer promising nonpharmacological approaches to improving health at the population level, with multiple public health benefits.

  3. Fast orthogonal transforms and generation of Brownian paths.

    Science.gov (United States)

    Leobacher, Gunther

    2012-04-01

    We present a number of fast constructions of discrete Brownian paths that can be used as alternatives to principal component analysis and Brownian bridge for stratified Monte Carlo and quasi-Monte Carlo. By fast we mean that a path of length [Formula: see text] can be generated in [Formula: see text] floating point operations. We highlight some of the connections between the different constructions and we provide some numerical examples.

  4. Neighborhood fast food availability and fast food consumption.

    Science.gov (United States)

    Oexle, Nathalie; Barnes, Timothy L; Blake, Christine E; Bell, Bethany A; Liese, Angela D

    2015-09-01

    Recent nutritional and public health research has focused on how the availability of various types of food in a person's immediate area or neighborhood influences his or her food choices and eating habits. It has been theorized that people living in areas with a wealth of unhealthy fast-food options may show higher levels of fast-food consumption, a factor that often coincides with being overweight or obese. However, measuring food availability in a particular area is difficult to achieve consistently: there may be differences in the strict physical locations of food options as compared to how individuals perceive their personal food availability, and various studies may use either one or both of these measures. The aim of this study was to evaluate the association between weekly fast-food consumption and both a person's perceived availability of fast-food and an objective measure of fast-food presence - Geographic Information Systems (GIS) - within that person's neighborhood. A randomly selected population-based sample of eight counties in South Carolina was used to conduct a cross-sectional telephone survey assessing self-report fast-food consumption and perceived availability of fast food. GIS was used to determine the actual number of fast-food outlets within each participant's neighborhood. Using multinomial logistic regression analyses, we found that neither perceived availability nor GIS-based presence of fast-food was significantly associated with weekly fast-food consumption. Our findings indicate that availability might not be the dominant factor influencing fast-food consumption. We recommend using subjective availability measures and considering individual characteristics that could influence both perceived availability of fast food and its impact on fast-food consumption. If replicated, our findings suggest that interventions aimed at reducing fast-food consumption by limiting neighborhood fast-food availability might not be completely effective

  5. Serum Lipid Profile: Fasting or Non-fasting?

    OpenAIRE

    Nigam, P. K.

    2010-01-01

    Serum lipid profile has now become almost a routine test. It is usually done in fasting state due to certain limitations in non-fasting serum sample. In the recent past efforts have been made to simplify blood sampling by replacing fasting lipid profile with non-fasting lipid profile. However, fasting specimen is preferred if cardiovascular risk assessment is based on total cholesterol, LDL cholesterol or non-HDL cholesterol. A lot has yet to be done in this area. Till then we have to believe...

  6. System design considerations for fast-neutron interrogation systems

    International Nuclear Information System (INIS)

    Micklich, B.J.; Curry, B.P.; Fink, C.L.; Smith, D.L.; Yule, T.J.

    1993-01-01

    Nonintrusive interrogation techniques that employ fast neutrons are of interest because of their sensitivity to light elements such as carbon, nitrogen, and oxygen. The primary requirement of a fast-neutron inspection system is to determine the value of atomic densities, or their ratios, over a volumetric grid superimposed on the object being interrogated. There are a wide variety of fast-neutron techniques that can provide this information. The differences between the various nuclear systems can be considered in light of the trade-offs relative to the performance requirements for each system's components. Given a set of performance criteria, the operational requirements of the proposed nuclear systems may also differ. For instance, resolution standards will drive scanning times and tomographic requirements, both of which vary for the different approaches. We are modelling a number of the fast-neutron interrogation techniques currently under consideration, to include Fast Neutron Transmission Spectroscopy (FNTS), Pulsed Fast Neutron Analysis (PFNA), and its variant, 14-MeV Associated Particle Imaging (API). The goals of this effort are to determine the component requirements for each technique, identify trade-offs that system performance standards impose upon those component requirements, and assess the relative advantages and disadvantages of the different approaches. In determining the component requirements, we will consider how they are driven by system performance standards, such as image resolution, scanning time, and statistical uncertainty. In considering the trade-offs between system components, we concentrate primarily on those which are common to all approaches, for example: source characteristics versus detector array requirements. We will then use the analysis to propose some figures-of-merit that enable performance comparisons between the various fast-neutron systems under consideration. The status of this ongoing effort is presented

  7. Hispanics in Fast Food Jobs.

    Science.gov (United States)

    Charner, Ivan; Fraser, Bryna Shore

    A study examined the employment of Hispanics in the fast-food industry. Data were obtained from a national survey of employees at 279 fast-food restaurants from seven companies in which 194 (4.2 percent) of the 4,660 respondents reported being Hispanic. Compared with the total sample, Hispanic fast-food employees were slightly less likely to be…

  8. Fast reactors: potential for power

    International Nuclear Information System (INIS)

    1983-02-01

    The subject is discussed as follows: basic facts about conventional and fast reactors; uranium economy; plutonium and fast reactors; cooling systems; sodium coolant; safety engineering; handling and recycling plutonium; safeguards; development of fast reactors in Britain and abroad; future progress. (U.K.)

  9. A review of fast reactor progress in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Tomabechi, K [Power Reactor and Nuclear Fuel Development Corporation, Tokyo (Japan)

    1978-07-01

    The fast reactor development project in Japan is continuing at a slightly increased scale of effort in budget. The total budget for LMFBR development for fiscal year 1978 was 24 billion yen. In August 1977 major industries engaged in LMFBR have set up an office where design work can be jointly conducted. Highlights and topics of the fast reactor development activities cover description of JOYO reactor, its first criticality experiment, and the prototype fast breeder MONJU. Research and development programmes dealt with fission products release and its possible interaction with the soodium coolant, inspection of reactor components, experiments simulating sodium leakage, development of steam generator.

  10. Testing experience with fast flux test facility

    International Nuclear Information System (INIS)

    Noordhoff, B.H.; McGough, C.B.; Nolan, J.E.

    1975-01-01

    Early FFTF project planning emphasized partial and full-scale testing of major reactor and plant prototype components under expected environmental conditions, excluding radiation fields. Confirmation of component performance during FFTF service was considered essential before actual FFTF startup, to provide increased assurance against FFTF startup delays or operational difficulties and downtime. Several new sodium facilities were constructed, and confirmation tests on the prototype components are now in progress. Test conditions and results to date are reported for the primary pump, intermediate heat exchanger, sodium-to-air dump heat exchanger, large and small sodium valves, purification cold trap, in-vessel handling machine, instrument tree, core restraint, control rod system, low-level flux monitor, closed loop ex-vessel machine, refueling equipment, and selected maintenance equipment. The significance and contribution of these tests to the FFTF and Liquid Metal Fast Breeder Reactor (LMFBR) program are summarized. (U.S.)

  11. Reusable Component Services

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Reusable Component Services (RCS) is a super-catalog of components, services, solutions and technologies that facilitates search, discovery and collaboration in...

  12. Software component quality evaluation

    Science.gov (United States)

    Clough, A. J.

    1991-01-01

    The paper describes a software inspection process that can be used to evaluate the quality of software components. Quality criteria, process application, independent testing of the process and proposed associated tool support are covered. Early results indicate that this technique is well suited for assessing software component quality in a standardized fashion. With automated machine assistance to facilitate both the evaluation and selection of software components, such a technique should promote effective reuse of software components.

  13. Reactor component automatic grapple

    International Nuclear Information System (INIS)

    Greenaway, P.R.

    1982-01-01

    A grapple for handling nuclear reactor components in a medium such as liquid sodium which, upon proper seating and alignment of the grapple with the component as sensed by a mechanical logic integral to the grapple, automatically seizes the component. The mechanical logic system also precludes seizure in the absence of proper seating and alignment. (author)

  14. Repurposing learning object components

    NARCIS (Netherlands)

    Verbert, K.; Jovanovic, J.; Gasevic, D.; Duval, E.; Meersman, R.

    2005-01-01

    This paper presents an ontology-based framework for repurposing learning object components. Unlike the usual practice where learning object components are assembled manually, the proposed framework enables on-the-fly access and repurposing of learning object components. The framework supports two

  15. Fast reactors in nuclear power

    Energy Technology Data Exchange (ETDEWEB)

    Kazachkovskii, O

    1981-02-01

    The possible applications are discussed of fast reactor nuclear power plants. Basic differences are explained in fast and thermal reactors, mainly with a view to nuclear fuel utilization. Discussed in more detail are the problems of nuclear fuel reproduction and the nost important technical problems of fast reactors. Flow charts are shown of heat transfer for fast reactors BN-350 (loop design) and BN-600 (integral coolant circuit design). Main specifications are given for demonstration and power fast reactors in operation, under construction and in project-stage.

  16. Knowledge management in fast reactors

    International Nuclear Information System (INIS)

    Kuriakose, K.K.; Satya Murty, S.A.V.; Swaminathan, P.; Raj, Baldev

    2010-01-01

    This paper highlights the work that is being carried out in Knowledge Management of Fast Reactors at Indira Gandhi Centre for Atomic Research (IGCAR) including a few examples of how the knowledge acquired because of various incidents in the initial years has been utilized for the successful operation of Fast Breeder Test Reactor. It also briefly refers to the features of the IAEA initiative on the preservation of Knowledge in the area of Fast Reactors in the form of 'Fast Reactor Knowledge Organization System' (FR-KOS), which is based on a taxonomy for storage and mining of Fast Reactor Knowledge. (author)

  17. Fast photomultiplier ELUP 151

    International Nuclear Information System (INIS)

    Andreeva, L.I.; Belokon', V.A.; Krasin, E.V.

    1992-01-01

    High-velocity photomultiplier is described. The latter is recommended to be used in nuclear physics, plasma physics, nuclear medical diagnostics and at measurement of fast-occurring process parameters. Main specifications are as follows: range of spectral sensitivity - 0.2-0.7 μm; limit of dinamic characteristic linearity - up to 5A; dark current at +20 deg C ambient temperature - maximum 10-8A, time of anode pulse growth - maximum 8 ns; photocathode quantum yield in the maximum of spectral characteristic (λ max =380-420 nm) - 24-26%; supply voltage - 4-5 kV

  18. Fast neutron dosimetry

    International Nuclear Information System (INIS)

    DeLuca, P.M. Jr.; Pearson, D.W.

    1992-01-01

    This progress report concentrates on two major areas of dosimetry research: measurement of fast neutron kerma factors for several elements for monochromatic and white spectrum neutron fields and determination of the response of thermoluminescent phosphors to various ultra-soft X-ray energies and beta-rays. Dr. Zhixin Zhou from the Shanghai Institute of Radiation Medicine, People's Republic of China brought with him special expertise in the fabrication and use of ultra-thin TLD materials. Such materials are not available in the USA. The rather unique properties of these materials were investigated during this grant period

  19. The fast encryption package

    Science.gov (United States)

    Bishop, Matt

    1988-01-01

    The organization of some tools to help improve passwork security at a UNIX-based site is described along with how to install and use them. These tools and their associated library enable a site to force users to pick reasonably safe passwords (safe being site configurable) and to enable site management to try to crack existing passworks. The library contains various versions of a very fast implementation of the Data Encryption Standard and of the one-way encryption functions used to encryp the password.

  20. Fast breeder reactors

    International Nuclear Information System (INIS)

    Ollier, J.L.

    1987-01-01

    The first industrial-scale fast breeder reactor (FBR) is the Superphenix I at Crays-Melville. It was designed and built by Novatome, a French company, and Ansaldo, an Italian company. The advantages of FBRs are summarized. The status of Superphenix and the testing schedule is given. The stages in its power escalation in 1986 are given. The article is optimistic about the future for FBRs and expects FBRs to take over from PWRs at the beginning of the 21st Century. To achieve economic viability, European financial cooperation for the research and development programme is advocated. (UK)

  1. Sodium cooled fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hokkyo, N; Inoue, K; Maeda, H

    1968-11-21

    In a sodium cooled fast neutron reactor, an ultrasonic generator is installed at a fuel assembly hold-down mechanism positioned above a blanket or fission gas reservoir located above the core. During operation of the reactor an ultrsonic wave of frequency 10/sup 3/ - 10/sup 4/ Hz is constantly transmitted to the core to resonantly inject the primary bubble with ultrasonic energy to thereby facilitate its growth. Hence, small bubbles grow gradually to prevent the sudden boiling of sodium if an accident occurs in the cooling system during operation of the reactor.

  2. Fast multichannel scaler

    International Nuclear Information System (INIS)

    Okayasu, T.; Takeuchi, S.; Nagai, S.

    1987-01-01

    A fast multichannel scaler achieving the minimum dwell time of 50 ns is described. The dead time due to memory cycle is eliminated by 4-phase operation of parallel-4 groups of counter RAMs. The MCS has 4 k channels in total. Differential nonlinearity is less than 0.4%. If an input pulse arrives near the channel boundary, it is caught temporarily for both channels and then sorted to go into a proper channel. Thus, the dead time near the channel boundary is also eliminated

  3. Nuclear data for advanced fast reactors

    International Nuclear Information System (INIS)

    Rabotnov, N.S.

    2001-01-01

    Interest revives to fast reactors as the only proven technology obviously able of satisfying human energy needs for the next millennium by using full energy content of both natural uranium resources and of vast stocks of depleted uranium. This interest stimulates revision and improvement of fast reactor ND. Progress in reactor calculations accuracy due to better codes and much faster computers also increases relative importance of the input data uncertainties, especially in case of small reactivity margin and fuels of equilibrium compositions. The main objects of corresponding R and D efforts should be minor actinides and heavy liquid metal coolant. Data error bands and covariance information also gain importance as necessary components of neutron physics calculations. (author)

  4. Fast ions and momentum transport in JET tokamak plasmas

    International Nuclear Information System (INIS)

    Salmi, A.

    2012-01-01

    Fast ions are an inseparable part of fusion plasmas. They can be generated using electromagnetic waves or injected into plasmas as neutrals to heat the bulk plasma and to drive toroidal rotation and current. In future power plants fusion born fast ions deliver the main heating into the plasma. Understanding and controlling the fast ions is of crucial importance for the operation of a power plant. Furthermore, fast ions provide ways to probe the properties of the thermal plasma and get insight of its confinement properties. In this thesis, numerical code packages are used and developed to simulate JET experiments for a range of physics issues related to fast ions. Namely, the clamping fast ion distribution at high energies with RF heating, fast ion ripple torque generation and the toroidal momentum transport properties using NBI modulation technique are investigated. Through a comparison of numerical simulations and the JET experimental data it is shown that the finite Larmor radius effects in ion cyclotron resonance heating are important and that they can prevent fast ion tail formation beyond certain energy. The identified mechanism could be used for tailoring the fast ion distribution in future experiments. Secondly, ASCOT simulations of NBI ions in a ripple field showed that most of the reduction of the toroidal rotation that has been observed in the JET enhanced ripple experiments could be attributed to fast ion ripple torque. Finally, fast ion torque calculations together with momentum transport analysis have led to the conclusion that momentum transport in not purely diffusive but that a convective component, which increases monotonically in radius, exists in a wide range of JET plasmas. Using parameter scans, the convective transport has been shown to be insensitive to collisionality and q-profile but to increase strongly against density gradient. (orig.)

  5. Fast ions and momentum transport in JET tokamak plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Salmi, A.

    2012-07-01

    Fast ions are an inseparable part of fusion plasmas. They can be generated using electromagnetic waves or injected into plasmas as neutrals to heat the bulk plasma and to drive toroidal rotation and current. In future power plants fusion born fast ions deliver the main heating into the plasma. Understanding and controlling the fast ions is of crucial importance for the operation of a power plant. Furthermore, fast ions provide ways to probe the properties of the thermal plasma and get insight of its confinement properties. In this thesis, numerical code packages are used and developed to simulate JET experiments for a range of physics issues related to fast ions. Namely, the clamping fast ion distribution at high energies with RF heating, fast ion ripple torque generation and the toroidal momentum transport properties using NBI modulation technique are investigated. Through a comparison of numerical simulations and the JET experimental data it is shown that the finite Larmor radius effects in ion cyclotron resonance heating are important and that they can prevent fast ion tail formation beyond certain energy. The identified mechanism could be used for tailoring the fast ion distribution in future experiments. Secondly, ASCOT simulations of NBI ions in a ripple field showed that most of the reduction of the toroidal rotation that has been observed in the JET enhanced ripple experiments could be attributed to fast ion ripple torque. Finally, fast ion torque calculations together with momentum transport analysis have led to the conclusion that momentum transport in not purely diffusive but that a convective component, which increases monotonically in radius, exists in a wide range of JET plasmas. Using parameter scans, the convective transport has been shown to be insensitive to collisionality and q-profile but to increase strongly against density gradient. (orig.)

  6. Fast delta Hadamard transform

    International Nuclear Information System (INIS)

    Fenimore, E.E.; Weston, G.S.

    1981-01-01

    In many fields (e.g., spectroscopy, imaging spectroscopy, photoacoustic imaging, coded aperture imaging) binary bit patterns known as m sequences are used to encode (by multiplexing) a series of measurements in order to obtain a larger throughput. The observed measurements must be decoded to obtain the desired spectrum (or image in the case of coded aperture imaging). Decoding in the past has used a technique called the fast Hadamard transform (FHT) whose chief advantage is that it can reduce the computational effort from N 2 multiplies of N log 2 N additions or subtractions. However, the FHT has the disadvantage that it does not readily allow one to sample more finely than the number of bits used in the m sequence. This can limit the obtainable resolution and cause confusion near the sample boundaries (phasing errors). Both 1-D and 2-D methods (called fast delta Hadamard transforms, FDHT) have been developed which overcome both of the above limitations. Applications of the FDHT are discussed in the context of Hadamard spectroscopy and coded aperture imaging with uniformly redundant arrays. Special emphasis has been placed on how the FDHT can unite techniques used by both of these fields into the same mathematical basis

  7. Fast Fourier transform telescope

    International Nuclear Information System (INIS)

    Tegmark, Max; Zaldarriaga, Matias

    2009-01-01

    We propose an all-digital telescope for 21 cm tomography, which combines key advantages of both single dishes and interferometers. The electric field is digitized by antennas on a rectangular grid, after which a series of fast Fourier transforms recovers simultaneous multifrequency images of up to half the sky. Thanks to Moore's law, the bandwidth up to which this is feasible has now reached about 1 GHz, and will likely continue doubling every couple of years. The main advantages over a single dish telescope are cost and orders of magnitude larger field-of-view, translating into dramatically better sensitivity for large-area surveys. The key advantages over traditional interferometers are cost (the correlator computational cost for an N-element array scales as Nlog 2 N rather than N 2 ) and a compact synthesized beam. We argue that 21 cm tomography could be an ideal first application of a very large fast Fourier transform telescope, which would provide both massive sensitivity improvements per dollar and mitigate the off-beam point source foreground problem with its clean beam. Another potentially interesting application is cosmic microwave background polarization.

  8. The integral fast reactor

    International Nuclear Information System (INIS)

    Till, C.E.

    1987-01-01

    On April 3rd, 1986, two dramatic demonstrations of the inherent capability of sodium-cooled fast reactors to survive unprotected loss of cooling accidents were carried out on the experimental sodium-cooled power reactor, EBR-II, on the Idaho site of Argonne National Laboratory. Transients potentially of the most serious kind, one an unprotected loss of flow, the other an unprotected loss of heat sink, both initiated from full power. In both cases the reactor quietly shut itself down, without damage of any kind. These tests were a part of the on-going development program at Argonne to develop an advanced reactor with significant new inherent safety characteristics. Called the Integral Fast Reactor, or IFR, the basic thrust is to develop everything that is needed for a complete nuclear power system - reactor, closed fuel cycle, and waste processing - as a single optimized entity, and, for simplicity in concept, as an integral part of a single plant. The particular selection of reactor materials emphasizes inherent safety characteristics and also makes possible a simplified closed fuel cycle and waste process improvements

  9. The integral fast reactor

    International Nuclear Information System (INIS)

    Till, C.E.

    1987-01-01

    On April 3rd, 1986, two demonstrations of the inherent capability of sodium-cooled fast reactors to survive unprotected loss of cooling accidents were carried out on the experimental sodium-cooled power reactor, EBR-II, on the Idaho site of Argonne National Laboratory. Transients potentially of the most serious kind, one an unprotected loss of flow, the other an unprotected loss of heat sink, both initiated from full power. In both cases the reactor quietly shut itself down, without damage of any kind. These tests were a part of the on-going development program at Argonne to develop an advanced reactor with significant new inherent safety characteristics. Called the integral fast reactor, or IFR, the basic thrust is to develop everything that is needed for a complete nuclear power system - reactor, closed fuel cycle, and waste processing - as a single optimized entity, and, for simplicity in concept, as an integral part of a single plant. The particular selection of reactor materials emphasizes inherent safety characteristics also makes possible a simplified close fuel cycle and waste process improvements. The paper describes the IFR concept, the inherent safety, tests, and status of IFR development today

  10. Development and operation of fast protection for KSTAR

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Jaesic, E-mail: hjaesic@nfri.re.kr; Lee, Woongryol; Lee, Taegu; Han, Hyunsun; Han, Sang-Hee; Park, Kaprai

    2016-11-15

    Highlights: • The evolution of KSTAR machine interlock system. • The evolution of KSTAR fast interlock. • The fast interlock interface. • The operation results of the fast interlock. - Abstract: Protection for the Korea superconducting tokamak advanced research (KSTAR) is somewhat more complicated than for the previous tokomak generation. External reasons for this increased complexity are the initial and maintenance costs, and internal reasons relate to various characteristics of the tokamak and long pulse operation. KSTAR has two protection mechanisms: the device protection system protects damage to superconducting coils etc. from events within the other systems, and the fast protection system protects the internal vacuum vessel components against damage from heating and the long pulse plasma. The fast protection system initially contained the plasma control system (PCS), central control system (CCS), and the heating devices. In 2012, a fast interlock interface was implemented for PCS fail-safe. This detected the absence of plasma current using the diagnostic signals and discharge operation gate windows of the timing synchronized system (TSS), and activates the operation gates and heating stop from the CCS. Additional fast interlock logic was implemented to reduce damage to the plasma facing components (PFC) and other materials by overheating and improper operational state of heating systems after starting the discharge sequence. However, the fast interlock interface system has failed to protect the heating during PCS malfunctions since 2013. This paper introduces the KSTAR protection system, and describes the fast protection interface, with testing and operational results, then discusses future plans for a more effective and safer protection system.

  11. Islamic fasting and multiple sclerosis

    Science.gov (United States)

    2014-01-01

    Background Month-long daytime Ramadan fasting pose s major challenges to multiple sclerosis (MS) patients in Muslim countries. Physicians should have practical knowledge on the implications of fasting on MS. We present a summary of database searches (Cochrane Database of Systematic Reviews, PubMed) and a mini-symposium on Ramadan fasting and MS. In this symposium, we aimed to review the effect of fasting on MS and suggest practical guidelines on management. Discussion In general, fasting is possible for most stable patients. Appropriate amendment of drug regimens, careful monitoring of symptoms, as well as providing patients with available evidence on fasting and MS are important parts of management. Evidence from experimental studies suggests that calorie restriction before disease induction reduces inflammation and subsequent demyelination and attenuates disease severity. Fasting does not appear to have unfavorable effects on disease course in patients with mild disability (Expanded Disability Status Scale (EDSS) score ≤3). Most experts believed that during fasting (especially in summer), some MS symptoms (fatigue, fatigue perception, dizziness, spasticity, cognitive problems, weakness, vision, balance, gait) might worsen but return to normal levels during feasting. There was a general consensus that fasting is not safe for patients: on high doses of anti-convulsants, anti-spastics, and corticosteroids; with coagulopathy or active disease; during attacks; with EDSS score ≥7. Summary These data suggest that MS patients should have tailored care. Fasting in MS patients is a challenge that is directly associated with the spiritual belief of the patient. PMID:24655543

  12. Fast Food Jobs. National Study of Fast Food Employment.

    Science.gov (United States)

    Charner, Ivan; Fraser, Bryna Shore

    A study examined employment in the fast-food industry. The national survey collected data from employees at 279 fast-food restaurants from seven companies. Female employees outnumbered males by two to one. The ages of those fast-food employees in the survey sample ranged from 14 to 71, with fully 70 percent being in the 16- to 20-year-old age…

  13. fastNGSadmix

    DEFF Research Database (Denmark)

    Jørsboe, Emil; Hanghøj, Kristian Ebbesen; Albrechtsen, Anders

    2017-01-01

    Motivation Estimation of admixture proportions and principal component analysis (PCA) are fundamental tools in populations genetics. However, applying these methods to low- or mid-depth sequencing data without taking genotype uncertainty into account can introduce biases. Results Here we present...

  14. Not so fast

    DEFF Research Database (Denmark)

    Marras, Stefano; Noda, Takuji; Steffensen, John Fleng

    2015-01-01

    within which one may expect maximal speeds both by predators and prey. Beyond speed, however, an important component determining the outcome of predator-prey encounters is unsteady swimming (i.e., turning and accelerating). Although large predators are faster than their small prey, the latter show higher...

  15. Supply chain components

    OpenAIRE

    Vieraşu, T.; Bălăşescu, M.

    2011-01-01

    In this article I will go through three main logistics components, which are represented by: transportation, inventory and facilities, and the three secondary logistical components: information, production location, price and how they determine performance of any supply chain. I will discuss then how these components are used in the design, planning and operation of a supply chain. I will also talk about some obstacles a supply chain manager may encounter.

  16. Supply chain components

    Directory of Open Access Journals (Sweden)

    Vieraşu, T.

    2011-01-01

    Full Text Available In this article I will go through three main logistics components, which are represented by: transportation, inventory and facilities, and the three secondary logistical components: information, production location, price and how they determine performance of any supply chain. I will discuss then how these components are used in the design, planning and operation of a supply chain. I will also talk about some obstacles a supply chain manager may encounter.

  17. Control component retainer

    International Nuclear Information System (INIS)

    Walton, L.A.; King, R.A.

    1983-01-01

    An apparatus is described for retaining an undriven control component assembly disposed in a fuel assembly in a nuclear reactor of the type having a core grid plate. The first part of the mechanism involves a housing for the control component and the second part is a brace with a number of arms that reach under the grid plate. The brace and the housing are coupled together to firmly hold the control components in place even under strong flows of th coolant

  18. Liquid metal cooled fast breeder nuclear reactor

    International Nuclear Information System (INIS)

    Scott, D.

    1979-01-01

    A liquid metal cooled fast breeder nuclear reactor has a core comprising a plurality of fuel assemblies supported on a diagrid and submerged in a pool of liquid metal coolant within a containment vessel, the diagrid being of triple component construction and formed of a short cylindrical plenum mounted on a conical undershell and loosely embraced by a fuel store carrier. The plenum merely distributes coolant through the fuel assemblies, the load of the assemblies being carried by the undershell by means of struts which penetrate the plenum. The reactor core, fuel store carrier and undershell provide secondary containment for the plenum. (UK)

  19. A fast charge integrating and shaping circuit

    International Nuclear Information System (INIS)

    Kulka, Z.; Szoncso, F.

    1990-01-01

    The development of a low cost fast charge integrating and shaping circuit (FCISC) was motivated by the need for an interface between the photomultipliers of an existing hadronic calorimeter and recently developed new readout electronics designed to match the output of small ionization chambers for the upgraded UA1 detector at the CERN proton-antiproton collider. This paper describes the design principles of gated and ungated charge integrating and shaping circuits. An FCISC prototype using discrete components was made and its properties were determined with a computerized test setup. Finally an SMD implementation of the FCISC is presented and the performance is reported. (orig.)

  20. Materials analysis fast ions

    CERN Document Server

    Denker, A; Rauschenberg, J; Röhrich, J; Strub, E

    2006-01-01

    Materials analysis with ion beams exploits the interaction of ions with the electrons and nuclei in the sample. Among the vast variety of possible analytical techniques available with ion beams we will restrain to ion beam analysis with ion beams in the energy range from one to several MeV per mass unit. It is possible to use either the back-scattered projectiles (RBS – Rutherford Back Scattering) or the recoiled atoms itself (ERDA – Elastic Recoil Detection Analysis) from the elastic scattering processes. These techniques allow the simultaneous and absolute determination of stoichiometry and depth profiles of the detected elements. The interaction of the ions with the electrons in the sample produces holes in the inner electronic shells of the sample atoms, which recombine and emit X-rays characteristic for the element in question. Particle Induced X-ray Emission (PIXE) has shown to be a fast technique for the analysis of elements with an atomic number above 11.

  1. Fast multilevel radiative transfer

    International Nuclear Information System (INIS)

    Paletou, Frederic; Leger, Ludovick

    2007-01-01

    The vast majority of recent advances in the field of numerical radiative transfer relies on approximate operator methods better known in astrophysics as Accelerated Lambda-Iteration (ALI). A superior class of iterative schemes, in term of rates of convergence, such as Gauss-Seidel and successive overrelaxation methods were therefore quite naturally introduced in the field of radiative transfer by Trujillo Bueno and Fabiani Bendicho [A novel iterative scheme for the very fast and accurate solution of non-LTE radiative transfer problems. Astrophys J 1995;455:646]; it was thoroughly described for the non-LTE two-level atom case. We describe hereafter in details how such methods can be generalized when dealing with non-LTE unpolarised radiation transfer with multilevel atomic models, in monodimensional geometry

  2. Fast reactor programme

    International Nuclear Information System (INIS)

    Hoekstra, E.K.

    1976-11-01

    Estimated reactivity effects of fission products in the SNR-300 fast breeder are given. Neutron cross sections of 127 I and 129 I are also given. Results of the in-pile canning failure experiments on fuel pins R54-F35 and F39 are discussed. Sinter experiments using mixed UC-UN powders are reported. Results of tensile tests on high-dose and low-dose irradiated specimens of 18Cr1 1Ni stainless steel (DIN 1.4948) used in the SNR-300 reactor vessel are given. It is shown that the aerosol behaviour in condensing sodium vapour can be described by the same MADCA model developed for the decay of aerosols in condensing water vapour. Results of heat transfer measurements in the electrically heated 28-rod bundle under liquid-phase and subsequently under two-phase conditions are commented on

  3. The Integral Fast Reactor

    International Nuclear Information System (INIS)

    Till, C.E.

    1985-01-01

    During the past two years, scientists from Argonne have developed an advanced breeder reactor with a closed self contained fuel cycle. The Integral Fast Reactor (IFR) is a new reactor concept, adaptable to a variety of designs, that is based on a fuel cycle radically different from the CRBR line of breeder development. The essential features of the IFR are metal fuel, pool layout, and pyro- and electro-reprocessing in a facility integral with the reactor plant. The IFR shows promise to provide an inexhaustible, safe, economic, environmentally acceptable, and diversion resistant source of nuclear power. It shows potential for major improvement in all of the areas that have led to concern about nuclear power

  4. Component design for LMFBR's

    International Nuclear Information System (INIS)

    Fillnow, R.H.; France, L.L.; Zerinvary, M.C.; Fox, R.O.

    1975-01-01

    Just as FFTF has prototype components to confirm their design, FFTF is serving as a prototype for the design of the commercial LMFBR's. Design and manufacture of critical components for the FFTF system have been accomplished primarily using vendors with little or no previous experience in supplying components for high temperature sodium systems. The exposure of these suppliers, and through them a multitude of subcontractors, to the requirements of this program has been a necessary and significant step in preparing American industry for the task of supplying the large mechanical components required for commercial LMFBR's

  5. Hot gas path component

    Science.gov (United States)

    Lacy, Benjamin Paul; Kottilingam, Srikanth Chandrudu; Porter, Christopher Donald; Schick, David Edward

    2017-09-12

    Various embodiments of the disclosure include a turbomachine component. and methods of forming such a component. Some embodiments include a turbomachine component including: a first portion including at least one of a stainless steel or an alloy steel; and a second portion joined with the first portion, the second portion including a nickel alloy including an arced cooling feature extending therethrough, the second portion having a thermal expansion coefficient substantially similar to a thermal expansion coefficient of the first portion, wherein the arced cooling feature is located within the second portion to direct a portion of a coolant to a leakage area of the turbomachine component.

  6. Fast reactors and nonproliferation

    International Nuclear Information System (INIS)

    Orlov, V.V.

    1997-01-01

    1.Three aspects of nonproliferation relevant to nuclear power are: Pu buildup in NPP spent fuel cooling ponds (∼ 104 t in case of consumption of ∼ 107 t cheap uranium). Danger of illegal radiochemical extraction of Pu for weapons production; Pu extraction from NPP fuel at the plants available in nuclear countries, its burning along with weapon-grade Pu in NPP reactors or in special-purpose burners; increased hazard of nuclear weapons sprawl with breeders and closed fuel cycle technology spreading all over the world. 2.The latter is one of major obstacles to creation of large-scale nuclear power. 3.Nuclear power of the first stage using 235 U will be able to meet the demands of certain fuel-deficient countries and regions, replacing ∼ 5-10% of conventional fuels in the global consumption for a number of decades. 4.Fast reactors of the first generation and the currently employed fuel technology are far from exhausting their potential for solving economic problems and meeting the challenges of safety, radioactive waste and nonproliferation. Development of large-scale nuclear power will become an option accepted by society for solving energy problems in the following century, provided a breeder technology is elaborated and demonstrated in the next 15-20 years, which would comply with the totality of the following requirement: full internal Pu breeding deterministic elimination of severe accidents involving fuel damage and high radioactivity releases: fast runaway, loss of coolant, fires, steam and hydrogen explosions, etc.; reaching a balance between radioactive wastes disposed of and uranium mined in terms of radiation hazard; technology of closed fuel cycle preventing its use for Pu extraction and permitting physical protection from fuel thefts;economic competitiveness of nuclear power for most of countries and regions, i.e. primarily the cost of NPPs with fat reactors is to be below the cost of modern LWR plants, etc

  7. Promotion and Fast Food Demand

    OpenAIRE

    Timothy J. Richards; Luis Padilla

    2009-01-01

    Many believe that fast food promotion is a significant cause of the obesity epidemic in North America. Industry members argue that promotion only reallocates brand shares and does not increase overall demand. We study the effect of fast food promotion on market share and total demand by estimating a discrete / continuous model of fast food restaurant choice and food expenditure that explicitly accounts for both spatial and temporal determinants of demand. Estimates are obtained using a unique...

  8. Fast mixed spectrum reactor concept

    International Nuclear Information System (INIS)

    Kouts, H.J.C.; Fischer, G.J.; Cerbone, R.J.

    1979-04-01

    The Fast Mixed Spectrum Reactor is a highly promising concept for a fast reactor with improved features of proliferation resistance, and excellent utilization of uranium resources. In technology, it can be considered to be a branch of fast breeder development, though its operation and implications are different from those of FBR'S in important respects. Successful development programs are required in several areas to bring FMSR to reality, but the payoff from a successful program can be high

  9. Ultra-fast boriding of metal surfaces for improved properties

    Science.gov (United States)

    Timur, Servet; Kartal, Guldem; Eryilmaz, Osman L.; Erdemir, Ali

    2015-02-10

    A method of ultra-fast boriding of a metal surface. The method includes the step of providing a metal component, providing a molten electrolyte having boron components therein, providing an electrochemical boriding system including an induction furnace, operating the induction furnace to establish a high temperature for the molten electrolyte, and boriding the metal surface to achieve a boride layer on the metal surface.

  10. Linear Dynamics Model for Steam Cooled Fast Power Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Vollmer, H

    1968-04-15

    A linear analytical dynamic model is developed for steam cooled fast power reactors. All main components of such a plant are investigated on a general though relatively simple basis. The model is distributed in those parts concerning the core but lumped as to the external plant components. Coolant is considered as compressible and treated by the actual steam law. Combined use of analogue and digital computer seems most attractive.

  11. MHD induced fast-ion losses on ASDEX Upgrade

    International Nuclear Information System (INIS)

    GarcIa-Munoz, M.; Fahrbach, H.-U.; Bobkov, V.; Bruedgam, M.; Guenter, S.; Igochine, V.; Lauber, Ph.; Mantsinen, M.J.; Maraschek, M.; Poli, E.; Sassenberg, K.; Tardini, G.; Zohm, H.; Pinches, S.D.; Gobbin, M.; Marrelli, L.; Martin, P.; Piovesan, P.

    2009-01-01

    A detailed knowledge of the interplay between MHD instabilities and energetic particles has been gained from direct measurements of fast-ion losses (FILs). Time-resolved energy and pitch angle measurements of FIL caused by neoclassical tearing modes (NTMs) and toroidicity-induced Alfven eigenmodes (TAEs) have been obtained using a scintillator based FIL detector. The study of FIL due to TAEs has revealed the existence of a new core-localized MHD fluctuation, the Sierpes mode. The Sierpes mode is a non-pure Alfvenic fluctuation which appears in the acoustic branch, dominating the transport of fast-ions in ICRF heated discharges. The internal structure of both TAEs and Sierpes mode has been reconstructed by means of highly resolved multichord soft x-ray measurements. A spatial overlapping of their eigenfunctions leads to a FIL coupling, showing the strong influence that a core-localized fast-ion driven MHD instability may have on the fast-ion transport. We have identified the FIL mechanisms due to NTMs as well as due to TAEs. Drift islands formed by fast-ions in particle phase space are responsible for the loss of NBI fast-ions due to NTMs. In ICRF heated plasmas, a resonance condition fulfilled by the characteristic trapped fast-ion orbit frequencies leads to a phase matching between fast-ion orbit and NTM or TAE magnetic fluctuation. The banana tips of a resonant trapped fast-ion bounce radially due to an E x B drift in the TAE case. The NTM radial bounce of the fast-ion banana tips is caused by the radial component of the perturbed magnetic field lines.

  12. FastChem: An ultra-fast equilibrium chemistry

    Science.gov (United States)

    Kitzmann, Daniel; Stock, Joachim

    2018-04-01

    FastChem is an equilibrium chemistry code that calculates the chemical composition of the gas phase for given temperatures and pressures. Written in C++, it is based on a semi-analytic approach, and is optimized for extremely fast and accurate calculations.

  13. Components of Sexual Identity

    Science.gov (United States)

    Shively, Michael G.; DeCecco, John P.

    1977-01-01

    This paper examines the four components of sexual identity: biological sex, gender identity, social sex-role, and sexual orientation. Theories about the development of each component and how they combine and conflict to form the individual's sexual identity are discussed. (Author)

  14. Towards Cognitive Component Analysis

    DEFF Research Database (Denmark)

    Hansen, Lars Kai; Ahrendt, Peter; Larsen, Jan

    2005-01-01

    Cognitive component analysis (COCA) is here defined as the process of unsupervised grouping of data such that the ensuing group structure is well-aligned with that resulting from human cognitive activity. We have earlier demonstrated that independent components analysis is relevant for representing...

  15. Untangling Galaxy Components - The Angular Momentum Parameter

    Science.gov (United States)

    Tabor, Martha; Merrifield, Michael; Aragon-Salamanca, Alfonso

    2017-06-01

    We have developed a new technique to decompose Integral Field spectral data cubes into separate bulge and disk components, allowing us to study the kinematic and stellar population properties of the individual components and how they vary with position. We present here the application of this method to a sample of fast rotator early type galaxies from the MaNGA integral field survey, and demonstrate how it can be used to explore key properties of the individual components. By extracting ages, metallicities and the angular momentum parameter lambda of the bulges and disks, we show how this method can give us new insights into the underlying structure of the galaxies and discuss what this can tell us about their evolution history.

  16. Superalloy applications in the fast breeder reactor

    International Nuclear Information System (INIS)

    Powell, R.W.

    1976-01-01

    The economics of the LMFBR are dependent on the breeding of new fuel in the reactor core and this can be improved by the use of advanced alloys as core structural components. The environment of the core makes superalloys a natural choice for these components, but phenomena related directly to neutron irradiation necessitate extensive testing. Consequently, commercially-available superalloys, together with a number of developmental alloys are being tested in existing LMFBR's and by simulation techniques to determine the best alloy for use in the LMFBR core. It presently appears that such materials will indeed be capable of the performance required, and will greatly facilitate the commercial realization of the fast breeder reactor

  17. Fast disk array for image storage

    Science.gov (United States)

    Feng, Dan; Zhu, Zhichun; Jin, Hai; Zhang, Jiangling

    1997-01-01

    A fast disk array is designed for the large continuous image storage. It includes a high speed data architecture and the technology of data striping and organization on the disk array. The high speed data path which is constructed by two dual port RAM and some control circuit is configured to transfer data between a host system and a plurality of disk drives. The bandwidth can be more than 100 MB/s if the data path based on PCI (peripheral component interconnect). The organization of data stored on the disk array is similar to RAID 4. Data are striped on a plurality of disk, and each striping unit is equal to a track. I/O instructions are performed in parallel on the disk drives. An independent disk is used to store the parity information in the fast disk array architecture. By placing the parity generation circuit directly on the SCSI (or SCSI 2) bus, the parity information can be generated on the fly. It will affect little on the data writing in parallel on the other disks. The fast disk array architecture designed in the paper can meet the demands of the image storage.

  18. Utilization of large electromagnetic pumps in the fast breeder reactors

    International Nuclear Information System (INIS)

    Deverge, C.; Lefrere, J.P.; Peturaud, P.; Sauvage, M.

    1984-04-01

    After an overview concerning the induction annular electromagnetic pumps and the dimensioning methods usually utilized, development of these components for a fast breeder integrated reactor is considered: - utilization of cooled EMP in the intermediate circuit, - utilization of immersed pumps, coupled with the intermediate exchanger, for the primary pumping; dimensioning, energetic aspects, and effects on the power plant geometrical configurations [fr

  19. A robust and fast generic voltage sag detection technique

    DEFF Research Database (Denmark)

    L. Dantas, Joacillo; Lima, Francisco Kleber A.; Branco, Carlos Gustavo C.

    2015-01-01

    In this paper, a fast and robust voltage sag detection algorithm, named VPS2D, is introduced. Using the DSOGI, the algorithm creates a virtual positive sequence voltage and monitories the fundamental voltage component of each phase. After calculating the aggregate value in the o:;3-reference fram...

  20. Structural and Compositional Transformations of Biomass Chars during Fast Pyrolysis

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Steibel, Markus; Spliethoff, Hartmut

    In this work the physical and chemical transformations of biomass chars during fast pyrolysis, considered as a 2nd stage of combustion, has been investigated. Seven biomasses containing different amount of ash and organic components were reacted at up to 1673 K with high heating rates in a wire...